阅读说明：本技术 一种双丙聚氨酯耐候漆的制备方法 (Preparation method of polypropylene-polyurethane weather-resistant paint ) 是由 陆天献 于 2021-09-09 设计创作，主要内容包括：本发明公开了一种双丙聚氨酯耐候漆的制备方法,包括以下步骤：将聚氨酯乳液、改性富勒烯与去离子水混合后,升温得到预聚体乳液；将引发剂溶液、单体分散液依次加入到所述预聚体乳液中；冷却至室温后,调节pH至7-9,加入混合交联剂,搅拌均匀后研磨,过滤,即可。本发明通过采用有机硅改性两性水性聚氨酯乳液、表面修饰有二巯基的富勒烯以及采用合理的软、硬单体及混合交联剂比例,可以提升混凝土表面涂层的耐磨、耐老化以及耐腐蚀性能。其中,表面修饰有二巯基的富勒烯由于具有球形外形和二巯基结构,不但提升反应过程中各种单体之间的反应效果,且本身可以参与到反应中从而形成涂层骨架,显著提升表面涂层的耐老化、耐磨以及耐腐蚀性能。(The invention discloses a preparation method of a polypropylene-polyurethane weather-resistant paint, which comprises the following steps: mixing the polyurethane emulsion, the modified fullerene and deionized water, and heating to obtain a prepolymer emulsion; sequentially adding an initiator solution and a monomer dispersion liquid into the prepolymer emulsion; cooling to room temperature, adjusting pH to 7-9, adding mixed crosslinking agent, stirring, grinding, and filtering. According to the invention, the wear-resisting, ageing-resisting and corrosion-resisting properties of the concrete surface coating can be improved by adopting the organic silicon modified amphoteric waterborne polyurethane emulsion, the fullerene with the dimercapto modified on the surface and the reasonable proportion of the soft monomer, the hard monomer and the mixed cross-linking agent. The fullerene with the surface modified with the dimercapto has a spherical shape and a dimercapto structure, so that the reaction effect among various monomers in the reaction process is improved, and the fullerene can participate in the reaction to form a coating framework, and the aging resistance, the wear resistance and the corrosion resistance of the surface coating are obviously improved.)

1. The preparation method of the polypropylene-polyurethane weather-resistant paint is characterized by comprising the following steps:

(1) mixing the polyurethane emulsion, the modified fullerene and deionized water, and heating to 70-90 ℃ to obtain prepolymer emulsion;

(2) mixing a soft monomer and a hard monomer with deionized water to obtain a monomer dispersion liquid;

(3) mixing an initiator with deionized water to obtain an initiator solution;

(4) sequentially adding the initiator solution and the monomer dispersion liquid into the prepolymer emulsion, and reacting for 60-90min to obtain a water emulsion;

(5) and after the aqueous emulsion is cooled to room temperature, adjusting the pH value to 7-9, adding a mixed cross-linking agent, uniformly stirring, grinding and filtering to obtain the aqueous emulsion.

2. The method for preparing a weather-resistant paint of dipropylene polyurethane according to claim 1, wherein in the step (1), the polyurethane emulsion is a silicone-modified amphoteric waterborne polyurethane emulsion.

3. The method for preparing a weather-resistant paint of dipropylene polyurethane according to claim 1, wherein in the step (1), the modified fullerene is a fullerene with a dimercapto group modified on the surface.

4. The method for preparing a di-propyl polyurethane weather-resistant paint according to claim 1, wherein in the step (2), the soft monomer is any one or more than two of n-butyl acrylate, isooctyl acrylate, ethyl acrylate and 2-ethylhexyl methacrylate.

5. The method for preparing a weather-resistant paint of dipropylene polyurethane according to claim 1, wherein in the step (2), the hard monomer is a mixture of methyl methacrylate and one or both of styrene or vinyl acetate.

6. The method for preparing a weather-resistant paint of dipropylene polyurethane according to claim 1, wherein in the step (3), the initiator is any one of ammonium persulfate, sodium persulfate, and potassium persulfate.

