JPS58148747A - Manufacture of esterified wood - Google Patents

Abstract

PURPOSE:To promote smooth esterifying reaction and to introduce carboxyl groups by a method wherein polybasic anhydride is reacted on a small wooden piece in aprotic polarsolvent in the presence of basic catalyst to esterify hydroxyl groups in wood. CONSTITUTION:Small wooden pieces such as wooden fibers, wooden chips, fined wood, etc. are dried. Polybasic anhydride such as maleic anhydride, succinic anhydride, etc. is dissolved in aprotic polar solvent such as dimethylamide, dimethylsulfoxide, etc. to prepare polybasic anhydride density solution of 40% or more. After basic catalyst such as dimethyl benzilic amine, pyridine etc. is dissolved in the above solution, this solution is added to the above-mentioned small pieces of wood so that the pieces are dipped and reacted. The reaction is performed at room temperature -200 deg.C. As the reaction goes on, the anhydroxy group in the wood causes esterifying reaction with polybasic anhydride to introduce carboxyl group in wooden fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for producing esterified wood having an active carboxyl group in the side chain of a molecular chain by addition in the presence of a basic catalyst in an aprotic polar solvent.

Traditional wood esterification products include acetic acid and butyric acid.

m fatty acid esters such as lauric acid, stearic acid, and oleic acid are known. Among them, lower fatty acids are obtained by reacting acid anhydrides in the presence of a catalyst, but higher fatty acids are difficult to synthesize using acid anhydrides, so acid chlorides are reacted in the presence of a catalyst. method is known. However, since the side chain of the esterified product 1d, which is obtained by adding a monocarboxylic acid to the hydroxyl group in these woods, is an alkyl group with no reactivity, further cross-linking cannot be made and there is no development potential. Ta. Reactions with polybasic acid anhydrides, in which the side chains of the molecular chains become active carboxyl groups, have so far been observed in cellulose. It is known to react in the presence of a catalyst to obtain a half-esterified product.

On the other hand, wood has a skeleton made of a laminate of crystalline cellulose structural units, microfibrils, and non-quality substances such as lignin and hemicellulose are interposed in the spaces between them, so the problem is that the reaction rarely progresses compared to cellulose alone. .

The present inventors conducted extensive research to solve the above-mentioned problems, and found that when a small piece of wood is reacted with a polybasic acid anhydride, the reaction occurs in the presence of a basic catalyst in an aprotic polar solvent. They discovered that the esterification reaction proceeds smoothly and that the polybasic acid anhydride exhibits a high addition rate to the ice phase, leading to the present invention.

That is, the present invention is characterized in that carboxyl groups are introduced into small pieces of wood by reacting a multi-warm acid anhydride in an aprotic, polar solvent in the presence of a basic catalyst to esterify the hydroxyl groups in the wood. The present invention provides a method for producing ester toppings.

The types of small pieces of wood used in the present invention include kigui ryoken, kiku sentsubu, tetsu 7-classified kimatsu tatami, raw wood, and kin 1 tatami.
God has no special restrictions on rt. It is preferable that the wood pieces are subjected to a drying process depending on the chemicals used.

The 17'N (polybasic acid p)HIH hydrate used in the present invention is a polyhydric carboxylic acid anhydride, and specifically, maleic anhydride, co-phosphoric anhydride, y16-hydrophthalic acid, and tetrahydrohydrohydride anhydride. Phthalic acid, hexahydrophthalic anhydride, itaconic anhydride, hetaconic anhydride, tetrabromophthalic anhydride1.
IW, pyromellitic anhydride, etc. The amount of these to be used in the dried wood chips is preferably in the range of 50 to 500 layers per 100 layers of the wood grain.

The non-norotonic polar solvents used in the present invention are N-methylformamide, dimethyl-sulfoquine, N-methyl-2
-pyrrolidone, dimethylacetamide, etc., which are solvents that swell wood considerably more than water. The amount of these solvents used is 1.00% of the dry-treated wood piece.
A range of 50 to 1 o o o *ionization based on parts by weight is suitable.

The basic catalysts used in the present invention are dimethylbenzylamine, pyridine, and dimethylaniline.

