CN1613607B

CN1613607B - Polishing kit for magnetic disk

Info

Publication number: CN1613607B
Application number: CN2004100784778A
Authority: CN
Inventors: 大泽清辉; 北山博昭; 萩原敏也
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2003-09-09
Filing date: 2004-09-09
Publication date: 2012-02-01
Anticipated expiration: 2024-09-09
Also published as: MY137560A; GB2406098B; TW200516133A; JP4336550B2; GB2406098A; JP2005081504A; US20050054273A1; TWI359859B; CN1613607A; GB0418338D0

Abstract

A polishing kit for a magnetic disk containing (A) a slurry containing an alumina, (B) an oxidizing agent solution containing an oxidizing agent, and (C) an acid agent solution containing an acid; a polishing kit for a magnetic disk containing (A) a slurry containing an alumina, and (D) an additive solution containing an oxidizing agent and an inorganic acid; and a polishing kit for a magnetic disk containing (A) a slurry containing an alumina, and (C) an acid agent solution containing an acid, wherein the polishing kit is used with an oxidizing agent solution (B) containing an oxidizing agent; and a polishing process for a magnetic disk substrate, including the steps of feeding a liquid mixture containing components of a specified polishing kit to a space between the magnetic disk substrate and a polishing cloth; and polishing the magnetic disk substrate with the liquid mixture. The polishing composition kit can be suitably used for the manufacture of high-quality magnetic disk substrates such as hard disks.

Description

Polishing kit for magnetic disk

Technical field

The present invention relates to polishing kit for magnetic disk (polishing kit), the Ginding process of magnetic disc substrate and the manufacturing approach of magnetic disc substrate.

Background technology

Smallest record area, propelling high capacity in order to reduce hard disk drive require to reduce the float-amount of magnetic head and do not have blemish (surperficial stain) in fact.In order to reduce the float-amount of this magnetic head, studied the grinding Liquid composition (open the 2003-147337 communique referring to Japanese patent of invention document spy, the spy opens flat 11-246849 communique) that contains aluminium oxide, oxidant and acid.

But these grinding Liquid compositions can not show grinding rate sometimes fully owing between the storage life after preparing, thereby lack repeatability.Therefore, the occasion that for example reduces at grinding rate in order to have enough grinding rates, must prolong milling time, the lapping liquid concentration the when dilution rate that perhaps reduces grinding Liquid composition is used to improve, thus keep grinding rate.As a result, existence needs the problem of degradation under the more costs of cost, the productivity ratio.

Summary of the invention

That is to say, the present invention relates to:

[1] a kind of polishing kit for magnetic disk, it comprises: contain aluminium oxide slurry (A), contain the oxidant liquid (B) of oxidant and contain acid sour agent liquid (C).

[2] a kind of polishing kit for magnetic disk, it comprises: contain the slurry (A) of aluminium oxide and contain oxidant and the additive liquid of inorganic acid (D).

[3] a kind of polishing kit for magnetic disk, it comprises: contain the slurry (A) of aluminium oxide and contain sour sour agent liquid (C), and this polishing kit uses with the oxidant liquid (B) that contains oxidant.

[4] a kind of Ginding process of magnetic disc substrate; It comprises the steps: the mixed liquor of sour agent liquid (C) that comprises slurry (A), the oxidant liquid (B) that contains oxidant that contains aluminium oxide and contain acid is supplied to the space between magnetic disc substrate and the abrasive cloth, grinds magnetic disc substrate with this mixed liquor.

[5] a kind of Ginding process of magnetic disc substrate; It comprises the steps: to grind magnetic disc substrate with comprising the slurry (A) that contains aluminium oxide and containing oxidant and the mixed liquor of the additive liquid of inorganic acid (D) is supplied to the space between magnetic disc substrate and the abrasive cloth with this mixed liquor.

[6] a kind of Ginding process of magnetic disc substrate; It comprises the steps: the mixed liquor that comprises slurry (A), the additive liquid (D) that contains oxidant and inorganic acid that contains aluminium oxide and contain organic acid acid agent liquid (c) is supplied to the space between magnetic disc substrate and the abrasive cloth, grinds magnetic disc substrate with this mixed liquor.

[7] a kind of manufacturing approach of magnetic disc substrate of grinding, it comprises following step:

(1) will contain the slurry (A) of aluminium oxide, the sour agent liquid (C) that contains the oxidant liquid (B) of oxidant and contain acid mixes and prepare the step of grinding Liquid composition,

(2) magnetic disc substrate is squeezed in the step of also pressurizeing on the abrasive cloth of grinding plate, and

(3) will be supplied to the space between magnetic disc substrate and the abrasive cloth by the grinding Liquid composition of step (1) preparation, start magnetic disc substrate and grinding plate simultaneously to grind the step of magnetic disc substrate.

[8] a kind of manufacturing approach of magnetic disc substrate of grinding, it comprises following step:

(1) will contain the slurry (A) of aluminium oxide and contain oxidant and the additive liquid of inorganic acid (D) mixes and prepares the step of grinding Liquid composition,

[9] a kind of manufacturing approach of magnetic disc substrate of grinding, it comprises following step:

(1) will contain aluminium oxide slurry (A), contain the additive liquid (D) of oxidant and inorganic acid and contain that organic acid acid agent liquid (c) mixes and the step for preparing grinding Liquid composition,

The specific embodiment

The present invention relates to the disk that contains aluminium oxide, oxidant and acid with lapping liquid in, can not rely on the manufacturing approach of the Ginding process and the good magnetic disc substrate of length between storage life, polishing kit for magnetic disk that repeatability shows high grinding rate well, magnetic disc substrate.

The polishing kit for magnetic disk of the application of the invention because the length, the repeatability that do not rely between storage life have shown high grinding rate well, has therefore realized making at low cost the effect of good disk.

These advantages of the present invention or other advantage can be found out from following explanation significantly.

A) polishing kit for magnetic disk

Polishing kit for magnetic disk of the present invention, being described below roughly is divided into three kinds.

(scheme a-1) a kind of polishing kit for magnetic disk, it comprises: contain aluminium oxide slurry (A), contain the oxidant liquid (B) of oxidant and contain acid sour agent liquid (C).

(scheme a-2) a kind of polishing kit for magnetic disk, it comprises: contain the slurry (A) of aluminium oxide and contain oxidant and the additive liquid of inorganic acid (D), and also optionally comprise and contain organic acid acid agent liquid (c).

(scheme a-3) a kind of polishing kit for magnetic disk, it comprises: contain the slurry (A) of aluminium oxide and contain sour sour agent liquid (C), and this polishing kit uses with the oxidant liquid (B) that contains oxidant.

One big characteristic of polishing kit for magnetic disk of the present invention (the following kit that is called simply) is the formation with aforementioned that kind.Owing to have such characteristic; Thereby the generation of the salt that has suppressed to be generated by each component reaction and the decomposition of each component can prevent the reduction of grinding rate, so have the length between the storage life of not relying on, the effect that repeatability has shown high grinding rate well.

Each component that scheme a-1～a-3 is used is described below.

(A) component: the slurry that contains aluminium oxide

The slurry of so-called (A) component is meant the component that contains aluminium oxide at least, from the viewpoint of storage stability, like said organic acid or the oxidant of not containing in fact in back.

