TW201704340A - Polishing pad and process for producing same which is applied to chemical mechanical polishing and having high flatness and low polishing damage - Google Patents

Abstract

The present invention provides a polishing pad having a polyurethryl ester resin sheet that contains a desired tan [delta] peak temperature, wherein the polishing pad is provided with a polyurethane resin sheet which is obtained by reacting a polyisocyanate compound (B) with a polyol compound (C) containing a high molecular weight polyol having a number average molecular weight Mn to become a prepolymer (A) containing a isocyanate compound having polyurethane bonds that is further reacted with a hardener (D). And the polyurethane resin sheet satisfies the formula (1) by using the peak temperature Tpeak of tan [delta] that is measured by a dynamic viscoelasticity test at a measurement frequency of 10 rad/sec and a tensile mode, and the peal value tan [delta] peak of tan [delta] satisfies the formula (2) when the equivalent ratio of isocyanate groups contained in the active hydrogen group of the hardner at the terminal of the isocyanate compound (A) containing polyurethane bonds is R.

Description

Polishing pad and method of manufacturing same

The present invention relates to a polishing pad and a method of manufacturing the same. In particular, it relates to a polishing pad for chemical mechanical polishing (CMP) processing such as an optical material, a semiconductor element, a hard disk, or a glass substrate, and a method of manufacturing the same.

Since the surface of a material such as an optical material, a semiconductor element, a hard disk, or a glass substrate is required to be flat, polishing by a free abrasive grain method using a polishing pad is performed. The free abrasive grain method is a method in which a slurry (polishing liquid) containing abrasive grains is supplied to a polishing surface between the polishing pad and the workpiece to face the object to be polished.

The polishing pad for a semiconductor element is required to have an opening for holding the abrasive grains on the surface of the polishing pad, to maintain the rigidity of the flatness of the surface of the semiconductor element, and to prevent the scratch of the surface of the semiconductor element. As a polishing pad that meets such requirements, a polishing pad having a polishing layer produced using a urethane resin foam has been used.

The urethane resin foam is usually formed by curing by a reaction with a prepolymer and a hardener containing an isocyanate compound containing a polyurethane bond (dry method). Then, the polishing pad is formed by cutting the foam into a sheet shape. A polishing pad having a hard abrasive layer formed by a dry method in this manner (hereinafter sometimes referred to simply as a hard (dry) polishing pad) is formed in the inside of the foam during hardening of the urethane resin. The smaller, substantially spherical bubble forms an opening (opening) capable of maintaining the slurry during the polishing process on the polishing surface of the polishing pad formed by slicing.

Research on the need for higher flatness of the polishing pad or excellent inhibition of grinding damage Grinding characteristics, or higher grinding processability. In the polishing pad of the above-mentioned characteristics, it is known that the ratio of tan δ30 at 30° C. is 0.1 or less, and the ratio of tan δ 30 at 30° C. to tan δ 60 at 60° C. is 1 to 2, thereby improving the polishing processability. A polishing pad having improved flatness and polishing damage (Patent Document 1). In addition, a polishing pad which improves the flatness and the polishing damage by the maximum value of tan δ of 40 to 60 ° C is set to 0.2 or more (Patent Document 2).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-142439

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-142340

As described in Patent Documents 1 and 2, the peak temperatures of tan δ, tan δ, and/or tan δ are related to polishing properties or polishing treatment properties. However, according to Patent Documents 1 and 2, it is not possible to grasp how to set the tan δ of the polishing pad to a desired value, and it is necessary to trial and error until a polishing pad having a desired tan δ peak and peak temperature is obtained.

If there is a method of easily producing a polishing pad having a desired tan δ peak temperature and/or tan δ peak, a polishing pad having desired polishing characteristics and/or polishing treatment property can be easily obtained, thereby eliminating the need for trial and error previously performed. Therefore, there is a high demand for a manufacturing method of a polishing pad having a desired tan δ peak temperature and/or a tan δ peak.

The present invention has been made in view of the above problems, and an object thereof is to provide a method for producing a polishing pad comprising a polyurethane resin sheet having a desired tan δ peak temperature. Further, it is an object of the invention to provide a method for producing a polishing pad comprising a polyurethane resin sheet having a desired tan δ peak.

The inventors have made an effort to find the average number of high molecular weight polyols after careful efforts. The sub-quantity Mn has a fixed correlation with the peak temperature of tan δ. Further, it has been found that the active hydrogen group present in the hardener has a fixed correlation with the equivalence ratio R of the isocyanate groups present at the terminal of the polyurethane bond-containing isocyanate compound as a prepolymer and the peak of tan δ. The present invention is based on the above-described knowledge, and specifically has the following constitution.

[1] A polishing pad comprising a polyurethane resin sheet which is a mixture of a polyisocyanate compound (B) and a high molecular weight polyol having a number average molecular weight Mn. The alcohol compound (C) is reacted, and the obtained polyurethane bond-containing isocyanate compound (A) as a prepolymer is reacted with a hardener (D), and the above polyaminocarboxylic acid is obtained. The ester resin sheet has a peak temperature T _peak of tan δ measured by a dynamic viscoelasticity test at a measurement frequency of 10 rad/sec and a tensile mode, and satisfies the following formula (1), and the activity existing in the above hardener (D) When the equivalent ratio of the hydrogen group to the isocyanate group at the terminal of the polyisocyanate-containing isocyanate compound (A) is R, the peak tan δ _peak of tan δ satisfies the following formula (2).

-4.0×10 ^-5 ×Mn ² +0.15Mn-48<T _peak <-4.0×10 ^-5 ×Mn ² +0.15Mn-28 (1)

Tanδ _peak = C(R+1) (where C is a value satisfying the following formula (3)) (2)

1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.29<C<1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.31 (3)

[2] The polishing pad according to [1], wherein the high molecular weight polyol has a number average molecular weight Mn in the range of 600 to 2,500, and an equivalent ratio R in the range of 0.6 to 1.3.

