Coating composition as well as preparation method and application thereof

Abstract

The invention discloses a coating composition as well as a preparation method and application thereof, and relates to the technical field of coatings. The coating composition comprises a component A and a component B, the component A is prepared from the following components in parts by mass: 45 to 70 parts of hydroxyl-terminated hyperbranched polyester resin, 10 to 20 parts of acrylic acid modified alkyd resin, 10 to 30 parts of talcum powder, 3 to 6 parts of zinc stearate, 1 to 2 parts of functional additive and 6 to 10 parts of solvent; the component B is prepared from the following components in parts by mass: 40 to 50 parts of TDI (toluene diisocynate) adduct, 10 to 20 parts of TDI tripolymer and 32 to 48 parts of butyl acetate. The coating composition has the effect of no blistering in thick coating, is moderate in drying speed, good in water resistance and flexibility and low in harmful substance content, is beneficial to improving the coating construction efficiency, and is suitable for being used as a primer to be applied to furniture coating.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a coating composition, a preparation method and application thereof. Background Art

[0002] Paint is a material that is applied to the surface of the object to be protected or decorated and can form a firmly adhered continuous film. Paint is usually composed of main ingredients such as resin, oil, emulsion, and auxiliary ingredients such as pigments, fillers and additives that may be added. Primer, as a type of paint, is the first coat of paint directly applied to the surface of the surface-treated parts. It is the beginning of the entire coating. The primer is required to have good adhesion to the substrate and good water resistance and corrosion resistance.

[0003] With the improvement of people's living standards, the quality requirements for household products are getting higher and higher. However, due to the uneven skills of construction workers in the market and different construction environments, ordinary primer coatings are prone to problems such as bubbles, prickly heat, and pinholes in the paint film when the construction thickness reaches 150-200μm, which seriously affects the appearance after painting, and the adhesion, water resistance, corrosion resistance and other properties are reduced, making it difficult to meet the painting requirements of high-end furniture. In addition, traditional primer coatings have certain requirements for the construction environment and construction technology, resulting in low production efficiency. Summary of the invention

[0004] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the object of the present invention is to provide a coating composition, comprising an acrylic modified alkyd resin and a terminal hydroxyl hyperbranched polyester resin, wherein bubbles generated while reacting with isocyanate in TDI can be released in time, achieving the effect of thick coating without bubbling, and ensuring a smooth film surface.

[0005] A second aspect of the present invention is to provide a method for preparing the coating.

[0006] The third aspect of the present invention is to provide a transparent primer.

[0007] A fourth aspect of the present invention is to provide a use of a coating or a transparent primer.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] The first aspect of the present invention provides a coating composition, comprising component A and component B;

[0010] The component A comprises the following components by mass:

[0011] 45-70 parts of terminal hydroxyl hyperbranched polyester resin,

[0012] 10-20 parts of acrylic acid modified alkyd resin,

[0013] 10-30 parts of talcum powder,

[0014] 3-6 parts of zinc stearate,

[0015] 1-2 parts of functional additives,

[0016] 6-10 parts of solvent;

[0017] The B component comprises the following components by mass:

[0018] 40-50 parts of TDI adduct,

[0019] 10-20 parts of TDI trimer,

[0020] 32-48 parts of butyl acetate.

[0021] The coating composition of the present invention has the effect of thick coating without blistering. Among them, the acrylic modified alkyd resin in component A and the terminal hydroxyl hyperbranched polyester resin containing hydroxyl have excellent solvent release. When these two resins react with functional additives and the TDI adduct of component B and the isocyanate of TDI trimer to form polyurethane segments, the bubbles generated by the reaction can be released in time to ensure that the obtained paint film is dense and smooth. In the present invention, the three components of component A, component B and diluent complement each other, can improve the construction performance, thick coating effect, water resistance, alkali resistance of the coating, and reduce the content of harmful substances. The coating is easy to construct and can meet the coating requirements under different environments.

[0022] The zinc stearate in component A can be used as a polishing aid and is also beneficial to the polishing of the coating formed by the coating composition. The TDI trimer in component B is also beneficial to increasing the actual drying speed of the coating formed by the coating composition.

[0023] In some embodiments of the present invention, the mass ratio of the component A to the component B is 1:(0.2-0.6).

[0024] In some embodiments of the present invention, the mass ratio of the component A to the component B is 1:(0.3-0.5).

[0025] In some embodiments of the present invention, the coating composition further comprises a diluent; the mass ratio of the component A to the diluent is 1:(0.4-0.8).

