U.S. patent application number 11/697337 was filed with the patent office on 2007-07-26 for shot material and method of blasting.
This patent application is currently assigned to SONY CORPORATION. Invention is credited to Daisuke Hasegawa, Yasuhito Inagaki, Tetsuya Komine, Masahiro Sawaguchi.
Application Number | 20070173181 11/697337 |
Document ID | / |
Family ID | 27738904 |
Filed Date | 2007-07-26 |
United States Patent
Application |
20070173181 |
Kind Code |
A1 |
Inagaki; Yasuhito ; et
al. |
July 26, 2007 |
SHOT MATERIAL AND METHOD OF BLASTING
Abstract
It is an object of the present invention to provide a blasting
method and a shot material, which are very practical both in the
cost and the treatment performance. (a) A shot material containing
a styrene ion-exchange resin or a waste material caused therefrom,
or/and a dried sludge-derived material, (b) a shot material
containing a resin which is comprised of a resin containing a
rubber component and a resin containing no rubber component, and
(c) a shot material containing at least one component selected from
the group consisting of an epoxy resin composition and inorganic
filler, and a blasting method using the shot material.
Inventors: |
Inagaki; Yasuhito;
(Kanagawa, JP) ; Komine; Tetsuya; (Kanagawa,
JP) ; Sawaguchi; Masahiro; (Miyagi, JP) ;
Hasegawa; Daisuke; (Miyagi, JP) |
Correspondence
Address: |
SONNENSCHEIN NATH & ROSENTHAL LLP
P.O. BOX 061080
WACKER DRIVE STATION, SEARS TOWER
CHICAGO
IL
60606-1080
US
|
Assignee: |
SONY CORPORATION
Tokyo
JP
|
Family ID: |
27738904 |
Appl. No.: |
11/697337 |
Filed: |
April 6, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10504304 |
Aug 11, 2004 |
7220165 |
|
|
PCT/JP03/01433 |
Feb 12, 2003 |
|
|
|
11697337 |
Apr 6, 2007 |
|
|
|
Current U.S.
Class: |
451/38 ;
525/70 |
Current CPC
Class: |
B24C 11/005 20130101;
B24C 11/00 20130101 |
Class at
Publication: |
451/038 ;
525/070 |
International
Class: |
B24C 1/00 20060101
B24C001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 12, 2002 |
JP |
2002-034607 |
Feb 12, 2002 |
JP |
2002-034611 |
Mar 29, 2002 |
JP |
2002-096980 |
Claims
1. A blasting treatment method comprising at least the step of
blasting shot material comprising a resin (C) comprised of a resin
(A) containing a rubber component and a resin (B) containing no
rubber component.
2. The blasting treatment method according to claim 1, wherein at
least one of said resin (A) containing a rubber component and said
resin (B) containing no rubber component is a used resin.
3. A blasting method of claim 1, wherein said resin (C) is a used
resin salvaged from a used magnetic recording product.
4. The blasting method according to claim 1, wherein the weight
ratio of said resin (B) containing no rubber component to said
resin (A) containing a rubber component {(B)/(A)} is in the range
of 0.001 to 5.
5. The blasting method according to claim 1, wherein the content of
said resin (C) in said shot material is 0.1 to 100% by weight.
6. The blasting method according to claim 1, wherein said resin (A)
containing a rubber component is a HIPS (high impact polystyrene)
and/or ABS (acrylonitrile/butadiene/styrene resin), and said resin
(B) containing no rubber component is a PS (polystyrene) and/or AS
(acrylonitrile/styrene resin).
7. A shot material comprising a resin (C) comprised of a resin (A)
containing a rubber component and a resin (B) containing no rubber
component.
8. The shot material according to claim 7, wherein at least one of
said resin (A) containing a rubber component and said resin (B)
containing no rubber component is a used resin.
9. The shot material according to claim 7, wherein said resin (C)
is a used resin salvaged from a used magnetic recording
product.
10. The shot material according to claim 7, wherein the weight
ratio of said resin (B) containing no rubber component to said
resin (A) containing a rubber component {(B)/(A)} is in the range
of 0.001 to 5.
11. The shot material according to claim 7, wherein the content of
said resin (C) in said shot material is 0.1 to 100% by weight.
12. The shot material according to claim 7, wherein said resin (A)
containing a rubber component is a HIPS (high impact polystyrene)
and/or ABS (acrylonitrile/butadiene/styrene resin), and said resin
(B) containing no rubber component is a PS (polystyrene) and/or AS
(acrylonitrile/styrene resin).
13. An industrial product having a surface resulting from blasting
with shot material comprising a resin (C) comprised of a resin (A)
containing a rubber component and a resin (B) containing no rubber
component.
14. A method of processing a waste material at least comprising the
step of blasting the waste material with shot material comprising a
resin (C) comprised of a resin (A) containing a rubber component
and a resin (B) containing no rubber component.
15. A product obtained by a blasting a waste product with shot
material comprising a resin (C) comprised of a resin (A) containing
a rubber component and a resin (B) containing no rubber component.
Description
RELATED APPLICATION DATA
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/504,304, filed Aug. 11, 2004, the entirety of which is
incorporated herein by reference to the extent permitted by law,
which is the Section 371 National Stage of PCT/JP03/01433. This
application claims the benefit of priority to PCT International
Application No. PCT/JP03/01433, filed Feb. 12, 2003 and Japanese
Patent Application Nos. P2002-034607, filed Feb. 12, 2002,
P2002-034611, filed Feb. 12, 2002, and P2002-096980, filed Mar. 29,
2002.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a shot material and a
blasting method using the shot material.
[0003] Blast processing is used in a wide variety of fields for
peeling a coating, such as a white line on the pavement, and
removing other deposits, removing a deposit to a rubber mold,
removing a deposit, such as paint, pollutant, rust, or surface
oxide, deburring of a resin shaped article, or surface abrasion.
Conventionally, as a shot material for use in the blast processing,
particles made of various materials, such as alumina, glass, or a
resin, have been utilized. Recently, from the viewpoint of
reduction and recycle of waste for preventing environmental
pollution, attempts are vigorously made to remove coating films in
products disposed of (for example, metal materials and resin
materials in automobiles and household appliances) by blasting
treatment using the shot material to reuse them as raw materials.
Therefore, various studies have been made on the shot material used
in the blasting treatment (e.g., Japanese Patent Application
Publication No. 2001-277123).
