JPH11322878A - Production of foamed polyurethane molded product, urethane resin composition for producing the same and abrasive pad using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a foamed polyurethane molded product for abrasive pads enabling silicon wafers for semiconductors to be flattened efficiently in high accuracy, and to obtain an abrasive pad using the above molded product. SOLUTION: This method for producing a foamed polyurethane molded product comprises the following procedure: when two solutions respectively containing (a) an isocyanate-terminated prepolymer and (b) an active hydrogen- contg. compound are to be mixed with each other to conduct a reaction between the components (a) and (b) to effect curing, (c) (un)expanded polystyrene-based beads are previously admixed in the component (a) or (b), and the unexpanded beads (c) are subjected to microexpansion by the aid of the heat of reaction released in the above-mentioned reaction and curing and by external heating, or the expanded beads (c) are simply dispersed in the resulting molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a foam-containing polyurethane molded article for producing a polishing pad excellent in polishing characteristics and flatness of a semiconductor wafer, a urethane resin composition thereof, and a polishing pad using the same. Things.

[0002]

2. Description of the Related Art Conventionally, polyurethane resins have excellent mechanical strength and elasticity, so they have been used for coating agents, molding materials, synthetic leather, surface treatment agents, paints, adhesives, films, etc., and as heat insulating foams. It is used for materials and abrasives.

[0003] Among them, for abrasives, they are used as abrasive cloth binders, pressure-loading materials (wrapping materials), grindstone materials and cushioning materials (backup materials). Depending on the application, a porous material or a microfoamed casting material formed by wet film formation is used.

Further, with the rapid development of the information industry in recent years, the demand for LSIs used in personal computers and the like has been rapidly increasing, and there has been a demand for large-capacity LSIs, multilayer wiring, and high-speed LSIs. Therefore, advanced LSI planarization technology is indispensable, but conventional planarization technology such as etching is insufficient, and CMP (Chemical Mechanical Polishing) is not sufficient.
A chemical-mechanical polishing method called the method is already being applied extensively in the United States.

The polishing pad used in the CMP method is a finely-foamed polyurethane resin, and many patents have been filed, mainly in Japanese Patent Application Laid-Open No. 08-500622. According to the patent publication, the microfoamed polyurethane is made of a polymer impregnated with a polymer microelement having a plurality of flexible void spaces, and the polymer microelement is made of a water-soluble polymer or polyurethane. ing. However, these have some problems in flatness as a polishing pad.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a foam-containing polyurethane molded article having excellent flatness and polishing properties as a polishing pad for a CMP method, and an object of the polishing pad.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve these objects, and as a result, have found a production method using a specific composition containing specific beads, and have completed the present invention. Was.

That is, the present invention relates to a method of mixing (a) an isocyanate-terminated prepolymer and (b) an active hydrogen-containing compound in a two-part mixture and stirring and curing the mixture. The non-foamed polystyrene beads (c) are added and mixed in advance with at least one of the isocyanate-terminated prepolymer or (b) the active hydrogen-containing compound, and the reaction heat released during the two-component reaction curing and external heating are used to form the unexpanded polystyrene beads (c). A method for producing a foam-containing polyurethane molded product, which comprises finely foaming or simply dispersing foamed polystyrene beads (c), wherein the polystyrene beads (c) are composed of 50% by weight or more of a styrene monomer component. Hard polystyrene type, preferably the polystyrene type beads (c) are about 150 μm or less in the molded product. Be those having an average particle size, preferably unfoamed polystyrene beads (c)
Is that the foaming agent is impregnated inside, preferably isocyanate terminated prepolymer (a), active hydrogen containing compound (b), and unfoamed polystyrene beads (c)
Composed of the polystyrene-based beads by heat (c)
It is intended to provide a polishing pad comprising a urethane resin composition for a finely foamed molded product and a foam-containing polyurethane molded product as a main component, characterized by foaming a foam.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The isocyanate-terminated prepolymer (a) used in the present invention comprises a diisocyanate (a-1) and a high molecular polyol (preferably a number average molecular weight of 400 to 60).
00) (a-2) and a low molecular polyol (also referred to as a chain extender, preferably having a number average molecular weight of less than 400) (a-3), and a high molecular polyol (a-2) component and a low molecular polyol (a-
3) It is obtained by reacting an isocyanate (a-1) component (NCO component) with an equivalent excess of the mixed polyol (OH component) with the component. For casting, it is necessary to have a melt viscosity that can be operated at the casting temperature. Therefore, each component is appropriately selected within a range in which the produced prepolymer satisfies this condition.

[0010] The ratio of NCO / OH varies depending on the molecular weight and the like required of the polyurethane resin finally obtained. Further, a high molecular polyol (a-2) and a low molecular polyol (a-
The use ratio of 3) is determined within a range that satisfies the mechanical properties required for the finally obtained polyurethane resin and the melt viscosity that allows casting.

The isocyanate used in the present invention
Examples of the component (a-1) include a diisocyanate represented by the formula: R (NCO) ₂ (where R is an arbitrary divalent organic group). This isocyanate component is appropriately selected according to the pot life required at the time of casting, and it is necessary that the terminal NCO prepolymer to be formed has a low melt viscosity. Applied in a mixture.

Specific examples thereof include, but are not limited to, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, and cyclohexane-1,3- And 1,4-diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (= isophorone diisocyanate), bis- (4-isocyanatocyclohexyl) methane (= water MDI), 2- and 4
-Isocyanatocyclohexyl-2'-isocyanatocyclohexylmethane, 1,3- and 1,4-bis- (isocyanatomethyl) -cyclohexane, bis- (4-isocyanato-3-methylcyclohexyl) methane, 1,
3- and 1,4-tetramethylxylidene diisocyanate, 2,4- and / or 2,6-diisocyanatotoluene, 2,2'-, 2,4'- and / or 4,4 '
-Diisocyanatodiphenylmethane, 1,5-naphthalenediisocyanate, p- and m-phenylenediisocyanate, dimeryl diisocyanate, xylylene diisocyanate, diphenyl-4,4 ' -Diisocine-
And the like.

The high molecular weight polyol (a-2) includes, for example, hydroxy-terminated polyester, polycarbonate,
Polyester carbonates, polyethers, polyether carbonates, polyester amides and the like are listed. Of these, polyethers and polycarbonates having good hydrolysis resistance are preferable, and the price is low. Polyether is particularly preferred from the viewpoint of surface and melt viscosity.

The polyetherpolyol includes a starting compound having a reactive hydrogen atom, for example, ethylene oxide,
Examples include alkylene oxides such as propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, and epichlorohydrin, or reaction products with a mixture of these alkylene oxides.

Starting compounds having a reactive hydrogen atom include water, bisphenol A and polyester polyols.
And the above-mentioned divalent alcohols for producing alcohols. Examples of the polycarbonate having a hydroxy group include 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, and polypropylene. Diols such as glycol and / or polytetramethylene glycol and phosgene, diallyl carbonate (eg, diphenyl carbonate) or cyclic carbonate (eg, propylene carbonate) G).

Examples of the polyester polyol include a reaction product of a divalent alcohol and a dibasic carboxylic acid. In order to improve hydrolysis resistance, it is preferable that the distance between ester bonds is long. In any case, a combination of long chain components is desirable.

The divalent alcohol is not particularly restricted but includes, for example, ethylene glycol, 1,3- and 1,2.
-Propylene glycol, 1,4- and 1,3- and 2,3-butylene glycol, 1,6-hexane glycol, 1,8-octanediol, neopentyl glycol, cyclohexanediol Methanol, 1,4-bis-
(Hydroxymethyl) -cyclohexane, 2-methyl-
1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, diethylene glycol, dipropylene glycol, triethylene glycol, Tripropylene glycol, dibutylene glycol and the like.

As the dibasic carboxylic acid, there are aliphatic, alicyclic, aromatic and / or heterocyclic ones. From the viewpoint of necessitating a liquid or low melt viscosity of the resulting terminal NCO prepolymer, Aliphatic or alicyclic ones are preferable, and when an aromatic type is used, it is preferable to use them together with aliphatic or alicyclic ones.

Examples of the carboxylic acid include, but are not limited to, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid (o-, m-, p-), dimer-fatty acids, such as oleic acid.

These polyester polyols may partially have a carboxyl group at the terminal. For example,
Lactones such as ε-caprolactone or hydroxycarboxylic acids such as ε-hydroxycaproic acid can also be used.

