High-flash-point alkyd protective paint and preparation method thereof

Abstract

The invention discloses a high-flash-point alkyd protective coating and a preparation method thereof, the coating is a single-component product and specifically comprises high-flash-point alkyd resin, mixed alkane / aromatic solvent oil, pigment, filler, bentonite, a dispersing agent, a drier, an anti-skinning agent and the like. The coating has the advantages of high flash point (67-70 DEG C), high drying speed, yellowing resistance, impact resistance, brine resistance, excellent adhesive force, high solid content, low VOC content and the like, and can be stored and transported as common goods.

Description

Technical Field

[0001] The invention relates to the technical field of alkyd coatings, and in particular to a high-flash point alkyd protective coating and a preparation method thereof. Background Art

[0002] Alkyd resin coating is a type of industrial protective coating with vegetable oil as the main raw material. Due to its advantages such as low material cost, renewability, convenient construction, and good comprehensive protective performance, it has become one of the coating categories with the highest output (accounting for about 20% of the total coating output) and is widely used in the decoration and protection of building steel structures, engineering vehicles, mechanical equipment, inland ships and wooden products.

[0003] Flash point refers to the lowest temperature at which the flammable gas formed by the vapor generated on the surface of a volatile liquid mixed with air at a certain temperature can flash when it encounters a fire source. In the storage, transportation and use of chemicals, the flash point is an important indicator for judging the safety of materials. According to GB 6944 "Classification and Name Numbering of Dangerous Goods" and JT / T 617 "Rules for Road Transport of Dangerous Goods", liquid substances, liquid mixtures or liquid substances containing solid substances with a closed cup test flash point of ≤60°C are collectively referred to as flammable liquids. Traditional solvent-based alkyd resin coatings use a large amount of low flash point materials, and their closed cup test flash point is between 27 and 40°C, which is a flammable liquid chemical. As for flammable liquid chemicals, their transportation must be strictly carried out in accordance with relevant regulations, such as specific dangerous goods transportation routes, qualifications of transportation personnel (drivers, escorts), vehicle requirements, supervision requirements, and emergency response plan review. In addition, in terms of storage environment, specially designed sturdy, fireproof, and explosion-proof buildings are also required, equipped with precise temperature and humidity control, leakage and penetration prevention, comprehensive and real-time monitoring systems and other equipment.

[0004] As the country increases its safety control over chemical-related industries, the flammability of traditional low-flash point (27-40°C) solvent-based alkyd resin coatings has become increasingly prominent. How to improve the flash point of coatings to improve their safety is an important direction for the current development of solvent-based alkyd resin coatings. To date, a number of "high-flash point" solvent-based alkyd coatings have been launched on the market, but due to the traditional technical route, the defects of this type of product are quite obvious. The main problems are: (1) The solvent evaporates too slowly, and the surface drying and actual drying time of the coating are greatly extended; (2) The iodine value of the resin is not properly selected, and the coating has poor yellowing resistance; (3) The introduction of emulsified water to adjust the flash point makes the coating highly hydrophilic and poorly resistant to salt water; (4) The flash point is falsely marked, and the actual measured flash point does not meet the standard (40-60°C).

[0005] In summary, the present invention aims to provide a quick-drying, high-performance, high-flash point alkyd protective coating solution to overcome the technical defects of current commercially available products, increase the market penetration rate of safety coatings, and achieve a win-win situation in social and economic benefits. Summary of the invention

[0006] The purpose of the present invention is to provide a solvent-based alkyd protective coating with high flash point (67-70° C.), high solid content, fast drying, good yellowing resistance, impact resistance, salt water resistance, excellent adhesion, and low VOC content, and a preparation method thereof.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A high flash point alkyd protective coating, the coating comprising the following ingredients:

[0009]

[0010] Furthermore, the coating is composed of the following ingredients:

[0011]

[0012] In the technical solution of the present invention, the high flash point alkyd resin is composed of the following components:

[0013]

[0014]

[0015] Furthermore, the high flash point alkyd resin is composed of the following components:

[0016]

[0017] In the preparation method of high flash point alkyd resin: the mixed fatty acid is soybean oil fatty acid, sunflower oil fatty acid and tung oil fatty acid in a mass ratio of 1-5:0.1-3:0.1-3;

[0018] Preferably, the mass ratio of soybean oil fatty acid: sunflower oil fatty acid: tung oil fatty acid is 1-2.5: 0.5-1.5: 0.2-1.0;

[0019] The mixed polyol is a mixture of glycerol, pentaerythritol and ethylene glycol, and the mass ratio of glycerol: pentaerythritol: ethylene glycol is 30-60:10-40:5-20; preferably, the mass ratio of glycerol: pentaerythritol: ethylene glycol is 40-55:10-25:5-15;

[0020] The mixed dibasic acid is a mixture of phthalic anhydride and isophthalic acid; wherein the mass ratio of phthalic anhydride to isophthalic acid is 1:0.1-1; preferably, the mass ratio of phthalic anhydride to isophthalic acid is 1:0.1-0.5;

[0021] The petroleum resin is ES-120S C9 petroleum resin produced by Qingdao Yisen New Materials Co., Ltd.

[0022] The high flash point solvent is obtained by mixing D60 mixed alkane solvent oil of Shandong Chuangli New Materials and P-1500 aromatic solvent oil of Pengchen New Materials Technology Co., Ltd. in a mass ratio of 1 to 2:1 to 1.5.

[0023] The high flash point alkyd resin of the present invention is prepared by the following steps:

[0024] S1: Under nitrogen protection, add fatty acid I, E51 epoxy resin and part of xylene into the reaction kettle, stir evenly, heat to 220-240°C, and stir for 2-4h;

[0025] S2: Cool down to 50-70°C, add fatty acid II and mixed polyols, stir evenly, add mixed dibasic acid, benzoic acid and remaining xylene in sequence, heat up to 180-220°C, dehydrate and esterify until the acid value of the material is ≤8mg KOH / g and the format tube viscosity is ≥18s;

[0026] S3: distill to remove xylene, then cool to 100-120°C, add petroleum resin, and stir until the petroleum resin is completely dissolved; cool, add high flash point solvent, stir evenly, and filter to obtain high flash point alkyd resin;

[0027] Wherein: the fatty acid I is a mixture of soybean oil fatty acid and sunflower oil fatty acid; the fatty acid II is tung oil fatty acid.

[0028] The raw materials of the high flash point alkyd protective coating are defined as follows:

[0029] The high flash point solvent is obtained by mixing D60 mixed alkane solvent oil of Shandong Chuangli New Materials and P-1500 aromatic solvent oil of Pengchen New Materials Technology Co., Ltd. in a mass ratio of 40-55:20-35.

[0030] The pigment is one or more of rutile titanium dioxide, phthalocyanine blue, phthalocyanine green, pigment red 170, pigment yellow 83, carbon black, and red iron oxide;

[0031] The filler is one or more of barium sulfate, calcium carbonate, talcum powder, and feldspar powder;

[0032] The bentonite is one or both of Zhejiang Fenghong BS-1C bentonite and BYK AF bentonite;

[0033] The dispersant is one or more of Shanghai Shenzhu Chemical SN-2041A, BASF Efka additive AFCONA S527, and Digo Dispers 630;

[0034] The drying agent is one or more of Shanghai Changfeng Chemical LC-804 drying agent, Shanghai Changfeng Chemical 828-1 cobalt-lead-calcium mixed drying agent, and Shanghai Shenzhu Chemical SN-9318 organic tin drying agent;

[0035] The anti-skinning agent is one or both of Shandong Laiwu 841 anti-skinning agent and butanone oxime anti-skinning agent.

[0036] The method for preparing the high flash point alkyd protective coating of the present invention comprises the following steps:

[0037] S1: Add 60-80% of high flash point alkyd resin, 30-50% of high flash point solvent and dispersant into the paint mixing kettle and stir evenly. Add bentonite, filler and pigment in turn and disperse at high speed until there is no powder or agglomeration. Transfer the slurry into a sand mill and grind it to a fineness of less than 30μm.