7. The method for preparing a weather resistant paint of dipropylene polyurethane according to claim 1, wherein in the step (5), the mixed crosslinking agent is a mixture of adipic acid dihydrazide, N-methylol acrylamide and itaconic acid.

8. The method for preparing a weather-resistant bis-propyl polyurethane paint according to claim 7, wherein the weight ratio of adipic acid dihydrazide, N-methylol acrylamide and itaconic acid in the mixed cross-linking agent is 100: (4-7): (2-5).

9. The process for preparing a weather-resistant paint of dipropylene polyurethane according to any one of claims 1 to 8, wherein the weather-resistant paint of dipropylene polyurethane comprises the following components in parts by weight: 25-35 parts of polyurethane emulsion, 0.2-0.5 part of modified fullerene, 18-25 parts of soft monomer, 5-12 parts of hard monomer, 0.2-0.3 part of initiator, 3-8 parts of mixed cross-linking agent and 38-45 parts of deionized water.

10. A process for preparing a weather-resistant paint of dipropylene polyurethane according to any one of claims 1 to 9, the weather-resistant paint of dipropylene polyurethane prepared by the process.

Technical Field

The invention relates to the technical field of environment-friendly paint, and particularly relates to a preparation method of polypropylene polyurethane weather-resistant paint.

Background

The polypropylene polyurethane weather-resistant paint is also called permeable concrete finish paint, or permeable concrete protective agent, permeable concrete finish paint and the like. It is an important technical proposal in the industry as a pervious concrete surface protective agent because of its high performance of wear resistance, durability, and difficult generation of bubbles at high ground temperature.

The Chinese invention patent CN112574658A discloses a polypropylene-based polyurethane weather-resistant paint, which is prepared by adding a curing agent with a branched structure, stable structure and excellent ultraviolet resistance; the weather-resistant paint has multiple free functional groups, can be quickly cured and forms a stable structure, so that the weather-resistant paint has excellent aging resistance and wear resistance. However, the weather-resistant paint has poor performance in the aspects of chlorine ion penetration resistance and the like after seawater immersion resistance, so that a preparation method of the polypropylene-based polyurethane weather-resistant paint with better erosion resistance needs to be researched.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a preparation method of a dipropylene polyurethane weather-resistant paint.

The technical scheme of the invention is as follows:

a preparation method of a polypropylene-polyurethane weather-resistant paint comprises the following steps:

(1) mixing the polyurethane emulsion, the modified fullerene and deionized water, and heating to 70-90 ℃ to obtain prepolymer emulsion;

(2) mixing a soft monomer and a hard monomer with deionized water to obtain a monomer dispersion liquid;

(3) mixing an initiator with deionized water to obtain an initiator solution;

(4) sequentially adding the initiator solution and the monomer dispersion liquid into the prepolymer emulsion, and reacting for 60-90min to obtain a water emulsion;

(5) and after the aqueous emulsion is cooled to room temperature, adjusting the pH value to 7-9, adding a mixed cross-linking agent, uniformly stirring, grinding and filtering to obtain the aqueous emulsion.

Preferably, in the step (1), the polyurethane emulsion is an organosilicon modified amphoteric waterborne polyurethane emulsion.

The preparation method of the organic silicon modified amphoteric waterborne polyurethane emulsion refers to the Chinese invention patent CN104292414A example 1.

Preferably, in the step (1), the modified fullerene is a fullerene with a dimercapto group modified on the surface.

The preparation method of the fullerene with the surface modified with dimercapto refers to the embodiment 1 of the Chinese patent CN 111808444A.

Preferably, in the step (2), the soft monomer is any one or more of n-butyl acrylate, isooctyl acrylate, ethyl acrylate and 2-ethylhexyl methacrylate.

Preferably, in the step (2), the hard monomer is a mixture of methyl methacrylate and one or two of styrene or vinyl acetate.

Preferably, in the step (3), the initiator is any one of ammonium persulfate, sodium persulfate and potassium persulfate.

Preferably, in the step (5), the mixed crosslinking agent is a mixture of adipic acid dihydrazide, N-methylol acrylamide and itaconic acid.

