A kind of high surface quality polyurethane composition for self-demolding automobile exterior trim material and its application

Abstract

The invention discloses a high-surface-quality polyurethane composition for self-demolding automotive exterior trim materials and its application. It includes component A in terms of weight percentage: 50-60% polyether polyol 1, 10-20% polyether Polyol 2, 5-10% polyether polyol 3, 1-5% fluorosilicon modified amino compound, 5-10% chain extender, 0.2-2% foam stabilizer, 0.5-2% catalyst, 1~ 5% flame retardant, 0.2-1% water, optionally add 0.5-3% other additives; polyether polyol 1 is mixed with sucrose and glycerin as starter, hydroxyl value is 400-500mg KOH / g, 6-official ; Polyether polyol 2 uses glycerin as the initiator, the hydroxyl value is 400~500mg KOH / g, 3-official; Polyether polyol 3 uses glycerin as the initiator, grafted with propylene oxide, and capped with ethylene oxide , hydroxyl value 33~37 mg KOH / g, 3 official; B component is PAPI.

Description

Technical field [0001] The present invention relates to the field of polyurethane, specifically to polyurethane compositions for automotive exterior materials. Background [0002] Glass fiber reinforced polyurethane composite materials 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 trim mainly refers to the front and rear bumpers, intake grilles, wheel covers, spoilers, logos, door handles, fenders and other parts connected to the body by bolts, snaps or double-sided adhesive strips. The production process of exterior trim is divided into two kinds, one is the pre-placed epidermis in the mold, and then the long glass fiber reinforced polyurethane process is used for preparation, usually the skin used is ABS plate, PP or PVC and other materials, but there are two problems in this process, the problem is that due to the...

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

Images