JPS61258843A - Compressed porous material - Google Patents

Abstract

PURPOSE:A compressed porous material, obtained by fixing a foam having air-permeability in a compressed state with a synthetic resin sticking to the skeleton surface of the foam, and capable of adjusting the foaming density and various modifications without deteriorating flexibility and elasticity. CONSTITUTION:A compressed porous material obtained by impregnating or coating the skeleton skin part of an open-cell foam, e.g. polyester based or polyether based urethane and finished to a lower density than the desired value with a thermoplastic resin having a lower melting point than the skeleton material or a synthetic resin raw material, e.g. blocked isocyanate, having bonding function by heating or dissociation, and dried. A hot-melt powdery or granular material, e.g. nylon, having a smaller size than the pore diameter of the foam or a mixture thereof with a powdery or granular material of a material having the desired function, e.g. sponge powder, is applied to the interior of pores in the foam by vibration or scattering, etc., and the resultant foam is compressed while heating to afford the aimed foam having the desired density.

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, a foaming agent and a 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 a cast molding method.

[Problem that the invention seeks to solve]

However, as mentioned above, the method of setting the foaming agent and machine conditions before the foaming process requires creating a mold for molding according to the conditions, which requires a lot of expense and labor to create the mold. 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 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
The purpose is to provide a compressed porous material with a desired apparent density of the foam by post-processing a single flexible foam, and also to provide the foam with the desired functionality. The purpose is to make it possible to have the following.

[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

(Function) 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 or plotted isocyanates, which have a melting point lower than that of the skeleton material, are added. After impregnating or applying a synthetic resin raw material having an adhesion ability by heating and dissociation, drying is performed. Next, a hot-melt powder such as nylon or ethylene-vinyl acetate copolymer having a smaller pore size than the foam, or an organic material such as sponge powder, leather powder, calcium carbonate powder, wood powder, etc. Alternatively, a mixture with inorganic powder or granules is deposited into the pores of the foam by vibration or scattering, or together with a solution medium, and then 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 to a density lower than the desired density, and a hot-melt powder or granule material having an adhesive function is added. Powder or granules of a material having a desired function are attached to the foam either alone or together with hot-melt powder, and the density of the foam is increased to the 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 described in detail based on Examples.

It goes without saying that the present invention is not limited to these examples.

[Example 1] A polyester-based polyurethane foam sheet with an expansion ratio of 8 times and a thickness of 5 Im was prepared using methyl ethyl ketone (MEK) containing 2% phenol-blocked methylene bis 4 phenyl isocyanate and 0.1% dibutyltin dilaurate. Immerse in a 1=1 mixture of
It was dried. Next, a mixture of 100-mesh nylon resin powder with a melting point of 120°C and 100-mesh sponge powder mixed in a ratio of 3:1 was sprinkled on the polyurethane foam sheet and vibrated on a diaphragm. The film was then deposited as uniformly as possible within the holes of the foam sheet.

Next, the plate surface of the press plate was heat-compressed for about 5 minutes at a thickness of 4I using a press machine set at 180°C to form a flexible, elastic and water-absorbing sheet with a fixed thickness of 4mm. Obtained.

[Example 2] A polyester-based polyurethane foam sheet with an expansion ratio of 8 times and a thickness of 6II 1 m was prepared using methyl ethyl ketone (MEK) containing 2% of phenol-blocked methylene bis 4 phenyl isocyanate and 0.1% of dibutyltin dilaurate. After soaking in a 1:1 mixture of methyl alcohol and methyl alcohol and removing the liquid to a 50% reduction,
It was dried at 0°C. Next, a mixture of 100-mesh nylon resin powder with a melting point of 120'C and 100-mesh sponge powder mixed in a ratio of 3=1 was sprinkled on the polyurethane foam sheet and placed on the diaphragm. It was vibrated to adhere as uniformly as possible within the holes of the foam sheet. Next, the plate surface of the press plate with a corrugated surface was
A press machine set at 0° C. was used to heat and compress the sheet to a thickness of 411ffi for about 5 minutes to obtain a sheet having a fixed thickness of 4Im and having corrugations on the surface, which was flexible, elastic, and water absorbent.

[Example 3] A polyurethane foam with an expansion ratio of 12 times and a thickness of 35III11 was mixed with dimethyl hydroxyethylene urea (Beckamin NF-1 manufactured by Dai-Nippon Ink Co., Ltd.) at 7% of the weight of the urethane foam, and magnesium chloride at 7% of the weight of the urethane foam. The foam was impregnated with an aqueous solution to a concentration of 0.7% of the weight of the foam, then drained to a 50% reduction and dried at 80°C.

Next, appropriate amounts of vinyl chloride/vinyl acetate copolymer resin powder, calcium carbonate powder that has 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. Then the plate surface temperature is 180
Set the thickness to 10III11 using a press machine at ℃ 7
The mixture was heated and compressed for minutes to obtain a compressed porous sheet having a thickness of 10111111 mm, flexible, water-absorbing, and having a rough surface.

In Example 1.2, 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 Example 1.2 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, various compounds containing an isocyanate group having two or more functional groups that have been blocked in advance with phenol or tertiary alcohol are suitable.

In addition, resins that melt at low temperatures include nylon, EV
A (ethylene vinyl acetate), polyester,
Acrylic, polyurethane resin, etc. are good.

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

When the purpose is reinforcement, that is, improvement of strength, nylon, polyester, acrylic, polyurethane EVA
Resin powder such as (ethylene vinyl acetate) is good.

Modifiers to be mixed with these synthetic resin powders include calcium carbonate powder,
It is good to mix silicon oxide powder, Teflon powder, etc.

Furthermore, in order to increase water absorption and water retention, super water absorption and water retention materials such as crosslinked products of CMG (carboxymethyl cellulose), alkali metal carboxylate salts of starch polyacrylonitrile graft polymers, sponge, vinylon, rayon powder, etc. may also be used. . 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 above-mentioned powder together with the material of Example 1.2 described above, it was provided with water absorbency in addition to elastic flexibility, and the strength of the material was also improved. As a result of making this material into a cosmetic puff, we were able to obtain an excellent product with unprecedented functions such as elasticity, flexibility, water absorption, and strength. Furthermore, this material could also be used in the field of sanitary materials such as diaper covers for children.

Further, by blending inorganic powder and water absorbing agent into 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. In addition, the compressed porous material of the present invention is easy to manufacture and can be easily produced in small quantities.
You can also save money.

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 foam 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. material.