Patent application number | Description | Published |
20090326171 | PROCESS FOR THE PREPARATION OF HIGH PERFORMANCE POLYPROPYLENE - The invention discloses a process for preparing high-performance propylene polymers, the process utilizing a high activity, highly stereoselective Ziegler-Natta catalyst and two or more stages of polymerization carried out under different hydrogen concentrations to prepare propylene polymers having broad molecular weight distribution, wherein non-unifomess of isotacticity of molecular chains of the final propylene polymers is improved by adjusting or controlling stereoselectivity of catalytic active sites under different hydrogen concentrations, namely, making the low molecular weight fraction of the polymers having a higher isotacticity and making the high molecular weight fraction of the polymers having a lower isotacticity, thereby overcoming the drawbacks of the propylene polymers having broad molecular weight distribution known in the art. The resulting final polymers have excellent combined properties, in particular, remarkably improved mechanical properties. | 12-31-2009 |
20130158198 | EPOXY RESIN COMPOSITION AND ITS PREPARING METHOD - The invention relates to an epoxy resin composition and preparation thereof. The composition comprises the following blended components: 100 weight parts of epoxy resins; 30 to 120 weight parts of anhydride curing agents; 1 to 45 weight parts of powdery nitrile rubbers; no curing accelerator is included in the composition. The composition of the invention has both higher heat resistance and higher toughness, and is suitable for the fields which require high heat resistance, such as circuit board, electronics packaging, binder and electrical insulating coating etc. | 06-20-2013 |
20130225713 | COMPOSITE POWDER, PREPARATION AND USE THEREOF - The present invention relates to a composite powder, preparation and use thereof. The composite powder according to the present invention is prepared by intimately mixing an irradiated or non-irradiated rubber latex with a slurry of inorganic particles in a ratio corresponding to that of rubber particles to inorganic particles in the composite powder according to the present invention, and then drying the resultant mixture. The composite powder according to the present invention comprises agglomerates composed of powdery rubber particles and inorganic particles, with inorganic particles being uniformly distributed either inside the agglomerats or both inside the agglomerates and on the surfaces thereof. The composite powder according to the present invention can be easily dispersed in plastic matrixes and thus can be compounded with plastics to produce toughened plastics and thermoplastic elastomers. | 08-29-2013 |
20140054512 | CONDUCTIVE FULL VULCANIZED THERMOPLASTIC ELASTOMER AND ITS PREPARATION METHOD - The invention provides a conductive full vulcanized thermoplastic elastomer and its preparation method, and relates to the technical field of full vulcanized thermoplastic elastomer. The full vulcanized thermoplastic elastomer is obtained by melt-blending components including rubber particles having crosslinking structure with mean particle diameter of 0.02 to 1 μm, carbon nanotubes as conductive fillers and thermoplastic plastics once, wherein the weight ratio of the rubber particles and the thermoplastic plastics is from 30:70 to 75:25 and the content of conductive fillers is from 0.3 to 10 weight parts based on the total weight of rubber particles and thermoplastic plastics of 100 weight parts. The resulting conductive full vulcanized thermoplastic elastomers have low content of conductive fillers and excellent combination performances. It can be prepared by conventional rubber processing methods and can be used to produce electronic production equipment, means, electronic instrument, instrument housing and decorative materials of clean production workshop having static resistance, electro magnetic interference resistance and clean requirement. | 02-27-2014 |
20140121339 | POLYPROPYLENE WITH NARROW MOLECULAR WEIGHT DISTRIBUTION RANGE AND PROCESSES FOR PREPARATION THEREOF - Disclosed herein are a polypropylene with narrow molecular weight distribution and a process for preparing the same in a reactor using a Ziegler-Natta catalyst. | 05-01-2014 |
20140296439 | MODIFIED RUBBER MASTERBATCH, AND RUBBER COMPOSITION AND VULCANIZED RUBBER PRODUCED THEREFROM, AND THE PREPARATION PROCESSES FOR THEM - The present application relates to a modified rubber masterbatch and preparation method thereof, rubber composition prepared therewith and vulcanized rubber and preparation method thereof. The modified rubber component comprises uncrosslinked rubber and rubber particles having crosslinked structure dispersed therein, wherein the rubber particles having crosslinked structure are synthetic rubber particles and/or natural rubber particles, have an average particle size of 20-500 nm and a gel content of 60% by weight or higher, and wherein the uncrosslinked rubber is styrene-butadiene rubber. The weight ratio of the rubber particles having crosslinked structure to the uncrosslinked rubber is greater than 20:80 and less than or equal to 80:20. The rubber composition comprises a blend of modified rubber component and base rubber, in which the modified rubber masterbatch is present in an amount of 1 to 70 parts by weight, relative to per 100 parts by weight of the base rubber. The vulcanized rubber of the rubber composition has not only low rolling resistance and excellent wet skid resistance, but also excellent wear resistance, and thus can be used for producing high performance tread rubber. | 10-02-2014 |
20150105490 | RUBBER COMPOSTION, PREPARATION METHOD AND VULCANIZED RUBBER THEREOF - The present application relates to a rubber composition, preparation method and vulcanized rubber thereof. The rubber composition comprises uncrosslinked rubber and rubber particles having crosslinked structure dispersed therein, wherein the rubber particles having crosslinked structure are synthetic rubber particles and/or natural rubber particles, e.g. one or more selected from the group consisting of natural rubber particles, styrene-butadiene rubber particles, carboxylated styrene-butadiene rubber particles, nitrile butadiene rubber particles, carboxylated nitrile butadiene rubber particles, chloroprene rubber particles, polybutadiene rubber particles, silicone rubber particles or acrylic rubber particles, styrene-butadiene-vinylpyridine rubber particles and the like, with an average particle size of 20 to 500 nm and a gel content of 60% by weight or higher, and the uncrosslinked rubber is styrene-butadiene rubber, and wherein the weight ratio of the rubber particles having crosslinked structure to the uncrosslinked rubber is 1:99-20:80. The rubber composition is obtained by mixing the components comprising uncrosslinked rubber latex and latex of rubber particles having crosslinked structure and then coagulating them. The latex of rubber particles having crosslinked structure is a rubber latex after radiation crosslinking. The vulcanized rubber of the rubber composition can be improved simultaneously in rolling resistance, wet skid resistance and wear resistance and thus can be used as high performance vehicle tread rubber. | 04-16-2015 |
20150231612 | Supported Catalyst, Its Activated Form, and their Preparation and Use - A supported catalyst and preparation method thereof, the catalyst comprising an organic polymer material carrier and Raney alloy particles supported on the organic polymer material carrier, wherein substantially all of the Raney alloy particles are partially embedded in the organic polymer material carrier. The catalyst can be used in hydrogenation, dehydrogenation, amination, dehalogenation or desulfuration reactions. | 08-20-2015 |