JP4866554B2 - Method for producing (meth) acrylic polymer aggregated particles for acrylic sol - Google Patents

Description

The present invention relates to the manufacture how for acrylic sol (meth) acrylic polymer aggregate particle element used in order to lower the viscosity of the acrylic sols.

  Plastisol, in which polymer fine particles are dispersed using a plasticizer as a medium, is used in the field of vehicle manufacturing such as automobile undercoats and automobile body sealers, building materials such as flooring and building materials, and interior decoration materials such as carpet backing materials and wallpaper. It is used in a wide range of industrial fields, such as the paint field such as paint, and the toy and daily goods manufacturing field.

  Conventionally, most of the plastisols were vinyl chloride sols using vinyl chloride polymer particles. However, in recent years, acrylics using (meth) acrylic polymer particles have been used in consideration of global environmental pollution during production and disposal. Transition to a system sol is under consideration. Since acrylic sol does not contain a halogen element, it has attracted attention because it has the advantage that it does not generate hydrogen chloride gas when it is incinerated and there is no concern about the generation of dioxins.

  Acrylic sols satisfy the basic performance required for plastisols: viscosity stability during storage and plasticizer retention of molded articles or gelled coatings after heat gelation. Although it is a powerful material, there is a problem that its viscosity is higher than that of vinyl chloride sol. If the viscosity of plastisol is high, the speed in each process will decrease, causing a reduction in efficiency, limiting the amount of additive added, limiting the production of high value-added products, and producing costs Inconveniences such as the inability to reduce the amount of noise occur. For this reason, there is an increasing demand for low-viscosity acrylic sols.

As a method for reducing the viscosity of the acrylic sol, (a) a method of adding a viscosity reducing agent, (b) a method of adding a diluent or a low viscosity plasticizer, and (c) two types of resin particles having different particle sizes. A blending method and the like are known.
Various compounds have been proposed as a thickener, for example, an amine compound (Patent Document 1). However, the effect of these thickening agents is to reduce thixotropy, and the effect is large in the low shear rate region but small in the high shear rate region. For this reason, there is a demand for further lowering the viscosity in a high shear rate range depending on the application.
Moreover, as a diluent and a low viscosity plasticizer, the trialkylpentanediol carboxylic acid ester (low viscosity plasticizer) is proposed, for example (patent document 2). However, when a diluent or a low-viscosity plasticizer is added, a large amount of VOC is generated when the sol is baked, leading to deterioration of the working environment and air pollution.
As a method of blending two or more kinds of resin particles having different particle diameters, the viscosity is reduced by blending a fine particle aggregate with a core-shell structure having a core compatible with a plasticizer and an incompatible shell into a fine resin. It has been reported to achieve both storage stability. However, even the acrylic sol obtained by this method has an insufficient level of storage stability and needs to be stored at about 10 ° C. For this reason, there is a need for acrylic sols that have storage stability and are easy to handle and have a sufficiently low viscosity even in applications where the storage temperature reaches room temperature to 40 ° C. or higher.

Japanese Patent Application No. 2002-202431 Japanese Patent Laid-Open No. 2001-214022 Japanese Patent No. 3437285

The object of the present invention is low viscosity, high storage stability, and can be used to efficiently manufacture articles, with excellent industrial productivity, and hydrogen chloride at the time of manufacture and disposal without generating a gas, it is to provide a manufacturing how the plastisol for (meth) acrylic polymer aggregate particle element which can suppress neither environmental pollution concerns dioxin.

That is, the gist of the present invention is that
(1) (meth) acrylic polymer aggregated particles for acrylic sol formed by agglomerating (meth) acrylic polymer particles, the specific surface area being 0.01 m ² / g or more and less than 10 m ² / g A method for producing (meth) acrylic polymer aggregated particles for acrylic sol having a compressive fracture strength of 3 MPa or more ,
Particle size of 0.01 to 30 (meth) acrylic polymer dispersion containing particles for characteristics and to luer acrylic-based sol to spray drying at a temperature of less than 0.99 ° C. greater than the 95 ° C. (meth) acrylic For producing polymer-based polymer aggregated particles
(2) (meth) acrylic polymer aggregated particles for acrylic sol formed by agglomerating (meth) acrylic polymer particles, the specific surface area being 0.01 m ² / g or more and less than 10 m ² / g. A method for producing (meth) acrylic polymer aggregated particles for acrylic sol having a compressive fracture strength of 3 MPa or more,
In a dispersion containing (meth) acrylic polymer particles having a particle diameter of 0.01 to 30 μm, a plasticizer and a film-forming aid in a proportion of 0.1% by mass or more based on (meth) acrylic polymer particles. in and added one or more one of the granulating agents, for features and to luer acrylic-based sol to spray drying at a temperature below 60 ° C. or higher 0.99 ° C. (meth) process for producing an acrylic polymer coagulated particles is there.