[0004] However, the blasting treatment for peeling the coating
films in waste requires a great amount of the shot material, and
therefore poses problems of costs for the material of the shot
itself and for treating the used shot material. In addition, the
shot material used for an object of reusing waste becomes another
waste and hence the used shot material must be treated, antistatic
properties must be imparted to the shot material for preventing it
from adhering to the materials peeled, and safety must be secured
for preventing an occurrence of dust explosion, and these problems
of treatments for the shot material are the big hurdle that should
be overcome for putting the shot material into practical use.
[0005] In view of the above problems accompanying the current
techniques, an object of the present invention is to provide a
blasting method and a shot material, which are very practical both
in the cost and the treatment performance.
SUMMARY OF THE INVENTION
[0006] The present inventors have conducted extensive and intensive
studies with a view toward solving the above-mentioned problems. As
a result, it has been found that the use of, individually or in
combination, (a) a shot material containing a styrene ion-exchange
resin or a waste material caused therefrom, or/and a dried
sludge-derived material, (b) a shot material containing a resin (C)
which is comprised of a resin (A) containing a rubber component
{heresinafter, frequently referred to simply as "resin (A)"} and a
resin (B) containing no rubber component {heresinafter, frequently
referred to simply as "resin (B)"}, and (c) a shot material
containing an epoxy resin composition and inorganic filler is
extremely effective in solution or improvement of the above
problems, and the present invention has been completed.
[0007] Specifically, the present invention is directed to:
[0008] (1) a shot material characterized in that it contains a
styrene ion-exchange resin or/and a dried sludge-derived
material;
[0009] (2) the shot material according to item (1) above,
characterized in that the styrene ion-exchange resin or/and the
dried sludge-derived material are contained in an amount of 0.1% by
weight or more;
[0010] (3) the shot material according to item (1) above,
characterized in that the styrene ion-exchange resin is a waste
material which has been used for a purpose;
[0011] (4) the shot material according to item (1) above,
characterized in that the dried sludge-derived material contains
30% by weight or more of an inorganic component;
[0012] (5) the shot material according to item (1) above,
characterized in that it further contains another shot material
other than the styrene ion-exchange resin and the dried
sludge-derived material; and
[0013] (6) the shot material according to item (5) above,
characterized in that the another shot material is at least one
member selected from the group consisting of a thermosetting resin,
a thermoplastic resin, a biodegradable polymer, a metal, a metal
oxide, a metal hydroxide, a metal salt, ceramic, and carbon
black.
[0014] Further, the present invention relates to:
[0015] (7) a blasting method characterized by using a shot material
which contains a styrene ion-exchange resin or/and a dried
sludge-derived material;
[0016] (8) the blasting method according to item (7) above,
characterized in that the styrene ion-exchange resin or/and the
dried sludge-derived material are contained in an amount of 0.1% by
weight or mores in the shot material;
[0017] (9) the blasting method according to item (7) above,
characterized in that the styrene ion-exchange resin is a waste
material which has been used for a purpose;
[0018] (10) the blasting method according to item (7) above,
characterized in that the dried sludge-derived material contains
30% by weight or more of an inorganic component;
[0019] (11) the blasting method according to item (7) above,
characterized in that the shot material further contains another
shot material other than the styrene ion-exchange resin and the
dried sludge-derived material; and
[0020] (12) the blasting method according to item (11) above,
characterized in that the another shot material is at least one
member selected from the group consisting of a thermosetting resin,
a thermoplastic resin, a biodegradable polymer, a metal, a metal
oxide, a metal hydroxide, a metal salt, ceramic, and carbon
black.
[0021] Further, the present invention relates to:
[0022] (13) an industrial product having a surface treated with a
shot material which contains a styrene ion-exchange resin or/and a
dried sludge-derived material;
[0023] (14) a method of reprocessing waste, characterized by
conducting a blasting treatment using a shot material which
contains a styrene ion-exchange resin or/and a dried sludge-derived
material; and
[0024] (15) a reproduced product obtained by a method of
reprocessing waste characterized by conducting a blasting treatment
using a shot material which contains a styrene ion-exchange resin
or/and a dried sludge-derived material.
[0025] Further, the present invention relates to:
[0026] (16) a blasting treatment method characterized by using a
shot material which contains a resin (C) comprised of a resin (A)
containing a rubber component and a resin (B) containing no rubber
component;
[0027] (17) the blasting treatment method according to item (16)
above, characterized in that at least one of the resin (A)
containing a rubber component and the resin (B) containing no
rubber component is a used resin;
[0028] (18) the blasting treatment method according to item (16)
above, characterized in that the resin (C) is a used resin salvaged
from a used magnetic recording product;
[0029] (19) the blasting method according to item (16) above,
characterized in that the weight ratio of the resin (B) containing
no rubber component to the resin (A) containing a rubber component
{(B)/(A)} is in the range of 0.001 to 5;
[0030] (20) the blasting method according to item (16) above,
characterized in that the content of the resin (C) in the shot
material is 0.1 to 100% by weight; and
[0031] (21) the blasting method according to item (16) above,
characterized in that the resin (A) containing a rubber component
is a HIPS (high impact polystyrene) and/or ABS
(acrylonitrile/butadiene/styrene resin), and the resin (B)
containing no rubber component is a PS (polystyrene) and/or AS
(acrylonitrile/styrene resin).
[0032] Further, the present invention relates to:
[0033] (22) a shot material which contains a resin (C) comprised of
a resin (A) containing a rubber component and a resin (B)
containing no rubber component;
[0034] (23) the shot material according to item (22) above,
characterized in that at least one of the resin (A) containing a
rubber component and the resin (B) containing no rubber component
is a used resin;
[0035] (24) the shot material according to item (22) above,
characterized in that the resin (C) is a used resin salvaged from a
used magnetic recording product;
[0036] (25) the shot material according to item (22) above,
characterized in that the weight ratio of the resin (B) containing
no rubber component to the resin (A) containing a rubber component
{(B)/(A)} is in the range of 0.001 to 5; and
[0037] (26) the shot material according to item (22) above,
characterized in that the content of the resin (C) in the shot
material is 0.1 to 100% by weight.
[0038] Further, the present invention relates to:
[0039] (27) the shot material according to item (22) above,
characterized in that the resin (A) containing a rubber component
is a HIPS (high impact polystyrene) and/or ABS
(acrylonitrile/butadiene/styrene resin), and the resin (B)
containing no rubber component is a PS (polystyrene) and/or AS
(acrylonitrile/styrene resin);
[0040] (28) an industrial product having a surface treated with a
shot material which contains a resin (C) comprised of a resin (A)
containing a rubber component and a resin (B) containing no rubber
component;
[0041] (29) a method for reprocessing waste, characterized by
conducting a blasting treatment using a shot material which
contains a resin (C) comprised of a resin (A) containing a rubber
component and a resin (B) containing no rubber component; and
[0042] (30) a reproduced product obtained by a method for
reprocessing waste characterized by conducting a blasting treatment
using a shot material which contains a resin (C) comprised of a
resin (A) containing a rubber component and a resin (B) containing
no rubber component.
[0043] Further, the present invention relates to:
[0044] (31) a shot material characterized in that it contains an
epoxy resin composition and inorganic filler;
[0045] (32) the shot material according to item (31) above,
characterized in that the epoxy resin composition and the inorganic
filler are contained in an amount of 10% by weight or more;
[0046] (33) the shot material according to item (31) above,
characterized in that the inorganic filler is contained in an
amount 1 to 20 times the weight of the epoxy resin;
[0047] (34) the shot material according to item (31) above,
characterized in that the epoxy resin composition is an epoxy resin
composition for use in electric or electronic part;
[0048] (35) the shot material according to item (34) above,
characterized in that the epoxy resin composition is a discarded
material produced in an encapsulation step for the electric or
electronic part;
[0049] (36) the shot material according to item (34) above,
characterized in that the electric or electronic part is a
semiconductor device; and
[0050] (37) the shot material according to item (31) above,
characterized in that the inorganic filler contains 70% by weight
or more of a silica component.
[0051] Further, the present invention relates to:
[0052] (38) a blasting method characterized by using a shot
material which contains an epoxy resin composition and inorganic
filler;
[0053] (39) the blasting method according to item (38) above,
characterized in that the shot material contains 10% by weight or
more of the epoxy resin composition and the inorganic filler;
[0054] (40) the blasting method according to item (38) above,
characterized in that the shot material contains the inorganic
filler in an amount 1 to 20 times the weight of the epoxy
resin;
[0055] (41) the blasting method according to item (38) above,
characterized in that the epoxy resin composition is an epoxy resin
composition for use in electric or electronic part;
[0056] (42) the blasting method according to item (41) above,
characterized in that the epoxy resin composition is a discarded
material produced in an encapsulation step for the electric or
electronic part;
[0057] (43) the blasting method according to item (41) above,
characterized in that the electric or electronic part is a
semiconductor device; and
[0058] (44) the blasting method according to item (38) above,
characterized in that the inorganic filler contains 70% by weight
or more of a silica component.
[0059] Further, the present invention relates to:
[0060] (45) an industrial product having a surface treated with a
shot material which contains an epoxy resin composition and
inorganic filler;
[0061] (46) a method for reprocessing waste, characterized by
conducting a blasting treatment using a shot material which
contains an epoxy resin composition and inorganic filler; and
[0062] (47) a reproduced product obtained by a method for
reprocessing waste characterized by conducting a blasting treatment
using a shot material which contains an epoxy resin composition and
inorganic filler.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0063] As a shot material according to the first embodiment of the
present invention, there can be mentioned a shot material
characterized in that it contains a styrene ion-exchange resin
or/and a dried sludge-derived material. The styrene ion-exchange
resin has a cross-linked structure, and hence is preferable in
mechanical strength and heat resistance (which are physical
properties required for peeling films), and it has an ionic group
and hence is a material having preferable antistatic effect (which
is an effect to prevent the shot material from adhering to the
materials peeled).
[0064] With respect to the type of the ionic group in the styrene
ion-exchange resin, there is no particular limitation, but,
generally, it is sulfonic acid or a salt thereof, or a quaternary
ammonium salt. With respect to the amount of the ionic group
introduced into the resin, there is no particular limitation, but,
generally, it is 1 to 99 mol %. The styrene ion-exchange resin may
be either a virgin material (which means an unused resin; this
applies to the following) or a waste material which has been used
for a purpose. The used waste material includes discarded materials
and defectives discharged from a plant. From the viewpoint of
effective utilization of resources and reduction of waste, it is
more preferred that a used waste material is used. The styrene
ion-exchange resin used in the present invention may be a mixture
of a virgin material and a used waste material.
[0065] It is especially preferred that the styrene ion-exchange
resin contained in the shot material of the present invention is in
the form of particles. With respect to the form of the styrene
ion-exchange resin particles, there is no particular limitation,
and the particles may have various forms, such as a spherical form,
a long spherical form, a needle-like form, and a scale-like form.
Of these, from the viewpoint of obtaining preferable impact
resistance of the particles, uniform abrasive effect, and the like,
it is preferred that part more than half of the particles are in a
spherical form or a long spherical form. In the present invention,
the spherical form or long spherical form means that the projected
view or plan view of the particle has a circular form, an elliptic
form, an extended circular form, a peanut form, or an egg form,
which is more preferred than particles having an angular or
indefinite form. In the present invention, the styrene ion-exchange
resin is generally used in a state such that it is swelled with
water, but the resin may be either used as it is as a shot material
or used in a state of being frozen or dried as a shot material.
Especially when used in a state of being dried or frozen, more
preferable blasting effect is expected.
[0066] In the present invention, with respect to the method for
forming particles of the styrene ion-exchange resin, there is no
particular limitation, and examples include a method in which
particles are formed from mass or pellets of the styrene
ion-exchange resin using a known crusher or a known grinder, such
as a ball mill or a grinding mill. The particle size of the
ion-exchange resin used in the blasting treatment is generally
about 0.0001 to 10 mm, especially, more preferably about 0.005 to 5
mm. Examples of methods for adjusting the particle size include a
method in which the ion-exchange resin is classified before or
after drying or freezing, and a method in which the ion-exchange
resin is ground by means of a grinder or the like and then
classified. A standard for the classification cannot be generally
specified since it varies depending on the use, but it is preferred
that about 70% by weight or more of the total weight falls in the
range of about .+-.20% of the average particle size. The
classification may be either a dry process or a wet process.
[0067] With respect to the sludge for the dried sludge-derived
material contained in the shot material of present invention, there
is no particular limitation, but sludge containing an inorganic
component in a large amount is desired. Examples of inorganic
components include metal salts, metal oxides, and metal hydroxides
of Ca, Al, Si, Fe, Mg, Ti, Na, K, or Cu. Examples of metal salts
include carbonates, halide salts including hydrochlorides,
sulfates, phosphates, nitrates, acetates, and borates. It is
desired that the content of the inorganic component in the dried
sludge is 30% by weight or more.
