A plastic insole material and its application

Abstract

The invention relates to the technical field of materials, and discloses a plastic insole material and an application thereof. The insole material is made of ethylene-vinyl acetate copolymer as a base material, thermoplastic elastomer, wear-resistant filler and antibacterial modified material as auxiliary materials, and is made through a mixing and hot-pressing foaming process, wherein the wear-resistant filler is sisal fiber with nano zirconium oxide loaded on the surface, so as to improve the wear resistance of the insole material. The plastic sheet can be shaped according to the foot shape of each person, and can meet the requirements of different arch heights. According to the actual conditions of users at different orthopedic stages, insoles suitable for foot shapes and with correction effects are shaped, and stage-by-stage correction is implemented to achieve the effect of auxiliary correction. The plastic sheet can be heated for multiple times to generate deformation according to the use requirements of the user's correction cycle, and can be heated and shaped and adjusted at different stages of rehabilitation to fit the arch shape and arch height according to the patient's foot correction state, so as to achieve the correction effect of restoring the correct biomechanical line of the foot.

Description

Technical Field

[0001] The invention relates to the technical field of materials, and in particular to a plastic insole material and application thereof. Background Art

[0002] In the modern shoemaking industry, insoles, as an important part of footwear, are not only related to wearing comfort, but also directly affect the health of the feet. With the advancement of material science, various new materials are used in the manufacture of insoles, among which ethylene-vinyl acetate copolymer (EVA for short) is highly favored due to its unique properties.

[0003] EVA is a thermoplastic elastomer made of ethylene and vinyl acetate copolymers, which has good flexibility, elasticity, chemical corrosion resistance and cushioning properties. These characteristics make EVA widely used in many fields such as insoles, sports shoes, handbags, swimming goggles, children's toys, etc. Especially in the manufacture of insoles, EVA material has become the preferred material of many shoe companies due to its advantages such as strong plasticity, easy processing and relatively low cost.

[0004] However, with the continuous improvement of material living standards, the functionality of traditional insoles is gradually unable to meet the needs. Since insoles are in a relatively humid environment for a long time, they are very easy to breed bacteria, which may cause foot odor at the mildest and bacterial infection at the worst, posing a potential threat to human health. Therefore, insole materials need to have good antibacterial properties. Although EVA has good comprehensive properties, its antibacterial properties are poor and do not meet the requirements of the modern footwear industry for insole materials. In addition, the wear resistance of EVA is also relatively general, and it is easily damaged during long-term friction, so its service life is short, so there are still deficiencies in actual use.

[0005] Based on this, the present invention provides an insole material, which is endowed with good wear resistance and antibacterial properties by adjusting the formula of the EVA insole material, so that it can meet the use requirements of the modern footwear industry. Summary of the invention

[0006] In order to solve the problems mentioned in the background technology, the purpose of the present invention is to provide a plastic insole material and application thereof.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A moldable shoe insole material, comprising the following raw materials by weight: 65-75 parts of ethylene-vinyl acetate copolymer, 15-25 parts of thermoplastic elastomer, 3-6.5 parts of wear-resistant filler, 2-4 parts of antibacterial modified material, 1-2 parts of volume extender, 0.5-1.5 parts of zinc oxide, 0.3-0.5 parts of initiator, 1-3 parts of foaming agent, and 0.5-1 parts of stabilizer;

[0009] The preparation method of the shoe insole material comprises the following steps:

[0010] The first step is to weigh each raw material according to the weight portion, first add ethylene-vinyl acetate copolymer, thermoplastic elastomer, and compatibilizer into an open mill, control the temperature in the open mill to be 110±5°C, and after banburying for 3-5 minutes, increase the temperature to 120±5°C, then add wear-resistant filler, antibacterial modified material, zinc oxide and stabilizer into the open mill, banbury for 3-5 minutes, then add initiator and foaming agent, banbury for 3-5 minutes, and then discharge the material to form a banburying material;

[0011] The second step is to place the mixed material in a mold for hot pressing and foaming to form a foamed material, and then through slicing and cutting processes, the insole material can be formed.

