JP7270330B2 - POLYURETHANE RESIN FOAM AND METHOD FOR MANUFACTURING POLYURETHANE RESIN FOAM - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polymeric body, a polishing pad, and a method for producing a polymeric body.

Polymers containing polyurethane resins are used in various applications.
For example, such a polymer is used as a polishing pad or the like for polishing an object to be polished (eg, silicon wafer, etc.) (eg, Patent Document 1, etc.).

JP 2015-6729 A

Examples of methods for polishing an object to be polished using the polishing pad include the following methods.
First, a disk-shaped object to be polished is attached to the lower surface of the upper surface plate of the polishing machine, and a disk-shaped polishing pad is attached to the upper surface of the lower surface plate of the polishing machine. Then, the object to be polished is pressed against the polishing pad by the upper surface plate and the lower surface plate. Next, with the object to be polished pressed against the polishing pad, the object to be polished is polished by rotating the upper surface plate and the lower surface plate while supplying polishing slurry onto the polishing pad. do.
As the polishing slurry, a polishing slurry or the like containing water and abrasive grains is used.

By the way, when polishing an object to be polished, if the polishing pad is hard, the object to be polished is likely to be damaged.
In recent years, there has been a demand for a polishing method that does not easily cause scratches on the object to be polished.

However, polishing pads with low hardness have the problem of lacking handleability.
For example, a disk-shaped polishing pad usually has a diameter of about 1000 to 2500 mm. If a polishing pad of such a size is too soft, it is likely to be deformed during transportation, and as a result, the polishing pad is polished from outside the polishing machine. There is a problem that it is difficult to carry the substrate to a predetermined position on the surface plate of the machine.
Also, the method of attaching the polishing pad to the surface plate is usually the following method. That is, the polishing pad is attached to the surface plate by attaching one surface of the double-sided tape to the polishing pad and then attaching the other surface of the double-sided tape attached to the polishing pad to the surface plate. However, if the polishing pad is too soft, the handleability is low, so there is also the problem that the other side of the double-sided tape stuck to the polishing pad sticks to the surface plate at a position shifted from the desired position.

In general, a polishing pad is produced by first producing a polymer larger than the desired size of the polishing pad, and then slicing the polymer to produce a polishing pad. However, there is a problem that if the polymer is too soft, it will be difficult to slice.

Focusing on such problems, the present inventor conducted extensive studies and found that a polishing pad with a low hardness is required for polishing an object to be polished, and a polishing pad with a high hardness is required for other purposes. I found that when

That is, as a result of extensive studies, the inventors of the present invention have found that a polymer suitable for polishing pads and the like can be provided by providing a polymer whose hardness is reduced under specific circumstances.

Therefore, in view of the above-mentioned needs, the present invention provides a polymer whose hardness is reduced under specific circumstances, a polishing pad comprising the polymer, and a polymer for producing the polymer. An object of the present invention is to provide a method for producing the

The polymer according to the present invention is a polymer containing a polyurethane resin,
The polyurethane resin comprises a first structural unit derived from a compound containing active hydrogen and a second structural unit derived from a compound containing an isocyanate group, and the first structural unit is derived from polyethylene glycol. It comprises a structural unit and a structural unit derived from an amine compound.

Polyurethane resins related to such polymers tend to contain a large number of ether bonds by having structural units derived from polyethylene glycol, that is, they tend to increase polarity. As a result, this polyurethane resin has a chemical structure with excellent affinity with liquid polar substances (such as water). Therefore, when this polyurethane resin comes into contact with a liquid polar substance, polar molecules (such as H ₂ O molecules) easily enter between polymer molecules of the polyurethane resin. As a result, this polyurethane resin has a lower hardness when it is in contact with the liquid polar substance than when it is not in contact with the liquid polar substance.
Therefore, such a polymer has a lower hardness when it is in contact with a liquid polar substance than when it is not in contact with a liquid polar substance.
That is, such a polymer is a polymer whose hardness is lowered under certain circumstances.

Further, in the polymer according to the present invention, preferably, the polyurethane resin includes a polyethylene glycol-derived structural unit represented by the following formula (1) as the polyethylene glycol-derived structural unit.

Furthermore, in the polymer according to the present invention, preferably, the polyurethane resin includes a structural unit derived from 4,4′-methylenebis(2-chloroaniline) as the structural unit derived from the amine compound, and a tri At least one of structural units derived from ethanolamine is provided.

