JP2003335898A - Thermoplastic cellulose carbamate composition and fiber made from the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic cellulose carbamate composition comprising an environmentally friendly component which essentially comprises cellulose carbamate which is a biomass material, and a thermoplastic cellulose carbamate composition fiber made from this which shows an excellent melt spinnability, strength and elongation and a highly uniform fineness. <P>SOLUTION: The composition comprises at least cellulose carbamate and a plasticizer. The fiber is made from this composition. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplasticized cellulose carbamate composition containing cellulose carbamate as a main component and fibers obtained by melt spinning them.

[0002]

2. Description of the Related Art Cellulose has been receiving a great deal of attention recently as a biomass material produced in the largest amount on earth and as a material capable of biodegrading in the environment.

Regarding the utilization of cellulose as a fiber, it has long been practiced to spin short fibers such as cotton and hemp produced in nature and use them as they are. To obtain filament materials instead of short fibers, cellulose is dissolved in a special solvent system such as carbon disulfide such as rayon, lyocell, etc., or spun by wet spinning, or cellulose like cellulose acetate is used. The only method was to derivatize the compound and dissolve it in an organic solvent such as methylene chloride or acetone, and then perform spinning by a dry spinning method in which the solvent is evaporated while performing spinning.

However, the wet spinning method or the dry spinning method has a problem that productivity is low because of a slow spinning speed, and carbon disulfide, acetone, and
Since there is a strong concern that an organic solvent such as methylene chloride will have an adverse effect on the environment, it cannot be said to be a good yarn making method when considering harmony with the environment.

As a compound obtained by derivatizing cellulose, not only cellulose ester such as cellulose acetate but also cellulose carbamate is known. As a typical example of the cellulose carbamate currently commercially used, as shown in JP-A-60-108751, there is cellulose phenyl carbamate and the like, which is used in the field of column separating agents and the like. .

There is also a proposal to use cellulose carbamate as a fiber. For example, JP-A-60-12
No. 3502 can be mentioned. In this example, cellulose carbamate in which urea is allowed to act on cellulose is used to obtain cellulose soluble in an alkaline solution, and spinning is performed from the solution. Since the carbamate that reacts with cellulose is urea, cellulose alkyl carbamate and the like are not included in this method.

On the other hand, no report has been made on cellulose carbamate fibers using the melt spinning method.

[0008]

An object of the present invention is to overcome the above-mentioned problems and to provide a thermoplastic cellulose carbamate composition comprising a component having a low environmental load containing cellulose carbamate as a biomass-based material as a main component. Another object of the present invention is to provide a thermoplastic cellulose carbamate composition fiber which is excellent in melt spinnability and is excellent in not only strong elongation property but also uniformity of fineness.

[0009]

The above-mentioned object of the present invention can be solved by a thermoplasticized cellulose carbamate composition comprising at least 50 to 95% by weight of cellulose carbamate and 5 to 50% by weight of a plasticizer. it can.

Another object of the present invention is to use the above thermoplastic cellulose composition, which has a strength of 0.5 to 4 cN / d.
It can be solved by a fiber characterized by having a tex, an elongation of 2 to 50% and a U% of 0.1 to 5%.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Cellulose carbamate in the present invention means that the hydroxyl groups of cellulose are blocked by isocyanate which is a carbamate-forming agent. Specific types of cellulose carbamate include:
Examples thereof include cellulose phenyl carbamate and cellulose alkyl carbamate. The isocyanate used in the present invention is an aliphatic compound having a terminal isocyanate group or a phenyl compound. In the case of an aliphatic compound, it preferably has 1 to 20 carbon atoms and may be saturated or unsaturated. By selecting a carbon number of 20 or less, it is easily dissolved in the liquid phase and has high reactivity. More preferably, it has 1 to 15 carbon atoms.

The method for producing the cellulose carbamate used in the present invention may be any conventionally known method and is not particularly limited. For example, a method of using pyridine as a solvent has long been known as a method for synthesizing cellulose carbamate, and is disclosed in JP-A-60-1087.
In JP 51, a method of reacting cellulose with isocyanate in a pyridine solvent is used. Moreover, a method of carbamate-forming cellulose by using pyridine or dimethylformamide in supercritical carbon dioxide is reported in a collection of high molecular weight articles (Kakuno, 502 (58) 2001).

