CN106905650B

CN106905650B - High impact polymethyl methacrylate alloy resin composition and preparation method thereof

Info

Publication number: CN106905650B
Application number: CN201710154742.3A
Authority: CN
Inventors: 查超; 周霆; 罗明华; 辛敏琦
Original assignee: Shanghai Kumho Sunny Plastics Co Ltd
Current assignee: Shanghai Kumho Sunny Plastics Co Ltd
Priority date: 2017-03-15
Filing date: 2017-03-15
Publication date: 2019-12-06
Anticipated expiration: 2037-03-15
Also published as: CN106905650A

Abstract

The invention provides a high-impact polymethyl methacrylate alloy resin composition and a preparation method thereof, wherein the composition comprises the following components in parts by weight: 65-82 parts of PMMA resin, 10-20 parts of toughening agent, 6-15 parts of ethylene-vinyl acetate copolymer and 0.5-1.5 parts of processing aid. The components are premixed in a high-speed mixer for 3-10 minutes, and then the premixed material is extruded and granulated by a double-screw extruder to obtain the high-impact PMMA alloy resin composition. The PMMA alloy resin provided by the invention has excellent mechanical properties, especially very excellent impact property, while basically maintaining the transparency of pure PMMA, and the notch impact strength of the high-impact PMMA alloy resin composition can be up to 15 times of that of the pure PMMA.

Description

High impact polymethyl methacrylate alloy resin composition and preparation method thereof

Technical Field

The invention relates to a transparent toughened PMMA alloy resin composition and a preparation method thereof, in particular to a high-impact-resistant PMMA alloy resin composition and a preparation method thereof.

background

Pure polymethyl methacrylate (PMMA) resin has excellent optical transmission performance, and the transparency can reach 92%. Meanwhile, the coating also has excellent weather resistance, mechanical strength, scratch resistance and the like. And because of the high transparency of PMMA, PMMA has excellent dyeing performance, and can be easily dyed into high-gloss piano black by black toner, but the toughness of pure PMMA resin is very low (the normal temperature notch cantilever beam impact strength is 1.2kJ/m2), so that the defect that the PMMA resin is greatly limited in application.

The PMMA is toughened by the rubber, so that the impact resistance of the material can be effectively improved, the piano black effect can be prepared under the condition that the transparency of the base material is ensured, and the PMMA is gradually applied to automobile parts with low toughness requirements, such as automobile outer column decorative plates, due to excellent weather resistance and scratch resistance.

there are two types of rubbers commonly used for PMMA toughening: firstly, the MBS rubber with a core-shell structure, which takes butadiene rubber as a core and methyl methacrylate resin as a shell, can improve the impact strength of PMMA by about 8 times to the maximum, but because the rubber is butadiene rubber, the weather resistance is poor, and the use requirement of automobile exterior trim cannot be met; secondly, the ACR rubber with a core-shell structure, which takes acrylic rubber as a core and methacrylic resin as a shell, can improve the impact strength by only 6 times at most. The two rubbers are required to achieve the optimal toughening effect, and the addition amount of the rubbers is more than 20phr, so that the rigidity, the heat resistance and the surface hardness of the material are obviously reduced.

However, both of the above toughening methods have their own problems, and neither of the impact properties can satisfy the automotive parts having high impact requirements.

disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a high-impact PMMA alloy resin composition and a preparation method thereof, and the PMMA alloy resin composition has the characteristics of simple preparation process, excellent comprehensive mechanical property, high transmittance and easy piano black effect dyeing and the like.

The purpose of the invention is realized by the following technical scheme:

the invention provides a high-impact polymethyl methacrylate alloy resin composition which is characterized by comprising the following components in parts by weight:

Preferably, the weight average relative molecular mass of the polymethyl methacrylate resin is 50,000-150,000 g/mol.

preferably, the toughening agent is a core-shell structure toughening agent, wherein the core layer is butyl acrylate rubber, the shell layer is methacrylic resin, and the refractive index is 1.488-1.492.

Preferably, the weight average molecular weight of the ethylene-vinyl acetate copolymer is 100,000-180,000g/mol, the mass content of vinyl acetate is 25-28%, and when the content of the vinyl acetate is in the range, the refractive index of the corresponding copolymer is 1.488-1.492, which is close to that of pure PMMA, and the transparent matrix can be obtained by blending the two.

preferably, the ethylene-vinyl acetate copolymer has a refractive index of 1.485 to 1.495.

Preferably, the processing aid comprises at least one of an antioxidant and a lubricant.

Preferably, the antioxidant is a hindered phenol antioxidant or a phosphite antioxidant, and the lubricant is pentaerythritol stearate or ethylene bis-stearamide.

The invention also provides a preparation method of the high-impact polymethyl methacrylate alloy resin composition, which comprises the following steps:

S1, preparing the following components in parts by weight: 65-82 parts of PMMA resin, 10-20 parts of toughening agent, 6-15 parts of ethylene-vinyl acetate copolymer and 0.5-1.5 parts of processing aid;

s2, premixing the materials prepared in the step S1 in a high-speed mixer;

s3, melting and extruding the premix obtained in the step S2 through a double-screw extruder at the extrusion temperature of 200-240 ℃ and the screw rotating speed of 200-500 r/min, and cooling and granulating to obtain the high-impact polymethyl methacrylate alloy resin composition.

