JPH05185405A - Manufacture of chemical modified woody material having excellent thermal fluidity - Google Patents

Abstract

PURPOSE:To provide the process for manufacturing a chemical modified woody material, which has a high woody material content, has excellent thermal fluidity and can be molded under normal extrusion conditions. CONSTITUTION:In the manufacture of a chemical modified woody material having excellent thermal fluidity, a woody material and a chemical substance (such as a polybasic acid anhydride and a monoepoxy compound or the monoepoxy compound) capable of being reacted with hydroxyl groups in the woody material are reacted while making a metal halide having electronegativity of 1.0 or more except strontium or a ammonium halide coexist.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a chemically modified wood material having excellent heat fluidity which can be used as an extrusion molding material.

[0002]

2. Description of the Related Art Woody materials, which represent wood, are organic natural resources that are the most abundant in nature and have recently attracted attention as reproducible resources. However,
Since these wood materials are insoluble and infusible and do not flow or melt like ordinary thermoplastic synthetic resins, it is not easy to process them into arbitrary shapes.

Conventionally, wood materials have been used for various purposes such as construction materials by taking advantage of their excellent characteristics. However, small-diameter trees, thinned wood, sawdust, etc. discharged from wood factories are used. However, most of them are discarded by methods such as incineration, and development of effective utilization methods for these is desired.

Recently, in order to effectively utilize these promising resources, by chemically modifying the hydroxyl group in wood,
Research is being conducted to impart thermoplasticity not found in wood itself. For example, a method of allylating a wood material with an allyl halide, a method of treating a wood material with a strong alkali and then benzylating the wood material with benzyl chloride,
Method of acylating wood material using trifluoroacetic anhydride and fatty acid such as acetic acid or lauroyl acid, method of etherifying wood using epoxy compound in the presence of potassium salt of fatty acid (Japanese Patent Publication No. 3-33081) Etc. have been proposed.

Further, the present inventors have previously proposed a method for producing a modified wood piece (Japanese Patent Laid-Open No. 60-83806). This modified wood piece is obtained by alternately adding esterification reaction of dibasic acid anhydride and monoepoxy compound to the hydroxyl group in the wood piece, and it can be hot pressed and has excellent moisture resistance and water resistance. It can be a hard surfaced sheet or board.

However, the chemically modified woods obtained by these methods have thermoplasticity but poor heat flowability, and for example, 180 ° C. to 200 ° C.
It was necessary to perform thermocompression molding at a high temperature and high pressure of 00 kg / cm ² or more. On the other hand, when a large amount of chemical substances are added to the wood by the above method, the heat fluidity is slightly improved, but on the contrary, the content of the wood in the chemically modified wood obtained is low. was there.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a method for easily producing a chemically modified wood material which has a high content of wood material but is excellent in heat fluidity and can be molded under normal extrusion conditions. The purpose is to

[0008]

According to the present invention, a metal halide having a wood material and a chemical substance capable of reacting with a hydroxyl group in the wood material and having an electronegativity of 1.0 or more excluding strontium. , Or a method for producing a chemically modified wood material having excellent heat fluidity, which is characterized by reacting in the presence of ammonium halide, and a polybasic acid is used as a chemical substance capable of reacting with a hydroxyl group in the wood material. Provided is a method for producing a chemically modified wood material having excellent heat fluidity, which is characterized by using an anhydride and a monoepoxy compound, and a chemical substance capable of reacting with a hydroxyl group in the wood material is a monoepoxy compound. The method for producing a chemically modified wood material having excellent heat fluidity is provided.

That is, the present inventors have found that metal halides having an electronegativity of 1.0 or more, excluding strontium,
Alternatively, a chemically modified wood material obtained by coexisting an ammonium halide has remarkably excellent heat fluidity as compared with a chemically modified wood material produced without the presence of the metal halide or ammonium halide. The present invention has been completed and the present invention has been completed.

The method for producing the chemically modified wood material excellent in heat fluidity of the present invention will be specifically described below. The wood material used in the production of the chemically modified wood material of the present invention, wood powder, wood fiber, wood chips and particle boards, other wood pieces such as sander powder discharged during the manufacturing process of fiberboard, Examples include plant fibers such as straw, rice straw, rice husk, waste paper, linters and bagasse, other lignocellulosic materials containing cellulose or lignin as a main component, and pulverized cellulose powder or pulp. When the water content in these wood materials is high, it is preferable to use it after drying with a hot air dryer or a vacuum dryer to remove water to 15% or less. When the water content is high, a side reaction occurs when a polybasic acid anhydride or an epoxy compound is used as the chemical substance, which is not preferable.