[0038] S2: Add the remaining high flash point alkyd resin to the above slurry, mix evenly, add drying agent and anti-skinning agent, stir evenly at high speed, add the remaining high flash point solvent to adjust the coating viscosity, filter and package to obtain the high flash point alkyd protective coating.

[0039] Beneficial effects of the present invention:

[0040] The technical solution disclosed in the present invention has the following beneficial effects:

[0041] (1) The closed cup flash point of the coating is ≥67°C, which does not belong to flammable liquids or explosives, and can be stored and transported as ordinary goods. This is because the technical solution of the present invention selects mixed alkane solvent oil with a boiling range of 205-245°C and aromatic solvent oil with a boiling range of 178-215°C as the dispersion medium of the coating, which ensures that the flash point meets the standard while also providing good resin solubility and drying properties.

[0042] (2) Compared with the same type of high-flash point coatings on the market, the technical solution disclosed in the present invention has faster surface drying and actual drying speeds, and the construction efficiency is comparable to that of traditional low-flash point alkyd coatings. The technical points for achieving quick drying characteristics of the present invention mainly include: a. A coating film-forming system composed of a high molecular weight alkyd resin and a high-solubility aromatic solvent oil; b. Drying oil modification of the resin; c. Epoxy modification of the resin; d. Petroleum resin modification; e. Use of high-boiling mixed alkane solvent oil; f. Composite drying agent solution; g. High-quality solid content coating formula.

[0043] (3) Excellent yellowing resistance and corrosion resistance. In terms of yellowing resistance, thanks to the selection of high-linoleic sunflower oil fatty acids, the epoxy modification process is separated from the drying oil modification process, which avoids the yellowing of the drying oil under high-temperature processes. In terms of corrosion resistance, it is mainly achieved through the following technologies: a. A special polyol (propylene glycol, pentaerythritol, ethylene glycol) combination scheme, which can not only reduce the gel risk in the resin link, but also give the alkyd coating excellent mechanical strength and solvent resistance; b. A combination of dibasic acids and epoxy resin modification, which can improve the hydrolysis resistance of the coating and give the coating better substrate adhesion and chemical resistance. c. A reasonable combination of surface and internal drying agents ensures that the coating is fully cured in quick-drying applications.

[0044] (4) Low VOC emissions (≤390g / L). This is mainly due to the high-quality solid content and low-viscosity coating formula. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with embodiments, but the protection scope of the present invention is not limited thereto:

[0046] The raw materials in high flash point alkyd protective coatings are as follows:

[0047] The petroleum resin is ES-120S C9 petroleum resin of Qingdao Eson New Materials Co., Ltd., with a softening point temperature of 115-125°C; the purchase source includes but is not limited to: https: / / www.esunresin.com / h-pd-106.html

[0048] The high flash point solvent is obtained by mixing D60 mixed alkane solvent oil (boiling range of 205-245° C.) of Shandong Chuangli New Materials (purchase website includes but is not limited to http: / / www.chuanglixincailiao.com / dom / ProSearch.php?s_m_str_id=D3wEBI&keyWord=D60&username=chuangli6321) and P-1500 aromatic solvent oil (boiling range of 178-215° C.) of Pengchen New Materials Technology Co., Ltd. (purchase website includes but is not limited to http: / / www.pengchenchem.com / products_detail / id / 1.html) in a mass ratio of 15-40:10-20.

