Chlorinated rubber finish paint and preparation method thereof

Abstract

The invention discloses chlorinated rubber finish paint and a preparation method thereof. The chlorinated rubber finish paint is prepared from chlorinated rubber, alkyd resin, bisphenol A epoxy resin, a stabilizer, a flexibilizer, a solvent, a defoaming agent, a wetting dispersant, a rheological control aid, pigment and filler, the oil content of the alkyd resin is 60-70%, and the epoxy equivalent of the bisphenol A epoxy resin is 180-210 g / mol. According to the invention, the flexibility, impact resistance, adhesive force, corrosion resistance, weather resistance and glossiness of the chlorinated rubber finish paint can be improved, and the chlorinated rubber finish paint is suitable for long-acting protection of parts above ship waterlines, bridges, chemical equipment, steel structures and the like.

Description

Technical Field

[0001] The invention belongs to the field of coatings, and in particular relates to a chlorinated rubber topcoat and a preparation method thereof. Background Art

[0002] Polyurethane paint, epoxy paint, chlorinated rubber paint, etc. are often used for surface protection of parts above the waterline of ships, bridges, chemical equipment, steel structures, etc. Among them, chlorinated rubber topcoat is a single-component coating, which is widely used due to its stable storage, convenient construction, and good recoatability. However, chlorinated rubber topcoat still has some shortcomings in practical applications, such as low gloss, poor adhesion, corrosion resistance and weather resistance. It is easy to change color when exposed to harsh environments for a long time, and it cannot effectively resist the erosion of seawater, salt spray, and ultraviolet rays. It also has poor flexibility, especially at a higher construction film thickness, the flexibility and impact resistance are significantly reduced.

[0003] Patent CN113881267A improves the adhesion and water resistance of chlorinated rubber anticorrosive paint by grafting acrylate monomers with hydrophilic groups into chlorinated rubber and controlling the mass ratio of chlorinated rubber, acrylate monomers and thickener to 1:0.2~0.5:0.1~0.3. Patent CN109161316A improves the adhesion by using alkyd resin made of specific components such as soybean oil, lithium hydroxide, pentaerythritol, benzoic acid, phthalic anhydride, tung oil, xylene and butyl ester and specific 5130PP adhesion promoter. However, the above patents do not improve the flexibility and weather resistance of chlorinated rubber paint.

[0004] Therefore, there is an urgent need to develop a high-adhesion chlorinated rubber topcoat that can enhance the flexibility and impact resistance of the paint film, as well as improve the corrosion resistance, weather resistance and glossiness, so as to extend the life of the paint film and achieve a long-term protective effect. Summary of the invention

[0005] In view of the above problems, the present invention provides a chlorinated rubber topcoat and a preparation method thereof. The chlorinated rubber topcoat of the present invention is prepared from chlorinated rubber, alkyd resin, bisphenol A type epoxy resin, stabilizer, toughening agent, solvent, defoamer, wetting dispersant, rheology control additive, pigment and filler, the oil content of the alkyd resin is 60-70%, the epoxy equivalent of the bisphenol A type epoxy resin is 180-210 g / mol, and the flexibility, impact resistance, adhesion, corrosion resistance, weather resistance and glossiness of the chlorinated rubber topcoat can be improved, and the chlorinated rubber topcoat is suitable for long-term protection of parts above the waterline of ships, bridges, chemical equipment, steel structures, etc.

[0006] The technical scheme of the present invention is: a chlorinated rubber topcoat, characterized in that it is compounded from the following components in parts by weight: 15-20 parts of chlorinated rubber, 10-15 parts of alkyd resin, 0.3-5 parts of bisphenol A epoxy resin, 3-6 parts of toughening agent, 15-25 parts of solvent, 0.1-0.4 parts of defoaming agent, 0.5-0.8 parts of wetting dispersant, 2-5 parts of rheology control additive, 20-25 parts of pigment, 10-15 parts of filler and 0.5-3 parts of stabilizer.

[0007] Preferably, the chlorine content in the chlorinated rubber is 64-68%. The introduction of chlorine atoms in the chlorinated rubber helps to improve the performance of the coating. The increase in chlorine content increases the number of saturated bonds in the molecular structure of the chlorinated rubber, which can enhance the rigidity and density of the molecular chain in the molecular structure of the chlorinated rubber, improve the saturation and stability of the chlorinated rubber molecules, and help enhance the corrosion resistance and weather resistance of the topcoat, the adhesion between the topcoat and the substrate, the anti-deformation ability of the coating, and balance the hardness and toughness of the resin molecules. The chlorinated rubber used in the embodiment of the present invention is further selected from one or more of S-20, CRF10, CRF20, CR-10 or CR-20.

