JP6906763B2 - Carbon Nanotube Composite Resin Bond Whetstone - Google Patents

Description

The present invention relates to, for example, a resin bond grindstone used for performing abrasive grain processing on a workpiece made of a difficult-to-cut material (heat-resistant alloy, cemented carbide, tool steel, ceramics, glass, etc.).

(Resin bond whetstone)
Generally, in a resin bond grindstone such as a grinding wheel, a polishing grindstone, and a fixed abrasive grain wire saw, an abrasive grain layer formed by bonding a large number of abrasive grains with a resin bond material on the processed surface side (surface side) of the grindstone body. Is formed.

(Request for resin bond grindstone)
Not limited to resin bond grindstones, grindstones are required to further improve abrasive grain processing performance such as tool life and grinding ratio as products. In order to meet this demand, it is necessary to increase the abrasive grain holding force (in other words, the abrasive grain holding force of the bond material) in the abrasive grain layer to prevent the abrasive grains from falling off.

(Countermeasures by conventional technology)
Therefore, a reinforcing filler or the like is mixed with the bond material to increase the mechanical strength of the bond material (see Patent Document 1), or a metal coating is formed on the surface of the abrasive grains to form an abrasive grain and the bond material. Measures have been taken to increase the abrasive grain holding force of the abrasive grain layer by increasing the adhesion (see Patent Documents 2 to 4).

(Problems of Patent Document 1)
However, when the method of mixing the reinforcing filler into the bond material as in Patent Document 1, the mechanical strength of the bond material can be strengthened as a whole, but the abrasive grain holding force of the abrasive grain layer can be strengthened as a whole. It is not possible to selectively strengthen the mechanical strength of the bond material around the abrasive grains, which has a great influence on the above.

(Problems of Patent Documents 2 to 4)
Further, when a method of forming a metal coating on the surface of the abrasive grains is adopted as in Patent Documents 2 to 4, the adhesion between the abrasive grains and the bonding material is made an anchor effect (that is, that is) through the metal coating. , Physical holding power), but in these methods, since no chemical bond is intervened between the abrasive grains and the bond material, the abrasive grain holding power of the abrasive grain layer can be sufficiently increased. There is a problem that it is not possible to cause the abrasive grains to come off during abrasive grain processing, and it is not easy to improve the tool life and the abrasive grain processing performance of the resin bond grindstone.

(Carbon nanotube (CNT) coating)
Recently, a method of coating the surface of abrasive grains with carbon nanotubes (hereinafter, also simply referred to as “CNT”) to improve the adhesion between the abrasive grains and the bonding material has been proposed (Patent Documents). 5). When this CNT coating forming method is adopted, the anchor effect is increased as compared with the metal film forming method described above, so that the adhesion between the abrasive grains and the bond material can be further strengthened.

(Problems with conventional CNT coating)
However, in the method of Patent Document 5, the adhesion between the CNT and the bond material depends only on the physical anchor effect and no chemical bond is used. Therefore, the abrasive grain holding force of the abrasive grain layer is increased. The present inventors consider that there is still room for improvement. In a preferred embodiment of Patent Document 5, a pair of functional groups are introduced between the abrasive grains and the CNTs, and a chemical bond is interposed between the abrasive grains and the CNTs to form a pair of the abrasive grains and the CNTs. It has been found that the adhesion between them can be further improved.

Japanese Unexamined Patent Publication No. 2007-253318 Japanese Unexamined Patent Publication No. 2007-054905 Japanese Unexamined Patent Publication No. 2006-181698 Japanese Unexamined Patent Publication No. 2007-038337 Japanese Unexamined Patent Publication No. 2010-064217

The present invention has been proposed in view of such conventional circumstances. That is, an object of the present invention is to provide a resin bond grindstone in which the coating abrasive grains are suppressed from falling off and the tool life and the abrasive grain processing performance are improved.

