Method of producing wood fiber type composite material product having high rigidity and high heat deformation temperature characteristics

A method for producing a composite material product, which has a high rigidity and a high heat deformation temperature, mainly composing of wood cellulose filler and an olefin series plastic, said method comprising the steps of:

• adding a mixture of calcium oxide and a rigidity improving agent to a mixture of wood cellulose filler crushed into a predetermined size and a granular olefin series plastic material, said rigidity improving agent mainly consisting of polypropylene modified by maleic anhydride or its derivative, an amount of said calcium oxide to be added being calculated so that water of said wood cellulose filler becomes finally 2-5% (percent weight);
• and
• molding a compound produced by mixing those mixtures, by use of a molding machine,
• wherein said polypropylene modified by maleic anhydride has a high degree of modification by maleic anhydride and a small molecular weight.

A method for producing a composite material product, which has a high rigidity and a high heat deformation temperature, mainly composing of wood cellulose filler and an olefin series plastic, said method comprising the steps of:

• adding a rigidity improving agent to a mixture of wood cellulose filler crushed into a predetermined size, a granular olefin series;
• plastic and calcium oxide, said rigidity improving agent mainly consisting of polypropylene modified by maleic anhydride or its derivative, an amount of said calcium oxide to be added being calculated so that water of said wood cellulose filler becomes finally 2-5% (percent weight);
• and
• molding a compound produced by adding said rigidity improving agent to said mixture, by use of a molding machine,
• wherein said polypropylene modified by maleic anhydride has a high degree of modification by maleic anhydride and a small molecular weight.