U.S. patent application number 09/861433 was filed with the patent office on 2002-04-11 for alkylphenylbisacylphosphine oxides and photoinitiator mixtures.
Invention is credited to Kohler, Manfred, Leppard, David George, Valet, Andreas.
Application Number | 20020042022 09/861433 |
Document ID | / |
Family ID | 27172208 |
Filed Date | 2002-04-11 |
United States Patent
Application |
20020042022 |
Kind Code |
A1 |
Leppard, David George ; et
al. |
April 11, 2002 |
Alkylphenylbisacylphosphine oxides and photoinitiator mixtures
Abstract
Compounds of the formula I 1 in which R.sub.1 is
C.sub.1-C.sub.4alkyl, R.sub.2 is hydrogen, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4alkoxy and R.sub.3, R.sub.4, R.sub.6 and R.sub.7
independently of one another are hydrogen, halogen,
C.sub.1-C.sub.20alkyl, cyclopentyl, cyclohexyl,
C.sub.2-C.sub.12alkenyl, C.sub.2-C.sub.18alkyl which is interrupted
by one or more oxygen atoms, or are phenyl-substituted
C.sub.1-C.sub.4alkyl, or are phenyl which is unsubstituted or is
mono- or disubstituted by C.sub.1-C.sub.4alkyl and/or
C.sub.1-C.sub.4alkoxy, with the provisos that at least one of the
radicals R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 is other
than hydrogen and that, if R.sub.1and R.sub.2 are methyl, R.sub.3
and R.sub.6 are not methyl, and mixtures of such compounds with
.alpha.-hydroxy ketones, benzophenones and .alpha.-amino ketones,
are suitable as photoinitiators.
Inventors: |
Leppard, David George;
(Marly, CH) ; Kohler, Manfred; (Freiburg, DE)
; Valet, Andreas; (Binzen, DE) |
Correspondence
Address: |
CIBA SPECIALTY CHEMICALS CORPORATION
PATENT DEPARTMENT
540 WHITE PLAINS RD
P O BOX 2005
TARRYTOWN
NY
10591-9005
US
|
Family ID: |
27172208 |
Appl. No.: |
09/861433 |
Filed: |
May 18, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09861433 |
May 18, 2001 |
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09009827 |
Jan 20, 1998 |
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09009827 |
Jan 20, 1998 |
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08806498 |
Feb 26, 1997 |
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6020528 |
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Current U.S.
Class: |
430/281.1 ;
430/326; 430/913; 430/916; 430/919; 522/10; 522/28; 522/8 |
Current CPC
Class: |
C08F 2/50 20130101; G03F
7/029 20130101; Y10S 522/908 20130101; B33Y 70/00 20141201; C07F
9/5337 20130101; C09D 4/00 20130101 |
Class at
Publication: |
430/281.1 ;
522/10; 522/8; 522/28; 430/326; 430/913; 430/916; 430/919 |
International
Class: |
G03F 007/027 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 4, 1996 |
CH |
558/96 |
Claims
What is claimed is:
1. A compound of the formula I 24in which R.sub.1 is
C.sub.1-C.sub.4alkyl, R.sub.2 is hydrogen, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4alkoxy, and R.sub.3, R.sub.4, R.sub.5, R.sub.6 and
R.sub.7 independently of one another are hydrogen, halogen,
C.sub.1-C.sub.20 alkyl, cyclopentyl, cyclohexyl,
C.sub.2-C.sub.12alkenyl, C.sub.2-C.sub.18alkyl which is interrupted
by one or more oxygen atoms, or are phenyl-substituted
C.sub.1-C.sub.4alkyl, or are phenyl which is unsubstituted or is
mono- or disubstituted by C.sub.1-C.sub.4alkyl and/or
C.sub.1-C.sub.4alkoxy, with the provisos that at least one of the
radicals R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 is other
than hydrogen and that, if R.sub.1 and R.sub.2 are methyl, R.sub.3
and R.sub.6 are not methyl.
2. A compound according to claim 1, in which R.sub.3, R.sub.4,
R.sub.5, R.sub.6 and R.sub.7 are hydrogen, C.sub.1-C.sub.8-alkyl,
phenyl, allyl, benzyl, cyclohexyl or chlorine.
3. A compound according to claim 1, in which R.sub.3, R.sub.4 and
R.sub.5 are hydrogen, C.sub.1-C.sub.4alkyl or phenyl.
4. A compound according to claim 1, in which R.sub.1 is methyl.
5. A compound according to claim 1, in which R.sub.1 and R.sub.2
are the same.
6. A photoinitiator mixture comprising at least one compound of the
formula (Ia) 25in which R.sub.1 is C.sub.1-C.sub.4alkyl; R.sub.2 is
hydrogen, C.sub.1-C.sub.4alkyl or C.sub.1-C.sub.4alkoxy, and
R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 independently of one
another are hydrogen, halogen, C.sub.1-C.sub.20 alkyl, cyclopentyl,
cyclohexyl, C.sub.2-C.sub.12alkenyl, C.sub.2-C.sub.18alkyl which is
interrupted by one or more oxygen atoms, or are phenyl-substituted
C.sub.1-C.sub.4alkyl, or are phenyl which is unsubstituted or is
mono- or disubstituted by C.sub.1-C.sub.4alkyl and/or
C.sub.1-C.sub.4alkoxy; and at least one compound of the formula
(II) 26in which R.sub.8 is hydrogen, C.sub.1-C.sub.18alkyl,
C.sub.1-C.sub.18alkoxy, --OCH.sub.2CH.sub.2--OR.su- b.12, a group
27 or a group 28 in which I is a number from 2 to 10 and A is a
radical 29R.sub.9 and R.sub.10 independently of one another are
hydrogen, C.sub.1-C.sub.6alkyl, phenyl, C.sub.1-C.sub.16-alkoxy,
OSiR.sub.13R.sub.14R.sub.14a or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.s- ub.16alkyl, in which q
is a number from 1 to 20, or R.sub.9 and R.sub.10, together with
the carbon atom to which they are attached, form a cyclohexyl ring;
R.sub.11 is hydroxyl, C.sub.1-C.sub.16alkoxy or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.sub.16alkyl; Where R.sub.9,
R.sub.10 and R.sub.11 are not all simultaneously
C.sub.1-C.sub.16alkoxy or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.sub.16alkyl, R.sub.12 is
hydrogen, C.sub.1-C.sub.8alkyl, 30and R.sub.13 R.sub.14a and
R.sub.14 independently of one another are C.sub.1-C.sub.4alkyl or
phenyl; and/or at least one compound of the formula (III) 31in
which R.sub.15, R.sub.15a, R.sub.16 and R.sub.17 independently of
one another are hydrogen, methyl, phenyl, methoxy, -COOH,
unsubstituted or C.sub.1-C.sub.4alkyl-substituted phenyl, or a
group --OCH.sub.2CH.sub.2OR.sub.12 or --SCH.sub.2CH.sub.2OR.sub.12
in which R.sub.12 is as defined for formula II; and/or at least one
compound of the formula (IV) 32in which R.sub.18 is hydrogen,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
C.sub.1-C.sub.4alkylthio, halogen or a group N(R.sub.22).sub.2;
R.sub.19 is as defined for R.sub.18 or is the group 33 in which
case the radical R.sub.18 from the formula IV and the radical
R.sub.18 of this group (IVa) together are a direct bond, and the
other radicals are as defined below; R.sub.20 is
C.sub.1-C.sub.8alkyl; R.sub.21 is hydrogen, --CH.dbd.CHR.sub.24, or
phenyl which is unsubstituted or is substituted one to three times
by C.sub.1-C.sub.12alkyl, C.sub.1-C.sub.4alkoxy or halogen; or
R.sub.20 and R.sub.21, together with the carbon atom to which they
are attached, form a cyclohexyl ring; R.sub.22 and R.sub.23
independently of one another are C.sub.1-C.sub.4alkyl, or R.sub.22
and R.sub.23, together with the nitrogen atom to which they are
attached, form a five- or six-membered saturated or unsaturated
ring which can be interrupted by --O--, --NH-- or --N(CH.sub.3)--,
R.sub.24 is hydrogen or C.sub.1-C.sub.4alkyl; and R.sub.25 is
hydrogen or C.sub.1-C.sub.12alkyl.
7. A photoinitiator mixture according to claim 6, comprising
compounds of the formula Ia and compounds of the formula II in
which R.sub.8 is hydrogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, --OCH.sub.2CH.sub.2OR.sub.12, a group 34 or
a group 35 R.sub.9 and R.sub.10 independently of one another are
hydrogen, C.sub.1-C.sub.3alkyl, phenyl, C.sub.1-C.sub.12alkoxy, or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-- C.sub.8alkyl, in which q is
a number from 1 to 10, or R.sub.9 and R.sub.10, together with the
carbon atom to which they are attached, form a cyclohexyl ring;
R.sub.11 is hydroxyl, C.sub.1-C.sub.4alkoxy or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.sub.8alkyl; and/or
compounds of the formula III, and/or compounds of the formula IV in
which R.sub.18 is hydrogen or methoxy; R.sub.19 is methoxy,
methylthio, morpholino or a group of the formula IVa; R.sub.20 is
methyl or ethyl; R.sub.22 and R.sub.23 are the same and are methyl
or, together with the nitrogen atom to which they are attached,
form a five- or six-membered saturated ring which can be
interrupted by --O--; and R.sub.25 is hydrogen or
C.sub.1-C.sub.8alkyl.
8. A photoinitiator mixture according to claim 6, in which the
compound of the formula III is benzophenone, 2,4,6-trimethylphenyl
phenyl ketone,4-methylphenyl phenyl ketone,
3-methyl-4-methoxyphenyl 3-methylphenyl
ketone,4-(4-methylphenylthio)phenyl phenyl ketone, 2-carboxyphenyl
phenyl ketone or 4-(2-hydroxyethoxy)phenyl phenyl ketone; the
compound of the formula II is 1-benzoyl-1-hydroxy-1-methylethane,
1-benzoylcyclohexanol,
4-[(2-hydroxyethoxy)benzoyl]-1-hydroxy-1-methyleth- ane,
1-(4-isopropylbenzoyl)-1-hydroxy-1-methylethane or
2,2-dimethoxy-1,2-diphenylethan-1-one; the compound of the formula
IV is
1-(3,4-dimethoxybenzoyl)-1-benzyl-1-morpholinopropane,1-(4-methylthiobenz-
oyl)-1-methyl-1-morpholinoethane,
1-(4-morpholinobenzoyl)-1-benzyl-1-dimet- hylaminopropane or
3,6-bis(2-methyl-2-morpholinopropan-1-one)-9-octylcarba- zole; and
the compound of the formula Ia is bis(2,4,6-trimethylbenzoyl)-2,-
5-diisopropylphenylphosphine oxide,
bis[2,6-dimethyl-4(2-methylpropyl)benz- oyl]phenylphosphine oxide,
bis(2,6-dimethylbenzoyl)phenylphosphine oxide,
bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide or
bis(2,4,6-trimethylbenzoyl)-2,5-dimethylphenylphosphine oxide.
9. A photoinitiator mixture according to claim 6 comprising at
least one compound of the formula Ia and two compounds of the
formula II.
10. A photoinitiator mixture comprising 25%
bis(2,4,6-trimethylbenzoyl) phenylphosphineoxide and 75%
1-benzoylcyclohexanol.
11. A photopolymerizable composition comprising (a) at least one
ethylenically unsaturated photopolymerizable compound and (b) as
photoinitiator, at least one compound of the formula I according to
claim 1 or a photoinitiator mixture according to claim 6.
12. A photopolymerizable composition according to claim 11,
comprising as photoinitiator at least one compound of the formula I
according to claim 1 or a photoinitiator mixture according to claim
6, and a UV absorber from the class of the
hydroxyphenyl-s-triazines and/or hydroxyphenylbenzotriazoles and/or
sterically hindered amines based on
2,2,6,6-tetramethylpiperidines.
13. A process for the photopolymerization of compounds containing
ethylenically unsaturated double bonds, which comprises irradiating
a composition according to claim 11 with light in the range from
200 to 600 nm.
14. A process according to claim 13 for producing coating
materials, printing inks, printing plates, dental compositions,
resist materials and as image-recording material, especially for
holographic recordings.
