JPS6138931B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a curing composition containing a spiroorthoester compound having at least one spiroorthoester group represented by the above formula [1] (hereinafter simply referred to as spiroorthoester). Regarding the spiroorthoester group,
W.J.Bailey, Journal of Macromolecular
Science, Chemistry, A9(5), 849-865 (1975)
As a result of various studies on the chemical properties of spiro-orthoesters, the present inventors found that an epoxy compound and a spiro-orthoester undergo ring-opening copolymerization with a cationic polymerization catalyst or an organic acid curing agent. I found this. Spiroorthoesters are produced, for example, by reaction of epoxy compounds with lactones. To illustrate its production method, a lactone such as γ-butyrolactone, δ-valerolactone or ε-caprolactone and a catalyst such as BF ₃ OEt ₂ are dissolved in a suitable solvent such as carbon tetrachloride or methylene chloride, and the reaction temperature is adjusted. A solution of an epoxy compound dissolved in a suitable solvent is added dropwise under controlled conditions to react. The reaction temperature at this time is generally in the range of 0° to 30°C. The ratio of the lactone to the epoxy compound is not limited, but it is generally carried out at a ratio of 1 equivalent or more of the lactone to 1 equivalent of the epoxy group. In some cases, the proportion may be less than 1 equivalent. The spiro-orthoester can be separated and obtained from the reaction solution by directly removing the solvent, or by removing the solvent after washing with an alkali to remove the lactone, or, if necessary, by solvent purification such as vacuum distillation or recrystallization. To do something. As an example, phenyl glycidyl ether and γ-
The reaction of butyrolactone is expressed by the following formula. The cationic polymerization of spiro-orthoesters is described in the above-mentioned literature, but the fact that spiro-orthoesters undergo cationic ring-opening copolymerization with epoxy compounds, and ring-opening copolymerization with epoxy compounds and organic acid curing agents is not known. This was not well known, and the present inventors obtained an unexpected finding. In general, thermosetting resins always undergo volumetric shrinkage during curing. For example, although epoxy resin is on the smaller side, it still exhibits a volume shrinkage of about 3 to 6%. If the volumetric shrinkage during curing is large, for example, when used as a molding material, dimensional accuracy may be lost, when used as a casting material, the filling material may be distorted due to shrinkage, or the adhesive strength with the mold may be reduced. There are problems such as the formation of gaps. Furthermore, when used as a paint, it causes problems in use such as reduced adhesion to the painted plate and warping due to internal strain, and when used as an adhesive, internal strain causes reduced adhesion, warping, and deformation. On the contrary,
As mentioned above, the spiro-orthoester constituting the composition of the present invention can be easily synthesized by a simple reaction from a commercially available epoxy compound and γ-butyrolactone, δ-valerolactone, or ε-caprolactone, and can be polymerized. It also has the feature of very small volumetric shrinkage. For example, the volume shrinkage rate due to cationic polymerization of spiroorthoester [A] produced from diglycidyl ether type epoxy of bisphenol A and γ-butyrolactone (described later) is approximately 0.6%, and bisphenol A Determine the volumetric shrinkage rate when a spiro-orthoester (spiro-orthoester [B] described below) produced from diglycidyl ether type epoxy and ε-caprolactone is cured using dodecenyl succinic anhydride as an organic acid curing agent. It is approximately 0.7%, which is very small compared to general thermosetting resins, etc.The volumetric shrinkage rate (%) is [1 - (specific gravity of the composition before polymerization/specific gravity of the polymer)] × 100. The composition of the present invention thus contains a