CA1328330C - Photocrosslinkable liquid crystalline polymers - Google Patents
Photocrosslinkable liquid crystalline polymersInfo
- Publication number
- CA1328330C CA1328330C CA000518726A CA518726A CA1328330C CA 1328330 C CA1328330 C CA 1328330C CA 000518726 A CA000518726 A CA 000518726A CA 518726 A CA518726 A CA 518726A CA 1328330 C CA1328330 C CA 1328330C
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- CA
- Canada
- Prior art keywords
- polymer
- liquid crystalline
- light
- group
- sensitive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K19/00—Liquid crystal materials
- C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
- C09K19/38—Polymers
- C09K19/3833—Polymers with mesogenic groups in the side chain
- C09K19/3842—Polyvinyl derivatives
- C09K19/3852—Poly(meth)acrylate derivatives
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
- G03F7/0388—Macromolecular compounds which are rendered insoluble or differentially wettable with ethylenic or acetylenic bands in the side chains of the photopolymer
Abstract
NOVEL PHOTCROSSLINKABLE LIQUID CRYSTALLINE POLYMERS
Abstract of the Disclosure A photocrosslinkable liquid crystalline polymer comprising a vinyl backbone having from 60 to 100 mole percent of recurring pendant groups com-prising an alkyl or alkoxy light-sensitive cinnamate component connected to the vinyl backbone through a) a component which provides stiffness and rod-like character to the cinnamate component and b) a spacer group having from 7 to 14 atoms.
Abstract of the Disclosure A photocrosslinkable liquid crystalline polymer comprising a vinyl backbone having from 60 to 100 mole percent of recurring pendant groups com-prising an alkyl or alkoxy light-sensitive cinnamate component connected to the vinyl backbone through a) a component which provides stiffness and rod-like character to the cinnamate component and b) a spacer group having from 7 to 14 atoms.
Description
.
1 32833~
- --1-- ....
NOVEL PHOTOCROSSLINKABLE LIQUID CRYSTALLINE POLYMERS
Field of the Invention The present invention relates to novel photocrosslinkable liquid crystalline polymers and a method for their preparation and sn imaging element using the polymers.
_A KGROUND OF THE INVENTION
Photocrosslinkable polymers are known.
They have found many applications in lndustry. For example, photocrosslinkable polymers find many applicat~ons in the making of lithographic pl~tes and in photoresist applications. Many of the more useful photocrosslinkable polymers comprise, as a light-sensitive component, recurring cinnamate components. For example, polyvinyl cinnamate is formed by reacting polyvinyl alcohol wlth cinnamic acid. Such polymers are disclosed in U.S. Patent 3,817,876, U.S. Patent 4,230,817 and U.S. Patent 3,~33,746. :
In photolithographic and in photoresist applications, photocrosslinkable polymeric composi- ~ ;
tions are coated upon a su~table supporting surface such as a metal plate to form an imaging element.
Thereafter, the element is exposed to actinlc ~ 25 light. Exposure results in insolubilization of the -~ polymer in the exposed areas and solubilization of the polymer in the unexposed areas. The unexposed ;~
areas of the polymer coating can be removed by means of sultable solvent~ to leave a relief image.
The photosensitized crosslinking of amor-phous polymers such as those described in the bove-mentioned U.S. Patents generally ~how quantum yields of dimerizatlon of about 4 percent. Sensi-tizatlon of such polymers by ketocoumarins proceeds 35~ generally by triplet-triplet energy transfer. There '~
': :~
13~8330 are known to be several energy wsstage steps compet-ing with triplet-triplet energy transfer. In the case of amorphous cinnamate polymers, the triplet energy migrates step-wise from one cinnamate com-ponent to the next until it decays, or reaches an appropriate ~ite for promoting crosslinking. An appropriste site in this regard is a double bond of the cinnamate components aligned parallel to each other, and approximately 4 angstoms apart. The triplet energy visits an average of 100 to 200 sites before an appropriate site is found. Since the lifetime of the triplet excited state is only 10 nanoseconds, the decay to the ground state dominates ;:~
over excimer formation which results in crosslinking. ~-It would be extremely important and useful to design polymers which would make better use of -triplet-triplet energy transfer which occurs with ketocoumarin sensitizatlon.
SUMMARY OF THE INVENTION
The present invention provides a photo-crosslinkable liquid crystalline polymer comprising a vinyl backbone having from 60 to 100 mole percent of recurring pendant groups comprising an alkyl or alkoxy substltuted light-sensitive cinnamate com-25 ponent connected to the vinyl backbone through: :
a) ~ component which provides stiffness and rod-like character to the cinnsmate component; and b) a spacer group having the backbone of from 7 to 14 atoms.
The spacer group is ~n alkylene group that includes up to four groups selected from ethers ~-0-t.
1 l 1 ~ 1 l . . :, esters t C-O-~. carbonates ~-OCO-~ and amides t C-NH t .
Exsmples of the latter groups include t-CH2CH20 ~ CH2CH2 :
o :
11 ::
wherein x is 1 to 4, -CH2CH2CH2CH2O-C-CH2CH2-, .:: .;
'. .
,. .. .
." -.
13283~0 O
-CH2-CH2-NHC-CH2CH2-~ -CH2CH2CH2-C-NHCH2CH2-~ etc.
The photocro~slinkable liquid crystalllne 5 polymers of the present invention achieve a 40 percent quantum yield of dimerization re~ulting in as much as an 9x increase in photographic speed of the polymers of the present invention compared to the poly(vinyl alcohol-co-vinyl-cinnamate) polymers 10 of the prior art of similar molecular weight. In addition, higher molecular weight liquid crystalline polymers o~ the present invention achieve an 83x increase in photographic speed compared to a poly-(vinyl alcohol-co-vinyl-cinnamate) control. Liquid 15 crystalline polymers of the invention generally have ~
an absolute molecular weight of 50,000 to 3,000,000. ~;
Applicants have theorized that this dramatic increase in quantum yield of dimerization and resulting increase in photographic speed results :
20 from the more ordered character of liquid cry~tal-line poly~ers compared to that of amorphous poly-mers. In the more ordered state of liquid crystal-; line polymers, the probability of the double bonds of the cinnamate components of the polymers being .
25 parallel to each other is significantly increasedover the likelihood of such double bonds being parallel in an amorphous polymer.
In an especially useful embodiment of the invention, the photocro~sllnkable liquid crystalline 30 polymer~ of this invention have the structure : -: : . ;, ., --4-- .
- R R3 ~ :
l I ,., (CH2-cl~lOO-x (CH2-C3x C=O C=O
R4 o ~ .
( IH2)n (CH2)m O O . , :::
C=O
ll i~ /ll I . .
O I
C=O . ~ .~
C=O I ~ -, CH=CH--~ ~._R2 ; ~:
il ~
.~ CH3 CH=NC-H -::.
~ 20 .~ ~.
wherein ~.
n represents an lnteger of from 3 to 10; ~. ........ ~:
m represent~ an integer of from 2 to 6;
x ha~:a value of O to 35 mole percent; .~.
R and R , each independently represents hydro- .;
gen or methyl; .. ;
R} represent~ phenylene, blphenylylene, ter- `~
: phenylylene, l,l'-binaphthyl-4,4'-ylene, phenylene- -oxycarbonylphenylene,:azodiphenylene, azodiphenyl- .,.
ene-N-oxide, naphthylene, ~tilbene-4,4'-diyl or ` ~;
a-aza~tilbene-4:,4l-diyl; :
: ; 35 R2 repre~enta alXyl 3uch as methyl, ethyl, ~.
propyl, butyl, 2-ethylhexyl end octyl, or alkoxy uch a~ methoxy,:ethoxy, propoxy, butoxy and octyloxy; and .. :;:
.., .
~ 1328330 R repre~ents -O- or -NH-.
The groups included in R , are among -groups known in the chemical literature to be stiff ~ -and rod-like.