[0068] The above sludge can be obtained from construction
wastewater treatment, plant wastewater treatment, water treatment,
or sewage treatment, but, generally, the sludge obtained from
sewage treatment contains a large amount of an organic component
and therefore, it is more desired that sludge other than this is
used. Particularly, sludge discharged from a fabrication plant or
assembling plant of semiconductor, (liquid crystal) substrate, or
cathode ray tube has a single formulation and contains a large
amount of an inorganic component and hence is more preferred as the
shot material. Generally, the sludge is dried by heating in
incineration or by means of a kiln, and then buried or mixed into
cement, but, in the present invention, the dried material obtained
from the sludge is used as a shot material for use in blasting
treatment. The dried sludge-derived material used in the present
invention can be obtained by a known treatment. For example, the
sludge is made to coagulate and settle naturally or by means of a
chemical, such as a coagulant, or a mechanical means, such as
pressing or centrifuging. The sludge which coagulates and settles
can be obtained by filtration and drying if desired. As a method
for drying the sludge containing moisturesin addition to the
above-mentioned incineration or kiln treatment, any drying method
including sun-drying, freeze-drying, hot-air drying, and vacuum
drying may be used.
[0069] The dried sludge-derived material may be either used as it
is as a shot material or adjusted to have a predetermined particle
size. With respect to the particle size, there is no particular
limitation, but the particle size is generally about 0.0001 to 10
mm, more preferably about 0.005 to 5 mm. As a method for adjusting
the particle size of the dried sludge, the particle size may be
adjusted before drying, or the dried sludge may be ground by means
of a grinder, such as a ball mill or a grinding mill, and then
classified. A standard for the classification cannot be generally
specified since it varies depending on the use, but it is preferred
that about 70% by weight or more of the total weight falls in the
range of about .+-.20% of the average particle size. The
classification may be either a dry process or a wet process.
[0070] In the shot material according to the above embodiment of
the present invention, for obtaining satisfactory peel effect for
coat film in the blasting treatment, the styrene ion-exchange resin
or/and the dried sludge-derived material are contained in an amount
of about 0.1% by weight or more, preferably about 1% by weight or
more. When the shot material and another shot material described
below in detail are used in combination, it is preferred that the
amount of the styrene ion-exchange resin or/and the dried
sludge-derived material falls in the above range.
[0071] The shot material according to the above embodiment of the
present invention may contain individually the styrene ion-exchange
resin and the dried sludge-derived material or both the styrene
ion-exchange resin and the dried sludge-derived material in
combination.
[0072] As a shot material according to the second embodiment of the
present invention, there can be mentioned a shot material
characterized in that it contains a resin (C) comprised of a resin
(A) containing a rubber component {heresinafter, frequently
referred to simply as "resin (A)"} and a resin (B) containing no
rubber component {heresinafter, frequently referred to simply as
"resin (B)"}.
[0073] With respect to the resin (A) containing a rubber component
in the present invention, there is no particular limitation, and
examples include ABS (acrylonitrile/butadiene/styrene) resins, HIPS
(high impact polystyrene) resins, and alloys of the above resin and
another resin. With respect to the alloy, there is no particular
limitation as long as it is a resin compatible with ABS and/or
HIPS, but, generally, alloys, such as ABS/PC (polycarbonate),
ABS/PET (polyethylene terephthalate), ABS/PVC (polyvinyl chloride),
ABS/PPE (polyphenylene ether), ABS/PSF (polysulfone), ABS/PBT
(polybutylene terephthalate), ABS/nylon, and HIPS/PPE
(polyphenylene ether), HIPS/PMMA (polymethyl methacrylate), and
HIPS/polyolefin, are typical. In the used resin waste material in
the present invention, these resins may be contained individually
or a mixture of the two or more resins may be contained. When the
resin (A) containing a rubber component is contained in the shot
material, the toughness of the shot material particles is improved
in the blasting treatment, so that the amount of dust generated
during the blasting treatment is reduced.
[0074] With respect to the resin (B) containing no rubber component
in the present invention, there is no particular limitation, and
examples include AS, PS, PC, PET, PVC, PPE, PSF, PBT, nylon, PMMA,
and polyolefin. Of these, preferred are AS and PS. When the resin
(B) containing no rubber component is contained in the shot
material, the hardness of the shot material becomes appropriate, so
that a deposit, such as a coating, can be efficiently removed
without causing no or almost no damage on the surface of a material
to be blasted (e.g., a resin product).
[0075] Each of the above-mentioned resin (A) containing a rubber
component and resin (B) containing no rubber component can be
easily produced, and ones commercially available for various
grades, such as general-purpose, high-stiffness, high-impact,
wear-resistance, high-sliding, heat-resistance, transparence,
high-luster, chemical-resistance, and coating grades, may be used.
Alternatively, the resins may be ones which are not commercially
available but produced in a resin plant. The resins (A) and (B) may
contain various additives for resin, such as an antistatic agent, a
coloring agent, a pigment, an antioxidant, a flame retardant, a
plasticizer, a light resistance accelerator, a compatibilizer, a
surface treating agent, a modifier, a coloring agent (e.g., carbon
black), glass fiber, paper, and nonwoven fabric.
[0076] As the resin (C) comprised of the resin (A) containing a
rubber component and the resin (B) containing no rubber component,
either the resins may be mixed together or a mixture of the resins
may be used. Specifically, in the resin (C), either the resin (A)
and the resin (B) may be individually in an independent form
(particles, pellets, or mass), or the resin (A) and the resin (B)
may be mixed with each other in a molten state. When using a virgin
material (which means an unused resin; this applies to the
following), these resins are mixed and can be used as a shot
material. When using a used waste material, either resins
separately salvaged may be mixed together or a mixture of the
resins may be used. As the used resin salvaged from used waste
materials, all kinds of resin waste materials which have been used
in electrical appliances, office appliances, vehicles, and
miscellaneous goods can be used. As the used resin, ones discharged
in a fabrication plant as discarded materials of runner materials
and raw material pellets may be used. The used resins generated in
a plant and those salvaged from the standardized products (which
are the same product or belong to the same product group) generally
have consistent physical properties, and therefore they are more
preferred from the viewpoint of reuse. Examples of the standardized
products include recording media related products (videocassette
shell), more specifically, videocassette for professional use and 8
mm videocassette and DV cassette for consumer use, household game
machine (controller), and portable phone. Especially, in the
present invention, it is preferred that the resin (C) is a used
resin salvaged from a used magnetic recording product. With respect
to the magnetic recording product, there is no particular
limitation, and examples include the above-mentioned videocassettes
and music tape cassettes. The magnetic recording product includes
not only a magnetic recording medium but also a housing for
protecting it, such as a casing and a shell.
