CN114058158B

CN114058158B - Aliphatic aromatic copolyester foaming composition, aliphatic aromatic copolyester foaming sheet and preparation method thereof

Info

Publication number: CN114058158B
Application number: CN202010753275.8A
Authority: CN
Inventors: 徐耀辉; 郭鹏; 吕明福; 祝桂香; 张师军; 高达利; 韩翎; 张伟; 白弈青
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: 2020-07-30
Filing date: 2020-07-30
Publication date: 2023-08-15
Anticipated expiration: 2040-07-30
Also published as: CN114058158A

Abstract

The invention relates to the field of foaming materials, and discloses a fatty aromatic copolyester foaming composition, a fatty aromatic copolyester foaming sheet material and a preparation method thereof. The composition comprises modified aliphatic aromatic copolyester, a cell nucleating agent and an antioxidant; the cell nucleating agent is maleic anhydride-styrene-alpha-methyl styrene copolymer microsphere, and the particle size of the cell nucleating agent is 500-1600nm; the melt index of the modified aliphatic aromatic copolyester is 0.1-5g/10min at 190 ℃ under the load of 2.16 kg; the amount of the cell nucleating agent is 0.01 to 10 parts by weight and the amount of the antioxidant is 0.01 to 3 parts by weight based on 100 parts by weight of the aliphatic aromatic copolyester. The foaming sheet and the sheet prepared from the aliphatic aromatic copolyester foaming composition meet the environmental protection requirements, and have the advantages of controllable degradation, compact foam cells, easy slicing, excellent mechanical property, simple process, large multiplying power adjustable range, good heat preservation performance, low production cost and suitability for large-scale production.

Description

Aliphatic aromatic copolyester foaming composition, aliphatic aromatic copolyester foaming sheet and preparation method thereof

Technical Field

The invention relates to the field of foaming materials, in particular to a fatty aromatic copolyester foaming composition, a fatty aromatic copolyester foaming sheet material and a preparation method thereof.

Background

The plastic product has the advantages of strong stability, light weight, low production cost and the like, thereby being popular with people. The plastic industry has been rapidly developing in recent decades, 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 the general-purpose plastic (PE, PS, PVC, etc.) itself, it remains stable in the environment for a long time after being abandoned, causing accumulation of a large amount of plastic waste in the environment, causing serious damage 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 disposal of plastic waste has become a focus of widespread attention in the international society. The prior methods for solving the problem mainly comprise an incineration method, a landfill method, recycling and the like. The above methods are still common methods for disposing plastic waste in many countries, and with the increasing prominence of the respective problems, the above methods have failed to meet the requirements of human beings on environmental protection. Fundamentally solves the pollution problem of plastic wastes, seeks a new problem solving way, and is hopefully realized by human beings. After the degradable plastic is abandoned, certain factors in the environment can be utilized to degrade, 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. Thus, the development of degradable plastics has become the final approach to solving the problem of plastic waste pollution. Conventionally, a base resin of a foam material is generally a general-purpose resin such as polypropylene or polystyrene, and is used in many fields because of its excellent light weight, heat insulation and cushioning properties. However, the foam prepared from the polymer material cannot be automatically degraded after the use period is finished, and is easy to pollute soil, rivers and oceans. Degradable foam materials have gained attention in industry and academia in recent years. Poly (butylene succinate-butylene terephthalate) (PBST) is a biodegradable high molecular compound, and can be biodegraded in a natural environment by a bacterial fermentation mode. By regulating and controlling the molecular weight of poly (butylene succinate-butylene terephthalate), the poly (butylene succinate-butylene terephthalate) can be ensured not to be degraded in the use process, and has a certain melt strength to meet the requirement of stretching the pore wall in the foaming process without cracking.

The high-rate (more than or equal to 2 times) foaming molding of the polymer at present mainly comprises three methods of a kettle-pressure foaming secondary molding method, an extrusion foaming method and a compression molding foaming method. The autoclave pressure process is to impregnate polymer microparticles with foaming agent inside autoclave to prepare foamed polymer particles of 2-4mm size through fast pressure relief foaming and to form twice in mold. However, due to the limitation of the secondary molding die, the foaming beads are difficult to prepare a large-area plate, and the plate is easy to break from the place where the beads are molded and adhered during cutting, so that a qualified sheet cannot be obtained.

The extrusion foaming method is to put polymer particles into an extruder, and if necessary, melt-knead the polymer particles with carbon dioxide, a hydrocarbon, a chemical foaming agent or a crosslinking agent under heating and pressure, and then extrude the polymer particles for foaming. However, the polymer foaming plate obtained by using carbon dioxide as a foaming agent has large cell diameter (about 500 mu m), high aperture ratio (more than or equal to 50%), poor mechanical property and brittle material which can not be cut into sheets; the foaming ratio of the obtained polymer foaming plate using the chemical foaming agent is low (about 5 times), the weight reduction is not obvious, the shape of the foam cells is not uniform, and the polymer foaming plate is not easy to cut.

The mould pressing foaming method is to put the polymer board into a mould press, introduce foaming agents such as carbon dioxide, raise the temperature and pressure to make the foaming agents impregnated in the board to saturate, then quickly release pressure and cool to prepare the polymer foaming board. Which can be processed using a conventional hot press. Simple process equipment, mild condition, low equipment requirement and low production cost. The foaming process has the advantages that after the mother board is extruded and molded, the supercritical fluid foaming agent is fully immersed in a die, and the die is rapidly released and opened for one-step molding to manufacture the foaming board with large surface area, wherein the amplitude of the foaming board can reach 2400mm or 1200mm. The foaming ratio is wide, and 5 to 35 times of foaming materials can be obtained by adjusting the process conditions, so that different application requirements are met. The mould pressing foaming method is characterized in that the foaming agent is fully saturated and impregnated in the production process, so that the foaming agent is uniformly dispersed in the polymer resin, and can be used as heterogeneous nucleation points of a plurality of bubbles in pressure relief foaming, so that the cells tend to grow rapidly and massively, and the cells are not combined and become large. Therefore, the mould pressing foaming polymer material has a uniform and fine cell structure with the diameter below 50 mu m, can be called as a microporous material, and brings more excellent mechanical property, heat preservation property and processing property to the foaming material. Because the foamed sheet is formed at one time, the foam holes are uniform and fine and are very easy to cut, and the foamed sheet with the minimum thickness of 0.3mm and the tolerance of 0.01 can be obtained by using a universal complete tool, so that the foamed sheet is the most ideal processing mode of the current foamed polymer sheet.

To prepare molded foamed polymeric materials, it is often necessary to add a cell nucleating agent to increase the foam efficiency, cell density, and to cause heterogeneous nucleation during foaming. The generation efficiency of bubbles in heterogeneous nucleation depends on the type, shape, interfacial tension of solid-gas and solid-melt, etc. of the nucleating agent, and in addition, to obtain a foam having a large cell density and a small cell size, the nucleating agent is well dispersed in the polymer to avoid occurrence of agglomeration. The activation energy required for heterogeneous nucleation is lower with the same pressure drop, and nucleation sites can easily generate bubbles several orders of magnitude more than homogeneous nucleation. The nucleating agent commonly used is an inorganic powder comprising zinc borate, silica, talc, calcium carbonate, borax or aluminum hydroxide. However, the inorganic nucleating agent has poor compatibility with the polymer matrix, and surface modification is required to prevent agglomeration and improve interface bonding with the polymer matrix.

Disclosure of Invention

The invention aims to solve the problems of low cell density, difficult slicing, poor mechanical property and uncontrollable density of a fatty aromatic copolyester foamed sheet caused by poor compatibility of an inorganic nucleating agent and a polymeric matrix in the prior art, and provides a fatty aromatic copolyester foamed composition, a fatty aromatic copolyester foamed sheet and a preparation method thereof.

To achieve the above object, the present invention provides, in a first aspect, a fatty aromatic copolyester foaming composition, characterized in that the composition comprises a modified fatty aromatic copolyester and a cell nucleating agent;

the foam cell nucleating agent is maleic anhydride-styrene-alpha-methylstyrene copolymer microsphere, and the particle size of the maleic anhydride-styrene-alpha-methylstyrene copolymer microsphere is 500-1600nm;

the melt index of the modified aliphatic aromatic copolyester is 0.1-5g/10min at 190 ℃ under the load of 2.16 kg;

the cell nucleating agent is used in an amount of 0.01 to 10 parts by weight and the antioxidant is used in an amount of 0.01 to 3 parts by weight based on 100 parts by weight of the modified aliphatic aromatic copolyester.

