Fiber material, curable material, cured product, and laminate

Abstract

[Problem] To provide a fiber material or the like which is excellent in handleability and contributes to improvement of strength of a structure to be obtained. [Solution] According to one embodiment of the present invention, a matte-shaped fiber material containing a nonwoven fabric is provided. On a first surface of the fiber material in the fiber material, there is a notch extending from the first surface to the inside of the fiber material. The fiber material has a needle punch mark that penetrates the fiber material.

Description

Fiber materials, curable materials, cured products, and laminates

[0001] The present invention relates to a fiber material, a curable material, a cured product, and a laminate.

[0002] Conventionally, a method of using a core material to obtain a structure including fiber reinforced plastics (FRP) has been known (see, for example, Patent Document 1). The use of such a core material can contribute to weight reduction when obtaining a structure.

[0003] Japanese Patent Application Laid-Open No. 2008-230235

[0004] Incidentally, it is important for the core material described above to be both easy to handle and have the ability to contribute to improving the strength of the resulting structure.

[0005] In view of the above circumstances, the present invention provides a fiber material and the like that is easy to handle and contributes to improving the strength of the resulting structure.

[0006] According to one aspect of the present invention, there is provided a mat-shaped fibrous material including a nonwoven fabric, the mat-shaped fibrous material having a first surface with a notch extending from the first surface to the interior of the mat-shaped fibrous material, and the mat-shaped fibrous material having needle-punched marks penetrating the mat-shaped fibrous material.

[0007] According to the above aspect, a fiber material or the like is provided that is easy to handle and contributes to improving the strength of the resulting structure.

[0008] 1 is a cross-sectional view schematically showing a fiber material 10A of the present embodiment; 2 is a plan view schematically showing a fiber material 10A of the present embodiment; 3 is a cross-sectional view showing a laminate 100 to which the fiber material 10A is applied; 4 is a plan view showing a modified example of the fiber material; 5 is a photograph showing a fiber material of an example; and 6 is a photograph showing a comparison between fiber materials of an example and a comparative example.

[0009] Hereinafter, embodiments of the present invention will be described. Note that the various features shown in the following embodiments can be combined with each other. In addition, in this specification, "(meth)acrylate" represents a concept that includes both "acrylate" and "methacrylate". In addition, in this specification, "(meth)acrylic acid" represents a concept that includes both "acrylic acid" and "methacrylic acid". In addition, in this specification, "to" represents from above to below unless otherwise specified.

[0010] [Fiber Material] First, the fiber material of this embodiment will be described.

[0011] The fibrous material of this embodiment is as follows: A mat-shaped fibrous material including a nonwoven fabric, wherein a first surface of the fibrous material has a notch extending from the first surface to the interior of the fibrous material, and the fibrous material has needle punch marks penetrating the fibrous material.

[0012] The fiber material of this embodiment is, for example, a mat-shaped fiber material that is impregnated with a curable composition described below. Fig. 1 is a cross-sectional view that schematically shows a fiber material 10A of this embodiment.

[0013] Furthermore, the fibrous material 10A of this embodiment is characterized in that a first surface (the surface shown at the top in FIG. 1 ) of the fibrous material 10A has a notch 3 extending from the first surface to the interior of the fibrous material 10A. Furthermore, the fibrous material 10A of this embodiment has needle-punched marks 2 penetrating the fibrous material 10A.

[0014] The thickness of the fiber material 10A may be set as appropriate. However, from the viewpoint of further improving the handling property, the average thickness T ０ may be in the range of 0.5 to 10 mm, may be in the range of 0.7 to 8 mm, or may be in the range of 1 to 7 mm.

[0015] Furthermore, the fiber material 10A has the notches 3 as described above, but the average thickness T ０ Average depth T of notch 3 １ The ratio T １ / T ０may be in the range of 0.1 to 0.99, may be in the range of 0.3 to 0.97, or may be in the range of 0.5 to 0.95. By setting it in such a range, it becomes easier to achieve a balance between the handleability and the mechanical strength of the fiber material 10A.

[0016] FIG. 2 is a plan view schematically illustrating a fibrous material 10A according to this embodiment. This view shows the fibrous material 10A as viewed from the first surface. As described above, the fibrous material 10A includes needle-punched marks 2 and notches 3. In the fibrous material 10A shown in FIG. 2, a plurality of notches 3 are provided on the first surface so as to be substantially parallel to one another. However, as will be described later, the arrangement of the notches 3 is not limited to that shown in FIG. 2.

