Two-component epoxy dip-coating paint for strong-permeation boiling-resistant water-based textile paper tube and preparation method of two-component epoxy dip-coating paint

Abstract

The invention discloses a bi-component epoxy dip-coating paint for a strong-permeation boiling-resistant water-based textile paper tube and a preparation method of the bi-component epoxy dip-coating paint, and belongs to the technical field of water-based paints. The coating is composed of a component A and a component B, wherein the component A is a composite wetting penetrant composed of a self-emulsifying submicron waterborne epoxy dispersion, dioctyl sodium sulfosuccinate and an acetylene glycol surfactant; and the component B is a quick-drying water-soluble modified polyamine curing agent added with a reactive curing accelerator. Through the cooperation of the small-particle-size epoxy dispersoid and the composite wetting penetrant, the technical problems that a traditional water-based paint is poor in permeability to paper tube fibers and weak in adhesive force are solved; meanwhile, through the synergistic effect of the quick-drying curing agent and the accelerant, the drying time is shortened. The coating has the characteristics of low VOC (volatile organic compound) content, environmental protection, safety, high permeability to paper tube base materials, high drying speed and excellent adhesive force, and a compact paint film formed after curing has saturated water vapor cooking resistance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of water-based paint, and particularly relates to a dip-coating paint specially used for paper tubes in the textile industry, in particular, a two-component water-based epoxy paint with excellent permeability, rapid drying capacity and saturated water vapor cooking resistance and a preparation method thereof. BACKGROUND

[0002] Chemical fiber textile paper tubes are widely used in the textile industry, mainly used for winding various types of yarns such as cotton yarn, chemical fiber yarn and wool sand, so as to facilitate the storage, transportation and subsequent processing of the yarns. The environment in the textile factory is relatively humid, and in the process of textile production, the paper tube will frequently contact and rub with the textile equipment and yarns. Therefore, the paint for the paper tube must have good water resistance and wear resistance. In addition, the paper tube may be deformed to a certain extent during the yarn winding process, and the paint should also have good flexibility and firm adhesion. Since the yarn is expensive, in order to avoid the economic loss caused by the yarn scrap due to the deformation of the paper tube, the paper tube processing enterprises usually adopt the method of saturated water vapor cooking for the finished paper tube to detect the water resistance of the paint film and control the tube breaking rate, so as to determine whether the paper tube will be deformed and swollen after winding the yarn. Wax / paraffin impregnation is a relatively traditional and basic treatment method, and the main purpose is to improve the water resistance and moisture resistance of the paper tube, but the wear resistance, hardness and temperature resistance are poor, which cannot meet the requirements of high-speed winding of high-end textiles (such as chemical fiber filaments). Coating treatment is one of the most common ways for surface treatment of industrial yarn paper tubes. By coating one or more layers of special paint on the surface of the paper tube, the performance of the paper tube can be improved.

[0003] At present, there are mainly two types of paper tube paints on the market: 1. Solvent-based paint: mainly solvent-based alkyd or epoxy varnish. Although this type of paint has fast drying speed and good permeability to paper tubes, it contains a large amount of organic volatile matter (VOC) such as benzene and ester, and the VOC content is usually as high as 500 g / L or more. It has a strong odor, is flammable and explosive, and causes serious harm to the health of production workers and the environment. With the increasingly strict national environmental protection regulations, its application is increasingly limited; 2. Traditional water-based paint: mainly single-component acrylic emulsion paint. Although this type of paint is environmentally friendly, due to its film-forming mechanism of physical accumulation after water evaporation, the crosslinking density is low, and the water resistance and cooking resistance are poor, which is difficult to meet the performance requirements of textile paper tubes. Although the traditional two-component water-based epoxy paint has improved chemical resistance, it still has many problems: first, the surface tension of water is large, which leads to poor wetting and permeability of the paint to the fibers of the paper tube, and poor adhesion; second, water evaporation is slow, which leads to long drying period, and the problem of paper tube sticking (sticking tube) is prone to occur during dip-coating construction, which affects the production efficiency; finally, the activation period is usually short, which is not convenient for on-site construction.

