WO2023167294A1

WO2023167294A1 - Method for producing hollow microparticles using supercritical liquid

Info

Publication number: WO2023167294A1
Application number: PCT/JP2023/007886
Authority: WO
Inventors: 康智清水; 一石福田; 剛美川崎
Original assignee: 株式会社トクヤマ
Priority date: 2022-03-04
Filing date: 2023-03-02
Publication date: 2023-09-07
Also published as: TW202348306A

Abstract

The present invention is a method for producing hollow microparticles having a resin film containing at least one resin selected from the group consisting of melamine resins, urea resins, amide resins, and urethane (urea) resins and a hollow portion surrounded by the resin film, wherein the method for producing hollow microparticles includes preparing an oil-in-water (O/W) emulsion, in which an oil phase containing an organic solvent is the dispersed phase and an aqueous phase is the continuous phase, to obtain microparticles having the organic solvent included in the interior, and removing the organic solvent from the interior of the microparticles using a supercritical liquid.　The present invention can provide a method for producing hollow microparticles easily and at a good yield.

Description

Manufacturing method of micro hollow particles using supercritical liquid

The present invention relates to a method for producing fine hollow particles using a supercritical liquid.

Micro hollow particles are used in many fields such as agricultural chemicals, pharmaceuticals, fragrances, liquid crystals, adhesives, electronic material parts, and building materials. Particularly in recent years, fine hollow particles have been studied for the purpose of forming pores in polyurethane (urea) CMP (Chemical Mechanical Polishing) polishing pads used for wafer polishing. Such fine hollow particles are required to have excellent solvent resistance, heat resistance, and preferable particle size control. In particular, in the field of CMP polishing pads, in order to achieve a high polishing rate and flatness at the atomic level, monodisperse fine hollow particles with a relatively large particle diameter of about 20 to 50 μm are desired. there is Therefore, Patent Document 1 discloses a method for producing fine hollow particles made of melamine resin, which is a thermosetting resin with excellent heat resistance and solvent resistance.

Patent Document 2 discloses a hollow microballoon for a CMP polishing pad, which is made of at least one resin selected from the group consisting of melamine resin, urea resin, and amide resin, and has an average particle size within a specific range.

In addition, as a method for drying fine particles, Patent Document 3 discloses a technique for drying fine particles using a radically polymerizable monomer with supercritical carbon dioxide.

JP-A-7-41594 WO2021/201088 Japanese Patent Publication No. 2008-523192

However, although the method of Patent Document 1 is excellent in heat resistance and solvent resistance, there is a problem from the viewpoint of controlling the particle size and its dispersibility.

In the method of Patent Document 2, particles with a large particle size can be obtained, but in the process of removing the organic solvent inside the fine particles, many fine particles are broken in the drying process, resulting in a low yield and an industrial problem. there were.

Patent Document 3 discloses a method using supercritical carbon dioxide as a drying method, but the monomers used are only radically polymerizable monomers, and there is no mention of the object using supercritical carbon dioxide other than the above. Moreover, no effect is disclosed.

Therefore, an object of the present invention is to provide a method for producing hollow microparticles easily and with high yield.

As a result of intensive studies to solve the above problems, the present inventors have found that after manufacturing fine particles in which an organic solvent is enclosed inside, the organic solvent inside the fine hollow particles is removed with a supercritical liquid. The present inventors have found that it is possible to produce hollow microparticles at a high yield and that the above problems can be solved, and have completed the present invention.

That is, the present invention relates to the following embodiments.
According to embodiments, a first method for producing hollow microparticles is provided. This manufacturing method is a method for manufacturing fine hollow particles. The fine hollow particles have a resin film and a hollow portion. The resin film contains at least one resin selected from the group consisting of melamine resins, urea resins, amide resins, and urethane (urea) resins. The hollow portion is surrounded by a resin film. This production method comprises preparing an oil-in-water (O/W) emulsion in which an oil phase containing an organic solvent is a dispersed phase and an aqueous phase is a continuous phase, to obtain microparticles in which the organic solvent is encapsulated. and removing the organic solvent from the interior of the microparticles using the supercritical fluid.
According to another embodiment, a method of making a curable composition is provided. This production method includes mixing hollow microparticles obtained by the production method according to the embodiment with a compound having an iso(thio)cyanate group.
According to another embodiment, a method of making a cured body is provided. This production method includes curing the curable composition obtained by the production method according to the embodiment.
According to another embodiment, a second method for producing hollow microparticles is provided. This manufacturing method is a method for manufacturing fine hollow particles having a resin film containing a melamine-based resin and a hollow portion surrounded by the resin film. This production method comprises preparing an oil phase containing an organic solvent, preparing an aqueous phase containing a surfactant containing a maleic anhydride copolymer, mixing and stirring the oil phase and the aqueous phase, and Preparing an oil-in-water (O/W) emulsion in which the phase is the continuous phase and the oil phase is the dispersed phase; O/W) causing a condensation reaction of the melamine-formaldehyde prepolymer compound on the interface of the emulsion to obtain a microparticle dispersion containing microparticles containing a resin film and an organic solvent enclosed inside the resin film; Separating the microparticles from the microparticle dispersion and removing the organic solvent from the interior of the microparticles using supercritical carbon dioxide. A method for producing fine hollow particles, wherein the amount of the aqueous phase is 100 parts by mass or more and 500 parts by mass or less when the oil phase is 100 parts by mass.
According to another embodiment, hollow microparticles are provided. The fine hollow particles have a resin film and a hollow portion. The resin film contains at least one resin selected from the group consisting of melamine resins, urea resins, amide resins, and urethane (urea) resins. The hollow portion is surrounded by a resin film. These hollow microparticles are obtained by preparing an oil-in-water (O/W) emulsion in which the oil phase containing the organic solvent is the dispersed phase and the water phase is the continuous phase, and the microparticles encapsulating the organic solvent inside are obtained. After that, it is obtained by removing the organic solvent from the inside of the microparticles using a supercritical liquid.
According to another embodiment, a resin composition is provided. This resin composition contains the hollow microparticles according to the embodiment and a polyurethane resin.
According to another embodiment, a CMP polishing pad is provided. This CMP polishing pad contains the resin composition according to the embodiment.

According to the present invention, there is provided a method for obtaining hollow microparticles simply and in good yield by removing the organic solvent inside the microhollow particles with a supercritical fluid.

In addition, the fine hollow particles of the present invention can be applied to various uses, for example, in many fields such as agricultural chemicals, medicines, cosmetic materials, liquid crystals, adhesives, electronic material parts, and building materials. In particular, the fine hollow particles of the present invention can be applied to fields such as shoe soles, shoe insoles, heat insulating materials, sound insulating materials, and CMP polishing pads.

According to embodiments, a first method for producing hollow microparticles is provided. This manufacturing method is a method for manufacturing fine hollow particles. The fine hollow particles have a resin film and a hollow portion. The resin film contains at least one resin selected from the group consisting of melamine resins, urea resins, amide resins, and urethane (urea) resins. The hollow portion is surrounded by a resin film. This production method comprises preparing an oil-in-water (O/W) emulsion in which an oil phase containing an organic solvent is a dispersed phase and an aqueous phase is a continuous phase, to obtain microparticles in which the organic solvent is encapsulated. and removing the organic solvent from the interior of the microparticles using the supercritical fluid.
According to this production method, hollow microparticles having a resin film having relatively high hardness, such as melamine resin, urea resin, amide resin, and urethane (urea) resin, can be easily produced at a high yield. That is, in the production of hollow microparticles, a drying step is required to remove the organic solvent from the inside of the resin film. If the resin film has a dense structure and high hardness, it is difficult to remove the organic solvent inside it, and in the drying process using an oven or the like, cracks may occur in the resin film, the particles themselves may be broken, and the film may become powdery. only may remain. In fact, when performing thermal decomposition measurements on fine particles containing an organic solvent, the mass reduction may accelerate above the boiling point of the internal organic solvent. It is presumed that this is because the boiling point has risen. Furthermore, it is believed that the organic solvent vaporizes when the boiling point is exceeded, and finally the fine hollow particles are destroyed when the mechanical strength exceeds the limit. In the manufacturing method according to the embodiment, a supercritical liquid is used for this drying step. A supercritical fluid has a high permeability to a resin film and a high diffusion rate in the resin film. As a result, the organic solvent inside the resin film is dissolved or dispersed in the permeating supercritical carbon dioxide, thereby improving the permeability to the resin film and being discharged out of the particles. It can be replaced by a supercritical fluid. After this replacement process, the supercritical liquid replaced inside the resin film changes to gas in the process of lowering the pressure and temperature to get out of the supercritical state. Therefore, it is considered that the use of a supercritical liquid makes it difficult for the resin film to be destroyed during the drying process, as compared with high-temperature drying using an oven or the like, so that hollow microparticles can be obtained at a high yield.

The fine hollow particles of the present invention are composed of a resin film made of at least one resin selected from the group consisting of melamine resin, urea resin, amide resin, and urethane (urea) resin. The average particle size of the fine hollow particles is, for example, 1 to 100 μm. Micro hollow particles are prepared by preparing an oil-in-water (O/W) emulsion (hereinafter also referred to as "O/W emulsion") in which an oil phase containing an organic solvent is a dispersed phase and a water phase is a continuous phase, After obtaining the microparticles in which the organic solvent is encapsulated, the organic solvent is removed from the inside of the microparticles using a supercritical liquid.

In the present invention, the melamine resin is a resin obtained by polycondensation of a polyfunctional amine whose main chain contains melamine and formaldehyde, and the urea resin is a resin whose main chain is urea (including polyfunctional amine) and formaldehyde. The amide resin is a resin having an amide bond in the main chain, and the urethane (urea) resin is a resin obtained by polycondensation with an isocyanate group and a hydroxyl group and/or an amino group. , a resin having a urethane bond, a urea bond, or both a urethane bond and a urea bond in the main chain.

As the supercritical liquid that can be used in the present invention, for example, at least one selected from the group consisting of carbon dioxide, ethane, ethylene, propane, oxygen and nitrogen is used. Carbon dioxide is preferably used as the supercritical liquid. Here, a supercritical liquid is a substance that has a density close to that of a liquid and a viscosity as low as that of a gas when in a supercritical state that exceeds the critical temperature and pressure, and is in an intermediate state between a liquid and a gas. means The supercritical temperature and supercritical pressure at which the above-mentioned carbon dioxide, nitrogen, ethane, ethylene, propane, and oxygen are in the supercritical state are carbon dioxide (31.1 degrees, 7.4 MPa), nitrogen (-147 degrees, 3.4 MPa), ethane (32 degrees, 4.9 MPa), ethylene (9.2 degrees, 5.0 MPa), propane (97 degrees, 4.2 MPa), oxygen (-118 degrees, 5.1 MPa ).

In general, large emulsions exceeding several tens of μm during emulsion formation have low stability. The lack of liquid makes it easy to wither, resulting in a low yield.

In the present invention, by using a supercritical liquid that has excellent solubility close to liquid and excellent diffusivity close to gas, it is highly soluble in resin and has a high diffusion rate in resin. It can be removed by replacing the organic solvent inside the microparticles. In addition, in a state in which the microparticles contain the supercritical liquid, the gas can be retained inside the microhollow particles by returning the supercritical state to the gas. It is speculated that it is possible to obtain fine hollow particles at a high rate.

As described above, the hollow microparticles of the present invention are resin films made of at least one resin selected from the group consisting of melamine resins, urea resins, amide resins, and urethane (urea) resins. Configured. Among them, the preferred resin in the present invention is melamine resin.

The preferred average particle size of the fine hollow particles of the present invention is 1 to 100 μm. Within this range, for example, when blended in a CMP polishing pad, excellent polishing properties can be exhibited. More preferably, the average particle size of the fine hollow particles is 5-80 μm, most preferably 10-50 μm.

An image analysis method can be used to measure the average particle size of hollow microparticles. Particle size can be easily measured using image analysis methods. The average particle size is the average particle size of primary particles. The average particle size can be measured by image analysis using, for example, a scanning electron microscope (SEM).

Although the bulk density of the hollow microparticles of the present invention is not particularly limited, it is preferably 0.01 to 0.5 g/cm ³ . Within this range, it can be suitably used for heat insulating materials and CMP polishing pads, for example.

