Embodiment:

Make formaldehyde polyvinyl acetal by existing formaldehyde polyvinyl acetal manufacturing process earlier: get the reactor that 50 kilograms of polyvinyl alcohol are put into the carrying vapour chuck, add 450 kg of water, heating is under agitation dissolved polyvinyl alcohol fully then.With hydrochloric acid solution is regulated pH and be approximately 2, solution is heated to 85～90 ℃ again, add 15 kilograms in formaldehyde then, reacted about 20 minutes, be cooled to 50 ℃, adding liquid caustic soda, to be neutralized to the pH value be 7.Meanwhile, in another reactor, add 100 kilograms of polyvinyl acetate emulsions, add OP-10 500 grams again, 15 kilograms of 5 kilograms of plasticizer phthalic acid dibutylesters and 300 order light calcium carbonates, after fully stirring, resulting mixture is joined in the formaldehyde polyvinyl acetal that has prepared, add again, fully stir discharging after 3 hours with suitable quantity of water dissolved 500 gram urea.

When preparation modified polyvinyl formal white glues, the content of polyvinyl alcohol can be controlled between 8～13%, the content of formaldehyde should be controlled below 4.5%, in order to avoid generation insoluble polymer, poly-acetic acid second dilute emulsion content can be 10～30%, emulsifying agent can be used the product of OP series or TX series, used formaldehyde condensation agent has urea, trimeric cyanamide, Resorcinol etc., it is fixed as the case may be that it adds number needs, said filler is 200～400 purpose lime carbonate, titanium dioxide, talcum powder or a kind of mixture of forming by monomethylolurea and dimethylolurea, the content of filler is about 3～10%, and amount of filler too much occurs precipitation easily and influences the product cohesive strength.