Quick-drying environment-friendly repairing varnish composition as well as preparation method and application thereof

Abstract

The invention provides a quick-drying environment-friendly repairing varnish composition as well as a preparation method and application thereof. The quick-drying environment-friendly repairing varnish composition comprises a component A and a component B, the component A is prepared from the following components in parts by weight: 60 to 80 parts of acrylic resin, 5 to 25 parts of polyester resin, 0.02 to 0.5 part of a drier, 0.2 to 0.8 part of a flatting agent, 1 to 2 parts of an anti-aging auxiliary agent, 0.5 to 1.5 parts of an anti-sagging auxiliary agent and 10 to 20 parts of a component A solvent; the component B is prepared from 80 to 100 parts of isocyanate, 0 to 20 parts of a component B solvent and 0.01 to 0.5 part of a water removal agent; wherein the anti-sagging auxiliary agent is selected from fumed silica subjected to hydrophobic modification; the average particle size of primary particles of the fumed silica is 10-20 nm, and the BET surface area is 70-200 m < 2 > / g. The quick-drying environment-friendly repair varnish composition has the advantages of quick drying and low VOC (volatile organic compound), has excellent paint film performance and construction performance, can be used as automobile paint to be applied to automobile factory coating workshops and automobile quick repair factories, and provides more choices for customers.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and specifically includes a fast-drying environmentally friendly repair varnish composition, a preparation method thereof, and an application thereof. Background Art

[0002] During the process of automobile repair, it is required that the repair varnish can be cured at normal temperature or low temperature to ensure the integrity of other components. Traditional repair varnishes are prepared using high molecular weight resins, which can ensure relatively fast drying of the coating film and can be cured under low temperature conditions. However, a large amount of diluent needs to be added to achieve good workability, which results in VOC emissions exceeding the national environmental protection requirements. Moreover, the coating film prepared in this way has poor fullness and gloss, and it is also difficult to meet consumers' requirements for the appearance of automobiles. The latest national standard requires that the VOC of two-component varnishes for automobiles be ≤ 420 g / L. In order to meet the VOC requirements, low molecular weight and high solid content resins are usually used to prepare repair varnishes with good workability. However, this is prone to sagging and slow drying speed, and the polishing and assembly processes cannot be carried out in a timely manner, reducing the efficiency of automobile repair. Therefore, it is urgently needed in the market to prepare a fast-drying, low-VOC automobile repair varnish with good workability. Summary of the Invention

[0003] In view of the above problems existing in the prior art, the first object of the present invention is to provide a fast-drying environmentally friendly repair varnish composition.

[0004] The second object of the present invention is to provide a preparation method for preparing the above-mentioned fast-drying environmentally friendly repair varnish composition.

[0005] The third object of the present invention is to provide an application of using the above-mentioned fast-drying environmentally friendly repair varnish composition as an automobile paint.

[0006] To achieve the above first object, the technical solutions adopted by the present invention include:

[0007] The present invention discloses a fast-drying environmentally friendly repair varnish composition, which comprises component A and component B;

[0008] By weight, component A comprises 60-80 parts of acrylic resin, 5-25 parts of polyester resin, 0.02-0.5 part of drier, 0.2-0.8 part of leveling agent, 1-2 parts of anti-aging aid, 0.5-1.5 parts of anti-sagging aid, and 10-20 parts of solvent for component A;

[0009] Component B comprises 80-100 parts of isocyanate, 0-20 parts of solvent for component B, and 0.01-0.5 part of water scavenger;

[0010] Among them, the anti-sagging agent is selected from hydrophobically modified fumed silica; the average primary particle size of the fumed silica is 10-20 nm, and the BET surface area is 70-200 m 2 / g.

[0011] Furthermore, the anti-sagging agent is selected from at least one of AEROSIL R972 fumed silica, AEROSIL R974 fumed silica, and AEROSIL R202 fumed silica.

[0012] Furthermore, the solid content of the acrylic resin is 70-80%, the weight-average molecular weight is 3000-12000, the viscosity is (G-H, 25°C) X-Z1, the hydroxyl content is 3-7%, and the acid value is 5-20 mgKOH / g;

[0013] The polyester resin is a polyester resin having a highly branched structure and / or a hyperbranched structure; the solid content of the polyester resin is 60-80%, the hydroxyl value is 200-350 mgKOH / g, and the viscosity is 150-300 mPa.s / 60°C.

[0014] Furthermore, the acrylic resin is selected from at least one of ACS-1284 acrylic resin, Uracron CY 430E-70 acrylic resin, ETERAC 7307A-XS-70 acrylic resin, AZS-797 acrylic resin, and Nuplex Setalux 1762VV-70 acrylic resin;

[0015] The polyester resin is selected from at least one of PRS-1014RESIN polyester resin, CAPA3050 polyester resin, and DURANOLTMT5650E polyester resin.

