KR20030033806A - Manufacturing method of outsole or midsole for sports shoes - Google Patents

Abstract

PURPOSE: Provided is a production process of outsole or midsole of shoes which passes through two continuous molding processes to produce a product so that it increases adhesion power with improving the quality of the product. CONSTITUTION: The production process of the outsole or the midsole of the shoes comprises the steps of: (i) producing a first preform smaller than the size of the final product by a first injection molding or compression molding; and (ii) projecting the preform into a press with heating to cross-link and foam the preform within the press to complete appearance of the outsole or the midsole of the shoes.

Description

Manufacturing method of outsole and midsole for shoes {Manufacturing method of outsole or midsole for sports shoes}

The present invention relates to a method for manufacturing a shoe outsole and midsole, and more particularly, after preparing a primary preform smaller than the desired window size by injection molding or compression molding the foam mixture, the preform required size After injection into the mold of secondary compression molding, the cross-linking and foaming are progressed once again, and the appearance of the window is completed by cooling molding, so there is little loss of raw materials, excellent adhesive properties, and there is no big variation in physical properties according to the part of the window. The present invention relates to a method for manufacturing shoe outsoles and midsoles, which makes it possible and has excellent matt properties.

In the case of the shoe industry, it was evaluated as a labor-intensive industry, and Korea also led the domestic export industry as the world's leading shoe production base with low wages and excellent labor. However, as the price competitiveness decreases due to the increase in labor wages, the perception of a labor-intensive and low-value-added industry spreads, and as the will for development of shoes weakens, it is gradually losing its competitiveness. In this reality, the application of existing manufacturing methods for midsoles and outsoles for shoes incurs a large amount of raw material loss, weakening price competitiveness, and reversing the era in terms of environmental friendliness, which is currently being emphasized throughout society. It is true.

Therefore, in order for the domestic shoe industry to serve as a shoe production base, and to maintain the price competitiveness of shoe products in the current high wage system, the development of technology focusing on the parts for shoes, which have a technological edge, along with productivity improvement and shortening of processes, etc. It would be desirable to maintain a production system of technological advantage. As one method for this purpose, it was intended to secure the competitiveness of the improved foam molding method for shoes. In the case of the existing thermal re-molding method, after the first preform was manufactured, it was made into a rough window shape through cutting and grinding, and then, it was put into a mold and subjected to secondary compression molding to manufacture a shoe midsole or outsole [Phylon method]. When using this method, it is necessary to go through the cutting and grinding process, which leads to complicated work process and loss of a large amount of raw materials, and manufactures the window through compression molding. There is a problem that appears very different. In order to solve this problem, a new thermal re-forming method was developed. Unlike the existing thermal re-forming method, the first preform is directly manufactured in the form of a window, and it is directly processed through the second compression molding without the process of cutting and grinding. Outsoles were prepared [CMP method]. The new thermal re-forming method is very efficient in terms of loss of raw materials and work process improvement, which is a problem in the existing thermal re-forming method, but there are still problems that the physical properties of parts of the window appear differently according to the compression process. In addition, since the first preform is used as it is and the second compression molding, the thickness of the skin layer is increased in the case of the midsole and the outsole manufactured as described above. It becomes difficult to upscale. The injection molding method was introduced to solve the problems in the thermal re-molding method, but in the case of the injection molding, the flowability of the kneaded material becomes a big problem, causing a limitation of the range of use of the polymer and the additive used [Injection method].

Therefore, the inventors of the present invention desired the size of the window desired by injection molding or compression molding the kneaded material for foam in order to improve the loss of raw materials and work process, and to improve the product quality and high functionality in terms of environmental friendliness and price competitiveness. After preparing a smaller primary preform, the present invention is prepared by injecting the preform into a mold of a required size, and further performing crosslinking and foaming by secondary compression molding and manufacturing a shoe outsole or midsole by cooling molding. Completed.

Accordingly, an object of the present invention is to provide a shoe outsole or midsole manufacturing method capable of improving the quality and high functionality of the product as well as the loss of raw materials and the improvement of the work process.