spiro-orthoester as a copolymerization component, which has a small volume shrinkage during polymerization and curing. When used as an adhesive, the composition of the present invention has the advantage of having a smaller volumetric shrinkage rate when cured than a composition containing no spiro-orthoester. It also has the advantage of having a higher peel strength compared to other types of epoxy, such as Epicote 828 Ciel Chemical, which is a diglycidyl ether type epoxy of bisphenol A. A composition in which dodecenyl succinic anhydride is blended as an organic acid curing agent into a mixture of 50 parts by weight of spiro-orthoester [B] and 50 parts by weight of spiro-orthoester [B] (manufactured by Co., Ltd.) is a composition in which dodecenyl succinic anhydride is blended as an organic acid curing agent. The peel strength was approximately twice as high as that of a composition with the same composition except for the point where the laminate was not stained. As described above, the composition of the present invention is extremely useful for use in molding materials, composite materials, adhesives, casting materials, paints, and the like. The epoxy compound constituting the composition of the present invention is
Epoxy compounds containing one or more epoxy groups in one molecule, such as 2,2'-bis(4'-hydroxyphenyl)propane (commonly known as bisphenol A),
Halogenated bisphenol A, bis(4-hydroxyphenyl)methane (commonly known as bisphenol F), resorcinol, tetrahydroxyphenylmethane, novolac type polyfunctional phenol condensed from phenol or cresol and formalin, phenol, cresol, t -Glycidylethyl, β-methylglycidyl ether [hereinafter both referred to as (β-methyl)epichlorohydrin] obtained by reacting a phenolic compound such as butylphenol with epichloridrine or β-methylepichlorohydrin (hereinafter both referred to as (β-methyl)epichlorohydrin). (Represented as (β-methyl)glycidyl ether.)
Polyglycidyl ether or poly(β-methylglycidyl) ether (hereinafter referred to as poly((β-
methyl)glycidyl)ether. ) etc. In addition, alcohols such as butyl alcohol, allyl alcohol, ethylene glycol, polyethylene glycol, 2,2'-bis(4'-hydroxycyclohexyl)propane, glycerin, 1,1,1-trimethylolpropane, and (β-methyl)epichlorohydrin are used. Also included are (β-methyl)glycidyl ether or poly((β-methyl)glycidyl)ether obtained by the reaction. In addition, (β-methyl)glycidyl is obtained by reacting (β-methyl)epichlorohydrin with a compound having a carboxyl group such as benzene monocarboxylic acid, adipic acid, sebacic acid, phthalic acid, hexahydrophthalic acid, and tetrahydrophthalic acid. Esters and poly((β-methyl)glycidyl) esters and the like can also be used. Furthermore, epoxidized olefin, epoxidized polybutadiene, epoxidized synthetic oil, cyclopentadienated epoxy,
Nitrogen-containing epoxy such as aniline-modified epoxy, nitrogen-containing heterocyclic epoxy obtained from isocyanuric acid epoxy, hydantoin derivatives or imidazoline derivatives, styrene oxide obtained from monounsaturated compounds, or synthesized by oxidizing double bonds in the molecule. An internal epoxy type compound manufactured by Chitsuso Co., Ltd. (trade name: Chitsusonox)
201, 221, 289, 206, 207, 1222 Ciba Product Co., Ltd. Product name Araldite CY-175, CY-176, CY-
178, CY-179, etc. can also be used. In the composition of the present invention, one or more of the epoxy compounds exemplified above may be blended. As the spiro-orthoester constituting the composition of the present invention, a spiro-orthoester produced by reacting a lactone such as γ-butyrolactone, δ-valerolactone, or ε-caprolactone with the above-mentioned epoxy compound is used. For example, 1,4,6-trioxaspiro[4,
4] Nonane, 2-methyl-1,4,6-trioxaspiro[4,4]nonane, 2-chloromethyl-
1,4,6-trioxaspiro[4,4]nonane, 2-phenoxymethyl-1,4,6-trioxaspiro[4,4]nonane, 1,4,6-trioxaspiro[4,5] Decane, 2-chloromethyl-1,4,6-trioxaspiro[4,6]undecane, 2,3-dimethyl-1,4,6-trioxaspiro[4,6]undecane, 2-methylene-1, Spiroorthoesters having one spiroorthoester group such as 4,6-trioxaspiro[4,4]nonane, 2-methylene-1,4,6-trioxaspiro[4,6]undecane, etc.