[3] The polishing pad according to [1] or [2] wherein the polyisocyanate compound is 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate, and the high molecular weight polyol is poly(oxygen tetra Methylene)diol, and the above hardener is 3,3'-dichloro-4,4'-diaminodiphenylmethane.

[4] A manufacturing method which includes a method for manufacturing lines of the target tanδ peak temperature of the polishing pad of the T _peak of the polyurethane resin of the sheet, and comprising the steps of: determining molecular weight based on the following formula (1) The number average molecular weight Mn of the polyol; prepared by reacting the polyisocyanate compound (B) with a polyol compound (C) comprising a high molecular weight polyol having a number average molecular weight Mn determined according to formula (1) The polyisocyanate-containing isocyanate compound (A) of the polymer; at least the polyisocyanate-containing isocyanate compound (A) as a prepolymer is mixed with the hardener (D) to obtain a shape a mixture for molding a body; and molding a polyurethane resin molded article by using the mixed solution for molding a molded article to obtain a sheet of a polyurethane resin; and the tan δ is a utilization frequency of 10 rad/sec and a tensile mode The ratio of the loss elastic modulus E" relative to the storage elastic modulus E' measured by the dynamic viscoelasticity test.

-4.0×10 ^-5 ×Mn ² +0.15Mn-48<T _peak <-4.0×10 ^-5 ×Mn ² +0.15Mn-28 (1)

[5] The method according to [4], wherein the polyisocyanate compound (B) is 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate, and the above high molecular weight polyol is poly(oxytetrazide). Methyl)diol, and the above hardener (D) is 3,3'-dichloro-4,4'-diaminodiphenylmethane.

[6] The method according to [4] or [5], wherein the active hydrogen group present in the hardening agent (D) of the above-mentioned polyurethane resin sheet is present in a polyamine group as a prepolymer The equivalent ratio R of the isocyanate group at the terminal of the isocyanate compound (A) of the formate bond is in the range of 0.6 to 1.3.

[7] A method for producing a polishing pad comprising a polyurethane foil sheet having a target tan δ peak of tan δ _peak , and comprising the steps of: determining the polyamine based on the following formula (2) Equivalent ratio of the active hydrogen group present in the hardener (D) to the isocyanate group present at the end of the polyurethane bond-containing isocyanate compound (A) as a prepolymer R, the polyisocyanate compound-containing isocyanate compound (A) as a prepolymer is obtained by reacting a polyisocyanate compound (B) with a high molecular weight polyol having a number average molecular weight of Mn; The polyisocyanate compound (A) and the hardener (D) containing a polyurethane linkage as a prepolymer are prepared in such a manner that the equivalent ratio R is determined by the formula (2); at least the polyamine group as a prepolymer is contained. The isocyanate compound (A) of the formate bond and the curing agent (D) are mixed to obtain a mixed body for molding a molded article; and the polyurethane molded article is molded by the mixed solution for forming a molded article to obtain a polyamine. Carbamate resin sheet; And the above tan δ is a ratio of the loss elastic modulus E" to the storage elastic modulus E' measured by a dynamic viscoelasticity test using a frequency of 10 rad/sec and a tensile mode.

Tanδ _peak = C(R+1) (where C is a value satisfying the following formula (3)) (2)

1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.29<C<1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.31 (3)

[8] The method according to [7], wherein the polyisocyanate compound (B) is 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate, and the above polyol compound (C) is poly(oxygen tetra Methylene)diol, and the above hardener (D) is 3,3'-dichloro-4,4'-diaminodiphenylmethane.

[9] The method according to [8], wherein the number average molecular weight Mn of the poly(oxytetramethylene) glycol is in the range of from 600 to 2,500.

According to the present invention, a polishing pad having a sheet of a polyurethane resin having a desired tan δ peak temperature or a tan δ peak can be easily produced.

Fig. 1 is a graph showing the relationship between the temperatures of Examples 1 to 4 and tan δ.

Fig. 2 is a view showing an approximate formula derived from the number average molecular weight Mn of the poly(oxytetramethylene) glycol of Examples 1 to 4 and the peak temperature _{Tpeak of} tan δ.

Fig. 3 is a graph showing the relationship between the temperatures of Examples 5 to 9 and tan δ.

Fig. 4 is a view showing an approximate expression derived from the R value of Examples 5 to 9 and the peak tan δ _peak of tan δ.

Hereinafter, the present embodiment will be described.

(tan δ, storage elastic modulus E', loss elastic modulus E")

In the present specification and the scope of the patent application, tan δ is the ratio of the loss elastic modulus E" to the storage elastic modulus E', and is an index indicating the degree of viscosity under a certain temperature condition.

In the present specification and the scope of the patent application, the storage elastic modulus E' is a measure of the energy that is stored and completely recovered when a sinusoidally varying stress is applied to the polyurethane resin sheet. . Further, the loss elastic modulus E" means a magnitude of a stress component whose sinusoidal wave of the characteristic vibration amount is delayed by π/2 due to strain when strain is applied.

The storage elastic modulus E' and the loss elastic modulus E" are respectively based on JIS K7244 at a specific temperature (°C), a measurement frequency of 10 rad/sec, a storage elastic modulus E' in a tensile mode, and a loss elastic modulus. Number E".

(tan δ peak temperature)

In the present specification and the patent application, the peak temperature of tan δ means the temperature at which the value of tan δ becomes maximum when the tan δ is measured at each temperature while changing the temperature (that is, the temperature at which tan δ becomes a peak). . The value of tan δ of the polyurethane resin sheet increases before a certain temperature, but if it exceeds this temperature, it decreases. Therefore, there is a peak temperature of tan δ.

