JPH11322877A - Production of microporous molded product and urethane resin composition for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a microporous urethane molded product for obtaining abrasive pads capable of efficiently and accurately flattening the wiring-forming surface of a semiconductor substrate with no interlot variance in abrasion efficiency and abraded surface flatness. SOLUTION: This method for producing a microporous urthane 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, (c) unexpanded thermally expandable microballoons as expandable agent is previously admixed in the component (a) or (b), and the microballoons (c) are subjected to microexpansion in a urethane molded product by the aid of the heat of reaction released in the reaction between the two solutions to effect curing and by external heating, thereby including the resulting thermally expanded microballoons (c) in the final molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a microbubble-containing urethane molded article for a polishing pad, which has no fluctuation in polishing characteristics between lots, has excellent polishing characteristics, and has a high degree of flatness, and a resin composition thereof. It is about.

[0002]

2. Description of the Related Art In recent years, with the rapid increase in the degree of integration of semiconductor elements, the density of wiring patterns has been increasing, and it has become impossible to cover them only by improving the exposure technique when transferring patterns. In addition, the high lamination also amplifies the unevenness of the surface of the semiconductor substrate, so that it is difficult to draw a precise wiring, and the necessity of a technique for flattening the substrate surface is increasing. Conventional flattening methods include reflow and SOG (SIPN ON GLASS)
However, these methods have a drawback that it is difficult to planarize over a wide area. Therefore, recently, a polishing method combining a chemical action and a mechanical action on a wafer surface, which is a semiconductor substrate, and a CMP (Chemical Mechanical Polishing) method have been adopted.

The polishing apparatus for CMP mainly comprises a platen, a wafer carrier, a polishing slurry supply port, and a diamond dresser. A polishing pad is placed on a platen, and a semiconductor substrate is placed on a wafer carrier. Polishing by the CMP method applies a load to the wafer carrier on the polishing pad, rotates the platen at the same time, continuously supplies the polishing slurry onto the polishing pad, and contacts the polishing pad and the semiconductor substrate via the polishing slurry. It is done by doing. At this time, the polishing pad is conditioned by a diamond dresser to remove polishing debris, and at the same time, to give a fluff to the surface, so that a new polishing surface can always be supplied. Polishing slurries typically contain colloidal silica of about 10 to 20%, KOH or NH ₄ O
The silica particles are used to adjust the pH to about 10 to 11 using H or the like, and the silica particles give a mechanical action and the alkaline solution gives a chemical action.

The polishing pad used in the CMP method includes a porous nonwoven fabric type in which a nonwoven fabric is impregnated with polyurethane and a foaming type made of foamed polyurethane. In each case,
It has a structure with pores on the surface, and has a function of holding the supplied polishing slurry.

[0005] However, the non-woven fabric type described in, for example, JP-A-64-058475 and JP-A-2-250776 employs a method in which a polyurethane / DMF solution is impregnated into the nonwoven fabric and then wet-cured. Being manufactured. The polishing pad obtained by this manufacturing method has good contact with the semiconductor substrate during polishing and good holding property of the polishing slurry, but has a disadvantage that the surface is insufficiently compressed and easily deformed, resulting in poor flatness of the semiconductor substrate. There is.

On the other hand, in the foaming type described in Japanese Patent Application Laid-Open No. 8-500622, an isocyanate-terminated prepolymer and 3,3'-dichloro-4,4'-diaminodiphenylmethane are mixed and stirred to react. It is made of a resin composition in which expanded hollow microspheres are added and mixed at the time of curing, and is manufactured by a method of slicing a molded ingot into 1.5 mm. Since the polishing pad obtained by this method has a high surface hardness of about Shore D55, compression deformation is less likely to occur than the nonwoven fabric type, and the polishing rate and flatness are good.

However, when the expanded micro hollow body is mixed with the isocyanate-terminated prepolymer, the viscosity is extremely high.
When mixed and stirred with 3,3'-dichloro-4,4'-diaminodiphenylmethane, foaming easily occurs and air voids are easily generated in the molded product. In addition, since the expanded micro hollow spheres have a specific gravity of 0.042 ± 0.004, which is a large difference in specific gravity from the isocyanate-terminated prepolymer, the compound obtained by blending them is easily separated, and the dispersed state of the expanded micro hollow spheres is unstable.

