Two-component high-solid low-viscosity quick-drying high-fullness varnish and preparation method thereof

Abstract

The invention relates to the technical field of coatings, in particular to a bi-component high-solid low-viscosity quick-drying high-fullness varnish and a preparation method thereof.The bi-component high-solid low-viscosity quick-drying high-fullness varnish is composed of a component A, a component B and a diluent, the component A is a main agent, and the component B is a curing agent; the component A at least comprises the following raw materials in percentage by mass: 60%-75% of hydroxy acrylic resin, 10%-20% of polyester polyol resin, 8%-20% of polyaspartic acid resin, 0.1%-0.3% of a dehydrating agent, 0.1%-0.4% of a defoaming agent, 0.2%-0.5% of an anti-sagging auxiliary agent, 0.5%-1.0% of a flatting agent, 0.05%-0.15% of a drier, 0.4%-0.8% of an ultraviolet light absorber, 0.2%-0.4% of an ultraviolet light stabilizer and the balance of an organic solvent; the preparation of the varnish which is high in construction solid content, low in VOC, quick to dry, long in pot life and good in fullness is achieved, the construction rhythm is met, and the appearance requirement of the varnish is met.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, in particular to a two-component high-solid, low-viscosity, fast-drying, high-fullness varnish and a preparation method thereof. Background Art

[0002] With the development of the automotive industry, coating requirements for commercial vehicles such as passenger cars, construction machinery, and rail transit are becoming more diverse, and the requirements for coating effects are becoming increasingly higher. In addition to the diversified demands for semi-gloss and matte finishes, high-gloss paints are now required to have faster drying speeds and higher fullness. Furthermore, with people paying more attention to environmental protection and increasingly stringent environmental regulations, higher requirements are being placed on the volatile organic compound (VOC) content of traditional solvent-based coatings.

[0003] Traditional high-gloss clearcoats struggle to achieve a balance between high application solids, fast drying, long pot life, and high body. Hydroxyl acrylic resins with higher Tgs offer faster drying, but struggle to achieve both high application solids and good body. Polyasparagine resins offer fast drying and high application solids, but suffer from poor body and a short pot life, with the coating gelling in less than 30 minutes and becoming unusable. A Chinese patent (publication number CN 105949983A) discloses a method for preparing and using a high-solids, fast-drying, scratch-resistant clearcoat composition. This product has a VOC of ≥416 g / L and a DOI of ≤82, but does not disclose drying time or pot life. Its pencil hardness is F or HB, and its xenon lamp aging test is 1000 hours, a level 1 test. Therefore, there is a strong need to develop clearcoats with ultra-high solids, improved environmental friendliness, a higher DOI, and superior weather resistance. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a two-component high-solid, low-viscosity, fast-drying, high-fullness varnish, which realizes the preparation of a varnish with high construction solid content, low VOC, fast drying and a long application period, and good fullness, which meets both the construction rhythm and the appearance requirements of the varnish.

[0005] On one hand, the present invention provides a two-component high-solid, low-viscosity, fast-drying, high-fullness varnish, which is composed of a component A, a component B, and a diluent, wherein the component A is a main agent and the component B is a curing agent; the component A comprises at least the following raw materials, by mass percentage: 60-75% of a hydroxy acrylic resin, 10-20% of a polyester polyol resin, 8-20% of a polyaspartic acid resin, 0.1-0.3% of a dehydrating agent, 0.1-0.4% of a defoaming agent, 0.2-0.5% of an anti-sagging agent, 0.5-1.0% of a leveling agent, 0.05-0.15% of a drying agent, 0.4-0.8% of an ultraviolet light absorber, 0.2-0.4% of an ultraviolet light stabilizer, and the balance being made up of an organic solvent.

[0006] As a preferred technical solution, the ratio of component A, component B and diluent is (1-3):1:(0.1-0.2).

[0007] As a preferred technical solution, the total mass ratio of the polyaspartic acid resin to the hydroxy acrylic resin and the polyester polyol resin is (8-16): (70-85), preferably (8-16): (75-84).

[0008] As a preferred technical solution, the solid content of the hydroxylated acrylic resin is 75wt%-80wt%, the hydroxyl value is 100-150mgKOH / g, and the viscosity (25 1 / s, 23°C, DIN EN ISO 3219, STM 012) is 3000-10000mPa·s, or the solid content of the hydroxylated acrylic resin is 75wt%-80wt%, the acid value is 2-6mgKOH / g, and the viscosity (100 1 / s, 23°C, DIN EN ISO 3219, STM 012J) is 2000-10000mPa·s.

[0009] More preferably, the model of the hydroxylated acrylic resin is SETALUX 1921BA-78 and / or MACRYNAL VSM 2805 / 80BAC.

[0010] As a preferred technical solution, the polyester polyol resin has a solid content of 75wt%-80wt%, a hydroxyl value of 120-200mgKOH / g, and a viscosity (100 1 / s, 23°C, DIN EN ISO 3219, STM 012) of 1300-5000mPa·s, or the hydroxy acrylic resin has a solid content of 75wt%-80wt%, an acid value of 5-12mgKOH / g, and a viscosity (100 1 / s, 23°C, DIN EN ISO 3219, STM 012J) of 1300-5000mPa·s.

