JP2016204566A - Material for disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material for a disc brake having long life by avoiding cracks or breakages.SOLUTION: The material for a disc brake is provided that contains 15 pts.wt. to 150 pts.wt. of carbon fiber, 15 pts.wt. to 150 pts.wt. of coal tar, 2 pts.wt. to 30 pts.wt. of graphite, 80 pts.wt. to 600 pts.wt. of aluminum titanate-based ceramic sintered powder and 100 pts.wt. of a polymer resin.SELECTED DRAWING: None

Description

  The present invention relates to a material for a disc brake. The disc brake is a mechanism that generates a frictional force by pressing a brake rotor that rotates together with wheels from both sides with a brake pad incorporated in a brake caliper, and converts kinetic energy into heat energy for braking. The structure that transmits the force to press the pad is mostly a hydraulic type that uses a Pascal principle to operate the piston with the input from the master cylinder for automobiles, and the rail vehicle has a pneumatic type that presses the pad by air pressure. . This disc brake is used in bicycles, automobiles, vehicles (including special vehicles), railway vehicles, Shinkansen / high-speed railway vehicles, linear motor cars, space aircraft, flying objects, high-rise building elevators, wind power generation, machine tools, etc. Yes. The material of this disc brake includes organic materials, inorganic materials and composites thereof, metallic materials, etc., but the material for disc brakes of the present invention is nanocarbon fibers, chopped carbon fibers (PAN-based, pitch-based), especially chops. Carbon fiber, coal tar, graphite, aluminum titanate ceramic sintered powder, and polymer resin are contained.

There are various types of carbon ceramic disc brakes, most of which are made of a composite material of SiC and carbon (hereinafter referred to as C / C composite material) as a ceramic material. Yes. Since SiC has a larger coefficient of linear expansion ^{(4~5 × 10 -6 / K)} , the difference between the small carbon coefficient of linear expansion (1 × ¹⁰ -6 / K) larger, rotor and pad when applying the brake The temperature difference between SiC and the carbon material further increases due to frictional heat and the like. Further, when chattering occurs between the rotor and the pad, a locally overheated portion and a low temperature portion are formed, and a thermal shock state is generated, so that cracking and breakage are likely to occur. Furthermore, the SiC system has a good affinity with water, snow, and a snow melting agent, and is liable to be cracked or damaged due to swelling due to moisture absorption, resulting in a short life.

  Also, the heat resistance of the C / C composite material is good, but if moisture is absorbed, hydrocarbons may be formed and voids may be formed, which may swell due to frictional heat between the rotor and the pad when the brake is applied. Prone to cracking and breakage. (See Non-Patent Document 1)

"Development of C / C composite disc brake for high-speed Shinkansen" Mitsubishi Heavy Industries Technical Review Vol.34 No.6 (1997-11)

  When the disc brake is operated, frictional heat is generated, and the contact pressure portion between the rotor and the pad is partially rapidly heated. In particular, when the vehicle is stopped during ultra-high-speed traveling such as F-1, the temperature becomes extremely high. The life of the disc brake is determined by the length of time at which the temperature is extremely high, the cumulative number of stops, and the total time from the running state to the stop, that is, the frequency of use of the brake. However, SiC disk brakes that have been used in the past have not been able to ensure a sufficiently long life.

As a result of many years of research, the present inventor has found that the main causes of cracks and breakage of disc brakes are the difference in linear expansion coefficient between SiC and carbon material, and the temperature at the contact and non-contact points of the rotor and pad. It was considered that the disc brake was swollen by brake friction heat due to the spalling due to the difference and the thermochemical reaction by the snow melting agent (CaCl ₂ ) and the absorption of water such as water and snow.

  The present invention has been made in view of the problems of such a conventional disc brake, and an object thereof is to provide a disc brake material having a long life while avoiding cracks and breakage. And

  In order to solve the above problems, the present invention has the following configuration. The disc brake includes a brake caliper, a brake pad, and a brake rotor as main components, and the present invention is suitable as a material for these disc brakes.

  The material for disc brakes of the present invention contains carbon fiber, coal tar, graphite, aluminum titanate ceramic sintered powder, and a polymer resin.

