JP2000246187A - Sponge roller for cleaning - Google Patents

Abstract

(57) [Problem] To provide a PVAt-based cleaning sponge roller capable of improving durability without impairing cleaning performance. SOLUTION: A cleaning sponge roller 1 is made of a polyvinyl acetal-based porous material having elasticity in a wet state, and has a substantially cylindrical roll body 3 and a plurality of integrally formed outer peripheral surfaces 3a of the roll body 3. The projection has a projection, and the top portion of the projection is brought into rotational contact with the object to be cleaned to clean the object. The protrusion 5 includes a projecting base 11 extending from the outer peripheral surface 3 a of the roll body 3 and tapering, and a tip end surface 1 of the projecting base 11.
And a projecting end 13 having substantially the same cross-sectional shape from 1b to the top 5a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for manufacturing a substrate such as an aluminum disk for magnetic recording, a semiconductor silicon wafer or the like.
The present invention relates to a cleaning sponge roller capable of removing fine particles, such as polishing debris, attached to the surface of an object to be cleaned extremely efficiently and without damaging the surface of the object to be cleaned.

[0002]

2. Description of the Related Art In a manufacturing process of a hard disk, a glass disk, a silicon wafer, a semiconductor element in a CMP process, or a photomask, a liquid crystal glass substrate, etc., silicon oxide, silicon oxide, High-precision polishing using various abrasive grains such as alumina and cerium, so-called polishing is performed. The surface of the polished object such as a hard disk or a silicon wafer that has been polished is contaminated by abrasive grains and polishing debris. Therefore, it is necessary to sufficiently clean the surface before performing the next process.

As a method for cleaning a silicon wafer, RCA cleaning using a mixed solution of ammonia water and hydrogen peroxide, a mixed solution of dilute hydrofluoric acid, hydrochloric acid and hydrogen peroxide water in this order is known. In the cleaning of a hard disk, a silicon wafer or the like after the polishing step, there is known a method using a polyvinyl acetal (hereinafter abbreviated as PVAt) porous material as a raw material and using a cleaning sponge roller having a plurality of projections on an outer surface. Have been. Specifically, the top of the projection of the sponge roller is brought into rotational contact with the cleaning surface of the object to be cleaned. As a result, the cleaning surface is brushed by the protrusions,
The object to be cleaned is well cleaned.

[0004]

The projection of the sponge roller during cleaning frequently repeats a deformation state in which the sponge roller is laterally pressed by the object to be cleaned and a state in which the deformation is released from the object to be cleaned. Brushing. At this time, the tensile force acting on the projection concentrates on the base end of the projection, and the vicinity of the base end of the projection is greatly deformed. For this reason, the vicinity of the base end of the projection is easily cut. Further, since the entire sponge roller is integrally formed, the sponge roller needs to be replaced when a large number of projections are cut.

[0005] Such a problem can also be solved by forming the whole protrusion large and increasing its strength. However, if the entire protrusion is formed to be large, a desired brushing effect cannot be obtained, and the cleaning effect may be reduced.

Accordingly, an object of the present invention is to provide a PVAt-based cleaning sponge roller capable of improving durability without impairing cleaning performance.

[0007]

In order to achieve the above object, the present invention provides a polyvinyl acetal porous material having elasticity in a wet state, comprising a substantially cylindrical roll body and an outer circumferential surface of the roll body. A plurality of projections formed integrally with the cleaning body, and a cleaning sponge roller for cleaning the body to be cleaned by rotating the top of the projection to the body to be cleaned. A protruding base extending from the surface and tapering, and a protruding end having substantially the same cross-sectional shape from the tip of the protruding base to the top are provided.

The projecting base may be substantially frustoconical, and the projecting end may be substantially columnar.

