Biodegradable composition and low-temperature film-forming process using same

Abstract

The present invention relates to the technical field of film-forming compositions. In particular, the present invention relates to a biodegradable composition and a low-temperature film-forming process using same. The biodegradable composition of the present invention comprises a biodegradable polymer, a surfactant, a cross-linking agent, and a first additive.

Description

Biodegradable composition and low-temperature film-forming process using the same Technical Field

[0001] The present invention relates to the technical field of film-forming compositions, and in particular to a biodegradable composition and a low-temperature film-forming process using the same. Background Art

[0002] To enhance the performance of packaging materials (especially paper-based materials), additional films (e.g., films made of petroleum-based materials such as PE, PP, and PET) can be applied to the surface of the packaging material. As environmental regulations become increasingly stringent, higher demands are being placed on the environmental performance of packaging. A growing number of studies are considering using biodegradable materials (e.g., PHA and PLA) to replace traditional petroleum-based materials to improve the environmental performance of packaging.

[0003] When applying biodegradable materials to paper-plastic composite food packaging, two technologies can be used. The first is to use an extruder or injection mold to melt the material to be applied to form a film (also called a lamination), which is then laminated on the substrate. The disadvantages of this technology are low operating speed, high energy consumption, and high requirements for precise temperature control. The second technology is to provide a dispersion (such as a water-based dispersion of a polymer or plastic) to be coated on the substrate, which is initially dried at a temperature of about 100°C to remove as much solvent (such as water) as possible, and then further heated to a higher temperature (higher than the T of the polymer or plastic). m The second method is more popular because it requires less equipment investment.

[0004] The typical characteristics of the second technology mentioned above (i.e. dispersion coating technology) are long heating time and high heating temperature. Moreover, the T of the polymer or plastic currently used in the second technology is m Typically above 150°C. Practical drawbacks include extremely high energy consumption (high film-forming temperature required), high safety risks (fiber dust fire or explosion), and low production efficiency. Furthermore, high-temperature drying reduces the moisture content of the coated paper, impairing its printability. Furthermore, moisture seepage from the coating during high-temperature drying can easily create pinholes, which can degrade barrier properties.

[0005] There is a continuous demand in the art for a film forming process at a mild temperature (referred to herein as a low-temperature film forming process).

[0006] Summary of the Invention

[0007] The present invention provides a biodegradable (barrier) composition and a low-temperature film-forming process using the composition. Compared to known high-temperature film-forming processes (approximately 20-50°C above the melting temperature (Tm) of the polymer or plastic), the present low-temperature film-forming process is characterized by a film-forming temperature lower than the melting temperature of the biodegradable material in the composition. The film-forming temperature of the present low-temperature film-forming process is approximately 50-100°C lower than that of known high-temperature film-forming processes. This technical solution significantly reduces film-forming energy consumption and improves production efficiency.

[0008] The biodegradable composition of the present invention can be used to form a barrier layer. The biodegradable composition of the present invention comprises a biodegradable polymer, a surfactant, a crosslinker, and a first additive, wherein the first additive comprises a liquid crystal emulsifier, a pigment, and / or a water-resistance agent. In a preferred embodiment, the biodegradable composition further comprises a second additive. In a further preferred embodiment, the biodegradable composition further comprises water. In yet another further preferred embodiment, the balance is water.

[0009] 53, 54, 55, 56, 57, 58, 59, 60 wt %, and any subranges consisting of these values.

[0010] In one embodiment, the biodegradable composition comprises 0.01-5 wt % of a surfactant, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0 wt %, and any subranges consisting of these values.

[0011] In one embodiment, the biodegradable composition comprises 0.01-8 wt % of a crosslinking agent, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2. %, 0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8, 8.0 wt%, and any subranges consisting of these point values.

[0012] In one embodiment, the biodegradable composition comprises 0.01-10 wt% of a first additive, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3. %, 9.0%, 9.2%, 9.4%, 9.6%, 9.8%, 10.0%, 11.0%, 12.0%, 13.0%, 14.0%, 15.0%, 16.0%, 17.0%, 18.0%, 19.0%, 20.0%, 21.0%, 22.0%, 23.0%, 24.0%, 25.0%, 26.0%, 27.0%, 28.0%, 29.0%, 30.0%, 31.0%, 32.0%, 33.0%, 34.0%, 35.0%, 36.0%, 37.0%, 38.0%, 39.0%, 40.0%, 41.0%, 42.0%, 43.0%, 44.0%, 45.0%, 46.0%, 47.0%, 48.0%, 49.0%, 50.0%, 51.0%, 52.0%, 53.0%, 54.0%, 55.0%, 56.0%,

[0013] In one embodiment, the biodegradable composition comprises 0.01-8 wt% of a second additive, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2 %. .0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8, 8.0 wt%, and any subranges consisting of these point values.

