CN113502051B

CN113502051B - Excellent leakage-resistant ultraviolet laser marking halogen-free flame-retardant polyamide composite material and preparation method thereof

Info

Publication number: CN113502051B
Application number: CN202110866892.3A
Authority: CN
Inventors: 刘政辉
Original assignee: Zhejiang Xinhui New Material Technology Co ltd
Current assignee: Zhejiang Xinhui New Material Technology Co ltd
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2023-05-16
Anticipated expiration: 2041-07-29
Also published as: CN113502051A

Abstract

The application relates to the field of high polymer materials, and in particular discloses a halogen-free flame-retardant polyamide composite material with excellent leakage resistance and ultraviolet laser marking, which comprises the following components: polyamide resin, carbon nano tube composite glass fiber, halogen-free flame retardant, anti-aging agent, laser marking auxiliary agent and lubricant. A preparation method of a halogen-free flame-retardant polyamide composite material with excellent electric leakage resistance and ultraviolet laser marking comprises the following steps: s1, mixing: the preparation method comprises the steps of weighing polyamide resin, carbon nano tube composite glass fiber, halogen-free flame retardant, anti-aging agent, laser marking auxiliary agent and lubricant according to parts by weight, and stirring and mixing uniformly at normal temperature to obtain a prepared material; s2, extruding the prepared material obtained in the step S1 through a double-screw extruder, and granulating to obtain a finished material. By adding the carbon nano tube composite glass fiber, the polyamide composite material has better strength and better flame retardance, and simultaneously maintains excellent leakage resistance.

Description

Excellent leakage-resistant ultraviolet laser marking halogen-free flame-retardant polyamide composite material and preparation method thereof

Technical Field

The application relates to the field of high polymer materials, in particular to a halogen-free flame-retardant polyamide composite material with excellent electric leakage resistance and ultraviolet laser marking and a preparation method thereof.

Background

The polyamide resin is a polycondensation type polymer compound having a-CONH structure in the molecule, and is usually obtained by polycondensation of a dibasic acid and a diamine. The polyamide is an engineering plastic with wide application, and its molecular structure and crystallization make it possess excellent physical and mechanical properties. And polyamide materials are often used as outer materials for making housings of electronic products or wires, so that the flame retardant properties of polyamide are required to be high, and low dielectric constants and dielectric losses are required.

Ultraviolet laser is usually required to perform marking on the outer layer of the shell or the wire of the electronic product, but polyamide is usually poor in marking effect, so that the marking pattern is low in definition or explosion points occur.

Disclosure of Invention

In order to improve the definition of a marking pattern on polyamide, the application provides a halogen-free flame-retardant polyamide composite material with excellent electric leakage resistance and ultraviolet laser marking and a preparation method thereof.

In a first aspect, the present application provides a halogen-free flame retardant polyamide composite material with excellent leakage resistance, ultraviolet laser marking, and adopts the following technical scheme:

a halogen-free flame-retardant polyamide composite material with excellent electric leakage resistance and ultraviolet laser marking comprises the following components in parts by weight:

55-72 parts of polyamide resin;

20-55 parts of carbon nano tube composite glass fiber, wherein the carbon nano tube composite glass fiber is of a structure that a glass layer is coated on the surface of a carbon nano tube;

5-18 parts of halogen-free flame retardant;

0.1-1 part of anti-aging agent;

1-8 parts of a laser marking auxiliary agent;

2-3 parts of lubricant.

By adopting the technical scheme, the polyamide resin is the main component of the polyamide composite material system, and the polyamide has the advantages of no toxicity, light weight, excellent mechanical strength, wear resistance and better corrosion resistance.

The carbon nano tube has the physical properties of high strength and high toughness, has higher ignition point, can obviously improve the flame retardance and strength of the polyamide resin when being added into the polyamide resin, and is difficult to be directly used as a raw material of a low dielectric constant material due to good conductivity.

The carbon nano tube composite glass fiber has the structure that the glass layer is coated on the surface of the carbon nano tube, and the glass layer is used for insulating and isolating the carbon nano tube coating, so that more carbon nano tubes can be added into the polyamide composite material, the strength and the flame retardance of the polyamide composite material can be obviously improved, the polyamide composite material can also keep a lower dielectric constant, and meanwhile, the carbon nano tube composite glass fiber is added, so that the marking effect is better, and the patterns are clear and have no explosion points.

