JP2019167501A - Prepreg and composite material plate - Google Patents

Abstract

To provide a prepreg that is excellent in handleability because of having an excellent drape property, and that can yield a formed article having an excellent mechanical property.SOLUTION: Provided is a prepreg comprising a thermoplastic resin, and a carbon fiber cloth constructed of a warp carbon fiber bundle and a weft carbon fiber bundle, and in which the impregnation ratio of the thermoplastic resin into the carbon fiber bundle is 85% or more, the prepreg has portions in which the warp carbon fiber bundle and the weft carbon fiber bundle overlap each other, and there are voids in which the thermoplastic resin is not present, in the overlapping portion.SELECTED DRAWING: None

Description

  The present invention relates to a prepreg and a composite material plate. More specifically, the present invention relates to a prepreg and a composite material plate, which are prepregs having excellent drapeability and excellent handleability and capable of producing a molded product having excellent mechanical properties.

  In recent years, composite materials using carbon fibers as reinforcing fibers have been widely used in sports and leisure applications, industrial applications, aerospace fields, and medical fields by utilizing their high specific strength and specific rigidity. These composite materials are often molded through a prepreg which is an intermediate base material in which a reinforcing fiber is impregnated with a matrix resin.

  In the past, the use of thermosetting resin as the matrix resin has been the mainstream, but in recent years, the use of thermoplastic resin as the matrix resin and the use of composite materials are increasing, and the thermoplastic resin is used as the matrix resin. In addition to obtaining a composite material excellent in impact resistance, there is an advantage that the molding time can be shortened (Patent Document 1).

  When forming the prepreg, which is an intermediate substrate, into a molded product, the prepreg is preformed along a mold and then heated and pressurized, but when the matrix resin is a thermoplastic resin, the prepreg is a rigid sheet In some cases, it is difficult to form a complex shape with poor drapability. In particular, when the reinforcing fiber of the prepreg is in the form of a woven fabric, the thickness of the prepreg increases and the rigidity of the prepreg increases, so that the drapability tends to decrease extremely.

  Patent Document 2 discloses a prepreg that is excellent in drapability by partially impregnating a reinforcing fiber with a thermoplastic resin and having a thermoplastic resin layer having irregularities on the surface of the prepreg. When the matrix resin is a thermosetting resin, the reinforcing fiber in the unimpregnated part is used as the air degassing path, and when molding is performed at a relatively low pressure, the matrix resin is completely impregnated with the reinforcing fiber by removing the air during molding. However, it is also possible (Patent Document 3). However, when the matrix resin is a thermoplastic resin, the resin viscosity at the time of melting is much higher than that of the thermosetting resin. Therefore, in order to obtain a molded product with less voids using a prepreg having a part-impregnated portion. Therefore, it is necessary to maintain the pressure and temperature at a higher pressure and a higher temperature for a longer time, and it has been difficult to remove the void in the non-impregnated portion of the prepreg at the time of molding. That is, the prepreg drapeability is improved by partially impregnating the reinforced fiber with the matrix resin, but the molded product formed using this prepreg has a lot of voids and exhibits sufficient mechanical properties. It was difficult.

  On the other hand, Patent Document 4 discloses that when a polycarbonate resin having a specific molecular structure unit is used as a matrix resin and impregnated into a reinforced fiber aligned in one direction, excellent impregnation properties are expressed. ing. However, since the prepreg disclosed in Patent Document 4 has excellent impregnation property of the matrix resin to the reinforcing fibers, there are few unimpregnated portions, and there is a problem that the prepreg drape property is lacking.

JP-A-9-155862 JP 2010-202824 A JP-T-2001-511827 JP 2014-133841 A

  The subject of this invention is providing the prepreg which can manufacture the molded article which is excellent in handling property by having the outstanding drape property, and excellent in a mechanical physical property.

