JP2002284791A - Polycarboxylic acid and epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarboxylic acid having excellent biodegradability. SOLUTION: The polycarboxylic acid having biodegradability is produced by dissolving a sugar compound and/or a lignin substance in a polyol and reacting the polyol solution with a polycarboxylic acid anhydride.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable polycarboxylic acid, an epoxy resin composition containing the same, and a cured product of the composition.

[0002]

2. Description of the Related Art Synthetic polymers generally do not have biodegradability, unlike natural polymers, and are one of the causes of deterioration of the global environment. Therefore, there is a strong demand for the development of a polymer that does not cause environmental degradation even when disposed in a natural environment. On the other hand, vegetable components such as cotton, hemp, wood, and starch have the characteristic that they are naturally decomposed by microorganisms in the soil when discarded, and are very desirable materials from the viewpoint of global environmental protection. is there. However, it is difficult to use such a vegetable component as it is as a reaction material or a molding material.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polycarboxylic acid having excellent biodegradability, an epoxy resin composition containing the same, and a cured product of the composition.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, there are provided a polyvalent carboxylic acid shown below, an epoxy resin composition containing the same, and a cured product of the composition. (1) A biodegradable polycarboxylic acid characterized by being formed by reacting a polycarboxylic anhydride with a polyol solution formed by dissolving a sugar compound and / or a lignin substance in a polyol. (2) (a) vegetable powder having a hydroxy group and / or
Alternatively, a polycarboxylic acid comprising a reaction product of a short fiber, (b) a sugar compound and / or a lignin substance, (c) a polyol, and (d) a polycarboxylic anhydride. (3) An epoxy resin composition comprising the polycarboxylic acid of claim 1 or 2 and an epoxy resin. (4) A cured epoxy resin obtained by curing the epoxy resin composition of (3).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The hydroxyl group-containing plant powder used in the present invention includes solid polysaccharide powders such as cellulose, den powder, chitin, chitosan, pulp powder, bagasse powder, wood powder, tea husk powder, and the like. Examples include various natural polymer powders that are hardly soluble or insoluble in polyols such as coffee bean powder. The average particle size of the vegetable polymer powder is 3 μm to 5 mm, preferably 10 μm to 2 mm. When the average particle size of the vegetable polymer powder is larger than the above range, the miscibility with the polyol solution is deteriorated, and the reactivity with the polycarboxylic acid anhydride is also deteriorated. Examples of the hydroxyl group-containing short plant fiber used in the present invention include natural plant polymer fibers such as cotton fiber, hemp fiber, banana fiber, pulp, wood, and coconut shell fiber. The thickness of this vegetable polymer fiber is 3 μm to 2 mm,
Preferably it is 0.5 to 1 mm. Fiber length is 5mm
Or less, preferably 3 mm or less. If the size of the short vegetable fiber is larger than the above, the miscibility with the polyol solution becomes worse and the reactivity with the polyvalent carboxylic anhydride also becomes worse.

As the saccharide compound used in the present invention, various conventionally known soluble compounds are used. Such include monosaccharides, oligosaccharides, polysaccharides, sugar alcohols and the like,
Any material can be used as long as it is soluble in the polyol. Such sugar compounds include, for example, molasses, molasses, glucose, galactose, xylose, lactose, mannose, talose, rhamnose, arabinose, glucosyl mannose, lyxose, allose, altrose, growth, idose, ribose, erythrose, threose. , Psicose, fructose, sorbose, tagatose, pentulose, tetroose, sucrose, maltose, isomaltose, cellobiose, lactose, trehalose, koujibiose, sophorose, nigerose, laminaribiose, isomaltose, gentiobiose, meribiose, branteo, northern Vicia North, Agarobiose, Silaviose,
Rutinose, primeprose, xylobiose, rhodimeniose, erythritol, mesoerythritol, maltitol, lactitol, D-threitol, D-arabinitol, ribitol, xylitol, sorbitol, galactitol, D-mannitol, allitol,
In addition to higher alditols and the like, starch, dextran, mannan, pectin, pectic acid, alginic acid, chitosan and the like can be mentioned.

