JP2021147547A - Resin composition, fiber-reinforced resin molding, multilayer pipe, and method for manufacturing fiber-reinforced resin molding - Google Patents

Abstract

To provide a resin composition for obtaining a fiber-reinforced resin molding which is reduced in shrinkage when being cured, a fiber-reinforced resin molding using the resin composition, a multilayer pipe, and a method for manufacturing a fiber-reinforced resin molding.SOLUTION: An FRP pipe 10 having a fiber-reinforced base material, and an FRP layer 11 that is a fiber-reinforced resin molding containing a cured product of a resin composition coated onto the fiber-reinforced base material. The resin composition contains a thermosetting resin, and an inorganic filler having a particle size of 0.008-0.5 μm and an oil absorption amount of 50-300 mL/100 g.SELECTED DRAWING: Figure 1

Description

The present invention relates to a resin composition, a fiber-reinforced resin molded product, a multilayer tube, and a method for producing a fiber-reinforced resin molded product.
More specifically, the present invention relates to a resin composition for obtaining a fiber-reinforced resin molded body, a fiber-reinforced resin molded body using this resin composition, a multilayer tube, and a method for producing a fiber-reinforced resin molded body.

The fiber reinforced plastic (FRP) molded product contains a fiber reinforced base material and a matrix resin. Fiber reinforced resin molded products are used in many industrial fields as metal substitutes because of their high strength, high rigidity, and light weight.
For example, a pipe using a fiber reinforced resin molded body is used in fields such as factories, public pipes, and power plants because of its superior pressure resistance, corrosion resistance, light weight, and chemical resistance.

As the matrix resin of the fiber-reinforced resin molded product, a thermosetting resin composed of an oligomer having an unsaturated bond and a vinyl monomer having copolymerizability thereof is used, but there is a problem that curing shrinkage occurs during curing and molding. have.
Such volume shrinkage not only significantly impairs the dimensional accuracy and appearance of the molded product, but also causes stress to remain at the interface between the resin and the fiber-reinforced base material, making it impossible to obtain the desired strength.

Further, for example, when a strip-shaped bundle of long fibrous reinforcing fibers is supplied to a rotating core tube or the like and wound to form a tube by a filament winding method, the matrix resin applied to the bundle of reinforcing fibers is strip-shaped. It overflows to the outside in the width direction of the bundle of reinforcing fibers, the reinforcing fibers do not exist, and a resin-only portion (hereinafter, may be referred to as a “resin-rich portion”) is formed.

This resin-rich portion has a larger amount of shrinkage during curing than the portion where the reinforcing fibers are present. As a result, there is a problem that linear dents are spirally generated along the resin-rich portion.
When the linear dent extends to the surface of the pipe, dust accumulates in the dent and retains water when used outdoors, so that the material of the pipe is easily deteriorated by hydrolysis or the like. In addition, since the strip-shaped tube fixture contacts the tube with a line instead of a surface, stress on the tube may be concentrated in a place where there is no dent, and the tube may be destroyed.

Patent Document 1 proposes a method of blending a low shrinkage agent as a measure to prevent shrinkage of such a thermosetting resin. The compounding of a low shrinkage agent is expected to have the effect of preventing the occurrence of cracks due to curing shrinkage.
Further, a method of reducing dents caused by shrinkage by laminating a glass fiber surface mat (with a basis weight of ^{about 30 g / m 2) on the outermost layer of the pipe is used.}

Japanese Unexamined Patent Publication No. 7-292231

According to the invention of Patent Document 1, the shrinkage of the resin is reduced by improving the adhesiveness between the matrix resin and the low shrinkage agent. However, since the reinforcing fibers and the low shrinkage agent do not adhere to each other, the effect of suppressing heat shrinkage when the matrix resin is heat-cured is insufficient.
In particular, when a tube is formed by winding a band-shaped bundle of long fiber-like reinforcing fibers by the filament winding method, it is difficult to eliminate the dent caused by the resin-rich portion. In addition, there is a limit to the effect of suppressing heat shrinkage when molding thick-walled products.
Further, even if the glass fiber surface mat is laminated, it is difficult to completely suppress the shrinkage because the tension of the glass fiber surface mat is insufficient with respect to the resin shrinkage force.

The present invention has been made in view of the above circumstances, and provides a new shrinkage countermeasure that can be adopted in place of or in addition to the conventional shrinkage countermeasures using a low shrinkage agent or a glass fiber surface mat. The challenge is to provide.
That is, a resin composition for obtaining a fiber-reinforced resin molded product with reduced shrinkage during curing by a new method, a fiber-reinforced resin molded product using this resin composition, a multilayer tube, and a fiber-reinforced resin molded product. It is an object to provide a manufacturing method of.

In order to achieve the above problems, the present invention has adopted the following configuration.
[1] A resin composition for applying to a fiber-reinforced base material to obtain a fiber-reinforced resin molded product.
Contains thermosetting resin and inorganic filler,
The inorganic filler is a resin composition having a particle size of 0.008 to 0.5 μm and an oil absorption of 50 to 300 mL / 100 g.
[2] The resin composition according to [1], wherein the thermosetting resin is an unsaturated polyester resin.
[3] The resin composition according to [1] or [2], wherein the inorganic filler is silica.
[4] A fiber-reinforced resin molded product containing a fiber-reinforced base material and a cured product of a resin composition applied to the fiber-reinforced base material, wherein the resin composition is any one of [1] to [3]. A fiber-reinforced resin molded product, which is the resin composition according to the item.
[5] The fiber-reinforced resin molded product according to [4], wherein the fiber-reinforced base material is a glass fiber base material.
[6] The fiber-reinforced resin molded product according to [5], which has a tubular structure.
[7] A multilayer tube in which at least a part of the layers is the fiber-reinforced resin molded product according to [5].
[8] A multi-layer pipe including a layer made of the fiber-reinforced resin molded product according to [5] and a resin concrete layer.
[9] A fiber-reinforced resin composed of a bundle of long fibrous reinforcing fibers, which is coated with a resin composition, wound around a core tube or a tube to be reinforced, and then cured of the resin composition. It is a method of manufacturing a molded body.
A method for producing a fiber-reinforced resin molded product, wherein the resin composition is the resin composition according to any one of [1] to [3].

