JP7714872B2 - Method for producing and mixing the composition - Google Patents

Description

The present invention relates to a new mixing method that efficiently homogenizes liquids and powders, and a method for producing a composition using this mixing method.

Dissolving and homogenizing different components through stirring is an essential technology in all fields. In the manufacturing industry, if components that should be homogenized are in a non-uniform state, it is impossible to guarantee product quality, and the product will not be viable as an industrial product.
For example, in pharmaceuticals, threshold values are set for impurities that have adverse effects on the human body, but if the components are non-uniform, these values will fluctuate, making it impossible to determine whether the product quality is acceptable or not.
Furthermore, in materials for cutting-edge displays and semiconductors, if any components remain undissolved, they become foreign matter and cause defects during molding, significantly reducing yields in subsequent processes.

In particular, materials for semiconductors use a highly viscous liquid such as silicone resin as the main component (base polymer), which allows for stable dimensions during product molding after curing. Typically, a liquid with a different viscosity such as a reactive monomer or powdered additives such as a polymerization initiator or antioxidant are added to this base polymer and dissolved uniformly to produce the final varnish.
For this reason, research and development into technologies that enable efficient dissolution and homogenization by stirring when mixing high-viscosity liquids and low-viscosity liquids, or low-viscosity liquids and powders, is still ongoing, and many prior art technologies have been reported.

For example, turbine impellers with high shear force are suitable and widely used for stirring and dissolving powder in low-viscosity liquids (see, for example, Patent Document 1). However, the fluid flow pattern in turbine impellers is from the center of the impeller outward (radially), limiting the vertical ejection force. As a result, while they exhibit a high stirring effect in low-viscosity liquids, in high-viscosity liquids they only stir locally, resulting in insufficient ejection force and making overall homogenization impossible.

Japanese Unexamined Patent Publication No. 61-263622

An object of the present invention is to provide a new mixing method for efficiently homogenizing a liquid and a powder, and a method for producing a composition using the mixing method.
Another object of the present invention is to provide a mixing method and a method for producing a composition that enable high viscosity liquids, low viscosity liquids, and powders to be homogenized using a single stirring blade and stirring vessel.

After extensive research, the inventors discovered that the above-mentioned problems could be solved, and completed the present invention, which has the following gist:

That is, the present invention includes the following.
[1] A method for producing a composition, comprising a stirring and dissolving step of stirring a liquid and a powder from which coarse particles have been removed in a stirring tank provided with a ribbon impeller, by the ribbon impeller, and dissolving the powder in the liquid.
[2] The method for producing a composition according to [1], wherein the liquid is a highly viscous liquid.
[3] The method for producing the composition according to [1], further comprising, after the stirring and dissolving step, a stirring step of adding a second liquid having a lower viscosity than the first liquid to the stirring tank and stirring the second liquid with the ribbon impeller.
[4] The method for producing a composition according to [3], wherein the first liquid is a highly viscous liquid and the second liquid is a low viscous liquid.
[5] The method for producing a composition according to [1], wherein the liquid is a low-viscosity liquid.
[6] The method for producing the composition according to [1], further comprising, after the stirring and dissolving step, a stirring step of adding a second liquid having a higher viscosity than the first liquid to the stirring tank and stirring the second liquid with the ribbon impeller.
[7] The method for producing a composition according to [6], wherein the first liquid is a low-viscosity liquid and the second liquid is a high-viscosity liquid.
[8] The method for producing a composition according to any one of [1] to [7], wherein the powder contains a photopolymerization initiator.
[9] The method for producing a composition according to any one of [1] to [8], wherein the powder from which coarse particles have been removed is a powder from which coarse particles have been removed by classification.
[10] A mixing method comprising a stirring and dissolving step of stirring a liquid and a powder from which coarse particles have been removed in a stirring tank provided with a ribbon impeller, by the ribbon impeller, and dissolving the powder in the liquid.
[11] The mixing method according to [10], wherein the liquid is a highly viscous liquid.
[12] The mixing method according to [10], further comprising a stirring step of adding a second liquid having a lower viscosity than the first liquid to the stirring tank after the stirring and dissolving step, and stirring the second liquid with the ribbon impeller.
[13] The mixing method according to [12], wherein the first liquid is a high-viscosity liquid and the second liquid is a low-viscosity liquid.
[14] The mixing method according to [10], wherein the liquid is a low viscosity liquid.
[15] The mixing method according to [10], further comprising, after the stirring and dissolving step, a stirring step of adding a second liquid having a higher viscosity than the first liquid to the stirring tank and stirring the second liquid with the ribbon impeller.
[16] The mixing method according to [15], wherein the first liquid is a low-viscosity liquid and the second liquid is a high-viscosity liquid.
[17] The mixing method according to any one of [10] to [16], wherein the powder contains a photopolymerization initiator.
[18] The mixing method according to any one of [10] to [17], wherein the powder from which the coarse particles have been removed is a powder from which the coarse particles have been removed by classification.

According to the present invention, it is possible to provide a new mixing method for efficiently homogenizing a liquid and a powder, and a method for producing a composition using the mixing method.
Furthermore, the present invention can provide a mixing method and a method for producing a composition that enable high viscosity liquids, low viscosity liquids, and powders to be homogenized using a single stirring blade and stirring vessel.
According to the present invention, it is possible to efficiently produce existing compositions for semiconductor materials, display materials, basic chemical materials, pharmaceutical and agrochemical preparations, cosmetics, and foods. In addition, it is possible to efficiently produce compositions that have been difficult to homogenize using conventional methods (particularly compositions consisting of a highly viscous liquid and a powder).

FIG. 1 is a perspective view of an example of a ribbon wing.

The inventors have conducted extensive research to provide a new mixing method that efficiently homogenizes liquids and powders, a method for producing compositions using said mixing method, and a method for producing compositions that enables high-viscosity liquids, low-viscosity liquids, and powders to be homogenized using a single mixing blade and mixing vessel.

Generally, the action of stirring can be divided into two parts: the force (H) that shears the material and the discharge force (Q) that circulates the liquid.
If the stirring power is P, then P ∝ H × Q, and the shear force (H) and the discharge force (Q) have opposing effects. Therefore, for efficient dissolution and homogenization, it is necessary to select multiple stirring blades that are suitable for the combination of materials to be dissolved.

As mentioned above, the fluid flow pattern in the turbine blades is from the center of the blade outward (radially), limiting the vertical discharge force. As a result, while it is effective in low-viscosity liquids, in high-viscosity liquids it results in localized stirring, insufficient discharge force, and overall uniformity is impossible.

On the other hand, it is known that ribbon impellers, which have a large discharge force and can easily move the liquid up and down, are suitable for mixing and uniformly dissolving high-viscosity liquids and low-viscosity liquids (see, for example, Japanese Patent Application Laid-Open No. 6-154573). Double helical ribbon impellers are capable of mixing and uniformly dissolving liquids over a wide viscosity range.
However, when dissolving powder in a highly viscous liquid, the powder adheres to the agitator blades, causing them to rotate together, which does not promote dissolution sufficiently.In addition, because the powder accumulates inside the ribbon blades where the shear force is not sufficient, uniform dissolution between the solid (powder) and the liquid cannot be achieved.

Furthermore, instead of turbine or ribbon blades, mixing blades that integrate multiple mixing blades, such as paddle blades and gate blades, have been devised (see, for example, JP 9-108557 A), and devices that use multiple mixing shafts to increase mixing power and combine different mixing blades (see, for example, JP 4-215829 A). However, the former are applicable to a lower high viscosity range than ribbon blades, and are not suitable for high viscosity ranges such as silicone polymers, ranging from tens to millions of mPa·s. The latter require increased power consumption and more complex mixing blades and devices, resulting in increased operating, installation, and maintenance costs. This also leads to poorer cleanability within the tank, requiring large amounts of cleaning solvent for each campaign to prevent cross-contamination, increasing equipment cleaning costs.

In other words, a method for uniformly dissolving high-viscosity liquids, low-viscosity liquids, and powders using a single agitator and agitator tank has not been known until now. To avoid unnecessary consumption of agitation power, it is necessary to use an agitator tank for low-viscosity liquids and another for high-viscosity liquids, as shown in JP 11-140179 A. In the first step, powder is dissolved in a low-viscosity liquid in an agitator tank equipped with turbine blades that have excellent shear force to create a uniform solution. In the subsequent step, the homogeneous solution is poured into a high-viscosity liquid in another agitator tank equipped with ribbon blades that have excellent discharge force, and agitated to create the final homogeneous solution. However, this requires the use of multiple agitator blades and agitator tanks, which increases cleaning processes and significantly reduces production efficiency.