Although the ash content of the hollow microparticles of the present invention is not particularly limited, it is preferably 0.5 parts by mass or less per 100 parts by mass of the hollow microparticles in the method described in the examples below. , more preferably 0.3 parts by mass or less, more preferably 0.1 parts by mass or less, and most preferably not measured. Within this range, it is possible to reduce wafer defects when used as a CMP polishing pad.

In the method for producing hollow microparticles of the present invention, in the step of obtaining microparticles, an O/W emulsion in which an oil phase containing an organic solvent is a dispersed phase and an aqueous phase is a continuous phase is prepared, and the organic solvent is contained inside the microparticles. It is a manufacturing method of obtaining encapsulated microparticles and removing the organic solvent from the inside of the microparticles using a supercritical liquid.

The method for forming a resin film in the O/W emulsion of the fine hollow particles can be subdivided into the first step: (a) an oil phase containing an organic solvent to which components constituting the resin film are added as necessary (hereinafter referred to as , step of preparing "component (a)"), step 2: step of preparing an aqueous phase (b) containing a surfactant (hereinafter also referred to as "component (b)"), step 3: A step of mixing and stirring the component (a) and the component (b) to prepare an O/W emulsion in which the aqueous phase is a continuous phase and the oil phase is a dispersed phase; A component constituting a resin film is added to the W emulsion, and a condensation reaction is allowed to proceed on the interface of the O/W emulsion to form a resin film to form microparticles, in which an organic solvent is encapsulated. A step of obtaining a fine particle dispersion in which is dispersed, a fifth step: separating fine particles having an organic solvent enclosed therein from the fine particle dispersion, a sixth step: from the inside of the fine particles, a supercritical liquid and removing the organic solvent solution to form fine hollow particles.

When the fine hollow particles are composed of a resin film made of melamine resin, they are manufactured by the following steps.

First step:
The first step is to prepare (a) an oil phase containing an organic solvent, which will be the dispersed phase in the O/W emulsion. In this step, substances other than the organic solvent can be contained, but usually the oil phase is composed only of the organic solvent.

Second step:
The second step is a step of preparing (b) an aqueous phase containing a surfactant, which will be the continuous phase in the O/W emulsion, and a step of adjusting the pH as necessary.

This step includes dissolving a surfactant, which will be described later, in water and adjusting the pH as necessary. Adjustment of pH, etc. may be prepared using a known method.

The amount of surfactant used in the present invention is preferably 0.1 to 10%, more preferably 1 to 10%, relative to the aqueous phase. Within this range, aggregation of droplets of the dispersed phase in the O/W emulsion can be avoided, and fine hollow particles can be easily obtained with high yield.

Third step:
In the third step, the (a) component obtained in the first step and the (b) component obtained in the second step are mixed and stirred, and the (a) component is the dispersed phase and the (b) component is continuous. This is a step of preparing an O/W emulsion as a phase.

In the present invention, the method of mixing and stirring the components (a) and (b) to form an O/W emulsion takes into account the particle size of the hollow microparticles to be produced, and mixes and stirs them by a suitable known method. can be adjusted by Furthermore, temperature and pH can be adjusted in the process of preparing the O/W emulsion.

Among them, after mixing the component (a) and the component (b), O/ A W emulsion method is preferably employed, and among these, a high-speed shearing method is preferred. When using a high-speed shearing disperser, the rotation speed is preferably 500 to 20,000 rpm, more preferably 1,000 to 10,000 rpm. The dispersing time is preferably 0.1 to 30 minutes, preferably 1 to 10 minutes. The dispersion temperature is preferably 20-80°C.

Further, in the present invention, the weight ratio of component (a) to component (b) is preferably 100 to 500 parts by mass of component (b), more preferably 100 parts by mass of component (a). is 150 to 300 parts by mass.

Fourth step:
In the fourth step, a melamine-formaldehyde prepolymer compound is added to the O/W emulsion, and a condensation reaction of the melamine-formaldehyde prepolymer compound occurs on the interface of the O/W emulsion to form a resin film. It is a step of forming fine particles in which an organic solvent is encapsulated in the liquid, and obtaining a fine particle dispersion liquid in which the formed fine particles are dispersed.

The amount of the melamine formaldehyde prepolymer compound to be used is not particularly limited, but it should be 20 to 100 parts by mass per 100 parts by mass of component (a) used in the first step in order to form fine particles well. is preferred.

As the melamine formaldehyde prepolymer compound, a commercially available melamine formaldehyde prepolymer compound described below may be added as it is, or may be used by dissolving in water or an alkaline aqueous solution, or melamine and formaldehyde may be used according to a conventional method. It is also possible to use a melamine-formaldehyde prepolymer compound produced in an alkaline aqueous solution by the addition reaction of formaldehyde to melamine by heating in an alkaline range.

When the melamine formaldehyde prepolymer compound is 100 parts by mass, water or an alkaline aqueous solution is preferably used in the range of 0 to 500 parts by mass, more preferably in the range of 20 to 300 parts by mass.

The pH of the aqueous phase, which is the continuous phase, should be adjusted after adding the melamine-formaldehyde prepolymer compound. The pH of the aqueous phase, which is the continuous phase, is preferably less than 7, more preferably 3.5 to 6.5, most preferably 3.5 to 5.5. is preferred. A preferable reaction temperature is preferably in the range of 40 to 90°C. The reaction time is preferably in the range of 1 to 48 hours.

Fifth step:
The fifth step is a step of separating microparticles having an organic solvent enclosed therein from the microparticle dispersion. The separation method for separating the microparticles having an organic solvent enclosed therein from the microparticle dispersion is not particularly limited, and may be selected from general separation techniques. Specifically, filtration, centrifugation, and the like are used. .
The fine particles after separation are preferably pretreated before being subjected to supercritical fluid treatment. The pretreatment includes hydrophilic organic solvent treatment. That is, it is preferable to bring the separated microparticles into contact with a hydrophilic organic solvent to remove water from the surfaces of the microparticles. As a result, the microparticles after separation and the supercritical liquid tend to become more compatible.
Hydrophilic organic solvents include at least one compound selected from the group consisting of ethanol, tert-butyl alcohol, acetone, acetonitrile, DMSO, DMF, and ethylene glycol. At least one compound selected from the group consisting of ethanol and tert-butyl alcohol is preferably used as the hydrophilic organic solvent.
The mass M1 of the fine particles, the mass M2 of the hydrophilic organic solvent, and the ratio M1/M2 are, for example, 0.1 or more and 5 or less. The ratio M1/M2 is preferably 0.2 or more and 2 or less.
The contact time between the microparticles and the hydrophilic organic solvent is set to, for example, 1 minute or more and 20 minutes or less after ensuring sufficient contact. This contact time is preferably 3 minutes or more and 10 minutes or less.
Specifically, this pretreatment is performed by immersing the microparticles in a hydrophilic organic solvent for a predetermined period of time. After immersion, the microparticles are removed from the hydrophilic organic solvent by, for example, filtration. The removed microparticles may be subjected to a drying treatment such as freeze-drying.

Sixth step:
The sixth step is a step of using a supercritical liquid to remove the internal oil phase from the microparticles obtained in the fifth step and having the organic solvent encapsulated therein, to obtain hollow microparticles. A known technique can be used for removing the internal organic solvent with a supercritical fluid. For example, in the presence of the fine particles, the supercritical temperature and supercritical pressure of the supercritical liquid are set to the conditions above, and the internal organic It is preferable to replace the solvent with a supercritical liquid. After the substitution, the pressure is reduced and the temperature is returned to room temperature to obtain hollow microparticles. If the microparticles contain a large amount of water, the water can be efficiently removed by flowing a hydrophilic solvent together with the supercritical liquid, making a slurry with the hydrophilic solvent, or pretreating by decantation or filtration. It becomes possible to remove the oil phase.

The preferred supercritical liquid in the present invention is supercritical carbon dioxide, and preferred conditions for using supercritical carbon dioxide are 40° C. to 90° C. and 16 MPa to 40 MPa.
In the drying process using the supercritical liquid, the pressure of the supercritical liquid is preferably 10 MPa or more and 40 MPa or less. When the pressure is within this range, the supercritical carbon dioxide penetrates more into the hollow fine particles, and the organic solvent contained in the particles is efficiently removed, which tends to increase the yield of fine hollow particles. This pressure is more preferably 12 MPa or more and 30 MPa or less, and further preferably 14 MPa or more and 20 MPa or less.
The temperature inside the apparatus using the supercritical liquid is preferably 31.1° C. or higher and 60° C. or lower. When the temperature is within this range, the yield of fine hollow particles tends to increase. This temperature is more preferably 35° C. or higher and 50° C. or lower. The flow rate of the supercritical liquid is preferably 1 mL/min or more and 200 mL/min or less. When the flow rate is within this range, the yield of fine hollow particles tends to increase. This flow rate is more preferably 20 mL/min or more and 100 mL/min or less, and still more preferably 30 mL/min or more and 50 mL/min or less.
The contact time between the supercritical liquid and the microparticles is preferably 10 minutes or more and 720 minutes or less. When the contact time is within this range, the yield of fine hollow particles tends to increase. This contact time is more preferably 20 minutes or more and 120 minutes or less, and even more preferably 30 minutes or more and 55 minutes or less.

Each component is explained below.

In the present invention, the organic solvent used for component (a) is not particularly limited, but an organic solvent having a boiling point of 90°C to 200°C is preferable. Within this range, it is preferable that the emulsion formation can be maintained even at the polymerization temperature, and that the organic solvent can be easily removed from the obtained microparticles.

More preferably, it has a boiling point of 100°C to 180°C. Examples of these include the following.

Examples of hydrocarbon solvents include aliphatic hydrocarbons having 7 to 11 carbon atoms, alicyclic hydrocarbons such as cycloheptane and cyclooctane, butyl acetate, dibutyl ether, 1,2-dichloroethane, toluene, xylene, benzaldehyde, Chlorobenzene, dichlorobenzene and the like are used.

These organic solvents may be used alone or as a mixed solvent of two or more.

Among the organic solvents used in the present invention, aliphatic hydrocarbons having 8 to 11 carbon atoms, cycloheptane, cyclooctane, toluene, xylene, and chlorobenzene are more preferred, and toluene, xylene, and chlorobenzene are most preferred.

In the present invention, the surfactant used for component (b) is not particularly limited, and two or more types may be mixed. As specific examples of the surfactant of the present invention, compounds described in International Publication No. WO2021/201088 can be used. Among them, in the case of the component (b) in which the hollow microparticles are made of a melamine resin, those having a carboxyl group as at least one hydrophilic group are preferable, and the carboxyl group may be generated by hydrolysis of a dicarboxylic acid anhydride. good. Among them, maleic anhydride copolymers such as styrene-maleic anhydride copolymer, ethylene-maleic anhydride copolymer and isobutylene-maleic anhydride copolymer can be preferably used, and more preferably styrene-maleic anhydride copolymer. Acid copolymers can be preferably used. The maleic anhydride copolymer described above preferably has a weight average molecular weight of about 30,000 to 500,000, most preferably about 100,000 to 500,000. Within this range, a stable emulsion and resin film can be formed. In addition, a weight average molecular weight is a standard polystyrene conversion value measured by a gel permeation chromatography (GPC).

The melamine-formaldehyde prepolymer compound that can be used in the present invention can be produced from melamine and formaldehyde by a conventional method. For example, it can be produced by adding formaldehyde to melamine by heating in an alkaline region in an alkaline aqueous solution containing melamine and formaldehyde. In addition, commercially available melamine formaldehyde prepolymer compounds can be used as appropriate. For example, Beckamin APM, Beckamin M-3, Beckamin M-3 (60), Beckamin MA-S, Beckamin J-101, Beckamin J-101LF (manufactured by DIC Corporation), Nikaresin S-176, Nikaresin S-260 ( Nippon Carbide Co., Ltd.), Milben Resin SM-800 (Showa Polymer Co., Ltd.), and the like.

