US20260002300A1

US20260002300A1 - Plant protein based imitation leather fabric

Info

Publication number: US20260002300A1
Application number: US19/090,231
Authority: US
Inventors: Xiaokun Wang; Kening Lang
Original assignee: Uncaged Innovations Inc
Current assignee: Uncaged Innovations Inc
Priority date: 2021-12-21
Filing date: 2025-03-25
Publication date: 2026-01-01
Also published as: US20240141564A1; US12331439B2; WO2025147650A1

Abstract

Imitation leather fabrics comprising a plant protein, plasticizer, and optionally non-proteinaceous polymer and methods of making are disclosed. The fabrics have similar properties to natural leather obtained from animal skin. They are biodegradable, flexible, and stretchable; and can be used as a substitute of natural or synthetic leather.

Description

FIELD OF INVENTION

The present disclosure relates to a monolayer leather-like composition based on plant proteins and products thereof, and method of making. The leather-like composition is durable and has properties like those of natural leather derived from animal hide.

RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Application No. 63/292,256, filed Dec. 21, 2021, which is hereby incorporated herein by reference in its entirety.

BACKGROUND

Leather is a strong, flexible, and durable material obtained from the tanning or chemical treatment of animal hides and used in the manufacture of many products such as clothing, fashion accessories, automobile parts, footwear, handbags, furniture, tools, sport equipment and the like. Typically, leather is obtained from the hides of land-based and aquatic animals such as cattle, sheep, goats, equines, buffalos, hogs, seals, crocodiles, alligators, and the like. The hides of mammals are composed of a thin outer layer or epidermis, a thick central layer known as dermis or corium, and a subcutaneous adipose layer. Conventional leather is obtained from the corium after the epidermis and the adipose layers are removed. Fresh hides contain about 60-70% water and 30-35% protein, 85% of which is collagen. Collagen is the main component of connective tissues in mammals. The combination of rising demand for leather products and the expensive and labor-intensive as well as lengthy process of making leather have led to increase the price of leather products. In addition, the leather making industry has been condemned by animal right organizations and activist for the ongoing animal slaughter to harvest the skin. That has led to an increase demand for a substitute material to conventional leather that can be made mostly from green materials.
Many efforts have been dedicated to obtaining fabrics with the appearance of leather. For example, CN101634109, incorporated herein by reference in its entirety, discloses a composite comprising an aqueous polyurethane resin and anti-foaming agent which can be used as a leather substitute. U.S. Pat. No. 10,287,729, incorporated herein by reference in its entirety, discloses a leather-like material comprises 80-85% of an acrylic resin with inorganic fillers, between 2-4% of a melamine resin as a fixative, between 0.3 and 0.7% of a silicone antifoam, between 4 and 6% of polyethylene glycol, between 0.9 and 1.1% urea and between 1 and 1.5% synthetic acrylic thickeners. WO2011163461, incorporated herein by reference in its entirety, discloses a polyurethane composition comprising dispersing agents and water, which provide a high refractive index. U.S. Pat. No. 8,334,225, incorporated herein by reference in its entirety, discloses stretchable artificial leather comprising a fibrous substrate comprising tricot knitted fabric having a multi-layer knitted texture and a knitted loop density of from 1,000 to 5,000/(2.54 cm)², the tricot knitted fabric further having a back side of a 1 needle swing Denbigh texture and a front side of a 2 to 6-needle swing cord texture, and a polyurethane resin layer laminated on a surface of the fibrous substrate, the stretchable artificial leather having fixed load elongation of from 30 to 60% in each of a longitudinal direction, a lateral direction and a bias direction.
Plant proteins such as wheat gluten have been utilized to develop material for various applications. For example, Qiong Wu [Doctoral Dissertation (2017) School of Chemical Science and Engineering, Stockholm, Sweden], incorporated herein by reference in its entirety, discloses bio-foams and bio-composites comprising wheat gluten. A flame retardant foam was prepared via in situ polymerization of hydrolyzed tetraethyl orthosilicate in a denatured wheat gluten, and its use and physical as well as chemical properties. Also, disclosed adding carbon nanotubes and carbon black and plasticizer to the composite produces material suitable for applications in electromagnetic shielding and electrostatic discharge protection. In addition, Qiong Wu teaches that despite the versatile functionalities of the wheat gluten-based materials, the mechanical properties are often limited due to the brittleness of the dry solid gluten. Roy et al. [(1999) J. Food Sci.64, 57-60], incorporated herein by reference in its entirety, examine the effect of heating film-forming solution on the physical and molecular properties of cast wheat film. A solution is prepared by adding wheat gluten to an alkaline solution of aqueous ethanol and glycerol, and the solution is casted on a glass surface to dry overnight to produce a film with thickness of about 0.1 mm. They suggested that the film could be used as packaging material. U.S. Pat. No. 8,329,601, incorporated herein by reference in its entirety, discloses a biodegradable film comprising starch in an amount in the range of 25% to 85% (w/w), a plant protein in an amount of 5% to 50% (w/w), and plasticizer in an amount in the range of 5% to 50% (w/w). It further discloses embodiments of the film comprising biodegradable polymer such as polyesters and polyamides. The film is disclosed to be used in packaging material such as food products, medical products, garments, garbage, and absorbent article. Zhong and Yuan [J. Appl. Polym. Sci. (2012) DOI: 10.1002/APP.38198], incorporated herein by reference in its entirety, disclose a biodegradable molded blend of wheat gluten and water-born cationic polyurethane-polyester glycol. Also, they disclose the addition of the cationic polyurethane improved the brittleness of the wheat gluten, but do not disclose or suggest that the blend is a suitable leather substitute or the composition of the disclosed invention.
U.S. Pat. No. 5,523,293, incorporated herein by reference in its entirety, discloses a biodegradable soy protein thermoplastic composition formed by the reaction of a mixture of about 25-65 (w/w) % soy protein, about 30-40 (w/w) %, 5-35 (w/w) plasticizer, 0.5-2.5 (w/w) % reducing agent, carbohydrate filler, and about 5-35 (w/w) % water. Also, the patent discloses the composite is extruded into a mold or into a solid pellet. The patent does not disclose a leather-like composite or any material free of reducing agent.
U.S. Pat. No. 5,965,708, incorporated herein by reference in its entirety, discloses gluten protein-based biodegradable or edible film comprising reduced gluten with a reducing agent such as sodium metabisulfite and a plasticizer. The patent does not disclose leather-like material containing gluten or any other plant protein.
U.S. Pat. No. 8,153,176B2, incorporated herein by reference in its entirety, discloses several protein composites including a leather-like material. The disclosed leather-like material is formed by making a mixture of anhydrous collagen and/or scrap of natural leather and glycerol. Other components may be added to the mixture such as polyurethane, crosslinker, and coloring agent may be added to form a paste. The patent does not disclose a leather-like material free of collagen, an animal protein.
U.S. Pat. No. 20,130,337711 discloses a composite material having leather characteristics comprising a natural fiber and a cured resin matrix comprising one or more functionalized fatty acids, functionalized triglycerides, functionalized fatty acids esters, functionalized fatty acids esters. Also, the resin comprises microvoids which render the composite permeable and breathable. The patent document does not disclose leather-like composite comprising plant protein and free of any natural fiber.
JP2003238810A discloses a proteinaceous composition having flexibility and pliability comprising polyurethane. The protein source of the composition could be obtained from plants such as soy and wheat. Also, the composition may contain an aliphatic diamine, alicyclic diamine, and water. The patent document does not disclose a leather-like composite comprising a cross-linked plant protein and plasticizer.
WO2018/038666, incorporated herein by reference in its entirety, discloses a homogeneous wheat gluten-based films having thickness in the range of 1 to 2000 micrometer with improved barrier characteristics to oxygen and oil. It comprises at least 40% wheat gluten and plasticizer in addition to optionally reducing a agent such as sodium sulfite and synthetic polymers such as polyolefins and polyesters. The gluten-based films are devoid of pores and hence is a barrier to oxygen and fat making it suitable for food packaging purposes. The patent document does not disclose leather-like material.
US20210355326A1 and WO2021222755A1, each of which is incorporated herein by reference in its entirety, disclose a multilayered imitation leather composite comprising thin layers of protein and polyurethane composite attached to a substrate such as fiber material, wherein the material contains an amount of protein that is no more than 60 (w/w) % of the sum of the weight of polyurethane and protein. The layers are attached together by glue or stitched together. The patent documents do not disclose a monolayer imitation leather fabric and the composition of the material disclosed are different from that of the invention.
Even though all the above cited leather-like fabrics had achieved some successes, they have had one or more drawbacks such as burn on exposure to flames, lack of flexibility, unlike leather properties, made of non-renewable and biodegradable materials, and formed by multiple layers. Therefore, the object of the invention is to provide a monolayer imitation leather fabric made mostly of renewably produced plants proteins having the appearance and characteristics of natural leather obtainable by a cost effective and simple process without the use of any reducing agent.

SUMMARY OF THE INVENTION

The first aspect of the invention is directed to a method of producing a monolayer imitation leather fabric, said method comprises:

- (a) preparing a paste or dough comprising plant protein powder containing at least 70% (w/w) protein in an amount in the range of 40% to 70% (w/w), plasticizer and/or lubricating agent in an amount in the range of 20% to 40% (w/w), a crosslinking agent in an amount in the range of 2% to 10% (w/w), and optionally one or more non-proteinaceous polymers, and
- (b) compression molding of the paste or dough at a temperature in the range of 90° C. to 160° C. under pressure in the range of 1 to 30 Mpa pressure for a time in the range of 5 to 45 minutes to form a fabric having a thickness in the range from about 0.7 to about 3.0 mm, a tensile strength in a range from about 1.0 Mpa to about 40 Mpa, and an elongation at break in a range from about 20% to about 600%; wherein the amount of protein is 65% or more of the sum of the amounts of the protein and the optionally one or more non-proteinaceous polymers.

