CN112724632A

CN112724632A - High-heat-resistance stable PC material and preparation method and application thereof

Info

Publication number: CN112724632A
Application number: CN202011520600.2A
Authority: CN
Inventors: 刘贤文; 杨燕; 李明昆; 黄险波; 叶南飚; 艾军伟; 彭民乐; 丁超
Original assignee: Kingfa Science and Technology Co Ltd
Current assignee: Kingfa Science and Technology Co Ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-04-30

Abstract

The invention relates to a high heat-resistant and stable PC material, and a preparation method and application thereof. The high heat-resistant stable PC material comprises polycarbonate, filler, aromatic hydrocarbon derivatives and other functional auxiliaries; the PC material provided by the invention has good thermal processing stability, can obviously reduce appearance defects, keeps good performance and appearance under high-temperature and high-humidity storage conditions, and can be widely used for manufacturing large-size workpieces.

Description

High-heat-resistance stable PC material and preparation method and application thereof

Technical Field

The invention belongs to the technical field of engineering plastics, and particularly relates to a high-heat-resistance stable PC material, and a preparation method and application thereof.

Background

Polycarbonate (PC) is an engineering plastic with excellent performance, has good comprehensive performance, high mechanical strength, good impact toughness, stable size, good heat resistance and good electrical insulation, and has wide application in the fields of household appliances, digital products, IT products and the like. With the requirement for thinning and lightening of televisions being improved, the corresponding plastic material not only needs to have good mechanical property and fluidity, but also needs to have higher heat resistance so as to ensure the requirement for large-size processing.

However, in the injection molding process of large-size parts, the PC resin has long retention time in the screw and is easy to decompose to cause appearance defects. How to improve the heat resistance and stable processability of PC is very critical.

Metal impurities, basic species, in polycarbonate compositions initiate catalysis at elevated temperatures during processing resulting in a decrease in the molecular weight of the polycarbonate, which can result in a macroscopic appearance of a polycarbonate article as a decrease in mechanical properties or as surface defects. Therefore, the selection of the components of the polycarbonate composition is critical.

There are studies that have been proposed to add acidic compounds to polycarbonate compositions to neutralize or inactivate harmful components that cause decomposition of the polycarbonate.

US 2006/0287422 a1 describes thermoplastic compositions containing polycarbonate, inorganic filler and an acid or acid salt and optionally other thermoplastic polymers such as polyesters and (rubber-modified) vinyl copolymers as a blend. This patent attenuates heat-induced molecular weight reduction of polycarbonates by the addition of acids or acidic salts and results in improved impact strength and ductility.

EP1893691a1 discloses compositions comprising an aromatic polycarbonate, an aromatic polyester, a filler, a rubber-containing copolymer and a stabilizer (e.g. an aqueous solution of phosphoric acid). The compositions are suitable for the production of moulded bodies having good mechanical properties and good surface quality.

EP0576950A2 and WO 2007/065579A 1 disclose polycarbonate ABS compositions which contain basic impurities and are stabilized with organic carboxylic acids.

WO 2010/063381A 1 discloses impact-modified polycarbonate compositions comprising polycarbonate, a basic doped emulsion graft polymer and an acidic phosphorus-containing compound having at least one P-OH-functionality, which polycarbonate compositions are both hydrolytically and process stable.

WO 2009/118114 a1 discloses impact-modified polycarbonate compositions comprising polycarbonate, a rubber-modified graft polymer containing manufacturing-relevant fatty acid salt emulsifier residues, wherein the graft polymer in aqueous dispersion has a pH of greater than 7, and acidic additives such as hydroxyl-functionalized mono-and polycarboxylic acids and sodium and potassium salts of phosphoric acid and phosphoric acid. The polycarbonate compositions have a light natural hue, good hydrolytic and processing stability.

WO 2013/060687 a1 discloses impact-modified polycarbonate compositions comprising bronsted acidic compounds (such as phosphoric acid, phosphorous acid, phosphinic acid and alkylated/arylated derivatives thereof) applied to inorganic or organic adsorbents or absorbents, which have good natural color tone, improved thermal stability and improved processing stability (stability measure for gloss at different processing temperatures).

