TWI586729B - Curable resin composition - Google Patents

Description

Curable resin composition

The present invention relates to a curable resin composition which is excellent in adhesion to a substrate even in a cold region and which has flexibility in the obtained cured film.

Conventionally, in order to improve the adhesion of a coating material containing an epoxy resin as a main component to an inorganic substrate, there is a technique of adding a decane coupling agent (for example, Patent Document 1). However, the decane coupling agent mostly has a low boiling point and needs to be added in a large amount to the thermosetting resin. Further, the effect of improving the adhesion can not be said to be sufficient, and it is also possible to obtain the attachability required at a practical level by simultaneously adding an adhesion aid such as a salt such as titanium or zirconium, a phosphate ester or a urethane resin. many. At this time, the addition of these adhesion aids not only increases the number of processes, but also requires strict optimization of the type of the attachment auxiliary agent or the amount thereof to be added without impairing the characteristics of the coating.

Therefore, Patent Document 2 proposes a curable resin composition in which a polyfunctional thiol compound and a specific thioether-containing alkoxydecane derivative are mixed with an epoxy resin composition and an amine compound. The curable resin composition can exhibit excellent adhesion to an inorganic substrate as in the case of using a decane coupling agent without adding another adhesion aid.

Prior art literature

[Patent Document]

Patent Document 1: Japanese Patent Publication No. 7-300491

Patent Document 2: JP-A-2012-246464

However, as disclosed in Patent Document 2, a curable resin composition in which a polyfunctional thiol compound and a specific thioether-containing alkoxydecane derivative are mixed with an epoxy resin composition and an amine compound is known, although an inorganic substrate is used. The adhesiveness is excellent and the storage stability of the resin composition is excellent, but there is a technical problem that in a cold region, the cured film is likely to be cracked when bent due to lack of flexibility, and lacks adhesion.

The present invention has been made in view of the above circumstances, and it is an object of the invention to provide a material which is excellent in adhesion to a substrate even in a cold region and which has flexibility in the obtained cured film.

The curable resin composition of the present invention contains (A) a thioether-containing (meth) acrylate derivative represented by the following formula 1, and (B) a polyfunctional epoxy resin having a weight average molecular weight of 200 to 50,000 and (C) an amine compound having a weight average molecular weight of 90 to 700, and a mass ratio ((A)/(B)) of the component (A) to the component (B) is 0.05 to 30, relative to the component (A) and (B) The total mass of the component is 100 parts by mass, and 0.01 to 50 parts by mass of the component (C) is added.

Wherein a is an integer from 1 to 3, b is 0 or 1, c is an integer from 1 to 3, a sum of b and c is 4; and R ¹ is a methylene group, an ethylene group or an isopropylidene group. ; R ² is a divalent functional group represented by the following formula 2 or the following formula 3; and R ³ is a methyl group or an ethyl group. R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms.

R ⁵ is a hydrogen atom or a methyl group,

R ⁵ is a hydrogen atom or a methyl group.

The curable resin composition of the present invention may further contain 2 to 300 parts by mass of (D) a polyfunctional weight average molecular weight of 200 to 50,000 with respect to 100 parts by mass of the total mass of the component (A) and the component (B). Base) acrylate.

The curable resin composition of the present invention may further contain 0.01 to 10 parts by mass of (E) a photopolymerization initiator, based on 100 parts by mass of the total mass of the component (A) and the component (D).

Further, in the present invention, "(meth) acrylate" means a general term including both acrylate and methacrylate. The terms "(meth)acrylic acid" and "(meth)acryloxy" are also used collectively. Further, in the present invention, "○○~××" indicating a numerical range is a concept including an upper limit value ("○○") and a lower limit value ("××"). In other words, it means "○○ or more × × or less". Further, in the present invention, the "molecular weight" means a weight average molecular weight unless otherwise specified.

According to the curable resin composition of the present invention, (B) a specific molecular weight (B) is added in a balanced manner to the (I) specific thioether-containing (meth) acrylate derivative as an active ingredient for improving adhesion. a multifunctional epoxy resin and (C) an amine compound of a specific molecular weight. Therefore, it is not necessary to add another adhesion aid or the like as in the conventional decane coupling agent, and it also has excellent adhesion to an inorganic substrate. In particular, the curable resin composition using a polyfunctional thiol compound in the past is also excellent in cold conditions in which the adhesion to the substrate is insufficient, and the obtained cured film has flexibility.

The invention is described in detail below. The curable resin composition of the present invention contains the following components (A), (B), and (C) as essential components, and further optionally contains the component (D) and the component (E).

<Sulfur ether-containing (meth) acrylate derivative ((A) component)>

The (A) thioether-containing (meth) acrylate derivative of the present invention is a compound represented by the following formula 1.

Wherein a is an integer from 1 to 3, b is 0 or 1, c is an integer from 1 to 3, a sum of b and c is 4; and R ¹ is a methylene group, an ethylene group or an isopropylidene group. ; R ² is a divalent functional group represented by the following formula 2 or the following formula 3; and R ³ is a methyl group or an ethyl group. R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms.

R ⁵ is a hydrogen atom or a methyl group,

R ⁵ is a hydrogen atom or a methyl group.

The hydrocarbon group having 1 to 12 carbon atoms of R ⁴ in the above formula 1 may, for example, be a linear alkyl group, an alkyl group having a side chain or a cycloalkyl group. 1 in the above formula R ¹ is a methylene, ethylene, isopropylidene (isopropylene), ethylene, isopropylidene because of the large effect of improving the adhesion and excellent efficiency.

When a thioether-containing (meth) acrylate derivative represented by the above formula 1 is added to a paint or the like, even in a cold environment such as -10 ° C, the susceptibility aid can exhibit a high substrate strength. The effect of improving the adhesion is excellent, and the effect of imparting flexibility to the obtained coating film is excellent. Further, since the thioether-containing (meth) acrylate derivative represented by the above formula 1 has a small molecular weight, it is excellent in solubility to other components. Therefore, the thioether-containing (meth) acrylate derivative represented by the above formula 1 has high compatibility with many resins, and can be used for a wide range of coating materials, and has high versatility.

<Multifunctional epoxy resin ((B) component)>

The polyfunctional epoxy resin as the component (B) is an organic compound having two or more epoxy groups (oxirane rings). The polyfunctional epoxy resin has a weight average molecular weight of 200 to 50,000, preferably 200 to 48,000, more preferably 200 to 46,000. Even if the weight average molecular weight is less than 200, there is no problem concerning adhesion, but the volatility of the polyfunctional epoxy resin tends to increase, and the odor tends to be strong. on the other hand, When the weight average molecular weight is more than 50,000, the solubility in other components is lowered, and the adhesion to the substrate may be lowered.

The epoxy equivalent of the polyfunctional epoxy resin is from 80 to 6000 g/mol, preferably from 85 to 5500 g/mol, more preferably from 90 to 5000 g/mol. When the epoxy equivalent is less than 80 g/mol, since the epoxy group per unit volume is excessive, the epoxy group which is not reacted with the thiol group of the (A) thioether-containing (meth) acrylate derivative remains in a large amount, and thus There is a concern that the toughness of the cured film formed of the curable resin composition is lowered and the adhesion is lowered. On the other hand, when the epoxy equivalent is more than 6000 g/mol, since the epoxy group concentration is remarkably lowered, the reaction efficiency with the thiol group of the (A) thioether-containing (meth) acrylate derivative is lowered, and thus The cured film formed of the curable resin composition has a lowered toughness and a decrease in adhesion to a substrate.

Examples of the polyfunctional epoxy resin as the component (B) include a glycidyl ether type epoxy resin, a glycidyl ester type epoxy resin, a glycidylamine type epoxy resin, or a peroxide-containing double bond compound. An oxidized epoxy resin obtained by double-bonding. Among them, the glycidyl ether type epoxy resin and the glycidyl ester type epoxy resin are preferred because of low reactivity at room temperature and high storage stability. In addition, the polyfunctional epoxy resin may be used alone or in combination of two or more.

<Glycidyl ether type epoxy resin>

The glycidyl ether type epoxy resin is preferably a reaction product of epichlorohydrin and a compound represented by the following formula 4.

Wherein d is an integer of 2 to 30, R ⁶ is a hydrocarbon group having 2 to 200 carbon atoms (β1), and a group having 2 to 300 carbon atoms and only a group consisting of ether oxygen (-O-) and a hydrocarbon group (β2), isocyanurate ring (β3), or a group formed by an isocyanurate ring and a hydrocarbon group (β4).

In the compounds represented by the above formula 4, d is 2 to 20 and R ⁶ is a hydrocarbyl group having 2 to 150 carbon atoms (β1-1), or d is 2 to 20 and R ⁶ is 2 carbon atoms, The compound (β2-1) of a group of only ~150, which is formed of a hydrocarbon group and an ether oxygen (-O-), is preferred because of its high solubility with other components. Examples of (β1-1) include an alkylene glycol having 2 to 10 carbon atoms, glycerin, pentaerythritol, trimethylolpropane, and phenol novolac ( ), bisphenol A, etc. Examples of (β2-1) include polyethylene glycol, polypropylene glycol, and dipentaerythritol.