[0049] The pigment is one or more of rutile titanium dioxide, phthalocyanine blue, phthalocyanine green, pigment red 170, pigment yellow 83, carbon black, and red iron oxide;

[0050] The filler is one or more of barium sulfate, calcium carbonate, talcum powder, and feldspar powder;

[0051] The bentonite is one or both of Zhejiang Fenghong BS-1C bentonite and BYK AF bentonite;

[0052] The dispersant is one or more of Shanghai Shenzhu Chemical SN 2041A, BASF Efka additive AFCONAS527, and Digo Dispers630;

[0053] The drying agent is one or more of Shanghai Changfeng Chemical LC-804 drying agent, Shanghai Changfeng Chemical 828-1 cobalt-lead-calcium mixed drying agent, and Shanghai Shenzhu Chemical SN-9318 organic tin drying agent;

[0054] The anti-skinning agent is one or both of Shandong Laiwu 841 anti-skinning agent and butanone oxime anti-skinning agent.

[0055] The steps for preparing the alkyd protective coatings of Examples 1 to 3 and Comparative Examples 1 to 3 are as follows:

[0056] (1) Preparation of high flash point alkyd resin:

[0057] Under nitrogen protection, weigh soybean oil fatty acid, sunflower oil fatty acid, E51 epoxy resin, and part of xylene according to the formula in Table 1 and add them to the reactor and stir evenly. Heat to 230℃ and stir for 3h. Cool to 60℃, add tung oil fatty acid, propylene glycol, pentaerythritol, and ethylene glycol, and stir evenly. Add phthalic anhydride, isophthalic acid, benzoic acid, and the remaining xylene in sequence, heat to 200℃, dehydrate and esterify until the acid value of the material is ≤8mg KOH / g and the format tube viscosity is ≥18s. Distill to remove xylene, then cool to 110℃. Add C9 petroleum resin and stir until the C9 petroleum resin is completely dissolved. Cool, add mixed alkane solvent oil and aromatic solvent oil and stir evenly. Filter to obtain a high flash point alkyd resin.

[0058] Table 1 Material addition amount of high flash point alkyd resin in Examples 1 to 3 and Comparative Examples 1 to 3 (g)

[0059]

[0060] (2) Preparation of high flash point alkyd protective coating (iron red):

[0061] According to the formula in Table 2, add part of the high flash point alkyd resin, part of the mixed alkane solvent oil (D60 mixed alkane solvent oil of Shandong Chuangli New Materials), aromatic solvent oil (P-1500 aromatic solvent oil of Pengchen New Materials Technology Co., Ltd.), and SN-2041A dispersant to the paint mixing kettle and stir evenly. Add AF bentonite, barium sulfate, calcium carbonate and red iron oxide in turn, and disperse at high speed until there is no powder or agglomeration. Transfer the slurry to a sand mill and grind it to a fineness of less than 30μm. Add the remaining high flash point alkyd resin to the above slurry and mix evenly. Add 828-1 cobalt-lead-calcium mixed drier, LC-804 drier, and 841 anti-skinning agent and stir evenly at high speed. Add the remaining mixed alkane solvent oil (boiling range of 205-245℃) and aromatic solvent oil (boiling range of 178-215℃) to adjust the viscosity of the paint. Filter and package to obtain a high flash point alkyd protective coating.

[0062] Table 2 Material addition amount (g) of high flash point alkyd protective coating (iron red) in Examples 4 to 6 and Comparative Examples 4 to 6

[0063]

[0064]

[0065] Comparative Example 4

[0066] Other conditions were the same as those in Example 4, except that the high flash point alkyd resin prepared in Comparative Example 1 was used.

[0067] Comparative Example 5

[0068] Other conditions were the same as those in Example 4, except that the high flash point alkyd resin prepared in Comparative Example 2 was used.

[0069] Comparative Example 6

[0070] Other conditions were the same as those in Example 4, except that the high flash point alkyd resin prepared in Comparative Example 3 was used.