Therefore, for example, when urethane molding containing fine bubbles is carried out by a two-component molding machine, the injection liquid discharged from the head is liable to be mixed, so that a batch production method must be selected, and the productivity must be increased. Does not improve. Further, the compound and 3,3'-dichloro-4,4 '
When the injection liquid mixed and stirred with diaminodiphenylmethane is injected into a mold and molded, the expanded hollow microspheres float and are unevenly distributed in the upper surface direction until the resin hardens. Therefore, the polishing pad obtained by slicing a molded product in the horizontal direction has a difference in density and hardness between the upper surface and the lower surface, so that the material is not stable, and the polishing characteristics vary greatly between lots of the polishing pad. was there.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to improve the productivity by enabling the formation of urethane containing fine bubbles using a two-component molding machine by stabilizing the dispersion state of hollow microspheres in a compound. Another object of the present invention is to stabilize the material of the polishing pad by making the cell size of the molded product and the dispersion state of the cells uniform, to eliminate the fluctuation of the polishing characteristics between lots of the polishing pad, and to improve the polishing characteristics.

[0010]

Means for Solving the Problems The present inventors have made intensive studies to achieve these objects, and as a result, have found a method for producing a urethane molded article containing a fine bubble containing a specific heat-expandable fine hollow body. Thus, the present invention has been completed.

That is, in the present invention, when the two liquids of the isocyanate-terminated prepolymer (a) and the active hydrogen-containing compound (b) are mixed and stirred, an unfoamed, heat-expandable micro hollow sphere (c) is used as a foaming factor. Pre-added to at least one of the terminal prepolymer (a) or the active hydrogen-containing compound (b) and mixed in advance. The method for producing a microbubble-containing urethane molded article, characterized in that the hollow sphere (c) is microfoamed in a urethane molded article and the molded article contains the heat-expandable micro hollow sphere (c), preferably active The hydrogen-containing compound (b) is a mixture of a polyol and a liquid polyamine, and is a liquid at ordinary temperature, preferably, the active hydrogen-containing compound (b) is a bis (alkylthio) aromatic diamine at a normal temperature. And, preferably, an unfoamed heat-expandable micro hollow sphere (c), which contains a low-boiling hydrocarbon in the hollow portion, and the shell portion is composed of an acrylonitrile-vinylidene chloride copolymer or an acrylonitrile-methyl methacrylate copolymer. The heat expansion start temperature is in the range of 70 to 120 ° C., preferably an isocyanate-terminated prepolymer (a), an active hydrogen-containing compound (b), and an unfoamed heat expandable micro hollow sphere
(c), heat-expandable micro hollow sphere composed of heat
Provided is a urethane resin composition for a molded article containing fine bubbles, characterized by foaming (c).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The isocyanate-terminated prepolymer (a) used in the present invention is a reaction product of a diisocyanate (a-1), a polyol (a-2) and a chain extender (a-3).

As the diisocyanate (a-1), 2,4-tolylene diisocyanate is mainly used, but other diisocyanates can be used in combination as long as the effects of the present invention are not impaired. Is 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthalene-1,5-diisocyanate,
Compounds such as trizine diisocyanate, paraphenylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like can be given, but not limited thereto.

As the polyol (a-2), for example, polyether polyols such as poly (oxytetramethylene) glycol and poly (oxypropylene) glycol, polycarbonate polyols and polyester polyols can be used.

As the chain extender (a-3), use is made of short-chain glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol,
2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentane Diol, 1,6
-Hexanediol, diethylene glycol, dipropylene glycol and the like can be used.

Examples of the active hydrogen-containing compound (b) include 3,3'-dichloro-4,4'-diaminodiphenylmethane, chloroaniline-modified dichlorodiaminodiphenylmethane, and 3,5-bis (methylthio) -2,4-toluene. At least one of diamines such as diamine and 3,5-bis (methylthio) -2,6-toluenediamine is mainly used. These diamines function as a crosslinking agent for the isocyanate-terminated prepolymer (a). These diamines can be used alone, but if necessary, can be used in combination with polyether polyols such as poly (oxytetramethylene) glycol and poly (oxypropylene) glycol, polycarbonate polyols, polyester polyols and the like. is there. The molecular weight of the polyol used in combination with the amine is suitably low, and in particular, poly (oxytetramethylene) glycol having a molecular weight in the range of 500 to 1,000 is preferable.

