JPH0459821A - 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] [Industrial application field]

The present invention relates to cutting materials and cutting molded products made of thermosetting norbornene-based polymers, and more specifically, the present invention relates to cutting materials and cutting molded products made of thermosetting norbornene-based polymers, and more specifically, to cutting materials and cutting molded products that are homogeneous and have excellent machinability, sliding properties, impact resistance, dimensional stability, etc. Regarding processing materials and cutting molded products. [Prior Art] Conventionally, materials for processing ( It is a well-known technique to create various mechanical parts by making round bars, plates, tubes, sheets, etc., and then performing machining such as cutting in the same way as with metals. However, although conventional cutting materials made of engineering plastics generally have excellent heat resistance and mechanical strength, they are thermoplastic resins, so the frictional heat generated during cutting reduces the temperature to near the melting point. These engineering plastics had the disadvantage that the cutting surface had to be cooled because it was difficult to obtain a smooth surface by melting or causing a fusion phenomenon on the cut surface. Since the parts are generally small, the ends (edges) may be chipped during cutting.Furthermore, since the material for cutting is generally made by injection molding, it is difficult to make large parts, and the mold is too large. There are molding restrictions that make it expensive. Among the conventional methods, so-called cast nylon resin is
Monomer is directly poured into a mold for polymerization and molding.
Compared to injection molding or extrusion molding, it has the advantage of being able to produce large products, but because it has poor water absorption resistance, it has insufficient dimensional stability, which is an extremely important performance for cutting materials. The present inventors have discovered that bulk ring-opening polymers of polycyclic norbornene monomers such as dicyclopentadiene and cyclopentadiene trimer are useful as new materials that can improve the drawbacks of the prior art. (Unexamined Japanese Patent Publication No. 1-1
58030, JP-A-1-158031). Since this material is thermosetting, it is easier to cut than conventional thermoplastic resins, and is also lightweight and has excellent heat resistance and dimensional stability. However, when cutting, this material may cause the edges to chip (chipping) or scatter cutting powder, which may worsen the working environment.Furthermore, when used as a sliding member for gears, the material has poor sliding properties. However, there was a problem that the impact resistance of the material was not sufficient. Therefore, the present inventors conducted further research and conducted block ring-opening polymerization of a polycyclic norbornene monomer in the presence of an antioxidant, a butadiene elastomer, a sliding agent, etc., thereby improving machinability and sliding properties. It has been found that a cutting material with excellent properties such as hardness, impact resistance, and dimensional stability can be obtained (Japanese Patent Application No. 1-51969). However, as a sliding agent,
When a large amount of solids insoluble in norbornene monomers, such as molybdenum disulfide, graphite, tetrafluoroethylene resin powder, or graphite, is used, uniform dispersion is difficult, and the reaction stock solution has a low viscosity. During the polymerization operation, the distribution of the sliding agent tends to be non-uniform, and as a result it is difficult to obtain highly homogeneous machining materials. [Problems to be Solved by the Invention] The object of the present invention is to provide a cutting process using a polycyclic norbornene polymer that is homogeneous and has excellent machinability, sliding properties, impact resistance, dimensional stability, etc. The purpose is to provide materials. As a result of intensive research to solve these problems when using polycyclic norbornene-based polymers, the present inventors found that polycyclic norbornene-based monomers can be used in the presence of antioxidants, butadiene-based elastomers, and sliding agents. If a liquid sliding agent or a sliding agent soluble in the norbornene monomer is used as a sliding agent during bulk ring-opening polymerization, a homogeneous polymer can be obtained. It was discovered that this material can be used as a cutting material with excellent machinability, sliding properties, impact resistance, dimensional stability, etc., and based on this knowledge, the present invention was completed.