In some embodiments of the method, the plasticizer is one or more of sugar, polyol, and derivatives thereof, urea and derivatives thereof, anhydro sugar and derivatives thereof, gelatin, mono and dicarboxylic acid esters; and the lubrication agent is one or more of a fat liquor, synthetic wax, fatty alcohol dicarboxylic acid ester, fatty acid, and surfactant.
In some embodiments of the method, the paste comprises one or more non-proteinaceous polymer selected from oligo and/or polysaccharides, polycaprolactone acid, polylactic-co-glycolic acid, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, polyacrylic acid, polymethyl acrylic acid, polyurethane, polylactic acid, and polyhydroxy propylene, polyurethane-polyamide copolymer, polyurethane-polyester copolymer, polyacrylic acid-polyester copolymer, polyacrylic acid-polyamide copolymer, natural rubber latex, natural rubber, epoxidized natural rubber and the like.
In one embodiment of the method, the one or more non-proteinaceous polymer is latex and polyurethane.
In another embodiment of the method, the one or more non-proteinaceous polymer is latex and a biodegradable polyurethane.
In a particular embodiment of the method, the biodegradable polyurethane is polyester-polyurethane co-polymer or polyamide-polyurethane co-polymer.
In some other preferred embodiment of the method, the polyurethane is polyurethane-polyester copolymer or polyurethane-polyamide copolymer.
In some other preferred embodiments of the method, the crosslinker and one or more non-proteinaceous polymer is epoxidized natural rubber.
In some embodiments of the method, the one or more crosslinking agent is selected from dialdehyde, diimidate esters of dicarboxylic acids, dicarboxylic acid esters of N-hydroxysuccinamide, carbonyldiimidazol, carbodiimide, haloacetyl, dimaleimide, pyridyl dithiol, dichlorotriazine, 4-[(4,6-dichloro-1,3,5-triazin-2-yl)amino)]-benzenesulfonic acid, cyanogen bromide, benzenesulfonic dichlorotriazinyl amide, epoxidized plant oil, epoxidized natural rubber and the like.
In some other preferred embodiments of the method, the crosslinker and one or more lubricant and/or plasticizer agent is epoxidized plant oil.
In a more preferred embodiment of the method, the epoxidized plant oil is soy oil or epoxidized linseed oil.
In some preferred embodiments of the method, the monolayer imitation leather fabric is finished by surface coating of a thin pigmented curable material selected from polyurethane, polyurethane-polyester, or acrylic resin.
In some other preferred embodiments of the method, the monolayer imitation leather fabric is finished by embossing different leather patterns selected from bovine, goat, alligator, crocodile, and reptile skin patterns.
In some embodiments of the method, the monolayer imitation leather fabric is tanned using leather tannages.
In some preferred embodiments of the method, the monolayer tanned imitation leather fabric is retanned using leather retanning reagents.
In some preferred embodiments of the method, the tanned monolayer imitation leather fabric is fatliquored using leather fatliquor reagents.
In some embodiments of the method, the tanned imitation leather fabric is re-plasticized using one or more plasticizer.
The second aspect of the invention is directed to a monolayer imitation leather fabric comprising plant protein powder containing at least 70% (w/w) protein in an amount in the range of 40% to 70% (w/w), plasticizer and/or lubricating agent in an amount in the range of 20% to 40% (w/w), a crosslinking agent in an amount in the range of 2% to 10% (w/w), and optionally one or more non-proteinaceous polymers in an amount in the range of 10% to 35% (w/w), wherein the amount of protein is 65% or more of the sum of the amounts of the protein and the optionally one or more non-proteinaceous polymers.
In some embodiments, the crosslinked protein is one or more of wheat gluten, soy protein isolate, zein protein, pea protein and the like.
In some preferred embodiments, the monolayer imitation leather fabric is biodegradable.
In some embodiments, the monolayer imitation leather fabric has a thickness in a range from about 0.7 to about 3.0 mm, a tensile strength in a range from about 1.0 Mpa to about 40 Mpa, and an elongation at break in a range from about 20% to about 600%.
In some embodiments, the monolayer imitation leather fabric contains one or more plasticizer selected from sugar, polyol and derivatives thereof, urea and derivatives thereof, anhydro sugar and derivatives thereof, gelatin, mono-, di- and tricarboxylic acid esters, and the like.
In some embodiments, the monolayer imitation leather fabric contains glycerol.
In some embodiments, the lubrication agent is one or more of a fat liquor, synthetic wax, fatty alcohol dicarboxylic acid ester, fatty acid, and surfactant.
In some embodiments, the monolayer imitation leather fabric comprises one or more non-proteinaceous polymer selected from one or more oligo-and/or polysaccharide, polycaprolactone acid, polylactic-co-glycolic acid, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, polyacrylic acid, polymethyl acrylic acid, polyurethane, polylactic acid, polyhydroxy propylene, polyurethane-polyamide copolymer, polyurethane-polyester copolymer, polyacrylic acid-polyester copolymer, polyacrylic acid-polyamide copolymer and the like.
In some embodiments, the monolayer imitation leather fabric comprises one or more polysaccharide selected from agar, alginate, chitin, chitosan, cellulose, methylcellulose, cellulose acetate, glucomannan, Gellan gum, gum guar, gum Arabic, locust bean gum, pectin, and xanthan gum.
In some embodiments, the monolayer imitation leather fabric comprises condense or hydrolyzable tannin.
In some embodiments of the monolayer imitation leather fabric, the plant protein is treated with one or more crosslinking agent selected from dialdehyde, diimidate esters of dicarboxylic acids, dicarboxylic acid esters of N-hydroxysuccinamide, carbonyldiimidazol, carbodiimide, haloacetyl, dimaleimide, pyridyl dithiol, dichlorotriazine, 4-[(4,6-dichloro-1,3,5-triazin-2-yl)amino)]-benzenesulfonic acid, cyanogen bromide, benzenesulfonic dichlorotriazinyl amide, epoxidized soy oil, epoxidized natural rubber and the like.
In some embodiments of the monolayer imitation leather fabric, the amount of one or more non-proteinaceous polymers is in the range of about 5% to about 30% (w/w).
In some embodiments, the monolayer imitation leather fabric further comprises a foaming agent selected from surfactant or a blowing agent.
In some embodiments, the monolayer imitation leather fabric comprises a dye or a pigment.
In some preferred embodiments, the monolayer imitation leather fabric comprises gluten protein powder comprising at least 70% protein (w/w) in an amount in the range of 48% to 52% (w/w), glycerol in an amount in the range of 23% to 26% (w/w), epoxidized soy oil in an amount in the range of 2.0 to 3% (w/w), polyurethane in an amount in the range of 7 to 10 (w/w) %, and latex in an amount in the range of 13 to 17 (w/w) %.
In some other preferred embodiments, the monolayer imitation leather fabric comprises gluten protein powder comprising at least 70% (w/w) protein in an amount in the range of 50% to 54% (w/w), glycerol in an amount in the range of 24% to 28% (w/w), epoxidized natural rubber in an amount in the range of 9.0 to 12% (w/w), and polyurethane in an amount in the range of 8 to 12 (w/w) %.
In some other preferred embodiments, the monolayer imitation leather fabric made by the method described herein.
A third aspect of the invention is directed to a product contains the monolayer imitation leather fabric of the invention.
In some embodiments, the product is a footwear.
In some other embodiments pictures, the product is a fashion accessory.
In preferred embodiments, the fashion accessory is selected from handbag, briefcase, belt, clothing item.
In some other embodiments pictures, the product is furniture.
In preferred embodiments, the product is an auto part.

BRIEF DESCRIPTION OF FIGURES

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1A shows a picture of heat-pressed gluten-polyurethane (PU) composites with different types of PUs (1202-1 BONDTHAN™ UD-104, 1202-2 BONDTHAN™ UD-108, and 1203-3 BONDTHAN™ UD-301).

FIG. 1B is a graph showing the tensile strength on gluten-PU composites (1202-1 BONDTHAN™ UD-104, 1202-2 BONDTHAN™ UD-108, and 1203-3 BONDTHAN™ UD-301).

FIG. 1C is a graph showing the strain-at-break (elongation) of gluten-PU composites

(1202-1 BONDTHAN™ UD-104, 1202-2 BONDTHAN™ UD-108, and 1203-3 BONDTHAN™ UD-301).

FIG. 2 is a picture showing the effect of foaming agents on gluten-polyurethane composite. Foaming agent 1: Nouryon Expancel® microspheres 031 DU40, foaming agent 2: Nouryon Expancel® microspheres 461 DU20.

FIG. 3A is a graph showing the tensile strength of gluten-tannin composites.

FIG. 3B is a graph showing the strain-at-break (elongation) of gluten-tannin composites.

FIG. 4 is a picture showing dyed and undyed samples of the monolayer imitation leather fabrics. made from example 5 and 7.

FIG. 5A shows a black-colored polyurethane full coating on top of uncolored monolayer imitation leather fabric.

FIG. 5B shows a card holder made from the monolayer imitation leather fabric

FIG. 5C shows an aniline coating on top of orange-dyed monolayer imitation leather fabric.

FIG. 5D shows a thin layer of white-pigmented spray coating on top of navy blue-dyed monolayer imitation leather fabric.

FIG. 5E shows a dark-green colored polyurethane spray coating on top of uncolored imitation leather fabric. Note: Region 1 is uncoated imitation leather fabric, Region 2 coated imitation leather fabric.

FIG. 6A shows monolayer imitation leather fabrics before tanning processing.

FIG. 6B shows monolayer imitation leather fabric after soaking in water for 1 hour and tanned with Chromium free tannage, Stahl Granofin® Easy F-90 Liq.

FIG. 6C shows a monolayer imitation leather fabric after dyeing with SELLA® Fast Black A dye.

FIG. 6D shows dyed monolayer imitation leather fabrics after fatliquoring.

FIG. 6E shows dried monolayer imitation leather fabric after tanning processing.

FIG. 7A shows the effect of latex on maximum stress.

FIG. 7B shows the effect of latex on strain at a break.

