CN112480641A

CN112480641A - High-chemical-resistance PC/ABS composite material and preparation method thereof

Info

Publication number: CN112480641A
Application number: CN202011621053.7A
Authority: CN
Inventors: 段浩; 朱从山; 司胜仁
Original assignee: Jiayirong Polymer Shanghai Co ltd
Current assignee: Jiayirong Polymer Shanghai Co ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-03-12
Anticipated expiration: 2040-12-31
Also published as: CN112480641B

Abstract

The invention provides a PC/ABS composite material with high chemical resistance and a preparation method thereof; the composite material comprises the following components in percentage by weight: 60-85% of polycarbonate; 15-40% of ABS; 0.5-5% of a compatilizer; 3-10% of a rheology modifier. The preparation method comprises the following steps: the components in the raw materials are mixed according to a certain proportion at room temperature, and then melt extrusion is carried out through a double screw, so that the PC/ABS composite material which is easy to process, excellent in mechanical property and high in chemical resistance and the preparation method thereof are prepared. The prepared composite material has excellent mechanical property, is easy to process, simultaneously keeps excellent chemical resistance and has excellent appearance.

Description

High-chemical-resistance PC/ABS composite material and preparation method thereof

Technical Field

The invention belongs to the field of macromolecules, and particularly relates to a PC/ABS composite material which is easy to process, excellent in mechanical property and high in chemical resistance, and a preparation method thereof.

Background

PC/ABS has the comprehensive characteristics of both PC and ABS, has raised flowability, improved machining performance, reduced stress sensitivity and excellent heat stability. Therefore, the optical fiber can be applied to the fields of household appliances, office equipment, communication equipment, photographic equipment, medical instruments, buildings, lighting appliances, aerospace, electronic computers, optical fibers and the like. Especially, the high-strength and high-heat-resistance parts such as automobile inner decorations, outer decorations, automobile lamps and the like are widely applied.

In recent years, the market of PC/ABS has been kept more than 10%, and with the development of industries such as automobiles, household appliances and the like, people have increasingly demanded more beautiful and higher-performance PC/ABS, and a new generation of high-performance PC/ABS alloy series materials are required to have not only excellent mechanical properties but also series of new characteristics including hydrolysis resistance, stability, spraying free, ultralow gloss, chemical resistance and the like.

Particularly, with the improvement of social aesthetic concept, the PC/ABS product needs to be painted to meet various requirements of customers on weather resistance, attractiveness and the like of the product. Poor PC/ABS chemical resistance can cause defects such as product cracking, product dimensional deformation, material embrittlement and the like after paint spraying, thereby limiting the application in this aspect.

Generally, the molecular chain of PC contains ester group, which is easy to absorb water, has poor chemical stability, especially not alkali resistance, and can be degraded by saponification even in a weak alkaline environment; in addition, the polycarbonate molecular structure has larger steric hindrance and larger residual stress of the product, so that the cracking of the product is aggravated after the product is corroded by chemical reagents. When the ester group of PC is subjected to long-term thermal processing conditions or strong shearing conditions, the PC is promoted to be further subjected to free radical chain degradation, so that the solvent resistance of the PC/ABS is poor.

The prior art discloses a modified polycarbonate plastic, which comprises the following components in percentage by mass: by the mode, the modified polycarbonate plastic has the advantages of high strength, good ductility, good toughness, high impact strength, good transparency, good corrosion resistance, excellent electrical property, good self-lubricating property, good solvent resistance, safety, practicability and the like; the prior art discloses a transparent polyester material with light absorption function and solvent cracking resistance, which comprises the following raw materials by weight of 100 percent: 65-99.5% of polyester resin; 0.4-30% of multifunctional auxiliary agent; 0.1-5% of processing aid; the multifunctional additive is a composite particle with a multiple core-shell structure, comprises an inner core, an intermediate layer and a shell layer, provides a transparent polyester material, can efficiently absorb ultraviolet light and blue light at the same time, and has excellent solvent cracking resistance, processability and high transmittance.

However, there is no good solution for solving the solvent resistance problem of PC/ABS at present, and chemical-resistant components such as high-crystallinity materials (PBT, PA and the like) are added to improve the chemical agent corrosion resistance of the material, while too much addition of the third component often causes the heat resistance and impact strength of the material to be reduced; blocking is used to improve the chemical resistance of PC, such as isocyanates, oxazolines, epoxies and dianhydrides. The end groups of the PC are reduced by the gradual polymerization and the polymer end groups are reacted, so that the chemical resistance of the PC is improved, but the problem is that the processability is lost, and the residual internal stress of the high-viscosity PC becomes a weak point of the chemical resistance due to poor processability and poor appearance of the high-viscosity PC, so that the processing temperature is required to be increased, and the thermal cracking loss is caused.

