JP2018053254A - Non-asbestos friction material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-asbestos friction material composition capable of providing a friction material which is excellent in abrasion resistance at a high temperature and produces little metal catch even when a content of copper is little, and to provide a fiction material and a friction member using the non-asbestos friction material composition.SOLUTION: A non-asbestos friction material composition is a friction material composition containing a binder, an organic filler, an inorganic filler and a fiber base material, where a content of copper in the friction material composition is 5 mass% or less as a copper element, a content of metal fibers other than copper and a copper alloy is 0.5 mass% or less, a content of the organic filler is 1-20 mass%, a content of titanate is 13-24 mass%, a content of zirconium oxide is 5-30 mass% and a content of zirconium oxide having a particle diameter of more than 30 μm is 1.0 mass% or less.SELECTED DRAWING: None

Description

  The present invention relates to a non-asbestos friction material composition, a friction material using the same, and a friction member. Specifically, it is suitable for friction materials such as disc brake pads and brake linings used for braking in automobiles, etc., and has a low copper content, so it is environmentally friendly, has excellent wear resistance at high temperatures, and generates metal catches. The present invention relates to a small amount of non-asbestos friction material composition, and further relates to a friction material and a friction member using the non-asbestos friction material composition.

  In automobiles and the like, friction materials such as disc brake pads and brake linings are used for braking. The friction material plays a role of braking by friction with facing materials such as a disk rotor and a brake drum. Therefore, the friction material is required not only to have a high coefficient of friction and stability of the coefficient of friction, but also to have a long pad life (wear resistance) in a wide brake operating temperature range from low temperature to high temperature.

  Further, in a high temperature range where the brake is used, metal wear powder lumps called metal catches are generated on the surface of the friction material, and the wear amount of the disk rotor and the friction material may increase, and the brake may squeal. Then, in order to improve wear resistance at high temperatures and suppress metal catches, it has been proposed to blend metal sulfides (see Patent Document 1).

  On the other hand, the friction material includes a binder, a fiber base material, an inorganic filler, an organic filler, and the like, and in general, a combination of one or two or more of them in order to develop the above characteristics. included. Organic fibers, metal fibers, inorganic fibers, and the like are used as the fiber base material, and copper and copper alloy fibers are used as the metal fibers in order to improve wear resistance. Further, as the friction material, non-asbestos friction material has become the mainstream, and copper, copper alloy, and the like are used in a large amount for this non-asbestos friction material.

  However, friction materials containing copper and copper alloys contain copper in the wear powder generated during braking, and it has been suggested that it may cause river, lake and marine pollution. It is growing. Therefore, a method is proposed in which magnesium oxide and graphite are contained in a friction material in an amount of 45 to 80% by volume and the ratio of magnesium oxide and graphite is 1/1 to 4/1 without containing metal such as copper or copper alloy. (See Patent Document 2).

JP 2003-313312 A JP 2002-138273 A

  However, it has been difficult to achieve both high-temperature wear resistance and suppression of metal catches with friction materials that have been developed so far with a low copper and copper alloy content.

  Accordingly, the present invention provides a non-asbestos friction material composition that can provide a friction material that is excellent in wear resistance at high temperatures and generates little metal catch even when the content of copper and copper alloy is small, and It aims at providing the friction material and friction member using a non-asbestos friction material composition.

As a result of intensive studies, the present inventors have determined that the content of copper as an element is not more than a certain level in a non-asbestos friction material composition, the content of metal fibers other than copper and copper alloys is not more than a certain value, and titanium. The inventors have found that the above problems can be solved by containing a specific amount of an acid salt and further containing zirconium oxide having a specific particle diameter, and have completed the present invention.
That is, the present invention is as follows.

[1] A friction material composition comprising a binder, an organic filler, an inorganic filler, and a fiber substrate,
The content of copper in the friction material composition is 5% by mass or less as copper element, the content of metal fibers other than copper and copper alloy is 0.5% by mass or less, and the content of organic filler is 1 to 20% by mass, the content of titanate is 13 to 24% by mass, the content of zirconium oxide is 5 to 30% by mass, and the content of zirconium oxide having a particle diameter of more than 30 μm is 1.0. A non-asbestos friction material composition having a mass% or less.
[2] The non-asbestos friction material composition according to [1], wherein the fiber base material is at least one selected from the group consisting of inorganic fibers, metal fibers, organic fibers, and carbon-based fibers.
[3] The non-asbestos friction material composition according to [1] or [2], wherein the content of the fiber base material is 5 to 40% by mass.
[4] A friction material formed by molding the non-asbestos friction material composition according to any one of [1] to [3].
[5] A friction member formed using a friction material obtained by molding the non-asbestos friction material composition according to any one of [1] to [3] and a back metal.

  The non-asbestos friction material composition of the present invention is environmentally friendly because it has less copper in the wear powder produced during braking when used in friction materials such as automotive disc brake pads and brake linings. It is excellent in wear and can suppress metal catch. Moreover, the friction material and friction member which have the said characteristic can be provided by using the non-asbestos friction material composition of this invention.

Hereinafter, the non-asbestos friction material composition of the present invention, the friction material using the same, and the friction member will be described in detail.
[Non-asbestos friction material composition]
The non-asbestos friction material composition of the present invention is a friction material composition including a binder, an organic filler, an inorganic filler, and a fiber base material, and the copper content in the friction material composition is as a copper element. 5% by mass or less, the content of metal fibers other than copper and copper alloy is 0.5% by mass or less, contains titanate and zirconium oxide having a particle size of 30 μm or less, and the titanate It is characterized by not containing the zirconium oxide which is content of 10-35 mass% and whose particle diameter exceeds 30 micrometers.
Due to the above configuration, the amount of copper in the wear powder generated during braking is less than that of conventional products, so that it is environmentally friendly, has excellent wear resistance at high temperatures, and can suppress the metal catch. .

(Binder)
The binding material integrates the organic filler, the inorganic filler, the fiber base, and the like contained in the friction material composition to give strength. There is no restriction | limiting in particular as a binder contained in the non-asbestos friction material composition of this invention, Usually, the thermosetting resin used as a binder of a friction material can be used.
Examples of the thermosetting resin include phenol resins; various elastomer-dispersed phenol resins such as acrylic elastomer-dispersed phenol resins and silicone elastomer-dispersed phenol resins; acrylic-modified phenol resins, silicone-modified phenol resins, cashew-modified phenol resins, and epoxy-modified phenols. Various modified phenol resins such as resins and alkylbenzene-modified phenol resins can be used, and these can be used alone or in combination of two or more. In particular, it is preferable to use a phenol resin, an acrylic-modified phenol resin, a silicone-modified phenol resin, or an alkylbenzene-modified phenol resin because good heat resistance, moldability, and friction coefficient are given.

  The content of the binder in the non-asbestos friction material composition of the present invention is preferably 5 to 20% by mass, and more preferably 5 to 10% by mass. By setting the content of the binder in the range of 5 to 20% by mass, it is possible to further suppress the strength reduction of the friction material, reduce the porosity of the friction material, and increase the elastic modulus. Vibration performance deterioration can be suppressed.

(Organic filler)
The organic filler is included as a friction modifier for improving the sound vibration performance and wear resistance of the friction material. The organic filler contained in the non-asbestos friction material composition of the present invention is not particularly limited as long as it can exhibit the above performance, and usually uses cashew dust, a rubber component, etc., used as an organic filler. Can do.
The cashew dust is not particularly limited as long as it is obtained by pulverizing a hardened cashew nut shell oil and is usually used for a friction material.
Examples of the rubber component include tire rubber, acrylic rubber, isoprene rubber, NBR (nitrile butadiene rubber), SBR (styrene butadiene rubber) and the like, and these are used alone or in combination of two or more.
In addition, cashew dust and a rubber component may be used in combination, or cashew dust coated with a rubber component may be used, but from the viewpoint of sound vibration performance, it is preferable to use cashew dust and a rubber component in combination. .

