133results about How to "Low gel content" patented technology

The present invention relates to an acrylic pressure sensitive adhesive composition comprising (meth)acrylic copolymers including alkyl(meth)acrylic acid ester monomer having 1˜12 carbon atoms of alkyl group, characterized in that the gel content is 10˜55%, the swelling ratio is 30˜110, the weight average molecular weight of sol eluted from the adhesive by ethyl acetate is at least 800,000, the molecular weight distribution is 2.0˜7.0; and a polarizer and a liquid crystal display comprising the above composition show excellent durability under a high temperature and humidity condition, and can improve the light leakage phenomenon and provide excellent operability at the time of manufacturing polarizer by effectively providing high modulus and stress release property.

The invention discloses a method for preparing polypropylene with high melt strength, which comprises melt-blending polypropylene, monomer containing double bond, peroxide, dithiocarbamate series substance and antioxidant. The dithiocarbamate is added as adjuvant to inhibit the propylene degradation of the peroxide, improve the graft ratio, reduce monomer amount containing double bond, and save the cost. The obtained polypropylene with high melt strength has melt strength more than 2-15 times of that of raw material, and gel content smaller than 10%.

The invention belongs to the field of hydrogenation of acrylonitrile-butadiene rubber latex. The hydrogenation of acrylonitrile-butadiene rubber latex is realized through the technical scheme as follows: the mixture of acrylonitrile-butadiene rubber latex and hydrazine hydrate is heated to 30 to 70 DEG C, and then constant temperature is kept for 2 to 8 h, and in the process with constant temperature, aqueous solution of sodium periodate is dripped into the mixture, the dripping rate is controlled, and the dripping is accomplished within 2 to 6 hours. The method has the advantages of simple process flow, low cost, less pollution, high hydrogenation rate, low cross linking level of the prepared hydrogenated acrylonitrile-butadiene rubber latex, and good processing property.

The invention relates to a preparation method of a high-performance ultra-low-odor maleic anhydride grafted composition by reaction extrusion. The maleic anhydride grafted composition is characterized in that the composition comprises 90wt%-97wt% of polymeric resin, 1wt%-5wt% of maleic anhydride, 0.5wt%-2wt% of initiator, 0.5wt%-1.5wt% of second monomer, 0.5wt%-2wt% of odor absorbent and 0.1wt%-1wt% of antioxidant. The preparation method comprises the steps as follows: weighing the raw materials; mixing in a high speed mixer for 2-5 minutes; discharging; and carrying out fusion reaction and extruding in a twin-screw extruder at a rotation speed of 180-600rpm at 150-225 DEC C. The maleic anhydride grafted composition has the characteristics of high grafting ratio, light color, low gel content and low maleic anhydride residue, and can be widely applied in a high molecular material processing industry.

The invention discloses a preparation method of natural rubber with constant viscosity which relates to the technique of mooney viscosity control of natural rubber. The method comprises the steps of adding the mercaptan compounds into the natural rubber, mixing evenly, and then performing the conventional processes of solidification, tabletting, prilling and drying. The natural rubber with constant viscosity of the invention has the storage hardening value of smaller than 2 represented by the Wallace initial plasticity, and has the storage hardening value of smaller than 5 represented by the mooney viscosity, thereby significantly improving the processing characteristics.

The invention relates to an environment-friendly polyethylene compatilizer and a preparation method thereof. The environment-friendly polyethylene compatilizer comprises the following components in percentage by weight: 75 to 98 percent of polyethylene, 1 to 10 percent of functional monomer, 0.1 to 10 percent of initiator, 0.1 to 9 percent of anti-crosslinking agent, 0.1 to 3 percent of antioxidant and 0.1 to 3 percent of lubricating agent. The preparation method comprises the following steps of: placing the components in a highly mixing machine in a ratio; mixing; feeding the mixture into a double-screw extruder in a side feeding manner; extruding by using the double-screw extruder; and performing ultrasonic treatment to obtain the product. Compared with the prior art, the environment-friendly polyethylene compatilizer and the preparation method thereof have the advantages that: the polyethylene compatilizer with high grafting ratio is obtained by a compound initiating system and an ultrasonic technology; the problems of high monomer residual amount and serious gelling phenomenon are solved; emission of toxic substances is reduced; and the environment and healthiness of users are protected.

