阅读说明：本技术 一种用于免防锈剂自攻螺丝的表面防腐防锈处理工艺 (Surface anticorrosion and antirust treatment process for antirust-free self-tapping screw ) 是由 张朝辉 于 2021-09-23 设计创作，主要内容包括：本发明公开了一种用于免防锈剂自攻螺丝的表面防腐防锈处理工艺,具体涉及涉及自攻螺丝表面防腐防锈处理技术领域,包括如下具体步骤：步骤(1)、制备无铬锌铝防腐涂料；步骤(2)、表面除油；步骤(3)、抛丸；步骤(4)、浸涂、低温固化；步骤(5)、烘干制得成品。本发明所述的一种用于免防锈剂自攻螺丝的表面防腐防锈处理工艺,采用低温固化无铬锌铝涂层,使其在自攻螺丝表面形成致密的多层保护层,不含六价铬,超低VOC排放,无环境污染问题产生,具有较为环保的性能,同时,低温固化无铬锌铝涂层对工件机械性能无影响,无需电镀打底,耐盐雾性能高,适用于室内工艺中的轻钢龙骨和石膏板之间的连接,具有广阔的应用前景。(The invention discloses a surface anticorrosion and antirust treatment process for a self-tapping screw without an antirust agent, and particularly relates to the technical field of surface anticorrosion and antirust treatment of the self-tapping screw, which comprises the following specific steps: step (1), preparing a chromium-free zinc-aluminum anticorrosive paint; step (2), removing oil on the surface; step (3), shot blasting; step (4), dip coating and low-temperature curing; and (5) drying to obtain a finished product. According to the surface anticorrosion and antirust treatment process for the antirust-free self-tapping screw, a low-temperature curing chromium-free zinc-aluminum coating is adopted, so that a compact multilayer protective layer is formed on the surface of the self-tapping screw, hexavalent chromium is not contained, the discharge of VOC is ultralow, the problem of environmental pollution is avoided, the environment-friendly performance is realized, meanwhile, the low-temperature curing chromium-free zinc-aluminum coating has no influence on the mechanical performance of a workpiece, electroplating and priming are not needed, the salt spray resistance is high, the process is suitable for connection between a light steel keel and a gypsum board in an indoor process, and the application prospect is wide.)

1. A surface anticorrosion and antirust treatment process for a rust inhibitor-free self-tapping screw is characterized by comprising the following specific steps:

step (1), preparing the chromium-free zinc-aluminum anticorrosive paint: preparing raw materials according to the following weight percentages: 30-40% of zinc-aluminum powder, 3-7% of emulsifier, 1-5% of defoamer, 21-25% of silane coupling agent, 3-7% of dispersant, 2-6% of methanol and the balance of deionized water, and mixing the components to prepare the chromium-free zinc-aluminum anticorrosive paint for later use;

step (2), surface degreasing: taking a self-tapping screw, soaking the self-tapping screw in a water-based degreasing agent, stirring by using a stirrer to remove surface oil stains, washing by using clean water, and naturally airing for later use;

step (3), shot blasting: putting the self-tapping screw subjected to oil removal and air drying in the step (2) into a shot blasting machine for shot blasting, and performing surface treatment to improve the surface smoothness of the self-tapping screw;

step (4), dip coating and low-temperature curing: immersing the automatic screw subjected to shot blasting treatment into the chromium-free zinc-aluminum anticorrosive coating prepared in the step (1), uniformly coating the chromium-free zinc-aluminum anticorrosive coating on the surface of the self-tapping screw, taking out, and curing and drying at low temperature of 250 ℃;

step (5), preparing a finished product: and (5) repeating the step (4) for 2-20 times, and drying to obtain the self-tapping screw with the chromium-free zinc-aluminum anticorrosive coating.