  The content of the organic filler in the non-asbestos friction material composition of the present invention is preferably 1 to 20% by mass, more preferably 1 to 10% by mass, and 3 to 8% by mass. Is more preferable. By making the content of the organic filler in the range of 1 to 20% by mass, the elastic modulus of the friction material can be increased, deterioration of sound vibration performance such as squeal can be avoided, heat resistance deterioration, heat It is possible to avoid a decrease in strength due to history. Moreover, when using cashew dust and a rubber component together, it is preferable that cashew dust and a rubber component are the ratio of 2: 1-10: 1 by mass ratio, and it is 3: 1-9: 1. More preferably, it is 3: 1 to 8: 1.

(Inorganic filler)
The inorganic filler is included as a friction modifier for avoiding deterioration of the heat resistance of the friction material, and in the present invention, titanate and zirconium oxide are essential as the inorganic filler.
As the titanate, potassium titanate, lithium potassium titanate, magnesium potassium titanate, or the like can be used. Examples of potassium titanate include K ₂ O · 6TiO ₂ and K ₂ O · 8TiO ₂ . Examples of the lithium potassium titanate include those having a composition represented by K _0.3-0.7 Li _0.27 Ti _1.73 O _3.8-3.95 produced by mixing a titanium source, a lithium source, and a potassium source. The titanate magnesium potassium, for example, those having a composition represented by K _0.2-0.7 Mg _0.4 Ti _1.6 O _3.7-3.95 prepared by mixing a titanium source and a magnesium source and potassium source.
These can be used alone or in combination of two or more. Among these, lithium potassium titanate and magnesium potassium titanate are preferable because they further improve the wear resistance at high temperatures.

As the shape of the titanate, a fiber, a column, a plate, a particle or a scale can be used, and these can be used alone or in combination of two or more.
The shape of the titanate can be analyzed, for example, by observation with a scanning electron microscope (SEM).
Here, an example of the definition about the shape of titanate will be described. Of the rectangular parallelepipeds circumscribing the titanate, the longest side of the rectangular parallelepiped having the smallest volume (the circumscribed rectangular parallelepiped) is the major axis L, the next longest side is the minor axis B, and the shortest side is the thickness T (B> T). ), And the shape of titanate is defined by the aspect ratio (L / T, L / B).
The fibrous titanate is a titanate having an L / T larger than 10 and an L / B larger than 10. For example, Tismo D, Tismo N (both manufactured by Otsuka Chemical Co., Ltd.) and the like can be mentioned.
The columnar titanate is a titanate having L / T = 2 to 10 and L / B = 2 to 10. And TOFIX-S (manufactured by Toho Material Co., Ltd.).
The plate-like titanate is a titanate having L / T larger than 10 and L / B smaller than 10. For example, TXAX-A, TXAX-MA, TXAX-KA, TXAX-CT (all manufactured by Kubota Corporation) and the like can be mentioned.

The particulate titanate is a titanate having an L / T smaller than 10 and an L / B smaller than 2. For example, TOFIX-SGL (manufactured by Toho Material Co., Ltd.), GTX-C (manufactured by Kubota Co., Ltd.) and the like can be mentioned.
Further, among the particulate titanates, those having a thin plate shape such as a scale are referred to as scaly titanates. For example, Terraces PS, Terraces PM, Terraces L, Terraces TF-S (both are Otsuka Chemical Co., Ltd.).
Among the above shapes, in order to further improve the high temperature wear resistance, it is preferable to use a scaly, columnar, or plate-shaped one.
Moreover, an average particle diameter of 1-50 micrometers and a specific surface area of 0.5-10 m < ² > / g are preferable. In addition, an average particle diameter is represented by a median diameter, and a median diameter shows 50% diameter calculated | required from the volume distribution of the laser diffraction method. The specific surface area can be determined by a BET method using nitrogen gas as an adsorption gas.

  The content of titanate in the non-asbestos friction material composition of the present invention is 10 to 35% by mass and 13 to 24% by mass from the viewpoint of improvement of wear resistance at high temperature and suppression of metal catch. It is preferable that it is 14 to 20% by mass. When the content of titanate is less than 10% by mass, the wear resistance tends to deteriorate and metal catches tend to be generated. Moreover, when content exceeds 35 mass%, there exists a tendency for abrasion resistance to deteriorate, a friction coefficient to fall, and also a metal catch to be easy to produce | generate.

The composition for a non-asbestos friction material according to the present invention contains, as an essential component, zirconium oxide having a particle size of 30 μm or less (hereinafter sometimes simply referred to as zirconium oxide) as an inorganic filler, and has a particle size exceeding 30 μm. Contains substantially no zirconium oxide. Preferably, the zirconium oxide has a particle size of 28 μm or less and substantially does not contain zirconium oxide having a particle size exceeding 28 μm, more preferably the zirconium oxide has a particle size of 25 μm or less and a particle size of 25 μm. It is to contain substantially no zirconium oxide.
By using zirconium oxide having a particle size of 30 μm or less, good high-temperature wear resistance is exhibited, and metal catch can be suppressed. The minimum particle diameter of zirconium oxide having a particle diameter of 30 μm or less is not particularly limited, but the particle diameter is preferably 0.1 μm or more.

  Here, “substantially does not contain” means, for example, that when the particle diameter does not substantially contain zirconium oxide exceeding 30 μm, the particle diameter of the zirconium oxide contained in the friction material composition of the present invention is The proportion of zirconium oxide exceeding 30 μm is 1.0% by mass or less, more preferably 0.5% by mass or less, and not containing zirconium oxide particles exceeding 30 μm (0% by mass). preferable.

  The content of zirconium oxide is preferably 2 to 41% by mass, and more preferably 1 to 40% by mass. By setting the content of zirconium oxide to 2 to 41% by mass, preferably 1 to 40% by mass, excellent wear resistance can be exhibited and metal catch can be suppressed. Moreover, in order to express these effects more, it is more preferable that it is 5-30 mass%, and it is especially preferable that it is 5-20 mass%.

The average particle diameter of zirconium oxide is preferably 1 to 7 μm, more preferably 1 to 6.5 μm, and still more preferably 1 to 6 μm. When the average particle diameter of zirconium oxide is 1 μm or more, a good friction coefficient and wear resistance are exhibited, and when it is 7 μm or less, deterioration of wear resistance can be avoided.
The particle size and average particle size of zirconium oxide can be measured using a method such as laser diffraction particle size distribution measurement. For example, it can be measured with a laser diffraction / scattering particle size distribution measuring apparatus LA.920 (manufactured by Horiba). The average particle diameter refers to a 50% diameter obtained from the volume distribution of the particle size distribution.

The non-asbestos friction material composition of the present invention can further contain an inorganic filler other than the titanate and zirconium oxide. The inorganic filler that can be contained is not particularly limited as long as it is normally used for a friction material.
Examples of the inorganic filler include tin sulfide, molybdenum disulfide, iron sulfide, antimony trisulfide, bismuth sulfide, zinc sulfide, calcium hydroxide, calcium oxide, sodium carbonate, calcium carbonate, magnesium carbonate, barium sulfate, dolomite, Coke, graphite, mica, iron oxide, vermiculite, calcium sulfate, talc, clay, zeolite, zirconium silicate, zirconium oxide, mullite, chromite, titanium oxide, magnesium oxide, silica, iron oxide, γ-alumina, etc. These can be used singly or in combination of two or more. Among these, it is preferable to contain graphite and barium sulfate from the viewpoint of reducing the aggressiveness to the facing material, and it is preferable to contain antimony trisulfide from the viewpoint of improving the friction coefficient.