[0008] Preferably, the alkyd resin is a long-oil alkyd resin with an oil content of 60-70%. The alkyd resin has a high glossiness. By cooperating with bisphenol A epoxy resin and chlorinated rubber, the coating surface is made smoother and more delicate, which improves the glossiness of the coating to a certain extent and enhances the decorative effect of the coating. The alkyd resin used in the embodiment of the present invention is further selected from one or more of QT-6380, 389-9B, GL3303, and RV8111.

[0009] Preferably, the epoxy equivalent of the bisphenol A epoxy resin is 180-210 g / mol. Based on the chlorinated rubber topcoat provided by the present invention, the specific epoxy equivalent helps to enhance the crosslinking density of the bisphenol A epoxy resin, the alkyd resin and the chlorinated rubber, and enhance the adhesion, corrosion resistance, weather resistance and stability of the paint film. The epoxy equivalent of the bisphenol A epoxy resin is reduced, which will lead to too fast a curing speed, shrinkage stress, and affect the flatness and adhesion of the coating; the epoxy equivalent is too high, and the degree of crosslinking of the bisphenol A epoxy resin is too low, which cannot play a role in improving adhesion, corrosion resistance and weather resistance. The bisphenol A epoxy resin used in the embodiment of the present invention is further selected from one or more of E-51, E-55, Epon Resin 828 (Epon 828), and DER331.

[0010] Preferably, the stabilizer is a compound of zinc oxide and bisphenol A polyoxyethylene ether (BPE), and the mass ratio of the two is 3 to 5: 1. The bisphenol A polyoxyethylene ether used in the embodiment of the present invention is selected from one or both of BPE-6 and BPE-10.

[0011] Preferably, the toughening agent is a compound of 52# chlorinated paraffin and polyvinyl acetate (PVAc), and the mass ratio of the two is 2 to 5: 1. The polyvinyl acetate used in the embodiment of the present invention is selected from one or more of PVAc 234K, PVAc 195K or PVAc 189K.

[0012] Preferably, the wetting and dispersing agent is a high molecular weight modified polyurethane dispersant, and in the embodiment of the present invention, is selected from one or more of EFKA4063, Anjeka-6161A, and BYK-163.

[0013] Preferably, the defoaming agent is a fluorine-containing modified foam-breaking polysiloxane solution, which is selected from one or more of BYK-066N, BYK-065 or NEO-5608 in the embodiment of the present invention.

[0014] Preferably, the rheology control agent is a compound of organic modified bentonite and polyamide wax powder, and the mass ratio of the two is 1: 1 to 4. In the embodiment of the present invention, the organic modified bentonite is selected from one or more of Bentone 828, Bentone SD-2, Bentone 27 or Bentone 34, and the polyamide wax powder is selected from one or more of SUPER, RC-800, MT6650, and PA-8600.

[0015] Preferably, the pigment is selected from one or more of titanium dioxide, phthalocyanine pigment (phthalocyanine blue or phthalocyanine green) or iron oxide pigment (iron oxide red, iron oxide yellow or iron oxide black); the filler is selected from one or more of mica powder, talcum powder and graphite powder; the solvent is one or more of xylene, butyl acetate, propylene glycol methyl ether acetate and heavy aromatic hydrocarbons.

[0016] The present invention also provides a method for preparing a chlorinated rubber topcoat, comprising the following steps: S1: Add solvent, alkyd resin, bisphenol A epoxy resin, toughening agent, defoaming agent and wetting dispersant into a dispersion tank, adjust the speed to 800-1500r / min, and stir for 10-20min; S2: Add rheology control agent, filler, pigment and stabilizer, stir evenly and transfer to grinder for grinding until the fineness is less than 40µm to form slurry; S3: Add the slurry and chlorinated rubber into a dispersion tank, adjust the rotation speed to 800-1000 r / min, stir for 15-20 min, adjust the viscosity to 100-110 KU, and filter to obtain the chlorinated rubber topcoat.

