Modified polyurethane composition with heat resistance

Abstract

The invention discloses a modified polyurethane composition with heat resistance, which consists of polyether diol based on bisphenol compound, a polyol component, and a polyisocyanate component, wherein the structural formula of polyether diol based on the bisphenol compound is shown in the description, wherein R1 is an alkylidene group or sulfonyl group with one to five carbon atoms; R2 and R3 are respectively an alkylidene group with two to four carbon atoms; and n1 and n2 are respectively an integer chosen from 1 to 5. The modified polyurethane composition with heat resistance provided bythe invention has excellent mechanical property, meets the requirement of pultrusion process operation on reactiveness, and the modified polyurethane composition with heat resistance has high enough glass transition temperature (i.e. heat resistance); and therefore the modified polyurethane composition with heat resistance can meet the requirement of applying weather-resistant powdery paint or baking finish, thus having a broad application prospect and a good market potential.

Description

technical field [0001] The invention belongs to the technical field of polyurethane composite materials, and in particular relates to a heat-resistant modified polyurethane composition. Background technique [0002] Pultrusion is a highly productive and highly automated method of manufacturing fiber-reinforced plastic profiles of fixed cross-sectional shape; typically, its raw materials consist of liquid resins (unsaturated polyester, vinyl ester, epoxy or polyurethane resins) and reinforcements (glass fibers, carbon fibers, natural fibers, etc.). [0003] Pultrusion molding technology usually uses a continuous traction device to draw continuous reinforcement materials to a resin impregnation tank or injection box to fully infiltrate the fibers with the resin, and then the resin-impregnated fibers are hardened and formed by heating the mold, and finally cut by the cutting device The desired profile length. [0004] For polyurethane that gels quickly at room temperature, th...

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Problems solved by technology

[0008] At present, polyurethane pultrusion composites are widely used in various structural profiles because of their good mechanical properties and high-efficiency production speed. However, for outdoor applications, aromatic polyurethane Problems such as yellowing, polymer degradation, and exposed fibers will affect the surface quality and mechanical properties of the material. Therefore, it is necessary to apply weather-resistant coatings on the surface of polyurethane composite materials to meet outdoor applications (such as: window frames, cable racks, tower poles, etc.) etc.) required weather resistance

[0009] Weather-resistant powder coatings and baking varnishes can provide excellent weather resistance for substrates. However, compared with room temperature curing coatings, they have relatively high processing and curing temperatures (higher than 120 ° C), and the processing and curing temperatures are higher than Generally, the glass transition temperature of the polyether polyol, aromatic polyisocyanate, and polyurethane resin system is used. Therefore, if the weather-resistant powder coating or baking varnish coating is directly applied to the composite material of the polyurethane system, it may cause deformation of the material and affect its performance.

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