[0007] The lignin substance used in the present invention includes lignin and modified products thereof. This lignin substance
It is a polymer separated from wood, bamboo, straw, or the like and having a molecular weight of 800 to 10,000 formed by condensation of a structural unit having phenylpropane as a skeleton, and is a conventionally known substance. This is usually handled in powder form.
In the present invention, the lignin substance is used in the form of a solution by dissolving it in a polyol. The polyol used in the present invention is a liquid compound containing at least two hydroxyl groups in the molecule. Examples of such a compound include ethylene glycol, dinitylene glycol, 1.4-butanediol, and 1.6-. Low molecular weight polyols such as hexanediol, neopentyl glycol, trimethylolpropane, glycerin, triethanolamine, and sorbitol: polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and ethylene oxide / propylene oxide copolymer: Polycaprolactone, poly-β-methyl-δ-
Examples include butylolactone, polyesters from diols and dibasic acids, and the like. Other examples include a hydroxyl group-containing liquid polybutadiene, polycarbonate diol, and acrylic polyol.

The polyhydric carboxylic anhydride used in the present invention includes divalent to hexavalent, preferably divalent to tetravalent carboxylic acid anhydrides, and preferably divalent carboxylic acid anhydrides are used. Such a polycarboxylic anhydride is a conventionally known substance and can be represented by, for example, the following general formula (1).

Embedded image In the above formula, R represents a divalent organic group such as a divalent aliphatic group and a divalent aromatic group. The divalent aliphatic group includes a chain or cyclic one, and the chain includes an alkylene group having 1 to 12 carbon atoms, preferably 2 to 8 carbon atoms. The formula includes 5 to 12, preferably 6 to 8 cycloalkylene groups. The divalent aromatic group includes an arylene group and an aryldialkylene group. These two
A substituent, for example, a carboxyl group, an acid anhydride group, an amino group, and the like may be bonded to the valent aliphatic group and the divalent aromatic group. Illustrative examples of the polycarboxylic anhydride include, for example, malonic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, pimelic anhydride, suberic anhydride, and azelaic anhydride. , Methylnadic anhydride, alkenyl succinic anhydride, aliphatic polycarboxylic anhydrides such as hexahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, And aromatic polycarboxylic anhydrides such as phthalic anhydride.

In the first method for producing a polycarboxylic acid according to the present invention, first, a sugar compound and / or a lignin substance (hereinafter also referred to as a sugar compound) and a polyol are mixed,
A polyol solution containing a sugar compound and / or a lignin substance in a dissolved state is prepared. In this case, the use ratio of the sugar compound or the like is 0.1 to 10 parts by weight per 1 part by weight of the polyol,
Preferably, the proportion is 0.5 to 5 parts by weight. If the use ratio of the saccharide compound or the like is too large, it is difficult to uniformly dissolve in the polyol, and a uniform polyol solution cannot be obtained.

Next, in the present invention, a polycarboxylic anhydride is mixed with a polyol solution containing the above-mentioned saccharide compound and the like in a dissolved state, and an esterification reaction is carried out. In the present invention, it is preferable that a catalyst is present in the reaction mixture. As the catalyst in this case, a conventionally known esterification reaction catalyst can be used. The reaction temperature is 30 to 150 ° C, preferably 50 to 100 ° C, and the reaction stress is normal pressure or reduced pressure.

The esterification reaction of the polycarboxylic anhydride with the sugar compound or the like can be represented by the following formula.

Embedded image In the above formula, [A] represents a residue obtained by removing a hydroxyl group contained in a polysaccharide compound and / or a lignin substance. R represents a divalent organic group.

In the present invention, as can be seen from the above reaction formula, the hydroxyl groups contained in the polyol solution (that is, the total amount of the hydroxyl groups contained in the saccharide compound and the hydroxyl groups contained in the polyol) 1 When one mole of the polycarboxylic anhydride reacts with respect to the mole, a free carboxyl group (—COOH)
An esterification reaction product containing moles is obtained. In the present invention, the ratio of the free carboxyl groups contained in the reaction product can be adjusted by the amount of the polycarboxylic anhydride used. In the case of the present invention, the use ratio of the polyvalent carboxylic anhydride is calculated by converting one carboxylic anhydride group into two equivalents with respect to the equivalent number of all free hydroxyl groups (—OH groups) contained in the polyol solution. Then, 1.6 to 4 equivalents,
Preferably it is 2-3 equivalents. The esterification reaction product of the present invention is liquid or solid at room temperature.

In the second method for producing a polycarboxylic acid according to the present invention, first, a sugar compound and / or a lignin substance and a polyol are mixed to prepare a polyol solution containing the sugar compound and the like in a dissolved state. In this case, the ratio of the sugar compound used is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 1 part by weight of the polyol.

Next, in the present invention, a paste-like mixture is prepared by uniformly mixing the above-mentioned polyol solution containing the saccharide compound and the like with the above-mentioned vegetable powder or short fiber (hereinafter, also simply referred to as a polymer). obtain. The proportion of the polymer used is 30 to 100% by weight, preferably 50 to 80% by weight based on the polyol solution.
%, Especially in the case of coffee bean powder,
%, Especially 50 to 70% by weight in the case of wood flour. If the proportion of the polymer used is too large, it becomes difficult to uniformly mix the polymer and the polyol. On the other hand, if the proportion is too small, the microbial degradability of the resulting polycarboxylic acid is undesirably reduced.

In the present invention, a polycarboxylic anhydride is added to and mixed with the paste-like polymer mixture obtained as described above to cause an esterification reaction. The reaction temperature is 30
To 150 ° C., preferably 50 to 100 ° C., and normal pressure or reduced pressure is adopted as the pressure. The usage ratio of the polycarboxylic anhydride is 1.6 to 4 as the number of carboxyl groups of the polycarboxylic anhydride relative to the total number of hydroxyl groups contained in the polymer, polyol, sugar compound and the like. Double equivalent,
Preferably it is 2-3 equivalents. In the present invention, it is preferable to add a catalyst for the esterification reaction to the polymer mixture.

The esterification reaction product thus obtained is a solid or solid-liquid mixture containing free carboxyl groups. The proportion of free carboxyl groups contained in the reactive product can be adjusted by the amount of polycarboxylic anhydride used. In the case of the present invention, the ratio of the polyvalent carboxylic anhydride used is such that one carboxylic anhydride group is converted into 2 equivalents with respect to the equivalent number of all free hydroxyl groups (-OH groups) contained in the reaction raw materials. Then, 1.6 to 4 equivalents, preferably 2 to 3 equivalents. The esterification reaction product of the present invention is liquid or solid at room temperature.

The polycarboxylic acid according to the present invention contains a biodegradable product in its molecule, is excellent in biodegradability, and can be applied to various uses as a biodegradable reaction raw material. it can. According to the present invention, various compositions containing a polyvalent carboxylic acid are provided, and a preferred composition is an epoxy resin composition.

In the epoxy resin composition comprising the polyvalent carboxylic acid and the epoxy resin according to the present invention, various types of conventionally known epoxy resins which are solid or liquid at room temperature are used. Examples of such a resin include a diglycidyl ether type epoxy resin such as a bisphenol A type epoxy resin and a bisphenol F type epoxy resin; a phenol novolak type epoxy resin;
Novolak type epoxy resins such as cresol novolak type epoxy resins; glycidyl ester type epoxy resins; glycidylamine type epoxy resins; linear aliphatic type epoxy resins; heterocyclic type epoxy resins; halogenated epoxy resins and the like.

The epoxy resin composition may contain, if necessary, various auxiliary components such as a curing accelerator, a filler, a coloring agent, a flame retardant, and a release agent. As the curing accelerator, conventional ones, for example, imidazole compounds, diazabicycloundecene and its phenol salt, triphenylphosphine, tertiary amine, amine adduct latent curing accelerator, dicyandiamide and the like are used. As the filler, alumina, silica, magnesia,
Examples include antimony trioxide, magnesium carbonate, calcium carbonate, mica, and clay.

The amount of the polyvalent carboxylic acid in the epoxy resin composition is 0.8 to 2 equivalents, preferably 1 to 1.5 equivalents, of the epoxy group equivalent number of the epoxy resin.