In the above construction, the projecting base of the projection has an outer surface formed so as to diverge toward the outer peripheral surface of the roll body, and the sectional area of the projecting base is a base end (the outer peripheral surface of the roll body and the projecting base). At the boundary) and gradually decreases toward the protruding end. Therefore, when the protrusion is pressed in the lateral direction, stress concentration near the base end of the protruding base where the tensile force is concentrated is reduced, and the deformation is dispersed throughout the protruding base, thereby improving the durability of the protrusion.

In addition, since the durability of the projection can be improved without affecting the shape of the protruding end portion, the protruding end portion that comes into contact with the object to be cleaned can be freely set to an optimal size and shape for brushing. be able to.

A cleaning sponge roller composed of a polyvinyl acetal porous sponge is obtained by reacting a viscous mixture containing raw materials in a mold. The mold corresponding to the sponge roller having the above configuration has a first space for forming a roll body and a plurality of second spaces for forming projections. Each second space has a base forming space communicating with the first space to form a projecting base, and an end forming space communicating with the base forming space to form a projecting end. The base forming space has an inclined surface extending from the end forming space toward the first space. In manufacturing the sponge roller, the mixed liquid is injected into the first space,
It flows into each second space from the space. At this time, since the base forming space of the second space has an inclined surface extending toward the first space, the mixed liquid is guided by the inclined surface of the base forming space and smoothly flows into the end forming space. At the same time, the air in the second space smoothly moves from the end forming space to the first space,
Released from the first space to the atmosphere. Thereby, the mixed liquid is reliably filled up to the end of the second space, and the production cost can be reduced by improving the yield.

The height from the outer peripheral surface of the roll body to the tip of the protruding base is preferably 以下 or less of the height of the projection, and more preferably ５ or more.

The height of the protruding base is １ ／ of the height of the entire protrusion.
If it exceeds, the amount of deformation of the protruding end may be kept small and the brushing effect at the time of cleaning may be insufficient. If it is less than 1/5, sufficient strength may not be obtained. It is because there is.

It is preferable that the crossing angle between a straight line connecting the base end and the front end of the outer surface of the protruding base portion at an arbitrary cross section and the outer peripheral surface of the roll body is 30 ° or more and 60 ° or less.

If the crossing angle is less than 30 °, the protruding base portion widens greatly toward the outer peripheral surface, the area of the lower end surface of the protruding base portion increases, and the total number of protrusions that can be formed on the outer peripheral surface of the roll body. If the crossing angle exceeds 60 °, sufficient strength may not be obtained.

Further, the outer surface of the protruding base may be a straight inclined surface or a curved inclined surface.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a partial cross-sectional view showing the entire cleaning sponge roller according to the first embodiment of the present invention, and FIG.
FIG. 3A is an enlarged perspective view showing a projection of the sponge roller of FIG.
(C) is a sectional view of (b).

The cleaning sponge roller 1 is made of a polyvinyl acetal porous material (PV) having elasticity in a water-containing state.
At-based porous material). The PVAt porous material hardens in a dry state and softens in a wet state. In addition, it is excellent in water absorbency and water retention, exhibits favorable flexibility and appropriate rebound resilience when wet, and has excellent abrasion resistance.

As shown in FIG. 1A, the sponge roller 1 has a substantially cylindrical roll body 3 and a plurality of projections 5 integrally formed on the outer peripheral surface 3a of the roll body 3.

As shown in FIGS. 1B and 1C, the protrusion 5
Has a protruding base portion 11 integrally protruding from the outer peripheral surface 3a of the roll body 3 and a protruding end portion 13 integrally extending from a distal end surface 11b of the protruding base portion 11. The base end face 11 a of the protruding base 11 is included in the outer peripheral face 3 a of the roll body 3. The distal end face 11b of the protruding base 11 and the proximal end face 13a of the protruding end 13
Matches almost perfectly. The protruding base 11 has an inclined surface (outer surface) 15 formed linearly and divergently toward the outer peripheral surface 3 a of the roll body 3.

