CN115449209A

CN115449209A - Abnormal sound prevention PC/ABS material with low linear expansion coefficient and preparation method thereof

Info

Publication number: CN115449209A
Application number: CN202211276922.6A
Authority: CN
Inventors: 王莉
Original assignee: Shanghai Kumho Sunny Plastics Co Ltd
Current assignee: Shanghai Kumho Sunny Plastics Co Ltd
Priority date: 2022-10-18
Filing date: 2022-10-18
Publication date: 2022-12-09

Abstract

The invention relates to the technical field of high polymer materials, in particular to an abnormal sound prevention PC/ABS material with low linear expansion coefficient and a preparation method thereof, wherein the abnormal sound prevention PC/ABS material comprises the following components in percentage by weight: 50-60% of PC resin; 5-10% of ABS rubber powder; 10% of talcum powder; 5-15% of abnormal sound prevention additive; 0.1 to 1 percent of antioxidant; 0.1-1% of a lubricant; ester exchange inhibitor 0.1-1%; the balance of SAN resin; the sum of the weight percentages of the components is 100 percent; wherein the abnormal sound preventing additive adopts a modified vinyl polymer with the relative molecular weight of 10000-40000. Compared with the prior art, the invention solves the problems that the abnormal sound prevention PC/ABS material in the prior art has higher linear expansion coefficient, is easy to expand with heat and contract with cold, and further causes material cracking and equipment damage.

Description

Abnormal sound prevention PC/ABS material with low linear expansion coefficient and preparation method thereof

Technical Field

The invention relates to the technical field of high polymer materials, in particular to an abnormal sound prevention PC/ABS material with a low linear expansion coefficient and a preparation method thereof.

Background

In recent years, the abnormal sound preventing material has been receiving increased attention mainly because it can solve the pain of people in abnormal sound such as abnormal sound of an air conditioner, abnormal sound of a washing machine, various abnormal sounds occurring in a fan and an automobile, which are frequently occurred in life.

As for PC/ABS materials, the PC/ABS materials can meet the requirements of automotive interior on the materials due to the excellent heat resistance, good toughness and other properties, and are mainly used in automotive interiors. Along with the popularization and application of new energy vehicles, the noise of an engine in the vehicle internal environment is smaller and smaller, the requirements of people on vehicle interior decorations are higher and higher, particularly in the aspect of new energy vehicles, if the interior decorations have abnormal sound, the interior decorations can be obviously perceived, bad experiences are brought to drivers and passengers, the bad feelings of the drivers can influence the attention, and then traffic accidents are caused. In the automotive interior, the positions such as a panel, a door plate, a handrail box, a safety belt and the like can generate abnormal sound due to infirm or loose installation, a comfortable driving and riding environment is provided for overcoming the abnormal sound, and the requirement of people on the interior is higher and higher.

Since the abnormal sound prevention material can solve the pain of consumers, the abnormal sound prevention material is more and more concerned by host computer factories, and a plurality of host computer factories begin to introduce the material with special functions at present. With the increasing use of the abnormal sound preventing materials, the requirements of the automobile factories on the materials are higher, and the materials are not only required to have the abnormal sound preventing effect, but also required to meet the requirements of other functions. Such as: at present, the requirements of people on the individuation and the modernization of the automobile interior are higher and higher, the automobile interior display screen slowly requires double display screens and three display screens from the original single display screen, and the requirements of the display screens are higher and higher, so that the requirements on the plastic frame and the rear cover material of the display screen are also higher. Because the display screen is generally glass material, its dimensional stability is better under the high low temperature change condition, and to plastics frame and backshell, it is great that it receives the temperature influence, and expend with heat and contract with cold is more obvious, compares in glass material, and plastics material's linear expansion coefficient is great, consequently easily when high low temperature experiment or temperature change are great, appears plastics frame fracture or glass display screen and is crowded phenomenon such as bits of broken glass, not only causes the product to damage, still can harm user safety in utilization.

Therefore, a material which has the abnormal sound prevention function, can solve the problem of abnormal sound generated by friction and has a low linear expansion coefficient is needed, and the requirements of experiments and actual use are further met.

Disclosure of Invention

The invention aims to solve at least one of the problems, and provides an abnormal sound prevention PC/ABS material with a low linear expansion coefficient and a preparation method thereof, so as to solve the problems that the abnormal sound prevention PC/ABS material in the prior art has a high linear expansion coefficient, is easy to expand with heat and contract with cold, and further causes material cracking and equipment damage, and realize that the PC/ABS material has a low linear expansion coefficient on the basis of abnormal sound prevention.

