DE69328554T2 - DIGUANAMINE, PRODUCTION, DERIVATIVES AND APPLICATION - Google Patents

Description

Technical area

The present invention relates to novel diguanamines useful as polymerizable monomers, as resin starting materials for paint resins, adhesive resins, paper coating resins, fiber treatment resins, powder coating resins and building materials, as raw materials for guanamine compound derivatives, as curing agents for epoxy resins and urethane resins, and as modifiers for high molecular substances such as rubber materials. The present invention also relates to a process for producing the diguanamines and their derivatives useful as curing agents and intermediates for various resins, and also to the use of the diguanamines and their derivatives.

State of the art

As resin raw materials for paint resins, adhesive resins, paper coating resins, fiber treatment resins and coating treatments, curing agents for various resins, modifiers for rubber materials, modifiers for organic materials, and the like, guanamines containing an aminotriazine group such as melamine and benzoguanamine have been widely used so far because of their excellent properties including high hardness and high gloss, colorless clarity, high chemical resistance and water resistance, and their excellent abrasion resistance and electrical properties and, in the case of curing agents, because of the excellent durability of the resulting resins.

Furthermore, extensive research and development work has been carried out on melamines and guanamines containing an aminotriazine group, which has led to the provision of even polyfunctional guanamines containing a tetrafunctional group or an even higher functional group and which are superior in terms of flexibility, toughness, hardness, Water resistance, curability and the like of the resins show excellent characteristic properties.

Such polyfunctional guanamines differ fundamentally in their structure from the new diguanamines according to the invention, so that a comparison between the two is extremely difficult. However, the examples given for comparison purposes include phthaloguanamines which are

and spiroguanamines, which are represented by

are shown.

However, the first compound has the disadvantages that the resins using them as a raw material are very poor in their resistance to ultraviolet light and in their weather resistance and therefore they cannot be used at all as resin raw materials for exterior paints, weather-resistant paints, automobile paints and construction resins, or they are considerably limited in such applications, and that they are considerably limited in their use as raw materials for water-based paint resins because the water solubility of amino resins formed from phthaloguanamines as their derivatives is still insufficient in practice although it has been somewhat improved over conventional melamine-based amino resins. On the other hand, the second compound also has the disadvantages that resins obtained by using this compound as a raw material have poor heat resistance and poor weather resistance, ultraviolet light resistance and water resistance, and they are difficult to maintain their expected functions in outdoor environments for a long period of time as resins for exterior paints, water-resistant paints, automobile paints and building materials. Furthermore, because of the low activity of the amino groups in the second compound, which is characterized by a low reaction rate of the second compound to form a methylol derivative, the second compound has a problem that the production of various useful guanamine derivatives, resins and resin curing agents obtainable by reactions of the amino groups and also the production of formaldehyde co-condensation polymers between the second compound and compounds such as melamine and benzoguanamine are considerably limited. Moreover, a reaction mixture obtainable by forming a methylol derivative of the second compound is difficult to obtain as a clear solution, resulting in another disadvantage that when it is used as a raw material for water-based resins such as water-based paint resins, adhesive resins, paper coating resins and fiber treatment resins, sufficient properties in terms of smoothness, curability and physical properties of the resulting coating films are difficult to obtain, and the reaction mixture cannot be used for such applications or is considerably limited for such applications. The second compound has another disadvantage that the production of spironitrile as a starting material for the production of the second compound not only poses technical problems such as the need for many complex steps including a laborious purification step but also involves considerable economic impairment. As described above, these compounds are considerably limited technically and economically in terms of their use and production.

In addition to the guanamine compounds represented by the above formulas, other compounds containing diaminotriazinyl groups have been disclosed in the prior art. US-A-3 408 254 describes 2,2'-(1,2-cyclo butylene)bis[4,6-diamino-s-triazine] as useful for the preparation of resin compositions. US-A-2 532 519 relates to complex aryldiguanamines consisting of diaminotriazinyl radicals linked through a divalent aromatic radical. EP-A-0 391 665 relates to amino compounds consisting of substituted diaminotriazinyl radicals linked through a -(CH₂)₄ group. EP-A-0 422 402 discloses N,N,N',N'-tetraalkoxymethylcyclohexanecarboguanamines. US-A-2 901 464 relates to compounds having triazinyl radicals linked through a -CR₁R₂-ORO-CR₃R₄ group, wherein R₁, R₂, R₃ are and R4 are hydrogen or lower alkyl and R is alkylene, alkylidene or alkylidenediphenyl.

Disclosure of the invention

In view of the above drawbacks, the present inventors have made extensive studies. As a result, diguanamines which are completely different in structure and characteristic properties from the multifunctional diguanamines described above for comparison purposes have been found. These diguanamines contain active amino groups which show excellent reactivity toward compounds having various functional groups. Due to the incorporation of eight active hydrogen atoms, the degree of methylol derivatization and the like can be selected from a wide range. They are excellent in weather resistance, resistance to ultraviolet light and the like, so that they retain their expected functions in outdoor or similar conditions for a long period of time. Further, their methylol derivatives are excellent in properties such as water solubility, curability, water resistance, anti-staining property, flexibility, hardness and toughness. An excellent process for producing such diguanamines has also been found. According to these processes, any desired diguanamine compound can be obtained in high purity with the production of an extremely small amount of by-products and in high yield from a corresponding dicarbonitrile, which is obtained at low cost ly, and the process requires simple manufacturing steps such as a simple purification and isolation step. These findings have led to the present invention.

As derivatives obtainable from such useful diguanamines, the present inventors have also prepared N-methylol derivatives by reacting the diguanamines with aldehydes, etherified diguanamines by etherifying N-methylol derivatives with alcohols, and their initial condensates. The present inventors have also found curing agents for various resins, thermosetting compositions containing these derivatives useful as raw materials for resins such as resin varnishes, and thermosetting resin compositions containing the diguanamines and epoxy-containing resins useful as varnish resins, powder coating resins, and adhesive resins, leading to the present invention.

The diguanamines described above are extremely useful compounds and can provide polymers, compounds and compositions excellent as rubber modifiers, optical materials, resist materials, electrical insulating materials, automobile paints, paints for electric and electronic devices, antifouling paints, weather-resistant paints, fluorescent paints, resinous building materials, powder coatings, water-based paints, oil-based paints, paper coating resins, fiber treatment resins, adhesive resins, IC packaging resins, anticorrosive resins, polymer modifiers, coating treatments, plastic magnets, latex antioxidants, electrophotographic photoconductors, surfactants, agricultural chemicals, medicines, etc.

The present invention therefore provides:

(a) a diguanamine represented by the following formula (1),

wherein the binding sites for the 4,6-diamino-1,3,5-triazin-2-yl groups are the 2,5- or 2,6-positions, or is represented by the following formula (2),

wherein the binding sites for the 4,6-diamino-1,3,5-triazin-2-yl groups are the 1,2-, 1,3- or 1,4-positions;

(b) a process for producing a diguanamine which comprises reacting a dicarbonitrile represented by the following formula (3),

where the binding sites for the cyano groups are the 2,5- or 2,6-positions,

or by the following formula (4)

is shown, in which the binding sites for the cyano groups are the 1,2-, 1,3- or 1,4-positions,

with dicyandiamide in the presence of a basic catalyst ;

(c) a process for preparing a diguanamine as described in (b) above, wherein the basic catalyst lysator is at least one compound selected from the group consisting of alkali metals, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alcoholates, alkali metal salts of dicyandiamide, alkaline earth metal salts of dicyandiamide, amines and ammonia;

(d) a process for producing a diguanamine as described in (b) above, wherein the reaction is carried out using at least one solvent selected from the group consisting of non-aqueous protic solvents and aprotic polar solvents as a reaction solvent;

(e) a process for producing a diguanamine as described in (b) above, wherein the reaction is carried out in a temperature range of 60°C to 200°C;

(f) an N-methyloldiguanamine obtained by an addition reaction of the diguanamine described in (a) above and an aldehyde;

(g) an etherified diguanamine obtained by etherification reaction of the N-methyloldiguanamine derivative described in (f) above and at least one alcohol selected from alcohols having 1-20 carbon atoms, the etherified diguanamine containing at least one R₁OCH₂ group, where R₁ represents the residue of a group formed by removing a hydroxy group from the alcohol;

(h) a primary condensate of N-methyloldiguanamine obtained by addition condensation of the diguanamine described in (a) above, a condensable compound as an optional reactant and an aldehyde and having an average addition condensation degree of higher than 1 and at least one methylol group;

(i) Primary condensate of an etherified diguanamine obtained by addition reaction or addition condensation of the diguanamine described in (a) above, a condensable compound as an optional reactant and an aldehyde and then obtained by etherification and optionally simultaneous condensation of the reaction product and at least one alcohol selected from alcohols having 1-20 carbon atoms and having an average degree of addition condensation higher than 1 and at least one R₁OCH₂ group, wherein R₁ is as defined above;

(j) a thermosetting composition containing as an essential component at least one compound selected from N-methyloldiguanamines described above under (f), the etherified diguanamines described above under (g), the primary condensates of the N-methyloldiguanamines described above under (h), and the primary condensates of the etherified diguanamines described above under (i);

(k) a thermosetting composition as described in (j) above, additionally comprising a resin curable by reaction with the component described in (j) above;

(l) a paint resin composition comprising the thermosetting composition described in (k) above;

(m) a thermosetting resin composition comprising the diguanamine described in (a) above and an epoxy-containing resin;

(n) a paint resin composition comprising the thermosetting resin composition described in (m) above;

(o) a paint resin composition as described in (n) above, wherein the composition is a powder coating resin composition; and

(p) an adhesive resin composition comprising the thermosetting resin composition described in (m) above.

Short description of the drawings

Fig. 1 is an IR absorption spectrum of a compound obtained in Example 1;

Fig. 2 is a mass spectrum of the compound obtained in Example 1;

Fig. 3 is an IR absorption spectrum of a compound obtained in Example 3; and

Fig. 4 is a mass spectrum of the compound obtained in Example 3.

Best mode for carrying out the invention

In the diguanamine (1) of the present invention, the binding sites for the 4,6-diamino-1,3,5-triazin-2-yl groups are the 2,5- or 2,6-positions. The configuration of such groups is endo-endo, endo-exo or exo-exo. All of these stereoisomers are useful compounds.

Although the diguanamine (1) is a compound selected from the group consisting of the isomers described above in terms of binding sites or configuration, mixtures of various compounds selected from such a group are also extremely useful from an industrial point of view as the individual compounds.

Specific examples of the diguanamine (1) include, but are not limited to, 2,5-bis(4,6-diamino-1,3,5-triazin-2-yl)bicyclo[2.2.1]heptane (endo-exo form), 2,5-bis(4,6-diamino-1,3,5-triazin-2-yl)bicyclo[2.2.1]heptane (exo-exo form), 2,6-bis(4,6-diamino-1,3,5-triazin-2-yl)bicyclo[2.2.1]heptane (endo-endo form), and 2,6-bis(4,6-diamino-1,3,5-triazin-2-yl)bicyclo[2.2.1]heptane (exo-exo form).