The halogen-free flame retardant is selected, so that the flame retardance of the polyamide composite material is improved, and the environment-friendly effect is achieved.

The aging inhibitor reduces the aging speed of the polyamide composite material and improves the practical durability of the polyamide composite material.

The laser marking auxiliary agent is used for absorbing the energy of ultraviolet laser, is convenient for marking an ultraviolet laser meter, and enables marking patterns to be clearer.

The lubricant improves the processability of the polyamide composite material and helps to release the mold, thereby facilitating the processing of the polyamide composite material.

Optionally, the carbon nanotube composite glass fiber is a multi-wall carbon nanotube composite glass fiber.

By adopting the technical scheme, the multi-wall carbon nano tube has high strength and strong toughness, so that the multi-wall carbon nano tube composite fiber has higher strength and stronger toughness, and the strength and toughness of the polyamide composite material can be better improved.

Optionally, the preparation method of the multi-wall carbon nano tube composite glass fiber comprises the following steps:

s1, cleaning the multi-wall carbon nano tube: baking the multi-wall carbon nano tube for 1-5h at 200-450 ℃;

s2, cladding a glass layer: placing glass powder in a container, heating to melt, adding the multi-wall carbon nano tube obtained in the step S1 into the glass powder in a molten state, stirring and mixing, pressurizing the pressure in the container to the gauge pressure of 1-2kPa, and continuing stirring for 7-16 hours to obtain a mixture; wherein, the mass ratio of the adding amount of the multi-wall carbon nano tube to the glass powder is 1: (3-5);

s3, preparing multi-wall carbon nano tube composite glass fibers: draining the mixture obtained in the step S2 into a high-speed centrifuge, and centrifuging at a rotating speed of 3000-4000r/min to obtain primary fibers; and forming secondary fibers by drawing the primary fibers by high-temperature annular air flow, standing the secondary fibers at room temperature for 8-12h, cooling, cutting, and obtaining the multi-wall carbon nano tube composite glass fibers.

By adopting the technical scheme, the multi-wall carbon nano tube is baked at the temperature of 200-450 ℃ to remove the grease on the surface of the multi-wall carbon nano tube, so that the glass layer is conveniently coated. The glass powder is heated and melted, and the glass powder with low melting point is selected. After the glass powder is melted, the multi-wall carbon nano tube and the glass powder in a melted state are uniformly stirred. And stirring under the pressurized condition continuously to enable the glass powder in a molten state and the multi-wall carbon nano tube to have an intercalation phenomenon, wherein the interface bonding degree of a glass layer in the multi-wall carbon nano tube composite glass fiber formed later and the multi-wall carbon nano tube is high, so that after the glass fiber is cut off, the multi-wall carbon nano tube is exposed at the cut-off surface, the surface of the multi-wall carbon nano tube is still coated with a thin glass layer, the polyamide composite material is kept to be low in conductivity, and the polyamide composite material is kept to be excellent in leakage resistance.

The mass ratio of the adding amount of the multiwall carbon nano tube to the glass powder is 1: (3-5) the glass layer can uniformly coat the multi-wall carbon nano tube while the adding amount of the multi-wall carbon nano tube is larger, so that the strength of the polyamide composite fiber is high, the conductivity is low, and the polyamide composite material keeps excellent leakage resistance.

Optionally, the mixture is subjected to foaming treatment to form a plurality of bubbles in the molten glass frit fluid, and the gas in the bubbles is carbon dioxide or nitrogen.

By adopting the technical scheme, after the foaming treatment, a great amount of bubbles of carbon dioxide or nitrogen are contained in the glass layer, so that the multi-wall carbon nano tube composite glass fiber has the effect of reducing the heat conductivity of the multi-wall carbon nano tube composite glass fiber, and the purposes of heat insulation and flame retardance are achieved. And the glass layer is destroyed after combustion, so that carbon dioxide and nitrogen are released, the concentration of carbon dioxide at the combustion position is improved, and the flame is inhibited to a certain extent.

