A VAE coating for imitating artificial PU and its preparation method

Abstract

The present invention relates to the technical field of coating compositions, and discloses a VAE coating for imitating artificial polyurethane (PU) and a preparation method thereof. The coating comprises the following ingredients by weight: 30-60 parts of vinyl acetate-ethylene copolymer emulsion; 20-40 parts of titanium dioxide; 5-20 parts of quartz powder; 5-20 parts of a plasticizer; 3-5 parts of a wetting agent; and 3-5 parts of a defoaming agent. The coating has strong adhesion, good elasticity, good flexibility, a soft feel, and anti-sticking properties. It is low in cost, non-toxic, odorless, easily degradable, pollution-free, safe, environmentally friendly, and harmless to the human body.

Description

Technical Field

[0001] The present invention relates to the technical field of coating compositions, and in particular to a VAE coating for imitating artificial PU and a preparation method thereof. Background Art

[0002] PU is the abbreviation of Polyurethane, and its Chinese name is polyurethane, which is abbreviated as polyurethane. Since different physical properties such as density, elasticity, and rigidity can be obtained by simply modifying the formula, it is currently widely used in interior and exterior wall insulation materials, refrigerator insulation materials, home decoration, high-end sporting goods, and artificial synthetic PU leather.

[0003] However, due to the high cost of synthetic PU leather, large-scale promotion in some soft packaging areas is somewhat difficult. In existing artificial PU leather-like coatings, the emulsion content of the coating as a base material is increased to increase the flexibility and feel of the coating film. However, adding too much emulsion will cause the coating to have a certain degree of tackiness. Tackiness refers to the phenomenon of adhesion of the paint film after drying due to the influence of certain temperature and humidity, resulting in an apparent stickiness. Once the coating film is tackified, it is easy to pick up dust, affecting the decorative effect of the coating film. The tackiness of the coating film is accompanied by softening of the coating film, which will reduce the hardness, wear resistance, and corrosion resistance of the coating film. The tackiness of the coating film can only be scraped off and recoated. Therefore, tackiness is a coating defect. To solve the problem of tackiness of the coating film, the common method is to reduce the emulsion content of the coating as a base material, thereby improving the coating film's anti-tackiness. However, this also presents a new problem. Due to the reduced emulsion content of the coating as a base material, the coating will easily fall off after spraying.

[0004] Therefore, how to prepare a coating that has both anti-sticking properties and is not prone to powdering is a technical problem that needs to be solved urgently in the existing technology. Summary of the Invention

[0005] The present invention aims to provide a VAE coating for imitating artificial PU and a preparation method thereof, so that the prepared coating has both anti-rebound properties and is not prone to powdering problems.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A VAE coating for imitating artificial PU, comprising the following components in parts by weight:

[0008]

[0009]

[0010] The principle and advantage of this solution are: the non-ionic wetting agent can make the filler dispersed evenly in the emulsion, so that the coating has excellent anti-sticking properties.

[0011] In practical applications, emulsions play a crucial role in the mechanical and thermal properties of coatings. During the film-forming process, emulsion particles coalesce and bind pigments and fillers together, forming a continuous coating. The addition of emulsion improves the coating's mechanical properties, such as adhesion, elongation at break, and flexibility; however, increasing the emulsion content can also reduce the coating's anti-sticking properties. Therefore, to circumvent this problem, the prior art typically reduces the emulsion content, but this approach suffers from the drawback of easy powder shedding after the coating film is formed. By screening a variety of different pigments, fillers, and related additives without reducing the emulsion content, the present invention unexpectedly discovered a synergistic effect between wetting agents and quartz powder. Wetting agents reduce the surface tension of the coating, enabling it to better wet the substrate and are generally used to improve the coating's adhesion to the substrate. Quartz powder, a filler composed of silica, is commonly used to fill coatings, reducing coating costs and improving the coating's wear resistance, heat resistance, and chemical resistance. Furthermore, during their research, the inventors unexpectedly discovered that compounding quartz powder and a wetting agent into a coating not only maintains its original effects but also effectively improves the coating's anti-sticking properties, overcoming the coating's powder shedding problem. The mechanism is as follows: the wetting agent reduces the latex's surface tension, allowing the quartz powder to be evenly dispersed throughout the system. After the film dries, it fully utilizes the latex's adhesive strength and the hardness of the quartz powder distributed on the latex surface.

