JP2015224412A - Modification method of polyester fiber and polyester fiber for carpet and carpet obtained by the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a cross-linked polyester fiber which is improved further in compression recovery while retaining excellent dimensional stability, strength, durability, heat resistance and antifouling properties of polyester fibers and a polyester carpet reduced in settling.SOLUTION: A modification method of polyester fibers comprises impregnating a polyester fiber with a compound having at least two unsaturated bonds and introducing a cross-linked structure into the polyester fibers by irradiation of an electron beam to obtain a cross-linked polyester fiber good in compression recovery. A polyester carpet reduced in settling is also provided.

Description

  The present invention relates to a technique for improving carpet sagability in a carpet using polyester fibers.

  The carpet using the polyester fiber is required to be improved because the carpet is inferior to the carpet using the nylon fiber. For this reason, Patent Document 1 discloses a method of improving carpet sagability by alternately arranging polyester yarns and nylon yarns in the gauge direction.

  Further, in Patent Document 2, a method for producing a carpet in which a low-melting yarn B is wound around a polyester yarn A and heated to a temperature at which only the yarn B is fused to form a carpet with less hair loss and sag. Is disclosed.

However, these techniques are effective as techniques for compensating for the disadvantages of the polyester fibers, but they do not improve the essence of the polyester fibers, and improvements have been demanded.
JP2013-248322A JP2009-189752

  The present invention has been made in view of such technical background, and its purpose is to retain the excellent dimensional stability, strength, durability, heat resistance, antifouling property, etc. of the polyester fiber. The object is to produce a cross-linked polyester fiber with good compression recovery and to obtain a polyester carpet with less sag.

  As a result of intensive studies to solve such problems, the present inventor impregnates a polyester fiber with a compound having at least two unsaturated bonds and irradiates an electron beam, thereby forming a crosslinked structure in the polyester fiber. It was introduced, a cross-linked polyester fiber having good compression recovery property was produced, and it was found that a polyester carpet with less sag could be obtained, and the present invention was achieved. The present invention provides the following means.

  [1] A step of impregnating a polyester fiber with a compound having at least two unsaturated bonds and a step of introducing a crosslinked structure into the polyester fiber by subjecting the impregnated polyester fiber to an electron beam irradiation treatment A process for producing a cross-linked polyester fiber characterized by

  [2] The method described in 1 above, wherein in the step of impregnating the compound having at least two unsaturated bonds, the compound having at least two unsaturated bonds is impregnated in a state of being dispersed in water. Of producing a cross-linked polyester fiber.

  [3] The method for producing a crosslinked polyester fiber as described in the above item 1 or 2, wherein the step of impregnating the compound having at least two unsaturated bonds is carried out under high pressure conditions.

  [4] The above items 1 to 3, wherein the impregnated polyester fiber is subjected to an electron beam irradiation treatment to introduce a crosslinked structure into the polyester fiber, and the electron beam irradiation treatment is performed in an atmosphere having an oxygen concentration of 500 ppm or less. The method for producing a crosslinked polyester fiber according to any one of items 3

  [5] A step of impregnating a polyester fiber with a compound having at least two unsaturated bonds, a step of introducing a crosslinked structure into the polyester fiber by subjecting the impregnated polyester fiber to an electron beam irradiation, A method for producing a crosslinked polyester fiber, comprising a step of heating an electron beam irradiation-treated polyester fiber to a glass transition point or higher.

  [6] A cross-linked polyester fiber for a carpet produced by the method for producing a cross-linked polyester fiber described in 1 to 5 above and a carpet thereof.

  In the invention of [1], a sufficient cross-linked structure cannot be introduced into a polyester fiber by simply irradiating the polyester fiber with an electron beam, but irradiation is performed after impregnating a compound having at least two unsaturated bonds. Thus, introduction of a crosslinked structure can be promoted. For example, materials such as polyethylene generate more radicals when irradiated with an electron beam than polyester, and a sufficient cross-linking structure is introduced simply by irradiating an electron beam. Therefore, it is necessary to impregnate at least a compound having two or more unsaturated bonds.

  In the invention [2], since water is used as a medium, it is not necessary to use a dangerous organic solvent or the like, and safe processing can be achieved.

  In the invention of [3], the compound is impregnated into the fiber in a state where pressure is applied. Therefore, the compound is injected into the inside of the fiber, and a large amount of the compound can be injected into the fiber. Moreover, by injecting into the fiber, the compound does not bleed out after processing and can be stabilized.

