JP2023056224A - Fiber-reinforced resin substrate - Google Patents

Abstract

To provide a fiber-reinforced resin substrate that has excellent mechanical property.SOLUTION: Provided is a fiber-reinforced thermoplastic resin substrate, which is a fiber-reinforced thermoplastic resin substrate obtained by impregnating a plurality of continuous reinforcing fibers with a polyphenylene sulfide resin composition, and in which the polyphenylene sulfide resin composition has a radical generation amount of 3.0×1016/g or more and 3.5×1016/g or less as measured by the electron spin resonance method with a predetermined condition.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a fiber-reinforced resin base material.

A fiber-reinforced resin base material in which a plurality of continuous reinforcing fibers are impregnated with a thermoplastic resin is not only superior in its lightweight effect, but also has better toughness, welding workability and recycling than a fiber-reinforced resin base material using a thermosetting resin. Due to its excellent durability, it is widely used in transportation equipment such as aircraft and automobiles, as well as various applications such as sports, electrical and electronic parts. In recent years, in addition to mechanical strength and weight reduction, which were the added values of conventional CFRTP (carbon fiber reinforced thermoplastic resin) intermediate substrates, high added values such as high heat resistance, low water absorption, high toughness and moldability are also required. As a result, there is a strong demand for technical development of high-performance CFRTP intermediate substrates, mainly for aircraft and automobile applications.

Polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) resin is a crystalline thermoplastic resin having excellent heat resistance and chemical resistance, and is also attracting attention as a matrix resin for composite materials. However, conventional PPS resins are inherently brittle materials with low toughness. In the case of fibers such as carbon fibers, which hardly expand when heated, residual stress during molding is large and slight disturbance in the arrangement of fibers can cause The molded product often bends or cracks occur, resulting in insufficient composite physical properties such as bending strength and interlaminar shear strength.

Patent Document 1 discloses a method for producing a carbon fiber reinforced PPS base material with excellent mechanical properties by impregnating uncrosslinked PPS resin, heating at 300 to 360° C. for a specific period of time, and subjecting it to thermal cross-linking treatment. It is

Further, Patent Document 2 discloses a method for producing a carbon fiber-reinforced PPS base material having excellent mechanical properties by using a PPS resin oxidatively crosslinked in the atmosphere.

Furthermore, Patent Document 3 discloses a method for producing a carbon fiber reinforced PPS base material with excellent mechanical properties by using a resin composition of a PPS resin oxidatively crosslinked in the air and a high-molecular-weight PPS resin. there is

Furthermore, Patent Document 4 discloses a method for producing a short carbon fiber-reinforced PPS base material having excellent mechanical properties by using a resin composition of a high-molecular-weight PPS resin.

Japanese Patent No. 1477262 JP-A-2-180934 JP-A-3-292335 JP-A-9-25346

In the method proposed in Patent Document 1, a carbon fiber reinforced PPS base material having excellent mechanical properties can be obtained, but there is no specific disclosure of the amount of radicals generated in the PPS resin and the content of carboxylic acid. rice field.

In Patent Document 2, a carbon fiber reinforced PPS base material having excellent mechanical properties can be obtained by using a PPS resin that has been oxidatively crosslinked in the atmosphere. There was a problem that the stability of the process and the mechanical properties of the molded product deteriorated. Further, no specific disclosure was made regarding the amount of radicals generated by the PPS resin and the content of the carboxylic acid.

In Patent Document 3, a carbon fiber reinforced PPS base material with excellent mechanical properties is obtained by using a resin composition of a PPS resin oxidatively crosslinked in the atmosphere and a high-molecular-weight PPS resin, but the manufacturing process is complicated. In addition, there is a problem that a gelled product tends to be generated in the PPS resin, and the stability of the manufacturing process and the mechanical properties of the molded product are deteriorated.

Patent Document 4 discloses that a short carbon fiber reinforced PPS base material having excellent mechanical properties can be obtained by using a resin composition of a high molecular weight PPS resin. A fiber reinforced PPS substrate has been desired. In addition, there was no specific disclosure of the amount of radicals generated by the PPS resin or the content of carboxylic acid.

Thus, the mechanical properties of fiber-reinforced PPS substrates have not been sufficient with conventional techniques. The present invention provides a fiber-reinforced PPS resin composition base material with excellent mechanical properties and a method for producing the same.

[1] A fiber-reinforced thermoplastic resin substrate obtained by impregnating a plurality of continuous reinforcing fibers with a polyphenylene sulfide resin composition, wherein the polyphenylene sulfide resin composition generates radicals measured by the following electron spin resonance method A fiber-reinforced thermoplastic resin base material having an amount of 3.0×10 ¹⁶ pieces/g or more and 3.5×10 ¹⁶ pieces/g or less.
(Measurement condition)
The amount of radicals generated when the temperature is raised from room temperature to 350° C. at a temperature elevation rate of 20° C./min and held for 30 minutes after reaching 350° C. [2] The polyphenylene sulfide resin composition is (A) a polyphenylene sulfide resin and (B) The fiber-reinforced resin base material according to [1], which comprises a bisphenol derivative.
[3] (A) is 99.6 to 99.9% by weight and (B) is 0.4 to 0.1% by weight, where the total of (A) and (B) is 100% by weight; [1] Or the fiber-reinforced thermoplastic resin substrate according to [2].
[4] The fiber-reinforced thermoplastic resin substrate according to any one of [1] to [3], wherein the polyphenylene sulfide resin (A) has a carboxyl group content of 5 to 250 μmol/g.
[5] The fiber-reinforced thermoplastic resin base material according to any one of [1] to [4], wherein the fiber volume content of the fiber-reinforced resin base material is 20 to 65% by volume.

According to the present invention, the adhesion between the PPS resin composition and the reinforcing fibers is excellent, so that a fiber-reinforced base material having excellent mechanical properties can be obtained.

Hereinafter, embodiments of the present invention will be described in detail.

<Reinforcing fiber>
The type of reinforcing fiber is not particularly limited, and examples thereof include carbon fiber, metal fiber, organic fiber, and inorganic fiber. You may use 2 or more types of these. By using carbon fiber as the reinforcing fiber, it is possible to obtain a fiber-reinforced polyphenylene sulfide base material that is lightweight and has high mechanical properties.

Examples of carbon fibers include PAN-based carbon fibers made from polyacrylonitrile (PAN) fibers, pitch-based carbon fibers made from petroleum tar or petroleum pitch, and cellulose-based carbon made from viscose rayon, cellulose acetate, or the like. fibers, vapor-grown carbon fibers made from hydrocarbons, and graphitized fibers thereof; Among these carbon fibers, PAN-based carbon fibers are preferably used because they have an excellent balance between strength and elastic modulus.

Examples of metal fibers include fibers made of metals such as iron, gold, silver, copper, aluminum, brass, and stainless steel.

Examples of organic fibers include fibers made of organic materials such as aramid, polybenzoxazole (PBO), polyphenylene sulfide, polyester, polyamide, and polyethylene. Examples of aramid fibers include para-aramid fibers that are excellent in strength and elastic modulus, and meta-aramid fibers that are excellent in flame retardancy and long-term heat resistance. Examples of para-aramid fibers include polyparaphenylene terephthalamide fibers and copolyparaphenylene-3,4′-oxydiphenylene terephthalamide fibers. Examples of meta-aramid fibers include polymetaphenylene isophthalamide fibers. is mentioned. As the aramid fibers, para-aramid fibers having a higher elastic modulus than meta-aramid fibers are preferably used.

Examples of inorganic fibers include fibers made of inorganic materials such as glass, basalt, silicon carbide, and silicon nitride. Glass fibers include, for example, E glass fiber (for electrical use), C glass fiber (for corrosion resistance), S glass fiber, and T glass fiber (high strength and high modulus of elasticity). Basalt fiber is a fibrous material made from mineral basalt, and is a fiber with extremely high heat resistance. Basalt generally contains 9-25% by weight of iron compounds FeO or FeO ₂ and 1-6% by weight of titanium compounds TiO or TiO _{2 ;} It is also possible to make fibers by

Since the fiber-reinforced resin base material in the present invention is often expected to serve as a reinforcing material, it is desirable to exhibit high mechanical properties. preferably included.