From lowering percent ripple, lower surface roughness, improve grinding rate and preventing the viewpoint of blemish; As the aluminium oxide that uses in the present invention; Be 95% or above aluminum oxide (aluminum oxide) preferably as the purity of aluminium oxide (alumina); More preferably 97% or above aluminium oxide, further preferred 99% or above aluminium oxide.And from improving the viewpoint of grinding rate, preferred Alpha-alumina; From surface texture and the viewpoint that lowers percent ripple, intermediate aluminas such as preferred gama-alumina, δ-aluminium oxide, θ-aluminium oxide, η-aluminium oxide, κ-aluminium oxide.In the present invention; So-called intermediate alumina; Be the general name of the aluminium oxide particles beyond the alpha-alumina particle, specifically, can enumerate out gama-alumina, δ-aluminium oxide, θ-aluminium oxide, η-aluminium oxide, κ-aluminium oxide and their mixture etc.Among these intermediate aluminas, preferred gama-alumina, δ-aluminium oxide, θ-aluminium oxide and their mixture are from improving grinding rate and the viewpoint that lowers percent ripple, more preferably gama-alumina and θ-aluminium oxide.

For the average grain diameter of the primary particle of aluminium oxide, from lowering the viewpoint of percent ripple, preferably 0.005～0.8 micron of the average grain diameter of primary particle is more preferably 0.01～0.4 micron.From lowering the viewpoint of percent ripple, preferably 0.01～2 micron of the average grain diameter of the offspring of aluminium oxide is more preferably 0.05～1.0 micron, further preferably 0.1～0.5 micron.Observe or observe and carry out image analysis by scanning electron microscope, measure particle diameter, try to achieve the average grain diameter of the primary particle of aluminium oxide thus by transmission electron microscope.And the average grain diameter of offspring can be used laser diffractometry and measure as volume average particle size.

Wherein, be the occasion of intermediate alumina at aluminium oxide, the specific area of measuring with the BET method is 30～300m preferably ²/ g is more preferably 50～200m ²/ g.

From improving grinding rate and the viewpoint that lowers percent ripple, as aluminium oxide whetstone grain, the amalgam of Alpha-alumina and intermediate alumina is effective.In this case, the weight rate of Alpha-alumina and intermediate alumina (Alpha-alumina/intermediate alumina) preferably 99/1～30/70 is more preferably 97/3～40/60, and further preferably 95/5～50/50, more preferably 93/7～55/45.And as aforesaid amalgam, the amalgam of Alpha-alumina and θ-aluminium oxide is preferred.

From improving the viewpoint of grinding rate and economy, the content of aluminium oxide in slurry preferably 0.1 weight % or more than, be more preferably 0.5 weight % or more than, further preferably 1 weight % or more than.And from the viewpoint of the dispersion stabilization of slurry, the content of aluminium oxide 60 weight % or following preferably in slurry are more preferably 50 weight % or following, further 40 weight % or following preferably.That is to say that the content of the aluminium oxide in slurry is 0.1～60 weight % preferably, be more preferably 0.5～50 weight %, further 1～40 weight % preferably.

In addition, in the slurry of (A) component,, can add inorganic acid, organic acid or their salt such as sulfuric acid or nitric acid of necessary amount in order to improve dispersion stabilization and knot cake preventing property.In (A) component, inorganic acid or organic acid content is 0.01～5 weight % preferably, is more preferably 0.02～3 weight %, further 0.03～1 weight % preferably.And in (A) component, the content of inorganic acid or organic acid salt is 0.01～30 weight % preferably, is more preferably 0.05～20 weight %, further 0.1～15 weight % preferably.

And, as the medium (medium) of slurry, water such as ion exchange water, pure water, ultra-pure water can be enumerated out, and bactericide or antiseptic, pH adjustment agent etc. can be contained.And, can contain grinding materials such as silica.From the viewpoint of dispersion stabilization, the content of moisture in slurry preferably 40 weight % or more than, be more preferably 40～99.9 weight %.

(B) component: the oxidant liquid that contains oxidant

The oxidant liquid of so-called (B) component is the liquid that contains oxidant at least, from the viewpoint of storage stability, does not contain the metal ion, metal oxide and the organic compound that cause that oxidant decomposes in fact.Therefore, can contain the hydroxy ethylene-1 that oxidant is decomposed, the organic sulfonic acid that the 1-disulfonic acid is such.

Wherein, the content of aforementioned metal ion, metal oxide and organic compound in the oxidant liquid is 2 weight % or following preferably, are more preferably 1 weight % or following.

As the oxidant that can use in the present invention, can enumerate out salt, oxyacid or its salt, nitrate, the sulfate of peroxy acid or it of peroxide, metal, the slaine of acid etc.Oxidant roughly is divided into mineral-type oxidant and organic type of oxidant according to its structure.The object lesson of these oxidants is shown in down.As the mineral-type oxidant; Can enumerate out: hydrogen peroxide, further be the such alkali metal of sodium peroxide, potassium peroxide, calper calcium peroxide, barium peroxide, peromag or the peroxide of alkaline-earth metal, halogenated acids such as permanganic acid salt, sodium perchlorate, potassium hyperchlorate, chloric acid, clorox, sodium metaperiodate, potassium metaperiodate, acid iodide, sodium iodate such as chromium peroxide Barbiturates, potassium permanganate, sodium permanganate such as peroxidating borate family, peroxidating chromic acid sodium, peroxidating chromic acid potassium or their derivatives class, iron chloride (III), ferric sulfate inorganic acid slaines such as (III) such as peroxidating phosphoric acid such as peroxidating nitric acid such as peroxidation sulfuric acid such as peroxidating carbonates such as sodium carbonate peroxide, peroxidating potash, peroxidating two ammonium sulfate, peroxidating two sodium sulphate, potassium persulphate, peroxidating one sulfuric acid or its salt, peroxidating nitric acid, peroxidating sodium nitrate, peroxidating potassium nitrate or its salt, peroxidating sodium phosphate, peroxidating potassium phosphate, peroxidating ammonium phosphate or its salt, peroxidating Boratex, peroxide potassium borate.As organic type of oxidant, can enumerate out peroxides such as percarboxylic acids such as peracetic acid, performic acid, perbenzoic acid, tert-butyl peroxide, cumene peroxide, ironic citrate organic acid molysite such as (III).Among these materials, improve the occasion of property, operability such as acquired and water-soluble, preferred mineral-type oxidant at grinding rate relatively.In addition, consider, preferably do not contain the inorganic peroxide of heavy metal from the environmental problem aspect.And, from the viewpoint of the surperficial stain that prevents to be ground substrate, more preferably hydrogen peroxide, sulfuric peroxide Barbiturates, halogenated acid or their derivative, further hydrogen peroxide preferably.And oxidants such as these peroxide can be a kind of, also can mix use two kinds or more than.

In addition, in the oxidant liquid of (B) component, inorganic acids such as the sulfuric acid of stating after can containing, nitric acid, hydrochloric acid, phosphoric acid.

From improving grinding rate and the viewpoint that lowers percent ripple, the content of oxidant in oxidant liquid preferably 0.005 weight % or above, be more preferably 0.007 weight % or more than.And, from the viewpoint of surface quality, the content of oxidant preferably 60 weight % or following, more preferably 50 weight % or following in oxidant liquid.That is to say that the content of the oxidant in the oxidant liquid is 0.005～60 weight % preferably, be more preferably 0.007～50 weight %.

In addition, as the medium of oxidant liquid, water such as preferred ion exchanged water, pure water, ultra-pure water.In oxidant liquid, the content of said moisture preferably 40 weight % or more than, be more preferably 40～99.995 weight %.

(C) component: the sour agent liquid that contains acid

The sour agent liquid of so-called (C) component is the liquid that contains acid at least, from the viewpoint of storage stability, does not contain in fact and the metal oxide of aforementioned acid reaction such as aluminium oxide etc.And, contain the organic acid occasion that causes that oxidant decomposes at sour agent liquid, further do not contain oxidant in fact.The content of oxidant in this case 2 weight % or following preferably in sour agent liquid are more preferably 1 weight % or following.

