WO2022077862A1 - Pmma/ionomer/pc ternary alloy and preparation method therefor - Google Patents

Abstract

Disclosed is a PMMA/ionomer/PC ternary alloy. The PMMA/ionomer/PC ternary alloy contains the following components in parts by weight: 5-60 parts of a carboxylic acid-based ionomer, 5-95 parts of a polycarbonate, and 1-35 parts of PMMA. By compounding the three resins, not only can the pearlescent defect of a PMMA/PC alloy be significantly improved, but the ternary alloy also has the advantage of a low forming stress, thereby being beneficial for preparing high-toughness products with complex structures.

Description

A kind of PMMA/ionomer/PC ternary alloy and preparation method thereof technical field

The invention relates to the technical field of polymer materials, in particular to a PMMA/ionomer/PC ternary alloy and a preparation method thereof.

Background technique

Polycarbonate (referred to as PC) is a high molecular polymer containing carbonate groups in the molecular chain. According to the structure of the ester groups, it can be divided into aliphatic, aromatic, aliphatic-aromatic and other types. Due to the special structure of polycarbonate, it has become the fastest growing general engineering plastic among the five major engineering plastics. Polycarbonate is a synthetic material developed in the late fifties. Polycarbonate resin has outstanding impact resistance, creep resistance and dimensional stability, and is widely used in electronic appliances, rail transit and aerospace fields.

However, polycarbonate also has defects such as surface gloss, surface scratch resistance, and insufficient strength. The general solution is to blend with PMMA (polymethyl methacrylate) to form a PMMA/PC alloy. However, due to the different refractive indices of the two resin matrices of PMMA/PC, the light is refracted in the resin matrix and a pearlescent effect occurs. Chinese patent application 2018108054686 discloses a PC/PMMA composite material, in which the difference in gloss between the two is used to produce a pearlescent effect, avoiding the easy formation of the surface of the workpiece caused by the addition of aluminum powder or pearlescent powder to conventional silver pearlescent spray-free materials. Flow marks or weld line problems. Chinese patent application 2016104106339 discloses a transparent scratch-resistant PC/PMMA alloy, by using metal organic compound stabilizer A, phosphorus-containing compound stabilizer B, and adding stabilizer B into the molten system by side feeding , which can solve the problems of pearl luster and yellowing in the preparation of transparent scratch-resistant PC resin compositions in the prior art. Chinese patent application No. 2018106764638 discloses a transparent high-hardness PC composition. By blending polyester copolymer, styrene copolymer and PC, it solves the problems of poor compatibility, poor toughness, and opacity between PC and PMMA alloy in the prior art. Pearlescent phenomenon.

Regarding the molding stress, the main chain of the polycarbonate molecule is relatively rigid, and the adjustment of the molecular chain during the injection molding process is relatively slow, resulting in a high molding stress. Generally, there are three main ways to reduce stress: 1. Reduce the viscosity of polycarbonate, but it will lead to a significant drop in mechanical properties; 2. Reduce stress by adjusting molding parameters during the molding process; 3. Introduce ABS resin Made of PC/ABS alloy, but the alloy has low surface hardness and poor scratch resistance.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned technical defects and provide a PMMA/ionomer/PC ternary alloy, which can greatly improve the pearlescent effect, and has the advantages of low forming stress, which is conducive to the preparation of high-toughness products with complex structures.

Another object of the present invention is to provide a method for preparing the above-mentioned ternary alloy.

The present invention is achieved through the following technical solutions:

A PMMA/ionomer/PC ternary alloy, by weight, comprising the following components:

Carboxylic acid group ionomer 5-60 copies;

Polycarbonate 5-95 copies;

PMMA 1-35 servings.

Preferably, in parts by weight, the following components are included:

Carboxylic acid group ionomer 15-35 parts;

Polycarbonate 25-75 copies;

10-25 servings of PMMA.

The carboxylic acid group ionomer is an ethylene/methacrylic acid copolymer, wherein 40mol%-90mol% of the carboxyl groups of the methacrylic acid units are neutralized by metal ions.

