JPH01158030A - Materials for cutting and cutting molded products - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to cutting materials and cutting molded products made of thermosetting norbornene-based polymers, and more particularly, to materials that are excellent in machinability and safety, lightweight and compact in size. The present invention relates to cutting materials and cutting molded products made of thermosetting norbornene-based polymers with good stability.

Conventional technology Traditionally, materials for processing (round bars,
It is a well-known technology to produce various mechanical parts by cutting and other machining processes in the same way as with metals.

Compared to injection molding, cutting of plastic materials can economically produce parts in small quantities, produce parts with high dimensional accuracy, and easily produce parts with shapes that are difficult to injection mold. It has many advantages such as Moreover, standard tools for metal processing can be used to process these plastic materials.

However, conventional engineering plastics have excellent heat resistance and mechanical strength, but even though they have high heat resistance, because they are thermoplastic resins, the frictional heat generated during mechanical cutting can cause them to reach near their melting point. The temperature increases;
Since the cutting material melts and it is difficult to produce a smooth surface, the cutting surface has to be cooled, which is a drawback. Furthermore, since the material for cutting is molded by injection molding, there are restrictions on molding, such as making it difficult to create large parts and requiring expensive molds. Among the conventional methods, so-called cast nylon has the advantage of being able to produce larger products compared to conventional injection molding and extrusion molding, as it polymerizes and molds by directly pouring nylon into a mold. It has the disadvantage of insufficient dimensional stability, which is an extremely important performance for cutting materials.

Problems to be Solved by the Invention The inventors of the present invention have conducted extensive research to develop cutting materials that are lightweight, inexpensive, and have good machinability, dimensional stability, and heat resistance. It has been found that it is useful to use a polymer obtained by bulk ring-opening polymerization of a polycyclic norbornene monomer in the presence of the present invention, and based on this knowledge, the present invention has been completed.

Means for solving the problem, that is, the gist of the present invention is that the ignition point obtained by bulk ring-opening polymerization of a tricyclic or higher norbornene monomer in the presence of an antioxidant is 120 ° C. or higher, and The present invention relates to a thermosetting cutting material having a glass transition temperature of 80° C. or higher, and a cut molded product obtained by cutting the material.

Hereinafter, the constituent elements of the present invention will be explained in detail.

(Norbornene Monomer) The monomer used as a raw material for the processing material in the present invention is a tricyclic or higher polycyclic norbornene monomer. By having a tricyclic or higher polymer, a polymer having a high heat distortion temperature can be obtained and can satisfy the heat resistance required for cutting processing.

In addition, in the present invention, it is necessary to make the produced polymer thermosetting type, and for this purpose, it is necessary to use at least 10% by weight, preferably 30% by weight or more of crosslinking monomers based on the total monomers. preferable. By using a thermosetting type, melting due to frictional heat during cutting can be prevented, and machinability is significantly improved.

Examples of norbornene monomers having a tricyclic or higher structure include bicyclics such as dicyclopentadiene and dihydrodicyclopentadiene, tetracyclics such as tetracyclododecene, bicyclics such as tricyclopentadiene, Heptacyclics such as tetracyclopentadiene, alkyl substituted products thereof (e.g., methyl, ethyl, propyl, butyl substituted products, etc.), alkylidene substituted products (e.g., ethylidene substituted products, etc.), aryl substituted products (e.g., phenyl substituted products, etc.), , tolyl substituted product, etc.).

On the other hand, the crosslinking monomer is a polycyclic norbornene monomer having two or more reactive double bonds, and specific examples thereof include dicyclopentadiene, tricyclopentadiene, and tetracyclopentadiene. Therefore, when the norbornene monomer and the crosslinking monomer are the same, there is no need to use any other crosslinking monomer.

These norbornene monomers may be used alone or in combination of two or more.

Tricyclic or higher norbornene monomers can also be obtained by heat treating dicyclopentadiene. The heat treatment conditions were as follows: dicyclopentadiene was heated at 120 to 250°C under an inert gas atmosphere at a temperature of 0.5
An example is a method of heating for ~20 hours. This heat treatment yields a monomer mixture containing pentacyclopentadecadiene and unreacted dicyclopentadiene. During the heat treatment, genophiles such as bicyclic norbornene, styrenes, unsaturated carboxylic acid esters, unsaturated nitriles, etc. may be appropriately allowed to coexist.