Further preferably, in the mixed crosslinking agent, the weight ratio of adipic acid dihydrazide, N-methylolacrylamide and itaconic acid is 100: (4-7): (2-5).

Preferably, the polypropylene-based polyurethane weather-resistant paint consists of the following components in parts by weight: 25-35 parts of polyurethane emulsion, 0.2-0.5 part of modified fullerene, 18-25 parts of soft monomer, 5-12 parts of hard monomer, 0.2-0.3 part of initiator, 3-8 parts of mixed cross-linking agent and 38-45 parts of deionized water.

The invention has the advantages that: according to the preparation method of the polypropylene-based polyurethane weather-resistant paint, the wear resistance, the aging resistance and the corrosion resistance of the concrete surface coating can be improved by adopting the organic silicon modified amphoteric waterborne polyurethane emulsion, the fullerene with the surface modified with the dimercapto and the reasonable proportion of the soft monomer, the hard monomer and the mixed cross-linking agent. The fullerene with the surface modified with the dimercapto has a spherical shape and a dimercapto structure, so that the reaction effect among various monomers in the reaction process is improved, and the fullerene can participate in the reaction to form a coating framework, and the aging resistance, the wear resistance and the corrosion resistance of the surface coating are obviously improved.

Detailed Description

In the present invention, all parts and percentages are by weight, unless otherwise specified, and the equipment and materials used are commercially available or commonly used in the art. The quantitative data in the following examples were set up in triplicate and the results averaged.

Example 1

A preparation method of a polypropylene-polyurethane weather-resistant paint comprises the following steps:

(1) mixing the polyurethane emulsion, the modified fullerene and deionized water, and heating to 85 ℃ to obtain prepolymer emulsion;

(2) mixing a soft monomer and a hard monomer with deionized water to obtain a monomer dispersion liquid;

(3) mixing an initiator with deionized water to obtain an initiator solution;

(4) adding the initiator solution and the monomer dispersion liquid into the prepolymer emulsion in sequence, and reacting for 80min to obtain a water emulsion; the addition time of the monomer dispersion liquid is 115 min;

(5) and after the aqueous emulsion is cooled to room temperature, adjusting the pH value to 8.5, adding a mixed cross-linking agent, uniformly stirring, grinding and filtering to obtain the aqueous emulsion.

In the step (1), the polyurethane emulsion is organosilicon modified amphoteric waterborne polyurethane emulsion. The modified fullerene is fullerene with the surface modified with dimercapto.

The preparation method of the organic silicon modified amphoteric waterborne polyurethane emulsion refers to the Chinese invention patent CN104292414A example 1. The preparation method of the fullerene with the surface modified with dimercapto refers to the embodiment 1 of the Chinese patent CN 111808444A.

In the step (2), the soft monomer is a mixture of n-butyl acrylate, isooctyl acrylate and 2-ethylhexyl methacrylate with a molar ratio of 1:3: 1.

In the step (2), the hard monomer is a mixture of methyl methacrylate and vinyl acetate in a mass ratio of 3: 1.

In the step (3), the initiator is potassium persulfate.

In the step (5), the mixed crosslinking agent is a mixture of adipic acid dihydrazide, N-methylolacrylamide and itaconic acid. In the mixed crosslinking agent, the weight ratio of adipic acid dihydrazide, N-hydroxymethyl acrylamide and itaconic acid is 100: 5: 3.

the polypropylene-polyurethane weather-resistant paint comprises the following components in parts by weight: 32 parts of polyurethane emulsion, 0.3 part of modified fullerene, 20 parts of soft monomer, 7 parts of hard monomer, 0.25 part of initiator, 5 parts of mixed cross-linking agent and 41 parts of deionized water.