In the diguanamine (2) according to the invention, the binding sites for the 4,6-diamino-1,3,5-triazin-2-yl groups are the 1,2-, 1,3- or 1,4-positions. The configuration of such groups is either trans or cis. All of these stereoisomers are useful compounds.

Although the diguanamine (2) is a compound selected from the group consisting of the above-described isomers with respect to the binding sites or configuration, mixtures of the various compounds selected from such a group are also extremely useful from an industrial point of view as the individual compounds.

Specific examples of the diguanamine (2) include, but are not limited to, 1,2-bis(4,6-diamino-1,3,5- triazin-2-yl)cyclohexane (cis form), 1,2-bis(4,6-diamino-1,3,5- triazin-2-yl)cyclohexane (trans form), 1,3-bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane (trans form), 1,3-bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane (cis form), 1,4-bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane (trans form) and 1,4-Bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane (cis form).

Each diguanamine of the present invention can be obtained, for example, by a process in which a dicarbonitrile represented by the following formula (3),

wherein the bonding sites of the cyano groups are the 2,5- or 2,6-positions, or by the following formula (4),

is shown, in which the binding sites for the cyano groups are the 1,2-, 1,3- or 1,4-positions,

with dicyandiamide in the presence of a basic catalyst, or by a process in which an ester of a dicarboxylic acid corresponding to dicarbonitrile and a biguanide are reacted optionally in the presence of a basic compound. The latter process is excellent both technically and economically, and is extremely practical because the raw materials are readily available and easy to handle, by-products are minimized, and the desired compound can be obtained in high purity, the preparation including the purification step is simple, the loss of raw materials is very small, and the desired compound can be obtained in high yield. It should be noted, however, that the production process of the diguanamine is not necessarily limited to these processes.

In the dicarbonitrile (3) in the process for producing the diguanamine, which process belongs to this invention, the bonding sites for the cyano groups are the 2,5- or 2,6-positions. The configuration of these groups is endo-endo, endo-exo or exo-exo. All of these stereoisomers are useful. Although the dicarbonitrile (3) is a compound selected from the group consisting of the above isomers with respect to the bonding sites or the configuration, mixtures of the various compounds selected from such a group are also useful as the individual compounds.

The dicarbonitrile (3) can be obtained, for example, by a process in which bicyclo[2.2.1]hepta-5-ene-2-carbonitrile and a hydrogen cyanide are reacted in the presence of a certain catalyst such as Co₂(CO)₈, Fe(CO)₅. or Ni[P(OC₆H₅)₃]₉ as described in U.S. Patent No. 2,666,748, or the like, by a process in which 5- (and/or 6-) cyanobicyclo[2.2.1]hepta-2-carbaldehyde and a hydroxylamine are reacted as disclosed in U.S. Patent No. 3,143,570 or the like, or by a process in which 2,5- (and/or 2,6-) dichlorobicyclo[2.2.1]heptane and a cyanating agent are reacted, such as an alkali metal cyanate or alkaline earth metals tall cyanate. It should be noted, however, that the manufacturing process is not limited to such processes.

Specific examples of dicarbonitrile (3) include, but are not limited to, bicyclo[2.2.1]heptane-2,5- dicarbonitrile (endo-exo form), bicyclo[2.2.1]heptane-2,5- dicarbonitrile (endo-endo form), bicyclo[1.2.1]heptane-2,6- dicarbonitrile (endo-exo form), and bicyclo[2.2.1]heptane-2,5- dicarbonitrile (exo-exo form).

In the dicarbonitrile (4) in the production process for diguanamine, the process pertaining to the present invention, the bonding sites for the cyano groups are the 1,2-, 1,3- or 1,4-positions. The configuration of these groups is either trans or cis. All of these stereoisomers are useful compounds. Although the dicarbonitrile (4) is a compound selected from the group consisting of the above-described isomers with respect to the bonding sites or configuration, mixtures of the various compounds selected from such a group are also useful as the individual compounds.

The dicarbonitrile (4) can be prepared, for example, by a method in which 4-cyanocyclohexene and hydrogen cyanide are reacted in the presence of a catalyst such as Ni[P(OC₆H₅)₃]₄ as disclosed in U.S. Patent No. 3,496,217 or the like, by a method in which 3- (and/or 4-)cyanocyclohexanecarbaldehyde and a hydroxylamine are reacted as disclosed, by a method in which a dihalogenated cyclohexane corresponding to the dicarbonitrile (4) and a cyanating agent are reacted such as an alkali metal cyanate or alkaline earth metal cyanate, by a method in which a dicarboxylic acid corresponding to the dicarbonitrile (4) or the dianmonium salt, diamide or diester derivative of the dicarboxylic acid and ammonia are reacted using a dehydrating agent such as an alumina catalyst or Thionyl chloride, or by a process in which 1-cyanocyclohexene and hydrogen cyanide are reacted in the presence of a base, such as sodium hydroxide. It should be noted, however, that the manufacturing process is not limited to such processes.

Specific examples of the dicarbonitrile (4) include, but are not limited to, 1,2-cyclohexanedicarbonitrile (trans form), 1,3-cyclohexanedicarbonitrile (trans form), 1,3-cyclohexanedicarbonitrile (cis form), 1,4-cyclohexanedicarbonitrile (trans form), and 1,4-cyclohexanedicarbonitrile (cis form).

In the process for producing the diguanamine of the present invention, the molar ratio of the dicarbonitrile to dicyandiamide to be reacted with each other can be appropriately selected as required. The molar ratio of the dicarbonitrile to dicyandiamide to be reacted with each other is stoichiometrically 1:2. The use of dicyandiamide in an unduly small molar ratio relative to the dicarbonitrile is not preferable because the yield of the diguanamine of the present invention becomes low and, moreover, the corresponding monoguanamine [1:1 (molar ratio) reaction product of dicarbonitrile and dicyandiamide] is increasingly formed and the purification step and the like thus become cumbersome. The use of dicyandiamide in an unduly large molar ratio makes the removal, separation and the like of the unreacted dicyandiamide, etc. cumbersome. The use of dicyandiamide at such an unduly small or large molar ratio is therefore not preferred from both technical and economic points of view. In view of improving the yield of the diguanamine of the invention and also simplifying the process, including the purification step, it is generally desirable to react 1.5-10.0 moles, preferably 2.0-5.0 moles, of dicyandiamide with 1 mole of dicarbonitrile.

Examples of the basic catalyst in the process for producing the diguanamine according to the invention include alkali metals such as potassium or sodium; alkali metal and alkaline earth metal hydroxides such as lithium, potassium, sodium, calcium and barium hydroxide; alkali metal and alkaline earth metal carbonates such as potassium, sodium and barium carbonate; alkali metal alcoholates such as Potassium ethylate, sodium methylate and sodium ethylate; alkali metal and alkaline earth metal salts of dicyandiamide; amines such as 1,8-diazabicyclo[5.4.0]undecen-7, triethylenediamine, piperidine, ethylenediamine, diethylenetriamine, pyrrolidone and tetrahydroquinoline; and ammonia. Particularly preferred are alkali metals, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alcoholates, alkali metal salts of dicyandiamide, alkaline earth metal salts of dicyandiamide, amines and ammonia. They may be used either singly or in combination. Although there is no particular limitation on the amount of such a catalyst, it may be used in an amount of 500-0.001 mol%, preferably 300-0.1 mol%, based on dicarbonitrile, in view of the production conditions and economy. The amount of the catalyst can be appropriately selected as required.

In the above process for producing the diguanamine, it is extremely convenient to carry out the process using one of various solvents as a reaction solvent in order to make the reaction proceed more smoothly. However, it is not preferable to use any solvent which may induce the formation of a compound other than the desired compound or may cause inhibition of the reaction, for example, a solvent such as a fatty acid, a fatty acid anhydride, trifluoroacetic acid, liquid sulfur dioxide, sulfuryl chloride, a mineral acid or water.

Illustrative examples of reaction solvents include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, iso-butanol, tert-butanol, 2-ethylhexanol, dodecyl alcohol, allyl alcohol, propargyl alcohol, benzyl alcohol, cyclohexanol, ethylene glycol, butanediol, glycerin, 1,2,6-hexanetriol, 2-methoxyethanol, 2-ethoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, furfuryl alcohol, tetrahydrofurfuryl alcohol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, Diacetone alcohol, 2,2,2-trifluoroethanol and 1,3-dichloro-2-propanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and acetophenone; esters such as ethyl acetate, butyl acetate and benzyl acetate; ethers such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, dioxane, crown ether and anisole; carboxylic acid amides such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and 1,3-dimethyl-2-imidazolidinone; sulfolanes such as sulfolane, methylsulfolane and 1,3-propanesulfolane; sulfoxides such as dimethyl sulfoxide; Amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, isopropylamine, butylamine, 2-ethylhexylamine, allylamine, aniline, cyclohexylamine, pyridine, piperidine, monoethanolamine, 2-(dimethylamino)ethanol, diethanolamine, triethanolamine, isopropanolamine and triisopropanolamine; and ammonia. Particularly preferred are nonaqueous protic solvents such as alcohols, amines and ammonia, and aprotic polar solvents such as carboxylic acid amides, sulfolanes and sulfoxides. These solvents can be used either singly or as a mixed system consisting of two or more of these solvents, such as mixed solvents such as ammonia-alcohol and dimethyl sulfoxide-Cellosolve. They can be suitably selected as required. Such solvents preferably have a water content as low as possible, particularly a water content of 1.0 wt% or less.

Reaction temperatures of not higher than 60°C are not preferred because the reaction is extremely slow, so that a long time is required for the preparation and the yield is very low. In general, when the reaction is carried out at a temperature of 60°C or higher, particularly at a temperature of 80°C or higher, the reaction proceeds very rapidly and uniformly, so that the desired compound can be obtained in high yield. However, when the reaction temperature exceeds 200°C, the formation of by-products suddenly increases to such an extent that these by-products can no longer be ignored, and the purity of the product is significantly reduced. Reaction temperatures exceeding 200°C are therefore not preferred. In the process for producing diguanamine according to the invention, it is therefore preferred to carry out the reaction in a temperature range of 60-200°C, more preferably 80-180°C. In such a temperature range, the formation of by-products is minimized, and the desired compound can be obtained in high purity, the preparation including the purification can be carried out easily, and the desired compound can be obtained in a higher yield.

Although there is no particular limitation on the reaction system, the reaction may be carried out either under normal pressure or under naturally occurring pressure or elevated pressure in a closed vessel. The reaction system may be appropriately selected as required.

