JPS6011152B2 - Method for producing sharp fibers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing sharpened fibers, in which the degree of sharpening and inclination are appropriately adjusted when sharpening the tip portion of a polyester fiber.

Traditionally, most of the bristles used for calligraphy, painting brushes, makeup, paint buckets, etc. have been made from animal hair, and there are many types of hair, including pig, raccoon dog, horse, marten, weasel, goat, fox, etc. spans over. In addition to animal hair, sharpened versions of Okayama hair, synthetic fibers such as nylon, polyester, and acrylic, have recently been used. The hairs and synthetic bristles used for these purposes are carefully selected depending on the purpose.

That is, calligraphy brushes made entirely of pongee hair are mainly made of fine animal hair such as weasel and goat hair, while paint buckets are made of pig, horse, and large synthetic fiber Okayama hair. More precisely, the state of sharpening leading to the tip is very important.

That is, those that are sharpened only near the tip are stiff, and those that are sharpened all over are thick but flexible. However, although the overall thickness of the sharpened bristles of synthetic fibers can be easily changed, it is difficult to subtly change the sharpened state.

For example, in the method of mechanical abrasion, it is not only difficult to sharpen fine bristles, but it is even more difficult to delicately change the sharpened state. Further, although sharpening by a solvent dissolution method is easier than a mechanical method, it has the disadvantage that the processing conditions are complicated and the method is expensive. That is, although the solvent dissolution method results in a sharpened state as a whole, the degree of sharpening cannot be adjusted and only a very non-uniform sharpening state occurs. The present invention aims to improve these drawbacks and relates to a manufacturing method which is characterized by being able to appropriately adjust the sharpening material in accordance with the requirements of various uses, and to obtain high-performance quality at low cost. That is, in the method of sharpening the tips of polyester fibers by immersing them in heated alkali, the present invention involves soaking polyester fibers in advance in an alkaline solution at a concentration below the treatment grade and at a concentration equal to or lower than the treatment grade. The present invention relates to a method for manufacturing a sharpened material in which the tip is then melted and sharpened using heated alkali, and the method allows the state of sharpening to be adjusted as appropriate depending on the preliminary grade and bonding conditions. The details will be explained below with reference to the drawings.

FIG. 1 is a diagram of a basic manufacturing state in which a polyester fiber bundle is soaked in an alkaline aqueous solution and sharpened.

Here, the polyester fiber may be a commonly used polyester, such as polyethylene terephthalate or polybutylene terephthalate, or a modified polyester modified with specific properties.
Further, the alkaline aqueous solution for hydrolyzing polyester is preferably an alkali metal compound such as sodium hydroxide, potassium hydroxide, or sodium bicarbonate. If the tip of the polyester synthetic fiber is placed in the treatment chamber while the temperature of the alkaline aqueous solution is raised above room temperature, the liquid will be pulled up between the fibers due to capillary action, but if there is a temperature difference between the liquid temperature and the outside air, A temperature difference occurs in the temperature of the liquid raised between the fibers. Due to this temperature difference, the degree of promotion of hydrolysis of polyester fibers differs between high and low temperature regions, resulting in differences in the sharpness of the fibers. In order to improve the above-mentioned method, the present invention makes it possible to satisfy the required value with respect to the subtle differences in the degree of sharpening within the following conditions.

That is, a polyester fiber bundle is put into an alkaline solution, and before it is sharpened, it is pre-soaked in an alkaline solution at a lower temperature than this, and by leaving it for a certain period of time, the low temperature solution soaks into the fibers, and then it is actually used. When immersed in a high-temperature treatment solution, a large temperature difference is created between the upper and lower parts of the fabric, and the intrusion of the high-temperature bath into the eastern part of the fibers is inhibited, which makes it possible to change the shape of the fiber as needed. It is something. Here, FIG. 2 shows the relationship between the pre-soaking temperature and the sharpening rate when the sharpening process is performed after soaking in a melting medium in which the pre-soaking temperature is lower than the actual treatment temperature.

In this case, the preliminary bonding may be carried out either within the sharpening treatment tank or in a separate bath. If the pre-soaking temperature is low, the temperature of the liquid that permeates into the fibers first will be low, so even if the liquid is then soaked in a high-temperature treatment tank, its permeation will be hindered, creating a large temperature difference there, causing a slightly smaller amount of water in the fibers. This results in a degree of sharpening.
Alternatively, if the pre-soaking temperature and the processing temperature are close to each other, the temperature difference between the liquid inside the fiber which has absorbed the alkaline liquid will be small.
Therefore, the sharpening rate is higher than the former.

Moreover, FIG. 3 shows the relationship between the pre-dipping time and the sharpening rate.

Even if the pre-curing temperature is the same, if the soaking time is longer, the liquid permeates into the fiber bundle more and the later permeation of the high-temperature processing liquid is inhibited, thereby reducing the sharpening rate. In this way, the sharpening rate, which was impossible with the conventional one-bath method of solvent dissolution, can be easily changed arbitrarily by using the pre-soaking method of this method and adjusting the soaking salinity and soaking time. made it possible to do so. FIG. 4 shows a phase diagram of fiber sharpening in relation to the degree of sharpening from low to high.

Figure 4: 1 shows the least sharpening, with only the tip being sharpened, resulting in a stiff waist; as you move towards 2 and 3, the sharpening increases, and 4 shows the most sharpening, with soft sharpened fibers at the waist. It is. According to this method, even the most difficult-to-process sharpened state can be easily and precisely produced to the desired sharpening rate.

Next, examples will be shown.

Example 1 Approximately 50,000 pieces of polyethylene terephthalate fibers with a diameter of 0.1 willow were collected to make a 10-length fiber, and the bundle was pre-soaked in a 20% caustic soda solution at room temperature for 60 minutes, and then 110 qo of polyethylene terephthalate fiber was collected. The powder was immersed in a 30% caustic soda solution for 1 hour as shown in Figure 1, taken out after 10 powders, washed with water, neutralized and dried.

The sharpened fibers obtained under these processing conditions were extremely stiff as shown in FIG. 41. Example 2 Approximately 5 polyethylene terephthalate fibers with a diameter of 0.07 ribs
Gather the sides together to make a 5-barrel length, and immerse this 2-barrel part in a 30% caustic soda solution at 80 pm as shown in Figure 1, and gradually let it rise and overflow for 10 minutes. The fibers were heated to 110° C., taken out after 80 minutes, washed with water, neutralized and dried. The sharpened fibers obtained under these processing conditions had a large degree of sharpening as shown in FIG. 4.

Similarly, after being diluted in a 30% caustic soda solution at 15 DEG C. for 28 minutes, the material was heated to 110 DEG C. and treated for 80 minutes. As a result, a material with a small sharpening rate as shown in FIG. 41 was obtained.

[Brief explanation of drawings]

Figure 1 shows the appearance of the sharpening device, where 1 is a treatment tank, 2
3 indicates the treatment solution and 3 indicates the fiber east to be sharpened. Figures 2 and 3 show the relationship between pre-soaking temperature, pre-soaking time and sharpening rate. Here, the sharpening rate represents the tapered state of the bristles, and the larger the value, the more tapered the bristles are, and this sharpening rate was expressed as a 100% of the weight loss after processing of the workpiece. In addition, Figure 4 is a phase diagram showing the sharpening of fibers in relation to the sharpening rate from low to high. Figure 4 1 shows the least sharpening, with only the tip being sharpened. things, 4th
Figures 2 and 4The sharpening increases as you move toward Figure 3, and Figure 4
shows the most advanced sharpening. Game figure 2 figure 3 figure O 4 figure

Claims (1)

[Claims] 1. A polyester fiber bundle is immersed in advance in an alkaline solution at a temperature equal to or lower than the treatment bath temperature and at the same concentration as the treatment bath, and then the tip of the fiber bundle is immersed in a heated alkali bath to sharpen the tip of the fiber. A method for producing sharp fibers that is characterized by the ability to tighten.