Moreover, in the polymer according to the present invention, the polyurethane resin preferably has a crosslinked structure.

Since the polyurethane resin has a crosslinked structure, such a polymer can suppress expansion by the liquid polar substance (such as water) when it comes into contact with the liquid polar substance. It has the advantage of being able to suppress deformation due to contact with a liquid polar substance.

Furthermore, the polymer according to the present invention is preferably a polyurethane resin foam containing the polyurethane resin.

Moreover, the polymer according to the present invention is preferably used for a polishing pad, and is used as a portion constituting at least the polishing surface of the polishing pad.

Further, a polishing pad according to the present invention comprises the polymer body.

Furthermore, a method for producing a polymer according to the present invention is a method for producing a polymer containing a polyurethane resin, comprising:
The polyurethane resin is obtained by combining an amine compound containing active hydrogen, polyethylene glycol, and a compound containing an isocyanate group.

Moreover, in the method for producing a polymer according to the present invention, the compound containing an isocyanate group is preferably a prepolymer.

As described above, according to the present invention, there is provided a polymer whose hardness is reduced under specific conditions, a polishing pad comprising the polymer, and a polymer for producing the polymer. A manufacturing method may be provided.

1 is a SEM photograph of a cross section of the polymer of Example 1. FIG. SEM photograph of a cross section of the polymer of Example 7. FIG. SEM photograph of a cross section of the polymer of Example 13. FIG. SEM photograph of a cross section of the polymer of Example 10. FIG.

An embodiment of the invention will be described below.

First, the polymer according to the present embodiment will be described with a polishing pad polymer used for a polishing pad as an example.

The polymer according to this embodiment is used as a portion constituting at least the polishing surface of the polishing pad.

The polymer according to this embodiment is a polymer containing a polyurethane resin. Specifically, the polymer according to this embodiment is a polyurethane resin foam containing a polyurethane resin.

The polyurethane resin is derived from a first structural unit derived from a compound containing active hydrogen (hereinafter also referred to as an "active hydrogen compound") and a compound containing an isocyanate group (hereinafter also referred to as an "isocyanate compound"). and a second structural unit.
Further, the polyurethane resin includes, as the first structural units, a structural unit derived from polyethylene glycol and a structural unit derived from an amine compound.
Further, the polyurethane resin is a resin obtained by combining a polyol, which is an active hydrogen compound, and a polyisocyanate, which is an isocyanate compound.
The polyurethane resin has a structure in which an active hydrogen compound and an isocyanate compound are urethane-bonded to alternately repeat first structural units derived from the active hydrogen compound and second structural units derived from the isocyanate compound. It's becoming

The polyethylene glycol is a polyol and represented by the following formula (1). Here, n is an integer of 2 or more. The concept of polyethylene glycol also includes diethylene glycol. Diethylene glycol is represented by the following formula (2).

In the polyurethane resin, as a structural unit derived from polyethylene glycol, n in the above formula (1) is preferably an integer of 2 or more and 20 or less, more preferably an integer of 4 or more and 10 or less. Have units.

Moreover, it is preferable that the polyurethane resin includes a structural unit derived from diethylene glycol as the structural unit derived from polyethylene glycol.

The polymer according to the present embodiment preferably contains 5 to 18% by mass of polyethylene glycol contained in the constituent units of the polyurethane resin when the polyurethane resin is 100% by mass.
When the polyurethane resin is 100% by mass, the polymer according to the present embodiment contains 5% by mass or more of polyethylene glycol, which is a constituent unit of the polyurethane resin, so that a liquid polar substance (such as water ) has the advantage that the hardness tends to decrease when it comes into contact with.
Further, the polymer according to the present embodiment contains 18% by mass or less of polyethylene glycol contained in the constituent units of the polyurethane resin when the polyurethane resin is 100% by mass. It has the advantage of being hard in the non-contact state.
The content ratio of polyethylene glycol contained in the constituent units of the polyurethane resin can be obtained as follows when the polyurethane resin is 100% by mass.
First, a polymer is dissolved in a polar solvent (heavy DMF, heavy DMSO, etc.) to obtain a dissolved substance. Next, the dissolved product is analyzed by 1H-NMR to quantify polyethylene glycol and determine the content of polyethylene glycol.
Another method for determining the content ratio of the polyethylene glycol is as follows.
First, a polymer is chemically decomposed with methanol to obtain a decomposition product. Next, the decomposition product is fractionated by gel permeation chromatography (GPC) or the like, and each fraction is analyzed by 1H-NMR or GC-MS to quantify polyethylene glycol, and the content ratio of polyethylene glycol Ask for

In the polymer according to this embodiment, the polyurethane resin includes a structural unit derived from an amine compound as the first structural unit.
In the polymer according to the present embodiment, the polyurethane resin has a constitutional unit derived from an amine compound, so that the backbone of the polyurethane molecule contains a nitrogen atom. Nitrogen atoms have high electronegativity. Therefore, the polymer contains nitrogen atoms in the skeleton of the polyurethane molecule, and polarization occurs between atoms in the polyurethane molecule in the polymer. The polymer has a high cohesive force between main chains due to electrostatic interaction (for example, hydrogen bonding) between polarized atoms. As a result, such a polymer has high hardness.

The amine compound contains active hydrogen. Examples of the amine compound include primary amines, secondary amines, and tertiary amines. In the amine compound, the active hydrogen may be directly bonded to nitrogen, or may be bonded via another element. Examples of the functional group having active hydrogen in the amine compound include —NH ₂ and a hydroxy group.
The amine compound may have one or more of the functional groups. The amine compound preferably has two or more functional groups.

Examples of the amine compounds include 4,4′-methylenebis(2-chloroaniline) (MOCA), triethanolamine, 4,4′-methylenedianiline, trimethylenebis(4-aminobenzoate), 2-methyl 4, 6-bis(methylthio)benzene-1,3-diamine, 2-methyl 4,6-bis(methylthio)-1,5-benzenediamine and the like.
4,4′-Methylenebis(2-chloroaniline) (MOCA) is represented by the following formula (3), and triethanolamine is represented by the following formula (4).

In the polyurethane resin, as structural units derived from the amine compound, at least one of structural units derived from 4,4'-methylenebis(2-chloroaniline) (MOCA) and structural units derived from triethanolamine. Preferably one is provided.
By having such a structure, the polyurethane resin has an advantage that the hardness of the polymer body can be easily made suitable for the polishing pad.
Moreover, MOCA and triethanolamine have the advantage that when used as a curing agent, the reaction rate with the main agent is a rate suitable for molding a polyurethane resin. In addition, MOCA and triethanolamine have the advantage that when used as a curing agent, they have a low viscosity when melted and are easy to handle when producing a polyurethane resin.

In the polyurethane resin, as structural units derived from the amine compound, a structural unit derived from 4,4′-methylenebis(2-chloroaniline) (MOCA), 2-methyl 4,6-bis(methylthio)benzene-1 ,3-diamine and 2-methyl-4,6-bis(methylthio)-1,5-benzenediamine.
By having such a structure, the polyurethane resin has a benzene ring, and as a result, has the advantage of high hardness.

Examples of the polyethylene glycol and the polyol other than the triethanolamine include a polyol monomer and a polyol polymer.

Examples of the polyol monomer include 1,4-benzenedimethanol, 1,4-bis(2-hydroxyethoxy)benzene, ethylene glycol, propylene glycol 1,3-propanediol, 1,3-butanediol, 1, linear aliphatic glycols such as 5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol; neopentyl glycol; , 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, etc. Branched aliphatic glycols include alicyclic diols such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, glycerin, trimethylolpropane, tributyropropane, pentaerythritol. , and polyfunctional polyols such as sorbitol.

As the polyol monomer, ethylene glycol and diethylene glycol are preferable because they tend to increase the strength during reaction, tend to increase the rigidity of the polishing pad containing the produced polyurethane foam, and are relatively inexpensive.

Examples of the polyol polymer include polyether polyol, polyester polyol, polyester polycarbonate polyol, and polycarbonate polyol. The polyol polymer may also include a polyfunctional polyol polymer having 3 or more hydroxyl groups in the molecule.

Specifically, the polyether polyol includes polytetramethylene ether glycol (PTMG), polypropylene glycol (PPG), ethylene oxide-added polypropylene polyol, and the like.

Examples of the polyester polyol include polyethylene adipate glycol, polybutylene adipate glycol, polycaprolactone polyol, and polyhexamethylene adipate glycol.

Examples of the polyester polycarbonate polyol include a reaction product of a polyester glycol such as polycaprolactone polyol and an alkylene carbonate, and a reaction mixture obtained by reacting ethylene carbonate with a polyhydric alcohol is further reacted with an organic dicarboxylic acid. reaction products obtained by

The polycarbonate polyols include diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, or polytetramethylene ether glycol, phosgene, and diallyl carbonate. (eg diphenyl carbonate) or reaction products with cyclic carbonates (eg propylene carbonate).

The polyol polymer preferably has a number-average molecular weight of 800 to 8000 in that elastic foamed polyurethane can be easily obtained. Specifically, polytetramethylene ether glycol (PTMG) and ethylene oxide-added polypropylene are preferred. Polyols are preferred.
In addition, in this-application specification, a number average molecular weight means the value measured by GPC (gel permeation chromatography).

In addition, dipropylene glycol, tripropylene glycol and the like are also mentioned as the polyol.

Examples of the polyisocyanate include polyisocyanate and polyisocyanate prepolymer.

Examples of the polyisocyanate include aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate.

Examples of the aromatic diisocyanate include tolylene diisocyanate (TDI), 1,5-naphthalene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, and 1,4-phenylene diisocyanate. Examples of the aromatic diisocyanate include diphenylmethane diisocyanate (MDI) and modified diphenylmethane diisocyanate (MDI).

Modified products of diphenylmethane diisocyanate (MDI) include, for example, carbodiimide modified products, urethane modified products, allophanate modified products, urea modified products, biuret modified products, isocyanurate modified products, oxazolidone modified products and the like. Specific examples of such modified products include carbodiimide-modified diphenylmethane diisocyanate (carbodiimide-modified MDI).

Examples of the aliphatic diisocyanate include ethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and hexamethylene diisocyanate (HDI).

Examples of the alicyclic diisocyanate include 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, norbornane diisocyanate, and methylenebis(4,1-cyclohexylene)=diisocyanate.

Examples of the polyisocyanate prepolymers include prepolymers in which a polyol is combined with at least one of an aromatic diisocyanate, an aliphatic diisocyanate, and an alicyclic diisocyanate.

The polyurethane resin preferably has a crosslinked structure.
The polyurethane resin has at least one functional group of a functional group having an active hydrogen and an isocyanate group, and a structural unit derived from a polyfunctional compound having a total of three or more functional groups having an active hydrogen and isocyanate groups. is preferably provided.
The polyfunctional compound contained in the constituent units of the polyurethane resin has surplus functional groups in addition to the functional groups bonded to the main chain. The excess functional groups form a structure in which the first structural units derived from the active hydrogen compound and the second structural units derived from the isocyanate compound are alternately repeated in the polyurethane resin. Thereby, the polyurethane resin has a crosslinked structure.
Examples of the polyfunctional compound include compounds represented by the following formula (5). Here, “R” in “the following formula (5)” includes “(C _n H _2n )” (where n is a positive integer, eg n=1 to 10).
Examples of the compound of the following formula (5) include an isocyanurate form of 1,6-hexamethylene diisocyanate (R=C ₆ H ₁₂ ).

The cross-linking concentration in the polyurethane resin is preferably 0.06 to 0.80 mmol/g.
The cross-linking concentration is the amount of cross-linking points in 1 g of the polyurethane resin expressed in mole units.

The polymer according to this embodiment may contain cerium oxide.
By containing cerium oxide, the polymer according to this embodiment has the following advantages.
That is, the polymer according to this embodiment has the advantage of being able to improve the cut rate of the polishing pad. In addition, the polymer according to the present embodiment has an advantage that the object to be polished is less likely to be scratched. Furthermore, the polymer according to this embodiment has the advantage of being able to increase the polishing rate.

The apparent density of the polyurethane resin foam is preferably 0.4-0.7 g/cm ³ .
In addition, the apparent density can be measured based on JIS K7222:2005.

The polymer according to this embodiment is configured as described above. Next, a method for producing the polymer according to this embodiment will be described.

In the method for producing a polymer according to this embodiment, a polymer containing a polyurethane resin is obtained.
Further, in the method for producing a polymer according to the present embodiment, the polyurethane resin is obtained by combining an amine compound containing active hydrogen, polyethylene glycol, and a compound containing an isocyanate group.
Specifically, in the method for producing a polymer according to the present embodiment, an amine compound containing active hydrogen, polyethylene glycol, a compound containing an isocyanate group, and a blowing agent are mixed to obtain a mixture, and the mixture is is polymerized and foamed to obtain a polymer.

