JP7707677B2 - Active energy ray curable resin composition and concrete protection material - Google Patents

Description

The present invention relates to an active energy ray-curable resin composition and a concrete protection material.

Protective materials for outdoor concrete structures are required to have workability that allows construction to be completed in a short time, rapid curing properties, etc. As such materials, active energy ray-curable concrete protective materials containing a (meth)acrylate resin, a (meth)acrylic monomer, a photopolymerization initiator, and wax in a specific mass ratio have been proposed (see, for example, Patent Document 1).

Meanwhile, with the growing need for long-term durability, concrete protection materials are in demand, with the ability to self-repair any scratches that occur in the coating.

JP 2020-153109 A

The problem that the present invention aims to solve is to provide an active energy ray-curable resin composition that can produce a coating film that is excellent in workability and curability, and has excellent self-repairing properties.

As a result of intensive research conducted by the inventors to solve the above problems, they discovered that an active energy ray-curable resin composition containing a specific epoxy (meth)acrylate (A), a photopolymerization initiator (B), and an ester exchange catalyst (C) in a specific ratio can provide a coating film that is excellent in workability and curability, and has excellent self-repairing properties, and thus completed the present invention.

That is, the present invention provides an active energy ray curable resin composition containing an epoxy (meth)acrylate (A), a photopolymerization initiator (B), and an ester exchange catalyst (C), characterized in that the hydroxyl group concentration of the epoxy (meth)acrylate (A) is 2 mmol/g or more, and the content of the ester exchange catalyst (C) is 0.5 mol % or more relative to the hydroxyl groups of the epoxy (meth)acrylate (A).

The active energy ray-curable resin composition of the present invention has excellent workability and curability, and can produce a coating film with excellent self-repairing properties, making it suitable for use in the application of various civil engineering and construction materials, such as concrete protection materials.

The active energy ray curable resin composition of the present invention is an active energy ray curable resin composition containing an epoxy (meth)acrylate (A), a photopolymerization initiator (B), and an ester exchange catalyst (C), in which the hydroxyl group concentration of the epoxy (meth)acrylate (A) is 2 mmol/g or more, and the content of the ester exchange catalyst (C) is 0.5 mol% or more relative to the hydroxyl groups of the epoxy (meth)acrylate (A).

In the present invention, "(meth)acrylate" refers to either or both of methacrylate and acrylate, "(meth)acrylic monomer" refers to either or both of acrylic monomer and methacrylic monomer, and "(meth)acryloyl" refers to either or both of acryloyl and methacryloyl.

The epoxy (meth)acrylate may be, for example, one obtained by reacting an epoxy resin with an unsaturated monobasic acid by a conventionally known method.

Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol fluorene type epoxy resins, and biscresol fluorene type epoxy resins, novolac type epoxy resins such as phenol novolac type epoxy resins and cresol novolac type epoxy resins, oxodilone modified epoxy resins, and brominated epoxy resins of these resins. Polyhydric alcohols such as glycidyl ethers of phenols, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl ethers of alkylene oxide adducts of bisphenol A, and diglycidyl ethers of hydrogenated bisphenol A. glycidyl ether of 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, alicyclic epoxy resins such as 1-epoxyethyl-3,4-epoxycyclohexane, glycidyl esters such as phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, diglycidyl-p-oxybenzoic acid, dimer acid glycidyl ester, glycidyl amines such as tetraglycidyldiaminodiphenylmethane, tetraglycidyl-m-xylenediamine, triglycidyl-p-aminophenol, N,N-diglycidylaniline, heterocyclic epoxy resins such as 1,3-diglycidyl-5,5-dimethylhydantoin, triglycidyl isocyanurate, etc. Among these, bifunctional or trifunctional epoxy resins are preferred because they have improved self-repairing properties. These epoxy resins can be used alone or in combination of two or more.

As the unsaturated monobasic acid, for example, (meth)acrylic acid, cinnamic acid, crotonic acid, monomethyl maleate, monopropyl maleate, monobutene maleate, sorbic acid, mono(2-ethylhexyl) maleate, etc. can be used. These unsaturated monobasic acids can be used alone or in combination of two or more kinds.

The epoxy (meth)acrylate (A) has a (meth)acryloyl group that undergoes radical polymerization when irradiated with light or heated. The (meth)acryloyl group equivalent of the (meth)acrylate (A) is preferably 200 to 8,000 g/eq, and more preferably 250 to 5,000 g/eq, since this can further improve the balance between low viscosity, curability, and self-repairability. Here, the (meth)acryloyl group equivalent is a value calculated from the raw material composition.

The weight average molecular weight of the epoxy (meth)acrylate (A) is preferably 400 to 15,000, since this can improve the balance between low viscosity, curing properties, and self-repairing properties.