15. A coated substrate which is coated on at least one surface with
a composition according to claim 11.
16. A process for the photographic production of relief images, in
which a coated substrate according to claim 15 is subjected to
imagewise exposure and then the unexposed areas are removed with a
solvent.
Description
[0001] The invention relates to alkylphenylbisacylphosphine oxides
and to specific mixtures of bisacylphosphine oxide compounds with
other photoinitiators.
[0002] Bisacylphosphine oxide compounds are known as
photoinitiators from EP-A-184095, for example.
Alkylbisacylphosphine oxides and also mixtures of these compounds
with .alpha.-hydroxy ketones or benzophenone compounds are
disclosed in GB-A-2259704. EP-A-446175 describes mixtures of three
components, namely mono- or bisacylphosphine oxide,
.alpha.-hydroxyketone and benzophenone.
[0003] In industry there is a need for effective photoinitiators
and photoinitiator mixtures which are capable of curing
photopolymerizable compositions efficiently and without extreme
yellowing phenomena.
[0004] It has now been found that compounds of the formula I 2
[0005] in which
[0006] R.sub.1 is C.sub.1-C.sub.4alkyl,
[0007] R.sub.2 is hydrogen, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4alkoxy and
[0008] R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 independently
of one another are hydrogen, halogen, C.sub.1-C.sub.20alkyl,
cyclopentyl, cyclohexyl, C.sub.2-C.sub.12alkenyl,
C.sub.2-C.sub.18alkyl which is interrupted by one or more oxygen
atoms, or are phenyl-substituted C.sub.1-C.sub.4alkyl, or are
phenyl which is unsubstituted or is mono- or disubstituted by
C.sub.1-C.sub.4alkyl and/or C.sub.1-C.sub.4alkoxy, with the
provisos that at least one of the radicals R.sub.3, R.sub.4,
R.sub.5, R.sub.6 and R.sub.7 is other than hydrogen and that, if
R.sub.1 and R.sub.2 are methyl, R.sub.3 and R.sub.6 are not methyl,
are suitable as very good photoinitiators.
[0009] It has also been found that the photoinitiators of the
formula 1a can be combined with compounds of the formula II, III
and/or IV to give initiator mixtures (blends) having good curing
properties, especially in respect of the required surface curing
and through-curing of polymerizable compositions. The cured
compositions, moreover, exhibit highly advantageous properties in
the context of yellowing. This application therefore provides a
photoinitiator mixture comprising at least one compound of the
formula (1) 3
[0010] in which
[0011] R.sub.1 is C.sub.1-C.sub.4alkyl;
[0012] R.sub.2 is hydrogen, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4alkoxy, and
[0013] R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 independently
of one another are hydrogen, halogen, C.sub.1-C.sub.20alkyl,
cyclopentyl, cyclohexyl, C.sub.2-C.sub.12alkenyl,
C.sub.2-C.sub.18alkyl which is interrupted by one or more oxygen
atoms, or are phenyl-substituted C.sub.1-C.sub.4alkyl, or are
phenyl which is unsubstituted or is mono- or disubstituted by
C.sub.1-C.sub.4alkyl and/or C.sub.1-C.sub.4alkoxy; and at least one
compound of the formula (II) 4
[0014] in which
[0015] R.sub.8 is hydrogen, C.sub.1-C.sub.18alkyl,
C.sub.1-C.sub.18alkoxy, --OCH.sub.2CH.sub.2--OR.sub.12, a group
5
[0016] or a
[0017] group 6
[0018] in which I is a number from 2 to 10 and A is a radical 7
[0019] R.sub.9 and R.sub.10 independently of one another are
hydrogen, C.sub.1-C.sub.6alkyl, phenyl, C.sub.1-C.sub.16-alkoxy,
OSiR.sub.13R.sub.14R.sub.14a or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.s- ub.16alkyl, in which q
is a number from 1 to 20, or R.sub.9 and R.sub.10, together with
the carbon atom to which they are attached, form a cyclohexyl
ring;
[0020] R.sub.11 is hydroxyl, C.sub.1-C.sub.16alkoxy or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.sub.16alkyl; where R.sub.9,
R.sub.10 and R.sub.11 are not all simultaneously
C.sub.1-C.sub.16alkoxy or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.sub.16alkyl,
[0021] R.sub.12 is hydrogen, C.sub.1-C.sub.8alkyl, 8
[0022] and
[0023] R.sub.13, R.sub.14a and R.sub.14 independently of one
another are C.sub.1-C.sub.4alkyl or phenyl; and/or at least one
compound of the formula (III) 9
[0024] in which
[0025] R.sub.15, R.sub.15a, R.sub.16 and R.sub.17 independently of
one another are hydrogen, methyl, phenyl, methoxy, --COOH,
unsubstituted or C.sub.1-C.sub.4alkyl-substituted phenyl, or a
group --OCH.sub.2CH.sub.2OR.sub.12 or --SCH.sub.2CH.sub.2OR.sub.12
in which R.sub.12 is as defined for formula II; and/or at least one
compound of the formula (IV) 10
[0026] in which
[0027] R.sub.18 is hydrogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4alkylthio, halogen or a group
N(R.sub.22).sub.2;
[0028] R.sub.19 is as defined for R.sub.18 or is the group 11
[0029] in which
[0030] case the radical R.sub.18 from the formula IV and the
radical R.sub.18 of this group ( IV) together are a direct bond,
and the other radicals are as defined below;
[0031] R.sub.20 is C.sub.1-C.sub.8alkyl;
[0032] R.sub.21 is hydrogen, --CH.dbd.CHR.sub.24, or phenyl which
is unsubstituted or is substituted one to three times by
C.sub.1-C.sub.12alkyl, C.sub.1-C.sub.4alkoxy or halogen;
[0033] or R.sub.20 and R.sub.21, together with the carbon atom to
which they are attached, form a cyclohexyl ring;
[0034] R.sub.22 and R.sub.23 independently of one another are
C.sub.1-C.sub.4alkyl, or
[0035] R.sub.22 and R.sub.23, together with the nitrogen atom to
which they are attached, form a five- or six-membered saturated or
unsaturated ring which can be interrupted by --O--, --NH-- or
--N(CH.sub.3)--,
[0036] R.sub.24 is hydrogen or C.sub.1-C.sub.4alkyl; and
[0037] R.sub.25 is hydrogen or C.sub.1-C.sub.12alkyl.
[0038] C.sub.1-C.sub.20 alkyl can be linear or branched and is, for
example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,
sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, heptyl, octyl,
nonyl, decyl, dodecyl, octadecyl or eicosyl. Preference is given to
C.sub.1-C.sub.18alkyl, e.g. C.sub.1-C.sub.12- or
C.sub.1-C.sub.8alkyl, especially C.sub.1-C.sub.4alkyl.
[0039] C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.6alkyl and
C.sub.1-C.sub.4alkyl can have the same meanings as given above up
to the corresponding number of carbon atoms.
[0040] C.sub.2-C.sub.18alkyl interrupted by one or more oxygen
atoms is, for example, interrupted by 1-5, e.g. 1-3 or 1 or 2 times
by --O--. This produces structural units such as
--O(CH.sub.2).sub.2OH, --O(CH.sub.2).sub.2OCH.sub.3,
--O(CH.sub.2CH.sub.2O).sub.2CH.sub.2CH.sub.- 3,
--CH.sub.2--O--CH.sub.3, --CH.sub.2CH.sub.2--O--CH.sub.2CH.sub.3,
--[CH.sub.2CH.sub.2O].sub.y--CH.sub.3, where y=1-5,
--(CH.sub.2CH.sub.2O).sub.5CH.sub.2CH.sub.3,
--CH.sub.2--CH(CH.sub.3)--O-- -CH.sub.2--CH.sub.2CH.sub.3 or
--CH.sub.2--(CH.sub.3)--O--CH.sub.2--CH.sub- .3.
[0041] The radical
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.sub.16alkyl represents 1 to
20 successive ethylene oxide units whose chain ends in a
C.sub.1-C.sub.16alkyl. q is preferably q 1 to 10, e.g. 1 to 8,
especially 1 to 6. The chain of ethylene oxide units ends in a
C.sub.1-C.sub.12alkyl, e.g. C.sub.1-C.sub.8alkyl, in particular in
a C.sub.1-C.sub.4alkyl. Here C.sub.1-C.sub.16alkyl can have the
meanings given above up to the corresponding number of carbon
atoms.
[0042] C.sub.2-C.sub.12alkenyl can be linear or branched and there
may be more than one unsaturated bond in the molecule. Examples are
vinyl, allyl, methylvinyl, butenyl, pentenyl, hexenyl, heptenyl,
octenyl, nonenyl, decenyl, dodecenyl. C.sub.1-C.sub.8alkoxy can be
linear or branched and is, for example, methoxy, ethoxy, propoxy,
isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentoxy,
isopentoxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy,
dodecyloxy or octadecyloxy. Further examples are
C.sub.1-C.sub.12alkoxy or C.sub.1-C.sub.8alkoxy, especially
C.sub.1-C.sub.4alkoxy. C.sub.1-C.sub.6alkoxy and
C.sub.1-C.sub.4alkoxy can have the same meanings as given above up
to the corresponding number of carbon atoms.
[0043] C.sub.1-C.sub.4alkylthio can be linear or branched and is,
for example, methylthio, ethylthio, propylthio, isopropylthio,
butylthio or tert-butylthio, especially methylthio.
[0044] Phenyl-substituted C.sub.1-C.sub.4alkyl is, for example,
benzyl, 2-phenylethyl, 3-phenylpropyl, .alpha.-methylbenzyl or
.alpha.,.alpha.-dimethylbenzyl, especially benzyl.
[0045] Substituted phenyl is substituted from one to five times,
for example once, twice or three times, especially once or twice,
on the phenyl ring. The pattern of substitution on the phenyl ring
is, for example, 2-, 3-,4-,5-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-, 2,4,6-
or 3,4,5-. C.sub.1-C.sub.4alkyl and C.sub.1-C.sub.4alkoxy
substituents can have the meanings given above. Examples of
substituted phenyl are tolyl, xylyl,4-methoxyphenyl, 2,4- and
2,5-dimethoxyphenyl, ethylphenyl, and 4-alkoxy-2-methylphenyl.
[0046] Halogen is, for example, chlorine, bromine or iodine,
especially chlorine.
[0047] If R.sub.19 is the group 12
[0048] where the radical R.sub.18 from the formula IV and the
radical R.sub.18 of this group together are a direct bond, then the
result is structures of the formula IV 13
[0049] If R.sub.22 and R.sub.23, together with the nitrogen atom to
which they are attached, form a ring which can additionally be
interrupted by --O--, --NH-- or --N(CH.sub.3)--, then the ring
formed is, for example, a morpholino, piperidino or
methylpiperidino ring.
[0050] The novel compounds of the formula I (and 1) can be
prepared, for example, by double acylation of a primary phosphine
(V) with at least 2 equivalents of an acid chloride (VI) in the
presence of at least two equivalents of a base and subsequent
oxidation of the resulting diacylphosphine (VII) in accordance with
the equations: 14
[0051] R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and
R.sub.7 are as defined in claim 8.
[0052] Examples of suitable bases are tertiary amines, pyridine,
alkali metals, lithium diisopropylamide, butyllithium, alkaline
earth metal carbonates, alkali metal alcoholates and alkali metal
hydrides. The first reaction stage takes place preferably in
solution. Particularly suitable solvents are hydrocarbons, such as
alkanes and alkane mixtures, cyclohexane, benzene, toluene and
xylene. The reaction is carried out at various temperatures
depending on the solvent and starting materials used. In the case
of the use of bases such as lithium diisopropylamide or
butyllithium, it is expedient to work, for example, at from -40 to
0.degree. C.
[0053] Reactions using tertiary amines, alkali metals or alkali
metal hydrides as bases are expediently carried out, for example,
at from 10 to 120.degree. C., preferably from 20 to 80.degree. C.
After the base chloride formed has been separated off, the
phosphine (VII) can be isolated by evaporative concentration. The
crude reaction product can be used further without purification or
else can be purified by means, for example, of crystallization.
