# US 11,306,126 B2 · Spider silk protein film, and method for producing same

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- Number: US 11,306,126 B2
- Document ID: US11306126B2
- Status: Granted
- Kind: B2
- Application number: 16/371,932
- Filed: 2019-04-01
- Published: 2019-10-03
- Granted: 2022-04-19
- Earliest claimed: 2012-12-26
- Assignees: Spiber Inc.
- Applicants: Spiber Inc.
- Inventors: Kaori Sekiyama; Mizuki Ishikawa; Shinya Murata
- Web page: https://patentgrep.com/patent/US11306126B2

## CPC

- C07K 14/43518: {from spiders}
- B29C 39/02: for making articles of definite length, i.e. discrete articles
- B29C 55/02: of plates or sheets
- B29C 71/02: Thermal after-treatment {(B29C71/0063 and B29C71/0072 take precedence)}
- C08J 5/18: Manufacture of films or sheets
- C08L 89/00: Compositions of proteins; Compositions of derivatives thereof
- B29K 2089/00: Use of proteins, e.g. casein, gelatine or derivatives thereof, as moulding material
- B29K 2867/003: PET, i.e. polyethylene terephthalate
- B29K 2995/002: Coloured
- B29L 2007/008: {Wide strips, e.g. films, webs}
- C08J 2389/00: Characterised by the use of proteins; Derivatives thereof
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- 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)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

A film of the present invention contains a polypeptide derived from spider silk proteins. The decomposition temperature of the film is 240 to 260° C. The film absorbs ultraviolet light having a wavelength of 200 to 300 nm and has a light transmittance of 85% or more at a wavelength of 400 to 780 nm. The film is transparent and colorless in a visible light region. A method for producing a film of the present invention includes: dissolving a polypeptide derived from spider silk proteins in a dimethyl sulfoxide solvent to prepare a dope; and cast-molding the dope on a surface of a base. Thus, the present invention provides a spider silk protein film that can be formed easily and has favorable stretchability, and a method for producing the same.

## Claims

### Claim 1

A method for producing a spider silk protein film containing a polypeptide derived from spider silk proteins, comprising:
dissolving a polypeptide derived from spider silk proteins in a dimethyl sulfoxide solvent to prepare a dope solution such that the dope solution consists essentially of the polypeptide derived from spider silk proteins and dimethyl sulfoxide (DMSO); and
cast-molding the dope solution on a surface of a base to form the spider silk protein film.

### Claim 2 (depends on 1)

The method for producing a spider silk protein film according to claim 1, wherein the dope solution has a viscosity of 15 to 80 centipoise (cP).

### Claim 3 (depends on 1)

The method for producing a spider silk protein film according to claim 1, wherein the base to be used at the time of the cast molding is a polyethylene terephthalate (PET) film or a release film composed of a PET film and a silicone compound that is fixed on a surface of the PET film.

### Claim 4 (depends on 1)

The method for producing a spider silk protein film according to claim 1, wherein the film is subjected to drying and/or desolvation by at least one selected from vacuum drying, hot-air drying, air drying, and immersion.

### Claim 5 (depends on 4)

The method for producing a spider silk protein film according to claim 4, wherein the film after the drying and/or desolvation is stretched uniaxially or biaxially in water, or the film is subjected to desolvation simultaneously with stretching.

### Claim 6 (depends on 5)

The method for producing a spider silk protein film according to claim 5, wherein the film after the stretching is subjected to thermal fixation by dry heat at 50 to 200° C.

### Claim 7 (depends on 1)

The method for producing a spider silk protein film according to claim 1, further comprising:
dissolving or dispersing a colorant in DMSO to prepare a DMSO coloring liquid; and
adding the DMSO coloring liquid to the dope solution or adding the dope solution to the DMSO coloring liquid and mixing them to prepare the dope solution for film casting.