JP2002275242A - Low-temperature curable epoxy resin composition and adhesive using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-pack epoxy resin composition suitable also for use at <=5 deg.C and an adhesive using the same. SOLUTION: This low-temperature curing epoxy resin composition comprises (A) an epoxy resin, (B) a trifunctional acryl oligomer and (C) a curing agent for epoxy resins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition excellent in low-temperature curability and an adhesive using the same.

[0002]

2. Description of the Related Art A liquid epoxy resin comprises a main agent and a liquid amine compound and a curing agent such as an acid anhydride.
The two-part epoxy resin composition, which is used by mixing the main agent and the curing agent immediately before, can be cured at room temperature, can be used without solvent,
It is used for applications such as adhesion of members, paints, primers, casting materials, and matrix resins of fiber-reinforced composite materials because of its advantages such as no gas generation during curing and excellent properties of cured products.

[0003] Particularly in the field of civil engineering and construction, bridges, tunnels,
BACKGROUND ART A method using a liquid epoxy resin has been used for repairing concrete structures such as buildings over time, repairing damage caused by earthquakes, and revising seismic standards supposing a larger earthquake. For example, a steel sheet reinforcing method in which a steel sheet is attached to the surface of a reinforcing portion using a resin is known. However, this method has a problem in that the repair / reinforcement portion becomes too heavy, causing breakage or difficulty in the operation.

[0004] As an improvement method thereof, Japanese Patent Laid-Open No. Hei 3-2249 has been proposed.
No. 01 discloses a method of repairing / reinforcing a resin by impregnating a reinforcing fiber impregnated with a resin on the surface of a reinforcing portion.Currently, a two-pack type epoxy resin is used as an impregnating resin.
It is widely applied to repair and reinforcement of concrete structures.

[0005] However, in the repair and reinforcement work for concrete structures, the temperature may drop to 5 ° C or less in winter, and in such a case, the viscosity increases with a normal two-part epoxy resin adhesive, and the curing speed increases. Cannot be used because it is too slow. Further, when a large amount of an epoxy resin-based reactive diluent is used for the purpose of reducing the viscosity of the epoxy resin adhesive, the strength of the cured product is deteriorated. Therefore, when the temperature drops to 5 ° C. or lower, the operation is not performed or the temperature is sensed using a jet heater or the like.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a two-pack type epoxy resin composition suitable for use at 5 ° C. or lower and an adhesive using the same.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, a two-part epoxy resin composition using a trifunctional acrylic oligomer as a diluent has a low viscosity even at 5 ° C. or less. The present invention has been found to have excellent viscosity, excellent curing speed, and excellent cured product strength, and has completed the present invention.

That is, the present invention provides a low-temperature curable epoxy resin composition comprising (A) an epoxy resin, (B) a trifunctional acrylic oligomer, and (C) a curing agent for an epoxy resin.

Here, the tack-free time at 0 ° C. of the low-temperature curable epoxy resin composition is preferably 15 hours or less. Further, the tack-free time at -10 ° C of the low-temperature curable epoxy resin composition is 40.
It is preferably less than or equal to the time.

Further, the present invention provides an adhesive using the low-temperature curable epoxy resin composition.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the low-temperature curable epoxy resin composition of the present invention (hereinafter, also referred to as the composition of the present invention) will be described in detail. The composition of the present invention comprises (A) an epoxy resin, (B) a trifunctional acrylic oligomer,
(C) a curing agent for an epoxy resin.

(A) Epoxy resin The epoxy resin used in the present invention is not particularly limited, and a known epoxy resin can be used.

Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, biphenyl epoxy resin, naphthalene epoxy resin, novolak epoxy resin, epoxy resin having a fluorene skeleton, Epoxy resin, diglycidyl resorcinol, tetrakis (glycidyloxyphenyl) ethane, tris (glycidyloxyphenyl) methane, trisglycidylaminophenol, triglycidylaminocresol, tetraglycidylxylene from a phenol compound and dicyclopentadiene copolymer Examples include glycidylamine type epoxy resins such as diamines, and alicyclic epoxy resins such as vinylcyclohexene diepoxide. Further, an aliphatic epoxy resin such as glycidyl ether composed of a glycerin derivative (dimer or trimer) such as sorbitol polyglycidyl ether or glycerol polyglycidyl ether can also be used. Epoxy resins can be used alone or in combination of two or more.

Above all, it is preferable to use bisphenol A type epoxy resin, bisphenol F type epoxy resin and sorbitol polyglycidyl ether, and it is particularly preferable to use bisphenol F type epoxy resin from the viewpoint of low viscosity and high strength.

(B) Trifunctional acrylic oligomer In the present invention, the trifunctional acrylic oligomer refers to an acrylic oligomer having an average of three acryloyloxy groups (CH ₂ = CHCOO-). Here, having on average means containing at least 90% by weight of a trifunctional acrylic oligomer, and less than 10% by weight of a by-product during synthesis having a different number of functional groups such as a tetrafunctional acrylic oligomer or a bifunctional acrylic oligomer. May be included.

By diluting the composition of the present invention with a trifunctional acrylic oligomer, the composition of the present invention can be adjusted to a desired viscosity without impairing the strength of the cured product.
If the same amount of tetrafunctional acrylic oligomer is used, the desired viscosity cannot be obtained, and the use of a large amount of this lowers the strength of the cured product. In addition, if the bifunctional acrylic oligomer is used in the same amount, the strength of the cured product is reduced. If the amount is smaller than this, the desired viscosity cannot be obtained. Therefore, in the present invention, a trifunctional acrylic oligomer is used because the balance between the viscosity and the strength of the cured product is excellent.

The trifunctional acrylic oligomer used in the present invention includes, for example, the following compounds:

[0018]

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The trifunctional acrylic oligomer may be used alone or in combination of two or more. Among them, it is preferable to use pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane EO-modified triacrylate, and trimethylolpropane PO-modified triacrylate.

The compounding amount of the trifunctional acrylic oligomer may be controlled by the use conditions such as temperature, but is preferably 5 to 50% by weight, more preferably 10 to 45% by weight based on the epoxy resin (A). preferable. When used in this ratio, the balance between the viscosity and the strength of the cured product is particularly excellent even under the condition of 5 ° C. or less.

(C) Curing Agent for Epoxy Resin The curing agent for epoxy resin is not particularly limited, and a known one can be used. In the present invention, in particular, amine-based curing agents, acid or acid anhydride-based curing agents, basic active hydrogen compounds, imidazoles, polymercaptan-based curing agents, phenol resins, urea resins, melamine resins, isocyanate-based curing agents, and the like Is mentioned.

Specific examples of the amine curing agent include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, iminobispropylamine, bis (hexamethylene) triamine, 1,3,6-trisamino. Polyamines such as methylhexane; polymethylenediamines such as trimethylhexamethylenediamine, polyetherdiamine and diethylaminopropylamine; mensendiamine (MDA), isophoronediamine (IPDA), bis (4-amino-3-methylcyclohexyl) methane , N
-Aminoethylpiperazine (N-AEP), diaminodicyclohexylmethane, bisaminomethylcyclohexane, 3,9-bis (3-aminopropyl) -2,4,
8,10-tetraoxaspiro (5.5) undecane,
Cyclic aliphatic polyamines such as diamines having a norbornane skeleton represented by NBDA manufactured by Mitsui Toatsu Chemicals; aliphatic polyamines containing an aromatic ring such as meta-xylylenediamine (MXDA); metaphenylenediamine, diaminodiphenylmethane, diamino Examples thereof include aromatic polyamines such as diphenylsulfone and diaminodiethyldiphenylmethane, and derivatives thereof.

Amine adduct (polyamine epoxy resin adduct), polyamine-ethylene oxide adduct, polyamine-propylene oxide adduct, cyanoethylated polyamine, ketimine which is a reaction product of aliphatic polyamine and ketone; linear diamine, tetramethylguanidine , Triethanolamine, piperidine, pyridine, benzyldimethylamine, picoline, 2- (dimethylaminomethyl) phenol, dimethylcyclohexylamine, dimethylbenzylamine, dimethylhexylamine, dimethylaminophenol, dimethylamino p
-Cresol, N, N'-dimethylpiperazine, piperidine, 1,4-diazadicyclo (2,2,2) octane, 2,4,6-tris (dimethylaminomethyl) phenol, 1.8-diazabicyclo (5.4 0.0) Secondary amines or tertiary amines such as undecene-1 or liquid polyamide obtained by reacting dimer acid with a polyamine such as diethylenetriamine or triethylenetetramine.

Specific examples of the acid or acid anhydride-based curing agent include polycarboxylic acids such as adipic acid, azelaic acid and decanedicarboxylic acid, phthalic anhydride, trimellitic anhydride, ethylene glycol bis (anhydrotrimellitate). ), Glycerol tris (androtrimellitate), pyromellitic anhydride, aromatic anhydrides such as 3,3 ', 4,4'-benzophenonetetracarboxylic anhydride, maleic anhydride, succinic anhydride, tetrahydroanhydride Phthalic acid, methyltetrahydrophthalic anhydride, methylnadic anhydride, alkenylsuccinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylcyclohexenetetracarboxylic anhydride, methylhymic anhydride, trialkyltetrahydrophthalic anhydride Acid, poly (phenylhexadeca) Cyclic acid anhydride such as diacid) anhydride, polyadipic anhydride, polyazeleic anhydride, polysebacic anhydride, dodecenyl succinic anhydride, poly (ethyl octadecane diacid) anhydride and other aliphatic acid anhydrides Anhydrides, halogenated anhydrides such as chlorendic anhydride, tetrabromophthalic anhydride, and heptonic anhydride.

Specific examples of the basic active hydrogen compound include:
Dicyandiamide, organic acid dihydrazide and the like can be mentioned.

Specific examples of imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole , 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4
-Methylimidazole, 2-methylimidazolium isocyanurate, 2,4-diamino-6- [2-methylimidazoline- (1)]-ethyl-S-triazine,
2,4-diamino-6- [2-ethyl-4-methylimidazoline- (1)]-ethyl-S-triazine and the like.

Specific examples of the polymercaptan-based curing agent include partial epoxy adducts of 2,2'-bismercaptoethyl ether, pentaerythritol tetrathioglycolate, dipentaerythritol hexathioglycolate, and trimethylolpropandolithioglycol. And esters containing a mercapto group such as polysulfide rubber having a mercapto group at the end, and the like.

Specific examples of the isocyanate-based curing agent include isocyanate compounds such as toluene diisocyanate, hexamethylene diisocyanate, and xylene diisocyanate, and blocked isocyanate compounds obtained by reacting an isocyanate group with phenol, alcohol, caprolactam, or the like and masking the same. No.

The curing agent for the epoxy resin may be used alone or in combination.
More than one kind can be used in combination, but among the above, from the viewpoint of curability and strength, MXDA, IPDA, NBD
A and their derivatives are preferably used. In particular, MXDA, IPDA, NBDA
Are preferred.

The compounding amount of the curing agent for the epoxy resin is (A)
20 to 80% by weight based on the epoxy resin is preferable,
0 to 70% by weight is more preferable, and 30 to 60% by weight is particularly preferable. When used in this ratio, the curing rate under 5 ° C. or less is excellent.

The composition of the present invention may further contain an epoxy resin-based reactive diluent in addition to the above essential components.

The epoxy resin-based reactive diluent is not particularly limited as long as it is an epoxy compound other than the above-mentioned epoxy resin, and various known epoxy resins such as monoepoxide compounds, diepoxide compounds and trialepoxide compounds can be used.

Specific examples include diglycidyl ether, (poly) ethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, 2-ethylhexyl glycidyl ether, and alcohol glycidyl ether. Epoxy resin-based reactive diluents can be used alone,
More than one species may be used in combination.

Among them, from the viewpoints of dilutability and reactivity,
It is preferable to use 6-hexane diglycidyl ether and ethylene glycol glycidyl ether.
Hexane diglycidyl ether is more preferred.

The epoxy resin-based reactive diluent is preferably 5 to 40% by weight based on the epoxy resin (A).
30% by weight is more preferred, and 10-20% by weight is particularly preferred. When used in this ratio, the balance between the viscosity and the strength of the cured product is particularly excellent even under the condition of 5 ° C. or less.

Further, the composition of the present invention may optionally contain a curing accelerator. Examples of the curing accelerator include phosphites and tertiary amines, and the curing accelerator may be used alone or in combination of two or more. Among them, tertiary amines are preferably used in terms of easy handling.

Examples of the phosphites include triphenyl phosphite, tris (nonylphenyl) phosphite, triethyl phosphite, tributyl phosphite, tris (2-ethylhexyl) phosphite, tridecyl phosphite, and tris (tridecyl) Phosphite, diphenyl mono (2-ethylhexyl) phosphite, diphenyl monodecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyl dipropylene glycol diphosphite, tetraphenyl tetra (tridecyl) pentaerythritol tetra phosphite, trilauryl Trithiophosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, tristearylphosphite Fight, distearyl pentaerythritol diphosphite, tris (2,4-di -
Triesters such as t-butylphenyl) phosphite and hydrogenated bisphenol A / pentaerythritol phosphite polymer are exemplified. Further, di- or monoesters obtained by partially hydrolyzing these triesters can also be used.

As the tertiary amine, benzylmethylamine, triethylamine, dimethylaminomethylphenol, trisdimethylaminomethylphenol, 1,8-
Diazabicyclo [5.4.0] undecene-1,1,4
-Diazabicyclo [2.2.2] octane and the like.

The composition of the present invention may also contain an acid catalyst to promote curing. Examples of the acid catalyst include sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, and n-butylphosphoric acid. Among these, p-toluenesulfonic acid is preferred in terms of easy handling.

Further, the composition of the present invention may contain various additives as required. For example, fillers, plasticizers, thixotropic agents, pigments, dyes,
Examples include an antioxidant, an antioxidant, an antistatic agent, a flame retardant, an adhesion-imparting agent, and a solvent.

As the filler, those having various shapes can be used. For example, fumed silica, calcined silica, precipitated silica, pulverized silica, fused silica; diatomaceous earth; iron oxide, zinc oxide, titanium oxide , Barium oxide, magnesium oxide; calcium carbonate, magnesium carbonate,
Organic carbonates and inorganic fillers such as zinc carbonate; limestone clay, kaolin clay and calcined clay; carbon black; and fatty acid, resin acid and fatty acid ester-treated products thereof.

As a plasticizer, dioctyl phthalate,
Dibutyl phthalate; dioctyl adipate, isodecyl succinate; diethylene glycol dibenzoate, pentaerythritol ester; butyl oleate, methyl acetyl ricinoleate; tricresyl phosphate, trioctyl phosphate; propylene glycol adipate polyester, butylene glycol adipate polyester; Can be

Examples of the antioxidant include butylhydroxytoluene and butylhydroxyanisole.
Examples of the anti-aging agent include hindered phenol compounds.

As the pigment, titanium dioxide, zinc oxide,
Examples thereof include inorganic pigments such as ultramarine, red iron, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, and sulfate, and organic pigments such as azo pigments and copper phthalocyanine pigments.

Examples of the thixotropic agent include aerosil (manufactured by Nippon Aerosil Co., Ltd.), disparone (manufactured by Kusumoto Kasei Co., Ltd.), calcium carbonate, and Teflon (registered trademark). As an antistatic agent, generally,
Examples thereof include quaternary ammonium salts and hydrophilic compounds such as polyglycol and ethylene oxide derivatives.

Examples of the adhesion-imparting agent include terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins and the like.

Examples of the flame retardant include chloroalkyl phosphate, dimethyl methyl phosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, and brominated polyether.

The method for producing the composition of the present invention is not particularly limited, but (A) an epoxy resin, (B) a trifunctional acrylic oligomer, and, if necessary, an epoxy resin-based diluent and other additives are added under reduced pressure. The mixture may be sufficiently kneaded using a stirrer such as a mixing mixer or the like, and uniformly dispersed to prepare a main agent, and (C) a curing agent for epoxy resin may be mixed at the time of use.

The composition of the present invention thus produced has a tack free time (TFT) at 0 ° C. of 15
The time is preferably not more than 12 hours, more preferably not more than 12 hours, and particularly preferably not more than 10 hours. Further, as the composition of the present invention, the TFT at −10 ° C. is preferably 40 hours or less, more preferably 36 hours or less, and particularly preferably 24 hours or less. In particular, the composition of the present invention has a TFT at 0 ° C. of 15 hours or less, and
It is particularly preferable that the TFT at -10 ° C be 40 hours or less. In this specification, a TFT is
After mixing (A) an epoxy resin and (B) a main component having a trifunctional acrylic oligomer as an essential component, and (C) a curing agent for an epoxy resin, the surface of the composition is touched with a finger until the stringing disappears. Time.

As described above, the composition of the present invention has a low viscosity even at a low temperature of 5 ° C. or less, is easy to use, has an excellent curing speed, and has an excellent strength of the cured product. is there. Accordingly, the composition of the present invention can be used for various adhesives,
It is suitable as a casting material and a fiber-reinforced composite material, and particularly suitable as an adhesive for repairing and reinforcing concrete structures.

[0051]

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the following examples.

Examples 1 and 2 The components of the main ingredient were blended under reduced pressure at the ratios shown in Table 1 and thoroughly stirred with a mixing mixer until uniform. After preparing the main agent, use a BE type viscometer (using rotor # 7),
The viscosity at 0 ° C. (mPa · s) was measured.

After the measurement of the viscosity, the curing agent was added at the ratio shown in Table 1, and the mixture was stirred until it became uniform to obtain a composition. After curing the obtained composition at 20 ° C. for one week, the compressive strength (N / mm ² ) was measured according to JIS K7208.

Comparative Examples 1, 2, 3, 4 In the same manner, the viscosity of the base material and the compressive strength of the cured product were measured. Table 1 shows the results.

[0055]

[Table 1]

The following components were used in Table 1. Epoxy resin: Epicoat 828 (manufactured by Yuka Shell Epoxy) Trifunctional acrylic oligomer 1: Aronix M305
(Toagosei Co., Ltd.) Trifunctional acrylic oligomer 2: Aronix M309
(Toagosei Co., Ltd.) 4-functional acrylic oligomer: Aronix M400 (Toagosei Co., Ltd.) Bifunctional acrylic oligomer: Aronix M220 (Toagosei Co., Ltd.) Epoxy resin-based reactive diluent: ED503 (Asahi Denka Industrial Co., Ltd.) Curing agent for epoxy resin: W1000 (manufactured by Sanwa Chemical Industry Co., Ltd.)

Table 1 shows that the compositions of the examples have an excellent balance between the viscosity and the compressive strength of the cured product.

Example 3 In the same manner as in Examples 1 and 2, the viscosity of the base material and the compressive strength of the cured product were measured. Further, the obtained composition is applied to a mortar in a thickness of 1 mm, and a TFT at 0 ° C. or −10 ° C.
(H) was measured. For the TFT (h), after mixing the main agent and the curing agent, the surface of the composition was touched with a finger and the time until stringing disappeared.

Comparative Examples 5 and 6 In the same manner as in Example 3, the viscosity of the base material, the compressive strength of the cured product, and the TFT were measured. Table 2 shows the results.

[0060]

[Table 2]

The components shown in Table 2 were the same as those shown in Table 1. In Table 2, "-" indicates that the sample had no inflection point due to low strength.

From Table 2, it can be seen that the composition of the example has an excellent balance between viscosity and compressive strength and cures at low temperature in a short time.

Further, the compositions of Example 3 and Comparative Examples 1 and 5 were subjected to JIS K6251 (Dumbbell 1).
Dumbbell breaking strength (N / mm) immediately after mixing the curing agent (initial stage) and after immersing in a 50 ° C. hot water bath for 7 days (water resistance) according to the following formula (tensile speed: 5 mm / min).
² ) was measured. Table 3 shows the results.

[0064]

[Table 3]

The components shown in Table 3 were the same as those shown in Table 1.

As can be seen from Table 3, the composition of the present invention has a small decrease in breaking strength and is excellent in balance with viscosity.

[0067]

The composition of the present invention has a low viscosity even at a temperature of 5 ° C. or less, has an excellent curing speed, and has a high strength of the cured product. Therefore, the composition of the present invention, various adhesives,
It is suitable as a casting material, a matrix resin of a fiber reinforced composite material, and the like, particularly as an adhesive for repairing and reinforcing concrete structures.

Continued on the front page F-term (reference) 4J002 CD011 CD021 CD041 CD051 CD061 CD131 EF067 EH046 EL137 EL147 EN037 EN047 EN067 EQ027 ER007 ER027 ET007 EU047 EU077 EU117 EU137 EU196 EV067 EV217 FD010 FD020 FD070 FD090 FD01 AFD01 FD090 FD100 DB15 DC02 DC41 FA10 FA12 4J040 EC031 EC061 EC071 EC081 EC121 EC171 EC261 FA141 FA171 FA281 JA13 JB11 KA16 LA05

Claims (4)

[Claims] 1. A low-temperature curable epoxy resin composition comprising (A) an epoxy resin, (B) a trifunctional acrylic oligomer, and (C) a curing agent for an epoxy resin. 2. The low-temperature curable epoxy resin composition according to claim 1, wherein the tack-free time at 0 ° C. is 15 hours or less. 3. Tack free time at -10 ° C. is 4
The low-temperature curable epoxy resin composition according to claim 1 or 2, wherein the time is 0 hour or less. 4. An adhesive using the low-temperature curable epoxy resin composition according to claim 1.