In the above structure the spacer group is o O
-C-R4-tCH2 ~ C-. The group providing stiffness and O
10 rod-like character to the cinnamate group ls -R -O-C-.
DETAILS OF THE INVENTON
It is essential to the formation of liquld crystalline polymers of the invention that the spacer group snd the group which provides stiffness 15 and rod like character to the cinnamate component be present.
The spacer group is necessary to decouple the motion of the polymer backbone from the motion ~ -of the cinnamate-containing slde chains. Our ;; -~;
20 experimental work has shown that the spacer group should comprise a backbone of from 7 to 14 atoms.
It is also important to achieve the liquid m crystalline character of the polymers to provide a component attached to the cinnamate component which 25 provides the cinnamate component with stiffness and ~;
rod-like character. Our experiment-Q show that groups such as those mentioned as representative of R in structure I satisfies this need. However, it would be clear to those skilled in the art that 30 any group which provide~ the ~ufficient stiffness and rod-like character will work in achieving the liquid crystalline nature of the present polymers. ~-The concept of this invention applies to polymer~ eomprlsing any kind of light-sensitive 35 groups including photoconductive groups, photocross-linking groups, photopolymerizable group~, acid-photogenerating group~, etc.
~-~ . .
` - 13~83~0 The present invention also provides a method for making a photocrosslinkable liquid crystalline polymer comprising the steps of: ~ ;
preparing an acrylste compound having the . :
structure ', ' '~
R 0 :
CH2=C--C--R4--(CH2)n~H; ' ~ "' preparing a llght-sensitive compound having the structure :
.
. .. . ...
O O ' .:
HOC-Rl-0-C-CH=CH-~ R2 or its acid chloride;
-- :
:, - .
reacting the scrylate compound and the light-sensitive compound together to form a monomer having the structure .
R O O O . :: .
CH2=C-C-R4 t CH2 ~ C-Rl-0-C-CH=CH--~ ~--R2; and , .
polymerizing the monomer to form the light-sensitive acrylate liquid cry~talline polymeri ~:~ wherein .: .
R, R , R ~nd R are as previously deflned hereln. .
Polymer~ of th1~ invention can be made from their corresponding methscrylste or acrylste - :
monomers by 301ubilizstion in dichloroethane to a psrticular total solid~ concentrstion of 10-20%.
Polymeriz~tion i~ then initi~ted with 1~ 2,2'-35 szobi~(2-methylpropionitrile) (AIBN) by weight, ..
:~ unless otherwise indicated. The solutions were ~.:
, :. .
132~3~0 placed in polymerization vials, sealed with inert caps and purged with N2 for 20 minutes via ~yringe needles while cooling to eliminate evaporation. The fla~ks were then immer~ed in constant tempersture 5 baths at temperature~ of abou~ 50 to 90C for 15 hours. The resulting viscous solutions were diluted with dichloroethane and precipitated by adding the diluted solutions dropwise into ethyl ether with -vigorous stirring. Sollds were collected by vacuum 10 filtration and dried at room temperature under oil pump vacuum.
The following preparative example illustr-ates the method in making polymer 1 of Table I, infra. The examples al~o illustrate standard ~-~
15 techniques for preparing the monomers from which the ;
polymers are ultlmately made.
The group which provides stiffening and rod-like characteristics are added to the cinnamoyl component by reacting a compound, such as p-hydroxy 20 benzoic acid, 4'-hydoxy-1-biphenylcarboxylic flcid, 6-hydroxynaphthoic acid and 4-hydroxy-4'-stilbene-carboxylic acid with the cinnamoyl containing starting materisls in the presence of base.
The spacer group is added to the group 25 providing the stiffening and rod-like characteris-tic~ by reacting, as the ~pacer group, an acrylate or methacrylate compound, containing from 7 to 14 atoms. The acrylate or methacrylate compound includes the alkylene group ~hat includes the 30 ether~, carbonates, smides, etc., as defined herein-before, with the cinnamoyl heving attached thereto the group providing stiffening and rod-like character. This latter step i~ carried out by cont~cting the cinnamoyl containing compound with the acrylate or methacrylate compound in the presence of dicyclohexylcarbodiimide and 4-pyrroli-dinopyridine. -~ . .
,. ~.
'~'1' ' ' - . -Example 1 Preparation of PolY16-[4-(4-MethoxY- ~
cinnamoyloxY)benzoYloxylhexyl " ,, Methacrylate~
SteP 1 PreParation of 6-HYdroxYhexYl Methacry~ate Methacrylic acid (43.0 g = 0.5 mole) was -dissolved in 50 mL methanol. Tetrabutylammonium hydroxide (~5~ in methanol, 519 8m = 0.5 mole) was added to the latter solution. The solution was ~ -stirred for 30 minutes, and then freed of solvent on a rotary evaporator. The residue was dissolved in 100 mL of N,N-dimethylformamide (DMF) and a solution `
of 6-chloro-1-hexanol (68.3 gm + 0.5 mole) in 200 mL
DMF was added. This W8S stirred at 50C for 4 hours, the heat was discontinued, and the solution was stirred at room temperature overnight. An equal volume of H2O was combined and the solution W8S :
extracted with three portions of ethyl acetate. The combined ethyl acetate layers were back-extracted with three portions of H2O, dried over MgSO4, 20 and the mixture evaporated to an amber oil. H ;
NMR (CDC13): ~ (ppm) 4.1 (2H, t). Elemental : :
AnalysiS: CloH18O3~ mol- wt. 186- Calcd-: ;`
C, 61.5; H, 9.7; O, 25.8. Found: C, 61.7; H, 9.7.
SteP 2 PreParation of 4-MethoxYcin_amoYl Chloride p-Methoxyclnnamic acid (52.7 g - 0.~5 mole) -was slurried under N2 in 500 mL of sieve-drled dichloroethane. Oxalyl chloride (146.0 gm =
1.15 moles) was added in one portlon followed by three drops of DMF. Complete solution was achieved in 30 minutes. The solution was stirred an additional 2 hours, and then the dichloroethane containing excess oxalyl chloride was removed on a ; `
50C rot~ry evaporator. Fresh dichloroethane was twice added to the residue and removed on the rotary evaporator. The amber oil was used without purifi-~ caton. Yield 90.4 gm. ~ -,~ :~ . '. .. .
'...................................................................... . .
:. ..
1 328~30 SteP 3 PreParation of 4-(4-MethoxYcinnamoyloxy) Benzoic Acid This step lllu~trates the addition of an aryl group to the compound of Step 2 to incre~se the stiffness and rod-like characteristics of the alkyl or alkoxy substituted cinnamoyl group. The compound of Step 2 (1.0 gm = 5.1 mmole) w~s slurried under ;~
N2 in 10 mL dry pyridine. N,N-diisopropylethyl-amine (0.7 gm = 5.6 mmole) was added, followed by a spatula tip of 4-dimethylaminopyridine. A solution of p-hydroxybenzoic acid (0.7 gm, 5.1 mmole) in 7 mL -~
pyridine was added dropwise to the above slurry. An amber-orange solution soon developed. The solution was ~tirred for 60 minutes after addition was complete, and it was dropped slowly into 200 mL
ice/H2O containing 25 mL concentrated HCl. The resulting precipitste was collected by suction filtration, slurried twice with H2O on the funnel, and dried in a 40C vacuum oven. The white solid was recrystallized from boiling acetone. White needles, K280 l.c. Yield 0.6 gm. Elemental AnalysiS: C17H1405, mol- wt. 298-3- Calcd C, 68.5, H, 4.7, O, 26.8. Found: C, 68.5, H, 4.7.
~ b NMR ~DMSO-d ~: ~ (ppm) 6.7 (1 H, d), 8.0 ;1~ 25 (lH, d).
SteP 4 PreParation of 6-r4-(4-Methox~cinnamoYl-oxY~benzQyloxvlhexyl Methacr,Ylate .'~.-This step involved adding a polymerizable group and the remainder of the spacer group to the 30 compound of Step 3. The compound of Step 3 (25.5 g 5 85 mmole) was qlurrled in 800 mL dichloromethane.