2. The surface anticorrosion and antirust treatment process for a rust-preventive agent-free self-tapping screw, according to claim 1, characterized in that: the chromium-free zinc-aluminum anticorrosive paint prepared in the step (1) comprises the following specific steps:

step (11): sequentially adding zinc-aluminum powder, an emulsifier, methanol, a defoaming agent and a dispersing agent into a container for mixing and stirring, so that the zinc-aluminum powder, the emulsifier, the methanol, the defoaming agent and the dispersing agent are completely mixed to prepare a mixture A;

step (12): adding a silane coupling agent into deionized water, and continuously stirring until the silane coupling agent and the deionized water are completely mixed to obtain a mixture B;

step (13): and adding the mixture B into the mixture A for three times, uniformly stirring after adding the mixture B each time until all the mixture B is completely added into the mixture A, and stirring and mixing again to obtain the chromium-free zinc-aluminum anticorrosive paint.

3. The surface anticorrosion and antirust treatment process for a rust-preventive agent-free self-tapping screw, according to claim 1, characterized in that: the defoaming agent in the step (1) is selected from any one of mineral oil type water-based defoaming agents or solvent oil.

4. The surface anticorrosion and antirust treatment process for a rust-preventive agent-free self-tapping screw, according to claim 1, characterized in that: the silane coupling agent adopts any one of gamma-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane and gamma-methacryloxypropyltrimethoxysilane.

5. The surface anticorrosion and antirust treatment process for a rust-preventive agent-free self-tapping screw, according to claim 1, characterized in that: the emulsifier is one or a combination of several of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester and polyoxyethylene polyoxypropylene block polyether.

6. The surface anticorrosion and antirust treatment process for a rust-preventive agent-free self-tapping screw, according to claim 1, characterized in that: the dispersing agent is selected from any one of OP-10, Tween-20 and octadecyl alcohol polyoxyethylene ether.

7. The surface anticorrosion and antirust treatment process for a rust-preventive agent-free self-tapping screw, according to claim 1, characterized in that: the mass ratio of zinc to aluminum in the zinc-aluminum powder selected in the step (1) is 2: 1-5: 1, the particle size ratio of zinc to aluminum in the zinc-aluminum powder is 2: 1-3: 1, and the particle size of zinc to aluminum in the zinc-aluminum powder is 10-20 μm.

8. The surface anticorrosion and antirust treatment process for a rust-preventive agent-free self-tapping screw, according to claim 1, characterized in that: in the step (4) and the step (5), the specific method for drying the tapping screw coated with the chromium-free zinc-aluminum anticorrosive paint comprises the following steps: pre-drying at 120 deg.C for 5-10min, low-temperature curing at 250 deg.C for 1-1.5h, and preventing for over 24h at room temperature until the surface is completely dried.

Technical Field

The invention relates to the technical field of anticorrosive and antirust treatment of surfaces of self-tapping screws, in particular to a surface anticorrosive and antirust treatment process for a self-tapping screw without an antirust agent.

Background

The self-tapping screw is a screw with a drill bit, and drilling, tapping, fixing and locking are completed at one time through construction of a special electric tool. Tapping screw mainly used some thinner plate's connection and fixed, be connected as various steel sheet and various steel sheet, various steel sheet and purlin, the connection of wall roof beam etc, current tapping screw need use the antirust agent just can realize rust-proofly, and the antirust agent of prior art hypertoxic, rust easily under the condition that runs into acid putty powder, when being applied to indoor construction technology with tapping screw, it is when being connected between light gauge steel and the gypsum board very much, the gypsum board surface must brush putty powder, this just leads to adopting the antirust effect commonly used to receive the influence.

