CN105008614B

CN105008614B - The manufacture method of hard sheet and hard sheet

Info

Publication number: CN105008614B
Application number: CN201480007963.2A
Authority: CN
Inventors: 目黑将司; 永山励; 高冈信夫; 林浩; 林浩一
Original assignee: Kuraray Co Ltd
Current assignee: Kuraray Co Ltd
Priority date: 2013-02-12
Filing date: 2014-02-05
Publication date: 2017-06-13
Anticipated expiration: 2034-02-05
Also published as: CN105008614A; EP2957672A1; KR20150116876A; WO2014125797A1; KR102136441B1; EP2957672B1; TWI607832B; JPWO2014125797A1; US20160002835A1; TW201440956A; JP6220378B2; EP2957672A4

Abstract

The present invention provides a kind of hard sheet, the non-woven fabrics that it contains superfine fibre and the macromolecular elastomer being imparted in non-woven fabrics, the JIS D hardness of the hard sheet is more than 45, to the section of thickness direction equably 3 decile, and from any one face side by 3 deciles after each layer be set to the first top layer successively, when intermediate layer and the second top layer, determine the JIS D hardness of respective any 3 points of 6 points of totals in first top layer and the intermediate layer, use the D hardness for amounting at 6 points, the R% calculated by following formula is 0~20%, and make the total content of the ion that the pH of water changes be 400 μ g/cm³Hereinafter, wherein R (%)=(D maximum hardness-D hardness minimum value)/D hardness average value × 100.

Description

The manufacture method of hard sheet and hard sheet

Technical field

The present invention relates to a kind of hard sheet, it is used preferably as the polishing layer of polishing pad, specifically, preferably as For being polished to semiconductor wafer, semiconductor devices, silicon wafer, hard disk, glass substrate, optical goods or various metals etc. The polishing layer of polishing pad use.

Background technology

Integrated circuit formed in semiconductor wafer is highly integrated and multilayer wiring.For such semiconductor die Piece, it is desirable to flatness high.

As the polishing method for polishing semiconductor wafer, it is known to chemically-mechanicapolish polish (CMP).CMP is while drop Plus polishing slurries (below, also referred to as slurry) containing abrasive grains, while being carried out to being polished substrate surface with polishing pad The method of polishing.

Following patent documents 1~4 disclose the polishing being made up of the foam polymer precursor with hole-closing structure for CMP Pad.Bi-component curable polyurethane is carried out pouring foaming formation and manufactured by foam polymer precursor.By foam polymer precursor Its rigidity of the polishing pad of manufacture is more padded than the polishing of non-woven fabric type described later.It is therefore preferable that for requiring the half of flatness high The polishing of conductor chip.

The rigidity of the polishing pad formed by foam polymer precursor is high.Therefore, the convex portion for being polished base material is optionally applied Loading.As a result, available polishing velocity higher.But, burnishing surface is present in the abrasive grains that there occurs cohesion In the case of, load optionally will be put on the abrasive grains of cohesion.Therefore, cut is easily produced on burnishing surface.It is special When not being that the advanced low-k materials weak to base material or interfacial adhesion with copper wiring are polished, cut is easily produced Or interface peel (referring for example to non-patent literature 1).In addition, in pouring foaming shaping, because macromolecular elastomer is easy not Equably foam, therefore, polishing velocity when being polished flatness and the polishing of base material easily becomes uneven.And then, pass through Abrasive grains or buffing are lentamente jammed in the closed pore of foam polymer precursor, and polishing velocity is slowly reduced.

Following patent documents 5~14 disclose a kind of polishing pad of non-woven fabric type, and it is the poly- ammonia of porous for solidifying wet type Ester is infiltrated in obtained from non-woven fabrics.Because the flexibility of non-woven fabric type polishing pad is excellent, therefore polishing pad is easily deformed.Cause This, it is difficult to the abrasive grains to condensing in burnishing surface optionally apply load, therefore are not likely to produce cut.But, due to nothing Spin cloth type polishing pad soft, therefore, polishing velocity is low.Further, since non-woven fabric type polishing pad follows the surface for being polished base material Shape and deform, therefore planarization performance is low, and the planarization performance is to make to be polished the flat characteristic of base material.

In addition, following patent documents 15~18 disclose a kind of non-woven fabrics containing superfine fibre with height planarization property The polishing pad of energy.Such as patent document 15 discloses a kind of polishing pad formed by tablet, and it makes with polyurethane as principal component Macromolecular elastomer be infiltrated in the nonwoven of the polyester superfine fibre beam obvolvent that average fineness is 0.0001~0.01dtex In cloth.The document discloses such polishing pad compared with existing polishing pad, high-precision polishing is realized.

In the polishing pad of the non-woven fabrics of common use superfine fibre, it is widely used for entering the superfine fibre of chopped fiber Non-woven fabrics obtained from the treatment of hand-manipulating of needle pierced holes.Such non-woven fabrics is because apparent density is low and voidage is high, therefore rigidity is low. Therefore, because follow the surface configuration of burnishing surface and deform, therefore planarization performance is low.

Patent document 19 discloses a kind of polishing pad, and it contains the fiber pseudoconjugant formed by the fibre bundle of superfine single fiber And macromolecular elastomer, a part for macromolecular elastomer is present in the inside of fibre bundle, and superfine single fiber has carried out boundling, removed The volume ratio for going to the part in space is 55~95% scope.

In addition, patent document 20 discloses a kind of polishing pad, it is throwing in the polishing pad with polishing layer and basalis Containing the intermediate layer that water absorption rate is less than 1% between photosphere and basalis, the difference of the D hardness of polishing layer and the D hardness in intermediate layer It is less than 20.

Prior art literature

Patent document

Patent document 1：Japanese Unexamined Patent Publication 2000-178374 publications

Patent document 2：Japanese Unexamined Patent Publication 2000-248034 publications

Patent document 3：Japanese Unexamined Patent Publication 2001-89548 publications

Patent document 4：Japanese Unexamined Patent Publication 11-322878 publications

Patent document 5：Japanese Unexamined Patent Publication 2002-9026 publications

Patent document 6：Japanese Unexamined Patent Publication 11-99479 publications

Patent document 7：Japanese Unexamined Patent Publication 2005-212055 publications

Patent document 8：Japanese Unexamined Patent Publication 3-234475 publications

Patent document 9：Japanese Unexamined Patent Publication 10-128674 publications

Patent document 10：Japanese Unexamined Patent Publication 2004-311731 publications

Patent document 11：Japanese Unexamined Patent Publication 10-225864 publications

Patent document 12：Japanese Unexamined Patent Application Publication 2005-518286 publications

Patent document 13：Japanese Unexamined Patent Publication 2003-201676 publications

Patent document 14：Japanese Unexamined Patent Publication 2005-334997 publications

Patent document 15：Japanese Unexamined Patent Publication 2007-54910 publications

Patent document 16：Japanese Unexamined Patent Publication 2003-170347 publications

Patent document 17：Japanese Unexamined Patent Publication 2004-130395 publications

Patent document 18：Japanese Unexamined Patent Publication 2002-172555 publications

Patent document 19：Japanese Unexamined Patent Publication 2008-207323 publications

Patent document 20：Japanese Unexamined Patent Publication 2011-200984 publications

Non-patent literature

Non-patent literature 1：" science (CMP サイエ Application ス) of CMP ", science forum of Co., Ltd. (Co., Ltd. サイエ Application スフォーラ system), August in 1997 20 days, p.113~119

The content of the invention

The invention problem to be solved

The present invention provides a kind of polishing pad that rheological parameters' change with time is difficult with polishing velocity and polishing velocity high.Solution is asked The method of topic

One aspect of the present invention is related to a kind of hard sheet, and it is included with the superfine of 0.0001~0.5dtex fiber numbers The non-woven fabrics of fiber and the macromolecular elastomer being imparted in non-woven fabrics, the JIS-D hardness of the hard sheet is more than 45, to thickness The section for spending direction equably carries out 3 deciles, and from any one face side by 3 deciles after each layer be set to the first table successively When layer, intermediate layer and the second top layer, the JIS-D hardness of respective any 3 points of 6 points of totals in the first top layer and intermediate layer is determined, made With the D hardness for amounting at 6 points, the R% calculated by following formula is 0~20%,

R (%)=(D maximum hardness-D hardness minimum value)/D hardness average value × 100,

Also, the total content for making the ion that the pH of water changes is 400 μ g/cm³Below.

In addition, another aspect of the present invention is related to a kind of polishing pad, it possesses above-mentioned hard sheet as polishing layer.

In addition, another aspect of the present invention is related to a kind of manufacture method of hard sheet, the method includes following operation：

(1) operation that superfine fibre occurs the long stapled fiber obvolvent piece of fiber type is prepared, the superfine fibre occurs The long stapled fiber obvolvent piece of fiber type can be processed by superfine fibre and form the pole with below 0.5dtex fiber numbers The non-woven fabrics of fine fibre, and the apparent density of the non-woven fabrics is 0.35g/cm³More than；

(2) first emulsion containing gelating agent and macromolecular elastomer is impregnated in fiber obvolvent piece, then make One emulsion gel, then be thermally dried, the operation for thus solidifying macromolecular elastomer, the gelating agent contains and makes water The ions that change of pH；

(3) superfine fibre treatment is carried out by there is fiber type to superfine fibre, is formed and containing non-woven fabrics and macromolecule The operation of the first complex of elastomer；

(4) second emulsion containing gelating agent and macromolecular elastomer is impregnated in the first complex, then added Heated drying, thus solidifies macromolecular elastomer, so that the operation of the second complex is formed, by second complex in thickness Direction equably carries out 3 deciles, and from any one face side by 3 deciles after each layer be set to the first top layer, centre successively When layer and the second top layer, the difference of the voidage in the first top layer and intermediate layer is less than 5%；

(5) the second complex is washed so that the total content of ion is 400 μ g/cm³Hereinafter, so as to obtain hard The operation of sheet material；And

(6) in order that the case hardness of hard sheet is JIS-D hardness more than 45, will be answered selected from the first complex, second At least one of fit and hard sheet carries out the operation of hot pressing.