The non-foamed heat-expandable micro hollow sphere (c) is preferably a micro hollow sphere in which a low boiling point hydrocarbon is contained in a hollow portion and a shell portion is made of a thermoplastic resin, and forms a shell. It is preferable that the softening temperature of the thermoplastic resin is higher than the boiling point of the included low-boiling hydrocarbon. Therefore,
When heat above the softening temperature of the shell thermoplastic resin is applied,
The softening of the thermoplastic resin and the volume expansion of the low-boiling hydrocarbon occur simultaneously, and the hollow microspheres have the property of expanding. Its softening temperature is preferably in the range of 70 to 120C, more preferably 80 to 110C.

The particle diameter of the non-foamed heat-expandable micro hollow sphere (c) is preferably 5 to 30 μm. As described above, since it is small when not foamed, as an advantage, the viscosity of the compound when mixed with the isocyanate-terminated prepolymer (A) can be kept low, and is generated by foaming during mixing and stirring with the active hydrogen compound. Air voids can be eliminated. The micro hollow sphere (c) foams during the two-liquid reaction curing, and preferably has a particle size of 10 to 100 μm after foaming.
Exists in the molded product as microbubbles.

Also, an unfoamed heat-expandable micro hollow sphere (c)
The true specific gravity of the isocyanate is preferably 1.0 to 1.1, and taking this range is close to the specific gravity of the isocyanate-terminated prepolymer, so that a good dispersion state can be maintained without fear of separation during mixing. Therefore, even when a two-component molding machine is used, the compounding of the compound discharged from the head is constant, and the molded product can be made of a stable material. That is, since molding can be performed by a two-component molding machine, production efficiency can be significantly improved.

The thermoplastic resin constituting the shell of the unfoamed heat-expandable micro hollow sphere (c) is preferably an acrylonitrile-vinylidene chloride copolymer or an acrylonitrile-methyl methacrylate copolymer.

The low-boiling hydrocarbon present in the hollow portion of the hollow body (c) preferably includes, for example, isobutane, pentane, isopentane, petroleum ether and the like. This unfoamed heat-expandable micro hollow sphere (c) is mainly foamed by the heat of reaction released when the isocyanate-terminated prepolymer (a) and the active hydrogen-containing compound (b) are mixed and stirred for reaction curing. Is what you do.

The exothermic temperature during the two-component reaction curing process is a maximum of 115 to 125 within the viscosity range in which the micro hollow sphere (c) can foam.
° C. Therefore, an unfoamed heat-expandable micro hollow body (c)
Is preferably in the range of 70 to 120 ° C. Particularly preferably, 80-1
The temperature is in the range of 10 ° C., and if it is in this range, a more uniform urethane molded product containing fine bubbles can be obtained.

The amount of the unfoamed heat-expandable micro hollow spheres (c) is determined based on the fluidity of the liquid when it is previously added and mixed with at least one of the isocyanate-terminated prepolymer (a) and the active hydrogen-containing compound (b). Can be added in a range that does not cause loss. That is, the amount of the unfoamed heat-expandable micro hollow spheres (c) is 0.1 to 100 parts by weight of the isocyanate-terminated prepolymer (a) or the active hydrogen-containing compound (b).
More preferably, it is in the range of 10 parts by weight. It is particularly preferably in the range of 2 to 5 parts by weight, and when used in this range, it is possible to handle in a relatively low viscosity range and to obtain a urethane molded article containing fine bubbles densely.