・・・式（１）
（６） 前記炭素繊維織物の目付が２００〜６５０ｇ／ｍ^２である、上記（１）から（５）のいずれかに記載のプリプレグ。
（７） 前記プリプレグのドレープ値が１〜５ｃｍである、上記（１）から（６）のいずれかに記載のプリプレグ。
（８） 上記（１）から（６）のいずれかに記載のプリプレグを積層して一体化してなる炭素繊維複合材料板。
（９） 前記炭素繊維複合材料板の繊維体積含有率ＶｆおよびＪＩＳ Ｋ７０７４に準拠して測定される３点曲げ強度σ（ＭＰａ）が下記式（２）を満たす、上記（８）に記載の複合材料板。
４００（ＭＰａ） ≦ ４２×σ÷Ｖｆ ≦ １２００（ＭＰａ） ・・・式（２） As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by allowing a gap without the thermoplastic resin to exist in the overlapping portion of the warp and weft constituting the carbon fiber fabric. The present invention has been completed. That is, the gist of the present invention resides in the following (1) to (9).
(1) A carbon fiber fabric comprising a carbon fiber bundle of warps and a carbon fiber bundle of wefts and a thermoplastic resin, wherein the impregnation ratio of the thermoplastic resin into the carbon fiber bundle is 85% or more, A prepreg having a portion in which the carbon fiber bundle of the weft and the carbon fiber bundle of the weft overlap, and having a void without the thermoplastic resin in the overlapping portion.
(2) The prepreg according to (1) above, wherein the height of the gap in the direction perpendicular to the surface of the prepreg is 10 to 100 μm.
(3) The prepreg according to the above (1) or (2), wherein 80% or more of all voids in the prepreg are present between the carbon fiber bundle of the yarn and the carbon fiber bundle of the weft.
(4) The prepreg according to any one of (1) to (3), wherein the thermoplastic resin is a polycarbonate resin.
(5) The prepreg as described in said (4) in which the said polycarbonate resin contains the unit structure derived from the compound represented by following formula (1).

... Formula (1)
(6) The prepreg according to any one of (1) to (5), wherein the basis weight of the carbon fiber fabric is 200 to 650 g / m ² .
(7) The prepreg according to any one of (1) to (6), wherein the prepreg has a drape value of 1 to 5 cm.
(8) A carbon fiber composite material plate obtained by laminating and integrating the prepreg according to any one of (1) to (6) above.
(9) The composite according to (8), wherein a three-point bending strength σ (MPa) measured according to fiber volume content Vf of the carbon fiber composite material plate and JIS K7074 satisfies the following formula (2): Material board.
400 (MPa) ≦ 42 × σ ÷ Vf ≦ 1200 (MPa) (2)

  The prepreg of the present invention is excellent in draping properties and can be preformed even in complicated shapes. Even when the prepreg is molded at a relatively low pressure, the voids of the molded product are reduced, and the mechanical properties are excellent. A molded product can be obtained.

  The prepreg of the present invention comprises a carbon fiber fabric composed of a carbon fiber bundle of warp and a carbon fiber bundle of weft and a thermoplastic resin, and the impregnation rate of the thermoplastic resin into the carbon fiber bundle is 85% or more. , The warp carbon fiber bundle and the weft carbon fiber bundle overlap each other, and the overlap portion does not contain the thermoplastic resin (hereinafter referred to as “void of thermoplastic resin” is simply referred to as “void”). ) Is a prepreg.

  The prepreg of the present invention has a portion in which the carbon fiber bundle of the warp and the carbon fiber bundle of the weft overlap each other, and has an air gap in the overlapping portion (between the carbon fiber bundle of the warp and the carbon fiber bundle of the weft). Expresses drape. The gap preferably has a thickness (height) in the direction perpendicular to the surface of the prepreg of 10 to 100 μm. If it is 10 micrometers or more, it will be easy to express the excellent drape property. If it is 100 μm or less, voids are lost during molding of the prepreg described later, and the mechanical properties of the molded product after molding are easily developed. More preferably, the thickness (height) of the gap prepreg in the direction perpendicular to the plane is 15 to 50 μm, more preferably 20 to 40 μm, and most preferably 25 to 35 μm.

  It is known that prepregs with many voids and low impregnation properties are generally excellent in drapability, but generally voids in reinforcing fiber bundles can be removed during molding once they are closed. It is also difficult. By making the impregnation rate of the thermoplastic resin into the carbon fiber bundle in the prepreg of the present invention 85% or more, it is possible to suppress a decrease in mechanical properties due to residual voids in the molded product, and to exhibit excellent mechanical properties. It becomes easy to obtain a molded product.

  In the prepreg of the present invention, the prepreg of the prepreg is secured between the carbon fiber bundle of the warp and the carbon fiber bundle of the weft, thereby ensuring the draping property of the prepreg and existing between the carbon fiber bundle of the warp and the carbon fiber bundle of the weft. Since air can be easily removed during molding, voids do not remain in the molded product, and excellent mechanical properties can be expressed. In order to obtain the effects of the present invention, the prepreg of the present invention preferably has 80% or more of the total voids in the prepreg between the carbon fiber bundle of the warp and the carbon fiber bundle of the weft. More preferably, it is 85% or more, more preferably 90% or more, and most preferably 95% or more.

  The form of the reinforcing fiber of the prepreg of the present invention is a carbon fiber woven fabric comprising a carbon fiber bundle of yarn and a carbon fiber bundle of weft. The weaving form is not particularly limited, and examples include plain weave, twill weave, and satin weave.