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

the invention discloses a low-linear-expansion-coefficient abnormal-sound-prevention PC/ABS material, which comprises the following components in percentage by weight:

the sum of the weight percentages of the components is 100 percent;

wherein the abnormal sound preventing additive adopts a modified vinyl polymer with the relative molecular weight of 10000-40000.

The abnormal sound preventing additive is a modified vinyl polymer which has good compatibility with a system and can also play a role in preventing abnormal sound; the abnormal sound preventing effect is mainly due to the effect of polyethylene, the polyethylene has a good self-lubricating effect and good fluidity, and is easy to migrate to the surface of a material in the processing process, so that the effect of reducing the surface friction and reducing the noise is achieved; the modified vinyl polymer is used in view of the compatibility of the anti-abnormal noise additive with other components, such as PC/ABS, talcum powder, inorganic flame retardant, glass fiber and the like.

Preferably, the PC resin adopts bisphenol A polycarbonate with the relative molecular weight of 20000-28000.

Preferably, the PC resin is bisphenol A polycarbonate prepared by a phosgene method and having a relative molecular weight of 20000 to 28000.

The bisphenol A polycarbonate prepared by the phosgene method has low hydroxyl-terminated and carboxyl contents, and the ester exchange reaction between the bisphenol A polycarbonate and talcum powder can be reduced in the processing process of preparing the PC/ABS material, so that the stability of the material is ensured; the relative molecular weight of the selected bisphenol A polycarbonate is limited to 20000-28000, if the bisphenol A polycarbonate with too high relative molecular weight is selected, the flowability is poor, the processability is affected, and the processing is difficult, and if the bisphenol A polycarbonate with too low relative molecular weight is selected, the mechanical property is low, the impact property is reduced, and the requirements on physical properties in various application environments can not be met, such as outdoor charging piles. Therefore, the material ensures that the finally prepared material can have excellent mechanical property and impact resistance by limiting the source and relative molecular weight of the bisphenol A polycarbonate.

Preferably, the rubber content of the ABS rubber powder is 50%. The addition of the ABS rubber powder is mainly used for adjusting the toughness of the system: as talc (mineral) filling decreases the toughness of the system, it is necessary to supplement the toughness by adding glue; meanwhile, the rubber powder (rubber content) cannot be too much, if the ABS rubber powder is added excessively, on one hand, the fluidity of a system is influenced, so that the extrusion granulation in the preparation process and the product shaping are influenced, and on the other hand, the linear expansion coefficient of the material is also influenced, so that the addition amount and the rubber content of the ABS rubber powder need to be controlled, and the toughening is carried out in a proper amount.

Preferably, the mesh number of the talcum powder is 5000 meshes. The talcum powder belongs to mineral powder and inorganic substances and is hardly influenced by temperature, so that the linear expansion coefficient of the material can be reduced by adding the talcum powder, but the adding amount cannot be too high, the toughness of the system can be influenced by adding too high the adding amount, the blanking is influenced, and the phenomena of bridging and the like are easy to occur in the double-screw extrusion process. The abnormal sound prevention PC/ABS material with the low linear expansion coefficient is obtained by combining talcum powder (the talcum powder is an inorganic substance and has a lubricating property and can play a drying effect to a certain extent) with an abnormal sound prevention additive (the talcum powder is easy to migrate to the surface of the material in the processing process and plays an external lubricating effect), and the abnormal sound prevention PC/ABS material can be used as a shell and a back plate of a display screen.

Preferably, the antioxidant is a mixture of a primary antioxidant and a secondary antioxidant; wherein the main antioxidant is selected from one or two of 2, 6-di-tert-butyl-4-methylphenol and octadecyl beta- (3, 5-di-tert-butyl-4-hydroxy-phenyl) propionate; the auxiliary antioxidant is selected from one or more of dilauryl thiodipropionate, distearyl thiodipropionate, tris (2, 4-di-tert-butylphenyl) phosphite, bis (2, 4-di-tert-butyl) quarternary alcohol diphosphite and pentaerythritol diphosphite dioctadecyl ester. By adding the antioxidant, the antioxidant effect of the PC/ABS material can be improved, the aging degradation is delayed, and the antioxidant effect of the material can be effectively improved by adopting the main antioxidant and the auxiliary antioxidant to cooperate with antioxidant.

