KR100937857B1 - Porous abrasive disks and preparation thereof - Google Patents

Abstract

The present invention relates to a porous abrasive disc and a method for manufacturing the same, comprising: dampproof paper; A first thermoset resin-impregnated, at least one carbon fiber leno fabric layer; And laminating one or more chemical fiber lenofabric layers, the second thermosetting resin-impregnation followed by dispersion coating of abrasive, wherein the abrasive disc of the invention has porosity and has dimensional stability, rotation by having lenofabric layers as a constituent layer. It has excellent breaking strength and impact resistance, which is safe and environmentally friendly, and can be used for polishing.

Description

POROUS ABRASIVE DISKS AND PREPARATION THEREOF}

The present invention relates to a safe and environmentally friendly porous abrasive disk and its manufacturing method having excellent dimensional stability, rotational fracture strength and impact resistance.

Abrasive discs often include a fiberglass fabric layer as a constituent layer. The cross-sectional structure of a glass fiber fabric layer-containing abrasive disk according to the prior art is shown in FIG. 1. In the conventional abrasive disc shown in FIG. 1 as a reinforcing material, a glass fiber cloth coated with an abrasive is dispersed by spraying an abrasive-containing slurry on a layer of a fiberglass fabric in the form of a disc impregnated with a thermosetting resin, followed by predrying. After the fabric layer is obtained, black paper and two glass fiber fabric layers are placed on a curved mold stand, followed by heating and pressing.

However, such a conventional abrasive disk has a low impact strength and rotational breakdown strength during the polishing process, causing fragmentation due to the edge of the polishing surface or a sudden impact, which is likely to cause a safety accident for the worker. It has a problem that it is not environmentally friendly, such as irritating the skin or adversely affecting the human body.

Accordingly, an object of the present invention is to provide an abrasive disc, and a method of manufacturing the same, which are excellent in dimensional stability, rotational breakdown strength, and impact resistance strength, which can significantly reduce safety accidents and labor pollution of workers.

The present invention to achieve the above object,

(1) dampproof paper;

(2) a first thermoset resin-impregnated, at least one carbon fiber leno fabric layer; And

(3) Provided is a polishing disk comprising a second thermosetting resin-impregnation followed by lamination of one or more layers of chemical fiber leno fabrics coated with an abrasive dispersion.

The abrasive disc of the present invention is porous by having leno fabric layers as a constituent layer, and has excellent dimensional stability, impact resistance and rotational breaking strength without including the fiberglass fabric layer used in the prior art. It protects and does not generate glass fiber dust, so it does not sting workers, so it can be useful for polishing.

The abrasive disk according to the present invention is a moisture-proof paper; A first thermoset resin-impregnated, one or more carbon fiber lenowoven layers; And a structure in which one or more chemical fiber leno fabric layers, in which the abrasive is dispersed and coated after the second thermosetting resin-impregnation, are laminated, having a porosity due to the leno fabric layers. Preferably, the abrasive disk of the present invention has a curved surface as a whole, and the moisture-proof paper, the first chemical fiber leno fabric layer, the carbon fiber leno fabric layer and the second chemical fiber leno fabric layer are sequentially stacked from the convex surface of the curved surface. Can be. In addition, the carbon fiber leno fabric layer and the chemical fiber leno fabric layer may be alternately laminated two or more times. The cross-sectional structure of an abrasive disc according to one embodiment of the present invention is shown in FIG. 2 (steel bushing plate is a plate normally mounted when the disc is applied to a polishing process, but is shown in the drawings but is an essential construction. Are not ingredients and have not been described separately).

Desiccant paper used in the present invention has a weight of 25 to 40 g / m ² and a thickness of 0.03 to 0.07 mm, low humidity of less than 3% when left for 24 hours at a relative humidity (RH) 40 to 80% It is appropriate to indicate the rate.