The (meth) acrylic polymer agglomerated particles for acrylic sol obtained by the method for producing the (meth) acrylic polymer agglomerated particles for acrylic sol of the present invention, and the composition using the same, have a low viscosity, It has high storage stability, can be manufactured efficiently in the manufacture of articles using it, has excellent industrial productivity, does not generate hydrogen chloride gas during its manufacturing or disposal, and is concerned about dioxin generation Environmental pollution can be suppressed. The method for producing (meth) acrylic polymer aggregated particles for acrylic sol of the present invention can easily produce (meth) acrylic polymer aggregated particles for acrylic sol.

The (meth) acrylic polymer aggregated particles for acrylic sol obtained by the method for producing the (meth) acrylic polymer aggregated particles for acrylic sol of the present invention are formed by aggregation of (meth) acrylic polymer particles. be for acrylic sol (meth) acrylic polymer agglomerated particles, the specific surface area is less than 0.01 m ² / g or more 10 m ² / g, the compression fracture strength Ru der least 3 MPa.

The (meth) acrylic polymer agglomerated particles for acrylic sol obtained by the method for producing (meth) acrylic polymer agglomerated particles for acrylic sols of the present invention are obtained by aggregating (meth) acrylic polymer particles. is there. The above (meth) acrylic polymer aggregated particles are secondary particles formed by aggregating smaller (meth) acrylic polymer particles (primary particles), and the primary particles are strongly fused. It also includes particles that are worn and observed as primary particles in appearance. The aggregated structure of the (meth) acrylic polymer aggregated particles can be confirmed by preparing a thin film slice embedded in an epoxy resin and observing a sample cross section with a transmission electron microscope.

The (meth) acrylic polymer used as primary particles for the (meth) acrylic polymer aggregated particles is an acrylate polymer or / and a methacrylate polymer. Such a (meth) acrylic polymer is a polymer particle obtained from a monomer having a methacryloyl group and / or an acryloyl group, and may be a homopolymer polymerized alone, or two or more monomers. The copolymer comprised by these may be sufficient. The weight average molecular weight of the (meth) acrylic polymer is preferably 10,000 to 5,000,000. When the weight average molecular weight is 10,000 or more, the acrylic sol composition has excellent storage stability and strength, and when it is 5 million or less, curing during film formation can be achieved at a low temperature.

  Specific examples of the monomer used to obtain such a (meth) acrylic polymer include acrylonitrile; methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i- (Meth) acrylates of linear alkyl alcohols such as butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate; or cyclohexyl (meth) (Meth) acrylates of cyclic alkyl alcohols such as acrylate; methacrylic acid, acrylic acid, 2-succinoloyloxyethyl methacrylate-2-methacryloyloxyethyl succinic acid, 2-malenoyloxyethyl-2-methacrylate Metacriloy Carboxyl group-containing monomers such as oxyethylmaleic acid, methacrylic acid 2-phthaloyloxyethyl-2-methacryloyloxyethylphthalic acid, and methacrylic acid 2-hexahydrophthaloyloxyethyl-2-methacryloyloxyethylhexahydrophthalic acid Sulfonic acid group-containing (meth) acrylates such as allylsulfonic acid, phosphoric acid group-containing (meth) acrylates such as 2- (meth) acryloxyethyl acid phosphate; 2-hydroxyethyl (meth) acrylate, 2- Hydroxyl group-containing (meth) acrylates such as hydroxypropyl (meth) acrylate; Carbonyl group-containing (meth) acrylates such as acetoacetoxyethyl (meth) acrylate, N-dimethylaminoethyl (meth) acrylate, N-diethylamino Amino group-containing (meth) acrylates such as ethyl (meth) acrylate; acrylamide derivatives such as acrylamide diacetone acrylamide, N-methylol acrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, N-butoxymethyl acrylamide; ) Polyfunctional (meth) acrylates such as ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc. Can do.

  The (meth) acrylic polymer as the primary particle is a monomer having the acrylonitrile, methacryloyl group and / or acryloyl group, for example, styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonyl Styrene derivatives such as styrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-finylstyrene; (poly) ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylo Polyfunctional monomers such as rupropane tri (meth) acrylate, divinylbenzene, divinylnaphthalene and divinyl ether; itaconic acid; crotonic acid; maleic acid derivatives such as maleic acid, maleic acid ester and maleic anhydride; fumaric acid and fumaric acid Fumaric acid derivatives such as esters; copolymers with monomers such as triaryl isocyanurates may also be used.

