Abstract: A method for preparing 1,3-dihydroxy-4,6-bis?.alpha.-methyl-.alpha.-.alpha.(4'-hydroxyphenyl)ethy l!benzene represented by the following formula (1): ##STR1## comprising the step of initiating a reaction of resorcin with 4-isopropenylphenol in a mixed solvent which comprises a non-polar solvent and a polar solvent in the presence of an acidic catalyst. The method can easily be handled, ensures a high yield, permits the reduction of impurity content and can provide highly pure 1,3-dihydroxy-4,6-bis?.alpha.-methyl-.alpha.-(4'-hydroxyphenyl)ethyl!benze ne. The resulting phenolic compound is useful as, for instance, a branching agent for polycarbonates, polyesters or the like; a raw material for radiant ray-sensitive components for use as resist materials; a raw material for epoxy resins; and a hardening agent for epoxy resins.

Abstract: Articles matters which can be degraded and disappear in the natural environment are a degradable adhesive film which can be used for surface protection or indication after printing on the film surface and has an adhesive layer on one side of a substrate film obtained from a lactic acid base polymer such as polylactic acid and a lactic acid/hydroxycarboxylic acid copolymer having a molecular weight of 30,000.about.500,000, and a degradable resin composition which is excellent in weatherability and comprises 100 parts by weight of a lactic acid base polymer and 0.001.about.5 parts by weight of one or more additives selected from ultraviolet absorbers and light stabilizers.

Abstract: An allyletherificated phenol aralkyl resin is obtained through the reaction of a phenol aralkyl resin with an allyl halide in the presence of a base in an organic solvent at room temperature to 100.degree. C. and changed into an allylated phenol aralkyl resin at 160.degree.-250.degree. C. through Claisen rearrangement. The two resins are low in melt viscosity. Epoxy resin compositions containing the allylated phenol aralkyl resin as the curing agent give cured products being excellent in heat and moisture resistances.

Abstract: A phenolic resin composition herein disclosed comprises, as essential components, (i) at least one phenol resin A selected from the group consisting of residues formed through purification of bisphenol A, residues obtained by cleaving the bisphenol A-purification residue, condensates of the bisphenol A-purification residue obtained by reacting the bisphenol A-purification residue with formaldehyde and condensates of the cleavage residue obtained by reacting the cleavage residue with formaldehyde, and (ii) at least one phenolic resin B selected from the group consisting of high-boiling fraction obtained through production of bisphenol F and condensates of the high-boiling fraction obtained by reacting the high-boiling fraction with formaldehyde.

Abstract: A phenolic resin composition comprises a mixture of 100 parts by weight of a phenol aralkyl resin and 5 to 60 parts by weight of a novolak type phenolic resin having a content of binuclear components of not more than 10% by area, and a content of trinuclear components of not less than 50% by area and a sum content of tri- and tetra-nuclear components of 75% by area based on the total novolak phenolic resin except for the binuclear components, and an epoxy-cured product obtained by curing an epoxy resin while using the phenolic resin composition as set forth in claim 1 as a curing agent. The phenolic resin composition has a low viscosity and, when it is used as a curing agent for epoxy resins, the resulting epoxy-cured product has a low water absorption rate, is excellent in resistance to moisture and has a high glass transition temperature as compared with the cured product obtained using a novolak type phenolic resin as a curing agent.

Abstract: Articles which can be degraded and disappear in the natural environment are a degradable adhesive film which can be used for surface protection or indication after printing on the film surface and has an adhesive layer on one side of a substrate film obtained from a lactic acid base polymer such as polylactic acid and a lactic acid/hydroxycarboxylic acid copolymer having a molecular weight of 30,000-500,000, and a degradable resin composition which is excellent in weatherability and comprises 100 parts by weight of a lactic acid base polymer and 0.001-5 parts by weight of one or more additives selected from ultraviolet absorbers and light stabilizers.