The carbon fiber fabric used in the present invention is impregnated with a thermosetting resin (first thermosetting resin) in an amount of 120 to 140 g / m 2 for a predetermined time and then preliminarily dried at 80 to 140 ° C. for 2 to 4 minutes, G75 1/4 H45 1/3 × G75 1/4 to H45 1/3 (inclined x weft) Fiber thickness of tex / yarn, weight of 200 to 300 g / m ² , and 6-12 x 6-12 (inclined x weft) It is desirable to have a lenno tissue of count / inch. In this case, the G and H means that the average diameter is 8.89 ~ 10.15 ㎛ and 10.16 ~ 11.42 ㎛, respectively, tex means the weight (g) of the fiber corresponding to 1000m length.

The first and second chemical fiber fabrics used in the present invention may be the same or different from each other, and after impregnating the thermosetting resin (second thermosetting resin) in an amount of 120 to 160 g / m 2 for a predetermined time, 80 to 140 as necessary. It may be obtained by predrying at 2 ° C. for 2 to 4 minutes, then spraying the abrasive, for example in an amount of 1600 g / m 2 and then predrying at 70 to 100 ° C. for 5 to 10 minutes. Preferably, the abrasive may be coated with a thermosetting resin (third thermosetting resin). Various types of abrasives coated with a third thermosetting resin are shown in FIG. 3. Further, in order to further improve the adhesion of the abrasive, the chemical fiber fabric may be further coated with the fourth thermosetting resin after the impregnation treatment with the second thermosetting resin and prior to the injection treatment with the abrasive.

The chemical fiber fabric may be polyester, nylon, vinylon (polyvinyl alcohol (PVA)), polyvinylidene chloride, polyvinyl chloride, acrylic, aramid, acetate, cotton, hemp, viscose, silk, wool or their It may be made of blended yarns.

The chemical fiber fabrics used in the present invention are 6 / 2-14 / 2 x 6 / 2-14 / 2 (inclined x weft) s / yarn fiber thickness, and 12-18 x 6-14 (inclined x weft) count It is desirable to have a 2-ply leno tissue of / inch. At this time, it is more preferable to have the thickness of the fiber of 12/2-14/2 x 8/2-10/2 (tilt x weft) s / yarn so that a thin thing and a thick thing may mix.

The first, second, third and fourth thermosetting resins consist of phenolic resins, polyester resins, epoxy resins, urea resins, melamine resins, diallyl phthalate prepolymer (DAPP) resins, modified thermosetting resins and mixtures thereof Each independently selected from the group. Preferably, the first, second and fourth thermosetting resins may be phenolic liquid resins or DAPP liquid resins having a solids content of 40 to 60% by weight and a viscosity (at 25 ° C) of 300 to 600 cps. Preferably, the third thermosetting resin used for coating the abrasive is a mixture of 55 to 70% by weight of phenolic powder resin (Novolak type) and 30 to 45% by weight of phenol liquid resin (Rezole type). In particular, the phenolic liquid resin preferably has a solid content of 60 to 75% by weight and a viscosity (at 25 ° C) of 300 to 600 cps.

The abrasive disc of the present invention, in place of abrasive cloth, comprises a dispersion coated abrasive layer, wherein the abrasive component is alumina (Al ₂ O ₃ ), silicon carbide (SiC), alumina zirconia (AZ), ceramic (sol- Gel), diamond or mixtures thereof. The abrasive may have a size of # 16 to # 60, and may be of the "P" or "F" standard.

According to a preferred embodiment of the present invention, the abrasive disk of the present invention having a curved surface as a whole may have an angle of 5 to 9 ° with the bottom line when the disc is placed on the floor, and the connecting line between the disc edge and the center of the inner concave surface. This shape provides for ease of operation during polishing.

According to the present invention, a moisture-proof paper, at least one carbon fiber leno fabric layer, and at least one chemical fiber leno fabric layer are laminated and heat pressed to bond the constituent layers to each other to produce the abrasive disc of the present invention.

