36results about How to "High-NCO content" patented technology

Compositions incorporating water-curable urethane constituent(s) are formulated with favorable viscosity and viscosity stability characteristics, while at the same time, preserving desired hardness characteristics. The present invention is particularly useful in applications in which water-curable compositions include NCO-functional resins having relatively high NCO content and / or incorporate MDI-based constituents. Preferred modes of practicing the invention include implementing one or more formulation strategies to help retain hardness while preserving good viscosity characteristics. These preferred strategies involve (i) balancing scavenger, polyisocyanate and polyfunctional polyol content of the compositions or resins thereof, as the case may be, (ii) formulating an NCO-functional resin with chain extender constituent(s) to enhance viscosity stability, (iii) formulating with one or more plasticizers that enhance viscosity performance, and (iv) combinations of two or more of these strategies.

The invention belongs to the field of polyurethane curing agents and discloses a method of synthesizing a polyurethane curing agent by a multi-batch charging manner and a product thereof. The method includes following steps of: mixing a small molecule alcohol with single hydroxy and an isocyanate monomer, reacting at 20-60 DEG C for 1-2 h to obtain a polyurethane prepolymer, mixing a Mannich base catalyst and a polar solvent, stirring, heating to 30-100 DEG C, preheating for 20-40 min, dividing the polyurethane prepolymer into equal parts according to mass, adding the equal polyurethane prepolymer parts into a mixed solvent in batch, adding a polymerization inhibitor to terminate the reaction after the addition is finished, and adding a small molecule alcohol for modification to obtain the product that is the polyurethane curing agent. In the polyurethane curing agent, the solid content is 50+ / -2%, the NCO group content is 7.0-8.0%, and the percentage of free TDI is not more than 0.5%. The polyurethane curing agent has advantages of light color, narrow molecular weight distribution and capability of rapidly curing at room temperature.

The invention discloses a method for preparing a polyurethane-modified organosilicon double-component room-curing elastomer adhesive, which comprises the following steps: (1) uniformly mixing hydroxypropyl-terminated silicone oil and glycerol, and dehydrating to obtain a hydroxyl-terminated (-OH) component; (2) reacting aromatic polyisocyanate, the hydroxyl-terminated (-OH) component and dibutyltin dilaurate to obtain a component A; (3) adding vapor-phase silica white, carbon black and talcum powder into the container filled with hydroxy silicone oil and dihydroxy polysiloxane, adding a catalyst, adding 3-aminopropyl triethoxy silane, finally adding a defoaming agent, uniformly mixing, and drying to obtain a component B; and (4) uniformly mixing the component A and component B in a mass ratio of 12:(23.5-24), and curing at room temperature for 4-5 hours. The elastomer adhesive prepared by the method has the advantages of favorable tear resistance, excellent high / low temperature resistance and excellent binding property. The preparation method is easy to operate and accessible in raw materials, and lowers the preparation cost.

The invention discloses zero-VOC radiation curable / moisture curing resin and a preparation method thereof. The zero-VOC radiation curable / moisture curing resin comprises the following raw materials, in parts by weight: 15-25 parts of a polyol, 18-24 parts of a polyacid and a derivative of the polyacid, 30-40 parts of a monoacid, 4-7 parts of a carboxyl-containing olefin, 0.3-1 part of epoxy resin,10-20 parts of isocyanate, 0.1-0.5 part of a first catalyst, 0.1-0.3 part of a polymerization inhibitor, 0.01-0.1 part of a second catalyst, and 0.005-0.015 part of a third catalyst. The product provided by the invention has low viscosity, strong adhesion, no solvent and no volatile organic compound emission, and is green and environmentally friendly; and the preparation method is simple and easyto implement, the preparation costs are low, no three wastes (waste water, waste gas and solid waste) are generated in the synthetic process, and the industrialized production is easy to realize.

The invention discloses a high solid content and economical tannic acid resistant two-component white environment-friendly waterborne primer. The preparation method includes: adding a dispersant intodeionized water and performing dispersion, then adding a PH regulator, then adding a defoamer and conducting high speed dispersion, then adding solid powder and performing high speed dispersion; adding a water-based hydroxyl acrylic emulsion and a waterborne polyurethane polyol dispersion into another new material preparation pot, and adding a mixture of a neutralizer and deionized water at an intermediate speed to obtain an emulsion; adding a defoamer and a wetting leveling agent into the emulsion and performing high speed dispersion so as to obtain a mixed solution c for standby use; addinga prepared white pulp into the mixed solution c, then adding deionized water and a rheological assistant to obtain a component A; mixing water dispersed isocyanate and a cosolvent evenly to obtain a component B; and mixing the component A and the component B evenly in a proportion of 10:1, thus obtaining the environment-friendly waterborne primer. The waterborne primer prepared according to the invention has the advantages of low cost, good environmental protection effect, good stability and strong practicability.

The invention discloses a preparation method of polyurethane prepolymer with low free isocyanate monomer. The preparation method comprises the following steps of: forming into mixed alcohol by trihydric alcohol and dihydric alcohol under the temperature of 120-150DEG C, and carrying out vacuum dehydration; putting isocyanate monomer and ester solvents into a reactor to keep the temperature at 30-70DEG C, and dropwise adding the mixed alcohol into the reactor; after dropwise adding, continuously reacting for 3-6h under the temperature of 40-70DEG C under stirring, and discharging in a cooling way to obtain polyurethane prepolymer; and separating the obtained polyurethane prepolymer, and adjusting the solid content of polyurethane prepolymer solid and the content of free isocyanate monomer in the separated heavy components by diluted solvent. According to the preparation method, the real continuous production can be realized, all the recovered solvent and isocyanate monomer can be recycled, the zero emission can be realized, and the real clean production can be realized; and the product has the characteristics of being low in viscosity, high and adjustable in NCO value content, low in the content of the free isocyanate monomer, high in solid content, good in compatibility, etc.

The invention discloses a preparation method of a polyurethane adhesive. The preparation method comprises the following steps: (1) adding polyester polyol into a reaction kettle, and carrying out vacuum dehydration for 4-6 hours; (2) adding isocyanate, a combined solvent, a catalyst and a cross-linking agent into the reaction kettle of the step (1), heating to 80-90 DEG C, and reacting for 2-4 hours; (3) dissolving nano-nickel powder into the combined solvent, adding the combined solvent into the reaction kettle of the step (2), and uniformly mixing; and (4) carrying out vacuum distillation on substances in the reaction kettle of the step (3) at 80-90 DEG C, cooling, and discharging, so as to obtain the polyurethane adhesive. The polyurethane adhesive prepared by virtue of the preparation method is good in conductivity and high in peel strength.

The invention discloses a polyurethane firming agent with low free MDI monomers and a method for preparing the same. The invention solves the problems that the prior art has complex MDI polyurethane firming agent preparation process and high equipment investment. The technical proposal comprises the following steps that: the step one, a molecular weight modifying agent is added into a compositionof MDI and polylol; prepolymerization reaction is carried out in a solvent, wherein, the equivalent proportion of NCO to OH is 3-5 to 1; and the adding amount of the molecular weight modifying agent is 1 to 1.5 percent of the MDI mass; step two, after the prepolymerization reaction is finished, a trimeric catalyzer is added into the solvent for trimerization reaction; the adding amount of the trimeric catalyzer is 0.1 to 0.3 percent of the residual MDI mass theoretically after the reaction in the step one; after the trimerization reaction is finished, a polymerization inhibitor is added into the solvent to terminate the reaction. The process method has low production cost and simple process equipment; the prepared firming agent has stable storage, low toxicity and performances which can meet various requirements of the firming agent of sizing agent for packing a composite membrane; when the solid content is 75 percent, the content of free MDI monomers is less than 2 percent of the firming agent mass.

The invention discloses a polyurethane prepolymer and a preparation method thereof. The isocyanate group content MNCO in the polyurethane prepolymer is 4-10%, and the viscosity at 25 DEG C is 1,000-4,000mPa.s. The storage duration of the polyurethane prepolymer at room temperature is not shorter than 3 days; and the polyurethane prepolymer has the advantages of low viscosity, high NCO content, high stability and long storage duration, is used for preparing non-solvent polyurethane and can improve the performance of the non-solvent polyurethane material.

The invention relates to a polyurethane material for preparing a chicken manure scraper of a farm. The invention is characterized in that: the scraper comprises a support portion and a wedge portion,the height of the wedge portion is greater than the height of the support portion to form a flange, the angle formed by an oblique side of the wedge portion and a bottom side of the support portion is20 to 40 degrees, the oblique side of the wedge portion is perpendicular to an upper side of the support portion, the flange has an angle of 50 to 70 degrees and is rounded; the support portion and the wedge portion are integrally molded; the scraper material is polyurethane; and the scraper material is made of the following parts by weight of raw materials: PTMG is added with TDI, so that the -NCO content in a synthesized prepolymer is 6.8%, and the prepolymer is added to MOCA. The invention has the beneficial effects that the angle of the wedge portion is arranged to fit a conveyor belt, the scraping of the manure is realized, and the polyurethane material has large frictional force to avoid slipping and rusting in the water environment.

The invention discloses a method for preparing a polyurethane-modified organosilicon double-component room-curing elastomer adhesive, which comprises the following steps: (1) uniformly mixing hydroxypropyl-terminated silicone oil and glycerol, and dehydrating to obtain a hydroxyl-terminated (-OH) component; (2) reacting aromatic polyisocyanate, the hydroxyl-terminated (-OH) component and dibutyltin dilaurate to obtain a component A; (3) adding vapor-phase silica white, carbon black and talcum powder into the container filled with hydroxy silicone oil and dihydroxy polysiloxane, adding a catalyst, adding 3-aminopropyl triethoxy silane, finally adding a defoaming agent, uniformly mixing, and drying to obtain a component B; and (4) uniformly mixing the component A and component B in a mass ratio of 12:(23.5-24), and curing at room temperature for 4-5 hours. The elastomer adhesive prepared by the method has the advantages of favorable tear resistance, excellent high / low temperature resistance and excellent binding property. The preparation method is easy to operate and accessible in raw materials, and lowers the preparation cost.

The preparation process of low free toluene diisocyanate as curing agent includes the following steps: reaction between toluene diisocyanate and polyol in the NCO / OH molar ratio 2-3 at 50-80 deg.c with reaction medium SO2, gamma-butrrolactone, dimethhyl sulfoxide, dimethyl carboxy diacid ester; adding polyisocyanate polymerizing catalyst when the content of NCO is 15-16 % for further reaction and adding polyisocyanate polymerizing inhibitor when the content of NCO is 14-15%; adding fatty hydrocarbon and / or cyclic fatty hydrocarbon as extracting agent for multiple extraction, eliminating the extracting agent through letting stand or distillation; and diluting and discharging pre-polymer. The present invention can prepare curing agent with low chroma, low visosity and high NCO content and no toluene diisocyanate monomer and other toxic matter.

The invention belongs to the technical field of chemistry and particularly discloses low-viscosity liquefaction modified MDI (4,4'-diphenylmethane diisocyanate) and a preparation method thereof. The liquefaction modified MDI has the viscosity of 310-380 mPa.s and the NCO content of 18%-21%. The method comprises the steps as follows: a) MDI is added to a reactor provided with temperature control, stirring and reflux condensation devices to be heated under the protection condition of inert gas, and the temperature is kept at 50-55 DEG C until MDI is molten into a liquid; b) the temperature is increased to 78-98 DEG C, a catalyst A and mono-hydroxyl small-molecular alcohol are added, the mixture reacts completely, then, the temperature is decreased to 60-75 DEG C, and macromolecular polyols are added; c) a stabilizer B is added, the experiment is ended after 0.5-2 h, and the temperature is decreased to the room temperature. The method is low in raw material cost, simple in process and easy to control in process condition when used for synthesizing the low-viscosity liquefaction modified MDI. The low-viscosity liquefaction modified MDI has high reaction activity and good storage stability and can be used for preparing room-temperature casting polyurethane elastomers, coatings, adhesives and sealants.

The invention provides a highly water-resistant and hydrophilic polyisocyanate curing agent and its preparation method and application. The polyisocyanate curing agent has the following structural formula: the polyisocyanate curing agent has a higher NCO content, lower viscosity and excellent water resistance; it is prepared with acrylic dispersions of different hydroxyl values, and the appearance of the paint film, Water resistance and other performance tests show that the polyisocyanate curing agent not only maintains the high-gloss and high-transparency appearance characteristics of water-based curing agents, but also has water resistance and other properties comparable to solvent-based curing agents, and is especially suitable for the field of metal anti-corrosion.

The invention relates to a preparation method of an external cross-linking agent for waterborne polyurethane. The preparation method comprises the following steps: by using imidazole ionic liquid modified hydroxyl-terminated polyether and polyisocyanate as raw materials, carrying out addition polymerization reaction under the action of a catalyst to finally obtain the external cross-linking agentfor waterborne polyurethane. The external cross-linking agent for waterborne polyurethane has nonionic and ionic hydrophilic groups and good water solubility, the water resistance, solvent resistanceand mechanical strength of a PU adhesive film can be remarkably improved, and a cross-linked coating is not sticky.

The invention relates to a matte super-hard weatherproof finishing material, which is composed of a component A and a component B. The component A comprises a polyurethane prepolymer, ethyl acetate, dibutyltin dilaurate, BYK-052, BYK-306, 600-mesh cobalt oxide and silicon dioxide; and the component B comprises hydroxyl-containing silicone resin and acrylic resin. The finishing material is sprayedon a constructed floor to improve yellowing and slippery floor materials to enable the floor material to have mechanical properties such as slip resistance, mildew proof, seepage prevention, weather resistance, and super-hardness based on pencil hardness. The finishing material is widely used in concrete-based, polyurethane-based, epoxy-based and other floors.