JPS6228973B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a curing composition containing a bicycloorthoester compound having at least one bicycloorthoester group (hereinafter simply referred to as bicycloorthoester), which has an extremely small volumetric shrinkage rate during curing and is suitable for molding materials. , a curing composition suitable for casting materials, adhesives, etc. It is generally known that thermosetting resins undergo considerable volumetric shrinkage upon curing. For example, although epoxy resin is the smallest, it still exhibits a volumetric shrinkage rate of about 2 to 6% upon curing. 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 gaps and 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. For these reasons, there is a strong demand for a curable composition that exhibits extremely small volume shrinkage during curing. For bicycloorthoesters,
American Chemical Society, Division of
Polymer Chemistry, Inc., 21 , 4-5 (1981)
As a result of various studies on the chemical properties of bicycloorthoesters, the present inventors found that such compounds not only undergo cationic polymerization with cationic polymerization catalysts, but also can be used for phenolic resins, organic polybasic acids, The present inventors have discovered that ring-opening polymerization is possible with a curing agent selected from organic polybasic acid anhydrides and carboxylic acid type polyesters, and that the volume shrinkage upon curing is extremely small, leading to the completion of the present invention. . The bicycloorthoester constituting the composition of the present invention is a compound having one or more bicycloorthoester groups represented by formula [1] in its molecule, and includes, for example, a compound represented by the following general formula.

【formula】

[Formula] However, the meanings of the symbols in the above general formula are as follows. m: an integer of 2 or more. R ¹ hydrogen atom; alkyl group, such as a linear or branched alkyl group ranging from a methyl group with 1 carbon number to an octadecyl group with 18 carbon atoms; cycloalkyl group, such as cyclopentyl, cyclohexyl, cyclopentyl, etc.;
Aralkyl groups such as benzyl, phenylethyl, phenylpropyl and phenylisopropyl; aryl groups such as phenyl, biphenyl, xenyl and naphthyl; tolyl, xylyl, ethyl phenyl, propylphenyl, isopropylphenyl and butylphenyl. alkaryl group; hydroxyalkyl group such as hydroxymethyl; unsaturated group-substituted oxymethyl group such as acryloyloxymethyl, methacryloyloxymethyl and vinylbenzyloxymethyl group;
or residues of urethane compounds having carbamoyloxymethyl groups, such as N-ethylcarbamoyloxymethyl and N-phenylcarbamoyloxymethyl. R ² : Hydrogen atom; an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, an alkaryl group, such as the specific examples given for R ¹ above; for example, a linear or branched group ranging from hydroxymethyl to hydroxyoctadecyl; Monohydroxyalkyl groups; or linear or branched alkenyl groups such as vinyl, α-methylvinyl, β-methylvinyl, α-ethylvinyl and propenyl to octadecenyl. R ³ : An organic group represented by the following general formula [] or []. Y [-NHCOOCH _{2 -} ] _{n [ ]} A group obtained by removing at least m isocyanates from a urethane compound having isocyanate groups. X is a group obtained by removing at least m epoxy groups from a polyepoxy compound. R ⁴ : Hydrogen atom; an alkyl group, an aralkyl group, or an aryl group as exemplified above for R ¹ . A and B: A and B are mutually the same or different polymer structural units selected from ethylenically unsaturated compounds. x and y: molar fraction of polymer constitutional units A and B. The bicycloorthoesters exemplified above can be produced by various methods. For example, regarding the bicycloorthoester represented by the general formula [2], American Chemical Society, Division
of Polymer Chemistry, Inc., 21, 4-5
(1981) and others. For example, it can be produced by a dealcoholization reaction between a trimethylol compound represented by the following formula [3] and a trialkyl orthoacylate represented by the following formula [4].