Example 2

A preparation method of a polypropylene-polyurethane weather-resistant paint comprises the following steps:

(1) mixing the polyurethane emulsion, the modified fullerene and deionized water, and heating to 80 ℃ to obtain prepolymer emulsion;

(2) mixing a soft monomer and a hard monomer with deionized water to obtain a monomer dispersion liquid;

(3) mixing an initiator with deionized water to obtain an initiator solution;

(4) sequentially adding the initiator solution and the monomer dispersion liquid into the prepolymer emulsion, and reacting for 90min to obtain a water emulsion; the addition time of the monomer dispersion liquid is 105 min;

(5) and after the aqueous emulsion is cooled to room temperature, adjusting the pH value to 7.8, adding a mixed cross-linking agent, uniformly stirring, grinding and filtering to obtain the aqueous emulsion.

In the step (1), the polyurethane emulsion is organosilicon modified amphoteric waterborne polyurethane emulsion. The modified fullerene is fullerene with the surface modified with dimercapto.

The preparation method of the organic silicon modified amphoteric waterborne polyurethane emulsion refers to the Chinese invention patent CN104292414A example 1. The preparation method of the fullerene with the surface modified with dimercapto refers to the embodiment 1 of the Chinese patent CN 111808444A.

In the step (2), the soft monomer is n-butyl acrylate and 2-ethylhexyl methacrylate, and the molar ratio of the soft monomer to the n-butyl acrylate to the 2-ethylhexyl methacrylate is 3: 2.

In the step (2), the hard monomer is a mixture of methyl methacrylate and styrene in a mass ratio of 4: 1.

In the step (3), the initiator is sodium persulfate.

In the step (5), the mixed crosslinking agent is a mixture of adipic acid dihydrazide, N-methylolacrylamide and itaconic acid. In the mixed crosslinking agent, the weight ratio of adipic acid dihydrazide, N-hydroxymethyl acrylamide and itaconic acid is 100: 7: 5.

the polypropylene-polyurethane weather-resistant paint comprises the following components in parts by weight: 25 parts of polyurethane emulsion, 0.4 part of modified fullerene, 25 parts of soft monomer, 8 parts of hard monomer, 0.2 part of initiator, 5 parts of mixed cross-linking agent and 45 parts of deionized water.

Example 3

A preparation method of a polypropylene-polyurethane weather-resistant paint comprises the following steps:

(1) mixing the polyurethane emulsion, the modified fullerene and deionized water, and heating to 82 ℃ to obtain prepolymer emulsion;

(2) mixing a soft monomer and a hard monomer with deionized water to obtain a monomer dispersion liquid;

(3) mixing an initiator with deionized water to obtain an initiator solution;

(4) adding the initiator solution and the monomer dispersion liquid into the prepolymer emulsion in sequence, and reacting for 80min to obtain a water emulsion; the adding time of the monomer dispersion liquid is 110 min;

(5) and after the aqueous emulsion is cooled to room temperature, adjusting the pH value to 7.5, adding a mixed cross-linking agent, uniformly stirring, grinding and filtering to obtain the aqueous emulsion.

In the step (1), the polyurethane emulsion is organosilicon modified amphoteric waterborne polyurethane emulsion. The modified fullerene is fullerene with the surface modified with dimercapto.

The preparation method of the organic silicon modified amphoteric waterborne polyurethane emulsion refers to the Chinese invention patent CN104292414A example 1. The preparation method of the fullerene with the surface modified with dimercapto refers to the embodiment 1 of the Chinese patent CN 111808444A.

In the step (2), the soft monomer is a mixture of n-butyl acrylate, isooctyl acrylate and ethyl acrylate in a molar ratio of 4:2: 1.

In the step (2), the hard monomer is a mixture of methyl methacrylate and vinyl acetate in a mass ratio of 8: 3.

In the step (3), the initiator is potassium persulfate.

In the step (5), the mixed crosslinking agent is a mixture of adipic acid dihydrazide, N-methylolacrylamide and itaconic acid. In the mixed crosslinking agent, the weight ratio of adipic acid dihydrazide, N-hydroxymethyl acrylamide and itaconic acid is 100: 4: 2.5.

the polypropylene-polyurethane weather-resistant paint comprises the following components in parts by weight: 30 parts of polyurethane emulsion, 0.2 part of modified fullerene, 25 parts of soft monomer, 8 parts of hard monomer, 0.3 part of initiator, 3 parts of mixed cross-linking agent and 41 parts of deionized water.

