JPH0466256B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Purpose of the invention [Field of industrial application] The present invention provides a resin composition that can be used in all fields where thermosetting resins are used, such as casting, filling, painting, adhesion, and molding. It is something that provides something. [Prior art] Thermosetting resins include epoxy resins, unsaturated polyester resins, diallyl phthalate resins,
Phenol resins and the like are used, but they suffer from large volumetric shrinkage during curing, which poses a problem. On the other hand, spiro-orthoester compounds, spiro-orthocarbonate compounds, and bicyclo-orthoester compounds are known as resins that exhibit almost no volumetric contraction or, on the contrary, volumetric expansion during curing (for example, JP-A-57-4274, There is a problem that curing is slow compared to epoxy resins (Japanese Patent Application Laid-open No. 58-109534, Japanese Patent Application Laid-open No. 59-49228, etc.), and although some proposals have been made for methods of accelerating curing, none of them are satisfactory. Effective curing accelerators are not yet known. For example, JP-A-57-
No. 67628, JP-A-57-42724 and JP-A-59-
According to No. 49228, several curing accelerators have been proposed, but even when these are added, curing is very slow compared to curing of general-purpose epoxy resins. [Problems to be Solved by the Invention] The present invention uses a spiro-orthoester or a bicyclo-orthoester compound, which is known as a resin with almost no volume shrinkage during curing, and an organic polybasic acid or an organic polybasic acid as a curing agent. The aim is to shorten the curing time of a composition made of a basic acid anhydride and to cure it at a low temperature. (2) Structure of the Invention [Means for Solving Problems] The present invention provides a composition comprising a spiro-orthoester or a bicyclo-orthoester compound and an organic polybasic acid or an organic polybasic acid anhydride. This problem was solved by incorporating a curing accelerator that has an effective accelerating function for copolymerization curing. The curing accelerator to be blended in the present invention is
As mentioned above, curing accelerators are broadly classified into imidazole type curing accelerators and Lewis acid type curing accelerators, and one or more types of curing accelerators selected from these are combined with a compound having a spiro-orthoester group or a bicycloorthoester group. and an organic polybasic acid or its anhydride, preferably 0.05% to 10% by weight, more preferably 0.1% to 5% by weight.
A significant promoting effect can be obtained by adding the amount such that . The optimum amount of curing accelerator to be added varies somewhat depending on the group to which it belongs, and when adding one or more accelerators selected only from the group consisting of imidazole curing accelerators, it is 0.5% by weight based on the resin content. ~
By adding 5% by weight, it is possible to significantly shorten the curing time and lower the curing temperature compared to the case without the addition. In addition, when adding one or more accelerators selected only from the group consisting of Lewis acid curing accelerators, 0.05% of the resin content is added.
A similar effect can be obtained by adding 1% to 1% by weight, and when using at least one accelerator selected from both groups, the total amount of accelerators should be A similar effect can be obtained by adding 0.1 to 1% by weight. Further, in this case, the ratio of the accelerator selected from both groups may be arbitrary, but particularly preferably, the ratio of the luic acid curing accelerator to 1 mol of the imidaizole curing accelerator is 0.5 to 1 mol. In this case, this promoting effect is particularly remarkable. The composition of the present invention can be prepared by adding a predetermined amount of one or more selected curing accelerators to a resin component, melting the mixture at a temperature equal to or higher than its melting point or softening point, and uniformly dissolving or dispersing the mixture. . If necessary, a liquid substance prepared by dissolving or dispersing a predetermined amount of the selected curing accelerator in a low-viscosity liquid such as various additives and curing agents at room temperature may be mixed with the resin component. , prepared by homogeneous dissolution or decomposition. Further, as additives, general organic solvents such as propylene carbonate, acetone, methyl ethyl ketone, and dioxane can be used, and low melting point polymers such as polyethylene glycol, polypropylene, and glycol can also be used. In addition, as another method for preparing the composition of the present invention, either the compound having a spiro-orthoester group or a bicyclo-orthoester group to be used, or the organic polybasic acid or its anhydride as a curing agent, There is also a method of mixing a predetermined amount of a curing accelerator and using it, and it is also possible to obtain the same accelerating effect by this method. The curing accelerator is a spiro ortho ester compound or a bicyclo ortho ester compound that is liquid with low viscosity at room temperature, such as 2-methyl-1,4,6-trioxaspiro[4.6]undecane obtained from propylene oxide and ε-caprolactone, butylglycidyl. 2-(n-butyloxymethyl)-1,4,6- obtained from ether and ε-caprolactone
Trioxaspiro[4.6]undecane, or 1,4 obtained by the dealcoholization reaction of trimethylolpropane and trialkylorthoacylate.
-diethyl-2,6,7-trioxabicyclo[2,2,2]octane, etc., and a method of preparing the composition of the invention using this is also advantageous. Compounds having a spiroorthoester group used in the present invention include epoxy compounds and lactones,
Examples include spiroorthoester compounds produced by reacting γ-butyrolactone, δ-valerolactone, and ε-caprolactone, and derivatives thereof. An example of a reaction formula for synthesizing a spiro-orthoester compound is as follows. Specific examples of spiro-orthoester compounds that can be used in the present invention include spiro-orthoester compounds produced by reacting lactones with the following epoxy compounds (1) to (7). (1) [2,2-bis(4'-hydroxyphenyl)
Propane (commonly known as bisphenol A), halogenated bisphenol A, bis(4-hydroxyphenyl)methane (commonly known as bisphenol F): Novolac-type polyester condensed from resorcinol, tetrahydroxyphenylmethane, phenol or cresol and formalin. A phenolic compound such as functional phenol; phenol, cresol, t-butylphenol] and epichlorohydrin or β-methylepichlorohydrin [hereinafter both will be referred to as (β-methyl)epichlorohydrin. ] and β-methylglycidyl ether (both hereinafter referred to as (β-methyl)glycidyl ether). ] and polyglycidyl ether or poly(β-methylglycidyl)ether (hereinafter both referred to as poly))β-methyl)glycidyl)
Expressed as ether. 〕etc. (2) Butyl alcohol, allyl alcohol, ethylene glycol, polyethylene glycol,