  The carbon fiber is preferably contained in an amount of 15 to 150 parts by weight with respect to 100 parts by weight of the polymer resin. When the amount of carbon fiber is less than the above, the strength of the disc brake is low, and when the amount of carbon fiber is more than the above, it is difficult to form the disc brake. In this respect, the carbon fiber is more preferably contained in an amount of 15 to 50 parts by weight with respect to 100 parts by weight of the polymer resin.

  The coal tar is preferably contained in an amount of 15 to 150 parts by weight with respect to 100 parts by weight of the polymer resin. When the amount of coal tar is smaller than the above, the lubricating performance is deteriorated, and when the amount of coal tar is larger than the above, it becomes difficult to form a disc brake. In this respect, the amount of coal tar is more preferably 15 to 50 parts by weight with respect to 100 parts by weight of the polymer resin.

  It is preferable to contain 2 to 30 parts by weight of graphite with respect to 100 parts by weight of the polymer resin. When the amount of graphite is less than the above, the lubricating performance is lowered, and when the amount of graphite is more than the above, it becomes difficult to form a disc brake. In this respect, the amount of graphite is more preferably 5 to 25 parts by weight with respect to 100 parts by weight of the polymer resin.

  The aluminum titanate-based ceramic sintered powder is preferably contained in an amount of 80 to 600 parts by weight with respect to 100 parts by weight of the polymer resin. If the amount of aluminum titanate ceramic sintered powder is less than the above, the strength of the disc brake will be low, and if the amount of aluminum titanate ceramic sintered powder is greater than the above, molding to the disc brake will be impossible. It becomes difficult. In this respect, the aluminum titanate-based ceramic sintered powder is more preferably contained in an amount of 100 parts by weight to 400 parts by weight with respect to 100 parts by weight of the polymer resin.

  The material for disc brakes of the present invention comprises 15 to 150 parts by weight of carbon fiber, 15 to 150 parts by weight of coal tar, 2 to 30 parts by weight of graphite, and 80 parts by weight. More than 600 parts by weight of aluminum titanate ceramic sintered powder and 100 parts by weight of polymer resin are contained.

The disc brake material of the present invention can contain rubber as a damping material, a metal oxide as an abrasive, an alkaline substance such as slaked lime, a filler, etc. as a pH adjuster, if necessary.

  The disc brake material of the present invention contains carbon fiber and an aluminum titanate ceramic sintered powder in appropriate amounts as components for imparting necessary strength, and coal tar as a component for imparting necessary lubrication performance. Is contained in an appropriate amount, so it is difficult to wear and cracks and breakage are less likely to occur. Moreover, there exists an effect which prevents mixing of the air in the kneading | mixing in the manufacturing process which causes a void, and a stirring process.

FIG. 1 is a schematic diagram showing a method of a high-speed friction test. FIG. 2 is a diagram showing the pressing position of the block test piece against the disk used in the high-speed friction test.

The form for carrying out the present invention is as follows.
<< Form 1 of Disc Brake Material of the Present Invention >>
An appropriate amount of coal tar, an appropriate amount of graphite, and an appropriate amount of aluminum titanate-based ceramic sintered powder for a sheet formed by opening a bundle of carbon fibers formed by aligning carbon fibers in one direction. Then, a kneaded product obtained by kneading an appropriate amount of a polymerized resin and an appropriate amount of an additive including a curing agent is applied, heated and dried to obtain a prepreg sheet, and the orientation directions of the carbon fibers in the prepreg sheets contacting with each other are different. In this way, a plurality of prepreg sheets are laminated, and a hot-press process, a HIP process or a CIP process is performed to obtain a molded product.

<< Form 2 of Disc Brake Material of the Present Invention >>
An appropriate amount of carbon fiber, an appropriate amount of coal tar, an appropriate amount of graphite, an appropriate amount of aluminum titanate ceramic sintered powder, an appropriate amount of polymerized resin, and an appropriate amount of additives including a curing agent were kneaded. The kneaded product is applied, heated and dried to obtain a prepreg sheet, and then subjected to hot press processing, HIP processing or CIP processing to obtain a molded product.

