Alkali-containing seal primer for UV roller coating of calcium silicate board base material and preparation method of alkali-containing seal primer

Abstract

The invention discloses an alkali-containing seal primer for UV roller coating of a calcium silicate board base material and a preparation method of the alkali-containing seal primer, and belongs to the technical field of UV primer preparation. The seal primer has the characteristics of low UV monomer content, high unsaturated double bond conversion rate, excellent water boiling resistance and alkali resistance of a paint film, good adhesion to a high-density and high-alkali calcium silicate board, and excellent adhesion after a water boiling test. The product is used for a first UV coating process of a high-density and high-alkali-content calcium silicate board, can significantly improve the boiling resistance of a paint film after overall coating, and solves the problems of poor alkali resistance of a UV permeation bottom, falling and pulverization of the paint film in the later period and the like. The UV sealing primer has the advantages of high viscosity (about 5000 CPS), excellent adhesion on a base material, high film forming strength and excellent alkali resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of UV primer preparation, and particularly relates to an alkali-containing sealing primer for UV roller coating of a calcium silicate plate substrate and a preparation method thereof. BACKGROUND

[0002] The first process of UV coating of a calcium silicate plate on the market is a UV penetrating primer. The product formula contains more than 40% of UV monomers. A large amount of low-viscosity UV monomers is used to improve the penetration of the product on the medium-density calcium silicate plate substrate, and the selection and collocation of initiators are used to improve the deep curing of the penetrating primer, so as to ensure the adhesion of the UV coating to the substrate. However, a large amount of UV monomers in the existing UV penetrating primer formula will cause problems such as poor film-forming property of the paint film, low conversion rate of unsaturated double bonds, poor paint film resistance, etc. The common calcium silicate plate can control the PH value of the substrate to be close to neutral through process control, so the alkali resistance of the UV penetrating primer is not high. With the development of the calcium silicate plate market, some manufacturers have launched high-density (the density of the calcium silicate plate in the traditional construction UV penetrating primer process is 1.3-1.5 g / cm 3 ), and the density of the calcium silicate plate substrate is 1.7-1.8 g / cm 3 ). The conventional UV penetrating primer has poor penetration on such a substrate, and the film-forming property is general, which will cause problems such as poor water boiling resistance of the coated product, overall peeling and powdering of the UV paint film in the later period, and cannot meet the performance requirements of the manufacturer for UV coating. The UV roller coating sealing primer cannot meet the performance requirements due to the insufficient alkali resistance of the film-forming material. The customer uses moisture-cured paint or two-component epoxy penetrating primer to solve the problem of the first sealing of the high-density alkali-containing substrate, but such paint cannot be industrialized and continuously produced, which has a great influence on the production capacity and subsequent process continuity of the manufacturer, and the environmental protection of such paint is also a problem compared with UV paint.

[0003] The existing UV penetrating primer cannot effectively penetrate the high-density calcium silicate plate, and the film-forming property is not enough, the resistance is poor, and a strong paint film cannot be formed on the surface of the substrate. SUMMARY

[0004] The primary objective of this invention is to provide an alkali-containing sealing primer for UV roller coating of calcium silicate board substrates. This primer features a low UV monomer content, high unsaturated double bond conversion rate, excellent water and alkali resistance of the coating film, good adhesion to high-density, high-alkali calcium silicate boards, and excellent adhesion even after a water boiling test. When used as the first UV coating process for high-density, high-alkali calcium silicate boards, this product significantly improves the overall water resistance of the coated film and solves problems such as poor alkali resistance, subsequent film peeling, and chalking associated with UV-penetrating primers. It is a UV sealing primer with high viscosity (around 5000 CPS), excellent adhesion to substrates, high film strength, and excellent alkali resistance.

[0005] The second objective of this invention is to provide a method for preparing an alkaline sealing primer for UV roller coating of calcium silicate board substrate. This method employs a purely physical mixing approach, which further ensures the simplification of the preparation process, low energy consumption, and high environmental friendliness.

[0006] This invention is achieved through the following technical solution:

[0007] An alkaline sealing primer for UV roller coating of calcium silicate board substrate is prepared from the following raw materials in the indicated mass fractions:

[0008] The composition includes 45-50 wt% of non-hormonal aromatic polyurethane acrylic resin, 8-15 wt% of two-part A epoxy acrylic resin, 12-18 wt% of isoborneol acrylate, 1-2 wt% of adhesion promoter, 2-3.2 wt% of initiator, 20-25 wt% of filler, and 0.5-1 wt% of excipients.