[0026] In some embodiments of the present invention, the mass ratio of the component A to the diluent is 1:(0.5-0.7).

[0027] In some embodiments of the present invention, the functional additive comprises the following components in parts by mass:

[0028] Anti-settling agent 0.8-1.2 parts, defoaming agent 0.1-0.5 parts, drying agent 0.1-0.3 parts.

[0029] In some embodiments of the present invention, the functional additive includes the following components in parts by mass:

[0030] Anti-settling agent 0.8-1 part, defoaming agent 0.1-0.3 part, drying agent 0.1-0.2 part.

[0031] In some embodiments of the present invention, the diluent includes the following components in parts by mass:

[0032] 15-25 parts of xylene, 40-60 parts of butyl acetate, and 25-35 parts of propylene glycol methyl ether acetate.

[0033] In some embodiments of the present invention, the diluent includes the following components in parts by mass:

[0034] 18-22 parts of xylene, 45-55 parts of butyl acetate, 27-33 parts of propylene glycol methyl ether acetate.

[0035] In some embodiments of the present invention, component A of the coating composition includes the following components in parts by mass:

[0036] 45-70 parts of terminal hydroxyl hyperbranched polyester resin,

[0037] 10-20 parts of acrylic acid modified alkyd resin,

[0038] 10-30 parts of talcum powder,

[0039] 3-6 parts of zinc stearate,

[0040] 0.8-1.2 parts of anti-settling agent,

[0041] Defoaming agent 0.1-0.5 parts,

[0042] 0.1-0.3 parts of drying agent,

[0043] 6 to 10 parts of solvent.

[0044] In some embodiments of the present invention, component A of the coating composition includes the following components in parts by mass:

[0045] 50-60 parts of hydroxyl-terminated hyperbranched polyester resin,

[0046] 10-15 parts of acrylic acid modified alkyd resin,

[0047] 10-20 parts of talcum powder,

[0048] 3-5 parts of zinc stearate,

[0049] Anti-settling agent 0.8-1 part,

[0050] Defoaming agent 0.1-0.3 parts,

[0051] 0.1-0.2 parts of drying agent,

[0052] 6 to 10 parts of solvent.

[0053] In some embodiments of the present invention, the component B of the coating composition includes the following components in parts by mass:

[0054] TDI adduct 43-48 parts,

[0055] TDI trimer 13-17 parts,

[0056] 36-45 parts of butyl acetate.

[0057] In some embodiments of the present invention, the solvent is a composite solvent; the composite solvent comprises butyl acetate and propylene glycol methyl ether acetate.

[0058] In some embodiments of the present invention, the mass ratio of butyl acetate to propylene glycol methyl ether acetate is (1-2):1.

[0059] In some specific embodiments of the present invention, the mass ratio of butyl acetate to propylene glycol methyl ether acetate is (1.4-1.6):1.

[0060] In some embodiments of the present invention, in the B component, the free TDI of TDI trimer is ≤0.5%.

[0061] In some embodiments of the present invention, in the B component, the free TDI of TDI trimer is 0-0.5%.

[0062] In some embodiments of the present invention, in the component A, the average particle size of talc is 1200-1300 meshes.

[0063] In some embodiments of the present invention, the viscosity of the coating composition at 25° C. is 10,000 to 20,000 mPa·s.

[0064] In some embodiments of the present invention, the viscosity of the coating composition at 25° C. is 12000-18000 mPa·s.

[0065] In some specific embodiments of the present invention, the viscosity of the coating composition at 25° C. is 12000-14000 mPa·s.

[0066] In some embodiments of the present invention, the particle size of the coating composition is ≤80 μm.

[0067] The second aspect of the present invention provides a method for preparing the coating composition according to the first aspect of the present invention, comprising the following steps:

[0068] The coating is obtained by mixing and dispersing the A component, the B component and the diluent.

[0069] The third aspect of the present invention provides a transparent primer, the raw materials of which include the coating composition described in the first aspect of the present invention.

[0070] In some embodiments of the present invention, the paint film formed by the transparent primer is 10 to 300 μm.

[0071] In some embodiments of the present invention, the paint film formed by the transparent primer is 150-200 μm.

