JP4067780B2 - Method for producing amino resin particles - Google Patents

Description

【００４４】
【発明の効果】
本発明のアミノ樹脂粒子の製造方法は、以上のように、アミノ系化合物とホルムアルデヒドとを反応させて、アミノ樹脂前駆体を含む反応液を得る反応工程；反応液を乳濁させて乳濁液を得る乳濁工程；乳濁液に、染料を水に溶解してなる水溶液を添加する着色工程；乳濁液に触媒を添加してアミノ樹脂前駆体を乳濁状態で硬化させる硬化工程；を含む構成である。
【００４５】
また、本発明のアミノ樹脂粒子の製造方法は、以上のように、水溶液における染料の濃度が０．１〜５重量％の範囲内である構成である。
【００４６】
本発明のアミノ樹脂粒子の製造方法は、以上のように、上記アミノ系化合物が、ベンゾグアナミン、シクロヘキサンカルボグアナミン、シクロヘキセンカルボグアナミン、メラミンからなる群より選ばれる少なくとも一種の化合物を４０重量％以上含んでいる構成である。
【００４７】
本発明のアミノ樹脂粒子の製造方法は、以上のように、アミノ系化合物１モルに対するホルムアルデヒドの割合が、２〜３モルの範囲内である構成である。
【００４８】
上記の構成によれば、染料を水に溶解してなる水溶液を乳濁液に添加するので、染料が乳濁液に均一に混合され、添加量に応じた着色がなされると共に、粒子毎或いは反応毎に着色ムラが生じることも無い。つまり、粒子毎や反応毎にバラツキを生じることなく、充分にかつ均一に着色された、即ち、個々の粒子の色調が揃ったアミノ樹脂粒子を簡単に得ることができるという効果を奏する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing amino resin particles, which can be suitably used as fillers such as polyolefin, polyvinyl chloride, various rubbers, various paints, toners, rheology control agents, colorants and the like.
[0002]
[Prior art]
Conventionally, a method for producing colored amino resin particles by reacting an amino compound with formaldehyde to obtain an amino resin precursor, adding a dye, and then curing the amino resin precursor is known. It has been. As a specific method for coloring, for example, JP-A-49-57091 discloses a reaction solution containing an amino resin precursor in a state in which the dye is left as it is (for example, powder, granule, liquid, etc.). The method of adding is disclosed.
[0003]
[Problems to be solved by the invention]
However, in the conventional method in which a dye is simply added, the dye adheres (sticks) to the side wall of the reaction vessel (reactor), the stirring rod, the stirring blade, or the thermometer, and uniformly in the reaction solution. Not mixed. Therefore, not only coloring according to the added amount is performed, but also coloring unevenness occurs for each particle or each reaction. That is, there is a problem in that amino resin particles that are sufficiently and uniformly colored cannot be obtained without causing variations in each particle or reaction.
[0004]
The present invention has been made in view of the above-described conventional problems, and the object thereof is to easily obtain sufficiently and uniformly colored amino resin particles without causing variations among particles or reactions. An object of the present invention is to provide a method for producing amino resin particles.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the method for producing amino resin particles of the present invention is a reaction step in which an amino compound and formaldehyde are reacted to obtain a reaction solution containing an amino resin precursor; the reaction solution is emulsified. An emulsion process to obtain an emulsion; a coloring process in which an aqueous solution obtained by dissolving a dye in water is added to the emulsion; a catalyst is added to the emulsion to cure the amino resin precursor in an emulsion state. A curing step.
[0006]
Moreover, in order to solve said subject, the manufacturing method of the amino resin particle | grains of this invention is characterized by the density | concentration of the dye in aqueous solution being in the range of 0.1 to 5 weight%.
[0007]
In the method for producing amino resin particles of the present invention, in order to solve the above problems, the amino compound is 40 weight percent of at least one compound selected from the group consisting of benzoguanamine, cyclohexanecarboguanamine, cyclohexenecarboguanamine, and melamine. It is characterized by containing more than%.
