JP7775592B2 - Molded body and manufacturing method thereof, kneaded body and manufacturing method thereof, and polishing body and manufacturing method thereof - Google Patents

Description

This disclosure relates to a molded body and a manufacturing method thereof, a manufacturing method for a kneaded material, and an abrasive body and a manufacturing method thereof.

Patent Document 1 discloses a method for producing a composite recycled sheet using polyvinyl chloride resin as part of the raw materials.

Japanese Patent Application Laid-Open No. 2005-82802

However, conventional methods have not been able to produce polyvinyl chloride-containing products with a sufficiently high modulus of elasticity from polyvinyl chloride resin. The purpose of this disclosure is to solve this problem.

A method for producing a molded article according to one aspect of the present disclosure includes the following steps.
(A) A step of kneading a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer with at least one type of fiber selected from the group consisting of polypropylene fiber, nylon 6 fiber, and nylon 66 fiber at a temperature of 141 to 280°C to obtain a kneaded product.
(B) A step of processing the kneaded mixture into a molded product.

A molded article according to one aspect of the present disclosure comprises a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer, and at least one type of fiber selected from the group consisting of polypropylene fiber, nylon 6 fiber, and nylon 66 fiber, and satisfies at least one of a tensile modulus of elasticity of 21 MPa or greater and a compressive modulus of elasticity of 8 MPa or greater.

A method for producing a kneaded product according to one aspect of the present disclosure includes a step of kneading a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer with at least one type of fiber selected from the group consisting of polypropylene fiber, nylon 6 fiber, and nylon 66 fiber at a temperature of 141 to 280°C.

A method for manufacturing an abrasive body according to one aspect of the present disclosure includes the following steps.
(A1) A step of kneading a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer, at least one type of fiber selected from the group consisting of polypropylene fiber, nylon 6 fiber, and nylon 66 fiber, and an abrasive under a temperature condition of 141 to 280°C to obtain a kneaded product.
(B1) A step of forming the kneaded material into an abrasive body.

The method for manufacturing an abrasive body may be as follows. That is, the method for manufacturing an abrasive body may include: (A2) a step of kneading a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer with at least one type of fiber selected from the group consisting of polypropylene fiber, nylon 6 fiber, and nylon 66 fiber at a temperature of 141 to 280°C to obtain a kneaded mixture; and (B2) a step of molding the kneaded mixture into an abrasive body, wherein the content of the fibers in the kneaded mixture is 10 to 80 mass% based on the mass of the kneaded mixture. Furthermore, the method for manufacturing an abrasive body may include: (A3) a step of kneading a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer with an abrasive at a temperature of 141 to 280°C to obtain a kneaded mixture; and (B3) a step of molding the kneaded mixture into an abrasive body, wherein the content of the abrasive in the kneaded mixture is 5 to 80 mass% based on the mass of the kneaded mixture. Furthermore, the method for manufacturing an abrasive body may include (A4) a step of kneading a matrix resin composition containing at least polyvinyl chloride resin, at least one type of fiber selected from the group consisting of polypropylene fiber, nylon 6 fiber, and nylon 66 fiber, and an abrasive at a temperature of 141 to 280°C to obtain a kneaded mixture, and (B4) a step of molding the kneaded mixture into an abrasive body.

An abrasive body according to one aspect of the present disclosure comprises a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer, at least one type of fiber selected from the group consisting of polypropylene fiber, nylon 6 fiber, and nylon 66 fiber, and an abrasive.

The abrasive body may be in the following form. That is, the abrasive body may contain a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer, and at least one type of fiber selected from the group consisting of polypropylene fibers, nylon 6 fibers, and nylon 66 fibers, with the fiber content being 10 to 80 mass% (based on the total mass of the abrasive body). Alternatively, the abrasive body may contain a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer, and an abrasive, with the abrasive content being 5 to 80 mass% (based on the total mass of the abrasive body). Furthermore, the abrasive body may contain a matrix resin composition containing at least polyvinyl chloride resin, at least one type of fiber selected from the group consisting of polypropylene fibers, nylon 6 fibers, and nylon 66 fibers, and an abrasive.

The present disclosure provides a molded body useful for producing polyvinyl chloride-containing products with a sufficiently high elastic modulus, a method for manufacturing the same, and a method for manufacturing a kneaded product. The present disclosure also provides an abrasive body, which is one embodiment of the above molded body, and a method for manufacturing the same.

FIG. 1 is a cross-sectional view schematically showing an example of a tile carpet. FIG. 2 is a cross-sectional view schematically illustrating an example of a molded article according to the present disclosure. 3(a) and 3(b) are scanning electron microscope images of the fibers contained in the molded article according to Example 1. FIG. 4(a) and 4(b) are scanning electron microscope images of the sample obtained after the polyvinyl chloride resin and the plasticizer were extracted and removed from the molded article according to Example 3. FIG.

Embodiments of the present disclosure will be described in detail below with reference to the drawings. However, the present disclosure is not limited to the following embodiments. The following embodiments illustrate the production of a molded article containing polypropylene fibers, but nylon fibers (at least one of nylon 6 fibers and nylon 66 fibers) may be included instead of polypropylene fibers, or both polypropylene fibers and nylon fibers (at least one of nylon 6 fibers and nylon 66 fibers) may be included.

The method for producing a molded article according to this embodiment includes the following steps.
(A) A step of kneading a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer with polypropylene fibers at a temperature of 141 to 280°C to obtain a kneaded product.
(B) A step of processing the kneaded mixture into a molded product.
Here, polyvinyl chloride resin is a resin synthesized by addition polymerization of vinyl chloride monomer (CH ₂ ═CHCl). Polyvinyl chloride resin is hard by itself, but it becomes soft by adding a plasticizer to polyvinyl chloride resin. Compositions containing polyvinyl chloride resin and a plasticizer are used, for example, in tile carpets, flexible films, hoses, and automotive interior and exterior components.

