JPS5939383B2 - Surface treatment method for inorganic fibers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface treatment method for inorganic fibers, and its purpose is to form a protective film of an amorphous zirconium compound on the fiber surface by a vapor phase method, and to treat the inorganic fibers mechanically and chemically. An object of the present invention is to provide a surface treatment method for inorganic fibers that can form high-strength inorganic fibers that are highly effective in retaining initial strength by protecting them from chemical deterioration (particularly alkali deterioration).

After melt spinning, glass fibers have a very high tensile strength (200-300 kg) without mechanical or chemical surface damage.
/mA).

In order to avoid this mechanical surface damage, for example, on long glass fibers, various resin films called sizing agents are uniformly applied immediately after spinning by dipping, roll coating, spraying, etc.

However, glass wool, rock wool, etc. are processed using the disk method.
Since cotton is produced in large quantities using a high-speed air blowing method or the like, surface coating treatment during cotton production is extremely difficult and is not currently performed, and the strength of short fibers is therefore significantly reduced.

In addition, asbestos has traditionally been widely used as a reinforcing material for cement products, calcium silicate molded products, etc., but due to resource depletion and health and hygiene issues, there is an urgent need to develop asbestos substitutes. As a method of making the chemical composition of fibers alkali resistant, Z , r 02 ,
Glass fibers containing L a 203, S n 02, etc. are now commercially available.

However, even if the alkali resistance is improved, short fibers are not surface coated as described above, so the strength of the fibers themselves is reduced due to mechanical damage.

The present invention has been made in view of the above-mentioned points, and the conventional disc method and high-speed air blowing method do not apply zircon compounds to the surface of inorganic staple fibers such as glass wool and rock wool that are made into fibers in large quantities by methods such as methods. By forming a protective film uniformly and with sufficient thickness, strength deterioration due to mechanical contact between fibers is significantly reduced, and chemical strength deterioration due to alkali is also minimized. Therefore, cement, calcium silicate products, etc. The present invention provides an alkali-resistant fiber that significantly increases the reinforcing effect.

The present invention will be explained in detail below.

Inorganic short fibers are produced by guiding mineral raw materials melted at a high temperature of 1,300 to 1,500°C onto a disk rotating at high speed and turning them into fibers by the centrifugal force, or by blowing away the molten stream with a high-speed air stream or flame ejected from a nozzle. into fibers.

These short fibers are sent to a collection box by the transport air current, collected on a net conveyor, transported, and then processed into a board by spraying with resin, etc., or processed into a board from which particles are removed. After going through the granulation process, it becomes a raw material for other secondary products.

In the present invention, short fibers loosely accumulated on a net conveyor during cotton collection are conveyed as they are to a dehumidification chamber.

By flowing dry air from the nozzle in the dehumidifying chamber, the moisture on the fiber surface and between the fibers is removed.The dehumidified fibers are then conveyed into the surface treatment chamber, where the moisture concentration is 1000pp. Remove sufficient moisture in a dehumidifying chamber so that the bottom is facing down.

The short fibers fed into the surface treatment chamber have a chemical formula of Z.
r (QC4H9) 4 is sprayed from a nozzle and water vapor is simultaneously sprayed from another nozzle so that the vapors mix near the fiber surface and reach the fiber surface.

At this time, the organic zirconium compound is easily hydrolyzed and condensed on the fiber surface to form an amorphous zirconium compound film on the entire surface of the fiber and with sufficient uniformity in the thickness direction of the fiber band.

A dehumidifying gas such as dry air or N2 gas is used as a carrier gas for the processing agent vapor.

The above method differs from the conventional liquid atomization method (spray method) in which droplets are dispersed and is treated in a gaseous state, so it is sufficient to fill the narrow gaps between fibers, and the treatment vapor reaches the entire fiber. Although a film can be formed on the surface, in order to form a more uniform film in the thickness direction of the fiber strip, a suction pump may be installed under the net conveyor to suck and exhaust the processing gas that has passed through the fiber strip.

Furthermore, this method uses CVD (vapor phase chemical vapor deposition method: Chemi
One of the characteristics of this method is that, unlike the cal vapor deposition method, the treatment time can be determined arbitrarily, so that a film thickness sufficient to withstand mechanical and chemical damage can be obtained.

