U.S. patent application number 10/493121 was filed with the patent office on 2004-10-21 for abrasive material.
Invention is credited to Hara, Fujio, Suzuki, Kazuo.
Application Number | 20040209561 10/493121 |
Document ID | / |
Family ID | 33161430 |
Filed Date | 2004-10-21 |
United States Patent
Application |
20040209561 |
Kind Code |
A1 |
Suzuki, Kazuo ; et
al. |
October 21, 2004 |
Abrasive material
Abstract
Abrasive materials having a sheet-form mesh substrate, a metal
film plated on a surface of the substrate, a binder applied on a
surface of the metal film, and abrasive grains bonded to the
substrate by the binder are reported.
Inventors: |
Suzuki, Kazuo; (Sagamihara,
JP) ; Hara, Fujio; (Tokyo, JP) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Family ID: |
33161430 |
Appl. No.: |
10/493121 |
Filed: |
April 19, 2004 |
PCT Filed: |
November 13, 2002 |
PCT NO: |
PCT/US02/36330 |
Current U.S.
Class: |
451/527 |
Current CPC
Class: |
D04B 21/00 20130101;
B24D 15/04 20130101; B24D 11/02 20130101; B24D 3/004 20130101 |
Class at
Publication: |
451/527 |
International
Class: |
B24D 011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2001 |
JP |
2001-347534 |
Claims
1-8. canceled
9. An abrasive material comprising a sheet-form mesh substrate, a
metal film plated on a surface of said substrate, a binder applied
on a surface of said metal film; and abrasive grains bonded to the
substrate by the binder.
10. The abrasive material according to claim 9, wherein the
substrate and the metal film comprise knitted metal-plated flat
strings.
11. The abrasive material according to claim 9, wherein the
substrate and the metal film comprise a metal-plated net of flat
polymer material.
12. The abrasive material according to claim 9, wherein the
abrasive grains are applied to the substrate using an electrostatic
spray coating method.
13. The abrasive material according to claim 9, wherein the metal
is selected from the group consisting of aluminum, copper, silver,
gold, and chromium.
14. The abrasive material according to claim 9, wherein the
substrate comprises knitted flat strings or a net of flat polymer
material.
15. The abrasive material according to claim 14, wherein the flat
strings or polymer net has a flat coefficient of 5 or more.
16. An abrasive material comprising a sheet-form mesh substrate, a
metal film plated on a surface of said substrate, a binder applied
on a surface of said metal film, and abrasive grains bonded to the
substrate, wherein the grains are applied to the substrate using an
electrostatic spray coating method.
17. The abrasive material according to claim 16. wherein the
substrate and the metal film comprise knitted metal-plated flat
strings.
18. The abrasive material according to claim 16. wherein the
substrate and the metal film comprise a metal-plated net of flat
polymer material.
19. The abrasive material according to claim 16, wherein the metal
is selected from the group consisting of aluminum, copper, silver,
gold, and chromium.
20. The abrasive material according to claim 16, wherein the
substrate comprises knitted flat strings or a net of flat polymer
material.
21. The abrasive material according to claim 20, wherein the flat
strings or polymer net has a flat coefficient of 5 or more.
Description
FIELD
[0001] The invention relates to abrasive materials used for
abrading surfaces, for example, metals, ceramics, resins and the
like.
BACKGROUND
[0002] Various kinds of abrasive materials for abrading tableware,
pans and the like in a kitchen or the like are known. For example,
an abrasive scrub brush using a sponge, cloth, nonwoven cloth or
the like as a substrate, on which abrasive grains are fixed by a
binder resin is generally known. Such an abrasive scrub brush is
commercially available, for example, from 3M Company under the
trade designation "SCOTCH-BRITE".
[0003] Japanese Patent Laid-Open Publication No. Hei 5-220670
discloses an abrasive nonwoven cloth in which a nonwoven cloth
containing synthetic fibers having a flat coefficient of more than
or equal to 5 is used as a substrate, and abrasive grains are
adhered on a surface and intermingle portions of fiber constituting
the nonwoven cloth.
[0004] Sponge, cloth, nonwoven cloth and the like have excellent
flexibility, so that an abrasive scrub brush using such material as
a substrate is good at abrading uneven surfaces of metal, ceramic
and resin products.
[0005] In these conventional abrasive scrub brushes, however,
fixing of abrasive grains to the substrate is not satisfactory, so
that the abrasive grains are likely to come off and hence the
service life of product is short. Furthermore, since distribution
of the abrasive grains is uneven, and the abrasive grains are fixed
mainly to cell walls of sponge or intersections of fiber, the
abrasive tooth becomes coarse. Furthermore, since cell walls of
sponge and portions between intersections of nonwoven cloth move
comparably freely at the time of abrading operation, so that the
abrasive efficiency is poor.
[0006] Another abrasive material is reported in Japanese Patent
Opened Publication No. Hei 8-502695 which reports a coated abrasive
material using a nonwoven cloth containing conductive fibers and
conductive particles as a substrate for the purpose of effectively
removing static electricity generated at the time of abrading
process. However, this coated abrasive material is intended for
wood working, and hence is not suited for use as an abrasive scrub
brush.
[0007] Japanese Utility Model Laid-Open Publication No. Hei 6-66555
reports a product wherein metal flat lines are woven into a net
cloth to produce a scrub brush. This scrub brush, however, does not
bear abrasive grains so that the abrasive performance is poor.
SUMMARY
[0008] The present invention provides an abrasive material that has
a long service life and fine abrasive tooth that is superior in
abrasive efficiency.
[0009] In one embodiment the abrasive material comprises a
sheet-form mesh substrate, a metal film plated on a surface of said
substrate, a binder applied on a surface of said metal film; and
abrasive grains bonded to the substrate by the binder.
[0010] In at least one embodiment the substrate and the metal film
may comprise knitted metal-plated flat strings or a metal-plated
net of flat polymer material. Preferably, the flat strings or net
of flat polymer material has a flat coefficient of 5 or more.
[0011] In another embodiment the abrasive grains are applied to the
substrate using an electrostatic spray coating method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic cross section view that shows the
principle of an electrostatic coating method.
[0013] FIG. 2 is an enlarged digital image (.times.35) showing the
state that abrasive grains are applied on the surface of the fiber
constituting the substrate by the electrostatic spray coating
method.
[0014] FIG. 3 is an enlarged digital image (.times.100) showing the
state that abrasive grains are applied on the surface of the fiber
constituting the substrate by the electrostatic spray coating
method.
[0015] FIG. 4 is a schematic drawing that shows an outline of a
coating device using the electrostatic spray coating method.
DETAILED DESCRIPTION
[0016] The present invention provides an abrasive material having a
mesh sheet-form substrate, a metal film plated on a surface of the
substrate, a binder applied on a surface of the metal film, and
abrasive grains bonded to the substrate by the binder.
[0017] Sheet-Form Substrate
[0018] The sheet-form substrate is composed of fiber or polymer and
has a plurality of through holes over the entire substrate. The
holes are of such a size that a boundary with respect to the
remaining portion of the substrate can be clearly confirmed, and
the holes form a mesh structure in the substrate.
[0019] The substrate has mesh structure to avoid deterioration of
abrasive performance due to clogging of the abrasive material or
adsorption of the abrasive material onto a surface to be abraded.
Furthermore, efficiency in use of the abrasive grains is improved
compared to a non-mesh substrate thereby improving abrasive
efficiency.
[0020] The above-mentioned substrate having mesh structure is
further metallized. When a substrate is "metallized", it means that
the substrate has a metal film plated on a surface of fiber or
polymer making up the substrate. By interposing a metal film
between the fiber or polymer making up the substrate and the
binder, fixing power of abrasive grains by the binder is
significantly improved. In this way, the abrasive grains are less
likely to come off during abrading operation, thereby improving
durability and prolonging the abrasive durability improves, and the
service life of the abrasive material.
[0021] Furthermore, in the case where abrasive grains are applied
by electrostatic spray coating method, the application efficiency
of abrasive grains significantly improves because of the existence
of the metal film. As a result of this, the distribution of the
abrasive grains adhered to the substrate is even and close, the
abrasive tooth is fine, and also the abrasive efficiency is
improved.
[0022] The substrate may be formed of a fiber material or a polymer
material. As the fiber material or the polymer material, synthetic
fibers such as polyester fibers, polyamide fibers, polyvinyl
alcohol fibers, polypropylene fibers and polyvinyl chloride fibers,
and polyethylene fibers; natural fibers such as cotton, hemp, silk
and wool; and inorganic fibers such as glass fiber, rock fiber may
be used. The fibers may be twisted or untwisted.
[0023] In the case where the substrate is formed of a fiber
material, the substrate is preferably formed by knitting long
fibers. This provides advantages in shaping fiber materials into a
sheet form, forming a uniform mesh structure, and obtaining a
sufficiently strong substrate.
[0024] The fibers making up the substrate are preferably strings
having a compressed cross section shape. This is because such a
string allows the abrasive grains to adhere easily as compared to a
string having a circular cross section shape, thereby improving the
efficiency in use of the abrasive grains.
[0025] Preferably, the flat coefficient of the string is 5 or more.
If the flat coefficient of the string is less than 5, no
significant difference is provided as compared to the case where a
string having a circular cross section shape is used. The term
"flat coefficient" refers to the ratio between the long side and
the short side of a cross section of the string.
[0026] Knitting of long fibers may be carried out by hand knitting
or machine knitting commonly used a knitting machines (e.g., a
Raschel loom) or a tricot machine may be used.
[0027] When the flat string has a size in cross-section of 10 .mu.m
to 30 .mu.m for the short side, and 0.1 .mu.m to 1.0 mm for long
side, the knitting gauge is usually 5 gauge to 35 gauge, preferably
12 gauge to 18 gauge, and knitting course is usually 20 course to
60 course, preferably 35 course to 42 course. The term "knitting
gauge" refers to the number of vertical strings per inch, and the
term "knitting course" refers to the number of horizontal strings
per inch.
[0028] A net formed of a polymer material such as polyester,
polyamide, polyvinyl alcohol may also be used as a substrate. The
net can be formed by, for example, combining polymer filaments in
matrix to form a mesh structure and adhering by pressing from above
and below under pressure. The net formed in this manner is flat in
shape (i.e., collapsed in the vertical direction) so that it is
particularly preferred for used as a substrate.
[0029] The net is designed so that an average length and an average
width of each mesh opening are respectively in the range of 0.1 mm
to 10 mm, preferably in the range of 0.5 mm to 3 mm, the width
(so-called long side) of a filament is 0.01 mm to 1 mm, preferably
0.05 mm to 0.3 mm, and the thickness (so-called short side) is 0.01
mm to 0.2 mm, preferably 0.02 mm to 0.1 mm. Furthermore, it is
preferable that the flat coefficient of a filament is more than or
equal to 5.
[0030] The metal film may be formed on a surface of the substrate
by plating. Alternatively, metal-plated strings may be knitted to
form a metallized substrate. The metal to be plated include, for
example, aluminum, copper, silver, gold, chromium and the like.
Aluminum or copper is preferable from the view of the cost.
[0031] With regard to a method of plating, dry plating such as
vapor deposition or spattering may be used. The thickness of the
metal film can be 0.1 .mu.m to 10 .mu.m, preferably 0.3 .mu.m to 5
.mu.m. After forming the metal film, a resin, such as a modified
melamine resin may, be applied on the metal film for the purpose of
preventing surface oxidation and otherwise protecting the
surface.
[0032] In a preferred embodiment, a metallized substrate is formed
by knitting metal-plated flat strings. The metal-plated flat
strings are formed by forming metal films on the front and back
surfaces of a synthetic resin film via dry plating, and cutting the
resulting sheet into a predetermined width.
[0033] With regard to a synthetic resin sheet, a film of polymer
materials recited above can be used. A polymer material that is
preferable from the view point of the cost and strength is
polyester. The thickness of the film is not especially limited, but
is generally 5 .mu.m to 50 .mu.m in consideration of flat
coefficient and ease of knitting.
[0034] Cutting of the metal-plated synthetic resin film may be
achieved by conventional techniques. The width of the flat fiber is
0.1 mm to 2 mm in consideration of flat coefficient and ease of
knitting. The metal-plated flat fiber is commercially available in
the name of so-called rame strings, which may be used
alternatively. It is preferred that the method of knitting is
Mackyzett knitting using a Raschel loom.
