Note: Descriptions are shown in the official language in which they were submitted.
- 213~8 ~'
WO 93J22368 - 1 - PCT/EP93/01113 ~ C~
Siloxane copolymer con~aining ~inyloxy group~,
their preparation and their use
The in~ention ralates to siloxane copolymers
containing ~inyloxy groupa a~d to a process for their
preparation. The in~e~tion further~ore relate~ to com-
position~ which c~ be cro~slinked by light and are based
on siloxane copolymers containi~g ~inyloxy group~.
Organopoly iloxane~ which contain, per molecule,
at least one Si-bonded ~inyloxy-fu~ctional group of the
~ormula
~2C=CH-O-G-
wherein ~ i~ an alkylene radical or an alkylene radical
which is interrupted by at leaat one divalent hetero
radical, ~uch as -O-, a di~alent phe~ylene radical or a
~ubstituted di~alent phenylene radical, or combinations
of ~uch hetero radicals, are know~ from EP-~ 105 341.
These organopolysiloxanes are obtained by preparation of
a compou~d ha~i~g an allyl and a vinyloxy group and
addition of this compound onto the SiH groups of the
organopolysiloxane~, hydrosilylation taking place only on
the allyl group. EP-B 105 341 furthermore describes
composition~ w~ich can be cros~linked by light and
compri~e the abo~ementioned organopoly~iloxanes, and also
onium salt~ which cataly~e the ~ationic polymerisation of
the~e organopolyRiloxanes.
A ~ila~e which has one vinyloxypropyl group and
at least one trimethylsiloxy group and which is obtained
by hydrosilylation of allyl ~inyl ether with a silane
containing trimethylsiloxy groups, addition taking place
on the allyl group, i8 known for the production o~
pla~tic lenses from Chemical Abstracts 107, 176221q.
Orga~opoly~iloxanes which contain propenyloxy
groups and siloxane copolymers which contain propenyloxy
groupR are deRcribed in US-A 5,057,549 and C~-A
20 35 396, these compou~ds being prepared in a two-stage
process by addition of compounds ha~ing two or more than
- ~13~7~''
-- 2
two allyloxy group~ onto si~ groups of organopolysilox-
anes and ~ub~equent conversion o~ the allyloxy groups
into the propenyloxy groups by addition o~ the double
¦bond.
Organopolysiloxanes which have any number of
substituted vinyl ether groups and are prepared by
hydrosilylation, that is to say by reaction of an organo-
polysiloxane containing SiH group~ with a polyoxyalkylene
ether, for example of the for~ula
C-~2--c~i--cx2--o--(C~iz_c:w-O--) loH r
C~2
C'~i '
C~
addition taking place on the allyl group, are known from
US-A 5,145,915.
There was the obj,ect of providing siloxane
copolymer~ which contain ~inyloxy groups and can be
prepared in a simple process, the process allowing more
than one ~inyloxy group to be introduced on one Rilicon
atom. There was furthermore the object of pro~iding
~iloxane copolymers which contain ~inyloxy group~ and
crosslink particularly rapidly under the action of light,
in particular ultraviolet light, with cationic
polymerisation. This object is achieved by the in~ention.
The invention relates to siloxane copolymers
which contain vinyloxy groups and comprise
(a) siloxane units of the formula
. ~asi(OR )b4-(a~b) (I)
wherein R denote~ identical or di~ferent, optionally
halogenated hydrocarbon radicals having 1 to 18
21~317~Q
- 3
carbon ato~( 8 ) per radical,
Rl denotes identical or differe~t alkyl radicals
having 1 ko 4 carbon atom(~ per radical, which ca~
be subGtituted by a~ ether oxygen atom,
a iB 0, 1, 2 or 3,
b i~ 0, 1, 2 or 3
a~d the ~um of a+b i8 not greater than 3,
(b) at least one unit per molecule chose~ from the group
co~pri~ing U~i tB 0 f the for~ula
~ 4-(c'l) (II)
04 (c+l)RcSi-G -SiRco4_(c~l) (III)
0 2
4-(cll~Rcsi-G -SiRco4 ( (IV) and
2 liRc4_(c+l)
: , 2 --
S iRc4 ( c ' 1 )
O R Si l~ SiR o 2
SiRc4-(cll) (V)
wherein R has the meaning gi~en above for thi~
radical,
c i~ 0, 1 or 2,
G denotes a radical of the formula
- CH2CH20Y (OCH=C}I2) X-l
wherein
`-- 213Li7G~
-- 4
Y denotes a divalent, trivalent, tetravalent,
pentavalent or hexavalent hydrocarbon radical having
1 to 20 carbon atoms per radical,
which can be #ub~tituted by groups of the for~ula
- 0~ .
2 (wherein R2 denotes an alkyl radical
having 1 to 6 carbon atom(s) per
radical)
- osiR3 (wherein R3 denotes a methyl, ethyl,
isopropyl, tert-butyl or phenyi radical)
- OCR2 (wherein R2 has the meaning given above
11
0 for this radical) or
- X (wherein X denotes a halogen atom)
-15 or can be interrupted by at least one oxygen
atom, one carboxyl or one car~onyl group, and
x is 2, 3, 4, 5 or 6,
G1 denotes a radical of the formula
( C~I=CH2 ) X-Z
-Cx2cH20-~-ocH2c~2
~2 denoteq a radical of the ~ormula
~ (OCH=CX2)x-3
; ~ 20 -CH2C~2~-Y-0C~2c~2 and
lCX2C~2-
':~
:
G3 denotes a radical of the formula
: (Cx=c~2)x-4
-CY.2 C~20~Y-~cx2 CX2
. (~C~C~2-)2
: wherein Y and x have the meaning given above for
these eymbols~
The siloxane copolymers containing vinyloxy
~'~i.
21~ ~7~
-- 5
groups preferably compri~e Riloxane unit3 of the formula
(I), at least one siloxa~e unit of the formula (II~ per
molecule and at least o~e unit 3elected from the group
comprising the unit~ of the formulae (III), tIV) and (V)
per molecule.
The in~ention furthermora relate~ to a proces
for the preparation of the siloxa~e copolymers containing
vinyloxy groups, characterised i~ that an organic com-
pound (l) containing more than one vi~yloxy group, of the
general formula
y (oc~I=c~2) x (1)
_ where Y and x have the meaning giYen above for these
~ymbol~ i~ reacted with a~ organopolysiloxane (2) ha~ing
at lea~t ona Si-bonded hydroge~ atom per molecule, in the
presence of a cataly~t (3) which promoten the addition of
Si-bonded ~ydrogen onto an aliphatic double bond, the
ratio employed of aliphatic double bond in the organic
compound (1) to Si-bonded hydrogen in tha-organopoly-
siloxane (2) i~ ch that siloxane copolymer~ containing
~inyloxy group~, having on a~erage at least one vinyloxy
group of the formula
-OC~=CH~
are obtained.
In the prior art, as in the abo~ementioned EP-B
105 341, neither ar~ siloxane copolymer8 containing
vinyloxy groups described nor was it to be expected that
such copolymers can be obtained by addition (hydrosilyla-
tion) of SiH groups onto vinyloxy groups, since according
to EP-B 105 341, the introduction of a ~inyloxy group
into an organopolysiloxane i8 achieved only by hydro-
silylation of a compound which containQ an allyl group
and a ~inyloxy group, the addition taking place on the
allyl group.
Preferably, x is 2, 3 or 4 and Y is a di~alent,
tri~alent or tetravalent radical.
21~47~8
- 6 -
The organopolysiloxa~es according to the inven-
tion whlch contain ~inyloxy group~ preferably have a
~i~cosity of 5 to 5x105 mPa s at 25C, preferably 50 to
50000 mPa-~ at 25C.
5The ~iloxane content in the ~iloxane copolymer~
according to the in~ention which contain ~inyloxy groups
i8 preferably 20 to 90% by weight, ba~ed on the total
weight of ~iloxane copolymers containing vinyloxy groups.
Examples of radicals R are alkyl radicals, such
as the methyl~ ethyl, n-propyl, i~o-propyl, 1-n-butyl,
2-n-butyl, i80 -butyl~ tert-butyl, n-pentyl, i 80 -pentyl,
neo-pentyl and tert-pentyl radical; hexyl radicals, such
as the n-hexyl radical; heptyl radical&l ~uch as the
_ n-heptyl radical; octyl radicals, such a~ the n-octyl
15radical aad i80~0ctyl radical~, 2uch a~ the 2,2,4-
trimethylpentyl radical; nonyl radicals, such as the
n-nonyl radical; decyl radical~, such as the n-decyl
radical; dodecyl radical~, such as the n-dodecyl radical;
octadecyl radicals, such as the n-octadecyl radical;
cycloalk~l radical~, such as cyclopentyl, cyclohexyl and
cycloheptyl radicals and methylcyclohexyl radicals; aryl
radicaln, su~h as the phenyl, naphthyl, anthryl and
phenanthryl radical; alkaryl radicals, such as o-, m- and
p-tolyl radicals; xylyl radical~ and ethylphenyl
radical~; and aralkyl radicals, 3uch a~ the benzyl
radical and the a and ~-phenylethyl radical. The methyl
radical is preferred.
