This process is a process for production of a vinyl chloride polymer by suspension polymerization or emulsion polymerization of vinyl chloride monomer or a mixture of vinyl chloride monomer with a vinyl monomer copolymerizable with said vinyl chloride monomer in an aqueous medium, characterized in that the polymerization is carried out in a polymerizer, the inner wall surface and portions of the auxiliary equipment thereof which may come into contact with the monomer during polymerization being previously coated with a scaling preventive comprising at least one selected from dyes, pigments and aromatic or heterocyclic compounds having at least 5 conjugated π bonds, while controlling the chloride ion concentration in the reaction mixture to not higher than 100 ppm. According to said process, scaling onto the inner wall surface of a polymerizer, etc. during polymerization can be prevented effectively and surely.
Polymerization process characterized by a two layer coating against scale formation deposited using a steam carrier
申请人:SHIN-ETSU CHEMICAL CO., LTD.
公开号:EP0934955A1
公开(公告)日:1999-08-11
An improved process for producing a polymer by polymerizing a monomer having an ethylenic double bond in a polymerization vessel having a polymer scale preventive coating film on its inner wall surfaces, etc. is provided. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugated π bonds and a heterocyclic compound having 5 or more conjugated π bonds, and then coating a second coating liquid on the first layer. The first and second coating liquids are applied by means of steam as a carrier. The second layer has a surface having a contact angle to water of less than 60° after its surface has been brought into contact with a solution of mixture of water and a vinyl chloride monomer in a weight ratio of 1:1, at 50°C for 1 hour. This process can shorten the time for forming the coating film to improve productivity, can improve the effect of preventing adhesion of polymer scale, can make colored particles less mix into polymer products obtained by this process, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.
Process for producing a polymer by polymerization of a monomer having an ethylenic double bond
申请人:SHIN-ETSU CHEMICAL CO., LTD.
公开号:EP1063242A1
公开(公告)日:2000-12-27
A process for producing a polymer by polymerizing in a polymerization vessel a monomer having an ethylenic double bond is provided. In this process, the polymerization vessel has a polymer scale preventive coating film on its inner wall surfaces and other surfaces with which the monomer comes into contact during polymerization. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugated π bonds and a heterocyclic compound having 5 or more conjugated π bonds and a second coating liquid containing at least one hydrophilic compound selected from the group consisting of a water-soluble polymeric compound, an inorganic colloid, an inorganic salt and an acid; the first coating liquid and the second coating liquid being simultaneously coated by means of steam as a carrier. This process can shorten the time for forming coating films of scale preventive agents to improve productivity, can improve the effect of preventing scales, can make colored particles less mix into polymer products obtained by this process, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.
Polymerisation process in a reactor with double coating against scale formation
申请人:SHIN-ETSU CHEMICAL CO., LTD.
公开号:EP1043338A1
公开(公告)日:2000-10-11
An improved process for producing a polymer by polymerizing a monomer having an ethylenic double bond in a polymerization vessel having a polymer scale preventive coating film on its inner wall surfaces, etc. is provided. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugated π bonds and a heterocyclic compound having 5 or more conjugated π bonds, and then coating a second coating liquid a dye and/or pigment on the first layer. The first and second coating liquids are applied by means of steam as a carrier. The second layer has a surface having a contact angle to water of less than 60° after its surface has been kept in contact with a solution of mixture of water and a vinyl chloride monomer in a weight ratio of 1:1 at 50° C for 1 hour. This process can shorten the time for forming the coating film to improve productivity, can improve the effect of preventing adhesion of polymer scale, can make colored particles less mix into polymer products obtained by this process, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.
Addition condensation product, production method and use of same, polymerization vessel, and production method of polymer
申请人:Shin-Etsu Chemical Co., Ltd.
公开号:US11345651B2
公开(公告)日:2022-05-31
Provided is an addition condensation product of an aromatic compound and a carbonyl compound. The addition condensation product includes an aromatic compound dimer in which two composition units derived from the aromatic compounds are bonded via one composition unit derived from the carbonyl compound and an aromatic compound multimer in which each of three or more composition units derived from the aromatic compounds is bonded via one composition unit derived from the carbonyl compound. A ratio of the aromatic compound dimer to the aromatic compound multimer is in the range of 1:75 to 1:1,000.