[0016] Furthermore, the drier is selected from at least one of stannous octoate, dibutyltin dilaurate, and WCAT-WP01;

[0017] The leveling agent is selected from at least one of BYK-390 additive, BYK-325N additive, BYK-326 additive, BYK-397 additive, and EFKA3600 leveling agent;

[0018] The anti-aging agent is selected from at least one of Tinuvin 123 light stabilizer, Omnistab 123 light stabilizer, RIASORBUV-292 light stabilizer, AU 1130 ultraviolet absorber, and Tinuvin 384-2 ultraviolet absorber.

[0019] Furthermore, the isocyanate is a weather-resistant isocyanate; preferably HDI trimer and / or IPDI trimer;

[0020] The water remover is selected from ADDITIVE TI monofunctional isocyanate and / or ADDITIVE OF water remover.

[0021] Furthermore, the solvent of component A is selected from at least one of solvent naphtha S-100, solvent naphtha S-150, butyl acetate, methyl isobutyl ketone, xylene, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, and EEP;

[0022] The solvent of component B is selected from at least one of butyl acetate, solvent naphtha S-100, and methyl isobutyl ketone, and its moisture content is ≤ 300 ppm.

[0023] To achieve the above second object, the technical solution adopted by the present invention includes:

[0024] The present invention discloses a preparation method of the environmentally friendly repair varnish composition as described above, including the following steps:

[0025] In the first step, 0.5 - 1.5 parts of the anti-sagging aid is dispersed into part of the acrylic resin and part of the solvent of component A. After uniform dispersion, the obtained premix is subjected to sanding treatment until the particle fineness is ≤ 5 μm to obtain the anti-sagging sanding slurry;

[0026] In the second step, under stirring, the remaining acrylic resin, 5 - 25 parts of the polyester resin, 0.02 - 0.5 part of the dryer, 0.2 - 0.8 part of the leveling agent, 1 - 2 parts of the anti-aging aid, and the anti-sagging sanding slurry prepared in the first step are successively added to the remaining solvent of component A, and after stirring evenly, component A is obtained;

[0027] In the third step, under stirring, 80 - 100 parts of isocyanate and 0.01 - 0.5 part of the water remover are successively added to 0 - 20 parts of the solvent of component B, and after stirring evenly, component B is obtained;

[0028] In the fourth step, component A and component B are mixed according to a volume ratio of 3:1, and then adjusted to the construction viscosity with a diluent to obtain the fast-drying environmentally friendly repair varnish composition.

[0029] Furthermore, in the anti-sagging sanding slurry, the anti-sagging aid, the acrylic resin, and the solvent of component A total 100 wt%, wherein the anti-sagging aid accounts for 10 - 15 wt%, the acrylic resin accounts for 50 - 70 wt%, and the solvent of component A accounts for 20 - 35 wt%.

[0030] To achieve the above third object, the technical solution adopted by the present invention includes:

[0031] The present invention discloses the application of the environmentally friendly repair varnish composition as described above as an automotive paint.

[0032] Advantages of the present invention:

[0033] The quick-drying and environmentally friendly repair varnish composition provided by the present invention has the advantages of quick drying and low VOC. When reaching the construction viscosity, VOC < 420 g / L, which meets the latest national standard VOC emission requirements. At the same time, it has excellent film properties (impact resistance, adhesion, water resistance, hardness, weather resistance, etc.) and construction properties (anti-sagging property, gloss, polishable time, etc.), with excellent comprehensive performance, and can be used as automotive paint in automotive factory painting workshops and automotive quick repair factories, providing more choices for customers. Detailed implementation manners

[0034] To illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments. It should be clear that the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0035] In the case of clarifying and explaining the purpose of the present invention through the following embodiments, the components of the composition are explained with parts by weight as the general standard. Without special instructions, for the sake of simplicity, the "parts" described in the embodiments of the present invention have the same meaning as parts by weight.

[0036] In order to provide better services when customers repair cars and meet the customers' selection needs for various types of varnishes, based on the combination method of a type of acrylic resin and polyester resin disclosed in the prior art, the present invention develops a quick-drying and low-VOC automotive repair varnish composition with good workability. A hydrophobically modified fumed silica is introduced as an anti-sagging aid in the automotive repair varnish composition, so that it can add a smaller amount of diluent to reach the construction viscosity, thereby obtaining a lower VOC and meeting the VOC requirements of the latest national standard.

[0037] The first aspect of the present invention provides a quick-drying and environmentally friendly repair varnish composition, comprising component A and component B; component A is the varnish component, and component B is the curing agent component;

[0038] By weight, component A comprises 60 - 80 parts of acrylic resin, 5 - 25 parts of polyester resin, 0.02 - 0.5 part of drier, 0.2 - 0.8 part of leveling agent, 1 - 2 parts of anti-aging aid, 0.5 - 1.5 parts of anti-sagging aid, and 10 - 20 parts of component A solvent;

[0039] Component B comprises 80 - 100 parts of isocyanate, 0 - 20 parts of component B solvent, and 0.01 - 0.5 part of water remover;

[0040] Among them, the anti-sagging aid is selected from hydrophobically modified fumed silica; the average primary particle size of the fumed silica is 10 - 20 nm, and the BET surface area is 70 - 200 m 2 / g.

[0041] Exemplarily, the anti-sagging aid is selected from at least one of Evonik AEROSIL R972 fumed silica (average primary particle size 16 nm, BET surface area 90 - 130 m 2 / g), Evonik AEROSIL R974 fumed silica (average primary particle size 12 nm, BET surface area 150 - 190 m 2 / g), and Evonik AEROSIL R202 fumed silica (average primary particle size 14 nm, BET surface area 80 - 120 m 2 / g). The fumed silica of these grades are hydrophobically modified fumed silica products, having low hygroscopicity, good dispersibility, and having little influence on the high-shear viscosity of the system, and thus not affecting the workability.

[0042] The acrylic resin provided by the present invention has a solid content of 70 - 80%, a weight-average molecular weight of 3000 - 12000, a viscosity of (G-H, 25 °C) X-Z1, a hydroxyl content of 3 - 7%, and an acid value of 5 - 20 mgKOH / g.

[0043] Exemplarily, the acrylic resin is selected from at least one of ACS-1284 acrylic resin, Uracron CY 430E-70 acrylic resin, ETERAC 7307A-XS-70 acrylic resin, AZS-797 acrylic resin, and Nuplex Setalux 1762VV-70 acrylic resin; preferably Uracron CY 430E-70 acrylic resin, AZS-797 acrylic resin, and ETERAC 7307A-XS-70 acrylic resin.

[0044] The polyester resin provided by the present invention has a solid content of 60 - 80%, a hydroxyl value of 200 - 350 mgKOH / g, and a viscosity (60 °C) of 150 - 300 mPa·s.

[0045] Exemplarily, the polyester resin is selected from at least one of PRS-1014RESIN polyester resin, CAPA 3050 polyester resin, and DURANOLTM T5650E polyester resin; preferably CAPA 3050 polyester resin and PRS-1014RESIN polyester resin.

[0046] In a specific embodiment, the combination of Uracron CY 430E-70 acrylic resin and CAPA 3050 polyester resin, the combination of AZS-797 acrylic resin and CAPA 3050 polyester resin, and the combination of ETERAC 7307A-XS-70 acrylic resin and PRS-1014 RESIN polyester resin have better performance.

[0047] Exemplarily, the drier is selected from at least one of stannous octoate (T9), dibutyltin dilaurate (T12), and WCAT-WP01.

[0048] Exemplarily, the leveling agent is selected from at least one of BYK-390 additive, BYK-325N additive, BYK-326 additive, BYK-397 additive, and EFKA3600 leveling agent.

[0049] Exemplarily, the anti-aging additive is selected from at least one of Tinuvin 123 light stabilizer, Omnistab 123 light stabilizer, RIASORB UV-292 light stabilizer, AU 1130 ultraviolet absorber, and Tinuvin 384-2 ultraviolet absorber.

[0050] Exemplarily, the solvent for component A is selected from at least one of S-100 solvent naphtha, S-150 solvent naphtha, butyl acetate, methyl isobutyl ketone, xylene, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, and EEP.

[0051] Exemplarily, the solvent for component B is selected from at least one of butyl acetate, S-100 solvent naphtha, and methyl isobutyl ketone, and its moisture content ≤ 300 ppm.

[0052] Furthermore, the isocyanate is a weather-resistant isocyanate; preferably HDI trimer and / or IPDI trimer.

[0053] Exemplarily, the isocyanate is selected from at least one of NPU Coronate C-HXT isocyanate, Bayer Desmodur N3300 isocyanate, Bayer Desmodur N3600 isocyanate, Bayer Desmodur N3900 isocyanate, Bayer Desmodur Z4470 BA isocyanate, and Asahi Kasei Duranate TPA100 isocyanate.

[0054] Exemplarily, the water scavenger is selected from ADDITIVE TI monofunctional isocyanate and / or ADDITIVE OF water scavenger.

[0055] Furthermore, the environmentally friendly repair varnish composition further includes a diluent, and the addition amount of the diluent is adjusted to the construction viscosity. The dosage of the diluent will directly affect the VOC of the coating film, with the aim of achieving the construction viscosity requirement of the varnish composition by introducing less diluent.