In the production method of the present invention, the unfoamed heat-expandable micro hollow sphere (c) is treated with an isocyanate-terminated prepolymer.
It is added to at least one of (a) or the active hydrogen-containing compound (b) and mixed in advance, and is manufactured by a two-component molding machine.
The mixing ratio of the two components when performing the curing reaction in the two-component component molding machine is determined by the molar ratio of the isocyanate groups of the isocyanate-terminated prepolymer (a) to the amino groups of the diamines in the active hydrogen-containing compound (b). You. The ratio is NH ₂
It is preferable that /NCO=0.7 to 1.2. In particular NH ₂ / NCO is preferably in the range of 0.8 to 1.0. 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 hydroxyl group of the polyol in the active hydrogen-containing compound (b) are 1: 1. It is determined by the molar ratio between the excess isocyanate group and the amino group of the diamine in the active hydrogen-containing compound (b) when the reaction is assumed to have been performed, and the ratio is preferably the same as the above-mentioned NH ₂ / NCO ratio. .

The temperature range of the isocyanate-terminated prepolymer (a) component and the active hydrogen-containing compound (b) component during 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.

The active hydrogen-containing compound (b) is, for example, a diamine at room temperature solids such as 3,3'-dichloro-4,
110 to 12 in the case of 4'-diaminodiphenylmethane
It is preferable that the diamines and the mixture of the diamines and the polyol which are liquid at room temperature be used in a temperature range of 25 to 70 ° C. in a temperature range of 0 ° C. Furthermore, the isocyanate-terminated prepolymer (a) and the active hydrogen-containing compound (b) are mixed with a non-foamed heat-expandable micro hollow sphere (c), and the unfoamed heat-expandable micro hollow sphere (c) is added. Must be used at a temperature setting lower than the onset of expansion.

Discharged from the head of a two-component molding machine
The two-liquid mixture composed of the components (a) + (b) + (c) is poured into a mold and the mold is clamped. At this time, the non-foamed heat-expandable micro hollow sphere (c) expands mainly by reaction heat released during the two-liquid curing reaction, but also expands by external heating. When the mold temperature is lower than 90 ° C., the resin in the part in contact with the mold is deprived of heat, so that foam unevenness occurs. If the mold temperature is higher than 120 ° C,
Since the expansion of the micro hollow sphere in the portion in contact with the mold is too fast, it causes the occurrence of foaming spots. Therefore, the mold temperature during molding is suitably in the range of 90 to 120 ° C, and ideally, it is preferable to increase the temperature to 90 to 120 ° C according to the heat generation behavior of the two-liquid mixture.

The non-foamed heat-expandable micro hollow sphere (c) is
It is better to disperse the active hydrogen-containing compound (b) in the active hydrogen-containing compound (b) than to add and mix it in advance with the isocyanate-terminated prepolymer. For example, room temperature liquid 3,5-bis (methylthio)
-2,4-toluenediamine, 3,5-bis (methylthio) -2,6-toluenediamine, chloroaniline-modified dichlorodiaminodiphenylmethane, poly (oxytetramethylene) glycol, poly (oxypropylene)
When a mixture with a polyether polyol such as a glycol, a polycarbonate polyol, a polyester polyol, or the like is used, it is possible to disperse a part or all of a predetermined amount. Unexpanded heat-expandable micro hollow sphere
(c) is a highly polar isocyanate-terminated prepolymer (a)
It is more preferable to use the compound dispersed in the active hydrogenation-containing compound (b) than to disperse the compound, and the storage stability of the compound is remarkably improved.

The unexpanded heat-expandable micro hollow sphere (c) is
The specific gravity changes with foaming due to the heat of reaction in the two-component reaction curing process and external heating.
(c) is in a system in which the periphery is thickened, and its specific gravity changes gradually, so that the fine hollow spheres (c) are not unevenly distributed in the molded product, and a good dispersion state is maintained. The foaming start temperature of the unfoamed heat-expandable micro hollow sphere (c) is
Each micro hollow sphere to react sensitively to the temperature in the system
The degree of foaming in (c) is the same, and the size of the micro hollow spheres in the molded product, that is, the cell size becomes uniform.

Therefore, the urethane molded product containing fine bubbles obtained in the present invention is a flat molded product, and since the material is stable, it is sliced in the horizontal direction with respect to the thickness to produce a thin plate-shaped polishing pad material. I do. 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. Further, the hardness of the fine bubble-containing molded product varies depending on the type of the isocyanate-terminated prepolymer (a), the active hydrogen-containing compound (b) and the unfoamed heat-expandable fine hollow spheres (c) to be used, and the amount added. , Preferably (Shore D) = 40-65
, And particularly preferably in the range of (Shore D) = 50 to 60.