Examples of halogenated radicals R are halogeno-
alkyl radicals, such as the 3,3,3-trifluoro-n-propyl
30radical, the 2,2,2,2',2',2'-hexafluoroisopropyl radical
and the heptafluoroisopropyl radical, and halogenoaryl
radicals, 3uch as the o-, m- and p-chlorophenyl radical.
Examplea of alkyl radical~ R~ are the methyl,
ethyl, n-propyl, iso-pr.opyl, 1-n-butyl, 2-n-butyl, i80-
butyl and tert-butyl radical~ The methyl and ethyl
r~dical are preferred. Exa~ple~ of alkyl radical~ R1
which are ~ubstituted by an ether oxygen atom are the
methoxyethylene and ethoxyethylene radical.
Example~ of alkyl radical~ Ra are the methyl,
- ~13~
, - 7
ethyl, n-propyl, i~o-propyl, 1-n-butyl, 2-n-butyl, i~o-
butyl, tert-butyl, n-pe~tyl, iso-pentyl, neo-pentyl and
tert-pentyl radical and hexyl radicals, such aR the
n-hexyl radical.
Preferred ~iloxane copolymer~ containing vinyloxy
grol~p~ are those which compri~e
(a) siloxane u~itR of the formula
R2SiO ~I') ,
(b) per molecule, at least two siloxane unit~ of the
formula
GR2SiO1~2 ~II') a~d
per molecule, at least one unit of the formula
0l/2R2siGlsiR2ol~2 (III')
wherein R, G~and G1 ha~e the meaning gi~en a~ove for
1~ these radicals.
Examples of the organic compound (1) which
contains ~ore than one ~inyloxy group and i 8 employed in
the proce~s according to the invention are those of the
formula
20CH2=C~-O-CH2-CH2-0-CH=CH2
CH2=CH----( CH2 ) 4--0--CH=CH2
,
CH2=C~----(CH2CH20)3-CH=CH2
CH2=c~-o-tc~2c~2c~2c~2o)n-cH-c~2 n=2-6
C~;2 -C~2
CH2=C~-O--C~2-c~ CH-C}I2-0-c~=c~2
cX2 -CH2
`- ~13 1~
.- 8 -
O-CH=CH2
CH2=CX--0--CH--C:i2 -0-CH=CH2
1 ~2----CH=c-i2
CX3-C-CH2-0-cH=c~2
CY2-0-C~=CX2
C~3-cLc~2-otc~c~2o)m-cH=c~2~3 m=l-10
CH2-0-C~=CEi2
C~3--C~2- 1C--C~2--0--CH=CH2
~n2 ~0~C~=Cn2
3-c~2-ctc~2-o(c~2cH2o)m-cH=c~2]~ m=l-10
CX2 -0--C~=CX2
}IO--CH2 -C-C~2 -0--CH=C~2
~ ~ CH2--0--C~=CH2
,. - ~, .
c~2--o--CH=C~2
CH2=CH-O--CH2--C-C~2-0-CH=CH2
C~2 -0-CX=C~2
(C~2=C~-0)2C~C~(O-cH=c~2)2
- (C~2=cH-~)2c~cH2c~(o-cH-c~2)2
CH3C(O-CH=cH2)3
(CX2=CY-o)cx2~cH(o-c~=c~2)]3cH2(o-~x=~2) and
13 i 7~ g
- 9
( cU.2=cu.-O ) C~2 t C~I ( O--C~=CH2 ) ] 4 CH2 ( 0--cH=cH2 )
Pref err~d example~ of the organic compound ( 1 )
are
C~2~C~-o--~ C~I2 C~i~ O ) 3 -CH=C~I2
C~I2 -CH~
I
~2=~ ~-0-C~2-C~ C~--CH2-0-C~=CX2
C~i2 -CH2
CH3 -C ~ C~2--0--CH--C~2 ] 3
CH3-c~c~2-o (cH2cx2o~m-/~H=cH2] 3 m=l-10
CH3 -CX2-C ~ C~I2-0-CH=C~2 ~ 3 and
CX3-C~2-C ~ C~2- (CH2C~20) m-CH=CH2 ] 3 m=l-lo .
Exam~?les of the radical Y are therefore those of
the fonnula
- (C}I2) 2
~ (C~2) ~ ~
- (C~I2cH20) 2-C' 2-C~2-
( CH2 Cr~2C~2 C~20 ) n- ~ C~2 C~2 CH2 CH2 - n=2--6
C~i2-C'' 2
-CX2-CY' C':.-CH2-
c~;2 -Ci2
--C~--CY2--
2 1 3 4 ~
- -- 10
CH2 -
CH3 -C-CX2 ~
CH2 - .