However, the second reaction stage can also be carried out without
isolating (VII), using the solution of the crude product.
[0054] Particularly suitable oxidizing agents for the second stage
in the preparation of the oxides are hydrogen peroxide and organic
peroxy compounds, examples being peracetic acid, air and pure
oxygen.
[0055] The reaction products can be purified by conventional
methods, for example by crystallization or chromatography.
[0056] The phosphines of the formula (V) can be prepared, for
example, by reducing the corresponding dichlorides (VII),
phosphonic esters (IX) or phosphonous esters (X): 15
[0057] R' is, for example, methyl or ethyl.
[0058] Reductions are usually carried out with LiAIH.sub.4;
SiHCl.sub.3; Ph.sub.2SiH.sub.2; a) LiH b) H.sub.2O; a)
Li/tetrahydrofuran b) H.sub.2O or a) Na/toluene b) H.sub.2O.
[0059] Hydrogenation using LiAIH.sub.4, for example, can also be
found in Helv. Chim. Acta 1966, No. 96, page 842.
[0060] The dichlorophosphine compounds of the formula VIII can be
obtained, for example, by reacting a corresponding aromatic
compound with phosphorus trichloride and aluminium chloride. 16
[0061] The dichlorides (VIII) can also be obtained, for example, by
Grignard reaction of the corresponding brominated aromatic
compounds (XI) with PCl.sub.3 (cf. e.g. Heiv.Chim. Acta 1952, No
35, page 1412): 17
[0062] R.sub.1, R.sub.2 R.sub.3, R.sub.4, R.sub.5, R.sub.6 and
R.sub.7 are as defined in claim 8.
[0063] The diesters of formula (IX) can be prepared, for example,
by reacting the brominated aromatic compounds (XI) with a
trisphosphorous ester (XII). Reactions of this kind are described,
for example in DE-C-1810431. 18
[0064] The phosphonous esters (X) can be obtained, for example by
reacting a phosphorus dichloride (VII) with an alcohol: 19
[0065] The brominated aromatic compounds (XI) are obtained by
prior-art bromination reactions, for example by reacting
alkoxylated aromatic compounds with N-bromosuccinimide or
bromine/acetic acid.
[0066] The acid chlorides of the formula (VI) are prepared by
generally known methods from the prior art.
[0067] The preparation of the compounds of the formulae II and III
is generally known, and some of the compounds are commercially
available. The preparation of oligomeric compounds of the formula
II, for example, is described in EP-A-161 463. A description of the
preparation of the compounds of the formula III can be found for
example in EP-A-209 831. The preparation of compounds of the
formula IV is given, for example, in EP-A-3002 or EP-A-284 561.
Furthermore, some compounds of the formula IV are available
commercially.
[0068] Examples of novel compounds are:
[0069] Bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine
oxide;
[0070] bis(2,4,6-trimethylbenzoyl)-2-methyl phenylphosphine
oxide;
[0071] bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine
oxide;
[0072] bis(2,4,6-trimethylbenzoyl)-2,5-diethylphenylphosphine
oxide;
[0073]
bis(2,4,6-trimethylbenzoyl)-2,3,5,6-tetramethylphenylphosphine
oxide.
[0074] The novel photoinitiator mixtures are prepared, for example,
by mixing, milling, melting or dissolving the individual
components, it being possible to use liquid components as solvents
for the respective combination partners. It is also possible,
however, to combine the components in an inert solvent.
[0075] The photoinitiator mixtures comprise, for example, 2-90%,
e.g.5-50%,5-40%, especially 5-25%, of compounds of formula Ia and
98-50%, e.g. 95-60%, especially 95-75%, of compounds of the formula
II, III and/or IV. Other mixtures which are of interest are those
in which the proportion of compounds of the formula Ia in the
mixture with compounds of the formula II and III and/or IV is from
30 to 70%.
[0076] Preferred examples of compounds of the formula II and III
are 1-benzoylcyclohexanol, 2,2-dimethoxy-1,2-diphenylethan-1-one
and 1-benzoyl-1-hydroxy-1-methylethane.
[0077] Examples of novel photoinitiator mixtures (blends) are
[0078] 5% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 95%
1-benzoyl-1-hydroxy-1-methylethane;
[0079] 5% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 95%
1-benzoylcyclohexanol;
[0080] 25% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 75%
1-benzoylcyclohexanol;
[0081] 25% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 75%
1-benzoyl--hydroxy-1-methylethane;
[0082] 25% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 75%
2,2-dimethoxy-1,2-diphenyiethan-1-one;
[0083] 5% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 95%
2,2-dimethoxy-1,2-diphenylethan-1-one;
[0084] 25% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and
75%4-(2-hydroxyethoxy)benz-oyl-1-hydroxy-1-methylethane;
[0085] 5% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and
95%4-(2-hydroxyethoxy)benz-oyl-1-hydroxy-1-methylethane;
[0086] 5%
bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide
and 95% 1-benzoylcyclohexanol;
[0087] 5%
bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide
and 95% 1-benzoyl-1-hydroxy-1-methylethane;
[0088] 25%
bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide
and 75% 1-benzoylcyclohexanol;
[0089] 25%
bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide
and 75% 1-benzoyl-1-hydroxy-1-methylethane;
[0090] 5%
bis(2,4,6-trimethylbenzoyl)-4-tert-butyl-2,6-dimethylphenylphosp-
hine oxide and 95% 1-benzoylcyclohexanol;
[0091] 5%
bis(2,4,6-trimethylbenzoyl)-4-tert-butyl-2,6-dimethylphenylphosp-
hine oxide and 95% 1-benzoyl-1-hydroxy-1-methylethane;
[0092] 25%
bis(2,4,6-trimethylbenzoyl)-4-tert-butyl-2,6-dimethylphenylphos-
phine oxide and 75% 1-benzoylcyclohexanol;
[0093] 25%
bis(2,4,6-trimethylbenzoyl)-4-tert-butyl-2,6-dimethylphenylphos-
phine oxide and 75% 1-benzoyl-1-hydroxy-1-methylethane;
[0094] 5% bis(2,6-dimethylbenzoyl)phenylphosphine oxide and 95%
1-benzoyl-1-hydroxy-1-methylethane;
[0095] 5% bis(2,6-dimethylbenzoyl)phenylphosphine oxide and 95%
1-benzoylcyclohexanol;
[0096] 25% bis(2,6-dimethylbenzoyl)phenylphosphine oxide and 75%
1-benzoyl-1-hydroxy-1-methylethane;
[0097] 25% bis(2,6-dimethylbenzoyl)phenylphosphine oxide and 75%
1-benzoylcyclohexanol;
[0098] 5% bis(2,4,6-trimethylbenzoyl)-2,5-dimethylphenylphosphine
oxide and 95% 1-benzoylcyclohexanol;
[0099] 5% bis(2,4,6-trimethylbenzoyl)-2,5-dimethylphenyl-phosphine
oxide and 95% 1-benzoyl-1-hydroxy-1-methylethane;
[0100] 25% bis(2,4,6-trimethylbenzoyl)-2,5-dimethylphenylphosphine
oxide and 75% 1-benzoylcyclohexanol;
[0101] 25% bis(2,4,6-trimethylbenzoyl)-2,5-dimethylphenylphosphine
oxide and 75% 1-benzoyl-1-hydroxy-1-methylethane;
[0102] 25% bis(2,4,6-trimethylbenzoyl)-2,5-dimethylphenylphosphine
oxide and 75% 2,2-dimethoxy-1,2-diphenylethan-1-one;
[0103] 25%
bis(2,4,6-trimethylbenzoyl)-2,5-dimethylphenylphosphinoxide and 75%
4-(2-hydroxyethoxy)benzoyl- 1-hydroxy-1-methylethane.
[0104] Photoinitiator mixtures of particular interest are those
obtained by dissolving bis(2,4,6-trimethylbenzoyl)phenylphosphine
oxide in a liquid hydroxy ketone compound. More than 2 components,
especially 3, are preferably used in the mixture. The
three-component mixtures are expediently prepared by mixing the
respective constituents and heating the mixture gently, for example
at 50-60.degree. C.
[0105] The invention additionally provides photoinitiator mixtures
comprising at least one compound of the formula Ia and two
compounds of the formula II.
[0106] Preference is given, for example, to 3-component mixtures
comprising
[0107] 25% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide,
[0108] 70% 1-benzoylcyclohexanol and
[0109] 5% 1-benzoyl-1-hydroxy-1-methylethane; or
[0110] 25% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide,
[0111] 60% 1-benzoylcyclohexanol and
[0112] 15% 1-benzoyl-1-hydroxy-1-methylethane; or
[0113] 25% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide,
[0114] 50% 1-benzoylcyclohexanol and
[0115] 25% 1-benzoyl-1-hydroxy-1-methylethane.
[0116] Preference is given to compounds of the formula I in which
R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are hydrogen,
C.sub.1-C.sub.8alkyl, phenyl, allyl, benzyl, cyclohexyl or
chlorine.
[0117] Further advantageous compounds of the formula I and Ia are
those in which .sub.3, R.sub.4 and R.sub.5are hydrogen,
C.sub.1-C.sub.4alkyl, especially methyl, or phenyl.
[0118] Attention is drawn to compounds of the formula I and Ia in
which R.sub.6 and R.sub.7 are hydrogen or C.sub.1-C.sub.4alkyl,
especially methyl.
[0119] Particular preference is given to those compounds of the
formula I and Ia in which R.sub.2 is hydrogen or
C.sub.1-C.sub.4alkyl.
[0120] Preference extends to the compounds of the formula I and Ia
in which R.sub.1 is methyl.
[0121] Preference is likewise given to compounds of the formula I
and Ia in which R.sub.1 and R.sub.2 are the same.
[0122] Also of interest are compounds of the formula I and Ia in
which R.sub.1 and R.sub.2 are C.sub.1-C.sub.4alkyl, especially
methyl.
[0123] In the novel photoinitiator mixtures, preference is given to
the use of compounds of the formula la, in which R.sub.3, R.sub.4,
R.sub.5, R.sub.6 and R.sub.7 are hydrogen.
[0124] Further compounds of the formula Ia used with preference are
those in which R.sub.3 and R.sub.6 are methyl.
[0125] Other photoinitiator mixtures of interest are those in
which, in the compounds of the formula Ia, R.sub.3, R.sub.4,
R.sub.5, R.sub.6 and R.sub.7 are hydrogen.
[0126] Further preferred photoinitiator mixtures are those
comprising compounds of the formula Ia and compounds of the formula
II in which R.sub.8 is hydrogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, --OCH.sub.2CH.sub.2OR.sub.12, a group 20
[0127] R.sub.9 and R.sub.10 independently
[0128] of one another are hydrogen, C.sub.1-C.sub.3alkyl, phenyl,
C.sub.1-C.sub.12alkoxy or
--O(CH.sub.2CH.sub.2O).sub.q--C.sub.1-C.sub.8al- kyl in which q is
a number from 1 to 10, or R.sub.9 and R.sub.10, together with the
carbon atom to which they are attached, form a cyclohexyl ring;
R.sub.11 is hydroxyl, C.sub.1-C.sub.4alkoxy or
--O(CH.sub.2CH.sub.2O).sub- .q, --C.sub.1-C.sub.8alkyl; and/or
compounds of the formula III, and/or compounds of the formula IV in
which R.sub.18 is hydrogen or methoxy; R.sub.19 is methoxy,
methylthio, morpholino or a group of the formula IVa; R.sub.20 is
methyl or ethyl; R.sub.22 and R.sub.23 are the same and are methyl
or, together with the nitrogen atom to which they are attached,
form a five- or six-membered saturated ring which can be
interrupted by --O--; and R.sub.25 is hydrogen or
C.sub.1-C.sub.8alkyl.
[0129] There is likewise interest in a photoinitiator mixture
comprising compounds of the formula II in which R.sub.8 is
hydrogen, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy or
--OCH.sub.2CH.sub.2OR.sub.- 12; R.sub.9 and R.sub.10 independently
of one another are hydrogen, phenyl, methyl, or methoxy or R.sub.9
and R.sub.10, together with the carbon atom to which they are
attached, form a cyclohexyl ring; and R.sub.11 is hydroxyl or
methoxy.
[0130] Other preferred photoinitiator mixtures are those in which
the compound of the formula III is benzophenone,
2,4,6-trimethylphenyl phenyl ketone,4-methylphenyl phenyl ketone,
(3-methyl-4-methoxyphenyl 3-methylphenyl
ketone,4-(4-methylphenylthio)phenyl phenyl ketone, 2-carboxyphenyl
phenyl ketone or 4-(2-hydroxyethoxy)phenyl phenyl ketone. Also
preferred are photoinitiator mixtures in which the compound of the
formula II is 1-benzoyl-1-hydroxy-1-methylethane,
1-benzoylcyclohexanol,4-
-[(2-hydroxyethoxy)benzoyl]-1-hydroxy-1-methylethane,
1-(4-isopropylbenzoyl)-1-hydroxy-1-methylethane or
2,2-dimethoxy-1,2-diphenylethan-1-one.
[0131] Preference extends to photoinitiator mixtures in which the
compound of the formula IV is
1-(3,4-dimethoxybenzoyl)-1-benzyl-1-morpholinopropan-
e,1-(4-methylthiobenzoyl)-1-methyl-1-morpholinoethane,
1-(4-morpholinobenzoyl)-1-benzyl-1-dimethylaminopropane or
3,6-bis(2-methyl-2-morpholinopropan-1-one)-9-octylcarbazole.
[0132] Also of interest are photoinitiator mixtures in which the
compound of the formula Ia is
bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylpho- sphine oxide,
bis[2,6-dimethyl-4-(2-methylpropyl)benzoyl]phenylphosphine oxide,
bis(2,6-dimethylbenzoyl)phenylphosphine oxide,
bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide or
bis(2,4,6-trimethylbenzoyl)-2,5-dimethylphenylphosphine oxide.
[0133] The novel photoinitiator mixtures comprise, as compound of
the formula la, preferably
bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.
[0134] Preference is given to mixtures without benzophenone.
[0135] Preference is given to mixtures comprising compounds of the
formula II.
[0136] Also of interest are photoinitiator mixtures comprising, as
compound of the formula Ia,
bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylph- enylphosphine oxide;
bis(2,4,6-trimethylbenzoyl)-2-methylphenylphosphine oxide;
bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine oxide;
bis(2,4,6-trimethylbenzoyl)-2,5-diethylphenylphosphine oxide and/or
bis(2,4,6-trimethylbenzoyl)-2,3,5,6-tetramethylphenylphosphine
oxide.
[0137] Particular preference is given to a photoinitiator mixture
comprising 25% bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and
75% 1-benzoylcyclohexanol. Likewise preferred is a photoinitiator
mixture comprising 25% bis(2,4,6-trimethylbenzoyl)-phenylphosphine
oxide and 75% 1-benzoyl-1-hydroxy-1-methylethane.
[0138] Also of interest are photoinitiator mixtures comprising two
or more compounds of the formula Ia, or mixtures of compounds of
the formula Ia with other bisacylphosphine oxides and/or
monacylphosphine oxides and compounds of the formulae II and/or
III, for example a combination of bis
(2,4,6-trimethylbenzoyl)-phenylphosphine oxide,
bis(2,6-dimethoxybenzoyl)- (1,4,4-trimethylpentyl)phosphine oxide,
1-benzoylcyclohexanol or, for example, of
bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide,
bis(2,6-dimethoxybenzoyl)(1,4,4-trimethylpentyl)phosphinoxide and
1-benzoyl-1-hydroxy-1-methylethane or for example, of bis
(2,4,6-trimethylbenzoyl)-phenylphosphine oxide,
bis(2,4,6-trimethylbenzoy- l)-2,5-dimethylphenylphosphine oxide,
1-benzoyl-1-hydroxy-1-methylethane and/or
1-benzoyl-1-hydroxy-1-methylethane, of bis(2,4,6-trimethylbenzoyl)-
-phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine
oxide, 1-benzoyl-1-hydroxyl-1-methylethane and/or
1-benzoyl-1-hydroxy-1-methylet- hane, or of
bis(2,4,6-trimethylbenzoyl)-2,4-dipentoxyphenylphosphine oxide,
1-benzoyl-1-hydroxy-1-methylethane and/or 1-benzoyl-1-hydroxy-1-me-
thylethane.
[0139] In accordance with the invention, the compounds of the
formula I and the mixtures (blends) of compounds of the formula Ia
with compounds of the formula II and/or III and/or IV can be used
as photoinitiators for the photopolymerization of ethylenically
unsaturated compounds and of mixtures which include such compounds.
This use may also be practised in combination with other
additives.
[0140] The invention therefore also provides photopolymerizable
compositions comprising
[0141] (a) at least one ethylenically unsaturated
photopolymerizable compound and
[0142] (b) as photoinitiator, at least one compound of the formula
I or a photoinitiator mixture as described above,
[0143] it being possible for the composition to contain not only
component (b) but also other additives.
[0144] The unsaturated compounds may contain one or more olefinic
double bonds. They may be of low molecular mass (monomeric) or of
relatively high molecular mass (oligomeric). Examples of monomers
containing a double bond are alkyl or hydroxyalkyl acrylates or
methacrylates, for example, methyl, ethyl, butyl, 2-ethylhexyl- or
2-hydroxyethyl acrylate, isobornyl acrylate, or methyl or ethyl
methacrylate. Silicone acrylates are also of interest. Further
examples are acrylonitrile, acrylamide, methacrylamide,
N-substitututed (meth)acryl-amides, vinyl esters such as vinyl
acetate, vinyl ethers such as isobutyl vinyl ether, styrene, alkyl-
and halostyrenes, N-vinylpyrrolidone, vinyl chloride or vinylidene
chloride.
[0145] Examples of monomers containing two or more double bonds are
the diacrylates of ethylene glycol, propylene glycol, neopentyl
glycol, hexamethylene glycol and of
bisphenol-A,4,4'-bis(2-acryloyloxyethoxy)diph- enylpropane,
trimethylolpropane triacrylate, pentaerythritol triacrylate or
tetraacrylate, vinyl acrylate, divinyl benzene, divinyl succinate,
diallyl phthalate, triallyl phosphate, triallyl isocyanurate and
tris(2-acryloylethyl) isocyanurate.
[0146] Examples of relatively high molecular mass (oligomeric)
polyunsaturated compounds are acrylicized epoxy resins, and
polyethers, polyurethanes and polyesters which are acrylicized or
contain vinyl ether groups or epoxy groups. Further examples of
unsaturated oligomers are unsaturated polyester resins which are
mostly prepared from maleic acid, phthalic acid and one or more
diols and have molecular weights of from about 500 to 3000. In
addition it is also possible to employ vinyl ether monomers and
vinyl ether oligomers, and also maleate-terminated oligomers having
polyester, polyurethane, polyether, polyvinyl ether and epoxy main
chains. Combinations of oligomers which carry vinyl ether groups
and of polymers as described in WO 90/01512 are particularly
suitable. However, copolymers of vinyl ether and maleic acid
functionalized monomers are also appropriate. Such unsaturated
oligomers can also be referred to as prepolymers.
[0147] Examples of particularly suitable compounds are esters of
ethylenically unsaturated carboxylic acids and polyols of
polyepoxides, and polymers containing ethylenically unsaturated
groups in the chain or in side groups, for example unsaturated
polyesters, polyamides and polyurethanes and copolymers thereof,
polybutadiene and butadiene copolymers, polyisoprene and isoprene
copolymers, polymers and copolymers containing (meth)acrylic groups
in side chains, and mixtures of one or more such polymers.
[0148] Examples of unsaturated carboxylic acids are acrylic,
methacrylic, crotonic, itaconic and cinnamic acid, and unsaturated
fatty acids such as linolenic acid and oleic acid. Acrylic acid and
methacrylic acid are preferred.
[0149] Suitable polyols are aromatic polyols and, in particular,
aliphatic and cycloaliphatic polyols. Examples of aromatic polyols
are hydroquinone, 4,4'-dihydroxydiphenyl,
2,2-di(4-hydroxyphenyl)propane, and also novolaks and resols.
Examples of polyepoxides are those based on the said polyols,
especially on the aromatic polyols and epichlorohydrin. Other
suitable polyols include polymers and copolymers which contain
hydroxyl groups in the polymer chain or in side groups, for example
polyvinyl alcohol and copolymers thereof, or hydroxyalkyl
polymethacrylates or copolymers thereof. Further suitable polyols
are oligoesters containing hydroxyl end groups.
[0150] Examples of aliphatic and cycloaliphatic polyols are
alkylene diols, preferably with 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 with
molecular weights of preferably from 200 to 1500,
1,3-cyclopentanediol, 1,2- , 1,3- or 1,4- cyclohexanediol, 1,4-
dihydroxymethylcyclohexane, glycerol,
tris(.beta.-hydroxyethyl)amine- , trimethylolethane,
trimethylolpropane, pentaerythritol, dipentaerythritol and
sorbitol.
[0151] The polyols may be partially or completely esterified by
means of one or more unsaturated carboxylic acids, where the free
hydroxyl groups in partial esters may be modified, for example
etherified or esterified with other carboxylic acids.
[0152] Examples of esters are:
[0153] Trimethylolpropane triacrylate, trimethylolethane
triacrylate, trimethylolpropane trimethacrylate, trimethylolethane
trimethacrylate, tetramethylene glycol dimethacrylate, triethylene
glycol dimethacrylate, tetraethylene glycol diacrylate,
pentaerythritol diacrylate, pentaerythritol triacrylate,
pentaerythritol tetraacrylate, dipentaerythritol diacrylate,
dipentaerythritol triacrylate, dipentaerythritol tetraacrylate,
dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,
tripentaerythritol octacrylate, pentaerythritol dimethacrylate,
pentaerythritol trimethacrylate, dipentaerythritol dimethacrylate,
dipentaerythritol tetramethacrylate, tripentaerythritol
octamethacrylate, pentaerythritol diitaconate, dipentaerythritol
trisitaconate, dipentaerythritol pentaitaconate, dipentaerythritol
hexaitaconate, ethylene glycol diacrylate, 1,3-butanediol
diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol
diitaconate, sorbitol triacrylate, sorbitol tetraacrylate,
pentaerythritol-modified triacrylate, sorbitol tetramethyacrylate,
sorbitol pentaacrylate, sorbitol hexaacrylate, oligoester acrylates
and methacrylates, glycerol di- and -triacrylate, 1,4-cyclohexane
diacrylate, bisacrylates and bismethacrylates of polyethylene
glycol of molecular weight from 200 to 1500, or mixtures
thereof.
[0154] Further suitable components (a) are the amides of identical
or different unsaturated carboxylic acids of aromatic,
cycloaliphatic and aliphatic polyamines, preferably having 2 to 6,
in particular 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,
isophoronediamine, phenylendiamine, bisphenylenediamine, di-
.beta.-aminoethyl ether, diethylenetriamine, triethylenetetramine,
di(.beta.-aminoethoxy)- or di(.beta.-aminopropoxy)ethane. Further
suitable polyamines are polymers and copolymers which may contain
additional amino groups in the side chain, and oligoamides
containing amino end groups. Examples of unsaturated amides of this
kind are: methylenebisacrylamide, 1,6-hexamethylenebisacrylamide,
diethylenetriaminetrismethacrylamide,
bis(methacrylamidopropoxy)ethane, .beta.-methacrylamidoethyl
methacrylate, and N-[(.beta.-hydroxyethoxy)ethyl]acrylamide.
[0155] Suitable unsaturated polyesters and polyamides are derived,
for example, from maleic acid and diols or diamines. Some of the
maleic acid may be replaced by other dicarboxylic acids. They can
be employed together with ethylenically unsaturated comonomers, for
example styrene. The polyesters and polyamides may also be derived
from dicarboxylic acids and ethylenically unsaturated diols or
diamines, especially from relatively long-chain compounds
containing, for example, from 6 to 20 carbon atoms. Examples of
polyurethanes are those built up from saturated or unsaturated
diisocyanates and from unsaturated and/or saturated diols.