The second aspect of the invention provides a fatty aromatic foam board, which is characterized in that the fatty aromatic copolymer ester foam board is prepared by foaming the fatty aromatic copolymer ester composition.

The third aspect of the invention provides a preparation method of an aliphatic aromatic copolyester foamed sheet, which is characterized by comprising the following steps: and (3) melting and granulating the aliphatic aromatic copolyester foaming composition to obtain aliphatic aromatic copolyester granules, extruding the granules into plates, and foaming.

The fourth aspect of the invention provides a fatty aromatic copolyester foamed sheet prepared by the preparation method.

The fifth aspect of the invention provides a fatty aromatic copolyester foamed sheet, which is characterized in that the foamed sheet is prepared from the fatty aromatic copolyester foamed sheet.

The sixth aspect of the invention provides a method for preparing the aliphatic aromatic copolyester foam sheet, which is characterized in that the foam sheet is obtained by cutting and molding the foam sheet.

Through the technical scheme, the aliphatic aromatic copolyester foaming composition, the aliphatic aromatic copolyester foaming sheet and the preparation method thereof provided by the invention have the following beneficial effects:

1) According to the aliphatic aromatic copolyester foaming composition provided by the invention, the mechanical property of the foaming composition can be obviously improved by adopting the aliphatic aromatic copolyester subjected to chain extension modification, and the foaming sheet prepared from the foaming composition can be applied to the fields of automotive interiors, medical equipment, household articles, low-temperature cold chain packaging, sports equipment, transportation tools and the like.

2) Furthermore, in the aliphatic aromatic copolyester foaming composition provided by the invention, the maleic anhydride-styrene-alpha-methyl styrene copolymer microsphere is used as a cell nucleating agent, so that the characteristics of compact cells, easiness in slicing, simple preparation process, large adjustable multiplying power range, good heat preservation performance, low production cost and suitability for large-scale production of the foaming sheet are obtained.

3) Furthermore, in the invention, the supercritical fluid is adopted as the foaming agent, and compared with the organic foaming agent used in the prior art, the invention has the advantages of environmental protection, safety and the like.

4) Furthermore, the aliphatic aromatic copolyester foaming sheet and the sheet provided by the invention have controllable degradation structures, can be used for landfill degradation of garbage, do not cause secondary pollution, and meet the requirement of recycling economy.

Drawings

FIG. 1 is a scanning electron microscope image of the internal cell morphology of the foamed sheet provided in example 1, scale bar 1mm;

FIG. 2 is a scanning electron micrograph of the internal cell morphology of the foamed sheet provided in example 1, scale 100 μm;

FIG. 3 is a scanning electron micrograph of the internal cell morphology of the foamed sheet provided in comparative example 4, scale bar 1mm;

FIG. 4 is a scanning electron micrograph of the internal cell morphology of the foamed sheet provided in comparative example 4, on a scale of 500 μm.

Detailed Description

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

The invention provides a fatty aromatic copolyester foaming composition, which is characterized by comprising fatty aromatic copolyester and a cell nucleating agent;

the cell nucleating agent is used in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the modified aliphatic aromatic copolyester.

Modified aliphatic aromatic copolyester

In the invention, the modified aliphatic aromatic copolyester is prepared by modifying aliphatic aromatic copolyester by a chain extender. The inventor researches and discovers that the melt index of the aliphatic aromatic copolyester can be regulated and controlled through chain extension modification, so that the modified aliphatic aromatic copolyester has excellent mechanical properties, meets the processing requirements, and can be used for foaming compositions to obtain foamed plates and sheets with more excellent comprehensive properties.

In the invention, the steps of chain extension modification comprise: and (3) carrying out extrusion reaction on the aliphatic aromatic copolyester and the chain extender. Preferably, the temperature of the extrusion reaction is 150-200 ℃, preferably 160-180 ℃.

According to the invention, after chain extension modification, the obtained modified aliphatic aromatic copolyester has a melt index of 0.1-5g/10min, preferably 1-3g/10min, at 190 ℃ and a load of 2.16 kg.

According to the invention, the molecular weight distribution of the modified aliphatic aromatic copolyester is 3 to 10, preferably 5 to 7.

According to the invention, the chain extender is used in an amount of 0.01 to 5 wt.%, preferably 0.2 to 2 wt.% of the aliphatic aromatic copolyester.

According to the invention, the chain extender is an organic peroxide having a half-life of 0.2 to 10min, preferably 0.2 to 2min.

In the present invention, the half-life of the organic peroxide means the time required for a certain amount of peroxide to decompose to half of its initial amount at a certain temperature in the processing temperature range.

According to the present invention, the chain extender is selected from at least one of alkyl peroxides, acyl peroxides and peroxyesters.

According to the present invention, the alkyl peroxide is at least one selected from the group consisting of dicumyl peroxide, 2, 5-dimethyl-2, 5-di (t-butyl) hexane peroxide and di (t-butyl isopropyl peroxybenzene; the acyl peroxide is selected from dibenzoyl peroxide and/or lauroyl peroxide.

According to the invention, the aliphatic aromatic copolyester is obtained by copolycondensation reaction of a monomer a, a monomer b, a monomer c and a monomer d in the presence of a catalyst.

In the invention, when preparing the aliphatic aromatic copolyester, a, b, c, d monomer raw materials and a catalyst can be simultaneously added into an esterification kettle for esterification, or can be respectively esterified (a and b are esterified, c and b are esterified) and then mixed together for copolycondensation reaction.

In the present invention, the copolycondensation reaction between monomers a, b, c, d can be achieved using copolycondensation reaction conditions conventional in the art.

According to the invention, the monomer a is selected from aromatic dibasic acids or ester derivatives thereof; the monomer b is selected from C ₂ -C ₁₀ One or more of aliphatic diols or alicyclic diols; the monomer C is selected from C ₄ -C ₂₀ An aliphatic dibasic acid or an ester derivative thereof; the monomer d is selected from one or more of polyols, polycarboxylic acids or anhydrides with functionality greater than 2.

According to the invention, the monomer a is selected from terephthalic acid and/or dimethyl terephthalate; the monomer b is selected from 1, 3-propanediol and/or 1, 4-butanediol; the monomer c is at least one selected from succinic acid, dimethyl succinate, adipic acid and dimethyl adipate; the monomer d is at least one selected from pyromellitic dianhydride, glycerol and pentaerythritol.

According to the invention, the molar ratios of monomer a, monomer b, monomer c and monomer d satisfy the following conditions: (a+c): b is 1:0.8-3; (a+c): d is 100-2000:1, and a:c is 60:40-0:100.

According to the invention, the catalyst comprises a first catalyst, a second catalyst and a third catalyst.

In the present invention, the first catalyst is selected from the group consisting of an oxide of M, M (OR) ¹ ) n and M (OOCR) ² ) _m Wherein M is titanium, antimony or zinc, n and M are each independently of the other the valence of M, R ¹ Is C ₁ -C ₁₀ Alkyl of R ² Is C ₁ -C ₂₀ Alkyl of (a); the second catalyst is RE (R) ³ ) ₃ Wherein RE is a rare earth metal element, R ³ Is selected from halogen, alkoxy, aryloxy, acetylacetonate and R ⁴ At least one of COO-groups, R ⁴ Is C ₁ -C ₃₀ Alkyl of (a); the third catalyst is at least one organotin compound.

According to the invention, the molar ratio of the total amount of catalyst added to monomer (a+c) is 1:1000-20000, preferably 1:3000-10000.

According to the invention, the first catalyst: and a second catalyst: the molar ratio of the third catalyst is 0.1-20:0.1-10:1, preferably 0.5-5:0.5-5:1.

In the present invention, the melt index of the aliphatic aromatic copolyester which is not subjected to chain extension modification is 8-80g/10min, preferably 25-60g/10min at 190 ℃ under a load of 2.16 kg.