[0017] 2, the needle punch marks 2 are arranged at equal intervals, but this is not limiting and the needle punch marks 2 may be arranged at random intervals. The needle punch marks 2 result from the needle punching process performed on the nonwoven fabric 1, and the nonwoven fabric used may be one of the following:

[0018] That is, the nonwoven fabric 1 used in this embodiment has needle-punched marks 2 and is also called a "needle-punched nonwoven fabric." The fibers constituting this nonwoven fabric 1 may be polyolefin resins such as polypropylene (PP) fibers; polyester fibers such as polyethylene terephthalate (PET); or synthetic resins such as nylon fibers. The fibers constituting the nonwoven fabric 1 may also be natural fibers such as cotton or hemp, or any other fibers such as carbon fibers.

[0019] The number (density) of needle punch marks 2 in the nonwoven fabric 1 can be set as appropriate. For example, for a 10 cm x 10 cm nonwoven fabric 1, it is preferable to use a nonwoven fabric 1 having 10 to 500 needle punch marks 2, more preferably a nonwoven fabric 1 having 20 to 300 needle punch marks 2, and even more preferably a nonwoven fabric 1 having 50 to 200 needle punch marks 2. By setting the number within such a range, the fiber material is more likely to exhibit better mechanical properties.

[0020] The shape of the needle punch marks 2 can be set as appropriate, but is typically circular. When the needle punch marks 2 are circular, their diameter is preferably in the range of 0.1 mm to 5 mm, more preferably in the range of 0.2 mm to 3 mm, and even more preferably in the range of 0.3 mm to 2 mm. Setting the diameter in such a range makes it easier for the fiber material to exhibit better mechanical properties. Note that the diameter here is the average value for all of the needle punch marks 2 present throughout the nonwoven fabric 1.

[0021] 1 and 2, the fiber material 10A may contain microballoons therein. By containing microballoons therein, the fiber material 10A can contribute to reducing the weight of the fiber material 10A.

[0022] These microballoons may be organic or inorganic. Examples of organic microballoons include plastic microballoons. Examples of plastic microballoons include homopolymers of phenol, urea, styrene, saran, vinyl chloride, acrylonitrile, etc., or copolymers of two or more of these. Examples of inorganic microballoons include glass balloons, silica balloons, shirasu balloons, carbon balloons, alumina balloons, and zirconia balloons.

[0023] These microballoons may be surface-treated with an organic or inorganic surface treatment agent. Examples of organic surface treatment agents include fatty acids, resin acids, and fatty acid esters. Examples of inorganic surface treatment agents include calcium carbonate, barium sulfate, talc, titanium oxide, titanium, clay, and silica.

[0024] The average particle size of the microballoons is not particularly limited, and the lower limit of the average particle size may be, for example, 5 μm or more, 10 μm or more, 20 μm or more, 25 μm or more, or 30 μm or more, and the upper limit of the average particle size of the microballoons may be, for example, 300 μm or less, 100 μm or less, 80 μm or less, 50 μm or less, or 40 μm or less.

[0025] When the fiber material 10A contains microballoons, the content of the microballoons in the entire fiber material 10A can be appropriately set. The volume fraction of the microballoons in the entire fiber material 10A is, for example, 15 to 70% by volume, preferably 25 to 65% by volume, and more preferably 30 to 60% by volume. Setting the volume fraction within this range makes it easier to balance the handleability and lightness of the fiber material.

[0026] Since the fibrous material 10A can contain microballoons, the porosity of the fibrous material 10A may be set within an appropriate range, for example, from 15 to 70% by volume, preferably from 25 to 65% by volume, and more preferably from 30 to 60% by volume.

[0027] [Method for manufacturing a fiber material] Although not necessarily limited to the following, the above-described fiber material 10A can be manufactured by subjecting the above-described needle-punched nonwoven fabric to a half-cutting process. The half-cutting process may be performed according to a known method. That is, conditions may be adopted in which a cut of a predetermined thickness is made in a mat-like nonwoven fabric, and then a blade or the like may be applied to the nonwoven fabric.

[0028] As described above, when the fibrous material 10A contains microballoons, the microballoons can be encapsulated in the fibrous material 10A at any stage during the manufacturing process of the fibrous material 10A. For example, a precursor material for the microballoons can be encapsulated in the fibrous material 10A by encapsulating the precursor in the fibrous material 10A and then heating the fibrous material 10A to expand the precursor, thereby encapsulating the microballoons in the fibrous material 10A.

[0029] The obtained fiber material 10A may be wound into a roll, and such roll-shaped fiber material 10A may be traded commercially.

[0030] On the other hand, the fiber material 10A may be obtained by needle punching a nonwoven fabric in which the notches 3 have been formed.