[0011] More preferably, the polyester polyol resin is SETAL 168SS-80 or SETAL 1606BA-80 produced by Allnex.

[0012] As a preferred technical solution, the polyaspartic acid resin is a solvent-free resin with an equivalent weight of 250-300 and a viscosity (25°C, M014-ISO 3219 / A.3) of 800-2000 mPa·s, or the polyaspartic acid resin has an equivalent weight of 250-300 and a viscosity (25°C, DIN53019) of 500-3000 mPa·s.

[0013] Further preferably, the polyaspartic acid resin is Covestro NH1520 and / or Covestro NH142.

[0014] As a preferred technical solution, the dehydrating agent is Additive OF.

[0015] As a preferred technical solution, the defoaming agent is an organosilicon defoaming agent, and the preferred model is at least one of BYK-141 and BYK-085.

[0016] As a preferred technical solution, the anti-sagging agent is at least one of Sothix 250 rheological additive and BYK430 anti-sagging agent.

[0017] As a preferred technical solution, the leveling agent is at least one of an acrylate and a silicone leveling agent, preferably at least one of BYK358N, Tego glide450, BYK-310 and BYK-333.

[0018] As a preferred technical solution, the drying agent is Hezhongyuan HC32 catalyst.

[0019] As a preferred technical solution, the ultraviolet light absorber is at least one of Tinuvin 1130 and Tinuvin 400.

[0020] As a preferred technical solution, the ultraviolet light stabilizer is a hindered amine radical scavenger, which is at least one of Tinuvin 249 and Tinuvin 123.

[0021] As a preferred technical solution, the organic solvent is at least one of butyl acetate, propylene glycol methyl ether acetate, and 100# solvent. Preferably, the organic solvent is a mixture of butyl acetate, propylene glycol methyl ether acetate, and 100# solvent oil in a mass ratio of (5-8): (2-5): 1, preferably a mixture of butyl acetate, propylene glycol methyl ether acetate, and 100# solvent oil in a mass ratio of 6:3:1.

[0022] As a preferred technical solution, the component B comprises at least the following raw materials, calculated by mass percentage: 60-75% aliphatic polyisocyanate, 10-15% alicyclic polyisocyanate, 10-20% butyl acetate, and the balance made up of propylene glycol methyl ether acetate.

[0023] As a preferred technical solution, the aliphatic polyisocyanate is an HDI trimer, and the preferred model is at least one of Covestro Desmodur N3600 and Desmodur 3900.

[0024] As a preferred technical solution, the alicyclic polyisocyanate is at least one of Desmodur XP2763 and Desmodur Z4470BA from Covestro.

[0025] As a preferred technical solution, the diluent includes at least the following raw materials, calculated by mass percentage: 45-65% butyl acetate, 15-25% ethyl acetate, 10-20% propylene glycol methyl ether acetate, and 100# solvent oil to make up the balance.

[0026] The present invention optimizes component A into a resin system comprising a hydroxy acrylic resin, a polyester polyol resin, and a polyaspartic acid resin, and further controls the amount of each resin added to component A, effectively balancing the product's trial period, fullness, and polishing time. In particular, the ratio of the polyaspartic acid resin to the total mass of the hydroxy acrylic resin and the polyester polyol resin in the system is controlled to be (8-16):(70-85). Combined with other raw materials in the system, the provided product has excellent overall performance, with a construction solid content exceeding 64%, a construction VOC of ≤380 g / L, an environmentally friendly varnish with a DOI of ≥88, excellent fullness, a drying time of HB hardness of 30 minutes, a final hardness of H, a pot life of ≥1.5 hours, meeting the requirements of fast-paced construction, while maintaining a long pot life and good appearance. After aging under a xenon lamp for 1500 hours, the gloss loss rate is ≤1, and the product has excellent weather resistance.

[0027] Furthermore, the present invention balances the drying speed and curing time as well as the comprehensive properties of the cured paint film by using a curing agent system including aliphatic polyisocyanate and alicyclic polyisocyanate, and an organic solvent and a diluent in the system.

[0028] On the other hand, the present invention provides a method for preparing a two-component high-solid, low-viscosity, fast-drying, high-fullness varnish, which comprises at least the following steps: preparing component A, component B, and a diluent respectively, then mixing and stirring component A, component B, and the diluent evenly, and adjusting the viscosity to 20-30s (applying 4 cups) to obtain a sprayable two-component high-solid, low-viscosity, fast-drying, high-fullness varnish.

[0029] Beneficial effects

[0030] 1. The present invention provides a two-component high-solid, low-viscosity, fast-drying, high-fullness varnish, which achieves high construction solid content, low VOC, fast drying and a long working life. The preparation of the varnish with good fullness meets both the construction rhythm and the appearance requirements of the varnish.