By reacting epichlorohydrin with the compound of the above formula 4, an epichlorohydrin can be subjected to an addition reaction with a hydroxyl group of the compound of the above formula 4 to obtain a chlorohydrin, which is a base such as sodium oxide. The resulting chlorohydrin is ring-closed to obtain an epoxy resin. Further, the glycidyl ether type epoxy resin may be an epoxy resin formed by subjecting a partial epoxy group of the epoxy resin obtained after the ring closure reaction to ring-opening polymerization.

The reaction product of epichlorohydrin and the compound of the above formula 4 has the structure of the following formula 5.

Wherein d is an integer of 2 to 30, R ⁶ is a hydrocarbon group having 2 to 200 carbon atoms (β1), and a group having 2 to 300 carbon atoms and only a group consisting of ether oxygen (-O-) and a hydrocarbon group (β2), an isocyanurate ring (β3), or a group formed by an isocyanurate ring and a hydrocarbon group (β4).

<Glycidyl Ester Type Epoxy Resin>

The glycidyl ester type epoxy resin is a weight average molecular weight obtained by copolymerizing a monomer having an epoxy group such as glycidyl (meth)acrylate alone or with an alkyl (meth) acrylate having 4 to 25 carbon atoms. A polymer of 3,000 to 20,000 or a reaction product of epichlorohydrin and a compound represented by the following formula 6.

In the formula, e is an integer of 2 to 8, and R ⁷ is a hydrocarbon group having 2 to 20 carbon atoms (β5), and a group having 2 to 30 carbon atoms and consisting only of ether oxygen (-O-) and a hydrocarbon group. (β6), an isocyanurate ring (β7), or a group formed by an isocyanurate ring and a hydrocarbon group (β8).

By reacting epichlorohydrin with the compound of the above formula 6, an epichlorohydrin can be subjected to an addition reaction with a carboxyl group of the compound of the above formula 6 to obtain a chlorohydrin, which is obtained by a base such as sodium hydroxide. The chlorohydrin is ring-closed to obtain a glycidyl ester type epoxy resin. Further, an epoxy resin obtained by subjecting a partial epoxy group of a glycidyl ester type epoxy resin to ring-opening polymerization may also be used.

In the compound of the above formula 6, the compound (β5-1) wherein e is 2 to 4 and R ⁷ is a hydrocarbon group having 2 to 10 carbon atoms, or e is 2 to 6 and R ⁷ is 2 carbon atoms. a compound (β6-1) of only a group formed by an ether oxygen (-O-) and a hydrocarbon group, or a compound in which e is 3 and R ⁷ is a group formed only of an isocyanurate and a hydrocarbon group ( Β8-1) is preferably listed for reasons of high solubility.

Examples of (β5-1) include hydrogenated hydrophthalic acid and trimellitic acid. Examples of (β6-1) include a reaction product of pentaerythritol and trimellitic anhydride. Examples of (β8-1) include 1,3,5-tris(2-carboxyethyl)isocyanurate.

The reaction product of epichlorohydrin and the compound of the above formula 6 has the structure of the following formula 7.

In the formula, e is an integer of 2 to 8, and R ⁷ is a hydrocarbon group having 2 to 20 carbon atoms (β5), and a group having 2 to 30 carbon atoms and consisting only of ether oxygen (-O-) and a hydrocarbon group. (β6), an isocyanurate ring (β7), or a group formed by an isocyanurate ring and a hydrocarbon group (β8).

<Amine compound ((C) component)>

The amine compound as the component (C) promotes (catalyzes) the reaction of a thiol group with an epoxy group. The amine compound as the component (C) may, for example, be a monofunctional amine having a weight average molecular weight of 90 to 700, preferably 100 to 690, more preferably 110 to 680, or a polyamine having a plurality of amino groups. When the weight average molecular weight of the amine compound is less than 90, the volatility of the amine compound is increased, which not only causes odor and voids, but also causes a decrease in the amine concentration at the time of heat curing, making the crosslinking reaction difficult. When it is carried out, the adhesion is liable to decrease. When the weight average molecular weight of the amine compound exceeds 700, the water resistance is lowered, and the adhesion is liable to lower.

As the monofunctional amine, a primary amine, a secondary amine or a tertiary amine can be mentioned. Examples of the polyamine include a primary amine, a secondary amine, a tertiary amine, and a complex amine. The complex amine means an amine having two or more kinds of a primary amino group, a secondary amino group, and a tertiary amino group. Examples of such a complex amine include an imidazoline compound, an imidazole compound, an N-substituted pyridazine compound, and an N,N-dimethylurea derivative. In addition, the amine compound may be used alone or in combination of two or more.