The attached reinforcing fibers th prepreg of the present invention, 50 to 800 g / ^{m 2} is preferred. When the reinforcing fiber basis weight of the prepreg is extremely low, it is necessary to laminate a large number of prepregs in order to obtain a desired thickness of the molded product, and the drapeability is also extremely increased and workability is deteriorated, but 50 g / m ² If it is above, the prepreg excellent in workability | operativity will be obtained. On the other hand, when the reinforcing fiber basis weight is extremely large, the rigidity of the prepreg is increased and it becomes difficult to obtain the drape property which is the effect of the present invention. However, if it is 800 g / m ² or less, sufficient drape property is obtained. It is done. A more preferable reinforcing fiber basis weight is 75 to 600 g / m ² , further preferably 100 to 450 g / m ² , and most preferably 125 to 400 g / m ² .

  The fiber volume content (Vf) of the prepreg of the present invention is 10 to 70 vol%. If Vf is 10 vol% or more, the mechanical properties of the molded article are excellent. Moreover, if Vf is 70 vol% or less, it is excellent in drape property and formability. More preferable Vf is 15-60 vol%, More preferably, it is 20-55 vol%, Most preferably, it is 25-50 vol%. In addition, since the Vf value measured based on JIS K7075 is a value that varies depending on the amount of voids in the prepreg base material, the fiber volume content does not depend on the amount of voids in the fiber reinforced plastic manufacturing method of the present invention. Adopt rate.

  Examples of the thermoplastic resin of the prepreg of the present invention include polyamide resins (nylon 6, nylon 66, nylon 12, nylon MXD6, etc.), polyolefin resins (low density polyethylene, high density polyethylene, polypropylene, etc.), modified polyolefin resins (modified polypropylene resin). Etc.), polyester resin (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate resin, polyamideimide resin, polyphenylene oxide resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyetherimide resin, polystyrene resin, ABS resin , Polyphenylene sulfide resin, liquid crystal polyester resin, copolymer of acrylonitrile and styrene, copolymer of nylon 6 and nylon 66, etc. It is possible. Examples of the modified polyolefin resin include a resin (acid-modified polypropylene resin) obtained by modifying a polyolefin resin with an acid such as maleic acid. A thermoplastic resin may be used individually by 1 type, may use 2 or more types together, and uses 2 or more types as a polymer alloy is very good. Among these, as the thermoplastic resin used for the prepreg of the present invention, a polycarbonate resin is preferable. More preferably, a polycarbonate resin containing at least a unit structure derived from a dihydroxy compound represented by the following formula (1) is preferable. The polycarbonate resin has excellent properties for impregnating carbon fiber bundles, and when impregnated in a carbon fiber fabric, has a characteristic that voids tend to collect between the carbon fiber bundles of the warp yarns and the carbon fiber bundles of the weft yarns, This is suitable for realizing the form of the prepreg of the present invention.

・・・式（１）

... Formula (1)

  In the polycarbonate resin including at least the unit structure derived from the dihydroxy compound represented by the above formula (1) of the present invention, the structural unit derived from the dihydroxy compound (1) with respect to the structural unit derived from all the dihydroxy compounds constituted The ratio is preferably 90 mol% or less, more preferably 85 mol% or less, and most preferably 80 mol% or less. On the other hand, it is preferably 20 mol% or more, more preferably 30 mol% or more, and most preferably 40 mol% or more.

  When the proportion of the structural unit derived from the dihydroxy compound (1) is too large, cracking may occur when the molded product is irradiated with sunshine carbon arc, and the transparency deteriorates and haze increases. There is. However, it is also possible to prevent this cracking by adding a light-resistant stabilizer described later, particularly a predetermined amount of a hindered amine light-resistant stabilizer. The details of the cause of the cracking are not clear, but if the proportion of the structural unit derived from the dihydroxy compound (1) is too large, the surface of the resulting molded product is deteriorated by ultraviolet irradiation and hydrolyzed, and the polycarbonate resin This is thought to be due to a decrease in molecular weight. However, as described above, it is possible to prevent the molded product from cracking by containing a light-resistant stabilizer. Although the details of this cause are not clear, it is considered that the light-resistant stabilizer suppresses ultraviolet irradiation deterioration and hydrolysis on the surface of the molded product, and the molecular weight of the resin is difficult to decrease.

  On the other hand, if the proportion of structural units derived from the dihydroxy compound (1) in the resin is too small, the heat resistance of the resulting molded product may be reduced.

  Examples of the dihydroxy compound represented by the general formula (1) include isosorbide, isomannide, and isoidet, which are in a stereoisomeric relationship, and these may be used alone or in combination of two or more. It may be used.

  The polycarbonate resin containing at least a unit structure derived from the dihydroxy compound represented by the formula (1) of the present invention may be referred to as a dihydroxy compound other than the dihydroxy compound (1) (hereinafter referred to as “other dihydroxy compound”). ) May be included.