[0072] The fourth aspect of the present invention provides a use of the coating composition described in the first aspect of the present invention or the transparent primer described in the third aspect of the present invention in the field of furniture coating.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] (1) The coating composition obtained by the present invention adopts a combination of a terminal hydroxyl hyperbranched saturated polyester resin and an acrylic acid modified alkyd resin. The resin has a moderate drying speed, good solvent release, good flexibility, and has the effect of no blistering when thickly applied. The 200 μm paint film formed by thick application will not have abnormal appearance such as bubbles, prickly heat, pinholes, etc.; the storage stability is high, and it can be stably stored at 50° C. for 7 days; it has adhesion, dryness resistance, water resistance, alkali resistance, alcohol resistance, and a low content of harmful substances, for example, the benzene content is less than 0.01%, and the harm to the human body is small.

[0075] (2) The coating composition of the present invention has the effect of non-bubbling when thickly applied, has moderate viscosity, moderate drying speed, good construction performance, low requirements on construction conditions, and can improve production efficiency in application. By mixing other components such as diluents in suitable proportions, the construction efficiency in complex environments is significantly improved. The formed paint film has excellent comprehensive performance and low content of harmful substances. It is suitable for use as a primer for painting. The formed primer is suitable for furniture painting and is not easy to cause harm to the human body. DETAILED DESCRIPTION

[0076] The present invention is further described in detail below by specific examples. Unless otherwise specified, the raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial sources or can be obtained by prior art methods. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

[0077] Some of the raw materials used in the following examples and comparative examples of the present invention are described as follows:

[0078] Hydroxyl-terminated hyperbranched saturated polyester resin: 9875, Dachang Resin of Yeshi Chemical Group.

[0079] Acrylic modified alkyd resin: RV8660, Sanben Chemical Technology Co., Ltd.

[0080] TDI adduct curing agent: Desmodur L-75, Bayer Chemical Company, Germany, free TDI, HDI content ≤ 0.5%.

[0081] TDI trimer curing agent: Desmodur IL 1451, Bayer Chemical Company, Germany, free TDI, HDI content ≤ 0.5%.

[0082] Anti-settling agent: bentonite powder, powder particle size ≤50μm, the main component is montmorillonite, purchased from Zhejiang Hongyu New Materials Co., Ltd.

[0083] Defoaming agent: organic siloxane solution, BYK-052 from Germany.

[0084] Drier: Organotin T12; commonly available on the market.

[0085] Zinc stearate: PL-B; commonly available in the market.

[0086] Talc: average particle size is 1250 mesh; commonly purchased from the market.

[0087] Diluent: by mass: 20 parts of xylene, 50 parts of butyl acetate, and 30 parts of propylene glycol methyl ether acetate.

[0088] Composite solvent: butyl acetate and propylene glycol methyl ether acetate in a mass ratio of 1.5:1, namely 60wt% of butyl acetate and 40wt% of propylene glycol methyl ether acetate.

[0089] Example 1

[0090] This embodiment provides a coating composition, including component A, component B and a diluent;

[0091] Among them, component A includes the following components by mass:

[0092] 60 parts of hydroxyl-terminated hyperbranched saturated polyester resin,

[0093] 14.7 parts of acrylic acid modified alkyd resin,

[0094] 1 part of anti-settling agent,

[0095] 0.2 parts of defoaming agent,

[0096] 0.1 part of drying agent,

[0097] 4 parts of zinc stearate,

[0098] 10 parts of talcum powder,

[0099] 10 parts of composite solvent;

[0100] Component B includes the following components by mass:

[0101] 45 parts of TDI adduct curing agent, wherein the solid content of the TDI adduct curing agent is 65%;

[0102] 15 parts of TDI trimer, wherein the solid content of the TDI trimer is 50%;

[0103] 40 parts of butyl acetate;

[0104] The mass ratio of component A, component B and diluent is 1:0.5:0.6.

[0105] The preparation method of the coating composition of this embodiment comprises the following steps:

[0106] The components are sequentially added into a dispersion tank and dispersed at high speed until fully uniform to obtain a coating composition; the viscosity is controlled at 15000±3000 mPa·s at 25°C, and the particle size is controlled at ≤80 μm (the particle size is measured by a scraper fineness meter).

[0107] Example 2

[0108] This embodiment provides a coating composition, including component A, component B and a diluent;

[0109] Among them, component A includes the following components by mass:

[0110] 58 parts of hydroxyl-terminated hyperbranched saturated polyester resin,

[0111] 10 parts of acrylic acid modified alkyd resin,

[0112] 1 part of anti-settling agent,

[0113] 0.2 parts of defoaming agent,

[0114] 0.1 part of drying agent,

[0115] 4 parts of zinc stearate,

[0116] 20 parts of talcum powder,

[0117] 6.7 parts of composite solvent;

[0118] Component B includes the following components by mass:

[0119] 45 parts of TDI adduct curing agent, wherein the solid content of the TDI adduct curing agent is 65%;

[0120] 15 parts of TDI trimer, wherein the solid content of the TDI trimer is 50%;

[0121] 40 parts of butyl acetate;

[0122] The mass ratio of component A, component B and diluent is 1:0.5:0.6.

[0123] The preparation method of the coating composition of this embodiment is the same as that of Example 1.

[0124] Comparative Example 1

[0125] This comparative example provides a coating composition, which comprises the following components in parts by mass:

[0126] Alkyd resin (TOP 3735): 76 parts,

[0127] Dispersant (EFKA4010): 0.2 parts,

[0128] Defoaming agent: 0.2 parts,

[0129] Anti-settling agent: 1 part,

[0130] Zinc stearate: 4 parts,

[0131] Talc: 10 parts,

[0132] Propylene glycol methyl ether acetate: 3 parts,

[0133] Butyl acetate: 5.6 parts.

[0134] The preparation method of the coating composition of this comparative example comprises the following steps: putting each component into a dispersion tank, and dispersing at a high speed of 1500 r / min for 20 minutes until the coating composition is fully uniform.

[0135] Comparative Example 2

[0136] This comparative example provides a coating composition, which comprises the following components in parts by mass:

[0137] Alkyd resin (DSM 3870): 67 parts,

[0138] Dispersant (EFKA4010): 0.2 parts,

[0139] Defoaming agent: 0.2 parts,

[0140] Anti-settling agent: 1 part,

[0141] Zinc stearate: 4 parts,

[0142] Talc: 20 parts,

[0143] Propylene glycol methyl ether acetate: 3 parts,

[0144] Butyl acetate: 4.6 parts.

[0145] The preparation method of the coating composition of this comparative example comprises the following steps: putting each component into a dispersion tank and dispersing at high speed until it is fully uniform.

[0146] Results

[0147] The coating compositions obtained in the above examples and comparative examples were sprayed on a plate, and the ambient temperature during the spraying process was 35° C. and the humidity was 80%, to form a paint film.

[0148] The properties of the coating composition and the paint film are tested using national standards or conventional methods in the field:

[0149] Among them, the leveling property is tested according to GB / T1750-1979 standard; in the leveling property test, very flat and no ripples are judged as excellent;

[0150] Flexibility is tested according to GB / T1731-2020 standard;

[0151] Viscosity is tested according to GB / T2794-2022 standard;

[0152] Finger-pressed dry refers to the time required for the paint film to leave no indentation when pressed with a finger;

[0153] Sandable time refers to the time required for the paint film to dry and be sanded, and is an indicator of drying speed;

[0154] Sandability: Use 240-grit sandpaper to grind out powder, and judge the sandability by the degree to which the powder does not stick to the sandpaper;

[0155] Anti-bubble, prickly heat, and pinhole properties: Visually compare the number of bubbles, prickly heat, and pinholes to make judgments;

[0156] Construction viscosity: measured with a 4-mesh cup, with the same amount of coating composition, high viscosity takes longer to flow out, low viscosity takes shorter time to flow out;

[0157] For other performance indicators, please refer to GB / T23997-2009, and for the limits of hazardous substances, please refer to GB18581-2009; among them, anti-settling property is storage stability.

[0158] The results are shown in Tables 1 to 3 below.

[0159] Table 1 Performance test results of the coating composition of Example 1

[0160]

[0161]

[0162] Table 2 Performance test results of the coating composition of Example 2

[0163]

[0164]

[0165] It can be seen from Tables 1 and 2 above that the coating composition obtained by the present invention can be used as a primer, has good construction performance, and will not show any abnormality in the appearance of the paint film; has high storage stability, and will not show any abnormality even if stored at 50°C for 7 days; has good polishability, and can meet the requirements of different paint film surface gloss; and has adhesion, dry resistance, water resistance, alkali resistance, and alcohol resistance, which can meet the requirements of the primer film of furniture coating, and has a low content of harmful substances, with a benzene content of less than 0.01%, which is less harmful to the human body.

