JPH0635686B2 - Flame resistant polyester fiber structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flame-resistant polyester fiber structure.

(Prior Art) Generally, polyester, especially polyethylene terephthalate, has excellent mechanical and chemical properties,
Widely used as a fiber for industrial use.

By the way, in recent years, there has been an increasing demand for flame resistance of synthetic fibers from the viewpoint of fire prevention. In particular, polyester fibers are used in large amounts in clothes, carpets, curtains, vehicle seats, etc. The establishment is urgent.

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

Among them, the method of using a phosphinic acid compound as the phosphorus compound is considered to be a preferable method, and is disclosed in, for example, JP-A-53
-128175 discloses that a linear polymer compound using a phosphinic acid compound and having a molecular weight of 1,000 to 8,000 is effective as a flame retardant for a thermoplastic resin containing polyester.

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

The present invention is intended to provide a polyester fiber structure having good flame resistance and excellent physical properties.

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

A polyester using polyethylene terephthalate or a polyester (A) containing the same as a main component and a phosphorus compound represented by the following formula as at least a part of a diol component, containing 50,000 ppm or more by weight of a phosphorus atom, Consists of polyester (B) with a viscosity of 0.4 or more, contains phosphorus atoms of 500 to 35,000 ppm by weight, and has an intrinsic viscosity of 0.5.
A flame-resistant polyester fiber structure characterized by the above.

(Ar is an aromatic group, X ¹ and X ² are ester-forming functional groups, and the benzene ring may be substituted with a lower alkyl group or halogen.) In the present invention, the polyester (A) is polyethylene terephthalate and It is a copolyester mainly composed of, and as the copolymerization component, isophthalic acid, 4-oxybenzoic acid, 5-sodium sulfoisophthalic acid, adipic acid, trimellitic acid, diethylene glycol, propylene glycol, 1,4-cyclohexanediene methanol,
Examples include 1,4-butanediol and pentaerythritol.

In the present invention, the content of the phosphorus compound in the polyester (B) is required to be 50,000 ppm or more as the weight of the phosphorus atom, and if the content of the phosphorus compound is less than this, the flame resistance in the fiber structure is improved. When it is attempted to contain sufficient phosphorus atom to impart the polyester (A),
It is not appropriate because the amount of styrene will decrease and the physical properties of the polyester fiber structure will deteriorate.

In addition, the polyester (B) must have an intrinsic viscosity of 0.4 or more. If it is less than 0.4, it is difficult to form fibers by itself, and when it is mixed with the polyester (A) having a sufficiently high intrinsic viscosity, it is used. It is not possible to obtain a fiber structure having excellent physical properties such as strength without lowering the intrinsic viscosity of the polyester (A) and reducing flame resistance.

In addition, it is necessary that the phosphorus compound content of the fiber structure is 500 to 35,000 ppm with the weight of phosphorus atoms. If it is less than this range, the flame resistance becomes insufficient, and if it is too large, the physical properties decrease. Undesirably, or the yarn formability is impaired.

Further, in order to give the fiber structure excellent physical properties such as strength, it is necessary that the intrinsic viscosity of the fiber structure be 0.5 or more. To satisfy this requirement, polyester (A) and The intrinsic viscosity and the usage ratio of (B) are selected. However, if the intrinsic viscosity of the polyester (B) is made too high, the melt viscosity becomes high and the spinnability deteriorates. Therefore, the intrinsic viscosity of the polyester (A) should be made higher.
The intrinsic viscosity of polyester (B) should not be too high.

In the present invention, the phosphorus compound does not need to be contained in a single fiber, and has the above content as a whole in the polyester fiber structure (multifilament, tow, staple, spun yarn, woven fabric, knitted fabric, nonwoven fabric, etc.). So long as it is contained.

The polyester (B) comprises the above-mentioned phosphorus compound and a dicarboxylic acid component such as terephthalic acid and / or isophthalic acid and, if necessary, a diol component such as ethylene glycol, by an esterification method, an industrial exchange method, an acid exchange method, It can be obtained by reacting by ester addition method, polycondensation method, etc. to obtain a polyester having an intrinsic viscosity of 0.4 or more.

Specific examples of the ester-forming functional group of X ¹ and X ² include:
Some examples are as follows.

