Black high-light-transmittance reinforced nylon 6 material and preparation method thereof

Abstract

The invention discloses a black high-light-transmittance reinforced nylon 6 material and a preparation method thereof. The black high-light-transmittance reinforced nylon 6 material comprises the following raw materials in percentage by weight: 54-89% of polyamide (PA); 10-40% of a reinforcing component; 0.2 to 1.0 percent of black light-transmitting powder; and 0.2-2.0% of an anti-reflection agent. A heat stabilizer and a lubricant may also be included. The laser light transmittance of the material reaches 40% or above, and the material has wide market prospects.

Description

Technical Field

[0001] The present invention relates to a reinforced nylon 6 material, and particularly to a black high-transparency reinforced nylon 6 material and a preparation method thereof. Background Art

[0002] Polyamide 6 materials have good mechanical properties, heat resistance, chemical reagent resistance and other characteristics, and are widely used. However, since PA6 materials are semi-crystalline materials, the light transmittance of the materials is generally average. After adding glass fiber reinforcement, due to the fact that the diameter of glass fibers is generally between 10 and 14 μm, there are still problems of overlap or incomplete dispersion of glass fiber bundles. The diameter is already higher than the wavelengths of many mid-infrared lights, thus affecting the light transmittance and further reducing the light transmittance of the material. Black additives are very easy to absorb light, greatly reducing the light transmittance of black materials. Therefore, how to improve the light transmittance of black glass fiber-reinforced materials, especially the transmittance of infrared light, can well expand the application range of the materials.

[0003] Regarding the light-transmitting patents related to semi-crystalline PA fiber-added materials, the Chinese patent with the publication number CN104910620A discloses a nylon composite material and a preparation method thereof, especially a glass fiber-reinforced high-transparency laser-weldable nylon composite material and a preparation method thereof, belonging to the field of materials technology. The composite material is composed of the following components: nylon 66, nylon 6, 43-74 parts by weight; pretreated alkali-free and arsenic-free chopped glass fibers 20-40 parts by weight; high-transparency composite synergist 5-15 parts by weight; other additives 1-2 parts by weight. The product of the present invention has environmental protection, high light transmittance, meets the requirements of EU Rohs, and has excellent comprehensive performance of glass fiber reinforcement, and is especially suitable for the fields of laser welding and fields with high requirements for the light transmittance of materials.

[0004] The Chinese patent with the publication number CN202110012843.3 discloses a light-transmitting nylon 66 and a synthesis method and application thereof. The synthesis method includes the following steps: adding hexamethylenediamine and bismaleimide to an aqueous solution of nylon 66 salt, and carrying out a pressure-holding stirring reaction at a temperature of 220-225 °C and a pressure of 1.5-2 MPa for 1-2 h; after returning to normal pressure, adding antioxidant 1098 and antioxidant 168 to the system, adjusting the pressure to 0.1-0.2 MPa and the temperature to 265-275 °C, and stirring for 30-60 min, then discharging and pelletizing to obtain light-transmitting nylon 66. The obtained light-transmitting nylon 66 has excellent tensile strength and transparency and can be applied to fields with high transparency requirements. Summary of the Invention

[0005] The present invention solves the problem that the light transmittance of PA6 materials is greatly reduced after being prepared into black. Due to the use of special quality carbon black for compounding, during the process of obtaining high-brightness black, the light scattering is less and the influence on the transmittance is small.

[0006] The present invention solves the problem that the light transmittance of PA6 material is greatly reduced after adding glass fiber reinforcement. Since the diameter of the fibrous reinforcing component added in this invention is within 3um, it has passed surface pretreatment and the glass fiber has been pre-dispersed, which will not affect the propagation of light waves and has little impact on the light transmittance. While for the current market reinforcing materials, the diameter of the selected glass fiber is between 10 - 14um, which is larger than some infrared wavelengths (the wavelengths of near-infrared and mid-infrared are less than 14um), thus affecting the light penetration.

[0007] The present invention adds appropriate metal salts to reduce the crystallization performance of nylon, reduce the crystal growth rate, reduce the crystal particle size, and improve the light transmittance of the material.

[0008] The present invention is realized through the following technical solutions A black high-light-transmittance reinforced nylon 6 material and its preparation method, comprising raw materials in the following weight percentages: Polyamide (PA) 54 - 89%; Reinforcing component 10 - 40%; Black light-transmitting powder 0.2 - 1.0%; Light transmittance enhancer 0.2 - 2.0%.

[0009] Preferably, it may also contain heat stabilizer and lubricant.

[0010] The polyamide PA is one or two of shiny PA6 with different viscosities, long carbon chain PA610, and PA612. It is mainly PA6 substrate, and the relative viscosity of PA6 is 2.2 - 2.45. Nylon 6 with the model M12400 produced by Guangdong Xinhui Meida Nylon Co., Ltd. or nylon 6 with the model TP4205 produced by Taiwan Jisheng Co., Ltd. can be selected. The low-viscosity PA6 base material mainly ensures that the material has good fluidity.