In order to selectively strengthen the abrasive grain holding force in the abrasive grain layer, the present inventors, in order to selectively strengthen the bonding between objects in the area around the abrasive grains, (1) the bonding between the abrasive grains and the CNT, and (2). ) We divided it into the bond between CNT and the bond material, and in particular, we came up with the method of effectively strengthening the adhesion between the above-mentioned (2) objects.

Specifically, (2) by interposing a chemical bond due to the introduction of a functional group as well as an anchor effect of CNT to the bond material between the CNT and the bond material, each abrasive grain is contained in the abrasive grain layer. It was made to be held firmly.

That is, the present invention adopts at least the following configurations and features.
(Aspect 1)
With a large number of coated abrasive grains,
A resin bond material that combines the coated abrasive grains to form an abrasive grain layer,
In the resin bond grindstone equipped with
The coated abrasive grains are
Abrasive grains and
A carbon nanotube coating that wraps around the surface of the abrasive grains and is configured so that carbon nanotubes are entangled with each other.
And
The carbon nanotube has a functional group Y, the bond material has a functional group Z, and the functional group Y and the functional group Z are constituent elements at the interface between the carbon nanotube and the bond material. resin bonded grinding wheel, wherein the chemical bond is polarized standing to.
(Aspect 2)
One of the functional group Y and the functional group Z is one or more functional groups selected from the group consisting of a phenolic hydroxyl group, a hydroxyl group, a carboxyl group and an amino group, and the other is an isocyanate group, an epoxy group and an acid. The resin bond according to embodiment 1, wherein the resin bond is one or more functional groups selected from the group consisting of anhydrous functional groups, and a chemical bond between the functional group Y and the functional group Z is present. Grinding stone.
(Aspect 3)
The functional group Y and the functional group Z are one or more functional groups selected from the group consisting of a carboxyl group, a phenolic hydroxyl group, a hydroxyl group, an acid anhydride functional group, and a thiol group, and A copolymer B is interposed between the functional group Y and the functional group Z, and the functional group Y'that the copolymer B has and the functional group Y have a chemical bond and the copolymer B has. The resin bond grindstone according to aspect 1, wherein a chemical bond between the functional group Z'and the functional group Z is present.
(Aspect 4)
The resin bond grindstone according to aspect 3, wherein the copolymer B is a copolymer containing a 2-oxazoline-based monomer (a) as an essential constituent unit.
(Aspect 5)
The copolymer B is a copolymer containing a 2-oxazoline-based monomer (a) and a nitrogen-containing heterocyclic monomer (b) as constituent units, and is a copolymer.
The resin bond grindstone according to aspect 3, wherein the copolymer B contains 1 to 90 mol% of the 2-oxazoline-based monomer (a).
(Aspect 6)
The resin bond grindstone according to any one of aspects 3 to 5, wherein the functional group Y'and the functional group Z'are oxazoline groups.

(Form of chemical bond between functional groups)
Here, the functional group Y on the surface side of the carbon nanotube may be directly bonded to the functional group Z on the surface side of the bonding material by chemical interaction. Not limited to this direct chemical bond, a separate substance (for example, copolymer B described later) is introduced between the functional group Y and the functional group Z, and the functional group Y of the functional group Y and the functional group B is introduced. The functional group Y and the functional group Z may be indirectly linked by interposing a chemical bond with'and a chemical bond between the functional group Z'of the copolymer B and the functional group Z.

(Direct chemical bond)
One of the functional group Y and the functional group Z suitable for direct chemical bonding is one or more functional groups selected from the group consisting of a phenolic hydroxyl group, a hydroxyl group, a carboxyl group and an amino group, and the other. Is preferably one or more functional groups selected from the group consisting of an isocyanate group, an epoxy group and an acid anhydride functional group.

