WO2006053492A1

WO2006053492A1 - The use of polyamide composite for preparing pump or valve

Info

Publication number: WO2006053492A1
Application number: PCT/CN2005/001930
Authority: WO
Inventors: Huafeng Zhu; Rong Zhu
Original assignee: Huafeng Zhu; Rong Zhu
Priority date: 2004-11-19
Filing date: 2005-11-16
Publication date: 2006-05-26
Also published as: CN1631981A; CN1240779C

Abstract

The present invention relates to the use of polyamide composition for preparing pump or valve, and particularly, to the method of prepare pump or valve by using polycaprolactam composite and to the pump or valve molded from the composite. The molded pump or valve is prepared by mixing thoroughly 60-80wt% caprolactam monomer, 2-30wt% fillers, 1.4-3wt% sodium metal or sodium hydroxide, 3-6wt% co-catalyst and the like in a reaction vessel under stirring, casting the resultant mixture into a mold and polymerizing the mixture. The resultant pump or valve has excellent mechanical properties, such as tensile strength ≥ 97 Mpa, abrasive resistance is two or three times to that of steel, high impact resistance, high resistance to acid or alkali, good self-lubricating property, high resilience factor, low water-absorption ratio, which is 2-2.5 times low than that of common engineering plastics, and stable dimension.

Description

Application of polyamide composites in the preparation of pumps or valves

This invention relates to the use of polyamide composites for the preparation of pumps or valves, and more particularly to a method of making a pump or valve from a polycaprolactam composite and to a product. Background technique

Polyamide composite material (or engineering plastics) is a kind of polymer composite material, which can directly replace non-ferrous metal materials such as tin bronze, aluminum bronze, brass, babbitt, stainless steel, etc., and has been widely used in petroleum, chemical, metallurgical, etc. Industrial applications, and can be used in industrial applications such as automotive parts, mechanical parts, electrical appliances, electronic components. For example, the Chinese patent CN 1151931A discloses a method for manufacturing a cast nylon pipe, which is characterized in that the lactam is used as a main raw material, and centrifugal casting polymerization is carried out in a mold, and the obtained pipe has acid and alkali resistance, corrosion resistance, and the like. Features. CN 1157001A discloses a process for preparing coils, non-coiled tubes, sheets, films and the like using known methods using blends comprising polyamide-low density polyethylene. However, no reports have been found on the preparation of industrial valves or pumps using polyamide engineering plastics. Pumps or valves made of other engineering plastics, although having good physical properties and processing properties, have the disadvantage of high water absorption and unstable product size and performance. Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for preparing a polyamide pump or valve which has low water absorption and stable performance, and a product obtained by the method, in order to overcome the above drawbacks.

Polyamide engineering plastics combines the main advantages of general engineering plastics. They use the amino and carboxyl groups at the end of the parent main chain and are reactive under certain conditions. Chemicals are added by adding various fillers and modifiers during the reaction. Physical modification solves the defects of product size and performance changes due to water absorption, and the comprehensive performance is significantly improved, so that it is suitable for manufacturing various special equipments, especially pumps and valves widely used in industry.

The object of the present invention can be achieved by the following technical solutions:

The invention provides a method for preparing a pump or a valve by using a polyamide composite material, which comprises: stirring and mixing a raw material, pouring it into a preheating mold for casting polymerization molding, characterized in that a polymerization raw material for preparing a pump or a valve is prepared. These include caprolactams, fillers, catalysts and cocatalysts.

The polymeric starting material comprises, by weight percent, 60-80% caprolactam, 2-30% filler, 1.4-3% sodium metal or sodium hydroxide and 3-6% cocatalyst.

The filler used is selected from one or more of glass fiber, talc, wood fiber, alumina powder, carbon black, graphite, and kaolin. The cocatalyst is selected from the group consisting of amides, caprolactams, isocyanates or derivatives thereof, preferably acetylcaprolactam and tribendamidine triisocyanate. The specific preparation method is as follows:

1. Preparation of the mold: According to the requirements of the product, select various molds of different shapes, clean and reserve, according to the raw material formula, preheat the mold to a curing temperature of about 150-180 Ό;

2. Preparation of polymeric raw materials: Different raw material formulations are determined according to the different requirements of pump and valve performance. In the reaction vessel, add caprolactam, filler and catalyst metal sodium or sodium hydroxide, masticate in the range of 120-200 Torr for 20-40 minutes, then depressurize, water, add cocatalyst, stir and mix quickly. Evenly, cast immediately.

3. Casting and polymerization curing: The pre-activated raw materials prepared above are injected into a mold preheated to 140-180 ° C, kept for 20-30 minutes, and then released after cooling to obtain a product.

The casting method includes: horizontal casting, centrifugal casting, vacuum casting, vibration casting, etc., and can also be embedded, rolled, molded, etc., and can be selected by a person skilled in the art as needed.

