Water-resistant and friction-resistant water-based art paint and preparation method thereof

Abstract

The invention discloses a water-resistant and friction-resistant water-based art paint and a preparation method thereof, and belongs to the technical field of water-based paints.The preparation method comprises the steps that hydroxyl-terminated polydimethylsiloxane is added into a polyisocyanate and polyether polyol reaction system, a polyurethane prepolymer is synthesized, epoxy resin is added for modification, neutralization is conducted through a neutralizer, and the water-resistant and friction-resistant water-based art paint is obtained. Emulsifying by using a mixed solution of ice water and water-based alkyd resin to obtain a modified polyurethane emulsion; and adding other auxiliaries such as natural pigments to obtain the water-resistant and friction-resistant water-based art paint. The water-based art paint provided by the invention has excellent wear resistance, strong adhesive force, gloss retention and good water resistance, does not use toxic and irritant solvents in the synthesis process, does not cause pollution to the environment, and has a wide application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of water-based coatings, and in particular relates to a water-resistant and friction-resistant water-based artistic paint and a preparation method thereof. Background Art

[0002] According to the solvent of the coating, it is generally divided into three categories: water-based, oil-based, and solvent-based. In recent years, with the continuous improvement of living standards, people's requirements for the environmental protection and performance of products are also increasing. Water-based coatings are gradually becoming a hot topic for relevant researchers because they use water as a dispersion medium, have low VOC content, low or no environmental pollution, and are easy to construct.

[0003] At present, the commonly used water-based art paints on the market mainly include watercolor paint, gouache paint, and acrylic paint. Watercolor paint is easy to fade when it encounters water after drying due to its own insufficient water fastness; gouache paint mostly appears in the form of water plus powder, and its dry and wet changes are very large, and its adhesion is not enough and it is easy to lose due to friction; although acrylic paint has the advantages of high gloss and strong adhesion, acrylic paint generally uses acrylate copolymers, which are generally chain-like linear structures, have poor water resistance, and are extremely sensitive to temperature, which can easily make the picture sticky due to high temperature. Therefore, it is necessary to develop a water-based art paint that improves water resistance and further improves friction resistance. Summary of the invention

[0004] One of the purposes of the present invention is to provide a water-resistant and abrasion-resistant water-based artistic paint to solve the problem that the water-resistant and abrasion-resistant water-based artistic paint in the background art is poor;

[0005] The second object of the present invention is to provide a method for preparing a water-resistant and abrasion-resistant water-based artistic paint.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] In a first aspect, a water-resistant and friction-resistant water-based artistic paint comprises the following components in parts by weight:

[0008] 70-90 parts of polyisocyanate, 60-90 parts of polyether polyol, 10-20 parts of terminal hydroxyl polydimethylsiloxane, 3-6 parts of epoxy resin, 10-20 parts of hydrophilic chain extender, 6-10 parts of small molecule chain extender, 0.1-1.5 parts of cross-linking agent, 0.6-1.2 parts of catalyst, 8-18 parts of neutralizer, 10-25 parts of natural pigment, 10-20 parts of water-based alkyd resin, 1-3 parts of leveling agent, 0.5-1 part of defoamer, 3-6 parts of thickener, 450-500 parts of ice-water mixture.

[0009] Furthermore, the molecular weight of the hydroxy-terminated polydimethylsiloxane is 1900-2200.

[0010] Furthermore, the epoxy resin is bisphenol A epoxy resin, preferably E-20.

[0011] Furthermore, the polyether polyol is selected from at least one of polypropylene glycol, polytetramethylene glycol, and polyethylene glycol, or a combination of two or more thereof.

[0012] Furthermore, the polyisocyanate is one or a combination of two or more of isophorone diisocyanate, dicyclohexylmethane diisocyanate, 1,6-hexyl diisocyanate, and tetramethylcyclohexylmethane diisocyanate.

[0013] Furthermore, the neutralizing agent is any one of triethylamine and diethanolamine.

[0014] Furthermore, the hydrophilic chain extender is one or a combination of two of dimethylolbutyric acid, dimethylolpropionic acid, and sodium aminosulfonate.

[0015] Furthermore, the small molecule chain extender is one or a combination of two of diethylene glycol, methyl propylene glycol, 1,4-butanediol, and neopentyl glycol.