The traditional dacromet (zinc-aluminum coating) is used as an effective surface anticorrosion technology of a metal base material and is widely applied to industries such as bridges, automobiles, war industry, ships, wind power and the like. The Dacromet coating liquid contains chromic anhydride and hexavalent chromium compounds remained after the Dacromet coating liquid is solidified into a coating, which can cause great damage to human bodies and the environment. With the enhancement of environmental awareness, more and more countries set corresponding environmental regulations, the use of the Dacromet coating is limited, and the research and development of the water-based chromium-free zinc-aluminum coating liquid are developed vigorously; at present, the chromium-free zinc-aluminum coating liquid is developed and developed by using a water-based epoxy resin, a rare earth metal salt and a silane coupling agent as a novel adhesive, and certain results are obtained. The silanol formed after the silane coupling agent is hydrolyzed can form hydrogen bond adsorption with the metal base material and the flaky zinc-aluminum powder, and meanwhile, the silanol can perform condensation reaction and further condense at high temperature to form a three-dimensional cross-linked network structure of Si-O-Si. The process enables the scaly zinc-aluminum powder, the metal base material and the organic matter formed by the silane coupling agent to be tightly combined into a whole to resist the invasion of corrosive medium.

The invention discloses an antirust and anticorrosive method for a self-tapping screw surface coating by adopting a low-temperature chromium-free zinc-aluminum coating composition, which does not need to use an antirust agent and is more environment-friendly and safer.

Disclosure of Invention

The invention mainly aims to provide a surface anticorrosion and antirust treatment process for a self-tapping screw without an antirust agent, which can effectively solve the problems in the background technology.

In order to achieve the purpose, the invention adopts the technical scheme that:

a surface anticorrosion and antirust treatment process for a rust inhibitor-free self-tapping screw comprises the following specific steps:

step (1), preparing the chromium-free zinc-aluminum anticorrosive paint: preparing raw materials according to the following weight percentages: 30-40% of zinc-aluminum powder, 3-7% of emulsifier, 1-5% of defoamer, 21-25% of silane coupling agent, 3-7% of dispersant, 2-6% of methanol and the balance of deionized water, and mixing the components to prepare the chromium-free zinc-aluminum anticorrosive paint for later use;

step (2), surface degreasing: taking a self-tapping screw, soaking the self-tapping screw in a water-based degreasing agent, stirring by using a stirrer to remove surface oil stains, washing by using clean water, and naturally airing for later use;

step (3), shot blasting: putting the self-tapping screw subjected to oil removal and air drying in the step (2) into a shot blasting machine for shot blasting, and performing surface treatment to improve the surface smoothness of the self-tapping screw;

step (4), dip coating and low-temperature curing: immersing the automatic screw subjected to shot blasting treatment into the chromium-free zinc-aluminum anticorrosive coating prepared in the step (1), uniformly coating the chromium-free zinc-aluminum anticorrosive coating on the surface of the self-tapping screw, taking out, and curing and drying at low temperature of 250 ℃;

step (5), preparing a finished product: and (5) repeating the step (4) for 2-20 times, and drying to obtain the self-tapping screw with the chromium-free zinc-aluminum anticorrosive coating.

Preferably, the specific steps of preparing the chromium-free zinc-aluminum anticorrosive paint in the step (1) are as follows:

step (11): sequentially adding zinc-aluminum powder, an emulsifier, methanol, a defoaming agent and a dispersing agent into a container for mixing and stirring, so that the zinc-aluminum powder, the emulsifier, the methanol, the defoaming agent and the dispersing agent are completely mixed to prepare a mixture A;

step (12): adding a silane coupling agent into deionized water, and continuously stirring until the silane coupling agent and the deionized water are completely mixed to obtain a mixture B;

step (13): and adding the mixture B into the mixture A for three times, uniformly stirring after adding the mixture B each time until all the mixture B is completely added into the mixture A, and stirring and mixing again to obtain the chromium-free zinc-aluminum anticorrosive paint.

Preferably, the antifoaming agent in the step (1) is any one selected from a mineral oil type aqueous antifoaming agent and a solvent oil.

Preferably, the silane coupling agent is any one of gamma-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, and gamma-methacryloxypropyltrimethoxysilane.

Preferably, the emulsifier is selected from one or a combination of several of fatty alcohol-polyoxyethylene ether, fatty acid-polyoxyethylene ester and polyoxyethylene-polyoxypropylene block polyether.