Therefore, how to balance the processability, mechanical properties and chemical resistance becomes an important subject, and how to stably, simply and effectively improve the chemical resistance and mechanical properties and processability of PC/ABS is the key to prepare high-performance PC/ABS alloy.

Disclosure of Invention

The invention aims to solve the problems in the prior art that the requirements of occasions with higher requirements and the requirements of stability are difficult to meet by the high-performance PC/ABS alloy material, and provides a PC/ABS composite material which is simple, effective and convenient to use, is easy to process, has excellent mechanical properties and high chemical resistance and a preparation method thereof.

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

the high-chemical-resistance PC/ABS composite material is prepared from raw materials consisting of polycarbonate, ABS, a compatilizer and a modifier; the compatilizer is a terpolymer obtained by copolymerizing an aromatic vinyl monomer, an acrylonitrile monomer and Glycidyl Methacrylate (GMA); the modifier is a binary copolymer formed by copolymerizing aromatic vinyl monomers and acrylonitrile monomers.

According to the preparation method of the high-chemical-resistance PC/ABS composite material, the polycarbonate, the ABS, the compatilizer and the modifier are extruded by the double screws to obtain the high-chemical-resistance PC/ABS composite material.

In the invention, the amount of the compatilizer is 0.5-5% of the sum of the weight of the polycarbonate and the ABS; the amount of the modifier is 3-10% of the sum of the weight of the polycarbonate and the ABS; in the polycarbonate and the ABS, the mass percent of the polycarbonate is 60-85%, and the balance is the ABS, so that the polycarbonate and the ABS have the advantages of easiness in processing and excellent mechanical property. The invention comprises the following components in percentage by weight:

60-85% of polycarbonate

ABS 15～40%

0.5 to 5 percent of compatilizer

3-10% of a modifier.

Preferably, the using amount of the compatilizer is 1-3% of the sum of the weight of the polycarbonate and the ABS; the amount of the modifier is 6-8% of the total weight of the polycarbonate and the ABS.

The compatilizer is a terpolymer prepared by copolymerizing aromatic vinyl monomers, acrylonitrile monomers and Glycidyl Methacrylate (GMA); preferably, the number average molecular weight of the terpolymer is 50000-90000; preferably, the terpolymer contains 50wt% to 85wt% of aromatic vinyl monomer, 10wt% to 40wt% of acrylonitrile monomer, and the balance of glycidyl methacrylate, for example, 0.3wt% to 10wt%, preferably 0.5wt% to 5 wt%. Further preferably, the terpolymer consists of terpolymers of different glycidyl methacrylate contents; the method is beneficial to processing of PC/ABS, can keep good thermal stability, has simple preparation of the compatilizer, is easy to control the polymerization process, has wide selection range of downstream processing technology, also prevents the PC from excessively forming cross-linking due to reaction so as not to be beneficial to mechanical property, reduces the end group of PC by end capping with different content of GMA, and is beneficial to improving the chemical resistance of the PC.

The modifier is a binary copolymer formed by copolymerizing aromatic vinyl monomers and acrylonitrile monomers; preferably, in the binary copolymer, the content of the acrylonitrile monomer is 15wt% to 50wt%, and the content of the aromatic vinyl monomer is the rest; more preferably, the binary copolymer has an acrylonitrile monomer content of 20 to 35wt% and an aromatic vinyl monomer content of the balance. Preferably, the weight average molecular weight of the binary copolymer is 5000-40000.

In the invention, the aromatic vinyl monomer comprises a styrene monomer, and the acrylonitrile monomer comprises an acrylonitrile monomer or an alpha-methacrylonitrile monomer; preferably, the styrene monomer comprises a styrene monomer, an alpha-methyl styrene monomer, an alpha-chlorostyrene monomer or a p-methyl styrene monomer, and the acrylonitrile monomer is an acrylonitrile monomer; more preferably, the styrene monomer is styrene monomer. The terpolymer of the invention comprises AN ST-AN-GMA terpolymer, and the bipolymer comprises AN ST-AN copolymer.

