JP2010059095A - Epoxy resin composition and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradation epoxy resin composition which includes an epoxy compound of PDC and has high tensile bond strength and low-temperature rapid cure property. <P>SOLUTION: A compound is represented by general formula (I). In the formula, n denotes an integer of 1-4. The epoxy resin composition includes the compound. A method of manufacturing the compound and a curing method of the composition are provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition containing a novel epoxy compound, which has a wide range of uses in adhesives, paints, electrical and electronic materials, and a method for producing the same.

  The present inventors efficiently used 2-pyron-4,6-dicarboxylic acid (hereinafter abbreviated as “PDC”) from a typical biomass resource, lignin, using a bioreactor. Has been established (Patent Document 1). In addition, the present inventors have reported a method for producing a polymer such as biodegradable polyester or polyamide using the bifunctionality of PDC (for example, Patent Document 2).

  On the other hand, epoxy resins are widely used as coating agents, adhesives, and the like due to their excellent cured properties, but conventional epoxy resin compositions are mixed with two components consisting of a main agent and a curing agent when used. The liquid type is the mainstream, and there is a problem that the measurement of the main agent and the curing agent and precise work at the time of mixing are required and the viscosity increases with time. As a solution to this problem, a one-component thermosetting epoxy resin composition has been developed, but the curing temperature is high and the curing time is long. Biodegradable epoxy resins are also known (for example, Patent Document 3), but the number is very small.

JP 2005-278549 A JP 2004-256747 A JP 2006-111654 A

  Accordingly, an object of the present invention is to provide a biodegradable epoxy resin composition having a high tensile adhesive strength and containing a PDC epoxy compound and having a low temperature fast curing property.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have made PDC to dehydrate a specific unsaturated alcohol to give an ester, and then epoxidize the ester, or in the presence of a dehydration condensing agent, It has been found that a novel epoxy compound of PDC can be obtained by reacting a specific epoxy alcohol with PDC. Moreover, the epoxy resin composition containing this epoxy compound and the hardening method of this composition were discovered, and it came to complete this invention.

  That is, (1) the present invention provides the following general formula (I):

[Wherein n represents an integer of 1 to 4. ]
The compound represented by these is provided.
(2) The present invention provides the compound according to (1), wherein n is 1.
(3) This invention provides the epoxy resin composition containing the compound as described in (1) or (2).
(4) The present invention provides the epoxy resin composition according to (3), further comprising a curing agent.
(5) In the present invention, the curing agent is selected from 4-methylcyclohexane-1,2-dicarboxylic anhydride, maleic anhydride, phthalic anhydride, succinic anhydride, and 4-methylphthalic anhydride. The epoxy resin composition described above is provided.
(6) The present invention provides the epoxy resin composition according to (4) or (5), which is an adhesive composition.
(7) The present invention relates to 2-pyron-4,6-dicarboxylic acid and R ¹ —OH (R ¹ is CH ₂ ═CH— (CH ₂ ) _n − N represents an integer of 1 to 4) to give an ester, and then epoxidize the ester, or 2-pyrone-4,6-dicarboxylic acid in the presence of a dehydrating condensing agent. The following formula:

[Wherein n represents an integer of 1 to 4. ]
A method for producing a compound according to (1) or (2), characterized by reacting an epoxy alcohol represented by the formula:
(8) The present invention provides a method for curing the composition, wherein the epoxy resin composition according to any one of (4) to (6) is cured at a temperature of 100 to 130 ° C.

  According to the present invention, it is possible to produce a biodegradable epoxy resin composition having a high tensile adhesive strength and a low temperature fast curing property. Therefore, the epoxy resin composition of the present invention can be suitably used particularly for an adhesive.

  The novel epoxy compound of the present invention has the following general formula (I):

[Wherein n represents an integer of 1 to 4. ]
It is represented by The novel epoxy compound of the present invention is preferably a diglycidyl ester of PDC in which n is 1 in the general formula (I).

The epoxy compound represented by the formula (I) of the present invention can be produced by the following two synthesis methods.
Synthesis method 1:

That is, an alcohol represented by the formula (III): R ¹ —OH (R ¹ represents CH ₂ ═CH— (CH ₂ ) _n —, n represents an integer of 1 to 4) is added to PDC. Dehydration reaction is carried out to ester (IV), and this ester (IV) is epoxidized by a conventional method. The synthesis method 1 is described in detail below.

  First, PDC and unsaturated alcohol represented by formula (III) are dehydrated in the presence of an acid catalyst to obtain a corresponding ester.

PDC is produced from a plant-derived low molecular weight compound such as lignin such as vanillin, syringaldehyde, vanillic acid, syringic acid or protocatechuic acid, or a mixture thereof, for example, by the fermentation method described in JP-A-2005-278549. Can be easily obtained.
Examples of unsaturated alcohols represented by formula (III) include 2-propen-1-ol (allyl alcohol), 3-buten-1-ol, 4-penten-1-ol, and 5-hexen-1-ol. Is mentioned. Allyl alcohol is commercially available, and other unsaturated alcohols can be synthesized by, for example, the method described in Japanese Patent Application No. 2006-212496. Theoretically, the unsaturated alcohol may be used in an amount of 2 equivalents or more relative to 1 mole of PDC, but it is preferably used in an amount of 10 equivalents or more in order to allow the PDC dehydration reaction to proceed smoothly.

  As the acid catalyst, various acids such as mineral acids such as sulfuric acid, chlorosulfuric acid and phosphoric acid, sulfonic acids such as p-toluenesulfonic acid and trifluoromethanesulfonic acid, heteropolyacid, solid acid, polymer-supported acid, etc. may be used. it can.

  The reaction may be performed for several hours at the reflux temperature of the reaction solvent. The reaction solvent is preferably one that can remove water under azeotropic conditions, and examples thereof include aromatic hydrocarbon solvents such as benzene, toluene, and xylene.

Alternatively, the corresponding ester (IV) may be obtained by reacting PDC with an unsaturated alcohol represented by the formula (III) in the presence of a dehydrating condensing agent.
As the dehydrating condensing agent, N.N′-diisopropylcarbodiimide (DIC), dicyclohexylcarbodiimide (DCC), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and the like can be used. The amount of the dehydrating condensing agent added is 1 to 3 equivalents, preferably 1.3 to 1.7 equivalents, per 1 mol of PDC.
For dehydration reaction, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, trimethylamine, triethylamine, N, N, N ', N'-tetramethylethylenediamine, diisopropylamine, diisopropylethylamine, N-methylpiperidine, 2 , 2,6,6-tetramethyl-N-methyldipiperidine, pyridine, N, N-dimethylaminopyridine, N-methylmorpholine, sodium ethoxide, and other bases are present.

  The reaction may be performed at a temperature of 0 ° C. to room temperature for about 1 hour. As a reaction solvent, ether solvents such as tetrahydrofuran, diethyl ether, 1,4-dioxane and dimethoxyethane; aromatic hydrocarbon solvents such as benzene, toluene and xylene; alicyclic hydrocarbon solvents such as cyclohexane and cyclohexanone Ester solvents such as acetate esters; ketone solvents such as acetone and methyl ethyl ketone; diol solvents such as 1,3-propanediol and 1,4-butanediol can be used.

  The ester (IV) thus obtained is subjected to an epoxidation reaction with a peroxide, such as m-chloroperbenzoic acid, to quantitatively obtain the compound of formula (I).

  Synthesis method 2:

That is, in the presence of a dehydrating condensing agent, PDC is reacted with an epoxy alcohol represented by the above formula (II) (wherein n represents an integer of 1 to 4), to thereby form the formula (I). A compound is obtained. Examples of the epoxy alcohol of the formula (II) include 2,3-epoxy-1-propanol (glycidol), 3,4-epoxy-1-butanol, and 4,5-epoxy-heptanol. Glycidol is commercially available, and other epoxy alcohols can be easily obtained by epoxidizing the corresponding unsaturated alcohols.
Alternatively, the compound of formula (I) may be obtained by converting PDC to acid chloride with thionyl chloride or the like, and reacting this acid chloride with the epoxy alcohol of formula (II) in the presence of a base.

  The epoxy alcohol of the formula (II) may be used in an amount of 1 to 3 equivalents, preferably 1.3 to 1.7 equivalents, relative to 1 mol of PDC. Further, the dehydrating condensation agent that can be used and the amount of addition thereof are the same as those in Synthesis Method 1.

The composition of the present invention comprises an epoxy compound of formula (I) obtained by the above method, preferably further comprising a curing agent. As the curing agent, various acid anhydrides and polyamines can be used, but when curing is performed under heating, for example, maleic anhydride, succinic anhydride, phthalic anhydride, 4-methylphthalic anhydride, 4 -It is preferable to use acid anhydrides such as methylcyclohexanedicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, tetrahydrophthalic anhydride. Among these, maleic anhydride, succinic anhydride, phthalic anhydride, 4-methylphthalic anhydride, or 4-methylcyclohexanedicarboxylic anhydride is more preferable.
The curing agent has an equivalent ratio (curing agent / epoxy compound) to the epoxy compound of formula (I) in the range of 0.3 to 1.5, and is included in the range of 30 to 60% by mass in the total amount of the composition. Preferably it is.

  When the epoxy resin composition of the present invention is used as an adhesive, for example, the epoxy resin composition of the present invention is interposed between materials such as glass, ceramics, metal, and heat-resistant plastic, It can be carried out at a relatively low temperature of 100 to 130 ° C. for about 10 minutes to about 1 hour, preferably about 10 to about 30 minutes, while applying a pressure of up to 50 MPa if necessary.

  In the curing reaction, general curing accelerators such as amine compounds, imidazole compounds, imidazoline compounds, and amide compounds may be added. Further, in the composition of the present invention, a reactive diluent, a plasticizer, an inorganic filler such as silica, a flame retardant, a mold release agent, an antifoaming agent, an anti-settling agent, as long as the effects of the present invention are not impaired. Antioxidants, silane coupling agents, dyes, pigments, colorants and the like can be blended.

  The composition of the present invention can be used for adhesives, coating agents, paints, electrical and electronic materials, and the like. Further, the adhesive composition of the present invention is applicable to various glasses, ceramics, metals, heat resistant plastics and the like.

  The compound of the formula (I) of the present invention can be suitably used as a raw material for producing biodegradable green plastics containing PDC in addition to the main ingredient of the above composition. For example, a compound of formula (I) can be reacted with a diol, dicarboxylic acid or diamine, respectively, to produce poly (ester-ether), poly (ester-ester), poly (ester-amine).

  EXAMPLES Next, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples at all.

Production Example 1 2-pyrone-4,6-dicarboxylic acid diglycidyl ester (synthesis method 1)
In a 100 ml four-necked flask equipped with a calcium chloride tube, a football-type magnetic stirrer, a Dean-Stark apparatus, and a Dimroth condenser, PDC (1.0 g, 5.43 mmol), allyl alcohol (75 ml), dry benzene (75 ml) ), P-toluenesulfonic acid monohydrate (0.1 g) was added as a catalyst, and the mixture was reacted for 6 hours under reflux at the boiling point. During the reaction, from the Dean Stark apparatus, water-containing benzene was withdrawn from time to time, and the corresponding amount of dry benzene was added 10 times. After completion of the reaction, the liquid was distilled off under reduced pressure. Methanol (25 ml) was added to the resulting light brown solid, heated to 60 ° C to dissolve, cooled to -5 ° C, and PDC diallyl ester (DAPDC) was regenerated. Crystallize, collect by filtration and dry. Yield 97.5%, 1.40 g. Melting point 59.8 ° C (DSC, peak temperature at a heating rate of 10 ° C / min).
¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): 7.48 (1.0H, d, J = 0.9 Hz), 7.12 (1.0H, d, J = 1.1 Hz), 6.01-5.88 (2.1H, m ), 5.34 (4.4H, dt, J = 20.8, 8.6 Hz), 4.79 (4.5H, t, J = 2.8 Hz).
¹³ C-NMR (300 MHz, CDCl ₃ ) δ (ppm): 161.95, 159.44, 158.53, 149.43, 142.90, 130.70, 130.60, 122.64, 120.02, 119.92, 108.22, 67.24, 67.06.
FT-IR (Liquid, ν (cm ^-1 )): 3091, 2950, 1734, 1647, 1560, 1452, 1414, 1398, 1370, 1328, 1247, 1173, 1116, 982, 942, 869, 779, 762, 713, 652, 557.

Next, the DAPDC (0.302 g, 1.14 mmol) obtained above and chloroform (5 ml) were placed in a 100 mL four-necked flask equipped with a calcium chloride tube, a football-type magnetic stirrer and a Dimroth reflux tube and stirred. . A solution of m-chloroperbenzoic acid (1.44 g, 5.44 mmol) in chloroform (60 ml) was added, and the mixture was heated to 66 ° C. in an oil bath and refluxed at the boiling point for 5 days. The solid produced after the reaction was removed by filtration, and the filtrate was washed once each with 10% -Na ₂ SO ₃ aqueous solution, 0.05 M-hydrochloric acid aqueous solution and saturated brine, and dried over anhydrous magnesium sulfate. After removing the desiccant by filtration, the solvent was distilled off under reduced pressure, and the resulting yellow viscous liquid was dissolved in methanol (10 ml) at 60 ° C. The colorless needle crystals that precipitated upon cooling to −5 ° C. were collected by filtration to give the title compound (DGPDC) in 89% yield (0.301 g yield). Melting point 59.8 ° C (DSC, peak temperature at a heating rate of 10 ° C / min).
¹ H-NMR (300 MHz, CDCl ₃ ) δ (ppm): 7.52 (1.0H, d, J = 1.5 Hz), 7.16 (1.0H, d, J = 1.5 Hz), 4.65 (2.2H, ddd, J = 14.6, 11.9, 2.6 Hz), 4.14 (2.2H, ddd, J = 13.4, 6.9, 5.4 Hz), 3.30 (2.1H, tt, J = 5.3, 2.0 Hz), 2.88 (2.2H, q, J = 4.7 Hz), 2.70-2.67 (2.2H, m).
¹³ C-NMR (300 MHz, CDCl ₃ ) δ (ppm): 161.95, 159.17, 158.49, 149.02, 142.36, 123.14, 108.45, 67.32, 66.99, 48.71, 48.69, 44.65, 44.56.
FT-IR (liquid, ν (cm ^-1 )): 3086, 3005, 1738, 1641, 1564, 1398, 1358, 1327, 1245, 1176, 1118, 982, 907, 861, 762, 709, 668, 615, 559, 505, 440, 404.

Production Example 2 2-pyrone-4,6-dicarboxylic acid diglycidyl ester (Synthesis Method 1)
PDC (1.00 g, 5.43 mmol) and allyl alcohol (1.02 ml, 15.0 mmol) in THF (20 ml) were placed in a 100 ml four-necked flask equipped with a calcium chloride tube and a football-type magnetic stir bar and stirred. . Cool to 0-5 ° C and add N, N'-diisopropylcarbodiimide (DIC) (1.64, 13.0 mmol) and 4- (N, N-dimethylamino) pyridine (DMAP) (0.133 g, 1.09 mmol) in THF (20 ml) The solution was added dropwise over 10 minutes. Thereafter, the mixture was stirred for 30 minutes, concentrated under reduced pressure at room temperature or lower to reduce the amount of the solution to about 1/2, cooled to 0 to 5 ° C., and the by-product urea derivative was removed by filtration. The solvent was distilled off under reduced pressure, chloroform (50 ml) was added, washed once with 0.05M hydrochloric acid, distilled water and saturated brine, dried over anhydrous magnesium sulfate, the desiccant was filtered off and concentrated under reduced pressure. . This solution was purified by 5φ × 20 cm 200 mesh silica gel column chromatography (developing solvent: chloroform: THF = 20: 1). The first effluent was collected, distilled off under reduced pressure, and recrystallized with diisopropyl ether to obtain DAPDC. Obtained as a white solid solid in 95.0% yield (1.36 g yield).
Then, in the same manner as in Production Example 1, the title compound was obtained in a yield of 87% (a yield of 0.294 g). The melting point, ¹ H-NMR, ¹³ C-NMR and FT-IR spectrum of the compound were the same as those of DGPDC obtained in Production Example 1.

Production Example 3 2-pyrone-4,6-dicarboxylic acid diglycidyl ester (Synthesis Method 2)
PDC (10.0 g, 54.3 mmol), glycidol (11.1 g, 150 mmol), and THF (50 ml) were added to a 100 ml four-necked flask equipped with a calcium chloride tube and a football-type magnetic stirrer and stirred. After cooling to 0 to 5 ° C., a solution of DIC (16.4 g, 130 mmol) and DMAP (1.31 g, 10.8 mmol) in THF (27 ml) was added dropwise over 10 minutes. Thereafter, the mixture was stirred for 20 minutes, concentrated under reduced pressure at room temperature or lower to reduce the amount of the solution to about 1/2, cooled to 0 to 5 ° C., and the by-product urea derivative was removed by filtration. The solvent was distilled off under reduced pressure, 50 ml of chloroform was added, washed once each with 0.05M hydrochloric acid, distilled water and saturated brine, dried over anhydrous magnesium sulfate, the desiccant was filtered off and evaporated under reduced pressure. . Methanol (20 ml) was added and dissolved at 60 ° C, allowed to cool to room temperature, and then cooled to 0 to 5 ° C to give the title compound as colorless needle crystals in a yield of 81.5% (yield 13.11 g). It was. The melting point, ¹ H-NMR, ¹³ C-NMR, and FT-IR spectrum of the compound were the same as those of DGPDC obtained in Production Example 1.

Example 1
DGPDC (0.50 g, 1.69 mmol) and maleic anhydride (MA) (0.282 g, 2.88 mmol) as a hardener are placed in a test tube equipped with a magnetic stir bar, and the inside of the test tube is purged with nitrogen and heated to 40 ° C. While stirring, the mixture was mixed. Furthermore, N, N-dimethylbenzylamine (0.025 ml) was added as a curing accelerator and degassed under reduced pressure to obtain a pale yellow transparent viscous liquid adhesive composition. Apply the adhesive composition so that it is uniform on both sides of the 5.0 × 28.0 mm end face (surface roughness Ra = 0.6 to 0.7 μm) of a 5.0 × 28.0 × 50.0 mm stainless steel (SUS306, Six Nine purity) plate. While maintaining the thickness at 0.10 mm, it was cured at 130 ° C. for 30 minutes. After returning to normal temperature, the tensile bond was measured with an Instron tensile tester (“Hydraulic Servo Fatigue Tester FT-5S” manufactured by Kakinomiya Seisakusho) in a constant strain rate mode with a strain rate of 0.6 / sec based on JIS K6849. The strength was 41.9 MPa, and it was found that a strong adhesive effect was exhibited. From the observation of the fracture surface, it was found that the material was broken near the center of the cured adhesive composition film, not at the interface peeling. Further, from the stress-strain curve (not shown), the cured adhesive composition film showed almost no elongation strain and was broken at a strain within 0.2%.

Example 2
An adhesion test was conducted in the same manner as in Example 1 except that phthalic anhydride (PA) (0.423 g, 2.88 mmol) was used as a curing agent. The tensile bond strength was 66.4 MPa, and it was found that an extremely strong bonding effect was exhibited.

Examples 3 and 4
An adhesion test was performed in the same manner as in Examples 1 and 2 except that a six nine purity iron plate was used instead of SUS306 (Examples 3 and 4 respectively). The respective tensile adhesive strengths are shown in Table 1 together with the results of Examples 1 and 2.

Comparative Examples 1-4
An adhesion test was conducted in the same manner as in Examples 1 and 2 except that bisphenol A diglycidyl ether (BADGE), which is well known as an epoxy resin, was used instead of DGPDC (Comparative Examples 1 and 2, respectively). Further, an adhesion test was conducted in the same manner as in Examples 3 and 4 except that BADGE was used instead of DGPDC (Comparative Examples 3 and 4 respectively) (Table 1).

  As is apparent from Table 1, the epoxy resin composition of the present invention exhibited a tensile adhesive strength substantially equal to or higher than that of the conventional epoxy resin composition.

Claims (8)

The following general formula (I):

[Wherein n represents an integer of 1 to 4. ]
A compound represented by   The compound according to claim 1, wherein n is 1.   The epoxy resin composition containing the compound of Claim 1 or 2.   The epoxy resin composition according to claim 3, further comprising a curing agent.   The epoxy resin composition according to claim 4, wherein the curing agent is selected from 4-methylcyclohexane-1,2-dicarboxylic anhydride, maleic anhydride, phthalic anhydride, succinic anhydride, and 4-methylphthalic anhydride. .   The epoxy resin composition according to claim 4 or 5, which is an adhesive composition. 2-pyron-4,6-dicarboxylic acid is R ¹ -OH (R ¹ is CH ₂ = CH- (CH ₂ ) _n- , where n is 1 Dehydration reaction to give an ester and then epoxidize the ester, or 2-pyrone-4,6-dicarboxylic acid in the presence of a dehydrating condensing agent:

[Wherein n represents an integer of 1 to 4. ]
The method for producing a compound according to claim 1, wherein an epoxy alcohol represented by the formula is reacted.   A method for curing the composition, comprising curing the epoxy resin composition according to any one of claims 4 to 6 at a temperature of 100 to 130 ° C.