[Means to solve the problem]

Thus, according to the present invention, a tricyclic or higher norbornene monomer is subjected to bulk ring-opening polymerization in the presence of an antioxidant, a butadiene elastomer, a liquid sliding agent, and/or a monomer-soluble sliding agent. The ignition point obtained is 120
℃ or more, glass transition temperature is 80℃ or more, coefficient of dynamic friction is 0
．． A substantially porosity-free thermosetting cutting material having an Izot impact value of 2 or less and 5 kg-cm/cm or more is provided. Further, according to the present invention, there is provided a cut molded product obtained by cutting this thermosetting material for cutting. 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 tricyclic or higher types 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.), alkenyl substituted products (e.g., vinyl, isopropenyl substituted products, etc.), alkylidene substituted products (e.g., vinyl, isopropenyl substituted products, etc.),
Examples include ethylidene substituents), aryl substituents (for example, phenyl, tolyl, naphthyl substituents, etc.), ester groups, ether groups, cyano groups, and substituents having polar groups such as halogen atoms. 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 tricyclopentadiene 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-vinyl-2-norbornene, 5-norbornene, 5-methyl-2-norbornene, 5-ethylidene-2-norbornene, 5-ethylidene-2-norbornene, 5-ethylidene-2-norbornene, 5-ethylidene-2-norbornene, 5-ethylidene-2-norbornene, 5-ethylidene-2-norbornene, 5-ethylidene-2-norbornene, 5-ethylidene-2-norbornene, etc. -Phenyl-
Bicyclic norbornene-based monomers such as 2-norbornene, or monocyclic cycloolefins such as cyclobutene, cyclopentene, cyclod-pentadiene, cyclooctene, and cyclododecene can be used in combination without impairing the purpose of the present invention. (Metathesis Catalyst System) The catalyst used in the bulk ring-opening polymerization of norbornene-based monomers in the present invention may be any metathesis catalyst system known as a catalyst for bulk ring-opening polymerization of norbornene-based monomers (for example, JP-A-58 -127728, 58-1
No. 29013, No. 59-51911, No. 60-790
No. 35, No. 60-186511, No. 61-12611
No. 5, etc.), there are no particular restrictions. Metathesis catalyst systems typically consist of a metathesis catalyst and an activator (cocatalyst). Specific examples of metathesis catalysts include halides, oxyhalides, oxides, organic ammonium salts, etc. of tungsten, molybdenum, tantalum, etc. Specific examples of activators include alkyl aluminum halides, alkoxyalkylaluminum halides, etc. Examples include halides, aryloxyalkyl aluminum halides, and organic tin compounds. Among the metathesis catalysts, it is preferable to use a catalyst that is soluble in the norbornene monomer used in the reaction.
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. Among active IFIJs, alkoxyalkylaluminum halides and aryloxyalkylaluminum halides have an appropriate pot life at room temperature even when mixed with catalyst components, so they are advantageous in operation (for example, JP-A No. 59-51911) ). In the case of alkylaluminum halides, there is a problem that polymerization starts immediately when a catalyst is mixed, but in that case, an activator and a regulator such as ethers, esters, ketones, nitriles, alcohols, etc. are used in combination. The initiation of polymerization can be delayed by
No. 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. is 3
It is better to use one with a duration of 0 minutes or longer. 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 (Japanese Patent Application Laid-Open No. 186730/1986). The amount of the metathesis catalyst is usually about 0.01 to 50 mmol, preferably 0.1 mmol per mol of norbornene monomer.
It is used in the range of ~10 mmol. The activator is generally used in an amount of 0.1 to 200 (molar ratio), preferably 2 to 10 (molar 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% or more, preferably 1 to 3% by weight relative to 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-o-tolyluethylenediamine, alkylated diphenylamine, etc. As these antioxidants, various commercially available products can be used in addition to those mentioned above. The antioxidant may be one that can be copolymerized with Shitsummer, 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). (Butadiene elastomer) The butadiene-based elastomer used in the present invention is a homopolymer of 1,3-butadiene or a copolymer mainly composed of 1,3-butadiene.