According to the resin composition of the present invention and the method for producing a fiber-reinforced resin molded product, a multilayer tube, and a fiber-reinforced resin molded product using this resin composition, a fiber-reinforced resin molded product having reduced shrinkage during curing and a fiber-reinforced resin molded product. A multi-layer tube can be obtained.

It is sectional drawing which shows the schematic structure of the multilayer tube which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the schematic structure of the multilayer tube which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the schematic structure of the multilayer tube which concerns on 3rd Embodiment of this invention. It is a schematic perspective view which shows the schematic structure of the fiber reinforced base material used in an Example. It is a schematic perspective view which shows the schematic structure of the other fiber reinforced base material used in an Example. It is a perspective view of the type for making evaluation data used for the sample evaluation of an Example. It is a figure which shows the state which the sample to be evaluated is laminated on the mold for making evaluation data. It is a figure explaining how to obtain the shrinkage rate.

[Resin composition]
The resin composition of the present invention is a resin composition for applying to a fiber-reinforced base material to obtain a fiber-reinforced resin molded product.
The resin composition of the present invention contains a thermosetting resin and an inorganic filler.

<Thermosetting resin>
The thermosetting resin is not particularly limited, but one or more selected from the group consisting of unsaturated polyester resin, acrylic resin, epoxy resin and phenol resin is preferable, and the degree of freedom in designing the physical properties after curing is high and the cost is low. Therefore, an unsaturated polyester resin is particularly preferable.
The case where an unsaturated polyester resin is used as the thermosetting resin will be described in detail below.

(Unsaturated polyester resin)
The unsaturated polyester resin is a composition containing an unsaturated polyester (a) and a vinyl monomer (b) as a cross-linking agent.
In order to obtain the unsaturated polyester (a), it is preferable to use saturated dibasic acid (a1), unsaturated dibasic acid (a2), and glycol (a3) as raw materials.

The saturated dibasic acid (a1) is a dibasic acid that does not contain a non-conjugated double bond between carbon atoms in one molecule such as orthophthalic acid, isophthalic acid, terephthalic acid or adipic acid. As the saturated dibasic acid (a1), one type may be used alone or two or more types may be used in combination, if necessary.
The unsaturated dibasic acid (a2) is a dibasic acid containing one or more non-conjugated double bonds between carbon atoms in one molecule such as maleic anhydride or fumaric acid. As the unsaturated dibasic acid (a2), one type may be used alone or two or more types may be used in combination, if necessary.

Glycol (a3) has two hydroxy groups in one molecule such as alkylene glycol such as ethylene glycol or propylene glycol, polyoxyalkylene glycol such as dialkylene glycol or trialkylene glycol, or bisphenol such as bisphenol A or bisphenol F. It is a diol containing. As the glycol (a3), one type may be used alone or two or more types may be used in combination, if necessary.

The unsaturated polyester (a) further has one or two unconjugated double bonds between carbon atoms in one molecule, which is not included in either the unsaturated dibasic acid (a2) and the glycol (a3). The monomer (a4) can be used as a raw material. Examples of such a monomer (a4) include, but are not limited to, styrene, propylene, dicyclopentadiene, (meth) acrylic acid alkyl ester, and the like. As the monomer (a4), one type may be used alone or two or more types may be used in combination, if necessary.

The method for synthesizing the unsaturated polyester (a) is a synthesis in which a saturated dibasic acid (a1), an unsaturated dibasic acid (a2) and a glycol (a) acid, and if desired, a monomer (a4) are simultaneously charged and condensed. There are methods, etc., but are not particularly limited.
The unsaturated polyester resin is an ortho-based unsaturated polyester resin, an iso-based unsaturated polyester resin, a tele-based unsaturated ester resin, or a bis-based unsaturated polyester, depending on the type of saturated dibasic acid (a1) or the type of glycol (a3). It may be classified as a resin.
The polymerizable unsaturated monomer (b) is not particularly limited, and those conventionally used for unsaturated polyester resins can be used.

Examples of the polymerizable unsaturated monomer (b) are styrene, α-methylstyrene, chlorostyrene, dichlorostyrene, divinylbenzene, t-butylstyrene, vinyltoluene, vinyl acetate, diarylphthalate, and triarylsia. Nurate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Lauryl (meth) acrylate, Cyclohexyl (meth) acrylate, benzyl (meth) acrylate, stearyl (meth) acrylate, tridecyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, ethylene glycol monomethyl ether (Meta) acrylate, ethylene glycol monoethyl ether (meth) acrylate, ethylene glycol monobutyl ether (meth) acrylate, ethylene glycol monohexyl ether (meth) acrylate, ethylene glycol mono2-ethylhexyl ether (meth) acrylate, diethylene glycol monomethyl ether ( Meta) acrylate, diethylene glycol monoethyl ether (meth) acrylate, diethylene glycol monobutyl ether (meth) acrylate, diethylene glycol monohexyl ether (meth) acrylate, diethylene glycol mono2-ethylhexyl ether (meth) acrylate, dipropylene glycol monomethyl ether (meth) acrylate , Dipropylene glycol monoethyl ether (meth) acrylate, dipropylene glycol monobutyl ether (meth) acrylate, dipropylene glycol monohexyl ether (meth) acrylate, dipropylene glycol mono2-ethylhexyl ether (meth) acrylate, diethylene glycol di (meth) acrylate. ) Acrylate, Dipropylene glycol di (meth) acrylate, Neopentyl glycol di (meth) acrylate, Polytetramethylene glycol dimethacrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) ) Acrylate, 2-hydroxy-1,3-dimethacryloxypropane, 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxyethoxy) phenyl] propane , 2,2-bi Su [4- (methacryloxypolyethoxy) phenyl] propane, tetraethylene glycol diacrylate, bisphenol A ethylene oxide addition (n = 2) diacrylate, isocyanurate ethylene oxide addition (n = 3) diacrylate and pentaerythritol diacrylate It is monostearate, but is not limited to these.
As the polymerizable unsaturated monomer (b), one type may be used alone or two or more types may be used in combination, if necessary.

