JPH0929720A - Thermoplastic cement molding and molding method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expedite curing of cement particles by facilitating the impregnating of water at the time of curing by the bubble of a molding. SOLUTION: 100 pts. thermoplastic resin, 50 to 600 pts. cement, 0.1 to 20 pts. hydrophilic alloy agent, 10 to 30 pts. foaming agent and 80 to 400 pts. water are kneaded, and low-pressure molded while being heated. The gelling and hydration of the mixture proceed by heating, and hence a thermoplastic cement molding having foams on the surface and in the interior is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic cement molding and a molding method thereof.

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open No. 7-10626, filed on January 13, 1995, discloses a method of kneading a thermoplastic resin and a hydraulic or pneumatic cement to obtain a cement molded product. ing. In this conventional technique, one is considered as a matrix and the other as a filler for molding. When the thermoplastic resin is considered as the matrix, it is formed by gelling the resin. When cement is considered as a matrix, it is molded and hardened by adding water. This conventional technique employs a method of adding cement in which a thermoplastic resin and a hydrophilic substance are compatibilized in order to supply water necessary for curing.

[0003]

The conventional technique for supplying water necessary for hardening cement by a hydrophilic substance may not be able to supply a sufficient amount of water.
An uncured part may remain inside the molded product. In that case, a problem occurs in terms of strength of the molded product.

Therefore, a main object of the present invention is to provide a method for molding a thermoplastic cement which can be cured efficiently as a whole. Another object of the present invention is to provide a molded body molded according to such a novel method.

[0005]

The present invention foams and molds a mixed material of a thermoplastic resin, cement and a foaming agent,
This is a method for molding a thermoplastic cement.

[0006]

[Function] By foam molding the above mixed material,
Open cells are formed in the molded body. Therefore, after molding,
When curing with water or steam, water easily penetrates from the outside, and the hardening of cement particles is promoted.

[0007]

EFFECTS OF THE INVENTION According to the present invention, since continuous cells are formed in the molded body, sufficient water is supplied not only to the surface of the molded body but also to the inside of the molded body during curing. Can be made. The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments.

[0008]

EXAMPLES The thermoplastic resin usable in the present invention means all resins other than thermosetting resins, and may be a mixture of two or more kinds of resins or a copolymer. Further, not only the new resin but also the waste resin may be used. For example, asphalt, PE
(Polyethylene), PP (Polypropylene), PVC
(Vinyl chloride), EVA (ethylene vinyl acetate), ABS (acrylonitrile-butadiene-styrene copolymer), AAS (acrylonitrile-acrylic rubber-styrene copolymer), AES (acrylonitrile-
EPDM-styrene copolymer), ACS (acrylonitrile-chlorinated polyethylene-styrene copolymer), MB
S (methyl methacrylate-butadiene-styrene copolymer), E-PVC, vinylidene chloride, chlorinated olefin butadiene, polyacetal, nylon, PET (polyethylene terephthalate), PC (polycarbonate), PS (polystyrene), PMMA (polymethyl) Methacrylate), PBT (Polybutylene terephthalate), PPE (Polyphenylene terephthalate), PAR
(Polyarylate), LCP (Liquid Crystal Holima), PTF
Examples thereof include E (polytetrafluoroethylene), PEK (polyether ketone), PEEK (polyether ether ketone), and PES (polyether sulfone).

Further, a urethane type thermoplastic elastomer, a styrene type thermoplastic elastomer, an olefin type thermoplastic elastomer, a polyester type elastomer, a polyamide type elastomer, a polybutadiene type elastomer, a vinyl chloride type elastomer or the like may be used. Furthermore, in rubber type, natural rubber, SBR (styrene butadiene rubber),
BR (butadiene rubber), IR (isoprene rubber), C
R (chloroprene rubber), NBR (acrylonitrile-
Butadiene rubber), EPM (ethylene-propylene rubber), or IIR (isobutylene-isoprene rubber).

Cement which can be used in the present invention is hydraulic cement or air-hardening cement. As hydraulic cement, not only ordinary Portland cement (normal cement), blast furnace cement, fly ash cement, white cement, and other Portland cement-based cement, but also hain-based ultra-fast cement, alumina cement,
There are hydraulic cements such as dental cement, oxychloride cement, acid resistant cement and gypsum. However, active silica and calcium hydroxide, which are composed of two or more components and react with water to form hydraulic cement,
Activated alumina and calcium hydroxide are also included.

