Transparent, wear-resistant, heat-resistant, high-strength and tough degradable polyester composition, preparation method and application

Abstract

The present invention relates to a degradable polyester composition with transparency, wear resistance, heat resistance, high strength and toughness, and a preparation method and application thereof. The degradable polyester composition comprises the following raw materials in parts by weight: 100 parts of degradable polyester, 0.5 - 1 part of hydrolysis inhibitor, 0.5 - 2 parts of chain extender, 1 - 3 parts of hardening and lubricating agent, 0.5 - 2 parts of transparent brightening agent, and 0.1 - 0.3 part of antioxidant. The products prepared from the degradable polyester composition of the present invention have excellent comprehensive properties of transparency, wear resistance and heat resistance, solving the problems of non-transparency, poor wear resistance, insufficient toughness of degradable polyester material products on the market, and poor comprehensive properties despite good single performance; the light transmittance of the degradable polyester composition is as high as 95%, and the light transmittance after wear resistance test also reaches more than 90%, and the notched impact strength is above 10 KJ / m<supgt;2< / supgt>.

Description

Technical Field

[0001] The invention relates to the field of degradable polyester materials, and in particular to a transparent, wear-resistant, heat-resistant and high-strength degradable polyester composition and a preparation method and application thereof. Background Art

[0002] With the development of society, people's demands for living environment are becoming more and more diversified, and a healthy environment is what people yearn for. The use of plastics has brought about serious white pollution and marine pollution while facilitating people's lives. The degradation cycle of traditional plastics is too long, which brings serious environmental pressure. The research and utilization of fully biodegradable materials play an important role in solving white pollution. While fully biodegradable materials meet the diversity of people's lives, the research and development of biodegradable materials with wider applicability and more comprehensive performance has become an important direction of development.

[0003] Degradable materials are mostly polyesters, such as polylactic acid, poly(lactide-glycol), poly(butylene succinate), poly(butylene terephthalate-adipate), poly(glycolic acid), etc. Degradable materials have good biocompatibility and biodegradability. After a period of use, they can gradually degrade under the conditions of microorganisms, water, light, etc., and eventually become carbon dioxide and water that are completely harmless to organisms and plants. They have good ecological benefits and are fully in line with the development background of carbon reduction and plastic reduction. Among them, polylactic acid is naturally derived, the raw materials are renewable, it has excellent tolerance, high hardness, and mechanical properties are better than traditional general-purpose resins. However, due to its own structure, its flexibility is poor, its impact resistance and elongation at break are low, and the heat resistance of the product also presents insufficient disadvantages. Polyglycolic acid has super high strength and modulus, which is comparable to traditional plastic nylon, but its toughness is low, and the elongation at break of unmodified polyglycolic acid is only about 10%, which seriously limits its use. Polyglycolic acid is a crystalline polymer material with a crystallinity of 40-80%, but its spherulite diameter is too large, which makes its products opaque and affects the appearance. Polybutylene terephthalate-adipate has excellent flexibility and is the first choice for producing degradable films. It is also often blended with polylactic acid and polyglycolic acid for toughness modification. However, its own strength is low and it degrades slowly. Existing degradable materials and their products have little research on wear resistance. The wear resistance of materials directly affects consumers' physical inspection experience. In order to save storage space, lunch boxes, disposable packaging boxes, etc., multiple products are stacked together. During handling and transportation, friction will occur, causing surface scratches and even surface atomization, which seriously affects the appearance of the product, thereby reducing the consumer's use experience. Degradable products have certain requirements for heat resistance according to different usage scenarios, which puts higher requirements on the heat resistance of materials. They should not bend, deform, or affect use when heated at a certain temperature. The heat resistance of existing degradable materials needs to be improved.

[0004] The disclosed patents rarely report on the transparency and wear resistance of degradable polyester materials. Transparency greatly improves the beauty of the products, and wear resistance improves the consumer experience. Giving transparency and wear resistance to degradable polyester materials can improve their scope of application. For example, the patent with publication number CN116731481 discloses a polybutylene succinate / polybutylene terephthalate-adipate biodegradable composite material enhanced by a nucleating agent and a chain extender. The composite material has a high elongation at break, but the strength is only 22-25MPa, and no obvious enhancement effect is seen. It is not fully explained whether the change in performance is promoted by the nucleating agent or the filler promotes nucleation crystallization. The patent with publication number CN114507425A discloses a method for preparing a heat-resistant polylactic acid composition and a polylactic acid nucleating agent. Polylactic acid is mixed with a nucleating agent prepared from mandelic acid and metal carboxylates in a certain proportion and kneaded. The results show that the crystallization rate of polylactic acid products is rapidly improved, and the heat-resistant temperature of the modified polylactic acid is improved, but no heat-resistant test is provided for more practical application scenarios. The patent does not mention the comprehensive material properties such as toughness and transparency of modified polylactic acid, and the actual effect remains to be studied. The patent with publication number CN114075376A discloses a toughened and degradable polyglycolic acid composition, including polyglycolic acid, biodegradable polyester, and compatibilizer. The main body of the composition is a biodegradable material, and there is a non-degradable maleic anhydride graft copolymer in the system. According to the embodiment of this patent, when the ratio of polyglycolic acid and polybutylene terephthalate-adipate is determined, the notched impact strength and elongation at break still have room for improvement, indicating that the compatibility of polyglycolic acid and polybutylene terephthalate-adipate has not reached an ideal state. Publication No. CN113980436A provides a patent for a modified polyester transparent composite material, which includes thermoplastic aromatic polyester, methyl methacrylate, compatibilizer, etc., which is prepared by blending and molding. The modified material has high light transmittance and excellent mechanical properties, but the material is a non-degradable material, and the processing temperature is as high as 300°C, at which temperature polymethyl methacrylate will have a risk of decomposition. In view of this, the present invention provides a transparent, wear-resistant, heat-resistant, high-strength and tough degradable polyester composition, a preparation method and an application. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a transparent, wear-resistant, heat-resistant, high-strength and tough degradable polyester composition and a preparation method and application thereof. The purpose is to provide a degradable polyester composition material with excellent comprehensive properties of transparency, wear resistance and heat resistance.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] In the first aspect, a transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition comprises the following raw materials in parts by weight: 100 parts of degradable polyester, 0.5-1 parts of anti-hydrolysis agent, 0.5-2 parts of chain extender, 1-3 parts of hardening and lubricating agent, 0.5-2 parts of transparent brightener and 0.1-0.3 parts of antioxidant.