Example 4

A preparation method of a polypropylene-polyurethane weather-resistant paint comprises the following steps:

(1) mixing the polyurethane emulsion, the modified fullerene and deionized water, and heating to 70 ℃ to obtain prepolymer emulsion;

(2) mixing a soft monomer and a hard monomer with deionized water to obtain a monomer dispersion liquid;

(3) mixing an initiator with deionized water to obtain an initiator solution;

(4) sequentially adding the initiator solution and the monomer dispersion liquid into the prepolymer emulsion, and reacting for 90min to obtain a water emulsion; the addition time of the monomer dispersion liquid is 90 min;

(5) and after the aqueous emulsion is cooled to room temperature, adjusting the pH value to 8.8, adding a mixed cross-linking agent, uniformly stirring, grinding and filtering to obtain the aqueous emulsion.

In the step (1), the polyurethane emulsion is organosilicon modified amphoteric waterborne polyurethane emulsion. The modified fullerene is fullerene with the surface modified with dimercapto.

The preparation method of the organic silicon modified amphoteric waterborne polyurethane emulsion refers to the Chinese invention patent CN104292414A example 1. The preparation method of the fullerene with the surface modified with dimercapto refers to the embodiment 1 of the Chinese patent CN 111808444A.

In the step (2), the soft monomer is a mixture of n-butyl acrylate, isooctyl acrylate, ethyl acrylate and 2-ethylhexyl methacrylate with a molar ratio of 8:2:3: 1.

In the step (2), the hard monomer is a mixture of methyl methacrylate and vinyl acetate in a mass ratio of 2: 1.

In the step (3), the initiator is sodium persulfate.

In the step (5), the mixed crosslinking agent is a mixture of adipic acid dihydrazide, N-methylolacrylamide and itaconic acid. In the mixed crosslinking agent, the weight ratio of adipic acid dihydrazide, N-hydroxymethyl acrylamide and itaconic acid is 100: 4: 5.

the polypropylene-polyurethane weather-resistant paint comprises the following components in parts by weight: 25 parts of polyurethane emulsion, 0.5 part of modified fullerene, 18 parts of soft monomer, 12 parts of hard monomer, 0.2 part of initiator, 8 parts of mixed cross-linking agent and 38 parts of deionized water.

Example 5

A preparation method of a polypropylene-polyurethane weather-resistant paint comprises the following steps:

(1) mixing the polyurethane emulsion, the modified fullerene and deionized water, and heating to 90 ℃ to obtain prepolymer emulsion;

(2) mixing a soft monomer and a hard monomer with deionized water to obtain a monomer dispersion liquid;

(3) mixing an initiator with deionized water to obtain an initiator solution;

(4) sequentially adding the initiator solution and the monomer dispersion liquid into the prepolymer emulsion, and reacting for 60min to obtain a water emulsion; the addition time of the monomer dispersion liquid is 120 min;

(5) and after the aqueous emulsion is cooled to room temperature, adjusting the pH value to 7.2, adding a mixed cross-linking agent, uniformly stirring, grinding and filtering to obtain the aqueous emulsion.

In the step (1), the polyurethane emulsion is organosilicon modified amphoteric waterborne polyurethane emulsion. The modified fullerene is fullerene with the surface modified with dimercapto.

The preparation method of the organic silicon modified amphoteric waterborne polyurethane emulsion refers to the Chinese invention patent CN104292414A example 1. The preparation method of the fullerene with the surface modified with dimercapto refers to the embodiment 1 of the Chinese patent CN 111808444A.

In the step (2), the soft monomer is a mixture of n-butyl acrylate, isooctyl acrylate and 2-ethylhexyl methacrylate with a molar ratio of 4:1: 1.

In the step (2), the hard monomer is a mixture of methyl methacrylate and styrene in a mass ratio of 3: 1.

In the step (3), the initiator is ammonium persulfate.

