CN112063036A

CN112063036A - Protein filler composite EVA (ethylene-vinyl acetate copolymer) foamed shoe material and preparation method thereof

Info

Publication number: CN112063036A
Application number: CN202011006841.5A
Authority: CN
Inventors: 刘显奎; 刘海腾; 孙芳朵; 庞晓燕
Original assignee: China Leather and Footwear Research Institute Co Ltd
Current assignee: China Leather and Footwear Research Institute Co Ltd
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2020-12-11

Abstract

A protein filler compounded EVA foaming shoe material and a preparation method thereof are disclosed, the foaming shoe material comprises the following components: based on 100 parts by weight of the EVA, the EVA adhesive comprises the following other ingredients in parts by weight: 1-30 parts of protein powder filler; 3-7 parts of foaming agent; 20-30 parts of inorganic powder filler; the weight of the compatibilizer accounts for 1 to 2 percent of the total amount of the shoe material; 0.5-0.9 of cross-linking agent; 0.5-15 parts of plasticizer; 3-16 parts of auxiliary agent. The preparation method comprises the following process flows: drying the protein powder filler, plasticizing the protein powder filler, plasticating, pulling a piece, and carrying out die pressing and foaming. The invention has the advantages that: the protein powder filler produced by using waste leather scraps as a raw material is compounded with EVA, and the prepared material for the foamed shoes has certain moisture absorption. Can replace the traditional shoe material EVA material, and solves the problem of the protein filler produced by using waste leather scraps as raw materials. No waste is discharged in the production process, the process operation is simple and easy, and the product cost is lower than that of the common EVA foaming material.

Description

Protein filler composite EVA (ethylene-vinyl acetate copolymer) foamed shoe material and preparation method thereof

Technical Field

The invention relates to a protein filler composite EVA (ethylene-vinyl acetate copolymer) foamed shoe material and a preparation method thereof, belonging to the field of new materials.

Background

EVA (ethylene-vinyl acetate polymer) material is the main variety of shoe making material in China, and the usage amount of the EVA material accounts for more than 35% of the sole material. EVA is a random copolymer mainly obtained by polymerizing ethylene (CH2 ═ CH2) monomer and vinyl acetate (CH3COOCH ═ CH2) monomer. The EVA foaming material for the shoe material is subjected to various composite treatments, has the advantages of lightness, good elasticity, good flexibility, difficult wrinkle, excellent colorability, suitability for various climates and the like, is widely applied, but is easy to cause white pollution to threaten the environment due to poor hygroscopicity and no degradation; meanwhile, when the insole is used as an insole, the insole is easy to cause moisture and odor in the shoe cavity.

A great amount of chromium-containing leather scraps are generated in the production process of the tanning industry, and the preparation of the protein filler by using the chromium-containing leather scraps is a main treatment mode of the industry at present. However, the waste leather scrap protein filling material contains a trace amount of chromium, still belongs to dangerous waste according to national regulations, cannot be used for adding in any food industry and feed industry, and has a serious problem in marketing. The invention relates to a method for producing foaming shoe materials by using albumen powder filler composite EVA produced by waste leather scraps, which not only helps leather-making enterprises to solve the problem of waste leather scrap treatment, but also can produce albumen powder filler composite EVA foaming materials which have degradability, completely reach the level of common EVA in physical properties, have better partial indexes, have good moisture absorption and moisture removal and can be applied to the shoe-making industry.

Disclosure of Invention

The invention aims to provide a preparation method of an albumen powder filler composite EVA foaming shoe material, which aims to solve the problems of no moisture absorption and difficult degradation of the existing EVA foaming material for the shoe material and find a new way for utilizing albumen powder filler produced by using chromium-containing waste leather scraps produced by tanning enterprises as raw materials.

The technical scheme of the invention is as follows:

a foaming shoe material compounded by protein filler and EVA is characterized by comprising the following components: based on 100 parts by weight of the EVA, the EVA adhesive comprises the following other ingredients in parts by weight: 1-30 parts of protein powder filler; 3-7 parts of foaming agent; 20-30 parts of inorganic powder filler; 2-3% of a compatibilizer; 0.5-0.9 of cross-linking agent; 0.5-15 parts of plasticizer; 3-16 parts of auxiliary agent.

The protein powder filler is produced by using chromium-containing waste leather scraps as a raw material, the particle size is 60-300 meshes, and the water content is lower than 3%.

The foaming agent is one or a mixture of two of azodicarbonamide and AD300 in any proportion.

The inorganic powder is one or a mixture of two of talcum powder and kaolin in any proportion.