The epoxy resin composition of the present invention acts as a curing agent for the polycarboxylic acid, and when heated, the polycarboxylic acid reacts with the epoxy resin to crosslink the polycarboxylic acid. A cured product as an agent can be obtained. Since the cured product has a biodegradable polyvalent carboxylic acid moiety in its structure, the cured product is biodegradable and biodegradable from that moiety. The epoxy resin composition of the present invention shows a solid state or a liquid state and is easily cured by heating, and is used as a molding material or a coating material. When used as a molding material, examples of the molding method include a transfer molding method, an injection molding method, a compression molding method, a cast molding method, and a dipping molding method.
When used as a coating material, examples of the coating method include a fluid immersion method, an electrostatic spray method, and a brushing method.

[0022]

Next, the present invention will be described in more detail with reference to examples.

Example 1 0.5 g of acidolisis lignin was dissolved in 1.55 g of ethylene glycol at 50 ° C., and succinic anhydride was added thereto.
3 g and 5 drops of dimethylaniline were added, followed by stirring at 80 ° C. for 3 hours. The infrared absorption spectrum of the obtained esterification product (polycarboxylic acid product) shows 1740 cm
(Ester) and peaks at around 1800 cm (carboxylic acid).

Example 2 A polycarboxylic acid was obtained in the same manner as in Example 1, except that kraft lignin was used instead of acidolisis lignin. It was confirmed by IR spectrum that the structure contained an ester group and a carboxyl group.

Example 3 A polycarboxylic acid was obtained in the same manner as in Example 1 except that glucose was used instead of acidolisis lignin.
It was confirmed by IR spectrum that the structure contained an ester group and a carboxyl group.

Example 4 In Example 1, instead of acidolisis lignin,
A polycarboxylic acid was similarly obtained using fructose. It was confirmed by IR spectrum that the structure contained an ester group and a carboxyl group.

Example 5 A polycarboxylic acid was obtained in the same manner as in Example 1 except that sucrose was used instead of acidolisis lignin.
It was confirmed by IR spectrum that the structure contained an ester group and a carboxyl group.

Example 6 A polyvalent carboxylic acid was obtained in the same manner as in Example 1 except that molasses was used instead of acidolisis lignin. It was confirmed by IR spectrum that the structure contained an ester group and a carboxyl group.

Example 7 0.5 g of lintercellulose was immersed in water, replaced with ethylene glycol, and mixed to give 1 g of ethylene glycol.
4.8 g of succinic anhydride and dimethylaniline 5
The mixture was added dropwise and stirred at 80 ° C. for 3 hours. The infrared absorption spectrum of the resulting polyvalent carboxylic acid product shows 1740 cm
(Ester) and peaks at around 1800 cm (carboxylic acid).

Example 8 A polycarboxylic acid was obtained in the same manner as in Example 7 except that starch was used instead of linter cellulose.

Example 9 A polyvalent carboxylic acid was obtained in the same manner as in Example 7 except that chitin was used instead of linter cellulose.

Example 10 A polycarboxylic acid was obtained in the same manner as in Example 7 except that chitosan was used instead of linter cellulose.

Example 11 A polyvalent carboxylic acid was obtained in the same manner as in Example 7, except that wood flour was used instead of linter cellulose.

Example 12 A polyvalent carboxylic acid was obtained in the same manner as in Example 7 except that coffee beans were used instead of linter cellulose.

Example 13 A polyvalent carboxylic acid was obtained in the same manner as in Example 7, except that bagasse was used instead of linter cellulose.

Example 14 1 g of the lignin-based polycarboxylic acid obtained in Example 1 was mixed with 1 g of ethylene glycol diglycidyl ether.
And 80 ° C. with stirring, and 3 drops of dimethylaniline were added. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product.

Example 15 1 g of the kraft lignin-based polycarboxylic acid obtained in Example 2 was mixed with 1 g of ethylene glycol diglycidyl ether with stirring at 80 ° C., and 3 drops of dimethylaniline were added. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product.

Example 16 1 g of the glucose-based polycarboxylic acid obtained in Example 3 was mixed with ethylene glycol diglycidyl ether 1
g at 80 ° C., and 3 drops of dimethylaniline were added. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product.

Example 17 Molasses-based polycarboxylic acid 1 obtained in Example 6
g with 1 g of ethylene glycol diglycidyl ether and 8
Stir and mix at 0 ° C. and add 3 drops of dimethylaniline. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product.