The effect of invention

The present invention can obtain for obtain with polishing velocity and polishing velocity high not The book of Changes when the polishing pad that changes Hard sheet.

Brief description of the drawings

[Fig. 1] is a constructed profile for implementation method of hard sheet.

Symbol description

1 non-woven fabrics

1a superfine fibres

1b fibre bundles

2 macromolecular elastomers

3 first top layers

4 intermediate layers

5 second top layers

Specific embodiment

Hereinafter, an implementation method to hard sheet of the invention is described in detail.Fig. 1 is the hard of present embodiment The constructed profile of matter sheet material 10.In Fig. 1, part thereof of enlarged diagram is shown in the lump in the region surrounded with circle.

As shown in figure 1, hard of the hard sheet 10 comprising non-woven fabrics 1 and the macromolecular elastomer 2 being imparted in non-woven fabrics 1 Sheet material, the non-woven fabrics 1 is the pseudoconjugant of superfine fibre 1a.For hard sheet 10, its JIS-D hardness is more than 45, Equably carry out 3 deciles in thickness direction, and from face side by 3 deciles after each layer successively the first top layer 3, intermediate layer 4 and During the second top layer 5, each any 3 points JIS-D hardness for amounting at 6 points is determined in the first top layer 3 and intermediate layer 4, using amounting at 6 points D hardness, the R% calculated by following formula is 0~20%,

The D hardness average value of R (%)=(the D hardness minimum value in the point of D maximum hardness -6 in 6 points)/6 points × 100。

Additionally, it is preferred that the respective any 3 points JIS-D hardness for amounting at 6 points in determining the second top layer 5 and intermediate layer 4, using total 6 points of D hardness is counted, the R% calculated by above formula is also 0~20%.And, make what the pH of water changed in the hard sheet The total content of ion is 400 μ g/cm³Below.

In hard sheet 10, the superfine fibre 1a for forming non-woven fabrics 1 forms fibre bundle 1b, and the fibre bundle 1b is many Obtained from root superfine fibre 1a bunchys.In addition, multiple fibre bundle 1b is bonded by macromolecular elastomer 2 to each other.It is preferred that many More than half of individual fibre bundle 1b is bonded by macromolecular elastomer 2.And then, form the superfine fibre 1a of fibre bundle 1b to each other Bonded also by macromolecular elastomer 2.It is preferred that more than half of superfine fibre 1a is bonded by macromolecular elastomer 2.It is such The complex of the non-woven fabrics containing non-woven fabrics 1 and macromolecular elastomer 2 and macromolecular elastomer is that space is few, hardness is high and densification Hard sheet 10.Stiffening effect and the high fill-ratio of hard sheet that such hard sheet 10 is caused due to fibre bundle 1b (i.e. low porosity), therefore with high rigidity.

Hard sheet 10 contains the non-woven fabrics 1 of the superfine fibre for being formed with fibre bundle.It is present in the non-woven fabrics on surface Fibre bundle fibrillation or fibrillation in polishing.As a result, exposing the superfine fibre of high microsteping density in burnishing surface.The pole exposed Fine fibre is contacted with area wide with base material is polished, furthermore it is possible to keep substantial amounts of slurries.And then, due to the superfine fibre for exposing Dimension makes the surface of polishing pad soften, therefore, load is optionally applied to the condensation product of abrasive grains and is suppressed.As a result, The generation of cut can be suppressed.

In addition, the JIS-D hardness of hard sheet 10 is more than 45, hardness is adjusted to uniform in thickness direction so that survey The respective any 3 points JIS-D hardness for amounting at 6 points in fixed first top layer 3 and intermediate layer 2, and using 6 points of D hardness is amounted to, under The R% that formula is calculated is 0~20%,

R (%)=(D maximum hardness-D hardness minimum value)/D hardness average value × 100.

Additionally, it is preferred that hardness is adjusted into uniform in thickness direction so that in the second top layer 5 of measure and intermediate layer 2 each Any 3 points JIS-D hardness for amounting at 6 points, and the R% calculated using the D hardness for amounting at 6 points is also 0~20%.So, By being adjusted so that hardness reaches uniformly, the polishing of homogeneous can be carried out.

And, the total content that hard sheet 10 is adjusted to the ion for making the pH of water change is 400 μ g/cm³Below. In order to equably assign macromolecular elastomer in thickness direction as described above, in general, gelating agent can be used.Hard piece Contained ion can change the pH of slurries in polishing sometimes in material.In the case where the pH of slurries there occurs change, easily Polishing velocity is reduced, or easily condenses abrasive grains.In this case, by wash etc. make it is contained in hard sheet Ionic compound reduction, it is possible thereby to suppress the reduction of polishing velocity produced because the pH of slurries changes.Need explanation , the ion for making the pH of water change refers to all ions for changing pH when water is dissolved in.

As described in detail below, the hard sheet of present embodiment is by the fine and close non-woven fabrics in superfine fibre Thickness direction it is uniform and with containing ratio high impregnation assign macromolecular elastomer and manufacture.In addition, in such hard sheet In manufacture, in order to be assigned in non-woven fabrics macromolecular elastomer impregnation with containing ratio high, preferably use and contain gelating agent The emulsion of macromolecular elastomer.And, in the manufacturing process of hard sheet, can be by carrying out washing so that in gelating agent The contained ion total content for making the pH of water change is 400 μ g/cm³Hereinafter manufacture.

Hereinafter, each key element to the hard sheet of present embodiment is illustrated in further detail.

Non-woven fabrics in present embodiment is formed by superfine fibre, and superfine fibre is preferably formed as fibre bundle.

Superfine fibre has the fiber number of 0.0001~0.5dtex, the preferably fiber number with 0.001~0.01dtex.In pole Less than in the case of 0.0001dtex, in polishing, the superfine fibre of near surface is difficult to fully fibrillation to the fiber number of fine fibre, As a result, the reduction of slurries maintenance dose.In the case where the fiber number of superfine fibre is more than 0.5dtex, speed is polished because surface is excessively thick Degree is reduced, and abrasive grains easily condense upon the surface of superfine fibre.

Superfine fibre is long fibre (long filament), and specifically, preferably average fiber length is more than 100mm, further excellent Elect more than 200mm as.The upper limit of average fiber length is not particularly limited, as long as being not switched off in obvolvent operation described later, Several meters, hundreds of meters, the fiber of a few kms or its above length can also for example be included.The long fibre of superfine fibre is by making fiber Density improves to improve the rigidity of hard sheet.In addition, long fibre is difficult for drop-off in polishing.It should be noted that superfine fibre The chopped fiber of dimension is difficult to improve fibre density, it is impossible to obtain rigidity hard sheet high.In addition, chopped fiber easily takes off in polishing Fall.

Form the superfine fibre preferably many superfine fibre bunchys of non-woven fabrics and form fibre bundle.As being present in thickness side To section fibre bundle average cross-section, especially from from the aspect of can obtain rigidity hard sheet high, preferably 80 μ m²More than, more preferably 100 μm²More than, particularly preferably 120 μm²More than.

In addition, for being present in the fibre bundle in thickness direction section, relative to the fibre in the section of given thickness direction Total beam number of beam is tieed up, preferably with 40 μm²The fibre bundle of above sectional area is more than 25%.Particularly it is used to require flatness high Silicon wafer purposes, semiconductor wafer purposes, the polishing pad of semiconductor equipment purposes in the case of, with 40 μm²With upper section Long-pending fibre bundle is preferably more than 40%, more preferably more than 50%, particularly preferably 100%.40μm²Fiber above In the case that the ratio of beam is too low, there is the tendency of polishing velocity reduction or planarization performance step-down.

In addition, in the hard sheet of present embodiment, the Shu Mi of the fibre bundle of the unit area in the section of thickness direction Degree is preferably 600 beams/mm²Above, more preferably 1000 beams/mm²More than, and preferably 4000 beams/mm²Below, further Preferably 3000 beams/mm²Below.In the case of such Shu Midu, in polishing, the fibre bundle fibrillation or fibrillation on surface Change and form many superfine fibres, improve the maintenance dose of slurries.In addition, by fibre bundle fibrillation or fibrillation, burnishing surface Surface soften and suppress the generation of cut.In the case where Shu Midu is too low, there is the fibre of the superfine fibre for being formed in surface The tendency of dimension density step-down, polishing velocity reduction or planarization performance reduction.In addition, in the too high situation of the density of fibre bundle Under, there is the tendency of maintenance dose or the polishing velocity reduction of slurries because of surface excessively densification.It should be noted that in this implementation In the hard sheet of mode, from from the aspect of improving polishing stable, preferably in thickness direction and the density of face direction fibre bundle It is uneven small.

Superfine fibre is more than 50 DEG C preferably by glass transition temperature (Tg), further preferred by glass transition temperature (Tg) it is that more than 60 DEG C of thermoplastic resin is formed.In the case where the Tg of thermoplastic resin is too low, in polishing, rigidity is not Foot, planarization performance reduction, in addition, rigidity through when reduce and exist polishing stable or polishing uniformity reduction tendency.Tg The upper limit be not particularly limited, but industry manufacture on be preferably 300 DEG C, more preferably 150 DEG C.It should be noted that Due to turning into water suction state in polishing process, therefore, further preferably after treatment in 50 DEG C of warm water, in the shape of moistening It is more than 50 DEG C that the Tg for obtaining is determined under state.In addition, the water absorption rate of thermoplastic resin is preferably below 4 mass %, it is further excellent Elect as below 2 mass %.In the case where water absorption rate is more than 4 mass %, in polishing, because lentamente absorbing the moisture in slurries And make rigidity through when reduce.In this case, planarization performance easily through when reduce polishing velocity or polishing it is equal Even property easily changes.Water absorption rate is preferably 0~2 mass %.