diglycidyl ethyl of bisphenol A, 2,
Spiroortho containing two or more spiroorthoester groups made by reacting a lactone with an epoxy compound such as diglycidyl ether of 2-bis(4'-hydroxyhexyl)propane or triglycidyl ether of 1,1,1-trimethylolpropane. Esters and mixtures of these can also be used. A preferred spiro-orthoester is a compound having one or more spiro-orthoester groups in the molecule, and is represented by the following formula [2]. Y(-A)m [2] Here, m is an integer greater than or equal to 1, and A is or , (B) in organic group [4] represents a substituted or unsubstituted cycloalkylene group, and Y in formula [2] is an epoxy group of an epoxy compound (including an internal epoxy group of alicyclic epoxy)
Represents residues excluding R ¹ , R ² , in organic groups [3] and [4],
R ³ , R ¹ ′, and R ² ′ each represent a hydrogen atom, alkyl, haloalkyl, or alkenyl group, and n is 3
represents an integer of ~5, and Y in formula [2] and R ¹ in organic group [3] can be combined to form one methylene group. The general formula for the synthesis reaction of spiro-orthoester is as follows. To give a few specific examples, the reaction between phenyl glycidyl ether and γ-butyrolactone is as described above, and the reaction between alicyclic epoxy compounds such as Chitsonox 221 (trade name manufactured by Chitso Corporation) and ε-
The reaction with caprolactone is expressed by the following formula. The value of n in the organic group [3] or [4] of the spiroorthoester to be produced is 3 when the lactone is γ-butyrolactone, 4 when the lactone is δ-valerolactone, and 5 when the lactone is ε-caprolactone. Spiroorthoester derivatives made from epoxy compounds and lactones can also be used. For example, in the methylene group-containing spiro-orthoester shown by the following formula, which is produced by dehydrohalogenation reaction of a spiro-orthoester, that is, the methylene group-containing spiro-orthoester of the above formula [2], Y and R ¹ are combined to form a methylene group. There are compounds that have formed . Here, n is an integer from 3 to 5. Furthermore, as a specific example, 2-chloromethyl-
The deHC reaction of 1,4,6-trioxaspiro[4,6]undecane is expressed by the following formula. There is also a spiro-orthoester produced by introducing a spiro-orthoester group into the molecule, for example, by a dehalogenated Na reaction. For example, phenol Na salt and 2-bromomethyl-1,
Deletion of 4,6-trioxaspiro[4,4]nonane
The NaBr reaction is expressed as the following equation. Such spiroorthoesters can also be used in the present invention. The blending ratio (by weight) of the spiro-orthoester and the epoxy compound in the composition of the present invention is such that if the spiro-orthoester is too small, shrinkage and adhesion during curing will not be sufficiently improved; Since the glass transition temperature tends to be low, the heat resistance tends to decrease, and the composition also becomes expensive, the desirable blending ratio of spiro-orthoester is 10% based on the total amount with the epoxy compound.
~95, more preferably 3090. As the cationic polymerization catalyst which is another component of the composition of the present invention, for example, φ-N ⁺ ≡N・PF ^- , φ-N ⁺
Aromatic diazonium salts such as ≡N・BF4 ⁻ ; Aromatic halonium salts such as φ−I ⁺ −φ・BF ⁻ ; Aromatic onium salts of Group Va elements of the periodic table, such as; Examples include aromatic onium salts of Group A elements of the periodic table. In addition, other catalysts for cationic polymerization include, for example, BF ₃ , FeC ₃ , SnC ₄ , SbC
Lewis acids such as ₅ , SbF ₃ and TiC ₄ ;
BF ₃ OEt ₂ , BF ₃ - Coordination compounds of Lewis acids such as aniline complexes and compounds containing O, S, N, etc.; oxonium salts, diazonium salts, carbonium salts, halogen compounds of Lewis acids,
Examples include mixed halogen compounds and perhalogen acid derivatives. The amount of catalyst for cationic polymerization is usually in the composition.