The protruding base 11 is formed in a substantially frustoconical shape tapering from the base end face 11a to the tip end face 11b. The height h from the base end face 11a to the tip end face 11b of the protruding base 11 is equal to the height of the projection 3 (the base end face 11 of the protruding base 11).
a) to the tip surface 13a of the projecting tip 13)
It is set in the range of / 5 or more and 1/2 or less. FIG.
As shown in (c), in an arbitrary cross section, a straight line 17 connecting the base end 15a and the tip end 15b of the inclined surface 15 is the inclined surface 1
5, and the intersection angle θ ₁ between the straight line 17 and the outer peripheral surface 3 a of the roll body 3 is set in a range of 30 ° or more and 60 ° or less.

The protruding end portion 13 is provided on the outer peripheral surface 3a of the roll body 3.
, And is formed in a substantially columnar shape having substantially the same cross-sectional shape from the base end face 13a to the tip end face 13b. The distal end surface 13 b of the protruding end 13 intersects substantially perpendicularly with the outer peripheral surface of the protruding end 13.

The cleaning sponge roller 3 is, for example, an aqueous solution obtained by mixing one or more polyvinyl alcohols (raw materials) having an average degree of polymerization of 300 to 2000 and a saponification degree of 80% or more. Mineral acids are added as a catalyst, and starch and the like are added as a pore-forming material. A mixture of these is poured into a mold 21 as shown in FIG.
It is obtained by removing the pore-forming material by washing with water after reacting at 0 to 80 ° C. and taking out from the mold 21.

The mold 21 includes an outer mold 23, an inner mold 25, and a bottom plate 27.
And a core rod 29 and a cap 31. The outer mold 23 and the inner mold 25 are both formed in a cylindrical shape. The inner mold 25 is
It has an outer diameter equal to or slightly smaller than the inner diameter of the outer mold 23 and is inserted into the outer mold 23. The core rod 29 is inserted substantially at the center of the inner mold 25. The bottom plate 27 closes the lower ends 23a and 25a of the outer die 23 and the inner die 25, and
9 supports the lower end 29a. The cap 31 is the outer mold 23
On the inner peripheral surface of the upper end 23b. The core rod 29 is positioned by the bottom plate 27 and the cap 31.

As shown in FIG. 3, a substantially cylindrical first space 33 for forming the roll body 3 is defined between the inner peripheral surface of the inner die 25 and the outer peripheral surface of the core rod 29. . The inner die 25 has a plurality of through holes (second spaces) 35 for forming the protrusions 5. Each through hole 35 has a base forming space 37 communicating with the first space 33 and forming the protruding base 11, and an end forming space 39 communicating with the base forming space 37 and forming the protruding end 13. The base forming space 37 includes an inclined surface 41 extending from the end forming space 39 toward the first space 33.
Having.

The mixed liquid is injected into the first space 33 from the casting nozzle 43 inserted between the outer mold 23 and the cap 31, and flows from the first space 33 into each through hole 35. At this time, the mixed liquid is supplied to the inclined surface 4 spreading toward the first space 33.
1 and smoothly flows into the end forming space 39. At the same time, the air in the through hole 35 smoothly moves from the end forming space 39 to the first space 33 and is discharged from the upper end of the first space 33 to the atmosphere. As a result, the mixed liquid is reliably filled up to the end of the through-hole 35 (end forming space 39). Therefore, the yield is improved and the manufacturing cost is reduced.

As the PVAt porous material, a material having a 30% compressive stress of 15 g / cm ² or more and 150 g / cm ² or less in a proper water-containing state is preferable. The proper water-containing state refers to a water-containing state in which the PVAt-based porous material can exhibit proper elasticity, and the water content (weight% of the water-containing state relative to the dry state) is obtained in a range of about 100% to 1000%. The term “30% compressive stress” refers to a value obtained by cutting a PVat-based porous material in an appropriate water-containing state so that the distance between both end faces (height in the longitudinal direction) is 30 mm and applying a load to the entire end face. It is set in a formula load measuring device, and the load when crushed by 30% (9 mm) in the longitudinal direction is measured.
It is obtained as a value obtained by dividing the load by the area of the end face.

