Note: Descriptions are shown in the official language in which they were submitted.
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A-22055/A
_1_
Surface-active photoinitiators
The invention relates to a process for the preparation of scratch-resistant
durable coatings in
which siloxane-containing photoinitiators are used as surface-active
initiators, and to new
surface-active photoinitiators.
In order to improve the miscibility of photoinitiators with silicone-
containing substrates (com-
patibility) that are to be photochemically crosslinked, WO 97/49768, US
5776658,
US 4391963 and EP 88842, for example, propose photoinitiators, e.g. of the
hydroxy-ketone,
aminoketone, benzoin ether, benzophenone or thioxanthone type, that have been
modified
with silyl radicals, especially with polymeric silyl radicals. Patent
Specifications US 4536265,
US 4534838 and EP 162572 also describe a wide variety of photoinitiator
structures pro-
vided with organopolysiloxane radicals. Those compounds are derived, for
example, from
dialkoxyacetophenones and have enhanced solubility in silicone substrates. US
4507187
discloses silyl-group-containing diketo photoinitiators as photoinitiators
that are readily solu-
ble in silicone polymers, and also the polymers obtained with those
initiators. US 4477326
describes self-polymerising siloxane polymers that contain photoinitiator
units as groups that
trigger the polymerisation reaction. Polymeric photoinitiators containing
siloxane radicals are
described in US 4587276.
In J.M.S. Pure Appl. Chem. A31(3) (1994), 305-318, A. Kolar, H.F. Gruber and
G. Greber
describe reactive silyl-derived a-hydroxyketone photoinitiators. The
literature references
mentioned are concerned especially with solving the problem of improving the
miscibility of
the photoinitiators with the substrate to be polymerised, that is to say
distributing the initiator
in the substrate as homogeneously as possible. WO 98/00456 proposes certain
coating
compositions, and a curing process by means of which the properties of the
coating surface
can be improved.
New energy-saving curing mechanisms and applications that result in as few
emissions as
possible are sought by the coatings industry in order to produce durable,
scratch-resistant
coatings. There is especially a need to improve the surface of coatings,
especially in respect
of hardness, durability and gloss properties.
It has now been found that the desired properties can be obtained using
certain photo-
initiators in the coatings that are to be cured. For that purpose, the
photoinitiator is not dis-
tributed as homogeneously as possible in the formulation to be cured but is
concentrated in
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targeted manner at the surface of the coating to be cured; the initiator is
thus oriented in tar-
geted manner towards the surface of the formulation. For that purpose it is
necessary to use
photoinitiators that have been designed in a particular manner.
The invention relates to a process for the preparation of coatings having
scratch-resistant du-
rable surfaces, in which
(I) a photocurable formulation comprising
(A) an ethylenically unsaturated polymerisable compound; and
(B) a photoinitiator;
is prepared;
(II) that formulation is applied to a support; and
(III) the formulation is cured either
solely by irradiation with electromagnetic radiation of a wavelength of from
200 to
600 nm, or
by irradiation with electromagnetic radiation of a wavelength of from 200 to
600 nm and
by prior, simultaneous and/or subsequent action of heat;
in which process
the formulation comprises as photoinitiator (B) at least one surface-active
photoinitiator that
is concentrated at the surface of the formulation.
A surface-active photoinitiator is used as photoinitiator (B). Photoinitiator
(B) is a photo-
initator compound that is incompatible with the formulation to be cured, that
is to say has
poor miscibility therewith, and is therefore able to concentrate at the
surface of the formula-
tion.
A suitable surface-active photoinitiator (B) in the process described above is
a compound
comprising
a customary photocleavable photoinitiator molecule moiety (b1 ) and
a molecule moiety (b2) that is incompatible with the formulation to be cured.
Customary photocleavable molecule moieties are known to the person skilled in
the art, and
are, for example, a-cleaving radicals. Of special interest are compounds in
which the
photocleavable photoinitiator molecule moiety (b1 ) contains a group
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The molecule moiety (b2) having poor compatibility with the formulation to be
cured is a si-
loxane radical.
Suitable photoinitiators (B) are especially compounds of formula I,
Rz R3
ii-O ii O Az (I)
m R° P
x
wherein the units of formulae la, Ib and/or Ic
I Rz Rs
sl-o (la), ~ I-o (Ib), sl-o (Ic)
H Ra
IN
l
are arranged randomly or in blocks, and wherein
n is a number from 1 to 1000, or, when the siloxane starting material is a
mixture of oli-
gomeric siloxanes, n may also be less than 1, but greater than 0;
m is a number from 0 to 100;
p is a number from 0 to 10 000;
x is the number 1 or 2;
Rs
A, is C,-C,aalkyl or a radical of formula -~- i i-Ra ;
R~
la
A2 is C,-C,8alkyl or a radical of formula - i ~-Rs ;
Rio
or A, and Az together are a single bond;
R,, R2, R3, Rs, R6, R~, Ra, R9 and R,o are each independently of the others C,-
C,ealkyl,
phenyl, C2-Cahydroxyalkyl, C2-Csaminoalkyl or Cs-Cacycloalkyl;
R4 is C,-C,aalkyl; C,-C,aalkyl substituted by hydroxy, C,-C,2alkoxy, halogen,
C3-Ca-
cycloalkyl andlor by N(R")(R,2); or R4 is phenyl; phenyl substituted by C,-
C,2alkyl, C,-C,2-
alkoxy, halogen, hydroxy andlor by N(R")(R,2); or R4 is Cs-Cacycloalkyl;
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R" and R,2 are each independently of the other hydrogen, C,-C,2alkyl or C,-
C,2hydroxy-
alkyl, or R" and R,2 together are C2-Caalkylene, which may be interrupted by
an oxygen
atom;
O R~3
IN when x is 1, is a radical of formula - ~c-c-x ; or
~Y
Ria
O R~3
IN when x is 2, is a radical of formula -Y~c-c-x;
R~4
R,3 and R,4 are each independently of the other C,-C,2alkyl, C2-CBalkenyl, Cs-
Cscycloalkyl,
phenyl-C,-C3alkyl; or R,3 and R,4 together are C2-Csalkylene, C3-C9oxaalkylene
or C3-C9-
azaalkylene;
Y is -(CH2)a , -(CH2)a-O-, -O-(CH2)a O-, -(CH2)b-O-(CH2)a-, -(CH2)b-O-(CH2)a-O-
,
-(CH2)a N(R,2)- -(CHZ)b-O-(CH2)a-N(Rm)-, -(C2-C,oalkenylene)-O-,
-(C2-C~oalkenylene)-N(R,2)-, -(C2-C,oalkenylene)-O-(CH2)a O- or
-(C2-C,oalkenylene)-O-(CH2)a N(R~2)- ;
a and b are each independently of the other a number from 0 to 10;
X is OR,S or N(R,s)(R,~);
R,5 is hydrogen, C,-Caalkyl, C2-CBalkenyl or C,-C4alkanoyl;
R,s and R,~ are each independently of the other hydrogen, C,-C,2alkyl or C2-
Csalkenyl; or R,s
and R» together are C4-Csalkylene and, together with the nitrogen atom to
which they are
bonded, form a 5- or 6-membered ring, which may be interrupted by O or by
N(R,2); and
X, is a radical -O-, -O-(CH2)a or -N(R,2)-(CH2)a
A number of compounds of formula I are novel and form part of the subject
matter of the pre-
sent Application.
C,-C,sAlkyl is linear or branched and is, for example, C,-C,2-, C,-Cs-, C,-Cs-
or C,-C4-alkyl.
Examples thereof are methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl,
isobutyl, tert-butyl,
pentyl, hexyl, heptyl, 2,4,4-trimethylpentyl, 2-ethylhexyl, octyl, nonyl,
decyl, undecyl, dodecyl,
hexadecyl and octadecyl. For example, R,, R2, R3, R4, R5, Rs, R,, Ra, R9 and
R,o are
C,-CBalkyl, especially C,-Csalkyl, preferably C~-C4alkyl, such as methyl or
butyl, especially
methyl.
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C,-C,2AIkyl, C,-C,oalkyl and C,-Csalkyl are also linear or branched and have,
for example,
the meanings given above up to the corresponding number of carbon atoms.
Substituted alkyl is, for example, mono- to penta-substituted, mono- to tri-
substituted or
mono- or di-substituted.
Alkyl substituted by halogen is substituted, for example, by fluorine,
chlorine, bromine or
iodine.
Alkyl substituted by OH is mono- or poly-substituted, especially mono-
substituted, by OH.
Examples thereof are 2-hydroxyeth-1-yl, 3-hydroxyprop-1-yl and hydroxymethyl.
C2-CsHydroxyalkyl is hydroxy-substituted C2-Csalkyl, wherein the alkyl has the
meanings
given above according to the number of carbon atoms.
C2-C6Aminoalkyl is C2-Csalkyl substituted by an amino radical, especially by -
NH2, wherein
the alkyl has the meanings given above according to the number of carbon
atoms.
C2-CaAlkylene is linear or branched, such as ethylene, propylene,
isopropylene, n-butylene,
sec-butylene, isobutylene, tert-butylene, pentylene, hexylene, heptylene or
octylene. When
R,3 and R,4 together are C2-CBalkylene, they are especially pentylene, that is
to say, together
with the carbon atom to which they are bonded, they form a cyclohexyl ring,
the following structure being intended -~~ X~~ ,
_ o
especially -
C3-C90xaalkylene and C3-C9azaalkylene are alkylene, as described above,
interrupted by O-
or by N(R,2).
C5-C$Cycloalkyl is linear or branched alkyl containing at least one ring, for
example cyclo-
pentyl, methylcyclopentyl, cyclohexyl, methyl- or dimethyl-cyclohexyl or
cyclooctyl, especially
cyclopentyl and cyclohexyl.
C,-C,2AIkoxy denotes linear or branched radicals and is, for example, C,-C8-,
C,-C6- or
C,-C4-alkoxy. Examples thereof are methoxy, ethoxy, propoxy, isopropoxy, n-
butyloxy, sec-
butyloxy, isobutyloxy, tert-butyloxy, pentyloxy, hexyloxy, heptyloxy, 2,4,4-
trimethylpentyloxy,
2-ethylhexyloxy, octyloxy, nonyloxy, decyloxy and dodecyloxy, especially
methoxy, ethoxy,
propoxy, isopropoxy, n-butyloxy, sec-butyloxy, isobutyloxy, tert-butyloxy,
preferably methoxy.
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C,-CBAIkoxy is also linear or branched and has, for example, the meanings
given above up to
the corresponding number of carbon atoms.
C2-CSAlkenyl is mono- or poly-unsaturated and linear or branched, and is, for
example, C2-C6-
or C2-C4-alkenyl. Examples thereof are allyl, methallyl, 1,1-dimethylallyl, 1-
butenyl, 2-butenyl,
1,3-pentadienyl, 1-hexenyl and 1-octenyl, especially allyl. R,3 and R,4 as C2-
C$alkenyl are, for
example, C2-Csalkenyl, especially C2-C4alkenyl.
C2-C,oAlkenylene is a divalent radical that is mono- or poly-unsaturated and
linear or
branched, and is, for example, C2-C6- or C2-C4-alkenylene. Examples thereof
are allylene,
methallylene, 1,1-dimethylallylene, vinylene, 1-butenylene, 2-butenylene, 1,3-
pentadienyl-
ene, 1-hexenylene and 1-octenylene, especially allylene.
C,-C4AIkanoyl is linear or branched and is, for example, formyl, acetyl,
propionyl, butanoyl or
isobutanoyl.
Halogen is fluorine, chlorine, bromine or iodine, for example fluorine,
chlorine or bromine,
especially chlorine or fluorine.
Phenyl-C,-C3alkyl is, for example, benzyl, phenylethyl, a-methylbenzyl or a,a-
dimethylbenzyl,
especially benzyl.
When R~6 and R,~ together with the nitrogen atom to which they are bonded form
a 6-
membered aliphatic ring, which may be interrupted by a further nitrogen or
oxygen atom, it is,
for example, a morpholinyl, piperidinyl or piperazinyl ring.
When R" and R,2 together are C2-C8alkylene that may be interrupted by an
oxygen atom,
they form together with the nitrogen atom to which they are bonded, for
example, a piperidi-
nyl or morpholinyl ring.
The units of formulae la, Ib and/or Ic are arranged randomly or in blocks,
that is to say in the
formula drawing given for formula I the units may be arranged in any order.
For example,
blocks of units of formulae la, Ib and Ic may follow one another, but the
individual units may
also be linked in random distribution, depending upon the siloxane used during
preparation.
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_7_
The expression "and/or" indicates that not just one of the defined
alternatives (e.g. substi-
tuents) may be present, but that it is also possible for a plurality of
different defined alternati-
ves (e.g. substituents) to be present together, that is to say mixtures of
different alternatives
(e.g. substituents) may be present.
The expression "at least one" is intended to mean one or more than one, for
example one or
two or three, preferably one or two.
R,3 and R~4 are, for example, C,-C4alkyl, especially methyl. Preferably R13
and R,4 are
methyl or together are C3-Cealkylene; in particular, together with the carbon
atom to which
they are bonded they form a cyclohexylring, or R,3 is C,-C4alkyl, especially
ethyl, and R~4 is
allyl or benzyl.
"a" is preferably a number from 0 to 10, e.g. from 0 to 3, especially 3; "n"
is preferably from 1
to 100; "p" is, for example, from 1 to 1000, from 1 to 100, from 1 to 50 or
from 1 to 25; and
"m" is from 0 to 100, e.g. from 0 to 50 or from 0 to 25, especially 0.
When the siloxane starting material is a mixture of oligomeric siloxanes, "n"
may also be less
than 1, but greater than 0. In that case, "n" is, for example, a number from
0.1 to 1000, from
0.5 to 1000, from 0.8 to 1000, etc..
X is preferably OR,S and R,5 is preferably hydrogen.
Y is preferably -(CHZ)a O- , -(CH2)a-O-(CH2)a- or -(CH2)a O-(CH2)a O-, where a
is
especially 3.
In the IN group, Y is especially positioned on the phenyl ring in the para-
position relative to
the carbonyl group.
R,6 and R" are especially C,-C4alkyl, preferably methyl, or together with the
nitrogen atom to
which they are bonded form a morpholinyl radical.
R,, R2 and R3 are preferably C,-C4alkyl, especially methyl.
R4 is especially C,-C4alkyl, for example methyl.
Preference is given to a process as described above in which the su rface-
active photo-
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initiator (B) is a compound of formula I, wherein
n is a number from 1 to 10, or, when the siloxane starting material is a
mixture of oli-
gomeric siloxanes, n may also be less than 1, but greater than 0;
m is a number from 0 to 25;
p is a number from 0 to 25;
Rs
A, is C,-C4alkyl or a radical of formula -o-s.-R6 ;
R~
Re
A2 is C,-C4alkyl or a radical of formula -si-R9 ;
Rio
or A, and A2 together are a single bond;
R,, R2, R3, R5, Rs, R,, R8, R9 and R,o are each independently of the others C,-
C4alkyl;
R4 is C,-C4alkyl;
R,3 and R,4 are each independently of the other C,-C4alkyl; or R,3 and R,4
together are
C2-Cgalkylene;
Y is -(CH2)a O-, -(CH2)b-O-(CH2)a- or -(CH2)b-O-(CH2)a O- ;
a and b are each independently of the other the number 2 or 3;
R,5 is hydrogen;
R,6 and R" together are C4-CSalkylene and together with the nitrogen atom to
which
they are bonded form a 6-membered ring interrupted by O; and
X, is a radical -O-(CH2)a .
CH3 _ O CH3
Of special interest are the compounds ~CH3)3SrO~2Sl-(CHZ)3 O ~ / CI- i -off ,
CHI
CH3 _ O CH3 CH3
~CH3)~Si-OtSi-(CHZ)3 O \ ~ IC- i O (CHZ)3-g1~0-SI(CH3)3~ 2 ,
J 2 CHs
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_g_
CH3
H3C-Si-CH3 _ O CH
3
O CH3 ~ / (CHx)s O \ / C-C-OH
CH3 CH3 CH3 ~ I ~ , H3C-Si CH
H3C-Si-O-Si-O-Si-(CH2)3 O \ ~ C-C-OH O
CH3 CH3 CH3 CH3 H3C-Si _ O CH3
O ~ (CH2)3 O \ / C-C-OH
H3C-Si-CH3 CH3
CH3
CH _ O CH3
3
H3C-Si 3 (CHZ)3 O \ ~ C-C-OH H3C (CH -O~OC-CHOH
~r'H3 ~ /~ 2)3 \ / I
I ~ H3C-Si CH3
H C-Si-CH p
I
_ O CH3 H3C-SI _ ~ CH3
H3C-Si-(CH2)3 O \ ~ C-C-OH H C ~(CH2)3 O \ / C-C-OH
CH3 CH3 CH3
3p
HO-CH CI ~ \ O
CH3 ~CHz)3
O CHs
H3C Si-O~ CHs ~ I I
CH p Si-(CH2r0 \ / C-C-OH
HO-,C 3C / ~ O~CHz)3 Si~ ,O CH3
H3C O CH ~ ~ i-CH3 _ O CH3
(CHZ)3 O \ ~ C-C-OH
CH3
CH30 _ ~~ i Ha
HO-~-IC ~ ~ O-(\ 2)' ~(CH2)3 O \ / C-C-OH
CH \ .O- i W CH3
H3CiSi CH3 ; /CH3 _ O H3
iH3il _ Si,~CH3 ~I~(CHZ)3 p ~ ~ C-~-pH
HO- i -C \ / O-(CHZ)3 10 ~Si~-CH _ O CH CH3
CH3 (CHZ)3~0 C-C 30H
i
CH3
CH3 CH3
H3C-Si-CH3 H3C-Si-CH3
I
O _ O CH3 O
2 3 Si-CH
H3C-Si-H-~-(CHZ)2 O 2 \ / C C O (CH )
p z CH3 O
H C-Si-CH
H3C-SrCH3 3 I 3
CH3 CH3
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CH3
H3C-Si-CH3
_ O CH CH3 CH3 - O CH3
H3C-Si-(CH2)3 O ~ ~ C-C-N ~ H3C-Si-O-Si-(CH2)3 O ~ ~ C-C-N O
p CH V CH3 CH3 CH3 U
3
H3C-Si-CH3
CH3
CHa CHa CHa
H C-Si-CH H3C-Si-CHa H3C-Si-CHa
3 ~ 3
_ O CH O _ O CHa O
H3C-Oi (CHZ)3 O (CHZ)a ~ / C CHOH ~ H3C p (CH2)a O (CHZ)a ~ / C CHO (CHZ)a Si-
CHa
H C-Si'CHa H3C-$i'CHa HaC-Si-CHa
a CHa CHa CHa
~H3 CHa
H3C-Si-CHa H3C-Si-CH3
'O' CHa ~ H C-OSi-NCH ) O-(CH ) O ~ / OC
H3C-Si-(CHZ)3 O-(CHZ)a ~ ~ c-c-N o and 3 I z a a z HO
O CH ~/ O
H C-$i'CHa H3C-Si-CHa
a CH CHa
3
The compounds of formula I are prepared according to customary methods known
to the
person skilled in the art.
Thus, compounds of formula I may be obtained, for example, by reacting a
photoinitiator with
at least one alkenyl radical (IV) or (IVa) and a siloxane (V) in the presence
of a suitable
catalyst:
R~3 ~ 13
x-c-c ~ x-c-c
I Il~r-c=cH2 I II Y-C-C=CH2 IVa
R~4 O H (IV) Or R~4 O Hz H ( )
IN IN
R~ Rz Ra ( )
A~ i i-O i i-O Si-O Az
H L H LRa
m P
catalyst
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_ 11 _
R2 R3
A, ~ i-O i i-O Si-O A2
n H m Ra P
IN
wherein IN, R,, R2, R3, R4, R,3, R,4, X, Y, A,, A2, n, m and p are as defined
above.
In order to prepare compounds of formula I wherein x = 2, suitably modified
photoinitiators
are used, that is to say those having, for example, 2 alkylene units.
The alkylene unit may, for example, be present at a different position on the
photoinitiator
molecule and the linkage to the siloxane is then effected in that position:
O OH
ii I
Catalyst ~ C-~-(CH2)a ~~-R~
CFi HZ H Chl2 + (V) ~ , CH3 n
3
H-SrR2
m
R4 Si-R3
~P
Such reactions are described, for example, in US 4391963, EP 162572 or N.S.
Allen et al.,
J.Photochem. Photobiol. A: Chem. 62 (1991), 125-139.
Reaction conditions for such reactions will be known to the person skilled in
the art. The
molar ratios of the alkenyl-modified compound (IV) and the siloxane compound
(V) are de-
pendent upon the desired product and are generally not critical. For example,
the amount of
(IV) to be used will be selected according to the content of free Si-H groups
in (V) and the
desired degree of substitution of those groups in the particular case. If all
the groups are to
react, it is advantageous, for example, to use (IV) in excess. It is also
possible, however, to
use an excess of component (V).
The reaction temperatures are advantageously kept within a range of from 20 to
150°C, pref-
erably from 60 to 110°C. It is also advantageous to carry out the
reaction, for example, in a
suitable aprotic organic solvent, such as tetrahydrofuran (THF), dioxane,
hexane, heptane,
cyclohexane, toluene, xylene, benzene or chlorobenzene. The reaction may,
however, also
be carried out, for example, without solvent.
The reaction mixture will usually be stirred while the reaction is being
carried out.
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It is also advantageous to carry out the reaction under inert conditions, for
example under an
argon or nitrogen atmosphere.
Catalysts suitable for carrying out the reaction are, for example, noble metal
catalysts, such
as platinum or rhodium catalysts. Examples thereof are HZPtCIs and PtCl2(C6H5-
CH=CHZ)2.
Such catalysts may, for example, also be applied to suitable support
materials, for example
aluminium oxide, such as PtIAl203 (for example, obtainable from Heraeus).
Examples of
suitable catalysts are platinum, palladium, rhodium, nickel, cobalt, or other
metals in pow-
dered form or in complexes; platinum sponge, platinum black, chloroplatinic
acid, the reac-
tion product of chloroplatinic acid and alcohol, a complex of chloroplatinic
acid and vinyl si-
loxane. Such catalysts are commercially available, for example platinum/-
carbonyl/cyclovin-
ylmethylsiloxane complex, platinum/divinyltetramethyldisiloxane complex, plati-
numloctanealdehyde/octanol complex, or may be obtained according to methods
customary
in the art and known to the person skilled in the art.
The concentration of the catalyst is advantageously, for example, from 1 to
1000 ppm, for
example from 150 to 400 ppm.
A further possible method of preparing the surface-active photoinitiators is
to react a photo-
initiator that contains a suitable silyl group with an alkenyl-modified
siloxane:
A~
i Ai Rz
I catalyst
H-Si-IN ~- H2C=C-R'-Si-R, R~ Si-R'-C-C-Si-IN
R3 H ~ p Hz Hz Rs
R,, RZ, R3, IN and A, are as defined above; R' is an alkylene radical;
"...." indicates that the radical of the siloxane molecule moiety defined in
formula I is attached
at that position (according to formula I in this reaction in the starting
material m must be 0).
The reaction conditions for this method correspond to those described above.
Such reac-
tions are described in the literature, for example, in US 4 391 963 and in JMS
Pure Applied
Chem. A31 (3) (1994), 305.
The surface-active photoinitiators may, for example, also be obtained by
reacting an OH-
group-containing initiator with a siloxane:
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A~
A~
HO-IN + H-Si-R~ ~' iN-O Si-R~
~n
H Si Rz
~m
R4 Si-R3
~P
Az
R~, R2, R3, IN, A~, n, m, p, R4 and A2 are as defined above; "...." indicates
that the radical of
the siloxane molecule moiety defined in formula I is attached at that
position.
Suitable catalysts for this reaction are, for example, tin octoate, dibutyltin
dilaurate, zinc oc-
tanoate, tin octanoate and zinc octanoate. Examples of such reactions
(although the exam-
ples contain a sensitiser unit instead of a photoinitiator unit) can be found
in US 4921589.
In JMS Pure Appl. Chem. A 34(11 ) (1997), 2335-2353, L. Lecamp et al. describe
a method
for preparing siloxane-containing initiators in which an initiator containing
an Si(OR)~_3 group
and a siloxane having an Si-(OH),_2 group are reacted. The catalyst used is,
for example, di-
butyltin dilaurate:
A R
z
A R Si ,
= ~' ' O-Si-IN
Si IN + HO- i i-R, O O
R"O
OR" I A~
Si-R~
. O
... I
IN, R,, R2 and A, are as defined above; R" is alkyl, especially methyl; "...."
indicates that the
radical of the siloxane molecule moiety defined in formula I is attached at
that position.
Surface-active photoinitiators according to the present invention can also be
obtained, for
example, by reacting a photoinitiator containing at least one carbonyl group
on the aromatic
ring with a siloxane containing a C-C double bond as terminal group (e.g.
allyl or vinyl).
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-14-
R\
~C ~
O A
O
C Rx __ _ _ ~ ~_ --~ HzC\
+ FizC H R~ i i R' C-R'-gi_R
/ Hz O ,
R, and A, are as defined above; Rx together with the adjacent carbonyl group
forms a ben-
zoin, an a-hydroxyketone or an a-aminoketone; R' is alkylene; "...." indicates
that the radical
of the siloxane molecule moiety defined in formula I is attached at that
position.
That reaction is published in US 5776658. Suitable catalysts for that reaction
are, for exam-
ple, ruthenium compounds, as described by Mural et al. in Nature 366 (1993)
529.
US 4 477 326 and JP 9-328522-A describe the polymerisation or copolymerisation
of polyal-
koxysiloxanes in the presence of a base or of an acid catalyst. The method
described is
suitable also for the preparation of surface-active initiators:
z
Rz -R~- H+ or -OH IN-Si-O-S
IN-Si-OR" + R O Si OR p
OR" Rz Si-
IN, R~ and Rz are as defined above; R" is alkyl.
In that reaction it is possible to obtain both polymeric and cyclic products.
A further possible method of preparing surface-active photoinitiators is
described, for exam-
ple, in US 4587276 and US 4477276, namely the polymerisation or
copolymerisation of si-
loxanes having hydrolysable groups (e.g. Si-CI) in the presence of water:
A, R, A,
R-Si-R H2O R2 Si-O-Si-R'
IN-Si-Ra + a I ' ~' ~N of
Rz
IN, R,, R2 and A~ are as defined above; Ra is, for example, CI or OCH3; "...."
indicates that
the radical of the siloxane molecule moiety defined in formula I is attached
at that position.
In J.M.S. Pure Appl. Chem. A 31 (3) (1994), 305-318, A. Kolar et al. describe
the preparation
of photoinitiators containing siloxane radicals starting from 1,4-
dichlorobenzene. A Grignard
CA 02314668 2000-07-27
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reaction creates a reactive centre, which is reacted with
dirnethyldichlorosilane or dimethyl-
monochlorosilane to form the corresponding silyl-modified chlorobenzene, into
which the ap-
propriate a-cleavable photoinitiator carbonyl radical is introduced by further
reactions.
In Makromol. Chem. 193 (1992) 1273-1282, L. Pouliquen et al. published a multi-
step reac-
tion of photoinitiators having acid groups and a siloxane having epoxy
radicals in the pres-
ence of acetic anhydride (the photoinitiator compounds in that reference are
of the phe-
noneltert-amine type)
H3C-C=O
O p'~ O O
II p ~ ii n O
IN- C - OH + ~R'- i i-R, + H3C.C_O.C.CH3 _~ O HC-R~- i i-R~
O IN-C-O-CH2
IN, A~ and R~ are as defined above; R' is alkylene; "...." indicates that the
radical of the silox-
ane molecule moiety defined in formula I is attached at that position.
Isocyanate-group-containing photoinitiators and siloxanes having hydroxyl or
amine groups
may also be reacted to form surface-active photoinitiators:
A H A
I' ,N. ~z,~ I'
Z- i-R~ IN C Si-R~
IN-N=C=O + ~ O
IN, A, and R, are as defined above; Z is NH2 or OH; Z, is NH or O; "...."
indicates that the
radical of the siloxane molecule moiety defined in formula I is attached at
that position.
Such reactions are described, for example, in WO 96/20919.
Photoinitiators substituted by cyclic siloxane radicals may be obtained, for
example, by
carrying out the reactions described above with a cyclic siloxane, for example
O-Si(R2)2 O
Si(R2)2 i I(R2)2 y
O-Si(R2)-O
H
In order to prepare photoinitiators provided with cyclic siloxane radicals, it
is also possible,
however, firstly to introduce linear siloxane radicals, for example by means
of the methods
CA 02314668 2000-07-27
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described above, and subsequently to cyclise them by the action of a base, for
example so-
dium hydroxide, or by the action of an acid.
The synthesis of surface-active photoinitiators containing cyclic siloxane
radicals can be car-
ried out, for example, as described above by reacting a cyclic siloxane with
the initiator moi-
ety in question:
H IN
I .R, I .R,
si s~
IN + o~ jo y --~ o~ jo y
si ~s~~
R~ ~H Ri IN
(IN and R~ are as defined above; y determines the size of the ring)
or by a cyclisation reaction of an OR-group-containing siloxane-modified
initiator moiety in
the presence of an acid or alkali:
IN
R _ I.R
H+ or OH ~ Sip
IN-Si-(OR")b O~ /O y
~Si
R \IN
(R, and IN are as defined above; R" is alkyl; a= 0 or 1; b=1 or 2, where the
sum of a+b=3;
depending upon the value of a and b, R is either R, or OR")
Cyclic compounds can also be formed by reacting an OR-group-containing
siloxane-modified
initiator moiety with an OR-group-containing siloxane:
IN
~,R~
_ Si
IN-Si- OR" + R-Si-(OR") H+ or OH
( )2 2 2 y
O
j~ i
RZ R
' y1
(IN, R, and R2 are as defined above; R" is alkyl; the sum of y and y1
determines the number
of ring members)
The distribution of the Si(IN)(R,) and Si(R~)(R2) groups will be either random
or in blocks.
The preparation of the surface-active photoinitiators may also yield mixtures
of active com-
pounds. Such mixtures can be separated by customary methods, such as
distillation, crys-
CA 02314668 2000-07-27
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tallisation or chromatography, or they may be used as such as surface-active
photoinitiators
in compositions to be polymerised.
The invention relates also to photoinitiator mixtures comprising
CH3 ~ ~H3 Hs _ ~ CH3 CH3
~(CH3)3SI-o~2$I~CHz)3 0 ~ ~ CI-C-off ~ CCH3)3Si-O~2 1-~CHZ)3 O ~ ~ C-C-O-S1~0-
SI(CH3)3] 2 ,
CH3 CH3
i H3 - O CH3 i H3 i Hs ~~ CH3
[CH3)3Si-O~-Si-O ~ ~ C-C-O-Si-EO-Si(CH3)3] 2 and/or (CH3)3Sj-O SI-O ~ ~ C-C-OH
s
2 CHs 2 CHs
~Hs O CH3 CH3
or mixtures comprising CCH3)3SI-O~-SI-(CHZ)3 O ~ ~ C-C-O-(CH2)3 Si~O-Si(CH3)~
,
CH3 2
CH3 O CH3 CH3 i Hs _ ~ CH3
[CH3)3Si-0~2Si-O ~ ~ C-C-O-Si-~O-Si(CH3)3]2 ~ [(CH3)sSwO~"SI-O ~ ~ c-CH off
and/or
z
CH3 3
i H3 _ ~ ~ Hs
[(CH3)3SI-O~Si~CHz)3 O ~ ~ C-C-OH ;
CH3
CH CH CH O CH3
or mixtures comprising ~ 3 ~ 3 ~ 3 ~II I ,
H3C-Si-O-Si-O-Si-(CH2)3 O ~ ~ C-C-OH
CH3 CH3 CH3 CH
3
CH CH CH _ O CH3 CH3 CH3 CH3
H C-Si-O-Si-O-Si 3(CH ) O ~ ~ CI-C-O-$i-O-Si-O-I~ i-CH3 '
3 CH3 CH3 CH3 z s CH3 ICH3 CH3 CH3
O CH CH CH I I I H
HZC=H-H-O ~ ~ CI-CH3 O-~i-O-Si O-1~ i CH3 andlOr H3C SH30--SHO SHO ~ ~ C-C 3
OH
z CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH
3
H3 CH3 CH3 a
_ O CH
or mixtures comprising Ho-~-c ~ ~ o-(cH2)3 ~Si-o-si-(cH2)3 0 ~ ~ c-c-off
CH30 CH3 CH3 CH3
CA 02314668 2000-07-27
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CH3 CH3 CH3 CH3 CH3 - O CH3
H-Si-O-Si-O-C-C ~ ~ O-(CH2)3 Si-O-Si-(CH2)3 O~C-C-OH
CH3 CH3 CHI CH3 CH \ / CH
3 3
CH3 CH3 CH3 _ O CH3
HO-C-C ~ ~ O-Si-O-Si-(CH2)3 O ~ ~ C-C-OH and/or
CH3 O CH3 CH3 CH3
CH3 / ~ CH3 CH3 O CH3
Ho-c-c-O-o-si-o-si-o ~ ~ c-c-off ; or mixtures comprising compounds of
CH30 CH3 CH3 CH3
R'
H C-Si-O CH3 _ O CH
formula 43~~ Si R2 (llla) wherein R'=R2=R3=R4= -(CH2)3 0 ~ ~ c-c-off ,
R-Sip ~O CH3
O-Si-CH3
CH3 R3
_ O CH
compounds of formula Illa wherein R'=R2=R3= -(cHz)3 0 ~ ~ c-c-off and R4= H,
CH3
_ O CH3
and/or compounds of formula Illa wherein R'=R2=R3= -(CH2)3 O ~ ~ C-C-OH and
CH3
R'
I R2
~Si
R4= -(CH2)2CH3 ; or mixtures comprising compounds of formula 5 0' ~o'S~~o
(Illb)
R jSi,~ Si~O~s3w
R a~ R
_ O CH3
wherein R'=R2=R3=R4= R5= -(cHz)3 0 ~ ~ c-c-off , compounds of formula Illb
CH3
_ O CH
wherein R'=R2=R3=R4= -tcH2)3 0 ~ ~ c-c-off and R5= H and/or compounds of
CH3
_ O CH
formula Illb wherein R'=R2=R3= -(cHz)3 0 ~ ~ c-c-off and R4=R5 = H;
CH3
CA 02314668 2000-07-27
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CH3
H3C-Si-GH3
O CH3
O' C-C-OH
or mixtures comprising H3C-Si-H~(CHz)z-O 2 \ / CH
2 3
1
H3C-Si-CH3
CH3
CH3 ~ Hs
H3C~g~-CH3 H3C-SnCH3
_ O CH3 O O Hz
H2C=c-C-o-C-c-o ~ ~ C-c-O-Si-CH3 and/or H3C-Si-O-C-C - O CH3
H Hz H2 Hz CH3 O O Hz O ~ ~ C-C-OH
H C.Si CH3 H3C-SI CHs
3 CH3 CH3CH3
CH3 CH3
H3C-Si'CH3 H3C-Si-CH3
i
O O CH3 O
or mixtures comprising H3c-o-H-f -(cH2)2 0 2 ~ ~ c-c-o-(cH2)3 si-cH3
z CH3 O
1 H C-Si-CH
H3C-SI-CH3 3 1 3
CH3 CH3
CH3 CH3
H3C-Si-CH3 H3C-Si-CH3
_ O _ O CH
H3C O (CHz)3 O-(CHz)z O ~ ~ OC-CHOC3H~ and/or H3C-Si-iCHz)3-O-(CHz)2 O ~ ~ C-C-
OH
O CH3 O CH3
H3C-Si-CH3 H3C-Si-CH3
CH3 CH3
CH3 CH3
H3C-Si-CH3 H3C-Si-CH3
O _ O CH3~--~ O CH3 _ O CH3~
or mixtures comprising H3C-Si-(CHZ)3 O ~ ~ C-C-N O , H3C-Si-H-CHZ O ~ ~ C-C-N~
O CH ~ O CH3
H3C-SI-CH3 3 H3C-Si-CH3
CH3 CH3
CH3
H3C- igi-CH3
H C--OSi-O ~ ~ C-C~HN~
and/or
O CHs
H3C-Si-CH3
CH3
CA 02314668 2000-07-27
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CH3 CH3 _ O CH3 ~
or mixtures comprising H3C-Si-O-Si-(CHZ)3 0 ~ ~ c-c-ni o and
CH3 CH3 CH3 ~
CH3 CH3 _ ~ CH3 ~
H3c-si-o-si-o ~ ~ c-c-N o ; or mixtures comprising
CH3 CH3 CH3~/
CH3 i H3
H3C-Si-CH3 H C-Si''CH3
i ('
O ' H3 3 ~ ~H3 _ O H3
f
H3C-Si-(CHZ)3 O-(CH2)3 ~ ~ C C OH ' H3C-Si-H-H-O-(CH2)3 ~ / C ~ OH
p CH3 O 2 CH3
H C-$i'CHs H3C-~i-CH3
3 CH3 CH3
OH _ O CH3
andlOr H3C-Si-(CHZ)3 O-(CHZ)3 ~ ~ C-C-OH ; or mixtures comprising
OH CH3
CH3 CH3
H3C-Si-CH3 H3C-Si-CH3
p - O CH3 O
i
H3C-Si-(CH2)3 O-(CH2)3 ~ ~ C-C-O-(CH2)3 Si-CH3 and
p CH3 O
i
H3C-Si'CHs H3C-Si-CH3
CH3 CH3
j "3
H3C-Si-CH3
_ p CH3
H3C-Si-(CH2)3 O-(CH2)3 ~ ~ C-C-OH
O CHs
i
H_C-Si'CH3
The alkenyl-modified photoinitiators (IV) can be prepared according to methods
known to the
person skilled in the art, for example according to the method described in EP
281941. Suit-
able processes have also been published in WO 97/49768.