Examples of the air-hardening cement include lime and magnesia cement, as well as air-hardening carbonic acid hardened materials such as calcium hydroxide, dolomite plaster, and metal powders hardened by oxidation, such as iron powder and zinc powder. If necessary,
In this invention, a hydrophilic alloy agent is used. The hydrophilic alloying agent is a substance for imparting hydrophilicity to the thermoplastic resin, and is a substance for dispersing or dissolving the thermoplastic resin in the thermoplastic resin to impart hydrophilicity and air permeability to the thermoplastic resin.

As an example, a polyolefin oxide such as polyethylene oxide or polypropylene oxide, a polyhydric alcohol such as PVA (polyvinyl alcohol) or polyethylene glycol, or a mixture of two or more kinds thereof, or a copolymer thereof, PPG (polypropylene glycol). ) Containing, for example, a polyurethane prepolymer or a nonionic surfactant and polyoxyethylene alkyl ethers as a raw material thereof and polyoxyethylene alkyl ethers of polyhydric alcohol, polyethylene glycol fatty acid ester, ester of polyhydric alcohol The kind is mentioned.

The hydrophilicity can be imparted to the thermoplastic resin even if the superabsorbent polymer is powder-mixed with the thermoplastic resin. That is, since substances that have become superabsorbent polymers are generally incompatible with thermoplastic resins and insoluble in organic solvents, they have a weak effect of modifying the thermoplastic resin interface, but one of the synthetic raw materials is By powder-mixing with a resin and adding the other to the thermoplastic resin directly or by dissolving as a compatibilizer, similar to polyolefin oxide,
The interface of the thermoplastic resin can be modified.

For example, starch-acrylonitrile graft polymer, starch-anocrylic acid graft polymer, starch-
Styrene sulfonic acid graft polymer, starch-vinyl sulfonic acid graft polymer, starch-acrylamide graft polymer, starch-polyvinyl ketone polymer, cellulose-acrylonitrile graft polymer, cellulose-styrene sulfonic acid graft polymer, other starch derivatives , Natural products such as hiruaroic acid, agarose, chitosan, collagen, PVA cross-linked polymer of synthetic polymer, PV
A elastomer, acrylic acid cross-linked polymer, acrylic acid ester-vinyl acetate copolymer partial hydrolyzate, acrylic acid salt-PVA copolymer, polyacrylonitrile polymer partial hydrolyzate, hydroxyethyl methacrylate polymer, anhydrous Examples thereof include isobutylene maleic acid copolymer salt, vinyl virovidone copolymer or polymer, polyethylene glycol-diacrylate copolymer, polypropylene glycol-diacrylate copolymer, and polyethyleneimine copolymer. However, these are either alone or 2
It may be a mixture of more than one species.

Further, when the hydrophilic alloying agent is added to the thermoplastic resin, a compatibilizing agent is used, if necessary, as a compatibilizing aid. This compatibilizing agent, in addition to the compatibilizing agent for usual polymer alloy, is compatible with the hydrophilic alloying agent,
A substance which is compatible with a thermoplastic resin and which itself is a hydrophilic substance and exhibits hydrophilicity and oil solubility, for example, polyvinyl ether, polyvinyl ketone, lecithin and the like. These can be used by polymerizing with a hydrophilic substance.

In addition, as a commercially available compatibilizing agent, there is a method in which a macromonomer is used to react with a hydrophilic substance and a polymer is blended as a graft polymer. It is useful to react the macromonomer with a polar hydrosyl or carboxyl group. Further, a reactive compatibilizing agent composed of a hydrophilic urethane, an aliphatic amine and a mono- or diglycidyl ether is also useful.

The foaming agents used in the present invention include volatile foaming agents and decomposable foaming agents. In the former case, carbon dioxide gas, propane gas, methyl ether, fluorine trichloride, methane gas, butane gas, etc. are heated. It is vaporized and foamed. The latter is one that produces gas by heat decomposition and foams, and there are those that utilize inorganic compounds such as ammonium carbonate, sodium bicarbonate, and those that utilize resins or organic substances.