<< Form 3 of Disc Brake Material of the Present Invention >>
The molded product produced in Aspect 2 is sandwiched between the prepreg sheet laminates produced in Aspect 1 and subjected to hot pressing, HIP processing or CIP processing to obtain a molded product.

<Sintered aluminum titanate ceramic powder>
The aluminum titanate ceramic includes a Ti-containing material, an Al-containing material, a Li-containing material, and a Mg-containing material.

<Ti-containing material>
The Ti-containing material used in the present invention contains titanium, and is preferably a titanium oxide powder. As the titanium oxide, anatase type and / or rutile type titanium oxide can be used. Specifically, a rutile type titanium oxide produced by a chlorine method and an anatase type titanium oxide produced by a sulfuric acid method can be used. Furthermore, as the Ti-containing material, a material that changes to titanium oxide when fired in air can be used. Examples of such materials include titanium salts, titanium alkoxides, titanium hydroxide, titanium nitride, titanium sulfide, and metal titanium.

<Al-containing material>
The Al-containing material used in the present invention contains aluminum, preferably alumina (aluminum oxide) powder. Examples of the crystal type of alumina include γ type, δ type, θ type, and α type, and may be amorphous. α-type alumina is preferably used. Furthermore, examples of the Al-containing material include an aluminum salt, aluminum alkoxide, aluminum hydroxide, and metal aluminum. When anatase type and / or rutile type titanium oxide is used as the Ti-containing material and easy-sintering alumina α-type is used as the Al-containing material, the reactivity of both components is good, and titanium is obtained in a high yield in a short time. Aluminum oxide can be produced.

The compounding ratio of the Ti-containing material and the Al-containing material is preferably 75 to 25 parts by weight of the Al-containing material with respect to 25 to 75 parts by weight of the Ti-containing material. More preferably, 70 to 30 parts by weight of an Al-containing material is blended with 30 to 70 parts by weight of the Ti-containing material. More preferably, 60 to 40 parts by weight of an Al-containing material is added to 40 to 60 parts by weight of the Ti-containing material. The weight of the Ti-containing material is a weight converted to titanium oxide (TiO ₂ ), and the weight of the Al-containing material is a weight converted to alumina (Al ₂ O ₃ ). When using a Ti-containing material other than titanium oxide, the weight of the titanium oxide containing the same amount of Ti as the Ti-containing material is the weight of the Ti-containing material, and when using an Al-containing material other than alumina, the Al-containing material The weight of the alumina containing the same amount of Al is the weight of the Al-containing material.
When the Ti-containing material is less than 25 parts by weight (when the Al-containing material is more than 75 parts by weight), the mechanical strength increases, but the linear expansion coefficient also increases. When the Ti-containing material is more than 75 parts by weight (when the Al-containing material is less than 25 parts by weight), the mechanical strength is lowered and the thermal stability is deteriorated.

<Li-containing material>
Examples of the Li-containing material used in the present invention include petalite, spodumene, lithium carbonate, and lithium oxide, and preferably contain Li and Al, and contain Li, Al, and Si (Li and Al). A silicate containing Al) is more preferable. When the Li-containing material in the form of silicate is used, when an aluminum titanate-based fired body is formed by firing, a part of Si in the Li-containing material is dissolved in the crystal lattice and is replaced with Al. Since Si has an ion radius smaller than that of Al, the distance from surrounding oxygen atoms is shortened, and the lattice constant (axial length) is smaller than that of pure aluminum titanate. As a result, the obtained sintered body has a stabilized crystal structure, improved mechanical strength, and improved thermal stability.

