One-pack curable composition

Abstract

Provided is a one-pack curable composition containing (A) an epoxy resin, (B) a solid rubber, (C) a latent curing agent, (D) a filler, and (E) a foaming agent, the one-pack curable composition containing (A) an unmodified bisphenol epoxy resin (A1), the one-pack curable composition containing 10-100 parts by mass of (B) per 100 parts by mass of (A), and the one-pack curable composition containing (A2) an unmodified bisphenol epoxy resin (A3) per 100 parts by mass of (A), and the one-pack curable composition containing (A4) an unmodified bisphenol epoxy resin (A4) per 100 parts by mass of (A), and the one-pack curable composition containing (A5) an unmodified bisphenol epoxy resin (A5) per 100 parts by mass of (A). (B) contains (B1) a styrene-butadiene-divinylbenzene copolymer.

Description

Technical Field

[0001] The present invention relates to a one - liquid curable composition, and more specifically, to a coating - type one - liquid curable composition containing (A) an epoxy resin, (B) a solid - form rubber, (C) a latent curing agent, (D) a filler, and (E) a foaming agent. Background Art

[0002] For the weight reduction of an automobile body, thin - thickness metal plates are used. To ensure the tensile rigidity and dent resistance of the metal plates, metal - plate reinforcing materials are used. Generally, metal - plate reinforcing materials have a three - layer structure of a so - called glass cloth - adhesive - release paper and are commercially available as shaped articles having a certain plate - like shape. Such shaped metal - plate reinforcing materials are used after being adjusted to a desired shape. The shaped metal - plate reinforcing material is adhered to the metal plate, but due to the influence of the use environment, problems such as a decrease in adhesiveness and a shift in the adhered position occur, so correction by a person (operator) is required. Therefore, it is difficult to fully automate the metal - plate reinforcement using shaped metal - plate reinforcing materials, which inevitably reduces productivity. In addition, due to the disposal of the above - mentioned release paper, there may be an increase in cost and an environmental load due to the generation of waste. Therefore, a fully - automatable metal - plate reinforcing material is needed. As such a metal - plate reinforcing material, a metal - plate reinforcing material available for automatic coating is being studied.

[0003] For example, Patent Document 1 discloses a coating - type metal - plate reinforcing material composition in which an inorganic filler having a specific aspect ratio (L / D) is mixed into a liquid composition of a thermosetting epoxy resin to form a high - viscosity viscous material. Patent Document 1 discloses that the coating - type metal - plate reinforcing material composition can be coated under heating and, through cooling and curing after coating, does not scatter, dissolve, or fall off during the process until curing and sintering, and in terms of the reinforcing effect, it can also improve the bending strength and rigidity of the metal plate and does not cause deformation of the metal plate after curing (see Patent Document 1

[0005] ).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 3547404 Specification Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] Although the coated metal plate reinforcing material disclosed in the invention patent document 1 has excellent properties, it is also required to improve the reinforcement while suppressing deformation, and to improve the spray resistance while maintaining pump dischargeability. On the other hand, the patent document 1 does not teach that the coated metal plate reinforcing material is obtained by making a high-viscosity viscous material, improving the bending strength, improving the spray resistance, and maintaining low viscosity and pump dischargeability.

[0009] Therefore, an object of the present invention is to provide a one-component curable composition that can be heated and applied while maintaining low viscosity, but will not scatter, dissolve or fall off in the process from coating to curing and sintering, especially for spraying, chemical conversion treatment liquid, and electrodeposition liquid, and will not cause deformation of the metal plate although the bending strength and rigidity of the metal plate are improved after curing.

[0010] Solution to the problem

[0011] The present inventors have repeatedly conducted in-depth research and found that by using a specific solid rubber, styrene-butadiene-divinylbenzene copolymer, and a foaming agent, a one-component curable composition can be obtained that improves reinforcement while suppressing deformation and improves spray resistance while maintaining pump dischargeability. In addition, it was found that such a one-component curable composition can be applied to a metal plate and can be used as a coating type metal plate reinforcing material, thereby completing the present invention.

[0012] This specification includes the following embodiments.

[0013] 1. A one-component curable composition comprising (A) an epoxy resin, (B) a solid rubber, (C) a latent curing agent, (D) a filler, and (E) a foaming agent, wherein:

[0014] (A) epoxy resin contains (A1) unmodified bisphenol type epoxy resin,

[0015] The one-component curable composition contains 10 to 100 parts by mass of (B) a solid rubber per 100 parts by mass of (A) an epoxy resin.

[0016] (B) The solid rubber contains (B1) a styrene-butadiene-divinylbenzene copolymer.

[0017] 2. The one-component curable composition according to 1 above, wherein

[0018] 40℃ and shear rate 430sec -1 The viscosity is 50 to 300 Pa·s.

[0019] 3. The one - component curable composition according to 1 or 2 above, wherein,

[0020] (A) The epoxy resin contains 25 to 90% by mass of (A1) unmodified bisphenol - type epoxy resin based on 100% by mass of the epoxy resin.

[0021] 4. The one - component curable composition according to any one of 1 to 3 above, wherein,

[0022] (A) The epoxy resin contains 15 to 40% by mass of aromatic rings based on 100% by mass of the epoxy resin.

[0023] 5. The one - component curable composition according to any one of 1 to 4 above, wherein,

[0024] (E) The foaming agent contains at least one selected from the group consisting of ADCA - type chemical foaming agents, OBSH - type chemical foaming agents, and unexpanded balloons.

[0025] 6. The one - component curable composition according to any one of 1 to 5 above, wherein,

[0026] The foaming ratio is 10 to 200%.

[0027] 7. The one - component curable composition according to any one of 1 to 6 above, wherein,

[0028] (D) The filler contains needle - shaped fillers with a length of 0.5 mm or more.

[0029] 8. The one - component curable composition according to any one of 1 to 7 above, wherein,

[0030] (B) The solid - state rubber further contains (B2) styrene - butadiene copolymers.

[0031] 9. The one - component curable composition according to any one of 1 to 8 above, wherein,

[0032] (B) The solid - state rubber further contains (B3) nitrile - butadiene copolymers.

[0033] 10. The one - component curable composition according to any one of 1 to 9 above, wherein,

[0034] (B1) The acid content of the solid - state rubber and / or (B2) the solid - state rubber is 0.2 to 8% by mass.