(Indirect chemical bond)
The functional group Y and the functional group Z suitable for indirect chemical bonding are one or more functional groups selected from the group consisting of a carboxyl group, a phenolic hydroxyl group, a hydroxyl group, an acid anhydride functional group, and a thiol group. Is preferable. As the copolymer B interposed between the functional group Y and the functional group Z, for example, it is preferable to use a copolymer containing a 2-oxazoline-based monomer (a) described later as an essential constituent unit.

In the resin bond grindstone of the present invention, the periphery of each abrasive grain is coated with carbon nanotubes (CNT). Since this CNT coating has a finer structure than the conventional metal coating, the contact area between the abrasive grains coated with CNT and the bond material is remarkably increased. That is, the CNT coating can enhance the physical anchoring effect on the abrasive grains as compared with the conventional metal coating.

Further, according to the present invention, since the CNT and the bonding material are bonded not only by the above-mentioned anchor effect but also by the action of chemical bonding due to the introduction of a functional group, the abrasive grain holding force of the abrasive grain layer is dramatically increased. be able to.

The microstructure of the CNT coating is also suitable for introducing more functional groups, and is advantageous for both the anchor effect and the chemical bond. Further, the resin bond material is extremely easy to introduce a functional group as compared with the metal bond material. As described above, the CNT coating around the abrasive grains and the resin bond material selected in the present invention are very convenient materials for strengthening the abrasive grain holding force from both the anchor effect and the chemical bond. I can say.

The resin bond grindstone of the present invention having the above structure and features can suppress the falling of the coated abrasive grains during the abrasive grain processing, and can greatly improve the tool life and the abrasive grain processing performance of the grindstone.

In the resin bond grindstone of the present invention, preferably, the functional group Y of the CNT coating and the functional group Z of the bond material are indirectly chemically bonded via the functional group of the copolymer B, or CNT. It is desirable that the functional group Y of the coating and the functional group Z of the bond material are directly chemically bonded. Since the CNT coating and the bonding material can be firmly adhered by such a chemical bond, there is an effect that a high abrasive grain holding force, which cannot be obtained only by the physical anchor effect, can be exhibited.

According to a preferred embodiment when the copolymer of the present invention is used, the copolymer B is made into a copolymer containing a 2-oxazolin-based monomer (a) as an essential constituent unit. Has the effect of being able to induce a chemical reaction with a functional group (for example, a carboxyl group, a phenolic hydroxyl group, a hydroxyl group, an acid anhydride functional group, or a thiol group) contained in a carbon nanotube coating or a bond material. .. In particular, since a strong chemical bond can be obtained between the functional group and the oxazoline group contained in the copolymer B, it is possible to exhibit a high abrasive grain holding power that cannot be obtained only by the physical anchor effect. effective.

It is a figure explaining the cross-sectional structure of the resin bond grindstone of this invention and its abrasive grain layer. It is a figure explaining the structure (a) of the coated abrasive grain of this invention, and the direct chemical bond (b) and indirect chemical bond (c) between CNT and a bond material in this invention. It is a figure which showed an example of the model of the direct chemical bond of this invention. It is a figure which showed an example of the model of the indirect chemical bond of this invention. It is a figure which showed the result of the grindstone wear test using the grindstone of Comparative Examples 1 and 2 and Example 1. FIG. It is a figure which showed the result of consideration and analysis of the result of the abrasion resistance test.

Hereinafter, the present invention will be described based on the embodiments shown in the drawings, but the present invention is not limited to the following specific embodiments. The same reference numerals are used for the same or corresponding members in each figure.

(Outline of resin bond grindstone)
As shown in FIG. 1A, the resin bond grindstone 1 according to the embodiment of the present invention is, for example, a workpiece (heat resistant alloy, cemented carbide, tool steel, ceramics, glass, etc.) made of a difficult-to-cut material (heat-resistant alloy, cemented carbide, tool steel, glass, etc.). It is used when performing abrasive grain processing on (not shown). The resin bond grindstone 1 is formed by attaching an abrasive grain layer 2 to be described later to a base metal 3 having a disk shape (shown), a shank shape, a wire shape, or the like. However, the resin bond grindstone 1 may be formed only by the abrasive grain layer 2 without providing the base metal 3 in response to the request for thinning.

