Polyether block amide-based composition and method for producing sole from composition

Abstract

The present application relates to a polyether block amide-based composition and a method for producing a sole from the composition. The composition comprises: 90-95 wt% of component A: polyether block amide resin; and 5-10 wt% of component B: a styrene copolymer, stearic acid, zinc stearate, and calcium carbonate. The present invention successfully provides a composition based on a thermoplastic elastomer material. By adding a small amount of component B, the composition is prepared into plastic granules. The plastic granules can withstand high temperature and high pressure, so that pores are more uniformly distributed in a created polymer material to achieve better foamability and elasticity, so that the composition is highly suitable for sole production. The sole exhibits comfortable feeling while ensuring inherent properties, such as skid resistance and wear resistance of rubber outsoles. The maximum elasticity of a traditional foaming process can only reach 60%, whereas the present application provides a modified process in which a material is foamed and dried, creating higher elasticity for the sole, so that the maximum elasticity can reach 85%.

Description

Composition based on block polyetheramide and method for producing shoe soles from the composition TECHNICAL FIELD

[0001] The present invention relates to the technical field of shoe materials, in particular to a composition based on block polyetheramide and a method for producing shoe soles from the composition. BACKGROUND

[0002] Shoes are articles that protect, smooth and beautify the feet while performing various activities. The design of shoes is extremely diverse and rich according to the era, culture and purpose of use. Modern footwear varies greatly in terms of use, style and cost. Simple sandals can be very thin and consist of only a strap, while modern fashion shoes can be made of very expensive materials and have a complex structure. Traditionally, shoes are made of materials such as leather, wood and fabric, but shoe materials are increasingly made of rubber, plastic and other petrochemical materials.

[0003] One of the most important components of a shoe is the sole. The sole, also known as the outsole, is the bottom part of the shoe that comes into direct contact with the ground during movement, and therefore "lives" a very fast decline during use. The sole is made of many different materials depending on the style and purpose of the shoe. The materials are very diverse, including, for example: natural rubber, vulcanized rubber, leather, polyurethane (PU), ethylene vinyl acetate (EVA), block polyetheramide (PEBA), etc.

[0004] Thermoplastic block polyetheramide resin is a common material in shoe sole production, which is a copolymer obtained by polymerization of (low) polyamide and alcohol-based polyether. It is soft in texture and has high impact resistance at low temperature, and its absorption and conversion capacity is much greater than that of other materials. However, its viscosity mainly depends on humidity, temperature and storage time, and the melting point is relatively low, which is not conducive to 22-28 MPa, 150℃ conditions, resulting in a larger foaming density that cannot be uniformly distributed inside the high molecular material, affecting the quality of the shoe material.

[0005] SUMMARY

[0006] In view of the deficiencies in the prior art, the present invention proposes a composition based on thermoplastic block polyetheramide resin. Compared with pure thermoplastic block polyetheramide resin material, this composition can withstand high temperature and pressure, so that the holes are more uniformly distributed in the created polymer material, resulting in better foaming and elasticity, which is very suitable for producing shoe soles.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions:

[0008] A composition based on block polyetheramide, comprising:

[0009] 90-95wt% of component A: block polyetheramide resin; and

[0010] 5-10 wt% of component B: styrene copolymer, stearic acid, zinc stearate, calcium carbonate;

[0011] The styrene copolymer is made of the following raw materials in parts by weight:

[0012] a) 30-50 parts of styrene-isoprene block copolymer;

[0013] b) 10-20 parts of mercaptopropionic acid grafted on the styrene-isoprene block copolymer of a);

[0014] c) 10-30 parts of hydroxyethyl methacrylate esterified with b) mercaptopropionic acid;

[0015] d) 15-40 parts of polymerizable benzotriazole radically polymerized with c) hydroxyethyl methacrylate;

[0016] and 0.1-1 parts of antioxidant, 0.1-1 parts of catalyst, 0.2-0.5 parts of initiator.

