90results about How to "Low polymer content" patented technology

A hydrogel polymer obtained by polymerizing a monomer component including acrylic acid (salt) is post-neutralized so that each of polymer particles derived from a polymer produced by neutralizing the hydrogel polymer has an allowable neutralization ratio. The polymer as obtained by neutralizing the hydrogel polymer is reacted with a crosslinking agent reactive to a functional group of the polymer. The allowable neutralization ratio, for example, is a neutralization ratio which is not lower, by not less than 20 mole percent, or more than, at least 55 mole percent, than an average neutralization ratio of a mass of the polymer particles, and the post-neutralization is carried out so that a number of polymer particles having a non-allowable neutralization ratio outside the allowable neutralization range is not more than 10 in 200 polymer particles, thus obtaining a water-absorbent agent having high absorbency under no applied pressure and high pressure wherein the amount of water soluble component is lower compared with the conventional water-absorbent agent and a change in pH of a swollen gel is small.

The present invention discloses a substantially amorphous pharmaceutical composition comprising a drug that can exist in a variety of polymorphic forms and a pH sensitive polymer, which inhibits the crystallization of the drug during formulation and reconstitution. Polymers of higher molecular weight are more effective at lower loading, especially when the drug polymer matrix is prepared by the solvent evaporation or solvent extraction technique. The compositions used as dry syrups maintain bioavailability of the drug and effectively mask the taste of the drug when the composition is reconstituted.

The present invention relates to a macromonomer having a polydimethylsiloxane backbone that has a mol % dimethyl siloxanes, b mol % siloxanes substituted with -K-RIM, c mol % siloxanes substituted with -K-RIM-Z and d mol % siloxanes substituted with -L-Z, and in which the terminal siloxane groups are tri-substituted with R, wherein RIM is a refractive index modifying group; Z is a free radically polymerisable group; K is a spacer group; L is optional and is a spacer group; each R is independently selected from an RIM, a lower alkyl group, hydrogen or Z; and a is a molar percentage of the macromonomer which is in the range of from 0 to 95 mol %; b is a molar percentage of the macromonomer which is in the range of from 5 to 99 mol %; c is a molar percentage of the macromonomer which is in the range of from 0 to 2 mol %; and d is a molar percentage of the macromonomer which is in the range of from 0 to 2 mol %; with the proviso that c and d are not both 0 mol %.

The invention provides a preparation method of acrylate polymer/nanometer silicon dioxide composite particles for polycarbonate toughening. According to the method, acrylate polymer emulsion is prepared by selecting emulsifier dosage and nanometer silicon dioxide dosage, utilizing a seeded emulsion polymerization technology, performing preparation of a seed stage elastomer, increase of elastomer particle size and in-situ coating of a plastic outer layer and adjusting an initiator adding mode, then nanometer silicon dioxide pre-emulsion and the acrylate polymer emulsion are mixed evenly, and the acrylate polymer/nanometer silicon dioxide composite particles are obtained through emulsion breaking. A little amount of the composite particles is added into polycarbonate, the toughness of a polycarbonate substrate material can be remarkably improved by adding the acrylate polymer/nanometer silicon dioxide composite particles 1.96%, low-temperature notch impact strength of the composite material is improved by 287% compared with purer polycarbonate, the breaking elongation rate is improved by 298%, and meanwhile the tensile strength is improved by 157%.

The invention relates to a catalyst component for ethene polymerization and a catalyst, and use of the catalyst. The catalyst component comprises a superfine inorganic oxide carrier, the carrier is loaded with a reaction product of a magnesium halide, a halogenated alcohol, at least a titanium halide and at least an electron donor compound, and the catalyst component is obtained by the reaction including the following steps: (1) mother liquor preparation, to be more specific, reacting the magnesium halide, the titanium halide and the halogenated alcohol with the general formula of XnROH in the electron donor compound to prepare mother liquor; (2) carrier mixing, to be more specific, mixing the mother liquor prepared by the step (1) with the superfine inorganic oxide carrier to obtain slurry; and (3) spray forming, to be more specific, performing spray drying on the slurry obtained by the step (2) to obtain the solid catalyst component. The prepared catalyst has high activity when the catalyst is used for ethylene homopolymerization or copolymerization of ethene and other alpha olefins, and the obtained polymers are low in hexane extract, and low in oligomer content.