The mechanism of the formation of the hollow microparticles is as follows: droplets of (a) an oil phase containing an organic solvent are dispersed in an aqueous phase, and the hydrophilic groups (e.g., carboxyl groups) of the surfactant coordinated on the droplet interface Methylolated melamine contained in the melamine-formaldehyde prepolymer compound forms an acid amide bond, whereby the droplets are surrounded by methylolated melamine, and in this surrounded state, adjacent methylolated melamine undergoes dehydration condensation between methylol groups. It is believed that they react to form a resin film made of melamine-based resin. The ratio of methylolation of melamine (molar ratio of formaldehyde to melamine) is related to the density of the resin film, and the higher the ratio of methylolation, the higher the crosslink density and the more dense the resin film. Therefore, it is preferable to use a methylolated melamine within the range described below as the methylolated melamine.

The molar ratio of melamine and formaldehyde can be adjusted from monomethylolated melamine (melamine/formaldehyde molar ratio: 1/1) to hexamethylolated melamine (molar ratio of melamine/formaldehyde: 1/6). Trimethylolated melamine (1/3 of the same) to pentamethylolated melamine (1/5 of the same) are suitable from both aspects of enveloping properties against droplets and condensation reactivity (crosslinking), especially tetramethylolated melamine (1/5 1/4) is preferred.

When the hollow microparticles of the present invention are composed of a resin film made of urea resin, amide resin, and urethane (urea) resin, an O/W emulsion is prepared to obtain microparticles in which an organic solvent is encapsulated inside the microparticles. It may be produced using a known method for obtaining particles.

In the case of urea resin, it can be produced by the same production method as for the melamine resin described above, and is produced in the same manner by using a urea formaldehyde prepolymer instead of the melamine formaldehyde prepolymer compound in the fourth step of the melamine resin described above. can do

The urea-formaldehyde prepolymer compound is a urea-formaldehyde initial condensate of urea and formaldehyde, and can be produced by a conventional method. Urea-formaldehyde precondensates of urea and formaldehyde include, for example, methylol urea. As the urea-formaldehyde prepolymer compound, commercially available ones can be used as appropriate. Examples thereof include 8HSP (manufactured by Showa High Polymer Co., Ltd.).

When the fine hollow particles are composed of a resin film made of an amide resin, they are manufactured by the following steps.

First step:
In the first step, the dispersed phase in the O/W emulsion is (a2) an oil phase containing a polyfunctional carboxylic acid compound having at least two carboxyl groups and an organic solvent (hereinafter also referred to as "(a2) component"). is a step of preparing

Component (a2) in this step is a step of dissolving a polyfunctional carboxylic acid compound having at least two carboxyl groups in an organic solvent exemplified in component (a) above to form an oil phase, It can be dissolved by a known method to form a homogeneous solution. The preferred amount of the polyfunctional carboxylic acid compound having at least two carboxyl groups is 0.1 to 50 parts by weight, preferably 0.5 to 20 parts by weight, more preferably 1 to 50 parts by weight per 100 parts by weight of the organic solvent. 10 parts by mass. Furthermore, a polyfunctional amine having at least two amino groups used in the fourth step described later, relative to the number of moles (n1) of carboxylic acid groups contained in the polyfunctional carboxylic acid compound having at least two carboxyl groups, When the total number of moles of amino group-containing compounds in the compounds is (n2), the range is preferably 0.5≦(n1)/(n2)≦2.

In addition, a catalyst, which will be described later, may be added to the component (a2) for the purpose of promoting the interfacial polymerization reaction.

Second step:
The second step is a step of preparing an aqueous phase (b2) containing a surfactant (hereinafter also referred to as "component (b2)"), which will be the continuous phase in the O/W emulsion.

This step is a step of dissolving a surfactant, which will be described later, in water to form an aqueous phase.

The amount of surfactant used in the present invention is preferably 0.01 to 20%, more preferably 0.1 to 10%, relative to the aqueous phase. Within this range, aggregation of droplets of the dispersed phase in the O/W emulsion is avoided, and fine particles having a uniform average particle size are easily obtained.

In addition, a catalyst, which will be described later, may be added to the component (b2) for the purpose of promoting the interfacial polymerization reaction.

Third step:
In the third step, the (a2) component obtained in the first step and the (b2) component obtained in the second step are mixed and stirred, and the (b2) component is a continuous phase and the (a2) component is dispersed. This is a step of preparing an O/W emulsion as a phase.

In the present invention, the method of mixing and stirring the components (a2) and (b2) to form an O/W emulsion takes into account the particle size of the microparticles to be produced, and mixes and stirs them by a suitable known method. It can be prepared by

Among them, after mixing the component (a2) and the component (b2), O/ A W emulsion method is preferably employed, and among these, a high-speed shearing method is preferred. When using a high-speed shearing disperser, the rotation speed is preferably 500 to 20,000 rpm, more preferably 1,000 to 10,000 rpm. The dispersing time is preferably 0.1 to 60 minutes, preferably 0.5 to 30 minutes. The dispersion temperature is preferably 10-40°C.

In the present invention, the weight ratio of component (a2) to component (b2) is preferably 100 to 1000 parts by mass of component (b2), more preferably 100 parts by mass of component (a2). is preferably 150 to 500 parts by mass. Within this range, a good emulsion can be obtained.

Fourth step:
In the fourth step, a polyfunctional amine compound having at least two amino groups is added to the O/W emulsion, interfacially polymerized on the interface of the O/W emulsion to form a resin film, and fine particles and This is a step of obtaining a fine particle dispersion in which the fine particles are dispersed. The amount of the polyfunctional amine compound having at least two amino groups is as described above.

Also, when adding a polyfunctional amine compound having at least two amino groups to an O/W emulsion, it may be added as it is, or it may be dissolved in water in advance before use.

When dissolved in water in advance, it is preferable to use water in the range of 50 to 10,000 parts by mass when the total amount of the polyfunctional amine compound having at least two amino groups is 100 parts by mass.

The polymerization temperature is not particularly limited as long as it does not break the O/W emulsion, and the reaction is preferably carried out in the range of 5 to 70°C. The polymerization time is not particularly limited as long as fine particles can be formed, and is usually selected from the range of 0.5 to 24 hours.

Fifth and Sixth Steps The fifth and sixth steps are the same steps as in the case where the fine hollow particles are composed of a resin film made of a melamine-based resin.

Specific examples of the polyfunctional carboxylic acid compound having at least two carboxyl groups in the component (a2) and the polyfunctional amine having at least two amino groups in the additive phase include International Publication No. WO2021/201088. can be used. Among them, the polyfunctional carboxylic acid compound having at least two carboxyl groups is preferably an aromatic dicarboxylic acid dichloride, most preferably isophthalic acid dichloride and terephthalic acid dichloride.
Among surfactants that can be used as the component (b2), it is preferable to use a sodium acrylate-acrylate copolymer.

When the fine hollow particles are composed of a resin film made of urethane resin, they are manufactured by the following steps.

First step:
In the first step, the dispersed phase in the O/W emulsion is (a3) an oil phase containing a polyfunctional isocyanate compound having at least two isocyanate groups and an organic solvent (hereinafter also referred to as "(a3) component"). is a step of preparing

The (a3) component in this step is a step of dissolving an isocyanate compound having at least two isocyanate groups in an organic solvent exemplified in the above-described component (a) to form an oil phase, which is a known method. It is good to make a uniform solution by dissolving with . The preferred amount of the polyfunctional isocyanate compound having at least two isocyanate groups is 0.1 to 50 parts by weight, preferably 0.5 to 20 parts by weight, more preferably 1 to 10 parts by weight, per 100 parts by weight of the organic solvent. part by mass. Furthermore, with respect to the number of moles (n1) of isocyanate groups contained in the polyfunctional isocyanate compound having at least two isocyanate groups, the polyol, polyamine, and hydroxyl group and amino group used in the later-described fourth step have both When the total number of moles of active hydrogen groups contained in the active hydrogen-containing compound is (n2), the range is preferably 0.5≦(n1)/(n2)≦2.

In addition, a catalyst, which will be described later, may be added to the component (a3) for the purpose of promoting the interfacial polymerization reaction.

Second step:
The second step is a step of preparing an aqueous phase (b3) containing a surfactant and water (hereinafter also referred to as "component (b3)"), which will be the continuous phase in the O/W emulsion. As a preparation method, it can be prepared in the same manner as the component (b2) described above.

Third Step The third step is the same step as in the case where the fine hollow particles are composed of a resin film made of an amide resin.

Fourth step:
In the fourth step, at least one selected from polyols, polyamines, and active hydrogen-containing compounds having both a hydroxyl group and an amino group is added to the O/W emulsion, and interfacial polymerization is performed on the interface of the O/W emulsion. This is a step of obtaining a fine particle dispersion liquid in which the fine particles are dispersed by forming a resin film and forming fine particles. The amount of at least one selected from polyols, polyamines, and active hydrogen-containing compounds having both a hydroxyl group and an amino group is 0.001 to 100 parts by mass with respect to 100 parts by mass of the organic solvent used in the first step. parts, preferably 0.01 to 80 parts by mass, more preferably 0.01 to 50 parts by mass.

Also, polyols, polyamines, and active hydrogen-containing compounds having both hydroxyl and amino groups are at least partially soluble in water and have a higher affinity for hydrophilic phases than for hydrophobic phases. compounds, generally having a solubility of at least 1 g/l in a hydrophilic solvent such as water at room temperature (25° C.), preferably hydrophilic Water-soluble compounds having a solubility of 20 g/l or more in the solvent are mentioned.

When polyols, polyamines, and active hydrogen-containing compounds having both hydroxyl groups and amino groups are added to the O/W emulsion, they may be added as they are, or they may be dissolved in water in advance before use.

When dissolved in water in advance, when the total amount of polyol, polyamine, and active hydrogen-containing compound having both a hydroxyl group and an amino group is 100 parts by mass, it is preferable to use water in the range of 50 to 10,000 parts by mass. preferred.

Here, specific examples of the polyfunctional isocyanate compound having at least two isocyanate groups in the component (a3), polyols, polyamines, and active hydrogen-containing compounds having both hydroxyl groups and amino groups include International Publication No. WO2021/ 065625 can be used.

Among them, polyfunctional isocyanate compounds include isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and (bicyclo[2.2.1]) from the viewpoint of controlling the strength and reactivity of the formed microparticles. alicyclic isocyanate selected from heptane-2,5(2,6)-diyl)bismethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xyl A polyfunctional compound having a biret structure, a uretdione structure, or an isocyanurate structure mainly made from aromatic isocyanates selected from diisocyanates (o-, m-, p-), diisocyanates such as hexamethylene diisocyanate and tolylene diisocyanate. Polyfunctional isocyanates are suitable as isocyanates and adducts with trifunctional or higher polyols.

Examples of polyols, polyamines, and active hydrogen-containing compounds having both a hydroxyl group and an amino group include ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 2, Bifunctional polyols such as 3-butanediol and 1,4-butanediol; Trifunctional polyols such as glycerin, trimethylolethane and trimethylolpropane; Tetrafunctional polyols such as pentaerythritol, erythritol, diglycerol, diglycerin and ditrimethylolpropane Polyol; pentafunctional polyol such as arabitol; hexafunctional polyol such as dulcitol, sorbitol, mannitol, dipentaerythritol or triglycerol; cyclic dextrin; ethylenediamine, propylenediamine, 1,4-diaminobutane, hexamethylenediamine, dipropylenetriamine, Water-soluble polyamines such as tris(2-aminoethyl)amine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine are preferred.

Also, as the surfactant contained in the component (b3), it is preferable to use polyvinyl alcohol or anion-modified polyvinyl alcohol.

In the present invention, any appropriate amidation catalyst can be used without any limitation when the fine hollow particles are composed of a resin film made of an amide resin. Specific examples include boron and sodium dihydrogen phosphate.

