WO2021103360A1 - Application of emulsifying wax as film-forming agent in workpiece waste heat blackening and waste heat blackening liquid preparation - Google Patents

Abstract

Disclosed in the present invention is an application of emulsifying wax as a film-forming agent in workpiece waste heat blackening; also disclosed in the present invention is an application of emulsifying wax as a film-forming agent in waste heat blackening liquid preparation; further, also disclosed in the present invention is a formula of a waste heat blackening liquid containing emulsifying wax. During workpiece treatment using a blackening liquid of the present invention, when a workpiece to be blackened contacts the blackening working liquid containing emulsifying wax, the emulsifying wax is demulsified using waste heat of the workpiece to be blackened, and part of the wax carries a color paste and is deposited on the surface of the workpiece to be blackened, thereby forming a black film layer; the wax which fails to be deposited on the surface of the workpiece gradually accumulates and floats on the surface of the working liquid, and the floating wax is removed by means of a filter circulation device, thereby solving the problem in conventional waste heat blackening technologies that an organic polymer resin is deposited on the bottom of a tank. Moreover, the emulsifying wax black film has excellent corrosion resistance (the salt spray resistance time is not shorter than 48 h) and excellent brightness (which makes the workpiece look black, shiny and attractive), and the marketing requirements for black and shiny appearance and high corrosion resistance of a blackened workpiece are met.

Description

The application of emulsifying wax as a film-forming agent in the blackening of workpieces and the preparation of blackening liquid Technical field

The invention relates to the application of emulsified wax as a film-forming agent in the aspect of blackening after heat of a workpiece, and also relates to the application of emulsifying wax as a film-forming agent in the aspect of preparing a blackening liquid of after-heat, belonging to the technical field of blackening of the workpiece.

Background technique

The blackening process refers to the formation of a dense black protective film on the surface of the metal workpiece by physical or chemical methods, thereby enhancing the anti-rust ability of the workpiece and beautifying the appearance of the workpiece. According to different film forming principles, the blackening process can be divided into oxidation blackening, normal temperature blackening, phosphating blackening and residual heat blackening.

With the increase of national and regional requirements for environmental protection, waste heat blackening technology has gradually become the mainstream technology for industrial blackening in the recent period. Residual heat blackening is usually after heat treatment or the use of residual heat in other processing processes, so that at the moment when the steel workpiece comes into contact with the blackening working fluid, a layer of blackening film that is firmly bonded and not easy to fall off is formed on the surface of the steel workpiece.

The current waste heat blackening technology adopts organic polymer resin blackening film forming process. By selecting different film-forming polymer resins, the purpose of regulating the thickness of the blackening film and the corrosion resistance of the blackening film is achieved. Under normal circumstances, the appearance of the black resin film after heat is dim, not bright, and has poor corrosion resistance. The neutral salt spray test generally does not exceed 12 hours. In order to make the appearance of the workpiece black and bright and beautiful and improve the corrosion resistance in the atmosphere, it is usually necessary to apply anti-rust oil treatment after the blackening. The blackened workpiece treated with anti-rust oil has a black and bright appearance, and has a long salt spray resistance time, generally not exceeding 48 hours. However, such processing costs are high and the operation is cumbersome. In addition, in order to ensure that the organic polymer blackening resin is in a good film-forming state, the temperature of the blackening working fluid is generally maintained at 30 ℃ ~ 50 ℃, but sometimes the temperature of the local bath can reach 100 ℃, and the higher local temperature is not conducive to The stability of the organic resin emulsion is prone to demulsification and precipitation, leading to blackening and failure, so that a large amount of invalid polymer resin is deposited at the bottom of the blackening tank, which easily induces the tank liquid to rot and smell, causing production shutdown and affecting production efficiency. In addition, after repeated impacts of high-temperature workpieces, the blackened resin in the blackening working fluid is deposited on the surface of the workpiece to form a film. Most of the polymer resin around the workpiece is impacted by the high-temperature workpiece, and demulsification, thermal polymerization, and thermal polymerization will also occur. Cross-linking and other reactions aggravate the problem of blackening resin deposits at the bottom of the blackening groove.

technical problem

In order to solve the problems in the prior art, the present invention provides a waste heat blackening liquid that uses emulsified wax as a film-forming substance. When the blackening liquid is demulsified at a high temperature, the wax that fails to deposit on the surface of the workpiece (separated Wax) will float on the surface of the working fluid, and then through the filter circulation device, the floating wax will be removed, so that there will be no polymer resin deposits at the bottom of the blackening tank.

Technical solutions

The application of emulsified wax as a film-forming agent in the blackening of the workpiece after heat.

The application of emulsified wax as a film-forming agent in the preparation of waste heat blackening liquid.