In addition, the "peak temperature of tan δ of the target" is a temperature at which the urethane resin sheet produced is desired to have a peak temperature of tan δ.

(peak of tan δ)

In the present specification and the patent application, the peak value of tan δ means the maximum value of tan δ when tan δ is measured at each temperature while changing the temperature.

In addition, the "peak of the tan δ of the target" is a value which is desired as a peak of tan δ which is obtained from the urethane resin sheet.

<<The first aspect>>

A first aspect of the present invention is a polishing pad comprising a polyurethane resin sheet which has a high polyisocyanate compound (B) and a number average molecular weight Mn. The polyol compound (C) of a molecular weight polyol is reacted, and the obtained isocyanate compound (A) containing a polyurethane linkage as a prepolymer is reacted with a hardener (D), and the above The urethane resin sheet has a peak temperature T _peak of tan δ measured by a dynamic viscoelasticity test at a measurement frequency of 10 rad/sec and a tensile mode, and satisfies the following formula (1), and the above hardener (D) When the equivalent ratio of the active hydrogen group present in the terminal isocyanate group containing the polyurethane bond-containing isocyanate compound (A) is R, the peak tan δ _peak of tan δ satisfies the following formula (2) .

-4.0×10 ^-5 ×Mn ² +0.15Mn-48<T _peak <-4.0×10 ^-5 ×Mn ² +0.15Mn-28 (1)

Tanδ _peak = C(R+1) (where C is a value satisfying the following formula (3)) (2)

1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.29<C<1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.31 (3)

<<The second aspect>>

A second aspect of the present invention is a method for producing a polishing pad comprising a polyurethane foil sheet having a target tan δ peak temperature of T _peak , and comprising the following steps: 1) determining the number average molecular weight Mn of the high molecular weight polyol; by subjecting the polyisocyanate compound (B) to a polyol compound (C) comprising a high molecular weight polyol having a number average molecular weight Mn determined according to formula (1) Preparation of a polyurethane-containing isocyanate compound (A) as a prepolymer; at least a polyurethane-containing isocyanate compound (A) and a hardener (D) as a prepolymer The mixture is mixed to obtain a mixed body for molding a molded article; and the polyurethane molded article is molded by the mixed solution for forming a molded article to obtain a polyurethane film; and the tan δ is used at a frequency of 10 radians/ The ratio of the loss elastic modulus E" relative to the storage elastic modulus E' measured by the dynamic viscoelasticity test of the second and tensile modes.

-4.0×10 ^-5 ×Mn ² +0.15Mn-48<T _peak <-4.0×10 ^-5 ×Mn ² +0.15Mn-28 (1)

<<The third aspect>>

A third aspect of the present invention is a method for producing a polishing pad comprising a polyurethane urethane resin sheet having a target tan δ peak of tan δ _peak , and comprising the following steps: based on the following formula (2) Determining the active hydrogen group present in the hardener (D) of the above-mentioned polyurethane resin sheet with respect to the end of the isocyanate compound (A) present as a prepolymer containing a polyurethane bond The equivalent ratio R of the isocyanate group, the isocyanate compound (A) containing a polyurethane bond as a prepolymer is obtained by reacting a polyisocyanate compound (B) with a high molecular weight polyol having a number average molecular weight of Mn. Preparing a polyurethane-containing isocyanate compound (A) and a hardener (D) as a prepolymer in such a manner as to be equivalent to R determined by the above formula (2); at least as a prepolymer The polyisocyanate compound-containing isocyanate compound (A) and the curing agent (D) are mixed to obtain a mixed body for molding a molded article; and the polyurethane molding resin is formed by molding the mixed body for forming the molded article. Polyamine Ester resin sheet; and said tanδ is using the frequency 10 rad / sec and by measurement of dynamic viscoelasticity test of tensile mode loss modulus E "ratio of the storage elastic modulus of the phase E 'for it.

Tanδ _peak = C(R+1) (where C is a value satisfying the following formula (3)) (2)

1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.29<C<1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.31 (3)

The urethane resin sheet of each of the above aspects is a flaky resin having at least two or more urethane bonds in the molecule. The above-mentioned polyurethane resin sheet preferably has at least two or more urethane bonds and at least two or more urea bonds in the molecule. The polyurethane resin sheet of the present invention and a polishing pad comprising the resin sheet can be produced, for example, according to the production method of the present invention described later.

Further, the polyurethane resin sheet preferably has minute bubbles which are substantially spherical. The term "substantially spherical" means the concept of ordinary bubble shapes (having isotropy, spherical, elliptical, or similar shapes) existing in a molded body formed by a dry method, and utilizing The shape of the bubble contained in the formed body formed by the wet method (having anisotropy and having a structure in which the diameter of the polishing layer from the polishing pad becomes larger toward the bottom) is clearly distinguished.

The manufacturing method of the second aspect comprises the step of reacting the polyisocyanate compound (B) with a polyol compound (C) comprising a high molecular weight polyol having a number average molecular weight Mn determined according to the formula (1). Preparation of a polyurethane-containing isocyanate compound (A) as a prepolymer (prepolymer preparation step); at least a polyurethane bond-containing isocyanate compound (A) as a prepolymer and The hardener (D) is mixed to obtain a mixed liquid for molding a molded body (mixing step); and the polyurethane molded article is molded by the mixed liquid for forming the molded body to obtain a polyurethane resin sheet ( Forming body forming step).

The manufacturing method of the third aspect comprises the steps of mixing at least a polyurethane-containing isocyanate compound (A) as a prepolymer and a hardener (D) to obtain a shape. The mixture for forming a body (mixing step); and molding the polyurethane resin molded article by the above-mentioned mixed solution for forming a molded body to obtain a polyurethane resin sheet (molded body forming step).

