Note: Descriptions are shown in the official language in which they were submitted.
-- 2
The invention relates to novel ethylenically unsaturated
resinous compounds and to their preparation. The novel
compounds can be cured by U.V. radiation, and they are
particularly useful for application in coating compositions
and printing inks. Special advantages of the present
ethylenically unsaturated compounds are the fast cure
by U.V. radiation and the absence of tackiness after
cure (tackiness after cure is one of the most troublesome
drawbacks, caused by air inhibition, which this type of
resins quite often display). The valuable properties of
the novel resinous compounds-areattributed to their
structure and to the selection of components for their -~
manufacture. The invention relates further to compositions
containing in addition other ethylenically unsaturated
compounds having a low viscosity, and to compositions
containing other types of additives, such as photo-initiators,
fillers, colourants and pigments. The invention further
relates to the use of the novel compounds in radiation
cure processes.
In recent years processes have been developed for
cure of ethylenically unsaturated resins by radiation,
in particular by electron beam radiation and by U.V. light.
Such radiation processes can find application in the field
of surface coatings and for printing inks. These processes
enable a very fast cure, at ambient temperature, in
a way that flat substrates with a coverage of uncured
resinous materials can be conveyed at high speed to a
~ '
'
1~64~
-- 3 --
place where a short exposition to the radiation will
effect cure Or the resinous materials, and the treated
article can be further processed without delay.
Interest in electron beam cure has led to proposals
for certain types of resins. The advantage of electron
beam cure is the very high energy of the electrons
emitted, which is usually between 100,000 and 500,000
electron volts; this energy is high enough to initiate
polymerization of substantially any type of ethylenically
~- 10 unsaturated compound without use of auxiliary materials.
Drawback, however, is the very high cost of the electron
generator and of the heavy and complicated screening
which is necessary to protect production staff against
the X-rays emitted when theelectrons are slowed down.
U.V. radiation as polymerization initiator has the
advantage of lower cost of apparatus and screening;
however, the quantum energy is considerably lower (3,3
~ electron volts for U.V. radiation of 360 nm) and the
- use of photo-initiators (also named sensitizers) is
required to initiate the polymerization. As the U.V.
radiation has lower energy than the electron beam,
more specific selections of resinous materials will
be required for a complete and fast cure. In practice,
resins for U.V. cure have generally been of the
unsaturated polyester type.
A drawback common to most resins in radiation cure
systems is the air inhibition phenomenon, which means
_ 4 _
that in contact with air the surface of the cured layer
tends to remain sticky even when the underlaying parts
of the layer have hardened completely. This phenomenon
has often to be eliminated by additional measures
to protect the surface of the uncured material from
interaction with oxygen, such as use of paraffin wax
to cover the surface, or the use of inert gas in the
conveyor street, or coverage of the surface by a thin
clear thermoplastic sheet.
The invention is concerned with a resinous material,
suitable for fast cure by U.V. radiation in contact with
air, to provide a cured material having a tack-free
- surface without specific precautions.
Some further advantages will be clear from the
followi-ng specification.
The invention provides an UV-curable ethylenically
~.-, , .
unsaturated resinous compound, comprising the reaction
product of (I) one mole of a polyhydroxy compound having
m hydroxy groups per molecule, wherein m has a value
of at least 2, (II) n moles of a diisocyanate, (III)
1 to n moles of an adduct of equivalent amounts of
acrylic acid and a glycidyl ester of saturated aliphatic
monocarboxylic acids in which carboxylic acids the
carboxyl group is attached to a tertiary or quaternary
carbon atom and which carboxylic acids have 9 to 11
carbon atoms per molecule, and (IV) (n-1) to 0 moles
of a hydroxyalkyl acrylate of the formula
" H
HO - R - 0 - C - C = CH2
wherein R is a divalent alkyl group, the sum of the number
of moles of components (III) and (IV) being n, n being
smaller than or equal to m, and the value of n being
at least 2.