[0035] 11. The one - component curable composition according to any one of 1 to 10 above, wherein,

[0036] (A) The epoxy resin contains (A2) a low-viscosity epoxy resin. The epoxy equivalent of the (A2) low-viscosity epoxy resin is 250 to 700, and it has a viscosity of 40 to 5000 mPa·s at 25°C.

[0037] 12. The one-component curable composition according to item 11 above, wherein

[0038] (A2) The low-viscosity epoxy resin contains (A2-1) a diester epoxy resin.

[0039] 13. The one-component curable composition according to any one of items 1 to 12 above, wherein

[0040] (D) The filler contains an inorganic filler having an aspect ratio (L / D) of 5 or more.

[0041] 14. The one-component curable composition according to any one of items 1 to 13 above, wherein

[0042] The one-component curable composition is a coating-type one-component curable composition.

[0043] 15. The one-component curable composition according to any one of items 1 to 14 above, wherein

[0044] The one-component curable composition is used for reinforcing a metal plate and can be pumped out.

[0045] Advantages of the Invention

[0046] The one-component curable composition according to an embodiment of the present invention can improve the reinforcement property while suppressing deformation, and can improve the spray resistance while maintaining the pumpability. In addition, the one-component curable composition can be suitably coated on a metal plate and can be suitably used as a coating-type metal plate reinforcing material. Detailed Embodiments

[0047] An important aspect of this specification is

[0048] to provide a one-component curable composition containing (A) an epoxy resin, (B) a solid rubber, (C) a latent curing agent, (D) a filler, and (E) a foaming agent.

[0049] Regarding this one-component curable composition,

[0050] (A) The epoxy resin contains (A1) an unmodified bisphenol-type epoxy resin,

[0051] In this one-component curable composition, 10 to 100 parts by mass of (B) the solid rubber is contained relative to every 100 parts by mass of (A) the epoxy resin.

[0052] (B) The solid rubber contains (B1) a styrene-butadiene-divinylbenzene copolymer.

[0053] In this specification, (A) the epoxy resin refers to a thermosetting resin that can be cured by crosslinking and networking through the existing epoxy groups, which is usually called an epoxy resin. As long as the curable composition of the present invention can be obtained, there is no particular limitation.

[0054] (A) The epoxy resin can be, for example, a glycidyl ether type epoxy resin, a glycidyl amine type epoxy resin, a glycidyl ester type epoxy resin, etc.

[0055] Preferably, (A) the epoxy resin contains (A1) an unmodified bisphenol type epoxy resin.

[0056] (A1) The unmodified bisphenol type epoxy resin refers to an epoxy resin having a bisphenol skeleton. In particular, as long as it is not modified and the epoxy resin composition of the present invention can be obtained, there is no particular limitation.

[0057] As (A1) the unmodified bisphenol type epoxy resin, for example, diglycidyl ethers of bisphenol A, bisphenol F, brominated bisphenol A, bisphenol AD, etc. can be exemplified.

[0058] (A1) The viscosity of the unmodified bisphenol type epoxy resin preferably has a viscosity of 1500 mPa·s or more at 25°C, more preferably has a viscosity of 2000 - 25000 mPa·s, further preferably has a viscosity of 2500 - 20000 mPa·s, and further more preferably has a viscosity of 3000 - 15000 mPa·s.

[0059] (A1) The epoxy equivalent of the unmodified bisphenol type epoxy resin is preferably 150 - 800 g / eq, more preferably 160 - 500 g / eq, further preferably 165 - 250 g / eq, and further more preferably 170 - 200 g / eq. When the epoxy equivalent of (A1) the unmodified bisphenol type epoxy resin is 150 - 800 g / eq, the operability is more excellent.

[0060] As (A1) the unmodified bisphenol type epoxy resin, commercially available products can be used. As these commercially available products, for example, "jER (registered trademark) 828", "jER (registered trademark) 1001", and "jER (registered trademark) 807" manufactured by Mitsubishi Chemical Corporation, etc. can be exemplified.

[0061] (A) The epoxy resin preferably contains 25 to 90% by mass of (A1) unmodified bisphenol type epoxy resin based on 100% by mass of the epoxy resin, and may contain 25 to 60% by mass, more preferably contains 29 to 80% by mass, may contain 29 to 56% by mass, further preferably contains 33 to 65% by mass, still further preferably contains 33 to 52% by mass, and even more preferably contains 35 to 49% by mass.

[0062] When the (A) epoxy resin contains 25 to 90% by mass of (A1) unmodified bisphenol type epoxy resin based on 100% by mass of the epoxy resin, the curable composition of the embodiment of the present invention can improve Tg, elastic modulus and flexural strength more balancedly.

[0063] (A) The epoxy resin may contain (A2) low-viscosity epoxy resin. The (A2) low-viscosity epoxy resin refers to an epoxy resin having a viscosity of less than 5000 mPa·s at 25°C, preferably having a viscosity of 40 to 5000 mPa·s, more preferably having a viscosity of 45 to 4000 mPa·s, further preferably having a viscosity of 50 to 3000 mPa·s, and even more preferably having a viscosity of 60 to 2500 mPa·s.

[0064] When the (A) epoxy resin contains the (A2) low-viscosity epoxy resin, the curable composition of the embodiment of the present invention can ensure the pump dischargeability at a relatively low temperature (40 - 50°C).

[0065] (A2) The low-viscosity epoxy resin preferably has an epoxy equivalent of 250 to 700, more preferably 280 to 680, and further preferably 300 to 650.

[0066] When the (A) epoxy resin contains the (A2) low-viscosity epoxy resin and the (A2) low-viscosity epoxy resin has an epoxy equivalent of 250 to 700, the curable composition of the embodiment of the present invention has flexibility and the displacement amount at the maximum strength of the bending test becomes larger.

[0067] When the (A) epoxy resin contains the (A2) low-viscosity epoxy resin, the (A2) low-viscosity epoxy resin has an epoxy equivalent of 250 to 700 and has a viscosity of 40 to 5000 mPa·s at 25°C, the curable composition of the embodiment of the present invention can exhibit the above two effects.

