CN109705517B - Preparation method of micro-foaming ABS material and high-surface-quality light injection molding material - Google Patents

Abstract

The invention relates to the technical field of ABS plastic modification, in particular to a preparation method of a micro-foaming ABS material and a high-surface-quality light injection molding material. The micro-foaming ABS composite material comprises the following raw materials in parts by weight: 70-99 parts of an ABS terpolymer; 0.5-5 parts of a compatilizer; 0.1-6 parts of special pigment; 0.1-5 parts of micro-foaming master batch; 0.1-10 parts of micro-foaming auxiliary agent; 0.05-2 parts of a dispersant; 0.05-1 part of antioxidant; 0.05-1 part of light stability. The micro-foaming ABS material with metal texture prepared by the invention can effectively prevent the generation of silver marks and gas marks on the surface of a product in the micro-foaming injection molding process, provides about 10-20% weight reduction effect and metal texture for the product, can overcome the defects of complex spraying or electroplating process flow, high pollution and high cost, is suitable for the use of product materials in the industries of automobiles and household appliances, and has important practical application value.

Description

Preparation method of micro-foaming ABS material and high-surface-quality light injection molding material

Technical Field

The invention relates to the technical field of modification of ABS materials, in particular to a preparation method of a micro-foaming ABS material and a high-surface-quality light injection molding material.

Background

ABS materials used for spraying are widely applied to the fields of manufacturing industry and chemical production, and especially in some appearance products in the household appliance industry and the automobile industry, excellent appearance effects such as metal, flicker, pearl texture and the like can be realized through spraying or electroplating. However, the traditional processes such as spraying, electroplating and the like have the following problems: 1. the pollution to the environment is serious; 2. the product can not be recycled and can not be used for the second time; 3. the process is complicated, the yield is low, and the production cost is high. On the other hand, the light weight of the product is a new direction for the development of the automobile and household appliance industries, and a new scheme for reducing the cost can be provided for customers.

As a light-weight technical means, the micro-foaming process not only can shorten the processing period, but also can reduce the weight of a product by forming a sandwich structure on the section of the product and has a good sound insulation effect. The spraying-free and micro-foaming technology is successfully combined and applied to the industries of automobiles and household appliances, and has great significance. However, the appearance problems of silver streaks, gas marks and the like generated by micro-foaming in the injection molding process are technical difficulties to be broken through urgently.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides a micro-foaming ABS material which comprises the following raw materials in parts by weight:

the micro-foaming auxiliary agent is polytetrafluoroethylene powder.

In the technical solution, further, the micro-foaming master batch is a master batch containing 20% of an AC foaming agent;

furthermore, the master batch takes ABS as a base material and contains polyethylene wax, an antioxidant and a foam core forming agent (such as talcum powder).

In the technical scheme, the compatilizer is further commercially available under the name of KH-550 and also known as gamma-aminopropyltriethoxysilane.

In the technical solution, further, the special pigment is silver element type aluminum powder with a particle size of 14 μm. The silver element type aluminum powder is added to present metal texture to the product, so that the material realizes the texture of spraying-free; in addition, the particle size of 14 μm can be limited to make the material have a smooth texture.

In the technical solution of the above, further, the dispersant is ethylene bis stearamide. The dispersing agent is used for uniformly dispersing the silver element type aluminum powder and the micro-foaming auxiliary agent in the matrix material, and simultaneously, the dispersing agent also has the function of a lubricating agent.

In the above technical solution, the antioxidant is an antioxidant 1010 (also known as tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] pentaerythritol ester).

In the technical scheme, the light stabilizer is 2- [ 2-hydroxy-3, 5-bis (1, 1-dimethylpropylphenyl) ] -2H-benzotriazole.