Optionally, the foaming treatment method is as follows: placing the glass powder in a molten state in a closed container, heating to enable the glass powder to be kept in the molten state, continuously introducing carbon dioxide or nitrogen into the glass powder in the molten state, keeping the surface pressure at 1-2kPa, stirring at the rotating speed of 1000-1500r/min for 5-12h, and stirring at the rotating speed of 40-100r/min for 2-4h to finish foaming treatment.

According to the technical scheme, carbon dioxide or nitrogen is introduced under the pressurized condition, and simultaneously the mixture is stirred at a high speed at a rotating speed of 1000-1500r/min, so that a large number of bubbles appear in the molten glass powder, and then the mixture is stirred at a low speed at a rotating speed of 40-100r/min, so that the bubbles with larger volume are broken, and a large number of small bubbles remain in the mixture, so that the foaming treatment is completed.

Optionally, the laser marking auxiliary agent is one or a combination of more of calcium carbonate, mica powder, talcum powder and titanium dioxide.

By adopting the technical scheme, the calcium carbonate, the mica powder, the talcum powder and the titanium dioxide can absorb laser energy better, thereby improving the definition of pattern printing.

Optionally, the polyamide resin is one or a combination of more than one of nylon 6, nylon 66, nylon 1010 and nylon 610.

By adopting the technical scheme, one or more of nylon 6, nylon 66, nylon 1010 and nylon 610 can be combined with the halogen-free flame retardant, the anti-aging agent, the laser marking auxiliary agent and the lubricant in the application to have better compatibility, and the type of the polyamide resin raw material can be selected according to the required product.

Optionally, the carbon nanotube composite glass fiber is modified by a silane coupling agent, and the modification method comprises the following steps:

s1, raw material preparation: heating the carbon nano tube composite glass fiber to 300-400 ℃ for 1-2h to remove surface impurities; preparing a modifier: preparing a silane coupling agent into a 2.3-3wt% aqueous solution to obtain a modifier;

s2, under the protection of nitrogen, placing the carbon nano tube composite glass fiber in a modifier, heating to 65-75 ℃ under the stirring condition, reacting for 2-5h, and then cleaning the modified carbon nano tube composite glass fiber with ethanol to obtain the modified carbon nano tube composite glass fiber.

By adopting the technical scheme, the carbon nano tube composite glass fiber is modified and then reacts with polyamide, so that the modified carbon nano tube composite glass fiber has good compatibility with polyamide, and is convenient to uniformly distribute in the polyamide; and the interface strength between the modified carbon nano tube composite glass fiber and the polyamide resin is improved, so that the strength enhancement and the flame retardance enhancement effects of the modified carbon nano tube composite glass fiber on the polyamide composite material are more obvious.

In a second aspect, the present application provides a preparation method of a halogen-free flame retardant polyamide composite material with excellent leakage resistance and ultraviolet laser marking, which adopts the following technical scheme:

the preparation method of the halogen-free flame-retardant polyamide composite material with excellent electric leakage resistance and ultraviolet laser marking is characterized by comprising the following steps:

s1, mixing: weighing 55-72 parts of polyamide resin according to parts by weight; 3-5 parts of carbon nano tube composite glass fiber, 5-18 parts of halogen-free flame retardant, 0.1-1 part of anti-aging agent, 1-8 parts of laser marking auxiliary agent and 2-3 parts of lubricant are stirred and mixed uniformly at normal temperature to obtain a prepared material;

s2, adding the prepared material obtained in the step S1 into a double-screw extruder for extrusion, wherein the rotation speed of a main machine of the double-screw extruder is 500-600rpm, the extrusion temperature is 200-230 ℃, and granulating after extrusion to obtain a finished material.

By adopting the technical scheme, the preparation is carried out by adopting a simple melt blending mode and adopting a double-screw extruder for extrusion, so that the preparation process of the polyamide composite material is simple.

In summary, the present application has the following beneficial effects:

1. the strength and the flame retardance of the polyamide resin are enhanced by adding the carbon nano tube composite glass fiber, the polyamide composite material is ensured to have lower conductivity under the condition of larger addition amount of the carbon nano tube, and meanwhile, the definition of the marking pattern of the polyamide composite material is improved.

2. And coating the glass layer on the surface of the multi-wall carbon nano tube under the pressurizing condition, so that the glass layer is intercalated in the multi-wall carbon nano tube, the multi-wall carbon nano tube is prevented from being exposed at the cut surface, and the polyamide composite material is kept low in conductivity.

3. The glass layer of the carbon nano tube composite glass fiber contains a large amount of bubbles through the foaming treatment, so that the carbon nano tube composite glass fiber has the heat insulation effect.

Detailed Description

The present application is described in further detail below in connection with examples 1-12 and comparative examples 1-4.

Raw material name	Kind or source
		Polyamide resin	One or more of nylon 6, nylon 66, nylon 1010 and nylon 610Multiple compositions
Carbon nanotubes	CNT100 single-walled carbon nanotubes and CNT105 multi-walled carbon nanotubes sold by the company of the gold technology, ltd, of the germany of beijing.
		Glass powder	An Mi glass powder with low melting point sold by Nannon materials Co., ltd., D240, initial melting temperature of 400 ℃ and 2000 mesh
Halogen-free flame retardant	Halogen-free flame retardant HR5369 sold by Fushan City Rui Cheng Sujiao Co., ltd
		Anti-aging agent	Jewelry ultraviolet absorber 234
Auxiliary agent capable of laser marking	Composition of one or more of calcium carbonate, mica powder, talcum powder and titanium dioxide
		Lubricant	lonza brand lubricant PETS, model number of PETS-p

Preparation example

Preparation example 1

Preparation of carbon nano tube composite glass fiber:

s1, cleaning single-wall carbon nanotubes: baking the single-walled carbon nanotubes at 200 ℃ for 5 hours;

s2, cladding a glass layer: placing glass powder in a container, heating to 450 ℃ for melting, adding the single-walled carbon nanotubes obtained in the step S1 into the glass powder in a molten state, stirring and mixing, pressurizing the container to the gauge pressure of 1kPa, and continuing stirring for 16 hours to obtain a mixture; wherein, the mass ratio of the addition amount of the single-wall carbon nano tube to the glass powder is 1:3, a step of;

s3, preparing single-wall carbon nano tube composite glass fibers: draining the mixture obtained in the step S2 into a high-speed centrifuge, centrifuging at a rotating speed of 3000r/min, and preparing primary fibers through traction; and forming secondary fibers by drawing the primary fibers with 410 ℃ high-temperature annular air flow, standing the secondary fibers at room temperature for 8 hours, cooling, and cutting to obtain the single-walled carbon nanotube composite glass fibers, wherein the length of the single-walled carbon nanotube composite glass fibers is 10mm, and the diameter of the single-walled carbon nanotube composite glass fibers is 0.8mm.

Preparation example 2

Preparation of carbon nano tube composite glass fiber:

s1, cleaning single-wall carbon nanotubes: baking the single-walled carbon nanotubes at 200 ℃ for 1 hour;

s2, cladding a glass layer: placing glass powder in a container, heating to 450 ℃ for melting, adding the single-walled carbon nanotubes obtained in the step S1 into the glass powder in a molten state, stirring and mixing, pressurizing the container to the gauge pressure of 2kPa, and continuing stirring for 7 hours to obtain a mixture; wherein, the mass ratio of the addition amount of the single-wall carbon nano tube to the glass powder is 1:5, a step of;

s3, preparing single-wall carbon nano tube composite glass fibers: draining the mixture obtained in the step S2 into a high-speed centrifuge, and centrifuging at the rotating speed of 4000r/min to obtain primary fibers; and forming secondary fibers by drawing the primary fibers with 410 ℃ high-temperature annular air flow, standing the secondary fibers at room temperature for 12 hours, cooling, and cutting to obtain the single-walled carbon nanotube composite glass fibers, wherein the length of the single-walled carbon nanotube composite glass fibers is 10mm, and the diameter of the single-walled carbon nanotube composite glass fibers is 0.8mm.