As the specific example of thermoplastic resin, can enumerate for example：(PET, Tg are 77 to polyethylene terephthalate DEG C, the mass % of water absorption rate 1), isophthalate modified polyethylene terephthalate (Tg be 67~77 DEG C, the matter of water absorption rate 1 Amount %), the modified polyethylene terephthalate of sulfoisophthalic acid (Tg is 67~77 DEG C, the mass % of water absorption rate 1~4), (Tg is 124 DEG C, water suction for PBN (Tg is 85 DEG C, the mass % of water absorption rate 1), PEN The mass % of rate 1) etc. aromatic polyester-based resin；Terephthalic acid (TPA) and nonanediol and methyl ethohexadiol copolymer nylon (Tg is 125~ 140 DEG C, the mass % of water absorption rate 1~4) etc. semiaromatic polyamide composition resinoid etc..These materials can be used individually, also may be used To be applied in combination two or more.Wherein, from from the aspect of can also fully keep rigidity, water resistance and wear resistance, preferably gather Ethylene glycol terephthalate (PET), isophthalate modified polyethylene terephthalate, poly- naphthalenedicarboxylic acid butanediol Ester, PEN.The modified PET such as particularly PET and isophthalate modified PET, by fabric of island-in-sea type described later The netted obvolvent sheet material of composite fibre is significantly crispaturaed in forming the humid heat treatment operation of superfine fibre, therefore, from can be with shape Into fine and close and highdensity fiber pseudoconjugant, easily improve the rigidity of hard sheet and be not likely to produce moisture and cause in polishing Rheological parameters' change with time etc. from the aspect of be preferred.

In addition, not damaging in the range of effect of the present invention, can contain formed by other thermoplastic resins as needed Superfine fibre.As such thermoplastic resin, PLA, polybutylene terephthalate (PBT) can be applied in combination, gather right It is phthalic acid hexylene glycol ester, polydiethylene glycol succinate, polybutylene succinate, poly- butanedioic acid tetramethylene adipate, poly- The aromatic polyesters such as butyric ester-poly- hydroxyl pentanoate copolymer or aliphatic polyester and its copolymer；Nylon 6, nylon66 fiber, Amorphous nylon and its copolymers such as nylon 10, nylon 11, nylon 12；The TPOs such as polyethylene, polypropylene；Contain 25~70 The modified polyvinylalcohol of mole % ethylene units；The elastomers such as polyurethane elastomer, nylon-type elastomer, polyester elastomer Deng.

Hard sheet includes the macromolecular elastomer being imparted in the non-woven fabrics of superfine fibre.

As the specific example of macromolecular elastomer, can enumerate for example：Polyurethane, polyamide-based elastomer, (methyl) third Olefin(e) acid esters elastomer, (methyl) Acrylate-styrene bipolymer class elastomer, (methyl) acrylic ester-acrylonitrile class elastomer, (methyl) acrylate-olefin class elastomer, (methyl) acrylate-(hydrogenation) isoprenoid elastomer, (methyl) propylene Acid esters-butadiene type elastomer, styrene-butadiene class elastomer, styrene-hydrogenated isoprene class elastomer, acrylonitrile- Butadiene type elastomer, acrylonitrile-butadiene-styrene (ABS) class elastomer, vinyl acetate esters elastomer, (methyl) acrylic acid Ester-vinyl acetate esters elastomer, ethane-acetic acid ethyenyl ester class elastomer, ethylene-olefin class elastomer, polysiloxane-based bullet Gonosome, fluoroelastomer and polyester elastomer etc..

Macromolecular elastomer is preferably non-porous state.It should be noted that non-porous state refers to substantially without porous Shape or spongy macromolecular elastomer have as space (closed pore).For example, referring to not such as to make solvent polyurethane Such macromolecular elastomer with many closed pores obtained from solidification.

In the case where macromolecular elastomer is non-porous state, polishing stable high is can obtain, it is not easy to wear, in addition, slurry Liquid residue or polishing pad chip are difficult to remain in space.Therefore, it can keep polishing velocity high for a long time.Further, since right It is high in the cementability of superfine fibre, therefore, it is difficult to cause coming off for fiber.Further, since high rigidity is can obtain, therefore planarization Excellent performance.

The water absorption rate of macromolecular elastomer is preferably 0.5~8 mass %, more preferably 1~6 mass %.Macromolecule In the case that the water absorption rate of elastomer is too low, for the wettability reduction of slurries.As a result, there is polishing velocity, polishing uniformly Property, polishing stable reduction or abrasive grains easily cohesion tendency.In the situation that the water absorption rate of macromolecular elastomer is too high Under, polishing when hard sheet rigidity through when reduce, planarization performance reduction.In addition, polishing velocity or polishing uniformity It is susceptible to change.It should be noted that the water absorption rate of macromolecular elastomer refers to by the macromolecular elastomer after dried process Water absorption rate of film immersion when making its saturation swelling in the water of room temperature.It should be noted that containing two or more macromolecule In the case of elastomer, managed in the form of the value sum obtained by mass fraction is multiplied by the water absorption rate of each macromolecular elastomer By calculating.

The water absorption rate of macromolecular elastomer can be adjusted by importing hydrophilic functional group or the adjustment degree of cross linking It is whole.As hydrophilic functional group, can enumerate for example：The PAG base of carboxyl, sulfonic group and carbon number below 3 Deng.Hydrophilic radical can be imported by the way that the monomer with hydrophilic radical is carried out into copolymerization.As with hydrophilic radical Monomeric unit copolymerization ratios, preferably 0.1~20 mass %, more preferably 0.5~10 mass %.

Storage modulus [E ' (150 DEG C, dry (dry))] of the macromolecular elastomer at 150 DEG C be preferably 0.1~ 100MPa, more preferably 1~80MPa.The storage modulus of macromolecular elastomer can be adjusted by adjusting the degree of cross linking It is whole.It should be noted that in the case of containing two or more macromolecular elastomer, each high polymer elastic is multiplied by with mass fraction The form of the value sum obtained by [E ' (150 DEG C, dry (dry))] of body carries out theoretical calculation.

Macromolecular elastomer may be used singly or in combination of two or more.Wherein, glued to superfine fibre From the aspect of knot property is excellent, preferred polyurethane.

The superfine fibre of fibre bundle is preferably formed as by macromolecular elastomer boundling, the half of further preferred superfine fibre Radical above passes through macromolecular elastomer boundling.

Additionally, it is preferred that multiple fibre bundles are bonded by being present in the macromolecular elastomer on the outside of fibre bundle to each other, enter one The beam for walking more than half of preferred fibre bundle is bonded by macromolecular elastomer and existed with bulk.Glued to each other by fibre bundle Tie and improve the morphological stability of hard sheet, so as to improve polishing stable.By with macromolecular elastomer by superfine fibre Boundling or fibre bundle is bonded to one another, can obtain the uniform and high hard sheet of hardness.

In the case where there is no boundling in the superfine fibre for forming fibre bundle, because superfine fibre carries flexibility, therefore It is difficult to obtain planarization performance high.In addition, superfine fibre easily comes off in polishing, abrasive grains are condensed in the fiber for coming off Above easily produce cut.Superfine fibre refers to by macromolecular elastomer boundling：It is present in the superfine fibre inside fibre bundle It is present in the bonding of the macromolecular elastomer inside fibre bundle and is bound.

The ratio (non-woven fabrics/macromolecular elastomer) of non-woven fabrics and macromolecular elastomer in hard sheet is by quality ratio Preferably 90/10~55/45, more preferably 85/15~65/35.It is upper in the ratio of non-woven fabrics and macromolecular elastomer In the case of stating scope, the rigidity of hard sheet is easily improved.Furthermore it is possible to fully improve be exposed to hard sheet surface The density of superfine fibre.As a result, polishing stable, polishing velocity and planarization performance can be improved fully.

From from the aspect of keeping rigidity high, the apparent density of hard sheet is preferably 0.5~1.2g/cm³, it is further excellent Elect 0.6~1.2g/cm as³。

The JIS-D hardness of the hard sheet of present embodiment is more than 45, and 3 are equably carried out in the section of thickness direction Decile, and from any one face side by 3 deciles after each layer be set to the first top layer, intermediate layer and the second top layer successively when, The JIS-D hardness of respective any 3 points of 6 points of totals in the first top layer and intermediate layer is determined, using the D hardness for amounting at 6 points, by following formula The R% for calculating is 0~20%,

Average value × 100 of the D hardness of R (%)=(D maximum hardness-D hardness minimum value)/6 points.

Additionally, it is preferred that the respective any 3 points JIS-D hardness for amounting at 6 points in determining the second top layer and intermediate layer, uses total 6 points of D hardness, the R% calculated by above formula is also 0~20%.

The JIS-D hardness of hard sheet is more than 45, preferably 45~75, more preferably 50~70.By by The hardness on one top layer is adjusted to JIS-D hardness and is calculated as more than 45, can obtain planarization performance high.In JIS-D excessive high hardness In the case of, easily produce cut.It should be noted that due to making the superfine fibre of high microsteping density be exposed to surface, therefore, Although the hard sheet of present embodiment is hard, surface is soft.Therefore, it is not likely to produce cut.

The JIS-D hardness of respective any 3 points of 6 points of totals in the first top layer and intermediate layer is determined, it is hard using the D for amounting at 6 points Degree, the R% calculated by above-mentioned formula is 0~20%, preferably 0~15%.R% in the first top layer and intermediate layer is above-mentioned In the case of scope, in the case of as polishing pad, the change of the polishing velocity in the first top layer and intermediate layer diminishes, and can obtain The polishing performance of stabilization.In the case where R% is more than 20%, the change increase of polishing velocity in polishing, it is impossible to obtain stabilization Polishing performance.It should be noted that the arbitrary point for determining JIS-D hardness refers to：Which point measure in its layer is to appoint Meaning, no matter it is measured at which point, R% is 0~20%.In this case, due to not only in thickness direction and And will not also make hardness uneven in width, therefore, polishing velocity is also uniform in the in-plane direction, thus, can obtain stabilization Polishing performance.Similarly, the JIS-D hardness of respective any 3 points of 6 points of totals in the second top layer and intermediate layer is determined, using total 6 points of D hardness is counted, the R% calculated by above-mentioned formula is 0~20%, more preferably 0~15%.