Examples of chemical substances capable of reacting with hydroxyl groups in wood materials include well-known alkyl halides such as ethyl chloride, allyl chloride and benzyl chloride, allyl halides, aryl halides, or acetic anhydride. Examples thereof include organic acids such as maleic anhydride, phthalic anhydride, and lauric acid, or anhydrides thereof, epoxy compounds such as epichlorohydrin, phenylglycidyl ether, allylglycidyl ether, and isocyanate compounds. In particular, it is preferable to use a polybasic acid anhydride and a monoepoxy compound in combination, or a monoepoxy compound, which are simple in the manufacturing process and have few by-products, as the chemical substance.

For example, polybasic acid anhydrides include maleic anhydride, phthalic anhydride, succinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and 3.6 anhydrous.
Examples thereof include dichlorophthalic acid, itaconic anhydride, and hettic anhydride. Particularly preferred are maleic anhydride, phthalic anhydride, succinic anhydride and the like, which are industrially inexpensive and advantageous.

The monoepoxy compound may be a compound containing one epoxy group in the molecule, and examples thereof include phenyl glycidyl ether, allyl glycidyl ether, styrene oxide, octylene oxide,
Methyl glycidyl ether, butyl glycidyl ether, cresyl glycidyl ether, epichlorohydrin, etc. are mentioned.

Examples of the halogen compound of a metal having an electronegativity of 1.0 or more excluding strontium or ammonium halide used in the present invention include magnesium chloride hexahydrate, calcium chloride, lithium chloride, and chloride. Examples thereof include cobalt, magnesium chloride, ammonium chloride, magnesium bromide hexahydrate, zinc chloride and the like. Particularly, magnesium chloride hexahydrate, calcium chloride and the like, which are industrially inexpensive and advantageous, are preferable. When a metal halide having an electronegativity of less than 1.0 is used, or when a strontium halide or an inorganic salt other than a halide is used, chemical modification with excellent heat fluidity as in the present invention is performed. You cannot get wood.

The amount of the metal halide or ammonium halide added is preferably 1.0 part by weight or more based on 100 parts by weight of the wood material. If the addition amount is less than 1.0 part by weight, the heat fluidity of the obtained chemically modified wood material is poor and, for example, it is impossible to measure the melt index (MI) which is one index of the heat fluidity. It is not preferable because it exists.

In the production method of the present invention, dimethylacetamide, N, which is a well-known solvent, has been used.
-Methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide and the like, potassium acetate as a catalyst,
It is safe to use dimethylbenzylamine together. However, in particular, it is preferable to carry out without solvent and without catalyst because the production process is simple and there are few by-products.

As an example thereof, a case where a polybasic acid anhydride and a monoepoxy compound are used as the chemical substances capable of reacting with the hydroxyl groups in the wood material will be described. The total amount of the polybasic acid anhydride and the monoepoxy compound used is preferably 15 to 250 parts by weight based on 100 parts by weight of the wood material. When the amount used is less than 15 parts by weight, the thermoplastic wood material composition obtained has poor thermal fluidity, and the melt index (MI) cannot be measured. Conversely, the amount used is 25
If the amount exceeds 0 parts by weight, a wood material composition having excellent heat fluidity can be obtained, but the wood material content becomes too low, which not only defeats the purpose of the present invention but is also economically undesirable.

The amount of the polybasic acid anhydride used is preferably 1.5 equivalents or less of the non-hydroxyl group in the polybasic acid anhydride with respect to 1 equivalent of the epoxy group of the monoepoxy compound. If the polybasic acid anhydride has more hydroxyl groups than this, the number of half-esters of the polybasic acid anhydride having a carboxyl group added to the hydroxyl group in wood at the end increases, and the resulting woody material composition It is not preferable because the water resistance is lowered.

The reaction temperature for reacting a wood material with a polybasic acid anhydride or a monoepoxy compound in the presence of a metal halide or ammonium halide is generally
It easily progresses at 60 ° C or higher, but especially 90 ° C to 200 ° C.
Is preferred. Further, as the reaction method, wood materials, monoepoxy compounds, polybasic acid anhydrides and halides or ammonium halides of the metals are put into a reaction vessel at a time to react, or wood materials and monoepoxy compounds and the metals A mixture of a halide or an ammonium halide is heated and stirred for 10 minutes to 5 hours in advance, and then a polybasic acid anhydride is added and reacted, or a wood material, a polybasic acid anhydride and a halide of the above metal,
Alternatively, there may be mentioned a method in which a mixture of ammonium halides is heated and stirred for 10 minutes to 5 hours in advance, and then a monoepoxy compound is added and reacted, but any method may be used.