The compatibilizer is one, two or three of maleic anhydride grafted EVA, acrylic polymer EAA and maleic anhydride grafted ethylene propylene diene monomer in any proportion.

The cross-linking agent is dicumyl peroxide.

The plasticizer is one or a mixture of two of glycerol and a silane coupling agent.

The auxiliary agent comprises urea, zinc oxide and zinc stearate, wherein the zinc oxide accounts for 1-8.0% of the total amount of the shoe material, and the zinc stearate accounts for 1-5.5% of the total amount of the shoe material.

The preparation method of the protein powder composite EVA foaming material is characterized by comprising the following steps:

(1) drying the protein powder filler: drying the protein powder filler until the water content is lower than 3%;

(2) plasticizing of the protein powder filler: putting the dried protein powder filler into a high-speed stirrer, adding a plasticizer, and stirring at a high speed for 6-10min to obtain a plasticized protein filler;

(3) plasticating: the method comprises the following steps:

(a) primary banburying: adding EVA, POE and EPDM into an internal mixer, and banburying for 2-6min at 115 deg.C;

(b) secondary banburying: adding compatibilizer and banburying for 2-4 min;

(c) carrying out three-time banburying: then adding the plasticized protein filler in the step (2), and banburying for 3-7 min;

(d) four times of banburying: adding urea, zinc oxide, zinc stearate and azodicarbonamide, and banburying for 2-6 min;

(e) five times of banburying: adding dicumyl peroxide and inorganic filler and continuously banburying for 2-4 min;

(4) pulling a piece: transferring all the plasticated materials to an open mill to mill the sheet into sheets, and cutting the sheets into small pieces or granulating;

(5) and (3) mould pressing foaming: and (3) carrying out compression foaming on the small pieces or the granular materials obtained in the last step on a flat vulcanizing machine, and decompressing to obtain the protein powder composite EVA foaming material.

In the step (1), the protein powder filler is put into an oven to be dried for 3-9h at the temperature of 105 ℃; in the step (5), the foaming temperature is 170 ℃, the pressure is 10MPa, and the time is 400 s.

The invention has the advantages that: the foaming shoe material prepared by protein powder filler produced by using waste leather scraps as raw materials and EVA (ethylene-vinyl acetate copolymer) has certain moisture absorption. Can replace the traditional shoe material EVA material, and solves the problem of the protein filler produced by using waste leather scraps as raw materials. No waste is discharged in the production process, the process operation is simple and easy, and the product cost is lower than that of the common EVA foaming material.

The physical indexes of the material can be completely compared with those of the common EVA shoe material, the cushioning property is better, and the material is particularly suitable forThe density of the material is lower and can reach 0.11g/cm³Can still be used normally.

After soaking for 6 hours, the water absorption rate can reach 12-18.0% of the self weight; under the conditions of room temperature 23 ℃ and relative humidity 50%, more than 80% of the absorbed water can be lost in about 6 hours.

The degradability of the traditional EVA foaming material is improved, and in a soil burying method test, a sample is buried in soil with humus, and the degradation weight loss rate of 30 days can reach 5%.

Drawings

FIG. 1 is a flow chart of the manufacturing process of the shoe material of the present invention.

Detailed Description

An embodiment of the present invention will be described in detail with reference to fig. 1 and specific examples, but those skilled in the art will understand that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

The method for preparing the foaming shoe material by compounding the protein powder filler with the EVA comprises the following components in percentage by weight:

EVA 100 weight portions

Protein powder filler: 1-30 parts, preferably: 5-15 parts;

urea: 1.0-2.5 parts, preferably: 2.0-2.5 parts;

1.0-8.0 parts of zinc oxide, preferably: 4.0-6.0 parts;

zinc stearate: 1.0-5.5 parts, preferably: 4.0-5.0 parts;

blowing agent Azodicarbonamide (AC): 3.0-7.0 parts, preferably: 3.5-6.0 parts;

talc powder: 10.0-12.0 parts, preferably: 10.5-11.5 parts;

kaolin: 10.0-12.0 parts, preferably: 5.5-7.5 parts;

1-2 parts of total consumption of compatibilizer maleic anhydride grafted EVA, acrylic polymer EAA and maleic anhydride grafted ethylene propylene diene monomer rubber, preferably 1.5 parts

Crosslinking agent dicumyl peroxide (DCP): 0.5-0.9 part, preferably: 0.6 to 0.8 portion.

The total amount of the plasticizer, the silane coupling agent and the glycerin is 0.5-15 parts, preferably 5-10 parts.