[0035] Another example of the metallized substrate is a sheet
material wherein a metal film is formed on a surface of a polymer
net. Such a sheet material is commercially available, for example,
from Aion Company under the trade designation "TOUGH-BELL".
[0036] Abrasive Grain
[0037] With regard to abrasive grain, those commonly used for the
application such as abrasive scrub brush are used. Examples of
abrasive materials include aluminum oxide, cerium oxide, silicon
carbide, diamond and the like. Also, the abrasive grains may be
plastic micrograins formed of poly(methyl methacrylate),
polystyrene, polyolefin and the like.
[0038] The size of abrasive grains is generally an average grain
size of from 1 .mu.m (#8000) to 40 .mu.m (#360), and preferably an
average grain size of from 2 .mu.m (#6000) to 30 .mu.m (#600).
[0039] Binder
[0040] With regard to a binder, those commonly used for application
such as abrasive scrub brushes are used. Examples of materials
include phenol resin, urethane resin, melamine resin, urea resin,
acryl resin, polyester resin, epoxy resin, styrene resin, vinyl
resin and the like.
[0041] By fixing the abrasive grains and the metallized substrate
with the use of the biner as described above, removal of the
abrasive grains, movement of the fiber and abrasion are prevented.
As a consequence of this, an abrasive sheet that is superior in
abrasive performance and has a long service life is obtained. In
particular, by using a binder having stiffness and flexibility
(e.g., phenol resin, epoxy resin, or urethane resin) the abrasive
grains are less likely to come off the abrasive material during
operation, so that an abrasive material with good flexibility
capable of maintaining an excellent abrasive performance is
obtained.
[0042] Production of Abrasive Material
[0043] The abrasive material according to the present invention is
produced by applying abrasive grains and a binder onto the surface
of a moralized mesh substrate. It is preferred that the abrasive
grains are applied in a single layer so that grains align
substantially in one layer on the surface of the substrate. This is
because the retaining force of the abrasive material and the
efficiency in use of the abrasive grains are improved.
[0044] It is preferred that the abrasive grains are applied on the
substrate by a spray coating method. Among spray coating methods,
an electrostatic spray coating method is particularly preferred.
According to the electrostatic spray coating method, coating
efficiency of abrasive grains increases about 5 times relative to
an electroless spray coating method.
[0045] FIG. 1 is a schematic cross-sectional view that shows the
principle of the electrostatic spray coating method. Object 46 to
be coated is placed in front of spray nozzle 44 so as to face it
with a predetermined gap. Abrasive grains 41 and a binder (not
shown) are charged by a DC high-voltage power-supply 42, and
discharged through a spray nozzle 44 by an air flow moving in the
direction shown by arrow 43.
[0046] The abrasive particles 41 and the binder are allowed to
adhere to the object 46 to be coated (e.g., a film substrate of an
abrasive material) by coulomb force derived from corona discharging
current flowing from gun top needle electrode 45 having a high
voltage to the object to be coated 46. In this method, an
electrostatic field 47 is formed between the gun top needle
electrode 45 and the object to be coated 46 so that the abrasive
grains 41, ionized at the top of the electrostatic spray, are
allowed to fly along the electrostatic field 47 and to adhere to
the surface of the object to be coated 46 in a uniform manner.
[0047] As a result of this, the abrasive grains and the binder are
uniformly and closely applied on the metallized fiber, so that
lumps of the abrasive grains are unlikely to be formed. Moreover,
orientation of the abrasive grains on the surface of the fiber
becomes random, so that the abrasive power of the abrasive material
is improved. Furthermore, since new abrasive grains no longer
adhere to the abrasive grains having adhered because of the
electrostatic repulsion, the surface of the fiber is coated with a
substantially single layer of abrasive grains, so that the abrasive
grain retaining force of the abrasive material and the efficiency
in use of the abrasive grains are improved.
[0048] FIGS. 2 and 3 are enlarged digital images showing abrasive
grains 10 applied to the surface of the fiber 12 making up the
substrate 14 using an electrostatic spray coating method. The
magnification is 35 times for FIG. 2 and 100 times for FIG. 3. The
abrasive grains are applied on the surface of the fiber uniformly
and in closely packed.