This reaction proceeds sufficiently even without using a catalyst, but sodium carbonate, in order to accelerate the reaction,
Ordinary addition esterification catalysts such as dimethylbenzylamine, pyridine and tetramethylammonium chloride may be used.

Next, as another example of the present invention, a case where a monoepoxy compound is used as a chemical substance capable of reacting with a hydroxyl group in a wood material will be described. The reaction is wood,
The monoepoxy compound and the metal halide or ammonium halide are put into a reaction vessel all at once, and the reaction temperature is 60 ° C. or higher, preferably 90 ° C. to 200 ° C. The amount of the monoepoxy compound used is preferably 15 to 250 parts by weight based on 100 parts by weight of the wood material.
When the amount used is less than 15 parts by weight, the thermoplastic chemically modified wood material obtained has poor thermal fluidity, and the melt index (MI) cannot be measured. Conversely, the amount used is 25
If it exceeds 0 parts by weight, a chemically modified wood material having excellent heat fluidity can be obtained, but the wood material content becomes too low,
Not only is this contrary to the object of the present invention, it is also economically unfavorable.

This reaction proceeds sufficiently even without using a catalyst, but a usual etherification catalyst such as potassium acetate, dimethylbenzylamine, or imidazoles can be used to accelerate the reaction.

When a polybasic acid anhydride and a monoepoxy compound are used as the chemical substances capable of reacting with the hydroxyl groups in the above wood material, the polybasic acid anhydride and the monoepoxy compound alternate with the hydroxyl groups in the wood material. When the monoepoxy compound is used as an esterification product, the monoepoxy compound is added to the hydroxyl groups in the wood material. At that time, some by-products that are not bonded to the wood material are also generated. After completion of the reaction, the reaction product thus obtained is washed with water or other solvent to remove side reaction products, unreacted products, halides of the metal, ammonium halides, etc. The wood material can be used as a chemically modified wood material, but can also be used as it is without undergoing a washing treatment. In particular, when it is used as it is as a chemically modified wood material without being subjected to a washing treatment, a washing step is unnecessary, which is industrially advantageous.

The chemically modified wood material obtained by the production method of the present invention can be processed by general press molding as well as extrusion molding, injection molding or the like under ordinary processing conditions for molding thermoplastic resin. it can. In addition, before molding, the mixture can be uniformly kneaded using a kneader such as a blender, a kneader, a mixing roll, a Henschel mixer, a Banbury mixer, and then molded by the above-described molding method. The molded product thus obtained is suitable as an industrial part material, a building material and the like in many fields.

[Action]

The heat fluidity of the chemically modified wood material obtained by the production method of the present invention is remarkably superior to that of the chemically modified wood material obtained by the conventional production method. A metal halide having an electronegativity of 1.0 or more excluding strontium to be coexistent in the reaction system,
Or the collapse of the crystals of cellulose present in the chemically modified wood obtained by the action of ammonium halides,
It is also presumed that the crystallinity was drastically reduced. As a result of X-ray diffraction as shown in FIG.
This is also supported by the fact that the peak at 2θ = 22.8 °, which is based on cellulose crystals, disappears or is greatly reduced compared to the original wood material.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
In the present invention, wood powder (trade name: LIGN) is used as the wood material.
OCEL S150TR; Rettenmarie
r &Soehne; fiber length: 30-60 μ)
Was used. The wood powder ratio of the obtained chemically modified wood material was calculated from the weight (M) of the wood powder and the weight (N) of the reactant by the following formula. Wood flour ratio (%) = 100M / (M + N)

The anhydride acid value showing the reaction rate of the polybasic acid anhydride was determined from the difference between the aqueous acid value and the non-aqueous acid value. The measuring method is as follows. Aqueous acid value: About 0.2 g of a precisely weighed sample is added to 30 ml of acetone.
Disperse in a mixed solvent of 10 ml of deionized water and
After leaving it in the room for 0 minutes, it was determined from the value obtained by titrating with 0.1N KOH aqueous solution. Non-aqueous acid value: About 0.2 g of a precisely weighed sample is added to 30 m of acetone.
It was determined from the value obtained by titrating with 0.1 NKOH-methanol after dispersion in 1.

The epoxy value indicating the reaction rate of the monoepoxy compound was 0.1N HBr-in about 0.2 g of a precisely weighed sample.
After adding 7 ml of acetic acid solution and leaving it in the room for 20 minutes,
10 ml of 0.1N phenylglycidyl ether-chlorobenzene solution was added, and the mixture was allowed to stand in the room for 20 minutes, and then determined from a value titrated with 0.1N HBr-acetic acid solution.