[0008] The beneficial effects of the present invention are as follows: the products prepared by using the degradable polyester composition of the present invention have excellent comprehensive properties of transparency, wear resistance and heat resistance, and solve the problems of opacity, poor wear resistance, insufficient toughness, good single performance but poor comprehensive performance of the degradable polyester material products on the market; the light transmittance of the degradable polyester composition is as high as 95%, and the light transmittance after the wear resistance test is also above 90%, and the notched impact strength is 10KJ / m 2 above.

[0009] Based on the above technical solution, the present invention can also be improved as follows.

[0010] The beneficial effect of adopting the above further solution is that the above transparent brightener greatly improves the transparency and wear resistance of the product.

[0011] Further, the degradable polyester comprises the following components in parts by weight: 0-100 parts of polylactic acid, 0-100 parts of poly(lactide-glycol), 0-100 parts of poly(butylene succinate), 0-100 parts of poly(butylene terephthalate-adipate), and 0-100 parts of poly(glycolic acid);

[0012] The melt index of the polylactic acid at 230°C and a load of 2.16kg is 10-100g / 10min, and the water content is less than 100ppm; the melt index of the poly(lactide-glycol) at 190°C and a load of 2.16kg is 10-50g / 10min, the viscosity is 0.5-5mPa.s, and the water content is less than 100ppm; the melt index of the poly(butylene succinate) at 190°C and a load of 2.16kg is 5-50g / 10min, and the water content is less than 100ppm;

[0013] The melt index of the polybutylene terephthalate-adipate at 190° C. and a load of 2.16 kg is 2-30 g / 10 min, and the moisture content is less than 100 ppm; the melt index of the polyglycolic acid at 230° C. and a load of 2.16 kg is 10-100 g / 10 min, and the moisture content is less than 100 ppm.

[0014] Further, the degradable polyester comprises the following components in parts by weight: 50-60 parts of polylactic acid, 20-50 parts of poly(lactide-glycol), 20-40 parts of poly(butylene succinate), 10-40 parts of poly(butylene terephthalate-adipate), and 50-70 parts of poly(glycolic acid);

[0015] The melt index of the polylactic acid at 230°C and a load of 2.16kg is 15-50g / 10min, and the moisture content is less than 100ppm; the melt index of the polylactide at 190°C and a load of 2.16kg is 10-20g / 10min, the viscosity is 1.0-2.0mPa.s, and the moisture content is less than 100ppm; the melt index of the polybutylene succinate at 190°C and a load of 2.16kg is 10-25g / 10min, and the moisture content is less than 100ppm; the melt index of the polybutylene terephthalate-adipate at 190°C and a load of 2.16kg is 2-10g / 10min, and the moisture content is less than 100ppm; the melt index of the polyglycolic acid at 230°C and a load of 2.16kg is 20-50g / 10min, and the moisture content is less than 100ppm.

[0016] Further, the transparent brightener includes at least one of ethylene methyl acrylate copolymer, glycolic acid lactic acid copolymer, and glycolic acid caprolactone copolymer;

[0017] The molecular formula of the ethylene methyl acrylate copolymer is The mass content of methyl acrylate is 20%-40%, preferably 20-30%, more preferably 24-25%, such as one of ExxonMobil's Optema TC 111, 121, 221 brands, or DOW's ELVALOY AC 1125, 1209, 1224, 1330, 1820, 2102, 2615, 3427, 34035, 12024S brands;

[0018] The molecular formula of the glycolic acid-lactic acid copolymer is The weight average molecular weight is 10000-20000, and it can be prepared by the following steps: adding a condensation polymerization catalyst to a certain proportion of lactic acid and glycolic acid, and carrying out the condensation polymerization reaction at 120-160°C and a pressure of 0.065MPa for 3-6 hours. The specific synthesis equation is as follows:

[0019]