[0156] Polybutadiene and polyisoprene and copolymers thereof are
known. Examples of suitable comonomers are: olefins such as
ethylene, propene, butene, hexene, (meth)acrylates, acrylonitrile,
styrene and vinyl chloride. Polymers containing (meth)acrylate
groups in the side chain are also known. These may be, for example,
products of the reaction of novolak-based epoxy resins with
(meth)acrylic acid, homopolymers or copolymers of vinyl alcohol or
hydroxyalkyl derivatives thereof which have been esterified using
(meth)acrylic acid, or homopolymers and copolymers of
(meth)acrylates which have been esterified using hydroxyalkyl
(meth)acrylates.
[0157] The photopolymerizable compounds can be employed alone or in
any desired mixtures. Preference is given to mixtures of polyol
(meth)acrylates.
[0158] It is also possible to add binders to the novel
compositions, which is particularly expedient if the
photopolymerizable compounds are liquid or viscous substances. The
amount of binder may be, for example,5-95% by weight, preferably
10-90% by weight and, in particular, 40-90% by weight, based on the
overall solids content. The binder is chosen depending on the field
of use and on the properties required therefor, such as the
facility for development in aqueous and organic solvent systems,
adhesion to substrates, and sensitivity to oxygen.
[0159] Examples of suitable binders are polymers having a molecular
weight of about 5000-2 000 000, preferably 10 000-1 000 000.
Examples are homo- and copolymeric acrylates and methacrylates, for
example copolymers of methyl methacrylate/ethyl
acrylate/methacrylic acid, poly(alkyl methacrylate), poly(alkyl
acrylates); cellulose esters and cellulose ethers, such as
cellulose acetate, cellulose acetate butyrate, methylcellulose,
ethylcellulose; polyvinylbutyral, polyvinylformal, cyclized rubber,
polyether such as polyethylene oxide, polypropylene oxide,
polytetrahydrofuran; polystyrene, polycarbonate, polyurethane,
chlorinated polyolefins, polyvinyl chloride, copolymers of vinyl
chloride/vinylidene chloride, copolymers of vinylidene chloride
with acrylonitrile, methyl methacrylate and vinyl acetate,
polyvinyl acetate, copoly(ethylene/vinyl acetate), polymers such as
polycaprolactam and poly(hexamethyleneadipamide), and polyesters
such as poly(ethylene glycol terephthalate) and poly(hexamethylene
glycol succinate).
[0160] The unsaturated compounds can also be used in mixtures with
non-photopolymerizable film-forming components. These may, for
example, be physically drying polymers or solutions thereof in
organic solvents, for example nitrocellulose or cellulose
acetobutyrate. However, they can also be chemically curable or
heat-curable resins, for example polyisocyanates, polyepoxides or
melamine resins. The additional use of heat-curable resins is
important for use in so-called hybrid systems, which are
photopolymerized in a first step and are crosslinked by thermal
aftertreatment in a second step.
[0161] The photopolymerizable mixtures may contain various
additives in addition to the photoinitiator. Examples of these are
thermal inhibitors, which are intended to prevent premature
polymerization, examples being hydroquinone, hydroquinone
derivatives, p-methoxyphenol, .beta.-naphthol or sterically
hindered phenols, such as 2,6-di(tert-butyl)-p-cresol. The shelf
life in the dark can be increased, for example, by using copper
compounds, such as copper naphthenate, copper stearate or copper
octoate, phosphorus compounds, for example triphenylphosphine,
tributylphosphine, triethyl phosphite, triphenyl phosphite or
tribenzyl phosphite, quaternary ammonium compounds, such as
tetramethylammonium chloride or trimethylbenzylammonium chloride,
or hydroxylamine derivatives, such as N-diethylhydroxylamine. In
order to keep out atmospheric oxygen during the polymerization,
paraffin or similar waxlike substances can be added; these migrate
to the surface on commencement of the polymerization because of
their low solubility in the polymer, and form a transparent surface
layer which prevents the ingress of air. It is likewise possible to
apply an oxygen barrier layer. Light stabilizers which can be added
are UV absorbers, for example those of the
hydroxyphenylbenzotriazole, hydroxyphenylbenzophenone, oxalamide or
hydroxyphenyl-s-triazine type. It is possible to use individual
such compounds or mixtures thereof, with or without the use of
sterically hindered amines (HALS).
[0162] Examples of such UV absorbers and light stabilizers are
[0163] 1,2-(2'-Hydroxyphenyl)benzotriazoles, for example
2-(2'-hydroxy-5'-methylphenyl)-benzotriazole,
2-(3',5'-di-tert-butyl-2'-h- ydroxyphenyl)benzotriazole,
2-(5'-tert-butyl-2'-hydroxyphenyl)benzotriazol- e,
2-(2'-hydroxy-5'-(1,1,3,3-tetramethylbutyl)phenyl)-benzotriazole,
2-(3',5'-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole,
2-(3-tert-butyl-2'-hydroxy-5'-methylphenyl)-5-chlorobenzotriazole,
2-(3'-sec-butyl-5'-tert-butyl-2'-hydroxyphenyl)benzotriazole,
2-(2'-hydroxy-4'-octoxyphenyl)benzotriazole,
2-(3',5'-di-tert-amyl-2'-hyd- roxyphenyl)benzotriazole,
2-(3',5'-bis(.alpha.,.alpha.-dimethylbenzyl)-2'--
hydroxyphenyl)-benzotriazole, a mixture of
2-(3'-tert-butyl-2'-hydroxy-5'--
(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole,
2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)carbonylethyl]-2'-hydroxyphenyl)--
5-chlorobenzotriazole,
2-(3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylet-
hyl)phenyl)-5-chlorobenzotriazole,
2-(3'-tert-butyl-2'-hydroxy-5'-(2-metho-
xycarbonylethyl)phenyl)-benzotriazole,
2-(3'-tert-butyl-2'-hydroxy-5'-(2-o-
ctyloxycarbonylethyl)phenyl)benzotriazole,
2-(3'-tert-butyl-5-[2-(2-ethylh-
exyloxy)carbonylethyl]-2'-hydroxyphenyl)benzotriazole,
2-(3'-dodecyl-2'-hydroxy-5'-methylphenyl)benzotriazole, and
2-(3'-tert-butyl-2'-hydroxy-5'-(2-isooctyloxycarbonylethyl)phenylbenzotri-
azole,
2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-ylp-
henol]; the transesterification product of
2-[3'-tert-butyl-5'-(2-methoxy--
carbonylethyl)-2'-hydroxyphenyl]benzotriazole with polyethylene
glycol 300; [R--CH.sub.2CH.sub.2--COO(CH.sub.2).sub.3].sub.2 where
R=3'-tert-butyl-4'-hydroxy-5'-2H-benzotriazol-2-ylphenyl.
[0164] 2.2-Hydroxybenzophenones, for example the
4-hydroxy,4-methoxy,4-oct- oxy,4-decyloxy,
4-dodecyloxy,4-benzyloxy, 4,2',4'-trihydroxy and
2'-hydroxy-4,4'-dimethoxy derivative.
[0165] 3. Esters of substituted or unsubstituted benzoic acids, for
example4-tert-butyl-phenyl salicylate, phenyl salicylate,
octylphenyl salicylate, dibenzoylresorcinol,
bis(4-tert-butylbenzoyl)resorcinol, benzoylresorcinol,
2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxyben- zoate,
hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl
3,5-di-tert-butyl-4-hydroxybenzoate,
2-methyl-4,6-di-tert-butylphenyl
3,5-di-tert-butyl-4-hydroxybenzoate.
[0166] 4. Acrylates, for example ethyl
.alpha.-cyano-.beta.,.beta.-dipheny- lacrylate or isooctyl
.alpha.-cyano-.beta.,.beta.-diphenylacrylate, methyl
.alpha.-carbomethoxycinnamate, methyl
.alpha.-cyano-.beta.-methyl-p-metho- xy-cinnamate or butyl
.alpha.-cyano-.beta.-methyl-p-methoxycinnamate, methyl
.alpha.-carbomethoxy-p-methoxycinnamate and
N-(.beta.-carbomethoxy-.beta.-cyanovinyl)-2-methylindoline.
[0167] 5. Sterically hindered amines, for example
bis(2,2,6,6-tetramethylp- iperidyl) sebacate,
bis(2,2,6,6-tetramethylpiperidyl) succinate,
bis(1,2,2,6,6-pentamethylpiperidyl) sebacate,
bis(1,2,2,6,6-pentamethylpi- peridyl) n-butyl
3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of
1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic
acid, the condensate of
N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexameth- ylenediamine and
4-tert-octylamino-2,6-dichloro-1,3,5-triazine,
tris(2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate,
tetrakis(2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetraoate,
1,1'-(1,2-ethanediyl)bis(3,3,5,5-tetramethylpiperazinone),
4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethylp-
iperidine,
bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5--
di-tert-butylbenzyl) malonate,
3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazas-
piro[4.5]decane-2,4-dione,
bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate,
bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) succinate, the
condensate of
N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediami- ne
and4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of
2-chloro-4,6-di(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazi-
ne 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-tria-
zine and 1,2- bis(3-aminopropylamino)ethane,
8-acetyl-3-dodecyl-7,7,9,9-te-
tramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,
3-dodecyl-1-(2,2,6,6-tet-
ramethyl-4-piperidyl)pyrrolidine-2,5-dione,
3-dodecyl-1-(1,2,2,6,6-pentame-
thyl-4-piperidyl)pyrrolidine-2,5-dione.
[0168] 6. Oxalamides, for example 4,4'-dioctyloxyoxanilide,
2,2'-diethoxyoxanilide,
2,2'-dioctyloxy-5,5'-di-tert-butyloxanilide,
2,2'-didodecyloxy-5,5'-di-tert-butyloxanilide,
2-ethoxy-2'-ethyloxanilide- ,
N,N'-bis(3-dimethylaminopropyl)oxalamide,
2-ethoxy-5-tert-butyl-2'-ethyl- oxanilide and its mixture with
2-ethoxy-2'-ethyl-5,4'-di-tert-butyloxanili- de and mixtures of o-
and p-methoxy and of o- and p-ethoxy-disubstituted oxanilides.
[0169] 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-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazin-
e,
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-triazi-
ne,
2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropyloxy)phenyl]-4,6-bis(2,4-dime-
thylphenyl)-1,3,5-triazine,
2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)-
-phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,
2-[4-dodecyl/tridecyloxy-(2-hydroxypropyl)oxy-2-hydroxyphenyl]-4,6-bis(2,-
4-dimethylphenyl)-1,3,5-triazine.
[0170] 8. Phosphites and phosphonites, for example triphenyl
phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites,
tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl
phosphite, distearyl pentaerythritol diphosphite,
tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol
diphosphite, bis(2,4-di-tert-butylphenyl)penta- erythritol
diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythrit- ol
diphosphite, bisisodecyloxypentaerythritol diphosphite,
bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite,
bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite,
tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl)
4,4'-biphenylene diphosphonite,
6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1-
,3,2-dioxaphosphocin,
6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo-
[d,g]-1,3,2-dioxaphosphocin, bis(2,4-di-tert-butyl-6-methylphenyl)
methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl) ethyl
phosphite.
[0171] Consequently, the invention also provides photopolymerizable
compositions comprising as photoinitiator at least one compound of
the formula I, or a photoinitator mixture as described above, and a
UV absorber from the class of the hydroxyphenyl-s-triazines and/or
hydroxyphenylbenzotriazoles and/or sterically hindered amines based
on 2,2,6,6-tetramethylpiperidines.
[0172] Preference is given to a composition comprising a
photoinitiator mixture of compounds of the formulae la, especially
bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and compounds of
the formula II, especially 1-benzoylcyclohexanol and
1-benzoyl-1-hydroxy-1-me- thylethane, and a mixture of 85%
4,6-di(2,4-dimethylphenyl)-2-[2-hydroxy-4- -(mixture of dodecyloxy
and tridecyloxy)(2-hydroxy)propyl-3-oxyphenyl]-1,3- ,5-triazine and
15% 1-methoxy-2-propanol as UV absorber.