[0071] (3) Coating performance test:

[0072] Samples were taken to test the appearance, fineness, outflow time, flash point (closed cup), and storage stability of the coating. According to the requirements of GB / T25251-2010 "Alkyd Resin Coatings" standard, air spraying was used to coat the panels. After curing, mechanical properties, adhesion, anti-corrosion properties, resistance to artificial weathering, and other performance tests were performed. The test results are listed as follows (Table 3):

[0073] Table 3 Main technical indicators of high flash point alkyd protective coating (iron red) in Examples 4 to 6 and Comparative Examples 4 to 6

[0074]

[0075]

[0076] The test results show that the alkyd protective coating prepared by Examples 4 to 6 has a high flash point (67 to 70°C) through a specific fatty acid / polyol / diacid combination, epoxy resin modification, high flash point mixed solvent oil combination and drier combination, and can be stored and transported as ordinary goods, which not only saves the cost of the coating circulation link, but also improves the safety of the product. In addition, the technical solution also has many advantages such as fast drying (surface drying 1h, actual drying 16h), impact resistance (50cm), salt water resistance (168h without abnormality), excellent adhesion (cross-cut test level 0, pull-off adhesion 4.7 to 4.9MPa), gloss (86 to 89, 60°), high solid content (≥75%), low VOC content (≤390g / L), good yellowing resistance (resistance to artificial weathering 200h, discoloration level 1, loss of gloss level 2), etc.

[0077] Since the type and proportion of materials are closely related to coating performance, any change in material type or adjustment of material dosage may result in a reduction in coating quality.

[0078] For example, in Comparative Example 4, the fatty acid I in Comparative Example 4 only contains soybean oil fatty acid, but no sunflower oil fatty acid, and the rest of the materials are the same as those in Example 4, but the results are quite different. The test results show that after the material change, the coating of Comparative Example 4 dries faster (0.7h for surface drying and 14h for actual drying), but its mechanical properties (cross-cut test level 3, bending test 3mm, impact resistance 20cm), pull-out adhesion (2.4MPa), salt water resistance (48h blistering, rusting), and artificial weathering resistance (200h, discoloration level 3, gloss loss level 3) are significantly reduced.

[0079] Comparative Example 5 Compared with Example 5, the solvent in Comparative Example 5 is only mixed alkane solvent oil, and the other materials are the same as Example 4. However, the results show that the choice of solvent does not only affect the flash point (61°C) and drying (surface drying 0.9h, actual drying 15.5h), but also has a certain influence on its mechanical properties (cross-cut test level 2, bending test 2mm), pull-out adhesion (4.2MPa), VOC content (420g / L), and gloss (79, 60°). It may be that the different solubility of a single solvent on the resin leads to the changes in various properties.

[0080] Comparative Example 6 Compared with Example 6, the polyol in Comparative Example 6 is only glycerol, and the other materials are the same as Example 6. However, the results are also very different. The test results show that the drying property (surface drying 1.2h, actual drying 17h), mechanical properties (cross-cut test level 2, bending test 2mm, impact resistance 30cm), pendulum hardness (2.1, 7d), pull-out adhesion (2.9MPa), salt water resistance (48h blistering), artificial weathering resistance (200h, discoloration level 2, gloss loss level 3) are all significantly reduced.

[0081] In summary, it is explained that the selection of the types and amounts of materials such as fatty acids, polyols, solvents, etc. is very important for the preparation of alkyd resins. The present invention has also obtained better results after unremitting efforts and a large number of experimental verifications.

[0082] Finally, it should be noted that the above are only some embodiments of the present invention, which are the research results obtained by the laboratory after complex theoretical reasoning and a large number of experiments, and the protection scope of the present invention is not limited to this. Although the above embodiments have described the present invention in detail, for those skilled in the art, they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high flash point alkyd protective coating, characterized in that The paint consists of the following ingredients:

2. The high flash point alkyd protective coating according to claim 1, characterized in that The paint consists of the following ingredients:

3. The high flash point alkyd protective coating according to claim 1 or 2, characterized in that The high flash point alkyd resin is composed of the following components:

4. The high flash point alkyd protective coating according to claim 3, characterized in that The high flash point alkyd resin is composed of the following components:

5. The high flash point alkyd protective coating according to claim 3 or 4, characterized in that: The mixed fatty acid is soybean oil fatty acid, sunflower oil fatty acid and tung oil fatty acid in a mass ratio of 1-5:0.1-3:0.1-3; Preferably, the mass ratio of soybean oil fatty acid: sunflower oil fatty acid: tung oil fatty acid is 1-2.5: 0.5-1.5: 0.2-1.0; The mixed polyol is a mixture of glycerol, pentaerythritol and ethylene glycol, and the mass ratio of glycerol: pentaerythritol: ethylene glycol is 30-60:10-40:5-20; preferably, the mass ratio of glycerol: pentaerythritol: ethylene glycol is 40-55:10-25:5-15; The mixed dibasic acid is a mixture of phthalic anhydride and isophthalic acid; wherein the mass ratio of phthalic anhydride to isophthalic acid is 1:0.1-1; preferably, the mass ratio of phthalic anhydride to isophthalic acid is 1:0.1-0.5; The petroleum resin is ES-120S C9 petroleum resin produced by Qingdao Yisen New Materials Co., Ltd. The high flash point solvent is obtained by mixing D60 mixed alkane solvent oil of Shandong Chuangli New Materials and P-1500 aromatic solvent oil of Pengchen New Materials Technology Co., Ltd. in a mass ratio of 1 to 2:1 to 1.

5.

6. The high flash point alkyd protective coating according to claim 3 or 4, characterized in that The high flash point alkyd resin is prepared by the following steps: S1: Under nitrogen protection, add fatty acid I, E51 epoxy resin and part of xylene into the reaction kettle, stir evenly, heat to 220-240°C, and stir for 2-4h; S2: Cool down to 50-70°C, add fatty acid II and mixed polyols, stir evenly, add mixed dibasic acid, benzoic acid and remaining xylene in sequence, heat up to 180-220°C, dehydrate and esterify until the acid value of the material is ≤8mg KOH / g and the format tube viscosity is ≥18s; S3: distill to remove xylene, then cool to 100-120°C, add petroleum resin, and stir until the petroleum resin is completely dissolved; cool, add high flash point solvent, stir evenly, and filter to obtain high flash point alkyd resin; Wherein: the fatty acid I is a mixture of soybean oil fatty acid and sunflower oil fatty acid; the fatty acid II is tung oil fatty acid.

7. The high flash point alkyd protective coating according to claim 1, characterized in that: The high flash point solvent is obtained by mixing D60 mixed alkane solvent oil of Shandong Chuangli New Materials and P-1500 aromatic solvent oil of Pengchen New Materials Technology Co., Ltd. in a mass ratio of 40-55:20-35. The pigment is one or more of rutile titanium dioxide, phthalocyanine blue, phthalocyanine green, pigment red 170, pigment yellow 83, carbon black, and red iron oxide; The filler is one or more of barium sulfate, calcium carbonate, talcum powder, and feldspar powder; The bentonite is one or both of Zhejiang Fenghong BS-1C bentonite and BYK AF bentonite; The dispersant is one or more of Shanghai Shenzhu Chemical SN-2041A, BASF Efka additive AFCONAS527, and Digo Dispers630; The drying agent is one or more of Shanghai Changfeng Chemical LC-804 drying agent, Shanghai Changfeng Chemical 828-1 cobalt-lead-calcium mixed drying agent, and Shanghai Shenzhu Chemical SN-9318 organic tin drying agent; The anti-skinning agent is one or both of Shandong Laiwu 841 anti-skinning agent and butanone oxime anti-skinning agent.

8. A method for preparing the high flash point alkyd protective coating according to claim 1, characterized in that: The method comprises the following steps: S1: Add 60-80% of high flash point alkyd resin, 30-50% of high flash point solvent and dispersant into the paint mixing kettle and stir evenly. Add bentonite, filler and pigment in turn and disperse at high speed until there is no powder or agglomeration. Transfer the slurry into a sand mill and grind it to a fineness of less than 30μm. S2: Add the remaining high flash point alkyd resin to the above slurry, mix evenly, add drying agent and anti-skinning agent, stir evenly at high speed, add the remaining high flash point solvent to adjust the coating viscosity, filter and package to obtain the high flash point alkyd protective coating.

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