JP2010168562A - Carbon fiber-reinforced polyimide benzoxazole composite - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon fiber-reinforced polyimide benzoxazole composite, which has a high elastic modulus and practically sufficient mechanical strength and is applicable as a heat-resistant sheet or a molded article improved in heat radiation property, for example, to a heat sink of a multilayer wiring board. <P>SOLUTION: The carbon fiber-reinforced polyimide benzoxazole composite is a composite of carbon fibers and polyimide benzoxazole obtained by the reaction of diamines having a benzoxazole skeleton and aromatic tetracarboxylic acids, wherein the carbon fibers are included in a mass ratio ranging from 30% to 60%. The carbon fiber-reinforced polyimide benzoxazloe composite has a coefficient of linear expansion of from -10 to +16 (ppm/°C) and not more than 40 μm warpage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a carbon fiber reinforced polyimide benzoxazole composite containing carbon fibers, which has a high elastic modulus and practically sufficient mechanical strength, and is also reinforced carbon fibers by heating and cooling with improved stiffness. The present invention relates to a carbon fiber reinforced polyimide benzoxazole composite that is used as a resin heat sink for electronic parts, as a structural material, a heat-resistant sheet, or the like that does not peel off from the polyimide resin.

The polyimide film is widely used as a flexible insulating material having heat resistance in the electric and electronic fields such as a flexible printed wiring board, COF, TAB, and LOC tape. Recently, a relatively thick polyimide film has been used as a reinforcing material for small and thin connector terminals used in small devices such as mobile phones.
In general, polymer materials have a low compressive modulus, so they tend to bend when bending stress is applied, and they have flexibility, but when high rigidity and stiffness are required, the choice of giving firmness by thickness is selected. I have to.
In general, a method of blending powder to increase the strength and elastic modulus of a material to form a powder-reinforced composite material is known. An idea of blending powder with polyimide resin (see Patent Document 1) has also been proposed. This document discloses an electronic component having a polyimide substrate characterized in that the polyimide substrate is made of a polyimide resin mixed with a filler, and the filler includes a high thermal conductivity material, a low linear expansion coefficient material, a magnetic material, Although a dielectric material is illustrated, there is no specific example. The liquid resin blended with the filler is screen-printed on some substrate, dried, heat-treated and cured, and is not intended to be a polyimide resin film containing the filler, and there is no disclosure regarding the strength of the material.
It cannot be said that the past has fully studied attempts to achieve a high stiffness by forming a film of a powder, particularly a polyimide resin containing extender pigments. When an extender pigment is blended at a high concentration to increase the stiffness, it becomes hard and fragile at the same time. The dispersion of the pigment is not uniform, and the strength of the film is lowered. In particular, during the film forming process, breakage or the like is likely to occur during hot air treatment and the productivity is not high. When the filler is blended at a high concentration, the smoothness of the film surface is lowered, and defects are likely to occur during metallization.
Many attempts have been made to solve the above-mentioned problems by compounding reinforcing fibers with polyimide resin (for example, see Patent Document 2).

  Further, a printed wiring board (refer to Patent Document 3) having less warpage and surface waviness obtained by impregnating an epoxy resin or the like into a fiber such as carbon fiber, or a first insulator having a first fiber layer formed in a planar shape. And a second insulator having a second fiber layer disposed on the first insulator and formed in a planar shape, and a conductor interposed between the first insulator and the second insulator. In addition, a coreless substrate with a fiber layer such as polybenzoxazole, wholly aromatic polyamide, or wholly aromatic polyester, and a resin layer that is a coreless substrate such as polyimide, aramid, and polyimidebenzoxazole (see Patent Document 4) are also disclosed ing.

Japanese Patent Laid-Open No. 07-335440 JP 09-055662 A JP 2001-144413 A JP 2008-085107 A

  Conventional high heat-resistant polyimide exhibits strength by increasing orientation by stretching, and in a system with a high concentration of filler, structural destruction occurs in the vicinity of the filler, and orientation does not progress, so a high strength film And sheets are difficult to obtain. Furthermore, in the case of carbon fiber reinforced polyimide composites that use polyimides that tend to break from the filler, and that have a difference in coefficient of linear expansion from the carbon fibers, problems such as peeling due to heating between the reinforcing fibers and the matrix polyimide As a result, defects such as insulation failure occur in printed circuit boards using these, and there has been a major problem in use and productivity.

  Compared to the conventional polyimide resin matrix where the dispersion of carbon fiber is uneven, the strength of the composite sheet etc. is reduced due to the difference in physical properties such as the linear expansion coefficient between the carbon fiber and the matrix, and the insulation polyimide in use is not good. By using a polyimide formed by polycondensation of an aromatic diamine having an oxazole structure and an aromatic tetracarboxylic acid in a matrix, this polyimide film is oriented in a self-organized manner, so that strength is easily developed, Film strength can be maintained even when a high concentration of filler is blended, and insulation is achieved by intrusion of moisture from the peeling space resulting from the fact that there is not much difference in linear expansion coefficient between carbon fiber and matrix resin. That can be used suitably for lightweight, high-strength structural materials and heat sinks. It has been reached.

３．線膨張係数が−１０〜＋１６ｐｐｍ／℃である１．〜２．いずれかのカーボン繊維補強ポリイミドベンゾオキサゾール複合体。
４．反りが４０μｍ以下である１．〜３．いずれかのカーボン繊維補強ポリイミドベンゾオキサゾール複合体。
５．１．〜４．いずれかのカーボン繊維補強ポリイミドベンゾオキサゾール複合体を使用した電子部品用の樹脂放熱板。 That is, this invention consists of the following structures.
1. A composite of a carbon fiber, a polyimide benzoxazole obtained by reacting a diamine having a benzoxazole skeleton and an aromatic tetracarboxylic acid, and the carbon fiber in the composite has a filament diameter of 1 to 20 μm A carbon fiber reinforced polyimide benzo, characterized in that it is a strand composed of 20 to 2000 filaments and / or a woven fabric comprising the strands, and the carbon fiber in the composite is contained in a mass ratio of 30% to 60%. Oxazole complex.
2. 1. The diamine having a benzoxazole skeleton is one or more selected from diamines represented by the following chemical formulas 1 to 4. Carbon fiber reinforced polyimide benzoxazole composite.

3. 1. Linear expansion coefficient is −10 to +16 ppm / ° C. ~ 2. Any carbon fiber reinforced polyimide benzoxazole composite.
4). 1. Warpage is 40 μm or less ~ 3. Any carbon fiber reinforced polyimide benzoxazole composite.
5.1. ~ 4. Resin heat sink for electronic parts using any carbon fiber reinforced polyimide benzoxazole composite.

  It is a composite of the carbon fiber of the present invention and a polyimide benzoxazole obtained by reacting a diamine having a specific benzoxazole skeleton and an aromatic tetracarboxylic acid, and the carbon fiber in the composite has a filament diameter of 1. Carbon fiber reinforced polyimide benzoxazole composite, particularly carbon, which is a strand or woven fabric having a filament number of 20 to 2000 and a carbon fiber in the composite in a mass ratio of 30% to 60%. Carbon fiber reinforced polyimide benzoxazole composites having a linear expansion coefficient of −10 to +16 (ppm / ° C.) or carbon fiber reinforced polyimide benzoxazole composites having a warp of 40 μm or less are carbon. Fiber dispersion It is easy to be uniform, there is little difference in physical properties such as linear expansion coefficient between carbon fiber and polyimide benzoxazole, which is a matrix resin, the strength of composite sheet etc. does not decrease, and it is due to peeling between reinforcing fiber and matrix resin in use Compared to the conventional polyimide resin matrix that causes poor quality, this polyimide can be obtained by using a polyimide made by polycondensation of aromatic diamines with specific benzoxazole structures and aromatic tetracarboxylic acids. Since it is oriented in a self-organized manner, it is easy to obtain strength, and the strength of the composite can be maintained even when the filler, which is a carbon fiber of reinforcing fiber, is blended in a high concentration. Intrusion of moisture etc. from the separation space that comes from the fact that there is not much difference between It owns superior performance as bonding failure hardly occurs, it can be used with the durability as a material for various electronic parts as such structural members and the heat radiating plate, it is industrially very effective.

The figure which shows the outline of the measuring method of curvature.

  A carbon fiber reinforced polyimide benzoxazole composite using a polyimide obtained by polycondensation (hereinafter, also referred to as polymerization) of a diamine having a benzoxazole structure of the present invention and an aromatic tetracarboxylic acid as a matrix is, for example, A polyamic acid solution obtained by polycondensation of aromatic diamines having one or two or more types of benzoxazole structures and aromatic tetracarboxylic acids in a solvent to carbon fibers such as carbon fiber fabrics. Cast or impregnate or mix and dry to form a polyamic acid self-supporting precursor composite (such as a green sheet or precursor sheet), which is imidized by high-temperature treatment to form a carbon fiber reinforced polyimide benzoxazole composite Obtained by a method of making a body (hereinafter also referred to as a complex) .

The method of adding carbon fiber to the polyamic acid solution is not particularly limited, for example, adding carbon fiber to the solvent, adding aromatic diamine having a benzoxazole structure and aromatic tetracarboxylic acid, and polycondensation A method of adding carbon fibers to a polyamic acid solution obtained by polycondensation of an aromatic diamine having a benzoxazole structure and an aromatic tetracarboxylic acid anhydride in a solvent, Also good.
As a preferred embodiment, a carbon fiber fabric is impregnated with a polyamic acid solution obtained by polycondensation of the aromatic diamine having the benzoxazole structure and the aromatic tetracarboxylic acid anhydride in a solvent, and this is impregnated. Examples thereof include a method in which the solvent is removed by means such as drying, and the resulting precursor composite is further treated at a high temperature to form a carbon fiber reinforced polyimide benzoxazole composite.
Specific examples of the diamine having a benzoxazole structure used in the carbon fiber reinforced polyimide benzoxazole composite of the present invention include the following.

Among these, amino (aminophenyl) benzoxazole isomers shown in Chemical Formulas 1 to 4 are preferable from the viewpoint of cost and ease of synthesis. Here, “each isomer” refers to each isomer in which two amino groups of amino (aminophenyl) benzoxazole are determined according to the coordination position (eg, the above “formula 1” to “formula 4”). Each compound described in the above. These diamines may be used alone or in combination of two or more.
In the present invention, it is preferable to use 80 mol% or more of the aromatic diamine having the benzoxazole structure.

The present invention is not limited to the above-mentioned matters, and the following aromatic diamines may be used, but preferably diamines having no benzoxazole structure exemplified below as long as the total aromatic diamine is less than 20 mol%. It is a polyimide film using one or two or more in combination.
Examples of such diamines include 4,4′-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, and bis [4- (3-aminophenoxy) phenyl]. Sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine.
3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide 4,4′-diaminodiphenyl sulfoxide, 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminobenzophenone, 3,4′- Diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane, 1 , 1-Bis [4- (4-aminophen Enoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] propane, 1,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, and the like Some or all of the hydrogen atoms on the aromatic ring in the aromatic diamine are halogen atoms, alkyl groups having 1 to 3 carbon atoms or alkoxyl groups, cyano groups, or some or all hydrogen atoms of alkyl groups or alkoxyl groups are halogens. It may be an aromatic diamine substituted with a C 1-3 halogenated alkyl group substituted with an atom or an alkoxyl group.

  The aromatic tetracarboxylic acids used in the present invention are, for example, aromatic tetracarboxylic anhydrides. Specific examples of the aromatic tetracarboxylic acid anhydrides include the following.

These tetracarboxylic dianhydrides may be used alone or in combination of two or more.
In the present invention, one or two or more non-aromatic tetracarboxylic dianhydrides exemplified below may be used in combination as long as they are less than 10 mol% of the total tetracarboxylic dianhydrides. Examples of such tetracarboxylic acid anhydrides include butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, and cyclobutanetetracarboxylic acid. Acid dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohex-1-ene-2,3 5,6-tetracarboxylic dianhydride, 3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3 -(1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride 1-ethylcyclohexane -(1,2), 3,4-tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane- Examples include 1- (2,3), 3- (2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, and the like. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  The solvent used when polyamic acid is obtained by polycondensation (polymerization) of the aromatic diamine and aromatic tetracarboxylic acid (anhydride) dissolves both the raw material monomer and the resulting polyamic acid. Although it will not specifically limit if it carries out, A polar organic solvent is preferable, for example, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, Examples thereof include N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoric amide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, and halogenated phenols. These solvents can be used alone or in combination. The amount of the solvent used may be an amount sufficient to dissolve the monomer as a raw material. As a specific amount used, the mass of the monomer in the solution in which the monomer is dissolved is usually 5 to 40% by mass, The amount is preferably 10 to 30% by mass.

Conventionally known conditions may be applied as conditions for the polymerization reaction (hereinafter also simply referred to as “polymerization reaction”) to obtain the polyamic acid. As a specific example, the temperature is 0 to 80 ° C. in an organic solvent. Stirring and / or mixing continuously for minutes to 30 hours. If necessary, the polymerization reaction may be divided or the temperature may be increased or decreased. In this case, the order of adding both monomers is not particularly limited, but it is preferable to add aromatic tetracarboxylic anhydrides to the solution of aromatic diamines. The mass of the polyamic acid in the polyamic acid solution obtained by the polymerization reaction is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and the viscosity of the solution is measured with a Brookfield viscometer (25 ° C.). And from the stability point of liquid feeding, Preferably it is 10-2000 Pa.s, More preferably, it is 100-1000 Pa.s.
The reduced viscosity (ηsp / C) of the polyamic acid in the present invention is not particularly limited, but is preferably 3.0 or higher, more preferably 4.0 or higher. It becomes easy to control the linear expansion coefficient of oxazole from −10 to +16 (ppm / ° C.).

Vacuum defoaming during the polymerization reaction is effective for producing a high-quality polyamic acid organic solvent solution. Moreover, you may perform superposition | polymerization by adding a small amount of terminal blockers to aromatic diamines before a polymerization reaction. Examples of the end capping agent include compounds having a carbon-carbon double bond such as maleic anhydride. The amount of maleic anhydride used is preferably 0.001 to 1.0 mole per mole of aromatic diamine.
In order to form the composite of the present invention from the polyamic acid solution obtained by the polymerization reaction, as described above, a method in which carbon fiber is added to the polyamic acid solution may be added. There is a method of adding and adding fibers.
In a preferred embodiment, the carbon fiber fabric is impregnated with a polyamic acid solution obtained by polycondensation of aromatic diamines having a benzoxazole structure and aromatic tetracarboxylic acid anhydrides in a solvent, and then dried. For example, a method may be used in which the solvent is removed by means such as the above, and the resulting precursor composite is further treated at a high temperature to form a carbon fiber reinforced polyimide benzoxazole composite.

As an imidization method by high-temperature treatment, a conventionally known imidation reaction can be appropriately used. For example, using a polyamic acid solution that does not contain a ring-closing catalyst or a dehydrating agent, the imidization reaction proceeds by subjecting it to a heat treatment (so-called thermal ring-closing method), or the polyamic acid solution contains a ring-closing catalyst and a dehydrating agent. In particular, a chemical ring closing method in which an imidization reaction is performed by the action of the above ring closing catalyst and a dehydrating agent can be given.
The heating maximum temperature of the thermal ring closure method is exemplified by 100 to 500 ° C, preferably 200 to 480 ° C. When the maximum heating temperature is lower than this range, it is difficult to close the ring sufficiently, and when it is higher than this range, the deterioration proceeds and the composite tends to become brittle. A more preferable embodiment includes a two-stage heat treatment in which treatment is performed at 150 to 250 ° C. for 3 to 20 minutes and then treatment is performed at 350 to 500 ° C. for 3 to 20 minutes.
In the chemical ring closure method, after the polyamic acid solution is mixed with the carbon fiber, the imidization reaction is partially advanced to form a precursor complex having self-supporting property, and then imidation is completely performed by heating. it can. In this case, the condition for partially proceeding with the imidization reaction is preferably a heat treatment for 3 to 20 minutes at 100 to 200 ° C., and the condition for causing the imidization reaction to be completely performed is preferably 200 to 400 ° C. For 3 to 20 minutes.

The thickness of the carbon fiber reinforced polyimide benzoxazole composite when used in the form of a sheet is not particularly limited, but is usually 20 to 3000 μm, preferably 25 to 1000 μm, considering that it is used for a heat sink described below. When used as a stiffener, the thickness is preferably 15 to 300 μm, more preferably 25 to 250 μm, and still more preferably 50 to 150 μm. This thickness can be easily controlled by the volume and thickness of the carbon fiber body to be impregnated with the polyamic acid solution, the coating amount during coating, and the concentration of the polyamic acid solution.
The carbon fiber in the present invention is not particularly limited as long as it is a known carbon fiber and used for reinforcement, and has the same linear expansion coefficient and tensile elastic modulus as those, but the linear expansion coefficient is 0 to 0. Carbon fibers in the range of 10 ppm / ° C. are preferred. For example, those known by trade names such as Kureka (manufactured by Kureha Chemical), Pyrofil (manufactured by Mitsubishi Rayon), Dyalead (manufactured by Mitsubishi Chemical), Trading Card (manufactured by Toray), Almax (manufactured by Mitsui Mining Materials) It is done.
In a preferred embodiment of the present invention, a carbon fiber reinforced polyimide benzoxazole composite having carbon fibers in a mass ratio of between 30% and 60%, and the carbon fiber has a filament diameter of 1 to 20 μm and a filament number of 20 to 2000. The carbon fiber reinforced polyimide benzoxazole composite, which is a ceramic fabric using ceramic long fibers, and the carbon fiber have a filament diameter of 1 to 20 μm, more preferably 3 to 20 μm, and the number of filaments of 20 to 2000, more preferably 100 to 2000. And carbon fiber reinforced polyimide benzoxazole composites, which are ceramic long fiber strands. The mass ratio of the carbon fibers is 30 to 60 mass%, more preferably 35 to 60 mass%, based on the carbon fiber reinforced polyimide benzoxazole composite. If it is less than 30% by mass, the reinforcing effect by the carbon fiber is not sufficient, and if it exceeds 60% by mass, it is often difficult to mold.
The average fiber length of the carbon fibers is 6 mm or more, preferably 10 mm or more, and the average carbon fiber diameter is 1 to 20 μm. If the average fiber length is 6 mm or less and the average fiber diameter exceeds 20 μm, the reinforcing effect by the carbon fibers may be insufficient. Here, the average fiber length or average fiber diameter of carbon fibers refers to an average value of 100 fiber lengths or fiber diameters of 100 or more fibers observed with a microscope.

The linear expansion coefficient (CTE) in the present invention is measured as follows.
<Measurement of linear expansion coefficient>
About the measurement object, the expansion / contraction rate in the MD direction and the TD direction is measured under the following conditions, and the expansion / contraction rate / temperature at intervals of 90 ° C. to 100 ° C., 100 ° C. to 110 ° C.,. Was performed up to 400 ° C., and the average value of all measured values from 100 ° C. to 350 ° C. was calculated as CTE (average value).
Device name: TMA4000S manufactured by MAC Science
Sample length; 10mm
Sample width: 2 mm
Initial load: 34.5 g / mm ²
Temperature rise start temperature: 25 ° C
Temperature rising end temperature: 400 ° C
Temperature increase rate: 5 ° C / min
Atmosphere; Argon The CTE of the sheet-like carbon fiber reinforced polyimide benzoxazole composite in which the linear expansion coefficient of the carbon fiber reinforced polyimide benzoxazole composite is −10 to +16 (ppm / ° C.), which is a preferred embodiment of the present invention, is more Preferably, it is 0-10 (ppm / degreeC). The use of CTE-containing polyimide benzoxazole, which is less dissimilar than the CTE of the carbon fibers used, is the purpose of the present invention, and peeling occurs when receiving a thermal history between the carbon fibers and the matrix resin. It will be difficult.

The warpage in the present invention is measured as follows.
A sheet-like sample was cut into a size of 5 mm × 35 mm to obtain a test piece. The warpage means the degree of deformation in the thickness direction with respect to the surface direction. Specifically, as shown in FIG. 1, a 5 mm × 35 mm test piece is fixed to a sample fixing base, and 30 mm from the sample fixing base. An overhanging cantilever was used. When the 5mm, 15mm, and 25mm parts are measured with a non-contact laser length meter (Keyence LK-G85) and the measured values are A, B, and C, respectively, (A + C) / 2-B Was the amount of warpage. A total of 10 points were sampled, and the measured value was an average value of 10 points.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited by a following example. In addition, the evaluation methods of physical properties in the following examples are as follows except for those described above.

1. Reduced viscosity of polyamic acid (ηsp / C)
A solution dissolved in N-methyl-2-pyrrolidone (or N, N-dimethylacetamide) so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. with an Ubbelohde type viscosity tube. (When the solvent used for preparing the polyamic acid solution was N, N-dimethylacetamide, the polymer was dissolved using N, N-dimethylacetamide and measured.)
2. The thickness of the polyimide composite was measured using a micrometer (Finereuf, Millitron (registered trademark) 1245D).

3. Thermal radiation characteristics Thermal radiation characteristics confirm the ability to remove heat when the composite is used as a heat sink for electronic components. Each composite obtained in Examples and Comparative Examples was cut into 30 mm squares to form a heat sink, and was attached to a T0-2 type power transistor that was upright by a support, and applied power to this power transistor. Heat was generated by flowing 3.85 (W) to measure the temperature rise temperature t1 after 10 minutes, and the temperature rise temperature t2 after 10 minutes at a position 5 mm away from the heat radiating plate was measured to evaluate the thermal radiation characteristics.

4). Judgment of formability By visually observing the appearance of the composite, it was judged as x when an appearance defect such as protrusion of carbon fiber was seen, and as ◯ when there was no such abnormality.
5). Thermal history test
Each cycle was carried out at 125 ° C. and −55 ° C. for 30 minutes and 300 cycles, and thereafter, peeling, fiber jumping, and bulging defects were visually determined.

[Reference Example 1]
(Preparation of polyamic acid solution)
The inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer and a stirring rod was purged with nitrogen, and then 223 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole and 4416 parts by mass of N, N-dimethylacetamide were added. After complete dissolution, 217 parts by mass of pyromellitic dianhydride was added and stirred at a reaction temperature of 26 ° C. for 33 hours to obtain a brown and viscous polyamic acid solution A. The reduced viscosity (ηsp / C) of this product was 4.1.

[Reference Example 2]
(Preparation of polyamic acid solution)
The inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 200 parts by mass of diaminodiphenyl ether was added. Next, after 2190 parts by mass of N-methyl-2-pyrrolidone was added and completely dissolved, the preliminary dispersion obtained above and 217 parts by mass of pyromellitic dianhydride were added and the mixture was stirred at 26 ° C. for 6 minutes. When stirred for a period of time, a white brown viscous extender pigment-dispersed polyamic acid solution B was obtained. This reduced viscosity (ηsp / C) was 3.0.

* Examples 1-4 and Comparative Examples 1-4
A composite was prepared using the polyamic acid solution obtained in Reference Examples 1 and 2 under reduced pressure for 24 hours and the following carbon fiber fabric.
Each carbon fiber fabric is dipped and impregnated in a polyamic acid solution, and the carbon fiber impregnated with the polyamic acid solution is pulled up vertically from the polyamic acid solution, and excess polyamic acid solution is squeezed out between the rolls, and 110 ° C. in a vertical state. A polyimide precursor composite was prepared by drying in hot air, and the polyimide precursor composite was heat-treated in each hot air dryer at 120 ° C., 200 ° C., and 450 ° C. to obtain each carbon fiber reinforced polyimide composite.
Table 1 shows the evaluation of the heat radiation plate using the polyamic acid solution used, the carbon fiber fabric used, and the obtained carbon fiber reinforced polyimide (benzoxazole) composite in each example and each comparative example.

Carbon fiber fabric 1; filament diameter of about 7 μm, number of filaments of 1000,
Vertical and horizontal thread density: 12 / inch, width: 12 / inch,
Plain weave, weight 64g / m ² , thickness 0.13mm

Carbon fiber fabric 2; filament diameter of about 10 μm, number of filaments of 1000,
Vertical and horizontal thread density: 20 / inch, width: 19 / inch,
Plain weave, weight 200g / m ² , thickness 0.41mm

In the fabrics 1 and 2, each single fiber is a fiber with no disconnection on the way.

  As described above, the carbon fiber reinforced polyimide benzoxazole composite of the present invention has a high elastic modulus and practically sufficient mechanical strength, and as a heat-resistant sheet or molded article with improved durability insulation, As a primary structural material for electronic component heat sinks and airplanes-main wing, vertical, horizontal tail, secondary structural material-auxiliary wing, rudder, elevator, nozzle cone, motor case, interior material-seat, table, other equipment Tube truss structure, solar panel, medical equipment, film cassette, X-ray grid, wheelchair structural material, inner revere, heald frame, leaf spring, machine tool head, robot arm, centrifuge rotor, uranium enrichment cylinder , Various rollers, shafts, pots for manufacturing human silk, parabolic antennas, battery components, radar, acoustic speaker cones, computer Notebook PCs, PC-related equipment, telephones, mobile phones, office equipment, communication equipment casings, golf shafts, faces, heads, tennis rackets, badminton rackets, yachts, cruisers, boats, masts, ladders, baseball bats, skis , Stock, bow equipment, kendo bamboo sword, lighter, rigid, vibration damping, drive shafts for automobiles, engine parts, spoilers, racing car bodies, linear motor car bodies, bicycle frames, disc wheels, rims, handles, Stirrers, pipes, tanks, pit floors in actuators such as actuators, cylinders, cylinders, and chemical equipment in pressure vessels, CF composite cables in civil engineering construction, concrete reinforcement members and furniture, western umbrellas, helmets, gears such as clock gears, Mechanical parts such as camera bodies, notebook PC cases, computer peripherals, household electrical appliances, structural parts such as cases of office machines such as copiers, printers, and fax machines, automotive electrical parts, connector radiator grills, lamp housings, etc. It can be widely applied and has great industrial value.

1: Specific contact laser displacement meter 2: Sample 3: Sample fixing base

Claims (5)

A composite of carbon fiber, polyimide benzoxazole obtained by reacting a diamine having a benzoxazole skeleton and an aromatic tetracarboxylic acid, and the carbon fiber in the composite has a filament diameter of 1 to 20 μm A carbon fiber reinforced polyimide benzo, characterized in that it is a strand composed of 20 to 2000 filaments and / or a woven fabric composed of the strands, and the carbon fiber in the composite is contained in a mass ratio of 30% to 60%. Oxazole complex. The carbon fiber-reinforced polyimide benzoxazole composite according to claim 1, wherein the diamine having a benzoxazole skeleton is one or more selected from diamines represented by the following chemical formulas 1 to 4.

The carbon fiber-reinforced polyimide benzoxazole composite according to any one of claims 1 to 2, having a linear expansion coefficient of -10 to +16 ppm / ° C. The carbon fiber reinforced polyimide benzoxazole composite according to any one of claims 1 to 3, wherein the warp is 40 µm or less. The resin heat sink for electronic components using the carbon fiber reinforcement polyimide benzoxazole composite in any one of Claims 1-4.

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