52results about How to "Reduce gel" patented technology

A polyamide resin composition comprising: a polyamide (X) having a diamine constituent unit which mainly comprises a metaxylylenediamine unit and a dicarboxylate constituent unit which mainly comprises an adipate constituent unit; and specific amounts of a phosphate-type antioxidant and alkaline component. The polyamide (X) is characterized by a specific terminal group concentration balance and a specific amino group reaction rate. By using the polyamide resin composition, both of the prevention of yellow discoloration and the reduction of gelatinization or fisheye formation can be achieved.

The invention relates to a preparation method of a highly branched polyvinyl alcohol-acrylamide graft copolymer. After dissolving the polyvinyl alcohol in water, blowing nitrogen gas, lowering the temperature, adding a catalyst, reacting for 10-30 minutes, and then adding a monomer mixture solution dropwise , control the dropping time for 30-90 minutes, during which the reaction temperature is controlled between 65°C-95°C, after dropping, control the temperature between 85°C-95°C for 20-30 minutes, add catalyst, and continue at 80°C React at ‑95°C for 15-25 minutes, add catalyst, take samples during the reaction to measure the viscosity, after the viscosity reaches 1500-15000 mPa.s at 25°C, add a terminator to stop the reaction, adjust the solid content, and the product is ready. The graft copolymer of the present invention has high molecular weight, many branched chains, low viscosity, less gel, good retention, and strong anti-interference ability of impurities. As a dry strength agent for papermaking, it can also Satisfactory enhancement effect is achieved.

Disclosed is a production method of polypropylene having high MFR value and excellent product qualities with high productivity. The method enables to produce a propylene polymer by a gas phase process where the reaction heat is removed mainly by the heat of vaporization of liquefied propylene. The method is characterized by using a solid catalyst component (A) which is prepared by contacting components (A1), (A2) and (A3) shown below. Further disclosed are: a propylene polymer produced by the method; a propylene polymer composition; and a molded body of the composition. Component (A1): a solid component containing titanium, magnesium and a halogen as essential components. Component (A2): a vinyl silane compound. Component (A3): an organosilicon compound having an alkoxy group (A3a) and / or a compound having at least two ether bonds (A3b).

The invention relates to an anion aqueous polyurethane dispersoid for leather finishing. The anion aqueous polyurethane dispersoid mainly is mainly prepared by the following raw materials by mass portion: 100 mass portions of polyether polyalcohol, 30 to 80 mass portions of diphenylmethane diisocyanate isomer combination, 6 to 15 mass portions of diol containing carboxyls, 0.5 to 6 mass portions of micromolecular cross-linker and 0.2 to 4 mass portions of amine chain extender; and 0.001 to 1 mass portion of catalyzer is an alternative. The dispersoid has the advantages of good mechanical performance, solvent resistance, hydrolysis resistance, high strength, rapid solidification, etc.

Disclosed are an ABS resin composition and an ABS sheet using the same, wherein the ABS resin composition has an excellent surface quality and enables the manufacture of a sheet with excellent glossiness even in thermoforming. The ABS resin composition according to the invention comprises a) 50-80 weight% of an acrylonitrile-butadiene-styrene (ABS) resin, b) 10-30 weight% of a styrene-acrylonitrile (SAN) copolymer, and c) 10-20 weight% of a rubber resin, wherein the ABS resin is a bulk polymerization-type ABS resin.

The invention relates to a method and equipment for nylon 66 short-flow continuous polymerization. The method comprises the steps of carrying out heating, evaporation, concentration and polycondensation of 30-70% of a nylon 66 salt solution in a normal pressure pre-polypolycondensation tower by adopting a reaction distillation method to obtain a prepolymer with a polymerization degree of 5-50 (preferably 20-40) and equimolar terminal carboxy group and terminal amine group, and allowing the prepolyer to directly produce a polymer with a polymerization degree meeting technical indicators without flash distillation. A falling film devolatilization method is adopted in the polycondensation kettle to accelerate distillation out of condensation water, reduce reaction temperature, shorten reaction time and reduce gel; and the falling liquid film is used to seal and cover the kettle wall to avoid scarring of the kettle wall. Compared with the traditional nylon 66 continuous polymerization device, the method and the equipment provided by the invention has the advantages of short process, large single line scale, less investment, low operating cost, good product quality, long continuous operation cycle, and environmental friendliness.

Provided are: a method for manufacturing a powder coating material whereby a hardened film having excellent weather resistance and few voids (gaps) can be formed; a coated article having a hardened film having excellent weather resistance and few voids, and a method for manufacturing a coated article; and a method for manufacturing a carboxyl-group-containing fluororesin having minimal gelling. A method for manufacturing a powder coating material including a powder (X) comprising a composition ([alpha]) including a curing agent (D) and a fluororesin (A) having carboxyl groups or alkoxysilyl groups and urethane bonds, the method for manufacturing a powder coating material having (a) a step for melt-kneading a mixture including a hydroxyl-group-containing fluororesin (B), an acid anhydride (C1) or a compound (C2) having alkoxysilyl groups and isocyanate groups, and a curing agent (D), and obtaining a mixture comprising the composition ([alpha]), and (b) a step for pulverizing the mixture and obtaining a powder (X).

This disclosure relates to systems and processes for cooling polymer product mixtures manufactured at high pressure. The processes of the invention involve cooling and then subsequently reducing the pressure of the product mixture from the reactor. In the systems of the invention, a product cooler is located downstream of the high pressure reactor and upstream of a high pressure let down valve.

The invention discloses a searching ethylene-vinylacetate copolymer grafted maleic anhydride product which is made of the raw materials with following weight percentage: ethylene-vinylacetate copolymer is 100 percent by weight, maleic anhydride is 0.5 to 5 percent by weight, an initiator is 0.03 to 0.4 percent by weight, and an antioxidant is 0.1 to 0.5 percent by weight. The preparation method is that the raw materials with the weight percentage are added into an extruder, reaction is carried out at the temperature between 150 DEG C and 190 DEG C, and then granulation is extruded to obtain the needed product. The searching ethylene-vinylacetate copolymer grafted maleic anhydride product of the invention can be applied for preparing hot-melt adhesive. The entire preparation process of theproduct has the advantages of high controllability and little gelatinization in the reaction product; the grafting efficiency of maleic anhydride can reach as high as 75 percent. The prepared searching ethylene-vinylacetate copolymer grafted maleic anhydride product can be easily dispersed on the interfaces of multiple blends containing polar polymers, so as to improve the cohesive force among interfaces, thus promoting the overall property of the blends.

The invention discloses a medical grade gas-permeable membrane special material. The medical grade gas-permeable membrane special material is prepared from the following components in parts by weight: 35-75 parts of nanoscale activated composite inorganic mineral powder, 2-6 parts of nano rutile type titanium dioxide, 0.2-2.0 parts of fluorine-containing polymer, 38-78 parts of gas-permeable membrane special resin, 0.5-1.2 parts of antioxidant and 1-2 parts of specially treated aloe juice extract powder or arbutin extract powder, wherein the nanoscale activated composite inorganic mineral powder comprises nanoscale ground calcium carbonate powder, nanoscale talcum powder and a surface active agent. A preparation method of the medical grade gas-permeable membrane special material comprises the following steps: firstly carrying out high-speed mixing on the nanoscale activated composite inorganic mineral powder for removing water; secondly, preparing a gas permeable membrane special material mixture; and thirdly, preparing a gas permeable membrane special material finished product. The medical grade gas-permeable membrane special material has the advantages that raw materials are simple, source of the raw materials is rich, a technology is simplified and cost is low.