In the step (5), the mixed crosslinking agent is a mixture of adipic acid dihydrazide, N-methylolacrylamide and itaconic acid. In the mixed crosslinking agent, the weight ratio of adipic acid dihydrazide, N-hydroxymethyl acrylamide and itaconic acid is 100: 7: 2.

the polypropylene-polyurethane weather-resistant paint comprises the following components in parts by weight: 35 parts of polyurethane emulsion, 0.2 part of modified fullerene, 25 parts of soft monomer, 5 parts of hard monomer, 0.3 part of initiator, 3 parts of mixed cross-linking agent and 45 parts of deionized water.

Comparative example 1

The organosilicon modified amphoteric waterborne polyurethane emulsion in the embodiment 1 is replaced by American Dow Bai Shimo pure acrylic emulsion PRIML ™ SF-508, and the rest proportion and the preparation method are not changed.

Comparative example 2

The fullerene with the surface modified by dimercapto in the example 1 is replaced by the unmodified fullerene, and the rest of the proportion and the preparation method are unchanged.

Comparative example 3

The fullerene with the surface modified by dimercapto in the example 1 is replaced by the fullerene with the surface modified (the preparation method refers to the embodiment 1 of the Chinese patent invention CN 103965570A), and the rest proportion and the preparation method are not changed.

Comparative example 4

The fullerene with the surface modified by dimercapto in the example 1 is replaced by the mercapto-modified graphene oxide (the preparation method is referred to the chinese patent CN109944065A example 1), and the rest proportion and the preparation method are not changed.

Comparative example 5

The mixed crosslinking agent in the example 1 is replaced by adipic acid dihydrazide, and the rest of the proportion and the preparation method are unchanged.

The polypropylene-based polyurethane weather-resistant paint is detected by the following specific method: the polypropylene-based polyurethane weather-resistant paint prepared in each example and comparative example is smeared on six surfaces of a 200mm × 200mm × 5mm concrete hexagonal block (tested to have the test strength of 49.5-49.9 MPa and the average value of 49.7 MPa according to GB/T50081-2002 standard of mechanical property test method of common concrete after being cured for 28 days, the test strength is 5 + -0.2 mm), the test block is soaked in seawater (real seawater taken from Zhoushan of Zhejiang), fresh seawater is replaced once every 15 days, and the test block is taken out after 60 days. And respectively measuring the compressive strength, the water loss rate, the water absorption rate, the wear resistance and the chloride ion diffusion coefficient of the test block. Wherein, the water loss rate and the water absorption rate are determined according to ASTM C1585-2013 Standard test method for measuring concrete Water absorption; the wear resistance is measured according to JTGE30-2005 method for testing wear resistance of cement concrete; the chlorine ion penetration resistance test method is carried out according to 2.2.5 chlorine ion penetration resistance tests in Shuqing Shuichi's thesis on the influence of nano silicon dioxide on the performance of cement-based materials and the research on action mechanism. The test results are shown in Table 1. As a control example, a hexagonal concrete block was used which was subjected to a coating treatment with a weather-resistant lacquer of dipropylene polyurethane.

Table 1: comparing the test result of the concrete hexagonal block;

	compressive strength (MPa)	The water loss rate%	Water absorption%	Amount of wear (kg/m)2）	Diffusion coefficient of chloride ion (10)-12m2/s）
						Example 1	46.7	0.28	0.88	0.78	7.6
Example 2	46.5	0.29	0.91	0.81	7.8
						Example 3	46.4	0.29	0.92	0.83	7.9
Comparative example 1	38.3	0.36	1.15	0.95	10.1
						Comparative example 2	32.2	0.41	1.29	1.05	11.5
Comparative example 3	39.1	0.35	1.07	0.92	9.4
						Comparative example 4	37.7	0.37	1.19	0.94	9.9
Comparative example 5	42.4	0.32	1.02	0.87	8.6
						Comparative example	17.1	0.87	2.86	1.47	16.4

The test data show that the polypropylene-based polyurethane weather-resistant paint has obvious effects of improving the compressive strength, the water loss rate, the water absorption rate, the wear resistance and the chloride ion diffusion coefficient after concrete aging (seawater soaking) due to the addition of the organic silicon modified amphoteric waterborne polyurethane emulsion and the fullerene with the surface modified with dimercapto.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.