# US 2020/0399469 A1 · Aromatic Polyamide Films for Solvent Resistant Flexible Substrates

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- Number: US 2020/0399469 A1
- Document ID: US20200399469A1
- Status: Published application
- Kind: A1
- Application number: 17/007,337
- Filed: 2020-08-31
- Published: 2020-12-24
- Earliest claimed: 2011-07-05
- Assignees: Akron Polymer Systems, Inc.
- Applicants: Akron Polymer Systems, Inc.
- Inventors: Limin Sun; Dong Zhang; Frank W. Harris; Jiaokai Jing
- Web page: https://patentgrep.com/patent/US20200399469A1

## CPC

- C08L 77/10: Polyamides derived from aromatically bound amino and carboxyl groups of amino-carboxylic acids or of polyamines and polycarboxylic acids
- C08G 69/32: from aromatic diamines and aromatic dicarboxylic acids with both amino and carboxylic groups aromatically bound
- C08J 5/18: Manufacture of films or sheets
- C08J 2377/10: Polyamides derived from aromatically bound amino and carboxyl groups of amino carboxylic acids or of polyamines and polycarboxylic acids
- Y10T 428/2495: Thickness [relative or absolute]
- Y10T 428/269: including synthetic resin or polymer layer or component
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Films with optical transmittance of >80% between 400 and 750 nm and with coefficient of thermal expansion less than 20 ppm/° C. are prepared from aromatic polyamides that are soluble in polar organic solvents yet have glass transition temperatures>300° C. The films are cross-linked in the solid state by heating at elevated temperatures for short periods of time in the presence of multifunctional epoxides. Surprisingly, the optical and thermal properties of the films do not change significantly during the curing process. The temperature required for the crosslinking process to take place can be reduced by the presence of a few free, pendant carboxyl groups along the polyamide backbones. The films are useful as flexible substrates for electronic displays and photovoltaic devices.

## Claims

### Claim 1

A transparent aromatic polyamide films comprising:
(A) an aromatic polyamide that is capable of being thermally cross-linked, and has at least one repeat units of general formula (I):
wherein X represents the molar percentage of the repeat structure (I) and wherein the polyamide is soluble in polar organic solvents in the absence of inorganic salts and has a Tg higher than 300° C., and Ar1 is selected from the group consisting of:
wherein p is 4, q is 3, and wherein R1, R2, R3, R4, R5 are selected from the group comprising hydrogen; halogens; alkyl groups; substituted alkyl groups; cyano groups; thioalkyl groups, alkoxy groups; substituted alkoxy groups; aryl groups; substituted aryl groups; alkyl ester groups; substituted alkyl ester groups; and combinations thereof, wherein G1 is selected from a group comprising a covalent bond; a CH2 group; a C(CH3)2 group; a C(CF3)2 group; and a C(CM3)2 group, wherein M is selected from the group comprising a halogen; a CO group; an O atom; a S atom; a SO2 group; a Si(CH3)2 group; a 9,9′-bisphenylenefluorene group; a substituted 9,9′-bisphenylenefluorene group; and an OZO group, wherein Z is selected from the group comprising an aryl group; a substituted aryl group; a biphenyl group; a perfluorobiphenyl group; a 9,9′-bisphenylenefluorene group; and a substituted 9,9′-bisphenylenefluorene group, and
wherein at least one of the Ar1 groups in at least one of the repeat units (I) is selected from the group consisting of:
wherein Ar2 is selected from the group consisting of:
wherein p is 4, wherein R6, R7, and R8 are selected from the group comprising hydrogen; halogens; alkyl groups; substituted alkyl groups; cyano groups; thioalkyl groups, alkoxy groups; substituted alkoxy groups; aryl groups; substituted aryl groups; alkyl ester groups; substituted alkyl ester groups; and combinations thereof, wherein G2 is selected from the group comprising a covalent bond; a CH2 group; a C(CH3)2 group; a C(CF3)2 group; and a C(CM3)2 group, wherein M is selected from the group comprising a halogen; a CO group; an O atom; a S atom; a SO2 group; a Si(CH3)2 group; a 9,9′-bisphenylenefluorene group; a substituted 9,9′-bisphenylenefluorene group; and an OZO group, wherein Z is selected from the group comprising an aryl group; substituted aryl group; a biphenyl group, a perfluorobiphenyl group, a 9,9′-bisphenylenefluorene group, and a substituted 9,9′-bisphenylenefluorene group; and
wherein at least one of the Ar2 groups in at least one of the repeat units (I) is selected from the group consisting of:
and,
(B) a multifunctional epoxide selected from the group comprising the general structures (II), (III), and (IV):
wherein x>1 and R9 is selected from the group comprising
where the cyclic structure is selected from the group comprising
wherein n and n1>1 and R10 is an alkyl or aromatic group.

