JPS62170522A - Production of alumina filament molded article - Google Patents

Abstract

PURPOSE:To obtain the titled molded article having high strength and flexibility efficiently and stably, by processing alumina filament precursor obtained by precursor yarn forming method into a molded article in an atmosphere at a specific humidity and heat-treating. CONSTITUTION:Alumina filament precursor (preferably having 5-20wt% water content and 5-30wt% organic polymer content) obtained by precursor yarn forming method is processed into a molded article in an atmosphere at <=50% RH, preferably <=40% RH. Then, it is heat-treated to give the aimed molded article.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for efficiently and stably producing an alumina long fiber molded article that has good heat resistance, high strength, and flexibility.

[Prior Art] Conventionally, a spinning stock solution consisting of aluminum oxychloride, an organic polymer, and water is ri-ried through a spinning hole by a dry spinning method.
Regarding the method of producing alumina long fibers by preparing precursor fibers and heat-treating the precursor fibers,
For example, Patent 1117 (No. 47-3721, Japanese Unexamined Patent Publication No. 4
This is disclosed in Japanese Patent No. 7-718 and the like.

The method for producing an alumina long fiber molded body from the precursor fibers is usually performed by heat-treating the precursor fibers to form alumina long fibers. After obtaining the alumina long fibers, the alumina long fibers are processed into molded bodies of various shapes to obtain alumina long fiber molded bodies.

[Problems to be solved by the invention However, the alumina long fibers obtained by heat treating the precursor #a fibers have a tensile strength of 200 to 25 (] Kg/l1
The bending strength is very low, and the elongation is also very low, so when pressurizing the molded product, it tends to be drab, such as yarn breakage and fluff, and has poor workability. Furthermore, there was a problem in that it was difficult to obtain endless aluminum fibers themselves.

Various methods have been used in the past to deal with this problem of poor processability, and a representative method is a method in which alumina long fiber Ml is applied with a cylindrical agent or a surface treatment agent and then processed. There is. However, even with this method, improvement in processability cannot be expected much, and furthermore, it is necessary to remove the sizing agent and surface treatment agent after processing.

In the process of trying various studies to solve the problems of poor processability into molded bodies from alumina long fibers, poor processability during heat treatment, and poor productivity, the wood inventors discovered that Because the precursor fiber contains an organic polymer and water added to impart spinnability and stringiness, and has the bending strength and elongation necessary for processing into a molded article, The present inventors have discovered that when molded in a humid atmosphere of 100%, the molded product can be processed well, and that by subsequent heat treatment, a high-quality alumina long fiber molded product can be obtained with good productivity. It has been completed.

[Means for solving the problem] That is, the present invention processes an alumina long fiber precursor obtained by a precursor fiberization method into a molded body in a humidity atmosphere of 50% R1-1 (relative humidity) or less. Hereinafter, the present invention will be described in detail.

In the present invention, the alumina long Hh fiber precursor obtained by the precursor fiberization method is not particularly limited, and any fiber that can be obtained by a commonly used alumina long fiber precursor fiberization method can be used. Can you
Particularly preferred is a water content of 5 to 20% by weight and an organic polymer content of 5 to 30% by weight.

In the present invention, the alumina long fiber precursor obtained by the precursor fiberization method is processed into a molded body, but the shape of the molded body is not particularly limited and can be formed into any shape.
Examples include woven fabrics, sleeves, ropes, braids, etc.
These molded objects.

It can be manufactured using a loom, a stringing machine, a netting machine, etc.

Furthermore, the alumina long fiber precursor used to produce a molded article in this manner may be either non-twisted or twisted, but twisted is preferable.

Furthermore, depending on the fineness of the alumina long fiber precursor, it may be a single yarn, a double yarn, or a double yarn. The alumina long fiber precursor thus obtained can be handled in the same way as natural fibers or chemical fibers, and complex molding methods are also possible.

Next, in order to heat-treat the molded object formed from the alumina long fiber precursor without causing a decrease in quality, it is necessary to properly control the humidity atmosphere when processing the alumina long fiber precursor into the molded object. It is. In other words, the alumina long fiber precursor obtained by the precursor m-fiberization method is generally susceptible to the influence of a humid atmosphere, and the molded alumina long fiber precursor formed in a high humidity atmosphere is alumina after heat treatment. The flexibility of the long fiber molded product decreases and becomes brittle, leading to a decrease in quality.

Table 1 shows the relationship between the humidity atmosphere at a temperature of 20° C. during the molding process of the alumina long fiber precursor and the quality of the alumina long fiber molded product after heat treatment.

Table-1 As is clear from Table-1, the humidity atmosphere during processing of the alumina length MRA precursor molded body is 50%, which does not cause a decrease in quality.
%RH or less, preferably 40% 11 or less. When the humidity exceeds 50% RH, the strength of the alumina long fiber molded product obtained by heat treatment decreases, and it becomes brittle and lacks flexibility.

Further, the temperature at which the alumina long fiber precursor is processed into a molded product does not need to be particularly limited, and a normal temperature condition of 15° C. to 35° C. is preferably applied.