The EVA is made of EVA resin material commonly used for foaming shoe material.

The protein powder filler is mainly produced by using chromium-containing waste leather scraps as a raw material, the particle size is 80-200 meshes, and the water content is lower than 3%. Other protein powders may also be used for the application purposes of the present invention.

The material for the absorbable, dehumidified and biodegradable shoes, which is prepared by the invention, is an environment-friendly material, is very suitable for being used as a material for inner cavities of the shoes, and is not only beneficial to sanitation of the inner cavities of the shoes but also beneficial to environmental protection.

The EVA material is 100 parts by weight, the protein powder filler is added in 1-30 parts, preferably 5-15 parts, the proportion can enable the physical properties of the protein filler and the EVA composite foaming shoe material to reach the best, the appearance color is light, the color change is not influenced, meanwhile, the EVA composite foaming shoe material has excellent moisture absorption and moisture removal performance, the cost can be reduced to the maximum extent, the use amount exceeds 15%, the product has a larger foaming multiplying power, the prepared shoe material has seriously reduced strength, but the EVA composite foaming shoe material still has feasibility when being applied to the manufacture of shoe materials such as footbeds and the like.

The compatibilizer used in the invention, maleic anhydride grafted EVA, acrylic polymer EAA, maleic anhydride grafted ethylene propylene diene monomer and the like all have carboxyl similar to the molecular structure of protein, can be used for providing protein powder with good compatibility, simultaneously has nonpolar end groups, has good compatibility with EVA, POE, EPDM and the like, can play a role in increasing the capacity of a bridge, and the total dosage is 1-2%.

The implementation process comprises the following steps:

1. processing of protein powder filler: and (3) putting the protein powder filler into an oven, and drying at 105 ℃ for 6h to obtain protein powder with the water content of less than 3%.

2. Plasticizing of the protein powder filler: and (3) placing the dried protein powder filler into a high-speed stirrer, adding a plasticizer, and stirring at a high speed for 8 min.

3. The plastication process method comprises the following steps: adding EVA, POE and EPDM into an internal mixer, internally mixing for 4min at 115 ℃, adding a compatibilizer for internally mixing for 3min, then adding the plasticized protein filler in 2, internally mixing for 5min, observing that the mixture is basically uniform, adding a neutralization auxiliary agent urea, an auxiliary agent zinc oxide, zinc stearate and a foaming agent Azodicarbonamide (AC), continuously internally mixing for 4min, then adding a crosslinking agent dicumyl peroxide (DCP) and an inorganic filler, continuously internally mixing for 3min, and completely transferring the discharged materials to an open mill for opening the zipper tabs. And cutting the sheet into small pieces or granulating, and performing compression foaming on the small pieces or the granules on a flat vulcanizing machine under the conditions of 400s of time, 170 ℃ of temperature and 10MPa of pressure, so as to obtain the protein powder filler and EVA composite foaming shoe material after decompression.

Example 1:

the first step of processing protein powder filler: and (3) putting the protein powder filler into an oven, drying at 105 ℃ for 6h to obtain protein powder with the water content of less than 3%, and weighing.

And plasticizing the protein powder filler in the second step: 80g of dried protein powder filler is put into a high-speed stirrer, 0.3g of plasticizer titanate coupling agent and 20g of glycerol are added, and the mixture is stirred at high speed for 8 min.

Thirdly, adding EVA180g, POE10g and EPDM40g into an internal mixer, internally mixing for 4min at 115 ℃, adding a compatibilizer EAA3g, internally mixing for 3min, then adding 50g of the plasticized protein filler in the second step, internally mixing for 5min, after observing that the mixture is basically uniform, adding 5g of a neutralization auxiliary agent urea, 4g of auxiliary agent zinc oxide, 4g of zinc stearate and 10g of a foaming agent Azodicarbonamide (AC), continuously internally mixing for 4min, adding 20g of an inorganic filler talcum powder, continuously internally mixing for 3min, then adding 1.7g of a crosslinking agent dicumyl peroxide (DCP), and completely transferring to an open mill for pulling the zipper after internally mixing for 2 min.

And fourthly, cutting the sheet into small pieces, and carrying out die pressing foaming on the small pieces in a flat vulcanizing machine under the die pressing condition that the time is 400s, the temperature is 170 ℃, the pressure is 10MPa, and then obtaining the protein powder filler and EVA composite foaming shoe material after pressure reduction.

The measured physical index is shown in Table 1 below.

TABLE 1 measurement results of protein powder compounded EVA foamed shoe material

Example 2:

firstly, processing protein powder filler: and (3) putting the protein powder filler into an oven, drying at 105 ℃ for 6h to obtain protein powder with the water content of less than 3%, and weighing.