WO 2013/060685 a1 discloses a process for the preparation of stabilized impact-modified polycarbonate compositions by applying an acidic compound in a highly diluted aqueous solution to a graft polymer powder and then compounding the acidic compound-treated powder with polycarbonate to improve stability.

However, in practical applications, when the stabilizers described in the prior art are used in the injection molding process for preparing polycarbonate compositions, dispersion control of the stabilizers in melt blending with polycarbonate is a technical difficulty, and is generally controlled by screw combination, feeding amount and rotating speed, but the dispersion effect is difficult to evaluate. Therefore, the use amount of the stabilizer is difficult to accurately control, and the stabilizer needs to be added in an excessive amount, so that the application economy is reduced.

In addition, excessive addition of the acidic stabilizer may cause failure of the polycarbonate composition in long-term use, such as severe failure phenomena of sharp drop in properties, surface powdering and cracking under high-temperature and high-humidity storage conditions.

Therefore, the development of a new stabilizer for endowing the polycarbonate composition with better thermal stability and a reasonable thermal stability evaluation method for more precise control of the addition amount of the stabilizer have important research significance and economic value.

Disclosure of Invention

The invention aims to overcome the defects that the dispersion control is difficult when the stabilizing agent selected in the polycarbonate composition and the polycarbonate are melt blended in the prior art, and the polycarbonate composition fails in long-term use due to excessive addition of the acidic stabilizing agent, and provides a high-heat-resistant stable PC material. The research of the invention finds that the degradation of polycarbonate in the processing process can be reduced by taking a proper amount of specific aromatic hydrocarbon derivatives as heat stabilizers, so that better high-heat stability is provided for PC materials, and meanwhile, the dispersion problem and excessive addition of the stabilizers are avoided. The PC material provided by the invention has good thermal processing stability, can obviously reduce appearance defects, and keeps good performance and appearance under high-temperature and high-humidity storage conditions.

Another object of the present invention is to provide a method for preparing the PC material with high heat resistance and stability.

Another object of the present invention is to provide the use of the above PC material with high heat resistance and stability for the preparation of large-sized articles.

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

a high heat-resistant stable PC material comprises the following components in parts by weight:

the aromatic hydrocarbon derivative contains one or more of the following groups: a phenol group, an acrylate group, a phosphate group, or a furanone group.

The invention innovatively uses a wide spiral line die (as shown in figure 1) to evaluate the heat resistance stability of the material, and the die can be used for visually representing the degradation degree of the material by distinguishing the material flower. The specific evaluation method is as follows: the components of the PC material are added into an injection molding machine, the PC material is melted at the temperature of 270-290 ℃, the PC material is molded in a mold, the material pattern condition on the surface is observed, the degradation degree of the PC material can be known, and the thermal stability of the PC material is further evaluated. Meanwhile, the addition amount of the stabilizer can be more accurately regulated and controlled by using the evaluation method, and the problems that the cost is increased due to transitional addition and the PC material is invalid in long-term use are solved.

It has been found that aromatic hydrocarbon derivatives containing specific groups (phenolic group, acrylate group, phosphate group or furanone group) as stabilizers can react preferentially with carbon free radical or peroxy radical generated by isopropylidene cleavage in polycarbonate molecule to inactivate the carbon free radical or peroxy radical, thereby inhibiting or delaying the continuous chain degradation of polycarbonate; on the other hand, trace impurities in polycarbonate systems can lead to deterioration of the properties of the polycarbonate, especially in the presence of water; the arene derivative in the invention can reduce the activity of trace impurities.

By adding the aromatic hydrocarbon derivative with proper amount, the invention not only can keep the high toughness mechanical property of the polycarbonate, but also can avoid the failure of the PC material in long-term use. The PC material provided by the invention has good thermal processing stability, can obviously reduce appearance defects, and keeps good performance and appearance under high-temperature and high-humidity storage conditions.

Preferably, the high heat-resistant and stable PC material comprises the following components in parts by weight:

polycarbonate, fillers, as are conventional in the art, may be used in the present invention.