[0017] Chlorinated rubber, as the main film-forming substance of chlorinated rubber topcoat, gives chlorinated rubber topcoat certain water resistance, chemical resistance, mildew resistance, wear resistance and scratch resistance. However, this paint film is hard and brittle, and is sensitive to temperature, organic solvents, grease, etc. The gloss, solid content, flexibility, impact resistance, weather resistance and corrosion resistance of the topcoat are relatively low, the decorative effect is poor, and it is easy to fade, which increases the difficulty and cost of construction.

[0018] In view of the above problems, the present invention adopts alkyd resin, bisphenol A epoxy resin and chlorinated rubber to compound, and through the synergistic effect, the flexibility and impact resistance of the chlorinated rubber topcoat are improved, and the weather resistance and corrosion resistance of the overall coating are also improved, which can better resist the erosion of chemical substances such as acids, alkalis, and salts, and enhance its ability to resist the erosion of natural factors such as ultraviolet rays, wind and rain, and extend the service life of the coating. The molecular structures of alkyd resin and bisphenol A epoxy resin both contain polar functional groups. After compounding with chlorinated rubber, these functional groups can form chemical bonds with polar groups on the surfaces of various substrates such as metals and concrete, thereby enhancing the adhesion between the coating and the substrate.

[0019] Other raw materials and functions: Stabilizer: zinc oxide and bisphenol A polyoxyethylene ether compound. Chlorinated rubber is a highly chlorinated polymer, containing a large number of chlorine atoms and active groups in the molecule. During the storage and curing process, chlorinated rubber topcoat will generate HCl due to the effects of high temperature and moisture, and form double bonds in the molecule to cross-link, releasing heat to increase the temperature of the paint film and increase the viscosity until it gels. Zinc oxide is usually used as a stabilizer for chlorinated rubber topcoat, but due to its strong polarity and high surface energy, zinc oxide is not easy to disperse evenly, which can easily lead to unstable performance in local areas, particle agglomeration, precipitation and other phenomena, affecting the adhesion and corrosion resistance of the paint film. After the introduction of bisphenol A polyoxyethylene ether, the longer polyoxyethylene chains in its molecular structure fully extend in the system and surround the zinc oxide particles, preventing the zinc oxide particles from approaching and aggregating with each other. In addition, the hydrophilic oxyethylene ether segments and hydrophobic bisphenol A groups contained in bisphenol A polyoxyethylene ether improve the surface properties of zinc oxide and the surface tension of chlorinated rubber topcoat, making it easier for the system to wrap and disperse the zinc oxide particles, reducing the aggregation tendency of zinc oxide particles, and allowing zinc oxide to always remain dispersed in the chlorinated rubber topcoat. In addition, based on the chlorinated rubber topcoat provided by the present invention, the addition of bisphenol A polyoxyethylene ether forms a strong chemical bond with the surface of the substrate, thereby enhancing the adhesion between the chlorinated rubber topcoat and the substrate. Bisphenol A polyoxyethylene ether has good compatibility with chlorinated rubber and can fill the gaps between chlorinated rubber molecules by participating in the film-forming process, making the formed paint film more uniform and dense, thereby improving the mechanical strength, weather resistance and chemical corrosion resistance of the paint film. When used for surface protection of facilities such as ships and bridges that are exposed to harsh environments for a long time, it can effectively resist the erosion of seawater, salt spray and ultraviolet rays.

[0020] Toughening agent: 52# chlorinated paraffin as a toughening agent can be inserted between chlorinated rubber molecular chains, increase the distance between molecular chains, reduce the force between molecular chains, make chlorinated rubber molecular chains easier to move, thereby improving the flexibility and tensile strength of the topcoat, but under high construction film thickness, the intermolecular movement slows down, the hardness increases, it is difficult to maintain flexibility, and it is easy to become brittle and crack. The introduction of polyvinyl acetate in the toughening agent of the present invention can effectively disperse the stress generated in the coating, improve the toughness of the coating, and synergize with 52# chlorinated paraffin. When the topcoat is impacted, the flexibility of 52# chlorinated paraffin can absorb part of the impact energy. At the same time, the plasticizing effect of polyvinyl acetate can make the topcoat better disperse and transmit the impact stress, avoid stress concentration leading to cracking or damage of the topcoat, improve the flexibility of the chlorinated rubber topcoat, and maintain excellent flexibility even under high construction film thickness, improve the impact resistance and crack resistance of the paint film, and it is not easy to become brittle and crack. Polyvinyl acetate has strong adhesion and film-forming properties. When combined with 52# chlorinated paraffin, it further enhances the adhesion between the coating and the substrate, improves anti-sagging properties, and together improves the coating's construction performance, the uniformity, stability and density of the paint film, and effectively avoids sedimentation and stratification, further enhancing the aging resistance of the paint film.