The compound of Step 1 (15.8 g = 85 mmole) was added -in one portion, followed by dicyclohexylcarbodiimide 17.5 g = 85 mmole) and 4-pyrrolidinopyridine (1.3 g = 8.5 mmole). The mixture was stirred a~ room temperature for 4 hours, and then vacuum filtered.
:
',~
~ ~ .
1 3 2 8 ~ 3 ~
-10- , ~ ,, The filtrate wa~ washed with 5% aqueous acetic acid, H20, 3 portions 5~ aqueous Na2C03, H20, end then dried over MgS04 and freed of solvent on a rotary evaporator. The resulting solid was crystal-lized from low-boiling ligroin via a Soxhlet extractor. Fluffy white crystals, m.p. 65-67C.
Yield 31.8 g. Elemental Analysi~: C27H3007, mol. wt. 466.5. Anal. Calcd: C, 69.5; H, 6.5, 0, 24Ø Found: C, 69.5; H, 6.5; H NMR(CDC13):
~ (ppm) 4.4 (4 H, m).
SteP 5 PreParation of PolY{6-[4-(4- ``
MethoxYcinnamoYloxy~benzoYllhex~l MethacrYlate (PolYmer 1. Table I) This polymer was prepared from the monomer 15 of Step 4 by dissolving in ethyl ether and initiat- ~ ;
ing polymerization with 0.5 to 1.0% by welght of 2,2'-azobis(2-methylpropionitrile). The solutions ; :
were placed in polymerization vials, septa sealed and purged with N2 for 20 minutes vi~ ~yringe ;
2~ needles while cooling to eliminate evaporation. The flasks were then immersed in constant temperature bath3 at the prescribed temperatures for 15 hours.
The viscous solutions were dlluted with their respective solvents and precipitated by adding dropwise into the ethyl ether solvents with vigorous stirring. Sollds were collected by vacuum filtra- -tlon and dried at room temperature undsr oil pump vacuum. ;
Repre~entatlve polymers of thls lnvention are presented in Table I. The structure of all ; polymers were confirmed by elemental analysis and UV
spectroscopy. Absolute molecular weights were determined by known light scattering techniques.
iquid crystalllnlty of the polymer~ was confirmed by examlnatlon of polymer melts under a hot stage polarlzing mlcroscope. Under X polarlzers ~ typical nematic, cholesteric or smectic llquid ;~ crystalline textures were observed.
132~33~ ` `
`:
TABLE I
Polymer No. Absolute ~.
No. Structure I.V. Molecul~r Wei~ht : .
lA CIH3 n. 31 213~000 ~CH2 1~
C=O
, ,, ( C~ H2 ) 6 , , ~, 1=o , ~ ;' ,' i~
~ -CH=CH--f ~--OCH
lB CH 0.46 402,000 :~
~CH2~t `: ` C=O ` ' ;.. `~
1 ~
( CH2 ) 6 - .:
C;O
b ~ 35: ,C-CH=CH-f ~--OCH3 ~ ~ ' .,. ' .
TABLE I cont'd.
Polymer No. Absolute .
No. StructureI.V. Molecular Wei~ht :
~ . .
lC CH3 0.79 821,000 . .-~CH2--C~ ~,.
C=O
1 ,,"
(CH2)6 O -' . `, C=O , .
~1~
; i~ ,i1 , .
t ~ ~ o ~ .
~C-CH-CH~ --OCH3 lD ~ CH3 0.84 1,170,000 25 ~ O
~-~
~ ~C-CHsCH-~ OCH
132833~ :
TABLE I cont ' d .
Polymer No. Absolute No. Structure I V.Molecul~r Wei~ht lE CH3 1. 611, 760, 000 ~CH2--Ct ::
C=O
' "
( CH2 ) 6 . : ~
O
C=O ~, .
, . . .
1S ~',Q
~fC--CH=CH~ --OCH
~`
., ~ ~;
", ,~
" ': " ~ :~:
~3283'~0 . . ..
TABLE I cont ' d .
Polymer No.
No. Struture I.V.
C,H3 1 3 2 ~CH2--C)97 - (CH2--`C~ 0.35 ;
C=O C=O ..
1 1 .': ''., (C~H2)6 (CH2)2 . ,,:
O O ..~
c=o ,fl~
;~ 20 O=C-CH=CH~ --OCH3 g/; I
CH=N--C--H
!~ ,q l .,~
~ 35 ..~
1~28330 :~
TABLE I cont'd.
: ' ' Polymer No.
No.Structure I.V.
S ': ":
C~H3 ;.
3t CH2-C t O.21 -~
: ' . .
NH
.. .
( CH2 ) 5 ' ` . . ~ .
C50 .. ;.: ~
O ".'',-'"'.''' I~
` , ......
~: o O-C-CH=CH~ -OCH3 ~ ;
",,~
~ .
~.. ` i3283~
-16- ;
PhotograPhic Evaluation The polymer of the Example 1, Step 5 was made to Reveral different molecular weight~ for photographic Rpeed evalu~tion. These polymers are indicated in Table I as polymer~ lA through lE.
A poly(vinyl alcohol-co-vinyl benzoate-co- -~
vinyl 4-methoxycinnamate) copolymer (mole ratio 10/55/35) was prepared a_ a fir_t control (Control 1) (PVA control). Thi~ polymer is frequently used :
in photoresist applications. It has no spacer groups or groups to Rtiffen the cinnamoyl group. It has the structure: --~CH2-CH t o 35-tCH2 CIH t 0.10 -tCH2-CH t 0 55 OH o C=O C=O ~ ~.
CH=CH~ --OCH3 1l ~ ~
The above control polymer was prepared by the following procedure:
p-Methoxycinnamic acid (14.2 gm, 7.95 x 25 10 m) was treated with a 20 fold excess of oxalyl ~ ;
chlorlde. A drop of DMF wa~ added. After the evolution of HCl gas had ~ubsided, the solution was heated to reflux for l hour. The oxfllyl chloride was evaporsted off and an oil was i_olated. Thls acid chloride of p-m;thoxycinnamic acid weighed 15.63 gm (2.27 x 10 M).
Poly(vinyl alcohol) (PVA) (10 gm, 2.27 x 10 lM) (100~ hydrolyzed - abR. mw = 75,000) was -~
put in 100 ml of dry pyridine and stirred at 70C
35 overnight. 19.33 g of benzoyl chloride (0.137 m 10%
exce_s) wa-R sdded and the reaction was allowed to ~ ",:.
132~3~
stir for 4 hrs. Next, the p-methoxycinnsmoyl chloride was added snd the reaction was stirred overnight. The cooled solution was then precipit-ated into methanol. The isolated polymer was put in 1,2-dichloromethane and reprecipitated into methanol. This was repeated twice. Yield 24.4 g I.V.-1.15.
The molecul~r weight of this control polymer could not be determined by Gel Permeation 10 Chromatography or light scattering. However, it is known that the degree of polymerization of the backbone is 1700 which makes the absolute molecular weight approximately 268,000.
Goating formulations of the polymers to be -~
evaluated and a coumarin sensitizer were prepared with the following composition and cast as films on aluminum supports. -Two dlfferent molecular weight version~ of polyt2-(4-methoxycinnamoyloxy)ethyl methacrylate-20 co-methyl methacrylate] (mole ratio 35/65) were prepared a~ Controls A and B to show that a short spacer group hsving less than four carbon atoms ~--between the polymer backbone and the methoxy cinna-mate group was not sufficient to signlficantly ~;
; 25 improve photographic speed or result in liquid ;
I crystallinity of these polymers. This polymer has -~
the structure~
30-~CH2-Ct- o 35-~cH2-ct- 0.65 C=O COOCH3 ~ ~ O ~ :
CH2cH2occH=cH~ -OCH3 l : .~.;. :' ~ , ~ - . ' .~S
13~83~0 All polymers evaluated were dissolved ln cyclohexanone at 3 percent by weight. The light-sensitive cinnamoyl components of each polymer were ad~usted to 2.1 molar. The coumarin ~ensitizer was KC-74*. Its concentration was adJusted to 3 x molar in the solution.