Wherein, (C) content of the metal oxide in the component 2 weight % or following preferably are more preferably 1 weight % or following.

As acid, can enumerate out inorganic acid and organic acid.

As inorganic acid, can enumerate out halogen-containing inorganic acids such as inorganic phosphor-contained acid such as sulfur-bearing inorganic acid, phosphoric acid, pyrophosphoric acid, polyphosphoric acid, phosphonic acids, hydrochloric acid, bromic acid such as nitrogenous inorganic acid such as nitric acid, nitrous acid, sulfuric acid, sulfurous acid, amide groups sulfuric acid etc.Among these materials, from improving the viewpoint of grinding rate, preferably nitric acid, nitrous acid, sulfuric acid, acid amides sulfuric acid (amide sulfuric acid), be more preferably sulfuric acid, sulfurous acid and acid amides sulfuric acid, further sulfuric acid preferably.The content of inorganic acid in sour agent liquid preferably 0.005 weight % or more than; Be more preferably 0.007 weight % or more than; And from the viewpoint of surface quality, the content of inorganic acid 60 weight % or following preferably in sour agent liquid are more preferably 50 weight % or following.That is to say that the content of the inorganic acid in the sour agent liquid is 0.005～60 weight % preferably, be more preferably 0.007～50 weight %.

From improving grinding rate, lower the viewpoint of percent ripple, organic acid pK1 be 7 or below, be more preferably 5 or below, further preferably 4 or below, more preferably 2 or below.Wherein, pK1 is illustrated in the logarithm value of the inverse of the 1st acid dissociation constant under 25 ℃.The pK1 of each compound is recorded in chemical brief guide and changes in 4 editions (basis a piece of writing) II, pp316～325 (the Japanization association volume) etc.

As organic acid, from improving grinding rate, lower percent ripple and preventing the viewpoint of surperficial stain, preferred sulfur-bearing organic acid, carboxylic acid and phosphorous organic acid.Its object lesson is shown in down.As organic acid; Can enumerate out sulfur-bearing organic acid, ethyl phosphonic acid, butyl phosphoric acid, lauryl phosphoric acid, phosphonate group glycolic acid, hydroxy ethylene-1 such as polyacid, methanesulfonic acid, p-methyl benzenesulfonic acid, alkylsurfuric acid such as monocarboxylic acids such as formic acid, acetate, glycolic, lactic acid, propionic acid, hydracrylic acid, butyric acid, benzoic acid, glycine, oxalic acid, butanedioic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, itaconic acid, malic acid, tartaric acid, citric acid, isocitric acid, phthalic acid, nitrotrimethylolmethane acetate, ethylenediamine tetra-acetic acid, phosphorous organic acids such as 1-di 2 ethylhexyl phosphonic acid, phosphonic acid butane tricarboxylic acids, ethylenediamine tetramethylene phosphonic acid etc.Among these materials, from the viewpoint that improves grinding rate and lower percent ripple, preferred sulfur-bearing organic acid or phosphorous organic acid, more preferably organic sulfonic acid class or organic phosphine acids, further preferred organic sulfonic acid class.And, from the viewpoint that the stain of grinding charge prevents, preferred sulfur-bearing organic acid and carboxylic acid, more preferably organic sulfonic acid class and polybasic carboxylic acid class.These compounds can use separately, also can mix use.

From improving grinding rate and the viewpoint that lowers percent ripple, organic acid content in sour agent liquid preferably 0.005 weight % or more than, be more preferably 0.007 weight % or more than.And from the viewpoint of surface quality and economy, organic acid content preferably 60 weight % or following, more preferably 50 weight % or following in sour agent liquid.That is to say that the organic acid content in the aforementioned sour agent liquid is 0.005～60 weight % preferably, is more preferably 0.007～50 weight %.

As the medium of sour agent liquid, water such as preferred ion exchanged water, pure water, ultra-pure water.The content of this moisture in sour agent liquid preferably 40 weight % or more than, be more preferably 40～99.95 weight %.

In addition, the pH of sour agent liquid preferably 6 or below, be more preferably 0.1～5, further preferably 0.2～4.These pH can be through adding alkaline matters such as ammoniacal liquor, NaOH, potassium hydroxide, perhaps adds the salt such as ammonium salt, sodium salt, sylvite of the acid that is contained and adjust.

(D) component: the additive liquid that contains oxidant and inorganic acid

The additive liquid of so-called (D) component contains aforesaid oxidant and inorganic acid at least, does not contain the metal ion, metal oxide and the organic compound that cause that oxidant decomposes in fact.Therefore, can contain the hydroxy ethylene-1 that oxidant is decomposed, the organic phospho acid that the 1-di 2 ethylhexyl phosphonic acid is such.The content of oxidant and the content of inorganic acid are with aforementioned identical.

As the total amount of these components, in additive liquid preferably 0.01 weight % or more than, more preferably 0.01～80 weight %, further preferred 0.03～60 weight %, preferred again 0.05～50 weight %.

As the oxidant that in (D) component, uses and the preferred compositions of inorganic acid, can enumerate out the combination of hydrogen peroxide and sulfuric acid.

And as the content of metal ion, metal oxide and organic compound in (D) component, preferably 2 weight % or following are more preferably 1 weight % or following.

In addition, as the medium of additive liquid, water such as preferred ion exchanged water, pure water, ultra-pure water.The amount of this moisture in additive liquid preferably 20 weight % or more than, be more preferably 20～99.99 weight %.

(c) component: contain organic acid acid agent liquid

(c) component is meant the sour agent liquid that contains organic acid and same (D) component and usefulness at least.Same described in organic acid kind, its use amount and aforementioned (C) component, do not have special qualification.

Each kit of this programme a-1, a-2 and a-3 be through each component is cooperated so that the content that contains each aluminium oxide in the grinding Liquid composition of formation component of each kit, oxidant, acid in predetermined scope, thereby use.And, can mix water such as using ion exchange water, pure water, ultra-pure water in case of necessity.

From improving grinding rate and the viewpoint that lowers percent ripple; The content of the aluminium oxide in the grinding Liquid composition preferably 0.05 weight % or more than; Be more preferably 0.1 weight % or more than, further preferably more than the 0.5 weight %, more preferably 1 weight % or more than.From the viewpoint of surface quality and economy, the content of the aluminium oxide in the grinding Liquid composition is 40 weight % or following preferably, are more preferably 30 weight % or following, further 25 weight % or following preferably, 20 weight % or following preferably again.That is to say that the content of the aluminium oxide in the grinding Liquid composition is 0.05～40 weight % preferably, be more preferably 0.1～30 weight %, further 0.5～25 weight % preferably, 1～20 weight % preferably again.

From improving the viewpoint of grinding rate, attenuating percent ripple and attenuating substrate stain; The content of the oxidant in the grinding Liquid composition preferably 0.002 weight % or more than; Be more preferably 0.005 weight % or more than; Further preferably 0.007 weight % or more than, more preferably 0.01 weight % or more than.And from the viewpoint of surface quality and economy, the content of the oxidant in the grinding Liquid composition is 20 weight % or following preferably, are more preferably 15 weight % or following, further 10 weight % or following preferably, 5 weight % or following preferably again.That is to say that the content of the aluminium oxide in the grinding Liquid composition is 0.002～20 weight % preferably, be more preferably 0.005～15 weight %, further 0.007～10 weight % preferably, 0.01～5 weight % preferably again.

From taking into account the viewpoint that improves grinding rate, attenuating percent ripple and lower the substrate stain; The content of the acid in the grinding Liquid composition preferably 0.002 weight % or more than; Be more preferably 0.005 weight % or more than; Further preferably 0.007 weight % or more than, more preferably 0.01 weight % or more than.And from the viewpoint of surface quality and economy, the content of the acid in the grinding Liquid composition is 20 weight % or following preferably, are more preferably 15 weight % or following, further 10 weight % or following preferably, 5 weight % or following preferably again.That is to say that the content of the acid in the grinding Liquid composition is 0.002～20 weight % preferably, be more preferably 0.005～15 weight %, further 0.007～10 weight % preferably, 0.01～5 weight % preferably again.