[0166] Table 3 Comparison of coating composition properties of examples and comparative examples

[0167] Project Name Example 1 Example 2 Comparative Example 1 Comparative Example 2 Appearance Slightly yellow sticky Slightly yellow sticky Slightly yellow sticky Slightly yellow sticky Fineness(μm) 35 35 35 35 Viscosity (25℃) 13000mPa·s 13000mPa·s 13000mPa·s 13000mPa·s Construction viscosity 11.06 seconds 10.86 seconds 10.96 seconds 10.90 seconds Touch Dry 10 minutes 11 minutes 10 minutes 10 minutes Coating thickness 200μm 200μm 200μm 200μm Leveling excellent generally generally generally Press dry 1h30min 1h35min 1h35min 1h35min Time to grind 2h25min 2h40min 2h40min 2h30min Polishability excellent good Difference good luster 38 40 35 37 Anti-bubble, anti-prickly heat, anti-pinhole none rare many many Pencil hardness HB HB HB HB Flexibility 1mm 1mm 1mm 1mm Adhesion Level 1 Level 1 Level 1 Level 1 Anti-sinking No precipitation There is precipitation Slight precipitation Slightly delaminated Impact resistance No abnormality No abnormality No abnormality No abnormality

[0168] As can be seen from Table 3, the anti-bubble, prickly heat, pinhole performance, leveling, anti-settling and polishing properties of the coating compositions of Examples 1 and 2 of the present invention are better than those of Comparative Examples 1 and 2, and the obtained paint films have excellent performance, moderate viscosity, good construction performance, and the characteristic of no bubbling when coated with a thickness of 200 μm also makes the coating have low technical and environmental requirements during application, and can improve construction efficiency. It can be seen that the coating composition of the present invention is suitable for application as a primer in furniture coating.

[0169] In summary, the coating composition obtained by the present invention has good construction performance, and the appearance of the 200 μm paint film formed by thick coating will not have abnormalities such as bubbles, prickly heat, and pinholes, and has high storage stability, excellent adhesion, dry resistance, water resistance, alkali resistance, alcohol resistance, low content of harmful substances, and at the same time, the viscosity of the coating composition is moderate, the construction performance is good, and the production efficiency can be improved during application. Therefore, the coating composition of the present invention can be used as a primer, is suitable for furniture coating, and is not easy to cause harm to the human body.

[0170] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A coating composition, It is characterized in that It includes component A and component B; The component A comprises the following components by mass: 45-70 parts of terminal hydroxyl hyperbranched polyester resin, 10-20 parts of acrylic acid modified alkyd resin, 10-30 parts of talcum powder, 3-6 parts of zinc stearate, 1-2 parts of functional additives, 6-10 parts of solvent; The B component comprises the following components by mass: 40-50 parts of TDI adduct, 10-20 parts of TDI trimer, 32-48 parts of butyl acetate.

2. The coating composition according to claim 1, It is characterized in that The mass ratio of the A component to the B component is 1:(0.2-0.6); And / or, the coating composition further comprises a diluent; the mass ratio of the component A to the diluent is 1:(0.4-0.8).

3. The coating composition according to claim 1, It is characterized in that The functional additives include the following components by mass: Anti-settling agent 0.8-1.2 parts, defoaming agent 0.1-0.5 parts, drying agent 0.1-0.3 parts.

4. The coating composition according to claim 1 or 2, It is characterized in that The diluent includes the following components by mass: 15-25 parts of xylene, 40-60 parts of butyl acetate, and 25-35 parts of propylene glycol methyl ether acetate.

5. The coating composition according to claim 1, It is characterized in that The solvent is a composite solvent; the composite solvent comprises butyl acetate and propylene glycol methyl ether acetate; And / or, the mass ratio of butyl acetate to propylene glycol methyl ether acetate is (1-2):

1.

6. The coating composition according to claim 1 or 2, It is characterized in that In the B component, the free TDI of TDI trimer is ≤0.5%.

7. The coating composition according to claim 1 or 2, It is characterized in that The viscosity of the coating composition at 25° C. is 10,000 to 20,000 mPa·s; And / or, the particle size of the coating composition is ≤80 μm.

8. A method for preparing the coating composition according to any one of claims 1 to 7, It is characterized in that The steps include: The A component, the B component and the diluent are mixed and dispersed to obtain the coating composition.

9. A transparent primer, It is characterized in that The raw material of the transparent primer comprises the coating composition according to any one of claims 1 to 7.

10. Use of the coating composition according to any one of claims 1 to 7 or the transparent primer according to claim 9 in the field of furniture coating.

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