Composite spherical matting agent and preparation method thereof

Abstract

The invention discloses a composite spherical delustering agent and a preparation method thereof, and relates to the technical field of delustering agents. The composite spherical matting agent is prepared from, by weight, 50-80 parts of composite spherical resin, 2-5 parts of polyamide anti-settling wax, 5-10 parts of naphthenic white oil, 1-5 parts of filler, 1-5 parts of antioxidant and 30-50 parts of solvent, and raw materials of the composite spherical resin comprise polyester resin and ethylene resin. After the composite spherical matting agent is applied to a coating, the transparency of the coating is not obviously influenced, and the composite spherical matting agent has high weather resistance.

Description

Technical Field

[0001] The invention relates to the field of matting agents, in particular to a composite spherical matting agent and a preparation method thereof. Background Art

[0002] In the field of coatings and materials, matting agents are widely used. Their main function is to reduce the glossiness of the material surface to meet specific visual effects or functional requirements. However, traditional matting agents have some obvious shortcomings in practical applications.

[0003] On the one hand, many matting agents have low transparency, which is mainly due to the uneven distribution of matting agent particles in the coating, or the large difference between the refractive index of the matting agent itself and the refractive index of the coating matrix, which causes light to scatter at the interface, thus significantly affecting the transparency of the coating. For example, ordinary physical and chemical matting agents have poor compatibility in epoxy and polyester, which easily leads to whitening of transparent powder and poor transparency. In practical applications, it is necessary to balance transparency and matting properties, and select appropriate components and proportions by optimizing the formula and process to achieve the purpose of satisfying the matting effect while maintaining the transparency of the coating as much as possible.

[0004] On the other hand, some matting agents have poor weather resistance. This is mainly because the organic components in the matting agents are easily affected by ultraviolet rays, temperature changes and other factors when exposed to the natural environment for a long time, causing degradation or discoloration, thus affecting the appearance and performance of the coating. For example, when some matting agents are used outdoors, they contain catalysts, curing agents, etc., which can easily cause the coating to turn yellow and affect transparency.

[0005] Therefore, there is currently a lack of a matting agent that does not significantly affect the transparency of the coating after being applied to the coating and has high weather resistance. Summary of the invention

[0006] The present invention is made in view of the above-mentioned problems and provides a composite spherical matting agent and a preparation method thereof.

[0007] The first aspect of the present invention provides a composite spherical matting agent, which comprises, by weight, 50 to 80 parts of a composite spherical resin, 2 to 5 parts of a polyamide anti-settling wax, 5 to 10 parts of cycloalkane white oil, 1 to 5 parts of a filler, 1 to 5 parts of an antioxidant, and 30 to 50 parts of a solvent, wherein the raw materials of the composite spherical resin comprise polyester resin and ethylene resin.

[0008] In some embodiments of the present invention, the polyester resin includes polyethylene terephthalate and / or polybutylene terephthalate, and the ethylene resin includes divinylbenzene and / or ethylene glycol di(meth)acrylate.

[0009] In some embodiments of the present invention, the weight ratio of the polyester resin to the ethylene resin is (3-5):1.

[0010] In some embodiments of the present invention, the average particle size of the composite spherical resin is 10 μm to 50 μm; and / or the viscosity of the composite spherical resin in a molten state at room temperature is less than or equal to 0.7 dl / g.

[0011] In some embodiments of the present invention, the filler includes nano-calcium carbonate and modified molybdenum disulfide in a weight ratio of (1-4):1.

[0012] In some embodiments of the present invention, the solvent includes at least one of methyl isobutyl ketone, cyclohexanone, n-butyl acetate, ethyl acetate, butyl acetate, tert-butyl alcohol, isobutyl alcohol, isopropyl alcohol, acetone, and anisole.

[0013] The second aspect of the present invention provides a method for preparing a composite spherical matting agent, comprising the following steps:

[0014] S1, melt the polyester resin, add the ethylene resin and continue to heat and stir to sphericalize the mixed particles, and then spray dry to obtain a composite spherical resin;

[0015] S2, adding a solvent and the composite spherical resin into a stirring tank, and then sequentially adding filler, naphthenic white oil, and polyamide anti-settling wax flakes, and dispersing at high speed to obtain a product to be post-treated;

[0016] S3, adding an antioxidant to the product to be post-treated, mixing, and aging to obtain a composite spherical matting agent.

