A process for the preparation of a low temperature curable orange peel effect anodic electrophoretic paint

Abstract

The application discloses a preparation method of low-temperature curing orange effect anion electrophoretic paint, and comprises the following steps: S1, preparing a macromolecular main resin; S2, preparing a functional auxiliary resin; S3, mixing the macromolecular main resin in the step S1 with the functional auxiliary resin in the step S2 to prepare an emulsion; S4, preparing a grinding resin; S5, grinding a color paste based on the grinding resin in the step S4; and S6, mixing the emulsion prepared in the step S3 with the color paste prepared in the step S5 and pure water according to a weight ratio of 3:1:6, so as to obtain the low-temperature curing orange effect anion electrophoretic paint. The coating has a stable orange effect, high hardness, good impact resistance and good weather resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water-based paint preparation, and particularly relates to a preparation method of low-temperature-curable orange peel effect anion electrophoretic paint. BACKGROUND

[0002] Traditional requirements of customers for paint are smooth and flat paint film. With the development of the times, different aesthetic requirements gradually appear. Orange peel paint has good decorative properties due to the regular concave-convex patterns on the surface, and has been widely used in the coating of housings of sewing machines, electric control cabinets and small motors. At present, the main implementation method of orange peel paint construction is spraying, which is very dependent on the use of orange peel additives. Slight deviation of the construction process leads to great differences in orange peel effect, and the orange peel effect is unstable. Similarly, the orange peel paint on the market is high-temperature baking and curing, which is inconsistent with the increasingly stringent environmental protection requirements. SUMMARY

[0003] The purpose of the present application is to provide a preparation method of low-temperature-curable orange peel effect anion electrophoretic paint, which solves one or more of the above-mentioned problems in the prior art.

[0004] In one aspect, the present application provides a preparation method of low-temperature-curable orange peel effect anion electrophoretic paint, which comprises the following steps:

[0005] S1, preparing a macromolecular main resin;

[0006] S2, preparing a functional auxiliary resin;

[0007] S3, mixing the macromolecular main resin in step S1 and the functional auxiliary resin in step S2 to prepare an emulsion;

[0008] S4, preparing a grinding resin;

[0009] S5, grinding color paste based on the grinding resin in step S4;

[0010] S6, mixing the emulsion prepared in step S3, the color paste prepared in step S5 and pure water in a weight ratio of 3:1:6, i.e. preparing a low-temperature-curable orange peel effect anion electrophoretic paint.

[0011] In some embodiments, the macromolecular main resin in step S1 comprises the following components by weight fraction:

[0012]

[0013]

[0014] In some embodiments, the preparation method of the macromolecular main resin in step S1 is as follows:

[0015] The formula amount of acrylic acid, methyl methacrylate, hydroxyethyl methacrylate, n-butyl acrylate, cyclohexyl methacrylate, trimethylolpropane triacrylate, azobisdimethylvaleronitrile, butanone is mixed to obtain mixed solution A;

[0016] The formula amount of isopropyl alcohol is added to a four-necked flask and heated to 90-95℃;

[0017] The mixed solution A of step is uniformly added into the four-necked flask by dropwise pump for 3 hours, and after the dropwise addition is completed, the temperature is maintained for 1 hour, thereby obtaining the macromolecular main resin.

[0018] In some embodiments, the functional auxiliary resin in step S2 comprises the following components by weight fraction:

[0019]

[0020] In some embodiments, the preparation method of the functional auxiliary resin in step S2 is as follows:

[0021] The formula amount of acrylic acid, methoxy polyethylene glycol (400) monoacrylate, FA2D, lauryl acrylate, azobisdimethylvaleronitrile, butanone is mixed to obtain mixed solution B;

[0022] The formula amount of isopropyl alcohol is added to a four-necked flask and heated to 90-95℃;

[0023] The mixed solution B is uniformly added into the four-necked flask by dropwise pump for 3 hours, and after the dropwise addition is completed, the temperature is maintained for 1 hour, thereby obtaining the functional auxiliary resin.

[0024] In some embodiments, the emulsion in step S3 comprises the following components by weight fraction:

[0025]

[0026]

[0027] In some embodiments, the preparation method of the emulsion in step S3 is as follows:

[0028] The formula amount of main resin, functional auxiliary resin and amino resin is sequentially added, and heated to 40-50℃ and stirred for 30 minutes, then the neutralizer is added and neutralized for 30 minutes, then pure water is added for dilution, and the stirring is continued for 30 minutes, thereby obtaining the emulsion.

[0029] In some embodiments, the grinding resin in step S4 comprises the following components by weight fraction:

[0030]

[0031] In some embodiments, the preparation method of the grinding resin in step S4 is as follows:

[0032] The formula amount of acrylic acid, methyl methacrylate, hydroxyethyl methacrylate, n-butyl acrylate, styrene, methoxy polyethylene glycol (400) monoacrylate, and benzoyl peroxide are mixed to obtain a mixed solution C;

[0033] The formula amount of ethylene glycol butyl ether is added to a four-necked flask and heated to 105-115°C, and the mixed solution C is uniformly added into the four-necked flask through a dropwise pump for 3 hours, and then the heating is continued for 1 hour, so that the grinding resin is prepared.

[0034] In some embodiments, the color paste in step S5 comprises the following components in parts by weight:

[0035]

[0036] The preparation method of the color paste in step S5 is as follows:

[0037] The formula amount of the grinding resin and the neutralizing agent are added into a sand mill tank, stirred for 30 minutes, and then pure water is added for further dispersion for 5-10 minutes, and then the carbon black and kaolin are sequentially added and uniformly dispersed, and then sand milling is performed for 1 hour until the fineness is less than 10 μm.

[0038] In some embodiments, the preparation method of step S6 is as follows:

[0039] The emulsion prepared in step S3, the color paste prepared in step S5, and pure water are sequentially added into a tank, and then the circulation stirring is started for 1 hour, so that the low-temperature curable orange peel effect anionic electrophoretic paint is prepared.

[0040] The present application has the following beneficial effects:

[0041] 1. The coating of the present application is realized by the electrophoretic coating process, and since the components of the electrophoretic tank liquid are stable, the final paint film has a continuously stable orange peel effect, which is different from the spraying process which relies on an orange peel aid;

[0042] 2. The macromolecular main resin of the present application uses trimethylolpropane triacrylate crosslinking monomer, uses high-TG acrylate monomer, and improves the hardness of the main resin. The functional auxiliary resin is combined by using a low-TG monomer with good flexibility, which improves the impact resistance of the paint film. The macromolecular main resin and the toughening auxiliary resin are used in combination, and due to the difference in surface tension during the film forming rate and the baking process, the orange peel effect is presented, and the balance of high hardness and impact resistance of the paint film is achieved;

[0043] 3. The present application uses a low-temperature curing amino resin crosslinking agent, so that the product of the present application has high cost performance, low-temperature baking and curing, low carbon environmental protection, and greatly reduces the use cost of customers. DETAILED DESCRIPTION

[0044] The application will be further described in detail by embodiments.

[0045] Example 1

[0046] A low-temperature-curable orange effect anion electrophoretic paint is prepared by the following preparation method:

[0047] S1, preparing a macromolecular main resin:

[0048] According to the weight fraction, 42 parts of acrylic acid, 10 parts of methyl methacrylate, 10 parts of hydroxyethyl methacrylate, 6 parts of n-butyl acrylate, 7 parts of cyclohexyl methacrylate, 2 parts of trimethylolpropane triacrylate, 2 parts of azobis isobutyronitrile, and 2 parts of butanone are mixed to obtain a mixed solution A;

[0049] 7 parts of isopropyl alcohol are added to a four-necked flask and heated to 90-95°C;

[0050] The mixed solution A in step is uniformly added into the four-necked flask by a dropwise pump for 3 hours, and after the addition is completed, the temperature is kept for 1 hour, and the macromolecular main resin is prepared;

[0051] S2, preparing a functional auxiliary resin:

[0052] According to the weight fraction, 7 parts of acrylic acid, 13 parts of methoxy polyethylene glycol (400) monoacrylate, 8 parts of FA2D, 14 parts of lauryl acrylate, 2 parts of azobis isobutyronitrile, and 2 parts of butanone are mixed to obtain a mixed solution B;

[0053] 18 parts of isopropyl alcohol are added to a four-necked flask and heated to 90-95°C;

[0054] The mixed solution B is uniformly added into the four-necked flask by a dropwise pump for 3 hours, and after the addition is completed, the temperature is kept for 1 hour, and the functional auxiliary resin is prepared;

[0055] S3, mixing the macromolecular main resin in step S1 with the functional auxiliary resin in step S2 to prepare an emulsion:

[0056] The preparation method of the emulsion in step S3 is:

[0057] 30 parts of the main resin, 8 parts of the functional auxiliary resin, and 15 parts of the amino resin are sequentially added and heated to 40°C for stirring for 30 minutes, 2.5 parts of a neutralizing agent are further added and neutralized for 30 minutes, 44.5 parts of pure water are added for dilution after the neutralization is completed, and the stirring is continued for 30 minutes, and the emulsion is prepared;

[0058] S4, preparing a grinding resin:

[0059] 7 parts of acrylic acid, 10 parts of methyl methacrylate, 10 parts of hydroxyethyl methacrylate, 6 parts of n-butyl acrylate, 7 parts of styrene, 3 parts of methoxy polyethylene glycol (400) monoacrylate, 5 parts of benzoyl peroxide are mixed to obtain a mixed solution C;

[0060] 25 parts of ethylene glycol butyl ether are added to a four-necked flask and heated to 105°C, and the mixed solution C is uniformly added into the four-necked flask through a dropping pump at a constant speed for 3 hours. After the addition is completed, the temperature is maintained for 1 hour to obtain the grinding resin;

[0061] S5, grinding the color paste based on the grinding resin in step S4:

[0062] 15 parts of the grinding resin and 1 part of the neutralizing agent are added to a sand mill tank, stirred for 30 minutes, 30 parts of pure water are added for further dispersion for 5 minutes, and then 4 parts of carbon black and 30 parts of kaolin are added in sequence and uniformly dispersed, and then sand milling is performed for 1 hour until the fineness is less than 10 μm;

[0063] S6, the emulsion prepared in step S3 is mixed with the color paste prepared in step S5 and pure water in a weight ratio of 3:1:6 to obtain a low-temperature-curable orange peel effect anionic electrophoretic paint.

[0064] Among them, the amino resin is preferably CYMEL 303LF, which can well balance the hardness and flexibility; the neutralizing agent is preferably diethanolamine, and the strong base neutralizing agent has better stability in the tank solution.

[0065] Example 2

[0066] A low-temperature-curable orange peel effect anionic electrophoretic paint is prepared by the following preparation method:

[0067] S1, preparing a macromolecular main resin:

[0068] According to the weight parts, 45 parts of acrylic acid, 12 parts of methyl methacrylate, 12 parts of hydroxyethyl methacrylate, 7 parts of n-butyl acrylate, 8 parts of cyclohexyl methacrylate, 2.5 parts of trimethylolpropane triacrylate, 2.5 parts of azobis isobutyronitrile, and 2.5 parts of butanone are mixed to obtain a mixed solution A;

[0069] 8 parts of isopropyl alcohol are added to a four-necked flask and heated to 92°C;

[0070] The mixed solution A in step is uniformly added into the four-necked flask through a dropping pump at a constant speed for 3 hours. After the addition is completed, the temperature is maintained for 1 hour to obtain the macromolecular main resin;

[0071] S2, preparing a functional auxiliary resin:

[0072] According to the weight parts, 8 parts of acrylic acid, 14 parts of methoxy polyethylene glycol (400) monoacrylate, 10 parts of FA2D, 16 parts of lauryl acrylate, 2.5 parts of azobis isobutyronitrile, 2.5 parts of butanone are mixed to obtain a mixed solution B;

[0073] 20 parts of isopropyl alcohol are added to a four-necked flask and heated to 93°C;

[0074] The mixed solution B is uniformly added into the four-necked flask through a dropwise pump for 3 hours, and after the addition is completed, the temperature is kept for 1 hour, and the functional auxiliary resin is prepared;

[0075] S3, the macromolecular main resin in step S1 is mixed with the functional auxiliary resin in step S2 to prepare an emulsion:

[0076] The preparation method of the emulsion in step S3 is:

[0077] 30 parts of the main resin, 8 parts of the functional auxiliary resin and 15 parts of the amino resin are sequentially added, and heated to 45°C for stirring for 30 minutes, 2.5 parts of a neutralizing agent are further added and neutralized for 30 minutes, 44.5 parts of pure water are added for dilution after the neutralization is completed, and the stirring is continued for 30 minutes, and the emulsion is prepared;

[0078] S4, grinding resin is prepared:

[0079] 78 parts of acrylic acid, 12 parts of methyl methacrylate, 12 parts of hydroxyethyl methacrylate, 7 parts of n-butyl acrylate, 8 parts of styrene, 3.5 parts of methoxy polyethylene glycol (400) monoacrylate, and 5.5 parts of benzoyl peroxide are mixed to obtain a mixed solution C;

[0080] 30 parts of ethylene glycol butyl ether are added to a four-necked flask and heated to 110°C, and the mixed solution C is uniformly added into the four-necked flask through a dropwise pump for 3 hours, and after the addition is completed, the temperature is kept for 1 hour, and the grinding resin is prepared;

[0081] S5, colorant grinding is carried out based on the grinding resin in step S4:

[0082] 20 parts of the grinding resin and 1 part of the neutralizing agent are added to a sand mill tank, stirred for 30 minutes, 32.5 parts of pure water are added for further dispersion for 7.5 minutes, 4.5 parts of carbon black and 32.5 parts of kaolin are sequentially added after the dispersion is completed, and the dispersion is uniform, and sand milling is carried out for 1 hour to a fineness of less than 10μm;

[0083] S6, the emulsion prepared in step S3 is mixed with the colorant prepared in step S5 and pure water in a weight ratio of 3:1:6, and a low-temperature curable orange peel effect anionic electrophoretic paint is prepared.

[0084] Wherein: the amino resin is preferably CYMEL 303LF, which can well balance the hardness and flexibility; the neutralizing agent is preferably diethanolamine, and the strong base neutralizing agent has better stability in the tank solution.

[0085] Example 3

[0086] A low-temperature-curable orange effect anionic electrophoretic paint, which is prepared by the following preparation method:

[0087] S1, preparing a macromolecular main resin:

[0088] According to the weight fraction, 48 parts of acrylic acid, 14 parts of methyl methacrylate, 14 parts of hydroxyethyl methacrylate, 8 parts of n-butyl acrylate, 9 parts of cyclohexyl methacrylate, 3 parts of trimethylolpropane triacrylate, 3 parts of azobisisobutyronitrile and 3 parts of butanone are mixed to obtain a mixed solution A;

[0089] 9 parts of isopropyl alcohol are added to a four-necked flask and heated to 95°C;

[0090] The mixed solution A in step is uniformly added into the four-necked flask by a dropwise pump for 3 hours, and after the addition is completed, the temperature is kept for 1 hour, and the macromolecular main resin is prepared;

[0091] S2, preparing a functional auxiliary resin:

[0092] According to the weight fraction, 9 parts of acrylic acid, 15 parts of methoxy polyethylene glycol (400) monoacrylate, 12 parts of FA2D, 18 parts of lauryl acrylate, 3 parts of azobisisobutyronitrile and 3 parts of butanone are mixed to obtain a mixed solution B;

[0093] 22 parts of isopropyl alcohol are added to a four-necked flask and heated to 95°C;

[0094] The mixed solution B is uniformly added into the four-necked flask by a dropwise pump for 3 hours, and after the addition is completed, the temperature is kept for 1 hour, and the functional auxiliary resin is prepared;

[0095] S3, mixing the macromolecular main resin in step S1 with the functional auxiliary resin in step S2 to prepare an emulsion:

[0096] The preparation method of the emulsion in step S3 is:

[0097] 30 parts of the main resin, 8 parts of the functional auxiliary resin and 15 parts of the amino resin are sequentially added and heated to 50°C for stirring for 30 minutes, 2.5 parts of the neutralizing agent is added and neutralized for 30 minutes, 44.5 parts of pure water is added for dilution after the neutralization is completed, and the stirring is continued for 30 minutes, and the emulsion is prepared;

[0098] S4, preparing a grinding resin:

[0099] Mix 9 parts of acrylic acid, 14 parts of methyl methacrylate, 14 parts of hydroxyethyl methacrylate, 8 parts of n-butyl acrylate, 9 parts of styrene, 4 parts of methoxypolyethylene glycol (400) monoacrylate, and 6 parts of benzoyl peroxide to obtain a mixed solution C;

[0100] Add 35 parts of ethylene glycol butyl ether into a four-necked flask and heat to 115°C. The mixed solution C is added into the four-necked flask at a uniform speed through a dropping pump for 3 hours. After the addition is completed, the temperature is maintained for 1 hour to obtain the grinding resin.

[0101] S5, grinding the color paste based on the grinding resin in step S4:

[0102] Add 25 parts of the grinding resin and 1 part of the neutralizing agent into a sand mill tank, stir for 30 minutes, add 35 parts of pure water and continue to disperse for 10 minutes. After the dispersion is completed, 5 parts of carbon black and 35 parts of kaolin are added in sequence and uniformly dispersed, and then sand milling is performed for 1 hour to obtain a fineness of less than 10 μm.

[0103] S6, mixing the emulsion prepared in step S3, the color paste prepared in step S5, and pure water in a weight ratio of 3:1:6 to obtain a low-temperature curable orange effect anionic electrophoretic paint.

[0104] In the formula, the amino resin is preferably CYMEL 303LF, which can well balance the hardness and flexibility; and the neutralizing agent is preferably diethanolamine, which has better stability in the tank solution.

[0105] Comparative Example 1

[0106] The commercially available anionic electrophoretic paint is generally prepared by copolymerization of acrylic acid or methacrylic acid and acrylate, and uses a blocked isocyanate curing agent as the crosslinking agent, and needs to be cured at 180°C for 20 minutes.

[0107] Performance test

[0108] The low-temperature curable orange effect anionic electrophoretic paint in Examples 1-3 is electrophoretically coated under conventional electrophoretic conditions, and baked at 140°C for 20 minutes to form an appearance orange effect paint on the outer surface of the workpiece. The commercially available anionic electrophoretic paint in Comparative Example 1 is electrophoretically coated under conventional electrophoretic conditions, and baked at 180°C for 20 minutes to form a smooth and flat coating film on the surface of the workpiece. The main technical indexes of the sample are as follows:

[0109] Table 1

[0110]

[0111]

[0112] In summary: the low temperature orange anion electrophoretic paint of the application has good storage stability, can be low temperature baked, meets high paint film hardness, and at the same time, the coating flexibility is 1mm, the impact strength is 50Kg / cm without rupture. The paint film has good weather resistance, and meets some workpiece requirements of outdoor use.

[0113] The above description is only the preferred mode of the present application, and it should be pointed out that for those skilled in the art, without departing from the inventive concept, a number of modifications and improvements can be made, which should be considered as within the scope of protection of the application.

Claims

1. A method for preparing a low-temperature curable anionic electrophoretic coating with an orange peel effect, characterized in that, Includes the following steps: S1. Preparation of macromolecular main resin; S2. Preparation of functional auxiliary resins; S3. Mix the macromolecular main resin in step S1 with the functional auxiliary resin in step S2 to prepare an emulsion. S4. Prepare the grinding resin; S5. Grind the color paste based on the grinding resin in step S4; S6. The emulsion obtained in step S3 is mixed with the color paste and pure water obtained in step S5 in a weight ratio of 3:1:6 to obtain an anionic electrophoretic coating with orange peel effect that can be cured at low temperature. Wherein: the macromolecular main resin includes the following components: isopropanol, acrylic acid, methyl methacrylate, hydroxyethyl methacrylate, n-butyl acrylate, cyclohexyl methacrylate, trimethylolpropane triacrylate, azobisisobutyronitrile, and methyl ethyl ketone; the functional auxiliary resin includes the following components: isopropanol, acrylic acid, methoxy polyethylene glycol (400) monoacrylate, FA2D monomer, lauryl acrylate, azobisisobutyronitrile, and methyl ethyl ketone.

2. The method for preparing a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 1, characterized in that, The macromolecular main resin in step S1 includes the following components by weight:

3. The method for preparing a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 2, characterized in that, The preparation method of the macromolecular main resin in step S1 is as follows: The prescribed amounts of acrylic acid, methyl methacrylate, hydroxyethyl methacrylate, n-butyl acrylate, cyclohexyl methacrylate, trimethylolpropane triacrylate, azobisisobutyronitrile, and butanone were added and mixed to obtain mixture A; Add the prescribed amount of isopropanol to a four-necked flask and heat to 90-95℃; The mixture A described in step A is added dropwise to a four-necked flask at a uniform rate over 3 hours using a dropper pump. After the addition is completed, the mixture is kept warm for another hour to obtain the macromolecular main resin.

4. The method for preparing a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 1, characterized in that, The functional auxiliary resin in step S2 includes the following components by weight:

5. The preparation method of a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 4, characterized in that, The preparation method of the functional auxiliary resin in step S2 is as follows: The prescribed amounts of acrylic acid, methoxy polyethylene glycol (400) monoacrylate, FA2D, lauryl acrylate, azobisisobutyronitrile, and methyl ethyl ketone were added and mixed to obtain mixture B; Add the prescribed amount of isopropanol to a four-necked flask and heat to 90-95℃; The mixture B is added dropwise into a four-necked flask at a constant rate over 3 hours using a dropper pump. After the addition is complete, the mixture is kept warm for another hour to obtain the functional auxiliary resin.

6. The method for preparing a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 1, characterized in that, The emulsion in step S3 comprises the following components by weight:

7. The method for preparing a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 6, characterized in that, The method for preparing the emulsion in step S3 is as follows: Add the main resin, functional auxiliary resin and amino resin in the formula amount in sequence, heat to 40-50℃ and stir for 30 minutes, then add neutralizing agent and neutralize for another 30 minutes. After neutralization, add pure water to dilute and continue stirring for 30 minutes to obtain the emulsion.

8. The method for preparing a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 1, characterized in that, The grinding resin in step S4 comprises the following components by weight:

9. The method for preparing a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 8, characterized in that, The method for preparing the grinding resin in step S4 is as follows: The prescribed amounts of acrylic acid, methyl methacrylate, hydroxyethyl methacrylate, n-butyl acrylate, styrene, methoxy polyethylene glycol (400) monoacrylate, and benzoyl peroxide were added and mixed to obtain mixture C; Add the prescribed amount of ethylene glycol butyl ether to a four-necked flask and heat it to 105-115°C. Add the mixture C to the four-necked flask at a uniform rate over 3 hours using a drop pump. After the addition is complete, continue to keep it at the temperature for 1 hour to obtain the grinding resin.

10. The method for preparing a low-temperature curable orange peel effect anionic electrophoretic coating according to claim 1, characterized in that, The color paste in step S5 comprises the following components by weight: The preparation method of the color paste in step S5 is as follows: Add the prescribed amount of grinding resin and neutralizer to the sand mill jar, stir for 30 minutes, add pure water and continue to disperse for 5-10 minutes. After dispersion, add carbon black and kaolin in sequence, disperse evenly, and sand mill for 1 hour until the fineness is less than 10μm.

Images