Further, in order to adjust the catalytic activity, the amine compound may also form a salt with an organic acid in advance. Examples of the organic acid to be reacted with the amine compound in advance include an aliphatic carboxylic acid such as stearic acid or 2-ethylhexanoic acid having 1 to 20 carbon atoms and having 1 to 5 carboxyl groups in the molecule, and the number of carbon atoms is An aromatic carboxylic acid such as pyromellitic acid, trimellitic acid or benzoic acid having 1 to 20 and having 1 to 10 carboxyl groups in the molecule, or isocyanuric acid. Further, in order to adjust the catalytic activity, the amine compound as the component (C) may be added after forming an adduct with the polyfunctional epoxy resin as the component (B).

<Imidazole compound>

Among the amine compounds, the imidazole compound is most suitable for both storage stability and short-time curing under low temperature conditions. Further, an imidazole compound coated with phenol or the like can also be used. This imidazole compound is a compound represented by the following formula 8.

R ⁹ is a cyano group, a hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms substituted by 2,3-diaminotriazine, an alkoxy group having 1 to 4 carbon atoms, or a hydrogen atom, R ⁸ , R ¹⁰ and R ¹¹ are a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a hydrogen atom, and R ⁸ to R ¹¹ are a carbon atom when bonded to form a ring. 2 to 8 hydrocarbon groups.

Specific examples of the imidazole compound include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1,2-dimethylimidazole, and 2-phenyl group. 4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-(2-cyanoethyl) -2-methylimidazole, 1-(2-cyanoethyl)-2-undecylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, 1- (2-cyanoethyl)-2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, 2,3-dihydro-1H-pyrrole [1, 2-a]benzimidazole, 2,4-diamino-6-[2-methylimidazolyl-(1)]ethyl-s-triazine, 2,4-diamino-6-[2-' Undecylimidazo-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')] Ethyl-s-triazine, 2-phenyl-4,5-dimethylolimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole.

<Polyfunctional (meth) acrylate ((D) component)>

The curable resin composition of the present invention containing (A) a sulfide-containing (meth) acrylate derivative, (B) a polyfunctional epoxy resin, and (C) an amine compound can be cured by heating. By further The (D) polyfunctional (meth) acrylate is added to the curable resin composition, and photocurability or photothermal double curability can be imparted.

Among the compounds containing a double bond, the advantage of using a polyfunctional (meth) acrylate as the component (D) is exemplified by the difficulty in the composition of the curable resin of the present invention at room temperature (A). a thioether-containing (meth) acrylate derivative, which can be used for a long period of time, that is, can have high storage stability; and is tough after reacting with (A) a thioether-containing (meth) acrylate derivative. The cured product; (A) the reaction of the thioether-containing (meth) acrylate derivative with the (D) polyfunctional (meth) acrylate is difficult to be catalyzed by the (C) amine compound; Epoxy resin reaction, etc.

A preferred example of such a polyfunctional (meth) acrylate is a compound represented by the following formula 9. In addition, the polyfunctional (meth) acrylate which is a component (D) may be used alone or in combination of two or more.

Wherein f is an integer of 2 to 30, R ¹² is a hydrocarbon group having 2 to 200 carbon atoms (ε1), and a group having 2 to 300 carbon atoms and only a group consisting of ether oxygen (-O-) and a hydrocarbon group (ε2), an isocyanurate ring (ε3), or a group formed by an isocyanurate ring and a hydrocarbon group (ε4), and R ¹³ is a hydrogen atom or a methyl group.

Further, as the (D) polyfunctional (meth) acrylate, a polymer type can also be suitably used. Examples of the polymer-type polyfunctional (meth) acrylate include a (meth) acrylate having a group reactive with an epoxy group such as (meth)acrylic acid, and (meth) a polymer obtained by reacting a homopolymer or a copolymer of an epoxy group-containing (meth) acrylate such as glycidyl acrylate; for example, 2-isocyanoethyl 2-methacrylate or the like (methyl) group reactive with a hydroxyl group a polymer obtained by reacting a acrylate or a homopolymer or a copolymer of a (meth) acrylate having a hydroxyl group such as hydroxyethyl (meth)acrylate; and having, for example, glycidyl (meth)acrylate A polymer obtained by reacting a (meth) acrylate of a group reactive with a carboxyl group with a homopolymer or a copolymer of a (meth) acrylate having a carboxyl group such as (meth)acrylic acid.

(D) The polyfunctional (meth) acrylate has a weight average molecular weight of from 200 to 50,000, preferably from 220 to 40,000, more preferably from 240 to 30,000. (D) When the weight average molecular weight of the polyfunctional (meth) acrylate is less than 200, there is no problem concerning adhesion, but the volatility tends to increase and the odor tends to be strong. On the other hand, when the weight average molecular weight is more than 50,000, there is a possibility that the solubility of other components is lowered.