[0077] In these products, generally, for improving the impact
resistance of the products, the resin (A) containing a rubber
component is used. On the other hand, the resin (B) containing no
rubber component, such as a PS or AS resin, is frequently used as a
window material or a casing material (transparent) in the products.
When the used resins are surely separated from one another, the
individual resins salvaged {the resin (A) and the resin (B)} are
mixed together and can be used as a shot material, but, when the
resin (A) and the resin (B) are contained mixed in a product, such
as a cassette casing, both the resins are contained in the resin
salvaged. In this case, it is preferred that the weight ratio of
the resin (B) to the resin (A) {(B)/(A)} is in the range of about
0.001 to 5. When the weight ratio is not in the above range, it is
preferred to make up for a lack of the resin (A) or resin (B) so
that the weight ratio of the resin (B) to the resin (A) falls
within the above range. When the individual resins (which may be
used resins) are mixed together and used, it is more preferred that
the resins are mixed in the above ratio and used as a shot
material. It is more preferred that the content of the resin (C)
comprised of the resin (A) and the resin (B) in the shot material
is about 0.1 to 100% by weight. For suppressing the amount of dust
generated during the blasting treatment and preventing the blasted
surface from suffering a damage, it is preferred that the resin (C)
content falls in the above range. The resin (C) content is similar
when another shot material described below in detail is
contained.
[0078] It is especially preferred that the resin (A), the resin
(B), or a mixed resin of the resin (A) and the resin (B) contained
in the shot material of the present invention is in the form of
particles. With respect to the form of the particles, there is no
particular limitation, and the particles may have various forms,
such as a spherical form, a long spherical form, a needle-like
form, and a scale-like form. Of these, from the viewpoint of
obtaining preferable impact resistance of the particles, uniform
abrasive effect, and the like, it is preferred that part more than
half of the particles a resin a spherical form or a long spherical
form. In the present invention, the spherical form or long
spherical form means that the perspective view or plan view of the
particle has a circular form, an elliptic form, an extended
circular form, a peanut form, or an egg form, which is more
preferred than particles having an angular or indefinite form. With
respect to the particle size of the particles, there is no
particular limitation, but the particle size is generally about
0.0001 to 10 mm, more preferably about 0.005 to 5 mm.
[0079] With respect to the method for forming the particles, there
is no particular limitation, and examples include a method in which
particles are formed from mass or pellets of the resin using a
known crusher or a known grinder, such as a ball mill or a grinding
mill. The resin (A), the resin (B), or a mixed resin of the resin
(A) and the resin (B) may be either ground by means of a grinder
and then used as a shot material, or ground and then classified
into a predetermined particle size and used. A standard for the
classification cannot be generally specified since it varies
depending on the use, but it is preferred that about 70% by weight
or more of the total weight falls in the range of about .+-.20% of
the average particle size. The classification may be either a dry
process or a wet process.
[0080] Further as a shot material according to the third embodiment
of the present invention, there can be mentioned a shot material
characterized in that it contains an epoxy resin composition and
inorganic. As the epoxy resin used as the shot material in the
present invention, preferred are compounds having two or more epoxy
groups, including epoxy resins used in applications of electric
use, coating, civil engineering, adhesive, and composite material,
and there is no particular limitation. Of these, more preferred are
those used as epoxy resins for electric use and composite material.
Among the epoxy resins for electric use and composite material,
more preferred are epoxy resins used in IC encapsulation materials
and printed boards. The epoxy resin may be any type, such as
bisphenol A type, brominated bisphenol A type, phenolic novolak
type, cresol novolak type, alicyclic type, heterocyclic type, and
flexible epoxy, but, especially, more preferred are cresol novolak
type and phenolic novolak type epoxy resins.
[0081] In the epoxy resin, generally, as a curing agent, one having
two or more functional groups for curing the epoxy resin is used.
The epoxy resin composition used in the present invention may
contain a curing agent as well as the above epoxy resin. As
examples of curing agents, there can be mentioned phenolic
compounds and amine compounds. In addition to the curing agent, an
additive, such as a surface treating agent, a curing catalyst, a
flame retardant (e.g., a halogen compound or a phosphorus
compound), a flame retardant auxiliary (e.g., an antimony compound
or a nitrogen compound), a coloring agent, an ion-capturing agent,
an elastomer, or a wax, may be contained in the epoxy resin
composition. As preferred examples of the epoxy resin compositions
used in the present invention, there can be mentioned epoxy resin
compositions for use in electric or electronic part. Especially, as
the epoxy resin composition used in the present invention, more
preferred are discarded materials produced in an encapsulation step
for the electric or electronic part.
[0082] With respect to the inorganic filler used in the shot
material according to the above embodiment of the present
invention, there is no particular limitation, and examples include
crystalline silica, fused silica, calcium carbonate, magnesium
carbonate, alumina, magnesia, talc, clay, calcium silicate,
titanium oxide, asbestos, glass fiber, calcium fluoride, calcium
sulfate, and calcium phosphate. In the present invention, a
plurality of these inorganic filler may be used in combination. Of
these, more preferred is inorganic filler comprised mainly of
silica. In the inorganic filler comprised mainly of silica, it is
more preferred that the inorganic filler contains about 70% by
weight or more of a silica component. The inorganic filler may be
contained in an amount about 1 to 20 times, preferably about 2 to 5
times the weight of the epoxy resin.
[0083] The above-described epoxy resin and inorganic filler may be
present either independently or in the form of a composite material
containing both the epoxy resin and the inorganic filler, such as
an encapsulation material for electric or electronic part, or an
epoxy substrate material. In the former, generally, the epoxy resin
and the inorganic filler are mixed together by a known method to
form the shot material of the present invention. In the latter,
either the composite material may be used as it is as a shot
material, or the epoxy resin or inorganic filler may be further
added to the composite material. In the shot material of the
present invention, a discarded material (e.g., a runner material, a
non-standardized product, mold flash or the like) discharged in a
plant may be used, or a used waste material salvaged from the
market (e.g., an IC chip, a printed board or the like) may be used.