In addition, in kit of the present invention, as required, can in each suitable component, cooperate inorganic salts, tackifier, antirust agent, alkaline matter etc.These compounds can use separately, also can mix use two kinds or more than.And from the viewpoint of economy, the content of these compounds 0.05～20 weight % preferably in the grinding Liquid composition that is obtained by kit is more preferably 0.05～10 weight %, further 0.05～5 weight % preferably.

In addition, in each component of kit, as required, can cooperate bactericide or antiseptic etc.Viewpoint from the performance function; And from influence and economical point to nonferromagnetic substance; The content of these bactericide, antiseptic 0.0001～0.1 weight % preferably in the grinding Liquid composition that obtains by kit; Be more preferably 0.001～0.05 weight %, further 0.002～0.02 weight % preferably.

The remainder of grinding Liquid composition is a water.The content of these water 55～99 weight % preferably in grinding Liquid composition are more preferably 60～99 weight %, further 70～95 weight % preferably.

In addition, kit of the present invention has the advantage that can obtain extremely excellent storage stability because each component such as (A) component is not preserved with other component with mixing.As the concrete scheme of these kits, can enumerate out packs each component such as (A) component into has the container such as jar, drum, other vessel of the material of patience and the kit that obtains to each component.

And each component of kit can be added with arbitrary method, purpose of mixing component and making.

By kit of the present invention constituting that component cooperates and the pH of the grinding Liquid composition that obtains, preferably according to suitable decisions such as the kind of grinding charge and desired qualities.From improving grinding rate and the viewpoint that lowers percent ripple, pH is low more good more, and still, from the viewpoint of the preventing property of corrosion of processing equipment and operator's security, it is 7 good more that pH approaches more.Therefore, consider the occasion of above-mentioned two kinds of viewpoints at the same time, pH preferably is at least 0.1 but be lower than 6, more preferably is at least 0.5 but be lower than 5, further preferably is at least 1 but be lower than 4, preferably is at least 1 but be lower than 3 again.The pH of kit can be through cooperate alkaline matters such as organic acids such as inorganic acids such as nitric acid, sulfuric acid, hydroxycarboxylic acid, polybasic carboxylic acid, aminopolycanboxylic acid or amino acid and their slaine or ammonium salt, ammoniacal liquor, NaOH, potassium hydroxide, ammonia aptly with required amount and is adjusted.

Being ground the magnetic disc substrate of substrate as the conduct of object of the present invention, is to use as the substrate of magnetic recording with medium.Object lesson as magnetic disc substrate; The representational substrate that has on the aluminium alloy plating Ni-P alloy form; Replace aluminium alloy and plate the substrate that Ni-P forms above that with glass or vitreous carbon but also can enumerating sends as an envoy to; Perhaps replace plating Ni-P, apply the substrate of various metallic compounds through plating or vapor deposition.

Kit of the present invention produces effect in polishing step especially, but in addition grinding steps, for example rub and also can likewise be suitable in the step etc.

B) Ginding process of magnetic disc substrate

The Ginding process of magnetic disc substrate of the present invention roughly is divided into following several schemes.

The Ginding process of (scheme b-1) a kind of magnetic disc substrate; It comprises the steps: the mixed liquor of sour agent liquid (C) that comprises slurry (A), the oxidant liquid (B) that contains oxidant that contains aluminium oxide and contain acid is supplied to the space between magnetic disc substrate and the abrasive cloth, grinds magnetic disc substrate with this mixed liquor.

The Ginding process of (scheme b-2) a kind of magnetic disc substrate; It comprises the steps: to grind magnetic disc substrate with comprising the slurry (A) that contains aluminium oxide and containing oxidant and the mixed liquor of the additive liquid of inorganic acid (D) is supplied to the space between magnetic disc substrate and the abrasive cloth with this mixed liquor.

The Ginding process of (scheme b-3) a kind of magnetic disc substrate; It comprises the steps: the mixed liquor that comprises slurry (A), the additive liquid (D) that contains oxidant and inorganic acid that contains aluminium oxide and contain organic acid acid agent liquid (c) is supplied to the space between magnetic disc substrate and the abrasive cloth, grinds magnetic disc substrate with this mixed liquor.

Here, (A) that uses in the Ginding process of magnetic disc substrate of the present invention, (B), (C), (D), (c) component, magnetic disc substrate etc. all can be with aforesaid identical.Therefore; The mixed liquor that in aforementioned schemes b-1, uses is that the grinding Liquid composition that obtains with the formation component of kit through coordinated scheme a-1 is identical, and the mixed liquor that uses among scheme b-2, the b-3 is that the grinding Liquid composition that obtains with the formation component of kit through coordinated scheme a-2 is identical.

In addition,,, do not have special qualification for the abrasive cloth that in the grinding steps of general magnetic disc substrate, uses gets final product as abrasive cloth, but the organic polymer class abrasive cloth of preferred porous matter.

In the Ginding process of aforementioned schemes b-1～b-3; For example; Grinding plate with the organic polymer class abrasive cloth etc. that has attached porous matter is seized magnetic disc substrate on both sides by the arms, aforementioned mixed liquor is supplied to abradant surface, Yi Bian exert pressure; Move grinding plate and magnetic disc substrate on one side, can grind magnetic disc substrate thus.As grinding plate,, do not have special qualification so long as those that in the grinding steps of general magnetic disc substrate, use get final product.And other conditions (quantity delivered of the kind of lapping device, grinding temperature, speed of gyration, grinding Liquid composition etc.) when grinding do not have special qualification yet.

As the example of the Ginding process of aforementioned schemes b-1～b-3, preferably have the method for following step: supplying with will be aforementioned in the component input container before grinding, and the mixed liquor that obtains in container for stirring.Before so-called the grinding, being meant the stage before grinding, from the viewpoint of the stability of mixed liquor, after mix, is short until the time of in grinding, using preferably.Structure, size and material as container do not have specific qualification, according to the quantity delivered of mixed liquor etc. aptly decision get final product.

And; Another example as the Ginding process of aforementioned schemes b-1～b-3; Can enumerate out following method: when the supply of each component; Use makes the feedway of supplying with each component connect in same or different at different position and different, makes each component interflow and the feedway supplied with, thereby supplies with the method for mixed liquor.As this feedway, preferably use pipeline.

For example; Ginding process as scheme b-1; Can enumerate out: (A) component, (B) component and (C) component are supplied to the 1st pipeline, the 2nd pipeline and the 3rd pipeline respectively; In the 4th pipeline that has engaged the 1st pipeline, the 2nd pipeline and the 3rd pipeline, aforementioned (A)～(C) component is mixed, supply with the method for resulting mixed liquor subsequently from the 4th pipeline.In addition, for mixing water, can one among the 1st～4 pipeline or above on engage the 5th pipeline.The size of the bonding station of the 1st～the 3rd pipeline, each pipeline, shape, configuration etc. on the 4th pipeline; With compound concentrations such as the aluminium oxide that contains in the number of the magnetic disc substrate of each grinding, size, each component, oxidant, acid etc. and different, cannot treat different things as the same.

