JPS6044576A - Composition for grinder - Google Patents

Abstract

PURPOSE:To provide the titled composition resistant to the heat generated in grinding, and enabling the autogenous development of the grinding edges continuously even at a high temperature, by using an abrasive binder comprising a thermosetting resin containing a specific diallyl terephthalate copolymer as an essential component, and compounding the binder with a curing agent and abrasive grains. CONSTITUTION:The binder of the objective composition contains (A) a diallyl terephthalate copolymer obtained by the copolymerization of (i) the diallyl terephthalate of formula I and (ii) an aromatic hydrocarbon of formula II (R1 and R2 are H or lower alkyl; n is 1-3) having one or more H atoms at the benzyl group, as an essential component, and optionally (B) 5-200PHR of a thermosetting resin such as diallyl phthalate, etc. and 3-50PHR of a thermoplastic resin such as PVA, etc. The binder is compounded with abrasive grains such as alumna, etc. and a curing agent such as benzoyl peroxide, etc. to obtain the objective composition. EFFECT:It can be applied to the grinding of nonmetals having low heat conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition for an abrasive body using a synthetic resin as a binder, and an abrasive body obtained by curing the composition.

Conventional synthetic resin binders (resinoid binders) include phenol resin, polyvinyl alcohol, polyurethane,
Epoxy resins, unsaturated polyester resins, etc. are known. Resinoid grindstones are more elastic and have greater tensile strength than inorganic binders such as vitrified binders, and can be used for high-speed rotation, so they are used as cutting wheels, roll grinding wheels, and casting stones. However, in both cases, the resin holding the abrasive grains deteriorates due to the heat generated by the grinding process, making it difficult to perform high-speed grinding as it tends to cause clogging and cracking. For those using unsaturated polyester resin as a binder, a grinding wheel with distributed fine water particles has been developed, which provides excellent polishing and polishing for difficult-to-grind materials with poor thermal conductivity.
Although it is known to exhibit grindability, it is not necessarily easy to manufacture because there are many factors such as adjusting the water content and the fine particles of water. Furthermore, it is difficult to maintain uniform dispersion of the resin, abrasive grains, and other auxiliary agents, which have very different specific gravities, in liquid form, and the pot life of the composition is relatively short.

The present inventors have searched for various binders that have excellent heat resistance, mechanical strength, and can obtain an appropriate degree of bonding, and have conducted research in order to obtain a composition for abrasive bodies that can be easily manufactured. The present invention was completed based on the discovery that a composition using a thermosetting resin containing a terephthalic acid diallyl ester copolymer as a main component can easily provide an excellent abrasive body. That is, the abrasive body according to the present invention uses as a binder a thermosetting resin whose main component is a terephthalic acid diallyl ester copolymer, which was previously proposed by the present inventors and has not been described in any literature. This makes it possible to reduce the amount of time required for blending the binder, and it can withstand the heat generated during grinding. Even at high temperatures, self-synthesizing blades occur continuously, so it is possible to grind until dressing is required. It can exhibit excellent performance as an abrasive body that lasts for an extended period of time.

Another object of the present invention is to provide a composition for producing the abrasive body described above, which uses a thermosetting resin containing the terephthalic acid diallyl ester copolymer as a main component as a binder.

That is, the present invention is a composition for an abrasive body characterized by using a thermosetting resin containing a terephthalic acid diallyl ester copolymer as an essential component as a binder, and containing a curing agent and abrasive grains.

The terephthalic acid diallyl ester copolymer referred to in the present invention is the terephthalic acid diallyl ester (1) represented by the formula (1) and the formula (2) (wherein, RI R2 is a hydrogen atom and a lower alkyl group, respectively). Indicates the group selected from the group, Kamegawa 1
terephthalic acid diallyl ester copolymer derived from an aromatic hydrocarbon having at least one hydrogen atom at the benzyl position represented by
a), one seven-piece unit of formula (2) is attached to the terminal of one seven-piece unit of formula (1), and the allyl group of one seven-piece unit of formula (1) and its CI and/or C group at the benzyl position. It has a carbon-carbon bonded structure. Further (b).