[0068] (A2) The low-viscosity epoxy resin may contain (A2-1) dibasic acid ester type epoxy resin.

[0069] (A2-1) The dibasic acid ester type epoxy resin includes epoxy resins based on esters of dibasic acids (for example, dimer acids of long-chain dibasic acids, phthalic acid, hydrogenated phthalic acid, etc.).

[0070] (A2-1) The diester epoxy resin is not particularly limited as long as it meets the above-mentioned (A2) low-viscosity epoxy resin and can obtain the epoxy resin composition of the present invention.

[0071] As the (A2-1) diester epoxy resin, commercially available products can be used. As those commercially available products, for example, "jER (registered trademark) 871" (dimer acid glycidyl ester) manufactured by Mitsubishi Chemical Corporation can be exemplified.

[0072] (A2) The low-viscosity epoxy resin may also contain diglycidyl ethers of epoxide adducts such as bisphenol A, bisphenol F, and bisphenol AD, bifunctional epoxy resins used as reactive diluent materials, and monofunctional epoxy resins that form part of the epoxy resin.

[0073] (A) The epoxy resin preferably contains 20 to 80% by mass of the (A2) low-viscosity epoxy resin based on 100% by mass of the (A) epoxy resin, more preferably contains 30 to 75% by mass, further preferably contains 40 to 70% by mass, and even more preferably contains 50 to 65% by mass.

[0074] When the (A) epoxy resin contains 20 to 80% by mass of the (A2) low-viscosity epoxy resin based on 100% by mass of the (A) epoxy resin, the curable composition of the embodiment of the present invention can ensure the pump dischargeability at a relatively low temperature (40 - 50°C).

[0075] It should be noted that the (A2) low-viscosity epoxy resin does not contain the (A1) unmodified bisphenol type epoxy resin.

[0076] (A) The epoxy resin may contain (A3) other epoxy resins that do not belong to the (A1) unmodified bisphenol type epoxy resin and the (A2) low-viscosity epoxy resin.

[0077] (A3) Other epoxy resins refer to epoxy resins that do not belong to the (A1) unmodified bisphenol type epoxy resin and the (A2) low-viscosity epoxy resin, and are not particularly limited as long as the curable composition of the present invention can be obtained.

[0078] (A) The epoxy resin may contain 40% by mass or less of the (A3) other epoxy resins based on 100% by mass of the epoxy resin, may also contain 30% by mass, or may also contain 20% by mass or less.

[0079] As such other epoxy resins of (A3), for example, rubber-modified epoxy resins [reaction products obtained by mixing bisphenol-type epoxy resins (diglycidyl ethers of bisphenol A, bisphenol F, bisphenol AD, diglycidyl ethers of epoxy adducts of bisphenol A, etc.) and butadiene-acrylonitrile-(meth)acrylic acid copolymers in a mass ratio of 1:5 to 4:1, preferably 1:3 to 3:2, and reacting at a temperature of 80 to 180°C, etc.], polyurethane-modified epoxy resins [reaction products obtained by reacting a polyurethane prepolymer obtained by adding a polyisocyanate to the end of a polyalkylene glycol with the hydroxyl groups of an epoxy resin (mixing ratio of 10:90 to 50:50); for example, reaction products of a polyurethane prepolymer containing terminal NCO obtained by reacting an excess of diisocyanate (toluene diisocyanate, diphenylmethane diisocyanate, etc.) with polytetramethylene ether glycol (molecular weight 500 to 5000) and an epoxy resin containing OH (diglycidyl ether of bisphenol A, diglycidyl ether of aliphatic polyol, etc.)], carboxyl-terminated butadiene acrylonitrile copolymer (CTBN)-modified epoxy resins [reaction products obtained by mixing bisphenol-type epoxy resins (diglycidyl ethers of bisphenol A, bisphenol F, bisphenol AD, diglycidyl ethers of epoxy adducts of bisphenol A, etc.) and a carboxyl-terminated butadiene-acrylonitrile copolymer rubber in a mass ratio of 1:5 to 4:1, preferably 1:3 to 3:2, and reacting at a temperature of 80 to 180°C, etc.], acrylic acid-modified epoxy resins [reaction products obtained by reacting the carboxyl groups on the surface of acrylic rubber particles with an epoxy resin (mixing ratio of 10:90 to 50:50), etc.] can be cited.

[0080] (A) The content of the aromatic ring of the epoxy resin is preferably 15 to 40% by mass, more preferably 18 to 35% by mass, still more preferably 20 to 32% by mass, and even more preferably 25 to 30% by mass based on 100% by mass of the (A) epoxy resin.

[0081] When the content of the aromatic ring of the (A) epoxy resin is 15 to 40% by mass based on 100% by mass of the (A) epoxy resin, the curable composition of the embodiment of the present invention can more evenly improve Tg, elastic modulus, and flexural strength.

[0082] In the curable composition of the embodiment of the present invention, with respect to every 100 parts by mass of the curable composition, for example, 25 to 80 parts by mass of the (A) epoxy resin can be contained, preferably 30 to 70 parts by mass of the (A) epoxy resin are contained, more preferably 35 to 65 parts by mass of the (A) epoxy resin are contained, and still more preferably 40 to 60 parts by mass of the (A) epoxy resin are contained.

[0083] In the curable composition according to the embodiment of the present invention, when 25 to 80 parts by mass of (A) epoxy resin is contained with respect to every 100 parts by mass of the curable composition, the curability and flexural strength of the curable composition according to the embodiment of the present invention can be further improved.

[0084] In the present specification, the (B) solid-form rubber is a rubbery substance in a solid form and is not particularly limited as long as the curable composition of the present invention can be obtained.

[0085] In the present specification, the "solid form" of the "solid-form rubber" means that the rubber is in a solid form at room temperature (23 °C). In the case where the rubber coexists with a liquid component, it means that the part of the rubber other than the liquid component is in a solid form at room temperature (23 °C). Therefore, when the rubber coexists with a liquid component at room temperature and there is a case of dissolution and / or swelling, if the liquid component is removed and the rubber is in a solid form at room temperature (23 °C), it belongs to the solid-form rubber.

[0086] (B) The solid-form rubber contains (B1) styrene-butadiene-divinylbenzene copolymer. The curable composition according to the embodiment of the present invention can obtain the beneficial effects of suppressing the decrease in Tg, suppressing the decrease in strength caused by foaming (displacement at the maximum strength in the bending test), and further improving the spray resistance.