In light of the above, the present inventors have conducted extensive research and have found that when stirring a liquid and a powder using a ribbon impeller, by using powder from which coarse particles have been removed, it is possible to avoid the powder adhering to the stirring impeller and causing the powder to rotate together with the impeller, and it is also possible to prevent the powder from remaining inside the ribbon impeller and resulting in insufficient dissolution, and therefore it is possible to efficiently dissolve the powder in the liquid even when a ribbon impeller is used.
In other words, they discovered that the liquid and powder from which coarse particles have been removed can be efficiently homogenized by performing a stirring and dissolving process in which the liquid and powder are stirred by the ribbon impeller in a stirring tank equipped with ribbon impellers, and the powder is dissolved in the liquid.
The ribbon impeller is suitable for mixing and stirring high-viscosity liquids and low-viscosity liquids. Therefore, it was found that if, in the stirring and dissolving step, a high-viscosity liquid is first used together with powder from which coarse particles have been removed, and the liquid and powder are efficiently homogenized, and then a liquid with a lower viscosity than the high-viscosity liquid is added to the stirring vessel and stirred using the ribbon impeller, it is possible to homogenize a high-viscosity liquid, a low-viscosity liquid, and a powder using a single stirring impeller and stirring vessel.
Furthermore, in the stirring and dissolving process, the inventors discovered that if a low-viscosity liquid is first used together with the powder from which the coarse particles have been removed, and the liquid and powder are efficiently homogenized, and then a liquid with a higher viscosity than the low-viscosity liquid is added to the stirring tank and stirred using a ribbon impeller, it is possible to homogenize the high-viscosity liquid, the low-viscosity liquid, and the powder using a single stirring impeller and stirring tank.

In one embodiment of JP 2011-42746 A, a polymer solid having a specified particle size is added to a low-viscosity monomer in a single stirring tank and stirred to dissolve. However, the purpose of specifying the particle size of the polymer solid in this publication is to prevent clogging within the tank by reducing the terminal settling velocity of the polymer particles, and there is no mention of the effect that the particle size of the polymer solid has on the dissolution phenomenon itself.

<Mixing method and composition manufacturing method>
The mixing method of the present invention includes a stirring and dissolving step, and preferably includes a stirring step.
The method for producing the composition of the present invention includes stirring and dissolving steps, and preferably includes a stirring step.

<<Stirring and dissolving process>>
The stirring and dissolving step is not particularly limited as long as it is a step of stirring a liquid and a powder from which coarse particles have been removed by a ribbon impeller in a stirring tank provided with a ribbon impeller, and dissolving the powder in the liquid.

<<<Ribbon impeller and mixing vessel>>>
The ribbon impeller is an agitating impeller having a spirally twisted ribbon-shaped blade, and is also called a helical ribbon impeller.
In the description of the present invention, the ribbon blade and stirring blade do not refer only to the blade, but also to the entire part that rotates during stirring, including the stirring shaft (but excluding the stirring motor).

The number of spirally twisted ribbon-shaped blades (hereinafter, may be referred to as "ribbon-shaped blades") in the ribbon impeller is not particularly limited and may be one or two or more, but from the viewpoint of realizing more suitable stirring while having an appropriate number that makes cleaning after use easy, it is preferably 1 to 2.
The width and thickness of the ribbon-shaped blade are not particularly limited.
The material of the ribbon-shaped blade is not particularly limited as long as it is suitable for this type of application, and examples thereof include stainless steel.
The ribbon-shaped blade may be provided with a protruding portion protruding from the outer end, as shown in FIG. 1 of JP-A-2000-233122, for example.

The ribbon impeller has a stirring shaft in addition to a ribbon-shaped blade.
The stirring shaft may pass through the central axis of rotation of the helical ribbon impeller 3 from top to bottom, as in the stirring shaft 1 of the vertical reaction apparatus described in Figure 1(B) of JP-A-11-181086. In this embodiment, the ribbon-shaped blade (the helical ribbon impeller 3 of JP-A-11-181086) is fixed to the stirring shaft by, for example, a support rod extending perpendicularly from the stirring shaft.
The stirring shaft may be in an embodiment that does not lie on the central axis of rotation within the cylindrical space formed by the rotation of the helical ribbon impeller 3, as in the stirring shaft 1 of the vertical reaction apparatus described in Figure 1(A) of JP-A-11-181086. In this embodiment, the ribbon-shaped blade (the helical ribbon impeller 3 of JP-A-11-181086) is, for example, connected to the stirring shaft and fixed to a frame that is in contact with the ribbon-shaped blade.

Furthermore, the ribbon blade may have other blades in addition to the ribbon-shaped blade.
The ribbon blade may have, as another blade, for example, a band-like bottom ribbon blade (7) having a base end (a) connected to a helical ribbon blade (6) (ribbon-shaped blade in the present invention) and a tip end (c) that is approximately perpendicular to the bottom plate (3) and disposed near the center thereof, as described in claim 1 and FIG. 1 of JP-A-06-154573.
Furthermore, the ribbon blade may have, as another blade, a shear blade having a center of rotation concentric with the center of rotation of the flow blade (ribbon-shaped blade), as described in claim 1 and FIG. 1 of Patent Publication No. 2017/002905.

Examples of the ribbon blade include a V-shaped helical ribbon blade, a single helical ribbon blade, and a double helical ribbon blade.
The ribbon blade may be a commercially available product or may be a non-commercial product. Examples of commercially available stirring devices equipped with ribbon blades include SUPERBLEND (registered trademark) and NANOVisK (registered trademark) manufactured by Sumitomo Heavy Industries Process Equipment, Ltd.

An example of the ribbon blade is shown in Fig. 1. However, the ribbon blade used in the present invention is not limited to the ribbon blade shown in Fig. 1, as various forms are possible as described above.
The ribbon impeller in Fig. 1 has one stirring shaft 1, four support rods 2, two ribbon-shaped blades 3, and two bottom ribbon impellers 4. The stirring shaft 1 is located at the central axis of rotation of the two ribbon-shaped blades 3 and passes vertically through a cylindrical space formed by the rotation of the two ribbon-shaped blades 3. The two ribbon-shaped blades 3 are fixed to the stirring shaft 1 by four support rods 2 that extend vertically from the stirring shaft 1. One end of each of the two bottom ribbon impellers 4 is connected to the lower end of the ribbon-shaped blade 3, and the other end is connected near the lower end of the stirring shaft 1.

The material, size, shape, structure, etc. of the stirring vessel are not particularly limited.
The size of the stirring vessel is not particularly limited as long as it can accommodate the ribbon blades.
The material of the stirring vessel may be, for example, stainless steel or glass.
The cross-sectional shape of the inner peripheral wall of the stirring vessel is usually circular.
The tank volume of the stirring tank is not particularly limited, but is usually 0.5 L to 1000 L. The upper limit is preferably 500 L, more preferably 150 L, even more preferably 100 L, still more preferably 50 L, and even more preferably 30 L, from the viewpoint of achieving more uniform mixing with good reproducibility and minimizing the space required for the stirring tank. The lower limit is preferably 1 L, more preferably 10 L, and even more preferably 20 L, from the viewpoint of efficiently producing a mixture by larger-scale mixing.
The stirring vessel is usually a vertical stirring vessel having an opening at the top.

When a ribbon impeller is placed inside a mixing vessel, the distance between the outermost part of the rotating ribbon impeller and the inner wall of the mixing vessel is not particularly limited, but in one embodiment it is 1% to 20% of the inner diameter of the mixing vessel, and in another embodiment it is 1% to 10%.

The stirring power used to rotate the ribbon blade during the stirring and dissolving process is not particularly limited and can be selected appropriately depending on the amount of liquid and powder, the ratio of liquid to powder, the viscosity of the liquid, etc.

The time for the stirring and dissolving step is not particularly limited, but may be, for example, 0.5 to 10 hours, or 1 to 5 hours.
During the stirring and dissolving in the stirring and dissolving step, heating may be performed as needed within a range that does not cause deterioration of the components to be mixed, etc. The temperature during stirring and dissolving in the stirring and dissolving step may be, for example, 20°C to 60°C, 20°C to 50°C, or 25°C to 45°C.

The stirring device having a ribbon blade and a stirring tank used in the mixing method and composition manufacturing method may have other components such as baffles and baffle plates. However, from the perspective of making it easier to clean the stirring device after use, it is preferable that the stirring device does not have baffles or baffle plates.

<<<Liquid>>>
The liquid to be used is not particularly limited, and may be, for example, one or a mixture of two or more liquids that are used exclusively as organic solvents, or one or a mixture of two or more liquids that are used exclusively as organic materials, or a mixture thereof.

Liquids can be classified into high viscosity liquids and low viscosity liquids depending on the degree of viscosity.
The stirring Reynolds number Re is an index relating to the stirring state and viscosity, and is expressed as Re = inertial force / viscous force = ^d2 n ρ/μ (d = impeller diameter, n = rotation speed, ρ = liquid density, μ = viscosity). Generally, it is said that a laminar flow region occurs when Re < 50, a transition region occurs when 50 ≦ Re ≦ 1000, and a turbulent flow region occurs when 1000 < Re. If a liquid having a viscosity near the boundary between the laminar flow region and the transition region, where viscous forces are dominant, is defined as a highly viscous liquid in stirring, the highly viscous liquid refers to a viscous liquid with a viscosity of 10,000 mPa s or more, for example. In the present invention, a highly viscous liquid means a liquid with a viscosity of 10,000 mPa s or more.
In this regard, the viscosity of the highly viscous liquid used in the present invention is not particularly limited as long as it is 10,000 mPa·s or more, and may be, for example, 50,000 mPa·s or more, 100,000 mPa·s or more, or 1,000,000 mPa·s or more.
On the other hand, when a low-viscosity liquid is defined as a liquid having a viscosity near the boundary between the turbulent flow region, where inertial forces are dominant, and the transition region, the low-viscosity liquid refers to a viscous liquid having a viscosity of, for example, 1,000 mPa·s or less. In the present invention, a low-viscosity liquid also refers to a liquid having a viscosity of 1,000 mPa·s or less.
In this regard, the viscosity of the low-viscosity liquid used in the present invention is not particularly limited as long as it is 1,000 mPa·s or less, and may be, for example, 500 mPa·s or less, 100 mPa·s or less, or 10 mPa·s or less.
In the present invention, a medium-viscosity liquid may be defined as a viscous liquid between a high-viscosity liquid and a low-viscosity liquid. For example, a liquid having a viscosity of more than 1,000 mPa·s and less than 10,000 mPa·s may be defined as a medium-viscosity liquid. A medium-viscosity liquid may be used as needed when producing a composition.