(β-methyl)glycidyl ether or polypropylene obtained by reacting an alcohol such as 2,2-bis(4′-hydroxycyclohexyl)propane, glycerin, or 1,1,1-trimethylolpropane with (β-methyl)epichlorohydrin. ((β-methyl)glycidyl)ether, etc. (3) 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, tetrahydrophthalic acid, etc. (β- methyl)glycidyl ester and poly((β-methyl)glycidyl)ester, etc. (4) Epoxidized olefin, epoxidized polybutadiene, epoxidized vegetable oil, cyclopentadienated epoxy, etc. (5) Nitrogen-containing epoxy such as aniline-modified epoxy, nitrogen-containing heterocyclic epoxy obtained from isocyanuric acid epoxy, hydantoin derivatives, imidazoline derivatives, etc. (6) Styrene oxide etc. obtained from monounsaturated compounds, or internal epoxy type compounds synthesized by oxidizing intramolecular double bonds, manufactured by Chitsuso Co., Ltd. under the 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. (7) Epihalohydrins such as epichlorohydrin, alkylene oxides such as propylene oxide, α-butylene oxide, etc.; Examples of spiro-orthoester compounds derived from the above-mentioned spiro-orthoester compounds include compounds represented by the following formula. However, in the formula, M ¹ represents a vinyl monomer unit such as acrylonitrile, methyl methacrylate, etc. 58
-40311, JP-A-1983-49724, JP-A-58-
189521 and Japanese Patent Application Publication No. 59-33320). These are examples of spiro-orthoester compounds and are not intended to limit the scope thereof. The compound having a bicycloorthoester group used in the present invention is, for example, a compound represented by the following general formula. However, the meanings of the symbols in the above general formula are as follows. m ₁ is an integer greater than or equal to 2. R ¹ and R ² are hydrogen atoms; alkyl groups, such as linear or branched alkyl groups ranging from methyl groups with 1 carbon number to octadecyl groups with 18 carbon atoms; cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, etc. groups; 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, etc. alkaryl groups such as; hydroxyalkyl groups such as hydroxymethyl; unsaturated substituted oxyalkyl groups such as acryloyloxymethyl, methacryloyloxymethyl and vinylbenzyloxymethyl; or such as N-ethylcarbamoyloxymethyl and N-ethylcarbamoyloxymethyl;
- residues of urethane compounds having a carbamoyloxymethyl group, such as phenylcarbamoyloxymethyl; or linear or branched, for example from vinyl, α-methylvinyl, β-methylvinyl, α-ethylvinyl and propenyl to octadecenyl; alkenyl group. R ³ is an organic group represented by the following general formula [a] or [b]. Y ₁ [ _{-NHCOOCH 2 ] - n3} ... _[ A _] A group obtained by removing at least m ₃ isocyanates from a urethane compound which is a reactant and has a plurality of isocyanate groups. X ₁ is a group obtained by removing at least m ₃ epoxy groups from a polyepoxy compound. R ⁴ is a hydrogen atom; an alkyl group, an aralkyl group, or an aryl group as exemplified above for R ⁴ . M ² and M ³ are the same or different polymeric units selected from ethylenically unsaturated compounds. χ and y are the mole fractions of polymer constitutional units M ² and M ³ . (JP-A-56-108793, JP-A-56-108792, JP-A-Showa
56-167688, JP-A-57-21417, JP-A-57-
55911, JP-A-57-105412, JP-A-57-159788,
JP-A-58-61109, JP-A-58-109534, JP-A-58
-134113, JP-A-58-213780, JP-A-59-213781
(Refer to each publication) These are examples of bicycloorthoester compounds, and are not intended to limit the scope thereof. The organic polybasic acids and organic polybasic acid anhydrides to be blended as a curing agent in the composition of the present invention can be used singly or in combination of two or more thereof. Next, the curing agent will be explained in more detail. The organic polybasic acid or its acid anhydride includes any one commonly used as a curing agent for epoxy compounds, such as the following. Succinic anhydride, methylsuccinic anhydride, dodecenylsuccinic anhydride, dichlorosuccinic anhydride, azelaic anhydride, zebacic anhydride, itaconic anhydride,
Maleic anhydride, citraconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride,
Methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, tricarballylic anhydride, trimellitic anhydride, pyromellitic anhydride, and polybasic acids derived therefrom, or two thereof In addition to mixtures of the above, there are also mixtures of these with monobasic acid anhydrides, linoleic acid adducts of maleic anhydride, and compounds with structures in which these acid anhydrides are added to the hydroxyl groups of phenolic resins. Similarly, derivatives thereof having a carboxylic acid or its acid anhydride structure at the terminal or fast chain of the molecule obtained from the above acid anhydrides can also be used. Also tartaric acid, malic acid, tartronic acid, alkyltartronic acid, α-methylmalic acid, β-methylmalic acid, α-oxyglutaric acid, β-oxyglutaric acid, dicrotaric acid, α-oxysperic acid, α-oxysebacin. Acids, oxypolycarboxylic acids such as citric acid, isocitric acid, etc. can also be used. The optimum ratio of curing agent compounding can be set as appropriate depending on the chemical properties of the resin used and the properties required of the prepared curable composition and the cured product provided by it. Although the accelerating effect of the curing accelerator proposed in the invention is not particularly affected, the desirable blending ratio is the spiro-orthoester group and/or
Alternatively, the total amount of acid anhydride groups and/or carboxylic acid groups is 0.2 to 10 equivalents, more preferably 0.3 to 5 equivalents, per 1 total equivalent of bicycloorthoester groups. In the present invention, the accelerating effect of the curing accelerator is not limited by the curing temperature, and at room temperature to 250°C, which is a normal resin curing temperature,
The curing time can be shortened and the curing temperature can be lower than the conditions normally used. The composition of the present invention also includes additives that are added to the epoxy resin composition for casting, such as quartz powder,
Fillers such as alumina and β-eucryptite, dyes, retardants, etc. may be added as necessary. [Examples, Comparative Examples] Example 1, Comparative Example 1 By the production method described in the reference example of JP-A No. 58-49724, a diglycidyl ether type epoxy of bisphenol A and ε-caprolactone were produced. 45 parts of methylhexahydrophthalic anhydride was added as a curing agent to 100 parts (parts by weight, same hereinafter) of the produced spiroorthoester [A], and 0.5 to 2 parts of various curing accelerators were added to prepare a composition. Prepared. The gelation time when the resulting composition was reacted at 120°C is shown in the table below. In addition, as a comparative example, a case in which no accelerator was added, and JP-A No. 57-67628 and JP-A No. 57-67628 and
Similar tests were conducted using 2 parts of 1-cyanoethyl-2-methylimidazole as an accelerator as described in the Examples of Publication No. 42724, and the results shown in the table below were obtained. Note that the gelation time refers to the time taken for the composition to lose its fluidity after the composition is placed in a test tube and heated to a predetermined temperature.

