阅读说明：本技术 一种喷涂用改性聚丙烯复合材料及其制备方法 (modified polypropylene composite material for spraying and preparation method thereof ) 是由 张申伟 周海 闫溥 蒋文远 于 2019-09-03 设计创作，主要内容包括：本发明公开了一种喷涂用改性聚丙烯复合材料及其制备方法,由以下组分按重量份制备而成：聚丙烯50～75份,增韧剂15～20份,无机填料20～25份,多孔二氧化硅2～3份,高碳链乙氧基酰胺蜡1～3份,抗氧剂0.2～0.3份,润滑剂0.2～0.3份。本发明利用高碳链乙氧基酰胺蜡的强极性对聚丙烯复合材料进行表面修饰,显著提高了材料的表面极性和表面张力,实现了材料的免火焰处理喷涂,使得油漆易于在复合材料表面涂覆。并借助多孔二氧化硅的多微孔结构使油漆在涂覆过程中更容易渗透进入复合材料表面,固化后的油漆树脂与复合材料基体保持较强的粘结强度,可满足汽车外饰喷涂材料的长周期使用要求。(The invention discloses a modified polypropylene composite material for spraying and a preparation method thereof, wherein the modified polypropylene composite material is prepared from the following components in parts by weight: 50-75 parts of polypropylene, 15-20 parts of a toughening agent, 20-25 parts of an inorganic filler, 2-3 parts of porous silicon dioxide, 1-3 parts of high-carbon-chain ethoxy amide wax, 0.2-0.3 part of an antioxidant and 0.2-0.3 part of a lubricant. According to the invention, the strong polarity of the high-carbon chain ethoxy amide wax is utilized to perform surface modification on the polypropylene composite material, so that the surface polarity and surface tension of the material are obviously improved, the flame-free treatment spraying of the material is realized, and the paint is easy to coat on the surface of the composite material. And the paint is easier to permeate into the surface of the composite material in the coating process by virtue of the microporous structure of the porous silicon dioxide, and the cured paint resin and the matrix of the composite material keep stronger bonding strength, so that the long-period use requirement of the automobile exterior spraying material can be met.)

1. The modified polypropylene composite material for spraying is characterized in that: the composition is prepared from the following components in parts by weight:

2. The modified polypropylene composite for spray coating according to claim 1, wherein: the polypropylene is a mixture of homopolymerized polypropylene and copolymerized polypropylene, and the melt index of the polypropylene under the condition of 230 ℃/2.16kg is 0.5-60 g/10 min.

3. The modified polypropylene composite for spray coating according to claim 1, wherein: the toughening agent is at least one of ethylene-octene copolymer, ethylene-butene copolymer, ethylene propylene diene monomer, propylene-alpha olefin copolymer, polybutadiene, styrene-butadiene-styrene block copolymer and hydrogenated styrene-butadiene block copolymer.

4. the modified polypropylene composite for spray coating according to claim 1, wherein: the inorganic filler is at least one of talcum powder, mica, crystal whisker, wollastonite, glass fiber and calcium carbonate.

5. the modified polypropylene composite for spray coating according to claim 1, wherein: the particle size of the porous silicon dioxide is 3-5 mu m, and the average pore diameter is 8.8 nm.

6. The modified polypropylene composite for spray coating according to claim 1, wherein: the antioxidant is at least one of hindered phenol antioxidant and alcohol ester antioxidant.

7. The modified polypropylene composite for spray coating according to claim 1, wherein: the lubricant is at least one of calcium stearate, zinc stearate and stearate.

8. The preparation method of the modified polypropylene composite material for spraying as claimed in any one of claims 1 to 7, characterized by comprising the following steps:

(1) Uniformly stirring and mixing polypropylene, a toughening agent, an inorganic filler, porous silicon dioxide, high-carbon-chain ethoxy amide wax, an antioxidant and a lubricant at a high speed according to a ratio, controlling the temperature of a stirring kettle at 85-90 ℃, uniformly stirring and mixing, and cooling to room temperature to obtain a mixture;

(2) And putting the mixture into a double-screw extruder, and melting, extruding, air-drying and granulating to obtain the modified polypropylene composite material for spraying.

9. The method of claim 8, wherein: in the step (2), the extrusion temperature of each extrusion interval in the double-screw extruder is 60 +/-10 ℃, 70 +/-10 ℃, 120 +/-10 ℃, 180 +/-10 ℃, 200 +/-10 ℃, 210 +/-10 ℃ and 210 +/-10 ℃ in sequence, and the rotation speed of the screw is 400-450 r/min.

10. The method of claim 8, wherein: the surface tension of the modified polypropylene composite material for spraying is 45-52 mN/m.

Technical Field

The invention belongs to the field of automobile materials, and particularly relates to a modified polypropylene composite material for spraying and a preparation method thereof.

Background

the safety, low oil consumption and aesthetics of automobiles become important indexes for evaluating the comprehensive cost performance of the automobiles for consumers at present, and are always hot spots for attention and research of the automobile and material industries. The requirements of the automobile exterior trimming parts on safety and size assembly can be met by modifying the polypropylene resin, and the polypropylene composite material is required to be painted for the parts with requirements on aesthetic degree, so that the aesthetic property of the exterior trimming parts is improved. Therefore, after the polypropylene composite material is molded, the requirement of size assembly is required to be met, and the composite material and paint have excellent adhesive force and can meet the long-term use of automobile exterior trimming parts. However, polypropylene is a non-polar material, the surface energy is low, most of paint is unsaturated polyester and epoxy resin, the surface energy is large, and if the polypropylene is directly coated with a polypropylene composite material, the polypropylene material is not easy to infiltrate, bond and coat, and the adhesive force is poor.