A range of 0.001 to 10 wt% is suitable. The organic acid curing agent that can constitute the composition of the present invention is suitably a polybasic carboxylic acid used as a curing agent for epoxy compounds or its acid anhydride.
Examples include succinic acid, methylsuccinic acid, dodecenylsuccinic acid, dichlorosuccinic acid, azelaic acid, sebacic acid, itaconic acid, maleic acid, citraconic acid, phthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, methyl Hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, tricarballylic acid, trimellitic acid, pyromellitic acid, cyclopentane-1,2,3,4-tetracarboxylic acid, benzophenone-3,3', 4,4'-tetracarboxylic acid and their acid anhydrides, mixtures of two of these, or mixtures of these with monobasic carboxylic acid anhydrides, and linoleic acid of maleic anhydride. It is also possible to use derivatives thereof, such as adducts, which have a carboxylic acid or its acid anhydride structure at the terminal or side chain of the molecule obtained from the polybasic carboxylic acid or its acid anhydride. Generally, acid anhydrides as curing agents have a slow curing speed, and therefore, a suitable curing accelerator is usually used in combination to shorten the curing time, and such a combination is also effective in the present invention. Suitable promoters include tertiary amines, quaternary ammonium salts, imidazole compounds, pyridine, dicyandiamide, chelate compounds, metallocenes, and the like. The most appropriate amount of the organic acid curing agent is determined depending on the chemical properties of the curing agent, the properties required for the curing composition and the cured product, etc. If you use
It is desirable to use about 0.1 to 1.5 and preferably about 0.2 to 1.3 equivalents of carboxylic acid or carboxylic acid anhydride per equivalent of the sum of spiro-orthoester group equivalents and epoxy group equivalents in the composition. The amount of curing accelerator used is usually preferably 0.2 to 3 parts by weight per 100 parts by weight of the epoxy compound, spiro-orthoester compound and curing agent. There are no particular restrictions on the polymerization or curing temperature of the composition of the present invention, but it is usually carried out at 0°C to 200°C. Various additives may be added to the composition of the present invention as necessary. Examples of such additives include, for example, glass fibers, carbon fibers, mica, quartz powder, calcium carbonate, cellulose, kaolin, talc, aluminum powder, colloidal silica with a large specific surface area, powdered polyvinyl chloride, and polyethylene. and powdered polyolefins such as polypropylene. Fillers such as silica, talc,
Volume shrinkage can be further reduced by adding potassium carbonate, alumina, etc. Further, the curable composition according to the present invention may contain a non-reactive diluent, a flame retardant, a flexibility imparting agent, and other modifiers, if necessary. Examples of the above-mentioned flame retardants include halogen flame retardants (eg, hexabromobenzene), inorganic flame retardants (eg, hydrated alumina, phosphates), and the like. Further, examples of the non-reactive diluent include dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, tar, and the like. In addition, as the flexibility imparting agent, polysulfide,
Examples include polyamide, polyalkylene polyol, and elastomer. The present invention will be explained in detail with reference to Examples below. The spiroorthoesters [A], [B] and [C] used in the Examples were produced as follows. Among them, the main component [A] is represented by the following structural formula. Spiroorthoester [A]; In a 4-necked 500 ml flask equipped with a stirrer, condenser, thermometer, and dropping funnel, add methylene chloride.