The invention discloses a high-strength heat-resistant modified silicon rubber power cable sheath material which is prepared from the following raw materials in parts by weight: silicone rubber, fluorine rubber, nano calcium carbonate, modified silica, potassium titanate whiskers, aluminum hydroxide, ferric oxide, tin oxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, methyltris(methylethylketoximino)silane, benzoyl peroxide, hydroxyl silicone oil, an amino silane coupling agent, dibutyltin dilaurate, magnesium oxide, a hydroxy stearic acid, an accelerant, an antiager, and a plasticizer. The high-strength heat-resistant modified silicon rubber power cable sheath material disclosed by the invention is high in strength and good in heat resistance, and a cable sheath prepared by using the high-strength heat-resistant modified silicon rubber power cable sheath material is good in comprehensive performance and long in service life.

The invention relates to a preparation method of an acrylonitrile copolymer spinning solution to mainly solve a problem of easy gel generation of solutions in the prior art. The preparation method comprises the following steps: 1, adding a solvent, acrylonitrile, itaconic acid and an initiator azo-bis-iso-heptonitrile to a reactor, and reacting at 30-45DEG C for 24-50h under the protection of a gas inert to the reacting substances to obtain an acrylonitrile copolymer spinning solution I; and 2, carrying out pressure reduction on the spinning solution I to remove residual monomers and bubbles to obtain the novel acrylonitrile copolymer spinning solution. The method well solves the problem through above technical scheme, and can be applied to the industrial production of carbon fiber precursors.

The invention relates to an emulsion polymerization method for preparing a tractable butadiene styrene rubber. The polymerization method comprises at least the following steps: adding part of styrene (an oil phase) and part of an emulsifier (an aqueous phase), a regulator and an initiator into a polymerization kettle; adding butadiene; carrying out emulsion polymerization with stirring; and when conversion rate of the polymerization reaction in the middle stage reaches 30-60%, refilling the emulsifier, the crosslinking agent, styrene and the regulator by one or more times. The styrene butadiene rubber prepared by the method provided by the invention has high micro gel content and low gel content; coupled with the electron cloud effect of the pi bonds in the benzene ring of the molecular chain, a three-dimensional net shape structure is easy to form in the processing process; and the rubber product has good physical and mechanical properties, increased Mooney viscosity, and correspondingly increased tensile strength and 300% stretching strength.

The present invention relates to a method for preparing monoolefine-conjugated diene copolymer solution for halogenating. The method comprises: (1) mixing a terminant solution which has been cooled tobe below 35 DEG C with monoolefine-conjugated diene copolymer slurry, wherein the terminator solution contains C1-C2 haloalkanes and saturated aliphatic alcohols A and optionally C5-C8 aliphatic alkanes, the saturated aliphatic alcohols A is one or several kinds of C1-C5 saturated mono fatty alcohol, one or several kinds of C2-C4 saturated dihydric fatty alcohol and one or several kinds of saturated fatty alcohols shown in the formula (1), (2) replacing the halogenated alkane in the solution by at least one replacement solvent and removing the unreacted monomer, wherein the replacement solvent is selected from C5-C8 aliphatic alkanes. The halogenating butyl rubber obtained by the method has the characteristic of low gel content, and the low molecular weight oligomer content in the halogenated butyl rubber having a weight average molecular weight of less than 20,000 is low.

The present invention provides a natural rubber obtained by drying collected natural rubber latex without coagulation, wherein the drying is performed using a drum dryer and/or a belt dryer. In addition, there is provided a method of forming a natural rubber-filler mixture by adding at least one of carbon black and an inorganic filler to natural rubber latex, and adding a compound containing acyl to these natural rubber and natural rubber-filler mixture. A natural rubber of a viscosity stabilizer of a hydrazine compound or an ester of an aromatic or aliphatic polycarboxylic acid derivative, and a rubber composition prepared using the above natural rubber and having excellent productivity, abrasion resistance and fracture resistance.

The invention provides a method for preparing nickel series low-mooney high cis-1,4-polybutadiene rubber. A solution polymerization reaction is performed by 1,3-butadiene in a polymerization solvent. The preparation method has the beneficial effect that a low-mooney cis rubber with the mooney viscosity between 25 and 40 can be prepared stably, and the prepared low-mooney cis rubber can be kept in a higher tensile strength, achieves the same strength as that of butadiene rubber with mooney viscosity between 40 and 50, and has a low gel content which is less than 0.5 percent.

