JPH0639542B2 - Method for producing fragrant olefin resin foam - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an olefin resin foam having a scent.

[Conventional technology]

It is sometimes preferred to add a scent to the olefin resin foams used in toilet mats, bath mats and other applications.

By the way, in the crosslinked foam of olefin resin,
A blowing agent that decomposes at a relatively high temperature such as azodicarbonamide is used during the production, and the fragrance is easily sublimated, and the fragrance activated during cross-linking and foaming is easily sublimated and scattered through the polyolefin film.

Therefore, there has been proposed a method of impregnating and adsorbing a fragrance into an inorganic porous granular material and mixing or interposing the fragrance into a synthetic resin foam (Japanese Patent Laid-Open No. 54-30261).

[Problems to be solved by the invention]

In the above-mentioned method, since the perfume-containing inorganic porous granular material is interposed and fused between two polyethylene foam sheets that have been once foamed, the manufacturing is complicated and the obtained There is a drawback that the shape of the fragrant polyethylene foam is limited.

This invention is made for the purpose of economically obtaining a fragrance-retaining polyolefin resin foam by first forming a foam and then adding the fragrance to the foam without mixing the fragrance during the foam molding without escaping. It is a thing.

[Means for solving problems]

The method for producing a fragrance-retaining olefin resin foam of the present invention comprises adding a fragrance and a silanol catalyst to a silane-grafted polyethylene or a resin mainly composed of a silane-grafted polyethylene, and mixing and melting the mixture with a gaseous foaming agent in an extruder. It is characterized in that it is extruded and foamed from a mold held at a temperature of 120 ° C. or lower, and then this extruded foam is crosslinked.

In this invention, a silane-grafted polyethylene alone or a polyolefin-based resin mainly composed of silane-grafted polyethylene is used as the polyolefin resin.

Silane-grafted polyethylene is, for example, Japanese Patent Publication No. 48-
It can be obtained by the method described in Japanese Patent Publication No. 1711, Japanese Patent Publication No. 57-26696, Japanese Patent Publication No. 58-9594.

Further, the silanol catalyst is a substance such as an organic metal compound such as dibutyltin dilaurate or stannous acetate as described in the above publication.

As the gaseous foaming agent, vinylidene fluoride known as Freon, tetrafluoroethylene, trifluoroethylene chloride, or the like or a mixed gas thereof is used, and the dose and the method of use are not particularly different from the conventional ones.

The temperature of the die attached to the extruder needs to be 120 ° C. or lower, and it is desirable to make the temperature as low as possible according to the resin used. Cross-linked Cross-linking of this foam is also possible with steam, high-temperature water, etc., but in this invention steam and high-temperature water etc. are subjected to high-temperature treatment and the fragrance tends to dissipate.
It is recommended to crosslink by the action of the moisture in the air and the silanol catalyst in the foam by so-called aging in the air for one to several days.

[Action]

In the method of the present invention, silane-grafted polyethylene is extruded and foamed, and then cross-linked at a relatively low temperature by performing it in the presence of a silanol catalyst and water, and the foaming is also performed at 120 ° C. attached to the tip of the extruder. Since it will be extruded and foamed from the following mold, since sublimation and escape of the fragrance can be suppressed, a crosslinked foam of aromatizing olefin resin can be produced by an apparatus which is the same as the conventional olefin resin foam molding process. .

〔Example〕

Perfume 2 in which 0.2 parts by weight of a nucleating agent and 100 parts by weight of a master batch were preliminarily added to 100 parts by weight of bluffed low density polyethylene.
Part into a dandem type extruder, and while melt-kneading with a single-stage extruder, about 20 parts by weight of Freon gas (F-114) was press-fitted into the extruder, and the tip of the extruder was heated to about 100 ° C. and the mold tip temperature was changed. Cooled to 95 ° C and extruded and foamed to give a density of 30 g /
A foamed sheet of cm ³ was obtained.

This foamed sheet was left in the atmosphere for 24 to 48 hours to be crosslinked.

The foamed sheet was heated in an oven at 120 ° C. for about 1 minute, and then cold pressed to form a cushion material for head gear of ice hockey.

It was found that this cushioning material for headgear overcomes the odor of sweat, emits a pleasant scent, and has a good aroma retaining property.

〔The invention's effect〕

According to the present invention, the silane-grafted polyethylene is extruded and foamed, and then the crosslinking is carried out at a relatively low temperature by performing it in the presence of a silanol catalyst and water, and the foaming is performed at a temperature of 120 ° C. or lower attached to the tip of the extruder. Since it is to be extruded and foamed from the mold, the sublimation of the fragrance can be suppressed.

Therefore, the crosslinked foam of the fragrance-retaining olefin resin can be easily produced by the same apparatus as the conventional foam molding process of the olefin resin.

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Claims (1)

[Claims] 1. Gold containing fragrance and silanol catalyst added to silane-grafted polyethylene or a resin mainly composed of silane-grafted polyethylene, which is mixed and melted with a gaseous foaming agent in an extruder and kept at a temperature of 120 ° C. or lower. A method for producing a fragrance-retaining olefin resin foam, comprising extruding foam from a mold and then cross-linking the extruded foam.