In order to obtain the diguanamine of the present invention, that is, the desired compound from the reaction mixture of the above reaction, it is most preferable to cool the reaction mixture and recover the crystallized diguanamine by filtration. Alternatively, the reaction mixture may be poured into hot water as it is, and thereafter crystallization and filtration may be carried out. Unreacted dicyandiamine and/or dicarbonitrile co-existing with the crude diguanamine can be removed simply by washing the crude diguanamine with hot water or methanol. When further purification is required depending on the purpose, the diguanamine may be obtained by recrystallization in the above-described reaction solvent such as alcohol, cellosolve, carboxylic acid amide, sulfolane or sulfoxide, a mixed solvent of such a solvent and water, or water; by dissolving the diguanamine in the above-described reaction solvent and then pouring the obtained solution into hot water to cause reprecipitation; or by dissolving the crude diguanamine in an aqueous solution acidified with HCl and mixing the resulting solution with a base, where by which diguanamine is reprecipitated. However, such additional purification is not required in practice in most cases because the yield in the process for producing diguanamine according to the invention is extremely good and, moreover, the diguanamine can be obtained in high purity sufficient for practical applications by simply washing it with one of various solvents such as methanol, water, a mixed solvent thereof or the like.

The diguanamine of the present invention exhibits excellent polymerizability with various compounds such as aldehydes, epoxy compounds, carboxylic acids and isocyanates and has various excellent reactivities, so that the diguanamine is extremely useful as a raw material for resins and also as a raw material for derivatives. Moreover, diguanamine derivatives such as reaction products of diguanamine with aldehydes, reaction products obtained by etherification of the former reaction products with alcohols, and reaction products obtained by condensation of the former and the latter reaction products are practically useful as curing agents and raw materials for various resins.

Such diguanamine derivatives include, for example, the derivatives described above:

(f) N-methyloldiguanamine obtained by addition reaction of the diguanamine described in (a) and an aldehyde and represented by the following formula (5) or (6): Formula (5)

wherein the bonding sites for the N-substituted 4,6-diamino-1,3,5-triazin-2-yl groups are the 2,5- or 2,6-positions, R₂, R₃, R₄, R₅, R₆, R₇ and R₈ each represent a substituent selected from a hydrogen atom and a HOCH₂ group, and R₂, R₃, R₄, R₅, R₆, R₇ and R₅ may be the same or different, or formula (6)

wherein the binding sites for the N-substituted 4,6-diamino- 1,3,5-triazin-2-yl groups are the 1,2-, 1,3- or 1,4-positions, R₂, R₃, R₄, R₅, R₆, R₂ and R₈ have the same meaning as defined above and R₂, R₃, R₄, R₅, R₆, R₇ and R₈ may be the same or different;

(g) etherified diguanamines each obtained by etherifying the N-methyloldiguanamine described in (f) above with at least one alcohol selected from the group consisting of alcohols having 1-20 carbon atoms containing at least one R₁OCH₂ group, wherein R₁ represents the residue formed by removing a hydroxy group from the alcohol, and represented by the following formula (7) or (8): Formula (7)

wherein the attachment sites for the N-substituted 4,6-diamino-1,3,5-triazin-2-yl groups are the 2,5- or 2,6-positions, R₁ represents the residue of a group formed by removing a hydroxy group from the alcohol, R₉, R₁₀, R₁₁, R₁₇, R₁₄, R₁₃, R₁₄ and R₁₅ each represent a substituent selected from a hydrogen atom and HOCH₂ and R₁OCH₂ groups, and R₁, R₁₀, R₁₁, R₁₄, R₁₄, R₁₄, and R₁₅ may be the same or different, or formula (8)

wherein the attachment sites for the N-substituted 4,6-diamino-1,3,5-triazin-2-yl groups are the 1,2-, 1,3- or 1,4-positions, R1 represents the residue of a group formed by removing a hydroxy group from the alcohol, R9, R10, R11, R12, R13, R14 and R15 have the same meaning as described above, and R9, R10, R11, R12, R13, R14 and R15 may be the same or different;

(h) primary condensates of N-methyloldiguanamine, each of which is obtained by addition condensation reaction of the diguanamine described above under (a), a condensable compound as an optional reactant and an aldehyde and has an average degree of addition condensation of greater than 1 and contains at least one methylol group; and

(i) primary condensates of the etherified diguanamine, each of which is prepared by addition reaction or addition-condensation reaction of the diguanamine described in (a) above, a condensable compound as an optional reactant and an aldehyde and then by etherification of the reaction product with at least an alcohol selected from the group consisting of alcohols having 1-20 carbon atoms and optionally a simultaneous condensation reaction and having an average degree of addition condensation higher than 1 and at least one R₁OCH₂ group, wherein R₁ is as defined above.

Examples of aldehydes used to prepare these derivatives include, but are not limited to, formaldehyde, paraformaldehyde, hexamethylenetetramine, methylhemiformal, butylhemiformal, formaldehyde-sodium bisulfite addition product, and glyoxal. Preferred are formaldehyde, formalin, paraformaldehyde, hexamethylenetetramine, methylhemiformal, and butylhemiformal.

Useful alcohols for etherification in the preparation of these derivatives include saturated or unsaturated aliphatic alcohols having 1-20 carbon atoms, alicyclic alcohols, alcohols having one or more ether groups, and alcohols having one or more aromatic groups. Examples of such alcohols include, but are not limited to, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-alcohol, n-hexyl alcohol, sec-heptyl alcohol, 2-ethylhexyl alcohol, n-nonyl alcohol, n-hexadecyl alcohol, n-octadecyl alcohol, n-eicosyl alcohol, cyclohexyl alcohol, t-cyclohexenyl alcohol, 4-methylhexyl alcohol, 4-hexylcyclohexyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, and benzyl alcohol.

In preparing these derivatives, co-condensable compounds may be used in some of the cases described above. Examples of such co-condensable compounds include, but are not limited to, melamine, urea, alkylureas, thiourea, alkylthioureas, aniline, and guanamines such as benzoguanamine and cyclohexylcarboguanamine.

In the case of the N-methyloldiguanamine described above, the reaction proceeds very rapidly and uniformly to provide a derivative having at least one HOCH₂ group when the reaction is carried out, for example, in a solvent and, if necessary, in the presence of a basic compound at pH 8.0-13.0, preferably pH 8.5-11.5, and a reaction temperature of not lower than 30°C; preferably 40-80°C. In order to obtain an N-methyloldiguanamine having a high degree of methylol derivatization, the derivative can be obtained in high purity and in high yield when the reaction is carried out using water and alcohol in smaller amounts. However, the use of water and alcohol in appropriate amounts results in a reduction in the stirring effect, unevenness in the reaction temperature, etc., making it difficult to carry out the reaction uniformly. It is therefore not preferable to reduce the amounts of water and the alcohol. In order to carry out the reaction uniformly, it is effective to carry out the reaction in the presence of a solvent which is substantially insoluble in water and does not inhibit the reaction, such as an aromatic hydrocarbon such as toluene, xylene, ethylbenzene, cumene or benzene, an aliphatic hydrocarbon such as hexane, heptane, octane or cyclohexane, a halogenated hydrocarbon such as dichloromethane, or an aliphatic ether such as diisopropyl ether; or adding an amine as an auxiliary, such as an aliphatic amine such as hexamethylenetetramine, piperazine or piperidine, an aliphatic amine such as triethylamine, diethylamine, dibutylamine or hexylamine, an aromatic amine such as pyridine or aniline, or ammonia in an amount of 0.01-10 mol% based on the aldehyde. The reaction can be carried out by appropriately selecting these methods as required. It should be noted, however, that the practical operation of the reaction is not necessarily limited to the use of such methods.

The etherified diguanamine described above can be prepared, for example, by reacting the N-methyloldiguanamine obtained above for 1-8 hours under acidic conditions at pH 2-4 at a temperature of 40-80ºC in the presence of Al alcohol with which the etherification reaction is to be carried out. It is particularly preferred to carry out the etherification by reducing the amount of water in the reaction system as much as possible and adding the reactants in a ratio of at least 20 moles of alcohol per mole of N-methyloldiguanamine.

The primary condensate of the N-methyloldiguanamine described above can be obtained, for example, by reacting with the aldehyde at a temperature of 40-100°C under conditions of pH 8.0 or lower or pH 13.0 or higher.

Furthermore, the primary condensate of the etherified diguanamine can be obtained by, for example, etherifying or both etherifying and condensing the N-methyloldiguanamine or the primary condensate of the N-methyloldiguanamine under acidic conditions at pH 1.0-5.0 at a temperature of 50-100°C in the presence of the alcohol with which the etherification reaction is to be carried out. It should be noted, however, that the production process is not limited to those described above.

The N-methyloldiguanamine, the etherified diguanamine, the primary condensate of N-methyloldiguanamine and the primary condensate of the etherified diguanamine have excellent reactivity with compounds and resins having various kinds of functional groups and are extremely useful as curing agents for various resins and also as intermediates for resin raw materials. For example, it is possible to provide a thermosetting composition comprising at least one derivative selected from the group consisting of the derivatives (f), (g), (h) and (i). Although such compositions are useful as adhesives, anti-wrinkle finishing agents for fibers such as synthetic fibers such as polyester fibers and acrylic fibers, and natural fibers such as cotton and wool, excellent surface-improving agents for antifouling agents, paper coating agents and coating treatments, even when these derivatives are contained alone as curing components, the diguanamine inhibitors can be used as curing agents. The derivatives can further be reacted with those containing one or more hydroxy, carboxy, isocyanate and/or epoxy groups, so that resins with excellent properties can be obtained. In combination with various polymers such as acrylic resins, epoxy resins, polyester resins, urethane resins, aminoalkyd resins, phenolic resins, fluorinated resins and vinyl resins, the above derivatives can provide thermosetting compositions which are extremely useful as chain extenders, crosslinking agents, hardeners, denaturants and/or modifiers. They are accordingly useful for a wide range of applications, for example as adhesive resins, paint resins and construction resins. In particular, thermosetting compositions comprising at least one derivative selected from the group consisting of N-methyloldiguanamines, etherified diguanamines, primary condensates of N-methyloldiguanamines and primary condensates of etherified diguanamines, and a resin curable by reaction with the derivative are useful as resins for paints such as water-based paints and oil-based paints.

The resin curable by reaction with such a derivative can be any resin having functional groups that can be reacted with the derivative to cure the resin. For example, resins containing at least one type of groups selected from hydroxy groups, carboxy groups, epoxy groups, methylolamido groups, alkoxymethylamino groups, and isocyanate groups are useful. Examples of such resins include, but are not limited to, acrylic resins, epoxy resins, polyester resins, phenolic resins, phenol-alkyd resins, urethane resins, fluorinated resins, silicone resins, and modified resins thereof.

The diguanamines of the present invention can provide thermosetting resin compositions comprising, as essential components, at least one diguanamine selected from the diguanamines described above and an epoxy-containing resin. A conventional composition containing an epoxy-containing resin and an amine as a curing agent cures at relatively low temperatures, however, Because the amine used as a curing agent is chemically active, the amine will react with the epoxy-containing resin when they are stored as a mixture.