The polyhydroxy compounds O have preferably 2 to 6,
more preferably 3 to 6 hydroxy groups per molecule. Examples
of polyhydroxy compounds are polyhydric alcohols such
as glycerol, pentaerythritol, trimethylol ethane, trimethylol
propane, 1,2,6~hexane triol, sorbitol and reaction
products of these alcohols with ethylene oxide or
propylene oxide in a molar ratio of from 1:1 to 1:20;
the latter, so-called tipped polyols, contribute to
the flexibility of the cured product. Other polyhydroxy
compounds are condensation products of polycarboxylic
acids or their anhydrides and optionally monocarboxylic
acids with an excess of a polyhydric alcohol, such as
compounds of the alkyd resin type. Other suitable poly-
hydroxy compounds are solid reaction products of polyhydric
phenols such as 2 3 2-bis(4-hydroxyphenyl)propane with
epichlorohydrin having Durrans' softening points between
; 60C and 100C, and having 2 to 4 hydroxy groups per
molecule; these reaction products have also about 2 epoxy
groups per molecule, which may be suitable for a secondary
-
-- 6 --
slower cure with polyamines. Other suitable polyhydroxy
compounds are diacrylates of diglycidyl ethers of
polyhydric phenols such as 2,2-bis(4-hydroxyphenyl)propane;
the acrylates are obtained by reaction of 2 moles of
acrylic acid with 1 mole of said diglycidyl ethers,
and obtain 2 hydroxy groups per molecule. Other polyhydroxy
compounds are castor oil and hydrogenated castor oil;
polymers of 2-hydroxyalkyl- and optionally alkyl esters
of acrylic or methacrylic acid; and triethanolamine.
Mixtures of two or more of the above named polyhydroxy
compounds may also be used. Preferred are polyhydric
alcohols, in particular those having 2 to 6 and preferably
3 to 6 hydroxy groups per molecule; particularly preferred
are trimetylol propane and its reaction products with
ethylene oxide in a molar ratio of from 1:6 to 1:20, and
sorbitol.
Examples of diisocyanates are meta- and para-phenylene ~-
diisocyanate, toluene-2,4- or 2,6-diisocyanate and mixtures
of these isomers, m-xylene diisocyanate, naphthalene-1,5-di-
isocyanate, diphenyl methane diisocyanate, diphenyl-4,4'-
diisocyanate, 3,3'-dichloro diphenyl 4,4'-diisocyanate~
3,3'-dimethoxy diphenyl-4,4'-diisocyanate, 3,3'-dimethyl
diphenyl-4,4'-diisocyanate, 3,3'-bisphenyl diphenyl-4,4'-
diisocyanate, 3,3'-dimethyl dlphenylmethane-4,4'-di-
isocyanate, diphenyl ether 4,4'-diisocyanate, N,N'-bis
(4-methylphenyl)uretidindion 3,3'-diisocyanate, butane-
1,4-diisocyanate, hexane-1,6-diisocyanate, 2,2,4-trimethyl
.
,:
hexane diisocyanate, dodecane-1,12-diisocyanate,
cyclohexane diisocyanate, di(cyclohexylmethane)4,4~-
diisocyanate, 2-butene-1,4-diisocyanate, diethyl-
sulphide 2,2'-diisocyanate, and isophorone diisocyanate.
Mixtures of two or more of those diisocyanates may
also be used. The diisocyanate may be a crude product, or
may have been purified, for example by distillation
or crystallization; solid diisocyanates may have
been liquified to facilitate handling. One mole of
diisocyanate is defined as the amount containing two
isocyanate equivalents.
Component III can be prepared by heating equimolar
amounts of the components at temperatures from 100 to 150C
in the presence of a catalyst (an organic phosphine,
a phosphonium salt, a tertiary amine, or a quaternary
ammonium salt) and preferably in the presence of an
inhibitor, for example hydroquinone, until determination
of the epoxy content shows that the reaction is sub-
' stantially complete.
The acids from which the glycidyl esters are made
will for convenience further be named "branched mono-
carboxylic acids~'. Aliphatic in the definition of the
' branched monocarboxylic acids will in this connection
include acyclic aliphatic as well as cycloaliphatic.