The degree of substitution of cellulose carbamate is preferably 0.5 to 2.9 per glucose unit. In order to obtain good biodegradability, the degree of substitution of cellulose carbamate is relatively low, for example, 0.
It is preferably 5 to 2.2, and in order to obtain good fluidity, it is preferably 2.2 to 2.9, for example, and can be appropriately determined depending on the purpose.

The content of cellulose carbamate in the thermoplastic plasticized carbamate composition is 50 to 95% by weight.
Is. When the content is 95% by weight or less, the thermoplasticizing effect of adding the plasticizer is increased, and the melt moldability is improved. When the content is 50% by weight or more, the strength which is a characteristic of cellulose carbamate is increased, and the spinning breakage rate is decreased.

As the plasticizer used in the present invention, compounds known as plasticizers can be adopted, but among them, compounds having an amide group in the molecular chain are preferable. This is because the interaction between the carbamate bond of the cellulose carbamate and the amide bond of the plasticizer is large, so that the compatibility is improved and the plasticizing effect is increased. Further, among the compounds having an amide group in the molecular chain, those having a long-chain alkyl group having a large interaction with the alkyl group or phenyl group introduced into the side chain of cellulose carbamate are preferable.
5-20 are preferable and, as for carbon number of an alkyl group, 8-15 are more preferable. Further, the boiling point is preferably 200 ° C. or higher because the plasticizer does not elute during melt spinning.
It is more preferably 250 ° C. or higher. Specifically, stearic acid amide and palmitic acid amide are preferable as the plasticizer, but not limited thereto.

The amount of the plasticizer compounded is 5 to 50% by weight based on the total weight of the obtained thermoplastic plasticized carbamate. By setting the blending amount to 50% by weight or less,
From the viewpoint of melt spinnability, the strength is increased and the spinning breakage rate is decreased, which is preferable. On the other hand, when the content is 5% by weight or more, from the viewpoint of heat fluidity, the spinning temperature can be lowered, and thermal decomposition of the composition is suppressed, which is preferable.

In the present invention, an epoxy compound, a weak organic acid, a phosphate, a thiophosphate, or the like is used as a stabilizer for preventing thermal deterioration and coloration, as long as it does not impair the required performance. You may add it individually or in mixture of 2 or more types. Further, other additives such as organic acid-based biodegradation accelerators, lubricants, antistatic agents, dyes, pigments, lubricants and matting agents may be blended.

The thermoplastic plasticized carbamate composition of the present invention preferably has a weight loss on heating at 180 ° C. of 5% by weight or less. Here, the heating weight loss rate means the weight loss rate at 180 ° C. when the sample is heated from room temperature to 400 ° C. at a heating rate of 10 ° C./min under nitrogen. If the heating loss is less than 5% by weight,
It is preferable because a large amount of the low molecular weight plasticizer is included, so that smoke is not generated during melt spinning and a fiber having good spinnability and good physical properties can be obtained. Most preferably, it is 3% by weight or less.

The thermoplastic cellulose carbamate composition in the present invention preferably has a melt viscosity at 180 ° C. and 1000 sec ⁻¹ of 50 to 300 Pa · sec. When the melt viscosity at 180 ° C. and 1000 sec ⁻¹ is 50 Pa · sec or more, the solidification after spinning is sufficiently advanced, and the fibers do not stick to each other even when converged, which is preferable. Further, in this case, since the back pressure of the die is sufficiently obtained, there is an advantage that the dispersibility becomes good and the uniformity of the fineness is secured. On the other hand, the melt viscosity is 30
When it is 0 Pa · sec or less, the spinnability of the spun yarn is good, sufficient orientation is obtained, and a fiber having excellent mechanical properties is obtained, which is preferable. Further, no trouble occurs due to an abnormal rise in pipe pressure.

From the viewpoint of good fluidity, 180 ° C., 10
Melt viscosity at 00 sec ^-1 is 70 to 250 Pa · s
ec is preferable, and 80 to 200 Pa · sec.
Is most preferable.