In the fiber-reinforced resin base material of the present invention, the reinforcing fibers are usually configured by arranging one or more reinforcing fiber bundles in which a large number of single fibers are bundled. The total number of reinforcing fiber filaments (number of single fibers) when one or more reinforcing fiber bundles are arranged is preferably 1,000 to 2,000,000. From the viewpoint of productivity, the total number of filaments of the reinforcing fibers is more preferably 1,000 to 1,000,000, still more preferably 1,000 to 600,000, and 1,000 to 300,000. Especially preferred. The upper limit of the total number of filaments of the reinforcing fibers should be such that good productivity, dispersibility, and handleability can be maintained in consideration of the balance between dispersibility and handleability.

A single reinforcing fiber bundle of the present invention is preferably configured by bundling 1,000 to 50,000 reinforcing fiber monofilaments having an average diameter of 5 to 10 μm.

The fiber-reinforced resin substrate in the present invention is characterized in that the thermoplastic resin impregnated into the plurality of continuous reinforcing fibers is a polyphenylene sulfide resin composition described later.

The continuous reinforcing fiber in the present invention refers to a fiber-reinforced resin substrate in which the reinforcing fiber is continuous. Examples of the form and arrangement of the reinforcing fibers in the embodiment of the present invention include unidirectionally aligned, woven fabric (cloth), knitted fabric, braided cord, tow, and the like. Among them, it is preferable that the reinforcing fibers are arranged in one direction because the mechanical properties in a specific direction can be efficiently improved.

<Polyphenylene sulfide resin composition>
The polyphenylene sulfide resin composition in the present invention is a polyphenylene sulfide resin composition having a radical generation amount of 3.0×10 ¹⁶ or more/g and 3.5×10 ¹⁶ or less/g under the measurement conditions described later. Point. Further, preferably, the polyphenylene sulfide resin composition comprises (A) a polyphenylene sulfide resin and (B) a bisphenol derivative, and the total content of (A) the polyphenylene sulfide resin is 99.6 to 99.9% when the total is 100% by weight. % by weight, and (B) the bisphenol derivative is 0.4 to 0.1% by weight.

The amount of radicals generated in the polyphenylene sulfide resin composition used in the present invention is 3.0×10 ¹⁶ /g or more and 3.5×10 ¹⁶ /g or less. Preferably, the radical generation amount is 3.2×10 ¹⁶ /g or more and 3.4×10 ¹⁶ /g or less. The lower limit of the radical generation amount of the polyphenylene sulfide resin composition is 3.0×10 ¹⁶ /g or more, preferably 3.1×10 ¹⁶ /g or more, more preferably 3.2×10 ¹⁶ . /g or more. The upper limit of the radical generation amount of the polyphenylene sulfide resin composition is 3.5×10 ¹⁶ /g or less, preferably 3.4×10 ¹⁶ /g or less. When the radical generation amount of the polyphenylene sulfide resin composition is within the above preferred range, a fiber-reinforced base material having better mechanical properties tends to be obtained. The reason for this is not clear at this time, but when the amount of radicals generated in the polyphenylene sulfide resin composition is appropriate, a radical reaction causes bonding between the reinforcing fibers and the polyphenylene sulfide resin composition, and the interfacial strength between the reinforcing fibers increases. It is presumed that a fiber-reinforced base material having improved mechanical properties was obtained. If the amount of radicals generated from the polyphenylene sulfide resin composition is less than 3.0×10 ¹⁶ /g, the adhesion between the polyphenylene sulfide resin composition and the reinforcing fibers tends to decrease. On the other hand, when the amount of radicals generated from the polyphenylene sulfide resin composition is greater than 3.5×10 ¹⁶ /g, the melt viscosity is remarkably increased due to the cross-linking reaction of the polyphenylene sulfide resin composition during the preparation of the fiber-reinforced base material. , the impregnability with the reinforcing fibers is lowered, and there is a tendency that a fiber-reinforced base material impregnated with the polyphenylene sulfide resin composition is not obtained satisfactorily. Alternatively, the polyphenylene sulfide resin composition tends to decompose and the mechanical properties tend to deteriorate.

Here, the radical generation amount is calculated by an electron spin resonance method using EMXplus (manufactured by BRUKER). Specifically, the temperature was raised from room temperature to 350°C at a temperature elevation rate of 20°C/min, and the amount of radicals generated when the temperature was maintained for 30 minutes after reaching 350°C was measured using a Mn marker (Mn ²⁺ in MgO) at the same time. It is calculated by measurement.

Moreover, it is preferable that the polyphenylene sulfide resin composition comprises (A) a polyphenylene sulfide resin and (B) a bisphenol derivative. Although the reason why the (B) bisphenol derivative is effective is not clear at the present time, the (B) bisphenol derivative does not affect the radical generation amount of the polyphenylene sulfide resin composition comprising (A) the polyphenylene sulfide resin and (B) the bisphenol derivative. It is presumed that a radical reaction between the reinforcing fiber and the polyphenylene sulfide resin composition caused bonding, improving the interfacial strength with the reinforcing fiber, and obtaining a fiber-reinforced base material with mechanical properties. be.

The mixing ratio of (A) polyphenylene sulfide resin and (B) bisphenol derivative in the present invention is in the range of (A)/(B) = 99.9 to 99.6% by weight/0.1 to 0.4% by weight. more preferably (A)/(B)=99.9 to 99.8% by weight/0.1 to 0.2% by weight.

When the blending ratio of (A) the polyphenylene sulfide resin and (B) the bisphenol derivative is within the above preferred range, there is a tendency to obtain a fiber-reinforced base material with better mechanical properties. Although the reason for this is not clear at this time, the amount of radicals generated in the polyphenylene sulfide resin composition becomes appropriate, and bonding occurs between the reinforcing fibers and the polyphenylene sulfide resin composition due to a radical reaction, thereby improving the interfacial strength between the reinforcing fibers. , it is presumed that a fiber-reinforced base material having mechanical properties was obtained. If the amount of the bisphenol derivative (B) added to the polyphenylene sulfide resin composition is less than 0.1% by weight, the adhesion between the polyphenylene sulfide resin composition and the reinforcing fibers tends to decrease. On the other hand, when the amount of the bisphenol derivative (B) added to the polyphenylene sulfide resin composition is more than 0.4% by weight, the melt viscosity is remarkably increased due to the cross-linking reaction of the polyphenylene sulfide resin composition during the preparation of the fiber-reinforced base material. Therefore, there is a tendency that the impregnability with the reinforcing fibers is lowered, and a fiber-reinforced base material impregnated with the polyphenylene sulfide resin composition is not obtained. Alternatively, the bisphenol derivative tends to decompose during the preparation of the fiber-reinforced base material, forming voids and degrading the mechanical properties.

The polyphenylene sulfide resin composition with which the reinforcing fiber bundles are impregnated in the present invention is obtained by melt-kneading. The melt-kneader is supplied to a known melt-kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, and a mixing roll, and kneaded at a processing temperature of the melting peak temperature of the resin composition + 5 to 100 ° C. A typical example is a method of In this case, there are no particular restrictions on the order in which the raw materials are mixed, and all the raw materials are mixed and then melt-kneaded by the above method. Either a method of melt-kneading, or a method of blending a part of the raw materials and then mixing the rest of the raw materials using a side feeder during melt-kneading with a single-screw or twin-screw extruder may be used. As for the small amount of the additive component, it is of course possible to knead the other components by the above-described method, pelletize the pelletized product, and then add the pelletized product before molding.

<Polyphenylene sulfide resin>
Polyphenylene sulfide resin (PPS resin) used in the present invention is a polymer having a repeating unit represented by the following structural formula,

From the viewpoint of heat resistance, a polymer containing 70 mol % or more, more preferably 90 mol % or more of a polymer containing a repeating unit represented by the above structural formula is preferred. In addition, about less than 30 mol % of the repeating units of the polyphenylene sulfide resin may be composed of repeating units having the following structure.

Since a polyphenylene sulfide copolymer partially having such a structure has a low melting point, such a resin composition is advantageous in moldability.
Description of Viscosity Changed Although the melt viscosity of the polyphenylene sulfide resin (A) used in the present invention is not particularly limited, a higher melt viscosity is preferable in order to obtain better toughness. For example, the range exceeding 100 Pa·s is preferable, 150 Pa·s or more is more preferable, and 200 Pa·s or more is even more preferable. The upper limit is preferably 600 Pa·s or less from the viewpoint of maintaining melt fluidity.

Here, the melt viscosity was measured using Capilograph 1C manufactured by Toyo Seiki Co., Ltd., using a die with a hole length of 10.00 mm and a hole diameter of 0.50 mm. About 20 g of a sample was placed in a cylinder set at 300° C., held for 5 minutes, and then the melt viscosity was measured at a shear rate of 1216 sec −1 .