[0014] In a preferred embodiment, the biodegradable composition comprises:

[0015] 10-60 wt% of a biodegradable polymer;

[0016] 0.01-5 wt% of a surfactant;

[0017] 0.01-8 wt% of a cross-linking agent;

[0018] 0.01-10 wt% of a first additive, wherein the first additive comprises a liquid crystal emulsifier, a pigment, and / or a water resistance agent.

[0019] In a preferred embodiment, the biodegradable composition comprises:

[0020] 10-60 wt% of a biodegradable polymer;

[0021] 0.01-5 wt% of a surfactant;

[0022] 0.01-8 wt% of a cross-linking agent;

[0023] 0.01-10 wt% of a first additive, wherein the first additive includes a liquid crystal emulsifier, a pigment, and / or a water resistance agent; and

[0024] water.

[0025] In another preferred embodiment, the biodegradable composition comprises:

[0026] 10-60 wt% of a biodegradable polymer;

[0027] 0.01-5 wt% of a surfactant;

[0028] 0.01-8 wt% of a cross-linking agent;

[0029] 0.01-10 wt % of a first additive, wherein the first additive includes a liquid crystal emulsifier, a pigment, and / or a water resistance agent;

[0030] 0.01-8 wt% of a second additive; and

[0031] water.

[0032] In one embodiment, the second additive of the present invention includes: a co-crosslinking agent, a nucleating agent, a stabilizer, or a combination thereof.

[0033] Herein, the biodegradable polymer includes polyhydroxyalkanoate (PHA), polylactic acid (PLA), polycaprolactone, polybutylene succinate (PBS), polyethylene glycol, or a combination thereof.

[0034] The biodegradable polymers described herein include homopolymers, copolymers, blends (a blend of at least one homopolymer and at least one copolymer, two or more homopolymers, or two or more copolymers), or a combination thereof.

[0035] In one embodiment, the polyhydroxyalkanoate (PHA) described herein comprises one or more repeating units derived from 2-hydroxybutyrate (2HB), 3-hydroxypropionate (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 4-hydroxyvalerate (4HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), 3-hydroxyoctanoate (3HO), 3-hydroxydecanoate (3HD), or a combination thereof.

[0036] In one embodiment, the surfactant described herein can be an anionic surfactant, a cationic surfactant, a nonionic surfactant, a zwitterionic surfactant, or a combination thereof, preferably a nonionic surfactant.

[0037] Exemplary cationic surfactants include amine salt type surfactants, quaternary ammonium salt type surfactants, heterocyclic type surfactants, Preferably, the exemplary cationic surfactants include long chain alkyl groups (e.g., C 10 -C 20 ) Salts of amines (primary amines, secondary amines, tertiary amines), dodecyldimethylbenzyl ammonium chloride, polyquaternium salts, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, cationic guar gum, etc.

[0038] Exemplary anionic surfactants include long chain fatty acids (e.g., C 10 -C 20 Fatty acid) salts, long chain alkyl (such as C 10 -C 20 ) sulfate, long chain alkyl (such as C 10 -C 20 ) sulfonate, or a combination thereof. Preferably, exemplary anionic surfactants include sodium stearate, magnesium stearate, calcium stearate, sodium palmitate, magnesium palmitate, calcium palmitate, sodium oleate, magnesium oleate, sodium lauryl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, sodium dodecylbenzenesulfonate, dioctyl sodium sulfosuccinate, etc.

[0039] Exemplary nonionic surfactants include polyoxyethylene fatty alcohol ethers, polyoxyethylene fatty acid esters or polyoxyethylene sugar alcohols, fatty acid glycerides, or combinations thereof. For example, nonionic surfactants include polyoxyethylene (e.g., C 10 -C 18, preferably C 12 -C 16 ) fatty alcohol, or polyoxyethylene sorbitol (e.g., Tween, such as Tween 20, 40, 60, 80 or 85) and polyoxyethylene sorbitan (e.g., Span, such as Span 20, 40, 60, 80 or 85), etc.

[0040] Exemplary amphoteric surfactants include betaine-type surfactants.

[0041] In one embodiment, the crosslinking agent includes polyvinyl alcohol (PVA), cellulose or its salt, carboxymethyl cellulose or its salt, hydroxyethyl cellulose or its salt, hydroxypropyl methyl cellulose or its salt, isocyanate, polyamine, polyol, glycidyl ether, acrylic acid, methacrylic acid, acrylates, methacrylates, organosilanes, organic peroxides, polysaccharides, gelatin, or a combination thereof. Exemplary crosslinking agents include polyvinyl alcohol (PVA), sodium cellulose, sodium carboxymethyl cellulose, sodium hydroxypropyl methyl cellulose, diethyltoluenediamine, butanediol glycidyl ether, ethylenediaminetetraacetic acid (EDTA), diisopropyl peroxide (DCP), benzoyl peroxide (BPO), di-tert-butyl peroxide (DTBP), diisopropyl hydroperoxide (DTBP), acrylic acid, hydroxyethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, methyltrimethoxysilane, vinyltriethoxysilane, chloropropyltriethoxysilane, etc.

[0042] Liquid crystal emulsifiers are widely used in the cosmetics field. In one embodiment, the liquid crystal emulsifiers described herein include lecithin liquid crystal emulsifiers, alkyl glycoside liquid crystal emulsifiers, (C8-C 22 ) fatty acid ester liquid crystal emulsifier, phosphate ester liquid crystal emulsifier, long chain (C8-C 22 ) Fatty alcohol liquid crystal emulsifiers, long chain fatty acids (such as C 10 -C 20 fatty acid) liquid crystal emulsifier, or a combination thereof. Exemplary liquid crystal emulsifiers include alkyl (C8-C 22 ) glycosides, long chain (C8-C 22 ) fatty alcohols, long-chain fatty acids (such as C8-C 22 Fatty acids), or combinations thereof. Exemplary liquid crystal emulsifiers include decyl glucoside, cetearyl glucoside, stearyl alcohol, cetyl alcohol, cetearyl alcohol, myristic acid, pentadecanoic acid, hexadecanoic acid or palmitic acid, heptadecanoic acid or pearlic acid, octadecanoic acid or stearic acid, sorbitan stearate, sorbitan laurate, sucrose stearate, sorbitan oleate, glyceryl stearate, PEG-40 stearate, ceteareth 20, polyoxyethylene stearate (also known as polyoxyethylene stearate), or combinations thereof.

[0043] In one embodiment, the co-crosslinking agent described herein comprises a polyol, tetrasodium EDTA, sodium citrate, sodium pyrophosphate, sodium tripolyphosphate, a multifunctional co-crosslinking agent, a free radical co-crosslinking agent, or a combination thereof. Exemplary crosslinking agents include glycerol, dipropylene glycol, trimethylolpropane, pentaerythritol, sorbitol, trimethylolpropane acrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTAMA), ethylene glycol diacrylate (EGDA), ethylene glycol dimethacrylate (EGDMA), N,N'-(1,4-phenylene) bismaleimide, zinc diacrylate (ZDA), zinc dimethacrylate (ZDMA), triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), 1,2-polybutadiene (1,2-PBR), or a combination thereof.

[0044] In one embodiment, the nucleating agent described herein includes talc, calcium oxide, carbon black, calcium carbonate, mica, inorganic pigments, kaolin, sodium succinate, sodium glutarate, sodium hexanoate, potassium benzoate, lithium benzoate, sodium cinnamate, sodium β-naphthoate, metal phosphates, or combinations thereof.

[0045] In one embodiment, the pigment described herein includes china clay, talc, calcium carbonate, titanium dioxide, inorganic pigments (such as chromates, sulfates, silicates, borates, molybdates, phosphates, vanadates, ferrocyanates, hydroxides, sulfides, etc.) or combinations thereof.

[0046] In one embodiment, the stabilizer described herein includes an antioxidant, a heat stabilizer, an anti-aging agent, an anti-ultraviolet agent, a light shielding agent, an impact resistant agent, or a combination thereof.

[0047] In one embodiment, the water-resistance agent described herein includes a resin-type water-resistance agent, a zirconium carbonate-type water-resistance agent, or a combination thereof. Exemplary water-resistance agents include formaldehyde resin water-resistance agents, glyoxal resin water-resistance agents, urea-formaldehyde resin water-resistance agents, melamine formaldehyde resin water-resistance agents, ammonium zirconium carbonate (AZC), potassium zirconium carbonate (PZC), or a combination thereof.

[0048] The inventors surprisingly found that the first additive herein achieves excellent effects. The first additive herein may include a liquid crystal emulsifier, a pigment, a water resistance agent, or a combination thereof.

[0049] In one embodiment, the first additive described herein enables a low-temperature film-forming process. In a preferred embodiment, the first additive described herein can reduce the film-forming temperature when used in film formation (low-temperature film formation). The resulting film has excellent properties, such as good barrier properties, low porosity, and low adhesion to processing equipment.

[0050] In one embodiment, the present invention provides a (film-forming) process comprising the steps of applying a film-forming material to a substrate, and placing the substrate to which the film-forming material is applied in a film-forming device to obtain a film-coated product, wherein the operating temperature of the film-forming device is 60 to 150° C., preferably 80-130° C. In particular, the film-forming material forms a film. In one embodiment, the film-forming material described herein comprises the first additive described herein. In a preferred embodiment, the film-forming material described herein comprises the biodegradable polymer described herein and the first additive. In another preferred embodiment, the film-forming material described herein comprises the biodegradable polymer described herein, a surfactant, and a first additive. In yet another preferred embodiment, the film-forming material described herein comprises the biodegradable polymer described herein, a cross-linking agent, and a first additive. In a most preferred embodiment, the film-forming material described herein comprises the biodegradable polymer described herein, a surfactant, a cross-linking agent and the first additive.

[0051] In a preferred embodiment, the (film forming) process comprises:

[0052] The film-forming material described herein is formulated into a slurry, and optionally, the slurry is transferred into a (fast) grinder and ground until the particle size distribution is stable;

[0053] coating the (optionally ground) slurry on a substrate to obtain a substrate coated with a film-forming material;

[0054] Drying the substrate coated with the film-forming material (for example, in a drying oven at 60 to 120° C.) (for example, for 1 to 10 minutes) to obtain a dried substrate coated with the film-forming material;

[0055] The dried substrate coated with the film-forming material is placed in a film-forming device to obtain a coated product, wherein the operating temperature of the film-forming device is 60 to 150°C, preferably 80-130°C.

[0056] In one embodiment, the first additive described herein achieves excellent effects when used to form a film using a biodegradable (barrier) composition, such as reducing the film-forming temperature (low-temperature film formation). The resulting film has excellent effects, such as good barrier properties, low porosity, and low adhesion to processing equipment.

[0057] In one embodiment, the present invention provides a (film-forming) process comprising the step of applying the biodegradable composition described herein to a substrate. In particular, the biodegradable composition forms a film.

[0058] In a preferred embodiment, the (film forming) process comprises:

[0059] The biodegradable composition described herein is formulated into a slurry, and optionally, the slurry is transferred into a (fast) grinder and ground until the particle size distribution is stable;

[0060] coating the (optionally milled) slurry on a substrate to provide a coated substrate;

[0061] drying the coated substrate (e.g., in a drying oven at 60 to 120° C.) (e.g., for 1 to 10 minutes) to obtain a dried coated substrate;

[0062] The dried coated substrate is placed in a film forming device to obtain a film-coated product, wherein the operating temperature of the film forming device is lower than the melting temperature (Tm) of the biodegradable polymer, for example, 1 to 50° C. lower than Tm. In an alternative embodiment, the operating temperature of the film forming device is 60 to 150° C., preferably 80-130° C.

[0063] In one embodiment, the substrate is selected from paper, paperboard, fiberboard, starch, glass, metal, organic foam, inorganic foam, polymer film, or combinations thereof.

[0064] In one embodiment, the drying operation temperature is 60 to 170 ° C, for example, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170 ° C, and any subrange composed of these points, preferably 90 to 120 ° C.

[0065] In one embodiment, the drying time is 1 to 10 minutes, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 minutes, and any subranges consisting of these points, preferably 1 to 5 minutes.

[0066] In one embodiment, the operating temperature of the film-forming device is 1 to 50°C lower than the melting temperature (Tm) of the biodegradable polymer, that is, in the range of Tm-50 to Tm-1°C. In one embodiment, the operating temperature of the film-forming device is 1 to 50°C lower than the melting temperature (Tm) of the biodegradable polymer, such as 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50°C, and any subranges consisting of these points, preferably 20-40°C lower.

[0067] In one embodiment, the operating temperature of the film forming apparatus is from 60 to 150°C, for example, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150°C, and any subranges consisting of these point values, preferably from 80 to 130°C.

[0068] In one embodiment, the process described herein further comprises applying pressure. In one embodiment, the line pressure of the film forming device is 1-600 kN / m, for example, 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, 800 20, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600 kN / m, and any subranges consisting of these point values, preferably in the range of 60-300 kN / m.

[0069] The Tm herein refers to the melting temperature of a polymer and can be a point value or a range, depending on the actual situation.

[0070] Depending on the actual situation, the melting point described herein can be either a point value or a range. If the melting point is a range, it can be called a melting range.

[0071] The low-temperature film forming process described herein refers to a process of forming a film at a temperature lower than the melting temperature of the polymer used. Accordingly, the low-temperature film forming process described herein refers to forming a film at a temperature lower than the melting temperature of the polymer used.

[0072] As used herein, the terms "slurry," "dispersion," and "solution" are used interchangeably to refer to a mixture of the film-forming material (biodegradable composition) described herein and a solvent (eg, water).

[0073] As used herein, the term "film-coated product" refers to a product having a substrate with a film formed by the film-forming material (biodegradable composition) described herein, or a product obtained by the (film-forming) process described herein. As used herein, the terms "film-coated product" and "film-coated substrate" can be used interchangeably.

[0074] In this document, "film" and "thin film" are used interchangeably. The film described herein refers to a film formed by the (film-forming) process described herein, or a film formed by the biodegradable composition described herein, or a material comprising one or more components of the biodegradable composition described herein.

[0075] The specifications of the films described herein can be expressed in millimeters or micrometers, or in gram weight (g / m 2)express. , 700, 800, 850, 900, 950, 1000 microns, and any subranges thereof, preferably 1 to 500 microns. In one embodiment, the film described herein has a gauge of 0.01 g / m 2 Up to 500g / m 2 , for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500 g / m 2 , and any sub-ranges consisting of these point values, preferably 1 to 200 g / m 2 . DETAILED DESCRIPTION

[0076] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples. The experimental procedures described in the following examples are all conventional procedures unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0077] substrate

[0078] Cardboard, weight 230g / m 2 .

[0079] Biodegradable polymers

[0080] PHA is: 3-hydroxybutyrate-co-3-hydroxyhexanoate (Examples 1-3), melting temperature 145-170°C, molecular weight 300,000-600,000 Daltons; 3-hydroxybutyrate-co-4-hydroxybutyrate (Examples 4-8), melting temperature 145-170°C, molecular weight 300,000-600,000 Daltons.

[0081] surfactants

[0082] Tween 20, chemically pure.

[0083] Sodium oleate, chemically pure.

[0084] crosslinking agent

[0085] The PVA is of type 1788, and the alcoholysis degree is 87-89% (mol / mol).

[0086] Gelatin, food grade high viscosity gelatin.

[0087] Sodium carboxymethyl cellulose, acid-resistant and high-viscosity type.

[0088] First additive:

[0089] Cetearyl Glucoside, melting point 45-55℃.

[0090] Stearic acid polyoxyethylene ether, melting point 56-60℃.

[0091] China clay: average particle size 0.5μm.

[0092] Waterproof Cobb 300 test

[0093] Tested according to TAPPI T 441 standard method, test time 300s.

[0094] Oil resistance test

[0095] Tested according to ASTM F119-82 standard method.

[0096] General steps of conventional high-temperature film forming process:

[0097] 1. Apply the biodegradable composition slurry on the substrate using a coating machine;

[0098] 2. The coated substrate is placed in a hot oven to heat-bake into a film. The temperature of the hot oven is higher than the melting temperature (Tm) of the biodegradable polymer.

[0099] General steps of low temperature film forming process:

[0100] 1. Apply the biodegradable composition slurry on the substrate using a coating machine;

[0101] 2. Place the coated substrate in a hot oven and dry it at a temperature of 105-120°C;

[0102] 3. Use a hot pressing device to perform hot pressing treatment on the dried coated substrate, the hot pressing temperature is 1-50° C. lower than the melting temperature of the biodegradable polymer, and the linear pressure is 60-600 kN / m.