From the viewpoint of effective utilization of resources and
reduction of waste, it is more preferred to use a used waste
material or a discarded material generated in a plant.
[0084] It is especially preferred that the epoxy resin, the
inorganic filler, or a mixture of the epoxy resin and the inorganic
filler contained in the shot material of the present invention is
in the form of particles. With respect to the form of the
particles, there is no particular limitation, and the particles may
have various forms, such as a spherical form, a long spherical
form, a needle-like form, and a scale-like form. Of these, from the
viewpoint of obtaining preferable impact resistance of the
particles, uniform abrasive effect, and the like, it is preferred
that part more than half of the particles a resin a spherical form
or a long spherical form. In the present invention, the spherical
form or long spherical form is as defined above. When the epoxy
resin, the inorganic filler, or the mixture of the epoxy resin and
the inorganic filler is in the form of particles, with respect to
the particle size of the particles, there is no particular
limitation, but the particle size is generally about 0.0001 to 10
mm, generally, more preferably about 0.005 to 5 mm. With respect to
the method for forming particles of the epoxy resin, the inorganic
filler, or the mixture of the epoxy resin and the inorganic filler,
there is no particular limitation, and examples include the
above-mentioned methods for forming particles, such as a method in
which particles are formed from mass or pellets of the resin, or a
used waste material or a discarded material generated in a plant
using a known crusher or a known grinder, such as a ball mill or a
grinding mill.
[0085] In the present invention, the above-described (a) shot
material containing a styrene ion-exchange resin or a waste
material caused therefrom, or/and a dried sludge-derived material,
(b) shot material containing a resin (C) which is comprised of a
resin (A) containing a rubber component and a resin (B) containing
no rubber component, and (c) shot material containing an epoxy
resin composition and inorganic filler may be used individually or
in combination. Further, another shot material may be mixed into
each of the shot materials (a) to (c) or the combination of these
shot materials. As the another shot material, a conventional shot
material may be used, and examples include organic polymer shot
materials and inorganic (metal, ceramic) shot materials.
[0086] Examples of organic polymer shot materials include melamine
resins, urea resins, phenolic resins, ketone resins, epoxy resins,
guanamine resins, urea resins, unsaturated polyester resins,
polycarbonate resins, acrylic resins, polyamide resins,
polyphenolic resins, polyester resins, polystyrene resins, ABS
(acrylonitrile-butadiene-styrene) resins, AS
(acrylonitrile-styrene) resins, PAN (polyacrylonitrile) resins, POM
(polyacetal) resins, PPE (polyphenylene ether), PEO (polyethylene
oxide), AES {acrylonitrile-(ethylene-propylene rubber)-styrene},
AAS (acrylonitrile-acrylate-styrene), EVA (ethylene-vinyl acetate
copolymer), butadiene resins, vinyl acetate resins, methacrylic
resins, polysulfone resins, cellulose, polyurethane resins,
biodegradable resins (such as chitin, chitosan, polylactic acid,
polyvinyl alcohol, and polyamino acid), polyacrylamide,
polycarboxylate ester, polyaminoethyl acrylate salts, and sodium
polystyrenesulfonate. The organic polymer shot material may be
either a virgin material or a waste material which has been used
for a purpose. Especially, from the viewpoint of effective
utilization of resources and reduction of waste, it is more
preferred to use a blend of the organic polymer shot material
comprised of a used waste material as a raw material and the shot
material of the present invention.
[0087] Examples of inorganic (metal, ceramic) shot materials
include steel particles, zinc particles, aluminum particles,
alumina, silica, mica, carbon black, calcium carbonate, glass
(fiber, balloon), titanium oxide, magnesium carbonate, talc, clay,
and a variety of metal oxides, metal hydroxides, and metal salts.
The inorganic shot material may be either a virgin material or a
waste material which has been used for a purpose. Especially, from
the viewpoint of effective utilization of resources and reduction
of waste, it is more preferred to use a blend of the inorganic shot
material comprised of a used waste material as a raw material and
the shot material of the present invention.
[0088] In the present invention, by selecting or controlling the
content of the shot material of the above three embodiments or the
type or content of another shot material incorporated, the specific
gravity, hardness and the like of the shot material can be
appropriately selected or controlled depending on the form of the
material to be blasted or the purpose of the blasting treatment.
For example, the use of alumina, silica, or glass fiber having a
high hardness as another shot material is preferred in a relatively
hard blasting treatment. On the other hand, the use of, for
example, calcium carbonate, magnesium carbonate, talc, or clay
having a low hardness as another shot material is preferred in a
relatively soft blasting treatment. The use of glass balloon is
preferred when lowering the specific gravity of the shot material.
When carbon black is incorporated, conductivity can be imparted to
the shot material, making it possible to more effectively prevent
the shot material from being charged. Incorporation of an organic
shot material can advantageously improve the shot material in
toughness.
[0089] The shot material of the present invention may contain a
known additive. For example, when iron oxide in a spherical form, a
shattered form, or a fibrous form or a compound containing iron
oxide (e.g., ferrite) is incorporated, the shot material can be
prevented from being electrostatically charged during the grinding
step for granulation of the shot material or during the blasting.
When a pigment containing iron oxide or a compound containing iron
oxide (e.g., ferrite), specifically, .alpha. FeOOH, .beta. FeOOH,
.gamma. FeOOH, .alpha. Fe.sub.2O.sub.3, .gamma. Fe.sub.2O.sub.3,
Fe.sub.3O.sub.4, MoFe.sub.2O.sub.3, Mo.sub.6Fe.sub.2O.sub.3, or the
like is incorporated, the shot material can be colored and
identified by color, leading to an advantage in handling or control
of the products.
[0090] With respect to the amount of the additive incorporated,
there is no particular limitation, and it cannot be generally
specified since it varies depending on the type or purpose of use
of the additive. For example, when the above-mentioned pigment
containing iron oxide or a compound containing iron oxide (e.g.,
ferrite) is incorporated as an additive, the amount of the pigment
incorporated varies depending on the purpose of incorporation, but
it is preferably about 10% by weight or less, especially preferably
about 0.001 to 1% by weight.
[0091] The present invention provides a blasting method using the
above-described novel shot material. With respect to the blasting
method, there is no particular limitation, and, for example, an
impeller having a plurality of rectangular plates radially provided
on a rotary shaft is rotated at a high speed to achieve centrifugal
shot of the shot material of the present invention, or the shot
material of the present invention is shot by an air nozzle using
compressed air. In shot of the shot material of the present
invention, a medium, such as water or air, may be either used or
not used. It is especially preferred that the shot material of the
present invention is shot using gas as a medium.
