U.S. patent application number 16/386364 was filed with the patent office on 2019-08-29 for substituted triazines and a method for producing same.
The applicant listed for this patent is Covestro Deutschland AG. Invention is credited to Guiseppe CHIOVETTA, Koichi KAWAMURA, Thomas Roelle.
Application Number | 20190263761 16/386364 |
Document ID | / |
Family ID | 53487235 |
Filed Date | 2019-08-29 |
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United States Patent
Application |
20190263761 |
Kind Code |
A1 |
Roelle; Thomas ; et
al. |
August 29, 2019 |
SUBSTITUTED TRIAZINES AND A METHOD FOR PRODUCING SAME
Abstract
The present invention provides aromatic
4,6-bis-trichloromethyl-s-triazin-2-yl compounds of formula (I), a
process for producing para-disubstituted benzonitriles as precursor
to give compounds of formula (I) and a process for the production
thereof.
Inventors: |
Roelle; Thomas; (Leverkusen,
DE) ; KAWAMURA; Koichi; (Odenthal, DE) ;
CHIOVETTA; Guiseppe; (Hurth, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Covestro Deutschland AG |
Leverkusen |
|
DE |
|
|
Family ID: |
53487235 |
Appl. No.: |
16/386364 |
Filed: |
April 17, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15738905 |
Dec 21, 2017 |
10308619 |
|
|
PCT/EP2016/064305 |
Jun 21, 2016 |
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16386364 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G03F 7/001 20130101;
G03F 7/031 20130101; C07C 253/30 20130101; C07D 251/24 20130101;
C07C 67/02 20130101; G11B 7/24044 20130101; G03F 7/029 20130101;
G11B 7/245 20130101; C07C 253/30 20130101; C07C 255/57
20130101 |
International
Class: |
C07D 251/24 20060101
C07D251/24; G03F 7/029 20060101 G03F007/029; G03F 7/031 20060101
G03F007/031; G11B 7/245 20060101 G11B007/245; C07C 67/02 20060101
C07C067/02; C07C 253/30 20060101 C07C253/30; G11B 7/24044 20060101
G11B007/24044; G03F 7/00 20060101 G03F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 23, 2015 |
EP |
15173235.1 |
Claims
1.-7. (canceled)
8. Compounds of formula (I) ##STR00008## wherein X is halogen and
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each independently
hydrogen, halogen, alkyl, alkoxy, alkenyl, alkynyl, alkylthio,
alkylseleno, wherein R.sup.1 and R.sup.2 and/or R.sup.3 and R.sup.4
may combine to form a 3 to 5-membered saturated or unsaturated
bridge optionally substituted with up to 2 heteroatoms and R.sup.5
is linear C.sub.5 to C.sub.20 alkyl which is optionally substituted
in any manner by halogen and/or C.sub.1 to C.sub.10 alkyl and/or
C.sub.1 to C.sub.10 alkoxy and in which up to six carbon atoms may
be replaced by oxygen, in which case at least two carbon atoms
shall be present between two oxygen atoms and the R.sup.5 moiety
starts with at least two carbon atoms, wherein the terminal methyl
group of the linear C.sub.5 to C.sub.20 alkyl moiety shall be
unsubstituted.
9. Compounds according to claim 8, wherein R.sup.5 may in one
embodiment of the invention be linear C.sub.6 to C.sub.20 alkyl
which is optionally substituted in any manner by halogen and/or
C.sub.1 to C.sub.4 alkyl and/or C.sub.1 to C.sub.4 alkoxy and in
which up to six carbon atoms may be replaced by oxygen, in which
case at least two carbon atoms shall be present between two oxygen
atoms and the R.sup.5 moiety starts with at least two carbon atoms,
wherein the terminal methyl group of the linear C.sub.6 to C.sub.20
alkyl moiety shall be unsubstituted.
10. Compounds according to claim 8, wherein X is chlorine and
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each H.
11. Process for producing the compounds of formula (I) ##STR00009##
wherein X is halogen and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are
each independently hydrogen, halogen, alkyl, alkoxy, alkenyl,
alkynyl, alkylthio, alkylseleno, wherein R.sup.1 and R.sup.2 and/or
R.sup.3 and R.sup.4 may combine to form a 3 to 5-membered saturated
or unsaturated bridge optionally substituted with up to 2
heteroatoms and R.sup.5 is linear C.sub.5 to C.sub.20 alkyl which
is optionally substituted in any manner by halogen and/or C.sub.1
to C.sub.10 alkyl and/or C.sub.1 to C.sub.10 alkoxy and in which up
to six carbon atoms may be replaced by oxygen, in which case at
least two carbon atoms shall be present between two oxygen atoms
and the R.sup.5 moiety starts with at least two carbon atoms,
wherein the terminal methyl group of the linear C.sub.5 to C.sub.20
alkyl moiety shall be unsubstituted by using the process according
to claim 8 which comprises utilizing the one-pot process to prepare
para-disubstituted benzonitriles of formula (IV) in a first step
and reacting the resulting para-disubstituted benzonitrile with
trihaloacetonitrile in a second step.
Description
[0001] The present invention relates to aromatic
4,6-bis-trichloromethyl-s-triazin-2-yl compounds of formula (I), a
process for producing para-disubstituted benzonitriles as precursor
to give compounds of formula (I) and a process for the production
thereof.
[0002] European application EP13198913.9, unpublished at the
priority date of the present invention, discloses light-sensitive
photopolymers which comprise polyurethane matrix polymers, an
acrylate-based writing monomer and also photoinitiators comprising
two coinitiators and a dye. The uses of photopolymers are
decisively determined by the refractive index modulation .DELTA.n
produced by holographic exposure. In holographic exposure, the
interference field of signal light beam and reference light beam
(that of two plane waves in the simplest case) is mapped into a
refractive index grating by the local photopolymerization of
writing monomers such as, for example, high-refractive acrylates at
loci of high intensity in the interference field. The refractive
index grating in the photopolymer (the hologram) contains all the
information of the signal light beam. Illuminating the hologram
with only the reference light beam will then reconstruct the
signal. The strength of the signal thus reconstructed relative to
the strength of the incident reference light is called the
diffraction efficiency, DE in what follows.
[0003] In the simplest case of a hologram resulting from the
superposition of two plane waves, the DE is the ratio of the
intensity of the light diffracted on reconstruction to the sum
total of the intensities of diffracted light and nondiffracted
light. The higher the DE, the greater the efficiency of a hologram
with regard to the amount of reference light needed to visualize
the signal with a fixed brightness.
[0004] In order that a very high .DELTA.n and DE may be realized
for holograms, the matrix polymers and the writing monomers of a
photopolymer formulation should in principle be chosen such that
there is a very large difference in their refractive indices. One
possible way to realize this is to use matrix polymers having a
very low refractive index and writing monomers having a very high
refractive index. Suitable matrix polymers of low refractive index
are, for example, polyurethanes obtainable by reaction of a polyol
component with a polyisocyanate component.
[0005] In addition to high DE and .DELTA.n values, however, another
important requirement for holographic media from photopolymer
formulations is that the matrix polymers be highly crosslinked in
the final medium. When the degree of crosslinking is too low, the
medium will lack adequate stability. One consequence of this is to
appreciably reduce the quality of holograms inscribed in the media.
In the worst case, the holograms may even be subsequently
destroyed.
[0006] It is further very important, in particular for the large
scale industrial production of holographic media from photopolymer
formulations, that the photosensitivity be sufficient to achieve
large-area exposure with any given source of laser light without
loss of index modulation. Particularly the choice of a suitable
photoinitiator here is of decisive importance for the properties of
the photopolymer.
[0007] However, holographic exposure using a continuous source of
laser light comes up against technical limits in the case of
large-area exposure, since efficient formation of the hologram will
always require a certain minimum of light per unit area and the
technically available laser power is limited. Large-area exposures
at a comparatively low dose of radiation additionally require long
exposure times which in turn impose very high requirements on the
mechanical damping of the exposure set-up to eliminate
vibration.
