JPH0578978A - Production of fusion proofing and flame retardant polyester fiber - Google Patents

Abstract

PURPOSE:To obtain the title fiber having both of fusion proofing property and flame retardance by irradiating a polyester fiber containing a specific amount or more of phosphorus compound with electron beam and then providing a specific amount of specific monomer to the fiber. CONSTITUTION:A phosphorus compound, e.g. phosphorus-containing flame retardant material is melt and kneaded with a polyethylene terephthalate resin and the kneaded material is spun to afford 0.1-5wt.% of polyester fiber. Then the fiber is irradiated with electron beam and then a polymerizable monomer having <=200 molecular weight, e.g. (meth) acrylic acid, etc., or esters thereof are provided to the fiber and the monomer is polymerized and fixed so as to increase the fiber weight by >=7%. The fiber obtained by this treatment has fusion proofing performance and is excellent also in flame retardance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a flame-retardant polyester fiber which also has anti-melting properties.

[0002]

2. Description of the Related Art Researches on flame-retardant garments have been frequently conducted in the last few years, and the interest of general consumers is increasing considerably. The conventional proposals for flame-retardant fibers can be roughly classified into the following three types. (1) Flame-retardant by adding an inorganic or organic flame-retardant aid (2) Flame-retardant by adding a chemical containing phosphorus or halogen by post-processing (3) Phosphorus compound to polyester Copolymerized

However, although the flame-retardant polyester has advantages in productivity, processability, durability, etc., all of its self-extinguishing mechanism is due to melting and dropping, so these polyester fibers are actually used for clothing. When it was worn as a garment and the clothing was ignited, it caused serious burns due to the melting of the fibers.

Therefore, in order to improve the heat resistance of polyester, polyfunctional acrylates such as diallyl cyanurate, diallyl isocyanurate, triallyl cyanurate, triallyl isocyanurate and their dimers and trimers are used. A method has been proposed in which the film, sheet, or fiber obtained by melt-kneading in a polyester resin as a cross-linking agent is subjected to cross-linking by irradiation with ionizing radiation, but in this method, melting is completely prevented. Not only is there a problem in terms of performance, but also when the above-mentioned cross-linking agent is kneaded into a polymer to produce fibers, the viscosity is lowered and uniform fibers cannot be obtained. There was also the problem of occurrence of.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks and provides a polyester fiber having excellent flame retardancy, which is completely novel as a polyester fiber for clothing and has a fusion resistance. This is a technical issue.

[0006]

Means for Solving the Problems As a result of earnest research to solve the above problems, the present inventors have introduced an excellent anti-melting property by introducing into polyester a structure capable of suppressing the flow of molecular chains due to heat. The present invention has been achieved by finding that the property is obtained.

That is, the present invention has a phosphorus content of 0.1 to
After irradiating 5% by weight of polyester fiber with an electron beam, the weight of the fiber is increased by 7% or more by applying a polymerizable monomer having a molecular weight of 200 or less, and a method for producing a fusion-resistant flame-retardant polyester fiber. Is the gist. Hereinafter, the present invention will be described in detail.

Polyethylene terephthalate and polybutylene terephthalate can be generally mentioned as the polyester in the present invention, but isophthalic acid, sulfoisophthalic acid, azelaic acid, succinic acid, adipic acid, etc. may be copolymerized.

In the anti-melting flame-retardant polyester of the present invention, first of all, it is necessary to have self-extinguishing property,
To this end, the phosphorus content in the polyester is 0.1-
It should be in the range of 5% by weight. If the phosphorus content is less than 0.1% by weight, the flame-retardant effect is insufficient, and if the phosphorus content exceeds 5% by weight, the strength, productivity, dyeability, and texture are poor. This is not preferable because it causes problems.

As a method of incorporating phosphorus into the polyester fiber, there are a method of adding a phosphorus-based flame retardant to the polymer at the time of producing the fiber, a method of copolymerizing a phosphorus compound with the polymer itself, and the like. For example, in the method of adding a flame retardant to a polymer, a phosphoric acid amide condensate, an aliphatic phosphoric acid ester, an aromatic phosphoric acid ester, an alkoxyphosphazene, an aminophosphazene, a halogenated alkyl polyphosphate phosphonate, etc. It can be used as a flame retardant, and it can be obtained by melt-kneading the flame retardant and a polyester chip in a predetermined weight ratio to produce a master chip, and melt spinning the same by a conventional method. On the other hand, as a method for copolymerizing a phosphorus compound, a conventionally known polyester production method, for example, a polyester production method using a phosphorus-containing acid component and / or a glycol component as a third component at the time of polymerization of polyethylene terephthalate, polybutylene terephthalate, etc. The method of copolymerization may be a transesterification method, an esterification method, a polycondensation method, or the like.

