JP2002018727A - Polishing complex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing complex excellent in polishing performance, easily disposed of after use without applying load to global environment, and excellent in polishing efficiency with little electrostatic charge. SOLUTION: In this polishing complex containing matrix resin and abrasive, the matrix resin is biodegradable resin and is provided with the following material properties; a fusing point is 60-190 deg.C, the number average molecular weight is 5000 or more, and the half-life of charging voltage in electrostatic chargeability is 180 sec or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing composite, and more particularly, to a polishing composite which has good polishing performance, is easy to dispose after use, does not impose a load on the global environment, and further has a chargeable property. The present invention relates to a polishing composite which has low polishing efficiency and excellent polishing efficiency. The polishing composite of the present invention is mainly used for precision machine parts, brushes for electronic and electric parts,
Useful for blasting and barrel polishing.

[0002]

2. Description of the Related Art A conventional polishing composite (hereinafter sometimes referred to as a medium) is composed of a matrix of a non-biodegradable resin such as polyolefin, polyamide, polyimide, phenolic resin, unsaturated polyester, etc. Is manufactured by melt-kneading or mixing the liquid resin and the abrasive and then curing. Separately, a powdered resin matrix and an abrasive are dry-blended, then heat-molded in a mold, and pelletized into a desired size and shape. Normally, these media wear themselves as they are used, and the media to be polished (hereinafter, referred to as
When it reaches the size of the hole or pocket of the work (called a work) and becomes clogged, it has a life and is discarded together with wear powder.

[0003]

However, in the conventional media, there is a problem in the abrasion powder of the media itself generated at the time of use and the disposal process after the wear is reduced and the media becomes unusable. That is, even if the incinerator is burned, there is a problem that the burned calorie is high and the incinerator is damaged, and the combustion gas such as toxic hydrogen halide and dioxin is released to cause environmental pollution. In addition, even when landfilled in soil, the matrix resin of the media is chemically and physically stable and does not disappear, causing a finite landfill saturation and a non-renewable load on the environment. There is a risk of giving. On the other hand, a method of recycling the matrix resin is also conceivable, but it is extremely difficult to separate and extract the composite resin component from the medium and to regenerate it. Further, the conventional media has a problem that abrasion powder easily adheres to a work due to static electricity generated during use, and polishing efficiency is reduced. For example, when a conventional medium is used for deburring an electronic / electric part, particularly an IC chip, the internal circuit of the part may be destroyed by static electricity generated from the medium.

Accordingly, it is an object of the present invention to provide a medium which has good polishing performance, is easy to dispose after use, does not impose a load on the global environment, and has a low electrification and excellent polishing efficiency. It is in.

[0005]

According to the present invention, in a polishing composite comprising a matrix resin and an abrasive, the matrix resin is a biodegradable resin and has the following physical properties. A polishing composite is provided. Physical properties: The melting point is 60 to 190 ° C., the number average molecular weight is 5,000 or more, and the half life of the charging voltage in chargeability is 180 seconds or less. Further, the present invention provides the above-described polishing composite, wherein the mixing ratio of the biodegradable resin and the abrasive is 15 to 85% by weight of the biodegradable resin and 85 to 15% by weight of the abrasive. .
Further, the present invention provides the above polishing composite, wherein the biodegradable resin is a biodegradable aliphatic polyester.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be further described.
As the biodegradable resin as the matrix resin used in the present invention, all known biodegradable resins can be applied, but the following physical properties are required. Physical properties: The melting point is 60 to 190 ° C., the number average molecular weight is 5,000 or more, and the half life of the charging voltage in chargeability is 180 seconds or less. When the melting point is lower than 60 ° C., for example, in the case of barrel polishing, the physical properties of the medium are reduced due to frictional heat in the barrel, and sufficient polishing performance is not exhibited. Conversely, the melting point is 190
If the temperature exceeds ℃, the temperature at the time of kneading the abrasive with the biodegradable resin will increase, leading to heating deterioration of the biodegradable resin,
The melt viscosity is so high that the abrasive cannot be sufficiently mixed, and the performance as a medium cannot be satisfied. If the number average molecular weight is less than 5,000, sufficient strength as a matrix resin cannot be obtained, causing a practical problem. Further, if the half-life of the charging voltage exceeds 180 seconds, problems such as easy attachment of abrasion powder to the work occur, and the polishing efficiency is reduced.

