JP2002239928A - Support base for coated abrasive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a convenient support base for a coated abrasive that can be operated lightly for polishing while used in manual work and can be picked up easily from under water in a container such as a bucket during the work. SOLUTION: The support base for a coated abrasive has micro hollows dispersed in an elastic body having an abrasive paper holding surface 2 of a gently convex arc section on at least one face. The opposite face to the abrasive paper holding surface is a plane 3 or a concave 5. The gently convex arc section has a radius of 50 to 120 mm. The micro hollows are formed by micro hollow spheres mixed to set the specific gravity of the elastic body after molding at 0.95 to 0.30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support base for abrasive cloth used mainly for polishing work in the field of sheet metal coating.

[0002]

2. Description of the Related Art In the course of painting or repairing a metal sheet of a vehicle, the final finishing work of restoring the base material before painting or obtaining a smooth surface on the base material by polishing and removing unnecessary protrusions is performed after the putty coating and polishing. Cloth is often used. In the finishing work, the outer shape of the vehicle is restored by a manual operation of a technician while holding the polishing cloth or the like on the support base for the polishing cloth paper, and the appearance after painting is almost the same as before.

In the process of restoring the outline to the original state and obtaining a smooth surface, different types of polishing tools are used depending on the degree of unevenness, but these often require polishing of a small (narrow) area. Many are made for the target. However, there is a case where the surface to be repaired has a relatively large area, but in such a case, there is no manual holder for holding the abrasive cloth moderately. In addition, during the polishing operation, in order to prevent adverse effects due to drying of the deposits such as putty, unused polishing tools are often constantly immersed in water in a container such as a bucket. At this time, the operator takes out the polishing tool sinking to the bottom of the container every time of use, and works. However, it takes time to remove the sinking tool, which impairs the workability.

[0004]

Therefore, the present inventor can perform the polishing operation lightly for manual use, and can easily take it out of the water in a container such as a bucket during the work. A convenient support base for abrasive cloth paper was studied.

[0005]

As a result of studying the above-mentioned problems, a support base for abrasive cloth paper in which minute hollows are scattered inside an elastic body having an abrasive paper holding surface having a loosely convex arc-shaped cross section on at least one surface. And The loose convex arc cross section mentioned here is a circular arc cross section having a radius of curvature of preferably 50 to 120 mm, more preferably 60 to 110 mm. A curvature having a radius of 50 mm or less is not preferable because it is inconvenient for polishing a relatively large area. Also, if the radius
If the curvature is more than 120 mm, it is not suitable for the purpose of holding the abrasive paper and making partial contact on the arc surface. The facing surface of the polishing paper holding surface is preferably a flat surface or a concave surface. With such a shape, the operator can easily hold the polishing paper in the palm, and a polishing surface having a small radius of curvature capable of polishing a small area can be formed on both sides of the polishing paper holding surface having an arc-shaped cross section.

[0006] In the micro hollow, the elastic body after forming the micro hollow sphere (micro capsule) has a specific gravity of 0.95 to 0.3, preferably 0.80 to 0.3.
It is preferable to form the mixture so as to be 0.40. When the specific gravity is 0.95 or more and is close to the specific gravity of water, the workability is lowered because it is difficult to float immediately when put into a container such as a bucket.
In order to make the specific gravity 0.3 or less, the composition ratio of the rubber component in the elastic body is reduced, and the physical values of the flexural modulus and the flexural strength are reduced, which is not preferable as a support base for abrasive cloth paper.

[0007] The micro hollow spheres are preferably thermal expansion type micro capsules. The thermal expansion type microcapsules are obtained by encapsulating a vaporized expanding agent in a partition wall of a hollow polymer compound. As the shell wall of the heat-expandable microcapsules, vinylidene chloride, acrylonitrile, copolymers of acrylonitrile and vinylidene chloride, copolymers of nitrile resins such as acrylonitrile and methacrylonitrile with methacrylic esters such as methyl methacrylate and ethyl methacrylate. Examples thereof include a polymer, a copolymer of a nitrile resin and an acrylate such as methyl acrylate or ethyl acrylate, and the like. Examples of the vaporizing expanding agent include hydrocarbons such as butane, tetramethylmethane, isopentane, normal pentane, normal heptane, normal octane and isomers thereof. When the rubber in which such microcapsules are dispersed is vulcanized at 140 to 160 ° C., the vaporizing expansive agent in the microcapsules thermally expands to break the partition walls to form a foam. What is necessary is just to expand at least several times by heat. Examples of the fine hollow spheres include commercially available Matsumoto Microsphere F-110D (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) and EXPANCEL 092-120DU (manufactured by EXPANCEL).

The rubber components constituting the elastic body include natural rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, chloroprene rubber, and ethylene rubber.
Ethylene-α-olefin copolymer rubber such as propylene rubber, nitrile rubber, hydrogenated nitrile rubber to which unsaturated carboxylic acid metal salt is added, alkylated chlorosulfonated polyethylene, chlorosulfonated polyethylene rubber, or the like And a reinforcing agent such as carbon black, a filler, a softening agent, an antioxidant, a vulcanization aid, a vulcanizing agent such as sulfur, and the like are added and mixed with this. Further, a soft PVC resin or a thermoplastic elastomer (TPE) can be used.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. 1 is a plan view of a support base for polishing cloth, FIG. 2 is a front view, and FIG. 3 is a side view. FIG. 4 is a perspective view showing a use state. As is apparent from these figures, the polishing cloth paper support base 1 is a semi-cylindrical elastic body having a polishing paper holding surface 2 having a loosely convex arc-shaped cross section on one side.
Is a flat surface 3. The loose and convex abrasive paper holding surface 2 has a radius of curvature of 100 mm. The long side a of the rectangular shape in plan view is 115 mm, the short side b is 70 mm, the maximum thickness h is about 26 mm,
It is an elastic body having a minute hollow.

