171results about How to "Low residual monomer content" patented technology

The present invention provides a production process to obtain a hydrophilic polymer, having a low residual monomer content, with good productivity while keeping the properties of a hydrogel polymer resultant from polymerization. In a drying process for a hydrogel polymer, the hydrogel polymer is dried under normal pressure at a material temperature of not higher than 90° C. until the water content of the hydrogel polymer reduces to 15~40 weight %, and then the hydrogel polymer is kept for not shorter than 10 minutes either in a state where the change of the water content of the hydrogel polymer is within 5 weight % and where the material temperature is in the range of 70~120° C. or in a state where the water content of the hydrogel polymer is in the range of 15~40 weight % and where the material temperature is in the range of 70~120° C., and then the hydrogel polymer is finish-dried.

The invention provides a thermal expansibility microsphere and a method for reducing residual monomers therein. The method comprises a re-initiation step of supplementing an initiating agent of the residual monomers in a process of preparing the thermal expansibility microsphere by using a suspension polymerization method, wherein the initiating agent of the residual monomers is an oxidation reduction initiator system. The preparation method of the thermal expansibility microsphere, provided by the invention comprises the following steps: preparation of a water phase, preparation of an oil phase, suspension polymerization and residual monomer reduction. The technical scheme provided by the invention realizes quick reduction of the residual monomers under a low-temperature condition, is simple in production process, low in consumption and short in processing time, and simultaneously can efficiently reduce the content of the residual monomers in the thermal expansibility microsphere and a suspension reaction medium. The thermal expansibility microsphere prepared by using the method contains a little number of residual monomers and is small in pollution.

The invention relates to a process for the production of uretdione polyisocyanates with improved storage stability and their use as a starting component for polyurethane plastics, in particular as a crosslinker component for the production of two-component polyurethane coating compositions.

Preparation of SAP is carried out by taking acrylic acid as monomer, taking ion film base as neutralizer, heating to initial temperature, adding into cross-linking agent and oxidation reducing evocating agent, aqueous solution polymerizing, drying, crushing, screening and surface cross-linking treating. It has fast reactive speed and high normal saline absorptive rate. It can be used for sanitary products and continuous production.

Polymers having amine-thiol terminal moieties are provided. The amine-thiol terminal moieties are imparted by using amine-thiols as chain transfer agents in aqueous addition polymerizations.The polymers are useful as mineral dispersants, as water-treatment additives for boiler waters, cooling towers, reverse osmosis applications, sugar refining, paper production, geothermal processes and oil wells, and as detergent additives acting as builders, anti-filming agents, dispersants, sequestering agents and encrustation inhibitors.

Adhesives and pressure-sensitive adhesives comprising polymerization products of acrylates, the adhesives being meltable and comprising polymerization products of esters of (meth)acrylic acid and (meth)acrylic acid, the polymerization product having a molecular weight Mn of greater than 50 000 g/mol and Mw of greater than 500 000 g/mol.

The present invention relates to a process for preparing radiation-curing binders containing allophanate groups by reacting at temperatures of ≦130° C. A) one or more compounds containing uretdione groups with B) one or more OH-functional compounds which contain groups which react, with polymerization, with ethylenically unsaturated compounds on exposure to actinic radiation (radiation-curing groups), C) optionally NCO-reactive compounds other than B), in the presence of D) a catalyst containing at least one zinc compound, to form allophanate groups by opening the uretdione ring. The present invention also relates to the binders obtained by the process of the invention and to coating compositions containing these binders.

The invention discloses a low-odor spray-coating-free PC/ABS (polycarbonate/acrylonitrile butadiene styrene) material and a preparation method thereof. The material is prepared from the following ingredients including 40 to 80phr of PC, 20 to 60phr of ABS, 5 to 10phr of AS, 0 to 1phr of lubricating agents, 1 to 1.5phr of deodorants, 0.5 to 1phr of heat stabilizers, 0.5 to 1phr of color masterbatch, 0 to 10phr of compatibilizers, 0 to 5phr of processing auxiliary agents, 0.1 to 0.5phr of antioxidants and 0 to 5phr of ultraviolet light absorbers. The material has the low odor and spray-coating-free appearance requirements; the odor grade is lower than or equal to 3.0; the appearance luster is good; the blackness is high; the thermal stability is high; the defects of flowing marks, melting and connecting wires, silver silks and the like cannot be easily generated; the spraying work procedure is omitted; the good spray-coating-free effect is achieved; through the creative selection on raw materials and auxiliary agents and the process innovation, a low-odor spray-coating-free PC/ABS material is produced, and is obviously superior to similar products in the market.

The present invention discloses preparation process of polyammonium dimethyldiallyl chloride. By using the water solution of industrial cation monomer DMDAAC as material, and through once adding persulfate as initiator and Na4EDTA as complexing agent, controlling reaction temperature under stirring, stepped temperature raising for controlling the reaction rate, initiating the polymerization of DMDAAC monomer at relatively low temperature for high polymerization degree and high molecular weight, adding small amount of water solution of initiator in the late stage to raise the monomer converting rate and controlling the diluting water amount to regulate solid content in the product, polyammonium dimethyldiallyl chloride with relatively high molecular weight is prepared. The process has high economic performance, good industrial foundation, mild reaction condition, low production cost and other advantages, and the product has various uses.