[0008] A further possible way to achieve large-area exposure of
holograms consists in using very short pulses of light, for example
from pulsed lasers or continuous wave lasers in conjunction with
very fast shutters. Pulse durations with pulsed lasers are
typically 500 ns or less. Pulse durations with continuous wave
lasers and very fast shutters are typically 100 is or less. In
effect, the same amount of energy can be introduced here as with
continuous lasers in seconds. Holograms can be written in this way
dot by dot. Since pulsed lasers or fast optical shutters are
technically available and an exposure set-up of this type has very
low requirements with regard to mechanical damping to eliminate
vibration, this amounts to a good technical alternative to the
above-described set-ups involving continuous lasers for large-area
exposure of holograms.
[0009] The photopolymers known from European application
EP13198913.9 are generally usable for writing holograms with pulsed
lasers but a further increase in sensitivity of the photopolymer is
desirable for broad industrial utility.
[0010] The problem addressed by the present invention was therefore
that of providing a compound useful in the production of
photopolymers whereinto bright holograms can be written with pulsed
lasers by reason of higher photosensitivity.
[0011] This problem is solved by a compound of formula (I)
##STR00001##
characterized in that X is halogen and R.sup.1, R.sup.2, R.sup.3
and R.sup.4 are each independently hydrogen, halogen, alkyl,
alkoxy, alkenyl, alkynyl, alkylthio, alkylseleno, wherein R.sup.1
and R.sup.2 and/or R.sup.3 and R.sup.4 may combine to form a 3 to
5-membered saturated or unsaturated bridge optionally substituted
with up to 2 heteroatoms and R.sup.5 is linear C.sub.5 to C.sub.20
alkyl which is optionally substituted in any manner by halogen
and/or C.sub.1 to C.sub.10 alkyl and/or C.sub.1 to C.sub.10 alkoxy
and in which up to six carbon atoms may be replaced by oxygen, in
which case at least two carbon atoms shall be present between two
oxygen atoms and the R.sup.5 moiety starts with at least two carbon
atoms, wherein the terminal methyl group of the linear C.sub.5 to
C.sub.20 alkyl moiety shall be unsubstituted.
[0012] This is because it was found that, surprisingly, media which
comprise a compound of formula (I) according to the present
invention have a higher level of photosensitivity and hence are
very useful for exposure using pulsed lasers.
[0013] In one preferred embodiment of the invention, the X moiety
represents chlorine. In a further embodiment of the invention,
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each hydrogen. R.sup.5
may in one embodiment of the invention be linear C.sub.6 to
C.sub.20 alkyl which is optionally substituted in any manner by
halogen and/or C.sub.1 to C.sub.4 alkyl and/or C.sub.1 to C.sub.4
alkoxy and in which up to six carbon atoms may be replaced by
oxygen, in which case at least two carbon atoms shall be present
between two oxygen atoms and the R.sup.5 moiety starts with at
least two carbon atoms, wherein the terminal methyl group of the
linear C.sub.6 to C.sub.20 alkyl moiety shall be unsubstituted.
[0014] It is likewise preferable when the compound of formula (I)
has an X moiety representing chlorine, the moieties R.sup.1,
R.sup.2, R.sup.3 and R.sup.4 each representing H and the R.sup.5
representing 2-ethylhexanol.
[0015] According to EP 0332 042 A2,
4,6-bis-trichloromethyl-s-triazin-2-yl-phenyl derivatives are
obtainable from aromatic nitriles and trichloroacetonitrile by
cyclocotrimerization. To this end, the 3- or 4-cyano-substituted
methyl benzoate or cinnamate esters are reacted with
trichloroacetonitrile and then the resultant
4,6-bistrichloromethyl-s-triazine-substituted methyl benzoate or
cinnamate ester is transesterified in a costly and inconvenient
manner involving in some instances multiple steps.
[0016] The problem addressed by the present invention was therefore
further that of providing a simple economical process for preparing
compounds (I) and precursors thereof.
[0017] This problem was solved by
a process for preparing para-disubstituted benzoic ester nitriles
of formula (IV)
##STR00002##
where R.sup.1 to R.sup.5 are each as defined under formula (I),
R.sup.6 is methyl or ethyl or isomeric propyl, and A is a catalyst
A, in a one-pot process wherein component (III) is used in excess,
components V, III and IV are distillatively removed in the stated
order in three steps by adjusting the pressure and the temperature,
and the difference in the boiling points of compounds (V) and (III)
and in the boiling points of compounds (III) and (IV) is not less
than 50.degree. C. in either case.
[0018] In said one-pot process, an ester of formula (II) where
R.sup.1 to R.sup.4 are each as defined under formula (I) and
R.sup.6 are methyl or ethyl or the isomeric propyls is converted in
the presence of an alcohol (III) where R.sup.5 is as defined above
and in the presence of a catalyst A, by heating in a first step at
an internal temperature of 100-150.degree. C. and a pressure of
300-1000 mbar with an excess of 1.1 to 10 equivalents of (III)
until the conversion of (II) is complete and distillatively
removing (V) from the reaction mixture and a subsequent step of
distillatively removing excess alcohol (III) at a overhead
temperature of 50-150.degree. C. and a pressure of 1-300 mbar
followed in a subsequent step by the distillation of product (IV)
at an overhead temperature of 100-250.degree. C. and a pressure of
0.01-1 mbar, leaving catalyst A behind in the pot.
[0019] Step 1 utilizes an internal temperature of 100-150.degree.
C., preferably 110-145.degree. C., more preferably 120-140.degree.
C. at a pressure of 300-1000 mbar, preferably 350-800 mbar, more
preferably 400-600 mbar with an excess of 1.1 to 10 equivalents of
(III), preferably of 1.2 to 5 equivalents, more preferably of 1.3
to 2 equivalents.
[0020] The second step utilizes an overhead temperature of
50-150.degree. C., preferably 60-125.degree. C., more preferably
70-100.degree. C. and a pressure of 1-300 mbar, preferably 3-100
mbar, more preferably 5-50 mbar.
[0021] The third step utilizes an overhead temperature of
100-250.degree. C., preferably of 125-240.degree. C., more
preferably of 150-230.degree. C. and a pressure of 0.01-1 mbar,
preferably of 0.02-0.5 mbar.
[0022] Alcohol (III) is suitably any compound having not less than
five and up to 20 aliphatic optionally halogen- or
oxygen-substituted carbon atoms bearing at least one methyl group.
Preference is given to compounds having not less than six and up to
15 aliphatic optionally halogen- or oxygen-substituted carbon atoms
bearing at least one methyl group. Particular preference is given
to compounds having not less than seven and up to 10 aliphatic
optionally halogen- or oxygen-substituted carbon atoms bearing at
least one methyl group.
[0023] Catalyst A is suitably, the fundamentally described in
Methoden der organischen Chemie (Houben-Weyl), Volume E5, 1, III.a)
.gamma., .gamma..sub.1 (pp. 702 ff, Pielartzik, Irmscher-Pielartzik
and Eicher), catalysts such as protic acids, basic catalysts
(alkanoates, anion exchangers), titanium(IV) and zirconium(IV)
alkanoates, alkoxytrialkyltin and also copper
alkanoate/triphenylphosphane complexes. Preferably, the catalysts
are in liquid form, have a higher boiling point than the desired
product and are effective in low concentration in ensuring rapid
and complete conversion. Higher titanium(IV) and zirconium(IV)
alkanoates are therefore particularly preferable. Particular
preference is given especially to higher titanium(IV) and zirconium
(IV) alkanoates wherein the alkanoate corresponds to that of
compound (III).
[0024] It is further preferable for catalyst A to be employed in an
amount of 0.0001 to 0.1 equivalent relative to employed compound
(II), more preferably of 0.0005 to 0.01 equivalent and yet more
preferably 0.001 to 0.005 equivalent.
[0025] The invention further provides a process for preparing
compounds (I) which comprises utilizing the one-pot process to
prepare para-disubstituted benzonitriles of formula (IV) in a first
step and reacting the resulting para-disubstituted benzonitrile
with trihaloacetonitrile in a second step.
[0026] The invention further provides a photopolymer formulation
comprising a photopolymerizable component and at least one compound
of formula (I).
[0027] In one embodiment of the photopolymer formulation, it
comprises matrix polymers, at least one writing monomer and a
photoinitiator system comprising at least one compound of formula
(I).
[0028] The matrix polymers of the photopolymer formulation
according to the present invention may be particularly in a
crosslinked state and more preferably in a three-dimensionally
crosslinked state.
[0029] It is also advantageous for the matrix polymers to be
polyurethanes, in which case the polyurethanes may be obtainable in
particular by reacting at least one polyisocyanate component a)
with at least one isocyanate-reactive component b).
[0030] The polyisocyanate component a) preferably comprises at
least one organic compound having at least two NCO groups. These
organic compounds may especially be monomeric di- and
triisocyanates, polyisocyanates and/or NCO-functional prepolymers.
The polyisocyanate component a) may also contain or consist of
mixtures of monomeric di- and triisocyanates, polyisocyanates
and/or NCO-functional prepolymers.
[0031] Monomeric di- and triisocyanates used may be any of the
compounds that are well known per se to those skilled in the art,
or mixtures thereof. These compounds may have aromatic,
araliphatic, aliphatic or cycloaliphatic structures. The monomeric
di- and triisocyanates may also comprise minor amounts of
monoisocyanates, i.e. organic compounds having one NCO group.
[0032] Examples of suitable monomeric di- and triisocyanates are
butane 1,4-diisocyanate, pentane 1,5-diisocyanate, hexane
1,6-diisocyanate (hexamethylene diisocyanate, HDI),
2,2,4-trimethylhexamethylene diisocyanate and/or
2,4,4-trimethylhexamethylene diisocyanate (TMDI), isophorone
diisocyanate (IPDI), 1,8-diisocyanato-4-(isocyanatomethyl)octane,
bis(4,4'-isocyanatocyclohexyl)methane and/or
bis(2',4-isocyanatocyclohexyl)methane and/or mixtures thereof
having any isomer content, cyclohexane 1,4-diisocyanate, the
isomeric bis(isocyanate-methyl)cyclohexanes, 2,4- and/or
2,6-diisocyanato-1-methylcyclohexane (hexahydrotolylene 2,4- and/or
2,6-diisocyanate, H.sub.6-TDI), phenylene 1,4-diisocyanate,
tolylene 2,4- and/or 2,6-diisocyanate (TDI), naphthylene
1,5-diisocyanate (NDI), diphenylmethane 2,4'- and/or
4,4'-diisocyanate (MDI), 1,3-bis(isocyanatomethyl)benzene (XDI)
and/or the analogous 1,4 isomers or any desired mixtures of the
aforementioned compounds.
[0033] Suitable polyisocyanates are compounds which have urethane,
urea, carbodiimide, acylurea, amide, isocyanurate, allophanate,
biuret, oxadiazinetrione, uretdione and/or iminooxadiazinedione
structures and are obtainable from the aforementioned di- or
triisocyanates.
[0034] More preferably, the polyisocyanates are oligomerized
aliphatic and/or cycloaliphatic di- or triisocyanates, it being
possible to use especially the above aliphatic and/or
cycloaliphatic di- or triisocyanates.
[0035] Very particular preference is given to polyisocyanates
having isocyanurate, uretdione and/or iminooxadiazinedione
structures, and biurets based on HDI or mixtures thereof.
[0036] Suitable prepolymers contain urethane and/or urea groups,
and optionally further structures formed through modification of
NCO groups as specified above. Prepolymers of this kind are
obtainable, for example, by reaction of the abovementioned
monomeric di- and triisocyanates and/or polyisocyanates al) with
isocyanate-reactive compounds b1).
[0037] Isocyanate-reactive compounds b1) used may be alcohols,
amino or mercapto compounds, preferably alcohols. These may
especially be polyols. Most preferably, isocyanate-reactive
compounds b1) used may be polyester polyols, polyether polyols,
polycarbonate polyols, poly(meth)acrylate polyols and/or
polyurethane polyols.
[0038] Suitable polyester polyols are, for example, linear
polyester diols or branched polyester polyols, which can be
obtained in a known manner by reaction of aliphatic, cycloaliphatic
or aromatic di- or polycarboxylic acids or anhydrides thereof with
polyhydric alcohols of OH functionality .gtoreq.2. Examples of
suitable di- or polycarboxylic acids are polybasic carboxylic acids
such as succinic acid, adipic acid, suberic acid, sebacic acid,
decanedicarboxylic acid, phthalic acid, terephthalic acid,
isophthalic acid, tetrahydrophthalic acid or trimellitic acid, and
acid anhydrides such as phthalic anhydride, trimellitic anhydride
or succinic anhydride, or any desired mixtures thereof. The
polyester polyols may also be based on natural raw materials such
as castor oil. It is likewise possible that the polyester polyols
are based on homo- or copolymers of lactones, which can preferably
be obtained by addition of lactones or lactone mixtures, such as
butyrolactone, .epsilon.-caprolactone and/or
methyl-.epsilon.-caprolactone onto hydroxy-functional compounds
such as polyhydric alcohols of OH functionality .gtoreq.2, for
example of the abovementioned type.
[0039] Examples of suitable alcohols are all polyhydric alcohols,
for example the C.sub.2-C.sub.12 diols, the isomeric
cyclohexanediols, glycerol or any desired mixtures thereof.
[0040] Suitable polycarbonate polyols are obtainable in a manner
known per se by reaction of organic carbonates or phosgene with
diols or diol mixtures.
[0041] Suitable organic carbonates are dimethyl, diethyl and
diphenyl carbonate.
[0042] Suitable diols or mixtures comprise the polyhydric alcohols
of OH functionality .gtoreq.2 mentioned per se in the context of
the polyester segments, preferably butane-1,4-diol, hexane-1,6-diol
and/or 3-methylpentanediol. It is also possible to convert
polyester polyols to polycarbonate polyols.
[0043] Suitable polyether polyols are polyaddition products,
optionally of blockwise structure, of cyclic ethers onto OH- or
NH-functional starter molecules.
[0044] Suitable cyclic ethers are, for example, styrene oxides,
ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide,
epichlorohydrin, and any desired mixtures thereof.
[0045] Starters used may be the polyhydric alcohols of OH
functionality .gtoreq.2 mentioned per se in the context of the
polyester polyols, and also primary or secondary amines and amino
alcohols.
[0046] Preferred polyether polyols are those of the aforementioned
type based exclusively on propylene oxide, or random or block
copolymers based on propylene oxide with further 1-alkylene oxides.
Particular preference is given to propylene oxide homopolymers and
random or block copolymers containing oxyethylene, oxypropylene
and/or oxybutylene units, where the proportion of the oxypropylene
units based on the total amount of all the oxyethylene,
oxypropylene and oxybutylene units amounts to at least 20% by
weight, preferably at least 45% by weight. Oxypropylene and
oxybutylene here encompasses all the respective linear and branched
C.sub.3 and C.sub.4 isomers.
[0047] Additionally suitable as constituents of the polyol
component b1), as polyfunctional, isocyanate-reactive compounds,
are also low molecular weight (i.e. with molecular weights
.ltoreq.500 g/mol), short-chain (i.e. containing 2 to 20 carbon
atoms), aliphatic, araliphatic or cycloaliphatic di-, tri- or
polyfunctional alcohols.
[0048] These may, for example, in addition to the abovementioned
compounds, be neopentyl glycol, 2-ethyl-2-butylpropanediol,
trimethylpentanediol, positionally isomeric diethyloctanediols,
cyclohexanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, 1,2-
and 1,4-cyclohexanediol, hydrogenated bisphenol A,
2,2-bis(4-hydroxycyclohexyl)propane or 2,2-dimethyl-3-hydroxypropyl
2,2-dimethyl-3-hydroxypropionate. Examples of suitable triols are
trimethylolethane, trimethylol-propane or glycerol. Suitable
higher-functionality alcohols are di(trimethylolpropane),
pentaerythritol, dipentaerythritol or sorbitol.
[0049] It is especially preferable when the polyol component is a
difunctional polyether, polyester, or a polyether-polyester block
copolyester or a polyether-polyester block copolymer having primary
OH functions.