When the total of the Ti-containing material and the Al-containing material is 100 parts by weight, the Li-containing material is preferably 1 to 10 parts by weight, more preferably 3 to 6 parts by weight, and 4 to 5 parts by weight. Most preferably. An aluminum titanate system in which the Li-containing material is 1 to 10 parts by weight with respect to a total of 100 parts by weight of the Ti-containing material and the Al-containing material, thereby sufficiently reducing the linear expansion coefficient and reducing the volume change due to heat A sintered body can be obtained. When the Li-containing material is less than 1 part by weight with respect to 100 parts by weight of the total of the Ti-containing material and the Al-containing material, the linear expansion coefficient of the aluminum titanate-based sintered body cannot be sufficiently reduced. On the other hand, when the Li-containing material is more than 10 parts by weight with respect to 100 parts by weight of the total of the Ti-containing material and the Al-containing material, the heat resistance and mechanical strength of the aluminum titanate-based sintered body are lowered. The weight of the Li-containing material is a weight converted to petalite (Li (AlSi ₄ O ₁₀ )). When a Li-containing material other than petalite is used as the Li-containing material, the weight of the petalite containing the same amount of Li as the Li-containing material is defined as the weight of the Li-containing material. When a Li-containing material containing Li and Al in its components is used as the Li-containing material, such as petalite, the Li-containing material is both an Li-containing material and an Al-containing material. That is, it is assumed that petalite is both an Li-containing material and an Al-containing material, and the petalite contains alumina containing the same amount of Al as the amount of Al in the petalite (Al-containing material).

<Mg-containing material>
The Mg-containing material used in the present invention contains magnesium, for example, magnesium oxide. In addition, substances that change into magnesium oxide by firing in air, such as magnesium salts, magnesium alkoxides, magnesium hydroxide, magnesium nitride, and magnesium metal, can also be used as the Mg-containing material in the present invention. The weight of the Mg-containing material is a weight converted to magnesium oxide (MgO). An oxide (MgAl ₂ O ₄ ) having a spinel structure can also be used as the Mg-containing material. When an Mg-containing material containing Mg and Al in its components, such as an oxide having a spinel structure, is used as the Mg-containing material, the Mg-containing material is both an Mg-containing material and an Al-containing material. That is, the magnesium oxide spinel is both an Mg-containing material and an Al-containing material, and the magnesium oxide spinel contains alumina containing the same amount of Al as the amount of Al in the magnesium oxide spinel (Al-containing material). To do. When an Mg-containing material containing Mg and Ti in its components is used as the Mg-containing material, the Mg-containing material is both a Mg-containing material and a Ti-containing material. That is, the Mg-containing material contains the same amount of magnesium oxide as the amount of Mg in the Mg-containing material, and also includes titanium oxide containing the same amount of Ti as the amount of Ti in the Mg-containing material. Suppose that

Preferred Mg-containing materials are oxides having a spinel structure, MgCO ₃ and MgO. Examples of the oxide having a spinel structure include MgAl ₂ O ₄ and MgTi ₂ O ₄ . Such an oxide having a spinel structure may be a natural mineral, and can also be obtained by firing a raw material containing MgO and Al ₂ O ₃ or a raw material containing MgO and titanium oxide.

  The Mg-containing material is preferably 1 to 10 parts by weight, and more preferably 3 to 8 parts by weight, when the total of the Ti-containing material and the Al-containing material is 100 parts by weight. Aluminum titanate system in which the linear expansion coefficient is made sufficiently small and the volume change due to heat is smaller by making the Mg-containing material 1 to 10 parts by weight with respect to 100 parts by weight of the total of Ti-containing material and Al-containing material A sintered body can be obtained. When the Mg-containing material is less than 1 part by weight with respect to 100 parts by weight of the total of the Ti-containing material and the Al-containing material, the heat resistance and mechanical strength of the aluminum titanate-based sintered body are lowered. On the other hand, if the Mg-containing material is more than 10 parts by weight relative to 100 parts by weight of the Ti-containing material and the Al-containing material, the mechanical strength of the aluminum titanate-based sintered body is lowered or the thermal expansibility is lowered. However, it may be decomposed by high heat. The weight of the Mg-containing material is a weight converted to magnesium oxide (MgO).

  Examples of Ti-containing materials, Al-containing materials, Li-containing materials, and Mg-containing materials include alumina ceramics, titania ceramics, magnesium oxide ceramics, aluminum titanate-based sintered bodies, magnesium titanate ceramics, spinel ceramics, aluminum magnesium titanate ceramics, etc. It can be suitably selected from those used as various ceramic raw materials.

