JPH0535770B2

JPH0535770B2 -

Info

Publication number: JPH0535770B2
Application number: JP60155829A
Authority: JP
Inventors: Hideo Suzuki; Mikio Yura; Hironori Suzuki
Original assignee: FCC Co Ltd
Current assignee: FCC Co Ltd
Priority date: 1985-07-15
Filing date: 1985-07-15
Publication date: 1993-05-27
Also published as: JPS6217435A

Description

[Detailed description of the invention]

Ａ発明の目的 (1) 産業上の利用分野本発明は、主として摩擦クラツチに用いられる
摩擦材の製造方法に関する。 (2) 従来の技術従来、此の種の摩擦材としては、アスベストヤ
ーンにフエノール系レジンを含浸させ、これに摩
擦性能向上剤を添加したもの、アスベスト、フエ
ノール系レジン、無機粉末等を混合したものをモ
ールド成形したもの等が知られている。 (3) 発明が解決しようとする課題しかしながら上記摩擦材はアスベストを主体と
するので、その摩擦材が摩耗した場合、その摩耗
粉により大気が汚染される虞れがあり、公害防止
を図る上に好ましくない。本発明は上記に鑑み提案されたもので、従来の
ものの上記問題を解消しながら優れた摩擦性能を
発揮することができ、しかも低比重で且つ高強度
の摩擦材を提供することを目的とする。Ｂ発明の構成 (1) 課題を解決するための手段上記目的を達成するために本発明は、セルロー
ス系繊維を５〜30重量％、ポリアミド系繊維を２
〜30重量％、ガラス繊維を２〜20重量％、また摩
擦性能向上剤を30〜80重量％それぞれ配合したも
のを湿式抄造して抄造体を製造し、その抄造体に
フエノール系レジンを含浸させたものを加熱加圧
成形して所定形状の摩擦材を得ることを特徴とす
る。 (2) 作用上記特定量のセルロース系繊維、ポリアミド系
繊維、ガラス繊維および摩擦性能向上剤を配合し
たものより抄造体を得るようにしているため、そ
の湿式抄造性が良好となるばかりか、その抄造体
にフエノール系レジンを含浸させてから加熱加圧
成形を施して得られる摩擦材の摩擦性能が次のよ
うに向上する。即ち、その摩擦材は、優れた耐摩
耗性と高低温時および低すべり速度時における大
きな摩擦係数を有し、使用初期におけるフエード
が小さく、低温時における摩擦係数特性（すべり
による摩擦係数の変化が少ない等）が良好である
等の優れた物性を備えており、しかも摩耗粉にア
スベストが含まれないから、アスベスウトに因る
大気汚染を惹起する虞れはなくなる。また特に上記摩擦材は、抄造体をベースとして
いるので、繊維相互の絡みで効果的に保形され、
そのため、例えば配合物を単に混合モールド成形
する場合と比べて、バインダとしてのフエノール
系レジンの使用量が少なくて済むから、低比重化
が可能で、遠心力による破壊強度が向上する。ま
た上記繊維相互に絡みが強いことに起因して、摩
擦材の強度も向上する。前記各種繊維等の含有量を前記のように特定し
た理由は下記の通りである。ａセルロース系繊維についてこの繊維の含有量が30重量％を上回ると、前
記基材より得られた摩擦材の摩耗量が多くな
る、低温時における摩擦係数特性が悪化してク
ラツチ接続時に車両が振動を起す、いわゆるジ
ヤダを発生する、高温時および低すべり速度時
における摩擦係数が低くなる、使用初期におけ
るフエードが大きくなる等の不具合を生じる。また前記繊維の含有量が５重量％を下回る
と、前記摩擦材の使用初期および低すべり速度
時における摩擦係数が低くなる、回転破壊強度
が小さい等の不具合を生じ、また抄造体の湿式
造性が悪化する。ｂポリアミド系繊維についてこの繊維の含有量が30重量％を上回ると、前
記摩擦材の使用初期および低すべり速度時にお
ける摩擦係数が低くなる。また前記繊維が２重量％を下回ると、前記摩
擦材の摩耗量が多くなる、低温時における前記
摩擦係数特性が悪化してジヤダを発生する、高
温時における摩擦係数が低くなる、使用初期に
おけるフエードが大きくなる、回転破壊速度が
小さい等の不具合を生じ、また抄造体の湿式抄
造性が悪化する。ｃガラス繊維についてこの繊維の含有量が20重量％を上回ると、前
記摩擦材の低温時における摩擦係数が低下し、
その上前記摩擦係数特性が悪化してジヤダを発
生する。また前記繊維の含有量が２重量％を下回る
と、前記摩擦材の摩耗量が多くなる、低すべり
速度時における摩擦係数が低くなる等の不具合
を生じる。ｄ摩擦性能向上剤についてこの摩擦性能向上剤の含有量が80重量％を上
回ると、前記摩擦材の回転破壊強度、引張り強
度等が低下する。また前記含有量が30重量％を下回ると、前記
摩擦材の摩耗量が多くなる、摩擦係数特性が悪
化する等の不具合を生じる。 (3) 実施例セルロース系繊維としては、木材繊維、コツト
ンリンターパルプのような綿繊維、靭皮繊維等が
該当するが、レーヨンも含まれる。ポリアミド系繊維としては、例えば芳香族ポリ
アミド繊維であるケブラー（米国デユポン社製・
商標名）が該当し、チツプドフアイバ・パルプ状
等のものである。ガラス繊維は、直径９〜13μｍのものを２〜20
mmの長さに切断して用いられるが、摩擦材用とし
て最も好ましい直径は6μｍである。摩擦性能向上剤としては、一般的な有機、無機
物の外に、チタン酸カリ繊維、ロツクウール、セ
ラミツク繊維、カーボン繊維等抄造する場合に添
加可能な繊維状のものが含まれる。また金属粉
末、金属繊維も摩擦性能向上剤として用いられる
こともある。下表は本発明方法を実施する際の中間生成物と
しての抄造体およびその比較例〜の配合例を
示す。数値の単位は重量％である。 A. Object of the Invention (1) Industrial Field of Application The present invention relates primarily to a method for producing a friction material used in a friction clutch. (2) Conventional technology Conventionally, this type of friction material has been made by impregnating asbestos yarn with phenolic resin and adding a friction performance improver to it, or by mixing asbestos, phenolic resin, inorganic powder, etc. Molded products are known. (3) Problems to be Solved by the Invention However, since the above-mentioned friction material is mainly made of asbestos, when the friction material wears out, there is a risk that the atmosphere will be polluted by the abrasion powder. Undesirable. The present invention has been proposed in view of the above, and aims to provide a friction material that can exhibit excellent friction performance while solving the above problems of conventional materials, has a low specific gravity, and has high strength. . B. Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides 5 to 30% by weight of cellulose fibers and 2% by weight of polyamide fibers.
~30% by weight, 2 to 20% by weight of glass fiber, and 30 to 80% by weight of a friction performance improver are wet-processed to produce a paper product, and the paper product is impregnated with a phenolic resin. A friction material having a predetermined shape is obtained by heat-pressing molding. (2) Function Since a paper product is obtained by blending the specified amounts of cellulose fibers, polyamide fibers, glass fibers, and a friction performance improver, not only does the wet paper formability of the product improve, but The friction performance of the friction material obtained by impregnating the paper product with a phenolic resin and then subjecting it to heat and pressure molding is improved as follows. In other words, the friction material has excellent wear resistance and a large friction coefficient at high and low temperatures and at low sliding speeds, has little fade in the initial stage of use, and has excellent friction coefficient characteristics at low temperatures (changes in friction coefficient due to sliding). The material has excellent physical properties such as low (e.g., less) wear particles, and since the wear particles do not contain asbestos, there is no risk of air pollution caused by asbestos. In particular, since the above-mentioned friction material is based on a paper product, its shape is effectively retained by the intertwining of the fibers.
Therefore, compared to, for example, simply mixing and molding a compound, the amount of phenolic resin used as a binder can be reduced, making it possible to lower the specific gravity and improve the breaking strength due to centrifugal force. Furthermore, due to the strong intertwining of the fibers, the strength of the friction material is also improved. The reason for specifying the contents of the various fibers and the like as described above is as follows. a Regarding cellulose fibers: If the content of this fiber exceeds 30% by weight, the amount of wear of the friction material obtained from the base material increases, the friction coefficient characteristics at low temperatures deteriorate, and the vehicle vibrates when the clutch is engaged. This causes problems such as so-called jitter, a