[0012] In addition to the above properties, the coating of the present invention also has the advantages of strong adhesion, high strength, good flexibility, soft feel, low cost, non-toxic, odorless, easy to degrade, pollution-free, safe and environmentally friendly, and harmless to the human body.

[0013] Preferably, as an improvement, the ethylene content in the vinyl acetate-ethylene copolymer emulsion is ≥25%.

[0014] Beneficial Effects: When the ethylene content falls within this range, the coating exhibits a lower minimum film-forming temperature (MFFT) and exhibits good elasticity and flexibility. If the ethylene content falls below this range, the coating's glass transition temperature (GFT) increases, raising the MFFT. If the GFT rises above room temperature, the coating will not form a film. In this case, the addition of a film-forming aid can be used to maintain low-temperature moldability. However, excessive amounts of film-forming aid can affect the coating's water and alcohol resistance and increase the actual drying rate. Furthermore, an elevated GFT can reduce the coating's elasticity and flexibility.

[0015] Preferably, as an improvement, the particle size of the titanium dioxide is 600-1250 mesh.

[0016] Beneficial Effects: Within this range, titanium dioxide particle size exhibits excellent dispersibility, resulting in a more even distribution of titanium dioxide in the emulsion, improved compatibility with the emulsion, and enhanced coating strength and adhesion. If the titanium dioxide particle size is too large, it will not be easily evenly distributed in the emulsion; if the particle size is too small, the coating strength and adhesion will be reduced, shortening the life of the paint film.

[0017] Preferably, as an improvement, the particle size of the quartz powder is 600-1250 mesh.

[0018] Benefits: Quartz powder within this particle size range allows for uniform dispersion throughout the coating during film formation, significantly improving film strength. If the particle size is too large, it will not distribute evenly throughout the film; if the particle size is too small, the film strength will be reduced. The synergistic effect of quartz powder and wetting agents can improve the film's anti-sticking properties.

[0019] Preferably, as an improvement, the plasticizer is one of MADE and TXIB.

[0020] Beneficial effects: MADE and TXIB are both non-toxic and environmentally friendly plasticizers that can significantly improve the strength and elasticity of the coating, and improve its flexibility and adhesion.

[0021] Omode MADE (DuPont calls it DBE) is a mixture of dibasic acid esters, also known as divalent acid esters. It is a low-toxic, low-odor, biodegradable, and environmentally friendly high-boiling-point solvent. The Omode MADE product line includes dimethyl succinate, dimethyl glutarate, dimethyl adipate, and mixtures thereof in varying proportions. The concentrations of each component in the mixture are: 25-60% dimethyl glutarate, 20-50% dimethyl adipate, and 10-30% dimethyl succinate.

[0022] TXIB, chemically known as 2,2,4-trimethylpentanediol diisobutyrate, is a viscosity reducer with plasticizing properties and low volatility, which can impart good cold and water resistance to coatings.

[0023] Preferably, as an improvement, the wetting agent is a nonionic wetting agent.

[0024] Beneficial Effects: Nonionic wetting agents can effectively reduce the surface tension of coatings, improve hydrophilicity, quickly wet the substrate, and enhance the adhesion of the coating. Nonionic wetting agents work synergistically with fillers to improve the coating's anti-sticking properties.

[0025] As a type of wetting agent, nonionic wetting agents include polyoxyethylene alkylphenol ethers, polyoxyethylene fatty alcohol ethers, polyoxyethylene polyoxypropylene block copolymers, etc., which are well known to those skilled in the art.

[0026] Preferably, as an improvement, the defoaming agent is one or both of a block polyether defoaming agent and an organosiloxane defoaming agent.

[0027] Beneficial effects: Block polyether defoamers and organosiloxane defoamers have both good defoaming and antifoaming effects, good stability, non-toxicity and environmental protection.