[0004] Therefore, developing a water-based textile paper tube coating which meets the environmental protection requirements and is equivalent or even superior to solvent-based coating in performance, especially having strong penetration, fast drying and excellent resistance to cooking, is a technical problem to be solved in the field. SUMMARY

[0005] The present application aims to overcome the deficiencies of the prior art, and provides a strong penetration and cooking resistant type water-based textile paper tube two-component epoxy dip coating and a preparation method thereof. The present application solves the technical problems of poor fiber penetration and weak adhesion of traditional water-based coating on paper tube through the action of small particle size epoxy dispersion and composite wetting penetrant; at the same time, the drying time is shortened through the cooperation of fast drying curing agent and accelerator. The prepared coating has the characteristics of low VOC content, environmental protection and safety, strong penetration on paper tube substrate, fast drying speed and excellent adhesion, and the dense paint film formed after curing has the performance of resistance to saturated steam cooking, which can effectively prevent the deformation of paper tube in use environment.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: A strong penetration and cooking resistant type water-based textile paper tube two-component epoxy dip coating, which is composed of A component and B component, and A component and B component are mixed in a mass ratio of 5:1~10:1 before use; The A component is made of the following raw materials in mass fraction: Self-emulsifying sub-micron water-based epoxy dispersion: 100 parts; Film forming aid: 3-8 parts; Composite wetting penetrant: 0.5-2 parts; Leveling agent: 0.2-1 part; Defoaming agent: 0.1-0.5 parts; Deionized water: 10-30 parts; Thickening agent: 0.1-0.5 parts; The B component is made of the following raw materials in mass fraction: Fast-drying water-soluble modified polyamine curing agent: 100 parts; Reaction type curing accelerator: 2-10 parts; Fast-drying cosolvent: 10-20 parts; Deionized water: 10-30 parts; Further, the self-emulsifying sub-micron water-based epoxy dispersion is a water-based dispersion of bisphenol A type epoxy resin, with a solid content of 50-60%, an average particle size of less than 500 nanometers, and an epoxy equivalent weight of 450-550 g / eq. Further preferably, it is Hansen EPI-REZ™ 5003-W-55, Hansen EPI-REZ™ 3520-WY-55, Hensyl Araldite® PZ 3961-1.

[0007] Further, the composite wetting penetrant is compounded by sulfobutane diacid dioctyl sodium salt and acetylene diol surfactant at a mass ratio of 1:1 to 1:3. The acetylene diol surfactant is 2,4,7,9-tetramethyl-5-decyn-4,7-diol (TMDD).

[0008] Further, the film forming aid is one of or a mixture of dipropylene glycol butyl ether or propylene glycol phenyl ether, dodecanol ester; Further, the leveling agent is BYK-348 or BYK-3455 of BIK Chemical; Further, the defoaming agent is silicone; Further, the thickening agent is preferably a non-ionic associated polyurethane thickening agent HEUR.

[0009] Further, the quick-drying water-soluble modified polyamine curing agent is a water-soluble modified aliphatic amine or modified alicyclic amine curing agent with a solid content of 45-55%, and the active hydrogen equivalent weight is 80-150 g / eq. Further, Kadelite LITE 3040, Kadelite NX-8101 or Hensma 3986 XW 55 are preferred.

[0010] Further, the reactive curing accelerator is a tertiary amine compound containing active hydrogen, preferably 2,4,6-tris(dimethylaminomethyl)phenol.

[0011] Further, the quick-drying cosolvent is one or a mixture of at least two of ethanol, isopropyl alcohol or n-butanol.

[0012] The present application also provides a preparation method of the above-mentioned coating, comprising the following steps: (1) Preparation of component A: add a metered amount of self-emulsifying submicron water-based epoxy dispersion to a stirred tank, and under stirring, add film forming aid, composite wetting penetrant, leveling agent, defoaming agent in turn, and stir at medium speed for 15-30 minutes to make them uniformly dispersed; then slowly add deionized water, and finally add thickening agent to adjust the construction viscosity, adjust the coating viscosity to 40±5 seconds under the test conditions of Cup-4 (25℃), and filter the material after uniform stirring, to obtain component A.

[0013] (2) Preparation of component B: add a metered amount of quick-drying water-soluble modified polyamine curing agent to a clean stirred tank, start stirring, and add reactive curing accelerator, quick-drying cosolvent and deionized water in turn, stir for 25-35 minutes, and pay attention to control the system temperature not to exceed 40℃, until the system is clear and transparent, and filter the material, to obtain component B.