DETAILED DESCRIPTION

In this specification, reference is made in detail to specific embodiments of the invention. Some of the embodiments or their aspects are illustrated in the drawings.
Several aspects of the invention are described herein with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide a full understanding of the features described herein. One having ordinary skill in the relevant art, however, will readily recognize that the features described herein can be practiced without one or more of the specific details or with other methods. The features described herein are not limited by the illustrated ordering of acts or events, as some acts can occur in different orders and/or concurrently with other acts or events, unless otherwise specifically indicated. Furthermore, not all illustrated acts or events are required to implement a methodology in accordance with the features described herein.
The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description and/or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising”.
As used herein, the term “about” or “approximately” means a range of up to 10%, preferably 5%, and more preferably 3% of a given value.
As used herein, the term “substantially” refers to something that can be done to a great extent or degree.
As used herein, the terms “plant protein” refers to any protein obtained from any plant source such as but not limited to wheat, beans, soybeans, peas, lentil, maze and the like.
As used herein, the term “biodegradable” refers to a material that is capable of being decomposed by bacteria or other living organisms.
As used herein, the term “non-proteinaceous polymer” refers to any natural or man-made polymer that contains no more than five different proteinaceous α-L-amino acids. For example, α-L-amino acids such as, but not limited to polyglycine, polylysine, polyaspartic acid, poly-systein, polyglutamic acid and any poly racemic- or D-amino acids the like as well as isomers and thereof, they are considered polyamides non-proteinaceous polymers in this application.
As used herein, the terms “latex” and “rubber” are used interchangeably having the same meaning and include natural or synthetic rubber, i.e., polymerized isoprene.
As used herein, the term “in the amount in the range of X % to Y % include all the ranges within the range. For example, a protein in an amount in the range of 40% to 70% (w/w) include the range 41% to 70%, 41% and 69%, 45% to 65%, 46% to 66% . . . etc.
As used herein, the amount of protein in the composition is the calculated amount of protein in the protein powder. For example, 100 g of protein powder containing 75% protein has 75 g of protein. Also, the amount of protein may be determined in a commercial protein powder preparation spectrophotometrically at wavelength of 280 nm or by reaction with coloring reagents by well-known methods in the art and measuring the absorption at the appropriate wavelength.
The first aspect of the invention is directed to a method of making a monolayer imitation leather fabric. The method comprises a paste or a dough of a mixture of a plant protein powder, one or more crosslinkers, and one or more plasticizers and/or lubricants.
The plant protein powder used in the method of making the imitation leather fabric may be any protein powder from any plant. Many plant protein powders are commercially available or may be obtained for example from grains such as but not limited to wheat, and derivatives thereof such as wheatberries, durum, emmer, semolina, spelt, farina, farro, graham, Khorasan wheat, einkorn wheat and the like; rye; barley; triticale; maize; soybean; pea; beans such as fava beans; lentil, soybean and the like. Many plants protein powders such as wheat gluten, soy protein, pea protein and the like are commercially available. Suitable plant protein powders should contain at least 60 (w/w) % protein, preferably at least 65 (w/w) % protein, preferably at least 70%, more preferably at least 75%, more preferably at least 80% or more protein. In some preferred embodiments of the method, the plant protein is a pea protein powder. In some other embodiments of the method, the plant protein powder comprises a prolamin which is a plant storage protein. Prolamins are a group of plant storage proteins having a high proline and glutamine content. They are found in plants, mainly in the seeds of cereal grains such as wheat, barley, rye, maize, sorghum, and oats; and may be referred to as gluten. Gluten is a water insoluble mixture of prolamins. For example, wheat gluten is composed of mainly two types of proteins: glutenins and gliadins, which in turn can be divided into high molecular and low molecular glutenins and α/β, γ and Ω gliadins. Its homologous seed storage proteins in barley, are referred to as hordein, in rye, secalin; in oats, avenin and in sorghum, kafirin. The storage proteins in other grains, such as maize, referred to as zein, and rice are sometimes called gluten. The paste or the dough may comprise a plant protein powder in an amount in the range of 30 (w/w) % and 90 (w/w) %, preferably in the range 35 (w/w) % and 85 (w/w) %, preferably in the range of 40% to 80% (w/w), preferably in the range of 45 (w/w) % to 75 (w/w) %, preferably in the range of 50 (w/w) % to 75 (w/w) %, preferably in the range of 45 (w/w) % to (w/w) 70%, preferably in the range of 45 (w/w) % to 65 (w/w) %, preferably in the range of 50 (w/w) % to 60 (w/w). In some preferred embodiment, the amount of protein is in the range of 48% (w/w) to 55% (w/w), preferably 49% (w/w) to 53% (w/w), and preferably 49% (w/w) to 52% (w/w).
A plasticizer is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture. There are two types of plasticizers: (1) the primary plasticizer and (2) the secondary plasticizer or extender. The primary plasticizer improves the elongation and softness of the composition. Many examples of the primary plasticizers are known in the art including, but not limited to adipates, azelates, citrates, benzoates, ortho-phthalates, terephthalates, sebacates, and trimellitates esters, sugar, polyol such as but not limited to ethylene glycol, glycerol, sorbitol, xylitol, erythritol, and other reduced sugars, and derivatives and the like thereof, urea and derivatives thereof, anhydro sugar and derivatives thereof. The secondary plasticizer or extender enhances the compatibility and plasticizing effect of the primary plasticizer. It has low volatility and migration. Examples of secondary plasticizer include, but not limited to polychlorinated linear alkanes (chlorinated paraffins), epoxidized soybean oil, epoxidized linseed oil and the like. The paste or dough of the method may contain one or more plasticizer in an amount in the range of 10 (w/w) % to 60 (w/w) %, preferably in the range of 15 (w/w) % to 55 (w/w) %, preferably in the range of 20 (w/w) % to 50 (w/w) %, more preferably in the range of 23 (w/w) % to 45%, and most preferably in the range of 24 (w/w) % to 40 (w/w) %. In some embodiments, the one or more plasticizer in the paste or dough is in an amount in the range of 23 (w/w) % to 28 (w/w) %, and preferably in the range of 23 (w/w) % to 26 (w/w) %.
The term lubricant or lubricating agent is used to describe certain additives incorporated into plastics or composite materials. Lubricants may be added to the paste or dough of the method in amount in the range 0.1% and 5% (w/w), preferably in the range of 0.25% to 4% (w/w), preferably in the range of 0.5% to 3% (w/w), preferably in the range of 0.75% to 2.5% (w/w), preferably in the range of 2% to 3% (w/w) and most preferably in the range of 1% to 2% (w/w). There are three types of lubricants with varying functions, and it is important to distinguish between them. The first type is materials reducing the friction of moldings and other finished products when these are rubbed against adjacent materials which may or may not be of the same composition. Examples of this type includes but not limited to graphite and molybdenum disulfide added which are added to polyamides and other thermoplastics. The second type of lubricants is materials which during processing exude from a polymer composition to the interface between the molten polymer and a metal surface of the processing equipment. The resultant thin fabric layer then helps to prevent the plastics or composite from sticking to the machinery and thus, facilitates processing. Such materials, known commonly as external lubricants, have a low compatibility with the polymer or composite and in addition, often possess polar groups to enhance their affinity to metals. The choice of lubricant will depend not only on the type of paste or dough and composition thereof, but also on processing temperatures involved. Examples of external lubricants of this type include, but not limited to fatty acid, such as but not limited to stearic, palmitic, and myristic acids derivatives and salts thereof, in particular esters and calcium and barium salts; hydrocarbons such as paraffin wax, low molecular weight polyethylene, silicon lubricants, and surfactants. The third type of lubricants comprises low molar mass materials which promote the flow of the polymer in the melt but which unlike plasticizers have little effect on the solid-state properties and are known as internal lubricant. Some external lubricants appear also to function as internal lubricants. Examples of internal lubricants includes, but not limited to amine waxes, Montan wax ester derivatives, glyceryl esters such as, but not limited to glyceryl monostearate, long-chain esters such as cetyl palmitate, fatty alcohol dicarboxylic acids, and surfactants.
The paste or dough may contain one or more non-proteinaceous polymers to modify the properties of the fabric. None-proteinaceous polymer are well-known in the art and commercially available from many suppliers and may be engineered for specific application. They have many uses, see for example Vroman and Tighzert [(2009) Material (Basel) 2(2) 307-344, incorporated herein by reference in its entirety. The non-proteinaceous polymers may be divided into two group: renewable polymers, and synthetic polymers. The renewable polymers are biodegradable and obtained from plants, algae, fungi and bacteria. Examples of renewable polymers include, but not limited to polysaccharides such as but not limited to cellulose, methylcellulose, cellulose acetate, Gellan gum, fungi-derived chitin or chitosan and derivatives thereof starch and derivatives thereof, glucomannan, gum guar (also known as galactomannan), gum Arabic, locust bean gum, xanthan gum, alginate and derivatives thereof, pectin, agar, agarose and derivatives thereof; β-polyhydroxyalkanoate (polyesters) includes but not limited to poly (hydroxybutyrate), natural rubber and derivatives thereof, natural rubber and derivatives thereof such as epoxidized natural rubber, natural rubber latex which is an emulsion of natural rubber microparticles in water, and poly(hydroxybutyrate-co-hydroxyvalerate). In some embodiments of the invention, the non-proteinaceous polymer is not starch.
Synthetic polymers are larger group of polymers and may be also divided into two groups: biodegradable polymers and biodegradable resistant polymers. Biodegradable synthetic polymers include hydrolysable backbone such as aliphatic polyesters such as but not limited to polylactic acid, polyhydroxy propylene, and (polylactic-co-glycolic acid), aromatic-aliphatic co-polyesters, polyamides, polyamide-polyester co-polymers, poly(ester-urethane) and polycarbonates. Examples of synthetic biodegradable polyesters include, but not limited to polyglycolide, polylactide, poly(lactide-co-glycolide), polycaprolactone, poly(butylene succinate) and its co-polymers, poly(p-dioxanone), poly(butylene succinate), poly(ethylene succinate), poly(butylene succinate-co-adipate), polycarbonate and the like. Examples of polyamides include, but not limited to poly--amino acid such as polylysine, polyaspartic acid, polyglutamic acid, polyproline, polyglycine, and the like, poly(succinic acid-tetramethylenediamine), poly(succinic acid-pentamethylenediamine), poly(succinic acid-hexamethylenediamine), poly(succinic acid-polycaprolactam), and the like. Polyamide-polyester co-polymers, also known as polyester-amide, are durable and more readily biodegradable than polyamide (see for example U.S. Pat. Nos. 8,889,821, 9,006,350, 8,080,617, DE4327024 A1, DE19754418 A1, WO0218477 A2, WO2013087903, and Winnacker and Rieger [Polymer Chemistry (2016) issue 46: doi.org/10.1039/C6PY01783E], each of which is incorporated herein by reference in its entirety). They are hybrid polymers containing both ester and amide linkages such as, but not limited to copolymerization of hydroxy acids and amino acids, glycol, lactones and lactams such as aminocaproic acid, and caprolactam, and the like. Another class of hybrid polymer which has suitable characteristics to be incorporated in the monolayer imitation leather fabric of the invention is poly(ester-urethane), also known as poly(ester-urea) are well-known in the art, see for example U.S. Pat. Nos. 8,765,164; 4,279,801; and 2,871,218, each of which is incorporated herein by reference. Poly (ester-urethane) is produced by polymerizing an ester terminated by two hydroxyl groups such as such as hydroxy acid and a glycol with diisocyanate such as but not limited to 1,4-diisocyanatobutane, 2,4-toluene diisocyanate, 4,4′-diphenylmethane diisocyanate, and the like. The properties of the resulting polymer may be engineered for a particular purpose by the choice of the hydroxy acid, the glycol and the diisocyanate. Suitable poly(ester-urethane) polymers are commercially available from various vendors such as Mitsui Takeda Chemicals, Inc under the trademark TAKELAC™, the Liofol Company, which is a division of Henkel Technologies of Dusseldorf, Germany, under the trademark TYCEL™, Rohm and Haas Chemicals L.L.C., LTD of Delaware, under the trademark ADCOTE™, and from UPACOp Adhesives Inc. of Massachusetts under the trademark UNOVERS™. Another biodegradable polymer which can be incorporated into the imitation leather fabric of the invention is polyvinyl alcohol and derivatives thereof such as but not limited to acetate.
The biodegradable resistant polymers may also be utilized in making the imitation leather fabric. Examples of such polymers are well-known in the art including but not limited to vulcanized rubber, vulcanized rubber latex, polyacrylic acid and derivatives thereof, polymethylacrylic acid and derivatives thereof, polyether such as polyethylene glycol (PEG), also known as polyethylene oxide, polypropylene glycol, poly(ethylene glycol co propylene glycol) and the like, polyurethane, polymethacrylate, polyvinyl pyrrolidone, polyacrylic acid, polymethyl acrylic acid, and the like.
The paste or dough of the method may contain one or more non-proteinaceous polymers in an amount in the range of about 1 (w/w) % to about 45 (w/w) %, preferably 5 (w/w) % to about 40 (w/w) %, and more preferably 20 (w/w) % to about 35% (w/w). In some embodiments, the amount of one or more non-proteinaceous polymer in the paste or dough of the method is in the range of 20 (w/w) % to 25 (w/w) %, wherein the amount of protein is 60% or more, preferably 65% or more, preferably 70% or more of the sum of the amounts of the protein and the optionally one or more non-proteinaceous polymers. In some embodiments, the paste or dough contains two or more non-proteinaceous polymers in an amount in the range of 5 (w/w) % to 15 (w/w) %, preferably 8 (w/w) % to 12 (w/w) %, and preferably 7 (w/w) % to 10 (w/w) %. In some embodiments of the method, the amount of protein in the paste or dough is at least 61 (w/w) %, at least 62 (w/w) %, preferably at least 63 (w/w) %, preferably at least 64 (w/w) %, preferably at least 64 (w/w) %, more preferably at least 65 (w/w) %, preferably at least 66 (w/w) %, preferably at least 67 (w/w) %, preferably at least 68 (w/w) %, preferably at least 69 (w/w) %, and preferably at least 70 (w/w) % or more of the sum of the amounts of the protein and the optionally one or more non-proteinaceous polymers.
