JPS6141742B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of a sheet-like foamed composite molded product that contains a large amount of inorganic powder and is lightweight and has excellent flexibility. More specifically, (a) gypsum dihydrate, (b) an emulsion-like thermoplastic resin and/or water-soluble polymer as a binder component, (c) an inorganic fibrous substance, (d) a blowing agent or an air-entraining agent, etc. An inorganic slurry containing a foaming agent as an essential component and other additives such as various reinforcing materials, pigments, plasticizers, anti-bacterial agents, etc. is formed as necessary, and this slurry is used alone or in combination with reinforcing materials. After forming into a sheet and drying,
It is related to the production of lightweight and flexible sheet-like foamed composite molded products by bending, and its objectives are to have excellent flame retardancy, flexibility, condensation resistance, heat insulation, It is an object of the present invention to provide a molded product that can be used as a building interior material such as a wall covering material, a ceiling material, a floor material, etc., and has excellent vibration-proofing properties, workability, and handling properties.

BACKGROUND OF THE INVENTION Among the various building interior materials conventionally used, resin sheets, cloth, nonwoven fabrics, processed paper, etc. containing a large amount of organic matter have problems with flammability, and there is a strong demand for them to be made nonflammable. On the other hand, gypsum boards, asbestos slate boards, etc. satisfy the requirements in terms of non-combustibility, but because they do not have flexibility, they have the disadvantage of being difficult to handle, that is, they cannot be bent. When used as a building interior material, it is necessary to bend the sheet material to match the uneven shape of walls and ceilings, but if the sheet material has low flexibility, cracks may occur at the bent portion. This will occur. Therefore, it can be said that it is extremely important for a sheet-like material to have bendability as a building interior material. Furthermore, gypsum board and asbestos slate have drawbacks such as lack of dew condensation resistance and water resistance. Furthermore, although sheet-like materials such as rock wool and asbestos are nonflammable and flexible, they are produced using a wet papermaking method that uses large amounts of water, resulting in long drying times and problems in production. many.

The present inventors have improved the flame retardancy of conventionally used wallpapers and decorative plywood, and created sheet-like foamed composite materials that are flexible, easy to handle, bendable, dew-proof, and water-resistant using a dry method. As a result of intensive research on a method that can be industrially and continuously produced at A sheet-like product obtained by forming an inorganic slurry containing as an essential component c) an inorganic fibrous material and (d) a foaming agent such as a blowing agent or an air-entraining agent into a sheet shape, either alone or together with a base material, and drying the The present invention has been completed by discovering that the above object is satisfied and that the molded product obtained by folding this sheet has no cracks at the folded portion.

In the present invention, since dihydrate gypsum is used, even if it is used in large quantities, it is difficult to mix it with other compounding components including the emulsion-like thermoplastic resin and/or water-soluble polymer, which are binder components. Slurry preparation using water can be easily carried out using water as a solvent, and in terms of product performance, it provides flexibility and flame retardancy, and these properties include heat insulation as well as incorporation into the sheet. This is further enhanced by the introduction of inorganic fibrous materials and microbubbles. Furthermore, the method of the present invention is industrially advantageous in that it uses a dry manufacturing method without requiring the use of large amounts of water and long drying times, as seen in the wet papermaking method of rock wool sheets, for example. It's advantageous.

In the present invention, gypsum dihydrate is used from the viewpoint of bending processability, flame retardant effect, and other performance aspects of the obtained sheet-like foamed composite material. As the dihydrate gypsum, any one obtained by any production method can be used, such as naturally occurring gypsum, phosphoric acid by-product gypsum, titanium by-product gypsum, and flue gas desulfurization by-product gypsum.

