KR101894447B1 - Method for coating of the friction material and the coating composite by using the same - Google Patents

Abstract

The present invention relates to a coating composite coated by a method of coating a stiffener or friction material of a friction material or a friction material and capable of maintaining a constant friction performance and improving the functions of the friction material such as noise, noise, It is an invention having the effect of making.

Description

TECHNICAL FIELD The present invention relates to a method for coating an alkali metal titanate,

The present invention relates to a coating method of an alkali metal titanate which is used as a reinforcing material of a friction material or a friction material to maintain a constant friction performance, and a coating composite coated by the coating method.

Asbestos has been commonly used as a reinforcing material for automobile brake friction materials. However, since asbestos use regulations have been required worldwide since the early 1990s to the present day, the use of asbestos, which has been found harmful to human health, has been prohibited In recent years, the development of zeolite products has become more active as environmental regulation issues have been enhanced, and many companies are spurring development and research on zeolite products.

As is well known, an automobile brake is a device for reducing or stopping a running vehicle while continuously moving kinetic energy of a moving automobile to heat energy, or to keep a stopped vehicle in a stopped state. In the brake lining surface, which is a friction material of the brake, , The mechanical and wear process takes place, and some kinetic energy is absorbed by the engine, tire, air and viscous drag.

The brake friction material must have a certain level of frictional coefficient at which the vehicle can be braked and the frictional coefficient must be kept constant even when the frictional conditions change. The occurrence must be small, and after this fade phenomenon, it should be restored to the original level of friction coefficient. In addition, there should be no change in friction coefficient over time, no cracks in the friction material during braking, a high shear strength of the bonded friction material and back plate, and a high wear rate of the friction material and the rotor Should not. It should be possible to maintain a constant friction performance without being affected by changes in the external environment such as friction heat generated during damping and moisture or mud exposed during driving.

Accordingly, the present invention is to provide a method of coating a stiffener or a friction material of a friction material that can maintain a constant frictional performance.

For this purpose, the present invention provides a method for preparing a titanium alkoxide, comprising: a first step of preparing an alkali metal titanate by melt synthesis of titanium dioxide and an alkali metal compound; And a second step of coating the alkali metal titanate with a coating solution containing a rubber-based functional resin; And a third step of drying at 100 to 200 DEG C for 1 minute to 120 minutes.

In the first step, the melting may be performed at 1,000 to 2,000 DEG C for 1 to 4 hours.

In the second step, the coating may be sprayed or vapor-coated.

The present invention also provides a coated composite coated by the above coating method.

INDUSTRIAL APPLICABILITY The present invention has an effect of improving the functionality such as noise, noise, friction material holding and initial friction stability of the friction material.

Hereinafter, the present invention will be described in detail.

Here, unless otherwise defined in the technical terms and the scientific terms used, those having ordinary skill in the art to which the present invention belongs have the same meaning as commonly understood by those skilled in the art.

Repeated descriptions of the same technical constitution and operation as those of the conventional art will be omitted.

According to a preferred embodiment of the present invention, there is provided a method for preparing an alkali metal titanate, comprising: a first step of preparing an alkali metal titanate by melt synthesis of titanium dioxide and an alkali metal compound; And a second step of coating the alkali metal titanate with a coating solution containing a rubber-based functional resin; And a third step of drying at 100 to 200 DEG C for 1 minute to 120 minutes.

The alkali metal titanate prepared in the first step can be prepared by melt-synthesizing titanium dioxide and an alkali metal compound. The alkali metal titanate may be, for example, potassium titanate. Potassium titanate is widely used as a reinforcing material for various products such as insulating materials, organic and inorganic functional composites, and plastics, metal coatings, and ceramic reinforced stiffeners.

In the case of potassium titanate, compounds of various compositions are present and many of them are fibrous sheets. The chain of the octahedral TiO ₆ forms a tunnel structure, the potassium ion occupies the tunnel, the tunnel axis and the fiber axis are parallel, Crystal structure. In addition, it has a high melting point, a high mechanical strength, good compatibility with organic or inorganic functional resins, excellent heat insulating properties at high temperatures and good dispersibility in water, chemical stability, excellent acid resistance and alkali resistance, It has excellent physical / chemical properties with excellent cation exchange ability.

In the first step, the melting may be performed at 1,000 to 2,000 DEG C for 1 to 4 hours.

Potassium titanate can be prepared by the melt synthesis method, and more specifically, by molten synthesis of rutile natural acid and phosphorous acid (95%, 99%, 99.5%) and potassium-based high purity K ₂ CO ₃ The process conditions are established and the input power (voltage, current), the input frequency and the amount of molten metal per batch are set relative to the raw material, and the degassing (CO ₂ ) working condition, the optimum melting temperature, , The cooling condition (temperature gradient) and time, and the setting of the ingot preparation method, potassium titanate is produced.

Any materials, conditions, and synthetic methods other than the above-described methods may be used in the production of such potassium titanate.

Alkali metal titanate is a reinforcing material for asbestos-substituting automobile brake friction material, and is a widely used raw material for insulation, organic and inorganic functional composites, plastic, metal coating, and ceramic reinforced stiffener. In particular, when used as a reinforcing material for automotive brake friction materials after the organic and inorganic coating processes, it can provide excellent performance such as prevention of noise / noise of friction material, maintenance of friction material shape and initial friction stability.