[0017] Polyether block amide resin is a relatively common material in the production of shoe soles, and its commercialization is very mature, which can be directly obtained from the market and directly used. In some specific solutions of the present case, the resin can be but not limited to: purchased from Arkema suppliers, such as 4533 SP 01, 2533 SA 01, 7033, 3533, etc.; also can be purchased from Germany Wanhua, such as E51-S3, E47-S3, E40-S1; and Japan Toray CM3004G-20, Wanhua 4011, etc.

[0018] In some other solutions, the plastic has a density of about 1.01 kg / m 3 In some other solutions, the resin has a melting point of about 147°C. In some other solutions, the resin has a softening point of about 111°C. In yet other solutions, the resin has a water absorption rate of about 0.4% at room temperature.

[0019] The "softening point" or softening temperature is the temperature at which the polymer (plastic) begins to soften. The remaining parameters are generally common in the art, and therefore it is not necessary and the detailed description is omitted to simplify and facilitate understanding of the present application.

[0020] In another scheme, the amount of each raw material of component B is 20-50 parts by weight of styrene copolymer, 1-3 parts of stearic acid, 1-3 parts of zinc stearate, and 2-4 parts of calcium carbonate; the preparation process is as follows: the formula amount of stearic acid, zinc stearate and calcium carbonate is ground and uniformly dispersed with a high-speed disperser to obtain a mixture, the styrene polymer is melted and added to the mixture, and then extruded and granulated to obtain the product.

[0021] Stearic acid exists in the composition of the present application, and its main function is as a thickening agent and an antioxidant. Zinc stearate is a zinc metal salt of stearic acid, which is used as a lubricant and a release agent for plastics. At the same time, it also plays the role of a vulcanization and softening active agent.

[0022] The presence of nano calcium carbonate in the composition of the present application can improve the rheological properties of the final plastic particles and improve their formability. This substance also acts as a plastic filler, has the effects of hardening and reinforcing, improves the bending strength, bending elastic modulus, heat distortion temperature and dimensional stability of the plastic, and at the same time makes the plastic have thermal hysteresis.

[0023] The styrene copolymer in the composition of the present application is prepared by the following preparation method:

[0024] In a reaction kettle, styrene-isoprene block copolymer, mercaptopropionic acid, antioxidant, dimethyl sulfoxide as solvent are added, heated to 150℃ and reacted overnight, then cooled to 90-110℃, catalyst and hydroxyethyl methacrylate are added, and reacted overnight, and then the low boiling point substances are removed by vacuum distillation; re-add dimethyl sulfoxide as solvent, blow in nitrogen for 30 min, then add polymerizable benzotriazole and initiator, heat to 70℃ under nitrogen protection, and stir for 3-6 h; after the reaction is completed, the low boiling point substances are removed, and the product is dried to obtain the product.

[0025] The styrene-isoprene block copolymer has solubility, thermoplasticity, elasticity, toughness like rubber, and good processing fluidity, the polyisoprene in the copolymer has a large chain entanglement space, and has good compatibility with the above-mentioned stearic acid, zinc stearate and calcium carbonate; at the same time, due to the double bond in the chain segment, it can undergo click reaction with mercaptopropionic acid to introduce carboxyl group, and then undergo esterification reaction to further introduce polymerizable double bond, and polymerize with polymerizable benzotriazole, thereby forming polymer branches under the main chain of the styrene-isoprene block copolymer, further improving the compatibility with the above-mentioned additives, and effectively reducing the shrinkage of the finished product, having excellent thermal stability and processing performance; the mechanical properties are also further improved, having good strength and good wear resistance; in addition, the introduced polymerizable benzotriazole can also bring good ultraviolet resistance to the material and improve the yellowing resistance of the material.

[0026] In another aspect, the styrene-isoprene block copolymer has a molecular weight of 2000-10000.

[0027] In another aspect, the polymerizable benzotriazole is 2-(2'-propionyloxy-5'-methylphenyl) benzotriazole; the antioxidant is triphenyl phosphite; the catalyst is tetrabutylammonium bromide; and the initiator is azobisisobutyronitrile.

[0028] In another aspect, the present application provides a method for producing a shoe sole, which comprises the composition according to the above aspect.