[0028] On the other hand, the present invention also provides a method for preparing a VAE coating for imitating artificial PU, comprising the following steps: mixing vinyl acetate-ethylene copolymer emulsion, titanium dioxide, quartz powder, plasticizer, wetting agent and defoamer, stirring evenly and allowing to stand.

[0029] Beneficial effects: Through mechanical stirring, the components in the coating can be evenly mixed, so that the formed coating film is more uniform, smoother and has a fuller color; and the preparation method is simple, which is conducive to industrial production.

[0030] Preferably, as an improvement, the stirring speed is 600-1800 rpm, and the standing time is 60-90 minutes.

[0031] Beneficial Effects: Within this stirring speed range, the paint disperses more evenly. A stirring speed too low can lead to uneven dispersion of the emulsion's components, while a stirring speed too high can cause the emulsion to break. Allowing the paint to sit for a period of time allows bubbles to fully escape, allowing the various components in the paint to dissolve better and mix more evenly.

[0032] In another aspect, the present invention provides a use of a VAE coating for imitating artificial PU in the preparation of imitating artificial PU, artificial fibers, and as a binder for cotton cloth.

[0033] Beneficial effects: The coating of the present application can be used to manufacture imitation artificial PU, artificial fibers and for bonding cotton cloth. DETAILED DESCRIPTION

[0034] The following is further described in detail through specific implementation methods:

[0035] VAE emulsion CW40-602 was purchased from Chongqing Chuanwei Chemical Co., Ltd. of Sinopec Group; ST-83 was purchased from Solvay; MP200 was purchased from Momentive, and Omode MADE was purchased from Jiangsu Omode Paint Co., Ltd.

[0036] Example 1 Preparation of artificial VAE coating

[0037] The composition of artificial VAE coating is:

[0038] VAE emulsion: 300 g VAE emulsion CW40-602 (ethylene content 25%);

[0039] Titanium dioxide: 400g, particle size 800 mesh;

[0040] Quartz powder: 200g, particle size 800 mesh;

[0041] Plasticizer: 100g, the plasticizer in this embodiment is MADE;

[0042] Wetting agent: 50 g, the wetting agent in this embodiment is ST-83;

[0043] Defoaming agent: 50 g. The defoaming agent in this embodiment is MP200.

[0044] The preparation method of the above-mentioned artificial VAE coating is as follows:

[0045] The vinyl acetate-ethylene copolymer emulsion, titanium dioxide, quartz powder, Omode MADE, ST-83 and MP200 were mixed evenly; then stirred and dispersed evenly at a speed of 900 rpm and allowed to stand for 90 minutes.

[0046] Example 2 Preparation of artificial VAE coating

[0047] The composition of artificial VAE coating is:

[0048] VAE emulsion: 300 g VAE emulsion CW40-602 (ethylene content 25%);

[0049] Titanium dioxide: 300g, particle size 800 mesh;

[0050] Quartz powder: 200g, particle size 800 mesh;

[0051] Plasticizer: 150g TXIB;

[0052] Wetting agent: 30g ST-83;

[0053] Defoaming agent: 30g MP200.

[0054] The preparation method of the coating is:

[0055] The vinyl acetate-ethylene copolymer emulsion, titanium dioxide, quartz powder, TXIB, ST-83 and MP200 were mixed evenly; then stirred and dispersed evenly at a speed of 600 rpm, and allowed to stand for 60 minutes.

[0056] Example 3 Preparation of artificial VAE coating

[0057] The composition of artificial VAE coating is:

[0058] VAE emulsion: 400 g VAE emulsion CW40-602 (ethylene content 30%);

[0059] Titanium dioxide: 400g particle size 800 mesh;

[0060] Quartz powder: 100g particle size 800 mesh;

[0061] Plasticizer: 200g Omode MADE;

[0062] Wetting agent: 30g ST-83;

[0063] Defoaming agent: 20g MP200.

[0064] The preparation method of the coating is:

[0065] The vinyl acetate-ethylene copolymer emulsion, titanium dioxide, quartz powder, high boiling point plasticizer, wetting agent and defoaming agent were mixed evenly; then stirred and dispersed evenly at a speed of 1800 rpm and allowed to stand for 90 minutes.