[0173] To accelerate the photopolymerization it is possible to add
amines, for example triethanolamine, N-methyldiethanolamine, ethyl
p-dimethylaminobenzoate or Michler's ketone. The action of the
amines can be intensified by the addition of aromatic ketones of
the benzophenone type. If use is made of novel mixtures comprising
compounds of the formula III, an improvement in the reactivity can
be obtained through the addition of amines. Examples of amines
which can be used as oxygen scavengers are substituted
N,N-dialkylanilines as described in EP-A-339 841. Further
accelerators, coinitiators and autoxidizers are thiols, thioethers,
disulfides and phosphines, as are described, for example, in
EP-A-438 123 and GB-A-2 180 358.
[0174] The photopolymerization can also be accelerated by the
addition of photosensitizers, which shift or broaden the spectral
sensitivity. These are, in particular, aromatic carbonyl compounds,
such as benzophenone derivatives, thioxanthone derivatives,
anthraquinone derivatives and 3-acylcoumarin derivatives, and also
3-(aroylmethylene)thiazolines, and also eosine, rhodamine and
erythrosine dyes.
[0175] The curing procedure can be assisted, in particular, by
compositions which are pigmented (for example with titanium
dioxide), and also by adding a component which forms free radicals
under thermal conditions, for example an azo compound such as
2,2'-azobis(4-methoxy-2,4- -dimethylvaleronitrile), a triazene, a
diazo sulfide, a pentazadiene or a peroxy compound, such as a
hydroperoxide or peroxycarbonate, for example t-butyl
hydroperoxide, as described in EP-A 245 639.
[0176] The novel compositions can also include a photoreducible
dye, for example xanthene, benzoxanthene, benzothioxanthene,
thiazine, pyronine, porphyrin or acridine dyes, and/or a
trihalomethyl compound which can be cleaved by radiation. Similar
compositions are described, for example, in EP-A-445 624.
[0177] Other conventional additives are--depending on the intended
application--fluorescent whiteners, fillers, pigments, dyes,
wetting agents or levelling assistants. Thick and pigmented
coatings can suitably be cured by the addition of glass microbeads
or powdered glass fibers, as described in U.S. Pat. No. 5,013,768,
for example.
[0178] The invention also provides compositions comprising as
component (a) at least one ethylenically unsaturated,
photopolymerizable compound which is emulsified or dissolved in
water.
[0179] Radiation-curable, aqueous prepolymer dispersions of this
type are commercially available in numerous variations. This term
is taken to mean a dispersion of water and at least one prepolymer
dispersed therein. The concentration of water in these systems is,
for example, from 5 to 80% by weight, in particular from 30 to 60%
by weight. The radiation-curable prepolymer or prepolymer mixture
is present, for example, in concentrations of from 95 to 20% by
weight, in particular from 70 to 40% by weight. The total of the
percentages indicated for water and prepolymers in these
compositions is in each case 100, to which are added the
auxiliaries and additives in various amounts depending on the
intended application.
[0180] The radiation-curable, water-dispersed, film-forming
prepolymers, which are frequently also dissolved, are, for aqueous
prepolymer dispersions, monofunctional or polyfunctional
ethylenically unsaturated prepolymers which are known per se, can
be initiated by means of free radicals and contain, for example,
from 0.01 to 1.0 mol of polymerizable double bonds per 100 g of
prepolymer, and have a mean molecular weight of, for example, at
least 400, in particular from 500 to 10,000. Depending on the
intended application, however, prepolymers having higher molecular
weights might also be suitable. For example, use is made of
polyesters containing polymerizable C-C double bonds and having a
maximum acid number of 10, polyethers containing polymerizable C-C
double bonds, hydroxyl-containing products of the reaction of a
polyepoxide containing at least two epoxide groups per molecule
with at least one .alpha.,.beta.-ethylenically unsaturated
carboxylic acid, polyurethane (meth)acrylates, and
.alpha.,.beta.-ethylenically unsaturated acrylic copolymers
containing acrylic radicals, as are described in EP-A-12 339.
Mixtures of these prepolymers may also be used. Also suitable are
the polymerizable prepolymers described in EP-A-33 896, which are
thioether adducts of polymerizable prepolymers having a mean
molecular weight of at least 600, a carboxyl group content of from
0.2 to 15% and a content of from 0.01 to 0.8 mol of polymerizable
C--C double bonds per 100 g of prepolymer. Other suitable aqueous
dispersions based on specific alkyl (meth)acrylate prepolymers are
described in EP-A-41 125; suitable water-dispersible,
radiation-curable prepolymers made from urethane acrylates are
disclosed in DE-A-2 936 039.
[0181] These radiation-curable, aqueous prepolymer dispersions may
include, as further additives, dispersion assistants, emulsifiers,
antioxidants, light stabilizers, dyes, pigments, fillers, for
example talc, gypsum, silica, rutile, carbon black, zinc oxide and
iron oxides, reaction accelerators, levelling agents, lubricants,
wetting agents, thickeners, matting agents, defoamers and other
assistants which are customary in coatings technology. Suitable
dispersion assistants are water-soluble organic compounds of high
molecular mass which contain polar groups, examples being polyvinyl
alcohols, polyvinylpyrrolidone and cellulose ethers. Emulsifiers
which can be used are nonionic emulsifiers and possibly also ionic
emulsifiers.
[0182] The photopolymerizable compositions comprise the
photoinitiator or the photoinitiator mixture (b) advantageously in
an amount of from 0.05 to 15% by weight, preferably from 0.1 to 5%
by weight, based on the composition.
[0183] Where the novel photoinitiators are employed in hybrid
systems, use is made - in addition to the novel free-radical
hardeners - of cationic photoinitiators, for example benzoyl
peroxide, aromatic sulfonium or iodonium salts, or
cyclopentadienylarene iron(II) complex salts.
[0184] In certain cases it may be an advantage to use further
initiators in addition to the novel compounds or photoinitiator
mixtures. For example, phosphines or phosphonium salts or, for
example, compounds of the formula 21
[0185] (described in U.S. Pat. No. 5,436,280 or JP-A-Hei 6 263809)
in which Q is S or O and R.sub.1', R.sub.2', R.sub.3' and R.sub.4'
are, for example, alkyl, alkenyl or aryl, and phosphites can be
used as additives.
[0186] The photopolymerizable compositions can be used for various
purposes, for example as printing inks, as transparent coatings, as
white paints, for example for wood or metal, as coating materials
for substrates including paper, wood, metal and plastic, as
daylight-curable coatings for marking buildings and roads, for
photographic reproduction techniques, for holographic recording
materials, for image recording processes or for the production of
printing plates which can be developed using organic solvents or
aqueous-alkaline media, for the production of masks for screen
printing, as dental filling materials, as adhesives, as
pressure-sensitive adhesives, as laminating resins, as etch resists
or permanent resists, and as solder masks for electronic circuits,
for the production of three-dimensional articles by bulk curing (UV
curing in transparent molds) or by the stereolithography process,
as is described, for example in U.S. Pat. No. 4,575,330, for the
preparation of composite materials (e.g. styrenic polyesters, which
may, if appropriate, contain glass fibers and other auxiliaries)
and other thick-layer compositions, for the coating or
encapsulation of electronic components, or as coatings for optical
fibers.
[0187] The novel compounds and photoinitiator mixtures can
additionally be used as initiators for emulsion polymerizations, as
initiators of a polymerization for the fixing of ordered states of
liquid-crystalline monomers and oligomers, and as initiators for
the fixing of dyes on organic materials.
[0188] In surface coatings, mixtures of a prepolymer with
polyunsaturated monomers are often used which also include a
monounsaturated monomer. The prepolymer here is primarily
responsible for the properties of the coating film, and variation
thereof allows the person skilled in the art to influence the
properties of the cured film. The polyunsaturated monomer functions
as a crosslinking agent which renders the coating film insoluble.
The monounsaturated monomer acts as a reactive diluent by means of
which the viscosity is reduced without the need to use a
solvent.
[0189] Unsaturated polyester resins are usually used in
two-component systems together with a monounsaturated monomer,
preferably with styrene. For photoresists, specific
single-component systems are often used, for example
polymaleimides, polychalkones or polyimides, as are described in
DE-A-2 308 830.
[0190] The novel compounds and mixtures may also be used, for
example, in coating materials which are in organic solvents and/or
water or are solvent-free.
[0191] The novel compounds and mixtures thereof can also be used as
free-radical photoinitiators or photoinitiating systems for
radiation-curable powder coatings. The powder coatings can be based
on solid resins and monomers containing reactive double bonds, for
example maleates, vinyl ethers, acrylates, acrylamides and mixtures
thereof. A free-radically UV-curable powder coating can be
formulated by mixing unsaturated polyester resins with solid
acrylamides (for example methyl methylacrylamidoglycolate) and a
novel free-radical photoinitiator, such formulations being as
described, for example, in the paper "Radiation Curing of Powder
Coating", Conference Proceedings, Radtech Europe 1993 by M. Wittig
and Th. Gohmann. Free-radically UV-curable powder coatings can also
be formulated by mixing unsaturated polyester resins with solid
acrylates, methacrylates or vinyl ethers and with a novel
photoinitiator (or photoinitiator mixture). The powder coatings may
also comprise binders as are described, for example, in DE-A-42 28
514 and in EP-A-636 669. The UV-curable powder coatings may
additionally comprise white or colored pigments. For example,
preferably rutiletitanium dioxide can be employed in concentrations
of up to 50% by weight in order to give a cured powder coating of
good hiding power. The procedure normally comprises electrostatic
or tribostatic spraying of the powder onto the substrate, for
example metal or wood, melting of the powder by heating, and, after
a smooth film has formed, radiation-curing of the coating with
ultraviolet and/or visible light, using, for example,
medium-pressure mercury lamps, metal halide lamps or xenon lamps. A
particular advantage of the radiation-curable powder coatings over
their heat-curable counterparts is that the flow time after melting
of the powder particles can be delayed if desired in order to
ensure the formation of a smooth, high-gloss coating. In contrast
to heat-curable systems, radiation-curable powder coatings can be
formulated to melt at lower temperatures without the unwanted
effect of shortening their lifetime. For this reason, they are also
suitable as coatings for heat-sensitive substrates, for example
wood or plastics. In addition to the novel photoinitiators, the
powder coating formulations may also include UV absorbers.
Appropriate examples are listed above in sections 1.-8.
[0192] The novel photocurable compositions are suitable, for
example, as coating materials for substrates of all kinds, for
example wood, textiles, paper, ceramic, glass, plastics such as
polyesters, polyethylene terephthalate, polyolefins or cellulose
acetate, especially in the form of films, and also metals such as
Al, Cu, Ni, Fe, Zn, Mg or Co and GaAs, Si or SiO.sub.2 to which it
is intended to apply a protective layer or, by means of imagewise
exposure, to generate a reproduced image.
[0193] Coating of the substrates can be carried out by applying to
the substrate a liquid composition, a solution or a suspension. The
choice of solvents and the concentration depend principally on the
type of composition and on the coating technique. The solvent
should be inert, i.e. it should not undergo a chemical reaction
with the components and should be able to be removed again, after
coating, in the course of drying. Examples of suitable solvents are
ketones, ethers and esters, such as methyl ethyl ketone, isobutyl
methyl ketone, cyclopentanone, cyclohexanone, N-methylpyrrolidone,
dioxane, tetrahydrofuran, 2-methoxyethanol, 2-ethoxyethanol,
1-methoxy-2-propanol, 1,2-dimethoxyethane, ethyl acetate, n-butyl
acetate and ethyl 3-ethoxypropionate. The solution is applied
uniformly to a substrate by means of known coating techniques, for
example by spin coating, dip coating, knife coating, curtain
coating, brushing, spraying, especially by electrostatic spraying,
and reverse-roll coating. It is also possible to apply the
photosensitive layer to a temporary, flexible support and then to
coat the final substrate, for example a copper-clad circuit board,
by transferring the layer via lamination.
[0194] The quantity applied (layer thickness) and the nature of the
substrate (layer support) are dependent on the desired field of
application. The range of layer thicknesses generally comprises
values from about 0.1 .mu.m to more than 100 .mu.m.
[0195] The novel radiation-sensitive compositions find application
as negative resists, having a very high sensitivity to light and
being able to be developed in an aqueous alkaline medium without
swelling. They are suitable as photoresists for electronics
(electroplating resist, etch resist, solder resist), the production
of printing plates, such as offset printing plates or screen
printing formes and/or the production of dies, for use in chemical
milling or as a microresist in the production of integrated
circuits. The possible layer supports, and the processing
conditions of the coated substrates, are just as varied.