In addition, 2-norbornene, 5-methyl-2-norbornene, 5-ethylidene-2-norbornene, 5-ph, uni-2-norbornene, etc. that can be ring-opening polymerized with one or more of the tricyclic or more norbornene monomers mentioned above. Bicyclic norbornene type Motzuma-1 or cyclobutene, cyclopentene, cyclopentadiene, cyclooctene,
Monocyclic cycloolefins such as cyclododecene can be used in combination without impairing the purpose of the present invention.

(Metathesis Catalyst System) The catalyst used in the present invention may be any metathesis catalyst system known as a catalyst for bulk polymerization of norbornene monomers (for example, JP-A No. 58-127728, JP-A No. 58-129013, JP-A No. 58-129013; No. 59-51911, No. 60
-79035, 60-186511, 61-1
No. 26115, etc.), there are no particular restrictions.

Metathesis catalysts include tungsten, molybdenum,
Halides such as tantalum, oxyhalides 1,
oxides, organic ammonium salts, etc., and suitable examples include tungsten hexachloride, tungsten oxytetrachloride, tungsten oxide, tridodecyl ammonium kungestate, methyltricaprylammonium kungestate, tri(tridecyl) ammonium Tungsten compounds such as tungstate, trioctyl ammonium tungstate, molybdenum dipentachloride, molybdenum oxytrichloride, tridodecyl ammonium molybdate, methyltricabrylammonium molybdate, tri(tridecyl) ammonium molybdate, trioctyl ammonium molybdate, etc. Examples include tantalum compounds such as molybdenum compounds and tanker dipentachloride. Among these, it is preferable to use a catalyst that is soluble in the norbornene monomer used in the reaction, and from this point of view, organic ammonium salts are preferred. When the catalyst is a halide, the catalyst can be solubilized by prior treatment with an alcohol compound or a phenol compound. Further, if necessary, a Lewis base such as benzonitrile or tetrahydrofuran, or a chelating agent such as acetylacetone or acetoacetic acid alkyl ester may be used in combination, thereby preventing premature polymerization.

Examples of the activator (cocatalyst) include alkyl aluminum halides, alkoxyalkylaluminum halides, aryloxyalkylaluminum halides, organotin compounds, and suitable examples include ethyl aluminum dichloride, diethylaluminum monochloride, ethyl aluminum Sesquichloride, diethylaluminium iodide, ethylaluminum dichloride, propylaluminum dichloride, probylaluminum diiodide, isobutylaluminum dichloride, ethylaluminum dichloride, methylaluminum sesquichloride, methylaluminum sesquipromide, tetrabutyltin, alkylaluminum halides and alcohols and preliminary reaction products.

Among these activators, alkoxyalkylaluminum halides and aryloxyalkylaluminum halides have an appropriate pot life at room temperature even when mixed with catalyst components, so they are operationally advantageous (for example,
In the case of alkylaluminum halides, polymerization starts immediately when a catalyst is mixed. The initiation of polymerization can be delayed by using a regulating agent such as alcohol or the like (for example, JP-A-58-129013 and JP-A-61-120814). If these regulators are not used, consideration must be given to equipment and operation so that even those with a short pot life can be used.

However, in the case of a catalyst system with a short pot life, the reaction proceeds rapidly and it is difficult to efficiently remove the reaction heat, so the pot life at 25°C is 5 minutes or more, preferably 1
It is preferable to use one for 0 minutes or more, more preferably 30 minutes or more.

Further, in addition to the catalyst and activator, halogenated hydrocarbons such as chloroform, carbon tetrachloride, hexachlorocyclopentadiene, etc. may be used in combination (for example, JP-A-60-7
No. 9035). Furthermore, halides such as tin tetrachloride, silicon tetrachloride, magnesium chloride, and germanium chloride may be used in combination.

The amount of the metathesis catalyst is usually about 0.01 to 50 mmol, preferably 0.01 mmol to 1 mol of the norbornene monomer.
It is used in a range of 1 to 10 mmol. The activator (cocatalyst) is generally used in an amount of 0.1 to 200 (mole ratio), preferably 2 to 10 (mole ratio), based on the catalyst component.

Both the metathesis catalyst and the activator are preferably used after being dissolved in a monomer, but they may also be used after being suspended or dissolved in a small amount of a solvent as long as the properties of the product are not essentially impaired.