Preferably, the lubricant is selected from one or more of silane polymer, fatty acid salt, fatty acid amide, stearic acid, butyl stearate, oleamide, ethylene bis stearamide and polyolefin wax. By adding the lubricant, the processing fluidity of the material can be improved, so that the viscosity and the heat loss are reduced in the processing process, and the processing performance of the material is improved.

Preferably, the transesterification inhibitor is sodium dihydrogen phosphate. The addition of the ester exchange inhibitor can be used for complexing residual metal ions in the talcum powder to inhibit the degradation of the talcum powder to the PC resin, but the addition amount is not too large, and too large amount is easy to agglomerate to block the meshes of an extruder.

Preferably, the SAN resin has a relative molecular weight of 120000-130000.

The invention discloses a method for preparing the abnormal sound prevention PC/ABS material with low linear expansion coefficient, which comprises the following preparation steps:

weighing the components except the talcum powder according to the weight percentage, and uniformly mixing; weighing talcum powder according to weight percentage; adding the mixture into a main feeding port of a double-screw extruder, adding talcum powder into a side feeding port of the double-screw extruder, and performing double-screw extrusion granulation to obtain the abnormal-sound-proof PC/ABS material with the low linear expansion coefficient;

wherein the extrusion temperature of the twin-screw extrusion granulation is 210-280 ℃, and the screw rotating speed is 400-600rpm.

In the preparation method, the side feeding of the talcum powder is limited, the retention time of the talcum powder in a double-screw extruder is reduced, the degradation of the talcum powder to PC resin is reduced, and the stability of the material is improved. In addition, certain extrusion temperature and screw rotation speed are limited, if the extrusion temperature is too high, the exchange reaction of the talcum powder and the PC resin is accelerated, and the degradation is accelerated, if the extrusion temperature is too low, the material is difficult to plasticize, and the extrusion processing is difficult; if the screw rotating speed is too high, the shearing action is too large, more heat is generated during extrusion, the material is easy to yellow and change color, if the screw rotating speed is too low, the raw material mixing dispersibility is poor, the speed is too low, the retention time of the talcum powder in the screw is increased, the degradation of the talcum powder to PC resin is increased, and the product service performance is poor.

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

the heat resistance level of the material is determined by the parts of the PC resin in the PC/ABS material system, so that the parts of the PC resin cannot be too low; talcum powder is added to reduce the linear expansion coefficient of the material; the addition of the abnormal noise prevention additive enables the material to have an abnormal noise prevention effect, and meanwhile, the compatibility of the abnormal noise prevention additive and other components in the material is considered, so that the modified vinyl polymer is selected as the abnormal noise prevention additive, the abnormal noise prevention effect is guaranteed, and the compatibility among the components is also guaranteed.

The preparation method is simple and feasible, the production is stable, and the prepared abnormal sound prevention PC/ABS material with low linear expansion coefficient can reach 5-6 multiplied by 10 ^-5 The sound volume of human ears is superior to that of common abnormal sound prevention PC/ABS materials, namely the material meets the requirements of both abnormal sound prevention effect and low linear expansion coefficient effect, and can be applied to the fields of display screens and the like.

Detailed Description

The present invention will be described in detail with reference to specific examples.

The reagents and methods used in the following examples and comparative examples may be those conventionally available from commercial products or those in the prior art, unless otherwise specified.

The following examples and comparative examples used the starting materials:

PC resin: phosgene method bisphenol A polycarbonate, relative molecular weight 23000;

ABS rubber powder: the glue content is 50%;

talc powder: the grain diameter is 5000 meshes;

abnormal sound prevention additive: a modified vinyl polymer;

antioxidant: the mixture of 2, 6-di-tert-butyl-4-methylphenol and thiodipropionic acid distearate is mixed by the mass ratio of 1;

lubricant: butyl stearate;

ester exchange inhibitor: sodium dihydrogen phosphate, powder.