CH3 -C ~ CH2 - ( CH2 CX20 ) m-1C~2 C~2 ~ ] 3 m--1-10
lcx2-
CY.3--C~2--c--c~2
CX2 -
C~i3-CH2~C~CX2-0(cH2c~2c))m-lc~2c~2~~3 m=l-10
CH2 -
I
HO--CH2 -C-C~2 -
CH2-
C~;2-
'~ I '
-CX2-C-C~2-
C~2-
--C~--CY--
-CH-CH2 -CX-
CH3C-
I I I
-CX2-CH-CH-CH-C~2- and
11 - 213 17!~g
-'CH2 -CH-C~-C.i-C}i-C~2 -
Proce~se~ for the preparation of the organlc
¦ compound (1) are described, for example, in PCT Applica-
tion WO 91/05756- The basis of the prepara~ioIl iB the
Reppe ~inylation which i8 known to the expert, in which
alcohols are reacted catalytically with acetylene.
Typical impurities of industrial ~inyl ethers are
vinyl ether-alcohols, which are retained a~ "intermediate
~tages" due to incomplete ~i~ylation, and, where approp-
- riate, secondary products thereof formed by self-cyclisa-
: 10 tion, such as, for example:
. .
-CH2 C'i2-OH
\ /
~ ~ C - >
I \
~, :CH2--CK--O--CH2 CH2--0-CX=cH2
CX3 -CH2 C~2 -
C C~-CX3
CH2=cH-o-cx2 CX2-0
Organopolysiloxanes (2) ha~ing at least one Si-
bo~ded hydrogen atom which are preferably employed in the
~:: process according to the in~ention are those of th~
general fornula
HeRfSiO4-(e~f~ (VI)
:: 2
wherein R has the meaning gi~en abo~e for this radical,
~: e i8 0 or 1, on a~erage 0.005 to 1.0,
f i3 O, 1, 2 or 3, on a~erage 1.0 to 2.5, and
the 8um of elf is not greater than 3.
Organopolysiloxanes (2) ha~ing at least one Si-
~:~ bonded hydrogen atom which are preferably employed in the
213~7~o
- 12
proce~fi according to the in~ention are those of the
general formula
EdR3 dsio (siR2o) 0 (SiR~o) pSi:lR3dH~, (VII)
wherein R has the meaning given above for thi3 radical,
S d is identical or different and i~ 0 or 1,
o denotes 0 or an i~teger rom 1 to 1000 and
p denotes 0 or an integer from 1 to 6.
The organopoly6iloxane~ (2) employed in the
process according to the invention particularly prefer-
ably contain 2 to 6 Si-bonded hydrogen atoms per mole-
cule.
_ The organopoly~iloxane~ (23 which have at lea~t
one Si-bonded hydrogen atom per molecule pre erably have
a visco~ity of 0.5 to 20,000 mP~ 8 at 25C, preferably
to lO00 mPa 8 at 25C.
Preferred example~ of organopolysiloxane~ of the
formula (VII~ are copolymers of dimethylh~drido~iloxane
and dimethylsiloxane unit~, copolymers of dimethyl-
hydridosiloxane, dimethylsiloxane and methylhydrido-
~iloxane units, copolymers of trimethylsiloxane andmethylhydridosiloxane units and copolymers of trimethyl-
siloxane, dimethyl~iloxane and methylhydrido~iloxane
unit~.
Processes for the preparation of organopolysilox-
anes which have at least one Si-bonded hydrogen atom per
molecule, including tho~e of the preferred type, are
generally known.
- The organic co~pound (l) i8 employed in the
process according to the invention in amounts such that
the aliphatic double bond in the organic compound (1) is
present in a ratio to the Si-bonded hydrogen in the
organopoly~iloxane (2) of preferably 1.5:1 to 20:1,
preferably 2:1 to 10:1. The organic compound (1) can be
combined with the organopolysiloxane (2) almost as
desired within very wide limit~, depending on its ~unc-
tionality and its molecular weight. However, a C=C:SiH
ratio of greater than 20:1 leads exclu~ively to mono-
~ 1 3 ~
- 13 -
hydrosilylation of the orgacic compou~d (1), which.is not
preferred.