  The structure of such (meth) acrylic polymer particles is not particularly limited, and is a single structure, a core / shell structure of two or more layers, or continuous from the center to the outer part of the polymer particles. And a gradient structure whose composition changes. Among these, a core / shell structure or a gradient structure in which the composition of each layer is different is preferable because additional physical properties can be introduced into the acrylic sol as necessary.

Further, (meth) particle size of the acrylic polymer particles 0.01μm or more, Ru der less than 30 [mu] m. The polymerization particles is 0.01μm or more can take sufficient thickness for suppressing shell absorption of plasticizer when the core-shell structure, the storage stability becomes satisfactory in aggregated particles. If it is less than 30 μm, the amount of heat required to control the compression fracture strength within the range of the invention in the aggregated particles becomes small.

  Furthermore, the outermost Tg of the (meth) acrylic polymer particles is preferably 65 ° C. or higher and lower than 150 ° C. When the temperature is 65 ° C. or higher, the molecular motion of the polymer particles is suppressed, so that it is difficult for the plasticizer to enter the aggregated particles and the storage stability tends to be good, which is preferable. Moreover, when it is less than 150 degreeC, since the calorie | heat amount required in order to control the specific surface area and compression fracture strength of a (meth) acrylic-type polymer aggregated particle to the scope of the invention becomes small, it is preferable.

The aggregated particles of such ( meth) acrylic polymer particles have a specific surface area of 0.01 m ² / g or more and less than 10 m ² / g, and preferably the upper limit thereof is less than 3 m ² / g. In general, it is known that when particles in a sol absorb a plasticizer, the sol viscosity increases with time. This means that the polymer particle structure has a core-shell structure of two or more layers, or a gradient structure in which the composition changes continuously from the central part to the outer part of the polymer particle, and the outer shell part having a composition that is incompatible with the plasticizer. Even if it has, it is clear that if a composition compatible with the plasticizer is selected, the particles gradually absorb the plasticizer and the sol viscosity increases with time. When the specific surface area of the (meth) acrylic polymer aggregated particles is less than 10 m ² / g, the (meth) acrylic polymer aggregated particles are prevented from absorbing the plasticizer due to the reduction of the contact area with the plasticizer. And increase in viscosity with time can be suppressed. When the specific surface area is less than 3 m ² / g, the effect of suppressing the increase in viscosity with time can be more significantly obtained even in summer environments. On the other hand, when the specific surface area of the (meth) acrylic polymer aggregated particles is 0.01 m ² / g or more, the (meth) acrylic polymer aggregated particles settle in the plasticizer in the acrylic sol. Such a problem that the (meth) acrylic polymer aggregated particles are fused to each other hardly occurs, and it is possible to suppress a decrease in the compressive fracture strength of the aggregated particles due to the fusion of the particles.

  Here, the specific surface area is a specific surface area determined by the BET adsorption method, and is a value measured using a continuous flow surface area meter SA-6201 (manufactured by Horiba, Ltd.). This is based on measurement when gas treatment is performed.

Further, the acrylic sol (meth) acrylic polymer agglomerated particles, compressive breaking strength of not less than 3 MPa, preferably 8MPa or more. In general, the effect of reducing viscosity when blending resin particles having different particle diameters is derived from an improvement in the filling rate of resin particles in which small resin particles enter a space formed by large resin particles. In order to reduce the viscosity of the plastisol, it is preferable that the (meth) acrylic polymer aggregated particles maintain their shape in the plasticizer and maintain the plasticizer filling rate. When preparing an acrylic sol by mixing (meth) acrylic polymer aggregated particles and a plasticizer, if the (meth) acrylic polymer aggregated particles are destroyed by shearing force and become irregular in shape, the particles are filled. As the rate decreases, the aggregated particles of the (meth) acrylic polymer are destroyed, increasing the total surface area of the resin and increasing the viscosity. If the compression fracture strength of the (meth) acrylic polymer aggregated particles is 3 MPa or more, the fracture of the (meth) acrylic polymer aggregated particles due to the shearing force during the preparation of the acrylic sol is suppressed. In general, the hardness of the molded product is controlled by the amount of plasticizer added to the plastisol. However, when the plasticizer content is reduced, the shearing force applied to the (meth) acrylic polymer aggregated particles during the preparation of the acrylic sol is dramatic. To be high. When the compression fracture strength is 8 MPa or more, even when the amount of the plasticizer is small when preparing the acrylic sol, the destruction of the (meth) acrylic polymer aggregated particles is suppressed, and a molded product having a desired hardness can be obtained. .

