JPS6044501A - Cellulose ether - Google Patents

Abstract

PURPOSE:To provide a cellulose ether of good mechanical properties, alkali- soluble at low temperatures, with low substitution degree and specific value of parameter representing intramolecular hydrogen bond-forming capability determined by infrared absorption spectroscopy following deuteration, capable of production at low cost through pollution-free process. CONSTITUTION:The objective cellulose ether alkali-soluble at low temperatures with a substitution degree <=0.10 and a parameter (Hb) representing intramolecular hydrogen bond-forming capability determined by infrared absorption spectroscopy following deuteration satisfying the condition expressed by equation (OD3430 and OD3360 are optical densities after heavy water substitution at wave numbers corresponding to each suffix indicated) can be obtained by immersing cellulose in an aqueous solution of sodium hydroxide, carrying out a squeezing, charging, e.g., a kneader, with the resultant material, followed by adding, while agitating, acrylonitrile in a gaseous form to the system to perform reaction.

Description

[Detailed description of the invention]

(a) Technical field The present invention is a low cost and non-polluting process.
The present invention relates to a cellulose ether with excellent solubility and a low degree of substitution, which is useful as a raw material for producing Ti fibers and films having good mechanical properties. (b) Prior Art Conventionally, there are two methods for producing fibers and films using cellulose as a raw material. The first method, as typified by the viscose method, cuprammonium method, and condensation method, involves dissolving cellulose directly in a solvent to create a concentrated solution, and extruding this through a nozzle or die.
This method involves coagulation and regeneration to obtain fibers and films. The second method is an acetyl group, an ethyl group, a methyl group,
Chemical reaction C: Substituents such as carboxyl groups, cyanoethyl groups, nitro groups, etc. are introduced into cellulose in advance to produce cellulose derivatives that exhibit good solubility in various solvents C2, thereby obtaining fibers and films. . Viscose method, copper ammonia method, organic solvent method 62°C
The disadvantages of the first method are the inferiority and explosiveness of the solvent used, the high cost of recovery, and the discharge of 1M metal! : It is a pollution problem. On the other hand, the disadvantage of the second method, in which a cellulose derivative is prepared and used as a raw material to form a film or film, is that in order to obtain appropriate solubility, it is necessary to increase the rate of introduction of two substituents. As a result, cellulose C is expensive, and the types of substituents introduced are: In order to compensate for these drawbacks, we lowered the ratio of C2 and substituent introduction to produce an excellent cellulose derivative with mff1 in a state close to cellulose C2. Te-pea and film (;
One possible method is to mold it. Conventionally, when the ratio of introduction of substituents (degree of substitution) is lowered, regardless of the type of substituent, water-soluble, 0.
．． It is known that an alkali-soluble cellulose derivative can be obtained in the range of 15 to 0.5. However, it is important to note that if the degree of substitution is less than 0.15, the solubility of cellulose derivatives will be significantly worse. Since it is a homogeneous reaction, the lower the degree of substitution, the more difficult it is to obtain a homogeneous cellulose dicore, and therefore it has not been put to practical use industrially at all. (c) Purpose of the Invention In view of the current situation as described above, the present inventors have made extensive studies and have found that, in stark contrast to the above-mentioned prior art C, hydrogen bonding within one molecule, etc. The inventors have discovered that by controlling the structure of 2 cellulose ethers having excellent solubility even with a low degree of substitution can be produced, making it possible to realize the present invention. An object of the present invention is to provide a cellulose ether that exhibits excellent solubility and can be made into fibers or films having good mechanical properties.
Preferred are carboxymethyl group, carboxyethyl group, carbamoylethyl group, and methyl group. A cellulose ether containing at least one selected from ethyl group, propyl group, cyanethyl group, hydroxyethyl group, and doroquine glovir group, and has intramolecular hydrogen calculated by the single-layer infrared method. It is a cellulose ether whose parameter (Hb) indicating binding property satisfies the conditions of formula 11 as shown below and shows alkali solubility at low temperature even though it is a derivative with an extremely low degree of substitution of 0.10 or less.Special C, this low substitution Cellulose ether is 6-18% by weight
Shows excellent solubility in moderately alkaline solutions. In the present invention, t: 3430 cm = and 3360 c as a measure representing the intramolecular hydrogen bonding property of the inaccessible hydroxyl group region that is not replaced by 1 deuterated water when deuterated for 2 hours under the conditions described below.
The infrared intensity ratio (I(1)) of m-' is used. In equation (1), ℃-0D3430 and 0n336G are the subscripts (: are the optical densities at the corresponding wave numbers, and 34
30cm-' is O)I stretching vibration derived from intramolecular hydrogen bonding. 33C5Oc++- is an OH stretching vibration that is not affected by either parallel or perpendicular polarization 1:. Here, the parameter (Hb) given by the formula (1) is defined as the "degree of intramolecular hydrogen bonding", and is hereinafter abbreviated as the degree of intramolecular hydrogen bonding (0Ib). 0→ Embodiment Generally, it is known that due to the presence of strong hydrogen bonds due to its molecular structure, it has high resistance to solvents and exhibits excellent mechanical properties. Therefore, it is expected that the presence or absence of hydrogen bond formation is related to the solubility of cellulose.In this sense, the degree of intramolecular hydrogen bonding represents the relationship between the a-structure and solubility of the resulting cellulose ether. It is an extremely powerful indicator. The degree of substitution of the cellulose ether of the present invention is basically 0.
10 or less, preferably from 0.10 to 1,03, preferably from 0.10 to 0.05 (- is in the range of 0.10 to 05). As the cost increases, when fibers, films, etc. Although it varies depending on the type, if the degree of substitution is less than C20.03, the solubility may decrease. Not preferred.Category 1 of the present invention: It is difficult to uniformly define the minimum degree of substitution of the cellulose ether to be added. After dissolution for 2 months, it was stored for 48 hours or longer as a solution and the criterion was whether C2 existed or not.For example, using a caustic soda aqueous solution of 1 ON, polymer When dissolved at The minimum degree of substitution cannot be unambiguously determined from this solubility because it varies depending on It is a basic constituent requirement of the present invention that the degree of substitution is 0.10 or less, even if the degree of substitution is 0.10 or less.
Cellulose ethers with a value exceeding 1.2 are outside the scope of the present invention. Of course, the degree of substitution and (I(b)) have an inverse relationship, and the same can be said for °C [) The degree of intramolecular hydrogen bonding of the cellulose ether of the present invention is 1.
2 or less, and

