CN114437515A

CN114437515A - Controllable biodegradable blown film material with easy opening and preparation method and application thereof

Info

Publication number: CN114437515A
Application number: CN202011132889.0A
Authority: CN
Inventors: 郭鹏; 吕明福; 祝桂香; 徐耀辉; 张师军; 张韬毅; 高达利; 许宁; 张伟; 韩翎
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2020-10-21
Filing date: 2020-10-21
Publication date: 2022-05-06

Abstract

The invention relates to an easy-opening controllable biodegradable blown film material, a preparation method and application thereof, belonging to the field of macromolecules. The easy-opening controllable biodegradable film material comprises the following components in parts by weight: 100 parts of degradable copolyester; 0.05-5 parts of an opening agent, preferably 0.1-1.5 parts; the degradable copolyester is aliphatic aromatic copolyester; the opening agent is terpolymer microspheres. The melt index of the degradable copolyester at 190 ℃ under the load of 2.16kg is 0.1-10g/10 min. The invention takes a controllable biodegradable copolymer as base resin, and takes maleic anhydride-styrene-alpha-methyl styrene ternary copolymer pellets as an opening agent to obtain the film material. The film material can be used for preparing a degradable copolyester blown film by adopting an up-blowing method, and has the characteristics of simple and convenient process, good mechanical property, easy opening and biodegradability.

Description

Controllable biodegradable blown film material with easy opening and preparation method and application thereof

Technical Field

The invention relates to the field of macromolecules, in particular to an easy-opening controllable biodegradable blown film material, and a preparation method and application thereof.

Background

The plastic product has the advantages of strong stability, light weight, low production cost and the like, thereby being deeply favored by people. In recent decades, the plastic industry has been rapidly developed, and the use of a large number of plastic products, especially disposable plastic products, brings great convenience to human life. However, due to the chemical stability of general-purpose plastics (PE, PS, PVC, etc.) themselves, they are stable in the environment for a long time when they are abandoned, causing the accumulation of a large amount of plastic wastes in the environment, and causing serious harm to the environment, such as white pollution, agricultural white cancer, etc. With the increasing prominence of environmental problems and the increasing awareness of human environmental protection, the problem of disposing of plastic wastes has become a focus of great concern in the international society. At present, the method for solving the problem mainly comprises a burning method, a landfill method, recycling and the like. The methods are still common methods for treating plastic wastes in many countries at present, and with the increasing prominence of the respective problems, the methods cannot meet the requirement of human beings on environmental protection. Fundamentally solving the problem of plastic waste pollution, seeking a new problem solving way and being urgently realized by human beings. After the degradable plastic is discarded, the degradable plastic can be degraded by using certain factors in the environment, so that the accumulation of the plastic waste in the environment can be reduced, and the problem of environmental pollution caused by the plastic waste is fundamentally solved. Therefore, the development of degradable plastics has become a final approach to solve the problem of plastic waste pollution. Conventionally, the base resin of the film material is generally a general-purpose resin such as PP, PE, PS, or the like. However, the film prepared by the polymer material can not be automatically degraded after the use period is finished, and is easy to pollute soil, rivers and oceans. In recent years, attention has been paid to degradable films in the industry and academia. Poly (butylene succinate-butylene terephthalate) ester (PBST) is a biodegradable high molecular compound and can be biodegraded in a bacterial fermentation mode in a natural environment. The molecular weight of poly (butylene succinate-butylene terephthalate) ester can be regulated and controlled to ensure that the poly (butylene succinate-butylene terephthalate) ester is used in the process

In the prior art, when a polymer film, especially a polyester film, is prepared, because the surface layer of the polymer film has a large number of exposed molecular chain ends and migrated oligomer micromolecules and has polarity, when two layers of films are attached, the leaked molecular chain ends and the micromolecules and the molecular chain ends can mutually permeate and entangle, so that the polymer film is difficult to open; after the films are tightly attached, the Van der Waals force between molecules is obviously reflected due to the close distance; in the film blowing process, the film bubble clamping roller and the winding process, a vacuum tight fit state is formed between films, and the films are not easy to separate; along with the increase of the film-making speed, the electrostatic accumulation on the surface of the film is increased, and the electrostatic adsorption among films is shown, so that the opening of the degradable copolyester film is difficult due to the reasons, and the quality and the product percent of pass of the degradable copolyester film are greatly influenced. In order to overcome the problem of difficult opening of polymer films, it is generally necessary to add corresponding fillers or auxiliaries to the films. Adding a slipping agent to form a slipping agent layer between two adjacent layers of the film, reducing mutual entanglement of exposed molecular chain ends of the film, reducing dynamic and static friction coefficients between the two layers of the film, and adding an antistatic agent to eliminate electrostatic adsorption; the inorganic opening agent is added to generate unevenness on the surface of the film to increase the film distance and reduce the vacuum degree between films, but the degradation products are not completely water and carbon dioxide, and the haze is higher.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides an easy-opening controllable biodegradable blown film material. In particular to an easy-opening controllable biodegradable blown film material and a preparation method and application thereof. The invention takes a controllable biodegradable copolymer as base resin, and takes maleic anhydride-styrene-alpha-methyl styrene ternary copolymer pellets as an opening agent to obtain the film material. The film material can be used for preparing a degradable copolyester blown film by adopting an up-blowing method, and has the characteristics of simple and convenient process, good mechanical property, easy opening and biodegradability.

One of the purposes of the invention is to provide an easy-opening controllable biodegradable blown film material, which comprises the following components in parts by weight:

100 parts of degradable copolyester;

0.05-5 parts of an opening agent, preferably 0.1-1.5 parts, more preferably 0.5-1 part;

wherein the content of the first and second substances,

the degradable copolyester can be aliphatic aromatic copolyester; the aliphatic aromatic copolyester is obtained by reacting components comprising a monomer a, a monomer b, a monomer c and a monomer d; the melt index of the aliphatic aromatic copolyester at 190 ℃ under the load of 2.16kg is 0.1-10g/10 min.

The monomer a can be aromatic dibasic acid and/or ester derivative thereof, preferably terephthalic acid and/or dimethyl terephthalate;

the monomer b can be at least one of C2-C10 aliphatic dihydric alcohol or C3-C10 alicyclic dihydric alcohol, and is preferably 1, 3-propylene glycol and/or 1, 4-butylene glycol;

the monomer C can be C4-C20 aliphatic dibasic acid and/or ester derivatives thereof, preferably at least one of succinic acid, dimethyl succinate, adipic acid or dimethyl adipate;

the monomer d can be at least one of polyalcohol with the functionality of more than 2, polycarboxylic acid with the functionality of more than 2 or anhydride with the functionality of more than 2, and is preferably at least one of pyromellitic dianhydride, glycerol or pentaerythritol.

The content of each monomer can be used in conventional amount as long as the aliphatic aromatic copolyester with long chain branch of corresponding melt index can be obtained, and preferably, the amount of the monomer a, the monomer b, the monomer c and the monomer d can be as follows:

the molar ratio of (a + c) to b is 1: 0.8-3; and/or the presence of a gas in the gas,

the molar ratio of (a + c): d is (100-2000): 1; and/or the presence of a gas in the gas,

the molar ratio of a to c is 0: 100-60: 40, preferably 30: 100-60: 40.

The opening agent is terpolymer microspheres.

The average particle size of the terpolymer microspheres can be 500-1600 nm, and is preferably 800-1600 nm; the terpolymer microsphere can comprise a copolymer structure of a structural unit A, a structural unit B and a structural unit C; wherein the structural unit A is provided by maleic anhydride; the structural unit B is provided by styrene; the structural unit C is provided by alpha-methyl styrene;

based on the total molar weight of the structural units of the terpolymer microsphere copolymer being 100% by mole, the molar content of the structural unit A is 48-51%, the molar content of the structural unit B is 10-45%, and the molar content of the structural unit C is 10-45%. Preferably, the molar content of the structural unit A is 49-50% based on the total molar amount of the structural units of the terpolymer microsphere copolymer being 100% by mole; the molar content of the structural unit B is 15-45%; the molar content of the structural unit C is 10-40%.

The terpolymer microsphere provided by the invention contains more maleic anhydride structural units, so that the obtained random copolymer has stronger polarity and keeps the performance characteristic of better compatibility with polyolefin. The ternary polymerization microsphere is used as the opening agent, the opening agent is better combined with a copolyester interface, the mechanical property, the light transmittance, the haze and other properties are less influenced, and degradation products are carbon dioxide and water.