Likewise; Ginding process as scheme b-2; Can enumerate out: (A) component and (D) component are supplied in the 1st pipeline and the 2nd pipeline separately; In the 3rd pipeline that has engaged the 1st pipeline and the 2nd pipeline, mix (A) component and (D) component, supply with the method for resulting mixed liquor subsequently from the 3rd pipeline.In addition, for mixing water, can one among the 1st～3 pipeline or above on engage the 4th pipeline.Ginding process as scheme b-3; Can enumerate out: (A) component, (D) component and (c) component are supplied to the 1st pipeline, the 2nd pipeline and the 3rd pipeline respectively; In the 4th pipeline that has engaged these the 1st pipelines, the 2nd pipeline and the 3rd pipeline, aforementioned (A), (D), (c) component are mixed, supply with the method for resulting mixed liquor subsequently from the 4th pipeline.In addition, for mixing water, can one among the 1st～4 pipeline or above on engage the 5th pipeline.The size of the bonding station of other pipeline, each pipeline, shape, configuration etc. on the 4th pipeline of the 3rd pipeline of scheme b-2, scheme b-3; With compound concentrations such as the aluminium oxide that contains in the number of the magnetic disc substrate of each grinding, size, each component, oxidant, acid etc. and different, cannot treat different things as the same.

Have the Ginding process of the magnetic disc substrate of the present invention of such formation through use, realized not relying between storage life, repeatability shows the effect of high grinding rate well.

C) manufacturing approach of magnetic disc substrate

The manufacturing approach of magnetic disc substrate of the present invention roughly is divided into following scheme:

(scheme c-1) comprises the manufacturing approach of the magnetic disc substrate of following step:

(scheme c-2) comprises the manufacturing approach of the magnetic disc substrate of following step:

(scheme c-3) comprises the manufacturing approach of the magnetic disc substrate of following step:

In addition, aforementioned (A), (B), (C), (D), (c) component, magnetic disc substrate, abrasive cloth, grinding plate etc. all can be with aforesaid identical.Therefore; The grinding Liquid composition that in aforementioned schemes c-1, uses is that the grinding Liquid composition that obtains with the formation component of kit through coordinated scheme a-1 is identical, and the grinding Liquid composition that uses among scheme c-2, the c-3 is that the grinding Liquid composition that obtains with the formation component of kit through coordinated scheme a-2 is identical.

In aforementioned grinding steps, the pressure when adding press contacts, from improving surface smoothing property, lower blemish and improving the viewpoint of grinding rate, preferably 1～20kPa is more preferably 3～15kPa.

And, for the method for starting substrate and grinding plate, can be known those methods, be not particularly limited.

Have the manufacturing approach of the magnetic disc substrate of the present invention of such formation through use, having can be economically, repeatability makes well that surface smoothing property is enhanced, the advantage of the high-quality magnetic disc substrate of few surface defects etc.

As the manufacturing approach of the magnetic disc substrate of aforementioned schemes c-1～c-3, preferably have the method for following step: supplying with will be aforementioned in the component input container before grinding, and the mixed liquor that obtains in container for stirring.Before so-called the grinding, being meant the stage before grinding, from the viewpoint of the stability of mixed liquor, after mix, is short until the time of in grinding, using preferably.Structure, size and material as container do not have specific qualification, according to the quantity delivered of mixed liquor etc. aptly decision get final product.

And; As other example, can enumerate out following method: when the supply of each component, the feedway of supplying with each component is connected in same or different at different position and different; The feedway that makes each component interflow and supply with, thereby the method for supply mixed liquor.As this feedway, preferably use pipeline.

Embodiment

Below the present invention disclosed in more detail and explain through embodiment, but these embodiment only are open the present invention, and do not mean that the present invention is carried out any qualification.

Embodiment 1～3, comparative example 1～4

[preparation of grinding Liquid composition]

In 2 liters of polyvinyl resin container mades, add each following material according to following match ratio; Make that gross weight is 1.5 kilograms; Make grinding Liquid composition through mixing: (average grain diameter of primary particle is 0.07 micron to the Alpha-alumina of 12.75 weight %; The average grain diameter of offspring is 0.3 micron, and specific area is 15m ²/ g, purity are 99.9%), 35% aquae hydrogenii dioxidi of the citric acid of the sulfuric acid of 0.8 weight %, 4.28 weight %, 7.31 weight % (counting 2.56 weight % with hydrogen peroxide), residue are ion exchange water.In addition, this grinding Liquid composition and ion exchange water are added in 4 liters of polyvinyl resin container mades so that gross weight is 4 kilograms with 1: 4 match ratio (weight ratio), mix, to make the grinding Liquid composition of reference example 1.

To have shown in the table 1 (A) component, (B) component of the polishing kit of the embodiment 1～3 that constitutes, comparative example 1～4 or (D) component and (C) or (c) component be added to separately in 2 milliliters of polyvinyl resin container mades, airtight and left standstill 28 days at 60 ℃.After leaving standstill; The component and the ion exchange water that in 4 liters of polyvinyl resin container mades, add each polishing kit with the match ratio shown in the table 1 (weight ratio) are so that gross weight is 4 kilograms; Mix, obtain the grinding Liquid composition of embodiment 1～3 and comparative example 1～4.

In addition, (A) component use with water as medium, contain the slurry of the Alpha-alumina of 12.75 weight %.In the table, the record of other component is meant that these components quantitatively contain with institute in aforementioned slurry.

(B) component is used 35% aquae hydrogenii dioxidi (counting 2.56 weight % with hydrogen peroxide) of 7.31 weight %.In the table, the record of other component is meant that these components quantitatively contain with institute in this aquae hydrogenii dioxidi.

(C) component is used sulfuric acid and citric acid, and its content is the amount of record in the table.(c) component is used citric acid, and its content is the amount of record in the table.(D) component is used sulfuric acid and aquae hydrogenii dioxidi, and its content is the amount of record in the table.

Grinding Liquid composition to obtaining grinds evaluation, measures grinding rate.Grinding rate with the grinding Liquid composition of reference example 1 is an a reference value 1, tries to achieve the relative value (grinding rate relatively) of grinding rate of the grinding Liquid composition of each embodiment, comparative example.The result is shown in Table 1.In addition, the mensuration of Ginding process and grinding rate is as shown in following.

[Ginding process]

The average rough degree Ra of center line that Talystep (the contact pilotage front end size of talysurf: 25 microns * 25 microns, bypass filter: 80 microns, measured length: 0.64 millimeter) through Rank Taylor-Hobson Limited system is measured is that 0.2 micron, thickness are that 1.27 millimeters, diameter are that grind according to following imposing a condition with two side machining apparatus on the surface of the substrate that constitutes of the aluminium alloy of the plating Ni-P of 3.5 inches (95.0 millimeters), obtains being used as the abrasive material of the aluminium alloy base plate that magnetic recording media forms with the plating Ni-P of substrate.

Impose a condition as shown in following.

< imposing a condition of two side machining apparatus >

Two side machining apparatus: SPEEDFAM CO., LTD. system, 9B type two side machining apparatus

Tonnage: 9.8kPa

Grinding pad: FUJIBO Co., Ltd. system " H9900S " (trade name)

Distal ends number: 50r/min

Grinding Liquid composition supply flow rate: 100ml/min

Milling time: 5 minutes

The number of the substrate that drops into: 10

[grinding rate]

Use measurer (Sartorius corporate system " BP-210S ") to measure the weight of each substrate before and after grinding, try to achieve the weight change of each substrate, as reduction, reduce speed divided by the value of milling time as weight with this reduction with the mean value of 10 substrates.The minimizing speed of weight is imported following formula, convert grinding rate (μ m/mn) to.

Weight reduces speed (g/min)={ weight (g) after weight (the g)-grinding before grinding }/milling time (min)

Grinding rate (μ m/min)=weight reduces speed (g/min)/substrate single face area (mm ²)/Ni-P coating density (g/cm ³) * 10 ⁶

Table 1

Polishing kit is formed

Match ratio (weight ratio) i/ii/iii/ ion exchange water

pH

Relative grinding rate

i

ii

iii

Embodiment 1

Alpha-alumina (12.75)

A

H ₂O ₂(2.56)

B

Sulfuric acid (0.8) citric acid (4.28)

C

1∶1∶1∶2

1.5

1.0

Embodiment 2

Alpha-alumina (12.75)

A

H ₂O ₂(2.56) sulfuric acid (0.8)

D

Citric acid (4.28)

c

1∶1∶1∶2

1.5

1.0

Embodiment 3

Alpha-alumina (12.75)

A

H ₂O ₂(2.56) sulfuric acid (0.1)

B

Sulfuric acid (0.7) citric acid (4.28)

C

1∶1∶1∶2

1.5

1.0

Reference example 1

Alpha-alumina (12.75) H ₂O ₂(2.56) sulfuric acid (0.8) citric acid (4.28)

-

(after preserving, preparing, grinding evaluation immediately) at 60 ℃

1∶-∶-∶4

1.5

1.0

Comparative example 1

Alpha-alumina (12.75) H ₂O ₂(2.56)

-

Sulfuric acid (0.8) citric acid (4.28)

C

1∶-∶1∶3

1.5

0.78

Comparative example 2

Alpha-alumina (12.75)

A

H ₂O ₂(2.56) sulfuric acid (0.8) citric acid (4.28)

-

1∶1∶-∶3

1.7

0.89

Comparative example 3

Alpha-alumina (12.75) sulfuric acid (0.8) citric acid (4.28)

-

H ₂O ₂(2.56)

B

-

1∶1∶-∶3

2.8

0.89

Comparative example 4

Alpha-alumina (12.75) H ₂O ₂(2.56) sulfuric acid (0.8) citric acid (4.28)

-

1∶-∶-∶4

2.8

0.56

Annotate: go up in the table data representation use level (in weight %) in () number.Remainder is a water.

Shown in the result in the table 1; Can know; The abrasive composition that the polishing kit of comparative example 1～4 obtains, the grinding rate after 60 ℃ of preservations grinds when estimating the grinding rate of (reference example 1) immediately and compares with processing the back without preservation, reduce significantly.Relative therewith, the grinding rate of grinding Liquid composition after 60 ℃ of preservations that obtains from the polishing kit of embodiment 1～3 is identical with the situation of reference example 1, can repeatability be maintained well.

Embodiment 4,5 and comparative example 5～7

Use has the embodiment 4,5 of formation shown in the table 2 and the polishing kit of comparative example 5～7, in addition likewise makes grinding Liquid composition with embodiment 1.These grinding Liquid compositions are ground evaluation.Grinding rate with the grinding Liquid composition of reference example 2 is an a reference value 1, tries to achieve the relative value of grinding rate of the grinding Liquid composition of each embodiment, comparative example.The result is shown in Table 2.In addition, except according to the composition shown in the table 2, the grinding Liquid composition of all the other and reference example 1 likewise prepares with the grinding Liquid composition of reference example 2.

Table 2

	Polishing kit is formed						Match ratio (weight ratio) i/ii/iii/ ion exchange water	pH	Relative grinding rate
										i		ii		iii
	Embodiment 4	Alpha-alumina (12.75)	A	H ₂O ₂(2.56)	B	Sulfuric acid (7.4)										C	1∶1∶1∶2	1.0	1.0
Embodiment 5							Alpha-alumina (12.75)	A	H ₂O ₂(2.56) sulfuric acid (7.4)	D	-	-	1∶1∶-∶3	1.0	1.0
	Reference example 2	Alpha-alumina (12.75) H ₂O ₂(2.56) sulfuric acid (7.4)	-	(after preserving, preparing, grinding evaluation immediately) at 60 ℃												1∶-∶-∶4	1.0	1.0
Comparative example 5								Alpha-alumina (12.75) H ₂O ₂(2.56)	-	-	-	Sulfuric acid (7.4)	C	1∶-∶1∶3	1.0				0.75
	Comparative example 6	Alpha-alumina (12.75) sulfuric acid (7.4)	-	H ₂O ₂(2.56)	B	-	-									1∶1∶-∶3	2.3	0.88
Comparative example 7								Alpha-alumina (12.75) H ₂O ₂(2.56) sulfuric acid (7.4)	-	-	-	-	-	1∶-∶-∶3	2.3				0.25

Shown in the result in the table 2; Can know; The abrasive composition that the polishing kit of comparative example 5～7 obtains, the grinding rate after 60 ℃ of preservations grinds when estimating the grinding rate of (reference example 2) immediately and compares with processing the back without preservation, reduce significantly.Relative therewith, the grinding rate of grinding Liquid composition after 60 ℃ of preservations that obtains from the polishing kit of embodiment 4,5 is identical with the situation of reference example 2, can repeatability be maintained well.

Embodiment 6 and comparative example 8～11

Except use had shown in the table 3 polishing kit of the embodiment 6 that constitutes and comparative example 8～11, other and embodiment 1 likewise made grinding Liquid composition.These grinding Liquid compositions are ground evaluation.Grinding rate with the grinding Liquid composition of reference example 3 is an a reference value 1, tries to achieve the relative value of grinding rate of the grinding Liquid composition of each embodiment, comparative example.The result is shown in Table 3.In addition, except according to the composition shown in the table 3, the grinding Liquid composition of all the other and reference example 1 likewise prepares with the grinding Liquid composition of reference example 3.

Table 3

	Polishing kit is formed						Match ratio (weight ratio) i/ii/iii/ ion-exchange	pH	Relative grinding rate
										i		ii		iii
	Embodiment 6	Alpha-alumina (12.75)	A	H ₂O ₂(2.56)	B	Citric acid (14.5)										C	1∶1∶1∶2	1.8	1.0
Reference example 3							Alpha-alumina (12.75) H ₂O ₂(2.56) citric acid (14.5)	-	(after preserving, preparing, grinding evaluation immediately) at 60 ℃				1∶-∶-∶4	18	1.0
	Comparative example 8	Alpha-alumina (12.75)	A	H ₂O ₂(2.56) citric acid (14.5)	-	-										-	1∶1∶-∶3	2.0	0.75
Comparative example 9							Alpha-alumina (12.75) H ₂O ₂(2.56)	-	-	-	Citric acid (14.5)	C	1∶-∶1∶3	1.8	0.63
	Comparative example 10	Alpha-alumina (12.75) citric acid (14.5)	-	H ₂O ₂(2.56)	B	-										-	1∶1∶-∶3	2.8	0.75
Comparative example 11							Alpha-alumina (12.75) H ₂O ₂(2.56) citric acid (14.5)	-	-	-	-	-	1∶-∶-∶4	2.8	0.50

θ-aluminium oxide: the average grain diameter of offspring is 0.2 micron, and specific area is 120m ²/ g, purity are 99.9%.

Shown in the result in the table 3; Can know; The abrasive composition that the polishing kit of comparative example 8～11 obtains, the grinding rate after 60 ℃ of preservations grinds when estimating the grinding rate of (reference example 3) immediately and compares with processing the back without preservation, reduce significantly.Relative therewith, the grinding rate of grinding Liquid composition after 60 ℃ of preservations that obtains from the polishing kit of embodiment 6 be identical with the situation of reference example 3, can repeatability be maintained well.

Embodiment 7～18 and comparative example 12～18

Except use has table 4, the polishing kit of the embodiment 7～18 that constitutes shown in 5 and comparative example 12～18, other and embodiment 1 likewise make grinding Liquid composition.These grinding Liquid compositions are ground evaluation.Grinding rate with the grinding Liquid composition of reference example 4 is an a reference value 1, tries to achieve the relative value of grinding rate of the grinding Liquid composition of each embodiment, comparative example.The result is shown in the table 4 and 5.In addition, except being set at the composition shown in the table 4 and 5, the grinding Liquid composition of all the other and reference example 1 likewise prepares with the grinding Liquid composition of reference example 4.