[0007] The half-life of the charging voltage in the present invention means a value measured by the following method. Measuring machine: Neostometer (TYPE S manufactured by Shishido Shokai Co., Ltd.)
-5109) Test piece: Press molded product 40 × 50mm, thickness 2m
m Measurement method: Adjust the Neostometer to an applied voltage of 10 kV and a receiver height of 15 mm. Voltage (10 kV)
Take the minutes and read the time in seconds until the charged voltage has decayed to 50%. This read time is called a half-life.

The term "biodegradable resin" as used in the present invention means that it is stable in the air and hardly changes, and is used in an environment where microorganisms (bacteria, molds, etc.) are present, for example, in soil, fresh water, and sea water. , Microorganisms are involved in compost,
It means resin that is decomposed into water, carbon dioxide and biomass.

The following are examples of the biodegradable resin that can be used in the present invention. Glycols and polybasic acids (or acid anhydrides) as main components, or small amounts of trihydric or higher polyhydric alcohols, polyhydric oxycarboxylic acids (or acid anhydrides),
Or a polyester [A] synthesized by a polycondensation reaction in the presence or absence of a trivalent or higher polycarboxylic acid (or an acid anhydride thereof), a ring-opening polymerization reaction between a cyclic ether and a polybasic acid anhydride [B], polyester (polylactic acid) [C] synthesized by condensation polymerization of lactic acid or ring-opening polymerization of lactic acid dimer, and polyester [D] synthesized by ring-opening polymerization of lactone ].

[0010] The following biodegradable resins can also be used in the present invention. The polyester [A], [B],
[C], to the hydroxyl group or carboxyl group of the terminal group of [D],
A biodegradable polyester containing a urethane bond or an amide bond in the main chain, having a molecular weight increased by bonding a crosslinking agent having a reactive group capable of bonding thereto (for example, diisocyanate, diamine, diepoxide, etc.). A crosslinking agent (for example, diisocyanate, diamine, diepoxide, etc.) having a reactive group capable of binding to a hydroxyl group or a carboxyl group at the terminal group of the polyester [A], [B], [C], [D]. Combined, polyester [A], [B],
(C), a plurality of types (D) were graft copolymerized with each other,
Biodegradable polyester containing a urethane bond or amide bond in the main chain. The polyester [A], [B], [C],
A biodegradable polyester resin obtained by copolymerizing [D] with an aromatic component.

In addition to the above, polyester carbonate, cellulose acetate or a polyester copolymer thereof, polyester amide, polyhydroxyalkanoate and the like can also be used in the present invention. Further, a resin in which physical properties are modified by blending plural kinds of the above-mentioned biodegradable resins can also be used.

Among these, preferred biodegradable resins include polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polycaprolactone, polyesteramide, polyestercarbonate, cellulose acetate, and polyhydroxyalkanoate as a chemically synthesized system. Microbial production systems such as aromatic polyester copolymers and the like include polyhydroxybutyrate and polyhydroxybutyrate valerate.

In particular, when an aliphatic (including cycloaliphatic) polyester is used as the biodegradable resin, a medium having more excellent electric resistance can be provided. In Table 1 below,
Polybutylene succinate (PBS) (manufactured by Showa Polymer Co., Ltd., trade name: Bionole) as an aliphatic polyester
# 1001) and polybutylene succinate adipate (PSA) (Showa Kogaku Co., Ltd., trade name: Bionole 3030), as well as the chargeability data of polypropylene (PP) and polystyrene (HIPS) for comparison.

[0014]

[Table 1]

As the abrasive used in the present invention, any general abrasive which does not cause an environmental burden even when discarded can be used. For example, materials having high hardness such as silicon carbide powder, alumina powder, and silicon oxide, materials having low hardness such as plant shells and animal bones, and diamond powder, which is rare, can be used. The particle size of these abrasives is not particularly limited, and the size is appropriately selected according to the size of the medium, the molding method, and the polishing conditions of the work.

When kneading a biodegradable resin as a matrix resin and an abrasive, it is necessary to pay close attention to the water content of each raw material. In particular, it is necessary to open the bag once containing the raw material and then re-dry it when using a bag left for a certain time. For example, the water content is preferably adjusted to 0.1% by weight or less with a biodegradable resin and 0.3% by weight or less with an abrasive before use. When a biodegradable resin or an abrasive having a high water content is used, hydrolysis of the biodegradable resin occurs during kneading, which may adversely affect the performance as a medium.