For the hard sheet of present embodiment, the total content for making the ion that the pH of water changes is 400 μ g/ cm³Below.As described later, the hard sheet of present embodiment is manufactured as follows：For example it is impregnated in the emulsion of macromolecular elastomer In non-woven fabrics, then macromolecular elastomer is thermally dried and it is solidified, macromolecular elastomer is thus imparted to nothing In spinning cloth.In such operation, it is dried from surface containing the moisture in the emulsion being immersed in non-woven fabrics.Therefore, with water The carrying out of point evaporation, the migration for causing emulsion in non-woven fabrics to be moved to top layer.In the case where migration is caused, macromolecular elastomer Unevenly it is primarily present near the top layer of non-woven fabrics, the macromolecular elastomer near intermediate layer tails off, and space easily remains Near intermediate layer.Be matched with gelating agent in emulsion by such migrating across, and makes emulsion gel before it is dried and quilt Suppress.The present inventor etc. has found：In the gelating agent for obtaining it is contained make the ion that the pH of water changes with specified rate with On residue in hard sheet in the case of, can reduce polishing velocity in polishing.

The total content of the contained ion for making the pH of water change is 400 μ g/cm in hard sheet³Hereinafter, preferably It is 350 μ g/cm³, more preferably 100 μ g/cm³Below.In addition, the total content of ion is preferably 0 μ g/cm³, from industrial Washing efficiency from the aspect of, preferably 1~100 μ g/cm³, more preferably 10~50 μ g/cm³Left and right.In hard sheet The total content of the contained ion for making the pH of water change is more than 400 μ g/cm³In the case of, slurries cause pH to change, and throw Ray velocity reduction, further condenses easily abrasive grains.

It should be noted that the ion for making the pH of water change is all ions for changing pH when water is dissolved in, Specifically, sulfate ion contained in for example common gelating agent, nitrate ion, carbanion, ammonium can be enumerated Ion, sodium ion, calcium ion, potassium ion etc..

[manufacture method of polishing pad]

Below, to the manufacture method of hard sheet is described in detail.Hard sheet for example can be by following Operation is manufactured.

(1) operation that superfine fibre occurs the long stapled fiber obvolvent piece of fiber type is prepared

In this operation, prepare the long stapled fiber obvolvent piece that superfine fibre occurs fiber type.Superfine fibre generation type The long stapled fiber obvolvent piece of fiber can for example be manufactured as follows.

First, the long fibre net formed by islands-in-sea bicomponent fibre is manufactured, the islands-in-sea bicomponent fibre is with water-soluble warm Plastic resin is as sea component, using water-insoluble thermoplastic resin as island component.Islands-in-sea bicomponent fibre is by dissolving sea Composition and produce the superfine fibre formed by the resin of island component superfine fibre occur fiber type.It should be noted that at this In implementation method, to being illustrated using islands-in-sea bicomponent fibre as the example that superfine fibre occurs fiber type, but it is also possible to There is fiber type to replace islands-in-sea bicomponent fibre using the known superfine fibre such as multi-laminate stratotype cross-section fibers.

It is that can dissolve to remove or divide by water, alkaline aqueous solution, acidic aqueous solution etc. as water insoluble thermoplastic resin The thermoplastic resin for removing is solved, the resin for being capable of melt spinning is used.As the specific example of water insoluble thermoplastic resin, can arrange Citing is such as：The PVA resinoids such as polyvinyl alcohol (PVA), PVA copolymers；Containing polyethylene glycol and/or sulfonic acid alkali metal salts as altogether The modified poly ester being polymerized to point；PEO etc..Wherein, PVA resinoids are preferably used.

During by dissolving PVA resinoids as the islands-in-sea bicomponent fibre of sea component containing PVA resinoids, as island component Superfine fibre significantly crispatura.As a result, can obtain fibre density non-woven fabrics high.In addition, by the island containing PVA resinoids When type composite fibre dissolves PVA resinoids, will not decompose or dissolve as the superfine fibre or macromolecular elastomer of island component, Therefore, being difficult to cause the physical property of superfine fibre or macromolecular elastomer reduces.

As PVA resinoids, from from the aspect of the physical property for improving islands-in-sea bicomponent fibre, preferably use and rubbed containing 4~15 The ethylene modified PVA of your % ethylene unit, further preferably 6~13 moles % ethylene units.

The viscometric degree of polymerization of PVA resinoids is preferably 200~500, more preferably 230~470, particularly preferably 250~450 scope.In addition, as the fusing point of PVA resinoids, in terms of mechanical property and excellent heat stability and melting is spun From the aspect of silk property is excellent, preferably 160~250 DEG C, particularly preferably more preferably 175~224 DEG C, 180~220 DEG C Scope.

Used as the water-insoluble thermoplastic resin for forming island component, being will not be by water, alkaline aqueous solution, acidic aqueous solution etc. Dissolving removes or decomposes the thermoplastic resin for removing, it is possible to use be capable of the resin of melt spinning.As water-insoluble thermoplasticity The specific example of resin, can be used that the various resins of above-mentioned formation superfine fibre, preferably Tg are more than 50 DEG C and water absorption rate is The thermoplastic resin of below 4 mass %.

In addition, water-insoluble thermoplastic resin can for example contain catalyst, coloring preventing agent, heat-resistant agent, fire retardant, profit Lubrication prescription, anti-fouling agent, fluorescent whitening agent, delustering agent, colouring agent, gloss improvers, antistatic additive, aromatic, deodorant, antibacterial The additives such as agent, mite-proof agent, inorganic particles.

Islands-in-sea bicomponent fibre can be manufactured using composite spinning method, and the composite spinning method is by water insoluble thermoplastic The low water-insoluble thermoplastic resin of the compatibility of resin and water insoluble thermoplastic resin is carried out after melt spinning respectively, is made Its Composite.And, islands-in-sea bicomponent fibre preferably forms net with long stapled state.

The long stapled net of islands-in-sea bicomponent fibre can be obtained as below：For example, by spun-bond process by water insoluble thermoplastic resin With water-insoluble thermoplastic resin melt spinning, Composite is then carried out, further after stretching, pile up it.Need explanation It is that long fibre is the continuous fiber manufactured without cut off operation when manufacturing chopped fiber.Hereinafter, to the compound fibre of fabric of island-in-sea type One of the manufacture method of the long stapled net of dimension is described in detail.

First, water insoluble thermoplastic resin and water-insoluble thermoplastic resin are utilized respectively into respective extruder to be melted Melt mixing, the tow for making molten resin from different spinning-nozzles respectively sprays simultaneously.And, the tow being ejected is used compound After nozzle is compound, it is sprayed from the nozzle bore of spinneret, be consequently formed islands-in-sea bicomponent fibre.

The mass ratio of water insoluble thermoplastic resin and water-insoluble thermoplastic resin in islands-in-sea bicomponent fibre is without spy Do not limit, preferably 5/95~50/50, more preferably 10/90~40/60.In water insoluble thermoplastic resin and non-aqueous Property thermoplastic resin mass ratio in the case of above range, from the formation that can obtain highdensity non-woven fabrics, superfine fibre It is preferred from the aspect of property is also excellent.In addition, in melt composite spinning, the island number in islands-in-sea bicomponent fibre is preferably 4 ~4000 islands/fiber, more preferably 10~1000 islands/fiber.In addition, the fiber number of islands-in-sea bicomponent fibre is not limited especially It is fixed, but from from the viewpoint of industrialness, preferably 0.5~3dtex or so.

Islands-in-sea bicomponent fibre after being cooled down by cooling device, using aspirators such as jet nozzles equivalent to leading The high velocity air for drawing 1000~6000m/ of speed points of speed is stretched, and reaches target fiber number.Then, by that will stretch Composite fibre afterwards is piled up in the collection face of movable type and forms long stapled net.At this point it is possible to will be piled up as needed Long fibre net part pressure viscosity.

Then, net is overlapped multiple and make its obvolvent.The obvolvent treatment of net can be processed using needle point method or High-Pressure Water Etc. carrying out.As representative examples, the obvolvent treatment using needle point method is described in detail.

First, polysiloxane-based finish or the ore deposits such as finish, antistatic finish, the finish of raising obvolvent of pin bending will be prevented Thing oils finish is imparted in net.Then, net obvolvent is made by needle point method.From operability it is excellent from the aspect of, the net after obvolvent Weight per unit area is preferably 100~1500g/m²Scope.

Secondly, by making, the long stapled net of obvolvent shrinks and improves fibre density.With make chopped fiber net shrink Situation is compared, and is shunk by making long stapled net, can significantly be shunk.Shrink process preferably carries out the damp and hot contraction such as steam heating Treatment.As steam heating condition, can enumerate for example ambient temperature be 60~130 DEG C in the range of, relative humidity more than 75%, Further preferred relative humidity more than 90%, the condition for heating 60~600 seconds.

Damp and hot shrink process preferably makes institute in the way of percentage reduction of area is more than 35%, more preferably more than 40% The long stapled net of obvolvent shrinks.So, shrink it by with high shrinkage, fibre density becomes high.From the limit shunk From the aspect of degree and treatment effeciency, the upper limit of percentage reduction of area is preferably less than 80% Zuo You.It should be noted that area contraction Rate (%) is calculated using following formula.

Obvolvent before (area of the obvolvent net after the area-shrink process of the obvolvent net before shrink process)/shrink process Area × 100 of net

The obvolvent net for having carried out damp and hot shrink process in this wise further can be carried further by heating roller or hot pressing High microsteping density.As the change of the obvolvent net weight per unit area before and after damp and hot shrink process, with the unit before shrink process Area weight is compared, and the weight per unit area after shrink process is preferably more than 1.2 times (mass ratioes), and more preferably 1.5 Times more than and less than 4 times, more preferably less than 3 times.So, can obtain the long stapled net of islands-in-sea bicomponent fibre (hereinafter referred to as fiber obvolvent piece).