The metal ion is selected from at least one of sodium ion, zinc ion, magnesium ion and potassium ion.

The melt index of the carboxylic acid-based ionomer is between 0.5-5g/10min, and the test conditions are 190°C and 2.16kg.

The PMMA melt index is between 12-22g/10min, and the test conditions are 230°C and 3.8kg.

The polycarbonate melt index is between 3-22g/10min, and the test conditions are 300°C and 1.2kg.

Polycarbonates are branched thermoplastic polymers or copolymers obtained from the reaction of dihydroxy compounds or a small amount of polyhydroxy compounds with phosgene or carbonic acid diesters. Polycarbonate resins can be produced by a phosgene method (interfacial polymerization method) or a melt method (transesterification method). The polycarbonate resin is also provided by subjecting the polycarbonate resin produced by the melt method to a post-treatment to adjust the amount of terminal hydroxyl groups.

In the polycarbonate segment obtained by the phosgene method, the repeating unit is formed by the reaction of bisphenol A and phosgene. In the polycarbonate segment obtained by the transesterification method, the repeating unit is formed by the reaction of diphenyl carbonate and bisphenol A.

In order to improve the melt processability, 0-3 parts by weight of lubricant can also be added.

Described lubricant is selected from at least one in stearate class lubricant, fatty acid class lubricant, stearate class lubricant; Described stearate class lubricant is selected from calcium stearate, At least one in magnesium stearate, zinc stearate; Described fatty acid lubricant is selected from at least one in fatty acid, fatty acid derivative, fatty acid ester; Described stearic ester lubricant is selected from At least one of glycerol monostearate and pentaerythritol stearate.

The preparation method of the above-mentioned PMMA/ionomer/PC ternary alloy comprises the following steps: according to the proportion, after mixing the components uniformly, extruding and granulating through a twin-screw extruder, the screw temperature range is 200-270 ℃, the rotating speed range is 180-500r/min, and the PMMA/ionomer/PC ternary alloy is obtained.

The application of the above-mentioned PMMA/ionomer/PC ternary alloy is used to prepare scratch-resistant, high-gloss articles.

The present invention has the following beneficial effects:

The PMMA/ionomer/PC ternary alloy of the present invention obviously improves the pearlescent defect of the PMMA/PC binary alloy. By introducing a carboxylic acid-based ionomer with a flexible molecular chain, it can be alloyed with PC/PMMA to reduce the stress generated during the molding process, and can also improve the surface hardness of the ternary alloy.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

The sources of raw materials used in the present invention are as follows:

Carboxylic ionomer A: the main chain is an ethylene/methacrylic acid copolymer, the melt index is 3.5g/10min, the test conditions are 190°C, 2.16kg, and 78mol% of the carboxyl groups of the methacrylic acid units are neutralized by sodium ions.

Carboxylic acid group ionomer B: the main chain is ethylene/methacrylic acid copolymer, the melt index is 1.4g/10min, the test conditions are 190°C, 2.16kg, and 45mol% of the carboxyl groups of the methacrylic acid units are neutralized by zinc ions.

Carboxylic ionomer C: the main chain is an ethylene/methacrylic acid copolymer, the melt index is 5.9 g/10min, the test conditions are 190° C., 2.16 kg, and 26 mol% of the carboxyl groups of the methacrylic acid units are neutralized by zinc ions.

Polycarbonate: brand TRIREX 3025PJ, melt index is 10g/10min, test condition is 300℃, 1.2kg;

PMMA: grade PMMA LG, melt index is 9g/10min, test conditions are 230℃, 3.8kg;

Zinc stearate: ZINC STEARATE (BS-2818), commercially available, added as a lubricant;

Various performance test methods:

(1) Internal stress test: Fix the ISO527.2-2012 tensile spline on a fixture with a curvature of 1.0, apply a solvent of toluene:ethanol=1:3, and observe the cracking time and cracking shape of the spline. The cracks within 1h after applying the solvent are recorded as grade 1, the cracks within 1-4h are recorded as grade 2, the cracks within 4-12h are recorded as grade 3, the cracks within 12-24h are recorded as grade 4, and the cracks within 24h are recorded as grade 4. Level 5. In terms of crack morphology, it is divided into two types: micro-crack and large-crack.

