US-12616279-B2 - Surface fastener

Abstract

A surface fastener includes a base portion and a plurality of engaging elements, the base portion and the engaging elements include a thermoplastic resin at least partially including a plant-derived resin, the plant-derived resin has an MFR of 5 g/10 min or more and 30 g/10 min or less, and has a flexural modulus of 800 MPa or more and 2300 MPa or less, and, in plan view of each of the engaging elements, the engaging head portion is such that at least a part of the engaging head portion has a shape protruding outward with respect to an upper end of the stem portion. Therefore, the surface fastener can include a plurality of engaging elements. In addition, compared to the related art, it is possible to reduce the use of fossil-resource-derived resin to thereby reduce the load on the environment.

Inventors

• Yoshiyuki Fukuhara
• Takuya Nozaki

Assignees

• YKK CORPORATION

Dates

Publication Date

20260505

Application Date

20211210

Claims (6)

1. 1 . A surface fastener comprising a base portion and a plurality of engaging elements that are provided on one surface of the base portion, each engaging element including a stem portion that extends upward from the base portion and an engaging head portion that is integrally formed with an upper end of the stem portion, wherein the base portion and the engaging elements include a thermoplastic resin that at least partially includes a plant-derived resin, the plant-derived resin has a melt flow rate of 5 g/10 min or more and 30 g/10 min or less, and a flexural modulus of 800 MPa or more and 2300 MPa or less, and in plan view of each of the engaging elements, the engaging head portion is such that at least a part of the engaging head portion has a shape that protrudes outward with respect to the upper end of the stem portion.
2. 2 . The surface fastener according to claim 1 , wherein each of the engaging head portions has a head-portion top end surface that faces upward, an outer peripheral side surface that inclines or curves downward from an outer peripheral edge of the head-portion top end surface, and a head-portion rear surface that is disposed between the outer peripheral side surface and the upper end of the stem portion, and a rear surface angle between a portion of the head-portion rear surface that extends from the upper end of the stem portion and an imaginary line that is extended downward from the upper end of the stem portion is less than or equal to 120 degrees.
3. 3 . The surface fastener according to claim 1 , wherein the thermoplastic resin includes plant-derived polyethylene by a proportion of 25 parts by weight to 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin.
4. 4 . The surface fastener according to claim 1 , wherein the thermoplastic resin is formed from a mixture of plant-derived polyethylene and fossil-resource-derived polypropylene, the plant-derived polyethylene is included in the thermoplastic resin by a proportion of greater than or equal to 25 parts by weight and less than 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin, and the fossil-resource-derived polypropylene has a melt flow rate of 5 g/10 min or more and 60 g/10 min or less, and a flexural modulus of 600 MPa or more and 2300 MPa or less.
5. 5 . The surface fastener according to claim 1 , wherein each of the engaging elements is provided with at least one very small pawl portion that protrudes from an outer peripheral edge portion of the engaging head portion.
6. 6 . The surface fastener according to claim 5 , wherein the at least one very small pawl portion extends downward toward the base portion from the outer peripheral edge portion of the engaging head portion corresponding thereto.

Description

TECHNICAL FIELD The present invention relates to a surface fastener and a method of manufacturing a surface fastener. BACKGROUND ART Surface fasteners are currently widely used in various products, and are also frequently used in, for example, disposable diapers, diaper covers for infants, supporters that protect hand and foot joints or the like, waist corsets (belts for lower back pain), and products that are attachable to and detachable from the body, such as gloves. In addition, surface fasteners of the related art are generally made of fossil-resource-derived synthetic resins. In recent years, interest in various problems, such as environmental problems, is increasing, and measures are being taken to achieve sustainable development goals. As one measure, with regard to the use of fossil-resource-derived resins, problems are being pointed out, such as the generation of greenhouse gases, environmental pollution caused by disposed waste, and the dangers of depletion of fossil resources. Therefore, instead of fossil-resource-derived resins, the use of plant-derived resins (may also be called “biomass-derived resins”) whose raw material is a renewable biological resource or the use of biodegradable resins is being considered. The capability of manufacturing plant-derived resins and biodegradable resins is inferred to improve every year. For example, Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2014-533164 (PTL 1) discloses that, with regard to the material of which a hook fastener is made, renewable biomass-derived bioplastics, such as cellulose or biopolymer, may be used. CITATION LIST Patent Literature PTL 1: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2014-533164 SUMMARY OF INVENTION Technical Problem Although PTL 1 exemplifies bioplastics as the material of a hook fastener, PTL 1 does not give any detailed information about, for example, the physical properties of bioplastics required for forming a hook fastener and the processing conditions of bioplastics. For example, as a synthetic resin of which a surface fastener is made, mixing a plant-derived resin or a biodegradable resin with a fossil-resource-derived resin and using this mixture is also being considered. However, in this case, due to, for example, the differences between the physical properties of the plant-derived resin or the physical properties of the biodegradable resin and the physical properties of the fossil-resource-derived resin, engaging elements of the surface fastener cannot be molded into a proper shape when two different types of resins are simply mixed. The present invention has been made in view of the problems above, and it is an object of the present invention to provide a surface fastener that can be formed by using a plant-derived resin and that includes a plurality of engaging elements engageable with loop members or the like, and a manufacturing method of manufacturing the surface fastener. Solution to Problem To this end, a surface fastener provided by the present invention is a surface fastener including: a base portion and a plurality of engaging elements that are provided on one surface of the base portion, each engaging element including a stem portion that extends upward from the base portion and an engaging head portion that is integrally formed with an upper end of the stem portion, in which the base portion and the engaging elements include a thermoplastic resin that at least partially includes a plant-derived resin, the plant-derived resin has a melt flow rate of 5 g/10 min or more and 30 g/10 min or less, and a flexural modulus of 800 MPa or more and 2300 MPa, and, in plan view of each of the engaging elements, the engaging head portion is such that at least a part of the engaging head portion has a shape that protrudes outward with respect to the upper end of the stem portion. It is preferable that, in the surface fastener of the present invention, each of the engaging head portions have a head-portion top end surface that faces upward, an outer peripheral side surface that inclines or curves downward from an outer peripheral edge of the head-portion top end surface, and a head-portion rear surface that is disposed between the outer peripheral side surface and the upper end of the stem portion: and a rear surface angle between a portion of the head-portion rear surface that extends from the upper end of the stem portion and an imaginary line that is extended downward from the upper end of the stem portion be less than or equal to 120 degrees. It is preferable that the thermoplastic resin include plant-derived polyethylene by a proportion of 25 parts by weight to 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin. It is preferable that the thermoplastic resin be formed from a mixture of plant-derived polyethylene and fossil-resource-derived polypropylene: the plant-derived polyethylene be includ