Examples of the thermoplastic resin emulsion used in the present invention include vinyl acetate polymer emulsion, acrylic polymer emulsion, vinyl chloride polymer emulsion, vinylidene chloride polymer emulsion, urethane polymer emulsion, and the like. Although vinyl acetate polymer emulsion is particularly preferred. In addition to vinyl acetate homopolymer emulsion, the vinyl acetate polymer emulsion used in the present invention includes, for example, vinyl acetate and ethylene, various acrylic acids, methacrylic acid, maleic acid, maleic acid esters, vinylversacic acid, and diacetone. Examples include copolymer emulsions with acrylamide, vinyl propionate, vinyl caproate, vinyl chloride, and the like. These thermoplastic resin emulsions can be used regardless of the emulsion obtained by any manufacturing method, and can be widely used without any restrictions on the type of emulsifier, solid content concentration, emulsion particle size, emulsion viscosity, etc. Can be used.

It is also possible to use a plasticizer if necessary. Vinyl acetate emulsion is the most suitable sheet-like foamed composite material for the purpose of the present invention because it has excellent physical properties such as weather resistance, heat resistance, blocking resistance, mechanical properties, and flexibility.

Examples of water-soluble polymers used in the present invention include polyvinyl alcohol polymers, polyvinyl pyrrolidone, polyvinyl methyl ether, polyvinyl acrylamide, sodium polyacrylate, polyethylene oxide, polyethylene imine, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and alginic acid. Soda, casein, glue, dextrin,
Examples include starch, α-starch, hydroxylethyl starch, gum arabic, gum tragacanth, water-soluble paper strength enhancers such as ketone aldehyde resin, polyamide resin, and melamine formaldehyde resin, but these water-soluble polymers cannot be used alone. Not only can they be used, but they can also be used in combination of two or more. Among these, polyvinyl alcohol polymers are mainly used as binders from the viewpoints of moldability, flexibility of the obtained sheet-like material, anti-condensation properties, and the like. Such polyvinyl alcohol-based polymers are generally polymers obtained by saponifying polyvinyl acetate and its various copolymers, or polymers obtained by graft polymerizing various monomers to polyvinyl alcohol. The water-soluble polymer, which usually has a degree of polymerization within the range of 500 to 3,500, is usually used in fiber processing, paper processing,
Any material used for pigment binders, emulsifying dispersants, adhesives, etc. can be used, but it must be water-soluble or dispersible in water, and must not require heating, drying, or PH.
It is required that it can be made insoluble in water by modification, addition of a crosslinking agent, etc.

Examples of the inorganic fibrous material used in the present invention include rock wool (natural rock wool or mineral wool), asbestos, and glass fiber. Rock wool is most preferred as it imparts soft properties to the sheet, but other materials may be used alone or in combination.

The foaming agents used in the present invention include evaporative foaming agents such as ethanol, toluene, and heptane, and decomposition foaming agents such as sodium bicarbonate, ammonium carbonate, azobisisobutyronitrile, and paratoluenesulfonylhydrazide. Air entraining agents such as blowing agents and surfactants such as polyvinyl alcohol, sodium stearate, and polyethylene glycol monolaurate are used.

In addition, in the method of the present invention, if necessary in relation to the use of the final product, for example, when water resistance is particularly required, crosslinking agents for the various polymers constituting the binder component may be added to In such cases, a plasticizer is added to the slurry, and in cases where coloring and prevention of mold growth are required, pigments and anti-bacterial agents are appropriately added to the slurry. Preferred formulations for practicing this invention generally include 60 to 99 parts of dihydrate, preferably 70 to 90 parts of gypsum;
40 to 1 part of binder polymer, preferably 30 to 1 part
10 parts, the inorganic fibrous material is 2 to 50 parts, preferably 6 to 12 parts, and the slurry moisture during kneading is 20 to 60%, preferably 40 to 55%, but depending on the physical properties of the intended sheet. It is fixed and there are no restrictions.

The inorganic slurry prepared as described above is formed into a sheet by conventional methods such as extrusion or casting. As the reinforcing material used when molding, for example, a sheet-like base material such as a woven fabric, a non-woven fabric, paper, or a wire-like material can be used.

The slurry liquid formed into a sheet is dried to remove moisture. The dried sheet-like material is bonded to a metal plate, if necessary, and then bent. In the present invention, since gypsum dihydrate is used as the inorganic powder, the sheet material hardly cracks or cracks during processing.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples in any way.