The mixing ratio of the biodegradable resin as the matrix resin and the abrasive is different depending on the application. For example, 85 to 15% by weight of the biodegradable resin and 15 to 85% by weight of the abrasive
It is. In addition, when kneading the biodegradable resin and the abrasive, an antioxidant that suppresses thermal decomposition of the resin, a lubricant to facilitate molding, and a silane coupling agent that improves interfacial adhesion between the resin and the abrasive. , Other, yellowing inhibitors, dyes, pigments,
A small amount of an additive such as an antistatic agent may be appropriately added. When these additives are added to the resin in advance, it is not necessary to add them again.

An extruder with a powder feeder or a kneader is effective as a means for kneading the abrasive with the biodegradable resin. The former is used as a continuous process, and the latter is used as a batch process. As for the screw of the extruder, the twin screw type is more excellent, but the abrasive is severely worn. Therefore, in this case, it is desirable to use a single screw type screw. It should be noted that there is no problem in the performance as a medium even in a kneading state using a single screw. The former and the latter have advantages and disadvantages, respectively. The former is efficient in continuous operation, but has a large maintenance load due to severe wear of the screw in the region where the abrasive is not sufficiently dispersed in the resin. On the other hand, in the latter, since the abrasive is sufficiently dispersed in the resin in the kneader and then applied to the screw, the abrasion is small, but the production efficiency is reduced due to the batch system.

Manufacturing by an extruder with a powder feeder is performed by the following process. The biodegradable resin is poured into the extruder at a constant speed from the pellet feeder. A powder feeder is mounted at a point where the resin is caught in the screw and melts while moving downstream in the piston flow, from which an abrasive is fed at a speed according to the compounding ratio. The supplied abrasive is kneaded and dispersed in the molten biodegradable resin while moving with a screw, and extruded into a strand shape from a die nozzle. This is drawn into a water tank, cooled and solidified, and then applied to a strand cutter to finish into pellets.

Next, a manufacturing process using a kneader-ruder is performed as follows. The measured biodegradable resin is put into the kneader and melted while stirring. A measured amount of the abrasive is added thereto and kneaded for a specified time. Next, the screw of the ruder is started, and the kneaded material is sent to the die nozzle and extruded from the die nozzle into a strand. This is drawn into a water tank, cooled and solidified, and then subjected to a strand cutter to finish into pellets.

In addition, as a special method of forming a medium by mixing a biodegradable resin and an abrasive, a dry blend of the abrasive with the powdered biodegradable resin is performed, and then the composite is filled into a mold. After melting and solidifying by high-frequency heating or the like, there is a method of taking out from a mold and molding media of various shapes. This method is useful for forming porous media-dispersed micropores in a medium, and for obtaining a medium rich in abrasives and rich in surface abrasives.

The media to be pelletized can be finished in various sizes and shapes by changing the shape and shape of the die nozzle according to the grade. These diversified media are appropriately selected in grade according to the size and shape of the work to be polished and used under optimum conditions. Media size is 1-6 depending on the purpose used
Finished in a wide range of 0 mm, the shapes are various such as cylinder, oblique cylinder, triangular prism, square prism, rhombus, regular tetrahedron. In addition, by using an underwater cut type pelletizer, it can be finished in a spherical shape or a stone-like shape, and the kneaded material can be taken out with a block of a certain size and then crushed into a random granule.

The media finished in various sizes and shapes as described above is reduced to a moisture content of 0.3% by weight or less through a drying step, and is packaged in a moisture-impermeable paper bag made of kraft paper laminated with aluminum foil. Will be shipped.

The media has a wide range of applications, for example for brush, blast or barrel polishing, and is mainly used for surface finishing of precision instruments, electronic and electrical parts. As an example, in a barrel-type polishing machine, a work called a barrel is filled with a work and media together, and the surface of the work is polished by applying rotation and vibration to it for a certain period of time to obtain a surface state that meets the work specifications. Finished. At this time, abrasion powder of the media itself is generated in the barrel while being mixed with the polishing dust of the work. The media can be used multiple times, but eventually wears itself and wears out to a size that fills holes or pockets in the workpiece and reaches its end of life. Abrasive dust and abrasion powder and used media generated in this way are not problematic in disposal treatment such as landfilling as long as the metal component of the abrasive dust and the abrasive component prepared in the media are naturally present, In conventional media, since the matrix resin is chemically and physically stable, discarding the media causes an environmental burden by causing disposal, thereby causing pollution. However, according to the present invention, this problem is avoided because the matrix resin is a biodegradable resin.