[0087] (B) The solid-form rubber preferably contains 20 to 80% by mass of (B1) styrene-butadiene-divinylbenzene copolymer based on 100% by mass of (B) solid-form rubber, more preferably contains 25 to 75% by mass, still more preferably contains 30 to 70% by mass, and even more preferably contains 35 to 65% by mass.

[0088] Preferably, the (B) solid-form rubber further contains at least one selected from the group consisting of styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, ethylene-propylene-diene copolymers, isoprene polymers, and butadiene polymers.

[0089] (B) The solid-form rubber may contain (B2) styrene-butadiene copolymer or may contain (B3) acrylonitrile-butadiene copolymer.

[0090] (B) When the solid-form rubber contains (B2) styrene-butadiene copolymer, it can suppress the decrease in Tg of the cured product (reinforcing material) of the curable composition according to the embodiment of the present invention, ensure the reinforcing property, and suppress the decrease in strength caused by foaming (displacement at the maximum strength in the bending test).

[0091] In the case where the (B) solid rubber contains the (B3) acrylonitrile-butadiene copolymer, the displacement amount at the maximum strength in the bending test of the curable composition according to the embodiment of the present invention can be further increased.

[0092] The acid content of the (B1) solid rubber and / or the (B2) solid rubber is preferably 0.2 to 8% by mass, more preferably 0.3 to 6% by mass, and still more preferably 0.5 to 4% by mass.

[0093] When the acid content of the (B1) solid rubber and / or the (B2) solid rubber is 0.2 to 8% by mass, the storage stability of the curable composition according to the embodiment of the present invention can be further improved.

[0094] In the curable composition according to the embodiment of the present invention, with respect to 100 parts by mass of the (A) epoxy resin, for example, 10 to 100 parts by mass of the (B) solid rubber can be contained, preferably 20 to 90 parts by mass of the (B) solid rubber, more preferably 30 to 80 parts by mass of the (B) solid rubber, and still more preferably 40 to 70 parts by mass of the (B) solid rubber.

[0095] In the curable composition according to the embodiment of the present invention, when 10 to 100 parts by mass of the (B) solid rubber is contained with respect to 100 parts by mass of the (A) epoxy resin, the anti-deformation property of the curable composition according to the embodiment of the present invention can be further improved, and at the same time, the displacement amount at the maximum strength in the bending test can be further increased.

[0096] In the present specification, the (C) latent curing agent refers to a compound that is a curing agent for the (A) epoxy resin but does not substantially function as a curing agent at room temperature, but functions as a curing agent by heating (for example, 165 °C, preferably 150 °C), and there is no particular limitation as long as the curable composition of the present invention can be obtained.

[0097] As latent curing agents, specifically, examples thereof include dicyandiamide; diacylhydrazide compounds such as adipic dihydrazide, sebacic dihydrazide, isophthalic dihydrazide, dodecanedioic dihydrazide, 1,3-bis(hydrazinocarbonylethyl)-5-isopropylhydantoin, eicosanedioic dihydrazide, hydroquinone diglycolic dihydrazide, resorcinol diglycolic dihydrazide, 4,4'-vinylbisphenol diglycolic dihydrazide; 4,4'-diaminodiphenylsulfone; imidazole compounds such as imidazole, 2-n-heptadecylimidazole, 2-undecylimidazole; melamine; triazine compounds such as 2,4-diamino-6-(2'-methylimidazoline(1')-ethyl)-o-triazine; benzoguanamine; N,N-dialkylurea compounds such as N,N-dimethyl-N'-(3,4-dichlorophenyl)urea, N,N'-dialkylurea compounds; N,N'-dialkylthiourea compounds; polyamines such as diaminodiphenylmethane, diaminobiphenyl, diaminophenyl, phenylenediamine, toluenediamine, dodecanediamine, sebac diamine, octanediamine, tetradecanediamine, hexadecanediamine, polyoxypropylene diamine, acylhydrazide polyamine; guanidine derivatives such as cyanoguanidine.

[0098] As latent curing agents, commercially available products can be used. For example, CG-NA (trade name) manufactured by Air Products, EH-4030s (trade name) manufactured by ADEKA, ADH (trade name) manufactured by Otsuka Chemical Co., Ltd., EH3731s (trade name) manufactured by ADEKA, Dyhard UR200 (trade name) manufactured by AlzChem, DDH (trade name) manufactured by Otsuka Chemical Co., Ltd. etc. can be exemplified.

[0099] In the curable composition of the embodiment of the present invention, with respect to every 100 parts by mass of the epoxy resin, for example, 1 to 30 parts by mass of (C) latent curing agent can be contained, preferably 2 to 25 parts by mass of (C) latent curing agent is contained, more preferably 3 to 20 parts by mass of (C) latent curing agent is contained, and further preferably 4 to 15 parts by mass of (C) latent curing agent is contained.

[0100] In the curable composition of the embodiment of the present invention, when 1 to 30 parts by mass of (C) latent curing agent is contained with respect to every 100 parts by mass of the epoxy resin, the curability and storage stability are more balanced.

[0101] In this specification, the (D) filler means a compound that can increase the amount of the curable composition of the embodiment of the present invention and can impart a certain strength to the cured product formed from the curable composition, and can contribute to viscosity adjustment or weight reduction as the case may be. As long as the curable composition required by the present invention is obtained, there is no particular limitation.

[0102] As a filler material, for example, carbonates and sulfates of alkaline earth metals such as calcium carbonate (heavy calcium carbonate, precipitated calcium carbonate, surface-treated calcium carbonate, etc.), magnesium carbonate, barium sulfate, mica, graphite, talc, clay, glass flakes (glass beads), vermiculite, kaolin, wollastonite (acicular calcium metasilicate), silicon dioxide, diatomaceous earth, gypsum, cement, converter slag, white sand, zeolite, cellulose powder, powdered rubber, xonotlite, potassium titanate, bentonite, aluminum nitride, silicon nitride, zinc oxide, titanium oxide, aluminum oxide, zinc oxide, iron oxide, magnesium oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, calcium silicate can be exemplified. In addition, there are calcium carbonate whiskers (acicular calcium carbonate), ceramic short fibers or their whiskers, asbestos short fibers, glass fiber short fibers, potassium titanate short fibers, calcium silicate short fibers, aluminum silicate, carbon fiber short fibers, aromatic polyamide short fibers, sepiolite and other mineral fibers, various whiskers and other fibrous fillers, glass balloons, silicon dioxide balloons, resin balloons, carbon inorganic hollow spheres and other hollow fillers, organic hollow fillers such as plastic balloons composed of organic synthetic resins such as vinylidene chloride and acrylonitrile, metal fillers such as aluminum fillers, etc.