Abstract: A degradable non-woven fabric obtained from an web formed of lactic acid-based polymer filaments comprising of one or more lactic acid-based polymers selected from a poly (DL-lactic acid) having more than 80 mol % of L-lactic acid units, poly (DL-lactic acid) having more than 80 mol % of D-lactic acid units, L-lactic acid/hydroxycarboxylic acid copolymer having 70 mol % or more of L-lactic acid units, and D-lactic acid/hydroxycarboxylic acid copolymer having 70 mol % or more of D-lactic acid units, and a preparation process of the degradable non-woven fabric which has good dimensional stability and can be degraded and disappeared under natural environment when abandoned.

Abstract: In the preparation of polyester by conducting ring-opening polymerization of a cyclic ester compound in the presence of a hydroxyl compound as a molecular weight regulator in the reaction system, the molecular weight of polyester can be accurately controlled in the desired range by previously estimating the amount of free carboxylic acid contained in the cyclic ester compound and controlling the amount of the hydroxyl compound on the basis of the estimated amount.

Abstract: Crystals of 6,6'-dihydroxy-3,3,3',3'-tetramethyl -1,1'-spirobiindane (hereinafter referred to as SPI) are obtained by cooling a phenol solution containing 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane when crystallization is started at a temperature higher than a transition temperature between SPI and an adduct of SPI with phenol. The crystals are washed with an organic solvent or contacted with water and further washed with an organic solvent. When crystallization is started at a temperature less than the transition temperature, adduct crystals of SPI with phenol are obtained from the phenol solution. Phenol is removed from the adduct crystals and the adduct crystals are contacted with water to obtain a hydrate and further the hydrate is washed with an organic solvent.

Abstract: Herein disclosed is a method for simultaneously preparing a highly pure bisphenol F and/or a bisphenol F for general use and a novolak phenol resin and/or a high molecular weight novolak phenol resin comprising the steps of:(1) a preparation step comprising reacting phenol with formaldehyde in the presence of an acid catalyst and removing the acid catalyst, water and the unreacted phenol from the resulting reaction product to give a crude bisphenol F;(2) a distillation step comprising distilling a part of the crude bisphenol F to give a highly pure bisphenol F, as a distillate, having a binuclear moiety-content of not less than 95% by weight and a novolak phenol resin, as a still-bottom product, having a binuclear moiety-content of not more than 15% by area;(3) a step for mixing the highly pure bisphenol F with the remaining crude bisphenol F to give a bisphenol F for general use; and(4) a step for polymerizing the novolak phenol resin with formaldehyde in the presence of an acid catalyst to give a high molec

Abstract: A phenolic resin can be obtained by a condensation reaction between a specific trifunctional aromatic compound and a phenolic compound. This resin can be reacted with a curing agent such as a hexamine to give cured articles having excellent heat resistance, electrical properties, wear resistance and chemical resistance, and the phenolic resin is also much more excellent in curing reactivity as compared with conventional techniques.

Abstract: A method for preparing 1,1,2,2-tetrakis(4-hydroxy-3,5-dimethylphenyl)ethane (TKXE) comprising subjecting two molecules of bis(3,5-dimethyl-4-hydroxyphenyl) methane to dehydration-condensation under oxidizing conditions, an epoxy resin prepared by epoxidating TKXE obtained by the method and an epoxy resin composition comprising TKXE obtained by the method as a hardener and an epoxy resin as well as methods for preparing the resin and composition. The method makes it possible to prepare highly pure TKXE in the form of crystals. Moreover, the epoxy resin and the epoxy resin composition can provide hardened products excellent in physical properties such as heat resistance and mechanical strength.

Abstract: A surgical filament which has a surface coated with at least one N-long chain monoacylated basic amino acid having an aliphatic acyl group of from 6 to 22 carbon atoms or with a composition containing at least one of said N-long chain monoacylated basic amino acid, and has improved surface-slipping characteristics such as the ability to be passed through tissue and tie down property.