### Claim 2 (depends on 1)

The film of claim 1, wherein the multifunctional epoxide is between approximately 1 and approximately 10 wt % based on the weight of the polyamide.

### Claim 3 (depends on 1)

The film of claim 1, wherein the film thickness is greater than approximately 4 μm.

### Claim 4 (depends on 3)

The film of claim 3, wherein the film thickness is greater than approximately 4 μm and less than approximately 100 μm.

### Claim 5 (depends on 3)

The film of claim 3, wherein the film is approximately 10 μm thick and has a transmittance of >80% from 400 to 750 nm.

### Claim 6 (depends on 1)

The film of claim 1, wherein the film is heated under reduced pressure or under an inert atmosphere at a temperature that results in the film becoming solvent resistant.

### Claim 7 (depends on 6)

The film of claim 6, wherein heating is conducted at less than approximately 280° C. for at least approximately 1 minute.

### Claim 8 (depends on 6)

The film of claim 6, wherein heating is conducted between approximately 250° C. and approximately 280° C. for at least approximately 1 minute and less than approximately 30 minutes.

### Claim 9 (depends on 6)

The film of claim 6, wherein the film thickness is greater than approximately 4 μm.

### Claim 10 (depends on 9)

The film of claim 9, wherein the film thickness is greater than approximately 4 μm and less than approximately 100 μm.

### Claim 11 (depends on 9)

The film of claim 9, wherein a film approximately 10 μm thick has a transmittance of >80% from 400 to 750 nm.

### Claim 12 (depends on 11)

The film of claim 11, wherein the optical transmittance is >85% at 550 nm.

### Claim 13 (depends on 9)

The film of claim 9, wherein the film is adhered to a substrate.

### Claim 14 (depends on 13)

The film of claim 13, wherein the substrate is a glass film greater than approximately 50 μm thick.

### Claim 15 (depends on 6)

The film of claim 6, wherein the average coefficient of thermal expansion is less than approximately 20 ppm/° C. between 25° C. and 250° C.

### Claim 16 (depends on 15)

The film of claim 15, wherein the average coefficient of thermal expansion is less than approximately 10 ppm/° C. between 25° C. and 250° C.

