阅读说明：本技术 一种户外铁塔用氟碳粉末涂料及其制备方法 (Fluorocarbon powder coating for outdoor iron tower and preparation method thereof ) 是由 覃世仁 黄河 罗荣合 陈树生 黄东 于 2019-11-25 设计创作，主要内容包括：本发明公开了一种户外铁塔用氟碳粉末涂料及其制备方法,该氟碳粉末涂料由以下重量份数原料制成：聚偏氟乙烯树脂35-45份、聚四氟乙烯树脂8-12份、超耐候聚酯树脂12-16份、脂环族环氧树脂20-30份、丙烯酸树脂12-18份、环氧改性醇酸树脂12-18份、聚六亚甲基胍2-5份、改性石墨烯3-6份、纳米二氧化硅6-10份、纳米三氧化二铝0.5-3份、硫酸钡4-10份、硅烷偶联剂KH-792 1.8-2.4份、硬脂酸钙0.2-0.4份、安息香0.3-0.5份、流平剂0.5-1份、TGIC固化剂4-8份。本发明的氟碳粉末涂料具有优良的机械性能以及超强的耐候性、耐化学性和流平性,应用于户外铁塔具有防开裂、抗老化、使用寿命长的特点,且粉末涂料制备方法简单,可进行工业化生产。(The invention discloses a fluorocarbon powder coating for an outdoor iron tower and a preparation method thereof, wherein the fluorocarbon powder coating is prepared from the following raw materials in parts by weight: 35-45 parts of polyvinylidene fluoride resin, 8-12 parts of polytetrafluoroethylene resin, 12-16 parts of super-weather-resistant polyester resin, 20-30 parts of alicyclic epoxy resin, 12-18 parts of acrylic resin, 12-18 parts of epoxy modified alkyd resin, 2-5 parts of polyhexamethylene guanidine, 3-6 parts of modified graphene, 6-10 parts of nano silicon dioxide, 0.5-3 parts of nano aluminum oxide, 4-10 parts of barium sulfate, 0.2-0.4 part of silane coupling agent KH-7921.8, 0.2-0.4 part of calcium stearate, 0.3-0.5 part of benzoin, 0.5-1 part of flatting agent and 4-8 parts of TGIC curing agent. The fluorocarbon powder coating has excellent mechanical property, super-strong weather resistance, chemical resistance and leveling property, is applied to outdoor iron towers, has the characteristics of cracking resistance, ageing resistance and long service life, and is simple in preparation method and capable of being industrially produced.)

1. the fluorocarbon powder coating for the outdoor iron tower is characterized by being prepared from the following raw materials in parts by weight: 35-45 parts of polyvinylidene fluoride resin, 8-12 parts of polytetrafluoroethylene resin, 12-16 parts of super-weather-resistant polyester resin, 20-30 parts of alicyclic epoxy resin, 12-18 parts of acrylic resin, 12-18 parts of epoxy modified alkyd resin, 2-5 parts of polyhexamethylene guanidine, 3-6 parts of modified graphene, 6-10 parts of nano silicon dioxide, 0.5-3 parts of nano aluminum oxide, 4-10 parts of barium sulfate, 0.2-0.4 part of silane coupling agent KH-7921.8, 0.2-0.4 part of calcium stearate, 0.3-0.5 part of benzoin, 0.5-1 part of flatting agent and 4-8 parts of TGIC curing agent.

2. The fluorocarbon powder coating for the outdoor iron tower as claimed in claim 1, wherein the super weather-resistant polyester resin is prepared by oxygen-isolated polycondensation of the following raw materials in parts by weight: 35-45 parts of 1, 4-cyclohexanedicarboxylic acid, 10-15 parts of hydrogenated bisphenol A, 10-25 parts of polysiloxane, 20-25 parts of hydroxypivalic acid neopentyl glycol monoester, 8-12 parts of 2-butyl-2-ethyl-1, 3-propanediol and 18-22 parts of 1, 3-phthalic acid; the acid value of the super weather-resistant polyester resin is 30-35mgKOH/g, and the softening point is 100-110 ℃.

3. A fluorocarbon powder coating for outdoor iron tower as claimed in claim 1, wherein said cycloaliphatic epoxy resin is cycloaliphatic epoxy resin CER-170.

4. A fluorocarbon powder coating for outdoor iron tower as claimed in claim 1, wherein said barium sulfate is composed of nano-sized high gloss barium sulfate and precipitated barium sulfate in a weight ratio of 1: 1.

5. A fluorocarbon powder coating for outdoor iron tower as claimed in claim 1, characterized in that the preparation method of the fluorocarbon powder coating comprises the following steps:

(1) all the raw materials are put into a high-speed mixing disperser for high-speed dispersion mixing;

(2) and adding the mixture into a screw extruder, fully melting and mixing, then extruding, tabletting, crushing, classifying and screening, and finally sieving by a 500-mesh sieve to obtain the powder coating.

Technical Field

The invention relates to the technical field of coating compositions, in particular to a fluorocarbon powder coating for an outdoor iron tower and a preparation method thereof.

Background

The powder coating is a novel solvent-free 100% solid powder coating, and has the characteristics of no solvent, no pollution, recoverability, environmental protection, energy and resource saving, labor intensity reduction, high mechanical strength of film coating and the like. The fluorocarbon powder coating is a powder coating which takes fluororesin as a main film forming substance, has particularly excellent weather resistance, heat resistance, low temperature resistance and chemical resistance, and has unique non-adhesiveness and low friction. Different from solvent-based coatings, fluorocarbon powder coatings do not contain volatile compounds (VOC), reduce the harm to human bodies, conform to ROHS, do not contain toxic heavy metals, belong to environment-friendly coatings, are catalogue approved products of green coating products officially released by China, are taken as currently recognized super-weather-resistant coating varieties at home and abroad, and have been widely verified in outdoor use performance. However, the inherent defects of the pure fluorocarbon powder coating in the aspects of adhesion, pigment and filler wettability and the like, and the high material cost thereof, make the pure fluorocarbon powder coating slowly progress in market application and popularization.

In recent years, due to the fact that outdoor climate changes are not constant, the use effect and the service life of the traditional anticorrosive paint are seriously tested in a strong acid-base environment, a high-salt fog environment, a high-temperature difference environment and a high-humidity environment, the powder coating is easy to corrode in the strong acid-base and high-salt fog environment, cracks and even fall off are easy to generate due to expansion and contraction in the high-temperature difference environment, and in the damp-heat environment, the powder coating is easy to absorb moisture to form white spots on the surface, so that the use and the appearance performance of the powder coating are affected. Therefore, the existing outdoor powder coating has the defects of poor chemical corrosion resistance, antibacterial property and water resistance, easy cracking, short service life and the like, and the application of the outdoor powder coating in the field of industrial and chemical heavy corrosion resistance is limited.

Disclosure of Invention

The invention aims to provide a fluorocarbon powder coating for an outdoor iron tower and a preparation method thereof, the powder coating takes fluorocarbon resin as a main raw material, and is assisted by a plurality of resins with good compatibility and pigments and fillers to be mixed into a film, the obtained coating has excellent mechanical property and super-strong weather resistance, chemical resistance and leveling property, and the coating has the characteristics of cracking resistance, ageing resistance and long service life when being applied to the outdoor iron tower, and the preparation method of the powder coating is simple and can be used for industrial production.

The technical scheme of the invention is realized in the following mode:

the fluorocarbon powder coating for the outdoor iron tower is prepared from the following raw materials in parts by weight: 35-45 parts of polyvinylidene fluoride resin, 8-12 parts of polytetrafluoroethylene resin, 12-16 parts of super-weather-resistant polyester resin, 20-30 parts of alicyclic epoxy resin, 12-18 parts of acrylic resin, 12-18 parts of epoxy modified alkyd resin, 2-5 parts of polyhexamethylene guanidine, 3-6 parts of modified graphene, 6-10 parts of nano silicon dioxide, 0.5-3 parts of nano aluminum oxide, 4-10 parts of barium sulfate, 0.2-0.4 part of silane coupling agent KH-7921.8, 0.2-0.4 part of calcium stearate, 0.3-0.5 part of benzoin, 0.5-1 part of flatting agent and 4-8 parts of TGIC curing agent.

The super weather-resistant polyester resin is prepared by carrying out oxygen-isolated polycondensation on the following raw materials in parts by weight: 35-45 parts of 1, 4-cyclohexanedicarboxylic acid, 10-15 parts of hydrogenated bisphenol A, 10-25 parts of polysiloxane, 20-25 parts of hydroxypivalic acid neopentyl glycol monoester, 8-12 parts of 2-butyl-2-ethyl-1, 3-propanediol and 18-22 parts of 1, 3-phthalic acid; the acid value of the super weather-resistant polyester resin is 30-35mgKOH/g, and the softening point is 100-110 ℃.

The alicyclic epoxy resin is alicyclic epoxy resin CER-170.

The barium sulfate consists of nanoscale high-gloss barium sulfate and precipitated barium sulfate in a weight ratio of 1: 1.

The preparation method of the fluorocarbon powder coating comprises the following steps:

(1) all the raw materials are put into a high-speed mixing disperser for high-speed dispersion mixing;

(2) and adding the mixture into a screw extruder, fully melting and mixing, then extruding, tabletting, crushing, classifying and screening, and finally sieving by a 500-mesh sieve to obtain the powder coating.

The invention has the beneficial effects that:

the super-weather-resistant polyester resin adopts 1, 4-cyclohexanedicarboxylic acid (1,4-CHDA, hydrogenated terephthalic acid) as a dicarboxylic acid component, and hydrogenated bisphenol A (HBPA) as dihydric alcohol, so that an unstable structure of a benzene ring is eliminated; the neopentyl glycol hydroxypivalate monoester (HPHP) has good weather resistance, and the ester group shielded in the molecule increases the distance between ester bonds, so that the hydrolytic stability is improved. 2-butyl-2-ethyl-1, 3-propanediol (BEPD) as modified dihydric alcohol has good hydrolytic stability, and longer aliphatic side chain increases the hydrophobicity of the resin, thereby greatly improving the weather resistance of the polyester resin. Resins with higher terephthalic acid (TPA) content have better mechanical properties, but have poorer weather resistance; the resin with higher content of isophthalic acid (IPA) has better weather resistance, but has poor mechanical property, and the terephthalic acid and the isophthalic acid are matched and used according to a proper proportion, so that the obtained powder coating has excellent mechanical property and weather resistance. Polysiloxanes have excellent heat resistance, electrical insulation, weather resistance, hydrophobicity, physiological inertia and small surface tension, and also have low viscosity-temperature coefficient and high compression resistance. Polysiloxane is added in the preparation process of the polyester resin, so that the weather resistance, heat resistance and leveling property of the polyester resin can be effectively improved, and the-Si-O-Si-structure can enhance the direct crosslinking effect of the resin and a base material.

The polyvinylidene fluoride resin is the toughest of the fluoroplastics, has tensile strength of more than 39MPa, good impact strength and wear resistance, and extremely good ultraviolet resistance, weather aging resistance, radiation resistance and corrosion resistance. The polytetrafluoroethylene resin has excellent performances such as excellent thermal stability, outstanding chemical inertness, excellent electrical properties and low friction coefficient. The alicyclic epoxy resin contains a large amount of epoxy groups, unsaturated double bonds are not contained in the molecular structure of the alicyclic epoxy resin CER-170, the alicyclic epoxy resin CER-170 has excellent ultraviolet ray resistance and radiation resistance, the viscosity is very low compared with the common bisphenol A epoxy resin, the reactivity is higher compared with other alicyclic epoxy resins, the curing shrinkage of a cured product is small, the dimensional stability is good, the mechanical property is excellent, the bonding strength is high, and the weather resistance and the electrical aging resistance are excellent. The acrylic resin type powder coating has excellent decoration, outdoor weather resistance, ageing resistance, corrosion resistance and pollution resistance, high surface hardness and good flexibility. The epoxy resin modified alkyd resin has excellent weather resistance and chemical resistance; is a low-temperature baking drying type resin for paint.

The fluorocarbon resin migrates to the surface of the coating due to the characteristics thereof when being cured to form a film, so that the coating has the characteristics of excellent weather resistance, acid and alkali resistance, aging resistance, permeation resistance and the like. The polyester resin has good leveling property, and can effectively reduce the surface tension of the coating after the powder coating is melted when being cured into a film, so that the surface defects of pinholes, orange peels and the like are weakened or eliminated, and the appearance effect of the coating is effectively improved; the modified polyester resin has excellent weather resistance, and the-Si-O-Si-structure can enhance the crosslinking effect of the resin and the base material. The epoxy resin has excellent corrosion resistance and super strong adhesive force, and can form good binding force with a metal substrate. The acrylic resin has good flexibility, can improve the tensile strength of the coating, improve the brittleness of the coating and avoid cracking of the coating. The alkyd resin has good wear resistance, and can effectively improve the hardness and wear resistance of the coating. Polyvinylidene fluoride resin, polytetrafluoroethylene resin, super-weather-resistant polyester resin, alicyclic epoxy resin, acrylic resin and epoxy modified alkyd resin are mutually cross-linked and cured to form a highly cross-linked net structure, and the high-strength epoxy resin has excellent mechanical property and chemical resistance.

Polyhexamethylene guanidine is an environment-friendly high-molecular polymer disinfectant, has broad bactericidal spectrum, adsorbs various bacteria and viruses which are usually electronegative, enters cell membranes, inhibits the synthesis of intramembrane liposomes to cause apoptosis, and achieves the optimal bactericidal effect. The polyhexamethylene guanidine is added into the powder coating, so that the anti-corrosion effect of the coating can be enhanced, and the anti-corrosion effect is long.

The nano filler can not only improve the mechanical property of the coating film due to the special nano effect, but also be beneficial to improving the aging resistance, the corrosion resistance, the radiation resistance and the like of the coating film. However, the nano-filler is easy to agglomerate due to small particle size and large surface area, and the silane coupling agent can improve the dispersibility of the nano-filler in resin, avoid agglomeration and enable the filler to be firmly connected on a network structure formed by the resin through the bridging action of the silane coupling agent. The nano silicon dioxide can form a compact three-dimensional network structure between the coatings, and the comprehensive performance of the coatings is improved. The nanometer aluminum oxide is used as a flow aid, so that the fluidization performance of the superfine powder coating can be improved, the obtained coating has good surface smoothness and glossiness, and the storage stability of the coating is improved. Barium sulfate can improve the light resistance, weather resistance, chemical resistance, electrochemical corrosion resistance and the decorative effect of the product, and enhance the impact strength of the coating. The mechanical property, the aging resistance, the weather resistance and the like of the coating can be improved by adding a proper amount of nano-scale precipitated barium sulfate. The high-gloss barium sulfate has good dispersibility and affinity with other media, has good compatibility with all pigments, can enhance the leveling property and gloss retention of the powder coating, can improve the optimal film thickness of the powder coating in a spraying process, improves the powdering rate and reduces the using amount of the powder coating. The high-gloss barium sulfate can replace partial precipitated barium sulfate, titanium dioxide, active silicon dioxide and other high-price raw materials, and is an environment-friendly material capable of absorbing harmful rays. Graphene can form a physical barrier layer between metal and a corrosive medium to prevent diffusion and permeation, meanwhile, a stable Sp2 hybrid structure of graphene can effectively block gas atoms from passing through, and graphene also has good thermal stability, chemical stability, strength and friction performance, and can be kept stable under high-temperature environment conditions (1500 ℃) or corrosive gas and liquid conditions. The modified graphene has good dispersibility, and can effectively improve the corrosion resistance and the antifouling performance of the coating in the coating.

The calcium stearate is used as a stabilizer, has excellent lubricity, and can effectively improve the thermal stability and the adhesive force of the coating. The silane coupling agent and the calcium stearate jointly act on the fluorocarbon powder coating, so that the connection among all groups is tighter, the internal appearance of the powder coating is improved, and the uniformity of the coating process and the weather resistance of a coating film are facilitated. The fluorocarbon resin has high carbon-fluorine bond energy, acrylic acid contains hydroxyl and carboxyl, alicyclic epoxy resin contains a large number of epoxy groups, and the resin, the modified graphene, the nano silicon dioxide, the nano aluminum oxide, the barium sulfate and the silane coupling agent have synergistic effect to realize the cross-linking and curing among the groups, realize a highly cross-linked network structure, improve the adhesive force of the coating and reduce the powder falling phenomenon.

Detailed Description

In order to describe the present invention in more detail, the present invention will be further described with reference to the following examples.