JPH04153307A - Production of conjugate fiber - Google Patents

Abstract

PURPOSE:To obtain a conjugate fiber by continuously and stably supplying plural polymers by extracting a part of oligomer before polymerization, adding a modifier to produce plural species of oligomer, individually polymerizing and subjecting to conjugate spinning from a single spinning head. CONSTITUTION:Terephthalic acid and ethylene glycol are individually esterified in plural esterification tanks 7a and 7b, and a part of resultant bis-beta- hydroxyethyl terephthalate before polymerization is introduced into a branched path 3 through a valve 3a from a flowing path 2, then a modifier such as isophthalic acid is supplied from a modifier-supplying port 61a to produce plural species of oligomer, thus the oligomers are supplied into plural polymerization tanks 5a and 5b, and the oligomers are individually polymerized, then immediately supplied into a single spinning head, thus subjected to conjugate spinning to afford the objective conjugate fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing composite fibers made of a plurality of polymers.

(Prior Art) A variety of conjugate fibers made by bonding multiple polymers are used today as functional fibers. , dissolvable split fibers made by joining a dissolution-resistant polymer and an easily soluble polymer, and peelable split fibers made by joining polymers with no mutual affinity so that one component does not include the other. I can do it.

However, when manufacturing these composite fibers, multiple polymers must be prepared, which complicates the process, and problems such as deterioration specific to functional polymers arise, making it difficult to achieve efficient industrial production. It is difficult.

Conventionally, as a method for efficiently producing synthetic fibers such as polyester, the so-called continuous polymerization method described in JP-A-51-43424, etc., is known, in which continuous polymerization is immediately followed by continuous spinning without chipping. It is being

(Problem to be Solved by the Invention) However, in the continuous polymerization method, since condition fluctuations in the polymerization process and the spinning process affect each other, it is necessary to obtain uniform yarns or operate stably in each process. Highly accurate management must be carried out. Moreover, in composite spinning, since a plurality of polymers must be prepared, this problem becomes even more serious.

The present inventors previously proposed a method for efficiently producing multiple polymers (Japanese Patent Application No. 1-140821).

The present invention aims to solve the above-mentioned problems by further developing this proposal and applying it to a continuous polymerization method.

(Means for Solving the Problems) The present invention extracts a part of the oligomer in its state before being polymerized, adds a modifier to it, and produces multiple types of oligomers. This method is characterized in that after the oligomers are individually polymerized, they are immediately supplied to a single spinning head for composite spinning.

The present invention is applicable to various polymers that can be continuously polymerized, but since the continuous polymerization method is generally used in the production of polyester polymers, the following explanation will be made using terephthalic acid and ethylene glycol as monomers. An example will be given of the case where polyester is produced using the method.

As the modifier used in the present invention, known modifiers can be used, such as cationic dye dyeability, easy dyeability,
Flame retardant, easily soluble in alkali, hygroscopic and water absorbent, heat retention, moisture permeable and waterproof, antistatic and conductive, antifouling, antibacterial and aromatic, high heat shrinkability, elasticity, adhesiveness, building resistance, gloss, etc. Modifiers with various properties can be used, and specifically, for example, lower alkyl esters or aromatic esters such as phthalic acid, isophthalic acid, 5-metal sulponisophthalic acid, polyethylene glycol, lithium acetate, titanium oxide.

Examples include pigments and dyes.

Among these modifiers, fusion modifiers such as isophthalic acid, neopentyl glycol, cyclohexane dimetatool, etc. are particularly significant in the present invention, as will be described later.

Hereinafter, the case of composite spinning of polyester will be specifically explained using drawings.

In FIG. 1, first, terephthalic acid and ethylene glycol, which are used as monomers, are esterified in the first and second esterification tanks (7a) and (7b) to produce oligomers.

And like this, the esterification tank (7a), (7b)
Most of the oligomer esterified with
a), (lb), and (lc), and the oligomers are polymerized in order in these main polymerization tanks (la), (lb), and (lc).

On the other hand, in producing a modified polymer obtained by adding a modifier to polyester, the esterification tank (7a),
The oligomer esterified in (7b) is transferred to the main polymerization tank (
Flow path (2) leading to la), (lb), (lc)
A branch path (3) is provided via a valve (3a), and a portion of the oligomer is extracted through this branch path (3).
The oligomer thus extracted is guided to the depolymerization tank (4) as required. Although it is preferable to include a depolymerization step in order to alleviate the temperature drop in the polymer caused by the addition of a modifier and to perform the subsequent polymerization step efficiently, it is preferable to add isophthalic acid to produce a low melting point polyester. In some cases, this is not always necessary. In the depolymerization tank (4), a condenser (4a) is installed in the depolymerization tank (4) as a total reflux means (4a) for completely refluxing the oligomer extracted as described above.
) is connected, and the oligomer is depolymerized while being totally refluxed by this condenser (4a).

The oligomers thus depolymerized are then led to the first and second polymerization tanks (5a) and (5b) in this order, and polymerized in these polymerization tanks (5aL (5b)).

