CN104046009B - A kind of nylon 6 and the compositions of politef - Google Patents

Abstract

The invention provides a composition of nylon 6 and polytetrafluoroethylene: in a high-pressure reactor, pour pure water, a polymerization inhibitor, add a certain amount of dispersant, initiator, nylon 6 powder, vinylidene fluoride , perfluoromethyl vinyl ether, maleic anhydride, heated up to the reaction temperature, after the reaction is finished, nylon 6 with surface polymerization is obtained, the product is filtered, dried, then mixed with polytetrafluoroethylene in a high-speed mixer, and then mixed with polytetrafluoroethylene in a high-speed mixer. Grind and crush in a pulverizer to obtain the patented product.

Description

A kind of composition of nylon 6 and polytetrafluoroethylene

technical field

The invention relates to a preparation method of modified nylon, in particular to a composition of nylon 6 and polytetrafluoroethylene.

Background technique

Nylon (PA) has high mechanical properties, impact properties, high heat resistance, excellent wear resistance, self-lubrication, good processability, and good mechanical balance. It is widely used in household appliances, automobile industry and tools. It is widely used in the manufacturing industry, and its application ranks first among the five major engineering plastics. Pure nylon cannot meet the requirements of roller transport wheels, gears, mechanical connectors and other products in terms of mechanical strength, and ordinary mineral and fiber-reinforced modifications cannot meet the requirements of such products in terms of wear resistance and toughness.

As an impact modifier, the blend of polyolefin and nylon is a phase dispersion structure in which the modified polyolefin is dispersed in the nylon matrix into a sea-island shape (0.11-1 μm in diameter), and the modified polyolefin becomes an impact energy absorber. , this type of alloy can improve the impact strength and reduce moisture absorption of nylon at low temperature and dry state. Blending alloys of nylon and polyolefins containing hydrocarbon groups or graft copolymers of their elastomers can obtain super-tough nylon materials.

CN101885910 relates to a high wear-resistant PA6 composite material and its preparation method. The composite material is composed of the following components and raw materials in weight percentage: nylon 56-82%, wear-resistant agent 1# 2-5%, wear-resistant agent 2# 2-5%, glass fiber powder 5-15%, glass microspheres 5-15%, graft type toughening modifier 2-8%, nucleating agent 0.1-0.5%, antioxidant 0.1-1%, Lubricant dispersant 0.1-0.5%. Compared with the prior art, the invention has the advantages of high wear resistance, high heat resistance, high toughness and high fluidity. The anti-wear agent 1# is polytetrafluoroethylene, and the anti-wear agent 2# is molybdenum disulfide. The graft type toughening modifier is a graft polymerized oligomer grafted with unsaturated acid or acid anhydride to a polyolefin elastomer (POE), and is a maleic anhydride grafted polyolefin elastomer.

EPO, 649,738 A1 discloses that by adding polyglutarimide to the polyamide, a positively locked polyamide and polyvinyl fluoride connection can be produced. Thus, for example, a two-layer laminate can be produced from polyamide and polyvinyl fluoride by using a one-step extrusion process and an adhesion promoter consisting of a mixture of polyamide, polyamide polyglutarimide layer, and polyvinyl fluoride to make a three-layer laminate.

The existing known technologies of PA6-containing compositions all have the disadvantages of complex components, poor compatibility between polymers, uneven mixing, etc., which affect the use effect in industrial devices.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention provides a composition of nylon 6 and polytetrafluoroethylene.

In the high-pressure reactor, add pure water, polymerization inhibitor, add a certain amount of dispersant, initiator, nylon 6 powder, vinylidene fluoride, perfluoromethyl vinyl ether, maleic anhydride, and heat up to the reaction temperature After the reaction is finished, nylon 6 polymerized on the surface is obtained. The product is filtered, dried, then mixed with polytetrafluoroethylene in a high-speed mixer, and then ground and crushed in a mill to obtain the patented product.

The present invention introduces a small amount of vinylidene fluoride with fluorine elements, perfluoromethyl vinyl ether, and maleic anhydride on the surface of nylon 6 particles as comonomers, and performs surface modification, which can improve the phase of nylon 6 and PTFE polymers. Capacitance.

