JPS6316421B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a compressed porous material made of a foam such as polyurethane.

[Conventional technology]

Generally, when manufacturing a foam, the foaming agent and foaming ratio are set in advance at the time of molding to obtain a desired foaming ratio.

That is, a method is used in which conditions are set before finishing the material as a porous material, and a foam having a desired foam density is manufactured based on the conditions. A typical example of this method is cast molding.

[Problem that the invention seeks to solve]

However, with the above-mentioned method of setting the foaming agent and machine conditions before the foaming process, it is necessary to create a mold for molding according to the conditions, which requires a lot of expense and effort. There are many.
In addition, there are many disadvantages in that it takes many days to find the optimum conditions in terms of equipment. In addition,
The above molding method also has the disadvantage that it requires considerable skill. Furthermore, in terms of quality, it is very difficult to obtain a foam with multiple functions and a desired density using the methods described above.

For example, in order to provide urethane foam with a strong water-absorbing and water-retaining function as well as a flexible and elastic function, the above-mentioned method involves blending a water-absorbing material with a foaming agent into a urethane resin and foaming the resin. However, in order to obtain a foam with a desired density, that is, a desired expansion ratio by blending a water-absorbing material, delicate control is required at the time of foaming, and as a practical matter, it is very difficult to obtain a foam with a desired expansion ratio. It is difficult to

In addition, if a flexible and elastic foam can be provided with polishing and oil-absorbing functions in addition to the above-mentioned strong water-absorbing and water-retaining functions, it can be used as wipes, cosmetic applicators, sanitary materials, clothing miscellaneous goods, etc. An extremely wide range of applications can be expected.

[Purpose of the invention]

The present invention was developed in view of the above-mentioned problems, and its purpose is to create a compressed porous foam with a desired apparent density by post-processing a flexible foam made of a single material. The purpose of the present invention is to provide a quality material, and also to make it possible to provide a foam with desired functions.

[Means for solving problems]

According to the present invention, the above object is achieved by providing a foam having air permeability, in which a synthetic resin is attached to the skeletal surface of the foam, and the foam is fixed in a compressed state by the synthetic resin. This is achieved using a compressed porous material that is characterized by

[Operation] The basic method for producing the compressed porous material of the present invention is as follows.

On the surface of the skeleton of open-cell foams such as polyester-based or polyether-based urethane or other breathable foams, thermoplastic resins with a melting point lower than that of the skeleton material or blocked isocyanates, etc. After impregnating or applying a synthetic resin raw material with an adhesive function by heating and dissociation, it is dried. Next, a single powder or granule having hot-melt properties such as nylon or ethylene-vinyl acetate copolymer smaller than the pore size of the foam, or an organic or granular material such as sponge powder, leather powder, calcium carbonate powder, wood powder, etc. After a mixture of inorganic powder and granules is deposited into the pores of the foam by a method such as vibration or scattering, or together with a solution medium, the mixture is heated and compressed to give the foam a desired apparent density.

In other words, a reactive or meltable strongly adhesive material is attached to the skeletal skin part of the foam finished at a density lower than the desired density, and only hot-melt granular material having an adhesive function is used. Alternatively, powder and granules of a material having a desired function are attached to a foam together with hot-melt powder, and the density of the foam is increased to a desired density by heating and compression. In addition, when granules of a material having desired functions are added, a modified foam having functions such as water absorption and abrasive properties can be obtained by these granules.

〔Example〕

Hereinafter, the present invention will be explained in detail based on Examples. It goes without saying that the present invention is not limited to these examples.

Example 1 A polyester polyurethane foam sheet with an expansion ratio of 8 times and a thickness of 6 mm was prepared by adding 2% of phenol-blocked methylene bis-4 phenyl isocyanate and dibutyltin dilaurate.
It was immersed in a 1:1 mixture of 0.1% methyl ethyl ketone (MEK) and methyl alcohol, removed to a 50% reduction, and then dried at 60°C. Next, nylon resin powder with a melting point of 120°C and passed through 100 meshes and sponge powder passed through 100 meshes were mixed in a ratio of 3:1.
A mixture mixed at a ratio of 100 to 100% was spread onto the polyurethane foam sheet, and was vibrated on a diaphragm to adhere as uniformly as possible within the holes of the foam sheet. Next, the plate surface of the press plate was heated and compressed for about 5 minutes at a thickness of 4 mm using a press machine set at 180°C to form a flexible, elastic and water-absorbing sheet with a fixed thickness of 4 mm. Obtained.

Example 2 A polyester polyurethane foam sheet with an expansion ratio of 8 times and a thickness of 6 mm was prepared by adding 2% of phenol-blocked methylene bis-4 phenyl isocyanate and dibutyltin dilaurate.
It was immersed in a 1:1 mixture of 0.1% methyl ethyl ketone (MEK) and methyl alcohol, removed to a 50% reduction, and then dried at 60°C. Next, nylon resin powder with a melting point of 120°C and passed through 100 meshes and sponge powder passed through 100 meshes were mixed in a ratio of 3:1.
A mixture mixed at a ratio of 100 to 100% was spread onto the polyurethane foam sheet, and was vibrated on a diaphragm to adhere as uniformly as possible within the holes of the foam sheet. Next, the press plate with the corrugated surface was pressed to a thickness of 4 mm using a press set at 180°C.
The sheet was heated and compressed for about 5 minutes to obtain a sheet having a fixed thickness of 4 mm and having corrugations on the surface, which was flexible, elastic, and water absorbent.