[0196] Substrates used for photographic information recording
include, for example, films of polyester, cellulose acetate or
polymer-coated papers; substrates for offset printing formes are
specially treated aluminium, substrates for producing printed
circuits are copper-clad laminates, and substrates for producing
integrated circuits are silicon wafers. The layer thicknesses for
photographic materials and offset printing forms are generally from
about 0.5 .mu.m to 10 .mu.m, while for printed circuits they are
from 0.4 .mu.m to about 2 .mu.m.
[0197] Following the coating of the substrates, the solvent is
removed, generally by drying, to leave a coat of the photoresist on
the substrate.
[0198] The term "imagewise" exposure includes both exposure through
a photomask comprising a predetermined pattern, for example a
slide, exposure by means of a laser beam, which for example is
moved under computer control over the surface of the coated
substrate and in this way produces an image, and irradiation with
computer-controlled electron beams.
[0199] Following the imagewise exposure of the material and prior
to development, it may be advantageous to carry out thermal
treatment for a short time. In this case only the exposed sections
are thermally cured. The temperatures employed are generally
50-150.degree. C., preferably 8-130.degree. C.; the period of
thermal treatment is in general between 0.25 and 10 minutes.
[0200] The photocurable composition may additionally be used in a
process for producing printing plates or photoresists as is
described, for example, in DE-A-40 13 358. In such a process the
composition is exposed for a short time to visible light with a
wavelength of at least 400 nm, without a mask, prior to,
simultaneously with or following imagewise irradiation.
[0201] After the exposure and, if implemented, thermal treatment,
the unexposed areas of the photosensitive coating are removed with
a developer in a manner known per se.
[0202] As already mentioned, the novel compositions can be
developed by aqueous alkalis. Particularly suitable
aqueous-alkaline developer solutions are aqueous solutions of
tetraalkylammonium hydroxides or of alkali metal silicates,
phosphates, hydroxides and carbonates. Minor quantities of wetting
agents and/or organic solvents may also be added, if desired, to
these solutions. Examples of typical organic solvents, which may be
added to the developer liquids in small quantities, are
cyclohexanone, 2-ethoxyethanol, toluene, acetone and mixtures of
such solvents.
[0203] Photocuring is of great importance for printing inks, since
the drying time of the binder is a critical factor for the
production rate of graphic products, and should be in the order of
fractions of seconds. UV-curable inks are particularly important
for screen printing.
[0204] As already mentioned above, the novel mixtures are also
highly suitable for producing printing plates. This application
uses, for example, mixtures of soluble linear polyamides or
styrene/butadiene and/or styrene/isoprene rubber, polyacrylates or
polymethyl methacrylates containing carboxyl groups, polyvinyl
alcohols or urethane acrylates with photopolymerizable monomers,
for example acrylamides and/or methacrylamides, or acrylates and/or
methacrylates, and a photoinitiator. Films and plates of these
systems (wet or dry) are exposed over the negative (or positive) of
the printed original, and the uncured parts are subsequently washed
out using an appropriate solvent.
[0205] Another field where photocuring is employed is the coating
of metals, in the case, for example, of the coating of metal plates
and tubes, cans or bottle caps, and photocuring of polymer
coatings, for example of floor or wall coverings based on PVC.
[0206] Examples of the photocuring of paper coatings are the
colorless varnishing of labels, record sleeves and book covers.
[0207] Also of interest is the use of the novel compounds for
curing shaped articles made from composite compositions. The
composite composition consists of a self-supporting matrix
material, for example a glass fiber fabric, or alternatively, for
example, plant fibers [cf.K. -P. Mieck, T. Reussmann in Kunststoffe
85 (1995), 366-370], which is impregnated with the photocuring
formulation. Shaped parts comprising composite compositions, when
produced using the novel compounds, attain a high level of
mechanical stability and resistance. The novel compounds can also
be employed as photocuring agents in molding, impregnating and
coating compositions as are described, for example, in EP-A-7086.
Examples of such compositions are gel coat resins, which are
subject to stringent requirements regarding curing activity and
yellowing resistance, and fiber-reinforced moldings, for example
light-diffusing panels which are planar or have lengthwise or
crosswise corrugation. Techniques for producing such moldings, such
as hand lay-up, spray lay-up, centrifugal casting or filament
winding, are described, for example, by P. H. Selden in
"Glasfaserverstarkte Kunststoffe", page 610, Springer Verlag
Berlin-Heidelberg-New York 1967. Examples of articles which can be
produced by these techniques are boats, fiber board or chipboard
panels with a double-sided coating of glass fiber-reinforced
plastic, pipes, containers, etc. Further examples of molding,
impregnating and coating compositions are UP resin gel coats for
moldings containing glass fibers (GRP), such as corrugated sheets
and paper laminates. Paper laminates may be based on urea resins or
melamine resins. Prior to production of the laminate, the gel coat
is produced on a support (for example a film). The novel
photocurable compositions can also be used for casting resins or
for embedding articles, for example electronic components, etc.
Curing is carried out using medium-pressure mercury lamps as are
conventional in UV curing. However, there is also particular
interest in less intense lamps, for example of the type TL 40W/03
or TL40W/05. The intensity of these lamps corresponds approximately
to that of sunlight. It is also possible to use direct sunlight for
curing. A further advantage is that the composite composition can
be removed from the light source in a partly cured, plastic state
and can be shaped, with full curing taking place subsequently.
[0208] The use of photocurable compositions for imaging techniques
and for the optical production of information carriers is also
important. In such applications, as already described above, the
layer (wet or dry) applied to the support is irradiated through a
photomask with UV or visible light, and the unexposed areas of the
layer are removed by treatment with a solvent (=developer).
Application of the photocurable layer to metal can also be carried
out by electrodeposition. The exposed areas are polymeric through
crosslinking and are therefore insoluble and remain on the support.
Appropriate coloration produces visible images. Where the support
is a metallized layer, the metal can, following exposure and
development, be etched away at the unexposed areas or reinforced by
electroplating. In this way it is possible to produce printed
electronic circuits and photoresists.
[0209] The photosensitivity of the novel compositions extends in
general from the UV (about 200 nm) region about 600 nm and
therefore spans a very broad range. Suitable radiation is present,
for example, in sunlight or light from artificial light sources.
Consequently, a large number of very different types of light
source are employed. Both point sources and arrays ("lamp carpets")
are suitable. Examples are carbon arc lamps, xenon arc lamps,
medium-, high- and low-pressure mercury lamps, possibly doped with
metal halide (metal-halogen lamps), microwave-stimulated metal
vapour lamps, excimer lamps, superactinic fluorescent tubes,
fluorescent lamps, argon incandescent lamps, electronic flashlamps,
photographic floodlamps, electron beams and X-rays, produced by
means of synchrotrons or laser plasma. The distance between the
lamp and the substrate to be exposed in accordance with the
invention may vary depending on the intended application and the
type and output of the lamp, and may be, for example, from 2 cm to
150 cm. Laser light sources, for example excimer lasers, are
especially suitable, such as krypton F lasers for exposure at 248
nm. Lasers in the visible region can also be employed. In this
case, the high sensitivity of the novel materials are very
advantageous. By this method it is possible to produce printed
circuits in the electronics industry, lithographic offset printing
plates or relief printing plates, and also photographic
image-recording materials.
[0210] The invention additionally provides for the use of the
above-described composition for preparing coating materials,
printing inks, printing plates, dental compositions, resist
materials, and as image recording material, especially for
holographic recordings.
[0211] The invention additionally provides a coated substrate which
is coated on at least one surface with a composition as described
above, and provides a process for the photographic production of
relief images, in which a coated substrate is subjected to
imagewise exposure and then the unexposed portions are removed with
a solvent. Imagewise exposure in this case can take place through a
mask or else using a controlled laser (without a mask).
[0212] The invention thus also provides a process for the
photopolymerization of compounds containing ethylenically
unsaturated double bonds, which comprises irradiating a composition
as described above, with light in the range from 200 to 600 nm.
[0213] The compounds of the formulae I and Ia are photosensitive
solids, which are generally yellow, and which are soluble, for
example, in esters, aromatic compounds, alcohols and chlorinated
hydrocarbons.
[0214] The novel photoinitiator mixtures (blends) are of good
solubility in the substrate that is to be cured. In this context,
the solubility of the blends in the substrate to be cured is
generally better than the solubility of the individual components.
In the blend, one component acts as a solubilizer for the
others.
[0215] When carrying out curing with the novel blends, an optimum
ratio can be obtained between the curing of the surface of the
substrate and its through-curing. The photoinitiator mixtures are
reactive, and low yellowing values can be achieved in the course of
curing.
[0216] The examples which follow illustrate the invention in more
detail. Parts and percentages, as in the remainder of the
description and in the claims, are by weight unless indicated
otherwise.
EXAMPLE 1
[0217] Preparation of bis
(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine oxide 22
[0218] (a)4-Methylphenyldiethylphosphonate
[0219] lin a Hickmann apparatus, 51.3 g of 4-bromotoluene are
heated with 3.9 g of nickel(II) chloride to 160.degree. C. 74.8 g
of triethyl phosphite are added dropwise over the course of one
hour. The reaction mixture is then heated at 160.degree. C. for 2
hours. Subsequently, 22 g of ethyl bromide are distilled off.
Distillation at 90.degree. C./10.sup.-2 mbar gives 38.6 g of
4-methylphenyldiethylphosphonate.
[0220] (b)4-Methylphenylphosphine
[0221] 8.23 g of lithium aluminium hydride are placed in 180 ml of
dry diethyl ether, and 16.43 g of 4-methylphenyldiethylphosphonate
are added at -10.degree. C. The suspension is stirred at room
temperature for 18 hours and then washed carefully with 8 ml of
water at 0.degree. C. and 5.degree. C., and hydrolysed with 8 g of
15% NaOH solution and 24 ml of water, to give a bulky white
precipitate. This precipitate is filtered off under argon, and
washed with 50 ml of ether, and the solvent is distilled off under
argon, to give 9.0 g of 4-methylphenylphosphine which is used
without further purification for the preparation of the next
stage.
[0222] (c) Bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine
[0223] A solution of 16.2 g of diisopropylamine in 50 ml of
tetrahydrofuran (THF) is cooled to -10.degree. C. 100 ml of
butyllithium in hexane (1.6 M) are added dropwise. Then, at
-40.degree. C., first 9.0 g of 4-methylphenylphosphine and,
subsequently, a solution of 29.22 g of 2,4,6-trimethylbenzoyl
chloride in 150 ml of THF are added. The solution is stirred for
1.5 hours and then the solvent is removed under reduced pressure,
to give 28.0 g of bis(2,4,6-trimethylbenzoyl)-4-methylphenylpho-
sphine as a yellow powder.
[0224] (d) Bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine
oxide
[0225] 28.0 g of
bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine are dissolved
in 100 ml of toluene and the solution is heated to 50.degree. C.
8.2 g of 30% hydrogen peroxide are added dropwise over the course
of one hour. The reaction mixture is then allowed to cool to room
temperature, and the phases which develop are separated. The
organic phase is washed with 30 ml of water, 30 ml of 10% sodium
bicarbonate solution and water until neutral, then is dried over
magnesium sulfate, filtered and concentrated in vacuo, to give 24.5
g of a yellow oil. Column chromatography and recrystallization from
petroleum ether give 12. g of the title product as yellow crystals
with a melting point of 151-152.degree. C.
[0226] Elemental analysis:
1 calc. C: 74.98% found: C: 74.90% H: 6.76% H: 6.75%
EXAMPLES 2-9
[0227] The compounds of Example 2 to 9 are obtained by following
the method described in Example 1 and using the appropriately
substituted starting materials. The compounds and their physical
data are given in Table 1 below.