The (A) polyphenylene sulfide resin used in the present invention preferably has a carboxyl group content of 5 to 250 μmol/g from the viewpoint of improving adhesion to reinforcing fibers. The lower limit of the carboxyl group content is preferably 5 µmol/g or more, more preferably 8 µmol/g or more, and even more preferably 10 µmol/g. The upper limit of the carboxyl group content is preferably 250 µmol/g or less, more preferably 200 µmol/g or less. If the carboxyl group content of the polyphenylene sulfide resin is less than 5 μmol/g, the interaction with the reinforcing fibers and adhesion tend to decrease, which is not preferable. On the other hand, when the carboxyl group content of the polyphenylene sulfide resin exceeds 250 μmol/g, the volatile content in the processing step increases, which is not preferable. The carboxyl group content of the polyphenylene sulfide resin is a value calculated using a Fourier transform infrared spectrometer (FT-IR).

Methods for introducing carboxyl groups into polyphenylene sulfide resin include a method of copolymerizing a polyhalogenated aromatic compound containing a carboxyl group, and a method of adding a compound containing a carboxyl group, such as maleic anhydride or sorbic acid. , a method of introducing by reacting with a polyphenylene sulfide resin while being melt-kneaded, and the like.

The method for producing the polyphenylene sulfide resin used in the present invention will be described below, but the method is not limited to the following method as long as the polyphenylene sulfide resin having the above structure can be obtained.

First, the contents of the polyhalogen aromatic compound, the sulfidating agent, the polymerization solvent, the molecular weight modifier, the polymerization aid and the polymerization stabilizer used in the production method will be described.

[Polyhalogenated Aromatic Compound]
A polyhalogenated aromatic compound is a compound having two or more halogen atoms in one molecule. Specific examples include p-dichlorobenzene, m-dichlorobenzene, o-dichlorobenzene, 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, hexa Polyhalogenated aromatics such as chlorobenzene, 2,5-dichlorotoluene, 2,5-dichloro-p-xylene, 1,4-dibromobenzene, 1,4-diiodobenzene, 1-methoxy-2,5-dichlorobenzene group compounds, preferably p-dichlorobenzene is used. In addition, for the purpose of introducing a carboxyl group, carboxyl group-containing dihalogenated aromatics such as 2,4-dichlorobenzoic acid, 2,5-dichlorobenzoic acid, 2,6-dichlorobenzoic acid, and 3,5-dichlorobenzoic acid It is also one of preferred embodiments to use compounds and mixtures thereof as copolymerizable monomers. It is also possible to combine two or more different polyhalogenated aromatic compounds to form a copolymer, It is preferable to use p-dihalogenated aromatic compound as a main component.

The amount of the polyhalogenated aromatic compound used is 0.9 to 2.0 mol, preferably 0.95 to 1.5 mol, per 1 mol of the sulfidating agent, from the viewpoint of obtaining a polyphenylene sulfide resin having a viscosity suitable for processing. and more preferably 1.005 to 1.2 mol.

[Sulfidation agent]
Sulfidating agents include alkali metal sulfides, alkali metal hydrosulfides, and hydrogen sulfide.

Specific examples of alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more of these, with sodium sulfide being preferred. These alkali metal sulfides can be used as hydrates or aqueous mixtures, or in anhydrous form.

Specific examples of alkali metal hydrosulfides include sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide, rubidium hydrosulfide, cesium hydrosulfide, and mixtures of two or more of these. It is preferably used. These alkali metal hydrosulfides can be used as hydrates or aqueous mixtures, or in anhydrous form.

Alkali metal sulfides prepared in situ in the reaction system from alkali metal hydrosulfides and alkali metal hydroxides can also be used. Alternatively, an alkali metal sulfide can be prepared from an alkali metal hydrosulfide and an alkali metal hydroxide, and transferred to a polymerization vessel for use.

Alternatively, an alkali metal sulfide prepared in situ in a reaction system from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide can also be used. Alternatively, an alkali metal sulfide can be prepared from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide, and transferred to a polymerization vessel for use.

The amount of the charged sulfidating agent means the remaining amount obtained by subtracting the loss from the actual charged amount when a part of the sulfiding agent is lost before the start of the polymerization reaction due to dehydration or the like.

An alkali metal hydroxide and/or an alkaline earth metal hydroxide can be used together with the sulfidating agent. Specific examples of alkali metal hydroxides include sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and mixtures of two or more thereof. Specific examples of metal hydroxides include calcium hydroxide, strontium hydroxide, barium hydroxide, etc. Among them, sodium hydroxide is preferably used.

When an alkali metal hydrosulfide is used as the sulfidating agent, it is particularly preferable to use an alkali metal hydroxide at the same time. A range of 20 mol, preferably 1.00 to 1.15 mol, more preferably 1.005 to 1.100 mol can be exemplified.

[Polymerization solvent]
It is preferable to use an organic polar solvent as the polymerization solvent. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, 1,3-dimethyl-2-imidazolidine non-, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric acid triamide, dimethylsulfone, aprotic organic solvents represented by tetramethylene sulfoxide, and mixtures thereof; It is preferably used because of its high reaction stability. Among these, N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP) is particularly preferably used.

The organic polar solvent is used in an amount of 2.0 to 10 mol, preferably 2.25 to 6.0 mol, more preferably 2.5 to 5.5 mol per 1 mol of the sulfidating agent.

[Molecular weight modifier]
A monohalogen compound (which may not necessarily be an aromatic compound) is used in combination with the polyhalogenated aromatic compound to form a terminal of the polyphenylene sulfide resin to be produced or to adjust the polymerization reaction or molecular weight. be able to.

[Polymerization aid]
In order to obtain a polyphenylene sulfide resin with a relatively high degree of polymerization in a shorter time, it is also one of preferred embodiments to use a polymerization aid. The term "polymerization aid" as used herein means a substance that acts to increase the viscosity of the resulting polyphenylene sulfide resin. Specific examples of such polymerization aids include organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates and alkaline earth metal salts. metal phosphates and the like. These may be used alone or in combination of two or more. Among them, organic carboxylates, water, and alkali metal chlorides are preferable, and more preferable organic carboxylates are alkali metal carboxylates, and alkali metal chlorides are lithium chloride.

The alkali metal carboxylate has the general formula R(COOM)n (wherein R is an alkyl group, cycloalkyl group, aryl group, alkylaryl group or arylalkyl group having 1 to 20 carbon atoms). M is an alkali metal selected from lithium, sodium, potassium, rubidium and cesium, n is an integer of 1 to 3). Alkali metal carboxylates can also be used as hydrates, anhydrous or aqueous solutions. Specific examples of alkali metal carboxylates include lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-toluate, and mixtures thereof. can be mentioned.

The alkali metal carboxylate is prepared by adding an organic acid and one or more compounds selected from the group consisting of alkali metal hydroxides, alkali metal carbonates and alkali metal bicarbonates in approximately equal chemical equivalents to react them. may be formed by Among the above alkali metal carboxylates, lithium salts are highly soluble in the reaction system and have a large auxiliary effect, but are expensive, and potassium, rubidium and cesium salts are insufficiently soluble in the reaction system. Therefore, sodium acetate, which is inexpensive and has moderate solubility in the polymerization system, is most preferably used.

When these alkali metal carboxylates are used as polymerization aids, the amount used is usually in the range of 0.01 mol to 2 mol per 1 mol of the charged alkali metal sulfide. A range of 0.1 to 0.6 mol is preferred, and a range of 0.2 to 0.5 mol is more preferred.

When water is used as a polymerization aid, the amount added is usually in the range of 0.3 mol to 15 mol per 1 mol of the charged alkali metal sulfide. A range of 10 moles is preferred, and a range of 1 to 5 moles is more preferred.

Of course, it is possible to use two or more kinds of these polymerization aids in combination. For example, if an alkali metal carboxylate and water are used in combination, it is possible to increase the molecular weight with a smaller amount of each.

The timing of addition of these polymerization auxiliaries is not particularly specified, and they may be added at any time during the pre-process described later, at the start of polymerization, or during polymerization, or may be added in multiple portions. When an alkali metal carboxylate is used as a polymerization aid, it is more preferable to add it at the start of the preceding step or at the same time as the start of polymerization from the viewpoint of ease of addition. Further, when water is used as a polymerization aid, it is effective to add it during the polymerization reaction after charging the polyhalogenated aromatic compound.