The strength of the thermoplastic plasticized carbamate composition fiber in the present invention is 0.5 to 4 cN / dtex.
Is preferred. When the strength is 0.5 cN / dtex or more, the passability in high-order processing steps such as weaving and knitting is good, and the strength of the final product is not insufficient, which is preferable. From the viewpoint of good strength characteristics, the strength is 0.
It is preferably 7 to 3.8 cN / dtex.
Most preferably, it is 0 to 3.5 cN / dtex.

The elongation of the fibers of the thermoplastic plasticized carbamate composition in the present invention is preferably 2 to 50%. When the elongation is 2% or more, yarn breakage does not occur frequently in higher-order processing steps such as weaving and knitting.
Further, fibers of 50% or less are not deformed if the stress is low, and dyeing defects of the final product do not occur due to weft shrinkage during weaving, which is preferable. The good elongation is more preferably from 5 to 45%, and from 10 to 40
% Is most preferred.

The U% of the fibers of the thermoplastic plasticized carbamate composition in the present invention is preferably 0.1 to 5%. When U% is 5% or less, fibers having excellent fineness uniformity can be obtained. A good U% is preferably 2% or less, and most preferably 1% or less.

When the cellulose carbamate used in the present invention and the plasticizer are mixed, a casting method using a known cosolvent may be used, or a commonly used known mixer such as a kneader, roll mill or Banbury mixer may be used. It may be used without particular limitation. In the case of mixing, in order to facilitate the mixing, the particles of cellulose carbamate may be previously finely crushed into 50 mesh or more by a crusher. Further, a plasticizer may be added during the synthesis of cellulose carbamate to obtain the cellulose carbamate containing the plasticizer simultaneously with the production of the cellulose carbamate. Further, in order to reduce inclusion of air bubbles as much as possible, it is desirable that the mixture is pelletized by using an extruder before being supplied to the melt spinning machine, or the extruder is preferably connected to the melt spinning machine by piping. In addition, the pelletized thermoplastic cellulose carmate composition is preferably dried to a water content of 0.1% by weight or less prior to melt spinning in order to prevent hydrolysis during melting and generation of bubbles.

In the melt-spinning method used in the present invention, the above-described composition can be melted by heating in a known melt-spinning machine, then extruded from a spinneret, spun, and optionally stretched and wound. At this time, the spinning temperature is preferably 160 ° C to 210 ° C, more preferably 170 ° C to 190 ° C. When the spinning temperature is 160 ° C. or higher, the melt viscosity is lowered and the melt spinnability is improved, which is preferable. Also 190 ℃
The following is preferable because thermal decomposition of the composition is suppressed.

According to the present invention, the fiber obtained from the obtained cellulose carbamate composition has excellent mechanical properties and uniformity of fineness, and is excellent in biodegradability. Due to its excellent heat fluidity, the yarn breakage rate during spinning is extremely low, resulting in excellent productivity. Further, the obtained long fibers may be used as a fiber structure such as a woven fabric or a knitted fabric, or as a non-woven fabric by a melt blow method or a spun bond method.

[0027]

The present invention will be described in more detail with reference to the following examples, but of course the present invention is not limited thereto.

Elemental analysis, melt viscosity, heating loss rate,
The strength and elongation, U%, and texture were evaluated by the following methods.

(1) Elemental analysis Carbon, hydrogen, oxygen of the obtained cellulose carbamate,
It was calculated from the elemental analysis value of nitrogen. In addition, C, H, and N were performed using a fully automatic elemental analyzer varioEL (Elementar).
In addition, O is a CHN-O RAPID fully automatic elemental analyzer (Elementar
Company) was used.

(2) Melt viscosity Using a capillary rheometer manufactured by Toyo Seiki Co., Ltd. (trademark: Capirograph 1B, L = 10 mm, D = 1.0 mm die used), measurement temperature 180 ° C., shear rate 10
The viscosity was measured at 00 sec ^-1 , and the melt viscosity was obtained.

(3) Heat loss rate TG-DTA2000S manufactured by Mac Science Co., Ltd.
At room temperature to 400 ° C under nitrogen at 10 ° C /
When the sample was heated at the temperature rising rate of min, the weight change of 10 mg of the sample at 180 ° C. was defined as the heating weight loss rate.