(R ¹ is a hydrogen atom or a lower alkyl group, R ² is a lower alkylene group, m is an integer of 1 to 20, and n is an integer of 0 to 20.) The phosphorus compound as described above is represented by 9,10-dihydro-9-oxa. -10-phosphaphenanthrene-10-oxide (abbreviated as HCA) and quinones such as p-benzoquinone, 1,4-naphthoquinone, o-benzoquinone, 2,6-naphthoquinone, 4,4-diphenoquinone and ethyl cellosolve by reaction heated in a solvent, wherein ^X 1, ^{X 2} is H
To obtain an ester-forming group in this portion, if necessary.

For example, a reaction product of HCA and a quinone and a corresponding carboxylic acid anhydride are heated to react with each other, or an alkali metal salt of a reaction product of HCA and a quinone and an alkylene carbonate, an alkylene oxide, a polyalkylene oxide or a mono or The ester-forming group as described above 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 the following method may be mentioned as a specific example.

A method of coating fibers of polyester (A) with polyester (B) dissolved in a suitable solvent.

A mixing method during spinning in which polyesters (A) and (B) are mixed and spun at an arbitrary time until completion of spinning and then stretched.

A composite spinning method in which polyesters (A) and (B) are composite-spun into so-called side-by-side type, sea-island type, core-sheath type, and stretched.

Polyester (A) and (B) are spun separately, spun together and wound up.

A drawing and mixing method in which fibers of polyester (A) and fibers of polyester (B) are mixed during drawing.

A method in which fibers of polyester (A) and fibers of polyester (B) are woven and knitted during knitting and knitting.

A mixed spinning method in which staples of polyester (A) and staples of polyester (B) are mixed during spinning.

In the present invention, the polycondensation reaction in producing the polyester used for producing the polyester fiber structure is 0.01 to 1
260 ~ 310 ℃, preferably 275 ~ under reduced pressure of 0mmHg
It may be carried out at a temperature of 290 ° C until a desired degree of polymerization is obtained.

The polycondensation reaction is carried out in the presence of a catalyst, and as the catalyst, metal compounds such as antimony, titanium, germanium, zinc, tin, and cobalt, which have been conventionally used, sulfosalicylic acid, o-sulfobenzoic anhydride, etc. The organic sulfonic acid compound of is preferably used. 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 1 for 1 mol of the acid component constituting the polyester.
× 10 ^-5 to 1 × 10 ^-3 mol, preferably 5 × 10 ^{-5 to} 5 × 10 ^-4
It is suitable that the amount is more preferably 1 × 10 ^{−4 to} 3 × 10 ⁻⁴ mol.

In the present invention, additives such as stabilizers such as hindered phenol compounds, cobalt compounds, fluorescent agents, color improving agents such as dyes, and pigments such as titanium dioxide may coexist.

The spun fiber is drawn or heat-treated continuously or in another step, if necessary, but may be subjected to higher-order processing such as crimping or treatment with a chemical solution.

(Operation) Although the reason why the polyester fiber structure of the present invention exhibits excellent flame resistance and good physical properties is not clear, a phosphorus compound having a phosphinic acid residue promotes thermal decomposition of polyester during flame contact, It is thought that this is because the melt-fall is promoted, and at the same time, the polyester does not consist of a polyester copolymerized with a phosphorus compound, so that the melting point and the strength are not deteriorated, and undesirable phenomena such as gelation can be minimized.

EXAMPLES Next, the present invention will be described with reference to examples.

The characteristic values and the like in the examples are measured or evaluated as follows.

Intrinsic viscosity [η] Using an equal weight mixture of phenol and ethane tetrachloride as a solvent, the temperature was measured at 20.0 ° C.

Melting point Using a DSC-2 type differential calorimeter manufactured by Perkin Elmer, the temperature was measured at a temperature rising rate of 20 ° C / min.

Softening point Using an automatic melting point measuring device manufactured by METTLER, place two fibers on a hot stage under a microscope so that they cross each other.
The temperature was raised at a rate of ° C / min, and the temperature at which the fiber intersection was deformed and fused was determined.

Phosphorus atom content Quantitatively determined by fluorescent X-ray method. (“Phosphorus content” refers to the amount of phosphorus atoms by weight.) Flame resistance A yarn obtained by spinning and drawing according to a conventional method is made into a tubular knitted fabric, and 1 g of the yarn is rolled into a length of 10.0 cm to obtain a 10.0 mm diameter. Insert into wire coil, hold at 45 degree angle, ignite with micro burner (caliber 0.64mm) from the lower end, repeat ignition when extinguishing by moving away from the fire source until all samples burn out The number of ignitions required for was calculated and expressed as the number of ignitions (referred to as the number of flame contact) for 5 samples.

Ignition property The following four grades were evaluated.

⊚: Ignition does not occur until 30 seconds or more after flame contact.