The reaction of the organic compound (1), ~uch as
triethylene glycol di~inyl ether, with the organopoly-
siloxane (2), such as a,~-dihydridodimethylpoly~iloxane,
in the presence of the catalyst (3) proceeds in accord-
ance with the following equation:
. HSiMe20(9iMe20)~,,SiMe2X + C~12=C~IO- (CH2CH20)3-CH=C}I2 ------~
- CH2=~Ho-(c~2cH2o)3-cH2cH2siMe2o(siMe2o)~siMe2cH2cx2o-
- (Cx2cx2) 3-C~2CH25iMe20 (SiMe20) 3SiMe2C}I2CH2o-
(CH2CX20) 3CH=~H2
The cour3e of the reaction and therefore the
: resulting end product depends decisi~ely on the ratio
: employed between the C=C double bond in the organic
- :: 15 compound (1) and the -Si-bonded hydrogen in the organo-
polysiloxane (2). Depending on the ratio of C=C:SiH
employed - where the C=C:SiH ratio must always be greater
: than 1 - ~iloxane copolymers which contain free ~inyloxy
groups of the formula
-OC~=C~,
. :
~:~ : at the chain end and along the chain (for example if an
orga~nic compound (1) ha~ing more than two vinyloxy groups
usedj are obtained, it being possible for branchings to
occur along the chain by further reaction of the free
~ 25 vinyloxy groups along the chain with the Si-bonded
, hydrogen atoms of the organopolysiloxane (2).
Catalysts (3) which promote the addition of Si-
~; ~ bonded hydrogen onto an aliphatic multiple bond and which
can be employed in the process according to the in~ention
;~ 30 are al~o the same catalysts which it has also been
possible to employ to date for promoting addition of Si-
bonded hydrogen onto an aliphatic double bond~ The
: cataly~ts (3) are preferably a metal from the group of
; platinum metal~ or a compound or a complex from the group
1317(~8
- - 14 -
of platinum metals. ~xamples of such catalysts are
metallic and finely divided platinum, which can be on
support~, ~uch as silicon dioxide, al~l~inium oxide or
active charcoal, compounds and complexes of platinum,
such as platinum halides, for example PtCl" ~2PtClc~6H20
or Na2PtCl~4H20, platinum-olefin complexe~, platinum-
alcohol complexes, platinum-alcoholate complexes, plati-
num-ether complexes, platinum-aldehyde complexes,
; platinum-ketone.complexes, including reaction products of
H2PtClc*6H30 and cyclohexanone, plati~um-~inyl~iloxane
complexes, such as platinum-1,3-divinyl-1,1,3,3-tetra-
methy}disiloxane complexes with or without a content of
detecta~le inorganically bonded halogen, bis-(gamma-
picoline)-platinum dichloride, trimethylenedipyridine-
platinum dichloride, dicyclopentadiene-platinum
dichloride, dimethyl sulphoxide-ethyle~e-platinum(II)
dichloride and reaction products of platinum tetra-
~:: chloride with an olefin and primary amine or secondary
amine or a primary and secondary amine according to US-A
: 20 4,292,434, such as the reaction product of platinum
tetrachloride diRsolved in 1-octene with sec-butylamine,
and ammonium-platinum complexes according to EP-B
110 370, and compounds and complexes of rhodium, such as
the rhodium complexes according to EP-A 476 426.
2~5 The catalyst (3) i8 preferably employed in
amounts of 2 to 1000 ppm by weight (parts by weight per
million partq by weight), preferably in amounts of 10 ~o
50 ppm by weight, in each case calculated as elemental
platinum and based on the totaI weight of organic com-
pound (1) and organopolysiloxane (2).
The process according to the invention is prefer-
ably carried out under the pressure of the surrounding
atmosphere, that is to say under about 1020 hPa (abso-
lute); but it can also be carried out under higher or
lower pressures. Furthermore, the process according to
the invention is preferably carried out at a temperature
of 50C to 170C, preferably 80C to 150C.
Inert, organic solvents can be co-used in the
process according to the invention, although the co-use
- 2 1 ~
- 15 -
of inert organic ~olvent~ is not preferred. Example~ of
inert oxganic ~ol~ent~ are toluene, xylene, octane
isomers, butyl acetate, 1,2-dimethoxyethane, tetrahydro-
furan and cyclohexane.
Exce~s organic compound (1) and any inert organic
sol~ent which haR been co-used are preferably remo~ed by
di~tillation from the ~ilox ne copolymers prepared by the
process according to the invention and containing ~inyl-
oxy groups.
The siloxane copol~mer~ prepared by the process
according to the invention and containing ~inyloxy group~
are equilibrated with an organopolysiloxane (41, if
appropriate.
_ Organopoly~iloxane~ t4) which are used are
preferably those chosen from the group co~prising linear
organopolysiloxane~ co~taining terminal triorganosiloxy
group~, of the formula
R3SiO(5iR2O)rSiR3
wherein R has the meaning gi~en above for this radical
and r i~ 0 or~an integer ha~ing a ~alue from 1 to 1500,
linear organopolysiloxanes containing terminal hydroxyl
groups, of the formula
HO(SiR2O),H
wherein R has the meaning given abo~e for this radical
and 8 is an integer having a ~alue from 1 to 1500,
cyclic organopolysiloxane~ of the formula
(R2SiO) ~
wherein R haR the meaning gi~en abo~e for this radical
a~d t is an integ~er from 3 to 12,
and copolymers of units of the formula
R2SiO and Rsi3~a
-- ~13~7~
wher in R has the meaning gi~e~ abo~e for thi~ radical.
