The invention relates to the use of low levels of glycols and short chain diols to control air void formation in any polymerization reaction having carbonyl-containing monomers, and preferably carboxylic acid ester monomers, at a level of at least 10% of total monomer, where the monomer has a peak polymerization exotherm temperature of greater than the boiling point of the monomer. The glycols and short chain diols are used in the polymization mixture at levels of 0.5 to 10 weight percent, based on the carboxylic acid ester-containing monomer. It is believed the glycols and short chain diols hydrogen bond with the —(C═O)O— containing monomer to increase the monomer boiling point, and decrease or even eliminate the formation of air voids due to monomer boiling. The invention is especially useful in polymerization of methyl methacrylate polymers and copolymers, either neat, or as a polymer composite system.

The invention relates to the use of low levels of glycols and short chain diols to control air void formation in any polymerization reaction having carbonyl-containing monomers, and preferably carboxylic acid ester monomers, at a level of at least 10% of total monomer, where the monomer has a peak polymerization exotherm temperature of greater than the boiling point of the monomer. The glycols and short chain diols are used in the polymization mixture at levels of 0.5 to 10 weight percent, based on the carboxylic acid ester-containing monomer. It is believed the glycols and short chain diols hydrogen bond with the —(C═O)O— containing monomer to increase the monomer boiling point, and decrease or even eliminate the formation of air voids due to monomer boiling. The invention is especially useful in polymerization of methyl methacrylate polymers and copolymers, either neat, or as a polymer composite system.

The invention relates to the use of low levels of glycols and short chain diols to control air void formation in any polymerization reaction having carbonyl-containing monomers, and preferably carboxylic acid ester monomers, at a level of at least 10% of total monomer, where the monomer has a peak polymerization exotherm temperature of greater than the boiling point of the monomer. The glycols and short chain diols are used in the polymization mixture at levels of 0.5 to 10 weight percent, based on the carboxylic acid ester-containing monomer. It is believed the glycols and short chain diols hydrogen bond with the —(C═O)O— containing monomer to increase the monomer boiling point, and decrease or even eliminate the formation of air voids due to monomer boiling. The invention is especially useful in polymerization of methyl methacrylate polymers and copolymers, either neat, or as a polymer composite system.

Provided is a rubber composition being excellent in cut resistance while maintaining good elongation fatigue resistance. The rubber composition of the present disclosure contains a rubber component containing 70% by mass or more of natural rubber, a filler containing at least silica, and a cyclic polyol compound having a hydrocarbyl group of 0.1 parts by mass to 2 parts by mass with respect to 100 parts by mass of the natural rubber in the rubber component.

Provided is a rubber composition being excellent in cut resistance while maintaining good elongation fatigue resistance. The rubber composition of the present disclosure contains a rubber component containing 70% by mass or more of natural rubber, a filler containing at least silica, and a cyclic polyol compound having a hydrocarbyl group of 0.1 parts by mass to 2 parts by mass with respect to 100 parts by mass of the natural rubber in the rubber component.

Provided is a polycarbonate-polyorganosiloxane copolymer, including a polyorganosiloxane block (A-1) including a specific structural unit and a polycarbonate block (A-2) formed of a specific repeating unit.

Provided is a polycarbonate-polyorganosiloxane copolymer, including a polyorganosiloxane block (A-1) including a specific structural unit and a polycarbonate block (A-2) formed of a specific repeating unit.

An object of the present invention is to provide an epoxy resin composition that can be preferably used for prepreg and fiber reinforced composite material applications and is excellent in elastic modulus, strength, and pot life. The present invention is the epoxy resin composition including the following components [A] to [C] and satisfying the following conditions (1) to (4):

[A]: epoxy resin
[B]: aromatic diamine
[C]: a compound having a boiling point of 130° C. or more and a molecular weight m of 50 or more and 250 or less, the compound having no epoxy group in the molecule and having substantially no curing ability of an epoxy resin (1): the ratio H/E between the amount by mole, E, of the epoxy group in the component [A] and the amount by mole, H, of active hydrogen in the component [B] is 0.50 or more and 1.30 or less. (2): at least a part of the component [C] satisfies 0.10 or more and 0.60 or less in a ratio m/M of a molecular weight m thereof to a theoretical molecular weight between crosslinking points, M, of a cured product of the epoxy resin composition. (3): the ratio C/E of the amount by mole, E, for epoxy groups of the component [A] to the amount by mole, C, of the component [C] satisfying the condition (2) is 0.01 or more and 0.20 or less; and (4): the viscosity at 70° C. for 2 hours is 5.0 times or less the initial viscosity at 70° C.

An object of the present invention is to provide an epoxy resin composition that can be preferably used for prepreg and fiber reinforced composite material applications and is excellent in elastic modulus, strength, and pot life. The present invention is the epoxy resin composition including the following components [A] to [C] and satisfying the following conditions (1) to (4):

[A]: epoxy resin
[B]: aromatic diamine
[C]: a compound having a boiling point of 130° C. or more and a molecular weight m of 50 or more and 250 or less, the compound having no epoxy group in the molecule and having substantially no curing ability of an epoxy resin (1): the ratio H/E between the amount by mole, E, of the epoxy group in the component [A] and the amount by mole, H, of active hydrogen in the component [B] is 0.50 or more and 1.30 or less. (2): at least a part of the component [C] satisfies 0.10 or more and 0.60 or less in a ratio m/M of a molecular weight m thereof to a theoretical molecular weight between crosslinking points, M, of a cured product of the epoxy resin composition. (3): the ratio C/E of the amount by mole, E, for epoxy groups of the component [A] to the amount by mole, C, of the component [C] satisfying the condition (2) is 0.01 or more and 0.20 or less; and (4): the viscosity at 70° C. for 2 hours is 5.0 times or less the initial viscosity at 70° C.

An object of the present invention is to provide an epoxy resin composition that can be preferably used for prepreg and fiber reinforced composite material applications and is excellent in elastic modulus, strength, and pot life. The present invention is the epoxy resin composition including the following components [A] to [C] and satisfying the following conditions (1) to (4):

[A]: epoxy resin
[B]: aromatic diamine
[C]: a compound having a boiling point of 130° C. or more and a molecular weight m of 50 or more and 250 or less, the compound having no epoxy group in the molecule and having substantially no curing ability of an epoxy resin (1): the ratio H/E between the amount by mole, E, of the epoxy group in the component [A] and the amount by mole, H, of active hydrogen in the component [B] is 0.50 or more and 1.30 or less. (2): at least a part of the component [C] satisfies 0.10 or more and 0.60 or less in a ratio m/M of a molecular weight m thereof to a theoretical molecular weight between crosslinking points, M, of a cured product of the epoxy resin composition. (3): the ratio C/E of the amount by mole, E, for epoxy groups of the component [A] to the amount by mole, C, of the component [C] satisfying the condition (2) is 0.01 or more and 0.20 or less; and (4): the viscosity at 70° C. for 2 hours is 5.0 times or less the initial viscosity at 70° C.