The number average molecular weight of the unsaturated polyester (a) is not particularly limited, but is preferably 400 to 1500, more preferably 400 to 1200, and even more preferably 400 to 1000. When the number average molecular weight of the unsaturated polyester (a) is within this range, the fluidity of the unsaturated polyester resin and the like are good, and the moldability is further improved.

The contents of the unsaturated polyester (a) and the polymerizable unsaturated monomer (b) in the unsaturated polyester resin are not particularly limited, but the unsaturated polyester (a) and the polymerizable unsaturated monomer (b) are not particularly limited. ) Is 100 parts by mass, preferably 80 to 60 parts by mass of the unsaturated polyester (a) and the balance of the polymerizable unsaturated monomer (b). Within this range, the shrinkage, physical properties and moldability of the polyester resin become better.
The unsaturated polyester resin may be mixed with a compound other than the compound used for the synthesis of the unsaturated polyester (a) and the polymerizable unsaturated monomer (b) as long as the effects of the present invention are not lost. ..
Examples of commercially available unsaturated polyester resins include iso-based unsaturated polyester resins (manufactured by Japan U-Pica Company).

<Polymerization inhibitor>
The resin composition of the present invention may further contain a polymerization inhibitor.
When the thermosetting resin is an unsaturated polyester resin, the inclusion of a polymerization inhibitor suppresses the reaction between the unsaturated polyester and the polymerizable unsaturated monomer, thus enhancing safety.
The polymerization inhibitor is not particularly limited, and hydroquinone, toluhydroquinone, trimethylhydroquinone, tertiary butyl hydroquinone, diterly butyl hydroquinone, tertiary butyl catechol, methoxyhydroquinone, benzoquinone, tertiary butyl quinone, phenothiazine and the like can be used.
One type of polymerization inhibitor may be used alone, or two or more types may be used in combination.
When the resin composition of the present invention contains a polymerization inhibitor, the content of the polymerization inhibitor is not particularly limited, but is preferably 0.0001 to 0.1 parts by mass with respect to 100 parts by mass of the resin composition.

<Curing agent and curing accelerator>
In order to cure the resin composition of the present invention, it is preferable to add a curing agent and heat the resin composition. Further, a curing accelerator may be used in combination with the curing agent.

(Hardener)
The curing agent is not particularly limited, but an organic peroxide catalyst is preferable, and benzoyl peroxide, dicumyl peroxide, diisopropyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, and 1,1-bis are used. (T-Butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-bis (t-Butylperoxy) Hexin-3,3-Isopropylhydroperoxide, t-Butylhydro Peroxide, dicumyl peroxide, dicumylhydroperoxide, acetyl peroxide, bis (4-t-butylcyclohexyl) peroxydicarbonate, diisopropylperoxydicarbonate, isobutyl peroxide, 3,3,5-trimethylhexa Organic peroxides such as noyl peroxide and lauryl peroxide, and azo polymerization initiators such as azobisisobutyronitrile and azobiscarboxylicamide can be used.
One type of curing agent may be used alone, or two or more types may be used in combination.

The amount of the curing agent added to the resin composition of the present invention is not particularly limited, but is preferably 0.1 to 4 parts by mass, preferably 0.3, based on 100 parts by mass of the resin composition of the present invention. ~ 3 parts by mass is more preferable.
The curing agent is preferably added immediately before the resin composition of the present invention is applied to the fiber-reinforced base material. A fiber-reinforced resin molded product can be obtained by heating and curing the resin composition of the present invention together with a fiber-reinforced base material.

(Curing accelerator)
The curing accelerator is not particularly limited, but is a metal soap such as vanadyl octate, copper naphthenate, barium naphthenate, cobalt naphthenate and cobalt octate, Li ₃ [Co (NO ₂ ) ₆ ], Li ₃ [Co ( NO ₂ ) ₅ Cl], Li ₃ [Co (NO ₂ ) ₅ Br], Li ₃ [Co (NO ₂ ) ₄ Cl ₂ ], Li ₃ [Co (NO ₂ ) ₄ Br ₂ ], Na ₃ [Co ( NO ₂ ) ₆ ], Na ₃ [Co (NO ₂ ) ₅ Cl], Na ₃ [Co (NO ₂ ) ₅ Br], Na ₃ [Co (NO ₂ ) ₄ Cl ₂ ], Na ₃ [Co (NO ₂₎ ) ₄ Br ₂ ], K ₃ [Co (NO ₂ ) ₆ ], K ₃ [Co (NO ₂ ) ₅ Cl], K ₃ [Co (NO ₂ ) ₅ Br], K ₃ [Co (NO ₂ ) ₄ Cobalt compounds such as Cl ₂ ] and K ₃ [Co (NO ₂ ) ₄ Br ₂ ], metal chelate compounds such as vanadylacetyl acetate, cobalt acetylacetate and iron acetylacetonate, and N, N-dimethylamino-p-benzaldehyde. , N, N-dimethylaniline, N, N-diethylaniline, methylhydroxyethylaniline, N, N-dimethyl-p-toluidine, N, N-bis (2-hydroxyethyl) -p-toluidine, 4-N, N-Dimethylaminobenzaldehyde, 4-N, N-bis (2-hydroxyethyl) aminobenzaldehyde, 4-methylhydroxyethylaminobenzaldehyde, N, N-bis (2-hydroxypropyl) -p-toluidine, N-ethyl- Amines such as m-toluidine, triethanolamine, m-toluidine, diethylenetriamine, pyridine, phenylmorpholin, piperidine and diethanolaniline can be used.
One type of curing accelerator may be used alone, or two or more types may be used in combination.

When the resin composition of the present invention contains a curing accelerator, the content of the curing accelerator is not particularly limited, but is preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of the resin composition of the present invention. ..
The curing accelerator may be added before the curing agent is added to the resin composition of the present invention, or may be added to the resin composition at the same time as the curing agent.

