WO2017138564A1 - Polymer body, polishing pad, and method for producing polymer body - Google Patents

Abstract

The present invention is a polymer body or the like containing a polyurethane resin that is provided with first constituent units derived from a compound containing a hydroxyl group, and with second constituent units derived from a compound containing an isocyanate group, one or more of the first constituent units being derived from an organic cation containing a hydroxyl group and/or from an organic anion containing a hydroxyl group.

Description

Polymer, polishing pad, and method for producing polymer Cross-reference of related applications

This application claims the priority of Japanese Patent Application No. 2016-024739, and is incorporated herein by reference.

The present invention relates to a polymer, a polishing pad, and a method for producing the polymer.

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

Japanese Unexamined Patent Publication No. 2015-6729

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

By the way, if the polishing pad is hard when polishing the object to be polished, the object to be polished is likely to be damaged.
In recent years, a polishing method in which an object to be polished is less likely to be scratched may be required, and accordingly, a polishing pad with low hardness may be required.

However, a polishing pad with low hardness has a problem that it lacks handleability.
For example, a disc-shaped polishing pad usually has a diameter of about 1000 to 2500 mm. However, if the polishing pad of such a size is too soft, it is easily deformed when transported. As a result, the polishing pad is polished from outside the polishing machine. There is a problem that it is difficult to carry to a predetermined position on the surface plate of the machine.
Moreover, the method of sticking 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 side of the double-sided tape to the polishing pad and then attaching the other surface side of the double-sided tape attached to the polishing pad to the surface plate. However, if the polishing pad is too soft, the handling property is low, so there is also a problem that the other surface side of the double-sided tape attached to the polishing pad sticks to the surface plate at a position shifted from a desired position.

In addition, the polishing pad is usually prepared by temporarily producing a polymer body larger than a desired size as a polishing pad, and then slicing the polymer body to prepare the polishing pad. However, the polymer body has a problem that it is difficult to slice if it is too soft.

Focusing on such problems, the present inventor has diligently studied. A polishing pad having a low hardness is desired when polishing an object to be polished, and a polishing pad having a high hardness is otherwise required. I found out that

That is, as a result of intensive studies by the present inventors, it was found that a polymer suitable for a polishing pad or the like can be provided by providing a polymer having a low hardness under a specific situation.

Therefore, in view of the above-mentioned demands, the present invention provides a polymer body having low hardness under a specific situation, a polishing pad provided with the polymer body, and a polymer body for producing the polymer body It is an object to provide a manufacturing method.

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 a hydroxy group and a second structural unit derived from a compound containing an isocyanate group,
One or more of the first structural units are derived from at least one of an organic cation containing a hydroxy group and an organic anion containing a hydroxy group.

In the polymer according to the present invention, preferably, at least one of the first structural units is derived from an organic cation containing a hydroxy group.
Furthermore, the structural unit derived from the organic cation is preferably derived from an ionic liquid.

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

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

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

Moreover, the polishing pad according to the present invention includes the polymer.

Furthermore, the method for producing a polymer according to the present invention is a method for producing a polymer that obtains a polymer containing a polyurethane resin,
The polymer is obtained by bonding a compound containing a hydroxy group and a compound containing an isocyanate group,
The compound containing a hydroxy group has at least one of an organic cation containing a hydroxy group and an organic anion containing a hydroxy group.

In the polymer production method according to the present invention, preferably, the compound containing a hydroxy group has an organic cation containing a hydroxy group,
The organic cation is derived from an ionic liquid;
The bonding is performed at a temperature equal to or higher than the melting point of the ionic liquid.

4 is an SEM photograph of a cross section of the polymer body of Example 2. FIG. 4 is an SEM photograph of a cross section of the polymer body of Comparative Example 2. FIG. 4 is an SEM photograph of a cross section of the polymer body of Example 3. FIG.

Hereinafter, an embodiment of the invention will be described.

First, the polymer according to the present embodiment will be described by taking as an example a polishing pad polymer that is a polyurethane resin foam containing a polyurethane resin.