The present invention is to prepare the primary preform by injection molding or compression molding the foam mixture, and then put the preform into the mold to proceed crosslinking and foaming again to the secondary compression molding and to complete the appearance of the window by cooling molding. It is characterized by the manufacturing method of the outsole or midsole.

The present invention will be described in detail as follows.

In the present invention, first, a kneaded product is prepared using EVA (Ethylene Vinyl Acetate) or an ethylene-alpha-olefin copolymer which is used as a general foam material to prepare a kneaded product for foam. In this case, a crosslinking agent and a foaming agent should be used. In the case of the crosslinking agent, the peroxide-based compound, preferably 1-minute half-life temperature of 130 to 200 ° C., is selected from t-butylperoxyisopropyl carbonate and t-butylperoxylaurate. , Benzoyl peroxide, t-butyl peroxy acetate, t-butyl peroxy benzoate, di-t-butyl diperoxy phthalate, t-butyl peroxy maleic acid, cyclohexanone peroxide, t-butyl cumyl peroxide, t- Butylhydroperoxide, 1,1-bis (t-butylperoxy) -3,3,5-srimethylcyclohexane, t-butylperoxybenzoate, dicumylperoxide, 2,2-bis (t- Butylperoxy) butane, 1,1-di (t-butylperoxy) cyclohexane, methylethylketone peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5 -Dimethyl-2,5- (t-butylperoxy) hexyn-3, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylper Oxy) hexin-3, 2,5-dimethyl-2,5-di (ben) Ylperoxy) hexane-3, di-t-butylperoxide, di-t-butylperoxide, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,2'-bis (butyl 0.3-1.5 weight part of peroxyisopropyl) benzene etc. are used with respect to 100 weight part of base materials. In this case, when the amount of the crosslinking agent is less than 0.3 parts by weight, the appearance of the foam may be unstable or the mechanical properties may be deteriorated due to incomplete crosslinking. When the amount of the crosslinking agent is used, the foam may be torn due to the overcrossing phenomenon of the foam.

In addition, in order to increase the crosslinking efficiency of the crosslinking agent, a crosslinking aid may also be used. Sulfur, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane trimethacrylate, diethylene glycol diacrylate, and diethylene glycol dimetha 0.1 to 2.0 parts by weight of acrylate, butylene glycol acrylate, butylene glycol dimethacrylate, metal acrylate, metal methacrylate, 1,2-polybutadiene and the like are used based on 100 parts by weight of the substrate.

Examples of the blowing agent include azo compounds such as azodicarbonamide (ADCA), azobisisobutyronitrile and diazoaminoazobenzene having a decomposition temperature of 130 to 200 ° C, and N, N'-dinitrosopentamethylenetetraamine (DPT Nitroso-based compounds such as), sulfonylhydrazide-based compounds such as p-toluenesulfonylhydrazide (TSH), p, p'oxybis (benzenesulfonylhydrazide) (OBSH), and benzenesulfonylhydrazide, p 1-7 weight part of toluene sulfonyl semicarbazide (TSS) etc. are used individually or in combination and 100 weight part of base materials are used. At this time, if less than 1 part by weight, the specific gravity of the foam is high, there is a problem in terms of weight reduction, and when it is used over 7 parts by weight of the foam uniformity due to the drop in physical properties due to low specific gravity of the foam and sudden expansion beyond the limit of high temperature viscoelasticity of the resin There is a problem that the foam of the foam can not be obtained.

The window for the foam is manufactured by using a kneaded material which can exhibit various physical properties and expansion ratios thus prepared. First, injection molding or compression molding is used to manufacture the window of the primary preform, and the size of the primary preform is designed to occupy about 30 to 80% of the mold used for the secondary compression molding. Therefore, the size of the primary preform must be changed according to the size of the mold used in the secondary press, which is determined by adjusting the foaming quantity or adjusting the size of the mold used for manufacturing the primary preform. The conditions for the preparation of the primary preform are compression molding for about 3 to 4 minutes under conditions of 130 to 190 ° C, preferably 170 ° C and 120 to 170 kg / cm ² , preferably 150 kg / cm ² for compression molding. In the case of injection molding, a primary preform in which crosslinking and foaming are advanced is formed by molding at 130 to 190 ° C, preferably at 170 ° C for 3 to 4 minutes. The primary preform thus prepared is put into a mold of the required size and the secondary compression molding is carried out at 150 to 180 ° C, preferably at 170 ° C and 120 to 170 kg / cm ² , preferably at 150 kg / cm ² . It is carried out for about 8 to 10 minutes under the conditions, and is heated in the mold to expand by crosslinking and foaming again, and cooled in the mold as it is to form the window. In the case of the midsole or outsole manufactured in this way, raw material loss can be reduced and the work process can be simplified compared to the thermal re-molding method. Since the reshaping is not performed through compression, the difference in physical properties according to the part of the window is not large. The thin thickness enables the manufacture of foam having excellent adhesion and matting effect, which enables the manufacture of highly functional and high quality windows.

Hereinafter, the present invention will be described in detail based on the following examples, but the present invention is not limited thereto.

Example 1

3 parts by weight of zinc oxide and 1 part by weight of stearic acid were mixed in a kneader at 95 ° C. for about 10 minutes based on 100 parts by weight of EVA 360 alone, and then 100 parts by weight of the EVA substrate in a roll mill having a surface temperature of 85 ° C. The kneaded material was manufactured using 0.6 weight part of dicumyl peroxide as a crosslinking agent, and 3 weight part of CELLCOM-JTR of Kumyang Co., Ltd. which is an azodicarbonamide (ACDA) system as a foaming agent. The kneaded material thus prepared is put into a small window-shaped mold and compression molded at 170 ° C. and 150 kg / cm ² for 3 minutes to prepare a primary preform, and then to a mold having the same size as the required window. After the compression molding for 10 minutes at 170 ℃, 150 kg / cm ² conditions to prepare a window through the cooling molding. Thus, the second compression molding to produce a shoe midsole with a uniform overall physical properties, excellent matting effect, and excellent adhesive properties.

Example 2

3 parts by weight of zinc oxide and 1 part by weight of stearic acid were mixed in a kneader at 95 ° C. for about 10 minutes with respect to 100 parts by weight of EVA 360 alone, and then 100 parts by weight of the EVA substrate in a roll mill having a surface temperature of 85 ° C. The kneaded material was manufactured using 0.7 weight part of bis- (t-butylperoxy isopropyl) benzene as a crosslinking agent, and 3.2 weight part of CELLCOM-OHSH of Geumyang Co., Ltd. which is sulfonyl hydrazide type as a foaming agent. The kneaded product thus prepared is injection molded into a small window-shaped mold at 170 ° C. for 3 minutes to prepare a preform, and then it is put into a mold having the same size as the required window, and the temperature is 170 ° C. and 150 kg / cm ² . After compression molding for 8 minutes under the conditions, the window was manufactured by cooling. Thus, the second compression molding to produce a shoe midsole with a uniform overall physical properties, excellent matting effect and excellent adhesive properties.

Example 3

After mixing about 3 minutes by weight of zinc oxide and 1 part by weight of stearic acid with respect to 100 parts by weight of the mixture substrate of EVA 460 and the ethylene-alpha-olefin copolymer, the surface temperature was 95 Geumyang Co., Ltd. is an isodicarbonamide-based (ADCA) 0.8% by weight of a crosslinking agent and a blowing agent, based on 100 parts by weight of the substrate mixture of EVA 460 and an ethylene-alpha-olefin copolymer in a roll mill at 0 ° C. A kneaded material was prepared using 2.8 parts by weight of CELLCOM-AC3000. The kneaded product thus prepared is compression molded into a small window-shaped mold at 170 ° C. for 3 minutes to prepare a preform, and then it is put in a mold having the same size as the required window, and the temperature is 170 ° C. and 150 kg / cm ² . After compression molding for 9 minutes under the conditions, a window was manufactured by cooling. Thus, the secondary compression molding produced a shoe outsole for excellent permanent compression reduction rate, excellent matting effect, and excellent adhesive properties.