<Inorganic filler>
The resin composition of the present invention contains an inorganic filler having a particle size of 0.008 to 0.5 μm.
The particle size is the primary average particle size measured by a light-transmitting centrifugal sedimentation type particle size distribution measuring device.
The particle size of the inorganic filler is preferably 0.008 to 0.2 μm, more preferably 0.008 to 0.06 μm.
When the particle size of the inorganic filler is not more than the upper limit of the above range, it can be satisfactorily dispersed in the resin composition. Further, when it is applied to the fiber reinforced base material, it can be filled in the fiber reinforced base material at a high density together with other components such as a thermosetting resin. Further, when the particle size is not more than the upper limit of the above range, the oil absorption tends to be high.

The inorganic filler in the resin composition of the present invention has an oil absorption amount of 50 to 300 mL / 100 g.
The oil absorption is a value measured according to DIN ISO 787 part 5.
The oil absorption is preferably 100 to 300 mL / 100 g.
When the oil absorption amount of the inorganic filler is at least the lower limit of the above range, good adhesion to the thermosetting resin can be obtained.
When the amount of oil absorbed by the inorganic filler is not more than the upper limit of the above range, it is possible to suppress a decrease in moldability due to an increase in the viscosity of the resin composition.

The intermolecular distance of the thermosetting resin is shortened at the time of curing, but the presence of the inorganic filler can inhibit the contraction of the intermolecular distance of the thermosetting resin.
In the present invention, the inorganic filler having a small particle size can be uniformly present in the thermosetting resin at a high density. Further, the inorganic filler having a large oil absorption is excellent in adhesion to the thermosetting resin. Therefore, the resin composition of the present invention containing a specific inorganic filler has a small shrinkage during the effect.

Examples of the inorganic filler satisfying the above-mentioned particle size and oil absorption amount include silica having an oil absorption amount of 100 to 300 mL / 100 g. The silica may be silica contained in Neuburg Siricious Earth, which is referred to by the trade name of silitin or silicoloid.
As the inorganic filler satisfying the above-mentioned particle size and oil absorption amount, one type may be used alone, or two or more types may be used in combination.

Examples of commercially available silica products include Aerosil (registered trademark) manufactured by Nippon Aerosil Co., Ltd. and Sunsphere manufactured by AGC Co., Ltd.
Neuburg Silish Earth is a natural bond consisting of spherically microcrystalline, amorphous silica and plate-like kaolinite. The two minerals are loosely bonded to each other, but cannot be separated by physical methods. Due to its natural formation, its silica portion is round in shape, and its primary particles are a collection of microcrystalline (grape tufts) with a particle size of about 200 nm, which is amorphous silica like opal. It is covered. The siricolloid is a silane-treated surface of citrine.

The resin composition of the present invention preferably contains 0.05 to 5 parts by mass of an inorganic filler satisfying the above-mentioned specific particle size and oil absorption amount, when the total amount of the resin composition is 100 parts by mass. It is more preferably contained in an amount of 5 to 5 parts by mass, and further preferably contained in an amount of 1 to 4 parts by mass.
By including the inorganic filler satisfying the above-mentioned specific particle size and oil absorption amount at least the lower limit value in the above range, the shrinkage suppressing effect at the time of curing of the resin composition is enhanced. Further, since the resin composition is thickened, molding while rotating is facilitated as in filament winding molding. Furthermore, since thixotropy can be imparted, it does not prevent the resin composition from being applied to the fiber-reinforced base material.
By including the inorganic filler that satisfies the above-mentioned specific particle size and oil absorption amount at least the upper limit of the above range, it is possible to suppress a decrease in moldability due to an increase in the viscosity of the resin composition.

The resin composition of the present invention may contain other inorganic fillers that do not meet the above-mentioned specific particle size and oil absorption requirements.
Other inorganic fillers include calcium carbonate, kaolinite, halloysite, talc and titanium oxide.

When the resin composition of the present invention contains an inorganic filler that does not satisfy the above-mentioned specific particle size and oil absorption conditions, the content thereof shall be 8 parts by mass or less when the entire resin composition is 100 parts by mass. Is preferable, and 5 parts by mass or less is more preferable.
If the content of the inorganic filler that does not satisfy the above-mentioned specific particle size and oil absorption conditions is not more than the above upper limit value, the effect of the present invention is not impaired.
As the inorganic filler that does not satisfy the above-mentioned specific particle size and oil absorption conditions, one type may be used alone, or two or more types may be used in combination.

<Other ingredients>
In addition to the above-mentioned components, a thickener, an antioxidant, a plasticizer, a flame retardant, a stabilizer, a rock denaturing agent, a mold release agent, an antioxidant, and ultraviolet absorption, as long as the effects of the present invention are not impaired. It may contain various additives such as an agent, an impregnating agent and a defoaming agent. One type of these additives may be used alone, or two or more types may be used in combination.

<Manufacturing method of resin composition>
The method for producing the resin composition of the present invention is not particularly limited, and examples thereof include the following methods.
First, the unsaturated polyester resin is mixed with an inorganic filler and kneaded using a mixer. Further, the curing agent, the curing agent, and other components are mixed as necessary and kneaded well.
Various deformations are possible, such as adding a curing accelerator and a curing agent immediately before the production of the cured product.

[Fiber reinforced base material]
The fiber-reinforced base material is a base material composed of reinforcing fibers. As the reinforcing fiber, for example, glass fiber, carbon fiber, mineral fiber, synthetic fiber and the like can be used.
Among these, glass fiber is particularly preferable because of its high tensile strength and low cost. That is, the fiber-reinforced base material is preferably a glass fiber base material.
The reinforcing fiber may be a single fiber, a fiber bundle (strand) in which the single fiber is bundled, or a chopped strand in which the fiber bundle is cut.