[0050] It is likewise possible to use amines as isocyanate-reactive
compounds b1). Examples of suitable amines are ethylenediamine,
propylenediamine, diaminocyclohexane,
4,4'-dicyclohexylmethane-diamine, isophoronediamine (IPDA),
Bifunctional polyamines, for example the Jeffamines.RTM.,
amine-terminated polymers, especially having number-average molar
masses .ltoreq.10 000 g/mol. Mixtures of the aforementioned amines
can likewise be used.
[0051] It is likewise possible to use amino alcohols as
isocyanate-reactive compounds b1). Examples of suitable amino
alcohols are the isomeric aminoethanols, the isomeric
aminopropanols, the isomeric aminobutanols and the isomeric
aminohexanols, or any desired mixtures thereof.
[0052] All the aforementioned isocyanate-reactive compounds b1) can
be mixed with one another as desired.
[0053] It is also preferable when the isocyanate-reactive compounds
b1) have a number-average molar mass of .gtoreq.200 and .ltoreq.10
000 g/mol, further preferably .gtoreq.500 and .ltoreq.8000 g/mol
and most preferably .gtoreq.800 and .ltoreq.5000 g/mol. The OH
functionality of the polyols is preferably 1.5 to 6.0, more
preferably 1.8 to 4.0.
[0054] The prepolymers of the polyisocyanate component a) may
especially have a residual content of free monomeric di- and
triisocyanates of <1% by weight, more preferably <0.5% by
weight and most preferably <0.3% by weight.
[0055] It is optionally also possible that the polyisocyanate
component a) contains, entirely or in part, organic compound whose
NCO groups have been fully or partly reacted with blocking agents
known from coating technology. Example of blocking agents are
alcohols, lactams, oximes, malonic esters, pyrazoles, and amines,
for example butanone oxime, diisopropylamine, diethyl malonate,
ethyl acetoacetate, 3,5-dimethylpyrazole, .epsilon.-caprolactam, or
mixtures thereof.
[0056] It is especially preferable when the polyisocyanate
component a) comprises compounds having aliphatically bonded NCO
groups, aliphatically bonded NCO groups being understood to mean
those groups that are bonded to a primary carbon atom. The
isocyanate-reactive component b) preferably comprises at least one
organic compound having an average of at least 1.5 and preferably 2
to 3 isocyanate-reactive groups. In the context of the present
invention, isocyanate-reactive groups are regarded as being
preferably hydroxyl, amino or mercapto groups.
[0057] The isocyanate-reactive component may especially comprise
compounds having a numerical average of at least 1.5 and preferably
2 to 3 isocyanate-reactive groups.
[0058] Suitable polyfunctional isocyanate-reactive compounds of
component b) are for example the above-described compounds b1).
[0059] In a further preferred embodiment, the writing monomer c)
comprises or consists of at least one mono- and/or one
multifunctional writing monomer. Further preferably, the writing
monomer may comprise or consist of at least one mono- and/or one
multifunctional (meth)acrylate writing monomer. Most preferably,
the writing monomer may comprise or consist of at least one mono-
and/or one multifunctional urethane (meth)acrylate.
[0060] Suitable acrylate writing monomers are especially compounds
of the general formula (VI)
##STR00003##
in which n.gtoreq.1 and n.ltoreq.4 and R.sup.7 is a linear,
branched, cyclic or heterocyclic organic radical which is
unsubstituted or else optionally substituted by heteroatoms and/or
R.sup.8 is hydrogen or a linear, branched, cyclic or heterocyclic
organic radical which is unsubstituted or else optionally
substituted by heteroatoms. More preferably, R.sup.8 is hydrogen or
methyl and/or R.sup.7 is a linear, branched, cyclic or heterocyclic
organic radical which is unsubstituted or else optionally
substituted by heteroatoms.
[0061] Acrylates and methacrylates refer, respectively, to esters
of acrylic acid and methacrylic acid. Examples of acrylates and
methacrylates usable with preference are phenyl acrylate, phenyl
methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate,
phenoxyethoxyethyl acrylate, phenoxyethoxyethyl methacrylate,
phenylthioethyl acrylate, phenylthioethyl methacrylate, 2-naphthyl
acrylate, 2-naphthyl methacrylate, 1,4-bis(2-thionaphthyl)-2-butyl
acrylate, 1,4-bis(2-thionaphthyl)-2-butyl methacrylate, bisphenol A
diacrylate, bisphenol A dimethacrylate, and the ethoxylated
analogue compounds thereof, N-carbazolyl acrylates.
[0062] Urethane acrylates are understood to mean compounds having
at least one acrylic ester group and at least one urethane bond.
Compounds of this kind can be obtained, for example, by reacting a
hydroxy-functional acrylate or methacrylate with an
isocyanate-functional compound.
[0063] Examples of isocyanate-functional compounds usable for this
purpose are monoisocyanates, and the monomeric diisocyanates,
triisocyanates and/or polyisocyanates mentioned under a). Examples
of suitable monoisocyanates are phenyl isocyanate, the isomeric
methylthiophenyl isocyanates. Di-, tri- or polyisocyanates have
been mentioned above, and also triphenylmethane
4,4',4''-triisocyanate and tris(p-isocyanatophenyl) thiophosphate
or derivatives thereof with urethane, urea, carbodiimide, acylurea,
isocyanurate, allophanate, biuret, oxadiazinetrione, uretdione,
iminooxadiazinedione structure and mixtures thereof. Preference is
given to aromatic di-, tri- or polyisocyanates.
[0064] Useful hydroxy-functional acrylates or methacrylates for the
preparation of urethane acrylates include, for example, compounds
such as 2-hydroxyethyl (meth)acrylate, polyethylene oxide
mono(meth)acrylates, polypropylene oxide mono(meth)acrylates,
polyalkylene oxide mono(meth)acrylates,
poly(.epsilon.-caprolactone) mono(meth)acrylates, for example
Tone.RTM. M100 (Dow, Schwalbach, DE), 2-hydroxypropyl
(meth)acrylate, 4-hydroxybutyl (meth)acrylate,
3-hydroxy-2,2-dimethylpropyl (meth)acrylate, hydroxypropyl
(meth)acrylate, 2-hydroxy-3-phenoxypropyl acrylate, the
hydroxy-functional mono-, di- or tetraacrylates of polyhydric
alcohols such as trimethylolpropane, glycerol, pentaerythritol,
dipentaerythritol, ethoxylated, propoxylated or alkoxylated
trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol or
the technical mixtures thereof. Preference is given to
2-hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl
acrylate and poly(.epsilon.-caprolactone) mono(meth)acrylate.
[0065] It is likewise possible to use the fundamentally known
hydroxyl-containing epoxy (meth)acrylates having OH contents of 20
to 300 mg KOH/g or hydroxyl-containing polyurethane (meth)acrylates
having OH contents of 20 to 300 mg KOH/g or acrylated polyacrylates
having OH contents of 20 to 300 mg KOH/g and mixtures thereof, and
mixtures with hydroxyl-containing unsaturated polyesters and
mixtures with polyester (meth)acrylates or mixtures of
hydroxyl-containing unsaturated polyesters with polyester
(meth)acrylates.
[0066] Preference is given especially to urethane acrylates
obtainable from the reaction of tris(p-isocyanatophenyl)
thiophosphate and/or m-methylthiophenyl isocyanate with
alcohol-functional acrylates such as hydroxyethyl (meth)acrylate,
hydroxypropyl (meth)acrylate and/or hydroxybutyl
(meth)acrylate.
[0067] It is likewise possible that the writing monomer comprises
or consists of further unsaturated compounds such as
.alpha.,.beta.-unsaturated carboxylic acid derivatives, for example
maleates, fumarates, maleimides, acrylamides, and also vinyl
ethers, propenyl ethers, allyl ethers and compounds containing
dicyclopentadienyl units, and also olefinically unsaturated
compounds, for example styrene, .alpha.-methylstyrene, vinyltoluene
and/or olefins.
[0068] Photoinitiators of component d) are compounds activatable
typically by means of actinic radiation, which can trigger
polymerization of the writing monomers. In the case of the
photoinitiators, a distinction can be made between unimolecular
(type I) and bimolecular (type II) initiators. In addition, they
are distinguished by their chemical nature as photoinitiators for
free-radical, anionic, cationic or mixed types of
polymerization.