[0009] Preferably, the adhesion promoter is 2-hydroxyethyl methacrylate phosphate.

[0010] Preferably, the initiator is a mixture of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 2,4,6-trimethylbenzoyldiphenyloxyphosphine in a mass ratio of 1.5-3:0.2-0.5.

[0011] Preferably, the filler is a mixture of talc powder and glass powder in a mass ratio of 1:3.

[0012] Preferably, the excipients are composed of defoamer, dispersant, and anti-settling agent mixed in equal proportions.

[0013] The above-mentioned nine-functional aromatic polyurethane acrylic resin combined with a portion of bisphenol A epoxy acrylic resin ensures excellent film toughness while appropriately reducing the degree of crosslinking of the film, thereby reducing the risk of later film cracking and appropriately reducing formulation costs.

[0014] The monomer used is a monofunctional acrylic monomer: isoborneol acrylate, which helps to improve the adhesion of the coating film to the substrate, increase the double bond conversion rate of the film-forming material, adjust the application viscosity of the formula, and ensure the alkali resistance of the coating.

[0015] The filler is made of talc powder, glass powder and other materials in a ratio of talc powder: glass powder = 1:3, which reduces the curing shrinkage rate of the coating and reduces the instantaneous stress during the curing of the paint film.

[0016] The initiator uses 2-hydroxy-2-methyl-1-phenyl-1-propanone combined with 2,4,6-trimethylbenzoyldiphenyloxyphosphine to achieve a balance between the surface drying and hard drying of the paint film, reducing the difference in curing speed between the upper and lower parts of the coating.

[0017] The adhesion promoter uses 2-hydroxyethyl methacrylate phosphate to ensure the adhesion of the coating to inorganic materials such as calcium silicate, and to ensure that it still has excellent adhesion after boiling water test.

[0018] A method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate includes the following steps:

[0019] S1. Select the nine-hormonal aromatic polyurethane acrylic resin, two parts of A epoxy acrylic resin, adhesion promoter and excipients and put them into the dispersion tank in a certain proportion for the first dispersion. While dispersing, add the filler and continue the high-speed second dispersion.

[0020] S2, then add isobornyl acrylate and initiator in sequence for a third dispersion, and the product is obtained.

[0021] Preferably, in step S1, the first dispersion is performed at a rotation speed of 600-800 rpm for 15-25 minutes.

[0022] Preferably, in step S1, a second dispersion is performed at a high speed of 1500–1800 rpm for 35–45 minutes.

[0023] Preferably, in step S2, the third dispersion is performed for 10 to 15 minutes at a rotation speed of 600 to 800 rpm.

[0024] A method for applying an alkaline sealing primer to a calcium silicate board substrate using UV roller coating involves roller coating the sealing primer onto the alkaline calcium silicate board substrate, followed by roller coating of UV filler putty and transparent primer after semi-drying, sanding treatment, and then roller coating of UV color paint and topcoat to complete the process.

[0025] Compared with the prior art, the present invention has at least the following technical effects:

[0026] This invention provides an alkali-containing sealing primer for UV roller coating of calcium silicate board substrates. This primer features low UV monomer content, high unsaturated double bond conversion rate, excellent water and alkali resistance of the coating film, good adhesion to high-density, high-alkali calcium silicate boards, and maintains excellent adhesion even after a water boiling test. When used as the first UV coating process for high-density, high-alkali calcium silicate boards, this product significantly improves the overall water resistance of the coated film and solves problems such as poor alkali resistance, subsequent film peeling, and chalking associated with UV penetrating primers. It is a UV sealing primer with high viscosity (around 5000 CPS), excellent adhesion to substrates, high film strength, and excellent alkali resistance.

[0027] This alkali-based sealing primer changes the traditional calcium silicate board application process, which uses an ultra-low viscosity UV penetrating primer and instead employs a high viscosity UV sealing primer for the first coat of sealing and adhesion. This is particularly beneficial for high-density (1.65 g / cm³) calcium silicate boards. 3 (and above) Calcium silicate board can effectively solve the problems of poor penetration, poor film formation and poor durability of UV penetrating primer on substrate; compared with conventional UV roller coating sealing primer, this solution uses nine-functional polyurethane acrylic resin combined with monofunctional UV monomers such as IBOA, and compounded with glass powder and fillers with excellent resistance, which can significantly improve the alkali resistance of the coating film while reducing the post-curing of the formula and ensuring the stability of the coating film's later performance.