The fiber-reinforced base material may be a woven fabric of reinforcing fibers or a non-woven fabric. Examples of the woven fabric include a roving yarn in which long glass fibers are bundled with nylon or the like, and a roving cloth in which roving is woven vertically and horizontally.
Examples of the non-woven fabric include a glass mat obtained by hardening single fibers and chopped strands with glue.
Moreover, you may use one kind or a plurality of kinds of fiber-reinforced base materials in a plurality of layers.

[Fiber reinforced plastic molded product]
The fiber-reinforced resin molded body of the present invention is a molded body containing a fiber-reinforced base material and a cured product of the resin composition of the present invention applied to the fiber-reinforced base material.
The method for producing the fiber-reinforced resin molded product of the present invention is not particularly limited, and for example, a filament winding method can be adopted.

In the filament winding method, a resin composition is applied to a core tube or a heterogeneous tube to be reinforced, which is sent at a constant speed while rotating, with a fiber-reinforced base material composed of a bundle of a plurality of long fibrous reinforcing fibers. It is a method in which one layer or a plurality of layers of fiber-reinforced base material is wound and then cured by feeding out in a strip shape. If the core tube is wound around the core tube instead of the different type of tube to be reinforced, the core tube is removed after curing.
As a winding method, there are hoop winding in which the fiber is wound orthogonal to the rotation axis of the core tube or a different type of tube to be reinforced, and helical winding in which the fiber is wound while maintaining the fiber at a specific angle with respect to the rotation axis.
The filament winding method is preferable in that the effect of applying the present invention can be easily obtained.
Other manufacturing methods include a compression molding method in which a required number of fiber-reinforced base materials coated with a resin composition are laminated and heat and pressure are applied by a pressed steel plate to cure the fiber-reinforced base material into a desired shape, an injection molding method, and a centrifugal molding. The method may be adopted.

The curing temperature is not particularly limited, but is preferably 50 ° C. or higher, more preferably 50 to 60 ° C., still more preferably 55 to 65 ° C.
The curing time is also not particularly limited, but is preferably 6 hours or more, more preferably 12 hours or more, and even more preferably 24 to 48 hours.

The shape of the fiber-reinforced resin molded product of the present invention is not particularly limited, but it is preferable that the fiber-reinforced resin molded product has a tubular structure in that the effect of applying the present invention can be easily obtained.
Examples of the shape of the fiber-reinforced resin molded product of the present invention include a pipe structure, a plate-shaped body, and a continuous body having a U-shaped or V-shaped cross section such as a rain gutter.

[Multi-layer tube]
The multilayer tube of the present invention is a multilayer tube in which at least a part of the layers is composed of the fiber-reinforced resin molded product of the present invention.
Specific examples of the multilayer tube will be shown below as the first embodiment, the second embodiment, and the third embodiment, but the multilayer tube of the present invention is not limited to these embodiments.

<First Embodiment>
FIG. 1 is an FRP tube 10 according to the first embodiment of the multilayer tube of the present invention. The FRP tube 10 has an annular or cylindrical FRP layer 11 and an outer peripheral protective layer 12 located on the outer peripheral surface thereof.
In the FRP tube 10, the FRP layer 11 and the outer peripheral protective layer 12 are both fiber-reinforced resin molded products of the present invention. That is, the FRP tube 10 is a multi-layer tube in which all layers are made of the fiber-reinforced resin molded product of the present invention.

The FRP tube 10 is a glass fiber reinforced group composed of a bundle of long fibrous glass reinforcing fibers coated with a strip-shaped resin composition of the present invention to be an FRP layer 11 on a core tube by a filament winding method. It can be manufactured by sequentially winding the material) and the glass fiber surface mat to be the outer peripheral protective layer 12, curing the material, and then removing the core tube.
The glass roving to be the FRP layer 11 is preferably wound in a plurality of layers.
As the glass fiber surface mat to be the outer peripheral protective layer 12, it is preferable to use a very thin fiber-reinforced base material having ^{a basis weight of about 30 g / m 2.}

As the glass fiber surface mat, one to which the resin composition of the present invention is not applied is used, but the resin composition of the present invention applied to the glass roving by winding it on the glass roving to be the FRP layer 11 is used. Things soak in. Therefore, when the winding is completed, the glass fiber surface mat is in a state where the resin composition of the present invention is applied.
By changing the size of the core tube, FRP tubes 10 having various diameters can be obtained.

<Second Embodiment>
FIG. 2 is an FRP reinforcing pipe 15 according to a second embodiment of the multilayer pipe of the present invention. The FRP reinforcing pipe 15 has an annular or cylindrical different type pipe 13 and an FRP layer 11 and an outer peripheral protective layer 12 sequentially laminated on the outer peripheral surface thereof.
The FRP reinforcing pipe 15 of the present embodiment is a multi-layer pipe in which a different type of pipe 13 is reinforced by an FRP layer 11 and an outer peripheral protective layer 12 which are fiber reinforced resin molded bodies of the present invention.

Examples of the dissimilar pipe 13 include thermoplastic resin pipes such as polyvinyl chloride, polypropylene, and polyethylene, steel pipes, and cast iron pipes.
The FRP layer 11 and the outer peripheral protective layer 12 are the same as those in the first embodiment.
The FRP reinforcing pipe 15 can be manufactured by sequentially winding a glass roving to be the FRP layer 11 and a glass fiber surface mat to be the outer peripheral protective layer 12 around a different type of pipe 13 by a filament winding method and curing the FRP reinforcing pipe 15.

<Third Embodiment>
FIG. 3 is a multilayer tube 1 according to a third embodiment of the multilayer tube of the present invention. The multilayer pipe 1 includes a tubular resin concrete layer 4, an inner surface FRP layer 3 located on the inner peripheral surface of the resin concrete layer 4, an outer surface FRP layer 5 located on the outer peripheral surface of the resin concrete layer 4, and an inner surface FRP layer. It has an inner surface protective layer 2 located on the inner peripheral surface of No. 3 and an outer surface protective layer 6 located on the outer periphery of the outer surface FRP layer 5.
That is, in the multilayer pipe 1, the inner surface protective layer 2, the inner surface FRP layer 3, the resin concrete layer 4, the outer surface FRP layer 5 and the outer surface protective layer 6 are located in this order from the inner peripheral side.
Either one of the inner surface FRP layer 3 and the outer surface FRP layer 5 may be provided, but it is preferable to have both of them because the bending strength of the multilayer tube 1 is improved.