[0066] Example 4 Preparation of artificial VAE coating

[0067] The composition of artificial VAE coating is:

[0068] VAE emulsion: 500 g VAE emulsion CW40-602 (ethylene content 25%);

[0069] Titanium dioxide: 200g, particle size 800 mesh;

[0070] Quartz powder: 50g, particle size 800 mesh;

[0071] High boiling point plasticizer: 150g TXIB;

[0072] Wetting agent: 30g ST-83;

[0073] Defoaming agent: 20g MP200.

[0074] The preparation method of the coating is:

[0075] The vinyl acetate-ethylene copolymer emulsion, titanium dioxide, quartz powder, high boiling point plasticizer, wetting agent and defoaming agent were mixed evenly; then stirred and dispersed evenly at a speed of 1200 rpm, and allowed to stand for 80 minutes.

[0076] Example 5 Preparation of artificial VAE coating

[0077] The composition of artificial VAE coating is:

[0078] VAE emulsion: 600 g VAE emulsion CW40-602 (ethylene content 25%);

[0079] Titanium dioxide: 200g, particle size 800 mesh;

[0080] Quartz powder: 100g, particle size 800 mesh;

[0081] High boiling point plasticizer: 50g TXIB;

[0082] Wetting agent: 30g ST-83;

[0083] Defoaming agent: 20g MP200.

[0084] The preparation method of the coating is:

[0085] The vinyl acetate-ethylene copolymer emulsion, titanium dioxide, quartz powder, high boiling point plasticizer, wetting agent and defoaming agent were mixed evenly; then stirred and dispersed evenly at a speed of 1000 rpm and allowed to stand for 75 minutes.

[0086] Comparative Example 1

[0087] The difference between this comparative example and Example 1 is that no quartz powder is added.

[0088] Comparative Example 2

[0089] The difference between this comparative example and Example 1 is that ST-83 is not added.

[0090] Comparative Example 3

[0091] The difference between this comparative example and Example 1 is that quartz powder and ST-83 are not added.

[0092] Application performance testing

[0093] The coatings prepared in Examples 1-5 and Comparative Examples 1-12 were used to produce imitation PU, and then dried at 110°C for 5 minutes and then maintained at room temperature for 24 hours. Part of the material was removed and made into 2 cm wide * 10 cm long strip adhesive materials. Each example was repeated 10 times, and the peel tensile strength of the imitation PU materials was tested using a C43 microcomputer-controlled universal testing machine produced by MTS in the United States. The average value was used as the test result. Except for the different coatings, the above groups were subjected to the same conditions. The results are shown in Table 1.

[0094] Table 1 Performance test results

[0095]

[0096]

[0097] The results show that, as shown in Table 1, the coatings of Examples 1-5 damaged the substrate when used to produce imitation PU. This demonstrates the strong bonding strength of the adhesive of the present invention. Furthermore, the coatings of Examples 1-5 had no irritating odor, demonstrating the safety and environmental friendliness of the coatings of the present invention. Furthermore, the coatings prepared from Examples 1-5 exhibited virtually no tackiness, while Comparative Examples 1-3 exhibited varying degrees of tackiness.

[0098] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A VAE coating for imitating artificial PU, characterized in that: It is composed of the following raw materials in parts by mass: 30-60 parts of vinyl acetate-ethylene copolymer emulsion; the ethylene content of the vinyl acetate-ethylene copolymer emulsion is ≥25%; 20-40 parts of titanium dioxide; the particle size of the titanium dioxide is 800 mesh; 5-20 parts of quartz powder; the particle size of the quartz powder is 800 mesh; 5-20 parts of high boiling point solvent; 3-5 parts of wetting agent; the wetting agent is non-ionic wetting agent ST-83; 3-5 parts of defoaming agent.

2. The VAE coating for imitating artificial PU according to claim 1, characterized in that: The high boiling point solvent is one of MADE and TXIB.

3. The VAE coating for imitating artificial PU according to claim 1, characterized in that: The defoaming agent is one or both of a block polyether defoaming agent and an organosiloxane defoaming agent.

4. Use of the VAE coating for imitating artificial PU according to any one of claims 1 to 3 in the preparation of imitating artificial PU, artificial fibers and as a binder for cotton cloth.

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