[0028] The method for preparing an alkaline sealing primer for UV roller coating of calcium silicate board substrate adopts a purely physical mixing method, which further ensures the characteristics of simplified preparation process, low energy consumption and high environmental protection. Detailed Implementation

[0029] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Specific conditions not specified in the examples shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0030] Example 1:

[0031] An alkaline sealing primer for UV roller coating of calcium silicate board substrate is prepared from the following raw materials in the indicated mass fractions:

[0032] The composition includes 45 wt% aromatic polyurethane acrylic resin, 15 wt% two-part A epoxy acrylic resin, 18 wt% isoborneol acrylate, 2 wt% adhesion promoter, 3.2 wt% initiator, 25 wt% filler, and 1 wt% excipients.

[0033] The adhesion promoter is 2-hydroxyethyl methacrylate phosphate.

[0034] The initiator is a mixture of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 2,4,6-trimethylbenzoyldiphenyloxyphosphine in a mass ratio of 1.5:0.2.

[0035] The filler is a mixture of talc powder and glass powder in a mass ratio of 1:3.

[0036] The excipients are composed of defoamer, dispersant, and anti-settling agent mixed in equal proportions.

[0037] A method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate includes the following steps:

[0038] S1. Select the nine-hormonal aromatic polyurethane acrylic resin, two parts of A epoxy acrylic resin, adhesion promoter and excipients and put them into the dispersion tank in a certain proportion for the first dispersion. While dispersing, add the filler and continue the high-speed second dispersion.

[0039] S2, then add isobornyl acrylate and initiator in sequence for a third dispersion, and the product is obtained.

[0040] In step S1, the first dispersion is carried out at a rotation speed of 600 rpm for 25 minutes.

[0041] In step S1, a second dispersion is performed at a high speed of 1800 rpm for 35 minutes.

[0042] In step S2, a third dispersion is performed for 10 minutes at a rotation speed of 800 rpm.

[0043] A method for applying an alkaline sealing primer to a calcium silicate board substrate using UV roller coating involves roller coating the sealing primer onto the alkaline calcium silicate board substrate, followed by roller coating of UV filler putty and transparent primer after semi-drying, sanding treatment, and then roller coating of UV color paint and topcoat to complete the process.

[0044] Example 2:

[0045] An alkaline sealing primer for UV roller coating of calcium silicate board substrate is prepared from the following raw materials in the indicated mass fractions:

[0046] The composition includes 45 wt% aromatic polyurethane acrylic resin, 15 wt% two-part A epoxy acrylic resin, 18 wt% isoborneol acrylate, 2 wt% adhesion promoter, 3.2 wt% initiator, 25 wt% filler, and 1 wt% excipients.

[0047] The adhesion promoter is 2-hydroxyethyl methacrylate phosphate.

[0048] The initiator is a mixture of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 2,4,6-trimethylbenzoyldiphenyloxyphosphine in a mass ratio of 3:0.5.

[0049] The filler is a mixture of talc powder and glass powder in a mass ratio of 1:3.

[0050] The excipients are composed of defoamer, dispersant, and anti-settling agent mixed in equal proportions.

[0051] A method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate includes the following steps:

[0052] S1. Select the nine-hormonal aromatic polyurethane acrylic resin, two parts of A epoxy acrylic resin, adhesion promoter and excipients and put them into the dispersion tank in a certain proportion for the first dispersion. While dispersing, add the filler and continue the high-speed second dispersion.

[0053] S2, then add isobornyl acrylate and initiator in sequence for a third dispersion, and the product is obtained.

[0054] In step S1, the first dispersion is carried out at a rotation speed of 800 rpm for 15 minutes.

[0055] In step S1, a second dispersion is performed at a high speed of 1500 rpm for 35 minutes.

[0056] In step S2, a third dispersion is performed for 10 minutes at a rotation speed of 6000 rpm.

[0057] A method for applying an alkaline sealing primer to a calcium silicate board substrate using UV roller coating involves roller coating the sealing primer onto the alkaline calcium silicate board substrate, followed by roller coating of UV filler putty and transparent primer after semi-drying, sanding treatment, and then roller coating of UV color paint and topcoat to complete the process.

[0058] Example 3:

[0059] An alkaline sealing primer for UV roller coating of calcium silicate board substrate is prepared from the following raw materials in the indicated mass fractions:

[0060] The composition includes 50 wt% aromatic polyurethane acrylic resin, 8 wt% two-part A epoxy acrylic resin, 12 wt% isoborneol acrylate, 1 wt% adhesion promoter, 2 wt% initiator, 20 wt% filler, and 0.5 wt% excipients.