The invention also provides a preparation method of the high-surface-quality light injection molding material, which specifically adopts the micro-foaming ABS material, and comprises the following steps:

a, preparing a micro-foaming ABS material, namely weighing ABS, a compatilizer, a special pigment, a micro-foaming auxiliary agent, a dispersant, an antioxidant and a light stabilizer according to the weight percentage, and then adding the weighed materials into a high-speed stirrer to be uniformly mixed at a high speed to obtain a premix; extruding the premix in a double-screw extruder and granulating to obtain a micro-foaming ABS material;

b, putting 96% of the micro-foaming ABS material obtained in the step a and 4% of foaming agent master batch into a high-speed mixer for mixing to obtain a uniform mixture;

c, adding the uniform mixture obtained in the step b into an injection molding machine, and performing injection molding to obtain a high-surface-quality light injection molding material; wherein the temperature of the charging barrel of the injection molding machine is set to be 220-280 ℃, the injection pressure is 60-100MPa, and the injection speed is 70-90 mm/s.

In the technical scheme, furthermore, in the step a, the temperature of the double-screw extruder barrel is 180 ℃ and 240 ℃, and the screw rotating speed is 500 r/min.

The inventor finds that when the foaming master batch is added into the ABS material, a chemical foaming agent in the foaming master batch can be decomposed into gas in the injection molding process, the gas can flow in a mold along with an ABS melt, the ABS melt generates a large friction force with the surface of a mold cavity of the mold under high speed and high pressure, the gas in the middle of the melt is continuously turned to the surface of the mold cavity, and thus, the gas mark or silver line-shaped appearance defect is formed on the surface of a product. The invention provides a micro-foaming ABS material with metal texture by deeply analyzing the problem, firstly proposes that polytetrafluoroethylene is used as a micro-foaming auxiliary agent, controls the corresponding proportion, and takes low-molecular polyethylene wax as a dispersing agent and a lubricating agent of foaming master batches to have a synergistic effect with polytetrafluoroethylene through the mixing of polytetrafluoroethylene powder and the material, and the low-molecular polyethylene wax wraps the polytetrafluoroethylene powder in the extrusion mixing process, so that the polytetrafluoroethylene powder and the low-molecular polyethylene wax form a 'sea-island' structure. In the material injection molding process, the polytetrafluoroethylene wrapped by the low-molecular polyethylene wax is easier to migrate to the surface of the melt under the combination of a high-speed high-pressure injection molding process, so that the friction force between the ABS melt and the surface of a mold cavity of a mold can be obviously reduced, meanwhile, gas is prevented from migrating to the surface, and therefore, the generation of silver marks and gas marks can be effectively prevented.

In addition, the middle layer of the micro-foaming ABS material prepared by adopting the light-weight micro-foaming technical means provided by the invention is compact and tiny foam holes, and the weight reduction effect of 10-20% can be realized, so that the product cost is reduced.

The silver element type aluminum powder with the particle size of 14 mu m provided by the invention is used as a special pigment, presents metal texture for the product, and can basically achieve the spraying effect, thereby replacing the spraying or electroplating process, reducing the process flow, being capable of being recycled in percentage and used for the second time, avoiding the environmental pollution and reducing the product cost.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following description will clearly and completely describe the embodiments of the present invention, and obviously, the described embodiments are a part of the embodiments of the present invention, but 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.

The invention also provides the following formula and preparation method examples:

TABLE 1

Wherein, the micro-foaming master batches in the examples 1-3 and the comparative example 1 contain 20 percent of AC foaming agent, 60 percent of ABS, 12 percent of lubricant polyethylene wax, 5 percent of antioxidant 1010 and 3 percent of talcum powder; the micro-foamed masterbatch of comparative example 2 contained 20% AC foaming agent and 80% ABS.

Weighing corresponding raw materials according to the weight parts of the above examples and comparative examples, and adding the raw materials into a high-speed stirrer to be uniformly mixed at a high speed to obtain a premix; extruding the premix in a double-screw extruder and granulating to obtain a micro-foaming ABS material; the temperature of the double-screw extruder charging barrel is 180-240 ℃, and the screw rotating speed is 500 r/min.

Mixing 96% of the obtained micro-foaming ABS material and 4% of foaming agent master batch in a high-speed mixer to obtain a uniform mixture;

adding the obtained uniform mixture into an injection molding machine, and performing injection molding to obtain a corresponding sample; wherein the temperature of the charging barrel of the injection molding machine is set to be 220-280 ℃, the injection pressure is 80MPa, and the injection speed is 90 mm/s.