This has resulted in the disadvantage that the composition has a shorter shelf life and its handling is difficult. A composition containing dicyandiamide as a curing agent has relatively good storage stability; however, the articles obtained by curing the composition have the disadvantage that their properties such as flexibility and light resistance are not good. Therefore, there are significant limitations on the use of such compositions. In view of these disadvantages, the present inventors have made an extensive study. As a result, the above-described thermosetting resin compositions have been found which have excellent storage stability and can provide cured resin articles having excellent properties as cured products such as excellent flexibility and light resistance.

These thermosetting resin compositions are useful for a wide range of applications such as IC packaging materials, adhesives, powder coatings, oil-based paints, electrical insulating materials and the like.

Any epoxy-containing resin can be widely used in this invention as long as it contains at least one epoxy group. In general, a polyepoxide containing at least two epoxy groups per molecule is preferred. Although there are no particular restrictions on the epoxy-containing resins, illustrative examples of epoxy-containing resins include, but are not limited to, diglycidyl ether type epoxy resins of bisphenol A; butadiene epoxide; 4,4-di(1,2-epoxyethyl)diphenyl ether; 4,4'-di(epoxyethyl)biphenyl, diglycidyl ether of resorcinol; diglycidyl ether of fluoroglycine; triglycidyl ether of p-aminophenol; triglycidyl ether of m-aminophenol; tetraglycidylbis(aminophenol)methane; 1,3,5-tri(1,2- epoxyethyl)benzene; 2,2,4,4-tetraglycidoxybenzophenone; tetraglycidoxytetraphenylethane; polyglycidyl ethers of novolak phenol-formaldehyde resins; triglycidyl ethers of trimethylolpropane; triglycidyl ethers of glycerin; epoxy resins of halogenated bisphenol A of the diglycidyl ether type; polyglycidyl ethers of halogenated novolak phenol-formaldehyde resins; cycloaliphatic epoxy resins such as vinylcyclohexane dioxide and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate; heterocyclic epoxy resins such as hydantoin epoxy resin and triglycidyl isocyanurate; Polymers of epoxy-containing vinyl monomers such as glycidyl acrylate and glycidyl methacrylate with copolymerizable vinyl monomers such as acrylate esters, methacrylate esters, fumarate esters, maleate esters, acrylamides, methacrylamides, acrylonitrile, methacrylonitrile, styrenes, butadienes and vinyl esters; and modified polymers thereof.

When a high molecular weight bisphenol A diglycidyl ether type epoxy resin cannot be used in the present invention because of its high viscosity, the resin can be modified using a modifier such as a low molecular weight bisphenol A glycidyl ether type epoxy resin, bisphenol A, bisphenol S, brominated bisphenol A or brominated bisphenol S.

The mixing ratio of the diguanamine of the present invention to the epoxy-containing resin may be suitably selected depending on the use. In general, however, the diguanamine is used in an amount of 0.2-3.0 equivalents, preferably 0.4-1.5 equivalents, per equivalent of the epoxy group in the epoxy-containing resin.

For each thermosetting resin composition of the present invention, a curing accelerator such as a novolak type phenol resin, a metal salt of an organic acid or imidazole may be appropriately selected and blended. The use of such a curing accelerator is particularly preferred when a novolak type phenol resin is used, because a thermosetting resin composition having excellent storage stability and curability can be obtained.

Examples of the novolak type phenol resin include, but are not limited to, those prepared by a method known per se in the art from a phenol such as phenol, cresol, xylenol, ethylphenol, butylphenol, p-phenylphenol, nonylphenol, bisphenol A, resorcinol or chlorophenol and an aldehyde such as formaldehyde or paraformaldehyde. Although the mixing ratio of the novolak type phenol resin is generally 0.1-10 parts by weight per 100 parts by weight of the epoxy-containing resin, it can be appropriately selected as required.

The thermosetting resin compositions of the present invention can each be obtained by mechanically mixing a raw material batch composed of diguanamine, the epoxy-containing resin and, if necessary, other optional components in the prescribed mixing ratios in a Z-blade mixer, extruder, dry ball mill or the like to a sufficient degree. Furthermore, the mixture thus obtained may be subjected to melt mixing by hot rolls or the like in some cases. However, the diguanamine of the present invention has a high melting point, so that the mixture cannot flow smoothly or the cured article obtained cannot be homogeneous. Even if such melt-mixing is not preferred, a thermosetting resin composition in a fully compatible form can still be obtained, for example, by heating, melting and previously mixing the diguanamine together with a low-viscosity diluent, a solubilizer, a novolac type phenol resin, etc., by adding an epoxy-containing resin to the resulting melt and then mixing these components with heating, by dissolving and mixing the guanamine and the epoxy-containing resin in a solvent, or by removing the solvent from the mixed solution. These methods can be appropriately selected as required. Note that the present invention is not necessarily limited to any of these methods.

Besides the above-described diguanamine and epoxy-containing resin, to each thermosetting resin composition of the present invention, if necessary, there may be added an inorganic filler such as silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay, mica, red oxide, glass fiber or carbon fiber; a mold-releasing agent such as a natural wax, a synthetic wax, a metal salt of a fatty acid, an acid amide, an ester or a paraffin; a flame retardant such as chlorinated paraffin, bromotoluene, hexabromobenzene or antimony trioxide; a dye such as carbon or red oxide; a silane coupling agent; a flexibilizing agent; a viscosity-reducing diluent; one or more of various curing accelerators; etc.

Each diguanamine of the present invention can provide compounds and resins such as polyalkylene acids, polyimides and polyamides, all of which have excellent properties when reacted with carboxylic acids such as phthalic acid, adipic acid, maleic acid, trimellitic acid, ethylenetetracarboxylic acid, cyclopentanetetracarboxylic acid, pyrromellitic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 2,2',3,3'-benzophenonetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,2',3,3'-biphenyltetracarboxylic acid, 2,2-bis(3,4-dicarboxyphenyl)propane, bis(2,3-dicarboxyphenyl)methane, 2,3,6,7-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,2,3,4-benzenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid and 1,2,7,8-phenanthrenetetracarboxylic acid; or with their precursors, ie partial esters, acid anhydrides, halogen acylates and the like. Furthermore, any diguanamine of the invention can provide compounds and resins such as polyurea, all of which have excellent properties when reacted with isocyanates such as 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, diisocyanates derived from dimer acids, bis(2-isocyanatoethyl)fumarate, methylcyclohexane-2,4-diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isopropylidene-bis(4-cyclohexyl isocyanate), xylylene diisocyanate, m-phenylene diisocyanate, tolidine diisocyanate, dianisidine diisocyanate, 3,3'-dimethyl-4,4'-di phenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and the like, or with polyisocyanates obtained by reacting such isocyanates with polyols, amines, water or the like. In addition, each diguanamine of the invention can also provide resins with excellent properties when reacted with compounds containing one or more N-substituted unsaturated imido groups, for example monophenylmaleimide, monophenylcitraconimide, monophenylitaconimide, 2-chlorophenylmaleimide, 2,5-dichlorophenylmaleimide, 2-methylphenylmaleimide, 2,6-dimethylphenylmaleimide, 4-hydroxyphenylmaleimide, N,N'-ethylenebismaleimide, N,N'-hexamethylenebismaleimide, N,N'-dodecanemethylenebismaleimide, N,N'-m-phenylenebismaleimide, N,N'-p-phenylenebismaleimide, N,N'-p-phenylenebiscitraconimide, N,N'-p-phenylenebisitaconimide, N,N'-p-phenylene-endomethylenetetrahydrophthalimide, N,N'-4,4'-diphenylmethanebismaleimide, 2,2-bis-[4-(4-maleimidophenoxy)phenyl]propane, N,N'-4,4'-dicyclohexylmethanebismaleimide, N,N'-m-xylenebismaleimide, N,N'-diphenylcyclohexanebismaleimide, 4,4'-bismaleimidocinnamic anilide, 4,4'-methylenebis(2-isopropyl-6-methylphenylmaleimide) and 2,2-bis[4-(4-maleimidophenoxy)phenyl]hexafluoropropane. Furthermore, each diguanamine of the present invention can also be used as a chain extender, crosslinking agent, curing agent, high molecular modifier and the like having excellent properties for various polymers such as urethane resins and epoxy resins. However, it is noted that the use of each diguanamine is not limited to these.

As described above, the diguanamines of the present invention have excellent reactivity and polymerizability with various compounds. Such polymerizations, reactions and the like can be carried out by any polymerization or reaction method such as solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, interfacial polymerization, solution reaction or water system reaction. A suitable polymerization or reaction method can be selected as required.

The diguanamines of the present invention have specific inherent properties such as excellent weather resistance, UV light resistance and the like and can maintain the original outdoor performance for a long period of time, their methylol derivatives have excellent water solubility and have excellent properties as raw materials for water-based resins without any substantial limitation, they contain active amino groups having excellent reactivity with aldehydes, epoxy compounds, carboxylic acids, isocyanates and the like, and allow a methylol derivatization degree to be selected from a wide range due to the incorporation of eight active hydrogen atoms. Moreover, they can provide various guanamine derivatives and resins having various excellent properties such as flexibility, toughness, high hardness, water resistance and curability and can exhibit excellent performance, so that they are extremely useful compounds.

When the specific compounds described above are used and the reaction catalyst, solvent, reaction temperature, molar ratio of raw materials and the like are appropriately selected, the process for producing diguanamine according to the present invention can obtain the desired product in high purity while minimizing by-products. The production process including the purification step is simple, can significantly reduce the loss of raw materials, can produce the desired product in high yield from the economically available raw materials, and is therefore excellent in terms of technology and economy and has extremely high practical utility.

Such diguanamines have excellent polymerizability with various compounds such as aldehydes, epoxy compounds, carboxylic acids and isocyanates, and also have various excellent reactivities. They are therefore extremely useful as raw materials for resins and derivatives. For example, they can provide derivatives that can be used as curing agents for various various resins and also extremely useful as intermediates for resin raw materials, such as N-methyloldiguanamines obtained by reacting the diguanamines with aldehydes, etherified diguanamines obtained by etherification of the N-methyloldiguanamine derivatives and alcohols, and their primary condensates; thermosetting compositions containing these derivatives; and thermosetting resin compositions containing the above diguanamines and epoxy-containing resins, the compositions being useful as IC packing material resins, paint resins and adhesive resins.

The diguanamines of the present invention are excellent compounds which are guanamine derivatives, resins and compositions which are industrially useful in an extremely wide field as rubber modifiers, optical materials, resist materials, electrical insulating materials, paints for electric and electronic devices, automobile paints, antifouling paints, anticorrosive paints, weather-resistant paints, fluorescent paints, powder coatings, water-based paints, oil-based paints, building materials, IC packaging materials, paper coating agents, fiber treatments for antifouling treatment of indoor articles such as curtains, sofas, wallpapers and carpets, and also for water-vapor barrier treatment, sweat absorption treatments, SP treatments, crease resistance treatments, water and oil repellency treatments of fibers, adhesive resins, coating treatments, plastic magnets, latex antioxidants, anticorrosive agents, electrophotographic photoconductors, surfactants, agricultural chemicals, pharmaceuticals and the like.