.
* OPr ll OPr ,~,..
b Pr ~ \~ -/ ~ Pr The thus formed coating formulations were coated on aluminum supports. Each coating was the -~ame optical density. Each film was then exposed on an optical bench with a PEK 200 watt super high pressure mercury light source. The appropriste filters were used (~ > 405 nm) to insure that only the sensitizer absorbed the incident radia-tion. The films were irradiated through a photo-grsphic step tablet in which the denslty varies in increments of 0.15 per step. After irradiation, the films were developed by soaking in cyclohexanone for - ~
1 minute or until no further change was noted. ~ ;;
Table II shows the molecular weights snd ~; the relative photographic speed results of the "
amorPhous controls and various molecular weight versions of Polymer 1, Table I of the invention. '~
The difference in the photographic speed between the PVA control and Control B could be attributed to the difference in the backbone configurations and the effect the backbone hs~ on the orlentation-of ~he ~;~
cinnsmate component. Also, the -C2H4- spacer removes some of the orientational influence the r3~ ' 1328~0 :
--19-- , ."
polymeric backbone might exert on the cinnamate - -component. The latter effect most certainly would increase the photographlc speed of the polymer. The effect that the molecular weight played on the photographic speed of light-sensitlve polymers is best illustrated by comparing control polymers (A) and (B) in Table II.
It was necessary to handle films of Polymers lC, lE and lD under safe-light conditions to avoid premature fogging. Polymer lE has a molecular weight 6X that of the PVA cinnamate -control, but was 83X faster. The molecular weight difference certainly accounted for some of this increased speed but obviou~ly could not account for all of it. This data shows that the liquid crystalline polymers of this invention present the necessary ordered state to dramatically increase the photographic speed of photocrosslinkable polymers. ~-~
~ `~
''''.':,` ,, ".,''''`'"'"
..: .:; .
~,~. ,'' ~ : ' ,'', ~ 30 ~ ~
`' ~ '' .' ' ~ 35 : :~
~ ~ :-'.'':.-:
132~3~ ~
_~ O I O ~ ~
~ o ~ -~
I n O 3 ~ ~
I cn ~al CD O U~ I O O S ,, , 40 e ~ c ~ a~ ' e C ~ I I ^ ~ a a~
r~ l 3 ~ ~ o ~a i u~ ~0 o oO oO O O ~~
c i~ D ~ ~ e 3 ~ c ~- o -~ c 1 c0 E~ ~ ~ ',,',' :,' ô ¢ ~ 'C ~ ~ o c s .. , :,, c O 9~ ~ O c 2 C~ e c" ~ ~
P u ~ ~ C4 , , , ," ,, c~. ~ ~ ~ ra 13283~0 The invention has been described in detail with particular reference to preferred embodiments ~ ;
thereof, but it will be under~tood that variations ;-and modifications can be effected within the spirit ..
5 and scope of the invention.
".~
~, ' ,~', ' ,,,.,,.,; ,.",.
'" ''' '~ `'~
':`'' `, '~';
,, , ,~ .; . .
..
.',.,: ~' ' .'' '`-''':"''.^~' ~ 20 ;
~, ... . ~
: 25 .: ;
~ -
1 32833~
- --1-- ....
NOVEL PHOTOCROSSLINKABLE LIQUID CRYSTALLINE POLYMERS
Field of the Invention The present invention relates to novel photocrosslinkable liquid crystalline polymers and a method for their preparation and sn imaging element using the polymers.
_A KGROUND OF THE INVENTION
Photocrosslinkable polymers are known.
They have found many applications in lndustry. For example, photocrosslinkable polymers find many applicat~ons in the making of lithographic pl~tes and in photoresist applications. Many of the more useful photocrosslinkable polymers comprise, as a light-sensitive component, recurring cinnamate components. For example, polyvinyl cinnamate is formed by reacting polyvinyl alcohol wlth cinnamic acid. Such polymers are disclosed in U.S. Patent 3,817,876, U.S. Patent 4,230,817 and U.S. Patent 3,~33,746. :
In photolithographic and in photoresist applications, photocrosslinkable polymeric composi- ~ ;
tions are coated upon a su~table supporting surface such as a metal plate to form an imaging element.
Thereafter, the element is exposed to actinlc ~ 25 light. Exposure results in insolubilization of the -~ polymer in the exposed areas and solubilization of the polymer in the unexposed areas. The unexposed ;~
areas of the polymer coating can be removed by means of sultable solvent~ to leave a relief image.
The photosensitized crosslinking of amor-phous polymers such as those described in the bove-mentioned U.S. Patents generally ~how quantum yields of dimerizatlon of about 4 percent. Sensi-tizatlon of such polymers by ketocoumarins proceeds 35~ generally by triplet-triplet energy transfer. There '~
': :~
13~8330 are known to be several energy wsstage steps compet-ing with triplet-triplet energy transfer. In the case of amorphous cinnamate polymers, the triplet energy migrates step-wise from one cinnamate com-ponent to the next until it decays, or reaches an appropriate ~ite for promoting crosslinking. An appropriste site in this regard is a double bond of the cinnamate components aligned parallel to each other, and approximately 4 angstoms apart. The triplet energy visits an average of 100 to 200 sites before an appropriate site is found. Since the lifetime of the triplet excited state is only 10 nanoseconds, the decay to the ground state dominates ;:~
over excimer formation which results in crosslinking. ~-It would be extremely important and useful to design polymers which would make better use of -triplet-triplet energy transfer which occurs with ketocoumarin sensitizatlon.
SUMMARY OF THE INVENTION
The present invention provides a photo-crosslinkable liquid crystalline polymer comprising a vinyl backbone having from 60 to 100 mole percent of recurring pendant groups comprising an alkyl or alkoxy substltuted light-sensitive cinnamate com-25 ponent connected to the vinyl backbone through: :
a) ~ component which provides stiffness and rod-like character to the cinnsmate component; and b) a spacer group having the backbone of from 7 to 14 atoms.
The spacer group is ~n alkylene group that includes up to four groups selected from ethers ~-0-t.
1 l 1 ~ 1 l . . :, esters t C-O-~. carbonates ~-OCO-~ and amides t C-NH t .
Exsmples of the latter groups include t-CH2CH20 ~ CH2CH2 :
o :
11 ::
wherein x is 1 to 4, -CH2CH2CH2CH2O-C-CH2CH2-, .:: .;
'. .
,. .. .
." -.
13283~0 O
-CH2-CH2-NHC-CH2CH2-~ -CH2CH2CH2-C-NHCH2CH2-~ etc.
The photocro~slinkable liquid crystalllne 5 polymers of the present invention achieve a 40 percent quantum yield of dimerization re~ulting in as much as an 9x increase in photographic speed of the polymers of the present invention compared to the poly(vinyl alcohol-co-vinyl-cinnamate) polymers 10 of the prior art of similar molecular weight. In addition, higher molecular weight liquid crystalline polymers o~ the present invention achieve an 83x increase in photographic speed compared to a poly-(vinyl alcohol-co-vinyl-cinnamate) control. Liquid 15 crystalline polymers of the invention generally have ~
an absolute molecular weight of 50,000 to 3,000,000. ~;
Applicants have theorized that this dramatic increase in quantum yield of dimerization and resulting increase in photographic speed results :
20 from the more ordered character of liquid cry~tal-line poly~ers compared to that of amorphous poly-mers. In the more ordered state of liquid crystal-; line polymers, the probability of the double bonds of the cinnamate components of the polymers being .
25 parallel to each other is significantly increasedover the likelihood of such double bonds being parallel in an amorphous polymer.