The isocyanate compound (A) containing a polyurethane linkage as a prepolymer as in the production method of the third aspect can be, for example, as described in the preparation step of the prepolymer of the second aspect, by making the polyisocyanate compound (B) is prepared by reacting with a polyol compound (C).

Further, in the third aspect, the isocyanate compound (A) and the hardener (D) containing the polyurethane linkage as the prepolymer are prepared in such a manner that the equivalent ratio R is determined based on the formula (2). The step of the step can be easily carried out by adjusting the ratio of the amount of the isocyanate compound (A) containing the polyurethane bond to the hardener (D).

Hereinafter, each step will be described.

<Prepolymer preparation step>

The prepolymer preparation step is carried out by reacting a polyisocyanate compound (B) with a polyhydric alcohol compound (C) containing poly(oxytetramethylene) glycol to prepare a polyurethane containing a prepolymer. Key isocyanate compound (A).

Hereinafter, each component will be described.

[(A) Isocyanate compound containing a polyurethane linkage]

The isocyanate compound (A) containing a polyurethane linkage as a prepolymer is a compound obtained by reacting the following polyisocyanate compound (B) with a polyol compound (C) under usual use conditions, And it is a molecule containing a polyurethane bond and an isocyanate group in a molecule. Further, other components may be contained in the isocyanate compound containing a polyurethane bond within the range in which the effects of the present invention are not impaired.

The reaction of the polyisocyanate compound (B) for preparing a prepolymer and the polyol compound (C) is not particularly limited, and an addition polymerization reaction can be carried out by using a known method and conditions in the production of a polyurethane resin. . For example, it can be produced by adding a polyisocyanate heated to 40 ° C under a nitrogen atmosphere while adding a polyisocyanate heated to 50 ° C. The ester compound was allowed to warm up to 80 ° C after 30 minutes, and further reacted at 80 ° C for 60 minutes.

[(B) Polyisocyanate Compound]

In the specification and the patent application, the polyisocyanate compound means a compound having two or more isocyanate groups in the molecule.

The polyisocyanate compound (B) is not particularly limited as long as it has two or more isocyanate groups in the molecule. For example, examples of the diisocyanate compound having two isocyanate groups in the molecule include m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-toluene diisocyanate (2,6-TDI), and 2,4-toluene diisocyanate. (2,4-TDI), naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), 4,4'-methylene-bis(cyclohexyl isocyanate) (hydrogenated MDI , 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, benzenedimethyl-1, 4-diisocyanate, 4,4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propyl-1,2-diisocyanate, butyl-1,2-di Isocyanate, cyclohexyl-1,2-diisocyanate, cyclohexyl-1,4-diisocyanate, p-phenylene isothiocyanate, benzodimethyl-1,4-diisothiocyanate, Ethyl diisothiocyanate or the like.

The polyisocyanate compound is preferably a diisocyanate compound, more preferably 2,4-TDI, 2,6-TDI, MDI, more preferably 2,4-TDI or 2,6-TDI, and particularly preferably 2,4-TDI.

These polyisocyanate compounds (B) may be used singly or in combination of a plurality of polyisocyanate compounds.

[(C) Polyol Compound]

In the specification and the patent application, the term "polyol compound" means a compound having two or more alcoholic hydroxyl groups (OH) in the molecule.

The polyol compound (C) used in the synthesis of the polyurethane bond-containing isocyanate compound as the prepolymer contains poly(oxytetramethylene) glycol (PTMG). Polyol The compound (C) may be only poly(oxytetramethylene) glycol, and may also contain a polyol compound other than poly(oxytetramethylene) glycol. Examples of the polyhydric alcohol compound other than poly(oxytetramethylene) glycol include glycol compounds such as ethylene glycol, diethylene glycol (DEG), and butanediol, and triol compounds; and poly(oxytetrazide). Polyether polyol compound other than methyl diol (PTMG); polyester polyol compound such as reaction of ethylene glycol with adipic acid or reaction of butane diol with adipic acid; polycarbonate polyol compound , polycaprolactone polyol compound, and the like. Further, a trifunctional propylene glycol which is added with ethylene oxide can also be used.

The polyol compound other than the above poly(oxytetramethylene) glycol may be used singly or in combination of plural polyol compounds.

Among these, the polyol compound (C) preferably contains PTMG, more preferably PTMG or a combination of PTMG and DEG. In the case where PTMG is used in combination with DEG, the mass ratio of DEG to 1000 parts by mass of PTMG is preferably 50 to 300 parts by mass, more preferably 100 to 200 parts by mass.

The number average molecular weight (Mn) of the PTMG is preferably from 600 to 2,500, more preferably from 600 to 2,200, still more preferably from 800 to 1200, more preferably from 800 to 1,000, and even more preferably from 800 to 900. When the number average molecular weight of the PTMG is within the above range, it is easy to control the peak temperature _{Tpeak of} tan δ based on the formula (1).

The number average molecular weight can be determined by gel permeation chromatography (GPC). In the case where the number average molecular weight of the polyol compound contained in the polyurethane resin is measured, each component may be decomposed by a conventional method such as amine decomposition and then estimated by GPC.

(NCO equivalent of prepolymer)

In addition, "(parts by mass of polyisocyanate compound (B) + parts by mass of polyol compound (C)) / [(number of functional groups of one molecule of polyisocyanate compound (B) × part by mass of polyisocyanate compound (B) / Molecular weight of polyisocyanate compound (B) - (polyol compound (C) 1 molecule functional group × polyol compound (C) parts by mass / polyol compound (C) molecule The NCO equivalent of the prepolymer obtained by the amount) represents the molecular weight of the PP (prepolymer) of one NCO group. The NCO equivalent is preferably from 200 to 800, more preferably from 300 to 700. More preferably 400~600, especially 500~600.