Some of the siloxane compounds (V) are commercially available, or they can be
obtained
according to methods known to the person skilled in the art. For example,
preparation meth-
ods and literature references for preparation can be found in the catalogue of
the
Geleste company, "ABCR Geleste 2000", pages 434-447.
CA 02314668 2000-07-27
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The photoinitiators are used according to the invention in the curing of free-
radically poly-
merisable systems, with the aim of obtaining a cured surface having excellent
properties. A
crucial factor is that the photoinitiator concentrates at the surface of the
formulation to be
cured. As explained above, this is achieved by providing suitable substituents
on the photo-
initiator. Improved surface properties can be obtained using such initiators
not only in purely
photocurable systems, but also in mixed thermocurable/photocurable
formulations. The pre-
sent invention accordingly relates also to the use of photoinitiators of
formula I in purely
photocurable formulations and also to the use of photoinitiators of formula I
in mixed photo-
chemically and thermally curable formulations. Thermal curing can be effected
before, dur-
ing or after the irradiation.
The invention accordingly relates also to a process as described above, in
which the photo-
curable formulation comprises as further component at least one thermally
crosslinkable
compound (C), and the curing of the formulation is carried out by irradiation
with light of a
wavelength of from 200 to 600 nm and by prior, simultaneous and/or subsequent
action of
heat.
According to the invention the compounds of formula I may be used as surface-
active
photoinitiators for the photopolymerisation of ethylenically unsaturated
compounds or mix-
tures comprising such compounds, and become oriented towards the surface of
the formula-
tion in question. According to the invention the initiators of formula (I) are
not used in com-
positions that contain siloxane-modified resin components since concentration
at the surface
cannot occur therein, but instead the initiators are compatible with the
formulation and are
therefore readily miscible or compatible therewith.
The photoinitiators can also be used in combination with other photoinitiators
(E) and/or fu r-
ther additives (D).
The invention accordingly relates also to photopolymerisable compositions,
comprising
(A) at least one ethylenically unsaturated free-radically photopolymerisable
compound; and
(B) at least one surface-active photoinitiator of formula I,
provided that the composition does not contain any siloxane-modified resins in
addition to the
photoinitiator.
The invention relates also to photopolymerisable compositions, comprising
CA 02314668 2000-07-27
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(A) at least one ethylenically unsaturated free-radically photopolymerisable
compound;
(B) at least one surface-active photoinitiator of formula I, and
(C) at least one thermally crosslinkable compound;
provided that the composition does not contain any siloxane-modified resins in
addition to the
photoinitiator.
According to the invention, the compositions may also comprise further
different photo-
initiators (E) andlor further additives (D).
It is also possible to add catalysts for the thermal crosslinking. Suitable
examples are listed
below.
The unsaturated compounds (A) may contain one or more olefinic double bonds.
They may
be low molecular weight (monomeric) or higher molecular weight (oligomeric).
Examples of
monomers having a double bond are alkyl and hydroxyalkyl acrylates and
methacrylates,
such as methyl, ethyl, butyl, 2-ethylhexyl and 2-hydroxyethyl acrylate,
isobornyl acrylate and
methyl and ethyl methacrylate. Further examples thereof are acrylonitrile,
acrylamide, meth-
acrylamide, N-substituted (meth)acrylamides, vinyl esters, such as vinyl
acetate, vinyl ethers,
such as isobutyl vinyl ether, styrene, alkyl- and halo-styrenes, N-
vinylpyrrolidone,
vinyl chloride and vinylidene chloride.
Examples of monomers having several double bonds are ethylene glycol
diacrylate, propyl-
ene glycol diacrylate, neopentyl glycol diacrylate, hexamethylene glycol
diacrylate and
bisphenol A diacrylate, 4,4'-bis(2-acryloyloxyethoxy)diphenylpropane,
trimethylolpropane tri-
acrylate, pentaerythritol triacrylate or tetraacrylate, vinyl acrylate,
divinyl benzene, divinyl
succinate, diallyl phthalate, triallyl phosphate, triallyl isocyanurate and
tris(2-acryloylethyl)
isocyanurate.
Examples of higher molecular weight (oligomeric) poly-unsaturated compounds
are acrylated
epoxy resins, acrylated or vinyl-ether- or epoxy-group-containing polyesters,
polyurethanes
and polyethers. Further examples of unsaturated oligomers are unsaturated
polyester res-
ins, which are usually prepared from malefic acid, phthalic acid and one or
more diols and
have molecular weights of approximately from 500 to 3000. Vinyl ether monomers
and oli-
gomers, and maleate-terminated oligomers having polyester, polyurethane,
polyether, poly-
vinyl ether and epoxy main chains can also be used. In particular,
combinations of vinyl-
ether-group-carrying oligomers and polymers, as described in WO 90/01512, are
very suit-
CA 02314668 2000-07-27
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able. Also suitable are copolymers of monomers functionalised with vinyl ether
and malefic
acid. Such unsaturated oligomers can also be referred to as prepolymers.
Functionalised acrylates are also suitable. Examples of suitable monomers that
are normally
used to form the backbone (the base polymer) of such functionalised acrylate
and meth-
acrylate polymers are, for example, acrylate, methacrylate, methyl
methacrylate, ethyl acry-
late, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl
acrylate, isobutyl
methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, etc.. In
addition, suitable
amounts of functional monomers are copolymerised during the polymerisation so
as to obtain
the functional polymers. Acid-functionalised acrylate or methacrylate polymers
are obtained
using acid-functional monomers, such as acrylic acid and methacrylic acid.
Hydroxy-
functional acrylate or methacrylate polymers are produced from hydroxy-
functional mono-
mers, such as 2-hydroxyethyl methacrylate,~ 2-hydroxypropyl methacrylate and
3,4-
dihydroxybutyl methacrylate. Epoxy-functionalised acrylate or methacrylate
polymers are
obtained using epoxy-functional monomers, such as glycidyl methacrylate, 2,3-
epoxybutyl
methacrylate, 3,4-epoxybutyl methacrylate, 2,3-epoxycyclohexyl methacrylate,
10,11-
epoxyundecyl methacrylate, etc.. It is also possible to prepare e.g.
isocyanate-functionalised
polymers from isocyanate-functionalised monomers, such as meta-isopropenyl-a,a-
di-
methylbenzyl isocyanate.
Especially suitable are, for example, esters of ethylenically unsaturated mono-
or poly-
functional carboxylic acids and polyols or polyepoxides, and polymers having
ethylenically
unsaturated groups in the chain or in side groups, such as unsaturated
polyesters, poly-
amides and polyurethanes and copolymers thereof, alkyd resins, polybutadiene
and buta-
diene copolymers, polyisoprene and isoprene copolymers, polymers and
copolymers having
(meth)acrylic groups in side chains, and mixtures of one or more such
polymers.
Examples of suitable mono- or poly-functional unsaturated carboxylic acids are
acrylic acid,
methacrylic acid, crotonic acid, itaconic acid, cinnamic acid, malefic acid
and fumaric acid and
unsaturated fatty acids, such as linolenic acid or oleic acid. Preference is
given to acrylic
acid and methacrylic acid.
Saturated di- or poly-carboxylic acids in admixture with unsaturated
carboxylic acids may,
however, also be used. Examples of suitable saturated di- or poly-carboxylic
acids include,
for example, tetrachlorophthalic acid, tetrabromophthalic acid, phthalic acid
anhydride, adipic
acid, tetrahydrophthalic acid, isophthalic acid, terephthalic acid,
trimellitic acid,
CA 02314668 2000-07-27
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heptanedicarboxylic acid, sebacic acid, dodecanedicarboxylic acid,
hexahydrophthalic acid,
etc..
Suitable polyols are aromatic and especially aliphatic and cycloaliphatic
polyols. Examples
of aromatic polyols are hydroquinone, 4,4'-dihydroxydiphenyl, 2,2-di(4-
hydroxyphenyl)-
propane, and novolaks and resoles. Examples of polyepoxides are those based on
the poly-
ols mentioned, especially the aromatic polyols and epichlorohydrin. Also
suitable as polyols
are polymers and copolymers containing hydroxyl groups in the polymer chain or
in side
groups, such as polyvinyl alcohol and copolymers thereof or polymethacrylic
acid
hydroxyalkyl esters or copolymers thereof. Further suitable polyols are
oligoesters having
hydroxyl terminal groups.
Examples of aliphatic and cycloaliphatic polyols are alkylenediols having
preferably from 2 to
12 carbon atoms, such as ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3-
or 1,4-
butanediol, pentanediol, hexanediol, octanediol, dodecanediol, diethylene
glycol, triethylene
glycol, polyethylene glycols having molecular weights of preferably from 200
to 1500, 1,3-
cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,4-
dihydroxymethylcyclohexane,
glycerol, tris(~i-hydroxy-ethyl)amine, trimethylolethane, trimethylolpropane,
pentaerythritol,
dipentaerythritol and sorbitol.
The polyols may be partially or fully esterified by one or by different
unsaturated carboxylic
acid(s), it being possible for the free hydroxyl groups in partial esters to
have been modified,
for example etherified, or esterified with other carboxylic acids.
Examples of esters are:
trimethylolpropane triacrylate, trimethylolethane triacrylate,
trimethylolpropane trimethacry-
late, trimethylolethane trimethacrylate, tetramethylene glycol dimethacrylate,
tri-
ethylene glycol dimethacrylate, tetraethylene glycol diacrylate,
pentaerythritol diacrylate,
pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol
diacrylate, dipenta-
erythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol
pentaacrylate, dipenta-
erythritol hexaacrylate, tripentaerythritol octaacrylate, pentaerythritol
dimethacrylate, penta-
erythritol trimethacrylate, dipentaerythritol dimethacrylate,
dipentaerythritol tetra-
methacrylate, tripentaerythritol octamethacrylate, pentaerythritol
diitaconate, dipenta-
erythritol trisitaconate, dipentaerythritol pentaitaconate, dipentaerythritol
hexaitaconate,
CA 02314668 2000-07-27
-25-
ethylene glycol diacrylate, 1,3-butanediol diacrylate, 1,3-butanediol
dimethacrylate, 1,4-
butanediol diitaconate, sorbitol triacrylate, sorbitol tetraacrylate,
pentaerythritol-modified tria-
crylate, sorbitol tetramethacrylate, sorbitol pentaacrylate, sorbitol
hexaacrylate, oligo-
ester acrylates and methacrylates, glycerol di- and tri-acrylate, 1,4-
cyclohexane diacrylate,
bisacrylates and bismethacrylates of polyethylene glycol having a molecular
weight of from
200 to 1500, and mixtures thereof.
Suitable components (A) are also the amides of identical or different
unsaturated carboxylic
acids and aromatic, cycloaliphatic and aliphatic polyamines having preferably
from 2 to 6,
especially from 2 to 4, amino groups. Examples of such polyamines are
ethylenediamine,
1,2- or 1,3-propylenediamine, 1,2-, 1,3- or 1,4-butylenediamine, 1,5-
pentylenediamine, 1,6-
hexylenediamine, octylenediamine, dodecylenediamine, 1,4-diaminocyclohexane,
isopho-
ronediamine, phenylenediamine, bisphenylenediamine, di-[i-aminoethyl ether,
diethylenetri-
amine, triethylenetetraamine and di([3-aminoethoxy)- or di([3-
aminopropoxy)ethane. Further
suitable polyamines are polymers and copolymers which may have additional
amino groups
in the side chain and oligoamides having amino terminal groups. Examples of
such unsatu-
rated amides are: methylene bisacrylamide, 1,6-hexamethylene bisacrylamide,
diethylene-
triamine trismethacrylamide, bis(methacrylamidopropoxy)ethane, [3-
methacrylamidoethyl
methacrylate and N-[([3-hydroxyethoxy)ethyl]-acrylamide.
Suitable unsaturated polyesters and polyamides are derived, for example, from
malefic acid
and diols or diamines. The malefic acid may have been partially replaced by
other dicarbox-
ylic acids. They can be used together with ethylenically unsaturated
comonomers, for exam-
ple styrene. The polyesters and polyamides can also be derived from
dicarboxylic acids and
ethylenically unsaturated diols or diamines, especially from those having
longer chains of, for
example, from 6 to 20 carbon atoms. Examples of polyurethanes are those
composed of
saturated diisocyanates and unsaturated diols, or unsaturated diisocyanates
and saturated
diols.
Polybutadiene and polyisoprene and copolymers thereof are known. Suitable
comonomers
include, for example, olefins, such as ethylene, propene, butene, hexene,
(meth)acrylates,
acrylonitrile, styrene and vinyl chloride. Polymers having (meth)acrylate
groups in the side
chain are also known. They may be, for example, reaction products of novolak-
based epoxy
resins with (meth)acrylic acid; homo- or co-polymers of vinyl alcohol or
hydroxyalkyl deriva-
CA 02314668 2000-07-27
-26-
tives thereof that have been esterified with (meth)acrylic acid; or homo- and
co-polymers of
(meth)acrylates that have been esterified with hydroxyalkyl (meth)acrylates.
The photopolymerisable compounds (A) may be used on their own or in any
desired mix-
tures. Preference is given to mixtures of polyol (meth)acrylates.
Binders may also be added to the compositions according to the invention, this
being espe-
cially advantageous when the photopolymerisable compounds are liquid or
viscous sub-
stances. The amount of binder may be, for example, from 5 to 95 % by weight,
preferably
from 10 to 90 % by weight and especially from 40 to 90 % by weight, based on
total solids.
The binder will be selected according to the field of use and the properties
required therefor,
such as developability in aqueous and organic solvent systems, adhesion to
substrates and
sensitivity to oxygen.
Suitable binders are, for example, polymers having a molecular weight of
approximately from
5000 to 2 000 000, preferably from 10 000 to 1 000 000. Examples thereof are:
homo- and
co-polymers of acrylates and methacrylates, for example copolymers of methyl
meth-acryl-
ate/ethyl acrylate/methacrylic acid, poly(methacrylic acid alkyl esters),
poly(acrylic acid alkyl
esters); cellulose esters and ethers, such as cellulose acetate, cellulose
acetate butyrate,
methyl cellulose, ethyl cellulose; polyvinyl butyral, polyvinylformal,
cyclised rubber, polyeth-
ers, such as polyethylene oxide, polypropylene oxide, polytetrahydrofuran;
polystyrene, poly-
carbonate, polyurethane, chlorinated polyolefins, polyvinyl chloride,
copolymers of vinyl chlo-
ride/vinylidene chloride, copolymers of vinylidene chloride with
acrylonitrile, methyl meth-
acrylate and vinyl acetate, polyvinyl acetate, copoly(ethylenelvinyl acetate),
polymers such
as polycaprolactam and poly(hexamethyleneadipamide), polyesters such as
polyethylene
glycol terephthalate) and poly(hexamethylene glycol succinate).
The resins mentioned below under (C1 ) may also be used as component (A), that
is to say
as UV-curable component. Of particular interest are, for example, unsaturated
acrylates
having reactive functional groups. The reactive functional group may be
selected, for exam-
ple, from a hydroxyl, thiol, isocyanate, epoxy, anhydride, carboxyl, amino or
blocked amino
group. Examples of OH-group-containing unsaturated acrylates are hydroxyethyl
and hy-
droxybutyl acrylates and also glycidyl acrylates.
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The unsaturated compounds may also be used in admixture with non-
photopolymerisable
film-forming components. These may be, for example, polymers that can be dried
physically
or solutions thereof in organic solvents, such as nitrocellulose or cellulose
acetobutyrate.
They may alternatively be chemically or thermally curable resins, such as
polyisocyanates,
polyepoxides or melamine resins. The concomitant use of thermally curable
resins is im-
portant for use in so-called hybrid systems which are both photopolymerised
and thermally
crosslinked.
Component (A) may, for example, be a coating composition comprising
(A1 ) compounds having one or more free-radically polymerisable double bonds
that addi-
tionally contain at least one further functional group that is reactive in
terms of an addition
and/or condensation reaction (examples are given above),
(A2) compounds having one or more free-radically polymerisable double bonds
that addi-
tionally contain at least one further functional group that is reactive in
terms of an addition
and/or condensation reaction, the additional reactive functional group being
complementary
or reactive towards the additional reactive functional groups of component (A1
),
(A3) optionally at least one monomeric, oligomeric and/or polymeric compound
having at
least one functional group that is reactive in terms of an addition and/or
condensation reac-
tion towards the functional groups of component (A1 ) or component (A2) that
are present in
addition to the free-radically polymerisable double bonds.