In addition, any suitable urethanization catalyst can be used without any limitation when the fine hollow particles are composed of a resin film made of urethane (urea) resin or when synthesizing a urethane prepolymer. Specific examples include triethylenediamine, hexamethylenetetramine, N,N-dimethyloctylamine, N,N,N',N'-tetramethyl-1,6-diaminohexane, 4,4'-trimethylenebis ( 1-methylpiperidine), 1,8-diazabicyclo-(5,4,0)-7-undecene, dimethyltin dichloride, dimethyltin bis(isooctylthioglycolate), dibutyltin dichloride, dibutyltin dilaurate, dibutyltin maleate, Dibutyltin Maleate Polymer, Dibutyltin Diricinolate, Dibutyltin Bis (Dodecyl Mercaptide), Dibutyltin Bis (isooctylthioglycolate), Dioctyltin Dichloride, Dioctyltin Maleate, Dioctyltin Maleate Polymer, Dioctyltin Bis(butyl maleate) ), dioctyltin dilaurate, dioctyltin diricinolate, dioctyltin dioleate, dioctyltin di(6-hydroxy)caproate, dioctyltin bis(isooctylthioglycolate), didodecyltin diricinolate, various metal salts, Examples thereof include copper oleate, copper acetylacetonate, iron acetylacetonate, iron naphthenate, iron lactate, iron citrate, iron gluconate, potassium octanoate, and 2-ethylhexyl titanate.

In addition, in the present invention, additives may be added to the aqueous phase for the purpose of further stabilizing the emulsion within a range that does not impair the effects of the present invention. Examples of such additives include water-soluble salts such as sodium carbonate, calcium carbonate, potassium carbonate, sodium phosphate, potassium phosphate, calcium phosphate, sodium chloride and potassium chloride. These additives can be used alone or in combination of two or more.

The fine hollow particles of the present invention can be applied to various uses, for example, in many fields such as agricultural chemicals, pharmaceuticals, cosmetic materials, liquid crystals, adhesives, electronic material parts, and building materials. In particular, the fine hollow particles of the present invention can be suitably used for applications such as shoe soles, shoe insoles, heat insulating materials, sound insulating materials, and CMP polishing pads.

As the method used for the above-mentioned CMP polishing pad application, known methods can be employed without limitation. By cutting and polishing the surface, a CMP polishing pad having pores on the polishing surface of the resin can be obtained.

The resin is not particularly limited, but in the present invention, the polyurethane resin described later is particularly suitable. In particular, since the hollow microparticles of the present invention have good compatibility with polyurethane resins, when used in a CMP polishing pad, the hollow microparticles are less likely to fall off, making it possible to improve scratch resistance. .

Also, the density of the CMP polishing pad of the present invention is preferably 0.40 to 1.10 g/cm ³ , more preferably 0.50 to 1.05 g/cm ³ . Further, a hardened foam obtained by combining the fine hollow particles of the present invention with a known foaming method can also be used as a CMP polishing pad. As a known foaming method, for example, a foaming agent foaming method in which water is added, in the case of a polyurethane resin, carbon dioxide and an amino group are generated after the reaction between water and an iso(thio)cyanate group. The carbon dioxide serves as a foaming gas, and the amino group further reacts with an iso(thio)cyanate group to form a urea bond and/or a thiourea bond.

The CMP polishing pad of the present invention can have any suitable hardness. The hardness in the present invention can be measured according to the Shore method, for example, according to JIS standard (hardness test) K6253. In the present invention, the Shore hardness of the CMP polishing pad is preferably 30A to 80D, more preferably 40A to 70D (where "A" is Shore "A" scale, and "D" is Shore " D" indicates hardness on the scale). That is, for example, 30A to 80D means that the Shore A hardness is 30 or more and the Shore D hardness is 70 or less.

The hardness can be arbitrarily set by changing the blending composition and blending amount as necessary.

Furthermore, the CMP polishing pad of the present invention preferably has a compressibility within the following range in order to develop the flatness of the object to be polished. Compression rate can be measured by a method conforming to JIS L 1096. The compressibility is preferably 0.5% to 50%. Within the above range, it is possible to exhibit excellent flatness of the object to be polished.

The abrasion resistance of the CMP polishing pad of the present invention is preferably 60 mg or less, more preferably 50 mg or less in the Taber abrasion test. By reducing the amount of Taber wear, it is possible to exhibit excellent wear resistance when used as a CMP polishing pad.

The aspect of the CMP polishing pad of the present invention is not particularly limited, and for example, a groove structure may be formed on its surface. The groove structure of the CMP polishing pad preferably has a shape that retains and renews the slurry. , polygonal prisms, cylinders, spiral grooves, eccentric circular grooves, radial grooves, and combinations of these grooves.

Also, the method for producing the groove structure of the CMP polishing pad is not particularly limited. For example, a method of pouring the above-described compound into a mold having a predetermined groove structure and curing it, or a method of creating a groove structure using the obtained resin, for example, a tool of a predetermined size A method of mechanical cutting using a jig such as, a method of manufacturing by pressing a resin with a press plate having a predetermined surface shape, a method of manufacturing using photolithography, a method of manufacturing using a printing method, carbonic acid Examples include a production method using laser light such as a gas laser.

Also, the CMP polishing pad of the present invention may be composed of a plurality of layers. In this case, the cured product of the present invention may be used in at least one of the layers. For example, when a CMP polishing pad is composed of two layers, a polishing layer (also referred to as a first layer) having a polishing surface that contacts an object to be polished during polishing and a surface of the first layer that faces the polishing surface Thus, a two-layer structure of the first layer and the base layer (also referred to as the second layer) in contact with the first layer is obtained. In this case, the characteristics of the CMP polishing pad can be adjusted by making the second layer and the first layer different in hardness and elastic modulus. In this case, the underlayer preferably has a lower hardness than the polishing layer. In the present invention, it is preferable to use the cured product of the present invention as a polishing layer, and the cured product of the present invention may also be used as a base layer.

The polyurethane resin used for the CMP polishing pad described above will be described in detail below.

The polyurethane resin in the CMP polishing pad may be prepared by a known method without particular limitation as long as the medium-sized fine particles are dispersed in the polyurethane resin. and (d) a compound having two or more isocyanate groups and curable active hydrogen groups, such as hydroxyl groups, thiol groups, and amino groups (hereinafter also referred to as "(d) component" ), and a method of uniformly mixing and dispersing the hollow microparticles of the present invention and, if necessary, other ingredients to produce a curable composition, and then curing the curable composition.
The method for producing the curable composition is not particularly limited, but a mixture is prepared by mixing the hollow microparticles of the present invention and a compound having an iso(thio)cyanate group, and two active hydrogen groups are added to the mixture. A method of adding a compound having one or more is mentioned. Then, the cured product of the present invention can be obtained by curing the curable composition.

The curing method is not particularly limited, and a known method may be adopted. For example, the conditions described in International Publication No. WO2015/068798, International Publication No. WO2016/143910, and WO2018-092826 can be adopted. Specifically, a one-pot method, a dry method such as a prepolymer method, a wet method using a solvent, or the like can be used. Among them, the dry method is preferably employed.

The amount of the hollow microparticles of the present invention to be added to the polyurethane resin is 0.1 to 20 parts by mass of the hollow microparticles of the present invention per 100 parts by mass of components (c) and (d) combined. is preferable, 0.2 to 10 parts by mass is more preferable, and 0.5 to 8 parts by mass is even more preferable. By setting the content within this range, it is possible to exhibit excellent polishing properties.

In the present invention, polyurethane resin is a generic term for polyurethane resin, polyurea resin, and polyurethane urea resin. Further, the polyurethane resin of the present invention includes polythiourethane resin and polythiourethane resin.

Below, each component will be explained in detail.

<(c) polyfunctional isocyanate compound>
In the present invention, a known compound can be used as the component (c), but a compound (d1) having two isocyanate groups and curable active hydrogen groups in one molecule (hereinafter referred to as " (d1) component”) and (c1) a bifunctional iso(thio)cyanate group-containing compound having two iso(thio)cyanate groups in the molecule (hereinafter referred to as “(c1) component” or “bifunctional A urethane prepolymer having iso(thio)cyanate groups at both ends of the molecule obtained by reacting with a compound containing an iso(thio)cyanate group) is suitable. In the present invention, the iso(thio)cyanate group refers to an isocyanate group or an isothiocyanate group. Therefore, having two iso(thio)cyanate groups in the molecule means having two isocyanate groups, having two isothiocyanate groups, or having one isocyanate group and one isothiocyanate group. refers to any of

These (c) components can be used without any limitation as long as they contain iso(thio)cyanate groups at both ends of the molecule, and may be used alone or in combination of two or more.

In the present invention, the component (c) or the component (c1), which is the raw material for the urethane prepolymer, includes, for example, the polymerizable monomers described in International Publication No. 2019/198675.

Among them, specifically, 1,5-naphthalene diisocyanate, xylene diisocyanate (o-, m-, p-), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, phenylene diisocyanate (o-, m-, p-), 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane-4, It is preferable to use 4′-diisocyanate, (bicyclo[2.2.1]heptane-2,5(2,6)-diyl)bismethylene diisocyanate, more preferably aromatic isocyanate, 2,4-tri Urethane prepolymers composed of diisocyanate or 2,6-tolylene diisocyanate are most preferred.

Further, in order for the cured product obtained by curing the curable composition of the present invention to exhibit particularly excellent properties, at least one (d1) component having a number average molecular weight of 300 to 1500 is used. It is preferred to produce the urethane prepolymer.

The (d1) component with a number average molecular weight of 300 to 1,500 can be used in combination of different types and different molecular weights. At that time, the components (d1) may be combined so that the total number average molecular weight of the component (d1) is 300 to 1,500.

In addition, in order to adjust the hardness and strength of the obtained cured product, when producing the urethane prepolymer, the component (d1) having a number average molecular weight of 300 to 1,500 and the component (d1) having a number average molecular weight of 90 It can also be used in combination with ˜300 (d1) components. In this case, depending on the type of component (d1) and component (c1) used, and the amounts thereof used, when the component (d1) with a molecular weight of 300 to 1500 is 100 parts by mass, the molecular weight of 90 to 300 Component (d1) is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, and most preferably 5 to 30 parts by mass.

In addition, component (c) must have isocyanate groups and/or isothiocyanate groups at both ends of the molecule. Therefore, component (c) consists of the total number of moles of isocyanate groups and/or isothiocyanate groups in component (c) (n5), and the total number of moles of hydroxyl groups, thiol groups, and amino groups in component (d) (n6). is preferably manufactured within the range of 1<(n5)/(n6)≦2.3. When two or more types of component (c) are used, the number of moles (n5) of the isocyanate groups and/or isothiocyanate groups is, of course, the total number of moles of the isocyanate groups and/or isothiocyanate groups of component (c). The number of moles (n6) of hydroxyl groups, thiol groups and amino groups of two or more types of component (d1) is, of course, the total number of moles of all hydroxyl groups, thiol groups and amino groups.

As the component (d1), those described in the explanation of the component (d) below can be used, and the preferred component (d1) is a polyester polyol, a polyether polyol, a polycarbonate polyol, or the like. Among them, component (d1) consisting of polyoxytetramethylene glycol, polypropylene glycol, polyethylene glycol, diethylene glycol and the like is most preferred.

The iso(thio)cyanate equivalent (total amount of isocyanate equivalents and/or isothiocyanate equivalents) of component (c) is determined by quantifying the isocyanate groups and/or isothiocyanate groups possessed by component (c) in accordance with JIS K 7301. can be obtained by The isocyanate group and/or isothiocyanate group can be quantified by the following back titration method. First, the obtained component (c) is dissolved in a dry solvent. Next, di-n-butylamine, which is clearly in excess of the amount of isocyanate groups and/or isothiocyanate groups possessed by component (c) and has a known concentration, is added to the dry solvent, and (c ) reacting all isocyanate groups and/or isothiocyanate groups of the component with di-n-butylamine. The unconsumed (did not participate in the reaction) di-n-butylamine is then titrated with acid to determine the amount of di-n-butylamine consumed. Since the consumed di-n-butylamine and the isocyanate groups and/or isothiocyanate groups of component (c) are the same, the iso(thio)cyanate equivalent can be determined. In addition, since component (c) is a straight-chain urethane prepolymer having isocyanate groups and/or isothiocyanate groups at both ends, the number average molecular weight of component (c) is the iso(thio)cyanate equivalent of 2 be doubled. The molecular weight of this component (c) tends to match the value measured by gel permeation chromatography (GPC).