【formula】

[Formula] (However, R ¹ and R ² represent atoms or organic groups as described above, and R' represents an alkyl group.) This reaction is shown as follows. The above bicycloorthoester can also be produced by another method, that is, a direct esterification reaction of a trimethylol compound represented by the above formula [3] and a monocarboxylic acid represented by the following formula [5]. (Here, R ² represents the same atom or organic group as shown in formula [4].) The molar ratio of the trimethylol compound and the monocarboxylic acid to be charged is equal to or slightly in excess of the molar equivalent of the latter. It is preferable to do so. This reaction is expressed as follows. This reaction is generally carried out in the presence of an acidic catalyst such as P-toluenesulfonic acid, phosphoric acid, benzenesulfonic acid, etc. in an amount of 0.05 to 3% by weight of the starting reaction solution or reactants. The first stage reaction can be carried out in the presence or absence of a solvent. Examples of solvents include aromatic hydrocarbons such as benzene, toluene, and xylene; di-n-propyl ether, diamyl ether, methyl butyl ether,
Various ethers such as m-dioxane and P-dioxane; alkyl ketones such as normal or various isomers of dibutyl ketone and diamyl ketone; various ketones such as methylbenzyl ketone; linear such as n-heptane, pentane, octane, etc. Alternatively, branched hydrocarbons and the like are used. After the reaction is complete, the solvent, if used, is removed from the reaction solution, and the reactants are then slowly distilled under reduced pressure. Since bicycloorthoester is produced from the monoester during distillation, the internal temperature and degree of vacuum are adjusted during the distillation to appropriate the bicycloorthoester production rate and distillation rate. The bicycloorthoester thus separated is purified by repeated distillation, extraction with an appropriate solvent, or recrystallization, if necessary. Bicycloorthoesters in which R ¹ is a residue of a compound having a carbamoyloxymethyl group in the general formula [2], and bicycloorthoesters in which R ³ in the general formula [2'] is represented by the general formula [] , which are comprehensively represented by the following general formula, are produced by a method of reacting a polyvalent isocyanate compound and a hydroxyalkyl group-containing bicycloorthoester. (However, Q is an isocyanate or urethane compound residue, R ⁵ is the same as R ² or R ⁴ described above, and n is an integer of 1 or more.) Next, in the general formula [2'] above, Bicycloorthoesters in which R ³ is represented by the general formula [ ] are
It is produced by a method of reacting a polyepoxy compound having two or more epoxy groups in one molecule with a bicycloorthoester having a hydroxyalkyl group. Furthermore, the bicycloorthoester represented by the general formula [2″] or [2] can be produced by radical polymerization of a bicycloorthoester having a radically polymerizable unsaturated group or with another ethylenically unsaturated compound, or Through a polymer reaction in which a polymer having a functional group is reacted with a bicycloorthoester having a functional group that is reactive with the functional group,
Manufactured. For example, a bicycloorthoester represented by the following formula is added to a homopolymer of styrene having a chloromethyl group or a copolymer of such styrene and another ethylenically unsaturated compound using a sodium dechlorination reaction, which is the usual method for the reaction. Bicycloorthoester of the general formula [2''] is produced by polymeric reaction according to the method. Furthermore, the bicycloorthoester represented by the general formula [2] can be produced by polymerizing the bicycloorthoester represented by the following formula or another ethylenically unsaturated compound using a general radical polymerization method. Ru. In the bicycloorthoesters represented by the general formulas [2''] and [2], specific examples of ethylenically unsaturated compounds that can constitute the unit A include vinyl acetate, acrylonitrile, methyl methacrylate, chloromethylstyrene, Examples include styrene, etc. alone or in combination.Although x and y, which are the molar fractions of units A and B, can be arbitrary values, from the viewpoint of the physical properties and price of the polymer, y/( x+y) ratio is preferably in the range of 3/100 to 50/100.On the other hand, to explain in more detail the method for producing the bicycloorthoester having a urethane bond represented by the general formula [6], the following (1) Alternatively, there is method (2). (1) Urethane-forming reaction between an organic isocyanate and a bicycloorthoester represented by the following formula [7]. (2) Urethane formation reaction of the following compounds A), B) and C). A At least one polyisocyanate compound having at least two isocyanate groups