(Antioxidant) The antioxidant used in the present invention includes phenolic,
There are various antioxidants for plastics and rubber, including phosphorus-based and amine-based antioxidants. These antioxidants may be used alone or in combination. The blending ratio is such that the ignition point of the norbornene-based polymer is 120°C or higher, preferably 1
The range is such that the temperature is 30°C or higher, and is usually 0.5% by weight or more, preferably 1 to 3% by weight based on the norbornene polymer.
Weight%. If the blending ratio of the antioxidant is extremely low, the ignition point of the molded product cannot be raised. Although there is no particular upper limit to the blending ratio, an excessively large amount of antioxidant is not preferred, as it is uneconomical and may inhibit polymerization. In particular, it has been found that amine-based antioxidants inhibit polymerization reactions when used in an amount of 2% by weight or more.
．． It is preferable to use it in a range of 5 to 2% by weight.

Examples of phenolic antioxidants include 4.4-dioxydiphenyl, hydroquinone monobenzyl ether, 2.4-dimethyl-6-t-butylphenol, 2.
．． 6-di-t-butylphenol, 2,6-di-amylhydroquinone, 2,6-di-t-butyl-p-cresol, 4-hydroxymethyl-2,6-di-t-butylphenol, 4,4'-methylene- Examples include bis-(6-t-butyl-0-cresol), butylated hydroxyanisole, phenol condensate, butylenated phenol, dialkyl phenol sulfide, high molecular weight polyhydric phenol, and bisphenol.

Examples of phosphorus-based antioxidants include aryl or alkylaryl phosphites such as tri(°phenyl)phosphite and tri(nonylphenyl)phosphite.

Examples of amine antioxidants include phenyl-α-
Naphthylamine, 4.4'-dioctyldiphenylamine, N,N'-di-β-naphthyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-cyclohexyl-p -phenylenediamine, N,N'-di-0-tolyl-ethylenediamine, alkylated diphenylamine, and the like.

As these antioxidants, various commercially available products can be used in addition to those mentioned above. In addition, the antioxidant may be one that can be copolymerized with the monomer, and specific examples include 5
- Norbornenylphenol compounds such as (3,5-di-t-butyl-4-hydroxybenzyl)-2-norbornene are exemplified (JP-A-57-83
(See Publication No. 522).

The antioxidant is usually added to the reaction stock solution containing the norbornene monomer in advance under the polymerization conditions of the reaction injection molding method described below (depending on the method).

(Polymerization Conditions) In the present invention, a cutting material is obtained by ring-opening polymerization of a norbornene monomer in bulk in the presence of an antioxidant. Substantially bulk polymerization may be used, but from the viewpoint of the performance of the material, it is desirable not to use an inert solvent in the preparation of the catalyst.

In a preferred method for producing processing materials, the norbornene-based monomer is divided into two parts, placed in separate containers, and the metathesis catalyst is added to one part, and the activator is added to the other, to prepare two types of stable reaction solutions. do. These two types of reaction solutions are mixed and then poured into a mold of a predetermined shape, where ring-opening polymerization is carried out in bulk. A predetermined amount of antioxidant is added to at least one of the two liquids.

In order to prevent so-called cavities from occurring in the cured product (cutting material), it is preferable to control the mold temperature so that the maximum curing exothermic temperature of the contents does not exceed 160°C. There is no particular limit to the injection pressure, but it is usually 10 kg/c.
rrf' or less is sufficient, and it is preferably carried out under normal pressure.

In addition, the polymerization time may be selected appropriately in relation to the exothermic temperature, but if the polymerization time is too short, the maximum curing exothermic temperature may be reduced to 1.
It becomes difficult to control the temperature below 60°C.

Note that the maximum curing exothermic temperature may exceed 160° C., but in that case, it is necessary to pay attention to the cooling conditions of the cured product so as not to slowly cool it and to prevent the formation of cavities.

The components used in the polymerization reaction are preferably stored and operated under an inert gas atmosphere such as nitrogen gas. The mold may be sealed with an inert gas, but it is not necessary.

(Optional components) By blending various additives such as fillers, pigments, colorants, elastomers, dicyclopentadiene thermopolymerized resins, flame retardants, and sliding agents, the characteristics of the cutting material of the present invention can be improved. can be modified.

The additives are used by being mixed in advance with one or both of the reaction solutions.

Fillers include inorganic fillers such as glass, carbon black, talc, calcium carbonate, and mica.

Elastomers include natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SBR
), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), ethylene-brobylene-dieneterpolymer (EPDM), ethylene-vinyl acetate copolymer (EVA) ) and their hydrides. The amount of these elastomers to be blended may be appropriately selected depending on the purpose, but when added in an amount of about 0.5 to 3% by weight, the machinability becomes even better.