The present invention will hereinafter be described in detail by the following Reference Examples and Examples. However, it should be noted that this invention is in no way limited to them or by these Reference Examples and Examples.

Reference example 1 Preparation of a dicarbonitrile (3)

Into a 500 mL flask equipped with a stirrer, a thermometer, a liquid inlet tube and a condenser were charged 297.92 g (2.50 mol) of bicyclo[2.2.1]hepta-5-ene-2-carbonitrile, 8.77 g (6.75 mmol) of Ni[P(OCH5)3]4, 4.80 g (35.22 mmol) of ZnCl2 and 32.27 g (0.104 mol) of P(OC6H5)3. After the flask was completely purged with nitrogen gas, the reaction mixture was kept at 65°C under stirring. To the flask was then added 94.59 g (3.50 mol) of ice-cooled liquid hydrocyanic acid at a flow rate of 45-55 ml/hour over a period of 3 hours, and the reaction was then carried out for an additional hour.

The flask was purged again with nitrogen gas, and then deionized water was added. The resulting water layer was removed to obtain an oil in a semi-solid form. The oil was filtered off and then subjected to vacuum distillation to obtain 362.20 g of a mixture of bicyclo[2.2.1]heptane-2,5-dicarbonitrile and bicyclo[2.2.1]heptane-2,6-dicarbonitrile at 129-137°C/L mmHg (yield: 99.01%). The following are the results of elemental analysis of the desired product. Elemental analysis:

Preparation of bicyclo[2.2.1]heptane-2,5-dicarbonitrile

In a 2 l flask equipped with a stirrer, a thermometer and a reflux condenser were charged 179.0 g (1.2 mol) of 5-cyanobicyclo[2.2.1]hepta-2-carbaldehyde, 292.6 g (1.3 mol) of N,O-bis(trifluoroacetyl)hydroxylamine, 197.8 g (2.5 mol) of pyridine and 600 ml of benzene. The resulting mixture was gradually warmed and refluxed with stirring for 3 hours. Deionized water (500 ml) was then added to the reaction mixture. The water layer thus obtained was removed to obtain an oil. The oil was distilled under reduced pressure to obtain 128.0 g of bicyclo[2.2.1]heptane-2,5-dicarbonitrile at 131-136°C/L mmHg (yield: 73%). The following are the results of elemental analysis of the desired product. Elemental analysis:

Reference example 3 Preparation of a dicarbonitrile (4)

Into a 500 ml flask equipped with a stirrer, a thermometer, a gas inlet tube and a condenser were charged 188.6 g of 4-cyanocyclohexene, 6.0 g of Ni[P(OC6H5)3]4, 3.0 g of ZnCl2 and 23.9 g of P(OC6H5)3. After the flask was completely purged with nitrogen gas, the reaction mixture was kept at 75°C with stirring. Then, into the flask was charged hydrocyanic acid gas diluted with nitrogen at a concentration of 42 mol% at a rate of 177.0 mmol/hour for 7 hours. After the flask was again purged with nitrogen gas, the reaction mixture was cooled. Analysis revealed that a dicarbonitrile (4) was obtained in a yield of 64.9%.

Water and ethyl acetate, 500 g each, were added to the reaction mixture. After the resulting mixture was allowed to stand for 5 hours under stirring, the organic layer was separated. Then, ethyl acetate was evaporated, followed by vacuum distillation at 0.5-1.0 mmHg, whereby 132.0 g of a mixture of 1,3-cyclohexanedicarbonitrile and 1,4-cyclohexanedicarbonitrile were obtained as a 120-130ºC fraction. Analysis showed that the fraction consisted of 64.4% 1,3-cyclohexanedicarbonitrile and 35.6% 1,4-cyclohexanedicarbonitrile. The following are the results of elemental analysis of the desired product. Elemental analysis:

example 1 Preparation of a diguanamine (1)

In a 3-liter flask equipped with a stirrer, a thermometer and a reflux condenser, 146.2 g (1.0 mol) of dicarbonitrile (3) prepared in the same manner as in Reference Example 1, 210.2 g (2.5 mol) of dicyandiamide, 16.8 g of potassium hydroxide and 1000 ml of methyl cellosolve were charged, followed by gradual heating. The reaction mixture became transparent as the temperature increased. When the temperature reached about 105°C, the reaction proceeded rapidly with substantial heat evolution, so that the solvent was evaporated under reflux. Some time after the evaporation under reflux started, the reaction mixture became turbid. The resulting mixture was reacted at 120-125°C for 10 hours with stirring. After removing the solvent from the reaction mixture, 3 liters of deionized water was poured therein. The resulting white precipitate was collected by filtration. The resulting solid was washed with deionized water and then with methanol and then dried in vacuum. The resulting solid was dissolved in ethyl cellosolve, to which deionized water was added to carry out precipitation. The precipitate was collected by filtration. The resulting solid was washed with water and then dried in vacuum to give 2,5-bis(4,6-diamino-1,3,5- triazin-2-yl)bicyclo[2.2.1]heptane and 2,S-bis(4,6-diamino-1,3,5-triazin-2-yl)bicyclo[2.2.1]heptane were obtained as a mixture in the form of white powdery crystals having a melting point of 317-324 °C (measured by DSC). Incidentally, as a result of analyzing the reaction mixture (before treatment) by liquid chromatography, it was found that, based on the amount of dicarbonitrile (3) added, the yield (mol %) of diguanamine (1) was 98.2% and the yield of compounds other than the raw materials and the desired compound was 0.08 wt %. The results of elemental analysis and analysis of 1H-NMR spectrum of the desired compound are shown below. In addition, the results of analysis of the IR absorption spectrum and mass spectrum of the desired compound are shown in Fig. 1 and Fig. 2, respectively. Elemental analysis:

¹H-NMR spectrum (internal standard substance: TMS, solvent: d₆-DMSO)

Absorption, based on NH₂ groups, δ: 6.50 ppm (singlet), 6.72 ppm (singlet).

Example 2 Preparation of 2,5-bis(4,6-diamino-1,3,5-triazin-2-yl)-bicyclo[2.2.1]heptane

A reaction was carried out in a similar manner to Example 1 except that 146.2 g (1.0 mol) of dicarbonitrile (3) prepared in the same manner as in Reference Example 1 was replaced with 160.8 g (1.1 mol) of bicyclo[2.2.1]heptane-2,5-dicarbonitrile prepared in the same manner as in Reference Example 2, and the resulting reaction mixture was treated. The solid thus obtained was subjected to vacuum drying to obtain 2,5-bis(4,6-diamino-1,3,5-triazin-2-yl)bicyclo[2.2.1]heptane as white powdery crystals having a melting point of 318-321°C (measured by DSC). Incidentally, as a result of analyzing the reaction mixture (before the treatment) by liquid chromatography, it was found that the yield of diguanamine (1) was 96.4 mol% based on the amount of dicarbonitrile (3) used. In the IR spectrum of the desired compound, the absorption caused by the nitrile (at 2235 cm⁻¹) of the raw material compound disappeared, and instead, an absorption caused by a triazine ring was observed at 821 cm⁻¹. Its elemental analysis data were in good agreement with the calculated values shown below. Elemental analysis:

Example 3 Preparation of a diguanamine (2)

In a 3-liter flask equipped with a stirrer, a thermometer and a reflux condenser, 134.2 g (1.0 mol) of dicarbonitrile (4) prepared in the same manner as in Reference Example 3, 210.2 g (2.5 mol) of dicyandiamide, 16.8 g of potassium hydroxide and 1000 ml of methyl cellosolve were charged, followed by gradual heating. The reaction mixture became transparent as the temperature increased. When the temperature reached about 105°C, the reaction proceeded rapidly with substantial heat generation, so that the solvent was evaporated under reflux. Some time after the evaporation under reflux started, the reaction mixture became turbid. The resulting mixture was reacted at 120-125°C for 10 hours with stirring.

After removing the solvent from the reaction mixture, 3 L of deionized water was poured therein. The resulting white precipitate was collected by filtration. The resulting solid was washed with deionized water and with methanol and then dried in vacuum. The resulting solid was dissolved in ethyl cellosolve, to which deionized water was added to effect reprecipitation. The resulting precipitate was collected by filtration. The resulting solid was washed with water and then dried in vacuum to obtain 1,3-bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane and 1,4-bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane as a mixture in the form of white powdery crystals having a melting point of 317-321°C (measured by DSC). Incidentally, as a result of analysis of the reaction mixture (before treatment) by liquid chromatography, it was found that, based on the amount of dicarbonitrile (4) used, the yield of diguanamine (2) was 97.3 mol% and the yield of the compound(s) other than the raw materials and the desired compound was 0.12 wt%. The results of elemental analysis and analysis of ¹H-NMR spectrum of the desired compound are shown below. In addition, the results of analysis of IR absorption spectrum and mass spectrum of the desired compound are shown in Fig. 3 and Fig. 4, respectively. Elemental analysis:

¹H-NMR spectrum (internal standard substance: TMS, solvent: d₆-DMSO)

Absorption, based on NH₂ groups, δ: 6.49 ppm (singlet).

Example 4 Preparation of 1,4-bis(4,6-diamino-1,3,5-triazin-2- yl)cyclohexane

A reaction was carried out in a similar manner to Example 3 except that 134.2 g (1.0 mol) of the dicarbonitrile (4) prepared in the same manner as in Reference Example 3 was replaced with 147.6 g (1.1 mol) of 1,4-cyclohexanedicarbonitrile, and the resulting reaction mixture was treated. The solid thus obtained was subjected to vacuum drying to obtain 1,4-bis(4,6-dianino-1,3,5-triazin-2-yl)cyclohexane as white powdery crystals having a melting point of 319-322°C (measured by DSC). Incidentally, as a result of analysis of the reaction mixture (before treatment) by liquid chromatography, it was found that, based on the amount of the dicarbonitrile (4) used, the yield of the diguanamine (2) was 95.8 mol%. From the IR absorption spectrum of the title compound, it was found that the absorption caused by nitrile (at 2237 cm⁻¹) of the raw material compound disappeared and instead a new absorption caused by a triazine ring was observed at 821 cm⁻¹. The elemental analysis data were in good agreement with the calculated values shown below. Elemental analysis:

¹H-NMR spectrum (internal standard substance: TMS, solvent: d₆-DMSO)

Absorption, based on NH₂ groups, δ: 6.50 ppm (singlet).