The easily-opened controllable biodegradable blown film material can also comprise a slipping agent; wherein, based on the use amount of the degradable copolyester as 100 parts by weight,

the using amount of the slipping agent is 0.05-5 parts, preferably 0.05-2 parts;

the slipping agent is selected from stearate and/or organic carboxylic acid amide, wherein the stearate can be selected from calcium stearate and the like, and the organic carboxylic acid amide can be selected from at least one of erucamide, oleamide, stearic acid stearamide and N, N '-ethylene bisstearamide, and is preferably N, N' -ethylene bisstearamide.

The easily-opened controllable biodegradable blown film material can also comprise a nucleating agent; wherein the amount of the nucleating agent is 0.1-20 parts by weight, preferably 0.5-5 parts by weight, based on 100 parts by weight of the degradable copolyester;

the nucleating agent can be selected from at least one of hyperbranched polyamide, low-density polyethylene, ethylene-methacrylic acid ionomer or ethylene-butyl acrylate-glycidyl methacrylate terpolymer.

The easy-opening controllable biodegradable blown film material also comprises an antioxidant; wherein the weight of the antioxidant is 0.05-5 parts by weight, preferably 0.05-2 parts by weight, based on 100 parts by weight of the degradable copolyester.

The antioxidant may be any antioxidant conventionally used in the art. Preferably, the antioxidant is a hindered phenol antioxidant and a phosphite antioxidant which are mixed according to the mass ratio of 1: 3-3: 1; wherein the hindered phenol antioxidant can be selected from at least one of antioxidant 1010 (tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, CAS number: 6683-19-8), 3114(1,3, 5-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, CAS number: 27676-62-6) or 330(1,3, 5-trimethyl-2, 4, 6-tris (3, 5-tert-butyl-4-hydroxybenzyl) benzene; CAS number: 1709-70-2); the phosphite antioxidant may be selected from antioxidant 168 (tris [ 2.4-di-tert-butylphenyl ] phosphite; CAS: 31570-04-4), antioxidant 618 (distearyl pentaerythritol diphosphite; CAS: 3806-34-6) or antioxidant 2, 2' -ethylidenebis (4, 6-di-tert-butylphenyl) fluorophosphite; CAS: 118337-09-0).

The easy-opening controllable biodegradable blown film material can also contain degradable resin which is conventionally used in the field; wherein the weight of the degradable copolyester is 2-20 parts, preferably 4-12 parts, based on 100 parts by weight of the degradable copolyester; and/or, the degradable resin can be selected from at least one of polycaprolactone, succinic acid butylene ester, polyglycolic acid, polylactic acid, Polyhydroxyalkanoate (PHA) and polymethyl ethylene carbonate (PPC).

The invention also aims to provide a preparation method of the easy-opening controllable biodegradable blown film material, which comprises the following steps:

and mixing the components including the degradable copolyester, the opening agent, the slipping agent, the nucleating agent, the antioxidant and the like, and then extruding and granulating to prepare the biodegradable blown film material with controllable opening.

Or mixing the degradable copolyester with the antioxidant for granulation to obtain base resin, mixing with other components including the opening agent, and extruding for granulation.

In the extruding and granulating step, the processing temperature is 150-200 ℃, preferably 160-190 ℃, and the screw rotating speed is 250-350 rpm.

Wherein the content of the first and second substances,

the preparation method of the degradable copolyester can comprise the following steps:

the degradable copolyester can be obtained by reacting components including a monomer a, a monomer b, a monomer c and a monomer d under the action of a catalyst to obtain long-chain branched aliphatic aromatic copolyester, and then carrying out extrusion reaction with organic peroxide;

preferably, the preparation method of the degradable copolyester can comprise the following steps:

1) preparation of long-chain branched aliphatic aromatic copolyester: under the action of a catalyst, mixing a monomer a, a monomer b, a monomer c and a monomer d for esterification reaction, or mixing an esterification product of the monomer a and the monomer b and an esterification product of the monomer c and the monomer d for copolycondensation reaction to obtain the long-chain branched aliphatic aromatic copolyester;

preferably, the melt index of the prepared long-chain branched aliphatic aromatic copolyester at 190 ℃ under the load of 2.16kg is 5-100g/10 min;

2) carrying out extrusion reaction on the long-chain branched aliphatic aromatic copolyester prepared in the step 1) and organic peroxide to obtain the degradable copolyester.

Wherein the content of the first and second substances,

the monomer a is aromatic dibasic acid or ester derivative thereof; the monomer b is C₂-C₁₀Aliphatic diols or C₃-C₁₀One or more of cycloaliphatic diols; the monomer C is C₄-C₂₀An aliphatic dibasic acid or an ester derivative thereof; the monomer d is one or more of polyol with the functionality of more than 2, polycarboxylic acid with the functionality of more than 2 or anhydride with the functionality of more than 2;

preferably, the monomer a is terephthalic acid or dimethyl terephthalate; the monomer b is 1, 3-propylene glycol or 1, 4-butanediol; the monomer c is selected from succinic acid, dimethyl succinate, adipic acid or dimethyl adipate; the monomer d is pyromellitic dianhydride, glycerol or pentaerythritol.

In order to obtain the long-chain branched aliphatic aromatic copolyester with better performance, the monomer a, the monomer b, the monomer c and the monomer d are preferably used in the following amounts: the molar ratio of (a + c): b is 1: 0.8-3, the molar ratio of (a + c): d is 100-.

The catalyst comprises at least one of a first catalyst, a second catalyst, and a third catalyst;

the first catalyst may be selected from the oxides of M, M (OR)₁) n and M (OOCR)₂) M, where M is titanium, antimony or zinc, n and M are each independently of the other the valence of M, R₁Is C₁-C₁₀Alkyl of (A), R₂Is C₁-C₂₀Alkyl groups of (a); preferably, the first catalyst may be selected from at least one of alkoxy titanium, antimony acetate, zinc oxide, antimony oxide and titanium oxide; more preferably, the first catalyst may be selected from tetrabutyl titanate (Ti (OC)₄H₉)₄) At least one of titanium isopropoxide, titanium dioxide, antimony trioxide, antimony acetate and zinc acetate;

and/or the presence of a gas in the gas,

the second catalyst may be RE (R)₃)₃Wherein RE is a rare earth metal element, R₃Selected from the group consisting of halogen, alkoxy, aryloxy, acetylacetonate and R₄At least one of COO-groups, R4 being C₁-C₃₀Alkyl groups of (a); preferably, RE is selected from at least one of lanthanum, cerium, praseodymium, neodymium, terbium, ytterbium, dysprosium, samarium or scandium;

the halogen may be chlorine or bromine, the alkoxy group may be C₃～C₆The aryloxy group may be an aryloxy group comprising at least one benzene ring and/or naphthalene ring, R₄Is C₁～C₂₀Alkyl groups of (a);

more preferably, RE is selected from lanthanum, cerium, praseodymium, neodymium or scandium, the halogen is chlorine or bromine, the alkyl group in the alkoxy group is at least one of isopropyl group, n-butyl group or isoamyl group, the aryl group in the aryloxy group is at least one of 2, 6-di-tert-butyl-4-methylphenyl group or 4-butylphenyl group, and R is₄Is C₃-C₁₈At least one of alkyl groups of (a);

more preferably, the second catalyst may be at least one of lanthanum acetylacetonate, neodymium isopropoxide, lanthanum isopropoxide, scandium isopropoxide, lanthanum stearate, neodymium stearate, lanthanum chloride, tris (2, 6-di-t-butyl-4-methylphenoxy) lanthanum, and a hydrate thereof;

and/or the presence of a gas in the gas,

the third catalyst may be at least one organotin compound; preferably, the third catalyst may be selected from at least one of dibutyl tin oxide, methylphenyl tin oxide, tetraethyl tin, hexaethyl tin oxide, hexacyclohexyl tin oxide, didodecyl tin oxide, triethyl hydroxyl tin, triphenyl hydroxyl tin, triisobutyl tin acetate, dibutyltin diacetate, diphenyl tin dilaurate, monobutyl tin trichloride, tributyl tin chloride, dibutyl tin sulfide, butyl hydroxyl tin oxide, methyl stannic acid, ethyl stannic acid, and butyl stannic acid; further preferably, the third catalyst may be selected from a mixture of at least two of dibutyl tin oxide, tetraethyl tin, triphenyl tin hydroxide, dibutyl tin diacetate, diphenyl tin dilaurate, monobutyl tin trichloride, tributyl tin chloride, dibutyl tin sulfide, butyl tin hydroxide, methyl stannate, ethyl stannate, and butyl stannate; in this case, the amount of each component of the third catalyst may be 10 to 90 mol%, preferably 30 to 70 mol%, based on the total molar amount of the third catalyst, which may be 100 mol% of the agent.