[: Considering solubility, (I(b
) is 1.0 or less, and IA, :+@conversion degree is 0.
Higher than 1 (both are common (Nawate 1 (Hb) is also 1)
．． 2 or less C changes, improving solubility, but when molded into fibers or films, it is difficult to form good hydrogen bonds and the chemical resistance and mechanical properties are significantly inferior. ) is extremely difficult to dissolve uniformly due to strong hydrogen bonds, and it is impossible to obtain a practical dope.Furthermore, the cellulose ether of the present invention has the following characteristics: This can be revealed by the fact that the spectrum obtained by the hydrogenated infrared method shows a peculiar absorption. This is an absorption spectrum. Figure 1 (OQ) is an infrared absorption spectrum of the cellulose film of the present invention after deuteration. Figure 1 (a) C is 3
There are absorption peaks based on OH stretching vibrations (two-based absorption peaks) that form intramolecular hydrogen bonds at 48 cm, ' and 3430 cm, but they do not exist in the cellulose ether of the present invention shown in Figure 1 fbl. This intramolecular hydrogen bond 1 : The presence of a peak based on solubility C
Two are extremely important, and equation (1) is a quantitative generalization of these. Those with these peaks exhibit chemical resistance similar to that of cellulose and are difficult to dissolve in solvents (Y), while those without them exhibit excellent solubility; The solubility of the cellulose ether of the present invention can be determined simply by looking at the absorption spectrum. : is 3480 in the infrared absorption spectrum
Although there are no absorption peaks at Nishiki-1 and 3430 cm-', water, acids, and inorganic salts are used as coagulants.
When fibers and films are molded, an absorption peak of 3480c+A-'b-3430cm appears as shown in Figure 1 (C), resulting in fibers and films with excellent chemical resistance and physical properties. The cellulose ethers of the present invention (substituents included are preferably -carboxymethyl, carboxyether, carbamoylethyl, methyl, ethyl, the group consisting of propyl, cyanoethyl, hydroxyethyl, hydroxypropyl) One or more selected from (J or more). Particularly (2) When used as an acrylonitrile or acrylamiton ether agent, derived cyanethylcellulose, cyanethylcarbamoylethylcellulose, cyanoethylcarboxyethylcellulose-cyanoethylcarbamoylethylcarboxyethylcellulose,
Carbamoylethylcarboxyethylcellulose, carbamoylethylcellulose, and carboxyethylcellulose are preferably used. This is due to the fact that these substituents are relatively large and have excellent solubility;7 production costs are low; uniform reactions can be carried out; the obtained fibers and films can be easily recycled; This is due to reason C2, such as the ability to obtain mechanical properties and the ability to obtain a dope suitable for molding. usually. The type of substitution contained in cellulose ether is mild, but cellulose ether (C
: may introduce two or more types of substituents. In one typical manufacturing method for obtaining the cellulose derivative of the present invention, first, 5 to 35% Na
OH aqueous solution I: Add the reactant for introducing the substituent and thoroughly disperse the reactant. Next, while maintaining this temperature, raw cellulose (
Number average degree of polymerization 200 to 2,000) Add Y. Leave it for several minutes to several hours. Next, the temperature is raised to a temperature at which one reaction starts, and the reaction is carried out to introduce a substituent. After the reaction was completed, one reactant was washed with alcohol. Collect and dry. There is no particular problem even if the solution is washed once with water, but the solubility may be slightly reduced. The degree of intramolecular hydrogen bonding (Hb) can be evaluated by the following method. Basically, the infrared absorption spectrum can be recorded after deuterating the sample. A schematic diagram of the apparatus is shown in Figure 2. ℃(