Examples include alkali metal oxides, hydroxides, carbonates, acetates, and the like. In particular, dimethylbenzylamine is used when reacting at a high temperature of 1.30°C or higher.

Since pyridine and the like cause a photothermal reaction in an aprotic polar solvent, alkali metal oxides, hydroxides, carbonates, and acetates are preferred; for example, sodium carbonate is preferred. The use of these catalysts is 0 per 100 parts by weight of wood chips.
A range of 1 to 10 parts by weight is preferred.

To explain Yuko Kinoe's Shunzukuri method step by step, it is preferable to remove as much moisture as possible from the wood pieces by drying them using a vacuum dryer, hot air dryer, or the like.

If a large amount of water remains in the aqueous phase, this water will react with the polybasic acid anhydride to produce polyhydric carboxylic acid as a by-product, which is undesirable. A polybasic acid anhydride is dissolved in an aprotic polar solvent. In this case, the concentration of polybasic acid anhydride is 40
% or more is preferable. A dilute solution of VC of 40% or less is undesirable because the addition rate of the polybasic acid anhydride to the wood chips becomes small.

Next, 01 to 10 parts by weight of a basic catalyst is added to the solution described in "-" based on 10 parts by weight of small pieces of wood and dissolved therein. When an alkali metal compound such as sodium carbonate is used as a basic catalyst, it may not dissolve in an aprotic polar solvent, and in this case it must be uniformly dispersed in the solution.

The solution thus obtained is added to the wood chips, for example wood fibers, and allowed to penetrate. The amount of solution to the aqueous phase fibers is sufficient so that the aqueous phase fibers can be uniformly wetted or dipped once grown, and it is not economical to use a large amount of the solution. The reaction is usually carried out under heating and by stirring the system. Although the reaction proceeds in a heterogeneous system throughout, it is preferable to occasionally stir the mixture at high speed to loosen the wood fibers in order to make the reaction system homogeneous.

As the reaction progresses, the hydroxyl groups in the wood undergo an esterification reaction with the polybasic acid anhydride, and carboxyl groups are introduced into the wood W and fibers.The addition rate of the polybasic acid anhydride to the aqueous phase fiber depends on the reaction The reaction temperature varies depending on the temperature, reaction time, amount of polybasic acid anhydride added to the wood fibers, etc.
(10°C, good temperature is 80°C to 140°C. Reaction time is 05 to 15 hours, preferably 2 to 6 hours. Addition of polybasic acid anhydride to wood fibers 1' Preferably, the amount is 1 to 5 times the weight of the wood fiber.After the reaction, take out the esterified product and thoroughly wash it with acetone.If the catalyst does not dissolve in acetone, such as sodium carbonate or lithium carbonate, wash with water. are carried out at the same time.After washing, the esterified wood fibers are obtained by drying in a vacuum dryer and a hot air dryer.The addition rate of polybasic acid anhydride to the wood +;lW fibers of this esterified wood fiber is surprising. The addition rate is generally as high as 20 to 60%.

Here, the addition rate d of the polybasic acid anhydride to the end ww can be measured by the jusai method or the alkali saponification method. When the esterified aqueous phase fiber is measured using an infrared absorption spectrum, the absorption of carboxyl groups is clearly observed. This esterified wood fiber has an active carboxyl group in the side chain of its molecular chain, and can be used as plasticized wood and in the development of various new uses.

The objects of the present invention are achieved by simultaneously using an aprotic polar solvent and a basic catalyst during the reaction.

Solvents other than aprotic polar solvents used in the present invention,
For example, even if a solvent such as acetone, benzene, toluene, xylene, cyogysan, methyl ethyl ketone, hexane, etc. is used in place of the aprotic polar solvent of the present invention and the reaction is performed, the addition of polybasic acid anhydride ( -I can hardly see the annotations.

In fact, even if the above-mentioned solvents are used in combination with aprotic polar solvents, the addition of polybasic acid anhydrides to small pieces of wood is highly unlikely and undesirable. Even if an acid catalyst such as sulfuric acid, peroxylic acid, hydrochloric acid gas, phosphoric acid, etc. is used instead of the basic catalyst used in the present invention, the polybasic acid anhydride on the wood particles April sword■ rate is small and cannot reach the point of industrial use.