[0103] (D) The filler material preferably contains acicular filler materials with a length of 0.4 mm or more, more preferably contains acicular filler materials with a length of 0.4 mm or more and 40 mm or less, further preferably contains acicular filler materials with a length of 5 mm or more and 30 mm or less, and even more preferably contains acicular filler materials with a length of 6 mm or more and 20 mm or less.

[0104] (D) When the filler material contains acicular filler materials with a length of 0.4 mm or more, the anti-deformation property of the curable composition of the embodiment of the present invention can be further improved.

[0105] (D) The filler material preferably contains inorganic filler materials with an aspect ratio (L / D) of 4 or more, more preferably contains inorganic filler materials with an aspect ratio (L / D) of 4.5 or more and 20 or less, and further preferably contains inorganic filler materials with an aspect ratio (L / D) of 5 or more and 15 or less.

[0106] When the (D) filler material contains inorganic filler materials with an aspect ratio (L / D) of 4 or more, the anti-deformation property of the curable composition of the embodiment of the present invention can be further improved.

[0107] In addition, the inorganic filler materials can be exemplified by the filler materials obtained by removing organic filler materials (for example, asbestos short fibers, aromatic polyamide fiber short fibers, hollow fillers such as resin balloons, organic hollow fillers such as plastic balloons composed of organic synthetic resins such as vinylidene chloride and acrylonitrile) from the above examples of filler materials.

[0108] In the curable composition according to an embodiment of the present invention, with respect to every 100 parts by mass of the curable composition, for example, 20 to 70 parts by mass of the (D) filler may be contained, preferably 35 to 65 parts by mass of the (D) filler are contained, more preferably 30 to 60 parts by mass of the (D) filler are contained, and still more preferably 35 to 55 parts by mass of the (D) filler are contained.

[0109] In the curable composition according to an embodiment of the present invention, when 20 to 70 parts by mass of the (D) filler is contained with respect to every 100 parts by mass of the curable composition, the anti-deformation property can be further improved.

[0110] In this specification, the (E) foaming agent refers to a substance added to increase the volume in the material, for example, a substance added to generate foam, for example, a substance that generates gas by decomposition or a substance that becomes a gas itself, and there is no particular limitation as long as the curable composition of the present invention can be obtained.

[0111] Since the curable composition according to an embodiment of the present invention contains a foaming agent, the thickness after curing can be increased more effectively, thereby improving the reinforcing property. In addition, by foaming, the elastic modulus of the cured product (i.e., the reinforcing material) obtained by curing the curable composition can be reduced, and the strain can also be reduced.

[0112] As the (E) foaming agent, for example, a foaming agent that foams by heating is preferred, and inorganic foaming agents and organic foaming agents can be exemplified.

[0113] As the inorganic foaming agents, for example, ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium borohydride, and azide compounds can be exemplified.

[0114] As the organic foaming agents, n-nitroso compounds, azo compounds (for example, azodicarbonamide; ADCA, etc.), fluorinated alkanes, hydrazine compounds (for example, 4,4'-oxybis(benzenesulfonylhydrazide): OBSH, etc.), semicarbazide compounds, triazole compounds, etc. can be exemplified.

[0115] In addition, thermally expandable particles (unexpanded balloons) in which a thermally expandable substance (for example, isobutane, butane, etc.) is encapsulated in microcapsules made of a thermoplastic resin (for example, polyvinylidene chloride, polyacrylonitrile, poly(meth)acrylate, etc.) can also be exemplified.

[0116] Preferably, the (E) foaming agent contains at least one selected from the group consisting of azo compounds (for example, ADCA-based chemical foaming agents), hydrazine compounds (for example, OBSH-based chemical foaming agents), and unexpanded balloons.

[0117] (E) When the foaming agent is at least one selected from the group consisting of azo compounds (e.g., ADCA-based chemical foaming agents), hydrazine compounds (e.g., OBSH-based chemical foaming agents), and unexpanded balloons, the curable composition according to an embodiment of the present invention can achieve the desired foaming ratio while further increasing the flexural strength and further reducing the strain.

[0118] In the curable composition according to an embodiment of the present invention, with respect to every 100 parts by mass of the curable composition, for example, 0.1 to 10 parts by mass of the (E) foaming material may be contained, preferably 0.2 to 5 parts by mass of the (E) foaming material, more preferably 0.3 to 3 parts by mass of the (E) foaming material, and still more preferably 0.4 to 2 parts by mass of the (E) foaming material.

[0119] In the curable composition according to an embodiment of the present invention, when 0.1 to 10 parts by mass of the (E) foaming material is contained with respect to every 100 parts by mass of the curable composition, more appropriate foaming can be performed, and it is possible to better ensure the reinforcing property while suppressing deformation.

[0120] The curable composition according to an embodiment of the present invention may appropriately contain other components. As other components, for example, ordinary curing agents (excluding the above-mentioned latent curing agents), diluents, surfactants, other additives, etc. may be exemplified.

[0121] In an embodiment of the present invention, the curing agent refers to a compound that does not have a curing effect at normal temperature but exhibits a curing effect at a certain temperature. Except for the above-mentioned latent curing agents, there is no particular limitation as long as the curable composition of the present invention can be obtained.

[0122] In an embodiment of the present invention, the diluent can impart fluidity to the curable composition according to the embodiment of the present invention, and there is no particular limitation as long as the curable composition of the present invention can be obtained.

[0123] As the diluent, for example, hydrocarbon solvents such as paraffin solvents, isoparaffin solvents, naphthene solvents, and aromatic solvents can be exemplified.