Example 3 A polyurethane foam with a foaming ratio of 12 times and a thickness of 35 mm was mixed with dimethyl hydroxyethylene urea (Betsukamine NF-1 manufactured by Dai-Nippon Ink Co., Ltd.) in an amount of 7% of the weight of the urethane foam, and magnesium chloride in an amount of 7% of the weight of the urethane foam. After impregnating it in an aqueous solution to a concentration of 0.7% of the weight, it is dehydrated to a concentration of 50%.
Dry at 80°C. Next, appropriate amounts of vinyl chloride/vinyl acetate copolymer resin powder, calcium carbonate powder passed through 50 meshes, and CMC (carboxymethyl cellulose) crosslinked product powder are mixed, sprinkled on the polyurethane foam, and shaken to form a foam. It was attached inside the hole. Next, the board surface temperature is 180℃
The sheet was set to a thickness of 10 mm using a press machine, and heated and compressed for 7 minutes to obtain a compressed porous sheet with a thickness of 10 mm, which was flexible, had water absorption properties, and had a rough surface.

In Examples 1 and 2, the blocked isocyanate adhering to the porous skeletal skin part dissociates and reacts in the final heat-compression step, resulting in a skeletal adhesion phenomenon.
At the same time, the hot-melt powder acts to bond the modifier in the pores.

Furthermore, in Example 2, the uneven pattern on the surface of the press plate was transferred to the surface of the foam.

In Example 3, hot-melt resin and hot-melt powder adhere to the skin of the skeleton and inside the pores, but the same effects as in Examples 1 and 2 are achieved.

In the above embodiments, urethane foam was particularly used, but other foams can be treated in the same way by appropriately selecting the adhesive and the powder for modification.

The following resins are preferred as the resin to be attached to the skeletal skin.

As for the reaction type, phenol or 3
Various compounds containing two or more functional isocyanate groups blocked with an alcohol are suitable.

In addition, good examples of resins that melt at low temperatures include nylon, EVA (ethylene vinyl acetate), polyester, acrylic, and polyurethane resins.

Further, as the powder or granular material used for adhesion, the following are preferable.

When the purpose is reinforcement, that is, improvement in strength, resin powders such as nylon, polyester, acrylic, polyurethane EVA (ethylene vinyl acetate), etc. are suitable.

As the modifier to be mixed with these synthetic resin powders, calcium carbonate powder, silicon oxide powder, Teflon powder, etc. may be mixed in order to improve the abrasiveness.

Furthermore, when increasing water absorption and water retention, super water absorption and water retention materials such as crosslinked products of CMC (carboxymethyl cellulose), alkali metal carboxylate salts of starch polyacrylonitrile graft polymers,
Sponge, vinylon, rayon powder, etc. are also good. These inorganic and organic powders also have an oil-absorbing effect.

In addition, in order to improve the appearance or feel of the obtained foam, it is preferable to mix and blend wood flour, horsehide, cowhide, or various synthetic leather powders, etc. As a result, a foam suitable for use in clothing and miscellaneous goods etc. can be obtained.

By using the powders as described above in combination with the materials of Examples 1 and 2 described above, the materials were provided with water absorbency in addition to elastic flexibility, and the strength of the materials was also improved. As a result of making this material into a cosmetic puff, it has elasticity, flexibility,
An excellent product with unprecedented functions such as water absorption and strength was obtained. Furthermore, this material could also be used in the field of sanitary materials such as diaper covers for children.

Furthermore, by blending inorganic powder and a water-absorbing agent with the above-mentioned Example 3, it became possible to apply it widely in the field of miscellaneous goods such as wiping tools and cleaning tools.

Furthermore, it can be used as an acoustic material because it can be easily varied in terms of acoustics by partial compression and compression of surface unevenness patterns.

〔Effect of the invention〕

As described above, according to the present invention, a compressed porous material having a desired foam density can be obtained by post-processing a foam. Furthermore, the compressed porous material of the present invention is easy to manufacture and can be easily produced in small quantities, thereby saving equipment and costs.

In addition, a modifier can be attached to the foam without sacrificing the advantage of flexibility and elasticity that the foam has, and it is also possible to achieve desired quality with high added value. The compressed porous material of the present invention can be modified in various ways by appropriately selecting the modifying material, and can be used in a wide variety of fields such as clothing, laundry goods, cosmetic tools, sanitary materials, and acoustic materials. This will greatly contribute to the development of the industry.

Claims (1)

[Claims] 1. A compressed porous material having air permeability, characterized in that a synthetic resin is attached to the skeletal surface of the foam, and the foam is fixed in a compressed state by the synthetic resin. .