seed. B At least one type of polyhydroxy compound having at least two hydroxyl groups. C At least one bicycloorthoester represented by formula [7]. Examples of organic isocyanates for producing the compound represented by formula [6] include organic monoisocyanates such as methyl isocyanate, ethyl isocyanate, n-propylisocyanate, n-butyl isocyanate, hexyl isocyanate, chloroethyl isocyanate, Aliphatic monoisocyanates such as chlorpropyl isocyanate, chlorhexyl isocyanate, chlorbutoxypropyl isocyanate, octadecyl isocyanate, phenyl isocyanate, O-, m-, and P-chlorophenyl isocyanate, benzyl isocyanate, naphthyl isocyanate, O-, ethyl There are aromatic monoisocyanates such as phenyl isocyanate and dichlorophenyl isocyanate. Examples of polyisocyanate compounds having two or more isocyanate groups in the molecule include aliphatic, alicyclic and aromatic polyisocyanates, such as tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 2,4- and 2-, 6-Tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, m- and p-xylylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, m
- and p-phenylene diisocyanate, naphthalene, -1,5-diisocyanate, diphenylene-4,4'-diisocyanate, cyclohexyl-1,4-diisocyanate, isophorone diisocyanate, 4,4'-diisocyanate diphenyl ether, triphenylmethane -4,4′,
Examples include 4″-triisocyanate, 2,4,6-triisocyanate toluene, polymethylene polyphenyl isocyanate, and products obtained by reacting water and hexamethylene diisocyanate at a molar ratio of 1:3. Mixtures of polyisocyanate compounds can also be used. Other raw materials, polyhydroxy compounds with two or more hydroxyl groups, include polyhydric alcohols, polyester polyols, polyether polyols, and polymer polyols. Polyhydric alcohols include fatty acids. Polyhydric alcohols having an ether bond in the molecule, which has a structure in which one or more of these polyhydric alcohols are dehydrated and condensed, are used.For example, ethylene glycol, Propylene glycol, (1,3-, 1,4- or 2,3
-) Butanediol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, neopentyl glycol, bisphenol A, hydrogenated bisphenol A, cyclohexane-1,4-dimethanol, m- and p
-Xylidene glycol, dibromoneopentyl glycol, cyclohexane-1,4-diol, chloropropylene glycol, 2-ethylhexanediol (-1,3 or -1,6) diethylene glycol, triethylene glycol, dipropylene glycol, bisphenol Examples include A dioxyethyl ether, bisphenol A dioxypropyl ether, glycerin, trimethylolpropane, trimethylolethane, trimethylolmethane, pentaerythritol, sorbitol, and erythritol. Examples of polyester polyols include various lactones such as β-propiolactone and its substituted products, δ-valerolactone and its substituted products, and ε-
Caprolactone and its substituted products, 4-membered ring, 6-membered ring, 7-membered ring or more lactone in the presence of a catalyst or in the absence of a catalyst, ethylene glycol,
There are polyester polyols produced by ring-opening polymerization in the presence of 1,2-propylene glycol and the like, and polyester polyols produced by reacting at least two components, namely a polyhydric carboxylic acid and a polyhydric alcohol. They are produced from the polyhydric alcohols mentioned above and the polyhydric carboxylic acids mentioned below. For example, polyhydric carboxylic acids include phthalic acid, iso (or tere) phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, hymic acid, endo acid, tetrachlorophthalic acid, tetrabromophthalic acid, hettic acid, methylhexahydrophthalic acid, Acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid,
Maleic acid, fumaric acid, itaconic acid, ethylmalonic acid, 1,4-cyclohexenedicarboxylic acid,
Examples include α-methylitaconic acid, 2-methylsuccinic acid, pimelic acid, suberic acid, azelaic acid, halogenated tetrahydrophthalic acid, trimellitic acid, methylcyclohexentricarboxylic acid, aconitic acid, and pyromellitic acid. Furthermore, anhydrides, acyl halides, lower alkyl esters, etc. of each of the above-mentioned polycarboxylic acids can also be used by reacting in the same manner as the polycarboxylic acids. Examples of polyether polyols include:
Polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyalkylene oxides such as ethylene oxide-propylene oxide copolymers, alkylene oxide adducts of bisphenols, alkylene oxide adducts of hydrogenated bisphenols, and halogenated bisphenols. alkylene oxide adduct,
Examples include polyepichlorohydrin. Polymer polyols include, for example, polybutadiene with hydroxyl groups, butadiene-styrene copolymers with hydroxyl groups, acrylic ester-
Hydroxyalkyl acrylate copolymers, polybutadiene/alkylene oxide adducts with hydroxyl groups, alkylstyrene/polyether polyol reactants, acrylonitrile-polyether polyol reactants, epoxy resins-aliphatic or alicyclic alcohol reactants, etc. can give. Next, an example of a method for producing a bicycloorthoester having a urethane group by subjecting the compounds A), B), and C) of the above (2) to a urethanization reaction will be illustrated. A typical method is a two-step reaction method, in which, in the first step, a partially urethanized product having an isocyanate group at the terminal and/or side chain is produced by a urethanization reaction between a polyisocyanate compound and a polyhydroxy compound. The amount of the polyhydroxy compound used at this time is at least about 1.1 equivalents of isocyanate groups in the polyisocyanate compound per 1 equivalent of hydroxyl groups contained in the polyhydroxy compound. By varying this equivalent ratio, the molecular weight of the final product composition can be controlled. When the isocyanate group is used in a ratio lower than about 1.1 equivalents per equivalent of hydroxyl group, the molecular weight of the final composition may become significantly large, resulting in increased viscosity or insufficient curability. Furthermore, when the equivalent ratio of isocyanate groups to hydroxyl groups increases, the final product composition becomes a compound represented by the chemical formula [8] (hereinafter referred to as compound [8]) in which the isocyanate groups of the polyisocyanate compound are urethanized with compound [7]. The proportion increases. A(-NH-COO-X) _f [8] Here, X is

In the group represented by the formula, R represents a lower alkyl group, A represents a polyisocyanate residue, and f represents an integer corresponding to the valence of the polyisocyanate compound. Compound [8] has two or more bicycloorthoester groups, and since it is a polyfunctional polymerizable compound, it increases the degree of cross-linking when curing the final product composition. Helpful. In the urethanization reaction, a polyhydroxy compound is added in portions to the polyisocyanate compound as necessary to avoid a rapid temperature rise due to heat generation.
Alternatively, the reaction proceeds while controlling the temperature by dropping. Next, in the second step, compound [1] is reacted and bonded to the terminal and/or side chain isocyanate groups of the partially urethanized product obtained in the first step. Note that some partially urethanized products of this type are commercially available, and such commercial products can also be used in the present invention. The ratio of adding compound [7] to this partially urethanized product is generally such that the number of equivalents of residual isocyanate groups in the partially urethanized product is equal to the number of equivalents of hydroxyl groups in compound [7]. Depending on the purpose, the proportion of compound [7] can be increased to an equivalent number or more. In the urethanization reaction, the compound [7] is added to the partially urethanized product in order to avoid a rapid temperature rise due to heat generation.
The reaction is allowed to proceed while controlling the temperature by adding or dropping in portions or dropwise. The product produced by the above production method is a mixture of various compounds. For example, for the sake of simplicity, a diisocyanate compound is used as the polyisocyanate compound, and a dihydroxyl compound is used as the polyhydroxy compound, and the reaction is performed so that the number of equivalents of the hydroxyl group and the isocyanate group in the reaction system are equal. It is estimated that the substance is a mixture of the following compounds. X-OOC-NH-A'-NH-COO-X

[9] Here, X is the same group as explained in the above chemical formula [8], A' is the residue of the diisocyanate compound,