Further, the (meth) acrylate equivalent of the (D) polyfunctional (meth) acrylate is from 80 to 6000 g/mol, preferably from 80 to 4,500 g/mol, more preferably from 85 to 3,000 g/mol. If the (meth) acrylate equivalent is less than 80 g/mol, the thiol group of the (meth) acrylate-containing (meth) acrylate derivative is not present due to excess (meth) propylene oxime per unit volume. Since the (meth) propylene oxime group of the reaction remains in a large amount, the toughness of the cured film formed of the curable resin composition may be lowered, and the adhesion may be lowered. On the other hand, if the (meth) acrylate equivalent is more than 6000 g/mol, the (meth) propylene oxime group is significantly lower in concentration, and (A) the thioether-containing (meth) acrylate derivative thiol Since the reaction efficiency of the base is lowered, the toughness of the cured film formed of the curable resin composition may be lowered, and the adhesion may be lowered.

<Photopolymerization initiator ((E) component)>

In order to promote the reaction of a thiol group with a (meth) propylene fluorenyloxy group, the (E) component photopolymerization initiator is added. As a photopolymerization initiator, it is a photoradical initiator, a photocation initiator, a photoanion initiator, and the like. The photoradical initiator is preferably used for shortening the reaction time, and the photocationic initiator is preferably used for reducing the curing shrinkage, and the photoanion initiator is preferably used in the field of circuits and the like. The condition of adhesion.

As the photoradical initiator, for example, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-one, 2-hydroxy- 2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one , 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propenyl)-benzyl]-phenyl}-2-methyl-propan-1-one, 2-methyl 1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide, 2 , 4,6-trimethylbenzimidyl-diphenyl-phosphine oxide, and the like.

Examples of the photocationic initiator include bis(4-t-butylphenyl)iodonium hexafluorophosphate, bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate, and cyclopropyldiene. Phenylhydrazine tetrafluoroborate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, 2-(3,4-dimethoxystyryl)-4,6-double (trichloromethyl)-1,3,5-triazine, triphenylsulfonium tetrafluoroborate, triphenylphosphonium bromide, tri-p-tolylphosphonium hexafluorophosphate, tri-p-tolyltrifluoromethane Sulfonate and the like.

As the photoanion initiator, for example, acetophenone-o-benzhydrazide, nifedipine, 2-(9-oxanthene-2-yl)propionic acid 1,5,7-three can be cited. Azabicyclo[4.4.0]non-5-ene, 2-nitrophenylmethyl 4-methylpropenyl acridine-1-carboxylate, 1,2-diisopropyl-3- [Bis(dimethylamino)methylene]indole 2-(3-benzhydrylphenyl)propionate, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidinium butyl Triphenyl borate and the like.

<composition ratio (equal ratio)>

The curable resin composition of the present invention has a mass ratio ((A)/(B)) of (A) a sulfide-containing (meth) acrylate derivative to (B) a polyfunctional epoxy resin of 0.05 to 30. Way to add. Here, "(A)/(B)" means a value obtained by dividing the mass of the (A) thioether-containing (meth) acrylate derivative by the mass of the (B) polyfunctional epoxy resin. The optimum (A) / (B) value depends on the characteristics required for the curable resin composition, (A) a sulfide-containing (meth) acrylate derivative or (B) a polyfunctional epoxy resin, and optionally added The structure of the (D) polyfunctional (meth) acrylate is different. The properties of the curable resin composition after curing are strictly limited by the unit weight of the curable resin composition The amount of (thiol group number) / (number of epoxy groups + (meth) propylene fluorenyloxy group) (hereinafter referred to as thiol / (epoxy + olefin) ratio) affects the amount. For example, if the thiol/(epoxy+ene) ratio is in the range of 0.5 to 1.5, it is easy to form a close crosslink and it is easy to form a tough cured product. On the other hand, when the thiol/(epoxy+ene) ratio is 0.1 or more and less than 0.5, or more than 1.5 and 2.0 or less, a soft viscous cured product can be obtained. When the thiol/(epoxy+ene) ratio is less than 0.1 or exceeds 2.0, gelation is difficult, and the adhesion tends to be lowered.

Further, in the curable resin composition of the present invention, the total mass ((A) + (B)) relative to (A) the thioether-containing (meth) acrylate derivative and (B) the polyfunctional epoxy resin. 100 parts by mass, 0.01 to 50 parts by mass of the (C) amine compound is added, preferably 0.01 to 45 parts by mass. When the amount of the component (C) is less than 0.01 parts by mass based on 100 parts by mass of the ((A) + (B)), the reaction of the thiol group and the epoxy group takes time, and curing failure occurs. When it exceeds 50 mass parts, there exists a concern that storage stability falls.