The number of monomer units of the formula (1) in the carbon-carbon bonded molecular chain portion formed by the allyl group of the monomer unit of the formula (1) of the copolymer is 3 to 11, preferably 3 to 10. It is a copolymer with structural characteristics. This terephthalic acid diallyl ester copolymer has the formula (
1) It can be produced by reacting the compound and the compound of formula (2) in the presence of a known organic peroxide or azo compound catalyst. Details of this copolymer are described in Japanese Patent Application No. 57-189981 filed by the present applicant.

The thermosetting resin containing a terephthalic acid diallyl ester copolymer as an essential component as used in the present invention may of course be the copolymer itself, and if necessary, the resin's melt viscosity, curing speed, initial tackiness, etc. In order to adjust diallyl phthalate, diallyl isophthalate, diallyl terephthalate, tetrabromo diallyl phthalates, tetrachlorodiallyl phthalates, diallyl crocinde 1-. Triallyl isocyanurate, triallyl cyanurate.

Monomers that react with terephthalic acid diallyl ester copolymers such as triallyl trimellitate and triallyl phosphate under the curing conditions, or have a number average molecular weight of approximately 20.
Oligomers of less than 0.00 may be added alone or in appropriate combinations. The amount to be blended should be determined based on the workability, coagulation properties, melt viscosity, curing speed, mechanical bullet holes, etc. of the composition, so it cannot be generally specified, but the weight part per 100 parts by weight of the copolymer is PHR. When expressed in units of , it is desirable to set it to 30 PHR or less.

In addition, a mixture of the copolymer with one or more of thermosetting resin, thermoplastic resin, and rubber can also be used as a thermosetting resin containing terephthalic acid diallyl ester copolymer as the main component. be able to.

Examples of the thermosetting resin that can be used in the present invention include polymers of diallyl phthalate, diallyl isophthalate, and diallyl terephthalate, or copolymers thereof, unsaturated polyesters, epoxy resins, and poxy acrylates. There is no particular restriction on the amount to be added, but if necessary, it is effective if used within the range of 5 to 200 PHR.

Examples of thermoplastic resins that can be used in the present invention include polyvinyl alcohol, polyvinyl acetals, ABS
, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polybutadiene, chlorinated polyethylene.

Examples include ethylene-α-olefin copolymer and ethylene-vinyl acetate copolymer, which can be used in any form such as latex, powder, or block. When used in combination with the terephthalic acid diallyl ester copolymer of the present invention, the blending amount should be determined in order to better exhibit the heat resistance, water resistance, oil resistance, and toughness of the copolymer, and to improve workability. Consideration FIi
If shifted, 2 to 60 PH'R1, preferably 3 to 50 PH'R1
It is effective if used within the R range.

Any type of rubber can be used in the present invention, and the rubber may be in the form of latex or block. Examples include natural rubber, isoprene rubber, chloroprene rubber, and neoprene rubber.

Nitrile rubber, butadiene rubber, butadiene-acrylonitrile rubber, butadiene-styrene rubber, urethane,
Examples include epichlorohydrin rubber, rubbery chlorinated polyethylene, etc., and the blending amount is 2 to 50 PI-IR, preferably 3 to 50 PI-IR, in order to exhibit the characteristics of the terephthalic acid diallyl ester copolymer and also improve workability. 40P
It is effective if used within the HR range.

If two or more of the above thermosetting resins, thermoplastic resins, and rubbers are used together, the total amount will be 200P l-
It is better to keep it below IR.

Next, the composition for an abrasive body according to the present invention will be explained. The feature of this composition lies in the use of a thermosetting resin mainly composed of the above-mentioned diallyl terephthalate copolymer as a binder, and this binder and a suitable abrasive or abrasive material (hereinafter referred to as abrasive grains). , and a filler, a grinding aid, a hardening agent, and if necessary a reinforcing material, a porosity agent, an anti-wear agent, a silane coupling agent, and a surfactant, to obtain an abrasive body composition.

Abrasive grains include alumina, silicon carbide, sintered alumina, alumina-zirconia, artificial diamond of various particle sizes, artificial abrasives such as cubic boron nitride, corundum,
Natural abrasives such as garnet can be used. The blending amount of these abrasive grains is 20 per 100 parts of the binder.
An example of the amount is 800 parts by volume, preferably 30 to 600 parts by volume.