[0029] The upper limit of the preferred range of 30% compression stress in the proper moisture state was 150 g / cm ^2, this value is 150 g / cm ² greater than PVAt based porous material is required to brushing too hard This is because they do not exhibit elasticity. Conversely, the lower limit of the preferred range of 30% compression stress in the proper moisture state was 15 g / cm ^2, this value is 15 g / cm ² less than PVAt based porous material, rotating the roll body 3 too soft This is because distortion occurs in the case of performing.

As the PVAt-based porous material, those having a porosity of 85% or more and 95% or less and an average pore diameter of 10 μm or more and 200 μm or less are preferable.

When the porosity is less than 85%, the flexibility when wet becomes insufficient, and when the porosity is more than 95%, the practical strength is poor, and neither is suitable for cleaning use. . On the other hand, if the average pore diameter is smaller than 10 μm, the elasticity at the time of wetting is insufficient, so that a sufficient brushing effect cannot be obtained. If the average pore diameter exceeds 200 μm, the mesh is too coarse and unsuitable for precision cleaning.

The porosity as used herein means the porosity of a rectangular parallelepiped PVAt porous material which has been sufficiently dried by a drier, is measured by a dry automatic timepiece, and the apparent volume and the true volume of the rectangular parallelepiped are calculated by the following equation. This is the value calculated in (1).

Porosity (%) = (apparent volume−true volume) / apparent volume × 100 (1) The average pore diameter is ASTM (Desiratio).
n: D4404-84), specifically, a value determined by mercury intrusion porosimetry using a mercury porosimeter manufactured by PORUS MATERIALS, INC.

Next, the cleaning using the sponge roller 1 will be described.

As shown in FIG. 4, a rotating shaft 7 is inserted into a hollow portion of the sponge roller 1, and the roll body 3 is fixed to the rotating shaft 7. The object 9 to be cleaned is cleaned
This is performed by bringing the top 5 a of the projection 5 that rotates with the rotation of the cleaning object 9 into contact with the cleaning surface 9 a of the cleaning target 9. Protrusion 5
Is formed by a tip portion including a tip surface 13 b of the protruding end portion 13. The top 5a of the projection 5 is deformed in a lateral direction by the body 9 to be cleaned (see FIG. 5).
And the state where the deformation is released from the object 9 to be cleaned is frequently repeated, and the cleaning surface 9a is brushed. Due to the brushing action of the projections 9, the body 9 to be cleaned is satisfactorily cleaned.

Here, as shown in FIG. 6, a sponge roller 51 having a substantially cylindrical projection 53 having substantially the same cross-sectional shape from the base end surface 53a to the front end surface 53b on the outer peripheral surface 3a of the roll body 3 is used. In this case, the tensile force acting on the projection 53 in contact with the cleaning surface 9a concentrates on the base end surface 53a,
The vicinity of the base end face 53a is largely deformed locally. In addition, since the outer peripheral surface 3a is not a perfect plane but is inclined in an arc shape toward the side opposite to the projection direction of the projection 53, the outer peripheral surface 3a is deformed in the lateral direction as compared with the case where the outer peripheral surface 3a projects from the perfect plane. easy. Therefore, the front end portion 55 of the base end face 53a in the moving direction
Are easily cut.

On the other hand, even when the sponge roller 1 of this embodiment is used, as in the case of FIG. 6, the tensile force acting on the projection 5 in contact with the cleaning surface 9a is maintained at the base end of the projection 5 (of the projection base 11). Concentrate on the proximal face 11a). However, as shown in FIG. 5, the protruding base 11 has an outer surface 15 formed so as to diverge toward the outer peripheral surface 3 a of the roll body 3, and the cross-sectional area of the protruding base 11 is maximum at the base end surface 11 a. Since the protrusion 5 gradually decreases toward the protruding end portion 13, when the protrusion 5 is pressed in the lateral direction, the stress concentration in the vicinity of the base end surface 11a where the tensile force is concentrated is reduced. Therefore, the deformation is dispersed over the entire area of the protruding base 11, and cutting near the front end 45 in the moving direction of the base end face 11a is reliably prevented, and the durability of the projection 5 is improved.