[Polymerization stabilizer]
A polymerization stabilizer can also be used to stabilize the polymerization reaction system and prevent side reactions. The polymerization stabilizer contributes to stabilization of the polymerization reaction system and suppresses undesirable side reactions. One indication of side reactions is the formation of thiophenol, and the addition of a polymerization stabilizer can suppress the formation of thiophenol. Specific examples of polymerization stabilizers include compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal carbonates. Among them, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferred. The above-mentioned alkali metal carboxylate also acts as a polymerization stabilizer, and is included in one of the polymerization stabilizers. In addition, when an alkali metal hydrosulfide is used as the sulfidation agent, it is particularly preferable to use an alkali metal hydroxide at the same time. Oxides can also serve as polymerization stabilizers.

These polymerization stabilizers may be used alone or in combination of two or more. The amount of the polymerization stabilizer is usually 0.02 to 0.2 mol, preferably 0.03 to 0.1 mol, more preferably 0.04 to 0.09 mol, per 1 mol of the charged alkali metal sulfide. It is preferred to use in If this ratio is too small, the stabilizing effect will be insufficient.

The timing of addition of the polymerization stabilizer is not particularly specified. It is more preferable from the point that it is easy to add at the time of starting the process or at the time of starting the polymerization.

Next, a preferred method for producing the polyphenylene sulfide resin used in the present invention will be specifically described in order of the pre-process, the polymerization reaction process, the recovery process, and the post-treatment process, but of course the method is limited to this method. isn't it.

[pre-process]
In the method for producing a polyphenylene sulfide resin, the sulfidation agent is usually used in the form of a hydrate. Before adding the polyhalogenated aromatic compound, the mixture containing the organic polar solvent and the sulfidation agent is heated. , it is preferable to remove excess water out of the system.

Further, as described above, a sulfidating agent prepared from an alkali metal hydrosulfide and an alkali metal hydroxide either in situ in the reaction system or in a tank separate from the polymerization tank can also be used. can be done. Although this method is not particularly limited, it is desirable to add an alkali metal hydrosulfide and an alkali metal hydroxide to an organic polar solvent in an inert gas atmosphere at a temperature range of room temperature to 150°C, preferably room temperature to 100°C. In addition, there is a method in which the temperature is raised to at least 150° C. or higher, preferably 180 to 260° C., under normal pressure or reduced pressure to distill off water. A polymerization aid may be added at this stage. In addition, toluene or the like may be added to carry out the reaction in order to accelerate the distillation of water.

In the polymerization reaction, the amount of water in the polymerization system is preferably 0.3 to 10.0 mol per 1 mol of the charged sulfidating agent. Here, the amount of water in the polymerization system is the amount obtained by subtracting the amount of water removed from the polymerization system from the amount of water fed into the polymerization system. Moreover, the water to be charged may be in any form such as water, an aqueous solution, or water of crystallization.

[Polymerization reaction step]
A polyphenylene sulfide resin is produced by reacting a sulfidating agent and a polyhalogenated aromatic compound in an organic polar solvent within a temperature range of 200°C or higher and lower than 290°C.

When starting the polymerization reaction step, the organic polar solvent, the sulfidating agent and the polyhalogenated aromatic compound are preferably mixed in an inert gas atmosphere at a temperature range of room temperature to 240° C., preferably 100 to 230° C. . A polymerization aid may be added at this stage. These raw materials may be added in any order, or may be added at the same time.

Such a mixture is usually heated to a temperature in the range of 200°C to 290°C. There is no particular limitation on the heating rate, but a rate of 0.01 to 5°C/min is usually selected, and a range of 0.1 to 3°C/min is more preferable.

Generally, the temperature is finally raised to 250-290° C., and the reaction is carried out at that temperature for usually 0.25-50 hours, preferably 0.5-20 hours.

A method of raising the temperature to 270 to 290° C. after reacting at 200 to 260° C. for a certain period of time before reaching the final temperature is effective in obtaining a higher degree of polymerization. In this case, the reaction time at 200° C. to 260° C. is usually selected in the range of 0.25 hours to 20 hours, preferably in the range of 0.25 hours to 10 hours.

In order to obtain a polymer with a higher degree of polymerization, it may be effective to carry out polymerization in multiple stages. When the polymerization is carried out in multiple stages, it is effective that the conversion rate of the polyhalogenated aromatic compound in the system at 245° C. reaches 40 mol % or more, preferably 60 mol %.

The conversion rate of the polyhalogenated aromatic compound (hereinafter abbreviated as PHA) is a value calculated by the following formulas (a) and (b). The residual amount of PHA can usually be determined by gas chromatography.

When the polyhalogenated aromatic compound is added in excess molar ratio to the alkali metal sulfide Conversion rate = [PHA charge amount (mol) - PHA residual amount (mol)] / [PHA charge amount (mol) - PHA excess Amount (mole)] (a)
(B) Cases other than the above (A) Conversion rate = [PHA charging amount (mol) - PHA residual amount (mol)] / [PHA charging amount (mol)] (b)

[Recovery process]
In the method for producing a polyphenylene sulfide resin, after completion of polymerization, solids are recovered from the polymerization reaction product containing the polymer, solvent, and the like. As for the recovery method, any known method may be adopted.

For example, after completion of the polymerization reaction, a method of recovering the particulate polymer by slow cooling may be used. The slow cooling rate at this time is not particularly limited, but it is usually about 0.1° C./min to 3° C./min. It is not necessary to anneal at the same rate throughout the slow cooling process, and a method of slow cooling at a rate of 0.1 to 1° C./min until the polymer particles crystallize and precipitate, and then at a rate of 1° C./min or more may be used. May be adopted.

It is also one of the preferred methods to perform the above-mentioned recovery under rapid cooling conditions, and one preferred method of this recovery method is the flash method. The flash method is a method in which the polymerization reaction product is flashed from a high temperature and high pressure state (usually 250° C. or higher, 8 kg/cm 2 or higher) into a normal pressure or reduced pressure atmosphere, and the solvent is recovered and the polymer is powdered and recovered at the same time. , and the term "flash" as used herein means jetting the polymerization reactant from a nozzle. The flashing atmosphere is, for example, nitrogen or water vapor under normal pressure, and the temperature is usually selected in the range of 150°C to 250°C.

[Post-treatment process]
The polyphenylene sulfide resin may be subjected to acid treatment, hot water treatment, washing with an organic solvent, alkali metal or alkaline earth metal treatment after being produced through the above polymerization and recovery steps.

When acid treatment is performed, it is as follows. The acid used for the acid treatment of the polyphenylene sulfide resin is not particularly limited as long as it does not decompose the polyphenylene sulfide resin. Among them, acetic acid and hydrochloric acid are more preferably used, but those such as nitric acid that decompose and deteriorate the polyphenylene sulfide resin are not preferable.

The method of acid treatment includes a method such as immersing the polyphenylene sulfide resin in an acid or an aqueous solution of an acid. For example, when using acetic acid, a sufficient effect can be obtained by immersing the polyphenylene sulfide resin powder in an aqueous solution of pH 4 heated to 80 to 200° C. and stirring for 30 minutes. The pH after the treatment may be 4 or higher, eg, about pH 4-8. The acid-treated polyphenylene sulfide resin is preferably washed several times with water or warm water to remove residual acid or salt. The water used for washing is preferably distilled water or deionized water in the sense that the preferable chemical modification effect of the polyphenylene sulfide resin by acid treatment is not impaired.

The case of performing hot water treatment is as follows. When the polyphenylene sulfide resin is treated with hot water, the temperature of the hot water is preferably 100° C. or higher, more preferably 120° C. or higher, still more preferably 150° C. or higher, and particularly preferably 170° C. or higher. If the temperature is less than 100°C, the preferred chemical modification effect of the polyphenylene sulfide resin is small, which is not preferable.

The water used is preferably distilled water or deionized water in order to exhibit the desired chemical modification effect of the polyphenylene sulfide resin by washing with hot water. There are no particular restrictions on the operation of the hot water treatment, and it is carried out by adding a predetermined amount of polyphenylene sulfide resin to a predetermined amount of water, heating and stirring the mixture in a pressure vessel, or performing continuous hot water treatment. As for the ratio of the polyphenylene sulfide resin and water, it is preferable that the amount of water is large, but usually a bath ratio of 200 g or less of the polyphenylene sulfide resin per 1 liter of water is selected.