(4) Strength and Elongation Tensileon UCT-100 type manufactured by Orientec Co., Ltd. was used to perform a tensile test under the conditions of a sample length of 20 cm and a pulling speed of 20 mm / min. The strength (cN / dtex) was used. The elongation at break was taken as the elongation (%) of the fiber.

(5) U% Worcester Tester 4-C manufactured by Zellbeger Worcester
At X, measure for 1 minute at a yarn feeding speed of 25 m / min
The obtained value was defined as U%.

(6) Texture A 27-gauge circular knitting was prepared using the obtained fiber, and the texture was evaluated by a sensory test. Those having a sufficient dry feeling were marked with O, those having no dry feeling were marked with Δ, and those having a noticeable slimy feeling were marked with X.

Synthesis Example 1 1 g of cellulose (dissolving pulp manufactured by Nippon Paper Industries Co., Ltd.) was dispersed in 50 ml of dry pyridine, 8 ml of phenyl isocyanate was added thereto, and the mixture was kept at 110 ° C. with stirring. After 16 hours, the reaction product was poured into 1 L of methanol, a white solid formed was filtered off, and dried under reduced pressure at room temperature for 2 hours and at 60 ° C. for 3 hours. The yield was 1.45g. Elemental analysis showed C60.30%, H5.01%, N7.13%, O2
It was 7.55% and the degree of substitution was 2.1.

Cellulose phenyl carbamate was obtained by the above method.

Example 1 Cellulose Phenyl Carbamate (Substitution Degree 2.1) 70
% By weight and 30% by weight of stearamide as a plasticizer
Were mixed in a kneader at 180 ° C. to obtain a mixed polymer.
This was cut into about 5 mm square to obtain pellets of the thermoplastic cellulose carbamate composition. The pellets were dried in a hot air dryer heated to 80 ° C. for 10 hours, and then the melt viscosity at 180 ° C. and 1000 sec ⁻¹ was measured. The melt viscosity was 142.2 Pa · sec. The heating weight loss rate was 2.2%.

The pellets thus obtained were melted at a melting temperature of 180 ° C. and a pack temperature of 180 ° C. using a single-screw extruder type melt spinning machine, and 0.20 mmφ-0.30 mm
It was spun from a die having 36 L hole holes. No smoke was observed from the spun yarn. The spun yarn was cooled by a chimney wind at 25 ° C., then taken up by a godet roller at a speed of 500 m / min and wound by a winder. The spinnability was good, and spun yarn breakage was not observed.

The obtained fiber has a strength of 1.1 cN / dt.
The ex and elongation were 18%, and the mechanical properties were excellent.
Further, U% was 0.9%, and the uniformity of the fineness in the fiber longitudinal direction was excellent.

A knitted fabric was prepared using the obtained fiber and the texture was evaluated. As a result, no slimy feeling was observed at all, and the desired texture was soft and dry.

Synthesis Example 2 Cellulose butyl isocyanate was obtained in the same manner as in Synthesis Example 1 except that 4 ml of butyl isocyanate was used instead of phenyl isocyanate. Elemental analysis showed that C39.33%, H5.75%, N5.10%, O
It was 25.22% and the degree of substitution was 1.5.

Cellulose butyl carbamate was obtained by the above method.

Example 2 Pellets were prepared in the same manner as in Example 1 except that 90% by weight of cellulose butyl carbamate (degree of substitution: 1.5) and 10% by weight of stearic acid amide were used as a plasticizer.
The melt viscosity and the weight loss on heating were measured. Melt viscosity is 21
It was 3.2 Pa · sec and the heating weight loss rate was 1.8%.

When the obtained pellets were spun in the same manner as in Example 1, no smoke was recognized from the spun yarn. The spinnability was good and no yarn breakage was observed.

The obtained fiber has a strength of 1.0 cN / dt.
The ex and elongation were 25% and the mechanical properties were excellent.
Moreover, U% was 1.2%, and the uniformity of fineness was excellent.

When a knitted fabric was prepared using the obtained fibers and the texture was evaluated, a slimy feeling was not recognized at all, and a soft and dry desirable texture was obtained.

Synthesis Example 3 Cellulose phenyl isocyanate was obtained in the same manner as in Synthesis Example 1 except that the reaction time was 22 hours. Elemental analysis showed that C60.86%, H4.97%, N
7.39% and O26.78%, and the degree of substitution was 2.3.