The average molecular weight in this invention is a value measured by gel permeation chromatography (GPC).

The average number of functional groups of the epoxy (meth)acrylate (A) is preferably 1.5 to 3.5, and more preferably 1.8 to 2.5, since this can further improve the balance between low viscosity, curability, and self-repairability.

Examples of the photopolymerization initiator (B) include acetophenone compounds such as 4-phenoxydichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, and 2,2-dimethoxy-2-phenylacetophenone; benzoin compounds such as benzoin, benzoin methyl ether, benzoin isoethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzophenone, benzoylbenzoic acid, benzoylbenzoic acid methyl, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3'-dimethyl- Benzophenone compounds such as 4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and other thioxanthone compounds; 4,4'-dimethylaminothioxanthone (also known as mineral's ketone), 4,4'-diethylaminobenzophenone, α-acyloxime Examples of the photopolymerization initiator (B) that can be used include anthraquinone compounds such as ester, benzyl, methylbenzoyl formate ("Biacure 55"), and 2-ethylanthraquinone; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 3,3',4,4'-tetra(tert-butyloperoxycarbonyl)benzophenone, and acrylated benzophenone. These photopolymerization initiators (B) can be used alone or in combination of two or more.

As the photopolymerization initiator (B), it is preferable to use 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, or bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, since these further improve the curing properties.

The amount of the photopolymerization initiator (B) used is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, per 100 parts by mass of the epoxy (meth)acrylate (A), since a coating film with excellent curing properties can be obtained.

Examples of the transesterification catalyst (C) include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkoxides of various metals such as sodium methoxide, sodium phenoxide, potassium ethoxide, tetraethyl titanate, tetraisopropyl titanate, and tetra-n-butyl titanate; complexes of various metals such as zinc acetylacetonate and zirconium acetylacetonate; organic tin compounds such as dibutyltin dimethoxide, dibutyltin oxide, dibutyltin diacetate, dibutyltin dioctate, and dibutyltin dilaurate; N,N'-dimethylaminopyridine (DMAP), 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 1, Strongly basic amine compounds such as 5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,4-diazabicyclo[2.2.2]octane (DABCO); various quaternary ammonium salts such as tetramethylammonium salt, tetrabutylammonium salt, trimethyl(2-hydroxypropyl)ammonium salt, cyclohexyltrimethylammonium salt, tetrakis(hydroxymethyl)ammonium salt, dilauryldimethylammonium salt, and tributylmethylammonium salt, which have as counter anions various carboxylates such as acetate and propionate, or anions such as chloride, bromide, and hydroxide, so-called quaternary ammonium salts; Examples of suitable phosphonium salts include methylphosphonium salts, tetraethylphosphonium salts, and tetrapropylphosphonium salts; tetrabutylphosphonium salts, and trimethyl(2-hydroxypropyl)phosphonium salts, each of which has a counter anion such as acetate, propionate, or other carboxylate, or chloride, bromide, or hydroxide; acidic compounds such as methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, octanesulfonic acid, trifluoroacetic acid, phosphoric acid, sulfuric acid, and hydrochloric acid; and salts of the above-mentioned acidic compounds with nitrogen-containing basic compounds such as ammonia, triethylamine, diethanolamine, and triethanolamine. Among these, organometallic compounds such as alkoxides of various metals, complexes of various metals, and organotin compounds are preferred because they further improve the self-repairing property. These esterification catalysts (C) may be used alone or in combination of two or more.

The content of the transesterification catalyst (C) is 0.5 mol% or more relative to the hydroxyl groups of the epoxy (meth)acrylate (A), but since this further improves the self-repairing property, 2 to 15 mol% is preferable, and 5 to 10 mol% is more preferable.

The active energy ray-curable resin composition of the present invention contains the epoxy (meth)acrylate (A), the photopolymerization initiator (B), and the transesterification catalyst (C), and may contain other additives, etc., as necessary.

Examples of the other additives include (meth)acrylic monomers, polymerization inhibitors, antioxidants, light stabilizers, solvents, rust inhibitors, thixotropic agents, sensitizers, leveling agents, tackifiers, antistatic agents, flame retardant curing agents, curing accelerators, pigments, fillers, reinforcing materials, aggregates, etc.

