JPS6052623A - Surface treatment of heat-meltable yarn - Google Patents

Abstract

PURPOSE:To prevent occurrence of fusion between monofilaments during heat drawing and heat treatment, by attaching water dispersion containing specific inorganic fine powder and water-soluble sizing agent to the surface of heat- meltable yarn. CONSTITUTION:Heat-meltable yarn [e.g., yarn having high strength and high modulus of elasticity having a repeating unit shown by the formula -NR1-Ar1 -NR2-CO-Ar2-CO-(R1 and R2 are H, or lower alkyl; Ar1 and Ar2 are aromatic residue, etc.) is immersed in water dispersion containing (A) inorganic fine powder (e.g., talc, etc.) comprising hydrous magnesium silicate having <=5mu average particle diameter, and (B) a water-soluble sizing agent (e.g., polyethylene oxide, etc.), so that the yarn is provided with a preferable amount of 0.05-2.0wt% (calculated as anhydrous state) fine powder A based on the total yarn weight, it is drawn under heating and/or heat-treated.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for surface modification of heat-fusible fibers.

In more detail [, < refers to modifying the surface of the hot-melt fiber such that fusion between single yarns occurs during hot drawing and/or heat treatment to generate fuzz and/or yarn breakage during hot drawing and/or heat treatment. [7] and relates to a method for preventing fusion between single yarns.

In recent years, the demand for χ↑ for fibers has become more sophisticated1, especially for high strength,
In response to the demand for high modulus, various new materials have been developed and studied. For some of them, in order to achieve high performance, high-strength stretching at high temperatures or heat treatment processes at high temperatures are applied, and undesirable fusion between single filaments occurs during this process. do. That is, among the fibers that exhibit fusibility during drawing and/or heat treatment, there are single yarns, I,
However, when multifilament fiber bundles are drawn and/or heat treated at high temperatures, the performance of aggregates and fibers is significantly degraded due to the occurrence of inter-filament bonding. There are many things that can be damaged.

As a method for preventing the above-mentioned fusion between single filaments, the present inventors first applied water 111 to the surface of the fiber during hot drawing and/or heat treatment.
A method of applying a gel-forming inorganic compound was proposed (Japanese Patent Application No. 151944/1982).

It has been found that even with this h method, the effect of preventing fusion between single yarns decreases as the number of single yarns constituting the fiber bundle increases.

To solve this problem, the present inventors conducted extensive research [and as a result, applied an aqueous dispersion of a hydrated glue-forming inorganic compound to fibers].
When drying by drying, the moisture on the fibers decreases and the water-gel-forming inorganic compound aggregates and becomes coarse particles.As the number of single fibers in the fiber bundle increases, the compound spreads uniformly onto the fiber surface. It turned out that it was no longer possible to cover the

Purpose of the Invention The purpose of the present invention is to provide an industrially advantageous method for preventing fusion between single filaments that occurs when hot-melting fibers are hot-drawn and/or heat-treated at high temperatures as described above. .

The constitution of the invention, that is, the present invention is to apply an aqueous dispersion containing a water-soluble sizing agent and an inorganic fine powder mainly composed of hydrated magnesium silicate with an average particle size of 5 μ or less to the fiber surface when producing heat-fusible fibers. This is a method for surface treatment of heat-fusible fibers, which is characterized in that after adhering to the fibers 1-5, heat-stretching and/or heat treatment are carried out.

The thermofusible fibers referred to in the present invention are fibers made of the following polymers, which have recently been developed and researched as high-strength, high-modulus fibers. That is, repeating polymer [as one unit, for example -? JR, -A r, -NR, -Co-A
r, -Co- and/Ichitake-NR, -AR, -CO- It is an aromatic polyamide or an aromatic copolyamide composed of.

As aromatic copolyamides, for example, fully aromatic polyamides consisting of aromatic residues (p-phenylene, 2,6 naphthalene, 4,4'-diphenyl, etc.) having straight and/or parallel axial bonds, .Copolymerization of 4'-diphenyl ether, 4'-diphenyl ether, m-7 enylene, etc., and further substituting some of the hydrogen atoms of aromatic residues with halogen atoms and/or lower furkyl groups. Among them, aromatic copolyamides with improved drawability when formed into fibers include Arl,
Art l Arm is 80 molti or more, and the molti of the structural unit CB) is 10 to 40, and &,'
An aromatic fupolyamide in which all of R4, R, and R are hydrogen atoms is preferred.

Or, in the repeating unit of the following openings ~ ■, C), (
D), F) and/or (6) or (C1, (1')
and/or an aromatic tubophmid hydrazilad 5- consisting of (2) can also be used.

-NR, -Ar, -Co-NH-NH-(C)-ratio-
Art-+JR*-Q)1 →JRI Arm -co-(t)-Co-Art-co (lliM) Such aromatic copolyamide hydrazides include, for example, aromatic copolyamides having straight and/or parallel axial bonds. Examples include aromatic tuborifumido hydrazide in which a hydrazide bond is introduced into a wholly aromatic polyamide containing group residues.
Preferably, 80 moles or more of Ar, + are p-phenylene residues, and R1°, R, , R, are all hydrogen atoms.

Or repeat 1 below. Aromatic oxadiazole/methyl hydrazide copolymers such as units O) and (1) may also be used.

\1 C) tI ■ -CO-A rt -CO-N-NT (-σD [where Ar, l Art l R+ t Rw are the same as in the previous chapter] or form an optically anisotropic melt f- Obtain Thermoplastic polymers such as fully aromatic polygostyl, aromatic polyazomethine, etc. can also be used.

Examples of inorganic fine powders containing hydrated magnesium silicate as a main component and 1. Examples include fine powder commonly called talc. In particular, it is necessary to use fine particles having an average particle size of 5 μm or less. The method for applying these inorganic fine powders containing hydrated magnesium silicate as a main component to the fiber surface includes applying an aqueous dispersion containing the fine powder and a water-soluble sizing agent to the fibers.1. One method is to dry it after drying. The amount to be applied, j, is the fine powder (on anhydrous basis) relative to the weight of the fiber.
,05 to 2.0chi. If the applied amount is less than 0.01% by weight, no effect of fiber surface modification such as prevention of fusion can be expected.
On the other hand, even if the content exceeds 8% by weight, not only is no significant improvement in the fiber surface modification effect observed, but also fine powder is detached from the fibers during the process before the fibers are wound or during the process of processing the fibers. This may cause problems such as staining the thread guide. Furthermore, when fibers are used as a rubber reinforcing material or molded product reinforcing material (for FRP, etc.), the adhesion to rubber or resin may be reduced.1. Melt.

In order to uniformly cover the fibers with a small amount of fine powder, the smaller the particle size of the fine powder, the better -1! 1. It is effective that the average particle diameter of the fine powder is 5μ or less).

On the other hand, if the particle size of the fine powder is large, it is not only necessary to use a large amount of fine powder to uniformly coat the fiber (in addition, it is necessary to use a large amount of fine powder in the drawing process, winding process, or processing process). This is undesirable as there are many cases where people become detached.

Attach fine powder to the fiber surface 1. 1. For example, a method can be used in which the undrawn yarn is immersed in an aqueous sizing solution in which the fine powder is dispersed. In this case, compared to the method of adhesion using an oiling roller,
7. It can be applied uniformly to the fibers and can be coated. The amount of adhesion to the fibers can be adjusted by changing the immersion time or by changing the concentration of the dispersion liquid. Alternatively, a method may be adopted in which the amount of adhesion is adjusted by squeezing the fine powder dispersion from the yarn after soaking using a squeezing roller.

In this case, the sizing agent increases the viscosity of the dispersion, suppresses sedimentation of the dispersion powder, and enhances the conjugation of the treated yarn. Therefore, the generation of single yarn fuzz and even single yarn breakage during running can be prevented, thereby improving productivity.

9- Note that the 5 sizing agents here generally refer to fiber treatment agents and 1. Any water-soluble glue used in the process may be used, but especially when processing with a heating element at temperatures as high as 5 degrees Celsius or higher, use a glue that does not leave any residue after heating, such as polyethylene oxide. gawi ma [,i.

Effects of the Invention By using the method of the present invention, fusion between single yarns can be prevented or reduced, and the occurrence of fuzz and/or yarn breakage can be prevented without impairing fiber performance.