(Structure of abrasive grain layer)
FIG. 1B shows a partial cross-sectional view of the abrasive grain layer 2 according to the embodiment of the present invention (partial cross-sectional structure broken along the line AA of FIG. 1A). The resin bond grindstone 1 includes a large number of coated abrasive grains 4 and a resin-made (for example, phenol resin) bond material 5 that combines the coated abrasive grains 4 to form an abrasive grain layer 2. Here, each coated abrasive grain 4 includes an abrasive grain 6 and a carbon nanotube (CNT) coating 7 that is coated so as to wrap the surface of the abrasive grain 6. The abrasive grains 6 are made of artificial diamond, but may be made of natural diamond, cBN, or the like.

(Carbon nanotube coating)
In the CNT coating 7, as shown in FIG. 2A, carbon nanotubes (CNTs) 8 are formed while being intertwined with each other. More specifically, the carbon nanotubes 8 are formed while being self-organized and entangled by a self-cohesive force such as a van der Waals force.

(Examination of abrasive grain retention phenomenon)
The present inventors examined in detail the holding phenomenon of the coated abrasive grains 4 in the abrasive grain layer 2, and as shown in FIGS. 3 and 4 described later, (1) the abrasive grains 6 and the CNT coating 7 (1) It is presumed that the adhesion between 7') and (2) the adhesion between the CNT coating 7 (7') and the bond material 5 (5') contribute to each other.

Here, in the prior art shown in Patent Document 5, it is preferable to introduce functional groups and directly chemically bond these functional groups in order to enhance the adhesion of the interface between the objects 6 and 7 of the above (1). It is stated that. However, since no special chemical treatment was performed at the interface between the objects 5 and 7 in (2) above, the adhesion at the interface depended only on the physical anchor effect. In addition, Patent Document 5 does not study or suggest a bond material 5 which is advantageous for chemical bonding with the CNT film 7.

On the other hand, in the present invention, not only the anchor effect AE but also the chemical interaction is generated at the interface between the objects 5 and 7 in (2) above (the chemical bond C described later is present). I did. That is, in the present invention, as shown in FIGS. 2 (b) and 2 (c), the carbon nanotube 8 (or the CNT coating 7 containing CNT 8) has a functional group Y on its surface side. The bond material 5 is characterized by having a functional group Z (which directly or indirectly chemically bonds with the above-mentioned functional group Y) on the surface side thereof.

(Direct chemical bond)
Specifically, as shown in FIG. 2B, the functional group Y and the functional group Z may be directly reacted to form a chemical bond. When a direct chemical bond C is formed between the functional group Y of the CNT coating 7 and the functional group Z of the bond material 5 without the intervention of the above-mentioned copolymer, the following preferred first to third embodiments are particularly suitable. There are three possibilities.

(Definition of terms)
The "modified resin" described later is defined as a resin 5'in which a reactive functional group (functional group Z) is introduced by replacing a part of the resin 5 with a modifying agent. Further, the "functional group Y of the CNT (coating)" is defined as a phenolic hydroxyl group, a hydroxyl group or a carboxyl group that is naturally introduced in the CNT manufacturing process. The amount of the functional group of the functional group Y of the CNT can be increased by acid treatment or the like, and the chemical bonding force can be enhanced. Further, the "modified CNT (coating)" is defined as a CNT into which a reactive functional group other than the above-mentioned functional group phenolic hydroxyl group, hydroxyl group or carboxyl group has been introduced.

1) Chemical Bonding of CNT Coating and Modified Resin Bonding Material In the first aspect, the CNT coating 7 and the modified resin bonding material 5'are directly chemically bonded. For example, when the functional group Y of the CNT coating 7 is a phenolic hydroxyl group, a hydroxyl group or a carboxyl group, the functional group Z of the modified resin bond material 5'is a functional group that chemically bonds with the functional group Y of the CNT coating 7. It is preferable that it is one or more functional groups selected from the group consisting of an isocyanate group, an epoxy group and an acid anhydride functional group.

2) Chemical Bonding of Modified CNT Coating and Resin Bonding Material In the second aspect, the modified CNT coating 7'and the resin bonding material 5 are directly chemically bonded. For example, when the resin bond material 5 is phenol (that is, the functional group Z associated therewith is a phenolic hydroxyl group), the functional group Y of the modified CNT coating 7'is a functional group that chemically bonds with this, particularly. , An isocyanate group, an epoxy group, and an acid anhydride functional group, preferably one or more functional groups selected from the group.

3) Chemical Bonding of Modified CNT Coating and Modified Resin Bonding Material In the third aspect, the modified CNT coating 7'and the modified resin bonding material 5'are directly chemically bonded. For example, when the modified resin bond material 5'is an epoxy-modified phenol (that is, the functional group Z associated therewith is an epoxy group), the functional group Y of the modified CNT coating 7'is a phenolic hydroxyl group, a hydroxyl group, or an amino group. It is preferably one or more functional groups selected from the group consisting of. The functional group Y shown in FIG. 3 is an amino group.

As shown in the above description and FIGS. 2B and 3, in the above-mentioned three preferred embodiments, the functional group Y attached to the CNT coating 7 or the modified CNT coating 7'and the resin bond material 5 or the modified resin Since the functional group Z attached to the bond material 5'can directly induce a chemical reaction, the physical anchor effect (see also the code AE and the dashed line with an arrow shown in FIGS. 2 (b) and 2 (c)). It has the effect of exhibiting a high abrasive grain holding power that cannot be obtained by itself.

(Indirect chemical bond)
On the other hand, as shown in FIGS. 2C and 4, between the functional group Y attached to the CNT coating 7 and the functional group Z attached to the bond material 5, the functional group Z having high reactivity with them. By introducing a separate substance having'and Y'(for example, copolymer B described later), the functional group Y and the functional group Z may form an indirect chemical bond C. When performing this indirect chemical bond, it is preferable to interpose the copolymer B at the interface between the objects 5 and 7 of the above (2). As a result, a chemical interaction occurs between the functional group Y'of the copolymer B and the functional group Y of the CNT8, and between the functional group Z'of the copolymer B and the functional group Z of the resin bond material 5. Can be connected more firmly. In the indirect chemical bond, the type and amount of the functional groups Y'and Z'of the copolymer B can be arbitrarily selected. Due to this highly flexible selectivity, functional groups Y'and Z'that exhibit high reactivity can be adopted, or the copolymer B can be selected as the optimum one according to the type and composition of the resin bond material 5. As a result, the functional groups Y', Z'of the copolymer B and the functional groups X, Y, Z of the diamond abrasive grains 6, the CNT coating 7, or the bond material 5 are combined with each other as compared with the case of the direct chemical bond. It is possible to form more bond points between them (the functional group X attached to the abrasive grains 6 will be described later).

Here, it is preferable that the copolymer B is a copolymer containing the 2-oxazoline-based monomer (a) as an essential constituent unit. As a result, an oxazoline group can be adopted as the functional group of the copolymer B, and a strong chemical bond C can be obtained. The molecular weight of the copolymer B is 5000 to 10000.

For the same reason, the copolymer B is a copolymer containing a 2-oxazoline-based monomer (a) and a nitrogen-containing heterocyclic monomer (b) as constituent units, and the 2-oxazoline-based monomer (b) is contained. The monomer (a) is preferably contained in an amount of 1 to 90 mol%. If it is less than 1 mol%, it becomes virtually impossible to cause a chemical reaction. On the other hand, when it exceeds 90 mol%, it becomes difficult to disperse the monomer (a) in a liquid such as water, and the copolymer B can be distributed to every corner of the fine structure of the CNT film 7. I can't do it.