[0124] In an embodiment of the present invention, as other additives, for example, a moisture absorbent (calcium oxide, molecular sieve, etc.), a thixotropy imparting agent (organic bentonite, fumed silica, aluminum stearate, metal soaps, castor oil derivatives, etc.), a stabilizer [2,6-di-tert-butyl-4-methylphenol, 2,2-methylenebis(4-methyl-6-tert-butylphenol), nickel dibutyldithiocarbamate, etc.], a curing accelerator (dibutyltin dilaurate, lead octoate, bismuth isooctoate, etc.), a coupling agent such as silane or titanium, a plasticizer, etc. can be exemplified. Other additives are not particularly limited as long as a curable composition achieving the object of the present invention can be obtained, and can be appropriately used.

[0125] The curable composition of the embodiment of the present invention can be produced by mixing the above components.

[0126] The mixing apparatus and method are not particularly limited as long as a curable composition achieving the object of the present invention can be prepared.

[0127] As such a mixing apparatus, specifically, for example, a twin-screw mixer, a planetary mixer, a sigma mixer, a kneader, a grinder, a crusher, a roll, a dissolver, etc. can be used.

[0128] In addition, mixing can be performed using a mixable container, for example, in a tank, a container, etc.

[0129] The curable composition of the embodiment of the present invention can be a one-component type or a two-component type, and generally can be used as a one-component curable composition.

[0130] The curable composition of the embodiment of the present invention can use a known coating method. For example, using coating methods such as bead coating, slit coating, spray coating, swirl coating, shot coating, etc., it can be coated at an arbitrary thickness and coating manner at a necessary place. For example, it can be cured by heating to a predetermined temperature using a hot air circulation drying furnace, etc.

[0131] The curable composition of the embodiment of the present invention can be used as a coating-type one-component curable composition.

[0132] In the above coating means, coating can also be performed by an automatically controlled coating machine or a robotic coating machine controlled by a computer.

[0133] In an embodiment of the present invention, a manufacturing method of an automobile including using the curable composition of the embodiment of the present invention can be provided.

[0134] The curable composition according to an embodiment of the present invention can be used on a production line for manufacturing automobiles to provide a reinforcing layer on a metal plate of an automobile body. That is, a reinforcing layer can be provided, which can be formed by coating the curable composition according to an embodiment of the present invention on a metal plate of an automobile body and heating it to cure. Further, a reinforced metal plate structure and a method for manufacturing the same can be provided, wherein the reinforced metal plate structure is provided with a reinforcing layer formed by coating the curable composition according to an embodiment of the present invention on a metal plate of an automobile body and heating it to cure.

[0135] In addition, a curable composition for reinforcing a metal plate and capable of being pumped out can be provided.

[0136] The viscosity of the curable composition according to an embodiment of the present invention at 40 °C and a shear rate of 430 sec -1 is preferably 50 to 300 Pa·s, more preferably 65 to 250 Pa·s, still more preferably 80 to 200 Pa·s, and even more preferably 90 to 180 Pa·s.

[0137] The viscosity of the curable composition according to an embodiment of the present invention at 40 °C and a shear rate of 430 sec -1 is 50 to 300 Pa·s, the pumpability of the curable composition according to an embodiment of the present invention can be further improved.

[0138] The foaming ratio of the curable composition according to an embodiment of the present invention is preferably 10 to 200%, more preferably 30 to 150%.

[0139] When the foaming ratio of the curable composition according to an embodiment of the present invention is 10 to 200%, the reinforcing property and anti-deformation property of the curable composition according to an embodiment of the present invention can be further improved.

[0140] The flexural strength of the cured product of the curable composition according to an embodiment of the present invention is preferably 18 N or more, more preferably 20 to 60 N, still more preferably 22 to 50 N, and even more preferably 24 to 40 N.

[0141] When the flexural strength of the cured product of the curable composition according to an embodiment of the present invention is 18 N or more, the reinforcing property of the curable composition according to an embodiment of the present invention can be further improved.

[0142] The displacement amount (flexure) of the cured product of the curable composition according to an embodiment of the present invention is preferably 4.5 mm or more, more preferably 4.8 to 20 mm, still more preferably 5 to 17 mm, and even more preferably 5.5 to 15 mm.

[0143] When the curvature of the cured product of the curable composition according to the embodiment of the present invention is 4.5 mm or more, the curable composition according to the embodiment of the present invention will not break even under impact, and the reinforcing property can be more ensured.

[0144] The warpage amount of the cured product of the curable composition according to the embodiment of the present invention is preferably 5 mm or less, more preferably -1 to 4 mm, further preferably -0.5 to 3.5 mm, and even more preferably 0 to 3 mm.

[0145] When the warpage amount of the cured product of the curable composition according to the embodiment of the present invention is 5 mm or less, the curable composition according to the embodiment of the present invention can further suppress the deformation of the reinforcing panel.

[0146] The elastic modulus of the cured product of the curable composition according to the embodiment of the present invention is preferably 1000 to 3000 MPa, more preferably 1100 to 2500 MPa, further preferably 1200 to 2000 MPa, and even more preferably 1300 to 1800 MPa.

[0147] When the elastic modulus of the cured product of the curable composition according to the embodiment of the present invention is 1000 to 3000 MPa, the reinforcing property of the curable composition according to the embodiment of the present invention can be further improved.

[0148] The Tg of the cured product of the curable composition according to the embodiment of the present invention is preferably 40 to 140 °C, more preferably 50 to 120 °C, further preferably 60 to 100 °C, and even more preferably 70 to 95 °C.

[0149] When the Tg of the cured product of the curable composition according to the embodiment of the present invention is 40 to 140 °C, the reinforcing property of the curable composition according to the embodiment of the present invention can be further improved.

[0150] Examples

[0151] Hereinafter, the present invention will be described more specifically and in detail by way of examples and comparative examples. However, these examples are merely one mode of the present invention, and the present invention is not limited by any of these examples.

[0152] In addition, in the description of the examples, unless otherwise specified, the part without considering the solvent is used as the basis of parts by weight and weight %.

[0153] The components used in this example are as follows.

[0154] (A) Epoxy resin

[0155] (a1-1) Unmodified bisphenol A type epoxy resin (JER828 (trade name) manufactured by Mitsubishi Chemical Corporation)

[0156] (a1-2) Unmodified bisphenol A epoxy resin (JER1001 (trade name) manufactured by Mitsubishi Chemical Corporation)

[0157] (a1-3) Unmodified bisphenol F epoxy resin (JER807 (trade name) manufactured by Mitsubishi Chemical Corporation)

[0158] (a2-1) Low-viscosity epoxy resin, with an epoxy equivalent of 430 and a viscosity of 600 mPa·s at 25°C, dimer acid type diglycidyl ester (JER871 (trade name) manufactured by Mitsubishi Chemical Corporation)

[0159] (a2-2) Polyoxyalkylene bisphenol A glycidyl ether, with an epoxy equivalent of 340 and a viscosity of 2600 mPa·s at 25°C (Glycidyl BPP-350 (trade name) manufactured by Sanyo Chemical Industries, Ltd.)

[0160] (a2-3) Bifunctional epoxy resin used as a reactive diluent, with an epoxy equivalent of 296 and a viscosity of 43 mPa·s at 25°C, (PP-300P (trade name) manufactured by Sanyo Chemical Industries, Ltd.)

[0161] (a3-1) Elastomer-modified epoxy resin, (bisphenol A epoxy resin modified with 40% elastomer content), with an epoxy equivalent of 340 and a viscosity of 190,000 mPa·s at 25°C (Hypro RA840 (trade name) manufactured by CVC Thermoset Specialies)

[0162] (B) Solid form rubber

[0163] (b1-1) Styrene-butadiene-divinylbenzene copolymer (EMULPRENE 1009 (trade name) manufactured by INDUSTRIAS NEGROMEX S.A.DE C.V.)

[0164] (b2-1) Styrene-butadiene copolymer (Nipol1502 (trade name) manufactured by Zeon Corporation, Japan)

[0165] (b3-1) Acrylonitrile-butadiene copolymer (DN214 (trade name) manufactured by Zeon Corporation, Japan)

[0166] (b3-2) Acrylonitrile-butadiene copolymer (DN219 (trade name) manufactured by Zeon Corporation, Japan)

[0167] (C) Latent curing agent

[0168] (c1) Dicyandiamide (OMICURE DDA 10 (trade name) manufactured by CVC Thermoset Specialities)

[0169] (c2) 3-(3,4-Dichlorophenyl)-1,1-dimethylurea (Dyhard UR-200 (trade name) manufactured by Alzchem)

[0170] (D) Filler

[0171] (d1) Carbon black (High Black #20 (trade name) manufactured by Asahi Carbon Co., Ltd.)

[0172] (d2) Glass balloons (Glass Bubbles S-38 (trade name) manufactured by 3M Company)

[0173] (d3) Filler (Whiten B (trade name) manufactured by Bihoku Funboku Kogyo Co., Ltd.)

[0174] (d4) Filler (Hakenca CCR (trade name) manufactured by Shiraishi Kogyo Co., Ltd.)

[0175] (d5) Calcium metasilicate, L / D ratio > or = 5 (Nyad G (trade name) manufactured by NYCO MINERALS, Inc.)

[0176] (E) Foaming agent

[0177] (e1) Foaming agent, (Vinyl Pore AC#R (trade name) manufactured by Yonghe Chemical Industry Co., Ltd.)

[0178] (e2) Foaming agent, (New Cellulose #1000M (trade name) manufactured by Yonghe Chemical Industry Co., Ltd.)

[0179] (e3) Foaming agent, (Expensell 920-80 (trade name) manufactured by Nippon Fillite Co., Ltd.)

[0180] (F) Additive

[0181] (f1) Additive, calcium oxide, QC-X (trade name) manufactured by Inoue Lime Industry Co., Ltd.

[0182] These components were mixed in the mass parts shown in Table 1 to produce the one-component curable compositions of Examples 1 to 4 and Comparative Example 1.

[0183] For each of the above curable compositions (or their cured products), viscosity, spray resistance, foaming ratio, flexural strength, displacement amount (flexure), warpage amount, elastic modulus, and Tg were measured by the following methods and evaluated. The results are shown in Table 1.

[0184] Viscosity measurement

[0185] Using a pressure-type apparent viscometer, the viscosity of the curable composition was measured in accordance with JASO 323-77. The curable composition was filled in the cylinder of the viscometer, and the temperature was adjusted to 40 °C using a jacket or the like. It was confirmed to be 40 °C. A capillary tube No. 3 (length: 74.1 mm, capillary diameter: 1.85 mm) was used. The shear rate was measured at 430 s -1 The viscosity range in which the curable composition can be coated is considered to be 300 Pa·s or less. Therefore, the viscosity of the curable composition is preferably 50 Pa·s or more and 300 Pa·s or less.

[0186] Spray resistance

[0187] On a SPCC-SD steel plate of 200×300×0.8 mm, the curable composition was coated to 150×200×1.8 mm to prepare a test piece. A spray with a water temperature of 50 °C, an angle of 45 degrees, and a water pressure of 490 kPa was sprayed onto the surface of the test piece coated with the curable composition. The distance from the spray nozzle to the test piece was 700 mm, and the spray time was 1 minute. After spraying, the coated surface was visually observed to confirm whether there was peeling or displacement of the curable composition. The evaluation criteria for spray resistance are as follows.

[0188] ◎: The curable composition has no peeling or displacement at all.

[0189] ○: The curable composition has no peeling or displacement.

[0190] ○△: The curable composition has very slight peeling or displacement, but it is not a problem.

[0191] △: The curable composition has a little peeling or displacement, but it is not a problem in practice.

[0192] △×: The curable composition has a little peeling or displacement, which becomes a problem in practice.

[0193] ×: The curable composition has obvious peeling or displacement.

[0194] Expansion ratio

[0195] The curable composition was coated in beads on an aluminum plate of 3×7 cm to prepare a test specimen. For the test specimen, measurement was carried out according to the water displacement method (refer to JASO 323-77 specific gravity test method A), and the expansion ratio was calculated from the density (specific gravity) before and after curing of the curable composition.

[0196] Expansion ratio (%) = (reciprocal of density after curing - reciprocal of density before curing) ÷ reciprocal of density before curing × 100

[0197] The test piece was placed in a forced circulation oven, and the curable composition was cured at 180°C for 25 minutes. From the viewpoints of the reinforcement and curing strain of the cured product of the curable composition, the foaming ratio is preferably 10 to 200%, more preferably 30 to 150%.

