WO2012169546A1 - Non-asbestos friction material composition - Google Patents

Abstract

The present invention pertains to: a non-asbestos frictional material composition containing a binder, an organic filler, an inorganic filler and a fiber base material; and a friction material and friction member that use the non-asbestos friction material composition. The content of copper in the friction material composition is not more than 5 mass% in terms of copper elements, and the content of metal fibers other than copper and copper alloys is not more than 0.5 mass%. The friction material composition contains titanates and zirconium oxide with particle sizes of not more 30 μm, and the content of the titanates is 10 to 35 mass%. The friction material composition effectively does not contain zirconium oxide with particle sizes exceeding 30 μm.

Description

Non-asbestos friction material composition

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, 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 in a wide brake operating temperature range from a low temperature to a high temperature, that is, wear resistance.

Also, in the high temperature range where the brake is used, a lump of metal wear powder called a metal catch is generated on the surface of the friction material, and the amount of wear of the disk rotor and friction material may increase and the squeal of the brake may occur. Then, in order to improve wear resistance at high temperatures and to suppress the formation of 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 an amount of 45 to 80% by volume in the friction material without containing metals such as copper and copper alloys, and the ratio of magnesium oxide and graphite is 1/1 to 4/1. (See Patent Document 2).

JP 2003-313312 A JP 2002-138273 A

However, it has been difficult to achieve both high wear resistance at high temperatures and suppression of metal catch formation with friction materials that have been developed so far with low copper and copper alloy contents.

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 base material, wherein the copper content in the friction material composition is 5% by mass or less as a copper element, and copper and a copper alloy The metal fiber content other than the above is 0.5% by mass or less, contains titanate and zirconium oxide having a particle diameter of 30 μm or less, and the titanate content is 10 to 35% by mass. A non-asbestos friction material composition substantially free of zirconium oxide having a particle size of more than 30 μm.
2. 2. The non-asbestos friction material composition according to 1 above, wherein the titanate has a flake shape, a plate shape, or a column shape.
3. 3. The non-asbestos friction material composition according to 1 or 2, wherein the titanate is lithium potassium titanate or magnesium potassium titanate.
4). 4. The non-asbestos friction material composition according to any one of 1 to 3, wherein the content of zirconium oxide having a particle size of 30 μm or less is 1 to 40% by mass.
5. 5. A friction material obtained by molding the non-asbestos friction material composition according to any one of 1 to 4 above.
6). 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 4 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 the generation of 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 Is characterized by being essentially free of zirconium oxide having a particle size of more than 30 μm.
Due to the above configuration, the copper in the wear powder generated during braking is less than that of conventional products, so it is environmentally friendly, has excellent wear resistance at high temperatures, and can produce metal catches. it can.

(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.

In the non-asbestos friction material composition of the present invention, the content of the binder is preferably 5 to 20% by mass, and more preferably 5 to 10% by mass. By setting the binder content in the range of 5 to 20% by mass, it is possible to further suppress a decrease in the strength 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. More preferably. By setting the content of the organic filler in the range of 1 to 20% by mass, it is possible to avoid the deterioration of sound vibration performance such as squeal due to the increase in the elastic modulus of the friction material. It is possible to avoid a decrease in strength due to history. When cashew dust and a rubber component are used in combination, the cashew dust and the rubber component are preferably in a mass ratio of 2: 1 to 10: 1, and preferably 3: 1 to 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.
Titanates are advantageous in improving wear resistance at high temperatures and suppressing metal catch formation.
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 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 such as the 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 are exemplified.
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 called scaly titanates. For example, Terraces PS, Terraces PM, Terraces L, Terraces TF-S (all 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.
Further, those having an average particle diameter of 1 to 50 μm and a specific surface area of 0.5 to 10 m ² / g are preferable. In addition, an average particle diameter is represented by a median diameter, and a median diameter means the 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 improving wear resistance at high temperatures and suppressing the formation of metal catches. Preferably, the content 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 non-asbestos friction material of the present invention contains zirconium oxide having a particle size of 30 μm or less (hereinafter sometimes simply referred to as zirconium oxide) as an inorganic filler, and is oxidized with a particle size exceeding 30 μm. It contains substantially no zirconium. 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 the generation of metal catches 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. When the above-mentioned proportion of zirconium oxide having a particle diameter exceeding 30 μm exceeds 1.0% by mass, there is a possibility that the wear resistance at high temperature and the effect of suppressing the formation of metal catch cannot be expressed well.

The content of zirconium oxide is preferably 2 to 41% by mass, more preferably 1 to 40% by mass. When the zirconium oxide content is preferably 2 to 41% by mass, more preferably 1 to 40% by mass, excellent wear resistance can be exhibited and metal catch formation can be suppressed. Further, in order to express these effects more, it is more preferably 5 to 30% by mass, and particularly preferably 5 to 20% by mass.