The catalyst of the present invention can be used in an amount conventional in the art, and preferably, the molar ratio of the total amount of the catalyst to the monomer (a + c) can be 1: 1000-20000; preferably 1: (1000 to 10000). And/or the presence of a gas in the gas,

the molar ratio of the first catalyst to the second catalyst to the third catalyst can be (0.1-20): 0.1-10): 1, and is preferably (0.1-10): 1.

The organic peroxide can be selected from organic peroxides with half-life of 0.2-10 min, preferably 0.2-2 min within the processing temperature range;

further preferably, the organic peroxide may be selected from at least one of alkyl peroxides, acyl peroxides, and peroxyesters;

preferably, the organic peroxide may be selected from at least one of 2, 5-bis (t-amylperoxy) -2, 5-dimethylhexane, 2, 5-bis (t-butylperoxy) -2, 5-dimethylhexane, 3, 6-bis (t-butylperoxy) -3, 6-dimethyloctane, 2, 7-bis (t-butylperoxy) -2, 7-dimethyloctane, 8, 11-bis (t-butylperoxy) -8, 11-dimethyloctadecane or a mixture thereof, bis (alkylperoxy) benzene, bis (alkylperoxy) alkyne;

wherein the bis (alkylperoxy) benzene may be selected from the group consisting of α, α '- (t-amylperoxy-isopropyl) benzene, α' -bis (t-butylperoxy-isopropyl) benzene, or mixtures thereof;

the bis (alkylperoxy) alkyne can be selected from 2, 7-dimethyl-2, 7-di (t-butylperoxy) -octadiyne-3, 5,2, 7-dimethyl-2, 7-di (peroxyethyl carbonate) -octadiyne-3, 5,3, 6-dimethyl-3, 6-di (peroxyethyl carbonate) octyne-4, 3, 6-dimethyl-3, 6-di (t-butyl-peroxy) octyne-4, 2, 5-dimethyl-2, 5-di (peroxy-n-propyl-carbonate) hexyne-3, 2, 5-dimethyl-2, 5-di (peroxy-isobutyl carbonate) hexyne-3, 2, 5-dimethyl-2, at least one of 5-di (peroxy ethyl monocarbonate) hexyne-3, 2, 5-dimethyl-2, 5-di ((alpha-cumylperoxy) hexyne-3, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexyne-3.

The organic peroxide can be used in a conventional amount, for example, the amount of the organic peroxide can be 0.01 to 5 wt%, preferably 0.01 to 1 wt% of the amount of the long-chain branched aliphatic aromatic copolyester.

In the step 1), the step (A) is carried out,

in the present invention, the conditions of the esterification reaction and the polycondensation reaction can be conventionally selected according to the prior art. For example, the esterification reaction temperature can be 150-220 ℃; the polycondensation reaction conditions may include: the temperature is 250-270 ℃ and the time is 2-3 hours.

The melt index of the long-chain branched aliphatic aromatic copolyester prepared in the step 1) at 190 ℃ under a load of 2.16kg can be 5-100g/10 min;

in the step 2), the extrusion temperature can be 150-200 ℃, and preferably 160-180 ℃.

Preferably, the copolyester obtained in step 2) has a melt index of 0.1-10g/10min at 190 ℃ under a load of 2.16 kg.

The degradable copolyester may be obtained according to the previous description or according to the description in CN 201910878788.9. The degradable copolyester is prepared by taking aliphatic aromatic copolyester with long branched chain as a main material, extruding, chain extending and tackifying the main material to further increase the length of the branched chain, reducing the melt index and simultaneously increasing the melt strength of the branched chain, and simultaneously matching with corresponding processing aids to prepare a high-strength film product, wherein the film can be completely degraded into micromolecular products such as carbon dioxide, water and the like under natural or composting conditions.

The method for preparing the controllable biodegradable film material easy to open can comprise the step of adding the maleic anhydride-alpha-methylstyrene-styrene ternary copolymer pellets for blending and extruding before extruding and granulating, and can have better opening and high mechanical strength synergistic effect.

In the easily-opened controllable biodegradable film material, degradable copolyester and antioxidant can be mixed and granulated, and then the composite and other components in the composition are mixed; and degradable resins such as polycaprolactone, succinic acid succinate and the like can be added for extrusion granulation. A degradable copolyester film satisfying the objects of the present invention can be prepared.

The preparation method of the opening agent can comprise the following steps:

dissolving components including a polymerization monomer and an initiator in a reaction medium in an inert atmosphere to form a homogeneous solution; after the homogeneous solution is subjected to polymerization reaction to obtain copolymer emulsion suspension, carrying out centrifugal separation to obtain the terpolymer microspheres;

wherein the polymerized monomers comprise components including maleic anhydride, styrene, and alpha-methylstyrene. A molar content of maleic anhydride of 48 to 51% (preferably 49 to 50%) based on the total mass of the polymerized monomers; the molar ratio of the styrene to the alpha-methyl styrene is 9:1-1:9 (preferably 6:1-1: 6).

The mass concentration of the polymerization monomer is 4 to 22 wt%, preferably 15 to 22 wt%, based on the total weight of the homogeneous solution.

The initiator may be an organic peroxide and/or an azo compound. The organic peroxide can be selected from at least one of dibenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate; the azo compound may be selected from azobisisobutyronitrile and/or azobisisoheptonitrile.

The initiator is used in an amount of 0.4 to 4 wt%, preferably 0.5 to 3.6 wt%, based on the total weight of the homogeneous solution.

According to the invention, the reaction medium is an organic acid alkyl ester.

In the invention, organic acid alkyl ester is selected as a reaction medium, and can be matched with the maleic anhydride, the alpha-methylstyrene and the styrene with specific dosage, so that the self-stabilization precipitation polymerization reaction of the maleic acid, the alpha-methylstyrene and the styrene can be realized, no stabilizer or co-stabilizer is required to be added in a polymerization reaction system, the self-stabilization dispersion effect is realized, and the obtained copolymer microsphere has a clean and pollution-free surface.

According to the invention, the organic acid alkyl ester has the general formula R₁COOR₂Wherein R is₁Selected from H, C_1-4At least one of alkyl, phenyl and benzyl of (A), R₂Is C_1-10Alkyl group of (1). Preferably, R₁Is C_1-4Alkyl and/or phenyl of R₂Is C_1-7Alkyl group of (1).

According to the present invention, the reaction medium may be selected from at least one of ethyl formate, propyl formate, isobutyl formate, pentyl formate, ethyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, iso-pentyl acetate, benzyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, iso-pentyl butyrate, ethyl isovalerate, iso-pentyl isovalerate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, iso-pentyl benzoate, methyl phenylacetate and ethyl phenylacetate.

In the present invention, the polymerization reaction is carried out in an inert atmosphere, which may be provided by an inert gas, such as nitrogen, which is conventional in the art.

According to the invention, the polymerization conditions comprise: the polymerization temperature is 60-95 ℃, preferably 65-76 ℃; the polymerization time is 2-24 h, preferably 4-8 h.

The reactor or the reaction equipment in the preparation method of the invention is the reactor or the reaction equipment which is common in the prior art.

In the invention, in the presence of a reaction medium, maleic anhydride, alpha-methyl styrene and styrene are copolymerized according to the method defined by the invention in a copolymerization mode, the dosage of the maleic anhydride and the molar ratio of the styrene to the alpha-methyl styrene in a polymerization monomer are regulated and controlled, the self-stable dispersion of a polymerization system is realized, the prepared polymer is in a microspherical shape with excellent uniformity, no stabilizer, precipitator and other additives are required to be additionally added in the polymerization process, the self-stable dispersion effect is realized, the obtained copolymer microsphere has the characteristics of uniform particle size and clean surface, the dispersibility in the medium is good, and aggregation is avoided.

