JPH11181585A - Rust preventive coating material, back plate coated with rust preventive coating material and frictional material using back plate for frictional material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart rust preventive effect to a frictional material in the case the coating material is applid thereto and to suppress the generation of the braking squeak therein by composing it of a mixture contg. liq. resin and powdery rubber. SOLUTION: As for the frictional material, e.g. a disk brake pad, the materials contg. liq. resin and powdery rubber are mixed to obtain paste for rust preventive coating material 1, this paste is applied on the surface on the side to be stuck with the frictional member 3 of a back plate 2 for the frictional material, is thereafter inserted into a temporary molding die, is temporarily molded at a prescribed temp. and is furthermore subjected to baking treatment in a hot air drying furnace. Then, the surface of the rust preventive coating material 1 is coated with an adhesive to a prescribed thickness, then, the back plate 2 for the frictional material is inserted into a thermal pressure molding die in such a manner that the face of the rust preventive coating material 1 coated with the adhesive orientates toward the upper direction, the material for the frictional member or a frictional member premolded body is inserted into the upper part, thereafter, they are integrally molded by a heating pressure molding, the back plate 2 for the frictional material, the rust preventive coating material 1 and the frictional member 3 are stuck, thereafter heat treatment is executed, and the surface is polished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rust-proof coating material suitable for a friction material such as a disc brake pad and a brake lining used for braking an automobile, a railway vehicle, and the like, and a back metal for a friction material coated with a rust-proof coating material. And a friction material using a back metal for the friction material.

[0002]

2. Description of the Related Art For example, a disc brake is used as a braking device for an automobile or the like, and there is a disc brake pad as a braking member thereof. As a rust-proofing treatment of the back metal in the conventional disc brake pad, for example, as shown in JP-A-51-24533, the surface of the back metal is subjected to a chemical treatment such as nitriding treatment,
As shown in Japanese Patent Application Laid-Open No. 69618, it is generally known that a back metal is coated with an epoxy resin, a phenol aldehyde resin, or the like.

According to the above-mentioned method, the rust prevention effect can satisfy the demands of the market, but there is another problem that a brake squeal called a squeal noise mainly occurs during the brake braking.

[0004]

SUMMARY OF THE INVENTION The first aspect of the present invention is to provide a rust preventive coating material suitable for a friction material capable of suppressing a rust effect and suppressing brake squeal. The second aspect of the present invention provides a friction material backing metal suitable for a friction material capable of preventing rust and producing brake squeal. The third aspect of the present invention is to provide a friction material capable of suppressing rust and suppressing occurrence of brake squeal.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a rust preventive coating material comprising a mixture containing a liquid resin and a rubber powder. The present invention also relates to a back metal for a friction material in which the surface on the side to which the friction member is fixed is coated with the above rust-preventive coating material. Further, the present invention relates to a friction material in which a friction member is fixed to a surface of the above-mentioned back metal for a friction material, which is coated with a rust-preventive film material.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A mixture containing a liquid resin and a powdered rubber is used for obtaining the rust-preventive coating material of the present invention. Among the liquid resins, for example, phenol-epoxy resin, phenol resin, epoxy resin, melamine Resins, urethane resins, alkyd resins, etc. are used.
For example, NBR, SBR, natural rubber and the like are used. The ratio of liquid resin to powdered rubber is 5% liquid resin (as solid content).
The amount of the powder rubber is preferably 20 to 95% by weight to 80% by weight in view of the rust prevention effect and the suppression of the occurrence of brake squeal, and the powder rubber 55 to 15 to 45% by weight of the liquid resin (as solid content) is preferred. More preferably, it is from 85 to 85% by weight, and still more preferably from 70 to 80% by weight of the powdered rubber to 20 to 30% by weight of the liquid resin (as solid content).

