JPS60197723A - Composite material - Google Patents

Abstract

PURPOSE:A composite material which has high vibration-damping property and can be used at higher temperature, comprising a reinforcing fiber and an epoxy resin containing modified polyethylene glycol. CONSTITUTION:A composite material comprising a reinforcing fiber (e.g., carbon fiber or glass fiber) and an epoxy resin (e.g., bisphenol A-derived epoxy resin) containing 10-40wt% amino group- or carboxyl group-terminated polyethylene glycol (hereinafter, abbreviated as modified PEG). This composite material can retain high vibration-damping property at high temperatures without exudation of the modified PEG because an epoxy resin containing polyethylene glycol having the modified PEG is used as the matrix resin. Besides, its strength and modulus are not less than those of a conventional composite material. Therefore, this composite material can be used effectively in the production of car stereo loud- speaker boxes, handles of electric drills, handles of chain saws, etc., for parts of an artificial satellite or as a structural material for automobiles, ships, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a composite material, and more particularly to a composite material of reinforcing fibers and resin.

(b) Conventional technology and its drawbacks Composite materials of reinforcing fibers and resins have been developed in recent years for sports applications such as golf shafts and tennis rackets, for acoustic applications such as speaker cones and speaker boxes, and for back decks and soundboards of guitars and violins. It is used in an extremely wide range of fields, such as musical instruments. However, in such applications, without exception, high vibration damping properties are required.

As such a high vibration damping composite material, for example, the one described in Japanese Patent Application Laid-Open No. 113299/1984 is known. In this conventional composite material, polyethylene glycol, which itself has high vibration damping properties, is mixed into the so-called matrix resin, thereby improving the vibration damping properties of the composite material. However, although such conventional composite materials do not have much of a problem at temperatures around room temperature, they have the disadvantage that polyethylene glycol flows out at high temperatures, in other words, the vibration damping properties decrease, and at most temperatures up to about 40'C. It can only be used in the area.

(c) Purpose of the Invention The purpose of the present invention is to provide a composite material which solves the above-mentioned drawbacks of conventional composite materials, has high vibration damping properties, and can be used even at higher temperatures.

(d) Structure of the Invention In order to achieve the above object, the present invention provides a composite material consisting of reinforcing fibers and a resin, and the resin contains polyethylene glycol having an amino group or a carboxyl group as a terminal group. A composite material is provided, characterized in that it is made of a poxy resin containing 10 to 40%.

To explain this invention in more detail, the composite material of this invention is made by combining reinforcing fibers and resin.

The above-mentioned reinforcing fibers include high-strength and thin fibers such as carbon fibers, glass fibers, and organic high-elastic fibers (e.g., polyaramid fibers), which are commonly used as reinforcing fibers for miscellaneous reinforced plastics.
Highly elastic fiber. Among them, carbon fiber is most preferably used. However, two or more different types of these reinforcing fibers may be used in combination.

Further, the resin is composed of an epoxy resin and polyethylene glycol (hereinafter referred to as modified PEG) having an amino group or a carboxyl group as a terminal group. The epoxy resin may be of any type, such as bisphenol A type, aliphatic type, or phenol novolac type. In addition, modified PEG
gives high vibration damping properties to the composite material, and those having high compatibility with epoxy resins and having a molecular weight of about -400 to 10,000 are preferably used. More preferably, those having a molecular weight of -400 to -6000 are used.

A typical example of such modified PEG is PEG 40 manufactured by Sanyo Chemical Industries, Ltd., which has an amino group.
00D CA'' has a carboxyl group, such as 'Ionet YB-400'' manufactured by the same company.

The amount of modified PEG mixed into the epoxy resin is 10 to 40
Weight%. That is, if it is less than 10% by weight, a composite material with high vibration damping properties cannot be obtained. Moreover, if it exceeds 40% by weight, the rigidity of the composite material will be significantly reduced, making it unusable. A more preferable amount is 10 to 25%.

The composite material of the present invention is produced by combining the reinforcement 111H with an epoxy resin mixed with a desired modified PEG, and then heating the composite to 100 to 120'C to bond the modified PEG with the epoxy resin. , manufactured by curing epoxy resin according to conventional methods. The curing temperature of the epoxy resin is 130 to 180°C. However, in the present invention, the modified PEG may be combined with the epoxy resin and then composited with reinforcing fibers.

