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

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; (2) coupling graphene oxide with a silane coupling agent so as to obtain processed graphene oxide, adding processed graphene oxide and a combined solvent into the reaction kettle of the step (1), and carrying out ultrasonic treatment for 2-8 hours; (3) adding isocyanate, a catalyst and a chain extender into the reaction kettle of the step (2), heating to 80-90 DEG C, and reacting for 2-7 hours; 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 high in heat conductivity coefficient and peel strength.

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.

Increased health, safety, and environmental awareness motivated the development of new and improved water curing technology for formulating, manufacturing, and using water curable compositions (also referred to in the art as water induced urethanes). The present invention is based, at least in part, upon the concept of formulating NCO functional resins used in water curable compositions from one or more polyisocyanate constituents that comprise at least one sterically hindered isomer of diphenyl methane diisocyanate (MDI). These isomers have a combination of exceptionally low vapor pressure and suitable moisture reactivity that lead to numerous advantages. Due to their low volatility, these isomers may be substituted for all or a portion of the TDI content of a conventional water induced urethane formulation. Particularly preferred embodiments eliminate any TDI, have 100% solids, are solvent free, and are characterized by essentially zero VOC emissions with respect to isocyanate. The compositions are substantially more environmentally friendly than conventional formulations.

A process for the preparation of polyisocyanates which contain one or more biuret groups, by reacting

• a) an aliphatic or cycloaliphatic isocyanate containing two or more isocyanate groups (isocyanate a) with
• b) a tertiary alcohol or a mixture of water and a tertiary alcohol (biuretizing agent b)

at from 100 to 250° C., which comprises carrying out the reaction in the presence

c) of a stabilizer (c) which constitutes a catalytic amount of urea, ammonia, biuret, a urea derivative of the formula I

in which R¹, R², R³ and R⁴ are hydrogen, C₁ to C₁₀ alkyl or C₅ to C₁₀ aryl, or

a carboxamide of the formula II

in which R⁵ is C₁ to C₁₂ alkyl which is unsubstituted or in which 1, 2 or 3 hydrogen atoms are replaced by a radical

The invention relates to the technical field of curing agents, specifically to an ionic waterborne curing agent based on bio-based pentamethylene diisocyanate and a preparation method thereof. The preparation method for the ionic waterborne curing agent based on the bio-based pentamethylene diisocyanate provided by the invention comprises the following steps: mixing an impurity-removed bio-based pentamethylene diisocyanate trimer, a sulfamic acid substance and organic amine, then carrying out heating to 60 DEG C to 110 DEG C under the protection of nitrogen, carrying out a reaction for 3 to 7hours, and when a product is transparent, carrying out cooling to 25 DEG C to 40 DEG C. The preparation method provided by the invention has the following advantages: the process of synthesis is simple; the flow of operation is easy to be mastered; the raw material namely the bio-based pentamethylene diisocyanate trimer has a clean source and is free of pollution to the environment; and through addition of a small amount of sulfonate and the organic amine, the ionic waterborne curing agent with a solid content of 100%, an NCO content of up to 22.3%, low viscosity and rapid curing rate can be obtained.

The invention provides an environment-friendly high urea linkage fast curing single component polyurea material. The environment-friendly high urea linkage fast curing single component polyurea material is prepared from the following components in parts: 80-140 parts of blocked isocyanate prepolymer, 5.5-7 parts of a polyurea liquid filler, 30-40 parts of amine-terminated polyether, 5-10 parts ofa terminated amino chain extender, 4-6 parts of a solid filler and 1-2 parts of an auxiliary agent. According to the environment-friendly high urea linkage fast curing single component polyurea material, the polyurea liquid filler can improve the urea linkage content of a system, and the solvent-free solid content is 100%, thereby ensuring high durability used in water environment. The environment-friendly high urea linkage fast curing single component polyurea material has good mechanical properties, environmental protection is achieved, hydrolysis resistance is achieved, and the material canbe thick coated into a film at a time, cured fast, and is suitable for quick repair needs of water conservancy projects, and the like. In addition, the environment-friendly high urea linkage fast curing single component polyurea material has a simple preparation method and is suitable for industrial production.

The invention discloses an enclosed type polyurethane curing agent emulsion and a preparation method and applications thereof. The enclosed type polyurethane curing agent emulsion is prepared by the following steps: (a) preparing polyisocyanate prepolymer containing a sulfonic acid group; (b) preparing enclosed type polyisocyanate prepolymer; and (c) preparing enclosed type polyurethane curing agent emulsion. The invention also discloses applications of the enclosed type polyurethane curing agent emulsion. The enclosed type polyurethane curing agent emulsion exists in a form of aqueous emulsion and can be individually stored for a long term. The emulsion does not contain any organic solvent, has a high solid content and a high NCO content, can be directly diluted by adding water, and can be stored for a long term after being mixed with aqueous resin containing active hydrogen. The prepared aqueous baking finish and aqueous high temperature glue are convenient to use; and the prepared products have a good waterproof property and high strength.

The invention provides a urea formaldehyde resin-coated isocyanate microcapsule and belongs to the field of microcapsule composite material preparation. The urea formaldehyde resin-coated isocyanate microcapsule is prepared from 29 to 53% by weight of water, 1.85 to 17.02% by weight of formaldehyde, 2 to 27% by weight of urea, 0.1 to 2% by weight of an emulsifier, 0.2 to 6% by weight of a system stabilizer, 17 to 32% by weight of isocyanate, 2 to 6% by weight of an isocyanate protecting agent, 0.05 to 3% by weight of an acidic pH adjuster and 0.05 to 3% by weight of an alkaline pH adjusting agent. The urea formaldehyde resin-coated isocyanate microcapsule utilizes urea formaldehyde resin as a capsule coating isocyanate so that liquid isocyanate forms a solid state. The method prevents isocyanate volatilization, masks odor of isocyanate and prolongs an isocyanate use time. The urea formaldehyde resin-coated isocyanate microcapsule has high activity and controllable particle sizes and is easy to transport and store.

