Patent classifications
C08F2/42
Method for producing polyvinyl alcohol
Provided is a method for producing a polyvinyl alcohol having improved mechanical strength without significantly impairing productivity. A method for producing a polyvinyl alcohol having an average degree of polymerization of 5.0×10.sup.3 or more and 1.5×10.sup.4 or less, the method including steps of: subjecting a vinyl ester-based monomer to suspension polymerization at a polymerization temperature of 10° C. or more and 50° C. or less with a polymerization rate of 10% or more and 70% or less to obtain a vinyl ester-based polymer; dissolving the vinyl ester-based polymer in an alcohol-based solvent; and carrying out a saponification reaction by adding a saponification catalyst to an alcohol-based solution of the dissolved vinyl ester-based polymer.
Method of preparation of a composition comprising a copolymer of methyl methacrylate and methacrylic acid
The present invention relates to a polymeric composition comprising a polymer comprising monomers of methyl methacrylate and methacrylic acid. In particular the present invention relates to a process for making a polymeric composition suitable for moulded objects, said polymeric composition is comprising monomers of methyl methacrylate and methacrylic acid. The present invention concerns also process for making a moulded object comprising a polymer comprising monomers of methyl methacrylate and methacrylic acid. The present invention concerns also moulded object comprising a polymer comprising monomers of methyl methacrylate and methacrylic acid.
ABA TYPE BLOCK CO-POLYMERS FOR TEMPERATURE SENSING AND FLOW METERS
ABA type block copolymers as a new class of temperature sensing polymers with tunable, high temperature coefficient of resistance (TCR). A sensor includes a heater, a thermal insulator between two thermometer layers, the heater generating a thermal gradient within the thermal insulator. The thermometers give an indirect measurement of fluid flow around the sensor, based on their temperature readings. The thermometers are flexible layers including ABA block polymers.
ABA TYPE BLOCK CO-POLYMERS FOR TEMPERATURE SENSING AND FLOW METERS
ABA type block copolymers as a new class of temperature sensing polymers with tunable, high temperature coefficient of resistance (TCR). A sensor includes a heater, a thermal insulator between two thermometer layers, the heater generating a thermal gradient within the thermal insulator. The thermometers give an indirect measurement of fluid flow around the sensor, based on their temperature readings. The thermometers are flexible layers including ABA block polymers.
PROCESS FOR EFFICIENT POLYMER PARTICLE PURGING
A process comprising polymerizing olefin monomers and optionally comonomers in a first reactor vessel, thereby forming a raw product stream comprising polymerized solids, unreacted monomer and optionally comonomer, the polymerized solids comprising olefin polymer, volatile organic compounds (VOC) and catalyst system. Then the polymerized solids are contacted with a catalyst poison selected from carbon monoxide, carbon dioxide, oxygen, water, alcohols, amines, or mixtures thereof, thereby forming a passivated stream. The passivated stream is maintained in an agitated state within a second reactor. The passivated stream within the second reactor is then contacted with a circulating gas comprising unreacted monomer for a residence time, thereby reducing the concentration of VOC in the polymerized solids by at least 10 wt % compared to the level before entering the second reactor, thereby forming a purified olefin polymer solids stream.
PROCESS FOR EFFICIENT POLYMER PARTICLE PURGING
A process comprising polymerizing olefin monomers and optionally comonomers in a first reactor vessel, thereby forming a raw product stream comprising polymerized solids, unreacted monomer and optionally comonomer, the polymerized solids comprising olefin polymer, volatile organic compounds (VOC) and catalyst system. Then the polymerized solids are contacted with a catalyst poison selected from carbon monoxide, carbon dioxide, oxygen, water, alcohols, amines, or mixtures thereof, thereby forming a passivated stream. The passivated stream is maintained in an agitated state within a second reactor. The passivated stream within the second reactor is then contacted with a circulating gas comprising unreacted monomer for a residence time, thereby reducing the concentration of VOC in the polymerized solids by at least 10 wt % compared to the level before entering the second reactor, thereby forming a purified olefin polymer solids stream.
End group functionalization agents for polydiene
The present invention relates to a modified polymer having the structure of Formula (I) and Formula (IV): ##STR00001## wherein A, ##STR00002##
R.sup.1, R.sup.2, R.sup.3, a, and n are as described herein and ##STR00003## wherein ##STR00004##
R, R′, R″, x, and k are as described herein and methods for preparation thereof. The present invention also relates to a compound having the structure of Formula (II): ##STR00005## wherein A, R.sup.1, R.sup.2, R.sup.3, a, and n are as described herein. The present invention also relates to a process for polymerizing unsaturated hydrocarbon monomers.
End group functionalization agents for polydiene
The present invention relates to a modified polymer having the structure of Formula (I) and Formula (IV): ##STR00001## wherein A, ##STR00002##
R.sup.1, R.sup.2, R.sup.3, a, and n are as described herein and ##STR00003## wherein ##STR00004##
R, R′, R″, x, and k are as described herein and methods for preparation thereof. The present invention also relates to a compound having the structure of Formula (II): ##STR00005## wherein A, R.sup.1, R.sup.2, R.sup.3, a, and n are as described herein. The present invention also relates to a process for polymerizing unsaturated hydrocarbon monomers.
Rubber composition, vulcanized rubber, and molded article of said vulcanized rubber
A rubber composition from which a vulcanized rubber simultaneously improved in three characteristics of oil resistance, cold resistance and ozone resistance can be obtained, and a molded article using the vulcanized rubber are provided. The rubber composition contains 50 to 99 parts by mass of a chloroprene rubber containing 0.01 to 20% by mass of an unsaturated nitrile monomer unit and 1 to 50 parts by mass of a non-conjugated diene rubber.
Rubber composition, vulcanized rubber, and molded article of said vulcanized rubber
A rubber composition from which a vulcanized rubber simultaneously improved in three characteristics of oil resistance, cold resistance and ozone resistance can be obtained, and a molded article using the vulcanized rubber are provided. The rubber composition contains 50 to 99 parts by mass of a chloroprene rubber containing 0.01 to 20% by mass of an unsaturated nitrile monomer unit and 1 to 50 parts by mass of a non-conjugated diene rubber.