The plant protein separately or in combination with the plasticizer and/or the non-proteinaceous polymers is crosslinked with one or more crosslinking agent to modify the characteristic of the fabric. Crosslinking agents are well-known in the art and are used to covalently link two functional groups such as amino, carboxyl, sulfhydryl, or hydroxyl on the same polymer chain or different chains to each other through the formation of amide, ester, disulfide, carbamate linkages and thereby modify the properties of the protein or composition thereof. The crosslinker is added to the plant protein alone or to a mixture comprising a plant protein, plasticizer and/or one or more non-proteinaceous polymer in an amount in the range of about 0.5% to about 20% (w/w), preferably about 5% to about 15% (w/w), preferably about 7% to about 12% (w/w), and preferably 10% (w/w). In some embodiments, the amount of the cross-liking reagent is added in an amount in the range of 0.5% to 5% (w/w), preferably 1% to 4% (w/w), and preferably 2% to 3% (w/w). In some preferred embodiments of the method, the amount of the crosslinker is in the range of 2% to 14% (w/w). Many crosslinking reagents are well-known in the art and commercially available in different length and characteristics from several venders such as SIGMA-ALDRICH™, THERMOFISHER SIENTIFIC™ and the like. For example, carbonyldimidazol and carbodiimide such as but not limited to dicyclohexylcarbodiimide activate a carboxyl group for coupling to an amino or hydroxyl group on a polymer chain to form an amide or ester linkages, respectively. Other class of crosslinkers are based on two or more reactive chemical groups such as active esters α-haloacyl compounds, aldehydes, and the like, connected with a spacer of different length. There are two categories of crosslinkers: homo-bifunctional and heterobifunctional. Examples of homo-bifunctional crosslinker include, but not limited to dialdehyde such as but not limited to glutaraldehyde, adipaldehyde and the like; diimidate esters of dicarboxylic acids such as but not limited to dimethyl pimelimidate, dimethyl suberimidate and the like; dicarboxylic acid esters of N-hydroxysuccinamide such as disuccinimidyl glutarate, disuccinimidyl suberate, bis(sulfosuccinimidyl)suberate, tris-(succinimidyl)aminotriacetate, and the like which crosslink two amino groups in close proximity on the same polymer chain or on two different polymer chains by forming amine adducts of the dialdehyde, amidine and amide bonds, respectively. Several sulfhydryl crosslinkers are also well-known in the art such as but not limited to haloacetyl crosslinker such as, but not limited to succinidyl iodoacetate, succinidyl 3-(bromoacetamido)propionate, succinimidyl (4-iodoacetyl)aminobenzoate, and the like; maleimide crosslinkers such as but not limited to N-b-maleimidopropyl-oxysuccinimide ester, N-y-maleimidopropyl-oxysuccinimide ester, m-maleimidobenzoyl-N-hydroxsuccinimide ester, succinimidyl 4-((N-maleimidomethyl)cyclohexane-1-carboxylate and the like; pyridyldithiol crosslinkers such as, but not limited to succinimidyl 3-(2-pyridyldithio)propionate, sulfosuccinimidyl 6-(3′-(2-pyridyldithio)propionamido)hexanoate, PEGylated, long chain succinimidyl 3-(2-pyridyldithio)propionate and the like. Also, commercially available are heterobifunctional crosslinkers which crosslink two different functional groups on the same polymer chain or two polymer chains. Examples of heterobifunctional groups include, but not limited to N-hydroxysuccinamide-haloacetyl, N-hydroxysuccinamide-maleimide, N-hydroxysuccinamide-pyridyldithiol, and the like for linking amino and sulfhydryl groups; dicyclohexylcarbodiimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride for linking carboxyl and amino groups; 3-maleimidopropionic acid hydrazide or succinimidyl 6-(3 (2-pyridyldithio)-propionamido)hexanoate, and the like for linking sulfhydryl and carboxyl groups. Many of the heterobifunctional crosslinkers are available with different spacer length between the two functional groups.
Another class of crosslinkers are photoreactive compounds which form nitrene or free radicals upon exposure UV/Vis light. Examples of photoreactive crosslinkers include but not limited to succinimidyl 4,4′-azipentanoate, N-((2-pyridyldithio) ethyl)-4-azidosalicylamide, N-5-Azido-2-nitrobenzyloxysuccinimide, N-5-Azido-2-nitrobenzyloxysuccinimide and the like.
Another useful reagent for crosslinking polymers is cyanogen bromide. It is particularly useful in activating polysaccharides polymer for crosslinking to other polymers such as polysaccharides, proteins, or any other polymer comprising a free hydroxyl or amino group by forming isourea or imidocarbonate linkages.
In some preferred embodiments, the crosslinking agent is one or more, N-hydroxysuccinimide esters of α-haloacetic acid (α-haloacetyl), dimaleimides, pyridyl dithiols, dichlorotriazines, 4-[(4,6-dichloro-1,3,5-triazin-2-yl)amino)]-benzenesulfonic acid and the like.
In some embodiments of the method, the lubricant comprises a chemical functionality that
can be utilized as a crosslinker. Examples of such a lubricant includes but not limited to epoxidized soybean oil (ESO).
In some other embodiments of the method, the non-proteinaceous polymer comprises a chemical functionality that can be utilized as a crosslinker. Examples of such a non-proteinaceous includes but not limited to epoxidized natural rubber.
The paste or dough of the method may contain a tanning agent in an amount of about 0.1% to about 5%, preferably of about 0.2% to about 4%, more preferably of about 0.3% to about 3%, and most preferably of about 0.5% to about 2% of the weight of the plant protein. There are several known types of tanning agents, known as tannages, which may be used in tanning the imitation leather fabric: vegetable tannins, synthetic tannages, mineral tannages, and aldehyde tannages. Vegetable tannins are natural products polyphenolic compounds found in the bark and leaves of plants. Tannins bind to the proteins and coat them, causing them to become less water-soluble and more resistant to bacterial attack. The process of tanning causes the imitation leather fabric to become more flexible. Several types of tannin products may be used for the imitation leather of the invention. One type is condensed tannins, also known as proanthocyanidins, polyflavonoid tannins, catechol-type tannins, pyrocatecollic type tannins, non-hydrolysable tannins or flavolans; which are polymers formed by the condensation flavans and containing no carbohydrate moiety. Another type is hydrolysable tannin or pyrogallol-type tannin. It is a type of tannin that, on heating with hydrochloric or sulfuric acids, yields gallic or ellagic acids. At the center of a hydrolysable tannin molecule, there is a carbohydrate moiety, usually D-glucose and/or cyclitols like quinic or shikimic acids. Also, other types of tannins are known and used in leather tanning including synthetic tannages, known as syntans; mineral tannages such as but not limited to chromium tannages (chromium (III) salts), aluminum tannages, titanium tannages, zirconium tannages and the like; and aldehyde tannages as well as blends thereof. Tanning compositions are commercially available from many suppliers such as CHEMTAN and STAHL. Examples of tannin preparations useful to make the imitation leather fabric include but not limited to Stahl Granofin® Easy F-90 Liq, CHEMTAN® CHESTNUT KPN, CHEMTAN® CHESTNUT KPS, CHEMTAN® M-50, CHEMTAN CHEMATAN MIMOSA® and CHEMATAN® E-84.
In some embodiment of the method may further comprises a step of tanning the monolayer imitation leather fabric.
In some embodiment of the method, the paste or dough may further comprise a blowing agent which are also known as pneumatogen, in an amount in the range of about 0.5 (w/w) % to about 15 (w/w) %, preferably in the range of about 1 (w/w) % to about 12 (w/w) %, and more preferably in the range of about 1 (w/w) % to about 10 (w/w) % of the weight of the plant protein. A blowing agent is a substance which is capable of producing a cellular structure via a foaming process in a variety of materials that undergo hardening or phase transition, such as polymers, plastics, and metals. They are typically applied when the blown material is in a liquid or a paste state. The cellular structure in a matrix reduces density, increasing thermal and acoustic insulation, while increasing relative stiffness of the original polymer. Examples of blowing agents include but not limited to physical blowing agents such as pentane, isopentane, cyclopentane and the like; chemical blowing agents such as isocyanate and water, azidodicarbonamide, sodium bicarbonate, and the like; and porous particles such as fly ash, vermiculite, and hollow spheres. In some embodiments, the blowing agent is hollow spheres such as but not limited to Nouryon EXPANCEL® microspheres.
Also, the paste or the dough of the method may contain one or more neutral, cationic and anionic surfactants in an amount in the range of about 0.5 (w/w) % to about 15 (w/w) %, preferably in the range of about 1 (w/w) % to about 10 (w/w) %, more preferably in the range of about 3 (w/w) % to about 8 (w/w) %, more preferably in the range of about 4 (w/w) % to about 6 (w/w) %, and most preferably 5 (w/w) % of the weight of the protein.
In some embodiments of the method, the paste or dough may contain one or more coloring agent and/or pigment. The amount and the kind coloring agent may vary depending on the desired color and its intensity. In many instances more than one coloring agent may be used to achieve a desired color. The term “dye” refers to a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant or dye fixative to improve the fastness of the dye on the fiber. In contrast, the term “pigment” refers to colored insoluble material used as a suspension of finely grounded solid particles blended with other materials. Pigments may be organic or inorganic. Most inorganic pigments are brighter and last longer than organic ones. Any number of dye, pigment, and/or combination thereof may be incorporated into the imitation leather fabric to achieve a desired color. Examples of dyes include but not limited to aniline dyes such as mauveine, fuchsin, safranin, induline, and the like, indole dyes such as indigo blue, indigo red, and the like; and acridine dyes such as acridine orange, acridine yellow, acriflavine, gel green, and the like. Examples of pigments include but not limited to cadmium pigments such as cadmium yellow, cadmium red, cadmium green, cadmium orange, cadmium sulfoselenide; cobalt pigments such as cobalt violet, cobalt blue, cerulean blue, aureolin, and the like; copper pigments such as Azurite, Han purple, Han blue, Egyptian blue, Malachite, Paris green and the like; iron oxide pigments such as sanguine, caput mortuum, oxide red, red ochre, yellow ochre, and the like; lead pigments such as lead white, Cremnitz white, Naples yellow, and the like; manganese pigments such as manganese violet and the like; titanium pigments such as titanium yellow, titanium white, titanium black, and the like; mercury pigments such as vermilion and the like; zinc pigments such as zinc white, zinc ferrite, zinc yellow and the like; aluminum powder pigment; carbon pigments such as carbon black, ivory black, and the like; and sulfur based Ultramarine pigments. Also, organic pigments such as alizarine, gamboge, cochineal red, rose madder, indigo, Indian yellow, quinacridone, magenta, pthalo green, pthalo blue, and the like are known. In some embodiment, the paste or dough of the method comprises one or more dye and/or a pigment in an amount in the range 0.01 (w/w) % to 3.0 (w/w) %, preferably 0.02 (w/w) % to 2 (w/w) %, preferably 0.02 (w/w) % to 1.0 (w/w) %, preferably 0.03 (w/w) % to 0.8 (w/w) %, preferably 0.04 (w/w) % to 0.5%, more preferably 0.05 (w/w) % to 0.25 (w/w) %, more preferably 0.07 (w/w) % to 0.15 (w/w) % and most preferably 0.1 (w/w) % of the weight of the protein.
In some embodiments of the method, it may be desirable to incorporate one or more filler in the paste or dough to make the monolayer imitation leather fabric breathable. Imitation leather fabric containing filler may be made breathable by stretching, which causes the protein/polymer to break away from the filer and create microporous passageways. Techniques for forming microporous fabric and films are described, see for example U.S. Pat. No. 7,153,569; U. S. Application Publication 2005/0208294 and 2006/0149199, each of which is incorporated herein by reference in its entirety. The paste or dough may contain filler content in an amount in the range of about 2% to about 25% (w/w), preferably of about 5% to about 20% (w/w), preferably about 10% to about 15% (w/w), preferably of about 5% to about 10% (w/w), based on the weight of the plant protein. The filler may include particles having any desired size, such as those having an average size in the range of about 0.5 to about 10 micrometers, preferably in the range of about 1 to about 8 micrometers, in the range of preferably about 2 to about 6 micrometers and in the range of preferably about 3 to about 4 micrometers. Suitable particles for use as a filler may include inorganic oxides, such as calcium carbonate, calcium oxide, kaolin clay, silica, alumina, barium carbonate, sodium carbonate, titanium dioxide, zeolites, magnesium carbonate, magnesium oxide, aluminum hydroxide, talc, sulfate salts, such as but not limited to barium sulfate, magnesium sulfate, aluminum sulfate, and the like; cellulose-type powders including but not limited to pulp powder, wood powder, and the like; carbon; cyclodextrins; and synthetic polymers (e.g., polystyrene). Other suitable particles are described in U.S. Pat. Nos. 6,015,764; 6,111,163; 5,932,497; 5,695,868; 5,855,999; 5,997,981; and 6,461,457, each of which is incorporated herein by reference in its entirety.
In some embodiments of the method, it may be desired to incorporate fire retardant in the paste or dough. Several types of fire retardant are known. They include but not limited to minerals such as aluminum hydroxide, magnesium hydroxide, red phosphorus, and borate salts, and the like; organohalogen compounds such as chloendic acid derivatives, chlorinated paraffin, decabromodiphenyl ether, decabromodiphenylethane, brominated polystyrene, brominated carbonate oligomers, brominated epoxy oligomers, tetrabromophthalic anhydride, tetrabrombisphenol A, hexabromocyclododecane; organophosphorus compounds such as triphenylphosphate, resorcinol bis diphenyl phosphate, bisphenol A diphenyl phosphate, tricresyl phosphate, phosphonates such as dimethyl methylphosphonate, aluminum diethylphosphonate, and other organic compound such as but not limited to melamine, carboxylic acid, dicarboxylic acid and the like. Some but not all halogenated flame retardants are used in conjunction with inorganic antimony compound such as antimony trioxide, antimony pentaoxide, and sodium antimonate to enhance their efficiencies. Also, the fire retardant may be incorporated into the non-proteinaceous polymer during the polymerization process or the paste or dough of the plant protein and plasticizer during the manufacturing of the monolayer imitation leather fabric in an amount in the range of about 1 (w/w) % to about 25 (w/w) %, preferably about 3 (w/w) % to about 20 (w/w) %, preferably about 5 (w/w) % to about 15 (w/w) %, and preferably about 8 (w/w) % to about 12 (w/w) %, and preferably about 10 (w/w) %.
The paste may be obtained by preparing a suspension of a composition comprising a plant protein powder, plasticizer and/or lubricating agent, one or more crosslinking agent, an optionally one or more non-proteinaceous polymers, and any other desired ingredients including but not limited to blowing agent, filler, fire retardant, dye and/or pigments in aqueous organic solvent. The aqueous organic solvent composition contains water and one or more water miscible organic solvent such as, but not limited to methanol, ethanol propanol, isopropanol, acetone, acetonitrile, tetrahydrofurane, dioxane, and the like. The relative amount of the water to the organic solvent may vary depending on the final composition of the suspension. In some embodiments, the aqueous organic solvent contains water in an amount in the range of 5 (v/v) % to 65 (v/v) %, preferably 10 (v/v) % to 60 (v/v) %, preferably 20 (v/v) % to 55 (v/v) %, more preferably 30 (v/v) % to 50 (v/v) %, and more preferably 50 (v/v) %. In some embodiments, the aqueous organic solvent is 50% aqueous ethanol.
The order of mixing the ingredient in the suspension may vary. In some embodiments, the crosslinking agent is added to a suspension of the plant protein powder, plasticizer, and optionally a non-proteinaceous polymer mixture. In some embodiments, the crosslinker is added to a suspension of the plant protein powder alone. In such a case, the polysaccharide may be activated for crosslinking by a crosslinking reagent such as cyanogen bromide prior to adding the plant protein and other ingredients. Yet in some other embodiments, the plant protein powder may be crosslinked prior to adding all other ingredients. Once the mixture is prepared, the apparent pH is adjusted to about 10 using a base such as alkali metal hydroxide, e.g., sodium hydroxide and potassium hydroxide, and the like, or alkali metal carbonate or phosphate salts, and heated at a temperature in the range of 50° C.-120° C., preferably in the range of 55° C.-110° C., more preferably in the range of 60° C.-100° C., and most preferably in the range of 70° C.-90°C for a time in the range of 2 to 20 minutes, preferably 3 to 15 minutes, and more preferably 5 to 10 minutes. In one embodiment, the mixture is heated at 70° C. for 10 minutes.
After heating, the mixture is evenly spread over flat non-sticky surface such as but not limited to silicone or Teflon®-coated surface, partially dried at room temperature to a paste for a time in the range of 1 to 4 days, preferably 2 to 3 days, and then transferred into a dehydrator to further dry at 40° C. for a time in the range of 1 to 6 days, preferably 2 to 4 days, and preferably 2-3 days. The resulting dried paste is molded by heat compression at a temperature in the range of 60° C. to 200° C., preferably in the range of 65° C. to 180° C., preferably in the range of 70° C. to 160° C., preferably in the range of 70° C. to 150° C., preferably in the range of 80° C. to 140° C., and preferably temperature in the range of 90° C. to 130° C. under pressure in the range of 1 to 40 MPa, preferably in the range 1-30 Mpa, preferably in the range of 3 to 25 Mpa, preferably in the range 5 to 15 Mpa, preferably in the range of 10 to 15 Mpa for a time in the range of 1 to 50 minutes, preferably in the range 1 to 45 minutes, preferably in the range of 5 to 45 minutes, preferably in the range of 1 to 25 minutes, preferably in the range of 3 to 20 minutes, and preferable in the range of 5 to 15 minutes to form a fabric having a thickness in the range of about 0.4 to about 7.0 mm, preferably in the range about 0.6 to about 5 mm, preferably in the range 0.9 to 5 mm, preferably in the range from about 0.7 to about 3.0 mm, and preferably in the range of about 0.9 to about 3 mm.
Another embodiment of the method, a dough is obtained with minimum amount of solvent or without a solvent by mixing all ingredients cited above including a base such as sodium hydroxide or pyridine is prepared, homogenized by any mean, and spread on non-sticky flat surface such as silicon or Teflon®-coated surface and is allowed to air dry to form a sheet as described above. Then, the resulting sheet is heat pressed using heat presser at a temperature in the range of 70° C. to 180° C., preferably 85° C. to 165° C., preferably 100° C. to 150° C. and preferably 120° C. to 140° C. under pressure in the range of 5 to 20 Mpa, preferably, 7 to 15 Mpa, preferably 9 to 12, and preferably 10 Mpa for a time in the range of 5 to 20 minutes, preferably, 7 to 15 minutes, preferably 9 to 12 minutes, and preferably 10 minutes to form the fabric to form a fabric having a thickness in the range of about 0.4 to about 7.0 mm, preferably in the range about 0.6 to about 5 mm, preferably in the range from about 0.7 to about 3.0 mm, and preferably in the range of about 0.9 to about 3 mm.
The resulting row monolayer imitation leather fabric may be subjected to one or more finishing process. In some embodiments of the method, the monolayer imitation leather fabric is tanned using leather tannages such as but not limited to STAHL™. Example of tanning reagent such as STAHL™ Granofin® Easy F-90 Liq, CHEMTAN® CHESTNUT KPN, CHEMTAN® CHESTNUT KPS, CHEMTAN® M-50, CHEMTAN CHEMATAN MIMOSA® and CHEMATAN® E-84. The tanning process include contacting the monolayer imitation leather fabric with one or more tanning reagent for a time in the range of 20 to 90 min, preferably 30 to 60 min, and preferably 40 to 50 min. In some other embodiments of the method, the tanned imitation leather fabric is retanned using leather retanning reagents. Retanning reagents are commercially available from several supplier such as but not limited to Stahl Relugan® soft HF, Relugan® soft AP, Chemtan® R106r, CHEMTAN® S-35, and CHEMTAN® S-52R.
In the retanning process, the leather is given its required specific properties for each leather line or product, as defined by the customer. Softness, fullness, density, elongation, the break of the leather, the leather color, etc. are all adjusted or imparted in the retanning process. The retanning process comprises contacting the tanned monolayer fabric with a retanning reagent for a time tine in the range pf 30 to 180 min, preferably 45 to 150 min, preferably 60 to 120 min, and preferably 70 to 100 min. The tanned imitation leather fabric may be fatliquored using leather fatliquor reagents. Fatliquoring is a process of introducing fat into the leather or the monolayer imitation leather fabric following tannage, but before drying. Fatliquor reagents are sulfonated oil or emulsions of detergent and fat which contain one or more anionic detergents, cationic detergents, neutral detergents, and multiionic detergents. A complete account of the fatliquoring process and the reagents used are fully described by Tony Covington in Tanning Chemistry: The Science of Leather [Chapter 17, pages 392-420, published by the Royal Society of Chemistry, www.rsc.org which is incorporated herein by reference in its entirety.
In some embodiments of the method, it may be desirable to increase the softness of the imitation leather fabric by re-plasticizing the resulting imitation leather fabric using one or more plasticizers described herein.
The imitation leather fabric may be further finished by surface coating of the fabric with a thin pigmented curable material, such as but not limited to polyurethane, polyurethane-polyester, acrylic resin and/or cellulose ester such as cellulose acetate, cellulose propionate, cellulose butyrate, and the like. Another useful finishing materials are tree saps. Other finishing step may include embossing the imitation leather fabric with different leather patterns such as bovine, goat, alligator, crocodile, and reptile skin patterns, geometrical shapes, or animated figures.
The second aspect of the invention is directed to a monolayer imitation leather fabric made by the method described herein.
In some embodiments, the monolayer imitation leather fabric comprises a crosslinked plant protein powder, wherein the plant protein powder contains at least 60 (w/w) % protein, preferably at least 65 (w/w) % protein, preferably at least 70 (w/w) % protein, preferably at least 75 (w/w) % protein, preferably at least 80 (w/w) % protein, in an amount in the range of 10% and 90% (w/w), preferably in the range 15% and 85% (w/w), preferably in the range of 20% to 80% (w/w), preferably in the range of 25% to 75% (w/w), preferably in the range of 30% to 70% (w/w), preferably in the range of 40% to 70% (w/w), preferably in the range of 45% to 65% (w/w), preferably in the range of 50% to 60% (w/w); one or more plasticizer and/or lubricating agent in the range of 10% and 70% (w/w), preferably in the range 15% and 65% (w/w), preferably in the range of 20% to 55% (w/w), preferably in the range of 25% to 50% (w/w), and preferably in the range of 20% to 40% (w/w). In some preferred embodiments, the amount of plasticizer is in the range of 18% to 30% (w/w), preferably in the range of 20% to 28% (w/w), preferably in the range of 23% to 27% (w/w); and optionally one or more non-proteinaceous polymers in an amount in the range of about 1% to about 40% (w/w), preferably 3% to about 35% (w/w), more preferably 5% to about 30% (w/w), more preferably 7% to about 20% (w/w), and more preferably 10 to 15% (w/w), wherein the amount of protein is at least 61(w/w) % or more, at least 62 (w/w) % or more, at least 63 (w/w) % or more, at least 64 (w/w) % or more, at least 65 (w/w) % or more, at least 65 (w/w) %, at least 66 or more, preferably at least 67 (w/w) %, preferably at least 68 (w/w) %, more preferably at least 69 (w/w) %, more preferably at least 70 (w/w) % or more of the sum of the amounts of the protein and the optionally one or more non-proteinaceous polymers.
In some embodiments, the imitation leather fabric contains a non-proteinaceous polymer in the range of about 5 (w/w) % to about 30 (w/w) %.
In one embodiment, the imitation leather fabric comprising gluten protein powder comprising at least 70% protein (w/w) in an amount in the range of about 50% to about 54% (w/w), glycerol in an amount in the range of about 24% to about 28% (w/w), epoxidized natural rubber in an amount in the range of about 9.0 to about 12% (w/w), and polyurethane in an amount in the range of about 8 to about 12 (w/w) %.
In another embodiment, the imitation leather fabric comprising gluten protein powder comprising at least 70% protein (w/w) in an amount in the range of about 48% to about 52% (w/w), glycerol in an amount in the range of about 23% to about 26% (w/w), epoxidized soy oil in an amount in the range of about 2.0 to about 3% (w/w), polyurethane in an amount in the range of about 7 to about 10 (w/w) %, and latex in an amount in the range of about 13 to about 17 (w/w) %.
In some embodiments, the crosslinked protein is one or more of wheat gluten, soy protein isolate, zein protein, pea protein and the like.
In one embodiment, the plant protein is wheat gluten.
In some other embodiments, the plasticizer is one or more of sugar, polyol and derivatives thereof, urea and derivatives thereof, anhydro sugar and derivatives thereof, gelatin, mono and dicarboxylic acid esters, and the like.
In one embodiment, the plasticizer is one or more of sugar, polyol, and derivatives thereof,
urea and derivatives thereof, anhydro sugar and derivatives thereof, gelatin, mono and dicarboxylic acid esters, and the like.
In another embodiment, the plasticizer is glycerol.
In some preferred embodiment, the plant protein is crosslinked with one or more cross-linker selected from dialdehyde, diimidate esters of dicarboxylic acids, dicarboxylic acid esters of N-hydroxysuccinamide, carbonyldiimidazol, carbodiimide, haloacetyl, dimaleimide, pyridyl dithiol, dichlorotriazine, 4-[(4,6-dichloro-1,3,5-triazin-2-yl)amino)]-benzenesulfonic acid, cyanogen bromide, benzenesulfonic dichlorotriazinyl amide, epoxidized soy oil, epoxidized natural rubber and the like. The imitation leather fabric may contain a crosslinker in an amount in the range of 1 (w/w) % to 20 (w/w) %, preferably 1.5 (w/w) % to 18 (w/w) %, and most preferably 2 (w/w) % to 14 (w/w) %.
In one embodiment, the crosslinker is 4-[(4,6-dichloro-1,3,5-triazin-2-yl)amino)]-benzenesulfonic acid.
In another embodiment, the crosslinker is epoxidized plant oil such as but not limited to epoxidized soy oil or lent seed oil.
In yet another embodiment, the crosslinker is functionalized non-proteinaceous polymer such as but not limited to epoxidized natural rubber.
The monolayer imitation leather fabric of the invention may be subjected to one or more treatment such as but not limited to tanning, retanning, coloration by one or more pigment or dye, fatliquired, re-plasticized.
The physical properties of the imitation leather may be engineered for a particular use. In some embodiments, the imitation leather fabric has a thickness in the range of about 0.1 to about 7.0 mm, preferably in the range about 0.2 to about 5 mm, preferably in the range from about 0.3 to about 3.0 mm, and preferably in the range of about 0.5 to about 2.0 mm. Similarly, the tensile strength and elongation of the fabric to a breaking point may vary depending on the intended use of the imitation leather fabric. In some embodiment, the imitation leather fabric has a tensile strength in the range of about 0.5 MPa to about 100 MPa, preferably in the range of about 1.0 MPa to about 80 MPa, preferably in the range of about 2.0 MPa to about 70 MPa, preferably in the range about 5.0 MPa to about 50 MPa. In a particularly preferred embodiment, the imitation leather fabric has tensile strength in the range of about 1.0 MPa to about 40 MPa. In some other embodiments, the imitation leather fabric has an elongation at a breaking point in the range from about 5% to about 1000%, preferably in the range of about 10% to about 800%, preferably in the range of about 20% to about 600%, preferably in the range of about 50% to about 500%, preferably in the range of about 100% to about 400%.
A third aspect of the invention is directed to any product made of or contains one or more imitation leather fabric of the invention. Generally, any product traditionally made from animal leather or imitation leathers can be made with the plant-based protein imitation leather of the invention. The imitation leather of the invention is suitable for making products such as but not limited to footwear such as but not limited to shoes, sandals, flip flops and the like; clothing items such as jackets, coats, skirts, pants, handbags, gloves, belts, and the like; furniture such as chairs, sofas, tabletops and the like; luggage such as suitcases, briefcases, and the like; and book covers. Also, it may be incorporated in automobile parts such as seats, steering wheel cover, gear shifting stick, lining the inside doors and ceiling of a car, and the like. Other product made from the imitation leather of the invention includes but not limited to fashion accessories and sport equipment such as hats, gloves, baseball mitts, footballs, succor balls, baseballs, volleyballs, sports shoes, and the like.

