Polymers and coatings

Abstract

The invention provides a polymer and a coating, the polymer is formed by polymerizing a plurality of monomers, the monomers comprise a first monomer, a second monomer and a third monomer, and the first monomer is itaconic acid; the second monomer is methacrylic acid C1-4 alkyl ester, styrene, isobornyl acrylate, itaconic acid di-C2-4 alkyl ester or a combination thereof; and the third monomer is 2-octyl acrylate, C9-12 alkyl acrylate or a combination thereof. The coating contains the polymer.

Description

Technical Field

[0001] The present invention relates to aqueous coatings, and particularly to polymers used therein. Background Art

[0002] In order to improve the working environment and safety, it has become a trend to replace solvents with water in coatings, adhesives, molding materials, medical materials, and electronic materials. However, general aqueous coatings have poor adhesion to metal substrates and shrink after drying. In addition, when existing aqueous resins are formulated into aqueous coatings, a dispersant is generally required to form a non-caking coating with pigment powders.

[0003] In summary, there is an urgent need for new aqueous resins to overcome the above problems. Summary of the Invention

[0004] The polymer provided by an embodiment of the present invention is polymerized from a plurality of monomers, and the monomers include a first monomer, a second monomer, and a third monomer. The first monomer is itaconic acid; the second monomer is C 1-4 alkyl methacrylate, styrene, isobornyl acrylate, di(C 2-4 alkyl)itaconate, or a combination thereof; and the third monomer is 2-octyl acrylate, C 9-12 alkyl acrylate, or a combination thereof.

[0005] The coating provided by an embodiment of the present invention includes: 100 parts by weight of the above polymer; and 100 to 300 parts by weight of water. Detailed Description

[0006] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments.

[0007] The polymer provided by an embodiment of the present invention is polymerized from a plurality of monomers, and the monomers include a first monomer, a second monomer, and a third monomer. The first monomer is itaconic acid; the second monomer is C 1-4 alkyl methacrylate (C 1-4 alkyl methacrylate), styrene, isobornyl acrylate, di(C 2-4 alkyl)itaconate, or a combination thereof; and the third monomer is 2-octyl acrylate, C 2-4 alkyl acrylate (C 9-12 alkyl acrylate), or a combination thereof. 9-12

[0008] The above-mentioned first monomer and second monomer belong to the hard segment of the polymer, while the third monomer belongs to the soft segment of the polymer. In some embodiments, the ratio between the total weight of the first monomer and the second monomer and the weight of the third monomer (i.e., hard segment: soft segment) is 150:20 to 400:1200.

[0009] In some embodiments, the weight ratio of the first monomer to the second monomer is 100:40 to 100:1600.

[0010] In some embodiments, the weight ratio of the first monomer to the third monomer is 100:50 to 100:1900.

[0011] In some embodiments, the C 1-4 alkyl methacrylate may be methyl methacrylate or other suitable C alkyl methacrylates. In some embodiments, the di-C 2-4 alkyl itaconate includes dibutyl itaconate or other suitable di-C alkyl itaconates. In some embodiments, the C 9-12 alkyl acrylate includes lauryl acrylate or other suitable C alkyl acrylates.

[0012] The above-mentioned polymer is an aqueous resin, which can be self-emulsified in water to form an emulsion, and the formed emulsion can be used as a coating.

[0013] A coating provided by an embodiment of the present invention includes: 100 parts by weight of the above-mentioned polymer; and 100 to 700 parts by weight of water. The water can be the water used when synthesizing the polymer. In some embodiments, water can be additionally added. If the amount of water used is too low, the coating is likely to agglomerate. If the amount of water used is too high, the coating is too dilute to adhere closely to the substrate.