In addition, since decomposition of terminal groups is undesirable, the atmosphere for the treatment is desirably an inert atmosphere in order to avoid this. Further, the polyphenylene sulfide resin that has undergone this hot water treatment operation is preferably washed several times with hot water to remove residual components.

When washing with an organic solvent, it is as follows. The organic solvent used for washing the polyphenylene sulfide resin is not particularly limited as long as it does not decompose the polyphenylene sulfide resin. Nitrogen-containing polar solvents such as dimethylimidazolidinone, hexamethylphosphorasamide, and piperazinones; sulfoxide/sulfone solvents such as dimethylsulfoxide, dimethylsulfone, and sulfolane; ketone solvents such as acetone, methylethylketone, diethylketone, and acetophenone; , ether solvents such as dipropyl ether, dioxane, and tetrahydrofuran; halogen solvents such as chloroform, methylene chloride, trichlorethylene, ethylene dichloride, perchlorethylene, monochloroethane, dichloroethane, tetrachloroethane, perchloroethane, and chlorobenzene; alcohol-phenolic solvents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, polypropylene glycol; and aromatic hydrocarbon solvents such as benzene, toluene, and xylene. be done. Among these organic solvents, the use of N-methyl-2-pyrrolidone, acetone, dimethylformamide, chloroform and the like is particularly preferred. These organic solvents are used singly or in combination of two or more.

As a method for washing with an organic solvent, there is a method such as immersing the polyphenylene sulfide resin in an organic solvent. There is no particular limitation on the washing temperature when washing the polyphenylene sulfide resin with an organic solvent, and any temperature from room temperature to about 300° C. can be selected. There is a tendency that the higher the washing temperature, the higher the washing efficiency. It is also possible to wash under pressure in a pressure vessel at a temperature above the boiling point of the organic solvent. Also, the cleaning time is not particularly limited. Although it depends on the cleaning conditions, in the case of batch cleaning, a sufficient effect can be obtained by cleaning for 5 minutes or more. It is also possible to wash continuously.

Examples of the method of treating with an alkali metal or alkaline earth metal include a method of adding an alkali metal salt or an alkaline earth metal salt before, during, or after the pre-process, a method of adding an alkali metal salt or an alkaline earth metal salt before, during, or after the pre-process, before, during, or during the polymerization process. Examples include a method of adding an alkali metal salt or alkaline earth metal salt to the polymerization reactor afterward, or a method of adding an alkali metal salt or alkaline earth metal salt at the beginning, middle or end of the washing process. Among them, the easiest method includes a method of adding an alkali metal salt or an alkaline earth metal salt after removing residual oligomers and residual salts by washing with an organic solvent or washing with warm or hot water. Alkali metals and alkaline earth metals are preferably introduced into the polyphenylene sulfide resin in the form of alkali metal ions such as acetates, hydroxides and carbonates, and alkaline earth metal ions. Further, it is preferable to remove excess alkali metal salt and alkaline earth metal salt by washing with warm water or the like. When the alkali metal or alkaline earth metal is introduced, the concentration of the alkali metal ion or alkaline earth metal ion is preferably 0.001 mmol or more, more preferably 0.01 mmol or more, relative to 1 g of PPS. The temperature is preferably 50°C or higher, more preferably 75°C or higher, and particularly preferably 90°C or higher. Although there is no particular upper limit temperature, 280° C. or less is usually preferable from the viewpoint of operability. The bath ratio (the weight of the washing liquid to the weight of the dry PPS) is preferably 0.5 or more, more preferably 3 or more, and even more preferably 5 or more.

In addition, the polyphenylene sulfide resin can also be used after being polymerized by thermal oxidation cross-linking treatment by heating in an oxygen atmosphere and heating with addition of a cross-linking agent such as a peroxide after completion of polymerization.

When dry heat treatment is performed for the purpose of increasing the molecular weight by thermal oxidation crosslinking, the temperature is preferably 160 to 260°C, more preferably 170 to 250°C. Also, the oxygen concentration is desirably 5% by volume or more, more preferably 8% by volume or more. Although there is no particular upper limit for the oxygen concentration, the upper limit is about 50% by volume. The treatment time is preferably 0.5 to 100 hours, more preferably 1 to 50 hours, even more preferably 2 to 25 hours. The heat treatment device may be a normal hot air dryer or a heating device with a rotating or stirring blade. For efficient and more uniform processing, a rotary or heating device with a stirring blade may be used. It is more preferable to use

It is also possible to perform dry heat treatment for the purpose of suppressing thermal oxidation cross-linking and removing volatile matter. The temperature is preferably 130-250°C, more preferably 160-250°C. In this case, the oxygen concentration is desirably less than 5% by volume, more preferably less than 2% by volume. The treatment time is preferably 0.5 to 50 hours, more preferably 1 to 20 hours, even more preferably 1 to 10 hours. The heat treatment device may be a normal hot air dryer or a heating device with a rotating or stirring blade. For efficient and more uniform processing, a rotary or heating device with a stirring blade may be used. It is more preferable to use

However, from the viewpoint of exhibiting excellent toughness, the polyphenylene sulfide resin of the present invention is a substantially linear polyphenylene sulfide resin that is not subjected to high molecular weight by thermal oxidation crosslinking treatment, or is lightly oxidatively crosslinked. A semi-crosslinked polyphenylene sulfide resin is preferred. Moreover, in the present invention, a plurality of polyphenylene sulfide resins having different melt viscosities may be mixed and used.

<(B) Bisphenol derivative>
The (B) bisphenol derivative of the present invention is not particularly limited, but at least one (B) bisphenol derivative selected from the group consisting of (i), (ii) and (iii) can be used.
(i) (B) a bisphenol derivative represented by the general formula (1)

(Here, R1 and R2 are each independently a hydrogen atom or an alkyl group, and R1
and R2 may be the same or different)
(ii) (B) a bisphenol derivative represented by the general formula (2)

(Here, X is any of -(C=Cl2)-, -CH2-, -SO2-, -S-, -C6H5-, -O-, -(C=O)-)
(iii) (B) a bisphenol derivative represented by the general formula (3)

(Here, R3 and R4 are each independently a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R3 and R4 may be the same or different; j and k are each It is independently an integer of 1 or more, and the sum of n and m is 14 to 40.)
(i) More specifically, bisphenol A, bisphenol B, bisphenol E and the like can be exemplified as the (B) bisphenol derivative represented by the general formula (1).

(ii) More specifically, the (B) bisphenol derivative represented by the general formula (1) includes bisphenol C, bisphenol F, bisphenol S, bisphenol T, bisphenol Z, bis(4-hydroxyphenyl) ether, 4 , 4′-dihydroxybenzophenone and the like.

(iii) The (B) bisphenol derivative represented by the general formula (1) has a structure in which ethylene oxide is added to both ends of the central part composed of a bisphenol-type skeleton (that is, each of the two benzene rings in the bisphenol-type skeleton structure to which ethylene oxide is added), and R3 and R4 are each independently preferably a hydrogen atom or an alkyl group having 1 to 2 carbon atoms. Further, (iii) (B) the bisphenol derivative represented by the general formula (1) may be a mixture.

(iii) The (B) bisphenol derivative represented by the general formula (1) has an added amount of ethylene oxide attached to both ends of the central part composed of the bisphenol-type skeleton (that is, to each of the two benzene rings of the bisphenol-type skeleton (Addition amount of ethylene oxide added) does not need to be the same for each of the two benzene rings of the bisphenol-type skeleton, but the (B) bisphenol derivative represented by the above (iii) general formula (1) However, since it is generally a compound obtained by adding ethylene oxide to a bisphenol compound, the amount of ethylene oxide added to each of the two benzene rings of the bisphenol skeleton is the same as that of the two benzene rings of the bisphenol skeleton In many cases, the rings are not so different from each other. In addition, the bonding position of the ethylene oxide bonded to each of the two benzene rings of the bisphenol-type skeleton may be any of the 2, 3, 4, 5 and 6 positions of the benzene ring, preferably the 4 position. Moreover, the positions of the ethylene oxide bonded to the two benzene rings of the bisphenol-type skeleton may be the same or different, and are preferably the same.

<Method for producing fiber-reinforced resin substrate>
The fiber-reinforced thermoplastic resin substrate of the embodiment of the present invention can be obtained by impregnating continuous reinforcing fibers with a polyphenylene sulfide resin composition.