Abstract: A preparation process of high purity bisphenol A from phenol and acetone with a continuous or batch type reactor by on-line estimating with a computer the composition of the reaction mixture and saturated dissolving temperature of bisphenol A under the reaction conditions and by automatically controlling the reaction conditions and liquid transfer conditions of the reaction mixture to the next step. The process does not form crystals of bisphenol A-phenol adduct in the reactor and cooler. A maximum rate of reaction can be obtained. Consequently, fluctuation of reaction temperature can be prevented and the amount of impurities formed is small. The discharge operation of the reaction mixture from the reactor can be carried out steadily and with ease, and does not disturb the operation of successive steps.

Abstract: A biocompatible polyester which has improved hydrolyzability obtained by bonding saccharide to the structure of a polymer consisting of a glycolic acid unit and/or a lactic acid unit, and a process for Preparing the biocompatible polyester are disclosed.

Abstract: A phenolic resin can be obtained by a condensation reaction between a specific trifunctional aromatic compound and a phenolic compound. This resin can be reacted with a curing agent such as a hexamine to give cured articles having excellent heat resistance, electrical properties, wear resistance and chemical resistance, and the phenolic resin is also much more excellent in curing reactivity as compared with conventional techniques.

Abstract: In preparing bioabsorbable polyesters containing glycolic acid unit and/or lactic acid unit by the polymerization of glycolide and/or lactide, compositions comprising polyester-silicone copolymers obtained by conducting polymerization in the presence of silicones and the effect of merely mixing the above bioabsorbable polyesters with certain kind of silicones upon the modification, thereby attaining flexibility in particular, of the bioabsorbable polyesters, are disclosed.

Abstract: Herein provided are a method for preparing 1,1,2,2-tetrakis(4-hydroxy-3,5-dimethylphenyl)ethane (TKXE) comprising subjecting two molecules of bis(3,5-dimethyl-4-hydroxyphenyl) methane to dehydration-condensation under oxidizing conditions, an epoxy resin prepared by epoxidating TKXE obtained by the method and an epoxy resin composition comprising TKXE obtained by the method as a hardener and an epoxy resin as well as methods for preparing the resin and composition. The method makes it possible to prepare highly pure TKXE in the form of crystals. Moreover, the epoxy resin and the epoxy resin composition can provide hardened products excellent in physical properties such as heat resistance and mechanical strength.

Abstract: A preparation process of a phenol-based resin composition by conducting a crosslinking reaction of a specific silicone compound in the phenol-based resin in the presence of a specific emulsifier, crosslinking agent and catalyst and by the addition of water to disperse resulting silicone rubber as fine particles in the phenol-based resin.The phenol-based resin of the invention has no time-dependent variation in molding processability and molded products are stable and has no time-dependent change in impact resistance, flexural strength and thermal shock resistance (heat crack resistance), and hence the phenol-based resin composition is used for various molding materials and friction materials which require excellent mechanical strength, crack resistance, thermal shock resistance, stress relaxation resistance or abrasion resistance.

Abstract: A method for preparing 2,2-bis(4-hydroxyphenyl)propane comprises reacting acetone and phenol in the presence of an acidic ion-exchange resin as a catalyst wherein the reaction of acetone and phenol is performed while removing a part of the water generated during the reaction from a mixed solution containing acetone and phenol by a pervaporation method. According to the method, the water generated through the reaction can rapidly be removed simultaneously with or alternatively to the reaction by a pervaporation operation and, therefore, the catalytic activity of the ion-exchange resin is not impaired at all. Moreover, any complicated operations associated with the dehydration are not required. Thus, the acidic ion-exchange resin catalyst can continuously be used over a long time period without any treatment for the regeneration thereof. Further, according to the method, bisphenol A can be economically prepared from acetone and phenol in a high conversion rate and high yield.