High-GWIT halogen-free flame-retardant nylon material special for alternating current contactor and capable of being marked by infrared laser

Abstract

The invention discloses a special high-GWIT (glow wire ignition temperature) halogen-free flame-retardant nylon material capable of being identified by infrared laser for an alternating current contactor. The nylon material is prepared from the following raw materials in percentage by weight: 32.1-67.7% of PA6 slices; 25 to 40% of chopped glass fiber; 5-15% of a nitrogen flame retardant; 2-10% of a synergistic flame retardant; 0.1%-1.2% of a stabilizer; 0.1 to 0.7% of a lubricant; and 0.1-1% of toner. The prepared material is used for an alternating current contactor, and has the characteristics of infrared laser identification, high GWIT (glow wire ignition temperature), no halogen and flame retardance.

Description

TECHNICAL FIELD

[0001] The present application relates to halogen-free flame-retardant polyamide materials, in particular to an infrared laser markable, high GWIT halogen-free flame-retardant nylon material special for AC contactors. BACKGROUND

[0002] Glass fiber reinforced nitrogen-based flame-retardant polyamide materials are widely used in the low-voltage electrical industry due to their halogen-free environmental protection, low toxicity, and good glow wire ignition resistance, but in order to avoid the "lamp wick effect", the overall mechanical properties are low and the GWIT is usually only 725℃ (0.8mm), which limits the main application of glass fiber reinforced MCA flame-retardant nylon materials to small circuit breakers in the low-voltage electrical industry.

[0003] The ultraviolet laser marking effect of nitrogen-based flame-retardant polyamide materials is relatively easy to achieve whether it is white to black or black to white, but infrared light is more difficult to effectively mark.

[0004] The base and the upper cover of the AC contactor require infrared marking due to their high flame retardation and high GWIT (the domestic large factory requires that the GWIT of all parts of the whole machine be higher than 750℃). Only phosphorus-based flame-retardant or bromine-based flame-retardant glass fiber reinforced nylon materials can be selected. However, the disadvantages of these two flame-retardant systems are obvious: the color of red phosphorus flame-retardant materials is severely limited, and the problem of acid precipitation and darkening of light color is easy to occur. The huge price increase of bromine and antimony flame-retardant materials this year has brought great cost pressure to the downstream. SUMMARY

[0005] The present application is prepared by using low-viscosity PA6 material, special processing temperature, and short-cut glass fibers fed from the second machine cylinder with a loss weight scale, and the main flame retardant and the synergistic flame retardant are stirred uniformly and then fed from the sixth machine cylinder with a loss weight scale.

[0006] The present application is realized by the following technical solutions.

[0007] An infrared laser markable, high GWIT halogen-free flame-retardant nylon material special for AC contactors is composed of the following raw materials in weight percentage: PA6 chips 32.1~67.7%; Short-cut glass fibers 25~40%; Nitrogen-based flame retardant 5~15%; Synergistic flame retardant 2~10%; Stabilizer 0.1~1.2%; Lubricant 0.1~0.7%; Color powder 0.1~1%.

[0008] The relative viscosity index of PA6 chip in the above-mentioned special infrared laser markable high GWIT halogen-free flame-retardant nylon material for AC contactors is 1.8-2.4, preferably one or two of 1.8 viscosity and 2.0 viscosity, and most preferably a 1.8 viscosity PA6 resin with the brand J1601.

[0009] The above-mentioned special infrared laser markable high GWIT halogen-free flame-retardant nylon material for AC contactors, wherein the short glass fiber has a length of 3-5 mm and a single filament diameter of 9-13 μm, preferably a length of 4.5 mm and a single filament diameter of 10 μm, and most preferably the glass fiber is ECS3014B-4.5-H from Chongqing International.

[0010] The above-mentioned special infrared laser markable high GWIT halogen-free flame-retardant nylon material for AC contactors, wherein the nitrogen-based flame retardant is MCA, and the MCA is in the form of powder, preferably in a range of 5-15%, and most preferably in an amount of 7%.

[0011] The above-mentioned special infrared laser markable high GWIT halogen-free flame-retardant nylon material for AC contactors, wherein the synergistic flame retardant is a granulated mixture of red phosphorus masterbatch and montmorillonite, and most preferably the ratio is PA6 1.8 viscosity:montmorillonite:red phosphorus masterbatch=4:2:4, wherein the red phosphorus masterbatch is added by side feeding, preferably in a ratio of 2-10%, and most preferably in a ratio of 5%.