[0020] The glycolic acid caprolactone copolymer The weight average molecular weight is 10000-20000, and it can be prepared by the following steps: adding a condensation polymerization catalyst to a certain proportion of caprolactone and glycolic acid, and carrying out the condensation polymerization reaction at 120-160°C and a pressure of 0.065MPa for 3-6 hours. The specific synthesis equation is as follows:

[0021]

[0022] Further, the anti-hydrolysis agent includes at least one of carbodiimide, 2-oxazoline, 3-oxazoline, 4-oxazoline, phenyl glycidyl ether, triglycidyl isocyanate (TGIC), bisphenol A diglycidyl ether, tetrakis(phenylglycidyl ether)ethane, trimethoxy[3-(glycidyl ether)propyl]silane, triethyl phosphate (TCEP), tributyl phosphate (TBP) and triisopropyl phosphate (TIPA);

[0023] and / or the chain extender includes at least one of BASF ADR-4400, ADR-4370F, ADR-4468, and CE-2140 (domestic); the chain extender has an epoxy equivalent of 200-400 g / eq and a weight average molecular weight of 3000-50000 g / mol;

[0024] and / or the hardening and lubricating agent includes at least one of wax powder, ethylene bis stearamide (EBS), pentaerythritol stearate (PETS), edible white oil, epoxidized soybean oil, silicone powder, PTFE powder, molybdenum disulfide, and polysiloxane;

[0025] And / or the antioxidant includes at least one of BASF Irganox 1010, 1035, 245, 1076, 1098, 1330, 1726, 565, 168, 626, DSTDP, DLTP, 412S, and PEP-36.

[0026] Furthermore, the chain extender has an epoxy equivalent of 220-300 g / eq and a weight average molecular weight of 5000-30000 g / mol.

[0027] In a second aspect, a method for preparing a transparent, wear-resistant, heat-resistant, and high-strength degradable polyester composition comprises the following steps:

[0028] (1) fully dispersing an anti-hydrolysis agent, a chain extender, a hardening and lubricating agent, a transparent brightening agent, and an antioxidant to form granules to obtain a granular compounding auxiliary agent;

[0029] (2) Extruding the degradable polyester and the granular compounding auxiliary agent in an extruder to obtain material strips; pelletizing the material strips to obtain granular materials; extruding the granular materials in an injection molding machine, and cooling them by alternating hot and cold processes to obtain plastic products.

[0030] The beneficial effects of adopting the above scheme are: the additives (anti-hydrolysis agent, chain extender, hardening and lubricating agent, transparent brightener, antioxidant) are made from powder to granular compound additives, which are more evenly dispersed in the blending system and exert the effect of the additives to a greater extent; the crystallization and molding of the plastic products in the mold are well controlled by alternating hot and cold cooling, and the transparency and performance of the products are greatly improved; the degradable polyester, additives and process are combined to improve the transparency, wear resistance, heat resistance, strength and toughness of the plastic products obtained, and make them more comprehensive and more applicable.

[0031] Furthermore, in step (1), the dispersion speed is 1000-1500 rpm / min, and the dispersion time is 5-10 min; hot surface molding is used to form particles to obtain a particle-shaped compound auxiliary agent.

[0032] Further, in step (2), the extruder is provided with a gradient temperature of a front low temperature, a middle high temperature and a rear low temperature, and the gradient temperature is 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, the main engine speed is 200-250rpm / min, and the feed rate is 220-300rpm / min; the material strips are pelletized by at least one of air-cooled pelletizing, water-cooled pelletizing, underwater pelletizing and film surface hot cutting;

[0033] In step (2), the injection molding machine is a single screw injection molding machine, with an aspect ratio of 20-33, a clamping force of 1000KN, a clamping force of 1000KN, a maximum mold opening stroke of 500mm, an ejection stroke of 150mm, and a gradient temperature of low temperature in the front section and high temperature in the middle section of the injection molding machine, and the gradient temperatures are 180-235°C, 180-235°C, 180-235°C, 180-235°C, 180-235°C, and 180-235°C respectively; the storage time is 10-15s, the injection pressure is 90-120MPa, and the back pressure is 8-12MPa;

[0034] In step (2), the total cooling time by alternating hot and cold is 10-50s, the time interval of alternating hot and cold is 3-6s, and the mold temperature is 50-100°C.

[0035] In a third aspect, the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition is used to prepare a plastic product by injection molding, and / or blow molding, and / or extrusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1This is a diagram of a mold control system for alternating hot and cold rapid cooling and heating of the present invention; DETAILED DESCRIPTION

[0037] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0038] The melt index test method in the present invention is based on GB / T3682-2000 "Determination of mass flow rate and volume flow rate of thermoplastic melts", and each sample is tested 3 times to obtain an average value.

[0039] The polymer viscosity test method in the present invention is GB / T1632.1-2008 "Determination of viscosity of dilute polymer solutions using a capillary viscometer for plastics".

[0040] The transparent extender of the present invention:

[0041] (1) Ethylene methyl acrylate copolymer

[0042] The weight content of methyl acrylate in the ethylene methyl acrylate copolymer is 20%-40%, preferably 20-30%, and more preferably 24-25%, any one of ExxonMobil's Optema TC 111, 121, 221 brands, or DOW's ELVALOY AC 1125, 1209, 1224, 1330, 1820, 2102, 2615, 3427, 34035, 12024S brands.