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

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

X: Ignition occurs within 5 seconds after flame contact.

Example 1 A slurry having a molar ratio of terephthalic acid and ethylene glycol of 1: 1.6 was continuously fed to an esterification reaction tank containing an esterification reaction product (BHET) of terephthalic acid and ethylene glycol at 250 ° C., 0.05. Dwell time of 8 in kg / cm ² G
BHET with a reaction rate of 95% is continuously obtained by reacting as time,
2 × 10 ^-4 mol of antimony trioxide as a catalyst was added to 1 mol of the acid component constituting the polyester, and the mixture was added at 280 ° C.
The temperature was raised to 1, and polycondensation was performed under reduced pressure to obtain [η] 0.75 polyethylene terephthalate (PET).

On the other hand, HCA and p-benzoquinone were reacted in an ethyl cellosolve solvent at a temperature of 90 ° C (PBQ · HCA) and a slight excess of acetic anhydride was reacted to react with the phosphorus compound of the diacetate form of PBQ · HCA ( A melting point of 147.6-148.9 ° C. was obtained.

This phosphorus compound was reacted with 0.5 times mole terephthalic acid and 0.5 times mole isophthal as a catalyst and dimethyltin maleate was used in an amount of 3 × 10 ^-4 moles per 1 mole of the acid component, and reacted for 4 hours under a nitrogen stream at 270 ° C. After an additional 30 torr, 1.5
The reaction time is 1 torr for 4 hours and the phosphorus content is 70,500 pp
A phosphorus-containing polyester having an [η] of 0.58 at m was obtained.

The above PET and phosphorus-containing polyester have a phosphorus content of about 7,000
The mixture was mixed so as to be ppm, melt-spun, and stretched to obtain a polyester fiber.

The characteristic values of the obtained fiber are shown in Table 1.

Examples 2 to 4, Comparative Examples 1 to 3 Table 1 shows the results obtained in the same manner as in Example 1 except that the type and addition amount of the phosphorus compound and PET [η] were changed.
(In Table 1, OBQ · HCA and NQ · HCA are o-benzoquinone and 1,4 instead of p-benquinone, respectively.
-Indicates using naphthoquinone. Comparative Example 4 After reacting PBQ · HCA obtained by the same method as described in Example 1 with a slight excess of ethylene carbonate,
It was charged into a polymerization tank together with BHET, and 2 × 10 ^-4 mol of dimethyltin maleate as a catalyst was added to 1 mol of the acid component, the temperature was raised to 280 ° C, and the reaction was conducted under reduced pressure to obtain a phosphorus content of 7,05
A phosphorus-containing polyester containing 0 ppm and [η] 0.49 was obtained.

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

Example 5 The PET of Example 1 and the phosphorus-containing polyester were mixed in a weight ratio of 4:
A composite fiber (core / sheath weight ratio 1/1) in which a mixture of 1 was used as a core and PET was used as a sheath was produced by a conventional method.

The characteristic values of the fibers obtained are shown in Table 2.

Example 6 The PET of Example 1 and the phosphorus-containing polyester were used in a weight ratio of 4:
Multifilament consisting of a mixture of 1
70 mixed with equal amount of multifilament made of PET
A mixed fiber of d / 36f was obtained by the stretch mixing method.

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

Example 7 The PET of Example 1 and the phosphorus-containing polyester were used in a weight ratio of 4:
The staples made of a mixture of 1 and the staples made of PET are kneaded and mixed in an equal amount, and then a roving machine,
A spun yarn was obtained through a spinning machine.

The characteristic values of the obtained spun yarn are shown in Table 2.

(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 and yarn-forming properties of polyester.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location D01F 8/14 B 7199-3B D02G 3/02 (56) Reference JP-A-59-59916 (JP, A) JP-A-55-60524 (JP, A) JP-B 44-2111 (JP, B1) JP-B 58-18447 (JP, B2) JP-B 56-27610 (JP, B2)

Claims (1)

[Claims] 1. A polyester comprising polyethylene terephthalate or a polyester (A) containing the same as a main component and a phosphorus compound represented by the following formula as at least a part of a diol component, wherein the phosphorus atom is 50,000 ppm by weight. A flame-resistant polyester fiber structure comprising the above-mentioned polyester (B) having an intrinsic viscosity of 0.4 or more, containing phosphorus atoms in an amount of 500 to 35,000 ppm by weight, and having an intrinsic viscosity of 0.5 or more. (Ar is an aromatic group, X ¹ and X ² are ester-forming functional groups, and the benzene ring may be substituted with a lower alkyl group or halogen.)