JP2010275656A - Wholly aromatic polyamide fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wholly aromatic polyamide fiber that is excellent in opening properties during molding, causes less single yarn breakage and has excellent adhesion to a matrix resin. <P>SOLUTION: The wholly aromatic polyamide fiber has an oiling agent containing a polyalkylene glycol component and a higher fatty acid ester compound of a monobasic higher alcohol in a weight ratio of 70/30 to 95/5 and adhering to the surface of the wholly aromatic polyamide fiber. It is more preferably that the terminal of the polyalkylene glycol component is blocked with a higher fatty acid. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wholly aromatic polyamide fiber which is excellent in process stability as well as a resin reinforcing effect and particularly suitable for a thermosetting resin.

  Fully aromatic polyamide fibers, so-called aramid fibers, are representative of high-performance fibers, taking advantage of their heat resistance, high strength, high modulus, chemical resistance, etc., and lightweight, high strength, high rigidity as reinforcing fibers for matrix resins. Has been put to practical use in the required fields.

  And for example, as a raw material for sports and leisure equipment such as rackets, golf clubs and bags, car interior and exterior parts, aircraft members, thermosetting resin is applied to a sheet-like material in which multiple fibers are aligned in one direction. A prepreg sheet of wholly aromatic polyamide fibers impregnated is used. As a material that enables further impact resistance and lighter weight than carbon fibers and glass fibers used in similar applications, it has attracted attention as a composite and auxiliary material.

  In general, however, aramid fibers exhibit an excellent force in the fiber axis direction, but in the direction perpendicular to the fiber, there is a problem that the orientation and crystallinity in the fiber axis direction are too high and fibrillation is likely to occur. Compared to carbon fiber and glass fiber, wholly aromatic polyamide fiber has low elastic modulus and rigidity, so it can be used as a guide under high tension to obtain spreadability and sheet uniformity during molding. Contact is required. That is, originally, a fully aromatic polyamide fiber which is easily fibrillated by rubbing is required to be processed under conditions where further fluff is generated and the uniformity of the sheet is lowered. When such a flaw is caused, there is a problem that the reinforcing effect is naturally lowered.

  As matrix resins for composite materials, epoxy, unsaturated polyester, and epoxy acrylate are mainly used, but adhesion between fibers and matrix resin is also one of the major problems. This is because the aromatic amine composing the aramid fiber is much less basic than the aliphatic amine due to the phenyl group adjacent to the amine group, so it has affinity and reactivity with the thermosetting matrix resin with polarity and reactivity. Is low.

  In order to solve these problems, for example, in Patent Document 1, as a method for improving adhesiveness, propylene oxide having a specific molecular weight and copolymerization ratio on the surface of a wholly aromatic polyamide fiber in which a solid cation-exchangeable inorganic compound is fixed on the fiber surface. It has been proposed to provide a copolymer of ethylene oxide. However, the oil film strength was low, single yarn breakage occurred due to rubbing of a guide or the like during molding, the uniformity of the product was poor, and the adhesiveness was not satisfactory.

Further, Patent Document 2 proposes an untwisted high-performance fiber having an inorganic powder applied to the fiber surface and having a low entanglement number. The purpose is to improve the spreadability and reduce the tension applied to the fiber during molding. However, for the generation of fuzz and the improvement of adhesion, the effect was not fully satisfactory.
Development of wholly aromatic polyamide fibers suitable for thermosetting resin reinforcement with good moldability and adhesiveness has been desired.

JP-A-2-84574 Japanese Patent Laid-Open No. 2007-23452

  An object of the present invention is to provide a wholly aromatic polyamide fiber which is excellent in openability at the time of molding, has few single yarn breaks, and has excellent adhesion to a matrix resin.

In the wholly aromatic polyamide fiber of the present invention, an oil containing a polyalkylene glycol component and a higher fatty acid ester compound of a monobasic higher alcohol in a weight ratio of 70/30 to 95/5 is attached to the surface of the wholly aromatic polyamide fiber. It is characterized by that. Furthermore, it is preferable that the end of the polyalkylene glycol component is blocked with a higher fatty acid.
The fiber resin composite of the present invention is obtained by reinforcing a matrix resin with the wholly aromatic polyamide fiber of the present invention.

  According to the present invention, there is provided a wholly aromatic polyamide fiber that is excellent in fiber opening at the time of molding, has few single yarn breaks, and has excellent adhesion to a matrix resin.

It is the schematic of the installation for evaluating the opening property of the wholly aromatic polyamide fiber of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
The wholly aromatic polyamide fiber referred to in the present invention is a para-aromatic polyamide fiber, a meta-polyamide fiber, or a copolymer thereof. Examples of aromatic rings include 1,4-phenylene group, 1,3-phenylene group, 4,4′-bisphenylene group, 1,5-naphthylene group, 2,6-naphthylene group, 2,5-pyridylene group and the like. Among them, 1,4-phenylene group is preferable. The aromatic ring may contain, for example, a halogen group (for example, chlorine, bromine, fluorine), a lower alkyl group (methyl group, ethyl group, isoppropyl group, n-propyl group), cyano group, acetyl group, nitro group and the like. . Specific examples include polyparaphenylene terephthalamide (“Twaron” manufactured by Teijin Techno Products Co., Ltd., “Kevlar” manufactured by Toray DuPont Co., Ltd.), polymetaphenylene isophthalamide (“Conex” manufactured by Teijin Techno Products Co., Ltd.), It is a fiber made of polyparaaminobenzamide, poly-3,4'oxydiphenylene terephthalamide / polyparaphenylene terephthalamide copolymer (such as “Technora” manufactured by Teijin Techno Products Limited), polyparaaminobenzhydraterephthalamide, etc. .

  The single yarn fineness of the wholly aromatic polyamide fiber of the present invention is preferably 0.1 to 4 dtex, and more preferably 0.5 to 2 dtex for achieving the object of the present invention. When the single yarn fineness is less than 0.1 dtex, there is a problem in the yarn forming property, or the single yarn breakage tends to occur during molding. On the other hand, if it exceeds 4 dtex, the effective bonding area with the matrix resin becomes small and the reinforcing effect tends to be lowered.

  In the wholly aromatic polyamide fiber of the present invention, an oil containing a polyalkylene glycol component (component A) and a higher fatty acid ester compound of monobasic higher alcohol (component B) is attached to the surface.

  The polyalkylene glycol (component A) used in the oil agent of the present invention is obtained by polymerizing or copolymerizing alkylene oxides such as ethylene oxide and propylene oxide. The average molecular weight is preferably 2000 or less, more preferably 700 to 1000. It is particularly preferable that the copolymerization ratio of ethylene oxide is high.

  Also, one or both ends of these polyalkylene glycols are preferably blocked with an ester bond in the present invention. In particular, it is preferable that one end is blocked because the molecular weight is small and fluff generation can be effectively prevented, and both compatibility and adhesiveness are compatible. At this time, it is preferable that a higher fatty acid is used for blocking the polyalkylene glycol component. In particular, the same component as the higher fatty acid ester compound (component B) of a monobasic higher alcohol described later is preferable from the viewpoint of compatibility.

  In the present invention, a higher fatty acid ester compound (B component) of a monobasic higher alcohol is used as a component of the oil together with the polyalkylene glycol component (A component). The higher fatty acid ester compound (component B) is obtained from a monobasic higher alcohol having 8 to 20 carbon atoms and a fatty acid having 10 to 20 carbon atoms, and preferably has a molecular weight of 500 to 1000. When the molecular weight is 500 or less, the heat resistance tends to be poor. When the molecular weight is 1000 or more, the smoothing performance tends to be lowered, and the effect of suppressing single yarn breakage during molding is reduced.

  In the wholly aromatic polyamide fiber of the present invention, an oil agent containing the above-mentioned A component / B component in a weight ratio of 70/30 to 95/5 adheres to the fiber surface. When the ratio of the component A is 70 or less, the affinity with the matrix resin is poor, the adhesiveness is lowered, and the reinforcing effect is lowered. On the other hand, when the weight ratio of the B component is 5 or less, the smoothing performance is poor, and the effect of suppressing single yarn breakage during molding cannot be obtained.

  The amount of the oil agent attached to the fiber is preferably 0.5 to 3.0% by weight applied to the wholly aromatic polyamide fiber. When the adhesion amount is small, the smoothness performance is lowered, and it is difficult to obtain the effect of suppressing single yarn breakage during molding. On the other hand, when such an oil agent adhesion amount is large, the adhesion with the matrix resin is hindered and the reinforcing effect intended by the present invention tends to be reduced.