In the invention, in order to obtain the copolymer microspheres with uniform particles and excellent morphology, the inventor researches the feeding ratio among maleic anhydride, alpha-methylstyrene and styrene in the polymerization process, and researches show that when the feeding amount of each polymerization monomer meets the range defined by the invention, the copolymer microspheres with uniform particles, excellent particle morphology and clean particle surfaces can be prepared.

The terpolymer microsphere opening agent of the present invention may be obtained according to the foregoing description or with reference to the description in CN 201911018149.1. In order to realize the self-stabilization of a polymerization system and further prepare the copolymer microspheres with uniform particle size and clean and pollution-free surface, the inventor researches the conditions of polymerization reaction. Research shows that when the polymerization temperature is 60-95 ℃ and the polymerization time is 2-24 hours, a stable self-stabilization system is formed in the polymerization system, in the system, polymerization monomers of maleic anhydride, alpha-methyl styrene and styrene are polymerized to form microspheres, and the microspheres are not aggregated in a medium and have good dispersibility.

The invention also aims to provide a film prepared from the easy-opening controllable biodegradable blown film material. The film meets the environmental protection requirement, is controllably degradable, is easy to open, has low production cost and is suitable for large-scale production.

According to the invention, the thickness of the film can be adjusted according to requirements and specific processes. Preferably, the thickness of the film can be 5-100 μm, preferably 10-20 μm;

and/or the presence of a gas in the gas,

the tensile break stress of the film is greater than 18MPa, preferably greater than 25MPa, and may be, for example, from 25 to 100 MPa.

Preferably, the longitudinal tensile strength of the degradable copolyester blown film is more than 18MPa, and the transverse tensile strength of the degradable copolyester blown film is more than 16 MPa; preferably, the longitudinal tensile strength is 24MPa or more and the transverse tensile strength is 20MPa or more.

Preferably, the longitudinal elongation at break of the degradable copolyester blown film is more than 250%, and the transverse elongation at break of the degradable copolyester blown film is more than 300%; preferably, the elongation at break in the machine direction is 300% or more and the elongation at break in the transverse direction is 350% or more.

Preferably, the light transmittance of the degradable copolyester blown film is more than 89%.

The fourth purpose of the invention is to provide a preparation method of the film prepared by the easy-opening controllable biodegradable blown film material. The preparation method can comprise the following steps: carrying out blow molding on the easy-opening controllable biodegradable blow molding film material to form a film;

preferably, the first and second electrodes are formed of a metal,

the film blowing temperature can be 150-210 ℃, and is preferably 175-195 ℃; and/or the presence of a gas in the gas,

in the blow molding film forming process, the blow-up ratio can be 1.5-3, preferably 2-2.5.

The invention relates to a preparation method of a film prepared from an easy-opening controllable biodegradable blown film material, in particular to a preparation method of a degradable copolyester blown film, which comprises the following steps:

I) mixing and granulating degradable copolyester and an antioxidant, preferably, the weight ratio of the degradable copolyester to the antioxidant is 100: (0.05-0.5) to obtain a base resin;

II) (1) dissolving a polymerization monomer and an initiator in a reaction medium in an inert atmosphere to form a homogeneous solution;

(2) after the homogeneous solution is subjected to polymerization reaction to obtain copolymer emulsion suspension, carrying out centrifugal separation to obtain the terpolymer microspheres;

wherein the polymerization monomer is maleic anhydride, styrene and alpha-methyl styrene; a molar content of maleic anhydride of 48 to 51%, based on the total mass of the polymerized monomers; the molar ratio of styrene to alpha-methylstyrene is from 9:1 to 1: 9.

III) mixing the base resin obtained in the step I) with the compound obtained in the step II), adding auxiliary agents such as a nucleating agent and a slipping agent, carrying out extrusion granulation, and carrying out blow molding on the obtained granules to form a film.

It is preferably extruded and pelletized by a twin-screw extruder and then blown into a film by a film blowing machine.

Preferably, the extrusion temperature is 150-200 ℃, preferably 170-190 ℃; the rotation speed of the screw is 250-350 rpm.

The extrusion temperature refers to the extrusion temperature set by the extrusion equipment, such as an extruder. The film blowing temperature refers to the film opening temperature of film blowing equipment such as a film blowing machine.

According to the invention, the used film blowing machine can be a downward blowing water-cooled type, a flat blowing water-cooled type or a traditional upward blowing water-cooled type degradable copolyester film blowing machine set.

The fifth purpose of the invention is to provide the application of the film in the application of agricultural mulching films and packaging bag films.

The film prepared by the easy-opening controllable biodegradable film material is a degradable copolyester blow molding film, has the advantages of biological controllable degradation, easy opening and the like, and can be applied to occasions with higher requirements on the biological degradability and opening of plastic products, such as packaging, agricultural films and the like.

Compared with the prior art, the invention has the following beneficial effects:

1) the degradable copolyester composition provided by the invention has good mechanical properties, so that the degradable copolyester composition is suitable for excellent materials in the fields of packaging, protective films, agricultural greenhouse film mulching films and the like. The preparation method of the degradable copolyester composition provided by the invention is simple and effective and is easy to operate.

2) The manufactured degradable blown film has a controllable degradation structure, can be buried and degraded in garbage, does not cause secondary pollution, and meets the requirement of circular economy.

Drawings

FIG. 1 is an infrared spectrum (FI-IR chart) of a terpolymer microsphere SYXQ101 described in example 1 of the present application. 1785cm^-1、1850cm^-1Characteristic absorption peak of anhydride group, 709cm^-1Is a special absorption peak of a benzene ring, 1020-1300cm^-1Is a characteristic peak of the C-N group, on the basis of which it can be determined that the polymer is a maleic anhydride/styrene/alpha-methylstyrene copolymer.

Fig. 2 is a Scanning Electron Microscope (SEM) image of the terpolymer microspheres SYXQ101 described in example 1 of the present application, and it can be seen that the particles of the copolymer microspheres are uniform, and the surfaces of the particles are clean and not contaminated.

Detailed Description

The present invention will be further described with reference to the following examples. However, the present invention is not limited to these examples.

The invention will be further described with reference to the following examples, but it should be noted that: the present invention is by no means limited to these examples.

Examples and comparative examples all other materials were commercially available.

The test methods for the data in the following examples and comparative examples are as follows:

observing and measuring the form and the size of the terpolymer microsphere by adopting a Scanning Electron Microscope (SEM);

the infrared spectrogram of the copolymer is tested by FI-IR;

the content of each structural unit in the copolymer is adopted¹H NMR is used for testing by¹And (4) measuring the content of each structural unit according to the ratio of the peak area corresponding to the characteristic hydrogen in the corresponding structural unit in the H NMR.

Gel Permeation Chromatography (GPC) determined the molecular weight and molecular weight distribution of the polymer, using Tetrahydrofuran (THF) as a solvent, on a Waters-208 (with a Waters 2410 RI detector, 1.5mL/min flow rate, 30 ℃) instrument, molecular weight calibrated to styrene standards.

The crystallization temperature (Tc) and melting temperature (Tm) of the polymer were determined by Differential Scanning Calorimetry (DSC) on a Perkin Elmer Pyris 1 apparatus with two heating scans of each sample from-100 ℃ to 250 ℃ at a heating rate of 20 ℃/min.

Determination of Melt Index (MI): the melt flow rate of the polymer was measured by a melt index meter model CS-127, scientific instruments, Inc., at 190 ℃ under a load of 2.16kg, according to ISO1133-2005, Standard "determination of melt mass flow rate and melt volume flow rate of thermoplastic plastics".

Measurement of light transmittance and haze: the assay was performed as described in the national Standard GB/T2410-.

Examples 1 to 6 are provided to illustrate the degradable copolyester blown film of the present invention which is easy to open and has good light transmittance and the method for preparing the same.

Example 1

This example illustrates the degradable copolyester composition, the terpolymer microspheres and the degradable copolyester blown film provided by the present invention.

(1) Preparation of ternary copolymer microsphere SYXQ 101:

adding 11g of maleic anhydride, 0.6g of azobisisobutyronitrile, 10.62g of alpha-methylstyrene, 1.04g of styrene and 87.8g of isoamyl acetate into a 500mL three-neck flask, uniformly mixing the materials, introducing nitrogen for 20 minutes, transferring the three-neck flask into a water bath at 60 ℃, reacting for 5 hours, and after the reaction is finished, centrifugally separating the obtained polymer emulsion suspension for 20 minutes by a centrifuge at the rotating speed of 2000rad/min to obtain polymer solid A111.04g, wherein the yield of the corresponding polymer is 51.4%. The particle size of the polymer microspheres is 1200 nm. Wherein the molar ratio of styrene to alpha-methylstyrene is 1: 9.