Preferably, the polycarbonate is bisphenol A polycarbonate and has a molecular weight of 10000-40000.

Preferably, the filler is one or more of glass fiber, talcum powder, wollastonite or whisker.

More preferably, the filler is glass fiber; the content of the B element in the glass fiber is higher than 2000ppm, and the content of calcium is lower than 9000 ppm.

Preferably, the aromatic hydrocarbon derivative contains one or more of the following groups: hydroxylamine groups, bisphenol monoacrylate groups, ortho-propenyl-substituted phenolic groups or benzofuranone groups.

More preferably, the aromatic hydrocarbon derivative is an organophosphite (e.g., triphenyl phosphite, tris- (2, 6-dimethylphenyl) phosphite, tris-nonylphenyl phosphite, dimethylphenyl phosphonate, trimethyl phosphate, and the like), an alkylated monophenol or polyphenol (e.g., 2 '-methylenebis (4-methyl-6-tert-butylphenol)), an alkylated reaction product of a polyphenol and a diene (e.g., arylbenzofuranone), a butylated reaction product of p-cresol or dicyclopentadiene (e.g., 4-methyl-phenol and dicyclopentadiene), an alkylated hydroquinone (e.g., 2' -ethylenebis (4, 6-di-tert-butylphenol)), an alkylene-bisphenol (e.g., benzotriazolyl-alkylene bisphenol), a bis-phenol, a bis-methyl-2, 6-di-tert-butylphenol), a bis-phenol, benzyl compounds (e.g. 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene), polyol esters (e.g. 1,3, 5-tris [ [4- (1, 1-dimethylethyl) -3-hydroxy-2, 6-dimethylphenyl ] methyl ] -1,3, 5-triazine-2, 4, 6-trione), benzotriazoles (e.g. 2- (2 '-hydroxy-5' -tert-octylphenyl) benzotriazole) or benzophenones (e.g. 2, 4-p-bromobenzylbenzophenone).

Preferably, the aromatic hydrocarbon derivative contains a phenol group and a phosphoric acid group, wherein the aromatic hydrocarbon derivative contains 50-70 wt% of the phenol group and 50-30 wt% of the phosphoric acid group, based on the weight of the aromatic hydrocarbon derivative; still more preferably 60% and 40%, respectively.

Aromatic hydrocarbon derivatives with phenol groups and phosphate groups are matched with each other in a synergistic manner, so that the aromatic hydrocarbon derivatives can be regenerated, the stability effect is prolonged, and the PC material is endowed with high heat-resistant effect and long-term stability. The principle is that the aromatic hydrocarbon derivative containing a phenol group is combined with a carbon oxygen free radical to generate a transition product peroxy free radical, and the aromatic hydrocarbon derivative containing a phosphate group is combined with the carbon oxygen free radical to generate a transition product aryl phosphorus hydroxyl; the aryl phosphine can react with peroxy radicals to regenerate aromatic hydrocarbon derivatives containing phenolic groups.

Preferably, the light transmittance of the aromatic hydrocarbon derivative under 450-500 nm is not less than 95.0%.

The PC material provided by the invention can also comprise other conventional functional additives in the field to obtain better or new performance, and the type and the dosage of each functional additive can be selected and adjusted according to actual needs.

Preferably, the other functional auxiliary agent is one or more of a stabilizer (e.g., an epoxy-based stabilizer, the weight part of which is 0.1 to 0.3), a flame retardant (e.g., a sulfonate-based flame retardant, the weight part of which is 0.1 to 10), an anti-dripping agent (e.g., polytetrafluoroethylene, the weight part of which is 0.2 to 0.6), a lubricant (e.g., a pentaerythritol-based lubricant, the weight part of which is 0.1 to 0.5), a mold release agent (e.g., a silicone, the weight part of which is 0.1 to 0.5), an antistatic agent (e.g., monoglyceride, the weight part of which is 0.1 to 2), an antibacterial agent (e.g., silver ions, the weight part of which is 0.1 to 0.5), an antioxidant (e.g., a thiopropionate-based antioxidant, the weight part of which is 0.1 to 0.5), or a colorant (e.g., titanium dioxide, the weight part of which is 0.1 to 4.