(2) Surface hardness test: use the pencil hardness method to evaluate, refer to the ASTM D3363-2005 standard for testing, and the test weight is 750g. The evaluation grades are divided into: 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H.

(3) Pearlescent effect: observe whether there is a pearlescent effect (observe whether the color pattern can be seen under the side light source, and calculate the production area of the pearlescent effect per unit area).

Examples and comparative examples PMMA ionomer PC ternary alloy preparation method: according to the proportion, after mixing the components uniformly, extruding and granulating through a twin-screw extruder, the screw temperature range is 200-270 ° C, and the rotating speed is 200-270 ° C. The range is 360-400 r/min, and the alloy is obtained.

Table 1: Alloys of Examples 1-6, the proportions of each component and the test results of various properties

It can be seen from Example 1/3/5 that although theoretically the higher the PMMA content, the higher the surface hardness, but if the resin ratio of the ternary alloy is not within the preferred range of the present invention, the advantage of PMMA to improve the surface hardness is difficult to manifest. .

It can be seen from Examples 1-6 that in the preferred ternary alloy ratio range, at least two of the three properties are better.

Table 2: Alloy components of Example 7-9 and the test results of various properties

Table 3: The ratio of each component of the comparative alloy and the test results of various properties

Since there is no PMMA in Comparative Example 1, there is no pearlescent effect; however, the surface hardness is low and is prone to stress cracking.

It can be seen from Comparative Examples 2-4 that, without adding carboxylic acid-based ionomer or the addition amount is insufficient, the pearlescence is obvious, and the hardness is low and stress cracking is easy.

It can be seen from Comparative Example 5 that if the amount of carboxylic acid-based ionomer added is too large, the pearlescence of the material cannot be eliminated, and the modulus of the material is reduced.

Claims (10)

1. A kind of PMMA/ionomer/PC ternary alloy is characterized in that, by weight, comprises the following components:

   Carboxylic acid group ionomer 5-60 copies;

   Polycarbonate 5-95 copies;

   PMMA 1-35 servings.
2. PMMA/ionomer/PC ternary alloy according to claim 1, is characterized in that, by weight, comprises the following components:

   Carboxylic acid group ionomer 15-35 parts;

   Polycarbonate 25-75 copies;

   10-25 servings of PMMA.
3. The PMMA/ionomer/PC ternary alloy according to claim 1, wherein the carboxylic acid group ionomer is an ethylene/methacrylic copolymer, wherein 40 mol% of the methacrylic acid unit -90 mol% of carboxyl groups are neutralized by metal ions.
4. The PMMA/ionomer/PC ternary alloy according to claim 3, wherein the metal ion is selected from at least one of sodium ion, zinc ion, magnesium ion and potassium ion.
5. The PMMA/ionomer/PC ternary alloy according to any one of claims 1-4, wherein the melt index of the carboxylic acid-based ionomer is between 0.5-5g/10min, and the test conditions It is 190 ℃, 2.16kg.
6. The PMMA/ionomer/PC ternary alloy according to claim 1, wherein the PMMA melt index is between 12-22g/10min, and the test conditions are 230°C and 3.8kg.
7. The PMMA/ionomer/PC ternary alloy according to claim 1, wherein the polycarbonate melt index is between 3-22g/10min, and the test conditions are 300°C and 1.2kg.
8. The PMMA/ionomer/PC ternary alloy according to claim 1, characterized in that, in parts by weight, further comprising 0-3 parts of lubricant.
9. The preparation method of the PMMA/ionomer/PC ternary alloy according to any one of claims 1-8, characterized in that, comprising the steps of: according to the proportioning, after mixing the components uniformly, extruding through twin-screw Machine extrusion granulation, screw temperature range is 200-270 ℃, rotating speed range is 180-500r/min, to obtain PMMA/ionomer/PC ternary alloy.
10. The application of the PMMA/ionomer/PC ternary alloy according to any one of claims 1-8, characterized in that it is used for preparing scratch-resistant and high-gloss parts.