The polymer microspheres a1 were subjected to 1H NMR measurement, and it was found that the molar content of the maleic anhydride structural unit was 50%, the molar content of the styrene structural unit was 10%, and the molar content of the α -methylstyrene structural unit was 40%, based on the total molar amount of the respective structural units in the polymer.

(2) Preparation of degradable copolyester composition 101:

1) under the action of a catalyst, 423.8g (2.55mol) of monomer a terephthalic acid (PTA), 650g (7.21mol) of monomer b 1, 4-Butanediol (BDO), 330g (2.79mol) of monomer c Succinic Acid (SA) and 1g (0.01mol) of monomer d glycerol are mixed and subjected to esterification reaction to obtain long-chain branched aliphatic-aromatic copolyester, and the melt index of the long-chain branched aliphatic-aromatic copolyester is 23g/10min at 190 ℃ under the load of 2.16 kg; the catalyst contained 0.245g of tetrabutyltitanate (available from Beijing Chemicals), 0.31g of lanthanum stearate, 0.1g of dibutyltin oxide (available from Beijing chemical three factories), 0.14g of triphenylhydroxytin (available from Beijing Chemicals);

2) 500g of the long-chain branched aliphatic aromatic copolyester prepared in the step 1) and 2.5g of 3, 6-bis (tert-butylperoxy) -3, 6-dimethyloctane are subjected to extrusion reaction at 170 ℃ of an extruder to prepare copolyester, and the melt index of the prepared copolyester at 190 ℃ under the load of 2.16kg is 1.9g/10 min;

(3) preparation of blown film 101:

500g of the obtained copolyester is mixed with 10101 g of antioxidant, 1682 g of antioxidant, 1.5g of slipping agent N, N' -ethylene distearamide, SYXQ 1014 g of opening agent and 25g of nucleating agent DuPont Elvaloy4170 resin, and the mixture is added into a double-screw extruder to be subjected to melt extrusion granulation at 170 ℃ to prepare a film blowing material;

(4) and (3) blowing the film blowing material on a film blowing machine, wherein the temperature of a neck ring mold is 180 ℃, and the blowing-up ratio is 2.3:1, so that a film with the thickness of 10 mu m is obtained.

The obtained film was subjected to performance tests, and the results of the tests on optical properties, thermal properties and barrier properties are shown in table 1, and the mechanical properties are shown in table 2.

Example 2

(1) Preparation of ternary copolymer microsphere SYXQ102

Adding 10g of maleic anhydride, 0.89g of azobisisobutyronitrile, 9.44g of alpha-methyl styrene, 2.08g of styrene and 87.8g of butyl butyrate into a 500mL three-neck flask, uniformly mixing the materials, introducing nitrogen for 20 minutes, transferring the three-neck flask into a 70 ℃ water bath, reacting for 5 hours, and after the reaction is finished, centrifugally separating the obtained polymer milky suspension for 20 minutes by a centrifuge at the rotating speed of 2000rad/min to obtain polymer solid A211.72g, wherein the yield of the corresponding polymer is 55.0%. The particle size of the polymer microsphere is 1500 nanometers. Wherein the molar ratio of styrene to alpha-methylstyrene is 2: 8.

Subjecting the polymer microsphere A2 to¹H NMR measurement revealed that the molar content of the maleic anhydride structural unit was 48%, the molar content of the styrene structural unit was 12% and the molar content of the alpha-methylstyrene structural unit was 40%, based on the total molar amount of the respective structural units in the polymer.

(2) Preparation of degradable copolyester 102

1) Preparation of long-chain branched aliphatic aromatic copolyester: under the action of a catalyst, 423.8g (2.55mol) of monomer a terephthalic acid, 570.8g (7.5mol) of monomer b 1, 3-propylene glycol, 438.4g (3mol) of monomer c dimethyl succinate and 1g (0.0046mol) of monomer d pyromellitic dianhydride are mixed for esterification reaction, and the prepared long-chain branched aliphatic aromatic copolyester has a melt index of 15g/10min at 190 ℃ under the load of 2.16 kg; the catalyst contained 0.245g of tetrabutyltitanate (available from Beijing Chemicals), 0.31g of lanthanum stearate, 0.1g of dibutyltin oxide (available from Beijing chemical three factories), 0.14g of triphenylhydroxytin (available from Beijing Chemicals);

2) 500g of the long-chain branched aliphatic aromatic copolyester prepared in the step 1) and 2.5g of 3, 6-bis (tert-butylperoxy) -3, 6-dimethyloctane are subjected to extrusion reaction at 170 ℃ of an extruder to prepare copolyester, and the melt index of the prepared copolyester at 190 ℃ under the load of 2.16kg is 2.0g/10 min;

(3) preparation of blown film 102

Mixing 500g of the copolyester, 31141g of antioxidant, 1682 g of antioxidant, 2.25g of slipping agent oleamide, SYXQ1021.5g of opening agent and 15g of nucleating agent Dupont Surlyn8920 resin, adding into a double-screw extruder, and performing melt extrusion granulation at 170 ℃ to obtain a blown film material;

(4) and blowing the film blowing material on a film blowing machine, wherein the temperature of a neck ring mold is 185 ℃, and the blowing ratio is 2.2:1, so as to obtain a film with the thickness of 10 mu m.

Example 3

(1) Preparation of ternary copolymer microsphere SYXQ103

10.2g of maleic anhydride, 0.7g of azobisisobutyronitrile, 8.26g of alpha-methyl styrene, 3.12g of styrene and 80g of butyl benzoate are added into a 500mL three-neck flask, after the materials are uniformly mixed, nitrogen is introduced for 20 minutes, the three-neck flask is moved into a water bath at 80 ℃, the reaction is carried out for 5 hours, after the reaction is finished, the obtained polymer emulsion suspension is centrifugally separated by a centrifuge at the rotating speed of 2000rad/min for 20 minutes, the polymer solid A316.38g is obtained, and the corresponding polymer yield is 77.3%. The particle size of the polymer was 1600 nm. Wherein the molar ratio of styrene to alpha-methylstyrene is 3: 7.

The polymer microsphere a3 was subjected to 1H NMR measurement, and it was found that the molar content of the maleic anhydride structural unit was 51%, the molar content of the styrene structural unit was 15%, and the molar content of the α -methylstyrene structural unit was 34%, based on the total molar amount of the structural units in the polymer.

(2) Preparation of degradable copolyester 103

1) Preparation of long-chain branched aliphatic aromatic copolyester: under the action of a catalyst, 679.6g (3.5mol) of monomer a dimethyl terephthalate, 570.8g (7.5mol) of monomer b 1, 3-propylene glycol, 657.6g (4.5mol) of monomer c adipic acid and 0.7g (0.005mol) of monomer d pentaerythritol are mixed for esterification reaction, and the prepared long-chain branched aliphatic aromatic copolyester has the melt index of 40g/10min at 190 ℃ under the load of 2.16 kg; the catalyst contained 0.245g of tetrabutyltitanate (available from Beijing Chemicals), 0.31g of lanthanum stearate, 0.1g of dibutyltin oxide (available from Beijing chemical three factories), 0.14g of triphenylhydroxytin (available from Beijing Chemicals);

2) 500g of the long-chain branched aliphatic aromatic copolyester prepared in the step 1) and 2.5g of 3, 6-bis (tert-butylperoxy) -3, 6-dimethyloctane are subjected to extrusion reaction at 170 ℃ of an extruder to prepare copolyester, and the melt index of the prepared copolyester at 190 ℃ under the load of 2.16kg is 2.6g/10 min;

(3) preparation of blown film 103

Mixing 500g of the copolyester with 3301g of an antioxidant, 6182g of an antioxidant, 2g of a slipping agent stearic acid stearamide, SYXQ1032.25g of an opening agent and 25g of Elvaloy4170 resin, adding the mixture into a double-screw extruder, and performing melt extrusion granulation at 170 ℃ to obtain a film blowing material;

4) and (3) blowing the film blowing material on a film blowing machine, wherein the temperature of a neck ring mold is 180 ℃, and the blowing-up ratio is 2.2:1, so that a film with the thickness of 10 mu m is obtained.