Fillers and grinding aids include, for example, cryolite, silica,
Calcium fluoride, barium sulfate.

Potassium sulfate, calcium carbonate, etc. are used and are also effective as anti-shrinkage agents during hardening of the binder. The amount of these fillers and grinding aids may be 60 to 980 parts by volume, preferably 90 to 750 parts by volume per 100 parts by volume of the binder.

As a curing agent, benzoyl peroxide, dicumyl peroxide,
Organic superstrengtheners such as ditertiary butyl peroxide, strong tertiary butyl perbenzoate can be used, e.g. binder 10
m such as 0.1 to 6 parts by weight per 0 parts by weight are useful.

When using reinforcing materials, glass am, silica mtd1
．． Inorganic reinforcing materials such as silicate glass fiber, asbestos m 11 , alumina m fiber, carbon fiber, boron fiber, beryllium fiber, organic reinforcing material such as polyester, polyamide, polyimide, polyimide amide, polybismaleimide, bismaleimide triazine resin, It can be selected from IjAll, woven fabric, non-woven fabric, mat, etc. made of these, and is effective in improving the mechanical strength of the polishing body, reducing brittleness, etc., and is also effective in increasing the peripheral speed at which the polishing body is used. The amount of reinforcing material is per 10 weight (6) parts of binder.
An example of m is 1 to 200 ω parts, preferably 1 to 1100 TIX parts.

In order to adjust the porosity m of the abrasive body, for example alumina hollow spheres may be used as a pore agent if necessary. The amount of the pore agent to be added depends on the particle size of the abrasive grains, the abrasive grain ratio, the degree of bonding, etc., and cannot be determined in general.
5 to 200 parts by volume per 0 parts by volume, preferably 10 to 17 parts by volume
An example of the amount is 0 parts by volume.

Wear-resistant materials include molybdenum disulfide, boron nitride, potassium titanate, calcium metasilicate,
Mica, colloidal silica, colloidal alumina, colloidal titanium, zinc oxide, talc, polytetrafluoroethylene, etc. are used. Since these are also effective as reinforcing materials, there is no particular restriction on the blend ω, but in order to improve wear resistance, for example, 1 per 100 parts by weight of the binder.
Amounts such as 1 to 100 parts by weight, preferably 5 to 50 parts by weight, are useful.

The terephthalic acid diallyl ester copolymer used in the present invention is a relatively hydrophobic resin, which improves compatibility with abrasive grains and other compounds, and helps the abrasive grains to be coated uniformly with the binder. It is effective to add a silane coupling agent or the like to improve adhesion and to produce a particularly hard abrasive body. The amount added depends on the abrasive grain ratio, etc., but for example, ω may be 0.005 to 5 parts by weight, preferably 0.01 to 3 parts by weight, per 100 parts by weight of the binder.

Furthermore, when a liquid medium such as water or an organic solvent is used in producing the composition, adding a surfactant may be advantageous since uniform mixing and dispersion can be achieved. The amount added may be appropriate, but for example, 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of the binder.
An example is m like the biosphere.

The abrasive body thus obtained can be used in both wet and dry grinding methods, and the binder has good heat resistance, so even if the temperature of the abrasive grain surface rises due to heat generated during grinding, the binder will remain stable. It does not soften and can firmly hold the abrasive grains, and together with the toughness of the binder, it does not lose its appropriate elasticity even at high temperatures.
Because the whitening process occurs smoothly and continuously, there is no chance of clogging, blinding, or spillage, and the grinding time is longer before dressing is required, making it difficult to grind. Non-metals, carbon products, refractories.

Concrete, china, ceramics, stone.

It has excellent grindability and can be applied to plastics, rubber, etc. Furthermore, it can sufficiently withstand the circumferential speed of 2000 m 2 /il+ of the currently commonly used vitrified grindstone.

This will be explained below using examples.

Examples Comparative Example ゛ [Production of terephthalic acid diallyl ester copolymer and internal volume 120#' with pressure gauge
A polymerization tank manufactured by Jacquera 14SIJS304 was used. The contents of this polymerization tank are shown in Table 1 below. Aromatic hydrocarbons (HC
) 60 kO, the air in the tank was replaced with nitrogen, the pressure was reduced, and the polymerization tank was sealed.