【table】

【table】

[Table] Among the above examples, imidazole or 1-
The compositions were cured at a curing temperature of 120° C. for 1 hour, with and without the addition of 2 parts of cyanoethyl-2-methylimidazole.
Curing was carried out by heating for 2 hours and 3 hours to obtain respective cured products. The shore hardness of these cured products was measured and an acetone immersion test was conducted. The results were as shown in the table below. The acetone immersion test was conducted by immersing a sample in acetone at room temperature for 24 hours, and then measuring the dissolution rate and swelling rate using the following formula. Dissolution rate (wt%) = Dissolved weight / original sample weight x 100 Swelling rate (wt%) = ((swollen weight) / (original sample weight) -
(Weight of dissolved content) - 1) x 100

[Table] Example 2, Comparative Example 2 1,4-diethyl-2,6,7 obtained by the general production method described in JP-A-59-49228
-trioxabicyclo[2,2,2]octane 47
and the organic polybasic anhydride “Recaresin”.
A curing composition was prepared by adding 53 parts of "TMEG" [manufactured by Shin Nihon Rika Co., Ltd., trade name]. The gelation time of the composition when one part of the accelerator shown in the table below was added to this composition and reacted at 130°C is shown below. In addition, as a comparative example, the case where 1 part of 2,4,6-tris(dimethylaminomethyl)phenol was added and the case where no accelerator was added as described in the example of JP-A No. 58-109534. , conducted a similar experiment.