The resin concrete layer 4 serves as a base pipe of the multilayer pipe 1 and is made of a cured product of the resin concrete composition. Since the cured resin concrete has high compressive strength but relatively low tensile strength, it is reinforced by the inner surface FRP layer 3 and the outer surface FRP layer 5.
The resin concrete composition is a composition containing a resin composition as a binder and an aggregate.
The resin composition of the resin concrete composition is preferably the same as the resin composition of the present invention.

The aggregate is not particularly limited as long as it is conventionally blended in the resin concrete composition, but at least one selected from the group consisting of silica sand, crushed stone, gravel, blast furnace slag aggregate and artificial lightweight aggregate is preferable. , Silica sand is particularly preferable.
The particle size of the aggregate is not particularly limited, but is preferably 5 mm or less, more preferably 0.1 to 3 mm, still more preferably 0.1 to 1.5 mm. The particle size of the aggregate is measured in accordance with JIS Z 2601: 1993 "Test method for foundry sand".
The content of the aggregate in the resin concrete composition is not particularly limited, but is preferably 100 to 2000 parts by mass with respect to 100 parts by mass of the thermosetting resin.

The inner surface FRP layer 3 improves the strength of the multilayer tube 1, and is made of the fiber-reinforced resin molded product of the present invention.
The inner surface FRP layer 3 may be a laminate of a plurality of FRP layers having different directions of reinforcing fibers. In the multilayer tube 1 shown in FIG. 3, the inner surface FRP layer 3 has the inner surface FRP layer (circumferential direction) 3a in which the direction of the reinforcing fibers is aligned with the circumferential direction of the multilayer tube 1 and the direction of the reinforcing fibers in the axial direction of the multilayer tube 1. Two layers with the combined inner surface FRP layer (axial direction) 3b are laminated. In the multilayer tube 1 shown in FIG. 3, the inner surface FRP layer (circumferential direction) 3a is located on the inner peripheral side of the inner surface FRP layer (axial direction) 3b, but the opposite may be true.

At the interface between the resin concrete layer 4 and the inner surface FRP layer 3, it is preferable that at least one selected from the group consisting of bulky roving and three-dimensional woven fabric is arranged. In bulky roving and three-dimensional woven fabrics, the reinforcing fibers have a three-dimensional orientation, so that the reinforcing fibers enter the resin concrete layer 4 and the inner surface FRP layer 3 at the time of manufacturing the multilayer pipe 1. As a result, the anchor effect is exhibited, and the resin concrete layer 4 and the inner surface FRP layer 3 are more firmly bonded to each other.

The outer surface FRP layer 5 improves the strength of the multilayer tube 1 like the inner surface FRP layer 3 described above, and is made of the fiber reinforced resin molded body of the present invention.
The outer surface FRP layer 5 may be a laminate of a plurality of FRP layers having different directions of reinforcing fibers. In the multilayer tube 1 shown in FIG. 5, the outer surface FRP layer 5 has the outer surface FRP layer (axial direction) 5a in which the direction of the reinforcing fibers is aligned with the axial direction of the multilayer tube 1 and the direction of the reinforcing fibers in the circumferential direction of the multilayer tube 1. Two layers with the combined outer surface FRP layer (circumferential direction) 5b are laminated. In the multilayer tube 1 shown in FIG. 5, the outer surface FRP layer (axial direction) 5a is located on the inner peripheral side of the outer surface FRP layer (circumferential direction) 5b, but the opposite may be true.

At the interface between the resin concrete layer 4 and the outer surface FRP layer 5, at least one selected from the group consisting of bulky roving and three-dimensional woven fabric is preferably arranged. In bulky roving and three-dimensional woven fabrics, the reinforcing fibers have a three-dimensional orientation, so that the reinforcing fibers enter the resin concrete layer 4 and the outer surface FRP layer 5 during the production of the multilayer pipe 1. As a result, the anchor effect is exhibited, and the resin concrete layer 4 and the outer surface FRP layer 5 are more firmly bonded to each other.

When there is an inner surface protective layer 2, the inner surface protective layer 2 prevents direct contact between the inner surface FRP layer 3 and the liquid passing through the multilayer tube 1. It suppresses the erosion of the inner surface FRP layer 3 by the liquid and prevents the elution of the chemical substance from the inner surface FRP layer 3 into the liquid.
In the absence of the inner surface FRP layer 3, the inner surface protective layer 2 prevents direct contact between the resin concrete layer 4 and the liquid passing through the multilayer pipe 1. It suppresses the erosion of the resin concrete layer 4 by the liquid and prevents the elution of chemical substances from the resin concrete layer 4 into the liquid.
The inner protective layer 2 may be omitted, but it is better to have it. It is possible to improve the durability of the multilayer tube 1 and prevent contamination of the liquid passing through the multilayer tube 1.

The inner surface protective layer 2 is preferably made of a synthetic resin or an elastomer.
The synthetic resin or elastomer is, for example, an unsaturated polyester resin, an epoxy resin, an acrylic resin, a thermoplastic resin such as a phenol resin, a thermoplastic resin such as polyethylene, polyolefin or polyvinyl chloride, a natural rubber, a styrene butadiene rubber or a chloroprene rubber. Such as rubber or thermoplastic elastomer, a thermocurable resin or a thermoplastic resin is preferable, and a thermocurable resin is more preferable. As the thermosetting resin, a low-cost polyester resin, an epoxy resin having excellent corrosion resistance, an acrylic resin having excellent weather resistance, or a phenol resin having heat resistance and flame retardancy are preferable. Further, the synthetic resin or elastomer constituting the inner surface protective layer 2 is a filler such as carbon black, graphite powder, calcium carbonate or silica, which can be used in combination with the synthetic resin or elastomer, a mold release agent, an ultraviolet absorber, and the like. Additives such as pigments, thickeners, antioxidants, plasticizers, flame retardants or stabilizers may be included.

