Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1997-04-21
1998-09-08
Housel, James C.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
524130, 524131, 524132, 525100, 525440, 5254445, 525466, 525476, 528 26, 528 27, 528 28, C08F 800
Patent
active
058046747
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a mold release agent, a cured film obtained from said mold release agent, and a molding method using said mold release agent. More particularly, it relates to a mold release agent used for producing a molded article of a polymeric compound such as a synthetic resin and rubber, a cured film, and a molding method.
RELATED ART
In order to obtain a molded article of a resin or rubber, the molding is conducted after charging a resin or rubber material in a mold. Usually, a mold release agent is previously applied to the mold before charging.
As the mold release agent, waxes (e.g. a paraffin wax and a polyethylene wax), silicones (e.g. a polydimethylsiloxane oil and a silicone resin), organic compounds (e.g. glycol, a fatty acid derivative and a perfluoroalkyl group-containing compound) and inorganic compounds (e.g. a mineral oil, talc and mica) are used after dispersing or dissolving the mold release agent in water or an organic solvent.
Although these mold release agents are usually applied every time of the molding, it is required to develop a mold release agent having a prolonged release life to reduce the number of steps in view of the workability. A problem of mold contamination due to accumulation of the mold release agent is caused by applying every time. In case of a wax mold release agent, the degree of contamination is particularly intense. The main reason why the application of the mold release agent is required every time is that the mold release agent moves to the molded article, which gives the poor finishing such as tackiness of the molded article, the poor coating and poor adhesion to the molded article in the post step. Therefore, the washing with the organic solvent such as trichloroethane is conducted. Particularly, the silicone mold release agent causes the poor coating and poor adhesion.
In order to solve these drawbacks, various mold release agents have been developed. Examples thereof include a mixture of a C.sub.4-20 perfluoroalkyl group-containing phosphate ester or a salt thereof and a silicone oil (Japanese Patent Kokoku Publication Nos. 23270/1978 and 23271/1978), a mixture of a C.sub.4-20 perfluoroalkyl group-containing phosphate ester or a salt thereof and a silicone varnish (Japanese Patent Kokoku Publication No. 48035/1982), a mixture of a perfluoroalkyl group-containing polyether compound and a silicone oil (Japanese Patent Kokoku Publication No. 32513/1984) and the like. These are a preferred mold release agent which is superior in a mold release performance, and their mold release life is longer than that of a conventional one. The mold release agent comprising the mixture of the perfluoroalkyl group-containing polyether compound and the silicone oil exerts very small influence on the fabricability of almost all of polymeric compound molded articles. However, these mold release agents can not satisfy the mold release performance and mold release life which are required with complication of the shape and enlargement of the size of the polymeric molded article
Japanese Patent Kokoku Publication No. 39804/1991 discloses a mold release agent containing a perfluoroalkyl group-containing acrylic polymer and a ladder polymer of organosilsesquioxane, as a curing film-forming type mold release agent having a prolonged release life. This mold release agent is superior in the initial release performance and the release life is prolonged to some degree. However, since a strength of the cured film is insufficient, a satisfactory release life is not obtained.
Furthermore, Japanese Patent Kokoku Publication No. 11605/1991 discloses a mold release agent containing polydimethylsiloxane, and an alkoxysilane represented by the formula: methoxyethyl group; Z.sup.2 is a monovalent hydrocarbon group or halogenated hydrocarbon group having 1 to 4 carbon atoms; and v is 3 or 4, or an oligomer product obtained by partial hydrolysis or condensation of the alkoxysilane, and a metal alkoxide such as tetraalkyl titanate. However, this mold releas
REFERENCES:
patent: 4118235 (1978-10-01), Horiuchi et al.
patent: 4308063 (1981-12-01), Horiuchi et al.
patent: 4427803 (1984-01-01), Fukui et al.
patent: 4840675 (1989-06-01), Fukui et al.
patent: 4923945 (1990-05-01), Isozaki et al.
patent: 4972027 (1990-11-01), Isozaki et al.
patent: 5026793 (1991-06-01), Nakai et al.
patent: 5079299 (1992-01-01), Hisamoto et al.
patent: 5492968 (1996-02-01), Nakai et al.
patent: 5639820 (1997-06-01), Kubo et al.
Kashiwagi Masato
Nakamae Yasushi
Sakashita Hirotoshi
Yamana Masayuki
Daikin Industries Ltd.
Housel James C.
Swartz Rodney P.
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