An eight-arm star-shaped thermoplastic elastomer copolymer and a preparation method therefor; a polystyrene-polyisoprene lithium compound and a polystyrene/diphenylethylene-polyisoprene lithium compound are synthesized by using active anionic polymerization, and the compounds are used for a coupling reaction with octenyl polyhedral oligomeric silasesquioxane to obtain the copolymer. The method has the characteristics of convenient operation, high reaction efficiency, mild reaction conditions, and few side reactions. The structure and molecular weight of the prepared eight-arm star-shaped polymer are controllable, and the molecular weight distribution is narrow. A polymer segment obtained by the copolymerization of diphenylethylene (DPE) and styrene (St) is used as a hard segment, which enables the eight-arm star-shaped thermoplastic elastomer copolymer to have more outstanding mechanical properties. At the same time, a polymer segment composed of DPE and St units has a higher glass transition temperature than polystyrene, which increases the upper limit usage temperature of the eight-arm star-shaped copolymer.

An eight-arm star-shaped thermoplastic elastomer copolymer and a preparation method therefor; a polystyrene-polyisoprene lithium compound and a polystyrene/diphenylethylene-polyisoprene lithium compound are synthesized by using active anionic polymerization, and the compounds are used for a coupling reaction with octenyl polyhedral oligomeric silasesquioxane to obtain the copolymer. The method has the characteristics of convenient operation, high reaction efficiency, mild reaction conditions, and few side reactions. The structure and molecular weight of the prepared eight-arm star-shaped polymer are controllable, and the molecular weight distribution is narrow. A polymer segment obtained by the copolymerization of diphenylethylene (DPE) and styrene (St) is used as a hard segment, which enables the eight-arm star-shaped thermoplastic elastomer copolymer to have more outstanding mechanical properties. At the same time, a polymer segment composed of DPE and St units has a higher glass transition temperature than polystyrene, which increases the upper limit usage temperature of the eight-arm star-shaped copolymer.

A polypropylene composition comprising the following components in parts by weight: 40-99 parts of a polypropylene resin; 15-30 parts of an ethylene-α olefin copolymer; 0.2-1 part of an antimicrobial agent; and 1-3 parts of a polypropylene grafted polydimethylsiloxane is provided. By controlling a melt index of an elastomer, distribution of the modified polydimethylsiloxane and antimicrobial agent can be improved, thus improving antimicrobial and stain-resistant effects of the polypropylene composition.

A polypropylene composition comprising the following components in parts by weight: 40-99 parts of a polypropylene resin; 15-30 parts of an ethylene-α olefin copolymer; 0.2-1 part of an antimicrobial agent; and 1-3 parts of a polypropylene grafted polydimethylsiloxane is provided. By controlling a melt index of an elastomer, distribution of the modified polydimethylsiloxane and antimicrobial agent can be improved, thus improving antimicrobial and stain-resistant effects of the polypropylene composition.

The resin composition according to one aspect is a resin composition containing a polyamic acid and a solvent, wherein the polyamic acid has a repeating unit represented by the following general formula (1) in a molecular chain, and the molecular chain has a structure represented by the following general formula (2) at one end or both ends. The proportion of the structure represented by the following general formula (2) relative to 1 mol of the repeating unit represented by the following general formula (1) is 0.001 mol or more and 0.1 mol or less. In the following general formulas, R.sup.1 is a tetravalent organic group; R.sup.2 is a divalent organic group; and R.sup.3 is an organic group having 15 or less carbon atoms.

##STR00001##

The resin composition according to one aspect is a resin composition containing a polyamic acid and a solvent, wherein the polyamic acid has a repeating unit represented by the following general formula (1) in a molecular chain, and the molecular chain has a structure represented by the following general formula (2) at one end or both ends. The proportion of the structure represented by the following general formula (2) relative to 1 mol of the repeating unit represented by the following general formula (1) is 0.001 mol or more and 0.1 mol or less. In the following general formulas, R.sup.1 is a tetravalent organic group; R.sup.2 is a divalent organic group; and R.sup.3 is an organic group having 15 or less carbon atoms.

##STR00001##

Pressure sensitive adhesives that include hyperbranched silsesquioxane-core polymers are described. Also described are various methods for producing the noted polymers and pressure sensitive adhesives. In addition, a variety of articles including tapes utilizing the pressure sensitive adhesives are described.

Provided is a polycarbonate-polyorganosiloxane copolymer including polycarbonate blocks (A-1) each formed of a specific repeating unit and polyorganosiloxane blocks (A-2) each containing a specific repeating unit, wherein the polycarbonate-polyorganosiloxane copolymer satisfies the following expression (F1a):
15≤wM1  (F1a)
wherein wM1 represents the average content of the polyorganosiloxane blocks (A-2) in polycarbonate-polyorganosiloxane copolymers each having a molecular weight determined by using a polycarbonate as a conversion reference of from 56,000 or more to 200,000 or less among polycarbonate-polyorganosiloxane copolymers obtained through the separation of the polycarbonate-polyorganosiloxane copolymer by gel permeation chromatography.

Provided is a polycarbonate-polyorganosiloxane copolymer including polycarbonate blocks (A-1) each formed of a specific repeating unit and polyorganosiloxane blocks (A-2) each containing a specific repeating unit, wherein the polycarbonate-polyorganosiloxane copolymer satisfies the following expression (F1a):
15≤wM1  (F1a)
wherein wM1 represents the average content of the polyorganosiloxane blocks (A-2) in polycarbonate-polyorganosiloxane copolymers each having a molecular weight determined by using a polycarbonate as a conversion reference of from 56,000 or more to 200,000 or less among polycarbonate-polyorganosiloxane copolymers obtained through the separation of the polycarbonate-polyorganosiloxane copolymer by gel permeation chromatography.

An object of the present invention is to provide a polyorganosiloxane-containing graft copolymer powder capable of providing a resin composition and a molded article which are excellent in balance between colorability and mechanical properties such as impact resistance. The polyorganosiloxane-containing graft copolymer powder according to the present invention is a graft copolymer powder obtained by graft-polymerizing a mixture (B) of a vinyl monomer (b1) having an epoxy group and another vinyl monomer (b2) to a rubber (A) containing a polyorganosiloxane, wherein the content of the polyorganosiloxane (A1) contained in the rubber (A) is 12 to 50% by mass, the mass average particle diameter of the polyorganosiloxane-containing graft copolymer powder is 300 to 2000 nm, and the epoxy equivalent of the polyorganosiloxane-containing graft copolymer powder is 2500 to 7800 g/eq.