The invention relates to a production method of high-nitrile SAN resin. The method comprises the specific steps of (a) mixing acrylonitrile with part of styrene cinnamene to obtain a mixture A, then mixing the mixture A with a circulating material and a condensation circulating material outside a reactor in a static mixer through a metering pump so as to obtain a mixture B, and then continuously leading the mixture B to the reactor; and enabling the rest of the styrene to be pumped into a steam condenser at the top of a reaction kettle through the metering pump, to be in contact with steaming air flows of the reactor, and to be mixed with condensation steam to become a condensation circulating material, and enabling the condensation circulating material to enter the reactor through a static mixer ; (c) polymerizing a reaction mixture at 140-160 DEG C in the reactor for 1.5-2.5 hours so as to obtain an SAN copolymer; and (d) performing two-stage devolatilization in a devolatilization machine, and performing pelleting in a pelletizer, so as to obtain the high-nitrile SAN resin with narrow distribution. According to the high-nitrile SAN resin produced by the method disclosed by the invention, the percentage by mass of acrylonitrile is greater than or equal to 32%, the melt indexes of products are smaller than 6g/10min(230 DEG C, 2.16Kg), and the yellow index of the products is smaller than 12.

The invention relates to a pre-mixing process in a process for producing rare-earth isoprene rubber through isoprene solution polymerization by using a rare-earth catalyst. The pre-mixing process is characterized by comprising the following steps of: pre-mixing the rare-earth catalyst, an isoprene monomer and a solvent in a pre-mixing device consisting of a pipeline high-speed mixer and a pre-mixing kettle (14), and then injecting the mixture into a polymerization kettle. Aiming at the problems of poor dispersion of the catalyst, the monomer and the solvent during the isoprene solution polymerization, the process realizes efficient pre-mixing reaction of the rare-earth isoprene rubber. The rare-earth isoprene rubber can be widely applied to tyres and other rubber products, can be mixed with other rubbers, is particularly suitable for food and medicament industries such as artificial respiratory organs and the like, and is more suitable on the sanitation aspect compared with natural rubber and titanium rubber.

The invention relates to a process for preparing carboxylic acrylonitrile butadiene rubber through an emulsion polymerization method. An emulsifier and an adjusting agent are added in batch, and a crosslinking agent and a pre-crosslinking agent titanate are added at different times, so the carboxylic acrylonitrile butadiene rubber has the characteristics of high content of a microgel, low content of a gel, controllable combined acid index, easy formation of a stereo netted structure in the processing process, uniform distribution of carboxylic groups on a molecular chain, uniform structure formed in the vulcanizing and product processing processes, slight stress relax phenomenon, and good dimension stability. The rubber obtained through adopting the method has good physical and mechanical properties and an improved Mooney viscosity, and has corresponding better compression set, Shore A hardness, tearing strength, tensile strength, elongation at break and 100% stress at definite elongation than common carboxylic rubber.

The invention is related to a process for producing modified polyethylene having decreased melt flow rate (5 kg, 190° C.) (MFR). In particular, the present invention is directed to a process in a controlled manner for producing modified polyethylene recyclates having low MFR and low gel content directly by reactive extrusion processing.

The invention relates to the field of rubber, particularly a method for preparing polyisoprene rubber latex. The method for preparing polyisoprene rubber latex comprises the following steps: (1) synthesizing an organic-solvent-containing polyisoprene rubber solution; (2) adding water, an emulsifier and a pH buffering agent, and emulsifying the obtained mixed solution under the action of mechanical force while controlling the pH value of the emulsion at 9-13, thereby obtaining a polyisoprene rubber emulsion; and (3) enabling the polyisoprene rubber emulsion to continuously pass through a concentrator and a scraper-bearing film evaporator, wherein the inside of the concentrator is provided with a static skimmer and/or a dynamic skimmer, the inside of the scraper-bearing film evaporator is provided with both a static skimmer and a dynamic skimmer, and in addition, at least part of the obtained polyisoprene rubber emulsion is circulated to the inlet of the film evaporator. The method can greatly enhance the latex preparation efficiency, and can obtain the polyisoprene rubber latex with stable performance.