Abstract: An infrared absorber which comprises containing as an effective ingredient a hydroxide complex salt represented by the formula [Al2(Li(1−x).+M2+(x+y)(OH)(6+2y)]n(An−)(1+x).mH2O (wherein M2+ is a divalent metal, An− is an anion having a valence of n, and m, x and y are numbers respectively in the ranges of 0≦m<5, 0.01≦x≦0.5 and 0≦y≦0.5), which has a high ability to absorp infrared rays and a refractive index close to that of the resin so that it has a good dispersibility with the resins when incorporated in the resin and the shaped film therefrom is excellent in the heat insulation property and transparency so that it is suitable as an agricultural film.

Abstract: A novel hydroxide complex with condensed silicate represented by the formula (I)?Al.sub.2 (Li.sub.(1-x).M.sup.2+.sub.x)(OH).sub.6 !.sub.2 (Si.sub.y O.sub.2y+1.sup.2-).sub.1+x.mH.sub.2 O (I)wherein M.sup.2+ is a divalent metal, m, x and y are numbers respectively in the ranges of 0.ltoreq.m<5, 0.ltoreq.x<1 and 2.ltoreq.y.ltoreq.4, a process for preparing the same, an infrared absorber containing the same as an effective ingredient, and an agricultural film containing said infrared absorber.

Abstract: The object of the present invention is to prepare a calcium hydrogen phosphate that has excellent binding properties, a large oil adsorption capacity and a specific surface area, and is therefore suitable as an excipient.A scale-like calcium hydrogen phosphate is prepared by reacting phosphoric acid with an alkaline calcium compound such as quick lime, in the presence of a multivalent organic acid with coordinating ability, such as citric acid, to obtain a columnar calcium hydrogen phosphate, and then hydrothermally treating the obtained columnar calcium hydrogen phosphate at a temperature of 60.degree. C. or higher.