Hydrophobic stain-resistant hydroxy acrylic resin as well as preparation method and application thereof

Abstract

The invention discloses hydrophobic stain-resistant hydroxy acrylic resin as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. The preparation method comprises the following steps: (1) under the protection of inert gas, adding neopentyl glycol, trimethylolpropane, an acrylic monomer and an initiator into a reaction kettle, heating to 150-200 DEG C, then adding a catalyst for esterification reaction for 3-4 hours, cooling to room temperature after the reaction is finished, and then adding a solvent for dilution to obtain a hydroxy acrylic resin prepolymer; (2) preparing polymer coated nano silicon dioxide sol; and (3) adding the polymer coated nano silicon dioxide sol into the hydroxy acrylic resin prepolymer, and uniformly mixing to obtain the hydrophobic stain-resistant hydroxy acrylic resin. The hydrophobic stain-resistant hydroxy acrylic resin disclosed by the invention has good waterproof stain-resistant performance and mechanical performance, and can be widely applied to the fields of buildings, automobiles, ships, furniture and the like.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a hydrophobic and stain-resistant hydroxy acrylic resin and a preparation method and application thereof. Background Art

[0002] With the continuous development of science and technology, polymer materials are increasingly used in various fields. However, traditional hydroxyl acrylic resins and polyurethane varnishes have obvious deficiencies in terms of waterproofness and stain resistance, and cannot meet the high requirements of modern industry and life. Therefore, the development of a new type of hydrophobic and stain-resistant hydroxyl acrylic resin and polyurethane varnish has important practical significance and broad application prospects. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a hydrophobic and stain-resistant hydroxy acrylic resin and its preparation method and application. The hydrophobic and stain-resistant hydroxy acrylic resin of the present invention has good waterproof and stain-resistant properties and mechanical properties, and can be widely used in the fields of construction, automobiles, ships, furniture, etc.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, comprising the following steps:

[0006] (1) Preparation of hydroxy acrylic resin prepolymer: under the protection of inert gas, 15-30 parts by weight of neopentyl glycol, 10-20 parts by weight of trimethylolpropane, 30-50 parts by weight of acrylic acid monomer, and 3-8 parts by weight of initiator are added into a reaction kettle, heated to 150-200° C., and then 0.05-0.2 parts by weight of catalyst are added to carry out esterification reaction for 3-4 hours. After the reaction is completed, the temperature is cooled to room temperature, and then 15-20 parts by weight of solvent is added to dilute, thereby obtaining a hydroxy acrylic resin prepolymer;

[0007] (2) Preparation of polymer-coated nano-silica sol:

[0008] S1: Add 2-5 parts by weight of hexadecyltrimethoxysilane to 150-200 mL of water, stir evenly, then add 20-30 parts by weight of nano-silicon dioxide, and filter after reaction to obtain a silica colloidal solution;

[0009] S2: 3-8 parts by mass of a copolymer of methyl methacrylate and butyl acrylate is mixed evenly with 100-150 mL of water, and then the nano silica colloidal solution described in S1 is added, mixed and stirred for 1-2 hours, filtered and dried to obtain the polymer-coated nano silica sol;

[0010] (3) Adding the polymer-coated nano-silica sol into the hydroxy acrylic resin prepolymer and mixing them evenly to obtain a hydrophobic and stain-resistant hydroxy acrylic resin.

[0011] The invention adopts hexadecyltrimethoxysilane to chemically modify nano silicon dioxide, which is beneficial to improving the surface performance of nano silicon dioxide and making the nano silicon dioxide have good hydrophobicity; and methyl methacrylate and butyl acrylate copolymer emulsion is coated on the surface of nano silicon dioxide modified by hexadecyltrimethoxysilane, which is beneficial to improving the dispersibility of nano silicon dioxide in hydroxy acrylic resin prepolymer, thereby further improving the hydrophobic performance of hydrophobic and stain-resistant hydroxy acrylic resin, and also beneficial to improving the mechanical properties of hydrophobic and stain-resistant hydroxy acrylic resin.

[0012] Preferably, in step (1), the initiator comprises at least one of di-tert-butyl peroxide, di-tert-amyl peroxide, benzoyl peroxide, tert-butyl benzoyl peroxide, and methyl ethyl ketone peroxide.

[0013] Preferably, in step (1), the catalyst comprises at least one of dibutyltin oxide and dibutyltin dilaurate.

[0014] Preferably, in step (1), the solvent comprises ethyl acetate or toluene.

[0015] Preferably, in step (2), the average particle size of the nano-silicon dioxide is 15-30 nm, more preferably 20-30 nm.

[0016] The present invention controls the particle size of nano-silica so that the methyl methacrylate and butyl acrylate copolymer emulsion is better coated on the surface of the nano-silica modified by hexadecyltrimethoxysilane, which is beneficial to further improve the dispersibility of the nano-silica in the hydroxy acrylic resin prepolymer, thereby improving the hydrophobicity and mechanical properties of the hydrophobic and stain-resistant hydroxy acrylic resin.

[0017] Preferably, in step (3), the mass ratio of the polymer-coated nano-silica sol to the hydroxylated acrylic resin prepolymer is (8-15): (85-92).

[0018] In a second aspect, the present invention also provides a hydrophobic and stain-resistant hydroxy acrylic resin prepared by the above method.

[0019] In a third aspect, the present invention further provides a polyurethane varnish, wherein component A comprises the following components by weight: 100 parts of a hydrophobic and stain-resistant hydroxy acrylic resin; 1-3 parts of a pigment; 10-20 parts of a filler; 3-5 parts of an additive; and 5-10 parts of a solvent;

[0020] Component B includes the following components: 15-20 parts of isocyanate curing agent.

[0021] The hydrophobic and stain-resistant hydroxy acrylic resin of the present invention has extremely strong hydrophobicity and stain resistance, can effectively resist the attachment of water and stains, and keep the coating surface clean and beautiful. In addition, it also has excellent physical and mechanical properties and can meet the needs of different application scenarios.

[0022] Preferably, the auxiliary agent includes at least one of a leveling agent, a defoaming agent and a dispersant.

[0023] Preferably, the leveling agent is a polyurethane leveling rheological agent.

[0024] Preferably, the defoaming agent is a silicone defoaming agent.

[0025] Preferably, the dispersant includes dispersant TENLO70 or dispersant SDJ8005.

[0026] In a fourth aspect, the present invention further provides a method for preparing a polyurethane varnish, comprising the following steps:

[0027] (1) uniformly mixing the components in component A according to the proportions to obtain component A;

[0028] (2) During construction, mix component A and component B in a weight ratio of 1:(1.5-2).

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) Excellent hydrophobic and stain-resistant properties: By introducing a hydrophobic and stain-resistant agent, the prepared resin and varnish surface have extremely strong hydrophobicity and stain resistance, which can effectively resist the adhesion of moisture and stains, keeping the coating surface clean and beautiful.

[0031] (2) Good physical and mechanical properties: The resin and varnish of the present invention have excellent physical and mechanical properties while maintaining hydrophobic and stain-resistant properties, and can meet the needs of different application scenarios.

[0032] (3) Environmental protection and safety: The raw materials used in the preparation process of the present invention all meet environmental protection requirements, and no harmful substances are generated during the preparation process, which is environmentally friendly. At the same time, the prepared resin and varnish also have good safety performance during use.

[0033] (4) Easy construction: The resin and varnish of the present invention have good construction performance and can be easily applied to the surface of various substrates by spraying, brushing, etc. to form a uniform and continuous coating.

[0034] (5) Wide application: Since the resin and varnish of the present invention have excellent properties, they can be widely used in the fields of construction, furniture, automobiles, ships, electronics, etc., providing long-lasting protection for various substrates. DETAILED DESCRIPTION

[0035] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the protection scope and implementation methods of the present invention are not limited thereto.

[0036] Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0037] Methyl methacrylate and butyl acrylate copolymer emulsion: Guangdong Wengjiang Chemical Reagent Co., Ltd., CAS: 25852-37-3.

[0038] Methacrylic acid-methyl methacrylate copolymer emulsion: Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0039] Polyurethane leveling rheological agent: BYK, BYK333.

[0040] Silicone defoamer: TEGO ARIEX 902W, Evonik.

[0041] The following examples and comparative examples all use the above-mentioned raw materials.

[0042] Example 1

[0043] This embodiment discloses a method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, comprising the following steps:

[0044] (1) Preparation of hydroxy acrylic resin prepolymer: by weight, under nitrogen protection, add 15 parts of neopentyl glycol, 10 parts of trimethylolpropane, 30 parts of acrylic acid monomer, and 3 parts of initiator into a reaction kettle, heat to 150° C., then add 0.05 parts of catalyst to carry out esterification reaction for 3 hours, cool to room temperature after the reaction, and then add 15 parts of solvent to dilute, thereby obtaining a hydroxy acrylic resin prepolymer;

[0045] The initiator is benzoyl peroxide; the catalyst is dibutyltin oxide; and the solvent is ethyl acetate.