Next, the present invention will be described specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. Parts in Examples and Comparative Examples represent parts by weight unless otherwise specified.

<Method of Evaluating Polishing Characteristics> A polishing rate polishing test is performed for one 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 urethane molded product containing fine bubbles are represented by A ± B, and the polishing characteristics and the 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.

( 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), minimum value (min) and average value (Ave) of the thickness difference before and after the polishing test at 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 dispersion 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.

(Comparative Example) Isocyanate-terminated prepolymer A (TDI / PTMG / DEG system, NCOeq = 5)
00) to 1000 parts EXPANCEL-551DE
(Expanded type-Microsphere, manufactured by Expancel) 23 parts of the compound was added and mixed at 70 ° C.
238 parts of BOCA were each heated to 120 ° C. After the resin obtained by mixing these two liquids was poured into a mold having a mold temperature of 100 ° C., the resin was heated and primary cured in an oven at 110 ° C. for 30 minutes. After demolding, the ingot was secondarily cured at 120 ° C. for 5 hours. The ingot was allowed to cool to 25 ° C,
To obtain a polishing pad.

Ten polishing pads manufactured by the above method were mounted on a polishing apparatus, and the polishing characteristics of the SiO ₂ film were measured. Wafer load 5.0 psi, platen rotation speed 280 rpm,
As a result of performing a polishing test under a polishing condition of a polishing time of 60 seconds, the polishing rate was 1860 ± 70 / min and the flatness was 10 ± 5%.

(Example 1) Matsumoto Microsphere F- was added to 1000 parts of isocyanate-terminated prepolymer A.
Compound and MB mixed with 40 parts of 301D (unfoamed microsphere, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.)
238 parts of OCA are charged to the A liquid tank and the B liquid tank of the elastomer casting machine, respectively. The A liquid system is operated at 70 ° C, and the B liquid system is operated at 120 ° C. After mixing the two liquid resins with a mixing head into a mold having a mold temperature of 100 ° C, the mold is closed and the temperature is raised to 110 ° C for 30 minutes in an oven. Heated and primary cured. 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 prepare a polishing pad.

Ten polishing pads manufactured by the above method were mounted on a polishing apparatus, and the polishing characteristics of the SiO ₂ film were measured. Wafer load 5.0 psi, platen rotation speed 280 rpm,
As a result of performing a polishing test under a polishing condition of a polishing time of 60 seconds, the polishing rate was 1900 ± 20 / min, the flatness was 6 ± 1%, and the lot-to-lot fluctuation of polishing characteristics could be reduced.

(Example 2) 1000 parts of isocyanate-terminated prepolymer A was added to Etacure-300 (BMTT)
Compounds obtained by adding and mixing 188 parts of Matsumoto Microsphere F-301D with 188 parts of DA (manufactured by Ethyl Corporation) are charged to the A liquid tank and the B liquid tank of an elastomer casting machine, respectively. The A liquid system is operated at 80 ° C, and the B liquid system is operated at 50 ° C. After mixing the two liquid resins with a mixing head into a mold having a mold temperature of 100 ° C, the mold is closed and the temperature is raised to 110 ° C for 30 minutes in an oven. Heated and primary cured. 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 prepare a polishing pad.

Ten polishing pads manufactured by the above method were mounted on a polishing apparatus, and the polishing characteristics of the SiO ₂ film were measured. Wafer load 5.0 psi, platen rotation speed 280 rpm,
As a result of performing a polishing test under a polishing condition of a polishing time of 60 seconds, the polishing rate was 1880 ± 20 / min, and the flatness was 5 ± 1%.

Example 3 Isocyanate-terminated prepolymer B (TDI / PTMG / DEG system, NCOeq =
400) and 1000 parts of Etacure-300 / PTMG
A compound obtained by adding and mixing 45 parts of Matsumoto Microsphere F-301D to 334 parts of a 1: 1 mixture of -Mw650 is charged into the A liquid tank and the B liquid tank of an 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 ° C., and after mixing the two-liquid mixed resin with a mixing head into a mold having a mold temperature of 100 ° C., the mold was closed, and the mixture was heated at 110 ° C. for 30 minutes in an oven and primary cured. 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 prepare a polishing pad.