[0031] [Uses of Fiber Material] In one example, the fiber material 10A of this embodiment is impregnated with a curable composition before use. That is, in this embodiment, it is possible to provide a curable material (mat-shaped curable material) obtained by impregnating the above-mentioned fiber material 10A with a curable composition. Here, since the fiber material 10A has needle-punched marks 2, the curable composition is appropriately impregnated, which can contribute to improving the strength of the curable material after curing. Below, examples of curable compositions that can be used are described.

[0032] [Curable Composition] The curable composition that can be impregnated into the fiber material 10A may be a known curable composition, and typically contains a resin material. The curable composition of this embodiment may be a thermosetting composition or a photocurable composition, but is preferably a thermosetting composition due to its ease of handling. The curable composition of this embodiment is preferably a combination of a component that generates radicals and a component that polymerizes due to the generated radicals. Components that can be preferably contained in the curable composition are described below.

[0033] (Radical Polymerizable Compound (A)) The curable composition of the present embodiment may contain a radical polymerizable compound (A). This radical polymerizable compound (A) is typically a compound containing a radical polymerizable group (typically a carbon-carbon unsaturated bond) in its chemical structure, and may be appropriately selected from known materials.

[0034] More specifically, the radical polymerizable compound (A) may contain a resin component such as a vinyl ester resin, an unsaturated polyester resin, a urethane (meth)acrylate resin, a polyester (meth)acrylate resin, or a polyether (meth)acrylate resin. When the curable composition contains a resin component in this manner, the composition of this embodiment may also be referred to as a "(curable) resin composition." The radical polymerizable compound (A) may also contain a radical polymerizable monomer or a polymer of this radical polymerizable monomer.

[0035] Among these, the curable composition of this embodiment preferably contains, as the radical polymerizable compound (A), one or more resins selected from the group consisting of vinyl ester resins, unsaturated polyester resins, and urethane (meth)acrylate resins. Furthermore, the curable composition of this embodiment preferably contains, as the radical polymerizable compound (A), a radical polymerizable monomer. It is also a preferred embodiment to construct the radical polymerizable compound (A) by combining the various resin components described above with the radical polymerizable monomer. The components corresponding to this radical polymerizable compound (A) will be further described below.

[0036] Vinyl Ester Resin The vinyl ester resin in this embodiment can be produced by a known method. For example, a desired resin can be obtained by reacting (condensing) an epoxy resin with (meth)acrylic acid in an inert gas stream or in an air atmosphere in the presence or absence of a known inhibitor or a known esterification catalyst. If necessary, other radically polymerizable monomers or organic solvents can be added to the reaction in order to reduce the melt viscosity of the reaction system. Since this vinyl ester resin is obtained by the above-mentioned production method, it is also called an "epoxy (meth)acrylate resin."

[0037] The vinyl ester resin in this embodiment may be, for example, a resin having an acrylate or methacrylate double bond at the molecular end, obtained by addition reaction of acrylic acid or methacrylic acid with an epoxy resin having two or more glycidyl ether groups per molecule. The epoxy resin having two or more glycidyl ether groups per molecule may be, for example, a bisphenol-type epoxy resin derived from bisphenol A, bisphenol F, bisphenol S, etc., or their derivatives; a bixylenol-type epoxy resin derived from bixylenol and its derivatives; a biphenol-type epoxy resin derived from biphenol and its derivatives; a naphthalene-type epoxy resin derived from naphthalene and its derivatives; or a novolac-type epoxy resin. These may be used alone or in combination of two or more. The epoxy equivalent, which is a measure of the molecular weight of the epoxy resin, is preferably 174 to 2000 eq / g.

[0038] Unsaturated Polyester Resin In one example, the unsaturated polyester resin in this embodiment can be obtained by, for example, a known dehydration condensation reaction of an unsaturated polybasic acid, a saturated polybasic acid, and a glycol, and typically has an acid value of 2 to 40 mgKOH / g. In producing the unsaturated polyester resin, a desired unsaturated polyester resin can be obtained by appropriately selecting and combining the acid components of the unsaturated polybasic acid and the saturated polybasic acid, and the glycols, and by appropriately selecting and combining the components in their blending ratios.

[0039] Examples of the unsaturated polybasic acids include maleic acid, maleic anhydride, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and glutaconic acid.

[0040] Examples of saturated polybasic acids include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, HET acid, and tetrabromophthalic anhydride.

[0041] Examples of glycols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, hydrogenated bisphenol A, bisphenol A propylene oxide compound, cyclohexanedimethanol, and dibromineopentyl glycol.

[0042] In this embodiment, among unsaturated polyester resins, unsaturated polyester resins using fumaric acid or maleic anhydride as the unsaturated polybasic acid, or isophthalic acid, terephthalic acid, or adipic acid as the saturated polybasic acid, and using ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, cyclohexanedimethanol, or neopentyl glycol as the main glycol component are preferred.

[0043] Urethane (meth)acrylate Resin The urethane (meth)acrylate resin in this embodiment is a resin that can be obtained, for example, by reacting a polyalcohol and / or polyester polyol and / or polyether polyol having two or more hydroxyl groups per molecule with a diisocyanate to produce an isocyanate at the molecular terminal, and / or one or more isocyanates per molecule, with a compound having an alcoholic hydroxyl group and one or more acrylate or methacrylate groups. Alternatively, the urethane (meth)acrylate resin can be obtained by first reacting a compound having an alcoholic hydroxyl group and one or more acrylate or methacrylate groups with a diisocyanate so that an isocyanate group remains, and then reacting the remaining isocyanate group with a polyalcohol and / or polyester polyol and / or polyether polyol having two or more hydroxyl groups per molecule. In producing a urethane (meth)acrylate resin, the physical properties of the resin can be adjusted by appropriately selecting a combination of an isocyanate with a polyalcohol and / or a polyester polyol and / or a polyether polyol, and a compound having an alcoholic hydroxyl group and one or more acrylate or methacrylate groups.

[0044] Examples of the compound having an alcoholic hydroxyl group and one or more acrylate or methacrylate groups include hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, phenoxyhydroxypropyl (meth)acrylate, trimethylolpropane di(meth)acrylate, and dipropylene glycol mono(meth)acrylate.

[0045] Furthermore, examples of the polyalcohol having two or more hydroxyl groups in one molecule include neopentyl glycol, ethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, propylene glycol, diethylene glycol, dipropylene glycol, trimethylene glycol, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct. The polyester polyol having two or more hydroxyl groups per molecule can be a saturated polyester polyol having a molecular weight of 1,000 to 2,000 obtained by the dehydration condensation reaction of a polyalcohol such as neopentyl glycol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, trimethylene glycol, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, or bisphenol A propylene oxide adduct with a polybasic acid such as adipic acid, phthalic acid (anhydride), isophthalic acid, terephthalic acid, or trimellitic acid. The polyether polyol having two or more hydroxyl groups per molecule can be a polyethylene glycol or polypropylene glycol having a molecular weight of 300 to 2,000 obtained by the ring-opening reaction of ethylene oxide or propylene oxide, or a polycaprolactone obtained by the ring-opening reaction of caprolactone. These can be used alone or in combination of two or more.

[0046] Examples of the compound having two or more isocyanate groups in one molecule include aromatic and / or aliphatic polyisocyanate compounds, such as tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, trifunctional isocyanates having an isocyanurate ring formed by trimerizing a bifunctional isocyanate compound, and commercially available isocyanate prepolymers modified with polyols. These compounds can be used alone or in combination of two or more.

[0047] Polyester(meth)acrylate Resin The polyester(meth)acrylate resin in this embodiment is, for example, a resin obtained by esterifying a polyester polyol with acrylic acid or methacrylic acid. Alternatively, it may be a resin obtained by reacting an acid-terminated polyester with an acrylate or methacrylate having a glycidyl group. In producing the polyester(meth)acrylate resin, the properties of the polyester(meth)acrylate resin can be adjusted by appropriately selecting the polyester polyol and acrylic acid or methacrylic acid, or the acid-terminated polyester and the acrylate or methacrylate having a glycidyl group.

[0048] Polyether(meth)acrylate Resin In this embodiment, the polyether(meth)acrylate resin is, for example, a resin obtained by esterifying a polyether polyol with acrylic acid or methacrylic acid. Alternatively, it may be a resin obtained by reacting an acid-terminated polyether with an acrylate or methacrylate having a glycidyl group. In producing the polyether(meth)acrylate resin, the properties of the polyester(meth)acrylate resin can be adjusted by appropriately selecting the polyether polyol and acrylic acid or methacrylic acid, or the acid-terminated polyester and the acrylate or methacrylate having a glycidyl group.

[0049] Radical Polymerizable Monomers, etc. Examples of the radical polymerizable monomer in this embodiment include styrene, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, ethylene glycol di(meth)acrylate, norbornene dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, etc. The radical polymerizable monomer may be either a solid monomer at room temperature (25° C.) or a liquid monomer at room temperature (25° C.).

[0050] The curable composition of the present embodiment may also contain a polymer of the above-described radically polymerizable monomer as the radically polymerizable compound (A). Examples of such a polymer include diallyl phthalate prepolymer, titan prepolymer, epoxy prepolymer, urethane prepolymer, and acrylate prepolymer.

[0051] The content of the radically polymerizable compound (A) in the entire curable composition is, for example, 25.5% by mass to 38% by mass, preferably 25.8% by mass to 36% by mass, and more preferably 26% by mass to 34% by mass. By setting the content within such a range, it becomes easier to balance the handleability during the molding process with the mechanical properties after curing.

[0052] When the radical polymerizable compound (A) contains a resin component, the content thereof is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 30 parts by mass or more, based on 100 parts by mass of the entire radical polymerizable compound (A). By setting the content of the resin component within this range, moldability in the molding process is improved. Although the entire radical polymerizable compound (A) can be used as the resin component, the content of the resin component can also be 95 parts by mass or less, or 90 parts by mass or less, based on 100 parts by mass of the entire radical polymerizable compound (A).

[0053] When the radical polymerizable compound (A) contains a radical polymerizable monomer, the content thereof is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 30 parts by mass or more, when the total amount of the radical polymerizable compound (A) is 100 parts by mass. Setting the content of the radical polymerizable monomer within this range improves application workability. Although the entire radical polymerizable compound (A) can be a radical polymerizable monomer, the content of the radical polymerizable monomer can also be 95 parts by mass or less or 90 parts by mass or less, when the total amount of the radical polymerizable compound (A) is 100 parts by mass.

[0054] (Radical Generator (B)) The curable composition of the present embodiment may also contain a radical generator (B). As described above, the curable composition of the present embodiment may contain a radical polymerizable compound (A). That is, by including the radical generator (B) in the composition in this manner, the polymerization reaction of the radical polymerizable compound (A) can be appropriately progressed, and the curability of the composition can be ensured.

[0055] Examples of the radical generator (B) include peroxides (organic peroxides) such as benzoyl peroxide, lauroyl peroxide, caproyl peroxide, di-n-propyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t-butyl peroxypivalate, and t-butylperoxy-2-ethylhexanate; hydrogen peroxide; and azo compounds such as 2,2'-azobis-isobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, and 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile. In addition to these components, this embodiment may also include a secondary material that improves radical generation ability, and these can be used in combination as the radical generator (B). In this specification, these combinations are sometimes collectively referred to as "radical generator (B)."

[0056] The radical generator (B) of this embodiment is preferably a combination of a peroxide (B1) and an organic acid cobalt compound (B2). Such a combination facilitates radical generation at low temperatures. Specific examples include a combination of Permec N (trade name, methyl ethyl ketone peroxide, manufactured by NOF Corporation) and a cobalt compound such as cobalt naphthenate, cobalt octylate, or cobalt octenate; and a combination of Perbutyl Z (trade name, tertiary butyl perbenzoate, manufactured by NOF Corporation) and a cobalt compound such as cobalt naphthenate, cobalt octylate, or cobalt octenate.

[0057] The content of the radical generator (B) in the curable composition of this embodiment is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 8 parts by mass, and even more preferably 0.3 to 5 parts by mass, relative to 100 parts by mass of the radical polymerizable compound (A). By setting the content within such a range, it becomes easier to achieve a balance between the curability of the composition and the mechanical properties after curing.

[0058] (Other Components) The curable composition of the present embodiment may contain additives other than the above components, such as resins other than those described above; thixotropic agents; thixotropic assistants; fillers; silane coupling agents; polymerization accelerators such as dimethylaniline; polymerization inhibitors such as hydroquinone; viscosity reducers; anti-settling agents; colorants containing one or more selected from the group consisting of dyes such as green, red, blue, yellow, and black dyes, pigments such as black pigments, and coloring materials; stress reducers; antifoaming agents; leveling agents; foaming agents; antioxidants; ion scavengers; and rubber components, as long as the object of the present invention is not impaired. These may be used alone or in combination of two or more.

[0059] The thixotropic agent may be either organic or inorganic. Examples of organic thixotropic agents include fatty acid amides (amide wax-based agents) synthesized from vegetable oil fatty acids and amines; hydrogenated castor oil-based agents; polyethylene oxide-based agents; polymerized oil-based agents; surfactant-based agents; and urea-modified compounds. Examples of inorganic thixotropic agents include clay minerals such as bentonites, talc, and mica. The amount of these thixotropic agents to be added is appropriately determined depending on the purpose.