In an especially useful embodiment of the invention, the photocro~sllnkable liquid crystalline 30 polymer~ of this invention have the structure : -: : . ;, ., --4-- .
- R R3 ~ :
l I ,., (CH2-cl~lOO-x (CH2-C3x C=O C=O
R4 o ~ .
( IH2)n (CH2)m O O . , :::
C=O
ll i~ /ll I . .
O I
C=O . ~ .~
C=O I ~ -, CH=CH--~ ~._R2 ; ~:
il ~
.~ CH3 CH=NC-H -::.
~ 20 .~ ~.
wherein ~.
n represents an lnteger of from 3 to 10; ~. ........ ~:
m represent~ an integer of from 2 to 6;
x ha~:a value of O to 35 mole percent; .~.
R and R , each independently represents hydro- .;
gen or methyl; .. ;
R} represent~ phenylene, blphenylylene, ter- `~
: phenylylene, l,l'-binaphthyl-4,4'-ylene, phenylene- -oxycarbonylphenylene,:azodiphenylene, azodiphenyl- .,.
ene-N-oxide, naphthylene, ~tilbene-4,4'-diyl or ` ~;
a-aza~tilbene-4:,4l-diyl; :
: ; 35 R2 repre~enta alXyl 3uch as methyl, ethyl, ~.
propyl, butyl, 2-ethylhexyl end octyl, or alkoxy uch a~ methoxy,:ethoxy, propoxy, butoxy and octyloxy; and .. :;:
.., .
~ 1328330 R repre~ents -O- or -NH-.
The groups included in R , are among -groups known in the chemical literature to be stiff ~ -and rod-like.
In the above structure the spacer group is o O
-C-R4-tCH2 ~ C-. The group providing stiffness and O
10 rod-like character to the cinnamate group ls -R -O-C-.
DETAILS OF THE INVENTON
It is essential to the formation of liquld crystalline polymers of the invention that the spacer group snd the group which provides stiffness 15 and rod like character to the cinnamate component be present.
The spacer group is necessary to decouple the motion of the polymer backbone from the motion ~ -of the cinnamate-containing slde chains. Our ;; -~;
20 experimental work has shown that the spacer group should comprise a backbone of from 7 to 14 atoms.
It is also important to achieve the liquid m crystalline character of the polymers to provide a component attached to the cinnamate component which 25 provides the cinnamate component with stiffness and ~;
rod-like character. Our experiment-Q show that groups such as those mentioned as representative of R in structure I satisfies this need. However, it would be clear to those skilled in the art that 30 any group which provide~ the ~ufficient stiffness and rod-like character will work in achieving the liquid crystalline nature of the present polymers. ~-The concept of this invention applies to polymer~ eomprlsing any kind of light-sensitive 35 groups including photoconductive groups, photocross-linking groups, photopolymerizable group~, acid-photogenerating group~, etc.
~-~ . .
` - 13~83~0 The present invention also provides a method for making a photocrosslinkable liquid crystalline polymer comprising the steps of: ~ ;
preparing an acrylste compound having the . :
structure ', ' '~
R 0 :
CH2=C--C--R4--(CH2)n~H; ' ~ "' preparing a llght-sensitive compound having the structure :
.
. .. . ...
O O ' .:
HOC-Rl-0-C-CH=CH-~ R2 or its acid chloride;
-- :
:, - .
reacting the scrylate compound and the light-sensitive compound together to form a monomer having the structure .
R O O O . :: .
CH2=C-C-R4 t CH2 ~ C-Rl-0-C-CH=CH--~ ~--R2; and , .
polymerizing the monomer to form the light-sensitive acrylate liquid cry~talline polymeri ~:~ wherein .: .
R, R , R ~nd R are as previously deflned hereln. .
Polymer~ of th1~ invention can be made from their corresponding methscrylste or acrylste - :
monomers by 301ubilizstion in dichloroethane to a psrticular total solid~ concentrstion of 10-20%.
Polymeriz~tion i~ then initi~ted with 1~ 2,2'-35 szobi~(2-methylpropionitrile) (AIBN) by weight, ..
:~ unless otherwise indicated. The solutions were ~.:
, :. .
132~3~0 placed in polymerization vials, sealed with inert caps and purged with N2 for 20 minutes via ~yringe needles while cooling to eliminate evaporation. The fla~ks were then immer~ed in constant tempersture 5 baths at temperature~ of abou~ 50 to 90C for 15 hours. The resulting viscous solutions were diluted with dichloroethane and precipitated by adding the diluted solutions dropwise into ethyl ether with -vigorous stirring. Sollds were collected by vacuum 10 filtration and dried at room temperature under oil pump vacuum.
The following preparative example illustr-ates the method in making polymer 1 of Table I, infra. The examples al~o illustrate standard ~-~
15 techniques for preparing the monomers from which the ;
polymers are ultlmately made.
The group which provides stiffening and rod-like characteristics are added to the cinnamoyl component by reacting a compound, such as p-hydroxy 20 benzoic acid, 4'-hydoxy-1-biphenylcarboxylic flcid, 6-hydroxynaphthoic acid and 4-hydroxy-4'-stilbene-carboxylic acid with the cinnamoyl containing starting materisls in the presence of base.
The spacer group is added to the group 25 providing the stiffening and rod-like characteris-tic~ by reacting, as the ~pacer group, an acrylate or methacrylate compound, containing from 7 to 14 atoms. The acrylate or methacrylate compound includes the alkylene group ~hat includes the 30 ether~, carbonates, smides, etc., as defined herein-before, with the cinnamoyl heving attached thereto the group providing stiffening and rod-like character. This latter step i~ carried out by cont~cting the cinnamoyl containing compound with the acrylate or methacrylate compound in the presence of dicyclohexylcarbodiimide and 4-pyrroli-dinopyridine. -~ . .
,. ~.
'~'1' ' ' - . -Example 1 Preparation of PolY16-[4-(4-MethoxY- ~
cinnamoyloxY)benzoYloxylhexyl " ,, Methacrylate~
SteP 1 PreParation of 6-HYdroxYhexYl Methacry~ate Methacrylic acid (43.0 g = 0.5 mole) was -dissolved in 50 mL methanol. Tetrabutylammonium hydroxide (~5~ in methanol, 519 8m = 0.5 mole) was added to the latter solution. The solution was ~ -stirred for 30 minutes, and then freed of solvent on a rotary evaporator. The residue was dissolved in 100 mL of N,N-dimethylformamide (DMF) and a solution `
of 6-chloro-1-hexanol (68.3 gm + 0.5 mole) in 200 mL
DMF was added. This W8S stirred at 50C for 4 hours, the heat was discontinued, and the solution was stirred at room temperature overnight. An equal volume of H2O was combined and the solution W8S :
extracted with three portions of ethyl acetate. The combined ethyl acetate layers were back-extracted with three portions of H2O, dried over MgSO4, 20 and the mixture evaporated to an amber oil. H ;
NMR (CDC13): ~ (ppm) 4.1 (2H, t). Elemental : :
AnalysiS: CloH18O3~ mol- wt. 186- Calcd-: ;`
C, 61.5; H, 9.7; O, 25.8. Found: C, 61.7; H, 9.7.
SteP 2 PreParation of 4-MethoxYcin_amoYl Chloride p-Methoxyclnnamic acid (52.7 g - 0.~5 mole) -was slurried under N2 in 500 mL of sieve-drled dichloroethane. Oxalyl chloride (146.0 gm =
1.15 moles) was added in one portlon followed by three drops of DMF. Complete solution was achieved in 30 minutes. The solution was stirred an additional 2 hours, and then the dichloroethane containing excess oxalyl chloride was removed on a ; `
50C rot~ry evaporator. Fresh dichloroethane was twice added to the residue and removed on the rotary evaporator. The amber oil was used without purifi-~ caton. Yield 90.4 gm. ~ -,~ :~ . '. .. .
'...................................................................... . .
:. ..