The method for impregnating continuous reinforcing fibers with the polyphenylene sulfide resin composition includes, for example, a film method in which the reinforcing fiber bundles are impregnated with the polyphenylene sulfide resin composition by melting and pressurizing a film-like polyphenylene sulfide resin composition, After blending the fibrous polyphenylene sulfide resin composition and the reinforcing fiber bundle, the fibrous polyphenylene sulfide resin composition is melted and pressurized to impregnate the reinforcing fiber bundle with the thermoplastic resin. A powder method of impregnating the reinforcing fiber bundle with the polyphenylene sulfide resin composition by dispersing the polyphenylene sulfide resin composition in the interstices of the fibers in the reinforcing fiber bundle, then melting the powdered polyphenylene sulfide resin composition and applying pressure, A drawing method can be used, in which a reinforcing fiber bundle is immersed in a molten polyphenylene sulfide resin composition and pressurized to impregnate the reinforcing fiber bundle with the polyphenylene sulfide resin composition. The drawing method is preferred because it enables the preparation of a wide variety of fiber-reinforced thermoplastic resin base materials such as various thicknesses and fiber volume contents.

The thickness of the fiber-reinforced thermoplastic resin substrate in the present invention is preferably 0.1 to 10 mm. If the thickness is 0.1 mm or more, the strength of the molded article obtained using the fiber-reinforced polyphenylene sulfide resin substrate can be improved. 0.2 mm or more is more preferable. On the other hand, if the thickness is 1.5 mm or less, it is easier to impregnate the reinforcing fibers with the polyphenylene sulfide resin composition. It is more preferably 1 mm or less, still more preferably 0.7 mm or less, and even more preferably 0.6 mm or less.

Moreover, in the fiber-reinforced thermoplastic resin substrate according to the present invention, it is preferable to contain reinforcing fibers in an amount of 20% by volume or more and 65% by volume or less in 100% by volume of the entire fiber-reinforced thermoplastic resin substrate. By containing 20% by volume or more of the reinforcing fiber, the strength of the molded article obtained using the fiber-reinforced thermoplastic resin substrate can be further improved. 30% by volume or more is more preferable, and 40% by volume or more is even more preferable. On the other hand, by containing 65% by volume or less of the reinforcing fibers, it is easier to impregnate the reinforcing fibers with the thermoplastic. 60% by volume or less is more preferable, and 55% by volume or less is even more preferable. The volume content can be adjusted within a desired range by adjusting the input amounts of the reinforcing fiber and the polyphenylene sulfide resin.

The volume content (Vf) of the reinforcing fibers in the fiber-reinforced thermoplastic resin substrate of the present invention is determined by measuring the mass W0 of the fiber-reinforced thermoplastic resin substrate, and then exposing the fiber-reinforced thermoplastic resin substrate in the air at 500°C. is heated for 30 minutes to burn off the thermoplastic resin component, the mass W1 of the remaining reinforcing fibers is measured, and can be calculated by the following formula (c).
Vf (% by volume) = (W1/ρf)/{W1/ρf+(W0−W1)/ρr}×100
... (c)
ρf: Density of reinforcing fiber (g/cm ³ )
ρr: Density of polyphenylene sulfide resin composition (g/cm ³ )

Moreover, the fiber-reinforced thermoplastic resin substrate of the embodiment of the present invention can be selected to have a desired impregnability according to its usage and purpose. For example, prepreg with higher impregnability, semi-impregnated semi-preg, fabric with low impregnation, and the like can be used. In general, molding materials with higher impregnating properties are preferable because molded articles with excellent mechanical properties can be obtained in a short period of time.

The method of applying heat and/or pressure includes, for example, a press molding method in which a fiber-reinforced thermoplastic resin laminated in an arbitrary configuration is placed in a mold or on a press plate, and then the mold or press plate is closed and pressurized. An autoclave molding method in which molding materials laminated in an arbitrary configuration are put into an autoclave and pressurized and heated. Wrapping the molding materials laminated in an arbitrary configuration with a film, etc., the inside is decompressed and the oven is pressurized at atmospheric pressure. A bagging molding method in which the resin is heated inside, a wrapping tape method in which a fiber-reinforced thermoplastic resin laminated with an arbitrary configuration is wrapped with a tape while applying tension and heated in an oven, and a fiber-reinforced polyphenylene sulfide resin laminated with an arbitrary configuration is molded. and an internal pressure molding method in which gas or liquid is injected into a core placed in a mold and pressurized. In particular, a molding method in which a mold is used to press is preferably used, since the voids in the obtained molded article are few and a molded article having excellent appearance quality can be obtained.

As a press molding method, a fiber-reinforced resin base material is placed in advance in a mold, pressure and heat are applied while clamping the mold, and then the fiber-reinforced resin base material is formed by cooling the mold while the mold is clamped. A hot press method that cools and obtains a molded product, or a fiber-reinforced resin base material that is heated in advance to a temperature above the melting temperature of the thermoplastic resin with a heating device such as a far-infrared heater, a heating plate, a high-temperature oven, or a dielectric heater. in a melted/softened state, placed on the mold that will be the lower surface of the mold, then the mold is closed and clamped, and then pressurized and cooled. Stamping molding can be adopted. The press molding method is not particularly limited, but stamping molding is desirable from the viewpoint of speeding up the molding cycle and improving productivity.

The fiber-reinforced resin base material and the molded product in the present invention can be formed by integral molding such as insert molding and outsert molding, bonding methods with excellent productivity such as correction treatment by heating, heat welding, vibration welding, and ultrasonic welding. Integration using an adhesive can be performed to obtain a composite.

A composite molded article in which a fiber-reinforced resin base material in the present invention and a molded article containing a thermoplastic resin are joined at least partially is preferred.

The molded article (molding substrate and molded article) containing a thermoplastic resin integrated with a fiber-reinforced resin base material in the present invention is not particularly limited, and examples include resin materials and molded articles, metal materials and molded articles, Examples include inorganic materials and molded articles. Of these, resin materials and molded articles are preferred in terms of adhesive strength with the fiber-reinforced thermoplastic resin of the present invention.

The molding material integrated with the fiber-reinforced resin base material and the matrix resin of the molded product in the present invention may be the same resin as the fiber-reinforced resin base material and the molded product, or may be a different resin. good. In order to further increase the adhesive strength, it is preferable that the resins are of the same type. If the resins are of different types, it is more preferable to provide a resin layer at the interface.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited thereto.

In Examples and Comparative Examples, the following polyphenylene sulfide resins, additives, and reinforcing fibers were used.

[Polyphenylene sulfide resin]
PPS-1 to PPS-6 were synthesized in Reference Examples 1 to 6 below.

[Reference Example 1 (Synthesis of PPS-1)]
In a 70 liter autoclave equipped with a stirrer, 8.27 kg 47.5% sodium hydrosulfide, 2.96 kg 96% sodium hydroxide, 11.43 kg N-methyl-2-pyrrolidone (NMP), 2.58 kg sodium acetate, and 10.5 kg of ion-exchanged water was charged and gradually heated to 245°C over about 3 hours while passing nitrogen under normal pressure. After distilling 14.8 kg of water and 280 g of NMP, the reactor was cooled to 160°C.

Then 10.2 kg of p-dichlorobenzene, 22.5 g of 1,2,4-trichlorobenzene and 9.00 kg of NMP are added, the reaction vessel is sealed under nitrogen gas and stirred at 240 rpm while stirring at 0.6° C./min. The temperature was raised to 238°C at a rate of . After reacting at 238°C for 95 minutes, the temperature was raised to 270°C at a rate of 0.8°C/min. After reacting at 270° C. for 150 minutes, the mixture was cooled to 250° C. at a rate of 1.3° C./min while injecting 1.26 kg of water over 15 minutes. After that, it was cooled to 200° C. at a rate of 1.0° C./min, and then rapidly cooled to near room temperature.

The content was taken out, washed twice with 40.0 kg of NMP, and filtered. This was washed several times with 56.0 kg of deionized water and separated by filtration, and then washed with 70.0 kg of 0.05% by weight aqueous acetic acid solution and separated by filtration. After washing with 70.0 kg of ion-exchanged water and filtering, the resulting water-containing PPS particles were dried with hot air at 80°C and then dried at 120°C under reduced pressure. The resulting PPS-1 had a melt viscosity of 320 Pa·s and a carboxyl group content of 10 μmol/g.

[Reference Example 2 (Synthesis of PPS-2)]
In a 70 liter autoclave equipped with a stirrer, 8.27 kg 47.5% sodium hydrosulfide, 2.96 kg 96% sodium hydroxide, 11.43 kg N-methyl-2-pyrrolidone (NMP), 2.58 kg sodium acetate, and 10.5 kg of ion-exchanged water was charged and gradually heated to 245°C over about 3 hours while passing nitrogen under normal pressure. After distilling 14.8 kg of water and 280 g of NMP, the reactor was cooled to 160°C.