[0092] As a preferred embodiment of the blasting method of the
present invention, there can be mentioned a method in which the
shot material of the present invention is sprayed, together with a
gas stream. As the above method, various types of blasting methods
can be used, but a dry blasting method is more preferred. Examples
of dry blasting methods include: (1) a gravity blasting method in
which powder is placed in a tank at a position higher than a
nozzle, and the powder which falls by gravity toward a discharge
outlet formed in the bottom of the tank is shot through the nozzle,
together with compressed gas; (2) a direct blasting method in which
a powder pressure feed tank is packed with powder and compressed
gas is fed into the tank, and the powder discharged from a
discharge outlet formed in the bottom of the tank is shot through a
nozzle, together with the compressed gas; and (3) a siphon blasting
method in which powder is placed in a tank at a position lower than
a nozzle, and the powder discharged by suction of compressed gas
from a discharge outlet formed in the bottom of the tank is shot
through the nozzle, together with the compressed gas, and any of
these blasting methods can be used.
[0093] In the above methods, as compressed gas, generally,
compressed air is used but, for avoiding dust explosion, inert gas,
such as nitrogen, may be used. In the blasting treatment, the
powder amount, the pressure of compressed gas, and the shot speed
and time can be appropriately selected according to the type of the
powder used or the type or deposit state of the material to be
peeled (coat film).
[0094] When conducting the above-mentioned blasting treatment, the
temperature of an object to be treated may be room temperature, but
it is preferred that the object to be treated is preheated. The
heating temperature cannot be generally specified since it varies
depending on the type of the object to be treated, but it is
preferred to set the heating temperature at such a high temperature
that the quality of the object to be treated does not
deteriorate.
[0095] The shot material of the present invention which has been
used in the blasting treatment can be recovered and separated from
deposit substances using a conventional after-treatment equipment,
such as a cyclone, and reused. The shot material having deposit
substances mixed can be either reused as a shot material by
incineration treatment or blended with cement and buried. From the
viewpoint of effective utilization of resources, it is more
preferred that the used shot material is reused as a shot material
after incineration or blended with cement.
[0096] The blasting method of the present invention can be used in
a variety of applications. For example, the blasting method of the
present invention is advantageously used for removing a coating.
With respect to the coating, there is no particular limitation, and
examples include a vinyl chloride coating, an urethane coating, and
an acryl coating. With respect to the coated article, there is no
particular limitation, and examples include resin shaped articles
and wooden articles. With respect to the resin shaped article,
there is no particular limitation, and examples include a bumper,
an instrument panel or a dashboard of automobile, or a pleasure
boat. In addition, the blasting method of the present invention can
be used for peeling a coating, such as a white line on the
pavement. The blasting method of the present invention can be used
for deburring of a metal cast article or a resin shaped article or
for cleaning and polishing surface. Further, the blasting method of
the present invention can be used for removing deposits, removing a
deposit to a rubber mold, or removing pollutant, rust, or surface
oxide.
[0097] Heresinbelow, the present invention will be described in
more detail with reference to the following Examples, which should
not be construed as limiting the scope of the present
invention.
EXAMPLE 1
[0098] Using as a shot material a dried material (particle size
after grinding treatment: 500 to 850 .mu.m) formed from a
cation-exchange resin discharged from a liquid crystal plant, a
used CD film (acryl-coated Al film) was subjected to peel treatment
by means of a direct-pressure sandblasting machine for 10 seconds,
and the surface state (peel area) was measured.
EXAMPLE 2
[0099] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 1 except that a dried
material (particle size after grinding treatment: 500 to 850 .mu.m)
formed from an anion-exchange resin discharged from a semiconductor
plant was used as a shot material.
EXAMPLE 3
[0100] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 1 except that a dried
material formed from a commercially available cation-exchange resin
(Amberlite IR124Na; particle size after grinding treatment: 500 to
850 .mu.m) was used as a shot material.
EXAMPLE 4
[0101] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 1 except that a dried
material formed from a commercially available anion-exchange resin
(Amberlite IRA402BL; particle size after grinding treatment: 500 to
850 .mu.m) was used.
EXAMPLE 5
[0102] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 1 except that a
commercially available resin shot material (melamine-based;
particle size: 500 to 850 .mu.m) was blended in an amount of 60%
with the dried cation-exchange resin material in Example 1.
EXAMPLE 6
[0103] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 1 except that a
commercially available resin shot material (nylon-based; particle
size: 500 to 850 .mu.m) was blended in an amount of 20% with the
dried anion-exchange resin material in Example 4.
EXAMPLE 7
[0104] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 1 except that a used
ABS resin (cell waste from 8 mm videocassette; particle size: 500
to 850 .mu.m) was blended in an amount of 30% with the dried
cation-exchange resin material in Example 1.
COMPARATIVE EXAMPLE 1
[0105] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 1 except that the
commercially available resin shot material used in Example 5 was
solely used.
COMPARATIVE EXAMPLE 2
[0106] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 1 except that the
commercially available resin shot material used in Example 6 was
solely used.
[0107] The results of the above examples were compared and studied.
As a result, it has been found that, in Comparative Examples 1 and
2, the peel area per unit period of time for the treatment is small
and the amount of fine powder scattered is large, as compared to
those in Examples 1 to 7. Further, it has been confirmed that, by
blending the shot material of the present invention with a
commercially available shot material or used resin waste, the peel
effect is improved.
EXAMPLE 8
[0108] Using as a shot material a dried sludge-derived material
(containing Al: 30% by weight, Ca: 25% by weight, and O: 35% by
weight; particle size: 500 to 850 .mu.m) discharged from a liquid
crystal plant, a used CD film (acryl-coated Al film) was subjected
to peel treatment by means of a direct-pressure sandblasting
machine for 10 seconds, and the surface state (peel area) was
measured.
EXAMPLE 9
[0109] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 8 except that a dried
sludge-derived material (containing Ca: 50% by weight, O: 10% by
weight, and F: 20% by weight) discharged from a cathode ray tube
plant was used as a shot material.
EXAMPLE 10
[0110] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 8 except that a dried
sludge-derived material (containing Si: 30% by weight, O: 35% by
weight, Al: 15% by weight, and Ca: 10% by weight) discharged from a
semiconductor plant was used as a shot material.