EXAMPLES

Example 1

Preparation of Gluten-Polymer Composite Fabric

Polymer microparticles or waterborne dispersion, such as polyurethane (PU) particles, waterborne PU or polylactic acid (PLA) microparticles, were mixed with wheat gluten powder containing more than 75% protein in a gluten:polymer weight ratio of 8:2. The mixture was plasticized with 40% glycerin based on the protein weight (w/w). A black pigment was added to the plasticized protein and mixed in a dough mixer for 5 minutes. The obtained paste was heat pressed using a manual heat press at 120° C. to 140° C. under 10 MPa pressure for 10 minutes to form the fabric. Figure IA shows a picture of heat-pressed gluten-polyurethane (PU) composites with different types of PUs (1202-1 BONDTHAN™ UD-104, 1202-2 BONDTHAN™ UD-108, and 1203-3 BONDTHAN™ UD-301). FIG. 1B is a graph showing the tensile strength on gluten-PU composites (1202-1 BONDTHAN™ UD-104, 1202-2 BONDTHAN™ UD-108, and 1203-3 BONDTHAN™ UD-301). FIG. 1C is a graph showing the strain-at-break of gluten-PU composites (1202-1 BONDTHAN™ UD-104, 1202-2 BONDTHAN™ UD-108, and 1203-3 BONDTHAN™ UD-301).