Examples of the (meth)acrylic monomer include (meth)acrylic monomers having an alicyclic structure such as isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate; methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, sec-butyl (meth)acrylate, isobutyl (meth)acrylate, and 2-ethylbutyl (meth)acrylate. aliphatic (meth)acrylic monomers such as 3-methoxybutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, n-octyl (meth)acrylate, nonyl (meth)acrylate, dodecyl (meth)acrylate, 3-methylbutyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, neopentyl (meth)acrylate, hexadecyl (meth)acrylate, and isoamyl (meth)acrylate; (meth)acrylic monomers having an ether group such as 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, methoxypolyethylene glycol acrylates having an added mole number of oxyethylene in the range of 1 to 15, ethoxy-diethylene glycol (meth)acrylate, and ethyl carbitol (meth)acrylate; (meth)acrylic monomers having a hydroxyl group such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; benzyl (meth)acrylate. , aromatic (meth)acrylic monomers such as benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxy polyethylene glycol acrylate, phenyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate; and (meth)acrylic monomers having nitrogen atoms such as (meth)acrylamide, dimethyl (meth)acrylamide, acryloylmorpholine, dimethylaminopropyl (meth)acrylamide, isopropyl (meth)acrylamide, diethyl (meth)acrylamide, diacetone (meth)acrylamide, and hydroxyethyl acrylamide. These (meth)acrylic monomers may be used alone or in combination of two or more.

The active energy rays that cure the active energy ray-curable resin composition of the present invention are ionizing radiation such as ultraviolet rays, electron beams, alpha rays, beta rays, and gamma rays, and specific energy sources or curing devices include, for example, germicidal lamps, ultraviolet fluorescent lamps, carbon arcs, xenon lamps, high-pressure mercury lamps for copying, medium- or high-pressure mercury lamps, extra-high-pressure mercury lamps, electrodeless lamps, metal halide lamps, fluorescent chemical lamps, ultraviolet rays using natural light as a light source, or electron beams from scanning or curtain-type electron beam accelerators.

The active energy ray-curable resin composition of the present invention can be used as a protective material for concrete, such as cement concrete, asphalt concrete, mortar concrete, resin concrete, water-permeable concrete, and ALC (Autoclaved Lightweight Aerated Concrete) boards.

The concrete protection material of the present invention is easy to work with, hardens, and provides a coating film with excellent self-repair properties, making it suitable for use in the application of various civil engineering and construction materials, such as concrete repair materials and waterproofing materials.

The present invention will be described in more detail below with reference to specific examples. The average molecular weight was measured under the following GPC measurement conditions.

[GPC measurement conditions]
Measurement device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were used, connected in series.
"TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mm I.D. x 30cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: tetrahydrofuran (THF)
Flow rate: 1.0 mL/min Injection volume: 100 μL (sample concentration 4 mg/mL in tetrahydrofuran solution)
Standard sample: A calibration curve was prepared using the following monodisperse polystyrene.

(Monodisperse polystyrene)
"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

(Synthesis Example 1: Synthesis of epoxy (meth)acrylate (A-1))
A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 1,850 parts by mass of a bisphenol-type epoxy compound ("Epicron 850" manufactured by DIC Corporation), 860 parts by mass of acrylic acid, 1.36 parts by mass of hydroquinone, and 10.8 parts by mass of triethylamine, and the mixture was heated to 120°C and reacted for 10 hours to obtain an epoxy (meth)acrylate resin (A-1) having an acid value of 3.5, a number average molecular weight of 513, and a hydroxyl group concentration of 3.9 mmol/g.

(Synthesis Example 2: Synthesis of epoxy (meth)acrylate (A-2))
Into a four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser, 1,850 parts by mass of propylene glycol diglycidyl ether, 860 parts by mass of acrylic acid, 1.36 parts by mass of hydroquinone, and 10.8 parts by mass of triethylamine were charged, and the temperature was raised to 120° C., and the mixture was reacted for 10 hours at the same time, to obtain an epoxy (meth)acrylate (A-2) having an acid value of 0.5, a number average molecular weight of 332, and a hydroxyl group concentration of 6.0 mmol/g.

(Example 1: Preparation and evaluation of active energy ray-curable resin composition (1))
Into a light-shielding container equipped with a stirrer, a reflux condenser, and a thermometer, 100 parts by mass of the epoxy (meth)acrylate (A-1) obtained in Synthesis Example 1, 1.5 parts by mass of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (hereinafter abbreviated as "photopolymerization initiator (B-1)"), and 25 parts by mass of dibutyltin laurate (hereinafter abbreviated as "transesterification catalyst (C-1)") were blended and stirred at 80°C until the mixture became uniform, thereby obtaining an active energy ray-curable resin composition (1).

[Evaluation of workability (viscosity)]
The active energy ray-curable resin composition (1) obtained above was measured at 25° C. using a Brookfield type viscometer (TV-22, manufactured by Toki Sangyo Co., Ltd.) and evaluated according to the following criteria.
○: Less than 5,000 mPa·s ×: 5,000 mPa·s or more

[Preparation of cured coating film]
The resin was poured into a 0.5 mm thick mold made of a 50 μm thick polyethylene terephthalate film (release PET50). After that, the resin was irradiated with 1000 mJ/cm2 ultraviolet light using an ultraviolet irradiator (fluorescent chemical lamp) to produce a cured coating film.