Examples of the low molecular weight polyol include the divalent alcohol used for producing the above-mentioned polyester polyol.

As the low-molecular polyol (a-3), a short-chain glycol is used.
-Propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-
Butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol and the like can be used.

Isocyanate-terminated urethane prepolymer
The production conditions of (a) are not particularly limited, but are preferably at 60 to 100 ° C, particularly preferably at 60 to 80 ° C, without solvent, using these polyurethane raw materials without a catalyst or a known urethanization catalyst. Or by adding a reaction retarder and stirring and mixing. Further, the NCO / OH equivalent ratio depends on the type of isocyanate, but preferably 1.2 to 5.0 is used.

On the other hand, as the active hydrogen-containing compound (b) used in the present invention, an organic diamine compound is mainly used because of its reactivity. If necessary, poly (oxytetramethylene) glycol and poly (oxypropylene) may be used. ) Polyether polyols such as glycols, polycarbonate polyols, polyester polyols and the like can be used in combination. However, the polyols used in combination preferably have a low molecular weight in the range of 400 to 1,000.

The organic diamine compound used includes:
For example, 3,3′-dichloro-4,4′-diaminodiphenylmethane, chloroaniline-modified dichlorodiaminodiphenylmethane, 1,2-bis (2-aminophenylthio) ethane, trimethylene glycol di-p-aminobenzoate, 5-bis (methylthio) -2,6-toluenediamine and the like.

According to the present invention, the compounding ratio of the isocyanate-terminated urethane prepolymer (a) and the active hydrogen-containing compound (b), that is, the organic diamine compound (b), in the two-pack casting is different. Is determined by the molar ratio between the isocyanate groups and the amino groups. The ratio is NH ₂
It is preferable that /NCO=0.7 to 1.2. Particularly, a range of 0.8 to 1.0 is preferably applied. When the active hydrogen-containing compound (b) is a mixture of a diamine and a polyol, the isocyanate group of the isocyanate-terminated prepolymer (a) and the active hydrogen-containing compound
The hydroxyl group of the polyol in (b) is determined by the molar ratio of the excess isocyanate group and the amino group of the organic diamine compound in the active hydrogen-containing compound (b) when it is assumed that the hydroxyl group has reacted at 1: 1. , And the same as the above NH ₂ / NCO ratio.

The polystyrene-based beads (c) used in the present invention are either spherical (granular) unfoamed or foamed (including prefoamed ones), and the inside is made of polystyrene. . The unfoamed one is impregnated with a foaming agent for foaming during / immediately after the polymerization of polystyrene, and the foaming agent is contained in polystyrene beads. The expanded polystyrene-based beads are obtained by expanding polystyrene when a blowing agent is vaporized by heating, and have closed cells inside. The polystyrene-based beads (c) retain the polishing performance when the polyurethane molded product is applied to the polishing pad.
In particular, it is necessary to uniformly disperse them in a molded product. The blending amount of these polystyrene beads (c) is preferably in the range of 0.1 to 10 parts by weight based on 100 parts by weight of the isocyanate-terminated prepolymer (a) or the active hydrogen-containing compound (b). And particularly preferably 2 to 5 parts by weight.

The resin composition of the polystyrene beads (c) is preferably made of styrene in order to maintain durability as a polishing pad and to exhibit uniform polishing performance on the surface of the polishing pad. It is a hard type polystyrene composed of 50% by weight or more of the monomer, and preferably has an average particle size of 150 μm or less, particularly preferably 100 μm or less, in the finally obtained molded product.

The vinyl monomer to be copolymerized other than the styrene monomer constituting the polystyrene-based beads (c) of the present invention is not particularly limited. For example, acrylonitrile, methacrylonitrile, methyl methacrylate, acrylic acid, methacrylic acid, Fumaric acid, vinyl acetate, vinylidene chloride and the like. Further, in order to obtain beads having higher heat resistance, it is possible to use a required amount of a vinyl compound having two or more functionalities in combination. These compounds include, for example, divinylbenzene, ethylene glycol dimethacrylate, and the like.