[0061] The adhesion promoter is 2-hydroxyethyl methacrylate phosphate.

[0062] The initiator is a mixture of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 2,4,6-trimethylbenzoyldiphenyloxyphosphine in a mass ratio of 1.5:0.5.

[0063] The filler is a mixture of talc powder and glass powder in a mass ratio of 1:3.

[0064] The excipients are composed of defoamer, dispersant, and anti-settling agent mixed in equal proportions.

[0065] A method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate includes the following steps:

[0066] S1. Select the nine-hormonal aromatic polyurethane acrylic resin, two parts of A epoxy acrylic resin, adhesion promoter and excipients and put them into the dispersion tank in a certain proportion for the first dispersion. While dispersing, add the filler and continue the high-speed second dispersion.

[0067] S2, then add isobornyl acrylate and initiator in sequence for a third dispersion, and the product is obtained.

[0068] In step S1, the first dispersion is carried out at a rotation speed of 600 rpm for 25 minutes.

[0069] In step S1, a second dispersion is performed at a high speed of 1800 rpm for 35 minutes.

[0070] In step S2, a third dispersion is performed for 10 minutes at a rotation speed of 800 rpm.

[0071] A method for applying an alkaline sealing primer to a calcium silicate board substrate using UV roller coating involves roller coating the sealing primer onto the alkaline calcium silicate board substrate, followed by roller coating of UV filler putty and transparent primer after semi-drying, sanding treatment, and then roller coating of UV color paint and topcoat to complete the process.

[0072] Example 4:

[0073] An alkaline sealing primer for UV roller coating of calcium silicate board substrate is prepared from the following raw materials in the indicated mass fractions:

[0074] The composition includes 50 wt% aromatic polyurethane acrylic resin, 8 wt% two-part A epoxy acrylic resin, 12 wt% isoborneol acrylate, 1 wt% adhesion promoter, 2 wt% initiator, 20 wt% filler, and 0.5 wt% excipients.

[0075] The adhesion promoter is 2-hydroxyethyl methacrylate phosphate.

[0076] The initiator is a mixture of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 2,4,6-trimethylbenzoyldiphenyloxyphosphine in a mass ratio of 3:0.2.

[0077] The filler is a mixture of talc powder and glass powder in a mass ratio of 1:3.

[0078] The excipients are composed of defoamer, dispersant, and anti-settling agent mixed in equal proportions.

[0079] A method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate includes the following steps:

[0080] S1. Select the nine-hormonal aromatic polyurethane acrylic resin, two parts of A epoxy acrylic resin, adhesion promoter and excipients and put them into the dispersion tank in a certain proportion for the first dispersion. While dispersing, add the filler and continue the high-speed second dispersion.

[0081] S2, then add isobornyl acrylate and initiator in sequence for a third dispersion, and the product is obtained.

[0082] In step S1, the first dispersion is carried out at a rotation speed of 800 rpm for 15 minutes.

[0083] In step S1, a second dispersion is performed at a high speed of 1500 rpm for 35 minutes.

[0084] In step S2, a third dispersion is performed for 10 minutes at a rotation speed of 6000 rpm.

[0085] A method for applying an alkaline sealing primer to a calcium silicate board substrate using UV roller coating involves roller coating the sealing primer onto the alkaline calcium silicate board substrate, followed by roller coating of UV filler putty and transparent primer after semi-drying, sanding treatment, and then roller coating of UV color paint and topcoat to complete the process.

[0086] Comparative Example 1: The raw materials used were non-functional polyurethane acrylic resin and 1173 initiator, which were mixed at a mass ratio of 95:5.

[0087] Comparative Example 2: The raw materials used were bisphenol A epoxy acrylate resin and 1173 initiator, which were mixed at a mass ratio of 95:5.

[0088] Comparative Example 3: The raw materials used were difunctional polyester acrylic resin and 1173 initiator, which were mixed at a mass ratio of 95:5.

[0089] Test 1: Verify the water resistance and alkali resistance of the nine-functional aromatic polyurethane acrylic resin and bisphenol A epoxy acrylic resin individually.

[0090] The results are as follows:

[0091]

[0092]

[0093] The results show that the nonafunctional aromatic polyurethane acrylic resin has better alkali resistance and water boiling resistance than the two-component A epoxy acrylic resin. In contrast, the conventional difunctional polyester acrylic resin has poor alkali resistance and water boiling resistance after film formation due to its lower glass transition temperature, lower double bond content, and lack of branched molecular structure.