As an example of the organic foaming agent, 2,2'-azobisisobutyronitrile, azohexahydrobenzonitrile, azodicarbonamide, diazoaminobenzene,
Azo-based foaming agents such as azobisformamide and azodiisobutylnitrile, nitroso-based foaming agents such as N, N'-dinitrosopentamethylenetetramine, N, N'-dinitroso-N, N'-dimethylterephthalamide, benzenesulfonylhydrazide , P-toluenesulfonyl hydrazide, diphenylsulfone-3,3′-disulfonylhydrazide, diphenyloxide-4,4′-disulfonylhydrazide and other hydrazide-based foaming agents, and other foaming agents (terephthalazide, p-toluenesulfonyl) Semicarbazide, trihydrazinotriazine, p-tert
Butylbenz azide, etc.)

When the above-mentioned thermoplastic resin is 100 parts by weight, the cement is 50 to 600 parts by weight and the foaming agent is 1 part by weight.
0 to 30 parts by weight, if necessary, 0.1 to 20 parts by weight of a hydrophilic alloying agent, and further 80 to 4 water for hydration.
00 parts by weight are kneaded and molded. During molding, the kneaded mixed material is heated to gelate the thermoplastic resin and hydrate the cement. In addition, what is gelation?
When gradually heated until reaching the melting temperature, it means that the viscosity once dropped rapidly rises, and finally particles come into contact with each other to lose fluidity and apparently solidify. And
The molded body is cooled with water or air.

In the molded body thus obtained, open cells are formed on the surface and inside by the action of the foaming agent. Therefore, it is easy for water to enter the molded body from the outside during curing of the molded body, and the hardening of the cement particles is accelerated. Therefore, in the present invention, it is understood that the hydrophilic alloy agent described above is not essential and may be added as necessary.

Further, the pressure is adjusted at the time of molding, and low pressure molding,
For example, it can be effectively foamed by molding by extrusion, casting, or low-pressure injection.
When the low-pressure molding is performed as described above, the water absorption during curing is improved as compared with the case where the high-pressure molding is performed as in normal injection. In the case of injection molding, usually 500-2000kg
The injection pressure is about f / cm ² , but in the present invention, it is 20
The injection pressure is set to about 0 to 500 kgf / cm ² .

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C04B 28/02 C04B 28/02 // C04B 103: 42 (71) Applicant 000223414 Tsutsunaka Plastic Industry Co., Ltd. Osaka Prefecture Osaka City Chuo-ku 3-5-11 Doshomachi (71) Applicant 000010065 Fukubi Chemical Industry Co., Ltd. 33-66, Sanhashacho, Fukui City, Fukui Prefecture (71) Applicant 000201582 Maezawa Kasei Kogyo Co., Ltd. Tokyo 3-29, Kyobashi, Chuo-ku, Tokyo (71) Applicant 000005913 1-2-1, Otemachi, Chiyoda-ku, Tokyo (72) Inventor, Junsuke Kyomen, 64, Ishizukita-machi, Sakai-shi, Osaka Stocks Company Kubota Vinyl Pipe Factory (72) Inventor Masayuki Sakaguchi 64, Ishizukitacho, Sakai City, Osaka Prefecture Kubota Vinyl Pipe Factory (72) Inventor Wataru Terrestrial Sakai, Osaka Prefecture Ishizukita-cho, 64 address, Ltd. Kubo Tabinirupaipu in the factory (72) inventor Mako Miki Sakai, Osaka Prefecture Ishizukita-cho, 64 address, Ltd. Kubo Tabinirupaipu in the factory

Claims (4)

[Claims] 1. A method for molding a thermoplastic cement, which comprises foam-molding a mixed material of a thermoplastic resin, cement and a foaming agent. 2. The method for molding a thermoplastic cement according to claim 1, wherein the mixture further contains a hydrophilic alloying agent. 3. The method for molding a thermoplastic cement according to claim 1, wherein the mixture is foam-molded at a low pressure. 4. A molded body of thermoplastic cement, which is molded by the method according to any one of claims 1 to 3.