Next, in the present invention, the method for heat-treating the molded body of the alumina anti-fiber #precursor can be carried out by a conventional method, and either a continuous method or a batch method may be used. Compared to , no special equipment or devices are required.

By heat-treating the molded product as described above, a good alumina length without thread breakage or fluff can be achieved! It is possible to obtain an i&fiber molded body.

[Function] Undeveloped Iy] contains an alumina long fiber precursor or an organic polymer and water, so it has a lower tensile strength than alumina long fibers, but it has the minimum bending strength required for processing molded products. The alumina long fiber precursor has a high degree of elongation and elongation, and can be processed well into a molded product.In order to process the alumina long fiber precursor into a molded product in a humidity atmosphere of 50% RH or less, heat treatment is required. It is presumed that the flexibility of the alumina long fiber molded body is maintained and a high-strength product can be obtained.

[Example〕 Next, the present invention will be further described in detail with reference to Examples.

Here, D is denier, F is filament, S is S twist, Z is Z twist, T/M i, t TwisL/mete
Indicates r.

Example 1 An alumina long fiber precursor containing 9% by weight of polyvinyl alcohol (hereinafter referred to as PVA) and 12% by weight of water obtained by a precursor fiberization method was heated at a temperature of 2 OD/320F.
8:lOD/3 under 5°C1 humidity atmosphere 50% R11
After producing 20FX 3.5100/780 (T/M) three-piece series, it was further warped and set on a loom, and the same three-piece series was inserted into the yarn to produce a precursor woven fabric. The precursor woven fabric has been produced without any problems such as yarn breakage, fuzzing, etc. As a result of heat treatment and firing of this precursor woven fabric,
Process passability and productivity were good, and the obtained alumina long-edge ln woven fabric had good heat resistance, as well as high strength and flexibility.

Example 2 PVA obtained by precursor fiberization method: 7% by weight, moisture: 10%
Alumina long fiber precursor containing % by weight 830D/:]
20F was warped and set in a loom at a temperature of 20℃ and a humidity atmosphere of 40% RH, and the same 830D/320F was inserted into the tip yarn to produce a precursor woven fabric. We have produced precursor woven fabrics without any problems.

As a result of heat treatment and firing of this precursor woven fabric, the process passability and productivity were good, and the obtained alumina long edge m woven fabric was also 1#.
It had good heat resistance, high strength and flexibility.

Example 3 I) VAI obtained by precursor TA fiberization method: l ton 1□1%
, alumina long fiber Ii0 precursor containing 14 wt.
%RH down, 830D/:120FX9.560T/1
We have produced precursor lobes using a net-making machine by producing the plied yarn of No. 1, and the precursor lobes have been produced without any yarn breakage or draughts of fluffy caps. As a result of heat treatment and firing of this JLJ precursor rope, process passability and productivity were good, and the obtained alumina long fiber rope also had good heat resistance. Ta.

Example 4 Alumina long fiber precursor 62SD/240 containing PvΔ9 mass% and water content of 13% by weight obtained by precursor fiberization method
F, temperature 30℃, humidity atmosphere 40XRH, 625
D/240FX3.5200/Z150 (T/M) No 3
'/ After producing various types of braids, precursor braids were produced using a lace making machine, or precursor braids were produced without any drastic effects such as thread breakage or fuzzing. As a result of heat treatment and firing of this precursor braid, process passability and productivity were good, and the obtained alumina long fiber Ml string also had good heat resistance, and was also highly strong and flexible.

Comparative Example 1 Precursor m fiberization method P■Δ9% by weight, moisture 10
Alumina long fiber precursor containing T% jlj,'%8
30D/: After heat treatment and firing of 120F, three types of S8
0/V60 (T/M) was prepared and glued with PVA glue. Warp this sizing thread and set it to aa,
zl (If the alumina long fiber woven fabric is made by inserting the same rhinocerosin yarn into the yarn, the process passability and productivity during heat treatment and firing will decrease, and thread breakage will occur during weaving, resulting in poor workability and Retention decreased.

Comparative Example 2 PVA obtained by precursor fiberization method 9% by weight, moisture 13
Alumina long edge precursor containing wt% 8:lOD/32
After heat treatment and firing of 0F, 9-strand single twisted yarn 560 (T/
M) was prepared and synchronized to PV8.

If this sizing yarn was used to make alumina long fiber rope using a net making machine, the process passability and productivity during heat treatment and firing were low, and thread breakage occurred during net making, resulting in poor workability and yield. decreased.

[Effects of the Invention] The present invention has the following excellent effects by processing an alumina long fiber precursor into a molded body and heat treating it.

(1) Problems such as thread breakage and fluffing that occur when heat treating alumina long fiber precursors do not occur, and process passability is significantly improved.

(2) In heat treatment, the processing density per processing machine increases, improving productivity.

(3) After the 8th treatment, there is no need to apply a sinking agent or a surface treatment agent, which streamlines the process.

(4) Easy to handle after heat treatment.

Claims (1)

[Claims] 50% of alumina long fiber precursor obtained by precursor fiberization method
A method for producing an alumina long fiber molded article, which comprises processing the molded article into a molded article in a humidity atmosphere of %RH or less, and then heat-treating the product.