Negative birefringent polyimide films

• US 5,480,964 A
• Filed: 04/21/1994
• Issued: 01/02/1996
• Est. Priority Date: 04/21/1993
• Status: Expired due to Term

• Current Assignee: University of Akron
• Original Assignee: University of Akron
• Inventors: Cheng, Stephen Z. D., Harris, Frank W.
• Primary Examiner(s): HAMPTON HIGHTOWER, PATRICIA
• Application Number:
  US08/230,729
• Time in Patent Office: 621 Days
• Field of Search: 528/353, 528/125, 528/128, 528/172, 528/173, 528/174, 528/176, 528/183, 528/188, 528/220, 528/229, 528/350, 528/351, 428/473.5
• US Class Current: 528/353
• CPC Class Codes: C08G 69/26 derived from polyamines and polycarboxylic acids
• CPC Class Codes: C08G 69/265 from at least two different diamines or at least two different dicarboxylic acids
• CPC Class Codes: C08G 69/32 from aromatic diamines and aromatic dicarboxylic acids with both amino and carboxylic groups aromatically bound
• CPC Class Codes: C08G 69/44 Polyester-amides
• CPC Class Codes: C08G 73/10 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C08G 73/1039 comprising halogen-containing substituents
• CPC Class Codes: C08G 73/106 containing silicon
• CPC Class Codes: C08G 73/1064 containing sulfur
• CPC Class Codes: C08G 73/1067 Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound
• CPC Class Codes: C08G 73/1071 Wholly aromatic polyimides containing oxygen in the form of ether bonds in the main chain
• CPC Class Codes: C08G 73/14 Polyamide-imides
• CPC Class Codes: C08G 73/16 Polyester-imides
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: G02F 2413/02 Number of plates being 2
• CPC Class Codes: G02F 2413/07 All plates on one side of the LC cell
• CPC Class Codes: Y10T 428/31721 Of polyimide

Abstract

A negative birefringent film, useful in liquid crystal displays, and a method for controlling the negative birefringence of a polyimide film is disclosed which allows the matching of an application to a targeted amount of birefringence by controlling the degree of in-plane orientation of the polyimide by the selection of functional groups within both the diamine and dianhydride segments of the polyimide which affect the polyimide backbone chain rigidity, linearity, and symmetry. The higher the rigidity, linearity and symmetry of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.

Claims

1. A homopolymer polyimide film for use in negative birefringence layers in liquid crystal displays, the film having a negative birefringence of 0.001 to 0.2, the film having been prepared from solutions of soluble polyimides having an aromatic dianhydride of general formula (II):

##STR141## and a polyaromatic diamine of formula (III) ##STR142## where F and G are selected independently from the group consisting of a covalent bond, a CH₂ group, a C(CH₃)₂ group, a C(CX₃)₂ group where X is a halogen, a CO group, an O atom, a S atom, a SO₂ group, a Si(R)₂ group wherein R is a substituent selected independently from the group consisting of H, phenyl, halogenated phenyl, alkyl and halogenated alkyl from 1 to 20 carbons, and a N(R) group wherein R is as defined previously;

A is selected from the group consisting of hydrogen, halogen, alkyl, halogenated alkyl, nitro, cyano, thioalkyl, alkoxy, halogenated alkoxy, aryl and halogenated aryl, aliphatic and aromatic esters and combinations thereof of from 1 to 20 carbons;

B is selected from the group consisting of halogens, C_1-3 alkyls, C_1-3 halogenated alkyls, phenyl or substituted phenyl wherein the substituents on the phenyl ting include halogens, C_1-3 alkyls, C_1-3 halogenated alkyls and combinations thereof;

z is an integer from 0 to 3;

n is an integer from 0 to 4; and

p and q are integers from 0 to 3 and 1 to 3 respectively, and when p and q are greater than 1, the linking group between benzyl or substituted benzyl groups is F; and

wherein the negative birefringence of the film is determined by controlling the degree of in-plane orientation of the polyimide by the selection of G, F, B and A, and the values of n, p, q and z which affects the polyimide backbone chain rigidity and linearity, the higher the rigidity and linearity of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.