200 ml and 103.2 g (1.2 moles) of γ-butyrolactone were added. This solution was cooled to about 10° C. with ice water, and 0.8 ml of BF ₃ OEt ₂ was added. Next is Epicote
828 Ciel Chemical Co., Ltd. epoxy resin product name) 152g
A mixed solution of (0.4 mol) and 100 ml of methylene chloride was added dropwise with stirring over 1 hour. Furthermore, at a temperature of 25℃ 4
After reacting for an hour, 1.6 ml of triethylamine was added to deactivate the catalyst. Next, in order to remove excess γ-butyrolactone, the reaction solution was washed twice with an alkali solution of 500 ml of 5% NaOH aqueous solution, and the organic layer was separated by centrifugation. Next 250ml
After washing with distilled water, the organic layer was centrifuged, and the organic layer was dehydrated over magnesium sulfate overnight, and then the solvent was removed to obtain 188 g of spiro-orthoester [A]. The product was a colorless, transparent, viscous liquid with a specific gravity of 1.213 at 25°C. Also, the viscosity is 50℃
It was approximately 250,000 centipoise. Spiroorthoester [B]; 200 methylene chloride in a 4-neck flask equipped with a stirrer, condenser, thermometer and dropping funnel.
ml and 136.8 g (1.2 mol) of ε-caprolactone were added. This solution was cooled to about 10°C with ice water,
1 ml of BF ₃ OEt ₂ was added. Next, increase the temperature of the reaction solution to approx.
While maintaining the temperature at °C, a mixed solution of 114 g (0.3 mol) of Epicote 828 epoxy resin (trade name, manufactured by Ciel Kagaku Co., Ltd.) and 500 ml of methylene chloride was added dropwise with stirring over 5 hours. After further reacting at this temperature for 3 hours,
The catalyst was deactivated by adding 3 ml of triethylamine. Next, in order to remove excess ε-caprolactone, the reaction solution was alkaline washed twice with 500 ml of 6% NaOH aqueous solution, centrifuged, washed twice with 300 ml of distilled water, and then centrifuged. The organic layer was dehydrated with magnesium sulfate overnight and then the solvent was removed to obtain 131 g of spiroorthoester [B]. The product is a pale yellow transparent viscous liquid whose specific gravity is 25°C.
It was 1.178. The viscosity was approximately 98,000 centipoise at 50°C. Its main components are shown by the structural formula below. Production of spiroorthoester [C] Methylene chloride was placed in a four-neck flask equipped with a stirrer, condenser, thermometer, and dropping funnel.
200 ml and 136.8 g (1.2 mol) of ε-caprolactone were added. The solution was cooled to about 10° C. with ice water and 1 ml of BF ₃ OEt ₂ was added. Next, while keeping the temperature of the reaction solution at about 10℃, calculate the chemical formula. Alicyclic epoxy resin Chitsusonox-221 (trade name of epoxy resin manufactured by Chitsuso Co., Ltd.) 82g
A mixed solution of (approximately 0.3 mol) and 300 ml of methylene chloride was added dropwise over 1 hour with stirring. After further reacting at this temperature for 3.5 hours, 3 ml of triethylamine was added to deactivate the catalyst. Next, in order to remove excess ε-caprolactone, the reaction solution was alkaline washed twice with 500 ml of 6% NaOH aqueous solution, then centrifuged, washed twice with 300 ml of distilled water, and centrifuged. After dehydrating the organic layer with magnesium sulfate overnight,
The solvent was removed to obtain 101 g of spiroorthoester [C]. The product was a pale yellow transparent semi-solid with a specific gravity of 1.211 at 25°C. The viscosity was 1.7 million centipoise at 60°C. Its main component is represented by the following structural formula. Example 1 A mixture of 50 parts of Epicote 828 (trade name manufactured by Ciel Kagaku Co., Ltd.) (same parts below by weight) and 50 parts of spiroorthoester [A] was added as a cationic polymerization catalyst.