(e) Effects of the present invention The composite material of the present invention contains modified PEG, that is, polyethylene glycol having an amino group or a carboxyl group as a terminal group, in a concentration of 10 to 40% as a so-called matrix resin.
Since the epoxy resin containing % by weight is used, the modified PEG does not flow out even when used at high temperatures, and high vibration damping properties can be maintained. Moreover, its strength and elastic modulus are comparable to those of conventional composite materials. Therefore, the composite material of this invention can reach high temperatures during use.
Furthermore, it is particularly suitable for applications requiring high vibration damping properties. For example, if it is used as a component of a car stereo speaker box, you can enjoy clear sound without resonance even in the hot car interior under the scorching sun. Furthermore, when used on the handles of chainsaws and electric drills, for example, vibrations are suppressed even when the motors heat up to high temperatures, helping to prevent occupational diseases caused by vibrations. Furthermore, when used in parts of artificial satellites, vibrations are suppressed even when frictional heat is applied, allowing for accurate attitude control. Furthermore, it can also be used as a structural material for automobiles, ships, etc. Of course, there is no problem in using it for sports or musical instruments as described above.

Example 1 100q of epoxy resin “Epicote” 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) and 20g of modified PEG”
PEG4000DCA” (manufactured by Sanyo Chemical Industries, Ltd.)
was added and heated at about 120°C for about 2 hours to bond the modified PEG with the epoxy resin, then the temperature was lowered to about 70°C, and 3o dicyandiamide/N-3,4 dichlorophenylene N=-dimedylurea was added as a curing agent. A matrix resin was obtained.

Next, we will introduce the carbon fiber trading card “T-300” manufactured by Toshi Co., Ltd.
After impregnating the above matrix resin into a sheet made of 3,000 strands arranged in parallel to each other in one direction, the carbon fibers were cut into 5 squares of 300 m with the directions aligned.

Next, place the cut pieces into the mold 3 times with the direction of the carbon fibers aligned.
Laminate the sheets, apply a pressure of about 10 Ko/cm2, and
Heat at 40°C for about 2 hours to harden the matrix resin.
The volume content of carbon fiber is approximately 60%, and the thickness is 2
11111 was obtained.

Regarding composite materials, tensile modulus and 20℃, 44
When we measured the vibration damping coefficient at 0Hz and the outflow amount of modified PEG, the tensile modulus was approximately 13°000KO/+
na2, the vibration damping coefficient was about 0°45×10-2, and the amount of modified PEG flowing out was almost zero. Note that the vibration damping coefficient was measured by the vibration lead method. In addition, the amount of outflow of modified PEG is calculated by immersing the composite material in boiling water for about 20 hours, and calculating the weight W before immersion and the weight 1 W after immersion.
Therefore, it was determined by the formula (W-W)Xl 00/W. In other words, the amount of modified PEG flowing out corresponds to the case where the composite material is used at about 100°C.

Example 2 A composite material of the present invention was produced in exactly the same manner as in Example 1, except that 20 grams of modified PEG (molecular weight: about 400) having a carboxyl group as a terminal group was mixed into 1 ooq of the epoxy resin used in Example 1 above. Obtained.

Next, for each of the above composite materials, the tensile modulus, vibration damping coefficient, and outflow amount of modified PEG were measured in the same manner as in Example 1, and the tensile modulus was approximately 13,000 K Q /'m.
i2, the vibration damping coefficient was approximately 0.40X10-2, and the amount of modified PEG flowing out was almost zero.

Comparative Example Instead of modified PEG, polyethylene glycol ``PEG4000'' manufactured by Sanyo Chemical Industries, Ltd. (molecular weight: approximately 4
000) was used in exactly the same manner as in Example 1,
A composite material was obtained.

When this composite material was subjected to the same test as in Example 1, the tensile modulus was approximately 13.100Kq/■2, and the vibration damping coefficient was approximately 0.46X1Q-2, which was the same as in Example 1.2.
It wasn't that different from that. However, the amount of polyethylene glycol flowing out was about 5% by weight. This indicates that when this composite material is used at high temperatures, polyethylene glycol flows out, and the vibration damping properties decrease accordingly.

Patent applicant: Toshi Co., Ltd.

Claims (1)

[Claims] 1. A composite material comprising reinforcing fibers and a resin, wherein the resin is an epoxy resin containing 10 to 40% by weight of polyethylene glycol having an amino group or a carboxyl group as a terminal group.