A dextrin-modified interior wall coating and its preparation method

Abstract

The present invention relates to a dextrin-modified interior wall coating and a preparation method thereof. The present invention provides a dextrin-modified interior wall coating which comprises 35-36 parts by weight of water, 0.2-0.3 part of defoamer, 1.2-1.4 parts of film-forming aid, 0.5-0.6 part of thickener, 30-32 parts of filler and 20-25 parts of bio-based emulsion. The dextrin-modified interior wall coating provided by the present invention has good stability and can be stored for a long time, and has the effect of preventing mildew and sterilizing.

Description

Technical Field

[0001] The present invention belongs to the field of coatings, and particularly relates to a dextrin-modified interior wall coating and a preparation method thereof. Background Art

[0002] Dextrin is a common polysaccharide food raw material, which is a low-conversion product between starch and starch sugar; in addition, it is also a water-soluble high-molecular compound, which can significantly reduce the surface tension of liquids and maintain the original rheological properties of liquids, thereby improving the stability of liquids. Therefore, it has a wide range of applications in the fields of food, medicine, and materials.

[0003] Interior wall coatings are a type of coatings used for interior wall decoration and protection. They can not only beautify the interior environment but also protect the wall from damage such as moisture and stains. With the development of science and technology and the improvement of living standards, more and more interior scenes require the application of coatings to achieve the characteristics of pursuing beauty, heat preservation, and moisture isolation. With the development of architectural design concepts, interior wall coatings also pay more attention to environmental protection and intelligence. Through the application of intelligent coatings and nanotechnology, interior wall coatings will have functions such as self-cleaning, intelligent color change, and energy storage, meeting the needs of future smart homes and sustainable buildings.

[0004] With the development of the construction industry, people's requirements for the living environment are also increasing day by day. In life scenarios, elderly users and people with special immune deficiencies need a special sterile living environment. Therefore, it is particularly necessary to develop an interior wall coating with good stability, long-term preservation, and mildew and bacteria prevention effects. Summary of the Invention

[0005] The present invention aims to overcome the above-mentioned defects in the prior art and provides a dextrin-modified interior wall coating and a preparation method thereof. The interior wall coating provided by the present invention has good stability, can be stored for a long time, and has mildew and bacteria prevention effects.

[0006] The present invention provides the following technical solutions to solve the above technical problems.

[0007] The present invention provides a dextrin-modified interior wall coating, which contains 32-38 parts by weight of water, 0.1-0.3 part of defoamer, 1.0-1.5 parts of film-forming aid, 0.5-0.6 part of thickener, 30-32 parts of filler, and 20-25 parts of bio-based emulsion. The bio-based emulsion is prepared by the following steps:

[0008] (1) Mix component A with a solvent (such as water) to obtain a modified dextrin emulsion, wherein component A contains an alkali (such as sodium bicarbonate), dextrin, epichlorohydrin, and an emulsifier (such as dodecylphenol polyether and / or sodium dodecyl diphenyl ether disulfonate);

[0009] (2) Mix component B with a solvent (such as water) to obtain an alkenyl monomer emulsion; wherein component B contains an emulsifier (such as dodecylphenol polyether and / or sodium dodecyl diphenyl ether disulfonate), methacrylamide, butyl acrylate, styrene, and methacrylic acid;

[0010] (3) Mix the alkenyl monomer emulsion, the modified dextrin emulsion, and an initiator (such as ammonium persulfate) to carry out an emulsion polymerization reaction;

[0011] (4) After the emulsion polymerization reaction is completed, add 2-amino-2-methyl-1-propanol to adjust the pH range of the reaction system to be between 4 and 5, then add tert-butyl hydroperoxide and FF-6M; then add 2-amino-2-methyl-1-propanol again so that the pH range is between 5.5 and 6.5 to obtain the bio-based emulsion.