[0069] Type I photoinitiators (Norrish type I) for free-radical
photopolymerization form free radicals on irradiation through
unimolecular bond scission. Examples of type I photoinitiators are
triazines, oximes, benzoin ethers, benzil ketals, bisimidazoles,
aroylphosphine oxides, sulphonium salts and iodonium salts.
[0070] Type II photoinitiators (Norrish type II) for free-radical
polymerization consist of a dye as sensitizer and a coinitiator,
and undergo a bimolecular reaction on irradiation with light
matched to the dye. First of all, the dye absorbs a photon and
transfers energy from an excited state to the coinitiator. The
latter releases the polymerization-triggering free radicals through
electron or proton transfer or direct hydrogen abstraction.
[0071] In the context of this invention, preference is given to
using type II photoinitiators.
[0072] Photoinitiator systems of this kind are described in
principle in EP 0 223 587 A and consist preferably of a mixture of
one or more dyes with ammonium alkylarylborate(s).
[0073] Suitable dyes which, together with an ammonium
alkylarylborate, form a type II photoinitiator are the cationic
dyes described in WO 2012062655, in combination with the anions
likewise described therein.
[0074] Cationic dyes are preferably understood to mean those from
the following classes: acridine dyes, xanthene dyes, thioxanthene
dyes, phenazine dyes, phenoxazine dyes, phenothiazine dyes,
tri(het)arylmethane dyes--especially diamino- and
triamino(het)arylmethane dyes, mono-, di-, tri- and
pentamethinecyanine dyes, hemicyanine dyes, externally cationic
merocyanine dyes, externally cationic neutrocyanine dyes,
zeromethine dyes--especially naphtholactam dyes, streptocyanine
dyes. Dyes of this kind are described, for example, in H. Berneth
in Ullmann's Encyclopedia of Industrial Chemistry, Azine Dyes,
Wiley-VCH Verlag, 2008, H. Berneth in Ullmann's Encyclopedia of
Industrial Chemistry, Methine Dyes and Pigments, Wiley-VCH Verlag,
2008, T. Gessner, U. Mayer in Ullmann's Encyclopedia of Industrial
Chemistry, Triarylmethane and Diarylmethane Dyes, Wiley-VCH Verlag,
2000.
[0075] Particular preference is given to phenazine dyes,
phenoxazine dyes, phenothiazine dyes, tri(het)arylmethane
dyes--especially diamino- and triamino(het)arylmethane dyes, mono-,
di-, tri- and pentamethinecyanine dyes, hemicyanine dyes,
zeromethine dyes--especially naphtholactam dyes, streptocyanine
dyes.
[0076] Examples of cationic dyes are Astrazon Orange G, Basic Blue
3, Basic Orange 22, Basic Red 13, Basic Violet 7, Methylene Blue,
New Methylene Blue, Azure A,
2,4-diphenyl-6-(4-methoxyphenyl)pyrylium, Safranin O, Astraphloxin,
Brilliant Green, Crystal Violet, Ethyl Violet and thionine.
[0077] Preferred anions are especially C.sub.8- to
C.sub.25-alkanesulphonate, preferably C.sub.13- to
C.sub.25-alkanesulphonate, C.sub.3- to
C.sub.18-perfluoroalkanesulphonate, C.sub.4- to
C.sub.18-perfluoroalkanesulphonate bearing at least 3 hydrogen
atoms in the alkyl chain, C.sub.9- to C.sub.25-alkanoate, C.sub.9-
to C.sub.25-alkenoate, C.sub.8- to C.sub.25-alkylsulphate,
preferably C.sub.13- to C.sub.25-alkylsulphate, C.sub.8- to
C.sub.25-alkenylsulphate, preferably C.sub.13- to
C.sub.25-alkenylsulphate, C.sub.3- to
C.sub.18-perfluoroalkylsulphate, C.sub.4- to
C.sub.18-perfluoroalkylsulphate bearing at least 3 hydrogen atoms
in the alkyl chain, polyether sulphates based on at least 4
equivalents of ethylene oxide and/or 4 equivalents of propylene
oxide, bis(C.sub.4- to C.sub.25-alkyl, C.sub.5- to
C.sub.7-cycloalkyl, C.sub.3- to C.sub.8-alkenyl or C.sub.7- to
C.sub.11-aralkyl)sulphosuccinate, bis-C.sub.2- to
C.sub.10-alkylsulphosuccinate substituted by at least 8 fluorine
atoms, C.sub.8- to C.sub.25-alkylsulphoacetates, benzenesulphonate
substituted by at least one radical from the group of halogen,
C.sub.4- to C.sub.25-alkyl, perfluoro-C.sub.1- to C.sub.8-alkyl
and/or C.sub.1- to C.sub.12-alkoxycarbonyl, naphthalene- or
biphenylsulphonate optionally substituted by nitro, cyano,
hydroxyl, C.sub.1- to C.sub.25-alkyl, C.sub.1- to C.sub.12-alkoxy,
amino, C.sub.1- to C.sub.12-alkoxycarbonyl or chlorine, benzene-,
naphthalene- or biphenyldisulphonate optionally substituted by
nitro, cyano, hydroxyl, C.sub.1- to C.sub.25-alkyl, C.sub.1- to
C.sub.12-alkoxy, C.sub.1- to C.sub.12-alkoxycarbonyl or chlorine,
benzoate substituted by dinitro, C.sub.6- to C.sub.25-alkyl,
C.sub.4- to C.sub.12-alkoxycarbonyl, benzoyl, chlorobenzoyl or
toluoyl, the anion of naphthalenedicarboxylic acid, diphenyl ether
disulphonate, sulphonated or sulphated, optionally at least
monounsaturated C.sub.8- to C.sub.25-fatty acid esters of aliphatic
C.sub.1- to C.sub.8-alcohols or glycerol, bis(sulpho-C.sub.2- to
C.sub.6-alkyl) C.sub.3- to C.sub.12-alkanedicarboxylates,
bis(sulpho-C.sub.2- to C.sub.6-alkyl) itaconates, (sulpho-C.sub.2-
to C.sub.6-alkyl) C.sub.6- to C.sub.18-alkanecarboxylates,
(sulpho-C.sub.2- to C.sub.6-alkyl) acrylates or methacrylates,
triscatechol phosphate optionally substituted by up to 12 halogen
radicals, an anion from the group of tetraphenylborate,
cyanotriphenylborate, tetraphenoxyborate, C.sub.4- to
C.sub.12-alkyltriphenylborate, wherein the phenyl or phenoxy
radicals may be substituted by halogen, C.sub.1- to C.sub.4-alkyl
and/or C.sub.1- to C.sub.4-alkoxy, C.sub.4- to
C.sub.12-alkyltrinaphthylborate, tetra-C.sub.1- to
C.sub.20-alkoxyborate, 7,8- or 7,9-dicarba-nido-undecaborate(1-) or
(2-), which are optionally substituted on the boron and/or carbon
atoms by one or two C.sub.1- to C.sub.12-alkyl or phenyl groups,
dodecahydrodicarbadodecaborate(2-) or B--C.sub.1- to
C.sub.12-alkyl-C-phenyldodecahydrodicarbadodecaborate(1-), where,
in the case of polyvalent anions such as naphthalenedisulphonate,
A.sup.- represents one equivalent of this anion, and where the
alkane and alkyl groups may be branched and/or may be substituted
by halogen, cyano, methoxy, ethoxy, methoxycarbonyl or
ethoxycarbonyl.
[0078] It is also preferable when the anion A.sup.- of the dye has
an AClogP in the range from 1 to 30, more preferably in the range
from 1 to 12 and especially preferably in the range from 1 to 6.5.
AClogP is computed after J. Comput. Aid. [mol %] Des. 2005, 19,
453; Virtual Computational Chemistry Laboratory,
http://www.vcclab.org.