decrease in the coefficient of friction at high temperatures and low sliding speeds, and an increase in fade during the initial stage of use. Furthermore, if the content of the fibers is less than 5% by weight, problems such as a low coefficient of friction at the initial stage of use of the friction material and at low sliding speeds, a low rotational fracture strength, etc., and wet forming properties of the paper product may occur. becomes worse. b Regarding polyamide fibers When the content of this fiber exceeds 30% by weight, the friction coefficient of the friction material at the initial stage of use and at low sliding speeds becomes low. If the content of the fibers is less than 2% by weight, the amount of wear of the friction material increases, the friction coefficient characteristics at low temperatures deteriorate and jitter occurs, the friction coefficient at high temperatures decreases, and fading occurs during the initial use. Problems such as an increase in the rotational speed and a low rotational breaking speed occur, and the wet papermaking properties of the papermaking body deteriorate. c Regarding glass fibers When the content of this fiber exceeds 20% by weight, the friction coefficient of the friction material at low temperatures decreases,
Moreover, the friction coefficient characteristics are deteriorated and jitter occurs. Furthermore, if the content of the fibers is less than 2% by weight, problems such as an increase in the amount of wear of the friction material and a decrease in the coefficient of friction at low sliding speeds occur. d Regarding the friction performance improver When the content of the friction performance improver exceeds 80% by weight, the rotational breaking strength, tensile strength, etc. of the friction material decrease. Further, if the content is less than 30% by weight, problems such as increased wear of the friction material and deterioration of the friction coefficient characteristics will occur. (3) Examples Cellulose fibers include wood fibers, cotton fibers such as cotton linter pulp, bast fibers, and rayon. Examples of polyamide fibers include Kevlar, an aromatic polyamide fiber (manufactured by DuPont in the United States;
(Trade name) is applicable, and it is in the form of chipped fiber or pulp. Glass fibers have a diameter of 9 to 13 μm.
It is used by cutting it into lengths of mm, but the most preferred diameter for friction materials is 6 μm. Friction performance improvers include, in addition to general organic and inorganic materials, fibrous materials that can be added during papermaking, such as potassium titanate fibers, rock wool, ceramic fibers, and carbon fibers. Metal powders and metal fibers are also sometimes used as friction performance improvers. The table below shows paper products as intermediate products when carrying out the method of the present invention and comparative examples thereof. The numerical unit is weight %.