Example 5 Preparation of 1,2-bis(4,6-diamino-1,3,5-triazin-2- yl)cyclohexane

A reaction was carried out in a similar manner to Example 3 except that 134.2 g (1.0 mol) of dicarbonitrile (4) prepared in the same manner as in Reference Example 3 was replaced with 134.2 g (1.0 mol) of 1,2-cyclohexanedicarbonitrile, and the resulting reaction mixture was treated. The solid thus obtained was vacuum dried to obtain 1,2-bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane as white powdery crystals. In the IR absorption spectrum of the desired compound, the absorption of the raw material compound caused by nitrile disappeared and instead, a new absorption caused by a triazine ring was observed at . The elemental analysis data were found to be in good agreement with the calculated values shown below. Elemental analysis:

Example 6 Production of diguanamines (1)

A reaction was carried out in the same manner as in Example 1 except that the amount (in moles) of dicyandiamide used and the reaction solvent were changed, the reaction was carried out, and the reaction mixture thus obtained was treated. The yields of the desired compounds, diguanamines (1), are shown in Table 1. Table 1

* Calculated based on the results of liquid chromatography of each of the reaction mixtures (before treatment)

Example 7 Production of diguanamines (1)

In a 3-liter flask equipped with a stirrer, a thermometer and a reflux condenser, 146.2 g (1.0 mol) of dicarbonitrile (3) obtained in the same manner as in Reference Example 1, 210.2 g (2.5 mol) of dicyandiamide, 54.0 g of sodium methylate and 1000 ml of dimethyl sulfoxide were charged, followed by gradual heating. When the reaction temperature reached about 105°C, the reaction proceeded rapidly with considerable heat evolution. The temperature was then gradually raised to 140°C, and then the reaction was carried out at 140-145°C for 2 hours with stirring.

The reaction mixture thus obtained was treated in a similar manner as in Example 1 to obtain 2,5-bis(4,6-diamino-1,3,5-triazin-2-yl)bicyclo[2.2.1]heptane and 2,6-bis(4,6-diamino-1,3,5-triazin-2-yl)bicyclo[2.2.1]heptane as a mixture. Incidentally, as a result of the analysis of the reaction ion mixture (before treatment) by liquid chromatography, it was found that, based on the amount of dicarbonitrile (3) used, the yield of diguanamine (1) was 99.7 mol%.

Example 8 Production of diguanamines (2)

Reactions were carried out in a similar manner to Example 3 except that the amount (in moles) of dicyandiamide used and the reaction solvent were changed, and the resulting reaction mixtures were treated. The yields of the desired compounds, diguanamines (2), are shown in Table 2. Table 2

* Calculated based on the results of liquid chromatography of each of the reaction mixtures (before treatment)

Example 9 Preparation of 1,4-bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane

In a 3-liter flask equipped with a stirrer, a thermometer and a reflux condenser, 134.2 g (1.0 mol) of 1,4-cyclohexanedicarbonitrile, 210.2 g (2.5 mol) of dicyandiamide, 54.0 g of sodium methylate and 1000 ml of dimethyl sulfoxide were charged, followed by gradual heating. The reaction mixture became transparent as the temperature increased. When the temperature reached about 105°C, the reaction proceeded rapidly with considerable heat generation. The temperature was then raised to 140°C and then the reaction was carried out at 140-145°C for 2 hours with stirring.

The reaction mixture thus obtained was treated in a similar manner as in Example 3 to obtain 1,4-bis(4,6-diamino-1,3,5-triazin-2-yl)cyclohexane as white powdery crystals. Incidentally, as a result of analyzing the reaction mixture (before treatment) by liquid chromatography, it was found that the yield of diguanamine (2) was 99.1 mol% based on the amount of dicarbonitrile (4) used.

According to the production process of the present invention, which can provide a diguanamine by reacting a specific dicarbonitrile and a dicyandiamide while appropriately selecting the reaction catalyst, solvent, reaction temperature, molar ratio of raw materials and/or the like, the desired compound can be obtained with extremely minimized amounts of by-products in high purity and in high yield as shown in Examples 1-9 above. The process including the purification step is easy to carry out and excellent.

Example 10 Preparation of an N-methylol derivative of a diguanamine (1) and the water dilution test of the derivative

To 15.7 g (0.05 mol) of diguanamine (1) obtained in the same manner as in Example 1 was added 42.2 g of 37% formalin (0.52 mol based on 100% formaldehyde) adjusted to pH 10.5 with a 10% aqueous solution of sodium hydroxide. The resulting mixture was heated at 60-65°C for 30 minutes with stirring. The reaction mixture was homogeneous and clear. As a result of its analysis, it was found that 7.2 mol of formaldehyde was bound as methylol to one mol of diguanamine (1).

To the obtained solution of the N-methylol derivative, 50 g of deionized water was gradually added at room temperature. The so-obtained solution was also homogeneous and clear.

Example 11 Preparation of an N-methylol derivative of a diguanamine (2) and the water dilution test of the derivative

To 15.1 g (0.05 mol) of the diguanamine (2) obtained in the same manner as in Example 3 was added 42.2 g of 37% formalin (0.52 mol based on 100% formaldehyde) adjusted to pH 10.5 with a 10% aqueous solution of sodium hydroxide. The resulting mixture was heated at 60-65°C for 30 minutes with stirring.

The reaction mixture was homogeneous and clear. The result of its analysis showed that 7.3 moles of formaldehyde were bound as methylol to one mole of the diguanamine (2).

To the obtained solution of the N-methylol derivative, 50 g of deionized water was gradually added at room temperature. The solution thus obtained was also homogeneous and clear.

As shown in Examples 10 and 11, it was found that the N-methylol derivative of each diguanamine of the present invention has excellent water solubility, so that it is excellent as a raw material for a resin to be used in an aqueous system, such as a water-based varnish resin, and it is extremely useful for a wide variety of applications.

Comparison example 1 Preparation of an N-methylol derivative of phthaloguanamine and water dilution test of the derivative

A reaction was carried out in a similar manner to Example 10 except that 14.8 g (0.05 mol) of o-phthaloguanamine was used in place of 15.7 g (0.05 mol) of the diguanamine (1) obtained in the same manner as Example 1.

The reaction mixture contained a large amount of insoluble solid, so it was subjected to solid-liquid separation by hot filtration. The solid was dried under reduced pressure to obtain 13.7 g of crystals, which were found to contain 13.6 g (0.046 mol) of o-phthaloguanamine as a result of elemental analysis. Then, deionized water (1.0 g) was added to the filtrate at room temperature, whereby considerable turbidity occurred.

Comparison example 2 Preparation of an N-methylol derivative of spiroguanamine and water dilution test of the derivative

A reaction was carried out in a similar manner to Example 10 except that 15.7 g (0.05 mol) of the diguanamine (1) obtained in the same manner as in Example 1 was replaced with 21.7 g (0.05 mol) of 3,9-bis[2-(3,5-diamino-2,4,6-triazaphenyl)ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane] ("CTU-guanamine"; product of Ajinomoto Co., Inc.).

The reaction mixture thus obtained contained a large amount of an insoluble solid, so that it was subjected to solid-liquid separation by hot filtration. The solid was dried under reduced pressure to obtain 18.3 g of crystals, which elemental analysis revealed to contain 18.2 g (0.042 mol) of CTU-guanamine. Then, deionized water (1.0 g) was added to the filtrate at room temperature, whereby considerable turbidity occurred.

As shown above in Comparative Examples 1 and 2, the methylol formation reaction of phthaloguanamine and spiroguanamine with aldehydes is extremely slow. The amino groups in such compounds have low reactivity, so that it is difficult to prepare resin intermediates such as cocondensates with melamine, guanamines or ureas, or various derivatives. Furthermore, N-methyloid derivatives of such compounds have extremely low water solubility. It is therefore difficult to use them as raw materials for resins to be used in aqueous systems such as water-based paint resins. Moreover, they are considerably limited in their applications.

Example 12 Preparation of an N-methylol derivative of a diguanamine (1)

To 15.7 g (0.05 mol) of diguanamine (1) obtained in the same manner as in Example 1 was added 17.9 g of 37% formalin (0.22 mol based on 100% formaldehyde) adjusted to pH 9.0 with a 5% aqueous solution of sodium carbonate. The resulting mixture was heated at 70-75°C for 3D minutes with stirring. The reaction mixture was clear. Analysis of the mixture revealed that 4.0 mol of formaldehyde was bound as methylol to one mol of diguanamine (1).

Example 13 Preparation of an N-methylol derivative of a diguanamine (1)

To 15.7 g (0.05 mol) of the diguanamine (1) obtained in the same manner as in Example 1 were added 19.9 g (0.32 mol) of methyl hemiformal and 40.0 g of methanol, and then the pH was adjusted to 9.5 with a 20% aqueous solution of potassium hydroxide. The resulting mixture was heated at 60°C for 1 hour with stirring. The reaction mixture was clear. Analysis of the mixture revealed that 6.1 mol of formaldehyde was bound as methylol to one mol of the diguanamine (1).

Example 14

Preparation of an N-methylol derivative of a diguanamine (1)

To 15.7 g (0.05 mol) of 2,5-bis(4,6-diamino-1,3,5-triazin-2-yl)-bicyclo[2.2.1]heptane obtained in the same manner as in Example 2 was added 81.2 g of 37% formalin (1.0 mol based on 100% formaldehyde) adjusted to pH 10.5 with a 5% aqueous solution of sodium hydroxide. The resulting mixture was heated at 60°C for 1 hour with stirring. The reaction mixture was clear. Analysis of the mixture revealed that 7.8 mol of formaldehyde was bound as methylol to one mol of 2,5-bis(4,6-diamino-1,3,5-triazin-2-yl)-bicyclo[2.2.1]heptane.

Example 15 Preparation of an N-methoxymethyl derivative of a diguanamine (1)

The N-methylol derivative of 5.0 g of the diguanamine (1), the derivative being a reaction mixture prepared in the same manner as in Example 10 and formed from formaldehyde and diguanamine combined in a molar ratio of 7.2:1, was dehydrated under reduced pressure, and then 50 ml of methanol was added thereto. After the pH was adjusted to 2.0 with a 20% nitric acid, the resulting mixture was heated at 40-45°C for 2 hours. The reaction mixture was adjusted to pH 8.0 with a 10% aqueous solution of sodium hydroxide. From the solution, methanol and water were removed under reduced pressure, and then the solid was filtered off to obtain a viscous liquid. Analysis of the liquid revealed that 5.3 equivalents of N-methoxymethyl groups were bound to one mole of the diguanamine (1).

Example 16 Preparation of an N-methoxymethyl derivative of a diguanamine (2)

The N-methylol derivative of 5.0 g of the diguanamine (2), the derivative being a reaction mixture prepared in the same manner as in Example 11 and formed from formaldehyde and the diguanamine combined in a molar ratio of 7.3:1, was dehydrated under reduced pressure, and then 50 ml of methanol was added thereto. After being adjusted to pH 2.0 with a 20% nitric acid, the resulting mixture was heated at 40-45°C for 2 hours. The reaction mixture was adjusted to pH 8.0 with a 10% aqueous solution of sodium hydroxide. Methanol and water were removed from the solution under reduced pressure, and the solid was filtered off to obtain a viscous liquid. Analysis of the liquid revealed that 4.9 equivalents of N-methoxymethyl groups were bound to one mole of diguanamine (2).