Preferably, the dispersant is any one selected from OP-10, Tween-20 and octadecyl alcohol polyoxyethylene ether.

Preferably, the mass ratio of zinc to aluminum in the zinc-aluminum powder selected in the step (1) is 2: 1-5: 1, the particle size ratio of zinc to aluminum in the zinc-aluminum powder is 2: 1-3: 1, and the particle size of zinc to aluminum in the zinc-aluminum powder is 10-20 μm.

Preferably, in the step (4) and the step (5), the specific method for drying the tapping screw coated with the chromium-free zinc-aluminum anticorrosive paint comprises the following steps: pre-drying at 120 deg.C for 5-10min, low-temperature curing at 250 deg.C for 1-1.5h, and preventing for over 24h at room temperature until the surface is completely dried.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a surface anticorrosion and antirust treatment process for a self-tapping screw without an antirust agent, which adopts a low-temperature curing chromium-free zinc-aluminum coating to form a compact multilayer protective layer on the surface of the self-tapping screw, does not contain hexavalent chromium, has ultralow VOC (volatile organic compounds) emission, does not cause environmental pollution, has environment-friendly performance, has no influence on the mechanical performance of a workpiece, does not need electroplating and priming, avoids hydrogen embrittlement, has salt spray performance of up to 2000 hours, is suitable for connection between a light steel keel and a gypsum board in an indoor process, and has wide application prospect.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood by those skilled in the art that, unless otherwise specified, the singular forms "a", "an", "the" and "the" may include the plural forms as well, and the "first" and "second" used herein are only used to distinguish one technical feature from another and are not intended to limit the order, number, etc. of the technical features. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms), have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that, in the present invention, the emulsifier is selected from one or a combination of several of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, and polyoxyethylene polyoxypropylene block polyether; the dispersing agent is selected from any one of OP-10, Tween-20 and octadecyl alcohol polyoxyethylene ether; the mass ratio of zinc to aluminum in the selected zinc-aluminum powder is 2: 1-5: 1, the particle size ratio of zinc to aluminum in the zinc-aluminum powder is 2: 1-3: 1, and the particle size of zinc to aluminum in the zinc-aluminum powder is 10-20 mu m; the coupling agent adopts any one of gamma-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane and gamma-methacryloxypropyltrimethoxysilane.

Example 1

Step (1), preparing the chromium-free zinc-aluminum anticorrosive paint: preparing raw materials according to the following weight percentages: 30% of zinc-aluminum powder, 3% of an emulsifier, 1% of a defoaming agent, 21% of a silane coupling agent, 3% of a dispersant, 2% of methanol and the balance of deionized water;

sequentially adding the zinc-aluminum powder, the emulsifier, the methanol, the defoaming agent and the dispersant into a container for mixing and stirring, so that the zinc-aluminum powder, the emulsifier, the methanol, the defoaming agent and the dispersant are completely mixed to prepare a mixture A; adding a silane coupling agent into deionized water, continuously stirring until the silane coupling agent is completely mixed to obtain a mixture B, adding the mixture B into the mixture A for three times, uniformly stirring after adding the mixture B each time until all the mixture B is completely added into the mixture A, and stirring and mixing again to obtain the chromium-free zinc-aluminum anticorrosive paint;

step (2), surface degreasing: taking a self-tapping screw, soaking the self-tapping screw in a water-based degreasing agent, stirring by using a stirrer to remove surface oil stains, washing by using clean water, and naturally airing for later use;

step (3), shot blasting: putting the self-tapping screw subjected to oil removal and air drying in the step (2) into a shot blasting machine for shot blasting, and performing surface treatment to improve the surface smoothness of the self-tapping screw;

step (4), dip coating and low-temperature curing: immersing the automatic screw subjected to shot blasting treatment into the chromium-free zinc-aluminum anticorrosive coating prepared in the step (1), uniformly coating the chromium-free zinc-aluminum anticorrosive coating on the surface of the self-tapping screw, taking out the self-tapping screw, pre-drying the self-tapping screw at the temperature of 100 ℃ and 120 ℃ for 5-10min, then carrying out low-temperature curing at the temperature of 250 ℃ for 1-1.5h, and finally preventing the self-tapping screw from being dried for more than 24h at normal temperature until the surface of the self-tapping screw is completely dried;

step (5), preparing a finished product: and (5) repeating the step (4) for 2-20 times, and drying to obtain the self-tapping screw with the chromium-free zinc-aluminum anticorrosive coating.

Example 2

Step (1), preparing the chromium-free zinc-aluminum anticorrosive paint: preparing raw materials according to the following weight percentages: 32 percent of zinc-aluminum powder, 4 percent of emulsifier, 2 percent of defoaming agent, 22 percent of silane coupling agent, 4 percent of dispersant, 3 percent of methanol and the balance of deionized water,

sequentially adding zinc-aluminum powder, an emulsifier, methanol, a defoaming agent and a dispersing agent into a container for mixing and stirring, so that the zinc-aluminum powder, the emulsifier, the methanol, the defoaming agent and the dispersing agent are completely mixed to prepare a mixture A; adding a silane coupling agent into deionized water, continuously stirring until the silane coupling agent is completely mixed to obtain a mixture B, adding the mixture B into the mixture A for three times, uniformly stirring after adding the mixture B each time until all the mixture B is completely added into the mixture A, and stirring and mixing again to obtain the chromium-free zinc-aluminum anticorrosive paint;

step (2), surface degreasing: taking a self-tapping screw, soaking the self-tapping screw in a water-based degreasing agent, stirring by using a stirrer to remove surface oil stains, washing by using clean water, and naturally airing for later use;

step (3), shot blasting: putting the self-tapping screw subjected to oil removal and air drying in the step (2) into a shot blasting machine for shot blasting, and performing surface treatment to improve the surface smoothness of the self-tapping screw;

step (4), dip coating and low-temperature curing: immersing the automatic screw subjected to shot blasting treatment into the chromium-free zinc-aluminum anticorrosive coating prepared in the step (1), uniformly coating the chromium-free zinc-aluminum anticorrosive coating on the surface of the self-tapping screw, taking out the self-tapping screw, pre-drying the self-tapping screw at the temperature of 100 ℃ and 120 ℃ for 5-10min, then carrying out low-temperature curing at the temperature of 250 ℃ for 1-1.5h, and finally preventing the self-tapping screw from being dried for more than 24h at normal temperature until the surface of the self-tapping screw is completely dried;

step (5), preparing a finished product: and (5) repeating the step (4) for 8 times, and drying to obtain the self-tapping screw with the chromium-free zinc-aluminum anticorrosive coating.

Example 3

Step (1), preparing the chromium-free zinc-aluminum anticorrosive paint: preparing raw materials according to the following weight percentages: 34 percent of zinc-aluminum powder, 5 percent of emulsifier, 3 percent of defoamer, 23 percent of silane coupling agent, 5 percent of dispersant, 5 percent of methanol and the balance of deionized water,

sequentially adding zinc-aluminum powder, an emulsifier, methanol, a defoaming agent and a dispersing agent into a container for mixing and stirring, so that the zinc-aluminum powder, the emulsifier, the methanol, the defoaming agent and the dispersing agent are completely mixed to prepare a mixture A; adding a silane coupling agent into deionized water, continuously stirring until the silane coupling agent is completely mixed to obtain a mixture B, adding the mixture B into the mixture A for three times, uniformly stirring after adding the mixture B each time until all the mixture B is completely added into the mixture A, and stirring and mixing again to obtain the chromium-free zinc-aluminum anticorrosive paint;

step (2), surface degreasing: taking a self-tapping screw, soaking the self-tapping screw in a water-based degreasing agent, stirring by using a stirrer to remove surface oil stains, washing by using clean water, and naturally airing for later use;

step (3), shot blasting: putting the self-tapping screw subjected to oil removal and air drying in the step (2) into a shot blasting machine for shot blasting, and performing surface treatment to improve the surface smoothness of the self-tapping screw;

step (4), dip coating and low-temperature curing: immersing the automatic screw subjected to shot blasting treatment into the chromium-free zinc-aluminum anticorrosive coating prepared in the step (1), uniformly coating the chromium-free zinc-aluminum anticorrosive coating on the surface of the self-tapping screw, taking out the self-tapping screw, pre-drying the self-tapping screw at the temperature of 100 ℃ and 120 ℃ for 5-10min, then carrying out low-temperature curing at the temperature of 250 ℃ for 1-1.5h, and finally preventing the self-tapping screw from being dried for more than 24h at normal temperature until the surface of the self-tapping screw is completely dried;

step (5), preparing a finished product: and (5) repeating the step (4) for 15 times, and drying to obtain the self-tapping screw with the chromium-free zinc-aluminum anticorrosive coating.

Example 4

Step (1), preparing the chromium-free zinc-aluminum anticorrosive paint: preparing raw materials according to the following weight percentages: 40 percent of zinc-aluminum powder, 7 percent of emulsifier, 5 percent of defoamer, 25 percent of silane coupling agent, 7 percent of dispersant, 6 percent of methanol and the balance of deionized water,

sequentially adding zinc-aluminum powder, an emulsifier, methanol, a defoaming agent and a dispersing agent into a container for mixing and stirring, so that the zinc-aluminum powder, the emulsifier, the methanol, the defoaming agent and the dispersing agent are completely mixed to prepare a mixture A; adding a silane coupling agent into deionized water, continuously stirring until the silane coupling agent is completely mixed to obtain a mixture B, adding the mixture B into the mixture A for three times, uniformly stirring after adding the mixture B each time until all the mixture B is completely added into the mixture A, and stirring and mixing again to obtain the chromium-free zinc-aluminum anticorrosive paint;

step (2), surface degreasing: taking a self-tapping screw, soaking the self-tapping screw in a water-based degreasing agent, stirring by using a stirrer to remove surface oil stains, washing by using clean water, and naturally airing for later use;

step (3), shot blasting: putting the self-tapping screw subjected to oil removal and air drying in the step (2) into a shot blasting machine for shot blasting, and performing surface treatment to improve the surface smoothness of the self-tapping screw;

step (4), dip coating and low-temperature curing: immersing the automatic screw subjected to shot blasting treatment into the chromium-free zinc-aluminum anticorrosive coating prepared in the step (1), uniformly coating the chromium-free zinc-aluminum anticorrosive coating on the surface of the self-tapping screw, taking out the self-tapping screw, pre-drying the self-tapping screw at the temperature of 100 ℃ and 120 ℃ for 5-10min, then carrying out low-temperature curing at the temperature of 250 ℃ for 1-1.5h, and finally preventing the self-tapping screw from being dried for more than 24h at normal temperature until the surface of the self-tapping screw is completely dried;

step (5), preparing a finished product: and (5) repeating the step (4) for 20 times, and drying to obtain the self-tapping screw with the chromium-free zinc-aluminum anticorrosive coating.

Comparative example 1.

Taking a self-tapping screw, smearing an antirust agent (brand KEM/Kuaimei) and drying for later use.

10 tapping screws subjected to corrosion and rust prevention treatment in examples 1 to 4 and 10 tapping screws coated with a rust inhibitor in comparative example 1 were subjected to a neutral salt spray test according to national standard GB/T10125-2012 (equivalent to international standard ISO 9227: 2006), and corrosion resistance was measured according to the neutral salt spray test, and the test results are shown in the following table;

the data in the table 1 show that the low-temperature curing chromium-free zinc-aluminum coating is adopted to form a compact multilayer protective layer on the surface of the self-tapping screw, the salt spray performance is as high as about 2000 hours, and the corrosion resistance of the self-tapping screw is obviously improved compared with that of the conventional antirust agent.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.