Component (A2) in each case carries the groups complementary or reactive
towards compo-
nent (A1 ). Different types of functional groups may also be present in a
component. Com-
ponent (A3) provides a further component that contains functional groups that
are reactive in
terms of an addition andlor condensation reaction and that are able to react
with the func-
tional groups of (A1 ) or (A2) that are present in addition to the free-
radically polymerisable
double bonds. Component (A3) contains no free-radically polymerisable double
bonds. Ex-
amples of such combinations (A1 ), (A2), (A3) can be found in WO 99/55785.
Examples of suitable reactive functional groups are selected, for example,
from hydroxyl,
isocyanate, epoxy, anhydride, carboxyl and blocked amino groups. Examples have
been
described above.
Constituents of component (C) are, for example, thermally curable lacquer or
coating system
constituents customary in the art. Component (C) accordingly may consist of a
number of
constituents.
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Examples of component (C) are, for example, oligomers and/or polymers derived
from a,~3-
unsaturated acids and derivatives thereof, for example polyacrylates and
polymethacrylates,
polymethyl methacrylates impact-resistant-modified with butyl acrylate,
polyacrylamides and
polyacrylonitriles. Further examples of component (C) are urethanes,
polyurethanes derived
from on the one hand polyethers, polyesters and polyacrylates having free
hydroxyl groups
and on the other hand aliphatic or aromatic polyisocyanates, and pre-products
thereof.
Component (C) accordingly also includes, for example, crosslinkable acrylic
resins derived
from substituted acrylic acid esters, for example epoxy acrylates, urethane
acrylates and po-
lyester acrylates. Alkyd resins, polyester resins and acrylate resins and
modifications thereof
that are crosslinked with melamine resins, urea resins, isocyanates,
isocyanurates, polyiso-
cyanates, polyisocyanurates and epoxy resins, may also be a constituent of
component (C).
Component (C) is, for example, generally a film-forming binder based on a
thermoplastic or
thermocurable resin, predominantly on a thermocurable resin. Examples thereof
are alkyd,
acrylic, polyester, phenol, melamine, epoxy and polyurethane resins and
mixtures thereof.
Examples thereof are described, for example, in Ullmann's Encyclopedia of
Industrial Chem-
istry, 5th Ed., Vol. A18, pp. 368-426, VCH, Weinheim 1991.
Component (C) may be a cold-curable or hot-curable binder, with the addition
of a curing
catalyst possibly being advantageous. Suitable catalysts that accelerate the
full cure of the
binder are described, for example, in Ullmann's Encyclopedia of Industrial
Chemistry, Vol.
A18, page 469, VCH Verlagsgesellschaft, Weinheim 1991.
Examples of specific binders suitable as component (C) are:
1. surface-coatings based on cold- or hot-crosslinkable alkyd, acrylate,
polyester, epoxy or
melamine resins or mixtures of such resins, optionally with the addition of a
curing catalyst;
2. two-component polyurethane surface-coatings based on hydroxyl-group-
containing acry-
late, polyester or polyether resins and aliphatic or aromatic isocyanates,
isocyanurates or
polyisocyanates;
3. one-component polyurethane surface-coatings based on blocked isocyanates,
isocyanu-
rates or polyisocyanates, which are de-blocked during stoving; it is also
possible to add
melamine resins as appropriate;
4. one-component polyurethane surface-coatings based on aliphatic or aromatic
urethanes
or polyurethanes and hydroxyl-group-containing acrylate, polyester or
polyether resins;
CA 02314668 2000-07-27
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5. one-component polyurethane surface-coatings based on aliphatic or aromatic
urethane
acrylates or polyurethane acrylates having free amine groups in the urethane
structure and
melamine resins or polyether resins, optionally with the addition of a curing
catalyst;
6. two-component surface-coatings based on (poly)ketimines and aliphatic or
aromatic iso-
cyanates, isocyanurates or polyisocyanates;
7. two-component surface-coatings based on (poly)ketimines and an unsaturated
acrylate
resin or a polyacetoacetate resin or a methacrylamidoglycolate methyl ester;
8. two-component surface-coatings based on carboxyl- or amino-group-containing
polyacry-
lates and polyepoxides;
9. two-component surface-coatings based on anhydride-group-containing acrylate
resins
and a polyhydroxy or polyamino component;
10. two-component surface-coatings based on acrylate-containing anhydrides and
polyepoxides;
11. two-component surface-coatings based on (poly)oxazolines and anhydride-
group-
' containing acrylate resins or unsaturated acrylate resins or aliphatic or
aromatic isocyanates,
isocyanurates or polyisocyanates;
12. two-component surface-coatings based on unsaturated polyacrylates and
polyma-
lonates;
13. thermoplastic polyacrylate surface-coatings based on thermoplastic
acrylate resins or
extrinsically crosslinking acrylate resins in combination with etherified
melamine resins;
14. surface-coating systems based on urethane (meth)acrylate having
(meth)acryloyl groups
and free isocyanate groups and on one or more compounds that react with
isocyanates, for
example free or esterified polyols. Such systems have been published, for
example, in EP
928800.
Blocked isocyanates, as may also be used in component (C), are described, for
example, in
Organischer Metallschutz: Entwicklung and Anwendung von Beschichtungsstoffen,
pages
159-160, Vincentz Verlag, Hanover (1993). These are compounds in which the
highly reac-
tive NCO group is "blocked" by reaction with specific radicals, for example
primary alcohols,
phenol, acetoacetic ester, ~-caprolactam, phthalimide, imidazole, oxime or
amine. The
blocked isocyanate is stable in liquid systems and also in the presence of
hydroxy groups.
Upon heating, the blocking agent is removed again and the NCO group is freed.
CA 02314668 2000-07-27
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1-Component (1 C) and 2-component (2C) systems may be used as component (C).
Exam-
ples of such systems are described in Ullmann's Encyclopedia of Industrial
Chemistry, Vol.
A18, Paints and Coatings, pages 404-407, VCH Verlagsgesellschaft mbH, Weinheim
(1991 ).
It is possible to optimise the composition by specially adapting the
formulation, for example
by varying the binder/crosslinking agent ratio. Such measures will be known to
the person
skilled in the art of surface-coating technology.
In the curing process according to the invention, component (C) is preferably
a mixture
based on acrylate/melamine (and melamine derivates), 2-component polyurethane,
1-component polyurethane, 2-component epoxy/carboxy or 1-component
epoxy/carboxy.
Mixtures of those systems are also possible, for example the addition of
melamine (or de-
rivatives thereof) to 1-component polyurethanes.
Component (C) is preferably a binder based on a polyacrylate with melamine or
on a mela-
mine derivative. Preference is also given to a system based on a polyacrylate
andlor poly-
ester polyol with an unblocked polyisocyanate or polyisocyanurate.
Component (C) may also comprise monomeric and/or oligomeric compounds having
eth-
ylenically unsaturated bonds (prepolymers) that additionally contain at least
one or more OH,
NH2, COOH, epoxy or NCO groups (= C1 ) that are capable of reaction with the
binder and/or
the crosslinking agent constituent of component (C). After application and
thermal curing,
the ethylenically unsaturated bonds are converted to a crosslinked, high
molecular weight
form by UV radiation. Examples of such components (C) are described, for
example, in the
above-mentioned publication, Ullmann's Encyclopedia of Industrial Chemistry,
5th Ed., Vol.
A18, pages 451-453, or by S. Urano, K. Aoki, N. Tsuboniva and R. Mizuguchi in
Progress in
Organic Coatings, 20 (1992), 471-486, or by H. Terashima and O. Isozaki in
JOCCA 1992
(6), 222.
(C1 ) may, for example, be an OH-group-containing unsaturated acrylate, for
example hy-
droxyethyl or hydroxybutyl acrylate or a glycidyl acrylate. Component (C1 )
may be of any
desired structure (for example it may contain units of polyester,
polyacrylate, polyether, etc..),
provided that it contains an ethylenically unsaturated double bond and
additionally free OH,
COOH, NH2, epoxy or NCO groups.
CA 02314668 2000-07-27
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(C1 ) may, for example, also be obtained by reacting an epoxy-functional
oligomer with acrylic
acid or methacrylic acid. A typical example of an OH-functional oligomer
having vinylic dou-
ble bonds is
O IH OH
CH3 I O
CH2=CH-C-OCH2 CH-CH2 O ~-~ C ~-~ O-CHz CH-CH20-C-CH=CHZ obtained by reaction
CH3
of CH2=CHCOOH Wlth HZC CH-CHZ-O ~-~ CH3 ~-~ O-CHZ CHO\CH2 ,
CH3
Another possible method of preparing component (C1 ) is, for example, the
reaction of an oli-
gomer that contains only one epoxy group and has a free OH group at another
position in the
molecule.
The quantity ratio of components (A) to (C) in the UV- and thermally-
crosslinking formula-
tions is not critical. "Dual-cure" systems are known to the person skilled in
the art, who will
therefore be familiar with the optimum ratios of the UV- and thermally-
crosslinkable compo-
nents for a particular desired use. For example, compositions may contain
components (A)
and (C), for example, in a ratio of from 5:95 to 95:5, from 20:80 to 80:20 or
from 30:70 to
70:30, for example from 40:60 to 60:40.
Examples of "dual-cure" systems, that is to say systems comprising both UV-
curable and
thermally curable components, can be found inter aiia in US 5 922 473, columns
6 to 10.
It is also possible to add solvent or water to the compositions used in the
process according
to the invention. If the compositions are used without solvent, they are, for
example, powder
coating formulations. Suitable solvents are solvents known to the person
skilled in the art,
especially those customary in surface-coating technology. Examples thereof are
various or-
ganic solvents, such as ketones, for example methyl ethyl ketone,
cyclohexanone; aromatic
hydrocarbons, for example toluene, xylene and tetramethylbenzene; glycol
ethers, such as
diethylene glycol monoethyl ether, dipropylene glycol diethyl ether; esters,
for example ethyl
acetate; aliphatic hydrocarbons, such as hexane, octane, decane; and petroleum
solvents,
for example petroleum ether.
The compounds and mixtures thereof according to the invention may also be used
as free-
radical photoinitiators or photoinitiating systems for radiation-curable
powder coating compo-
sitions. The powder coating compositions may be based on solid resins and
monomers
CA 02314668 2000-07-27
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containing reactive double bonds, for example maleates, vinyl ethers,
acrylates, acryl-amides
and mixtures thereof. A free-radically UV-curable powder coating composition
can be for-
mulated by mixing unsaturated polyester resins with solid acrylamides (for
example methyla-
crylamidoglycolate methyl ester) and a free-radical photoinitiator according
to the invention,
as described, for example, in the presentation "Radiation Curing of Powder
Coating", Con-
ference Proceedings, Radtech Europe 1993 by M. Wittig and Th. Gohmann. Free-
radically
UV-curable powder coating compositions can also be formulated by mixing
unsaturated
polyester resins with solid acrylates, methacrylates or vinyl ethers and a
photoinitiator (or
photoinitiator mixture) according to the invention. The powder coating
compositions may
also comprise binders, as described, for example, in DE 4228514 and EP 636669.
The
powder coating formulations described in EP 636669 comprise, for example,
a) an unsaturated resin from the group of (semi)crystalline or amorphous
unsaturated polyes-
ters, unsaturated polyacrylates or mixtures thereof with unsaturated
polyesters, special pref-
erence being given to those derived from malefic acid or fumaric acid; b) an
oligomeric or
polymeric crosslinking agent having vinyl ether-, vinyl ester- or
(meth)acrylate-functional
groups, special preference being given to vinyl ether oligomers, such as
divinyl-ether-
functionalised urethanes; c) the photoinitiator.
The UV-curable powder coating compositions may also comprise white or coloured
pig-
ments. Thus, for example, especially rutile titanium dioxide can be used in
concentrations of
up to 50 % by weight in order to obtain a cured powder coating having good
covering power.
The process normally comprises spraying the powder electrostatically or
tribostatically onto
the substrate, for example metal or wood, melting the powder by heating and,
once a smooth
film has been produced, radiation-curing the coating with ultraviolet and/or
visible light, for
example using medium-pressure mercury lamps, metal halide lamps or xenon
lamps. A par-
ticular advantage of radiation-curable powder coating compositions over
corresponding
thermally curable powder coating compositions is that the flow time after the
powder particles
have been melted can be prolonged as desired to ensure the formation of a
smooth high-
gloss coating. Unlike thermally curable systems, radiation-curable powder
coating composi-
tions can be so formulated that they melt at relatively low temperatures,
without the undesir-
able effect of their useful life being shortened. For that reason they are
also suitable as
coatings for heat-sensitive substrates, such as wood or plastics.
If the powder coating compositions are to be applied to substrates that are
not heat-sensitive,
for example to metals (automotive coatings), it is also possible to provide
"dual cure" powder
coating formulations using the photoinitiators according to the invention.
Such formulations
CA 02314668 2000-07-27
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are known to the person skilled in the art and are both thermally cured and UV-
cured. Such
formulations can be found, for example, in US 5 922 473.
The powder coating formulations may also comprise UV-absorbers in addition to
the photo-
initiators according to the invention. Suitable examples thereof are listed
below.
The photopolymerisable mixtures may comprise various additives (D) in addition
to the pho-
toinitiator. Examples thereof are thermal inhibitors, the purpose of which is
to prevent pre-
mature polymerisation, for example hydroquinone, hydroquinone derivatives, p-
methoxyphenol, [3-naphthol and sterically hindered phenols, for example 2,6-
di(tert-butyl)-p-
cresol. In order to increase stability to dark storage, it is possible, for
example, to use copper
compounds, such as copper naphthenate, stearate or octoate, phosphorus
compounds, for
example triphenylphosphine, tributylphosphine, triethyl phosphite, triphenyl
phosphite or
tribenzyl phosphite, quaternary ammonium compounds, for example
tetramethylammonium
chloride or trimethylbenzylammonium chloride, or hydroxylamine derivatives,
for example N-
i diethylhydroxylamine. In order to exclude atmospheric oxygen during
polymerisation, it is
possible to add paraffin or similar wax-like substances that, being
insufficiently soluble in the
polymer, migrate to the surface at the beginning of the polymerisation and
form a transparent
surface layer which prevents the ingress of air. Equally possible is the
application of an oxy-
gen-impermeable layer. UV-Absorbers, for example of the hydroxyphenyl-
benzotriazole, hy-
droxyphenyl-benzophenone, oxalic acid amide or hydroxyphenyl-s-triazine type,
may be
added as light stabilisers. Individual compounds or mixtures of those
compounds may be
used with or without the use of sterically hindered amines (HALS).
Examples of such UV-absorbers and light stabilisers are
1. 2-(2'-Hydroxyphenyl)benzotriazoles, for example 2-(2'-hydroxy-5'-
methylphenyl)benzo-
triazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(5'-tert-
butyl-2'-hydroxy-phe-
nyl)benzotriazole, 2-(2'-hydroxy-5'-(1,1,3,3-
tetramethylbutyl)phenyl)benzotriazole, 2-(3',5'-di-
tert-butyl-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-
hydroxy-5'-methylphe-
nyl)-5-chloro-benzotriazole, 2-(3'-sec-butyl-5'-tert-butyl-2'-
hydroxyphenyl)benzo-triazole, 2-
(2'-hydroxy-4'-octyloxyphenyl)benzotriazole, 2-(3',5'-di-tert-amyl-2'-hydroxy-
phenyl)benzotri-
azole, 2-(3',5'-bis-(a,a-dimethylbenzyl)-2'-hydroxyphenyl)benzotriazole, 2-(3'-
tert-butyl-2'-hy-
droxy-5'-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3'-tert-
butyl-5'-[2-(2-eth-
ylhexyloxy)-carbonylethyl]-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3'-
tert-butyl-2'-hydr-
oxy-5'-(2-methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3'-tert-
butyl-2'-hydroxy-5'-
(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-
(2-octyloxycarbo-
CA 02314668 2000-07-27
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nylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyl-
oxy)carbonylethyl]-2'-hydrox-
yphenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-5'-methyl-
phenyl)benzotriazole, 2-(3'-tert-bu-
tyl-2'-hydroxy-5'-(2-isooctyloxycarbonylethyl)-phenyl-benzotriazole, 2,2'-
methylene-bis[4-(1,-
1,3,3-tetramethylbutyl)-6-benzotriazol-2-yl-phenol]; the transesterification
product of 2-[3'-tert-
butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxyphenyl]-2H-benzotriazole with
polyethylene gly-
col 300; [R-CH2CH2-COO-CH2CH2]2- where R = 3'-tert-butyl-4'-hydroxy-5'-2H-
benzotriazol-2-
ylphenyl, 2-[2'-hydroxy-3'-(a,a-dimethylbenzyl)-5'-(1,1,3,3-tetramethylbutyl)-
phenylJbenz-
otriazole; 2-[2'-hydroxy-3'-(1,1,3,3-tetramethylbutyl)-5'-(a,a-dimethylbenzyl)-
phenyl]benzotri-
azole.
2. 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-
decyloxy,
4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and 2'-hydroxy-4,4'-dimethoxy
derivatives.
3. Esters of substituted and unsubstituted benzoic acids, as for example 4-
tert-butyl-phenyl
salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol,
bis(4-tert-butylben-
zoyl) resorcinol, benzoyl resorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-
butyl-4-hydroxybenzo-
ate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-
butyl-4-hydroxyben-
zoate, 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.
4. Acrylates, for example ethyl a-cyano-[i,[3-diphenylacrylate, isooctyl a-
cyano-[i,[i-diphenyl-
acrylate, methyl a-methoxycarbonylcinnamate, methyl a-cyano-a-methyl-p-methoxy-
cinna-
mate, butyl a-cyano-[i-methyl-p-methoxy-cinnamate, methyl a-methoxycarbonyl-p-
methoxy-
cinnamate and N-([i-methoxycarbonyl-~-cyanovinyl)-2-methylindoline.
5. Sterically hindered amines, for example bis(2,2,6,6-tetramethyl-4-
piperidyl)sebacate, bis-
(2,2,6,6-tetramethyl-4-piperidyl)succinate, bis(1,2,2,6,6-pentamethyl-4-
piperidyl)-sebacate,
bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-yenta-
methyl-4-piperid-
yl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of 1-(2-
hydroxyethyl)-
2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, linear or cyclic
condensates of
N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-
octylamino-2,6-di-
chloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate,
tetrakis(2,2,6,6-tetra-
methyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate, 1,1'-(1,2-ethane-diyl)-
bis(3,3,5,5-tetra-
methylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyl-oxy-
2,2,6,6-tetrame-
thylpiperidine, bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-
di-tert-butylben-
zyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro-[4.5]decane-2,4-
dione, bis(1-oct-
yloxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis(1-octyloxy-2,2,6,6-
tetramethylpiperidyl)suc-
cinate, linear or cyclic condensates of N,N'-bis-(2,2,6,6-tetramethyl-4-
piperidyl)hexamethyle-
nediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of 2-
chloro-4,6-bis-
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(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine and 1,2-bis(3-
aminopropylamino)-
ethane, the condensate of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-
pentamethylpiperidyl)-
1,3,5-triazine and 1,2-bis(3-aminopropyl-amino)ethane, 8-acetyl-3-dodecyl-
7,7,9,9-tetrame-
thyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethyl-
4-piperidyl)pyr-
rolidine-2,5-dione, 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-
2,5-dione, a
mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, a
condensation
product of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-
cyclohexyl-
amino-2,6-dichloro-1,3,5-triazine, a condensation product of 1,2-bis(3-
aminopropylamino)eth-
ane and 2,4,6-trichloro-1,3,5-triazine as well as 4-butylamino-2,2,6,6-
tetramethylpiperidine
(CAS Reg. No. [136504-96-6]); N-(2,2,6,6-tetramethyl-4-piperidyl)-n-
dodecylsuccinimide, N-
(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimide, 2-undecyl-7,7,9,9-
tetramethyl-1-
oxa-3,8-diaza-4-oxo-spiro(4,5]decane, a reaction product of 7,7,9,9-
tetramethyl-2-cyclounde-
cyl-1-oxa-3,8-diaza-4-oxospiro[4,5]decane and epichlorohydrin, 1,1-
bis(1,2,2,6,6-pentame-
thyl-4-piper-idyloxycarbonyl)-2-(4-methoxyphenyl)ethene, N,N'-bis-formyl-N,N'-
bis(2,2,6,6-te-
tra-methyl-4-piperidyl)hexamethylenediamine, diester of 4-methoxy-methylene-
malonic acid
with 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, poly[methylpropyl-3-oxy-4-
(2,2,6,6-tetrame-
thyl-4-piperidyl)]siloxane, reaction product of malefic acid anhydride-a-
olefin-copolymer with
2,2,6,6-tetramethyl-4-aminopiperidine or 1,2,2,6,6-pentamethyl-4-
aminopiperidine.
6. Oxamides, for example 4,4'-dioctyloxyoxanilide, 2,2'-diethoxyoxanilide,
2,2'-dioctyloxy-5,5'-
di-tert-butoxanilide, 2,2'-didodecyloxy-5,5'-di-tert-butoxanilide, 2-ethoxy-2'-
ethyloxanilide,
N,N'-bis(3-dimethylaminopropyl)oxamide, 2-ethoxy-5-tert-butyl-2'-ethoxanilide
and its mixture
with 2-ethoxy-2'-ethyl-5,4'-di-tert-butoxanilide, mixtures of o- and p-methoxy-
disubstituted ox-
anilides and mixtures of o- and p-ethoxy-disubstituted oxanilides.
7. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-
octyloxyphenyl)-
1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-
1,3,5-triazine, 2-
(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-
hydroxy-4-propyl-
oxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-
octyloxyphenyl)-4,6-bis(4-
methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-
dimethylphenyl)-
1,3,5-triazine, 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis{2,4-dimethylphenyl)-
1,3,5-triazine, 2-
(2-hydroxy-4-(2-hydroxy-3-butyloxy-propoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-
triazine, 2-[2-
hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-
triazine, 2-[4-
(dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxy-phenyl]-4,6-bis(2,4-
dimethyl-phenyl)-
1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxy-propoxy)phenyl]-4,6-
bis(2,4-dimethyl-
phenyl)-1,3,5-triazine, 2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-
triazine, 2-(2-hy-
droxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3-
butoxy-2-hy-
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droxy-propoxy)phenyl]-1,3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-
6-phenyl-
1,3,5-triazine, 2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-
hydroxypropyloxy]phenyl}-4,6-bis(2,4-
dimethylphenyl)-1,3,5-triazine.
8. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl
alkyl phosphites,
phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite,
trioctadecyl phos-
phate, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl)
phosphate, diisodecyl
pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol
diphosphite, bis(2,6-di-
tert-butyl-4-methylphenyl)-pentaerythritol diphosphite,
diisodecyloxypentaerythritol diphos-
phite, bas(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite,
bis(2,4,6-tris(tert-butyl-
phenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite,
tetrakis(2,4-di-tert-butyl-
phenyl) 4,4'-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-
butyl-12H-dibenz-
[d,g]-1,3,2-dioxaphosphocine, bas(2,4-di-tert-butyl-6-methylphenyl) methyl
phosphate, bis(2,4-
di-tert-butyl-6-methylphenyl) ethyl phosphate, 6-fluoro-2,4,8,10-tetra-tert-
butyl-12-methyl-di-
benz[d,g]-1,3,2-dioxaphosphocine, 2,2',2"-nitrilo[triethyltris(3,3',5,5'-tetra-
tert-butyl-1,1'-biphe-
nyl-2,2'-diyl)phosphite], 2-ethylhexyl(3,3',5,5'-tetra-tert-butyl-1,1'-
biphenyl-2,2'-diyl)phosphite,
5-butyl-5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxaphosphirane.
Additives customary in the art, such as antistatics, flow improvers, levelling
agents and ad-
hesion promoters, may also be used.
The photoinitiators of formula I provided with siloxane radicals can also
serve as flow im-
provers since they are oriented towards the surface and influence the surface
properties by
way of the siloxane radical. It is also possible to add further flow improvers
customary in the
art. Examples thereof are siloxane compounds and fluorohydrocarbon compounds,
such as
are widely available commercially.
The invention relates also to the use of compounds of formula I as flow
improvers, optionally
in combination with other customary flow improvers.
Flow is defined, according to DIN 55945, as "the ability, to a greater or
lesser degree, of a
still liquid paint to level out, by itself, any unevenness arising during its
application" (see J.
Bielemann, Lackadditive, VCH Weinheim 1998, Chapter 6). The flow of a coating
composi-
tion is highly dependent upon its flow behaviour and its surface tension. The
term "flow im-
prover" is used to denote a substance that, by lowering the viscosity andlor
the surface ten-
sion, enables wet coatings to become evenly flowing films. In the case of
powder coating
compositions, flow improvers also lower the melt viscosity and the glass
transition tempera-
ture, and they also act as de-gassing agents. The use of flow improvers
eliminates flow and
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surface faults that impair the overall appearance of the coating. Flow and
surface faults in-
clude, inter alia, orange peel effect, structure formation, scratching,
fisheye formation, sensi-
tivity to draught, substrate wetting problems, brush application marks, run
formation, stip-
pling, pinholes, etc.. The use of the compounds according to the invention as
flow improvers
enables the surface tension to be lowered. The surface tension can be
calculated by deter-
mining the wetting angle of a drop of liquid on a surface (contact angle
measurement).
In order to accelerate the photopolymerisation it is possible to add as
further additives (D)
amines, for example triethanolamine, N-methyl-diethanolamine, p-
dimethylaminobenzoic
acid ethyl ester or Michler's ketone. The action of the amines can be enhanced
by the addi-
tion of aromatic ketones of the benzophenone type. Amines that can be used as
oxygen
capture agents are, for example, substituted N,N-dialkylanilines, as described
in EP 339841.
Further accelerators, co-initiators and auto-oxidizers are thiols, thin
ethers, disulfides and
phosphines, as described, for example, in EP 438123 and GB 2180358.
It is also possible to add to the compositions according to the invention
chain-transfer rea-
gents customary in the art, examples of which are mercaptans, amines and
benzothiazole.
Photopolymerisation can also be accelerated by adding as further additives (D)
photosensi-
tisers that shift or broaden the spectral sensitivity. These include
especially aromatic car-
bonyl compounds, such as benzophenone and thioxanthone, especially also
isopropylthiox-
anthone, anthraquinone and 3-acylcoumarin derivatives, terphenyls, styryl
ketones, and 3-
(aroylmethylene)-thiazolines, camphorquinone, and also eosin, rhodamine and
erythrosine
dyes.
The above-mentioned amines may, for example, also be regarded as
photosensitisers.
The curing process, especially in the case of pigmented compositions (for
example composi-
tions pigmented with titanium dioxide) may also be assisted by the use of an
additional addi-
tive (D) that is a component that forms free radicals under thermal
conditions, for example an
azo compound, such as 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), a
triazene, diazo-
sulfide, pentaazadiene or a peroxy compound, such as a hydrogen peroxide or
peroxycar-
bonate, for example tert-butyl hydroperoxide, as described, for example, in EP
245639.
The compositions may also comprise as further additives (D), for example, a
photoreducible
dye, for example xanthene, benzoxanthene, benzothioxanthene, thiazine,
pyronine, porphy-
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rin or acridine dyes, andlor a radiation-cleavable trihalomethyl compound.
Similar composi-
tions are described, for example, in EP 445624.
Further customary additives (D) are - depending upon the intended use -
optical brighteners,
fillers, for example kaolin, talcum, barytes, gypsum, chalk or silicate-like
fillers, pigments,
dyes, wetting agents and flow improvers.
For the curing of thick and pigmented coatings it is suitable to add glass
microbeads or pul-
verised glass fibres, as described, for example, in US 5013768.
The formulations may also comprise colourants and/or white or coloured
pigments. De-
pending upon the intended use, both inorganic and organic pigments may be
used. Such
additives are known to the person skilled in the art; some examples thereof
are titanium di-
oxide pigments, for example of the rutile or anatase type, carbon black, zinc
oxide, such as
zinc white, iron oxides, such as iron oxide yellow, iron oxide red, chromium
yellow, chromium
green, nickel titanium yellow, ultramarine blue, cobalt blue, bismuth
vanadate, cadmium yel-
low and cadmium red. Examples of organic pigments are mono- and bis-azo
pigments, and
metal complexes thereof, phthalocyanine pigments, polycyclic pigments, such as
perylene,
anthraquinone, thioindigo, quinacridone and triphenylmethane pigments, and
diketo-pyrrolo-
pyrrole, isoindolinone, for example tetrachloroisoindolinone, isoindoline,
dioxazine, benzimi-
dazolone and quinophthalone pigments.
The pigments may be used individually or in admixture in the formulations.
Depending upon the intended use, the pigments are added to the formulations in
amounts
customary in the art, for example in an amount of from 1 to 60 % by weight, or
from 10 to 30
by weight, based on the total weight.
The formulations may, for example, also comprise organic colourants of a wide
variety of
classes, examples of which are azo dyes, methine dyes, anthraquinone dyes and
metal
complex dyes. Customary concentrations are, for example, from 0.1 to 20 %,
especially from
1 to 5 %, based on the total weight.
The choice of additives will depend upon the field of use in question and upon
the properties
desired for that field. The additives (D) described above are customary in the
art and are ac-
cordingly used in amounts customary in the art.
In certain cases it may be advantageous to use mixtures of two or more of the
photoinitiators
of formula I; for example it is advantageous to use mixtures formed directly
during prepara-
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tion. It is, of course, also possible to use mixtures with known
photoinitiators (E), for example
mixtures with camphorquinone, benzophenone, benzophenone derivatives,
acetophenone,
acetophenone derivatives, such as a-hydroxycycloalkylphenylketones or 2-
hydroxy-2-methyl-
1-phenyl-propanone, dialkoxyacetophenones, a-hydroxy- or a-amino-
acetophenones, for ex-
ample (4-methylthiobenzoyl)-1-methyl-1-morpholino-ethane, (4-morpholino-
benzoyl)-1-
benzyl-1-dimethylamino-propane, 4-aroyl-1,3-dioxolanes, benzoin alkyl ethers
and benzil
ketals, for example benzil dimethyl ketal, phenyl glyoxalates and derivatives
thereof, dimeric
phenyl glyoxalates, peresters, for example benzophenone tetracarboxylic acid
peresters, as
described, for example, in EP 126541, monoacylphosphine oxides, for example
(2,4,6-
trimethylbenzoyl)-phenyl-phosphine oxide, bisacylphosphine oxides, for example
bis(2,6-
dimethoxybenzoyl)-(2,4,4-trimethyl-pent-1-yl)phosphine oxide, bis(2,4,6-
trimethyibenzoyl)-
phenyl-phosphine oxide or bis(2,4,6-trimethylbenzoyl)-(2,4-
dipentoxyphenyl)phosphine ox-
ide, trisacylphosphine oxides, halomethyltriazines, for example 2-[2-(4-
methoxy-phenyl)-
vinyl]-4,6-bis-trichloromethyl-[1,3,5]triazine, 2-(4-methoxy-phenyl)-4,6-bis-
trichloromethyl-
[1,3,5]triazine, 2-(3,4-dimethoxy-phenyl)-4,6-bis-trichloro-methyl-
[1,3,5]triazine, 2-methyl-4,6-
bis-trichloromethyl-[1,3,5]triazine, hexaarylbisimidazole/co-initiator
systems, for example or-
tho-chlorohexaphenyl-bisimidazole together with 2-mercaptobenzothiazole,
ferrocenium
compounds or titanocenes, for example dicyclopentadienyl-bis(2,6-difluoro-3-
pyrrolo-
phenyl)titanium or borate photoinitiators.
When the photoinitiators according to the invention are used in hybrid
systems, that is to say
in systems that are both free-radically and cationically curable, in addition
to the free-radical
hardeners of formula I and optionally further free-radical hardeners there are
used cationic
photoinitiators, for example benzoyl peroxide (other suitable peroxides are
described in
US 4950581, column 19, lines 17-25), aromatic sulfonium, phosphonium or
iodonium salts,
as described, for example, in US 4950581, column 18, line 60 to column 19,
line 10.
The photopolymerisable compositions contain the photoinitiator advantageously
in an
amount of from 0.05 to 15 % by weight, preferably from 0.1 to 5 % by weight,
based on the
composition. The amount of photoinitiator indicated relates to the sum of all
the photoinitia-
tors added when mixtures thereof are used, that is to say either to the
photoinitiator (B) or to
the photoinitiators (B) + (E).
The photopolymerisable compositions may be used for a variety of purposes, for
example as
printing inks, as clear lacquer, as white surface-coating compositions, as
colour-pigmented
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surface-coating compositions, for example for wood or metal, as powder coating
composi-
tions, as paint, inter alia, for paper, wood, metal or plastics, as daylight-
curable paint for
marking structures and roads, for photographic reproduction processes, for
holographic re-
cording materials, for image recording processes or for the production of
printing plates that
are to be developed with organic solvents or using aqueous/alkaline media, in
the production
of masks for screen-printing, as dental filling compounds, as adhesives, as
pressure-
sensitive adhesives, as laminating resins, as etch resists or permanent
resists, liquid films
and dry films, as photostructurable dielectrics, and as solder masks for
electronic circuits, as
resists in the manufacture of colour filters for any type of screen or for
producing structures in
the manufacturing process of plasma displays and electroluminescent displays,
in the
manufacture of optical switches, optical gratings (interference gratings), in
the manufacture
of three-dimensional articles by means of bulk curing (UV-curing in
transparent moulds) or
using the stereolithography process, as described, for example, in US 4575330,
in the
manufacture of composites (e.g. styrene polyesters that may optionally include
glass fibres
andlor other fibres and other adjuvants) and other thick-layered compositions,
in the coating
or sealing of electronic components or as coatings for optical fibres. The
compositions are
also suitable for the manufacture of optical lenses, for example contact
lenses or Fresnel
lenses, and also in the manufacture of medical apparatus, aids or implants.
The compositions can also be used in the manufacture of gels having
thermotropic proper-
ties, as described, for example, in DE 19700064 and EP 678 534.
The compounds of formula I can also be used as initiators for emulsion, bead
or suspension
polymerisations or as initiators of a polymerisation for fixing the
orientation states of liquid
crystalline monomers and oligomers, and as initiators for fixing dyes on
organic materials.
The photocurable compositions according to the invention are suitable, for
example, as
coating materials for all kinds of substrates, for example wood, textiles,
paper, ceramics,
glass, plastics, such as polyesters, polyethylene terephthalate, polyolefins
or cellulose ace-
tate, especially in the form of films, and metals such as AI, Cu, Ni, Fe, Zn,
Mg or Co and
GaAs, Si or Si02, to which a protective layer is to be applied or an image is
to be applied by
image-wise exposure.
The coating of the substrates can be effected by applying a liquid
composition, a solution or
suspension to the substrate. The choice of solvent and the concentration are
governed
chiefly by the nature of the composition and by the coating method. The
solvent should be
CA 02314668 2000-07-27
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inert, that is to say it should not enter into any chemical reaction with the
components and it
should be capable of being removed again upon drying after the coating
operation. Exam-
ples of suitable solvents are ketones, ethers and esters, such as methyl ethyl
ketone, isobu-
tyl methyl ketone, cyclopentanone, cyclohexanone, N-methylpyrrolidone,
dioxane, tetrahy-
drofuran, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 1,2-
dimethoxyethane,
ethyl acetate, n-butyl acetate and ethyl 3-ethoxy-propionate.
The formulation is applied uniformly to a substrate by known coating methods,
for example
by spin-coating, immersion, knife coating, curtain pouring, brush application
or spraying, es-
pecially by electrostatic spraying and reverse-roll coating, and by
electrophoretic deposition.
It is also possible to apply the photosensitive layer to a temporary flexible
support and then
coat the final substrate by transferring the layer by lamination.
The amount applied (layer thickness) and the type of substrate (layer support)
are dependent
upon the desired field of use. The dry layer thickness range generally
includes values from
about 0.1 pm to more than 100 p.m, preferably from 0.02 to 2 cm.
A further field of use for photocuring is in metal coating, for example in the
surface-coating of
metal sheets and tubes, cans or bottle closures, and photocuring on plastics
coatings, for
example of PVC-based floor or wall coverings.
Examples of photocuring of paper coatings are the application of a colourless
surface-
coating to labels, record sleeves or book covers.