In the method for producing a polymer according to this embodiment, it is preferable that the compound containing an isocyanate group is a prepolymer.
In other words, in the method for producing a polymer according to the present embodiment, the polymer is produced by reacting a prepolymer containing two or more isocyanate groups with the polyethylene glycol and the amine compound as curing agents. It is preferable to obtain
In the method for producing such a polymer, the polyethylene glycol and the amine compound are used as curing agents to adjust the blending ratio of the polyethylene glycol and the amine compound to give the polymer a desired hardness. It has the advantage of being easy to make.

In the method for producing a polymer according to the present embodiment, the amount of polyethylene glycol as a curing agent is preferably 3 to 20 parts by mass, more preferably 5 to 13 parts by mass, based on 100 parts by mass of the prepolymer.
The weight average molecular weight of polyethylene glycol as the curing agent is preferably 200-8000, more preferably 400-4000.
In addition, in this-application specification, a mass average molecular weight means the value measured by GPC (gel permeation chromatography).
The larger the weight average molecular weight (the larger n in the above formula (1)), the more difficult it is for polyethylene glycol to absorb moisture. When the isocyanate group reacts with water, carbon dioxide is generated. However, polyethylene glycol is less likely to absorb moisture, so it is possible to suppress the reaction between the isocyanate group of the main agent and water, thereby suppressing unintended foaming of the polyurethane resin due to carbon dioxide. can. As a result, it becomes easier to adjust the polymer to a desired apparent density.
Also, the higher the weight average molecular weight (the larger n in the above formula (1)), the higher the boiling point of polyethylene glycol. When the polyethylene glycol and the main agent are reacted, the polyethylene glycol and the main agent are heated, and the evaporation of the polyethylene glycol due to this heating can be suppressed.
On the other hand, the smaller the weight average molecular weight (the smaller n in the above formula (1)), the higher the reaction rate between polyethylene glycol and the main agent.
In addition, the smaller the weight average molecular weight (the smaller n in the above formula (1)), the lower the viscosity of polyethylene glycol. As a result, polyethylene glycol becomes easier to handle when producing a polymer.

In addition, in the method for producing a polymer according to the present embodiment, the amine compound as the curing agent is preferably 30 to 300 parts by mass, more preferably 50 to 150 parts by mass with respect to 100 parts by mass of polyethylene glycol as the curing agent. Department.

Examples of the prepolymer include tolylene diisocyanate (TDI), polytetramethylene ether glycol (PTMG), and a prepolymer obtained by reacting diethylene glycol (DEG), tolylene diisocyanate (TDI), and polypropylene glycol (PPG). ), and a prepolymer obtained by reacting diethylene glycol (DEG).

The foaming agent is not particularly limited as long as it generates gas to form air bubbles when the foamed polyurethane is molded, and forms air bubbles in the foamed polyurethane. Organic chemical foaming agents that generate gas by heating, low-boiling hydrocarbons having a boiling point of -5 to 70°C, halogenated hydrocarbons, water, liquefied carbon dioxide gas, etc. can be used alone or in combination.

Examples of the organic chemical foaming agent include azo compounds (azodicarbonamide, azobisisobutyronitrile, diazoaminobenzene, barium azodicarboxylate, etc.), nitroso compounds (N,N'-dinitrosopentamethylenetetramine, N,N'-dinitroso-N,N'-dimethylterephthalamide, etc.), sulfonylhydrazide compounds [p,p'-oxybis(benzenesulfonylhydrazide), p-toluenesulfonylhydrazide, etc.] and the like.
Examples of the low boiling point hydrocarbons include butane, pentane, cyclopentane, and mixtures thereof.
Examples of the halogenated hydrocarbons include methylene chloride and HFCs (hydrofluorocarbons).

Moreover, the foaming agent may be a heat-expandable spherical body. The particle size of the heat-expandable spheres is, for example, 2 to 100 μm. The heat-expandable spherical body comprises a hollow body made of a thermoplastic resin and a liquid hydrocarbon provided in the hollow part of the hollow body. Examples of the heat-expandable spherical bodies include Expancel (registered trademark) manufactured by Nippon Philite Co., Ltd., and heat-expandable microcapsules (trade name: Matsumoto Microsphere (registered trademark) manufactured by Matsumoto Yushi Seiyaku Co., Ltd.). .

The mixture may contain a compound of formula (6) below. By containing the compound of the following formula (6), the mixture tends to have a low viscosity, and as a result, there is an advantage that it is easy to obtain a polymer having a desired shape from the mixture. Moreover, the mixture has the advantage that the polarity of the polymer can be increased by containing the compound of the following formula (6).
Note that "n" in the following formula (6) is an integer of 1 or more.

The polishing pad according to this embodiment includes the polymer body according to this embodiment.

The polymer, polishing pad, and method for producing the polymer according to the present invention are not limited to the above embodiments. Moreover, the polymer, the polishing pad, and the method for producing the polymer according to the present invention are not limited to the effects described above. Various modifications can be made to the polymer, the polishing pad, and the method for producing the polymer according to the present invention without departing from the gist of the present invention.

That is, the polymer according to the present embodiment is formed by adding a foaming agent to the mixture, but may be formed by mixing air into the mixture by stirring.

Moreover, although the polymer according to the present embodiment is a polyurethane resin foam, the polymer according to the present invention may be a polymer obtained by impregnating a non-woven fabric with a polyurethane resin.
Furthermore, the high-molecular weight polyurethane resin according to the present invention may be formed by incorporating hollow microbodies into the mixture.

Moreover, although the polymer according to the present embodiment is a polymer for polishing pads, the polymer according to the present invention may be used for other applications, such as cosmetic materials and office use. It may be used as a sponge, a cleaning sponge, a filler for resin modification, and the like.

EXAMPLES Next, the present invention will be described more specifically with reference to examples and comparative examples.

The following materials were used.
<Main agent>
・Main agent 1: Urethane prepolymer obtained by reacting tolylene diisocyanate (TDI), polytetramethylene ether glycol (PTMG), and diethylene glycol (DEG) (urethane prepolymer having isocyanate as a terminal group) (NCO% : 9.5%)
- Main agent 2: urethane prepolymer obtained by reacting tolylene diisocyanate (TDI), polypropylene glycol (PPG), and diethylene glycol (DEG) (urethane prepolymer having isocyanate as a terminal group) (NCO%: 8. 0%)
- Main agent 3: a compound of the following formula (5) (R=C ₆ H ₁₂ )
- Main agent 4: urethane prepolymer obtained by reacting tolylene diisocyanate (TDI) and polytetramethylene ether glycol (PTMG) (urethane prepolymer having isocyanate as a terminal group) (NCO%: 8.00)

＜硬化剤＞
・ＰＥＧ－１：ポリエチレングリコール（質量平均分子量：２００）
・ＰＥＧ－２：ポリエチレングリコール（質量平均分子量：６００）
・ＰＥＧ－３：ポリエチレングリコール（質量平均分子量：３１００）
・ＤＥＧ：ジエチレングリコール
・ＭＯＣＡ：４，４’－メチレンビス（２－クロロアニリン）
・ＴＥＯＡ：トリエタノールアミン

<Curing agent>
· PEG-1: polyethylene glycol (mass average molecular weight: 200)
· PEG-2: polyethylene glycol (mass average molecular weight: 600)
· PEG-3: polyethylene glycol (mass average molecular weight: 3100)
・DEG: diethylene glycol ・MOCA: 4,4′-methylenebis(2-chloroaniline)
・TEOA: Triethanolamine

<Additive>
・Blowing agent: heat-expandable spherical foaming agent (shell: thermoplastic polymer, inside: hydrocarbon)
・Cerium oxide: powdery cerium oxide ・Compound of the following formula (6)

(Example 1)
The main agent and additives shown in Table 1 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 60 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 2)
The main agent and additives shown in Table 2 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 40 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 3)
The main agent and additives shown in Table 3 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 70 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 4)
The main agent and additives shown in Table 4 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 60 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 5)
The main agent and additives shown in Table 5 below were mixed after reaching the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 90 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 6)
The main agent and additives shown in Table 6 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 120 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 7)
The main agent and additives shown in Table 7 below were mixed after reaching the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 70 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 8)
The main agent and additives shown in Table 8 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 90 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 9)
The main agent and additives shown in Table 9 below were mixed after reaching the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 100 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 10)
The main agent and additives shown in Table 10 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 60 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 11)
The main agent and additives shown in Table 11 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 90 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 12)
The main agent and additives shown in Table 12 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 90 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 13)
The main agent and additive shown in Table 13 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 80 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 14)
The main agent and additives shown in Table 14 below were mixed after reaching the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 120 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Comparative example 1)
The main agent and additives shown in Table 15 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 120 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 15)
The main agent and additives shown in Table 16 below were mixed at the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 120 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(Example 16)
The main agent and additives shown in Table 17 below were mixed after reaching the temperature shown in this table to obtain a first mixture.
Next, the curing agent shown in this table was brought to the temperature shown in this table, then mixed into the first mixture and allowed to stir for 120 seconds to obtain a second mixture. The mixing ratio of each material in the second mixture was the ratio shown in this table.
Then, the second mixture was heated at 100° C. for 10 hours to polymerize and foam, thereby obtaining a polymer.