According to the above manufacturing method, by passing through step (A), a molded article with a sufficiently high elastic modulus can be produced. For example, when the kneading temperature in step (A) is 141 to 169°C, this temperature is close to the melting point of the polypropylene fibers. Therefore, in the molded article produced through step (B), the polypropylene fibers have intertwined points where the polypropylene fibers are thermally fused together. It is presumed that the polypropylene fibers in this state function as a reinforcing material (see Figures 3(a) and 3(b)). On the other hand, for example, when the kneading temperature in step (A) is higher than 170°C but not higher than 280°C, the polypropylene fibers melt. In particular, if the polypropylene in the polypropylene fibers is not acid-modified or has low compatibility with other resins such as nylon, it is presumed that polypropylene aggregates become mixed into the kneaded product. Therefore, the molded article produced from this kneaded product has a high elastic modulus. The kneading temperature may be 201 to 220°C, 221 to 245°C, 246 to 265°C, or 266 to 280°C.

Kneading temperatures of 200°C or less can suppress thermal degradation of polyvinyl chloride resin. If suppressing thermal degradation of polyvinyl chloride resin is particularly important, the kneading temperature should preferably be 169°C or less. On the other hand, if a high elastic modulus of the molded product is particularly important, the kneading temperature should preferably be between 170°C and 200°C. Note that the kneading temperature here refers to the set temperature of the kneading device, and it is estimated that the temperature of the kneaded product is approximately 1 to 20°C higher than the set temperature. This temperature difference is due to shear heat generated during kneading.

The polypropylene fiber material may be a polypropylene homopolymer (melting point: approximately 170°C) or a copolymer of propylene and other monomers (e.g., ethylene). The melting point of polypropylene fibers varies depending on the degree of polymerization and crystallinity of the polypropylene, and the type and content of other monomers. In order to determine the temperature range in which polypropylene fibers are thermally fused to each other at their intertwining points, tests may be conducted in which the polypropylene fibers are repeatedly heated under multiple temperature conditions.

This embodiment will be described below using the example of manufacturing a molded product (e.g., a sheet, film, tube, cup, or block) from a carpet tile. The carpet tile 10 shown in FIG. 1 includes a pile layer 1 composed of pile yarns and a base layer 3 in which some of the pile yarns are embedded. In this embodiment, the base layer 3 has a two-layer structure, consisting of an intermediate layer 3a in contact with the pile layer 1 and a base layer 3b. The thickness of the intermediate layer 3a is, for example, 0.1 to 5 mm. The thickness of the base layer 3b is, for example, 1 to 10 mm. The thickness of the base layer 3 (the sum of the thicknesses of the intermediate layer 3a and the base layer 3b) is, for example, 1.1 to 15 mm. The carpet tile 10 may be scrap material generated during the manufacturing process or used material disposed of by a general household or office.

The pile layer 1 is composed of pile yarns made of a fibrous material. In this embodiment, the pile yarns are made of polypropylene fibers. The pile layer 1 may also contain other synthetic or natural fibers. Examples of synthetic fibers include polyester fibers, nylon fibers, and acrylic fibers. Examples of natural fibers include linen, cotton, and wool. The pile layer 1 is formed, for example, by warp pile weaving or weft pile weaving. The pile layer 1 may be formed, for example, by implanting pile yarns using a tufting machine, or by adhering the pile yarns using an adhesive. The pile configuration may be either cut pile or loop pile.

The intermediate layer 3a is sandwiched between the pile layer 1 and the base layer 3b. Some of the pile yarns are embedded in the intermediate layer 3a, which serves to secure the pile layer 1 and bond the pile layer 1 to the base layer 3b. The intermediate layer 3a is made of a composition containing polyvinyl chloride resin, a plasticizer, and a filler, and contains resin fibers (e.g., PET fibers). The plasticizer is used to impart flexibility to the polyvinyl chloride resin. The filler is used, for example, to improve the dimensional stability of the tile carpet 10. The resin fibers are used to bind the pile yarns of the pile layer 1 together.

Examples of plasticizers include dioctyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), di-2-ethylhexyl adipate (DOA), diisononyl adipate (DINA), tri-2-ethylhexyl trimellitate (TOTM), and tricresyl phosphate (TCP).

Examples of fillers include calcium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, magnesium hydroxide, aluminum hydroxide, and glass powder. Of these, calcium carbonate is preferred from the standpoints of economy and processability.

The base layer 3b forms the back surface of the tile carpet 10. The base layer 3b is made of a composition containing polyvinyl chloride resin and a plasticizer. The plasticizer may be the same as that contained in the intermediate layer 3a. The base layer 3b may or may not contain the above-mentioned filler.

When tile carpet is used as at least part of the raw material for the molded body, step (a1) of crushing tile carpet 10 can be carried out before step (A). In this case, crushed tile carpet 10 in its entirety can be used as at least part of the matrix resin composition. Crushed base layer 3 can also be used as at least part of the matrix resin composition. When the pile yarn contains polypropylene fiber, crushed pile yarn can be used as at least part of the polypropylene fiber in step (A).