[0029] According to another aspect, the method for producing a shoe sole comprises the following steps:

[0030] S1, mixing component A and component B in the composition, and then extruding into a cylindrical plastic strip through a double-screw circular plastic filament device, and cutting into plastic particles of 2-3 mm;

[0031] S2, melting the plastic particles to form a shoe sole embryo, and then foaming to a size of 1.7 to 1.9 times the original size to make a shoe sole preform;

[0032] S3, drying the shoe sole preform, which continues to foam and expand, and finally makes the shoe sole preform foam to 2.0-2.4 times the original size, to obtain a finished shoe sole.

[0033] According to another aspect, the foaming is carried out under the following conditions:

[0034] The foaming medium is a nitrogen atmosphere; the temperature range is 110-170℃; the foaming pressure range is 20-50Mpa; and the pressure holding time range is 60-240min;

[0035] The drying is carried out under the following conditions:

[0036] The drying temperature range is 120-160℃; the drying pressure range is 0-2Mpa; and the drying time is 20-40min.

[0037] Compared with the prior art, the present application has the following advantages: the present application successfully provides a composition based on a thermoplastic elastomer material Pebax 4533, which is prepared into the form of plastic particles by adding a small amount of component B (styrene copolymer, stearic acid, zinc stearate, calcium carbonate), and the plastic particles can withstand high temperature and high pressure, so that the pores are more uniformly distributed in the created polymer material, resulting in better foaming and elasticity, which is very suitable for the production of shoe soles.

[0038] The method of the present application overcomes the shortcomings and problems of the conventional method, including but not limited to long production time, large amount of direct labor force required on each machine in each stage, low efficiency, etc. Unlike the conventional throttle foaming process, the present application adds component B without additional additives such as foaming agent, and the specific gravity is lighter than the conventional method, so that the shoe sole feels comfortable, while ensuring the solid performance such as the rubber outsole has anti-skid, wear-resistant, etc. In addition, unlike the conventional process, the process of the present application also includes a drying step for the shoe sole embryo, which helps the shoe sole to have better elasticity and smoothness. Specifically, the highest elasticity of the conventional foaming process can only reach 60%, while the process of the present application is improved by foaming and drying the material, thereby creating higher elasticity for the shoe sole, which can reach 85%. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0040] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0041] Embodiment 1: A block polyetheramide-based composition, comprising:

[0042] 90wt% of component A: block polyetheramide resin (PEBA 4533 SP 01); and 4533 SP 01); and

[0043] 10wt% of component B: styrene copolymer, stearic acid, zinc stearate, calcium carbonate;

[0044] Grind 1 part of stearic acid, 1 part of zinc stearate and 2 parts of calcium carbonate, and then uniformly disperse them with a high-speed disperser to obtain a mixture. Then melt 20 parts of styrene polymer and add it to the mixture, and then extrude and granulate to obtain component B.

[0045] The styrene copolymer comprises the following raw materials in parts by weight:

[0046] a) 30 parts of styrene-isoprene block copolymer;

[0047] b) 10 parts of mercaptopropionic acid grafted on the styrene-isoprene block copolymer of a);

[0048] c) 10 parts of hydroxyethyl methacrylate esterified with b) mercaptopropionic acid;

[0049] d) 15 parts of a polymerizable phenylpropyltriazole (2-(2'-propionyloxy-5'- methylphenyl)benzotriazole) free-radically polymerized with the methacrylic acid hydroxyethyl ester of c);

[0050] and 0.1 parts of an antioxidant, 0.1 parts of a catalyst, 0.2 parts of an initiator.

[0051] In a reaction vessel, the styrene-isoprene block copolymer, mercaptopropionic acid, antioxidant are added, dimethyl sulfoxide is added as a solvent, the temperature is raised to 150°C and left to react overnight, then the temperature is lowered to 90-110°C, the catalyst and the methacrylic acid hydroxyethyl ester are added and left to react overnight, the low-boiling substances are removed by distillation under reduced pressure; dimethyl sulfoxide is added again as a solvent, nitrogen is blown in for 30 minutes, then the polymerizable phenylpropyltriazole and the initiator are added, the temperature is raised to 70°C under nitrogen, and left to react with stirring for 3-6 hours; after the reaction is complete, the low-boiling substances are removed, and the product is dried to obtain the product.