When there is an outer surface protective layer 6, the outer surface protective layer 6 prevents direct contact between the outer surface FRP layer 5 and the liquid existing outside the multilayer tube 1. It suppresses the erosion of the outer surface FRP layer 5 by the liquid and prevents the elution of the chemical substance from the outer surface FRP layer 5 into the liquid.
In the absence of the outer FRP layer 5, the outer protective layer 6 prevents direct contact between the resin concrete layer 4 and the liquid existing outside the multilayer pipe 1. It suppresses the erosion of the resin concrete layer 4 by the liquid and prevents the elution of chemical substances from the resin concrete layer 4 into the liquid.
The outer protective layer 6 may be omitted, but it is better to have it. It is possible to improve the durability of the multilayer tube 1 and prevent contamination of the liquid existing outside the multilayer tube 1.

The outer surface protective layer 6 is preferably made of a synthetic resin or an elastomer.
The synthetic resin or elastomer is the same as that of the inner surface protective layer 2.

The method for producing the multilayer tube 1 is not particularly limited, but a filament winding method is preferable.
Specifically, for a core tube that is sent at a constant speed while rotating, at least one selected from the group consisting of an inner surface protective layer 2, an inner surface FRP layer 3, bulky roving and a three-dimensional woven fabric, a resin concrete layer 4 , At least one selected from the group consisting of bulky roving and three-dimensional woven fabric, the material of the outer surface FRP layer 5 and the outer surface protective layer 6 is wound in sequence, heated in sequence, and the thermosetting resin is cured to continuously form a multilayer tube. It is preferable to manufacture the concrete.
By changing the size of the core tube, a multilayer tube 1 having various diameters can be manufactured.

Examples of the method for producing the multilayer tube 1 include the method for producing a fiber reinforced plastic composite tube described in JP-A-2001-205711, Japanese Patent Application Laid-Open No. 2001-205712, and Japanese Patent Application Laid-Open No. 2001-205712. The method for producing a fiber reinforced plastic composite tube described in [0028] or the method for producing a fiber reinforced plastic composite tube described in [0009] to [0019] of JP-A-10-193467 may be adopted.

[Preparation of fiber reinforced base material]
A layer of a glass roving layer (x direction) 22 was sandwiched between a pair of glass mats 21 to form a fiber reinforced base material 20A shown in FIG.
As the glass mat 21, a chopped strand mat manufactured by Nitto Boseki Co., Ltd. (a non-woven fabric obtained by hardening chopped strands with glue) was used.
As the glass roving layer (x direction) 22, Advantex T30 manufactured by Owens Corning (Roving yarn in which 1200 TEX glass rovings were arranged in the x direction and fixed with nylon yarn) was used.

Further, a glass roving layer (x direction) 22 and a glass roving layer (y direction) 23 were sandwiched between the pair of glass mats 21 to form a fiber reinforced base material 20B shown in FIG.
The glass mat 21 and the glass roving layer (x direction) 22 are the same as those used for the fiber reinforced base material 20A.
As the glass roving layer (y direction) 23, the same one as the glass roving layer (x direction) 22 was used. However, the orientation direction of the glass roving was arranged so as to be the y direction orthogonal to the x direction.

[Making a mold for creating evaluation materials]
Aggregate (silica sand No. 7 and No. 3 mixed at a blending ratio of 2: 1) and unsaturated polyester resin (4007A manufactured by Japan U-Pica Company) were mixed at a mass ratio of 85:15 and filled in a square mold.
The surface was flattened, an iron rod having a diameter of 4 mm was placed in the center, and a load was applied from above to subside about 2 mm. After curing in that state, the iron rod was removed to prepare a mold 30 for creating evaluation data having a recessed groove 30a having a depth of about 2 mm (FIG. 6).

[Example 1]
To 100 parts by mass of unsaturated polyester resin (4007A manufactured by Japan U-Pica Company), 4 parts by mass of Aerosil manufactured by Nippon Aerosil Co., Ltd., model number RY200S (grain size 12 nm) was added to obtain the resin composition (1). The fiber-reinforced base material 20A was impregnated with the resin composition (1) to obtain a resin-impregnated base material 40 coated with the resin composition (1).

A small amount of the resin composition (1) was poured into 30a of the evaluation data preparation mold 30, and then the obtained resin-impregnated base material 40 was superposed on the evaluation data preparation mold 30 as shown in FIG.
The resin-impregnated base material 40 was stacked on the evaluation data preparation mold 30 so that the x direction was along the longitudinal direction of the concave groove 30a.

The concave groove 30a of the evaluation data preparation mold 30 is filled with the resin composition (1) poured in advance and the resin composition (1) dripping from the resin-impregnated base material 40, and is a simulated resin-rich portion. A resin convex portion 40a was formed.
Then, the resin-impregnated base material 40 was cured by heating at 60 ° C. for 120 minutes. The cured product 45 of the resin-impregnated base material 40 was formed with a cured convex portion 45a in which the resin convex portion 40a was cured.

The shrinkage rate due to curing was determined as follows.
First, a to c shown in FIG. 8A were measured using calipers. a and c are the thicknesses of the evaluation data creation mold 30 on both outer sides of the concave groove 30a. b is the thickness of the evaluation data preparation mold 30 in the deepest portion of the concave groove 30a.
Further, after the resin-impregnated base material 40 was cured, d to f shown in FIG. 8B were measured with respect to the cured product 45 removed from the evaluation data preparation mold 30 using a microscope. d and f are the thicknesses of the cured product 45 on both outer sides of the cured convex portion 45a. e is the thickness of the cured product 45 at the highest portion of the cured convex portion 45a.