  The content of the inorganic filler in the non-asbestos friction material composition of the present invention is preferably 30 to 80% by mass, more preferably 40 to 80% by mass, and 60 to 80% by mass. Further preferred. By making content of an inorganic filler into the range of 30-80 mass%, deterioration of heat resistance can be avoided. The content of the inorganic filler includes the content of the titanate and zirconium oxide having a specific particle size.

(Fiber substrate)
The fiber base material exhibits a reinforcing action in the friction material.
As the fiber base material contained in the non-asbestos friction material composition of the present invention, inorganic fibers, metal fibers, organic fibers, carbon fibers, etc., which are usually used as fiber base materials, can be used alone. Alternatively, two or more types can be used in combination. In addition, the fibrous base material here does not include the above-described fibrous form of titanate.

As said inorganic fiber, a ceramic fiber, a biodegradable ceramic fiber, a mineral fiber, glass fiber, a silicate fiber etc. can be used, It can use 1 type or in combination of 2 or more types.
The mineral fiber referred to here is a man-made inorganic fiber melt-spun mainly composed of blast furnace slag such as slag wool, basalt such as basalt fiber, and other natural rocks, and is a natural mineral containing Al element. Is more preferable. Specifically, those containing SiO ₂ , Al ₂ O ₃ , CaO, MgO, FeO, Na ₂ O, etc., or those containing one or more of these compounds can be used, more preferably. Of these, those containing Al element can be used as mineral fibers. Since the adhesive strength with each component in the friction composition tends to decrease as the average fiber length of the entire mineral fiber contained in the friction material composition increases, the average fiber length of the entire mineral fiber is preferably 500 μm or less, More preferably, it is 100-400 micrometers. Here, the average fiber length refers to a number average fiber length indicating an average value of the lengths of all corresponding fibers. For example, the average fiber length of 200 μm indicates that 50 mineral fibers used as a friction material composition raw material are randomly selected, the fiber length is measured with an optical microscope, and the average value is 200 μm.

The mineral fiber used in the present invention is preferably biosoluble from the viewpoint of human harm. The term “biosoluble mineral fiber” as used herein refers to a mineral fiber having a characteristic that even if it is taken into the human body, it is partially decomposed and discharged outside the body in a short time. Specifically, the chemical composition is alkali oxide, alkaline earth oxide total amount (total amount of oxides of sodium, potassium, calcium, magnesium, barium) is 18% by mass or more, and in a short-term biopermanent test by respiration, A fiber that has a mass half-life of 20 μm or more within 40 days or no evidence of excessive carcinogenicity in an intraperitoneal test or that has no associated pathogenicity or tumor development in a long-term respiratory test (EU Directive 97 / 69 / EC NotaQ (carcinogenic exclusion)). Examples of such biodegradable mineral fibers include SiO ₂ —Al ₂ O ₃ —CaO—MgO—FeO—Na ₂ O fibers and the like, and include SiO ₂ , Al ₂ O ₃ , CaO, MgO, FeO, Na. Examples thereof include fibers containing ₂ O or the like in any combination. As a commercial product, LAPIUSFIBERSB. For example, V Roxul series. “Roxul” includes SiO ₂ , Al ₂ O ₃ , CaO, MgO, FeO, Na ₂ O and the like.

As the metal fibers, copper or copper alloy fibers can be used to improve crack resistance and wear resistance. However, when the copper or copper alloy fiber is contained, considering the environmental friendliness, the total content of copper in the friction material composition needs to be in the range of 5% by mass or less as the copper element. .
As the fiber of copper or copper alloy, copper fiber, brass fiber, bronze fiber, or the like can be used, and these can be used alone or in combination of two or more.

Further, as the metal fiber, metal fibers other than copper and copper alloy may be used from the viewpoint of improving the friction coefficient and crack resistance, but the content is 0.5 from the viewpoint of improving wear resistance and suppressing metal catch. It needs to be less than mass%. Preferably, the wear resistance is deteriorated and metal catches are easily generated for the improvement of the friction coefficient, and therefore metal fibers other than copper and copper alloy are not contained (content 0 mass%).
Examples of metal fibers other than copper and copper alloys include, for example, fibers in the form of single metals or alloys such as aluminum, iron, zinc, tin, titanium, nickel, magnesium, and silicon, and fibers mainly composed of metals such as cast iron fibers. These can be used alone or in combination of two or more.