  Here, the compressive fracture strength means the strength when one (meth) acrylic polymer aggregated particle is compressed and broken, and the value of the compressive fracture strength is a micro compression tester MCTE-500 (Shimadzu Corporation). The average value of the measured values of 10 particles is shown with a compression speed of 7.75 mN / sec.

The average particle diameter of the (meth) acrylic polymer aggregated particles is not particularly limited, but is preferably 3 μm or more and less than 500 μm. When the particle size is 3 μm or more, the particle size ratio with other substances in the acrylic sol increases, and the effect of lowering the viscosity is large. Further, when the thickness is less than 500 μm, surface irregularities derived from (meth) acrylic polymer aggregated particles are suppressed in coating applications and thin film molded products, and the product appearance tends to be good. The shape of the (meth) acrylic polymer aggregated particles is preferably a true sphere with a smooth surface. When the surface has a smooth spherical shape, the packing density of the fine particles blended in the acrylic sol is increased, and the effect of reducing the viscosity is great.

  The method for producing the (meth) acrylic polymer aggregated particles of the present invention can be obtained by a known polymerization method such as an emulsion polymerization method, a seed polymerization method, a soap-free polymerization method, a dispersion polymerization method, or a fine suspension polymerization method ( Mention a method of pulverizing a meth) acrylic polymer particle dispersion using a spray drying method (spray drying method), acid coagulation or salt coagulation followed by a drying process, a freeze drying method, a centrifugal separation method, etc. However, the spray drying method is preferable because the process is simple and it is easy to obtain spherical (meth) acrylic polymer aggregated particles having a smooth surface.

Using spray drying method, a method for producing a (meth) acrylic polymer agglomerated particles that have a the specific surface area and compressive fracture strength was obtained by polymerizing a monomer (meth) acrylic Weight A method (first method) in which the coalescence dispersion is controlled to a powder by controlling the drying temperature, or a (meth) acrylic polymer dispersion is obtained by drying the (meth) acrylic polymer dispersion. The method of controlling the heating temperature (second method), adding a plasticizer, a film-forming aid (organic solvent), and a granulating agent to the (meth) acrylic polymer dispersion, and controlling the drying temperature Examples thereof include a powdering method (third method). The method for producing the (meth) acrylic polymer aggregated particles of the present invention as the first method is more than 95 ° C. over a dispersion containing (meth) acrylic polymer particles having a particle diameter of 0.01 to 30 μm. This is a method of spray drying at a temperature of less than 150 ° C. In this method, a dispersion containing (meth) acrylic polymer particles having a particle diameter of 0.01 to 30 μm is obtained by polymerizing a monomer by a known method. Can be used. Examples of the method for spray-drying (meth) acrylic polymer particles having a particle diameter of 0.01 to 30 μm include, for example, 10% by mass to 70% of (meth) acrylic polymer particles having a particle diameter of 0.01 to 30 μm. Examples thereof include a method of spray-drying a dispersion containing a mass% concentration by using a spray dryer and setting the inlet temperature to around 250 ° C. and the outlet temperature to more than 95 ° C. and less than 150 ° C. When the temperature in spray drying exceeds 95 ° C., the increase in viscosity (thickening rate) with time in the acrylic sol can be suppressed. The fusion of the polymer particles can be reduced and the yield can be improved. When the temperature in spray drying is less than 100 ° C., the amount of heat required for drying can be further reduced, which is more preferable.

As a second manufacturing method using the above SL (meth) spray-drying method of the acrylic polymer coagulated particles, obtained by drying the (meth) acrylic polymer particle dispersion liquid (meth) acrylic polymer agglomeration When heat-treating the particles in a subsequent step, it is preferable to keep the (meth) acrylic polymer aggregated particles in a fluid state. By maintaining the fluid state, it is possible to suppress the generation of coarse particles by fusing the aggregated particles, and to suppress the reduction of the compression fracture strength.