2. The film of claim 1 wherein the aromatic dianhydride is selected from the group consisting of 3,3'"'"',4,4'"'"'-benzophenonetetracarboxylic acid dianhydride, 2,3,3'"'"',4'"'"'-benzophenonetetracarboxylic acid dianhydride, 2,2'"'"',3,3'"'"'-benzophenone tetracarboxylic acid dianhydride, 3,3'"'"',4,4'"'"'-biphenyltetracarboxylic acid dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(2,5,6-trifluoro-3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 4,4'"'"'-[4,4'"'"'-isopropylidene-di(p-phenyleneoxy)]bis(phthalic anhydride), N,N-(3,4-dicarboxyphenyl)-N-methylamine dianhydride, bis(3,4-dicarboxyphenyl)diethylsilane dianhydride, 2,3,6,7-naphthalene-tetracarboxylic acid dianhydride, 1,2,5,6-naphthalene-tetracarboxylic acid dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, thiophene-2,3,4,5-tetracarboxylic acid dianhydride, pyrazine-2,3,5,6-tetracarboxylic acid dianhydride, pyridine-2,3,5,6-tetracarboxylic acid dianhydride, 2,2'"'"'-dibromo-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-dichloro-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-diiodo-4,4'"'"', 5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-difluoro-4,4'"'"', 5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-bis(trifluoromethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, 2,2'"'"'-bis(trichloromethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, 2,2'"'"'-bis(tribromomethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, and 2,2'"'"'-bis(triiodomethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride.

3. The film of claim 1 wherein the diamine is selected from the group consisting of o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 1,4-diamino-2-methoxybenzene, 1,4-diamino-2-phenylbenzene, 1,3-diamino-4-chlorobenzene, 4,4'"'"'-diaminobiphenyl, 4,4'"'"'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 4,4'"'"'-diaminodiphenyl ether, 3,4'"'"'-diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'"'"'-bis(4-aminophenoxy)biphenyl, 4,4'"'"'-bis(3-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'"'"'-diaminodiphenyl thioether, 4,4'"'"'-diaminodiphenyl sulfone, 2,2'"'"'-diaminobenzophenone, 3,3'"'"'-diaminobenzophenone, 1,8-diaminonaphthalene, 1,5-diminonaphthalene, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 2,4-diamino-s-triazine, 2,2'"'"'-bis(trifluoromethyl)-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dibromo-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dicyano-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dichloro-6,6'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 3,3'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dicarboalkoxy-4,4'"'"'-diaminobiphenyl and 2,2'"'"'-dicarboalkoxy-6,6'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl.

4. The film of claim 1 wherein the aromatic dianhydride is formula (X) ##STR143## wherein Z is selected from the same group defined previously for B and m is an integer from 0 to 2.

5. A copolyimide film for use in negative birefringence layers in liquid crystal displays, the film having a negative birefringence of 0.001 to 0.2, the film having been prepared from solutions of soluble polyimides having at least one aromatic dianhydride of general formula (II) ##STR144## and at least one polyaromatic diamine of formula (III) ##STR145## where F and G are substituents selected independently from the group consisting of a covalent bond, a CH₂ group, a C(CH₃)₂ group, a C(CX₃)₂ group wherein X is a halogen, a CO group, an O atom, a S atom, a SO₂ group, a Si(R)₂ group wherein R is a substituent selected from the group consisting of H, phenyl, halogenated phenyl, alkyl and halogenated alkyl of from 1 to 20 carbons, and a N(R) group wherein R is as defined previously;

A is selected from the group consisting of hydrogen, halogen, alkyl, halogenated alkyl, nitro, cyano, thioalkyl, alkoxy, halogenated alkoxy, aryl and substituted aryl, aliphatic and aromatic esters and combinations thereof of from 1 to 20 carbons;

B is selected from the group consisting of halogens, C_1-3 alkyls, C_1-3 halogenated alkyls, phenyl and halogenated phenyl wherein the substituents on the phenyl ring include halogens, C_1-3 alkyls, C_1-3 halogenated alkyls and combinations thereof;

z is an integer from 0 to 3;

n is an integer from 0 to 4; and

p and q are integers from 0 to 3 and 1 to 3 respectively, and when p and q are greater than 1, the linking group between benzyl or substituted benzyl groups is F;

to form a copolyimide of formula (VII) ##STR146## wherein x varies from 100 to 0 while y varies correspondingly from 0 to 100; and

wherein the negative birefringence of the film is determined by the control of the degree of in-plane orientation of the copolyimide by the selection of G, F, B and A, and the values of n, p, q, x, y and z, which affects the polyimide backbone chain rigidity and linearity, the higher the rigidity and linearity of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.