[0021] Wetting dispersant: It is a high molecular weight modified polyurethane dispersant, which shows excellent wettability and fluidity in the system of the present invention, significantly improves the wetting performance of the coating on the substrate surface, helps the coating to spread better on the substrate surface, reduces the generation of defects such as bubbles and pinholes, prevents flocculation and precipitation through steric hindrance, effectively reduces the viscosity of the coating, makes the pigment evenly dispersed in the coating system, improves the hiding power, tinting power and glossiness of the coating, and reduces the problems of floating color and flowery. In addition, the molecular chain of the high molecular weight modified polyurethane dispersant is relatively long, and entanglement and interweaving occur during the curing process of the chlorinated rubber topcoat provided by the present invention, forming a mesh structure, enhancing the strength and toughness of the paint film, and further enhancing the adhesion between the coating and the substrate by penetrating into the tiny pores and cracks on the surface of the substrate.

[0022] Defoamer: a fluorine-modified foam-breaking polysiloxane solution. The fluorine groups contained in the fluorine-modified foam-breaking polysiloxane solution form a low-energy protective film on the molecular surface, which can reduce the surface tension of the fluorine-modified polysiloxane solution, improve the wettability to the substrate, and quickly penetrate into the foam and destroy its stability, so that the foam quickly dissipates, thereby improving the smoothness and glossiness of the coating. In the chlorinated rubber topcoat provided by the present invention, the fluorine-modified foam-breaking polysiloxane solution enhances the chemical stability and durability of the coating, and reduces the degradation and failure of the coating caused by environmental factors.

[0023] Rheology control additive: a compound of organic modified bentonite and polyamide wax powder. Organic modified bentonite has good dispersibility and anti-settling properties in the coating, effectively preventing the sagging phenomenon during the construction of chlorinated rubber topcoat. The compounding of organic modified bentonite and polyamide wax powder can further improve the thixotropy and anti-sagging properties of chlorinated rubber topcoat, reduce sagging and dripping, improve construction properties and film-forming properties, and balance the effects on gloss and adhesion.

[0024] Fillers: The fillers of the present invention are all flaky fillers, which form a tight shielding layer in the coating to effectively prevent the penetration of moisture, oxygen and corrosive media, improve the anti-corrosion performance of the coating, enhance the overall adhesion of the coating, and improve the hardness and wear resistance of the coating.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention adopts alkyd resin, bisphenol A epoxy resin and chlorinated rubber to compound, and through the synergistic effect, the flexibility, impact resistance, weather resistance and corrosion resistance of the chlorinated rubber topcoat are improved, and the service life of the coating is extended. The molecular structure of alkyd resin and bisphenol A epoxy resin both contain polar functional groups. After compounding with chlorinated rubber, these functional groups can form chemical bonds with polar groups on the surface of various substrates such as metals and concrete, thereby enhancing the adhesion between the coating and the substrate. Experiments have shown that after the alkyd resin with an oil content of 60-70% and the bisphenol A epoxy resin with an epoxy equivalent of 180-210g / mol are compounded with chlorinated rubber, the gloss and flexibility of the paint film are significantly improved, and the adhesion, mechanical strength, weather resistance and chemical corrosion resistance and other properties are enhanced.

[0026] 2. The chlorinated rubber topcoat provided by the present invention introduces bisphenol A polyoxyethylene ether and zinc oxide as a stabilizer, which enhances the stability of the chlorinated rubber and avoids the phenomenon of particle agglomeration and precipitation caused by uneven dispersion of zinc oxide, which leads to unstable performance in local areas. The addition of bisphenol A polyoxyethylene ether also enhances the adhesion between the chlorinated rubber topcoat and the substrate by forming a strong chemical bond with the surface of the substrate. In addition, bisphenol A polyoxyethylene ether has good compatibility with chlorinated rubber, participates in the film-forming process, and can fill the gaps between chlorinated rubber molecules, making the formed paint film more uniform and dense, and improving the mechanical strength, weather resistance and chemical corrosion resistance of the paint film. Experiments have proved that zinc oxide and bisphenol A polyoxyethylene ether are used in a specific ratio in the chlorinated rubber topcoat provided by the present invention, showing good flexibility, corrosion resistance and weather resistance.

