JPH066590B2 - New amidine, its production and use - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel amidine compound, a process for producing the same and its use as an epoxy curing catalyst and a urethane catalyst.

[Conventional technology]

 The compound having an amidine structure in the molecule is 1,8-
Diazabicyclo (5,4,0) undecene-7 (DBU
Hereinafter referred to as DBU. ) Is known, and pka is 11.5
It is a strong base and can be used as an epoxy curing catalyst, urethane catalyst, etc.
And is widely used. However, DBU is highly water soluble
In addition, it has high hygroscopicity and is difficult to handle during the rainy season and summer.
Yes. When used as an epoxy curing catalyst, the cured product
It has drawbacks such as high water absorption.

[Means for solving problems]

As a result of intensive studies to solve the above-mentioned drawbacks of the amidines, they have found that the novel amidine compound represented by the formula (1) improves the above problems, and completed the present invention.

The novel amidine of the present invention is represented by the general formula (1). That is, 6-disubstituted amino-1,8-diazabicyclo (5,4,0) undecene-7.

[In the formula (1), R ¹ and R ² are the same or different alkyl groups having 1 to 14 carbon atoms or benzyl groups, and the total number of carbon atoms is 3 to 16]. ] Of the above compounds, those having a total carbon number of 2 have insufficient water-insolubilizing effects, and if it is 17 or more, purification by distillation becomes difficult, and a large addition amount is required when used as an epoxy catalyst or urethane catalyst. It becomes necessary and is not preferable. A more preferable total carbon number is 6 to 13. The alkyl group is usually a straight chain, but may have a branched chain.

Examples of the novel amidine of the present invention include 6-methylbutylamino-1,8-diazabicyclo (5,4,0) undecene-7,6-methyloctylamino-1,8-diazabicyclo (5,4,0) undecene. -7 (hereinafter MOA-
DBU), 6-dibutylamino-1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter abbreviated as DBA-DBU), 6-butylbenzylamino-1,8-diazabicyclo (5,4,4) 0) abbreviated as undecene-7 (hereinafter BB _Z a-DBU), 6- dihexylamino diazabicyclo (5,4,0) undecene-7 and the like. Of course, it does not need to be a single item, and may be a mixture thereof.

The novel amidine compound according to the present invention is a lactam compound represented by the formula (2) (3-disubstituted amino-2-oxohexamethyleneimine), in which the imino group is cyanoethylated with acrylonitrile and hydrogenated to reduce it to an amino group. Then, it can be produced by cyclodehydration in the presence of an acid catalyst. The lactam compound of the formula (2) is, for example, 3
It is produced by alkylating and benzylating -amino-2-oxohexamethyleneimine by a known method.

[In the formula (2), R ₁ and R ₁ have the same meanings as in the case of the formula (1). ] In the cyanoethylation of the lactam compound, the acrylonitrile / lactam compound molar ratio is about 1,
After the reaction is completed, unreacted raw materials may be recovered. The reaction conditions for cyanoethylation are the same as in the conventional method, for example, Orga
The conditions described in nic Reaction 5 , 79-135 (1949) are adopted. This reaction requires an alkaline catalyst. For example, the catalyst is potassium hydroxide, sodium hydroxide, benzylmethylammonium hydroxide, sodium alkoxide or the like. The amount of the catalyst used is 5% or less, preferably 1 to 2%. The reaction temperature is 50 to 110 ° C, preferably 75
~ 95 ° C. The mixture of the lactam compound and the catalyst may be heated to the reaction temperature, and acrylonitrile may be added dropwise with stirring. In order to avoid polymerization of acrylonitrile, a polymerization inhibitor such as hydroquinone or hydroquinone monomethyl ether was added to acrylonitrile at 1% in advance.
Below, preferably 0.5% to 0.004% may be added. Since the cyanoethylation reaction is an exothermic reaction, the reaction temperature is controlled by the charging rate of acrylic. After the addition of acrylonitrile dropwise, stirring is continued at the same temperature for about 3 hours to complete the reaction. In this reaction, aromatic solvents such as benzene, toluene and xylene, and dioxane which does not react with acrylonitrile may be used as a reaction solvent. After completion of the reaction, the cyanoethylated product (1-cyanoethyl-3-disubstituted amino-2-oxohexamethyleneimine) can be isolated by distillation under reduced pressure, if necessary.

The cyanoethylated product obtained here can be reduced to a primary amino group by a conventional method of hydrogenating a nitrile group. For example, 100 g of cyanoethyl compound is hydrogenated in the presence of about 8 g of liquid ammonia and about 4 g of Raney nickel at 100 to 120 ° C. and hydrogen pressure of 50 kg / cm ² . The reaction is completed in about 3 hours.

Next, the method of dehydrating and cyclizing the N (3-aminopropyl) amide compound obtained here is a non-catalytic method, or in the presence of an acid catalyst such as phosphoric acid, para-toluenesulfonic acid or antimony trioxide, if necessary, benzene. , Toluene, xylene, tetralin, pseudocumene and other hydrocarbons,
Solvents that form an azeotrope with water, such as alcohols such as ethanol, octanols, ethylene glycol, propylene glycol, and glycols (boiling point 70 ° C-250
Water) to remove the water generated by the dehydration reaction to the outside of the system. When an acid catalyst is used, the amount used is 0.1 with respect to the N (3-aminopropyl) amide compound.
˜5%, preferably 0.5% to 2.0%. The amount of the azeotropic solvent used for dehydration is 0 to 500%, preferably 20 to 100% based on N (3-aminopropyl) amide. The end point of the reaction is the amount of water removed outside the system and the total amine value (HCl
Method). In this case, the unreacted 3-disubstituted amino-1- (3'-aminopropyl) -2-oxohexamethylene represented by the formula (3) was measured as a divalent base with a total amine value (HCl method). However, in equation (1) [In the formula (3), R ¹ and R ² each have the same meaning as in the case of the formula (1). The new amidine compound shown has a total amine value (HCl method) as a monovalent base even though it has an amidine group and an N, N-disubstituted amino group in one molecule. After distilling off the azeotropic solvent, the desired product is isolated by a method such as vacuum distillation.

The novel amidine compounds of the present invention or their organic or inorganic acid salts can be used as curing catalysts for epoxy resins. Examples of organic or inorganic acids include linear fatty acids (eg, acetic acid, propionic acid, caproic acid, lauric acid, stearic acid) and unsaturated fatty acids (eg, acrylic acid, crotonic acid, oleic acid, linoleic acid) and isoalkyl. Fatty acids (eg 2-ethylhexanoic acid), oxy fatty acids (eg lactic acid, glycolic acid, ricinoleic acid, hydroxystearic acid), dibasic fatty acids (eg succinic acid, adipic acid) and aromatic carboxylic acids (eg benzoic acid) Acid, salicylic acid, phthalic acid, terephthalic acid) and carboxylic acids (eg, carboxylic acid, cresol, resorcinol, catemar, phenol novolac resin), organic phosphates (eg, dibutyl phosphate, monolauryl phosphate), sulfuric acid ester, sulfuric acid Compounds (eg, lauryl monkey) Eto, dodecylbenzenesulfonic acid) or an enol acids (e.g., barbituric acid), tetraphenylborate or an inorganic acid (e.g., carbonic acid,
Sulfuric acid, phosphoric acid, hydrochloric acid).

The salt may be prepared by stirring and mixing the new amidine and the acid, and if necessary, heating and melting, and a solvent may be used. The solvent may be removed by means such as distillation after the neutralization reaction.

Epoxy resin used in the present invention is Interscience Publi
shers' Encyclopedia of Polymer Science and Technol
ogy Vol. 6, pp. 209-271 (1967). Epoxy resins include, for example, cyclic cycloepoxy compounds such as vinylcyclohexene diepoxide, dicyclopentaene diepoxide, ethylene glycol bis (3,4-epoxytetrahydrodicyclopentadiene-8-yl) -ether and diethylene glycol bis (3,3).
4-epoxycyclohexanecarboxylate), bis-3,4- (epoxycyclohexylmethyl) -succinate and other compounds containing two epoxycyclohexyl groups, or dicarboxylic acids and epichlorohydrin obtained by reacting in the presence of an alkali. Polyglycidyl ester compounds, dihydric alcohols, polyhydric alcohols, diphenols (eg bisphenol A,
It is obtained by etherifying tetrabromobisphenol A, bisphenol F, bisphenol S, a condensate of acetaldehyde and phenol), polyphenol or a novolak resin such as O-cresol novolac in the presence of epichlorohydrin or dichlorohydrin and alkali. Such a polyglycidyl ether compound. Mixtures of two or more of the above epoxy compounds can also be used.

In the present invention, not only the epoxy resin alone but also a compound that reacts with an epoxy compound, a so-called curing agent, can be used in combination. Examples of these are Encyclopedia o above
f Polymer Science and Technology, Vol. 6, pp. 209-271 (1967), J. of The Adhesion So
ciety of Japan] 15 , 102, 141 (1979) and polymer processing [Polymer Application (in Japanese) 25 , 383 (1976),
26 , 64, 120, 184 (1977)]. Chain aliphatic amines such as diethylenetriamine, triethylenetetramine, diethylaminopropylamine, N
-Cycloaliphatic polyamines such as aminoethylpiperazine and isophoronediamine, xylenediamine, polymers thereof, phenylenediamine, aromatic ring-containing amines such as diaminodiphenyl-methane and -sulfone, Sanyo Kasei polymide L-type, etc. Polyamides; ethylene oxide, propylene oxide and epoxy resin modified amines, cyanoethylated amines, ketiminated amines, modified amines such as phenol and formalin modified amines; polymer captans such as Dion3-800LC and Thiocol LP; anhydrous Phthalic acid, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, methyl nadic acid anhydride, tetra- or hexahydro-phthalic anhydride, methyl hexahydrophthalic anhydride or the above acid-free Acid anhydrides such as halides of water; 2-ethylhexanoic acid, benzoic acid, salicylic acid, adipic acid, phthalic acid, dodecanedicarboxylic acid, hydroxystearic acid, substituted and unsubstituted mono- and poly-, such as trimellitic acid Carboxylic acids; butylated melamine resins, amino resins such as butylated urea resins, p-
Oxybenzoic acid and formalin condensate, synthetic resin initial condensate such as phenol resin and poly (p-vinylphenol) resin; mono- or polyhydric phenols such as phenol and resorcin; decyl alcohol, stearyl alcohol, ethylene glycol, tri Alcohols and glycols such as methylolpropane; isocyanates such as tolylene diisocyanate, crude diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate, and their reaction products with glycols, active hydrogen compounds such as water, and polymers of the above isocyanates. Hydrazine derivatives such as dicyandiamide and organic acid hydrazide.

The amount of the novel amidine of the present invention or a salt thereof used is usually 0.01 to 20 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the epoxy compound.

The novel amidine and its salt of the present invention are dimethylbenzylamine, 2,4,6-tris (dimethylaminomethyl).
Phenol, 1,3,5-tris (dimethylaminopropyl) hexahydro-S-triazine, tetramethylguanidine, 2-methylimidazole, 2-ethyl-4-
Secondary and tertiary amines such as methylimidazole, DBU and salts thereof; Lewis acid such as BF ₃ or a known catalyst such as amine salt thereof may be used in combination.

Furthermore, the novel amidine compounds of the present invention or their salts with organic or inorganic acids can be used as reaction catalysts for isocyanate compounds. The organic or inorganic acid used for the salt action of the novel amidine and the method for producing the same are the same as described above.

The reaction of an isocyanate compound according to the present invention is a reaction between an active hydrogen-containing compound defined by the Tselebitinoff method and an isocyanate, a dimerization of an isocyanate, a formation reaction of uretidinedione or isocyanurate by trimerization, and a decarboxylation of 2 mol of isocyanate. It includes a carbodiimide formation reaction.

Examples of the organic polyisocyanate and the polyol of the active hydrogen compound used in the present invention include all of the raw materials usually used for the production of rigid, semi-rigid, flexible polyurethane foams, elastomer foams and polyurethane molded products.

Examples of the organic polyisocyanate include aromatic polyisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.), aliphatic polyisocyanates (hexamethylene diisocyanate, etc.), alicyclic polyisocyanates (isophorone diisocyanate, etc.) and their modified products (for example, carbodiimide modified) and Examples thereof include free isocyanate-containing prepolymers obtained by reacting these with a polyol.

Examples of the polyol include high-molecular polyols such as water of alkylene oxides (ethylene oxide, propylene oxide, 1,2- and 1,4-butylene oxide, etc.), polyhydric alcohols (glycols such as ethylene glycol and propylene glycol; glycerin, trimethylol). 3 or more OH such as propane, triethanolamine, pentaerythritol, sorbitol, sucrose
Group-containing polyol) and an amine compound (ethylenediamine, diethyltriamine, tolylenediamine, xylylenediamine, piperazine, N-aminoalkylpiperazine, N, N-dimethylaminopropylamine, cyclohexylenediamine, etc.). Polyether polyol; a polymer polyol obtained by reacting the polyether polyol with an ethylenically unsaturated monomer (acrylonitrile, styrene, methyl methacrylate, ptadiene, etc.) in the presence of a polymerization catalyst such as a radical generator (US Patent No. No. 3383351); Polyester polyol obtained by reacting polycarboxylic acid (succinic acid, sebacic acid, maleic acid, adipic acid, fumaric acid, phthalic acid, dimer acid, etc.) with the above polyhydric alcohol; polyester polyether poly Examples include oats and mixtures of two or more of these.

In the present invention, if necessary, an active hydrogen compound as a cross-linking agent or a chain extender can be used. For example, a low molecular weight polyol [triethanolamine, diethanolamine, ethylene glycol, diethylene glycol, butanediol, trimethylolpropane, glycerin, p-bis (2-hydroxyethyl) phenylene ether and the like] and polyamines (tolylenediamine, xylylenediamine, diaminodiphenylmethane, methylenebis-O-chloroaniline and the like).

Examples of the foaming agent used in the present invention include halogen-substituted aliphatic hydrocarbon-based foaming agents (chlorofluorocarbon, methylene chloride, etc.) and water.

If necessary, a surfactant (silicon foam stabilizer, etc.), a colorant, a filler, a flame retardant, a stabilizer and the like can be used.

The amount of the novel amidine compound of the present invention or an organic or inorganic acid salt thereof used is usually 0.01 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the polyol. If it is less than 0.01 part by weight, the catalytic activity is low and it takes too long to complete the reaction. In addition, the physical properties of the urethane foam obtained, especially the compressive strength, when the amount used exceeds 5 parts by weight.
(ILD) decreases.

The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 (Manufacturing method of DMA-DBU) 720 g (3.0 mol) of 3-dibutylamino-2-oxohexamethyleneimine [Formula (2)] was heated to 70 to 90 ° C., and sodium methoxide 30% methanol was added. After 20 ml of the solution was added and the methanol was removed under reduced pressure, 175 g (3.3 mol) of acrylonitrile was added dropwise over 50 minutes, and the mixture was stirred at the same temperature for 3 hours. After distilling off unreacted acrylonitrile under reduced pressure, 650 g of a fraction of 175 to 185 ° C./1 mmHg was obtained. Purity 98.3% by gas chromatography, characteristic infrared absorption −
From CN2250 cm ^-1, it was identified as ¹ -cyanoethyl-3-dibutylamino-2-oxohexamethyleneimine [formula (4)].

25 g of liquid ammonia was pressed into a mixture of 305 g of the cyanoethyl compound and 11 g of Raney nickel, and the hydrogen pressure was 45 to 50 kg.
Hydrogenation was carried out at a temperature of 100 to 120 ° C./cm ² pressure for about 3 hours.

298 g of crude 1- (3'-aminopropyl) -3-dimethylamino-2-oxohexamethyleneimine [formula (3)] was obtained. The total amine value (HCl method) is 370 and the theoretical value is 98.1.
%Met.

Next, 200 g of pseudocumene and 5 g of paratoluenesulfonic acid were added to 285 g of this 3-aminopropylated product, and the mixture was stirred at about 190 ° C for 8 hours under a nitrogen stream and the water produced by the intramolecular dehydration reaction was removed as an azeotropic mixture from the reaction system. Removed. The pseudocumene was distilled off and then purified by distillation under reduced pressure to obtain 205 g of the target compound [formula (1)].

Boiling point 148-157 ° C / 1mmHg Total amine value (HCl method) 201 [Theoretical value 201] Total amine value (HClO ₄ method) 400 [Theoretical value 402] Tertiary amine value (HCl method) 201 [Theoretical value 201] Total amine The values (HCl method and HClO ₄ method) and the tertiary amine value were almost the same as the theoretical values, and the purity by gas chromatography was 99.1%.

DBA-DBU is a pale yellow oil that is insoluble in water.

Examples 2 and 3 (Production Method of MOA-DBU and BB _Z A-DBU) 3-Methyloctylamino- and 3-butylbenzylamino-1,8-diazabicyclo (5,4,0) undecene-7 was used as an example. MOA-DB corresponding to each one in the same way as 1
I got U and BB _Z A-DBU.

The properties of these compounds are shown in Table 1. Shown in.

Example 4 (Curing catalyst effect of epoxy resin, curing of cresol novolak epoxy resin with phenol novolac resin) Cresol novolac epoxy resin (Sumitomo Chemical Industries' Sumi Epoxy ESCN 195XL, epoxy equivalent 199) 100 parts (following parts are parts by weight), phenol novolac DBA on 55 parts of resin (Dainippon Ink & Chemicals Inc. Burkham TD-2131, softening point 80 ° C)
-DBU or 2 parts of DBU were melted, mixed and crushed uniformly.
The powder was cured on a hot plate (170 ° C.) and its gel time was measured.

The gel time of DBA-DBU is 47, while the gel time of DBU is 46 seconds.
Seconds, and showed the same catalytic activity.

Example 5 Water absorption effect of epoxy resin 100 parts of liquid epoxy resin (diglycidyl ether of bisphenol A, Sumi Epoxy ELA-128 manufactured by Sumitomo Chemical Co., epoxy equivalent 186), liquid acid anhydride (methylhexahydrophthalic anhydride, Japan Chemical industry HN-5500E, acid value 667)
1 part or 2 parts of an amidine compound was added to 90 parts of the mixture to prepare a uniform solution with stirring. Put 6g of this solution into a 4mm thick mold,
It was cured at 100 ° C. for 2 hours and 130 ° C. for 7 hours. The cured product was allowed to cool to room temperature in a desiccator and used as a sample. Table 2. The water absorption of the sample was measured under the conditions shown in.

As is clear from Table 2, the water absorption of the sample cured with DMA-DBU is lower than that of DBU, and it does not change depending on the amount added.

Example 6 (Example of foaming urethane foam with vinyl chloride sheet and discoloration degree of vinyl chloride sheet) A so-called cold cure foam with vinyl chloride sheet was prepared using the following foaming formulation, and placed in an oven at 120 ° C. I investigated the discoloration of.

Raw material temperature: 25 ° C, 20 × 20 × 1 cm cast iron mold temperature:
40 ° C, Release agent: Bond Wax URT-35T (manufactured by Bond Wax KK.), Cure condition: 10 minutes at room temperature Foaming prescription: (Parts by weight) Sannix FA-703 (Note) 100 Triethanolamine 4 Water 2.5 catalyst 1.0 Crude MDI (105 index) 58.9 (Note) Sannix FA-703 (manufactured by Sanyo Chemical Industries) Hue (Hazen) 75 or less, OH value 33 ± 5, pH 5.5 to 7.5, water 0.1 or less, viscosity (25 ° C) Ethylene oxide-chipped polyol formulation with an analytical value of 800 ± 50 cps A 10 × 10 cm light brown slush molded PVC sheet is previously attached to the inner surface of the mold with a double-sided adhesive tape.

A predetermined amount of crude MDI was added to a homogeneous mixture of raw materials other than crude MDI of the foaming formulation, stirred with a high-speed stirrer for 7 seconds, and poured into the above mold.

When DBA-DBU was used as a catalyst, a good PVC integrated mold foam with a total density of 0.14 (same as below g / cm ³ excluding PVC sheet) was obtained. When MOA-DBU and BB _Z A-DBU were used as catalysts, respectively, good mold foams were obtained as with DBA-DBU, and the total densities were 0.13 and 0.14, respectively. For comparison, the total density when using DBU as a catalyst was 0.14.

The vinyl chloride-integrated molded foam obtained here was placed in an oven at 120 ° C., and the discoloration of the vinyl chloride sheet was examined.

[Effects of the Invention] The novel amidine obtained in the present invention is less water-soluble and less hygroscopic than DBU. Furthermore, even though it has a higher molecular weight than DBU, it also has an activity as an epoxy curing catalyst.
When used as a urethane catalyst, the discoloration of vinyl chloride is greatly improved compared to DBU when used as a urethane catalyst, and it is useful as an epoxy compound and a catalyst for various urethane production.

Claims (4)

[Claims] 1. An amidine compound represented by the formula (1). [In Formula 1, R ¹ and R ² are the same or different alkyl groups having 1 to 14 carbon atoms or benzyl groups,
Its total carbon number is 3-16. ] 2. A lactam compound represented by the formula (2), wherein the imino group is cyanoethylated with acrylonitrile, hydrogenated to reduce it to an amino group, and then dehydrated and cyclized in the presence of an acid catalyst. A method for producing an amidine compound represented by the formula (1): [In the formulas (1) and (2), R ¹ and R ² are the same or different alkyl groups having 1 to 14 carbon atoms or benzyl groups, and the total number of carbon atoms is 3 to 16]. ] 3. A method for using an amidine compound, which comprises curing an epoxy resin using an amidine compound represented by the formula (1) or a salt thereof as a catalyst. [In Formula 1, R ¹ and R ² are the same or different alkyl groups having 1 to 14 carbon atoms or benzyl groups,
Its total carbon number is 3-16. ] 4. A method for using an amidine compound, which comprises curing an isocyanate compound using an amidine compound represented by the formula (1) or a salt thereof as a catalyst. [In Formula 1, R ¹ and R ² are the same or different alkyl groups having 1 to 14 carbon atoms or benzyl groups,
Its total carbon number is 3-16. ]