[0011] The reinforcing component is selected as ultra-fine glass fiber, preferably the model with a diameter of 2.0 - 2.5um, and it has undergone special surface treatment and pre-granulation before use.

[0012] The black light-transmitting powder is one or two of transparent black organic pigment B12, blue-phase black B667, transparent oil-based black powder BM, or BASF's Black 0087.

[0013] The light transmittance enhancer is one or more of metal oxide calcium chloride and organic nucleating agent. The dosage range of calcium chloride is preferably 0.2 - 0.8%, and the more preferred dosage is 0.4 - 0.6%.

[0014] The heat stabilizer is an antioxidant, which can be one or more of N,N-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine (antioxidant 1098), tris[2,4-di-tert-butylphenyl] phosphite (antioxidant 168), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (antioxidant 1010), bis(2,4-dicumylphenyl) pentaerythritol diphosphite (antioxidant 9228).

[0015] The lubricant is one or more of calcium stearate, modified ethylene bisfatty acid amide (TAF), and ethylene-acrylic acid copolymer. Preferably, modified ethylene bisfatty acid amide (TAF) is used, which has a good lubrication effect and can prevent the leakage of glass fiber. The dosage range of TAF is preferably 0.3-0.7%, and the more preferred dosage is 0.4-0.6%.

[0016] A black high-transparency reinforced nylon 6 material and its preparation method include the following steps.

[0017] (1). Soak the ultrafine glass fiber cotton in a 1% KH550 solution at 60°C for 0.5 hours, then dehydrate it at high speed by a centrifuge. Use a mixer to knead with PA6 powder at 230°C for 10-20 minutes, and then use a crusher to crush it into irregular small particles of glass fiber masterbatch for standby. The glass fiber content in the masterbatch is 73-75%.

[0018] (2). Mix PA6, heat stabilizer, lubricant, black light-transmitting powder, light transmittance enhancer, etc. evenly, add them to a twin-screw extruder through the main feeder, and then add the small particles of glass fiber masterbatch to the twin-screw extruder through the side feeder. After mixing by a screw combination with high shear and high dispersibility, through extrusion, strand drawing, cooling, pelletizing and drying, a black high-transparency reinforced nylon 6 material is prepared.

[0019] For the black high-transparency reinforced nylon 6 material and its preparation method, the ratio of the length to the diameter of the twin-screw extruder is 36-44:1.

[0020] The temperatures of each working section in the twin-screw extruder are as follows: 225~245~240~240~230~220~210~215°C~215°C~210, the die head temperature is 245°C, and the main machine speed is 300-600 rpm / min.

[0021] While reinforcing and darkening the nylon reinforced material of the present invention, the negative impact on light transmittance is reduced as much as possible, so that the black PA6 material has high light transmittance while improving strength, and can be widely used in places where light transmittance is required. It expands the application problem of black reinforced materials in the field where light transmission is needed. The laser light transmittance of the material of the present invention reaches more than 40%, and it has a broad market prospect. Embodiment

[0022] The present invention will be further described below in conjunction with Comparative Examples 1-4 and Examples 1-5.

[0023] Weigh each raw material according to the ratio in Table 1. Mix PA6, black powder, nylon clarifying agent, stabilizer, and lubricant evenly, and add them to the twin-screw extruder through the main feeder. Then add the glass fiber masterbatch from the side feeder. After mixing through a screw combination with low shear and high dispersibility, and through extrusion, strand drawing, cooling, pelletizing, and drying, a black high-transparency reinforced nylon 6 material is prepared. In Comparative Example 1, conventional alkali-free short glass fibers were directly added through the side feeder. In Comparative Example 2, pulverized ultrafine glass fiber cotton that was not masterbatch was directly added through the side feeder.

[0024] The temperatures of each working section in the twin-screw extruder are 225~245~240~240~230~220~210~215°C~215°C~210, the die head temperature is 245°C, and the main machine speed is 300~600 rpm / min.

[0025] Compare the blackness and light transmittance of the prepared materials. The laser transmittance is directly detected using a laser power meter, and a 2-mm-thick plate is selected for testing.