1 328~30 SteP 3 PreParation of 4-(4-MethoxYcinnamoyloxy) Benzoic Acid This step lllu~trates the addition of an aryl group to the compound of Step 2 to incre~se the stiffness and rod-like characteristics of the alkyl or alkoxy substituted cinnamoyl group. The compound of Step 2 (1.0 gm = 5.1 mmole) w~s slurried under ;~
N2 in 10 mL dry pyridine. N,N-diisopropylethyl-amine (0.7 gm = 5.6 mmole) was added, followed by a spatula tip of 4-dimethylaminopyridine. A solution of p-hydroxybenzoic acid (0.7 gm, 5.1 mmole) in 7 mL -~
pyridine was added dropwise to the above slurry. An amber-orange solution soon developed. The solution was ~tirred for 60 minutes after addition was complete, and it was dropped slowly into 200 mL
ice/H2O containing 25 mL concentrated HCl. The resulting precipitste was collected by suction filtration, slurried twice with H2O on the funnel, and dried in a 40C vacuum oven. The white solid was recrystallized from boiling acetone. White needles, K280 l.c. Yield 0.6 gm. Elemental AnalysiS: C17H1405, mol- wt. 298-3- Calcd C, 68.5, H, 4.7, O, 26.8. Found: C, 68.5, H, 4.7.
~ b NMR ~DMSO-d ~: ~ (ppm) 6.7 (1 H, d), 8.0 ;1~ 25 (lH, d).
SteP 4 PreParation of 6-r4-(4-Methox~cinnamoYl-oxY~benzQyloxvlhexyl Methacr,Ylate .'~.-This step involved adding a polymerizable group and the remainder of the spacer group to the 30 compound of Step 3. The compound of Step 3 (25.5 g 5 85 mmole) was qlurrled in 800 mL dichloromethane.
The compound of Step 1 (15.8 g = 85 mmole) was added -in one portion, followed by dicyclohexylcarbodiimide 17.5 g = 85 mmole) and 4-pyrrolidinopyridine (1.3 g = 8.5 mmole). The mixture was stirred a~ room temperature for 4 hours, and then vacuum filtered.
:
',~
~ ~ .
1 3 2 8 ~ 3 ~
-10- , ~ ,, The filtrate wa~ washed with 5% aqueous acetic acid, H20, 3 portions 5~ aqueous Na2C03, H20, end then dried over MgS04 and freed of solvent on a rotary evaporator. The resulting solid was crystal-lized from low-boiling ligroin via a Soxhlet extractor. Fluffy white crystals, m.p. 65-67C.
Yield 31.8 g. Elemental Analysi~: C27H3007, mol. wt. 466.5. Anal. Calcd: C, 69.5; H, 6.5, 0, 24Ø Found: C, 69.5; H, 6.5; H NMR(CDC13):
~ (ppm) 4.4 (4 H, m).
SteP 5 PreParation of PolY{6-[4-(4- ``
MethoxYcinnamoYloxy~benzoYllhex~l MethacrYlate (PolYmer 1. Table I) This polymer was prepared from the monomer 15 of Step 4 by dissolving in ethyl ether and initiat- ~ ;
ing polymerization with 0.5 to 1.0% by welght of 2,2'-azobis(2-methylpropionitrile). The solutions ; :
were placed in polymerization vials, septa sealed and purged with N2 for 20 minutes vi~ ~yringe ;
2~ needles while cooling to eliminate evaporation. The flasks were then immersed in constant temperature bath3 at the prescribed temperatures for 15 hours.
The viscous solutions were dlluted with their respective solvents and precipitated by adding dropwise into the ethyl ether solvents with vigorous stirring. Sollds were collected by vacuum filtra- -tlon and dried at room temperature undsr oil pump vacuum. ;
Repre~entatlve polymers of thls lnvention are presented in Table I. The structure of all ; polymers were confirmed by elemental analysis and UV
spectroscopy. Absolute molecular weights were determined by known light scattering techniques.
iquid crystalllnlty of the polymer~ was confirmed by examlnatlon of polymer melts under a hot stage polarlzing mlcroscope. Under X polarlzers ~ typical nematic, cholesteric or smectic llquid ;~ crystalline textures were observed.
132~33~ ` `
`:
TABLE I
Polymer No. Absolute ~.
No. Structure I.V. Molecul~r Wei~ht : .
lA CIH3 n. 31 213~000 ~CH2 1~
C=O
, ,, ( C~ H2 ) 6 , , ~, 1=o , ~ ;' ,' i~
~ -CH=CH--f ~--OCH
lB CH 0.46 402,000 :~
~CH2~t `: ` C=O ` ' ;.. `~
1 ~
( CH2 ) 6 - .:
C;O
b ~ 35: ,C-CH=CH-f ~--OCH3 ~ ~ ' .,. ' .
TABLE I cont'd.
Polymer No. Absolute .
No. StructureI.V. Molecular Wei~ht :
~ . .
lC CH3 0.79 821,000 . .-~CH2--C~ ~,.
C=O
1 ,,"
(CH2)6 O -' . `, C=O , .
~1~
; i~ ,i1 , .
t ~ ~ o ~ .
~C-CH-CH~ --OCH3 lD ~ CH3 0.84 1,170,000 25 ~ O
~-~
~ ~C-CHsCH-~ OCH
132833~ :
TABLE I cont ' d .
Polymer No. Absolute No. Structure I V.Molecul~r Wei~ht lE CH3 1. 611, 760, 000 ~CH2--Ct ::
C=O
' "
( CH2 ) 6 . : ~
O
C=O ~, .
, . . .
1S ~',Q
~fC--CH=CH~ --OCH
~`
., ~ ~;
", ,~
" ': " ~ :~:
~3283'~0 . . ..
TABLE I cont ' d .
Polymer No.
No. Struture I.V.
C,H3 1 3 2 ~CH2--C)97 - (CH2--`C~ 0.35 ;
C=O C=O ..
1 1 .': ''., (C~H2)6 (CH2)2 . ,,:
O O ..~
c=o ,fl~
;~ 20 O=C-CH=CH~ --OCH3 g/; I
CH=N--C--H
!~ ,q l .,~
~ 35 ..~
1~28330 :~
TABLE I cont'd.
: ' ' Polymer No.
No.Structure I.V.
S ': ":
C~H3 ;.
3t CH2-C t O.21 -~
: ' . .
NH
.. .
( CH2 ) 5 ' ` . . ~ .
C50 .. ;.: ~
O ".'',-'"'.''' I~
` , ......
~: o O-C-CH=CH~ -OCH3 ~ ;
",,~
~ .
~.. ` i3283~
-16- ;
PhotograPhic Evaluation The polymer of the Example 1, Step 5 was made to Reveral different molecular weight~ for photographic Rpeed evalu~tion. These polymers are indicated in Table I as polymer~ lA through lE.
A poly(vinyl alcohol-co-vinyl benzoate-co- -~
vinyl 4-methoxycinnamate) copolymer (mole ratio 10/55/35) was prepared a_ a fir_t control (Control 1) (PVA control). Thi~ polymer is frequently used :
in photoresist applications. It has no spacer groups or groups to Rtiffen the cinnamoyl group. It has the structure: --~CH2-CH t o 35-tCH2 CIH t 0.10 -tCH2-CH t 0 55 OH o C=O C=O ~ ~.
CH=CH~ --OCH3 1l ~ ~
The above control polymer was prepared by the following procedure:
p-Methoxycinnamic acid (14.2 gm, 7.95 x 25 10 m) was treated with a 20 fold excess of oxalyl ~ ;
chlorlde. A drop of DMF wa~ added. After the evolution of HCl gas had ~ubsided, the solution was heated to reflux for l hour. The oxfllyl chloride was evaporsted off and an oil was i_olated. Thls acid chloride of p-m;thoxycinnamic acid weighed 15.63 gm (2.27 x 10 M).