The methods employed for the performance tests in the following examples and comparative examples:

(1) Impact of the gap of the simply supported beam: 23 ℃,4J, using ISO 179: a standard test method for detecting the impact performance of the plastic simply supported beam;

(2) Ash content: adopting ISO 3451-1: plastic ash determination, test conditions: 950 ℃ C

(3) Coefficient of linear expansion: using ISO 11359-2: plastic, thermodynamic analysis; and (3) testing conditions: -40 ℃ to 80 ℃;

(3) Loudness of human ears: the device is assembled, and the principle of the device is that sound generated by motion friction is received by sound receiving equipment, and is converted into a human ear loudness value through software processing, and the human ear loudness value is used for testing the human ear loudness condition of 100mm/min and 200g.

Example 1

A low-linear expansion coefficient and abnormal sound prevention PC/ABS material is prepared by the following steps:

(1) According to the weight percentage, weighing the raw materials according to the component content of the raw materials in the table 1 for later use;

(2) Adding the components weighed in the step (1) except the talcum powder into a mixing barrel and uniformly mixing to obtain a mixture;

(3) And (3) adding the mixture obtained in the step (2) into a double-screw extruder to carry out blanking at main feeding, carrying out blanking at side feeding of talcum powder, carrying out double-screw extrusion granulation, wherein the extrusion temperature is 240 ℃, the screw rotating speed is 500rpm, obtaining a low-linear expansion coefficient and abnormal sound prevention PC/ABS material, then carrying out injection molding to obtain a test sample strip, and carrying out performance test, wherein the test result is shown in table 2.

Example 2

(2) Adding the components weighed in the step (1) except the talcum powder into a mixing barrel to be uniformly mixed to obtain a mixture;

Comparative example 1

(1) According to the weight percentage, all the raw materials are weighed for standby according to the component content of the raw materials in the table 1;

(2) Adding the components weighed in the step (1) into a mixing barrel and uniformly mixing to obtain a mixture;

(3) And (3) adding the mixture obtained in the step (2) into a double-screw extruder, feeding in a main feeding way, extruding and granulating by using double screws, wherein the extrusion temperature is 240 ℃, the rotating speed of the screws is 500rpm, so that the PC/ABS material with low linear expansion coefficient and abnormal sound prevention is obtained, then, injection molding is carried out, so that a test sample strip is prepared, and the performance test is carried out, wherein the test result is shown in table 2.

Comparative example 2

Comparative example 3

(3) And (3) adding the mixture obtained in the step (2) into a double-screw extruder to perform blanking in a main feeding mode, feeding talcum powder in a side feeding mode to perform blanking, performing double-screw extrusion granulation, wherein the extrusion temperature is 240 ℃, and the screw rotating speed is 500rpm, so that a low-linear-expansion-coefficient abnormal-sound-proof PC/ABS material is obtained, then injection molding is performed to obtain a test sample strip, and the performance test is performed, wherein the test result is shown in table 2.

TABLE 1 raw material component contents of examples 1-2 and comparative examples 1-3

Raw material components	Comparative example 1	Comparative example 2	Comparative example 3	Example 1	Example 2
						PC resin	60	60	60	60	60
ABS rubber powder	10	10	10	10	10
						Talcum powder	/	/	10	10	10
SAN resin	28.5	23.5	18.3	13.3	8.3
						Abnormal sound prevention additive	/	5	/	5	10
Antioxidant agent	1	1	1	1	1
						Lubricant agent	0.5	0.5	0.5	0.5	0.5
Ester interchange inhibitor	/	/	0.2	0.2	0.2

Note: in the table, "/" indicates that this component is not contained.

TABLE 2 results of the performance test of examples 1 to 2 and comparative examples 1 to 3

Test item	Comparative example 1	Comparative example 2	Comparative example 3	Example 1	Example 2
						Impact of simply supported beam gap	52kJ/m ²	45kJ/m ²	35kJ/m ²	31kJ/m ²	28kJ/m ²
Ash content	0％	0％	10％	10％	10％
						Coefficient of linear expansion	8.4×10 ^-5 /K	8.5*10 ^-5 /K	5.8*10 ^-5 /K	6.0*10 ^-5 /K	6.0*10 ^-5 /K
Loudness of human ear	54sone	10sone	24sone	9sone	7sone

From the test results, it can be seen that the addition of the abnormal noise preventing additive can effectively achieve the abnormal noise preventing effect by comparing the comparative example 1 with the comparative example 2, and the addition of the abnormal noise preventing additive can influence the impact performance of the material to a certain extent, and the impact is 52kJ/m from the original impact performance ² Reduced to 45kJ/m ² This is mainly because the anti-reverberation additives are not completely compatible with the base material and have a relatively low molecular weight, which affects the impact properties of the material.

