JPS626910A - Flame-resistant polyester fiber structure - Google Patents

Abstract

PURPOSE:The titled fiber structure, consisting of a polyethylene terephthalate based polyester and polyester containing a specific phosphorus compound and having good flame resistance and improved mechanical physical properties. CONSTITUTION:A polyester fiber structure, consisting of (A) a polyester of polyethylene terephthalate or consisting essentially thereof and (B) a polyester, containing a phosphorus compound having a group expressed by the formula (R is trifunctional organic group; the benzene ring may be substituted by a lower alkyl group or halogen) in an amount of >=50,000ppm expressed in terms of the weight of phosphorus atom and having >=0.4 intrinsic viscosity, containing 500-35,000ppm expressed in terms of the weight of the phosphorus atom and having >=0.5 intrinsic viscosity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a polyester fiber structure having flame resistance.

(Prior Art) Generally, polyester, especially polyethylene terephthalate, has excellent mechanical and chemical properties, and is used for clothing,
It is widely used as a fiber for industrial purposes.

Incidentally, in recent years, there has been an increasing demand for synthetic fibers to be flame resistant from the perspective of fire prevention, and polyester fibers in particular are used in large quantities for clothing, car vents, curtains, vehicle seats, etc., so there is a need for countermeasures. Establishment is urgently needed.

Conventionally, various methods for imparting flame resistance to polyester have been proposed, and a method of incorporating a phosphorus compound into polyester is said to be effective.

Among these, a method using a phosphinic acid compound as a phosphorus compound is considered to be a preferable method2.
Publication No. 3-128175 states that a flocculent polymer compound using a phosphinic acid compound and having a molecular weight of 1,000 to e, ooo is effective as a flame retardant for thermoplastic resins containing polyester.

(Problems to be Solved by the Invention) However, the flame retardant proposed in the above-mentioned publication does not have fiber-forming ability when used alone, and when added to polyester to produce fiber, there is a problem that the physical properties are significantly reduced. However, it was not suitable as a flame retardant for producing fibers.

The present invention aims to provide a polyester fiber structure that has good flame resistance and excellent physical properties.

(Means for Solving the Problems) The present invention achieves the above objects, and the gist thereof is as follows.

Polyethylene terephthalate or a polyester (A) containing polyester as a main component and a phosphorus compound having a group represented by the following formula were added to 50,000 pp++ as the weight of phosphorus atoms.
polyester (B) containing 500 to 35 phosphorus atoms by weight and having an intrinsic viscosity of 0.4 or more.
．． A flame-resistant polyester fiber structure containing OOOppo+ and having an intrinsic viscosity of 0.5 or more.

÷ Occupation + (R is a trivalent organic group, and the benzene ring may be substituted with a lower alkyl group or a halogen.) In the present invention, the polyester (A) is polyethylene terephthalate and a copolymer mainly composed of this. It is a polymerized polyester, and the copolymerized components include isophthalic acid, 4-oxybenzoic acid,
5-Sodium sulfoisophthalic acid, adipic acid, trimellitic acid.

Diethylene glycol, propylene glycol.

Examples include 1,4-cyclohexane dimetatool, 1,4-butanediol, and pentaerythritol.

In the present invention, the content of the phosphorus compound in the polyester (B) must be 50.000 ppm or more as the weight of phosphorus atoms. If an attempt is made to contain enough phosphorus atoms to provide the polyester (A), the amount of polyester (A) will be relatively small, and the physical properties of the polyester fiber structure will deteriorate, which is inappropriate.

In addition, polyester (B) needs to have an intrinsic viscosity of 0.4 or more; if it is less than 0.4, fiber formation is difficult when used alone, and it is used in combination with polyester (A) having a sufficiently high intrinsic viscosity. Polyester (A
), and it is not possible to obtain a fiber structure with excellent physical properties such as 1 strength without reducing the flame resistance.