[0012] In the present invention, in step (3), the steps of the emulsion polymerization reaction are preferably: under the condition of an initiator (such as ammonium persulfate), drop 1 / 2 portion of the alkenyl monomer emulsion into the modified dextrin emulsion to carry out an emulsion polymerization reaction, and then fully mix the remaining 1 / 2 portion of the alkenyl monomer emulsion with vinyltrimethoxysilane and then drop it into the modified dextrin emulsion to carry out an emulsion polymerization reaction.

[0013] In the present invention, component A further contains 2,3-epoxypropyltrimethylammonium chloride.

[0014] In the present invention, in component A, the mass ratio of the dextrin to 2,3-epoxypropyltrimethylammonium chloride is 25:3.

[0015] In the present invention, the defoaming agent is a conventional polyether defoaming agent in the art, such as BYK-012.

[0016] In the present invention, the thickening agent is a conventional alkali-swellable thickening agent in the art, such as TT615.

[0017] In the present invention, the film-forming aid is a conventional film-forming aid in the art, such as YT-12.

[0018] In the present invention, the filler is composed of titanium dioxide, kaolin, and talc powder mixed in a mass ratio of 3:20:20.

[0019] In the present invention, the dextrin-modified interior wall paint may further contain a mildew-proof agent, such as a benzisothiazoline compound, preferably 1,2-benzisothiazolin-3-one.

[0020] In the present invention, the dextrin-modified interior wall paint contains 0.2 - 0.4 parts of the mildew-proof agent.

[0021] The present invention provides a method for preparing an interior wall coating, and the preparation method is the same as the preparation method of the above-mentioned dextrin-modified interior wall coating.

[0022] The present invention also provides the use of the above-mentioned dextrin-modified interior wall coating as a coating.

[0023] The present invention also provides a bio-based emulsion, and the bio-based emulsion is as defined above.

[0024] On the basis of conforming to the common knowledge in the art, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0025] The reagents and raw materials used in the present invention are all commercially available.

[0026] The positive and progressive effects of the present invention are as follows: The dextrin-modified interior wall coating provided by the present invention has good stability and can be stored for a long time, and has a mildew-proof and antibacterial effect. Detailed Embodiments

[0027] The present invention will be further illustrated by the following examples, but the present invention is not limited to the scope of the examples. The experimental methods without specific conditions in the following examples are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0028] Example 1

[0029] Step 1: Preparation of the bio-based emulsion:

[0030] The formula of the bio-based emulsion is shown in Table 1.

[0031] Table 1

[0032]

[0033]

[0034] Step 1.1: Preparation of the modified dextrin emulsion

[0035] Referring to the materials and dosages in Table 1: Add deionized water to a 500 ml three-necked flask, add dextrin with stirring, and keep it at 80 °C for 30 min. Then, successively add aqueous solutions of sodium bicarbonate, epichlorohydrin, dodecyl diphenyl ether disulfonate, and dodecylphenol polyether, and keep it at 80 °C for 1 h; thus, a modified dextrin emulsion is obtained.

[0036] Step 1.2: Emulsion polymerization reaction of vinyl monomers

[0037] Refer to the materials and dosages in Table 1: Add water, sodium dodecyl diphenyl ether disulfonate, dodecylphenol polyether, and methacrylamide into a 500 ml three-necked flask, stir and mix for 10 min, then add butyl acrylate, styrene, and methacrylic acid, and quickly stir for 20 min to obtain an emulsion of vinyl monomers.

[0038] Then divide the above emulsion of vinyl monomers into two equal parts, where: one part does not add vinyltrimethoxysilane; the other part adds vinyltrimethoxysilane to obtain an emulsion of vinyl monomers containing vinyltrimethoxysilane.

[0039] Drop the emulsion of vinyl monomers without vinyltrimethoxysilane into the above modified dextrin emulsion (finish dropping in 2 h). Among them, 0.5 h after the emulsion of vinyl monomers without vinyltrimethoxysilane starts to be dropped, start dropping ammonium persulfate solution synchronously (the dropping rate is 2.5 ml / h, finish dropping in 4 h); then drop the emulsion of vinyl monomers containing vinyltrimethoxysilane into the reaction solution, finish dropping in 2 h; after dropping, continue to stir at 80 °C for 1 h to make the vinyl monomers fully undergo emulsion polymerization reaction.

[0040] Step 1.3: Remove the residual vinyl monomers in the emulsion

[0041] Refer to the materials and dosages in Table 1: Cool down the above reaction system to 55 °C, add 2-amino-2-methyl-1-propanol (AMP-95) to adjust the pH range between 4 and 5, then dissolve tert-butyl hydroperoxide and FF-6M in water respectively, and drop them synchronously, finish dropping in 1 h, and further keep the temperature for reaction for 0.5 h to fully remove the residual vinyl monomers. Then cool down the reaction system to below 40 °C, add 2-amino-2-methyl-1-propanol (AMP-95) to further adjust the pH to about 6 to obtain the bio-based emulsion.

[0042] Step Two: Preparation of dextrin-modified interior wall paint

[0043] By weight: Mix 35 parts of water, 0.2 part of polyether defoamer BYK-012, 1.3 parts of film-forming aid YT-12, and 0.5 part of thickener TT615, add 30 parts of filler and grind until the fineness of the slurry is less than 50 μm, then add 22 parts of the above bio-based emulsion and 0.3 part of mildew-proof agent 1,2-benzisothiazolin-3-one to obtain the dextrin-modified interior wall paint, where the filler is a mixture of titanium dioxide, kaolin, and talc in a mass ratio of 3:20:20 to obtain the dextrin-modified interior wall paint.

[0044] Example 2

[0045] Except for step 1.1 of Example 1, refer to the preparation method of Example 1. Specifically, the operation of step 1.1 of Example 2 is as follows:

[0046] Refer to the materials and dosages in Table 1: Add deionized water to a 500 ml three-necked flask, and add dextrin and 2,3-epoxypropyltrimethylammonium chloride (3 g) with stirring. Keep it at 80 °C for 30 min.

[0047] Then add the aqueous solutions of sodium bicarbonate, epichlorohydrin, dodecyl diphenyl ether disulfonate and dodecylphenol polyether in sequence, keep it at 80 °C for 1 h, then dropwise add ammonium persulfate solution (at a rate of 100 ml / h), and continue to react for 10 min after adding; thus, a modified dextrin emulsion is obtained.

[0048] Example 3

[0049] Except for step two of Example 2, refer to the preparation method of Example 2. Specifically, no mildew preventive is added in step two of Example 3.

[0050] Example 4

[0051] Except for step 1.2 of Example 1, refer to the preparation method of Example 1. Specifically, the operation of step 1.2 of Example 4 is as follows:

[0052] Refer to the materials and dosages in Table 1: Add water, dodecyl diphenyl ether disulfonate, dodecylphenol polyether, and methacrylamide to a 500 ml three-necked flask, stir and mix for 10 min, then add butyl acrylate, styrene, methacrylic acid and vinyltrimethoxysilane, and stir rapidly for 20 min to obtain an olefin monomer emulsion.

[0053] Then drop the olefin monomer emulsion into the above-mentioned modified dextrin emulsion. Among them, after 0.5 h of dropping, then start to drop the ammonium persulfate solution synchronously; after dropping, continue to stir at 80 °C for 1 h to make the olefin monomer fully undergo emulsion polymerization reaction.

[0054] Comparative Example 1

[0055] Except for step 1.1 of Example 1, refer to the preparation method of Example 1. Specifically, Comparative Example 1 does not include step 1.1.

[0056] Comparative Example 2

[0057] Except for step two of Example 1, refer to the preparation method of Example 1. Specifically, no mildew preventive is added in step two of Comparative Example 2.

[0058] Effect Example 1

[0059] Freeze-thaw stability: Freeze-thaw cycle: Referring to GB9268-2008, the bio-based emulsion prepared in each example or comparative example was placed in a glass bottle, sealed, and placed at (-10±2)°C for 18 h, then placed at room temperature for 6 h, and after sufficient stirring, the state of the emulsion was observed. If no aggregates appeared, the above freeze-thaw cycle was repeated until aggregates appeared. Each time a freeze-thaw cycle was passed, the number of freeze-thaw cycles increased by 1, and the result was expressed as a number.

[0060] Calcium ion stability (calcium stability): Referring to GB / T20623-2006, the bio-based emulsion prepared in each example or comparative example and a CaCl2 solution with a mass fraction of 1-3% were added to a beaker according to a weight ratio of 5:1, stirred evenly, placed in a 50 mL stoppered graduated cylinder, and after standing for 48 h, it was observed whether there were phenomena such as stratification, precipitation, and flocculation. If any existed, the result was considered to be unqualified.

[0061] The bio-based emulsions prepared in Examples 1-4 and Comparative Examples 1-2 were subjected to the above freeze-thaw stability and calcium ion stability tests, and the test results are shown in Table 2.

[0062] Table 2

[0063]

[0064] According to Table 2, the difference between the bio-based emulsion of Comparative Example 1 and that of Example 1 is that the bio-based emulsion of Comparative Example 1 does not contain modified dextrin components. However, the number of freeze-thaw cycles and the effect of calcium ion stability are far inferior to those of Example 1. Thus, it can be seen that modified dextrin has a significant stabilizing effect on the bio-based emulsion.

[0065] In addition, according to Table 2, the difference between the bio-based emulsions of Example 1 and Example 4 is that their preparation methods during emulsion polymerization are different. However, the bio-based emulsion of Example 1 has better stability. Thus, it can be seen that the preparation method of the emulsion polymerization reaction has an important influence on the stability of the finally prepared bio-based emulsion.

[0066] Effect test example 2

[0067] Antibacterial property test: Tested according to the requirements of the standard GB / T21866-2008. An antibacterial rate of 90-100% is represented by A, an antibacterial rate of 50-90% is represented by B, and an antibacterial rate of 0-50% is represented by C.

[0068] Anti-mildew performance test: Test strains: Aspergillus niger AS3.4463, Aspergillus terreus AS3.3935. Test method: Place the mildew under the conditions of 90% RH humidity and 28 °C temperature within 15 days. Evaluation criteria: Grade 1: No growth, that is, no growth is observed under a microscope (magnification 50 times); Grade 2: Trace growth, that is, growth is visible to the naked eye, but the growth coverage area is less than 10%; Grade 3: Growth coverage area is greater than 10%.

[0069] Preparation of test materials: Coat and cure the dextrin-modified interior wall coatings of Examples 1-4 and Comparative Examples 1-2 on a glass substrate respectively to form a coating film with a thickness of 10-15 μm and a coating film area of 0.04 m 2 ; The corresponding test materials are prepared.

[0070] Carry out the above anti-bacterial performance test and anti-mildew performance test on the dextrin-modified interior wall coatings prepared in Examples 1-4 and Comparative Examples 1-2 respectively. The experimental results are shown in Table 3.

[0071] Table 3

[0072]

[0073] As can be seen from Table 3 above, the dextrin-modified interior wall coating provided by the present invention has excellent anti-mildew effects. Especially for Example 3, although no mildew-proof agent is added, it still has excellent mildew-proof effects. This may be because 2,3-epoxypropyltrimethylammonium chloride reacts with dextrin to form dextrin quaternary ammonium salt, which itself has excellent anti-mildew and antibacterial properties. Moreover, the dextrin-modified interior wall coating provided by the present invention also has excellent anti-bacterial effects.

Claims

1. A dextrin-modified interior wall paint, characterized in that, It contains 32 - 38 parts by weight of water, 0.1 - 0.3 parts of defoamer, 1.0 - 1.5 parts of film-forming aid, 0.5 - 0.6 parts of thickener, 30 - 32 parts of filler and 20 - 25 parts of bio-based emulsion. The bio-based emulsion is prepared by the following steps: (1) Mix component A with water to obtain a modified dextrin emulsion, where component A contains sodium bicarbonate, dextrin, epichlorohydrin, dodecylphenol polyether and dodecyl diphenyl ether disulfonate; Component A further contains 2,3-epoxypropyltrimethylammonium chloride; (2) Mix component B with water to obtain an alkenyl monomer emulsion; where component B contains dodecylphenol polyether, dodecyl diphenyl ether disulfonate, methacrylamide, butyl acrylate, styrene and methacrylic acid; (3) Mix the alkenyl monomer emulsion, the modified dextrin emulsion with ammonium persulfate to carry out an emulsion polymerization reaction; (4) After the emulsion polymerization reaction is completed, add 2-amino-2-methyl-1-propanol to adjust the pH range of the reaction system between 4 - 5, then add tert-butyl hydroperoxide and FF-6M; then add 2-amino-2-methyl-1-propanol again to adjust the pH range between 5.5 - 6.5 to obtain the bio-based emulsion; Among them, in step (3), the steps of the emulsion polymerization reaction are: under the catalysis of ammonium persulfate, add 1 / 2 portion of the alkenyl monomer emulsion obtained in step (2) dropwise into the modified dextrin emulsion for emulsion polymerization reaction, and then fully mix the remaining 1 / 2 portion of the alkenyl monomer emulsion with vinyltrimethoxysilane and then drop it into the reaction system for emulsion polymerization reaction.

2. The dextrin-modified interior wall paint according to claim 1, wherein, In component A, the mass ratio of dextrin to 2,3-epoxypropyltrimethylammonium chloride is 25:

3.

3. The dextrin-modified interior wall coating according to claim 1, characterized in that, The defoamer is BYK-012.

4. The dextrin-modified interior wall paint according to claim 1, wherein The thickener is TT-615.

5. The dextrin-modified interior wall coating according to claim 1, wherein The film-forming aid is YT-12.

6. The dextrin-modified interior wall coating according to claim 1, wherein The filler is composed of titanium dioxide, kaolin and talc powder mixed in a mass ratio of 3:20:

20.

7. The dextrin-modified interior wall paint according to claim 1, characterized in that, The modified interior wall coating with dextrin further contains a mildew-proof agent, and the mildew-proof agent is 1,2-benzisothiazolin-3-one.

8. A preparation method of an interior wall coating, characterized in that, It includes the following steps: mix 35 - 36 parts by weight of water, 0.2 - 0.3 parts of defoamer, 1.2 - 1.4 parts of film-forming aid, 0.5 - 0.6 parts of thickener, 30 - 32 parts of filler and 20 - 25 parts of bio-based emulsion by weight. The bio-based emulsion is prepared by the following steps: (1) Mix component A with water to obtain a modified dextrin emulsion, where component A contains sodium bicarbonate, dextrin, epichlorohydrin, dodecylphenol polyether and dodecyl diphenyl ether disulfonate; Component A further contains 2,3-epoxypropyltrimethylammonium chloride; (2) Mix component B with water to obtain an alkenyl monomer emulsion; where component B contains dodecylphenol polyether, dodecyl diphenyl ether disulfonate, methacrylamide, butyl acrylate, styrene and methacrylic acid; (3) Mix the alkenyl monomer emulsion, the modified dextrin emulsion with ammonium persulfate to carry out an emulsion polymerization reaction; (4) After the emulsion polymerization reaction is completed, 2-amino-2-methyl-1-propanol is added to adjust the pH range of the reaction system to be between 4 and 5, and then tert-butyl hydroperoxide and FF-6M are added; then 2-amino-2-methyl-1-propanol is added again to adjust the pH range to be between 5.5 and 6.5 to obtain the bio-based emulsion; Among them, in step (3), the steps of the emulsion polymerization reaction are as follows: under the catalysis of ammonium persulfate, 1 / 2 portion of the vinyl monomer emulsion obtained in step (2) is added dropwise to the modified dextrin emulsion for emulsion polymerization reaction, and then the remaining 1 / 2 portion of the vinyl monomer emulsion is fully mixed with vinyltrimethoxysilane and then added dropwise to the reaction system for emulsion polymerization reaction.

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