Abstract: The present invention provides an injection molding method for providing a molded product with excellent transcription and an excellent gloss level. In this method, immediately after a resin is filled in a cavity (1), a carbon dioxide gas is injected or the skin layer is moved back to form a space (13) between the resin and the die surface (1), so that growth of the skin layer is hold down, and at the same time the carbon dioxide is dissolved in the skin layer for lowering the glass transition point of skin layer. Then the skin layer is again closely cohered to a surface of the die by increasing the resin pressure and cooling the molded product for solidifying behind the holding pressure. With this method, products with excellent transcription and with an excellent surface gloss level can be obtained.

Abstract: An agent for imparting flame retardancy to a thermoplastic resin contains a polyhydric phenol such as a tannin compound as an effective component. The thermal stability of the thermoplastic resin can be improved so as to elevate the decomposition temperature of the thermoplastic resin if a small amount of the flame retardancy imparting agent is added to the thermoplastic resin so as to suppress the combustibility of the thermoplastic resin.

Abstract: Provided is an additive for a thermoplastic resin prepared by mixing tannin with a coupling agent, and the above additive inhibits the thermoplastic resin from being reduced in a molecular weight in heating and melting and achieves heat stabilization of the thermoplastic resin. Accordingly, it becomes possible to recycle the molded articles.

Abstract: The present invention provides a resin additive obtained by subjecting inorganic particles to surface treatment with catechin, a resin additive obtained by subjecting inorganic particles to surface treatment with catechin and further subjecting them to surface treatment with a coupling agent or a resin additive obtained by subjecting inorganic particles to surface treatment with catechin and then subjecting them to surface treatment with a phenone compound or saccharides, followed by further subjecting them to surface treatment with a coupling agent. These resin additives have the effect to inhibit a reduction in the molecular weight of a thermoplastic resin in heating and melting or inhibit a reduction not only in the molecular weight but also the IZOT impact strength.

Abstract: Tannin obtained by dehydrating it by heating up to 70 to 230° C. to subject it to polycondensation is used as a resin additive.

Abstract: Improved efficiency of deposition work between a protection trimming and a clip seat of an automobile is provided with an automatic deposition machine having wire heating elements (3a and 3b), a first connection member (1) connected to one end of the wire heating elements (3a and 3b), a movement mechanism for moving the first connection member (1), a second connection member (2) that can be connected to the other end side of the wire heating elements (3a) and (3b) and a bending jig (5) for overlapping the clip seat the member for the protection trimming. The dip seat and the protection trimming are interconnected, to the rear face of the protection trimming via the wire state heating elements (3a and 3b), the retainer member (4) for retaining the said overlapped clip seats, and the power source for carrying the electric current between the said first connection member and the said second connection member. In addition, the wire heating element is designed with a pipe structure.

Abstract: The deposition strength is enhanced in the thermally deposited portion of thermoplastic resin molded product. In addition, in the test for obtaining the deposition strength, the shape and dimensions that can reach the purposed deposition strength is defined. If the annular groove (21) for fixing the heating element (30) is installed to the periphery of the deposited portion of lower case (20) and the annular rib (11) is fitted into the annular groove (21) is installed to the deposited portion of upper case (10) and if the diameter of heating element (30) to be used is considered to be D, then (a) the interval L between both the lateral walls in the annular groove 21 shall be set to 1.3 D L 1.6 D (b) the wall thickness T of annular rib shall be set to 1.1 D T 1.2 D (c) the height A of outside lateral wall in the annular groove shall be set to A 2 D (d) the height B of inside lateral wall in the annular groove shall be set to B 2 D, and (e) the height H of annular rib shall be set to H A.

Abstract: The present invention provides a resin additive obtained by subjecting inorganic particles of silica or alumina to surface treatment with tannic acid and further subjecting them to surface treatment with a coupling agent, or subjecting inorganic particles to surface treatment with tannic acid and then subjecting them to surface treatment with a phenone compound or saccharides, followed by further subjecting them to surface treatment with a coupling agent. The above resin additive has an effect to provide a thermoplastic resin with heat stability in heating and melting the resin and prevent a reduction in the IZOT impact strength.

Abstract: The present invention relates to silicon oxide having tannic acid adsorbed thereon, which is used as a degradation-preventing additive for a thermoplastic resin. This can be obtained by treating 100 parts by weight of silicon oxide with a solution containing 0.5 to 8.0 parts by weight of tannic acid to allow tannic acid to be adsorbed thereon. A reduction (degradation) in a molecular weight of a thermoplastic resin brought about by hydrolysis caused by moisture for a long period of time or thermal decomposition in molding can be inhibited by adding 0.2 to 3.4 % of the tannic acid-adsorbed silicon oxide thus obtained to a thermoplastic resin.

Abstract: A molded product is thermally bonded mutually with another molded product by disposing the resistance heating element (20) to the bonding face of product molded with the thermoplastic resin, making the bonding electrode (10) contact the resistance heating element (20) and by impressing the voltage for its heat generation. The heat generation temperature of the resistance heating element (20) at the voltage impressed portion (21) is suppressed to the level lower than the fusion temperature of resin by blowing the cooling gas toward the voltage impressed portion (21) from a vent hole (11) provided on the bonding electrode (10).

Abstract: A molded product which is molded with thermoplastic resin by a thermal deposition method. The method uses a substantially ring-shaped resistance heating element. A hole is provided for impressing the voltage by inserting the electrode from this hole and impressing the voltage to the resistance heating element. Thereafter the hole is blocked. The electric resistance heating body is disposed between the composition planes of the parts which are to form a body.

Abstract: A polycarbonate resin composition comprising substantially:94.0-99.5% by weight of a polycarbonate resin, and0.5-6.0% by weight of zeolite having tannic acid adsorbed thereon.In this polycarbonate resin composition, the molecular weight reduction of polycarbonate resin is suppressed.

Abstract: A reference pressure of melted material injected to a mold cavity of a mold is set as a function of injection passing time from a start of an injecting process or a function of a distance of movement of an injection plunger, and the movement of the plunger is started at a temporarily constant injection speed. A correction value of the injection speed is obtained to eliminate a difference between a sensed pressure of the melted material injected to the mold cavity of the mold and the reference pressure in a range that the sensed pressure of the melted material exceeds the reference pressure during the injection passing time from the start of the injection process wherein the plunger is started to move or during the movement of the plunger, and the injection speed is corrected in accordance with the corrected value.

Abstract: A method of making plastic molding consists of a boxlike body having an field of multiple fine conical holes. The internal diameter of the fine conical holes gradually decreases from the inner surface of the plastic molding toward the outer surface of the plastic molding, and is in the range 0.1-0.5 mm at the outer surface. The fine conical holes are hardly visible when the outer surface of the box is viewed; ventilation is provided without detriment to the aesthetic appearance of the exterior of the box, and it is not necessary to cover the ventilation holes in the box to keep them out of sight. Conical projection on a male mold are withdrawn before the plastic molding hardens completely and the male mold is separated from a female mold after the plastic material has hardened completely.