6. The film of claim 5 wherein the aromatic dianhydride is selected from the group consisting of 3,3'"'"',4,4'"'"'-benzophenonetetracarboxylic acid dianhydride, 2,3,3'"'"',4'"'"'-benzophenonetetracarboxylic acid dianhydride, 2,2'"'"',3,3'"'"'-benzophenone tetracarboxylic acid dianhydride, 3,3'"'"',4,4'"'"'-biphenyltetracarboxylic acid dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(2,5,6-trifluoro-3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 4,4'"'"'-[4,4'"'"'-isopropylidene-di(p-phenyleneoxy)]bis(phthalic anhydride), N,N-(3,4-dicarboxyphenyl)-N-methylamine dianhydride, bis(3,4-dicarboxyphenyl)diethylsilane dianhydride, 2,3,6,7-naphthalene-tetracarboxylic acid dianhydride, 1,2,5,6-naphthalene-tetracarboxylic acid dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, thiophene-2,3,4,5-tetracarboxylic acid dianhydride, pyrazine-2,3,5,6-tetracarboxylic acid dianhydride, pyridine-2,3,5,6-tetracarboxylic acid dianhydride, 2,2'"'"'-dibromo-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-dichloro-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-diiodo-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-difluoro-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-bis(trifluoromethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, 2,2'"'"'-bis(trichloromethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, 2,2'"'"'-bis(tribromomethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, and 2,2'"'"'-bis(triiodomethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride.

7. The film of claim 5 wherein the diamine is selected from the group consisting of o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 1,4-diamino-2-methoxybenzene, 1,4-diamino-2-phenylbenzene, 1,3-diamino-4-chlorobenzene, 4,4'"'"'-diaminobiphenyl, 4,4'"'"'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 4,4'"'"'-diaminodiphenyl ether, 3,4'"'"'-diaminodiphenyl ether,1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'"'"'-bis(4-aminophenoxy)biphenyl, 4,4'"'"'-bis(3-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'"'"'-diaminodiphenyl thioether, 4,4'"'"'-diaminodiphenyl sulfone, 2,2'"'"'-diaminobenzophenone, 3,3'"'"'-diaminobenzophenone, 1,8-diaminonaphthalene, 1,5-diminonaphthalene, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 2,4-diamino-s-triazine, 2,2'"'"'-bis (trifluoromethyl)-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dibromo-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dicyano-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dichloro-6,6'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 3,3'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dicarboalkoxy-4,4'"'"'-diaminobiphenyl and 2,2'"'"'-dicarboalkoxy-6,6'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl.

8. The film of claim 5 wherein the aromatic dianhydride is formula (X) ##STR147## wherein Z is selected from the group previously defined for B and m is an integer from 0 to 2.

9. A copolyimide film for use in negative birefringence layers in liquid crystal displays, the film having a negative birefringence of 0.001 to 0.2, the film having been prepared from solutions of soluble polyimides having at least one first aromatic dianhydride of general formula (I) ##STR148## and at least one second aromatic dianhydride of formula (X) ##STR149## and at least one polyaromatic diamine of formula (III) ##STR150## where each R is a substituent selected independently from the group consisting of H, phenyl, halogenated phenyl, alkyl and halogenated alkyl from 1 to 20 carbons;

F and G are substituents selected independently from the group consisting of a covalent bond, a CH₂ group, a C(CH₃)₂ group, a C(CX₃)₂ group wherein X is a halogen, a CO group, an O atom, a S atom, a SO₂ group, a Si(R)₂ group wherein R is as defined previously and a N(R) group wherein R is as defined previously;

A is selected from the group consisting of hydrogen, halogen, alkyl, halogenated alkyl, nitro, cyano, thioalkyl, alkoxy, halogenated alkoxy, aryl and halogenated aryl, aliphatic and aromatic ester and combinations thereof of from 1 to 20 carbons;