Next, 10.2 kg of p-dichlorobenzene and 9.00 kg of NMP were added, the reaction vessel was sealed under nitrogen gas, and the temperature was raised to 238° C. at a rate of 0.6° C./min while stirring at 240 rpm. After reacting at 238°C for 95 minutes, the temperature was raised to 270°C at a rate of 0.8°C/min. After reacting at 270° C. for 150 minutes, the mixture was cooled to 250° C. at a rate of 1.3° C./min while injecting 1.26 kg of water over 15 minutes. After that, it was cooled to 200° C. at a rate of 1.0° C./min, and then rapidly cooled to near room temperature.

The content was taken out, washed twice with 40.0 kg of NMP, and filtered. This was washed several times with 56.0 kg of deionized water and separated by filtration, and then washed with 70.0 kg of 0.05% by weight aqueous acetic acid solution and separated by filtration. After washing with 70.0 kg of ion-exchanged water and filtering, the resulting water-containing PPS particles were dried with hot air at 80°C and then dried at 120°C under reduced pressure. The resulting PPS-2 had a melt viscosity of 225 Pa·s and a carboxyl group content of 18 μmol/g.
[Reference Example 5 (Synthesis of PPS-3)]
In a 70 liter autoclave equipped with a stirrer, 8.27 kg 47.5% sodium hydrosulfide, 2.96 kg 96% sodium hydroxide, 11.43 kg N-methyl-2-pyrrolidone (NMP), 2.58 kg sodium acetate, and 10.5 kg of ion-exchanged water was charged and gradually heated to 245°C over about 3 hours while passing nitrogen under normal pressure. After distilling 14.8 kg of water and 280 g of NMP, the reactor was cooled to 160°C.

Next, 10.2 kg of p-dichlorobenzene and 90.0 kg of NMP were added, the reaction vessel was sealed under nitrogen gas, and the temperature was raised to 238° C. at a rate of 0.6° C./min while stirring at 240 rpm. After reacting at 238°C for 95 minutes, the temperature was raised to 270°C at a rate of 0.8°C/min. After reacting at 270° C. for 200 minutes, the mixture was cooled to 250° C. at a rate of 1.3° C./min while injecting 1.26 kg of water over 15 minutes. After that, it was cooled to 200° C. at a rate of 1.0° C./min, and then rapidly cooled to near room temperature.

The content was taken out, washed twice with 30.0 kg of NMP, and filtered. This was washed several times with 56.0 kg of deionized water and filtered to obtain undried PPS particles. 20 kg of the obtained undried PPS resin and 110 g of calcium acetate monohydrate were added to 200 kg of ion-exchanged water, stirred at 70° C. for 30 minutes, and filtered to separate solid and liquid. 20 kg of ion-exchanged water was added to the obtained solid content, and after stirring at 70° C. for 30 minutes, the solid content was collected by filtration. The solid content thus obtained was dried at 120° C. under a stream of nitrogen.
The resulting PPS-3 had a melt viscosity of 235 Pa·s and a carboxyl group content of 0 μmol/g.

[Additive]
Bisphenol derivative-1: Bisphenol A (manufactured by Tokyo Chemical Industry Co., Ltd.)
Bisphenol derivative-2: Bisphenol A ethylene oxide 30 mol adduct (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.)
Polyethylene glycol compound: polyethylene glycol 2000 (manufactured by Tokyo Chemical Industry Co., Ltd.)
Amine compound: polyethyleneimine (branched) (manufactured by Sigma-Aldrich)

[Reinforcing fiber]
(CF-1): Carbon fiber bundle (manufactured by Toray Industries, Inc., product name T700S-12K)
[Weight average molecular weight of PPS resin]
The weight average molecular weight (Mw) and polydispersity of the PPS resin were calculated in terms of polystyrene using gel permeation chromatography (GPC). GPC measurement conditions are shown below.
Equipment: SSC-7110 (Senshu Science)
Column name: Shodex UT806M×2 Eluent: 1-chloronaphthalene Detector: Refractive index detector Column temperature: 210°C Pre-temperature bath temperature: 250°C
Pump thermostat temperature: 50°C
Detector temperature: 210°C
Flow rate: 1.0 mL/min
Sample injection volume: 300 μL (slurry: about 0.2% by weight).

[Carboxyl Group Amount of Polyphenylene Sulfide Resin]
The carboxyl group content of the polyphenylene sulfide resin was calculated using a Fourier transform infrared spectrometer (hereinafter abbreviated as FT-IR).

First, benzoic acid was measured by FT-IR as a standard substance, and the absorption intensity (b1) of the peak at 3066 cm ^-1 which is the absorption of the CH bond of the benzene ring and the peak at 1704 cm ^-1 which is the absorption of the carboxyl group. The absorption intensity (c1) was read, and the amount of carboxyl groups (U1) per unit of benzene ring (U1) = (c1)/[(b1)/5] was determined. Next, the polyphenylene sulfide resin was melt-pressed at 320° C. for 1 minute and then quenched to obtain an amorphous film, which was then subjected to FT-IR measurement. Reading the absorption intensity (b2) at 3066 cm ^-1 and the absorption intensity (c2) at 1704 cm ^-1 , the amount of carboxyl groups (U2) per 1 unit of benzene ring, (U2) = (c2) / [(b2) / 4] asked. The carboxyl group content per gram of polyphenylene sulfide resin was calculated from the following formula (d).
Carboxyl group amount (μmol/g) of polyphenylene sulfide resin=(U2)/(U1)/108.161×1000000 (d)

[Measurement of Radical Generation Amount]
The amount of radicals generated was calculated by an electron spin resonance method using EMXplus (manufactured by BRUKER). 20 mg of sample was weighed out, placed in an ESR sample tube (quartz tube with an inner diameter of about 3.5 mmφ), set in the apparatus, air was circulated, and then measured at room temperature (25°C) before heating. The temperature was raised from room temperature to 350°C at a heating rate of 20°C/min, and the amount of radicals generated when the temperature was maintained for 30 minutes after reaching 350°C was calculated by simultaneously measuring the Mn marker (Mn ²⁺ in MgO). .

[Measurement of fiber volume content (Vf)]
The fiber volume content of the fiber-reinforced PPS resin base material is obtained by measuring the mass W0 (g) of the fiber-reinforced polyphenylene sulfide resin base material, then eluting the polyphenylene sulfide resin from the fiber-reinforced resin base material with 1-chloronaphthalene, The mass W1 (g) of the remaining reinforcing fibers after drying was measured, and the volume content (Vf: volume %) of the fiber-reinforced resin substrate was calculated by the following formula (c).
Vf (% by volume) = (W1/ρf)/{W1/ρf+(W0−W1)/ρr}×100
... (c)
ρf: Density of reinforcing fiber (g/cm ³ )
ρr: Density of resin composition (g/cm ³ )

[Composite mechanical properties (bending test)]
The fiber reinforced resin substrate (width 50 mm × thickness 0.08 mm, unidirectional substrate) obtained from each example and comparative example is laminated in the 0 ° direction so that the thickness is 2.0 mm × width 100 mm × length 250 mm. A fiber-reinforced resin molded product was obtained by press molding. For bending test measurement, this molded product was cut into a rectangular shape of width 15 mm×length 125 mm×thickness 2.0 mm, and a bending test (each n=5) was performed in accordance with ASTM D790. In addition, it can be said that the composite material having higher flexural strength and flexural modulus has better mechanical properties.

[Composite mechanical properties (interface strength)]
A method similar to that described in Japanese Patent Laid-Open No. 2018-135624, that is, a single yarn is extracted from a carbon fiber bundle, sandwiched from above and below with a resin film laminated so as to have a thickness of 0.4 mm or more, and with a heat press device, After being heated and pressurized, it was cooled to room temperature while maintaining the pressurized state to obtain a molded plate in which the carbon fiber single yarn was embedded. A dumbbell-shaped test piece for interfacial shear strength measurement was punched out from this molded plate using an SD type lever cutting machine.