[0043] (2) Preparation of transparent extender A

[0044] 0.1-2 wt %, preferably 0.5-1 wt % condensation polymerization catalyst is added to lactic acid and glycolic acid in a molar ratio of 50:50, preferably 60:40, and more preferably 75:25, and the mixture is heated to 120-160° C., preferably 130-160° C., and more preferably 150-160° C., with stirring, and the polycondensation reaction is carried out for 3-6 hours at a pressure below 0.065 MPa, preferably below 0.035 MPa, and more preferably 0.01 MPa. The molecular weight and distribution of the transparent extender A prepared according to the above preparation method are shown in Table 1.

[0045] (3) Preparation of transparent extender B

[0046] 0.1-2wt%, preferably 0.5-1%wt% of a condensation polymerization catalyst is added to caprolactone and glycolic acid in a molar ratio of 50:50, preferably 60:40, and more preferably 75:25, and the mixture is heated to 120-160°C, preferably 130-160°C, and more preferably 150-160°C with stirring, and the polycondensation reaction is carried out for 3-6 hours at a pressure below 0.065MPa, preferably below 0.035MPa, and more preferably 0.01MPa; the molecular weight and distribution of the transparent extender B prepared according to the above preparation method are shown in Table 1.

[0047] Table 1 Molecular weight and distribution of transparent extenders (GPC)

[0048]

[0049] Example 1

[0050] The transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment includes the following raw materials in parts by weight: the degradable polyester includes 60 parts by weight of polylactic acid, with a melt index of 30g / 10min; 20 parts by weight of poly(lactide) with a melt index of 20g / 10min and a viscosity of 1.0mPa.s; 20 parts by weight of poly(butylene terephthalate-adipate) with a melt index of 8g / 10min; mixed evenly; the anti-hydrolysis agent is carbodiimide, 0.3 parts by weight; the chain extender is ADR-4400, 0.5 parts by weight, with an epoxy equivalent of 485g / eq and a weight average molecular weight of 7100g / mol; the hardening and lubricating agent is wax powder, 1 part by weight; the transparent brightener is ethylene methyl acrylate (12024S), 0.5 parts by weight; the antioxidant is 1010 0.2 parts by weight, the antioxidant 168 0.2 parts by weight, and the antioxidant DLTP 0.2 parts by weight.

[0051] The preparation method of the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment comprises the following steps:

[0052] (1) The above-mentioned anti-hydrolysis agent, chain extender, hardening and lubricating agent, transparent brightening agent, and antioxidant are homogenized and stirred at 1000 rpm / min for 5 minutes in a high-speed disperser equipped with cooling, and then pressed into granules by hot surface molding at a speed of 50 rpm / min to prepare a granular compound auxiliary agent;

[0053] (2) Polylactic acid, poly(lactide-glycol), poly(butylene terephthalate-adipate) and granular compounding additives were uniformly mixed and added into a twin-screw extruder at temperatures of 150°C, 160°C, 170°C, 180°C, 190°C, 190°C, 190°C, 190°C, 190°C, 190°C, 185°C, 175°C, 170°C, 170°C and 170°C, respectively; the main engine speed was 220 rpm / min, and the feed rate was 22 0rpm / min; the extruded material strips are conveyed by the crawler, and a cooling fan is installed above the crawler. The material is cooled and shaped and pelletized, and the granular material is ready for molding and processing; the granular material is added to the injection molding machine, the aspect ratio is 25, the temperatures of the first to fifth zones are 180℃, 190℃, 195℃, 195℃, 195℃, respectively, the material storage time is 10s, the injection pressure is 90MPa, the back pressure is 8MPa, the cooling time is 20s, the mold temperature is 60℃ for hot water, 15℃ for cold water, and the interval between cold and hot water is 5s ( Figure 1 ).

[0054] Example 2

[0055] The transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment includes the following raw materials in parts by weight: the degradable polyester includes: 60 parts by weight of polylactic acid, melt index 30g / 10min, 20 parts by weight of polybutylene terephthalate-adipate, melt index 10g / 10min, 20 parts by weight of polybutylene succinate, melt index 25g / 10min, mixed evenly. The anti-hydrolysis agent is carbodiimide, 0.5 parts by weight; the chain extender is ADR-4370F, 0.5 parts by weight, epoxy equivalent 285g / eq, weight average molecular weight 6800g / mol; the hardening and lubricating agent is 2 parts by weight of ethylene bis stearamide, the transparent brightener is transparent extender A0.5 parts by weight, the antioxidant is 1076 0.2 parts by weight, antioxidant 168 0.2 parts by weight, and antioxidant DLTP 0.2 parts.

[0056] The preparation method of the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment comprises the following steps:

[0057] (1) The above-mentioned anti-hydrolysis agent, chain extender, hardening and lubricating agent, transparent brightening agent and antioxidant are homogenized and stirred at 1000 rpm / min for 8 minutes in a high-speed disperser equipped with cooling, and then pressed into granules by hot surface molding at a speed of 50 rpm / min to prepare a granular compound auxiliary agent.