[0008]
In order to solve the above problems, the method for producing amino resin particles of the present invention is characterized in that the ratio of formaldehyde to 1 mol of the amino compound is in the range of 2 to 3 mol.
[0009]
According to said structure, since the aqueous solution formed by melt | dissolving dye in water is added to an emulsion, a dye adheres to the side wall of a reaction tank (reactor), a stirring rod, a stirring blade, or a thermometer. There is no. Therefore, since the dye is uniformly mixed in the emulsion, coloring according to the added amount is performed, and coloring unevenness does not occur for each particle or each reaction. That is, it is possible to easily obtain amino resin particles that are sufficiently and uniformly colored, that is, the color tone of each particle is uniform, without causing variations among particles or reactions.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described as follows. The method for producing amino resin particles according to the present invention comprises a reaction step of reacting an amino compound and formaldehyde to obtain a reaction solution containing an amino resin precursor, and a milk for obtaining an emulsion by emulsifying the reaction solution. A suspension step, a coloring step of adding an aqueous solution obtained by dissolving a dye in water to the emulsion, and a curing step of adding a catalyst to the emulsion to cure the amino resin precursor in an emulsion state. Contains.
[0011]
Specific examples of the amino compounds include benzoguanamine (2,4-diamino-6-phenyl-sym.-triazine), cyclohexanecarboguanamine, cyclohexenecarboguanamine, melamine, and the like, but are particularly limited. It is not a thing. These amino compounds may be used alone or in combination of two or more, but at least one compound selected from the compound group exemplified above is 40% by weight or more and 100% by weight or less. It is particularly preferable that it is included within the range.
[0012]
When the amino compound and formaldehyde are reacted, water is used as a solvent. Therefore, as the form of addition of formaldehyde, specifically, for example, a method of adding (preparing) in the form of an aqueous solution (formalin), a method of generating formaldehyde in the reaction solution by adding trioxane or paraformaldehyde to water Etc. Among these, the method of adding formaldehyde in the state of aqueous solution is more preferable.
[0013]
The ratio of formaldehyde with respect to 1 mol of the amino compound is preferably in the range of 2 to 3 mol, and more preferably in the range of 2 to 2.5 mol. If the ratio of formaldehyde is out of the above range, it is not preferable because an unreacted product of amino compound or formaldehyde increases. It should be noted that the addition amount of the amino compound and formaldehyde relative to water, that is, the concentration of the amino compound and formaldehyde at the time of preparation is preferably higher as long as the reaction is not hindered. More specifically, the viscosity in the temperature range of 95 to 98 ° C. of the reaction solution containing the amino resin precursor as a reactant is 2 × 10 ^{−2 to} 5.5 × 10 ⁻² Pa · s (20 The concentration can be adjusted and controlled within the range of -55 cP) . Moreover , it is further more preferable that it is a density | concentration which can add a reaction liquid to the aqueous solution of an emulsifier so that the density | concentration of an amino resin precursor may be in the range of 30 to 60 weight% in an emulsion process.
[0014]
The method for measuring the viscosity is not particularly limited, but the viscosity is determined so that the progress of the reaction can be grasped immediately (in real time) and the end point of the reaction can be accurately determined. The method using a measuring machine is optimal. Specific examples of the viscosity measuring machine include a vibration viscometer (manufactured by MIVI ITS Japan; model name MIVI 6001). This viscometer has a vibrating part that constantly vibrates. When the vibrating part is immersed in the reaction liquid, the viscosity of the reaction liquid increases and a load is applied to the vibrating part. Is converted to and displayed immediately.
[0015]
The pH of the reaction solution is desirably adjusted to neutral or weakly basic using, for example, sodium carbonate, sodium hydroxide, potassium hydroxide, aqueous ammonia or the like. The amount of sodium carbonate used is not particularly limited. By reacting an amino compound with formaldehyde in water, an amino resin precursor which is a so-called initial condensate can be obtained. The reaction temperature is not particularly limited, but it is within a temperature range of 95 to 98 ° C. so that the progress of the reaction can be immediately grasped and the end point of the reaction can be accurately determined. It is desirable that In the reaction step , when the viscosity of the reaction solution in the temperature range of 95 to 98 ° C. falls within the range of 2 × 10 ^{−2 to} 5.5 × 10 ⁻² Pa · s, the reaction solution is What is necessary is just to complete | finish by performing operation, such as cooling. Thereby, the reaction liquid containing an amino resin precursor is obtained. Accordingly, the reaction time is not particularly limited.
