Preparation method of polyurethane prepolymer with low free isocyanate monomer

A polyurethane prepolymer and isocyanate technology, applied in the field of polyurethane prepolymer, can solve the problems of inability to prepare prepolymers with low free isocyanate monomers, inability to separate isocyanate monomers, and inability to obtain prepolymer products, and achieve NCO Adjustable and controllable content, high NCO content, adjustable and controllable NCO group content

CN102659997AActive Publication Date: 2012-09-12SOUTH CHINA UNIV OF TECH +1

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Patent Information

Authority / Receiving Office: CN · China
Patent Type: Applications(China)
Current Assignee / Owner: SOUTH CHINA UNIV OF TECH
Publication Date: 2012-09-12

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Abstract

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.

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Description

technical field

[0001] The invention relates to a polyurethane prepolymer, in particular to a preparation method of a polyurethane prepolymer with low free isocyanate monomer. Background technique

[0002] Polyurethane is an important product and material used in many industries such as building materials, furniture, coatings, plastics, leather and adhesives. The performance of polyurethane is related to the quality and safety of hundreds of billions of products such as wooden furniture, toys, automobiles, leather, shoes and composite films. The coating film of polyurethane coating has the advantages of high hardness, good toughness, strong chemical resistance and fast drying. It is one of the most widely used solvent-based coatings with excellent performance. Polyurethane coating is composed of two components, one component is alkyd resin, polyester resin and acrylic resin and other hydroxyl substances, and the other key component is polyurethane prepolymer formed by preli...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

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