[0016] Furthermore, the cross-linking agent is one of trimethylolpropane and trimethylolethane.

[0017] Furthermore, the catalyst is one of dibutyltin dilaurate and organic bismuth.

[0018] Furthermore, the natural pigment is one of monascus pigment, purple cabbage pigment, chrysanthemum yellow pigment, gardenia yellow pigment and gardenia green pigment.

[0019] Furthermore, the leveling agent is a silicone surfactant, preferably, German BYK349 ​​is selected; the defoaming agent is a polysiloxane copolymer defoaming agent; the thickener is a polyurethane associative thickener, preferably, Dow Chemical RM-2020 or Wanhua Chemical Carfil 9240 is selected.

[0020] Furthermore, the waterborne alkyd resin is Any one of 3AK0274B, Guangzhou Yuanda water-based alkyd resin-WX1442, and water-based alkyd resin-WX1440.

[0021] In a second aspect, a method for preparing a water-resistant and friction-resistant water-based artistic paint comprises the following steps:

[0022] S1. Mix polyether polyol, terminal hydroxyl polydimethylsiloxane and polyisocyanate evenly, and react at 85-95°C for 2-3h; add hydrophilic chain extender, small molecule chain extender, crosslinking agent and catalyst, and react at 60-75°C for 2-3h; add epoxy resin and react at 60°C for 0.5-1h; then cool to 35-45°C, add neutralizer for neutralization, and add ice-water mixture and water-based alkyd resin to the obtained mixture under high-speed shearing to emulsify it to obtain a modified polyurethane emulsion;

[0023] S2. Add natural pigment to the modified polyurethane emulsion and stir at 50°C for 1 to 1.5 hours; then add leveling agent, defoaming agent and thickener and stir to mix evenly to obtain water-resistant and friction-resistant water-based art paint.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention provides a water-based artistic paint with water-based polyurethane as a carrier and a preparation method thereof. The polyurethane prepolymer is synthesized by adding terminal hydroxyl polydimethylsiloxane to a polyisocyanate and polyether polyol reaction system, and then epoxy resin is added for modification. The polyurethane prepolymer is neutralized with a neutralizer and then emulsified with a mixed solution of ice water and a water-based alkyd resin to obtain a modified polyurethane emulsion. Then, other additives such as natural pigments are added to obtain the water-based artistic paint with water-based polyurethane as a carrier and friction resistance.

[0026] 2. The water-based artistic paint provided by the present invention has excellent wear resistance, strong adhesion, gloss retention and good water resistance. No toxic or irritating solvents are used in the synthesis process, and no pollution is caused to the environment. It has broad application prospects.

[0027] 3. In the present invention, terminal hydroxyl polydimethylsiloxane is added during the synthesis of the polyurethane linear chain segments, so that the silicon-oxygen bonds can be orderly distributed in the polyurethane chain segments, which not only improves the water resistance but also improves the heat resistance; the alkyd resin itself is easy to disperse the color paste, and the alkyd resin is combined with the epoxy resin and the polyurethane to form a three-dimensional network structure, which improves the film-forming performance. While improving the water resistance, it is not easy to wipe off, further enhancing the coating of the pigment, preventing the resin from stratifying, and improving its stability. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that the parameters such as the heating temperature rise rate and the cooling rate of the reaction equipment in the present invention are adjusted automatically according to the temperature set by the reaction equipment used and are not particularly limited as long as they meet the industry standards.

[0030] In the following examples and comparative examples, the waterborne alkyd resin is selected from Guangzhou Yuanda, waterborne alkyd resin-WX1440.

[0031] Example 1

[0032] A water-resistant and friction-resistant water-based artistic paint, comprising the following components in parts by weight:

[0033] Isophorone diisocyanate (polyisocyanate) 80g, polypropylene glycol (polyether polyol) 60g, terminal hydroxyl polydimethylsiloxane 15g, E-20 (epoxy resin) 5g, dimethylolpropionic acid (hydrophilic chain extender) 13g, 1,4-butanediol (small molecule chain extender) 6g, trimethylolpropane (cross-linking agent) 0.65g, dibutyltin dilaurate (catalyst) 0.9g, triethylamine (neutralizer) 14g, purple cabbage pigment (natural pigment) 20g, water-based alkyd resin-WX144013g, byk349 (leveling agent) 1g, polysiloxane copolymer defoamer 0.6g, RM-2020 (thickener) 5g, ice-water mixture 450g.

[0034] The method for preparing the water-resistant and friction-resistant water-based artistic paint comprises the following steps:

[0035] S1. 60g of polypropylene glycol, 80g of isophorone diisocyanate, and 15g of terminal hydroxyl polydimethylsiloxane were mixed uniformly, slowly heated to 90°C, and reacted at 90°C for 3h; cooled to 70°C, 13g of dimethylolpropionic acid and 6g of 1,4-butanediol, 0.65g of trimethylolpropane, and 0.9g of dibutyltin dilaurate were added, and reacted at 70°C for 3h; cooled to 60°C, 5g of E-20 was added, and reacted at 60°C for 0.5h; then cooled to 40°C, 14g of triethylamine was added and neutralized for 1min, and the obtained mixture was emulsified under high-speed shearing, and a mixed solution consisting of 450g of ice-water mixture and 13g of water-based alkyd resin was added to obtain a modified polyurethane emulsion;

[0036] S2. Add the prepared modified polyurethane emulsion to the reaction device, add 20g of purple cabbage pigment, adjust the reaction temperature to 50°C, and stir at a constant speed of 150rpm for 1.5h; then add 1g of byk349, 0.6g of polysiloxane copolymer defoamer, and 5g of RM-2020, stir and mix evenly to obtain a water-resistant and friction-resistant water-based art paint.

[0037] Example 2

[0038] A water-resistant and friction-resistant water-based artistic paint, comprising the following components in parts by weight:

[0039] Isophorone diisocyanate (polyisocyanate) 80g, polytetramethylene glycol (polyether polyol) 78g, terminal hydroxyl polydimethylsiloxane 10g, E-20 (epoxy resin) 5g, dimethylolpropionic acid (hydrophilic chain extender) 13g, 1,4-butanediol (small molecule chain extender) 6g, trimethylolpropane (cross-linking agent) 0.65g, dibutyltin dilaurate (catalyst) 0.9g, triethylamine (neutralizer) 14g, monascus pigment (natural pigment) 15g, water-based alkyd resin-WX144013g, byk349 (leveling agent) 1g, polysiloxane copolymer defoamer 0.6g, RM-2020 (thickener) 5g, ice-water mixture 450g.

[0040] The method for preparing the water-resistant and friction-resistant water-based artistic paint comprises the following steps:

[0041] S1. 78g of polytetrahydrofuran diol, 80g of isophorone diisocyanate, and 10g of terminal hydroxyl polydimethylsiloxane were mixed uniformly, slowly heated to 90°C, and reacted at 90°C for 3h; cooled to 70°C, 13g of dimethylol propionic acid and 6g of 1,4-butanediol, 0.65g of trimethylolpropane, and 0.9g of dibutyltin dilaurate were added, and reacted at 70°C for 3h; cooled to 60°C, 5g of E-20 was added, and reacted at 60°C for 0.5h; then cooled to 40°C, 14g of triethylamine was added and neutralized for 1min, and the obtained mixture was emulsified under high-speed shearing, and a mixed solution consisting of 450g of ice-water mixture and 13g of water-based alkyd resin was added to obtain a modified polyurethane emulsion;

[0042] S2. Add the prepared modified polyurethane emulsion to the reaction device, add 15g of red yeast rice pigment, adjust the reaction temperature to 50°C, and stir at a constant speed of 150rpm for 1.5h; then add 1g of byk349, 0.6g of polysiloxane copolymer defoamer, and 5g of RM-2020, stir and mix evenly to obtain a water-resistant and friction-resistant water-based art paint.

[0043] Example 3

[0044] A water-based artistic paint that is resistant to water and friction, comprising the following components in parts by weight

[0045] Isophorone diisocyanate (polyisocyanate) 75g, polytetramethylene glycol 40g, polypropylene glycol 40g (polyether polyol), terminal hydroxyl polydimethylsiloxane 10g, E-20 (epoxy resin) 5g, dimethylolpropionic acid (hydrophilic chain extender) 13g, 1,4-butanediol (small molecule chain extender) 6g, trimethylolpropane (cross-linking agent) 0.65g, dibutyltin dilaurate (catalyst) 0.9g, triethylamine (neutralizer) 14g, gardenia yellow pigment (natural pigment) 15g, water-based alkyd resin-WX144013g, byk349 (leveling agent) 1g, polysiloxane copolymer defoamer 0.6g, RM-2020 (thickener) 5g, ice-water mixture 450g.

[0046] The method for preparing the water-resistant and friction-resistant water-based artistic paint comprises the following steps:

[0047] S1. 40g of polytetrahydrofuran diol, 40g of polypropylene glycol, 75g of isophorone diisocyanate, and 10g of terminal hydroxyl polydimethylsiloxane were mixed uniformly, slowly heated to 90°C, and reacted at 90°C for 3h; cooled to 70°C, 13g of dimethylol propionic acid and 6g of 1,4-butanediol, 0.65g of trimethylolpropane, and 0.9g of dibutyltin dilaurate were added, and reacted at 70°C for 3h; cooled to 60°C, 5g of E-20 was added, and reacted at 60°C for 0.5h; then cooled to 40°C, 14g of triethylamine was added and neutralized for 1min, and the obtained mixture was emulsified under high-speed shearing, and a mixed solution consisting of 450g of ice-water mixture and 13g of water-based alkyd resin was added to obtain a modified polyurethane emulsion;

[0048] S2. Add the prepared modified polyurethane emulsion to the reaction device, add 15g of gardenia yellow pigment, adjust the reaction temperature to 50°C, and stir at a constant speed of 150rpm for 1.5h; then add 1g of byk349, 0.6g of polysiloxane copolymer defoamer, and 5g of RM-2020, stir and mix evenly to obtain a water-resistant and friction-resistant water-based art paint.

[0049] Comparative Example 1

[0050] A water-based art paint, which is different from Example 1 in that no hydroxyl-terminated polydimethylsiloxane is added to the formula;

[0051] The preparation method of the water-based artistic paint is consistent with that of Example 1.

[0052] Comparative Example 2

[0053] A water-based art paint, which is different from Example 1 in that the water-based alkyd resin-WX1440 is not added to the formula;

[0054] The preparation method of the water-based artistic paint is consistent with that of Example 1.

[0055] Comparative Example 3

[0056] A water-based art paint, which is different from Example 1 in that terminal hydroxyl polydimethylsiloxane and water-based alkyd resin-WX1440 are not added to the formula;

[0057] The preparation method of the water-based artistic paint is consistent with that of Example 1.

[0058] The water-based art paints prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested for relevant properties, and the test method was as follows:

[0059] Mechanical stability: simulated by centrifugal accelerated sedimentation test. Pour an appropriate amount of water-based art paint into a clean dry centrifuge tube, put it into a centrifuge for 15 minutes, the speed is 3000r / min, and if there is no precipitation in the water-based art paint after taking it out, it can be proved that the water-based art paint can be stably stored for 90 days.

[0060] Storage stability: Leave it at room temperature and observe whether stratification occurs. The stratification time is used as the standard for stability determination. The stratification time of an emulsion with poor stability is several days or even hours; the stratification time of an emulsion with good stability is 2 to 3 months; and the stratification time of an emulsion with good stability can reach more than 3 months.

[0061] Coating adhesion test: Use the cross-cut test. On the painted sample, use a special cross-cut knife to evenly draw 11 parallel cutting lines perpendicular to the sample surface, and then draw another 11 parallel cutting lines at a 90-degree angle to these cutting lines to form a grid pattern. Clean the sample surface and stick the tape in the center of the grid, and then tear off the tape continuously and smoothly. According to the degree of shedding, evaluate the adhesion level. The test results are divided into 5 levels, where 0-20 indicates severe shedding and 80-100 indicates intact. According to GB / T9286-1988, adhesion = (small grids that have not fallen off / total number of grids) × 100%.

[0062] Salt spray resistance test: in accordance with GB / T1771-91.

[0063] Water resistance test: in accordance with GB / T1733-1993.

[0064] The test results are shown in Table 1:

[0065] Table 1

[0066]

[0067] As can be seen from Table 1, a hydroxy-terminated polydimethylsiloxane is introduced into the reaction system of polyisocyanate and polyether polyol, a polyurethane prepolymer is generated by the reaction of polyisocyanate and polyether polyol, and then further reacted with the hydroxy-terminated polydimethylsiloxane to graft the siloxane group onto the polyurethane chain, which can effectively improve the mechanical strength of the polyurethane and improve its hydrophobicity and high temperature resistance. On the other hand, the water-based alkyd resin is combined with the epoxy resin and the polyurethane to form a three-dimensional network structure, which further improves the wear resistance of the coating, and the water-based alkyd resin is further cross-linked with the hydroxy-terminated polydimethylsiloxane, and the main chain end or side chain of the alkyd resin is connected with the polysiloxane to form a block, graft or interpenetrating network copolymer, thereby synergistically improving the water resistance, corrosion resistance and wear resistance of the water-based art paint.

[0068] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0069] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A water-resistant and friction-resistant water-based artistic paint, characterized in that: According to weight parts, it includes the following components: 70-90 parts of polyisocyanate, 60-90 parts of polyether polyol, 10-20 parts of terminal hydroxyl polydimethylsiloxane, 3-6 parts of epoxy resin, 10-20 parts of hydrophilic chain extender, 6-10 parts of small molecule chain extender, 0.1-1.5 parts of cross-linking agent, 0.6-1.2 parts of catalyst, 8-18 parts of neutralizer, 10-25 parts of natural pigment, 10-20 parts of water-based alkyd resin, 1-3 parts of leveling agent, 0.5-1 part of defoamer, 3-6 parts of thickener, 450-500 parts of ice-water mixture.

2. The water-resistant and friction-resistant water-based artistic paint according to claim 1, characterized in that: The polyether polyol is selected from at least one of polypropylene glycol, polytetramethylene glycol and polyethylene glycol, or a combination of two or more thereof.

3. The water-resistant and friction-resistant water-based artistic paint according to claim 1, characterized in that: The polyisocyanate is one or a combination of two or more of isophorone diisocyanate, dicyclohexylmethane diisocyanate, 1,6-hexyl diisocyanate, and tetramethylcyclohexylmethane diisocyanate.

4. The water-resistant and friction-resistant water-based artistic paint according to claim 1, characterized in that: The molecular weight of the hydroxy-terminated polydimethylsiloxane is 1900-2200.

5. The water-resistant and friction-resistant water-based artistic paint according to claim 1, characterized in that: The natural pigment is one of red yeast rice pigment, purple cabbage pigment, chrysanthemum yellow pigment, gardenia yellow pigment and gardenia green pigment.

6. The water-resistant and friction-resistant water-based artistic paint according to claim 1, characterized in that: The hydrophilic chain extender is one or a combination of two of dimethylolbutyric acid, dimethylolpropionic acid, and sodium aminosulfonate; And / or, the small molecule chain extender is one or a combination of two of diethylene glycol, methyl propylene glycol, 1,4-butanediol, and neopentyl glycol; and / or, the cross-linking agent is one of trimethylolpropane and trimethylolethane; And / or, the catalyst is one of dibutyltin dilaurate and organic bismuth.

7. The water-resistant and friction-resistant water-based artistic paint according to claim 1, characterized in that: The neutralizing agent is any one of triethylamine and diethanolamine; and / or, the leveling agent is an organosilicon surfactant; and / or, the defoaming agent is a polysiloxane copolymer defoaming agent; And / or, the thickener is a polyurethane associative thickener.

8. A method for preparing the water-resistant and friction-resistant water-based artistic paint according to claim 1, characterized in that: The following steps are involved: S1. Mix polyether polyol, terminal hydroxyl polydimethylsiloxane and polyisocyanate evenly, and react at 85-95°C for 2-3h; add hydrophilic chain extender, small molecule chain extender, crosslinking agent and catalyst, and react at 60-75°C for 2-3h; add epoxy resin and react at 60°C for 0.5-1h; then cool to 35-45°C, add neutralizer for neutralization, and add ice-water mixture and water-based alkyd resin to the obtained mixture under shearing action for emulsification to obtain modified polyurethane emulsion; S2. Add natural pigment to the modified polyurethane emulsion and stir at 50°C for 1 to 1.5 hours; then add leveling agent, defoaming agent and thickener and stir to mix evenly to obtain water-resistant and friction-resistant water-based art paint.

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