【表】前記表においてケブラーパルプの平均繊維長さ
は５mmであり、またガラス繊維は直径6μｍで、
長さ６mmである。また摩擦性能向上剤は、カシユ
ーダスト、チタン酸カリ繊維、硫酸バリウム、炭
酸カルシウム、および金属粉末を含む金属繊維の
混合物である。前記表の配合物を用いて湿式抄造法により、厚
さ0.8〜1.0mmの４種の抄造体を製造し、その各抄
造体にフエノール系レジンを基材全重量の18重量
％となるように含浸して乾燥し、各乾燥体を巻取
つた後幅８mmの帯状に切断して４種の基材を得
る。そして、その各々の基材について、それらの
重合体を常法により加熱加圧成形し、外形200mm、
内径140mm、厚さ3.5mmで、比重1.3〜1.4の摩擦ク
ラツチ用摩擦材を４種類得た。その各摩擦材を慣性体式クラツチフルサイズテ
スタに装着し、慣性体（フライホイール）を所定
の回転数で回転させた後その慣性体の駆動を停止
し、次いでクラツチを断続して各摩擦材の摩擦係
数を測定したところ図示の結果が得られた。尚、測定条件は、慣性体の入力回転数1650r.p.
m.、慣性体の慣性モーメト0.058Kg・ｍ・s²、測
定間隔４回／分であり、またクラツチ断続回数
3000回終了後測定を中止してクラツチを常温まで
空冷し、その後測定を再開した。図において、線ａは本発明を適用した摩擦材に
該当し、線ｂ，ｃ，ｄは比較例〜に対応した
摩擦材にそれぞれ該当する。図面から明らかなように、線ａに示す本発明の
摩擦材は、線ｂ〜ｄに示す比較例の摩擦材に比べ
て大きな摩擦係数を有し、しかもその値はクラツ
チ断続回数が増加する、したがつて摩擦材の温度
が高くなつても略一定であり、優秀な摩擦性能を
備えている。Ｃ発明の効果本発明によれば、前記特定量のセルロース系繊
維、ポリアミド系繊維、ガラス繊維および摩擦性
能向上剤を配合したものより抄造体を得るように
しているので、その湿式抄造体が良好となるばか
りか、その抄造体のフエノール系レジンを含浸さ
せてから加熱加圧成形を施して得られる摩擦材の
摩擦性能を高めることができ、しかもその摩擦粉
にアスベストが含まれないから、アスベストに因
る大気汚染の発生を防止することができる。また特に上記摩擦材は、抄造体をベースとして
いるので、繊維相互の絡みで効果的に保形され、
そのため、バインダとしてのフエノール系レジン
の使用量が少なくて済んで低比重化が可能であ
り、遠心力による破壊強度を向上させることがで
きる。また上記繊維相互に絡みが強いことに起因
して、摩擦材の強度も向上させることができる。[Table] In the above table, the average fiber length of Kevlar pulp is 5 mm, and the diameter of glass fiber is 6 μm.
The length is 6mm. The friction performance improver is also a mixture of metal fibers including cashew dust, potassium titanate fibers, barium sulfate, calcium carbonate, and metal powder. Four types of paper products with a thickness of 0.8 to 1.0 mm were manufactured by a wet papermaking method using the formulations in the table above, and phenolic resin was added to each paper product in an amount of 18% by weight of the total weight of the base material. After impregnation and drying, each dried product was wound up and cut into strips with a width of 8 mm to obtain four types of base materials. Then, for each base material, these polymers were molded under heat and pressure using a conventional method, and the outer diameter was 200 mm.
Four types of friction materials for friction clutches with an inner diameter of 140 mm, a thickness of 3.5 mm, and a specific gravity of 1.3 to 1.4 were obtained. Each of the friction materials is attached to an inertial body type clutch full-size tester, the inertia body (flywheel) is rotated at a predetermined number of rotations, the drive of the inertia body is stopped, and the clutch is then engaged intermittently to test each friction material. When the coefficient of friction was measured, the results shown in the figure were obtained. The measurement conditions are: input rotation speed of the inertial body 1650 r.p.
m., the moment of inertia of the inertial body is 0.058Kg・m・s ² , the measurement interval is 4 times/minute, and the number of times the clutch is engaged
After 3000 cycles, the measurement was stopped, the clutch was air cooled to room temperature, and then the measurement was restarted. In the figure, line a corresponds to the friction material to which the present invention is applied, and lines b, c, and d correspond to the friction materials corresponding to comparative examples, respectively. As is clear from the drawings, the friction material of the present invention shown by line a has a larger friction coefficient than the friction material of the comparative example shown by lines b to d, and the value increases as the number of times the clutch is engaged increases. Therefore, even if the temperature of the friction material increases, it remains approximately constant and has excellent friction performance. C. Effects of the Invention According to the present invention, a paper-formed body is obtained by blending the specific amounts of cellulose fibers, polyamide-based fibers, glass fibers, and a friction performance improver, so that the wet-process paper-formed body is good. Not only that, but the friction performance of the friction material obtained by impregnating the paper body with phenolic resin and then applying heat and pressure molding can be improved, and since the friction powder does not contain asbestos, it is possible to improve the friction performance of the friction material. It is possible to prevent air pollution caused by air pollution. In particular, since the above-mentioned friction material is based on a paper product, its shape is effectively retained by the intertwining of the fibers.
Therefore, the amount of phenolic resin used as a binder can be reduced, the specific gravity can be lowered, and the breaking strength due to centrifugal force can be improved. Furthermore, due to the strong intertwining of the fibers, the strength of the friction material can also be improved.

[Brief explanation of the drawing]

図面は、本発明基材および比較例基材より得ら
れた摩擦材におけるクラツチ断続回数の摩擦係数
の関係を示すグラフである。 The drawing is a graph showing the relationship between the friction coefficient and the number of clutch discontinuations in the friction materials obtained from the base material of the present invention and the base material of the comparative example.

Claims

[Claims]

1 Wet-formed paper containing 5 to 30% by weight of cellulose fibers, 2 to 30% by weight of polyamide fibers, 2 to 20% by weight of glass fibers, and 30 to 80% by weight of friction performance improvers. Manufacture a paper product,
A method for manufacturing a friction material, which comprises impregnating the paper product with a phenolic resin and molding the same under heat and pressure to obtain a friction material in a predetermined shape.