In addition, it is necessary to adjust the content of the phosphorus compound in the fiber structure to 500 to 35,000 ppm as the weight of phosphorus atoms; if it is less than this range, the flame resistance will be insufficient, and if it is too much, the physical properties will deteriorate. or decrease.

This is undesirable because it may impair spinning properties.

Furthermore, in order to provide the WA fibrous structure with excellent physical properties such as strength, it is necessary to ensure that the intrinsic viscosity of the fiber structure is 0.5 or more, and in order to satisfy this requirement, polyester ( The intrinsic viscosity and usage ratio of A) and (B) are selected. However, if the intrinsic viscosity of the polyester (B) is made too high, the melt viscosity will increase and the silk-spinning properties will deteriorate.

It is preferable that the intrinsic viscosity of the polyester (A) is higher than that of the polyester (B), but that the intrinsic viscosity of the polyester (B) is not too high.

In the present invention, the phosphorus compound does not need to be contained in a single fiber, and the above-mentioned content does not need to be contained in a single fiber, but in the entire polyester fiber structure (referring to multifilament, tow, stable, spun yarn, woven fabric, nonwoven fabric, etc.). It suffices if the content is such that the amount is the same.

In the present invention, the phosphorus compound used in the production of polyester (B) is preferably a metal compound represented by a linear formula.

X'0-Ar-OX" (Ar is an aromatic group y+) (2 represents a hydrogen atom or an ester-forming functional group) With a dicarboxylic acid component such as isophthalic acid, esterification method, transesterification method, acid exchange method,
It is obtained by reacting with an ester addition method, double condensation method, etc. to obtain a polyester having an intrinsic viscosity of 0.4 or more.

To obtain polyester with an intrinsic viscosity of 0.4 or more -, (
It is preferable to use a compound in which 1,Xt is an ester-forming functional group.

Specific examples of the ester-forming functional group of Xl and Xl are 2
Examples include:

-CR', -(R"O), H.

(R' is a hydrogen atom or a lower alkyl group, pt is a lower alkylene group, m is an integer of 1 to 20, and n is an integer of O to 20.) The above phosphorus compound is 9.10-dihydro-9-oxa-10 - Phosnophenanthrene-10-oxide (abbreviated as IC8), p-benzoquinone, 1,4-naphthoquinone, 0-benzoquinone.

By heating and reacting quinones such as 2.6-naphthoquinone and 4,4-diphenoquinone in a solvent such as ethyl cellosolve, a compound in which xt and xz become H is obtained, and if necessary, this part can be added to Obtained by introducing an ester-forming group.

For example, a reaction product of HCA and quinones and a corresponding carboxylic acid anhydride may be heated to react, or an alkali metal salt of a reaction product of HCA and quinones may be reacted with alkylene carbonate, alkylene oxide, polyalkylene oxide, or their mono- or The above-mentioned ester-forming group can be introduced by reacting with diglycidyl ether or epihalohydrin.

In the present invention, the method for producing the polyester fiber structure is not particularly limited, but specific examples include the following method.

■A method in which polyester (A) fibers are coated with polyester (B) dissolved in an appropriate solvent.

■ A mixing method during spinning, in which polyesters (A) and (B) are mixed at any time until the spinning is completed, the fibers are spun, and the polyesters are stretched.

■Polyester (A) and (B) are composite-spun into so-called side-by-side, sea-island, and core-sheath types.

A composite spinning method that involves stretching.

■Polyester (A) and (B) are spun separately.

A blending method during spinning that involves doubling and winding the yarn.

■Stretch blending method in which polyester (A) fibers and polyester (B) fibers are blended during stretching.

■A method of mixing and knitting polyester (A> fibers) and polyester (B) fibers during 9 knitting operations.

■Polyester (A) staples and polyester (B)
) is mixed with stable during spinning.