Example 2

Preparation of Gluten-Polymer Composite Fabric with Foaming Agent:
Polymer microparticles, such as polyurethane (PU) or polylactic acid (PLA) microparticles, were mixed with wheat gluten powder containing more than 75% protein polymer/gluten ratio is 2:8 (w/w). The mixture was plasticized with 30%-40% glycerol based on the protein weight (w/w), and 2% (w/w based on protein weight) EXPANCEL® microspheres were added to the mixture to form a lightweight and porous structure. The composite was further mixed in a dough mixer for 5 minutes, and the obtained paste was heat pressed using a manual heat press at 120° C. to 140° C. with 10 Mpa pressure for 10 minutes to form a fabric. FIG. 2 shows a picture of a composite fabrics with foaming agent 1 EXPANCEL® 031 DU40, foaming agent 2 EXPANCEL® 461 DU20, and without any foaming agent.

Example 3

Preparation of Gluten Composite Fabric:

Gluten powder was dispensed with 50% aqueous ethanol on a stirring plate to obtain a 10% (w/v) suspension. Glycerin (30-40% w/w) was added as a plasticizer, and the pH of the solution was adjusted to 10 with IM NaOH with continuous stirring. The mixture was heated to 70° C. for 10 minutes, evenly spread over a silicone or Teflon®-coated plate and partially dried at room temperature for two days. The partially dried fabric-forming solution was then transferred into a dehydrator and further dried at 40° C. for 2 or 3 days. The obtained fabric had a thickness in a range from about 0.7 to about 3.0 mm. The dried fabric was further heat pressed at 100° C. to 120° C. under 10 Mpa pressure for 10 minutes.

Example 4

Preparation of Gluten Composite Fabric with Tannins:
Gluten powder was mixed with 50% aqueous ethanol on a stirring plate to obtain a 10% (w/v) suspension. Glycerin (40% w/w of the gluten powder) was added as a plasticizer, and the pH of the solution was adjusted to 4.0 with formic acid with continuous stirring. Condensed tannins or hydrolyzable tannins at the weight ratio of 1% (w/w based on protein weight) were added to the mixture, and the mixture was heated to 70° C. for 10 minutes. The heated fabric-forming solution was then evenly spread over a silicone or Teflon®-coated plate, partially dried at room temperature for two days, and then transferred into a dehydrator and further dried at 40° C. for 2 or 3 days. The obtained fabric had a thickness in the range of about 0.7 to about 3.0 mm. The dried fabric was further heat pressed at 100° C. to 120° C. under 10 Mpa pressure for 10 minutes. FIGS. 3A and 3B are graphs showing the tensile strength and strain-at-break (elongation) of gluten-tannin composites of tannin CHEMATAN MIMOSA® and tannin CHEMATAN E-84ª, respectively.

Example 5

Preparation of Gluten Composite Fabric with Polymethyl Acrylic Acid (PMA):
Gluten powder was mixed with 50% aqueous ethanol on a stirring plate to obtain a 10% (w/v) suspension. Glycerin plasticizer (30-40% w/w of the weight of the gluten powder) was added, and the pH of the solution was adjusted to 10 with IM NaOH with continuous stirring. To the mixture, 10% polymethyl acrylic acid and 10% fat liquor (Truposol® SAM) of the weight of the protein were added, and the mixture was heated to 70° C. for 10 minutes. The heated fabric-forming solution was then evenly spread over a silicone or Teflon®-coated plate, partially dried at room temperature for two days, and then transferred into a dehydrator and further dried at 40° C. for 2 or 3 days. The obtained fabric had a thickness in a range from about 0.7 to about 3.0 mm. The dried fabric was further heat pressed at 100° C. to 120° C. under 10 Mpa pressure for 10 minutes.

Example 6

Preparation of Gluten Composite Fabric with Chemical Crosslinkers:
Gluten powder was mixed with 50% aqueous ethanol on a stirring plate to obtain a 10% (w/v) suspension. Glycerin (30-40% w/w of the weight of the gluten powder) was added as plasticizer, and the pH of the solution was adjusted to 10.0 with IM NaOH with continuous stirring. Fat liquor (5 to 10%, w/w based on the weight of gluten) and 0.05 to 0.25% (w/w based on the weight of gluten) of dye was added to the mixture before adding 2 to 10% (w/w based on dry gluten weight) of chemical crosslinkers (aldehydes, dichlorotriazine derivatives, carbodiimide crosslinkers etc.). The mixture was heated to 70° C. for 10 minutes. The heated fabric-forming solution was then evenly spread over a silicone or Teflon®-coated plate, partially dried at room temperature for two days, and then transferred into a dehydrator and further dried at 40° C. for 2 or 3 days. The fabric obtained had a thickness in a range from about 0.3 to about 3.0 mm. The dried fabric was further heat pressed at 100° C. to 120° C. under 10 Mpa pressure for 10 minutes.

Example 7

Preparation of Gluten Composite Fabrics with Double Reactive Crosslinkers and a Dye
Gluten powder was mixed with 50% aqueous ethanol on a stirring plate to obtain a 10% (w/v) suspension. Glycerol (40% w/w from the weight of the powder gluten) was added as plasticizer, and the pH of the solution was adjusted to 8.0 with sodium carbonate with continuous stirring. Ten percent (w/w based on dry gluten weight) of amine/hydroxy group double reactive crosslinkers Granofin@ Easy F-90 Liq were added to the mixture, and the mixture was heated to 70° C. for 10 minutes. A dye (0.1% (w/w) based on the weight of the gluten powder) was added to the mixture. The heated fabric-forming solution was then evenly spread over a silicone or Teflon®-coated plate, partially dried at room temperature for two days, and then transferred into a dehydrator and further dried at 40° C. for 2 or 3 days. The obtained fabric had a thickness in the range of about 0.3 to about 3.0 mm, and enhanced flexibility FIG. 4 is a picture showing the uncolored and colored imitation leather fabrics of examples 5 and 7, respectively. The tensile strength of the final product ranged from 5-8 Mpa, and the elongation at break ranged from 80% to 120%.

Example 8

Effect of Latex on the Imitation Leather Fabric:

A mixture of 50 g gluten powder containing 37.5 g protein, 25 g of glycerol, 2.5 g of epoxidized soybean oil (ESO) as a lubricant and a cross-linker, 25 g Stahl Nuvera® RU-94-227 suspension containing 35% water-borne polyurethan (PU) in water, and varying amount of 50% natural Latex rubber suspension in water (See table 1 below) was blended until it formed a homogenous dough. The dough is pressed to form a sheet about 2 mm in thickness. The dough sheet was put in between a Teflon® sheet and an embossing paper, then heat pressed for 10 mins at 100° C. After the film was heat-pressed, cool the film down at room temperature and further dry the film under dehydrator at 40° C. for 24 h. FIGS. 7A and 7B show the maximum stress and strain at a break of the three preparations.

TABLE I^(a)

	Gluten	Gluten			PU	PU	Latex	Latex	%
Preparation	Powder	protein	Glycerol	ESO	dispersion	solid	dispersion	solid	PU

1	50	37.5	25	2.5	25	8.75	0	0	11.9
2	50	37.5	25	2.5	25	8.75	15	9.5	10.5
3	50	37.5	25	2.5	25	8.75	25	15.25	8.75

^(a)The amounts listed in the table are measured in grams.