In addition, before the oligomer extracted through the branch path (3) is polymerized in the polymerization tanks (5a) and (5b) as described above, various modifiers are added to the extracted oligomer. The agent is added by means of an agent injection means (6).

Here, as a method in which various modifiers are added by the modifier injection means (6) before the oligomers extracted through the branch path (3) are polymerized in the polymerization tanks (5a) and (5b), For example, as shown in Fig. 1, there is a pipe (3b) that leads the oligomer to the depolymerization tank (4), a depolymerization tank (4), this depolymerization tank (4), and the first polymerization tank (5a).
and the first polymerization tank (5a).
Modifier supply ports (61a
), (61b), (61c), (61d)
are provided, and each of these modifier supply ports (61a) to (61
d) includes a method of supplying various modifiers to the extracted oligomer.

In addition, each modifier is usually supplied as an ethylene glycol solution, but as described above, it is supplied in the depolymerization tank (4).
In the case of a modifier with a high ethylene glycol content, a condenser (4a) is connected to the pipe (3b) that leads the oligomer to the depolymerization tank (4) and a modifier installed in the depolymerization tank (4). Quality agent supply port (61a).

It is also possible to mix smoothly by supplying from (61b).

In addition, each of the above-mentioned modifier supply ports (61a) to (61d)
As shown in Figure 2, in order to supply various modifiers to the
2aL (62b), (62c), (62d)
If various modifiers are housed inside, it is possible to add a plurality of additives and auxiliary agents. Each of these storage tanks (62a) to (6
2d) is preferably provided with a stirring means (64), and the various modifiers contained in the storage tanks (62a) to (62d) are stirred by the stirring means (64).

Then, the various modifiers contained in the storage tanks (62a) to (62d) are passed through the supply pipes (65) from the storage tanks (62a) to (62d), and ), each of the modifier supply ports (61a
) to (61d) are supplied with an appropriate amount of a suitable modifier.

Here, when talking about additives when manufacturing various modified polyesters, in the case of low melting point polyester, for example, 20 to 4.0 m o 1% of isophthalic acid, and in the case of alkali easily soluble polyester, for example, 5- Na sulfo-
4 to 6 bis(β-hydroxyethyl) isophthalate
In the case of cationic dyeable polyester, for example, about 2 to 3 mo I% of 5-Na sulfobis(β-hydroxyethyl) isophthalate may be added. Can be mentioned. The polyethylene terephthalate and modified polyester obtained as described above are immediately supplied to a spinning head using a gear pump or the like to carry out so-called direct spinning without undergoing any steps such as chipping.

In the present invention, in order to perform composite spinning of polyethylene terephthalate and modified polyester, it is preferable to use a composite spinning head that can composite two types of polymers with a single spinning head. Various types of such spinning heads are known, but in the case of low melting point polyester, one component has a core-sheath shape with a low melting point polyester as a sheath and polyethylene terephthalate as a core, and in the case of alkali easily soluble polyester, one component has a core-sheath shape with a core of polyethylene terephthalate. In the case of a cationically dyeable polyester having a shape that does not completely contain the above components, it is preferable to use a composite spinhead having a single fiber cross section such as a shape in which both components are randomly mixed.

Incidentally, the spinning may consist of a normal spinning process and a drawing/twisting process, but if it is further performed by a direct spinning/drawing method, it is possible to manufacture a composite fiber in which the process from polymerization to spinning is continuous.

(Function) Modified polymers deteriorate more significantly than normal polymers, and
Generally, there are more troubles in each process than with ordinary polymers. For example, in the case of low melting point polyester, after going through the chipping process, some fusion may already occur during the chip drying/crystallization process, fusion may occur near the inlet during chip extrusion, or feeding failure may occur.

In the present invention, since spinning is performed immediately after polymerization without going through a chipping process, the problem of dirt is completely eliminated.

Furthermore, when performing composite spinning, it is important to stably supply each component polymer, but in the case of the present invention, a part of the oligomer is extracted, a modifier is added, and the oligomer is returned to the original flow path. Because it is a closed path, there are extremely few disturbances.

(Example) Example 1 After esterifying terephthalic acid and ethylene glycol in the first and second esterification Wj (7a) and (7b), bisulfuric acid with an esterification rate of 90% or more was A part of β-human'oxyethyl terephthalate,
” 1. From the flow path (2) to the branch path (
3) and the second polymerization tank (
5a) (5b) was fed directly. -Meanwhile, isophthalic acid is stored in the first storage tank (62a) and the valve (62a) is stored.
6), the modifier was introduced into the modifier supply port (61a) through the supply pipe (65) and continuously supplied, while adjusting the addition amount to 25 mo1%.

The above oligomer to which isophthalic acid has been added is polymerized in the first and second polymerization tanks (5a) and (5b), its absolute viscosity is increased to 0.550, and the oligomer is immediately supplied to the composite spinning head. , isophthalic acid-added polymer is a sheath and polyethylene terephthalate is a core with a bonding ratio of 1:l,
1000m of 75d/8f composite fiber with sheath thickness of 9μ
The yarn was wound up at a speed of /min.