Such fiber obvolvent piece is converted to apparent density and is by the superfine fibre of islands-in-sea bicomponent fibre below 0.35~0.90g/cm³Non-woven fabrics.

It is significantly damp and hot by superfine fibre containing long stapled obvolvent net compared with the obvolvent net containing chopped fiber Shrink.Therefore, the fibre density of superfine fibre becomes finer and close.And, by optionally removing islands-in-sea bicomponent fibre Water insoluble thermoplastic resin, can form the non-woven fabrics of the fibre bundle containing superfine fibre.Now, in water insoluble thermoplastic resin quilt The part that dissolving is extracted forms space.Macromolecular elastomer is assigned with containing ratio high by the space, fiber will be constituted The superfine fibre boundling of beam, while fibre bundle is bonded to one another.So, can obtain that fibre density is high, voidage is low, rigidity is high Hard sheet.

(2) make to contain gelating agent (gelating agent contain make the pH of water change ion) and macromolecular elastomer First emulsion be impregnated in fiber obvolvent piece, then make first emulsion gelation, then be thermally dried, thus make macromolecule The operation of elastomer solidification

In this operation, macromolecular elastomer is filled uniformly with fiber obvolvent piece in thickness direction.Due to high score The emulsion of bullet gonosome be high concentration, low viscosity and impregnation impregnability it is also excellent, therefore, easily height is filled out in fiber obvolvent piece Fill.In addition, by making to contain gelating agent in the emulsion of macromolecular elastomer, emulsion can be suppressed when drying in thickness direction Uneven migration.

Situation from the solution using macromolecular elastomer usually used at present is different, is using macromolecular elastomer In the case of emulsion, the macromolecular elastomer of non-porous state can be formed.

As macromolecular elastomer, from the cementability to fiber it is high from the aspect of, the preferred macromolecular elastomer of hydrogen bond. The macromolecular elastomer of hydrogen bond be such as polyurethane, polyamide-based elastomer, polyvinyl alcohol elastomer etc. it is such by The elastomer that the macromolecule for being crystallized by hydrogen bond or being condensed is formed.

It is described in detail as representative examples when hereinafter, for using polyurethane as macromolecular elastomer.

As polyurethane, macromolecule polyol, the organic polyisocyanic acid by making mean molecule quantity 200~6000 can be enumerated Ester and chain extender are with various polyurethane obtained from given molar ratio reaction.

As the specific example of macromolecule polyol, can enumerate for example：Polyethylene glycol, polypropylene glycol, polytetramethylene two Polyether alcohol and its copolymer such as alcohol, poly- (methyltetramethylene glycol)；Polybutylene glyool adipate, poly- decanedioic acid Butyl glycol ester diol, polyhexamethylene adipate glycol, poly- (adipic acid 3- methyl isophthalic acids, 5- pentadiol esters) glycol, poly- (decanedioic acid 3- methyl isophthalic acids, 5- pentadiol esters) polyester polyol and its copolymer such as glycol, polycaprolactone glycol；Polyhexamethylene carbonic acid Esterdiol, poly- (3- methyl isophthalic acids, 5- pentylidene carbonic ester) glycol, poly-5-methylene carbonate glycol, polytetramethylene carbonic ester The polycarbonate-based polyalcohol such as glycol and its copolymer；Polyestercarbonate polyalcohol etc..In addition, can also combine making as needed With the polyfunctional alcohols such as 4 functional alcohols such as the functional alcohol of trimethylolpropane etc. 3, pentaerythrite or ethylene glycol, propane diols, 1,4- fourths two The short chain alcohols such as alcohol, 1,6-HD.These materials may be used singly or in combination of two or more.Particularly from can obtain To from the aspect of the hard sheet of the excellent in te pins of durability such as hydrolytic resistance, oxidative resistance, preferably use non-crystalline polycarbonate-based The polycarbonate-based polyalcohol of polyalcohol, ester ring type, the polycarbonate-based polyalcohol of straight-chain and above-mentioned polycarbonate-based polyalcohol with The mixture of polyether alcohol or polyester polyol.In addition, from the wettability to water it is especially good from the aspect of, preferably contain There is carbon number below 5, be particularly the polyurethane of PAG base of the carbon number below 3.

As the specific example of organic multiple isocyanate, can enumerate for example：Hexamethylene diisocyanate, isophorone two The aliphatic such as isocyanates, ENB diisocyanate, 4,4 '-dicyclohexyl methyl hydride diisocyanate or alicyclic two isocyanide Acid esters etc. is without xanthochromia type diisocyanate；2,4 toluene diisocyanate, 2,6- toluene di-isocyanate(TDI)s, 4,4 '-diphenylmethyl Aromatic diisocyanates such as alkane diisocyanate, xylylene diisocyanate polyurethane etc..In addition, as needed can be with It is applied in combination the polyfunctional isocyanates such as 3 functional isocyanates, 4 functional isocyanates.These materials can be used alone, and also may be used To be applied in combination two or more.It is wherein, high and from the aspect of can obtain hardness hard sheet high from the cementability to fiber, It is preferred that 4,4 '-dicyclohexyl methyl hydride diisocyanate, 2,4 toluene diisocyanate, 2,6- toluene di-isocyanate(TDI)s, 4,4 '-two Methylenebis phenyl isocyanate, xylylene diisocyanate.

As the specific example of chain extender, can enumerate for example：Hydrazine, ethylenediamine, propane diamine, hexamethylene diamine, nine methylenes Base diamines, xylylene diamine, IPD, piperazine and its derivative, adipic dihydrazide, isophthalic dihydrazide Deng Diamines；The amine of diethylenetriamine etc. three；The tetraamines such as triethylene tetramine；Ethylene glycol, propane diols, BDO, 1,6- The glycols such as hexylene glycol, 1,4- double (beta-hydroxy ethyoxyl) benzene, 1,4- cyclohexanediols；The alcohols of trimethylolpropane etc. three；Season penta The alcohols of tetrol etc. four；Alkamines such as ethylaminoethanol, aminopropanol etc..These materials can be used alone, it is also possible to which combination makes Use two or more.Wherein, from from the aspect of completing curing reaction in a short time, preferred compositions use hydrazine, piperazine, hexa-methylene Two or more in the triamine such as diamines, IPD and its derivative, ethene triamine.In addition, in chain extending reaction, can be with Chain extender is applied in combination with following substances, the material is：The monoamines such as ethamine, propylamine, butylamine；4-Aminobutanoicacid, 6- ammonia The carboxylic monoamine compound such as base caproic acid；The single methanol class such as methyl alcohol, ethanol, propyl alcohol, butanol.

In addition, by being applied in combination double (hydroxymethyl) propionic acid of 2,2-, double (hydroxymethyl) butyric acid of 2,2-, the double (hydroxyls of 2,2- Ylmethyl) imported into carboxyl isoiony group in the skeleton of polyurethane, can make to water by the carboxylic glycol such as valeric acid etc. Wettability further improve.

In addition, water absorption rate, storage modulus in order to control polyurethane, preferably contain more than 2 energy by adding intramolecular The crosslinking agent or polyisocyanates of enough functional groups with for forming the functional group reactionses that the monomeric unit of polyurethane has The self-crosslinking compound such as compound, multifunctional blocked isocyanate class compound and form cross-linked structure.

As the combination of the functional group of the functional group and crosslinking agent of monomeric unit, can enumerate：Carboxyl andOxazoline base, carboxylic Base and carbodiimide-based, carboxyl and epoxy radicals, carboxyl and cyclocarbonate radical, carboxyl and '-aziridino, carbonyl and hydrazine derivate, Hydrazide derivatives etc..Wherein, it is especially excellent from from the aspect of easily forming crosslinking, the rigidity of hard sheet or excellent in wear resistance Choosing has the monomeric unit of carboxyl and hasThe combination of the crosslinking agent of oxazoline base, carbodiimide-based or epoxy radicals, with hydroxyl The combination of the monomeric unit and the crosslinking agent with blocked isocyanate base of base or amino and the monomeric unit with carbonyl and The combination of hydrazine derivate or hydrazide derivatives.It should be noted that from the emulsion intercalation method that can keep macromolecular elastomer From the aspect of, preferably form cross-linked structure in the heat treatment step after polyurethane is imparted in fiber obvolvent piece.Wherein, The useful life of particularly preferred cross-linking properties and emulsion is excellent and carbodiimide-based that also had no problem in secure context And/orOxazoline base.As the crosslinking agent with carbodiimide-based, such as Misshin Spinning Co., Ltd's manufacture can be enumerated The moisture such as " CARBODILITE E-01 ", " CARBODILITE E-02 ", " CARBODILITE V-02 " dissipates Carbodiimides Compound.In addition, conduct hasThe crosslinking agent of oxazoline base, can enumerate such as Nippon Shokubai Co., Ltd's manufacture The moisture such as " Epocros K-2010E ", " Epocros K-2020E ", " EpocrosWS-500 " dissipatesOxazoline compound.Make It is the use level of crosslinking agent, relative to polyurethane, the active ingredient of crosslinking agent is preferably 1~20 mass %, more preferably 1.5~ 1 mass %, more preferably 2~10 mass %.

In addition, from improving to the cementability of superfine fibre so as to from the aspect of the rigidity for improving fibre bundle, as polyurethane The containing ratio of the composition of middle macromolecule polyol, preferably below 65 mass %, more preferably below 60 mass %.Separately Outward, from can be by assigning the elasticity of appropriateness come from the aspect of the generation for suppressing cut, preferably more than 40 mass %, further Preferably more than 45 mass %.

The method for preparing the emulsion of polyurethane is not particularly limited, it is possible to use known method.Specifically, can enumerate For example polyurethane is assigned as copolymer composition by using the monomer with hydrophilic radicals such as carboxyl, sulfonic group, hydroxyls Self emulsifiable method to water or add surfactant in polyurethane and make the method that it emulsifies.Due to containing tool There is the monomeric unit of hydrophilic radical excellent to the wettability of water as the macromolecular elastomer of copolymer composition, therefore, it can protect Hold substantial amounts of slurries.

As the specific example of the surfactant that can be used to emulsify, can enumerate for example：Lauryl sodium sulfate, dodecane It is base ammonium sulfate, polyoxyethylene tridecyl ether sodium acetate, neopelex, alkyl diphenyl base ether sodium disulfonate, two pungent The anionic surfactant such as base sodium sulfosuccinate；Ethylene nonyl phenyl ether, NONIN HS 240, polyoxy The non-ionic surfaces such as ethene lauryl ether, polyoxyethylene stearyl base ether, polyox-yethylene-polyoxypropylene block copolymer are lived Property agent etc..Further, it is possible to use the so-called reactive surfactant with reactivity.In addition, being lived by appropriate selection surface Property agent cloud point, can to emulsion assign heat-sensitive gel.

As the solid component concentration of emulsion, from macromolecular elastomer being filled in into fibre thickness direction is equably high From the viewpoint of in dimension obvolvent piece, preferably 15~40 mass %, more preferably 25~35 mass %.In addition, as breast The particle diameter of liquid, more preferably preferably 0.01~1 μm, 0.03~0.5 μm.

First emulsion includes the gelating agent containing the ion for making the pH of water change.Gelating agent is by making emulsion PH changes and is used to make emulsion particle gelation by heating.Done from surface containing the moisture in the emulsion being immersed in non-woven fabrics It is dry.Therefore, the carrying out of the evaporation of adjoint moisture, the migration for easily causing the emulsion in non-woven fabrics to be moved to top layer.In non-woven fabrics In emulsion there occurs migration in the case of, macromolecular elastomer is unevenly largely present near the top layer of non-woven fabrics, in Macromolecular elastomer near interbed tails off, the easy residual clearance near intermediate layer.In voids left near intermediate layer In the case of, the hardness reduction in intermediate layer, in addition, hardness becomes uneven.Such migration can be matched with by by gelating agent Make in emulsion and before it is dried emulsion gel and be suppressed.

As gelating agent, as long as the pH of emulsion is changed and is reached can make the journey of emulsion particle gelation by heating The water miscible salt of degree, it is possible to use with being not particularly limited.As its specific example, can enumerate as monovalence or divalence Inorganic salts such as sodium sulphate, ammonium sulfate, sodium carbonate, calcium chloride, calcium sulfate, calcium nitrate, zinc oxide, zinc chloride, chlorination Magnesium, potassium chloride, potassium carbonate, sodium nitrate, plumbi nitras etc..

It is excellent from from the aspect of can moderately assign gelation as the content ratio of the gelating agent in first emulsion Phase selection is 0.5~5 mass parts, more preferably 0.6~4 mass parts for the mass parts of macromolecular elastomer 100.

First emulsion can further contain penetrant, defoamer, lubricant, waterproofing agent, oil-proofing agent, tackifier, increment Agent, curing accelerator, antioxidant, ultra-violet absorber, fluorescer, mould inhibitor, foaming agent, polyvinyl alcohol and carboxymethylcellulose calcium Deng water-soluble high-molecular compound, dyestuff, pigment, inorganic particles etc..

The method for making first emulsion be impregnated in fiber obvolvent piece is not particularly limited, for example, dip/squeeze can be used (nip), the method such as cutter painting, rod painting or roller coat.

And, after first emulsion is impregnated in fiber obvolvent piece, heated, thus, first emulsion is embraced in fiber Close gelation in piece.As the heating condition for such gelation, preferably use for example 40~90 DEG C, further preferably The condition of 0.5~5 minute or so is kept at 50~80 DEG C.In addition, suppressing to cause because moisture drastically evaporates from top layer from one side Emulsion migration, while can also be uniformly heated up from the aspect of internal layer, heated preferably by steam.

And, make after first emulsion gelation, it is thermally dried, thus solidify macromolecular elastomer.

As heat drying, the method that is thermally dried in the drying devices such as air drier can be set forth in or red Method being thermally dried in drying machine after outside line heating etc..As the condition of heat drying, can enumerate for example with most The mode that high-temperature is 130~160 DEG C, further preferred maximum temperature is 135~150 DEG C heats the condition of 2~10 minutes.It is logical Heat drying is crossed, is made the moisture evaporation in first emulsion and macromolecular elastomer is equably condensed, it is possible thereby to by macromolecule Elastomer is also equably imparted in fiber obvolvent piece in thickness direction.

(3) superfine fibre treatment is carried out by there is fiber type to superfine fibre, is formed and containing non-woven fabrics and macromolecule The operation of the first complex of elastomer

There is the contained islands-in-sea bicomponent fibre in the fiber obvolvent piece of macromolecular elastomer to carry out pole by that will be impregnated with to assign Fibrillating treatment, forms the first complex of the non-woven fabrics containing superfine fibre and macromolecular elastomer.

This operation is by from containing as the water insoluble thermoplastic resin of island component and as the water-insoluble of sea component The superfine fibreization treatment of water insoluble thermoplastic resin is removed in the islands-in-sea bicomponent fibre of thermoplastic resin and superfine fibre is formed The operation of dimension.

Superfine fibreization treatment be by by the fiber obvolvent piece containing islands-in-sea bicomponent fibre water, alkaline aqueous solution, The water insoluble thermoplastic resin dissolving that hot water heating treatment is carried out in acidic aqueous solution etc. and sea component will be formed is removed or decomposed The treatment of removing.

As the specific example that hot water heating is processed, for example following method is preferably used：Fiber obvolvent piece impregnated in 65 In~90 DEG C of hot water 5~300 seconds as the first stage, then further in 85~100 DEG C of hot water treatment 100~ 600 seconds used as second stage.In addition, in order to improve dissolved efficiency, can carry out as needed using extrusion process, the height of roller Pressure current treatment, ultrasonication, flushing treatment, stir process, rub and process etc..

Hot water heating treatment is carried out by fiber obvolvent piece, water insoluble thermoplastic resin is molten from islands-in-sea bicomponent fibre Solve and form superfine fibre.It should be noted that when superfine fibre is formed, superfine fibre is significantly crispaturaed.The pole because this is crispaturaed The fibre density of fine fibre becomes fine and close.In addition, by removing water insoluble thermoplastic resin from islands-in-sea bicomponent fibre, in water Part existing for dissolubility thermoplastic resin forms space.Thereafter in operation, macromolecular elastomer is filled into the space.Separately Outward, hot water heating treatment is carried out by fiber obvolvent piece, contained gelating agent is also dissolved in hot water in fiber obvolvent piece And be removed.It is consequently formed the first complex.

(4) second emulsion containing gelating agent and macromolecular elastomer is impregnated in the first complex, then make Two emulsion gels, then be thermally dried, thus solidify macromolecular elastomer, so as to form the operation of the second complex

As described above, being combined in first formed by removing water insoluble thermoplastic resin from islands-in-sea bicomponent fibre In body, space is formed in the part existing for water insoluble thermoplastic resin.In order to obtain the homogeneous of present embodiment and with height The hard sheet of hardness, fills the space in the first complex to fetter superfine fibre using macromolecular elastomer.

By macromolecular elastomer is filled in remove water insoluble thermoplastic resin and in the space that is formed, can will be superfine The collection of filaments and reduce the voidage of hard sheet.In the case where superfine fibre forms fibre bundle, easily showed using capillary As impregnation emulsion.

As second emulsion, the emulsion same with first emulsion can be used.It should be noted that second emulsion and the first breast Liquid can be constituted for identical, or different compositions.

In this operation, preferably assign second emulsion and make its gelation so that the second complex that will be formed is in thickness Degree direction equably 3 decile, and from any one face side by 3 deciles after each layer be set to the first top layer, intermediate layer successively And during the second top layer, the difference of the voidage in the first top layer and intermediate layer is less than 5%, is more preferably less than 3%.By so entering Row adjustment, can obtain homogeneous and hardness hard sheet high.

It should be noted that the difference of the voidage in the first top layer and intermediate layer is calculated by following formula.

Difference (%)=absolute value (top layer of voidage (%)-the first in intermediate layer of the voidage in the first top layer and intermediate layer Voidage (%))

The voidage of each layer is obtained as follows.Using scanning electron microscope, with 30 times to the second composite thickness direction Section shot.Then, image analysis software Popimaging (Digital being kids.Co manufactures), use are used Dynamic thresholding method carries out binaryzation, specific space part to the image of resulting photo.And, describe inscribe in each space part Circle, using the gross area of its inscribed circle as all layers of pore volume.Then, using its photo, will be from the second composite thickness side To a surface rise thickness direction be divided into 1/3 part be set to the first top layer, will be from another surface in thickness side The second top layer being set to the part for being divided into 1/3, remaining layer being set to intermediate layer, total face of inscribed circle is obtained according to each layer Product, as the pore volume of each layer.Then, the voidage of each layer is obtained using following formula.

Pore volume × 100 (%) of the voidage of each layer=each layer pore volume/all layers

As the method in making second emulsion be impregnated in the first complex, make the method for its gelation and be thermally dried Method, can be used same with the method, the method that makes the method for its gelation and be thermally dried for making first emulsion impregnation Method.It is consequently formed the second complex.

(5) the second complex is washed so that the total content for making the ion that pH changes is 400 μ g/cm³Below Operation

As described above, the hard sheet of present embodiment is when macromolecular elastomer is imparted in non-woven fabrics, in order to press down Emulsion processed uses the emulsion containing gelating agent to the migration on top layer.The present inventor etc. has found：It is residual in the hard sheet for obtaining In the case of staying contained ion in many gelating agents, polishing velocity is reduced in polishing.And find：By washing The residual quantity for making ion is 400 μ g/cm³When following, the reduction of polishing velocity can be suppressed.