As the organic fiber, an aramid fiber, a cellulose fiber, an acrylic fiber, a phenol resin fiber (having a cross-linked structure) and the like can be used, and these can be used alone or in combination of two or more, and wear resistance From the viewpoint of properties, it is preferable to use an aramid fiber.
As the carbon-based fiber, flame-resistant fiber, pitch-based carbon fiber, PAN-based carbon fiber, activated carbon fiber, or the like can be used, and these can be used alone or in combination of two or more.

  The content of the fiber base material in the non-asbestos friction material composition of the present invention is preferably 5 to 40% by mass, more preferably 5 to 20% by mass, and 5 to 18% by mass. Further preferred. By making the content of the fiber base in the range of 5 to 40% by mass, an optimum porosity as a friction material can be obtained, squeal can be prevented, an appropriate material strength can be obtained, and wear resistance can be exhibited. The moldability can be improved. In addition, content of the metal fiber of copper or a copper alloy is contained in content of the said fiber base material.

(Other materials)
The non-asbestos friction material composition of this invention can mix | blend other materials as needed other than the said binder, an organic filler, an inorganic filler, and a fiber base material.
For example, in the non-asbestos friction material composition of the present invention, the total copper content is 5% by mass or less as a copper element, and metal powder such as copper powder, brass powder, bronze powder, etc. is blended. Can do. In addition, from the viewpoint of wear resistance, an organic additive such as a fluorine-based polymer such as PTFE (polytetrafluoroethylene) can be blended.

[Friction material and friction member]
The present invention also provides a friction material and a friction member using the above-described non-asbestos friction material composition.
The non-asbestos friction material composition of the present invention can be used as a friction material for disc brake pads and brake linings of automobiles and the like by molding the composition. Since the friction material of the present invention is excellent in wear resistance at high temperatures and metal catch control, it is suitable for a friction material of a disc brake pad having a large load during braking.
Furthermore, by using the friction material, it is possible to obtain a friction member in which the friction material is formed to be a friction surface. Examples of the friction member that can be formed using the friction material include the following configurations.

(1) Configuration of friction material only.
(2) The structure which has a back metal and the friction material which consists of a friction material composition of this invention used as a friction surface on this back metal.
(3) In the configuration of (2) above, between the back metal and the friction material, a primer layer for the purpose of surface modification for enhancing the adhesion effect of the back metal, and for the purpose of bonding the back metal and the friction material A configuration in which an adhesive layer is further interposed.
The backing metal is usually used as a friction member in order to improve the mechanical strength of the friction member. As the material, metal or fiber reinforced plastic can be used. For example, iron, stainless steel, inorganic fiber Examples thereof include reinforced plastic and carbon fiber reinforced plastic. The primer layer and the adhesive layer may be those used for friction members such as brake shoes.

The friction material of the present invention can be produced by a generally used method, and is produced by molding the non-asbestos friction material composition of the present invention, preferably by hot pressing.
Specifically, the non-asbestos friction material composition of the present invention is uniformly mixed using a mixer such as a Readyge mixer, a pressure kneader, or an Eirich mixer, and this mixture is preformed in a molding die. The obtained preform is molded for 2 to 10 minutes under the conditions of a molding temperature of 130 ° C. to 160 ° C. and a molding pressure of 20 to 50 MPa, and the obtained molded product is heat-treated at 150 to 250 ° C. for 2 to 10 hours. A friction material can be manufactured by performing coating, scorch treatment, and polishing treatment as necessary.