Example 9

A uniform mixture of 500 g of wheat gluten powder, 250 g glycerin and 280 g of Nuvera® RU-94-227 dispersion (solid content 35%) was obtained by using an open two roll mill. To the uniform mixture, 100 g of epoxidized natural rubber (ENR 25 or ENR 50) was added. To prepare pre-vulcanized blends, all chemicals for curing ENR 5 phr (Parts per Hundred Rubber) zinc oxide, 1.5 phr stearic acid, 0.5 phr tetramethylthiuram disulfide, and 2 phr sulfur (rubber vulcanizer insoluble sulfur Ot20 insoluble sulfur, CAS 9035-99-8) were added sequentially into the premixed blends for 5 min for each chemical. The blends were calendared into 3 mm flat sheet and then compression-molded at 120° C. for 10 min at pressure of 5 to 10 MPa.
It will be appreciated that the present disclosure may include any one and up to all of the following examples.
Example 1A. A method of producing a monolayer imitation leather fabric, said method comprises: (a) preparing a paste or dough comprising plant protein powder containing at least 70% (w/w) protein in an amount in the range of about 40% to about 80% (w/w), plasticizer and/or lubricating agent in an amount in the range of about 20% to about 40% (w/w), a crosslinking agent in an amount in the range of about 2% to about 14% (w/w), and optionally one or more non-proteinaceous polymers in an amount in the range about 10% to about 35% (w/w), and (b) compression molding of the paste or dough at a temperature in the range of about 90° C. to about 160° C. under pressure in the range of about 1 to about 30 Mpa pressure for a time in the range of about 5 to about 45 minutes to form a monolayer fabric having a thickness in the range from about 0.5 to about 7.0 mm, a tensile strength in a range from about 1.0 Mpa to about 40 Mpa, and an elongation at break in a range from about 20% to about 600%; wherein the amount of protein is 65% or more of the sum of the amounts of the protein and the optionally one or more non-proteinaceous polymers.
Example 2A. The method of Example 1A, wherein the plasticizer is one or more of sugar, polyol and derivatives thereof, urea and derivatives thereof, anhydro sugar and derivatives thereof, gelatin, mono and dicarboxylic acid esters; and the lubrication agent is one or more of a fat liquor, synthetic wax, fatty alcohol dicarboxylic acid ester, fatty acid, and surfactant.
Example 3A. The method of any one of Examples 1A-2A, wherein the paste comprises one or more non-proteinaceous polymers selected from oligo and/or polysaccharides, polycaprolactone acid, polylactic-co-glycolic acid, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, polyacrylic acid, polymethyl acrylic acid, polyurethane, polylactic acid, and polyhydroxy propylene, polyurethane-polyamide copolymer, polyurethane-polyester copolymer, polyacrylic acid-polyester copolymer, polyacrylic acid-polyamide copolymer, latex and the like.
Example 4A. The method of any one of Examples 1A-3A, wherein the one or more crosslinking agent crosslinking agent are selected from dialdehyde, diimidate esters of dicarboxylic acids, dicarboxylic acid esters of N-hydroxysuccinamide, carbonyldiimidazol, carbodiimide, haloacetyl, dimaleimide, pyridyl dithiol, dichlorotriazine, 4-[(4,6-dichloro-1,3,5-triazin-2-yl)amino)]-benzenesulfonic acid, cyanogen bromide, benzenesulfonic dichlorotriazinyl amide, epoxidized soy oil, epoxidized natural rubber and the like.
Example 5A. The method of any one of Examples 1A-3A, wherein the monolayer imitation leather fabric is finished by surface coating of a thin pigmented curable material selected from polyurethane, polyurethane-polyester, acrylic resin, and cellulose esters.
Example 6A. The method of any one of Examples 1A-5A, wherein the monolayer imitation leather fabric is finished by embossing different leather patterns selected from bovine, goat, alligator, crocodile, and reptile skin patterns.
Example 7A. The method of any one of Examples 1A-6A, wherein the monolayer imitation leather fabric is tanned using leather tannages.
Example 8A. The method of any one of Examples 1A-7A, wherein the tanned monolayer imitation leather fabric is retanned using leather retanning reagents.
Example 9A. The method of any one of Examples 1A-8A, wherein the tanned monolayer imitation leather fabric is fatliquored using leather fatliquor reagents.
Example 10A. The method of any one of Examples 1A-9A, wherein the tanned monolayer imitation leather fabric is re-plasticized using plasticizers.
Example 11A. A monolayer imitation leather fabric made by the method of any one of Examples 1A-10A.
Example 12A. A monolayer imitation leather fabric comprising a plant protein powder containing at least 70% (w/w) protein in an amount in the range of about 40% to about 80% (w/w), plasticizer and/or lubricating agent in an amount in the range of about 20% to about 40% (w/w), a crosslinking agent in an amount in the range of about 2% to about 14% (w/w), and optionally one or more non-proteinaceous polymers in an amount in the range of about 10% to about 35% (w/w), wherein the amount in said leather fabric contains an amount of the plant protein more than 65% of the sum of the amounts of the protein and the optionally one or more non-proteinaceous polymers.
Example 13A. The monolayer imitation leather fabric of Example 12A, wherein the crosslinked protein is one or more of wheat gluten, soy protein isolate, zein protein, pea protein and the like.
Example 14A. The monolayer imitation leather fabric of any one of Examples 12A-13A, wherein the fabric is biodegradable.
Example 15A. The monolayer imitation monolayer leather fabric of any one of Examples 12A-14A, wherein the fabric has a thickness in a range from about 0.7 to about 3.0 mm, a tensile strength in a range from about 1.0 Mpa to about 40 Mpa, and an elongation at break in a range from about 20% to about 600%.
Example 16A. The monolayer imitation leather fabric of any one of Examples 12A-15A, wherein the plasticizer is one or more of sugar, polyol and derivatives thereof, urea and derivatives thereof, anhydro sugar and derivatives thereof, gelatin, mono and dicarboxylic acid esters, and the like.
Example 17A. The monolayer imitation leather fabric of any one of Examples 12A-16A, wherein the polyol is glycerol.
Example 18A. The monolayer imitation leather fabric of any one of Examples 12A-17A, wherein the lubrication agent is one or more of a fat liquor, synthetic wax, fatty alcohol dicarboxylic acid ester, fatty acid, and surfactant.
Example 19A. The monolayer imitation leather fabric of any one of Examples 12A-18A, wherein the fabric comprises one or more non-proteinaceous polymer selected from one or more oligo- and/or polysaccharide, polycaprolactone acid, polylactic-co-glycolic acid, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, polyacrylic acid, polymethyl acrylic acid, polyurethane, polylactic acid, polyhydroxy propylene, polyurethane-polyamide copolymer, polyurethane-polyester copolymer, polyacrylic acid-polyester copolymer, polyacrylic acid-polyamide copolymer and the like.
Example 20A. The monolayer imitation leather fabric of any one of Examples 12A-19A, wherein said polysaccharide is one or more agar, alginate, chitin, chitosan, cellulose, methylcellulose, cellulose acetate, glucomannan, Gellan gum, gum guar, gum Arabic, locust bean gum, pectin, and xanthan gum.
Example 21A. The monolayer imitation leather fabric of any one of Examples 12A-20A, wherein the fabric comprises condense or hydrolizable tannin.
Example 22A. The monolayer imitation leather fabric of any one of Examples 12A-21A, wherein the plant protein is treated with one or more crosslinking reagent.
Example 23A. The monolayer imitation leather fabric of any one of Examples 12A-22A, wherein the one or more crosslinking agent is selected from dialdehyde, diimidate esters of dicarboxylic acids, dicarboxylic acid esters of N-hydroxysuccinamide, carbonyldiimidazol, carbodiimide, haloacetyl, dimaleimide, pyridyl dithiol, dichlorotriazine, 4-[(4,6-dichloro-1,3,5-triazin-2-yl)amino)]-benzenesulfonic acid, cyanogen bromide, benzenesulfonic dichlorotriazinyl amide, epoxidized soy oil, epoxidized natural rubber and the like.
Example 24A. The monolayer imitation leather fabric of any one of Examples 12A-23A, wherein the amount of one or more non-proteinaceous polymers is in the range of about 5% to about 30% (w/w).
Example 25A. The monolayer imitation leather fabric of any one of Examples 12A-24A, further comprises a foaming agent selected from surfactant or a blowing agent.
Example 26A. The monolayer imitation leather fabric of any one of Examples 12A-13A, further comprises a dye or a pigment.
Example 27A. A monolayer imitation leather fabric comprising gluten protein powder comprising at least 70% protein (w/w) in an amount in the range of about 48% to about 52% (w/w), glycerol in an amount in the range of about 23% to about 26% (w/w), epoxidized soy oil in an amount in the range of about 2.0 to about 3% (w/w), polyurethan in an amount in the range of about 7 to about 10 (w/w) %, and latex in an amount in the range of about 13 to about 17 (w/w) %.
Example 28A. A monolayer imitation leather fabric comprising gluten protein powder comprising at least 70% protein (w/w) in an amount in the range of 50% to 54% (w/w), glycerol in an amount in the range of 24% to 28% (w/w), epoxidized natural rubber in an amount in the range of 9.0 to 12% (w/w), and polyurethan in an amount in the range of 8 to 12 (w/w) %.
Example 29A. A product contains the monolayer imitation leather fabric of Example 11A.
Example 30A. The product of Example 29A is any of one of athletic accessories, a footwear, a fashion accessory, furniture, an auto part, home goods, electronic accessories, pet accessories.
Example 31A. The product of Example 30A, wherein the fashion accessory of claim 31 is selected from handbag, briefcase, belt, luggage, apparel and clothing item.
In the foregoing disclosure, implementations of the disclosure have been described with reference to specific example implementations thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of implementations of the disclosure as set forth in the following claims. The disclosure and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

Claims

1. (canceled)

2. A method of producing an imitation leather material, comprising:

mixing (i) grain protein, (ii) plasticizer, (iii) crosslinker, and (iv) rubber to form a composite;

calendaring the composite into a flat sheet; and

heat compressing the calendared flat sheet to form the imitation leather material.

3. The method of claim 2, wherein the grain protein contains at least 70% w/w protein.

4. The method of claim 2, wherein the grain protein comprises wheat gluten.

5. The method of claim 4, wherein the grain protein further comprises rice gluten, barley protein, or maize protein, or any combination thereof.

6. The method of claim 2, wherein the rubber comprises natural rubber latex, natural rubber, or epoxidized natural rubber, or a combination thereof.

7. The method of claim 2, wherein the rubber comprises synthetic rubber or vulcanized rubber, or any combination thereof.

8. The method of claim 2, wherein the plasticizer comprises polyol, fatty acid, or plant oil, or any combination thereof.

9. The method of claim 2, wherein the crosslinker comprises dialdehyde, carbodiimide, or tannin, or any combination thereof.

10. The method of claim 2, further comprising surface coating the imitation leather material with a pigmented curable material.

11. The method of claim 2, further comprising embossing leather patterns on the calendared flat sheet prior to heat compressing the calendared flat sheet.

12. The method of claim 2, wherein the grain protein, plasticizer, crosslinker, and rubber are further mixed with one or more non-proteinaceous polymers.

13. The method of claim 12, wherein one or more non-proteinaceous polymers comprise polyurethane.

14. The method of claim 2, wherein the imitation leather material is formed as a monolayer.

15. The method of claim 2, wherein the grain protein, plasticizer, crosslinker, and rubber are further mixed with a lubricating agent, a dye or a pigment, or any combination thereof to form the composite.

16. The method of claim 2, wherein:

the grain protein comprises wheat gluten and the grain protein contains at least 70% w/w protein;

the rubber comprises natural rubber latex, natural rubber, or epoxidized natural rubber, or a combination thereof;

the plasticizer comprises polyol, fatty acid, or plant oil, or any combination thereof; and

the crosslinker comprises dialdehyde, carbodiimide, or tannin, or any combination thereof.

17. The method of claim 16, wherein the grain protein, plasticizer, crosslinker, and rubber are further mixed with polyurethane.

18. The method of claim 16, wherein the grain protein, plasticizer, crosslinker, and rubber are further mixed with a lubricating agent, a dye or a pigment, or any combination thereof to form the composite.

19. The method of claim 16, wherein the imitation leather material is formed as a monolayer.

20. The method of claim 16, wherein the imitation leather material is biodegradable, flexible, and stretchable.