Secondly, plasticizing of the protein powder filler: 80g of dried protein powder filler is put into a high-speed stirrer, 0.8g of plasticizer titanate coupling agent is added, and the mixture is stirred at high speed for 8 min.

Thirdly, adding EVA180g, POE10g and EPDM40g into an internal mixer, internally mixing for 4min at 115 ℃, adding a compatibilizer maleic anhydride grafted EVA4g, internally mixing for 3min, then adding 60g of plasticized protein filler in the second step, internally mixing for 5min, observing that the mixing is basically uniform, adding 5g of a neutralization aid urea, 4g of an aid zinc oxide, 4g of zinc stearate and 12g of a foaming agent Azodicarbonamide (AC), continuously internally mixing for 4min, adding 20g of an inorganic filler talcum powder, continuously internally mixing for 3min, then adding 1.9g of a crosslinking agent dicumyl peroxide (DCP), and completely transferring to an open mill to mill the zipper after internally mixing for 2 min.

The measured physical index is shown in Table 2 below.

TABLE 2 measurement results of protein powder compounded EVA foamed shoe material

Example 3:

Secondly, plasticizing of the protein powder filler: 80g of dried protein powder filler is put into a high-speed stirrer, 0.5g of plasticizer titanate coupling agent and 10g of glycerol are added, and the mixture is stirred at high speed for 8 min.

And thirdly, adding EVA190g and EPDM40g into an internal mixer, internally mixing for 4min at 115 ℃, adding a compatibilizer maleic anhydride grafted EPDM2g, internally mixing for 3min, then adding 60g of plasticized protein filler in the second step, internally mixing for 5min, observing that the refining is basically uniform, adding 5g of a neutralization auxiliary agent urea, 4g of auxiliary agent zinc oxide, 4g of zinc stearate and 11g of foaming agent Azodicarbonamide (AC), continuously internally mixing for 4min, adding 1.7g of cross-linking agent dicumyl peroxide (DCP) and 10g of inorganic filler talcum powder, and completely transferring to an open mill to open the zipper after the materials are discharged for 2 min.

The measured physical properties are shown in Table 3 below.

TABLE 3 measurement results of protein powder compounded EVA foamed shoe material

Claims

1. A foaming shoe material compounded by protein filler and EVA is characterized by comprising the following components: based on 100 parts by weight of the EVA, the EVA adhesive comprises the following other ingredients in parts by weight: 1-30 parts of protein powder filler; 3-7 parts of foaming agent; 20-30 parts of inorganic powder filler; 2-3% of a compatibilizer; 0.5-0.9 of cross-linking agent; 0.5-15 parts of plasticizer; 3-16 parts of auxiliary agent.

2. The protein powder composite EVA foaming material of claim 1, wherein the protein powder filler is produced by using chromium-containing waste leather scraps as a raw material, the particle size is 60-300 meshes, and the water content is lower than 3%.

3. The albumen powder composite EVA foaming material of claim 1, wherein the foaming agent is one or a mixture of two of azodicarbonamide and AD300 in any proportion.

4. The protein powder composite EVA foaming material of claim 1, wherein the inorganic powder is one or a mixture of talc powder and kaolin in any proportion.

5. The albumen powder composite EVA foaming material of claim 1, wherein the compatibilizer is a mixture of one, two or three of maleic anhydride grafted EVA, acrylic acid polymer EAA and maleic anhydride grafted ethylene propylene diene monomer at any proportion.

6. The protein powder compounded EVA foaming material of claim 1, wherein the crosslinking agent is dicumyl peroxide.

7. The albumen powder composite EVA foaming material of claim 1, wherein the plasticizer is one or a mixture of two of glycerol and a silane coupling agent.

8. The albumen powder composite EVA foaming material of claim 1, wherein the auxiliary agent comprises urea, zinc oxide and zinc stearate, wherein the zinc oxide accounts for 1-8.0% of the total amount of the shoe material, and the zinc stearate accounts for 1-5.5% of the total amount of the shoe material.

9. The preparation method of the protein powder composite EVA foaming material of claim 1, which is characterized by comprising the following steps:

(3) plasticating: the method comprises the following steps:

(b) secondary banburying: adding compatibilizer and banburying for 2-4 min;

10. The preparation method according to claim 9, wherein in the step (1), the protein powder filler is dried in an oven at 105 ℃ for 3-9 h; in the step (5), the foaming temperature is 170 ℃, the pressure is 10MPa, and the time is 400 s.