[0012] The above-mentioned special infrared laser markable high GWIT halogen-free flame-retardant nylon material for AC contactors, wherein the stabilizing additive 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), and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), preferably the main antioxidant is 1010, the auxiliary antioxidant is 1098, the addition ratio is 2:1, and the preferred addition amount is 0.6%.

[0013] The above-mentioned special infrared laser markable high GWIT halogen-free flame-retardant nylon material for AC contactors, wherein the lubricant is one or more of calcium stearate, modified ethylene bis fatty acid amide (TAF), ethylene-acrylic acid copolymer, PETS, and aminated PETS, preferably aminated PETS, and the preferred addition amount is 0.5%.

[0014] The aminated PETS is self-made by the present application; the preparation method of the aminated PETS is as follows: PETS and epichlorohydrin are reacted in a potassium hydroxide alkaline solution, the reaction temperature is 80-100 DEG C, the reaction time is 10-12 hours, an epoxy propyl ether intermediate is generated, then the obtained intermediate is added into excess ethylenediamine, the reaction is carried out for 24 hours, and vacuum distillation is carried out, so that the aminated PETS is obtained.

[0015] The special infrared laser markable high GWIT halogen-free flame-retardant nylon material for AC contactors has inorganic toner, and the white pigment must be zinc sulfide, and red and blue toner is not directly added.

[0016] The special infrared laser markable high GWIT halogen-free flame-retardant nylon material for AC contactors is prepared by using a double-screw extruder for extrusion granulation, the length-diameter ratio of the screw of the double-screw extruder is 40:1, the main machine rotation speed is 350 rpm, the temperature of each temperature zone of the double-screw extruder is set as follows: zone 1: 180 DEG C, zones 2 to 10: 190-225 DEG C, and the die head: 225 DEG C; the chopped glass fiber is fed from the side of the second machine cylinder, and the flame retardant is added from the sixth machine cylinder. DETAILED DESCRIPTION

[0017] The PA6 1.8 resin and the montmorillonite are uniformly stirred by using a high-speed stirring device, and the stirring time is 2 min; the pre-stirring is completed, the red phosphorus master batch is added from the side of the sixth machine cylinder, the extruder and auxiliary equipment are started, and the extrusion draw bar is cut into particles to prepare the synergistic flame retardant.

[0018] The PA6 J1601 resin, the processing aid and the toner are uniformly stirred and fed from the main feeding, the chopped glass fiber is fed from the side of the second machine cylinder, the nitrogen-based flame retardant and the synergistic flame retardant are uniformly stirred and fed from the side of the sixth machine cylinder, and then the extruder and auxiliary equipment are started, and the extrusion draw bar is cut into particles.

[0019] The present application will be further described below in combination with Comparative Example 1 and Examples 1-11.

[0020] The raw materials are weighed according to the proportions in Table 1, mixed in a high-speed mixer, and then extruded and granulated into a composite material by a double-screw extruder. The composite materials prepared in the above comparative example and examples are subjected to conventional physicochemical analysis and glowing wire test Table 1 shows the specific proportions of Comparative Example 1 and Examples 1-11.

[0021] Material description Comparative example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 J1601 48 48 49 50 51 50 50 50 49 50 49 48 ECS3014B-4.5-H 35 35 35 35 35 35 35 35 35 35 35 35 Powder MCA 15 13 11 9 7 7 7 7 7 5 5 5 Synergistic flame retardant 0 2 3 4 5 6 6 6 7 8 9 10 Stabilizer 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Lubricant (TAF) 0.5 0.5 0.5 0.5 0.5 0.5 / / / / / / Lubricant (PETS) / / / / / / 0.5 / / / / / Lubricant (aminated PETS) / / / / / / / 0.5 0.5 0.5 0.5 0.5 Color powder 1 (conventional color matching scheme contains red and blue color powder) 1 (no red added, blue added) 1 (no blue added, no red added) 1 (no blue added, no red added) 1 (no blue added, no red added) 1 (no blue added, no red added) 1 (no blue added, no red added) 1 (no blue added, no red added) 1 (no blue added, no red added) 1 (no blue added, no red added) 1 (no blue added, no red added) Test item Table 2 shows the results of the conventional physicochemical performance analysis of Comparative Example 1 and Examples 1-11.