  Such a wholly aromatic polyamide fiber of the present invention is widely used as a reinforcing fiber for composite materials, and is particularly preferably used for a fiber resin composite in which the matrix resin is a thermosetting resin. When such a resin is used, the generation of fluff inevitably increases, and therefore, the fibers of the present invention that have extremely low fluff generation and high adhesion are preferably used. The fiber resin composite in which the matrix resin is reinforced with the wholly aromatic polyamide fiber of the present invention has very few defects due to fluff in the fiber inside the composite used for reinforcement, and in order to maintain high adhesion between the resin and the fiber, This is a composite material having high physical properties.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the measured value in an Example was measured with the following method.

(1) Fineness It measured based on JIS-L1013.

(2) Oil agent compatibility Each component was mixed at normal temperature and the compatibility was visually determined. Without separation of each component, a uniform case was judged as good (◯), and a case where it was separated was judged as poor (×).

(3) Opening property As shown in FIG. Multifilament sprinkled on Is pulled out at a speed of 3 m / min, passed through the fixed bar guides (2a to 2f) arranged on the top and bottom, and adjusted so that the tension between the two bar guides 2e and 2f is 1.0 g / dtex. And wound up. The fiber width of the multifilament when passing the upper side of the bar guide 2e was measured to determine the spreadability.

(4) Product quality The multifilament was wound up for 10 minutes under the same conditions as for evaluating the spreadability, the surface of the wound sample was visually observed, and the product quality was judged from the presence or absence of fluff. The case where fluff was not generated was evaluated as good (◯), and the case where fluff was generated was determined as impossible (×).

(5) Adhesiveness (interlaminar shear strength: abbreviated as ILSS)
As an epoxy resin, Epicoat 828 (manufactured by Shell Chemical Co., Ltd.) was mixed at a ratio of 67% by weight, Epomate B001W (manufactured by Shell Chemical Co., Ltd.) at 27% by weight, and Denacol EX-191 (manufactured by Nagase ChemteX) at a ratio of 6% by weight. A thing was used. Fibers were immersed in the epoxy resin mixture, and a curing treatment was performed with the fibers aligned in one direction. The curing condition was that after standing at room temperature for 48 hours, pressurizing at 120 ° C. for 2 hours to cure, and then performing a post-curing treatment at 180 ° C. for 1 hour. A test piece having a length of 20 mm, a width of 6 mm, and a thickness of 3 mm was prepared from the molded product thus obtained (fiber content: 60%), and a span interval of 13 mm and a crosshead speed of 1. Interlaminar shear strength (ILSS: unit kg / mm ² ) was measured at 0 mm / min.

[Examples 1 to 5]
A fully aromatic polyamide fiber having a single yarn fineness described in Table 1 was spun, and a thread-forming oil was applied to the surface so as to have an adhesion amount shown in Table 1, dried, and finally wound up. As a polyalkylene glycol component, the yarn-making oil has a propylene oxide / ethylene oxide copolymer ratio of 30/70, a molecular weight of 780 (component A) blocked at one end with lauric acid, and a higher fatty acid ester compound of a monobasic higher alcohol. As component (B component), and the ratio of A component / B component is 90/10.
The fiber resin composite which consists of an epoxy resin and a wholly aromatic polyamide fiber was created according to the evaluation method of (5) adhesiveness using the fiber finally obtained. Details of each fiber and various evaluation results are also shown in Table 1.

[Comparative Example 1]
The same procedure as in Example 1 was carried out except that the oil making agent had only a propylene oxide / ethylene oxide copolymerization ratio of 30/70 and a molecular weight of 780 (component A) blocked at one end with lauric acid.

[Comparative Example 2]
In Example 1, the same procedure was carried out except that the yarn-making oil was only isooctyl laurate (component B).

  Such a wholly aromatic polyamide fiber of the present invention has very little fluff generation and high adhesiveness, and is therefore used for a composite material having high physical properties. In particular, it is suitably used as a prepreg sheet impregnated with a thermosetting resin, and is optimal as a raw material for sports and leisure equipment such as rackets, golf clubs and bags, interior and exterior parts of vehicles, and aircraft members.

1: Evaluation samples 2a to 2f: Bar guide 3: Winding bobbin 4: Traveling yarn

Claims (3)

  A total fragrance characterized in that an oil containing a polyalkylene glycol component and a higher fatty acid ester compound of a monobasic higher alcohol in a weight ratio of 70/30 to 95/5 is attached to the surface of a wholly aromatic polyamide fiber. Group polyamide fiber.   The wholly aromatic polyamide fiber according to claim 1, wherein the end of the polyalkylene glycol component is blocked with a higher fatty acid.   A fiber resin composite in which a matrix resin is reinforced with the wholly aromatic polyamide fiber according to claim 1.

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