4 polybutadiene, low cis-1,4 polybutadiene, high vinyl polybutadiene, styrene-butadiene random copolymer, styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, styrene-butadiene-styrene -butadiene block copolymers, etc. The blending ratio of these butadiene-based elastomers may be appropriately selected depending on the purpose, but is usually 1 to 10% by weight, preferably 3 to 8% by weight based on the norbornene-based polymer.
It is. If this blending ratio is less than 1% by weight, the Izot impact strength of the resulting thermosetting cutting material will be 5K.
g, cm/cm, the impact resistance becomes insufficient, and the viscosity of the compounded liquid containing the norbornene monomer becomes as low as less than 100 centivoice, making it easy for the solid sliding agent to settle. On the other hand, if it exceeds 10% by weight, the viscosity of the compounded liquid will become too high, which will be disadvantageous in casting operations, and since the elastomer is thermoplastic, the obtained thermosetting material for cutting will soften during cutting. Show trends. (Sliding agent) The sliding agent used in the present invention is liquid or monomer-soluble. Specific examples of sliding agents include silicone oil, silicone craft polyethylene, and liquid paraffin. Examples include wax. These may be used alone or in combination of two or more. The mixing ratio of the liquid sliding agent and/or the monomer-soluble sliding agent is usually 1.0 to the norbornene polymer.
It is 1 to 20% by weight, preferably 0.5 to 10% by weight. If this blending ratio is too small, the effect of improving the sliding properties will be small, and if it is too large, it will adversely affect the physical properties of the cutting material. These liquid or monomer-soluble sliding agents are mixed with the norbornene monomer, and are dissolved and uniformly dispersed under heating if necessary. In addition, a powder or short fibrous sliding agent may be used in combination as long as the object of the present invention is not impaired. Specific examples of such sliding agents include graphite, carbon black, molybdenum disulfide, mica, tetrafluoroethylene resin, tetrafluoroethylene/propylene copolymer, and tetrafluoroethylene resin treatment. Examples include glass fibers treated with polytetrafluoroethylene resin, graphite treated with tetrafluoroethylene resin, polyethylene, polypropylene, polyethylene wax, polypropylene wax, silicone craft polyethylene, and silicone microcapsules. When a powder or short fiber sliding agent is used in combination, the blending ratio is usually 20% by weight or less, preferably 15% by weight or less, and more preferably 10% by weight or less. The lower limit is
Usually, it is 0.1% by weight or more, preferably 1% by weight or more. When used in combination with a liquid and/or monomer-soluble sliding agent, the problem of non-uniformity that occurs when these powder or short fiber sliding agents are used alone is eliminated or reduced. In addition, when using a powder or short fiber sliding agent together,
In order to uniformly disperse the sliding agent in the reaction liquid, the raw material monomer and the sliding agent are mixed in advance at a ratio (weight ratio) of about 1=1 to about 2=1, and uniformly dispersed using a homogenizer or the like. Alternatively, a dispersion containing a highly concentrated sliding agent may be prepared and used as the mother liquor. (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, a butadiene elastomer, and a sliding agent. 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. A preferred method for producing the processing material involves dividing the norbornene-based monomer into two separate containers, adding the metathesis catalyst to one and the activator to the other, creating two stable reaction solutions. . 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 is added to both sides.In order to prevent so-called voids from forming in the cured product (cutting material), the mold temperature should be such that the maximum curing exothermic temperature of the reactant does not exceed 180℃. It is preferable to control the cooling so that the temperature is higher than that. If the temperature is higher than that, it is necessary to take measures such as slowly cooling the cured product. There are no particular restrictions on the injection pressure, but it is usually 10 kg/C or less. This is sufficient. Also, the polymerization time may be selected as appropriate, but is usually about 2 minutes to 1 hour. The components used in the polymerization reaction must be stored and operated under an inert gas atmosphere such as nitrogen gas. is preferable, and the mold may be sealed with an inert gas, but it is not necessary. (Optional components) Various additives such as fillers, pigments, colorants, polymer modifiers, flame retardants, etc. The properties of the cutting material of the present invention can be modified by adding additives.Additives are used by being mixed in advance with either or both of the reaction solutions.Fillers include glass and carbon black. There are inorganic fillers such as , talc, calcium carbonate, and mica. (Properties of the 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, and sheet shapes. In addition, it can be a three-dimensional shaped object with a predetermined shape.The object is of high quality with substantially no holes, and has a small diameter or thickness (both 20 mm or more, preferably 20 mm or more). Since we use the zero-reaction injection molding method, which has a part of 50 mm or more, it can be easily made larger, and if we take a round bar as an example, it can be about 300 mm in diameter, or even It is possible to manufacture even larger pores. Here, the pores are those that can be identified when the cut surface is visually observed, and have a diameter of approximately 0.1 mm or more. Not having a practical pore size means that when the material for processing is cut at 100 mm intervals, there are no pores in any cross section.
It can also be detected by sending 5-10 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 freeze-pulverized and passed through a 100-mesh wire mesh, using 10 m'g), The point at which the temperature rises is defined as the ignition point.) is 120°C or higher, preferably 130°C or higher. If the ignition point is low, discoloration may occur due to carbonization during cutting, and the cut portion may become oxidized (also, it may cause spontaneous combustion if the cutting waste is left in direct sunlight or at high temperatures. The cutting material of the present invention has a dynamic friction coefficient of 0.2 or less,
It is preferably 0.18 or less, and the Izod impact value is 5.
kg-Cm/Cm or more, preferably 7 kg-Cm/Cm
That's all. Further, it is desirable that it substantially not contain unreacted norbornene monomers or volatile solvents. These volatile components volatilize during cutting and cause odor in the molded product after cutting, which worsens the working environment. In this sense, in the thermobalance method (approximately 10 mg of polymer and a plate sample with a diameter of 3 to 4 mm), the loss on heating at 400°C under a nitrogen atmosphere at a heating rate of 20°C/min was 5 weight. % or less, particularly preferably 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 1.2 or less, making it extremely lightweight even among plastics. Furthermore, the cutting material of the present invention has excellent homogeneity because it uses a liquid sliding agent and/or a monomer-soluble sliding agent. (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,
Examples include various parts such as racks, cams, shafts, levers, bearings, pulleys, drive gears, rollers, flanges, wheels, wear parts, liners, packets, washers, sliding plates, etc., and these cutting molded products are It is used in a wide range of fields, including ironwork and metal machinery, civil engineering and construction machinery, textile industry machinery, transport and conveyance machinery, food processing machinery, and other general machinery. [Examples] The present invention will be explained in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples. Note that parts, percentages, etc. Unless otherwise specified, the values are based on weight. [Example 1] For 100 parts of a mixture of 75% dicyclopentadiene (DCP) and 25% cyclopentadiene trimer (CP trimer; a mixture of 80% asymmetrical and 20% symmetrical),
Styrene-butadiene-styrene block copolymer (S
BS: manufactured by Asahi Kasei Co., Ltd., Toughbrain A) 3.5 parts, high cis-
1,4 polybutadiene (manufactured by Nippon Zeon Co., Ltd., BR-122
0) 0.5 part, 2 parts of phenolic antioxidant (manufactured by Ciba Geigy, Irganox 1010), and silicone oil (manufactured by Toray Silicon, 5H-200) as a sliding agent.
) and silicone craft polyethylene (manufactured by Dow Corning, 5P-300) were added in the proportions shown in Table 1, and heated to 100° C. to obtain a solution in which each component was dissolved. After cooling this liquid, it was placed in two containers, one containing diethylaluminum chloride (DEAC) for the monomer.
) was added at a concentration of 33 mmol, n-propanol at a concentration of 42.9 mmol, and silicon tetrachloride at a concentration of 20 mmol. On the other hand, tri(tridecyl)ammonium molybdate was added to the seven-layer mixture at a concentration of 4 mmol. Both reaction solutions were kept at 25°C (pot life approximately 10 minutes).