[0014] Compared with the prior art, the present application has the following beneficial effects: (1) The epoxy emulsion with an average particle size less than 500 nanometers is adopted in the present application, and is matched with a composite wetting penetrant; the dioctyl sodium sulfosuccinate in the composite wetting penetrant can quickly reduce the surface tension of the coating, and the acetylene glycol surfactant as a low-foam wetting agent can further help the penetration, so that the coating can easily and quickly penetrate into the paper tube fiber, the paint film adhesion is improved, and the paint film peeling is effectively prevented. And through the crosslinking network formed by the polyamine curing agent and the epoxy resin, the reaction type accelerator is introduced to further promote the crosslinking, so that the paint film is dense. After being cooked in saturated steam for 2.0 hours, the paint film is not foamed and peeled, and the paper tube is not damaged and deformed.

[0015] (2) The present application adopts the joint action of the fast-drying curing agent and the reaction type accelerator, and combines with the fast-drying cosolvent, so that the drying time of the paint film is shortened, the surface drying time is ≤1 hour, and the problems of low construction efficiency and easy pipe sticking of the water-based coating are solved.

[0016] (3) The present application uses water as a dispersion medium, the cosolvent used is a low-toxicity alcohol, the amount used is small, and the VOC content is extremely low, so that the working environment is improved compared with the traditional solvent-based coating, and the environment is safe. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below. The self-emulsifying sub-micron water-based epoxy dispersion selects Hansen EPI-REZ™ 3520-WY-55; the leveling agent selects BYK-348 of BYK Chemical; the fast-drying water-soluble modified polyamine curing agent selects Aradur® 3986 XW 55 of Huntsman; and the polyurethane thickening agent is selected from a non-ionic associated polyurethane thickening agent HEUR, and the acetylene glycol surfactant is 2,4,7,9-tetramethyl-5-decyn-4,7-diol (TMDD). Example 1

[0018] A strong penetration and steaming resistant type water-based two-component epoxy dip coating for textile paper tube.

[0019] (1) Component A Self-emulsifying sub-micron water-based epoxy dispersion: 100 kg; Propylene glycol phenyl ether: 5 kg; Composite wetting penetrant: dioctyl sodium sulfosuccinate and acetylene glycol surfactant (TMDD) are compounded at a ratio of 1:2: 1.5 kg; Leveling agent: 0.5 kg; Silicone defoamer: 0.3 kg; Deionized water: 20 kg; Polyurethane thickening agent: 0.3 kg Self-emulsifying sub-micron waterborne epoxy dispersion, film forming aid, composite wetting penetrant, leveling agent and defoaming agent were added into a 1000L stirred tank, and stirring was started at 300 rpm for 20 minutes to disperse them evenly. Then 20 kg of deionized water was slowly added, and stirring was continued for 10 minutes. Finally, 0.3 kg of polyurethane thickening agent was added under low-speed stirring, and the viscosity was adjusted to 40 seconds at 4 cups (25°C). After stirring evenly, the material was filtered out to obtain component A.

[0020] (2) Preparation of component B: Fast-drying water-soluble modified aliphatic amine curing agent: 100 kg 2,4,6-tris(dimethylaminomethyl)phenol: 6 kg Fast-drying co-solvent isopropyl alcohol: 15 kg Deionized water: 25 kg In a 500L stirred tank, the above materials were added, and stirring was started at 400 rpm for 30 minutes to control the temperature not to exceed 40°C until the system was completely homogeneous and clear. After filtration, component B was obtained.

[0021] Before construction, component A and component B were mixed in a mass ratio of 8:1. Example 2:

[0022] A strong penetration and autoclave-resistant two-component waterborne epoxy dip coating for textile paper tubes.

[0023] (1) Component A Self-emulsifying sub-micron waterborne epoxy dispersion: 100 kg; Propylene glycol phenyl ether: 7 kg; Composite wetting penetrant: sulfobutane disodium salt and acetylene diol surfactant (TMDD) compounded at a ratio of 1:1: 1.0 kg; Leveling agent: 0.8 kg; Silicone defoamer: 0.4 kg; Deionized water: 15 kg; Polyurethane thickening agent: 0.4 kg; Self-emulsifying sub-micron waterborne epoxy dispersion, film forming aid, composite wetting penetrant, leveling agent and defoaming agent were added into a 1000L stirred tank, and stirring was started at 300 rpm for 25 minutes to disperse them evenly. Then 15 kg of deionized water was slowly added, and stirring was continued for 10 minutes. Finally, 0.4 kg of polyurethane thickening agent was added under low-speed stirring, and the viscosity was adjusted to 45 seconds at 4 cups (25°C). After stirring evenly, the material was filtered out to obtain component A.