[0094] Because the price of polyurethane acrylic resin is relatively high and it has an extremely high degree of crosslinking, if the film thickness is too thick (more than 50um) during testing, the film is very prone to cracking. Therefore, it is combined with some bisphenol A epoxy acrylic resin to ensure excellent film toughness while appropriately reducing the degree of crosslinking, reducing the risk of later film cracking and appropriately reducing the formulation cost.

[0095] Test 2: Performance comparison of moisture-cured, epoxy-sealed, and UV-sealed substrates of this invention after coating on alkali-containing calcium silicate boards:

[0096]

[0097]

[0098] Before testing, the calcium silicate board substrate was thoroughly moistened with water. After 24 hours, pH test paper was used to test the pH value, which was found to be between 9 and 10.

[0099] As can be seen from the table above, compared with traditional moisture-curing sealing bases and epoxy sealing bases, the sealing base of Example 1 of the present invention has the advantages of not being affected by the activation period, not being affected by the ambient temperature and humidity, being able to be used continuously and drying instantly, being suitable for mechanized and continuous production, and being able to significantly improve production efficiency and reduce production costs.

[0100] Conclusion: Compared with conventional UV permeable substrates, this solution has the advantages of excellent film-forming properties and strong alkali resistance and water resistance;

[0101] Compared to conventional UV roller coating with poor adhesion, this solution features excellent alkali resistance, slight post-curing, and stable performance.

[0102] Compared to moisture-curing coatings and two-component epoxy penetrating primers, this solution has advantages such as continuous equipment production, high enterprise production efficiency, minimal impact on subsequent processes, and more environmentally friendly coatings.

[0103] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An alkali-containing sealing primer for UV roller coating of calcium silicate board substrate, characterized in that, It is prepared from raw materials with the following mass fractions: The composition includes 45-50 wt% of non-hormonal aromatic polyurethane acrylic resin, 8-15 wt% of two-part A epoxy acrylic resin, 12-18 wt% of isoborneol acrylate, 1-2 wt% of adhesion promoter, 2-3.2 wt% of initiator, 20-25 wt% of filler, and 0.5-1 wt% of excipients.

2. The alkaline sealing primer for UV roller coating of calcium silicate board substrate according to claim 1, characterized in that, The adhesion promoter is 2-hydroxyethyl methacrylate phosphate.

3. The alkaline sealing primer for UV roller coating of calcium silicate board substrate according to claim 1, characterized in that, The initiator is a mixture of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 2,4,6-trimethylbenzoyldiphenyloxyphosphine in a mass ratio of 1.5-3:0.2-0.

5.

4. The alkaline sealing primer for UV roller coating of calcium silicate board substrate according to claim 1, characterized in that, The filler is a mixture of talc powder and glass powder in a mass ratio of 1:

3.

5. An alkali-containing sealing primer for UV roller coating of calcium silicate board substrate according to claim 1, characterized in that, The excipients are composed of defoamer, dispersant, and anti-settling agent mixed in equal proportions.

6. A method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate as described in claim 1, characterized in that, Includes the following steps: S1. Select the nine-hormonal aromatic polyurethane acrylic resin, two parts of A epoxy acrylic resin, adhesion promoter and excipients and put them into the dispersion tank in a certain proportion for the first dispersion. While dispersing, add the filler and continue the high-speed second dispersion. S2, then add isobornyl acrylate and initiator in sequence for a third dispersion, and the product is obtained.

7. The method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate according to claim 6, characterized in that, In step S1, the first dispersion is carried out at a rotation speed of 600-800 rpm for 15-25 minutes.

8. The method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate according to claim 6, characterized in that, In step S1, a second dispersion is performed at a high speed of 1500–1800 rpm for 35–45 minutes.

9. The method for preparing an alkali-containing sealing primer for UV roller coating of calcium silicate board substrate according to claim 6, characterized in that, In step S2, a third dispersion is performed for 10 to 15 minutes at a rotation speed of 600 to 800 rpm.

10. A method for applying an alkali-containing sealing primer to a calcium silicate board substrate using UV roller coating, characterized in that, The sealing primer is applied by roller to the alkaline calcium silicate board substrate. After it is semi-dry, UV filling putty and transparent primer are applied by roller. After sanding, UV color paint and topcoat are applied by roller to complete the process.

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