Abstract: A non-hydrous soft contact lens comprising a copolymer comprising, as monomer units:(a) from 33.9 to 89 mol % of an acrylate represented by the general formula (I) shown below;(b) from 4.9 to 65 mol % of a methacrylate represented by the general formula (II) shown below;(c) from 1 to 20 mol % of at least one selected from an unsaturated carboxylic acid and its particular esters;(d) from 0 to 20 mol % of a particular acrylic acid ester having a straight chain alkyl or fluoroalkyl group;(e) from 0 to 20 mol % of a methacrylic acid ester having a straight-chain alkyl group;(f) from 0.1 to 10 mol % of a crosslinking monomer.General formula (I): ##STR1## wherein R.sub.1 is a particular straight-chain alkyl or fluoroalkyl group. General formula (II): ##STR2## wherein R.sub.2 is a particular straight-chain fluoroalkyl group; and a process for preparing the same. This contact lens has good oxygen permeability, mechanical strength, etc.

Abstract: A non-hydrous soft contact lens comprising a copolymer comprising, as monomer units, 49.9 to 95 mole % of an acrylate represented by Formula (I) shown below, 0 to 10 mole % of acrylic acid or the specified ester thereof, 4.9 to 50 mole % of a methacrylate represented by Formula (II) shown below, and 0.1 to 10 mole % of a crosslinking monomer. ##STR1## wherein R.sup.1 is at least one selected from the group consisting of a particular straight chain fluoroalkyl group and a particular straight chain alkyl group. ##STR2## wherein R.sup.2 is a particular straight chain fluoroalkyl group. The present soft contact lens requires no sterilization by boiling, and has good resistance to stain, good oxygen permeability, good elastic recovery and good shape stability.A process for producing the above non-hydrous soft contact lens, comprising the step of subjecting a rigid precursor lens to treatment(s) of esterification and/or transesterification, is also disclosed.

Abstract: A process for producing shaped articles having improved surfaces, characterized by subjecting a shaped article of a polymer derived from a monomeric material comprising an acrylate and/or methacrylate to at least one of a hot water treatment, an aqueous alkali solution treatment and an aqueous acid solution treatment. Shaped articles obtained by this process have an advantage that when the surfaces thereof are stained the removal of the stains is quite easy. Moreover, they are hydrophilic and have excellent wettability by water. Therefore, said shaped articles are extremely suitable for use as contact lens.

Abstract: A uniformly colored shaped article which is resistant to discoloration and fading can be produced by immersing a shaped article, particularly a contact lens, consisting of a polymer of at least one monomer selected from the group consisting of acrylates and methacrylates in a dyeing solution prepared by dissolving a water-soluble dye in a solvent capable of swelling said polymer, to swell and color the shaped article, and then drying the swollen shaped article.

Abstract: A laddery lower alkylpolysilsesquioxane represented by the formula: ##STR1## wherein R and R' represent same or different lower alkyl groups, and n represents an average degree of polymerization, said laddery lower alkylpolysilsesquioxane having a heat-resistant thin film-formability, characterized in that 15 to 30% by weight of the lower alkylpolysilsesquioxane is occupied by the portion having a standard polystyrene-reduced molecular weight of 20,000 or less as measured by gel permeation chromatography. Said silicone resin in which R and R' are methyl is prepared by dissolving CH.sub.3 SiCl.sub.3 in a ketone or an ether, adding water to this solution with stirring to hydrolyze CH.sub.3 SiCl.sub.3, condensing the hydrolyzate and, if necessary, subjecting the resulting condensate to a treatment for adjusting the proportion of the low molecular weight portion in the product.

Abstract: A dental hydraulic investment comprising (A) an aqueous polyvinyl alcohol solution, (B) a water-soluble metallic compound, (C) a water-soluble, thermosetting resin precondensate and (D) a filler. Use of this investment allows formation of a desired denture by either a thermal polymerization or a room temperature polymerization method, and the denture thus obtained has excellent surface luster and is high in dimensional accuracy.