The polymer body according to the present embodiment is used as a part constituting at least a polishing surface in the polishing pad.

The polymer body according to the present embodiment is a polymer body containing a polyurethane resin.

The polyurethane resin is derived from a first structural unit derived from a compound containing a hydroxy group (hereinafter also referred to as “hydroxy compound”) and a compound containing an isocyanate group (hereinafter also referred to as “isocyanate compound”). A second structural unit.
One or more of the first structural units are derived from at least one of an organic cation containing a hydroxy group and an organic anion containing a hydroxy group.

The polyurethane resin is a resin in which a polyol as a hydroxy compound and a polyisocyanate as an isocyanate compound are combined.

The organic cation is taken into the molecule of the polyurethane resin by reacting the hydroxyl group with the isocyanate group of the isocyanate compound.
The organic cation may be a monol or a polyol. That is, the structural unit formed by the organic cation may be present at the terminal of the molecule of the polyurethane resin, or may be present inside the terminal rather than the terminal.

One or more of the first structural units are preferably derived from an organic cation containing a hydroxy group.
The structural unit derived from the organic cation is preferably derived from an ionic liquid.
The melting point of the ionic liquid is preferably 150 ° C. or less, and more preferably 100 ° C. or less.
In addition, melting | fusing point of an ionic liquid can be calculated | required, for example using a differential scanning calorimeter apparatus (DSC). More specifically, when the temperature of the sample (ionic liquid) is increased at a rate of temperature increase of 5 ° C./min while flowing nitrogen gas from a temperature 30 ° C. or more lower than the predicted melting point to a temperature higher than 30 ° C. It can obtain | require from the obtained DSC curve.
The ionic liquid preferably includes a cation having two or more hydroxy groups. When the ionic liquid includes a cation having two or more hydroxy groups, the resulting polymer can be charged with more charges due to the cation. As a result, the affinity with a liquid polar substance (such as water) can be further increased, and the difference in hardness between the state in contact with the liquid polar substance and the state not in contact with the liquid polar substance is further increased. There is an advantage that it can be enlarged.
Examples of the ionic liquid having a cation having two or more hydroxy groups include ionic liquids represented by the following formulas (1) to (3).
Moreover, as an ionic liquid provided with the cation which has only one hydroxy group, the ionic liquid of following formula (4) and (5) is mentioned, for example.
As the ionic liquid, an ionic liquid including a cation having two or more hydroxy groups is preferable from the viewpoint that many charges can be imparted in the molecule.

The organic anion is taken into the molecule of the polyurethane resin by reacting the hydroxyl group with the isocyanate group of the isocyanate compound.
The organic anion may be a monol or a polyol. That is, the structural unit formed by the organic anion may be present at the end of the molecule of the polyurethane resin, or may be present inside the end rather than the end.

The organic anion is derived from 2,2-bis (hydroxymethyl) butyric acid (DMBA) (compound of the following formula (6)) and the like. In DMBA, the “COOH group” can be dissociated into “COO ⁻ ” and “H ⁺ ”.

Examples of the polyol include a polyol monomer and a polyol prepolymer.

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, 5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol having a molecular weight of 400 or less, 1, And linear aliphatic glycols such as 8-octanediol and 1,9-nonanediol, such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 2- Butyl-2-eth Branched aliphatic glycols such as 1,3-propanediol and 2-methyl-1,8-octanediol, and fats such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and water-added bisphenol A Examples thereof include cyclic diols, and polyfunctional polyols such as glycerin, trimethylolpropane, tributyrolpropane, pentaerythritol, and sorbitol.

As the polyol monomer, ethylene glycol and diethylene glycol are preferable in that the strength at the time of reaction tends to be higher, the rigidity of the produced polishing pad containing foamed polyurethane is likely to be higher, and the cost is relatively low.

Examples of the polyol prepolymer include polyether polyol, polyester polyol, polyester polycarbonate polyol, and polycarbonate polyol. In addition, as a polyol prepolymer, the polyfunctional polyol prepolymer which has 3 or more of hydroxyl groups in a molecule | numerator is also mentioned.