Two-chilled 10% Na0Hi two-chilled melt. Next (:, cool the dissolved solution on a slide glass, l:C;
Coat, dip in methanol for $2, and coagulate. After thoroughly washing with methanol, it is dried to obtain a film with a thickness of 10 to 30 μm. This film is set with two deuterium cells (Glc). Cells (61 are set with C2Zoo"Ct to remove moisture and prevent the absorption of heavy water. After leaving it for 10 minutes and removing excess moisture. Blank. Next, measure the infrared absorption spectrum of C2. Send dry N2 gas at 25°C obtained from the cylinder (1) through the drying silica gel (2) at a flow rate of 1000 m//min ((31 is a flow meter). ), heavy water (20C1-) set at 25°C was placed in a D20 bubbling container (4
), and then the sample on the sample stage (5) is deuterated in the deuteration cell (6) ζ:. After deuteration was carried out under these conditions for 120 minutes, measurement was performed using an infrared absorption spectrometer (7) ζ:. First, draw a baseline that is tangent to the spectrum C of +3600cm-'' and 3000trrL-', and
-' and 3360cIn"", the j1 pass rate of the intersection of the perpendicular line and the baseline corresponds to the intensity Il of the incident light of each wave number.
It was adopted as l. Also, '3430cm-1 and 33
8! The ratio was used. obtained l
. If the optical density of Tanigumi number is calculated from and X and the ratio is taken, the above-mentioned (Hb) is obtained. In the above method, the film method is used for evaluation on the premise that cellulose ether, which is alkali-soluble, retains its original structural history even if it dissolves once. It can be evaluated. Of course, whether the same sample is evaluated by the KBr method described later or by the film method, there is almost no difference in (Hb)2. A sample powdered with less than 200 meshes in a sealed container from which 200 meshes or less of After drying for 811i5 and measuring the IR as a KBr tablet in the sealed container described above, a spectrum can be obtained and the (Hb) value? can be determined. Of course. A moisture control unit with phosphorus pentoxide is used during IR measurements as well. The cellulose ether of the present invention has a
An aqueous alkaline solution (usually caustic sonic) of 18 weight ts (=concentration of at least 3 weight ts) is dissolved.The resulting solution has excellent spinnability C: and can be used for forming fibers and films. Of course, an alkali other than caustic soda may be used to dissolve the cellulose.Example 1The present invention will be illustrated in Examples below, but is not limited to this.Example 1 This example shows two cellulose ethers obtained when using °C acrylonitrile as an etherification agent.
OH aqueous solution 150 Q gC After soaking for 30 minutes at room temperature (25°C), squeezed approximately 400 gN with a compressor.
The pressed product was put into a jacket kneader heated to 40°C, and 13.5 g of acrylonitrile was added while stirring.
was added in gaseous form and reacted for 40 minutes. In the dark, water 12
00g was added and aged for 3 hours. The aged product was poured into methanol with stirring for 10 minutes, and washed. After washing. It was dried with hot air at 60°C. The degree of substitution of the obtained product is
Chemical analysis (titration method) and cumulative analysis (C, ILN analysis) revealed that the carboxyethyl group was 0. (+68- It was found that there was a carbamoylethyl group of 0.027S. This cellulose ether was ground in a coffee mill, sieved through a 200-mesh sieve, and the resulting powder was measured for infrared absorption spectrum using the KBr method C2.) ), the result is
(Hb) was 0.93. 80 g of the product was dissolved in 920 g of 12 wt. %H2SO4 aqueous solution was obtained.The (Hb) of this film after deuteration was 1.27, indicating that the degree of intramolecular hydrogen bonding was high. The hydrogen bonding property of the molded product obtained from the invention dope is higher than that of the original cellulose ether, and improved mechanical properties are expected.