  Specific examples of the dihydroxy compound other than the dihydroxy compound (1) include oxyalkylene glycols such as diethylene glycol, triethylene glycol, and tetraethylene glycol, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9 , 9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4 -(2-hydroxyethoxy) -3-isobutylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9,9-bis (4- (2- Hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9,9- (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3,5-dimethylphenyl) fluorene, 9,9-bis (4- Phenyl substituted fluorenes such as (2-hydroxyethoxy) -3-tert-butyl-6-methylphenyl) fluorene, 9,9-bis (4- (3-hydroxy-2,2-dimethylpropoxy) phenyl) fluorene, etc. Compounds having an aromatic group in the side chain and having an ether group bonded to the aromatic group in the main chain, compounds having a cyclic ether structure such as spiroglycol represented by the following general formula (3) (cyclic ether), etc. Is mentioned.

  Among these, diethylene glycol and triethylene glycol are preferable as dihydroxy compounds other than the dihydroxy compound (1) from the viewpoint of easy availability, handling, reactivity during polymerization, and hue of the resulting resin. A compound having a cyclic ether structure represented by formula (3) is preferred.

  These may be used alone or in combination of two or more depending on the required performance of the resin to be obtained.

・・・式（３）

... Formula (3)

  Of these dihydroxy compounds, it is preferable to use a dihydroxy compound having no aromatic ring structure from the viewpoint of the light resistance of the polycarbonate resin, and among them, it is abundant as a plant-derived resource and is produced from various easily available starches. Isosorbide obtained by dehydrating and condensing sorbitol is most preferable from the viewpoints of availability and production, light resistance, optical properties, moldability, heat resistance, and carbon neutral.

  Other specific examples of other dihydroxy compounds include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, and 1,2-butanediol. 1,5-heptanediol, 1,6-hexanediol and other aliphatic dihydroxy compounds, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecanedi Methanol, pentacyclopentadecane dimethanol, 2,6-decalin dimethanol, 1,5-decalin dimethanol, 2,3-decalin dimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, 1, Alicyclic dihydroxy such as 3-adamantane dimethanol Compound, 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A], 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-) 3,5-diethylphenyl) propane, 2,2-bis (4-hydroxy- (3,5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2, , 2-bis (4-hydroxyphenyl) pentane, 2,4′-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-5-nitrophenyl) methane, 1,1-bis (4 -Hydroxyphenyl) ethane, 3,3-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) cyclohexane Sun, bis (4-hydroxyphenyl) sulfone, 2,4′-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dichloro Diphenyl ether, 9,9-bis (4- (2-hydroxyethoxy-2-methyl) phenyl) fluorene, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-2-methyl) And aromatic bisphenols such as phenyl) fluorene. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Among these, from the viewpoint of the light resistance of the resin, a dihydroxy compound having no aromatic ring structure in the molecular structure, that is, an aliphatic dihydroxy compound and / or an alicyclic dihydroxy compound is preferable. As the aliphatic dihydroxy compound, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol are preferable. As the alicyclic dihydroxy compound, 1,4-cyclohexanedimethanol and tricyclodecane dimethanol are particularly preferable.

  By using these other dihydroxy compounds, it is possible to obtain effects such as improvement in flexibility and moldability of the resin, but if the content ratio of structural units derived from other dihydroxy compounds is too large The ratio of the structural unit derived from the dihydroxy compound (1) to the structural unit derived from all the dihydroxy compounds in the resin is greater than or equal to the above lower limit value because it may cause a decrease in mechanical properties and a decrease in heat resistance. It is preferable to use so that it becomes.

  Moreover, when using an alicyclic dihydroxy compound as another dihydroxy compound, the structural unit derived from the dihydroxy compound represented by the said General formula (1) in polycarbonate resin, and the structure derived from an alicyclic dihydroxy compound The ratio (mol%) to the unit is preferably in the range of 99: 1 to 30:70, and more preferably 90:10 to 40:60 from the viewpoint of mechanical properties and heat resistance.

  The dihydroxy compound (1) used for the synthesis of the resin contains stabilizers such as a reducing agent, an antioxidant, an oxygen scavenger, a light stabilizer, an antacid, a pH stabilizer, and a heat stabilizer. In particular, since the dihydroxy compound of the present invention is easily altered under acidic conditions, it is preferable to include a basic stabilizer.

  Basic stabilizers include hydroxides, carbonates, phosphates, phosphites, hypophosphites of group 1 or group 2 metals in the long-period periodic table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). , Borate, fatty acid salt, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, triethyl Methylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydro Basic ammonium compounds such as xoxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide, butyltriphenylammonium hydroxide, 4-amino Pyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole Amine compounds such as 2-mercaptoimidazole, 2-methylimidazole and aminoquinoline. Of these, sodium or potassium phosphates and phosphites are preferable, and disodium hydrogen phosphate and disodium hydrogen phosphite are particularly preferable because of their effects and ease of distillation removal described later.