B represents a residue of a dihydroxy compound, and n represents an integer of 1 or more. As mentioned above, when the number of molar equivalents of isocyanate groups to hydroxyl groups is increased in the process of producing the first partially urethanized product, the chemical formula

The proportion of the compound represented by [9] increases. On the other hand, as the number of molar equivalents decreases, the proportion of the compound represented by the chemical formula [10] increases, and the molecular weight tends to increase. In addition to the compound represented by the above chemical formula, this production method will also contain a small amount of a compound containing a urea bond resulting from the reaction of an isocyanate group with water. The phenolic resin, organic polybasic acid, organic polybasic acid anhydride, and carboxylic acid type polyester used as a curing agent, which are other components of the composition of the present invention, are those used as a curing agent for epoxy compounds. can be used. First, phenolic resins are resins that have phenolic hydroxyl groups, such as polyvinylphenol, halogenated polyvinylphenol, and
Common phenolic resins, such as phenol, ortho (or para) cresol, para ethylphenol, para-tert-butylphenol, para-sec-butylphenol, para-n-butylphenol, ortho (or para) phenyl Novolak type resins, resol type resins, and modified products thereof such as butylated products, which are produced using phenol, para-cyclohexylphenol, para-octylphenol, para-benzylphenol, bisphenol A, etc., as raw materials can also be used. Next, examples of organic polybasic acids and organic polybasic acid anhydrides include succinic acid, methylsuccinic acid, dodecenylsuccinic acid, dichlorosuccinic acid, azelaic acid, sebacic acid, itaconic acid, maleic acid, citraconic acid, phthalic acid, and tetrahydrophthalic acid. ,
Methyltetrahydrophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic 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 acid anhydrides thereof. Also, mixtures of two or more of these, mixtures of these with monobasic acid anhydrides, or molecules obtained from the above polybasic acids or their acid anhydrides, such as linoleic acid adducts of maleic anhydride. Derivatives thereof having a carboxylic acid or its acid anhydride structure at the terminal or side chain can also be used. Next, as the carboxylic acid type polyester, for example, a trivalent or higher polybasic acid anhydride, an acid anhydride consisting of this and a dibasic acid anhydride, a trivalent or higher polyol, or a polyol consisting of this and a diol. There are polyesters obtained by reacting, and more specifically, for example, polyols with a valence of 3 or more, or polyols consisting of this and a diol, and polybasic acid anhydrides with a valence of 3 or more, or polybasic acid anhydrides with this and a dibasic acid anhydride. There are carboxylic acid type polyesters obtained by reacting acid anhydrides at a ratio of 0.7 to 1.3 moles of acid anhydride per equivalent of hydroxyl group in the polyol. Here, as trivalent or higher polybasic acid anhydrides,
Examples include trimellitic anhydride, pyromellitic anhydride, hemimellitic anhydride, merophanic anhydride, etc., and examples of trivalent or higher polyols include trimethylolpropane, pentaerythritol,
Examples include glycerin, diglycerin, sorbitol, mannitol, 1,2,6-hexanetriol, tris(β-hydroxyethyl)isocyanurate, and the like. Typical examples of dibasic acid anhydrides used in combination with these trivalent or higher polybasic acid anhydrides or polyols are phthalic anhydride, etc., and diethylene glycol is a typical example of diols.
Various acid anhydrides and polyols used in the technical field related to carboxylic acid type polyesters can be used. An example of the reaction between the bicycloorthoester compound and the curing agent in the present invention is as follows. An example of a reaction using phenolic resin as a curing agent. (In the above formula, Ph represents a phenolic resin residue.) An example of a reaction using an organic polybasic acid anhydride as a curing agent. (In the above formula, R ₂ represents an organic polybasic acid anhydride residue.) A reaction example using a carboxylic acid type polyester as a curing agent. (In the above formula, R ₃ represents a carboxylic acid type polyester residue.) The optimum ratio of the curing agent to be blended into the composition of the present invention is determined by the chemical properties of the curing agent used and the prepared curing composition. It may be set as appropriate depending on the properties required for the cured product provided by the cured product. per equivalent of bicycloorthoester group in the composition,