[0007] The viscosity of the mixture of the liquid resin and the powdered rubber (paste for a rust-proof coating material) is preferably 30 to 100 poise at 20 ° C, more preferably 45 to 85 poise, and more preferably 60 to 70 poise. Is more preferable. The thickness of the rust preventive coating material coated on the surface of the friction metal backing metal is preferably 0.05 to 0.15 mm, more preferably 0.07 to 0.13 mm, and more preferably 0.09 to 0.15 mm after provisional molding.
0.11 mm is more preferred.

[0008] The compounding of the friction member to be fixed to the surface of the back metal for the friction material coated with the rust-preventive coating material may be any of a semi-metallic system, a non-steel system, a metal system including a sintered body, and a C / C composite system. There is no particular limitation as well. As the material of the friction member, generally known materials are used, for example, steel fiber, brass fiber, copper fiber, aramid fiber, acrylic fiber, phenol fiber, ceramic fiber, rock wool, potassium titanate fiber, calcium silicate fiber , Fibrous substances such as carbon fibers, thermosetting resins such as phenolic resins, epoxy resins, melamine resins, and cashew resins; binders containing rubber compositions such as NBR and SBR; organic friction modifiers such as friction dust; Inorganic friction modifiers such as barium, calcium carbonate, and magnesium carbonate; rust inhibitors such as calcium hydroxide; lubricants such as graphite and molybdenum disulfide; and metals such as zinc, brass, and copper as needed. Flour is added.

The mixing ratio of the above-mentioned materials is appropriately selected depending on the material of the friction member, and is not particularly limited. For example, the content of the fibrous substance is preferably 35 to 65% by weight in the whole composition, and 40 to 50% by weight. More preferably, the content is 60% by weight. The content of the binder is 15 to 35% by weight in the total composition.
It is preferably contained, more preferably from 20 to 30% by weight. The content of the friction modifier is preferably 3 to 20% by weight, more preferably 5 to 15% by weight in the whole composition. The content of the rust inhibitor is preferably 1 to 8% by weight in the whole composition, and 2 to 6% by weight.
More preferably, it is contained by weight. The content of the lubricant is preferably 1 to 15% by weight in the whole composition,
More preferably, the content is 3 to 10% by weight. Further, the content of the metal powder to be added as needed is 3 to 3 in the total composition.
The content is preferably 15% by weight, more preferably 5 to 12% by weight. These components are blended so that the total composition becomes 100% by weight.

The friction material according to the present invention, for example, a disc brake pad, is obtained by mixing a material containing a liquid resin and a powder rubber to obtain a paste for a rust-preventive film material, and then applying the paste for a rust-preventive film material to a friction material. After being applied to the surface of the back metal to which the friction member is fixed, it is inserted into a temporary molding die, temporarily molded at a temperature of 100 to 150 ° C., and further heated in a hot air drying oven at 140 to 200 ° C.
A baking treatment is performed at a temperature of 10C for 10 to 120 minutes. An adhesive is applied to the surface of the rust-preventive coating material after baking to a thickness of 10 to 30 μm, and then the adhesive is applied to a hot-press forming mold. After inserting the material powder for the friction member or the preform of the friction member into the upper part thereof, integrally molding by the heating and pressing molding method, and fixing the back metal for the friction material, the rust prevention coating material and the friction member, It is obtained by performing heat treatment and polishing the surface.

The heating temperature at the time of integral molding by the heat and pressure molding method is preferably 130 to 170 ° C., and 140 to 160 ° C.
C is more preferred. The pressure is preferably 30 to 60 MPa, more preferably 40 to 55 MPa. The heat treatment temperature in the subsequent step is preferably 100 to 300 ° C, and 150 to 250 ° C.
C is more preferred.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a disk brake according to an embodiment of the present invention, wherein 1 is a rust-preventive coating material, 2 is a backing metal for a friction material, and 3 is a friction member.