The invention provides a composition of nylon 6 and polytetrafluoroethylene, which is achieved through the following steps:

Step 1. Preparation of water phase

In parts by weight, add 1000 parts of water and 0.5-2 parts of emulsifier (preferably 1 part) into the autoclave, and stir evenly;

Step 2. Preparation of oil phase

In the reactor, 100 parts of nylon 6 and 0.5-3 parts (preferably 1.5 parts) of maleic anhydride are mixed in parts by weight, and then 0.05-0.1 parts of initiator (preferably 0.05 parts) are added and stirred evenly.

Step 3. Polymerization

Add the oil phase solution prepared in step 2 to the reactor equipped with the prepared water phase in step 1, and feed 0.5-3 parts (preferably 1.5 parts) of vinylidene fluoride monomer, 0.05-0.5 parts (preferably 0.2 parts) ) perfluoromethyl vinyl ether monomer, and then react from 70-100°C (preferably 80°C) for 8-20h (preferably 10h), after the reaction is completed, the material is discharged, and the product is filtered and dried.

Step 4. Blending

Mix 70-95 parts of surface-modified nylon 6 powder obtained in step 3 with 5-30 parts of PTFE powder, mix in a high-speed mixer, and grind and crush in a mill to obtain the patented product.

The chemical dispersant includes any one of perfluorooctanoic acid potassium salt or ammonium salt and perfluoroalkane sulfonic acid sodium salt or ammonium salt. Potassium perfluorooctanoate is preferred.

The initiator is preferably potassium persulfate, ammonium persulfate.

The high-speed mixer is a commercially available product, such as the high-speed mixer product professionally produced by Nanjing Maiben Machinery.

The pulverizers may be used to prepare/mix dry powders or other materials, and such equipment may include, without limitation, for example: agitators of various types, including rotary agitators, and pulverizers of various types, including ball mills, Electromagnetic ball mill, disc mill, pin mill, high energy impact mill, flow energy impact mill, reverse nozzle jet mill, fluidized bed jet mill, hammer mill, roller mill, mechanical diffusion processor, or impact mill. In said pulverizer, high speed and high intensity can be applied or applied to the dry powder material to achieve high shear or high impact application to the dry powder material, preferably a fluidized bed jet mill. It is a commercially available product, such as the product produced by Mianyang Liuneng Powder Equipment Co., Ltd.

The vinylidene fluoride is a commercially available product, such as a product produced by Shandong Huaxia Shenzhou New Material Co., Ltd.

The perfluoromethyl vinyl ether is a commercially available product, such as the product produced by Zhonglan Chenguang Chemical Co., Ltd.

The nylon 6 is a commercially available product, such as the 1013G30 grade nylon 6 product of Mitsubishi Engineering of Japan.

Beneficial effects of the present invention:

Nylon 6 is surface-modified by maleic anhydride, vinylidene fluoride monomer, and perfluoromethyl vinyl ether monomer, which improves the compatibility with polytetrafluoroethylene, and can be fully contacted and dispersed during the grinding and mixing process. more evenly. The fluorine-containing polymer is coated on the surface of the nylon 6 particles, which reduces the surface energy of the nylon 6 particles, improves the scratch resistance of the particle surface, and reduces the friction coefficient of the composition.

detailed description

The following examples are only to further illustrate the present invention, but not to limit the protection scope of the present invention.

The invention provides a composition of nylon 6 and polytetrafluoroethylene, which is achieved through the following steps:

Example 1

Step 1. Preparation of water phase

Add 1000Kg of water and 1Kg of potassium perfluorooctanoate into a 2000L autoclave, and stir evenly.

Step 2. Preparation of oil phase

In a 200L reactor, mix 100 parts of nylon 6 and 1.5 parts of maleic anhydride, then add 0.08 parts of ammonium persulfate and stir evenly.

Step 3. Polymerization

Add the oil phase solution prepared in step 2 to the reaction kettle equipped with the prepared water phase in step 1, feed 1.5Kg vinylidene fluoride monomer, 0.2Kg perfluoromethyl vinyl ether monomer, and then from 90 Reaction at ℃ for 14 hours, discharge after the reaction, filter and dry to obtain surface-grafted nylon 6 powder.