[0198] Flexural strength and displacement amount (flexure)

[0199] The curable composition was coated on a SPCC-SD steel plate of 25×200×0.8 mm to a thickness of 1.8 mm, and then the coated steel plate was placed in a forced circulation oven, and the curable composition was cured at 180°C for 25 minutes to obtain a test piece. Using a flexural strength test device specified in JIS K6911, a three-point bending test of this test piece was carried out under the conditions of a support span of 100 mm and a loading speed of 1 mm / min, and the load (N / 25 mm) at a displacement of 1 mm and the displacement amount at the maximum load were determined, and the flexural strength and flexure were measured. Considering the dent resistance of an actual vehicle, the load (flexural strength) at a displacement of 1 mm is preferably 18 N or more, and the displacement amount (flexure) at the maximum load is preferably 4.5 mm or more.

[0200] Warpage amount

[0201] The curable composition was coated on a SPCC-SD steel plate of 25×200×0.8 mm to a thickness of 1.8 mm, and then the coated steel plate was placed in a forced circulation oven, and the curable composition was cured at 180°C for 25 minutes to obtain a test piece. A 1 kg·f weight was placed on one side of this test piece, and the warpage height (mm) on the other side was determined. Considering the warpage amount that does not cause appearance defects in an actual vehicle, it is preferably 5 mm or less.

[0202] Elastic modulus and Tg

[0203] The curable composition was coated on a 0.8 mm aluminum plate that had been subjected to a release treatment such as Teflon (registered trademark) processing so that the cured thickness was 1 to 2 mm, and then the coated test piece was placed in a forced circulation oven, and the curable composition was cured at 180°C for 25 minutes to obtain a cured product. The size of the cured product was processed to a width of 5 mm and a length of 50 mm, and using a dynamic viscoelasticity measurement (DMA) device, the elastic modulus and tanδ were measured in the range from -50 to 150°C at a heating rate of 2°C / min. The elastic modulus at 23°C and the temperature Tg indicating the peak position of tanδ were recorded. From the viewpoints of the dent resistance and the use temperature environment of an actual vehicle, it is preferably to satisfy both the elastic modulus: 1000 to 3000 MPa and Tg: from 40°C to 140°C at the same time.

[0204] [Table 1]

[0205]

[0206] [Table 2]

[0207]

[0208] [Table 3]

[0209]

[0210] The curable compositions and their cured products of Examples 1 to 12 can be used as a one - component curable composition that can be pumped out and is used for reinforcing metal plates. This one - component curable composition can improve the reinforcing property while suppressing deformation, and can improve the spray resistance while maintaining the pumpability.

[0211] The curable compositions and their cured products of Comparative Examples 1 to 5 can neither improve the reinforcing property while suppressing deformation nor improve the spray resistance while maintaining the pumpability, and cannot be said to be sufficient as a one - component curable composition for coating.

[0212] Industrial Applicability

[0213] The one - component curable composition according to the embodiment of the present invention can improve the reinforcing property while suppressing deformation, and can improve the spray resistance while maintaining the pumpability. In addition, this one - component curable composition can be suitably coated on a metal plate and can be suitably used as a coated - type metal plate reinforcing material.

[0214] In addition, this application claims priority based on Article 4 of the Paris Convention on the basis of the application No. 2022 - 175739 filed in Japan on November 1, 2022. The content of the basic application is incorporated into the specification of this application by reference.

Claims

1. A one - component curable composition, which contains (A) an epoxy resin, (B) a solid - state rubber, (C) a latent curing agent, (D) a filler, and (E) a foaming agent. Among them, (A) The epoxy resin contains (A1) an unmodified bisphenol - type epoxy resin. In the one - component curable composition, relative to every 100 parts by mass of (A) the epoxy resin, 10 - 100 parts by mass of (B) the solid - state rubber is contained. (B) The solid - state rubber contains (B1) a styrene - butadiene - divinylbenzene copolymer.

2. The one - component curable composition according to claim 1, Among them, At 40 °C and a shear rate of 430 sec -1 the viscosity is 50 to 300 Pa·s.

3. The one - component curable composition according to claim 1, Among them, (A) The epoxy resin contains 25 - 90% by mass of (A1) the unmodified bisphenol - type epoxy resin based on 100% by mass of the epoxy resin.

4. The one - component curable composition according to claim 1, Among them, (A) The epoxy resin contains 15 - 40% by mass of aromatic rings based on 100% by mass of the epoxy resin.

5. The one - component curable composition according to claim 1, Among them, (E) The foaming agent contains at least one selected from the group consisting of ADCA - type chemical foaming agents, OBSH - type chemical foaming agents, and unexpanded balloons.

6. The one - component curable composition according to claim 1, Among them, The foaming ratio is 10 - 200%.

7. The one - component curable composition according to claim 1, Among them, (D) The filler contains needle - shaped fillers with a length of 0.5 mm or more.

8. The one - component curable composition according to claim 1, Among them, (B) The solid - state rubber further contains (B2) a styrene - butadiene copolymer.

9. The one - component curable composition according to claim 1, Among them, (B) The solid - state rubber further contains (B3) a nitrile - butadiene copolymer.

10. The one - component curable composition according to claim 1, Among them, The acid content of (B1) the solid - state rubber and / or (B2) the solid - state rubber is 0.2 - 8% by mass.

11. The one - component curable composition according to claim 1, Among them, (A) The epoxy resin contains (A2) a low - viscosity epoxy resin. The epoxy equivalent of (A2) the low - viscosity epoxy resin is 250 - 700, and it has a viscosity of 40 - 5000 mPa·s at 25°C.

12. The one - component curable composition according to claim 11, Among them, (A2) The low - viscosity epoxy resin contains (A2 - 1) a diester - type epoxy resin.

13. The one - component curable composition according to claim 1, Among them, (D) The filler contains an inorganic filler with an aspect ratio (L / D) of 5 or more.

14. According to claim 1 of the one - component curable composition, among them The one - component curable composition is a coating - type one - component curable composition.

15. The one - component curable composition according to claim 1, Among them, The one - component curable composition is used for reinforcing metal plates and can be pumped out.

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