[0016]
Note that the viscosity of the reaction liquid at the end of the reaction is significantly higher than the viscosity of the aqueous solution charged with the amino compound and formaldehyde (at the start of the reaction), and therefore is hardly affected by the concentration of the charged raw materials. . Amino resin precursor is soluble in organic solvents such as acetone, dioxane, methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, methyl ethyl ketone, toluene, xylene Is substantially insoluble in water.
[0017]
The smaller the viscosity of the reaction solution, the smaller the particle size of the generated particles. However, when it is desired to produce amino resin particles having almost the same particle size (narrow particle size distribution) that do not need to be classified, etc. , the viscosity of the reaction solution within the temperature range of 95 to 98 ° C. Is adjusted and controlled within the range of 2 × 10 ^{−2 to} 5.5 × 10 ⁻² Pa · s . When the viscosity of the reaction solution is less than 2 × 10 ⁻² Pa · s, or exceeds 5.5 × 10 ⁻² Pa · s, the amino resin particles have almost the same particle size (narrow particle size distribution). Can't get. That is, when the viscosity of the reaction solution is less than 2 × 10 ⁻² Pa · s (20 cP), the stability of the emulsion obtained in the emulsion step becomes poor. For this reason, when the amino resin precursor is cured in the curing step, the resulting amino resin particles are enlarged or the particles are aggregated. That is, since it becomes impossible to control the particle diameter of the amino resin particles, only amino resin particles with irregular particle diameters (wide particle size distribution) can be obtained. Moreover, since the stability of the emulsion is poor, the particle diameter of the amino resin particles changes every time it is manufactured (each batch), resulting in variations in the product. On the other hand, when the viscosity of the reaction liquid exceeds 5.5 × 10 ⁻² Pa · s (55 cP), for example, a high-speed stirrer used in the emulsion process is loaded and the shearing force is reduced. Can not be stirred (emulsified). For this reason, since it becomes impossible to control the particle diameter of amino resin particles, only amino resin particles having irregular particle diameters (wide particle size distribution) can be obtained.
[0018]
As described above, by adjusting and controlling the viscosity of the reaction solution in the temperature range of 95 to 98 ° C. within the range of 2 × 10 ^{−2 to} 5.5 × 10 ⁻² Pa · s in the reaction step, The progress of the reaction between the amino compound and formaldehyde in the reaction step can be immediately grasped (in real time), and the end point of the reaction can be accurately determined. Therefore, the particle diameter of the resulting amino resin particles can be easily controlled. Therefore, amino resin particles having almost the same particle diameter (narrow particle size distribution) can be easily produced.
[0019]
An emulsion can be obtained by emulsifying the reaction solution. Specific examples of the emulsifier constituting the protective colloid include, for example, polyvinyl alcohol, carboxymethylcellulose, sodium alginate, polyacrylic acid, water-soluble polyacrylate, polyvinylpyrrolidone, and the like. Absent. These emulsifiers are used in the form of an aqueous solution in which the entire amount is dissolved in water, or a part of the emulsifier is used in the state of an aqueous solution, and the rest is used as it is (for example, powder, granule, liquid, etc.) Used in. Of the emulsifiers exemplified above, polyvinyl alcohol is more preferable in consideration of the stability of the emulsion, interaction with the catalyst, and the like. Polyvinyl alcohol may be a completely saponified product or a partially saponified product. Moreover, the polymerization degree of polyvinyl alcohol is not particularly limited. The larger the amount of emulsifier used relative to the amino resin precursor, the smaller the particle size of the particles produced. The amount of the emulsifier used relative to 100 parts by weight of the amino resin precursor is preferably in the range of 1 to 30 parts by weight, and more preferably in the range of 1 to 5 parts by weight.