### Claim 17

A polymer solution capable of being made into transparent films; wherein the polymer solution comprises: (A) an aromatic polyamide that is capable of being thermally cross-linked, and has at least one repeat units of general formula (I):
wherein X represents the molar percentage of the repeat structure (I) and wherein the polyamide is soluble in polar organic solvents in the absence of inorganic salts and has a Tg higher than 300° C., and Ar1 is selected from the group consisting of:
wherein p is 4, q is 3, and wherein R1, R2, R3, R4, R5 are selected from the group comprising hydrogen; halogens; alkyl groups; substituted alkyl groups; cyano groups; thioalkyl groups, alkoxy groups; substituted alkoxy groups; aryl groups; substituted aryl groups; alkyl ester groups; substituted alkyl ester groups; and combinations thereof, wherein G1 is selected from a group comprising a covalent bond; a CH2 group; a C(CH3)2 group; a C(CF3)2 group; and a C(CM3)2 group, wherein M is selected from the group comprising a halogen; a CO group; an O atom; a S atom; a SO2 group; a Si(CH3)2 group; a 9,9′-bisphenylenefluorene group; a substituted 9,9′-bisphenylenefluorene group; and an OZO group, wherein Z is selected from the group comprising an aryl group; a substituted aryl group; a biphenyl group; a perfluorobiphenyl group; a 9,9′-bisphenylenefluorene group; and a substituted 9,9′-bisphenylenefluorene group, and
wherein at least one of the Ar1 groups in at least one of the repeat units (I) is selected from the group consisting of:
wherein Ar2 is selected from the group consisting of:
wherein p is 4, wherein R6, R7, and R8 are selected from the group comprising hydrogen; halogens; alkyl groups; substituted alkyl groups; cyano groups; thioalkyl groups, alkoxy groups; substituted alkoxy groups; aryl groups; substituted aryl groups; alkyl ester groups; substituted alkyl ester groups; and combinations thereof, wherein G2 is selected from the group comprising a covalent bond; a CH2 group; a C(CH3)2 group; a C(CF3)2 group; and a C(CM3)2 group, wherein M is selected from the group comprising a halogen; a CO group; an O atom; a S atom; a SO2 group; a Si(CH3)2 group; a 9,9′-bisphenylenefluorene group; a substituted 9,9′-bisphenylenefluorene group; and an OZO group, wherein Z is selected from the group comprising an aryl group; substituted aryl group; a biphenyl group, a perfluorobiphenyl group, a 9,9′-bisphenylenefluorene group, and a substituted 9,9′-bisphenylenefluorene group; and
wherein at least one of the Ar2 groups in at least one of the repeat units (I) is selected from the group consisting of:
and,
(B) a multifunctional epoxide selected from the group comprising the general structures (II), (III), and (IV):
wherein x>1 and R9 is selected from the group comprising
where the cyclic structure is selected from the group comprising
wherein n and n1>1 and R10 is an alkyl or aromatic group.

### Claim 18 (depends on 17)

The polymer solution of claim 17, wherein the multifunctional epoxide is between approximately 1 and approximately 10 wt % based on the weight of the polyamide.

### Claim 19 (depends on 17)

The polymer solution of claim 17, wherein the polymer solution is solution cast into a film that has a film transparency of >80% between 400 nm and 750 nm.

### Claim 20 (depends on 17)

The polymer solution of claim 17, wherein the film thickness is greater than approximately 4 μm and less than approximately 100 μm.

### Claim 21 (depends on 17)

The polymer solution of claim 17, wherein the film is heated under reduced pressure or under an inert atmosphere at a temperature that results in the film becoming solvent resistant.

### Claim 22 (depends on 19)

The polymer solution of claim 19, wherein the solution cast film has an average coefficient of thermal expansion is less than approximately 20 ppm/° C. between 25° C. and 250° C.