Specifically, examples of the polyether polyol include polytetramethylene glycol (PTMG), polypropylene glycol (PPG), polyethylene glycol (PEG), and ethylene oxide-added polypropylene polyol.

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

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 and further reacting with an organic dicarboxylic acid. Product etc. are mentioned.

Examples of the polycarbonate polyol include diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, or polytetramethylene glycol, phosgene, diallyl carbonate ( For example, a reaction product with diphenyl carbonate) or cyclic carbonate (for example, propylene carbonate) can be used.

As the polyol prepolymer, those having a number average molecular weight of 800 to 8000 are preferable in that an elastic foamed polyurethane can be easily obtained. Specifically, polytetramethylene glycol (PTMG), ethylene oxide Addition polypropylene polyol is preferred.

Examples of the polyisocyanate include polyisocyanate and polyisocyanate prepolymer.

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

Examples of the aromatic diisocyanate include crude diphenylmethane diisocyanate (crude MDI) obtained by, for example, reacting an amine mixture obtained by condensing aniline and formaldehyde with phosgene in an inert solvent, and purifying the crude MDI. Diphenylmethane diisocyanate (pure MDI), polymethylene polyphenylene polyisocyanate (polymeric MDI), and modified products thereof can be used, and tolylene diisocyanate (TDI), 1,5-naphthalene diisocyanate, xylylene diisocyanate, 1 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate and the like can be used. In addition, these aromatic diisocyanates can be used alone or in combination.

Examples of the modified product of diphenylmethane diisocyanate include a carbodiimide modified product, a urethane modified product, an allophanate modified product, a urea modified product, a burette modified product, an isocyanurate modified product, and an oxazolidone modified product. 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 1,6-hexamethylene diisocyanate.

As the alicyclic diisocyanate, for example, 1,4-cyclohexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, norbornane diisocyanate, methylene bis (4,1-cyclohexylene) = diisocyanate and the like are used.

Examples of the polyisocyanate prepolymer include a prepolymer formed by bonding a polyol and at least one of an aromatic diisocyanate, an aliphatic diisocyanate, and an alicyclic diisocyanate.

As the polyisocyanate, diphenylmethane diisocyanate (pure MDI), polymeric MDI, or a modified product thereof is preferable in terms of easy control of the working environment because of its lower vapor pressure and less volatilization. In addition, carbodiimide-modified MDI, polymeric MDI, or a mixture of these with MDI is preferred in that it has a lower viscosity and is easy to handle.

The polyurethane resin preferably has a crosslinked structure.
The cross-linked structure is preferably derived from a polyfunctional compound having at least one functional group of an isocyanate group and a hydroxy group and having a total of three or more isocyanate groups and hydroxy groups.
As this polyfunctional compound, the compound of following formula (7) etc. are mentioned, for example. Here, “R” in “the following formula (7)” is “(C _n H _2n )” (n is a positive integer. For example, n = 1 to 10).
Examples of the compound of the following formula (7) include an isocyanurate form (R = C ₆ H ₁₂ ) of 1,6-hexamethylene diisocyanate.
Further, the polyfunctional compound may be a compound of the above formula (1) which is an ionic liquid.

The crosslinking concentration in the polyurethane resin is preferably 0.06 to 0.80 mmol / g.
The cross-linking concentration represents the amount of cross-linking points in 1 g of polyurethane resin in terms of mole unit.

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

In the method for producing a polymer according to this embodiment, a polymer having a polyurethane resin is obtained.
In the method for producing a polymer according to this embodiment, the polymer is obtained by bonding a compound containing a hydroxy group and a compound containing an isocyanate group.
In the method for producing a polymer according to this embodiment, specifically, a compound containing a hydroxy group, a compound containing an isocyanate group, and a foaming agent are mixed to obtain a mixture, and the mixture is polymerized and foamed. Thus, a polymer is obtained.
The compound containing a hydroxy group has at least one of an organic cation containing a hydroxy group and an organic anion containing a hydroxy group.

