JPS6142623B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing 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 of requiring 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 provide a foam with a desired apparent density by post-processing a flexible foam made of a single material. Another object of the present invention is to provide a method that allows a foam to have desired functions.

[Means for solving problems]

In the present invention, the above object is achieved by attaching a synthetic resin liquid or a synthetic resin raw material liquid to an air-permeable foam, and then drying the foam, and then applying a thermoplastic synthetic resin smaller than the pore diameter of the foam to the foam. This is achieved by a method for manufacturing a compressed porous material, in which a powder is attached and then a fixation process is performed while heating and compressing at a temperature intermediate between the melting points of the foam and the synthetic resin powder.

[Effect]

To describe the basic structure of the present invention, heat having a melting point lower than that of the skeleton material is applied to the surface of the skeleton of an open-cell foam such as polyester-based or polyether-based urethane or other breathable foam. After impregnating or applying a synthetic resin raw material such as a plastic resin or blocked isocyanate that has 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 having a smaller pore size than the pore size of the foam, or the powder and granule together with sponge powder, skin powder, calcium carbonate powder,
A mixture of organic or inorganic powder such as wood powder is deposited into the pores of the foam by vibration or scattering, or together with a solution medium, and then heated and compressed to form the foam into the desired shape. 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.
The mixture mixed in the proportions of 1 to 3 was spread on 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 surface of the pressed plate with the corrugated surface was heated and compressed for about 5 minutes to a thickness of 4 mm using a press machine set at 180°C to form a flexible sheet with a fixed thickness of 4 mm and a corrugated surface. A sheet having elasticity and water absorbency was obtained.

Example 2 A polyurethane foam with an expansion 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 with magnesium chloride in an amount of 7% by 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 Example 1, the block isocyanate adhering to the porous skeletal skin dissociates and reacts in the final heat compression process, resulting in a skeletal adhesion phenomenon. It acts to bond the modified materials. In this example, the uneven pattern on the surface of the press plate is transferred to the surface of the foam.

In Example 2, hot-melt resin and hot-melt powder are adhered to the skin of the skeleton and inside the pores, but the same effects as in Example 1 can be 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, low-temperature melting resins include nylon,
Good materials include EVA (ethylene vinyl acetate), polyester, acrylic, and polyurethane resin.

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

For reinforcement, that is, to improve strength, use nylon, polyester, acrylic, polyurethane EVA (ethylene vinyl acetate)
Resin powder and granules such as .

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, CMC
(carboxymethylcellulose) crosslinked product,
Super-absorbent and water-retentive materials such as alkali metal carboxylate salts of starch polyacrylonitrile graft polymers, sponges, vinylon, rayon powders, etc. are also suitable. 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 granular material in combination with the material of Example 1, the material 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 a water absorbing agent into the above-mentioned Example 2, 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 method of the present invention, a desired foam density can be easily achieved by post-processing the foam. Moreover, the method of the present invention can be easily carried out even in small quantities, and equipment and costs can be saved. Furthermore, by using a modifying material, it is possible to obtain a desired quality with even higher added value without impairing the advantage of flexibility and elasticity that the foam has. In the method of the present invention, various modifications can be made by selecting the modification material, and various modifications can be made to clothing, laundry miscellaneous goods,
It can be used in a wide variety of fields such as cosmetic tools, sanitary materials, and acoustic materials, and will greatly contribute to the development of the industry.

Claims (1)

[Claims] 1. A synthetic resin liquid or a synthetic resin raw material liquid is attached to an air-permeable foam, and then dried, and thermoplastic synthetic resin powder particles smaller than the pore diameter of the foam are attached to the foam, and then the A method for producing a compressed porous material, characterized in that a fixing treatment is performed while heating and compressing at a temperature intermediate between the melting points of a foam and a synthetic resin powder.