Further, since the durability of the projection 5 can be improved without affecting the shape of the protruding end portion 13, the protruding end portion 13 which comes into contact with the cleaning object 9 is formed into a shape and a shape optimal for brushing. Can be set freely.

As described above, according to this embodiment, when the top 5a of the projection 5 comes into contact with the body 9 to be cleaned and the projection 5 is pressed in the lateral direction, the base end face 11a of the projection base 11 is formed.
Is reduced, the deformation is distributed over the entire area of the protruding base 11, and the durability of the projection 5 is improved.

Further, since the durability of the projection 5 can be improved without affecting the shape of the protruding end portion 13, the protruding end portion 13 which comes into contact with the cleaning object 9 is formed into a shape and a shape optimal for brushing. The protrusion 5 can be freely set, and the durability of the projection 5 can be improved without impairing the cleaning performance.

The mold 21 into which the mixed liquid is injected when the sponge roller 1 is manufactured has a first space 33 for forming the roll body 3, a base forming space 37 for forming the projecting base 11, and a projecting end 13. And a through-hole 35 for forming the projection 5 including an end forming space 39 to be formed.
It has an inclined surface 41 extending toward the first space 33. The mixed liquid injected into the first space 33 is guided by the inclined surface 41 and smoothly flows into the end forming space 39, and the air in the through hole 35 is smoothly moved from the end forming space 39 to the first space 33. And released to the atmosphere. Therefore, the mixed liquid is supplied to the through hole 35.
Is reliably filled up to the closed end, and the production cost can be reduced by improving the yield.

Next, a description will be given of a tensile strength experiment for the projection 5 (target sample) of the sponge roller 1 as shown in FIG. 1B and the projection 53 (comparative sample) of the sponge roller 51 as shown in FIG. I do.

Each of the target sample and the comparative sample had a porosity of 90%, an average pore diameter of 130 μm, and a 30% compressive stress in a proper water-containing state of 60 g / cm ^2.
An At-based porous material was used.

The protrusion 5 of the target sample has a total height H of 4.5 mm, an outer diameter of the protruding end 13 of 7.5 mm, a height h of the protruding base 11 of 1.5 mm, and the intersection of the inclined surface 11 with the outer surface 3a. The angle θ is about 45 ° (the base end face 1 of the protruding base 11).
The outer diameter of 1a was 10.5 mm), and the protrusion 53 of the comparative sample used had a total height of 4.5 mm and an outer diameter of 7.5 mm.

In the experiment, the projections 5 and 53 were sandwiched by clips (not shown) while the roll body 3 of each sample was held by a chuck (not shown), and the clips were pulled to the limit at which the projections 5 and 53 would be cut. Then, the tensile strength was measured.

As shown in FIG. 8, the results of the experiment show that the tensile strength of the comparative sample was 1.59 kg, the tensile strength of the target sample was 1.85 kg, and the tensile strength of the target sample was 16. It was confirmed that it increased by 4%.

Next, a second embodiment of the present invention will be described.

FIG. 7 is an enlarged sectional view of a main part showing a projection 63 of a PVAt-based cleaning sponge roller 61 according to the present embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The protrusion 63 of the present embodiment is
Has a curved outer surface 67, and a point that a curved surface portion 69 is provided between the outer peripheral surface of the protruding end portion 13 and the distal end surface 13b, which is different from the first embodiment.

In the cross section shown in FIG. 7, the crossing angle θ ₂ between the straight line 75 connecting the base end 71 and the front end 73 of the outer surface 67 of the projecting base 65 and the outer peripheral surface 3a of the roll body 3 is 30 ° or more and 6 ° or more.
It is set to 0 ° or less.

According to the present embodiment, similarly to the first embodiment, the durability of the projection 63 can be improved without impairing the cleaning performance, and the manufacturing cost can be reduced by improving the yield. it can.

