JP2001277128A - Blasting material and blasting process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blasting material suited for the process of blasting the surface of a resin product. SOLUTION: The blasting material is obtained by blending 0.1 to 20 pts.wt. inorganic fillers with 100 pts.wt. resin bases. One or more than two kinds of resins selected from among melamine resin, urea resin, phenol resin, ketone resin, epoxy resin and guanamine resin are suitable for use as the base resins. One or more than two kinds of substances selected from among alumina, silica, carbon black, calcium carbonate, magnesium carbonate, talc, clay, glass fibers, glass balloons, metals, iron oxides, and iron-oxide-containing compounds are suitable for use as the inorganic fillers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blasting material for blasting the surface of a member, and more particularly to a blasting material for blasting the surface of a resin product. The present invention also relates to a blast processing method using the blast material.

[0002]

2. Description of the Related Art When a resin product such as a urethane bumper of an automobile is reused, the surface coating may be peeled off, and blasting may be performed for this peeling treatment.

[0003] As a blasting material for such blasting, glass beads, cone powder, walnut powder and the like are used.

Japanese Unexamined Patent Publication No. Hei 5-117635 describes a projection material in which a hard substance such as silica sand, garnet, fused alumina, or silicon carbide is bonded with a binder such as a phenol resin, an epoxy resin, a polyamide resin, or rubber. Have been. According to the same publication, the compounding amount of this hard substance is 20
４０40% by volume, and blast treatment of SS41 steel material is performed.

[0005]

In the blast treatment of a resin product using glass beads, the surface of the resin product is severely worn; the crushing rate of the glass beads is high and the glass beads are not easily reused. There's a problem.

[0006] Blasting using corn powder or walnut powder requires a long processing time; poor adhesion of paints and other adhering substances; poor work environment and dust measures.

The blast material disclosed in Japanese Patent Application Laid-Open No. 5-117635 is for blasting a steel material, and the surface of the material to be processed has an excessively strong grinding force and the surface of a resin product is excessively worn.

The present invention solves the above problems, and a blasting material capable of efficiently removing and removing deposits such as paint without damaging the surface of a resin product, and a blast treatment using the same. The aim is to provide a method.

[0009]

According to a first aspect of the present invention, there is provided a blasting material comprising an inorganic filler in an amount of 0.1 to 100 parts by weight of a base resin.
It is characterized by being blended in an amount of 1 to 20 parts by weight.

As the base resin, one or more of melamine resin, urea resin, phenol resin, ketone resin, epoxy resin and guanamine resin are suitable.

The inorganic filler may be one of alumina, silica, carbon black, calcium carbonate, magnesium carbonate, talc, clay, glass fiber, glass balloon, metal, iron oxide-containing compounds such as iron oxide and ferrite, or Two or more are preferred.

When the surface of a resin product is subjected to blasting treatment by using the blasting material of the present invention, it is possible to efficiently remove deposits such as paint without damaging or almost damaging the surface of the resin product.

The above-mentioned melamine resin, urea resin, phenol resin, ketone resin, epoxy resin and guanamine resin are all excellent in heat resistance and impact resistance, and do not deteriorate even when heated when projected. Since it is hard to be powdered by the impact of, it can be used repeatedly. In addition, since the powder is hardly powdered, the environment for the blasting process is also good.

The shot material of the present invention may further contain 50 parts by weight or less of an organic filler based on 100 parts by weight of the base resin. As the organic filler, one or more of cellulose, a cellulose derivative, α-cellulose, and wood flour are suitable.

In the blasting method of the present invention, blasting of the surface of an object to be projected such as a resin product is performed by using such a blasting material.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The blasting material of the present invention is a blasting material for blasting the surface of a resin product. The base resin is preferably one or more of a melamine resin, a urea resin, a phenol resin, a ketone resin, an epoxy resin and a guanamine resin.

Incidentally, the shot material made of a melamine resin is particularly excellent in heat resistance and impact resistance. Projectiles made of urea resin are particularly excellent in impact resistance. Projectiles made of phenolic resin are particularly excellent in heat resistance. Projectiles made of ketone resins are particularly excellent in wear resistance. The projectile made of epoxy resin is particularly excellent in heat resistance and water resistance. Projectiles made of guanamine resin are particularly excellent in impact resistance.

When two or more resins are used, a blend of two or more resins may be used, or a copolymer of two or more resins may be used. It may be obtained by copolymerizing a monomer.

