摘要:
In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde, the pH of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being strongly adhered to the wall surface, thereby providing an excellent effect of preventing adhesion of the product polymer to the wall surface.
摘要:
In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde, the pH of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being strongly adhered to the wall surface, thereby providing an excellent effect of preventing adhesion of the product polymer to the wall surface.
摘要:
A method for polymerizing vinyl chloride comprises polymerizing vinyl chloride in an aqueous medium or bulk-polymerizing vinyl chloride, wherein the inner wall of a polymerizer and parts of devices which come in contact with the monomer during the polymerization are coated, prior to the polymerization, with a reaction product having a molecular weight ranging from 500 to 100,000, obtained by condensing a polyhydric phenol and sulfur dichloride in the presence of a Lewis acid as a catalyst. The amount of the polymer adhered to the polymerizer during polymerization of vinyl chloride is substantially lowered and the adhered polymer can be easily washed away through simple water washing according to the foregoing method. Moreover, the method does not adversely affect the reaction time and the quality of the resulting product at all.
摘要:
A polyimide resin composition substantially comprising 1 99.9.about.50 parts by weight of polyimide having recurring structural units of the formula ##STR1## and 2 0.1.about.50 parts by weight of a polyimide which improved melt flowability and is prepared by using 1,3-bis(3-aminophenoxy)benzene or 6,6'-bis(3-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobiindane as essential diamine component, or polyether pyridine having recurring structural units of the formula: ##STR2## is disclosed. Further, a polyimide based resin composition comprising the polyimide resin composition or a polyimide copolymer obtained by using the above diamines and a fibrous reinforcement is disclosed. These compositions have remarkably good processability, excellent heat stability and repeated fatigue characteristics.
摘要:
Disclosed is an aromatic diamine compound represented by the formula (I) ##STR1## wherein R is H or CH.sub.3. Also disclosed is a bismaleimide compound represented by the formula (IV) ##STR2## wherein R is H or CH.sub.3, A resin forming composition comprising these compounds is also disclosed. The compounds are useful as raw materials for resins, and the resin forming composition and the resin can provide excellent heat resistance and impact resistance and low hygroscopicity.
摘要:
A heat-resistant and thermoplastic polyimide which has low dielectric characteristics and recurring structural units of the following formula: ##STR1## wherein R is a tetravalent radical having from 2 to 27 carbon atoms and selected from the group consisting of an aliphatic radical, alicyclic radical, monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or a bridge member; aromatic diamines which are useful for the raw material monomers of the polyimide and have following formulas: ##STR2## and a process for preparing the polyimide of the above formula by reacting these aromatic diamines with a tetracarboxylic dianhydride in the presence of an aromatic dicarboxylic anhydride or aromatic monoamine, and successively thermally or chemically imidizing the resultant polyamic acid; are disclosed.
摘要:
Disclosed is an aromatic diamine compound represented by the formula (I) ##STR1## wherein R is H or CH.sub.3. Also disclosed is a bismaleimide compound represented by the formula (IV) ##STR2## wherein R is H or CH.sub.3, A resin forming composition comprising these compounds is also disclosed. The compounds are useful as raw materials for resins, and the resin forming composition and the resin can provide excellent heat resistance and impact resistance and low hygroscopicity.
摘要:
An opoxy resin is obtained by reacting an epihalohydrin with an imido-ring-containing diphenol represented by the following formula (I): ##STR1## wherein R represents an aliphatic group having at least two carbon atoms, an alicyclic group, a monocyclic aryl group, a fused polycyclic aromatic group, or a non-fused polycyclic aromatic group formed of aromatic groups coupled together directly or via a linking member and the two hydroxyl groups are each bonded to a meta position or the para position. In the epoxy resin, at least 50% of the hdroxyl groups of molecules of the diphenol have been opoxidized.
摘要:
2,2'-Bisphenol sulfoxides are prepared by oxidizing 2,2'-bisphenol sulfides with hydrogen peroxide in the presence of such an organic solvent as not to form any organic peracids under reaction conditions.
摘要:
This invention relates to a novel thermoplastic and amorphous polyimide which is readily soluble in organic solvent, a novel aromatic diamino compound used for the polyimide, a preparation process thereof, a polyimide-based resin composition comprising the thermoplastic polyimide and a fibrous reinforcement, a process for preparing the resin composition, an injection molded article of the resin composition, a polyimide-based composite obtained by molding the above soluble and thermoplastic polyimide in combination with a fibrous reinforcement, and a fibrous reinforcement having a surface modified with the above polyimide. The polyimide comprise a requisite structural unit having one or more recurring structural units of the formula: ##STR1## wherein m and n are individually an integer of 0 or 1, and R is ##STR2## The polyimide of the invention is essentially amorphous, excellent in melt flow stability in the decreased temperature as compared with conventionally known polyimide and has greatly improved processability. The polyimide of the invention obtained by using a novel aromatic diamino compound as a monomer can control various properties such as melt flow ability and solubility in solvents by side chains and not by principal chain of polyimide. Thus, excellent melt flow property and solubility in solvents can be obtained while maintaining high heat resistance and adhesive property which are derived from benzophenone structure of the diamino compound of the the invention.