The viscosity defined in the present invention can be measured under the following conditions.
・Apparatus: E-type viscometer TV-35H manufactured by Toki Sangyo Co., Ltd.
・Cone rotor type: 1°34 x R24
・Temperature: 25℃
・Rotation speed: 1 rpm
・Waiting time: 2 minutes

The liquid or highly viscous liquid may, for example, contain a polymer.
The liquid or low viscosity liquid contains, for example, a reactive monomer, a reactive additive, or an additive.
The polymer, reactive monomer, and reactive additive may have, for example, a polymerizable group. Examples of the polymerizable group include a radically polymerizable group, a cationically polymerizable group, and an anionically polymerizable group. Examples of the radically polymerizable group include a vinyl group, an acryloyl group, and a methacryloyl group.

<<<Powder>>>
The powder used in the stirring and dissolving step has previously had coarse particles removed.
The method for removing coarse particles from the powder is not particularly limited, and may be, for example, a method for removing coarse particles by classification, or a method for eliminating coarse particles from the powder by pulverizing the powder containing the coarse particles.
An example of a method for removing coarse particles by classification is sieving.
For example, the method for producing a composition and the method for mixing of the present invention may include a step of removing coarse particles from a powder containing coarse particles. The step of removing coarse particles may be, for example, a step of removing coarse particles by classification, or a step of pulverizing the powder containing coarse particles to remove the coarse particles from the powder.

The size of the powder is not particularly limited, but from the perspective of achieving suitable stirring and homogenization with good reproducibility, it is preferable that the powder be large enough to pass through a sieve with 3 mm openings, more preferably a sieve with 2 mm openings, and even more preferably a sieve with 1 mm openings.

The powder is not particularly limited as long as it can be dissolved in the liquid used, but for example, it is a powder of a material containing an organic component. Examples of powders of materials containing an organic component include various additives and polymerization initiators. Examples of polymerization initiators include radical polymerization initiators, cationic polymerization initiators, and anionic polymerization initiators. The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator.

One example of the effectiveness of the present invention is the stirring and dissolution of a powdered photopolymerization initiator. This is because photopolymerization initiators, due to their characteristics, often contain aromatic rings or heterocyclic rings as light-absorbing moieties, which tend to stack due to large intermolecular interactions, resulting in the formation of large powder particles at room temperature that are difficult to dissolve in liquid. Under these circumstances, photopolymerization initiators with improved solubility due to the addition of alkyl structures to the side chains and photopolymerization initiators pre-dissolved in liquid compounds have been developed. However, in both cases, the concentration of the active components (e.g., the active components for generating radicals) that initiate polymerization is reduced, which can lead to problems such as increased total costs and poor curing due to a slower polymerization rate.
In this regard, in the present invention, even a photopolymerization initiator that tends to stack and turn into a large particle powder at room temperature can be suitably dissolved in a liquid and suitably homogenized.

The powder photopolymerization initiator is not particularly limited, but examples thereof include alkylphenones, benzophenones, acylphosphine oxides, Michler's ketones, benzoyl benzoates, oxime esters, tetramethylthiuram monosulfides, and thioxanthones.
In particular, the effect of homogenization is exhibited in the case of a photocleavage-type photoradical polymerization initiator. Examples of photocleavage-type photoradical polymerization initiators include those described in "Latest UV Curing Technology" (page 159, published by Kazuhiro Takasu, published by Technical Information Association, Inc., published in 1991).
Commercially available photoradical polymerization initiators include, for example, OMNIRAD (registered trademark) 127, 184, 369, 369E, 379EG, 410, 500, 651, 819, 907, 2959, 4MBZ FLAKES, 4PBZ, BMS, BP FLAKES, DETX, EMK, ITX, OMBB, TPO-H, ESACURE (registered trademark) KIP100F, KIP150 (solidifies at low temperature), KIP160, 1001M, A1980, ONE, and 3644 [all manufactured by iGM Resins B.V.] Co., Ltd.], IRGACURE (registered trademark) 379, 784, 1800, 1870, OXE01, OXE02, OXE03, OXE04, Darocur (registered trademark) EDB [all manufactured by BASF Japan Ltd.], and the like.

An example of a combination of liquid and powder is a combination of a highly viscous liquid containing a polymer, a low-viscosity liquid containing a reactive monomer, and a powder of a material containing an organic component (e.g., a polymerization initiator).

The combination of liquid and powder is not particularly limited, but examples thereof include the following compositions in the polymerizable composition described in JP-A-2014-510159:
Highly viscous liquid: A reactive silicone compound obtained by polycondensing a diarylsilicic acid compound represented by formula [1] with a silicon compound selected from the compounds represented by formula [2] and formula [2b] in the presence of an acid or a base. Lowly viscous liquid: A compound having at least one polymerizable group selected from the group consisting of an alkenyl group and a (meth)acrylic group. Powder: A polymerization initiator (e.g., a photopolymerization initiator).
(In the formula,
Ar ¹ and Ar ² each independently represent a phenyl group optionally substituted by an alkyl group having 1 to 6 carbon atoms;
X represents a group capable of undergoing a hydrolytic condensation reaction;
Here, ^Ar3 represents a naphthyl group or an anthracyl group substituted with at least one group having a polymerizable double bond, or ^Ar3 represents a phenyl group substituted with at least one group having a polymerizable double bond other than a vinyl group, or a phenyl group substituted with at least two groups having a polymerizable double bond.

Other examples of the combination of liquid and powder include the following compositions in the composition for forming an optical waveguide described in Japanese Patent No. 6,156,673.
Highly viscous liquid: a reactive silicone compound consisting of a polycondensate of a diarylsilicic acid compound A represented by formula [1] and an alkoxysilicon compound B represented by formula [2], or a polycondensate of the diarylsilicic acid compound A, the alkoxysilicon compound B, and another polycondensable compound. Lowly viscous liquid: a di(meth)acrylate compound represented by formula [3]. Powder: a polymerization initiator (e.g., a photopolymerization initiator).
(In formula [1], Ar ¹ and Ar ² each independently represent a phenyl group which may be substituted with an alkyl group having 1 to 6 carbon atoms, a naphthyl group which may be substituted with an alkyl group having 1 to 6 carbon atoms, or a biphenyl group which may be substituted with an alkyl group having 1 to 6 carbon atoms.
In formula [2], ^Ar3 represents a phenyl group having at least one group having a polymerizable double bond, a naphthyl group having at least one group having a polymerizable double bond, or a biphenyl group having at least one group having a polymerizable double bond; ^R1s each independently represent a methyl group or an ethyl group; ^R2 represents a methyl group, an ethyl group, or a vinylphenyl group; and a represents 2 or 3.
In formula [3], ^R3 and ^R4 each independently represent a hydrogen atom or a methyl group, ^R5 represents a hydrogen atom, a methyl group, or an ethyl group, ^L1 and ^L2 each independently represent an alkylene group having 2 to 6 carbon atoms, and m and n each represent 0 or a positive integer such that m+n is 0 to 20.

Other examples of combinations of liquid and powder include photocurable resin compositions used for wafer-level lenses, such as those described in JP 2013-043982 A, which have the following compositions:
High viscosity liquid: Resin with an aliphatic cyclic hydrocarbon group and a weight-average molecular weight of 40,000 or less. Low viscosity liquid: Compound with an aliphatic cyclic hydrocarbon group and a polymerizable group. Powder: Compound that generates radicals or acids when exposed to actinic rays or radiation.

Another combination of liquid and powder may be the combination of liquid and powder in the photocurable composition for imprints used for wafer-level lenses described in WO2020/003863.
Among the liquids described in WO2020/003863, examples of low-viscosity liquids include compounds having at least two (meth)acryloyloxy groups per molecule and not containing an aromatic ring. Here, aromatic rings include carbon rings or heterocyclic rings that satisfy the Hückel rule, such as benzene, naphthalene, azulene, anthracene, tetracene, pentacene, phenanthrene, pyrene, furan, thiophene, pyrrole, pyrazole, imidazole, oxazole, thiazole, pyridine, pyridazine, pyrimidine, pyrazine and triazine. Therefore, not containing an aromatic ring means not containing a carbon ring or heterocyclic ring that satisfies the Hückel rule. Examples of the polyfunctional (meth)acrylate compound not containing an aromatic ring include ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ethoxylated glycerin tri(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, polyglycerin monoethylene oxide poly(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and neopentyl glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, 1,3-adamantanediol di(meth)acrylate, 1,4-cyclohexanedimethanol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and tris(2-acryloyloxyethyl) isocyanurate.

