A binder for glass fiber nonwoven comprising a polyvinyl alcohol, the polyvinyl alcohol having a shape with an aspect ratio of 1.9 to 30 and a degree of saponification of 99.0 mol % or more.

A binder for glass fiber nonwoven comprising a polyvinyl alcohol, the polyvinyl alcohol having a shape with an aspect ratio of 1.9 to 30 and a degree of saponification of 99.0 mol % or more.

A dispersion stabilizer for suspension polymerization is provided that includes a vinyl alcohol-based polymer (A), wherein a 0.1 mass % concentration aqueous solution of the polymer (A) has an absorbance (a1) of less than 0.25 at a wavelength of 280 nm, the aqueous solution has an absorbance (a2) of less than 0.030 at a wavelength of 320 nm, the polymer (A) has a degree of saponification of not less than 68 mol % and not more than 98 mol %, the polymer (A) has a viscosity-average degree of polymerization of more than 1500 and less than 4500, and the polymer (A) in powder form has a YI value of not less than 5. The dispersion stabilizer is capable of producing a vinyl-based resin that is excellent in polymerization stability, has a small particle size, and has an improved bulk density.

A dispersion stabilizer for suspension polymerization is provided that includes a vinyl alcohol-based polymer (A), wherein a 0.1 mass % concentration aqueous solution of the polymer (A) has an absorbance (a1) of less than 0.25 at a wavelength of 280 nm, the aqueous solution has an absorbance (a2) of less than 0.030 at a wavelength of 320 nm, the polymer (A) has a degree of saponification of not less than 68 mol % and not more than 98 mol %, the polymer (A) has a viscosity-average degree of polymerization of more than 1500 and less than 4500, and the polymer (A) in powder form has a YI value of not less than 5. The dispersion stabilizer is capable of producing a vinyl-based resin that is excellent in polymerization stability, has a small particle size, and has an improved bulk density.

The present invention relates to a RAFT agent of formula (I) where R.sub.1, R.sub.2 and R.sub.3 are each independently selected from H and optionally substituted alkyl.

##STR00001##

A dispersion stabilizer for suspension polymerization of vinyl compounds comprising a vinyl alcohol polymer (A) which has a saponification degree of 30 mol % or more and less than 60 mol % and a viscosity-average polymerization degree (P) of more than 200 and less than 600, and has a terminal alkyl group having 6 to 18 carbon atoms, and in which a content of monomer units having an oxyalkylene group is 0.3 mol % or less and the relationship between the viscosity-average polymerization degree (P) and a modification rate (S) (mol %) of the alkyl group satisfies Formula (1). Thus, there can be provided a dispersion stabilizer for suspension polymerization with which, during suspension polymerization of vinyl compounds including vinyl chloride, even when it is used in a small amount, the absorbency of a plasticizer is high, resulting in easy processing and formation of coarse particles is little and the remaining monomer components can be easily removed.
50≦S×P/1.880<100  (1)

A dispersion stabilizer for suspension polymerization of vinyl compounds comprising a vinyl alcohol polymer (A) which has a saponification degree of 30 mol % or more and less than 60 mol % and a viscosity-average polymerization degree (P) of more than 200 and less than 600, and has a terminal alkyl group having 6 to 18 carbon atoms, and in which a content of monomer units having an oxyalkylene group is 0.3 mol % or less and the relationship between the viscosity-average polymerization degree (P) and a modification rate (S) (mol %) of the alkyl group satisfies Formula (1). Thus, there can be provided a dispersion stabilizer for suspension polymerization with which, during suspension polymerization of vinyl compounds including vinyl chloride, even when it is used in a small amount, the absorbency of a plasticizer is high, resulting in easy processing and formation of coarse particles is little and the remaining monomer components can be easily removed.
50≦S×P/1.880<100  (1)

Embodiments of organic peroxide formulations provide longer scorch time protection and require fewer additives. The peroxide formulations may include, for example, at least one organic peroxide, at least one nitroxide-containing compound (e.g., 4-hydroxy-TEMPO), and at least one quinone-containing compound (e.g., mono-tert-butylhydroquinone). Embodiments of the present invention relate to organic peroxide compositions comprising scorch retarders. Embodiments of the invention also relate to crosslinkable elastomer compositions, processes for curing the elastomers, and products made by such processes.

Embodiments of organic peroxide formulations provide longer scorch time protection and require fewer additives. The peroxide formulations may include, for example, at least one organic peroxide, at least one nitroxide-containing compound (e.g., 4-hydroxy-TEMPO), and at least one quinone-containing compound (e.g., mono-tert-butylhydroquinone). Embodiments of the present invention relate to organic peroxide compositions comprising scorch retarders. Embodiments of the invention also relate to crosslinkable elastomer compositions, processes for curing the elastomers, and products made by such processes.

The present invention relates generally to a polyvinyl alcohol composition having higher amorphous polyvinyl alcohol polymer content, a process for making such a polyvinyl alcohol composition, and various end uses thereof.