[0079] Suitable ammonium alkylarylborates are, for example
(Cunningham et al., RadTech'98 North America UV/EB Conference
Proceedings, Chicago, Apr. 19-22, 1998): tetrabutylammonium
triphenylhexylborate, tetrabutylammonium triphenylbutylborate,
tetrabutylammonium trinaphthylhexylb orate, tetrabutylammonium
tris(4-tert-butyl)phenylbutylborate, tetrabutylammonium
tris(3-fluorophenyl)hexylborate hexylborate ([191726-69-9], CGI
7460, product from BASF SE, Basle, Switzerland),
1-methyl-3-octylimidazolium dipentyldiphenylborate and
tetrabutylammonium tris(3-chloro-4-methylphenyl)hexylborate
([1147315-11-4], CGI 909, product from BASF SE, Basle,
Switzerland).
[0080] It may be advantageous to use mixtures of these
photoinitiators. According to the radiation source used, the type
and concentration of photoinitiator has to be adjusted in the
manner known to those skilled in the art. Further details are
described, for example, in P. K. T. Oldring (Ed.), Chemistry &
Technology of UV & EB Formulations For Coatings, Inks &
Paints, vol. 3, 1991, SITA Technology, London, p. 61-328.
[0081] It is most preferable when the photoinitiator comprises a
combination of dyes whose absorption spectra at least partly cover
the spectral range from 400 to 800 nm, with at least one
coinitiator matched to the dyes.
[0082] It is also preferable when at least one photoinitiator
suitable for a laser light colour selected from blue, yellow, green
and red is present in the photopolymer formulation.
[0083] It is also further preferable when the photopolymer
formulation contains one suitable photoinitiator each for at least
two laser light colours selected from blue, green and red.
[0084] Finally, it is most preferable when the photopolymer
formulation contains one suitable photoinitiator for each of the
laser light colours blue, green and red.
[0085] In a further preferred embodiment, the photopolymer
formulation additionally contains urethanes as additives, in which
case the urethanes may especially be substituted by at least one
fluorine atom.
[0086] Preferably, the urethanes may have the general formula
(VII)
##STR00004##
in which m.gtoreq.1 and m.ltoreq.8 and R.sup.9, R.sup.10 and
R.sup.11 are linear, branched, cyclic or heterocyclic organic
radicals which are unsubstituted or else optionally substituted by
heteroatoms and/or R.sup.10, R.sup.11 are, each independently
hydrogen, in which case preferably at least one of the R.sup.9,
R.sup.10, R.sup.11 radicals is substituted by at least one fluorine
atom and, more preferably, R.sup.9 is an organic radical having at
least one fluorine atom. More preferably, R.sup.10 is a linear,
branched, cyclic or heterocyclic organic radical which is
unsubstituted or else optionally substituted by heteroatoms, for
example fluorine.
[0087] The present invention further provides a photopolymer
comprising a photopolymer formulation, in particular comprising
matrix polymers, writing monomer and a photoinitiator system and
further comprising a compound of formula (I).
[0088] The matrix polymers of the photopolymer formulation
according to the present invention may be particularly in a
crosslinked state and more preferably in a three-dimensionally
crosslinked state.
[0089] It is also advantageous for the matrix polymers to be
polyurethanes, in which case the polyurethanes may be obtainable in
particular by reacting at least one polyisocyanate component with
at least one isocyanate-reactive component.
[0090] The above remarks concerning further preferred embodiments
of the photopolymer formulation according to the present invention
also apply mutatis mutandis to the photopolymer of the present
invention.
[0091] The invention also provides a holographic medium
particularly in the form of a film comprising a photopolymer of the
present invention or obtainable by using a photopolymer formulation
of the present invention. The invention yet further provides for
the use of a photopolymer formulation of the present invention in
the production of holographic media.
[0092] In one preferred embodiment of the holographic medium
according to the present invention, holographic information has
been exposed into same.
[0093] The inventive holographic media can be processed into
holograms by means of appropriate exposure processes for optical
applications over the entire visible and in the near UV range
(300-800 nm). Visual holograms include all holograms which can be
recorded by methods known to those skilled in the art. These
include in-line (Gabor) holograms, off-axis holograms,
full-aperture transfer holograms, white light transmission
holograms ("rainbow holograms"), Denisyuk holograms, off-axis
reflection holograms, edge-lit holograms and holographic
stereograms. Preference is given to reflection holograms, Denisyuk
holograms, transmission holograms.
[0094] Possible optical functions of the holograms which can be
produced with the inventive photopolymer formulations correspond to
the optical functions of light elements such as lenses, mirrors,
deflecting mirrors, filters, diffuser lenses, diffraction elements,
diffusers light guides, waveguides, projection lenses and/or masks.
It is likewise possible for combinations of these optical functions
to be combined in one hologram independently of each other. These
optical elements frequently have a frequency selectivity according
to how the holograms have been exposed and the dimensions of the
hologram.
[0095] In addition, by means of the inventive media, it is also
possible to produce holographic images or representations, for
example for personal portraits, biometric representations in
security documents, or generally of images or image structures for
advertising, security labels, brand protection, branding, labels,
design elements, decorations, illustrations, collectable cards,
images and the like, and also images which can represent digital
data, including in combination with the products detailed above.
Holographic images can have the impression of a three-dimensional
image, but they may also represent image sequences, short films or
a number of different objects according to the angle from which and
the light source with which (including moving light sources) etc.
they are illuminated. Because of this variety of possible designs,
holograms, especially volume holograms, constitute an attractive
technical solution for the abovementioned application.
[0096] The present invention accordingly further provides for the
use of an inventive holographic medium for recording of in-line,
off-axis, full-aperture transfer, white light transmission,
Denisyuk, off-axis reflection or edge-lit holograms and also of
holographic stereograms, in particular for production of optical
elements, images or image depictions.
[0097] The invention likewise provides holograms comprising the
holographic medium of the present invention.
[0098] The invention likewise provides a process for producing a
hologram wherein pulsed laser radiation is used to expose the
medium.
[0099] In one embodiment of the process according to the present
invention, the pulse duration is .ltoreq.200 ns, preferably
.ltoreq.100 ns, more preferably .ltoreq.60 ns. The pulse duration
must not be less than 0.5 ns. A pulse duration of 4 ns is
particularly preferable.
[0100] The present invention further also provides a process for
producing a holographic medium by using a photopolymer formulation
of the present invention.
[0101] The photopolymer formulations can especially be used for
production of holographic media in the form of a film. In this
case, a ply of a material or material composite transparent to
light within the visible spectral range (transmission greater than
85% within the wavelength range from 400 to 780 nm) as carrier
substrate is coated on one or both sides, and a cover layer is
optionally applied to the photopolymer ply or plies.
[0102] Preferred materials or material composites for the carrier
substrate are based on polycarbonate (PC), polyethylene
terephthalate (PET), polybutylene terephthalate, polyethylene,
polypropylene, cellulose acetate, cellulose hydrate, cellulose
nitrate, cycloolefin polymers, polystyrene, polyepoxides,
polysulphone, cellulose triacetate (CTA), polyamide,
polymethylmethacrylate, polyvinyl chloride, polyvinyl butyral or
polydicyclopentadiene or mixtures thereof. They are more preferably
based on PC, PET and CTA. Material composites may be film laminates
or coextrudates. Preferred material composites are duplex and
triplex films formed according to one of the schemes A/B, A/B/A or
A/B/C. Particular preference is given to PC/PET, PET/PC/PET and
PC/TPU (TPU=thermoplastic polyurethane).
[0103] The materials or material composites of the carrier
substrate may be given an antiadhesive, antistatic, hydrophobized
or hydrophilized finish on one or both sides. The modifications
mentioned serve the purpose, on the side facing the photopolymer,
of making the photopolymer detachable without destruction from the
carrier substrate. Modification of the opposite side of the carrier
substrate from the photopolymer serves to ensure that the inventive
media satisfy specific mechanical demands which exist, for example,
in the case of processing in roll laminators, especially in
roll-to-roll processes.
[0104] The examples which follow serve to elucidate the invention
exemplarily without it being restricted thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0105] FIG. 1 shows the schematic set-up of the coating range.
[0106] FIG. 2 shows a measuring arrangement to obtain holographic
properties.
[0107] FIG. 3 shows a transmission spectrum including collapse for
the hologram of the bleached sample.
