摘要:
Disclosed is a process for the production of an injection-expansion molded, thermoplastic resin product. The process comprises a gas dissolving step, a cooling step, a metering and injection step, and an expansion controlling step. Specifically, a thermoplastic resin is molten in a continuous plasticator (1), supercritical carbon dioxide and/or nitrogen is added as a blowing agent, and the blowing agent and the thermoplastic resin are formed into a mutually-dissolved state. The resultant molten resin composition is cooled within the plasticator while maintaining a pressure equal to or higher than a critical pressure of the blowing agent. The thus-cooled molten resin composition is metered by an injector (7) and is filled in a mold (8). An internal pressure of the mold is lowered beyond the critical pressure of the blowing agent to produce cell nuclei, whereby the cell diameter is controlled. The blowing agent is maintained in a supercritical state up to the metering and injection step.
摘要:
A process for preparing an expanded product of a thermoplastic resin which includes a gas dissolving step of adding supercritical carbon dioxide and/or nitrogen as an blowing agent to a thermoplastic resin, and melting it in the thermoplastic resin, a cooling step of cooling the resulting molten resin composition under a pressure not less than a critical pressure of the blowing agent, a nuclei forming step of discharging the molten resin composition from a die to lower the pressure to a level not more than the critical pressure, and an expansion controlling step of cooling an expanded product of the thermoplastic resin to a level not more than a glass transition temperature or a crystallization temperature of the resin to control a cell diameter of the expanded product.
摘要:
A process is provided for the production of expanded olefinic thermoplastic elastomer product having good external appearance, flexibility and heat resistance. This process features using, as raw materials, a particular olefinic thermoplastic elastomer and carbon dioxide as a blowing agent.
摘要:
This invention provides a method for stably adding a predetermined amount of supercritical carbon dioxide at a fixed delivery rate into a forming machine and also a process for producing an expanded thermoplastic resin product by making use of the addition method. Carbon dioxide is charged from a liquefied carbon dioxide cylinder (1) into a predetermined amount deliverable pump (2) while allowing the carbon dioxide to remain in a liquefied state. When the carbon dioxide is pressurized and delivered by the predetermined amount deliverable pump (2), a delivery pressure of the carbon dioxide is controlled at an optional pressure within a range of from a critical pressure (7.4 MPa) of carbon dioxide to 40 MPa to deliver the carbon dioxide without any fluctuation of the amount of the delivery by setting up the pressure of a pressure control valve (3). The carbon dioxide is heated to a critical temperature (31° C.) of carbon dioxide or higher to convert it into supercritical carbon dioxide. This supercritical carbon dioxide is then added to a molten thermoplastic resin in the forming machine (4).
摘要:
The method of the present invention for producing a urethane-based thermoplastic elastomer composition foam comprises the steps of: adding and mixing 0.1 to 30 parts by weight of carbon dioxide (B) to 100 parts by weight of a urethane-based thermoplastic elastomer composition (A) in a molten state, wherein said urethane-based thermoplastic elastomer composition (A) comprises a urethane-based thermoplastic elastomer (A-1) and other thermoplastic elastomer (A-2) in an (A-1)/(A-2) ratio of 20/80 to 99/1 by weight, to form a molten urethane-based thermoplastic elastomer composition (C) which is in a state of a mixture of the urethane-based thermoplastic elastomer composition (A) and the carbon dioxide (B) (gas dissolving step); and lowering a temperature of said molten urethane-based thermoplastic elastomer composition (C) (cooling step). The present invention can produce the urethane-based thermoplastic elastomer foam of stable quality over a range from low foamed product to highly foamed product by adding a given quantity of carbon dioxide in the molten urethane-based thermoplastic elastomer quantitatively and stably. It can also produce the foam excellent in flexibility, thermal insulation and surface appearances. It is also excellent in safety, because of use of carbon dioxide in place of the common foaming agent of fluorochlorohydrocarbon or butane, thus causing no air pollution or destruction of the ozone layer.
摘要:
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° 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 in a specific proportion. In the process for preparing the article, the article is prepared by injection molding method, injection compression molding method or injection press molding method. Accordingly, there can be provided an in-mold coating molded article such that the paint composition is monolithically formed on the surface of the resin molded product of the composition with good adhesion and a process for preparing the same.
摘要:
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° 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.