Further, the functional group Y and the functional group Z are preferably one or more functional groups selected from the group consisting of a carboxyl group, a phenolic hydroxyl group, an acid anhydride functional group, and a thiol group. In the example shown in FIG. 4, the functional group Y is a carboxyl group and the functional group Z is a phenolic hydroxyl group, and these are the functional groups Y'and Z'of the copolymer B, respectively (example of FIG. 4). Then, both of them are strongly connected to each other by forming a chemical bond (amide ester bond in FIG. 4) with the oxazoline group).

(Modified example of copolymer B)
The copolymer B is not limited to the above-mentioned examples, and for example, a (meth) acrylate-based monomer may be selected. It is desirable that the copolymer B has a vinylpyrrolidone group in addition to (or instead of) the above-mentioned oxadrin group as the functional groups Y'and Z'accompanying the copolymer B.

(Giving a chemical bond between the abrasive grains 6 and the CNT coating 7)
In the present invention, of the above-mentioned (1) adhesion between the abrasive grains 6 and the CNT coating 7, and (2) adhesion between the CNT coating 7 and the bonding material 5, (2) adhesion The main purpose is to improve sexuality. However, in addition to the measure (2), a chemical bond described later may be applied between the abrasive grains 6 and the CNT coating 7 in order to improve the adhesion of (1).

Specifically, as shown in FIG. 3, it is preferable that the abrasive grains 6 have a functional group X on the surface side that directly chemically bonds with the functional group Y on the CNT-coated 7 side. Further, as shown in FIG. 4, the abrasive grains 6 indirectly form a chemical bond on the surface side via the functional group Y on the CNT-coated 7 side and the functional groups X'and Y'of the copolymer B. It preferably has a group X. It is expected that the abrasive grain holding power in the abrasive grain layer 2 will be further improved by the synergistic chemical bond between the different substances 5, 6 and 7. More preferably, the functional group X on the abrasive grain 6 side is selected to be the same as the functional group Y. Further, a functional group in which the functional groups X', Y'and Z'accompanied to the copolymer B have the same type (composition) may be selected. As a result, the types of functional groups to be prepared in the production of the present invention do not increase, so that the resin bond grindstone 1 in this preferred embodiment can be easily produced.

(Manufacturing method of resin bond grindstone)
Next, an example of the method for manufacturing the resin bond grindstone 1 of the present invention will also be described.

(1. Mixing process of bond material and coated abrasive grains)
The phenol resin powder and the CNT-coated abrasive grains are mixed. In addition, not only powdery phenol resin but also liquid phenol resin may be used. In this mixing step, a rotation / revolution mixer utilizing agitation, shearing, and frictional action, a cutter mill, and the like are used. A metal filler such as copper or a filler such as an inorganic compound such as SiC may be mixed for the purpose of improving the wear resistance and heat dissipation of the phenol resin or the like. Further, as the mixing method, either a dry method or a wet method may be adopted. Alternatively, the resin may be dissolved in a solvent and then mixed. In this case, a separate drying step is required at room temperature or in a heated environment.

(Mixing ratio of each raw material)
For example, each raw material is mixed at the following ratio.
CNT-coated abrasive grains; 3 to 50% (vol)
Phenol resin, etc .; 15-97% (vol)
Filler; 0-80% (vol)

(2. Molding process)
The mixture prepared as described above is molded into a shape close to a desired shape under a pressurized / heated (or normal temperature) environment using a mold or the like.

(3. Firing process)
After molding, the mixture containing abrasive grains is fired in a sintering furnace under pressure (or normal pressure) and heating environment. In the case of a dry mixture, it is filled in a predetermined baking mold. In the case of a wet mixture, after drying, it is set in a predetermined firing mold and fired under firing conditions suitable for the characteristics of the resin to finish as the resin bond grindstone 1.

(Whetstone wear test by high reciprocating grinding)
In addition to the resin bond grindstone 1 containing the CNT-coated abrasive grains 4 produced by the method of Example 1, a resin bond grindstone using uncoated abrasive grains (Comparative Example 1) and a CNT-coated abrasive grain having no chemical bond were used. A resin bond grindstone (Comparative Example 2) was prepared. While grinding the workpiece with these grindstones (high reciprocating grinding), the amount of grinding of the workpiece and the amount of wear of the grindstone were measured.

(Test condition)
Grinding was performed under the test conditions shown in Table 1. Using WASPALOY, which is a heat-resistant alloy, as the work piece, the grindstone wear amounts of Example 1 and Comparative Examples 1 and 2 were compared.

(Test results)
FIG. 5A shows the amount of grinding (the amount of the workpiece ground) and the amount of wear of the grindstone itself when the resin bond grindstone of Comparative Example 1 (conventional abrasive grains without chemical bonding or CNT coating) is used. Shows the relationship with. FIG. 5B shows the relationship between the grinding amount and the wear amount of the grindstone itself when the resin bond grindstone of Comparative Example 2 (CNT-coated abrasive grains without chemical bonds) is used. On the other hand, FIG. 5C shows the grinding amount (volume of the workpiece removed by grinding) and the wear of the grindstone itself when the resin bond grindstone 1 of Example 1 (CNT-coated abrasive grains having chemical bonds) is used. The relationship with the quantity is shown. Here, "having a chemical bond" means that the copolymer B having an oxazoline group is interposed in the abrasive grain layer 2, so that the functional groups Y and Z of the CNT 8 and the bond material 5 (phenol resin) are chemically bonded. It means that a bond was formed. It should be noted that FIG. 6 shows a linear approximation of the test results under each condition of the grindstone wear amount per unit volume removal amount of the workpiece (FIGS. 5 (a), 5 (b) and 5 (c)). Tilt) is shown.

(Effect of presence / absence of CNT coating)
Comparing the results of Comparative Examples 1 and 2 under the same conditions with the results of Example 1, as shown in FIGS. 5 and 6, under the test conditions where the reciprocating frequency of the workpiece is 500 rev / min, a normal grindstone is used. It is observed that the amount of grindstone wear per unit volume removal amount tends to decrease in the case of Example 1 (grindstone using CNT-coated abrasive grains having chemical bonds) than in the case of Comparative Example 1 using grains. Was done.

(Effect of presence or absence of chemical bond)
Comparing the results of Comparative Example 2 under the same conditions with the results of Example 1, as compared with the CNT-coated abrasive grains (Comparative Example 2), which have no chemical bond and depend only on the anchor effect for holding the abrasive grains. It was observed that the amount of grindstone wear per unit volume removal amount of CNT-coated abrasive grains having chemical bonds (Example 1) was clearly reduced.

Under high reciprocating grinding conditions with a workpiece reciprocating frequency of 500 rev / min (ie, conditions where the maximum abrasive depth of cut per unit time is large), rather than partial wear of the abrasive grains due to continuous contact with the workpiece. , It is known that the wear of the grindstone due to "falling off of the abrasive grains themselves" becomes remarkable. According to the present invention, the resin bond grindstone 1 of the first embodiment has an improved grindstone life even under such high reciprocating grinding conditions, and the high abrasive grain holding power of the CNT-coated grindstone 4 having a chemical bond appears. The inventors speculate. From FIG. 6, it can be seen that under high reciprocating grinding conditions with a workpiece reciprocating frequency of 500 rev / min, the grindstone life is 1.81 times longer than in the case of ordinary abrasive grains (Comparative Example 1). On the other hand, it can be seen that the life of the grindstone is 1.63 times longer than that of the CNT-coated abrasive grains without chemical bonds (Comparative Example 2). From this, it can be said that there is a sufficient advantage as compared with the CNT-coated abrasive grains (Comparative Example 2) which have no chemical bond and depend only on the anchor effect AE for the retention of the abrasive grains 6.

Although the present invention has been described with reference to the above embodiments and examples, the scope of rights included in the present invention is not limited to these embodiments and examples.

According to the present invention, the abrasive grain layer 2 is used to bond the CNT 8 and the bond material 5 by the actions of both the physical anchor effect AE due to the CNT 8 and the chemical bond due to the introduction of the functional groups Y and Z. Since it is possible to dramatically increase the abrasive grain holding force of the resin bond grindstone 1, it is possible to suppress the falling of the coated abrasive grains 4 during the abrasive grain processing, and to significantly improve the tool life and the abrasive grain processing performance of the resin bond grindstone 1. ..

The resin bond grindstone 1 of the present invention preferably includes the copolymer B bonded to the functional group Y of the CNT coating 7 and the functional group Z of the bond material 5, so that the CNT coating 7 and the bond material 5 are chemically bonded to each other. Since the resin can be firmly adhered, there is an effect that a high abrasive grain holding force, which cannot be obtained only by the physical anchor effect AE, can be exhibited.

As described above, the present invention has very high industrial applicability and industrial applicability.

1 Resin bond grindstone 2 Abrasive grain layer 3 Base metal 4 Coated abrasive grains 5 Bond material 5'Modified resin bond material 6 Abrasive grains 7 Carbon nanotube (CNT) coating 7'Modified carbon nanotube (CNT) coating 8 Carbon nanotube (CNT)
AE Anchor effect B Copolymer C Chemical bond X Functional group provided on the surface side of the abrasive grains X'Provided on the surface side of the functional group Y CNT attached to the copolymer that binds to the functional group X of the abrasive grains. Functional group Y'Functional group attached to the copolymer that binds to the functional group Y of CNT Z'Functional group provided on the surface side of the bond material Z'Functional group attached to the functional group Z of the bond material. Basic

Claims (6)

With a large number of coated abrasive grains,
A resin bond material that combines the coated abrasive grains to form an abrasive grain layer,
In the resin bond grindstone equipped with
The coated abrasive grains are
Abrasive grains and
A carbon nanotube coating that wraps around the surface of the abrasive grains and is configured so that carbon nanotubes are entangled with each other.
And
The carbon nanotube has a functional group Y, the bond material has a functional group Z, and the functional group Y and the functional group Z are constituent elements at the interface between the carbon nanotube and the bond material. resin bonded grinding wheel, wherein the chemical bond is polarized standing to. One of the functional group Y and the functional group Z is one or more functional groups selected from the group consisting of a phenolic hydroxyl group, a hydroxyl group, a carboxyl group and an amino group, and the other is an isocyanate group, an epoxy group and an acid. The resin according to claim 1, wherein it is one or more functional groups selected from the group consisting of anhydrous functional groups, and a chemical bond between the functional group Y and the functional group Z is present. Bond grindstone. The functional group Y and the functional group Z are one or more functional groups selected from the group consisting of a carboxyl group, a phenolic hydroxyl group, a hydroxyl group, an acid anhydride functional group, and a thiol group, and A copolymer B is interposed between the functional group Y and the functional group Z, and the functional group Y'that the copolymer B has and the functional group Y have a chemical bond and the copolymer B has. The resin bond grindstone according to claim 1, wherein a chemical bond between the functional group Z'and the functional group Z is present. The resin bond grindstone according to claim 3, wherein the copolymer B is a copolymer containing a 2-oxazoline-based monomer (a) as an essential constituent unit. The copolymer B is a copolymer containing a 2-oxazoline-based monomer (a) and a nitrogen-containing heterocyclic monomer (b) as constituent units, and is a copolymer.
The resin bond grindstone according to claim 3, wherein the copolymer B contains 1 to 90 mol% of the 2-oxazoline-based monomer (a). The resin bond grindstone according to any one of claims 3 to 5, wherein the functional group Y'and the functional group Z'are oxazoline groups.

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