  In the invention of [4], since the impregnated polyester fiber is subjected to an electron beam irradiation treatment to introduce a crosslinked structure into the polyester fiber, the electron beam irradiation treatment is performed in an atmosphere having an oxygen concentration of 500 ppm or less. A sufficient amount of the cross-linked structure is efficiently introduced without the activity of the radical activated by 1 disappearing in a short time.

  The invention of [5] includes a step of heating the electron-irradiated polyester fiber to a glass transition point or higher, so that the reactivity in the amorphous region of the polyester fiber is increased and the formation of a crosslinking reaction is further promoted. Can do.

  In the invention of [6], since the carpet is a cross-linked polyester fiber for carpet produced by the method for producing a cross-linked polyester fiber described in 1 to 5 above and its carpet, many cross-linked structures are formed in the vicinity of the surface of the polyester fiber. When the polyester fiber is used as a carpet pile, the carpet is improved mainly in the vicinity of the surface to which the most force is applied, and the compression recovery property is improved.

  Examples of the polyester fiber in the present invention include polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. As a form of processing, the yarn may be continuously processed in a non-tensioned state, but it is efficient and preferable to process it in a batch manner while being wound around a bobbin.

  Examples of the compound having at least two unsaturated bonds include triallyl isocyanurate, triallyl cyanurate, diallyl isocyanurate, divinylbenzene, triethylene glycol diacrylate, and the like. is not.

  First, in the step of impregnating a compound having at least two unsaturated bonds, an aqueous solution of an unsaturated compound is used, and the viscosity is preferably about 5 to 1000 cps at room temperature. Further, a surfactant may be mixed in order to improve the dispersibility of the unsaturated compound. Moreover, in order to perform an impregnation process more efficiently, it is preferable to heat (50-150 degreeC) the aqueous solution of an unsaturated compound and to immerse for 5 to 200 minutes.

  The step of impregnating the compound having at least two unsaturated bonds is preferably recommended under high pressure conditions (atmospheric pressure to 10 atm). Since the unsaturated fiber is impregnated into the polyester fiber under pressure, the unsaturated compound is injected into the inside of the fiber, and a large amount of the unsaturated compound can be injected into the polyester fiber.

  The irradiation energy of electron beam irradiation is preferably 10 to 5000 kGy to introduce a crosslinked structure into the polyester fiber. In the case of 10 kGy or less, since the crosslinking reaction does not proceed sufficiently, the polyester fiber cannot be modified. Moreover, even if it exceeds 5000 kGy, the formed cross-linked reaction layer becomes brittle, the polyester is further decomposed, and the performance as the inherent polyester fiber yarn is not obtained, which is not preferable. The treatment is preferably performed at 20 to 1000 kGy.

  Furthermore, it is recommended that the polyester fiber subjected to the electron beam irradiation treatment is heated to a temperature higher than the glass transition point. That is, the polyester fiber of the present invention is preferably heated to 70 ° C. or higher. In a fiber impregnated with a compound having two or more unsaturated compounds, it can be considered that the compound is injected into the amorphous region of the fiber. After irradiation with an electron beam, a radical is generated, and then heated to the glass transition point. By doing so, the reactivity in an amorphous region becomes high and formation of a crosslinking reaction can be promoted.

  In addition, it is recommended that the impregnated polyester fiber be subjected to an electron beam irradiation treatment in an atmosphere having an oxygen concentration of 500 ppm or less in the step of introducing a crosslinked structure into the polyester fiber. When the oxygen concentration exceeds 500 ppm, radicals generated by electron beam irradiation disappear in a short time, and the crosslinked structure is not efficiently introduced into the polyester fiber. When the oxygen concentration is 100 ppm or less, a more preferable effect is obtained. It is more preferable to carry out in a nitrogen atmosphere.

  The present invention relates to the modification of polyester yarn for carpets, and in particular, improves the disadvantage that polyester yarn is said to be easily sag. When the carpet pile is bent or compressed, a greater force is applied to the surface portion of the fiber than inside the fiber. The unsaturated compound is injected into the inside of the fiber, but since it is injected from the fiber surface, the concentration of the unsaturated compound increases as it approaches the surface, and the concentration of the unsaturated compound when irradiated with an electron beam. As a result, many cross-linked structures are formed in the vicinity of the high fiber surface. As a result, when the carpet pile is bent or compressed, the vicinity of the fiber surface where the most force is applied is mainly modified. It is thought that improvement of the sagability is achieved.

  Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples. In addition, the implementation method of each process, the test method, and evaluation were performed as follows.

(Polyester yarn)
An original polyester multifilament yarn of 640 dtex 144f was prepared while being wound around a bobbin.

(Electron beam irradiation)
Using an electron beam irradiation apparatus manufactured by I. Electron Beam Co., Ltd., an electron beam was irradiated onto the yarn wound around the bobbin with an irradiation dose of 100 kGy.

(carpet)
Using a cross-linked polyester fiber yarn produced by the method of the present invention as a pile yarn, using a 1/10 gauge loop tuft machine, the pile length is 4.5 mm, the stitch is 46/10 cm, and the base fabric is a polyester spunbond nonwoven fabric (100 g per unit area) / M ² ) was used to prepare a loop carpet skin material, and then a tile carpet backing process was performed to produce a tile carpet, and a sag test was performed.

(Sag test and evaluation)
About each obtained tile carpet, it carries out according to JIS L1201-7 "Fiber floor covering physical-property test method-thickness reduction test method by dynamic load", and the pile sag is visually checked with an untested one. Comparison was made and evaluated according to the following criteria.
Evaluation criteria ◎ No change in appearance
○ Appearance changes, but no sag
△ Change in appearance due to dripping
X A value of Δ or more where a remarkable change due to sag was seen in the appearance was regarded as acceptable.

<Example 1>
Triaryl isocyanurate was dispersed in water by adding 5% triallyl isocyanurate and 2.5% nonionic surfactant Emanon 1112 (manufactured by Kao Corporation) to ion-exchanged water and mixing well. Next, the triallyl isocyanurate dispersion and the original polyester multi-filament yarn wound around a bobbin were put into a cheese dyeing machine and pressurized to 2 atm at 120 ° C. for 60 minutes to perform an impregnation process (impregnation step) ). Then, after washing and drying, the yarn wound on the bobbin with an irradiation dose of 100 kGy is irradiated with an electron beam at an oxygen concentration of 100 ppm (electron beam irradiation process), and immediately heated at 100 ° C. for 5 minutes. (Step of heating above the glass transition point) to produce a crosslinked polyester fiber yarn. Using the obtained cross-linked polyester fiber yarn, a loop carpet skin was prepared, and then a tile carpet was prepared through a tile carpet backing process, and a sag test was performed. The pile sag was evaluated as ◎ because no change was observed in the appearance when visually compared with an untested one.

<Examples 2 to 6>
Although it implemented and evaluated by the content described in Table 1, all got favorable evaluation.

<Comparative Examples 1-3 Reference Example>
Comparative Examples 1 to 3 were carried out with the contents described in Table 1 and evaluated. In Comparative Example 1, the unsaturated compound was omitted, in Comparative Example 2, the irradiation dose was small, and in Comparative Example 3, the irradiation dose was set high, and each process was performed. In Comparative Examples 1 and 2, the sagability was not improved, and in Comparative Example 3, the polyester was decomposed and became brittle. Further, as a reference example, a carpet using nylon yarn having the same fineness was given and evaluated, but no significant difference was found from the examples.

  The polyester fiber according to the present invention is not limited to carpets, and can be used for fabrics having a pile form. Thus, an unprecedented polyester fabric with less sag can be obtained, and its application range is wide.

Claims (6)

  A step of impregnating a polyester fiber with a compound having at least two unsaturated bonds, and a step of introducing a crosslinked structure into the polyester fiber by subjecting the impregnated polyester fiber to an electron beam irradiation treatment, A method for producing a crosslinked polyester fiber.   2. The crosslinking according to claim 1, wherein in the step of impregnating the compound having at least two unsaturated bonds, the compound having at least two unsaturated bonds is impregnated in a state of being dispersed in water. For producing a molded polyester fiber.   The method for producing a crosslinked polyester fiber according to claim 1 or 2, wherein the step of impregnating the compound having at least two unsaturated bonds is performed under high-pressure conditions.   The electron beam irradiation treatment is performed in an atmosphere having an oxygen concentration of 500 ppm or less in the step of introducing a crosslinked structure into the polyester fiber by performing an electron beam irradiation treatment on the impregnated polyester fiber. The method for producing a crosslinked polyester fiber according to any one of the items.   A step of impregnating the polyester fiber with a compound having at least two unsaturated bonds, a step of applying an electron beam irradiation treatment to the impregnated polyester fiber to introduce a crosslinked structure into the polyester fiber, and the electron beam irradiation A method for producing a crosslinked polyester fiber, comprising a step of heating the treated polyester fiber to a glass transition point or higher.   A cross-linked polyester fiber for carpet produced by the method for producing a cross-linked polyester fiber according to claim 1 and a carpet thereof.