CN112375300A

CN112375300A - Liquid low-wall-built-up conductive polypropylene composite material and preparation method thereof

Info

Publication number: CN112375300A
Application number: CN202011288796.7A
Authority: CN
Inventors: 肖浩; 李�杰; 周良霄; 蔡青; 周文
Original assignee: Shanghai Pret Bantai Material Technology Co ltd
Current assignee: Shanghai Pret Bantai Material Technology Co ltd
Priority date: 2020-11-17
Filing date: 2020-11-17
Publication date: 2021-02-19
Anticipated expiration: 2040-11-17
Also published as: CN112375300B

Abstract

The invention discloses a liquid low-wall-built-up conductive polypropylene composite material and a preparation method thereof, wherein the polypropylene composite material comprises the following raw material components in parts by weight: polypropylene resin: 70-87%; irradiation of conductive carbon black: 14 to 26 percent; elastomer: 2 to 8 percent; lubricant: 0.2-1%; antioxidant: 0.1 to 1 percent; nucleating agent: 0.1 to 0.3 percent. The invention also discloses a preparation method of the liquid low wall-hanging conductive polypropylene composite material, which can improve the number of active functional groups on the surface of the conductive carbon black by irradiating the conductive carbon black through gamma rays, thereby effectively improving the combination effect of the conductive carbon black and the PP material, ensuring that the surface of a part prepared from the conductive PP material is not easy to fall off the conductive carbon black, and the part is formed by injection molding, has more uniform wall hanging property and less liquid wall hanging property when tested by serum and clear water.

Description

Liquid low-wall-built-up conductive polypropylene composite material and preparation method thereof

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a liquid low-wall-built conductive polypropylene composite material and a preparation method thereof.

Background

The polypropylene has the advantages of no toxicity, no smell, low density, excellent moisture absorption resistance, excellent acid and alkali corrosion resistance, excellent solubility resistance and the like, and is widely applied to the aspects of automobile industry, household appliances, pipe materials, mechanical part manufacturing and the like as a common plastic. However, polypropylene has extremely poor conductivity and is easy to generate electrostatic hazard in the use process, so that the application of polypropylene in the fields of electronics, medical treatment and the like is limited.

In order to reduce the resistance of polypropylene and improve the conductivity of polypropylene, a great deal of research is carried out on a polypropylene blending system added with carbon fibers, conductive carbon black, carbon nanotubes and graphene at home and abroad, and mainly the research is carried out on the dispersibility of a conductive filler in polypropylene, for example, in patent CN1300239C, glass fibers, epoxy resin and conductive carbon black are uniformly dispersed in polypropylene to obtain conductive composite material polypropylene with good conductivity; in order to achieve better dispersion, Chinese patent CN11621088A adds conductive carbon black master batch into polypropylene material to obtain uniformly dispersed conductive composite material; chinese patent CN108866669B carries out surface modification on carbon nano-tubes, thereby better dispersing in polypropylene materials to prepare conductive composite materials with uniform conductivity.

However, in numerous patents at home and abroad, the study on the liquid wall hanging property of the conductive polypropylene composite material is not basically involved, along with the rapid development of modern inspection and analysis, the chemical and biological technologies also require to be more and more accurate and simple, in the prior art, operations such as accurate sampling, liquid transferring, uniform mixing and the like of a liquid sample are carried out by adopting a liquid transferring device, a liquid transferring suction head is used as a consumable material matched with the liquid transferring device, the safety and the accuracy of sample sucking and sample sorting are ensured, the liquid transferring suction head is required to have conductivity, and the wall hanging of the liquid sample in the suction head is less, so that the study work is necessarily further strengthened, and the polypropylene composite material with less conductivity and liquid wall hanging property is developed.

Disclosure of Invention

The invention aims to provide a liquid low-wall-built conductive polypropylene composite material and a preparation method thereof.