Cellulose phenyl carbamate was obtained by the above method.

Example 3 Cellulose Phenyl Carbamate (Substitution Degree 2.3) 60
Pellets were prepared in the same manner as in Example 1 except that 40% by weight of palmitic acid amide was used as the plasticizer, and the melt viscosity and the weight loss on heating were measured. The melt viscosity was 140.1 Pa · sec, and the heating weight loss rate was 4.2%.

When the obtained pellets were spun in the same manner as in Example 1, no smoke was recognized from the spun yarn. The spinnability was good and no yarn breakage was observed.

The obtained fiber has a strength of 0.6 cN / dt.
The ex and elongation were 33% and the mechanical properties were excellent.
Moreover, U% was 1.1%, and the uniformity of fineness was excellent.

When a knitted fabric was prepared using the obtained fibers and the texture was evaluated, a slight slimy feel was felt, but it was within an acceptable range.

Comparative Example 1 Pellets were prepared in the same manner as in Example 1 except that 100% by weight of cellulose phenylcarbamate (substitution degree 2.1) synthesized in Synthesis Example 1 was used, and the melt viscosity and the weight loss on heating were measured. . The melt viscosity was 627.5 Pa · sec, which was a remarkably high value. The heating weight loss rate was 1.5%.

Using the obtained pellets, an attempt was made to spin in the same manner as in Example 1, but the melt viscosity was too high and the spun yarn was not thinned and could not be taken up.

Comparative Example 2 Pellets were prepared in the same manner as in Example 1 except that 40% by weight of cellulose phenyl carbamate (substitution degree 2.1) synthesized in Synthesis Example 1 and 60% by weight of stearic acid amide were used as a plasticizer. It was prepared, and the melt viscosity and the weight loss on heating were measured. The melt viscosity was 20.2 Pa · sec. The heating weight loss rate was 28.2%, which was a remarkably high value.

Using the pellets thus obtained, spinning was attempted in the same manner as in Example 1. However, at a spinning speed of 500 m / min, yarn breakage occurred frequently and the yarn could not be taken off. Therefore, the spinning speed was reduced to 200 m / min. Spinning was performed. Heavy smoke was observed from the spun yarn, and the running yarn was not stable.

The obtained fiber has a strength of 0.2 cN / dte.
x was low and the elongation was 32%. Also, U% is 6.6.
% And the uniformity of fineness was inferior.

When a knitted fabric was prepared using the obtained fiber and the texture was evaluated, it was found to have a very slimy feel and could not be used as a cloth.

[0059]

[Table 1]

[0060]

Industrial Applicability According to the present invention, a thermoplastic cellulose carbamate composition derived from cellulose, which is a biomass-based material, can be obtained. From this composition, it is possible to provide a fiber having excellent properties by melt spinning, which is a spinning method with a small environmental load. The composition and fiber obtained are suitable for fields utilizing biodegradability, that is, agricultural materials, forestry materials, marine products materials, civil engineering materials, sanitary materials, daily necessities, clothing fibers, industrial fibers, non-woven fabrics, etc. Can be used.

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Claims (5)

[Claims] 1. Cellulose carbamate 50 to 95% by weight
And a thermoplasticized cellulose carbamate composition comprising at least 5 to 50% by weight of a plasticizer. 2. Thermoplasticized cellulose according to claim 1, wherein the weight loss on heating at 180 ° C. is 5% by weight or less and the melt viscosity at 180 ° C. and 1000 sec ⁻¹ is 50 to 300 Pa · sec. Carbamate composition. 3. The thermoplastic plasticized carbamate composition according to claim 1 or 2, wherein the cellulose carbamate is at least one cellulose carbamate selected from the group consisting of cellulose phenyl carbamate and cellulose alkyl carbamate. 4. The plasticizer is a compound having an amide group in the molecular chain, and the plasticizer is any one of claims 1 to 3.
The thermoplastic plasticized carbamate composition according to the item. 5. The thermoplastic carbamate composition according to claim 1, which has a strength of 0.5 to 4 cN /.
A fiber having a dtex, an elongation of 2 to 50% and a U% of 0.1 to 5%.