The ratio of the amount~ of the orga~opoly~ilox-
ane (4) employed in the equilibration which i~ to be
carried out if appropriate and th~ siloxane copolymers
containing ~i~yloxy group3 i5 determined ~erely by the
desired content of ~inyloxy group~ in the siloxane
copolymers produced by the equilibration which i~ carried
out if appropriate and by the de~ired average chain
length.
Basic catalyst3 which pro~ote the eguilibration
are preferably employed in the e~uilibration which i8
carried out if appropriate. Examples of ~uch cataly8t8
are alkali metal hydroxides, ~uch as sodium hydroxide and
- potas~ium hydroxide, trimethylbenzylammonium hydroxide
and tetra~ethylammonium hydroxide. Alkali metal hydrox
ides are preferred. Alkali metal hydroxide~ are preer-
ably u~ed in amou~ts of 50 to 10,000 ppm by weight
(= parts per millio~), in particular 500 to 2000 ppm by
weight, in each case based o~ the total weight of ~ilox-
ane copolymer containing vinyloxy group~ employed and
organopolysiloxane (4) employed. Although it is possible
to use acid equilibratio~ cataly~ts, this i8 not pre-
ferred.
The equilibration which i8 carried out if approp-
riate is preferably carried out at 100C to 150C under
the pre~Qure of the surrounding atmosphere, that i~ to
say at about 1020 hPa (absolute). If desired, howe~er,
higher or lower pressures can also be used. The equili-
bration i8 preferably carried out in a concentration of
5 to 20~ by weight, based on the total weight of the
particular siloxane copolymer containing ~inyloxy groups
employed and organopolysiloxane (4) employed, in a water-
immi~cible sol~ent, ~uch as toluene. The catalyst can be
rendered inacti~e before the mixture obtained in the
equilibration is worked up.
The proces~ according to the in~ention can be
carried out batchwise, ~emi-continuously or completely
continuously.
The siloxane copolymers according to the in~en-
. ~
213~
- - 17 -
tion which contain ~inyloxy groups can be cros~linked
cationically, for example by addition of acids, such a~
hydrochloric acids, ~ulphuric acid~ or p-toluene~ulpho~ic
acids. The siloxane copolymer~ according to the in~ention
which contain ~inyloxy groups are pr.eferably cros~linked
in a cationic polymeri~ation iaitiated by light. Cata-
ly ts which are used for the cros~linking initiated by
light are preferably onium salts, such a~ diaryliodonium
salts or triarylsulphonium salt~, which are known from
EP-B 105 341 and the German application by the Applicant
Company ha~ing the application number P 41 42 327.5.
Examples of such onium salts are the bis-(dodecylphenyl)-
iodonium salts described in EP-B 105 341, such as bis-
- (dodecylphenyl)iodonium hexafluoroantimon~te or bi3-
~dodecylphenyl)iodonium hexafluoroar~enate, or the
iodonium ~alts of the formula
~ J~- ~ D X~
wherein D danotes a radical of the formula
-O-R~-SiR3
wherein R~ denotes a di~alent hydrocarbon radical ha~ing
1 to 18 carbon atoms per radical, which i~ optionally
interrupted by at least one oxygen atom and/or one
sulphur atom and/or one carboxyl group,
R5 denotes a mono~alent hydrocarbon radical ha~ing 1 to
18 car~on atoms per radical, which is optionally inter-
rupted by at least one oxygen atom, and
X~ is a tosylate anion or a weakly nucleophilic or non-
nucleophilic anion Y~ chosen from the group comprising
CF3CO2-, BF~-, PF6-, AsF6, SbFC-, ClO~, ~SO~, CF3SO3 and
C~FgSO3~
which are described in the German applicat~on having the
application number P 41 42 327.5.
The in~ention therefore relates to the use of
siloxane copolymers containing ~inyloxy groups, prefer-
- ~13~7~
- 18 -
ably compri~ing units of the formula (I), (II) and if
appropriate at least one of the units of the formula
(III), (IV) or ~V), preferably comprising unit~ of the
formulae (I'), (II') and (III'), in compo~itions which
can be crosslinked by light and are based on the abo~e-
mentioned ~iloxane copolymers.
The siloxane copol~mer~ according to the inven-
tion which contain vinyloxy group~ are preferably cro~-
linked by ultra~iolet light, that ha~ing wavelengths in
the range from 200 to 400 nm being preferred. The
ultraviolet light can be generated, for example, in xenon
or low, medium or high pressure mercury lamp6.
