Biodegradable hook-type molded surface fastener with outstanding moldability

Patent metadata

Field	Value
Publication number	US-11980259-B2
Application number	US-202017441327-A
Country	US
Kind code	B2
Filing date	Mar 26, 2020
Priority date	Mar 28, 2019
Publication date	May 14, 2024
Grant date	May 14, 2024

Abstract

A molded hook surface fastener having a base plate and hook engaging elements projecting from a surface of the base plate, both the base plate and the hook engaging elements being formed of a resin mixture containing polybutylene succinate (A), a modified starch having an amylose content of 45% by weight or more (B), and polyvinyl alcohol (C). The resin mixture is further characterized by having both a continuous phase and a dispersed phase, with the polybutylene succinate (A) present in the continuous phase, and the modified starch (B) and polyvinyl alcohol (C) present in the dispersed phase.

First claim

The invention claimed is:

1. A molded hook surface fastener having a base plate and hook engaging elements projecting from a surface of the base plate,
wherein both the base plate and the hook engaging elements comprise a resin mixture comprising polybutylene succinate, a modified starch having an amylose content of 45% by weight or more (B), and polyvinyl alcohol (C);
and wherein
the hook engaging elements each taper from the surface of the base plate toward a distal end portion thereof and bend from a middle portion thereof such that the distal end portion of the hook engaging elements face a direction approaching the surface of the base plate, and
the resin mixture further comprises a continuous phase and a dispersed phase, said polybutylene succinate (A) being present in the continuous phase, and said modified starch having an amylose content of 45% by weight or more (B) and said polyvinyl alcohol (C) being present in the dispersed phase.

2. The molded hook surface fastener according to claim 1 , wherein a ratio of the polyvinyl alcohol (C) to a total weight of the starch (B) and the polyvinyl alcohol (C) in the resin mixture is 2 to 75% by weight.

3. The molded hook surface fastener according to claim 1 , wherein a ratio of the polybutylene succinate (A) to a total weight of the polybutylene succinate (A), the starch (B), and the polyvinyl alcohol (C) in the resin mixture is 45 to 90% by weight.

4. The molded hook surface fastener according to claim 1 , wherein the modified starch is etherified starch comprising a hydroxyalkyl group.

5. The molded hook surface fastener according to claim 1 , wherein the dispersed phase further comprises clay.

6. The molded hook surface fastener according claim 1 , wherein the dispersed phase further comprises water in an amount of 3 to 30% by weight based on the starch (B).

7. The molded hook surface fastener according to claim 1 , wherein the dispersed phase further comprises a saturated fatty acid or a metal salt thereof.

8. A method for producing a molded hook surface fastener, the method comprising:
covering a surface of a metal roll that has on its surface plural cavities with a molten resin mixture in a sheet form while pressing the molten resin mixture into the plural cavities, wherein each of the plural cavities has a shape corresponding to a hook engaging element;
solidifying the resin mixture in the plural cavities; and
peeling the sheet of the resin mixture from the surface of the metal roll while pulling the solidified resin mixture out of the plural cavities;
wherein:
the plural cavities taper from the surface of the metal roll to a distal end portion of the plural cavities and bend from a middle portion thereof along a circumferential direction of the metal roll, and the distal end portion of the plural cavities faces a direction approaching the surface of the metal roll;
on the surface of the metal roll, the plurality of cavities are arranged in a row in the circumferential direction of the metal roll, and a plurality of such rows are present in the width direction of the metal roll, wherein one row or a plurality of rows of cavities that extend in the circumferential direction and another different row or plurality of rows of cavities that bend in a direction opposite to a bending direction of the above cavities and extend in the circumferential direction are alternately arranged; and
the resin mixture comprises a continuous phase and a dispersed phase, polybutylene succinate (A) is present in the continuous phase, and modified starch having an amylose content of 45% by weight or more (B) and polyvinyl alcohol (C) are present in the dispersed phase.

9. The molded hook surface fastener according to claim 1 , wherein said modified starch having an amylose content of 45% by weight or more (B) is the only starch present in said resin mixture.

10. The molded hook surface fastener according to claim 1 , wherein:
a ratio of the polybutylene succinate (A) to a total weight of the polybutylene succinate (A), the starch (B), and the polyvinyl alcohol (C) in the resin mixture is 55 to 85% by weight;
a ratio of the polyvinyl alcohol (C) to a total weight of the starch (B) and the polyvinyl alcohol (C) in the resin mixture is 5 to 70% by weight;
the modified starch (B) has an amylose content of 55% by weight or more; and the
polyvinyl alcohol (C) has a saponification degree of 85 to 99.8% by ol.

11. The molded hook surface fastener according to claim 10 , wherein said modified starch (B) is the only starch present in said resin mixture.

Assignees

• Kuraray Fastening Co Ltd
• Kuraray Co

Inventors

• Koga Nobuhiro
• Ono Satoru
• Ide Junya
• Fujisawa Yoshikatsu

Classifications

• A44B18/0049 Primary

  obtained by moulding processes (compression moulding or articles of indefinite length characterised by the shape of the surface B29C43/222; screen moulding B29C67/08) · CPC title

• B29C41/26

  by depositing flowable material on a rotating drum · CPC title

• C08L67/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title

• B29K2029/04

  PVOH, i.e. polyvinyl alcohol (B29K2031/04 takes precedence) · CPC title

• B29K2995/006

  Bio-degradable, e.g. bioabsorbable, bioresorbable or bioerodible · CPC title