Branched monocarboxylic acids can be obtained by
reaction of formic acid or carbon monoxide and water
with olefins such as cracked mineral oil fractions,
.. - . : , ....................................... .
- : . ,
"~ ' ,
- 8 -
.
propylene trimer, or diisobutylene in the presence
of liquid strongly acidic catalysts, and such
branched monocarboxylic acids are usually mixtures
in which the carboxyl group is predominantly attached
to a quaternary carbon atom.
Component (IV) may be, for example, hydroxyethyl
acrylate or hydroxypropyl acrylate.
The relative amounts of components (III) and (IV)
may be varied, with the condition that at least 1 mole
of component (III) is used in the preparation of 1 mole
of the ethylenically unsaturated resinous compound as
defined above. The amount of component (III) may vary
from 1 to n moles per mole of ethylenically unsaturated
resinous compound, and accordingly the amount of component
(IV) may vary from n-1 to 0 moles, the sum of the number
of moles of components (III) and (IV) being n. The value ~`
of n is equal to or smaller than the value of m; the
minimum value f~)r both is 2. In the cases that n is
smaller than m the resinous compound will contain m-n
hydroxy groups per molecule.
The ethylenically unsaturated resinous compounds
as defined above are prepared from the components as
defined above, preferably by two routes, each route
being a two-stage process.
The preferred route is to react first the components (III)
and optionally (IV) with the diisocyanate, preferably
in the presence of a catalyst for isocyanate/hydroxy
' ' ,. :
: '
-
L~
reactions. Such catalysts are known; examples are:
dibutyl tin dilaurate, cobalt naphthenate, and tertiary
amines such as triethyl amine, N-methyl morpholine,
triethylene diamine. Further, as the acrylate ester used
may polymerize spontaneously, an inhibitor such as
hydroquinone should be present in sufficient amount in
any stage of the reactions. Reaction temperatures of
from 20 to 100C may be contemplated, preferred reaction
temperatures (using dibutyl tin dilaurate as catalyst)
being 40-80C. To raise the selectivity in reacting
only one isocyanate group of the diisocyanate, the
monohydroxy compounds (III) and optionally (IV) are
preferably added slowly, over some hours, to the
diisocyanate. If both components (III) and (IV) are
used, it is preferred (in view of a possible difference
in reactivity) to react each of them separately with
an equimolar amount of diisocyanate, and to mix the
resulting products; if the reactivity is about the
same, a mixture of (III) and (IV) may be added.
; 20 In the second stage of this first route the polyhydroxy
compound is added, if desired with supplementary amounts
of catalyst and/or inhibitor, and the reaction is
allowed to proceed, preferably at a similar temperature
as that during the first stage until isocyanate analysis
shows that the reaction is substantially complete.
:
- - 10 -
This route will allow the preparation of resinous
compounds having free hydroxy groups (m-n per molecule).
The first route is defined as a process for the
preparation of an UV-curable ethylenically unsaturated
resinous compound wherein first n moles of a diisocyanate
(II) are reacted with 1 to n moles of component (III)
and (n-l) to 0 moles of component IV, the sum of
the number of moles of components III and IV being n,
and wherein n moles of this product is reacted in a second
stage with 1 mole of the polyhydroxy compound (I) having
m hydroxy groups per molecule, n being smaller than or
equal to m.
In the second route the steps of the first route are
reversed: first the polyhydroxy compound is reacted with
the diisocyanate, and then the compound (III) and optionally
- (IV) are added. It will be clear that in this second route n
will have to be equal to m, to avoid high viscosity and even
- gelation as much as possible. An excess of components III
and optionally IV may be used to obtain a hydroxy-containing
product, in which the excess has the function of a reactive
diluent.There are indications that the second route is not
quite so selective as the first one, which would result
in a higher viscosity, and sometimes gelation. Therefore
usually the first route will be preferred. The second route
is defined as a process for the preparation of an UV-curable
ethylenically unsaturated resinous compound wherein first
,
: . . ' ':
4~
-- 11 --
1 mole of a polyhydroxy compound having m hydroxy
groups per molecule is reacted with n moles of a
diisocyanate, and this product is reacted in a second
stage with 1 to n moles of component (III) and (n-1)
to 0 moles of component (IV), the sum of the number
of moles of components (III) and tIV) being at least n,
and n being equal to m.