<mixing step>

In the mixing step, at least a polyurethane-containing isocyanate compound (A) and a curing agent (D) as a prepolymer are mixed and used as a raw material of a polyurethane resin sheet. Further, it is also possible to combine the components other than the above without departing from the effects of the present invention.

Hereinafter, components other than the isocyanate compound (A) containing a polyurethane bond will be described.

[(D) hardener]

The production method of the present invention is a step of mixing a curing agent (also referred to as a chain extender) with an isocyanate compound containing a polyurethane bond in a mixing step. By adding a hardener, in the subsequent molding step of the shaped body, the main chain end of the polyisocyanate-containing isocyanate compound as a prepolymer is bonded to a hardener to form a polymer chain, and is hardened. .

As the hardener, for example, a polyamine compound (D-1) and/or a polyol compound (D-2) can be used.

((D-1) polyamine compound)

In the present specification and the scope of the patent application, the term "polyamine compound" means a compound having two or more amine groups in the molecule.

As the polyamine compound (D-1), an aliphatic or aromatic polyamine compound, particularly a diamine compound, may be used, and examples thereof include ethylenediamine, propylenediamine, hexamethylenediamine, and isophor. Ketodiamine, dicyclohexylmethane-4,4'-diamine, 3,3'-dichloro-4,4'-diaminodiphenylmethane (also known as methylene bis-o-chloroaniline) (hereinafter, abbreviated as MOCA), a polyamine compound having the same structure as MOCA, and the like. Also, the polyamine compound may have a hydroxyl group. Examples of such an amine-based compound include 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, and di-2-hydroxyethylpropylenediamine. , 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, and the like.

The polyamine compound is preferably a diamine compound, more preferably MOCA, diaminodiphenylmethane or diaminodiphenylphosphonium, and particularly preferably MOCA.

The polyamine compound (D-1) may be used singly or in combination of a plurality of polyamine compounds (D-1).

In order to make it easy to mix with other components and/or to increase the uniformity of the bubble diameter in the subsequent formed body forming step, the polyamine compound (D-1) is preferably decompressed as needed in the heated state. Defoaming. The defoaming method under reduced pressure may be a method known in the production of polyurethane, and for example, defoaming may be performed using a vacuum pump at a vacuum of 0.1 MPa or less.

When a solid compound is used as a curing agent (chain extender), it can be defoamed under reduced pressure while being melted by heating.

(Polyol compound which can be used after (D-2) prepolymer synthesis)

Further, in the present invention, in addition to the polyol compound (C) for forming an isocyanate group-containing compound as the prepolymer, a polyol compound (D-2) may be additionally used as a curing agent.

The polyol compound (D-2) can be used without particular limitation as long as it is a compound such as a diol compound or a triol compound. Further, it may be the same as or different from the polyol compound (C) for forming the prepolymer.

Specific examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,3-butylene glycol, and 1,4-butanediol. Low molecular weight diol such as pentanediol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, polytetramethylene glycol, polyethylene glycol, polypropylene glycol, etc. A high molecular weight polyol compound or the like.

The above polyol compound (D-2) may be used singly or in combination of plural polyols The substance (D-2) was used in combination.

As the hardener (D), a polyamine compound (D-1) can be used, and a polyol compound (D-2) can also be used, and a mixture of these can also be used. Among them, it is preferred to use a polyamine compound (D-1), and it is particularly preferred to use MOCA.

(R value)

In the method for producing a polishing pad of the present invention, it is preferred to use an active hydrogen group (amine group and hydroxyl group) present in the curing agent (D) with respect to the isocyanate containing the polyurethane bond as a prepolymer. The components are mixed in such a manner that the equivalent ratio of the isocyanate groups at the terminal of the compound (A) is from 0.60 to 1.40. The R value is preferably from 0.65 to 0.1.30, more preferably from 0.70 to 1.20.

When the R value is within the above range, it is easy to control the peak tan δ _{peak of} tan δ based on the formula (2).

[Other optional ingredients]

In the method for producing a polishing pad of the present invention, a hollow body can be used to contain bubbles inside the polyurethane resin molded body.

The term "hollow body" means a microsphere having a void. The microspheres include a spherical shape, an elliptical shape, and a shape similar to the above. Examples of the hollow body include heating and expansion of an unfoamed heat-expandable microsphere composed of a shell (polymer shell) containing a thermoplastic resin and a low-boiling hydrocarbon contained in the shell. The average particle diameter of the hollow body can be, for example, 5 to 130 μm. The average particle diameter can be measured, for example, by a laser diffraction type particle size distribution measuring apparatus (for example, manufactured by Spectris, Mastersizer 2000).

As the polymer shell, as disclosed in Japanese Laid-Open Patent Publication No. SHO 57-137323, for example, an acrylonitrile-vinylidene chloride copolymer, an acrylonitrile-methyl methacrylate copolymer, or a vinyl chloride- A thermoplastic resin such as an ethylene copolymer. Also, as the low boiling point hydrocarbon contained in the polymer shell, for example, isobutane, pentane, isopentane, petroleum ether or the like can be used.

Further, in addition to the above components, the previously used foaming agent may be added to the extent that the effects of the present invention are not impaired, and a non-reactive gas may be blown into each of the above components in the mixing step described below. The foaming agent may, for example, be a foaming agent containing water or a hydrocarbon having 5 or 6 carbon atoms as a main component. Examples of the hydrocarbon include a chain hydrocarbon such as n-pentane or n-hexane, or an alicyclic hydrocarbon such as cyclopentane or cyclohexane.

Further, in addition to the above components, a known foam stabilizer, a flame retardant, a colorant, a plasticizer or the like may be added.