The average particle size of the polystyrene beads (c) of the present invention is preferably 150 μm or less, particularly preferably 1 μm or less.
When the particle size is not more than 00 μm, it can be arbitrarily changed depending on the amount of the dispersant to be applied. When small particles are used, a large amount of the dispersant is used. The type of the dispersant is not particularly limited, but a water-soluble polymer compound, an inorganic dispersant, or the like is applied. The particle size of (c) is an unexpanded polystyrene bead (c).
In the case of (b), preferably 0.01 to 0.1 mm, in the case of expanded polystyrene beads (c),
5 to 0.2 mm.

The foaming agent for the polystyrene type beads (c) is not particularly limited. For example, hydrocarbons such as ethane, ethylene, propane, butane, butene, isobutene, neopentane, acetylene, hexane and heptane are preferably used. .

The method for producing the polystyrene-based beads (c) of the present invention is not particularly limited. For example, a suspension in which a hydrocarbon-based blowing agent and a catalyst are added to a styrene-based monomer and reacted in a polymerization vessel. Polymerization method, pelletized or spherical styrenic polymer and put into a pressure cooker with the dispersion solution,
A method in which a hydrocarbon foaming agent is mainly injected under pressure, and the foaming agent is permeated, impregnated, and dispersed in the polymer while stirring is used.

The casting conditions of the present invention include: an isocyanate-terminated prepolymer (a) or an active hydrogen-containing compound.
(b) Add to either one and mix, and polystyrene beads
The two-component mixture containing (c) is uniformly mixed, and the two-component mixture adjusted to a pot life in a defoamable range is preferably 70 to
After pouring into a mold maintained at 120 ° C. (more preferably 80 to 110 ° C.), preferably at 90 to 110 ° C., and then casting, preferably taking 0.2 to 2 hours, preferably 100 to 130 hours Primary cure at ° C. Next, after the molded product is released from the mold, it is more preferably 3 to 7 at 100 to 130 ° C.
Allow complete post-cure over time and cool to room temperature.

The temperature range of the isocyanate-terminated prepolymer (a) component and the active hydrogen-containing compound (b) component at the time of performing the curing reaction in the two-component molding machine is determined by circulating in the line of the two-component molding machine. The liquid fluidity of the degree that does not cause trouble is secured, and after mixing the two liquids, the unexpanded heat-expandable micro hollow sphere (c) has a balance between the exothermic behavior and the thickening behavior that can be foamed sufficiently. It is essential that it be reactive.
Specifically, the isocyanate-terminated prepolymer (a) component is preferably kept at a temperature in the range of 60 to 90 ° C, and particularly preferably used in the temperature range of 70 to 80 ° C.

In the present invention, a stabilizer such as an antioxidant, a lubricant, a pigment, a filler may be added to the composition comprising (a) + (b) + (c) at any time during the urethanization reaction, if necessary. , An antistatic agent and other additives can be added.

The foam-containing urethane molded product obtained in the present invention is not a foam of polyurethane itself, but a molded product of styrene-based beads (c) as a foam component, and may have any shape. In order to obtain a polishing pad, it is preferable to form a flat plate-shaped product, but since the material is stable, it is sliced in the horizontal direction with respect to the thickness, cut into a required thickness and cut into a required size in a thin plate shape. Manufacturing materials By using this, it is possible to obtain a polishing pad having no difference in density and hardness in any lot. The sliced thin plate-like polishing pad material obtained by the present invention is used as a polishing pad by forming a groove on the surface or backing the back surface with a soft porous sheet such as a nonwoven fabric.

In the production method of the present invention, the molding size is vertical:
1000 mm × width: range up 1000 mm × thickness 50 ^t mm are possible molding of microbubbles containing moldings. The density of the obtained fine foam-containing molded product is preferably 0.5 to 1.0 g.
/ Cm ³ and 0.7 to use as a polishing pad.
It is preferably in the range of 0.9 g / cm ^3. In addition, the hardness of the fine foam-containing molded product, the isocyanate-terminated prepolymer (a) to be used, the active hydrogen-containing compound (b), the type of unexpanded or expanded polystyrene-based beads (c), varies depending on the amount added, but is preferably Is (Shore D) = 40-6
5, and particularly preferably (Shore D) = 50 to 60.