The iso(thio)cyanate equivalent of component (c) is not particularly limited, but the iso(thio)cyanate equivalent in the present invention is preferably 300 to 2000, more preferably 350 to 1500, and 400 ~1000 is most preferred. The reason for this is considered as follows. That is, when the component (c) having a certain molecular weight reacts with the component (d) to form a cured product, the working sites of the molecules including the side chains increase and the movement of the molecules themselves increases. It is considered that recovery from deformation (elastic recovery; low hysterics) is facilitated. Furthermore, it is believed that the use of component (c) facilitates the dispersion of the cross-linking points in the cured product, and makes them exist randomly and uniformly, thereby exhibiting stable performance. When the component (c) is in the range described above, the resulting curable composition is excellent in handleability, making it easier to control during production and improving moldability. For example, when a cured body obtained by curing the curable composition of the present invention is used as a polishing pad, a polishing pad having excellent moldability can be produced.

The method for producing the urethane prepolymer used in the present invention is not particularly limited, and the component (c1) and the component (d1) are reacted by a known method to form an isocyanate group and/or an isothiocyanate group at the end of the molecule. The urethane prepolymer having

In addition, for the production of the component (c), it can be produced by heating or adding a urethanization catalyst as necessary.

<(d) Compound Having Two or More Isocyanate Groups and Curable Active Hydrogen Groups>
Component (d) can be used without limitation as long as it is a compound having at least two groups selected from the group consisting of hydroxyl groups, thiol groups and amino groups in one molecule. Of course, compounds having any two or all of hydroxyl, thiol and amino groups are also selected. In addition, as described above, a compound having two curable active hydrogen groups and an isocyanate group in one molecule corresponds to the component (d1).

Among them, as the component (d), in addition to the component (d1) used for synthesizing the urethane prepolymer, a compound (da) having two or more amino groups (hereinafter also referred to as "(da) component"). and more preferably (db) a compound having 3 or more hydroxyl groups and/or thiol groups (hereinafter also referred to as "(db) component") . In the present invention, a compound having n or more hydroxyl groups and/or thiol groups means that the total number of hydroxyl groups and thiol groups in the compound is n or more. A compound having no hydroxyl group, a compound having a thiol group but no hydroxyl group, or a compound having both a hydroxyl group and a thiol group may be used.

Above all, it is particularly preferable that the (db) component is a compound having 5 or more hydroxyl groups and/or thiol groups. The number of moles of hydroxyl groups and/or thiol groups per mass of component (db) is preferably 0.5 mmol/g to 35 mmol/g, more preferably 0.8 mmol/g to 20 mmol/g.

((da) compound having two or more amino groups; component (da))
The component (da) can be used without limitation as long as it is a compound having two or more primary and/or secondary amino groups in one molecule. The compounds having two or more amino groups are roughly classified into aliphatic amines, alicyclic amines, aromatic amines, and polyrotaxanes having an amino group polymerizable with an isocyanate group.

Aliphatic amine; component (da) Bifunctional amines such as ethylenediamine, hexamethylenediamine, nonamethylenediamine, undecanemethylenediamine, dodecamethylenediamine, metaxylenediamine, 1,3-propanediamine, and putrescine (constituting the urethane prepolymer) corresponds to the (d1) component).

Polyfunctional amines such as polyamines such as diethylenetriamine.

Alicyclic amine; (da) component Bifunctional amines such as isophoronediamine and cyclohexyldiamine (corresponding to component (d1) constituting the urethane prepolymer).

aromatic amine; (da) component 4,4'-methylenebis(o-chloroaniline) (MOCA), 2,6-dichloro-p-phenylenediamine, 4,4'-methylenebis(2,3-dichloroaniline), 4,4′-methylenebis(2-ethyl-6-methylaniline), 3,5-bis(methylthio)-2,4-toluenediamine, 3,5-bis(methylthio)-2,6-toluenediamine, 3 ,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, trimethylene glycol-di-p-aminobenzoate, polytetramethylene glycol-di-p-aminobenzoate, 4, 4'-diamino-3,3',5,5'-tetraethyldiphenylmethane, 4,4'-diamino-3,3'-diisopropyl-5,5'-dimethyldiphenylmethane, 4,4'-diamino-3,3 ',5,5'-tetraisopropyldiphenylmethane, 1,2-bis(2-aminophenylthio)ethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, N,N '-di-sec-butyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, m-xylylenediamine, N,N'-di-sec-butyl-p- Phenylenediamine, m-phenylenediamine, p-xylylenediamine, p-phenylenediamine, 3,3′-methylenebis(methyl-6-aminobenzoate), 2,4-diamino-4-chlorobenzoate-2-methylpropyl , 2,4-diamino-4-chlorobenzoic acid-isopropyl, 2,4-diamino-4-chlorophenylacetic acid-isopropyl, terephthalic acid-di-(2-aminophenyl)thioethyl, diphenylmethanediamine, tolylenediamine, piperazine, etc. (corresponding to the (d1) component constituting the urethane prepolymer).

　Multifunctional amines such as 1,3,5-benzenetriamine and melamine.

Polyrotaxane Having Amino Group; Component (da) The polyrotaxane having an amino group used in the present invention is not particularly limited.

Among the (da) components used in the present invention, preferred are 4,4'-methylenebis(o-chloroaniline) (MOCA), 4,4'-diamino-3,3'-diethyl-5,5' -dimethyldiphenylmethane, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, 3,5-bis(methylthio)-2,4-toluenediamine, 3,5- bis(methylthio)-2,6-toluenediamine, trimethylene glycol-di-p-aminobenzoate.

Compounds having a hydroxyl group and/or a thiol group among the component (d) can be broadly classified into aliphatic alcohols, alicyclic alcohols, aromatic alcohols, polyester polyols, polyether polyols, polycaprolactone polyols, and polycarbonates. Polyols, polyacrylic polyols, castor oil-based polyols, compounds having two or more thiol groups, hydroxyl group- and thiol-type polymerizable group-containing monomers, side chain-containing cyclic compounds having three or more hydroxyl groups and/or thiol groups, and It is classified as a polyrotaxane having hydroxyl groups and/or thiol groups. Specific examples include the following.

((d) compound having two or more hydroxyl groups; component (d))
Aliphatic alcohol; component (d) ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, 1,5-dihydroxypentane, 1,6-dihydroxyhexane, 1,7-dihydroxyheptane, 1,8-dihydroxyoctane , 1,9-dihydroxynonane, 1,10-dihydroxydecane, 1,11-dihydroxyundecane, 1,12-dihydroxydodecane, neopentyl glycol, glyceryl monooleate, monoelaidin, polyethylene glycol, 3-methyl-1, Bifunctional polyols such as 5-dihydroxypentane, dihydroxyneopentyl, 2-ethyl-1,2-dihydroxyhexane, 2-methyl-1,3-dihydroxypropane (corresponding to component (d1) constituting the urethane prepolymer ).

Glycerin, trimethylolethane, trimethylolpropane, ditrimethylolpropane, trimethylolpropane tripolyoxyethylene ether (for example, TMP-30, TMP-60, TMP-90, etc. of Nippon Nyukazai Co., Ltd.), butanetriol, 1,2- Methyl glucoside, pentaerythritol, dipentaerythritol, tripentaerythritol, sorbitol, erythritol, threitol, ribitol, arabinitol, xylitol, allitol, mannitol, dolcitol, iditol, glycol, inositol, hexanetriol, triglycerol, diglycerol, triethylene Polyfunctional polyols such as glycol (corresponding to the (db) component).

Alicyclic alcohol; Component (d) Hydrogenated bisphenol A, cyclobutanediol, cyclopentanediol, cyclohexanediol, cycloheptanediol, cyclooctanediol, cyclohexanedimethanol, hydroxypropylcyclohexanol, tricyclo[5,2,1,0 ^2,6 ]decane-dimethanol, bicyclo[4,3,0]-nonanediol, dicyclohexanediol, tricyclo[5,3,1,13,9]dodecanediol, bicyclo[4,3,0]nonanediol methanol, tricyclo[5,3,1,1 ^3,9 ]dodecan-diethanol, hydroxypropyltricyclo[5,3,1,1 ^3,9 ]dodecanol, spiro[3,4]octanediol, butylcyclohexanediol, Bifunctional polyols such as 1,1′-bicyclohexylidene diol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, and o-dihydroxyxylylene (the urethane prepolymer It corresponds to the (d1) component that constitutes the polymer).

Polyfunctional polyols such as tris(2-hydroxyethyl) isocyanurate, cyclohexanetriol, sucrose, maltitol and lactitol (corresponding to the above (db) component).

Aromatic alcohol; component (d) dihydroxynaphthalene, dihydroxybenzene, bisphenol A, bisphenol F, xylylene glycol, tetrabromobisphenol A, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane , 1,2-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)phenylmethane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)-1-naphthylmethane, 1,1- Bis(4-hydroxyphenyl)-1-phenylethane, 2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis (4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)-3-methylbutane, 2,2-bis(4-hydroxyphenyl)pentane, 3,3-bis(4-hydroxyphenyl)pentane, 2,2-bis(4-hydroxyphenyl)hexane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 2,2-bis(4 -hydroxyphenyl)heptane, 4,4-bis(4-hydroxyphenyl)heptane, 2,2-bis(4-hydroxyphenyl)tridecane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis (3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-ethyl-4-hydroxyphenyl)propane, 2,2-bis(3-n-propyl-4-hydroxyphenyl)propane, 2, 2-bis(3-isopropyl-4-hydroxyphenyl)propane, 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-tert-butyl-4-hydroxyphenyl) ) propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2,2-bis(3-allyl-4′-hydroxyphenyl)propane, 2,2-bis(3-methoxy-4- hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(2,3,5,6-tetramethyl-4-hydroxyphenyl)propane, bis( 4-hydroxyphenyl)cyanomethane, 1-cyano-3,3-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1-bis(4-hydroxyphenyl) Cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cycloheptane, 1,1-bis(3-methyl-4-hydroxyphenyl)cyclohexane, 1,1 -bis(3,5-dimethyl-4-hydroxyphenyl)cyclohexane, 1,1-bis(3,5-dichloro-4-hydroxyphenyl)cyclohexane, 1,1-bis(3-methyl-4-hydroxyphenyl) -4-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxyphenyl)norbornane, 2,2-bis(4-hydroxyphenyl ) adamantane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, ethylene glycol bis(4-hydroxyphenyl) ether, 4,4′-dihydroxydiphenyl sulfide, 3,3′ -dimethyl-4,4'-dihydroxydiphenyl sulfide, 3,3'-dicyclohexyl-4,4'-dihydroxydiphenyl sulfide, 3,3'-diphenyl-4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy Diphenyl sulfoxide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone, bis(4-hydroxyphenyl ) ketone, bis(4-hydroxy-3-methylphenyl)ketone, 7,7′-dihydroxy-3,3′,4,4′-tetrahydro-4,4,4′,4′-tetramethyl-2, 2′-spirobi(2H-1-benzopyran), trans-2,3-bis(4-hydroxyphenyl)-2-butene, 9,9-bis(4-hydroxyphenyl)fluorene, 3,3-bis(4 -hydroxyphenyl)-2-butanone, 1,6-bis(4-hydroxyphenyl)-1,6-hexanedione, 4,4'-dihydroxybiphenyl, m-dihydroxyxylylene, p-dihydroxyxylylene, 1, 4-bis(2-hydroxyethyl)benzene, 1,4-bis(3-hydroxypropyl)benzene, 1,4-bis(4-hydroxybutyl)benzene, 1,4-bis(5-hydroxypentyl)benzene, 1,4-bis(6-hydroxyhexyl)benzene, 2,2-bis[4-(2″-hydroxyethyloxy)phenyl]propane, and bifunctional polyols such as hydroquinone and resorcinol (constituting the urethane prepolymer) corresponds to the (d1) component).

Polyfunctional polyols such as trihydroxynaphthalene, tetrahydroxynaphthalene, benzenetriol, biphenyltetraol, pyrogallol, (hydroxynaphthyl)pyrogallol, and trihydroxyphenanthrene (corresponding to the (db) component).