The invention discloses fast-dissolving cationic polyacrylamide and a preparation method thereof. The method comprises the following steps: mixing a polyacrylamide solution, a cationic monomer solution, a weakly polar monomer, deionized water, disodium ethylenediamine tetraacetate, polyethylene oxide and urea to prepare a solution A; adding a photoinitiator into a chain transfer agent, performinguniform dissolution under stirring to prepare a solution B; uniformly mixing the solution A and the solution B under stirring to obtain a reaction solution; and adjusting the pH of the reaction solution to 3-6, introducing nitrogen for deoxygenation, performing irradiation under a short-wave ultraviolet lamp, performing irradiation under a long-wave ultraviolet lamp, cutting the prepared rubber block, performing granulation, performing drying, and performing crushing to obtain the fast-dissolving cationic polyacrylamide. The method provided by the invention greatly shortens the dissolution time of the cationic polyacrylamide, improves the use efficiency of the cationic polyacrylamide in industries such as water treatment, sludge dewatering, mineral dressing by washing, oil and gas extraction and papermaking, and has huge potential application value.

The invention relates to a preparation method of a narrow-distribution polyacrylonitrile-based carbon fiber spinning solution. The preparation method of the narrow-distribution polyacrylonitrile-basedcarbon fiber spinning solution mainly solves the problems of wide molecular weight distribution of polyacrylonitrile, high residual monomer content and long polymerization reaction time in the priorart. The preparation method of the narrow-distribution polyacrylonitrile-based carbon fiber spinning solution includes the following steps that (1) polymerization raw material acrylonitrile, a comonomer 1 and/or a comonomer 2, a solvent and an initiator are added into a reactor, a thermostatic reaction is started under the protection of inert gas to the reaction materials, and a reaction temperature is controlled to 60-65 DEG C; (2) when the conversion rate exceeds T1, the temperature is increased by 5-10 DEG C; (3) when the conversion rate exceeds T2, the temperature is increased by 5-10 DEGC; and (4) when the conversion rate reaches T3, the reaction is finished, and preparation of the spinning solution is completed. According to the technical scheme, the problems of wide molecular weight distribution of polyacrylonitrile, high residual monomer content and long polymerization reaction time are well solved, and the preparation method can be used in the industrial production of the polyacrylonitrile-based carbon fiber spinning solution.

The invention relates to the technical field of paint for interior decoration, in particular to a water-based two-component coating for rail transit vehicle interiors and a preparation method thereof.The coating comprises a component A and a component B in a weight ratio of 10: 1, wherein the component A comprises water-based hydroxyl acrylic resin, water-based hydroxyl polyurethane hand feelingresin, a water-based hydroxyl organic silicon hand feeling auxiliary agent, pigment and filler, an environment-friendly flame retardant, sand streak wax, extinction powder, a water-based dispersing agent, a water-based wetting agent, a water-based defoamer, a water-based leveling agent, a water-based thickener and water, and the component B comprises water-based polyisocyanate resin and a solvent.The preparation method comprises preparation of the component A and preparation of the component B. The coating provided by the invention adopts a two-component cross-linking curing technology and ismatched with a water-based hydroxyl organic silicon hand feeling auxiliary agent, so that the hand feeling of the coating can be kept stable for a long time, the VOC content and the residual monomeramount are low, formaldehyde, benzene series and the like are not contained, and the coating is suitable for human body contact and is very suitable for interior coating of rail transit vehicles.

The invention discloses a production method of acrylic polymer resin. The production method includes the steps of forming bulky hydrogel of acrylic polymer, granulating and drying. The production method is characterized in that by weight of the bulky hydrogel of acrylic polymer, 6-7% of initiator solution is added to obtain gel granules 15-25mm in diameter; the drying step includes two drying stages, drying in the first stage is at 50-110 DEG C for the duration of 5-20 minutes, and drying the second stage is at 110-180 DEG C for the duration of 10-30 minutes. The invention further discloses products produced by the production method and applications thereof.

The present invention relates to a process for preparing polyamides, comprising a hydrolytic polymerization and at least two extraction steps which are not in immediate succession.

The present invention discloses a structure-oriented composite initiator system and an acrylamide polymer and a preparation method and application thereof. The structure-oriented composite initiator system contains a redox system initiator, the redox system initiator comprises oxidizing and reducing agents, wherein the structure-oriented composite initiator system further comprises a polyamide-amine dendritic macromolecule. The acrylamide polymer has a higher molecular weight, higher shear resistance, better anti-aging properties, and good water-soluble and other advantages, and the acrylamide polymer has high apparent viscosity in high temperature and high salinity water, and can be used as a high temperature and high salinity oil reservoir tertiary oil recovery oil displacement agent.

The invention provides an acrylamide copolymer, as well as a preparation method and an application thereof. The copolymer comprises a structural unit A, a structural unit B and a structural unit C, wherein the structural unit A is a unit having a structure as shown in a formula (1), the structural unit B is at least one unit having a structure as shown in formulae from (2) to (5), and the structural unit C is a unit having a structure as shown in a formula (6); the mass ratio of the structural unit A to structural unit B to structural unit C is 1:(0.001-3):(0.001-0.5); and the viscosity-average molecular weight of the acrylamide copolymer is 30-35 millions. A temperature-endurance salt-resistance product of the acrylamide copolymer has the characteristic of high molecular weight; and the acrylamide copolymer has an advantage of greatly thickening, and can be used as an oil-displacing agent for tertiary recovery of a high temperature and high salinity reservoir.