  As a method for producing the (meth) acrylic polymer aggregated particles for plastisol according to the present invention of the third method, a dispersion containing (meth) acrylic polymer particles having a particle diameter of 0.01 to 30 μm is used as the ( Examples include a method of adding a plasticizer, a film forming aid, a granulating agent, etc. at a ratio of 0.1% by mass or more with respect to the (meth) acrylic polymer particles, and spray drying at a temperature of 60 ° C. or higher and lower than 150 ° C. be able to. Examples of the dispersion containing (meth) acrylic polymer particles having a particle size of 0.01 to 30 μm used in this method include the same dispersions as used in the first method. The temperature of the drying chamber when the (meth) acrylic polymer particle dispersion is spray-dried can be 60 ° C. or higher and lower than 150 ° C. When the drying temperature is 60 ° C. or higher, the moisture content of the obtained powder can be kept low, and when it is lower than 150 ° C., the fusion of the polymer particles to the drying chamber and piping of the spray dryer is reduced. The yield can be improved. By using a plasticizer, the (meth) acrylic polymer of any composition can control the specific surface area and particle strength within the scope of the invention at a spray drying temperature of less than 100 ° C. It is preferable to set the drying temperature to less than 100 ° C. not only from the viewpoint of productivity but also from the viewpoint of physical properties, and it is preferable because the amount of heat required for drying can be reduced.

As a plasticizer added to the dispersion containing such (meth) acrylic polymer particles, it can be appropriately selected from known ones. Specifically, for example, phthalate plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate, butyl benzyl phthalate Adipic acid ester plasticizers such as dimethyl adipate, dibutyl adipate, diisobutyl adipate, dihexyl adipate, di-2-ethylhexyl adipate, diisononyl adipate, dibutyl diglycol adipate; trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate , Tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, Phosphate ester plasticizers such as xylenyl phosphate and cresylphenyl phosphate; Trimellitic ester plasticizers such as tri-2-ethylhexyl trimellitate; dimethyl sebacate, dibutyl sebacate, di-2-ethylhexyl seba Sebate ester plasticizers such as Kate; Aliphatic polyester plasticizers such as poly-1,3-butanediol adipate; Benzoic acid plasticizers such as diethylene glycol dibenzoate and dibutylene glycol dibenzoate; Epoxidized soybean oil Epoxidized ester plasticizers; alkyl sulfonic acid phenyl ester plasticizers such as alkyl sulfonic acid phenyl esters; alicyclic dibasic acid ester plasticizers; polyether plasticizers such as polypropylene glycol and polybutylene glycol; acid Can be mentioned citric acid based plasticizers such as cetyl tributyl. Among these, highly polar plasticizers such as alkyl sulfonic acid phenyl ester, acetyl tributyl citrate, and diethylene glycol dibenzoate are preferable because they are highly effective when added in a small amount.
A plasticizer is a material originally contained in an acrylic sol, and is most preferable as an additive because it does not adversely affect processability and various physical properties of a molded product.

  Further, a film forming aid or a granulating agent may be used together with the plasticizer or instead of the plasticizer. Specific examples of such film-forming aids include N-methyl-2-pyrrolidone; ethylene glycol, propylene glycol and derivatives thereof; low-boiling alcohols such as n-hexyl alcohol and benzodialcohol; methyl cellosolve, ethyl cellosolve, Examples of granulating agents include water-soluble polymers such as polyvinyl alcohols, celluloses, polyethylene glycols, polycarboxylic acids, myristyl alcohol, cetyl alcohol, and the like. Examples thereof include low molecular weight compounds and waxes that are solid at room temperature.

  The amount of the plasticizer used in the method for producing the (meth) acrylic polymer aggregated particle of the present invention, and the film-forming auxiliary and granulating agent used together with or in place of the plasticizer is (meth) acrylic The ratio is 0.1% by mass or more based on the polymer particles. When the amount of the plasticizer used is 0.1% by mass or more, the plasticizer and the like are uniformly distributed throughout the (meth) acrylic polymer particles, and the compressive fracture strength and specific surface area of the particles cannot be uneven. The amount of plasticizer used is particularly preferably 1% by mass or more and less than 20% by mass. When the amount of plasticizer used is 1% by mass or more, the heat required to control the specific surface area can be further reduced, and the (meth) acrylic polymer agglomerates that are thermally fused to the drying chamber or piping Particles can be reduced and yield can be improved. When the amount of the plasticizer used is less than 20% by mass, there is no adverse effect on the stability and viscosity of the dispersion when added to the (meth) acrylic polymer particle dispersion, which is preferable.

  As a method of adding such a plasticizer, a method of adding in advance to a raw material (meth) acrylic polymer particle dispersion, a method of spraying a plasticizer or the like on aggregated particles in a drying step, and a method were obtained. For example, a method of spraying a plasticizer on the aggregated particles in a later step may be used.