The average particle diameter of zirconium oxide is preferably 1 to 7 μm, more preferably 1 to 6.5 μm, and even 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.
In addition, the particle diameter and average particle diameter 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, Use activated alumina such as coke, graphite, mica, iron oxide, vermiculite, calcium sulfate, talc, clay, zeolite, zirconium silicate, mullite, chromite, titanium oxide, magnesium oxide, silica, iron oxide, γ-alumina, etc. These can be used alone 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. When the content of the inorganic filler is in the range of 30 to 80% by mass, deterioration of heat resistance can be avoided. In addition, content of the said inorganic filler contains content of the said titanate and antimony trisulfide.

(Fiber base)
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.
In addition, mineral fiber here is artificial inorganic fiber melt-spun mainly using blast furnace slag such as slag wool, basalt such as basalt fiber, and other natural rocks. Specifically, natural minerals containing SiO ₂ , Al ₂ O ₃ , CaO, MgO, FeO, Na ₂ O, etc., or natural minerals containing one or more of these compounds can be used, More preferably, natural minerals containing Al element among these 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 to 400 μm. 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 Nota Q (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, including SiO ₂ , Al ₂ O ₃ , CaO, MgO, FeO, Na. the ₂ O and the like include fibers containing any combination. As a commercial item, LAPINUS FIBERS B.M. Examples include 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 from the viewpoint of improving wear resistance and suppressing metal catch formation. .5% by mass or less is required. 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 have an abrasion 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. Is more preferable. By setting the fiber substrate content in the range of 5 to 40% by mass, the optimum porosity as a friction material can be obtained, squeal can be prevented, 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 copper content is within a range of 5% by mass or less as copper element, copper-based metal powder such as copper powder, brass powder, bronze powder, and zinc. Metal powder such as powder can be blended. 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 temperature and control of metal catch generation, it is suitable for a friction material of a disk 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) A configuration having a backing metal and a friction material made of the friction material composition of the present invention, which is formed on the backing metal and forms a friction surface.
(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 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 generation, 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 a “underlaying material” for the friction member.
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 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: Generation of 1 to 2 metal catches with a major axis of less than 2 mm C: Generation of three or more metal catches with a major axis of less than 2 mm D: Generation of 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 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 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.

The various materials used in the 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-1090)
(Inorganic filler)
・ Titanate 1: manufactured by Otsuka Chemical Co., Ltd. (trade name: Terrases L)
Ingredient: lithium potassium titanate, shape: flake median diameter: 25 μm, specific surface area: 0.6 m ² / g
・ Titanate 2: manufactured by Otsuka Chemical Co., Ltd. (trade name: Terraces PS)
Ingredients: Potassium magnesium titanate, shape: flake 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: Toho Material Co., Ltd. (trade name: TOFIX-S)
Ingredient: 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
-Barium sulfate: manufactured by Sakai Chemical Co., Ltd. (trade name: BA)
・ Graphite: manufactured by TIMCAL (trade name: KS75)
-Antimony trisulfide: manufactured by Nippon Seiko Co., Ltd. (trade name: P3)
・ Zirconium oxide 1: manufactured by Daiichi Rare Element Chemical Industries, 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 Industries, Ltd. (trade name: BR-12QZ, average particle size 8.5 μm, maximum particle size 45 μm)
(Fiber base)
・ 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 1 to 13 had a small friction material wear amount at 500 ° C., showed excellent wear resistance, were able to suppress the formation of metal catches, and exhibited a high coefficient of friction. 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 having more than% and Comparative Example 5 containing 1% by mass of iron fiber, sufficient wear resistance could not be obtained, and generation of 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 (6)

A friction material composition comprising a binder, an organic filler, an inorganic filler, and a fiber base material, wherein the copper content in the friction material composition is 5% by mass or less as a copper element, and copper and a copper alloy The metal fiber content other than the above is 0.5% by mass or less, contains titanate and zirconium oxide having a particle diameter of 30 μm or less, and the titanate content is 10 to 35% by mass. A non-asbestos friction material composition substantially free of zirconium oxide having a particle size of more than 30 μm. The non-asbestos friction material composition according to claim 1, wherein the titanate is in the form of flakes, plates, or columns. The non-asbestos friction material composition according to claim 1 or 2, wherein the titanate is lithium potassium titanate or magnesium potassium titanate. 4. The non-asbestos friction material composition according to claim 1, wherein the content of zirconium oxide having a particle size of 30 μm or less is 1 to 40% by mass. A friction material formed by molding the non-asbestos friction material composition according to any one of claims 1 to 4. A friction member formed by using a friction material obtained by molding the non-asbestos friction material composition according to any one of claims 1 to 4 and a back metal.