Since the non-asbestos friction material composition of the present invention is excellent in wear resistance at high temperatures and suppression of metal catch, it is useful as a “upholstery material” for friction members such as disc brake pads and brake linings. It can also be molded and used as an “underlaying material”.
The “upper material” is a friction material that becomes the friction surface of the friction member, and the “underlay material” is a friction material that is interposed between the friction material that becomes the friction surface of the friction member and the back metal. It is a layer for the purpose of improving the shear strength and crack resistance in the vicinity of the adhesion part with the back metal.

The present invention will be described in more detail by way of examples, but is not limited by the present invention.
In addition, evaluation shown to an Example (a reference example is included) and a comparative example was performed as follows.

(1) Evaluation of wear resistance at high temperature Wear resistance is determined by braking 1000 times at a brake temperature before braking of 500 ° C., a speed before braking of 60 km / h, and a deceleration of 0.3 G. From the thickness of the friction material before and after the test, The wear amount of the friction material was calculated.
(2) Evaluation of metal catch generation In the evaluation of metal catch generation, the speed before braking is 60 km / h, the braking conditions are 1.96 m / s ² , 2.94 m / s ² , 3.92 m / s ² , twice each. After braking a total of 36 times to increase the temperature before braking from 50 ° C. to 300 ° C. at intervals of 50 ° C., the temperature is decreased from 250 ° C. to 50 ° C. at intervals of 50 ° C., and a total of 30 times under the same braking conditions as above. Brake was performed. After the test was completed, the size and number of metal catches generated on the friction material sliding surface were evaluated according to the following criteria.
A: No generation of metal catch B: 1 to 2 metal catches with a major axis of less than 2 mm C: Three or more metal catches with a major axis of less than 2 mm D: One or more metal catches with a major axis of 2 mm or more (3 ) Evaluation of friction coefficient The friction coefficient was measured based on the Japan Society of Automotive Engineers standard JASO C406, and the average value of the friction coefficient in the second efficacy test was calculated.

The wear resistance, metal catch generation and friction coefficient were evaluated using a dynamometer at an inertia of 7 kgf · m · s ² . Further, a ventilated disc rotor (manufactured by Kiriu Co., Ltd., material FC190) and a general pin slide type collet type caliper were used.

[Examples (including Reference Examples) 1 to 13 and Comparative Examples 1 to 5]
Preparation of Disc Brake Pads Materials were blended according to the blending ratio shown in Table 1, and friction material compositions of Examples (including Reference Examples) and Comparative Examples were obtained. In addition, the unit of the compounding quantity of each component of Table 1 is the mass% in a friction material composition.
This friction material composition was mixed with a ladyge mixer (manufactured by Matsubo Co., Ltd., trade name: ladyge mixer M20), and this mixture was preformed with a molding press (manufactured by Oji Kikai Kogyo Co., Ltd.). The molded product was heated and pressure-molded with a backing metal manufactured by Hitachi Automotive Systems, Ltd. using a molding press (manufactured by Sanki Seiko Co., Ltd.) for 5 minutes at a molding temperature of 145 ° C. and a molding pressure of 30 MPa. It heat-processed at 200 degreeC for 4.5 hours, grind | polished using the rotary grinder, and performed the scorch process of 500 degreeC, and obtained the disk brake pad (thickness of friction material 11mm, friction material projected area 52cm < ² >).
Table 1 shows the results of the above evaluations on the manufactured disc brake pads.