B is selected from the group consisting of halogens, C_1-3 alkyls, C_1-3 halogenated alkyls, phenyl and halogenated phenyl wherein the substituents on the phenyl ring include halogens, C_1-3 alkyls, C_1-3 halogenated alkyls and combinations thereof;

z is an integer from 0 to 3;

n is an integer from 0 to 4; and

p and q are integers from 0 to 3 and 1 to 3 respectively, and when p and q are greater than 1, the linking group between benzyl or substituted benzyl groups is F;

to form a copolyimide of formula (VIII) ##STR151## wherein x varies from 100 to 0 while y varies correspondingly from 0 to 100; and

wherein the negative birefringence of the film is determined by the control of the degree of in-plane orientation of the polyimide by the selection of R, G, F, B and A, and the values of n, p, q, x, y and z, which affects the polyimide backbone chain rigidity and linearity, the higher the rigidity and linearity of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.

10. The film of claim 9 wherein the dianhydride is selected from the group consisting of pyromelletic dianhydride, 3,6-diphenylpyromellitic dianhydride, 3,6-bis(trifluoromethyl)pyromellitic dianhydride, 3,6-bis(methyl)pyromellitic dianhydride, 3,6-diidopyromellitic dianhydride, 3,6-dibromopyromellitic dianhydride and 3,6-dichloropyromellitic dianhydride, 3,3'"'"',4,4'"'"'-benzophenonetetracarboxylic acid dianhydride, 2,3,3'"'"',4'"'"'-benzophenonetetracarboxylic acid dianhydride, 2,2'"'"',3,3'"'"'-benzophenone tetracarboxylic acid dianhydride, 3,3'"'"',4,4'"'"'-biphenyltetracarboxylic acid dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(2,5,6-trifluoro-3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 4,4'"'"'-[4,4'"'"'-isopropylidene-di(p-phenyleneoxy)]bis(phthalic anhydride), N,N-(3,4-dicarboxyphenyl)-N-methylamine dianhydride, bis(3,4-dicarboxyphenyl)diethylsilane dianhydride, 2,3,6,7-naphthalene-tetracarboxylic acid dianhydride, 1,2,5,6-naphthalene-tetracarboxylic acid dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, thiophene-2,3,4,5-tetracarboxylic acid dianhydride, pyrazine-2,3,5,6-tetracarboxylic acid dianhydride, pyridine-2,3,5,6-tetracarboxylic acid dianhydride, 2,2'"'"'-dibromo-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-dichloro-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-diiodo-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-difluoro-4,4'"'"',5,5'"'"'-biphenyl tetracarboxylic dianhydride, 2,2'"'"'-bis(trifluoromethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, 2,2'"'"'-bis(trichloromethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, 2,2'"'"'-bis(tribromomethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride, and 2,2'"'"'-bis(triiodomethyl)-4,4'"'"'-5,5'"'"'-biphenyltetracarboxylic dianhydride.

11. The film of claim 9 wherein the diamine is selected from the group consisting of o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 1,4-diamino-2-methoxybenzene, 1,4-diamino-2-phenylbenzene, 1,3-diamino-4-chlorobenzene, 4,4'"'"'-diaminobiphenyl, 4,4'"'"'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 4,4'"'"'-diaminodiphenyl ether, 3,4'"'"'-diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'"'"'-bis(4-aminophenoxy)biphenyl, 4,4'"'"'-bis(3-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis [4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'"'"'-diaminodiphenyl thioether, 4,4'"'"'-diaminodiphenyl sulfone, 2,2'"'"'-diaminobenzophenone, 3,3'"'"'-diaminobenzophenone, 1,8-diaminonaphthalene, 1,5-diminonaphthalene, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 2,4-diamino-s-triazine, 2,2'"'"'-bis(trifluoromethyl)-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dibromo-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dicyano-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dichloro-6,6'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 3,3'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl, 2,2'"'"'-dicarboalkoxy-4,4'"'"'-diaminobiphenyl and 2,2'"'"'-dicarboalkoxy-6,6'"'"'-dimethyl-4,4'"'"'-diaminobiphenyl.

12. The film of claim 9 wherein the aromatic dianhydride is formula (X) ##STR152## wherein Z is selected from the same group defined previously for B and m is an integer from 0 to 2.