In the method for producing a polymer according to the present embodiment, preferably, the compound containing a hydroxy group has an organic cation containing a hydroxy group, the organic cation is derived from an ionic liquid, and the bond is bonded to the ion. Perform at a temperature above the melting point of the liquid.

The foaming agent is not particularly limited as long as the foamed polyurethane is molded so as to generate gas to form bubbles, and bubbles are formed in the foamed polyurethane. For example, the foaming agent is decomposed by heating. Thus, an organic chemical foaming agent that generates gas, a low-boiling hydrocarbon having a boiling point of −5 to 70 ° C., a halogenated hydrocarbon, water, liquefied carbon dioxide, or the like 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 and the like), sulfonyl hydrazide compounds [p, p′-oxybis (benzenesulfonyl hydrazide), p-toluenesulfonyl hydrazide and the like] and the like.
Examples of the low boiling point hydrocarbon include butane, pentane, cyclopentane, and mixtures thereof.
Examples of the halogenated hydrocarbon include methylene chloride and HFC (hydrofluorocarbons).

The foaming agent may be a heat-expandable microsphere. The particle size of the heat-expandable microsphere is, for example, 20 to 30 μm. The heat-expandable microsphere includes a hollow body formed of a thermoplastic resin and a liquid hydrocarbon provided in a hollow portion of the hollow body. Examples of the heat-expandable microspheres include Expandel (registered trademark) manufactured by Nippon Philite Co., Ltd., and thermally expandable microcapsules manufactured by Matsumoto Yushi Seiyaku Co., Ltd.

When water is used as a foaming agent when preparing a foamed polyurethane resin, water is easily dispersed in the mixture by the ionic compound, so that there is an advantage that the foamed polyurethane resin bubbles are likely to be fine. . In other words, there is an advantage that coarse bubbles are hardly generated in the polyurethane foam resin. As a result, there is an advantage that the object to be polished is hardly damaged.

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

Since the polymer body, the polishing pad, and the polymer body manufacturing method according to the present embodiment are configured as described above, they have the following advantages.

The polymer body according to the present embodiment is a polymer body containing a polyurethane resin.
The polyurethane resin includes a first structural unit derived from a compound containing a hydroxy group and a second structural unit derived from a compound containing an isocyanate group.
One or more of the first structural units are derived from at least one of an organic cation containing a hydroxy group and an organic anion containing a hydroxy group.
The polyurethane resin according to such a polymer has a chemical structure having at least one of a cation and an anion, and as a result, has a chemical structure excellent in affinity with a liquid polar substance (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 the polymer molecules of the polyurethane resin. As a result, this polyurethane resin has a lower hardness when in contact with the liquid polar substance than when not in contact with the liquid polar substance.
Therefore, such a polymer body is a polymer body having a lower hardness when in contact with a liquid polar substance than when not in contact with a liquid polar substance.
That is, such a polymer body is a polymer body having a low hardness under a specific situation.

In the polymer according to the present embodiment, preferably, the polyurethane resin has a crosslinked structure.
In such a polymer, since the polyurethane resin has a cross-linked structure, it can be prevented from being expanded by the liquid polar substance when it comes into contact with the liquid polar substance (water or the like). There is an advantage that deformation due to contact with a liquid polar substance can be suppressed.

Moreover, the polishing pad according to this embodiment includes the polymer.

Furthermore, the method for producing a polymer according to this embodiment is a method for producing a polymer that obtains a polymer containing a polyurethane resin.
Moreover, the manufacturing method of the high molecular body which concerns on this embodiment obtains the said high molecular body by combining the compound containing a hydroxyl group, and the compound containing an isocyanate group.
The compound containing a hydroxy group has at least one of an organic cation containing a hydroxy group and an organic anion containing a hydroxy group.