The acetone-soluble portion means a side reaction product that is not bound to the wood material component and a chemically modified wood material that has become soluble in acetone. The weight (X) of the sample and the acetone Weight eluted by Soxhlet extraction (Y),
And the total weight (Z) of the unreacted monoepoxy compound and the polybasic acid anhydride, it was determined by the following formula. Acetone soluble part (% by weight) = 100 (YZ) / X

The thermal fluidity of the chemically modified wood material obtained was evaluated by the melt index (MI). Melt index (MI) is 150 according to JIS K7210.
℃, sample load 10kg, or 190 ℃, sample 10k
It was determined from the value measured in g.

Example 1 15 g of air-dried wood powder (water content 8%), styrene oxide 1
Charge 5.89 g and 4.0 g of lithium chloride into a 500 ml separable flask and stir at 150 ° C. for 2 hours.
6.62 g of succinic anhydride was added, and the mixture was further reacted at 150 ° C. for 5 hours with stirring. The anhydrous acid value, the epoxy value, and the weight% of the acetone-soluble portion obtained by Soxhlet extraction are shown in Table 1. Take a part of this reaction product, wash with a large amount of water,
After removing lithium chloride, it was dried to obtain a chemically modified wood material (1A) and an unwashed chemically modified wood material (1B). Table 1 shows the MI values of these chemically modified wood materials 1A and 1B.

Examples 2 to 5 Examples 1 to 5 except that dry wood powder was used instead of air-dried wood powder, and 4.0 g of the above-mentioned metal chloride or ammonium chloride shown in Table 1 was used instead of lithium chloride. Similarly, a chemically modified wood material was obtained. Table 1 shows the anhydride acid value, the epoxy value, the weight% of the acetone-soluble portion obtained by the Solekkuslet extraction, and the MI value of this chemically modified wood material.

Comparative Example 1 A chemically modified wood material was obtained in the same manner as in Example 1 except that 4.0 g of sodium chloride was used instead of the metal halide or ammonium halide. Table 1 shows the anhydride acid value, epoxy value, weight% of the acetone-soluble portion by Soxhlet extraction, and MI value of this chemically modified wood material.

Comparative Example 2 A chemically modified wood material was obtained in the same manner as in Example 1 except that 4.0 g of strontium chloride was used instead of the metal halide or ammonium halide. Table 1 shows the anhydride acid value, epoxy value, weight% of the acetone-soluble portion by Soxhlet extraction, and MI value of this chemically modified wood material.

Comparative Example 3 A chemically modified wood material was obtained in the same manner as in Example 1 except that the metal halide or ammonium halide was not used. Table 1 shows the anhydride acid value, epoxy value, weight% of the acetone-soluble portion by Soxhlet extraction, and MI value of this chemically modified wood material.

Example 6, Comparative Examples 3 to 5 As Example 1 except that the above-mentioned metal halides or ammonium halides or other metal salts (hereinafter referred to as inorganic salts) were used. Similarly, a chemically modified wood material of the present invention and a comparative chemically modified wood material were obtained. Anhydrous acid value, epoxy value, weight% of acetone soluble part by Soxhlet extraction of these chemically modified wood materials,
The values of and MI are shown in Table 2.

[0038]

[Table 2]

Example 7 26.3 g of air-dried wood powder (water content 8%), 7.91 g of styrene oxide and 7.01 g of lithium chloride were placed in a 500 ml separable flask and stirred at 150 ° C. for 2 hours.
3.29 g of succinic anhydride was added, and the mixture was further reacted at 150 ° C. for 5 hours with stirring to obtain a chemically modified wood material of the present invention having a wood flour content of 70%. Anhydrous acid number of this chemically modified wood material,
Table 3 shows the epoxy value, the weight percentage of the acetone-soluble portion obtained by Soxhlet extraction, and the MI value.

Example 8 30.0 g of air-dried wood powder (water content 8%), 5.29 g of styrene oxide and 8 g of lithium chloride were placed in a 500 ml separable flask and stirred at 150 ° C. for 2 hours, and then succinic anhydride 2. 21 g was added, and the mixture was further reacted at 150 ° C. for 5 hours with stirring to obtain a chemically modified wood material of the present invention having a wood flour content of 80%. Table 3 shows the anhydride acid value, the epoxy value, the weight% of the acetone-soluble portion by Soxhlet extraction, and the MI value of this chemically modified wood material.