[0058] Polylactic acid, polybutylene succinate, polybutylene terephthalate-adipate and granular compound additives are mixed evenly and added into the twin-screw extruder. The temperatures are 160℃, 170℃, 180℃, 185℃, 185℃, 185℃, 185℃, 185℃, 185℃, 185℃, 185℃, 185℃, 180℃, 170℃, 165℃, 165℃, 165℃; the main engine speed is 230rpm / min, and the feed rate is 250rpm / min; the extruded material strips are conveyed by a crawler belt, and a cooling fan is installed above the crawler belt for cooling, forming and pelletizing, and the granular material is ready for forming and processing. Add the granular material into the injection molding machine with an aspect ratio of 25. The temperatures of the first to fifth zones are 170℃, 175℃, 185℃, 185℃, and 185℃ respectively. The storage time is 10s, the injection pressure is 100MPa, the back pressure is 10MPa, the cooling time is 30s, the mold temperature is hot water at 70℃, cold water at 15℃, hot water insulation for 10s, and cold water for 20s.

[0059] Example 3

[0060] The transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment includes the following raw materials in parts by weight: the degradable polyester includes 70 parts by weight of polyglycolic acid, with a melt index of 30g / 10min; 20 parts by weight of poly(lactide) with a melt index of 20g / 10min and a viscosity of 1.0mPa.s; 10 parts by weight of poly(butylene terephthalate-adipate), with a melt index of 8g / 10min, which are mixed evenly; the anti-hydrolysis agent is phenyl glycidyl ether, 0.5 parts by weight; the chain extender is ADR-4468, 0.5 parts by weight, with an epoxy equivalent of 285g / eq and a weight average molecular weight of 6800g / mol; the hardening and lubricating agent is 3 parts by weight of ethylene bisstearamide, the transparent brightener is 1 part by weight of transparent extender A, the antioxidant is 0.3 parts by weight of 1076, 0.1 parts by weight of antioxidant 626, and 0.1 parts of antioxidant DSTDP.

[0061] The preparation method of the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment comprises the following steps:

[0062] (1) The above-mentioned anti-hydrolysis agent, chain extender, hardening and lubricating agent, transparent brightening agent, and antioxidant are homogenized and stirred at 1200 rpm / min in a high-speed disperser equipped with cooling for 5 minutes, and then pressed into granules by hot surface molding at a speed of 70 rpm / min to prepare a granular compound auxiliary agent;

[0063] (2) Polyglycolic acid, poly(lactide-glycol), poly(butylene terephthalate-adipate) and granular compound additives are uniformly mixed and added into a twin-screw extruder at temperatures of 190°C, 205°C, 215°C, 220°C, 230°C, 230°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 225°C, 215°C, 215°C and 215°C, respectively; the main engine speed is 200rpm / min and the feed rate is 250rpm / min; the extruded material strips are conveyed by a crawler belt, and a cooling fan is installed above the crawler belt for cooling, forming and pelletizing, and the granular material is ready for forming and processing. Add the granular material into the injection molding machine with an aspect ratio of 25. The temperatures of the first to fifth zones are 210℃, 220℃, 230℃, 235℃, and 235℃ respectively. The storage time is 15s, the injection pressure is 110MPa, the back pressure is 10MPa, the cooling time is 30s, the mold temperature is hot water at 80℃, cold water at 15℃, hot water insulation for 10s, and cold water for 20s.

[0064] Example 4

[0065] The transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment includes the following raw materials in parts by weight: the degradable polyester includes 50 parts by weight of polyglycolic acid with a melt index of 30 g / 10 min; 30 parts by weight of polylactic acid with a melt index of 30 g / 10 min; 20 parts by weight of polybutylene terephthalate-adipate with a melt index of 5 g / 10 min, which are mixed evenly; the anti-hydrolysis agent is triglycidyl isocyanate (TGIC), 0.5 parts by weight; the chain extender is 1 part by weight of ADR-4468, with an epoxy equivalent of 285 g / eq and a weight-average molecular weight of 6800 g / mol; the hardening and lubricating agent is 3 parts by weight of edible white oil, the transparent brightener is 1 part by weight of transparent extender A, the antioxidant is 0.3 parts by weight of 1098, 0.1 parts by weight of antioxidant 168, and 0.1 parts of antioxidant DSTDP.

[0066] The preparation method of the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment comprises the following steps:

[0067] (1) The above-mentioned anti-hydrolysis agent, chain extender, hardening and lubricating agent, transparent brightening agent, and antioxidant are homogenized and stirred at 1300 rpm / min in a high-speed disperser equipped with cooling for 5 minutes, and then pressed into granules by hot surface molding at a speed of 70 rpm / min to prepare a granular compound auxiliary agent;

[0068] (2) Polyglycolic acid, polylactic acid, polybutylene terephthalate-adipate and granular compound additives are mixed uniformly and added into a twin-screw extruder at temperatures of 190°C, 205°C, 215°C, 220°C, 230°C, 230°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 225°C, 215°C, 215°C and 215°C, respectively; the main engine speed is 200 rpm / min and the feed rate is 250 rpm / min; the extruded material strips are conveyed by a crawler belt, and a cooling fan is installed above the crawler belt for cooling, forming and pelletizing, and the granular material is ready for forming and processing. Add the granular material into the injection molding machine with an aspect ratio of 33. The temperatures of the first to fifth zones are 210℃, 220℃, 230℃, 230℃, and 235℃ respectively. The storage time is 13s, the injection pressure is 100MPa, the back pressure is 10MPa, the cooling time is 40s, the mold temperature is hot water at 80℃, cold water at 15℃, the hot water is kept warm for 20s, and the cold water is kept warm for 20s.