[0060] The thixotropic aid may be, for example, a polyhydroxycarboxylic acid ester derivative, a polycarboxylic acid amide derivative, or a polyether phosphate ester derivative. Examples of polyhydroxycarboxylic acid ester derivatives that can be used include BYK-R 606 (trade name, manufactured by BYK Japan KK). Examples of polycarboxylic acid amide derivatives that can be used include BYK-405 and BYK-R 605 (trade names, manufactured by BYK Japan KK). Examples of polyether phosphate ester derivatives that can be used include Disparlon 3500 (trade name, manufactured by Kusumoto Chemicals Co., Ltd.).

[0061] Other specific examples of thixotropic aids include anionic surfactants, cationic surfactants, nonionic surfactants, betaine surfactants, and polyethylene glycol. Examples of anionic surfactants that can be used include higher fatty acid alkali salts, alkyl sulfates, alkyl sulfonates, alkylaryl sulfonates, and sulfosuccinate salts. Examples of cationic surfactants that can be used include higher amine halogen salts, alkylpyridinium halides, and quaternary ammonium salts. Examples of nonionic surfactants that can be used include polyethylene glycol alkyl ethers, polyethylene glycol fatty acid esters, sorbitan fatty acid esters, and fatty acid monoglycerides. Examples of betaine surfactants that can be used include amino acids. The average molecular weight of polyethylene glycol used as a thixotropic aid is not particularly limited, but can be set to 200 to 1500, or 250 to 1000, for example.

[0062] The above-mentioned filler may include silica, alumina, calcium carbonate, magnesium carbonate, barium carbonate, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, etc. These fillers may be used alone or in combination, and the particle size and blending amount thereof may be set as desired.

[0063] (Method for producing curable composition) The curable composition of this embodiment can be produced by mixing the above-mentioned materials. For example, the materials can be mixed using a mixer such as a homodisper, homomixer, universal mixer, planetary mixer, kneader, or three-roll mill to obtain a predetermined curable composition. The temperature conditions, stirring conditions, etc. during mixing can be set appropriately depending on the materials used.

[0064] [Uses of Curable Material (Laminate)] The above-mentioned curable material contains a curable composition, and therefore, a cured product can be obtained by subjecting it to predetermined curing conditions (i.e., such a cured product can be said to be obtained by curing the curable material). Here, the curable material can be used, for example, for producing various laminates. This laminate typically comprises a cured product of the above-mentioned curable material and another material laminated on a first surface of the cured product and / or a surface opposite to the first surface.

[0065] A more specific example of such a laminate will be described with reference to the drawings. Figure 3 is a cross-sectional view showing a laminate 100 to which a fiber material 10A is applied.

[0066] The laminate 100 shown in Fig. 3 has fiber reinforced plastics 11 and 12 laminated on the upper and lower surfaces (a first surface and a surface opposite the first surface) of a cured product 20A. Here, this cured product 20A is obtained by curing a curable material using a fiber material 10A. The fiber reinforced plastics 11 and 12 here are composites of a fiber substrate and a curable composition. In other words, the fiber reinforced plastics 11 and 12 shown in Fig. 3 may be composites of a fiber substrate and a cured product of a curable composition (which may also be referred to as FRP).

[0067] The fiber base material that can be used to form the fiber reinforced plastics 11 and 12 includes glass fiber, carbon fiber, aramid fiber, Zylon fiber, vinylon fiber, polyethylene fiber, boron fiber, basalt fiber, cellulose, etc. Among these fiber base materials, it is preferable that the fiber base material that can be used to form the fiber reinforced plastics 11 and 12 is glass fiber. By adopting such an embodiment, the strength, specific gravity, etc. of the FRP after curing can be made suitable.

[0068] On the other hand, the curable composition may be the same as the curable composition constituting the curable material described above, or may be a different composition.

[0069] The content of the fiber base material in fiber reinforced plastics 11, 12 can be, for example, 10% by mass to 90% by mass, and from the standpoint of mechanical properties and moldability, it can be preferably 20% by mass to 80% by mass.

[0070] On the other hand, the content ratio of the cured product of the curable composition in fiber reinforced plastics 11 and 12 can be, for example, 10 to 90% by mass, and from the viewpoints of mechanical properties and moldability, it can be preferably 20 to 80% by mass.

[0071] Such a laminate 100 can be manufactured by, for example, combining the following steps (S1) and (S2): (S1) a step of laminating fiber-reinforced plastics 11 and 12 (other materials) and the curable material; and (S2) a step of curing at least the curable material.

