An adhesive includes an organic material, an inorganic material, a curing agent and a catalyst. The adhesive is able to bond the wood material, especially recycled wood material. The wood material is not necessary to have any pretreatment like removing color, pigment or plastic lining so as to be introduced to the film process directly. After breaking and adjusting the moisture content of the wood material, it can be mixed with the adhesive and hard pressed into wood product with good duration and quality. The adhesive and the production method of wood board is able to ameliorate the problem of the conventional water based adhesive to save energy and processing time.

An adhesive includes an organic material, an inorganic material, a curing agent and a catalyst. The adhesive is able to bond the wood material, especially recycled wood material. The wood material is not necessary to have any pretreatment like removing color, pigment or plastic lining so as to be introduced to the film process directly. After breaking and adjusting the moisture content of the wood material, it can be mixed with the adhesive and hard pressed into wood product with good duration and quality. The adhesive and the production method of wood board is able to ameliorate the problem of the conventional water based adhesive to save energy and processing time.

Provided are a moisture resistance improver that yields a water-based adhesive for inorganic materials having exceptional adhesiveness of inorganic materials, and a water-based adhesive for inorganic materials in which the moisture resistance improver is used. The present invention is a moisture resistance improver (J) for a water-based adhesive for inorganic materials containing at least one (co)polymer (A) selected from the group consisting of (co)polymer (A1) and (co)polymer (A2). (Co)polymer (A1): a (co)polymer having a weight-average molecular weight of 3,000-150,000, and containing, as structural monomers, a C3-30 unsaturated (poly)carboxylic acid (anhydride) (a1) and a (meth)acrylic acid ester (a2) having solubility of 10 g or less per 100 g of water at 25? C. (Co)polymer (A2): a (co)polymer having a weight-average molecular weight of 6,000-150,000, and containing the above unsaturated (poly)carboxylic acid (anhydride) (a1) as a structural monomer but not containing the above (meth)acrylic acid ester (a2) as a structural monomer.

Provided are a moisture resistance improver that yields a water-based adhesive for inorganic materials having exceptional adhesiveness of inorganic materials, and a water-based adhesive for inorganic materials in which the moisture resistance improver is used. The present invention is a moisture resistance improver (J) for a water-based adhesive for inorganic materials containing at least one (co)polymer (A) selected from the group consisting of (co)polymer (A1) and (co)polymer (A2). (Co)polymer (A1): a (co)polymer having a weight-average molecular weight of 3,000-150,000, and containing, as structural monomers, a C3-30 unsaturated (poly)carboxylic acid (anhydride) (a1) and a (meth)acrylic acid ester (a2) having solubility of 10 g or less per 100 g of water at 25? C. (Co)polymer (A2): a (co)polymer having a weight-average molecular weight of 6,000-150,000, and containing the above unsaturated (poly)carboxylic acid (anhydride) (a1) as a structural monomer but not containing the above (meth)acrylic acid ester (a2) as a structural monomer.