Ultra~iolet light ha~ing a wa~elength of 400 ts 600 nm,
_ that i_ to say Qo-called "halogen light" i8 al80 suitable
for the crosslinking by light. The siloxane copolymers
according to the in~ention which contain vinyloxy groups
can be cro~slinked by light in the ~isible range if
; commercially a~ailable photosensitisers are also u_ed.
Thz cationic polymeri~ation of the silox~ne
copolymers according to the in~ention which contain
~inyloxy groupQ can of course also be initiated by
Bro~sted or Lewis acids customary for this purpose.
Finally, the invention also relates to the use of
the siloxane copolymer~ according to the in~ention which
contain ~inyloxy group_ for the production of coatingQ
which can be crosslinked by light.
The siloxane copolymers according to the inven-
tion which contain Yinyloxy groups can be used in radia-
tion-curing printing inks.
Example~ of surfaces onto which the coatings
according to the in~ention can be applied are those of
paper, wood, cork, fil~s of plastic, for example poly-
ethylene film~ or polypropylene film~, ceramic objects,
glass, including glass fibres, metals, pa~teboard,
including that of asbestos, and wo~en and non-wo~en cloth
of naturally occurring or synthetic organic ~ibre~.
The application of the siloxane copolymers
according to the in~ention which contain ~inyloxy groups
to the surfaces to be coated can be carried out in any
.
o'
- 19 -
¦ desired ~aDner which i8 suitable a~d in many cases known
for the production of coatings from liquid substance ,
for example by dipping, brushing, pouring, spraying,
rolling, prin ing, for example by ~e~s of an o~fset
gravure coating device, or knife or doctor blade coating.
Example 1:
238 g of a copolymer of hydridodimethylsiloxane
and dimethylsiloxane units ha~ing a viscosity of 11 mm2/s
at 25C, corresponding to 0.5 g o~ Si-bonded hydroge~,
together with 78.5 g of the ~inyl ether of the formula
C~i2 -C~2
`CH2=CX--O--C~2-C~ C~-C~2--0--CH=CH2
CH2-CH2
obtainable from GAF Chem. Corp. under the trade ~ame
Rapi-Cure CXVE, are heated at 50C under a nitrogen
atmosphere. 4 mg of platinum are added in the form of a
1~ ~olution of ~2PtCl6xH20 in isopropanol, after which the
te~perature of~the reaction mixtura rises to about 130C.
The mixture is allowed to react at thi~ temperature for
a further hour, a con~ersion o~ more than 99~ being
achieved. 315 g of a copolymer which comprises alternat-
ing siloxane and aliphatic ether blocks and has a vis-
cosity of 9O 32/~ at 25C are obtained. In accordance
with the preparation method, the linear block copolymer
containQ ~inyl ether end groups, the average molecular
weight being 1900. The product has a surface tension of
22 mN m~l.
Example 2:
336 g of of an a,~-dihydridodimethylpolysiloxane
having a content of 0.149% of Si-bonded hydrogen are
- mixed under turbulent conditions with 67 g of triethylene
~0 glycol divinyl ether (obtainable under the trade name
Rapi-Cure DVE-3 from GAF Corp.) and the mixture is heated
to about 80C. A solution of 14 mg of platinum tetra-
chloride in a little 1-octene i8 added under a nitrogen
2 1 '~
- - 20 -
atmosphere, after which the mixture heat~ up to 135C.
This temperature i~ maintained for a further hour and the
mixture i~ cooled. In accordance with the ~ynthesis, the
product has the structure of a linear block copolymer of
S dimethylpolysiloxa~e and polyglycol chains having 2-~inyl
ether end groups- The viscosity at 25C i~ 23S mml/s, and
the a~erage molecular weight iB about 6000. The siloxane
content is about 83~ by weight (from the lH-N~R
spectrum).
Example 3:
403 g of ~,~-dihydridod~methylpolysiloxane ha~ing
a total of 0.25 g of Si-bonded hydrogen are mixed with
42 g of triethylene glycol di~inyl ether (obtainable
- under the trade name Rapi-Cure DVE-3 from G~F Corp.) at
90C under nitrogen. 24 mg of hexachloroplatinic acid
dis olved in a little isopropanol are added. A~ter the
internal te~perature has risen, the mixture is allowed to
react at 130C for another 3 hours, until a conversion of
more than 99% is reached. Volatile co~titue~ts are
removed at 100C under 5 hPa, after which a clear oil
ha~ing a viscosity of 220 mm2/s at 25C i8 obtained. The
strUcture in principle corresponds to the polymer product
from Example 2; the siloxane chain length is now greater
but the dimethylpolysiloxane chains alternate less often
with the polyglycol chains. The siloxane content is now
91% by weight, at about the Qame a~erage molecular
weight.