The melting resistance of the polyester fiber of the present invention is
It is obtained by irradiating the phosphorus-containing polyester fiber obtained above with an electron beam and then adding a polymerizable monomer having a molecular weight of 200 or less. That is, in the present invention, it is necessary to suppress the flow of the polymer molecular chains constituting the polyester due to heat. For that purpose, first, the fiber substrate is irradiated with an electron beam to generate radicals even inside the polyester. After that, it is necessary to contact with the polymerizable monomer to cause matrix polymerization with sufficient polymerizable monomer inside the polymer. In the method of irradiating the fiber with the polymerizable monomer and then irradiating it with an electron beam, the polymerization of the monomer does not reach the inside of the polymer, and the anti-fusion effect cannot be obtained. Further, in the method in which the polymerizable monomer is exhausted inside the polymer by heat and then electron beam irradiation is performed to cause matrix polymerization, the exhaustion amount of the monomer is not sufficient.
It is not preferable because the expected anti-fusing effect cannot be obtained, and it becomes difficult to control the matrix polymerization.

In the present invention, the weight increase rate by the matrix polymerization of the polymerizable monomer is 7 with respect to the fiber weight.
% Or more, preferably 10% or more.

The polymerizable monomer preferably has a molecular weight of 200 or less, more preferably 150 or less. If this molecular weight exceeds 200, the monomer does not reach the inside of the polymer, and the anti-fusing effect becomes insufficient. Examples of the polymerizable monomer used here include compounds having an acidic group such as acrylic acid, methacrylic acid, itaconic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, their esters and acrylamide, and acrylonitrile. Examples thereof include acrylic acid derivatives, but are not limited to these.

The above polymerizable monomer is preferably used as an aqueous solution, but a solvent such as ethylene dichloride or monochlorobenzene may be used as a swelling agent. Examples of the method of applying the monomer include a usual method such as a dipping method and a spraying method, but the method is not limited to these and may be appropriately adopted. At this time, it is preferable that the applied monomer is in an activated state, and for example, the activated state of the monomer can be obtained by energy such as heat, microwaves or ultrasonic vibrations.

As the electron beam irradiation conditions, the acceleration voltage may be appropriately set according to the thickness of the target polyester fiber base material, but is generally 150 KV or more, 50
0KV or less is suitable. Regarding the irradiation dose, 5
Greater than or equal to Megarad (hereinafter referred to as Mrad) and less than or equal to 30Mrad is preferable. When the irradiation dose is less than 5 Mrad, the amount of radicals produced is small and sufficient matrix polymerization cannot be obtained.
If it exceeds Mrad, the physical properties of the fiber deteriorate, which is not preferable. The electron beam irradiation atmosphere preferably has an oxygen concentration of 500 ppm or less, and it is suitable to carry out under a nitrogen stream in order to obtain this condition.

[0016]

[Operation] As in the method of the present invention, 0.1 to 5% by weight of phosphorus
When the flame-retardant polyester fiber contained is irradiated with an electron beam and then a polymerizable monomer having a molecular weight of 200 or less is applied, matrix polymerization due to the polymerizable monomer occurs between the molecules, and the polyester fiber is suppressed in fluidity due to heat, As a result, the fiber has an anti-fusing property. Also, after irradiation with an electron beam, a low molecular weight polymerizable monomer having a molecular weight of 200 or less is imparted, so that the monomer quickly penetrates into the inside of the polymer and matrix polymerization proceeds sufficiently, and the fiber has an extremely excellent anti-melting property. As shown.