With regard to the ethylenically unsaturated resinous
compounds according to the invention as defined above
it should be kept in mind that the compounds or their
intermedi&tes in the first stage are not purified, and
that therefore the resinous compounds as defined are
intended to include all impurities formed by side reactions.
Further, the amount of component to be ~dded in the
second stage is commonly calculated on the base of the
isocyanate equivalency of the product of the first stage,
to account for side reactions in the first stage.
The ethylenically unsaturated compounds as def`ined
and described above are usually solids or highly viscous
liquids.The preferred compounds have on average more
than two UV~polymerizable ethylenically unsaturated
groups per molecule, and may be named "star shaped".
A variety of different ethylenically unsaturated
- compounds, of low viscosity, either alone or in mixtures
can be used as a diluent to bring the viscosity for
application as a coating or printing ink down to the
.
.
.
'
:
q~ ~
- 12 -
desired level. These low-viscous diluents polymerize
and copolymerize during UV-radiation, and so contribute
both to the reduction of viscosity and the weight
of the coating or print. These compounds of low viscosity
contain one or more ethylenically unsaturated groups
of the structure
H
- C = CH2
per molecule, and can be represented by the formula
H
R - C = CH2)
in which p is a number from l to 4, and R is a p-valent
~- hydrocarbon,ether, or ester residue containing no
urethane groups, and having up to 18 carbon atoms.
Examples are: styrene, vinyl esters of monocarboxylic
acids such as vinyl acetate or preferably vinyl esters
of "branched monocarboxylic acids" as hereinbefore
defined, the adduct of acrylic acid and glycidyl esters
of branched monocarboxylic acids ("component III"
as defined above), esters of acrylic acid and mono-
or polyhydric alcohols such as ethyl acrylate, butyl
acrylate, octyl acrylate, 2-ethyl hexyl acrylate,
hydroxyethyl acrylate, hydroxypropyl acrylate, neopentyl
glycol diacrylate, trimethylpropane di- and triacrylate,
pentaerythritol di-, tri, and tetraacrylate and mixtures
thereof, ethylene glycol diacrylate, diethylene glycol
diacrylate, polyethylene glycol diacrylates. Preferred
are diluents having a boiling point of at least 60C,
.:
; .' ' '' , ,:; ~
4~
- 13 -
more preferably above 100C, in particular above 150C,
at atmospheric pressure, as the function of the diluent
is to copolymerize, and not to evaporate. The amount
of diluent may be from 5 to 60, and is preferably from
20 to 40 parts by weight per 100 parts by weight of the
resinous compound. Diluents can often be added during
preparation of the resinous compound, in the first and/or
the second stage, to facilitate handling.
Examples of photo-initiators for UV cure are:
benzoin methyl ether, benzoin ethyl ether; 9,10-anthraquinone,
1,4-naphthoquinone and chloro, methyl, phenyl and benz-
derivatives of these two compounds. Preferred are benzoin
methyl (or ethyl) ether and 2-tertiary butyl anthraquinone.
The amount of photo-initiator is usually from 0.5 to 5
and preferably from 0.5 to 2 %w of resinous compound
plus diluent.
- Compositions containing resinous compounds as defined
above, photo-initiators, and optionally diluents as
defined above and other components can be used for a
variety of applications, for example: primings on wood;
clear and coloured lacquers on wood, chip plate, board
plate, paper, steel, tin plate; printing inks for paper
(resin about 5,000 poise, reduced to 1,000~2,000 poise
- at 25C by diluent) and plastic sheet (resin about 500 poise,
25 reduced to about 100 poise at 25C by diluent). They can be
applied to the substrate by methods known in the art, and
.
, .
~ '
the treated substrate is passed at high speed under a source of W radiation,
usually a mercury lamp, optionally containing also a source of I.R. radiation.
The compositions are preferably free from volatile solvents which do not poly-
merize; however, plasticizing non-volatile components may be present.
Compositions containing resinous compounds as defined above,
optionally diluents and other components (without photo-initiator~ can also
be cured by electron beam radiation.
The invention is illustrated by examples. Parts and percen-
tages therein are by weight, unless otherwise indicated. Examples 1 - 20
demonstrate preparation of resinous compounds with Or without reactive dilu-
ents (all preparations carried out under nitrogen); examples 21 and 22 demon-
strate evaluation results. "CARDURA" E is a glycidyl ester of branched mono-
carboxylic acids with 9 - 11 carbon atoms, "EPIKOTE" 1001 is a polyglycidyl
polyether of 2,2-bis(4-hydroxyphenyl~propane having 2 free hydroxy groups per
molecule. "EPIKOTE" 828 is a polyglycidyl ether of 2,2-bis(4-hydroxyphenyl~-
propane having an epoxy equivalent weight of 180 - 200. "VeoVa" 10 is a
- vinyl ester of branched monocarboxylic acids having 10 carbon atoms per
molecule. "CARDURA", "EPIKOTE" and "VeoVa" are trade marks.
,
.' ,
~ . :
.~ .
-14-
~w
~G~
- 15 -
The adduct of "CARDURA" E and acrylic acid used
in the examples 1-19 (abbreviated ACE adduct) was prepared
as follows:
A mixture of "CARDURA" E (1235 g; 5 epoxy equivalents),
acrylic acid (360.5 g; 5 mol), triphenyl phosphine (0.5 g)
and hydroquinone (4.o g) was heated with stirring to 120C.
Heating was discontinued and the temperature was allowed to
rise by means of the heat of reaction to 140C, where it
was stabilized by intermittent cooling and heating. After
an epoxy equivalent weight of 50,000 was reached (indicating
; that the reaction was more than 99% complete) the product
was dumped and allowed to cool down. The cooled ACE
adduct was a clear, light yellow liquid of low viscosity.
Determination of active hydrogen gave a value of 345 milli-
15 equivalents per 100 g, corresponding to a hydroxyl equivalent
; weight of 289. 5. In Example 20 a similar ACE adduct having
a hydroxy equivalent weight of 314 was used (ACE adduct II).
EXAMPLE 1
A mixture of hexamethylene diisocyanate (433 g; 2.56 mole),
20 dibutyl tin dilaurate (1.5 g) and hydroquinone (o.6 g) was
heated with stirring to 70C. In 6 hours a solution of ACE
adduct (743 g; 2.56 hydroxy equivalents)in styrene (394 g)
was gradually added with stirring while maintaining the
reaction temperature at 70C. A few minutes after completion
25 of the addition the isocyanate equivalent weight was 650.
Then a mixture of trimethylol propane (110 g), styrene
(37 g), dibutyl tin dilaurate (1.64 g) and hydroquinone (o.6 g)
'
:
:
:, :
,
~`J~
- 16 -
was added. The reaction temperature was kept at 70c
until the isocyanate equlvalent weight was 40,000
(98% conversion). The cooled resinous product was
a clear, lightly coloured viscous liquid.
5 EXAMPLE 2
Isophorone diisocyanate (167 g; 0.75 mole), ACE
adduct (217 g; 0.75 hydroxy equivalent), dibutyl tin
dilaurate (0.2 g), "VeoVa" 10 (96 g)~ and hydroquinone
(o.8 g) were mixed with stirring; the temperature
was allowed to rise to 40C by means of the heat of
reaction, and kept there until the isocyanate equivalent
weight was 631. Then trimethylol propane (33.6 g), dibutyl
tin dilaurate (0.1 g) and "VeoVa" 10 (8.4 g) were added;
the mixture was heated to 70C and maintained at that
~ 15 temperature until the isocyanate equivalent weight
;~ was approximately 5, ooo . The cooled resinous product
was a clear, colourless highly viscous liquid.
- EXAMPLE 3
Trimethylol propane (115 g; 2.56 hydroxy equivalents)
20 was added to a mixture of hexamethylene diisocyanate
(433 g; 2.56 mole), styrene (350 g) and dibutyl tin
dilaurate (1.5 g) with stirring; the temperature was
raised to soc, and maintained there until the mixture
became homogeneous. ThenACE adduct (740 g) and dibutyl
25 tin dilaurate (1.5 g) were added slowly (4 hrs) and
the temperature was allowed to rise to 70C where it
~0~4~
- 17 -
was kept until the isocyanate equivalent weight was
51,000. The cooled resin was a clear, colourless,
highly viscous liquid.
EXAMPLE 4
Example 1 was repeated with the exception that
-~ the trimethylolpropane was replaced by an equivalent
amount of triethanolamine. The cooled resin was
a clear yellow viscous liquid.
EXAMPLE 5
Example 1 was repeated, except that the trimethylol-
propane was replaced by an equivalent amount of a trimethylol-
propane-ethylene oxide adduct containing 14 mole ethylene
oxide per mole trimethylolpropane.
EXAMPLE 6
Example 1 was repeated, except that the trimethylolpropane
was replaced by an equivalent amount (based on hydroxyl)
of "EPIKOTE" 1001.
EXAMPLE 7
Example 1 was repeated, except that the trimethylolpropane
was replaced by an equivalent amount (based on hydroxyl)
of the diacrylate of "EPIKOTE" 828.
EXAMPLE 8
Example 1 was repeated, except that the hexamethylene
diisocyanate was replaced by an equivalent amount (based on
isocyanate) of isophorone diisocyanate.
, .
~ ' ' '' ~ '. , ' ' ' .
.
- . . . .
: :
~G~
- 18 -
EXAMPLE 9
Example 1 was repeated, except that the hexamethylene
diisocyanate was replaced by an equivalent amount (based
. on isocyanate) of trimethylhexamethylene diisocyanate.
- 5 EXAMPLE 10
Example 1 was repeated, except that the styrene was
replaced by the same weight of 2-ethylhexyl acrylate.
EXAMPLE 11 ~.
Example 1 was repeated, except that the styrene was
~10 omitted completely.
- EXAMPLE 12
: Example 11 was repeated, except that the trimethylol-
propane was replaced by an equivalent amount (based on
;hydroxyl) of the diacrylate of "EPIKOTE" 828.
EXAMPLE 13
Example 3 was repeated, except that the hexamethylene
diisocyanate was replaced by an equivalent amount (based
on isocyanate) of isophorone diisocyanate.
EXAMPLE 14
Example 3 was repeated, except that the styrene was
replaced by the same weight of "VeoVa" 10.
EXAMPLE 15
Example 3 was repeated, except that the unsaturated
solvent (styrene) was completely omitted.
EXAMPLE 16
Example 3 was repeated, except that the trimethylolpropane
was replaced by an equivalent amount (based on hydroxyl) of
triethanolamine.
6 ~q ~ ~
" 19
.. :
EXAMPLE 17
--- Example 2 was repeated, except that "VeoVa" 10 was
omitted. The resulting resin was a clear, highly viscous
mass.
EXAMPLE 18
Example 1 was repeated, except that hexamethylene diisocy-
anate was replaced by an equivalent amount of 2.4-toluylene
diisocyanate and the styrene was omitted. The product
was a yellow brittle solid.
~ 10 EXAMPLE 19
- Example 2 was repeated, except that trimethylolpropane
was replaced by an equivalent amountofatriol derived
from glycerol and propylene oxide having an average
molecular weight of 300.