As a method of disposing of these abrasion powders and used media, landfilling and composting are effective. Degradation speed of the media varies depending on the biodegradable resin used, but it completely decomposes in 3 to 2 years for landfill and about 1 month for compost treatment and changes to water, carbon dioxide and mineral components, etc. And returned to the environment. Also, even if it is inevitably incinerated, no toxic gas such as dioxin is generated, and the calorie burned is about half of that of a general olefin resin, and there is no fear that the combustion furnace will be rapidly damaged. Thus, the media provided by the present invention is positioned as an environmentally conscious media that does not burden the environment.

[0026]

The present invention will be further described below with reference to examples and comparative examples. The present invention is not limited by the following examples.

The media of the examples and comparative examples were prepared and evaluated in the following manner. (1) Equipment used Centrifugal barrel type polishing tester (centrifugal barrel 1 liter x 4 pots, 315 rpm, trade name TAB-14 manufactured by Toho Steel Machine Co., Ltd.) (2) Procedure A. The barrel is filled with media equivalent to 600 cc. B. Test piece SUS304 50 × 20 × 1.2
mm is polished. Test piece weight measurement (cutting amount) in one hour. The test piece weight was measured for a total of two hours for one hour. Dust the media. C. After the test, the weight of the media is measured to determine the amount of wear. D. The surface roughness of the SUS test piece is measured.

The biodegradability of the media was evaluated as follows. A. Production of a flat plate test piece by pressing A 150-200 x 1-mm mold heated to 160-230 ° C according to the melting point of the matrix resin is filled with a 75-80 g medium sample, and a 1-mm-thick flat plate is formed by pressure molding. Is molded. A test piece is obtained by cutting this flat plate into a size of 30 × 60 mm. B. Adjustment of the test compost matrix Using the primary fermentation compost obtained by the garbage disposal test of the Japan Steel Works composting model facility,
The compost matrix for the biodegradability test was prepared as follows. -100 kg of primary fermentation compost was mixed with 2 kg of sugar, and water was added to adjust the water content to 65%.・ 500 × 750 × 400mm with a net inside
Stuffed compost into a plastic basket of 40
Leave for 3 days in an environmental laboratory at ℃ for refermentation. C. Evaluation of biodegradability by test compost matrix ・ Embed test piece in re-fermented compost
After standing for one week, the change in weight and change in appearance are evaluated. In the weight change measurement, the test piece after the compost treatment was measured for the weight after vacuum drying for 2 hours at a temperature 25 ° C. lower than the melting point of the resin used.

Example 1 As a biodegradable resin, polybutylene succinate (manufactured by Showa Polymer Co., Ltd., trade name: Bionore # 1001, melting point 114 ° C., number average molecular weight 30,000) After charging 4.5 kg and kneading at 180 ° C. for 5 minutes, fine alumina A-5
5.5 kg of 0K (manufactured by Showa Denko KK) was added, and the mixture was further kneaded for 10 minutes. Next, the kneaded material was extruded in a strand form from a die nozzle by activating the screw of the ruder, and a medium having a cross-sectional diameter of about 2 mm and a length of 3 mm was prepared by pelletizing. The prepared product was evaluated for abrasion by a centrifugal barrel type polishing tester, formed into a 1 mm thick flat plate, and evaluated for biodegradability by a test compost matrix.

Example 2 A polylactic acid (Lacty # 5000, trade name, manufactured by Shimadzu Corp., melting point 1) was added to a kneader-ruder (manufactured by Kasamatsu Chemical Industries, Ltd.).
75 ° C, weight average molecular weight 200,000, half life of charging voltage 60
Second) 4.5 kg was added and kneaded at 200 ° C. for 5 minutes, and then fine alumina A-50K (manufactured by Showa Denko KK) 5.5 k
g was added and kneaded for another 10 minutes. Next, the kneaded material was extruded in a strand form from a die nozzle by activating the screw of the ruder, and a medium having a cross-sectional diameter of about 2 mm and a length of 3 mm was prepared by pelletizing. This preparation was evaluated in the same manner as in Example 1.

Example 3 A polyhydroxybutyrate valerate PHBV (manufactured by Monsanto Co., Ltd.)
Product name Biopol G4112D, melting point 144 ° C, weight average molecular weight 400,000, half-life of charging voltage 70 seconds) 4.5k
g, and kneaded at 200 ° C. for 5 minutes.
5.5 kg of -50K (manufactured by Showa Denko KK) was charged, and the mixture was further kneaded for 10 minutes. Next, start the screw of the ruder and extrude the kneaded material into a strand from the die nozzle,
A medium having a cross-sectional diameter of about 2 mm and a length of 3 mm was prepared by pelletizing. This preparation was evaluated in the same manner as in Example 1.

Example 4 4.5 kg of Bionole # 1001 was charged into a kneader ruder (manufactured by Kasamatsu Chemical Industries, Ltd.), kneaded at 180 ° C. for 5 minutes, and then a silicon carbide abrasive GC # 4000 (manufactured by Showa Denko KK) ) 5.5 kg was added and kneaded for another 10 minutes.
Next, the kneaded material was extruded in a strand form from a die nozzle by activating the screw of the ruder, and a medium having a cross-sectional diameter of about 2 mm and a length of 3 mm was prepared by pelletizing. This preparation was evaluated in the same manner as in Example 1.

Example 5 Using a biaxial extruder tester equipped with a powder feeder (PCM30-25, manufactured by Ikegai Iron Works Co., Ltd.), 45% by weight of biodegradable resin Bionole # 1001 and fine alumina A-50K ( 55% by weight of Showa Denko KK
And a medium having a cross-sectional diameter of about 2 mm and a length of 3 mm was prepared by kneading, extrusion and pelletizing. This preparation was evaluated in the same manner as in Example 1.

Comparative Example 1 45% by weight of 6 nylon 1022 (manufactured by Ube Industries, Ltd.) and fine-grained alumina A were measured using a twin-screw extruder tester equipped with a powder feeder (trade name: PCM30-25, manufactured by Ikegai Iron Works) -50K (Showa Denko KK) 55
% By weight, and kneaded, extruded, and pelletized to prepare a medium having a sectional diameter of about 2 mm and a length of 3 mm. This preparation was evaluated in the same manner as in Example 1.

Comparative Example 2 Using a biaxial extruder tester equipped with a powder feeder (trade name: PCM30-25, manufactured by Ikegai Ironworks Co., Ltd.), 45% by weight of 6 nylon 1022 (manufactured by Ube Industries, Ltd.) and silicon carbide Abrasive GC # 4000 (manufactured by Showa Denko KK) was blended in a ratio of 55% by weight, and a medium having a cross-sectional diameter of about 2 mm and a length of 3 mm was prepared by kneading, extrusion and pelletizing. This preparation was evaluated in the same manner as in Example 1.

Table 2 shows the results obtained in the above Examples and Comparative Examples.

[0037]

[Table 2]

According to Table 2, the polishing performance of the media of the present invention is not inferior to that of the conventional non-biodegradable nylon media and shows excellent biodegradability. In all of Examples 1 to 5, the decomposition in the compost is fast, and depending on the type used, it has already been confirmed that it is completely decomposed in the ground in six months to two years. Further, it was confirmed that the media of the present invention had extremely low electrification at the time of use as compared with the conventional media, so that abrasion powder was not attached to the work and the polishing efficiency was excellent.

[0039]

According to the present invention, a polishing composite which has good polishing performance, is easy to dispose after use, does not impose a load on the global environment, and has low charging and excellent polishing efficiency. Is provided. The polishing composite of the present invention is useful mainly for polishing brushes, blasts, and barrels of precision mechanical parts, electronic and electric parts, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 101/16 ZAB C08L 101/16 ZAB C09K 3/14 550 C09K 3/14 550J 560 560 (72) Inventor Yoshio Okino 2-315-6 Nishi-Sayamagaoka, Tokorozawa-shi, Saitama F-term (reference) AF52 AH19 DA09 DA13 DA18 DA22 4J002 AB021 AH002 CF031 CF101 CF131 CF181 CG041 CL081 DA016 DE146 DJ016 FD202 GT00

Claims (3)

[Claims] 1. A polishing composite comprising a matrix resin and an abrasive, wherein the matrix resin is a biodegradable resin and has the following physical properties. Physical properties: The melting point is 60 to 190 ° C., the number average molecular weight is 5,000 or more, and the half life of the charging voltage in chargeability is 180 seconds or less. 2. The mixing ratio of the biodegradable resin and the abrasive is 15 to 85% by weight of the biodegradable resin and the abrasive 8
The polishing composite according to claim 1, wherein the amount is 5 to 15% by weight. 3. The polishing composite according to claim 1, wherein the biodegradable resin is a biodegradable aliphatic polyester.