A matting agent, its preparation method and application

Abstract

The present application relates to a kind of flatting agent and its preparation method and application, belong to paint functional adjuvant technical field.The flatting agent of the present application is composed of composite cellulose ether thickener, alcohol ester twelve and magnesium lithium silicate protective glue, wherein composite cellulose ether thickener is made of hydroxyethyl cellulose ether or hydroxypropyl methyl cellulose ether and nano calcium carbonate by 80%:20% mass ratio composite, and is refined by colloid mill and spray drying granulation during preparation.The flatting agent is applied to water-based finish coating, can significantly improve the matting effect and stability of coating film, and has excellent compatibility with pure acrylic emulsion, film-forming aid and other components, suitable for the wide range of formulation of 200~1000 gram flatting agent addition amount, with broad industrial application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of paint functional additives, and relates to a matting agent and a preparation method and application thereof. BACKGROUND

[0002] Traditional water-based topcoat often causes light pollution due to excessively high surface gloss after construction, and especially in the fields of building exterior walls and furniture coating, a matting agent needs to be added to reduce reflectivity. Existing matting technologies mostly use silica or wax particles, but there are problems such as poor compatibility with water-based systems and unstable matting efficiency. Some technologies achieve matting by increasing the amount of fillers, which results in a sharp increase in viscosity and a decrease in leveling property of the paint, and it is difficult to balance the construction performance and matting effect.

[0003] Although cellulose ether thickening agents can adjust the rheological properties of the paint, the film strength is insufficient when used alone, and the gloss rebound is easily affected by environmental humidity. Magnesium lithium silicate protective glue, as a layered inorganic substance, can form a three-dimensional network structure to inhibit light reflection, but the interfacial bonding force with organic components is weak. Although nano calcium carbonate can improve the hardness of the system, uneven dispersion can easily cause precipitation. SUMMARY

[0004] The purpose of the present application is to provide a matting agent and a preparation method and application thereof, which has the characteristics of good matting.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] A matting agent, the matting agent comprising a composite cellulose ether thickening agent, alcohol ester twelve and magnesium lithium silicate protective glue.

[0007] The composite cellulose ether thickening agent comprises cellulose ether thickening agent and nano calcium carbonate, and the mass ratio of the two is 80:20.

[0008] The cellulose ether thickening agent is hydroxyethyl cellulose ether HEC or hydroxypropyl methyl cellulose ether HPMC with a particle size of 13-250 mu m.

[0009] Further, the preparation method of the composite cellulose ether thickening agent is as follows:

[0010] The nano calcium carbonate and deionized water are mixed in a mass ratio of 1: (1.5-2), stirred at 1000-1200 rpm for 10-15 min, refined by a colloid mill, then the cellulose ether thickening agent is added, the stirring speed is adjusted to 500-800 rpm, and the stirring is continued, the stirring time is 20-30 min, and after the stirring is completed, the composite cellulose ether thickening agent is obtained by spray drying and granulation.

[0011] Further, the colloidal grinding parameters are that the gap between the stator and the rotor is 0.1-0.2 mm, the rotation speed is 2500-3500 rpm, and the processing time is 3-5 min.

[0012] In the colloidal grinding process, the viscosity of the nano calcium carbonate suspension is 200-500 mPa·s, the temperature is 25-40℃, and the feeding flow rate is 80-150 L / h.

[0013] In the spray drying granulation, a centrifugal atomizer is used, and the rotation speed of the atomizer is 8000-12000 rpm.

[0014] Further, the mass ratio of the composite cellulose ether thickening agent and the alcohol ester twelve in the matting agent is 1:1.2.

[0015] The mass ratio of the magnesium lithium silicate protective glue and the composite cellulose ether thickening agent is 3:1.

[0016] The concentration of the magnesium lithium silicate protective glue is 8 w / v%.

[0017] Further, the preparation method comprises the following specific steps,

[0018] At room temperature, the alcohol ester twelve and the composite cellulose ether thickening agent are mixed according to the mass ratio, stirred at 50-200 rpm for 5-20 min, and a mixture A is obtained.

[0019] The mixture A is added to the magnesium lithium silicate protective glue, and stirring is performed at a rotation speed of 100-500 rpm at the same time. After the mixture A is completely added, the stirring is continued for 0.5-1 h, and the matting agent is obtained.