In the mixing step, at least a polyurethane-containing isocyanate compound (A) and a curing agent (D) as a prepolymer are supplied to a mixer, stirred and mixed. The mixing order is not particularly limited, and a mixture of a mixture of the isocyanate compound (A) containing a polyurethane bond and a mixture of a curing agent (D) and other components as needed is preferably prepared. The two mixed solutions were supplied to the mixer for mixing and stirring. In this way, a mixed liquid for forming a shaped body can be prepared. The mixing step is carried out while heating to a temperature at which the fluidity of each of the above components can be ensured.

For example, a prepolymer (isocyanate containing polyisocyanate) solution heated to 40 ° C to 80 ° C may be stirred with a hardener (D) heated to 40 ° C to 130 ° C. The mixture may be mixed in a tank with a sleeve attached to the mixer as needed to be cooked. The stirring time is appropriately adjusted according to the number of teeth or the number of revolutions, the gap, and the like of the mixer, and is, for example, 0.5 to 4.0 seconds.

<Forming body forming step>

In the molded body forming step, the mixture for molding a molded body prepared in the above mixing step is poured into a mold frame of 50 to 100 ° C to be cured to form a polyurethane resin. At this time, since the prepolymer reacts with the curing agent to form a polyurethane resin, the mixed solution is hardened.

The polyurethane resin molded body obtained by the above-described molded body forming step is thereafter cut into a sheet shape to form a polyurethane resin sheet. By performing slicing, it is possible to provide openings in the surface of the sheet. At this time, in order to form an excellent wear resistance and it is not easy to block The opening of the grinding surface can be aged at 80~120 °C for about 1 hour to 10 hours.

The polyurethane resin sheet obtained in this manner is then attached to a surface opposite to the polishing surface by a double-sided tape and cut into a specific shape, preferably in the form of a disk, to form a polishing of the present invention. pad. The double-sided tape is not particularly limited and can be arbitrarily selected from among double-sided tapes well known in the art.

Further, the polishing pad may be a single layer structure of a polyurethane resin sheet, or may be attached to another surface (lower layer, support layer) on the opposite side to the polished surface of the polyurethane resin sheet. Multiple layers. The characteristics of the other layers are not particularly limited, and it is preferred that the surface opposite to the polished surface is bonded to a layer which is softer than the polyurethane resin sheet (having a small hardness or D hardness). The flatness of the polishing is further improved by providing a layer which is softer than the urethane resin sheet.

In the case of having a plurality of layers, the plurality of layers are pressed and adhered to each other using a double-sided tape or an adhesive as needed. The double-sided tape or the adhesive used in this case is not particularly limited, and can be optionally used from among double-sided tapes or adhesives known in the art.

Further, the polishing pad may be subjected to grinding treatment on the polishing surface and/or the back surface as needed, or groove processing or embossing processing or hole processing (punching processing) may be performed on the polishing surface, and the substrate and/or the adhesive layer may be aggregated. The urethane resin sheet is bonded to each other and may further include a light transmitting portion.

The method of the grinding treatment is not particularly limited, and the grinding can be carried out by a known method. Specifically, grinding by sandpaper is mentioned.

The shape of the groove processing and the embossing processing is not particularly limited, and examples thereof include a lattice shape, a concentric shape, and a radial shape.

When the polishing pad is used, the polishing pad is attached to the polishing platen of the grinder so that the polishing surface of the urethane resin sheet faces the object to be polished. Then, while the abrasive slurry is supplied, the polishing platen is rotated to polish the processed surface of the object to be polished.

The polishing pad obtained by the method of the present invention can be preferably used for grinding hard disks and glass Glass substrate, mother glass for thin display, semiconductor wafer, semiconductor device, etc. Among these, the polishing pad is particularly preferably used for chemical mechanical polishing (CMP) processing of semiconductor elements.

(thickness)

The thickness of the urethane resin sheet of the polishing pad is not particularly limited, and can be, for example, 0.2 to 3.0 mm, preferably 0.5 to 1.5 mm.

As described above, using the method of the present invention, it can be easily obtained having the desired peak temperature T _peak of tan [delta] and / or tan [delta] peak of tanδ _peak of the polishing pad. As described in Patent Documents 1 and 2, the peak temperature or peak value of tan δ is related to polishing properties or polishing treatment properties. Therefore, the polishing pad excellent in polishing properties or polishing treatability can be easily produced by the method of the present invention.

[Examples]

Hereinafter, the present invention will be described in further detail by way of examples, but the invention is not limited by the examples.

In the respective examples and comparative examples, "parts" means "parts by mass" unless otherwise specified.

Further, the respective symbols in Tables 1 to 2 mean the following.

The NCO equivalent means "(the mass of the polyisocyanate compound (B) + the mass (part) of the polyol compound (C)) / [(the number of functional groups of the polyisocyanate compound (B) 1 molecule × polyisocyanate The mass (parts) of the compound (B) / the molecular weight of the polyisocyanate compound (B)) - (the number of functional groups of the polyol compound (C) 1 molecule × the mass (parts) of the polyol compound (C) / the polyol compound (C) The molecular weight of the prepolymer (PP) of one NCO group obtained by molecular weight)]".

The R value is, as described above, the value of the equivalent ratio of the active hydrogen group (amine group and hydroxyl group) present in the hardener to the terminal isocyanate group in the prepolymer.