[0017]

EXAMPLES Hereinafter, the method for producing the anti-melting flame-retardant polyester fiber of the present invention will be specifically described with reference to the examples. The measurement and evaluation of the performance of the cloth in the examples were carried out by the following methods. (1) Flame retardance Afterflame and residual dust time were measured by the tension method of JIS L-1091 A-1 method (45 ° microburner method). The presence or absence of melt drop was determined by the JIS L-1091 D method (45 ° coil method). (2) Anti-fusing property The sample is placed horizontally, and the horizontally ignited cigarette is left on it for 5 seconds, and the presence or absence of a hole of 0.5 mm or more is checked for 15 seconds.
The number of occurrences of holes for each measurement was displayed. (3) Washing test method According to JIS L-1042 F-2 method. (4) Dry cleaning test method According to JIS L-1018 E-2 method.

Example 1 Cresyl diphenyl phosphonate (phosphorus-containing flame retardant) 7 per 100 parts by weight of polyethylene terephthalate resin
Using a chip obtained by melt-kneading parts by weight, polyester fibers 150d / 48f were obtained by a melt spinning method. At this time, the phosphorus content was 0.6% by weight.

A taffeta having a basis weight of 150 g / m ² was woven using the obtained polyester fiber as a warp. Then, after irradiating with an electron beam of 200 KV and 20 Mrad, it is immersed in an aqueous solution of acrylic acid (molecular weight 72) with a liquid temperature of 80 ° C. and a concentration of 30% for 15 minutes to carry out matrix polymerization to prevent the fusion prevention by the method of the invention. A flammable polyester taffeta was obtained. The weight increase rate at this time was 12.4%.

Example 2 The same polyester taffeta as used in Example 1 above was irradiated with an electron beam of 200 KV and 20 Mrad, and then a liquid temperature of 80 ° C. and a concentration of 40% ethylene glycol diacrylate (molecular weight 170). This was dipped in the aqueous solution for 20 minutes for matrix polymerization to obtain a fusion-resistant flame-retardant polyester taffeta according to the method of the present invention. The weight increase rate at this time is 11.8.
%Met.

Comparative Example 1 Using the same polyester taffeta as used in Example 1, 20
After irradiation with an electron beam of 0 KV and 10 Mrad, the liquid temperature was 80
By dipping in an acrylic acid aqueous solution having a concentration of 20% at a temperature of 15 ° C. for 15 minutes, matrix polymerization was performed to obtain a fusion-resistant flame-retardant polyester taffeta for comparison. The weight increase rate at this time was 5.3%.

Comparative Example 2 A polyester taffeta for comparison was obtained in the same manner as in Example 2 except that diethylene glycol diacrylate (molecular weight 214) was used as the polymerizable monomer. The weight increase rate at this time is 8.5%
Met.

Comparative Example 3 Cresyl diphenyl phosphonate (phosphorus-containing flame retardant) was added to 100 parts by weight of polyethylene terephthalate resin.
Using a chip obtained by melt-kneading 8 parts by weight, 150d / 48f of polyester fiber was obtained by a melt spinning method. At this time, the phosphorus content was 0.06% by weight.

Using the obtained polyester fiber as warp and weft, taffeta having a basis weight of 150 g / m ² was woven. The same matrix polymerization as in Example 1 was performed using this polyester taffeta to obtain a polyester taffeta for comparison. The weight increase rate at this time was 12.1%.

The performances of the present invention and the comparative woven fabric were measured and evaluated, and the results are shown together in Table 1.

[Table 1]

As is clear from Table 1, the polyester woven fabric produced by the method of the present invention had excellent melting resistance and flame retardancy. On the other hand, the woven fabrics of Comparative Examples 1 to 3 which did not satisfy the constituent requirements of the present invention did not satisfy either flame retardancy or anti-fusible property. In Comparative Example 2, the weight increase rate after the matrix polymerization was 8.5%, which exceeded 7%, but the molecular weight was large, so that the matrix polymerization did not proceed to the inside of the polymer and the anti-melting performance was satisfied. It was impossible.

[0027]

EFFECT OF THE INVENTION The polyester fiber obtained by the production method of the present invention has flame-retardant property with anti-fusing property, and when actually worn as clothing, prevents burns due to burning and melting of clothes. can do.

Claims (1)

[Claims] 1. A polyester fiber having a phosphorus content of 0.1 to 5% by weight is irradiated with an electron beam and then a polymerizable monomer having a molecular weight of 200 or less is added to increase the fiber weight by 7% or more. A method for producing a fusion-proof flame-retardant polyester fiber, which is characterized.