Preferred raw materials for Ti-containing material, Al-containing material, Li-containing material and Mg-containing material include oxides such as Al ₂ O ₃ , TiO ₂ , LiO and MgO, MgAl ₂ O ₄ , Al ₂ TiO ₅ , Mg and Ti A composite oxide containing two or more kinds of metal components such as a spinel type structure containing, a compound containing one or more kinds of metal components selected from the group consisting of Al, Ti and Mg (carbonates, nitrates, sulfates) Etc.).

If necessary, inorganic materials other than Ti-containing materials, Al-containing materials, Li-containing materials, and Mg-containing materials can be used as additives. For example, it can be mentioned as such inorganic materials, SiO _2, iron oxide, zirconia, zircon, yttria, strontium, SiC, feldspar, barium sulfate and the like. One or more of these inorganic materials can be added in an amount of 15 parts by weight or less based on a total of 100 parts by weight of the Ti-containing material, Al-containing material, Li-containing material, and Mg-containing material. Part by weight is preferred, 4 to 10 parts by weight is more preferred, and 3 to 6 parts by weight is most preferred.

  A mixture can be obtained by mixing Ti-containing material, Al-containing material, Li-containing material and Mg-containing material. Each raw material powder can be sufficiently mixed and, if necessary, calcined to an appropriate particle size after firing. The pulverizing means is not limited, and for example, a ball mill, a medium stirring mill, or the like can be used.

  The aluminum titanate ceramic sintered powder is classified into a small diameter having a particle diameter of 1 nm to 20 μm, a medium diameter having a particle diameter of 20 μm to 100 μm, and a large diameter having a particle diameter of 100 μm to 5 mm. The blending ratio of “fine powder of small diameter aluminum titanate ceramic” to “fine powder of medium diameter aluminum titanate ceramic” vs. “fine powder of large diameter aluminum titanate ceramic” is 1 part by weight to 2 weights. Preferably 3 parts by weight. Most preferably, the particle diameter of the fine powder of the small-diameter aluminum titanate ceramic is 1 μm, the particle diameter of the fine powder of the medium-diameter aluminum titanate ceramic is 50 μm, The particle size of the fine powder is 1.2 mm.

  The raw material mixture can be fired as it is, but it is preferable to fire after forming into the final shape of the molded body. At the time of molding, a molding aid can be added to the raw material mixture. As molding aids, binders, mold release agents, antifoaming agents, peptizers, and the like can be used. Examples of the binder include polyvinyl alcohol, micro wax emulsion, methyl cellulose, carboxymethyl cellulose and the like. Examples of the release agent include stearic acid emulsion, examples of the antifoaming agent include n-octyl alcohol and octylphenoxyethanol, and examples of the peptizer include diethylamine and triethylamine. .

  The amount of the molding aid used is not limited, but any molding aid is used with respect to a total of 100 parts by weight when the Ti-containing material, Al-containing material, Li-containing material and Mg-containing material are converted as oxides as described above. The agent is preferably in the following range in terms of solid matter.

  0.2-0.6 parts by weight of binder, 0.2-0.7 parts by weight of release agent, 0.5-1.5 parts by weight of antifoaming agent, 0.5-1 of peptizer Mix 5 parts by weight.

  Examples of the molding method of the raw material mixture include press molding, sheet molding, cast molding, extrusion molding, injection molding, CIP molding (cold isostatic pressing), and HIP molding (hot isostatic pressing). A known molding method such as three-dimensional molding can be employed.

  As a means for firing the molded body, a known firing equipment such as a tubular electric furnace, a box-type electric furnace, a tunnel furnace, a far-infrared furnace, a corrugated heating furnace, a shaft furnace, a reflection furnace, a rotary furnace, a roller hearth furnace is used. can do. The baking may be a batch type or a continuous type. Moreover, stationary baking may be sufficient and fluid type baking may be sufficient.

  The atmosphere at the time of firing may be air, vacuum (degree of vacuum of 1 Pa or less), nitrogen atmosphere, reducing atmosphere, or inert atmosphere (argon, neon, helium, etc.) Is preferred.

