An adhesive-backed film with an adhesive layer having thermoplastic or thermoset filaments partially projecting therefrom, to promote fluid egress and repositionability.

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##

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##

A catalyst compound and process for olefin polymerization. The catalyst can be represented by Formula (I):

##STR00001##

wherein: M is a transition metal selected from group 3, 4, or 5 of the Periodic Table of Elements; L is a linking group selected from any one or more difunctional C.sub.1-C.sub.20 hydrocarbyl, aryl or substituted aryl groups; T is an optional bridging group; each X is a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand; R.sup.1 and R.sup.2 are each independently a hydrogen atom or substituted or unsubstituted C.sub.1 to C.sub.20 hydrocarbyl group; R.sup.3, R.sup.5, R.sup.6 and R.sup.7 are each independently a hydrogen atom or a substituted or unsubstituted C.sub.1 to C.sub.20 hydrocarbyl group, and, optionally, any two of R.sup.5, R.sup.6, and R.sup.7 can be joined to form a cyclic structure; R.sup.4 is a substituted or unsubstituted aryl group; and R.sup.8, R.sup.9, R.sup.10, and R.sup.11 are each independently a substituted or unsubstituted C.sub.1 to C.sub.6 hydrocarbyl group and, optionally, R.sup.9 and R.sup.10 are joined to form a cyclic structure.

A catalyst compound and process for olefin polymerization. The catalyst can be represented by Formula (I):

##STR00001##

wherein: M is a transition metal selected from group 3, 4, or 5 of the Periodic Table of Elements; L is a linking group selected from any one or more difunctional C.sub.1-C.sub.20 hydrocarbyl, aryl or substituted aryl groups; T is an optional bridging group; each X is a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand; R.sup.1 and R.sup.2 are each independently a hydrogen atom or substituted or unsubstituted C.sub.1 to C.sub.20 hydrocarbyl group; R.sup.3, R.sup.5, R.sup.6 and R.sup.7 are each independently a hydrogen atom or a substituted or unsubstituted C.sub.1 to C.sub.20 hydrocarbyl group, and, optionally, any two of R.sup.5, R.sup.6, and R.sup.7 can be joined to form a cyclic structure; R.sup.4 is a substituted or unsubstituted aryl group; and R.sup.8, R.sup.9, R.sup.10, and R.sup.11 are each independently a substituted or unsubstituted C.sub.1 to C.sub.6 hydrocarbyl group and, optionally, R.sup.9 and R.sup.10 are joined to form a cyclic structure.

A process for preparing an olefin polymer, including the steps of forming a particulate olefin polymer in a gas-phase polymerization reactor in the presence of a C.sub.3-C.sub.5 alkane as polymerization diluent, separating discharged polyolefin particles from concomitantly discharged gas at a pressure from 1 to 2.2 MPa, degassing the polyolefin particles at a pressure from 0.1 to 0.4 MPa with a gas made from or containing a C.sub.3-C.sub.5 alkane; and transferring the separated gas and the gas from the degassing to a work-up unit operated at a pressure from 0.001 to 0.2 MPa below the pressure of the separation, wherein the gas for degassing is continuously received from the work-up unit.

A process for preparing an olefin polymer, including the steps of forming a particulate olefin polymer in a gas-phase polymerization reactor in the presence of a C.sub.3-C.sub.5 alkane as polymerization diluent, separating discharged polyolefin particles from concomitantly discharged gas at a pressure from 1 to 2.2 MPa, degassing the polyolefin particles at a pressure from 0.1 to 0.4 MPa with a gas made from or containing a C.sub.3-C.sub.5 alkane; and transferring the separated gas and the gas from the degassing to a work-up unit operated at a pressure from 0.001 to 0.2 MPa below the pressure of the separation, wherein the gas for degassing is continuously received from the work-up unit.