Polyester polyol; component (d) Examples include compounds obtained by a condensation reaction between a polyol and a compound having multiple carboxylic acids. Among them, the number average molecular weight is preferably from 400 to 2,000, more preferably from 500 to 1,500, and most preferably from 600 to 1,200. Those having hydroxyl groups only at both ends of the molecule (two in the molecule) correspond to the (d1) component constituting the urethane prepolymer, and those having three or more hydroxyl groups in the molecule are the above (db ) corresponds to the component.

Here, the polyols include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 3,3′-dimethylolheptane, 1,4-cyclohexanedimethanol, neopentyl glycol, 3,3-bis(hydroxymethyl)heptane, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane and the like, which are Even if it uses individually, it does not matter even if it mixes and uses two or more types. Examples of compounds having a plurality of carboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, orthophthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. and the like, and these may be used alone or in combination of two or more.

These polyester polyols are commercially available as reagents or industrially. Examples of commercially available products include the "Polylite (registered trademark)" series manufactured by DIC Corporation, and the "Nipporan (registered trademark)" manufactured by Nippon Polyurethane Industry Co., Ltd. )” series, the “Maximol (registered trademark)” series manufactured by Kawasaki Chemical Industries, Ltd., and the “Kuraray Polyol (registered trademark)” series manufactured by Kuraray Co., Ltd., and the like.

Polyether Polyol; Component (d) Examples include compounds obtained by ring-opening polymerization of alkylene oxide or reaction of a compound having two or more active hydrogen groups in the molecule with alkylene oxide, and modified products thereof. Among them, the number average molecular weight is preferably from 400 to 2,000, more preferably from 500 to 1,500, and most preferably from 600 to 1,200. Those having hydroxyl groups only at both ends of the molecule (two in the molecule) correspond to the (d1) component constituting the urethane prepolymer, and those having three or more hydroxyl groups in the molecule are the above (db ) corresponds to the component.

Here, examples of the polyether polyols include polymer polyols, urethane-modified polyether polyols, polyether ester copolymer polyols, and the like. Examples of the compounds having two or more active hydrogen groups in the molecule include water, ethylene Glycol, propylene glycol, butanediol, glycerin, trimethylolpropane, hexanetriol, triethanolamine, diglycerin, pentaerythritol, trimethylolpropane, hexanetriol, and other polyols such as glycols and glycerin having one or more hydroxyl groups in the molecule compounds, and these may be used alone or in combination of two or more.

The alkylene oxides include cyclic ether compounds such as ethylene oxide, propylene oxide, and tetrahydrofuran, and these may be used alone or in combination of two or more.

Such polyether polyols are commercially available as reagents or industrially. ADEKA CORPORATION "ADEKA POLYETHER" series and the like can be mentioned.

Polycaprolactone Polyol; Component (d) Examples include compounds obtained by ring-opening polymerization of ε-caprolactone. Among them, the number average molecular weight is preferably from 400 to 2,000, more preferably from 500 to 1,500, and most preferably from 600 to 1,200. Those having hydroxyl groups only at both ends of the molecule (two in the molecule) correspond to the (d1) component constituting the urethane prepolymer, and those having three or more hydroxyl groups in the molecule are the above (db ) corresponds to the component.

These polycaprolactone polyols are commercially available as reagents or industrially. Examples of commercially available products include the "PLAXEL (registered trademark)" series manufactured by Daicel Chemical Industries, Ltd.

Polycarbonate polyol; component (d) A compound obtained by phosgenation of one or more low-molecular-weight polyols or a compound obtained by transesterification using ethylene carbonate, diethyl carbonate, diphenyl carbonate or the like can be mentioned. Among them, the number average molecular weight is preferably from 400 to 2,000, more preferably from 500 to 1,500, and most preferably from 600 to 1,200. Those having hydroxyl groups only at both ends of the molecule (two in the molecule) correspond to the (d1) component constituting the urethane prepolymer, and those having three or more hydroxyl groups in the molecule are the above (cd ) corresponds to the component.

Here, the low-molecular-weight polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, and 1,3-butane. diol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 3-methyl-1, 5-pentanediol, 2-ethyl-4-butyl-1,3-propanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer acid diol , ethylene oxide and propylene oxide adducts of bisphenol A, bis(β-hydroxyethyl)benzene, xylylene glycol, glycerin, trimethylolpropane, pentaerythritol and other low-molecular-weight polyols.

Polyacrylic Polyol; Component (d) Examples include polyol compounds obtained by polymerizing (meth)acrylate acid esters and vinyl monomers. Those having hydroxyl groups only at both ends of the molecule (two in the molecule) correspond to the (d1) component constituting the urethane prepolymer, and those having three or more hydroxyl groups in the molecule are the above (db ) corresponds to the component.

Castor oil-based polyol; component (d) Examples of castor oil-based polyols include polyol compounds starting from castor oil, which is a natural oil. In addition, those having hydroxyl groups only at both ends of the molecule (two in the molecule) correspond to the (d1) component constituting the urethane prepolymer, and those having three or more hydroxyl groups in the molecule are the above-mentioned (db) corresponds to the component.

These castor oil polyols are commercially available as reagents or industrially, and examples of commercially available products include the "URIC (registered trademark)" series manufactured by Ito Seiyu Co., Ltd.

((d) compound having two or more thiol groups)
Preferred specific examples of the compound having two or more thiol groups among the component (d) include those described in International Publication No. WO2015/068798 pamphlet. Among them, the following are particularly preferred examples.

Tetraethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bis(3-mercaptopropionate), 1,6-hexanediol bis(3-mercaptopropionate), 1,4-bis (mercaptopropylthiomethyl)benzene (corresponding to component (d1) constituting the urethane prepolymer);

Trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), 1,2-bis [(2-mercaptoethyl ) Thio]-3-mercaptopropane, 2,2-bis(mercaptomethyl)-1,4-butanedithiol, 2,5-bis(mercaptomethyl)-1,4-dithiane, 4-mercaptomethyl-1,8 -dimercapto-3,6-dithiaoctane, 1,1,1,1-tetrakis(mercaptomethyl)methane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 1,1,2,2-tetrakis(mercapto Thiols such as methylthio)ethane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, tris-{(3-mercaptopropionyloxy)ethyl}-isocyanurate (corresponding to the above component (db)).

((d) hydroxyl group and thiol group polymerizable group-containing monomer)
Examples of compounds containing both a hydroxyl group and a thiol group in the component (d) include the following.

2-mercaptoethanol, 1-hydroxy-4-mercaptocyclohexane, 2-mercaptohydroquinone, 4-mercaptophenol, 1-hydroxyethylthio-3-mercaptoethylthiobenzene, 4-hydroxy-4'-mercaptodiphenylsulfone, 2- (2-Mercaptoethylthio)ethanol, dihydroxyethyl sulfide mono(3-mercaptopropionate), dimercaptoethane mono(salcylate) (corresponding to component (d1) constituting the urethane prepolymer).

3-mercapto-1,2-propanediol, glycerindi (mercaptoacetate), 2,4-dimercaptophenol, 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 1,2-dimercapto -1,3-butanediol, pentaerythritol tris (3-mercaptopropionate), pentaerythritol mono (3-mercaptopropionate), pentaerythritol bis (3-mercaptopropionate), pentaerythritol tris (thioglyco rate), pentaerythritol pentakis(3-mercaptopropionate), hydroxymethyl-tris(mercaptoethylthiomethyl)methane, hydroxyethylthiomethyltris(mercaptoethylthio)methane, etc. group-containing monomer (corresponding to the (db) component);

Side chain-containing cyclic molecule having 3 or more hydroxyl groups and/or thiol groups; component (db) In the present invention, any cyclic molecule containing a side chain having 3 or more hydroxyl groups and/or thiol groups at the terminal is particularly restricted. not. For example, underlying cyclic molecules include cyclodextrin, crown ether, benzocrown, dibenzocrown, dicyclohexanocrown, cyclobis(paraquat-1,4-phenylene), dimethoxypyraarene, calixarene, and phenanthroline. Among them, cyclodextrin is preferred.

The cyclodextrin has an α form (ring inner diameter 0.45 to 0.6 nm), a β form (ring inner diameter 0.6 to 0.8 nm), and a γ form (ring inner diameter 0.8 to 0.95 nm). Mixtures of these can also be used. In the present invention, α-cyclodextrin and β-cyclodextrin are particularly preferred.

Next, the side chains having at least three hydroxyl groups and/or thiol groups at the ends that are introduced into the cyclic molecule will be described. Although the method for introducing the side chain is not limited, for example, it can be introduced by utilizing the reactive functional group possessed by the cyclic molecule and modifying this reactive functional group (that is, the side chain can be introduced by modifying the reactive functional group introduced by reacting with the group).

Examples of the reactive functional group include hydroxyl group and amino group, among which hydroxyl group is preferred. For example, α-cyclodextrin has 18 hydroxyl groups as reactive functional groups, and the hydroxyl groups are reacted to introduce side chains. Therefore, up to 18 side chains can be introduced into one α-cyclodextrin. In the present invention, at least 3 or more side chains having hydroxyl groups and/or thiol groups introduced at their ends must be introduced in order to sufficiently exhibit the functions of the side chains described above. Among them, it is preferable that 5 or more side chains having hydroxyl groups and/or thiol groups introduced at the terminals are introduced, and 7 or more side chains having hydroxyl groups and/or thiol groups introduced at the terminals are introduced. More preferably, 8 or more side chains having hydroxyl groups and/or thiol groups introduced at the terminals are most preferably introduced. Moreover, a side chain having a terminal hydroxyl group is particularly preferred.

Although the side chain is not particularly limited, it is preferably formed by repeating an organic chain having 3 to 20 carbon atoms. The number average molecular weight of such side chains is preferably 300 or more, for example. More particularly, the number average molecular weight of such side chains ranges from 300 to 10,000, preferably from 350 to 5,000, most preferably from 400 to 5,000. The number average molecular weight of this side chain can be adjusted by adjusting the amount used when the side chain is introduced, and can be determined by calculation or by ¹ H-NMR measurement.

By setting the lower limit of the number average molecular weight of the side chain as above, excellent mechanical properties are exhibited, and when used in the CMP polishing pad of the present invention, the polishing rate tends to be improved.

In the present invention, the side chain may be linear or branched. For the introduction of side chains, it is possible to appropriately introduce the methods and compounds disclosed in WO 2015/159875, for example, ring-opening polymerization; radical polymerization; cationic polymerization; anionic polymerization; Polymerization, RAFT polymerization, living radical polymerization such as NMP polymerization, and the like can be used. By the above method, a side chain having an appropriate size can be introduced by reacting an appropriately selected compound with the reactive functional group of the cyclic molecule.

Among them, ring-opening polymerization is particularly preferable, and it is preferable to introduce side chains derived from cyclic compounds such as cyclic ethers, cyclic lactones, cyclic acetals, and cyclic carbonates.

Among the cyclic compounds, it is preferable to use cyclic ethers, cyclic lactones, and cyclic carbonates from the viewpoints of high reactivity and ease of molecular weight adjustment.