Commercially available polyfunctional (meth)acrylate compounds not containing an aromatic ring may be used, such as NK Ester A-200, A-400, A-600, A-1000, A-9300, A-9300-1CL, 1G, 2G, 3G, 4G, 9G, 14G, 23G, A-GLY-3E, A-GLY-9E, A-GLY-20E, A-TMPT-3EO, A-TMPT-9EO, ATM-4E, ATM-35E, A-DPH, A-TMPT, A-DCP, and A-HD-N. Examples include A-NOD-N, AD-TMP, A-DOG, TMPT, DCP, NPG, HD-N, NOD-N, and D-TMP (all manufactured by Shin-Nakamura Chemical Co., Ltd.), KAYARAD (registered trademark) DPHA, NPGDA, PET30, DPEA-12, PEG400DA, and RP-1040 (all manufactured by Nippon Kayaku Co., Ltd.), and M-210 and M-350 (all manufactured by Toagosei Co., Ltd.).

<<Mixing process>>
The mixing method and the method for producing the composition preferably further include a stirring step.
In one embodiment of the stirring step, after the stirring and dissolving step, a second liquid having a lower viscosity than the first liquid is added to the stirring tank and stirred with a ribbon impeller, where, for example, the first liquid is a highly viscous liquid and the second liquid is a low viscous liquid.
In another example of the stirring step, after the stirring and dissolving step, a second liquid having a higher viscosity than the first liquid is added to the stirring tank and stirred with a ribbon impeller, where the first liquid is a low-viscosity liquid and the second liquid is a high-viscosity liquid.

The stirring power used to rotate the ribbon impeller during the stirring process is not particularly limited and can be selected appropriately depending on the amounts of the first and second liquids, the viscosities of the first and second liquids, and other factors. Preferably, a speed reducer and inverter are used to adjust and set the stirring rotation speed favorable for dissolving and homogenizing the mixture through stirring, within a range that does not overload the motor. The results of a study on the stirring power required for ribbon impellers (non-patent document J. Chem. Eng. Japan, 15, 77-79 (1982)) are useful for reference.

The duration of the stirring step is not particularly limited, but may be, for example, 0.05 to 5 hours, or 0.1 to 3 hours.
The temperature during stirring in the stirring step is not particularly limited, but may be, for example, 20°C to 60°C, 20°C to 50°C, or 25°C to 45°C.

The ratio of liquid to powder to be stirred can be adjusted as needed depending on the solubility of the powder in the liquid. For example, the amount of liquid should be at least the amount that results in saturated solubility at the stirring temperature, preferably at least twice that amount, and more preferably at least five times that amount.

In a mixing method and a composition manufacturing method using a high viscosity liquid, a low viscosity liquid, and a powder, a case will be considered in which a polymerization initiator such as a photopolymerization initiator is used as the powder and a reactive monomer is used as the low viscosity liquid.
In such cases, when attempting to dissolve powder in a low-viscosity liquid, the stirring energy, heat of dissolution, etc., can cause the temperature in the system to rise (for example, to about 45°C), which can trigger a runaway polymerization reaction of the reactive monomer.On the other hand, this is unlikely to occur in a high-viscosity liquid.
Therefore, in the above case, it is preferable to first dissolve the powder in the high viscosity liquid in the stirring and dissolving process, then cool the liquid to make it safe, and then add the low viscosity liquid to the stirring tank in the stirring process, mix it, and produce the composition.

The present invention will be explained in more detail below using examples, but the present invention is not limited to the following examples.

The stirring and mixing conditions (1) and (2) using ribbon impeller A used in this example are shown below.
(1): Stirring and mixing conditions (1)
Equipment: Ribbon blade agitation mixer Tank volume: 10L
・Total length inside the tank: 450mm
・Tank inner diameter: 200mm
・Mixing blade: Ribbon blade A-1
・Total height of mixing blade: 390 mm
・Agitator blade outer diameter: 190 mm
・Agitator blade width: 20 mm
- Baffles, baffle plates: None - Material: SUS304 (stainless steel)
Agitator: Explosion-proof inverter motor with cyclo reducer, reduction ratio 1/21, output 0.4 kW, number of poles 4P, frequency 60 Hz, power supply 200 V

(2): Stirring and mixing conditions (2)
・Equipment: Ribbon blade stirring and mixing device Tank volume: 5L
・Total length inside the tank: 360mm
・Tank inner diameter: 150mm
・Mixing blade: Ribbon blade A-2
・Total height of mixing blade: 220 mm
・Agitator blade outer diameter: 140 mm
- Baffles, baffles: None - Materials: Tank is glass, stirring blades are SUS304
Stirrer: IKA Electronically Controlled Stirrer EUROSTAR200, Output 0.135 kW, Frequency 60 Hz, Power Supply 100 V

(3) Stirring blades and stirring vessels The combinations of stirring blades and stirring vessels used in this example are summarized in Table 1 below.

<<<<Explanation of Ribbon Wings>>
The anchor blade with a paddle is a blade having a shape similar to that of the anchor blade described in https://www.shipe.shi.co.jp/technology/mixing-lecture/basic001/index.html, in which the support rod that extends vertically from the rotation axis and supports the anchor-shaped blade at the bottom is replaced with a paddle.
The cross panel blade A is a blade having the same shape as the stirring blade (BENDLEAF blade) described in http://www.hakko-sangyo.co.jp/?page_id=542.
The cross panel blade B is a blade having a shape similar to that of the FULLZONE (second from the left) described in Fig. 2 of "Yoshito Kato et al., Mixing Power Requirements of Various Large Two-Paddle Blades, Collection of Papers on Chemical Engineering, Vol. 38, No. 3, pp. 139-143 (2012), https://nitech.repo.nii.ac.jp/?action=pages_view_main&active_action=repository_view_main_item_detail&item_id=5651&item_no=1&page_id=13&block_id=21".
The large panel blade is a blade having a shape similar to that of the Supermix MR203 described in Fig. 2 of "Yoshito Kato et al., Mixing Power Requirements of Various Large Two-Paddle Blades, Collection of Papers on Chemical Engineering, Vol. 38, No. 3, pp. 139-143 (2012), https://nitech.repo.nii.ac.jp/?action=pages_view_main&active_action=repository_view_main_item_detail&item_id=5651&item_no=1&page_id=13&block_id=21".
The paddle-equipped gate impeller is a blade having a shape similar to that of MAXBLEND described in Fig. 2 of "Yoshito Kato et al., Mixing Power Requirements of Various Large Two-Paddle Impellers, Collection of Papers on Chemical Engineering, Vol. 38, No. 3, pp. 139-143 (2012), https://nitech.repo.nii.ac.jp/?action=pages_view_main&active_action=repository_view_main_item_detail&item_id=5651&item_no=1&page_id=13&block_id=21".
Ribbon wings A-1, A-2, B, and C are herringbone wings having two ribbon-shaped blades.
Unlike the agitation shaft 1 of the vertical reaction apparatus described in Figure 1(A) of JP-A-11-181086, the agitation shafts of ribbon impellers A-1, A-2, and C do not lie on the central axis of rotation within the cylindrical space formed by the rotation of the helical ribbon impeller 3. The ribbon-shaped blade (helical ribbon impeller 3 of JP-A-11-181086) is connected to the agitation shaft and is fixed to a frame that is in contact with the ribbon-shaped blade.
The stirring shaft of the ribbon impeller B penetrates the central axis of rotation of the helical ribbon impeller 3 from top to bottom, like the stirring shaft 1 of the vertical reaction apparatus shown in FIG. 1(B) of JP-A-11-181086.
The ribbon blades B and C have bottom ribbon blades as described in claim 1 and FIG. 1 of Japanese Patent Application Laid-Open No. 06-154573.

(4) Viscosity Measurement Viscosity measurements were carried out under the following conditions. However, when the measurement temperature is also listed for the viscosity described below, the viscosity refers to the viscosity at the measurement temperature also listed.
・Apparatus: E-type viscometer TV-35H manufactured by Toki Sangyo Co., Ltd.
・Cone rotor type: 1°34 x R24
・Temperature: 25℃
・Rotation speed: 1 rpm
・Waiting time: 2 minutes

The abbreviations of the compounds have the following meanings.
STMS: trimethoxy(4-vinylphenyl)silane [manufactured by Shin-Etsu Chemical Co., Ltd.] Viscosity 2 mPa·s (25°C)
DDT: N-dodecyl mercaptan [manufactured by NOF Corporation] Viscosity 2 mPa s (25°C)
DOG: Dioxane glycol diacrylate [NK Ester A-DOG manufactured by Shin-Nakamura Chemical Co., Ltd.] Viscosity: 300 mPa·s (25°C)
DVB: Divinylbenzene [DVB-810, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., purity 81%] Viscosity 1 mPa s (25°C)
TPO: diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide [Omnirad (registered trademark) TPO-H, manufactured by iGM Resin Co., Ltd.]
(Equivalent to IRGACURE (registered trademark) TPO manufactured by BASF Japan Ltd.)
184: Hydroxycyclohexyl phenyl ketone [Omnirad (registered trademark) 184 manufactured by iGM Resin Co., Ltd.] (equivalent to IRGACURE (registered trademark) 184 manufactured by BASF Japan Ltd.)

[Homogeneous dissolution of high viscosity liquid and low viscosity liquid]
To confirm that the ribbon impeller has excellent uniform dissolving ability for high-viscosity liquids and low-viscosity liquids, the following Reference Examples 1 to 16 were carried out. In the following, unless the liquid temperature during stirring is specified, stirring was carried out at room temperature (25°C).