Example 4

(1) Preparation of ternary copolymer microspheres SYXQ 104:

9.6g of maleic anhydride, 0.85g of azobisisobutyronitrile, 7.08g of alpha-methylstyrene, 4.16g of styrene and 85.8g of butyl acetate are added into a 500mL three-neck flask, after the materials are uniformly mixed, nitrogen is introduced for 20 minutes, the three-neck flask is moved into a water bath at 65 ℃ for reaction for 5 hours, and after the reaction is finished, the obtained polymer emulsion suspension is centrifugally separated by a centrifuge at the rotating speed of 2000rad/min for 20 minutes to obtain polymer solid A416.63g, wherein the yield of the corresponding polymer is 79.0%. The particle size of the polymer microsphere is 1500 nanometers. Wherein the molar ratio of styrene to alpha-methylstyrene is 4: 6.

The polymer microspheres a4 were subjected to 1H NMR measurement, and it was found that the molar content of the maleic anhydride structural unit was 49%, the molar content of the styrene structural unit was 20%, and the molar content of the α -methylstyrene structural unit was 31%, based on the total molar amount of the respective structural units in the polymer.

(2) Preparation of degradable copolyester 104:

1) preparation of long-chain branched aliphatic aromatic copolyester: under the action of a catalyst, 423.8g (2.55mol) of monomer a terephthalic acid (PTA), 650g (7.21mol) of monomer b 1, 4-Butanediol (BDO), 330g (2.79mol) of monomer c Succinic Acid (SA) and 1g (0.01mol) of monomer d glycerol are mixed for esterification reaction, and the melt index of the prepared long-chain branched aliphatic aromatic copolyester is 40g/10min at 190 ℃ under the load of 2.16 kg; the catalyst contained 0.174g of tetrabutyl titanate (available from Beijing Chemicals), 0.071g of dibutyl tin oxide (available from Beijing chemical three Mills), 0.099g of triphenyl hydroxyl tin (available from Beijing Chemicals), and 0.22g of lanthanum stearate;

2) performing extrusion reaction on 500g of the long-chain branched aliphatic aromatic copolyester prepared in the step 1) and 5g of 2, 7-bis (tert-butylperoxy) -2, 7-dimethyloctane at 180 ℃ in an extruder to prepare copolyester, wherein the melt index of the prepared copolyester at 190 ℃ under the load of 2.16kg is 2.3g/10 min;

(3) preparing a blown film 104;

1) 104500 g of the copolyester degradable copolyester, 3301g of antioxidant, 2.5g of antioxidant 2,2 '-ethylidene bis (4, 6-di-tert-butyl benzene) fluorophosphite, 2g of slipping agent N, N' -ethylidene distearamide, 2g of opening agent SYXQ1042.25g, 15g of nucleating agent Dupont Surlyn8920 resin and 50g of polycaprolactone are mixed, and a double-screw extruder is added for melt extrusion granulation at 180 ℃ to prepare a blown film material;

2) and (3) blowing the film blowing material on a film blowing machine, wherein the temperature of a neck ring die is 190 ℃, and the blowing-up ratio is 2.5:1, so that a film with the thickness of 10 mu m is obtained.

The obtained film was subjected to a performance test, and the optical properties, thermal properties and barrier properties thereof were measured as shown in table 1, and the mechanical properties thereof were shown in table 2.

Example 5

(1) Terpolymer microspheres polymeric microspheres SYXQ104 prepared in example 4 were taken.

(2) Preparation of degradable copolyester 105:

2) 500g of the long-chain branched aliphatic aromatic copolyester prepared in the step 1) and 0.5g of dibenzoyl peroxide are subjected to extrusion reaction at 160 ℃ in an extruder to prepare the copolyester, and the melt index of the prepared copolyester is 1.5g/10min at 190 ℃ under the load of 2.16 kg;

(3) preparation of blown film 105

Mixing 105500 g of copolyester, 10101 g of antioxidant, 6181g of antioxidant, 2.25g of slipping agent erucamide, SYXQ 1053 g as an opening agent and 10g of Elvaloy4170 resin, adding 50g of succinic acid diester into a double-screw extruder, and performing melt extrusion granulation at 160 ℃ to prepare a film blowing material;

(4) and (3) blowing the film blowing material on a film blowing machine, wherein the temperature of a neck ring die is 185 ℃, and the blowing ratio is 2:1, so that the film with the thickness of 10 mu m is obtained.

Example 6

(1) Preparation of ternary copolymer microsphere SYXQ 106:

9.6g of maleic anhydride, 0.69g of azobisisobutyronitrile, 4.72g of alpha-methylstyrene, 6.24g of styrene and 86.8g of isoamyl acetate are added into a 500mL three-neck flask, after the materials are uniformly mixed, nitrogen is introduced for 20 minutes, the three-neck flask is moved into a 75 ℃ water bath for reaction for 3 hours, after the reaction is finished, the obtained polymer emulsion suspension is centrifugally separated for 20 minutes by a centrifuge at the rotating speed of 2000rad/min to obtain polymer solid A616.65g, and the content of the maleic anhydride in the polymer is 51 percent corresponding to the polymer yield of 75 percent. The particle size of the polymer microsphere is 1400 nanometers. Wherein the molar ratio of styrene to alpha-methylstyrene is 6: 4.

The polymer microspheres a6 were subjected to 1H NMR measurement, and it was found that the molar content of the maleic anhydride structural unit was 51%, the molar content of the styrene structural unit was 27% and the molar content of the α -methylstyrene structural unit was 22%, based on the total molar amount of the respective structural units in the polymer.

(2) Preparation of degradable copolyester 106:

1) preparation of long-chain branched aliphatic aromatic copolyester: under the action of a catalyst, 423.8g (2.55mol) of monomer a terephthalic acid (PTA), 650g (7.21mol) of monomer b 1, 4-Butanediol (BDO), 330g (2.79mol) of monomer c Succinic Acid (SA) and 1g (0.01mol) of monomer d glycerol are mixed for esterification reaction, and the melt index of the prepared long-chain branched aliphatic aromatic copolyester is 25g/10min at 190 ℃ under the load of 2.16 kg; the catalyst contained 0.245g of tetrabutyltitanate (available from Beijing Chemicals), 0.31g of lanthanum stearate, 0.1g of dibutyltin oxide (available from Beijing chemical three factories), 0.14g of triphenylhydroxytin (available from Beijing Chemicals);

2) 500g of the long-chain branched aliphatic aromatic copolyester prepared in the step 1) and 2.5g of dibenzoyl peroxide are subjected to extrusion reaction at 170 ℃ in an extruder to prepare the copolyester, and the melt index of the prepared copolyester is 1.8g/10min at 190 ℃ under the load of 2.16 kg;

(3) preparation of blown film 106:

mixing 500g of copolyester obtained in the step 2) with 31141.5g of antioxidant, 3g of 2, 2' -ethylidene bis (4, 6-di-tert-butyl benzene) fluorophosphite, 1g of slipping agent of ammonium stearate, SYXQ 1061 g, 5g of Elvaloy4170 resin and 25g of polycaprolactone PCL, adding into a double-screw extruder, and carrying out melt extrusion granulation at 170 ℃ to obtain a blown film material;

and (3) blowing the film blowing material on a film blowing machine, wherein the temperature of a neck ring mold is 175 ℃, and the blowing-up ratio is 2.5:1, so that a film with the thickness of 10 mu m is obtained.

Comparative example 1

This comparative example is illustrative of a reference degradable copolyester feedstock, terpolymer pellets and blown film.

The degradable copolyester raw material is the same as that in example 101, but the chain extension modification in step 2) is not carried out, so that copolyester 107 is obtained. The terpolymer pellets were SYXQ 101.

Blown film was prepared as in example 101:

the film bubble is broken through a plurality of blow molding attempts, and the film cannot be formed.

Comparative example 2

The procedure of example 1 was repeated, except that the opening agent was talc powder and the particle size distribution was 2 to 5 μm.

Comparative example 3

The same procedure as in example 1 was followed, except that the degradable copolyester was changed to a commercially available PBAT (poly (adipic acid/butylene terephthalate)).