In the present invention, an esterified aqueous phase in which carboxyl groups are introduced into molecular chains in wood by reacting a polybasic acid anhydride with a small piece of wood in an aprotic polar solvent in the presence of a basic catalyst, such as anhydrous tetrahydrocarbon Esterified wood to which phthalic acid has been added has significant hygroscopicity (C), and when made into a board, its dimensional stability is greatly improved.

In this way, it retains the characteristics of the wood grain itself, and reveals properties that it did not originally have.

Its uses are wide-ranging, such as strong boards and plastic anchorage.

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Example] 11 40y of dried wood fibers (fiber size: 24 meters passed, 60 meters fraction) were placed in a separable flask.
put in. Next, anhydrous maleic #120y, dimethyl sulfoxide 1.2 (JP).

Add dimethylbenzylamine 08y and let it penetrate into the wood fibers. Next, the mixture was stirred and reacted at a reaction temperature of 8f1°C and a reaction time of 3 hours. Although the reaction was carried out in a heterogeneous system throughout, the wood fibers were occasionally stirred at high speed to loosen the wood fibers so that the reaction proceeded in a homogeneous state. After the reaction, the esterified product was taken out, thoroughly washed with acetic acid, and then dried in a vacuum dryer and a hot air dryer to obtain the esterified wood fiber of the present invention.

Example 2 Dried wood fibers (fiber size passed through 24 mesh, 60 mesh fraction) were placed in a 1 t separable flask.
I) Enter y. Next, phthalic anhydride], 80y, dimethylformamide 1.80! , pyridine 0.8
Add ff and wood #1. Penetrate into the blood vessels.

Next, reaction temperature] 00'C, reaction time 1 - (13 hours) The reaction was carried out with stirring.The reaction was carried out in a heterogeneous system from beginning to end, but high-speed stirring was occasionally carried out to ensure that the reaction proceeded in a homogeneous state. After the reaction, the esterified product was taken out, thoroughly washed with acetone, and then dried in a vacuum dryer with hot air.
The esterified wood fiber of the present invention was prepared by drying with &J.

Example 3 Put 4()y of dried wood fibers (fiber size: 24,
Add 12 y of dimethylformamide, 1 y of charcoal, and 0.8 y of thorium to penetrate into the wood fibers. Next, the mixture was stirred and reacted at a reaction temperature of 110° C. and a reaction time of 3 hours. Although the reaction was carried out in a heterogeneous system from start to finish, the wood fibers were occasionally stirred at high speed to loosen the wood fibers so that the reaction proceeded in a homogeneous state.

After the reaction, the esterified product was spun out, thoroughly washed with acetone, and then washed with water. Next, the esterified wood fibers of the present invention were obtained by drying with a vacuum dryer and a hot air dryer.

Comparative Example 1 An esterification reaction was attempted using the same recipe as in Example 1 except that dioxane was used instead of dimethyl sulfoxide, which was the reaction solvent described in Example 1.

Comparative Example 2 Example 2 was carried out using methyl ethyl ketone instead of dimethylformamide, which is the reaction solvent described in Example 2.
Let's try an esterification reaction using the same recipe.

Comparative Example 3 An esterification reaction was attempted using the same recipe as in Example 3, using sulfuric acid instead of the reaction catalyst, sodium carbonate, described in Example 3.

Table 1 shows the results of measuring the weight addition ratio of polybasic acid anhydride to 10031i parts of wood fiber in the esterified wood fibers used in Examples and Comparative Examples.

As is clear from Table 1, the esterified wood fibers obtained in the Examples of the present invention are characterized by a much higher addition rate of polybasic acid anhydride than in the Comparative Examples.

Table 1

Claims (1)

[Claims] Esterification characterized by introducing carboxyl groups by reacting a polybasic acid anhydride with a small piece of wood in an aprotic polar solvent in the presence of a melon base molecule to esterify the hydroxyl groups in the wood. Wood manufacturing method.