  In the method of adding the plasticizer or the like to the (meth) acrylic polymer particle dispersion in advance, a method of adding a plasticizer or the like dispersed in water using an emulsifier is preferable. In the method of spraying a plasticizer or the like on the aggregated particles in the drying step and reheating in the post-processing step, or the method of spraying the plasticizer or the like in the post-process of heat-treating the aggregated particles, The droplets are preferably atomized to 500 μm or less. When the plasticizer to be added is 500 μm or less, it is uniformly distributed with the (meth) acrylic polymer aggregated particles, so that the above effect can be obtained with a small addition amount.

A acrylic-based sol composition, obtained by the method of least the (meth) acrylic polymer agglomerated particles and (meth) acrylic polymer agglomerated particles, plasticizers, Zomakusuke and granulating agents among preferred those containing as any one or more, in the (meth) acrylic polymer agglomerated particles co preferably comprises a small diameter of the polymer particles from the (meth) acrylic polymer agglomerated particles. The mixing ratio of the above (meth) acrylic polymer aggregated particles and small-diameter polymer particles can be selected as appropriate. However, if the blending ratio of the ( meth) acrylic polymer aggregated particles is large, the viscosity in the acrylic sol is low. Become.

The plasticizer to be blended into A acrylic-based sol composition can be suitably selected from known plasticizers such. Specific examples of the plasticizer include those similar to the plasticizer used in the method for producing the (meth) acrylic polymer aggregated particles of the present invention.

The A acrylic-based sol composition, the (meth) optionally within a range that does not impair the functionality of the acrylic polymer agglomerated particles, titanium oxide, pigments such as carbon black, further defoamer, fungicide, and deodorant Various additives such as an agent, an antibacterial agent, a surfactant, a lubricant, an ultraviolet absorber, a fragrance, a foaming agent, a leveling agent, an adhesive, and a viscosity reducing agent may be appropriately blended. Moreover, although reduction of the usage-amount is calculated | required for the reason mentioned above, it is also possible to mix | blend diluents, such as a mineral terpene and a mineral spirit, and to aim at further viscosity reduction.

The apparatus for preparing the A acrylic-based sol composition can be appropriately selected and used those known methods, for example, pony mixer (Pony mixer), change the can mixer (Change-can mixer), a Hobart mixer (Hobert mixer ), Planetary mixers, butterfly mixers, raking machines, kneaders and the like.

A acrylic-based sol composition, even as a coating material and can also be used as a molding material, the coating method and molding method is not particularly limited. When using the A acrylic-based sol composition as a coating material, as a method for forming a coating material onto a substrate, a dip coating method, spray coating method, knife coating method, a roll coating method, curtain flow coating, brush coating paint And a method of forming a film by heating and gelling an acrylic sol coating film formed by a method, an electrostatic coating method, or the like.

Also, when using the A acrylic-based sol composition as a molding material, a method for producing a molded article, a dip molding method, cast molding method, a splash molding method, using the Rotational over relational molding method or the like, the gel by heating Can be mentioned.

As an article obtained by using the acrylic sol composition, and the coating material, may be mentioned a molded article, for example, wallpaper, vinyl steel plate, and coating materials such as automotive coatings, leather, dolls, toys, gloves And moldings such as flooring, sponge products, automobile parts, and industrial machine parts.

Hereinafter, the present invention will be described in detail by way of examples. The technical scope of the present invention is not limited to these.
The characteristic measurement method and evaluation method in the examples are as follows.
[viscosity]
After keeping the acrylic sol composition in a thermostatic bath at 25 ° C. for 3 hours, an EHD type viscometer (manufactured by Tokyo Keiki Co., Ltd., product name: EHD type viscometer, rotor: special cone (cone angle 3 degrees)) The viscosity (unit: mPa · s) after 1 minute at a rotational speed of 20 rpm was measured. The measured viscosities were classified as follows and shown in the table.
“◎”: Less than 3500 mPa · s “◯”: 3500 mPa · s or more and less than 7000 mPa · s “X”: 7000 mPa · s or more

[Storage stability (thickening rate)]
About the obtained acrylic sol composition, the viscosity (α) after 1 hour from the preparation and the viscosity (β) after storage for 10 days in an atmosphere of 40 ° C. are measured. The thickening rate (%) was determined using (2).
The viscosity of the composition was measured after 1 minute at a rotation speed of 20 rpm using an EHD type viscometer (manufactured by Tokyo Keiki Co., Ltd., product name: EHD type viscometer, rotor: special cone (conical angle 3 degrees)). The viscosity of was measured.
Thickening rate (%) = (β−α) / α × 100 (2)
“◎”: less than 500%.
“◯”: 500% or more and less than 1000%.
“×”: 1000% or more.

[productivity]
The productivity was evaluated as ◎ when the drying temperature was less than 100 ° C, ◯ when the drying temperature was 100 ° C or more and less than 150 ° C, and x when 150 ° C or more.
[Compressive strength]
Measurement was performed using a micro compression tester MCTE-500 (manufactured by Shimadzu Corporation). A flat 50 μm indenter was used as the indenter. The load was measured when the compression speed was 7.75 mN / sec. The measured value was an average value when a total of 10 fine particles were subjected to compression fracture.

[Specific surface area]
Measurement was performed using a continuous flow surface area meter SA-6201 (manufactured by Horiba, Ltd.). The sample to be tested was degassed at 50 ° C. for 30 minutes as a pretreatment.
[Particle size]
The volume average particle size was measured using a laser scattering particle size distribution analyzer (Horiba, Ltd., LA-910) as measured with pure water as a dispersion medium.

[Preparation of polymer particle dispersion (E1)]
Into a 2 liter four-necked flask equipped with a thermometer, nitrogen gas inlet tube, stirring rod, dropping funnel, and cooling tube, put 600 g of pure water, ventilate nitrogen gas for 30 minutes, and dissolve oxygen in pure water. Was replaced. After stopping the aeration of nitrogen gas, the temperature was raised to 80 ° C. while stirring at 200 rpm. When the internal temperature reached 80 ° C., 0.006 g of sodium dialkylsulfosuccinate (trade name: Perex O-TP, manufactured by Kao Corporation) and 0.3 g of potassium persulfate were added, followed by 240 g of methyl methacrylate and n- A mixture (Mc1) of 180 g of butyl methacrylate and 2.1 g of sodium dialkylsulfosuccinate (manufactured by Kao Corporation, trade name: Perex O-TP) was added dropwise over 3 hours. Stirring was further continued at 80 ° C. for 1 hour, and then a mixture (Ms1) of 174 g of methyl methacrylate and 6 g of methacrylic acid and 0.9 g of sodium dialkylsulfosuccinate (trade name: Perex O-TP, manufactured by Kao Corporation) was added. It was dripped over 2 hours. Furthermore, stirring was continued at 80 ° C. for 1 hour to obtain a polymer particle dispersion (E1).

[Preparation of polymer particle dispersion (E2-5)]
Other than changing the amount of emulsifier and monomer mixture (Mc1), (Ms1) added when the internal temperature reaches 80 ° C. to the amount of emulsifier and monomer mixture (Mc2-5) and (Ms2-5) shown in Table 1 Obtained a polymer particle dispersion (E2-5) in the same manner as described above.

[Preparation of polymer aggregated particles (P1)]
The polymer particle dispersion (E1) is spray-dried using an L-8 type spray dryer (manufactured by Okawara Kako Co., Ltd.) (inlet temperature / outlet temperature = 250 ° C./130° C. disc rotation speed 30000 rpm), and polymer Aggregated particles (P1) were obtained. The obtained polymer aggregated particles had a compressive fracture strength of 4 MPa, a specific surface area of 2.9 m ² / g, and an average particle size of 41 μm.

[Preparation of polymer aggregated particles (P2 to 9 and 17 to 20)]
The polymer particle dispersions (E1 to 5) were spray-dried under the conditions shown in Table 2 using an L-8 type spray dryer (manufactured by Okawara Chemical Co., Ltd.), and polymer aggregated particles (P2 to 9 and 17 to 17). 20) was obtained. Table 3 shows the compression fracture strength, specific surface area, and average particle diameter of the obtained polymer aggregated particles.

[Preparation of polymer aggregated particles (P10)]
12 g of a plasticizer (ATBC), 12 g of pure water, and 0.12 g of Perex OTP were mixed with Ultra Tarax (manufactured by IKA) (11000 rpm × 60 seconds) to obtain an emulsion of a plasticizer. This is added to the polymer particle dispersion (E3) and spray-dried using an L-8 type spray dryer (manufactured by Okawara Chemical Co., Ltd.) (inlet temperature / outlet temperature = 200 ° C./90° C. disc rotation speed) 30000 rpm), and polymer aggregated particles (P10) were obtained. The resulting polymer aggregated particles had a compressive fracture strength of 9 MPa, a specific surface area of 2.1 m ² / g, and an average particle size of 41 μm.

[Preparation of polymer aggregated particles (P11-16 and 21)]
The plasticizer emulsion obtained under the conditions shown in Table 2 is added to the polymer particle dispersion (E3), and the conditions shown in Table 2 using an L-8 type spray dryer (manufactured by Okawara Koki Co., Ltd.). Was spray dried to obtain polymer aggregated particles (P11-16 and 21). Table 3 shows the compression fracture strength, specific surface area, and average particle diameter of the obtained polymer aggregated particles.

[Example 1]
70 parts of polymer agglomerated particles (P1) as a polymer, 30 parts of Dianal LP-3106 (manufactured by Mitsubishi Rayon Co., Ltd.) and 80 parts of diisononyl phthalate (DINP) as a plasticizer are weighed, and a vacuum mixer ((stock) ) After being mixed at an atmospheric pressure (0.1 MPa) for 10 seconds using a product manufactured by Sinky, product name: ARV-200, the pressure was subsequently reduced to 2.7 kPa and mixed for 110 seconds to obtain an acrylic sol composition. The obtained acrylic sol composition had a viscosity of 3600 mPa · s and a thickening rate of 50%.

[Examples 2 to 16, Comparative Examples 1 to 5]
An acrylic sol composition was obtained in the same manner as in Example 1 except that the polymer aggregated particles shown in Table 3 were used instead of the polymer aggregated particles (P1). Table 3 shows the viscosity and thickening rate of the obtained acrylic sol composition.

Examples 1 to 9 Examples 1 to 3 are examples using polymer aggregated particles obtained from polymer particle dispersions having different primary particle sizes. Examples 4 and 5 are obtained by changing the conditions during spray drying. Examples 6 and 7 are examples using polymer aggregated particles obtained from polymer particle dispersions having different polymer particle compositions, and Examples 8 and 9 are secondary examples. This is an example in which polymer aggregated particles having different particle diameters are used. In any example, an acrylic sol composition having low viscosity and good stability during storage was obtained.

About Comparative Examples 1-4 Comparative Examples 1 and 2 are examples using polymer aggregated particles whose compressive fracture strength is within the scope of the present invention but whose specific surface area is outside the scope of the present invention. Comparative Examples 3 and 4 are examples in which polymer agglomerated particles having a specific surface area within the scope of the present invention but having a compressive fracture strength outside the scope of the present invention were used. In Comparative Examples 1 and 2, the initial viscosity is low, but the thickening rate is 1,000% or more, and practical application is difficult. In Comparative Examples 3 and 4, the initial viscosity is high and the effect of reducing the viscosity is not observed. Further, since the initial viscosity is high, the EHD type viscometer could not evaluate the thickening rate.

Examples 10 to 16 Examples 10 to 16 are examples in which polymer aggregated particles obtained by adding a plasticizer and spray-drying a polymer particle dispersion are used. Among them, Examples 10 to 12 are examples in which the amount of plasticizer added is different, Examples 13 and 14 are examples in which the kind of plasticizer to be added is different, and Examples 15 and 16 are different in the dispersion state of the plasticizer when added. It is an example. In any case, an acrylic sol composition having a low viscosity and a low viscosity increase rate was obtained. The polymer aggregated particles used in this example are prepared at a low drying temperature and are excellent in productivity.

About Comparative Example 5 Comparative Example 5 is an example in which the amount of plasticizer to be added is out of the scope of the present invention. The polymer aggregated particles are prepared at a low drying temperature and are excellent in productivity, but the specific surface area of the polymer aggregated particles is out of the scope of the present invention. Although acrylic sol has a low viscosity, it has a high viscosity increase rate and is difficult to put into practical use.

Claims (2)

(Meth) acrylic polymer particles for acrylic sol formed by aggregation of (meth) acrylic polymer particles, with a specific surface area of 0.01 m ² / g or more and less than 10 m ² / g, and compression fracture strength a manufacturing method of 3MPa or more der luer acrylic-based sol (meth) acrylic polymer agglomerated particles,
A (meth) acrylic polymer for acrylic sol, characterized by spray-drying a dispersion containing (meth) acrylic polymer particles having a particle diameter of 0.01 to 30 μm at a temperature of more than 95 ° C. and less than 150 ° C. A method for producing coalesced aggregated particles. A (meth) acrylic polymer aggregated particle for acrylic sol formed by aggregating (meth) acrylic polymer particles having a specific surface area of 0.01 m ² / G or more 10m ² / G and a method for producing (meth) acrylic polymer aggregated particles for acrylic sol having a compressive fracture strength of 3 MPa or more,
In a dispersion liquid containing (meth) acrylic polymer particles having a particle diameter of 0.01 to 30 μm, a plasticizer and a film-forming aid in a proportion of 0.1% by mass or more with respect to (meth) acrylic polymer particles. And a method for producing (meth) acrylic polymer aggregated particles for acrylic sol, wherein one or more of the granulating agents are added and spray-dried at a temperature of 60 ° C. or higher and lower than 150 ° C.