[0012] As a further embodiment of the present invention, the thermoplastic elastomer is at least one of SBS, SEBS or TPU.

[0013] As a further solution of the present invention, the preparation method of the wear-resistant filler comprises the following steps:

[0014] Step A, adding 3-isocyanate benzoyl chloride to acetone, stirring and mixing to form a uniform solution, placing in an ice bath, and then adding castor oil to the uniform solution. After the addition is complete, remove the ice bath, and add triethylamine. After the addition is complete, stir at room temperature for 2-4 hours, and discharge the material to obtain an intermediate material;

[0015] Step B, uniformly dispersing sisal fiber in toluene solvent, then adding intermediate material and catalyst to the formed dispersion, after adding, gradually raising the temperature to 70-80°C, keeping warm for 3-6 hours, then adding nano zirconium oxide to the dispersion, continuing stirring for 8-12 hours, cooling and discharging, and obtaining wear-resistant filler.

[0016] As a further embodiment of the present invention, in step A, the molar ratio of 3-isocyanate benzoyl chloride to castor oil is 2-3:1.

[0017] As a further embodiment of the present invention, in step B, the catalyst is at least one of stannous octoate, dibutyltin dilaurate or dibutyltin diacetate.

[0018] As a further solution of the present invention, in step B, the mass ratio of the sisal fiber to the nano zirconium oxide is 1:0.2-0.3.

[0019] By adopting the above technical solutions, first, by controlling the dosage ratio of 3-isocyanatobenzoyl chloride and castor oil, and using the condensation reaction between the active acyl chloride groups and active hydroxyl substituents in their respective structures, an intermediate material containing multiple isocyanate substituents in its structure is prepared. Then, under the catalytic action of a catalyst, using the intermediate material as a bridging reagent, nano-zirconia is loaded on the surface of sisal fibers to form a wear-resistant filler.

[0020] As a further aspect of the present invention, the preparation method of the antibacterial modifier is as follows:

[0021] Diatomite is dispersed in a 1,4-dioxane solvent. After forming a uniform dispersion, sinapic acid and a phase transfer catalyst are added to the dispersion. Under nitrogen protection, after stirring for 20 - 40 min, the temperature is gradually raised to 90 - 100 °C. After continuously stirring at this temperature for 6 - 9 h, heating is stopped, the temperature is lowered, and the material is discharged. The solid material is centrifuged to obtain the antibacterial modifier.

[0022] As a further aspect of the present invention, the phase transfer catalyst is trifluoromethanesulfonic acid or p-toluenesulfonic acid.

[0023] By adopting the above technical solutions, the surface of diatomite contains hydroxyl groups, which can, under the action of a phase transfer catalyst, condense with the active carboxyl substituents in the structure of sinapic acid, thereby modifying sinapic acid on the surface of diatomite to obtain modified diatomite with sinapic acid immobilized thereon, that is, the antibacterial modifier.

[0024] As a further aspect of the present invention, the compatibilizer is maleic anhydride grafted polyethylene or maleic anhydride grafted polypropylene; the initiator is benzoyl peroxide or diisopropylbenzene peroxide; the foaming agent is AC foaming agent; the stabilizer is zinc stearate or calcium stearate.

[0025] An application of a shapeable shoe insole material, applying the shoe insole material to insole manufacturing.

[0026] The beneficial effects of the present invention:

[0027] (1) In the present invention, by loading nano-zirconia on the surface of sisal fibers, since the bridging agent between them is castor oil with a lubricating effect, the nano-zirconia can slightly slip on the surface of sisal fibers, generating a "ball bearing" effect, thereby effectively improving the wear resistance of the insole material.