The invention provides a preparation method of the high-chemical-resistance PC/ABS composite material, which comprises the following steps:

the raw materials of the components are blended in proportion and then are extruded by a double screw to obtain the PC/ABS composite material with high chemical resistance, specifically, the processing temperature of the double screw extrusion is controlled to be 220-280 ℃, the rotating speed is 180-600 rpm, and after the discharge, the PC/ABS composite material with easy processing, excellent mechanical property and high chemical resistance is obtained after water cooling and granulation by a granulator.

The composite material prepared by the invention has excellent chemical resistance, good mechanical property, good appearance and good processability.

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

the terpolymer with the compatibilization effect can react with PC, and the end group concentration can be effectively reduced, so that the chemical resistance stability of the PC or PC/ABS is effectively improved; convenient use, no need of mother granulation, no secondary pollution, no side effects such as degradation of PC and the like.

The rheology modifier has excellent plasticizing effect, is easier to plasticize compared with similar products in the market, can be matched with high-viscosity PC, balances the excellent performance and processability of the high-viscosity PC, and provides an applicable method for preparing a high-efficiency chemical-resistant composite material; the high-crystalline material of other third components is not required to be introduced, the problems of compatibility and the like are not caused, and the formula has a simple structure and is convenient to process.

Drawings

FIG. 1 is a surface view of example 4 after solvent swelling;

FIG. 2 is a surface view of comparative example 1 after solvent swelling.

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.

The high-chemical-resistance PC/ABS composite material is prepared from four raw materials, namely polycarbonate, ABS, ST-AN-GMA terpolymer and ST-AN binary copolymer, and other components are not required to be added.

Examples and comparative examples:

the polycarbonate is low, medium and high viscosity polycarbonate, the melt indexes of 300 ℃/1.2Kg are respectively 22 g/10min, 15g/10min and 5g/10min, and the polycarbonate is a Japanese imperial.

The ABS was purchased from Korea brocade lake PD 190.

In the ST-AN-GMA terpolymer, the content of aromatic vinyl monomers is 50 to 85 weight percent, the content of acrylonitrile monomers is 10 to 40 weight percent, and the balance is glycidyl methacrylate; the terpolymer has the number average molecular weight of 50000-90000 and the melt index of 235 ℃/2.16kg is 5-15 g/10 min. The terpolymer is preferably composed of terpolymers with different glycidyl methacrylate contents, wherein the content of glycidyl methacrylate in the terpolymer with different glycidyl methacrylate contents is two or three of 0.5wt% to 3wt%, and most preferably, the content of glycidyl methacrylate in the terpolymer with different glycidyl methacrylate contents is two or three of 0.5wt%, 1 wt%, 2 wt% and 3 wt%; the terpolymer consists of a terpolymer with the content of 0.5 percent of glycidyl methacrylate and a terpolymer with the content of 1 percent of glycidyl methacrylate, and preferably the terpolymer consists of the terpolymer with the content of 0.5 percent of glycidyl methacrylate and the terpolymer with the content of 1 percent of glycidyl methacrylate by weight; can obtain the best effect of mechanical property and chemical resistance.

In the ST-AN binary copolymer, the number average molecular weight is 5000-40000, the melt index at 190 ℃/5kg is 40-200 g/10min, the ST content is 65-75 wt%, and the AN content is 25-35 wt%.

The specific components and weight percentages of the respective examples and comparative examples are shown in table 1, and all the raw materials are commercially available conventional products, wherein ST-AN-GMA (GMA = 0.5%) has a ST content of 59.5wt%, AN content of 40wt%, a GMA content of 0.5wt%, and a number average molecular weight of 30000; in ST-AN-GMA (GMA = 1%), the ST content is 59wt%, the AN content is 40wt%, the GMA content is 3wt%, and the number average molecular weight is 33000; in ST-AN-GMA (GMA = 5%), the ST content was 55wt%, the AN content was 40wt%, the GMA content was 5wt%, and the number average molecular weight was 50000. The ST-AN copolymers are three: ST-AN (Mw =5000, AN =25wt%), ST-AN (Mw =20000, AN =33wt%), ST-AN (Mw =40000, AN =25 wt%).

Uniformly mixing the raw materials according to a proportion by a conventional method, extruding and granulating by a double-screw extruder at the processing temperature of 190-230 ℃ and the rotating speed of 180-600 rpm, and after discharging, conventionally cooling by water and granulating by a granulator to obtain the PC/ABS composite material.