In the present invention, the polycondensation reaction when producing the polyester used for producing the polyester fiber structure is 0.0
260-310℃ under reduced pressure of about 1-10mmHg,
Preferably, the reaction is carried out at a temperature of 275 to 290°C until a predetermined degree of polymerization is obtained.

The 9-polycondensation reaction is carried out in the presence of a catalyst, and the catalyst is antimony, which has been commonly used in the past.

Metal compounds such as titanium, germanium, zinc, tin, and cobalt and organic sulfonic acid compounds such as sulfosalicylic acid and 0-sulfobenzoic anhydride are preferably used. In addition, since the tin compound serves as a catalyst for both the esterification reaction and the polycondensation reaction, it may be added in the step of the esterification reaction. The amount of the catalyst added is 1X10-5 to 1x10-'' mol, preferably 5X10-' to 5X10-' mol, more preferably 1X10-'' to 1 mol of acid component constituting the polyester.
A suitable range is 10-' to 3X10-' moles.

Note that in the present invention, stabilizers such as hindered phenol compounds, cobalt compounds, and fluorescent agents are used.

Additives such as color improvers such as dyes and pigments such as titanium dioxide may also be present.

The spun fibers are drawn and heat treated as necessary, either continuously or in a separate process, but at t4! It may be subjected to higher-order processing such as shrinkage processing and treatment with a chemical solution.

(Function) The reason why the polyester fiber structure of the present invention exhibits excellent flame resistance and good physical properties is not clear.

When in contact with flame, the phosphorus compound with phosphinic acid residues accelerates the thermal decomposition of the polyester, promoting melting and falling.At the same time, since it is not simply a polyester copolymerized with a phosphorus compound, there is no drop in melting point or strength. This is thought to be due to the fact that undesirable phenomena such as gelation can be minimized.

(Example) Next, the present invention will be described with reference to examples.

In addition, the characteristic values etc. in the Examples were measured or evaluated as follows.

Intrinsic viscosity [η] Measured at a temperature of 20.0° C. using an isobaric mixture of phenol and tetrachloroethane as a solvent.

Melting point using a PerkinElmer DSC-2 differential calorimeter,
Measurement was performed at a heating rate of 20°C/min.

Softening point Using an automatic melting point measuring machine 'gtN' manufactured by Mettler, two fibers were placed across each other on a hot stage under a microscope, and the temperature was raised at a rate of 2°C/min, causing the intersection of the fibers to deform and melt. The temperature at which the temperature reached was determined.

The content of phosphorus atoms was quantified by the Gay light X cotton method. ([Phosphorus content] indicates - as the weight of phosphorus atoms.) Flame resistance The yarn obtained by spinning and drawing according to the conventional method is made into a tubular knitted fabric, and the Ig is rolled into a length of 10.0 cm. Insert it into a wire coil with a diameter of On+m, hold it at a 45 degree angle, ignite it from the bottom end with a micro burner (caliber 0.64n+n+), and repeat the ignition if the fire is extinguished by moving the fire source away.

Find the number of ignitions required until all the samples burn out, and
It is expressed as the number of ignitions (denoted as the number of flame contacts) for each sample.

Ignitability Evaluation was made on the following four levels.

◎: Will not ignite until 30 seconds after contact with flame.

○: Ignition occurs 15 to 30 seconds after flame contact.

Δ: Ignition occurs 5 to 15 seconds after flame contact.

×: Ignition occurs within 5 seconds after contact with flame.

Example 1 In an esterification reaction tank containing an esterification reaction product (Blll!T) of terephthalic acid and ethylene glycol, the molar ratio t:i of terephthalic acid and ethylene glycol was
6 slurry was continuously supplied at 250°C.

The reaction was carried out at 0.05 kg/cJ G with a residence time of 8 hours.

BHI with 95% reaction rate! T was continuously obtained, 2XlO-' mol of antimony trioxide was added thereto as a catalyst per 1 mol of the acid component constituting the polyester, the temperature was raised to 280°C, and polycondensation was carried out under reduced pressure to obtain [η] 0 .75 of polyethylene terephthalate (PI!T) was obtained.