Comparative Example 1

The shoe outsole (or midsole) manufactured by the Phylon method currently commonly used was compared with the above examples.

Test Example

1. Hardness: The middle part of the foam was cut and measured in accordance with ASTM D-2240 with an Asker C type hardness tester.

2. Compression set: Compression set: The foam was made to be 10 mm thick and manufactured into a cylindrical shape having a diameter of 30 ± 0.05 mm. Place the specimen between two parallel metal plates, insert a spacer equal to 50% of the specimen thickness, compress it, heat it in an air-circulating oven maintained at 50 ± 0.1 ° C for 6 hours, and remove the specimen from the compression device. After cooling for 30 minutes at room temperature the thickness was measured. Three specimens were used in the same test, and the compression set (Cs) was calculated by the following equation (1).

t ₀ : Initial thickness of the test piece

t _f : thickness of specimen when cooled after heat treatment

t _s : thickness of spacer

3. Matte effect: The gloss of the surface of the foam was measured using a reflectometer.

4. Split tear strength: The specimen was manufactured by cutting 10 mm × 20 mm × 120 mm and cutting it to 25 mm in the longitudinal direction. The measuring speed was measured 5 times at 50 mm / min. Was taken.

division Example 1 Example 2 Example 3 Comparative Example 1 (C company) Hardness (type C) 60 62 62 63 importance 0.251 0.244 0.238 0.263 Permanent Compression Shrinkage (%) 52 45 40 62 Gloss 6.4 5.9 7.8 19.3 Rupture Tear Strength (kgf / cm) 3.0 3.1 3.2 2.2

In the case of the comparative example, the loss of raw materials, the hardness difference between parts was large, and when the EVA was not used a lot, the adhesive problem appeared and the gloss of the product appeared so that the quality of the product was impossible. On the other hand, in the case of the embodiment, the loss of the raw material is excellent, the adhesive property is excellent, the variation of the physical properties according to the part of the window is not large, enabling the quality of the product and the matte properties were excellent.

As described above, according to the present invention, a foamed kneaded product having various characteristics is manufactured into a primary preform smaller than a desired window size by injection molding or compression molding, and then the prepared preform is introduced into a mold having a required size. After heating again, cross-linking and foaming in the mold is progressed once again, and the appearance of the window is completed through the secondary molding to fix and cool. There is little loss of raw materials, excellent adhesive properties, and no significant variation in physical properties according to the part of the window. The present invention relates to a manufacturing method of a shoe outsole or midsole that enables high-quality and excellent matte properties.

Claims (5)

After preparing a primary preform smaller than the final product size by primary injection molding or compression molding of the foamed kneaded product, the secondary foam is subjected to crosslinking and foaming in the mold and to be heated by cooling the preform. Method of manufacturing a shoe outsole or midsole, characterized in that the appearance of the window through the compression molding. The azo-based compound, nitroso-based compound, sulfonylhydrazide according to claim 1, wherein the crosslinking agent is 0.3 to 1.5 parts by weight based on 100 parts by weight of the base material as a peroxide compound, and the blowing agent has a decomposition temperature of 130 to 200 ° C. A method for producing an outsole or midsole for footwear, characterized in that 1 to 7 parts by weight based on 100 parts by weight of the base compound and p-toluene sulfonyl semicarbazide (TSS). The method of claim 2, wherein the substrate is EVA (Ethylene-Vinyl Acetate) or ethylene-alpha-olefin copolymer. The method of claim 1, wherein the primary injection molding or compression molding is 130 to 190 ℃, 120 to 170 kg / cm^2,Molding under conditions of 3 to 4 minutes, the secondary compression molding is 150 to 180 ℃, 120 to 170 kg / cm², 8 Method for producing a shoe outsole or midsole, characterized in that molded for 10 minutes. The method of claim 1, wherein the size of the preform during the production of the primary preform is 30 to 80% of the mold.