JPH01174413A - Composite yarn prepreg - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a composite yarn prepreg in which fiber threads are impregnated with a thermosetting resin and treated to a semi-cured state, and is used in filament winding during the production of reinforced plastic products. It is used to form pipes, vessels, tanks, etc. by the method.

(Prior art) When manufacturing reinforced plastic molded products in the shape of pipes, vessels, tanks, etc., the filament winding molding method is generally used. It was impregnated and then wound around a mandrel. However, in recent years, there has been a need for high-mix, low-volume production, as well as a desire to improve the work environment for filament winding, so prepreg yarn that has been pre-impregnated with a thermosetting resin and semi-cured is wound around a bobbin. This package is then sent to a molding factory.

However, when using a yarn bundle containing filaments of inorganic fibers such as carbon fibers, glass fibers, and boron fibers as the above-mentioned fiber yarns and making this into prepreg, it is necessary to maximize the strength of the constituent fibers containing the above-mentioned inorganic fiber filaments. For limited use, the constituent fibers were arranged in a substantially untwisted state.

(Problems to be Solved by the Invention) When a yarn bundle containing inorganic fiber filaments is made into a prepreg, the above-mentioned inorganic fiber filaments come into contact with yarn guides, guide bars, rollers, etc. and undergo ironing, but the inorganic fiber filaments Since the filaments are bundled in a substantially untwisted state, they are easily damaged.In addition, in order to make the prepreg yarn easier to handle, it is necessary to give flexibility to the prepreg yarn. At the same time, tackiness is imparted, and the winding pressure when wound onto a bobbin causes some adhesion between the prepreg yarns, so when the prepreg yarns are unraveled from the bobbin during molding, There was a problem in that fiber cracking and yarn cracking were likely to occur. Moreover, since inorganic fibers are brittle, there is a problem in that they are easily broken due to the above-mentioned fiber cracking.

This invention solves the above-mentioned drawbacks of a yarn bundle containing at least inorganic fibers in its constituent fibers, and prevents the inorganic fiber filaments from being damaged by the ironing action when forming the yarn bundle into prepreg. Unraveling from the package is done smoothly and there is no occurrence of fiber or thread breakage.
Therefore, the present invention provides a prepreg in which the inorganic fiber filaments are not damaged.

(Means for Solving the Problems) The prepreg of the present invention comprises a yarn bundle in which the fiber yarns for impregnation with a thermosetting resin include at least inorganic fiber filaments in a substantially untwisted aligned state. It is characterized by being a composite yarn in which the yarn is covered by winding a sheath yarn, and the above thermosetting resin is treated to a semi-hardened state as in the past, and remains solid at room temperature. Although it is non-sticky and has flexibility, it is in an uncured resin state that melts when heated to the molding temperature.

The above-mentioned inorganic fiber filaments include filaments of carbon fiber, glass fiber, boron fiber, etc., and one type thereof may be used alone.

Further, two or more types may be used in combination, and these inorganic fiber filaments are arranged in a substantially untwisted state, and the inorganic fiber filaments maintain a parallel state without entanglement. In addition, based on this inorganic fiber filament, 7 lamid fibers, fully aromatic polyester fibers, ultra-high molecular weight polyethylene fibers, and ultra-high molecular weight polyvinyl alcohol fibers have a tensile strength of 15 g/d or more and a tensile modulus of 5.
High strength and high elastic modulus organic fiber filaments of 00 g/d or more may be added in an aligned manner.

The sheath yarn that covers the core yarn, which is composed of the above-mentioned yarn bundle of inorganic fiber filaments or aligned yarn bundle of inorganic fiber filaments and high-strength/high-modulus organic fiber filaments, is a bundle of non-twisted core yarns. Any fiber can be used as long as it can be maintained at
In addition to filament yarns of synthetic fibers such as polyester, spun yarns, or ordinary organic fiber yarns having fluff or loops, the above-mentioned high-strength and high-modulus organic fiber yarns can be used.

In addition, thermosetting resin (Strix resin) is heated at 140°C.
Any thermosetting resin for prepreg that can be cured in the following manner may be used, and examples thereof include epoxy resin, unsaturated polyester resin, and vinyl ester resin.

(Function) Since the yarn bundles containing inorganic fiber filaments are aligned in parallel, the strength of the filaments is maximized, and the core yarn, which is mainly composed of the filaments, is covered with the sheath yarn. Therefore, the above-mentioned filament is prevented from coming apart, and the above-mentioned inorganic fiber filament comes into direct contact with the guide etc. and is squeezed in the blibreg process in which the composite yarn consisting of the above-mentioned core thread and sheath thread is impregnated with thermosetting resin. This prevents fiber cracking and yarn breakage from occurring when the composite yarn prepreg is unraveled during molding after winding the obtained composite yarn prepreg onto a bobbin, and damage to the inorganic fiber filaments is prevented. Ru. This composite yarn prepreg is then wound around a mandrel in a conventional manner to form it into a desired shape, and then heated to melt the thermosetting resin and then harden, creating a plastic reinforced with inorganic fiber filaments. A molded product is obtained.

When a composite yarn bundle in which the above-mentioned inorganic fiber filament is added with the above-mentioned high-strength/high-modulus organic fiber filament is used as a core thread and covered with a sheath thread, a plastic molded article with excellent impact resistance can be obtained. However, if the tensile strength of high-strength, high-modulus organic fiber filaments is less than 15 g/d or the tensile modulus is less than 500 g/d, it will be weaker than inorganic fiber filaments, which mainly have tensile strength characteristics. As a result, the strength properties of the resulting plastic molded product no longer meet the objectives. In addition, the amount of high strength/high elastic modulus organic fiber filament added is preferably less than 50% of the total amount of core yarn, and if it is more than this,
Compared to the case where a yarn bundle consisting only of inorganic fiber filaments is used as the core yarn, the compression characteristics and bending characteristics of the plastic molded product are significantly lowered.