In addition, in general, if an antioxidant is added, the antioxidant is consumed or migrates out during long-term use of the material. The aromatic hydrocarbon derivative has the effect of prolonging the stability, can still endow the PC material with higher heat-resistant effect and long-term stability under the condition of adding the antioxidant, and can prevent the phenomena of sharp performance reduction, surface pulverization, cracking and the like under the high-temperature and high-humidity storage condition from serious failure.

The preparation method of the high heat-resistant and stable PC material comprises the following steps: and uniformly mixing polycarbonate, filler, aromatic hydrocarbon derivative and other functional additives, melting, and performing injection molding to obtain the high-heat-resistance stable PC material.

The dispersion effect of the aromatic hydrocarbon derivative can be improved by the pre-mixing pretreatment.

Preferably, the preparation method of the high heat-resistant and stable PC material comprises the following steps: and (3) mixing the polycarbonate and the aromatic hydrocarbon derivative (for example, mixing for 5s in a high-speed mixer), adding the filler and other functional additives, uniformly mixing, melting, and performing injection molding to obtain the high-heat-resistance stable PC material.

The application of the high heat-resistant and stable PC material in preparing large-size parts is also disclosed in the invention.

In general, a product having a size of not less than 1000mm x 400mm is referred to as a large-sized product.

Preferably, the high heat-resistant and stable PC material is applied to the preparation of televisions or network converters.

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

the PC material provided by the invention has good thermal processing stability, can obviously reduce appearance defects, keeps good performance and appearance under high-temperature and high-humidity storage conditions, and can be widely used for manufacturing large-size workpieces.

Drawings

FIG. 1 is a diagram of a mold selected for stability evaluation.

Detailed Description

The invention is further illustrated by the following examples. These examples are intended to illustrate the invention and are not intended to limit the scope of the invention. Experimental procedures without specific conditions noted in the examples below, generally according to conditions conventional in the art or as suggested by the manufacturer; the raw materials, reagents and the like used are, unless otherwise specified, those commercially available from the conventional markets and the like. Any insubstantial changes and substitutions made by those skilled in the art based on the present invention are intended to be covered by the claims.

Some of the reagents selected in the examples and comparative examples of the present invention are described below:

polycarbonate # 1, PC 130010 NP (bisphenol a polycarbonate), LG chemical, molecular weight 22000;

polycarbonate # 2, PC 141R (ester-exchanged aromatic polycarbonate), SABIC, molecular weight 23000;

glass fiber No. 1, TLD, Taishan glass fiber, element B content of 30000ppm, calcium content of 4000ppm,

2# glass fiber, ECS303W-3, Chongqing international composite material, 5800ppm of B element content, 10000ppm of calcium content,

aromatic hydrocarbon derivative # 1, (alkylated hydroquinones), 2246, natural pharmaceuticals, having a light transmittance of 99% at 450nm and a light transmittance of 98% at 500nm, and having the following structural formula:

aromatic hydrocarbon derivative 2#, 2,2' -methylenebis (4-methyl-6-tert-butylphenol) (polyol esters), AT 2246, Centai chemical Co., Ltd. in Tianjin, the light transmittance AT 450nm was 97%, and the light transmittance AT 500nm was 95%.

Aromatic hydrocarbon derivative 3#, 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene (benzyl compounds), TH-330, Shanghai Yi En chemical technology Co., Ltd., light transmittance at 450nm is 99%, light transmittance at 500nm is 96%,

the aromatic hydrocarbon derivative 4#, 1,3, 5-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) -1,3, 5-triazine-2, 4,6(1H,3H,5H) -trione, 1544971, MREDA, had a light transmittance at 450nm of 89%, and a light transmittance at 500nm of 88%.

Antioxidant a, 3, 9-bis [1, 1-dimethyl-2- [ (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy ] ethyl ] -2,4,8, 10-tetraoxaspiro [5.5] undecane, IRGANOX 1076, basf;

antioxidant B, 1,3, 5-tris (3, 5-di-tert-butyl-4-hydroxyphenylpropionyloxyethyl) isocyanurate IRGANOX 168, basf;

thermal stabilizers tris [2, 4-di-tert-butylphenyl ] phosphite (organophosphite), IRGANOX 168, BASF, had a light transmittance at 450nm of 89% and a light transmittance at 500nm of 88%.

