Method of manufacturing shoe sole material and shoes products made by the same

• US 4,418,483 A
• Filed: 03/31/1981
• Issued: 12/06/1983
• Est. Priority Date: 03/31/1981
• Status: Expired due to Fees

• Current Assignee: Rinzai Company Limited
• Original Assignee: Rinzai Company Limited
• Inventors: Fujita, Minoru, Nishida, Shigeo
• Primary Examiner(s): Anderson, Philip E.
• Application Number:
  US06/249,451
• Time in Patent Office: 980 Days
• Field of Search: 264/45.5, 264/54, 264/45.1, 264/46.6, 264/257, 264/236, 264/241, 264/DIG. 18, 36/28, 36/25 R, 36/30 R, 36/32 R
• US Class Current: 36/28
• CPC Class Codes: A43B 13/12 Soles with several layers of different materials
• CPC Class Codes: A43B 13/187 Resiliency achieved by the features of the material, e.g. foam, non liquid materials
• CPC Class Codes: B29C 43/021 characterised by the shape of the surface
• CPC Class Codes: B29C 44/10 Applying counter-pressure during expanding
• CPC Class Codes: B29D 35/142 Soles
• CPC Class Codes: B29D 35/148 Moulds or apparatus therefor
• CPC Class Codes: B29K 2105/04 cellular or porous
• CPC Class Codes: B29K 2105/253 Preform
• CPC Class Codes: B29L 2031/504 Soles
• CPC Class Codes: B32B 2437/02 Gloves, shoes
• CPC Class Codes: B32B 25/08 of synthetic resin
• CPC Class Codes: C08J 9/00 Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof mechanical aspects of shaping of plastics or substances in a plastic state for the production of porous or cellular articles B29C
• CPC Class Codes: C08J 9/10 developing nitrogen , the blowing agent being a compound containing a nitrogen-to-nitrogen bond
• CPC Class Codes: Y10S 264/18 Cross-linking a thermoplastic linear foam during molding
• CPC Class Codes: Y10T 428/249976 Voids specified as closed
• CPC Class Codes: Y10T 428/249981 Plural void-containing components

Abstract

A method of manufacturing shoe sole material which is lightweight in addition to having such properties as the conventional rubber sole materials have like wear resistance and elasticity etc., in a simple manner by forming the outsole and midsole layers into one piece by fusion using a mold. The mold comprises mold pieces having on their surface optional pattern and protruding stripes of the same or different pattern carved at equal intervals, and permits a streamline-shaped heel-up on the rear end of the portions which are to become heels, at the same time as forming the midsole and outsole layers into one piece by fusion.

Claims

1. A method of manufacturing shoe sole material, which comprises:

superposing a first sheet for a midsole layer on a second sheet for an outsole layer in a mold having a pattern formed on at least the mold surface in contact with said second sheet, said first sheet comprising a synthetic resin, a crosslinking agent and a foaming agent, said second sheet comprising a synthetic resin, a crosslinking agent and a foaming agent, said first and second sheets having different foamability ratios and being capable of being fused together under heat; and

hot-pressing said superposed first and second sheets in said mold to foam at least said first sheet and form crosslinkages in and between said first and second sheets to fuse said first and second sheets together.

2. A method according to claim 1, wherein said mold has patterns formed on the mold surfaces in contact with both said first and second sheets.

3. A method according to claim 1, wherein said first sheet is composed mainly of 1,2-polybutadiene, an ethylene-vinyl acetate copolymer or a synthetic rubber, and has a foaming ratio from 1.5 to 15 and a hardness from 30 to 80 when formed into said midsole layer.

4. A method according to claim 1, wherein said midsole layer comprises two or more layers having different foaming ratios or different hardnesses.

5. A method according to claim 1, wherein said second sheet is composed mainly of 1,2-polybutadiene, an ethylene-vinyl acetate copolymer or a synthetic rubber, and has a hardness from 45 to 98 when formed into said outsole layer.

6. A shoe product containing the shoe sole material manufactured according to the method of claim 1.

7. A method of manufacturing shoe sole material, which comprises:

superposing a first sheet for a midsole layer on a second sheet for an outsole layer in a mold having a pattern formed on at least the mold surface in contact with said second sheet, at least said mold surface in contact with said second sheet further having protruding stripes at equal intervals on said mold surface, said first sheet comprising a synthetic resin, a crosslinking agent and a foaming agent, said second sheet comprising a synthetic resin, a crosslinking agent and a foaming agent, said first and second sheets having different foamability ratios and being capable of being fused together under heat; and

hot-pressing said superposed first and second sheets in said mold to foam at least said first sheet and form crosslinkages in and between said first and second sheets to fuse said first and second sheets together, and to form a streamline-shaped heel-up on the portion of said shoe sole material which is to become the heel of the shoe.

8. A method according to claim 7, wherein said mold has patterns and protruding stripes formed on the mold surfaces in contact with both said first and second sheets.

9. A method according to claim 7, wherein said protruding stripes are formed in parallel at certain intervals.

10. A method according to claim 7, wherein said first sheet is composed mainly of 1,2-polybutadiene, an ethylene-vinyl acetate copolymer or a synthetic rubber, and has a foaming ratio from 1.5 to 15 and a hardness from 30 to 80 when formed into said midsole layer.

11. A method according to claim 7, wherein said midsole layer comprises two or more layers having different foaming ratios or different hardnesses.

12. A method according to claim 7, wherein said second sheet is composed mainly of 1,2-polybutadiene, an ethylene-vinyl acetate copolymer or a synthetic rubber, and has a hardness from 45 to 98 when formed into said outsole layer.

13. A shoe product containing the shoe sole material manufactured according to the method of claim 7.