[0052] Example 2: A block polyetheramide-based composition, comprising:

[0053] 92 wt% of Component A: a block polyetheramide resin (PEBAX® 4533 SP 01); and 4533 SP 01); and

[0054] 8 wt% of Component B: a styrene copolymer, stearic acid, zinc stearate, calcium carbonate;

[0055] The rest is the same as in Example 1.

[0056] Example 3: A block polyetheramide-based composition, comprising:

[0057] 93.5 wt% of Component A: a block polyetheramide resin (PEBAX® 2533 SA 01); and 2533 SA 01); and

[0058] 1.5 wt% of Component B: a styrene copolymer, stearic acid, zinc stearate, calcium carbonate;

[0059] The rest is the same as in Example 1.

[0060] Example 4: A block polyetheramide-based composition, comprising:

[0061] 95 wt% of Component A: a block polyetheramide resin (E51-S3); and

[0062] 5 wt% of Component B: a styrene copolymer, stearic acid, zinc stearate, calcium carbonate;

[0063] The rest is the same as in Example 1.

[0064] Example 5: A block polyetheramide-based composition, comprising:

[0065] 90 wt% of Component A: block polyether amide resin (PEBA) 4533 SP 01); and

[0066] 10 wt% of Component B: styrene copolymer, stearic acid, zinc stearate, calcium carbonate;

[0067] Grind 3 parts of stearic acid, 3 parts of zinc stearate and 4 parts of calcium carbonate, and then uniformly disperse them with a high-speed disperser to obtain a mixture. Then melt 40 parts of styrene polymer and add them to the mixture, and then extrude and granulate to obtain Component B.

[0068] The rest is the same as Example 1.

[0069] Comparative Example 1:

[0070] 100 wt% of Component A: block polyether amide resin (PEBA) 4533 SP 01).

[0071] Comparative Example 2:

[0072] 90 wt% of Component A: block polyether amide resin (PEBA) 4533 SP 01); and

[0073] 10 wt% of Component B: styrene-isoprene block copolymer, stearic acid, zinc stearate, calcium carbonate;

[0074] Grind 3 parts of stearic acid, 3 parts of zinc stearate and 4 parts of calcium carbonate, and then uniformly disperse them with a high-speed disperser to obtain a mixture. Then melt 40 parts of styrene-isoprene block copolymer and add them to the mixture, and then extrude and granulate to obtain Component B.

[0075] Application:

[0076] The above composition is used to produce a shoe sole, and the method comprises the following steps:

[0077] S1, mixing Component A and Component B in the composition, and then extruding them into a cylindrical plastic strip through a double-screw circular plastic filament device, and cutting them into plastic particles with a size of 2-3 mm;

[0078] S2, melting the plastic particles to form a shoe sole embryo, and then foaming to a size of 1.7 to 1.9 times the original size to make a shoe sole preform;

[0079] S3, drying the shoe sole preform, which continues to foam and expand through drying, and finally makes the shoe sole preform foam to 2.0-2.4 times the original size, to obtain a finished shoe sole.

[0080] The foaming is carried out under the following conditions:

[0081] The foaming medium is nitrogen atmosphere; the temperature range is 110-170℃; the foaming pressure range is 20-50Mpa; the pressure maintaining time range is 60-240min;

[0082] The drying is carried out under the following conditions:

[0083] The drying temperature range is 120-160℃; the drying pressure range is 0-2Mpa; the drying time is 20-40min.

[0084] Among them, the comparative example 1 adds the foaming agent before foaming.

[0085] The foaming density is tested according to GB / T6343-2009;

[0086] The cell diameter is tested according to QB / T5490-2020;

[0087] The resilience is tested according to GB / T6670-2008;

[0088] Table 1

[0089] As can be seen from Table 1, the composition based on block polyether amide and the process for preparing the shoe sole by using the composition provided by the present application have significant progress, the foaming density is reduced from 0.15 in the traditional process to 0.08, the resilience is improved from 60% to 85%, and the foaming property and the elasticity are better, which is very suitable for the production of shoe sole.