The photosensitivity of the compositions according to the invention generally
ranges from
about 200 nm to about 600 nm (UV field). Suitable radiation is present, for
example, in sun-
light or light from artificial light sources. Accordingly, a large number of
widely varying types
of light sources may be used. Point sources and also planiform radiators (lamp
carpets) are
suitable. Examples thereof include: carbon arc lamps, xenon arc lamps, medium-
, high- and
low-pressure mercury arc lamps, doped where appropriate with metal halides
(metal halide
lamps), microwave-excited metal vapour lamps, excimer lamps, superactinic
fluorescent
tubes, fluorescent lamps, argon incandescent lamps, flashlamps, photographic
flood lights,
light-emitting diodes (LED), electron beams and X-rays. The distance between
the lamp and
the substrate to be irradiated can vary according to the intended use and upon
the type and
strength of the lamp, and may be, for example, from 2 cm to 150 cm. Laser
light sources, for
example excimer lasers, such as Krypton F lasers for irradiation at 248 nm,
are especially
suitable. Lasers in the visible range can also be used.
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As already mentioned, in the process according to the invention curing can be
effected solely
by irradiation with electromagnetic radiation, but, depending upon the
composition of the
formulation to be cured, thermal curing before, during or after the
irradiation is advantageous.
The thermal curing is carried out according to methods known to the person
skilled in the art.
Curing is generally carried out in an oven, for example a circulating-air
oven, on a hotplate or
by irradiation with IR lamps. Curing at room temperature without aids is also
possible, de-
pending upon the binder system used. The curing temperatures are generally
from room
temperature to 150°C, for example from 25°C to 150°C or
from 50°C to 150°C. In the case
of powder coating compositions or "coil coat" surface-coatings, the curing
temperatures may
even be higher, for example up to 350°C.
According to the invention, when the formulation comprises thermally curable
components
(C) it is also possible to add thermal drying or curing catalysts as
additional additives (D) to
the formulation. Examples of possible drying catalysts, or thermal curing
catalysts, are or-
ganic metal compounds, amines and/or phosphines. Organic metal compounds are,
for ex-
ample, metal carboxylates, especially those of the metals Pb, Mn, Co, Zn, Zr
or Cu, or metal
chelates, especially those of the metals AI, Ti or Zr, or organometal
compounds, for example
organotin compounds. Examples of metal carboxylates are the stearates of Pb,
Mn or Zn,
the octoates of Co, Zn or Cu, the naphthenates of Mn and Co or the
corresponding linoleates
or tallates. Examples of metal chelates are the aluminium, titanium or
zirconium chelates of
acetylacetone, ethyl acetylacetate, salicylaldehyde, salicylaldoxime, o-
hydroxyacetophenone
or ethyl trifluoroacetylacetate and the alkoxides of those metals. Examples of
organotin
compounds are dibutyltin oxide, dibutyltin dilaurate and dibutyltin dioctoate.
Examples of
amines are especially tertiary amines, for example tributylamine,
triethanolamine, N-methyl-
diethanolamine, N-dimethylethanolamine, N-ethylmorpholine, N-methylmorpholine
or diaza-
bicyclooctane (triethylenediamine) and salts thereof. Further examples are
quaternary am-
monium salts, for example trimethylbenzylammonium chloride. Phosphines, for
example
triphenylphosphine, can also be used as curing catalyst. Suitable catalysts
are also de-
scribed, for example, in J. Bielemann, Lackadditive, Wiley-VCH Verlag GmbH,
Weinheim,
1998, pages 244-247. Examples thereof are carboxylic acids, such as p-
toluenesulfonic
acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid and
dinonylnaphthale-
nedisulfonic acid. Latent or blocked sulfonic acids may, for example, also be
used, it being
possible for the blocking of the acid to be ionic or non-ionic.
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Such catalysts are used in concentrations customary in the art and known to
the person
skilled in the art.
The invention relates also to a process for the photopolymerisation of non-
volatile mono-
meric, oligomeric or polymeric compounds having at least one ethylenically
unsaturated dou-
ble bond, in which process a composition as described above is irradiated with
electromag-
netic radiation in the range of from 200 nm to 600 nm.
The invention relates also to the use of the above-described composition and
to a process
for the preparation of pigmented and non-pigmented surface-coatings, powder
coating com-
positions, composites and glass fibre cable coatings.
The invention relates also to a coated substrate that is coated on at least
one surface with a
composition as described above.
The following Examples illustrate the invention further, but it is not
intended to limit the inven-
tion to the Examples. As in the remainder of the description and in the
claims, unless other-
wise indicated, parts and percentages relate to weight. Where mention is made
of alkyl radi-
cals having more than three carbon atoms without reference to the isomer, it
is always the n-
isomers that are intended.
Example A: Preparation of the photoinitiator unit
A-1: Preparation of phenyl isobutyrate ~~'C~H cHs
ii
O
In a flask equipped with a thermometer, cooling device and dropping funnel,
176.6 g of phe-
nol are cooled to 5°C under nitrogen. Over the course of 40 minutes,
250 g of iso-butylic
acid chloride are added dropwise, and the solution is stirred at 5°C
for one hour. The tem-
perature is increased to room temperature and stirring is continued for 2
hours. The mixture
is distilled (bp = 95-100°C (20 mbar)) and 298 g of the pure product
are obtained (97 %).
'H-NMR (CDC13) [ppm]: 7.39 (m, 2 H arom.); 7.22 (m, 1 H arom.); 7.10 (m, 2 H
arom.); 3.54
(q x q, J = 6.99, 1 H); 1.33 (d, J = 7.00, 6 H, 2 CH3).
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_ CH3
A-2: Preparation of 1-(4-hydroxyphenyl)-2-methyl-1-propanone Ho ~ / ~ H'cH
3
In a flask equipped with a thermometer, cooling device and dropping funnel,
580.8 g of alu-
minium chloride are added to 1 litre of chlorobenzene at 0-5°C under
nitrogen. The mixture
is stirred at room temperature for 45 minutes. 298 g of the product prepared
as described in
A.1 are added dropwise over the course of 45 minutes, the temperature being
maintained at
20-25°C. The resulting suspension is stirred at room temperature for 2
days. The mixture is
poured into a mixture of ice (3 kg) and hydrochloric acid (450 ml) and
extracted with toluene.
The organic phases are washed with salt water. After drying over MgS04 and
filtration, the
solvent is removed in vacuo. 1 litre of water is added to the residue, and the
pH value of the
solution is raised to 14 with 30 % sodium hydroxide solution, whilst
maintaining the tem-
perature at 20°C. The solution is extracted with ethyl acetate. The
aqueous phase is cooled
to 0°C and the pH value is adjusted to 0 with concentrated hydrochloric
acid, the organic
phase is dried over MgS04 and filtered and the solvent is removed in vacuo,
resulting in a
liquid which solidifies in a freezer. The pure product is obtained in the form
of a white solid
(213 g, 71 %).
'H-NMR (CDC13) [ppm]: 7.90 (m, 2 H arom.); 6.94 (m, 2 H arom.); 3.54 (q x q, J
= 6.84, 1 H);
1.20 (d, J = 6.82, 6 H, 2 CH3).
A-3: Preparation of 2-hydroxy-1-(4-hydroxy- o cH3
phenyl)-2-methyl-1-propanone Ho / ~ c~-~-off
CH3
A solution of 213 g of the product prepared in A.2 in 475 ml of dioxane is
cooled to 0°C.
228 g of bromine are added dropwise over the course of one hour, whilst
maintaining the
temperature at 10-15°C. The orange-coloured mixture is stirred at room
temperature for
2 hours. The solution is poured into water (5.4 litres) and extracted with
ethyl acetate. After
drying the organic phases over MgSOa and filtering, the solvent is removed in
vacuo, result-
ing in a brown oil. 3 litres of water are added to the oil, and the beige-
coloured emulsion that
forms is treated with 650 g of 30 % sodium hydroxide solution. The mixture is
stirred at room
temperature for 3 hours. 293 ml of concentrated HCI are then added to adjust
the pH value
of the solution to 7. The resulting white suspension is stirred at 0°C
for 4 hours and at room
temperature overnight. The mixture is then cooled to 5°C and filtered.
The crystals are
washed with water and dried in vacuo at 40°C. Initially 137.8 g are
obtained in the form of
dirty-white crystals. A further 47.8 g of a contaminated compound are obtained
from the ex-
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tracted mother liquor. Both products are purified in toluene and 135 g (58 %)
of pure product
and 27 g (12 %) of a product that is not quite pure are isolated.
'H-NMR (DMSOds) [ppm]: 10.23 (s, OH); 8.12 (m, 2 H arom.); 6.79 (m, 2 H
arom.); 5.59 (s,
OH); 1.37 (s, 6 H, 2 CH3). Microanalysis: calc.: C 66.65; H 6.71; found: C
65.60; H 6.52.
A_4: Preparation of 2-hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-propanone
(A4a)
and 2-methyl-2-(2-propenyloxy)-1-[4-(2-propenyloxy)phenyl]-1-propanone (A4b)
O CHs
H2C=C-C-O ~ ~ C-C-OH (A4a)
H H2
CH3
O CH3
HZC C C-O ~ ~ CI-C-O-H-H CH2 (A4b)
H H2 CH3 z
A solution of 75 g of the compound prepared as described in A.3 in 300 ml of
dimethyl sul-
foxide (DMSO) is added over the course of one hour, at room temperature under
argon, to a
suspension of NaH (20 g; 55-60 % in oil) in 950 ml of DMSO. The solution is
stirred for
15 minutes at room temperature and for a further 15 minutes at 35-40°C.
A solution of
38.7 ml of allyl bromide in 75 ml of DMSO is added over the course of 15
minutes and the
resulting mixture is heated at 45°C for 30 minutes. The orange-coloured
mixture is poured
into an ice/water mixture (2.5 litres) and extracted with tert-butyl methyl
ether. The organic
phases are washed with water and dried over magnesium sulphate. Filtration,
removal of the
solvent by evaporation and chromatography (eluant hexane/ethyl acetate 5:1 to
4:1 ) yield 2-
hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-propanone (53 g, 58 %) in the
form of a
slightly yellowish solid and 2-methyl-2-(2-propenyloxy)-1-[4-(2-
propenyloxy)phenyl]-1-
propanone (17.6 g; 16 %) in the form of an oil.
A4a: 2-Hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-propanone:
U.V. (CH3CN) max. at 273 nm (e 16 482). IR (KBr film, cm-'): 3452 (OH); 1663
(CO). 'H-
NMR (CDCI3) [ppm]: 8.02 (m, 2 H arom.); 6.92 (m, 2 H arom.); 6.01 (m, 1 H,
allyl); 5.37 (m,
2 H, allyl); 4.60 (m, 2 H, CH2-O); 4.28 (s, OH); 1.62 (s, 6 H, 2 CH3). '3C-NMR
(CDCI3) [ppm]:
162.5 (Carom-); 132.5 (CH allyl); 132.4 Carom.); 118.3 (CH2 allyl); 114.4
Carom.); 75.8
(C(CH3)20H); 69.0 (CH2-O-Ph); 28.8 (CH3). Microanalysis: calc.: C 70.89; H
7.32; found:
C 70.86; H 7.42
CA 02314668 2000-07-27
-46-
A4b: 2-Methyl-2-(2-propenyloxy)-1-[4-(2-propenyloxy)phenyl]-1-propanone
U.V. (CH3CN) max. at 275 nm (e 16 467). 'H-NMR (CDC13) [ppm]: 8.30 (m, 2 H
arom.); 6.92
(m, 2 H arom.); 6.05 (m, 1 H, allyl); 5.80 (m, 1 H, allyl); 5.45-5.08 (m, 4 H,
allyl); 4.60 (m, 2 H,
CH2-O); 3.82 (m, 2 H, CH2-O); 1.54 (s, 6 H, 2 CH3).
C CI C
Example B: Preparation of a catalyst ~ \ ~C' Pt C
CI
A mixture of 20 ml of freshly distilled styrene and 1 g of platinum(II)
chloride is stirred at room
temperature for 40 hours. The orange-coloured suspension is filtered and the
resulting solid
is washed with toluene and hexane.
'H-NMR (DMSO-ds) : 7.35 (m, 5 H arom.); 6.72 (dd, J = 10.9, J = 17.6, 1 H, Ph-
CH); 5.81 (d,
J = 17.6, 1 H); 5.25 (d, J = 10.8, 1 H). Microanalysis: calc: C 40.52; H 3.40;
found: C 40.45;
H 3.03.
CH3
H3C-Si-CH3
0 _ ~ CH3
Example 1: H3C-Si--{CH2)3 O ~ ~ C-C-OH
O CH3
H3C-Si-CH3
CH3
(n = 1, m = p = 0, x = 1, R, ~ R5~ Rs, R~, Rs, Rs~ R,o, R~s~ R,a = CH3, Y = -
(CH2)s-O-~ x = OH)
A mixture of one equivalent of 2-hydroxy-2-methyl-1-(4-(2-propenyloxy)phenyl]-
1-propanone
and one equivalent of 1,1,1,3,5,5,5-heptamethyltrisiloxane in toluene is
heated at 90°C for 18
hours in the presence of 0.012 equivalent (120 ppm, based on the Pt content)
of a Pt catalyst
supported by aluminium oxide. The mixture is then filtered and the resulting
solution is
treated with activated carbon. Filtration and removal of the solvent by
evaporation yield the
compound quantitatively in the form of an oil.
U.V. (CH3CN) max. at 274 nm (E 16 299). ~ H-NMR (CDCI3) b [ppm]: 8.02 (m, 2 H,
ArH); 6.94
(m, 2 H, ArH); 4.30 (s, OH); 3.99 (m, 2 H, Ph-OCHZ); 1.83 (m, 2 H, Ph-OCH2-
CHz); 1.59 (s, 6
H, 2 CH3); 0.58 (m, 2 H, CHZ-Si); 0.05 (s, 21 H, 7 Si-CH3). m/z (EI) 427 (M+-
15); according
to the mass spectrum, small amounts of further compounds are also present: 647
(M+-15);
605 (M+-15); 385 (M+-15); 220 {M+); 180 (M+).
Title product M = 442
CA 02314668 2000-07-27
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CH3 i Hs
CH3 H3C-Si-CH3 CH3 H3C-Si-CH3
H3C-O -CH3 O CH3 Ip H3C-Si-CH3 p CH O
~I I I ~ ~I) I 3 I
H3C-Si-(CHZ)3 O ~ ~ C-C-O-Si-CH3 ~ H3C-O -O ~ / C-CH O-Si-CH3
s M = 662 CH3 O H3C-Si-CH3 3 O
H C Si-CH H3C=Si-CH3 CH M = 620 HsC-Si-CH3
CH3 CH3 3 CH3
CH3
H C-Si-CH
O CHa O GHa
CH3 _ _
H3C-Si-O ~ ~ C-C-OH , HZC=H-H-O ~ / C-C-OH ~ HO ~ / C-C-OH
4 CH3 2 CHs M = 180 CH3
H3C-Si-CH3 M = 400 M = 220
CH3
A sample is purified by flash chromatography and a product of M = 442 and 85 %
purity
(determined by gas chromatography) is obtained. Impurity remains as a result
of the
product of M = 400.
U.V. (CH3CN) max. at 274 nm (s 16 761 ).
CH3 CH3
H3C-Si-CH3 H3C-Si-CH3
O O CH3 O
Example 2: H3C-Si-(CH2)3 O ~ ~ C-C-O-(CH2)3 Si-CH3
O CH3 O
H3C-Si-CH3 H3C-Si-CH3
CH3 CH3
(x = 2; n = 1; m, p = 0; R,, Rs, Rs, R~, t'~s, Rs, Rio, Ris, R,4 = CH3; Y, X~
_ -(CH2)a-O-)
The compound of Example 2 is prepared according to the method described in
Example 1,
using 1 molar equivalent of 2-methyl-2-(2-propenyloxy)-1-[4-(2-
propenyloxy)phenyl]-1-
propanone and 2 molar equivalents of 1,1,1,3,5,5,5-heptamethyltrisiloxane.
U.V. (CH3CN) max. at 275 nm (E 14 666). 1 H-NMR (CDCI3) 8 [ppm]: 8.30 (m, 2 H,
arom.);
6.87 (m, 2 H, arom.); 3.98 (m, 2 H, Ph-OCHZ); 3.23 (m, 2 H, Ph-C(O)-C(CH3)2-
OCH ); 1.80
(m, 2 H, Ph-OCH2-Cue); 1.54 (m, 2 H, Ph-C(O)-C(CH3)2-O-CH2-CHz); 1.50 (s, 6 H,
2 CH3);
0.60 (m, 2 H, CH2-Si); 0.34 (m, 2 H, CHz-Si); 0.10 (m, 42 H, 14 Si-CH3). mlz
(CI) : 705 {MH+);
according to the mass spectrum, small amounts of further compounds are also
present: 663
(MH+); 621 (MH+); 443 (MH+); 401 (MH+); 459 (MH+); 265 (MH+); 239 (MH+).
CA 02314668 2000-07-27
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M = 662, M = 620, M = 442, M = 400 cf. the structures shown in Example 1. The
values MH+
= 459, 265 and 239 are to be assigned to different siloxane chains.
CH3 CH3 CH3 ~ ~ ~ Hs
Example 3: H C-Si-O-Si-O-Si-(CH ) O ~ ~ C-C-OH
3 CH3 CH3 CH3 z 3 CH
3
(x, n, p = 1; m = 0~ R,, A,, Rs, R4, Rs, Rs, Rio, R,3, R,4 = CH3; Y = -(CH2)s-
O-~ X = OH)
The compound of Example 3 is obtained according to the method described in
Example 1,
reacting 1 molar equivalent of 2-hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-
1-propanone
and 1 molar equivalent of 1,1,3,3,5,5,5-heptamethyltrisiloxane.
U.V. (CH3CN) max. at 274 nm (E 24 989). 'H-NMR (CDCI3) 8 [ppm]: 7.94 (m, 2 H
atom.);
6.81 (m, 2 H atom.); 4.34 (OH); 3.91 (m, 2 H, Ph-OCH2); 1.80 (m, 2 H, Ph-OCH2-
CHz); 1.55
(s, 6 H, 2 CH3); 0.57 (m, 2 H, CH2-Si); 0.01 (m, 21 H, 7 Si-CH3). m/z (EI) (%
ratio determined
' by GC-MS): 663 (MH+)(18 %); 443 (MH+)(57 %); 441 (MH+)(3 %); 401 (MH+)(3 %);
221 (MH+)(8); 181 (MH+)(8 %).