[0026] Table 1. Specific ratios of Comparative Examples 1-4 and Examples 1-5 Formulation Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 Example 4 Example 5 PA6 / M12400 68.7 68.7 58.4 58.7 58.4 58.2 51.4 45.3 45 Conventional alkali-free short glass fiber / Jushi glass fiber 30 Glass fiber prefabricated masterbatch / glass fiber content 75% 40 40 40 40 47 53 53 Ultra-fine glass fiber cotton crushing side feeding addition 30 Common carbon black 0.4 0.4 0.4 Black light-transmitting powder / transparent oil-based black powder BM 0.4 0.4 0.4 0.4 0.5 0.6 Transparency enhancer / calcium chloride 0.3 0.3 0.5 0.3 0.3 0.5 Stabilizer / compound of 1098 and 168, compounding ratio 1:1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Lubricant / TAF 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Table 2. Performance analysis results of Comparative Examples 1-4 and Examples 1-5 Performance Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 Example 4 Example 5 L value (blackness) 25.89 26.00 26.12 26.18 26.10 26.22 26.25 26.23 26.12 Laser transmittance (2mm thick color plate) 28% 30% 33% 37% 44% 48% 44% 42% 43% From the above comparison data, it is found that for conventional black PA6+GF materials, the blackness L value is within 26, and the laser transmittance is within 30%; when using ultrafine glass fibers with a smaller diameter as the reinforcing component, the light transmittance is improved; after adding black light-transmitting powder, the light transmittance is further improved; an appropriate amount of clarifying agent can slow down the crystallization rate of the material to a certain extent, resulting in smaller PA6 crystal grains, which is conducive to the penetration of light and improves the light transmittance of the material. It can be seen from the comparative examples and examples that when the blackness is close, to achieve a laser transmittance of more than 40%, it is necessary to add ultrafine glass fiber masterbatch, black light-transmitting powder, and clarifying agent at the same time, and the light transmittance is well improved.

Claims

1. A black high-transmittance reinforced nylon 6 material and a preparation method thereof, comprising the following raw materials in percentage by weight: Polyamide (PA) 54~89%; Reinforcement component 10~40%; Black translucent powder 0.2~1.0%; Permeability enhancer 0.2~2.0%.

2. The black high light transmittance reinforced nylon 6 material according to claim 1, comprising the following raw materials in percentage by weight: Polyamide (PA) 54~89%; Reinforcement component 10~40%; Black translucent powder 0.2~1.0%; Transparent agent 0.2~2.0% Heat stabilizer 0.2~1.5% Lubricant 0.4~1.5%.

3. A black high light transmittance reinforced nylon 6 material according to claim 1 or 2, characterized in that: The polyamide (PA) is one or two of glossy PA6, long carbon chain PA610 and PA612 with different viscosities.

4. A black high light transmittance reinforced nylon 6 material according to claim 1 or 2, characterized in that: The reinforcing component is ultra-fine glass fiber with special surface treatment.

5. The black high light transmittance reinforced nylon 6 material according to claim 4, characterized in that: The reinforcing component is a preparation method of ultrafine glass fiber with special surface treatment, which is as follows: the ultrafine glass fiber wool is soaked in a 1% KH550 solution at 60°C for 0.5 hour, then dehydrated at high speed by a centrifuge, and kneaded with PA6 powder at 230°C for 10-20 minutes by a mixer, and then crushed into irregular small glass fiber masterbatch particles by a pulverizer.

6. A black high light transmittance reinforced nylon 6 material according to claim 1 or 2, characterized in that: The black light-transmitting powder is one or two of transparent black organic pigment B12, blue phase black B667, transparent oily black powder BM or BASF's Black 0087.

7. A black high light transmittance reinforced nylon 6 material according to claim 1 or 2, characterized in that: The permeability enhancer is one or more of metal oxide calcium chloride and organic nucleating agent.

8. The black high light transmittance reinforced nylon 6 material according to claim 2, characterized in that: The heat stabilizer is an antioxidant, which is one or more of N,N-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine (antioxidant 1098), tris[2,4-di-tert-butylphenyl]phosphite (antioxidant 168), tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester (antioxidant 1010), and bis(2,4-dicumylphenyl)pentaerythritol diphosphite (antioxidant 9228).

9. The black high light transmittance reinforced nylon 6 material according to claim 2, characterized in that: The lubricant is one or more of calcium stearate, modified ethylene bis fatty acid amide (TAF), and ethylene-acrylic acid copolymer.

10. A method for preparing a black high light transmittance reinforced nylon 6 material according to claim 1 or 2, comprising the steps of: (1) Soak the ultra-fine glass fiber wool in a 1% KH550 solution at 60°C for 0.5 hours, then dehydrate it with a centrifuge at high speed, use a mixer and PA6 powder to mix at 230°C for 10-20 minutes, and then use a pulverizer to crush it into irregular glass fiber masterbatch small particles for standby use. The glass fiber content in the masterbatch is 73-75%; (2): PA6, heat stabilizer, lubricant, black light-transmitting powder, light-increasing agent, etc. are mixed evenly and added into a twin-screw extruder through the main feed, and then small particles of glass fiber masterbatch are added into the twin-screw extruder through the side feed, and mixed through a high-shear, high-dispersion screw combination, extruded, drawn, cooled, pelletized and dried to obtain a black high-transmittance reinforced nylon 6 material; The aspect ratio of the twin-screw extruder is 36-44:1; the temperature of each working section in the twin-screw extruder is: 225-245-240-240-230-220-210-215℃-215℃-210, the die head temperature is 245℃, and the main engine speed is 300-600rpm / min.