In step (a1), the tile carpet 10 is crushed to prepare the raw material for the kneaded material. The tile carpet 10 can be crushed using a known crushing device. A known crushing device can be used to pulverize the tile carpet 10 into powder. It is preferable to crush the tile carpet 10 with an intensity and processing time that results in a particle size of 10 mm or less (excluding crushed pile yarns). The particle size of the crushed material is more preferably 5 mm or less, and even more preferably 2 mm or less. A particle size of 2 mm or less of the crushed material tends to result in a uniform kneaded material in a relatively short processing time in step (A). The lower limit of the particle size of the crushed material is, for example, 0.1 mm. A particle size of 0.1 mm or more of the crushed material tends to prevent the crushed material from becoming excessively bulky and reducing handleability. The particle size of the crushed material can be determined by preparing multiple sieves with different mesh sizes and determining whether the crushed material passes through the sieves.

All of the raw materials for the kneaded material may be crushed tile carpet 10, or part of the raw materials for the kneaded material may be crushed tile carpet and used in combination with other materials. Examples of other materials include polyvinyl chloride resin and polypropylene fibers not derived from tile carpet. The amount of polyvinyl chloride resin to be blended may be determined depending on the intended use of the molded product and the desired performance, etc. From the perspective of effective use of tile carpet 10, the amount of crushed tile carpet 10 used per 100 parts by mass of the raw materials for the kneaded material is preferably 50 parts by mass or more, more preferably 80 parts by mass or more.

It is preferable that at least a portion of the polypropylene fibers have a length of 2 mm or more (more preferably 3 to 8 mm). This further enhances the reinforcing effect of the polypropylene fibers. Polypropylene fibers not derived from the tile carpet 10 may be used, for example, when the length of the crushed pile yarn is excessively short. To prevent the polypropylene fibers that make up the pile yarn from becoming excessively short due to crushing, the pile layer 1 and base layer 3 may be separated before crushing the tile carpet 10, and the pile layer 1 may be crushed under different conditions than those for the base layer 3, as necessary.

The polypropylene fiber content in the kneaded product is preferably 5 to 95 parts by mass, more preferably 10 to 90 parts by mass, and may be 10 to 40 parts by mass or 40 to 70 parts by mass, relative to 100 parts by mass of the total mass of the kneaded product. Having a polypropylene fiber content within this range allows for the production of a molded article with a high elastic modulus from the kneaded product.

In step (B), the kneaded material is processed into a molded product. Sheet- or film-shaped molded products can be produced by known plastic sheet molding methods such as the calendar method or T-die method. Cylindrical molded products (e.g., tubes) can be produced by known plastic molding methods such as extruders, blow molding machines, or injection molding machines. Blocks of a predetermined shape can be produced using a mold or extruder. When producing sheet-shaped molded products (e.g., 0.1 to 10 mm thick), it is preferable to complete the molded product by pressing the sheet during production under specified temperature and pressure conditions. The pressing temperature is preferably the same as the kneading temperature (141 to 280°C), and preferably 141 to 169°C to suppress thermal degradation of the polyvinyl chloride resin. To obtain a molded product with a high elastic modulus, it is preferably 170 to 200°C, or even 200 to 280°C. The pressing pressure is preferably 5 to 30 MPa, more preferably 10 to 20 MPa. Additionally, parts with uneven shapes, such as cups, bats, and bowls, can be manufactured using known plastic molding methods such as injection molding machines and press molding machines.

By keeping the pressing temperature at 200°C or less, thermal degradation of the polyvinyl chloride resin can be suppressed. If suppressing thermal degradation of the polyvinyl chloride resin is particularly important, the pressing temperature is preferably 169°C or less. On the other hand, if a high elastic modulus of the molded product is particularly important, the pressing temperature is preferably 170°C or higher.

Figure 2 is a cross-sectional view showing a schematic example of a sheet-like molded product manufactured through a pressing process. The sheet-like molded product 20 is composed of a matrix resin composition 5 and polypropylene fibers 7. The polypropylene fibers 7 are contained in a state where they have intertwined points where the polypropylene fibers 7 are thermally fused together. Due to the reinforcing effect of the polypropylene fibers 7, the sheet-like molded product 20 has a sufficiently high elastic modulus.

The molded article satisfies at least one of the following conditions: a tensile modulus of elasticity of 21 MPa or greater and a compressive modulus of elasticity of 8 MPa or greater. The tensile modulus of the molded article is preferably 21 MPa or greater, more preferably 180 MPa or greater, even more preferably 270 MPa or greater, and even more preferably 330 MPa or greater. The modulus of elasticity here can be determined by cutting a test piece of a specified size (e.g., 120 mm long x 10 mm wide) from the molded article and subjecting this test piece to a tensile test. The tensile test is conducted in an atmosphere of 23°C and 50% RH, with a chuck distance of 50 mm and a tensile speed of 50 mm/min, and the modulus of elasticity is calculated for strains between 0.0005 and 0.0025. The compressive modulus of the molded article is preferably 8 MPa or greater, more preferably 170 MPa or greater, even more preferably 210 MPa or greater, and even more preferably 380 MPa or greater. The elastic modulus referred to here is the elastic modulus calculated from the region of the stress-strain curve where stress and strain are linearly related when a compression test is performed on a molded body with a diameter of 28 mm and a thickness of 21 mm at a compression rate of 5 mm/min in an atmosphere of 23°C and 50% RH.

As described above, the method for manufacturing a molded article according to this embodiment makes it possible to produce a molded article having a sufficiently high elastic modulus from tile carpet 10. By using offcuts generated during the manufacturing process or used carpet tile 10 that is disposed of by ordinary households or offices as tile carpet 10, these materials, which have traditionally been disposed of primarily in landfills, can be effectively utilized. According to the above embodiment, a kneaded product is obtained in which thermal degradation is sufficiently suppressed. Therefore, according to this embodiment, a recycle efficiency of, for example, 70% or more can be achieved. Here, recycle efficiency refers to the ratio of the mass of waste (e.g., discarded tile carpet) to the total mass of the waste and virgin materials when manufacturing a molded article using the waste. From the perspective of effective waste utilization, the recycle efficiency is preferably 80% or more, more preferably 90% or more, and even more preferably 100%.