EXAMPLE 11
[0111] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 8 except that a
commercially available resin shot material (melamine-based;
particle size: 500 to 850 .mu.m) was blended in an amount of 70%
with the dried sludge-derived material in Example 8.
EXAMPLE 12
[0112] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 8 except that a
commercially available resin shot material (nylon-based; particle
size: 500 to 850 .mu.m) was blended in an amount of 20% with the
dried sludge-derived material in Example 9.
EXAMPLE 13
[0113] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 8 except that a dried
material (particle size: 500 to 850 .mu.m) formed from a used
ion-exchange resin was blended in an amount of 80% with the dried
sludge-derived material in Example 10.
EXAMPLE 14
[0114] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 8 except that a used
ABS resin (cell waste from 8 mm videocassette; particle size: 500
to 850 .mu.m) was blended in an amount of 30% with the dried
sludge-derived material in Example 8.
COMPARATIVE EXAMPLE 3
[0115] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 8 except that the
commercially available resin shot material used in Example 11 was
solely used.
COMPARATIVE EXAMPLE 4
[0116] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 8 except that the
commercially available resin shot material used in Example 12 was
solely used.
[0117] The results of the above examples were compared and studied.
As a result, it has been found that, in Comparative Examples 3 and
4, the peel area per unit period of time for the treatment is small
and the amount of fine powder scattered is large, as compared to
those in Examples 8 to 14. Further, it has been confirmed that, by
blending the shot material of the present invention with a
commercially available shot material or used resin waste, the peel
effect is improved.
[0118] In the following Examples 15 to 20 and Comparative Examples
5 and 6, individually using the samples shown below as a shot
material, a used CD (acryl-coated Al film) was subjected to peel
treatment for 10 seconds, and the surface state (peel area) was
measured.
EXAMPLE 15
[0119] A resin salvaged from cassette cell for business purposes
(material salvaged from a broadcasting station):
[0120] a mixture of: a shell body (top and bottom); ABS resin (95%
by weight; high-flow high-stiffness grade) and a window of the
shell (transparent portion); AS resin (5% by weight); which was
ground and classified so that the particle size became 500 to 850
.mu.m.
EXAMPLE 16
[0121] A mixture of an ABS resin (70% by weight; 500 to 850 .mu.m)
and an AS resin (30% by weight; 500 to 850 .mu.m), which was
obtained by classifying the resin pellet waste discharged from a
resin molding plant.
EXAMPLE 17
[0122] A resin salvaged from VHS cassette cell:
[0123] a mixture of: a shell body (top and bottom); HIPS resin (97%
by weight; high-flow high-stiffness grade) and a window
(transparent) portion of the shell; PS resin (3% by weight); which
was ground by means of a grinder so that the particle size became
500 to 850 .mu.m.
EXAMPLE 18
[0124] A mixture of virgin resins:
[0125] a mixture of a ground/classified general-purpose high-impact
grade ABS resin (40% by weight; 500 to 850 .mu.m) and a
ground/classified general-purpose GPPS resin (60% by weight; 500 to
850 .mu.m).
EXAMPLE 19
[0126] The resin in Example 15 added 80% by weight of a
commercially available resin shot material (melamine-based;
particle size: 500 to 850 .mu.m).
EXAMPLE 20
[0127] The resin in Example 17 added 60% by weight of a
commercially available resin shot material (nylon-based; particle
size: 500 to 850 .mu.m).
COMPARATIVE EXAMPLE 5
[0128] The commercially available resin shot material used in
Example 19.
COMPARATIVE EXAMPLE 6
[0129] The commercially available resin shot material used in
Example 20.
[0130] The results of the above examples were compared and studied.
As a result, it has been found that, in Comparative Examples 5 and
6, the peel area per unit period of time for the treatment is small
and the amount of fine powder scattered is large, as compared to
those in Examples 15 to 20. Further, it has been confirmed that, by
blending the shot material of the present invention with a
commercially available shot material, the peel effect is further
improved.
EXAMPLE 21
[0131] A runner material for IC encapsulation material (epoxy resin
content: 10% by weight; silica content: 80% by weight) discharged
from a semiconductor assembling plant was ground and classified so
that the particle size became 500 to 850 .mu.m. Using the resultant
material as a shot material, a used CD film (acryl-coated Al film)
was subjected to peel treatment by means of a direct-pressure
sandblasting machine for 10 seconds, and the surface state (peel
area) was measured.
EXAMPLE 22
[0132] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 21 except that 60% by
weight of spherical silica was added to 40% by weight of a glass
epoxy substrate and the resultant blend was mixed, ground, and
classified so that the particle size became 500 to 850 .mu.m.
EXAMPLE 23
[0133] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 21 except that a
commercially available resin shot material (melamine-based;
particle size: 500 to 850 .mu.m) was blended in an amount of 50%
with the shot material in Example 21.
EXAMPLE 24
[0134] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 21 except that a
commercially available resin shot material (nylon-based; particle
size: 500 to 850 .mu.m) was blended in an amount of 30% with the
shot material in Example 22.
COMPARATIVE EXAMPLE 7
[0135] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 21 except that the
commercially available resin shot material used in Example 23 was
solely used.
COMPARATIVE EXAMPLE 8
[0136] A used CD film was subjected to blasting treatment in
substantially the same manner as in Example 21 except that the
commercially available resin shot material used in Example 24 was
solely used.
[0137] The results of the above examples were compared and studied.
As a result, it has been found that, in Comparative Examples 7 and
8, the peel area per unit period of time for the treatment is small
and the amount of fine powder scattered is large, as compared to
those in Examples 21 to 24. Further, it has been confirmed that, by
blending the shot material of the present invention with a
commercially available shot material or used resin waste, the peel
effect is improved.
INDUSTRIAL APPLICABILITY
[0138] According to the present invention, ion-exchange resin waste
or sludge discharged from a plant, which has conventionally not
been effectively utilized, can be reused. In addition, the used
resin (C), which is comprised of the resin (A) containing a rubber
component and the resin (B) containing no rubber component, can be
utilized. Further, a mixture of an epoxy resin composition and
inorganic filler, typically a used encapsulation material, which
has conventionally not been effectively utilized, can be reused.
Thus, by the present invention, effective utilization of resources
can be achieved and waste is reduced. Further, the use of the shot
material of the present invention improves the blasting treatment.
That is, the present invention not only improves the blasting
treatment in working efficiency but also significantly contributes
to protection of the environment.
* * * * *