Example 18 1 g of the lintercellulosic polycarboxylic acid obtained in Example 7 was mixed with 1 g of ethylene glycol diglycidyl ether with stirring at 80 ° C., and 3 drops of dimethylaniline were added. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product composite.

Example 19 Denvun polycarboxylic acid 1 obtained in Example 8
g with 1 g of ethylene glycol diglycidyl ether and 8
Stir and mix at 0 ° C. and add 3 drops of dimethylaniline. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product composite.

Example 20 1 g of the wood flour polycarboxylic acid obtained in Example 11
With 1 g of ethylene glycol diglindyl ether and 80 g
The mixture was stirred at ℃ and mixed with 3 drops of dimethylaniline. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product.

Example 21 1 g of the lignin-based polycarboxylic acid obtained in Example 1 was added to 1 g of ethylene glycol diglycidyl ether.
And mixed at 80 ° C. with stirring, and
g and 3 drops of dimethylaniline. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product composite.

Example 22 1 g of the kraft lignin-based polycarboxylic acid obtained in Example 2 was mixed with 1 g of ethylene glycol diglycidyl ether with stirring at 80 ° C., and 0.5 g of lintercellulose and 3 drops of dimethylaniline were added thereto. Was. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product composite.

Example 23 1 g of the glucose-based polycarboxylic acid obtained in Example 3 was mixed with ethylene glycol diglycidyl ether 1
g and 80 ° C with stirring and mixing, lintercellulose 0.5g
And 3 drops of dimethylaniline. Thereafter, the mixture was heated at 130 ° C. for 10 hours to obtain a cured product composite.

Example 24 Molasses-based polycarboxylic acid 1 obtained in Example 6
g and 8 g of ethylene glycol diglycidyl ether
The mixture was stirred and mixed at 0 ° C., and 0.5 g of lintercellulose and 3 drops of dimethylaniline were added. The mixture is then
The mixture was heated at 30 ° C. for 10 hours to obtain a cured product composite.

[0047]

According to the present invention, a polyvalent carboxylic acid having excellent biodegradability is provided. The reaction product obtained by reacting the polyvalent carboxylic acid with another compound is such that the polyvalent carboxylic acid portion contained therein has biodegradability, so that the polyvalent carboxylic acid portion is biodegradable from the polyvalent carboxylic acid portion. become. The epoxy resin composition containing the polyvalent carboxylic acid of the present invention can be easily cured, and the obtained cured product becomes biodegradable from the biodegradable polycarboxylic acid portion contained therein. .

 ──────────────────────────────────────────────────続 き Continuing from the front page (71) Applicant 500559514 Masahiro Funabashi 2-11-21-701 Namiki, Tsukuba, Ibaraki (72) Inventor Shigeo Hirose 1-1, Higashi, Tsukuba, Ibaraki Prefecture, National Institute of Advanced Industrial Science and Technology, METI (72) Inventor Hyoe Hatakeyama 73-8 Yatsumata, Koshino Village, Nyu-gun, Fukui Prefecture (72) Inventor Masahiro Funabashi 1-1 Higashi, Tsukuba City, Ibaraki Prefecture Laboratory F-term (reference) 4C057 BB01 BB02 CC01 DD02 HH02 4C090 AA02 BA15 BA46 BA47 BB02 BB12 BB17 BB32 BB36 BB52 BB53 BB65 BB97 BD50 CA38 DA08 DA31 4J036 AD08 AF06 AF08 AG00 AH00 AJ05 CD21 DB24

Claims (4)

[Claims] 1. A biodegradable polycarboxylic acid characterized by being formed by reacting a polycarboxylic anhydride with a polyol solution formed by dissolving a saccharide compound and / or a lignin substance in a polyol. . 2. (a) vegetable powder and / or short fiber having a hydroxy group, (b) a sugar compound and / or a lignin substance, (c) a polyol, and (d) a polyvalent carboxylic anhydride. A polyvalent carboxylic acid comprising a reaction product of 3. An epoxy resin composition comprising the polycarboxylic acid according to claim 1 or 2 and an epoxy resin. 4. An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 3.