JPH08302572A - Carbon fiber for reinforcing highly heat-resistant resin and its resin composition - Google Patents

Abstract

PURPOSE: To obtain a resin composition, comprising a carbon fiber for reinforcing a highly heat-resistant resin having the surface coated with an aromatic polyimide and/or an aromatic polyamic acid-based resin and the highly heat- resistant resin and suitable for moldings, excellent in mechanical properties and heat and chemical resistances. CONSTITUTION: This carbon fiber for reinforcing a highly heat-resistant resin is obtained by immersing a carbon fiber in a treating liquid prepared by dissolving an aromatic polyimide resin of formulas I and II (X in both the formulas I and II is formula III or IV; Y is one or more groups selected from formulas V, VI, etc.; R1 to R7 are each a 1-20C alkyl, a halogenated alkyl, H or a halogen) and/or an aromatic polyamic acid which is its precursor in N-methyl-2- pyrrolidone and drying the resultant fiber. The surface of the resultant fiber is coated with the resin. The highly heat-resistant resin composition is obtained by blending 5-100 pts.wt. resultant carbon fiber with 100 pts.wt. highly heat- resistant resin such as a polyether ether ketone having >=250 deg.C melting point and >=100 deg.C glass transition point. The resultant resin composition is molded into a prescribed shape to a afford electronic or automotive parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon fiber suitable for reinforcing a high heat resistant resin and a high heat resistant resin composition using the carbon fiber.

[0002]

2. Description of the Related Art Polyimide, polysulfone, polyether sulfone, polyether ketone, polyether ether ketone, polyether ketone ether ketone ketone,
High heat-resistant resins such as polyphenylene sulfide, polyamide imide, and polyether imide are called super engineering plastics because they are significantly superior to general-purpose engineering plastics in terms of heat resistance and mechanical strength. It is used in applications such as machinery and automobiles. However, due to recent technological advances, properties having these high heat-resistant resins, especially those having further improved mechanical strength, have been required. Therefore, a method of improving mechanical strength and heat resistance by incorporating a fibrous reinforcing material, particularly carbon fiber, into these high heat resistant resins has been carried out. In order to improve the handling property, carbon fiber is usually used in the form of a resin coated and converged.
As the sizing agent, an epoxy resin or a polyamide resin (JP-A-53-106752) is usually used. Molding of the high heat resistant resin and the resin composition thereof requires a high temperature of 300 ° C. or higher. However, epoxy resins and polyamide resins have low thermal decomposition temperatures, so if carbon fibers that have been bundled with these resins are used for the above-mentioned high heat resistant resin, the sizing agent will thermally decompose during molding, causing the occurrence of voids and carbon fibers. The interface strength between the matrix resin and the matrix resin is reduced. Therefore, there is a problem that the original fiber reinforcing effect cannot be obtained and sufficient mechanical properties cannot be obtained.

[0003]

An object of the present invention is to provide a carbon fiber suitable for a high heat resistant resin, which does not have the above-mentioned problems. Furthermore, it is to provide a highly heat-resistant resin composition using the carbon fiber, which has excellent mechanical properties, heat resistance, and chemical resistance.

[0004]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned objects, the present inventors have found a novel carbon fiber having desired performance and a high heat resistant resin composition using the same. The present invention has been completed. That is,
The present invention includes (1) an aromatic polyimide resin of the following formula (I) [Chemical formula 2] and / or a precursor of the aromatic polyamic acid resin of the formula (II) [Chemical formula 2] Coated carbon fiber,

[0005]

Embedded image (2) The aromatic polyimide resin of the formula (I) and / or the aromatic polyamic acid resin of the formula (II) which is a precursor thereof is dissolved in an organic solvent, and the carbon fiber is immersed in the solution. (1) 5 to 100 parts by weight of the carbon fiber described in (1) above, and a melting point of 250 ° C. or higher or a glass transition temperature of 100 ° C. or higher. High heat resistant resin 100
A high heat-resistant resin composition mainly composed of parts by weight, (4) a molded product using the high heat-resistant resin composition according to (3) above.

That is, the carbon fiber of the present invention and the high heat resistant resin composition using the same are used as a sizing agent for the carbon fiber, which is the aromatic polyimide resin of the formula (I) and / or the formula (I).
I) Aromatic polyamic acid resin of I) is used, and carbon fiber containing a carbon fiber having sufficient reinforcing effect by blending with a high heat resistant resin and containing the carbon fiber, excellent mechanical properties and high heat resistance It is a resin composition. The carbon fiber of the present invention can be used by being blended with various high heat resistant resins, and exhibits a sufficient fiber reinforcing effect, and the high heat resistant resin composition containing the present carbon fiber has excellent mechanical properties and heat resistance. Therefore, it can be expected to be utilized for multipurpose as a base material for space / aircraft and a base material for electric / electronic parts, and is extremely useful. The carbon fiber of the present invention and the high heat resistant resin composition using the same use the aromatic polyimide resin of the formula (I) and / or the aromatic polyamic acid resin of the formula (II) as a sizing agent for the carbon fiber. A carbon fiber characterized by that and a high heat-resistant resin composition using the same, but other resins can also be mixed and used as a sizing agent within a range that does not impair the excellent performance of the present carbon fiber. .

Examples of resins that can be mixed and used include polyimide, polysulfone, polyether sulfone, polyether ketone, polyether ether ketone, polyether ketone ether ketone ketone, polyphenylene sulfide, polyamide imide, polyether imide, polyamide, Polyethylene, polypropylene,
Examples thereof include polystyrene, polycarbonate and polyester, and these may be used alone or in admixture of two or more.

The carbon fiber used in the present invention may be any of acrylic, pitch, rayon, lignin and the like. In the present invention, acrylic having the highest fiber strength is most preferable. Further, it is preferable that the surface of the carbon fiber is subjected to an oxidation treatment by a usual method such as ozone, plasma, nitric acid or electrolysis before being coated with the resin. The method for producing the carbon fiber of the present invention is not particularly limited, and a conventionally known method can be adopted. For example, there is a method in which the carbon fiber is immersed in a solution in which the aromatic polyimide resin of the formula (I) and / or the aromatic polyamic acid resin of the formula (II) is dissolved in an organic solvent and then dried to remove the solvent.

Examples of the solvent used include N, N
-Dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone,
1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, dimethylsulfoxide, dimethylsulfone, sulfolane, tetramethylurea, hexamethylphosphoramide, phenol, o-cresol, m-cresol, p-cresol, 2 , 3-xylenol, 2,
4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, o-chlorophenol, p-chlorophenol,
Examples thereof include o-bromophenol, p-bromophenol, o-fluorophenol, p-fluorophenol and the like. In addition, these solvents may be used alone or in combination of two or more, depending on the type of aromatic polyimide resin. The drying temperature depends on the type of solvent,
It is usually 100 to 500 ° C, preferably 150 to 450 ° C.

The carbon fiber thus obtained is coated with the aromatic polyimide resin of the formula (I) and / or the aromatic polyamic acid resin of the formula (II) in an amount of 0.05 to 20 based on the fiber.
%, Preferably 0.1 to 15% by weight, more preferably 3 to 10% by weight. If it is less than 0.05% by weight, the effect of the present invention cannot be obtained, and if it is 20% by weight.
Even if the coating is carried out over the range, it is meaningless because a larger improvement in mechanical properties cannot be expected. In the resin composition of the present invention, the amount of the carbon fiber is preferably 5 to 100 parts by weight based on 100 parts by weight of the resin. The amount is preferably 10 to 70 parts by weight, more preferably 25 to 50 parts by weight. If it is less than 5 parts by weight, the reinforcing effect peculiar to the carbon fiber, which is a feature of the present invention, cannot be obtained. On the other hand, if it is used in an amount of more than 100 parts by weight, the fluidity of the composition at the time of molding will be poor, and the moldability will be poor, making it difficult to obtain a satisfactory molded product.

The high heat resistant resin used in the resin composition of the present invention has a Tm (melting point) of 250 ° C. or higher or Tg.
It is preferable that the glass transition temperature is 100 ° C. or higher, preferably Tm 300 ° C. or higher, Tg 140 ° C. or higher, and examples thereof include aromatic polyether sulfone, aromatic polyether imide, aromatic polysulfone, aromatic polyamide imide, Examples thereof include aromatic polyimide, aromatic polyphenylene sulfide, aromatic polyether ether ketone, aromatic polyether ketone, aromatic polyether or aromatic polyester, and these may be used alone or in combination with 2
Used as a mixture of two or more species. Specifically, the aromatic polyether sulfone has a structure of the formula (III) [Chemical Formula 3] (Tg; 225 ° C., Tm; none),

[0012]

Embedded image The aromatic polyether imide has the formula (IV)
Of the structure (Tg; 215 ° C., Tm; none),

[0013]

[Chemical 4] The aromatic polysulfone has the structure of the formula (V) [Chemical formula 5] (Tg; 190 ° C., Tm; none),

[0014]

Embedded image The aromatic polyimide has a structure of the formula (VI) [Chemical Formula 6] (Tg; 170 to 260 ° C., Tm; None to 390).
℃),

[0015]

[Chemical 6] However, in the formula (VI), Y is one or more groups selected from the group consisting of the following formula [Chemical formula 7].

[0016]

[Chemical 7] And Z is a direct _{bond, -SO 2 -, - CO -} , - C (CH
₃ ) _2- or -S-. The aromatic polyphenylene sulfide has a structure of formula (VII)
g; 88 ° C, Tm; 285 ° C),

[0017]

Embedded image The aromatic polyether ether ketone has the formula (VII
I) having the structure of [Chemical Formula 9] (Tg; 143 ° C., Tm; 3
34 ° C),

[0018]

[Chemical 9] The aromatic polyether ketone is represented by the formula (IX) [Chemical Formula 1
0] structure (Tg; 154 ° C., Tm; 367)
℃),

[0019]

[Chemical 10] The aromatic polyether ketone ether ketone ketone has a structure of the formula (X) [Chemical Formula 11] (Tg; 173
℃, Tm; 380 ℃),

[0020]

[Chemical 11] The aromatic polyether has a structure of the formula (XI) [Chemical Formula 12] (Tg; 145 ° C., Tm; 340 ° C.),

[0021]

[Chemical 12] And so on. Further, other thermoplastic resins may be blended in appropriate amounts according to the purpose within the range not impairing the purpose of the present invention. Examples of the thermoplastic resin that can be blended include polyethylene, polypropylene, polystyrene, polycarbonate, polyester, polyamide and polyacetal.

It is also possible to add a thermosetting resin or a filler to the extent that the object of the invention is not impaired.
Examples of the thermosetting resin include phenol resin and epoxy resin. As the filler, graphite, carborundum, silica powder, molybdenum disulfide, wear resistance improving material such as fluororesin, glass fiber, aromatic polyamide fiber, alumina fiber, boron fiber, silicon carbide fiber, potassium titanate whiskers, Aluminum borate whiskers, carbon whiskers, asbestos, metal fibers, reinforcing materials such as ceramic fibers, antimony trioxide, magnesium carbonate, flame retardant improving materials such as calcium carbonate, carbon black, clay, electrical characteristics improving materials such as mica, Tracking resistance improver such as asbestos, silica, graphite, acid resistance improver such as barium sulfate, silica, calcium metasilicate, thermal conductivity improver such as iron powder, zinc powder, aluminum powder, copper powder, and other polybenzimidazoles Resin, silicone resin, glass beads, Torque, diatomaceous earth,
Alumina, Silasbaln, hydrated alumina, metal oxides,
Colorants, plasticizers, etc.

The resin composition of the present invention can be produced by a generally known method, but the following method is particularly preferable. (1) High heat resistant resin powder, carbon fiber mortar, Henshall mixer, drum blender, tumbler blender,
The mixture is premixed by using a ball mill, a ribbon blender, etc., and then kneaded by a generally known melt extruder, melt mixer, hot roll, etc., and then pelletized or powdered. (2) Highly heat-resistant resin powder is previously dissolved or suspended in an organic solvent, and carbon fibers are immersed in this solution or suspension,
After that, the solvent is removed in a hot air oven and then pelletized or powdered.

In this case, the solvent used is, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N.
-Dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone,
N-methylcaprolactam, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, bis [2- (2-
Methoxyethoxy) ethyl] ether, tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, pyridine, picoline, dimethyl sulfoxide, dimethyl sulfone, tetramethylurea, hexamethylphosphoramide and the like. These organic solvents may be used alone or in combination of two or more. The highly heat-resistant resin composition of the present invention is molded by a known molding method such as an injection molding method, an extrusion molding method, a compression molding method, or a transfer molding method, and put into practical use. The high heat resistant resin composition of the present invention thus molded has excellent mechanical properties, particularly mechanical properties at high temperatures, and can be used for machine parts, automobile parts and the like. Further, the mechanical properties of these molded products can be improved by heat treatment at an appropriate temperature for the purpose of removing residual stress and / or crystallization.

[0025]

EXAMPLES The production examples of the carbon fiber of the present invention and the high heat resistant resin composition using the same and the physical properties of the obtained resin composition will be described in detail below with reference to Examples and Comparative Examples. Example 1 An aromatic polyimide resin represented by the following formula [Formula 13] was dissolved in N-methyl-2-pyrrolidone to prepare a 5 wt% solution.
Acrylic carbon fiber whose surface was subjected to oxidation treatment was dipped in this solution, then dried at 300 ° C. to remove the solvent, and then 3
It was cut to a length of mm. The resin coating amount of the carbon fiber thus obtained was 6% by weight.

[0026]

[Chemical 13]

Example 2 A carbon fiber was produced in the same manner as in Example 1 except that the aromatic polyamic acid resin represented by the following chemical formula [Chemical Formula 14] was used. The resin coating amount of the obtained carbon fiber was 7% by weight.

[0028]

Embedded image

Example 3 The carbon fiber obtained in Example 1 and a polyether ether ketone resin PEEK 450P as a high heat resistant resin
(Mitsui Toatsu Chemical) was blended and mixed in the proportions shown in Table 1, and then melt-kneaded at 390 ° C. with an extruder having a diameter of 40 mm to obtain pellets. The pellets thus obtained were subjected to a cylinder temperature of 400 ° C. and a mold temperature of 180 using an ordinary injection molding machine.
Molded under conditions of ° C, various test pieces were obtained. Tensile strength (A
The results of flexural strength and flexural modulus (ASTM D-790), Izod impact strength (notched) (ASTM D-256) (according to STM D-638) are shown in Tables 1 and 2. The conditions for measuring physical properties in the following examples and comparative examples are the same as the conditions in this example.

Example 4 A molded article of a polyetheretherketone resin composition was prepared in the same manner as in Example 3 except that the carbon fiber obtained in Example 2 was used. Table 1 shows the measurement results of various physical properties.

Example 5 The carbon fiber obtained in Example 1 and the polyether sulfone resin PES 4100P (Mitsui Toatsu Chemical) as a highly heat resistant resin were blended and mixed in the proportions shown in Table-2, and then mixed.
The mixture was melt-kneaded at 360 ° C. with an extruder having a diameter of 40 mm to obtain pellets. The obtained pellets were molded using a normal injection molding machine under the conditions of a cylinder temperature of 370 ° C. and a mold temperature of 160 ° C. to obtain various test pieces. Table 2 shows the measurement results of various physical properties.

Example 6 The carbon fiber obtained in Example 1 and a polyetherimide resin Ultem 1000 (GE) as a high heat resistant resin
40 mm after being mixed and mixed in the proportions shown in Table-2.
Pellets were obtained by melt-kneading at 360 ° C with a diameter extruder. The obtained pellets were molded using a normal injection molding machine under the conditions of a cylinder temperature of 370 ° C. and a mold temperature of 160 ° C. to obtain various test pieces. Table 2 shows the measurement results of various physical properties.

Example 7 The carbon fiber obtained in Example 1 and the polyetherketone resin PEK 220 (ICI) as a high heat resistant resin were used.
After blending and mixing in the ratios shown in Table-2, the mixture was melt-kneaded at 390 ° C. by an extruder having a diameter of 40 mm to obtain pellets. The obtained pellets were molded using a normal injection molding machine under the conditions of a cylinder temperature of 400 ° C. and a mold temperature of 180 ° C. to obtain various test pieces. Table 2 shows the measurement results of various physical properties.

Example 8 The carbon fiber obtained in Example 1 and a polyimide resin Aurum PL450 (Mitsui Toatsu Kagaku) as a high heat resistant resin
40 mm after being mixed and mixed in the proportions shown in Table-2.
Pellets were obtained by melt-kneading at 410 ° C. using a diameter extruder. The obtained pellets were molded using a normal injection molding machine under the conditions of a cylinder temperature of 420 ° C. and a mold temperature of 190 ° C. to obtain various test pieces. Table 2 shows the measurement results of various physical properties.

Comparative Examples 1 to 5 In the same manner as in Examples 3 and 5 to 8, except that the carbon fiber coated with the aromatic polyimide resin was replaced with the acrylic carbon fiber bundled with the epoxy resin. Then, a test piece of the high heat resistant resin composition was molded. The measurement results of various physical properties are shown in Tables 1 and 2.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

EFFECT OF THE INVENTION The carbon fiber of the present invention has a high fiber reinforcing effect when blended with a high heat resistant resin, and has excellent mechanical properties and heat resistance originally possessed by the high heat resistant resin. Furthermore,
The high heat-resistant resin composition of the present invention has excellent mechanical properties, heat resistance, and chemical resistance, and therefore requires electrical / electronic parts, automobile parts, precision machine parts, and further medical equipment parts that require these physical properties. It is a very useful material used as a base material for aerospace aircraft, etc., and has a very great industrial application effect.

Front page continuation (72) Inventor Hiroyuki Furukawa 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (4)

[Claims] 1. A surface of an aromatic polyimide resin of the following formula (I) [Chemical formula 1] and / or a precursor of the aromatic polyamic acid resin of the formula (II) [Chemical formula 1] is used. Coated carbon fiber. Embedded image 2. An aromatic polyimide resin of formula (I) and / or an aromatic polyamic acid resin of formula (II), which is a precursor thereof, is dissolved in an organic solvent, and carbon fibers are immersed in the solution. The method for producing carbon fiber according to claim 1, which is obtained by drying. 3. 5 to 100 parts by weight of the carbon fiber of claim 1 and a melting point of 250 ° C. or higher or a glass transition temperature of 10
A high heat-resistant resin composition mainly composed of 100 parts by weight of a high heat-resistant resin at 0 ° C or higher. 4. A molded product using the high heat resistant resin composition according to claim 3.