From Examples 15 and 16, it is apparent that the N-methylol derivative of each diguanamine, the derivative of which belongs to the present invention, easily undergoes an alkyl etherification reaction with an alcohol under mild conditions, thus has excellent reactivity and can provide N-alkoxymethylated derivatives of the N-methylol derivative, the alkoxymethylated derivatives being extremely useful as resin intermediates.

Example 17 Preparation of a primary condensate of N-methyloldiguanamine (2)

To 15.1 g (0.05 mol) of the diguanamine (2) obtained in the same manner as in Example 4 were added 13.1 g of paraformaldehyde (80% purity) (0.35 mol based on 100% formaldehyde) and 50 ml of methanol. The resulting solution was adjusted to pH 13.2 with a 20% aqueous solution of potassium hydroxide with stirring and then heated at 80 °C for 1 hour with stirring. After heating, the reaction mixture was adjusted to pH 8.0 with a 10% aqueous solution of hydrochloric acid. The resulting precipitate was filtered off to obtain a clear solution. Analysis of the resinous product obtained by solvent removal from the clear solution revealed that it was a primary condensate of N-methyloldiguanamine, the condensate being formed from the diguanamine (2) and formaldehyde, which is bound as methylol in a ratio of 6.0 moles of formaldehyde to a structural unit of the diguanamine and has an average degree of addition condensation of 1.3.

Example 18 Preparation of a primary condensate of a diguanamine (1)

To 15.7 g (0.05 mol) of the diguanamine (1) obtained in the same manner as in Example 1 were added 18.8 g of paraformaldehyde (80% purity) (0.5 mol based on 100% formaldehyde) and 50 ml of n-butanol. The solution was adjusted to pH 11.0 with a 10% aqueous solution of sodium hydroxide while stirring. The reaction mixture was heated at 60°C for 30 minutes while stirring and then adjusted to pH 3.0 with a 20% aqueous solution of nitric acid. The reaction mixture was heated under reflux temperature conditions for 2 hours while stirring while dehydrating. After heating, the reaction mixture was adjusted to pH 8.0 with a 10% aqueous solution of sodium hydroxide. The precipitate obtained was filtered off to obtain a homogeneous and clear solution. Analysis of the resinous product obtained by solvent removal from the solution showed that it is a primary condensate of an etherified diguanamine formed from the diguanamine (1) and formaldehyde in a ratio of 1.9 moles of formaldehyde to a structural unit of the diguanamine as methylol, containing butyl ether groups and having an average degree of addition condensation of 1.6.

Example 19 Polymerization of an N-methylol derivative of a diguanamine and UV light resistance test of the resulting resin

In 10 ml of n-butyl alcohol was dissolved 5.0 g of an N-methylol derivative of diguanamine (1) obtained in the same manner as in Example 10 and prepared from diguanamine (1) and Formaldehyde was formed which was bound in a ratio of 7.2 moles of formaldehyde to one mole of the diguanamine, and then 0.025 g of p-toluenesulfonic acid was added as a curing catalyst. The resulting solution was placed on a galvanized steel sheet and then heated and cured at 140°C for 20 minutes.

Using a germicidal lamp (manufactured by Toshiba Corporation 19 W) as a UV light source, the thus-coated steel sheet, i.e., a test steel sheet, was exposed to UV light at a vertical distance of 25 cm for 200 hours. The surface gloss of the test steel sheet was measured according to JIS K 5400 (specular reflection at 60º). The gloss retention was found to be 97%.

Example 20 Polymerization of an N-methylol derivative of a diguanamine and UV light resistance test of the resulting resin

In 10 ml of n-butyl alcohol was dissolved 5.0 g of an N-methylol derivative of diguanamine (2) obtained in the same manner as in Example 11 and formed from the diguanamine (2) and formaldehyde combined in a molar ratio of 7.3:1, and then 0.025 g of p-toluenesulfonic acid was added as a curing catalyst. The obtained solution was placed on a galvanized steel sheet and then heated and cured at 140°C for 20 minutes.

Using a germicidal lamp (manufactured by Toshiba Corporation; 19W) as a UV light source, the thus-coated steel sheet, i.e., a test steel sheet, was exposed to UV light at a vertical distance of 25 cm for 200 hours. The surface gloss of the test steel sheet was measured according to JIS K 5400 (specular reflection at 60º). The gloss retention was found to be 98%.

As shown in Examples 19 and 20, the N-methylol derivatives of diguanamines, the derivatives belonging to the present invention, had excellent properties including excellent polymerizability and extremely low deterioration of gloss under UV irradiation.

Example 21 Crease resistance test of a fibre treatment containing an N-methylol derivative of a diguanamine

Deionized water was added to an N-methylol derivative of diguanamine (1) prepared in the same manner as in Example 10 and formed from diguanamine (1) and formaldehyde bonded together in a molar ratio of 7.2:1 to prepare a 10% aqueous solution of the derivative. To the solution was added 3% by weight (based on the solid content of the derivative) of secondary ammonium phosphate as a catalyst. A cotton cloth (cotton broadcloth No. 60) was immersed in the resulting solution and then padded. The cloth was preliminarily dried at 80°C for 5 minutes and then heated at 140°C for 5 minutes.

A crease resistance test was carried out according to JIS L 1059 (Monsanto method) using the thus treated fabric. It was found that the fabric had a crease resistance of 86% and thus had excellent crease resistance.

Any N-methylol derivative of a diguanamine, the derivative belonging to the present invention, can impart excellent crease resistance and the like to fibers when treated with the derivative as shown above. A thermosetting composition containing the diguanamine derivative therein is therefore extremely useful as a fiber treatment.

Example 22 Curing test of a water-based paint resin containing an N-methylol derivative of a diguanamine

To a solution prepared by gradually adding 1.84 g of dimethylethanolamine to 40.0 g of "Almatex WA 911" (product of Mitsui Toatsu Chemicals, Inc., NV: 60%) with stirring and then by adjusting the non-volatile content to 20% with deionized water, a 50 wt.% aqueous solution of 6.0 g of an N-methylol derivative of the diguanamine (1) prepared in the same manner as in Example 10 and formed from formaldehyde and the diguanamine (1) bonded to each other in a molar ratio of 7.2:1 was added and mixed. The resin solution thus obtained was applied to a galvanized steel sheet and then heated at 160°C for 20 minutes.

On the coating film of the thus coated steel sheet, bubbles, discoloration or the like were not observed at all. The surface gloss of the coating film was measured in accordance with JIS K 5400 (specular reflection at 60º). It was found that the film had a surface gloss of 98% and thus had exceptional smoothness and gloss. Furthermore, no peeling of the film was observed even when the film surface was rubbed 50 times with a cloth soaked in acetone. The film was therefore completely cured and was an excellent coating film.

Example 23 Curing test of a water-based paint resin containing an N-methylol derivative of a diguanamine

To a solution obtained by gradually adding 1.84 g of dimethylethanolamine to 40.0 g of "Almatex WA 911" (product of Mitsui Toatsu Chemicals, Inc., NV: 60%) with stirring and then adjusting the nonvolatile content to 20% with deionized water, was added and mixed with a 50 wt% aqueous solution of 5.9 g of an N-methylol derivative of the diguanamine (2) prepared in the same manner as in Example 11 and formed from formaldehyde and the diguanamine (2) bonded to each other in a molar ratio of 7.3:1. The resin solution thus obtained was applied to a galvanized steel sheet and then heated at 160°C for 20 minutes.

Blisters, discoloration and the like were not observed at all on the coating film of the steel sheet. The surface gloss of the coating film was measured in accordance with JIS K 5400 (specular reflection at 60º). It was found that the film had a surface gloss of 94%, thus showing excellent smoothness and gloss. Furthermore, no flaking was observed on the film even when the film surface was rubbed 50 times with a cloth soaked in acetone. It was therefore completely cured and was an excellent coating film.

As shown in Examples 21-23, each diguanamine derivative of the present invention has excellent water solubility, and a thermosetting composition containing the derivative is not only excellent as a resin to be used in an aqueous system such as a water-based paint resin, adhesive resin or fiber treatment, but also exhibits excellent curing and crosslinking properties when used as a paint resin. It is therefore extremely useful for a wide variety of uses.

Example 24 Curing test of a water-based paint resin containing an N-methoxymethyl derivative of a diguanamine

To a solution obtained by gradually adding 1.84 g of dimethylethanolamine to 40.0 g of "Almatex WA 911" (a product of Mitsui Toatsu Chemicals, Inc., NV: 60%) with stirring and then adjusting the nonvolatile content to 20% with deionized water, a 50 wt% aqueous solution of 6.8 g of an N-methoxymethyl derivative of the diguanamine (1) obtained in the same manner as in Example 15 and formed from formaldehyde and the diguanamine (1) bonded to each other in a molar ratio of 5.3:1 in a 50:50 (weight ratio) mixed solvent of butyl cellosolve and water and 0.15 g of p-toluenesulfonic acid were added and mixed therewith. The resulting resin solution was applied to a galvanized steel sheet and then heated at 160ºC for 20 minutes.

Blisters, discoloration or the like were not observed at all on the coating film of the steel sheet. The surface gloss of the film was measured in accordance with JIS K 5400 (specular reflection at 60º). It was found that the film had a surface gloss of 96%, thus showing excellent smoothness and gloss. Furthermore, no flaking was observed on the film even when the film surface was rubbed 50 times with a cloth soaked in acetone. It was therefore completely cured and was an excellent coating film.

As shown above, each etherified diguanamine of the present invention has excellent polymerizability, and in addition, a thermosetting resin composition containing the etherified diguanamine and a resin reactive therewith and therefore being curable is extremely useful as a water-based paint resin.

Example 25 Polymerization of an N-methoxymethylated diguanamine and weather resistance test of the resulting resin

In 10 g of methyl isobutyl ketone was dissolved 4.9 g of an N-methoxymethyl derivative of the diguanamine (2) obtained in the same manner as in Example 16 and formed from formaldehyde and the diguanamine (2) bonded together in a molar ratio of 4.9:1. To the obtained solution was added 47.2 g of "Almatex P 646" (a product of Mitsui Toatsu Chemicals, Inc., NV: 60%) and mixed therewith. The obtained resin solution was applied to a galvanized steel sheet and then cured by heating at 180°C for 50 minutes.

The exposure test of the thus coated steel sheet was carried out for 500 hours using a weather resistance meter. Neither blisters nor discoloration were observed on the surface of the coating film on the steel sheet. The surface gloss of the coating film was measured according to JIS K 5400 (specular reflection at 60º). The gloss retention was found to be 95%.

Example 26 Polymerization of a primary condensate of an etherified diguanamine and weathering resistance test of the resulting condensate

In 10 g of methyl isobutyl ketone was dissolved 5.0 g of a primary condensate of etherified diguanamine (1) obtained in the same manner as in Example 18 and having an average addition condensation degree of 1.6 per structural unit of diguanamine (1). To the obtained solution, 47.2 g of "Almatex P 646" (a product of Mitsui Toatsu Chemicals, Inc., NV: 60%) was added and mixed therewith. The obtained resin solution was applied to a galvanized steel sheet and then cured by heating at 160°C for 30 minutes.