[0020]
In the emulsion step, the reaction solution is added to the aqueous solution of the emulsifier so that the concentration of the amino resin precursor (that is, the solid content concentration) is in the range of 30 to 60% by weight, and then the temperature range of 70 to 100 ° C. Emulsify inside. The concentration of the aqueous solution of the emulsifier is not particularly limited as long as the concentration of the amino resin precursor can be adjusted within the above range. As a stirring method in this step, a method using a device capable of stirring more strongly, specifically, a method using, for example, a so-called high-speed stirrer or a homomixer is preferable. When the concentration of the amino resin precursor is less than 30% by weight, the productivity of amino resin particles is lowered. On the other hand, when the concentration of the amino resin precursor exceeds 60% by weight, the resulting amino resin particles are enlarged or the particles are aggregated. That is, since it becomes impossible to control the particle diameter of the amino resin particles, only amino resin particles with irregular particle diameters (wide particle size distribution) can be obtained.
[0021]
Amino resin precursors and amino resins are excellent in affinity with dyes. The dye added to the obtained emulsion in the coloring step is not particularly limited as long as it is a dye that dissolves in water, that is, a water-soluble dye. Specific examples of water-soluble dyes include basic dyes such as rhodamine B, rhodamine 6GCP (manufactured by Sumitomo Chemical Co., Ltd.), methyl violet FN, and Victoria blue FN; quinoline yellow SS-5G and quinoline yellow. Examples include, but are not particularly limited to, acid dyes such as GC (manufactured by Chuo Synthetic Chemical Co., Ltd.), Acid Magenta O, Methyl Violet FB, Victoria Blue FB; These dyes may be used alone or in combination of two or more.
[0022]
The concentration of the dye in the aqueous solution is not particularly limited, but is more preferably in the range of 0.1 to 5% by weight, and still more preferably in the range of 1 to 3% by weight. When the concentration of the dye is less than 0.1% by weight, the amount of the aqueous solution to be added becomes large, and the productivity of amino resin particles may be lowered. On the other hand, when the concentration of the dye exceeds 5% by weight, the stability of the emulsion is lowered, and thus the resulting amino resin particles may be enlarged or the particles may be aggregated. The method for preparing the aqueous solution obtained by dissolving the dye in water and the method for adding and mixing the aqueous solution to the emulsion are not particularly limited.
[0023]
In the present invention, if necessary, a dye may be further added to the reaction solution obtained in the reaction step as a pre-coloring step. The dye is not particularly limited as long as the dye is dispersed in water, that is, an oil-soluble dye. Specific examples of the oil-soluble dye include oil orange B, oil blue BA (manufactured by Chuo Synthetic Chemical Co., Ltd.), azosol brilliant yellow 4GF, azosol fast blue GLA, oil red TR-71, and the like. Solvent-soluble dyes; disperse dyes such as Fast Yellow YL, Fast Blue FG, Seriton Pink FF3B, and Seriton Pink 3B; These dyes may be used alone or in combination of two or more. By performing the pre-coloring step in which a dispersion obtained by dispersing an oil-soluble dye in water is added to the reaction solution, and the above-described coloring step, the color tone of each particle is more sufficiently and uniformly colored. Can be obtained.
[0024]
The content of the dye in the dispersion is not particularly limited, but is preferably in the range of 1 to 50% by weight, and more preferably in the range of 20 to 40% by weight. When the content of the dye is less than 1% by weight, the amount of the dispersion to be added becomes large, and the productivity of amino resin particles may be lowered. On the other hand, when the content of the dye exceeds 50% by weight, the fluidity of the dispersion liquid is lowered, so that the handling property at the time of addition is lowered and the addition may take time. Further, since oil-soluble dyes have poor wettability with water, a dispersion aid can be used as necessary when the dye is dispersed in water. The method for preparing a dispersion obtained by dispersing a dye in water and the method for adding and mixing the dispersion to the reaction solution are not particularly limited.
[0025]
Moreover, in this invention, in order to prevent aggregation of an amino resin particle more reliably, you may add an inorganic particle to an emulsion as needed. Specific examples of the inorganic particles include silica fine particles, zirconia fine particles, aluminum powder, alumina sol, and serie sol. The specific surface area of the inorganic particles is more preferably in the range of 50 to 400 m ² / g, and the particle diameter is more preferably 0.05 μm or less. If the specific surface area or the particle diameter is within the above range, an even more excellent effect can be exhibited in preventing the aggregation of amino resin particles.
[0026]
Specific examples of the method for adding the inorganic particles to the emulsion include a method of adding the particles as they are (particulate), a method of adding the particles in a dispersion in which the particles are dispersed in water, and the like. It is done. The amount of inorganic particles added to the emulsion is preferably in the range of 3 to 10 parts by weight with respect to 100 parts by weight of the amino resin precursor, but is not particularly limited.
[0027]
The amino resin particles according to the present invention can be obtained by adding a catalyst to the emulsion after addition and mixing of the aqueous dye solution and curing the amino resin precursor in an emulsion state. An acid is suitable as the catalyst (curing catalyst). Specific examples of the acid include mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; ammonium salts of these mineral acids; sulfamic acids; sulfonic acids such as benzenesulfonic acid, paratoluenesulfonic acid, and dodecylbenzenesulfonic acid. Organic acids such as phthalic acid, benzoic acid, acetic acid, propionic acid, salicylic acid; and the like, but are not particularly limited. These catalysts may be used alone or in combination of two or more. The amount of the catalyst used with respect to 100 parts by weight of the amino resin precursor is preferably in the range of 0.1 to 5 parts by weight. When the usage-amount of a catalyst exceeds 5 weight part, an emulsion state will be destroyed and particle | grains will aggregate. On the other hand, if the amount of the catalyst used is less than 0.1 parts by weight, a long time is required for the reaction or curing becomes insufficient.
[0028]
The reaction temperature is preferably within the range of 15 (normal temperature) to 100 ° C. The end point of the reaction may be judged by sampling or visual observation, and therefore the reaction time is not particularly limited. As a stirring method in the curing step, a method using an apparatus that can stir more strongly, specifically, a method using, for example, a so-called high-speed stirrer or a homomixer is preferable.
[0029]
By condensing and curing the amino resin precursor, an amino resin that is a thermosetting resin is obtained. That is, colored amino resin particles according to the present invention are obtained. The average particle diameter of the amino resin particles is not particularly limited, but is preferably in the range of 1 to 30 μm, and more preferably in the range of 2 to 5 μm. In the production method according to the present invention , the viscosity of the reaction solution in the temperature range of 95 to 98 ° C. is adjusted and controlled in the range of 2 × 10 ^{−2 to} 5.5 × 10 ⁻² Pa · s in the reaction step. By doing so, the standard deviation can be controlled to 1.3 μm or less (substantial lower limit value is 0.2 μm), more preferably 1.2 μm or less. The crosslinking degree, average molecular weight, molecular weight distribution, etc. of the amino resin are not particularly limited.
[0030]
As a method for taking out the amino resin particles from the reaction solution, a method for filtering and a method using a separator such as a centrifugal separator are simple, but are not particularly limited. In addition, you may wash | clean the amino resin particle after taking out from a reaction liquid as needed.
[0031]
The amino resin particles taken out through the separation step may be dried at a temperature of about 100 to 200 ° C., for example, but the drying temperature and the drying method are not particularly limited. The drying step may be completed, for example, when the water content of the amino resin particles is 3% by weight or less. Alternatively, the amino resin particles taken out through the separation step may be subjected to heat treatment for the purpose of further improving the solvent resistance, water resistance, and heat resistance of the amino resin particles simultaneously with drying, for example. . The processing temperature and the processing method are not particularly limited. Then, after the drying or heat treatment, particles having an average particle diameter of 10 μm or less, that is, fine particles can be obtained by performing steps such as pulverization (pulverization) and classification as necessary. In addition, since the amino resin particles obtained by the production method according to the present invention hardly aggregate each other, even when performing the pulverization step, the amino resin particles can be sufficiently pulverized only by applying a slight force (load). Can do.
[0032]
By the production method according to the present invention, it is possible to easily obtain amino resin particles that are sufficiently and uniformly colored, that is, the color tone of each particle is uniform, without causing variations among particles or reactions. The amino resin particles are excellent in solvent resistance, water resistance and heat resistance, and have high hardness. Therefore, the amino resin particles can be suitably used as, for example, polyolefins such as polyethylene and polypropylene, polyvinyl chloride, various rubbers, various paints, fillers for toners, rheology control agents, colorants and the like.
[0033]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these.
[0034]
[Example 1]
In a reaction vessel having a capacity of 10 L equipped with a reflux condenser, stirrer, thermometer, vibration viscometer (manufactured by MIVI ITS Japan; model name MIVI 6001), 3200 g (17.1 mol) of benzoguanamine as an amino compound and , 2810 g of formalin with a concentration of 37% by weight (formaldehyde 34.7 mol) and 10 g of sodium carbonate 10% by weight aqueous solution (0.01 mol of sodium carbonate) were charged, and the temperature was raised while stirring, and the reaction was carried out at 96 ° C .
[0035]
Then, when the viscosity of the reaction solution reached 4.5 × 10 ⁻² Pa · s (45 cP), the reaction solution was cooled to complete the reaction step. Thereby, the reaction liquid containing the amino resin precursor which is the initial condensate of benzoguanamine and formaldehyde was obtained.
[0036]
Next, 100 g of polyvinyl alcohol (manufactured by Kuraray Co., Ltd .; trade name: PVA205) as an emulsifier was added to a reaction kettle having a capacity of 10 L equipped with a reflux condenser, a homomixer (stirrer, manufactured by Special Machine Industries Co., Ltd.) and a thermometer. Was dissolved in 5150 g of water, and the temperature was raised to 75 ° C. with stirring. Then, after adding the above reaction liquid to the reaction kettle, while maintaining the temperature at 75 ° C., the contents are vigorously stirred at a rotational speed of 7000 rpm, so that the amino resin precursor is emulsified and the amino resin precursor is mixed. An emulsion having a concentration of 38.3% by weight was obtained. When the emulsion was measured with a multisizer, the average particle size (d50) of the amino resin precursor in the emulsion was 3.8 μm, and the standard deviation was 0.93 μm. The resulting emulsion was cooled to 30 ° C.
[0037]
Next, 7 g of Acid Red 52 as a water-soluble dye was dissolved in 350 g of pure water to prepare an aqueous solution. The concentration of the dye is approximately 2% by weight. And the prepared aqueous solution was added to the said emulsion, and it stirred for 5 minutes. Thereafter, an aqueous solution obtained by dissolving 40 g of dodecylbenzenesulfonic acid as a catalyst in 1200 g of pure water is added to the emulsion (the temperature of the content is 30 ° C.), and the mixture is stirred at 90 ° C./hr until it reaches 90 ° C. The temperature was raised at. And after reaching 90 degreeC, it hold | maintained at this temperature for 1 hour, and the amino resin precursor was condensed and hardened. Therefore, the reaction time is a total of 7 hours.
[0038]
After finishing the curing step, the colored amino resin particles according to the present invention were taken out from the reaction solution by filtering. The amino resin particles taken out were heat-treated at 150 ° C. for 3 hours, and then put into a mortar and crushed by applying light force with a pestle. Thereby, pink powdery amino resin particles were obtained. When the amino resin particles were measured with a multisizer, the average particle diameter (d50) was 3.9 μm, and the standard deviation was 1.05 μm. The main reaction conditions and results are summarized in Table 1.
[0039]
[Example 2]
By performing the reaction step and the emulsion step similar to those in Example 1, a white emulsion having an amino resin precursor concentration of 38.3 wt% was obtained. The average particle size of the amino resin precursor in the emulsion was 3.8 μm, and the standard deviation was 0.90 μm.
