WO2022052408A1 - Carbon nanotube master batch, and preparation method therefor and application thereof - Google Patents

Abstract

A carbon nanotube master batch, and a preparation method therefor and an application thereof. The carbon nanotube master batch comprises the following components in parts by weight: 50-80 parts of a PP resin, 10-40 parts of a filler, 3-10 parts of MWCNT, and 0.1-3 parts of an auxiliary agent. The MWCNT is a multi-walled carbon nanotube, and the filler is at least one of talcum powder, calcium carbonate, barium sulfate, and glass fiber. According to the carbon nanotube master batch provided by the present application, by means of the control of the components and the content, a high-dispersion MWCNT master batch can be prepared under ordinary twin-screw extrusion conditions, and the problem that the MWCNT structure is damaged easily due to the fact that a professional apparatus is required in conventional master batch preparation for internal mixing is solved.

Description

A kind of carbon nanotube master batch and its preparation method and application technical field

The invention relates to the field of polymer material modification, in particular to a carbon nanotube master batch and a preparation method and application thereof.

Background technique

As a cost-effective general-purpose plastic, polypropylene (PP) has excellent mechanical properties after toughening and modification, and is easy to form and process, and is widely used in home appliances and automotive products.

Millimeter-wave radars will be widely used in automatic cruise (ACC), collision avoidance system (CA) and lane-change assistance systems in future automotive automated driving technologies, and with the development of technology, 77GHz millimeter-wave radars will be widely industrialized and Replacing 24GHz millimeter-wave radar has become the mainstream of automotive millimeter-wave radar applications. In this case, the anti-jamming of radar is particularly important.

Due to the low density of multi-walled carbon nanotubes (MWCNTs), it is difficult to disperse. When used to prepare conductive polypropylene compositions, MWCNTs are not easy to disperse and easily cause dust pollution in the production process. In order to use the high shear method of internal mixing, professional equipment technology and professional formula design are required at the same time, and the formula design freedom is low and cumbersome, so an efficient, convenient and cost-saving preparation method of MWCNT masterbatch is required. To improve the dispersion of MWCNTs in the matrix resin and reduce dust pollution in the production process. At the same time, since polypropylene is more difficult to achieve electrical conductivity than other polar resins, there are relatively few reports on conductive polypropylene products on the market at present, and the conventional solution to achieve material conductivity in the polypropylene system will It encounters the problems of extremely high addition amount, unstable production and fluctuation of material conductivity. Therefore, it is still necessary to develop a simple and feasible method for preparing conductive polypropylene materials in the field, which is suitable for automobile interior and exterior trim parts with electromagnetic shielding requirements. .

SUMMARY OF THE INVENTION

Based on this, the purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a carbon nanotube master batch.

In order to achieve the above purpose, the technical scheme adopted in the present invention is: a carbon nanotube master batch, comprising the following components by weight: 50-80 parts of PP resin, 10-40 parts of filler, 3-10 parts of MWCNT and auxiliary agent 0.1 to 3 parts; the filler is at least one of talc, calcium carbonate, barium sulfate, and glass fiber.

Preferably, the carbon nanotube masterbatch includes the following components in parts by weight: 50-80 parts of PP resin, 20-30 parts of filler, 5-8 parts of MWCNT and 0.1-3 parts of auxiliary.

Preferably, at least one of the following (a) to (c):

(a) the PP resin is at least one of homopolypropylene and copolymerized polypropylene, and the melt mass flow rate of the PP resin at 230° C. under a load of 2.16Kg is 1-100g/10min;

(b) the MWCNT is a multi-walled carbon nanotube, the diameter of the MWCNT is 8-60 nm, and the length of the MWCNT is 2-100 μm;

(c) The auxiliary agent is one or more of antioxidants, light stabilizers and lubricants.

At the same time, the present invention also provides a method for preparing the carbon nanotube master batch, which comprises the following steps: mixing PP resin, MWCNT, filler and auxiliary agent uniformly, then adding it into a twin-screw extruder, and performing melt-kneading. , extruding and granulating to obtain carbon nanotube master batches; wherein, the temperature of melting and kneading is 200-210° C., and the screw speed of the twin-screw extruder is 350-450 rpm.

The invention also provides the application of the carbon nanotube master batch in the conductive polypropylene material.

In addition, the present invention also provides a conductive polypropylene material comprising the above-mentioned carbon nanotube master batch, comprising the following components in parts by weight: 20-70 parts of PP resin, 0-30 parts of toughening agent, 0-40 parts of filler, carbon 10-50 parts of nanotube master batch, 10-50 parts of conductive carbon black master batch and 0.1-3 parts of auxiliary agent.

Preferably, in the conductive carbon black masterbatch, the weight percentage of the conductive carbon black is ≥40%, and the oil absorption value of the conductive carbon black is ≥120 m ³ /100g; the measurement standard of the oil absorption value of the conductive carbon black is ASTM D3493 -2016.

Preferably, the conductive polypropylene material comprises the following components by weight: 20-70 parts of PP resin, 0-30 parts of toughening agent, 0-40 parts of filler, 20-40 parts of carbon nanotube masterbatch, conductive 15-35 parts of carbon black masterbatch and 0.1-3 parts of additives.

Preferably, at least one of the following (1) to (4):

(1) The PP resin is at least one of homopolypropylene and copolymerized polypropylene, and the melt mass flow rate of the PP resin at 230°C and a load of 2.16Kg is 1-100g/10min;

(2) the toughening agent is one or more of POE plastic, hydrogenated styrene-butadiene block copolymer (SEBS), and ethylene-propylene-diene rubber (EPDM);

(3) described filler is one or more in talc, calcium carbonate, barium sulfate, glass fiber;

(4) The auxiliary agent is one or more of antioxidants, light stabilizers and lubricants.

More preferably, at least one of the following (a) to (b):

(a) The melt mass flow rate of the toughening agent at 190° C. under a load of 2.16Kg is 0.1-20g/10min;

(b) The particle size of the filler is 1000-5000 mesh.

Preferably, the antioxidant is a hindered phenolic and/or phosphite antioxidant, specifically one or a mixture of two or more of 1010, 1076, 3114, 168, and PEP-36;

The light stabilizer is a hindered amine light stabilizer, specifically one or a mixture of two or more of UV-3808PP5, LA-402XP, and LA-402AF;

The lubricant is one or a mixture of two or more of silicones, esters, amides, polyethylenes, stearic acids, fatty acids and esters.

Further, the present invention also provides a preparation method of the conductive polypropylene material, the method is as follows: mixing PP resin, toughening agent, filler, carbon nanotube master batch, conductive carbon black master batch and auxiliary agent evenly Then, it is added to the twin-screw extruder, melt-kneaded, extruded and pelletized to obtain conductive polypropylene material; wherein, the melt-kneading temperature is 200-210°C, and the screw speed of the twin-screw extruder is 350-450 rpm /Minute.

In addition, the present invention also discloses the application of the conductive polypropylene material in the interior and exterior trim parts of automobiles that require electromagnetic shielding.

Compared with the prior art, the beneficial effects of the present invention are:

1) The carbon nanotube masterbatch of this application, through the control of each component and content, realizes the preparation of MWCNT masterbatch with a high degree of dispersion under ordinary twin-screw extrusion conditions, and gets rid of the traditional masterbatch preparation that requires professional use. Banburying with equipment can easily lead to the problem of damage to the MWCNT structure. At the same time, the MWCNT masterbatch produced by extrusion has a higher degree of freedom in formula design and is easy to operate, so it does not need to be limited by the limitations of commercially available MWCNT masterbatch products.

2) The production method of the prepared MWCNT masterbatch is simple and convenient to implement, has cost advantages, and has a high degree of design freedom.

3) Compared with the conventional polypropylene conductive scheme, the prepared conductive polypropylene composition has a convenient production method, a lower content of conductive fillers to be added, and a higher conductivity of the material, and has the advantages of simplicity, low cost, and improved performance. The advantage of high conductivity.

4) The prepared conductive polypropylene composition has very high conductivity, and is suitable for use as an EMI material, for automotive interior and exterior trim parts with EMI characteristic requirements and other applications with EMI requirements.

detailed description

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below with reference to specific embodiments. The following embodiments are only typical examples of the present invention, and the protection scope of the present invention is not limited thereto. In the following examples and comparative examples, the test method for electrical conductivity is: the surface resistance of the material is tested according to ASTM D-4496 and D-257 standards; the test standard for impact strength is ISO 527; the test for flexural modulus is expressed as ISO 178 .

The main representative materials used in the examples and comparative examples are as follows:

PP resin: copolymerized polypropylene, the melt mass flow rate at 230°C and 2.16Kg load is 40g/10min, Sinopec Maoming;

MWCNT: diameter of 8-15nm, length of 10-70um, LG Chem;

Filler 1 (talc): the particle size is 3000 mesh, Beihai Group;

Filler 2 (talcum powder): particle fineness is 325 mesh, Beihai Group

Toughening agent 1 (POE): The melt mass flow rate at 190°C and 2.16Kg load is 1.2g/10min, Dow Chemical;

Toughening agent 2 (POE): the melt mass flow rate at 190°C and 2.16Kg load is 30g/10min, Dow Chemical;

Conductive carbon black masterbatch 1: The weight percentage of conductive carbon black is 50%, the oil absorption value of conductive carbon black is 150m ³ /100g [the measurement standard is ASTM D3493-2016], Chengrong, Taiwan;

Conductive carbon black masterbatch 2: The weight percentage of conductive carbon black is 50%, the oil absorption value of conductive carbon black is 110m ³ /100g [the measurement standard is ASTM D3493-2016], Chengrong, Taiwan;

Auxiliaries (all are commercially available):

Lubricant (Zinc Stearate)

Antioxidants (1010/168)

Light Stabilizer (UV-3808)

The preparation method of carbon nanotube masterbatch is as follows:

Take PP resin, MWCNT, fillers and additives and mix them evenly, add them into a twin-screw extruder, and carry out melt-kneading. , to obtain carbon nanotube masterbatches.

The preparation method of the conductive polypropylene material is as follows:

Mix the PP resin, toughening agent, mineral filler, carbon nanotube masterbatch, conductive carbon black masterbatch and additives evenly and then add it to the twin-screw extruder for melting and kneading. The melting and kneading temperature is 200～210℃ , the rotating speed of the screw is 350-450 rpm, extruding and granulating to obtain conductive polypropylene material.

The application sets Examples 1 to 11 and Comparative Examples 1 to 5, and the contents of each component of the carbon nanotube masterbatch 1# to 5# are shown in Table 1; the contents of each component of the conductive polypropylene material in Examples 1 to 11 and The properties are shown in Table 2; the contents and properties of each component of the conductive polypropylene materials in Comparative Examples 1 to 5 are shown in Table 3.

Table 1 Content of each component of carbon nanotube masterbatch 1#～5#

Table 2 Contents and properties of each component of the conductive polypropylene material in Examples 1 to 11

Table 3 Contents and properties of conductive polypropylene materials in Comparative Examples 1 to 5

project	Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
PP resin	50	50	50	30
talcum powder				15
POE				10
Conductive carbon black masterbatch	25	25		35
MWCNTs		2
Carbon Nanotube Masterbatch 1#			25
Carbon nanotube masterbatch 5#				20
Antioxidant	0.4	0.4	0.4	0.4
light stabilizer	0.4	0.4	0.4	0.4
Zinc stearate	0.3	0.3	0.3	0.3
Surface resistance (Ω/sq)	>1.0E+12	5.62E+05	4.81E+06	4.75E+08
Impact Strength (KJ/m 2 )	45.78	34.26	45.12	28.54
Flexural modulus (MPa)	1040	1126	1158	1246

As can be seen from Table 2, the electrical conductivity test results of the conductive polypropylene materials obtained in Examples 1 to 11 of the present invention are all at the level of 10 ⁴ -10 ² Ω/sq, indicating that the self-made MWCNT masterbatch in this patent and the conductive carbon The scheme of mixing black masterbatch can greatly reduce the total amount of conductive filler added in the system, and at the same time achieve very good material conductivity.

Comparing Examples 2 to 5, it can be seen that in Examples 3 and 4, 20 to 40 parts of carbon nanotube masterbatches, 15 to 35 parts of conductive carbon black masterbatches, and 10 parts of carbon nanotube masterbatches in Examples 2 and 5 ～50 parts, 10～50 parts of conductive carbon black masterbatch, the conductivity, impact strength, and flexural modulus in Examples 3 and 4 are better than those in Examples 2 and 5, and at the same time, Example 2 uses a large amount of MWCNT masterbatch. , although the final product can achieve good electrical conductivity, but its product cost is much higher than that of Examples 3 and 4; while Example 5 has a very high proportion of conductive carbon black, although the product has high conductivity, it is often produced The process is prone to problems.

Comparing Examples 3 and 6 to 8, it can be seen that in the carbon nanotube master batches in Examples 3 and 6, 20 to 30 parts of fillers and 5 to 8 parts of MWCNTs; the carbon nanotube master batches in Examples 7 and 8 Among them, 10-40 parts of filler and 3-10 parts of MWCNT; the impact strength and flexural modulus in Examples 3 and 6 are better than those in Examples 7 and 8, and the electrical conductivity in Examples 3 and 6 are better than those in Example 8, Although Example 7 has high electrical conductivity, it does not have a very good actual production capacity. This is because: the carbon nanotube masterbatch 3# contains very high talc and MWCNT ratios, resulting in Production becomes less stable, which is not conducive to the improvement of material conductivity.

Comparing Example 1 with Comparative Examples 1 to 3, it can be seen that Comparative Examples 1 and 3 only contain at least one of conductive carbon black masterbatch and carbon nanotube masterbatch, and Comparative Example 2 directly uses MWCNT powder and conductive The carbon black masterbatch is compounded (25 parts of MWCNT masterbatch 1# contains 2 parts of active ingredient MWCNT).

Comparing Comparative Example 4 with Example 6, it can be seen that the carbon nanotube masterbatch in Comparative Example 4 does not contain filler, and its electrical conductivity, impact performance and flexural modulus are all inferior to those of Example 6.

Comparing Example 3 with Example 9, it can be seen that the particle size of the filler in Example 9 is less than 1000 mesh, and its electrical conductivity, impact performance, and flexural modulus are all worse than those of Example 3; compare Example 3 with Example 10 It can be seen that the melt mass flow rate in Example 10 is greater than 20g/10min, and its electrical conductivity, impact performance, and flexural modulus are all worse than those in Example 3; Conductive carbon black masterbatch, the oil absorption value of conductive carbon black is less than 120m ³ /100g, and its electrical conductivity, impact performance, and flexural modulus are all inferior to those of Example 3.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that, The technical solutions of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims (11)

1. A carbon nanotube master batch is characterized in that it comprises the following components in parts by weight: 50-80 parts of PP resin, 10-40 parts of filler, 3-10 parts of MWCNT and 0.1-3 parts of auxiliary; Wall carbon nanotubes, the filler is at least one of talc, calcium carbonate, barium sulfate and glass fiber.
2. The carbon nanotube master batch according to claim 1 is characterized in that, it comprises the following components in parts by weight: 50-80 parts of PP resin, 20-30 parts of filler, 5-8 parts of MWCNT and 0.1-3 parts of auxiliary agent.
3. The carbon nanotube master batch according to claim 1 or 2, characterized in that, at least one of the following (a) to (c):

   (a) the PP resin is at least one of homopolypropylene and copolymerized polypropylene, and the melt mass flow rate of the PP resin at 230° C. under a load of 2.16Kg is 1-100g/10min;

   (b) the diameter of the MWCNT is 8-60 nm, and the length of the MWCNT is 2-100 μm;

   (c) The auxiliary agent is one or more of antioxidants, light stabilizers and lubricants.
4. The method for preparing carbon nanotube master batches according to any one of claims 1 to 3, wherein the method comprises the following steps: mixing PP resin, MWCNT, fillers and auxiliary agents uniformly and then adding them to a twin-screw extruder , carry out melt-kneading and extrusion granulation to obtain carbon nanotube master batches; wherein, the temperature of melt-kneading is 200-210°C, and the screw speed of the twin-screw extruder is 350-450 rpm.
5. A conductive polypropylene material comprising the carbon nanotube master batch according to any one of claims 1 to 3, characterized in that it comprises the following components by weight: 20 to 70 parts of PP resin, and 0 to 30 parts of toughening agent , 0 to 40 parts of filler, 10 to 50 parts of carbon nanotube master batch, 10 to 50 parts of conductive carbon black master batch and 0.1 to 3 parts of auxiliary.
6. The conductive polypropylene material according to claim 5, wherein, in the conductive carbon black masterbatch, the weight percentage of the conductive carbon black is ≥40%, and the oil absorption value of the conductive carbon black is ≥120 m ³ /100g; The measurement standard of the oil absorption value of the conductive carbon black is ASTM D3493-2016.
7. The conductive polypropylene material according to claim 5, characterized in that it comprises the following components in parts by weight: 20-70 parts of PP resin, 0-30 parts of toughening agent, 0-40 parts of filler, and 20 parts of carbon nanotube masterbatch. ~40 parts, 15-35 parts of conductive carbon black masterbatch and 0.1-3 parts of additives.
8. The conductive polypropylene material according to claim 5, wherein at least one of the following (1) to (4):

   (1) The PP resin is at least one of homopolypropylene and copolymerized polypropylene, and the melt mass flow rate of the PP resin at 230° C. under a load of 2.16Kg is 1-100g/10min;

   (2) described toughening agent is one or more in POE plastic, hydrogenated styrene-butadiene block copolymer, EPDM rubber;

   (3) described filler is one or more in talc, calcium carbonate, barium sulfate, glass fiber;

   (4) The auxiliary agent is one or more of antioxidants, light stabilizers and lubricants.
9. The conductive polypropylene material according to claim 8, wherein at least one of the following (a) to (b):

   (a) The melt mass flow rate of the toughening agent at 190° C. under a load of 2.16Kg is 0.1-20g/10min;

   (b) The particle size of the filler is 1000-5000 mesh.
10. The preparation method of the conductive polypropylene material according to any one of claims 6 to 9, wherein the method comprises: combining PP resin, toughening agent, filler, carbon nanotube masterbatch, conductive carbon black masterbatch and After the additives are evenly mixed, they are added to the twin-screw extruder, melt-kneaded, extruded and granulated to obtain conductive polypropylene material; wherein, the melt-kneading temperature is 200-210°C, and the screw speed of the twin-screw extruder is 350～450 rpm.
11. The application of the conductive polypropylene material according to any one of claims 6 to 9 in automobile interior and exterior trim parts with electromagnetic shielding requirements.