[0103] Example 1

[0104] To demonstrate the effect of liquid crystal emulsifiers on film-forming properties, a coating formulation containing a liquid crystal emulsifier was prepared according to Table 1 and used in the film-forming process provided by the present invention. The specific components of this embodiment are listed in Table 1. The barrier properties of the coating obtained after film formation are shown in Table 2.

[0105] Example 2

[0106] A formulation without a liquid crystal emulsifier was prepared using the same method as in Example 1 and used in a film-forming process. The specific components of Example 2 are shown in Table 1. The barrier properties of the coating obtained after film formation are shown in Table 2.

[0107] Example 3

[0108] This example uses polyoxyethylene stearate as a liquid crystal emulsifier to demonstrate low-temperature film-forming properties. The specific components of Example 3 are shown in Table 1. The barrier properties of the coating obtained after film formation are shown in Table 2.

[0109] Table 1

[0110] Table 2

[0111] a NA means that the barrier performance cannot be characterized due to the inability to form films at low temperatures, and there is no measurement data.

[0112] Example 4

[0113] This example uses fatty acid, stearic acid, as a liquid crystal emulsifier to demonstrate low-temperature film-forming properties. The specific components of Example 4 are shown in Table 3. The barrier properties of the coating obtained after film formation are shown in Table 4.

[0114] Example 5

[0115] A fatty acid-free formulation was prepared using the same method as in Example 4 and used in the film-forming process. The specific components of Example 5 are shown in Table 3. The barrier properties of the coating obtained after film formation are shown in Table 4.

[0116] Table 3

[0117] Table 4

[0118] a NA means that the barrier performance cannot be characterized due to the inability to form films at low temperatures, and there is no measurement data.

[0119] Example 6

[0120] This example uses china clay (average particle size 0.5 μm) as the pigment particles to demonstrate low-temperature film-forming properties. The specific components of Example 6 are shown in Table 5. The barrier properties of the coating obtained after film formation are shown in Table 6.

[0121] Table 5

[0122] Table 6

[0123] Example 7

[0124] This example uses the water-resistance agent ammonium zirconium carbonate (AZC) to demonstrate low-temperature film-forming performance. The specific components of Example 7 are shown in Table 7. The barrier properties of the coating obtained after film formation are shown in Table 8.

[0125] Example 8

[0126] A formulation without ammonium zirconium carbonate was prepared using the same method as in Example 7 and used in the film-forming process. The specific components of Example 8 are shown in Table 7. The barrier properties of the coating obtained after film formation are characterized in Table 8.

[0127] Table 7

[0128] Table 8

[0129] a NA means that the barrier performance cannot be characterized due to the inability to form films at low temperatures, and there is no measurement data.

Claims

1. A biodegradable composition comprising: a biodegradable polymer, a surfactant, a crosslinking agent and a first additive, wherein the first additive comprises a liquid crystal emulsifier, a pigment, and / or a water resistance agent.

2. The biodegradable composition according to claim 1, wherein the biodegradable composition comprises 10-60 wt% of the biodegradable polymer.

3. The biodegradable composition according to any one of the preceding claims, wherein the biodegradable composition comprises 0.01-5 wt% of a surfactant.

4. The biodegradable composition according to any one of the preceding claims, wherein the biodegradable composition comprises 0.01-8 wt% of a cross-linking agent.

5. The biodegradable composition according to any one of the preceding claims, wherein the biodegradable composition comprises 0.01-10 wt% of the first additive.

6. The biodegradable composition according to any one of the preceding claims, wherein the biodegradable polymer comprises polyhydroxyalkanoate (PHA), polylactic acid (PLA), polycaprolactone, polybutylene succinate (PBS), polyethylene glycol, or a combination thereof; preferably, the biodegradable polymer comprises a homopolymer, a copolymer, or a blend (a blend of at least one homopolymer and at least one copolymer, two or more homopolymers, or two or more copolymers); more preferably, the polyhydroxyalkanoate (PHA) comprises one or more repeating units derived from 2-hydroxybutyrate (2HB), 3-hydroxybutyrate (3HB), 3-hydroxypropionate (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 4-hydroxyvalerate (4HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), 3-hydroxyoctanoate (3HO), 3-hydroxydecanoate (3HD), or a combination thereof.

7. The biodegradable composition according to any one of the preceding claims, wherein the surfactant is an anionic surfactant, a cationic surfactant, a nonionic surfactant, a zwitterionic surfactant, or a combination thereof, preferably a nonionic surfactant; more preferably, the nonionic surfactant comprises polyoxyethylene fatty alcohol, polyoxyethylene sorbitol (e.g. Tween), polyoxyethylene sorbitan (e.g. Span).