On the other hand, a reaction product (PB
By reacting Q・1(CA) with slightly excess acetic anhydride, P
BQ ・Diacetate phosphorus compound to HC (melting point 1
47.6-148.9°C).

This phosphorus compound, 0.5 times the mole of terephthalic acid, and 0.5 times the mole of terephthalic acid.
Using 5 times the mole of isophthal as a catalyst and using 3 x 10-' mol of dimethyltin maleate per 1 mol of the acid component, the reaction was carried out for 4 hours under a nitrogen stream at 270°C, and then an additional 3
The reaction was carried out for 1.5 hours at 0 Torr and for 4 hours at 1 Torr to obtain a phosphorus-containing polyester having a phosphorus content of 70.500 ppm and [η] of 0.58.

The total phosphorus content of the above PET and phosphorus-containing polyester is approximately 7
．． Mix and melt-spun to give OOOppm.

Polyester fibers were obtained by stretching.

Table 1 shows the characteristic values of the obtained fibers.

Examples 2-4. Comparative Examples 1 to 3 Type and amount of phosphorus compound added, PI! Table 1 shows the results obtained in the same manner as in Example 1 except that [η] of T was changed. (In Table 1, OBO・IICA and N-guchi・
HCA indicates those using 0-benzoquinone and 1,4-naphthoquinone in place of p-benquinone, respectively. ) Comparative Example 4 PBQ・HC obtained by the same method as described in Example 1
After reacting A with a slight excess of ethylene carbonate, it was charged into a polymerization tank together with the BIIET, and dimethyltin maleate was added as a catalyst at 2×1 per mole of acid component.
0-'mol was added and the temperature was raised to 280°C.

Reacted under reduced pressure, phosphorus content 7,050 ppm,
A phosphorus-containing polyester with (η) of 0.49 was obtained.

Table 1 shows the characteristic values of the polyester fiber obtained by melt-spinning and drawing this phosphorus-containing polyester.

Table 1 Example 5 PUT of Example 1 and phosphorus-containing polyester in a weight ratio of 4
A composite fiber (core/sheath weight ratio of 1/l) was produced by a conventional method using a mixture of PET as a core and a PET as a sheath (weight ratio of core/sheath of 1/l).

Table 2 shows the characteristic values of the obtained fibers.

Example 6 A multifilament made of a mixture of PliT of Example 1 and phosphorus-containing polyester at a weight ratio of 4:1 and P[! A mixed fiber yarn of 75d/36f in which multifilament consisting of T was mixed equally was obtained by a drawing blending method.

Table 2 shows the characteristic values of the obtained mixed fiber yarn.

Example 7 Stable and PE made of a mixture of PliT of Example 1 and phosphorus-containing polyester at a weight ratio of 4:1
Stable consisting of T was mixed in equal amounts with filaments, and then a roving machine and a spinning machine were used in I to obtain a spun yarn.

Table 2 shows the characteristic values of the obtained spun yarn.

Table 2 Note: The Nilin content is approximately 7,000 ppm in all cases.

(Effects of the Invention) According to the present invention, it is possible to stably produce a high-performance polyester fiber structure that exhibits excellent flame resistance without deteriorating the physical properties or spinning properties of polyester.

Claims (1)

[Claims] (1) Polyethylene terephthalate or a polyester (A) containing polyester as a main component and a phosphorus compound having a group represented by the following formula, in an amount of 50,000 p as the weight of phosphorus atoms.
pm or more and has an intrinsic viscosity of 0.4 or more, and contains 500 to 3 phosphorus atoms by weight.
A flame-resistant polyester fiber structure containing 5,000 ppm and having an intrinsic viscosity of 0.5 or more. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (R is a trivalent organic group, and the benzene ring may be substituted with a lower alkyl group or halogen.)