The injection molded samples prepared from the above example and comparative example materials were subjected to relevant tests or experiments. The weight loss proportion test method comprises the following steps: the net weight is the difference between the weight of the unfoamed article and the weight of the microfoamed article of the injection molded article, divided by the weight of the unfoamed article.

The appearance defect degree is mainly used for observing the number and the depth of appearance gas marks and silver marks of the injection molding product; and scoring, wherein the evaluation criteria are as follows:

the appearance of the samples was evaluated in 10 persons and averaged.

The test results are shown in the following table:

TABLE 2

Test items	Example 1	Example 2	Example 3	Comparative example 1	Comparative example 2
						Weight loss ratio	14％	10％	16％	8％	6％
Degree of appearance defect	4.5	4.2	4.8	3.4	2.2
						Metallic texture	Strong, and uniform	Strong, and uniform	Strong, and uniform	In general, and are not uniform	Weak (weak)

As can be seen from the above table: the addition of the foaming master batch provided by the invention can effectively reduce the weight of the product, the polytetrafluoroethylene powder can effectively inhibit the generation of gas marks and silver marks of the product, and the inhibiting effect also shows a trend of becoming better along with the increase of the specific gravity of the polytetrafluoroethylene.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (9)

1. The micro-foaming ABS material is characterized by comprising the following raw materials in parts by weight:

70-99 parts of ABS

0.5 to 5 portions of compatilizer

0.1 to 6 portions of pigment

0.1-5 parts of micro-foaming master batch

0.1-10 parts of micro-foaming auxiliary agent

0.05 to 2 portions of dispersant

0.05-1 part of antioxidant

0.05 to 1 portion of light stabilizer

The micro-foaming auxiliary agent is polytetrafluoroethylene powder;

the micro-foaming master batch comprises polyethylene wax;

the pigment is silver-element aluminum powder with the particle size of 14 mu m.

2. The microfoamed ABS material according to claim 1, characterized in that: the micro-foaming master batch is a master batch containing 20% of AC foaming agent.

3. The microfoamed ABS material according to claim 1, characterized in that: the micro-foaming master batch also comprises an antioxidant and a foam cell nucleating agent.

4. The microfoamed ABS material according to claim 1, characterized in that: the compatilizer is gamma-aminopropyl triethoxysilane.

5. The microfoamed ABS material according to claim 1, characterized in that: the dispersant is ethylene bis stearamide.

6. The microfoamed ABS material according to claim 1, characterized in that: the antioxidant is antioxidant 1010.

7. The microfoamed ABS material according to claim 1, characterized in that: the light stabilizer is 2- [ 2-hydroxy-3, 5-bis (1, 1-dimethylpropylphenyl) ] -2H-benzotriazole.

8. A preparation method of a high-surface-quality light injection molding material, which is characterized in that the microcellular ABS material according to any one of claims 1 to 7 is adopted, and comprises the following steps:

step a, preparing an ABS material, namely weighing ABS, a compatilizer, a pigment, a micro-foaming auxiliary agent, a dispersant, an antioxidant and a light stabilizer according to the weight percentage, and then adding the weighed ABS, the compatilizer, the pigment, the micro-foaming auxiliary agent, the dispersant, the antioxidant and the light stabilizer into a high-speed mixer to be uniformly mixed at a high speed to obtain a premix; extruding the premix in a double-screw extruder and granulating to obtain the ABS material;

b, putting 96% of the ABS material obtained in the step a and 4% of the micro-foaming master batch into a high-speed mixer for mixing to obtain a uniform mixture;

c, adding the uniform mixture obtained in the step b into an injection molding machine, and performing injection molding to obtain a high-surface-quality light injection molding material; wherein the temperature of the charging barrel of the injection molding machine is set to be 220-280 ℃, the injection pressure is 60-100MPa, and the injection speed is 70-90 mm/s.

9. The method for preparing a light injection molding material with high surface quality according to claim 8, characterized in that: in the step a, the temperature of the double-screw extruder charging barrel is 180 ℃ and 240 ℃, and the screw rotating speed is 500 r/min.