Further, when (D) a polyfunctional (meth) acrylate is further added to the curable resin composition of the present invention, (A) a thioether-containing (meth) acrylate derivative and (B) The total mass ((A) + (B)) of the polyfunctional epoxy resin is 100 parts by mass, and 2 to 300 parts by mass of (D) polyfunctional (meth) acrylate is added, preferably 2 to 250 parts by mass. When the amount of the component (D) is less than 2 parts by mass based on 100 parts by mass of ((A) + (B)), it is difficult to impart photocurability, and if it exceeds 300 parts by mass, the adhesion is lowered. Propensity.

Further, in the case where (E) a photopolymerization initiator is added to the curable resin composition of the present invention, (A) a thioether-containing (meth) acrylate derivative and (D) a polyfunctional group are added. 100 parts by mass of the total mass ((A) + (D)) of (meth) acrylate, 0.01 to 10 parts by mass of (E) photopolymerization initiator is added, preferably 0.01 to 5 parts by mass. The amount of the (E) component is less than 0.01 mass relative to 100 parts by mass of ((A) + (B)) In the case of the amount of the component, it is difficult to promote photocuring, and if it exceeds 10 parts by mass, it is too large and unnecessary, which is not preferable.

<Formation of cured film>

The curable resin composition of the present invention is applied to a substrate and cured to form a cured film. The curable resin composition of the present invention exhibits adhesion to a substrate due to the thioether group of the (A) thioether-containing (meth) acrylate derivative. Therefore, the substrate is excellent in adhesion improving effect to a substrate having a chemical bond (high chemical affinity) with a thioether group, for example, a transition metal or an alloy thereof, or a ruthenium compound, a phosphorus compound, a sulfur compound, or a boron compound. An inorganic substrate; an organic substance having an unsaturated bond (including an aromatic ring), an organic substance having a hydroxyl group or a carboxyl group, or an organic substrate such as a plasma or a UV ozone-treated organic substance. Specifically, examples of the inorganic substrate include glass, enamel, various metals, and the like. As the organic substrate, a poly(meth)acrylic resin, a cellulose triacetate (TAC) resin, polyethylene terephthalate (PET) or polybutylene terephthalate is preferably used. Polyester resin, polycarbonate resin, polyimide resin, polyolefin resin such as polyethylene or polypropylene, polycarbonate, polyimine, ABS resin, polyvinyl alcohol, vinyl chloride resin , polyacetal, and the like. Further, in the curable resin composition of the present invention, since the (A) thioether-containing (meth) acrylate derivative has a specific hydrocarbon group, the cured film is excellent in flexibility. Therefore, even in cold conditions, the cured film easily follows the substrate and is excellent in adhesion to the substrate. It can thus be used particularly suitably for the coating of flexible substrates which can be used under cold conditions.

The curable resin composition of the present invention can be cured by heating. The heating temperature is about 25~250 °C. Further, when the curable resin composition contains the component (D), it can be cured by irradiation of light. Examples of the irradiation light include active energy such as UV (ultraviolet rays) and EB (electron beam). Measuring line and so on. When the (C) component is contained, the curable resin composition can also be cured by a double process of a light irradiation curing process and a heated curing process.

In order to make the reaction system uniform and easy to apply, the curable resin composition of the present invention can be used after being diluted with an organic solvent. Examples of such an organic solvent include an alcohol solvent, an aromatic hydrocarbon solvent, an ether solvent, an ester solvent, and an ether ester solvent, a ketone solvent, and a phosphate solvent. The amount of these organic solvents added is preferably controlled to be less than 10,000 parts by mass with respect to 100 parts by mass of the curable resin composition, but substantially the solution volatilizes when the cured film is formed, so that the physical properties of the cured film are not greatly affected. . However, since a compound having a functional group reactive with a thiol group, an epoxy group or a (meth) propylene group and an amine compound are used as a solvent, the effects of the present invention may be impaired.

In addition, a viscosity modifier such as cerium oxide powder may be added to the curable resin composition of the present invention for the purpose of adjusting the viscosity. It is preferable to control the addition amount of these viscosity modifiers to less than 300 mass parts with respect to 100 mass parts of curable resin composition. If the mixing amount of the viscosity modifier exceeds 300 parts by mass, the adhesion may be lowered.

Further, the curable resin composition of the present invention may also contain various additives which can be used in ordinary paints or adhesives. As such an additive, a surfactant for smoothing the coated surface and an aluminum salt for extending the usable time can be exemplified. It is preferable to control the mixing amount of these additives to less than 80 parts by mass with respect to 100 parts by mass of the curable resin composition. If the amount of these additives is more than 80 parts by mass, the adhesion may be lowered.