TABLE 1

	Density/g.cm^-3	Transmittance (a)	Haze/%	Melting Point/. degree.C	Smell(s)
						Example 1	1.25	89	13	127	○
Example 2	1.25	92	14	126	○
						Example 3	1.24	89	12	122	○
Example 4	1.25	90	15	124	○
						Example 5	1.24	89	13	127	×
Example 6	1.25	91	16	128	×
						Comparative example 1	1.24	-	-	-	○
Comparative example 2	1.25	82	40	126	○
						Comparative example 3	1.25	87	41	125	○

Note: the smell is good: o; and (3) having an odor: is prepared from

TABLE 2

Dense and uniform cells, sparse and uneven cells

As can be seen from the data in tables 1 and 2, when the terpolymer microspheres provided by the invention are added into degradable copolyester for film blowing, the prepared film has excellent opening performance and better mechanical properties.

As can be seen from table 1, examples 1 to 6 have better light transmittance and haze, and lower opening force and water permeability than comparative example 2. In example 4, polycaprolactone is added, so that the composite material has better mechanical properties. PBST that is not chain extended has poor melt strength and cannot be blown to produce films. Examples 5 and 6 used conventional dibenzoyl peroxide, which had a strong odor and had low mechanical properties despite the addition of PCL and PBS.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An easy-opening controllable biodegradable film material comprises the following components in parts by weight:

100 parts of degradable copolyester;

0.05-5 parts of an opening agent, preferably 0.1-1.5 parts;

the degradable copolyester is aliphatic aromatic copolyester;

the opening agent is terpolymer microspheres.

2. The easy-opening controllable biodegradable blown film material according to claim 1, wherein:

the melt index of the degradable copolyester at 190 ℃ under the load of 2.16kg is 0.1-10g/10 min.

3. The easy opening controlled biodegradable blown film material according to claim 2, characterized in that:

the degradable copolyester is obtained by reacting components including a monomer a, a monomer b, a monomer c and a monomer d;

wherein the content of the first and second substances,

the monomer a is aromatic dibasic acid and/or ester derivatives thereof, preferably terephthalic acid and/or dimethyl terephthalate;

the monomer b is at least one of aliphatic diol of C2-C10 or alicyclic diol of C3-C10, and 1, 3-propylene glycol and/or 1, 4-butylene glycol are preferred;

the monomer C is C4-C20 aliphatic dibasic acid and/or ester derivatives thereof, preferably at least one of succinic acid, dimethyl succinate, adipic acid or dimethyl adipate;

the monomer d is at least one of polyalcohol with the functionality of more than 2, polycarboxylic acid with the functionality of more than 2 or anhydride with the functionality of more than 2, and is preferably at least one of pyromellitic dianhydride, glycerol or pentaerythritol.

4. The easy opening controlled biodegradable blown film material according to claim 3, characterized in that:

the dosage of the monomer a, the monomer b, the monomer c and the monomer d is as follows:

the molar ratio of a to c is (0-60): 100-40.

5. The easy opening controlled biodegradable blown film material according to claim 1, characterized in that:

the average particle size of the terpolymer microspheres is 500-1600 nm, preferably 800-1600 nm;

the terpolymer microsphere comprises a copolymer structure of a structural unit A, a structural unit B and a structural unit C; wherein the structural unit A is provided by maleic anhydride; the structural unit B is provided by styrene; the structural unit C is provided by alpha-methyl styrene;

the molar content of the structural unit A is 48-51%, preferably 49-50% based on the total molar weight of the terpolymer microsphere being 100% by mole; the molar content of the structural unit B is 10-45%, preferably 15-45%; the molar content of the structural unit C is 10-45%, and preferably 10-40%.

6. The easy opening controlled biodegradable blown film material according to claim 1, characterized by comprising a slip agent; wherein, based on 100 weight portions of the degradable copolyester,

the slipping agent is selected from stearate and/or organic carboxylic acid amide, wherein the stearate is selected from calcium stearate, and the organic carboxylic acid amide is selected from at least one of erucamide, oleamide, stearic acid stearamide and N, N '-ethylene bisstearamide, preferably N, N' -ethylene bisstearamide.

7. The easy opening controlled biodegradable blown film material according to claim 1, characterized by comprising a nucleating agent; wherein, based on 100 weight portions of the degradable copolyester,

the nucleating agent accounts for 0.1-20 parts by weight, preferably 0.5-5 parts by weight;

the nucleating agent is selected from at least one of hyperbranched polyamide, low-density polyethylene, ethylene-methacrylic acid ionomer or ethylene-butyl acrylate-glycidyl methacrylate terpolymer.

8. The easy opening controllable biodegradable blown film material according to claim 1, characterized by comprising a degradable resin; wherein, based on 100 weight portions of the degradable copolyester,

the weight of the degradable resin is 2-20 parts, preferably 4-12 parts; and/or the presence of a gas in the gas,

the degradable resin is selected from at least one of polycaprolactone, succinic acid butylene ester, polyglycolic acid, polylactic acid, Polyhydroxyalkanoate (PHA) and polymethyl ethylene carbonate (PPC).

9. The easy opening controlled biodegradable blown film material according to claim 1, characterized by comprising an antioxidant; wherein, based on 100 weight portions of the degradable copolyester,

the weight of the antioxidant is 0.05-5 parts, preferably 0.05-2 parts;

the antioxidant is a hindered phenol antioxidant and a phosphite ester antioxidant which are mixed according to the mass ratio of 1: 3-3: 1; wherein the hindered phenol antioxidant is at least one selected from pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 1,3, 5-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) isocyanuric acid or 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-tert-butyl-4-hydroxybenzyl) benzene; the phosphite antioxidant is at least one selected from tris [2, 4-di-tert-butylphenyl ] phosphite, pentaerythritol distearyl diphosphite or 2, 2' -ethylidene bis (4, 6-di-tert-butylphenyl) fluorophosphite.

10. The method for preparing the easily openable biodegradable blown film material according to any one of claims 1 to 9, comprising the steps of:

mixing the components including the degradable copolyester and the opening agent, and then extruding and granulating to prepare the biodegradable blown film material with controllable opening; preferably, in the extrusion granulation step, the processing temperature is 150-.

11. The method for preparing the easy-opening controllable biodegradable blown film material according to claim 10, wherein the method comprises the following steps:

the preparation method of the degradable copolyester comprises the following steps:

the degradable copolyester is obtained by reacting components including a monomer a, a monomer b, a monomer c and a monomer d under the action of a catalyst and then carrying out extrusion reaction with organic peroxide;

preferably, the first and second electrodes are formed of a metal,

preferably, the monomer a is an aromatic dibasic acid or an ester derivative thereof; the monomer b is C₂-C₁₀Aliphatic diols or C₃-C₁₀One or more of cycloaliphatic diols; the monomer C is C₄-C₂₀An aliphatic dibasic acid or an ester derivative thereof; the monomer d is one or more of polyol with the functionality of more than 2, polycarboxylic acid with the functionality of more than 2 or anhydride with the functionality of more than 2;

preferably, the monomers are used in the following amounts: the molar ratio of (a + c): b is 1: 0.8-3, (a + c): d is 100-: (100-40);

12. The method for preparing the easy opening controllable biodegradable blown film material according to claim 11, wherein:

the first catalyst is selected from the oxides of M, M (OR)₁) n and M (OOCR)₂) M, where M is titanium, antimony or zinc, n and M are each independently of the other the valence of M, R₁Is C₁-C₁₀Alkyl of R₂Is C₁-C₂₀Alkyl groups of (a); preferably, said first stepA catalyst is selected from at least one of alkoxy titanium, antimony acetate, zinc oxide, antimony oxide and titanium oxide; more preferably, the first catalyst is selected from tetrabutyl titanate (Ti (OC)₄H₉)₄) At least one of titanium isopropoxide, titanium dioxide, antimony trioxide, antimony acetate and zinc acetate;

and/or the presence of a gas in the gas,

the second catalyst is RE (R)₃)₃Wherein RE is a rare earth metal element, R₃Selected from the group consisting of halogen, alkoxy, aryloxy, acetylacetonate and R₄At least one of COO-groups, R₄Is C₁～C₃₀Alkyl groups of (a); preferably, RE is selected from at least one of lanthanum, cerium, praseodymium, neodymium, terbium, ytterbium, dysprosium, samarium or scandium; the halogen is chlorine or bromine, and the alkoxy is C₃～C₆An aryloxy group being an aryloxy group comprising at least one benzene ring and/or naphthalene ring, R₄Is C₁～C₂₀Alkyl groups of (a);