[0024] (2) Preparation of component B: Fast-drying water-soluble modified aliphatic amine curing agent: 100 kg 2,4,6-tris(dimethylaminomethyl)phenol: 9 kg Fast drying co-solvent n-butanol: 10 kg Deionized water: 15 kg In a 500 L stirred tank, the above materials were added, stirring was started, and the system was stirred at 400 rpm for 35 minutes, with the temperature controlled to not exceed 40°C, until the system was completely homogeneous and clear. After filtration, component B was obtained.

[0025] Before application, component A and component B were mixed at a mass ratio of 10:1.

[0026] Comparative Example 1: Comparative Example 1 differs from Example 1 in that the self-emulsifying sub-micron waterborne epoxy dispersion in component A was replaced with an equal amount of conventional waterborne epoxy emulsion (Nanya: NPEW-261W55), and the other components and preparation methods were the same as in Example 1.

[0027] Comparative Example 2: Comparative Example 2 differs from Example 1 in that the composite wetting penetrant in component A was replaced with an equal amount of dioctyl sodium sulfosuccinate, and the other components and preparation methods were the same as in Example 1.

[0028] Comparative Example 3: Comparative Example 3 differs from Example 1 in that the ethynediol surfactant (TMDD) in the composite wetting penetrant in component A was replaced with an equal amount of fatty alcohol polyoxyethylene ether AEO, and the other components and preparation methods were the same as in Example 1.

[0029] Comparative Example 4: Comparative Example 4 differs from Example 1 in that no reactive curing accelerator was added in component B, and the other components and preparation methods were the same as in Example 1.

[0030] The components A and components B prepared in each of the above examples and comparative examples were mixed at the mass ratio specified in the examples, and an electric mixer was used to stir the system for 3-5 minutes until it was homogeneous. The pot life of the mixed paint was tested in an environment with a temperature of 25°C and a relative humidity of 60% RH. The paint was applied uniformly using the dip coating method. The paint film was cured under standard curing conditions: a temperature of 25±2°C and a relative humidity of 65±5% RH. The paint film performance tests were all conducted after 7 days of curing under standard curing conditions to ensure that the paint film was completely cured.

[0031] Table 1: Test item Test standard Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Coat film appearance Visual observation Smooth and defect-free Smooth and high gloss Rough and grainy Few pinholes Many pinholes and shrinkage Smooth and defect-free Dry to touch time (h, 25℃) GB / T 1728-1979 ≤ 1.0 ≤ 1.2 ≤ 1.5 ≤ 1.0 ≤ 1.0 >10.0 Curing time (80℃ baking, h) GB / T 1728-1979 ≤ 0.5 ≤ 0.5 ≤ 0.6 ≤ 0.5 ≤ 0.5 >3.0 Adhesion (grade) GB / T 9286 1 1 4 2 3 1 Hardness (pencil method) GB / T 6739 H 2H B H F <HB (fuzzy) Gloss (60°) GB / T 9754 85 90 60 82 65 80 Flexibility (mm) GB / T 1731 1 2 1 1 1 1 Resistance to cooking (100℃ saturated steam, 2.0h) Enterprise standard No blistering and peeling No blistering and peeling Severe blistering and peeling Slight hazing and blistering Obvious blistering and hazing Coat film softening and whitening Resistance to abrasion (mass loss, g) Taber abrasion test (under 500g load, CS-10 abrasive wheel, 1000 rotations) 12 10 >50 (coat film peeling) 20 35 25 The coatings of Example 1 and Example 2 can be quickly dried, have a 1st grade adhesion, mechanical properties: H hardness, 1mm flexibility, and excellent resistance to cooking.