Table 4

Polishing kit is formed

Match ratio (weight ratio) i/ii/iii/ ion exchange water

pH

Relative grinding rate

i

ii

iii

Embodiment 7

Alpha-alumina (12.75) θ-aluminium oxide (2.56) ammonium sulfate (9.35)

A

H ₂O ₂(2.56)

B

Sulfuric acid (0.8) citric acid (4.28)

C

1∶1∶1∶2

2.0

1.0

Embodiment 8

Alpha-alumina (12.75) θ-aluminium oxide (2.56) sulfuric acid (0.1) ammonium sulfate (9.35)

A

H ₂O ₂(2.56)

B

Sulfuric acid (0.7) citric acid (4.28)

C

1∶1∶1∶2

2.1

1.0

Embodiment 9

Alpha-alumina (12.75) θ-aluminium oxide (2.56)

A

H ₂O ₂(2.56)

B

Sulfuric acid (0.8) citric acid (4.28) ammonium sulfate (9.35)

C

1∶1∶1∶2

2.0

1.0

Embodiment 10

Alpha-alumina (12.75) θ-aluminium oxide (2.56)

A

H ₂O ₂(2.56) ammonium sulfate (9.35)

B

Sulfuric acid (0.8) citric acid (4.28)

C

1∶1∶1∶2

2.0

1.0

Embodiment 11

Alpha-alumina (12.75) θ-aluminium oxide (2.56) ammonium sulfate (9.35)

A

H ₂O ₂(2.56) sulfuric acid (0.8)

D

Citric acid (4.28)

c

1∶1∶1∶2

2.0

1.0

Embodiment 12

A

H ₂O ₂(2.56) sulfuric acid (0.7)

D

Citric acid (4.28)

c

1∶1∶1∶2

2.1

1.0

Embodiment 13

Alpha-alumina (12.75) θ-aluminium oxide (2.56)

A

H ₂O ₂(2.56) sulfuric acid (0.8)

D

Citric acid (4.28) ammonium sulfate (9.35)

c

1∶1∶1∶2

2.0

1.0

Embodiment 14

Alpha-alumina (12.75) θ-aluminium oxide (2.56)

A

H ₂O ₂(2.56) sulfuric acid (0.8) ammonium sulfate (9.35)

D

Citric acid (4.28)

c

1∶1∶1∶2

2.0

1.0

Embodiment 15

Alpha-alumina (12.75) θ-aluminium oxide (2.56) ammonium sulfate (9.35)

A

H ₂O ₂(2.56) sulfuric acid (0.1)

B

Sulfuric acid (0.7) citric acid (4.28)

C

1∶1∶1∶2

2.0

1.0

Embodiment 16

Alpha-alumina (12.75) θ-aluminium oxide (2.56)

A

H ₂O ₂(2.56) sulfuric acid (0.2)

B

Sulfuric acid (0.6) citric acid (4.28) ammonium sulfate (9.35)

C

1∶1∶1∶2

2.0

1.0

Embodiment 17

Alpha-alumina (12.75) θ-aluminium oxide (2.56)

A

H ₂O ₂(2.56) sulfuric acid (0.7) ammonium sulfate (9.35)

D

Sulfuric acid (0.1) citric acid (4.28)

c

1∶1∶1∶2

2.0

1.0

Embodiment 18

Alpha-alumina (12.75) θ-aluminium oxide (2.56) ammonium sulfate (7.0) sulfuric acid (0.1)

A

H ₂O ₂(2.56)

B

Sulfuric acid (0.7) citric acid (4.28) ammonium sulfate (2.35)

C

1∶1∶1∶2

2.1

1.0

Reference example 4

Alpha-alumina (12.75) θ-aluminium oxide (2.56) H ₂O ₂(2.56) sulfuric acid (0.8) citric acid (4.28) ammonium sulfate (9.35)

-

(after preserving, preparing, grinding evaluation immediately) at 60 ℃

1∶-∶-∶4

2.0

1.0

Table 5

Polishing kit is formed

Match ratio (weight ratio) i/ii/ ion exchange water

PH

Relative grinding rate

i

ii

Reference example 4

-

(after preserving, preparing, grinding evaluation immediately) at 60 ℃

1∶-∶4

2.0

1.0

Comparative example 12

Alpha-alumina (12.75) θ-aluminium oxide (2.56) H ₂O ₂(2.56) ammonium sulfate (9.35)

-

Sulfuric acid (0.8) citric acid (4.28)

C

1∶1∶3

2.0

0.64

Comparative example 13

Alpha-alumina (12.75) θ-aluminium oxide (2.56) H ₂O ₂(2.56)

-

Sulfuric acid (0.8) citric acid (4.28) ammonium sulfate (9.35)

C

1∶1∶3

2.0

0.73

Comparative example 14

Alpha-alumina (12.75) θ-aluminium oxide (2.56) ammonium sulfate (9.35)

A

H ₂O ₂(2.56) sulfuric acid (0.8) citric acid (4.28)

-

1∶1∶3

2.2

0.64

Comparative example 15

Alpha-alumina (12.75) θ-aluminium oxide (2.56)

A

H ₂O ₂(2.56) sulfuric acid (0.8) citric acid (4.28) ammonium sulfate (9.35)

-

1∶1∶3

2.2

0.64

Comparative example 16

Alpha-alumina (12.75) θ-aluminium oxide (2.56) sulfuric acid (0.8) citric acid (4.28) ammonium sulfate (9.35)

-

H ₂O ₂(2.56)

B

1∶1∶3

2.6

0.73

Comparative example 17

Alpha-alumina (12.75) θ-aluminium oxide (2.56) sulfuric acid (0.8) citric acid (4.28)

-

H ₂O ₂(2.56) ammonium sulfate (9.35)

B

1∶1∶3

2.6

0.73

Comparative example 18

-

1∶-∶4

2.7

0.55

Shown in the result in the table 4 and 5; Can know; The abrasive composition that the polishing kit of comparative example 12～18 obtains, the grinding rate after 60 ℃ of preservations grinds when estimating the grinding rate of (reference example 4) immediately and compares with processing the back without preservation, reduce significantly.Relative therewith, the grinding rate of grinding Liquid composition after 60 ℃ of preservations that obtains from the polishing kit of embodiment 7～18 is identical with the situation of reference example 4, can repeatability be maintained well.

In addition, the abrasive material to the aluminium alloy base plate that obtained by embodiment 1～18 does not all produce blemish such as cut, surface smoothness is good.

Polishing kit for magnetic disk of the present invention can be used as the manufacturing of high-quality magnetic disc substrates such as hard disk aptly.

The present invention as previously discussed has the scope of many homogeneity significantly.Such diversity is not break away from the intent of the present invention and scope, and persons skilled in the art know that naturally all such changes all are included in the technical scope of appended claim.

Claims

1. polishing kit for magnetic disk; It comprises: contain aluminium oxide slurry (A), contain the oxidant liquid (B) of oxidant and contain acid sour agent liquid (C); Wherein said slurry (A), said oxidant liquid (B) and said sour agent liquid (C) are packed into separately and each component are had the container of the material of patience; The content of the aluminium oxide in the said slurry (A) is 0.1～60 weight %; The content of the oxidant in the said oxidant liquid (B) is 0.005～60 weight %, and the content of the moisture in the said sour agent liquid (C) is more than the 40 weight %.

2. polishing kit for magnetic disk according to claim 1, wherein said aluminium oxide are Alpha-alumina and θ-aluminium oxide, and oxidant is a hydrogen peroxide, and acid is citric acid and sulfuric acid.