[0069] Example 5

[0070] The transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment includes the following raw materials in parts by weight: the degradable polyester includes 30 parts by weight of polybutylene succinate, with a melt index of 20g / 10min; 50 parts by weight of poly(lactide) with a melt index of 10g / 10min and a viscosity of 2.0mPa.s; 20 parts by weight of poly(butylene terephthalate-adipate), with a melt index of 2g / 10min, which are mixed evenly; the anti-hydrolysis agent is 1 part by weight of triethyl phosphate (TCEP); the chain extender is 1.5 parts by weight of CE-2140, with an epoxy equivalent of 300g / eq and a weight-average molecular weight of 30000g / mol; the hardening and lubricating agent is 3 parts by weight of silicone powder, the transparent brightening agent is 1 part by weight of transparent extender B, the antioxidant is 0.2 parts by weight of 1076, 0.1 parts by weight of antioxidant 626, and 0.1 parts of antioxidant DSTDP.

[0071] The preparation method of the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment comprises the following steps:

[0072] (1) The above-mentioned anti-hydrolysis agent, chain extender, hardening and lubricating agent, transparent brightening agent and antioxidant are homogenized and stirred at 1200 rpm / min for 8 minutes in a high-speed disperser equipped with cooling, and then pressed into granules by hot surface molding at a speed of 80 rpm / min to prepare a granular compound auxiliary agent.

[0073] (2) Polybutylene succinate, poly(lactide-glycol), poly(butylene terephthalate-adipate) and granular compound additives are uniformly mixed and added into a twin-screw extruder at temperatures of 180°C, 185°C, 190°C, 190°C, 190°C, 190°C, 190°C, 190°C, 190°C, 190°C, 190°C, 180°C, 175°C, 170°C, 170°C and 170°C, respectively; the main engine speed is 250rpm / min and the feed rate is 300rpm / min; the extruded material strips are conveyed by a crawler belt, and a cooling fan is installed above the crawler belt for cooling, forming and pelletizing, and the granular material is ready for forming and processing. The granular material was added into the injection molding machine with an aspect ratio of 33. The temperatures of the first to fifth zones were 185°C, 190°C, 190°C, 190°C, and 190°C respectively. The storage time was 15s, the injection pressure was 90MPa, the back pressure was 10MPa, the cooling time was 15s, and the mold temperature was hot water at 50°C, cold water at 15°C, hot water for 10s, and cold water for 5s.

[0074] Example 6

[0075] The transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment includes the following raw materials in parts by weight: the degradable polyester includes 40 parts by weight of polybutylene succinate, with a melt index of 15g / 10min; 30 parts by weight of poly(lactide-glycol) with a melt index of 10g / 10min and a viscosity of 2.0mPa.s; 30 parts by weight of polylactic acid with a melt index of 30g / 10min, which are mixed evenly;

[0076] The anti-hydrolysis agent is 1 part by weight of bisphenol A diglycidyl ether; the chain extender is 2 parts by weight of CE-2140, with an epoxy equivalent of 300 g / eq and a weight average molecular weight of 30,000 g / mol; the hardening and lubricating agent is 3 parts by weight of epoxidized soybean oil, the transparent brightening agent is 1 part by weight of transparent extender B, and the antioxidants are 0.1 parts by weight of 1076, 0.1 parts by weight of antioxidant 626, and 0.1 parts of antioxidant DSTDP.

[0077] The preparation method of the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition involved in this embodiment comprises the following steps:

[0078] (1) The above-mentioned anti-hydrolysis agent, chain extender, hardening and lubricating agent, transparent brightening agent, and antioxidant are homogenized and stirred at 1000 rpm / min for 5 minutes in a high-speed disperser equipped with cooling, and then pressed into granules by hot surface molding at a speed of 50 rpm / min to prepare a granular compound auxiliary agent;

[0079] (2) Polybutylene succinate, poly(lactide-glycol), polylactic acid and granular compounding additives are uniformly mixed and added into a twin-screw extruder at temperatures of 150°C, 160°C, 170°C, 180°C, 190°C, 190°C, 190°C, 190°C, 190°C, 190°C, 185°C, 175°C, 170°C, 170°C and 170°C, respectively; the main engine speed is 250rpm / min, and the feed rate is 250rpm / min; the extruded material strips are conveyed by a crawler belt, and a cooling fan is installed above the crawler belt for cooling, forming and pelletizing, and the granular material is ready for forming and processing. Add the granular material into the injection molding machine with an aspect ratio of 33. The temperatures of the first to fifth zones are 180℃, 190℃, 195℃, 195℃, and 195℃ respectively. The storage time is 10s, the injection pressure is 120MPa, the back pressure is 12MPa, the cooling time is 50s, the mold temperature is hot water at 100℃, cold water at 15℃, and the interval between hot and cold water is 5s.