[0031] 2. The present invention optimizes the first component into a resin system comprising hydroxy acrylic resin, polyester polyol resin and polyaspartic acid resin, further controls the addition amount of each resin in the first component, and effectively balances the trial period, fullness and polishing time of the product.

[0032] 3. The total mass ratio of the polyaspartic acid resin to the hydroxy acrylic resin and the polyester polyol resin in the control system is (8-16): (70-85). In combination with other raw materials in the system, the provided product has excellent comprehensive performance, with a construction solid content of more than 64%, a construction VOC of ≤380g / L, and an environmentally friendly varnish with a DOI ≥88 and excellent fullness. The hardness can reach HB after drying in 30 minutes, and the final hardness reaches H. The pot life is ≥1.5 hours, which meets the requirements of fast-paced construction. At the same time, it has a long pot life and a good appearance. The gloss loss rate is ≤level 1 after 1500h of xenon lamp aging, and it has excellent weather resistance.

[0033] 4. The present invention balances the drying speed and curing time as well as the comprehensive properties of the cured paint film by using a curing agent system including aliphatic polyisocyanate and alicyclic polyisocyanate, and an organic solvent and a diluent in the system.

[0034] 5. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish provided by the present invention can be applied by evenly mixing components A and B in proportion, adding appropriate diluents, adjusting the appropriate construction viscosity, and spraying. It is easy to apply, dries quickly, has a long activation period, high fullness, and excellent weather resistance. DETAILED DESCRIPTION

[0035] Examples 1-7

[0036] On the one hand, Examples 1-7 of the present invention provide a two-component high-solid, low-viscosity, fast-drying, high-fullness varnish. The formula is shown in Table 1 in terms of mass percentage.

[0037] Table 1

[0038]

[0039]

[0040] In Table 1, the organic solvent is a mixture of butyl acetate, propylene glycol methyl ether acetate, and 100# solvent oil in a mass ratio of 6:3:1.

[0041] On the other hand, Examples 1-7 of the present invention provide a method for preparing a two-component high-solid, low-viscosity, fast-drying, high-fullness varnish, comprising the following steps: preparing component A, component B, and a diluent respectively according to Table 1, then mixing component A, component B, and the diluent and stirring them evenly, adjusting the viscosity, and obtaining a sprayable two-component high-solid, low-viscosity, fast-drying, high-fullness varnish.

[0042] Performance Testing

[0043] The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish provided in the examples was subjected to the various performance tests listed in Table 2. The test standards and results are shown in Table 2.

[0044] Table 2

[0045]

[0046]

[0047]

Claims

1. A two-component high-solid, low-viscosity, fast-drying, high-fullness varnish, characterized in that: The invention is composed of component A, component B and a diluent, wherein component A is a main agent and component B is a curing agent. Calculated by mass percentage, component A at least includes the following raw materials: 60-75% of hydroxy acrylic resin, 10-20% of polyester polyol resin, 8-20% of polyaspartic acid resin, 0.1-0.3% of dehydrating agent, 0.1-0.4% of defoaming agent, 0.2-0.5% of anti-sagging agent, 0.5-1.0% of leveling agent, 0.05-0.15% of drying agent, 0.4-0.8% of ultraviolet light absorber, 0.2-0.4% of ultraviolet light stabilizer, and the balance is made up of organic solvent.

2. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to claim 1, characterized in that: The total mass ratio of the polyaspartic acid resin to the hydroxy acrylic resin and the polyester polyol resin is (8-16): (70-85).

3. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to claim 1 or 2, characterized in that: The ratio of the component A, the component B and the diluent is (1-3):1:(0.1-0.2).

4. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to claim 3, characterized in that: Calculated by mass percentage, the component B comprises at least the following raw materials: 60-75% of aliphatic polyisocyanate, 10-15% of alicyclic polyisocyanate, 10-20% of butyl acetate, and the balance is made up of propylene glycol methyl ether acetate.

5. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to claim 3, characterized in that: Calculated by mass percentage, the diluent comprises at least the following raw materials: 45-65% of butyl acetate, 15-25% of ethyl acetate, 10-20% of propylene glycol methyl ether acetate, and the balance is made up of 100# solvent oil.

6. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to claim 3, characterized in that: The solid content of the hydroxy acrylic resin is 75wt%-80wt%, and the viscosity is 1300-5000mPa·s.

7. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to claim 3, characterized in that: The polyaspartic acid resin is a solvent-free resin with an equivalent weight of 250-300.

8. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to claim 3, characterized in that: The leveling agent is at least one of acrylate and silicone leveling agent.

9. The two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to claim 3, characterized in that: The organic solvent is at least one of butyl acetate, propylene glycol methyl ether acetate, and 100# solvent.

10. A method for preparing a two-component high-solid, low-viscosity, fast-drying, high-fullness varnish according to any one of claims 1 to 9, characterized in that: At least the following steps are included: Prepare component A, component B and diluent respectively, then mix and stir component A, component B and diluent evenly, adjust the viscosity to 20-30s, and obtain a sprayable two-component high-solid, low-viscosity, fast-drying and high-fullness varnish.

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