Preparation example 3

Preparation of carbon nano tube composite glass fiber:

s1, cleaning single-wall carbon nanotubes: baking the single-walled carbon nanotubes at 350 ℃ for 3 hours;

s2, cladding a glass layer: placing glass powder in a container, heating to 450 ℃ for melting, adding the single-walled carbon nanotubes obtained in the step S1 into the glass powder in a molten state, stirring and mixing, pressurizing the container to the gauge pressure of 2kPa, and continuing stirring for 12 hours to obtain a mixture; wherein, the mass ratio of the addition amount of the single-wall carbon nano tube to the glass powder is 1:4, a step of;

s3, preparing single-wall carbon nano tube composite glass fibers: draining the mixture obtained in the step S2 into a high-speed centrifuge, and centrifuging at the rotating speed of 3600r/min to obtain primary fibers; and forming secondary fibers by drawing the primary fibers with high-temperature annular air flow at 410 ℃, standing the secondary fibers at room temperature for 10 hours, cooling, and cutting to obtain the single-walled carbon nanotube composite glass fibers, wherein the length of the single-walled carbon nanotube composite glass fibers is 10mm, and the diameter of the single-walled carbon nanotube composite glass fibers is 0.8mm.

Preparation example 4

The difference from preparation example 3 is that the multi-wall carbon nanotubes are equivalent to replace the single-wall carbon nanotubes, so as to obtain the multi-wall carbon nanotube composite glass fiber.

Preparation example 5

The difference from preparation example 3 is that no pressurization is performed in the vessel.

Preparation example 6

The difference from preparation example 4 is that no pressurization is performed in the vessel.

Preparation example 7

The difference from preparation example 4 is that the mixture in step S2 is subjected to foaming treatment, and the step S2 is as follows: placing glass powder in a container, heating to 450 ℃ for melting, adding the multiwall carbon nanotubes obtained in the step S1 into the glass powder in a molten state, stirring and mixing, keeping the temperature at 500 ℃, continuously introducing nitrogen into the glass powder in the molten state, keeping the gauge pressure at 2kPa, simultaneously stirring at 1000r/min for 12h, and stirring at 40r/min for 2h to obtain a mixture.

Preparation example 8

The difference from preparation example 4 is that the mixture in step S2 is subjected to foaming treatment, and the step S2 is as follows: placing glass powder in a container, heating to 450 ℃ for melting, adding the multiwall carbon nanotubes obtained in the step S1 into the glass powder in a molten state, stirring and mixing, keeping the temperature at 500 ℃, continuously introducing carbon dioxide into the glass powder in the molten state, keeping the surface pressure at 1kPa, simultaneously stirring at a rotating speed of 1500r/min for 5 hours, and stirring at a rotating speed of 100r/min for 4 hours to obtain a mixture.

Preparation example 9

The difference from preparation example 4 is that the mixture in step S2 is subjected to foaming treatment, and the step S2 is as follows: placing glass powder in a container, heating to 450 ℃ for melting, adding the multiwall carbon nanotubes obtained in the step S1 into the glass powder in a molten state, stirring and mixing, keeping the temperature at 500 ℃, continuously introducing carbon dioxide into the glass powder in the molten state, keeping the surface pressure at 2kPa, simultaneously stirring at the speed of 1200r/min for 10h, and stirring at the speed of 60r/min for 3h to obtain a mixture.

Preparation example 10

The difference from preparation example 9 is that the multi-wall carbon nano tube composite glass fiber is modified by a silane coupling agent, and the modification method is as follows:

s1, raw material preparation: heating the multi-wall carbon nano tube composite glass fiber to 300 ℃ for 2 hours to remove surface impurities;

preparing a modifier: preparing a silane coupling agent into a 2.3wt% aqueous solution to obtain a modifier;

s2, under the protection of nitrogen, placing the multi-wall carbon nano tube composite glass fiber in a modifier, heating to 65 ℃ under the stirring condition, reacting for 5 hours, fishing out the modified multi-wall carbon nano tube composite glass fiber, and cleaning with ethanol for 3 times to obtain the modified multi-wall carbon nano tube composite glass fiber.

PREPARATION EXAMPLE 11

s1, raw material preparation: heating the multi-wall carbon nano tube composite glass fiber to 400 ℃ for 2 hours to remove surface impurities;

preparing a modifier: preparing a silane coupling agent into a 3wt% aqueous solution to obtain a modifier;

s2, under the protection of nitrogen, placing the multi-wall carbon nano tube composite glass fiber in a modifier, heating to 75 ℃ under the stirring condition, reacting for 2 hours, fishing out the modified multi-wall carbon nano tube composite glass fiber, and cleaning with ethanol for 3 times to obtain the modified multi-wall carbon nano tube composite glass fiber.