  Although there is no restriction | limiting in particular in content in the dihydroxy compound (1) of these basic stabilizers, if too little, there exists a possibility that the effect which prevents the modification of dihydroxy compound (1) may not be acquired, and if too much, a dihydroxy compound Since the modification of (1) may be caused, it is usually 0.0001% by weight to 1% by weight, preferably 0.001% by weight to 0.1% by weight, based on the dihydroxy compound (1).

  When the dihydroxy compound (1) containing these basic stabilizers is used as a raw material for the production of polycarbonate resin, the basic stabilizer itself becomes a polymerization catalyst, which makes it difficult to control the polymerization rate and quality. It is preferable to remove the basic stabilizer by ion exchange resin, distillation or the like before using it as a raw material for producing polycarbonate resin in order to cause deterioration of hue and consequently deteriorate light resistance of the molded product.

  Since the dihydroxy compound (1) is apt to be gradually oxidized by oxygen, during storage and production, in order to prevent decomposition by oxygen, water should not be mixed in, and an oxygen scavenger or the like may be used, or in a nitrogen atmosphere. It is important to handle. For example, when isosorbide is oxidized, decomposition products such as formic acid may be generated. For this reason, when isosorbide containing these decomposition products is used as a raw material for the production of polycarbonate resin, there is a possibility that the resulting polycarbonate resin and further the polycarbonate resin composition may be colored, and the physical properties may be significantly deteriorated. In addition, it may affect the polymerization reaction, and a high molecular weight polymer may not be obtained.

  In order to obtain the dihydroxy compound (1) which does not contain the above oxidative decomposition product, and in order to remove the above basic stabilizer, it is preferable to carry out distillation purification. The distillation in this case may be simple distillation or continuous distillation, and is not particularly limited. As distillation conditions, it is preferable to carry out distillation under reduced pressure in an inert gas atmosphere such as argon or nitrogen. In order to suppress thermal denaturation, it is 250 ° C. or lower, preferably 200 ° C. or lower, particularly 180 °. It is preferable to carry out under the conditions of ℃ or less.

  By such distillation purification, the content of decomposition products such as formic acid in the dihydroxy compound (1) is adjusted to 20 ppm by weight or less, preferably 10 ppm by weight or less, particularly preferably 5 ppm by weight or less. When the dihydroxy compound containing 1) is used as a polycarbonate resin production raw material, a polycarbonate resin excellent in hue and thermal stability can be produced without impairing polymerization reactivity. The content of decomposition products such as formic acid is measured by ion chromatography.

  The polycarbonate resin containing at least the unit structure derived from the dihydroxy compound represented by the above formula (1) used in the present invention is obtained by the transesterification reaction using the dihydroxy compound containing the dihydroxy compound (1) and the carbonic acid diester as raw materials. It can be obtained by condensation.

  Examples of the carbonic acid diester used for the reaction include those represented by the following general formula (4). These carbonic acid diesters may be used alone or in combination of two or more.

・・・式（４）

... Formula (4)

In General Formula (4), A ¹ and A ² are each a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms or a substituted or unsubstituted aromatic group, and A ¹ and A ² are They may be the same or different.

  Examples of the carbonic acid diester represented by the general formula (4) (hereinafter sometimes referred to as “carbonic acid diester (3)”) include substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate, dimethyl carbonate, and diethyl carbonate. And di-t-butyl carbonate and the like are exemplified, but diphenyl carbonate and substituted diphenyl carbonate are preferred, and diphenyl carbonate is particularly preferred.

  In addition, the carbonic acid diester may contain impurities such as chloride ions, and these impurities may inhibit the polymerization reaction or worsen the hue of the resulting polycarbonate resin. It is preferable to use one purified by distillation or the like.

  The polycarbonate resin used in the present invention is produced by transesterification of the dihydroxy compound containing the dihydroxy compound (1) and the carbonic acid diester (3) as described above. More specifically, it can be obtained by transesterification and removing by-product monohydroxy compounds and the like out of the system. In this case, polycondensation is usually carried out by transesterification in the presence of a transesterification catalyst.

  The transesterification reaction catalyst (hereinafter simply referred to as “catalyst” or “polymerization catalyst”) that can be used in the production of the polycarbonate resin used in the present invention is a light transmittance at a wavelength of 350 nm of the obtained polycarbonate resin composition. In addition, the yellow index (YI) value may be affected.

  As the catalyst used, any of the light resistance, transparency, hue, heat resistance, thermal stability, moldability, and mechanical strength of the manufactured polycarbonate resin composition can satisfy the light resistance. Although not limited, metal compounds, basic boron compounds, basic phosphorus compounds, basic compounds of Group 1 or Group 2 (hereinafter simply referred to as “Group 1” or “Group 2”) in the long-period periodic table 1 type, or 2 or more types of basic compounds, such as an ammonium compound and an amine compound, are mentioned. Preferably, Group 1 metal compounds and / or Group 2 metal compounds are used.

  It is also possible to use a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, and an amine compound in combination with the above-mentioned Group 1 metal compound and / or Group 2 metal compound. However, it is particularly preferable to use only Group 1 metal compounds and / or Group 2 metal compounds.

  The group 1 metal compound and / or group 2 metal compound is usually used in the form of a salt such as a hydroxide or carbonate, carboxylate, or phenol salt. From the viewpoint of ease of handling, hydroxides, carbonates and acetates are preferable, and acetates are preferable from the viewpoint of hue and polymerization activity.

  Examples of the group 1 metal compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate, and carbonic acid. Lithium, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, hydrogenated Cesium boron, sodium phenide boron, potassium phenide boron, lithium phenide boron, cesium phenide boron, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, hydrogen phosphate 2 Thorium, 2 potassium hydrogen phosphate, 2 lithium hydrogen phosphate, 2 cesium hydrogen phosphate, 2 sodium phenyl phosphate, 2 potassium phenyl phosphate, 2 lithium phenyl phosphate, 2 cesium phenyl phosphate, sodium, potassium, lithium, Examples include cesium alcoholate, phenolate, disodium salt of bisphenol A, 2 potassium salt, 2 lithium salt, 2 cesium salt, etc. Among them, lithium compounds are preferable.

  Examples of the Group 2 metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, carbonic acid. Magnesium, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, etc. Among them, magnesium compound, calcium compound, barium compound are preferable, polymerization activity From the viewpoint of the hue of the polycarbonate resin composition obtained, a magnesium compound and / or a calcium compound is more preferable, and most preferably a calcium compound. It is.

  Examples of the basic boron compound include tetramethyl boron, tetraethyl boron, tetrapropyl boron, tetrabutyl boron, trimethylethyl boron, trimethylbenzyl boron, trimethylphenyl boron, triethylmethyl boron, triethylbenzyl boron, triethylphenyl boron, Sodium salt such as tributylbenzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, butyltriphenylboron, sodium salt, potassium salt, lithium salt, calcium salt, barium salt, magnesium salt, strontium salt, etc. Is mentioned.

  Examples of the basic phosphorus compound include triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and quaternary phosphonium salts.

  Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide. Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium Dorokishido, butyl triphenyl ammonium hydroxide, and the like.

  Examples of the amine compound include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, and 4-methoxypyridine. , 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like.

  The amount of the polymerization catalyst used is usually 0.1 μmol to 300 μmol, preferably 0.5 μmol to 100 μmol per 1 mol of all dihydroxy compounds used in the polymerization, and at least one selected from the group consisting of lithium and group 2 among them. When using a compound containing any of these metals, particularly when using a magnesium compound and / or a calcium compound, the metal amount is usually 0.1 μmol or more, preferably 0.5 μmol or more, particularly preferably, per 1 mol of the total dihydroxy compound. Is 0.7 μmol or more. Further, the upper limit is usually 20 μmol, preferably 10 μmol, more preferably 3 μmol, particularly preferably 1.5 μmol, and most preferably 1.0 μmol.

  If the amount of the catalyst is too small, the polymerization rate is slowed down. As a result, when trying to obtain a polycarbonate resin having a desired molecular weight, the polymerization temperature has to be increased, and the hue and light resistance of the obtained polycarbonate resin are deteriorated. Or the unreacted raw material volatilizes during the polymerization, and the molar ratio of the dihydroxy compound containing the dihydroxy compound (1) of the present invention to the carbonic acid diester (3) may collapse, and the desired molecular weight may not be reached. On the other hand, when there is too much usage-amount of a polymerization catalyst, the hue of the polycarbonate resin obtained will be deteriorated and the light resistance of a polycarbonate resin may deteriorate.

  Furthermore, when the polycarbonate resin used in the present invention is produced using a substituted diphenyl carbonate such as diphenyl carbonate or ditolyl carbonate as the carbonic acid diester (3), phenol and substituted phenol are by-produced in the polycarbonate resin. Residual and contained in the polycarbonate resin composition is unavoidable, but the remaining phenol and substituted phenol also has an aromatic ring, so it not only absorbs ultraviolet rays but may cause deterioration of light resistance. , It may cause odor during molding.