[0013]

Embodiments of the present invention will be described below. Example 1 The components shown in Table 1 were blended, uniformly mixed with a mixer to obtain a friction material composition, and then preformed to obtain a friction material preform. On the other hand, a phenol-epoxy resin solution (Cashew)
20% by weight of NBR powder (manufactured by Nippon Zeon Co., Ltd., trade name of Nippol 1411) 80
The weight% was mixed by stirring to obtain a paste for a rust-proof coating material having a viscosity of 65 poise. Next, after applying this paste for a rust-preventive film material to the surface of the back metal for a friction member on the side to which the friction member is fixed, the paste is inserted into a temporary molding die and temporarily molded at 130 ° C. for 3 minutes.
A rust preventive coating material having a thickness of 1.0 mm was coated, and further baked at 160 ° C. for 60 minutes in a hot air drying oven.

Thereafter, an adhesive (Cemedine No. 110, trade name, manufactured by Cemedine Co., Ltd.) was applied to the surface of the rust-preventive coating material for 20 μm.
m, and the backing for friction material is inserted into a hot-press forming mold heated to 143 ± 5 ° C. with the surface on which the adhesive is applied facing upward, and a friction member preform is placed on the upper part thereof. Insert
Heating and pressurizing was performed for 6 minutes under the condition of a pressure of 50 MPa to perform integral molding. Next, after heat-treating at 180 ° C. for 5.5 hours, the surface is polished and the rust-proof coating material 1 and the backing metal 2 for the friction material shown in FIG.
And a disk brake pad composed of the friction member 3.

Comparative Example 1 A disc brake pad was obtained through the same steps as in Example 1 except that the surface of the backing metal for a friction member was not coated with a rust preventive film material.

[0016]

[Table 1]

Next, the disc brake pad obtained in Example 1 and the disc brake pad obtained in Comparative Example 1 were immersed in salt water for 10 minutes, left in air for 120 minutes, and dried at 70 ° C. for 30 minutes as one cycle. After performing this for 500 cycles, the rusting area in the shear plane was measured in accordance with JIS D4415. As a result, the rusting area of the disc brake pad obtained in Example 1 was 0%, but the disc brake pad obtained in Comparative Example 1 was 10%.
0% rust had occurred.

In addition to the above, the disc brake pad obtained in Example 1 and the disc brake pad obtained in Comparative Example 1 were subjected to a constant temperature and humidity test and a salt spray test according to JIS D 4419. The resulting disc brake pad was measured for the rusted area at the joint between the backing material for friction material and the rust-proof coating material, and the disc brake pad obtained in Comparative Example 1 was measured for the rusting area at the joint between the backing material for friction material and the friction member. . As a result, the disc brake pad obtained in Example 1 had a rusting area of 0%, but the disc brake pad obtained in Comparative Example 1 had 20% rust.

Further, the disc brake pad obtained in Example 1 and the disc brake pad obtained in Comparative Example 1 were examined for brake squeal. As a result, the disc brake pad obtained in Example 1 did not generate brake squeal, but the disc brake pad obtained in Comparative Example 1 had a defect that brake squeal occurred. The test was conducted on an actual vehicle [vehicle weight: 1180k
g, brake model: collet type (cylinder area: 2
5cm ² ), driving in an urban area (1000k
m) was performed and the sensitivity was evaluated.

[0020]

According to the first aspect of the present invention, a rust-preventive coating material can provide a friction material capable of preventing rust and having a rust-preventing effect. The backing material for a friction material according to the second aspect can provide a friction material capable of preventing rust and generating brake squeal. The friction material according to claim 3 is industrially extremely suitable because it can prevent rust and suppress the occurrence of brake squeal.

[Brief description of the drawings]

FIG. 1 is a sectional view of a disc brake according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rust prevention coating material 2 Back metal for friction material 3 Friction member

Claims (3)

[Claims] 1. A rust preventive coating material comprising a mixture containing a liquid resin and a powder rubber. 2. The method according to claim 1, wherein the surface on the side to which the friction member is fixed is provided.
A back metal for a friction material, which is coated with the rust-preventive film material described. 3. A friction material wherein a friction member is fixed to a surface of the back metal for a friction material according to claim 2, which is coated with a rust-proof coating material.