[Table] Example 3, Comparative Example 3 10 parts of zinc bromide and 2 parts of carbonyldiimidazole were mixed and dispersed in 100 parts of propylene carbonate to form a slurry-like curing accelerator mixture (hereinafter referred to as accelerator A). As described in JP-A-57-67628, it is obtained from Chitsonox 221 (trade name manufactured by Chitso Co., Ltd.), which is an alicyclic epoxy resin, and ε-caprolactone (JP-A-57-67628). , 100 parts of a spiro-orthoester compound [B] whose main component is represented by the following structure, as a curing agent,
Add 45 parts of methylhexahydrophthalic anhydride, add 2 parts of the above accelerator A, dissolve uniformly, and cure at 150°C for 1 hour. The resulting cured product has a Shore hardness of D-85. (Example 3). On the other hand, when one part of the boron trifluoride biperidine complex described as an example in JP-A No. 57-42724 is added instead of the accelerator [A] and cured,
In order to obtain a cured product having comparable shore hardness, curing conditions of 1 hour at 180°C or 3 hours at 150°C were required (Comparative Example 3). Spiroorthoester compound [B] Example 4, Comparative Example 4 10 parts of zinc chloride and 2-(n-butyloxymethyl)
-1,4,6-trioxaspiro[4.6]undecane (90 parts) was mixed to prepare a promoter dispersion (hereinafter referred to as promoter B). 2-(n-butyloxymethyl)-1,4,6-
Add 69 parts of methylhexahydrophthalic anhydride to 100 parts of trioxaspiro[4.6]undecane and add imidazole, promoter A or promoter B to this composition.
One part of either was added. The composition prepared in this manner was reacted on an oil bath at 80°C and 120°C, and the infrared absorption spectrum showed absorption of spiro-orthoester group (960 cm ^-1 ) and absorption of acid anhydride group (186 cm ^-1 ). The time required for the absorption intensity to become 1/2, that is, the time required for the reaction rate of each group to become 50%, was determined according to the following formula. In addition, as a comparative example, the same test was conducted in the case where no accelerator was added and in the case where 1 part of dimethylbenzylamine described in JP-A-57-42724 was added as an accelerator instead of accelerator B. I went. The results were as shown in the table below.

[Table] Reaction rate (%) (1-at/ao)×100 ao=(logI′o/I′/logIo/I) _p at=(logIo/I
'/logIo/I) _t (t: time) Io: Reference peak corrected incident light intensity (2970cm ^-1 ) I: Transmitted light intensity I'o: Corrected incident intensity of spiro-orthoester group or acid anhydride group I ': Transmitted light intensity of spiro-orthoester group or acid anhydride group Example 5, Comparative Example 5 60 parts of the spiro-orthoester compound [A] used in Example 1 was added with BES-P- which is a polyhydric carboxylic acid.
Add 40 parts of 210 [trade name manufactured by Toagosei Kagaku Kogyo Co., Ltd.] and melt it uniformly, and add 1 part each of promoter A, promoter B or imidazole used in Examples 3 and 4 to this composition. Prepare the compositions and make them
The gelation time of the composition when reacted at 100°C is shown below. Further, as a comparative example, the results of a similar test with the addition of 1 part of 2,4,6-tris(dimethylaminomethyl)phenol described in the Examples of JP-A-58-109534 are also shown below.

[Table] (C) Effects of the Invention The resin composition of the present invention has superior curing performance compared to conventional resin compositions because it contains a characteristic curing accelerator, and the curing temperature can be lowered. Even at lower temperatures, the time required for curing can be reduced.

Claims (1)

[Scope of Claims] 1. At least one compound having at least one spiro-orthoester group or bicyclo-orthoester group in the molecule, at least one curing agent selected from the group consisting of organic polybasic acids and their anhydrides. and the following imidazole curing accelerator (A)
A thermosetting resin composition comprising at least one curing accelerator selected from each or both of and Lewis acid curing accelerator (B). Imidazole curing accelerator (A); imidazole, carbonyldiimidazole, 2
-Phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenylimidazole, 2-phenyl-4-cyanoethoxymethyl-5-ethoxymethylimidazole, 2-methyl Imidazole isocyanuric acid adduct, 1-cyanoethyl-2-methylimidazole trimellitic acid adduct, 2,4-diamino-6-(2'-ethyl-
4'-Methylimidazolyl-1')ethyl-S-triazine or 2-phenylimidazoline. Lewis acid curing accelerator (B); zinc fluoride, zinc chloride, zinc bromide, zinc iodide, guanidine tetrafluoride borate or zinc boron tetrafluoride.