Maleic anhydride-styrene-alpha-methylstyrene copolymer microsphere

In the invention, the maleic anhydride-styrene-alpha-methyl styrene copolymer microsphere is a copolymer obtained by dissolving maleic anhydride, styrene, alpha-methyl styrene and an initiator in an organic medium in the presence of inert atmosphere to form a homogeneous solution and then carrying out polymerization reaction.

In the invention, maleic anhydride, alpha-methyl styrene and styrene are copolymerized in a copolymerization mode in the presence of an organic medium according to the method defined by the invention, and the dosage of maleic anhydride and the molar ratio of styrene to alpha-methyl styrene in a polymerization monomer are regulated and controlled, so that the self-stable dispersion of a polymerization system is realized, the prepared polymer is in a microsphere shape with excellent uniformity, and no additives such as a stabilizer, a precipitant and the like are additionally added in the polymerization process, so that the obtained copolymer microsphere has the characteristic of clean surface, and has good dispersibility in the medium and no aggregation.

According to the present invention, the molar content of the structural unit provided by maleic anhydride is 48 to 51 mol% and the molar content of the structural unit provided by styrene is 10 to 45% based on the total amount of the maleic anhydride-styrene- α -methylstyrene copolymer microspheres; the molar content of the structural units provided by the alpha-methylstyrene is from 10 to 45%.

The maleic anhydride-styrene-alpha-methyl styrene copolymer microsphere provided by the invention contains more maleic anhydride structural units, so that the copolymer microsphere has stronger polarity and simultaneously maintains the performance characteristic of better compatibility with aliphatic aromatic copolyester.

According to the invention, maleic anhydride provides a molar content of structural units of 49-50% based on the total mass of the maleic anhydride-styrene-alpha-methylstyrene copolymer microspheres; the molar content of the structural units provided by styrene is 15-45%; the molar content of the structural units provided by the alpha-methylstyrene is from 10 to 40%.

In the present invention, the total mass of maleic anhydride, α -methylstyrene and styrene is 100%.

In the invention, in order to obtain copolymer microspheres with uniform particles and excellent morphology, the inventor researches the feeding ratio among maleic anhydride, alpha-methyl styrene 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.

According to the invention, the total mass concentration of maleic anhydride, styrene and alpha-methylstyrene is from 4 to 22% by weight, preferably from 6 to 19% by weight, based on the total weight of the homogeneous solution.

According to the invention, the initiator is present in a mass concentration of 0.4 to 4 wt.%, preferably 0.6 to 3.6 wt.%, more preferably 1 to 3 wt.%, based on the total weight of the homogeneous solution.

According to the invention, the initiator is selected from organic peroxides and/or azo compounds.

According to the present invention, the organic peroxide is at least one selected from dibenzoyl peroxide, dicumyl peroxide, ditert-butyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.

According to the invention, the azo compound is selected from azobisisobutyronitrile and/or azobisisoheptonitrile.

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

In the invention, the organic acid alkyl ester is selected as an organic medium, can be matched with the specific dosage of maleic anhydride, alpha-methyl styrene and styrene, and can realize the self-stabilization precipitation polymerization reaction of maleic acid, alpha-methyl styrene and styrene, and the polymerization reaction system does not need to add any stabilizer or auxiliary stabilizer, has self-stabilization dispersion effect, and the surface of the obtained copolymer microsphere is clean and pollution-free.

According to the invention, the alkyl esters of organic acids have the formula R ₁ COOR ₂ Wherein R is ₁ Selected from H, C ₁ -C ₄ At least one of alkyl, phenyl and benzyl, R ₂ Is substituted or unsubstituted C ₁ -C ₁₀ Is a hydrocarbon group.

According to the invention, R ₁ Is substituted or unsubstituted C ₁ -C ₄ Alkyl or phenyl, R ₂ Is substituted or unsubstituted C ₁ -C ₇ Is a hydrocarbon group.

According to the present invention, the organic medium is at least one selected from the group consisting of ethyl formate, propyl formate, isobutyl formate, pentyl formate, ethyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, amyl 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.

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

In the present invention, the inventors have studied the conditions of the polymerization reaction in order to achieve self-stabilization of the polymerization system and further to obtain copolymer microspheres having particle diameters which are clean and free of contamination. Researches show that when the polymerization temperature is 60-95 ℃ and the polymerization time is 2-24 hours, a stable self-stabilizing system is formed by the polymerization system, in the system, polymerized monomers of maleic anhydride, alpha-methyl styrene and styrene are polymerized to form microspheres, and the microspheres are not aggregated in a medium, so that the polymer has good dispersibility.

Further, the polymerization temperature is 65-76 ℃ and the polymerization time is 4-8h.

The process of the dispersion polymerization of the present invention is operated as follows. The monomer, the initiator and the medium are fed into a reactor with nitrogen protection, a stirrer, a condenser tube and a thermometer according to a set proportion. The monomer and initiator are completely dissolved in the medium to form a clear and transparent homogeneous solution. Nitrogen is introduced to remove oxygen from the system and then heated in a water bath (or oil bath) to effect the reaction. The whole reaction process is protected by nitrogen.

According to the present invention, the particle size of the maleic anhydride-styrene-alpha-methylstyrene copolymer microsphere is 500 to 1600nm, preferably 800 to 1600nm.

According to the present invention, the molecular weight distribution (PI) of the maleic anhydride-styrene- α -methylstyrene copolymer microspheres is 2 to 12, preferably 4 to 8.

In the invention, the particle size of the copolymer microsphere can be measured by a scanning electron microscope method.

Aliphatic aromatic copolyester foaming composition

As previously mentioned, in the present invention, the aliphatic aromatic ester foaming composition comprises an aliphatic aromatic copolyester and a cell nucleating agent; the foam cell nucleating agent is maleic anhydride-styrene-alpha-methyl styrene copolymer microsphere, and the particle size of the maleic anhydride-styrene-alpha-methyl styrene copolymer microsphere is 500-1600nm, preferably 800-1600nm; the cell nucleating agent is used in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the aliphatic aromatic copolyester. Preferably, the cell nucleating agent is used in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the aliphatic aromatic copolyester.

According to the invention, the composition further comprises an antioxidant in an amount of 0.01 to 3 parts by weight, preferably 0.1 to 0.5 parts by weight, based on 100 parts by weight of the modified aliphatic aromatic copolyester.

In the present invention, the antioxidant includes a phenolic antioxidant and/or a phosphite antioxidant, and specifically, the antioxidant may be at least one selected from pentaerythritol tetrakis [ beta- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate (antioxidant 1010), n-stearyl beta- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate (antioxidant 1076), 2' -methylenebis- (4-methyl-6-t-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, tris (2, 4-di-t-butylphenyl) phosphite, bis (2, 4-di-t-butylphenol) pentaerythritol diphosphite (antioxidant 626), and bis (2, 6-di-t-butyl-4-tolyl) pentaerythritol diphosphite.

In the invention, the antioxidant is preferably a phenolic antioxidant and a phosphite antioxidant, wherein the weight ratio of the phenolic antioxidant to the phosphite antioxidant is 0.005-2:0.002-1, preferably 0.03-0.35:0.02-0.15.

In addition, the aliphatic aromatic copolyester foaming composition can also contain any of various other existing auxiliary agents commonly used in aliphatic aromatic copolyester resins and aliphatic aromatic copolyester foaming materials, and the other auxiliary agents do not adversely affect the foaming performance, the foam cell structure and the mechanical properties of the aliphatic aromatic copolyester foaming composition, the foaming sheet and the sheet. Such other adjuvants include, but are not limited to: at least one of a slipping agent, an antistatic agent, an ultraviolet absorber, a releasing agent, a flame retardant, a metal deactivator, a pigment, a nucleating agent, a foam control agent, a filler, a stabilizer, a reinforcing agent, a lubricant, and the like. In addition, the amounts of the other additives may be selected conventionally in the art, and those skilled in the art will be aware of the above, and will not be described herein.

In the invention, the main raw material of the foaming composition in the aliphatic aromatic copolymerization is adopted, and the maleic anhydride-styrene-alpha-methyl styrene copolymer microsphere is used as a cell nucleating agent, so that the foaming performance of the foaming sheet material and the foaming sheet material can be improved without modifying the foaming composition.

The invention provides a fatty aromatic copolyester foamed sheet, which is characterized by being prepared by foaming the fatty aromatic copolyester composition.