(Properties of material for processing) The material for cutting obtained in this way can be made into various shapes such as round bars, square bars, tubular shapes, sheet shapes, etc., and can also be made into three-dimensional shapes of predetermined shapes. can be. It is of high quality with virtually no pores, and has a small diameter or thickness (20 mm or more, preferably 50 mm or more).Since it uses reaction injection molding, It can be easily increased in size, and in the case of a round bar, for example, it can be manufactured to a diameter of about 300 mm or even larger.

Note that the pores herein are those that can be identified when the cut surface is visually observed, and have a diameter of approximately 0.1 mm or more. The expression "substantially free of pores" means that there are no pores in any cross section when the material for processing is cut at intervals of 100 mm. Such pores are 0.5~
It can also be detected by sending 10 MHz ultrasonic waves through the material and detecting the disturbances in the reflected waves. Commercially available ultrasonic flaw detectors can be utilized for such purposes.

The glass transition temperature of such a material for cutting is 80°C or higher, preferably 1°C from the viewpoint of preventing thermal deformation during cutting.
It is necessary that the temperature is 00°C or higher, particularly preferably 130°C or higher.

In addition, the ignition point measured by high-pressure differential thermal analysis (using a high-pressure differential thermal balance as a device and under high-pressure oxygen, the sample was frozen and crushed, and 10 mg was passed through a 100-mesh wire mesh).
The point where the differential heat curve shows a sharp rise is defined as the ignition point. ) is 120°C or higher, preferably 130°C or higher. If the ignition point is low, coloration may occur during cutting due to carbonization, the cut portion may become brittle, and it may cause spontaneous combustion if the cutting waste is left in direct sunlight or at high temperatures.

It is desirable that the cutting material of the present invention is substantially free of unreacted norbornene monomers and volatile solvents. These volatile components volatilize during cutting, worsening the working environment and causing odor in the molded product after cutting. In that sense, in the thermobalance method (approximately 10 mg
A plate-shaped sample with a diameter of 3 to 4 mm was used. ),
400℃ under a nitrogen atmosphere at a heating rate of 20℃/min
Preferably, the weight loss on heating is 5% by weight or less, particularly 3% by weight or less.

The cutting material of the present invention has good dimensional stability due to its low water absorption, and has a specific gravity of about 1.1 or less, making it extremely lightweight even among plastics.

(Cutting Process) In the present invention, a molded product having a predetermined shape can be obtained by cutting the material for cutting using the same method as that for a metal material. The specific means of cutting is not particularly limited, and examples include lathe finishing, thread cutting, milling, drilling, and reaming.

When cutting a material for cutting, the material generates heat due to friction, but excessive heat generation causes deformation and coloring, so it is desirable to control the temperature to 200° C. or less.

This cutting material is then processed into various molded products by cutting, specific examples of which include bearings, gears,
Various parts such as racks, cams, shafts, levers, bearings, pulleys, drive gears, rollers, flanges, wheels, wear parts, liners, packets, washers, sliding plates, and insulators can be mentioned, and cutting of these parts can be mentioned. Molded products are used in ironwork/metal machinery, civil engineering and construction machinery, textile industry machinery,
It is used in a wide range of fields such as transportation and transportation machinery, food processing machinery, and other general machinery.

EXAMPLES The present invention will be explained in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited only to these Examples. Note that parts, percentages, etc. are based on weight unless otherwise specified.

Medicine 11 Tsuji 1 Phenolic antioxidant (trade name Irganox 259
Dicyclopentadiene (hereinafter referred to as DCP) containing 2% of DCP (manufactured by Ciba Geigy) was placed in two containers, and one contained 2% of diethylaluminum chloride (DE) for DCP.
AC) at a concentration of 33 mmolar and n-propatool at a concentration of 42 mmolar.
Silicon tetrachloride was added at a concentration of 9 mmolar and silicon tetrachloride at a concentration of 20 mmolar. On the other hand, tri(tridecyl)ammonium molybdate was added to DCP at a concentration of 4 mmolar.

Both reaction solutions kept at 25°C are mixed at a ratio of 1:1 using a gear pump and a power mixer. The pot life is 2.
It took about 10 minutes at 5°C. ) was injected from the top of the mold at approximately normal pressure into a steel mold with an open top having the shape shown in Table 1 under the heat removal conditions of the mold shown in Table 1. These series of operations were performed under a nitrogen atmosphere.