An example of a molded product that uses waste (e.g., discarded carpet tiles) as at least part of the raw material is an abrasive body. The abrasive body contains a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer, at least one type of fiber selected from the group consisting of polypropylene fibers, nylon 6 fibers, and nylon 66 fibers, and an abrasive. The kneaded material for the abrasive body can be prepared in the same manner as described above, except that an abrasive is added to the kneaded material. The shape of the abrasive body can be, for example, a disk, disc, or rod. A disk-shaped or disc-shaped abrasive body can be attached to a disc grinder for use. The diameter of the disk-shaped or disc-shaped abrasive body is, for example, 3 to 300 mm, and the thickness is, for example, 1 to 200 mm. A rod-shaped abrasive body can be used as a handheld type.

The abrasive is, for example, an inorganic material, specific examples of which include calcium carbonate particles, alumina particles, and diamond particles. It is believed that the polyvinyl chloride resin acts as an adhesive, while the polyvinyl chloride resin and fibers (nylon fibers and/or polypropylene fibers) act as a cushion. This prevents the abrasive from causing deeper scratches than necessary on the object being polished. The abrasive content of the polishing body is, for example, 5 to 80% by mass, preferably 10 to 70% by mass, and more preferably 30 to 60% by mass. The fiber content of the polishing body is, for example, 10 to 80% by mass, preferably 10 to 70% by mass, and more preferably 20 to 60% by mass. The fiber referred to here is at least one type of fiber selected from the group consisting of polypropylene fiber, nylon 6 fiber, and nylon 66 fiber.

Although the embodiments of the present disclosure have been described in detail above, the present invention is not limited to the above embodiments. For example, while the above embodiments illustrate tile carpets having a two-layer base layer, the base layer may be a single layer or a laminated structure of three or more layers.

In the above embodiment, the pile yarn is made of polypropylene fiber, and other polypropylene fibers are used in combination as needed. However, if the pile yarn is made of a fiber other than polypropylene fiber (for example, at least one of nylon 6 fiber and nylon 66 fiber), a kneaded mixture can be prepared by blending polypropylene fiber with crushed tile carpet material.

In the above embodiment, an example was given of a molded article being manufactured from tile carpet, but the molded article may also be manufactured from products containing polyvinyl chloride resin (e.g., flexible films, tubes, and automobile interior and exterior components) other than tile carpet.

In the above embodiment, an example was given of producing a molded article containing polypropylene fibers. However, nylon fibers (at least one of nylon 6 fibers and nylon 66 fibers) may be used instead of polypropylene fibers, or both polypropylene fibers and nylon fibers (at least one of nylon 6 fibers and nylon 66 fibers) may be used. The nylon fiber content in the kneaded product is preferably 6 to 80 parts by mass, more preferably 20 to 70 parts by mass, or may be 20 to 50 parts by mass or 50 to 70 parts by mass, based on 100 parts by mass of the total mass of the kneaded product. Having a nylon fiber content within this range enables the production of a molded article with a high elastic modulus from the kneaded product. The total amount of fibers in the kneaded product is preferably 10 to 95 parts by mass, more preferably 20 to 80 parts by mass, or may be 20 to 60 parts by mass or 30 to 70 parts by mass, based on 100 parts by mass of the total mass of the kneaded product. Having a nylon fiber content within this range enables the production of a molded article with a high elastic modulus from the kneaded product.

When kneading is performed at temperatures close to the melting point of the nylon fibers, the nylon fibers will have entangled points where they are thermally fused together within the molded product, and it is believed that these nylon fibers act as reinforcing materials in this state. On the other hand, when kneading is performed at temperatures well above the melting point of the nylon fibers, the nylon fibers will melt, and if the resin other than nylon has low compatibility with nylon, it is believed that clumps of nylon will become mixed into the kneaded product. For this reason, molded products made from this kneaded product have a high elastic modulus.

In the above embodiment, one form of abrasive body was exemplified as comprising a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer, at least one type of fiber selected from the group consisting of polypropylene fibers, nylon 6 fibers, and nylon 66 fibers, and an abrasive. However, the abrasive body does not have to contain an abrasive. That is, the abrasive body may comprise a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer, and at least one type of fiber selected from the group consisting of polypropylene fibers, nylon 6 fibers, and nylon 66 fibers. The fiber content in this abrasive body is, for example, 10 to 80 mass%, preferably 10 to 70 mass%, and more preferably 20 to 60 mass%. This abrasive body can be manufactured by (A2) kneading a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer with at least one type of fiber selected from the group consisting of polypropylene fibers, nylon 6 fibers, and nylon 66 fibers at a temperature of 141 to 280°C to obtain a kneaded mixture.

The abrasive body comprises an abrasive and a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer, and may not contain at least one type of fiber selected from the group consisting of polypropylene fibers, nylon 6 fibers, and nylon 66 fibers. The abrasive content in this abrasive body is, for example, 5 to 80 mass%, preferably 10 to 70 mass%, and more preferably 30 to 60 mass%. This abrasive body can be manufactured through the steps of (A3) kneading a matrix resin composition containing at least polyvinyl chloride resin and a plasticizer with the abrasive at a temperature of 141 to 280°C to obtain a kneaded mixture, and (B3) molding the kneaded mixture into an abrasive body.