While stirring, the temperature was raised to 140°C, and diallyl terephthalate was added at a predetermined rate from the outer pipe of a double pipe nozzle, and at the same time di-tert-butyl peroxide (DTBPO) and formula (2) were added.
and an aromatic hydrocarbon (11G) at a molar ratio of 0.5:1, and the mixture was supplied to the polymerization tank at a predetermined rate. Tank temperature 140℃, polymerization tank pressure 0.3-2kg/
It is dG. When the supply of predetermined amounts of diallyl terephthalate, aromatic hydrocarbon, and di-tart-butyl peroxide was not completed, heating was stopped and the reactor was cooled to around room temperature to complete the polymerization reaction. Table 1 shows the feed rates and amounts of diallyl terephthalate, aromatic hydrocarbons, and tert-butyl peroxide.

The polymerization reaction solution obtained above was evaporated using a thin film evaporator.
The volatile components were distilled off, and the ratio of unreacted aromatic hydrocarbons in the evaporation residue to the combination η1 of the copolymer and unreacted diallyl terephthalate was set to 0.3:1 by weight, and then the evaporation residue was evaporated. The copolymer was precipitated by dropping the supplied diallyl terephthalate into a stirring tank containing methanol in an amount 5 times the weight by weight while stirring. The precipitated copolymer was thoroughly washed with the same amount of methanol, filtered, dried, and pulverized to obtain a powdery copolymer. The yield and physical properties of the copolymer are shown in Table 1.

Table 1 [Preparation of Binder] The substances shown in Table 2 were blended with the terephthalic acid diallyl ester copolymer according to Production Examples 1 and 2 to prepare a binder. E in Table 2 is for comparison, and an ortho diallyl phthalate prepolymer and an unsaturated polyester were used instead of the above copolymer.

Table 2 (Parts by weight) [Polyester with an acid value of 28.0 and a softening temperature of 80°C, obtained by dehydration condensation of 1 mole by melting method *2 JSR-PN3OA manufactured by Japan Synthetic Rubber Co., Ltd. [Polyester manufacturing and physical property testing tool] The substances shown in Table 3 are blended with the binders A-E in Table 2,
These compositions were thoroughly kneaded using approximately the same weight of methyl ethyl ketone, the solvent was removed, the particles were sized, and a grinding wheel having an outer diameter of 90 mm was manufactured by hot pressing at 170°C. This was used as a test piece for measuring the propagation speed of ultrasonic waves in the thickness direction at a frequency of 200 KHz, and the measurement results are also listed in Table 3. It is generally accepted that the higher the ultrasonic propagation speed, the stronger the strength, and the grinding wheels obtained in the present invention all have improved strength.

Next, the outer diameter is 90. , thickness 25 W, hole diameter 15.88 l, and the results of measuring the rotational fracture strength are not shown in Table 4. The measurement method was performed according to JIS R6240.

Table 5 shows the results of examining the grindability using grinding wheels manufactured to the same dimensions.

An electric portable grinder (220v, 0.75
Kw, IH, 7000 rpm), the grinding load was 10 kg, the movement speed of the ground object was 1.0 m/Il, and the grinding time was 101i1. For comparison, the test results of the vitrified grinding wheel C46J' (Comparative Example 2), the grinding wheel using polyvinyl alcohol as a binder (Comparative Example 3), and the grinding wheel using phenolic resin (Comparative Example 4) are shown in Table 5. Also listed. The grinding wheel according to the invention shows improved results in rotational fracture strength or grindability.

Chiku 3 Todoroki (1st grade is the weight department unless otherwise specified) *I J
IS 2CWA# 46 Kikuchi J Is 2CwA# 100 Yoneyaju M Part Table 4

Claims (1)

[Scope of Claims] A composition for an abrasive body, characterized in that it contains a thermosetting resin containing a terephthalic acid diallyl ester copolymer as an essential component as a binder, a curing agent, and abrasive grains. However, the terephthalic acid diallyl ester copolymer refers to a copolymer of terephthalic acid diallyl ester and an aromatic hydrocarbon having at least one hydrogen atom at the benzyl position represented by the following formula. In the above formula, RI R2 each represents a group selected from the group consisting of a hydrogen atom and a lower alkyl group, and 1=an integer of 1 to 3.