more preferably, RE is selected from lanthanum, cerium, praseodymium, neodymium or scandium, the halogen is chlorine or bromine, the alkyl in the alkoxy is at least one of isopropyl, n-butyl or isoamyl, the aryl in the aryloxy is at least one of 2, 6-di-tert-butyl-4-methylphenyl or 4-butylphenyl, and R is₄Is C₃-C₁₈At least one of alkyl groups of (a); more preferably, the second catalyst is at least one of lanthanum acetylacetonate, neodymium isopropoxide, lanthanum isopropoxide, scandium isopropoxide, lanthanum stearate, neodymium stearate, lanthanum chloride, tris (2, 6-di-tert-butyl-4-methylphenoxy) lanthanum, and a hydrate thereof;

and/or the presence of a gas in the gas,

the third catalyst is at least one organic tin compound; preferably, the third catalyst is selected from at least one of dibutyl tin oxide, methylphenyl tin oxide, tetraethyl tin, hexaethyl tin oxide, hexacyclohexyl tin oxide, didodecyl tin oxide, triethyl hydroxyl tin, triphenyl hydroxyl tin, triisobutyl tin acetate, dibutyltin diacetate, diphenyltin dilaurate, monobutyl tin trichloride, tributyl tin chloride, dibutyl tin sulfide, butyl hydroxyl tin oxide, methyl stannic acid, ethyl stannic acid, and butyl stannic acid; further preferably, the third catalyst is selected from the group consisting of a mixture of at least two of dibutyl tin oxide, tetraethyl tin, triphenyl hydroxyl tin, dibutyl tin diacetate, diphenyl tin dilaurate, monobutyl tin trichloride, tributyl tin chloride, dibutyl tin sulfide, butyl hydroxyl tin oxide, methyl stannoic acid, ethyl stannoic acid, and butyl stannoic acid; when two components are selected, the content of each component of the third catalyst may be 10 to 90 mol%, preferably 30 to 70 mol%, based on the total molar amount of the third catalyst being 100% by mole of the agent;

preferably, the first and second electrodes are formed of a metal,

the molar ratio of the total amount of the catalyst to the monomers (a + c) is 1: 1000-20000; and/or the presence of a gas in the gas,

the molar ratio of the first catalyst to the second catalyst to the third catalyst is (0.1-20): 0.1-10): 1.

13. The method for preparing the easy opening controllable biodegradable blown film material according to claim 11, wherein:

the dosage of the organic peroxide is 0.01-5 wt% of the dosage of the long-chain branched aliphatic aromatic copolyester, and preferably 0.01-1 wt%;

the organic peroxide is selected from organic peroxides with half-life of 0.2-10 min, preferably 0.2-2 min within the processing temperature range;

further preferably, the organic peroxide is selected from at least one of alkyl peroxide, acyl peroxide and peroxyester; preferably, the organic peroxide is selected from at least one of 2, 5-bis (t-amylperoxy) -2, 5-dimethylhexane, 2, 5-bis (t-butylperoxy) -2, 5-dimethylhexane, 3, 6-bis (t-butylperoxy) -3, 6-dimethyloctane, 2, 7-bis (t-butylperoxy) -2, 7-dimethyloctane, 8, 11-bis (t-butylperoxy) -8, 11-dimethyloctadecane or a mixture thereof, bis (alkylperoxy) benzene, bis (alkylperoxy) alkyne;

wherein the bis (alkylperoxy) benzene is selected from the group consisting of α, α '- (t-amylperoxy-isopropyl) benzene, α' -bis (t-butylperoxy-isopropyl) benzene, or mixtures thereof;

the bis (alkylperoxy) alkyne is selected from the group consisting of 2, 7-dimethyl-2, 7-di (t-butylperoxy) -octadiyne-3, 5,2, 7-dimethyl-2, 7-di (peroxyethyl carbonate) -octadiyne-3, 5,3, 6-dimethyl-3, 6-di (peroxyethyl carbonate) octyne-4, 3, 6-dimethyl-3, 6-di (t-butyl-peroxy) octyne-4, 2, 5-dimethyl-2, 5-di (peroxy-n-propyl-carbonate) hexyne-3, 2, 5-dimethyl-2, 5-di (peroxy-isobutyl carbonate) hexyne-3, 2, 5-dimethyl-2, at least one of 5-bis (peroxyethyl monocarbonate) hexyne-3, 2, 5-dimethyl-2, 5-bis ((alpha-cumylperoxy) hexyne-3, 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexyne-3.

14. The method for preparing the easy opening controllable biodegradable blown film material according to claim 11, wherein:

in the step 1), the step (A) is carried out,

the esterification reaction temperature is 150-220 ℃;

the copolycondensation reaction conditions include: the temperature is 250-270 ℃, and the time is 2-3 hours;

and/or the presence of a gas in the gas,

the melt index of the long-chain branched aliphatic aromatic copolyester prepared in the step 1) is 5-100g/10min at 190 ℃ under the load of 2.16 kg;

and/or the presence of a gas in the gas,

in the step 2), the extrusion temperature is 150-200 ℃, and preferably 160-180 ℃.

15. The method for preparing the easy-opening controllable biodegradable blown film material according to claim 10, wherein the method comprises the following steps:

also comprises an antioxidant;

mixing and granulating the aliphatic aromatic copolyester and the antioxidant to obtain base resin, mixing the base resin with the components including the opening agent, and extruding and granulating.

16. The method for preparing the easy-opening controllable biodegradable blown film material according to claim 10, wherein the method comprises the following steps:

the preparation method of the opening agent comprises the following steps:

wherein the polymerized monomers comprise maleic anhydride, styrene, and alpha-methylstyrene;

the molar content of maleic anhydride is 48 to 51%, preferably 49 to 50%, based on the total mass of the polymerized monomers;

the molar ratio of the styrene to the alpha-methyl styrene is 9:1-1:9, preferably 6:1-1: 6;

preferably, the amount of the polymerized monomer is 4 to 22 wt%, preferably 15 to 22 wt% of the total weight of the homogeneous solution.

17. The method for preparing the easy opening controllable biodegradable blown film material according to claim 16, wherein:

the reaction medium is organic acid alkyl ester, preferably the organic acid alkyl ester has a general formula of R₁COOR₂Wherein R is₁Selected from H, C_1-4At least one of alkyl, phenyl and benzyl of (A), R₂Is C_1-10Alkyl groups of (a); more preferably, R₁Is C_1-4Alkyl and/or phenyl of R₂Is C_1-7Alkyl groups of (a);

more preferably still, the first and second liquid crystal compositions are,

the reaction medium is selected from at least one of ethyl formate, propyl formate, isobutyl formate, pentyl formate, ethyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, isoamyl acetate, benzyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, isoamyl butyrate, ethyl isovalerate, isoamyl isovalerate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate and ethyl phenylacetate.

18. The method for preparing the easy opening controllable biodegradable blown film material according to claim 16, wherein:

the dosage of the initiator is 0.4-4 wt% of the total weight of the homogeneous solution;

the initiator is organic peroxide and/or azo compound; the organic peroxide is at least one selected from dibenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate;

the azo compound is selected from azobisisobutyronitrile and/or azobisisoheptonitrile.

19. The method for preparing the easy opening controllable biodegradable blown film material according to claim 16, wherein:

the polymerization conditions include: the polymerization temperature is 60-95 ℃, preferably 65-76 ℃; the polymerization time is 2-24 h, preferably 4-8 h.

20. The easy opening controlled biodegradable blown film material according to any of the claims 1 to 9 or a film prepared from the material prepared by the process according to any of the claims 10 to 19, characterized in that:

the thickness of the film is 5-100 μm, preferably 10-20 μm;

and/or the presence of a gas in the gas,

the tensile breaking stress of the film is greater than 18MPa, preferably greater than 25 MPa;

and/or the presence of a gas in the gas,

the light transmittance of the film is more than 89%.

21. The method for producing a film according to claim 20, wherein:

carrying out blow molding on the easy-opening controllable biodegradable blow molding film material to form a film;

preferably, the first and second electrodes are formed of a metal,

the film blowing temperature is 150-210 ℃, and is preferably 175-195 ℃; and/or the presence of a gas in the gas,

in the blow molding film forming process, the blow-up ratio is 1.5-3, preferably 2-2.5.

22. The use of the film of claim 20 in mulch films for agriculture, packaging bag films.