The coverage rate of the above composite yarn in which the core yarn is covered with a sheath yarn (the ratio of the length of the part where the sheath yarn covers the core yarn to the core yarn length, The product of the width (b) and the number of turns per meter of core yarn is 0.1 to 10%, especially 0.5 to 5
% is preferable; if it is less than 0.1%, it will be difficult to maintain the cohesiveness of the core yarn, and the covering effect with the sheath yarn will not be obtained;
If it exceeds %, the tensile strength characteristics will decrease compared to the thickness of the covering yarn, and the penetration of the matrix resin (thermosetting resin) will be inhibited. Considering the above coverage, the fineness of the sheath yarn is preferably 5 to 30 deniers.

(Example) Carbon fiber filament yarn (manufactured by Toho Rayon Co., Ltd., Besphite HTA-7W-1000, 600 denier, 10
00 filament) and high-strength, high-modulus fiber filament yarn (Dyneema ultra-high molecular weight polyethylene fiber,
Dyneema 5K-60゜300 denier) were pulled together without twisting, and the core yarn and silicon nylon °6 (12 denier, 5 filament) were used as sheath yarns around the core yarn.
Covering was performed with a number of turns of 0/-. The coverage rate of this composite yarn was 4.3%.

20 parts of bisphenol A-based epoxy resin (liquid) and bisphenol A-based epoxy resin (
An epoxy resin consisting of 80 parts of dianediamide (hardening agent), 5 parts of aromatic urea (hardening accelerator), and 100 parts of a 50150 mixture of methyl ethyl ketone and methanol was impregnated by immersion, and then heated to 100°C. 1 in hot air
It was dried for 0 minutes and wound onto a bobbin to obtain a composite yarn prepreg of an example. During this bripreg process, no damage to the carbon fiber filaments due to the straining action of the yarn guide, guide bar, rollers, etc. was observed. Moreover, since it was made into a prepreg and was in a semi-cured state, it had some tackiness, but it had flexibility and there was no problem in winding it up. In addition, when the obtained composite yarn prepreg was wound onto a bobbin and unwound at a speed of 10 m/min to examine its unraveling properties, unraveling was performed smoothly and there was no breakage of the carbon fiber filaments. However, only a slight amount of sticking was observed between the thread-cut tiles.

On the other hand, in the prepreg of Comparative Example 1, which was manufactured in the same manner as in the example except that the covering of the above example was omitted, the carbon fiber filaments were cut during the pre-preg process, especially by ironing with a roller in a resin bath. occurs in large numbers,
In the process after the resin bath, damage to the filament was accelerated by the straining of the bar and guide, making continuous winding impossible.

A prepreg of Comparative Example 2 was produced in the same manner as Comparative Example 1 above, except that a resin liquid was applied by a roller coating method instead of the resin bath of Comparative Example 1 above. In this case, damage to the carbon fiber filaments due to ironing was only slightly reduced compared to Comparative Example 1. In addition, when the prepreg package of the comparative example was rewound at a speed of 10 m/min,
Carbon fiber filaments have higher adhesive properties than ultra-high molecular weight polyethylene fiber filaments, resulting in yarn cracking.
The point at which the carbon fiber filament leaves the package surface fluctuates, eventually causing the carbon fiber filament to break and unraveling to become impossible.

Comparative Example 2 except that an aramid fiber filament (manufactured by DuPont, Kevlar 49,380 denier) was used in place of the ultra-high molecular weight polyethylene fiber filament of Comparative Example 2.
A prepreg of Comparative Example 3 was produced in the same manner as above. In this case, damage to the carbon fiber filament occurred almost similarly to Comparative Example 2, making it impossible to rewind the package.

A prepreg of Comparative Example 4 was produced in the same manner as Comparative Example 2 except that the ultra-high molecular weight polyethylene fiber filament of Comparative Example 2 was omitted, and when the prepreg package was rewound at a speed of 10 m/min, Comparative Example 2 Similar to .3, yarn breakage occurred frequently, and the carbon fiber prepreg wound around the mandrel was of low quality with many fiber breaks.

(Effects of the Invention) In the composite yarn prepreg of the present invention, since the core yarn containing at least carbon fiber filaments is covered with the sheath yarn, damage to the inorganic fiber filaments during the resin impregnation process is prevented, and the passability of the prepreg process is improved. Excellent and easy to manufacture. In addition, after being wound into a package on a bobbin, yarn cracking or fiber cracking does not occur when the inorganic fiber filament is wound back for molding, and therefore smooth unraveling is possible without damaging the inorganic fiber filament.

Patent applicant: Toyobo Co., Ltd. Agent: Patent Attorney Yoshi 1) Tsukasa Ryo

Claims (1)

[Scope of Claims] [1] A prepreg in which fiber threads are impregnated with a thermosetting resin and treated to a semi-cured state, wherein the fiber threads contain at least inorganic fiber filaments in a substantially untwisted aligned state. A composite yarn prepreg characterized in that it is a composite yarn in which a yarn bundle is used as a core yarn and the core yarn is wrapped around it by winding a sheath yarn. [2] The composite yarn prepreg according to claim 1, wherein the core yarn is a yarn bundle consisting of substantially untwisted aligned inorganic fiber filaments and high-strength, high-modulus organic fiber filaments. . [3] 20g of high-strength, high-modulus organic fiber filament
The composite yarn prepreg according to claim 2, which is a high-strength, high-modulus polyethylene filament having a tensile strength of at least /d and a tensile modulus of at least 500 g/d.