Table 1 shows examples of specific gravity and performance in the case where EPDM and NR / SBR are used as examples in which minute hollows are formed in the rubber component constituting the elastic body. Table 2 shows other examples of the rubber component of the elastic body having a specific gravity of 0.95 to 0.3 within the target range together with a compounding example.

[0011]

[Table 1]

[0012]

[Table 2]

As can be seen from the above table, the support base for abrasive cloth paper of the present invention has a minute hollow in the main body in order to keep the specific gravity within the target range of 0.95 to 0.3 for the purpose of not sinking in water. However, a suitable method for this purpose is to mix a predetermined amount of hollow microspheres (microcapsules) before solidification and to mold them. The rubber component constituting the support is ethylene-α
-In the case of a thermoplastic resin such as an olefin-based copolymer rubber, a predetermined amount of fine hollow spheres is added together with a commonly used raw material blend and melted at 70 to 80 ° C., which is slightly higher than the melting point, and Into a mold that can be molded into the shape specified by the present invention 16
Injection press at 0-170 ° C.

[0014] The type of solidifying by vulcanization, such as natural rubber and polyisoprene rubber, includes a method of masticating the rubber with a roll and a method of masticating with a Banbury mixer. When kneading with a roll, after kneading the rubber with a roll, fine hollow spheres, a vulcanization retarder, magnesium oxide, other fillers and softeners added as needed together with the masticated rubber by a Banbury mixer ,
An antioxidant and the like are added, and then sulfur and a vulcanization accelerator are kneaded to obtain a rubber composition. On the other hand, when masticating with a Banbury mixer, after rubber and shaking agent are masticated with a Banbury mixer, microcapsules, a vulcanization retarder, magnesium oxide, and other additives added as necessary A rubber composition is obtained by adding a filler, a softening agent, an antioxidant, and the like, kneading the mixture, and then adding sulfur and a vulcanization accelerator using a roll maintained at 50 to 70 ° C. After the rubber composition thus obtained is molded, it is heated to 150 to 160 ° C suitable for vulcanization to obtain a support base for abrasive cloth paper.

FIG. 4 shows an example of a method of using the polishing cloth support base 1 of the present invention. Sandpaper or other abrasive cloth 4 is wound and held around the abrasive paper holding surface 2 of the abrasive cloth support base 1. Since the polishing paper holding surface 2 has a gentle convex shape, the polishing cloth paper 4 has a gentle convex shape and is in a contact state P close to a line rather than a surface contact with the surface to be polished.
When contacting on a flat surface, during reciprocating movement, the front edge becomes the grinding surface near the leading edge, and the trailing edge becomes the grinding surface when retreating, but in the present invention, the contact grinding surface is always the same, so unnecessary contact Do not. The contact polishing operation can be performed accurately and lightly. Further, a new portion of the mounted abrasive cloth 4 can be always brought into contact. This solves the problem that the contact polishing work becomes heavy when the polishing paper holding surface has a gentle convex shape and a flat surface, resulting in a planar contact state.

FIG. 5 is a perspective view showing another embodiment of the polishing cloth supporting base 1 of the present invention. A concave surface 5 is formed on the opposite side of the loose convex abrasive paper holding surface 2. In addition, polishing surfaces 6 and 7 having a small radius of curvature capable of polishing a small area are formed on both sides of the polishing paper holding surface 2 having a loose convex shape. Further, a through hole 8 is provided for weight reduction. With such a shape, it is easy for an operator to hold the polishing paper in the palm while holding it, and it is light and can be used by immediately changing the contact position even when a small area needs to be polished in the process of polishing a large area. There is.

[0017]

The polishing cloth supporting base of the present invention can perform the polishing operation lightly even when the polishing cloth is manually mounted and used. In addition, the workability can be improved because it can be easily taken out of the water in a container such as a bucket during work. A new part of the mounted abrasive cloth can always be used, and a polished surface with a good finish can be formed at all times, thus providing an easy-to-use support base for abrasive cloth.

[Brief description of the drawings]

FIG. 1 is a plan view of a support base for polishing cloth paper of the present invention.

FIG. 2 is a front view of the polishing cloth support base.

FIG. 3 is a side view of the polishing cloth paper support base.

FIG. 4 is a perspective view showing a use state of the polishing cloth support base.

FIG. 5 is a perspective view of a support base for polishing cloth paper of another embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 support base for abrasive cloth 2 abrasive paper holding surface 3 flat surface 4 abrasive cloth 5 concave surface 6 polished surface with small radius of curvature 7 polished surface with small radius of curvature 8 through hole

Claims (5)

[Claims] 1. A support base for abrasive cloth paper in which minute hollows are scattered inside an elastic body having an abrasive paper holding surface having a loosely convex circular arc cross section on at least one surface. 2. The support base for abrasive cloth paper according to claim 1, wherein the opposing surface of the abrasive paper holding surface is a flat surface or a concave surface. 3. A support base for abrasive cloth paper according to claim 1, wherein the gentle convex arc cross section has a curvature having a radius of 50 to 120 mm. 4. The support base for abrasive cloth paper according to claim 1, wherein minute hollows are formed by mixing minute hollow spheres so that the elastic body after molding has a specific gravity of 0.95 to 0.30. 5. The support base for polishing cloth paper according to claim 4, wherein the minute hollow spheres are heat-expandable microcapsules.