[0046] (2) Preparation of polymer-coated nano-silica sol:

[0047] S1: Add 2 parts of hexadecyltrimethoxysilane to 150 mL of water, stir evenly, then add 20 parts of nano-silicon dioxide, and filter after reaction to obtain a silica colloidal solution; the particle size of the nano-silicon dioxide is 15 nm;

[0048] S2: Mix 3 parts of methyl methacrylate and butyl acrylate copolymer emulsion with 100 mL of water, then add the nano silica colloidal solution in S1, mix and stir for 1 hour, filter and dry to obtain the polymer-coated nano silica sol.

[0049] (3) By weight, 8 parts of polymer-coated nano-silica sol were added to 92 parts of hydroxyl acrylic resin prepolymer, and the mixture was mixed evenly to obtain a hydrophobic and stain-resistant hydroxyl acrylic resin.

[0050] This embodiment also discloses a polyurethane varnish, wherein component A comprises the following components by weight: 100 parts of hydrophobic and stain-resistant hydroxy acrylic resin; 1 part of pigment; 10 parts of filler; 3 parts of additive; 5 parts of solvent;

[0051] The pigment is titanium dioxide; the filler is silicon dioxide; the additives include leveling agent, defoamer, and dispersant, and the mass ratio is 1:1:1. The leveling agent is a polyurethane leveling rheological agent, the defoamer is an organosilicon defoamer, and the dispersant is TENLO70; the solvent is ethyl acetate;

[0052] Component B includes the following components: 15 parts of an isocyanate curing agent, the isocyanate curing agent includes toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI), and the mass ratio of TDI:HDI is 1:2.

[0053] This embodiment also discloses a method for preparing a polyurethane varnish, comprising the following steps:

[0054] (1) uniformly mixing the components in component A according to the proportions to obtain component A;

[0055] (2) During construction, mix component A and component B in a weight ratio of 1:1.5.

[0056] Example 2

[0057] This embodiment discloses a method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, comprising the following steps:

[0058] (1) Preparation of hydroxy acrylic resin prepolymer: by weight, under nitrogen protection, 30 parts of neopentyl glycol, 20 parts of trimethylolpropane, 50 parts of acrylic acid monomer, and 8 parts of initiator were added to a reaction kettle, heated to 200° C., and then 0.2 parts of catalyst were added to carry out esterification reaction for 4 hours. After the reaction was completed, the temperature was cooled to room temperature, and 20 parts of solvent was added to dilute, thereby obtaining a hydroxy acrylic resin prepolymer;

[0059] The initiator is benzoyl peroxide; the catalyst is dibutyltin oxide; and the solvent is ethyl acetate.

[0060] (2) Preparation of polymer-coated nano-silica sol:

[0061] S1: Add 5 parts of hexadecyltrimethoxysilane to 200 mL of water, stir evenly, then add 30 parts of nano-silicon dioxide, and filter after reaction to obtain a silica colloidal solution; the particle size of the nano-silicon dioxide is 15 nm;

[0062] S2: 8 parts of methyl methacrylate and butyl acrylate copolymer emulsion were mixed with 150 mL of water, and then the nano silica colloidal solution described in S1 was added. After mixing and stirring for 2 hours, the mixture was filtered and dried to obtain the polymer-coated nano silica sol.

[0063] (3) By weight, 15 parts of polymer-coated nano-silica sol were added to 85 parts of hydroxyl acrylic resin prepolymer, and the mixture was mixed evenly to obtain a hydrophobic and stain-resistant hydroxyl acrylic resin.

[0064] This embodiment also discloses a polyurethane varnish, wherein component A comprises the following components by weight: 100 parts of a hydrophobic and stain-resistant hydroxy acrylic resin; 3 parts of a pigment; 20 parts of a filler; 5 parts of an additive; and 10 parts of a solvent.

[0065] The pigment is titanium dioxide; the filler is silicon dioxide; the additives include leveling agent, defoamer, and dispersant, and the mass ratio is 1:1:1. The leveling agent is a polyurethane leveling rheological agent, the defoamer is an organosilicon defoamer, and the dispersant is TENLO70; the solvent is ethyl acetate;

[0066] Component B includes the following components: 20 parts of an isocyanate curing agent, the isocyanate curing agent includes toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI), and the mass ratio of TDI:HDI is 1:2.

[0067] This embodiment also discloses a method for preparing a polyurethane varnish, comprising the following steps:

[0068] (1) uniformly mixing the components in component A according to the proportions to obtain component A;

[0069] (2) During construction, mix component A and component B in a weight ratio of 1:2.

[0070] Example 3

[0071] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the average particle size of the nano-silicon dioxide is 20 nm.

[0072] Example 4

[0073] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the average particle size of the nano-silicon dioxide is 25 nm.

[0074] Example 5

[0075] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the average particle size of the nano-silicon dioxide is 30 nm.

[0076] Comparative Example 1

[0077] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (1), an equal mass of methacrylic acid-methyl methacrylate copolymer emulsion is used to replace the methyl methacrylate and butyl acrylate copolymer emulsion.

[0078] Comparative Example 2

[0079] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), an equal mass of silane coupling agent KH-560 is used to replace hexadecyltrimethoxysilane.

[0080] Comparative Example 3

[0081] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the amount of hexadecyltrimethoxysilane used is 1 part.

[0082] Comparative Example 4

[0083] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the amount of hexadecyltrimethoxysilane used is 7 parts.

[0084] Comparative Example 5

[0085] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the amount of nano-silicon dioxide used is 15 parts.

[0086] Comparative Example 6

[0087] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the amount of nano-silicon dioxide used is 35 parts.

[0088] Comparative Example 7

[0089] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the amount of the methyl methacrylate and butyl acrylate copolymer emulsion is 1 part.

[0090] Comparative Example 8

[0091] A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, which is different from Example 1 only in that in step (2), the amount of the methyl methacrylate and butyl acrylate copolymer emulsion is 10 parts.

[0092] In order to verify the performance of the hydrophobic and stain-resistant hydroxy acrylic resin and polyurethane varnish of the present invention, the polyurethane varnish prepared in each embodiment and comparative example was sprayed on tinplate, and after being surface dried for 5 minutes, it was baked at 150° C. for 25 minutes.

[0093] 1. Water contact angle test of coating: Use CAT contact angle tester to test the static contact angle between coating and deionized water (2μL). The larger the contact angle, the better the hydrophobic effect.

[0094] 2. Water resistance: Immerse the glass substrate sprayed with a 25±3μm paint film in deionized water at 30°C and observe the time (d) for the paint film to bubble and fall off.

[0095] 3. Adhesion test with glass substrate: The adhesion grade shall be evaluated according to GB / T 9286-1998 paint film adhesion test standard.

[0096] 4. Hardness: Tested in accordance with GB / T6739-2006 standard, the higher the hardness grade, the greater the hardness.

[0097] 5. Gloss: Tested in accordance with GB / T9754-2007 standard.

[0098] 6. Abrasion resistance: The surface of the coating was polished with RCA paper tape, produced by Norman Tool Company.

[0099] The above test results are shown in Table 1.

[0100] Table 1

[0101]

[0102]

[0103] According to Examples 1-5 in Table 1, the hydrophobic and stain-resistant hydroxy acrylic resin and polyurethane varnish of the present invention have excellent hydrophobicity and stain resistance, as well as excellent water resistance, adhesion, hardness and wear resistance.

[0104] By comparing Comparative Examples 1-2 with Example 1, it can be seen that in Comparative Example 1, other types of copolymer emulsions are used to replace methyl methacrylate and butyl acrylate copolymer emulsions, and the water contact angle of the coating is much lower than that of Example 1; in Comparative Example 2, silane coupling agent KH-560 is used to replace hexadecyltrimethoxysilane to modify the nano-silica, and the hydrophobicity of the coating is also not as good as that of Example 1, indicating that the hydrophobicity of the hydrophobic and stain-resistant hydroxy acrylic resin can be greatly improved only by chemically modifying the nano-silica with hexadecyltrimethoxysilane and coating the methyl methacrylate and butyl acrylate copolymer emulsion on the surface of the nano-silica modified with hexadecyltrimethoxysilane.

[0105] By comparing Comparative Examples 3-8 with Example 1, it can be seen that the amount of hexadecyltrimethoxysilane in Comparative Examples 3-4 is not within the range defined by the present invention, and the hydrophobicity of the coating is not as good as that of Example 1; the amount of nano-silicon dioxide in Comparative Examples 4-6 is not within the range defined by the present invention, and the hydrophobicity of the coating is not as good as that of Example 1; the amount of methyl methacrylate and butyl acrylate copolymer emulsion in Comparative Examples 7-8 is not within the range defined by the present invention, and the hydrophobicity of the coating is not as good as that of Example 1. This shows that the present invention can further improve the hydrophobicity of the coating by controlling the amount of hexadecyltrimethoxysilane, nano-silicon dioxide and methyl methacrylate and butyl acrylate copolymer emulsion within the range defined by the present invention, and is also beneficial to improving the mechanical properties of the coating.

[0106] By comparing Examples 3-5 with Example 1, it can be seen that as the particle size of nano-silicon dioxide gradually increases, the hydrophobicity of the coating first increases and then decreases, indicating that the present invention is conducive to further improving the hydrophobicity of the coating by setting the particle size of nano-silicon dioxide to 20-30nm. In addition, the wear resistance of the coating gradually increases, indicating that by controlling the particle size of nano-silicon dioxide within the range defined by the present invention, it is also conducive to improving the wear resistance of the coating.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a hydrophobic and stain-resistant hydroxy acrylic resin, characterized in that: The following steps are involved: (1) Preparation of hydroxy acrylic resin prepolymer: under the protection of inert gas, 15-30 parts by weight of neopentyl glycol, 10-20 parts by weight of trimethylolpropane, 30-50 parts by weight of acrylic acid monomer, and 3-8 parts by weight of initiator are added into a reaction kettle, heated to 150-200° C., and then 0.05-0.2 parts by weight of catalyst are added to carry out esterification reaction for 3-4 hours. After the reaction is completed, the temperature is cooled to room temperature, and then 15-20 parts by weight of solvent is added to dilute, thereby obtaining a hydroxy acrylic resin prepolymer; (2) Preparation of polymer-coated nano-silica sol: S1: adding 2-5 parts by weight of hexadecyltrimethoxysilane to water, stirring evenly, and then adding 20-30 parts by weight of nano-silicon dioxide, and filtering after the reaction to obtain a silica colloidal solution; S2: uniformly mixing 3-8 parts by weight of a copolymer of methyl methacrylate and butyl acrylate with water, then adding the nano silica colloidal solution described in S1, mixing and stirring, then filtering and drying to obtain the polymer-coated nano silica sol; (3) Adding the polymer-coated nano-silica sol into the hydroxy acrylic resin prepolymer and mixing them evenly to obtain a hydrophobic and stain-resistant hydroxy acrylic resin.

2. The method for preparing the hydrophobic and stain-resistant hydroxy acrylic resin according to claim 1, characterized in that: In step (1), the initiator includes at least one of di-tert-butyl peroxide, di-tert-amyl peroxide, benzoyl peroxide, tert-butyl benzoyl peroxide, and methyl ethyl ketone peroxide.

3. The method for preparing the hydrophobic and stain-resistant hydroxy acrylic resin according to claim 1, characterized in that: In step (1), the catalyst includes at least one of dibutyltin oxide and dibutyltin dilaurate.

4. The method for preparing the hydrophobic and stain-resistant hydroxy acrylic resin according to claim 1, characterized in that: In step (2), the average particle size of the nano-silicon dioxide is 15-30 nm.

5. The method for preparing the hydrophobic and stain-resistant hydroxy acrylic resin according to claim 1, characterized in that: In step (3), the mass ratio of the polymer-coated nano-silica sol to the hydroxylated acrylic resin prepolymer is (8-15): (85-92).

6. The hydrophobic and stain-resistant hydroxy acrylic resin prepared by the preparation method according to any one of claims 1 to 5.

7. A polyurethane varnish, characterized in that: Component A includes the following components by mass: 100 parts of the hydrophobic and stain-resistant hydroxy acrylic resin according to claim 6; 1-3 parts of pigment; 10-20 parts of filler; 3-5 parts of additive; 5-10 parts of solvent; Component B includes the following components: 15-20 parts of isocyanate curing agent.

8. The polyurethane varnish according to claim 7, characterized in that The auxiliary agent includes at least one of a leveling agent, a defoaming agent and a dispersant.

9. The polyurethane varnish according to claim 8, characterized in that The leveling agent is a polyurethane leveling rheological agent, the defoaming agent is a silicone defoaming agent, and the dispersant includes dispersant TENLO70 or dispersant SDJ8005.

10. The method for preparing the polyurethane varnish according to any one of claims 7 to 9, characterized in that: The following steps are involved: (1) uniformly mixing the components in component A according to the proportions to obtain component A; (2) During construction, mix component A and component B in a weight ratio of 1:(1.5-2).

Images