[0027] 3. The chlorinated rubber topcoat provided by the present invention introduces polyvinyl acetate and 52# chlorinated paraffin as a toughening agent, which enhances the flexibility of the paint film, and can maintain excellent flexibility even at a higher construction film thickness, and improves the impact resistance and crack resistance of the paint film. Polyvinyl acetate with strong adhesion and film-forming properties is further compounded with 52# chlorinated paraffin to enhance the adhesion between the coating and the substrate, improve the anti-sagging property, improve the construction performance of the coating, and effectively avoid sedimentation and stratification, improve the uniformity, stability and density of the paint film, and further enhance the aging resistance of the paint film. Experiments have shown that the specific ratio of polyvinyl acetate and 52# chlorinated paraffin can maintain the excellent flexibility of the paint film, improve the impact resistance of the paint film, and enhance the adhesion between the coating and the substrate.

[0028] In summary, the present invention adopts alkyd resin, bisphenol A epoxy resin and chlorinated rubber as film-forming resin, and compound them with specific amounts of stabilizers, toughening agents, defoamers, wetting dispersants, rheology control additives, pigments, fillers and other additives to obtain chlorinated rubber topcoat, the oil content of the alkyd resin is 60-70%, the epoxy equivalent of the bisphenol A epoxy resin is 180-210 g / mol, the stabilizer is zinc oxide and bisphenol A polyoxyethylene ether compounded at a ratio of 3-5:1 (mass ratio), and the toughening agent is 52# chlorinated paraffin and polyvinyl acetate compounded at a ratio of 2-5:1 (mass ratio), the flexibility, impact resistance, adhesion, corrosion resistance, weather resistance and gloss of the chlorinated rubber topcoat are improved. The chlorinated rubber topcoat is suitable for long-term protection of parts above the waterline of ships, bridges, chemical equipment, steel structures, etc. DETAILED DESCRIPTION

[0029] The effects are described below with reference to embodiments.

[0030] Embodiment 1: S1: Add 20 parts of xylene (solvent), 15 parts of QT-6380 (alkyd resin), 2 parts of E-51 (bisphenol A epoxy resin), 2 parts of DER 331 (bisphenol A epoxy resin), 2 parts of 52# chlorinated paraffin, 1 part of PVAc 234K (polyvinyl acetate), 0.3 parts of BYK-066N (defoaming agent), and 0.6 parts of BYK-163 (wetting and dispersing agent) into the dispersion tank in sequence, adjust the speed to 1200r / min, and stir for 15min; S2: Add 1 part of Bentone 828 (organic modified bentonite), 1 part of SUPER (polyamide wax powder), 13 parts of mica powder, 10 parts of titanium dioxide, 12 parts of black iron oxide, 0.4 parts of zinc oxide, and 0.1 parts of BPE-6 (bisphenol A polyoxyethylene ether) in sequence, stir evenly, and then transfer to a grinder for grinding until the fineness is less than 40µm to form a slurry; S3: Add the slurry and 9 parts of CRF10 (chlorinated rubber, Ruize Chemical Co., Ltd.) and 9 parts of CR-20 (chlorinated rubber) into a dispersion tank, adjust the speed to 900 r / min, stir for 18 minutes, adjust the viscosity to 105 KU, and filter to obtain the chlorinated rubber topcoat.

[0031] Embodiment 2: S1: Add 7 parts of butyl acetate (solvent), 8 parts of propylene glycol methyl ether acetate (solvent), 5 parts of GL3303 (alkyd resin), 5 parts of 389-9B (alkyd resin), 0.3 parts of E-55 (bisphenol A epoxy resin), 5 parts of 52# chlorinated paraffin, 1 part of PVAc195K (polyvinyl acetate), 0.1 parts of NEO-5608 (defoaming agent), 0.2 parts of EFKA4063 (wetting and dispersing agent), and 0.3 parts of Anjeka-6161A (wetting and dispersing agent) into the dispersion tank in sequence, adjust the speed to 800r / min, and stir for 10min; S2: Add 1 part of Bentone SD-2 (organic modified bentonite), 3 parts of RC-800 (polyamide wax powder), 5 parts of talc, 5 parts of graphite powder, 25 parts of titanium dioxide, 2.1 parts of zinc oxide, and 0.7 parts of BPE-10 (bisphenol A polyoxyethylene ether) in sequence, stir evenly, and then transfer to a grinder for grinding until the fineness is less than 40µm to form a slurry; S3: Add the slurry and 15 parts of S-20 (chlorinated rubber) into a dispersion tank, adjust the rotation speed to 800 r / min, stir for 15 minutes, adjust the viscosity to 100 KU, and filter to obtain the chlorinated rubber topcoat.