As the inorganic filler, alumina, silica, carbon black, calcium carbonate, magnesium carbonate,
Talc, clay, glass fiber, glass balloon, metal,
One or more of fibrous materials such as iron oxide and compounds containing iron oxide (such as ferrite), granular materials, and crushed materials are suitable.

By selecting and adjusting the type and amount of the inorganic filler, the specific gravity, hardness and the like of the projectile can be selected and adjusted according to the properties of the object to be projected, the purpose of the blast treatment, and the like. The specific gravity is preferably 1.3 to 1.7, and the Rockwell hardness is preferably 100 to 130.

Of these, alumina, silica and glass fibers have high hardness and are suitable for relatively strong blasting. Since calcium carbonate, magnesium carbonate, talc, and clay have low hardness, they are suitable for relatively soft blasting. Glass balloons are suitable for blending when reducing the specific gravity of the shot material. When carbon black is blended, it is possible to impart conductivity to the shot material. The particle size of these inorganic fillers is 5 to 5
It is preferably about 00 μm, particularly about 10 to 200 μm.

As the inorganic filler, alumina, silica, carbon black, calcium carbonate, magnesium carbonate,
Talc, clay, glass fiber, glass balloon, metal,
When a fibrous material, a granular material, a crushed material, or the like of iron oxide or a compound containing iron oxide (such as ferrite) is blended, the shot material can be adjusted to a suitable specific gravity. In addition, by blending spherical, crushed, or fibrous iron oxide or a compound containing iron oxide (such as ferrite), it is possible to prevent the generation of static electricity during the crushing step at the time of sizing the shot material and at the time of projection. In any case, polishing by blasting, coating film peeling, mold washability, and the like can be improved.

Further, pigments containing iron oxide or a compound containing iron oxide (ferrite, etc.), specifically, αFeOOH, β
FeOOH, γFeOOH, αFe ₂ O ₃ , γFe ₂ O
_By mixing ₃ , Fe ₃ O ₄ , MoFe ₂ O ₃ , Mo ₆ Fe ₂ O _3, etc., it is possible to impart a color to the blasting material and color-code it, which is advantageous in handling and managing products. It is.

The filler made of a metal or a pigment containing iron oxide or a compound containing iron oxide (such as ferrite) has a particle size of 10 μm or less, particularly 5 μm or less, particularly 1 μm or less.
For example, those having a thickness of 0.005 to 1 μm are preferable.

The amount of such an inorganic filler is 0.1 to 20 parts by weight, preferably 1 to 15 parts by weight, particularly preferably 3 to 10 parts by weight, based on 100 parts by weight of the base resin. If the amount of the inorganic filler is less than 0.1 part by weight, the surface of the projection cannot be sufficiently peeled off, and if the amount is more than 20 parts by weight, the peeling becomes too strong.

In particular, when a filler made of a metal or a pigment containing iron oxide or a compound containing iron oxide (such as ferrite) is blended as the inorganic filler, the amount of the filler varies depending on the purpose of blending. However, it is preferably 10 parts by weight or less, particularly preferably 0.001 to 1 part by weight, based on 100 parts by weight of the base resin.

In the shot material of the present invention, an organic filler may be further blended in an amount of 50 parts by weight or less based on 100 parts by weight of the base resin. As the organic filler, one or more of cellulose, a cellulose derivative, α-cellulose, and wood flour are suitable.

By incorporating this organic filler, the toughness of the shot material can be increased. If the amount of the organic filler is more than 50 parts by weight, the particle strength of the blast material is too low. When the organic filler is blended, the above effect can be sufficiently obtained by blending 5 parts by weight or more, but it is particularly preferable to blend 10 to 40 parts by weight, especially 20 to 30 parts by weight.

The particles constituting the blasting material of the present invention may have a uniform composition, or may consist of an aggregate of particles having different compositions.

The blasting material of the present invention is obtained by crushing or pulverizing a lump or pellet of a base resin containing the above-mentioned inorganic filler and, if necessary, an organic filler with a crusher or a crusher, and adjusting it to a predetermined particle size. You only need to granulate. A coupling agent may be added to the base resin as needed. In addition, you may add the above-mentioned inorganic filler or organic filler at the time of this crushing or pulverization.