The invention provides a high-viscosity polyamide 56 resin, a high-strength polyamide 56 industrial yarn, and a preparation method and application thereof. The preparation method of the high-strengthpolyamide 56 industrial yarn comprises the following steps of heating and melting high-viscosity polyamide 56 resin by adopting a single-screw or double-screw extruder, drawing in a spinning box to obtain a primary yarn, and then carrying out heat preservation, cooling, oiling, pre-interlacing, multi-stage stretching, tension setting, relaxation setting, main interlacing and winding on the primaryyarn to obtain the high-strength polyamide 56 industrial yarn. The high-strength polyamide 56 industrial yarn provided by the invention has good mechanical properties and heat and humidity resistance, and can be applied to the fields of sewing threads, tire cords, airbag yarns, release cloth, water cloth, canvas, safety belts, ropes, fishing nets, industrial filter cloth, conveyor belts, parachutes, tents and bags.

The invention relates to the field of nylon materials, and discloses a method for preparing polyester-nylon composite fibers by melt direct spinning. The method comprises the following steps of 1) burdening, specifically, heating and mixing caprolactam, an end-capping reagent, water and a catalyst to obtain a mixture; 2) ring opening; 3) pre-polycondensation, specifically, carrying out a pre-polycondensation reaction and devolatilization; 4) final polycondensation, specifically, carrying out a final polycondensation reaction and devolatilization; 5) devolatilizing before spinning; and 6) spinning, specifically, directly conveying nylon melt and polyester melt which are devolatilized before spinning to a composite spinning assembly, performing extruding, cooling, oiling, stretching and winding to obtain the polyester-nylon composite fibers. By means of the method, direct spinning after nylon melt polymerization can be achieved, slices do not need to be prepared in advance, and the content of hot water extractables and cyclic dimers in the nylon melt can be effectively controlled; and composite spinning is carried out on the nylon melt and the polyester melt to obtain the polyester-nylon composite fibers in different composite forms.

The invention discloses a macromolecular polymerization inhibitor containing phenolic groups and nitroxide groups, and a preparation method thereof. The polymethyl acrylate with polymerization degree of p, the phenolic compound and the nitroxide free radical type compound are dissolved in the solvent according to the mol ratio of 1:x:y, the catalyst with mass being 0.5-3.0wt percent of the total mass of the reaction mixture is added in to react at the temperature of 20-80 DEG C and under the 0.05-0.09MPa until the concentration of the phenolic compound and the nitroxide free radical type compound is not changed, the reaction mixture subsides in water, and the polyacrylate main chain is obtained after the sediment is dried and is connected with the macromolecular polymerization inhibitor containing the phenolic groups and the nitroxide free radical groups through ester linkage; and the method has the advantages that the raw material is easily obtained, the operation is simple and the method is convenient for the industrial production. The prepared product can effectively prevent the acrylate from being polymerized in the production process, reduce the content of the low polymer in the product, reduce the consumption of the total polymerization inhibitor and improve the product quality and has the broad industrial application prospect.

The invention belongs to the technical field of medicines, and concretely relates to a cefathiamidine compound. The cefathiamidine compound is a cefathiamidine hydrate, the structure of the cefathiamidine compound is represented by formula (I), and the X-ray powder diffraction pattern of the cefathiamidine compound is represented by figure 1. The cefathiamidine compound is a novel crystal form compound of the cefathiamidine hydrate, and is different from cefathiamidine compounds reported in the prior art. A result of tests shows that the new crystal form compound of the cefathiamidne hydrate has lower content of high-molecular polymers than cefathiamidine in the prior art, and the content of the high-molecular polymers does not obviously increase with the prolongation of the storage time; and the compound has substantial antibiosis activity on Staphylococcus aureus, coagulase negative staphylococci and Enterococcus faecalis.

The invention discloses a continuous preparation method of semi-aromatic polyamide with low oligomer content, which comprises the following steps: (a) by using water as a solvent and diamine and binary as initial feeding materials, adding a catalyst, pulping, heating to dissolve, neutralizing and salifying; (b) dehydrating and concentrating the salt solution obtained after neutralizing and salifying, detecting the content of diamine in the steam condensate, adjusting the molar ratio of amine to acid to be greater than 1.0, and then carrying out a prepolymerization reaction; and (c) sequentially carrying out flash evaporation spraying and circulating air drying containing extraction agent steam on the pre-polymerization reaction liquid, melting and tackifying by an extruder, and carrying out underwater pelletizing to obtain semi-aromatic polyamide particles with low oligomer content. The extractant vapor is selected from dichloromethane and/or trichloromethane vapor. The preparation method disclosed by the invention is simple in process and short in production period; and the content of oligomers in the semi-aromatic polyamide product is remarkably reduced and is lower than 0.85%, the molecular weight distribution is narrow, no pollution is caused to a mold during molding processing, and the semi-aromatic polyamide product can be widely applied to the fields of electronics, electrics, automobiles and the like.