Example 9 26.3 g of dried wood flour, 7.91 g of styrene oxide,
14.97 g of magnesium chloride hexahydrate was placed in a 500 ml separable flask and stirred at 150 ° C. for 2 hours,
3.29 g of succinic anhydride was added, and the mixture was further reacted at 150 ° C. for 5 hours with stirring to obtain a chemically modified wood material of the present invention having a wood flour content of 70%. Anhydrous acid number of this chemically modified wood material,
Table 3 shows the epoxy value, the weight percentage of the acetone-soluble portion obtained by Soxhlet extraction, and the MI value.

[0042]

[Table 3]

Example 10 500 ml of 22.5 g of air-dried wood powder (water content 8%), 10.43 g of allyl glycidyl ether and 6 g of lithium chloride
The mixture was placed in a separable flask and stirred at 150 ° C. for 2 hours, 4.57 g of succinic anhydride was added, and the mixture was further reacted at 150 ° C. for 5 hours with stirring to obtain a chemically modified wood material of the present invention. Table 4 shows the anhydride acid value, epoxy value, weight% of the acetone-soluble portion by Soxhlet extraction, and MI value of this chemically modified wood material.

Example 11 22.5 g of air-dried wood powder (water content 8%), 11.25 g of phenyl glycidyl ether and 6 g of lithium chloride were added to 500 m.
The mixture was placed in a 1-separable flask, stirred at 150 ° C. for 2 hours, added with 3.75 g of succinic anhydride, and further reacted at 150 ° C. for 5 hours with stirring to obtain the chemically modified wood material of the present invention. Table 4 shows the anhydride acid value, epoxy value, weight% of the acetone-soluble portion by Soxhlet extraction, and MI value of this chemically modified wood material.

Example 12 22.5 g of air-dried wood powder (water content 8%), 9.28 g of styrene oxide and 6 g of lithium chloride were placed in a 500 ml separable flask and stirred at 150 ° C. for 2 hours, and then phthalic anhydride was mixed with 5. 72 g was added, and the mixture was further reacted at 150 ° C. for 5 hours with stirring to obtain a chemically modified wood material of the present invention. Table 4 shows the anhydride acid value, epoxy value, weight% of the acetone-soluble portion by Soxhlet extraction, and MI value of this chemically modified wood material.

Example 13 22.5 g of dry wood flour, 10.65 of styrene oxide
g, magnesium chloride hexahydrate 12.81 g 500 m
A 1-separable flask was charged, and the mixture was stirred at 150 ° C for 2 hours, then 4.35 g of maleic anhydride was added, and further 150 ° C
And reacted for 5 hours under stirring to obtain the chemically modified wood material of the present invention. Anhydrous acid value, epoxy value,
Table 4 shows the weight% of the acetone-soluble portion by Soxhlet extraction and the value of MI.

Example 14 75 g of dry wood powder, 79.42 g of styrene oxide and 20.0 g of lithium chloride as an inorganic salt were charged in a 51 separable flask and reacted at 150 ° C. for 5 hours under stirring to chemically modify the composition of the present invention. I got wood. Table 4 shows the epoxy value, the weight% of the acetone-soluble portion by Soxhlet extraction, and the MI value of this chemically modified wood material.

[0049]

Industrial Applicability As described above, the chemically modified wood material obtained by the production method of the present invention has remarkably improved thermal fluidity as compared with the conventional chemically modified wood material. Of course, because it can be processed by ordinary molding methods such as extrusion molding and injection molding, it can further expand the field of use of wood-based materials and is not only industrially useful, it is also a by-product from small-diameter trees, thinned wood, and the wood industry. Small pieces of wood, wood powder, etc. can also be used and are extremely useful from the viewpoint of effective use of these. The present invention also has an advantage that it can be used as a molding material after the reaction without particular washing and purification.

[0050]

[Brief description of drawings]

1] X-ray diffraction diagram of chemically modified wood material a) Chemically modified wood material obtained in Example 2 b) Chemically modified wood material obtained in Comparative Example 3

Claims (3)

[Claims] 1. A reaction between a wood material and a chemical substance capable of reacting with a hydroxyl group in the wood material in the coexistence of a metal halide having an electronegativity of 1.0 or more excluding strontium, or an ammonium halide. A method for producing a chemically modified wood material having excellent heat fluidity, which comprises: 2. A chemically modified wood material having excellent heat fluidity according to claim 1, wherein a polybasic acid anhydride and a monoepoxy compound are used as the chemical substances capable of reacting with the hydroxyl groups in the wood material. Method of manufacturing wood. 3. The method for producing a chemically modified wood material excellent in heat fluidity according to claim 1, wherein the chemical substance capable of reacting with a hydroxyl group in the wood material is a monoepoxy compound.