The purpose of the invention can be realized by the following technical scheme:

a liquid low-wall-hanging conductive polypropylene composite material is composed of the following raw materials in percentage by weight:

polypropylene resin: 70-88%;

irradiation of conductive carbon black: 14 to 26 percent;

elastomer: 2 to 8 percent;

lubricant: 0.2-1%;

antioxidant: 0.1 to 1 percent;

nucleating agent: 0.1 to 0.3 percent;

the preparation method of the irradiation conductive carbon black comprises the following steps:

placing the irradiation conductive carbon black in gamma rays for irradiation, wherein the irradiation conditions are as follows: the radiance is 3-10KGy/h, and the irradiation time is 4-7 min.

As a further scheme of the invention, the irradiation conditions in the preparation process of the irradiation conductive carbon black are as follows: the radiance is 3KGy/h, and the irradiation time is 5 min.

As a further scheme of the invention, the pretreatment method of the irradiation conductive carbon black comprises the following steps: uniformly mixing conductive carbon black and EMA according to a certain weight ratio.

As a further aspect of the invention, the weight ratio of conductive carbon black to EMA is 99: 1.

As a further scheme of the invention, the polypropylene is one or a mixture of more of polypropylene copolymer and polypropylene homopolymer, and the melt index of the polypropylene is 30-50g/10 min.

In a further embodiment of the present invention, the elastomers POE-g-MAH, PE-g-MAH, EPDM-g-MAH and SEBS-g-MAH are selected from one or a combination of at least two of these elastomers at any ratio.

As a further scheme of the invention, the lubricant is one or any combination of at least two of stearic acid amide, paraffin wax, polyethylene wax or silicone master batch.

As a further scheme of the invention, the antioxidant is prepared by compounding an antioxidant 1010 and an antioxidant 168 according to the weight ratio of 1: 2.

As a further scheme of the invention, the antioxidant is a high-temperature-resistant antioxidant H161.

The preparation method of the liquid low-wall-built-up conductive polypropylene composite material specifically comprises the following steps:

s1, weighing the raw materials according to the weight ratio;

s2, putting the raw materials except the irradiation conductive carbon black into a high-speed mixer for dry mixing for 3-5 min;

s3, feeding the substance obtained in the step S2 into a double-screw extruder through a main feeder, and adding irradiation conductive carbon black into a side feeding port of the double-screw extruder;

s4, extruding, cooling, granulating and drying the substance obtained in the step S3, wherein the rotating speed of the double-screw extruder is 300-400 r.p.m.; the temperature of each section of the double-screw extruder is between 200 ℃ and 250 ℃.

The invention has the beneficial effects that:

according to the preparation method of the liquid low-wall-built conductive polypropylene composite material, the conductive carbon black is subjected to irradiation treatment through gamma rays, so that the number of active functional groups on the surface of the conductive carbon black can be increased, particularly the number of hydroxyl functional groups is remarkably increased, the combination effect of the conductive carbon black and a PP material can be effectively improved, the EMA can be grafted on the surface of the conductive carbon black by mixing the conductive carbon black and the EMA and then performing irradiation treatment, the number of the active groups on the surface of the conductive carbon black is further increased, the combination effect of the conductive carbon black and the PP material is also effectively improved, the conductive carbon black is not easy to fall off from the surface of a part prepared from the conductive PP material, the part is formed by injection molding, the wall-built property is more uniform when the part is tested by serum and clear water, and the wall-built-up property of the liquid is less.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The technical features of the present invention will be further described with reference to the following embodiments.

