The present invention provides a crosslinked propylene-based elastomer having an isotactic propylene triad tacticity of from 65 to 95%, a melting point by DSC equal to or less than 110° C., a heat of fusion of from 5 J/g to 50 J/g, and a haze % per 100 mil thickness of 95 or less, and comprising at least 75 wt % propylene-derived units, at least 5 wt % ethylene-derived units, and optionally 10 wt % or less of diene-derived units. In an embodiment, the present invention is a blend of a continuous phase of the crosslinked propylene-based elastomer and a dispersed phase of a crystalline polymeric compound. The present invention also provides elastomeric compositions comprising a crosslinked propylene-based elastomer as described herein and 100 parts by weight or less of a pigment per 100 parts of polymer. The present invention also provides films, fibers, nonwovens, molded objects, and extruded forms which include any of the inventive compositions described herein.

Transparent and translucent crosslinked propylene-based elastomers, and their production and use

The present invention is directed generally to the use of propylene-based elastomers in articles. The propylene-based elastomers have isotactic polypropylene crystallinity, a melting point by DSC of 110° C. or less, a heat of fusion of from 5 to 50 J/g, and comprise at least 75 wt % propylene-derived units, at least 6 wt % ethylene-derived units, and optionally diene-derived units. The present invention is also directed to processes for making articles comprising propylene-based elastomers.

Articles comprising propylene-based elastomers

A method for producing a rubber composition crosslinked to a crosslinking degree of 50% or higher by mixing a crosslinkable rubber (A) and a thermoplastic resin (B) and crosslinking the mixture with a crosslinking agent (C), wherein the crosslinking agent (C) is divided and added in parts to sequentially carry out the crosslinking in which the crosslinking is carried out to a crosslinking degree of 5-45% by the first addition of the crosslinking agent (C) and furthermore the crosslinking is carried out to a crosslinking degree of 50% or higher by further addition of the crosslinking agent (C).

Method for producing rubber composition

A propylene resin composition prepared by dynamically heat-treating a blend of (A) 100 parts by weight of a propylene-α-olefin block copolymer having a ratio (θ1/θ2) of 3.5 to 8 (wherein θ1 and θ2 represent melt viscosities under the shear rate of, respectively, 10?1sec-1 and 102sec-1? as measured by the slit-die method) with (B) 0.005-2 parts by weight of an organic peroxide. The composition has a melt flow rate (as measured at the temperature of 230 °C under the load of 2.16 kg according to JIS K7210) of 50-300g/10 mn and a main endothermic peak temperature Tmp of 120-150 °C in the melting temperature curve, a main exothermic peak temperature Tcp of 85-105 °C in the crystallization temperature curve, and a half width of the Tcp of 5 °C or above, each according to differential scanning calorimetry.

Propylene resin composition and molded article thereof

PURPOSE: To prepare a polyolefin composition having improved impact resistance in a short time, by reacting a composition comprising crystalline polypropylene, an olefin rubber, and an organic peroxide, in an extruder under specific condition. CONSTITUTION: (a) 80W97 parts by wt. of crystalline polypropylene, e.g. ethylene- propylene random copolymer with an ethylene content of 0.5W3.5 wt.%, ethylene- propylene block copolymer with an ethylene content of 3W30 wt. %, etc. is kneaded with (b) 3W20 parts by wt. of an olefin rubber, e.g. ethylene-propylene copolymer rubber, ethylene-propylene-conjugated diene terpolymer rubber, etc. at 160W280°C to give 100 parts by wt. of a polymer blend (A). A mixture of the polymer blend (A) thus obtained and (B) 0.01W1.0 part by wt; of an organic peroxide having a temperature to give a half-life of 1 min of 160W260°C is reacted in an extruder at a temperature ranging from the melting one to the decomposition one (180W 280°C ) of the mixture for 2W8 min COPYRIGHT: (C)1979,JPO&Japio

Preparation of polypropylene composition having improved impact resistance

PURPOSE: To prepare a thermoplastic elastomer with good elastic properties by the reaction of a curing agent with an intimate blend of a monoolefin copolymer rubber which was previously blended with a crystalline resin. COPYRIGHT: (C)1977,JPO&Japio

Preparation of thermoplastic elastomer

PURPOSE: To produce the titled resin compsn. having excellent injection moldability and mechanical strength, by granulating a mixture of polypropylene, an olefin copolymer rubber and a mineral oil, adding an org. peroxide thereto, and then granulating the mixture while kneading. CONSTITUTION: 50W80pts.wt. crystalline propylene homopolymer resin (A) having an MFR of 0.5W3 at 230°C, 50W20pts.wt., monoolefin compolymer rubber (B) such as an ethylene/propylene copolymer rubber, and 5W20pts.wt. (per 100pts.wt. of the combined amount of components A and B) mineral oil (C) are melt-mixed for 5W10min by means of a roll mill, cooled and granulated. The granules and an org. peroxide such as 2,5-dimethyl-2,5-di(t-butylperoxy) hexane are mixed together to deposit 0.05W0.5wt% org. peroxide on the surfaces of the granules. Then the resulting granules are kneaded at 170W250°C by using an extruder type kneader, and eextruded through a die to continuously granulate them. COPYRIGHT: (C)1983,JPO&Japio

Shuichi Nakayama

Papers

Preparation of thermoplastic elastomer

Production of non-rigid polyolefin resin composition