[0040]
Next, 7 g of Acid Red 52 as a water-soluble dye was dissolved in 150 g of pure water to prepare an aqueous solution. The concentration of the dye is approximately 4.5% by weight. And the amino resin particle of the pink powder form was obtained by performing the hardening process etc. similar to Example 1 except having added the said aqueous solution to the said emulsion. The average particle diameter of the comparative amino resin particles was 5.0 μm, and the standard deviation was 1.21 μm. The main reaction conditions and results are summarized in Table 1.
[0041]
[Comparative Example 1]
By performing the reaction step and the emulsion step similar to those in Example 1, a white emulsion having an amino resin precursor concentration of 38.3 wt% was obtained. The average particle diameter of the amino resin precursor in the emulsion was 3.61 μm, and the standard deviation was 0.91 μm.
[0042]
Next, except that 7 g of Acid Red 52 as a water-soluble dye was added directly (as it was), a pink powdery amino resin particle was obtained by performing the same curing step as in Example 1. . The average particle diameter of the comparative amino resin particles was 6.42 μm, and the standard deviation was 1.36 μm. The resulting amino resin particles were enlarged or agglomerated with each other, and therefore the particle diameters were uneven (the particle size distribution was wide). The main reaction conditions and results are summarized in Table 1.
[0043]
[Table 1]

[0044]
【The invention's effect】
As described above, the method for producing amino resin particles of the present invention is a reaction step in which an amino compound and formaldehyde are reacted to obtain a reaction solution containing an amino resin precursor; An emulsion step for obtaining an emulsion; a coloring step for adding an aqueous solution prepared by dissolving a dye in water to the emulsion; a curing step for adding a catalyst to the emulsion to cure the amino resin precursor in an emulsion state; It is the composition which includes.
[0045]
Moreover, the manufacturing method of the amino resin particle | grains of this invention is the structure which the density | concentration of the dye in aqueous solution exists in the range of 0.1 to 5 weight% as mentioned above.
[0046]
In the method for producing amino resin particles of the present invention, as described above, the amino compound contains at least 40% by weight of at least one compound selected from the group consisting of benzoguanamine, cyclohexanecarboguanamine, cyclohexenecarboguanamine, and melamine. It is the composition which is.
[0047]
As described above, the method for producing amino resin particles of the present invention has a configuration in which the ratio of formaldehyde to 1 mol of the amino compound is in the range of 2 to 3 mol.
[0048]
According to the above configuration, since an aqueous solution obtained by dissolving a dye in water is added to the emulsion, the dye is uniformly mixed in the emulsion and colored according to the addition amount, and for each particle or Coloring unevenness does not occur for each reaction. That is, there is an effect that it is possible to easily obtain amino resin particles that are sufficiently and uniformly colored, that is, the color tone of each particle is uniform, without causing variations for each particle or reaction.

Claims (5)

A reaction step in which an amino compound and formaldehyde are reacted to obtain a reaction solution containing an amino resin precursor;
An emulsion step of emulsifying the reaction solution to obtain an emulsion;
A coloring step of adding an aqueous solution prepared by dissolving a dye in water to an emulsion;
A curing step of curing the amino resin precursor in an emulsion state by adding a catalyst to the emulsion;
Including
The method for producing amino resin particles, wherein the viscosity of the reaction liquid in the temperature range of 95 to 98 ° C is in the range of 2 x 10 ^{-2 to} 5.5 x 10 ^-2 Pa · s. Add inorganic particles to the emulsion,
The method for producing amino resin particles according to claim 1, wherein the specific surface area of the inorganic particles is in the range of 50 to 400 m ² / g.   The method for producing amino resin particles according to claim 1 or 2, wherein the concentration of the dye in the aqueous solution is in the range of 0.1 to 5% by weight.   The said amino compound contains 40 weight% or more of at least 1 type of compounds chosen from the group which consists of a benzoguanamine, a cyclohexane carboguanamine, a cyclohexene carboguanamine, and a melamine, The any one of Claims 1-3 characterized by the above-mentioned. The manufacturing method of the amino resin particle | grains as described in any one of.   The ratio of formaldehyde with respect to 1 mol of amino compounds is in the range of 2-3 mol, The manufacturing method of the amino resin particle of any one of Claims 1-4 characterized by the above-mentioned.