Example 1 Polyvinyl alcohol (saponification degree 80%, polymerization degree
2000) 115 parts of a 10% aqueous solution, 30 parts of water, 3.83 parts of a 30% aqueous solution of potassium hydroxide (1st class reagent), 0.863 parts of sodium bicarbonate (1st class reagent), water-soluble ketone aldehyde resin (Detsu Harkyures Co., Ltd. ) 3.29 parts (trade name: Epinox P468) manufactured by ) were sequentially added and mixed while stirring. Next, 2.3 parts of glycerin (grade 1 reagent) and 0.82 parts of cationic special polyamide resin (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumiretsu Resin 650-30) were added, followed by 12 parts of Rotsukur (manufactured by Nippon Steel Chemical Co., Ltd.). and 76 parts of gypsum dihydrate (a byproduct of flue gas desulfurization using the slaked lime process) are added, stirred and mixed at high speed, and air is mixed in to foam the slurry to a specific gravity of 0.4, which is then cast onto a carrier sheet. It was dried for 60 minutes in a dryer at 130°C. The physical properties of the obtained sheet are 4 mm in thickness and 0.20 in specific gravity.
g/cm ³ , a dimensional change of 1% after immersion in water for 24 hours, a water retention capacity of 300 g/m ² , and could be rolled up. When this sheet was attached to an iron plate and bent, a molded product was obtained without cracking or cracking. In addition, by pasting chloroprene adhesive on a 0.6 mm thick color iron plate, we applied the Ministry of Construction Notification No. 1828 of 1971 and the Ministry of Construction Notification No. 3415 of 1960.
As a result of testing using the fire protection material testing method pursuant to No. 1, it was recognized as a noncombustible material.

Example 2 Polyvinyl alcohol (saponification degree 80%, polymerization degree
2000) 0.175 parts of 10% aqueous solution and 10% aqueous solution of polyvinyl alcohol (saponification degree 90%, polymerization degree 1700)
Add 0.912 parts of water to 0.030 parts, and while stirring with a kneader, add 0.72 parts of Rock Wool (Nippon Steel Chemical Co., Ltd.) and 2.64 parts of gypsum dihydrate (a byproduct of flue gas desulfurization using the slaked lime method) and mix. This slurry is mixed with 0.888 parts of water, 0.030 parts of cationic special polyamide resin (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumiretsu Resin 650-30), and vinyl acetate-ethylene-acrylic acid copolymer emulsion (Pamphrex OM7000 solid, manufactured by Kuraray Co., Ltd.). Add 1,158 parts of (49.5% by weight) and mix uniformly, stir vigorously to stir in air and foam to make the slurry specific gravity 0.5. Cast this onto a carrier sheet and dry at 100℃ for 60 minutes. did. The physical properties of the obtained sheet were: thickness 4 mm, specific gravity 0.3 g/cm ³ , dimensional change after 24 hours immersion in water 0.5%, water holding capacity 200 g/m ² ,
It was possible to wind it up. When this sheet was attached to a steel plate and bent, it cracked.
A molded product was obtained without cracking. Also, as in Example 1, the result of the fire resistance test was that it was recognized as a noncombustible material.

Claims (1)

[Claims] 1. Contains (a) gypsum dihydrate, (b) emulsion-like thermoplastic resin and/or water-soluble polymer, (c) inorganic fibrous material, and (d) foaming agent. 1. A method for producing a sheet-like foamed composite molded product, which comprises forming a slurry alone or in combination with a reinforcing material into a sheet, drying it, and bending the obtained sheet-like product. 2 Ethylene as a thermoplastic resin emulsion
The manufacturing method according to claim 1, which uses a vinyl acetate copolymer emulsion. 3. The manufacturing method according to claim 1, wherein a polyvinyl alcohol polymer is used as the water-soluble polymer. 4. The manufacturing method according to claim 1, wherein rock wool is used as the inorganic fibrous material.