Ube Machinery Corporation, Ltd.

Dai Nippon Toryo Co., Ltd.

Prime Polymer Co., Ltd.

Toshio Arai

Etsuo Okahara

Kazuaki Kobayashi

Kenji Yonemochi

Kenji Oota

Takashi Okusako

Yoshiaki Yamamoto

Takeshi Minoda

Kaoru Yorita

Yuichi Matsuda

Etuo Okahara

An in-mold coating method for molding a molded product with an excellent external appearance. A resin molded product is kept pressed against a mold cavity surface until immediately before coating. Mold-clamping force in a second step in which the shape of the resin molded product is fixed and that in a fourth step are selected so that the deformation of the mold cavity by the mold-clamping forces is substantially the same in the second and fourth steps. Even if the mold cavity deforms by the mold-clamping force in the second step, the mold cavity deforms similarly in the fourth step to provide a uniform coating thickness. Alternatively, a mold-clamping force smaller than that in the first step is selected for the second step to reduce the degree of deformation of the mold cavity and to achieve a uniform coating thickness.

In-mold coat-forming method

An in-mold coating method providing a mold having a specifically formed auxiliary cavity and an in-mold coating formation method which employs said mold, so that it is possible to prevent a coating material from leaking out of the mold, thereby shortening the molding formation cycle, and making it possible to manufacture a molded product having a stabilized quality. In addition, by using a mold having a specifically shaped sub-cavity, there is provided a still further in-mold coating formation method which can keep mold temperature at a relatively low value, cause the coating material to cure at a predetermined temperature and within a predetermined time period thereby shortening the molding formation cycle, improving the productivity, improving the physical properties of a coating layer, thus obtaining a good molded product.

Method of forming a coating layer on the surface of a molded product within a mold

An in-mold coating apparatus providing a mold having a specifically formed auxiliary cavity and an in-mold coating formation method which employs said mold, so that it is possible to prevent a coating material from leaking out of the mold, thereby shortening the molding formation cycle, and making it possible to manufacture a molded product having a stabilized quality. In addition, by using a mold having a specifically shaped sub-cavity, there is provided a still further in-mold coating formation method which can keep mold temperature at a relatively low value, cause the coating material to cure at a predetermined temperature and within a predetermined time period thereby shortening the molding formation cycle, improving the productivity, improving the physical properties of a coating layer, thus obtaining a good molded product.

A process producing an in-mold coated molded product. The process molds a thermoplastic resin material under a mold-clamping pressure in a mold including a fixed mold part and a movable mold part each heated at a predetermined temperature, separates the fixed mold part and the movable mold part when the molded material surface is solidified such that it is durable to a pressure of injection and flow of a coating agent, and injects the coating agent containing a thermosetting resin material between an inner surface of the mold and the molded product obtained. The process also coats the molded product surface with the coating agent as the mold is re-clamped after injecting the coating agent, takes out the molded product coated with the coating agent when the coating agent is cured such that it is neither peeled off nor cracked by opening the mold, and re-heats the molded product after taking it out.

Method of manufacturing formed product coated in mold

An in-mold coating molded article is obtained by coating the surface of a resin molded product comprising a hydroxyl group-containing polypropylene resin composition (A) with a paint composition for in-mold coating, wherein the composition (A) comprises a polypropylene resin (i), an additive rubber (ii) and optionally a polymer compound (iii) other than the polypropylene resin (i) and the additive rubber (ii), the total hydroxyl value of the polypropylene resin (i), the additive rubber (ii) and the optional polymer compound (iii) is from 1 to 40, the composition (A) has a rubber component content (total of the amount of the additive rubber (ii) and the amount of components soluble in n-decane at 23&#xb0; C. of the polypropylene resin (i) and the optional polymer compound (iii)) of from 15 to 80% by mass based on 100% by mass of the total amount of the rubber component and the resin component other than the rubber component, the paint composition comprises a vehicle component comprising 10 to 70% by mass of an oligomer having at least two (meth)acrylate groups and 90 to 30% by mass of an ethylenically unsaturated monomer copolymerizable with the oligomer, a (meth)acryl modified chlorinated polyolefin having a chlorine content of from 2 to 40% by mass, an organic peroxide polymerization initiator, and a polyisocyanate compound.

Molded object obtained by in-mold coating and process for producing the same

An in-mold coat-forming mold and an in-mold coat-forming method are provided, wherein the mold prevents leakage of a coating material for the long term, which is likely to occur when the in-mold coat-forming method is carried out. By disposing a grove, a pressure piece, or both of them so as to serve as coating-material leakage-preventing means, in the vicinity of the edge of a mold cavity adjacent to a shear-structured engaging portion disposed along the circumference of the mold cavity, a coating material is prevented from leaking out of the mold from the engaging portion, and problems such as an adverse affect on a formed product caused by the leaked coating-material and a damage on the mold are prevented, whereby in-mold coat-forming is stably performed for the long term.

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Ube, Japan

Toshio Arai