The high heat-resistant and stable PC material of each embodiment and comparative example of the invention is prepared by the following steps: and (2) uniformly mixing the polycarbonate and the aromatic hydrocarbon derivative, uniformly mixing the mixture, the filler (glass fiber) and other functional auxiliaries (if any), melting, and performing injection molding to obtain the high-heat-resistance stable PC material.

The stability test method of the high heat-resistant and stable PC material of each example and comparative example of the invention is as follows:

(1) and (3) stability testing:

adding the components of the high-heat-resistance stable PC material into an injection molding machine, melting at 270-290 ℃, molding in a wide spiral line mold (self-made) as shown in figure 1, and observing the material flower condition on the surface. The long dimension of the mold runner is thin, and the flowing condition of resin in the injection molding of large-size parts can be simulated.

Specifically, the structure of a wide spiral mold (width 50mm) is shown in fig. 1.

And (3) judging standard: observing the density and the length of the material flower, and determining the defect grade of the material flower, which is specifically shown in the table 1.

TABLE 1 determination of material flower defect level

Rank of	Description of the invention
		Level 1	The length of the material flower is less than 50mm and the material flower is dispersed
Stage 2	Length of material flower: 50mm-100m, and the material and flower are dispersed
		Grade 3	Length of material flower: 50mm-100m, and the material flower is concentrated into slices
4 stage	Length of material flower: 100mm-150mm
		Grade 5	Length of material flower: 150mm-200mm
Grade 6	Length of material flower: is more than 200mm

。

(2) High temperature, high humidity and aging Properties

And (3) placing a standard impact sample strip into a constant temperature and humidity box with the conditions of 85 ℃ and 85% humidity, testing the impact performance for 1000 hours, comparing the impact performance with the impact performance before initial aging, and evaluating the long-term performance by comparing the impact retention rate.

Rank of	Description of the invention
		Is excellent in	The impact retention rate is more than or equal to 90 percent, and no obvious appearance change exists
Good effect	The impact retention rate is 70-89%, and no obvious appearance change is caused
		In general	Impact retention rate of 70-89%, surface discoloration
Difference (D)	The impact retention rate is less than 70 percentSticky and discolored surface

Examples 1 to 7 and comparative examples 1 to 2

This example provides a series of highly heat stable PC materials having the formulation shown in Table 2.

TABLE 2 formulations (parts) of examples 1 to 7

Components

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Example 7

Comparative example 1

Comparative example 2

Polycarbonate 1#

89

Glass fiber 1#

10

Aromatic hydrocarbon derivative 1#

0.6

0.5

0.7

1

/

Aromatic hydrocarbon derivative 2#

0.4

0.5

0.3

/

1

/

Arene derivative 3#

/

1

/

Arene derivative 4#

/

1

/

Heat stabilizer

/

1

。

Examples 8 to 14

This example provides a series of highly heat stable PC materials having the formulation given in Table 3.

TABLE 3 formulations (parts) of examples 8 to 14

Components	Example 1	Example 8	Example 9	Example 10	Example 11	Example 12	Example 13	Example 14
									Polycarbonate 1#	89	94	60	65	90	/	89	89
Polycarbonate 2#	/	/	/	/	/	89	/	/
									Glass fiber 1#	10	5	40	35	8	10	/	10
Glass fiber 2#	/	/	/	/	/	/	10	/
									Aromatic hydrocarbon derivative 1#	0.6	1.8	0.06	0.3	1.2	0.6	0.6	0.6
Aromatic hydrocarbon derivative 2#	0.4	1.2	0.04	0.2	0.8	0.4	0.4	0.4
									Antioxidant agent	/	/	/	/	/	/	/	0.2

。

The properties of the high heat-resistant and stable PC materials of the respective examples and comparative examples were measured in accordance with the above-mentioned methods, and the results are shown in Table 4.