[0080] Comparative Example 1

[0081] This control example can be modified as follows: compared with Example 2, except that cold water at 15°C, hot water insulation for 10s, and cold water for 20s are not used, the rest is the same as Example 2.

[0082] Comparative Example 2

[0083] This comparative example can be modified as follows: compared with Example 3, except that the anti-hydrolysis agent and the chain extender are not used, the rest is the same as Example 3.

[0084] Comparative Example 3

[0085] This comparative example can be modified as follows: compared with Example 5, except that the transparent brightener is not used, the rest is the same as Example 5.

[0086] Comparative Example 4

[0087] Compared with Example 5, during extrusion by the twin-screw extruder, the temperatures are 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, 235°C, and 235°C, respectively; and the temperatures from the first zone to the fifth zone of the external injection molding machine are 235°C, 235°C, 235°C, 235°C, 235°C, and 235°C, respectively. The rest is the same as Example 5.

[0088] Test example

[0089] (1) Transparency

[0090] Test method: Method A in GB / T 2410-2008 “Determination of light transmittance and haze of transparent plastics”, test sample thickness 0.8mm, 50mm×50mm square piece, 5 samples for each composition.

[0091] (2) Wear resistance

[0092] Test method GB / T 5478-2008 "Plastic rolling wear test method" test sample 100mm round piece, 0.8mm thickness, grinding wheel CS10, load 4.9N, rolling number 100 turns, each composition tested 5 samples; then test the sample transmittance, the transmittance indicates the wear resistance of the sample. After the wear test, the surface of the product is scratched and atomized to varying degrees, and the transmittance will be reduced at this time. Indicating the wear resistance with the transmittance after friction can better highlight the innovation of the invention.

[0093] (3) Tensile properties

[0094] The tensile properties of the samples were tested according to GB / T 16421-1996, and 5 specimens were tested for each composition.

[0095] (4) Notched impact performance

[0096] The notched impact properties of the samples were tested according to GB / T 1043-2008, and 5 specimens were tested for each composition.

[0097] (5) Heat resistance test

[0098] Since the actual thickness of biodegradable products is relatively low, in order to make the heat resistance test more suitable for actual use scenarios, improvements were made on the basis of GB / T1634-2004. Five test specimens of 80mm×40mm×1mm were made, with a weight of 100g, a specified deformation of 2mm, and a heating rate of 120℃ / h. During the heating process, the temperature at which the deformation of each sample was 2mm was recorded. This method can more realistically and intuitively reflect the heat resistance of the material.

[0099] The performance table of the embodiments and comparative examples is shown in Table 2; it can be seen from Table 2 that the transparent wear-resistant and heat-resistant, high-strength and high-toughness degradable polyester material provided by the present invention can significantly improve the light transmittance and wear resistance of the composition while taking into account excellent strength and toughness by adding compounding additives and controlling the process. Among them, the performance of the composition in the embodiment 3 and comparative example 2; the performance of the composition in the embodiment 5 and embodiment 6 and comparative example 3 is better than that of the comparative example, and the performance is obtained based on the composition ratio, the additives and the molding processing technology embodied in the invention.

[0100] Table 2 Test results

[0101]

[0102] In summary, the products prepared by the degradable polyester composition of the present invention have excellent comprehensive properties of transparency, wear resistance and heat resistance, which solves the problems of opacity, poor wear resistance, insufficient toughness, good single performance but poor comprehensive performance of the degradable polyester material products on the market; the light transmittance of the degradable polyester composition is as high as 95%, and the light transmittance after the wear resistance test is also above 90%, and the notched impact strength is 10KJ / m 2 above.

[0103] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0104] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition, characterized in that: The raw materials include the following parts by weight: 100 parts of degradable polyester, 0.5-1 parts of anti-hydrolysis agent, 0.5-2 parts of chain extender, 1-3 parts of hardening and lubricating agent, 0.5-2 parts of transparent brightener and 0.1-0.3 parts of antioxidant; The degradable polyester comprises the following components in parts by weight: 0-100 parts of polylactic acid, 0-100 parts of poly(lactide-glycol), 0-100 parts of poly(butylene succinate), 0-100 parts of poly(butylene terephthalate-adipate), and 0-100 parts of poly(glycolic acid); The melt index of the polylactic acid at 230°C and a load of 2.16kg is 10-100g / 10min, and the water content is less than 100ppm; the melt index of the poly(lactide-glycol) at 190°C and a load of 2.16kg is 10-50g / 10min, the viscosity is 0.5-5mPa.s, and the water content is less than 100ppm; the melt index of the poly(butylene succinate) at 190°C and a load of 2.16kg is 5-50g / 10min, and the water content is less than 100ppm; The melt index of the polybutylene terephthalate-adipate at 190° C. and a load of 2.16 kg is 2-30 g / 10 min, and the water content is less than 100 ppm; the melt index of the polyglycolic acid at 230° C. and a load of 2.16 kg is 10-100 g / 10 min, and the water content is less than 100 ppm; The transparent brightener comprises at least one of glycolic acid-lactic acid copolymer and glycolic acid-caprolactone copolymer; The molecular formula of the glycolic acid-lactic acid copolymer is The weight average molecular weight is 10000-20000; The glycolic acid caprolactone copolymer The weight average molecular weight is 10,000-20,000.