A dumbbell-shaped sample was clamped at both ends and a tensile force was applied in the direction of the fiber axis (longitudinal direction) to produce a strain of 12% at a speed of 2.0 mm/min. After that, a 20 mm central portion of the test piece was cut off, sandwiched between glass plates on a hot plate, and heated to the melting point of the thermoplastic resin or higher. Fragmented fiber lengths inside the sample that had been made transparent by heating were observed under a microscope. Further, the critical fiber length lc was calculated from the average broken fiber length la by the formula lc (μm)=(4/3)×la (μm). The strand tensile strength σ and the diameter d of the carbon fiber single yarn were measured, and the interfacial shear strength, which is an index of the adhesive strength between the carbon fiber and the resin interface, was calculated by the following formula (e). In the examples, the average of the number of measurements n=5 was used as the test result.
Interfacial shear strength (MPa) = σ (MPa) × d (μm) / (2 × lc) (μm) (e)

[Examples 1 to 3, Comparative Examples 1 to 8 (resin composition pellet manufacturing method)]
After dry blending each raw material other than the carbon fiber bundles shown in Table 1 at the ratio shown in Table 1, a TEX30α type twin screw extruder manufactured by Japan Steel Works, Ltd. (screw diameter 30 mm, L / D = 45) equipped with a vacuum vent , 5 kneading parts, co-rotating fully meshing type screws), screw rotation speed 300 rpm, discharge rate 20 kg / hr, cylinder temperature is set so that the die resin temperature is 300 ° C. Melt kneading. It was pelletized by a strand cutter and subjected to the above evaluation.

[Examples 1 to 3, Comparative Examples 1 to 8 (fiber-reinforced resin substrate manufacturing method)]
Sixteen bobbins wound with carbon fiber bundles were prepared, and the carbon fiber bundles were fed out continuously from each bobbin through a yarn guide. The continuously delivered carbon fiber bundles were impregnated in the impregnation die with the resin composition obtained by the method described above, metered from the filled feeder. The carbon fiber impregnated with the resin composition in the impregnation die was continuously drawn out from the nozzle of the impregnation die using a take-off roll at a drawing speed of 1 m/min. The temperature at which the carbon fiber is pulled out is called the processing temperature. The drawn carbon fiber bundle was passed through a cooling roll to cool and solidify the resin composition, and was wound up by a winding machine as a continuous fiber-reinforced resin base material. The resulting fiber-reinforced resin base material had a thickness of 0.08 mm and a width of 50 mm, and the reinforcing fibers were arranged in one direction to obtain a fiber-reinforced resin base material having a volume content of 60%. The obtained fiber-reinforced resin base material was subjected to the above evaluation. Table 1 shows the evaluation results.

The results of Examples 1 to 3 and Comparative Examples 1 to 8 will be compared and explained.

As shown in Table 1, the fiber-reinforced resin substrates of Examples 1 to 3 of the present invention were extremely excellent in interfacial shear strength and 90° bending strength.

On the other hand, as shown in Table 1, in the case of the fiber-reinforced resin substrates of Comparative Examples 1 to 3 using the polyphenylene sulfide resin compositions in which the blending ratio of the bisphenol derivative and the amount of radical generation are outside the range of the present invention, the 90° bending The strength was less than 130 MPa. In addition, polyphenylene sulfide resin compositions using additives other than the bisphenol derivative of the present invention, and fiber-reinforced resin base materials of Comparative Examples 4 and 5 using polyphenylene sulfide resin compositions in which the amount of radical generation is outside the range of the present invention. In this case, the interface strength was low, about 30 MPa. In the case of the fiber-reinforced resin substrates of Comparative Examples 6 to 8 using the polyphenylene sulfide resin (PPS-3) whose radical generation amount and carboxyl group amount are outside the range of the present invention, the 90° bending strength is low, less than 130 MPa. rice field.

The fiber-reinforced resin base material and the molded article thereof in the present invention are used for various purposes such as aircraft parts, automobile parts, electric/electronic parts, building materials, various containers, daily necessities, household goods and sanitary goods, taking advantage of their excellent properties. can do. The fiber-reinforced resin base material and the molded article thereof according to the embodiment of the present invention are particularly suitable for aircraft engine peripheral parts, aircraft exterior parts, automobile body parts, vehicle frames, and automobiles, which require impregnation, heat aging resistance, and surface appearance. It is particularly preferably used for engine peripheral parts, automobile underhood parts, automobile gear parts, automobile interior parts, automobile exterior parts, intake and exhaust system parts, engine cooling water system parts, automobile electrical parts, and electric/electronic parts. Specifically, the fiber-reinforced resin and the molded article thereof according to the embodiments of the present invention are used for aircraft engine peripheral parts such as fan blades, landing gear pods, winglets, spoilers, edges, rudders, elevators, failings, ribs, etc. Aircraft-related parts, various seats, front bodies, under bodies, various pillars, various members, various frames, various beams, various supports, various rails, automobile body parts such as various hinges, engine covers, air intake pipes, timing belt covers, Automotive engine peripheral parts such as intake manifolds, filler caps, throttle bodies, cooling fans, automotive undercarriages such as cooling fans, radiator tank tops and bases, cylinder head covers, oil pans, brake piping, fuel piping tubes, waste gas system parts, etc. Automotive gear parts such as hood parts, gears, actuators, bearing retainers, bearing cages, chain guides, chain tensioners, shift lever brackets, steering lock brackets, key cylinders, door inner handles, door handle cowls, interior mirror brackets, air conditioner switches, Automotive interior parts such as instrument panels, console boxes, glove boxes, steering wheels, trims, front fenders, rear fenders, fuel lids, door panels, cylinder head covers, door mirror stays, tailgate panels, license garnishes, roof rails, engine mount brackets, rear Automotive exterior parts such as garnishes, rear spoilers, trunk lids, rocker moldings, moldings, lamp housings, front grilles, mudguards, side bumpers, air intake manifolds, intercooler inlets, turbochargers, exhaust pipe covers, inner bushes, bearing retainers, engines Intake and exhaust system parts such as mounts, engine head covers, resonators and throttle bodies, engine cooling water system parts such as chain covers, thermostat housings, outlet pipes, radiator tanks, oil pumps and delivery pipes, connectors and wire harness connectors, motor parts , lamp sockets, sensor in-vehicle switches, combination switches and other automotive electrical parts, electrical and electronic parts such as generators, motors, transformers, current transformers, voltage regulators, rectifiers, resistors, inverters, relays, Power contacts, switches, circuit breakers, switches, knife switches, multipolar rods, motor cases, TV housings, laptop computer housings and internal parts, CRT display housings and internal parts, printer housings and internal parts, mobile phones, mobile computers , mobile terminal housings and internal parts such as handheld mobiles, IC and LED compatible housings, capacitor base plates, fuse holders, various gears, various cases, electric parts such as cabinets, connectors, SMT compatible connectors, card connectors, jacks, Coils, coil bobbins, sensors, LED lamps, sockets, resistors, relays, relay cases, reflectors, small switches, power supply parts, coil bobbins, capacitors, variable condenser cases, optical pickup chassis, oscillators, various terminal boards, transformers, plugs, Printed circuit boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, Si power modules and SiC power modules, semiconductors, liquid crystals, FDD carriages, FDD chassis, motor brush holders, transformer parts, parabolic antennas, computers It is preferably used for electronic parts such as related parts.

Claims (5)

A fiber-reinforced thermoplastic resin substrate obtained by impregnating a plurality of continuous reinforcing fibers with a polyphenylene sulfide resin composition, wherein the amount of radicals generated from the polyphenylene sulfide resin composition measured by the following electron spin resonance method is 3. 0×10 ¹⁶ pieces/g or more and 3.5×10 ¹⁶ pieces/g or less, a fiber-reinforced thermoplastic resin base material.
(Measurement condition)
The amount of radicals generated when the temperature is raised from room temperature to 350°C at a temperature elevation rate of 20°C/min and held for 30 minutes after reaching 350°C. The fiber-reinforced resin substrate according to claim 1, wherein the polyphenylene sulfide resin composition comprises (A) a polyphenylene sulfide resin and (B) a bisphenol derivative. Claim 1 or 2, wherein (A) is 99.6 to 99.9% by weight and (B) is 0.4 to 0.1% by weight, with the total of (A) and (B) being 100% by weight. A fiber reinforced thermoplastic resin substrate as described. The fiber-reinforced thermoplastic resin substrate according to any one of claims 1 to 3, wherein the polyphenylene sulfide resin (A) has a carboxyl group content of 5 to 250 µmol/g. The fiber-reinforced thermoplastic resin substrate according to any one of claims 1 to 4, wherein the fiber volume content of the fiber-reinforced resin substrate is 20 to 65% by volume.