Preparation example 12

s1, raw material preparation: heating the multi-wall carbon nano tube composite glass fiber to 350 ℃ for 1.5 hours to remove surface impurities;

preparing a modifier: preparing a silane coupling agent into a 2.5wt% aqueous solution to obtain a modifier;

s2, under the protection of nitrogen, placing the multi-wall carbon nano tube composite glass fiber in a modifier, heating to 70 ℃ under the stirring condition, reacting for 4 hours, fishing out the modified multi-wall carbon nano tube composite glass fiber, and cleaning with ethanol for 3 times to obtain the modified multi-wall carbon nano tube composite glass fiber.

Preparation example 13

The difference from preparation example 3 is that the glass fiber was prepared without adding single-walled carbon nanotubes.

Examples

Example 1

A halogen-free flame-retardant polyamide composite material with excellent electric leakage resistance and ultraviolet laser marking comprises the following components in mass:

55kg of polyamide resin, wherein the polyamide resin is nylon 66;

20kg of single-walled carbon nanotube composite glass fiber obtained in preparation example 1;

HR5369 5kg；

0.1kg of ultraviolet absorber 234;

1kg of laser marking auxiliary agent which is titanium white;

PETS 2kg。

a preparation method of a halogen-free flame-retardant polyamide composite material with excellent electric leakage resistance and ultraviolet laser marking comprises the following steps:

s1, mixing: weighing nylon 66, the single-walled carbon nanotube composite glass fiber obtained in preparation example 1, HR5369, an ultraviolet absorber 234, titanium dioxide and PETS according to the required mass, and stirring and mixing uniformly at normal temperature to obtain a prepared material;

s2, adding the prepared material obtained in the step S1 into a double-screw extruder, extruding by the double-screw extruder, wherein the rotation speed of a host machine is 500rpm, the extrusion temperature is 230 ℃, and granulating to obtain a finished material.

Example 2

72kg of polyamide resin, wherein the polyamide resin is a composition consisting of nylon 6, nylon 66, nylon 1010 and nylon 610 according to a mass ratio of 2:5:6:3;

55kg of single-walled carbon nanotube composite glass fiber obtained in preparation example 2;

HR5369 18kg；

234 kg of an ultraviolet absorber;

8kg of laser marking auxiliary agent which is mixed powder composed of calcium carbonate, mica powder, talcum powder and titanium dioxide according to the mass ratio of 4:4:8:7;

PETS 3kg。

s1, mixing: weighing nylon 6, nylon 66, nylon 1010 and nylon 610, the single-wall carbon nanotube composite glass fiber obtained in preparation example 2, HR5369, ultraviolet absorbent 234, calcium carbonate, mica powder, talcum powder, titanium white and PETS according to the required mass, and stirring and mixing uniformly at normal temperature to obtain a prepared material;

s2, adding the prepared material obtained in the step S1 into a double-screw extruder, extruding by the double-screw extruder, wherein the rotating speed of a host machine is 600rpm, the extruding temperature is 200 ℃, and granulating to obtain a finished material.

Example 3

65kg of polyamide resin, wherein the polyamide resin is a composition consisting of nylon 6 and nylon 66 according to a mass ratio of 5:5;

45kg of single-walled carbon nanotube composite glass fiber obtained in preparation example 3;

HR5369 12kg；

0.8kg of ultraviolet absorber 234;

5kg of laser marking auxiliary agent which is mixed powder of calcium carbonate and titanium dioxide according to the mass ratio of 4:7;

PETS 2.6kg。

s1, mixing: taking nylon 6, nylon 66, the single-wall carbon nano tube composite glass fiber obtained in preparation example 3, HR5369, an ultraviolet absorber 234, calcium carbonate, titanium pigment and PETS according to the required mass, and stirring and mixing uniformly at normal temperature to obtain a prepared material;

s2, adding the prepared material obtained in the step S1 into a double-screw extruder, extruding by the double-screw extruder, wherein the rotating speed of a host machine is 550rpm, the extruding temperature is 220 ℃, and granulating to obtain a finished material.

Example 4

The difference from example 3 is that the multi-wall carbon nanotube composite glass fiber obtained in preparation example 4 is equivalent to the single-wall carbon nanotube composite glass fiber obtained in preparation example 3.

Example 5

The difference from example 3 is that a single-walled carbon nanotube composite glass fiber was obtained in preparation example 5.