EXAMPLES
Test Methods:
OH Number:
[0108] Reported OH numbers were determined to DIN 53240-2.
NCO Value:
[0109] Reported NCO values (isocyanate contents) were determined to
DIN EN ISO 11909.
Determination of Overhead Temperature:
[0110] The overhead temperature was determined in degrees Celsius
(.degree. C.) using a 4-20 mA calibrated transmitter and a PT100
thermocouple installed in the boiling equilibrium above a packed
column.
Determination of Internal Temperature:
[0111] The internal temperature was determined in degrees Celsius
(.degree. C.) using a 4-20 mA calibrated transmitter and a PT100
thermocouple installed in the reaction space.
Determination of Diffraction Efficiency in Pulsed Exposure:
[0112] To determine the diffraction efficiency in pulsed exposure,
the Denisyuk hologram of a mirror was recorded in a sample
consisting of a glass plate laminated with a photopolymer film. The
substrate of the photopolymer film and the glass substrate faced
laser source and the mirror, respectively. The sample was exposed
with its planar face perpendicular to the laser beam. The distance
between the sample and the mirror was 3 cm.
[0113] The laser used was a Brilliant b pulsed laser from Quantel
of France. The laser in question was a Q-switched Nd-YAG laser
equipped with a module for frequency doubling to 532 nm. The single
frequency mode was guaranteed by a seed laser. Coherence length was
arithmetically about 1 m. Pulse duration was 4 ns and average power
output was 3 watts at a pulse repetition rate of 10 Hz.
[0114] The electronically controlled shutter was used to ensure a
single pulse exposure. The waveplate made it possible to rotate the
polarization plane of the laser light and the subsequent polarizer
was used to reflect the S-polarized portion of the laser light in
the direction of the sample. The exposed area was adjusted by beam
expansion. The waveplate and the beam expander were adjusted such
that the sample was given an exposure dose of 100
mJ/cm.sup.2/pulse.
[0115] To determine the diffraction efficiency, the samples were
each exposed with exactly one pulse. After exposure, the sample was
bleached on a light table.
[0116] A transmission spectrum was measured through the hologram of
the bleached sample. An HR4000 spectrometer from Ocean Optics was
used. The sample was placed perpendicularly to the light beam. The
transmission spectrum showed a transmission collapse at a
wavelength at which the Bragg condition was satisfied. The depth of
the transmission collapse to the base line was evaluated as the
diffraction efficiency DE of the Denisyuk hologram of the mirror
(FIG. 3).
Substances:
[0117] The solvents used were obtained commercially. [0118]
Desmorapid Z Dibutyltin dilaurate [77-58-7], product from Bayer
MaterialScience AG, Leverkusen, Germany. [0119] Desmodur.RTM. N
3900 Product from Bayer MaterialScience AG, Leverkusen, Germany,
hexane diisocyanate-based polyisocyanate, proportion of
iminooxadiazinedione at least 30%, NCO content: 23.5%. [0120]
Fomrez UL 28 Urethanization catalyst, commercial product of
Momentive Performance Chemicals, Wilton, Conn., USA. [0121] Sodium
bis(2-ethylhexyl)-[45297-26-5] is available from Aldrich Chemie,
Steinheim. sulphosuccinate
Compound of the Formula (I)
Example 1: 2-Ethylhexyl
4-[4,6-bis(trichloromethyl)-1,3,5-triazin-2-yl]benzoate
Preparation of 2-Ethylhexyl 4-Cyanobenzoate by the One-Pot Process
of the Invention
[0122] A 25 L jacketed enamelled tank fitted with a glass head, a
mechanical stirrer, a distillation head with reflux divider and
metering and vacuum units was initially charged under an inert
atmosphere with 10.91 kg of 2-ethylhexanol (1.5 eq., [104-76-7]
Aldrich Chemie, Steinheim, Germany) at 25.degree. C. and 9.00 kg of
methyl 4-cyanobenzoate (1.0 eq., [1129-35-7] ABCR GmbH & CO.
KG, Karlsruhe, Germany) were admixed. To this mixture was added 32
g of titanium(IV) 2-ethylhexoxide (0.001 eq., [1070-10-6] ABCR GmbH
& CO. KG, Karlsruhe, Germany) and the internal temperature was
raised to and maintained at 130.degree. C. for 2 h. During this
period, about 1.2 kg of methanol (about 2/3 of the theoretical
amount) were distilled. The receiver was emptied and the pressure
was reduced to 500 mbar. The internal temperature was raised to and
maintained at 135.degree. C. for a further 4 h. At this point in
time, no further methanol was collected and, according to analysis
by gas chromatography, the reaction mixture no longer contained any
methyl 4-cyanobenzoate. The internal temperature was lowered to
100.degree. C., the receiver was emptied and a pressure of 10 mbar
was applied. 2-Ethylhexanol was collected at a pressure of 8.8-9.6
mbar and an overhead temperature of 65.5-68.5.degree. C. in an
amount of 3.14 kg. After renewed emptying of the receiver, the
internal temperature was raised to 185-190.degree. C. and a
pressure of 0.25 mbar was applied. 2-Ethylhexyl 4-cyanobenzoate was
obtained at an overhead temperature of 150.0-155.0.degree. C. as a
colourless oil in an amount of 14.04 kg (96.9% of theory).
[0123] GC (column used: 60m Optima-5 HT MS, temperature programme:
T.sub.start=70.degree. C. for 10 min, then at 3.degree. C./min to
300.degree. C., 300.degree. C. for 5 min) integration in area
percent: 0.11% of 2-ethylhexanol, 99.54% of 2-ethylhexyl
4-cyanobenzoate.
[0124] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.19-8.08 (m, 2H),
7.79-7.71 (m, 2H), 4.35-4.18 (m, 2H), 1.81-1.65 (kept, J=6.2 Hz,
1H), 1.53-1.23 (m, 8H), 1.01-0.86 (m, 6H).
Preparation of 2-ethylhexyl
4-[4,6-bis(trichloromethyl)-1,3,5-triazin-2-yl]benzoate
[0125] A 1 L three-necked flask was initially charged with 150.2 g
of 2-ethylhexyl 4-cyanobenzoate and 334.4 g of
trichloroacetonitrile, and this initial charge was admixed with
15.4 g of aluminium bromide at 0.degree. C. To this mixture was
added dried HCl (g) to the point of saturation and then the
temperature was raised to 50.degree. C. over 4 h and maintained
there for 2 h. Excess HCl (g) was expelled with nitrogen and the
reaction mixture was diluted with 100 mL of toluene and kept at
-20.degree. C. for 24 h. By-produced
tris(trichloromethyl)-1,3,5-triazine separates out quantitatively
at this temperature and the supernatant solution was decanted. The
solvent was removed under reduced pressure to leave 256 g of a
slightly pale yellow oil.
[0126] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.81-8.71 (m, 2H),
8.28-8.20 (m, 2H), 4.36-4.25 (m, 2H), 1.81-1.70 (dt, J=12.2, 6.1
Hz, 1H), 1.53-1.39 (m, 11H), 1.39-1.27 (m, 4H), 1.05-0.95 (t, J=7.5
Hz, 3H), 0.95-0.87 (m, 3H).
[0127] .sup.13C NMR (101 MHz, CDCl.sub.3) .delta. 175.42, 174.09,
165.72, 137.00, 135.85, 130.15, 129.97, 94.74, 67.98, 38.93, 30.61,
28.99, 26.90, 24.03, 22.96, 14.03, 11.11.
Preparation of Further Components for the Photopolymer
Formulation
Preparation of Polyol 1
[0128] A 1 l flask was initially charged with 0.18 g of tin
octoate, 374.8 g of .epsilon.-caprolactone and 374.8 g of a
difunctional polytetrahydrofuran polyether polyol (equivalent
weight 500 g/mol OH), which were heated to 120.degree. C. and kept
at this temperature until the solids content (proportion of
nonvolatile constituents) was 99.5% by weight or higher.
Subsequently, the mixture was cooled and the product was obtained
as a waxy solid.