In the method for producing a polymer according to this embodiment, preferably, the compound containing a hydroxy group has an organic cation containing a hydroxy group. The organic cation is derived from an ionic liquid. In the method for producing a polymer according to the present embodiment, the bonding is performed at a temperature equal to or higher than the melting point of the ionic liquid.
In such a polymer production method, since the bonding is performed at a temperature equal to or higher than the melting point of the ionic liquid, it is easy to uniformly mix the ionic liquid and other materials before the bonding, and the uniformity is excellent. There is an advantage that a high polymer can be obtained.

As described above, according to the present embodiment, a polymer body having low hardness under a specific situation is provided, and a polishing pad including the polymer body and a polymer body for producing the polymer body are provided. Can be provided.

In addition, the polymer body, the polishing pad, and the polymer body manufacturing method according to the present invention are not limited to the above-described embodiment. Further, the polymer, the polishing pad, and the method for producing the polymer according to the present invention are not limited to the above-described effects. The polymer body, the polishing pad, and the method for producing the polymer body according to the present invention can be variously modified 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 body which concerns on this embodiment is a polyurethane resin foam, the polymer body which impregnated the polyurethane resin to the nonwoven fabric may be sufficient as the polymer body which concerns on this invention.
Furthermore, the polymer polyurethane resin according to the present invention may be formed by adding a micro hollow body to the mixture.

Further, the polymer according to the present embodiment is a polymer for a polishing pad, but the polymer according to the present invention may be used for other applications, for example, cosmetic materials, office use. It may be used as a sponge, a cleaning sponge, a filler for resin modification, or the like.

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

Example 1
A main agent was prepared by mixing a urethane prepolymer obtained by reacting tolylene diisocyanate (TDI), polypropylene glycol (PPG), and diethylene glycol (DEG) with a trimer of hexamethylene diisocyanate. Further, a curing agent was prepared by mixing an ionic liquid of the following formula (1), 1,4-benzenedimethanol and 1,4-bis (2-hydroxyethoxy) benzene. And the polymer was obtained by mixing the said main ingredient, the said hardening | curing agent, and water as a foaming agent, and making it react at 70 degreeC.
In addition, the density | concentration of the ionic liquid in a main ingredient, a hardening | curing agent, and a foaming agent was 5 mass%.

(Comparative Example 1)
Urethane prepolymer obtained by reacting tolylene diisocyanate (TDI), polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG), methylenebis-o-chloroaniline (MOCA) and water as a blowing agent Were mixed and reacted at 70 ° C. to obtain a polymer.

(Water absorption test)
The polymer bodies of Example 1 and Comparative Example 1 were subjected to a water absorption test.
That is, first, the mass (G1) of the polymer (length: 50 mm, width: 50 mm, height: 1 mm) was measured. Then, the polymer was immersed in warm water at 40 ° C. for 24 hours, and the mass (G2) of the polymer after immersion was measured. And the water absorption P was computed by the following formula.
P = (G2-G1) / G1 × 100 (%)

The water absorption rate of the polymer of Example 1 was 20%. On the other hand, the water absorption of the polymer of Comparative Example 1 was 5%.
Therefore, it can be seen that the polymer of Example 1 has a higher water absorption than the polymer of Comparative Example 1, and has a structure that easily absorbs water.

(Example 2)
A main agent was prepared by mixing a urethane prepolymer obtained by reacting tolylene diisocyanate (TDI), polypropylene glycol (PPG), and diethylene glycol (DEG) with a trimer of hexamethylene diisocyanate. Further, a curing agent was prepared by mixing an ionic liquid of the following formula (3) and 1,4-bis (2-hydroxyethoxy) benzene. And the said main ingredient, the said hardening | curing agent, and the water as a foaming agent were mixed, and the polymer was obtained by making it react at 70 degreeC.
In addition, the density | concentration of the ionic liquid in a main ingredient, a hardening | curing agent, and a foaming agent was 10 mass%.

(Comparative Example 2)
A polymer was obtained in the same manner as in Example 2 except that triethanolamine (TEOA) was used instead of the ionic liquid.

(Example 3)
A polymer was obtained in the same manner as in Example 2 except that 2,2-bis (hydroxymethyl) butyric acid (DMBA) was used instead of the ionic liquid.