The projecting bases 11 and 65 and the projecting end 1
Regarding the cross-sectional shape of No. 3, the first and second embodiments have been described as having a substantially circular shape. However, the present invention is not limited to this, and the cross-sectional shape may be various shapes such as a rectangle, an ellipse, and an oval. The shape can be set.

[0053]

As described above, according to the present invention,
When the top of the projection comes into contact with the object to be cleaned and the projection is pressed in the lateral direction, stress concentration near the base end of the projection base is eased, so that the deformation is dispersed throughout the projection base and the durability of the projection is improved. I do.

In addition, since the durability of the projection can be improved without affecting the shape of the protruding end portion, the protruding end portion that comes into contact with the object to be cleaned can be freely set to the optimal size and shape for brushing. Thus, the durability of the projections can be improved without impairing the cleaning performance.

Further, the mold into which the mixed liquid is injected at the time of manufacturing the sponge roller has a first space for forming the roll body, a base forming space for forming the protruding base, and an end forming space for forming the protruding end. And a second space for forming a projection including the second space, and the base forming space has an inclined surface extending toward the first space. The mixed liquid injected into the first space is guided by the inclined surface and smoothly flows into the end forming space, and the air in the space moves smoothly from the end forming space to the first space and is discharged to the atmosphere. Is done. Therefore, the mixed liquid is reliably filled up to the end of the second space, and the production cost can be reduced by improving the yield.

[Brief description of the drawings]

1A is a partial cross-sectional view showing a cleaning sponge roller according to a first embodiment of the present invention, FIG. 1B is an enlarged perspective view showing a projection of the sponge roller of FIG. 1A, and FIG. It is sectional drawing of (b).

FIG. 2 is a perspective view showing a mold for molding the sponge roller of FIG. 1 with a part cut away.

FIG. 3 is a cross-sectional view illustrating a method of manufacturing the sponge roller of FIG.

FIG. 4 is a side view schematically showing a use state of the sponge roller of FIG. 1;

FIG. 5 is an enlarged view of a main part of FIG. 4;

FIG. 6 is an enlarged view of a main part showing a use state of a projection to be compared.

FIG. 7 is a cross-sectional view illustrating a projection of a sponge roller according to a second embodiment of the present invention.

FIG. 8 is a graph showing the results of a comparative experiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning sponge roller 3 Roll body 3a Outer peripheral surface of roll body 5 Projection 11 Projection base 11a Base end surface of projection base 11b Tip end surface of projection base 13 Projection end 13a Base end surface of projection end 13b Tip end surface of projection end 15 Outer surface of protruding base 61 Sponge roll for cleaning 63 Protruding base 67 Outer surface of protruding base

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[Procedure amendment]

[Submission date] March 31, 1999 (1999.3.3)
1)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Claims (3)

[Claims] 1. A roll made of a polyvinyl acetal porous material having elasticity in a wet state, comprising a roll having a substantially cylindrical shape and a plurality of protrusions integrally formed on an outer peripheral surface of the roll. A cleaning sponge roller for cleaning the cleaning target by bringing the top of the cleaning target into rotary contact with the cleaning target, wherein the protrusion extends from an outer peripheral surface of the roll body and tapers, and a tip of the projection base. And a protruding end having substantially the same cross-sectional shape from the top to the top. 2. The cleaning sponge roller according to claim 1, wherein the protruding base is formed in a substantially truncated cone shape, and the protruding end is formed in a substantially columnar shape. Cleaning sponge roller. 3. The cleaning sponge roller according to claim 1, wherein a height from an outer peripheral surface of the roll body to a tip of the protrusion base is equal to or more than 以上 of a height of the protrusion. The intersection angle between a straight line connecting the base end and the front end of the outer surface of the protruding base in an arbitrary cross section and the outer peripheral surface of the roll body is 30.
A cleaning sponge roller characterized by being at least 60 ° and at most 60 °.