[Brief explanation of the drawing]

FIG. 1 shows the infrared absorption spectrum of cellulose or cellulose derivatives when deuterated using the apparatus shown in FIG. 2. (a) I (b) I (C) are cellulose regenerated from the copper ammonia method in a conventional manner, respectively;
Cellulose ether of the present invention (carboxyethylcellulose with a degree of substitution of 0.08)
This is a sample obtained by dissolving the aOH aqueous solution C and then solidifying the 65% by weight sulfurized aqueous solution C.9 Figure 2 shows a schematic diagram of the deuterated infrared apparatus. 2)
T;! Silica gel for drying, (31 flow Hi meter, (41
HA020 HUFF IJ 7f container, (51+1 test n units, (6) is the deuteration cell, (7) is the infrared absorption spectrum measurement device itself. Watch applicant: Asahi Kasei Industries Co., Ltd. Patent application agent, patent attorney) Patent Attorney Akira Aoki Kazuyuki Nishidate Patent Attorney 1) Yukio Patent Attorney Akira Yamaguchi Patent Attorney Masaya Nishiyama S- Figure 1 (a) (b) Figure 1 (C) Figure 2

Claims (1)

[Scope of Claims] 1. Cellulose ether with a degree of substitution of 0.10 or less. It is characterized by satisfying the conditions. A cellulose ether that is alkali-soluble at low temperatures. In formula (1), oD3, 3o and 0D336o are the wavenumbers corresponding to the subscripts (2, respectively, and are the chemical densities after heavy water exchange. 2. The substituent is carboxymethyl 1. Carboxyethyl, carbamoylethyl, methyl, Special fFF which is at least one selected from the group consisting of ethyl-propyl, cyanethyl-hydroxyethyl and hydroxypropyl
Cellulose ether according to claim 1. 3. The cellulose ether according to claim 2, wherein the substituent is a substituent derived when acrylonitrile or acrylamide is used as an etherification agent.