[Example 1]

Will make 770 parts of toluene diisocyanate (2,4-TDI) with 1000 parts of the average molecular weight of 650 The isocyanate-terminated urethane prepolymer obtained by the reaction of PTMG and 155 parts of a mixed diol of diethylene glycol was added to the first tank, and the temperature was maintained at 80 °C. The MOCA as a hardener was added to the second tank, and the temperature was kept at 120 °C. Each of the first liquid tank (1000 parts) and the second liquid tank (238 parts) was injected into the mixer having two injection ports at the above ratio from the respective injection ports, and the mixture was stirred and faced with two kinds of liquids. The mold of the molding machine heated to 80 ° C was injected, and thereafter, the mold was clamped, and it was once hardened by heating at a mold temperature of 80 ° C for 30 minutes. The molded product which had been hardened once was demolded, and thereafter, it was subjected to secondary hardening at 120 ° C for 5 hours in an oven to obtain a urethane molded product. The obtained urethane molded product was cut into a thickness of 1.3 mm to obtain a polishing pad. The R ratio of the equivalent ratio of the isocyanate of the prepolymer to the amine of the hardener is 1.23.

[Embodiment 2]

A polishing pad was obtained by the same method as in Example 1 except that PTMG having a molecular weight of 850 was used.

[Example 3]

A polishing pad was obtained in the same manner as in Example 1 except that PTMG having a molecular weight of 1,000 was used.

[Example 4]

A polishing pad was obtained in the same manner as in Example 1 except that PTMG having a molecular weight of 2,000 was used.

[Example 5]

Will make 770 parts of toluene diisocyanate (2,4-TDI) with 1000 parts of the average molecular weight of 850 The isocyanate-terminated urethane prepolymer obtained by the reaction of PTMG and 155 parts of a mixed diol of diethylene glycol was added to the first tank, and the temperature was maintained at 60 °C. 170 parts of MOCA was added to the second tank, and the temperature was maintained at 120 °C. The mixing was carried out at a ratio of R value of 0.7, and the subsequent steps were carried out in the same manner as in Example 1 to obtain a polishing pad.

[Embodiment 6]

A polishing pad was obtained in the same manner as in Example 5 except that the number of parts of MOCA was changed to 194 parts. The R value is 0.80.

[Embodiment 7]

A polishing pad was obtained in the same manner as in Example 5 except that the number of parts of MOCA was changed to 218 parts. The R value is 0.90.

[Embodiment 8]

A polishing pad was obtained in the same manner as in Example 5 except that the number of parts of the MOCA was 238 parts. The R value was 0.98.

[Embodiment 9]

A polishing pad was obtained in the same manner as in Example 5 except that the number of parts of MOCA was changed to 291 parts. The R value is 1.20.

<physical property>

For each of the above examples and comparative examples, the RSAIII manufactured by TA Instruments has an initial load of 10 to 700 g, a strain range of 0.1 to 1.0%, a measurement frequency of 10 rad/sec, and a temperature increase rate of 3 ° C/min to raise the temperature from 20 ° C. Test piece up to 100 ° C 5 mm × 10 mm The storage elastic modulus E', the loss elastic modulus E", and tan δ were measured. The detailed conditions are as follows.

Measuring device: TA Instruments Japan RSAIII

Test direction: stretching

Test piece: 5 × 10mm

Load: 200g

Strain: 0.1%

Frequency: 10 radians/second (=1.59 Hz)

Temperature: 20~100°C

Sample thickness: 1.3

<Result 1>

With respect to the polishing pads of Examples 1 to 4, the values of tan δ at each temperature were plotted in Fig. 1 (in Fig. 1, the horizontal axis represents temperature (°C) and the vertical axis represents tan δ).

As a result, it was found that by changing the number average molecular weight Mn of PTMG, the peak temperatures of peaks _Tpeak and tan δ of tan δ were changed.

Therefore, whether or not there is a correlation between the number average molecular weight Mn of the PTMG of Examples 1 to 4 and the peak temperature _{Tpeak of} tan δ has been studied, and as a result, as shown in Fig. 2, a secondary functional correlation (correlation coefficient 0.99) was found. In the above) (in Fig. 2, the horizontal axis represents the number average molecular weight Mn of PTMG, and the vertical axis represents the peak temperature _Tpeak of tan δ).

According to the above, it was found: the more the number-average molecular weight Mn of the PTMG is increased, the greater the tanδ of the polyurethane resin sheet of the peak temperature T _peak, specifically, the above can be used by a number average molecular weight Mn and the following Equation (1) is controlled.

-4.0×10 ^-5 ×Mn ² +0.15Mn-48<T _peak <-4.0×10 ^-5 ×Mn ² +0.15Mn-28 (1)

<Result 2>

For the polishing pads of Examples 5 to 9, the values of tan δ at each temperature are plotted. In Fig. 3 (in Fig. 3, the horizontal axis is temperature (°C) and the vertical axis is tan δ).

As a result, it was found that by changing the R value, the peak tan δ _peak of tan δ was changed.

Therefore, whether or not there is a correlation between the R values of Examples 5 to 9 and the peak tan δ _peak of tan δ has been studied. As a result, as shown in Fig. 4, a functional correlation (correlation coefficient of 0.99 or more) was found (Fig. 4). In the middle, the horizontal axis represents the R value, and the vertical axis represents the peak tan δ _peak of tan δ.

It can be seen that in Examples 5 to 9 in which PTMG having a number average molecular weight of 850 is used, as shown in FIG. 4, between the R value and the peak tan δ _peak of tan δ, there is 0.076R + 0.076 ≦ tan δ _peak ≦ 0.093R + 0.093

And the relationship between performance.

Further, by changing the number average molecular weight of PTMG and performing the same measurement, it is found that there is tan δ _peak = C (R + 1) between the R value and the peak tan δ _{peak of} tan δ (C is varied according to the number average molecular weight Mn of PTMG). The following values) (2)

And the performance is related once.

(If the number average molecular weight is 650, the constant C=0.110~0.127; if the molecular weight is 850, then C=0.076~0.093; if the molecular weight is 1000, C=0.051~0.068; if the molecular weight is 2000, then C=0.041~ 0.058)

It is understood that C in the above formula (2) uses the number average molecular weight Mn of PTMG, and is represented by the following formula (3).

1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.29<C<1.2×10 ^-7 ×Mn ² -3.6×10 ^-4 ×Mn+0.31 (3)

From the above, it has been found that the larger the value of tan, the larger the tan δ _peak of tan δ of the polyurethane resin sheet, and specifically, the R value can be controlled by the above formula (2).

[Industrial availability]

According to the present invention, it is possible to easily manufacture a temperature having a desired tan δ peak and/or tan δ A polishing pad of a peak polyurethane resin sheet. Therefore, the present invention is industrially available.

Claims (9)

A polishing pad comprising a polyurethane resin sheet which is a polyisocyanate compound (B) and a polyol compound containing a high molecular weight polyol having a number average molecular weight of Mn ( C) a reaction is carried out by reacting an isocyanate compound (A) containing a polyurethane bond as a prepolymer with a curing agent (D); and using the above-mentioned polyurethane resin sheet for measurement The peak temperature T _peak of tan δ measured by the dynamic viscoelasticity test at a frequency of 10 rad/sec and the tensile mode satisfies the following formula (1); and the active hydrogen group present in the above hardener (D) is present in relation to the presence When the equivalent ratio of the isocyanate group at the terminal of the polyurethane bond-containing isocyanate compound (A) is R, the peak tan δ _peak of tan δ satisfies the following formula (2): -4.0 × 10 ^-5 × Mn ² +0.15Mn-48<T _peak <-4.0×10 ^-5 ×Mn ² +0.15Mn-28 (1) tanδ _peak =C(R+1) (wherein C is a formula (3) Numerical value) (2) 1.2 × 10 ^-7 × Mn ^{2 -} 3.6 × 10 ^-4 × Mn + 0.29 < C < 1.2 × 10 ^-7 × Mn ^{2 -} 3.6 × 10 ^-4 × Mn + 0.31 (3). The polishing pad of claim 1, wherein the number average molecular weight Mn of the high molecular weight polyol is in the range of 600 to 2500; and the equivalent ratio R is in the range of 0.6 to 1.3. The polishing pad of claim 1 or 2, wherein the polyisocyanate compound is 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate; and the high molecular weight polyol is poly(oxytetramethylene) glycol. And the above hardener is 3,3'-dichloro-4,4'-diaminodiphenylmethane. A method for producing a polishing pad having a target tan δ peak temperature of a _peak of a polyurethane coating, comprising the steps of: determining a number average molecular weight Mn of a high molecular weight polyol based on the following formula (1); The polyaminol group as a prepolymer is prepared by reacting a polyisocyanate compound (B) with a polyol compound (C) comprising a high molecular weight polyol having a number average molecular weight Mn determined according to formula (1). An isocyanate compound (A) having an acid ester bond; at least a mixture of a polyurethane bond-containing isocyanate compound (A) as a prepolymer and a curing agent (D) to obtain a mixed body for molding a molded body; The polyurethane molding resin molded body was molded into the mixed body for forming a molded body to obtain a polyurethane resin sheet; and the tan δ was measured by a dynamic viscoelasticity test using a frequency of 10 rad/sec and a tensile mode. The ratio of the loss elastic modulus E" to the storage elastic modulus E': -4.0 × 10 ^-5 × Mn ² + 0.15 Mn - 48 < T _peak < - 4.0 × 10 - ⁵ × Mn ² + 0.15 Mn-28 (1). The method of claim 4, wherein the polyisocyanate compound (B) is 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate; and the high molecular weight polyol is poly(oxytetramethylene) glycol. And the above hardener (D) is 3,3'-dichloro-4,4'-diaminodiphenylmethane. The method of claim 4 or 5, wherein the active amino group present in the hardening agent (D) of the above-mentioned polyurethane resin sheet is present in relation to the polyurethane-containing bond present as a prepolymer. The equivalent ratio R of the isocyanate groups at the terminal of the isocyanate compound (A) is in the range of 0.6 to 1.3. A method for producing a polishing pad comprising a polyurethane foil sheet having a target tan δ peak tan δ _peak , comprising the steps of: determining the above-mentioned polyurethane resin sheet based on the following formula (2) The equivalent ratio R of the active hydrogen group present in the hardener (D) to the isocyanate group present at the end of the polyurethane bond-containing isocyanate compound (A) as a prepolymer, which is used as a prepolymer The isocyanate compound (A) containing a polyurethane bond is obtained by reacting a polyisocyanate compound (B) with a high molecular weight polyol having a number average molecular weight of Mn; and is equivalent to the above formula (2) The isocyanate compound (A) and the hardener (D) containing a polyurethane bond as a prepolymer are prepared in a ratio of R; at least a polyurethane bond-containing isocyanate compound as a prepolymer is prepared ( A) a mixture of the molding agent and the mixture of the curing agent (D), and a polyurethane resin molded article obtained by molding the mixed body for forming the molded body to obtain a polyurethane resin sheet; The above tan δ is utilized Of 10 rad / sec and a dynamic viscoelasticity test of tensile mode by measurement of the loss elastic modulus E "with respect to the storage elastic modulus E 'of the _{ratio: tanδ peak = C (R +} 1) ( wherein, C is The value of the following formula (3) is satisfied) (2) 1.2 × 10 ^-7 × Mn ^{2 -} 3.6 × 10 ^-4 × Mn + 0.29 < C < 1.2 × 10 ^-7 × Mn ^{2 -} 3.6 × 10 ^{- 4} × Mn +0.31 (3). The method of claim 7, wherein the polyisocyanate compound (B) is 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate; and the above polyol compound (C) is poly(oxytetramethylene). a diol; and the above hardener (D) is 3,3'-dichloro-4,4'-diaminodiphenylmethane. The method of claim 8, wherein the number average molecular weight Mn of the poly(oxytetramethylene) glycol is in the range of from 600 to 2,500.