[0028] (2) The present invention can firstly improve the compatibility between diatomite and EVA matrix by immobilizing sinapinic acid on the surface of diatomite, using sinapinic acid as a "transition" structure, so that diatomite can exist in the material in the form of physical crosslinking points, effectively exert its own enhancement advantages, and improve the mechanical properties of the insole material. In addition, diatomite itself has a large number of pore structures, which can improve the air permeability of the insole material, reduce humidity, and improve comfort. In addition, sinapinic acid cannot volatilize or migrate after being immobilized on the surface of diatomite, which can ensure the long-term antibacterial performance of the insole material. Moreover, sinapinic acid, as a biomass antibacterial agent, can avoid irritation.

[0029] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0031] Figure 1 This is a scanning electron microscope image of sisal fiber and wear-resistant filler;

[0032] Figure 2 This is a schematic diagram of the application of the insole. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Preparation Example 1

[0035] Preparation of wear-resistant fillers:

[0036] Step A, adding 0.3 g of 3-isocyanate benzoyl chloride to acetone, stirring and mixing to form a uniform solution, placing in an ice bath, and then adding 0.6 g of castor oil to the uniform solution. After the addition is complete, remove the ice bath, and add 0.2 g of triethylamine. After the addition is complete, stir at room temperature for 3 hours, discharge, and obtain an intermediate material;

[0037] Step B, 1.5g of sisal fiber is evenly dispersed in toluene solvent, and then 1.8g of intermediate material and 0.1g of dibutyltin dilaurate are added to the formed dispersion. After the addition, the temperature is gradually increased to 75°C, and after keeping warm for 4 hours, 0.4g of nano zirconium oxide is added to the dispersion, and stirring is continued for 9 hours. The material is cooled and discharged to obtain a wear-resistant filler.

[0038] The surface morphology of sisal fiber and wear-resistant filler was observed by FEI QUENTA FEG 250 field emission scanning electron microscope. Figure 1 As shown, (A) is sisal fiber and (B) is wear-resistant filler. It can be seen from observation that the surface of sisal fiber is smooth without special morphology, while the surface of wear-resistant filler obviously contains a large amount of granular material. It can be reasonably inferred that the granular material is nano-zirconium oxide.

[0039] Preparation Example 2

[0040] Preparation of antibacterial modified materials:

[0041] Disperse 3 g of diatomaceous earth in 1,4-dioxane solvent to form a uniform dispersion, then add 10 g of sinapinic acid and 0.1 g of p-toluenesulfonic acid to the dispersion, introduce nitrogen protection, stir for 30 minutes, gradually increase the temperature to 100°C, stir continuously for 8 hours at this temperature, stop heating, cool and discharge, centrifuge the solid material to obtain the antibacterial modified material.

[0042] The soap back titration method was used to test the ester content of the antibacterial modified material. 0.2 g of the antibacterial modified material was used as the test sample. The test results showed that the ester content was 0.624 mmol / g, which was due to the esterification condensation between the hydroxyl groups on the surface of diatomaceous earth and the active carboxyl groups in the structure of mustard acid. Example 1

[0043] A moldable shoe insole material, comprising the following raw materials by weight: 65 parts of ethylene-vinyl acetate copolymer, 15 parts of SBS, 3 parts of wear-resistant filler, 2 parts of antibacterial modified material, 1 part of maleic anhydride grafted polyethylene, 0.5 parts of zinc oxide, 0.3 parts of benzoyl peroxide, 1 part of AC foaming agent, and 0.5 parts of zinc stearate;

[0044] The preparation method of the shoe insole material comprises the following steps:

[0045] The first step is to weigh each raw material according to the weight portion, first add ethylene-vinyl acetate copolymer, SBS, maleic anhydride grafted polyethylene into an open mill, control the temperature in the open mill to be 110°C, and after banburying for 5 minutes, increase the temperature to 120°C, then add wear-resistant filler, antibacterial modified material, zinc oxide and zinc stearate into the open mill, banbury after 5 minutes, then add benzoyl peroxide and AC foaming agent, banbury after 5 minutes, discharge the material to form a banburying material;

[0046] The second step is to place the mixed material in a mold for hot pressing and foaming to form a foamed material, and then through slicing and cutting processes, the insole material can be formed.

[0047] The preparation method of the wear-resistant filler is shown in Preparation Example 1; the preparation method of the antibacterial modified material is shown in Preparation Example 2; the same applies to the following. Example 2

[0048] A moldable shoe insole material, comprising the following raw materials by weight: 60 parts of ethylene-vinyl acetate copolymer, 20 parts of SBS, 5 parts of wear-resistant filler, 3.5 parts of antibacterial modified material, 1.5 parts of maleic anhydride grafted polyethylene, 1 part of zinc oxide, 0.4 parts of benzoyl peroxide, 2 parts of AC foaming agent, and 0.6 parts of zinc stearate;

[0049] The preparation method of the shoe insole material comprises the following steps:

[0050] The first step is to weigh each raw material according to the weight portion, first add ethylene-vinyl acetate copolymer, SBS, maleic anhydride grafted polyethylene into an open mill, control the temperature in the open mill to be 110°C, and after banburying for 5 minutes, increase the temperature to 120°C, then add wear-resistant filler, antibacterial modified material, zinc oxide and zinc stearate into the open mill, banbury after 5 minutes, then add benzoyl peroxide and AC foaming agent, banbury after 5 minutes, discharge the material to form a banburying material;

[0051] The second step is to place the mixed material in a mold for hot pressing and foaming to form a foamed material, and then through slicing and cutting processes, the insole material can be formed. Example 3

[0052] A moldable shoe insole material, comprising the following raw materials by weight: 75 parts of ethylene-vinyl acetate copolymer, 25 parts of SEBS, 6.5 parts of wear-resistant filler, 4 parts of antibacterial modified material, 2 parts of maleic anhydride grafted polyethylene, 1.5 parts of zinc oxide, 0.5 parts of benzoyl peroxide, 3 parts of AC foaming agent, and 1 part of calcium stearate;

[0053] The preparation method of the shoe insole material comprises the following steps:

[0054] The first step is to weigh each raw material according to the weight portion, first add ethylene-vinyl acetate copolymer, SEBS, and maleic anhydride grafted polyethylene into an open mill, control the temperature in the open mill to be 110°C, and after banburying for 5 minutes, increase the temperature to 120°C, then add wear-resistant filler, antibacterial modified material, zinc oxide and calcium stearate into the open mill, banbury after 3 minutes, then add benzoyl peroxide and AC foaming agent, banbury after 5 minutes, discharge the material to form a banburying material;

[0055] The second step is to place the mixed material in a mold for hot pressing and foaming to form a foamed material, and then through slicing and cutting processes, the insole material can be formed.

[0056] Comparative Example 1

[0057] A moldable shoe insole material, comprising the following raw materials by weight: 60 parts of ethylene-vinyl acetate copolymer, 20 parts of SBS, 3.5 parts of antibacterial modified material, 1.5 parts of maleic anhydride grafted polyethylene, 1 part of zinc oxide, 0.4 parts of benzoyl peroxide, 2 parts of AC foaming agent, and 0.6 parts of zinc stearate;

[0058] The preparation method of the shoe insole material comprises the following steps:

[0059] The first step is to weigh each raw material according to the weight portion, first add ethylene-vinyl acetate copolymer, SBS, maleic anhydride grafted polyethylene into an open mill, control the temperature in the open mill to be 110°C, and after banburying for 5 minutes, increase the temperature to 120°C, then add the antibacterial modified material, zinc oxide and zinc stearate into the open mill, banbury after 5 minutes, then add benzoyl peroxide and AC foaming agent, banbury after 5 minutes, discharge the material to form a banburying material;

[0060] The second step is to place the mixed material in a mold for hot pressing and foaming to form a foamed material, and then through slicing and cutting processes, the insole material can be formed.

[0061] Comparative Example 2

[0062] A moldable shoe insole material, comprising the following raw materials by weight: 60 parts of ethylene-vinyl acetate copolymer, 20 parts of SBS, 5 parts of wear-resistant filler, 3.5 parts of erucic acid, 1.5 parts of maleic anhydride grafted polyethylene, 1 part of zinc oxide, 0.4 parts of benzoyl peroxide, 2 parts of AC foaming agent, and 0.6 parts of zinc stearate;

[0063] The preparation method of the shoe insole material comprises the following steps:

[0064] The first step is to weigh each raw material according to the weight portion, first add ethylene-vinyl acetate copolymer, SBS, maleic anhydride grafted polyethylene into an open mill, control the temperature in the open mill to be 110°C, and after banburying for 5 minutes, increase the temperature to 120°C, then add wear-resistant filler, sinapinic acid, zinc oxide and zinc stearate into the open mill, banburying for 5 minutes, then add benzoyl peroxide and AC foaming agent, banburying for 5 minutes, and then discharge the material to form a banburying material;

[0065] The second step is to place the mixed material in a mold for hot pressing and foaming to form a foamed material, and then through slicing and cutting processes, the insole material can be formed.

[0066] Comparative Example 3

[0067] A moldable shoe insole material, comprising the following raw materials by weight: 60 parts of ethylene-vinyl acetate copolymer, 20 parts of SBS, 5 parts of wear-resistant filler, 3.5 parts of diatomaceous earth, 1.5 parts of maleic anhydride grafted polyethylene, 1 part of zinc oxide, 0.4 parts of benzoyl peroxide, 2 parts of AC foaming agent, and 0.6 parts of zinc stearate;

[0068] The preparation method of the shoe insole material comprises the following steps:

[0069] The first step is to weigh each raw material according to the weight portion, first add ethylene-vinyl acetate copolymer, SBS, maleic anhydride grafted polyethylene into an open mill, control the temperature in the open mill to be 110°C, and after banburying for 5 minutes, increase the temperature to 120°C, then add wear-resistant filler, diatomaceous earth, zinc oxide and zinc stearate into the open mill, banburying for 5 minutes, then add benzoyl peroxide and AC foaming agent, banburying for 5 minutes, and then discharge the material to form a banburying material;

[0070] The second step is to place the mixed material in a mold for hot pressing and foaming to form a foamed material, and then through slicing and cutting processes, the insole material can be formed.

[0071] Test Case

[0072] Various performance tests were performed on the insole materials in Examples 1 to 3 and Comparative Examples 1 to 3, and the results are recorded in Table 1:

[0073] Table 1 - Test results

[0074]

[0075] Note: The antibacterial rate test refers to the standard GB / T 20944.3-2008, the test bacteria is Escherichia coli, and the test time is after the material is made into the corresponding test sample and placed at room temperature for 2 months;

[0076] The test method of the rebound rate is as follows: the material is made into a test sample with a specification of 100mm×100mm×10mm, and then compacted with a 20kg iron block. After 30 minutes, the iron block is removed, and the height of the sample is measured after standing for 1 minute, recorded as X. The result is calculated using the formula [(10-X) / 10]×100% and recorded as the rebound rate.

[0077] Absolute wear test reference standard GB / T 9867-2008;

[0078] From the analysis and test results, it can be seen that the insole material prepared by adding wear-resistant fillers and antibacterial modified materials as additives has significantly better antibacterial properties, mechanical properties and wear resistance. After removing the wear-resistant filler, it can be clearly observed that the wear resistance of the material has decreased significantly. After the antibacterial modified material was replaced with a small molecule antibacterial agent, mustard acid, due to volatilization and migration, the antibacterial effect declined significantly after being placed at room temperature for 2 months. After the antibacterial modified material was replaced with diatomaceous earth, the antibacterial effect of mustard acid was lost, resulting in significantly poor antibacterial performance of the material, and there were compatibility issues between diatomaceous earth and the EVA matrix, and the improvement of the mechanical properties of the material was also relatively limited.