Mixed at a ratio of 1:1 using a gear pump and a power mixer, and has an inner diameter of 75 mmφ and a height of 800 mm.
The water was poured into a jacketed steel mold which was kept at a temperature of 18°C. After injection, curing begins approximately 20 minutes and then 15 minutes.
After a few minutes, the formwork was removed to obtain a round bar-shaped 9 processing material (round bar block material) of 75 mm φ x 800 mm. These series of operations were performed under a nitrogen atmosphere. The physical properties, machinability, and finished product of the material for processing thus obtained were investigated. The results are shown in Table 1.The ignition points of the present invention were all 120°C or higher. Here, the methods for measuring and evaluating each physical property are as follows. LL Skin 51: The presence or absence of holes with a diameter of 0.1 mm or more was observed on the cut surfaces of the processing material cut at 100 mm intervals, and the case where there were no holes in any cross section was rated O. L plate 1u: The above cut surface was observed, and the color was uneven (if the appearance was uniform, it was marked as ○, and if the sliding agent had aggregated and the color was uneven, it was marked as ×). 1. Chipping: Processing As shown in the cross-sectional view in Figure 1, the material for use was cut into a step shape with a width of 50 mm and a height of 5 mm, and the presence or absence of chips at the edges was observed. ×, and those with some chipping are designated as Δ. Upper part of the machining material: O1 indicates that no cutting powder is generated when cutting the material. Items that are unfavorable in terms of the working environment are marked as ×. !Himi = A part of the material for processing was sampled, frozen and crushed, and 10 mg of the fine powder of 100 mesh or less was placed on an aluminum plate and heated under high-pressure differential heat. Measured by an analyzer,
The point where the differential heat curve showed a sharp rise was defined as the ignition point. Measurement conditions were oxygen pressure 10Kg/crrr, temperature increase rate 2
0"C/min. Rainbow Ju! ball, fi: Measured according to JIS K7125. Counting material, 5LIS304, speed, 100mm/
load: 2030 g (blank below) As is clear from Table 1, when a butadiene-based elastomer is used as the elastomer and a liquid sliding agent and/or a monomer-soluble sliding agent is used, chipping and cutting powder are scattered. to avoid deteriorating the working environment (and
The processing material has excellent impact resistance and sliding properties. [Example 2] The same procedure was carried out except that 1 part of silicone oil and 4 parts of tetrafluoroethylene resin powder (Daikin Co., Ltd., Lubron L-5) were added as a sliding agent to prepare a monomer dispersion. A material for cutting was prepared in the same manner as in Example 1. The cutting material thus obtained has an ignition point of 1
At 20° C. or higher, evaluations of the presence of pores, cross-sectional appearance, chipping during cutting, and generation of cutting powder were all O. In addition, Tg is 169℃, Izotsu impact strength is 10.5
kg-cm/cm, and the coefficient of dynamic friction was 0.14. [Comparative Example 1] When a material for cutting was prepared in the same manner as in Example 2 except that silicone oil was not used, color unevenness was observed in the circumferential portion in the cross-sectional appearance. [Effects of the Invention] The cutting material of the present invention is homogeneous, lightweight, and has excellent heat resistance and dimensional stability, as well as improved sliding properties and impact resistance. Edges are not damaged and scattering of cutting powder is also less likely.

[Brief explanation of drawings]

Figure 1 shows the steps taken to check for chipping during cutting.
FIG. 3 is a cross-sectional view of the cutting material when it is cut into a stepwise shape.

Claims (2)

[Claims] (1) Ignition point obtained by bulk ring-opening polymerization of a tricyclic or larger norbornene monomer in the presence of an antioxidant, a butadiene elastomer, a liquid sliding agent, and/or a monomer-soluble sliding agent. 120° C. or higher, a glass transition temperature of 80° C. or higher, a dynamic friction coefficient of 0.2 or lower, and an Izod impact value of 5 kg·cm/cm 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.