The second step of the present invention is a step of coating the alkali metal titanate prepared in the first step with a coating solution containing a rubber-based functional resin. That is, organic coating is performed through coating means so that an organic coating layer is formed on the surface of the alkali metal titanate.

At this time, the coating means injects the organic coating solution filled in a spray form through the spray gun filled with the organic coating solution so that the organic coating layer is formed on the surface of the potassium titanate so that the organic coating solution can be hardened rapidly .

In other words, spray-type organic coating method using a spray gun can reduce organic coating solution by applying pressure to an organic coating solution and injecting it by using a nozzle to reduce an organic coating solution, Coating hardening can be performed, and high uniformity of thickness can be obtained.

Alternatively, the alkali metal titanate coating means may be formed by coating the organic coating solution filled through the vapor sprayer filled with the organic coating solution so that the uniform surface is maintained and the organic coating layer is formed on the surface of the alkali metal titanate to a uniform thickness. In the form of a vapor to form a coating layer on the surface of the alkali metal titanate.

That is, the vapor-blowing (Vapor Phase) processing method is a resin processing in a vapor state, and the steam blowing processing is excellent in the sparking property, the sparking property and the shape stability, and the raw material such as the potassium titanate The organic coating layer of uniform thickness is formed.

In consideration of the uniformity of the thickness of the coating layer and the shape stability of the coating layer described above, the concentration of the organic coating solution is preferably 10 to 50 wt.% For fast curing time and stable coating layer formation.

The organic coating solution may be a rubber-based functional resin. At this time, the rubber-based functional resin has a function as a rubber-based functional resin and has heat resistance, chemical resistance, abrasion resistance and the like. Rubber products based on currently available products are generally used as an emulsion, As well as wear resistance, heat resistance and chemical resistance. In addition, the rubber-based functional resin has a high durability and can be easily processed only by heat treatment without using a catalyst.

Examples of the rubber functional resin include isoprene, ethylene propylene, butadiene, styrene butadiene, polychloroprene, nitrile, butyl, polysulfide, silicon, fluoro, urethane and acrylic. Or more.

In addition, organic particles or inorganic particles may be mixed with the rubber-based functional resin. Examples of the inorganic particles include inorganic particles such as calcium carbonate, barium sulfate, silicon oxide, aluminum hydroxide, titanium oxide, zirconium oxide, magnesium fluoride, zinc oxide, Talc, glass, mica, and the like.

The particles may be mixed in an amount of 15 to 50% by weight based on 100 parts by weight of the rubber-based functional resin in consideration of the fact that the particles are acrylic copolymer particles. In order to form a stable coating layer, have.

Meanwhile, the coating layer in the second step may be dried at 100-200 ° C for 1 minute to 120 minutes, and the drying step is a step of drying the coated alkali metal titanate after the alkali metal titanate coating step.

The coating layer coated on the dried alkali metal titanate can be uniformly formed to a thickness of 50 to 60 nm.

At this time, after the drying step, it is preferable to add a packaging process for packaging the alkali metal titanate, or to add a transporting and molding process to produce a reinforcing material for the automobile brake friction material using the alkali metal titanate.

The coating composite of the present invention can be provided by forming an organic coating layer on the alkali metal titanate as described above. When such a coating composite is used as a reinforcing material for an automotive brake friction material, noise, noise, friction material formation and initial friction stability It is possible to improve the functionality of the device.

Hereinafter, the present invention will be described in more detail with reference to the following examples. It is to be understood, however, that the same is by way of illustration and example only and is not to be taken by way of limitation.

Examples 1 to 6

(95%, 99%, 99.5%) and potassium-based high-purity K ₂ CO ₃ (99.5%) were prepared and melt-synthesized at 1,500 ° C. for 3 hours to prepare 100 g of potassium titanate.

Using a toluene as a solvent, the rubber-based functional resin was stirred at room temperature for about 2 hours to complete dispersion, and a coating solution was completed. The rubber-based functional resin used is as shown in Table 1 (Examples 2, 3, 5 and 6). The prepared coating solutions were prepared at different concentrations (10, 20, 30, 40, 50 wt.%), Respectively.

Spray spraying is performed once to 10 times (once 250 ml) on the basis of 100 g of potassium titanate using spray coating method based on the completed coating solution, and dried at 100-200 ° C. for 1 minute to 120 minutes To complete a potassium titanate / organic coating complex.

Property evaluation

The properties of the potassium titanate and potassium titanate / organic coating complexes prepared in the above examples were measured under the process conditions shown in Table 2 below. The results are shown in the following Table 3, and the results of the friction characteristics are shown in Table 4 .

Claims (4)

A first step of preparing an alkali metal titanate by melt synthesis of titanium dioxide and an alkali metal compound at 1,000 to 2,000 DEG C for 1 to 4 hours;
A second step of coating the alkali metal titanate with an organic coating solution containing a rubber-based functional resin by a spraying or vaporizing method; And
And a third step of drying at 100 to 200 DEG C for 1 minute to 120 minutes,
Wherein the concentration of the organic coating solution in the second step is 10 to 50 wt%. delete delete Wherein the coating layer coated on the dried alkali metal titanate as a coating composite coated with the coating method of claim 1 has a thickness of 50 to 60 nm.