A flame-retardant antimicrobial agent is a polymer microsphere with the surface grafted thereof with a guanidine salt. The polymer microsphere has a cross-linked structure composed of a structural unit A derived from maleic anhydride, a structural unit B derived from a monomer M, and a structural unit C derived from a cross-linking agent. The monomer M is selected from a C.sub.4-C.sub.9 aliphatic olefin or a mixture thereof, and the guanidine salt comprises at least one guanidine salt having the property of flame resistance. The flame-retardant antimicrobial agent has both a good antimicrobial effect and a good flame-retardant effect. A flame-retardant antimicrobial thermoplastic resin composition containing the flame-retardant antimicrobial agent also has a good flame-retardant and antimicrobial performance and a good overall performance.

A flame-retardant antimicrobial agent is a polymer microsphere with the surface grafted thereof with a guanidine salt. The polymer microsphere has a cross-linked structure composed of a structural unit A derived from maleic anhydride, a structural unit B derived from a monomer M, and a structural unit C derived from a cross-linking agent. The monomer M is selected from a C.sub.4-C.sub.9 aliphatic olefin or a mixture thereof, and the guanidine salt comprises at least one guanidine salt having the property of flame resistance. The flame-retardant antimicrobial agent has both a good antimicrobial effect and a good flame-retardant effect. A flame-retardant antimicrobial thermoplastic resin composition containing the flame-retardant antimicrobial agent also has a good flame-retardant and antimicrobial performance and a good overall performance.

Provided is a polyethylene powder having a density of 910 kg/m.sup.3 or more and less than 935 kg/m.sup.3 and an average particle diameter of 50 μm or more and less than 140 μm, wherein the polyethylene powder contains a particle having a particle diameter of 60 μm and a particle having a particle diameter of 100 μm, the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 2.0 MPa or more and less than 5.0 MPa, and the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 0.5 times or more and less than 1.3 times the compressive strength at 10% displacement of the particle having a particle diameter of 100 μm.

Provided is a polyethylene powder having a density of 910 kg/m.sup.3 or more and less than 935 kg/m.sup.3 and an average particle diameter of 50 μm or more and less than 140 μm, wherein the polyethylene powder contains a particle having a particle diameter of 60 μm and a particle having a particle diameter of 100 μm, the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 2.0 MPa or more and less than 5.0 MPa, and the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 0.5 times or more and less than 1.3 times the compressive strength at 10% displacement of the particle having a particle diameter of 100 μm.

Disclosed is a catalyst for olefin polymerization, comprising a main catalyst and a cocatalyst; the main catalyst is a bisphenol metal complex represented by formula I, and the cocatalyst comprises an organoaluminum compound; in formula I, R.sub.1, R.sub.1′, R.sub.2, R.sub.2′ are the same or different, and are each independently selected from hydrogen and a substituted or unsubstituted C.sub.1-C.sub.20 hydrocarbyl; R.sub.3-R.sub.7, R.sub.3′-R.sub.7′ are the same or different, and are each independently selected from hydrogen and a substituted or unsubstituted C.sub.1-C.sub.20 hydrocarbyl; R.sub.8 and R.sub.9 are the same or different, and are each independently selected from hydrogen or a substituted or unsubstituted C.sub.1-C.sub.20 hydrocarbyl; M and M′ are the same or different, and are selected from Group IV metals; and X is halogen;

##STR00001##

Disclosed is a catalyst for olefin polymerization, comprising a main catalyst and a cocatalyst; the main catalyst is a bisphenol metal complex represented by formula I, and the cocatalyst comprises an organoaluminum compound; in formula I, R.sub.1, R.sub.1′, R.sub.2, R.sub.2′ are the same or different, and are each independently selected from hydrogen and a substituted or unsubstituted C.sub.1-C.sub.20 hydrocarbyl; R.sub.3-R.sub.7, R.sub.3′-R.sub.7′ are the same or different, and are each independently selected from hydrogen and a substituted or unsubstituted C.sub.1-C.sub.20 hydrocarbyl; R.sub.8 and R.sub.9 are the same or different, and are each independently selected from hydrogen or a substituted or unsubstituted C.sub.1-C.sub.20 hydrocarbyl; M and M′ are the same or different, and are selected from Group IV metals; and X is halogen;

##STR00001##

An object of the present invention is to provide a composition capable of allowing for production of a crosslinked foamed product suitable for applications of footwear parts such as soles and excellent in properties such as lightweight properties, heat shrinkability, compression set and mechanical strength in a well-balanced manner, a foamed product using the composition and a footwear part using the same. An ethylene copolymer composition including an ethylene copolymer (A) satisfying all the following requirements (A-a), (A-b), (A-c) and (A-d), ethylene/α-olefin having 3 to 20 carbon atoms/non-conjugated polyene copolymer rubber (B), and, if necessary, an ethylene/polar monomer copolymer (C); (A-a) a vinyl group content per 1,000 carbon atoms is 0.025 to 0.3, (A-b) MFR.sub.10/MFR.sub.2.16 is 7 to 20, (A-c) a density is 0.850 to 0.910 g/cm.sup.3, and (A-d) a melt flow rate is 0.01 to 200 g/10 min.

An object of the present invention is to provide a composition capable of allowing for production of a crosslinked foamed product suitable for applications of footwear parts such as soles and excellent in properties such as lightweight properties, heat shrinkability, compression set and mechanical strength in a well-balanced manner, a foamed product using the composition and a footwear part using the same. An ethylene copolymer composition including an ethylene copolymer (A) satisfying all the following requirements (A-a), (A-b), (A-c) and (A-d), ethylene/α-olefin having 3 to 20 carbon atoms/non-conjugated polyene copolymer rubber (B), and, if necessary, an ethylene/polar monomer copolymer (C); (A-a) a vinyl group content per 1,000 carbon atoms is 0.025 to 0.3, (A-b) MFR.sub.10/MFR.sub.2.16 is 7 to 20, (A-c) a density is 0.850 to 0.910 g/cm.sup.3, and (A-d) a melt flow rate is 0.01 to 200 g/10 min.

New polypropylene composition which combines low sealing initiation temperature (SIT), high hot-tack and good mechanical properties, like high dart drop strength (DDI), and its use especially for film applications.

New polypropylene composition which combines low sealing initiation temperature (SIT), high hot-tack and good mechanical properties, like high dart drop strength (DDI), and its use especially for film applications.