[0014] In some embodiments, the above coating further comprises 0.1 to 200 parts by weight of a pigment powder. If the amount of the pigment powder used is too large, it may agglomerate and be unable to disperse. For example, the pigment powder may be a yellow inorganic pigment such as cadmium yellow (PY35, C.I. 77205, CAS# 12237-67-1), titanium nickel yellow (PY53, C.I. 77788, CAS# 8007-18-9), praseodymium zirconium yellow (PY159, C.I. 77997, CAS# 68187-15-5), chrome titanium yellow (PY162, C.I. 77896, CAS# 68611-42-7; PY163, C.I. 77897, CAS# 68186-92-5) or bismuth yellow (PY184, C.I. 771740, CAS# 14059-33-7); a magenta inorganic pigment such as iron oxide red (PR101, C.I. 77491, CAS# 1317-60-8), cadmium red (PR108, C.I. 77202, CAS# 58339-34-7), lead chromate red (PR104, C.I. 77605, CAS# 12656-85-8; PR105, C.I. 77578, CAS# 1314-41-6) or iron zirconium red (PR232, C.I. 77996, CAS# 68412-79-3); a cyan inorganic pigment such as cobalt blue (PB28, C.I. 77364, CAS# 68187-40-6) or cobalt chromium blue (PB36, C.I. 77343, CAS# 68187-11-1); a black inorganic pigment such as manganese ferrite black (PBK26, C.I. 77494, CAS# 68186-94-7; PBK33, C.I. 77537, CAS# 75864-23-2), cobalt iron chromium black (PBK27, C.I. 77502, CAS# 68186-97-0), copper chromium black (PBK28, C.I. 77428, CAS# 68186-91-4), chromium iron black (PBK30, C.I. 77504, CAS# 71631-15-7) or titanium black (PBK35, C.I. 77890, CAS# 70248-09-8); a white inorganic pigment such as titanium white (PW6, C.I. 77891, CAS# 13463-67-7), zirconium white (PW12, C.I. 77990, CAS# 1314-23-4) or zinc white (PW4, C.I. 77947, CAS# 1314-13-2); an orange inorganic pigment such as cadmium orange (PO20, C.I. 77199, CAS# 12656-57-4) or orange chrome yellow (PO21, C.I. 77601, CAS# 1344-38-3); a green inorganic pigment such as chrome green (PG17, C.I.77288, CAS#1308-38-9), cobalt green (PG19, C.I. 77335, CAS#8011-87-8), cobalt chromium green (PG26, C.I. 77344, CAS#68187-49-5) or cobalt titanium green (PG50, C.I. 77377, CAS#68186-85-6). In some embodiments, the pigment powder is titanium white such as titanium dioxide.

[0015] In some embodiments, the above coating further comprises 0.1 to 20 parts by weight of a film-forming agent, defoamer, dispersant, leveling agent or a combination thereof to further improve the properties of the coating. If the dosage of the film-forming agent, defoamer, dispersant, leveling agent or the combination thereof is too high, it will affect the physical properties of the coating, such as possible formation of white fog and peeling.

[0016] The above coating has good film-forming properties and good adhesion to metal substrates, can be stably stored for a long time, and the formed coating has good antistatic properties. Since only water is required instead of organic solvents for synthesizing the polymer, the process is environmentally friendly. In addition, the raw material of the polymer contains itaconic acid, so the biomass content of the polymer can be increased.

[0017] To make the above content, other objects, features and advantages of the present invention more obvious and understandable, the following specific embodiments are given and described in detail as follows:

[0018] In the following embodiments, the surfactant used for preparing the polymer can be an anionic surfactant, cationic surfactant, non-ionic surfactant or a combination thereof, mainly used to assist the polymerization reaction, and those of ordinary skill in the art can select and use it according to requirements.

[0019] In the following embodiments, the method for measuring the solid content of the emulsion is to place the emulsion in an oven at 120 °C for 3 hours and then weigh the percentage difference in weight before and after drying. The method for measuring the thermal decomposition temperature (Td) of the polymer is thermogravimetric analysis (TGA). The method for measuring the viscosity of the emulsion is measured using a Brookfield KU-2 Viscometer. The method for measuring the film-forming temperature of the emulsion is in accordance with ISO 2115:1996. The criterion for judging the film-forming property of the emulsion is to visually observe whether there is a shrinkage phenomenon after the emulsion is coated on the substrate. The method for measuring the surface impedance of the film formed by the emulsion at different humidities is in accordance with ANSI / ESD STM11.11-2015. The method for measuring the adhesion of the film formed by the emulsion is the cross-cut test method (ASTM D3359). The method for measuring the stability (Turbiscan Stability Index; TSI) after mixing the emulsion with titanium oxide powder is to use a dispersion stability analyzer, and the sample is placed in the analyzer and measured for 24 hours to calculate the change amount of the sample.

[0020] Example 1

[0021] Take 22 parts by weight of itaconic acid, 16 parts by weight of methyl methacrylate, 62 parts by weight of 2-octyl acrylate and 10 parts by weight of surfactant, add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of the initiator ammonium persulfate and add it. Stir and heat to 75 °C and react for 5 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion with a solid content of 37.74%. The thermal decomposition temperature of the polymer is 350 °C. The viscosity of the emulsion is 159 cps. The film-forming temperature of the emulsion is 11 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and a relative humidity of 60% is 10 5 Ω / square, while the surface impedance of the film layer at 25 °C and a relative humidity of 30% is 10 6 Ω / square. The smaller the surface impedance of the film layer, the better the antistatic ability of the film layer. Coating the emulsion on aluminum plates and galvanized steel plate metal substrates respectively and then drying to form a film, the adhesion of the film layer is 5B for both and there is no shrinkage.

[0022] Example 2

[0023] Take 15 parts by weight of itaconic acid, 13 parts by weight of methyl methacrylate, 72 parts by weight of lauryl acrylate and 10 parts by weight of surfactant, add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of the initiator ammonium persulfate and add it. Stir and heat to 75 °C and react for 5 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion with a solid content of 43.26%. The film-forming temperature of the emulsion is 11 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and a relative humidity of 60% is 10 5 Ω / square, while the surface impedance of the film layer at 25 °C and a relative humidity of 30% is 10 6 Ω / square. Coating the emulsion on aluminum plates and galvanized steel plate metal substrates respectively and then drying to form a film, the adhesion of the film layer is 5B for both and there is no shrinkage.

[0024] Example 3

[0025] Take 5 parts by weight of itaconic acid, 23 parts by weight of dibutyl itaconate, 15 parts by weight of methyl methacrylate and 57 parts by weight of lauryl acrylate and 10 parts by weight of surfactant, add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of the initiator ammonium persulfate and add it. Stir and heat to 75 °C and react for 5 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion with a solid content of 45.60%. The film-forming temperature of the emulsion is 4 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and a relative humidity of 60% is 10 5 Ω / square, while the surface impedance of the film layer at 25 °C and a relative humidity of 30% is 10 6 Ω / square. Coating the emulsion on aluminum plates and galvanized steel plate metal substrates respectively and then drying to form a film, the adhesion of the film layer is 5B for both and there is no shrinkage.

[0026] Example 4

[0027] Take 40 parts by weight of itaconic acid, 40 parts by weight of dibutyl itaconate, 20 parts by weight of lauryl acrylate and 10 parts by weight of surfactant, add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of initiator ammonium persulfate, add it and stir and heat to 60 °C, then react for 2 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion, and the solid content is 35.40%. The film-forming temperature of the emulsion is 35 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and 60% relative humidity is 10 5 Ω / square, while the surface impedance of the film layer at 25 °C and 30% relative humidity is 10 5 Ω / square.

[0028] Example 5

[0029] Take 40 parts by weight of itaconic acid, 20 parts by weight of methyl methacrylate, 40 parts by weight of 2-octyl acrylate and 10 parts by weight of surfactant, add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of initiator ammonium persulfate, add it and stir and heat to 75 °C, then react for 5 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion, and the solid content is 33.54%. The film-forming temperature of the emulsion is 40 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and 60% relative humidity is 10 5 Ω / square, while the surface impedance of the film layer at 25 °C and 30% relative humidity is 10 5 Ω / square.

[0030] Example 6

[0031] Take 5 parts by weight of itaconic acid, 11 parts by weight of methyl methacrylate, 15 parts by weight of styrene, 18 parts by weight of isobornyl acrylate, 51 parts by weight of lauryl acrylate and 10 parts by weight of surfactant, add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of initiator ammonium persulfate, add it and stir and heat to 75 °C, then react for 5 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion, and the solid content is 43.29%. The film-forming temperature of the emulsion is 28.6 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and 60% relative humidity is 10 6 Ω / square, while the surface impedance of the film layer at 25 °C and 30% relative humidity is 10 7 Ω / square.

[0032] Example 7

[0033] Take 5 parts by weight of itaconic acid, 16 parts by weight of methyl methacrylate, 20 parts by weight of styrene, 44 parts by weight of isobornyl acrylate, 15 parts by weight of lauryl acrylate and 10 parts by weight of surfactant and add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of the initiator ammonium persulfate and add it. Stir and heat to 60 °C and then react for 2 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion with a solid content of 45.09%. The film-forming temperature of the emulsion is 50.2 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and a relative humidity of 60% is 10 6 Ω / square, and the surface impedance of the film layer at 25 °C and a relative humidity of 30% is 10 7 Ω / square.

[0034] Example 8

[0035] Take 40 parts by weight of itaconic acid, 20 parts by weight of styrene, 40 parts by weight of lauryl acrylate and 10 parts by weight of surfactant and add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of the initiator ammonium persulfate and add it. Stir and heat to 75 °C and then react for 5 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion with a solid content of 32.04%. The film-forming temperature of the emulsion is 45.2 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and a relative humidity of 60% is 10 6 Ω / square, and the surface impedance of the film layer at 25 °C and a relative humidity of 30% is 10 7 Ω / square.

[0036] Comparative Example 1

[0037] Take a commercially available aqueous emulsion (titration confirmed that its polymer contains -COOH). The film-forming temperature of the emulsion is 17 °C and the film-forming property is good. The surface impedance of the film layer at 25 °C and a relative humidity of 60% is 10 11 Ω / square, and the surface impedance of the film layer at 25 °C and a relative humidity of 30% is 10 11 Ω / square. After coating the emulsion on an aluminum plate metal substrate and drying to form a film, the adhesion of the film layer is 0B and it shrinks. It can be seen from Comparative Example 1 that the film layer formed by the emulsion of the present invention has a lower surface impedance (i.e., better antistatic property) than the film layer formed by the commercially available aqueous emulsion, and has better adhesion to the aluminum plate metal substrate.

[0038] Comparative Example 2

[0039] Take 7 parts by weight of itaconic acid, 22 parts by weight of acrylic acid, 70 parts by weight of lauryl acrylate, and 10 parts by weight of surfactant, add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of the initiator ammonium persulfate, add it, stir and heat to 75 °C, and then react for 5 hours to obtain a polymer. The polymer forms lumps and cannot be dispersed in water. It can be seen from Comparative Example 2 that not any monomer is suitable for reacting with itaconic acid to form an aqueous polymer.

[0040] Comparative Example 3

[0041] Take 5 parts by weight of itaconic acid, 23 parts by weight of dibutyl itaconate, 15 parts by weight of methyl methacrylate, 57 parts by weight of 2-ethylhexyl acrylate, and 10 parts by weight of surfactant, add them to 100 parts by weight of water. After stirring evenly, take 0.6 parts by weight of the initiator ammonium persulfate, add it, stir and heat to 75 °C, and then react for 5 hours to obtain a polymer. The polymer forms lumps and cannot be dispersed in water. It can be seen from Example 3 and Comparative Example 3 that not any monomer is suitable for reacting with itaconic acid to form an aqueous polymer.

[0042] Example 9

[0043] Take 30 parts by weight of the emulsion of Example 1, 30 parts by weight of titanium dioxide as a pigment powder, and 6.6 parts by weight of a wetting and dispersing agent (including a polysiloxane solution and an ester alcohol), mix them to form a coating. Coating the coating on aluminum plates and galvanized steel metal substrates respectively and then drying to form a film, the adhesion of the film layer is 5B for both.

[0044] Example 10

[0045] Take 30 parts by weight of the emulsion of Example 2, 30 parts by weight of titanium dioxide as a pigment powder, and 6.6 parts by weight of a wetting and dispersing agent (including a polysiloxane solution and an ester alcohol), mix them to form a coating. Coating the coating on aluminum plates and galvanized steel metal substrates respectively and then drying to form a film, the adhesion of the film layer is 5B for both.

[0046] Example 11

[0047] Take 30 parts by weight of the emulsion of Example 3, 30 parts by weight of titanium dioxide as a pigment powder, and 6.6 parts by weight of a wetting and dispersing agent (including a polysiloxane solution and an ester alcohol), mix them to form a coating. Coating the coating on aluminum plates and galvanized steel metal substrates respectively and then drying to form a film, the adhesion of the film layer is 5B for both. The TSI of the coating is 23.

[0048] Separately, take 30 parts by weight of the emulsion of Example 3 and 60 parts by weight of titanium dioxide as a pigment powder, mix them to form a coating. This coating is stable and does not form lumps, that is, the polymer in the emulsion itself has the function of dispersing titanium dioxide without additional wetting and dispersing agent.

[0049] Comparative Example 4

[0050] Take 30 parts by weight of a commercially available aqueous emulsion, 30 parts by weight of titanium dioxide as a pigment powder, and 10 parts by weight of a wetting and dispersing agent (including a polysiloxane solution and an ester alcohol), mix them to form a coating. Coat the coating on aluminum plates and galvanized steel sheet metal substrates respectively, and then dry to form a film. The adhesion of the film layer is 0B for both. The TSI of the coating is 30, and its stability is lower than that of the coating in Example 11 (the lower the TSI, the more stable).

[0051] In addition, take 30 parts by weight of a commercially available aqueous emulsion and 30 parts by weight of titanium dioxide as a pigment powder, and they agglomerate after mixing. The polymer in this emulsion has poor dispersibility for titanium dioxide, so an additional wetting and dispersing agent is needed to disperse titanium dioxide.

[0052] Comparative Example 5

[0053] Take 20 parts by weight of methyl methacrylate, 41 parts by weight of dibutyl itaconate, 39 parts by weight of 2-ethylhexyl acrylate, and 10 parts by weight of a surfactant, add them to 100 parts by weight of water, stir evenly, then add 0.6 parts by weight of an initiator ammonium persulfate, stir and heat to 75 °C, and react for 5 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion with a solid content of 43.99%.

[0054] Take 30 parts by weight of the above emulsion, 30 parts by weight of titanium dioxide as a pigment powder, and 6.6 parts by weight of a wetting and dispersing agent (including a polysiloxane solution and an ester alcohol), mix them to form a coating. Coat the coating on aluminum plates and galvanized steel sheet metal substrates respectively, and then dry to form a film. The film-forming property is poor and it will shrink. It can be seen from Comparative Example 5 that the polymer formed without itaconic acid is prone to shrinkage after film formation.

[0055] Comparative Example 6

[0056] Take 48.75 parts by weight of methyl methacrylate, 2.5 parts by weight of acrylic acid, 48.75 parts by weight of butyl acrylate, and 10 parts by weight of a surfactant, add them to 100 parts by weight of water, stir evenly, then add 0.6 parts by weight of an initiator ammonium persulfate, stir and heat to 75 °C, and react for 5 hours to obtain a polymer. The polymer is dispersed in water to form an emulsion with a solid content of 44.95%.

[0057] Take 30 parts by weight of the above emulsion, 30 parts by weight of titanium dioxide as a pigment powder, and 10 parts by weight of a wetting and dispersing agent (including a polysiloxane solution and an ester alcohol), mix them to form a coating. Coat the coating on aluminum and galvanized steel sheet metal substrates respectively, and then dry to form a film. The film-forming property is poor and it will shrink. It can be seen from Comparative Example 6 that the polymer formed without itaconic acid is prone to shrinkage after film formation.

[0058] The specific embodiments described above have further elaborated on the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A polymer is formed by polymerizing a plurality of monomers, and the monomers include a first monomer, a second monomer, and a third monomer; wherein the first monomer is itaconic acid; The second monomer is a C methacrylate 1-4 alkyl ester, styrene, isobornyl acrylate, di-C itaconate 2-4 alkyl ester or a combination thereof; and The third monomer is 2-octyl acrylate, C 9-12 alkyl acrylate or a combination thereof as described above.

2. The polymer according to claim 1, wherein the ratio between the total weight of the first monomer and the second monomer and the weight of the third monomer is 150:20 to 400:1200.

3. The polymer according to claim 1, wherein the weight ratio of the first monomer to the second monomer is 100:40 to 100:1600.

4. The polymer according to claim 1, wherein the weight ratio of the first monomer to the third monomer is 100:50 to 100:1900.

5. The polymer according to claim 1, wherein the C 1-4 alkyl methacrylate comprises methyl methacrylate.

6. The polymer according to claim 1, wherein the itaconic acid di-C 2-4 alkyl ester includes dibutyl itaconate.

7. The polymer according to claim 1, wherein the C 9-12 alkyl acrylate includes lauryl acrylate.

8. A coating, comprising: 100 parts by weight of the polymer according to claim 1; and 100 to 700 parts by weight of water.

9. The coating according to claim 8, further comprising 0.1 to 200 parts by weight of a pigment powder.

10. The coating according to claim 8, further comprising 0.1 to 20 parts by weight of a film-forming agent, defoaming agent, dispersant, leveling agent, or a combination of the above.