Example

The present invention will be more specifically described below by way of examples and comparative examples, but the invention is not limited thereto. The reagents used in the examples and comparative examples are as follows. Further, Mw represents a weight average molecular weight.

<(A) component>

(A-1: a thioether-containing (meth) acrylate derivative)

(A-2: a thioether-containing (meth) acrylate derivative)

(A-3: (meth) acrylate derivative containing a sulfide)

(A-4: a thioether-containing (meth) acrylate derivative)

(A'-1: polythiol)

(A'-2: alkoxydecane derivative containing a sulfide)

(A'-3: alkoxydecane derivative containing a sulfide)

(A'-4: a sulfide-containing (meth) acrylate derivative)

<Multifunctional epoxy resin ((B) component)>

(B-1, Mw: 5500)

(B-2, Mw: 220)

(B-3, Mw: 18000)

Copolymer of glycidyl methacrylate and cyclohexyl methacrylate (functional group ratio 1:1) (white solid obtained by reprecipitation of 50 wt% methyl isobutyl ketone solution with hexane)

(B-4, Mw: 45000)

Copolymer of glycidyl methacrylate and cyclohexyl methacrylate (functional group ratio 1:1) White solid obtained by reprecipitation of 50% by weight of methyl isobutyl ketone solution by hexane)

<Amine compound ((C) component)>

(C-1, Mw: 110)

(C-2, Mw: 102)

N,N-dimethyl-1,3-propanediamine

(C-3, Mw: 680)

(n1, n2, and n3 are integers of 1 to 5, and an average of 3.5 mixtures)

<Polyfunctional (meth) acrylate ((D) component)>

(D-1, Mw: 352)

(D-2, Mw: 246)

(D-3, Mw: 5000)

(n average is 13)

(D-4, Mw: 22000)

Equivalent addition of methacrylic acid polymer to a 50% by weight solution of methyl isobutyl ketone with hexane on a copolymer of glycidyl methacrylate and cyclohexyl methacrylate using C-3 as a catalyst White solid obtained by reprecipitation)

(D-5, Mw: 45000)

Equivalent addition of methacrylic acid polymer to a 50% by weight solution of methyl isobutyl ketone with hexane on a copolymer of glycidyl methacrylate and cyclohexyl methacrylate using C-3 as a catalyst White solid obtained by reprecipitation)

<Photopolymerization initiator ((E) component)>

(E-1, Mw: 204)

1-hydroxy-cyclohexyl-phenyl-one

(E-2, Mw: 348)

2,4,6-trimethylbenzimidyl-diphenyl-phosphine oxide

(E-3, Mw: 407)

2-(9-oxanthene-2-yl)propionic acid 1,5,7-triazabicyclo[4.4.0]non-5-ene

<Curable resin composition>

Each of the components (A) to (E) was mixed with the amount of the composition shown in the following Tables 1 to 4, and the mixture was stirred until uniform with a spatula to obtain a curable resin composition of each of the examples and the comparative examples. The following curable resin composition was used to carry out the following adhesion 1 (room temperature adhesion), adhesion 2 (cold area adhesion), adhesion 3 (photocurability), flexibility, and storage stability. Evaluation. The results are shown in Tables 1 to 4.

[Production of Test Piece 1 for Evaluation]

The test piece for evaluation of adhesion 1, adhesion 2, and flexibility was obtained as follows. Each curable resin composition was applied onto a 25 mm-wide PET film with a thickness of 100 μm by a die coater, and another PET film was superposed thereon, and then cured at 150 ° C for 1 hour. Test piece 1 for evaluation. In addition, Lumirror U46-100 manufactured by Toray Industries, Inc. was used as the PET film.

[Production of Test Piece 2 for Evaluation]

The test piece for evaluation of the adhesiveness 3 was obtained as follows. Each of the curable resin compositions was applied to a PET film having a width of 25 mm and a length of 150 mm by a die coater, and after superimposing another PET film thereon, the high-pressure mercury lamp was irradiated with a light irradiation amount of 500 mJ/cm ² . The light for the evaluation (i-line conversion) was subjected to the evaluation test piece 2A, and the light of the high-pressure mercury lamp (i-line conversion) was irradiated with a light irradiation amount of 3000 mJ/cm ² to obtain a test piece 2B for evaluation. In addition, Lumirror U46-100 manufactured by Toray Industries, Inc. was used as the PET film.

[Adhesiveness 1 (room temperature attachment)]

The test piece 1 for evaluation was allowed to stand at 25 ° C for 24 hours, and then measured by a T-peel method defined in JIS K6854-3 as a standard, and evaluated as follows.