[Evaluation of Curability]
The surface of the coating film obtained above was checked for the presence or absence of tackiness by touching with a finger.
○: No tack
×: Tucked

[Evaluation of self-repairing ability]
The coating film obtained above was scratched with a cutter knife to a length of 3.0 cm and a depth of 0.2 mm. The coating film was left in a 160°C environment, and the time until the scratch disappeared was measured, and the self-repairing property was evaluated according to the following criteria. The scratch was checked every 10 minutes, and was stopped after 150 minutes.
◯: Scar disappeared within 150 minutes ×: Scar remained after 150 minutes

(Example 2: Preparation and evaluation of active energy ray-curable resin composition (2))
An active energy ray-curable resin composition (2) was prepared in the same manner as in Example 1, except that the epoxy (meth)acrylate (A-1) used in Example 1 was changed to the epoxy (meth)acrylate (A-2). Then, each physical property was evaluated.

(Example 3: Preparation and evaluation of active energy ray-curable resin composition (4))
An active energy ray-curable resin composition (3) was prepared in the same manner as in Example 1, except that the transesterification catalyst (C-1) used in Example 1 was changed to zinc acetylacetonate (hereinafter, abbreviated as "transesterification catalyst (C-2)"). Then, each physical property was evaluated.

(Example 4: Preparation and evaluation of active energy ray-curable resin composition (4))
An active energy ray-curable resin composition (4) was prepared in the same manner as in Example 1, except that the transesterification catalyst (C-1) used in Example 1 was changed to tetraethyl titanate (hereinafter, abbreviated as "transesterification catalyst (C-3)"). Then, each physical property was evaluated.

(Example 5: Preparation and evaluation of active energy ray-curable resin composition (5))
An active energy ray-curable resin composition (5) was prepared in the same manner as in Example 1, except that the 10 parts by mass of the transesterification catalyst (C-1) used in Example 1 was changed to 1 part by mass, and then each physical property was evaluated.

(Example 6: Preparation and evaluation of active energy ray-curable resin composition (6))
An active energy ray-curable resin composition (6) was prepared in the same manner as in Example 1, except that the 10 parts by mass of the transesterification catalyst (C-1) used in Example 1 was changed to 20 parts by mass, and then each physical property was evaluated.

(Example 7: Preparation and evaluation of active energy ray-curable resin composition (7))
An active energy ray-curable resin composition (7) was prepared in the same manner as in Example 1, except that 100 parts by mass of the epoxy (meth)acrylate (A-1) used in Example 1 was changed to 75 parts by mass of the epoxy (meth)acrylate (A-1) and 25 parts by mass of acryloylmorpholine (hereinafter, abbreviated as "ACMO"). Then, each physical property was evaluated.

(Comparative Example 1: Preparation and Evaluation of Active Energy Ray-Curable Resin Composition (R1))
An active energy ray-curable resin composition (R1) was prepared in the same manner as in Example 1, except that the 10 parts by mass of the transesterification catalyst (C-1) used in Example 1 was changed to 0.005 parts by mass, and then each physical property was evaluated.

(Comparative Example 2: Preparation and Evaluation of Active Energy Ray-Hardening Concrete Protection Material (R2))
An active energy ray-curable resin composition (R2) was prepared in the same manner as in Example 1, except that the epoxy (meth)acrylate (A-1) used in Example 1 was changed to EO-modified bisphenol A dimethacrylate ("FA-321M" manufactured by Showa Denko Materials Co., Ltd.), and then each physical property was evaluated.

The composition and evaluation results of the active energy ray-curable resin composition obtained above are shown in Tables 1 and 2.

It was confirmed that the active energy ray-curable resin compositions of the present invention in Examples 1 to 7 have low viscosity and excellent workability, and can produce coating films with excellent curing and self-repairing properties.

Comparative Example 1 is an example in which the content of the transesterification catalyst (C) is less than the lower limit, but it was confirmed that the self-repairing properties of the coating film were insufficient.

Comparative Example 2 is an example in which EO-modified bisphenol A dimethacrylate was used instead of epoxy (meth)acrylate (A), but it was confirmed that the self-repairing properties of the coating film were insufficient.

Claims (2)

A concrete protection material comprising an active energy ray-curable resin composition containing an epoxy (meth)acrylate (A), a photopolymerization initiator (B), and an ester exchange catalyst (C), wherein the epoxy (meth)acrylate (A) has a hydroxyl group concentration of 2 mmol/g or more, and the content of the ester exchange catalyst (C) is 0.5 mol % or more relative to the hydroxyl groups of the epoxy (meth)acrylate (A). 2. The concrete protective material according to claim 1, wherein the transesterification catalyst (C) is an organometallic compound.