[0079] In the process of applying a moldable insole material, the moldable sheet can be shaped according to the foot shape of each person, can meet the needs of different arch heights, and shape insoles that are suitable for the foot shape and have corrective effects according to the actual conditions of users in different orthopedic stages, implement stage-by-stage correction, and achieve the role of auxiliary correction. The moldable sheet can be heated multiple times to produce deformation according to the user's correction cycle usage needs, fit the arch shape and arch height, and can be heated and shaped and adjusted at different stages of rehabilitation according to the patient's foot correction status, so as to achieve the correction effect of restoring the correct biomechanical line of the foot.

[0080] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A moldable shoe insole material, characterized in that: The following raw materials are included in parts by weight: 65-75 parts of ethylene-vinyl acetate copolymer, 15-25 parts of thermoplastic elastomer, 3-6.5 parts of wear-resistant filler, 2-4 parts of antibacterial modified material, 1-2 parts of compatibilizer, 0.5-1.5 parts of zinc oxide, 0.3-0.5 parts of initiator, 1-3 parts of foaming agent, and 0.5-1 parts of stabilizer; The preparation method of the shoe insole material comprises the following steps: The first step is to weigh each raw material according to the weight portion, first add ethylene-vinyl acetate copolymer, thermoplastic elastomer, and compatibilizer into an open mill, control the temperature in the open mill to be 110±5°C, and after banburying for 3-5 minutes, increase the temperature to 120±5°C, then add wear-resistant filler, antibacterial modified material, zinc oxide and stabilizer into the open mill, banbury for 3-5 minutes, then add initiator and foaming agent, banbury for 3-5 minutes, and then discharge the material to form a banburying material; The second step is to place the mixed material in a mold for hot pressing and foaming to form a foamed material, and then to form a shoe insole material through a slicing and cutting process; The preparation method of the antibacterial modified material is as follows: Disperse diatomaceous earth in 1,4-dioxane solvent to form a uniform dispersion, add sinapinic acid and a phase transfer catalyst to the dispersion, introduce nitrogen protection, stir for 20-40 minutes, gradually increase the temperature to 90-100°C, stir continuously for 6-9 hours under this temperature condition, stop heating, cool and discharge, centrifuge the solid material to obtain the antibacterial modified material.

2. The moldable insole material according to claim 1, characterized in that: The thermoplastic elastomer is at least one of SBS, SEBS or TPU.

3. The moldable insole material according to claim 1, characterized in that: The preparation method of the wear-resistant filler comprises the following steps: Step A, adding 3-isocyanate benzoyl chloride to acetone, stirring and mixing to form a uniform solution, placing in an ice bath, and then adding castor oil to the uniform solution. After the addition is complete, remove the ice bath, and add triethylamine. After the addition is complete, stir at room temperature for 2-4 hours, and discharge the material to obtain an intermediate material; Step B, uniformly dispersing sisal fiber in toluene solvent, then adding intermediate material and catalyst to the formed dispersion, after adding, gradually raising the temperature to 70-80°C, keeping warm for 3-6 hours, then adding nano zirconium oxide to the dispersion, continuing stirring for 8-12 hours, cooling and discharging, and obtaining wear-resistant filler.

4. The moldable insole material according to claim 3, characterized in that: In step A, the molar ratio of 3-isocyanate benzoyl chloride to castor oil is 2-3:

1.

5. The moldable insole material according to claim 3, characterized in that: In step B, the catalyst is at least one of stannous octoate, dibutyltin dilaurate or dibutyltin diacetate.

6. The moldable insole material according to claim 3, characterized in that: In step B, the mass ratio of the sisal fiber to the nano zirconium oxide is 1:0.2-0.

3.

7. The moldable insole material according to claim 1, characterized in that: The phase transfer catalyst is trifluoromethanesulfonic acid or p-toluenesulfonic acid.

8. The moldable insole material according to claim 1, characterized in that: The compatibilizer is maleic anhydride grafted polyethylene or maleic anhydride grafted polypropylene; the initiator is benzoyl peroxide or dicumyl peroxide; the foaming agent is AC foaming agent; and the stabilizer is zinc stearate or calcium stearate.

9. The use of a moldable shoe insole material according to claim 1, characterized in that: The insole sheet material is applied to the manufacture of insoles.

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