In the embodiment of the invention, the polypropylene is selected from copolymerized polypropylene with Mobil melt index of 50g/10 min; the conductive carbon black is selected from Czech conductive carbon black ac-80, the EMA is selected from Vertellus ZeMac-E60P, and the blended conductive carbon black is obtained by uniformly mixing the conductive carbon black ac-80 and the ZeMac-E60P according to the mass ratio of 99: 1; irradiating the conductive carbon black by gamma rays (the radiance is 3KGy/h) for 5 minutes; irradiating the blended conductive carbon black by gamma ray (radiance of 3KGy/h) for 5 minutes after the blended conductive carbon black is mixed; the compatilizer is maleic anhydride grafted POE; the lubricant is silicone master batch provided by German Wake; the antioxidant is 1010 and the antioxidant 168 according to the weight ratio of 1:2 compounding or high-temperature antioxidant H161;

example 1:

(1) weighing 81.4% of polypropylene, 3% of maleic anhydride grafted POE, 0.3% of 1010 and 168 compound antioxidant and 0.3% of lubricant according to the weight ratio.

(2) The raw materials are put into a high-speed mixer to be blended for 5 minutes and then are added from the main feeding port of a double-screw extruder.

(3) Adding 15 wt% of irradiation blending conductive carbon black into a feeding port at the double screw side.

(4) The materials are extruded and granulated by a double-screw extruder, the temperature from a temperature port to a machine head is 190 ℃, 210 ℃, 220 ℃, 230 ℃, 230 ℃, 230 ℃ and the rotating speed is 380r.p.m, and the mixture is subjected to composite treatment such as shearing, melting and the like in the double-screw extruder.

(5) And (4) extruding, cooling, granulating and drying the substance obtained in the step (4).

Example 2:

(1) weighing 76.4% of polypropylene, 3% of maleic anhydride grafted POE, 0.3% of 1010 and 168 compound antioxidant and 0.3% of lubricant according to the weight ratio.

(3) Adding 20 wt% of irradiation blending conductive carbon black into a feeding port at the double screw side.

Example 3:

(1) weighing 71.4% of polypropylene, 3% of maleic anhydride grafted POE, 0.3% of 1010 and 168 compound antioxidant and 0.3% of lubricant according to the weight ratio.

(3) Adding 25 wt% of irradiation blending conductive carbon black into a feeding port at the double screw side.

Comparative example 1:

(1) weighing 81.4% of polypropylene, 3% of maleic anhydride grafted POE, 0.3% of 1010 and 168 compound antioxidant, 0.3% of lubricant and 0.15% of EVA according to the weight ratio.

(3) 14.85% by weight of irradiated conductive carbon black was added through a feed port on the twin screw side.

Comparative example 2:

(1) weighing 76.4% of polypropylene, 3% of maleic anhydride grafted POE, 0.3% of 1010 and 168 compound antioxidant, 0.3% of lubricant and 0.2% of EVA according to the weight ratio.

(3) The feeding port on the double screw side of the irradiated conductive carbon black with the weight ratio of 19.8 percent is added.

Comparative example 3:

(1) weighing 71.4% of polypropylene, 3% of maleic anhydride grafted POE, 0.3% of 1010 and 168 compound antioxidant, 0.3% of lubricant and 0.25% of EVA according to the weight ratio.

(3) 24.75 wt% of irradiated conductive carbon black was added through a feed port on the twin screw side.

Comparative example 4:

(3) Adding 15 wt% of blended conductive carbon black into a feeding port at the double screw side.

Comparative example 5:

(3) 20 percent of blended conductive carbon black is added into a feeding port at the double screw side.

Comparative example 6:

(3) Adding 25 wt% of blended conductive carbon black into a feeding port at the double screw side.

The materials of examples 1-3 and comparative examples 1-6 above were injection molded into liquid tips and tested for liquid wall build-up using pure water and serum, as measured by the weight of liquid discharged through the tip after the tip was filled with liquid, the greater the weight, the less liquid wall build-up, and the greater the inverse. Each test data is the test data of 200 liquid suction heads, and the maximum value MAX, the minimum value MIN, the average value AV and the variance value CV of the liquid weight are taken as statistical data for comparison.

TABLE 1 50ul pure water tip test data for examples 1-3 and comparative examples 1-6

TABLE 250 ul 10% serum tip test data for examples 1-3 and comparative examples 1-6

As can be seen from tables 1 and 2, the liquid suction heads prepared from the conductive polypropylene composite material modified by the conductive carbon black without irradiation treatment (comparative examples 4-6) have the minimum Average (AV) liquid discharge weight, which means that the liquid wall hanging of the product is the largest in pure water or serum tests, and the CV value is the largest, which means that the liquid discharge amounts of the product are substantially different from each other, and the precision and the stability are poor; in the liquid suction head (comparative examples 1-3) prepared by irradiating the conductive carbon black modified conductive polypropylene composite material, the Average (AV) liquid discharge weight and CV value are both centered, which means that only the irradiation of the conductive carbon black has a certain effect on the wall-hanging property of the composite material; the liquid suction head (examples 1-3) prepared from the irradiated and blended conductive carbon black modified conductive polypropylene composite material has the largest Average (AV) liquid discharge weight, which means that the liquid wall built-up of the product is the smallest and the CV value is the smallest in tests of pure water or serum, which means that the liquid discharge amount is approximately equal, the precision is high and the stability is good; the irradiation of the conductive carbon black and the EVA simultaneously has a synergistic enhancement effect, so that the stability and the accuracy of the liquid suction head prepared by the modified material are the best.

The foregoing is merely exemplary and illustrative of the present invention and various modifications, additions and substitutions may be made by those skilled in the art to the specific embodiments described without departing from the scope of the invention as defined in the following claims.

Claims

1. The liquid low-wall-built-up conductive polypropylene composite material is characterized by comprising the following raw materials in percentage by weight:

polypropylene resin: 70-88%;

irradiation of conductive carbon black: 14 to 26 percent;

elastomer: 2 to 8 percent;

lubricant: 0.2-1%;

antioxidant: 0.1 to 1 percent;

nucleating agent: 0.1 to 0.3 percent;

placing the conductive carbon black in gamma rays for irradiation, wherein the irradiation conditions are as follows: the radiance is 3-10KGy/h, and the irradiation time is 4-7 min.

2. The liquid low wall built-up conductive polypropylene composite material as claimed in claim 1, wherein the irradiation conditions in the preparation process of the irradiation conductive carbon black are as follows: the radiance is 3KGy/h, and the irradiation time is 5 min.

3. The liquid low wall built-up conductive polypropylene composite material as claimed in claim 1, wherein the pretreatment method of the irradiation conductive carbon black comprises the following steps: uniformly mixing conductive carbon black and EMA according to a certain weight ratio.

4. The liquid low wall built-up conductive polypropylene composite material according to claim 3, wherein the weight ratio of the conductive carbon black to the EMA is 99: 1.

5. The liquid low wall built-up conductive polypropylene composite material as claimed in claim 1, wherein the polypropylene is a mixture of one or more of co-polypropylene and homo-polypropylene, and the melt index of the polypropylene is 30-50g/10 min.

6. The liquid low wall built-up conductive polypropylene composite material as claimed in claim 1, wherein the elastomer POE-g-MAH, PE-g-MAH, EPDM-g-MAH and SEBS-g-MAH are combined in any ratio.

7. The liquid low wall built-up conductive polypropylene composite material according to claim 1, wherein the lubricant is one or a combination of at least two of stearic acid amide, paraffin wax, polyethylene wax or silicone master batch at any ratio.

8. The liquid low wall built-up conductive polypropylene composite material as claimed in claim 1, wherein the antioxidant is compounded from antioxidant 1010 and antioxidant 168 in a weight ratio of 1: 2.

9. The liquid low wall built-up conductive polypropylene composite material as claimed in claim 1, wherein the antioxidant is a high temperature antioxidant H161.

10. The preparation method of the liquid low-wall-hanging conductive polypropylene composite material as claimed in claim 1, which comprises the following steps:

s1, weighing the raw materials according to the weight ratio;