2TABLE 1 23 Elemental analysis [%] calculated mp [%] found Example
R.sub.1 R.sub.2 R.sub.3 R.sub.5 R.sub.6 R.sub.7 [.degree. C.] C H 1
CH.sub.3 CH.sub.3 H CH.sub.3 H H 152 74.90 6.75 74.98 6.76 2
CH.sub.3 CH.sub.3 CH.sub.3 H H H 132 74.81 6.80 74.98 6.76 3
CH.sub.3 CH.sub.3 CH.sub.3 CH.sub.3 H CH.sub.3 163 75.47 7.30 75.63
7.22 4 CH.sub.3 CH.sub.3 CH(CH.sub.3).sub.2 H CH(OH.sub.3).sub.2
H160 76.17 7.92 76.47 7.82 5 CH.sub.3 CH.sub.3 CH.sub.3
C(CH.sub.3).sub.3 H CH.sub.3 146 76.58 8.03 76.47 7.82 6 CH.sub.3
CH.sub.2CH(CH.sub.3).sub.2 H H H H resin 76.22 8.02 76.47 7.82 7
CH.sub.3 H H H H H 93 73.61 6.02 73.81 5.94 8 CH.sub.3 CH.sub.3 H H
H H 132 74.63 6.50 74.67 6.52 * 9 CH.sub.3 CH.sub.3 CH.sub.3 H
CH.sub.3 H 122 75.04 6.97 75.32 7.00 ** *The shift .delta. in the
.sup.31P-NMR spectrum is 7.50 ppm. **The shift .delta. in the
.sup.31P-NMR spectrum is 14.95 ppm.
EXAMPLE 10
[0228] Preparation and curing of a transparent coating A UV-curable
clearcoat is prepared by mixing
[0229] 99.5 parts of .RTM.Roskydal 502 (=66% unsaturated polyester
resin and 34% styrene; Bayer)
[0230] 0.5 part of .RTM.Byk 300 (=levelling assistant,
Byk-Mallinckrodt).
[0231] Two parts of a mixture of 95%
1-benzoyl-1-hydroxy-1-methylethane and 5% of the photointiator from
Example 8 are incorporated into this formulation. The coating
material is to a chipboard panel using a doctor blade with a 200
.mu.m gap and is then cured.
[0232] Curing is conducted by passing the sample, on a conveyor
belt moving at a speed of 5 m/min, underneath two medium-pressure
mercury lamps of the 120 W/cm Fusion H type (Fusion Systems, USA)
and 80 W/cm Hanovia type (Canrad-Hanovia, USA). The Konig pendulum
hardness (DIN 53157) of the smearproof coating is 52 seconds.
EXAMPLE 11
[0233] Preparation and curing of a white paint A UV-curable white
paint is prepared by mixing
[0234] 67.5 parts of .RTM.Ebecryl 830 (Polyester acrylate from UCB,
Belgium)
[0235] 5.0 parts of 1,6-hexanediol diacrylate
[0236] 2.5 parts of trimethylolpropane triacrylate and
[0237] 25.0 parts of .RTM.R-TC2 (rutile titanium dioxide, from
Tioxide)
[0238] 3 parts of a photoinitiator mixture of 75%
1-benzoyl-1-hydroxy-1-me- thylethane and 25% of of the
photoinitiator from Example 8 are incorporated into this paint
formulation. The paint is applied to a coil-coated aluminium panel
using a doctor blade with a 100 .mu.m gap, and is exposed on a
conveyor belt to an 80 W/cm medium-pressure mercury lamp
(Canrad-Hanovia, USA). The maximum belt speed at which a smearproof
and through-cured coat is obtained is a measure of the reactivity
of the photoinitiator mixture. A coat cured at a belt speed of 3
m/min has a Konig pendulum hardness (DIN 53157) of 159 seconds.
EXAMPLE 12
[0239] Preparation and curing of a white paint Similarly, in each
case 3 parts of a photoinitiator mixture of 75%
1-benzoyl-1-hydroxy-cyclohexane and 25% of the photoinitators from
Examples 2, 4 and 7 were tested in the formulation described in
Example 11. The corresponding white-paint coats are likewise cured
at a belt speed of 15 m/min.
EXAMPLE 13
[0240] Preparation and curing of a highly pigmented white paint A
UV-curable white paint is prepared by mixing
[0241] 45 parts of .RTM.Ebecryl 830
[0242] 3 parts of 1,6-hexanediol diacrylate
[0243] 2 parts of trimethylolpropane triacrylate
[0244] 50 parts of .RTM.R-TC2 (rutile titanium dioxide)
[0245] 4 parts of a photoinitiator mixture of 75%
1-benzoyl-1-hydroxycyclo- hexane and 25% of the photoinitiator from
Example 8 are incorporated into this paint formulation. The paint
is applied to coil-coated aluminium panels using a doctor blade
with a 150 .mu.m gap and is cured on a conveyor belt under two 80
W/cm medium-pressure mercury lamps (Aetek, USA). At a belt speed of
10 m/min, a smearproof and through-cured coat is obtained whose
Konig pendulum hardness (DIN 53157) is 85 seconds. 4 parts of a
photoinitiator mixture of 75% 1-benzoyl-1-hydroxycyclohexane and
25% of the photoinitiator from Example 3 likewise give a smearproof
surface and through-cured coat at a belt speed of 10 m/min, with a
pendulum hardness of 79 seconds.
EXAMPLE 14
[0246] Curing of a laminar composite A formulation is prepared
from
[0247] 99 parts of .RTM.Vestopal X7231 (unsaturated polyester from
Huls, Germany) and
[0248] 1 part of a photoinitiator mixture of 75% benzyl dimethyl
ketal and 25% of the photointiator from Example 8
[0249] A lamina of 4 layers of a glass fiber mat (chopped strand
material) and the above formulation are covered with a transparent
Mylar film and subjected to firm compression. This assembly is then
irradiated under 5 lamps of type TL40W/03 (Philips) at a distance
of 15 cm for 10 minutes. A stable composite layer is obtained which
has a Shore hardness D (in accordance with DIN 53505; determined
with a hardness tester from Otto Wolpert Werke, Ludwigshafen,
Germany) of 65.
EXAMPLE 15
[0250] Preparation and curing of an amino-containing clearcoat 2
parts of a photoinitiator mixture of 45% benzophenone, 45%
1-benzoyl-1-hydroxy-cyc- lohexane and 10% of the photoinitiator
from Example 8 are mixed with 98 parts of an amino-containing
polyether acrylate (.RTM.Laromer PO84 F, BASF). The coating
material is applied to chipboard panels using a doctor blade with a
100 .mu.m gap and is cured at a belt speed of 10 m/min using two 80
W/cm medium-pressure mercury lamps (Aetek, USA). The smearproof
coat has a Konig pendulum hardness (DIN 53157) of 65 seconds.
EXAMPLE 16
[0251] Preparation and curing of a powder coating A UV-curable
powder coating is prepared from
[0252] 56.0 parts of .RTM.ZA 3125 (DSM, Holland)
[0253] 11.0 parts of .RTM.ZA 3126 (DSM, Holland)
[0254] 33.0 parts of .RTM.R-TC2 (rutile titanium dioxide)
[0255] 1.0 part of .RTM.Resiflow PV5 (E.H. Worlee, Germany)
[0256] 0.5 part of .RTM.Worlee Add 900 (E.H. Worlee, Germany)
[0257] 3.0 parts of a photoinitiator mixture of 75%
4(2-hydroxyethoxy)benzoyl-1-hydroxy-1-methylethane and 25% of the
photoinitiator from Example 8
[0258] All of the components are mixed in an extruder at 80.degree.
C., to give a homogeneous white paint. After cooling, the solid
mass is ground and sieved. The powder with a particle size of
<90 .mu.m is applied in a film thickness of 60-90 .mu.m to an
aluminium panel using an electrostatic spray method. The coated
panel is heated at 125.degree. C. in an oven for 3 minutes. During
this period, the powder melts and a homogeneous film is formed. The
film is irradiated while still hot, at a belt speed of 7.5 m/min,
under two 80 W/cm medium-pressure mercury lamps. After irradiation
for 30 minutes, a Konig pendulum hardness of 105 seconds is
measured.
EXAMPLE 17
[0259] A pastel-colored paint is prepared by mixing
[0260] 75.5 parts of Ebecryl.RTM. 830 (polyester acrylate
oligomer)
[0261] 9.0 parts of 1,6-hexanediol diacrylate (HDODA)
[0262] 4.5 parts of trimethylolpropane triacrylate (TMPTA)
[0263] To this paint there are added 3% (3 parts) of a
photoinitiator mixture of 75% benzyl dimethyl ketal and 25% of of
the photoinitiator from Example 1. A paint film of 100 .mu.m is
applied to a wooden panel and is exposed, at a belt speed of 3
m/min, under two 80W/cm medium-pressure mercury lamps (Aetek, USA).
A smearproof and through-cured coat is obtained whose Konig
pendulum hardness (DIN 53157) is 115 seconds.
EXAMPLE 18
[0264] A yellow paint is prepared from
[0265] 83.0 parts of Ebecryl.RTM. 830 (polyester acrylate
oligomer)
[0266] 9.5 parts of 1,6-hexanediol diacrylate (HDODA)
[0267] 4.0 parts of trimethylolpropane triacrylate (TMPTA)
[0268] 3.0 parts of Irgazin.RTM. Gelb GLTN (yellow pigment)
[0269] 3 parts of the photoinitiator mixture from Example 17 are
added to this paint. The paint is applied as described in Example
17 and is exposed, at a belt speed of 3 m/min, with an 80 W/cm
medium-pressure mercury lamp (Canrad-Hanovia, USA). The pendulum
hardness of the smearproof and through-cured coat is 142
seconds.
EXAMPLE 19
[0270] UV stabilization of a clearcoat
[0271] A clearcoat is prepared by mixing
[0272] 99.5 parts of Roskydal.RTM. 502 (=66% unsaturated polyester
with 34% styrene, BAYER), and
[0273] 0.5 part of Byk.RTM. 300 (levelling assistant,
Byk-Mallinckrodt)
[0274] A liquid 3-component mixture is prepared by heating a
photoinitiator mixture of 75% 1-benzoyl-1-hydroxycyclohexane and
25% of the photoinitiator from Example 1 to 50.degree. C. and
adding the same amount by weight of a mixture of 85%
4,6-di(2,4-dimethylphenyl)-2-[2-hydr- oxy-4-(mixture of dodecyloxy
and tridecyloxy)(2-hydroxy)propyl-3-oxyphenyl- ]-1,3,5-triazine and
15% 1-methoxy-2-propanol. 4 parts of this liquid mixture are
incorporated into the clearcoat. Coats are applied to wood (pale
substrate) using a doctor blade with a 150 .mu.m gap, and are
exposed at a belt speed of 3 m/min, using two 80 W/cm
medium-pressure mercury lamps. The pendulum hardnesses (PH) and
yellowness indices (YL) (according to ASTMD 1925) are measured
directly after curing and after 4 hours of subsequent exposure
under TL 20W/05 fluorescent lamps (Philips).
[0275] The sample with the liquid 3-component mixture can be cured
readily and gives an adequate photoprotective action (UV
stabilization), as shown by the data in Table 2.
3 TABLE 2 after curing 4 hours TL 20W/05 Additives PH YI PH YI 4
parts of liquid 3-component 88 9.8 134 9.5 mixture
EXAMPLE 20
[0276] Incorporation of a liquid mixture into an aqueous pigmented
formulation:
[0277] A pigmented aqueous formulation is prepared by mixing the
following components:
[0278] 50 parts of Roskydal.RTM. 850 W (unsaturated polyester,
BAYER)
[0279] 50 parts of Laromer.RTM. PE 55 W (emulsion of a polyester
acrylate in water, BASF)
[0280] 10 parts of titanium dioxide R-TC2 (rutile type)
[0281] 20 parts of water
[0282] photoinitiator mixture of 75% 1-benzoyl-1-hydroxycyclohexane
and 25% of the photoinitiator from Example 1 is liquefied at
50.degree. C., and 3 parts thereof are incorporated at room
temperature into the above formulation, with stirring. Coats 150
.mu.m thick are applied to wood, dried at 80.degree. C. for 4
minutes and then exposed at 3 m/min under two 80 W/cm
medium-pressure mercury lamps. The coating with the liquefied
photoinitiator mixture gives a pendulum hardness of 50 seconds, a
yellowness index of 4.3 and gloss values (at measurement angles of
20.degree. and 60.degree.) of 75/87.
* * * * *