As a specific example, the first chemical fiber leno fabric layer, the carbon fiber leno fabric layer, the second chemical fiber leno fabric layer and the moisture proof paper are sequentially stacked on the curved mold stand as shown in FIG. 5 the location of the same curved molded plastic plate shown and 4 to 8kgf / cm ^2, preferably 5 to 7 kgf / cm ² pressure was added to the 4 to 8 hours, preferably at 120 for 4 to 6 hours as shown in The abrasive disc of the present invention can be prepared by heating in an oven at from 180 ° C., preferably from 140 ° C. to 160 ° C., to melt the thermosetting resins impregnated in each fiber and abrasive and adhering the constituent layers to each other. At this time, the moisture-proof paper, the carbon fiber leno fabric layer and the chemical fiber leno fabric layer is used that is cut in the form of a disk of a desired size.

The mold firing plate used in the present invention has a rounded slope at the same angle as the mold stand.

The porous abrasive disc of the present invention manufactured as described above has excellent dimensional stability, impact resistance and rotational breaking strength to protect the worker from the risk of safety accidents, and does not generate glass fiber dust, which does not cause the operator to be environmentally friendly. It can be usefully used.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

EXAMPLE

Example 1

One moisture-proof paper (manufactured by Intellectual Culture Industry Co., Ltd.) having a weight of 25 g / m ² and a thickness of 0.05 mm was cut into an outer diameter of 112 mm and an inner diameter of 23 mm; Impregnated with phenolic resin KRD-745 (Kolong Emulsified) in an amount of 138.0 ± 1.0 g / m ² , followed by dry, 12/2 × 8/2 (slope × weft) s / yarn fiber thickness and 16 × 8 (slope) X weft) 2 sheets of polyester fiber fabric (file industry) having a 2-ply lenotextile of count / inch; And a fiber thickness of H45 1/3 × H45 1/3 (inclined x weft) tex / yarn and 8 × 8 (inclined x weft) count / inch leno texture, which was dried after impregnation with phenolic resin as described above. Each one of the carbon fiber fabrics (manufactured by Fiber Fiber Co., Ltd.) was cut into an outer diameter of 180 mm and an inner diameter of 23 mm.

Subsequently, 100 g of Al ₂ O ₃ of the "F" standard, # 24 particles and # 30 particles were mixed in a weight ratio of 30:70, phenol powder resin (Novolak) 1364K (manufactured by Gangnam Chemical), and phenol liquid resin (Rezole). 9.3 g of TD-2207 (70% solids, Gangnam Chemical) were mixed and stirred to produce an abrasive coated with a phenolic resin. Using a chemical fiber leno fabric layer production process as shown in Figure 4, 4.0g of a phenolic resin KRD-745 (Kolon Emulsified Product) as a coater to a phenolic resin-impregnated polyester fiber leno fabric in the form of a disk prepared in advance After impregnating and coating in an amount of / 7inch, the abrasive was spread on one surface in an amount of 40.0g / 7inch and pre-dried through a dryer to obtain an abrasive-dispersed coated polyester fiber leno fabric.

1 polyester fiber fabric and 1 carbon fiber fabric sequentially on a mold stand (an angle of 6 ° as a connecting line between the disc edge and the inner concave center when the disc is placed on the floor) and the bottom surface) After laminating one sheet of polyester fiber fabric and one sheet of moisture-proof paper, placing a mold baking plate thereon and applying a pressure of 6.0 kgf / cm ² , and putting the laminate into an electric oven at 160 ± 5 ° C. for 6 hours. The porous abrasive disc was made by heat curing during the process (see polishing disc cross-sectional structure shown in FIG. 2). At this time, the used mold baking plate had a round inclination of the same angle (6 degrees) as the mold stand.

Example 2

The polyester fiber fabric and carbon fiber fabric were impregnated in phenolic resin KRD-745 in an amount of 150.0 ± 1.0 g / m ² , respectively, and the polyester fiber fabric was 10 × 10 (inclined x weft) count / inch, 2-ply reno. Except having a tissue, the same process as in Example 1 was carried out to prepare a porous abrasive disk.

Example 3

Impregnating polyester fiber fabric and carbon fiber fabric in phenolic resin KRD-745 in an amount of 127.0 ± 1.0 g / m ² , and polyester fiber fabric being 12/2 × 12/2 (inclined weft) s / yarn Except having a fiber thickness of, the same process as in Example 1 was carried out to prepare a porous abrasive disk.

Example 4

A porous abrasive disk was manufactured by following the same process as Example 1, except that nylon fiber fabric (file industry product) was used instead of polyester fiber fabric.

Example 5

The use of vinylon (polyvinyl alcohol) fiber fabrics (file industry) instead of polyester fiber fabrics and the amount of polyvinyl alcohol fiber fabrics and carbon fiber fabrics in phenolic resin KRD-745, respectively, of 140.0 ± 1.0 g / m ² Except that impregnated with, the same process as in Example 1 was carried out to prepare a porous abrasive disk.

Example 6

Except for using acrylic fiber fabrics (file industry) instead of polyester fiber fabrics and impregnating acrylic fiber fabrics and carbon fiber fabrics in phenolic resin KRD-745 in an amount of 135.0 ± 1.0 g / m ² , respectively. To carry out the same process as in Example 1 to prepare a porous abrasive disk.

Comparative Example 1

One moisture-proof paper (manufactured by Intellectual Culture Industry Co., Ltd.) having a weight of 25 g / m ² and a thickness of 0.05 mm was cut into an outer diameter of 112 mm and an inner diameter of 23 mm; And fiber thickness of H45 1/4 × H45 1/4 (inclined x weft) tex / yarn and impregnated with phenolic resin KRD-745 in an amount of 138.0 ± 1.0 g / m ² , and 8 × 8 (inclined x weft) ) glass fiber fabric No. Two sheets of 389 (manufactured by Fiber Korea Corporation) were cut into sizes of 180 mm outer diameter and 23 mm inner diameter.

Subsequently, 100 g of Al ₂ O ₃ of the "F" standard, # 24 particles and # 30 particles were mixed in a weight ratio of 30:70, phenol powder resin (Novolak) 1364K (manufactured by Gangnam Chemical), and phenol liquid resin (Rezole). 9.3 g of TD-2207 (70% solids, Gangnam Chemical) were mixed and stirred to produce an abrasive coated with a phenolic resin. The phenolic resin-impregnated glass fiber fabric in the form of a disc prepared in advance was impregnated and coated with phenolic resin KRD-745 (Kolong Emulsified Product) in an amount of 4.0 g / 7 inch with a coater, and then the above-mentioned on both sides (front and back), respectively. The abrasive was sprayed in an amount of 30.0 g / 7 inch and air dried to obtain an abrasive-dispersed coated fiberglass fabric.

Lay the two fiberglass fabrics and one moisture proof paper on a mold stand (an angle of 6 ° as the connecting line between the disc edge and the inner concave center when the disc is placed on the floor) with the bottom surface. After placing the mold firing plate thereon and applying a pressure of 6.0 kgf / cm ² , the laminate was placed in an electric oven at 160 ± 5 ° C. and heat-cured for 6 hours to prepare an abrasive disc (polishing shown in FIG. 1). Disc section structure). At this time, the used mold baking plate had a round inclination of the same angle (6 degrees) as the mold stand.

Comparative Example 2

After manufacturing three phenolic resin-impregnated polyester fiber fabrics in the form of disc in the same manner as in Example 1, two abrasive-dispersed coated polyester fiber fabrics were sprayed by spraying only two of the three Got it.

Thereafter, a porous abrasive disc was manufactured by performing the same process as in Example 1 using phenol resin-impregnated carbon fiber fabric instead of phenol resin-impregnated carbon fiber fabric.

Test Example: Property Test

For each of the abrasive disks prepared in Examples 1 to 6, and Comparative Examples 1 and 2, impact strength, rotational fracture strength, dimensional stability, operator skin irritation degree, and service time (life) were measured, and the results are shown in Table 1 below. Shown in

As can be seen from Table 1, the abrasive disks prepared in Examples 1 to 6 are relatively excellent in impact resistance, rotational breakdown strength and dimensional stability, whereas Comparative Examples 1 and 2 are weak in impact strength, Comparative Example 1 Is particularly irritating to the operator's skin.

1 is a cross-sectional view of a conventional fiberglass fabric layer-containing abrasive disk,

2 is a cross-sectional view of an abrasive disk according to one embodiment of the present invention,

3 is a schematic diagram showing various types of abrasives coated with a thermosetting resin,

Figure 4 is a schematic diagram of a chemical fiber leno fabric layer production process that continuously performs a resin impregnated coating, abrasive spray and drying process for the fabric,

5 is a schematic diagram of a curved mold stand and a mold firing plate used to produce an abrasive disk according to the present invention.

Claims (13)

(1) dampproof paper; (2) a first thermoset resin-impregnated, at least one carbon fiber leno fabric layer; And (3) A polishing disk comprising a second thermosetting resin-impregnation followed by lamination of one or more layers of chemical fiber leno fabrics coated with an abrasive dispersion. The method of claim 1, An abrasive disc having a curved surface as a whole, wherein moisture-proof paper, a first chemical fiber leno fabric layer, a carbon fiber leno fabric layer, and a second chemical fiber leno fabric layer are sequentially stacked from the convex surface of the curved surface. The method of claim 2, An abrasive disc, characterized in that when the disc is placed on the floor, the connecting line between the disc edge and the center of the inner concave surface forms an angle of 5 to 9 ° with the bottom surface. The method of claim 1, Carbon fiber leno fabric is G75 1/4 to H45 1/3 × G75 1/4 to H45 1/3 (inclined x weft) Fiber thickness of tex / yarn (where G and H each have an average diameter of 8.89 to 10.15 µm) And 10.16 to 11.42 μm), a weight of 200 to 300 g / m ² , and a leno texture of 6 to 12 × 6 to 12 (tilt × weft) count / inch. The method of claim 1, An abrasive disc, characterized in that the abrasive is coated with a third thermosetting resin. The method of claim 1, And a chemical fiber leno fabric coated with a fourth thermosetting resin after the impregnation treatment with the second thermosetting resin and prior to the coating of the abrasive. The method of claim 1, Chemical fiber leno fabrics are polyester, nylon, vinylon (polyvinyl alcohol (PVA)), polyvinylidene chloride, polyvinyl chloride, acrylic, aramid, acetate, cotton, hemp, viscose, silk, wool or their An abrasive disk, characterized in that consisting of blended yarns. The method of claim 1, 2-fiber of chemical fiber leno fabric 6 / 2-14 / 2 x 6 / 2-14 / 2 (inclined x weft) s / yarn fiber thickness and 12-18 x 6-14 (inclined x weft) count / inch An abrasive disc, having a lennosic structure. The method of claim 8, An abrasive disk, wherein the chemical fiber leno fabric has a thickness of fibers of 12/2 to 14/2 x 8/2 to 10/2 (inclined x weft) s / yarn. The method according to any one of claims 1, 2, 5 and 6, And said thermosetting resin is selected from the group consisting of phenol resins, polyester resins, epoxy resins, urea resins, melamine resins, diallyl phthalate prepolymer resins, modified thermosetting resins and mixtures thereof. The method of claim 5, wherein And the third thermosetting resin is a mixture of 55 to 70 wt% of phenolic powder resin and 30 to 45 wt% of phenolic liquid resin. A method of manufacturing the abrasive disc of claim 1 comprising laminating a moisture proof paper, at least one carbon fiber leno fabric layer and at least one chemical fiber leno fabric layer and bonding the components to each other by heat compression. The method of claim 12, Heat pressing is carried out at a pressure of 4 to 8 kgf / cm ² and a temperature of 120 to 180 ° C.

Images