The invention relates to ultraviolet/moisture dual-cured resin as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) preparation of a prepolymer A, namely, adding a catalyst and a polymerization inhibitor to catalyze acrylic ester compounds and beta-ketone ester to perform Michael addition reaction; (2) preparation of a prepolymer B, namely, heating polyester glycol to 70 to 90 DEG C, adding a catalyst and fat diisocyanate, and stirring and reacting for 2 to 3 hours; (3) preparation of the ultraviolet/moisture dual-cured resin, namely, mixing the prepolymer A and the prepolymer B, adding a catalyst, stirring, heating to 80 to 90 DEG C, reacting until the NCO content in a mixed liquid is 8 to 13 percent, adding the polymerization inhibitor, and discharging to obtain the ultraviolet/moisture dual-cured resin. The ultraviolet/moisture dual-cured resin prepared with the preparation method is high in curing speed, high in solid content and high in NCO content; a prepared paint film has the excellent compressive performance, such as resistance to chemicals, adhesion force and high temperature resistance.

The invention discloses a solvent-free waterborne polyisocyanate curing agent and a preparation method and application thereof. The solvent-free waterborne polyisocyanate curing agent is polyisocyanate prepolymer containing sulfonic acid groups. The preparation method includes: dissolving dicarboxyl sulfonate into an organic solvent, allowing the solution to have reaction with polyisocyanate prepolymer, and distilling to remove the organic solvent to obtain the solvent-free waterborne polyisocyanate curing agent. The solvent-free waterborne polyisocyanate curing agent is truly free of VOC discharge, excellent in water dispersity and storage stability, high in NCO content, low in viscosity, capable of being coordinated with various resin containing hydroxyl, carboxyl or amino to prepare double-component polyurethane coating and double-component polyurethane adhesive, and capable of allowing a product to be good in water resistance and high in strength.

The invention provides a silane hybrid quaternary ammonium salt modified polyisocyanate curing agent and a preparation method thereof. The preparation method includes the steps that by mass, 1.0-3.0%of alkylol amine, 2.0-4.0% of silane coupling agent and 90-94% of polyisocyanate react under the protection of the nitrogen atmosphere at the temperature of 40-60 DEG C till the NCO content of the system reaches a theoretical value, 0.05-0.5% of polymerization inhibitor is added, and thus a silane hybrid polyisocyanate curing agent containing tertiary amine is prepared; and then 2.0-4.0% of sultone is added to react with the silane hybrid polyisocyanate curing agent containing tertiary amine until the sultone is completely consumed, and cooling and discharging are conducted. By adopting the sultone hydrophilic modifier with strong hydrophilicity, the prepared curing agent can be dispersed in water, is low in viscosity and environment-friendly, and has the characteristics of excellent scratch resistance, transparency, storage stability and the like.

The invention relates to a two-component polyurethane coating with low emission of volatile organic compounds (VOC). The polyurethane coating is prepared from a component A, a component B and a component C, wherein the weight ratio of the component A to the component B to the component C is equal to 1 to (2 to 3) to (0.5 to 1); the component A is prepared from 10-30 parts of a diisocyanate prepolymer and 70-90 parts of diphenylmethane diisocyanate; the component B is prepared from 50-80 parts of short-oil alkyd resin, 5-25 parts of an organic solvent, 0-0.5 part of a dispersing agent, 0-5 parts of extinction powder, 0-1.0 part of wax powder, 0-15 parts of talcum powder, 0-3.0 parts of an anti-settling agent, 0-0.5 part of a leveling agent, 0.1-0.5 part of a defoaming agent and 0.1-0.3 partof a drying catalyst; the component C is prepared from 70-90 parts of butyl acetate and 10-30 parts of propylene glycol methyl ether acetate. The two-component polyurethane coating provided by the invention is prepared from the high solid content raw materials, so that the consumption of the solvent is effectively reduced; the VOC emission of the polyurethane coating is about 400g/L, so that thepolyurethane coating is especially suitable for being applied and popularized to finishing and painting of wood furniture.

The invention relates to a hydrophilic polyurethane polymer and a preparation method thereof, and is characterized in that the hydrophilic polyurethane polymer is prepared from the following components by mass: 2-5 parts of a hydrophilic modifier composition, 95-98 parts of polyisocyanate, and 0.5-1 part of a neutralizer. The hydrophilic modifier composition comprises polyether sulfonic acid and sulfamic acid, and the polyether sulfonic acid and the sulfamic acid are prepared according to the molar ratio of 1: 0.8-1: 6. The preparation method of the hydrophilic modifier composition comprises the following steps: adding amino polyether into excessive sultone, reacting at room temperature for 4-8 hours to generate polyether type sulfonic acid, adding alkyl tertiary amine into a reaction system, reacting at room temperature for 4-8 hours to generate sulfamic acid, and dissolving the sulfamic acid in the polyether type sulfonic acid; and continuously heating to 60-100 DEG C, and reacting for 4-8 hours. The invention has the advantages of good water dispersion performance, wide application range and the like.