The round rod-shaped block material thus obtained was cut at intervals of 100 mm in the height direction, and the cross sections were visually observed.

The results are shown in Table 1.

In addition, the glass transition temperature (Tg) of each block material is 14
It was found that the heating range amount at 5 to 150° C. by the thermobalance method was in the range of 2 to 3%, and that the reaction was sufficiently progressing in all block materials.

Furthermore, as a result of measuring the ignition point by differential thermal analysis under high pressure of oxygen pressure 10 kg/crrr, it was found that all block materials were
The value exceeded 20°C.

Regarding machinability, all block materials could be cut, and there was no ignition or melting of the resin due to frictional heat during cutting, and the finished product was in good condition.

(Left below) As is clear from Table 1, in the examples of the present invention (experiment numbers 1 to 3) in which bulk polymerization was carried out while controlling the maximum curing exothermic temperature of the reactants to 160°C or less, the cut surface of the block material Although no pores were observed, the maximum curing exothermic temperature was high, and 16
It can be seen that in the case of comparative examples (experiment numbers 4 to 6) in which the temperature exceeds 0° C. and the cooling rate of the reactants is not controlled, a large number of pores are formed. Conventionally, in the RIM method using norbornene-based monomers, the reaction stock solution was injected after heating the mold, but when targeting thick molded products,
If the cooling rate is not controlled, a satisfactory material cannot be obtained (Experiment No. 6).

In order to examine the presence or absence of pores in relation to the length of the pot life of the Mitate ■ Yu reaction stock solution and the size (diameter) of the round rod-shaped block material, the amount of n-propatool added was 49.3 mmol. Round rod-shaped blocks of various diameters were obtained in the same manner as in Example 1 except for adjusting the concentration. The pot life of the reaction stock solution was 1 hour or more at 25°C. Shape of the mold and mold The heat removal conditions were as shown in Table 2.

Further, the Tg of each block material was 145 to 150°C, the heating range amount by thermobalance method was 2 to 3%, and the ignition point by differential thermal analysis was 120°C or more.

Table 2 *1: Based on the same evaluation method as in Table 1.

From the results shown in Table 2, it can be seen that when the pot life is lengthened, the time to start heat generation becomes longer, so productivity deteriorates slightly, but a block material with a larger diameter can be obtained without forming pores.

Irganox 259, a phenolic antioxidant, was dissolved at 2% in DCP and placed in two containers, one containing DEAC at a concentration of 33 mmol and n-
Proper tool was added at a concentration of 42.9 mmol, and silicon tetrachloride was added at a concentration of 20 mmol. On the other hand,
Tri(tridecyl)ammonium molybdate was added to DCP at a concentration of 4 mmol.

Both reaction solutions were mixed at a ratio of 1:1, and the inner diameter was 100 mmφ.
It was poured into a jacketed steel form having a height of 800 mm and maintained at a water temperature of 18°C.

After pouring, curing started approximately 20 minutes later, and the mold was removed 15 minutes later to obtain a round bar-shaped processing material (round bar block material) of 100 mmφ x 800 mm. These series of operations were performed under a nitrogen atmosphere.

A part of the processing material obtained in this way was sampled, and glass transition point (Tg), ignition point, water absorption rate (JIS
K6911), when the loss on heating was measured, the Tg was 15
At 0℃, the ignition point is 140℃, and the water absorption rate is 0.05% (24
time), and the loss on heating was 2.3%.

Here, the method for measuring the ignition point is as follows.

A part of the material for processing is sampled, frozen and crushed, and
0 mesh or less fine powder on an aluminum plate
mg was taken, and the ignition point was measured using a high-pressure differential thermal analyzer. The measurement conditions were an oxygen pressure of 10 kg/crd and a temperature increase rate of 20°C/min.

Next, the round bar block material was cut using a lathe to produce a resin roll.

The lathe (LEO-100 (A) type manufactured by Washino Kikai ■) has a rotation speed of 750 times/min, a feed rate of 0.025 mm/RPM,
A cutting tool (G2 3
2-4 type) cutting was performed. The shape of the resin roll was 90 mm in outer diameter and 800 mm in length. Regarding cutting processing,
When evaluating the ignitability, machinability, and finished state of the molded product, it was found that there was no ignition during cutting, and it was possible to cut smoothly without melting due to frictional heat, and no odor was generated during cutting. The finished surface of the molded product was good and glossy. Furthermore, the molded product had a low water absorption rate and good dimensional stability.