Preferred cyclic ethers, cyclic lactones, and cyclic carbonates are exemplified below.

cyclic ethers;
ethylene oxide, 1,2-propylene oxide, epichlorohydrin, epibromohydrin, 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide, oxetane, 3-methyloxetane, 3,3-dimethyloxetane, Tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, etc. Cyclic lactones;
4-membered ring lactone; β-propiolactone, β-methylpropiolactone, L-serine-β-lactone, etc. 5-membered ring lactone; γ-butyrolactone, γ-hexanolactone, γ-heptanolactone, γ-octa Nolactone, γ-decanolactone, γ-dodecanolactone, α-hexyl-γ-butyrolactone, α-heptyl-γ-butyrolactone, α-hydroxy-γ-butyrolactone, γ-methyl-γ-decanolactone, α-methylene-γ -butyrolactone, α,α-dimethyl-γ-butyrolactone, D-erythronolactone, α-methyl-γ-butyrolactone, γ-nonanolactone, DL-pantolactone, γ-phenyl-γ-butyrolactone, γ-undecanolactone, γ-valerolactone, 2,2-pentamethylene-1,3-dioxolane-4-one, α-bromo-γ-butyrolactone, γ-crotonolactone, α-methylene-γ-butyrolactone, α-methacryloyloxy-γ -Butyrolactone, β-methacryloyloxy-γ-butyrolactone, etc. Six-membered ring lactones; Dodecanolactone, δ-tridecanolactone, δ-tetradecanolactone, DL-mevalonolactone, 4-hydroxy-1-cyclohexanecarboxylic acid δ-lactone, monomethyl-δ-valerolactone, monoethyl-δ-valerolactone, monohexyl- δ-valerolactone, 1,4-dioxan-2-one, 1,5-dioxepan-2-one, etc. 7-membered ring lactone; ε-caprolactone, monomethyl-ε-caprolactone, monoethyl-ε-caprolactone, monohexyl-ε- Caprolactone, dimethyl-ε-caprolactone, di-n-propyl-ε-caprolactone, di-n-hexyl-ε-caprolactone, trimethyl-ε-caprolactone, triethyl-ε-caprolactone, tri-n-ε-caprolactone, ε- Caprolactone, 5-nonyl-oxepan-2-one, 4,4,6-trimethyl-oxepan-2-one, 4,6,6-trimethyl-oxepan-2-one, 5-hydroxymethyl-oxepan-2-one 8-membered ring lactone; ζ-enantholactone, etc. Other lactones; lactone, lactide, dilactide, tetramethylglycoside, 1,5-dioxepan-2-one, t-butylcaprolactone, etc. Cyclic carbonate;
Ethylene carbonate, propylene carbonate, 1,2-butylene glycerol carbonate 1,2-carbonate, 4-(methoxymethyl)-1,3-dioxolan-2-one, (chloromethyl) ethylene carbonate, vinylene carbonate, 4,5- Dimethyl-1,3-dioxol-2-one, 4-chloromethyl-5-methyl-1,3-dioxol-2-one, 4-vinyl-1,3-dioxolan-2-one, 4,5-diphenyl -1,3-dioxolan-2-one, 4,4-dimethyl-5-methylene-1,3-dioxolan-2-one, 1,3-dioxan-2-one, 5-methyl-5-propyl-1 ,3-dioxolan-2-one, 5,5-diethyl-1,3-dioxolan-2-one The above cyclic compounds may be used alone or in combination of two or more.

In the present invention, the cyclic compound preferably used is a lactone compound, and particularly preferred lactone compounds are ε-caprolactone, α-acetyl-γ-butyrolactone, α-methyl-γ-butyrolactone, γ-valerolactone, γ - lactone compounds such as butyrolactone, most preferably ε-caprolactone.

In addition, when side chains are introduced by reacting cyclic compounds by ring-opening polymerization, the reactive functional groups (e.g., hydroxyl groups) of cyclic molecules are poor in reactivity, and it is difficult to directly react large molecules, especially due to steric hindrance. There are cases. In such a case, for example, in order to react caprolactone or the like described above, a low-molecular-weight compound such as propylene oxide is once reacted with the reactive functional group of the cyclic molecule to hydroxypropylate it, thereby preliminarily reacting the reactive functional group. A method of introducing functional groups rich in is preferred. After that, a means of introducing a side chain by ring-opening polymerization using the above-described cyclic compound can be adopted. In this case, the hydroxypropylated moieties can also be considered side chains.

Polyrotaxane having hydroxyl group and/or thiol group; component (d) It is also called a supramolecule, which is a molecular complex having a structure in which a cyclic molecule cannot come off from an axial molecule due to steric hindrance. The polyrotaxane that can be used as the component (d) of the present invention is a polyrotaxane having a hydroxyl group and/or a thiol group polymerizable with an isocyanate group, and those having three or more hydroxyl groups and/or thiol groups are included in the component (db). Applicable. Although the polyrotaxane having a hydroxyl group and/or a thiol group used in the component (d) of the present invention is not particularly limited, for example, the polyrotaxane described in International Application No. 2018/092826 is exemplified.

Preferred among the (db) components used in the present invention are glycerin, trimethylolethane, trimethylolpropane, ditrimethylolpropane, trimethylolpropane tripolyoxyethylene ether (TMP-30 of Nippon Emulsifier Co., Ltd.), and hydroxyl groups 3 or more polyester polyols, polyether polyols with 3 or more hydroxyl groups, castor oil-based polyols with 3 or more hydroxyl groups, side chain-containing cyclic compounds with 3 or more hydroxyl groups, polyrotaxanes with hydroxyl groups and/or thiol groups For example, a side chain-containing cyclic compound having 3 or more hydroxyl groups, a polyrotaxane having 3 or more hydroxyl groups and/or thiol groups is more preferable, and from the viewpoint of handling, a side chain having 3 or more hydroxyl groups and/or thiol groups Containing cyclic compounds are most preferred.

<Mixing ratio of component (c) and component (d)>
In the present invention, the mixing ratio of component (c) and component (d) is not particularly limited. Above all, in order to exhibit an excellent effect, the total number of moles of active hydrogen groups in component (d) is 0.8 when the total number of iso(thio)cyanate groups in component (c) is 1 mol. It is preferable to be ˜2.0 mol. If the iso(thio)cyanate groups are too many or too few, the resulting polyurethane resin tends to be poorly cured or have reduced abrasion resistance. In order to obtain a polyurethane resin having a better cured state, a uniform state, and excellent wear resistance, the total number of the active hydrogen groups should be 1 mol when the total number of the iso(thio)cyanate groups is 1 mol. The number of moles is more preferably 0.85 to 1.75 mol, more preferably 0.9 to 1.5 mol. When calculating the total number of moles of active hydrogen groups in the component (d), if a compound (ca) having two or more amino groups is used, the active hydrogen of the compound having two or more amino groups shall be equal to the number of moles of amino groups.

In the present invention, in order to develop excellent polishing properties, as described above, the component (d) preferably contains the component (da), and further contains the component (da) and the component (db). It is more preferable to be

That is, in the present invention, it is preferable to contain the (c) component and the (da) component, and it is more preferable to contain the (c) component, the (da) component and the (db) component.

For example, when the component (c), the component (da), and the component (db) are included, the blending ratio of each component is It is preferable to contain 60 to 95 parts by mass of component (c), 2 to 20 parts by mass of component (da), and 1 to 30 parts by mass of component (db), and 70 to 85 parts by mass of component (c). It is more preferable to contain 2 to 15 parts by mass of component (da) and 3 to 25 parts by mass of component (db).

<Other ingredients>
As other compounding ingredients used in the present invention, various known compounding agents can be used as long as they do not impair the effects of the present invention. For example, curing catalysts, abrasive grains, surfactants, flame retardants, plasticizers, fillers, antistatic agents, foam stabilizers, solvents, leveling agents, and other additives may be added. These additives may be used alone or in combination of two or more.

As the curing catalyst, these reaction catalysts for urethane or urea can be catalysts that can be used when the fine hollow particles are urethane (urea) resins, and may be used alone or in combination of two or more. However, the amount used may be a so-called catalytic amount, for example, 0.001 to 10 parts by mass, particularly 0.01 to 5 parts by mass, per 100 parts by mass of components (c) and (d). Part range is fine.

As the abrasive grains, for example, particles made of a material selected from cerium oxide, silicon oxide, alumina, silicon carbide, zirconia, iron oxide, manganese dioxide, titanium oxide and diamond, or two or more kinds of these materials and the like.

Next, the present invention will be described in detail using examples and comparative examples, but the present invention is not limited to these examples. Components and evaluation methods used in the following examples and comparative examples are as follows.

(Micro hollow particles)
[Measuring method]
(1) Average particle size, yield The obtained micro hollow particles were measured with a field emission scanning electron microscope (manufactured by JEOL, JSM-7800FPrime), and the electron micrograph was measured, and the image analysis software ImageJ (National Institutes) of Health), the particle diameters of at least 50 individual hollow microparticles were measured, and the average particle diameter was calculated as the average value of these. For the yield, the shape of at least 50 hollow microparticles was confirmed, and the percentage of hollow microparticles that were neither dented nor broken was taken as the yield.

(2) Ash This is the ratio between the mass of the combustion residue after burning the hollow microparticles at a temperature of 600°C and the mass of the hollow microparticles before combustion.

<Example 1>
Styrene-maleic anhydride copolymer (Scripset 520 (manufactured by Monsanto, weight average molecular weight 350,000)) as a surfactant while heating 55 ml of a 2% aqueous sodium hydroxide solution as an aqueous phase to 70° C.: 3.5 g was dissolved, 35 g of chlorobenzene was added as an oil phase to the aqueous phase, and stirred at 1500 rpm for 10 minutes at 80°C with a homogenizer to prepare an O/W emulsion. Also, melamine: 4.54 g, 37% formaldehyde aqueous solution: 11.69 ml, and distilled water: 7.12 g are mixed at 70 ° C., and then pH is adjusted using 10% sodium hydroxide aqueous solution: 5 ml. Then, after preparing an alkaline aqueous solution of melamine formaldehyde prepolymer compound at 70° C. and pH 12, the entire amount was added to and mixed with the O/W emulsion obtained above. After that, a 10% aqueous citric acid solution was added to confirm that the pH was 4 or less, and the mixture was stirred and mixed at 150 rpm and reacted at a liquid temperature of 80° C. for 4 hours to generate microparticles. The microparticles thus obtained were placed in a centrifugal filter and centrifuged at 1000 rpm for 5 minutes five times to remove the aqueous phase and obtain a solid. 50 g of the obtained solid was slurried in 100 g of ethanol, filtered through a filter paper with a mesh size of 1 μm, and placed in a high-pressure container. Extracted with supercritical carbon dioxide for 45 minutes at min. After that, the pressure was reduced to atmospheric pressure over 15 minutes to obtain fine hollow particles. It was confirmed by TG measurement that chlorobenzene was removed from the obtained hollow microparticles. The average particle size was 23 µm. The hollow microparticles obtained had a good appearance, a bulk density of 0.1 g/cm ³ and a yield of 90%, and no ash content was measured. Table 1 shows the compounding amounts used and the treatment conditions and results using the supercritical fluid.

<Example 2>
In Example 1, the solid obtained after centrifugation was slurried in 100 g of ethanol, filtered through a filter paper with a mesh size of 1 μm, and placed in a high-pressure container. The solid was slurried with 100 g of tert-butyl alcohol (TBA), degassed by freeze-drying, and then placed in a high-pressure vessel under the same conditions as in Example 1. It was confirmed by TG measurement that chlorobenzene had been removed from the obtained fine hollow particles, and the average particle size was 23 μm. The hollow microparticles obtained had a good appearance, a bulk density of 0.1 g/cm ³ and a yield of 90%, and no ash content was measured. Table 1 shows the compounding amounts used and the treatment conditions and results using the supercritical fluid.

<Examples 3 to 6>
Fine hollow particles were prepared and evaluated in the same manner as in Example 1 or 2, except that the blending amount shown in Table 1 and the conditions of supercritical carbon dioxide were used. Table 1 shows the results. The obtained hollow microparticles all had a bulk density of 0.1 g/cm ³ and a yield of 90%, and no ash content was measured.

<Comparative Example 1>
Using the compounding amounts shown in Table 1, preparation was performed in the same manner as in Example 1 up to the point of obtaining a solid by centrifugation, and the resulting solid was dried in an oven at 140°C for 48 hours to obtain fine hollow particles. Obtained. It was confirmed by TG measurement that chlorobenzene was removed from the obtained hollow microparticles. The average particle size was 19.5 µm. Many of the obtained hollow microparticles were broken in appearance, the bulk density of the obtained hollow microparticles was 0.15 g/cm ³ , the yield was 30%, and the ash content was not measured. Table 1 shows the results.

(CMP polishing pad)
(c) Component Pre-1: A urethane prepolymer having an iso(thio)cyanate equivalent of 460 and iso(thio)cyanate groups at both ends (method for producing Pre-1)
In a flask equipped with a nitrogen inlet tube, a thermometer and a stirrer, 1000 g of 2,4-tolylene diisocyanate and 1100 g of polypropylene glycol (number average molecular weight: 500) were reacted at 80° C. for 4 hours in a nitrogen atmosphere. Diethylene glycol: 120 g was added and reacted at 80° C. for 5 hours to obtain a terminal isocyanate urethane prepolymer (Pre-1) having an iso(thio)cyanate equivalent of 460.

(d) component DB-1; cyclic compound having 9 hydroxyl groups at the side chain end; (db) component (Method for producing DB-1)
10 g of hydroxypropylated β-cyclodextrin (CycloChem Co., Ltd.) and 32.0 g of ε-caprolactone were stirred at 130° C. while flowing dry nitrogen to form a uniform solution, and then tin (II) 2-ethylhexanoate was added to 0.04 g. was added and allowed to react for 16 hours to obtain the desired product, DB-1. The physical properties of DB-1 were as follows.
Weight average molecular weight Mw (GPC): 4800
Dispersion degree (GPC): 1.05
Modification degree of side chain: 0.43 (43% when displayed in %)
Side chain terminal polymerizable group: hydroxyl Number of side chains introduced into cyclic molecule: 9 Molecular weight of side chain: about 550 on average
Viscosity: 3,800mPa s

[Measuring method]
(3) Resin density:
The density (g/cm ³ ) was measured with (DSG-1) manufactured by Toyo Seiki.

(4) Shore D hardness:
Shore D hardness was measured with a durometer manufactured by Kobunshi Keiki Co., Ltd. according to JIS standard (hardness test) K6253. The thickness was measured so as to be 6 mm. Relatively low hardness was measured by Shore A hardness, and relatively high hardness was measured by Shore D hardness.

(5) Hysteresis loss: A resin punched into a dumbbell No. 8 shape with a thickness of 2 mm is stretched by 20 mm at 10 mm / min with an autograph of AG-SX manufactured by Shimadzu Corporation, and then hysteresis when returning until the stress becomes zero. loss was measured.

(6) Polishing rate:
The polishing rate was measured when polishing was carried out under the following conditions. The polishing rate is an average value for six 2-inch sapphire wafers.

CMP polishing pad: 300 mm diameter, 1 mm thick pad with concentric grooves formed on the surface Slurry: FUJIMI Compol 80 undiluted solution Pressure: 3.0 psi
Rotation speed: 45rpm
Time: 1 hour

(7) Scratches: The presence or absence of scratches on the wafers when polished under the conditions described in (6) above was checked. Evaluation was performed according to the following criteria.
1: No scratches on all 6 sheets with a laser microscope 2: Thin scratches can be confirmed with a laser microscope on only 1 sheet 3: Clear scratches can be confirmed with a laser microscope on only 1 sheet 4: 2 or more sheets with a laser microscope Scratches can be confirmed

<Example 7>
21 parts by mass of DB-1, which is the component (db) produced above, and 9 parts by mass of 4,4′-methylenebis(o-chloroaniline) (MOCA), which is the component (da), were mixed at 120° C. After making a homogeneous solution, it was fully degassed to prepare a liquid A. Separately, the fine hollow particles of Example 1: 4.5 parts by mass were added to Pre-1: 70 parts by mass of the component (c) produced above heated to 70 ° C., and the mixture was stirred with a rotation and revolution stirrer to obtain a uniform mixture. A solution B was prepared. Liquid A was added to liquid B prepared above and uniformly mixed to obtain a curable composition. The curable composition was injected into a mold, defoamed under a reduced pressure of 5 kPa for 2 minutes, and then cured at 100° C. for 15 hours. After curing, it was removed from the mold to obtain a cured body.

Next, the obtained cured product was sliced to prepare a cured product having a thickness of 1 mm, and the following various physical properties were measured. The obtained cured product had a density of 0.95 g/cm ³ , a Shore D hardness of 48D, and a hysteresis loss of 60%.

In addition, a spiral groove was formed on the surface of the 1 mm thick hardened body obtained by slicing, and a double-sided tape was attached to the back surface to form a polishing pad made of a hardened body with a size of 300 mmφ and a thickness of 1 mm.

The polishing rate of the polishing pad made of the cured product obtained above was 3.0 μm/hr, and the number of scratches was 1. Table 2 shows the results.

<Comparative Example 2>
A cured body was produced in the same manner except that 4.5 parts by mass of the hollow microparticles of Comparative Example 1 were used in place of the hollow microparticles of Example 1 used in Example 7, and the density of the resulting cured body was The hardness was 1.09 g/cm ³ , the Shore D hardness was 50D, and the hysteresis loss was 62%.

The polishing rate of the polishing pad prepared in the same manner as in Example 1 was 1.5 μm/hr, and the number of scratches was 2. Table 2 shows the results.

<Comparative Example 3>
Instead of the fine hollow particles of Example 1 used in Example 7, 0.8 of commercially available microcapsules 920-40 (manufactured by Nippon Philite Co., Ltd., hollow microballoons made of acrylonitrile resin with inorganic powder sprinkled on the surface) A cured body was produced in the same manner except that parts by mass were used, and the resulting cured body had a density of 0.85 g/cm ³ , a Shore D hardness of 44D, and a hysteresis loss of 69%.

The polishing rate of the polishing pad prepared in the same manner as in Example 1 was 1.9 μm/hr, and the number of scratches was 2. Table 2 shows the results.

Preferred embodiments of the present invention are added below.
[1]
Manufacture of fine hollow particles having a resin film containing at least one resin selected from the group consisting of melamine resin, urea resin, amide resin, and urethane (urea) resin, and a hollow portion surrounded by the resin film a method for
preparing an oil-in-water (O/W) emulsion in which an oil phase containing an organic solvent is a dispersed phase and an aqueous phase is a continuous phase to obtain microparticles in which the organic solvent is encapsulated;
removing the organic solvent from the interior of the microparticles using a supercritical fluid;
A method for producing hollow microparticles.
[2]
The manufacturing method according to [1], wherein the supercritical liquid is supercritical carbon dioxide.
[3]
The production method according to [1] or [2], wherein the pressure of the supercritical liquid is 10 MPa or more and 40 MPa or less.
[4]
The manufacturing method according to any one of [1] to [3], wherein the temperature inside the device using the supercritical liquid is 31.1°C or higher and 60°C or lower.
[5]
The manufacturing method according to any one of [1] to [4], wherein the flow rate of the supercritical liquid is 1 mL/min or more and 200 mL/min or less.
[6]
The manufacturing method according to any one of [1] to [5], wherein the contact time between the supercritical liquid and the microparticles is 10 minutes or more and 720 minutes or less.
[7]
after contacting the microparticles with a hydrophilic organic solvent, using the supercritical liquid to remove the organic solvent from the inside of the microparticles after the treatment with the hydrophilic organic solvent, [1] to The manufacturing method according to any one of [6].
[8]
The production method according to any one of [1] to [7], wherein the hollow microparticles have an average particle size measured by a scanning electron microscope of 1 μm or more and 100 μm or less.
[9]
A method for producing a curable composition, comprising mixing hollow microparticles obtained by the production method according to any one of [1] to [8] and a compound having an iso(thio)cyanate group.
[10]
A method for producing a cured body, comprising curing the curable composition obtained by the production method according to [9].
[11]
A method for producing hollow microparticles having a resin film containing a melamine-based resin and a hollow portion surrounded by the resin film,
preparing an oil phase comprising an organic solvent;
preparing an aqueous phase comprising a surfactant comprising a maleic anhydride copolymer;
mixing and stirring the oil phase and the water phase to prepare an oil-in-water (O/W) emulsion in which the water phase is the continuous phase and the oil phase is the dispersed phase;
A melamine-formaldehyde prepolymer compound is added to the oil-in-water (O/W) emulsion, and a condensation reaction of the melamine-formaldehyde prepolymer compound occurs on the interface of the oil-in-water (O/W) emulsion to generate the resin film. and obtaining a fine particle dispersion containing fine particles containing an organic solvent enclosed inside the resin film,
separating the microparticles from the microparticle dispersion; and
removing the organic solvent from the interior of the microparticles using supercritical carbon dioxide;
The method for producing hollow microparticles, wherein the amount of the aqueous phase is 100 parts by mass or more and 500 parts by mass or less when the oil phase is 100 parts by mass.
[12]
The manufacturing method according to [11], wherein the organic solvent has a boiling point of 100°C or higher and 180°C or lower.
[13]
a resin film containing at least one resin selected from the group consisting of melamine resins, urea resins, amide resins, and urethane (urea) resins; and a hollow portion surrounded by the resin film,
An oil-in-water (O/W) emulsion in which an oil phase containing an organic solvent is a dispersed phase and an aqueous phase is a continuous phase is prepared, and after obtaining microparticles in which the organic solvent is encapsulated, a supercritical liquid is obtained. obtained by removing the organic solvent from the inside of the microparticles,
micro hollow particles.
[14]
A resin composition comprising the hollow microparticles of [13] and a polyurethane resin.
[15]
A CMP polishing pad comprising the resin composition according to [14].

Claims

Manufacture of fine hollow particles having a resin film containing at least one resin selected from the group consisting of melamine resin, urea resin, amide resin, and urethane (urea) resin, and a hollow portion surrounded by the resin film a method for
preparing an oil-in-water (O/W) emulsion in which an oil phase containing an organic solvent is a dispersed phase and an aqueous phase is a continuous phase to obtain microparticles in which the organic solvent is encapsulated;
removing the organic solvent from the interior of the microparticles using a supercritical fluid;
A method for producing hollow microparticles.
The manufacturing method according to claim 1, wherein the supercritical liquid is supercritical carbon dioxide.
The manufacturing method according to claim 1, wherein the pressure of the supercritical liquid is 10 MPa or more and 40 MPa or less.
The manufacturing method according to claim 1, wherein the temperature inside the device using the supercritical liquid is 31.1°C or higher and 60°C or lower.
The manufacturing method according to claim 1, wherein the supercritical fluid has a flow rate of 1 mL/min or more and 200 mL/min or less.
The manufacturing method according to claim 1, wherein the contact time between the supercritical liquid and the microparticles is 10 minutes or more and 720 minutes or less.
2. The method according to claim 1, comprising removing the organic solvent from inside the microparticles after the treatment with the hydrophilic organic solvent using the supercritical liquid after contacting the microparticles with the hydrophilic organic solvent. Method of manufacture as described.
The manufacturing method according to claim 1, wherein the average particle diameter of the fine hollow particles measured by a scanning electron microscope is 1 µm or more and 100 µm or less.
A method for producing a curable composition, comprising mixing the hollow microparticles obtained by the production method according to claim 1 and a compound having an iso(thio)cyanate group.
A method for producing a cured body, comprising curing the curable composition obtained by the production method according to claim 9.
A method for producing hollow microparticles having a resin film containing a melamine-based resin and a hollow portion surrounded by the resin film,
preparing an oil phase comprising an organic solvent;
preparing an aqueous phase comprising a surfactant comprising a maleic anhydride copolymer;
mixing and stirring the oil phase and the water phase to prepare an oil-in-water (O/W) emulsion in which the water phase is the continuous phase and the oil phase is the dispersed phase;
A melamine-formaldehyde prepolymer compound is added to the oil-in-water (O/W) emulsion, and a condensation reaction of the melamine-formaldehyde prepolymer compound occurs on the interface of the oil-in-water (O/W) emulsion to generate the resin film. and obtaining a fine particle dispersion containing fine particles containing an organic solvent enclosed inside the resin film,
separating the microparticles from the microparticle dispersion; and
removing the organic solvent from the interior of the microparticles using supercritical carbon dioxide;
The method for producing hollow microparticles, wherein the amount of the aqueous phase is 100 parts by mass or more and 500 parts by mass or less when the oil phase is 100 parts by mass.
The production method according to claim 11, wherein the organic solvent has a boiling point of 100°C or higher and 180°C or lower.
a resin film containing at least one resin selected from the group consisting of melamine resins, urea resins, amide resins, and urethane (urea) resins; and a hollow portion surrounded by the resin film,
An oil-in-water (O/W) emulsion in which an oil phase containing an organic solvent is a dispersed phase and an aqueous phase is a continuous phase is prepared, and after obtaining microparticles in which the organic solvent is encapsulated, a supercritical liquid is obtained. obtained by removing the organic solvent from the inside of the microparticles,
micro hollow particles.
A resin composition comprising the hollow microparticles according to claim 13 and a polyurethane resin.
A CMP polishing pad comprising the resin composition according to claim 14 .