[0032] Comparative Example 1 replaces the sub-micron epoxy with a conventional micron epoxy, the micron particles are difficult to penetrate the paper tube fibers smoothly, only forming a surface adhesion poor, loose structure of the paint film. The film can not resist the erosion of water vapor, leading to the interface is destroyed and failure. Comparative Example 2 removes the ethynediol surfactant in the composite wetting agent, resulting in a decrease in adhesion, pinholes in the film, and poor resistance to cooking. Comparative Example 3 replaces TMDD with a conventional fatty alcohol polyoxyethylene ether, resulting in a large amount of foam, film defects are serious, adhesion is further deteriorated, and resistance to cooking is also significantly deteriorated. It proves the synergistic effect between the combination of sodium dioctyl sulfosuccinate and TMDD. The sulfosuccinate quickly wets, and the TMDD further penetrates to ensure that the film is dense and defect-free. If the TMDD penetration is lacking and the density is insufficient. Comparative Example 4 removes the accelerator DMP-30, resulting in a significant increase in drying time, which cannot meet the efficiency requirements of industrial production. Within the conventional detection period, the film is soft and has poor resistance to cooking, appearing soft and white, which is because the crosslinking reaction is not complete and the film does not form a dense network structure.

[0033] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A strong penetrating and boiling-resistant water-based two-component epoxy dipping coating for textile paper tubes, characterized in that: It is composed of component A and component B. Before use, mix component A and component B in a mass ratio of 5:1~10:1; The component A is made of the following raw materials in parts by mass: Self-emulsifying submicron waterborne epoxy dispersion: 100 parts; Film-forming aid: 3-8 parts; Composite wetting and penetrating agent: 0.5-2 parts; Leveling agent: 0.2-1 part; Defoaming agent: 0.1-0.5 parts; Deionized water: 10-30 parts; Thickener: 0.1-0.5 parts; The B component is made of the following raw materials in parts by mass: Water-soluble modified polyamine curing agent: 100 parts; Curing accelerator: 2-10 parts; Quick-drying cosolvent: 10-20 parts; Deionized water: 10-30 parts; The composite wetting and penetrating agent is prepared by compounding dioctyl sodium sulfosuccinate and acetylene glycol surfactant in a mass ratio of 1:1 to 1:

3.

2. The strong permeability and boiling-resistant water-based two-component epoxy impregnation coating for textile paper tubes according to claim 1, characterized in that: The self-emulsifying submicron water-based epoxy dispersion is a water-based dispersion of bisphenol A epoxy resin, has an average particle size of less than 500 nanometers, a solid content of 50-60%, and an epoxy equivalent weight of 450-550 g / eq.

3. The strong permeability and boiling-resistant water-based two-component epoxy dipping coating for textile paper tubes according to claim 1 is characterized in that: The acetylene glycol surfactant in the composite wetting and penetrating agent is 2,4,7,9-tetramethyl-5-decyne-4,7-diol.

4. The strong permeability and boiling-resistant water-based two-component epoxy impregnation coating for textile paper tubes according to claim 1, characterized in that: The water-soluble modified polyamine curing agent is a water-soluble modified fatty amine or modified alicyclic amine curing agent, and has a solid content of 45-55% and an active hydrogen equivalent of 80-150 g / eq.

5. The strong permeability and boiling-resistant water-based two-component epoxy dipping coating for textile paper tubes according to claim 1 is characterized in that: The curing accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

6. The strong permeability and boiling-resistant water-based two-component epoxy dipping coating for textile paper tubes according to claim 1 is characterized in that: The film-forming aid is one of dipropylene glycol butyl ether, propylene glycol phenyl ether or dodecyl alcohol ester, or a mixture of at least two thereof; and the thickener is a nonionic associative polyurethane thickener.

7. A method for preparing the strong permeability and boiling-resistant water-based two-component epoxy impregnation coating for textile paper tubes according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Preparation of component A: Add self-emulsifying submicron waterborne epoxy dispersion into a stirring kettle. While stirring, add film-forming aid, composite wetting and penetrating agent, leveling agent, and defoaming agent in sequence. Stir at medium speed for 15 to 30 minutes. Then add deionized water. Finally, add thickener to adjust the viscosity to 35 to 45 seconds for coating 4 cups at 25°C. Stir well and filter the material to obtain component A. (2) Preparation of component B: Add water-soluble modified polyamine curing agent into a stirring kettle, start stirring, add curing accelerator, quick-drying cosolvent and deionized water in sequence, and stir for 25 to 35 minutes under the condition of controlling the temperature not to exceed 40°C until the system becomes clear and transparent. Filter the material to obtain component B.