Title product M = 442
CH CH CH _ O CH3 CH3 CH3 CH3
3 ~ 3 ~ 3 ~~ i ~ I
H3C-Si-O-Si-O-Si-(CH2)3 O ~ ~ C-C-O-$i-O-Si-O-Si-CH3
CH3 CH3 CH3 CHs ICH3 CH3 CH3
M = 662
O CH3 CH3 CH3 CH3
H2C H H2 O ~ ~ C) CH O $i O Si-O- ~ i-CH3 ,
M = 440 3 'CH3 CH3 CH3
CH3 CH3 CH3 ~ ~ i H3
H3c-~Si-o-si-o-si-o ~ / c-c-off , M = 220 and M = 180 cf. Example 1.
CH3 CH3 CH3 CH
M = 400
A sample is purified by flash chromatography and the pure product of M = 442
is isolated.
U.V. (CH3CN) max. at 274 nm (e 27 180).
CA 02314668 2000-07-27
-49-
CH3
H3C-Si-CH3 _ O CH
3
~ /(CH2)3 O ~ ~ C-C-OH
H3C-Si CH
Example 4: 0
H3C-Si - O CH3
O \ (CH2)3 O ~ ~ C-C-OH
H3C-Si-CH3 CH3
CH3
(n = 2~ x = 1 ~ m, p = 0; R,, Rs, Rs, R~, Ra, Rs, R,o, R,s, R,a = CH3; Y = -
(CH2)s-O-; X = OH)
A mixture of 2 molar equivalents of 2-hydroxy-2-methyl-1-[4-(2-
propenyloxy)phenyl]-1-
propanone and 1 molar equivalent of 1,1,1,3,5,7,7,7-octamethyltetrasiloxane in
50 ml of tolu-
ene is heated for 18 hours at 60°C in the presence of 0.01 equivalent
of a styrene/platinum
dichloride complex (prepared as described in Example B). A further 0.1
equivalent of the
catalyst is added, and the mixture is heated again for 22 hours. Filtration is
then carried out
over diatomaceous earth ("Celite"). Removal of the solvent by evaporation
yields a brown
t oil, which is taken up in ethyl acetate and treated with activated carbon.
Filtration and re-
moval of the solvent by evaporation yield the desired product in a
quantitative yield in the
form of a yellow oil.
U.V. (CH3CN) max. at 274 (E 22 657). 'H-NMR (CDC13) 8 [ppm]: 7.91 (m, 4 H
arom.); 6.83
(m, 4 H arom.); 4.21-3.85 (m, 4 H, 2 Ph-OCH2); 1.76 (m, 4 H, 2 Ph-OCH2-CHz);
1.52 (br. s,
12 H, 4 CH3); 0.95 (m, 2 H, CH2-Si); 0.55 (m, 2 H, CH2-Si); 0.01 (m, 24 H, 8
Si-CH3). mlz (EI)
707 (M+-15); 221 (MH+). Title product: M = 722; M = 220 cf. Example 1.
_ O CH3
H3C-SH3 (CHZ)3 O ~ ~ C-C-OH
O CHs
Example 5: H3C-Si-CH3
O _ O CH3
H3C-Si-(CH2)3 O ~ ~ C-C-OH
CH3 CH3
(n = 2; p, x = 1; m = 0; R~, Rs, Rc, A,, A2, R,s, R,4 = CH3; Y = -(CH2)s-O-; X
= OH)
The compound of Example 5 is obtained according to the method described in
Example 1,
using 2 molar equivalents of 2-hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-
propanone
and 1 molar equivalent of 1,1,3,3,5,5-hexamethyltrisiloxane.
U.V. (CH3CN) max. at 274 (e 25 286). 'H-NMR (CDC13), 8 [ppm]: 7.97 (m, 4 H
arom.); 6.78
(m, 4 H arom.); 4.20 (OH), 3.95 (m, 4 H, 2 Ph-OCH2); 1.73 (m, 4 H, Ph-OCH2-CH
); 1.49 (s,
CA 02314668 2000-07-27
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12 H, 4 CH3); 0.48 (m, 4 H, 2 CH2-Si); 0.01 (m, 18 H, 6 Si-CH3). m/z (CI) :
631 (M+-18); 613
(M+-(2 x 18)); 221 (MH+).
H3C _ O CH3
/(CH2)3 O ~ ~ C-C-OH
Example 6: H3~-Si CH3
0
H3C-Si _ O CH3
H3~ ~(CH2)3 O ~ ~ C-C-OH
CH3
(n = 2; x = 1; m, p = 0; R,, A,, A2, R,3, R,4 = CH3; Y = -(CH2)3-O-; X = OH)
The compound of Example 6 is prepared according to the method described in
Example 1,
using 2 molar equivalents of 2-hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-
propanone
and 1 molar equivalent of 1,1,3,3-tetramethyldisiloxane. According to the'H-
NMR spectrum,
approximately 50% of the 2-hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-
propanone
(starting material, "sm") remain unreacted.
U.V. (CH3CN) max. at 274 (s 32 443). 'H-NMR (CDCI3) 8 [ppm]: 8.19 (m, 2 H
arom. sm);
7.97 (m, 4 H arom.); 6.78 (m, 4 H arom.); 5.99 (m, 1 H allyl sm); 5.31 (m; 2 H
allyl sm); 4.41
(m, 2 H allyl sm); 4.20 (br. s, OH); 3.95 (m, 4 H, 2 Ph-OCH2); 1.80 (m, 4 H, 2
Ph-OCH2-CHz);
1.56 (s, 12 H, 4 CH3); 0.56 (m, 4 H, 2 CH2-Si); 0.01 (m, 12 H, 4 Si-CH3). m/z
(CI) : 707 (MH+);
575 (MH+); 533 (MH+); 491 (MH+); 221 (MH+); 181 (MH+). Title product: M = 574
H3C _ O CH CH CH
II I 3 I 3 ~ 3 _ O ~rHg
/(CHz)3 O ~ ~ C-C-O-Si-O-Si-H H3 ~ ~O ~ ~ C-C-OH
H3C-O CH3 CH3 CH3 H3C-O CH3
I
H3C-Si _ O CH3 H3C-Si _ O CH3
H3C ~(CHZ)3 O ~ ~ C-C-OH H C ~(CHZ)3 O ~ ~ C-C-OH
M = 7O6 CH3 M = 532 CH3
_ O CH3
H3 ~ /O ~ ~ C-C-OH
H3C-Si CH3
o , M = 220 and M = 180 cf. Example 1.
I
H3C-Si _ O CH3
H3C ~ O ~ ~ C-C-OH
CH3
M = 490
CA 02314668 2000-07-27
-51 -
3 O
HO-CH CI ~ ~ O
CH3 ICH2)s
HsC_ ~ i-Ow CHs O ~ H3
Example 7: CH3 O~ S~-(CH2r0 ~ ~ C-C-OH
HO-C-C ~ ~ O-(CHZ)3-Si~O-Si-OCH CH3
H3C O CH3 ~ 3 ~ CH3
(CH2)3 O ~ ~ C-C-OH
CH3
(n = 4; x = 1; m, p = 0; A~+A2 = single bond; R,, R,3, R~4 = CH3; Y = -(CHZ)3-
O-; X = OH)
The compound of Example 7 is prepared according to the method described in
Example 1,
using 4 molar equivalents of 2-hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-
propanone
and 1 molar equivalent of 2,4,6,8-tetramethylcyclotetrasiloxane. According to
the 'H-NMR
spectrum, after the reaction the mixture still contains approximately 36 % 2-
hydroxy-2-
methyl-1-[4-(2-propenyloxy)phenyl]-1-propanone (starting material, "sm").
U.V. (CH3CN) max. at 274 (~ 58 856). 'H-NMR (CDCI3) 8 [ppm]: 7.90 (m, 8 H
atom.); 6.77
(m, 8 H atom.); 5.9 (m, 1 H allyl sm); 5.25 (m, 2 H allyl sm); 4.41 (m, 2 H
allyl sm); 4.10 (m,
OH); 3.90 (m, 8 H, 4 Ph-OCH2); 1.71 (m, 8 H, 4 Ph-OCH2-CHz); 1.47 (s, 24 H, 8
CH3); 0.54
(m, 8 H, 4 CH2-Si); 0.01 (m, 12 H, 4 Si-CH3). '3C-NMR (CDC13) 8 [ppm]: 202.5
(CO); 162.9,
162.5, 160.8 (Carom-O)~ 132.3-114.0 (atom.); 75.9 (C(CH3)20H); 70.2 (CH2-O-
Ph); 28.6 (CH3);
22.7 (CH2-CH2-O-Ph); 13.0 (CH2-Si); -0.7 (CH3-Si); m/z (CI): 1121 (MH+); 943
(MH+); 901
(MH+); m/z 221 (MH+);
Title product: M = 1120
R~
I
H C-Si-O CH3 _ O CH3
43~~ S~-R2 ; R'=R2=R3= -(CH2)3 ~ ~ ~ C-C-OH ~ R4 = H; M = 900
R-Sip ~O CH3
O-Si-CH3
CH3 R3
CA 02314668 2000-07-27
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0
HO-CH3CI / \ O
CH3 ICHz)s
H3C-Si-O~ CH3
CH p Si-(CH2)2CH3
HO-,C 3C ~ ~ O-(CHZ)3-SiwO-Si OCH
H3C O CH3 ~ 3 - ~ CH3
M = 942 (CH2)3 O ~ ~ C-C-OH
CH3
HO- ~(CHZ)3O ~ / O- ~HOH
H31C
O-(CH
)
i -Si
~ /
Z
3
O
~ p CH
Example 8: CH3 H CH 3
C''S~ 1
CH
3 / p
3 _ CH
O 3 3
II\(CH
)
~ H3 ~l H' O 3 O ~ ~ C
i~-C z ~
~ -OH
O ~ i"_CH3O CH CH3
HO- i -C ~ / O'_-(CHz)3
3
CH3 (CHZ)3~~~ ~~ ~ _..
CH3
(n = 5; x = 1; m, p = 0; A~+A2= single bond; R~, R,3, R~4 = CH3; Y = -(CH2)3-O-
; X = OH)
The compound of Example 8 is obtained according to the method described in
Example 1,
using 5 molar equivalents of 2-hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-
propanone
and 1 molar equivalent of 2,4,6,8,10-pentamethylcyclopentasiloxane.
U.V. (CH3CN) max. at 275 (s 61 882). 'H-NMR (CDCIg) 8 [ppm]: 7.87 (m, 10 H
arom.); 6.72
(m; 10 H arom.); 4.10 (m, OH); 3.7 (m, 10 H, 5 Ph-OCH2); 1.7-0.8 (m, 40 H, 5
Ph-OCH2-CHz
and 10 CH3); 0.5 (m, 10 H, 5 CH2-Si); 0.01 (m, 15 H, 5 Si-CH3). m/z (CI) :
1401 (MH+); 1181
(MH+); 960 (MH+); 221 (MH+).
Title compound M = 1400
R'
2
~Si ~~R _ O CH
R~~i .o~Si.O R~ = R2 = R3 = R4 = -(CH2)3 0 \ / C-C-off , Rs = H, M = 1180;
CH
/SI~O SI~Ois3W
R 4~ R
_ O CH3
R' = R2 = R3 = -(cH2)3 0 ~ ~ c-c-off , R4 = R5 = H, M = 960; M = 220, cf.
Example 1.
CH3
CA 02314668 2000-07-27
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CH3 i H3 i H3 CH3 i H3 O CH3
Example 9: H3C- i i-O Si-O i i-O i i-O i i-CH3 IN = -(CH2)3 O ~ / C-C-OH
CH3 IN LH LCH3 CH3 CH3
n m P
(n = 0.8; m - 0.4; p = 23.75; x = 1; R,, R2, R3, Ra, R5, Rs, R~, R8, Rs, Rlo,
R,s, R,a = CHs;
Y = -(CH2)3-O-; X = OH)
The compound of Example 9 is obtained according to the method described in
Example 1,
using 29 molar equivalents of 2-hydroxy-2-methyl-1-[4-(2-propenyloxy)phenyl]-1-
propanone
and 1 molar equivalent of methylhydrosiloxane / dimethylsiloxane copolymer
having
6-7 mol % methylhydrosiloxane groups and a molecular weight of from 1900 to
2000
(HMS 071, Gelest, DE).
According to the'H-NMR spectrum, the product still contains approximately 33 %
2-hydroxy-
2-methyl-1-[4-(2-propenyloxy)phenyl]-1-propanone (starting material "sm"). The
'H-NMR
spectrum also shows that the content of methylhydrosiloxane groups is 5 %, of
which 67
' have been substituted by a photoinitiator group (IN), that is to say n =
0.83, m = 0.41, p =
23.75.
'H-NMR (CDCI3) 8 [ppm]: 7.94 (m, H arom.); 6.85 (m, H arom.); 5.95 (m, H allyl
sm); 5.28
(m, H allyl sm); 4.52 (m, H allyl sm); 4.24 (m, OH); 3.90 (m, Ph-OCH2); 1.76
(m, Ph-OCH2-
CHz); 1.55 (s, CH3); 0.56 (m, CH2-Si); 0.01 (m, Si-CH3). '3C-NMR (CDC13) : 202
(CO); 163
(Carom'); 132.3-114.0 Carom.); 70.5 (C(CH3)20H); 68.9 (CH2-O-Ph); 28.7 (CH3);
22.8 (CH2-
CH2-O-Ph); 13.3 (CH2-Si); 1.1, 1.0, 0.8 (CH3-Si).
i H3 CHs i Ha CHa i H3 _ O CH
Example 10: H3c-si-o si-o i i-o i i-o si-cH3 IN = -(cH2)3 0 ~ / c-c-off
CH3 IN LH LCH3 CH3 CH3
n m P
The compound of Example 10 is prepared analogously to the method described in
Exam-
ple 1, using 1 molar equivalent (based on the Si-H groups) of 2-hydroxy-2-
methyl-1-[4-(2-
propenyloxy)phenyl]-1-propanone and 1 molar equivalent of methylhydrosiloxane
I dimethyl-
siloxane copolymer with 1.78 mmollg(resin) of methylhydrosiloxane groups (VXL
Fluid,
Witco).
'H-NMR (CDCI3) 8 [ppm]: 7.95 (m, H arom.); 6.8 (m, H arom.); 4.25 (m, OH); 3.9
(m, Ph-
OCH2); 1.75 (m, Ph-OCH2-Cue); 1.5 (s, CH3); 0.55 (m, CH2-Si); 0.01 (m, Si-
CH3).
CA 02314668 2000-07-27
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I H3 CH3 ~ H3 ~ H3 CHs
~O CH3
Example 11: H3c-si-o si-o i i-o i ~-o si-cH3 IN = -(cH2>3 0 ~ / c-c-off
CH3 IN LH LCH3 CH3 CH3
n m P
The compound of Example 11 is prepared according to the method described in
Example 1,
using 1 molar equivalent (based on the Si-H groups) of 2-hydroxy-2-methyl-1-[4-
(2-propenyl-
oxy)phenyl]-1-propanone and 1 molar equivalent of
methylhydrosiloxane/dimethylsiloxane
copolymer with 7.05 mmol/g(resin) of methylhydrosiloxane groups (Y 12183,
Witco).
'H-NMR (CDCI3) 8 [ppm]: 7.9 (m, H arom.); 6.75 (m, H arom.); 4.15 (m, OH);
3.85 (m, Ph-
OCH2); 1.75 (m, Ph-OCH2-CHz); 1.45 (br. s, CH3); 0.55 (m, CH2-Si); 0.01 (m, Si-
CH3).
i H3 ~ H3 i H3 ~ H3 ~ H3 _ O CH3
Example 12: H3c- ~ i-o s~-o i i-o i i-o si-cH3 IN = --ccH2>3 0 ~ / c-c-off
CH3 IN LH LCH3 CH3 CH3
n m P
The compound of Example 12 is prepared as described in Example 1, using 1
molar equiva-
lent (based on Si-H groups) of 2-hydroxy-2-methyl-1-(4-(2-propenyloxy)phenyl]-
1-propanone
and 1 molar equivalent of methylhydrosiloxane/dimethylsiloxane copolymer with
15.62
mmollg(resin) of methylhydrosiloxane groups (Fluid L31, Witco).
According to the'H-NMR spectrum, the product still contains approximately 33 %
2-hydroxy-
2-methyl-1-[4-(2-propenyloxy)phenyl]-1-propanone ( starting material "sm").
'H-NMR (CDC13) 8 [ppm]: 7.94 (m, H arom.); 6.85 (m, H arom.); 5.95 (m, H ally)
sm); 5.25
(m, H allyl sm); 4.52 (m, H allyl sm); 4.22 (m, OH); 3.90 (m, Ph-OCH2); 1.65
(m, Ph-OCH2-
CH ); 1.55 (s, CH3); 0.6 (m, CH2-Si); 0.01 (m, Si-CH3).
CH3
H3C-Si-CH3
O CH3
C-C-OH
Example 13: H3C-Si-H~(CHZ)2 0 2 ~ ~ CH
2 3
H3C-Si-CH3
CH3
The compound of Example 13 is prepared according to the process described in
Example 1,
using 1 molar equivalent of 1-[4-(2-allyloxy-ethoxy)-phenyl]-2-hydroxy-2-
methyl-propan-1-one
and 1 molar equivalent of 1,1,1,3,5,5,5-heptamethyltrisiloxane.
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U.V. (CH3CN) max. at 273 nm (E 13 811).'H-NMR (CDCI3): 7.96 (m, 2 H, arom.);
6.87 (m,
2 H, arom.); 4.38 (OH); 4.09 (m, 2 H, Ph-OCH2); 3.71 (m, 2 H, Ph-O(CH2)2-O-CH
); 3.40 (m,
2 H, Ph-OCH2C~); 1.53 (m, 2 H, Ph-O(CH2)2-OCH2-CH ); 1.53 (s, 6 H, 2 CH3);
0.38 (m, 2 H,
CH2-Si); 0.01 (m, 21 H, 7 Si-CH3). mlz (EI and CI) : 486 (M+); according to
the MS spectrum,
small amounts of the following compounds are also present: 486 (M+) (second
signal); 442
(M+); 264 (M+)(2 signals); 246 (M+); 238 (M+). The values M = 264 (second
signal) and 238
are assigned to different siloxane chains.