The abrasive body comprises a matrix resin composition containing at least polyvinyl chloride resin, at least one type of fiber selected from the group consisting of polypropylene fibers, nylon 6 fibers, and nylon 66 fibers, and an abrasive, and may be free of plasticizers. The fiber content in this abrasive body is, for example, 10 to 80% by mass, preferably 10 to 70% by mass, and more preferably 20 to 60% by mass. The abrasive content in this abrasive body is, for example, 5 to 80% by mass, preferably 10 to 70% by mass, and more preferably 30 to 60% by mass. This abrasive body can be manufactured by (A4) kneading a matrix resin composition containing at least polyvinyl chloride resin and an abrasive at a temperature of 141 to 280°C to obtain a kneaded mixture, and (B4) molding the kneaded mixture into an abrasive body. Furthermore, a matrix resin that is substantially free of plasticizer can be obtained from ground tile carpet containing polyvinyl chloride resin and plasticizer by, for example, contacting the ground tile carpet with a solvent and dissolving the plasticizer in the solvent, or by volatilizing the plasticizer by heating the ground tile carpet to a temperature higher than the volatilization temperature of the plasticizer.

The molded articles of the present invention can be used, for example, for automobile parts, electrical and electronic parts, consumer goods, construction materials, medical materials, radiation shielding materials, agricultural materials, fisheries materials, and tools, but are preferably used for automobile parts. Furthermore, they often contain fillers, making them suitable for use in sound insulation materials, vibration damping materials, and sliding components.

The present disclosure will be explained below using examples and comparative examples, but the present invention is not limited to the following examples.

In order to produce recycled polyvinyl chloride resin, the following tile carpets were prepared.
<Tile carpet>
Layer structure: pile layer / middle layer (base layer) / base material layer (base layer)
Composition of tile carpet Polyvinyl chloride resin (PVC): 100 parts by mass Plasticizer (dioctyl phthalate, DOP): 100 parts by mass Nylon fiber (C): 120 parts by mass PET fiber: 47 parts by mass Calcium carbonate (CaCO ₃ ): 300 parts by mass

<Preparing ingredients>
(Tile carpet crushed material A)
Ground tile carpet (particle size: about 0.1 to 4 mm) was prepared.
(Polypropylene fiber B)
Polypropylene fibers were prepared by cutting at least a portion of the fibers constituting the pile layer of a tile carpet (model number: PX-3000) manufactured by Suminoe Textile Co., Ltd. to a length of 2 mm or more. The diameter of the polypropylene fibers was approximately 20 μm.
(Nylon fiber C)
Nylon fiber (diameter: 20 to 50 μm, length: approximately 4 mm) recovered from a crushed waste carpet tile was used. The composition of nylon fiber C was 100 parts by mass of nylon 6 fiber and 100 parts by mass of nylon 66 fiber.
(Polyvinyl chloride resin pulverized material D)
Ground material (particle size: approximately 0.1 to 4 mm) of the base layer of a tile carpet was prepared. The composition of the ground polyvinyl chloride resin D was 100 parts by mass of polyvinyl chloride, 100 parts by mass of a plasticizer (dioctyl phthalate, DOP), and 300 parts by mass of calcium carbonate.
(Nylon fiber E)
Nylon fibers were prepared by cutting at least a portion of the fibers constituting the pile layer of a tile carpet (model number: GA-100) manufactured by Toli into lengths of 2 mm or more.
(Polyvinyl chloride resin pulverized product F)
The polyvinyl chloride resin pulverized material F was prepared by removing the plasticizer from the polyvinyl chloride resin pulverized material D. The composition of the polyvinyl chloride resin pulverized material F was 100 parts by mass of polyvinyl chloride and 300 parts by mass of calcium carbonate.
(Polyvinyl chloride resin G)
Polyvinyl chloride resin (product code: 223-00255) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. was prepared.

<Production of Sheet-Like Molded Product>
Example 1
A mixture containing 45 g of pulverized material A (90 parts by mass) and polypropylene fiber B (10 parts by mass) was prepared. The mixture was kneaded in a batch mixer at a set temperature of 141°C for 5 minutes. This batch mixer had two blades (diameter: 30 mm), which were configured to rotate in opposite directions. One blade rotated at a speed of 60 rpm, and the other blade rotated at a speed of 90 rpm. The resulting mixture was pressed at a temperature of 157°C and a pressure of 5 MPa to obtain a sheet-like molded product with a thickness of approximately 1 mm. Observation of the cross section of the sheet-like molded product using a scanning electron microscope confirmed that some of the fibers were thermally fused together.

Example 2
A sheet-like molded product (thickness: about 1 mm) was obtained in the same manner as in Example 1, except that the pressing temperature was set to 169° C. When the cross section of the sheet-like molded product was observed using a scanning electron microscope, thermal fusion between fibers was confirmed in some of the fibers.

Example 3
A sheet-like molded product (thickness: about 1 mm) was obtained in the same manner as in Example 1, except that the kneading temperature and the pressing temperature were both set to 200° C. When the cross section of the sheet-like molded product was observed using a scanning electron microscope, the fibers were found to be present independently, and no thermal fusion between the fibers was confirmed.

Example 4
A sheet-like molded product (thickness: about 1 mm) was obtained in the same manner as in Example 1, except that 40 g of pulverized material A (80 parts by mass) and polypropylene fiber B (20 parts by mass) were kneaded together.

Example 5
A sheet-like molded product (thickness: approximately 1 mm) was obtained in the same manner as in Example 3, except that a mixture of 45 g of pulverized material A (90 parts by mass) and nylon fiber C (10 parts by mass) was used as the raw material. When the cross section of the sheet-like molded product was observed using a scanning electron microscope, the fibers were found to be present alone, and no thermal fusion between the fibers was confirmed.