[0056] In the present invention, the addition method of the anti-sagging aid also needs to be controlled, that is, the anti-sagging aid is pre-dispersed and sanded with a part of the acrylic resin and a part of the solvent of Component A to obtain an anti-sagging sanding slurry, and then the anti-sagging sanding slurry is mixed with other Component A materials to obtain a varnish component. The specific steps are as follows:

[0057] Disperse 0.5 - 1.5 parts of the anti-sagging aid into a part of the acrylic resin and a part of the solvent of Component A. After uniform dispersion, sand the obtained premix to a particle fineness ≤ 5 μm to obtain an anti-sagging sanding slurry;

[0058] Among them, in the anti-sagging sanding slurry, the anti-sagging aid, acrylic resin, and solvent of Component A total 100 wt%, among which the anti-sagging aid accounts for 10 - 15 wt%, the acrylic resin accounts for 50 - 70 wt%, and the solvent of Component A accounts for 20 - 35 wt%; preferably, the anti-sagging aid accounts for 10 wt%, the acrylic resin accounts for 60 wt%, and the solvent of Component A accounts for 30 wt%.

[0059] The second aspect of the present invention provides a preparation method of the environmentally friendly repair varnish composition as described above, including the following steps:

[0060] Under stirring, sequentially add the remaining acrylic resin, 5 - 25 parts of polyester resin, 0.02 - 0.5 parts of drier, 0.2 - 0.8 parts of leveling agent, 1 - 2 parts of anti-aging aid, and the aforementioned prepared anti-sagging sanding slurry into the remaining solvent of Component A, and stir evenly to obtain Component A;

[0061] Under stirring, sequentially add 80 - 100 parts of isocyanate and 0.01 - 0.5 parts of water remover into 0 - 20 parts of solvent of Component B, and stir evenly to obtain Component B;

[0062] Mix Component A and Component B according to a volume ratio of 3:1, and then use a diluent to adjust to the construction viscosity to obtain the fast-drying environmentally friendly repair varnish composition.

[0063] Furthermore, the construction viscosity is 18 - 20 s / coat 4 cup (25 °C).

[0064] Exemplarily, the diluent used to adjust the construction viscosity is Diluent #20 of Nippon Paint.

[0065] The following will be further illustrated by examples.

[0066] Example 1

[0067] This example provides an environmentally friendly repair varnish composition, and its specific formulation is shown in Table 1.1 and Table 1.2.

[0068] Table 1.1

[0069]

[0070] Table 1.2

[0071] Serial Number Type Component B Curing Agent Example 1 / part 1 Solvent Butyl Acetate 6 2 Solvent Methyl Isobutyl Ketone 2 3 Solvent S-100 Solvent Oil 1.7 4 Auxiliary Agent ADDITIVE TI Monofunctional Isocyanate 0.3 5 Resin Desmodur N3300 Isocyanate 90

[0072] The preparation process of the environmentally friendly repair varnish composition is as follows:

[0073] First step: Mix materials 10 - 12 in the A-component varnish evenly, and then sand grind until the fineness is ≤5μm to make an anti-sagging sanding slurry.

[0074] Second step: Add A-component varnish materials 1 - 9, the anti-sagging sanding slurry from the first step, and materials 13 - 14 in sequence under stirring, and stir evenly to obtain the A-component varnish.

[0075] Third step: Add B-component curing agent materials 1 - 5 in sequence under stirring, and stir evenly to obtain the B-component curing agent.

[0076] Fourth step: Mix the A-component varnish and the B-component curing agent evenly according to a volume ratio of 3:1, and use a diluent to adjust the viscosity to the construction viscosity, that is, 18 - 20 s / coat - 4 cup (25°C), to obtain a fast-drying environmentally friendly repair varnish composition.

[0077] Comparative Examples 1 - 3

[0078] The formulations of the varnish compositions in Comparative Examples 1 - 3 are shown in Table 2.1 and Table 2.2. Among them, the difference between Comparative Example 1 and Example 1 is only that a high molecular weight ACS-1276 acrylic resin is used to replace the Uracron CY 430E-70 acrylic resin. The difference between Comparative Example 2 and Example 1 is only that the dosage of AEROSIL R974 fumed silica is reduced to 0.3 parts. The difference between Comparative Example 3 and Example 1 is only that the dosage of AEROSIL R974 fumed silica is increased to 1.7 parts.

[0079] Table 2.1

[0080]

[0081] Table 2.2

[0082] Serial Number Type Component B Curing Agent Comparative Example 1-3 / part 1 Solvent Butyl Acetate 6 2 Solvent Methyl Isobutyl Ketone 2 3 Solvent S-100 Solvent Oil 1.7 4 Auxiliary Agent ADDITIVE TI Monofunctional Isocyanate 0.3 5 Resin Desmodur N3300 Isocyanate 90

[0083] The preparation process of the varnish composition is as follows:

[0084] Step 1: Mix materials 10 - 12 in the A-component varnish evenly, and then perform sanding until the fineness is ≤ 5 μm to prepare an anti-sagging sanding slurry.

[0085] Step 2: Add A-component varnish materials 1 - 9, the anti-sagging sanding slurry from Step 1, and materials 13 - 14 in sequence under stirring, and stir evenly to obtain the A-component varnish.