According to the invention, the expansion ratio of the volume of the foaming plate is 2-40 times, preferably 7-25 times; the average cells of the foamed sheet are 30-400 μm, preferably 75-200 μm; the cell density of the foaming plate is 1 multiplied by 10 ³ Up to 1X 10 ¹² Individual/cm ³ Preferably 1X 10 ⁴ Up to 1X 10 ¹⁰ Individual/cm ³ The method comprises the steps of carrying out a first treatment on the surface of the The compressive strength was 0.1-5MPa, preferably 0.5-4MPa.

According to the present invention, preferably, the foaming is a compression foaming method.

In the present invention, the pelletization and extrusion of the sheet material can be performed in various existing manners, and the specific operation process is well known to those skilled in the art.

According to the present invention, the compression molding foaming method comprises the steps of:

(1) Heating the foaming mould to a foaming temperature;

(2) And placing the aliphatic aromatic copolyester sheet material into a foaming mold, introducing a foaming agent, and foaming to obtain the aliphatic aromatic copolyester foamed sheet material.

According to the invention, the foaming temperature is 0.1-40 ℃ lower than the melting temperature of the aliphatic aromatic copolyester.

According to the invention, the foaming temperature is 110-150 ℃;

according to the invention, the foaming pressure is up to 8-40MPa, preferably 10-25MPa.

In the present invention, the foaming agent may be an organic-based physical foaming agent or an inorganic-based physical foaming agent. The organic physical blowing agent includes aliphatic hydrocarbons such as propane, butane, pentane, hexane and heptane, alicyclic hydrocarbons such as cyclobutane and cyclohexane, and halogenated hydrocarbons such as chlorofluoromethane, trifluoromethane, 1, 2-difluoroethane, 1, 2-tetrafluoroethane, methyl chloride, ethyl chloride and methylene chloride. Examples of inorganic physical blowing agents include air, nitrogen, carbon dioxide, oxygen, nitrogen, and water. These organic and inorganic foaming agents may be used alone or in combination of two or more. Because of the stability (uniformity), low cost and environmental friendliness issues of the apparent density of the aliphatic aromatic copolyester foamed sheet and sheet, supercritical fluids, such as supercritical carbon dioxide and/or supercritical nitrogen, are preferred as the blowing agent in the present invention. Preferably, the foaming agent is supercritical carbon dioxide and supercritical nitrogen, and the volume ratio of the supercritical carbon dioxide to the supercritical nitrogen is 0.1-99.9, preferably 50-99.9.

According to the invention, the pressure of the foaming agent is 5-30MPa, preferably 10-20MPa.

According to the invention, the foaming agent diffuses to the desired saturation time of 10-600min, preferably 30-300min.

In the invention, the foaming time of the aliphatic aromatic copolyester foaming sheet material comprises the time of heating and boosting and the time of diffusing to the required saturation time.

In the present invention, the foaming process of the aliphatic aromatic copolyester foaming composition can be achieved using a conventional compression foaming apparatus in the prior art, for example, the compression foaming apparatus comprises: the device comprises a hydraulic system for providing mold closing pressure, a temperature control system for providing heat, a high-pressure conveying system for providing supercritical fluid foaming agent, a flat plate foaming mold, a rapid pressure relief system and a gas recovery system.

In a specific implementation method of the invention, the steps of compression molding foaming are as follows:

(1) The temperature control system for providing heat heats the flat foaming mold between the molding presses to a foaming temperature;

(2) Placing the aliphatic aromatic copolyester plate into a flat foaming mold, driving the flat foaming mold to be closed by a hydraulic system, pressurizing the hydraulic system to 15-40MPa, and introducing a supercritical fluid foaming agent into the flat foaming mold by a high-pressure gas conveying system to enable the gas pressure to reach 5-30MPa, preferably 10-20 MPa;

(3) The supercritical fluid foaming agent diffuses from the surface of the material into the aliphatic aromatic copolyester plate, and the saturation time required by diffusion is 10-600min, preferably 30-300min;

(4) After the dissolution balance is achieved, the gas in the flat foaming mold is quickly released by the quick pressure release system and is recovered by the gas recovery system. And opening the die, and foaming the aliphatic aromatic copolyester material in the die to obtain the aliphatic aromatic copolyester foamed sheet with controllable foaming rate and cell structure.

In the invention, the molding press can be provided with a layer of foaming mold or a plurality of layers of foaming molds.

In the invention, the pressure relief and die opening can be performed after the supercritical fluid pressure in the die is relieved to any pressure lower than the saturation pressure through the pressure relief valve, or can be performed directly under the supercritical condition.

In the invention, the pressures refer to gauge pressure.

According to the invention, the expansion ratio of the volume of the foaming plate is 2-40 times, preferably 7-25 times; the average cells of the foamed sheet are 30-400 μm, preferably 75-200 μm; the cell density of the foaming plate is 1 multiplied by 10 ³ Up to 1X 10 ¹² Individual/cm ³ Preferably 1X 10 ⁴ Up to 1X 10 ¹⁰ Individual/cm ³ The method comprises the steps of carrying out a first treatment on the surface of the The compressive strength is 0.1-2MPa, preferably 0.25-1MPa.

According to the present invention, the thickness of the foamed sheet is 0.3mm or more, preferably 0.5mm or more; the thickness tolerance of the foamed sheet is 0.01 to 0.05, preferably 0.02 to 0.04.

According to the present invention, the cutting molding can be performed in various existing foaming plastic cutting molding machines, and the conditions of the cutting molding of the plastic sheet can be selected conventionally in the art, and those skilled in the art can know the conditions, and the details are not repeated here.

The aliphatic aromatic copolyester foamed sheet and the sheet provided by the invention have the advantages of biological controllable degradation, compact cells, easiness in slicing and the like, and can be applied to occasions with high requirements on light weight, energy absorption and biological degradation of plastic products, such as food packaging, household sports products and the like.

The present invention will be described in detail by examples. In the following examples of the present invention,

(1) Density tester: CPA225D, density accessory YDK01, sartorius company, germany. The testing method comprises the following steps: the apparent density of the PBST chain-extended modified foaming material is obtained by using a drainage method according to the GB/T6343-2009 standard test by using a density accessory of a Satorius balance. The foaming ratio of the obtained PBST chain extension modified foaming material is calculated by a formula, wherein b=ρ1/ρ2, b is the foaming ratio, ρ1 is the density of the polypropylene base resin, and ρ2 is the apparent density of the foaming material.

(2) Scanning electron microscope: XL-30, FEI company, USA. The testing method comprises the following steps: the foaming material is quenched by liquid nitrogen, the section is sprayed with metal, the cell structure inside the foaming material is inspected by adopting a Scanning Electron Microscope (SEM), the cell size is measured by adopting Image Pro Plus software, and the cell density is calculated. The formula is N0= [ nM2/A ]3/2 phi

Wherein: n is the number of cells in the SEM, M is the magnification, A is the area (in cm) of the selected region on the SEM ² ) Phi is the expansion ratio of the foaming material.

(3) Open-close aperture ratio tester: ULTRAFOAM 1200e, quantachrome instruments, inc., U.S.A.. The testing method comprises the following steps: according to GB/T10799-2008.

(4) Compression strength test of foamed sheet: A50X 50mm sample was cut from the foamed sheet, and a compression strength test was performed based on GBT8813-2008 "test method for compression Strength of rigid foam", and a compression test was performed with a compression speed of 10mm/min, to obtain a compression strength at which the molded article was compressed by 50%.

(5) Melt Index (MI): the measurement was carried out according to the method specified in GB/T3682-2000, wherein the test temperature was 190℃and the load was 2.16kg;

(6) Determination of PBST resin density: the measurement was performed according to the method specified in GB/T1033.2-2010 and using a density gradient column method.

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

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

The raw materials used in examples and comparative examples were all commercially available.

Example 1

This example is for illustrating the PBST chain-extended modified product, the foamed sheet and the foamed sheet provided by the invention.

The PBST composition provided in this example contains the PBST chain extension modifier, the cell nucleating agent and the processing aid provided in the invention.