Preparation of Urethane Acrylate 1 (Writing Monomer):
Phosphorothioyltris(Oxybenzene-4,1-diylcarbamoyloxyethane-2,1-diyl)
trisacrylate
[0129] A 500 mL round-bottom flask was initially charged with 0.1 g
of 2,6-di-tert-butyl-4-methylphenol, 0.05 g of dibutyltin dilaurate
(Desmorapid.RTM. Z, Bayer MaterialScience AG, Leverkusen, Germany)
and 213.07 g of a 27% solution of tris(p-isocyanatophenyl)
thiophosphate in ethyl acetate (Desmodur.RTM. RFE, product from
Bayer MaterialScience AG, Leverkusen, Germany), which were heated
to 60.degree. C. Subsequently, 42.37 g of 2-hydroxyethyl acrylate
were added dropwise and the mixture was still kept at 60.degree. C.
until the isocyanate content had fallen below 0.1%. This was
followed by cooling and complete removal of the ethyl acetate under
reduced pressure. The product was obtained as a semicrystalline
solid.
Preparation of Urethane Acrylate 2 (Writing Monomer):
2-({[3-(Methylsulphanyl)phenyl]-carbamoyl}oxy)ethyl
prop-2-enoate
[0130] A 100 mL round-bottom flask was initially charged with 0.02
g of 2,6-di-tert-butyl-4-methylphenol, 0.01 g of Desmorapid.RTM. Z,
11.7 g of 3-(methylthio)phenyl isocyanate [28479-1-8], and the
mixture was heated to 60.degree. C. Subsequently, 8.2 g of
2-hydroxyethyl acrylate were added dropwise and the mixture was
still kept at 60.degree. C. until the isocyanate content had fallen
below 0.1%. This was followed by cooling. The product was obtained
as a colourless liquid.
Preparation of additive 1
bis(2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl)(2,2,4-trimethyl-hexane-1,-
6-diyl) biscarbamate
[0131] A 50 mL round-bottom flask was initially charged with 0.02 g
of Desmorapid.RTM. Z and 3.6 g of 2,4,4-trimethylhexane
1,6-diisocyanate (TMDI), and the mixture was heated to 60.degree.
C. Subsequently, 11.9 g of
2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptan-1-ol were added dropwise
and the mixture was still kept at 60.degree. C. until the
isocyanate content had fallen below 0.1%. This was followed by
cooling. The product was obtained as a colourless oil.
Preparation of Dye 1:
[0132] In a procedure similar to Example 6 of DE 1 073 662, 6.98 g
of the cyanomethylene base of the formula
##STR00005##
and 6.16 g of the aldehyde of the formula
##STR00006##
in 30 mL of anhydrous toluene were gradually admixed with 3.57 g of
thionyl chloride under agitation. This was followed by stirring at
100.degree. C. for 1 h and cooling. 50 mL of toluene were added and
the dye was filtered off with suction. The dye was stirred up three
times with 30 mL of toluene each time and again filtered off with
suction each time. After drying at 50.degree. C. under reduced
pressure, the red dye was substantially dissolved in 100 mL of
water. A solution of 12.38 g of sodium
bis(2-ethylhexyl)sulphosuccinate in 100 mL of butyl acetate was
added. The two-phase mixture was stirred for 1 h and then
transferred into a separating funnel. The aqueous phase was dropped
and the organic phase was washed four times with 40 mL of water.
After removal of the last wash liquor, the organic phase was
diluted with 250 mL of butyl acetate and distilled water-free in a
rotary evaporator under reduced pressure. About 200 mL of butyl
acetate were also distilled off in the process, to finally leave
150.1 g of a red solution of the dye of the formula
##STR00007##
in butyl acetate, said solution being storage stable.
[0133] A sample was taken and the remaining solvent was stripped
off under reduced pressure. After drying at 50.degree. C. under
reduced pressure, the dye was obtained as a red resinous substance.
.lamda..sub.max (in CH.sub.3CN)=498 nm and 523 nm, .epsilon.=89580
(at 498 nm) and 99423 L mol.sup.-1 cm.sup.-1 (at 523 nm) L
mol.sup.-1 cm.sup.-1. These spectroscopic data showed the
concentration of the above solution to be 10.0%.
Production of Media to Determine the Holographic Properties
Production of Holographic Media on a Foil-Coating Range
[0134] A continuous process will now be described for producing
holographic media in the form of films from inventive and
non-inventive photopolymer formulations.
[0135] The production process was carried out using the
foil-coating range depicted in FIG. 1, wherein the individual
component parts are assigned the following reference symbols. FIG.
1 shows the schematic set-up of the coating range used. In said
figure, the individual component parts have the following reference
signs: [0136] 1, 1' stock reservoir vessel [0137] 2, 2' metering
device [0138] 3, 3' vacuum degassing device [0139] 4, 4' filter
[0140] 5 static mixer [0141] 6 coating device [0142] 7 circulating
air dryer [0143] 8 carrier substrate [0144] 9 covering layer
Example Medium 1
[0145] To prepare the photopolymer formulation, 39.42 g of polyol 1
were incrementally admixed with a mixture of 15.00 g of urethane
acrylate 1 and 15.00 g of urethane acrylate 2, 11.25 g of additive
1, 0.075 g of Example 1, 0.75 g of CGI 909, 0.68 g of BYK.RTM. 310
surfactant, 0.038 g of Fomrez UL-28 and 23.65 g of ethyl acetate
and homogenized. The mixture was subsequently admixed with 1.50 g
of a 10% solution of dye 1 in ethyl acetate in the dark and
homogenized so that a clear solution was obtained. If necessary,
the formulation was briefly heated at 60.degree. C. to speed up the
dissolving of the materials used. This mixture was imported into
one of the two stock reservoir vessels 1 of the coating range. Into
the second stock reservoir vessel 1' was filled the polyisocyanate
component (Desmodur.RTM. N 3900, commercial product of Bayer
MaterialScience AG, Leverkusen, Germany, polyisocyanate based on
hexane diisocyanate, at least 30% proportion of
iminooxadiazinedione, NCO content: 23.5%). The two components were
then each fed through the metering devices 2 in a ratio of 942.2
(component mixture) to 57.8 (isocyanate) to the vacuum degassing
device 3 and degassed. From there they were then each passed
through the filters 4 into the static mixer 5, where the components
were mixed to form the photopolymer formulation. The liquid
material obtained was then sent to the coating device 6.
[0146] The coating device 6 in the present case was a doctor blade
system known to a person skilled in the art. Alternatively,
however, it is also possible to use a slot die. Said coating device
6 was used to apply the photopolymer formulation at a processing
temperature of 20.degree. C. to a carrier substrate 8 in the form
of a 36 .mu.m thick polyethylene terephthalate foil and dried in a
circulating air dryer 7 at a crosslinking temperature of 80.degree.
C. for 5.8 minutes to obtain a medium in the form of a film which
was then provided a 40 .mu.m thick polyethylene foil as covering
layer 9 and wound up.
[0147] The desired target layer thickness of the film was
preferably between 1 and 60 .mu.m, preferably from 5 to 25 .mu.m,
more preferably from 10 to 15 nm.
[0148] The production speed was preferably in the range from 0.2
m/min to 300 m/min and more preferably in the range from 1.0 m/min
to 50 m/min.
[0149] The layer thickness obtained for the film was 12 .mu.m.+-.1
nm.
Comparative Medium I
[0150] Comparative medium I was without Example 1 as described
above.
Holographic Testing:
[0151] The media obtained as described were tested for their
holographic properties by using a measuring arrangement as per FIG.
2 in the manner described above (Determination of diffraction
efficiency in pulsed exposure). The following measurements were
obtained for DE at a fixed dose of 100 mJ/cm.sup.2:
TABLE-US-00001 TABLE 1 Holographic assessment of selected examples
Example medium Single pulse DE [%] 1 49
TABLE-US-00002 TABLE 2 Holographic assessment of selected
comparative media Comparative medium Single pulse DE [%] I 2%
[0152] The value found for Example medium 1 shows that the
inventive formula (I) compounds used in the photopolymer
formulations are very useful in holographic media to be exposed
with pulsed laser. Comparative medium I is free from any formula
(I) compound according to the invention and is unsuitable for use
in holographic media to be exposed with pulsed laser.
* * * * *
References