[0049] The binder and the abrasive grains may be applied in a
separate manner, in such a manner that a mixture of binder and
abrasive grains (abrasive coating liquid) may be preliminarily
prepared, and this is directly applied to the metallized substrate
by the electrostatic spray coating method. Alternatively, first a
binder may be applied on the surface of the metallized substrate
(pre-binder) followed by applying thereon the mixture of binder and
abrasive grains by the electrostatic spray coating method.
[0050] After applying the abrasive grains and the binder on the
metallized substrate, the binder is cured to obtain the abrasive
material. Curing of the binder is generally carried out at
100.degree. C. to 160.degree. C. for 1 to 15 minutes for a phenol
resin. After that, the abrasive material is shaped into a desired
size and folded (i.e., into two or four layers) thereby forming a
ready-to-use abrasive scrub brush. Also the abrasive material may
be formed into a bag structure in which a sponge core is enclosed
by the abrasive bag to render an abrasive scrub brush.
[0051] The abrasive material of the present invention has a long
service life and fine abrasive tooth, and is superior in abrasive
efficiency.
EXAMPLES
[0052] The following examples will explain the present invention
more specifically; however, the present invention is not
particularly limited thereby.
Example 1
[0053] Rame strings of aluminum-deposited polyester having a
thickness of 12 .mu.m and a width of 0.38 mm were prepared. The
rame strings were loaded in a Raschel loom and a metallized
substrate was prepared by conducting Mackyzett knitting. The
density of knitting was set at 18 plus or minus 2 in wale (18 wefts
per inch) and 40 plus or minus 2 in course (38 warps per inch).
[0054] Next, an abrasive coating liquid was prepared by blending:
100 g of silicon carbide (SiC) having an average grain size of 30
.mu.m (available from Nanko Ceramics (K.K.)), 20 g of epoxy resin
available under the trade designation "EPOTOHTO YD 128R" (available
from Tohto Kasei (K.K.)), 20 g of resin available under the trade
designation "VERSAMIDE 125" (available from Henkel-Hakusui (K.K.))
and 75 g of propylene glycol monomethyl ether (available from Dow
Corning Inc.). The coating liquid was applied to a surface of the
metallized substrate.
[0055] FIG. 4 is a schematic drawing of a coating device used in
the electrostatic spray coating method. The abrasive coating liquid
was sent under pressure from holding tank 61 (equipped with an air
mixer) to diaphragm pump 62 and was circulated through a pressure
difference between paint regulator 63 and back pressure regulator
64. The pressure difference was set at not less than 0.15 Mps as
measured on gauges 65 and 66.
[0056] The coating liquid flowing from the holding tank 81 was sent
to an electrostatic spray gun where an atomized stream of coating
liquid and air was formed. The output of the spray gun 67 was
controlled by an accuracy paint regulator 68 placed at the inlet of
the gun. A voltage was applied to the electrode of the gun by a
low-voltage control device 69 so as to form an electrostatic field.
The air was ionized at the top of the electrode so that the
particles of coating liquid passing through the ionized area were
negatively charged. The coating liquid was applied to metallized
substrate 70 in the direction of the electrostatic field.
[0057] With respect to the coating device, an electrostatic spray
gun commercially available as "REA-90 FOR 75785 SOLVENT-BASED
PAINT" and a low-voltage control unit commercially available as
"9040 CASCADE LOW-VOLTAGE CONTROL UNIT" (from Lanzburg Industry
Ltd.) were used. The coating conditions were set as follows:
1 TABLE 1 Abrasive coating liquid viscosity 12.5 cps Application
amount of abrasive 26 g/m.sup.2(0.017 g/inch.sup.2) coating liquid
(dry state) Plant air pressure 0.6 Mpa Circulated pressure
difference 0.15 Mpa Regulator pressure 0.02 Mpa Voltage 70 kV
Distance between electrodes 550 mm
[0058] Thereafter, the coated substrate was cured at 140.degree. C.
for three minutes to obtain an abrasive material. The resulting
abrasive material was formed into a bag having a length of 20 cm
and a width of 12 cm. An expanded urethane sponge having a size of
14 cm.times.7.5 cm.times.2.0 cm (commercially available from
Achilles Corporation under the trade designation "AERONFOAM UVK")
was enclosed in the bag to obtain an abrasive scrub brush.