Carboxyl group or acid anhydride group is preferred
Organic polybasic acid anhydride in an amount of 0.1 to 1.5 equivalents, more preferably 0.2 to 1.3 equivalents, or phenolic hydroxyl or carboxyl groups, preferably 0.2
It is desirable to blend the phenolic resin or carboxylic acid type polyester in an amount of ~10 equivalents, more preferably 0.3 to 5 equivalents. The curing agent that is sparingly soluble or insoluble in the composition is suitably blended in the form of fine powder. If desired, suitable curing accelerators can be used to further shorten the curing time of the compositions of the invention. Suitable curing accelerators include tertiary amines, quaternary ammonium salts, coordination compounds of Lewis acids and compounds having atoms such as oxygen, sulfur, and nitrogen, such as boron trifluoride/piperidine complexes, imidazole compounds, Examples include pyridine, P-toluenesulfonic acid morpholine salt, chelate compounds, and metallocenes. The amount of curing accelerator is generally from 0.1 to 3 parts by weight per 100 parts by weight of bicycloorthoester and curing agent. There are no particular restrictions on the curing temperature, but curing is usually carried out at room temperature to 250°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. Examples of the flexibility imparting agent include polysulfide, polyamide, polyalkylene polyol, and elastomer. The composition of the present invention contains a bicycloorthoester and is characterized by very small volumetric shrinkage when cured by utilizing the ring-opening reaction of the bicycloorthoester group contained therein. For example, 2.4-tolylene diisocyanate, 1-
A novolac-type urethane bicycloorthoester (bicycloorthoester [B] described later) produced from ethyl-4-hydroxymethyl-2,6,7-trioxabicyclo[2,2,2]octane and polyneopentyl adipate The volume shrinkage rate when phenolic resin is blended as a curing agent and cured is only 0.5%, and the volume when dodecenyl succinic anhydride is blended and cured with bicycloorthoester [B] as a curing agent. The shrinkage rate is only 0.8%. Here, the volume shrinkage rate (%) is expressed as [1-(specific gravity of composition before curing/specific gravity of cured product)]×100. As mentioned above, the volumetric shrinkage of the composition of the present invention during curing is extremely small compared to general thermosetting resins. As a result, the composition of the present invention has good dimensional accuracy when used as a molding material, and when used as a casting material, there is little distortion due to shrinkage of the filling material, and it has good adhesion to the mold without forming gaps. It has its features. The composition of the present invention can form a cured product with very small internal strain due to its small shrinkage during curing, so when used as a paint, it can be applied with excellent adhesion to the coated plate with little warpage, and it has good adhesion. When used as an agent, it provides great adhesive strength. Thus, the composition of the present invention has excellent suitability as a curable material used in casting materials, molding materials, composite materials, adhesives, coatings, and other various fields. The present invention will be described in detail with reference to Examples below. In each Example, the phenolic resin and carboxylic acid type polyester as a curing agent were added and mixed in the form of fine powder to the composition. Further, the bicycloorthoesters [A], [B] and [C] used in each example and the carboxylic acid type polyester as a curing agent were produced as in the following reference examples. Reference Example 1 Production of bicycloorthoester [A]; In a 4-necked 200 ml flask equipped with a stirrer, condenser, nitrogen inlet, and dropping funnel, 22.2 g (0.1 mol) of isophorone diisocyanate, dehydrated toluene, and dibutyl as a catalyst were placed. 0.01 g of tin dilaurate was added. This mixture was heated to 70°C in an oil bath and heated to 1-ethyl-4-hydroxymethyl-2,
A solution of 34.8 g (0.2 mol) of 6,7-trioxabicyclo[2,2,2]octane mixed in 50 ml of toluene was added dropwise over about 30 minutes. The reaction was continued at this temperature for an additional 3 hours. The reaction solution was desolvented to obtain a white solid urethane bicycloorthoester containing the compound represented by the following formula as a main component.