(density)
The density (apparent density) was determined by measuring the length, width, and thickness of a rectangular parallelepiped test piece of the polymer and measuring the mass of the test piece.

(Hardness (JIS-A))
The hardness (JIS-A) was measured at 23 ° C. according to a hardness test according to JIS K7312-1996 type A.
The hardness when wet means the hardness of a polymer obtained by immersing the polymer in warm water at 40 ° C. for 24 hours.

(Hardness (Asker-C))
Hardness (Asker-C) was measured at 23 ° C. according to SRIR0101.
The hardness when wet means the hardness of a polymer obtained by immersing the polymer in warm water at 40 ° C. for 24 hours.

(Slice test)
A cylindrical polymer (diameter: 90 mm, thickness: 90 mm) was sliced with a blade to a thickness of 1 to 2 mm. Here, the polymer body was fixed, and the polymer body was sliced by moving the blade in the horizontal direction toward the polymer body. As the cutter, a cutter called a cemented carbide cutter, which was obtained by baking a mixture of tungsten carbide and cobalt, was used.
And it evaluated on the following references | standards.
Y: Can be sliced ×: Cannot be sliced

(Bubble size)
In order to confirm the size of the bubbles, a cross section of the polymer was photographed with a scanning electron microscope (SEM).

The results of SEM photographs are shown in Figs. The other results are shown in Table 1 below.

As shown in Table 1, the polymer bodies of Examples 2 and 3 were significantly lower in hardness due to contact with water than the polymer body of Comparative Example 2. Therefore, according to this invention, it turns out that it is a high molecular body from which hardness becomes low under a specific condition.

Moreover, as shown in Table 1, the hardness of the polymer of Example 2 was significantly reduced by contact with water compared to the polymer of Example 3. Therefore, it can be seen that the polymer body of Example 2 is a polymer body having a lower hardness under specific circumstances than the polymer body of Example 3.
This result is presumed to be due to the following reason. The polymer of Example 3 has a structure containing a carboxylic acid in the structural unit. Carboxylic acid has a pKa of about 4, and when it comes into contact with water at pH 7, it is considered that the carboxyl group becomes an anion of about 0.01%. On the other hand, most ionic liquids can be present as cations when in contact with water. As a result, it is considered that the hardness of the polymer of Example 2 was significantly reduced by contact with water compared to the polymer of Example 3.

As shown in FIGS. 1 to 3, the polymer of Example 2 had smaller bubbles than those of Comparative Example 2 and Example 3.

Claims (9)

A polymer containing a polyurethane resin,
The polyurethane resin comprises a first structural unit derived from a compound containing a hydroxy group and a second structural unit derived from a compound containing an isocyanate group,
A polymer in which one or more of the first structural units are derived from at least one of an organic cation containing a hydroxy group and an organic anion containing a hydroxy group. The polymer according to claim 1, wherein one or more of the first structural units are derived from an organic cation containing a hydroxy group. The polymer body according to claim 2, wherein the structural unit derived from the organic cation is derived from an ionic liquid. The polymer body according to any one of claims 1 to 3, wherein the polyurethane resin has a crosslinked structure. The polymer body according to any one of claims 1 to 4, which is a polyurethane resin foam containing the polyurethane resin. The polymer body according to any one of claims 1 to 5, which is used for a polishing pad and is used as a portion constituting at least a polishing surface of the polishing pad. A polishing pad comprising the polymer body according to claim 6. A method for producing a polymer, which obtains a polymer containing a polyurethane resin,
The polymer is obtained by bonding a compound containing a hydroxy group and a compound containing an isocyanate group,
The method for producing a polymer, wherein the compound containing a hydroxy group has at least one of an organic cation containing a hydroxy group and an organic anion containing a hydroxy group. The compound containing a hydroxy group has an organic cation containing a hydroxy group,
The organic cation is derived from an ionic liquid;
The method for producing a polymer according to claim 8, wherein the bonding is performed at a temperature equal to or higher than a melting point of the ionic liquid.

Images