A process for preparing an acrylic emulsion resin is provided by introducing specific monomers at a certain time during an emulsion polymerization process, dispersion stability and adhesion properties of the acrylic emulsion resin are improved, thereby providing an aqueous acrylic pressure-sensitive adhesive that not only has excellent initial adhesion but also has low viscosity and improved processability, and high adhesion holding power.

A process for preparing an acrylic emulsion resin is provided by introducing specific monomers at a certain time during an emulsion polymerization process, dispersion stability and adhesion properties of the acrylic emulsion resin are improved, thereby providing an aqueous acrylic pressure-sensitive adhesive that not only has excellent initial adhesion but also has low viscosity and improved processability, and high adhesion holding power.

Polymerizable compositions comprising a radically polymerizable resin can be polymerized in the absence of a peroxide initiator and other undesirable components. The polymerizable compositions and methods employ a manganese- or iron-containing salt or organic complex and a 1,3-dioxo compound with one or more other components. The polymerizable compositions have better storage stability and reduced gel time-drift.

Polymerizable compositions comprising a radically polymerizable resin can be polymerized in the absence of a peroxide initiator and other undesirable components. The polymerizable compositions and methods employ a manganese- or iron-containing salt or organic complex and a 1,3-dioxo compound with one or more other components. The polymerizable compositions have better storage stability and reduced gel time-drift.

A method for producing a modified polytetrafluoroethylene, the method including: polymerizing tetrafluoroethylene in an aqueous medium in which a polymer having units based on a fluorine-free monomer is present. The fluorine-free monomer is a monomer represented by formula (1): CH.sub.2═CR.sup.1-L-R.sup.2, where R.sup.1 is a hydrogen atom or an alkyl group, L is a single bond, —CO—O—*, —O—CO—* or —O—, * is a bonding position to R.sup.2, and R.sup.2 is an alkyl group. To the total amount of tetrafluoroethylene supplied to the polymerization, a proportion of the polymer is from 0.001 to 0.050 mass %.

A method for producing a modified polytetrafluoroethylene, the method including: polymerizing tetrafluoroethylene in an aqueous medium in which a polymer having units based on a fluorine-free monomer is present. The fluorine-free monomer is a monomer represented by formula (1): CH.sub.2═CR.sup.1-L-R.sup.2, where R.sup.1 is a hydrogen atom or an alkyl group, L is a single bond, —CO—O—*, —O—CO—* or —O—, * is a bonding position to R.sup.2, and R.sup.2 is an alkyl group. To the total amount of tetrafluoroethylene supplied to the polymerization, a proportion of the polymer is from 0.001 to 0.050 mass %.

A method for producing a modified polytetrafluoroethylene, the method including: polymerizing tetrafluoroethylene in an aqueous medium in which a polymer having units based on a fluorine-free monomer is present. The fluorine-free monomer is a monomer represented by formula (1): CH.sub.2═CR.sup.1-L-R.sup.2, where R.sup.1 is a hydrogen atom or an alkyl group, L is a single bond, —CO—O—*, —O—CO—* or —O—, * is a bonding position to R.sup.2, and R.sup.2 is an alkyl group. To the total amount of tetrafluoroethylene supplied to the polymerization, a proportion of the polymer is from 0.001 to 0.050 mass %.

The present disclosure relates to a styrene copolymer, a thermoplastic resin composition, and methods of preparing the styrene copolymer and the thermoplastic resin composition. More particularly, the present disclosure relates to a styrene copolymer having a low residual oligomer content and excellent transparency due to uniform polymerization of components to be added; and a thermoplastic resin composition including the styrene copolymer and an acrylic rubber graft copolymer and being suitable for a molded article having excellent heat resistance, scratch resistance, and surface appearance.

The present disclosure relates to a styrene copolymer, a thermoplastic resin composition, and methods of preparing the styrene copolymer and the thermoplastic resin composition. More particularly, the present disclosure relates to a styrene copolymer having a low residual oligomer content and excellent transparency due to uniform polymerization of components to be added; and a thermoplastic resin composition including the styrene copolymer and an acrylic rubber graft copolymer and being suitable for a molded article having excellent heat resistance, scratch resistance, and surface appearance.

Provided is a thermoplastic resin composition which includes: a graft copolymer prepared by graft-polymerizing an aromatic vinyl-based monomer and a vinyl cyan-based monomer onto an acrylic rubber polymer having an average particle diameter of 50.0 to 90.0 nm; a matrix copolymer including a C.sub.1-C.sub.3 alkyl (meth)acrylate-based monomer unit, an aromatic vinyl-based monomer unit and a vinyl cyan-based monomer unit; and an additive including a polymer including a C.sub.1-C.sub.3 alkyl (meth)acrylate-based monomer unit, specifically, a thermoplastic resin composition which has improved properties in terms of elongation, processability, weather resistance, colorability, hardness, chemical resistance, scratch resistance, a whitening phenomenon, surface gloss and appearance quality while having excellent basic properties.