Particularly when the number of single yarns constituting the fiber bundle is large, a remarkable effect can be obtained. Such effects will be specifically explained in the following examples and comparative examples.

Examples Below, we will explain our invention according to examples.
The main characteristic values used in the following examples were rated 1-1 in accordance with the following method.

(1) Intrinsic viscosity of polymer TV (1nhsrent
viscosity) 10 - Using an Ostwald type viscosity tube, only the solvent σ) The flow time to (seconds), the flow time of a dilute solution of the polymer t (seconds)
, the polymer concentration in the dilute solution is C(f/100
rat ) Tosult, expressed as. Unless otherwise specified, the solvent was 97.5% sulfuric acid, C==0,5 f/
Measure at 100 rnl and 30°C.

(2) Tensile properties of fibers Using an Instron tensile testing machine, the loading curve is measured at an initial length of 25 m and a tensile speed of 1 Ocrn/min at 20° C. and 65% RH in a photographic atmosphere. From this strength (f/de)
, elongation (chi), and Young's modulus (f/de) are calculated.

(3) Degree of fusion (f) The value obtained by dividing the number of single filaments that should originally exist in the yarn by the number of filaments actually counted in the yarn after drawing or heat treatment is used. That is, it shows the average number of fused single filaments that one filament after drawing or heat treatment consists of. Measurements were made at 5 locations 11, and the average value was taken as f.

Example 1. Comparative Examples 1-2 An aromatic copolyamide of IV=31 composed of the following monomers was converted into N-methyl-2 containing calcium chloride (CaC4).
- A polymer solution of 6% by weight dissolved in pyrrolidone (NMP") was poured into
Extrusion at a discharge speed of 1 minute (-). About tO in the air.
After running W, it was coagulated in a coagulation bath of N-methyl-pyrrolidone/water (30/70% by weight) at 50°C, and 30t
It was pulled down at a speed of n/min and then washed in a water bath at 50°C. The water-washed thread is made of Alcox E-6 made from polyethylene oxide [Keiho Kagaku Kogyo @] with an average molecular weight of 1 million.
It was immersed in a solution prepared by dispersing 1 weight % of talc powder with an average particle size of 1.5 μm in an aqueous solution of 0.01 and 0.085% by weight.
After squeezing it with a roller, it was wound on a drying roller and dried. Fine powder $ +7) Solid content and 1. The amount of adhesion was about 0.6 inch based on the weight of the dry yarn. Subsequently, the film was stretched 12 times on a hot plate at 500°C, coated with an oil agent, and then wound up. Table 1 shows the physical properties of the obtained yarn.

Note that Comparative Example 1 is an example in which a sizing agent (polyethylene oxide) was not added to the talc dispersion, and a dispersion containing 100 g of water was used. In addition, Comparative Example 2 has 0.0% hydrous aluminum silicate.
This is the case where a 5-weight polyhydric solution was used.

13-Table 1 Note that the number of fluffs here refers to the running yarn 100 before winding the yarn.
Discovered by observing 0m 1. It is the number of fuzz that occurs per hour, and the number of thread cuts is 1. This is the number of thread breaks.

Examples 2-3. Comparative Examples 3 to 4 Spinning and stretching were carried out according to Example 1, using a polyethylene oxide aqueous solution at ℃ while changing the average particle diameter of talc as shown in the following table. The performance of the obtained thread is that the particle size of talc is 5
If it is more than μ, not only will there be more fusion 14-, but also the amount of powder deposited on the yarn guiding guide after applying talc will increase, and this will get caught in the yarn and cause yarn breakage and yarn breakage.
Because this caused fuzz, I had to stop spinning the yarn from time to time (and clean the yarn guiding guide).The knots are shown in Table 2.
．． Table 1, Table 2 * The evaluation of talc deposition on the medium thread guide in this table was based on the following criteria.

O: Amount of talc deposited 1- to very small △: Some amount of talc deposited ×: Large amount of talc deposited 15- 157-

Claims (1)

[Claims] When producing hot-melt fibers, an aqueous dispersion containing an inorganic fine powder mainly composed of hydrated magnesium silicate with an average particle diameter of 5 μm or less and a water-soluble sizing agent is attached to the fiber surface.1. 1. A method for surface treatment of heat-fusible fibers, which comprises heating and/or heat-treating the fibers.