Poly(vinyl alcohol) (PVA) (10 gm, 2.27 x 10 lM) (100~ hydrolyzed - abR. mw = 75,000) was -~
put in 100 ml of dry pyridine and stirred at 70C
35 overnight. 19.33 g of benzoyl chloride (0.137 m 10%
exce_s) wa-R sdded and the reaction was allowed to ~ ",:.
132~3~
stir for 4 hrs. Next, the p-methoxycinnsmoyl chloride was added snd the reaction was stirred overnight. The cooled solution was then precipit-ated into methanol. The isolated polymer was put in 1,2-dichloromethane and reprecipitated into methanol. This was repeated twice. Yield 24.4 g I.V.-1.15.
The molecul~r weight of this control polymer could not be determined by Gel Permeation 10 Chromatography or light scattering. However, it is known that the degree of polymerization of the backbone is 1700 which makes the absolute molecular weight approximately 268,000.
Goating formulations of the polymers to be -~
evaluated and a coumarin sensitizer were prepared with the following composition and cast as films on aluminum supports. -Two dlfferent molecular weight version~ of polyt2-(4-methoxycinnamoyloxy)ethyl methacrylate-20 co-methyl methacrylate] (mole ratio 35/65) were prepared a~ Controls A and B to show that a short spacer group hsving less than four carbon atoms ~--between the polymer backbone and the methoxy cinna-mate group was not sufficient to signlficantly ~;
; 25 improve photographic speed or result in liquid ;
I crystallinity of these polymers. This polymer has -~
the structure~
30-~CH2-Ct- o 35-~cH2-ct- 0.65 C=O COOCH3 ~ ~ O ~ :
CH2cH2occH=cH~ -OCH3 l : .~.;. :' ~ , ~ - . ' .~S
13~83~0 All polymers evaluated were dissolved ln cyclohexanone at 3 percent by weight. The light-sensitive cinnamoyl components of each polymer were ad~usted to 2.1 molar. The coumarin ~ensitizer was KC-74*. Its concentration was adJusted to 3 x molar in the solution.
.
* OPr ll OPr ,~,..
b Pr ~ \~ -/ ~ Pr The thus formed coating formulations were coated on aluminum supports. Each coating was the -~ame optical density. Each film was then exposed on an optical bench with a PEK 200 watt super high pressure mercury light source. The appropriste filters were used (~ > 405 nm) to insure that only the sensitizer absorbed the incident radia-tion. The films were irradiated through a photo-grsphic step tablet in which the denslty varies in increments of 0.15 per step. After irradiation, the films were developed by soaking in cyclohexanone for - ~
1 minute or until no further change was noted. ~ ;;
Table II shows the molecular weights snd ~; the relative photographic speed results of the "
amorPhous controls and various molecular weight versions of Polymer 1, Table I of the invention. '~
The difference in the photographic speed between the PVA control and Control B could be attributed to the difference in the backbone configurations and the effect the backbone hs~ on the orlentation-of ~he ~;~
cinnsmate component. Also, the -C2H4- spacer removes some of the orientational influence the r3~ ' 1328~0 :
--19-- , ."
polymeric backbone might exert on the cinnamate - -component. The latter effect most certainly would increase the photographlc speed of the polymer. The effect that the molecular weight played on the photographic speed of light-sensitlve polymers is best illustrated by comparing control polymers (A) and (B) in Table II.
It was necessary to handle films of Polymers lC, lE and lD under safe-light conditions to avoid premature fogging. Polymer lE has a molecular weight 6X that of the PVA cinnamate -control, but was 83X faster. The molecular weight difference certainly accounted for some of this increased speed but obviou~ly could not account for all of it. This data shows that the liquid crystalline polymers of this invention present the necessary ordered state to dramatically increase the photographic speed of photocrosslinkable polymers. ~-~
~ `~
''''.':,` ,, ".,''''`'"'"
..: .:; .
~,~. ,'' ~ : ' ,'', ~ 30 ~ ~
`' ~ '' .' ' ~ 35 : :~
~ ~ :-'.'':.-:
132~3~ ~
_~ O I O ~ ~
~ o ~ -~
I n O 3 ~ ~
I cn ~al CD O U~ I O O S ,, , 40 e ~ c ~ a~ ' e C ~ I I ^ ~ a a~
r~ l 3 ~ ~ o ~a i u~ ~0 o oO oO O O ~~
c i~ D ~ ~ e 3 ~ c ~- o -~ c 1 c0 E~ ~ ~ ',,',' :,' ô ¢ ~ 'C ~ ~ o c s .. , :,, c O 9~ ~ O c 2 C~ e c" ~ ~
P u ~ ~ C4 , , , ," ,, c~. ~ ~ ~ ra 13283~0 The invention has been described in detail with particular reference to preferred embodiments ~ ;
thereof, but it will be under~tood that variations ;-and modifications can be effected within the spirit ..
5 and scope of the invention.
".~
~, ' ,~', ' ,,,.,,.,; ,.",.
'" ''' '~ `'~
':`'' `, '~';
,, , ,~ .; . .
..
.',.,: ~' ' .'' '`-''':"''.^~' ~ 20 ;
~, ... . ~
: 25 .: ;
~ -
Claims (8)
1. A photocrosslinkable liquid crystal-line polymer comprising a vinyl backbone having from 60 to 100 mole percent of recurring pendant groups comprising an alkyl or alkoxy light-sensitive cinnamate component connected via its ester group to the vinyl backbone through a) a component which provides stiffness and rod-like character to the cinnamate component and b) a spacer group having a backbone of from 7 to 14 atoms.
2. The polymer of claim 1 having the structure:
I
wherein n represents an integer of from 3 to 10;
m represents an integer of from 2 to 6;
x has a value of 0 to 35 mole percent;
R and R3 each independently represents hydrogen or methyl;
R1 represents phenylene, biphenylene, terphenylene, 1,1-binaphthyl-4,4'-ylene, phenyleneoxycarbonylphenylene, azodiphenylene-N-oxide, napthtylene, stilbene-4,4'-diyl or .alpha.-azastilbene-4-4'-diyl;
R2 represents alkyl or alkoxy; and R4 represents -O- or -NH-.
I
wherein n represents an integer of from 3 to 10;
m represents an integer of from 2 to 6;
x has a value of 0 to 35 mole percent;
R and R3 each independently represents hydrogen or methyl;
R1 represents phenylene, biphenylene, terphenylene, 1,1-binaphthyl-4,4'-ylene, phenyleneoxycarbonylphenylene, azodiphenylene-N-oxide, napthtylene, stilbene-4,4'-diyl or .alpha.-azastilbene-4-4'-diyl;
R2 represents alkyl or alkoxy; and R4 represents -O- or -NH-.
3. The polymer of claim 2 wherein R and R3 represents methyl x is 0 to 5 mole percent;
n is 5 to 6;
m is 2 to 6;
R1 represents phenylene; and R2 represents methyl, ethyl, propyl, butyl, 2-ethyl hexyl and octyl; or methoxy, ethoxy, propoxy, butoxy and octyloxy.
n is 5 to 6;
m is 2 to 6;
R1 represents phenylene; and R2 represents methyl, ethyl, propyl, butyl, 2-ethyl hexyl and octyl; or methoxy, ethoxy, propoxy, butoxy and octyloxy.
4. The polymer of claim 2 or 3 wherein x is zero.
5. The polymer of claim 2 selected from the group consisting of ; and .
6. A method of making a photocrosslink-able liquid crystalline polymer comprising the steps of:
preparing an acrylate compound having the structure ;
preparing a light-sensitive compound having the structure or its acid chloride;
reacting the acrylate compound and the light-sensitive compound together to form a monomer having the structure ; and polymerizing the monomer to form the light-sensitive acrylate liquid crystalline polymer;
wherein R represents hydrogen or methyl;
R1 represents phenylene, biphenylylene, ter-phenylylene, 1,1'-binaphthyl-4,4'-ylene, phenylene-oxycarbonylphenylene, azodiphenylene-N-oxide, naphthylene, stilbene-4,4'-diyl or .alpha.-azastil-bene-4,4'-diyl;
R2 represents an alkyl or alkoxy group;
R4 represents -O- or -NH-; and n represents an integer of from 3 to 10.
preparing an acrylate compound having the structure ;
preparing a light-sensitive compound having the structure or its acid chloride;
reacting the acrylate compound and the light-sensitive compound together to form a monomer having the structure ; and polymerizing the monomer to form the light-sensitive acrylate liquid crystalline polymer;
wherein R represents hydrogen or methyl;
R1 represents phenylene, biphenylylene, ter-phenylylene, 1,1'-binaphthyl-4,4'-ylene, phenylene-oxycarbonylphenylene, azodiphenylene-N-oxide, naphthylene, stilbene-4,4'-diyl or .alpha.-azastil-bene-4,4'-diyl;
R2 represents an alkyl or alkoxy group;
R4 represents -O- or -NH-; and n represents an integer of from 3 to 10.
7. An imaging element comprising a support bearing a layer containing a sensitizer and photocrosslinkable liquid crystalline polymer according to claim 1.
8. An imaging element comprising a support bearing a layer containing a sensitizer and photocrosslinkable liquid crystalline polymer according to claim 2.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US846,416 | 1986-03-31 | ||
| US06/846,416 US4696990A (en) | 1986-03-31 | 1986-03-31 | Novel photocrosslinkable liquid crystalline polymers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1328330C true CA1328330C (en) | 1994-04-05 |
Family
ID=25297869
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000518726A Expired - Fee Related CA1328330C (en) | 1986-03-31 | 1986-09-22 | Photocrosslinkable liquid crystalline polymers |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4696990A (en) |
| EP (1) | EP0240276B1 (en) |
| JP (1) | JPS62284350A (en) |
| CA (1) | CA1328330C (en) |
| DE (1) | DE3765153D1 (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4844835A (en) * | 1985-12-26 | 1989-07-04 | Idenitsu Kosan Co., Ltd. | Ferroelectric liquid crystal polymer |
| US5218045A (en) * | 1987-03-27 | 1993-06-08 | North Dakota State University | Coating binders comprising liquid crystalline enhanced polymers |
| US5244699A (en) * | 1987-03-27 | 1993-09-14 | North Dakota State University | Polymeric vehicle for coatings |
| JP2635613B2 (en) * | 1987-09-16 | 1997-07-30 | 株式会社東芝 | Method of forming resist pattern |
| US4925589A (en) * | 1987-12-29 | 1990-05-15 | Hoffmann-La Roche Inc. | Amide side-chain polymers |
| US5352312A (en) * | 1989-05-10 | 1994-10-04 | Thiokol Corporation | Method of insulating a rocket motor |
| US5078910A (en) * | 1989-06-20 | 1992-01-07 | Edison Polymer Innovation Corp. | Polimerization of liquid crystalline monomers |
| DE3924554A1 (en) * | 1989-07-25 | 1991-01-31 | Roehm Gmbh | ANISOTROPE LIQUID CRYSTALLINE POLYMER FILMS |
| FR2665452B1 (en) * | 1990-07-31 | 1992-10-09 | Thomson Csf | AMORPHOUS COPOLYMERS FOR PHOTOREFRACTIVE COMPOUNDS USED IN THE PROCESSING OF THE OPTICAL SIGNAL. |
| FR2668158B1 (en) * | 1990-10-22 | 1994-05-06 | Thomson Csf | CROSSLINKABLE POLYMER FOR NONLINEAR OPTICAL APPLICATIONS. |
| EP0492216B1 (en) * | 1990-12-21 | 1995-10-11 | F. Hoffmann-La Roche Ag | Non-linear optical polymeric layers |
| US5229474A (en) * | 1991-03-20 | 1993-07-20 | The Board Of Trustees Of The University Of Illinois | Synthesis of two-dimensional polymers by molecular recognition and chemical reaction among high molar mass monomers |
| US5539074A (en) * | 1993-02-17 | 1996-07-23 | Hoffmann-La Roche Inc. | Linear and cyclic polymers or oligomers having a photoreactive ethene group |
| US6160597A (en) | 1993-02-17 | 2000-12-12 | Rolic Ag | Optical component and method of manufacture |
| JP3384888B2 (en) * | 1994-09-14 | 2003-03-10 | 新日本石油株式会社 | Compensator for liquid crystal display element |
| KR19980048361A (en) * | 1996-12-17 | 1998-09-15 | 손욱 | Photo-alignment composition, alignment film formed from this, and liquid crystal display element provided with this alignment film |
| DE69820612T2 (en) | 1997-05-22 | 2004-10-14 | Rolic Ag | NEW POLYMERIZABLE LIQUID CRYSTAL LINKS |
| GB9812636D0 (en) * | 1998-06-11 | 1998-08-12 | Rolic Ag | Optical component orientation layer and layerable polymerisable mixture |
| US7105627B1 (en) | 2005-08-15 | 2006-09-12 | General Electric Company | Polyester stilbene composition |
| US20070037960A1 (en) * | 2005-08-15 | 2007-02-15 | General Electric Company | Copolyester stilbene embossed film and methods of making the same |
| US11084023B2 (en) * | 2019-03-22 | 2021-08-10 | Purdue Research Foundation | Phosphate-promoted nickel catalyst for high temperature oligomerization |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE755548A (en) * | 1969-08-29 | 1971-02-01 | Eastman Kodak Co | NEW PHOTOSENSITIVE POLYMER AND ITS APPLICATIONS IN PHOTOGRAPHY |
| JPS4929683B1 (en) * | 1970-09-16 | 1974-08-06 | ||
| JPS4928122B1 (en) * | 1970-12-26 | 1974-07-24 | ||
| JPS4938987A (en) * | 1972-08-18 | 1974-04-11 | ||
| JPS5637244B2 (en) * | 1973-02-13 | 1981-08-29 | ||
| US3933746A (en) * | 1973-06-14 | 1976-01-20 | Ball Corporation | Photopolymerizable polymers having anhydride-containing groups |
| DE2831909A1 (en) * | 1978-07-20 | 1980-02-07 | Basf Ag | LIQUID CRYSTALLINE POLYMER PHASE WITH CHOLESTERIC STRUCTURE, METHOD FOR THE PRODUCTION THEREOF AND THEIR USE |
| US4289842A (en) * | 1980-06-27 | 1981-09-15 | Eastman Kodak Company | Negative-working polymers useful as electron beam resists |
| DE3211400A1 (en) * | 1982-03-27 | 1983-09-29 | Basf Ag, 6700 Ludwigshafen | POLYMERS WITH MESOGENIC GROUPS AND DYE REMAINS IN THE SIDE CHAINS |
| US4434262A (en) * | 1982-09-01 | 1984-02-28 | Celanese Corporation | Melt processable blend of a low molecular weight liquid crystalline compound and a polyolefin or polyester |
| DE3500838A1 (en) * | 1985-01-12 | 1986-07-17 | Röhm GmbH, 6100 Darmstadt | POLYMERS WITH LIQUID CRYSTAL PROPERTIES AS INFORMATION CARRIERS |
-
1986
- 1986-03-31 US US06/846,416 patent/US4696990A/en not_active Expired - Fee Related
- 1986-09-22 CA CA000518726A patent/CA1328330C/en not_active Expired - Fee Related
-
1987
- 1987-03-27 JP JP62071919A patent/JPS62284350A/en active Pending
- 1987-03-30 DE DE8787302715T patent/DE3765153D1/en not_active Expired - Fee Related
- 1987-03-30 EP EP87302715A patent/EP0240276B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0240276B1 (en) | 1990-09-26 |
| DE3765153D1 (en) | 1990-10-31 |
| EP0240276A3 (en) | 1987-12-09 |
| US4696990A (en) | 1987-09-29 |
| JPS62284350A (en) | 1987-12-10 |
| EP0240276A2 (en) | 1987-10-07 |
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| MKLA | Lapsed |