2. The transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition according to claim 1, characterized in that: The degradable polyester comprises the following components in parts by weight: 50-60 parts of polylactic acid, 20-50 parts of poly(lactide-glycol), 20-40 parts of poly(butylene succinate), 10-40 parts of poly(butylene terephthalate-adipate), and 50-70 parts of poly(glycolic acid); The melt index of the polylactic acid at 230°C and a load of 2.16kg is 15-50g / 10min, and the moisture content is less than 100ppm; the melt index of the polylactide at 190°C and a load of 2.16kg is 10-20g / 10min, the viscosity is 1.0-2.0mPa.s, and the moisture content is less than 100ppm; the melt index of the polybutylene succinate at 190°C and a load of 2.16kg is 10-25g / 10min, and the moisture content is less than 100ppm; the melt index of the polybutylene terephthalate-adipate at 190°C and a load of 2.16kg is 2-10g / 10min, and the moisture content is less than 100ppm; the melt index of the polyglycolic acid at 230°C and a load of 2.16kg is 20-50g / 10min, and the moisture content is less than 100ppm.

3. The transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition according to claim 1, characterized in that: The anti-hydrolysis agent comprises at least one of 2-oxazoline, 3-oxazoline, 4-oxazoline, phenyl glycidyl ether, triglycidyl isocyanate, bisphenol A diglycidyl ether, tetra(phenyl glycidyl ether) ethane, trimethoxy [3-(glycidyl ether) propyl] silane, triethyl phosphate, tributyl phosphate and triisopropyl phosphate; and / or the chain extender comprises at least one of BASF ADR-4400, ADR-4370F, ADR-4468, and CE-2140; the chain extender has an epoxy equivalent of 200-400 g / eq and a weight average molecular weight of 3000-50000 g / mol; And / or the hardening and lubricating agent includes at least one of wax powder, ethylene bis stearamide, edible white oil, epoxy soybean oil, silicone powder, PTFE powder, molybdenum disulfide, and polysiloxane; And / or the antioxidant includes at least one of BASF Irganox 1010, 1035, 245, 1076, 1098, 1330, 1726, 565, 168, 626, DSTDP, DLTP, 412S, and PEP-36.

4. The transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition according to claim 3, characterized in that: The chain extender has an epoxy equivalent of 220-300 g / eq and a weight average molecular weight of 5000-30000 g / mol.

5. A method for preparing a transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition according to any one of claims 1 to 3, characterized in that: The steps include: (1) fully dispersing an anti-hydrolysis agent, a chain extender, a hardening and lubricating agent, a transparent brightening agent, and an antioxidant to form granules to obtain a granular compounding auxiliary agent; (2) Extruding the degradable polyester and the granular compounding auxiliary agent in an extruder to obtain material strips; pelletizing the material strips to obtain granular materials; extruding the granular materials in an injection molding machine, and cooling them by alternating hot and cold processes to obtain plastic products.

6. The method for preparing the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition according to claim 5, characterized in that: In step (1), the dispersion speed is 1000-1500 rpm / min, and the dispersion time is 5-10 min; hot surface molding is used to form particles to obtain a particle-shaped compound auxiliary agent.

7. The method for preparing the transparent wear-resistant, heat-resistant and high-toughness degradable polyester composition according to claim 5, characterized in that: In step (2), the extruder is provided with a gradient temperature of a front low temperature, a middle high temperature and a rear low temperature, and the gradient temperature is 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, 150-235°C, the main engine speed is 200-250rpm / min, and the feeding amount is 220-300rpm / min; the material strips are pelletized by at least one of air-cooled pelletizing, water-cooled pelletizing, underwater pelletizing and film surface hot cutting; In step (2), the injection molding machine is a single screw injection molding machine, with an aspect ratio of 20-33, a clamping force of 1000KN, a clamping force of 1000KN, a maximum mold opening stroke of 500mm, an ejection stroke of 150mm, and a gradient temperature of low temperature in the front section and high temperature in the middle section of the injection molding machine, and the gradient temperatures are 180-235°C, 180-235°C, 180-235°C, 180-235°C, 180-235°C, and 180-235°C respectively; the storage time is 10-15s, the injection pressure is 90-120MPa, and the back pressure is 8-12MPa; In step (2), the total cooling time by alternating hot and cold is 10-50s, the time interval of alternating hot and cold is 3-6s, and the mold temperature is 50-100°C.

8. Application of a transparent, wear-resistant, heat-resistant, high-strength and tough degradable polyester composition, characterized in that: The transparent, wear-resistant, heat-resistant and high-toughness degradable polyester composition according to any one of claims 1 to 4 is used to prepare a plastic product by injection molding, and / or blow molding, and / or extrusion.

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