[0072] Step (S1) may be performed by first obtaining a curable material and then laminating it on fiber-reinforced plastic 11 or the like (another material), or by laminating fiber material 10A on fiber-reinforced plastic 11 or the like, and then impregnating fiber material 10A with a curable composition to convert fiber material 10A into a curable material. Note that while FIG. 3 shows laminate 100 using one layer of curable material, the curable material to be laminated may be a combination of multiple fiber materials 10A (for example, two or more curable materials may be interposed between fiber-reinforced plastics 11 and 12).

[0073] Furthermore, in step (S2), the curable composition contained in the curable material is cured. The curing conditions can be appropriately set depending on the contents of the curable composition. For example, when a combination of a peroxide (B1) and an organic acid cobalt compound (B2) is used as the radical generator (B), curing can be performed near room temperature (for example, a temperature range of −5°C to 50°C). On the other hand, when heating is required for the radical generator (B) to generate radicals, heating conditions can be selected depending on the type of radical generator (B). For example, the heating conditions may be above 50°C, above 70°C, or above 100°C. The upper limit of the heating conditions is not limited, but is, for example, 300°C or less. For heating, a known oven or the like can be used.

[0074] Alternatively, step (S2) may be performed by heating a laminate obtained by laminating the fiber reinforced plastics 11, 12 and the curable material using a press molding machine or the like.

[0075] 3 shows an example in which fiber-reinforced plastics 11 and 12 are used as the materials constituting the laminate 100, but the materials that can be laminated onto the cured product 20A are not limited to these. For example, various metal members or ceramic members may be laminated onto the cured product 20A. Furthermore, the material onto which the cured product 20A is laminated does not necessarily have to have a flat surface. In other words, even if the material to be laminated has a curved surface, the fiber material 10A that serves as the base material of the cured product 20A has the notch 3, and therefore can easily follow the curved surface.

[0076] Furthermore, the laminate 100 may constitute various components. That is, the application of the laminate 100 can be set appropriately. Examples include, but are not limited to, components for electrical and electronic devices, office automation equipment, information terminal equipment, machine parts, home appliances, vehicle parts, building materials, various containers, leisure goods and miscellaneous goods, lighting equipment, and the like.

[0077] [Modifications] The fiber material of this embodiment may also be as shown below. Fig. 4 is a plan view showing a modification of the fiber material. Note that the following fiber materials 10B, 10C, etc. may have the various features described for the fiber material 10A.

[0078] That is, as shown in Fig. 4, the fiber material (fiber materials 10B, 10C) may have cutouts 3 so as to define closed regions with the cutouts 3 as boundaries when the fiber material is observed from the normal direction of the first surface. Here, the closed regions may be configured to have various shapes such as circles, ellipses, polygons (triangles, rectangles, pentagons, hexagons), etc., but preferably the closed regions have polygonal shapes as shown in Fig. 4 (Fig. 4 shows fiber material 10B having lattice-shaped cutouts 3 and fiber material 10C having honeycomb-shaped cutouts 3). By adopting such an embodiment, the handleability of the fiber material is further improved.

[0079] Although Figure 1 shows a fiber material 10A having a notch 3 on the first surface, the fiber material may also have a notch 3 on the first surface as well as on the surface opposite the first surface.

[0080] Furthermore, it may be provided in the following aspects.

[0081] (1) A mat-shaped fibrous material including a nonwoven fabric, wherein a first surface of the fibrous material has a notch extending from the first surface to the interior of the fibrous material, and the fibrous material has needle punch marks penetrating the fibrous material.

[0082] (2) In the fiber material described in (1) above, when the fiber material is observed from the normal direction of the first surface, the notch defines a closed area with the notch as a boundary.

[0083] (3) The fiber material according to (2) above, wherein the closed region has a polygonal shape.

[0084] (4) In the fiber material according to any one of (1) to (3), the average thickness T ０ A fibrous material having a diameter in the range of 0.5 to 10 mm.

[0085] (5) In the fiber material according to any one of (1) to (4) above, the average thickness T ０ The average depth T of the notch １ The ratio T １ / T ０ is in the range of 0.1 to 0.99.

[0086] (6) The fiber material according to any one of (1) to (5) above, which contains microballoons therein.

[0087] (7) A mat-shaped curable material, which is obtained by impregnating the fiber material according to any one of (1) to (6) above with a curable composition.

[0088] (8) A cured product obtained by curing the curable material described in (7) above.

[0089] (9) A laminate comprising a cured product of the curable material according to (7) above and another material laminated on the first surface of the cured product and / or on a surface opposite to the first surface. Of course, this is not a limitation.

[0090] The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited to the following examples.