Example 6
A sheet-like molded body (thickness: approximately 1 mm) was obtained in the same manner as in Example 3, except that a mixture of 40 g of pulverized material A (80 parts by mass) and nylon fiber C (20 parts by mass) was used as the raw material.

Example 7
A sheet-like molded product (thickness: approximately 1 mm) was obtained in the same manner as in Example 1, except that the fibers (polypropylene fiber B and nylon fiber C) were not blended and only pulverized material A (50 g) was used as the raw material. When the cross section of the sheet-like molded product was observed using a scanning electron microscope, the fibers were found to be present alone and no thermal fusion between the fibers was confirmed.

(Example 8)
A sheet-like molded product (thickness: approximately 1 mm) was obtained in the same manner as in Example 3, except that the fibers (polypropylene fiber B and nylon fiber C) were not blended and only pulverized material A (50 g) was used as the raw material. When the cross section of the sheet-like molded product was observed using a scanning electron microscope, the fibers were present independently and no thermal fusion between the fibers was confirmed.

(Comparative Example 1)
A sheet-like molding (thickness: approximately 1 mm) was obtained in the same manner as in Example 3, except that pulverized material A and fibers (polypropylene fiber B and nylon fiber C) were not blended, and only polyvinyl chloride resin pulverized material D (50 g) was used as the raw material.

<Evaluation of Elastic Modulus>
Test specimens were prepared by punching out multiple test specimens from each of the sheet-like molded articles of the Examples and Comparative Examples. The test specimens were 120 mm long and 10 mm wide. Tensile tests were performed on the test specimens in an atmosphere of 23°C and 50% RH with a chuck distance of 50 mm and a tensile speed of 50 mm/min. Three tensile tests were performed on each Example and Comparative Example. The tensile modulus was calculated for strains between 0.0005 and 0.0025. The results are shown in Table 1.

<Observation of fiber structure in the kneaded material>
The kneaded material prepared in Example 1 was cut into pieces several millimeters square, and the polyvinyl chloride resin and plasticizer were extracted and removed using tetrahydrofuran (THF) as a solvent. The pieces were then dried to obtain samples. The fibers and calcium carbonate separated from each other, and the sample did not retain its original shape after cutting. Observation of the sample using a scanning electron microscope confirmed the presence of fibers (see Figures 3(a) and 3(b)). Thermal fusion between fibers was confirmed in some of the fibers. Elemental analysis of the fused fiber portions was performed using an energy dispersive X-ray spectrometer (EDS) attached to the scanning electron microscope, and no N derived from nylon was detected. This confirmed that the fused fibers were polypropylene fibers.

The kneaded material prepared in Example 3 was cut into pieces several millimeters square, and the polyvinyl chloride resin and plasticizer were extracted and removed using tetrahydrofuran (THF) as a solvent. The sample was then dried to obtain a sample. The fibers and calcium carbonate did not easily separate from the sample, and the sample maintained its initial shape after cutting. Observation of the sample using a scanning electron microscope confirmed the presence of fibers and clumps presumably formed by melting the fibers (see Figures 4(a) and 4(b)). No thermal fusion between the fibers was observed. Elemental analysis of the fibers and clumps using an energy dispersive X-ray spectrometer (EDS) attached to the scanning electron microscope confirmed the presence of N derived from nylon fibers in the fibers, but not in the clumps. This confirmed that the fibers were nylon and the clumps were formed by melting polypropylene fibers.

<Production of Block Molded Body>
Example 9
A block molded body was produced from the kneaded material prepared in the same manner as in Example 1. That is, the kneaded material obtained in the same manner as in Example 1 was pressed under conditions of a temperature of 157°C and a pressure of 15 MPa to obtain a disk-shaped molded body (block molded body) having a diameter of 28 mm and a thickness of 21 mm.

Example 10
A disk-shaped molded product was obtained in the same manner as in Example 9, except that a mixture of 45 g of pulverized material A (90 parts by mass) and nylon fiber C (10 parts by mass) was used as the raw material.

Example 11
A disk-shaped molded product was obtained in the same manner as in Example 9, except that the kneading temperature was 200°C and the pressing temperature was also 200°C.

Example 12
A disk-shaped molded product was obtained in the same manner as in Example 10, except that the kneading temperature was 200°C and the pressing temperature was also 200°C.

Example 13
A disk-shaped molded product was obtained in the same manner as in Example 11, except that no fibers (polypropylene fiber B and nylon fiber C) were blended and only pulverized material A (50 g) was used as the raw material.

(Comparative Example 2)
A disk-shaped molded body was obtained in the same manner as in Example 11, except that the pulverized material A and fibers (polypropylene fiber B and nylon fiber C) were not blended, and only polyvinyl chloride resin pulverized material D (50 g) was used as the raw material.

<Evaluation of Elastic Modulus>
A compression test was carried out on each of the disk-shaped molded articles according to the above Examples and Comparative Examples at a compression rate of 5 mm/min in an atmosphere of 23°C and 50% RH. The compressive modulus of elasticity was obtained in the region where the stress and strain were linearly related in the obtained stress-strain diagram. The results are shown in Table 2.

<Manufacturing of recycled abrasive bodies>
In addition to the above-mentioned pulverized material A, the following raw materials were prepared.
Calcium carbonate particles: manufactured by Hayashi Pure Chemical Industries (particle size: 2.2 μm)
Alumina particles: Naniwa Polishing Industry (No. 400)

(Examples 14A and 15A)
Kneaded materials were prepared with the compositions shown in Table 3. The kneading temperature was 200° C. Each kneaded material was pressed at a temperature of 200° C. and a pressure of 15 MPa to obtain recycled abrasive bodies (diameter 28 mm, thickness 21 mm) according to Examples 14A and 15A.