  The polycarbonate resin contains an aromatic monohydroxy compound having an aromatic ring such as by-product phenol of 1000 ppm by weight or more after a normal batch reaction, but from the viewpoint of light resistance and odor reduction, it is devolatilized. Using a horizontal reactor with excellent performance and an extruder with a vacuum vent, these are devolatilized and removed, and the content of the aromatic monohydroxy compound in the polycarbonate resin is 700 ppm by weight or less, preferably 500 ppm by weight or less. In particular, the content is preferably 300 ppm by weight or less. However, it is difficult to industrially completely remove the aromatic monohydroxy compound in the polycarbonate resin, and the lower limit of the content of the aromatic monohydroxy compound in the polycarbonate resin is usually 1 ppm by weight.

  These aromatic monohydroxy compounds may naturally have a substituent depending on the raw material used, and may have, for example, an alkyl group having 5 or less carbon atoms.

  Further, Group 1 metals, especially lithium, sodium, potassium, and cesium, especially sodium, potassium, and cesium, may adversely affect the hue when contained in a large amount in the polycarbonate resin, but the metal is a catalyst used. The total amount of these metals in the polycarbonate resin is usually not more than 1 ppm by weight, preferably not more than 0.8 ppm by weight, more preferably because it may be mixed not only from the raw materials but also from raw materials and reactors. Of 0.7 ppm by weight or less.

  The amount of metal in the polycarbonate resin can be measured using a method such as atomic emission, atomic absorption, Inductively Coupled Plasma (ICP) after recovering the metal in the polycarbonate resin by a method such as wet ashing. .

  The glass transition temperature (Tg) of the polycarbonate resin is preferably less than 145 ° C, and preferably less than 130 ° C. When the temperature is higher than 145 ° C., the impregnation of the resin into the carbon fiber is insufficient and sufficient fluidity cannot be obtained. On the other hand, the lower limit of the glass transition temperature is preferably 80 ° C. or higher, and preferably 100 ° C. or higher. If it is lower than 80 ° C., sufficient mechanical properties at high temperatures cannot be obtained.

  The glass transition temperature (Tg) of the matrix resin can be adjusted by appropriately selecting the dihydroxy compound to be used and the carbonic acid diester.

  The prepreg of the present invention preferably has a drape value of 1.0 to 5.0 cm. When the drape value is small, the prepreg is rigid and the shape following ability is poor at the time of preforming, and it becomes difficult to mold into a complicated shape. Further, when the drape value is large, the prepreg is not stiff and the workability of the prepreg lamination work is lowered. However, if it is the said range, shape followability and workability | operativity can be made compatible. A more preferable drape value is 1.2 to 4.8 cm, still more preferably 1.5 to 4.5 cm, and most preferably 1.8 to 4.0 cm.

The drape value in the present invention is a value obtained by the following method.
First, a prepreg cut to a size of 6 mm length × 350 mm length is placed on the upper surface of a horizontal test stand, and a 300 mm portion is projected into the air from the tip in the length direction of the prepreg. On the remaining 50 mm portion, an aluminum plate is placed and a weight of about 100 g is placed and fixed so as not to move during measurement. After holding the prepreg so as to be horizontal, 30 seconds after the holding and dropping, the distance from the test table horizontal surface at the tip in the length direction of the prepreg is taken as the drape value.

  The carbon fiber composite material plate of the present invention can be obtained by laminating and integrating the prepreg of the present invention. The carbon fiber composite material plate of the present invention can be produced by a known method. Examples include press molding and autoclave molding.

In the carbon fiber composite material plate of the present invention, the fiber volume content Vf of the raw fiber composite material plate and the three-point bending strength σ (MPa) measured according to JIS K7074 preferably satisfy the following formula (2). .
400 (MPa) ≦ 42 × σ ÷ Vf ≦ 1200 (MPa) (2)

  If the value of the formula (2) is 400 MPa or more, the composite material obtained when the prepreg is molded exhibits excellent mechanical properties. In the present invention, an adverse effect caused by the value of the expression (2) being too high has not been clarified, but it is considered that the effect of the present invention is manifested at 1200 MPa or less. Further, the value of the formula (2) is 450 to 1200 MPa, more preferably 500 to 1200 MPa, and most preferably 550 to 1200 MPa.

[Example 1]
Polycarbonate comprising at least a unit structure derived from a dihydroxy compound represented by the above formula (1) of the present invention, a carbon fiber fabric (Pyrofil fabric manufactured by Mitsubishi Chemical Co., Ltd., product number: TR6110M, plain weave, fiber basis weight: 288 g / m ² ). The carbon fiber fabric is sandwiched from both sides by a film having a basis weight of 109 g / m2 made of resin (Mitsubishi Chemical Durabio, product number: D7340R, specific gravity 1.36), and sandwiched between metal flat plates with a release treatment on the surface. The carbon fiber fabric was impregnated with a polycarbonate resin containing at least a unit structure derived from the dihydroxy compound represented by the above formula (1) of the present invention under the conditions of 270 ° C., 7 minutes, and 0.2 MPa with a heating press. While maintaining the press pressure, the mixture was cooled to room temperature to obtain a prepreg having a fiber content of 49% by volume. The prepreg drape value was 2.5 cm.