CHs CHs
HsC~Si-CHs HsC-Si-CHs
_ O CHs O O H
HZC=C-C-O-C-C-O ~ / C-C-O-Si-CHs H3C-Si-O-C-C? _ O CHs
H Hz Hz Hz CHs O ~ Hz O ~ / C-C-OH
i
M = 486 HsC,Si-CHs HsC-Sip CHs
(second signal) CHs CH3CHs M = 442
/~_ O CHs _ O CHz
H C=C-C-O-C-C-O-( C-C-OH H C=C-C-O-C-C-O~C-C
z H Hz Hz Hz ~~/ CH z H Hz Hz Hz ~ / CHs
3
M=264 M=246
CHs CHs
H3C-Si-CHs H3C-Si-CHs
i
O _ O CHs O
i
Example 14: H3C-Si-H-~(CHz)z-O 2 ~ / C-C-O-(CHz)3 Si-CH3
p z CHs O
H C-Si-CH
H3Cr-SI-CH3 3 ~ 3
CH3 CHs
The compound of Example 14 is prepared as described in Example 1, using 1
molar equiva-
lent of 2-allyloxy-1-[4-(2-allyloxy-ethoxy)-phenyl]-2-methyl-propan-1-one and
2 molar
equivalents of 1,1,1,3,5,5,5-heptamethyltrisiloxane.
U.V. (CH3CN) max. at 276 nm (E 11 693). 'H-NMR (CDCI3): 8.24 (m, 2 H, arom.);
5.94 (m,
2 H, arom.); 4.09 (m, 2 H, Ph-OCH2); 3.71 (m, 2 H, Ph-O(CH2)2-O-CH ); 3.40 (m,
2 H, Ph-
OCH2C~); 3.13 (m, 2 H, C(CH3)2-OCHz); 1.54 (m, 4 H, Ph-O(CH2)2-OCH2-CH and
C(CH3)2-
OCH2-CH ); 1.42 (s, 6 H, 2 CH3); 0.38 (m, 4 H, 2 CH2-Si); 0.01 (m, 42 H, 14 Si-
CH3). m/z (EI
and CI) : 748 (M+); according to the MS spectrum, small amounts of compounds
of 528 (M+);
and 486 (M+) are also present.
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CH3 CH3
H3C-Si-CH3 H3C-Si-CH3
_ O O CH
H3C-O-(CH2)3-O-(CHz)2-O ~ ~ OC CHOC3H~ H3C-Si-(CHZ)3 O-(CH2)2 O ~ ~ C-C-OH
O CH3 O CH3
H C-Si-CH H3C-Si-CH3 M = 486
3 CH 3 M = 528 CHs
3
CH3
H3C-Si-CH3
_ O CH3~--~
Example 15: H3C-O-(CHZ)3 O ~ ~ C Chi
3
H3C-Si-CH3
CH3
The compound of Example 15 is prepared according to the method described in
Example 1,
using 1 molar equivalent of 1-(4-allyloxy-phenyl)-2-methyl-2-morpholin-4-yl-
propan-1-one and
1 molar equivalent of 1,1,1,3,5,5,5-heptamethyltrisiloxane.
U.V. (CH3CN) max. at 273 nm (E 15 248). 'H-NMR (CDC13): 8.47 (m, 2 H, arom.);
6.79 (m,
2 H, arom.); 4.09 (t, 2 H, Ph-OCH2, J = 6); 3.58 (m, 4 H, N=(CH2-CHz)2=O);
2.46 (m, 4 H,
N=(CH -CH2)2=O); 1.73 (m, 2 H, Ph-O-CH2CH2); 1.21 (s, 6 H, 2 CH3); 0.49 (m, 2
H, CH2-Si);
0.01 (m, 21 H, 7 Si-CH3). m/z (EI and CI) : 512 (MH+); according to the MS
spectrum, small
amounts of compounds 512 (MH+)(second signal); 470 (MH+); and 265 (MH+) are
also pres-
ent. The value MH+ = 265 is assigned to a siloxane chain.
CH3 CH3
H3C-Si-CH3 H3C-Si-CH3
_ O CH ~ _
H3C Oi-H C CH2 O ~ ~ C-C- ~ H3C Oi O ~ ~ OC-C(HN~ O
O CHs V O, CH3
H3C-Si-CH3 H3C-Si-CH3
CH3 M = 512
(second signal) CH3 M = 470
CH3 CH3 _ O CH3 ~
Example 16: H3C-Si-O-Si-(CHZ)3 O ~ ~ C-C- V
CH3 CH3 CH3
The compound of Example 16 is prepared according to the method described in
Example 1,
using 1 molar equivalent of 1-(4-allyloxy-phenyl)-2-methyl-2-morpholin-4-yl-
propan-1-one and
1 molar equivalent of 1,1,3,3,3-pentamethyldisiloxane.
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U.V. (CH3CN) max. at 273 nm (s 14 281). 'H-NMR (CDCI3): 8.51 (m, 2 H, arom.);
6.79 (m,
2 H, arom.); 3.90 (t, 2 H, Ph-OCH2, J = 6); 3.60 (m, 4 H, N=(CH2-CH2)2=O);
2.48 (m, 4 H,
N=(CHz-CH2)2=O); 1.77 (m, 2 H, Ph-O-CH2CH2); 1.23 (s, 6 H, 2 CH3); 0.56 (m, 2
H, CH2-Si);
0.01 (m, 15 H, 5 Si-CH3). m/z (EI and CI) : 438 (MH+) (CI); according to the
MS spectrum,
small amounts of compounds 396 (MH+); and 290 (MH+) are also present.
3 CH _ O CH ~ _ O CH3
H C SH O-Si 3 O C-C-N O H2C H-H-O ~ ~ C-C-N~ O
3 i
CH3 CH3 CH3~ 2 CH3
M = 289
M = 395
CH3
H3C-Si-CH3
p - O CH3
Example 17: H3C-Si-(CH2)3 O-(CHZ)3 ~ ~ C-C-OH
O CHs
H3C-Si'CH3
CH3
The compound of Example 17 is obtained according to the method described in
Example 1,
using 1 molar equivalent of 1-[4-(3-allyloxy-propyl)-phenyl]-2-hydroxy-2-
methyl-propan-1-one
and 1 molar equivalent of 1,1,1,3,5,5,5-heptamethyltrisiloxane.
U.V. (CH3CN) max. at 255 nm (s 13 289). 'H-NMR (CDC13): 7.89 (m, 2 H, arom.);
7.18 (m,
2 H, arom.); 3.30 (m, 4 H, Ph-(CH2)2-CH2-O-CH ); 2.63 (m, 2 H, Ph-CH2); 1.84
(m, 2 H, Ph-
(CH2)3-O-CH2-CHz); 1.54 (s, 6 H, 2 CH3); 1.47 (m, 2 H, Ph-CH2-Cue); 0.38 (m, 2
H, CH2-Si);
0.01 (m, 21 H, 7 Si-CH3). m/z (EI and CI): 484 (M+); according to the mass
spectrum, small
amounts of 484 (M+) (second isomer); 338 (M+); 310 (M+ = 338 - 18); 262 (M+);
244 (M+ _
262 - 18); 222 (M+); and 204 (M+ = 222 - 18) are also present.
Hs
~CH
H3C--SI 3
CH3 O CH ~H - O CH3
H3C O~ H H O (CHZ)3 ~ / C CFiOH H3C-Si-(CH2)3 O-(CH2)3 ~ ~ C C OH
OH CHs
H3C-~Si-CH3 M = 484 M = 338
CH3
_ O CH3 _ O CH
HZC=C-C-O-(CHZ)3 ~ ~ C-C-OH HO-(CH2)3 ~ ~ C-'C-OH
H H2 CH3 CH3
M = 262 M = 222
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CH3 CH3
H3C-Si-CH3 H3C-Si-CHs
p - O CH3 O
Example 18: H3C-Si-(CH2)3 O-(CH2)3 ~ ~ C C O (CH2)3 Si-CH3
O CHs O
H3C-$i'CHs H3C-Si-CH3
i
CH3 CH3
The compound of Example 18 is prepared according to the method described in
Example 1,
using 1 molar equivalent of 2-allyloxy-1-[4-(3-allyloxy-propyl)-phenyl]-2-
methyl-propan-1-one
and 2 molar equivalents of 1,1,1,3,5,5,5-heptamethyltrisiloxane.
U.V. (CH3CN) max. at 256 nm (~ 9542).'H-NMR (CDC13): 8.14 (m, 2 H, arom.);
7.19 (m, 2 H,
arom.); 3.30 (m, 4 H, Ph-(CH2)2-CH -O-CH2); 3.14 (m, 2 H, C(CH3)2-OCHz); 2.65
(m, 2 H, Ph-
CH2); 1.82 (m, 2 H, Ph-(CH2)3-O-CH2-CH2); 1.48 (m, 2 H, C(CH3)2-OCH2-CH );
1.42 (s, 6 H, 2
CH3); 1.15 (m, 2H, Ph-CH2-CH ); 0.38 (m, 4 H, 2 CH2-Si); 0.01 (m, 42 H, 14 Si-
CH3). m/z (EI
and CI) : 746 (M+); according to the MS spectrum, small amounts of compounds
484 (M+);
and 238 (M+) are also present. The value M = 238 is assigned to a siloxane
chain.
CH3
H3C-Si-CH3
p _ p CH3
H3C-Si-(CH2)3 O-(CHZ)3 ~ ~ C-C-OH
O CHs
HsC_Si.CHs
CH3 M = 484
CH3
H3C-Si-CH3
p _ O CH3
Example 19: H3C-Si-(CHZ)3 O-(CH2)3 ~ ~ C-C-N O
CH3 U
HsC_$i.CHs
CH3
The compound of Example 19 is prepared according to the method described in
Example 1,
using 1 molar equivalent of 1-[4-(3-allyloxy-propyl)-phenyl]-2-methyl-2-
morpholin-4-yl-propan-
1-one and 1 molar equivalent of 1,1,1,3,5,5,5-heptamethyltrisiloxane.
U.V. (CH3CN) max. at 253 nm (s 14 930). 'H-NMR (CDCI3): 8.38 (m, 2 H, arom.);
7.14 (m,
2 H, arom.); 3.60 (m, 4 H, N=(CH2-CHz)2=O); 3.30 (m, 4 H, Ph-(CH2)2-CH -O-
CHI); 2.65 (t,
2 H, J = 6, Ph-CH2); 2.48 (m, 2 H, N=(CHz-CH2)2=O ); 1.83 (m, 2 H, Ph-CH2CHz);
1.51 (m,
2 H, Ph-(CH2)3-O-CH2-Cue); 1.21 (s, 6 H, 2 CH3); 0.38 (m, 2 H, CHZ-Si); 0.01
(m, 21 H, 7 Si-
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CH3). m/z (EI and CI) : 553 (M+); according to the mass spectrum, small
amounts of the
compounds of 333 (M+); 331 (M+); and 238 (M+) are also still present. The
value M = 238 is
assigned to a siloxane chain.
_ O CH3 ~ _ O CH3 ~--~
H~C3 O (CHZ)3 \ / C CHN~ HZC H H O (CHz)3 \ / C CH
3
M=333 M=331
CH3
H3C-Si-CH3
Examele 20: H3C OS~ i-(CH2)3 O-(CH2)Z O ~ / CO~
O HO
i
H3C-Si-CH3
CH3
The compound of Example 20 is obtained according to the method described in
Example 1,
using 1 molar equivalent of [4-(2-allyloxy-ethoxy)-phenyl]-(1-hydroxy-
cyclohexyl)-methanone
and 1 molar equivalent of 1,1,1,3,5,5,5-heptamethyltrisiloxane.
U.V. (CH3CN) max. at 274 nm (>r 11 211). 'H-NMR (CDC13): 8.01 (m, 2 H, arom.);
6.87 (m,
2 H, arom.); 4.07 (m, 2 H, Ph-OCH2); 3.71 (m, 2 H, Ph-O(CH2)2-O-CH ); 3.40 (m,
2 H, Ph-
OCH2CH2); 1.95 (m, 2 H, Ph-O-(CH2)2-OCH2-CH2); 1.68-1.20 {m, 11 H, -C6H»);
0.38 (m, 2 H,
CHZ-Si); 0.01 (m, 21 H, 7 Si-CH3). m/z (EI and CI) : 526 (M+); according to
the mass spec-
trum, small amounts of the compounds 304 (M+)(2 signals); 264 (M+) and 238
(M+) are also
present. The values M = 264 and 238 are assigned to siloxane chains.
_ o
/~ ~ z)z
HZC=C-C-O-(CH2)2 O ~ / C~ HO CH -O \ /
H HZ HO~ ~ .,O
M = 304 M = 304 HzC-H~H2
Example 21: Curing of a UV-curable clear lacquer
A UV-curable clear lacquer is prepared by mixing the following components:
50.0 parts of a difunctional urethane acrylate (RT""Actylan 200, Akcros)
25.0 parts tripropylene glycol diacrylate (SR 306, Cray Valley)
15.0 parts trimethylolpropane triacrylate (UCB)
10.0 parts dipentaerythritol pentaacrylate (SR 399, Cray Valley)
2 % of the photoinitiator from Example 1 are added to the mixture. The mixture
is applied to
a white chipboard panel and is cured using a UV processor below two 80 W/cm
lamps at a
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band speed of 3 mlmin. A non-sticky cured film approximately 50 ~m thick is
obtained.
30 minutes after curing, the pendulum hardness according to Konig (DIN 53157)
is deter-
mined in seconds. The higher the value, the greater is the hardness of the
crosslinked sur-
face. The static water contact angle (8) is also determined. For that purpose
there is used a
Kruss G10 contact angle measuring system. In that procedure, after the
formulation has
been cured, a drop of water is applied thereto. The contact angle is
determined from the
equilibrium of forces at the three-phase interface (airlwaterlcoating). A
computer program
matches the profile of the lying drop of water to a general conic section
equation. The differ-
ential of the equation at the base line gives the slope at the three-phase
contact point and
thus the contact angle. The greater the contact angle measured, the better are
the moisture-
resistance and scratch-resistance of the cured surface. (The following
publications give fur-
ther explanation of the determination of contact angles: "Contact Angle,
Wettability, and Ad-
hesion", Advances in Chemistry Series 43, Am. Chem. Soc. 1964; Kruss User
Manual, Drop
Shape Analysis, Kruss GmbH, Hamburg 1997; G. Hirsch "Bestimmung der Oberflach-
enspannung von Festkorpern aus Randwinkelmessungen and ihre Bedeutung bei
Benetzungsproblemen" Chemie-Ing.-Techn 40.Jahrg. 1968, Volume 13, 639-645.)
The pendulum hardness measured is 130 s; the contact angle B is 81
°.
Example 22: Curing of a UVlthermally curable system (Dual Cure)
A "Dual-Cure" clear lacquer is prepared by mixing the following components:
21.1 parts of a hydroxy-functional polyacrylate (RT""Desmophen LS 2009/1,
Bayer AG)
32.3 parts of a urethane acrylate based on isocyanurate in 80 % butyl acetate
(RTnnRoskydal FWO 2518C, Bayer AG)
0.3 part flow improver in 10 % xylene (RT""Baysilone OL 17, Bayer AG)
0.3 part flow improver (Rr""Modaflow, Monsanto)
26.0 parts 1-methoxy-2-propanol (Fluka Chemicals)
0.5 part flow improver (RT""Byk 306, Byk-Chemie)
11.2 parts urethane acrylate containing isocyanate groups (RT""Roskydal FWO
2545 E,
Bayer AG)
To the resulting mixture there are added 2.635 % of the photoinitiator from
Example 1, 0.375
bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (RT""Irgacure 819, Ciba
Specialty
Chemicals), 1.5 % of a mixture of 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-
hydroxy
phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine and 2-[4-[(2-hydroxy-3-
tridecyloxy-propyl)
oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (RT""Tinuvin
400) and 1 % of
CA 02314668 2000-07-27
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a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate and 1-(methyl)-8-
(1,2,2,6,6-
pentamethyl-4-piperidinyl)-sebacate (Rr""Tinuvin 292, Ciba Specialty
Chemicals). The mix-
ture is applied to a white-coated aluminium sheet, air-dried for 5 minutes at
room tempera-
ture and heated on a hotplate for 10 minutes at 80°C. The irradiation
is carried out thereafter
using a UV processor below two 120 W/cm lamps at a band speed of 5 m/min. A
non-sticky
cured film approximately 40 ~m thick is obtained. 45 minutes after curing, the
pendulum
hardness according to Konig (DIN 53157) is determined in seconds. The higher
the value,
the greater is the hardness of the crosslinked surface. The static water
contact angle (8) is
also determined, as described in Example 13, using a Kruss G10 contact angle
measuring
system. The greater the contact angle measured, the better are the moisture-
resistance and
scratch-resistance of the cured surface. The pendulum hardness measured is 85
s; the
contact angle 8 is 92°.
CA 02314668 2000-07-27
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Example 23: Siloxane-containing photoinitiator as flow improver
A formulation is prepared by mixing the following components:
57.0 parts of a hexa-functional aliphatic urethane acrylate (made by UCB)
13.0 parts hexanediol diacrylate (made by UCB)
2 % of the compound from Example 13 are dissolved in the formulation. The
formulation is
then applied using a 100 mm slotted knife to a chipboard panel coated with
white primer and
the contact angle of the coating relative to water is determined (for a
description of contact
angle measurement, see Example 21 ). For that purpose a drop of water of a
specific volume
is applied to the coated surface and the angle 8 of a tangent to the contact
surface of the
drop relative to the surface is measured using a special lens system and a
computer pro-
gram. The greater the contact angle, the better is the flow of the coating on
the substrate in
question (in this case a white chipboard panel), that is to say the lower is
the surface tension.
The contact angle 8 for the present formulation is 51.56°.