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In addition, various additives commonly used in the art, such as stabilizers, antioxidants, lubricants, flame retardants, color masterbatches, coupling agents and impact modifiers, may be added during the casting process as needed. To further improve the performance of the product. ,

The pump or valve made of the polyamide engineering plastic of the invention has good mechanical properties, the tensile strength is equal to or greater than 97Mpa, the wear resistance is 2-3 times that of the steel product, impact resistance, acid and alkali resistance, self-lubrication Good character and resilience, especially low water absorption, 2-2.5 times lower than the water absorption of general engineering plastics, and stable product size. BEST MODE FOR CARRYING OUT THE INVENTION The following examples are merely illustrative of the invention and are not intended to limit the scope of the invention. Example 1

In the reaction vessel, add 1 kg of lactam, 0.3 kg of glass fiber, 2 g of carbon black, 2 g of graphite, 0.035 g of silane coupling agent, blend and stir for 10 minutes, and masticate at a temperature of 120 ° C for 15 minutes. , adding 1.5 g of sodium hydroxide, and then masticating for 20-30 minutes, the temperature is about 140 ° C, vacuum decompression, dehydrating to below 300 ppm at ^750 mmHg, adding 4-6 ml of triphenylmethane triisocyanate and 0. 5 ml of azobisisobutyronitrile initiator, stir well, immediately inject into 15CTC mold, keep warm for 20-30 minutes, release the product to obtain the product. Example 2

In the reaction vessel, 1 kg of caprolactam, 0. 15 kg of alumina powder, 2 g of carbon black, 2 g of molybdenum disulfide, 0. 035 g of silicon germanium coupling agent, blending and stirring for 10 minutes, at a temperature of 12 (TC) Under, mastication 5 毫升分分分分分分分分分分分分分分分分分分分分分分分02 ml of dibenzoyl peroxide, after stirring evenly, inject 150 immediately. In the C mold, keep warm for 20-30 minutes, and release the product to obtain the product. Example 3

Cast polymerization was carried out in the same manner as in Example 1, except that the raw material was changed to 1 kg of lactam, using ACR 0.02 kg, carbon black 2 g, sodium hydroxide 3 g, and diphenyl carbonate 3. 5 ml.

Among them, ACR is the abbreviation of ternary graft copolymer of methyl methacrylate, butadiene and styrene. It is a product of Singapore Wu Yu Chemical Co., Ltd., and its grades are ACR-ZB-1 , ACR-ZB-5 , ACR -ZB401,

ACR-ZB-201 and the like can be used in the present invention.

The performance data of the materials obtained in Examples 1-3 are now listed in Table 1 below.

Table 1

It can be seen from the data in Table 1 that the technical performance indexes of the obtained engineering plastics are different for the three different raw material formulations. According to the different stress conditions of the pump and the valve, different materials can be used for preparing pumps or valves for different purposes. The first material, which has the characteristics of hardness and bending strength, is used for the production of valve stems and upper valve bodies, spheres and pump shafts, etc. The second material, which has both hardness and temperature resistance and toughness, is used for Production of seat, pump casing; The third material can be used to produce seals, impact parts, etc.

The pump and valve produced by the polyamide engineering plastic of the present invention are excellent in performance and can be used for preparing pumps and valves for various purposes. For example, industrial ball valves, gate valves, globe valves, plunger valves, check valves with working pressures below 4. OMpa, and butterfly valves with working pressures below 1. 6Mpa. Its performance and technical indicators meet and exceed the technical requirements of similar steel products, and are widely used in petroleum, chemical, hydropower, metallurgy, pharmaceutical and other industrial fields.

Claims

A method for preparing a pump or a valve using a polyamide composite material, the method comprising: stirring and mixing a raw material, pouring it into a preheating mold for casting polymerization molding, wherein the polymerization raw material used for preparing the pump or the valve comprises Has been lactam, a filler, a catalyst and a cocatalyst.

2. A method of preparing a pump or valve according to claim 1, wherein the polymerization raw material comprises, by weight percent, 60-80% caprolactam, 2-30% filler, 1.4-3% sodium metal or sodium hydroxide And 3-6% cocatalyst.

A method of preparing a pump or valve according to claim 2, wherein the filler is selected from one or more of glass fiber, talc, lignocellulosic, alumina powder, carbon black, graphite, and kaolin.

A method of producing a pump or valve according to claim 2, wherein the cocatalyst is selected from the group consisting of an amide, a caprolactam, an isocyanate or a derivative thereof.

A method of producing a pump or valve according to claim 4, wherein the cocatalyst is selected from the group consisting of acetyl caprolactam and tribendamidine triisocyanate.

6. A pump produced by the preparation method according to any one of claims 1-4.

A valve produced by the production method according to any one of claims 1 to 4.