At present, methods for improving the paint adhesion of polypropylene composite materials mainly comprise oxidizing the surfaces of the composite materials by flame, corona and plasma methods, so as to improve surface active groups and surface energy, so that the paint is easy to be hydrophilic and coated on the polypropylene composite materials, wherein the flame treatment method is one of the more efficient processes before the coating of the existing automobile exterior materials. Before the polypropylene composite material is sprayed, the flame treatment can be used for remarkably improving the surface polarity of the polypropylene composite material and is helpful for coating paint, but the flame treatment method can increase the surface oxidability of the composite material, reduce the long-term thermal aging performance of the composite material and also play a destructive role in firm adhesion of the paint on the surface. In patent CN102070833A, the filling master batch modified by the high-polarity additive is blended with the polypropylene composite material, so that the surface polarity of the modified polypropylene composite material is improved, and the composite material has good paint adhesion. Patent CN105367906A discloses that by introducing vinyl acetate copolymer into polypropylene composite material, the surface polarity of the composite material is improved, and flameless treatment spraying of vehicle parts is realized. The polar polymer resin is introduced into the polypropylene composite material, so that the surface polarity of the composite material can be improved, the surface tension of the composite material is expanded, and the improvement of the adhesive force of the composite material and the paint is really an efficient and convenient way. Therefore, the polar modifier is used for improving the surface polarity of the polypropylene composite material for spraying, flame-free treatment spraying is realized, the polypropylene composite material is required to have high surface polarity, and the bonding strength of the composite material and a paint resin interface is also particularly important for meeting the long-term use of exterior trimming parts.

Disclosure of Invention

The invention aims to provide a modified polypropylene composite material for spraying and a preparation method thereof, which are used for solving the problems in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

the modified polypropylene composite material for spraying is prepared from the following components in parts by weight:

In a further scheme, the polypropylene is a mixture of homo-polypropylene and co-polypropylene, and the melt index of the polypropylene under the condition of 230 ℃/2.16kg is 0.5-60 g/10 min.

In a further aspect, the toughening agent is at least one of an ethylene-octene copolymer, an ethylene-butene copolymer, an ethylene-propylene-diene monomer, a propylene-alpha olefin copolymer, polybutadiene, a styrene-butadiene-styrene block copolymer, and a hydrogenated styrene-butadiene block copolymer.

In a further scheme, the inorganic filler is at least one of talcum powder, mica, whisker, wollastonite, glass fiber and calcium carbonate.

In a further scheme, the particle size of the porous silicon dioxide is 3-5 μm, and the average pore diameter is 8.8 nm.

In a further scheme, the antioxidant is at least one of hindered phenol antioxidants and alcohol ester antioxidants.

in a further scheme, the lubricant is at least one of calcium stearate, zinc stearate and stearate.

The invention also aims to provide a preparation method of the modified polypropylene composite material for spraying, which comprises the following steps:

(1) Uniformly stirring and mixing polypropylene, a toughening agent, an inorganic filler, porous silicon dioxide, high-carbon-chain ethoxy amide wax, an antioxidant and a lubricant at a high speed according to a ratio, controlling the temperature of a stirring kettle at 85-90 ℃, uniformly stirring and mixing, and cooling to room temperature to obtain a mixture;

(2) And putting the mixture into a double-screw extruder, and melting, extruding, air-drying and granulating to obtain the modified polypropylene composite material for spraying.

Further, in the step (2), the extrusion temperature of each extrusion interval in the double-screw extruder is 60 +/-10 ℃, 70 +/-10 ℃, 120 +/-10 ℃, 180 +/-10 ℃, 200 +/-10 ℃, 210 +/-10 ℃ and the rotation speed of the screw is 400-450 r/min.

In a further scheme, the surface tension of the modified polypropylene composite material for spraying is 45-52 mN/m.

Compared with the prior art, the invention has the beneficial effects that:

1. According to the invention, the high-polarity surface treating agent high-carbon chain ethoxy amide wax is introduced into the polypropylene composite material, the molecular chain of the high-carbon chain ethoxy amide wax comprises oleophylic and hydrophilic groups, the oleophylic group has good compatibility with the polypropylene composite material, and the hydrophilic group amide group has strong polarity, so that the paint is easy to coat on the surface of the polypropylene composite material; the surface modification is carried out on the polypropylene composite material by using the high-carbon chain ethoxy amide wax, so that the surface polarity of the polypropylene composite material can be obviously improved, the surface tension of the composite material is enhanced, the flame-free treatment spraying of the paint is realized, and the paint is easy to coat on the surface of the composite material.

2. The paint is easier to permeate into the surface of the composite material in the coating process of the polypropylene material by virtue of the microporous structure of the porous silicon dioxide, and the cured paint resin and the matrix of the composite material keep stronger bonding strength, so that the long-term use requirement of the automobile exterior spraying material can be met.

3. The method carries out surface modification on the polypropylene composite material, can save the flame treatment link for direct spraying after the material is formed, optimizes the paint spraying process and reduces the production cost.

Detailed Description

The present invention will be further described with reference to the following examples. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

It should be noted that in the following examples, the polypropylene is formed by mixing homo-polypropylene and co-polypropylene, wherein the homo-polypropylene is homo-polypropylene SZ30S from Korean (Wuhan) petrochemical company Limited, and the co-polypropylene is co-polypropylene SP179 from Qilu petrochemical company of China; the high carbon chain ethoxy amide wax is sold under the trade name KF-027, and the manufacturer is Kjiang Kyowa refining Co., Ltd. Other materials in the examples are conventional chemical products in the art and are commercially available.