Using the numerical values a to f, the shrinkage rate R was determined based on the following formula.
In the following formula, X is the depth of the concave groove 30a, Y is the thickness of the resin-impregnated base material 40 at the highest portion of the resin convex portion 40a before curing, and Z is the curing at the highest portion of the cured convex portion 45a. It is the thickness of the object 45.
X = (a + c) /2-b
Y = (d + f) / 2 + X = (d + f) / 2 + (a + c) / 2-b
Z = e
R (%) = (1-Z / Y) x 100

[Example 2]
To 100 parts by mass of unsaturated polyester resin (4007A manufactured by Japan U-Pica Company), 4 parts by mass of serial colloid (containing silica having a particle size of 200 nm and an oil absorption of 55 mL / 100 g) manufactured by HOFFMANN MINERAL was added to the resin composition (2). ).
A resin-impregnated base material 40 and a cured product 45 were obtained in the same manner as in Example 1 except that the resin composition (2) was used instead of the resin composition (1), and shrinkage was performed in the same manner as in Example 1. The rate R was calculated.

[Comparative Example 1]
An unsaturated polyester resin (4007A manufactured by Japan U-Pica Company) to which no additive was added was used as the resin composition (3).
A resin-impregnated base material 40 and a cured product 45 were obtained in the same manner as in Example 1 except that the resin composition (3) was used instead of the resin composition (1), and shrinkage was performed in the same manner as in Example 1. The rate R was calculated.

[Comparative Example 2]
The resin-impregnated base material 40 was used in the same manner as in Example 1 except that the resin composition (3) was used instead of the resin composition (1) and the fiber-reinforced base material 20B was used instead of the fiber-reinforced base material 20A. And the cured product 45 were obtained, and the shrinkage ratio R was determined in the same manner as in Example 1.

[Comparative Example 3]
To 100 parts by mass of unsaturated polyester resin (4007A manufactured by Japan U-Pica Company), 4 parts by mass of chopped strands manufactured by Nitto Boseki Co., Ltd. (glass chopped strands having a length of 6 mm and a filament diameter of 10 μm) are added to form a resin composition ( 4).
A resin-impregnated base material 40 and a cured product 45 were obtained in the same manner as in Example 1 except that the resin composition (4) was used instead of the resin composition (1), and shrinkage was performed in the same manner as in Example 1. The rate R was calculated.

[Comparative Example 4]
To 100 parts by mass of an unsaturated polyester resin (4007A manufactured by Japan U-Pica Company), 15 parts by mass of a low shrinkage agent (styrene-vinyl acetate block copolymer) manufactured by NOF Corporation was added to obtain a resin composition (5).
A resin-impregnated base material 40 and a cured product 45 were obtained in the same manner as in Example 1 except that the resin composition (5) was used instead of the resin composition (1), and shrinkage was performed in the same manner as in Example 1. The rate R was calculated.

Table 1 shows the shrinkage rates of each example and comparative example.
As shown in Table 1, the shrinkage rate of Examples 1 and 2 was less than half of the shrinkage rate of Comparative Example 1 to which the inorganic fine particles were not added.
Further, in Comparative Example 2, although the inorganic fine particles were not added, the fiber-reinforced base material 20B, which was one layer more than the fiber-reinforced base material 20A of Example 1, was used to enhance the reinforcing power of the fibers. However, the shrinkage rate of Examples 1 and 2 was still lower than that of Comparative Example 2.
Further, Comparative Example 3 to which the chopped strand was added showed a slight shrinkage suppressing effect as compared with Comparative Example 1.

Since the fiber-containing resin molded product of the present invention has excellent smoothness, it can be used as a member used in an environment where compressive stress is applied. The fiber-reinforced resin molded body and the multi-layer pipe having the pipe structure of the present invention are supported by a support such as a power cable protection pipe laid aerial in the underground cave, and a bending load is applied to the support point. It is suitable for pipes and outdoor pipes for hydroelectric power plants and the like.

1 Multi-layer pipe 2 Inner surface protective layer 3 Inner surface FRP layer 3a Inner surface FRP layer (circumferential direction)
3b Inner surface FRP layer (axial direction)
4 Resin concrete layer 5 Outer surface FRP layer 5a Outer surface FRP layer (axial direction)
5b Outer surface FRP layer (circumferential direction)
6 Outer surface protective layer 10 FRP tube 11 FRP layer 12 Outer peripheral protective layer 13 Heterogeneous tube 15 FRP reinforcing tube 20A Fiber reinforced base material 20B Fiber reinforced base material 21 Glass mat 22 Glass roving layer (x direction)
23 Glass roving layer (y direction)
30 Mold for creating evaluation data 30a Concave groove 40 Resin impregnated base material 40a Resin convex part 45 Hardened product 45a Hardened convex part

Claims (9)

A resin composition for applying to a fiber-reinforced base material to obtain a fiber-reinforced resin molded product.
Contains thermosetting resin and inorganic filler,
The inorganic filler is a resin composition having a particle size of 0.008 to 0.5 μm and an oil absorption of 50 to 300 mL / 100 g. The resin composition according to claim 1, wherein the thermosetting resin is an unsaturated polyester resin. The resin composition according to claim 1 or 2, wherein the inorganic filler is silica. A fiber-reinforced resin molded product containing a fiber-reinforced base material and a cured product of a resin composition applied to the fiber-reinforced base material, wherein the resin composition is the resin according to any one of claims 1 to 3. A fiber-reinforced resin molded product that is a composition. The fiber-reinforced resin molded body according to claim 4, wherein the fiber-reinforced base material is a glass fiber base material. The fiber-reinforced resin molded product according to claim 5, which has a tubular structure. A multilayer tube in which at least a part of the layers is the fiber-reinforced resin molded product according to claim 5. A multi-layer pipe including a layer made of the fiber-reinforced resin molded product according to claim 5 and a resin concrete layer. A fiber-reinforced resin molded body composed of a bundle of long fibrous reinforcing fibers, which is coated with a resin composition, wound around a core tube or a tube to be reinforced, and then cured of the resin composition. It ’s a manufacturing method,
A method for producing a fiber-reinforced resin molded product, wherein the resin composition is the resin composition according to any one of claims 1 to 3.

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