◎: Tensile strength is 5N/25mm or more (PET film breakage)

○: Tensile strength is SN/25 mm or more (PET film is not broken)

×: less than 5N/25mm

[Attach 2 (cold area attachment)]

The test piece 1 for evaluation was allowed to stand at -10 ° C for 24 hours, and then measured by a T-peel method defined in JIS K6854-3 as a standard, and evaluated as follows.

◎: Tensile strength is 5N/25mm or more (PET film breakage)

○: Tensile strength is 5 N/25 mm or more (PET film is not broken)

×: less than 5N/25mm

[Adhesiveness 3 (Photocuring)]

In the test pieces 2A and 2B for evaluation, the test piece for evaluation was held by both hands, and a PET film was stretched in the width direction, and the relative displacement with respect to the other PET film was visually observed (width direction). Misplaced), evaluation.

◎: No test pieces 2A and 2B were used for evaluation.

○: Only the evaluation test piece 2B has no misalignment

×: The test pieces 2A and 2B for evaluation were misaligned.

[softness]

The test piece 1 for evaluation was allowed to stand at -10 ° C for 24 hours, and then wound on a rod having a diameter of 8 mm for 1 minute, and visually observed and evaluated as follows.

○: no cracks

×: cracked

[save stability]

The viscosity (concentration after mixing) of the curable resin composition of each of the examples and the comparative examples immediately after mixing was measured, and the viscosity (viscosity after heating) after heating at 40 ° C for 12 hours was measured again, and after heating. The viscosity is divided by the viscosity after mixing, and the viscosity increase rate is calculated as follows. In addition, the viscosity was measured by the R-type viscometer manufactured by Toki Sangyo Co., Ltd. under the following conditions.

Rotor used: 1°34’×R24

Measuring range: 0.5183~103.7Pa ̇s

◎: viscosity increase rate 1.0~1.8

○: viscosity increase rate 1.8~10

×: The viscosity increase rate is outside the above range

In the curable resin compositions of Examples 1-1 to 1-17, high adhesion at room temperature and cold conditions, good flexibility, and excellent storage stability were observed. On the other hand, in Comparative Examples 1-5 to 1-8 using a compound which does not satisfy the above formula 1 as the component (A), the adhesion and the flexibility under cold conditions were insufficient. In Comparative Examples 1-1 and 1-2 in which the component (A) is too small or too large relative to the component (B), The adhesion is poor only in cold conditions, and the adhesion at normal temperature is also poor. Among them, in Comparative Example 1-1 in which the component (A) was too small relative to the component (B), flexibility was lacking. In Comparative Example 1-3 in which the component (C) was not added, the adhesion was lacking. In Comparative Example 1-4 in which the component (C) was excessively added to the component (A) and the component (B), the storage stability was poor. Further, it was confirmed by Examples 2-1 to 2-10 that photocurability can be imparted by adding the component (D). It was also confirmed by Examples 3-1 to 3-5 that the addition of the component (E) enables curing with less light irradiation.

Claims (3)

A curable resin composition comprising: (A) a thioether-containing (meth) acrylate derivative represented by the following formula 1: (B) a polyfunctional ring having a weight average molecular weight of 200 to 50,000. An oxygen compound; and (C) an amine compound having a weight average molecular weight of 90 to 700, wherein the mass ratio (A)/(B) of the component (A) to the component (B) is 0.05 to 30, relative to the (A) component and 100 parts by mass of the total mass of the component (B), and 0.01 to 1 part by mass of the component (C) is added. In the formula, a is an integer of 1 to 3, b is 0 or 1, c is an integer of 1 to 3, a sum of b and c is 4; and R ¹ is a methylene group or an ethylene group. Or isopropylidene; R ² is a divalent functional group represented by the following formula 2 or the following formula 3; R ³ is a methyl group or an ethyl group; and R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms; R ⁵ is a hydrogen atom or a methyl group. R ⁵ is a hydrogen atom or a methyl group. A curable resin composition comprising the following components: (A) component, (B) component, (C) component, and (D) weight average molecular weight of 200 to 50,000. In the curable resin composition, 0.01 to 1 part by mass of the component (C) is added to 100 parts by mass of the total mass of the component (A) and the component (B). Further, 2 to 300 parts by mass of the component (D) is further added. A curable resin composition which is composed of the following components: (A) component, (B) component, (C) component, and (D) component in the second item of the patent application scope. And (E) a photopolymerization initiator, wherein the curable resin composition is added in an amount of 0.01 to 1 part by mass based on 100 parts by mass of the total mass of the component (A) and the component (B). And the component (D) is further added in an amount of from 0.01 to 10 parts by mass based on 100 parts by mass of the total mass of the component (A) and the component (D). .