JP2001277125A - 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 0.01 to 30 pts.wt. rubbers with 100 pts.wt. base resins. 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 rubbers selected from among SBR, BR, IR, EPM, EPDM, NBR, IIR, urethane rubber and silicone rubber are suitable for use as the rubbers.

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.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a small amount of fine powder scattered during blasting, and efficiently removes deposits such as paint without damaging the surface of a resin product. And a blasting method using the same.

[0009]

According to a first aspect of the present invention, there is provided a blasting material, wherein the rubber is used in an amount of 0.01 to 100 parts by weight of the base resin.
It is characterized by being mixed with 30 parts by weight.

[0010] By blending the rubber with the base resin as described above, the toughness of the shot material particles is increased, and the scattering of fine powder during blasting is reduced. In addition, it is possible to efficiently remove deposits such as paint without causing any or almost no damage to the surface of the resin product.

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

[0012] The melamine resin, urea resin, phenol resin, ketone resin, epoxy resin and guanamine resin are all excellent in heat resistance and impact resistance, do not deteriorate even when heated when projected, and are not affected by the impact of projection. Since it is hard to powder, it can be used repeatedly. In addition, since the powder is hardly powdered, the environment for the blasting process is also good.

[0013] As rubber, SBR, BR, IR, EP
One or more of M, EPDM, NBR, IIR, urethane rubber and silicone rubber are preferred.

In the blasting method of the present invention, blasting of the surface of an object to be blasted is performed using such a blasting material.

[0015]

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, wherein a rubber is compounded in an amount of 0.01 to 30 parts by weight with respect to 100 parts by weight of a base resin. 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.

In this case, one kind of each resin may be used, or two or more kinds of granular projection materials made of a single resin may be used.

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 rubber, SBR, BR, IR, EP
One or more of M, EPDM, NBR, IIR, urethane rubber and silicone rubber are suitable, and in particular, BR
One or more of (butadiene rubber), SBR, urethane rubber and silicone rubber are preferred. The compounding amount of the rubber is preferably 0.01 to 30 parts by weight, more preferably 0.05 to 20 parts by weight, especially 0.1 to 10 parts by weight, based on 100 parts by weight of the base resin. When the compounding amount of the rubber is less than 0.01 part by weight, the effect of improving the toughness of the shot material particles is insufficient, and 30
If the amount is more than the weight part, the strength of the blast material particles, particularly the strength at high temperature, may be insufficient, and the polishing force may be insufficient.

In the present invention, an inorganic filler may be further added. Examples of the inorganic filler include fibrous materials such as alumina, silica, carbon black, calcium carbonate, magnesium carbonate, talc, clay, glass fiber, glass balloon, metal, iron oxide, and compounds containing iron oxide (ferrite, etc.), and granular materials. One or two or more of such 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 blasting material can be selected and adjusted according to the properties of the object to be projected and the purpose of the blast treatment. 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 (such as ferrite), 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 comprising 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, especially 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 the 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 projectile 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 comprises rubber and, if necessary,
What is necessary is just to crush or pulverize a lump or pellet of the base resin obtained by blending the above-mentioned inorganic filler and organic filler with a crusher or a crusher, and to adjust the particle size to a predetermined particle size. When blending an inorganic filler or an organic filler, a coupling agent may be added to the base resin as necessary. In addition, you may add the above-mentioned inorganic filler or organic filler at the time of this crushing or pulverization.

The lower limit of the particle diameter of the shot material is 200 μm or more, preferably 500 μm or more, and the upper limit is 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 blasting treatment for removing paint on 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 blasting treatment, various blasting methods can be used, but a dry blasting 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.

As the compressed gas, compressed air is usually used. 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 for the blast treatment can be separated and recovered from the adhered substance by using a conventional post-treatment facility such as a cyclone, and can be reused.

[0038]

Example 1 Melamine resin was obtained by mixing 80 parts by weight of melamine, 20 parts by weight of urea, and 200 parts by weight of formaldehyde, adjusting the pH to 9 to 10, heating and reacting under reflux.

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

When this blast 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 the amount of fine powder scattered was also very small. . No damage was observed on the plastic surface.

Comparative Example 1 A projection material was produced in the same manner as in Example 1 except that the butadiene rubber was not added, and the same projection was performed.
The polishing power was the same as in Example 1, but the scattering amount of the fine powder was large.

[0042]

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 amount of scattering at the time of the blast processing can be reduced, and the attached matter can be efficiently removed and removed without damaging the surface of the resin product.

Claims (6)

[Claims] 1. A rubber is used in an amount of 0.1 to 100 parts by weight of a base resin.
A blasting material characterized by being mixed with 01 to 30 parts by weight. 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 rubber is SB.
R, BR, IR, EPM, EPDM, NBR, IIR,
A projectile comprising at least one of urethane rubber and silicone rubber. 4. The method according to claim 3, wherein the rubber is BR or SB.
R, urethane rubber and silicone rubber, one or more of them. 5. A shot material according to claim 1, wherein the compounding amount of the rubber is 0.05 to 20 parts by weight. 6. A blasting method comprising blasting a surface of an object to be blasted using the blasting material according to claim 1. Description: