JPS58118801A - Extraordinarily hygroscopic cellulose derivative - Google Patents

Abstract

PURPOSE:The titled derivative capable of absorbing a large quantity of water and suitable as, for example, a material for absorbing body fluids and blood, comorising a cellulose derivative having specified hydrophobic groups in a degree of substitution of above 2.0 and specified anionic groups in a degree of substitution of below 0.4. CONSTITUTION:An extraordinarily hygroscopic cellulose derivative capable of forming a hydrogel, in which the degree of substitution of hydrophobic groups free of a carboxyl, sulfo, tert. amino or hydrocarbyl group (e.g., a group of formulaI, wherein R is an alkyl or an aromatic, a group of formula II, wherein x>=1, and groups of formula III and IV, wherein R is an aromatic or a 2C or higher alkyl) is above 2.0, and the degree of substitution of anionic groups containing a carboxyl group, a sulfo group or salts thereof (e.g., carboxymethyl, carboxyethyl or sulfo group) is below 0.4. This derivative can absorb water in an amount of at least 50 times its weight, can be used as a material for absorbing body fluids or bloods, and can form a hydrogel, so that it has an ability of capturing bacteria, etc., within the gel or an ability of fractionating water- soluble matter.

Description

[Detailed description of the invention] The present invention relates to superhygroscopic cellulose cast conductors.

More particularly, the present invention relates to a novel cellulose derivative capable of absorbing 50 times or more of its own weight in water. The purpose of the present invention is to absorb industrial water, saline water, and blood extremely well, and to form an aqueous gel.
The purpose of the present invention is to provide a novel cellulose derivative that can separate solid and water-soluble substances.

The cellulose derivatives used as super hygroscopic materials are limited to partially cross-linked derivatives with water-dispersible properties such as carboxy7-methylcellulose, carboxyethylcellulose, hydroxyethylcellulose, and hydroxypropyl by some means. ing.

On the other hand, from the viewpoint of good water absorption, the above purpose can also be achieved by making the structure of cellulose itself more amorphous by physical or chemical methods. Also, cellulose chemistry! ! ! '.

Those in the know know that all cellulose derivatives with an extremely low degree of substitution, for example, 0.4 or less, are soluble in alkali and are difficult to swell in water to some extent. In addition, even if the substituents of cellulose derivatives are hydrophobic, some derivatives are soluble in water at the degree of substitution at the 0,4-0.9 positions, so if they are crosslinked by some means, they can become highly absorbent. It is easy to analogize what can be done with synthetic materials. The degree of substitution here refers to the average number of substituents contained per glucose unit when the hydrogens of the three θB groups at positions 2, 3, and 6 of the glucose unit constituting the cellulose molecule are replaced with other groups. . The fact that cellulose derivatives with the above-mentioned substitution degree range (0.9 or higher) has an extremely strong affinity for water means that if the substituent of the derivative is hydrophobic, the cellulose derivative has a unique affinity with the cellulose molecule. The point is that the hydrophilic OH groups inside serve as effective water absorption sites. That is, by introducing the substituent, the hydrogen bonds between the θHJP ring oxygens that originally exist in the cellulose molecule are broken, and the remaining OH groups are made more free. This indicates that, since such derivatives have a strong interaction with water, an average of 21 or more remaining OH groups per glucose unit is required.

Therefore, if the degree of substitution of the hydrophobic group is 2.0 or more, there will be no affinity for water at all. In the method of making cellulose into a hygroscopic material by changing its molecular structure or converting it into a derivative with a degree of substitution of 0.4 or more,
It is impossible to absorb 0 times more water. In addition, cellulose derivatives having ionic substituents, especially highly substituted ones, and cellulose derivatives having a degree of substitution with hydrophobic substituents of 0, 4 to 0.9, as described above, can be used without one frame IIl. .

It is impossible to obtain a material that strongly absorbs water and is completely insoluble in water.

As a result of a thorough investigation from the perspective of the thermodynamic interaction between the chain and water, we found that it was indeed the right thing to do.

The present invention was achieved by discovering a derivative having a degree of substitution of a hydrophobic substituent of 20 or more, that is, a derivative that can absorb 50 times its own weight of water even though it has conventionally had no affinity for water.

321J, the present invention is a carboxyl group, a sulfonic acid group.

The degree of substitution of hydrophobic groups that do not include tertiary amino groups or hydroxyl groups is 2.
．． 0 or more and anionic groups containing carboxyl groups or sulfonic acid groups and salts thereof [conversion degree is 0.4 or more], and is a cellulose fermentation conductor that forms an aqueous gel.

The hydrophobic substituent used in the present invention is a substituent that has two or more ee chains and is bonded to cellulose in the form of an ester or ether.

tic group) -(C)IJX-Cps (x≧1),
-cn, ca, cN.

1-c-Na-h (kt: aromatech, C2 or higher alkyl &).

For example, cellulose acetate, cellulose pyrovionate, cellulose butyrate, mixed esters thereof,
Higher fatty acid ester of cellulose.

Refers to substituent 4 found in cellulose phthalate, cellulose phthalate acetate, ethyl cellulose, higher alkyl ethers of cellulose, cyanoethyl cellulose, and the reaction product of each glaze monoincyanate and cellulose.

On the other hand, the anionic substituent is -(CH,) C0OH
-so, h refers to a t Hongki containing -COOH, -80,)i group and its salt. Preferred are carboxymethyl groups and carboxyether groups that can easily be attached to the cellulose skeleton.

Sulfonic acid groups are used. As a result of studies by the inventors,
Generally, the aforementioned derivatives having hydrophobic substituents are also polarized within the molecule from a local viewpoint of the molecule. When such hydrophobic groups have a degree of substitution of 20 or more.

In the solid state, substituents or substituents and residual OH groups probably interact at the intramolecular level, and in such a state, the substituents replace most of the hydrophobicity in the electrolyte with the electronic form. It is dynamically stable and is no longer sensitive to external water attacks.

However, it became clear that the situation would change if a small portion of the remaining 0) group was replaced by an ionic substituent.

This situation will be explained regarding cellulose sulfate, which is an example of the present invention.

111 is a stable intermolecular scale ♂5 interaction, so this is H
A state that acts as a barrier against lo. t2J repels the acetyl group due to the presence of anionic groups, creating a gap between the molecules that encapsulate a and o4, and at the same time makes the acetyl group more ionic, making it extremely easy to approach the H,00 molecule, resulting in a large amount of H, This shows that it can attract O and thus form an aqueous gel. (21 shows the pattern at the intramolecular level, but of course it is thought that it also occurs between one molecule, and for this reason,
It is believed that the novel cellulose derivatives of the present invention absorb water very well. Comparing the novel cellulose aggregates of the present invention with ionic cellulose conductors with a degree of substitution of 0.4 or more, the interaction space occupied between hydrophobic substituents in the former is OH groups in the latter. It's the interaction space occupied by the bases.

The former has a stronger ability to embrace water (it is clear that this hypothesis is superior to some extent). This is also supported by the fact that the *a cellulose derivative of the invention has a smaller effect of conjugating water than other cellulose derivatives of the invention.

The cellulose derivative of the present invention can be produced by Yuzu's method.

The cellulose used in the present invention may be made from wood pulp, cotton linters, etc. as is, or may be mechanically pulverized and pretreated with friends, amide, 7+ amides, etc.
Any type of cellulose, such as cellulose with a large amorphous portion treated with phosphoric acid or the like, may be used. The degree of 1 degree is not particularly limited either, but a value of 100 or more is usually used. It can also be obtained by synthesizing in advance a cellulose I conductor having hydrophobicity 1111s by a conventional method and reacting it with a reactant that gives ionic properties. Of course,
The opposite is also possible.

On the other hand, it is also possible to simultaneously introduce a reactant that gives a hydrophobic 111 chain and a reactant that gives an ionic chain into cellulose.
” It is Noh. For example, one cotton linter treated with dimethylformamide (degree of polymerization 100.0) is dispersed in acetic acid in the presence of dimethylformamide (DMF), and then reacted with anhydrous vinegar, concentrated sulfuric acid, or DMI':/, bay complex. The cellulose acetate sulfate of the present invention can be obtained using the same method, and cellulose cyanoethylate rupoxymethylate can be obtained by treating alkali cellulose with monochloroacetic acid on acrylonitrile.

The superabsorbent conductor for cellulose of the present invention obtained as described above absorbs 50 times or more of its own weight of water.

It can be used as an absorbent for body fluids and blood ridges, and if it can form an aqueous gel, it can be used in a wide range of applications such as gel explosive carriers, emulsion/stabilizers, thickeners, mt body trapping agents, and water-bathable polymer fractionation carriers. Special period available.

The present invention will be illustrated in Examples.

Example 1 High α Cellulose Pal 7 (DP-1OQO manufactured by Leonia)
) 1001 to dimethylformamide (DMF”) 40
After dispersing in 1 and stirring for 30 minutes, excess DMF was squeezed out and 1
One piece of cake weighing 200 tons was obtained. This cake at 1600C
After dispersing C in acetic acid water, acetic anhydride 380 C (: and DM
Add 60cc of F/80° complex (21 molar ratio),
After being left for 2 days at 0.degree. C., the temperature was raised to 40.degree. C., and after 3 hours a transparent liquid was obtained L0. This bath solution rapidly absorbed water and became a gel with extremely low crystallinity. This solution was diluted with water and DMF sequentially.

The acetic acid was removed and dried under vacuum to obtain white flakes. After deacetylating this product with an alkali and quantifying the amount of bound acetic acid by neutralization titration, the deacetylated product was further boiled in salt solution, the amount of bound sulfuric acid was determined as kebarium salt, and when the degree of substitution was converted, it was found that hydrophobic acetyl substitution The degree of substitution was 262, and the degree of hydrophilic sulfuric acid substitution was 0.23. The flakes obtained above absorbed and retained 200 times their own weight in water and 160 times their own weight in physiological saline. Of course, this stuff is soluble in acetone.

Middle example 2 Suyter 100j41k1 adjusted to D P = 600
% Caustic Soda Water #! After immersing it in the liquid, it was pressed into a 250i cake. To this was added 300 g of a bath solution of 1 monochlor 1rIit11 aged at 5% linearity in an inproper tool, and after reaction at 60° C. for 5 hours, the solvent was distilled off. The product is about 5
The mixture was poured into twice the volume of acrylonitrile, reacted at 50° C. for 4 hours, neutralized with acetic acid, and the excess acrylonitrile was poured into methanol. The gel precipitate was separated using a centrifuge and then dried under vacuum. After confirming that the obtained substance contains CN groups and CC00N groups as a result of infrared spectroscopy (JtAIR)M analysis, atomic analysis (C) of N-containing m was carried out.
So, the peOONm group content is 2.4, and the degree of cyanoethyl substitution is 2.4.
．． The number of carboxymethyl groups was 0.26. This substance was soluble in acetone and pyridine. This material 'Jl absorbs 90 times its own weight of water and is 100 times its own weight.
2.3 Water-insoluble) 100% dimethylformamide (DM
F) l 00 ) mixed with (49 mol 1 mol) complex 35
? was added and reacted at 10°C for 4 hours. When this warm solution was administered into water, a gel-like precipitate was obtained. This gel-like material is centrifuged to collect the collection layer, and then freeze-dried. This animal inhaled approximately 60 times more water and 30 times more physiological saline than 11.

The basic amount of ethyl is “MsthOd in Carboh”.
ydrateChemistry”
Edited by Elle Lystra, Academic 7 Rus (R,L,
Whjster Academic Pres's, 19
According to p307 of 63 N, the sulfate group was determined to be 0 according to the method described in Example 1. As a result, the obtained product had a degree of ethyl substitution of 22° and a degree of sulfuric acid substitution of 0.17.

Comparative Example 1 In implementation flI3, DMF/80. The amount of complex is 200)
The others were reacted under the same reaction conditions. The degree of ethyl substitution of the obtained product was 2.1', and the degree of sulfuric acid 11 substitution was 0.76.
However, it is completely soluble in water and cannot retain its shape.

Comparative Example 2 Commercially available cellulose acetate (Eastman 1) 100) with a degree of substitution of 24 was converted into dimethylacetamide (DMA e )
]50? The mixture was dissolved in a bath, and 70 g of the DMF/SO3 complex was reacted at room temperature for 2 hours. The reaction solution was added to methanol, and after that, it was allowed to stand still for a long time to precipitate, and the ks fraction was collected.

The degree of acetyl substitution of this product is 1.8. Sulfuric acid i1 conversion degree is 0
．． 38, but it was completely water soluble.

As shown in the examples above, the cellulose derivative of the present invention has extremely high water absorption performance due to the combination of the degree of substitution of hydrophobic groups and hydrophilic groups (ionic groups), It can also be used in the form of a membrane + fiber or fiber in a wide variety of fields, including fields where it can be used as a gel, fields where ion exchange ability is lost, fields where hygroscopicity is required, and fields where body temperature is absorbed.

Patent applicant Asahi Kagyo Co., Ltd.

Claims (1)

[Claims] Carboxyl group, sulfonic acid group, tertiary amino group. Cellulose in the form of an aqueous gel in which the degree of substitution of hydrophobic groups that do not contain hydroxyl groups is 2.0 or more, and the degree of substitution of anionic groups that include carboxyl groups or oligosulfonic acid groups and their salts is 0.4 or more. derivative