Example 4:
170 g of copolymer of trimethylsiloxane,
dimethylsiloxane and hydridomethylsiloxane units having
a ~iscosity of 90 mm2/s at 25C and a total of 80 mg of
Si-bonded hydrogen are mixed with 29.5 g of the ~inyl
ether Rapi-Cure CHVE, which is described in Example 1,
and 4 mg of platinum in the form of a solution of PtCl~
in 1-octene. The mlxture i8 heated at 120C ~nder
nitrogen for 3 hours, ~olatile contents are stripped off
under 5 hPa, and a clear oil ha~ing a ~iscosity of 28Q
mm2/s at 25C is obtained. The copolymer has a branched
structure, siloxane chains being bridged by aliphatic
-
213~76
- 21 -
ethers and at the same time having lateral vinyl ether
groups~ It contains about 0.3 mol of vinyl ether double
bonds per kg.
Example 5:
170 g of copolymer of trimethylsiloxane, di-
methylsiloxane and hydridomethyl~iloxane u~its having a
viscosity of 90 mm2/R at 25C are mixed with 20 g of the
vinyl eth~r Rapi-Cure DVE-3~ which i8 described in
Example 2, and the mixture i8 heated to 100C under a
nitrogen atmosphere. After addition of 10 mg of ~2PtCl6 x
X20, dissolYed in a little isopropanol, the internal
temperature rises to just about 120C, where it i~ kept
for a further 3 hours. After removal of volatile con-
~ stituents in vacuo under 5 hPa, 175 g of a branched block
copolymer of ~iloxane chain~ with polyglycol bridges and
SiC-bonded vinyl ether groups are obtained after filtra-
tion. The polymer product has a viscosity of 1200 mm~/8
at 25C and about 0.25 ~ol of vinyl ether double bonds
per kg.
Example 6:
4 mg of platinum in the form of a platinum-1,3-
divinyl-1,1,3;3-tetramethyldisiloxane complex are added
to 202 g of the vinyl ether Rapi-Cure DYE-3, which is
described in Example 2, and the mixture is heated to 90C
under a nitrogen atmosphere. A total of 69 g of 1,3-
dihydridotetramethyldisiloxane are metered in over a
period of about 1.5 hour~, and the reaction is brought to
completion at about 130C. After removal of volatile
compound~ at 160C under 5 hPa, a polymeric difunctional
vinyl ether having a ~iscosity of 44 mm2/s at 25C is
obtained in a quantitative yield. It can be seen from the
~_NMR spectrum that the C=C/SiCH2 ratio has a ~alue of
0.61. The product contains 2.6 mol of vinyl ether double
~onds per kg. It has a surface ten~ion of 28 mN m-l.
Example 7:
To prepare a vinyl ether/siloxane copolymer
branched via the ether blocks, Example 1 is repeated with
100 g of trimethylolpropane trivinyl ether instead of the
divinyl ether used therein. After the end of the
- 2i3~7~
- 22 -
hydrosilyl~tion reaction, the excess vinyl ether i~
removed at 160C under 3 hPa, after which a clear ail
having a viscosity-of 145 mm2/s at 25C i3 obtained. The
branched block copolymer contains di~inyl ether end
groups and a siloxane content of 76% by weight. It
contains about 1.6 mol of vinyl ether dou~le bonds
per kg.
Example 8:
10 g of the block copolymer prepared in Example 6
are mixed with 0.1 g of [4-[2-(3-dioctylmethylsilyl-
propyloxy)ethoxy]phenyl]-iodonium hexafluoroantimonate
(preparation described in the German application ha~ing
the application number P 41 42 327.5) at 22C and the
mixture is applied in a thin layer of about 4 ~m to
polyethylene-coated paper using a glass rod. After an
exposure t~me of 0.15 second using a medium pressure
mercury lamp (80 watt/cm) at a distance of 10 cm, the
b}ock copolymer has hardened to an abrasion-resistant
p~roduct.
Example 9: ~
17C g of the copolymer used in Example 4 are
mixed together with 17 g of butane-1,4-diol divinyl
ether, inhibited with 100 ppm of ROH, and 2 mg of plati-
num in the form of its 1,3-di~inyltetramethylsiloxane
complex,~ and the mixture i~ heated to 136C. After a
reaction time of 3 hours under nitrogen, more than 97% of
the acti~e hydrogen groups ha~e been consumed, after
- which excess di~inyl ether is remo~ed at 160C under
5 hPa. A branched copolymer of aliphatic ether units and
30 siloxane blocks ha~ing a ~i8c08ity of 330 mm2 8~l at 25C
j - ~ i8 obtained. It contains about 0.27 mol of ~inyl ether
double bonds per kg.
~.' .
:
