JP2022185534A - adhesive composition - Google Patents

Abstract

To provide an adhesive composition which can generate a cured product having excellent compression strength and impact resistance.SOLUTION: An adhesive composition can generate a cured product cured by moisture contained in air or the like and having excellent compression strength and impact resistance due to containing 100 pts.mass of an epoxy resin, 1-20 pts.mass of a phenyl type monoglycidyl ether, 10-200 pts.mass of a calcium carbonate treated with a fatty acid, and 10-50 pts.mass of a ketimine compound.SELECTED DRAWING: None

Description

The present invention relates to adhesive compositions.

2. Description of the Related Art Conventionally, on the surface of a concrete structure such as a tunnel wall surface, defective portions called junkers may occur due to factors such as material separation and insufficient compaction when concrete is poured.

Junkers formed in a concrete structure, if left unattended, adversely affect the durability of the concrete structure, so the junkers are repaired periodically. Conventionally, a two-liquid type epoxy adhesive composition using an amine compound as a curing agent has been used for repairing junkers.

However, since the two-liquid type epoxy adhesive composition is used by mixing the epoxy resin and the curing agent at the time of use, the curing of the adhesive composition depends on the accuracy of weighing the epoxy resin and the curing agent and the degree of mixing. However, there is a problem that the properties of the cured product obtained by this method change.

Therefore, Patent Document 1 discloses a one-liquid moisture-curable composition containing an epoxy resin having a predetermined structure, a modified ketimine, a modified silicone resin, a modified silicone resin catalyst, and a dehydrating agent. .

JP 2003-128752 A

However, the cured product produced by curing the one-component moisture-curable composition has the problem of low compressive strength and low impact resistance. is desired.

The present invention provides an adhesive composition capable of producing cured products having excellent compressive strength and impact resistance.

The adhesive composition of the present invention contains 100 parts by mass of an epoxy resin, 1 to 20 parts by mass of phenyl-type monoglycidyl ether, 10 to 200 parts by mass of fatty acid-treated calcium carbonate, and 10 to 50 parts by mass of a ketimine compound.

[Epoxy resin]
The adhesive composition contains an epoxy resin. Epoxy resins contain a plurality of epoxy groups in the molecule. The epoxy resin is not particularly limited, and includes bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetraglycidyldiaminodiphenylmethane type epoxy resin, aminophenol type epoxy resin, aniline type epoxy resin, and benzylamine type epoxy resin. Epoxy resins containing aromatic rings such as epoxy resins, xylenediamine-type epoxy resins, hydrogenated products thereof, glycidyl ester-type epoxy resins, novolac-type epoxy resins, urethane-modified epoxy resins, meta-xylene diamine, hydantoin, etc. Nitrogen epoxy resins, rubber-modified epoxy resins containing polybutadiene skeletons or NBR skeletons, and the like are included. Bisphenol A type epoxy resins and bisphenol F type epoxy resins are preferred because the cured adhesive composition has excellent compressive strength and impact resistance. The epoxy resins may be used alone or in combination of two or more.

The epoxy resin is generally a product obtained by adding epichlorohydrin to the hydroxyl group of a polyhydric alcohol such as polyhydric phenol (for example, in the following formula (1), the number of repetitions n = 0), or It has repeating units formed by ring-opening addition of epichlorohydrin to a hydric alcohol (for example, in the following formula (1), the repeating number n is a natural number).

When the epoxy resin is a bisphenol A type epoxy resin (for example, a reaction product of bisphenol A and epichlorohydrin), it has the structural formula shown below. However, the repetition number n is 0 or a natural number.

[Phenyl monoglycidyl ether]
The adhesive composition contains a phenyl-type monoglycidyl ether. A phenyl-type monoglycidyl ether has a phenyl group in the molecule and only one glycidyl group. A phenyl-type monoglycidyl ether has only one epoxy group in the molecule.

When the adhesive composition contains a phenyl-type monoglycidyl ether, the adhesive composition has excellent fluidity and excellent coatability. Furthermore, the impact resistance and compression strength of the cured product of the adhesive composition can be improved.

The phenyl-type monoglycidyl ether is not particularly limited, and examples thereof include 2,3-epoxypropylphenyl ether, 2-phenylphenol glycidyl ether, methylphenol monoglycidyl ether, ethylphenol monoglycidyl ether, butylphenol monoglycidyl ether, and the like. 2-Phenylphenol glycidyl ether and 2,3-epoxypropylphenyl ether are preferred, and 2-phenylphenol glycidyl ether is more preferred, since they improve the impact resistance and compressive strength of the cured product of the adhesive composition. The phenyl-type monoglycidyl ethers may be used alone or in combination of two or more.

In the adhesive composition, the content of the phenyl-type monoglycidyl ether is 1 part by mass or more, preferably 2 parts by mass or more, more preferably 3 parts by mass or more, relative to 100 parts by mass of the epoxy resin. The content of the phenyl-type monoglycidyl ether is 20 parts by mass or less, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and more preferably 8 parts by mass or less based on 100 parts by mass of the epoxy resin. When the phenyl-type monoglycidyl ether is 1 part by mass or more, the impact resistance and compression strength of the cured product of the adhesive composition are improved, and the coatability of the adhesive composition is improved. When the phenyl-type monoglycidyl ether is 20 parts by mass or less, the cured product of the adhesive composition has improved compressive strength and impact resistance.

[Fatty acid-treated calcium carbonate]
The adhesive composition contains fatty acid-treated calcium carbonate. By containing the fatty acid-treated calcium carbonate in the adhesive composition, the impact resistance of the cured product of the adhesive composition can be improved.

The adhesive composition contains phenyl-type monoglycidyl ether and fatty acid-treated calcium carbonate, and the phenyl-type monoglycidyl ether reduces the viscosity of the adhesive composition and uses fatty acid-treated calcium carbonate with excellent dispersibility. By highly dispersing the fatty acid-treated calcium carbonate in the adhesive composition and further incorporating the phenyl-type monoglycidyl ether into the crosslinked structure of the cured product of the adhesive composition, the cured product of the adhesive composition is excellent. In addition to imparting mechanical strength, flexibility is imparted to the crosslinked structure of the cured product of the adhesive composition. Therefore, it smoothly absorbs compressive stress and impact force applied to the cured adhesive composition, and imparts excellent compressive strength and impact resistance to the cured adhesive composition.

Fatty acid-treated calcium carbonate has its surface treated with a fatty acid. Fatty acids include, for example, saturated fatty acids such as decanoic acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, and icosanoic acid; , icosanoic acid, icosadienoic acid, icosatrienoic acid, icosatetratrienoic acid, and tetradocosanoic acid. Saturated fatty acids are preferred because of their excellent dispersibility in the adhesive composition. The number of carbon atoms in the saturated fatty acid is preferably 8 or more, more preferably 12 or more, more preferably 14 or more, and more preferably 16 or more. The number of carbon atoms in the saturated fatty acid is preferably 30 or less, more preferably 26 or less, more preferably 22 or less, and more preferably 20 or less. The fatty acid-treated calcium carbonate may be used alone or in combination of two or more.

The BET specific surface area of the fatty acid-treated calcium carbonate is preferably 10 m ² /g or more, more preferably 15 m ² /g or more, and even more preferably 20 m ² /g or more. The BET specific surface area of the fatty acid-treated calcium carbonate is preferably 40 m ² /g or less, more preferably 35 m ² /g or less, and even more preferably 30 m ² /g or less. When the BET specific surface area of the fatty acid-treated calcium carbonate is 10 m ² /g or more, the compression strength and impact resistance of the cured product of the adhesive composition can be improved. When the BET specific surface area of the fatty acid-treated calcium carbonate is 40 m ² /g or less, the compression strength and impact resistance of the cured product of the adhesive composition can be improved.

The BET specific surface area of fatty acid-treated calcium carbonate refers to a value measured according to JIS Z8830:2013. For example, the BET specific surface area of fatty acid-treated calcium carbonate can be measured by the one-point method using a BET specific surface area meter commercially available from Yuasa Ionics under the trade name "NOVA2000".

The content of the fatty acid-treated calcium carbonate in the adhesive composition is 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and 40 parts by mass or more with respect to 100 parts by mass of the epoxy resin. It is more preferably 50 parts by mass or more, more preferably 60 parts by mass or more, more preferably 70 parts by mass or more, more preferably 80 parts by mass or more, and more preferably 90 parts by mass or more. The content of the fatty acid-treated calcium carbonate in the adhesive composition is 200 parts by mass or less, preferably 190 parts by mass or less, more preferably 180 parts by mass or less, and 170 parts by mass or less relative to 100 parts by mass of the epoxy resin. More preferably 160 parts by mass or less, more preferably 150 parts by mass or less, more preferably 140 parts by mass or less, more preferably 130 parts by mass or less, more preferably 120 parts by mass or less, more preferably 110 parts by mass or less . When the content of the fatty acid-treated calcium carbonate is 10 parts by mass or more, the impact resistance and compressive strength of the cured product of the adhesive composition can be improved. When the content of fatty acid-treated calcium carbonate is 200 parts by mass or less, the cured product of the adhesive composition has improved compressive strength and impact resistance.

[Ketimine compound]
The adhesive composition contains a ketimine compound. When the adhesive composition contains a ketimine compound, the cured product of the adhesive composition has a high modulus at a low elongation of about 10 to 30%, and can smoothly withstand compressive stress and impact stress. It can absorb and has excellent compressive strength and impact resistance.

A ketimine compound has a ketimine bond (N=C) in the molecule. A ketimine compound has multiple ketimine bonds in the molecule. Ketimine compounds include 2,5,8-triaza-1,8-nonadiene, 2,10-dimethyl-3,6,9-triaza-2,9-undecadiene, 2,10-diphenyl-3,6,9 -triaza-2,9-undecadiene, 3,11-dimethyl-4,7,10-triaza-3,10-tridecadiene, 3,11-diethyl-4,7,10-triaza-3,10-tridecadiene, 2 ,4,12,14-tetramethyl-5,8,11-triaza-4,11-pentadecadiene, 2,4,20,22-tetramethyl-5,12,19-triaza-4,19-tri Eicosadiene, 2,4,15,17-tetramethyl-5,8,11,14-tetraaza-4,14-octadecadiene, 9-(3-butoxy-2-hydroxypropyl)-5,13- Dimethyl-6,9,12-triaza-5,12-heptadecadiene, 1,2-ethylenebis(isopentylideneimine), 1,2-hexylenebis(isopentylideneimine), p,p'-biphenylenebis (Isopentylideneimine), 1,2-ethylenebis(isopropylideneimine), 1,3-propylenebis(isopropylideneimine), p-phenylenebis(isopentylideneimine), N-(1,3-dimethyl butylidene)-3-(triethoxysilyl)-1-propanamine and the like. The ketimine compound (D) may be used alone or in combination of two or more.

Ketimine compounds react rapidly with epoxy resins and can produce cured products with excellent compressive strength. 6,9-triaza-2,9-undecadiene, 2,10-diphenyl-3,6,9-triaza-2,9-undecadiene, 3,11-dimethyl-4,7,10-triaza-3,10- tridecadiene, 3,11-diethyl-4,7,10-triaza-3,10-tridecadiene, 2,4,12,14-tetramethyl-5,8,11-triaza-4,11-pentadecadiene, 2 , 4,20,22-tetramethyl-5,12,19-triaza-4,19-trieicosadiene, 2,4,15,17-tetramethyl-5,8,11,14-tetraaza-4, 14-octadecadiene is preferred.

The ketimine compound does not have reactivity with the epoxy resin and exists stably in the absence of moisture. On the other hand, ketimine compounds react with moisture such as moisture in the air and moisture contained in building materials such as concrete and exterior wall finishing materials, and the ketimine bond (N=C) is decomposed to generate primary amines. . The primary amine reacts with the epoxy resin to cure the adhesive composition.

_In the adhesive composition, the molar ratio ₍ [EP]/[ NH ₂ ]) is preferably 0.8 or more, more preferably 0.9 or more. When the molar ratio ([EP]/[NH ₂ ]) is 0.8 or more, the cured product of the adhesive composition has improved compressive strength and impact resistance. The number of moles of epoxy groups [EP] refers to the total number of moles of epoxy groups contained in the adhesive composition. Therefore, for example, when the adhesive composition contains an epoxysilane coupling agent, which will be described later, the number of moles of epoxy groups contained in the epoxysilane coupling agent is also included.

_In the adhesive composition, the molar ratio ₍ [EP ]/[NH ₂ ]) is preferably 6 or less, more preferably 5 or less. When the molar ratio ([EP]/[NH ₂ ]) is 6 or less, the compressive strength of the cured product can be improved by preventing unreacted amine from remaining in the cured product of the adhesive composition.

The number of moles [EP] of the epoxy group of the epoxy resin is obtained by dividing the content of the compound having the epoxy group by the epoxy equivalent of the compound for each compound having the epoxy group. are calculated respectively. The total number of moles of each epoxy group in the compounds having epoxy groups is defined as "the number of moles of epoxy groups in the epoxy resin [EP]".

The number of moles [NH ₂ ] of amino groups (--NH ₂ ) produced by hydrolysis of the ketimine compound is the value obtained by dividing the amount of amine compound produced by hydrolysis of the ketimine compound by the amine equivalent. The amine equivalent of the amine compound is a value measured according to JIS K7237 "Total amine value test method for amine curing agents for epoxy resins".

The content of the ketimine compound in the adhesive composition is 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and more preferably 35 parts by mass or more with respect to 100 parts by mass of the epoxy resin. . When the content of the ketimine compound is 10 parts by mass or more, the cured product of the adhesive composition has excellent compressive strength and impact resistance.

The content of the ketimine compound in the adhesive composition is 50 parts by mass or less relative to 100 parts by mass of the epoxy resin, preferably 48 parts by mass or less, more preferably 46 parts by mass or less, and more preferably 44 parts by mass or less. . When the content of the ketimine compound is 50 parts by mass or less, the compressive strength and impact resistance of the adhesive composition are improved.

[Additive]
The adhesive composition may contain additives within a range that does not impair its physical properties. Additives include, for example, hydrolysis-promoting catalysts, adhesion imparting agents, dehydrating agents, physical property modifiers that improve tensile physical properties, plasticizers, anti-sagging agents, reinforcing agents, coloring agents, flame retardants, anti-aging agents, oxidation Examples include inhibitors, ultraviolet absorbers, fragrances, and the like.

The adhesive composition preferably contains an epoxysilane coupling agent. An epoxysilane coupling agent means a compound containing a silicon atom to which an alkoxy group is bonded in one molecule and a functional group having an epoxy group. When the adhesive composition contains an epoxysilane coupling agent, it is possible to improve the adhesion to the concrete structure by the anchoring effect on defective parts such as junkers formed on the concrete structure, and The reaction between the epoxy group of the silane coupling agent and the hydroxyl group on the surface of the concrete structure can improve the adhesion between the cured adhesive composition and the concrete structure.

The epoxysilane coupling agent is not particularly limited, and examples thereof include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxy Propylethyldiethoxysilane, 2-(3,4 epoxycyclohexyl)ethyltrimethoxysilane and the like can be mentioned, and 3-glycidoxypropyltrimethoxysilane is preferred. The epoxysilane coupling agents may be used alone or in combination of two or more.

The content of the epoxysilane coupling agent in the adhesive composition is preferably 1 part by mass or more, more preferably 2 parts by mass or more, relative to 100 parts by mass of the epoxy resin. The content of the epoxysilane coupling agent in the adhesive composition is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, relative to 100 parts by mass of the epoxy resin. When the content of the epoxysilane coupling agent is 1 part by mass or more, the adhesiveness to the concrete structure can be improved by the effect of anchoring defective portions such as junkers formed on the concrete structure. The reaction between the epoxy group of the silane coupling agent and the hydroxyl group on the surface of the concrete structure can improve the adhesion between the cured adhesive composition and the concrete structure. When the content of the epoxysilane coupling agent is 10 parts by mass or less, the crosslink density of the cured product of the adhesive composition is moderate, and the compression strength and impact resistance of the cured product of the adhesive composition are improved. be able to.

[Adhesive composition]
The adhesive composition can be produced by uniformly mixing the epoxy resin, phenyl-type monoglycidyl ether, fatty acid-treated calcium carbonate, and ketimine compound, if necessary, and adding additives in a general-purpose manner.

The viscosity of the adhesive composition at 25° C. and 10 rpm according to JIS K6833 is preferably 5 Pa·s or more, more preferably 10 Pa·s or more, and more preferably 30 Pa·s or more. The viscosity of the adhesive composition at 25° C. and 10 rpm according to JIS K6833 is preferably 200 Pa·s or less, more preferably 190 Pa·s or less. When the viscosity of the adhesive composition is 5 Pa·s or more, the adhesive composition can be accurately applied to the desired location without flowing around. When the viscosity of the adhesive composition is 200 Pa·s or less, defective portions such as junkers formed in concrete structures can be filled with the adhesive composition without gaps, which is preferable.

The viscosity of the adhesive composition was measured using a BS type viscometer and rotor No. 1 according to JIS K6833. 5, measured at 25° C. and 50% relative humidity at a rotation speed of 10 rpm.

The Ti index of the adhesive composition is preferably 3.0 or higher, more preferably 4.0 or higher, and even more preferably 4.5 or higher. The Ti index of the curable composition is preferably 7.0 or less, more preferably 6.5 or less, and even more preferably 6.0 or less. When the Ti index of the adhesive composition is 3.0 or more, defective portions such as junkers formed in concrete structures can be filled with the adhesive composition without gaps, which is preferable. When the Ti index of the adhesive composition is 7.0 or less, the coating properties of the adhesive composition are improved.

Note that the Ti index of the adhesive composition was measured using B-type viscometer rotor no. 7, the viscosity ratio between the viscosity of the adhesive composition at 1 rpm and the viscosity of the adhesive composition at 10 rpm [(viscosity at 1 rpm)/(viscosity at 10 rpm)].

The ketimine compound reacts with moisture such as moisture in the air and moisture contained in building materials such as concrete and exterior wall finishing materials, and the ketimine bond (N=C) is decomposed to form a first-class adhesive composition. An amine is produced, and this primary amine reacts with the epoxy resin to cure the adhesive composition to produce a cured product having excellent compressive strength and impact resistance.

Since the adhesive composition is a one-liquid type epoxy adhesive composition, it is not necessary to mix the epoxy resin and the curing agent. The physical properties of the cured product do not change due to changes in the mixing ratio of the resin and the curing agent. Therefore, the cured product of the adhesive composition exhibits desired compressive strength and impact resistance.

As described above, the adhesive composition forms a cured product having excellent compressive strength and impact resistance when cured, and can be used to repair junkers formed on the surface of concrete structures such as tunnel walls and building structures. can be suitably used for

Specifically, the adhesive composition is injected into the junker formed on the surface of the concrete structure, and the adhesive composition is cured by air and/or moisture contained in the concrete structure to obtain a cured product. to generate By filling the inside of the junker with the cured product, the concrete structure in which the junker is formed can be repaired.

The tunnel walls are constantly under compressive stress due to pressure from the ground above the tunnel. Furthermore, vibrations caused by automobiles running in the tunnel impart shocks to the tunnel walls.

Since the adhesive composition produces a cured product having excellent compressive strength and impact resistance when cured, even if the cured product is subjected to the above-described compressive stress or impact force, the cured product remains , It can smoothly absorb compressive stress and impact force, does not cause damage such as cracks in the cured product, and can maintain excellent compressive stress and impact resistance for a long time.

The adhesive composition of the present invention can be cured by moisture contained in air or the like to produce a cured product having excellent compressive strength and impact resistance.

EXAMPLES The aspects of the present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

[Epoxy resin]
・ Bisphenol A type epoxy resin (manufactured by Yuka Shell, trade name “Epicoat 828”, epoxy equivalent: 189)
・ Bisphenol F type epoxy resin (trade name “jER806” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 165)

[Phenyl monoglycidyl ether]
・ Phenyl-type monoglycidyl ether 1 (2-phenylphenol glycidyl ether, trade name “SY-OPG” manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.)
・ Phenyl-type monoglycidyl ether 2 (2,3-epoxypropyl phenyl ether, manufactured by Kanto Chemical Co., Ltd., trade name “17031”)

[Fatty acid-treated calcium carbonate]
・ Fatty acid-treated calcium carbonate 1 (manufactured by Maruo Calcium Co., Ltd., trade name “Kalfain 200M”, BET specific surface area: 25 m ² /g, fatty acid: octadecanoic acid)
・ Fatty acid-treated calcium carbonate 2 (trade name “CCR” manufactured by Shiraishi Calcium Co., Ltd., BET specific surface area: 18 m ² /g, fatty acid: octadecanoic acid)
・Fatty acid-treated calcium carbonate 3 (trade name “NCC#2310” manufactured by Nitto Funka Kogyo Co., Ltd., BET specific surface area: 2.3 m ² /g, fatty acid: tetradecanoic acid)
・ Untreated calcium carbonate 4 (no surface treatment with fatty acid (untreated calcium carbonate), trade name “P30” manufactured by Toyo Fine Chemicals, BET specific surface area: 18 m ² /g)

[Ketimine compound]
- Ketimine compound 1 (amine value: 280 mgKOH/g, trade name "Epicure H30" manufactured by Mitsubishi Chemical Corporation)
・ Ketimine compound 2 (amine value: 290 mgKOH / g, trade name “ADEKA Hardener EH-235R-2” manufactured by ADEKA)

[Epoxysilane coupling agent]
・ Epoxysilane coupling agent (3-glycidoxypropyltrimethoxysilane, trade name “KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.)

(Examples 1 to 11, Comparative Examples 1 to 9)
Predetermined amounts of epoxy resin, phenyl-type monoglycidyl ether, fatty acid-treated calcium carbonate, untreated calcium carbonate, ketimine compound and epoxysilane coupling agent shown in Table 1 were mixed at 40° C. in a vacuum atmosphere using a planetary mixer. They were uniformly mixed to obtain a one-liquid type adhesive composition.

_In the adhesive composition, the molar ratio ₍ [EP ]/[NH ₂ ]) is described in the column of “epoxy group/amino group” in Table 1.

For the adhesive composition, the viscosity and Ti index at 25°C at 10 rpm in accordance with JIS K6833 were measured in the manner described above, and the results are shown in the columns of "10 rpm viscosity" and "Ti index" in Table 1, respectively. rice field.

Compressive strength and impact resistance of the obtained adhesive composition were measured in the following manner, and the results are shown in Table 1.

(compressive strength)
The adhesive composition was aged in an atmosphere of 23° C. and a relative humidity of 50% for 7 days to prepare a rectangular parallelepiped test piece of 25 mm long×13 mm wide×13 mm high. The compressive strength of the obtained test piece was measured according to JIS K6911, General Test Method for Thermosetting Plastics.

(shock resistance)
A test piece was prepared in the same manner as the compressive strength measurement method. The impact strength of the obtained test piece was measured according to JIS K7111 plastic-Charpy impact strength.

(Volume shrinkage rate)
The volume shrinkage rate of the adhesive composition was measured before and after curing by measuring the specific gravity according to JIS K6833. The smaller the volume shrinkage of the adhesive composition, the more effectively the cured product of the adhesive composition can maintain adhesion to the adherend without cracking.

Claims (3)

100 parts by mass of epoxy resin;
1 to 20 parts by mass of phenyl-type monoglycidyl ether,
10 to 200 parts by mass of fatty acid-treated calcium carbonate;
An adhesive composition comprising 10 to 50 parts by mass of a ketimine compound. 2. The adhesive composition according to claim 1, wherein the epoxysilane coupling agent is contained in an amount of 1 to 10 parts by mass based on 100 parts by mass of the epoxy resin. 3. The adhesive composition according to claim 1, wherein the adhesive composition has a viscosity of 5 to 200 Pa·s at 25° C. and 10 rpm according to JIS K6833.