3. polishing kit for magnetic disk according to claim 1, wherein said slurry (A) also contains inorganic acid or inorganic acid salt, and the content of inorganic acid is 0.01～5 weight %, and the content of inorganic acid salt is 0.01～30 weight %.

4. polishing kit for magnetic disk according to claim 1, the said acid in the wherein said sour agent liquid (C) is inorganic acid, the content of this inorganic acid is 0.005～60 weight %.

5. polishing kit for magnetic disk according to claim 1, the said acid in the wherein said sour agent liquid (C) is organic acid, this organic acid content is 0.005～60 weight %.

6. polishing kit for magnetic disk; It comprises: contain the slurry (A) of aluminium oxide and contain oxidant and the additive liquid of inorganic acid (D); Wherein said slurry (A) and said additive liquid (D) are packed into separately and each component are had the container of the material of patience; The content of the aluminium oxide in the said slurry (A) is 0.1～60 weight %; The content of the oxidant in the said additive liquid (D) is 0.005～60 weight %, and the content of the inorganic acid in the said additive liquid (D) is 0.005～60 weight %, and the content of the moisture in the said additive liquid (D) is more than the 20 weight %.

7. polishing kit for magnetic disk according to claim 6, wherein said aluminium oxide are Alpha-alumina and θ-aluminium oxide, and oxidant is a hydrogen peroxide, and inorganic acid is a sulfuric acid.

8. polishing kit for magnetic disk according to claim 6, it also comprises and contains organic acid acid agent liquid (c), and the organic acid content in this acid agent liquid (c) is 0.005～60 weight %.

9. polishing kit for magnetic disk according to claim 8, wherein said organic acid is a citric acid.

10. polishing kit for magnetic disk; It comprises: contain the slurry (A) of aluminium oxide and contain sour sour agent liquid (C); And this polishing kit uses with the oxidant liquid (B) that contains oxidant; Wherein said slurry (A), said oxidant liquid (B) and said sour agent liquid (C) are packed into separately and each component are had the container of the material of patience; The content of the aluminium oxide in the said slurry (A) is 0.1～60 weight %, and the content of the oxidant in the said oxidant liquid (B) is 0.005～60 weight %, and the content of the moisture in the said sour agent liquid (C) is more than the 40 weight %.

11. polishing kit for magnetic disk according to claim 10, wherein said aluminium oxide are Alpha-alumina and θ-aluminium oxide, acid is sulfuric acid, and oxidant is a hydrogen peroxide.

12. polishing kit for magnetic disk according to claim 10, the said acid in the wherein said sour agent liquid (C) is inorganic acid, and the content of this inorganic acid is 0.005～60 weight %.

13. polishing kit for magnetic disk according to claim 10, the said acid in the wherein said sour agent liquid (C) is organic acid, and this organic acid content is 0.005～60 weight %.

14. the Ginding process of a magnetic disc substrate; It comprises the steps: the mixed liquor of sour agent liquid (C) that comprises slurry (A), the oxidant liquid (B) that contains oxidant that contains aluminium oxide and contain acid is supplied to the space between magnetic disc substrate and the abrasive cloth; Grind magnetic disc substrate with this mixed liquor; Wherein said mixed liquor is through before grinding, packing into separately each component to be had said slurry (A), said oxidant liquid (B) and said sour agent liquid (C) in the container of material of patience to mix and obtain; The content of the aluminium oxide in the said slurry (A) is 0.1～60 weight %; The content of the oxidant in the said oxidant liquid (B) is 0.005～60 weight %, and the content of the moisture in the said sour agent liquid (C) is more than the 40 weight %.

15. the Ginding process of magnetic disc substrate according to claim 14, the said acid in the wherein said sour agent liquid (C) is inorganic acid, and the content of this inorganic acid is 0.005～60 weight %.

16. the Ginding process of magnetic disc substrate according to claim 14, the said acid in the wherein said sour agent liquid (C) is organic acid, and this organic acid content is 0.005～60 weight %.

17. the Ginding process of a magnetic disc substrate; It comprises the steps: comprising the slurry (A) that contains aluminium oxide and containing oxidant and the mixed liquor of the additive liquid of inorganic acid (D) is supplied to the space between magnetic disc substrate and the abrasive cloth; Grind magnetic disc substrate with this mixed liquor; Wherein said mixed liquor is through before grinding, packing into separately each component to be had said slurry (A) and said additive liquid (D) in the container of material of patience to mix and obtain; The content of the aluminium oxide in the said slurry (A) is 0.1～60 weight %; The content of the oxidant in the said additive liquid (D) is 0.005～60 weight %, and the content of the inorganic acid in the said additive liquid (D) is 0.005～60 weight %, and the content of the moisture in the said additive liquid (D) is more than the 20 weight %.

Contain organic acid acid agent liquid (c) 18. Ginding process as claimed in claim 17, wherein said mixed liquor also comprise, the organic acid content in this acid agent liquid (c) is 0.005～60 weight %.

19. the manufacturing approach of a magnetic disc substrate, it comprises following step:

(1) will contain the slurry (A) of aluminium oxide, the sour agent liquid (C) that contains the oxidant liquid (B) of oxidant and contain acid mixes and prepare the step of grinding Liquid composition; Wherein said mixed liquor is through before grinding, packing into separately each component to be had said slurry (A), said oxidant liquid (B) and said sour agent liquid (C) in the container of material of patience to mix and obtain; The content of the aluminium oxide in the said slurry (A) is 0.1～60 weight %; The content of the oxidant in the said oxidant liquid (B) is 0.005～60 weight %, and the content of the moisture in the said sour agent liquid (C) is more than the 40 weight %;

20. the manufacturing approach of magnetic disc substrate according to claim 19, the said acid in the wherein said sour agent liquid (C) is inorganic acid, and the content of this inorganic acid is 0.005～60 weight %.

21. the manufacturing approach of magnetic disc substrate according to claim 19, the said acid in the wherein said sour agent liquid (C) is organic acid, and this organic acid content is 0.005～60 weight %.

22. the manufacturing approach of a magnetic disc substrate, it comprises following step:

(1) will contain the slurry (A) of aluminium oxide and contain oxidant and the additive liquid of inorganic acid (D) mixes and prepares the step of grinding Liquid composition; Wherein said mixed liquor will be packed into separately before grinding and each component is had said slurry (A) and said additive liquid (D) in the container of material of patience mixed and obtain; The content of the aluminium oxide in the said slurry (A) is 0.1～60 weight %; The content of the oxidant in the said additive liquid (D) is 0.005～60 weight %; The content of the inorganic acid in the said additive liquid (D) is 0.005～60 weight %, and the content of the moisture in the said additive liquid (D) is more than the 20 weight %;

(2) magnetic disc substrate is squeezed in the step of also pressurizeing on the abrasive cloth of grinding plate; And

23. the manufacturing approach of a magnetic disc substrate, it comprises following step:

(1) will contain aluminium oxide slurry (A), contain the additive liquid (D) of oxidant and inorganic acid and contain that organic acid acid agent liquid (c) mixes and the step for preparing grinding Liquid composition; Wherein said mixed liquor will be packed into separately each component had to mix in said slurry (A), said additive liquid (D) and the said sour agent liquid (c) in the container of material of patience before grinding and obtained; The content of the aluminium oxide in the said slurry (A) is 0.1～60 weight %; The content of the oxidant in the said additive liquid (D) is 0.005～60 weight %; The content of the inorganic acid in the said additive liquid (D) is 0.005～60 weight %; The content of the moisture in the said additive liquid (D) is more than the 20 weight %, and the organic acid content in the said sour agent liquid (c) is 0.005～60 weight %;