JPH07310286A - Carbon fiber for reinforcing highly heat-resistant resin and its resin composition - Google Patents

Abstract

PURPOSE:To obtain a carbon fiber capable of manifesting excellent fiber reinforcing effects on reinforcement of a highly heat-resistant resin by coating the surface of the carbon fiber with an aromatic polyethereal resin. CONSTITUTION:This carbon fiber for reinforcing highly heat-resistant resin has the surface thereof coated with an aromatic polyethereal resin having a recurring unit expressed by the formula (X is a <=30C aromatic group). The carbon fiber coated with this resin is obtained by immersing the carbon fiber in a solution prepared by dissolving the aromatic polyethereal resin in an organic solvent such as N,N-dimethylformamide and then drying the resultant fiber. This highly durable resin composition is prepared by mixing 5-100 pts.wt. resultant carbon fiber with 100 pts.wt. highly heat-resistant resin having >=250 deg.C melting point or >=100 deg.C glass transition point, e.g. an aromatic polyether sulfone or an aromatic polyether imide. The obtained resin composition is excellent in mechanical strength and heat resistance.

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 handling properties, carbon fibers are usually used in the form of resin coated and bundled. As the sizing agent, an epoxy resin or a polyamide resin (JP-A-53-106752) is usually used.
3 is required for molding the above high heat resistant resin and its resin composition.
A high temperature of 00 ° C or higher is required. 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 high heat-resistant resin, the sizing agent will undergo thermal decomposition 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.

[0004]

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 and heat resistance.

[0005]

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 relates to 1) carbon fiber whose surface is coated with an aromatic polyether resin, and 2) the aromatic polyether resin described above is of the formula (I), for example.
The carbon fiber as described in 1) above, which has a repeating structural unit such as

[0006]

[Chemical 2] (X represents an aromatic group having 30 or less carbon atoms.) 3) Dissolving an aromatic polyether resin in an organic solvent, immersing the carbon fiber in the solution, and then drying 1). The method for producing a carbon fiber described in 4), 5) 100 parts by weight of the carbon fiber described in 1), and T
It is a high heat-resistant resin composition mainly composed of 100 parts by weight of a high heat-resistant resin having m (melting point) of 250 ° C. or higher or Tg (glass transition temperature) of 100 ° C. or higher, and a molded product using them.

That is, the carbon fiber of the present invention and the high heat-resistant resin composition using the same are characterized in that an aromatic polyether resin is used as a sizing agent for the carbon fiber. A high heat-resistant resin composition containing carbon fibers having a sufficient reinforcing effect and the carbon fibers, which has excellent mechanical properties and heat resistance. 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. In the present invention, the aromatic polyether resin used for coating the carbon fiber as the sizing agent is preferably a resin having a structure represented by the following formula (Formula 3).

[0008]

[Chemical 3] (X represents an aromatic group having 30 or less carbon atoms.) Specific examples of the aromatic polyether resin include those represented by the following formula (Formula 4),

[Chemical 4] (Where X is, for example, the following formula (Formula 5)

[0009]

[Chemical 5] Represents However, R is H, an alkyl group having 1 to 4 carbon atoms,
It represents an alkoxy group having 1 to 4 carbon atoms or halogen. ) Or the following formula (Formula 6).

[0010]

[Chemical 6] It represents an isopropylidene group or a hexafluoroisopropylidene group, and R represents H, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or halogen. As a more preferable aromatic polyether resin, those in which X in the formula (I) is a metaphenylene group and / or a group of the chemical formula 7 are particularly excellent in the present invention.

[0011]

[Chemical 7] These aromatic polyether resins are used alone or in combination of two or more. The carbon fiber of the present invention and the high heat-resistant resin composition using the same are characterized by using an aromatic polyether resin as a sizing agent for the carbon fiber, and a high heat-resistant resin using the same. Although it is a composition, it can be used as a sizing agent by mixing another resin with the aromatic polyether resin as long as the excellent performance of the carbon fiber is not impaired.

Examples of the resin 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 type, pitch type, rayon type, lignin type 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, it is a method of immersing the carbon fiber in a solution in which an aromatic polyether resin is dissolved in an organic solvent, and then drying it to remove the solvent.

The solvent used varies depending on the kind of the aromatic polyether resin, but 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, dimethylsulfoxide, dimethylsulfone, sulfolane, tetramethylurea, hexa Methylphosphoramide, pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine, 2,6-lutidine, quinoline, isoquinoline, acetophenone, anisole, phenetole, benzyl ether, phenyl ether, 1,
2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, benzene, toluene, o-xylene, m-xylene, p-xylene, diphenyl, terphenyl, benzyl chloride. , Nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, chlorobenzene,
2-chlorotoluene, 3-chlorotoluene, 4-chlorotoluene, o-dichlorobenzene, p-dichlorobenzene, bromobenzene, 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, o-bromophenol, p-bromophenol, o-fluorophenol, p-fluorophenol and the like. Further, these solvents may be used alone or in combination of two or more depending on the kind of the aromatic polyether 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 has a coating amount of the aromatic polyether resin of 0.05 to 20% by weight based on the fiber,
Preferably 0.1 to 15% by weight, more preferably 3 to
It is suitable to be 10% by weight. If the amount is less than 0.05% by weight, the effect of the present invention cannot be obtained, and if the amount is more than 20% by weight, the mechanical properties cannot be expected to be further improved, so that it is meaningless.

In the resin composition of the present invention, 5 to 100 parts by weight of carbon fiber is suitable for 100 parts by weight of the high heat resistant resin. It is preferably 10 to 70 parts by weight, more preferably 20 to 60 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.
The glass transition temperature is preferably 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 poly sulfone, 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 (Tg;
225 ° C, Tm; none),

[0018]

[Chemical 8] The aromatic polyether imide has the structure of the formula (III) (Chem. 9) (Tg; 215 ° C., Tm; none),

[0019]

[Chemical 9] The aromatic polysulfone is represented by the formula (IV)
Of the structure (Tg; 190 ° C., Tm; none),

[0020]

[Chemical 10] The aromatic polyimide has a structure of the formula (V) (Chemical Formula 11) (Tg; 170 to 260 ° C., Tm; none to 390).
℃),

[0021]

[Chemical 11] However, in the formula (V), Z is one or two or more groups (Formula 12) selected from the group consisting of the following formulas.

[0022]

[Chemical 12] The Y is a direct _{bond, -SO 2 -, - CO -} , - C (C
H _{3) 2} - or -S-. The aromatic polyphenylene sulfide has a structure of formula (VI) (Chemical Formula 13) (Tg; 88 ° C., Tm; 285 ° C.),

[0023]

[Chemical 13] The aromatic polyether ether ketone has the formula (VI
I) having the structure of (Chemical formula 14) (Tg; 143 ° C., Tm;
334 ° C),

[0024]

[Chemical 14] The aromatic polyether ketone has the formula (VIII)
Having the structure of (Chemical Formula 15) (Tg; 154 ° C., Tm; 36
7 ° C),

[0025]

[Chemical 15] The aromatic polyether ketone ether ketone ketone has a structure of formula (IX) (Chemical Formula 16) (Tg; 173).
℃, Tm; 380 ℃),

[0026]

[Chemical 16] The aromatic polyether has the structure of formula (X) (Chemical formula 17) (Tg; 145 ° C., Tm; 340 ° C.),

[0027]

[Chemical 17] And so on.

Further, within a range not impairing the object of the present invention,
Other thermoplastic resins may be blended in appropriate amounts depending on the purpose. Examples of the thermoplastic resin that can be blended include polyethylene, polypropylene, polystyrene, polycarbonate, polyester and polyamide. It is also possible to add a thermosetting resin or a filler to an extent that the object of the invention is not impaired. Examples of the thermosetting resin include phenol resin, epoxy resin, polybenzimidazole resin and the like. 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, Reinforcing materials such as aluminum borate whiskers, carbon whiskers, asbestos, metal fibers, ceramic fibers, flame retardant improving materials such as antimony trioxide, magnesium carbonate, calcium carbonate, etc., electrical property improving materials such as clay and mica, asbestos, silica , Graphite and other tracking resistance improvers, barium sulfate, silica, calcium metasilicate etc. acid resistance improvers, iron powder, zinc powder, aluminum powder, copper powder etc. thermal conductivity improvers, other glass beads, talc, silica Algae earth, alumina, silasbaln, hydrated alumina, metal Products, colorants, plasticizers, and the like. These may be used alone or in admixture of two or more.

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, 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, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, bis [2- (2 -Methoxyethoxy) ethyl] ether, tetrahydrofuran, 1,3-
Examples thereof include 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 molded in this manner has excellent mechanical properties, particularly mechanical properties at high temperatures,
It can be used for machine parts, automobile parts, etc. 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.

[0031]

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 Polyether nitrile resin (ID manufactured by Idemitsu Petrochemical Co., Ltd.
300) was dissolved in p-chlorophenol to prepare a 5% by weight solution. An acrylic carbon fiber whose surface was subjected to an oxidation treatment was immersed in this solution, dried at 300 ° C. to remove the solvent, and then cut into a length of 3 mm. The resin coating amount of the carbon fiber thus obtained was 8% by weight.

Example 2 A resin having a structure represented by the following formula (Formula 18) was used as the aromatic polyether resin, and the aromatic polyether resin was coated in the same manner as in Example 1. Carbon fiber was produced. The resin coating amount of the obtained carbon fiber was 6% by weight.

[0033]

[Chemical 18] Example 3 A carbon fiber coated with an aromatic polyether resin was prepared in the same manner as in Example 1 except that a resin having a structure represented by the following formula (Formula 19) was used as the aromatic polyether resin. Manufactured. The resin coating amount of the carbon fiber thus obtained was 5% by weight.

[0034]

[Chemical 19] Example 4 The carbon fiber obtained in Example 1 and a polyether ether ketone resin PEEK 450P as a high heat resistant resin
(Mitsui Toatsu Kagaku) was blended and mixed in the proportions shown in Table 1, and then melt-kneaded at 400 ° C. with an extruder having a diameter of 40 mm to obtain pellets. The pellets thus obtained were subjected to a cylinder temperature of 410 ° 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 5 A molded article of a polyetheretherketone resin composition was prepared in the same manner as in Example 4, except that the carbon fiber obtained in Example 2 was used. Table 1 shows the measurement results of various physical properties.

Example 6 A molded article of a polyetheretherketone resin composition was prepared in the same manner as in Example 4, except that the carbon fiber obtained in Example 3 was used. Table 1 shows the measurement results of various physical properties.

Example 7 The carbon fiber obtained in Example 1 and the polyether sulfone resin PES 4100P (Mitsui Toatsu Chemical) as a high 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 8 The carbon fiber obtained in Example 1 and a polyetherimide resin Ultem 1000 (GE company) 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 9 The carbon fiber obtained in Example 1 and the polyetherketone resin PEK 220 (ICI) as a highly heat-resistant resin were used.
After blending and mixing in the ratios shown in Table 2, pellets were obtained by melt-kneading at 400 ° C. with an extruder having a diameter of 40 mm. The obtained pellets were molded using a normal injection molding machine under the conditions of a cylinder temperature of 410 ° C. and a mold temperature of 180 ° C. to obtain various test pieces. Table 2 shows the measurement results of various physical properties.

Example 10 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 420 ° C. using a diameter extruder. Using an ordinary injection molding machine for the obtained pellets,
Molding was performed 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.
Shown in.

Comparative Examples 1 to 5 The same as Examples 4 and 7 to 10 except that the carbon fiber coated with the aromatic polyether resin was replaced with the acrylic carbon fiber bundled with the epoxy resin. A test piece of the high heat-resistant resin composition was molded by the method of 1. The measurement results of various physical properties are shown in Tables 1 and 2.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

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 is excellent in mechanical properties and heat resistance, and therefore requires electrical / electronic parts, automobile parts, precision machine parts, and further medical equipment parts, which require these physical properties.
It is an extremely useful material used as a base material for spacecraft, and has a very large industrial application effect.

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

Claims (5)

[Claims] 1. A carbon fiber whose surface is coated with an aromatic polyether resin. 2. The carbon fiber according to claim 1, wherein the aromatic polyether resin has a repeating structural unit represented by the formula (I) (Formula 1). [Chemical 1] (X represents an aromatic group having 30 or less carbon atoms.) 3. The method for producing carbon fiber according to claim 1, which is obtained by dissolving an aromatic polyether resin in an organic solvent, immersing the carbon fiber in the solution, and then drying. 4. Mainly composed of 5 to 100 parts by weight of the carbon fiber according to claim 1 and 100 parts by weight of a high heat resistant resin having a Tm (melting point) of 250 ° C. or higher or a Tg (glass transition temperature) of 100 ° C. or higher. High heat resistant resin composition. 5. A molded product using the high heat resistant resin composition according to claim 4.