[0020] The application of a matting agent in the preparation of a water-based finish paint, wherein the preparation method of the water-based finish paint is as follows: 500 ml of pure acrylic emulsion is added to a container, alcohol ester twelve 30 g is slowly added under stirring as a film-forming aid, 1.0 g of surfactant is then added, followed by the addition of polyurethane thickening agent 4.5 g, after stirring for 30 min, 200-1000 g of matting agent is added, and a water-based finish varnish paint is obtained after uniform stirring.

[0021] The present application aims at the technical problems of traditional matting agents, such as difficult balance between transparency and matting efficiency, insufficient wear resistance and poor anti-settling performance of the system, and develops a matting agent based on a composite cellulose ether thickening agent. The matting agent forms a uniform distribution of micro-collapsed structure in the film forming process by regulating the particle surface morphology and particle size distribution, realizes efficient matting by using the multi-level scattering effect of light, is especially suitable for transparent varnish system, and can obtain a matt effect with significantly reduced 85° gloss, while giving the paint film excellent wear resistance and long-term storage stability. Through the selection of the particle size and particle size distribution of the cellulose ether thickening agent, the present application can obtain a paint film with special surface morphology and hand feeling, and due to its density close to water, the present application has excellent anti-settling performance.

[0022] In the present application, a composite cellulose ether thickening agent is introduced, wherein a hydroxyethyl cellulose ether (HEC) or a hydroxypropyl methyl cellulose ether (HPMC) forms a three-dimensional network structure through intermolecular hydrogen bonds, and nano calcium carbonate is uniformly dispersed in the network as a rigid filler. When the proportion of cellulose ether is 80%, the hydrogen bond interaction between the molecular chains is sufficient, and a three-dimensional network structure can be quickly constructed to provide a uniform dispersion skeleton for nano calcium carbonate. If the proportion is less than 70%, the network defects increase, leading to uneven matting microstructure; and if the proportion is higher than 90%, the rigidity is insufficient, and a stable concave surface cannot be formed.

[0023] During the film forming process of the coating, the cellulose ether network shrinks controllably due to solvent evaporation, and the embedding of nano calcium carbonate limits the shrinkage degree, so that a uniformly distributed concave microstructure is formed on the film surface. This micro roughness significantly reduces the mirror reflection light intensity through the multi-level scattering effect, and at the same time, due to the matching of the size of nano calcium carbonate and the wavelength of light, efficient matting can be realized while maintaining the high light transmittance of transparent varnish.

[0024] The addition of nano calcium carbonate improves the modulus of the composite thickening agent, and the rigid particles form an interpenetrating network with the layered structure of the magnesium lithium silicate protective colloid, enhancing the anti-deformation ability of the film layer. The alcohol ester twelve reacts with the hydroxyl groups of the cellulose ether through the ester group to form a hydrophobic modified layer on the particle surface, effectively inhibiting the swelling softening caused by water penetration, and reducing the friction coefficient of the coating surface. The synergistic effect of the three significantly improves the wear resistance of the paint film by dispersing stress through energy dissipation mechanism when the paint film bears external force.

[0025] The density of the composite thickening agent is accurately controlled by the mass ratio of nano calcium carbonate and cellulose ether, which is close to the density of the water-based system, eliminating the sedimentation driving force caused by the density difference of traditional inorganic fillers. The negative electrically charged lamellar structure of the magnesium lithium silicate protective colloid and the modified composite particles of alcohol ester twelve produce electrostatic repulsion, and the long-chain structure of alcohol ester twelve provides a steric hindrance effect, and the double stabilization mechanism makes the particles remain uniformly dispersed in the system, and no precipitation occurs during long-term storage. DETAILED DESCRIPTION

[0026] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined inventive purpose, the specific embodiments, structures, features and effects thereof according to the present application are described in detail below in combination with examples.

[0027] The aqueous acrylic emulsion is a pure acrylic emulsion, the surfactant is an aqueous coating wetting agent, the film-forming aid is alcohol ester twelve, the aqueous polyurethane thickening agent is Dow Chemical's Aqualon™ brand, the hydroxyethyl cellulose ether is NatrosolTM250HBR, and the magnesium lithium silicate protective colloid is BYK-S482.

[0028] Example 1

[0029] The composite cellulose ether thickening agent comprises hydroxyethyl cellulose ether HEC and nano calcium carbonate, and the mass ratio of the two is 80%:20%;

[0030] The preparation method of the composite cellulose ether thickening agent is,

[0031] The nano calcium carbonate and deionized water are mixed in a mass ratio of 1:2, stirred at 1000 rpm for 15 min, and refined by a colloid mill, wherein the colloid mill refining parameters are a stator-rotor gap of 0.1 mm, a rotation speed of 2500 rpm, and a processing time of 3 min. Then 13 μm hydroxyethyl cellulose ether HEC is added, the rotation speed is adjusted to 800 rpm, and the stirring is continued for 20 min. After stirring, the composite cellulose ether thickening agent is obtained by spray drying and granulation.

[0032] Take 50 grams of composite cellulose ether thickening agent with a particle size of less than 400 mesh, add 60 grams of film-forming aid alcohol ester twelve, mix and stir evenly at room temperature, then take out 24 grams of the above mixture, slowly add it to 400 milliliters of 8 w / v% magnesium lithium silicate protective colloid BYK S-482 aqueous solution under stirring, mix for 0.5 hours under stirring, the stirring speed is 500 revolutions per minute, and the cellulose ether particles are fully water-swollen by stirring to obtain a matting agent.

[0033] Example 2

[0034] The composite cellulose ether thickening agent comprises hydroxypropyl methyl cellulose ether HPMC and nano calcium carbonate, and the mass ratio of the two is 80%:20%;

[0035] The preparation method of the composite cellulose ether thickening agent is,

[0036] The nano calcium carbonate and deionized water are mixed in a mass ratio of 1:1.5, stirred at 1200 rpm for 10 min, refined by a colloid mill, wherein the colloid mill refining parameters are a stator-rotor gap of 0.2 mm, a rotation speed of 3500 rpm, and a processing time of 5 min, 150 μm of hydroxypropyl methyl cellulose ether HPMC is then added, the rotation speed is adjusted to 500 rpm, and stirring is continued for 30 min, after which the composite cellulose ether thickener is obtained by spray drying and granulation.

[0037] 50 grams of the composite cellulose ether thickener with a particle size of 100-200 mesh are taken, 60 grams of the film-forming aid alcohol ester twelve are added, and stirred evenly at room temperature, then 24 grams of the above mixture is taken and slowly added to 400 milliliters of 8 w / v% magnesium lithium silicate protective glue BYK S-482 aqueous solution under stirring, and stirred and mixed for 1.0 hour at a stirring speed of 100 revolutions / minute, until the cellulose ether particles are fully water-swell, to obtain the matting agent.

[0038] Example 3

[0039] The composite cellulose ether thickener comprises hydroxyethyl cellulose ether HEC and nano calcium carbonate, and the mass ratio of the two is 80%:20%;

[0040] The composite cellulose ether thickener is prepared by,

[0041] The nano calcium carbonate and deionized water are mixed in a mass ratio of 1:2, stirred at 1200 rpm for 10 min, refined by a colloid mill, wherein the colloid mill refining parameters are a stator-rotor gap of 0.2 mm, a rotation speed of 3500 rpm, and a processing time of 3 min, 250 μm of hydroxyethyl cellulose ether HEC is then added, the rotation speed is adjusted to 800 rpm, and stirring is continued for 20 min, after which the composite cellulose ether thickener is obtained by spray drying and granulation.

[0042] 50 grams of the composite cellulose ether thickener with a particle size of 80-100 mesh are taken, 60 grams of the film-forming aid alcohol ester twelve are added, and stirred evenly at room temperature, then 24 grams of the above mixture is taken and slowly added to 400 milliliters of 8 w / v% magnesium lithium silicate protective glue BYK S-482 aqueous solution under stirring, and stirred and mixed for 0.5 hour at a stirring speed of 300 revolutions / minute, until the cellulose ether particles are fully water-swell, to obtain the matting agent.

[0043] Comparative Example 1

[0044] In this comparative example, the composite cellulose ether thickener comprises hydroxyethyl cellulose ether HEC and nano calcium carbonate, and the mass ratio of the two is 90%:10%;

[0045] The remaining steps are consistent with Example 1.

[0046] Comparative Example 2

[0047] In this comparative example, the composite cellulose ether thickening agent includes hydroxyethyl cellulose ether HEC and nano calcium carbonate, the mass ratio of which is 70%:30%;

[0048] The remaining steps are consistent with Example 1.

[0049] Comparative Example 3

[0050] In this comparative example, only hydroxyethyl cellulose ether HEC is used, and nano calcium carbonate is not introduced, and the remaining steps are consistent with Example 1.

[0051] Application Example 1

[0052] In a container, 500 milliliters of pure propylene emulsion were added, and alcohol ester twelve 30 grams of film forming aid was slowly added under stirring, then 1.0 grams of surfactant was added, then 4.5 grams of polyurethane thickening agent was added, and after stirring for 30 minutes, 500 grams of the matting agent prepared in Example 1 was added, and after stirring uniformly, a water-based finish varnish coating was obtained.

[0053] Application Example 2

[0054] In a container, 500 milliliters of pure propylene emulsion were added, and alcohol ester twelve 30 grams of film forming aid was slowly added under stirring, then 1.0 grams of surfactant was added, then 4.5 grams of polyurethane thickening agent was added, and after stirring for 30 minutes, 500 grams of the matting agent prepared in Example 2 was added, and after stirring uniformly, a water-based finish varnish coating was obtained.

[0055] Application Example 3

[0056] In a container, 500 milliliters of pure propylene emulsion were added, and alcohol ester twelve 30 grams of film forming aid was slowly added under stirring, then 1.0 grams of surfactant was added, then 4.5 grams of polyurethane thickening agent was added, and after stirring for 30 minutes, 500 grams of the matting agent prepared in Example 3 was added, and after stirring uniformly, a water-based finish varnish coating was obtained.

[0057] Application Example 4

[0058] In a container, 500 milliliters of pure propylene emulsion were added, and alcohol ester twelve 30 grams of film forming aid was slowly added under stirring, then 1.0 grams of surfactant was added, then 4.5 grams of polyurethane thickening agent was added, and after stirring for 30 minutes, 500 grams of the matting agent prepared in Example 1 was added, and after stirring uniformly, a water-based finish varnish coating was obtained.

[0059] Application Example 5

[0060] Into a container, 500ml of pure propylene emulsion was added, alcohol ester twelve 30g was slowly added under stirring as film forming aid, then surfactant 1.0g was added, then polyurethane thickening agent 4.5g was added, after stirring for 30 minutes, matt agent prepared in Example 1 1000g was added, after stirring evenly, water-based finish varnish coating was obtained.

[0061] Application Example 6

[0062] Into a container, 500ml of pure propylene emulsion was added, alcohol ester twelve 30g was slowly added under stirring as film forming aid, then surfactant 1.0g was added, then polyurethane thickening agent 4.5g was added, after stirring for 30 minutes, matt agent prepared in Comparative Example 1 1000g was added, after stirring evenly, water-based finish varnish coating was obtained.

[0063] Application Example 7

[0064] Into a container, 500ml of pure propylene emulsion was added, alcohol ester twelve 30g was slowly added under stirring as film forming aid, then surfactant 1.0g was added, then polyurethane thickening agent 4.5g was added, after stirring for 30 minutes, matt agent prepared in Comparative Example 2 1000g was added, after stirring evenly, water-based finish varnish coating was obtained.

[0065] Application Example 8

[0066] Into a container, 500ml of pure propylene emulsion was added, alcohol ester twelve 30g was slowly added under stirring as film forming aid, then surfactant 1.0g was added, then polyurethane thickening agent 4.5g was added, after stirring for 30 minutes, matt agent prepared in Comparative Example 3 1000g was added, after stirring evenly, water-based finish varnish coating was obtained.

[0067] The finish varnish coatings prepared in Application Examples 1-8 were evenly applied on glass plates using a film applicator, and then dried at room temperature for 7 days.

[0068] The 60° gloss, 85° gloss of Application Examples 1-8 were tested according to the standard GB / T 9754-2007;

[0069] The transparency, sedimentation after 30 days of storage and appearance of Application Examples 1-8 were tested according to the standard HG / T 5065-2016;

[0070] The scratch resistance of Application Examples 1-8 was tested by cloth rubbing test method:

[0071] 1. Operation: Place the sample on the test table, apply a 10N rubbing pressure to the paint film surface with a 3M brand "easy to clean 8-layer durable cloth", repeat rubbing 100 times at a stroke of 5cm, a frequency of 30 times per minute.

[0072] 2. Key evaluation index: test the gloss change value at 85 degrees, the higher the gloss retention rate, the better the wear resistance. Among them, the gloss change less than 5% is judged as excellent, and the gloss change between 5-10% is judged as good. The gloss test uses a BYK-Gardner 4563 type micro multi-angle gloss meter, and the reference standard is GB / T 9754-2007.

[0073]

[0074] From the above data, it can be seen that the application examples 1-5 using the matting agents of examples 1-3 have a 60° gloss range of 2.0-5.8 and a 85° gloss between 2.7-10.7, with significant matting effect; while the application examples 6-8 using the matting agents of comparative examples 1-3 have a 60° gloss of 6.0-6.5 and a 85° gloss of 11.8-12.5, which is significantly higher than the example group, indicating that when the mass ratio of nano calcium carbonate to hydroxyethyl cellulose ether HEC deviates from 80%:20%, the matting performance decreases. In terms of appearance, application examples 1, 4 and 5 have a relatively delicate texture, application example 2 has a granular texture, and application example 3 has an orange peel-like texture. This difference is closely related to the particle size and preparation process of the composite cellulose ether thickener. The particle size and colloidal mill refinement parameters affect the uniformity of particle dispersion, which in turn leads to different textures.

[0075] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present application. Any modification, equivalent change and modification of the above embodiments based on the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. An optical matting agent characterized in that, The matting agent comprises a composite cellulose ether thickener, alcohol ester twelve and magnesium lithium silicate protective glue; The composite cellulose ether thickener comprises cellulose ether thickener and nano calcium carbonate, and the mass ratio of the two is 80%:20%. The cellulose ether thickener is hydroxyethyl cellulose ether HEC or hydroxypropyl methyl cellulose ether HPMC with a particle size of 13-250 μm.

2. A matting agent according to claim 1, wherein The preparation method of the composite cellulose ether thickener is as follows, The nano calcium carbonate and deionized water are mixed in a mass ratio of 1:(1.5-2), stirred at 1000-1200 rpm for 10-15 min, refined by a colloid mill, then the cellulose ether thickener is added, the stirring speed is adjusted to 500-800 rpm, and the stirring is continued for 20-30 min. After stirring, the composite cellulose ether thickener is obtained by spray drying and granulation.

3. A matting agent according to claim 2, wherein The parameters of the colloid mill refinement are as follows: the gap between the stator and the rotor is 0.1-0.2 mm, the rotation speed is 2500-3500 rpm, and the processing time is 3-5 min.

4. The matting agent of claim 1, wherein The mass ratio of the composite cellulose ether thickener and alcohol ester twelve in the matting agent is 1:1.

2. The mass ratio of the magnesium lithium silicate protective glue and the composite cellulose ether thickener is 3:

1. The concentration of the magnesium lithium silicate protective glue is 8 w / v%.

5. A process for the preparation of a matting agent according to any one of claims 1 to 4, characterized in that The specific steps of the preparation method are as follows, At room temperature, alcohol ester twelve and composite cellulose ether thickener are mixed in a mass ratio, stirred at 50-200 rpm for 5-20 min to obtain mixture A; Mixture A is added to the magnesium lithium silicate protective glue, and stirring is carried out at a rotation speed of 100-500 rpm at the same time. After mixture A is completely added, the stirring is continued for 0.5-1 h to obtain the matting agent.

6. Use of a matting agent in the preparation of an aqueous overcoat, characterized in that, The water-based finish paint comprises the matting agent of any one of claims 1-4 or the matting agent prepared by the preparation method of claim 5.

7. Use of a matting agent according to claim 6 for the preparation of water-based topcoats, characterized in that, The preparation method of the water-based finish paint is as follows: 500 ml of pure acrylic emulsion is added to a container, alcohol ester twelve 30 g is slowly added under stirring, then surfactant 1.0 g is added, then polyurethane thickener 4.5 g is added, stirring is carried out for 30 min, then matting agent 200-1000 g is added, and the water-based finish varnish paint is obtained after uniform stirring.

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