[0032] Embodiment 3: S1: Add 25 parts of S-800# (heavy aromatic solvent), 7 parts of GL3303 (alkyd resin), 7 parts of RV8111 (alkyd resin), 5 parts of Epon Resin 828 (bisphenol A epoxy resin), 3 parts of 52# chlorinated paraffin, 0.5 parts of PVAc 195K (polyvinyl acetate), 0.5 parts of PVAc 189K (polyvinyl acetate), 0.2 parts of BYK-065 (defoaming agent), 0.2 parts of NEO-5608 (defoaming agent), and 0.8 parts of BYK-163 (wetting and dispersing agent) into the dispersion tank in sequence, adjust the speed to 1500r / min, and stir for 20min; S2: add 1 part of Bentone 27 (organic modified bentonite), 2 parts of MT6650 (polyamide wax powder), 2 parts of PA-8600 (polyamide wax powder), 15 parts of mica powder, 10 parts of phthalocyanine blue, 10 parts of black iron oxide, 2.5 parts of zinc oxide, 0.3 parts of BPE-6 (bisphenol A polyoxyethylene ether), 0.2 parts of BPE-10 (bisphenol A polyoxyethylene ether) in sequence, stir evenly and transfer to a grinder for grinding until the fineness is less than 40µm to form a slurry; S3: Add the slurry and 10 parts of CR-10 (chlorinated rubber) and 10 parts of CRF20 (chlorinated rubber, Ruize Chemical Co., Ltd.) into a dispersion tank, adjust the speed to 1000 r / min, stir for 20 minutes, adjust the viscosity to 110 KU, and filter to obtain the chlorinated rubber topcoat.

[0033] Comparative Example 1: The only difference between this comparative example and Example 1 is that this comparative example uses equal amounts (equal weight parts, the same below) of chlorinated rubber CRF10 to replace alkyd resin QT-6380, bisphenol A epoxy resin E-51 and DER 331, respectively.

[0034] Comparative Example 2: The difference between this comparative example and Example 1 is that the alkyd resin QT-6906 with an oil content of 35-45% is used to replace the alkyd resin QT-6380; and the bisphenol A epoxy resin DER 332 with an epoxy equivalent of 171-175 g / mol is used to replace the bisphenol A epoxy resin E-51 and DER 331.

[0035] Comparative Example 3: The difference between this comparative example and Example 1 is that the bisphenol A polyoxyethylene ether BPE-6 is replaced by an equal amount of zinc oxide in this comparative example.

[0036] Comparative Example 4: The difference between this comparative example and Example 1 is that in Comparative Example 4, 0.1 parts of zinc oxide and 0.4 parts of BPE-6 are added.

[0037] Comparative Example 5: The difference between this comparative example and Example 1 is that in Comparative Example 5, 1 part of 52# chlorinated paraffin and 2 parts of PVAc234K are added.

[0038] Comparative Example 6: The difference between this comparative example and Example 1 is that, in Comparative Example 6, 10 parts of 52# chlorinated paraffin are used, and polyvinyl acetate PVAc 234K is not added.

[0039] The performance indicators of the chlorinated rubber topcoats of Examples 1 to 3 and Comparative Examples 1 to 6 were observed and measured (product implementation standard: GB / T6745-2008 "Hull Paint"), and the results are shown in Table 1.

[0040] Table 1 Test results of chlorinated rubber topcoat performance

[0041]

[0042] The test results in Table 1 show that Examples 1 to 3 provide a chlorinated rubber topcoat with good flexibility, strong impact resistance, corrosion resistance, weather resistance, high gloss and good adhesion, which is suitable for surface protection of parts above the waterline of ships, bridges, chemical equipment, steel structures, etc., and prolongs the service life of the paint film.

[0043] Compared with Comparative Examples 1 and 2, Example 1 shows that after the alkyd resin with an oil content of 60-70% and the bisphenol A epoxy resin with an epoxy equivalent of 180-210 g / mol are compounded with chlorinated rubber, the gloss and flexibility of the paint film are significantly improved, and the adhesion, mechanical strength, weather resistance and chemical corrosion resistance and other properties are enhanced.

[0044] Comparison of Example 1 with Comparative Examples 3 and 4 shows that the chlorinated rubber topcoat provided by the present invention exhibits good flexibility, corrosion resistance and weather resistance when zinc oxide and bisphenol A polyoxyethylene ether are compounded in a specific ratio. Not using bisphenol A polyoxyethylene ether or changing the ratio of bisphenol A polyoxyethylene ether and zinc oxide will affect the flexibility, salt water resistance, salt spray resistance, artificial weathering resistance, weather resistance and other properties of the paint film.

[0045] Comparison of Example 1 with Comparative Examples 5 and 6 shows that the specific ratio of polyvinyl acetate and 52# chlorinated paraffin can maintain the excellent flexibility of the paint film, improve the impact resistance of the paint film, and enhance the adhesion between the coating and the substrate. Not using polyvinyl acetate or changing the ratio of polyvinyl acetate and 52# chlorinated paraffin will affect the excellent flexibility and impact resistance of the paint film and the adhesion between the coating and the substrate.

Claims

1. A chlorinated rubber topcoat, characterized in that: The invention is compounded from the following components in parts by weight: 15-20 parts of chlorinated rubber, 10-15 parts of alkyd resin, 0.3-5 parts of bisphenol A epoxy resin, 3-6 parts of toughening agent, 15-25 parts of solvent, 0.1-0.4 parts of defoaming agent, 0.5-0.8 parts of wetting and dispersing agent, 2-5 parts of rheology control agent, 20-25 parts of pigment, 10-15 parts of filler and 0.5-3 parts of stabilizer. The alkyd resin is a long oil alkyd resin with an oil content of 60-70%; The epoxy equivalent of the bisphenol A epoxy resin is 180-210 g / mol.

2. The chlorinated rubber topcoat according to claim 1, characterized in that: The stabilizer is a compound of zinc oxide and bisphenol A polyoxyethylene ether, and the mass ratio of the two is 3-5:1; The toughening agent is a compound of 52# chlorinated paraffin and polyvinyl acetate, and the mass ratio of the two is 2-5:

1.

3. The chlorinated rubber topcoat according to claim 1, characterized in that: The chlorine content in the chlorinated rubber is 64-68%.

4. The chlorinated rubber topcoat according to claim 1, characterized in that: The wetting dispersant is a high molecular weight modified polyurethane dispersant.

5. The chlorinated rubber topcoat according to claim 1, characterized in that: The rheology control additive is a compound of organic modified bentonite and polyamide wax powder, and the mass ratio of the two is 1:1-4.

6. The chlorinated rubber topcoat according to claim 1, characterized in that: The pigment is selected from at least one of titanium dioxide, phthalocyanine pigment or iron oxide pigment; The filler is selected from at least one of mica powder, talc powder and graphite powder.

7. The chlorinated rubber topcoat according to claim 1, characterized in that: The solvent is at least one of xylene, butyl acetate, propylene glycol methyl ether acetate, and heavy aromatic hydrocarbons.

8. The method for preparing the chlorinated rubber topcoat according to any one of claims 1 to 7, characterized in that: The steps include: S1: Add solvent, alkyd resin, bisphenol A epoxy resin, toughening agent, defoaming agent and wetting dispersant into a dispersion tank for stirring and dispersing; S2: Add rheology control agent, filler, pigment and stabilizer, stir evenly and transfer to grinder for grinding until the fineness is less than 40µm to form slurry; S3: Add the slurry and chlorinated rubber into a dispersion tank, stir and disperse, adjust the viscosity to 100-110KU, and filter to obtain the chlorinated rubber topcoat.

9. The method for preparing the chlorinated rubber topcoat as claimed in claim 8, characterized in that: The stirring and dispersing in step S1 is as follows: adjusting the rotation speed to 800-1500 r / min and stirring for 10-20 min.

10. The method for preparing the chlorinated rubber topcoat as claimed in claim 8, characterized in that: The stirring and dispersing in step S3 is as follows: adjusting the rotation speed to 800-1000 r / min and stirring for 15-20 min.

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