[0059] An abrasive test for the above abrasive scrub brush was
carried out by manual operation. Substrates abraded included a
coated polyurethane resin (PU) plate (automobile bumper), pottery
(dish) and a stainless plate. Each substrate had a predetermined
amount of dirt adhered thereto. The types of the dirt were a
mixture of exhaust gas and mud stain for the coated polyurethane
resin, tea incrustations for the pottery, and oil stain for the
stainless plate.
[0060] The abrasive load was about 0.5 kg and the abrasive area was
about 120 cm.sup.2. The abrasive scrub was moved around on the
dirt-soiled substrate. The time elapsed until dirt was no longer
observed on the substrate was measured and the results are reported
in Table 2.
Example 2
[0061] The substrate used for Example 2 was a sheet material
comprising an aluminum film formed on the surface of a polyvinyl
alcohol net material (commercially available under the trade
designation "TOUGH-BELL from Aion Company). The substrate had a
thickness of 50 .mu.m, and the openings in the mesh measured on
average 0.5 mm (vertical) by 0.5 mm (horizontal). The mesh had an
opening ratio or 20%.
[0062] The binder and abrasive grains were applied and cured as
described in Example 1. Testing of the resulting abrasive scrub
brush was carried out as in Example 1. The results are reported in
Table 2.
Comparative Example 1
[0063] An abrasive scrub brush of nonwoven cloth (commercially
available under the trade designation "SCOTCH-BRITE S-VFB #600"
(from 3M Company, St. Paul Minn.) containing silicone carbide
abrasive grains having an average grain diameter of 30 .mu.m
(manufactured by Minnesota Mining and Manufacturing Company) was
used as the abrasive scrub brush. An abrasive test for this
abrasive scrub brush was carried out in the same manner as Example
1. The results are reported in Table 2.
2 TABLE 2 Comparative Substrate Example 1 Example 2 Example Coated
PU resin 17 sec 18 sec 22 sec plate Pottery 11 sec 13 sec 21 sec
Stainless plate 13 sec 13 sec 16 sec
Example 3
[0064] A metallized substrate was prepared as described in Example
1 by using rame strings of aluminum plated polyester. Abrasive
grains were applied thereon to prepare an abrasive material having
mesh structure. The resulted abrasive material was mounted on an
abrasive test machine (Schaefer Co. abrasive test machine) and
abrasive durability was tested.
[0065] The abrasive material was pressed onto a copper plate (phi
100, 100 g) with a predetermined load. The abrasive machine was
turned on and the abrasive material was rotated relative to the
copper plate. The test conditions are reported in Table 3.
3 TABLE 3 Abrasive machine Schaefer test abrasive machine Abrasive
method Wet grinding Lubricant Water Object to be abraded Copper
plate phi 100 mm Abrasive load 4.5 kg Rotation number 500 rotation
(1 min 52 sec) .times. 4
[0066] Thereafter, the copper plate was weighed every 500 rotation
for 4 times, and the resulting weight was deducted from the initial
weight to calculate the abrasive amount. The abrasive amount (g)
and accumulative abrasive amount (g) are reported in Table 4.
Comparative Example 2
[0067] An abrasive material having mesh structure was prepared
according to substantially the same manner as described in Example
1, except that non-metallized polyester strings having a thickness
of 12 .mu.m, and a width of 0.38 mm were used. The resulting
abrasive material was tested in abrasive durability as described in
Example 3. The results are reported in Table 4.
4 TABLE 4 Example 3 Comp. Ex. 2 Rotation no. Cumulative Cumulative
500.times. Amount (g) Amount (g) Amount (g) Amount(g) 1 0.085 0.085
0.05 0.05 2 0.065 0.15 0.03 0.08 3 0.04 0.19 0.02 0.10 4 0.03 0.22
0.02 0.12
[0068] The results show that the abrasive material having mesh
structure according to the present invention has fine abrasive
tooth and is superior in abrasive efficiency and in abrasive
durability.
* * * * *