Example 6

The difference from example 3 is that the multi-wall carbon nanotube composite glass fiber obtained in preparation example 6 is equivalent to the single-wall carbon nanotube composite glass fiber obtained in preparation example 3.

Example 7

The difference from example 3 is that the multi-wall carbon nanotube composite glass fiber obtained in preparation example 7 is equivalent to the single-wall carbon nanotube composite glass fiber obtained in preparation example 3.

Example 8

The difference from example 3 is that the multi-wall carbon nanotube composite glass fiber obtained in preparation example 8 is equivalent to the single-wall carbon nanotube composite glass fiber obtained in preparation example 3.

Example 9

The difference from example 3 is that the multi-wall carbon nanotube composite glass fiber obtained in preparation example 9 is equivalent to the single-wall carbon nanotube composite glass fiber obtained in preparation example 3.

Example 10

The difference from example 3 is that the multi-wall carbon nanotube composite glass fiber obtained in preparation example 10 is equivalent to the single-wall carbon nanotube composite glass fiber obtained in preparation example 3.

Example 11

The difference from example 3 is that the multi-wall carbon nanotube composite glass fiber obtained in preparation example 11 is equivalent to the single-wall carbon nanotube composite glass fiber obtained in preparation example 3.

Example 12

The difference from example 3 is that the multi-wall carbon nanotube composite glass fiber obtained in preparation example 12 is equivalent to the single-wall carbon nanotube composite glass fiber obtained in preparation example 3.

Comparative example

Comparative example 1

The difference from example 3 is that the glass fiber obtained in preparation example 13 replaces the single-walled carbon nanotube composite glass fiber in equal amount.

Comparative example 2

The difference from example 3 is that the single-walled carbon nanotubes were not prepared as carbon nanotube composite glass fibers and were directly added.

Comparative example 3

The difference from example 4 is that the multiwall carbon nanotubes were added directly without being prepared as carbon nanotube composite glass fibers.

Comparative example 4

The difference from example 3 is that the carbon nanotube composite glass fiber is not added.

Performance test

The melt index of the finished material was tested with reference to ASTM D1238.

The tensile strength of the finished material was tested with reference to GB/T1040.2-2006.

The finished material was tested for flexural strength with reference to GB/T9341-2008.

The Comparative Tracking Index (CTI) of the product materials was tested with reference to GB/T4207.

The oxygen index of the product material was tested with reference to GB/T2406.2-2009.

And detecting the ultraviolet laser marking effect, and observing through a 500-time microscope to see whether the marking pattern is clear or not and whether explosion points exist or not.

The test results of examples 1-3 are detailed in Table 1.

The test results of examples 4-10 are detailed in Table 2.

The test results of comparative examples 1 to 4 are shown in Table 3.

TABLE 1

	Example 1	Example 2	Example 3
				Tensile Strength/MPa	59	61.7	60.4
Flexural Strength/MPa	98	108	103
				Comparative Tracking Index (CTI)/V	420	390	430
Oxygen index/%	27.7	28.4	27.8
				Ultraviolet laser marking effect	Clear, no explosion point	Clear, no explosion point	Clear, no explosion point

TABLE 2

	Example 4	Example 5	Example 6	Example 7	Example 8	Example 9	Example 10	Example 11	Example 12
										Tensile Strength/MPa	63.2	60.1	63.1	62.8.	62.7	62.6	64.8	64.2	64.6
Flexural Strength/MPa	111	101	111	108	107	106	117	116	118
										Comparative Tracking Index (CTI)/V	450	430	430	460	460	460	460	460	460
Oxygen index/%	33.2	26.1	27.4	36.2	37.5	37.1	37.2	37.6	37.4
										Ultraviolet laser marking effect	Clear, no explosion point	Clear, no explosion point	Clear, no explosion point	Clear, no explosion point	Clear, no explosion point	Clear, no explosion point	Clear, no explosion point	Clear, no explosion point	Clear, no explosion point

TABLE 3 Table 3

	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4
					Tensile Strength/MPa	47.2	59.4	59.7	41.5
Flexural Strength/MPa	78.4	96	98	68.4
					Comparative Tracking Index (CTI)/V	480	200	210	480
Oxygen index/%	22.7	14.3	14.0	18.1
					Ultraviolet laser marking effect	Unclear and explosive spot	Clear, with explosion point	Clear, with explosion point	Unclear and explosive spot

It can be seen from the combination of example 3 and comparative examples 1 to 4 that the addition of the carbon nanotube composite glass fiber keeps the electric leakage resistance of the polyamide material good, can also remarkably improve the strength and flame retardance of the polyamide material, and can also improve the ultraviolet laser marking effect of the polyamide composite material, so that the marking pattern is clear and has no explosion point.

