Polyurethane composition for high-surface-quality self-demolding automobile exterior trimming part material and application thereof

Abstract

The invention discloses a polyurethane composition for a high-surface-quality self-demolding automobile exterior trimming part material and application thereof. The polyurethane composition comprises, in percentage by weight, a component A which comprises 50-60% of polyether polyol 1, 10-20% of polyether polyol 2, 5-10% of polyether polyol 3, 1-5% of a fluorosilicone modified amino compound, 5-10% of a chain extender, 0.2-2% of a foam stabilizer, 0.5-2% of a catalyst, 1-5% of a flame retardant and 0.2-1% of water. 0.5-3% of other additives are selectively added; the polyether polyol 1 takes cane sugar and glycerol as a mixed initiator, the hydroxyl value is 400-500mg KOH/g, and the polyether polyol 1 has six functional groups; the polyether polyol 2 takes glycerol as an initiator, the hydroxyl value is 400-500mg KOH/g, and the polyether polyol 2 has three functional groups; the polyether polyol 3 takes glycerol as an initiator, is grafted by epoxypropane and terminated by ethylene oxide, has a hydroxyl value of 33-37 mg KOH/g, and has three functional groups; and a component B is PAPI.

Description

technical field [0001] The invention relates to the field of polyurethane, in particular to a polyurethane composition for automotive exterior trim materials. Background technique [0002] Glass fiber reinforced polyurethane composites have been widely used in automotive interior and exterior trims due to their excellent physical properties such as light weight, high mechanical strength, and good weather resistance. [0003] Automotive exterior parts mainly refer to front and rear bumpers, air intake grilles, wheel covers, spoilers, logos, door handles, fenders, etc., which are connected to the body by bolts, buckles or double-sided adhesive strips. The production process of exterior parts is divided into two types. One is to pre-set the skin in the mold, and then use the long glass fiber reinforced polyurethane process to prepare. The skin is usually made of ABS board, PP or PVC. However, this process exists There are two problems. The first problem is that the existence o...

AI Technical Summary

Problems solved by technology

The production process of exterior parts is divided into two types. One is to pre-set the skin in the mold, and then use the long glass fiber reinforced polyurethane process to prepare. The skin is usually made of ABS board, PP or PVC. However, this process exists There are two problems. The first problem is that the existence of the skin is not conducive to the discharge of gas during the foaming process of polyurethane, resulting in cavitation between the material and the skin, so that the surface will be packaged during later outdoor use; the second problem is that due to the The thermal expansion coefficient of the polyurethane material and the skin is different, and the product will deform at high temperature

The second process is to directly use glass fiber reinforced polyurethane composite materials for foam molding without pre-setting the skin. Although this process avoids the shortcomings of the first process to a certain extent, and the process is simple, it also has problems. Because the polyurethane material is a good adhesive, a large amount of external mold release agent needs to be sprayed on each mold during the production process to achieve a better mold release effect. Usually, the external mold release agent is sprayed before the resin enters the mold. Coated on the surface of the mold, although it can have a good demoulding effect, the process is cumbersome and has a negative impact on the environment, and the commonly used wax or water-based external mold release agent sprays the mold, which will produce a waxy layer on the mold Or scale will cause pinholes or cracks on the surface of the product, which will affect the surface quality of the product, cause certain stress defects in the material, and reduce the mechanical properties of the material

Since the reactive base of the alkyl phosphate series release agent cannot fully react during the preparation process, the final release agent product is acidic, which greatly limits the use of basic fillers and pigments in use, and will Generate water, resulting in bubbles, cracks and other defects in the product

[0006] Patent document CN105199071A discloses a polyurethane composite material, a method for preparing a polyurethane composite material and the use of the obtained product. The internal release agent used is selected from alkylamides and / or alkylimides, preferably oleic acid amide , erucamide, oleic acid palmitic acid amide and erucic acid palmitic acid amide, one or two or more, this type of internal mold release agent is a solid particle, although this patent uses polyether polyols containing amino groups to solubilize , but the surface quality of the obtained product is poor, and there are many pinholes on the surface, which affects the appearance of the product and the mechanical properties of the product

[0007] Patent document CN107735421A discloses a rigid polyurethane resin composition, rigid polyurethane resin, moldings and fiber-reinforced plastics. The internal release agent used is selected from stearates or fatty acid esters, and stearates belong to The solid powder substance has the problem of uneven dispersion in the polyurethane resin combination, which causes defects on the product surface, and fatty acid esters are used as internal release agents, and the release effect is general

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