Various materials used in Examples (including Reference Examples) and Comparative Examples are as follows.
(Binder)
・ Phenolic resin: manufactured by Hitachi Chemical Co., Ltd. (trade name: HP491UP)
(Organic filler)
・ Cashew dust: Tohoku Kako Co., Ltd. (trade name: FF-1056)
(Inorganic filler)
・ Titanate 1: Otsuka Chemical Co., Ltd. (trade name: Terrases L)
Ingredients: Lithium potassium titanate, shape: flake shaped
Median diameter: 25 μm, specific surface area: 0.6 m ² / g
・ Titanate 2: Otsuka Chemical Co., Ltd. (trade name: Terrases PS)
Ingredients: Magnesium potassium titanate, shape: flake shaped
Median diameter: 4 μm, specific surface area: 2.5 m ² / g
・ Titanate 3: manufactured by Otsuka Chemical Co., Ltd. (trade name: Terrases TF-S)
Ingredients: Potassium titanate, shape: flake
Median diameter: 7 μm, specific surface area: 3.5 m ² / g
・ Titanate 4: Made by Kubota Corporation (trade name: TXAX-MA)
Ingredient: Potassium titanate, Shape: Plate
Specific surface area: 1.5 m ² / g
・ Titanate 5: manufactured by Toho Material Co., Ltd. (trade name: TOFIX-S)
Ingredients: Potassium titanate, Shape: Columnar
Median diameter: 6 μm, specific surface area: 0.9 m ² / g
・ Titanate 6: Otsuka Chemical Co., Ltd. (trade name: Tismo D)
Ingredient: Potassium titanate, Shape: Fibrous
Specific surface area: 7.0 m ² / g
Zirconium oxide 1: manufactured by Daiichi Rare Element Chemical Co., Ltd. (trade name: BR-3QZ, average particle size 2.0 μm, maximum particle size 15 μm)
Zirconium oxide 2: manufactured by Daiichi Rare Element Chemical Co., Ltd. (trade name: BR-QZ, average particle size 6.5 μm, maximum particle size 26 μm)
Zirconium oxide 3: manufactured by Daiichi Rare Element Chemical Co., Ltd. (trade name: BR-12QZ, average particle size 8.5 μm, maximum particle size 45 μm)
・ Graphite: manufactured by TIMCAL (trade name: KS75)
(Fiber substrate)
・ Aramid fiber (organic fiber): manufactured by Toray DuPont Co., Ltd. (trade name: 1F538)
・ Iron fiber (metal fiber): manufactured by GMT (trade name: # 0)
Copper fiber (metal fiber): manufactured by Sunny Metal (trade name: SCA-1070)
Mineral fiber (inorganic fiber): LAPINUS FIBERS B. Product made in V (trade name: RB240 Roxul 1000, average fiber length 300 μm)

  Examples (including Reference Examples) 1 to 13 exhibited a low friction material wear amount at 500 ° C., showed excellent wear resistance, were able to suppress metal catches, and exhibited a high friction coefficient. Comparative Example 2 containing no zirconium oxide, Comparative Example 1 containing zirconium oxide having a maximum particle diameter exceeding 30 μm, Comparative Example 3 containing less than 10% by mass of titanate, and 35% titanate containing In Comparative Example 4 containing more than% and Comparative Example 5 containing 1% by mass of iron fiber, sufficient wear resistance was not obtained, and metal catch could not be suppressed.

  The non-asbestos friction material composition of the present invention is environmentally friendly, has excellent wear resistance at high temperatures, and suppresses the formation of metal catches because there is less copper in the wear powder generated during braking compared to conventional products. Therefore, it is useful for friction materials and friction members such as disc brake pads and brake linings of automobiles.

Claims (5)

A friction material composition comprising a binder, an organic filler, an inorganic filler and a fiber substrate,
The content of copper in the friction material composition is 5% by mass or less as copper element, the content of metal fibers other than copper and copper alloy is 0.5% by mass or less, and the content of organic filler is 1 to 20% by mass, the content of titanate is 13 to 24% by mass, the content of zirconium oxide is 5 to 30% by mass, and the content of zirconium oxide having a particle diameter of more than 30 μm is 1.0. A non-asbestos friction material composition having a mass% or less.   The non-asbestos friction material composition according to claim 1, wherein the fiber base material is at least one selected from the group consisting of inorganic fibers, metal fibers, organic fibers, and carbon-based fibers.   The non-asbestos friction material composition according to claim 1 or 2, wherein the content of the fiber base material is 5 to 40% by mass.   The friction material formed by shape | molding the non-asbestos friction material composition of any one of Claims 1-3.   The friction member formed using the friction material formed by shape | molding the non-asbestos friction material composition of any one of Claims 1-3, and a back metal.