In the presence of a catalyst, a copolyester PBST1 was prepared starting from 423.8g of terephthalic acid (PTA), 330g of Succinic Acid (SA), 650g of 1, 4-Butanediol (BDO) and 1g of glycerol, and having a melt index of 44.9g/10min at 190℃and a load of 2.16 kg. Wherein the catalyst contains 0.322g of ethylene glycol antimony, 0.43g of lanthanum chloride and 0.14g of triphenylhydroxy tin.

500g of PBST1 and 2.5g of dibenzoyl peroxide are extruded at 160 ℃ in an extruder to prepare copolyester PBST2, wherein the melt index of the copolyester PBST2 at 190 ℃ and a load of 2.16kg is 1.7g/10min, and the molecular weight distribution is 5.95.

The cell nucleating agent is ternary polymerization microsphere 101, which is called SYXQ101 herein;

antioxidant 1010 (BASF corporation), antioxidant 168 (BASF corporation).

(1) Preparation of SYXQ 101:

11g of maleic anhydride, 0.6g of azobisisobutyronitrile, 10.62g of alpha-methylstyrene, 1.04g of styrene and 87.8g 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 water bath at 60 ℃ for reaction for 5 hours, after the reaction is completed, the obtained polymer emulsion suspension is centrifugally separated for 20 minutes by a centrifugal machine at a rotating speed of 2000rad/min, so that 11.04g of polymer solid A1 is obtained, and the corresponding polymer yield is 51.4%. The particle size of the polymer microsphere was 1200 nm and the molecular weight distribution of the copolymer was 5.2.

The polymer microsphere A1 was subjected to 1H NMR measurement to determine that the molar content of the maleic anhydride structural unit was 50%, the molar content of the styrene structural unit was 10%, the molar content of the α -methylstyrene structural unit was 40% based on the total molar amount of each structural unit in the polymer, and the molecular weight distribution was 4.36.

(2) Preparation of PBST composition 101:

PBST2 and SYXQ101 are weighed and mixed according to a proportion, wherein the weight of the PBST2 is 100 parts, the weight of the SYXQ101 is 0.5 part, and the weight of the antioxidant 1010 and the weight of the antioxidant 168 are 0.2 part and 0.1 part respectively. And then adding the mixture into a high-speed stirrer to mix uniformly, adding the mixed material into a feeder of a double-screw extruder manufactured by W & P company, feeding the material into a double-screw through the feeder, keeping the temperature of the screw at 185 ℃ in the processing process, melting and mixing uniformly through the screw, extruding, granulating and drying to obtain PBST composition granules 101. The melt index MI=1.5 g/10min was examined.

(3) Preparation of PBST foaming plate:

the PBST composition pellets 101 obtained in the step (2) were dried, kneaded by a twin screw extruder, molded by a die, and cooled and cut off to prepare 720mm x 360mm x 30mm PBST plates to be foamed. And heating the die arranged between the die presses to 120 ℃, putting the PBST plate into the die, closing the die by the die presses, and sealing the die. Introducing 30MPa of supercritical nitrogen into the die, and allowing the supercritical nitrogen to diffuse into the PBST matrix at 120 ℃ and 30 MPa. After saturation for 60min, the diffusion balance is achieved, the pressure in the die is reduced to 12MPa through a pressure relief valve, then the die is opened, pressure is relieved, foaming is carried out, cooling and shaping are carried out, and the PBST foaming plate with the external dimension of 160 mm-795 mm-60 mm is obtained. The appearance of the plate is smooth and even in size. The foaming ratio was measured. The internal cell morphology was analyzed by scanning electron microscopy. As can be seen from FIGS. 1 and 2, the cell diameters are uniformly distributed, the size is between 40 and 100 mu m, the cell shape is regular, and the cell walls are not damaged or deformed. It was compression tested. The properties are shown in Table 1.

(4) Preparation of PBST foaming sheet:

the PBST foamed sheet of the above step (3) was cut into a sheet having a thickness of 2mm using an automatic slicer, and the tolerance thereof is shown in table 1.

Example 2

This example is for illustrating the PBAT chain extension modified product, the foamed sheet and the foamed sheet provided by the invention.

The PBAT composition provided in this example contains the PBAT chain extension modifier, the cell nucleating agent and the processing aid provided in this invention.

Copolyester PBAT1 was prepared starting from 423.8g of terephthalic acid (PTA), 466.7g of 1, 6-Adipic Acid (AA), 650g of 1, 4-Butanediol (BDO), 0.5g of pyromellitic dianhydride at 190℃and a melt index of 31.7g/10min at a load of 2.16kg in the presence of a catalyst. Wherein the catalyst contains 0.288g of tetrabutyl titanate, 0.37g of indium chloride and 0.1g of dibutyl tin oxide.

500g of PBAT1 and 5g of dicumyl peroxide are subjected to extrusion reaction at 170 ℃ in an extruder to prepare copolyester PBAT2, wherein the melt index of the copolyester PBAT2 is 1.2g/10min and the molecular weight distribution of the copolyester PBAT2 is 5.18 at 190 ℃ under a load of 2.16 kg.

Cell nucleating agent, SYXQ102

Antioxidant 1010 (BASF corporation), antioxidant 168 (BASF corporation).

(1) Preparation of SYXQ102

10g of maleic anhydride, 0.89g of azodiisobutyronitrile, 9.44g of alpha-methylstyrene, 2.08g of styrene and 87.8g of butyl butyrate 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 with the temperature of 70 ℃ for reaction for 5 hours, and after the reaction is finished, the obtained polymer emulsion suspension is centrifugally separated for 20 minutes by a centrifugal machine at the rotating speed of 2000rad/min, so that 11.72g of polymer solid A is obtained, and the corresponding polymer yield is 55.0%. The particle size of the polymer microspheres was 1500 nm. The polymer microsphere A2 was subjected to 1H NMR measurement, and the molar content of the maleic anhydride structural unit was 48%, the molar content of the styrene structural unit was 12%, the molar content of the α -methylstyrene structural unit was 40% based on the total molar amount of each structural unit in the polymer, and the molecular weight distribution was 7.4.

(2) Preparation of PBAT composition 102:

PBAT composition 102 was prepared as in example 1 except that PBAT2 was used instead of PBST2, SYXQ102 was used instead of SYXQ101, and the melt index mi=1 g/10min of the composition was examined.

(3) Preparing a PBAT foaming plate:

the preparation of the PBAT foamed sheet was the same as in example 1, except that the foaming temperature was 125 ℃. Obtain PBAT foaming plate with the external dimension of 1441mm x 721mm x 60 mm. The appearance of the plate is smooth and even in size. The foaming ratio was measured. The internal cell morphology was analyzed by scanning electron microscopy. It was compression tested. The properties are shown in Table 1.

(4) Preparation of PBAT foaming sheet:

the PBAT foamed sheet of step (3) above was cut into 1.5mm thick sheets using an automatic microtome, with the tolerances shown in table 1.

Example 3

This example is a description of the PBST composition, expanded beads and expanded bead molded articles provided by the present invention.

Copolyester PBST1 was prepared in the same manner as in example 1: the copolyester PBST1 was prepared from 423.8g of terephthalic acid (PTA), 330g of Succinic Acid (SA), 650g of 1, 4-Butanediol (BDO) and 1g of glycerol, and had a melt index of 44.9g/10min at 190℃and a load of 2.16 kg.

500g of PBST1, 2, 5-dimethyl-2, 5-di (tert-butyl) hexane peroxide and 2.5g of PBST3 were subjected to extrusion reaction at 180℃in an extruder to prepare a copolyester PBST3 having a melt index of 1.4g/10min and a molecular weight distribution of 5.8 at 190℃and a load of 2.16 kg.

The cell nucleating agent is SYXQ103;

antioxidant 1010 (BASF).

(1) Preparation of SYXQ103

10.2g of maleic anhydride, 0.7g of azodiisobutyronitrile, 8.26g of alpha-methylstyrene, 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 ℃ for reaction for 5 hours, after the reaction is finished, the obtained polymer emulsion suspension is centrifugally separated for 20 minutes by a centrifugal machine at a rotating speed of 2000rad/min, and polymer solid A3.38 g is obtained, and the corresponding polymer yield is 77.3%. The particle size of the polymer was 1600 nm. The polymer microsphere A3 was subjected to 1H NMR measurement, and the molar content of the maleic anhydride structural unit was 51%, the molar content of the styrene structural unit was 15%, the molar content of the α -methylstyrene structural unit was 34% based on the total molar amount of each structural unit in the polymer, and the molecular weight distribution was 6.7.

(2) Preparation of PBST composition 103:

PBST composition 103 was prepared as in example 1, except that PBST3 was used in place of PBST2, SYXQ103 was used in place of SYXQ101, and 0.5 part of antioxidant 1010 was used in place of 0.3 part of the complex antioxidant. The melt index mi=1.3 g/10min of the composition was examined.

(3) Preparation of PBST foaming plate:

and (3) drying the PBST composition granules prepared in the step (2), mixing by a double-screw extruder, forming by a die, cooling and cutting, and preparing the polypropylene plate to be foamed, wherein 720mm is 360mm and 30 mm. And heating the die arranged between the die presses to 118 ℃, putting the polypropylene plate into the die, closing the die by the die presses, and sealing the die. Introducing 15MPa of supercritical carbon dioxide into the die, and allowing the supercritical carbon dioxide to diffuse into the PBST matrix at 118 ℃ and 15 MPa. After saturation for 45min, the diffusion balance is achieved, the pressure in the die is reduced to 4MPa through a pressure relief valve, then the die is opened, the pressure is relieved, the foam board is ejected out, cooling and shaping are carried out, and the PBST foam board with the external dimension of 2402 mm-1201 mm-60.2 mm is obtained. The appearance of the plate is smooth and even in size. The foaming ratio was measured. The internal cell morphology was analyzed by scanning electron microscopy. It was compression tested. The properties are shown in Table 1.

(4) Preparation of PBST foaming sheet:

the PBST foamed sheet of the above step (3) was cut into a sheet having a thickness of 0.5mm using an automatic slicer, and the tolerance thereof was as shown in table 3.

Example 4

500g of PBST1 and 2.5g of di (tert-butylperoxyisopropyl) benzene were subjected to extrusion reaction at 170℃in an extruder to prepare a copolyester PBST4 having a melt index of 2.2g/10min and a molecular weight distribution of 6.9 at 190℃under a load of 2.16 kg.

The cell nucleating agent is SYXQ104;

antioxidant 1010 (BASF corporation), antioxidant 168 (BASF corporation).

(1) Preparation of SYXQ104

9.6g of maleic anhydride, 0.85g of azodiisobutyronitrile, 7.08g of alpha-methyl styrene, 4.16g of styrene and 85.8g of butyl acetate are added into a 500mL three-necked flask, after the materials are uniformly mixed, nitrogen is introduced for 20 minutes, the three-necked flask is moved into a water bath with the temperature of 65 ℃ for reaction for 5 hours, and after the reaction is finished, the obtained polymer emulsion suspension is centrifugally separated for 20 minutes by a centrifugal machine at the rotating speed of 2000rad/min, so that the polymer solid A4 is 16.63g, and the corresponding polymer yield is 79%. The particle size of the polymer microsphere was 1500 nm and the molecular weight distribution of the copolymer was 6.2.

The polymer microsphere A4 was subjected to 1H NMR measurement, and the molar content of the maleic anhydride structural unit, the molar content of the styrene structural unit and the molar content of the alpha-methylstyrene structural unit were determined to be 49%, 20%, 31% and 4.8, respectively, based on the total molar amount of the structural units in the polymer.

(2) Preparation of PBST composition 104:

PBST composition 104 was prepared as in example 1, except that PBST4 was used instead of PBST2. The melt index mi=1.8 g/10min of the composition was examined.

(3) Preparation of PBST foaming plate:

and (3) drying the PBST composition granules prepared in the step (2), mixing by a double-screw extruder, forming by a die, cooling and cutting, and preparing the PBST plate to be foamed with 720mm and 360mm and 25 mm. And heating the die arranged between the die presses to 123 ℃, putting the PBST plate into the die, closing the die by the die presses, and sealing the die. Introducing 15MPa of supercritical carbon dioxide into the die, and allowing the supercritical carbon dioxide to diffuse into the PBST matrix at 123 ℃ and 15 MPa. After saturation for 45min, the diffusion balance is achieved, the pressure in the die is reduced to 4MPa through a pressure relief valve, then the die is opened, the pressure is relieved, the foam board is ejected out, cooling and shaping are carried out, and the PBST foam board with the external dimension of 2402 mm-1201 mm-60.1 mm is obtained. The appearance of the plate is smooth and even in size. The foaming ratio was measured. The internal cell morphology was analyzed by scanning electron microscopy and compression testing was performed. The properties are shown in Table 1.

(4) Preparation of PBST foaming sheet:

the PBST foamed sheet of the above step (3) was cut into a sheet having a thickness of 1mm using an automatic slicer, and the tolerance thereof is shown in table 1.

Example 5

The procedure of example 1 is repeated except that the foaming agent is changed to a mixture of nitrogen and carbon dioxide in a mixing ratio of 1:4.

Comparative example 1

This comparative example is for explaining the reference PBST raw material, foamed sheet and foamed sheet.

PBST raw materials:

copolyester PBST1 was prepared in the same manner as in example 1: the copolyester PBST1 was prepared from 423.8g of terephthalic acid (PTA), 330g of Succinic Acid (SA), 650g of 1, 4-Butanediol (BDO) and 1g of glycerol, and had a melt index of 44.9g/10min at 190℃and a load of 2.16 kg. No chain extension modification was performed.

Preparation of PBST composition, foamed sheet and sheet:

PBST compositions, foamed sheets and foamed sheets were prepared in the same manner as in example 1. Except that the PBST was replaced with the same parts by weight of the above PBST1 of this comparative example, as a result, a satisfactory foamed sheet could not be obtained, and the appearance and cells were severely distorted.

Comparative example 2

This comparative example is for illustration of reference PBAT raw materials, foamed sheets and foamed sheets.

Copolyester PBAT1 was prepared starting from 423.8g of terephthalic acid (PTA), 466.7g of 1, 6-Adipic Acid (AA), 650g of 1, 4-Butanediol (BDO) and 0.5g of pyromellitic dianhydride, and had a melt index of 31.7g/10min at 190℃and a load of 2.16 kg. Chain extension is not performed.

A PBAT composition, a foamed sheet and a foamed sheet were prepared in accordance with the method of example 2. Except that the PBAT was replaced with the same parts by weight of the PBAT1 described above in this comparative example, as a result, a satisfactory foamed sheet could not be obtained, and the appearance and cells were severely distorted.

Comparative example 3

This comparative example is for illustrating the PBST chain-extended modified product provided by the present invention, the expanded beads and the attempt to cut the sheet after the expanded beads were molded.

(1) Preparation of PBST103 composition:

preparation of PBST103 composition was the same as in example 4.

(2) Preparation of PBST103 expanded beads:

adding the PBST103 composition obtained in the step (1) and a dispersing medium of deionized water, a surfactant of sodium dodecyl benzene sulfonate, a dispersing agent of kaolin and a dispersing enhancer of aluminum sulfate into an autoclave at one time, and uniformly mixing, wherein the dosage of the dispersing medium is 3000 parts by weight, the dosage of the surfactant is 0.3 part by weight, the dosage of the dispersing agent is 4.5 parts by weight and the dosage of the dispersing enhancer is 0.15 part by weight relative to 100 parts by weight of PBST103 composition granules.

The autoclave was closed with the lid closed, the residual air in the autoclave was evacuated using carbon dioxide, after which carbon dioxide was continuously fed into the autoclave, heating was started and the pressure in the autoclave was preliminarily adjusted until it stabilized, and then the autoclave was stirred at a stirring speed of 100rpm to heat the temperature in the autoclave to 126℃at a constant speed.

The pressure in the autoclave was adjusted to 5MPa and the temperature was raised to 126 c at an average heating rate of 0.1 c/min, followed by continuous stirring at the above pressure and temperature for 0.5 hours.

The discharge port of the autoclave was opened to allow the material in the autoclave to drain into the collection tank to obtain foamed beads, and carbon dioxide gas was fed while discharging was performed so that the pressure in the autoclave was maintained near the foaming pressure before all the particles were completely foamed and entered into the collection tank.

After the beads were collected, they were dehydrated and dried, and PBST103 expanded beads having a particle diameter of 2.8 to 3.35mm were sieved out using a sieve having a pore diameter of 3.35mm and a pore diameter of 2.8 mm.

(3) Preparation of PBST103 foaming bead molding plate

The PBST103 expanded beads obtained in the step (2) were molded under a pressure of 0.66MPa using a molding machine (Kurtz T-Line, hereinafter the same shall apply, manufactured by Kurtz Ersa, germany), and then the obtained molded body was cured under a condition of a temperature of 100℃and a pressure of standard atmospheric pressure for 24 hours, to obtain a molded sheet. The volume of the plate is 800mm by 60mm. The molded articles were tested for expansion ratio, cell size, compressive strength, and other performance parameters as shown in Table 1.

(4) Preparation of PBST103 foamed sheet:

The PBST103 foamed bead molded sheet obtained in the step (3) cannot obtain a uniform and complete large-area sheet by adopting the sheet preparation method of example 2.

Comparative example 4

Example 1 was repeated except that the cell nucleating agent was talc, which was produced by DalianFuji mineral company, and the particle size distribution was 2 to 5. Mu.m. It can be seen from fig. 3 and 4 that the cell diameter distribution is wide, between several tens of μm and 300 μm, and the cell wall is smooth and complete, but the cell shape is not regular enough, and there is a degree of distortion.

Comparative example 5

Example 2 was repeated except that the cell nucleating agent was talc, which was produced by DalianFuji mineral company, and the particle size distribution was 2 to 5. Mu.m.

Comparative example 6

Styrene-maleic anhydride-methacrylate terpolymer microspheres in the prior art are used as cell nucleating agents. Wherein the molar content of the maleic anhydride structural unit is 45%, the molar content of the styrene structural unit is 35%, the molar content of the methacrylate structural unit is 20%, and the average particle diameter is 4. Mu.m. The other dosage ratios were the same as in example 1.

TABLE 1

	Expansion ratio	Cell density, per cm ³	Average pore size μm	Sheet thickness mm	Tolerance of	Compressive strength MPa
							Example 1	10.22	5.7*10 ⁶	79.7	2.04	0.02	3.86
Example 2	7.96	2.5*10 ⁴	145.6	1.53	0.02	3.21
							Example 3	18.93	8.2*10 ⁷	108.8	0.51	0.03	2.58
Example 4	24.34	2.0*10 ⁹	115.6	1.03	0.03	1.55
							Example 5	8.87	1.3*10 ⁶	93.1	1.92	0.04	3.30
Comparative example 1	Without any means for	Without any means for	Without any means for	Without any means for	Without any means for	Without any means for
							Comparative example 2	Without any means for	Without any means for	Without any means for	Without any means for	Without any means for	Without any means for
Comparative example 3	22.56	5.5*10 ⁹	445.7	Without any means for	Without any means for	0.38
							Comparative example 4	8.28	1.4*10 ⁵	262.3	1.88	0.06	1.88
Comparative example 5	6.11	2.5*10 ⁴	321.5	1.59	0.06	1.97
							Comparative example 6	7.07	3.8*10 ⁴	248.6	2.10	0.05	1.72

As can be seen from examples 1 to 5, the PBST composition obtained by chain extension was used as a base resin, and a foam sheet having dense and uniform cells was obtained by a compression molding foaming method. The supercritical gases such as carbon dioxide, nitrogen and the like can be used as foaming agents to achieve good foaming effect, the cell density is high, the cell size is small, and the compression strength is excellent. But the foam material obtained by PBAT has the advantages of cell combination and lower compression strength. As can be seen from comparative examples 1-2, PBST obtained without modification could not be subjected to compression molding foaming to obtain a foamed sheet of acceptable quality, as compared with the foamed material obtained by the PBST chain-extended modified product.

Example 4 compared with comparative example 3 shows that a high-rate foamed sheet excellent in performance can be obtained also by autoclave foaming and secondary molding of the PBST103 composition. However, the area of the foaming plate is small due to the limitation of the secondary forming die; and the large cell structure inside the beads and the forming mode that the beads are mutually adhered enable the foaming plate to be cut into sheets smoothly.

It can be seen from comparative examples 4 to 5 that the control of cell structure and mechanical properties of the PBST foamed sheet obtained using the ternary polymerization microsphere as a cell nucleating agent are superior to those of the PBST foamed sheet obtained using conventional talc powder as a cell nucleating agent.

As can be seen from comparative example 6, the control of cell structure and mechanical properties of the PBST foamed sheet obtained by using the maleic anhydride-styrene- α -methylstyrene copolymer microspheres provided by the present invention as a cell nucleating agent are superior to those of the PBST foamed sheet obtained by using the styrene-maleic anhydride-acrylate terpolymer microspheres in the prior art as a cell nucleating agent.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims

1. A fatty aromatic copolyester foaming composition, characterized in that the composition comprises a modified fatty aromatic copolyester and a cell nucleating agent;

the cell nucleating agent is used in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the modified aliphatic aromatic copolyester;

the modified aliphatic aromatic copolyester is prepared by modifying aliphatic aromatic copolyester through a chain extender;

the molar content of the structural unit provided by maleic anhydride is 48 to 51 mol% and the molar content of the structural unit provided by styrene is 10 to 45% based on the total amount of the maleic anhydride-styrene-alpha-methylstyrene copolymer microspheres; the molar content of the structural units provided by the alpha-methylstyrene is from 10 to 45%.

2. The composition of claim 1 wherein the cell nucleating agent is present in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the modified aliphatic aromatic copolyester;

and/or the particle size of the maleic anhydride-styrene-alpha-methyl styrene copolymer microsphere is 800-1600nm;

and/or the modified aliphatic aromatic copolyester has a melt index of 1-3g/10min at 190 ℃ and a load of 2.16 kg;

And/or the molecular weight distribution of the modified aliphatic aromatic copolyester is 3-10.

3. The composition of claim 1 or 2, wherein the maleic anhydride-styrene-a-methylstyrene copolymer microspheres have a molecular weight distribution of 4-8;

and/or the molecular weight distribution of the modified aliphatic aromatic copolyester is 5-7.

4. The composition according to claim 1 or 2, wherein the composition further comprises an antioxidant in an amount of 0.01 to 3 parts by weight based on 100 parts by weight of the modified aliphatic aromatic copolyester;

and/or the antioxidant is selected from phenolic antioxidants and/or phosphite antioxidants.

5. The composition according to claim 1 or 2, wherein the composition further comprises an antioxidant in an amount of 0.1 to 0.5 parts by weight based on 100 parts by weight of the modified aliphatic aromatic copolyester;

and/or the antioxidant is a phenolic antioxidant and a phosphite antioxidant, and the weight ratio of the phenolic antioxidant to the phosphite antioxidant is 0.005-2:0.002-1.

6. The composition of claim 5, wherein the antioxidants are phenolic antioxidants and phosphite antioxidants, and the weight ratio of the phenolic antioxidants to the phosphite antioxidants is 0.03-0.35:0.02-0.15;

And/or the antioxidant is selected from at least one of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], n-stearyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 2' -methylenebis- (4-methyl-6-tert-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, tris (2, 4-di-tert-butylphenyl) phosphite, bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite and bis (2, 6-di-tert-butyl-4-tolyl) pentaerythritol diphosphite.

7. The composition according to claim 1 or 2, wherein the chain extender is used in an amount of 0.01-5wt% of the aliphatic aromatic copolyester, and the molecular weight distribution of the maleic anhydride-styrene- α -methylstyrene copolymer microspheres is 2-12;

and/or the chain extender is an organic peroxide, and the half-life period of the organic peroxide is 0.2-10min.

8. The composition of claim 1 or 2, wherein the chain extender is present in an amount of 0.2-2wt% of the aliphatic aromatic copolyester;

and/or the chain extender is an organic peroxide, and the half-life period of the organic peroxide is 0.2-2min.

9. The composition of claim 1 or 2, wherein the chain extender is selected from at least one of alkyl peroxides, acyl peroxides, and peroxyesters.

10. The composition of claim 9, wherein the alkyl peroxide is selected from at least one of dicumyl peroxide, 2, 5-dimethyl-2, 5-di (t-butyl) hexane peroxide, and di (t-butylperoxyisopropyl) benzene;

the acyl peroxide is selected from dibenzoyl peroxide and/or lauroyl peroxide.