Add 3 parts of monoethylamine complex compound of BF ₃ ,
After 4 hours at 120℃, then 6 hours at 150℃
Allowed to cure for hours. The shore hardness of this cured product was D-86. Further, the volume shrinkage rate due to curing, determined from the specific gravity of the composition and the specific gravity of the cured resin at 25°C, was only about 2.4%. Comparative Example 1 3 parts of a monoethylamine complex compound of BF ₃ was added to 100 parts of Epicote 828 (trade name, manufactured by Ciel Kagaku Co., Ltd.), and polymerization was carried out under the same conditions as in Example 1. The shore hardness of this hard material was D-89. The volumetric shrinkage rate due to curing reached approximately 3.7%. Example 2 A mixture of 50 parts of Epicote 828 (trade name manufactured by Ciel Kagaku Co., Ltd.) and 50 parts of spiro-orthoester [B] was mixed with 54 parts of dodecenyl succinic anhydride as an organic acid curing agent and 1-cyanoethyl-2 as a curing accelerator. - 1.5 parts of methylimidazole was added and cured at 120°C for 4 hours and then at 150°C for 6 hours. The shore hardness of this cured product was D-82. The volumetric shrinkage rate due to curing was approximately 2.3%. Example 3 Comparative Example 2 Aluminum (thickness 0.6 mm) and cold rolled steel plate [JISG-
3141 SPCCD (thickness 0.3 mm)] in Example 2.
Performed under the same curing conditions as JIS K 6854-1977
The T-peel strength was measured according to . The adherend used was one that had been degreased with acetone.

[Table] The results are as shown in the table above, and the composition of the present invention containing spiroorthoester [B] exhibited adhesive strength about twice or more than that of the composition without spiroorthoester [B]. Examples 4 and 5 Steel and glass (thickness: 5 mm) were bonded using a composition having the composition shown below, and the tensile shear adhesive strength was measured. Adhesion is further maintained at 120°C for 5 hours after application of the composition.
Performed by curing at 150℃ for 2 hours, JIS
Tensile shear strength was measured according to K 6850-1977. The iron of the test piece was surface-treated by sandblasting using alumina #100, and the glass was degreased with acetone.

[Table] Example 6 50 parts of 2-phenoxymethyl-1,4,6-trioxaspiro[4,4]nonane and hydrogenated bisphenol A type epoxy resin “ADEKA RIN EP”
A composition consisting of 50 parts of 4080" [trade name manufactured by Asahi Denka Kogyo Co., Ltd.] and 3 parts of a monoethylamine chain compound of BF ₃ was prepared.
It was cured at 120°C for 5 hours to obtain a soft cured product. Further, the volume shrinkage rate due to curing was approximately 2.6%. Example 7 50 parts of 2-methylene-1,4,6-trioxasbicyclo[4,6]undecane and Dinacol EX, a polyglycidyl ether of glycerin
-313 [Nagase Sangyo Co., Ltd. product name] To a mixture of 50 parts, 97 parts of hexahydrophthalic anhydride as an organic acid curing agent and 2.0 parts of tris(dimethylaminomethyl)phenol as a curing accelerator were added and oxidized. The composition was cured at 120°C for 5 hours and then at 150°C for 3 hours. The shore hardness of this cured product was A-65. The volume shrinkage rate due to curing was approximately 4.6%. Comparative example 3 Danacol EX-313 [Nagase Sangyo Co., Ltd. product name]
100 parts of hexahydrophthalic anhydride as a cured product
103 parts and 2.0 parts of tris(dimethylaminomethyl)phenol as an accelerator were added and cured in the same manner as in Example 7 to obtain a hard cured product. The volume shrinkage rate due to this curing was approximately 6%. Example 8 To a mixture of 50 parts of alicyclic epoxy resin Chitsonox 289 (trade name manufactured by Chitso Corporation) and 50 parts of spiroorthoester [C], 51 parts of hexahydrophthalic anhydride as a curing agent and Tris ( 1.5 parts of dimethylaminomethyl)phenol was added, and the mixture was kept at 120°C for 4 hours and then at 150°C for 6 hours to cure. The shore hardness of this cured product was D-85. Further, the volume shrinkage rate due to curing was approximately 2.6%.

Claims (1)

[Scope of Claims] 1. A spiro-orthoester compound having at least one spiro-orthoester group represented by the following formula [1], an epoxy compound having at least one epoxy group, and a cationic polymerization catalyst and/or an organic acid curing agent A curing composition consisting of: In the above formula, n represents an integer of 3 to 5.