The test result shows that compared with the comparative example 1, the comparative example 3 has the advantages that the addition of the talcum powder can reduce the linear expansion coefficient of the material and improve the dimensional stability of the material, and meanwhile, compared with the comparative example 1, the human ear loudness of the material is reduced to a certain extent due to the fact that the talcum powder is an inorganic substance and has lubricating property and can achieve the dryness reducing effect to a certain extent. Compared with the comparative example 3, the abnormal sound prevention effect of the material can be effectively improved by adding the abnormal sound prevention additive on the basis of the system of adding the talcum powder, and meanwhile, the abnormal sound prevention effect is better under the synergistic effect of the talcum powder and the abnormal sound prevention additive compared with that of the comparative example 2.

According to test results, the addition of the talcum powder in the examples and the comparative examples can reduce the linear expansion coefficient of a system, and can improve the abnormal sound prevention property of the material to a certain extent, but the abnormal sound prevention effect is not obvious enough due to the fact that no abnormal sound prevention additive is added, so that the human ear loudness is greatly reduced and the abnormal sound prevention effect is effectively improved due to the fact that a certain amount of the abnormal sound prevention additive is added in the examples 1 and 2. However, when the additive is added in an amount of more than 10 parts, the improvement of the abnormal noise prevention effect is not obvious, and the impact performance of the material is reduced by adding the abnormal noise prevention additive, and the reduction is more obvious when the additive is higher, so that the effect of adding 5 parts is better, and the toughness and the linear expansion coefficient of the material are not large.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make modifications and alterations without departing from the scope of the present invention.

Claims

1. The abnormal sound prevention PC/ABS material with the low linear expansion coefficient is characterized by comprising the following components in percentage by weight:

the sum of the weight percentages of the components is 100 percent;

2. The low coefficient of linear expansion anti-abnormal sound PC/ABS material of claim 1, wherein the PC resin is bisphenol A polycarbonate with a relative molecular weight of 20000-28000.

3. The low coefficient of linear expansion anti-abnormal sound PC/ABS material of claim 2, wherein the PC resin is bisphenol A polycarbonate with a relative molecular weight of 20000-28000 prepared by phosgene method.

4. The abnormal-sound-proof PC/ABS material with low linear expansion coefficient as claimed in claim 1, wherein the rubber content of the ABS rubber powder is 50%.

5. The low coefficient of linear expansion anti-abnormal sound PC/ABS material of claim 1, wherein the talc powder has a mesh size of 5000 mesh.

6. The abnormal sound prevention PC/ABS material with the low linear expansion coefficient as claimed in claim 1, wherein the antioxidant is a mixture of a primary antioxidant and a secondary antioxidant; wherein the main antioxidant is selected from one or two of 2, 6-di-tert-butyl-4-methylphenol and octadecyl beta- (3, 5-di-tert-butyl-4-hydroxy-phenyl) propionate; the auxiliary antioxidant is selected from one or more of dilauryl thiodipropionate, distearyl thiodipropionate, tris (2, 4-di-tert-butylphenyl) phosphite, bis (2, 4-di-tert-butyl) quarternary alcohol diphosphite and pentaerythritol diphosphite dioctadecyl ester.

7. The low coefficient of linear expansion anti-squeal PC/ABS material of claim 1 wherein the lubricant is selected from one or more of silane polymers, fatty acid salts, fatty acid amides, stearic acid, butyl stearate, oleamide, ethylene bis stearamide and polyolefin wax.

8. The low coefficient of linear expansion anti-squeak PC/ABS material of claim 1 wherein the ester exchange inhibitor is sodium dihydrogen phosphate.

9. The abnormal-sound-prevention PC/ABS material with low linear expansion coefficient as claimed in claim 1, wherein SAN resin with a relative molecular weight of 120000-130000 is used as SAN resin.

10. A method for preparing the low coefficient of linear expansion anti-abnormal sound PC/ABS material according to any of claims 1-9, comprising the steps of:

weighing the components except the talcum powder according to the weight percentage, and uniformly mixing; weighing the talcum powder according to the weight percentage; adding the mixture into a main feeding port of a double-screw extruder, adding talcum powder into a side feeding port of the double-screw extruder, and performing double-screw extrusion granulation to obtain the abnormal-sound-proof PC/ABS material with the low linear expansion coefficient;