The exposure test of the thus coated steel sheet was carried out for 500 hours using a weather resistance meter. Neither blisters nor discoloration were observed on the surface of the coating film of the steel sheet. The surface gloss of the coating film was measured in accordance with JIS K 5400 (specular reflection at 60º). The gloss retention was found to be 97%.

As shown in Examples 25 and 26, each of the etherified diguanamines and the primary condensates of the present invention has excellent polymerizability. In addition, a cured product obtained from a thermosetting resin composition containing the etherified derivative or the primary condensate and a resin curable by reaction therewith has excellent weather resistance. It is therefore extremely useful as a paint resin.

Example 27 Curing test of an epoxy-containing resin with a diguanamine (1)

In 100.0 g of butyl cellosolve was dissolved 100 g of an epoxy-containing resin ("Epicoat # 828"; a product of Shell Kagaku K.K.). To the resulting solution, 19.6 g of diguanamine (1) prepared in the same manner as in Example 1 was added and dissolved to prepare a resin solution. The resin solution was applied to a galvanized steel sheet, then heated at 110°C for 30 minutes and then at 200°C for 40 minutes. No flaking was observed on the thus-heated coating film of the steel sheet even after the film surface was rubbed 50 times with a toluene-soaked cloth. It was a fully cured, transparent and excellent coating film.

Example 28 Curing test of an epoxy-containing resin with a diguanamine (2)

A resin solution was prepared in a similar manner to Example 27 except that 18.9 g of the diguanamine (2) prepared in the same manner as Example 3 was used instead of 19.6 g of the diguanamine (1) prepared in the same manner as Example 1, and a coating film curing test of the film was carried out.

No flaking was observed on the thus-heated coating film of the steel sheet even after the film surface was rubbed 50 times with a toluene-soaked cloth. It was a fully cured, transparent, excellent coating film.

Example 29 Storage stability test of a thermosetting resin composition

In each example, an epoxy-containing resin and the diguanamine shown in Table 3 were mixed in the amounts indicated in that table. The resulting mixture was stirred for 15-30 minutes. ten in a double roller previously heated to 90-110ºC until the mixture became completely uniform. The mixture was taken out in the form of a sheet and then ground. The obtained sample was left to stand in a dryer maintained at 40ºC, whereby its storage stability was evaluated. The results are shown in Table 3.

It is clear from Table 3 that each thermosetting resin composition of the present invention exhibits excellent storage stability. Table 3

Example 30 Flexibility test of a cured resin product obtained from a thermosetting resin composition

100 g of an epoxy-containing resin ("Epicoat # 828"; a product of Shell Kagaku KK) and 19.6 g of the diguanamine prepared in the same manner as in Example 1 were mixed. The mixture was kneaded for 30 minutes in a double roll previously heated to 90-110°C until the mixture became completely uniform. The mixture was then taken out in the form of a sheet and then ground. The obtained sample was cured at 190°C for 3 hours to obtain a cured resin product. The Charpy impact strength of the cured resin product was measured as a criterion for flexibility. The results are shown in Table 4.

Incidentally, another cured resin product as a comparative example was prepared under optimum curing conditions in a similar manner to the above except that the dicyandiamide was used in place of the diguanamine in its optimum blending amount, and its Charpy impact strength was measured. Table 4

Table 4 shows that a cured resin product obtainable from each of the thermosetting resin compositions of the present invention has excellent flexibility.

Example 31

Weather resistance test of a cured coating film obtained from a thermosetting resin composition In 200 g of butyl cellosolve was dissolved 100.0 g of an epoxy-containing resin ("Almatex PD #7610"; a product of Mitsui Toatsu Chemicals, Inc.; epoxy equivalent of solid: 530). The diguanamine (11.1 g) prepared in the same manner as in Example 1 was added to the resulting solution and dissolved therein to obtain a resin solution. The resin solution was applied to a galvanized steel sheet and then heated and cured at 200°C for 40 minutes.

A weather resistance test was carried out by exposing the thus-coated steel sheet to light for 300 hours using a weather resistance meter. The surface gloss of the coating film on the steel sheet was measured according to JIS K 5400 (specular reflection at 60º). The gloss retention was found to be 94%.

As shown above, a cured resin product obtained from each of the thermosetting resin compositions of the present invention has excellent weather resistance and is extremely useful as a resin varnish.

Example 32 Test of a coating film of a powder coating resin obtained from a thermosetting resin composition

A resin solution of the thermosetting resin composition obtained in the same manner as in Example 31 was heated under reduced pressure to remove the solvent to obtain a resin in a solid form. The solid resin was coarsely ground by means of a coarse mill and then finely ground in an atomizer. The finely ground particles thus obtained were sieved through a 150-mesh sieve. The particles falling through the sieve were used for a test as a powder coating resin. The powder coating resin was applied to a bonded steel sheet by electrostatic coating to obtain a film thickness of about 50 µm and then heated at 200°C for 40 minutes.

The thus coated and heated coating film of the steel sheet had good smoothness by visual inspection. Furthermore, no flaking was observed on the film even after the film surface was rubbed 50 times with a toluene-soaked cloth. It was a fully cured, excellent coating film.

Using a germicidal lamp (manufactured by Toshiba Corporation; 19 W) as a UV light source, the thus coated steel sheet, i.e. a test steel sheet, was exposed to UV light was exposed at a vertical distance of 25 cm. Neither bubbles nor discoloration were observed on the surface of the coating film of the steel sheet. The surface gloss of the test steel sheet was measured according to JIS K 5400 (specular reflection at 60º). The gloss retention was found to be 96%. Thus, the coating film had excellent UV light resistance.

Example 33 Bonding test of a heat-curing resin composition

100 g of an epoxy-containing resin ("Epicoat #828"; a product of Shell Kagaku K.K.) and 15.7 g of the diguanamine (1) prepared in the same manner as in Example 1 were mixed. They were kneaded in a double roll previously heated to 90-110°C until they were completely and homogeneously mixed. Steel sheets were bonded using the thus kneaded resin. The resin was then cured at 200°C for one hour. The thus cured resin had a tensile shear bonding strength of 176 kg/cm2 at 25°C.

As shown above, each of the thermosetting resin compositions of the present invention has excellent adhesiveness and is extremely useful as an adhesive resin or the like.

Advantageous effects of the invention

The diguanamines of the present invention are useful in an extremely wide range of applications because they are excellent in weather resistance, UV light resistance and the like and can maintain expected functions in outdoor use and the like for a long period of time; they can provide methylol derivatives having extremely good water solubility; they are substantially free from restrictions as raw materials for resins used in aqueous systems such as water-based paints and exhibit excellent performance; they have characteristic properties such as having active amino groups with excellent reactivity with formaldehyde, epoxy compounds and the like and allow selection of a degree of methylol derivatization from a wide range due to the incorporation of eight active hydrogen atoms; and in addition, they can provide compounds, resins, compositions and the like having excellent properties such as flexibility, toughness, hardness, water resistance and curability. Moreover, the process for producing such diguanamines according to the present invention is excellent because the desired compound can be obtained in high yield and high purity while minimizing by-products by reacting the specific dicarbonitrile which can be obtained cheaply and dicyandiamide under specific conditions, and the process including the purification step is simple.

Such diguanamines have excellent polymerizability with various compounds such as aldehydes, epoxy compounds, carboxylic acids and isocyanates, and also have various excellent reactivities, so that the diguanamines are extremely useful as raw materials for resins and derivatives. They can provide, for example, derivatives extremely useful as curing agents and raw materials for various resins such as N-methyloldiguanamines obtained by reacting the diguanamines with aldehydes, etherified diguanamines and their primary condensates; thermosetting compositions containing these derivatives; and thermosetting resin compositions comprising the above diguanamines and epoxy-containing resins, the compositions being useful as paint resins and adhesive resins. The present invention is therefore excellent from an industrial point of view.

Claims (16)

1. Diguanamine represented by the following formula (1) wherein the binding sites for the 4,6-diamino-1,3,5-triazin-2-yl groups are the 2,5- or 2,6-positions, or is represented by the following formula (2) wherein the binding sites for the 4,6-diamino-1,3,5-triazin-2-yl groups are the 1,2-, 1,3- or 1,4-positions. 2. A process for producing a diguanamine which comprises reacting a dicarbonitrile represented by the following formula (3) where the binding sites for the cyano groups are the 2,5- or 2,6-positions, or is represented by the following formula (4): wherein the binding sites for the cyano groups are the 1,2-, 1,3- or 1,4-positions, with dicyandiamide in the presence of a basic catalyst. 3. The process of claim 2, wherein the basic catalyst is at least one compound selected from the group consisting of alkali metals, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alcoholates, alkali metal salts of dicyandiamide, alkaline earth metal salts of dicyandiamide, amines and ammonia. 4. The process according to claim 2, wherein the reaction is carried out using a solvent selected from the group consisting of non-aqueous protic solvents and aprotic polar solvents as the reaction solvent. 5. The process according to claim 2, wherein the reaction is carried out in a temperature range of 60°C to 200°C. 6. N-methyloldiguanamine obtained by an addition reaction of the diguanamine according to claim 1 and an aldehyde. 7. An etherified diguanamine obtained by an etherification reaction of the N-methyloldiguanamine according to claim 6 and at least one alcohol selected from alcohols having 1 to 20 carbon atoms, the etherified diguanamine containing at least one R₁OCH₂ group, wherein R₁ represents the residue of a group formed by removing a hydroxy group from the alcohol. 8. Primary condensate of an N-methyloldiguanamine obtained by addition condensation of the diguanamine according to claim 1, a condensable compound as optional reactant and a aldehyde and has an average degree of addition condensation of higher than 1 and at least one methylol group. 9. Primary condensate of an etherified diguanamine obtained by addition reaction or addition condensation of the diguanamine according to claim 1, a condensable compound as optional reactant and an aldehyde and then by etherification and optionally simultaneous condensation of the reaction product and at least one alcohol selected from alcohols having 1 to 20 carbon atoms and having an average degree of addition condensation higher than 1 and at least one R₁OCH₂ group, wherein R₁ is as defined above. 10. A thermosetting composition containing as an essential component at least one compound selected from the group consisting of N-methyloldiguanamine according to claim 6, the etherified diguanamine according to claim 7, the primary condensate of N-methyloldiguanamine according to claim 8 and the primary condensate of etherified diguanamine according to claim 9. 11. A thermosetting composition according to claim 10, which additionally comprises a resin curable by reaction with the essential component described in claim 10. 12. A paint resin composition comprising the thermosetting composition according to claim 11. 13. A thermosetting resin composition comprising the diguanamine according to claim 1 and an epoxy-containing resin. 14. A paint resin composition comprising the thermosetting resin composition according to claim 13. 15. A paint resin composition according to claim 14, which is a powder coating resin composition. 16. An adhesive resin composition comprising the thermosetting resin composition according to claim 13.