  The obtained prepreg was cut into 3 cm square and embedded in Epomount 27-770 manufactured by Refine Tech. After the Epomount 27-770 was cured, it was polished and mirror-finished so that the cross section of the sample piece was exposed. A cross-sectional photograph of the prepreg was taken using a microscope VHX-5000 manufactured by Keyence Corporation. From the photographed images, the thickness of the gap in the perpendicular direction between the carbon fiber bundle of the carbon fiber fabric that is the reinforcing fiber of the prepreg and the carbon fiber bundle of the weft, and the carbon fiber bundle and the weft of the warp with respect to all the gaps in the prepreg The ratio of voids existing between the carbon fiber bundles was calculated. The thickness of the gap between the carbon fiber bundle of the warp and the carbon fiber bundle of the weft is 30 μm, and the ratio of the gap between the carbon fiber bundle of the warp and the carbon fiber bundle of the weft is 96% with respect to all the gaps in the prepreg. Met.

  Further, the obtained prepreg was cut into a size of 120 mm × 200 mm, and seven prepregs were laminated in the same direction to produce a prepreg laminate. The prepreg laminate is placed in a stamping die having a size of 120 mm × 200 mm and a depth of 15 mm, and a board surface at 250 ° C. using a multi-stage press (compression molding machine manufactured by Shindo Metal Industries, product name: SFA-50HH0). Was heated and pressurized at a pressure of 0.1 MPa for 2 minutes. Thereafter, the laminate was cooled to room temperature with the same pressure to obtain a plate-like carbon fiber composite material plate having a thickness of 2.2 mm.

  From the obtained carbon fiber composite material plate, a bending test piece having a length of 120 mm and a width of 12.7 mm was cut out by a wet cutter, and a bending strength σ was measured by performing a three-point bending test according to a test method specified in JIS K7074. . The bending strength σ was 890 MPa, and the value of 42 × σ ÷ Vf (49) was 690 MPa.

[Comparative Example 1]
Instead of a polycarbonate resin containing at least a unit structure derived from the dihydroxy compound represented by the above formula (1) of the present invention, a PMMA resin (Mitsubishi Chemical's Dianal, product number: RB-2687, specific gravity 1.20) is used. A prepreg is obtained in the same manner as in Example 1 except that it is used. The prepreg obtained has a drape value of 0.9 cm.

  When a cross-sectional photograph was taken in the same manner as in Example 1, the thickness of the void in the perpendicular direction between the carbon fiber bundle of the warp and the carbon fiber bundle of the weft was 0 μm, and the carbon fiber bundle of the warp with respect to all the voids in the prepreg The proportion of voids present between the weft carbon fiber bundles is 0%.

  After obtaining a carbon fiber composite material from the obtained prepreg in the same manner as in Example 1, the bending strength σ is measured in the same manner as in Example 1. The bending strength σ is 460 MPa, and the value of 42 × σ ÷ Vf (49) is 392 MPa.

Claims (9)

  A carbon fiber fabric comprising a carbon fiber bundle of warp and a carbon fiber bundle of weft and a thermoplastic resin, wherein the carbon fiber bundle has an impregnation rate of 85% or more, and the carbon fiber of the warp A prepreg having a portion in which a bundle and a carbon fiber bundle of the weft overlap, and having an air gap without the thermoplastic resin in the overlapping portion.   The prepreg according to claim 1, wherein a height of the gap in a direction perpendicular to the plane of the prepreg is 10 to 100 μm.   The prepreg according to claim 1 or 2, wherein 80% or more of all voids in the prepreg are present between the carbon fiber bundle of the yarn and the carbon fiber bundle of the weft.   The prepreg according to any one of claims 1 to 3, wherein the thermoplastic resin is a polycarbonate resin. The prepreg of Claim 4 in which the said polycarbonate resin contains the unit structure derived from the compound represented by following formula (1).

... Formula (1) The basis weight of the carbon fiber woven fabric is 200~650g / ^{m 2,} the prepreg according to any one of claims 1 to 5. The prepreg according to any one of claims 1 to 6, wherein the prepreg has a drape value of 1 to 5 cm.   A carbon fiber composite material plate formed by laminating and integrating the prepreg according to claim 1. The composite material plate according to claim 8, wherein a three-point bending strength σ (MPa) measured in accordance with fiber volume content Vf and JIS K7074 of the carbon fiber composite material plate satisfies the following formula (2).
400 (MPa) ≦ 42 × σ ÷ Vf ≦ 1200 (MPa)
... Formula (2)