In this production process, the fused composite yarn could be stably produced without any fusion phenomenon of the low melting point polymer or poor feeding.

Example 2 After esterifying terephthalic acid and ethylene glycol in the first and second esterification tanks (7a) and <7b), the esterification rate of 9
A portion of 0% or more bis-β-hydroxyethyl terephthalate is guided from the flow path (2) to the branch path (3) via the valve (3a), and is passed through the branch path (3) to the depolymerization tank ( 4).

Here, a 5% by weight ethylene glycol solution of lithium acetate is stored as a modifier in the first storage tank (62a), and this modifier is fed into the supply pipe while being regulated by the valve (66). (65), the oligomer is passed through the depolymerization tank (
Modifier supply port (
61a), and the modifier was continuously supplied from this modifier supply port (61a).

In addition, in the second storage tank (62b), as a modifier,
A 35% ethylene glycol solution of 5-Na sulfobis(β-hydroxyethyl) isophthalate is accommodated, and the modifier is fed through the supply pipe (65) while being regulated by the valve (66) to the depolymerization tank (4). ) to the modifier supply port (61b) provided in the modifier supply port (61b).
1b) was made to be continuously supplied.

In addition, in the third storage tank (62c), as a modifier,
A 30% by weight ethylene glycol solution of titanium oxide is contained, and this modifier is connected to the depolymerization tank (4) and the first polymerization tank (5a) through the supply pipe (65) while adjusting it with the valve (66). The modifier is guided to the modifier supply port (61c) provided in the pipe (3C) between the
) so that it is supplied continuously.

Then, the oligomer of bis-β-hydroxyethyl terephthalate to which each modifier has been added from the modifier supply ports (61a) and (61b) is completely refluxed through the condenser (4a) and transferred to the depolymerization tank (4). After the depolymerization, further modifiers are added from the modifier supply port (61c), and the oligomers to which each modifier has been added in this way are
The mixture was polymerized in the second polymerization tanks (5a) and (5b), and its absolute viscosity was increased to 0.550.

The cationically dyeable polyester thus obtained and polyethylene terephthalate were immediately mixed into
After compounding through the spinning head described in Japanese Patent No. 366, that is, static kneading yarn having three elements, 2
50d/36f from 4 six-lobed cross-section metal, joining ratio 1:1
The fibers were discharged at a speed of 1,200 m/min and wound at a speed of 1200 m/min to obtain composite fibers in which both polymers were joined in a random shape for each single filament. Stable operation was also possible in this manufacturing process.

Example 3 After esterifying terephthalic acid and ethylene glycol in the first and second esterification tanks (7a) and (7b), the resulting esterification rate was 9.
A portion of 0% or more bis-β-hydroxyethyl terephthalate is guided from the channel (2) through the valve (3a) to the branch channel (3), and is passed through the branch channel (3) to the depolymerization tank (
4).

In this example, the first storage tank (
62a) contains a polyethylene glycol having an average molecular weight of 4000 heated with steam at 100 to 150°C to liquefy it as a modifier, and this modifier is
The oligomer is continuously supplied from the modifier supply port (61a) provided in the pipe (3b) leading to the depolymerization tank (4), and 5-Na sulfonate is supplied into the second storage tank (62b). - A 35% by weight ethylene glycol solution of bis(β-hydroxyethyl) isophthalene 1 to 1 is contained, and this modifier is supplied to the modifier supply port (61) provided in the depolymerization tank (4).
It was made to supply continuously from b).

In this way, the first and second storage tanks (62a) (62
The oligomer of bis-β-hydroxyethyl terephthalate supplied with each modifier from b) is transferred to a condenser (4
After being depolymerized in the depolymerization tank (4) under total reflux according to a), the oligomer is polymerized in the first and second polymerization tanks (5a) and (5b), and its absolute viscosity is reduced to 0. Raised it to 70.

The alkali easily soluble polyester and polyethylene terephthalate thus obtained were fed to a composite spinning head, and the alkali easily soluble polyester was formed into eight radial shapes.
Polyethylene terephthalate has a shape that complements this, and both are joined, 75d/25f, joining ratio 3.
(PET): 1200m/1 (easily soluble) composite fiber
The yarn was wound up at min.

Even in such a manufacturing process, it was possible to stably produce a dissolving and splitting type conjugate fiber.

(Effects of the Invention) According to the present invention, deterioration of the modified polymer and process defects during the production of composite fibers by the hatch method are eliminated. In addition, multiple polymers necessary for forming composite fibers can be stably supplied, and the combination of these polymers enables extremely stable operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the present invention, and FIG. 2 is a schematic diagram showing an example of a modifier supply route.

Claims (1)

[Claims] (1) In the state of the oligomer before polymerization, a part of this oligomer is extracted, a modifier is added to this to produce multiple types of oligomers, and after polymerizing each oligomer separately, immediately A method for producing composite fibers, which comprises supplying composite fibers to a single spinning head and performing composite spinning.