TABLE 4 results of Performance test of each example and comparative example

As can be seen from table 4, the PC materials provided in the examples of the present invention and the comparative examples can be visually evaluated by the specific evaluation method provided by the present invention, and the high heat-resistant and stable PC materials provided in the examples of the present invention have good heat processing stability, can significantly reduce appearance defects, and maintain good performance and appearance under high-temperature and high-humidity storage conditions. The PC material (examples 1 to 3) which selects the aromatic hydrocarbon derivative with a specific proportion and a specific group has more excellent performance, and is superior to the PC material (examples 4 to 7) which only selects a single aromatic hydrocarbon derivative; the polycarbonate (examples 1 and 12) and the filler (examples 1 and 13) have certain influence on the properties of the PC material; the PC material with added antioxidant (as in example 14) is liable to develop stickiness under long-term use conditions, but the aromatic hydrocarbon derivative has a good prolonged stabilizing effect, so that only relatively dispersed and relatively short off-color lumps appear on the surface of the article, and the level of material defects remains within an acceptable range (within an acceptable range at grade. ltoreq.3). The PC material without the stabilizer (as comparative example 1) has poor stability, and carbon free radicals, peroxy radicals ROOR and hydroperoxyl radical ROOH are easily generated in the thermal processing process, so that isopropylidene is broken to generate small molecular substances, and the macroscopic expression shows that discoloration and material flowering appear; the PC material added with the prior stabilizer (such as comparative example 2) can reduce the thermal decomposition of the material to a certain degree, but the improvement of the material cost is not obvious, and the long-term performance of high temperature and high humidity is deteriorated to a certain degree.

It will be appreciated by those of ordinary skill in the art that the examples provided herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited examples and embodiments. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.

Claims

1. A high heat-resistant stable PC material is characterized by comprising the following components in parts by weight:

60-94 parts of polycarbonate;

0-40 parts of a filler;

0.1-3 parts of aromatic hydrocarbon derivatives;

0-10 parts of other functional additives;

2. The high thermostable PC material according to claim 1, characterized in that it comprises the following components in parts by weight:

65-90 parts of polycarbonate;

5-35 parts of a filler;

0.5-2 parts of aromatic hydrocarbon derivatives;

0.1-2 parts of other functional additives.

3. The PC material with high heat resistance and stability according to claim 1, wherein the polycarbonate is bisphenol A polycarbonate and has a molecular weight of 10000-40000.

4. The high heat resistance and stability PC material according to claim 1, wherein the filler is one or more of glass fiber, talcum powder, wollastonite or whisker.

5. The highly thermostable and stable PC material according to claim 1, wherein the aromatic hydrocarbon derivative contains one or more of the following groups: hydroxylamine groups, bisphenol monoacrylate groups, ortho-propenyl-substituted phenol groups, phosphoric acid groups or benzofuranone groups.

6. The highly heat-resistant and stable PC material according to claim 1, wherein the aromatic hydrocarbon derivative is one or more of organic phosphites, alkylated monophenols or polyphenols, alkylated reaction products of polyphenols and dienes, butylated reaction products of p-cresol or dicyclopentadiene, alkylated hydroquinones, alkylene-bisphenols, benzyl compounds, polyol esters, benzotriazoles or benzophenones.

7. The PC material with high heat resistance and stability as claimed in claim 1, wherein the aromatic hydrocarbon derivative has a light transmittance of not less than 95.0% at 450-500 nm.

8. The high heat resistance and stability PC material according to claim 1, wherein the other functional auxiliary agent is one or more of a stabilizer, a flame retardant, an anti-dripping agent, a lubricant, a mold release agent, a plasticizer, an antistatic agent, an antibacterial agent, an antioxidant or a colorant.

9. The method for preparing the PC material with high heat resistance and stability as claimed in any one of claims 1 to 8, characterized by comprising the following steps: and uniformly mixing polycarbonate, filler, aromatic hydrocarbon derivative and other functional additives, melting, and performing injection molding to obtain the high-heat-resistance stable PC material.

10. Use of the highly thermostable and stable PC material according to any one of claims 1 to 8 for the production of large-sized articles.