[0091] [Example] First, a nonwoven fabric (thickness 3 mm) made of a polyester sheet (PET) with a porosity of 60% was prepared. One side of this nonwoven fabric was subjected to a honeycomb structure cutout (half cut) treatment, and needle punch marks were made at arbitrary intervals. In this example, the length of one side of the honeycomb structure was set to 5 mm, the average depth of the cutout was set to 2.9 mm, the diameter of the needle punch marks was set to 1.0 mm, and the number (density) of needle punch marks was set to 200 / 100 cm. ２ The nonwoven fabric subjected to such treatment is hereinafter referred to as "Example fiber material (Example)."

[0092] [Comparative Example] A nonwoven fabric similar to that of the example was prepared, and a fiber material was obtained in the same manner as in the example, except that the half-cutting treatment was not performed. The fiber material obtained in this manner is hereinafter referred to as the "fiber material of the comparative example (comparative example)."

[0093] <Appearance Comparison> Figure 5 is a photograph showing the fiber material of the Example. Figure 6 is a photograph showing a comparison of the fiber materials of the Example and the Comparative Example. As shown in Figure 5, the fiber material of the Example is easily deformed by the notch. This suggests that the fiber material of the Example is expected to have improved shaping properties when obtaining a composite material. Figure 6A shows the fiber material of the Example laminated on a substrate having a curved surface, and Figure 6B shows the fiber material of the Comparative Example laminated on a similar substrate. Comparison of these figures also supports the idea that half-cut processing improves the ability to follow the curved surface of the substrate.

[0094] <Comparison of Mechanical Strength> The following test specimens were prepared using the fiber materials of the Examples and Comparative Examples. First, two #450 glass mats were prepared, and the fiber materials of the Examples and Comparative Examples were placed between the glass mats to obtain a laminated structure. This laminated structure was impregnated with a curable composition using the VaRTM molding method and cured to obtain a composite material. The curable composition used here was a mixture of unsaturated polyester resin "4072PT" manufactured by Nippon U-Pica Corporation and a curing agent (Permec N) manufactured by NOF Corporation. The amount of curing agent was set to 1 wt% based on the weight of the unsaturated polyester resin. The curing conditions were curing at room temperature for 24 hours, followed by post-curing at 80°C for 3 hours. The composite material thus obtained was then cut into a predetermined shape to obtain a test specimen. The thickness of the test specimen was 2.97 mm.

[0095] The flexural strength and flexural modulus of both the obtained test pieces were measured in accordance with JIS K 7017. The results are shown in Table 1 below. In this test, a test speed of 1 mm / min was adopted, and for the test pieces using the fiber material of the example, the half-cut surface was placed downward, and a load was applied from the surface opposite to the half-cut surface, to perform the measurement.

[0096]

[0097] The comparison in Table 1 shows that the use of the fiber materials of the examples improves the mechanical strength of the resulting composite material. Although not necessarily limited to the mechanism below, this improvement in mechanical strength is thought to be due to the curable composition (cured resin) flowing appropriately into the notches in the fiber material.

[0098] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0099] 1: Nonwoven fabric, 2: Needle punch mark, 3: Notch, 10A, 10B, 10C: Fiber material, 11, 12: Fiber reinforced plastic, 20A: Cured product, 100: Laminate, T ０ : average thickness, T １ : Average depth

Claims

1. A mat-like fibrous material including a nonwoven fabric, wherein a first surface of the fibrous material has a notch extending from the first surface to an interior of the fibrous material, and the fibrous material has needle punch marks penetrating the fibrous material.

2. A fiber material as described in claim 1, wherein, when the fiber material is observed from the normal direction of the first surface, the notch defines a closed area with the notch as a boundary.

3. A fiber material according to claim 2, wherein the closed region has a polygonal shape.

4. The fiber material according to any one of claims 1 to 3, wherein the average thickness T of the fiber material is ０ A fibrous material having a diameter in the range of 0.5 to 10 mm.

5. The fiber material according to any one of claims 1 to 4, wherein the average thickness T of the fiber material is ０ The average depth T of the notch １ The ratio of T １ / T ０ A fiber material having a fiber density in the range of 0.1 to 0.

99.

6. A fiber material according to any one of claims 1 to 5, comprising microballoons therein.

7. A mat-shaped curable material, comprising a fiber material according to any one of claims 1 to 6 impregnated with a curable composition.

8. A cured product obtained by curing the curable material according to claim 7.

9. A laminate comprising: a cured product of the curable material according to claim 7; and another material laminated on the first surface of the cured product and / or on a surface opposite to the first surface.

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