The above examples and comparative examples were subjected to tests for tensile strength (D638, 50 mm/min), notched impact strength (1/8 inch, ASTM D256) and chemical resistance according to conventional test methods. The results are shown in Table 2.

The chemical resistance test is that after the particles are conventionally tabletted (0.5 mm), the particles are immersed into a mixed solution of ethanol and ethyl acetate with the volume ratio of 3: 1 at room temperature, taken out every 1 minute, and observed whether cracks exist on the surface.

The results in table 2 show that the invention is suitable for PCs with different viscosities, and the chemical resistance is improved, and the invention adopts the combination of the modifier, the compatilizer and the PC to enable the PC/ABS composite material to have excellent chemical resistance and mechanical properties. Fig. 1 and fig. 2 are respectively an observation of the surfaces of example 4 and comparative example 1 after solvent swelling (time of table 2), and it can be seen that the surface of example 4 has less obvious cracks, and shows more excellent chemical resistance and apparent performance by combining table 2; the melt index (260 ℃/5 Kg) of the examples is 15 to 40g/10 min.

In example 11, ABS was from a high petrochemical wherein butadiene was 15wt%, acrylonitrile was 25wt%, weight average molecular weight was 140000; the remaining raw materials were the same as in Table 1. The test methods of table 3 are consistent with table 2.

In conclusion, the PC/ABS composite material which is easy to process, excellent in mechanical property and high in chemical resistance has excellent electrical property and mechanical property.

In the prior art, the chemical corrosion resistance and the oil resistance are improved by selecting high AN content, but the problem of poor compatibility caused by large difference of solubility parameters is caused, and the mechanical property is seriously reduced; in the prior art, chemical-resistant components such as high-crystallinity materials (PBT, PA and the like) are added to improve the chemical reagent corrosion resistance of the materials, however, excessive addition of the third component often causes the reduction of the heat resistance and the impact strength of the materials or causes new compatibility problems, thereby affecting the loss of other mechanical properties; in addition, the prior art discloses that polycarbonate, ABS, ST-AN-GMA terpolymer and ST-AN binary copolymer are extruded and granulated in the presence of a conductive agent, the chemical resistance of the product is not involved, the mechanical property of the modified product is reduced compared with that of pure PC/ABS, and particularly the notch impact strength is reduced.

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 chemical resistance PC/ABS composite material, characterized in that the composite material comprises the following components by weight percent:

60-85% of polycarbonate

ABS 15～40%

0.5 to 5 percent of compatilizer

3 to 10 percent of modifier

The compatilizer is a terpolymer formed by copolymerizing aromatic vinyl monomers, acrylonitrile monomers and glycidyl methacrylate; the rheology modifier is a binary copolymer formed by copolymerizing aromatic vinyl monomers and acrylonitrile monomers.

2. The highly chemical-resistant PC/ABS composite material according to claim 1, wherein the terpolymer contains 50 to 85wt% of aromatic vinyl monomer, 10 to 40wt% of acrylonitrile monomer, and the balance being glycidyl methacrylate.

3. The highly chemical-resistant PC/ABS composite material according to claim 2, wherein the content of glycidyl methacrylate in the terpolymer is 0.5 to 5% by weight.

4. The highly chemical-resistant PC/ABS composite material according to claim 1, wherein the number average molecular weight of the terpolymer is 50000 to 90000, and the weight average molecular weight of the terpolymer is 5000 to 50000.

5. The highly chemical-resistant PC/ABS composite material according to claim 1, wherein the content of the aromatic vinyl monomer in the binary copolymer is 50 to 85% by weight, and the content of the acrylonitrile-based monomer is 15 to 50% by weight.

6. The highly chemical-resistant PC/ABS composite material according to claim 1, wherein the weight percentage of the compatibilizer is 1 to 3%.

7. The highly chemical resistant PC/ABS composite material of claim 1, wherein the rheology modifier is present in an amount of 4 to 8 weight percent.

8. The method for preparing the high chemical resistance PC/ABS composite material according to claim 1, which comprises the following steps: and mixing polycarbonate, ABS, a compatilizer and a rheology modifier, and then extruding by using a double screw to obtain the PC/ABS composite material with high chemical resistance.

9. The method for preparing a high chemical resistance PC/ABS composite material according to claim 8, wherein the temperature of screw extrusion is 220-280 ℃ and the rotation speed is 180-600 rpm.

10. Use of the highly chemical resistant PC/ABS composite material according to claim 1 for the preparation of a chemical resistant material.