The specific gravity of the product was measured by heating the sample above its melting point, melting and degassing, and then putting it into a density gradient tube method B type direct reading specific gravity measuring device (Shibayama Scientific Instruments Manufacturing Co., Ltd.) (Measurement method B). However, Q represents the following group. The physical properties of the above compound are as follows. Γ Softening point; 88-91℃ Γ Specific gravity (25℃); 1.200 (Measurement method B) Γ Infrared absorption spectrum (KBr tablet) 3330, 1720, 1530, 1225cm ^-1 (urethane) Γ Nuclear magnetic resonance spectrum (CDC ₃₎ Medium) δ (ppm); 0.6-1.5 (19H, -CH ₃ , -CH ₂ of the cyclohexane ring) 1.5-1.9 (6H, C-CH ₂ -C, -CH ₂ of the cyclohexane ring), 2.8-3.0 (2H , N-CH ₂ ), 3.5-4.1 (17H, N-CH, COO-CH ₂ , O
-CH ₂ ), 4.6-5.1 (2H, N-H) Reference Example 2 Production of bicycloorthoester [B]; In a flask similar to Reference Example 1, 17.4 g (0.1 mol) of 2,4-tolylene diisocyanate and dibutyltin were added. 0.01 g of dilaurate was added. This flask was heated to 70° C. in an oil bath, and 40 g (0.05 mol) of polyneopentyl adipate (average molecular weight 800) having a hydroxyl group at the end was added dropwise over about 30 minutes in a nitrogen stream. Stir further at this temperature for 2 and a half hours, then 1-
Ethyl-4-hydroxymethyl-2,6,7-trioxabicyclo[2,2,2]octane 17.4g
(0.1 mol) was added dropwise over about 30 minutes, and the reaction was continued for an additional 3 hours to obtain a semi-solid product at room temperature. The viscosity of the product at 70°C was 480,000 centipoise. Reference Example 3 Production of bicycloorthoester [C]; To the same apparatus as in Reference Example 1, 12.7 g (0.08 mol) of hexamethylene diisocyanate and 0.01 g of dibutyltin dilaurate were added. This mixture was heated to 70°C in an oil bath, and in a nitrogen stream, a propylene oxide adduct of bisphenol A (average molecular weight
900) 36.0 g (0.04 mol) was added over 30 minutes. After stirring for another 2 hours, 1-ethyl-4-
Hydroxymethyl-2,6,7-trioxabicyclo[2,2,2]octane 13.9g (0.08mol)
was added dropwise over about 30 minutes, and the reaction was continued for an additional 3 hours to obtain a viscous product. The viscosity of this reaction product was 73,000 centipoise at 50°C, and the specific gravity (25°C) was 1.107. Reference Example 4 Bicycloorthoester [D] In a device similar to Reference Example 1, 19.0 g of Epicote 828 (trade name manufactured by Ciel Chemical Co., Ltd.) (0.10 equivalent of epoxy group) and 4-hydroxymethyl-2,6,7-trio were added. Kisabicyclo[2,2,2]octane 17.4g
(0.10 mol), 0.18 g of dimethylaniline and 0.18 g of tetra-n-butylammonium bromide were added. This mixture was heated to 100°C in an oil bath, stirred for 7 hours, and further stirred at 110°C for 7 hours to react. This reaction product is a pale yellow transparent solid at room temperature.
The specific gravity at 25°C was 1.22 and the refractive index was 1.55. Further, infrared absorption spectrum (IR) analysis showed that no ester peak at 1730 cm ^-1 was observed, confirming that no ring opening occurred in the bicycloorthoester group. Reference Example 5 Production of carboxylic acid type polyester [A]; 518 g (2.7 mol) of trimellitic anhydride and 44 g of phthalic anhydride were placed in a reactor equipped with a stirrer and a reflux condenser.
g (0.3 mol) and 134 g of trimethylolpropane
(1.0 mol) and reacted at 180℃ for 20 minutes,
A polyester that is solid at room temperature was obtained. The acid value of this polyester was approximately 7.5 [meq/g]. Example 1 1-ethyl-4-hydroxymethyl-2,6,
7-trioxabicyclo[2,2,2]octane
100 parts (parts by weight, same hereinafter), 153 parts of dodecenyl succinic anhydride as a curing agent and 2,4,6-tris(dimethylaminomethyl) as a curing accelerator.
Add 2 parts of phenol and heat at 120°C for 2 hours.
The mixture was then heated at 150° C. for 2 hours to polymerize and obtain a soft polymer. The volume shrinkage rate due to polymerization determined from the specific gravity of the composition before polymerization and the specific gravity of the polymerized product at 25℃ is small.