EXAMPLE 20
Isophorone diisocyanate (167 g; 0.75 mole), ACE
adduct II (235.5 g; 0.75 hydroxy equivalents),dibutyl
tin d~aurate (0.2 g) and hydroquinone (o.8 g) were
mixed with stirring. The temperature was allowed to Fise
to 40~C by means of the reaction heat, and kept there
until the isocyanate equivalent weight was 525 Then
sorbitol (45.5 g; 0.25 mole) and dibutyl tin dilaurate
(0.1 g) were added, the mixture was heated to 100C
and maintained at that temperature until the isocyanate
equivalent weight was approximately 5,000. The cooled
resinous product was a clear,brittle material.
.; .
. - :- - . :
'. , ,
~`
;4~
~ - 20 -
.
EXAMPLE 21
- Evaluation of products of Examples 1-8 and 10-16
The products of these Examples were evaluated as
coatings (approximately 15 microns thick) on paper by
determination of the speed of cure when irradiated with
an UV lamp. Benzoin ethyl ether (1 %w) was used as a
photo-initiator, and reactive diluents were added to
the products of Examples 11, 12 and 15 as indicated
in Table I.
All irradiations were carried out using two
Philips HOK-5 5000 Watt medium pressure, air-cooled
mercury vapour lamps with a flux of 80 Watt/cm.
The armatures both contained elliptical reflectors.
The lamps are mounted at one of the foci. A conveyor
belt of variable speed was used to control the exposure
time. The lamps were so positioned that the object being
irradiated passes through the second focus - a distance
of 12 cm from the lamp.
; Evaluation results are collected in the following
Table, as number of passes under the UV lamp as belt
speed given until the coating was dry to the touch
(tested with cotton wool).
. ~
- 21 -
Table I
Product of Reactive Belt speed Number of passes
diluent(m/min)
- added
Example 1 - 30 8
~' 2 - 120
" 3 - 30 9
" 4 - 30 2
" 5 - 3 3
" 6 - 30 10
" 7 - 30 3
" 8 - 30 2
" 10 - 30 2
" 11 ACE(30 %w) 30 5
" 12 ACE(20 %w) 50
" 13 - 3 5
" 14 - 50
; " 15 2-ethyl 30 2
hexyl acry-
late (20 %w)
16 - 3 2
========_==================== :
%w is weight percent on product of the Examples.
EXAMPLE 22
Evaluation of products of Examples 17-20
All systems in this Example contained benZ~n/ethyl ether
(2.5 %w) as photoinitiator. Drying speeds (touch-dry)
were determined as described in Example 21. Further, the
resinous products were evaluated as coatings.
:, :
.: .
.
1(3
~; - 22 -
: (40-50 ~um thick clear films on phosphatized steel
panels (Bonder 97, "Bonder" is a registered trade
name).
The coated panels were cured by passing them twice
- 5 at a belt speed of 30 m/min through the UV installation
described in Example 21. Properties determined were:
Konig pendulum hardness, reverse impact resistance,
adhesion (cross cut + tape test), and solvent resistance
(scrubbing with a methyl ethyl k~.tone (MEK) - moistened
cloth until the coating could be removed by scratching
with the fingernail).
Results are collected in Table II.
~ .
:
:
:
'~ .
~ 23
~Table II
Product Reactive Touch-dry Film Properties
of Diluent after (after 2 passes at 30 m/min)
Example added *)
(%w)Belt No. Hard- Reverse Adhes- MEK
speed of ness Impact ion**~ resi$~
m/min passes (K8nig) (cm kg) (No. of
rubs)
17 (VeoVa (20)+ 120 1 78 4.5 2 45
17 ¦HEA (25) 120 1158 3.3 4 35
18 (VeoVa(20)+90 160 2.2 2 25
18 HEA (25) 120 1155 4.5 4 50 :
19 VA (5) 30 250***1 13.5***~ 5***2 10***~
-.............. 20 HEA (25) 120 1 144 4.5 3 45
` 20 ~ 120 1 78 6. 2 45 : -
.
. *) VA: vinylacetate, HEA: 2-hydroxyethyl aoylate,
TMPTA: trimethylolpropane triacrylate
HDDA: 1.6-hexan.ediol diacrylate
.~
,
**) 5: excellent adhesion
0: no adhesion
***) after 5 passes at 30 m/min.