11. The composition according to claim 1 or 2, wherein the aliphatic aromatic copolyester is obtained by copolycondensation of monomer a, monomer b, monomer c and monomer d in the presence of a catalyst;

and/or the monomer a is selected from aromatic dibasic acid or ester derivative thereof; the monomer b is selected from C ₂ -C ₁₀ One or more of aliphatic diols or alicyclic diols; the monomer C is selected from C ₄ -C ₂₀ Aliphatic binary of (2)An acid or an ester derivative thereof; the monomer d is selected from one or more of polyols, polycarboxylic acids or anhydrides with functionality greater than 2.

12. The composition according to claim 11, wherein the monomer a is selected from terephthalic acid and/or dimethyl terephthalate; the monomer b is selected from 1, 3-propanediol and/or 1, 4-butanediol; the monomer c is at least one selected from succinic acid, dimethyl succinate, adipic acid and dimethyl adipate; the monomer d is at least one selected from pyromellitic dianhydride, glycerol and pentaerythritol;

And/or the molar ratio of monomer a, monomer b, monomer c and monomer d satisfies the following condition: (a+c): b is 1:0.8-3; (a+c): d is 100-2000:1, a:c is 60:40-0:100;

and/or the catalyst comprises a first catalyst, a second catalyst and a third catalyst;

the first catalyst is selected from the group consisting of oxides of M, M (OR ¹ ) n and M (OOCR) ² ) _m Wherein M is titanium, antimony or zinc, n and M are each independently of the other the valence of M, R ¹ Is C ₁ -C ₁₀ Alkyl of R ² Is C ₁ -C ₂₀ Alkyl of (a);

the second catalyst is RE (R) ³ ) ₃ Wherein RE is a rare earth metal element, R ³ Is selected from halogen, alkoxy, aryloxy, acetylacetonate and R ⁴ At least one of COO-groups, R ⁴ Is C ₁ -C ₃₀ Alkyl of (a);

the third catalyst is at least one organotin compound;

and/or the molar ratio of the total addition of the catalyst to the monomer (a+c) is 1:1000-20000;

and/or, a first catalyst: and a second catalyst: the molar ratio of the third catalyst is 0.1-20:0.1-10:1.

13. The composition according to claim 12, wherein the molar ratio of the total addition of catalyst to monomer (a+c) is 1:3000-10000;

and/or, a first catalyst: and a second catalyst: the molar ratio of the third catalyst is 0.5-5:0.5-5:1.

14. Composition according to claim 1 or 2, wherein maleic anhydride provides a molar content of structural units of 49-50% based on the amount of total material of the maleic anhydride-styrene-a-methylstyrene copolymer microspheres; the molar content of the structural units provided by styrene is 15-45%; the molar content of the structural units provided by the alpha-methylstyrene is from 10 to 40%.

15. The composition according to claim 1 or 2, wherein the maleic anhydride-styrene- α -methylstyrene copolymer microsphere is a copolymer obtained by polymerizing maleic anhydride, styrene, α -methylstyrene and an initiator in the presence of an inert atmosphere after dissolving them in an organic medium to form a homogeneous solution.

16. The composition of claim 15, wherein the total mass concentration of maleic anhydride, styrene, and a-methylstyrene is 4-22wt%, based on the total weight of the homogeneous solution;

and/or, the mass concentration of the initiator is 0.4-4wt%, based on the total weight of the homogeneous solution;

and/or the initiator is selected from organic peroxides and/or azo compounds;

and/or the organic medium is an organic acid alkyl ester;

And/or, the temperature of the polymerization reaction is 60-95 ℃; the polymerization time is 2-24h.

17. The composition of claim 16, wherein the total mass concentration of maleic anhydride, styrene and a-methylstyrene is 6-19wt%, based on the total weight of the homogeneous solution;

and/or, the mass concentration of the initiator is 0.6 to 3.6wt%, based on the total weight of the homogeneous solution;

and/or, the temperature of the polymerization reaction is 65-76 ℃; the polymerization time is 4-8h.

18. Composition according to claim 16 or 17, wherein the initiator is present in a mass concentration of 1-3wt%, based on the total weight of the homogeneous solution.

19. The composition of claim 16 or 17, the organic peroxide being selected from at least one of dibenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, lauroyl peroxide, t-butyl peroxybenzoate, diisopropyl peroxydicarbonate, and dicyclohexyl peroxydicarbonate;

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

20. The composition of claim 16 or 17, wherein the alkyl ester of an organic acid has the formula R ₁ COOR ₂ Wherein R is ₁ Selected from H, C ₁ -C ₄ At least one of alkyl, phenyl and benzyl, R ₂ Is substituted or unsubstituted C ₁ -C ₁₀ Is a hydrocarbon group.

21. The composition of claim 20, wherein R ₁ Is substituted or unsubstituted C ₁ -C ₄ Alkyl or phenyl, R ₂ Is substituted or unsubstituted C ₁ -C ₇ Is a hydrocarbon group.

22. The composition of claim 16 or 17, wherein the organic 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, amyl 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.

23. A method for preparing a fatty aromatic copolyester foamed sheet, which is characterized in that the fatty aromatic copolyester foamed sheet is prepared by foaming the fatty aromatic copolyester foamed composition according to any one of claims 1 to 22;

The preparation method comprises the following steps: melting and granulating the aliphatic aromatic copolyester foaming composition according to any one of claims 1-22 to obtain aliphatic aromatic copolyester granules, extruding the granules into a plate, and foaming;

the foaming is a mould pressing foaming method;

the compression molding foaming method comprises the following steps:

(1) Heating the foaming mould to a foaming temperature;

24. The method of claim 23, wherein the foamed sheet has a volume expansion ratio of 2-40 times; the average foam cells of the foaming plate are 30-400 mu m; the cell density of the foaming plate is 1 multiplied by 10 ³ Up to 1X 10 ¹² Individual/cm ³ The method comprises the steps of carrying out a first treatment on the surface of the The compression strength is 0.1-5MPa.

25. The method of claim 23 or 24, wherein the foamed sheet has a volume expansion ratio of 7-25 times; the average foam cells of the foaming plate are 75-200 mu m; the cell density of the foaming plate is 1 multiplied by 10 ⁴ Up to 1X 10 ¹⁰ Individual/cm ³ The method comprises the steps of carrying out a first treatment on the surface of the The compression strength is 0.5-4MPa.

26. The process of claim 23 or 24, wherein the foaming temperature is 0.1-40 ℃ lower than the melting temperature of the aliphatic aromatic copolyester.

27. The method of claim 23 or 24, wherein the foaming temperature is 110-150 ℃;

the foaming pressure is 8-40MPa;

the foaming agent is a supercritical fluid foaming agent;

and/or the pressure of the foaming agent is 5-30MPa;

and/or the foaming agent is diffused to the required saturation time of 10-600min.

28. The method of claim 23 or 24, wherein the foaming pressure is 10-25MPa;

and/or the foaming agent is supercritical carbon dioxide and/or supercritical nitrogen, wherein the volume ratio of the supercritical carbon dioxide to the supercritical nitrogen is 0.1-99.9;

and/or the pressure of the foaming agent is 10-20MPa;

and/or the foaming agent is diffused to a desired saturation time of 30-300min.

29. The method of claim 28, wherein the volume ratio of supercritical carbon dioxide to supercritical nitrogen is 50-99.9.

30. A foamed aliphatic aromatic copolyester sheet produced by the production method according to any one of claims 23 to 29.

31. A foamed sheet of a fatty aromatic copolyester, characterized in that it is produced from the foamed sheet of a fatty aromatic copolyester of claim 30.

32. The aliphatic aromatic copolyester foamed sheet according to claim 31, wherein the foamed sheet has a thickness of 0.3mm or more; the thickness tolerance of the foaming sheet is 0.01-0.05.

33. The aliphatic aromatic copolyester foamed sheet according to claim 32, wherein the foamed sheet has a thickness of 0.5mm or more; the thickness tolerance of the foaming sheet is 0.02-0.04.

34. A method for preparing the aliphatic aromatic copolyester foam sheet according to any one of claims 30 to 33, wherein the foam sheet is obtained by cutting and molding the foam sheet according to claim 30.