The operation washed is that the total content of the contained ion for making the pH of water change with hard sheet is 400 μg/cm³Below, 350 μ g/cm are preferably turned into³, further preferably turn into 100 μ g/cm³The operation that following mode is washed. As method for washing, consider from washing efficiency this respect high, preferably for example heat washing process.As specific condition, for example During second complex impregnated in into more than 80 DEG C of hot water.Specifically, can enumerate in the following example such as following conditions：As first In the stage, impregnated 5~300 seconds in 65~90 DEG C of hot water, then carry out the hot water at 85~100 DEG C as second stage Middle treatment 100~600 seconds.In addition, in order to improve washing efficiency, can carry out as needed using extrusion process, the height of roller Pressure current treatment, ultrasonication, flushing treatment, stir process, rub and process etc..

(6) in order that the case hardness of hard sheet is JIS-D hardness more than 45, will be answered selected from the first complex, second At least one of fit and hard sheet carries out the operation of hot pressing

Being present in the space inside hard sheet reduces the uniformity of hardness and hardness.In this operation, by will be upper The first complex, the second complex and/or the hard sheet stated carry out hot pressing, reduce space.Subtracted by making space in this wise Few, the apparent density of hard sheet is improved, and hardness, the uniformity of hardness and rigidity are improved.As autoclaving conditions, using setting For be heated to temperature that superfine fibre and macromolecular elastomer do not decompose, be for example heated to 160~180 DEG C of metallic roll with The condition that 30~100kg/cm of line pressure is pressurizeed.

Such operation, can obtain the hard sheet of present embodiment more than.The hard sheet of present embodiment is excellent It is elected to be as the polishing layer of polishing pad is used.Specifically, desired processing can be implemented as desired by hard sheet And form polishing layer.For example, implementing the fluffing treatment or the reversely brushing of sealing carried out using sand paper or pin cloth, diamond etc. Treatment, hot pressurized treatments or Embossing processing etc..Furthermore it is possible to form clathrate, concentric circles, whirlpool on the surface of hard sheet The grooves such as shape or hole.

In addition, as needed, can using hard sheet as polishing layer with compile thing, fabric, non-woven fabrics, elastic resin film or The elastomer layer lamination such as elastic sponge body.As elastic membrane and elastic sponge body, except containing being soaked with the current general polyurethane for using Non-woven fabrics (such as " Suba400 " (Nitta Hass (strain) manufactures)) outside, can enumerate：Natural rubber, nitrile rubber, poly- fourth The rubber such as diene rubber, silicon rubber；Polyester-type thermoplastic elastomer, polyamide-type thermoplastic elastomer, fluorine-containing thermoplastic elastic The thermoplastic elastomer (TPE)s such as body；Foamed plastic；Polyurethane etc..So, by laminar flexible body layer, the part of polished surface can be made Flatness (local flat of chip) is improved.It should be noted that polishing pad is except polishing layer and elastomer layer are by melting Bonding etc., also will be two-layer bonded using bonding agent or two-sided tape etc. directly obtained from engagement outside polishing pad Polishing pad or further between the two layers in the presence of other layers polishing pad.

The polishing pad of the hard sheet of present embodiment has been used to can be used for chemically-mechanicapolish polishing (CMP), the chemistry Mechanical polishing (CMP) is using known CMP devices and makes polished surface and throwing with constant speed under elevated pressure using slurries Light pad contacts certain hour.Slurries for example contain the liquid-like mediums such as water or oil；Silica, aluminum oxide, cerium oxide, oxidation The polishing agents such as zirconium, carborundum；The compositions such as alkali, acid, surfactant.In addition, when carrying out CMP, as needed can by slurries with Lubricating oil, cooling agent etc. are applied in combination.

It is not particularly limited as the article of polishing object, can be enumerated for example：Crystal, silicon, glass, optical substrate, electronics Circuit substrate, multi-layer wire substrate, hard disk etc..As polishing object, particularly preferably silicon wafer, semiconductor wafer.As half The specific example of conductor chip, can enumerate for example has the insulation of silica, fluorinated silicon oxide, organic polymer etc. on surface The semiconductor wafer of the barrier metal films such as the wiring material such as film, copper, aluminium, tungsten metal film, tantalum, titanium, tantalum nitride, titanium nitride etc..

Embodiment

Hereinafter, the present invention is illustrated by embodiment.It should be noted that the present invention is not by any limit of embodiment It is fixed.

First, the evaluation method that will be used in the present embodiment is summarized as follows and illustrates.

[apparent density of hard sheet]

With the quality (g/cm of unit area hard sheet²) divided by the value obtained by thickness (cm) as apparent density (g/ cm³).Then, to determining apparent density at any the 10 of hard sheet, arithmetic average is carried out, using resulting value as apparent Density.It should be noted that thickness is in load 240gf/cm according to JISL1096 standards²Lower measure.

[calculating of the measure and R% of the JIS-D hardness on the surface of hard sheet, the first top layer and intermediate layer]

The D hardness on the surface of hard sheet, the first top layer and intermediate layer according to JISK7311 standard tests.It is specific and Speech, for the D hardness on hard sheet surface, 8 is overlapped by the hard sheet of thickness about 1.25mm, impartial in width Ground determines 3 points of hardness, is averaged D hardness of the value as hard sheet surface.

In addition, for the D hardness on the first top layer, by by the hard sheet of thickness about 1.25mm from the second top layer side It is ground, has obtained the sheet material on first top layer of thickness 0.40mm.Then, the sheet material on the first top layer that will be obtained overlaps 25 , 3 points of hardness is equably determined in width, it is averaged JIS-D hardness of the value as the first top layer.In addition, for For the D hardness in intermediate layer, equably it is ground from the first top layer side and the second top layer side by by hard sheet, is obtained The sheet material in the intermediate layer of thickness 0.40mm.Then, the sheet material in the intermediate layer that will be obtained overlaps 25, is equably surveyed in width Fixed 3 points hardness, is averaged hardness of the value as intermediate layer.And, using 3 points of the first top layer for obtaining of D hardness and The value of the JIS-D hardness of 6 points of the total of the D hardness of 3 points of intermediate layer has obtained R (%) by following formula.

R (%)=(D maximum hardness-D hardness minimum value)/D hardness average value × 100

[making the total content of the ion that the pH of water changes]

The part and water 10mL that rectangular hard sheet will be cut into are put into screw-cap test tube.Then, block heater is used Screw-cap test tube is heated 2 hours at 90 DEG C, the water-soluble substances in hard sheet has been carried out into hot water extraction.Then, use Chromatography of ions (ICS-1600) detects the ion component in its extract solution.Wherein, determine as the pH for making water change from The sulfate ion of son and the total amount of ammonium ion, are scaled contained ionic weight in unit volume hard sheet.

[polishing velocity]

By the way that hard sheet to be cut into the toroidal of diameter 51cm, and clathrate ground is spaced in surface and is formed with 15.0mm The groove of width 1.0mm, depth 0.5mm, has thus made polishing pad.And, paste adhesive tape, Ran Houan at the back side of polishing pad Loaded on CMP planarization device (open country village of Co., Ltd. makes manufactured " PP0-60S ").Then, in platen rotating speed 70 rev/min, turn 69 revs/min of rotating speed of head, polish pressure 40g/cm²Under conditions of, while with 100ml/ points of speed supply slurries (Showa electrician strain The SHOROX A-31 of formula commercial firm manufacture) while being polished 3 hours to the synthetic quartz of 4 inches of diameter.And, after determining polishing Any 25 points of thickness in the face of synthetic quartz, average by the thickness polished in each point obtains polishing divided by polishing time Speed (nm/ points).

It should be noted that measure makes what first top layer and intermediate layer of the hard sheet of thickness about 1.25mm were exposed respectively The polishing velocity of the hard sheet of thickness 0.70mm.

[embodiment 1]

Using water-solubility PVA as sea component, using 6 moles of isophthalate modified PET of % of modified degree as island into Point.By water-solubility PVA and isophthalate modified PET at 260 DEG C with 25/75 (mass ratio) from melt composite spinning nozzle (island number：25 islands/fiber) spray.And, adjustment injector pressure makes spinning speed for 3700m/min, in online trapping fiber number The long fibre of 3dtex, obtains weight per unit area 35g/m²Net.

By cross layered, overlapping 16 is thrown the net, and has made total weight per unit area 480g/m²Overlay network.And, it is right Overlay network spraying prevents the finish that pin bends.Then, barb number 1 and the knitting needle and barb number 6 of knitting branch yarn 42 are used The knitting needle of individual and knitting branch yarn 42, by overlay network with 3150 pin holes/cm²Needling treatment is carried out, obvolvent net is resulting in. The weight per unit area of obvolvent net is 770g/m², splitting power is 9.6kg/2.5cm.In addition, obtained by needling treatment Percentage reduction of area is 25.8%.

Then, by obvolvent net under conditions of 110 DEG C, 23.5%RH steam treatment 70 seconds.Percentage reduction of area now It is 44%.Then, after drying in 90~110 DEG C of baking box it, hot pressing is carried out at 115 DEG C, thus obtains unit plane Product weight 1312g/m², apparent density 0.544g/cm³, thickness 2.41mm fiber obvolvent piece.

Then, make to be impregnated in fiber obvolvent piece as the emulsion of the polyurethane of first emulsion.It should be noted that poly- ammonia Ester is the PAG by polycarbonate-based polyalcohol and carbon number 2~3 with 99.8：0.2 (mol ratio) is mixed Mixture as polyol component, and containing the 1.5 carboxylic monomers of mass % without xanthochromia type polyurethane.In addition, poly- ammonia Ester is the polyurethane of the imporosity that cross-linked structure is formed by being heat-treated.First emulsion is adjusted to：Relative to poly- The mass parts of urethane 100, containing the mass parts of Carbodiimides crosslinking agent 4.6 and the mass parts of ammonium sulfate 1.8 as gelating agent, And the solid constituent of polyurethane is 20%.

By will containing be soaked with the fiber obvolvent piece of first emulsion heated under 90 DEG C, 30%RH atmosphere and made first breast Pension gelation, has further carried out dried process at 150 DEG C.Then, hot pressing is carried out at 140 DEG C, is thus adjusted to single Position area weight 1403g/m², apparent density 0.716g/cm³, thickness 1.96mm.