[0017] In some embodiments of the present invention, in step S1, the temperature of the molten polyester resin is 220°C to 230°C; and / or the temperature of the heating and stirring is 300°C to 330°C.

[0018] In some embodiments of the present invention, in step S1, the stirring rate of the heating stirring is 800 rpm to 1200 rpm, and the stirring time is 1.5 to 2 hours.

[0019] In some embodiments of the present invention, in step S2, the atomization pressure of the spray drying is 0.8 MPa to 1.2 MPa.

[0020] The beneficial effects that can be achieved by the present invention are:

[0021] The invention provides a composite spherical matting agent, wherein the refractive index of the matting agent is adjusted by mixing resin, and the spherical structure is conducive to uniform scattering of light, and a low amount of filler added avoids introducing too many light scattering points, and the composite spherical matting agent can play a matting role in a coating without affecting the transparency of the coating. The composite spherical matting agent is applied to the coating without significantly affecting its transparency and having high weather resistance through overall resin composite refractive index regulation, nanofiller interface optimization and anti-oxidation-anti-precipitation synergistic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a scanning electron microscope image of a composite spherical matting agent according to one embodiment of the present invention, with a magnification of 1000 times.

[0023] The implementation, functional features and advantages of the present invention will be further described in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0024] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present invention, and are not intended to limit the subject matter described in the claims.

[0025] The "range" disclosed in the present invention is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present invention, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, wherein a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0026] If not otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form a new technical solution.

[0027] Unless otherwise specified, all technical features and optional technical features of the present invention can be combined with each other to form a new technical solution.

[0028] If not otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0029] In practical applications, matting agents are widely used in the field of coatings and materials. Their main function is to reduce the glossiness of the material surface to meet specific visual effects or functional requirements. It is necessary to balance transparency and matting properties, and to optimize the formula and process, select appropriate components and proportions to achieve the purpose of satisfying the matting effect while maintaining the transparency of the coating as much as possible. At present, there is a lack of a matting agent that does not significantly affect the transparency of the coating after being applied to the coating and has high weather resistance.

[0030] In view of this, the present invention proposes a composite spherical matting agent, which comprises, by weight, 50 to 80 parts of a composite spherical resin, 2 to 5 parts of a polyamide anti-settling wax, 5 to 10 parts of cycloalkane white oil, 1 to 5 parts of a filler, 1 to 5 parts of an antioxidant, and 30 to 50 parts of a solvent, wherein the raw materials of the composite spherical resin include polyester resin and ethylene resin.

[0031] In the composite spherical resin, polyester resin has a higher refractive index. After compounding with ethylene resin, by adjusting the ratio of the two, the refractive index can be matched with the coating substrate, reducing light scattering and improving the transparency of the coating. The coating substrate includes polycarbonate, polyacrylate, etc. The surface of the spherical particles is smooth, and the light is evenly diffused on the surface of the particles, reducing the interface scattering with the coating substrate, achieving a reduction in gloss without affecting the overall transparency of the coating. The ethylene resin provides flexibility and hydrolysis resistance, and synergistically inhibits the cracking of the coating with polyester.

[0032] Polyamide anti-settling wax is adsorbed on the surface of fillers and resin particles through hydrogen bonding to prevent sedimentation, ensure system uniformity, and avoid local turbidity. When the addition amount is ≤5 parts, it does not affect the viscosity of the system.

[0033] Naphthenic white oil has good compatibility with polyester / ethylene resins. As a plasticizer, it can lower the glass transition temperature, improve the low-temperature toughness of the matting agent, and reduce the volume shrinkage during the drying process of the coating. In addition, the naphthenic structure has strong oxidation resistance, inhibits the breakage of the resin chain, and avoids microcracks.

[0034] Antioxidants include hindered phenols and phosphites, such as Irganox 1010 and Irgafos 168.

[0035] The composite spherical matting agent of this scheme is mixed with resin to adjust the refractive index of the matting agent, and the spherical structure is conducive to uniform scattering of light. The low amount of filler added avoids the introduction of too many light scattering points. It can play a matting role when added to the coating without affecting the transparency of the coating. Overall, through the regulation of the composite refractive index of the resin, the optimization of the nanofiller interface and the antioxidant-anti-precipitation synergistic system, the composite spherical matting agent is used in the coating without significantly affecting its transparency and has high weather resistance.

[0036] In some embodiments, the polyester-based resin includes polyethylene terephthalate and / or polybutylene terephthalate, and the ethylene-based resin includes divinylbenzene and / or ethylene glycol di(meth)acrylate.

[0037] Ethylene terephthalate (PET) and / or polybutylene terephthalate (PBT) have good mechanical properties and thermal stability, which help to improve the weather resistance and adhesion of the matting agent. Divinylbenzene and / or ethylene glycol di(meth)acrylate can enhance the transparency and chemical resistance of the matting agent. The combination of the above resins not only provides a good matting effect, but also ensures the stability of the matting agent in different environments and reduces the impact on transparency.

[0038] In some embodiments, the weight ratio of the polyester resin to the ethylene resin is (3-5): 1. Preferably, the weight ratio is 3:1.

[0039] In some embodiments, the average particle size of the composite spherical resin is 10 μm to 50 μm; and / or the viscosity of the composite spherical resin in a molten state at room temperature is less than or equal to 0.7 dl / g.

[0040] In some embodiments, the filler includes nano-calcium carbonate and modified molybdenum disulfide in a weight ratio of (1-4):1. Preferably, the weight ratio is 2:1.

[0041] In some embodiments, the solvent includes at least one of methyl isobutyl ketone, cyclohexanone, n-butyl acetate, ethyl acetate, butyl acetate, tert-butyl alcohol, isobutyl alcohol, isopropyl alcohol, acetone, and anisole. Preferably, the solvent is methyl isobutyl ketone or n-butyl acetate, which can reduce the VOCs content and improve the environmental protection of the matting agent without affecting the performance of the matting agent.

[0042] The second aspect of the present invention provides a method for preparing a composite spherical matting agent, comprising the following steps:

[0043] S1, melt the polyester resin, add the ethylene resin and continue to heat and stir to spheroidize the mixed particles, and then spray dry to obtain a composite spherical resin. In some embodiments, in step S1, the temperature of the melted polyester resin is 220°C to 230°C; and / or the temperature of the heating and stirring is 300°C to 330°C. The stirring rate of the heating and stirring is 800rpm to 1200rpm, and the stirring time is 1.5 to 2 hours.

[0044] S2, adding solvent and the composite spherical resin into a stirring kettle, and then adding filler, naphthenic white oil, and polyamide anti-settling wax flakes in sequence, and dispersing at high speed to obtain a product to be post-treated. In some embodiments, the atomization pressure of the spray drying is 0.8MPa to 1.2MPa.

[0045] S3, adding an antioxidant to the product to be post-treated, mixing, and aging to obtain a composite spherical matting agent. In some embodiments, in step S3, the aging is standing for more than or equal to 24 hours.

[0046] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0047] Example 1

[0048] In parts by weight, 60 parts of raw polyethylene terephthalate particles are put into a dispersion tank, the temperature is raised to 230° C., and the mixture is stirred at 1000 rpm until completely melted. 20 parts of ethylene glycol di(meth)acrylate particles are slowly added, the temperature is maintained at 325° C., and the mixture is stirred for 1.5-2 hours. The viscosity is tested to be 0.6 dl / g using an IV3100R automatic viscometer. The product is taken out and spray-dried in a tower at an atomization pressure of 1.1 MPa. The product is observed under a scanning electron microscope to obtain a composite spherical resin having an average particle size of 10-50 μm.

[0049] Add 40 parts of n-butyl acetate and 65 parts of composite spherical resin microspheres into a planetary stirring kettle and stir for 40 minutes. Add 2 parts of nano calcium carbonate, 1 part of modified molybdenum disulfide and 6 parts of cycloalkane white oil in sequence. After heating to 70°C, add 3 parts of polyamide anti-settling wax flakes. After cooling to 50°C, add I-1010 antioxidant and let stand for 24 hours to mature to obtain a composite spherical matting agent.

[0050] Example 2

[0051] In parts by weight, 50 parts of raw polyethylene terephthalate particles are put into a dispersion tank, the temperature is raised to 230° C., and the mixture is stirred at 1000 rpm until completely melted. 10 parts of ethylene glycol di(meth)acrylate particles are slowly added, the temperature is maintained at 325° C., and the mixture is stirred for 1.5-2 hours. The viscosity is tested to be 0.6 dl / g using an IV3100R automatic viscometer. The product is taken out and spray-dried in a tower at an atomization pressure of 1.1 MPa. The product is observed under a scanning electron microscope to obtain a composite spherical resin having an average particle size of 10-50 μm.

[0052] Add 40 parts of n-butyl acetate and 55 parts of composite spherical resin microspheres into a planetary stirring kettle and stir for 40 minutes. Add 2 parts of nano calcium carbonate, 1 part of modified molybdenum disulfide and 6 parts of cycloalkane white oil in sequence. After heating to 70°C, add 3 parts of polyamide anti-settling wax flakes. After cooling to 50°C, add I-1010 antioxidant and let stand for 24 hours to mature to obtain a composite spherical matting agent.

[0053] Example 3

[0054] In parts by weight, 60 parts of raw material polyethylene terephthalate particles are put into a dispersion tank, the temperature is raised to 230°C, and the mixture is stirred at 1000 rpm until completely melted. 20 parts of divinylbenzene particles are slowly added, the temperature is maintained at 325°C, and the mixture is stirred for 1.5-2 hours. The viscosity is tested to be 0.6 dl / g using an IV3100R automatic viscometer. The product is taken out and spray-dried in a tower at an atomization pressure of 1.1 MPa. The product is observed under a scanning electron microscope to obtain a composite spherical resin having an average particle size of 10-50 μm.

[0055] Add 40 parts of n-butyl acetate and 75 parts of composite spherical resin microspheres into a planetary stirring kettle and stir for 40 minutes. Add 2 parts of nano calcium carbonate, 1 part of modified molybdenum disulfide and 6 parts of cycloalkane white oil in sequence. After heating to 70°C, add 3 parts of polyamide anti-settling wax flakes. After cooling to 50°C, add I-1010 antioxidant and let stand for 24 hours to mature to obtain a composite spherical matting agent.

[0056] Example 4

[0057] In parts by weight, 60 parts of raw polyethylene terephthalate particles are put into a dispersion tank, the temperature is raised to 230° C., and the mixture is stirred at 1000 rpm until completely melted. 20 parts of ethylene glycol di(meth)acrylate particles are slowly added, the temperature is maintained at 325° C., and the mixture is stirred for 1.5-2 hours. The viscosity is tested to be 0.6 dl / g using an IV3100R automatic viscometer. The product is taken out and spray-dried in a tower at an atomization pressure of 1.1 MPa. The product is observed under a scanning electron microscope to obtain a composite spherical resin having an average particle size of 10-50 μm.

[0058] Add 40 parts of n-butyl acetate and 65 parts of composite spherical resin microspheres into a planetary stirring kettle and stir for 40 minutes. Add 1 part of nano calcium carbonate, 1 part of modified molybdenum disulfide and 6 parts of cycloalkane white oil in sequence. After heating to 70°C, add 3 parts of polyamide anti-settling wax flakes. After cooling to 50°C, add I-1010 antioxidant and let stand for 24 hours to mature to obtain a composite spherical matting agent.

[0059] Comparative Example 1

[0060] Instead of preparing composite resin microspheres, polyethylene terephthalate was melt-spray dried to prepare single polyester resin microspheres. The rest was as in Example 1.

[0061] Comparative Example 2

[0062] Instead of preparing composite resin microspheres, ethylene glycol di(meth)acrylate was melt-spray dried to prepare single ethylene resin microspheres. The rest was as in Example 1.

[0063] Performance Test:

[0064] The composite spherical matting agent obtained in the examples and comparative examples was subjected to performance tests, and the test contents included:

[0065] 1. Matting agent transmittance: tested according to ASTM D1003 standard.

[0066] 2. Base material mixed light transmittance: 12% by weight of matting agent was added to a commercially available paint (Dulux GL038-3), and the light transmittance of the sample was tested according to ASTM D1003.

[0067] 3. Haze: Tested according to ASTM D1003 standard.

[0068] 4.QUV aging yellowing: tested according to ASTM G154 standard.

[0069] 5. Adhesion: Tested according to ASTM D3359 standard.

[0070] 6. Resistance to thermal shock: Keep the test sample at -30℃ for 10 minutes, heat it to 80℃ and keep it for 10 minutes, cycle the temperature down and up 10 times, perform the impact test according to ASTM D2794-2019, and observe the surface after 5 impacts.

[0071] The results are recorded in Table 1:

[0072] Table 1: Test results of Examples 1 to 4 and Comparative Examples 1 to 2

[0073]

[0074]

[0075] It can be seen that the composite spherical matting agent provided in this scheme has a refractive index that is adjusted by mixing the resin with the matting agent, and the spherical structure contributes to the uniform scattering of light. The low amount of filler added avoids the introduction of too many light scattering points. When added to the coating, it can play a matting role without affecting the transparency of the coating. Overall, through the regulation of the composite refractive index of the resin, the optimization of the interface of the nanofiller, and the antioxidant-anti-precipitation synergistic system, the composite spherical matting agent is used in the coating without significantly affecting its transparency and having high weather resistance.

[0076] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the main purpose of the present invention, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A composite spherical matting agent, characterized in that: In parts by weight, the composite spherical matting agent comprises: 50-80 parts of composite spherical resin, 2-5 parts of polyamide anti-settling wax, 5-10 parts of naphthenic white oil, 1 to 5 parts of filler, 1 to 5 parts of antioxidant, 30-50 parts of solvent, Wherein, the raw materials of the composite spherical resin include polyester resin and ethylene resin.

2. The composite spherical matting agent according to claim 1, characterized in that: The polyester resin includes polyethylene terephthalate and / or polybutylene terephthalate, and the ethylene resin includes divinylbenzene and / or ethylene glycol di(meth)acrylate.

3. The composite spherical matting agent according to claim 1, characterized in that: The weight ratio of the polyester resin to the ethylene resin is (3-5):

1.

4. The composite spherical matting agent according to claim 1, characterized in that: The average particle size of the composite spherical resin is 10 μm to 50 μm; And / or, the viscosity of the composite spherical resin in a molten state at room temperature is less than or equal to 0.7 dl / g.

5. The composite spherical matting agent according to claim 1, characterized in that: The filler comprises nano calcium carbonate and modified molybdenum disulfide in a weight ratio of (1-4):

1.

6. The composite spherical matting agent according to claim 1, characterized in that: The solvent includes at least one of methyl isobutyl ketone, cyclohexanone, n-butyl acetate, ethyl acetate, butyl acetate, tert-butyl alcohol, isobutyl alcohol, isopropyl alcohol, acetone and anisole.

7. A method for preparing the composite spherical matting agent according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, melt the polyester resin, add the ethylene resin and continue to heat and stir to sphericalize the mixed particles, and then spray dry to obtain a composite spherical resin; S2, adding a solvent and the composite spherical resin into a stirring tank, and then sequentially adding filler, naphthenic white oil, and polyamide anti-settling wax flakes, and dispersing at high speed to obtain a product to be post-treated; S3, adding an antioxidant to the product to be post-treated, mixing, and aging to obtain a composite spherical matting agent.

8. The method for preparing the composite spherical matting agent according to claim 7, characterized in that: In step S1, the temperature of the molten polyester resin is 220°C to 230°C; And / or, the temperature of the heating and stirring is 300°C to 330°C.

9. The method for preparing the composite spherical matting agent according to claim 7, characterized in that: In step S1, the stirring rate of the heating stirring is 800 rpm to 1200 rpm, and the stirring time is 1.5 to 2 hours.

10. The method for preparing the composite spherical matting agent according to claim 7, characterized in that: In step S2, the atomization pressure of the spray drying is 0.8 MPa to 1.2 MPa.

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