However, if the film thickness is too large, the film will not be able to follow the deformation of the fibers due to the flexibility of the fibers themselves, and cracks will occur in the film.

Therefore, the film thickness is 50 to 300 for fibers of 5 to 15 μφ.
Ao is appropriate.

Furthermore, in order to increase the resistance to mechanical and chemical damage, it is necessary to increase the adhesion and hardness of the coating.

The properties of these films are greatly influenced by the temperature ('l') of the surface treatment atmosphere during hydrolytic condensation and the molar ratio (h) of treatment agent vapor and water vapor.

It is usually preferable to process at T=100 to 350°C and h=0.1 to 3.0.

If T is further increased, thermal decomposition will occur, and if h is increased, white powder particles will form in the gas phase and the film forming ability will decrease.

In order to further improve the hardness and adhesion of the film, the treated fibers are dried under reduced pressure and the water H20 remaining in the film is removed.
It is also effective to remove alcohol ROH.

Since these coatings are made of amorphous zirconium compounds, deterioration in fiber strength due to cement alkaline solution is extremely small.

As mentioned above, the present invention has a chemical formula of Z r (OC4H9
) Since the organic zirconium compound produced in step 4 is brought into contact with water vapor on the fiber surface, the organic zirconium compound is hydrolyzed and condensed to form an amorphous zirconium compound film on the fiber surface. can be covered with a film to prevent mechanical damage such as strength deterioration due to mechanical contact between fibers, and the film is made of an amorphous zirconium compound that is alkali-resistant, preventing alkali deterioration. Therefore, it is possible to form high-strength fibers that have a great effect of retaining initial strength, and can be used satisfactorily as a reinforcing agent for cement, calcium silicate molded products, etc.

Further, since this film is formed in a gas phase, it has the advantage that it can be formed uniformly and sufficiently thickly on all fiber surfaces.

Next, the present invention will be specifically explained using examples.

<Example> 510245wt% Ca020wt% A12033
0wt% Mg05wt% mineral material with a composition of 1500
The molten material was melted at
Cotton was manufactured using the disk method under the conditions of 0.000 rpm and a throughput of 0.4 t/Hr.

Cotton is produced under the above conditions, and the fibers deposited on the net conveyor are carried into a dehumidifying chamber, where the fibers are sufficiently dried, and then carried into a surface treatment chamber.

Processing agent vapor and water vapor are sprayed onto the fibers at a predetermined concentration ratio from separate nozzles along with carrier gas N2, which is sucked from below the net conveyor to allow the processing agent to pass uniformly in the thickness direction of the fiber band. Perform surface treatment.

The surface treatment conditions are as follows.

0 surface treatment material Zr (OB u )
4... (manufactured by Nippon Futatsu KK) 0 Process creativity 101000pp Treatment agent vapor flow rate (including N2) 501/m1nO water vapor concentration 101000pp water vapor flow rate (
(including N2) 40A/m1nO surface treatment atmosphere temperature
The short fibers treated under the conditions of 200° C., 0 carrier gas, N2 and surface treatment time of 5 minutes or more had a diameter of 5 to 30 μφ.

The fiber surface film thickness was 110A0 on average.

A tensile strength test was conducted on these fibers by soaking them in cement alkali.

Here, the test is 0.88 g/l Na0)L 3.45
g/l KOH, 0.48 g/l Ca(OH)2
immersed in a cement alkaline solution containing
The tensile strength was measured under the following conditions: mm/min, span length 10 mm, and number of samples 660.

The results are shown in the graph of the attached drawing.

In the graph, A indicates an example, and B indicates untreated fiber.

The tensile strength (starting strength) before immersion in cement alkali is 180 kg/mr for organic zirconium compound treated fibers.
n, the untreated fiber was 140 kg/mA.

The reason why the starting strength is different for the same composition is that untreated fibers are mechanically damaged when sampling short fibers for strength measurement.

[Brief explanation of drawings]

The attached figure is a graph of tensile strength measurement data.

Claims (1)

[Claims] 1. A method for surface treatment of inorganic fibers, which comprises contacting the fiber surface with vapor of an organic zirconium compound having the chemical formula Z r (QC4H0)4 and water vapor.