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

1. The invention adopts the technical means of blending modification to blend PMMA resin and ethylene-vinyl acetate copolymer, so that the molecular chain flexibility of the matrix macromolecules is improved, the toughening level of the matrix is improved easily, and the high impact PMMA alloy resin composition with excellent comprehensive performance is prepared by blending with core-shell structure acrylate;

2. The invention adopts a method of introducing a second-phase ethylene-vinyl acetate copolymer to improve the toughening level of a matrix, so that the toughness of the material can be obviously improved when the addition amount of a toughening agent is less than 20 parts, and the notch impact strength of the high-impact PMMA alloy resin composition can be up to 15 times of that of pure PMMA;

3. the invention adopts ethylene-vinyl acetate copolymer with 25-28% of vinyl acetate content, the refractive index is 1.485-1.495, the refractive index is equivalent to that of PMMA matrix and toughening agent, and transparent alloy material is obtained.

4. The preparation method provided by the invention is simple in process and low in cost, and the prepared PMMA alloy resin is particularly suitable for being applied to the fields of automobile exterior trim and the like.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

In the following examples and comparative examples, the raw materials used were as follows:

PMMA: degussel 8N, weight average relative molecular weight 80,000-100,000g/mol, refractive index 1.49;

A toughening agent: LG chemical EM600, refractive index 1.49;

PEVA: the Searnis EVA2861, the vinyl acetate content is 28 percent, and the refractive index is 1.491;

Antioxidant: ciba: TG-1076

lubricant: commercial EBS (ethylene bis stearamide)

Examples 1 to 4

Examples 1-4 provide a high impact PMMA alloy resin composition having the components and parts by weight shown in table 2.

The preparation method of the PMMA resin composition with improved wear resistance comprises the following steps:

(1) Preparing materials according to the following components and contents: 65-82 parts of PMMA resin, 10-20 parts of toughening agent, 6-15phr of ethylene-vinyl acetate copolymer and 0.5-1.5 parts of processing aid;

(2) Premixing the materials prepared in the step (1) in a high-speed mixer;

(3) And (3) melting and extruding the premix obtained in the step (2) through a double-screw extruder at the extrusion temperature of 200-240 ℃ and the screw rotating speed of 200-500 r/min, and cooling and granulating to obtain the high-impact polymethyl methacrylate (PMMA) alloy resin composition.

Comparative examples 1 to 5

comparative examples 1 to 5 provide high impact PMMA alloy resin compositions, the components and parts by weight of which are shown in table 2. The preparation method is the same as the embodiment.

Effect verification:

The resins prepared in the examples and comparative examples were injection molded into standard bars according to the ISO standard for testing, as shown in Table 1. The resins prepared in each of the examples and comparative examples were injection molded into 2mm thick plates at 230 c, and tested for transmittance and pencil hardness, as shown in table 2.

TABLE 1 physical Properties and test methods corresponding tables

Test items	Test conditions	Test method
			Tensile strength	50mm/min	ISO 527
elongation at break	50mm/min	ISO 527
			Bending strength	2mm/min	ISO 178
Flexural modulus	2mm/min	ISO 178
			IZOD notched impact strength	5.5J、23℃	ISO 180:2000
Vicat softening point	5kg，50℃/h	ISO 306
			transmittance of light	2mm thick	ISO13468
Hardness of pencil	7.5N	ISO15184

TABLE 2 examples and comparative examples

As can be seen from the data in Table 2, the addition of the second phase matrix EVA obviously improves the toughening level of the matrix, the highest notch impact strength of the material can reach 18kJ/m2, and the impact resistance is obviously improved. Meanwhile, other properties of the material have small influence, and the transparency and pencil hardness are maintained at a high level.

The invention has many applications, and the above description is only a preferred embodiment of the invention. It should be noted that the above examples are only for illustrating the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications can be made without departing from the principles of the invention and these modifications are to be considered within the scope of the invention.

Claims

1. A high-impact polymethyl methacrylate alloy resin composition is characterized by comprising the following components in parts by weight:

The PMMA resin is Degussa 8N, the toughening agent is EM600, and the ethylene-vinyl acetate copolymer is EVA 2861.

2. The high impact polymethyl methacrylate alloy resin composition according to claim 1, wherein the antioxidant is a hindered phenol antioxidant or a phosphite antioxidant, and the lubricant is pentaerythritol stearate or ethylene bis-stearamide.

3. a method for preparing the high impact polymethylmethacrylate alloy resin composition of claim 1, comprising the steps of:

s1, preparing the following components in parts by weight: 65-80 parts of PMMA resin, 10-20 parts of toughening agent, 6-15 parts of ethylene-vinyl acetate copolymer, 0.5 part of antioxidant and 0.5 part of lubricant;

s2, premixing the materials prepared in the step S1 in a high-speed mixer;