JPH02578B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a non-asbestos friction material using a rubber raw material containing sulfur or a halogen element.
The present invention relates to a friction material having a formulation that reduces rust and adhesion to the frictional material and is particularly effective as a measure to prevent rust and adhesion during parking. [Prior Art] Friction materials for automobiles and industrial machinery are usually in contact with a friction partner when the vehicle is stopped, and are pressed under high pressure, especially in parking brakes and clutch facings. On the other hand, since friction mating materials are generally made of iron-based metals, if rust occurs while the vehicle is stopped, it will become stuck, impairing maneuverability and possibly making it impossible to start. [Problems to be solved by the invention] The degree of rusting described above varies greatly depending on the properties of the friction material, but with asbestos-based (asbestos-based) friction materials, the above-mentioned rusting phenomenon can be reduced by adding a weakly alkaline material. It was highly effective as a measure to reduce rust. In addition, the asbestos-based friction material described above can ensure flexibility due to the soft structure of asbestos even in cases where flexibility is required, such as in brake linings and clutch facings. Asbestos-based friction materials do not have a soft structure like asbestos in the reinforcing material blended into them, so flexibility must be imparted by other methods. Therefore, as a method of imparting flexibility to non-asbestos friction materials, rubber dust and rubber binders are used more frequently than conventional asbestos-based friction materials, but these rubbers contain sulfur components as vulcanizing agents, or halogenated rubbers. Materials containing halogen elements, such as rubber, are used. However, these friction materials using rubber-based raw materials containing sulfur or halogen elements rapidly cause the iron-based mating plate or the iron-based components in the friction material to rust, resulting in the aforementioned reduction in adhesion. . The present inventor investigated the conventional method of keeping non-asbestos friction materials alkaline as a measure to reduce rusting and fixation in non-asbestos friction materials, but this alkaline treatment causes deterioration of the rubber components. As a result, it loses flexibility and cracks occur on the friction surface under severe usage conditions.Also, with regard to rust, ions and halogen elements have a strong rust-generating power, so depending on the conditions, alkaline treatment may be necessary. It was recognized that the problem was that it was difficult to produce an effect. [Means for Solving the Problems] Therefore, the present inventor has developed a non-asbestos friction material to prevent rusting of the friction material by removing iron-based components from the friction material composition, and to prevent sulfur and halogens from forming in the friction material. The present invention was developed as a result of various research into effective ingredients that can achieve the intended purpose without reducing friction performance as a measure to reduce sticking due to elements. The gist of the present invention is a friction material formed by heating and press-molding a non-asbestos friction material composition containing a rubber-based raw material containing sulfur or a halogen element and using a thermosetting resin and a rubber binder as binders. In the material, the above friction material formulation does not contain iron-based components, and 0.05 to 10 wt% of boric acid or a boric acid salt, or phosphoric acid or phosphate is added to 100 parts by weight of the friction material formulation to make an iron-based material. It is a friction material that is characterized by reduced rusting and adhesion to mating materials, thereby fulfilling the initial objective. [Function] That is, in the friction material of the present invention, as a result of carrying out rust tests and performance tests on various materials as effective ingredients to prevent the above-mentioned sticking, the most effective materials were boric acid, borate, Phosphoric acid and phosphate are selected. In the present invention, the amount of boric acid or phosphoric acid or their salts added is 0.05wt% to the friction material formulation.
The reason for the above reason is that the effect of addition is not sufficient if it is less than 0.05wt%. Moreover, if it is added in an amount exceeding 10 wt%, it will affect the friction performance, which is not preferable. [Example] The present invention will be explained below with reference to Examples. Example 1 Nitrile rubber (NBR) was used as the rubber binder containing sulfur, cashew dust was used as the organic dust, barium sulfate was used as the inorganic powder, graphite was used as the lubricant, and carbon fiber, aluminosilicate fiber, and non-ferrous fibers were used as the fibers. The basic composition is copper powder as the metal and phenol resin as the thermosetting resin, and the rubber binder is dissolved in methyl ethyl ketone. After thorough mixing in a mixer, preforming, drying, and heating mold. Pressure molded. Comparative samples and samples No. 1 to No. 4 of the products of the present invention, which are the basic formulations, are shown in Table 1, respectively. All numbers are wt%.

〔Effect of the invention〕

As mentioned above, the friction material of the present invention is a non-asbestos friction material that is attracting attention from the viewpoint of asbestos removal and high performance, and provides a friction material composition that is excellent in preventing rust and adhesion. for automobiles,
When used in industrial machinery, it is expected to play an important role in preventing rust from forming and sticking when the machine is stopped or parked.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are charts showing a comparison of the adhesion strength of the comparative products in Examples 1 and 2 and the product of the present invention, respectively. Vertical axis: Adhesion force (Kgf/cm ² ), horizontal axis: Sample No.
Basic... Basic formulation (comparative sample), 1... Invention sample No. 1, 2... Invention sample No. 2, 3... Invention sample No. 3, 4... Invention sample No. 4, 5... Invention sample No. 5, 6... Invention sample No. 6, 7... Invention sample No. 7, 8... Invention sample No. 8.

Claims (1)

[Claims] 1. In a friction material formed by heating and press-molding a non-asbestos friction material composition containing a rubber-based raw material containing sulfur or a halogen element and using a thermosetting resin and a rubber binder as a binder, the above-mentioned friction material Contains no iron-based components in the formulation, and per 100 parts by weight of the friction material,
A friction material characterized by adding 0.05 to 10 wt% of boric acid or a borate, or phosphoric acid or a phosphate to reduce rusting and adhesion to an iron-based mating material.