The obtained abrasive body was inserted into a 6 mm diameter drill and brought into contact with a stainless steel plate and a copper plate while rotating with an electric driver drill. A 10 mm square frame was previously drawn on each of the stainless steel plate and the copper plate with a pen, and the time required for polishing the area within the frame was measured. The time when the gloss of the area within the frame disappeared was defined as the end point. The polishing performance was evaluated based on the following criteria. As a result, the polishing performance shown in Table 3 was confirmed for the stainless steel plate and the copper plate.
A: Polishing was completed in a short time (1 to 20 seconds).
B: Polishing took longer than A (21 to 60 seconds).
C: Polishing took longer than B (61 to 90 seconds).
D: Almost no polishing was possible (polishing was not possible even after 91 seconds or more).

As described below, recycled abrasive bodies with a diameter of 10 mm and a thickness of 20 mm were prepared, and their polishing performance was evaluated. The obtained abrasive bodies were inserted into a 3.5 mm diameter drill and brought into contact with a stainless steel plate and a copper plate while rotating with an electric driver drill. A 10 mm square frame was previously drawn on each of the stainless steel plate and the copper plate with a pen, and the time required to polish the area within the frame was measured. The time when the gloss of the area within the frame disappeared was defined as the end point. The polishing performance was evaluated based on the following criteria. As a result, the polishing performance shown in Tables 4 and 5 was confirmed for the stainless steel plate and the copper plate.
A: Polishing was completed in a short time (1 to 20 seconds).
B: Polishing took longer than A (21 to 60 seconds).
C: Polishing took longer than B (61 to 90 seconds).
D: Almost no polishing was possible (polishing was not possible even after 91 seconds or more).

The "surface hardness" shown in Tables 4 and 5 was measured using a durometer hardness tester (type D) in accordance with JIS K 7215. For each example and comparative example, the test was carried out three times, and the surface hardness was calculated from the average value.
The "moldability" shown in Tables 4 and 5 was evaluated based on the following criteria.
A: Can be molded with a good appearance. B: Can be molded, but moldability is inferior to A. C: Cannot be molded. The results are shown in Tables 4 and 5.

Example 14B
A recycled abrasive body was obtained in the same manner as in Example 14A, except that the recycled abrasive body was 10 mm in diameter and 20 mm in thickness instead of 28 mm in diameter and 21 mm in thickness.

(Example 15B)
A recycled abrasive body was obtained in the same manner as in Example 15A, except that the recycled abrasive body was 10 mm in diameter and 20 mm in thickness instead of 28 mm in diameter and 21 mm in thickness.

(Comparative Example 3)
Polyvinyl chloride resin pulverized material D (100 parts by mass) was kneaded at a temperature of 200°C. As in Example 1, a batch kneader having two blades was used for kneading, with one blade rotating at 60 rpm and the other at 90 rpm. The kneading time was 5 minutes. The kneaded material was pressed at a temperature of 200°C and a pressure of 15 MPa to obtain a cycle abrasive body (diameter 10 mm, thickness 20 mm).

Example 16
A mixture of pulverized material A (67 parts by mass) and nylon fiber C (33 parts by mass) was kneaded at a temperature of 200°C. As in Example 1, a batch kneader having two blades was used for kneading, with one blade rotating at 60 rpm and the other at 90 rpm. The kneading time was 5 minutes. The kneaded mixture was pressed at a temperature of 200°C and a pressure of 15 MPa to obtain a cycle-polished body (diameter 10 mm, thickness 20 mm).

(Example 17)
A mixture of 70 parts by mass of pulverized polyvinyl chloride resin D and 30 parts by mass of alumina particles was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded product was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 18)
A mixture of pulverized material A (47 parts by mass), nylon fiber C (23 parts by mass), and alumina particles (30 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

Example 19
A mixture of pulverized material A (28 parts by mass), nylon fiber C (42 parts by mass), and alumina particles (30 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 20)
A mixture of pulverized material A (9 parts by mass), nylon fiber C (61 parts by mass), and alumina particles (30 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 21)
A mixture of pulverized material A (50 parts by mass) and alumina particles (50 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded product was pressed at a temperature of 200° C. and a pressure of 15 MPa.

Example 22
A mixture of pulverized polyvinyl chloride resin D (90 parts by mass) and alumina particles (10 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 23)
A mixture of pulverized material A (90 parts by mass) and alumina particles (10 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded product was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 24)
A mixture of pulverized material A (60 parts by mass), nylon fiber C (30 parts by mass), and alumina particles (10 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

Example 25
A mixture of pulverized polyvinyl chloride resin D (95 parts by mass) and alumina particles (5 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded product was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 26)
A mixture of pulverized material A (95 parts by mass) and alumina particles (5 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded product was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 27)
A mixture of pulverized material A (63 parts by mass), nylon fiber C (32 parts by mass), and alumina particles (5 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 28)
A mixture of pulverized material A (47 parts by mass), nylon fiber C (23 parts by mass), and calcium carbonate particles (30 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 29)
A mixture of pulverized material A (70 parts by mass) and alumina particles (30 parts by mass) was kneaded at a temperature of 141° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded product was pressed at a temperature of 157° C. and a pressure of 15 MPa.

(Example 30)
A mixture of pulverized material A (70 parts by mass) and alumina particles (30 parts by mass) was kneaded at a temperature of 141° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 169° C. and a pressure of 15 MPa.

(Example 31)
A mixture of pulverized material A (40 parts by mass), calcium carbonate (30 parts by mass), and alumina particles (30 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 32)
A mixture of pulverized polyvinyl chloride resin D (52 parts by mass), nylon fiber E (18 parts by mass), and alumina particles (30 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 33)
A mixture of pulverized polyvinyl chloride resin D (35 parts by mass), nylon fiber E (35 parts by mass), and alumina particles (30 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 34)
A mixture of pulverized polyvinyl chloride resin D (52 parts by mass), nylon fiber C (18 parts by mass), and alumina particles (30 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 35)
A mixture of 35 parts by mass of pulverized polyvinyl chloride resin D, 35 parts by mass of nylon fiber C, and 30 parts by mass of alumina particles was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 36)
A mixture of 25 parts by mass of pulverized polyvinyl chloride resin F, 25 parts by mass of nylon fiber C, and 50 parts by mass of alumina particles was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded mixture was pressed at a temperature of 200° C. and a pressure of 15 MPa.

(Example 37)
A mixture of polyvinyl chloride resin G (25 parts by mass), nylon fiber C (25 parts by mass), and alumina particles (50 parts by mass) was kneaded at a temperature of 200° C. A recycled abrasive body (diameter 10 mm, thickness 20 mm) was obtained in the same manner as in Example 16, except that the resulting kneaded product was pressed at a temperature of 200° C. and a pressure of 15 MPa.

1...pile layer, 3...base layer, 3a...intermediate layer, 3b...base layer, 5...matrix resin, 7...polypropylene fiber (fiber), 10...tile carpet, 20...sheet-shaped molded body

Claims (17)

(A) kneading a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer with fibers at a temperature of 141 to 169 °C to obtain a kneaded mixture;
(B) processing the kneaded mixture into a molded body;
Including,
the fibers comprise polypropylene fibers;
The method for producing a molded body , wherein the polypropylene fibers in the molded body have intertwining points where the polypropylene fibers are thermally fused together . The method for producing a molded article according to claim 1, wherein the fibers further comprise at least one fiber selected from the group consisting of nylon 6 fibers and nylon 66 fibers . The method for producing a molded article according to claim 1 or 2 , wherein at least a part of the polypropylene fibers before kneading in step (A) has a length of 2 mm or more. (A) Before the step,
(a1) crushing a carpet having a pile layer made of pile yarns and a base layer in which some of the pile yarns are embedded and which contains at least a polyvinyl chloride resin and a plasticizer;
The method for producing a molded article according to any one of claims 1 to 3 , wherein at least a part of the matrix resin composition in step (A) is crushed material of the carpet. The method for producing a molded article according to claim 4 , wherein the carpet is a tile carpet. The method for producing a molded article according to claim 5 , wherein the tile carpet is a discarded tile carpet. the pile yarns comprise polypropylene fibers ;
The method for producing a molded article according to any one of claims 4 to 6 , wherein at least a part of the polypropylene fibers in step (A) are crushed pile yarns. The method for producing a molded article according to any one of claims 4 to 7, wherein the pile yarn further comprises at least one fiber selected from the group consisting of nylon 6 fiber and nylon 66 fiber. a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer;
Fiber and
A molded body comprising:
the fibers comprise polypropylene fibers;
The polypropylene fibers in the molded body have intertwining points where the polypropylene fibers are thermally fused together . The molded article according to claim 9, having a tensile modulus of elasticity of 21 MPa or more. The molded article according to claim 9 or 10, having a compressive modulus of elasticity of 8 MPa or more. a step of kneading a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer , fibers , and an abrasive at a temperature of 141 to 169 °C to obtain a kneaded mixture;
forming the kneaded material into an abrasive body;
Including,
the fibers comprise polypropylene fibers;
The method for manufacturing an abrasive body , wherein the polypropylene fibers in the abrasive body have intertwining points where the polypropylene fibers are thermally fused together . a step of kneading a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer with fibers at a temperature of 141 to 169 °C to obtain a kneaded mixture;
forming the kneaded material into an abrasive body;
Including,
the content of the fibers in the kneaded material is 10 to 80 mass% based on the mass of the kneaded material,
the fibers comprise polypropylene fibers;
The method for manufacturing an abrasive body , wherein the polypropylene fibers in the abrasive body have intertwining points where the polypropylene fibers are thermally fused together . a step of kneading a matrix resin composition containing at least a polyvinyl chloride resin , fibers , and an abrasive under a temperature condition of 141 to 169 °C to obtain a kneaded product;
forming the kneaded material into an abrasive body;
Including,
the fibers comprise polypropylene fibers;
The method for manufacturing an abrasive body , wherein the polypropylene fibers in the abrasive body have intertwining points where the polypropylene fibers are thermally fused together . a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer;
Fiber and
Abrasives and
1. An abrasive body comprising:
the fibers comprise polypropylene fibers;
The polypropylene fibers in the polishing body have intertwining points where the polypropylene fibers are thermally fused together . a matrix resin composition containing at least a polyvinyl chloride resin and a plasticizer;
Fiber and
1. An abrasive body comprising:
The content of the fibers is 10 to 80% by mass,
the fibers comprise polypropylene fibers;
The polypropylene fibers in the polishing body have intertwining points where the polypropylene fibers are thermally fused together . a matrix resin composition containing at least a polyvinyl chloride resin;
Fiber and
Abrasives and
1. An abrasive body comprising:
the fibers comprise polypropylene fibers;
The polypropylene fibers in the polishing body have intertwining points where the polypropylene fibers are thermally fused together .