By the way, the commercially available cutting material polycarbonate (
When cutting PC) or ultra-high molecular weight polyethylene (PE) in the same way, the material itself and cutting waste melted, and a smooth, glossy finish was not obtained.

A round bar-shaped block material was obtained in the same manner as in Example 3, except that the antioxidant Irganox 259 was not used, and a resin roll was created by cutting in the same manner. It is shown in Table 3.

A round rod-shaped block material was obtained in the same manner as in Example 3 using the monomer composition shown in Table 3. Table 3 shows the physical properties, machinability, and finished state of the blocks obtained in Examples 3 to 5. For comparison, commercially available polycarbonate (
PC) and ultra-high molecular weight polyethylene (PE) were evaluated for machinability, and the results are shown in Table 3.

As is clear from Table 3, the cut molded product of the present invention has T
It can be seen that it has a high g value and excellent heat resistance, a low water absorption rate, and a low specific gravity and is lightweight. Furthermore, it has a high ignition point, and has good machinability and finished condition.

(Leaving space below) Table 3 *-1 No ignition ○, ignition × *-2 Molten metal (no ○, melts immediately after cutting starts ×, begins to melt over time after cutting starts △ *-3 No odor occurs ○, Odor generation × * - 4 Visually shiny ○, visually slightly shiny △, visually not shiny × *
-5 No discoloration O11 amount Blackening x, Partial blackening △ * -6 Cutting waste material 312 with a thickness of about 0.020 mm was collected in a polyethylene bucket, stored in a greenhouse at 40°C, and checked for spontaneous combustion.

*-7 Approximately 80% asymmetric trimer and 20% symmetric trimer
A mixture of.

(The following is a blank space) As shown in Table 4, a round bar-shaped block material was obtained in the same manner as in Example 3 except for changing the type and blending ratio of the antioxidant, and further Examples A resin roll was created in the same manner as in 3.

Obtained. The ignition point of the 70 Tsuku wood is as shown in Table 4, and no spontaneous combustion of cutting waste was observed.

In addition, almost the same results as Example 3 were obtained regarding machinability and finished product.

In addition, in Table 4, the antioxidants used are as follows.

■-1: Phenolic antioxidant manufactured by Ciba Geigy ■-2 = Phenolic antioxidant manufactured by Kawaro Chemical Co., Ltd. ■-3: Phenolic antioxidant manufactured by Ethyl Corporation ■-4: Phenol manufactured by Ciba Geigy Antioxidant [phase] -5 Phosphorous antioxidant tri(nonylphenyl)phosphite manufactured by Nikawaguchi Chemical Co., Ltd. -6 = Seiko Chemical (
Amine-based antioxidant di-alkyl-diphenylamine manufactured by Co., Ltd. (blank below) Table 4
Using a 0% monomer mixture, srs (
A round bar-shaped block material was obtained in the same manner as in Example 3, except that 1% of Finhook 3420 (manufactured by Nippon Zeon Co., Ltd.) was added. The Tg of this block material was 187°C.

Using the material for cutting thus obtained, a comparison was made regarding machinability with a material made of stainless steel SUS 304.

Table 5 shows cutting conditions and machinability evaluation.

As is clear from Table 5, the material for cutting of the present invention can be cut with almost the same accuracy as stainless steel, and has excellent machinability.

Table 5 $I A: Pitch 5.7/100, Number of revolutions 1
00Orpm, cutting thickness 1ffiIIIB: pitch 5.
7/100, rotation speed 75Orpm, cutting thickness 4nm
C nitrile diameter φ1Gmm, rotation speed 25Orpm, depth 50s+.

*2 Effect of the invention that prevents cutting due to too much load The present invention makes it possible to obtain a thermosetting material for cutting that has low water absorption (and good dimensional stability). Molded products can be produced without coloring or deformation during cutting, and without the risk of ignition of cutting debris during cutting.In addition, the cutting material of the present invention has excellent machinability. In addition, it is lightweight and has excellent heat resistance.Furthermore, in the present invention, since the RIM method is used, large-sized molded products can be manufactured.

As described above, the material for cutting and the cut molded product of the present invention were able to exhibit superior effects compared to conventional products.

Claims (2)

[Claims] (1) The ignition point obtained by bulk ring-opening polymerization of tricyclic or higher norbornene monomers in the presence of an antioxidant is 120.
℃ or higher, and has a glass transition temperature of 80℃ or higher and is substantially free of pores and is a thermosetting material for cutting. (2) A cut-molded product obtained by cutting the thermosetting material for cutting according to claim 1.