  A calcination temperature is 1000-1750 degreeC, and 1200-1600 degreeC is preferable. There is no limitation on the firing time, and it may be fired until the sintering proceeds sufficiently, depending on the shape of the molded body, and usually it may be fired for 1 to 10 hours in the above temperature range. There are no limitations on the rate of temperature rise and the rate of temperature fall during firing as long as the sintered body does not crack.

  In order to sufficiently remove the molding aids such as moisture and binder contained in the mixture, it is preferable to gradually increase the temperature without rapidly increasing the temperature. Moreover, before heating to the said calcination temperature, as needed, it heats up slowly over 10 to 30 hours in the temperature range of 700-1000 degreeC, and performs an aluminum titanate series sintering by performing temporary sintering. Residual stress in the sintered body that causes cracks when the body is formed can be suppressed.

When the aluminum titanate ceramic is made of TiAl ₂ O ₅ as a main raw material, the aluminum titanate ceramic contains oxygen contained in TiAl ₂ O ₅ when sintered in an argon or nitrogen atmosphere at 1500 to 2000 ° C. In some cases, TiAl ₂ O ₅ disappears by reaction with TiO ₂ , Al ₂ O, CO ₂ or the like. Therefore, it is preferable that the firing temperature when the aluminum titanate-based ceramics is mainly TiAl ₂ O ₅ does not exceed 700 ° C.

The aluminum titanate-based sintered body obtained as described above can be expressed as a Ti—Al—Li—Mg—O system or a Ti—Al—Li—Mg—Si—O system as a chemical formula. The aluminum titanate-based sintered body of the present invention may contain natural products as Ti-containing materials, Al-containing materials, Li-containing materials, and Mg-containing materials. Therefore, impurities are inevitably included. Therefore, it is difficult to express the aluminum titanate-based sintered body of the present invention with an accurate chemical formula. When titanium oxide is used as the Ti-containing material, alumina is used as the Al-containing material, petalite is used as the Li-containing material, and magnesium oxide is used as the Mg-containing material, the aluminum titanate-based sintered body is ( Al ₂ O ₃ ) a (TiO ₂ ) b (MgO) c (Li (AlSi ₄ O ₁₀ )) d. Here, the values of a, b, c, and d are determined by the amount of each material used.

The aluminum titanate-based ceramic used in the present invention is super heat resistant and preferably has an ultra-low expansion. The maximum melting temperature of the aluminum titanate-based ceramic is 2000 ° C., and the linear expansion at −40 ° C. to 1350 ° C. The coefficient is preferably −0.3 × 10 ⁻⁶ / K to −1 × 10 ⁻⁶ / K.

"Carbon fiber"
The kind of carbon fiber is not limited. Pitch-based carbon fiber or PAN-based carbon fiber is preferable. The carbon fiber may be surface-treated or may not be surface-treated. The length of the carbon fiber is not limited and may be a so-called long fiber or short fiber.

Coal Tar
Coal tar is a kind of by-product obtained by carbonizing coal in a coke oven when producing coke. Naphthalene (5-15%), benzene (0.3-1%), phenol (0 0.5 to 1.5%), cresol, benzopyrene (1 to 3%), phenanthrene (3 to 8%), and the like, and the disc brake material of the present invention contains this coal tar.

"graphite"
Graphite is a hexagonal hexagonal plate-like crystal composed of carbon, and it is a layered material in the shape of a turtle shell, and the carbon is connected between the layers with strong covalent bonds in each layer. ) Is a substance bonded with a weak van der Waals force, and the disc brake material of the present invention contains this graphite.

<Polymer resin>
There is no restriction | limiting in particular in the kind of polymer resin used for this invention, Either a thermosetting resin or a thermoplastic resin can be used. In a preferred embodiment, it is a thermosetting resin or a mixture of a thermosetting resin and a thermoplastic resin.

  As the thermosetting resin, epoxy resin, phenol resin, bismaleimide resin, triazine resin, BT resin, unsaturated polyester resin, vinyl ester resin, or the like can be used.

  The epoxy resin is preferably at least one of bisphenol A (BPA) diglycidyl ether and bisphenol F (BPF) diglycidyl ether and derivatives thereof; tetraglycidyl derivative of 4,4′-diaminodiphenylmethane (TGDDM); aminophenol As well as other glycidyl ethers and glycidyl amines well known in the art.

  Examples of the thermoplastic resin include the following.

  Polyethersulfone (PES), polyphenylsulfone, polysulfone, polyester, polymerizable macrocycle (eg, cyclic butylene terephthalate), liquid crystal polymer, polyimide, polyetherimide, aramid, polyamide, polyester, polyketone, polyetheretherketone ( PEEK), polyurethane, polyurea, polyaryl ether, polyaryl sulfide, polycarbonate, polyphenylene oxide (PPO) and modified PPO, or any combination thereof.

  The above resins can be used alone or in combination. The resin may be completely impregnated into the carbon fiber or partially impregnated.

  The polymer resin used in the present invention can contain at least one curing agent and curing accelerator when the resin is a thermosetting resin.

  Suitable curing agents include dicyandiamide, anhydrides, especially polycarboxylic anhydrides, such as nadic anhydride (NA), methyl nadic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, Examples include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, or trimellitic anhydride.

  Other suitable curing agents include amines including aromatic amines such as 1,3-diaminobenzene, 1,4-diaminobenzene, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl sulfone ( There are polyaminosulfones such as 4,4′-DDS) and 3,3′-diaminodiphenylsulfone (3,3′-DDS). Various commercially available curing agents can be used. Preferred commercially available curing agents include dicyandiamide jER cure, DICY15 (manufactured by JER Co., Ltd.), 4,4′-diaminodiphenylsulfone (4,4′-DDS) and 3,3′-diaminodiphenylsulfone (3,3). 3'-DDS).

  When a curing agent is present, it can be present in the range of 60% to 1% by weight of the polymer resin. More preferably, the curing agent can be present in the range of 50 wt% to 2 wt%. Particularly preferably, the curing agent can be present in the range of 40% to 3% by weight. Two or more curing agents can be used in combination.

  The polymer resin used in the present invention can also contain a curing accelerator.

  Suitable curing accelerators include 3- (3,4-dichlorophenyl) -1,1-dimethylurea, N, N-dimethyl-N′-3,4-dichlorophenylurea (diuron), N, N-dimethyl- N'-3-chlorophenylurea (monuron), and preferably N, N- (4-methyl-m-phenylenebis [N ', N'-dimethylurea] (TDI uron). If present, it can be present in the range of 1% to 5% by weight of the polymer resin.

  The polymer resin can further contain components such as a performance enhancer or a modifier. Examples of performance enhancers or modifiers include flexibility imparting agents, reinforcing agents / particles, additional accelerators, core-shell rubbers, flame retardants, wetting agents, pigments / dyes, flame retardants, plasticizers, UV absorbers, It can be selected from antibacterial compounds, fillers, viscosity modifiers / flow control agents, tackifiers, stabilizers, water repellents, and polymerization inhibitors.

  Next, based on an Example, this invention is demonstrated concretely. However, the present invention is not limited to only these examples. Various changes and modifications can be made without departing from the technical scope of the present invention.

[Example 1]
44 parts by weight of titanium oxide (trade name “A-110” manufactured by Sakai Chemical Co., Ltd.), 56 parts by weight of easily sintered alumina (trade name “AES-11” manufactured by Sumitomo Chemical Co., Ltd.), and Fukushima 4 parts by weight of feldspar, 1.5 parts by weight of diethanolamine as a peptizer, 0.1 parts by weight of polyvinyl alcohol as an organic binder, 0.5 parts by weight of polypropylene glycol as an antifoaming agent, and an appropriate amount of water are mixed. To obtain a slurry. This slurry was dried to obtain a clinker. This clinker was pulverized with a ball mill for 24 hours and classified using a sieve having a sieve mesh of 80 to 100 μm to obtain an aluminum titanate powder having an average particle size of 90 μm. The obtained aluminum titanate powder was calcined in the air at a maximum temperature of 1370 ° C. for 3 hours and then allowed to cool to room temperature to obtain an aluminum titanate sintered clinker. This clinker is pulverized in a ball mill for 24 hours, classified using a sieve having a sieve mesh of 20 to 40 μm and a sieve having a sieve mesh of 5 to 20 μm, and an aluminum titanate sintered powder having an average particle size of 30 μm And an aluminum titanate sintered powder having an average particle diameter of 10 μm.

  60 parts by weight of the aluminum titanate-based sintered powder having an average particle diameter of 30 μm obtained as described above, 180 parts by weight of the aluminum titanate-based sintered powder having an average particle diameter of 10 μm obtained as described above, 40 parts by weight of chopped carbon fiber (PAN type, trade name “TR06AL” manufactured by Mitsubishi Rayon Co., Ltd.) having a length of 6 mm, 40 parts by weight of coal tar, and graphite (trade name “Z” manufactured by Ito Graphite Industries Co., Ltd.) -5F ”), 15 parts by weight of epoxy resin (trade name“ Ehototo YD-128 ”manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and a curing agent (trade name“ Tomite TXE- ”manufactured by T & K TOKA Corporation). 415A ") 60 parts by weight and 100 parts by weight of methanol were kneaded to obtain a kneaded product. The kneaded product was put into a 100 mm x 100 mm size mold and dried and cured at 120 ° C. 1 molded body was obtained.

《High speed friction test》
In order to investigate the wear resistance of the disc brake material of the present invention, a high-speed friction test as shown in the schematic diagram of FIG. 1 was conducted. In FIG. 1, 1 is a disk, 2 is a block test piece, 3, 3 is a load cell, 4 is a DC motor, 5 is a thermocouple, and 6 is a slip ring. FIG. 2 is a view showing the pressing position of the block test piece against the disk used in the high-speed friction test of FIG. In FIG. 2, the block test pieces 2 and 2 cut out from the molded body obtained in Example 1 are actually used with the current conventional line for the Ni-Cr-Mo based low alloy cast iron disk 1. The block test pieces 2 and 2 of the comparative example made of the same material (RD501A) as the brake lining used are pressed with a pressing force of 184 kgf (surface pressure 1 MPa), and the friction speed is 7 m / sec, 14 m / sec, 21 m / sec. The test was conducted five times at each friction speed. The temperature of the disk 1 at the start of the friction test was 60 ° C. or less, and sliding was performed before increasing the friction speed to ensure that the block test pieces 2 and 2 were in contact with the disk 1 reliably. In FIG. 2, 7 indicates a screw.

  The disk 1 has an outer diameter of 206 mm, an inner diameter of 85 mm, and a thickness of 20 mm. The block test piece 2 has a square shape with a length of 30 mm and a width of 30 mm, and a thickness of 10.5 mm.

  As a result, the results shown in Tables 1 to 5 below were obtained (each numerical value described in Tables 1 to 5 represents an average value of 5 times). Table 1 shows the coefficient of friction in accordance with JIS D4411-1993, Table 2 shows the amount of wear of the block test piece 2 (average value of two pieces: g), and Table 3 shows the amount of wear (g) of the disk 1. Table 4 shows the maximum temperature during the test (average value of two: ° C) measured with the thermocouple embedded in the block test piece 2, and Table 5 shows the test temperature measured with the thermocouple embedded in the disk 1 Indicates the maximum temperature (° C).

  As shown in Table 2, the amount of wear of the block test piece of Example 1 of the present invention is that of the block test piece of the comparative example of the same material (RD501A) as that of the brake lining actually used in the existing conventional line. Compared with the wear amount, the wear amount of the block test piece of Example 1 of the present invention is more than the wear amount of the block test piece of the comparative example at the friction speeds of 14 m / sec and 21 m / sec. It can be seen that the wear resistance of the disk brake material of the present invention is excellent.

  The present invention is suitable as a material for disc brakes of various rotary traveling devices.

1 Disc 2 Block specimen 3 Screw

Claims (1)

  15 to 150 parts by weight of carbon fiber, 15 to 150 parts by weight of coal tar, 2 to 30 parts by weight of graphite, and 80 to 600 parts by weight of aluminum titanate Disc brake material comprising a ceramic sintered powder and 100 parts by weight of a polymer resin.