(apparent density)
Apparent density was determined by the method described above.

(Hardness (JIS-A))
The hardness (JIS-A) was measured according to JIS K7312-1996 Type A hardness test.
The hardness at the time of drying was measured at 23°C. The wet hardness was measured at 23°C after immersing the polymer in hot water at 40°C for 24 hours.
Then, "amount of change in hardness" represented by the following formula was calculated.
Hardness change = dry hardness - wet hardness

(Bubble size)
In order to confirm the size of the air bubbles, the cross sections of the polymers of Examples 1, 7, 13 and 10 were photographed with a scanning electron microscope (SEM).

SEM photographs of Examples 1, 7, 13 and 10 are shown in FIGS. 1 to 4, respectively. Other results are shown in Table 18 below. In addition, the content ratio of polyethylene glycol contained in the structural units of the polyurethane resin (hereinafter also simply referred to as "PEG content ratio") when the polyurethane resin is 100% by mass in each polymer is also shown below. Table 18 shows.

As shown in Table 18, the hardness of the polymers of Examples 1 to 14 was significantly reduced by contact with water compared to the polymer of Comparative Example 1. Therefore, according to the present invention, it can be seen that the polymer has a lower hardness under specific circumstances.

As shown in FIGS. 1 to 4, the polymers of Examples 1, 7, and 13 having apparent densities of 0.4 to 0.7 g/cm ³ were found to have apparent densities of 0.36 g/cm ³ . Air bubbles were smaller than that of No. 10 polymer.
Therefore, by setting the apparent density of the polymer as the foam within the range of 0.4 to 0.7 g/cm ³ , the cell diameter can be reduced, and as a result, the polishing rate can be improved. Recognize.
In addition, the polymer bodies of Examples 1 to 14 exhibited higher values of hardness when dry compared to Examples 15 and 16, in which the content of PEG was high.

Claims (8)

A polyurethane resin foam containing a polyurethane resin ,
The polyurethane resin comprises a first structural unit derived from a compound containing active hydrogen and a second structural unit derived from a compound containing an isocyanate group, and the first structural unit is derived from polyethylene glycol. comprising a structural unit and a structural unit derived from an amine compound,
A polyurethane resin foam, wherein the content of polyethylene glycol contained in the constituent units of the polyurethane resin is 8.1 to 18% by mass when the polyurethane resin is 100% by mass . The polyurethane resin foam according to claim 1, wherein the polyurethane resin comprises a polyethylene glycol-derived structural unit represented by the following formula (1) as the polyethylene glycol- derived structural unit.

The polyurethane resin comprises at least one of structural units derived from 4,4′-methylenebis(2-chloroaniline) and structural units derived from triethanolamine as structural units derived from the amine compound. , The polyurethane resin foam according to claim 1 or 2. The polyurethane resin foam according to any one of claims 1 to 3, wherein the polyurethane resin has a crosslinked structure. The polyurethane resin foam according to any one of claims 1 to 4, which is a polyurethane resin foam containing the polyurethane resin . The polyurethane resin foam according to any one of claims 1 to 5, which is for a polishing pad and used as a portion constituting at least a polishing surface of the polishing pad. A polishing pad comprising the polyurethane resin foam of claim 6 . A method for producing a polyurethane resin foam containing a polyurethane resin, comprising:
obtaining the polyurethane resin by combining an amine compound containing active hydrogen, polyethylene glycol, and a compound containing an isocyanate group;
When the polyurethane resin is 100% by mass, the content of polyethylene glycol contained in the structural unit of the polyurethane resin is 8.1 to 18% by mass,
The compound containing the isocyanate group is a prepolymer,
A method for producing a polyurethane resin foam, wherein the blending amount of polyethylene glycol is 3 to 20 parts by mass with respect to 100 parts by mass of the prepolymer.

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