It can be seen from a combination of examples 3 and 4 that the multi-walled carbon nanotube composite glass fiber is better than single-walled carbon nanotubes in maintaining the better leakage resistance of the polyamide composite material.

It can be seen from the combination of examples 3-4 and examples 5-6 that the multi-wall carbon nanotube composite glass fiber obtained by pressurizing during the preparation of the carbon nanotube composite glass fiber maintains the polyamide composite material with good leakage resistance, and at the same time, the flame retardance is remarkably enhanced.

It can be seen from the combination of examples 4 and examples 7 to 9 that the oxygen index of the polyamide composite material is made lower after the foaming treatment, the flame retardance of the polyamide composite material is improved, and the leak resistance of the polyamide composite material is also improved.

As can be seen from the combination of examples 9 and examples 10 to 12, the strength of the polyamide composite material is further enhanced by modifying the multi-walled carbon nanotube composite glass fiber with a silane coupling agent.

The present embodiment is merely illustrative of the present application and is not intended to be limiting, and those skilled in the art, after having read the present specification, may make modifications to the present embodiment without creative contribution as required, but is protected by patent laws within the scope of the claims of the present application.

Claims

1. The halogen-free flame-retardant polyamide composite material with excellent electric leakage resistance and ultraviolet laser marking is characterized by comprising the following components in parts by weight:

55-72 parts of polyamide resin;

5-18 parts of halogen-free flame retardant;

0.1-1 part of anti-aging agent;

1-8 parts of a laser marking auxiliary agent;

2-3 parts of a lubricant;

the carbon nano tube composite glass fiber is a multi-wall carbon nano tube composite glass fiber, and the preparation method of the multi-wall carbon nano tube composite glass fiber comprises the following steps:

2. The excellent leakage resistance, ultraviolet laser marking, halogen-free flame retardant polyamide composite material as claimed in claim 1, wherein: the mixture is subjected to foaming treatment, a large number of bubbles are formed in the molten glass powder fluid, and the gas in the bubbles is carbon dioxide or nitrogen.

3. The excellent leakage resistance, ultraviolet laser marking, halogen-free flame retardant polyamide composite material as claimed in claim 2, wherein: the foaming treatment method comprises the following steps: placing the glass powder in a molten state in a closed container, heating to enable the glass powder to be kept in the molten state, continuously introducing carbon dioxide or nitrogen into the glass powder in the molten state, keeping the surface pressure at 1-2kPa, stirring at the rotating speed of 1000-1500r/min for 5-12h, and stirring at the rotating speed of 40-100r/min for 2-4h to finish foaming treatment.

4. The excellent leakage resistance, ultraviolet laser marking, halogen-free flame retardant polyamide composite material as claimed in claim 1, wherein: the laser marking auxiliary agent is one or a combination of more of calcium carbonate, mica powder, talcum powder and titanium dioxide.

5. The excellent leakage resistance, ultraviolet laser marking, halogen-free flame retardant polyamide composite material as claimed in claim 1, wherein: the polyamide resin is one or a combination of more than one of nylon 6, nylon 66, nylon 1010 and nylon 610.

6. The excellent leakage resistance, ultraviolet laser marking, halogen-free flame retardant polyamide composite material as claimed in claim 1, wherein: the carbon nano tube composite glass fiber is modified by a silane coupling agent, and the modification method comprises the following steps:

s1, raw material preparation: heating the carbon nano tube composite glass fiber to 300-400 ℃ for 1-2h to remove surface impurities;

preparing a modifier: preparing a silane coupling agent into a 2.3-3wt% aqueous solution to obtain a modifier;

7. A method for preparing the excellent electric leakage resistance, ultraviolet laser marking and halogen-free flame retardant polyamide composite material as claimed in any one of claims 1-6, which is characterized by comprising the following steps: