Bridgestone Corporation

Bridgestone Tire Company Limited

Seiji Ishii

Hiroya Fukuda

Takashi Ohashi

Osamu Kondo

Toshio Yukuta

Tokuo Okada

Toshio Iwasawa

Takumi Ishiwaka

Hiroshi Ohta

Kazuo Utsumi

Masanori Miyoshi

A polyurethane seat pad having a center seat portion and bank portions therearound is molded by using a mold defining a cavity having a center region corresponding to the center seat portion and side regions corresponding to the bank portions, placing collecting vessels of expanded polyolefin in the side regions of the mold cavity, pouring a foamable polyurethane liquid for low hardness foam into the cavity between said collecting vessels, pouring a foamable polyurethane liquid for high hardness foam into said collecting vessels, and causing the foamable liquids to expand, thereby producing a polyurethane seat pad having the collecting vessels embedded therein. The expanded polyolefin is a crosslinked polyolefin foam having an index of surface wetting of at least 36 dyne/cm. The seat pad in which the bank portions have higher hardness than the seating portion and which is fully durable against repetitive loading can be produced to the desired configuration in a stable manner.

Method for molding polyurethane seat pads

A method for producing a polyolefin foam sheet which includes heating a foamable base sheet comprising a polyolefin resin, a foaming agent, and a resin varnish. The resin of the varnish is selected from the group consisting of rosin, cumarone-indene resin, phenolic resin, alkyd resin, and shellac resin.

Method for producing polyolefin foam sheet

A method producing a low-density flexible polyurethane foam comprising stirring a starting mixture containing a polyhydroxy compound, a polyisocyanate, a foaming agent and a catalyst to thereby foam the mixture, in which a foaming agent selected from the group consisting of water, formic acid and its salts is used in an amount of at least 10% by weight as water equivalent per 100 parts by weight of the polyhydroxy compound, and the mixture is stirred at 15.degree. C. or below by previously adjusting the temperature of the mixture to 15.degree. C. or below and under a highly catalytic activity.

Method for producing a low-density flexible polyurethane foam

A method of making a foam product including the steps of reacting an isocyanate component with a polyol component and foaming with a foaming agent to form a self-supporting intermediate foam material. The isocyanate component is present in excess of a stoichiometric quantity needed to react with the polyol component. The self-supporting intermediate foam material is then contacted with water and the self-supporting, intermediate foam material is heated to form a foam product, the water reacting with the remaining unreacted isocyanate component. The self-supporting, intermediate foam material formed by the first foaming step is rigid or semi-rigid at room temperature but it can be softened by heating to enable it to be used for deep draw molding in a successive cure molding process without cracking, splitting or being destroyed. Once the self-supporting, intermediate foam material is contacted with water or steam in the final cure molding process to react the remaining isocyanate component, the material becomes a finally cured, rigid or semi-rigid foam material which will not soften on heating. The self-supporting, intermediate foam material can be laminated with facing materials or reinforced with glass fiber--non-woven cloth or the like to give a composite panel which exhibits stiffness, heat insulation, acoustic insulation, moisture resistance and is light in weight so that it can be used for a molded ceiling or door panel in an automobile or a partition or screen for interior use.

Method of making a composite panel of a foam material

Polyol component essentially consists of polyesterpolyetherpolyol containing polyesterpolyol by the weight ratio of 100:0 to 20:80, in which the polyesterpolyetherpolyol is a copolymer of polytetramethyleneglycol (PTMG) and .epsilon.-caprolactone by the weight ratio of 20:80 to 80:20 with an average molecular weight of 1000 to 3000 and the polyesterpolyol is a condensate of adipic acid as a main acid component with an average molecular weight of 1000 to 3000, is reacted with isocyanate component essentially consists of 4,4'-diphenylmethanediisocyanate (MDI) to make a prepolymer with terminal radical of NCO. Microcellular polyurethane produced from the prepolymer by foaming and polymerization reaction has the durability for vibration-proof material of car use, combining the advantage of PTMG such as high initial modulus at elongation, low heat built up, low-temperature property and hydrolysis-durability under high humid and hot conditions, with the advantage of polycaprolactone such as good molding property and anti-bending-fatigue property, as well as making up for the disadvantage of both polyols each other. Thus improving the problems of microcellular polyurethane using MDI such as low initial modulus at elongation and high heat built up.

Microcellular polyurethane elastomer and manufacturing method of the same

A moisture- and heat-resistant flexible polyurethane foam, which is free from lowering of the foam hardness due to moisture absorption during or after the production of the foam under a high temperature and high humidity condition and free from development of scorch during the production of the foam, can be obtained by adding an amino acid or an amino acid analogous compound to a raw material mixture, and foaming the resulting mixture.

Method of producing a moisture- and heat-resistant flexible polyurethane

Flexible urethane foams having a low density and capable of preventing spontaneous combustion during production and storage are produced by compounding 5.0-12.0 parts by weight based on 100 parts by weight of polyhydroxylcompounds, of water and not less than 0.1 part by weight of aromatic amine antioxidant, further preferably not less than 0.01 part by weight of phosphorous acid triesters in the usual combination of polyhydroxyl compounds, polyisocyanates, water, catalysts, surfactants, foaming agent and other additives.

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Yokohama, Japan

Seiji Ishii