Ten polishing pads manufactured by the above method were mounted on a polishing apparatus, and the polishing characteristics of the SiO ₂ film were measured. Wafer load 5.0 psi, platen rotation speed 280 rpm,
A polishing test was performed under a polishing condition of a polishing time of 60 seconds. As a result, the polishing rate was 1900 ± 30 / min, and the flatness was 7 ± 2%.

Example 4 1000 parts of isocyanate-terminated prepolymer B and aniline-modified MBOCA / PT
A compound obtained by adding and mixing 47 parts of Matsumoto Microsphere F-301D to 432 parts of a 1: 1 mixture of MG-Mw650 is charged into the A liquid tank and the B liquid tank of an elastomer casting machine, respectively. The A liquid system is operated at 80 ° C, and the B liquid system is operated at 50 ° C. After mixing the two liquid resins with a mixing head into a mold having a mold temperature of 100 ° C, the mold is closed and the temperature is raised to 110 ° C for 30 minutes in an oven. Heated and primary cured. 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 prepare a polishing pad.

Ten polishing pads manufactured by the above method were mounted on a polishing apparatus, and the polishing characteristics of the SiO ₂ film were measured. Wafer load 5.0 psi, platen rotation speed 280 rpm,
As a result of performing a polishing test under a polishing condition of a polishing time of 60 seconds, the polishing rate was 1910 ± 25 / min and the flatness was 6 ± 2%.

The compounds used are indicated by abbreviations, but the relationship between the abbreviations and the compounds is as follows. [Abbreviation] TDI: Tolylene diisocyanate PTMG: Poly (oxytetramethylene) polyglycol DEG: Polyethylene polyglycol MBOCA: 3,3'-Dichloro-4,4'-diaminodiphenylphenylmethane BMTTDA: N- (methylthio) toluene diamine aniline Modified MBOCA: Chloro Aniline-modified dichloroaminoaminophenylphenylmethane

[0048]

The urethane molded product containing fine bubbles molded by the production method and the resin composition of the present invention has stable cells since the cells are uniformly dispersed and the cell size is uniform. Therefore, the polishing pad manufactured by horizontally slicing this fine bubble-containing urethane molded product has excellent flatness and polishing characteristics, and there is no difference in density and hardness between the vicinity of the upper surface and the lower surface. The fluctuation of the polishing characteristics was greatly improved.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 33/20 C08L 33/20 75/04 75/04 // (C08G 18/10 101: 00)

Claims (5)

[Claims] When mixing and stirring two liquids of an isocyanate-terminated prepolymer (a) and an active hydrogen-containing compound (b),
Unfoamed, heat-expandable micro hollow spheres (c) are added and mixed in advance with at least one of the isocyanate-terminated prepolymer (a) and the active hydrogen-containing compound (b) as a foaming agent, and released during two-component reaction curing. Heat-expandable micro hollow spheres unfoamed by heat of reaction and external heating
A method for producing a microbubble-containing urethane molded product, characterized in that (c) is microfoamed in a urethane molded product, and the hollow microsphere (c) that has been heated and expanded is contained in the molded product. 2. The method for producing a urethane molded product containing fine bubbles according to claim 1, wherein the active hydrogen-containing compound (b) is a mixture of a polyol and a liquid polyamine, and is in a liquid state at room temperature. 3. The process for producing a urethane molded product containing fine bubbles according to claim 1, wherein the active hydrogen-containing compound (b) is a bis- (alkylthio) aromatic diamine at room temperature. 4. An unfoamed heat-expandable micro hollow sphere (c)
However, the hollow portion contains a low-boiling hydrocarbon, the shell portion is an acrylonitrile-vinylidene chloride copolymer or an acrylonitrile-methyl methacrylate copolymer is a minute hollow sphere composed of a heat expansion start temperature of 70 to 120 ° C. The method for producing a urethane molded product containing fine bubbles according to claim 1, wherein the molded product is within the range. 5. An isocyanate-terminated prepolymer (a),
An active hydrogen-containing compound (b), and a non-foamed heat-expandable fine hollow sphere (c), for a micro-bubble-containing molded article characterized in that the heat-expandable micro hollow sphere (c) is foamed by heat Urethane resin composition.