### Claim 23

A polymer solution capable of being made into transparent films; wherein the polymer solution comprises:
(A) an aromatic copolyamide that is capable of being thermally cross-linked and having at least two repeat units of general formula (I) and (V):
wherein X represents the molar percentage of the repeat structure (I) and Y represents the molar percentage of the repeat structure (V) and wherein the copolyamide is soluble in polar organic solvents and can be solution cast into a clear film with a Tg higher than 300° C.; and Ar1 is selected from the group consisting of:
wherein p is 4, q is 3, and wherein R1, R2, R3, R4, R5 are selected from the group comprising hydrogen, halogen; alkyl groups; substituted alkyl groups; cyano groups; thioalkyl groups, alkoxy groups; substituted alkoxy groups; aryl groups; substituted aryl groups; alkyl ester groups; substituted alkyl ester groups; and combinations thereof, wherein G1 is selected from the group comprising a covalent bond; a CH2 group; a C(CH3)2 group; a C(CF3)2 group; and a C(CM3)2 group, wherein M is selected from the group comprising a halogen; a CO group; an O atom; a S atom; a SO2 group; a Si(CH3)2 group; a 9,9′-bisphenylenefluorene group; a substituted 9,9′-bisphenylenefluorene group; and an OZO group, wherein Z is selected from the group comprising a aryl group or substituted aryl group; a biphenyl group; a perfluorobiphenyl group; a 9,9′-bisphenylenefluorene group; and a substituted 9,9′-bisphenylenefluorene group,
and wherein at least one of the Ar1 groups in at least one of the repeat units of (I) or at least one of the repeat units of (V) is selected from the group consisting of:
wherein Ar2 is selected from the group consisting of:
wherein p is 4, wherein R6, R7, R8 are selected from the group comprising hydrogen, halogens; alkyl groups; substituted alkyl groups; cyano groups; thioalkyl groups, alkoxy groups; substituted alkoxy groups; aryl groups; substituted aryl groups; alkyl ester groups; substituted alkyl ester groups; and combinations thereof, wherein G2 is selected from the group comprising a covalent bond; a CH2 group; a C(CH3)2 group; a C(CF3)2 group; and a C(CM3)2 group, wherein M is selected from the group comprising a halogen; a CO group; an O atom; a S atom; a SO2 group; a Si(CH3)2 group; a 9,9′-bisphenylenefluorene group; a substituted 9,9′-bisphenylenefluorene group; and an OZO group, wherein Z is selected from the group comprising a aryl group or substituted aryl group; a perfluorobiphenyl group; a 9,9′-bisphenylenefluorene group; and a substituted 9,9′-bisphenylenefluorene group, and
wherein at least one of the Ar2 groups in at least one of the repeat units (I) is selected from the group consisting of:
and
wherein Ar3 is selected from the group comprising:
wherein t is 0 to 3, g is 0 to 4, and s is 0 to 4, wherein R9, R10, R11 are selected from the group comprising hydrogen, halogens; alkyl groups; substituted alkyl groups; cyano groups; thioalkyl groups, alkoxy groups; substituted alkoxy groups; aryl groups; substituted aryl groups; alkyl ester groups; substituted alkyl ester groups; and combinations thereof, wherein G3 is selected from the group comprising a covalent bond; a CH2 group; a C(CH3)2 group; a C(CF3)2 group; and a C(CM3)2 group, wherein M is selected from the group comprising a halogen; a CO group; an O atom; a S atom; a SO2 group; a Si(CH3)2 group; a 9,9′-bisphenylenefluorene group; a substituted 9,9′-bisphenylenefluorene group; and an OZO group, wherein Z is selected from the group comprising a aryl group; substituted aryl group; a biphenyl group; a perfluorobiphenyl group; a 9,9′-bisphenylenefluorene group; and a substituted 9,9′-bisphenylenefluorene group; and, wherein at least one Ar3 group in at least one of the repeat units (V) is selected from:
and
(B) a multifunctional epoxide selected from the group comprising the general structures (II), (III), and (IV):
wherein x>1 and R12 is selected from the group comprising
where the cyclic structure is selected from the group comprising
wherein n and n1>1 and R13 is an alkyl or aromatic group.

### Claim 24 (depends on 23)

The polymer solution of claim 23, wherein the copolyamide contains multiple repeat units with structures (I) and (V).

### Claim 25 (depends on 23)

The polymer solution of claim 23, wherein the copolyamide contains approximately 1 to approximately 10 mole % of the repeat unit containing at least one carboxyl group.

### Claim 26 (depends on 23)

The polymer solution of claim 23, wherein the film thickness is greater than approximately 4 μm and less than approximately 100 μm.

### Claim 27 (depends on 23)

The polymer solution of claim 23, wherein the film is approximately 10 μm thick and has a transmittance of >85% at 550 nm.

### Claim 28 (depends on 23)

The polymer solution of claim 23, wherein the film has an average coefficient of thermal expansion which is less than approximately 20 ppm/° C. between 25° C. and 250° C.