[Reference Example 1] Confirmation of the efficiency of uniform dissolution of high viscosity liquid and low viscosity liquid (ribbon blade A-2)
A ribbon impeller A-2 made of SUS304 and having a blade diameter of 140 mm and a total blade height of 220 mm was set in a 5 L round-bottom separable glass reaction vessel (inner diameter 150 mm, height 360 mm), and stirring was carried out under the above-mentioned stirring and mixing conditions (2).
4,299 g of starch syrup (colorless and transparent), which had been adjusted to a viscosity of 292,000 mPa s by adding ion-exchanged water, was gently poured into the container. Next, 96 g of an aqueous iodine solution (brown) (viscosity: 1 mPa s) was gently added as a coloring liquid to visually confirm the mixed state. The total height of the two separated liquid layers was 215 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA Corporation, was used as an agitator that drives agitating blades from the top of the vessel, and the rotation speed was adjusted so that the agitation power per unit volume was 4.2 kW/m ³ , and agitation was started.
The time required for the two liquids to dissolve was measured as 10 minutes, and the viscosity of the brown liquid after uniform dissolution was 81,370 mPa s. The results are shown in Table 2.

[Reference Example 2] Confirmation of the efficiency of uniform dissolution of high viscosity liquid and low viscosity liquid (ribbon blade B)
A ribbon impeller B made of SUS304 and having an impeller diameter of 125 mm and an impeller total height of 140 mm was set in a 3 L round-bottom separable glass reaction vessel (inner diameter 130 mm, height 310 mm).
3005 g of starch syrup (colorless and transparent), which had been adjusted to a viscosity of 239,400 mPa s by adding ion-exchanged water, was gently poured into the container. Subsequently, 69 g of an aqueous iodine solution (brown) (viscosity: 1 mPa s) was gently added as a coloring liquid to visually confirm the mixed state. The total height of the liquid that separated into two layers was 210 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA Corporation, was used as an agitator that drives agitating blades from the top of the vessel, and the rotation speed was adjusted so that the agitation power per unit volume was 4.2 kW/m ³ , and agitation was started.
The time required for the two liquids to dissolve was measured as 10 minutes, and the viscosity of the brown liquid after uniform dissolution was 80100 mPa s. The results are shown in Table 2.

[Reference Example 3] Confirmation of the efficiency of uniform dissolution of high viscosity liquid and low viscosity liquid (ribbon blade C)
A ribbon impeller C made of SUS304 and having a blade diameter of 120 mm and a total blade height of 180 mm was set in a 2 L round-bottom separable glass reaction vessel (inner diameter 130 mm, height 220 mm).
2634 g of starch syrup (colorless and transparent), which had been adjusted to a viscosity of 292,000 mPa s by adding ion-exchanged water, was gently poured into the container. 61 g of an aqueous iodine solution (brown, viscosity: 1 mPa s) was then gently added as a coloring liquid to visually confirm the mixed state. The total height of the two separated liquid layers was 180 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA Corporation, was used as an agitator that drives agitating blades from the top of the vessel, and the rotation speed was adjusted so that the agitation power per unit volume was 4.2 kW/m ³ , and agitation was started.
The time required for the two liquids to dissolve was measured as 20 minutes, which was the time it took for the entire liquid to be visually colored uniformly brown. The viscosity of the brown liquid after uniform dissolution was 60,300 mPa s. The results are shown in Table 2.

[Reference Examples 4 to 8] Confirmation of the efficiency of uniform dissolution of high viscosity liquid and low viscosity liquid (other than ribbon impeller)
The stirring blades were changed from the ribbon blades used in Reference Examples 1 to 3 to other blades shown in Table 1. The mixing vessel was changed to a 2 L round-bottom separable glass reaction vessel (inner diameter 120 mm, height 170 mm). The efficiency of uniform dissolution of high-viscosity and low-viscosity liquids was confirmed in the same manner as in Reference Example 1, with the stirring power per unit volume kept the same. As a result, as shown in Table 3, it was confirmed that a longer stirring time was required than with the ribbon blade, and that the efficiency of uniform dissolution of high-viscosity and low-viscosity liquids was poor.

[Reference Example 9] Confirmation of the efficiency of uniform dissolution of high viscosity liquid and low viscosity liquid (ribbon blade A-2)
After carrying out Reference Example 1, the following experiment was carried out using the same mixing and stirring apparatus.
To the brown liquid having a viscosity of 81,370 mPa s obtained in Reference Example 1, 266 g of an aqueous sodium thiosulfate solution (viscosity: 1 mPa s) was gently added as a decolorizing liquid for visually confirming the mixed state. The total height of the liquid separated into two layers was 230 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA Corporation, was used as an agitator with an agitating blade driven from the top of the vessel, and the rotation speed was adjusted so that the agitating power per unit volume was 3.4 kW/m ³ , and agitation was started.
The time required for the two liquids to dissolve was measured as 10 minutes, which was the time required for the entire liquid to be completely and uniformly decolorized by visual inspection. The viscosity of the colorless, transparent liquid after uniform dissolution was 7,880 mPa s. The results are shown in Table 4.

[Reference Example 10] Confirmation of the efficiency of uniform dissolution of high viscosity liquid and low viscosity liquid (ribbon blade B)
After carrying out Reference Example 2, the following experiment was carried out using the same mixing and stirring apparatus.
To the brown liquid having a viscosity of 80100 mPa s obtained in Reference Example 2, 218 g of an aqueous sodium thiosulfate solution (viscosity: 1 mPa s) was gently added as a decolorizing liquid for visually confirming the mixed state. The total height of the liquid separated into two layers was 225 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA Corporation, was used as an agitator with an agitating blade driven from the top of the vessel, and the rotation speed was adjusted so that the agitating power per unit volume was 3.4 kW/m ³ , and agitation was started.
The time required for the two liquids to dissolve was measured as 10 minutes, which was the time required for the entire liquid to be completely and uniformly decolorized by visual inspection. The viscosity of the colorless, transparent liquid after uniform dissolution was 5677 mPa s. The results are shown in Table 4.

[Reference Example 11] Confirmation of the efficiency of uniform dissolution of high viscosity liquid and low viscosity liquid (ribbon blade C)
After carrying out Reference Example 3, the following experiment was carried out using the same mixing and stirring apparatus.
To the brown liquid having a viscosity of 60,300 mPa s obtained in Reference Example 3, 191 g of an aqueous sodium thiosulfate solution (viscosity: 1 mPa s) was gently added as a decolorizing liquid for visually confirming the mixed state. The total height of the liquid separated into two layers was 195 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA Corporation, was used as an agitator with an agitating blade driven from the top of the vessel, and the rotation speed was adjusted so that the agitating power per unit volume was 3.4 kW/m ³ , and agitation was started.
The time required for the two liquids to dissolve was measured as 15 minutes, which was the time required for the entire liquid to be completely and uniformly decolorized by visual inspection. The viscosity of the colorless, transparent liquid after uniform dissolution was 6,540 mPa s. The results are shown in Table 4.

[Reference Examples 12 to 16] Confirmation of the efficiency of uniform dissolution of high viscosity liquid and low viscosity liquid (other than ribbon impeller)
After each of Reference Examples 4 to 8 was carried out, the following experiments were carried out using the same mixing and stirring apparatus.
The brown liquids (viscosity: approximately 80,000 mPa s) obtained in each of Reference Examples 4 to 8 were used, and an aqueous sodium thiosulfate solution was gently added as a decolorizing solution to visually confirm the mixed state. As in Reference Example 9, the efficiency of uniform dissolution of high-viscosity and low-viscosity liquids was confirmed with the same stirring power per unit volume. As a result, as shown in Table 5, it was confirmed that longer stirring times were required than with the ribbon impeller, and that the efficiency of uniform dissolution of high-viscosity and low-viscosity liquids was poor.

The results of Reference Examples 1 to 16 clearly show that the ribbon impeller is superior in stirring and dissolving high viscosity liquids and low viscosity liquids.
The following examples and comparative examples in which high viscosity liquids and powders, and low viscosity liquids are stirred and dissolved were carried out by selecting ribbon blade A-1 or A-2.

Example 1: Stirring and uniformly dissolving a highly viscous liquid and a powder, and stirring and uniformly dissolving a low viscosity liquid in the same tank (ribbon impeller A-2)
Stirring was carried out under the above-mentioned stirring and mixing conditions (2). Specifically, the conditions were as follows.
A ribbon impeller A-2 made of SUS304 and having an impeller diameter of 140 mm and an impeller total height of 220 mm was set in a 5 L round-bottom separable glass reaction vessel (inner diameter 150 mm, height 360 mm).
2260 g of silicone resin with a viscosity of approximately 50,000 mPa·s at 25° C. was gently placed in the container. Subsequently, 70 g of undersized TPO powder, which had been previously classified using a sieve with 250 μm openings, was gently added thereto so as not to create powder.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA, was used as an agitator with an agitating blade driven from the top of the vessel, and agitation was started at 10 rpm.
A 5 L round-bottom separable glass reaction vessel was heated in an oil bath to adjust the temperature to 40 to 45° C., and the stirring speed was increased to 65 rpm, followed by stirring for a total of 3 hours.
To prevent polymerization of the DVB and STMS that were subsequently added, heating was stopped, the mixture was cooled, and stirring was stopped. After air bubbles that had become trapped in the mixture during stirring were removed, visual inspection revealed that the TPO had completely dissolved, with no residual TPO remaining.
To this was gently added 70 g of DVB, a low-viscosity liquid with a viscosity of 1 mPa s at 25°C, and the mixture was stirred for 2 hours at 50 rpm at 20 to 25°C. Subsequently, 12 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 23 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, were gently added, and the mixture was stirred for 2 hours at 60 rpm at 20 to 25°C.
After stirring was stopped, the mixed liquid was sampled from two locations in the tank and the viscosity was measured. The results showed that the viscosities at 25°C were 5001 mPa·s and 4848 mPa·s, and there was no variation in the viscosities, confirming that the high-viscosity liquid and the low-viscosity liquid were uniformly dissolved.
The stirred solution was then filtered through a flat filter medium with a pore size of 3 μm (metal fiber sheet manufactured by ADVANTEC Co., Ltd.) Observation of the surface of the filter medium after filtration revealed that the TPO had completely dissolved, with no undissolved residue.
In conclusion, it was confirmed that the high viscosity liquid, powder, and low viscosity liquid were completely and uniformly dissolved. The results are shown in Table 6.

Example 2: Stirring and uniformly dissolving a highly viscous liquid and a powder, and stirring and uniformly dissolving a low viscosity liquid in the same tank (ribbon impeller A-2)
Stirring was carried out under the above-mentioned stirring and mixing conditions (2). Specifically, the conditions were as follows.
A ribbon impeller A-2 made of SUS304 and having an impeller diameter of 140 mm and an impeller total height of 220 mm was set in a 5 L round-bottom separable glass reaction vessel (inner diameter 150 mm, height 360 mm).
2,170 g of silicone resin with a viscosity of approximately 300,000 mPa s at 25° C. was gently placed in this container. Subsequently, 100 g of TPO powder that had previously been classified using a sieve with 250 μm openings, and 67 g of 184 powder that had been obtained in the same manner but that had not yet been sieved, were gently added thereto, taking care not to create powder.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA, was used as an agitator with an agitating blade driven from the top of the vessel, and agitation was started at 6 rpm.
A 5 L round-bottom separable glass reaction vessel was heated in an oil bath to adjust the temperature to 40 to 45° C., and the stirring speed was increased to 60 rpm, followed by stirring for a total of 3 hours.
To prevent polymerization of DOG and STMS, the mixture was cooled and the stirring was stopped. After the air bubbles trapped in the mixture were removed, the mixture was visually inspected and found to be completely dissolved with no residue.
To this was gently added 1170 g of DOG, a low-viscosity liquid with a viscosity of 300 mPa s at 25°C, and the mixture was stirred for 2 hours at 50 rpm at 20 to 25°C. Subsequently, 17 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 33 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, were gently added, and the mixture was stirred for 2 hours at 60 rpm at 20 to 25°C.
After stirring was stopped, the mixed liquid was sampled from two locations in the tank and the viscosity was measured. The results showed that the viscosities at 25°C were 2357 mPa·s and 2313 mPa·s, and there was no variation in the viscosities, confirming that the high-viscosity liquid and the low-viscosity liquid were uniformly dissolved.
The stirred solution was then filtered through a flat filter medium with a pore size of 3 μm (metal fiber sheet manufactured by ADVANTEC Co., Ltd.) Observation of the surface of the filter medium after filtration revealed that TPO and 184 had completely dissolved, with no undissolved residues.
In conclusion, it was confirmed that the high viscosity liquid, powder, and low viscosity liquid were completely and uniformly dissolved. The results are shown in Table 6.

Example 3: Stirring and uniformly dissolving a highly viscous liquid and a powder, and stirring and uniformly dissolving a low viscosity liquid in the same tank (ribbon impeller A-1)
Stirring was carried out under the above-mentioned stirring and mixing conditions (1). Specifically, the conditions were as follows.
6,790 g of silicone resin with a viscosity of approximately 50,000 mPa s at 25° C. was slowly charged into a 10 L manufacturing agitator mixer (ribbon blade A-1). Subsequently, 211 g of undersized TPO powder, which had been previously classified using a sieve with 1 mm openings, was slowly added thereto, taking care not to create powder.
Stirring was started using an explosion-proof inverter motor-equipped cyclo reducer as an agitator that drives a stirring blade from the top of the apparatus, with a reduction ratio of 1/21, an output of 0.4 kW, 4 poles, a frequency of 60 Hz, and a power supply of 200 V. The internal temperature was adjusted to 40 to 45°C by heating from the jacket, and the stirring speed was increased to 110 rpm, and stirring was continued for a total of 3 hours.
To prevent polymerization of the DVB and STMS that were subsequently added, heating was stopped, the mixture was cooled, and stirring was stopped. After air bubbles that had become trapped in the mixture during stirring were removed, visual inspection revealed that the TPO had completely dissolved, with no residual TPO remaining.
To this was gently added 205 g of DVB, a low-viscosity liquid with a viscosity of 1 mPa s at 25°C, and the mixture was stirred for 2 hours at 130 rpm at 20 to 25°C. Subsequently, 33 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 67 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, were gently added, and the mixture was stirred for 3 hours at 130 rpm at 20 to 25°C.
After stirring was stopped, the mixed liquid was sampled from three locations in the tank and the viscosity was measured. The viscosities at 25°C were 5,310 mPa·s, 5,330 mPa·s, and 5,313 mPa·s, and the consistency of the viscosities confirmed that the high-viscosity liquid and the low-viscosity liquid were uniformly dissolved.
The stirred solution was then filtered through a flat filter medium with a pore size of 3 μm (Microscreen E, manufactured by 3M Co.). When the surface of the filter medium was observed after filtration, it was found that the TPO had completely dissolved, with no undissolved residue remaining.
In conclusion, it was confirmed that the high viscosity liquid, powder, and low viscosity liquid were completely and uniformly dissolved. The results are shown in Table 6.

Example 4: Stirring and uniformly dissolving a highly viscous liquid and a powder, and stirring and uniformly dissolving a low viscosity liquid in the same tank (ribbon impeller A-1)
Stirring was carried out under the above-mentioned stirring and mixing conditions (1). Specifically, the conditions were as follows.
6067 g of silicone resin with a viscosity of approximately 300,000 mPa s at 25° C. was slowly charged into a 10 L manufacturing agitator mixer (ribbon blade A-1). Subsequently, 280 g of TPO powder that had been previously classified using a sieve with 1 mm openings, and 187 g of 184 powder that had been obtained in the same manner but that had been sieved, were slowly added thereto, taking care not to create powder.
Stirring was started using an explosion-proof inverter motor-equipped cyclo reducer as an agitator that drives a stirring blade from the top of the device, with a reduction ratio of 1/21, an output of 0.4 kW, 4 poles, a frequency of 60 Hz, and a power supply of 200 V. The internal temperature was adjusted to 40 to 45°C by heating from the jacket, and the stirring speed was increased to 110 rpm, and stirring was continued for a total of 2 hours.
To prevent polymerization of DOG and STMS, the mixture was cooled and the stirring was stopped. After the air bubbles trapped in the mixture were removed, the mixture was visually inspected and found to be completely dissolved with no residue.
To this was gently added 1170 g of DOG, a low-viscosity liquid with a viscosity of 300 mPa s at 25°C, and the mixture was stirred for 3 hours at 130 rpm at 20 to 25°C. Subsequently, 45 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 89 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, were gently added, and the mixture was stirred for 2 hours at 130 rpm at 20 to 25°C.
After stirring was stopped, the mixed liquid was sampled from three locations in the tank and the viscosity was measured. The viscosities at 25°C were 2152 mPa·s, 2150 mPa·s, and 2151 mPa·s, and the consistency of the viscosities confirmed that the high-viscosity liquid and the low-viscosity liquid were uniformly dissolved.
The stirred solution was then filtered through a flat filter medium with a pore size of 3 μm (Microscreen E, manufactured by 3M Co.). When the surface of the filter medium was observed after filtration, it was found that TPO and 184 had completely dissolved, with no residue remaining.
In conclusion, it was confirmed that the high viscosity liquid, powder, and low viscosity liquid were completely and uniformly dissolved. The results are shown in Table 6.

Example 5: Stirring and uniformly dissolving a highly viscous liquid and a powder, and stirring and uniformly dissolving a low viscosity liquid in the same tank (ribbon impeller A-1)
Stirring was carried out under the above-mentioned stirring and mixing conditions (1). Specifically, the conditions were as follows.
8,120 g of silicone resin with a viscosity of approximately 50,000 mPa s at 25° C. was slowly added to a 10 L manufacturing agitator mixer (ribbon blade A-1). Subsequently, 250 g of undersized TPO powder, which had been previously classified using a sieve with 1 mm openings, was slowly added thereto, taking care not to create powder.
Stirring was started using an explosion-proof inverter motor-equipped cyclo reducer as an agitator that drives a stirring blade from the top of the device, with a reduction ratio of 1/21, an output of 0.4 kW, 4 poles, a frequency of 60 Hz, and a power supply of 200 V. The internal temperature was adjusted to 35 to 40°C by heating from the jacket, and the stirring speed was increased to 110 rpm, and stirring was continued for a total of 1 hour.
To prevent polymerization of the DVB and STMS that were subsequently added, heating was stopped, the mixture was cooled, and stirring was stopped. After air bubbles that had become trapped in the mixture during stirring were removed, visual inspection revealed that the TPO had completely dissolved, with no residual TPO remaining.
To this was gently added 251 g of DVB, a low-viscosity liquid with a viscosity of 1 mPa s at 25°C, and the mixture was stirred for 1 hour at 130 rpm at 20 to 25°C. Subsequently, 41 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 83 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, were gently added, and the mixture was stirred for 1 hour at 130 rpm at 20 to 25°C.
After stirring was stopped, the mixed liquid was sampled from three locations in the tank and the viscosity was measured. The viscosities at 25°C were 5052 mPa·s, 5055 mPa·s, and 5044 mPa·s, and the consistency of the viscosities confirmed that the high-viscosity liquid and the low-viscosity liquid were uniformly dissolved.
The stirred solution was then filtered through a flat filter medium with a pore size of 3 μm (Microscreen E, manufactured by 3M Co.). When the surface of the filter medium was observed after filtration, it was found that the TPO had completely dissolved, with no undissolved residue remaining.
In conclusion, it was confirmed that the high viscosity liquid, powder, and low viscosity liquid were completely and uniformly dissolved. The results are shown in Table 6.