[0022] Test method Comparative example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Bending strength Mpa (GB / T 9341-2008) Bending modulus Mpa 160 164 162 164 165 158 153 164 155 165 160 160 (GB / T 9341-2008) Heat distortion temperature (℃) 8933 8950 8715 8811 8998 8777 8680 8898 8856 8891 8789 8931 GB / T 9341-2008 GWFI (960℃ / 1.0mm) 195 190 185 185 190 188 186 192 193 185 187 188 GB / T5169.11-2017 GWIT (0.8mm) √ √ √ √ √ × × √ × × × × GB / T5169.11-2017 Red light marking effect (black on white) 725 725 750 750 775 725 700 800 650 650 650 650 A trace A trace Clear Clear Clear Clear Clear Clear Clear Clear Clear Clear Clear Clear From the data in Table 2, it can be known that the PA6 GF35 glass fiber reinforced nitrogen-based flame-retardant nylon material, when the MCA addition ratio is 7%, the synergistic flame retardant addition ratio is 6%, the lubricant is amino PETS, and the color powder formula is designed without directly adding red and blue color powder, a high GWIT, infrared markable glass fiber reinforced halogen-free flame-retardant nylon material is finally prepared, which has good GWIT, GWFI, heat distortion temperature and red light marking effect.

[0023] The above implementation examples are only used to illustrate the use of the present application, but not to limit the present application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, all equivalent technical solutions should belong to the scope of the present application, which should be limited by the claims.

Claims

1. An infrared laser markable, high GWIT halogen-free flame retardant nylon material for AC contactor, which is composed of the following raw materials in percentage by weight: PA6 chip 32.1~67.7%; Short glass fiber 25~40%; Nitrogen-based flame retardant 5~15%; Synergistic flame retardant 2~10%; Stabilizer 0.1~1.2%; Lubricant 0.1~0.7%; Color powder 0.1~1%.

2. The infrared laser markable, high GWIT halogen-free flame retardant nylon material for AC contactor according to claim 1, wherein the PA6 chip has a relative viscosity index of 1.8-2.4 viscosity.

3. The infrared laser markable, high GWIT halogen-free flame retardant nylon material for AC contactor according to claim 1, wherein the short glass fiber has a length of 3-5 mm and a single filament diameter of 9-13 μm.

4. The infrared laser markable, high GWIT halogen-free flame retardant nylon material for AC contactor according to claim 1, wherein the nitrogen-based flame retardant is MCA, which is in the form of powder.

5. The infrared laser markable, high GWIT halogen-free flame retardant nylon material for AC contactor according to claim 1, wherein the synergistic flame retardant is a granulated mixture of red phosphorus master batch and montmorillonite, wherein the red phosphorus master batch is added to the granulation by side feeding.

6. The infrared laser markable, high GWIT halogen-free flame retardant nylon material for AC contactor according to claim 1, wherein the stabilizer 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), and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010).

7. The infrared laser markable, high GWIT halogen-free flame retardant nylon material for AC contactor according to claim 1, wherein the lubricant is one or more of calcium stearate, modified ethylene bis fatty acid amide (TAF), ethylene-acrylic acid copolymer, PETS, and aminated PETS.

8. The infrared laser markable, high GWIT halogen-free flame retardant nylon material for AC contactor according to claim 7, wherein the aminated PETS is prepared by the following method: PETS and epichlorohydrin are reacted in a potassium hydroxide alkaline solution at a temperature of 80-100 °C for 10-12 hours to form an epoxy propyl ether intermediate, and then the obtained intermediate is added to excess ethylenediamine and reacted for 24 hours, followed by vacuum distillation to obtain the aminated PETS.

9. The infrared laser markable, high GWIT, halogen-free flame-retardant nylon material for AC contactor special use according to claim 1, characterized in that the toner is inorganic toner, added according to actual color matching requirements, and white pigment must use zinc sulfide, and red and blue toner is not directly added.

10. The preparation method of the infrared laser markable, high GWIT, halogen-free flame-retardant nylon material for AC contactor special use according to any one of claims 1-9, prepared by extrusion granulation using a double screw extruder, the screw length-diameter ratio of the double screw extruder is 40:1, the main machine rotation speed is 350 rpm, and the temperature of each temperature zone is set as follows: zone 1: 180℃, zone 2 to zone 10: 190-225℃, die head: 225℃; the chopped glass fiber is fed from the second section of the machine cylinder side, and the flame retardant is added from the sixth section of the machine cylinder.