Then, processed by using extrusion process and High-Pressure Water, the fiber obvolvent piece for having polyurethane will be assigned at 95 DEG C Hot water in dipping 10 minutes and dissolve remove water-solubility PVA, be converted into the superfine fibre of fiber number 0.09dtex, then done It is dry.Thus, weight per unit area 1009g/m has been obtained², apparent density 0.538g/cm³, thickness 1.87mm the first complex.

Then, make to be impregnated in the first complex as the emulsion (the mass % of solid constituent 30) of the polyurethane of second emulsion In.It should be noted that polyurethane is identical with the polyurethane being above impregnated with.Second emulsion is adjusted to：Relative to polyurethane 100 mass parts, containing the mass parts of Carbodiimides crosslinking agent 4.6 and the mass parts of ammonium sulfate 1.0, and polyurethane solid constituent It is 30%.

By will containing be soaked with the first complex of second emulsion heated under 90 DEG C, 60%RH atmosphere and made second breast Pension gelation, has carried out dried process at 150 DEG C.Thus, weight per unit area 1245g/m has been obtained², apparent density 0.748g/cm³, thickness 1.66mm the second complex.The difference of the voidage on first top layer and intermediate layer of the second complex is 1.8%.

Then, the second complex is impregnated 10 points in 95 DEG C of hot water by using extrusion process and High-Pressure Water treatment Clock is washed.Then, dried at 180 DEG C.And, enter by under the conditions of line pressure 100kg/cm, 160 DEG C Row hot-pressing processing, has obtained weight per unit area 1212g/m², apparent density 0.795g/cm³, thickness 1.53mm hard sheet Intermediate.

Each grinding 0.15mm is distinguished to the two sides top layer of hard sheet intermediate using #100 paper, unit area is finish-machined to Weight 994g/m², apparent density 0.788g/cm³, thickness 1.26mm hard sheet.The JIS-D hardness of hard sheet is 52, The R% of JIS-D hardness is 11.3%.In addition, the sulfate radical as the ion for making pH change contained in hard sheet The total amount of ion and ammonium ion is 26.9 μ g/cm³。

Evaluation result is shown in table 1.

[embodiment 2]

Except carrying out heat under the conditions of line pressure 100kg/cm, 160 DEG C to the first complex before assigning second emulsion Outside pressure treatment, operate similarly to Example 1, manufacture hard sheet and evaluated.It should be noted that what is obtained is hard The weight per unit area of matter sheet material is 996g/m², apparent density be 0.808g/cm³, thickness be 1.23mm.Show the result in table 1.

[embodiment 3]

In addition to reducing the washing degree of the second complex in embodiment 1, operate similarly to Example 1, manufacture Hard sheet is simultaneously evaluated.Contained sulfate ion and ammonium as the ion for making pH change in hard sheet The total amount of ion is 300 μ g/cm³.Show the result in table 1.

[comparative example 1]

Except not washed to the second complex in embodiment 1, thus come replace by by the second complex 95 DEG C hot water in dipping beyond being washed, operate similarly to Example 1 within 10 minutes, manufacture hard sheet is simultaneously commented Valency.Show the result in table 1.

[comparative example 2]

In embodiment 1, the first complex further hot pressing has been carried out under the conditions of line pressure 100kg/cm, 160 DEG C Treatment, then, thus the emulsion of same composition of the impregnation without gelating agent is come to replace impregnation containing gelating agent second Emulsion, in addition, operates similarly to Example 1, manufactures hard sheet and is evaluated.It should be noted that obtaining Hard sheet weight per unit area be 969g/m², apparent density be 0.817g/cm³, thickness be 1.19mm.Show the result in Table 1.

[comparative example 3]

In addition to reducing the washing degree of the second complex in embodiment 1, operate similarly to Example 1, manufacture Hard sheet is simultaneously evaluated.Contained sulfate ion and ammonium as the ion for making pH change in hard sheet The total amount of ion is 404 μ g/cm³.Show the result in table 1.

[comparative example 4]

In addition to reducing the washing degree of the second complex in embodiment 1, operate similarly to Example 1, manufacture Hard sheet is simultaneously evaluated.Contained sulfate ion and ammonium as the ion for making pH change in hard sheet The total amount of ion is 504 μ g/cm³.Show the result in table 1.

As shown in Table 1, JIS-D hardness has been used to be 0~20%, make water for more than 45, R% for of the invention The total contents of ion that change of pH be 400 μ g/cm³The polishing pad of the hard sheet that following embodiment 1~3 is obtained and Speech, the polishing velocity on its first top layer, i.e. initial burnishing speed are 120nm/ point, to 5 hours after average value can keep at the beginning of More than the 90% of beginning polishing velocity.On the other hand, for using in second emulsion coordinate gelating agent and do not carry out fully For the polishing pad of the hard sheet of the comparative example 1 of washing, the polishing velocity on its first top layer is significant lower, is 93nm/ points.Separately Outward, the hard sheet of comparative example 2 is the homogenization that hard sheet is sought by hot pressing, thus replaces matching somebody with somebody in second emulsion Gelating agent is closed to fill uniformly with the example of macromolecular elastomer.For the polishing pad of comparative example 2, the total content of ion It is few, but R% is 30.2% and uneven.As a result, being only capable of keeping the 89% of initial burnishing speed to the average value after 5 hours. In addition, the total content of ion is 404 μ g/cm³The μ g/cm of comparative example 3 and 504³Comparative example 4, to 5 hours after average value it is equal About the 84% of initial burnishing speed can only be kept.

Claims

1. a kind of hard sheet, non-woven fabrics and be imparted to institute that it includes the superfine fibre with 0.0001~0.5dtex fiber numbers The macromolecular elastomer in non-woven fabrics is stated,

The JIS-D hardness of the hard sheet is more than 45,

To the section of thickness direction equably 3 decile, and from any one face side by 3 deciles after each layer be set to successively When one top layer, intermediate layer and the second top layer,

The JIS-D hardness of any 3 points of 6 points of totals of respective width in first top layer and the intermediate layer is determined, is made With the D hardness for amounting at 6 points, the R% calculated by following formula is 0~20%,

Average value × 100 of R (%)=(D maximum hardness-D hardness minimum value)/D hardness

2. hard sheet according to claim 1, wherein, the total content of the ion is 1~100 μ g/cm³。

3. hard sheet according to claim 1, wherein, the superfine fibre is long fibre, and forms fibre bundle.

4. hard sheet according to claim 3, wherein, the apparent density of the non-woven fabrics is 0.35~0.90g/cm³。

5. hard sheet according to claim 3, wherein, in the section of thickness direction, form the institute of the fibre bundle At least a portion for stating superfine fibre passes through the macromolecular elastomer boundling.

6. hard sheet according to claim 5, wherein, in the section of thickness direction, at least the one of the fibre bundle Part is bonded by the macromolecular elastomer each other.

7. hard sheet according to claim 3, wherein, in the section of thickness direction, form the institute of the fibre bundle The radical for stating more than half of superfine fibre passes through the macromolecular elastomer boundling.

8. hard sheet according to claim 7, wherein, in the section of thickness direction, the half of the fibre bundle with On beam bonded by the macromolecular elastomer each other.

9. hard sheet according to claim 1, wherein, the macromolecular elastomer is non-porous macromolecular elastomer.

10. hard sheet according to claim 1, wherein, the mass ratio of the non-woven fabrics and the macromolecular elastomer (non-woven fabrics/macromolecular elastomer) is 90/10~55/45.

11. hard sheets according to claim 10, its apparent density is 0.50~1.2g/cm³。

12. hard sheets according to claim 1, wherein, the JIS-D hardness on second top layer is more than 45,

Each any 3 points JIS-D hardness for amounting at 6 points is determined in second top layer and the intermediate layer, using amounting at 6 points D hardness, the R% calculated by following formulas is 0~20%,

A kind of 13. polishing pads, it possesses hard sheet any one of claim 1~12 as polishing layer.

A kind of 14. manufacture methods of hard sheet, the method includes following operations：

(1) operation that superfine fibre occurs the long stapled fiber obvolvent piece of fiber type is prepared, the superfine fibre generation type is fine The long stapled fiber obvolvent piece of dimension can be processed by superfine fibre and form the superfine fibre with below 0.5dtex fiber numbers The non-woven fabrics of dimension, and the apparent density of the non-woven fabrics is 0.35g/cm³More than；

(2) first emulsion containing gelating agent and macromolecular elastomer is impregnated in the fiber obvolvent piece, then make One emulsion gel, then be thermally dried, the operation for thus solidifying macromolecular elastomer, the gelating agent contains and makes water The ions that change of pH；

(3) superfine fibre treatment is carried out by there is fiber type to the superfine fibre, is formed and containing the non-woven fabrics and institute State the operation of the first complex of macromolecular elastomer；

(4) second emulsion containing the gelating agent and the macromolecular elastomer is made to be impregnated in first complex, It is thermally dried again, thus solidifies the macromolecular elastomer, so that the operation of the second complex is formed, by described second Complex equably carries out 3 deciles in thickness direction, and from any one face side by 3 deciles after each layer be set to successively When one top layer, intermediate layer and the second top layer, the difference of the voidage in first top layer and the intermediate layer is less than 5%；

(5) second complex is washed so that the total content of the ion is 400 μ g/cm³Hereinafter, it is hard so as to obtain The operation of matter sheet material；And

(6) in order that the case hardness of the hard sheet is JIS-D hardness more than 45, will be selected from first complex, institute Stating at least one of the second complex and the hard sheet carries out the operation of hot pressing.

The manufacture method of 15. hard sheets according to claim 14, wherein, the total content of the ion is 1~100 μ g/cm³。

The manufacture method of 16. hard sheets according to claim 14, wherein, it is bag that the superfine fibre occurs fiber type Island containing the water insoluble thermoplastic polyvinyl alcohol resin as sea component, the water-insoluble thermoplastic resin as island component Type composite fibre,

The superfine fibreization treatment of the operation (3) be make the water insoluble thermoplastic polyvinyl alcohol resin be dissolved in warm water and The operation for optionally removing.