It was 0.6%. Example 2 100 parts of 1,4-diethyl-2,6,7-trioxabicyclo[2,2,2]octane, 86 parts of a maleic anhydride adduct of methylcyclopentadiene as a curing agent, and N-cyanoethyl as a curing accelerator. 2 parts of -2-methylimidazole was added and polymerized in the same manner as in Example 1 to obtain a soft polymer. The volume shrinkage rate due to this polymerization was only 1.1%. Example 3 100 parts of 1,4-dimethyl-2,6,7-trioxabicyclo[2,2,2]octane and poly-p-vinylphenol "Resin-M" as a curing agent
70 parts (trade name, manufactured by Maruzen Oil Co., Ltd.) and 0.9 parts of boron trifluoride/piperidine complex as a curing accelerator were added, and the mixture was heated and polymerized in the same manner as in Example 1 to obtain a soft polymer. The volume shrinkage rate due to this polymerization was approximately 0. Example 4 1-ethyl-4-hydroxymethyl-2,6,
7-trioxabicyclo[2,2,2]octane
To 100 parts, add 135 parts of brominated poly-p-vinylphenol "Resin-MB" (trade name, manufactured by Maruzen Sekiyu Co., Ltd.) as a curing agent and 1.2 parts of boron trifluoride/piperidine complex as a curing accelerator. The mixture was heated and polymerized in the same manner as in Example 1 to obtain a soft polymer. The volume shrinkage rate due to this polymerization was 0.3%. Example 5 Poly-p-vinylphenol "resin" was added to 100 parts of bicycloorthoester [A] as a curing agent.
42 parts of "M" [trade name manufactured by Maruzen Oil Co., Ltd.] and 0.7 parts of boron trifluoride/piperidine complex as a curing accelerator were added, and the mixture was heated at 150°C for 1 hour and then at 180°C for 1 hour to cure the polymer. Obtained. The Shore hardness of this polymer was D-70. Further, the volume shrinkage rate due to curing was 0. Example 6 25 parts of dodecenyl succinic anhydride as a curing agent and 0.6 parts of N-cyanoethyl-2-methylimidazole as a curing accelerator were added to 100 parts of bicycloorthoester [B], and heated in the same manner as in Example 5 to form a polymer. I got it. The Shore hardness of this polymer was D-57. The volumetric shrinkage rate due to curing was 0.8%. Example 7 To 100 parts of bicycloorthoester [B], 10 parts of phenolic resin "CKM-2103" (trade name, manufactured by Showa Union Gosei Co., Ltd.) as a curing agent and 1 part of dimethylbenzylamine as a curing accelerator were added. A polymer was obtained by heating in the same manner as in 5. The Shore hardness of this polymer was D-65. The volume shrinkage rate due to curing was 0.5%. Example 8 A composition having the composition shown below was used as an adhesive to bond iron, and the tensile shear adhesive strength was measured. Adhesion was performed by applying the composition and curing it at 120°C for 2 hours and then at 150°C for 2 hours, and the tensile shear strength was measured according to the method of JIS K 6850-1977. The iron of the test piece was surface-treated by sandblasting using alumina #100.

【table】

[Table] Example 9 The compositions shown in the table below were prepared by blending the above-mentioned "Resin-M" as a curing agent and the boron trifluoride/piperidine complex as a curing accelerator with bicycloorthoester [B]. The polymer was cured by heating in the same manner as in Example 5, and the Shore hardness and volume shrinkage rate due to curing of the obtained polymer were measured. The results were as shown in the table below.

[Table] * The blending equivalent ratio is indicated by the number of equivalents of hydroxyl groups of the phenolic resin in the composition to the number of equivalents of bicycloorthoester groups in the composition.
Example 10 42 parts of hexahydrophthalic anhydride as a curing agent and 1 part of N-cyanoethyl-2-methylimidazole as a curing accelerator were added to 100 parts of bicycloorthoester [D], and the mixture was heated at 150°C for 3 hours to form a polymer. I got it. This polymer was a hard pale yellow transparent solid with a Shore hardness of D-79. The volume shrinkage rate due to this polymerization was approximately 1.0%.

Claims (1)

[Scope of Claims] 1. At least one bicycloorthoester compound having at least one bicycloorthoester group represented by the following formula [1] in one molecule;
A curing composition comprising at least one curing agent selected from the group consisting of a phenolic resin, an organic polybasic acid, an organic polybasic acid anhydride, and a carboxylic acid type polyester.