[0090] Although the embodiments of the present application have been disclosed as above, it is not limited to the application listed in the specification and the embodiments, and can be fully applied to various fields suitable for the present application, and additional modifications can be easily realized by those skilled in the art, and therefore the present application is not limited to specific details, but is within the general concept defined by the claims and the equivalent scope.

Claims

1. A block polyetheramide-based composition characterized in that, Comprising: 90-95wt% of component A: block polyether amide resin; and 5-10wt% of component B: styrene copolymer, stearic acid, zinc stearate, calcium carbonate; The styrene copolymer is prepared by using the following raw materials in parts by weight: a) 30-50 parts of styrene-isoprene block copolymer; b) 10-20 parts of mercaptopropionic acid grafted on the styrene-isoprene block copolymer of a); c) 10-30 parts of hydroxyethyl methacrylate esterified with the mercaptopropionic acid of b); d) 15-40 parts of polymerizable benzotriazole radical polymerized with the hydroxyethyl methacrylate of c); and 0.1-1 parts of antioxidant, 0.1-1 parts of catalyst, 0.2-0.5 parts of initiator.

2. The block polyetheramide-based composition according to claim 1, characterized in that, The component A satisfies the following characteristics: density 1.01 kg / m 3 The melting temperature was 147°C, the softening point was 111°C and the water absorption at room temperature was 0.4%.

3. The block polyetheramide-based composition according to claim 1, characterized in that, The raw material usage of the component B is 20-50 parts of styrene copolymer, 1-3 parts of stearic acid, 1-3 parts of zinc stearate, and 2-4 parts of calcium carbonate by weight.

4. The block polyetheramide-based composition according to claim 3, characterized in that, The preparation process of the component B is as follows: Grind the formula amount of stearic acid, zinc stearate and calcium carbonate, then uniformly disperse them with a high-speed disperser to obtain a mixture, melt the styrene polymer into the mixture, then extrude and granulate to obtain the component B.

5. The block polyetheramide-based composition according to claim 1, characterized in that, The preparation process of the styrene copolymer is as follows: Add the styrene-isoprene block copolymer, mercaptopropionic acid and antioxidant into a reaction kettle, add dimethyl sulfoxide as solvent, heat to 150°C and react overnight, then cool to 90-110°C, add catalyst and hydroxyethyl methacrylate, react overnight, remove low-boiling substances under reduced pressure; re-add dimethyl sulfoxide as solvent, blow in nitrogen for 30 min, then add polymerizable benzotriazole and initiator, heat to 70°C under nitrogen protection, and stir for 3-6 h; after the reaction is completed, remove the low-boiling substances, and dry the product to obtain the styrene copolymer. The molecular weight of the styrene-isoprene block copolymer is 2000-10000.

6. The block polyetheramide-based composition according to claim 1, characterized in that, The polymerizable benzotriazole is 2-(2'-propionyloxy-5'-methylphenyl) benzotriazole; the antioxidant is triphenyl phosphite; the catalyst is tetrabutylammonium bromide; and the initiator is azobisisobutyronitrile.

7. The block polyetheramide-based composition according to claim 1, characterized in that, The block polyether amide-based composition is prepared by using any one of claims 1-6.

8. A method of producing a shoe sole, characterized by, Comprising the following steps:

9. The method of manufacturing a shoe sole according to claim 8, wherein, S1, mix the component A and the component B in the composition, then extrude into a cylindrical plastic strip through a double-screw circular plastic filament device, and cut into plastic particles of 2-3 mm; S2, melt the plastic particles to form a shoe sole blank, then foam to a size of 1.7 to 1.9 times the original size to make a shoe sole preform; S3, dry the shoe sole preform to obtain a finished shoe sole.

10. The method for producing a shoe sole according to claim 9, wherein The foaming is carried out under the following conditions: The foaming medium is a nitrogen atmosphere; the temperature range is 110-170°C; the foaming pressure range is 20-50 Mpa; and the pressure holding time range is 60-240 min; The drying is carried out under the following conditions: The drying temperature range is 120 to 160°C; the drying pressure range is 0-2 Mpa; and the drying time is 20-40 min. ​

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