8. The biodegradable composition according to any one of the preceding claims, wherein the crosslinking agent comprises polyvinyl alcohol (PVA), cellulose or its salts, carboxymethyl cellulose or its salts, hydroxyethyl cellulose or its salts, hydroxypropyl methyl cellulose or its salts, isocyanates, polyamines, polyols, glycidyl ethers, acrylic acids, methacrylic acids, acrylates, methacrylates, organosilanes, organic peroxides, polysaccharides, gelatin, or a combination thereof.

9. The biodegradable composition according to any one of the preceding claims, wherein the liquid crystal emulsifier comprises a lecithin liquid crystal emulsifier, an alkyl glycoside liquid crystal emulsifier, (C8-C 22 ) fatty acid ester liquid crystal emulsifier, phosphate ester liquid crystal emulsifier, long chain (C8-C 22 ) Fatty alcohol liquid crystal emulsifiers, long chain fatty acids (such as C 10 -C 20 fatty acid) liquid crystal emulsifier, or a combination thereof, for example, decyl glucoside, cetearyl glucoside, stearyl alcohol, cetyl alcohol, cetearyl alcohol, myristic acid, pentadecanoic acid, hexadecanoic acid or palmitic acid, heptadecanoic acid or pearlic acid, octadecanoic acid or stearic acid, sorbitan stearate, sorbitan laurate, sucrose stearate, sorbitan oleate, glyceryl stearate, PEG-40 stearate, ceteareth 20, polyoxyethylene stearate (polyoxyethylene stearate), or a combination thereof.

10. The biodegradable composition according to any one of the preceding claims, wherein the pigment comprises china clay, talc, calcium carbonate, titanium dioxide, inorganic pigments (such as chromates, sulfates, silicates, borates, molybdates, phosphates, vanadates, ferrocyanates, hydroxides, sulfides, etc.).

11. The biodegradable composition according to any one of the preceding claims, wherein the water-resistance agent is ammonium zirconium carbonate (AZC) and / or potassium zirconium carbonate (PZC).

12. A (film-forming) process comprising the step of applying a biodegradable composition according to any one of the preceding claims to a substrate.

13. The process according to claim 12, comprising the following steps: formulating the biodegradable composition into a slurry; coating the slurry on a substrate to obtain a coated substrate; drying the coated substrate to obtain a dried coated substrate; The dried coated substrate is placed in a film forming device to obtain a film-coated product, wherein The operating temperature of the film forming device is lower than the melting temperature (Tm) of the biodegradable polymer, for example, 1 to 50°C lower than Tm; or The operating temperature of the film forming device is 60 to 150°C, preferably 80-130°C.

14. The (film-forming) process according to claim 12 or 13, wherein the substrate is selected from paper, paperboard, fiberboard, starch, glass, metal, organic foam material, inorganic foam material, polymer film, or a combination thereof.

15. The (film-forming) process according to any one of claims 12 to 14, further comprising applying a pressure, such as a line pressure of 1 to 600 kN / m, preferably a line pressure of 60 to 300 kN / m.

16. A (film forming) process comprising the following steps: applying a film-forming material to a substrate; Placing the substrate to which the film-forming material is applied in a film-forming device to obtain a coated product, wherein the operating temperature of the film-forming device is 60 to 150° C., preferably 80-130° C.; in, The film-forming material comprises a first additive, wherein the first additive comprises a liquid crystal emulsifier, a pigment, and / or a water-resistant agent.

17. The (film-forming) process according to claim 16, wherein the film-forming material comprises a biodegradable polymer and a first additive, the first additive comprising a liquid crystal emulsifier, a pigment, and / or a water-resistant agent; preferably, the film-forming material comprises a biodegradable polymer, a surfactant, a cross-linking agent and a first additive, the first additive comprising a liquid crystal emulsifier, a pigment, and / or a water-resistant agent.

18. The (film-forming) process according to claim 16 or 17, wherein the substrate is selected from paper, paperboard, fiberboard, starch, glass, metal, organic foam material, inorganic foam material, polymer film, or a combination thereof.

19. The (film-forming) process according to any one of claims 16 to 18, further comprising applying a pressure, such as a line pressure of 1 to 600 kN / m, preferably a line pressure of 60 to 300 kN / m.

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