[0038]

Next, embodiments of the present invention will be described with reference to specific examples, but the present invention is not limited to these examples. Parts and percentages in the examples are by weight unless otherwise indicated.

(Method of Evaluating Polishing Characteristics) Polishing rate A polishing test is performed for 1 minute, and the thickness of the object to be polished before and after the test is measured. The measurement positions are determined in advance at 50 locations within the polishing surface. The average value of the thickness difference before and after the polishing test at 50 measurement positions is calculated, and the average value is defined as the polishing rate for one polishing pad.

The average value A and the dispersion value B of the polishing rate for 10 polishing pads sliced from the same foam-containing urethane molded product are represented by A ± B, and the polishing characteristics and lot-to-lot fluctuation are evaluated. A relates to the polishing characteristics, and the larger the numerical value, the better the polishing efficiency. B relates to lot-to-lot fluctuation, and the smaller the numerical value, the more stable the polishing characteristics.

2. Flatness A polishing test is performed for 1 minute, and the thickness of the object to be polished before and after the test is measured. The measurement positions are determined in advance at 50 locations within the polishing surface. From the maximum value (Max), the minimum value (Min), and the average value (Ave) of the difference in thickness before and after the polishing test at the 50 measurement positions, the flatness of one polishing pad is calculated by the following equation.

(Flatness = 100 × (Max−Min) / Ave) The average value C and the variance value D of the flatness values of 10 polishing pads sliced from the same urethane molded product containing fine bubbles are represented by C ±.
This is represented by D, and the polishing characteristics and lot-to-lot fluctuation are evaluated. C relates to the polishing characteristics, and the smaller the numerical value, the more excellent the flatness of the polished surface. D relates to lot-to-lot fluctuation, and a smaller value indicates that the polishing characteristics are more stable.

Reference Example 1 Production of polystyrene beads-1 (production of unexpanded beads) In an autoclave, 6 parts of tribasic calcium phosphate and sodium dodecylbenzenesulfonate were added as suspension stabilizers.
And a solution obtained by dissolving 0.25 part of benzoyl peroxide and 0.05 part of tert-butyl perbenzoate as a catalyst in a monomer mixture consisting of 95 parts of styrene monomer and 5 parts of acrylonitrile monomer. , Α-pinene completely hydrogenated homopolymer (“Clearon P-125” manufactured by Yashara Chemical Co., Ltd.)
2.0 parts, and polymerization was carried out at 85 ° C.
At 0%, 2 parts of tertiary calcium phosphate were added, and 8.5 parts of butane and 1.5 parts of cyclohexane as a blowing agent were injected under pressure, and the temperature was raised to complete the polymerization at 115 ° C. I let it. Next, the beads generated after cooling the contents were taken out, dehydrated, dried and classified to obtain a particle diameter of 0.0.
Expandable polystyrene beads having a size of 2 to 0.07 mm were obtained.

Reference Example 2 Production of polystyrene beads-2 (production of expanded beads) In an autoclave, 8 parts of tribasic calcium phosphate and sodium dodecylbenzenesulfonate were added as suspension stabilizers.
A mixture of 0.05 part of deionized water and 0.20 part of benzoyl peroxide and 0.05 part of tert-butyl perbenzoate as a catalyst are composed of 90 parts of styrene monomer, 10 parts of acrylonitrile monomer and 0.05 part of divinylbenzene. A solution dissolved in the monomer mixture,
2.0 parts of a completely hydrogenated homopolymer of α-pinene (“Clearon P-125” manufactured by Yasuhara Chemical Co., Ltd.) was charged, and 8
Polymerization was carried out at 5 ° C., and when the polymerization rate reached 90%, 2 parts of tertiary calcium phosphate was added, and 5 parts of butane as a blowing agent and 2 parts of cyclohexane were further injected, followed by heating. The polymerization was completed at 115 ° C. Next, the beads generated after cooling the contents were taken out, dehydrated, dried and classified to obtain polystyrene beads having a particle diameter of 0.010.05 mm. Next, the beads were coated with 500 ppm of dimethyl silicon and 2000 ppm of zinc stearate in order to prevent agglomeration during the prefoaming of the beads, and then the resin particles were heated to about 95 ° C. with steam to obtain a particle size of 0.07 to 0.15
mm expanded particles and then aged for 24 hours.

Reference Example 3 Production of Polystyrene Beads-3 (Production of Unexpanded Beads) In an autoclave, 4 parts of tribasic calcium phosphate and sodium dodecylbenzenesulfonate were added as suspension stabilizers.
And a solution obtained by dissolving 0.25 part of benzoyl peroxide and 0.05 part of tert-butyl perbenzoate as a catalyst in a monomer mixture consisting of 95 parts of styrene monomer and 5 parts of acrylonitrile monomer. , Α-pinene completely hydrogenated homopolymer (“Clearon P-125” manufactured by Yashara Chemical Co., Ltd.)
2.0 parts, and polymerization was carried out at 85 ° C.
At 0%, 2 parts of tertiary calcium phosphate were added, and 8.5 parts of butane and 1.5 parts of cyclohexane as a blowing agent were injected under pressure, and the temperature was raised to complete the polymerization at 115 ° C. I let it. Next, the beads generated after cooling the contents were taken out, dehydrated, dried and classified to obtain a particle diameter of 0.0.
Expandable polystyrene beads having a size of 5 to 0.10 mm were obtained.

Reference Example 4 Production of Polystyrene Beads-4 (Production of Expanded Beads) In an autoclave, 8 parts of tribasic calcium phosphate and sodium dodecylbenzenesulfonate were added as suspension stabilizers.
And a solution obtained by dissolving 0.25 part of benzoyl peroxide and 0.05 part of tert-butyl perbenzoate as a catalyst in a monomer mixture consisting of 90 parts of styrene monomer and 10 parts of acrylonitrile monomer. , Α-pinene completely hydrogenated homopolymer (“Clearon P-125” manufactured by Yashara Chemical Co., Ltd.)
2.0 parts, and polymerization was carried out at 85 ° C.
At 0%, 2 parts of tertiary calcium phosphate were added, and 5 parts of butane as a blowing agent and 2 parts of cyclohexane were added.
Then, the temperature was raised and the polymerization was completed at 115 ° C. Next, the beads generated after cooling the contents are taken out, dehydrated, dried, and classified to obtain a particle diameter of 0.01 to 0.0.
5 mm polystyrene beads were obtained. Next, 500 ppm of dimethyl silicon and 2,000 pp of zinc stearate were added to the beads to prevent agglomeration during the prefoaming of the beads.
After coating with m, the resin particles were heated to 80 ° C. with steam to form expanded particles having a particle size of 0.07 to 0.15 mm, and then aged for 24 hours.

[Reference Examples 5 to 7] Various polystyrene beads were produced in the same manner as in Reference Examples 1 to 4, while appropriately changing the reaction conditions. (Polystyrene beads-5
6) Table 1 summarizes the production conditions and particle diameters of the produced beads.

[0048]

[Table 1] Note: St = Styrene, AN = Acrylonitrile, DVB = Silidine benzene Particle size: Shown by unfoamed or foamed final size. * Indicates foamed.

Example 1 Polyoxytetramethylene glycol (MW = 1000), diethylene glycol,
Isocyanate-terminated prepolymer composed of 2,6-tolylene diisocyanate (NC0 equivalent = 600) 1
To 000 parts, a compound obtained by adding and mixing 40 parts of the polystyrene beads obtained in Reference Example 1 and 211 parts of 3,3′-dichloro-4,4′-diaminodiphenylmethane were added.
Each is charged into the A liquid tank and the B liquid tank of the elastomer casting machine. The A liquid system was operated at 70 ° C. and the B liquid system was operated at 120 ° C.
After injecting it into a mold at ℃, close the mold and further in an oven for 30 minutes.
Heated to 110 ° C for 1 minute and primary cured. After demolding, the ingot was secondarily cured at 120 ° C. for 5 hours. 25 ingots
After allowing to cool to ℃, it was sliced to a thickness of 1.5 mm to form a polishing pad. The specific gravity of the ingot is 0.8
1. The hardness was Shore-D54.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the polishing conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1850 ± 20 Å / min, and the flatness was 7 ± 2%.

Example 2 The same isocyanate-terminated prepolymer as in Example 1 (NCO equivalent = 600) 1000
And a compound obtained by adding 167 parts of 3,5-bis (methylthio) -2,6-toluenediamine to 38 parts of the polystyrene beads obtained in Reference Example 1 and mixing them, respectively. Charge the liquid tank. The liquid A system is operated at 80 ° C., and the liquid B system is operated at 50 ° C. After the resin mixed in the two liquids is injected into a mold having a mold temperature of 100 ° C. by a mixing head, the mold is closed, and the mixture is further heated in an oven for 30 minutes.
Heated to ° C and primary cured. After removing the ingot, 120
Secondary cured at 5 ° C. for 5 hours. The ingot was allowed to cool to 25 ° C., and then sliced to a thickness of 1.5 mm to form a polishing pad. The specific gravity of the ingot was 0.80 and the hardness was Shore-D55.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1900 ± 20 Å / min, and the flatness was 5 ± 1%.

Example 3 The procedure of Example 1 was repeated except that 25 parts of the polystyrene beads obtained in Reference Example 2 were used instead of using 40 parts of the polystyrene beads obtained in Reference Example 1. A polishing pad was formed in the same manner as in Example 1. The specific gravity of the obtained ingot was 0.83 and the hardness was Shore-D56.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1800 ± 20 Å / min, and the flatness was 6 ± 2%.

Example 4 The procedure of Example 2 was repeated except that 25 parts of the polystyrene beads obtained in Reference Example 2 were used instead of 40 parts of the polystyrene beads obtained in Reference Example 1. A polishing pad was formed in the same manner as in Example 2. The specific gravity of the obtained ingot was 0.80 and the hardness was Shore-D55.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the polishing conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1850 ± 20 Å / min, and the flatness was 7 ± 2%.

Example 5 Polyoxytetramethylene glycol (MW = 1000), diethylene glycol,
Isocyanate-terminated copolymer composed of 2,6-tolylene diisocyanate (NC0 equivalent = 450) 10
The polystyrene beads 4 obtained in Reference Example 1 were added to 00 parts.
0: 1 part of a compound mixed with 3,5-bis (methylthio) -2,6-toluenediamine / polyoxytetramethylene glycol (MW = 650) 4
32 parts are charged to the A liquid tank and the B liquid tank of the elastomer casting machine, respectively. A liquid system is 80 ° C, B liquid system is 50 ° C.
The mixture was operated at a temperature of 100.degree. C., and after mixing the two-component resin with a mixing head into a mold having a mold temperature of 100.degree. C., the mold was closed. After demolding, the ingot was secondarily cured at 120 ° C. for 5 hours. The ingot was allowed to cool to 25 ° C., and then sliced to a thickness of 1.5 mm to form a polishing pad. The specific gravity of the obtained ingot was 0.82 and the hardness was Shore-D57.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1900 ± 20 Å / min, and the flatness was 7 ± 2%.

Example 6 The procedure of Example 1 was repeated except that 40 parts of the polystyrene beads obtained in Reference Example 3 were used instead of 40 parts of the polystyrene beads obtained in Reference Example 1. A polishing pad was formed in the same manner as in Example 1. The specific gravity of the obtained ingot was 0.80 and the hardness was Shore-D54.

10 polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1860 ± 20 angstroms / min, and the flatness was 6 ± 2%.

Example 7 The procedure of Example 2 was repeated, except that 25 parts of the polystyrene beads obtained in Reference Example 4 were used instead of 40 parts of the polystyrene beads obtained in Reference Example 1. A polishing pad was formed in the same manner as in Example 2. The specific gravity of the obtained ingot was 0.81 and the hardness was Shore-D55.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the polishing conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1890 ± 20 Å / min, and the flatness was 7 ± 2%.

Example 8 The procedure of Example 1 was repeated except that 40 parts of the polystyrene beads obtained in Reference Example 5 were used instead of 40 parts of the polystyrene beads obtained in Reference Example 1. A polishing pad was formed in the same manner as in Example 1. The specific gravity of the obtained ingot was 0.82 and the hardness was Shore-D54.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the polishing conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1850 ± 20 angstrom / min, and the flatness was 8 ± 2%.

Comparative Example 1 In Example 3, 25 parts of EXPANCEL-551DE (polyacrylonitrile / polyvinylidene chloride-based foamed balloon) was used instead of adding and mixing 25 parts of the polystyrene beads obtained in Reference Example 1. A polishing pad was formed in exactly the same manner as in Example 3 except that the polishing pad was used. The specific gravity of the obtained ingot was 0.80,
The hardness was Shore-D54.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the polishing conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1850 ± 70 Å / min, and the flatness was 10 ± 5%.

Comparative Example 2 The procedure of Example 2 was repeated except that 32 parts of partially acetylated polyvinyl alcohol powder was used instead of adding and mixing 40 parts of the polystyrene beads obtained in Reference Example 1. In exactly the same way as in Example 2,
A polishing pad was formed. The specific gravity of the obtained ingot was 0.79 and the hardness was Shore-D53.

Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO 2 film were measured. A polishing test was performed under the conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1800 ± 60 Å / min, and the flatness was 10 ± 5%.

Comparative Example 3 The procedure of Example 1 was repeated except that 40 parts of the polystyrene beads obtained in Reference Example 6 were used instead of 40 parts of the polystyrene beads obtained in Reference Example 1. A polishing pad was formed in the same manner as in Example 1. The specific gravity of the obtained ingot was 0.80 and the hardness was Shore-D54. Ten polishing pads thus obtained were mounted on a polishing apparatus, and the polishing characteristics of the SiO2 film were measured. A polishing test was performed under the polishing conditions of a wafer load of 5.0 psi, a platen rotation speed of 280 rpm, and a polishing time of 60 seconds. As a result, the polishing rate was 1810 ± 70 angstroms / min and the flatness was 12 ± 5%.

The physical properties obtained in Examples and Comparative Examples were
The results are shown in Table 2. It is apparent from this that a polyurethane molding obtained by the production method according to the specific composition of the present invention is sliced to obtain a polishing pad excellent in CMP polishing characteristics and flatness.

[0071]

[Table 2]

* P-1: PTMG (MW = 1000) / DEG / TDI (NC0 equivalent = 600) P-2: PTMG (MW = 1000) / DEG / TDI (NC0 equivalent = 450) V-1: 3, 3'-dichloro-4,4'-diaminodiphenylmethane V-2: 3,5-bis (methylthio) -2,6-toluenediamine V-3: 3,5-bis (methylthio) -2,6-toluenediamine / PTMG (MW = 650) = 1/1

[0073]

The microfoamed polyurethane molded article obtained by the method for producing a microfoamed polyurethane molded article of the present invention has excellent CMP polishing characteristics and flatness when sliced and used as a polishing pad. A polishing pad can be provided.

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI C08J 9/32 C08J 9/32 C08K 7/22 C08K 7/22 C08L 25/04 C08L 25/04 75/04 75/04 // C08J 5/14 CFF C08J 5/14 CFF (C08G 18/10 101: 00)

Claims (6)

[Claims] When mixing (a) an isocyanate-terminated prepolymer and (b) an active hydrogen-containing compound in two liquids and stirring and reacting and curing the mixture, (c) unfoamed or foamed polystyrene beads are mixed with (a) an isocyanate-terminated prepolymer. Or (b) non-foamed polystyrene beads added and mixed in advance with at least one of the active hydrogen-containing compounds, and the reaction heat released during the two-component reaction curing and external heating.
A method for producing a foam-containing polyurethane molded product, wherein (c) is finely foamed or foamed polystyrene beads (c) are simply dispersed. 2. The method for producing a foam-containing polyurethane molded article according to claim 1, wherein the polystyrene-based beads (c) are of a hard polystyrene type composed of 50% by weight or more of a styrene monomer component. 3. The method for producing a foam-containing polyurethane molded article according to claim 1, wherein the polystyrene-based beads (c) have an average particle size of about 150 μm or less in the molded article. 4. Unexpanded polystyrene beads (c)
The method for producing a foam-containing polyurethane molded product according to any one of claims 1 to 3, wherein the resin has a foaming agent impregnated therein. 5. An isocyanate-terminated prepolymer (a),
A urethane resin composition for a foam-containing molded article, comprising an active hydrogen-containing compound (b) and unexpanded polystyrene beads (c), wherein the polystyrene beads (c) are expanded by heat. 6. A polishing pad comprising the foam-containing polyurethane molded product according to claim 1 as a main component.