Wherein, the blackening liquid consists of the following components by mass: 20-40 parts of emulsified wax, 1.5-3.5 parts of water-based color paste, 0.5-1 part of organic alcohol amine, 1~3 parts of defoamer, 0~ 1 part of film-forming aid and the balance is water.

Wherein, the emulsified wax is a cationic, anionic or non-ionic wax emulsion made from paraffin wax, microcrystalline wax, soap wax, wax paste, modified paraffin, oxidized paraffin, various synthetic waxes, insect wax or carnauba wax as raw materials One of them.

Among them, various synthetic waxes are Fischer-Tropsch wax, polyethylene wax, polypropylene wax, ethylene acetic acid copolymer wax or ethylene oxide wax.

Wherein, the organic alcohol amine is one of monoethanolamine, triethanolamine, isopropanolamine or diglycolamine.

Wherein, the pigment used in the water-based color paste is carbon black, iron oxide black, chrome black, aniline black, phthalocyanine blue, phthalocyanine green, or titanium dioxide, or any two or more of them are mixed in any ratio.

Wherein, the defoaming agent is a silicone type defoaming agent or a polyether type defoaming agent.

Wherein, the film-forming auxiliary agent is one or two or more of a wetting agent, a thickening agent, a defoaming agent, a leveling agent, a pH adjusting agent, or a corrosion inhibitor in an arbitrary ratio.

After the emulsified wax film is formed on the surface of the workpiece, the film is dense and smooth, which has an excellent effect of isolating air and moisture, and has excellent insulation against corrosive media such as oxygen and moisture that can corrode with the steel, so that the corrosion resistance of the workpiece is improved . Film-forming substances of different materials have different glossiness on the surface of the workpiece. When natural light is reflected on the surface of the film and mainly specular reflection, the film has a higher glossiness, and the workpiece appears black and bright. Appearance: When the natural light reflected on the surface of the film is mainly diffuse reflection, the appearance of the workpiece at this time is a matt gray appearance; when the emulsified wax is used as a film-forming substance to form a film on the surface of the workpiece, compared with the traditional resin emulsion film, The surface is denser and smoother, and the light is mainly specularly reflected on the surface of the film, so the appearance of the workpiece is black and bright.

The waste heat blackening liquid of the present invention using emulsified wax as the film-forming substance is diluted with water to a solution with a mass fraction of 10-20% (blackening working liquid), and the steel workpiece with a temperature of 300°C-500°C is immersed in the solution and soaked After 80-120 seconds, take out the workpiece and dry it with hot air. A blackening film with high corrosion resistance and bright appearance is formed on the surface of the workpiece. The blackening working fluid will blacken the groove during the normal service cycle (3~6 months). There is no sediment inside.

Beneficial effect

When the blackening liquid of the present invention is used to treat the workpiece, when the blackened workpiece contacts the blackening working liquid containing emulsified wax, the residual heat of the blackened workpiece is used to demulsify the emulsified wax, and part of the wax entraps the colored paste and deposits on the surface of the blackened workpiece. A blackening film layer is formed, and the wax that fails to deposit on the surface of the workpiece gradually accumulates and floats on the surface of the working fluid. The floating wax is removed through the filter circulation device, thereby solving the problem of the organic polymer resin depositing in the tank in the traditional waste heat blackening technology. At the same time, the emulsified wax blackening film has excellent corrosion resistance (salt spray resistance time is not less than 48 hours) and brightness (makes the appearance of the workpiece black and bright and beautiful), which can meet the black and bright appearance of the blackened workpiece on the market. High corrosion resistance requirements.

Embodiments of the present invention

The technical solution of the present invention will be further described below in conjunction with specific embodiments.

All components in the formula of the blackening liquid in the embodiment of the present invention are commercially available products.

Example 1

Mix 20 parts of water-based high-density polyethylene wax emulsion, 1 part of triethanolamine, 3 parts of silicone defoamer, 1.5 parts of water-based black color paste and 74.5 parts of RO water, and stir the mixture uniformly to prepare wax emulsion type hair Black liquor.

Heat the hexagonal half-tooth bolts with the model of M10*70 in the mesh belt tempering furnace to 450 ℃, heat preservation for 1 hour, and immerse the mesh belt into the blackening working fluid with a mass fraction of 20%. After soaking in the medium for 90 seconds, the liquid is lifted with the mesh belt, and the workpiece is dried with hot air at 100°C to obtain a blackened workpiece with a uniform appearance and a black and bright appearance. The workpiece was subjected to a 5% neutral salt spray test in accordance with GB/T 10125, and there was no rust for 52 hours.

The blackening liquid prepared in Example 1 has a stable blackening effect after three months of continuous use, and there is no polymer resin deposit at the bottom of the blackening tank.

Example 2

Mix 40 parts of carnauba wax emulsion, 0.5 parts of monoethanolamine, 2 parts of polyether defoamer, 2 parts of water-based black color paste, 0.5 part of phthalocyanine blue, 1.0 part of phthalocyanine green and 54 parts of tap water, and stir the mixture After homogenization, a wax emulsion type blackening liquid is obtained.

The workpiece is blackened by waste heat treated by a blackening liquid with a mass fraction of 15%, and the workpiece has a black and bright appearance. The 5% neutral salt spray test is carried out in accordance with GB/T 10125, and the salt spray resistance test time is 72 hours.

The blackening liquid prepared in Example 2 has a stable blackening effect after three months of continuous use, and there is no polymer resin deposit at the bottom of the blackening tank.

Example 3

35 parts of paraffin emulsion, 1 part of monoethanolamine, 1 part of polyether defoamer, 1.5 parts of water-based black color paste and 61.5 parts of tap water are mixed, and the mixture is uniformly stirred to obtain a wax emulsion type blackening liquid.

The workpiece is blackened by residual heat treated by a blackening liquid with a mass fraction of 10%, and the appearance of the workpiece is black and bright. According to GB/T 10125, the 5% neutral salt spray test is carried out, and the salt spray resistance test time is 68 hours.

The blackening liquid prepared in Example 3 has a stable blackening effect after three months of continuous use, and there is no polymer resin deposit at the bottom of the blackening tank.

In the process of using the waste heat blackening liquid using emulsified wax as a film-forming substance, the polymer resin does not precipitate at the bottom of the blackening tank, thereby reducing the time for stopping production and cleaning the tank to a certain extent and achieving the purpose of improving production efficiency. The blackening liquid of the present invention can be widely used in the blackening treatment of various specifications of fasteners, chains, springs, prestressed anchors, and various mechanical and automobile parts. It is especially suitable for working conditions where the appearance of blackened workpieces is required to be black and bright in the continuous production process, and the production rhythm is fast. The workpiece processed by the blackening liquid of the present invention has the characteristics of uniform blackening film layer, black and bright appearance, dense film layer, and high corrosion resistance, which meets the requirements of oxalic acid spot experiment and copper sulfate spot experiment specified in GB/T15519. According to GB/T 10125, a 5% neutral salt spray test is carried out, and the blackened workpiece can reach no rust within 72 hours.

Claims (9)

The application of emulsified wax as a film-forming agent in the blackening of the workpiece after heat. The application of emulsified wax as a film-forming agent in the preparation of waste heat blackening liquid. The application of the emulsified wax as a film-forming agent in the preparation of waste heat blackening liquid according to claim 2, characterized in that: the blackening liquid is composed of the following components by mass: 20-40 parts of emulsified wax, 1.5 ~3.5 parts of water-based color paste, 0.5~1 part of organic alcohol amine, 1~3 parts of antifoaming agent, 0~1 part of film-forming auxiliary and the balance is water. The application of the emulsified wax as a film-forming agent in the preparation of waste heat blackening liquid according to claim 3, characterized in that: the emulsified wax is paraffin wax, microcrystalline wax, soap wax, wax paste, modified paraffin, oxidized wax One of the cationic, anionic or non-ionic wax emulsions made from paraffin wax, various synthetic waxes, insect wax or carnauba wax. The application of emulsifying wax as a film-forming agent in the preparation of waste heat blackening liquid according to claim 4, characterized in that: various synthetic waxes are Fischer-Tropsch wax, polyethylene wax, polypropylene wax, ethylene acetic acid copolymer wax or oxidation Vinyl wax. The use of emulsifying wax as a film-forming agent in the preparation of waste heat blackening liquid according to claim 3, characterized in that: the organic alcohol amine is monoethanolamine, triethanolamine, isopropanolamine or diglycolamine One kind. The application of emulsifying wax as a film-forming agent in the preparation of waste heat blackening liquid according to claim 3, characterized in that the pigment used in the water-based color paste is carbon black, iron oxide black, chrome black, aniline black, phthalocyanine One or two or more of blue, phthalocyanine green or titanium dioxide can be mixed in any ratio. The application of the emulsified wax as a film-forming agent in the preparation of waste heat blackening liquid according to claim 3, characterized in that the defoaming agent is a silicone type defoaming agent or a polyether type defoaming agent. The application of the emulsified wax as a film-forming agent in the preparation of waste heat blackening liquid according to claim 3, characterized in that: the film-forming assistant is a wetting agent, a thickening agent, a defoaming agent, a leveling agent, One or two or more of pH adjusters or corrosion inhibitors are mixed in any ratio.