Step 4. Blending and crushing

80Kg of surface-grafted nylon 6 powder obtained in step 3 is then mixed with 20Kg of PTFE powder, mixed in a 500L high-speed mixer, and then ground and crushed in a fluidized bed jet mill to obtain the patented product. The number is SX-1.

Example 2

Step 1. Preparation of water phase

Add 1000Kg of water and 0.5Kg of sodium perfluoroalkane sulfonate into a 2000L autoclave, and stir evenly.

Step 2. Preparation of oil phase

In a 200L reactor, mix 100Kg of nylon 6 and 0.5Kg of maleic anhydride, then add 0.05Kg of potassium persulfate, and stir evenly.

Step 3. Polymerization

Add the oil phase solution prepared in step 2 to the reaction kettle equipped with the prepared water phase in step 1, feed 0.5Kg vinylidene fluoride monomer, 0.05Kg perfluoromethyl vinyl ether monomer, and then from 70 Reaction at ℃ for 20 hours, discharge after the reaction, filter and dry to obtain surface-grafted nylon 6 powder.

Step 4. Blending and crushing

70Kg of surface-grafted nylon 6 obtained in step 3 is mixed with 30Kg of PTFE powder in a 300L high-speed mixer, and then ground and crushed in a fluidized bed jet mill to obtain the patented product. The number is SX-2.

Example 3

Step 1. Preparation of water phase

Add 1000Kg of water and 2Kg of ammonium perfluoroalkane octanesulfonate into a 2000L autoclave, and stir evenly.

Step 2. Preparation of oil phase

In a 200L reactor, mix 100Kg nylon 6 and 3Kg maleic anhydride, then add 0.1Kg potassium persulfate and stir evenly.

Step 3. Polymerization

Add the oil phase solution prepared in step 2 to the reaction kettle equipped with the prepared water phase in step 1, feed 2Kg vinylidene fluoride monomer, 0.5Kg perfluoromethyl vinyl ether monomer, and then from 100°C React for 10 hours, discharge after the reaction, filter and dry to obtain surface-grafted nylon 6.

Step 4. Blending and crushing

90 parts of the surface-grafted nylon 6 powder obtained in step 3 are mixed with 10 parts of PTFE powder in a 300L high-speed mixer, and then ground and crushed in a fluidized bed jet mill to obtain the patented product. The number is SX-3.

Comparative example 1

Nylon 6 is not grafted, only the blending of step 4 is carried out, and the reaction of steps 1-3 is not carried out, and the others are the same as in Example 1. The resulting product number is SX-4.

Comparative example 2

Only nylon 6 is used as a single component, and the product number is SX-5.

Example 4

The friction coefficients of the micropowders prepared in Examples 1-3 and Comparative Examples 1-2 were tested according to the GB3960-83 standard. The test load is 20Kg.

Example sample coefficient of friction SX-1 0.17 SX-2 0.19 SX-3 0.12 SX-4 0.32 SX-5 0.59

Claims (1)

1. a composition of nylon 6 and polytetrafluoroethylene, is characterized in that its preparation method may further comprise the steps: Step 1. Preparation of water phase In parts by weight, add 1000 parts of water and 0.5-2 parts of emulsifier into the autoclave, and stir evenly; Step 2. Preparation of oil phase In the reactor, mix 100 parts of nylon 6 and 0.5-3 parts of maleic anhydride in parts by weight, then add 0.05-0.1 part of initiator and stir evenly; Step 3. Polymerization Add the oil phase solution prepared in step 2 to the reactor equipped with the prepared water phase in step 1, add 0.5-3 parts of vinylidene fluoride, 0.05-0.5 parts of perfluoromethyl vinyl ether monomer, and then add The reaction temperature is 8-20 hours at 70-100°C. After the reaction is completed, the material is discharged, and the product is filtered and dried; Step 4. Blending Mix 70-95 parts of surface-modified nylon 6 powder obtained in step 3 with 5-30 parts of PTFE powder, mix in a high-speed mixer, and then grind and crush in a mill to obtain the nylon 6 and polyamide Composition of tetrafluoroethylene.