Example 6: Stirring and uniformly dissolving a highly viscous liquid and a powder, and stirring and uniformly dissolving a low viscosity liquid in the same tank (ribbon impeller A-1)
Stirring was carried out under the above-mentioned stirring and mixing conditions (1). Specifically, the conditions were as follows.
6,499 g of silicone resin with a viscosity of approximately 300,000 mPa s at 25° C. was slowly charged into a 10 L manufacturing agitator mixer (ribbon blade A-1). Subsequently, 300 g of TPO powder that had been previously classified using a sieve with 1 mm openings and 200 g of 184 powder that had been obtained in the same manner were slowly added thereto, taking care not to create powder.
Stirring was started using an explosion-proof inverter motor-equipped cyclo reducer as an agitator that drives a stirring blade from the top of the device, with a reduction ratio of 1/21, an output of 0.4 kW, 4 poles, a frequency of 60 Hz, and a power supply of 200 V. The internal temperature was adjusted to 40 to 45°C by heating from the jacket, and the stirring speed was increased to 110 rpm, and stirring was continued for a total of 1 hour.
To prevent polymerization of DOG and STMS, the mixture was cooled and the stirring was stopped. After the air bubbles trapped in the mixture were removed, the mixture was visually inspected and found to be completely dissolved with no residue.
To this was gently added 3466 g of DOG, a low-viscosity liquid with a viscosity of 300 mPa s at 25°C, and the mixture was stirred at 130 rpm for 1 hour at 20 to 25°C. Subsequently, 49 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 99 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, were gently added, and the mixture was stirred at 130 rpm for 1 hour at 20 to 25°C.
After stirring was stopped, the mixed liquid was sampled from three locations in the tank and the viscosity was measured. The viscosities at 25°C were 2231 mPa·s, 2241 mPa·s, and 2240 mPa·s, and there was no variation in the viscosities, confirming that the high-viscosity liquid and the low-viscosity liquid were uniformly dissolved.
The stirred solution was then filtered through a flat filter medium with a pore size of 3 μm (Microscreen E, manufactured by 3M Co.). When the surface of the filter medium was observed after filtration, it was found that TPO and 184 had completely dissolved, with no residue remaining.
In conclusion, it was confirmed that the high viscosity liquid, powder, and low viscosity liquid were completely and uniformly dissolved. The results are shown in Table 6.

Example 7: Stirring and uniformly dissolving a highly viscous liquid and a powder, and stirring and uniformly dissolving a low viscosity liquid in the same tank (ribbon impeller A-1)
Stirring was carried out under the above-mentioned stirring and mixing conditions (1). Specifically, the conditions were as follows.
5,948 g of silicone resin with a viscosity of approximately 50,000 mPa s at 25° C. was slowly added to a 10 L manufacturing agitator mixer (ribbon blade A). Next, 184 g of undersized TPO powder, which had been previously classified using a sieve with 1 mm openings, was slowly added thereto, taking care not to create powder.
Stirring was started using an explosion-proof inverter motor-equipped cyclo reducer as an agitator that drives a stirring blade from the top of the device, with a reduction ratio of 1/21, an output of 0.4 kW, 4 poles, a frequency of 60 Hz, and a power supply of 200 V. The internal temperature was adjusted to 40 to 45°C by heating from the jacket, and the stirring speed was increased to 110 rpm, and stirring was continued for a total of 1 hour.
To prevent polymerization of the DVB and STMS that were subsequently added, heating was stopped, the mixture was cooled, and stirring was stopped. After air bubbles that had become trapped in the mixture during stirring were removed, visual inspection revealed that the TPO had completely dissolved, with no residual TPO remaining.
To this was gently added 182 g of DVB, a low-viscosity liquid with a viscosity of 1 mPa s at 25°C, and the mixture was stirred for 1 hour at 130 rpm at 20 to 25°C. Subsequently, 30 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 60 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, were gently added, and the mixture was stirred for 1 hour at 130 rpm at 20 to 25°C.
After stirring was stopped, the mixed liquid was sampled from three locations in the tank and the viscosity was measured. The viscosities at 25°C were 5531 mPa·s, 5519 mPa·s, and 5503 mPa·s, and the consistency of the viscosities confirmed that the high-viscosity liquid and the low-viscosity liquid were uniformly dissolved.
The stirred solution was then filtered through a flat filter medium with a pore size of 3 μm (Microscreen E, manufactured by 3M Co.). When the surface of the filter medium was observed after filtration, it was found that the TPO had completely dissolved, with no undissolved residue remaining.
In conclusion, it was confirmed that the high viscosity liquid, powder, and low viscosity liquid were completely and uniformly dissolved. The results are shown in Table 6.

Example 8: Stirring and uniformly dissolving a highly viscous liquid and a powder, and stirring and uniformly dissolving a low viscosity liquid in the same tank (ribbon impeller A-1)
Stirring was carried out under the above-mentioned stirring and mixing conditions (1). Specifically, the conditions were as follows.
6,933 g of silicone resin with a viscosity of approximately 300,000 mPa s at 25° C. was slowly charged into a 10 L manufacturing agitator mixer (ribbon blade A-1). Subsequently, 320 g of TPO powder that had been previously classified using a sieve with 2 mm openings, and 213 g of 184 powder that had been obtained in the same manner but that had been sieved, were slowly added thereto, taking care not to create powder.
Stirring was started using an explosion-proof inverter motor-equipped cyclo reducer as an agitator that drives a stirring blade from the top of the device, with a reduction ratio of 1/21, an output of 0.4 kW, 4 poles, a frequency of 60 Hz, and a power supply of 200 V. The internal temperature was adjusted to 40 to 45°C by heating from the jacket, and the stirring speed was increased to 110 rpm, and stirring was continued for a total of 1 hour.
To prevent polymerization of DOG and STMS, which were subsequently added, heating was stopped, the mixture was cooled, and stirring was stopped. After air bubbles trapped in the mixture during stirring were removed, visual inspection revealed that most of the TPO and 184 had dissolved, with only a small amount remaining.
To this was gently added 3709 g of DOG, a low-viscosity liquid with a viscosity of 300 mPa s at 25°C, and the mixture was stirred at 130 rpm for 1 hour at 20 to 25°C. Subsequently, 53 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 106 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, were gently added, and the mixture was stirred at 130 rpm for 1 hour at 20 to 25°C.
After stirring was stopped, the mixed liquid was sampled from three locations in the tank and the viscosity was measured. The viscosities at 25°C were 2303 mPa·s, 2295 mPa·s, and 2288 mPa·s, and there was no variation in the viscosities, confirming that the high-viscosity liquid and the low-viscosity liquid were uniformly dissolved.
The stirred solution was then filtered through a flat filter medium with a pore size of 3 μm (Microscreen E, manufactured by 3M Co.). Observation of the surface of the filter medium after filtration revealed that TPO and 184 had almost completely dissolved, with only a small amount remaining undissolved.
In conclusion, it was confirmed that the high viscosity liquid, powder, and low viscosity liquid were dissolved almost completely and uniformly. The results are shown in Table 6.

*The upper limit of temperature when mixing highly viscous liquid and powder is 45°C.

[Comparative Example 1] Confirmation of particle size that makes stirring and dissolving in highly viscous liquid difficult (ribbon blade A-2)
Stirring was carried out under the above-mentioned stirring and mixing conditions (2). Specifically, the conditions were as follows.
A ribbon impeller A-2 made of SUS304 and having an impeller diameter of 140 mm and an impeller total height of 220 mm was set in a 5 L round-bottom separable glass reaction vessel (inner diameter 150 mm, height 360 mm).
1,114 g of silicone resin with a viscosity of approximately 50,000 mPa·s at 25°C was gently placed in this container. Next, 35 g of DVB, a low-viscosity liquid with a viscosity of 1 mPa·s at 25°C, and 38 g of untreated TPO powder were gently added. The untreated TPO powder contained clumps with a maximum total length of approximately 15 to 60 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA, was used as an agitator with an agitating blade driven from the top of the vessel, and agitation was started at 6 rpm.
A 5 L round-bottom separable glass reaction vessel was heated in an oil bath to adjust the temperature to 50 to 60° C. Since the powder was difficult to dissolve, the stirring speed was increased to 140 rpm while monitoring the situation, and stirring was continued for a total of 3 hours.
Heating was stopped, and the mixture was cooled to 20-25°C, and stirring was then stopped. After the air bubbles that had become trapped in the mixture during stirring were released, visual inspection revealed that the TPO had not completely dissolved, with clear residual TPO remaining. At this point, the viscosity of the mixture had decreased to approximately 7,400 mPa s.
To this was gently added 6 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25° C., and 13 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25° C., and the mixture was stirred at 50 rpm for 4 hours at 20-25° C. After stirring, the liquid was filtered through a flat filter medium, and when the surface of the filter medium was observed, it was found that the TPO had not completely dissolved, with residual TPO remaining.
In conclusion, it was confirmed that it is difficult to completely dissolve untreated TPO in high viscosity liquids and low viscosity liquids even when the stirring speed is increased and the mixture is stirred for a long time at a high temperature. The results are shown in Table 7.

Instead of Comparative Example 1, when mixing was carried out in the same manner as in Example 1, except that the TPO that had been previously classified using a sieve with 250 μm openings in Example 1 was replaced with unclassified TPO (TPO containing clumps with a maximum total length of approximately 15 to 60 mm), residual TPO was confirmed, resulting in the same results as in Comparative Example 1.

[Comparative Example 2] Confirmation of particle size that makes stirring and dissolving in highly viscous liquid difficult (ribbon blade A-2)
Stirring was carried out under the above-mentioned stirring and mixing conditions (2). Specifically, the conditions were as follows.
A ribbon impeller A-2 made of SUS304 and having an impeller diameter of 140 mm and an impeller total height of 220 mm was set in a 5 L round-bottom separable glass reaction vessel (inner diameter 150 mm, height 360 mm).
732 g of silicone resin with a viscosity of approximately 300,000 mPa·s at 25°C was gently placed in this container. Next, a suspension prepared by dispersing 34 g of untreated TPO powder and 23 g of untreated 184 powder in 394 g of DOG, a low-viscosity liquid with a viscosity of 300 mPa·s at 25°C, was gently added. The untreated TPO powder contained clumps with a maximum total length of approximately 15 to 60 mm. The untreated 184 powder contained clumps with a maximum total length of approximately 5 to 30 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA, was used as an agitator with an agitating blade driven from the top of the vessel, and agitation was started at 6 rpm.
A 5 L round-bottom separable glass reaction vessel was heated in an oil bath to adjust the temperature to 50 to 55° C. Since the powder was difficult to dissolve, the stirring speed was increased to 130 rpm while monitoring the situation, and stirring was continued for a total of 7 hours.
Heating was stopped, and the mixture was cooled to 20-25°C, and stirring was then stopped. After the air bubbles that had become trapped in the mixture during stirring were released, visual inspection revealed that TPO and 184 had not completely dissolved, with clear residual dissolution. At this point, the viscosity of the mixture had dropped to approximately 2800 mPa s.
To this was gently added 6 g of DDT, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and 11 g of STMS, a low-viscosity liquid with a viscosity of 2 mPa s at 25°C, and the mixture was stirred at 60 rpm for 3 hours at 20-25°C. After stirring, the liquid was filtered through a flat filter medium, and when the surface of the filter medium was observed, it was found that TPO and 184 had not completely dissolved, with some residue remaining.
In conclusion, it was confirmed that it was difficult to completely dissolve untreated TPO and 184 in high viscosity liquids and low viscosity liquids, even when stirring was performed at high temperatures with increased stirring speed for a long period of time. The results are shown in Table 7.

Instead of Comparative Example 2, in Example 2, the TPO that had been previously classified using a sieve with 250 μm openings was replaced with unclassified TPO (TPO containing clumps with a maximum total length of approximately 15 to 60 mm). When mixing was carried out in the same manner as in Example 2, residual TPO was confirmed, resulting in the same results as in Comparative Example 2.

*The upper limit of temperature when mixing highly viscous liquid and powder is 60°C.

Example 9: Stirring and uniformly dissolving low-viscosity liquid and powder (ribbon blade A-2)
Stirring was carried out under the above-mentioned stirring and mixing conditions (2). Specifically, the conditions were as follows.
A ribbon impeller A-2 made of SUS304 and having an impeller diameter of 140 mm and an impeller total height of 220 mm was set in a 5 L round-bottom separable glass reaction vessel (inner diameter 150 mm, height 360 mm).
1170 g of DOG, a low-viscosity liquid with a viscosity of 300 mPa s at 25°C, was gently placed in the container. Subsequently, 100 g of TPO powder that had been previously classified using a sieve with 1 mm openings and 67 g of 184 powder that had been obtained in the same manner were gently added thereto, taking care not to create powder.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA, was used as an agitator with an agitating blade driven from the top of the vessel, and agitation was started at 6 rpm.
The temperature of a 5 L round-bottom separable glass reaction vessel was adjusted to 20 to 25° C. in order to prevent polymerization of DOG, and the stirring speed was increased to 60 rpm for a total of 4 hours of stirring.
When the stirring was stopped and the air bubbles trapped in the liquid during stirring were released, visual inspection revealed that TPO and 184 had almost completely dissolved, with almost no residue remaining.

Comparative Example 3: Stirring and uniformly dissolving low-viscosity liquid and powder (ribbon blade A-2)
Stirring was carried out under the above-mentioned stirring and mixing conditions (2). Specifically, the conditions were as follows.
A ribbon impeller A-2 made of SUS304 and having an impeller diameter of 140 mm and an impeller total height of 220 mm was set in a 5 L round-bottom separable glass reaction vessel (inner diameter 150 mm, height 360 mm).
1170 g of DOG, a low-viscosity liquid with a viscosity of 300 mPa·s at 25°C, was gently placed in the container. Next, 100 g of untreated TPO powder and 67 g of untreated 184 powder were gently added, taking care not to create dust. The untreated TPO powder contained clumps with a maximum total length of approximately 15 to 60 mm. The untreated 184 powder contained clumps with a maximum total length of approximately 5 to 30 mm.
An electronically controlled agitator, EUROSTAR 200, manufactured by IKA, was used as an agitator with an agitating blade driven from the top of the vessel, and agitation was started at 6 rpm.
The temperature of a 5 L round-bottom separable glass reaction vessel was adjusted to 20 to 25° C. in order to prevent polymerization of DOG, and the stirring speed was increased to 60 rpm for a total of 4 hours of stirring.
When the stirring was stopped and the air bubbles trapped in the liquid during stirring were released, visual inspection revealed that TPO and 184 had not completely dissolved, with clear residue remaining.

The present invention enables efficient homogenization of liquids and powders, and furthermore, enables homogenization of high-viscosity liquids, low-viscosity liquids, and powders using a single stirring blade and stirring vessel. Therefore, the present invention is useful for various homogenous mixing of liquids and powders, and for producing compositions obtained by dissolving powders in liquids.

1 Agitator shaft 2 Support rod 3 Ribbon blade 4 Bottom ribbon blade

Claims (8)

a stirring and dissolving step of stirring, in a stirring tank provided with a ribbon impeller, a highly viscous liquid having a viscosity of 10,000 mPa s or more as determined by the viscosity measurement method described below , and a powder from which coarse particles have been removed, by the ribbon impeller, and dissolving the powder in the highly viscous liquid;
a step of cooling the first composition obtained through the stirring and dissolving step;
a stirring step of adding a low-viscosity liquid having a viscosity of 1,000 mPa s or less as determined by the following viscosity measurement method to the stirring vessel containing the first composition, and stirring the liquid with the ribbon impeller;
a step of filtering the composition obtained through the stirring step using a filter medium;
A method for producing a composition comprising:
(Viscosity measurement method)
・Device: E-type viscometer
・Cone rotor type: 1°34 x R24
・Temperature: 25℃
・Rotation speed: 1 rpm
・Waiting time: 2 minutes The method for producing the composition described in claim 1 further comprises, after the filtering step, a step of visually observing the filter medium to confirm that the powder has dissolved. The method for producing a composition according to claim 1 or 2 , wherein the powder contains a photopolymerization initiator. The method for producing a composition according to any one of claims 1 to 3 , wherein the powder from which coarse particles have been removed is a powder from which coarse particles have been removed by classification. The method for producing a composition according to any one of claims 1 to 4, wherein the low-viscosity liquid contains a reactive monomer. a stirring and dissolving step of stirring, in a stirring tank provided with a ribbon impeller, a highly viscous liquid having a viscosity of 10,000 mPa s or more as determined by the viscosity measurement method described below , and a powder from which coarse particles have been removed, by the ribbon impeller, and dissolving the powder in the highly viscous liquid;
a step of cooling the first composition obtained through the stirring and dissolving step;
a stirring step of adding a low-viscosity liquid having a viscosity of 1,000 mPa s or less as determined by the following viscosity measurement method to the stirring vessel containing the first composition , and stirring the liquid with the ribbon impeller,
The method for mixing, wherein the powder contains a photopolymerization initiator.
(Viscosity measurement method)
・Device: E-type viscometer
・Cone rotor type: 1°34 x R24
・Temperature: 25℃
・Rotation speed: 1 rpm
・Waiting time: 2 minutes The mixing method according to claim 6 , wherein the powder from which the coarse particles have been removed is a powder from which the coarse particles have been removed by classification. 8. The method of claim 6, wherein the low viscosity liquid contains a reactive monomer.