The invention discloses a pretreatment method for rectifying and recovering dimethyl formamide (DMF) waste liquid of polyurethane (PU) synthetic leather. The pretreatment method comprises the following steps: (1) pumping the DMF waste liquid from a waste water storage tank of a PU synthetic leather production line into a coarse filter consisting of a stainless steel filter screen by using an infusion pump and performing first-stage separation to obtain coarse filtration DMF waste liquid; and (2) allowing the coarse filtration DMF waste liquid obtained by first-stage separation to enter a microfiltration hollow fiber membrane separation device and performing second-stage separation to obtain a DMF fine solution for rectification and recovery. By the pretreatment method for rectifying and recovering the DMF waste liquid of the PU synthetic leather provided by the invention, the problems of high pollution and high energy consumption of rectification and recovery of the DMF waste liquid in the PU synthetic leather industry are solved; the aims of energy saving and emission reduction in the production process of the PU synthetic leather are fulfilled, and economic benefit, social benefit and environmental benefit are organically unified.

The invention relates to the field of nylon materials, and discloses a devolatilization method of a nylon 6 melt. The method comprises the following steps: 1) introducing nylon 6 melt and water-containing hot nitrogen into a front-end devolatilization reaction kettle, carrying out devolatilization, conveying the devolatilized nylon 6 melt into a rear-end devolatilization reaction kettle, and carrying out secondary devolatilization; 2) feeding a gaseous mixture into a high-boiling-point component removal tower, condensing the high-boiling-point components in the gaseous mixture, and then discharging; and 3) feeding the remaining gaseous mixture into a low-boiling-point component removal tower, carrying out spraying, fractionation and condensation on the gaseous mixture in a rising process,discharging the low-boiling-point components, and discharging the remaining gas after vacuum treatment. According to the invention, efficient devolatilization can be carried out on nylon 6 melt, and the condensation polymerization reaction of the nylon 6 can be inhibited in the devolatilization process, so that the influence on the spinning forming process due to the violence of the molecular weight of the nylon 6 under the vacuum condition is avoided, time is provided for nylon 6 amide exchange, the molecular weight distribution is narrowed, and the melt quality is improved.

The invention provides a high-viscosity polyamide 56 resin, a high-strength polyamide 56 industrial yarn, and preparation methods and applications of the high-viscosity polyamide 56 resin and the high-strength polyamide 56 industrial yarn. The preparation method of the high-strength polyamide 56 industrial yarn comprises the following steps: heating and melting high-viscosity polyamide 56 resin byadopting a single-screw or double-screw extruder, drawing in a spinning box to obtain a primary yarn, and then carrying out heat preservation, cooling, oiling, pre-interlacing, multi-stage stretching, tension setting, relaxation setting, main interlacing and winding on the primary yarn to obtain the high-strength polyamide 56 industrial yarn. The high-strength polyamide 56 industrial yarn provided by the invention has good mechanical properties and heat and humidity resistance, and can be applied to the fields of sewing threads, tire cords, airbag yarns, release cloth, water cloth, canvas, safety belts, ropes, fishing nets, industrial filter cloth, conveyor belts, parachutes, tents and bags.

The invention relates to a preparation method of a high-performance ultrafiltration membrane, which comprises the following steps: (1) adding a certain amount of a membrane-forming polymer into a certain amount of a solvent, fully dissolving the membrane-forming polymer at 25-70 DEG C to obtain a membrane casting solution, and adding a pore-foaming agent into the membrane casting solution and fully dissolving the pore-foaming agent; dispersing nano foaming particles in a solvent, ultrasonically dispersing for 10-30 minutes, adding the nano foaming particles into the membrane casting solution, continuing to stir at 25-70 DEG C to form a uniform solution, and performing vacuum defoaming at 25-70 DEG C for 24 hours; (2) coating the surface of a supporting membrane with the membrane casting solution to form a liquid membrane with a certain thickness, and naturally evaporating the liquid membrane in an air atmosphere for 10-60 seconds; (3) immediately putting the liquid membrane into an acidic aqueous solution coagulating bath, carrying out phase conversion to form a membrane, and completing phase conversion to form the membrane after 1-5 minutes, so as to obtain an ultrafiltration membrane; and (4) putting the obtained ultrafiltration membrane into distilled water or glycerol for preservation.