[0086] Step 3: Add B-component curing agent materials 1 - 5 in sequence under stirring, and stir evenly to obtain the B-component curing agent.

[0087] Step 4: Mix the A-component varnish and the B-component curing agent evenly according to a volume ratio of 3:1, and use a diluent to adjust the viscosity to the construction viscosity, i.e., 18 - 20 s / coat - 4 cup (25 °C) to obtain a repair varnish composition.

[0088] Compare the performance of the varnish compositions obtained in Example 1 and Comparative Examples 1 - 3. The obtained results are shown in Table 3. Among them, for the VOC test, the directly prepared varnish composition is used and tested according to the method specified in GB 24409. For other properties, a SATA HVLP spray gun is used to spray onto the sample board according to the film thickness requirement, and the performance is tested after drying.

[0089] The evaluation methods are as follows:

[0090] 1. VOC: Test VOC according to GB 24409.

[0091] 2. Anti-sagging property: Test the anti-sagging property of the coating according to GB / T 9264 - 2012.

[0092] 3. Impact resistance: Test the impact resistance of the paint film according to GB / T 1732 - 2020.

[0093] 4. Coating adhesion: According to the GB / T 9286 - 2021 standard, the cross-cut method is used for the cross-cut adhesion test.

[0094] 5. Water resistance: According to the GB / T 5209 - 85 standard, after the paint films formed in Example 1 and Comparative Examples 1 - 3 are soaked at 40 °C for 240 hours, observe the appearance of the paint films after recovery for 10 - 20 min, 1 - 2 h, and 24 - 26 h respectively, and classify the grades according to the size and density of the bubbles on the paint film surface.

[0095] 6. Hardness: Test the pencil hardness according to GB / T 6739 - 2006.

[0096] 7. 60° gloss: Conduct according to the provisions of GB / T 9754 - 2007.

[0097] 8. Polishing time: 60°C * 30 min. After cooling for half an hour, perform polishing and confirm whether there is sandpaper sticking, difficult polishing, or severe polishing marks.

[0098] 7. Accelerated weather resistance: Conduct according to Cycle A specified in GB / T 1865-2009. In case of film defects such as chalking, blistering, peeling, cracking, color change, and loss of gloss, describe them according to GB / T 1766-2008.

[0099] Table 3

[0100]

[0101] As can be seen from the above table, the clear coat composition prepared in Example 1 can meet the VOC emission requirements and customer performance requirements. When using high molecular weight acrylate ACS-1276 acrylic resin as the main resin to prepare automotive refinish clear coat in Comparative Example 1, due to its high viscosity, more diluent needs to be added to reach the construction viscosity, ultimately resulting in excessive VOC and failure to meet customer requirements in sag resistance, pencil hardness, polishing time, and accelerated weather resistance. The reason is that the solid content of ACS-1276 acrylic resin is relatively low (solid content 60%), leading to an unsuitable ratio of acrylic resin to isocyanate. In Comparative Example 2, due to the low addition of anti-sag aid, its sag resistance cannot meet the customer's construction requirements. In Comparative Example 3, due to the excessive addition of anti-sag aid, the coating viscosity is too high, and even with the same amount of diluent as in Example 1, the construction viscosity cannot be reached, and more diluent needs to be added to reach the construction viscosity, ultimately resulting in excessive VOC. At the same time, the excessive addition of anti-sag aid will cause the film gloss to be too low, which also does not meet customer requirements.

[0102] Example 2

[0103] This example provides an environmentally friendly refinish clear coat composition, and its specific formulation is shown in Table 4.1 and Table 4.2.

[0104] Table 4.1

[0105]

[0106] Table 4.2

[0107] Serial Number Type Component B Curing Agent Example 2 / part 1 Solvent Butyl Acetate 6.3 2 Solvent Methyl Isobutyl Ketone 1.7 3 Solvent ADDITIVE TI Monofunctional Isocyanate 0.3 4 Auxiliary Agent Desmodur N3900 Isocyanate 56 5 Resin Desmodur Z4470 BA Isocyanate 35.7

[0108] The preparation process of the environmentally friendly refinish clear coat composition is as follows:

[0109] First step: Mix materials 10 - 12 in Component A clear coat evenly, and then perform sanding until the fineness ≤ 5 μm to prepare an anti-sag sanding slurry;

[0110] Step 2: While stirring, sequentially add A-component varnish materials 1-9, the anti-sagging abrasive slurry from the first step, and materials 13-14, and stir evenly to obtain the A-component varnish;

[0111] Step 3: While stirring, sequentially add B-component curing agent materials 1-5, and stir evenly to obtain the B-component curing agent;

[0112] Step 4: Mix the A-component varnish and the B-component curing agent evenly according to a volume ratio of 3:1, and use a diluent to adjust the viscosity to the construction viscosity, i.e., 18-20 s / coat-4 cup (25 °C), to obtain a fast-drying environmental protection repair varnish composition.

[0113] Comparative Examples 4-6

[0114] The formulation of the varnish compositions of Comparative Examples 4-6 is shown in Tables 5.1 and 5.2. Among them, the difference between Comparative Example 4 and Example 2 in the formulation is only that DISPARLON 6900 is used as an anti-sagging aid to replace AEROSIL R972 fumed silica. The difference between Comparative Example 5 and Example 2 in the formulation is only that BYK-410 is used as an anti-sagging aid to replace AEROSIL R972 fumed silica. The difference between Comparative Example 6 and Example 2 is only that AEROSIL R812S fumed silica (average primary particle size 7 nm, BET surface area 230-290 m 2 / g) is used to replace AEROSIL R972 fumed silica.

[0115] Table 5.1

[0116]

[0117] Table 5.2

[0118] Serial Number Type Component B Curing Agent Comparative Example 4-6 / part 1 Solvent Butyl Acetate 6.3 2 Solvent Methyl Isobutyl Ketone 1.7 3 Solvent ADDITIVE TI Monofunctional Isocyanate 0.3 4 Auxiliary Agent Desmodur N3900 Isocyanate 56 5 Resin Desmodur Z4470 BA Isocyanate 35.7

[0119] The preparation process of the varnish composition described in Comparative Example 4 is as follows:

[0120] Step 1: Mix materials 10-11 in the A-component varnish evenly, then add material 12 at a speed of 1000-1500 rpm. After the addition is complete, increase the speed to 2000-3000 rpm and disperse at high speed for 15-30 min to prepare an anti-sagging premix;

[0121] Step 2: While stirring, sequentially add A-component varnish materials 1-9, the anti-sagging premix from the first step, and materials 13-14, and stir evenly to obtain the A-component varnish;

[0122] Step 3: While stirring, sequentially add B-component curing agent materials 1-5, and stir evenly to obtain the B-component curing agent;

[0123] Step 4: Mix Component A varnish and Component B curing agent evenly at a volume ratio of 3:1, and use a diluent to adjust the viscosity to the construction viscosity, i.e., 18 - 20 s / coat - 4 cup (25 °C), to obtain a repair varnish composition.

[0124] The preparation process of the varnish composition described in Comparative Example 5 is as follows:

[0125] Step 1: Sequentially add Component A varnish materials 1 - 14 under stirring, and stir evenly to obtain Component A varnish;

[0126] Step 2: Sequentially add Component B curing agent materials 1 - 5 under stirring, and stir evenly to obtain Component B curing agent;

[0127] Step 3: Mix Component A varnish and Component B curing agent evenly at a volume ratio of 3:1, and adjust the viscosity to the construction viscosity, i.e., 18 - 20 s / coat - 4 cup (25 °C), to obtain a repair varnish composition.

[0128] The preparation process of the varnish composition described in Comparative Example 6 is as follows:

[0129] Step 1: Mix materials 10 - 12 in Component A varnish evenly, and then perform sanding until the fineness ≤ 5 μm to prepare an anti - sagging premix;

[0130] Step 2: Sequentially add Component A varnish materials 1 - 9, the anti - sagging premix from the first step, and materials 13 - 14 under stirring, and stir evenly to obtain Component A varnish;

[0131] Step 3: Sequentially add Component B curing agent materials 1 - 5 under stirring, and stir evenly to obtain Component B curing agent;

[0132] Step 4: Mix Component A varnish and Component B curing agent evenly at a volume ratio of 3:1, and adjust the viscosity to the construction viscosity, i.e., 18 - 20 s / coat - 4 cup (25 °C), to obtain a repair varnish composition.

[0133] Compare the performance of the varnish compositions obtained in Example 2 and Comparative Examples 4 - 6. The evaluation method is the same as that in Example 1. The obtained results are shown in Table 6.

[0134] Table 6

[0135]

[0136] As can be seen from the above table, the varnish composition prepared in Example 2 can meet the VOC emission requirements and customer performance requirements. In Comparative Example 4, DISPARLON 6900 was used as an anti-sagging aid to prepare an automotive refinish varnish. The coating viscosity was too high. Even when adding the same amount of diluent as in Example 2, the application viscosity could not be achieved, and more diluent needed to be added to reach the application viscosity. Eventually, its VOC exceeded the standard, and its anti-sagging property was slightly lower than the customer's application requirements. In Comparative Example 5, BYK-410 was used as an anti-sagging aid to prepare an automotive refinish varnish. The coating viscosity was too high. Even when adding the same amount of diluent as in Example 2, the application viscosity could not be achieved, and more diluent needed to be added to reach the application viscosity. Eventually, its VOC exceeded the standard. In Comparative Example 6, AEROSIL R812S fumed silica was used as an anti-sagging aid to prepare an automotive refinish varnish. Due to the smaller average particle size and larger BET surface area of AEROSIL R812S fumed silica, the coating viscosity was too high, and more diluent needed to be added to reach the application viscosity. Eventually, its VOC exceeded the standard.

[0137] Example 3

[0138] This example provides an environmentally friendly refinish varnish composition, and its specific formulation is shown in Tables 7.1 and 7.2.

[0139] Table 7.1

[0140]

[0141] Table 7.2

[0142] Serial Number Type Component B Curing Agent Example 3 / part 1 Solvent Butyl Acetate 7 2 Solvent Methyl Isobutyl Ketone 2 3 Solvent S-100 Solvent Oil 2.7 4 Auxiliary Agent ADDITIVE TI Monofunctional Isocyanate 0.3 5 Resin Duranate TPA100 Isocyanate 88

[0143] The preparation process of the environmentally friendly refinish varnish composition is as follows:

[0144] First step: Mix materials 10 - 12 in the A-component varnish evenly, and then perform sanding until the fineness is ≤5 μm to prepare an anti-sag sanding slurry.

[0145] Second step: Add materials 1 - 9 of the A-component varnish, the anti-sag sanding slurry from the first step, and materials 13 - 14 in sequence under stirring, and stir evenly to obtain the A-component varnish.

[0146] Third step: Add materials 1 - 5 of the B-component curing agent in sequence under stirring, and stir evenly to obtain the B-component curing agent.

[0147] Fourth step: Mix the A-component varnish and the B-component curing agent evenly according to a volume ratio of 3:1, and use a diluent to adjust the viscosity to the application viscosity, that is, 18 - 20 s / coat - 4 cup (25 °C), to obtain a fast-drying environmentally friendly refinish varnish composition.

[0148] Comparative Example 7

[0149] This comparative example provides a varnish composition, and its specific formulation can be seen in Table 8.1 and Table 8.2.

[0150] Table 8.1

[0151] Serial Number Type Component A Clear Varnish Comparative Example 7 / part 1 Solvent Butyl Acetate 7.3 2 Solvent Methyl Isobutyl Ketone 4.3 3 Solvent S-150 Solvent Oil 2.5 4 Solvent EEP 1.8 5 Acrylic Resin ETERAC 7307A-XS-70 65.5 6 Polyester Resin PRS-1014RESIN 15.68 7 Auxiliary Agent Stannous Octoate 0.02 8 Auxiliary Agent RIASORB UV-292 Light Stabilizer 1 9 Auxiliary Agent AU 1130 UV Absorbent 0.5 10 Auxiliary Agent AEROSIL R202 Fumed Silica 1.2 11 Auxiliary Agent BYK-390 Auxiliary Agent 0.1 12 Auxiliary Agent BYK-326 Auxiliary Agent 0.1

[0152] Table 8.2

[0153] Serial Number Type Component B Curing Agent Comparative Example 7 / part 1 Solvent Butyl Acetate 7 2 Solvent Methyl Isobutyl Ketone 2 3 Solvent S-100 Solvent Oil 2.7 4 Auxiliary Agent ADDITIVE TI Monofunctional Isocyanate 0.3 5 Resin Duranate TPA100 Isocyanate 88

[0154] The preparation process of the varnish composition is as follows:

[0155] The first step: Add varnish materials 1-9 of component A in sequence under stirring, then increase the rotation speed to 1000-1500 rpm, slowly add material 10, and disperse it at high speed for 15-30 min. It is required that its fineness ≤ 10 μm. After mixing evenly, reduce the rotation speed to 500-600 rpm, continue to add materials 11-12, and stir evenly to obtain component A varnish;

[0156] The second step: Add curing agent materials 1-5 of component B in sequence under stirring, and stir evenly to obtain component B curing agent;

[0157] The third step: Mix component A varnish and component B curing agent evenly according to a volume ratio of 3:1, and use a diluent to adjust the viscosity to the construction viscosity, that is, 18-20 s / coat-4 cup (25 °C) to obtain the varnish composition.

[0158] Compare the performance of the varnish compositions obtained in Example 3 and Comparative Example 7. The evaluation method is the same as that in Example 1. The obtained results can be seen in Table 9.

[0159] Table 9

[0160]

[0161]

[0162] As can be seen from the above table, the varnish composition prepared in Example 3 can meet the VOC emission requirements and customer performance requirements. In Comparative Example 7, a high-speed dispersion process is used to disperse the anti-sagging agent, and then automotive refinish varnish is prepared. However, high-speed dispersion cannot fully disperse the anti-sagging agent fumed silica, resulting in the film gloss being lower than the customer requirements, and at the same time, the anti-sagging property is also slightly lower than that in Example 3.

[0163] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, based on the above description, other different forms of changes or modifications can be made. It is impossible to enumerate all the implementation manners here. Any obvious changes or modifications derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A quick-drying environmentally friendly repair varnish composition, characterized in that, it comprises component A and component B; By weight parts, component A comprises 60 - 80 parts of acrylic resin, 5 - 25 parts of polyester resin, 0.02 - 0.5 part of dryer, 0.2 - 0.8 part of leveling agent, 1 - 2 parts of anti-aging aid, 0.5 - 1.5 parts of anti-sagging aid, and 10 - 20 parts of component A solvent; Component B comprises 80 - 100 parts of isocyanate, 0 - 20 parts of component B solvent, and 0.01 - 0.5 part of water remover; Among them, the anti-sagging aid is selected from hydrophobic modified fumed silica; the primary particle average particle size of the fumed silica is 10-20 nm, and the BET surface area is 70-200 m 2 / g.

2. The environmentally friendly repair varnish composition according to claim 1, characterized in that, the anti-sagging aid is selected from at least one of AEROSIL R972 fumed silica, AEROSIL R974 fumed silica, and AEROSIL R202 fumed silica.

3. The environmentally friendly repair varnish composition according to claim 1, characterized in that, the acrylic resin has a solid content of 70 - 80%, a weight average molecular weight of 3000 - 12000, a hydroxyl content of 3 - 7%, and an acid value of 5 - 20 mgKOH / g; the polyester resin is a polyester resin with a highly branched structure and / or hyperbranched structure; the polyester resin has a solid content of 60 - 80%, a hydroxyl value of 200 - 350 mgKOH / g, and a viscosity of 150 - 300 mPa.s / 60 °C.

4. The environmentally friendly repair varnish composition according to claim 1, characterized in that, the acrylic resin is selected from at least one of ACS-1284 acrylic resin, Uracron CY 430E-70 acrylic resin, ETERAC 7307A-XS-70 acrylic resin, AZS-797 acrylic resin, and Nuplex Setalux 1762VV-70 acrylic resin; the polyester resin is selected from at least one of PRS-1014RESIN polyester resin, CAPA 3050 polyester resin, and DURANOLTM T5650E polyester resin.

5. The environmentally friendly repair varnish composition according to claim 1, characterized in that, the dryer is selected from at least one of stannous octoate, dibutyltin dilaurate, and WCAT-WP01; the leveling agent is selected from at least one of BYK-390 additive, BYK-325N additive, BYK-326 additive, BYK-397 additive, and EFKA 3600 leveling agent; the anti-aging aid is selected from at least one of Tinuvin 123 light stabilizer, Omnistab 123 light stabilizer, RIASORB UV-292 light stabilizer, AU 1130 ultraviolet absorber, and Tinuvin 384-2 ultraviolet absorber.

6. The environmentally friendly repair varnish composition according to claim 1, characterized in that, the isocyanate is a weather-resistant isocyanate; preferably HDI trimer and / or IPDI trimer; The water remover is selected from ADDITIVE TI monofunctional isocyanate and / or ADDITIVE OF water remover.

7. The environment-friendly repair varnish composition according to claim 1, wherein, the solvent of component A is selected from at least one of solvent naphtha S-100, solvent naphtha S-150, butyl acetate, methyl isobutyl ketone, xylene, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, and EEP; the solvent of component B is selected from at least one of butyl acetate, solvent naphtha S-100, and methyl isobutyl ketone, and its moisture content ≤ 300 ppm.

8. The preparation method of the environment-friendly repair varnish composition according to any one of claims 1-7, wherein, it includes the following steps: First step, disperse 0.5-1.5 parts of anti-sagging agent into part of acrylic resin and part of the solvent of component A. After uniform dispersion, perform sanding treatment on the obtained premix until the particle fineness ≤ 5 μm to obtain anti-sagging sanding slurry; Second step, under stirring, sequentially add the remaining acrylic resin, 5-25 parts of polyester resin, 0.02-0.5 parts of drier, 0.2-0.8 parts of leveling agent, 1-2 parts of anti-aging agent, and the anti-sagging sanding slurry prepared in the first step into the remaining solvent of component A, and stir evenly to obtain component A; Third step, under stirring, sequentially add 80-100 parts of isocyanate and 0.01-0.5 parts of water remover into 0-20 parts of the solvent of component B, and stir evenly to obtain component B; Fourth step, mix component A and component B according to a volume ratio of 3:1, and then adjust to the construction viscosity with a diluent to obtain the quick-drying environment-friendly repair varnish composition.

9. The preparation method according to claim 8, wherein, in the anti-sagging sanding slurry, the anti-sagging agent, acrylic resin, and the solvent of component A total 100 wt%, wherein the anti-sagging agent accounts for 10-15 wt%, the acrylic resin accounts for 50-70 wt%, and the solvent of component A accounts for 20-35 wt%.

10. The application of the environment-friendly repair varnish composition according to any one of claims 1-7 as an automotive paint.

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