The particle size of the blast material has a lower limit of 200 μm or more, preferably 500 μm or more, and an upper limit of 5000 μm or less, preferably 3000 μm or less, more preferably 1000 μm or less.
m or less, particularly preferably 850 μm or less.

The blasting material of the present invention is suitable for blast treatment for removing paint from resin products, especially resin products such as urethane. Examples of the coating include urethane coating and acrylic coating, but other coatings may be used. Specific examples of the resin product include an automobile bumper and a pleasure boat.

Since the blasting material of the present invention can be easily sized to an arbitrary particle size, the blasting material of the present invention falls within the above-mentioned particle size range according to its use, that is, the type and properties of the projecting object. It is preferable to adjust the particle size as appropriate, for example, for a target having a hard material or a thick coating,
A blasting material having a relatively large particle size, specifically, a particle size of 500 to 1
A projection material having a diameter of 500 μm, and a relatively small particle size for a high-quality product such as a projectile having a soft material or a thin coating film, a resin product, an electronic component or a molded product, specifically, a particle size of 150 It is desirable to use different shot materials so as to use 射 850 μm.

As a method of spraying the powder together with the gas flow for the blast treatment, various blast methods can be used, but a dry blast method is most suitable. The dry blast method is as follows: (a) A gravity blast method in which powder is charged into a tank at a position higher than the nozzle, and the powder that has fallen into a discharge port provided at the bottom of the tank due to gravity is sprayed from the nozzle together with compressed gas. (B) A direct pressure blast method in which powder is sealed in a powder pressure feeding tank, compressed gas is fed into the tank, and powder discharged from a discharge port provided at the bottom of the tank is injected from a nozzle together with compressed gas. C) A siphon blast method in which the powder is charged into a tank located at a position lower than the nozzle, and the powder discharged from a discharge port provided at the bottom of the tank by the compressed gas suction is injected from the nozzle together with the compressed gas. However, any of these blasting methods can be used.

Normally, compressed air is used as the compressed gas. The amount of the powder, the pressure of the compressed gas, and the injection speed for the blast treatment can be appropriately selected depending on the type of the powder used and the state of the adhered substance on the resin product surface.

The powder used after the blast treatment can be separated and recovered from the adhered substance using a conventional post-treatment facility such as a cyclone, and can be reused.

[0037]

Example 1 80 parts by weight of melamine, 20 parts by weight of urea and 200 parts by weight of formaldehyde were mixed, adjusted to pH 9 to 10, heated and reacted under reflux to obtain a melamine / urea resin. .

After drying, a particle size of 30 to 50 μm
5 parts by weight of alumina and a curing agent were added thereto, and the mixture was cured by heating, pulverized and classified to obtain a resin projection material having a particle size of 500 to 850 μm.

When this blasting material was projected onto a plastic projecting object together with a gas flow, and the polishing force and the surface condition of the projecting object were measured, the polishing force was extremely good, and no damage was observed on the plastic surface. Was.

Comparative Example 1 A blasting material was produced in the same manner as in Example 1 except that alumina was not added, and the same blasting was performed to measure the polishing power. Was.

[0041]

As is clear from the above Examples and Comparative Examples, according to the present invention, a shot material suitable for blasting the surface of a resin product is provided. According to this blast material, the attached matter can be efficiently removed and removed without damaging the surface of the resin product.

Claims (7)

[Claims] 1. A projection material comprising 0.1 to 20 parts by weight of an inorganic filler per 100 parts by weight of a base resin. 2. The projection material according to claim 1, wherein said base resin is made of one or more of melamine resin, urea resin, phenol resin, ketone resin, epoxy resin and guanamine resin. 3. The method according to claim 1, wherein the inorganic filler is alumina, silica, carbon black, calcium carbonate, magnesium carbonate, talc, clay, glass fiber,
A shot material characterized by being one or more of a glass balloon, a metal, iron oxide and an iron oxide-containing compound. 4. The method according to claim 1, further comprising adding an organic filler to the base resin in an amount of 5 parts by weight.
A shot material characterized by being blended in an amount of 0 part by weight or less. 5. The projectile according to claim 4, wherein the organic filler is one or more of cellulose, a cellulose derivative, α-cellulose, and wood flour. 6. The shot material according to claim 1, wherein the shot material has a specific gravity of 1.3 to 1.7 and a Rockwell hardness of 100 to 130. 7. A blasting method comprising blasting the surface of a projection object using the blasting material according to claim 1. Description: