JP3159797B2 - Halogen-based solvent and method for producing solution and three-dimensional fiber using the solvent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides an improved solvent having low toxicity, low flammability and low ability to destroy the ozone layer, and a polyolefin solution using the solvent. Further, the present invention provides an improved production method for obtaining a three-dimensional polyolefin fiber having excellent strength and openability used for a nonwoven fabric sheet using the solvent and the solution.

In other words, it relates to an improved solvent which is non-toxic, non-flammable and extremely safe to use, a polyolefin solution using this solvent and an improved flash spinning method. Furthermore, the solvent according to the present invention is a solvent that can be applied not only to a polyolefin solution for flash spinning, but also to a detergent, a foam, a gas for producing a hollow fiber, a reaction solvent, and the like.

[0003]

BACKGROUND OF THE INVENTION A process for producing polyolefin network fibers is known as flash spinning. In this flash spinning method, a polyolefin is added to an organic solvent which can be called a liquefied gas, and the polyolefin solution is adjusted under high temperature and high pressure. This is a method in which the solution is further jetted through a spinneret into an atmosphere under normal temperature and normal pressure to produce three-dimensional fibers, which is a well-known spinning method.

For example, this spinning method is disclosed in US Pat.
No. 519, USP3227794, USP3
227784, US Pat. No. 3,467,744, U.S. Pat.
No. SP3564088, US Pat. No. 3,756,411, EP285670A1, EP321567A
No. 1, EP357364A2, Japanese Patent Publication No. 40-
No. 28125, JP-B-42-19520, JP-A-62-33816, JP-A-63-50512
No., etc.

[0005] The fibers obtained by the flash spinning include short fibrous materials and continuous three-dimensional fibrous materials.
The former is used as a synthetic pulp, and the latter is used as a nonwoven sheet. This nonwoven sheet is generally referred to as synthetic paper, and the most significant features of this product are that it is water-resistant, strong, light, and lint-free. This is highly valued in the world, and this non-woven fabric sheet is used for airmail envelopes, floppy disk sleeves, oxygen absorber bags, desiccant bags, medical sterilization bags, building insulation dew condensation prevention cloth, reactor power generation work clothes and asbestos work. clothes,
It is applied to safety protection work clothes. In order to manufacture a product having these characteristics, a three-dimensional fiber having high strength and well opened is essential. This is because a dense and air-permeable uniform sheet cannot be obtained without such fibers.

[0006] As a product of such a nonwoven fabric sheet,
Tyvek (Tyvek registered trademark) manufactured by DuPont, USA
And Luxer® manufactured by the applicant are already commercially available. By the way, the polymer solvent used in the flash spinning method needs to have the following properties, and this is already known in US Pat. No. 3,081,519 or the like. That is, the boiling point of the solvent is at least 25 ° C. lower than the melting point of the polymer used,
A solvent that is inert to the polymer under spinning conditions, a good solvent for the polymer at a temperature and pressure suitable for adjusting the polymer solution, and a 1% polymer below the boiling point of the solvent A solvent that dissolves only the following, a solvent that can be immediately phase-separated during spinning to form a phase substantially composed of a polymer, and that is a solvent that hardly remains in the separated polymer phase;
It is.

Specific examples of the solvent include aromatic hydrocarbons such as benzene and toluene, aliphatic hydrocarbons such as butane, pentane, hexane, heptane and octane, and isomers and homologs thereof, and oils such as cyclohexane. Acyclic hydrocarbons, or unsaturated hydrocarbons, methylene chloride, carbon tetrachloride, chloroform, ethyl chloride, halogenated hydrocarbons such as methyl chloride, ethanol, methanol, alcohols such as methanol, hexafluoroisopropanol, esters, ethers, ketones, Chlorinated aliphatic hydrocarbons such as nitrile, amide, trichlorofluoromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, sulfur dioxide,
Carbon disulfide, nitromethane, water and various liquid mixtures described above are known.

[0008] Among these solvents, the optimum one is appropriately selected in consideration of various conditions of the spinning method used and the type of polymer used. However, as a solvent for the flash spinning method of polyolefin, it is excellent in polymer solubility and spinnability, and furthermore, nonflammable, non-toxic trichlorofluoromethane, 1,1,2-trichloro-1,
2,2-Trifluoroethane is preferred. In particular, trichlorofluoromethane is the best solvent.

In flash spinning, since a polymer solution under high temperature and high pressure is jetted into the atmosphere to gasify, the solvent has a low boiling point, does not thermally decompose even at high temperatures, and has sufficient lipophilicity to dissolve the polyolefin. It is required to be a solvent and at least low toxic and flame retardant. That is, in the flash spinning, the solvent is gasified to be surely separated from the polymer, and the gasified solvent is collected and made into a liquid by an operation such as cooling and compression. Therefore, flash spinning is performed in a large enclosed space. Otherwise, the gasified solvent cannot be recovered. The size of the closed space is, for example, 2000 m ³ .
Filling such a huge space with flammable gas significantly increases the possibility of fire, explosion, etc.,
It is extremely dangerous and virtually no flammable gas can be used as a solvent.

Normally, a corona discharge device or a high-voltage static elimination device is built in this sealed space, and can serve as a source of ignition of combustible gas. For this reason, more flammable gas cannot be used. Furthermore, in the closed space,
There are various types of equipment such as metal conveyors, corona charging devices, and spinning heads for making nonwoven fabrics, and there is a case where workers are forced to come in and out of a closed space for their repair and maintenance. Further, the outlet of the formed nonwoven fabric sheet is a non-contact seal, and the gas in the sealed space constantly leaks to the work place. Therefore, if it is toxic,
It cannot be used as a solvent for flash spinning. For these reasons, the only solvent that can be used for flash spinning is trichlorofluoromethane, which is a non-flammable and non-toxic solvent.

However, in recent years, it has been discovered that all halogenated hydrocarbons in which all hydrogen has been replaced by chlorine and fluorine have a very high ozone destruction ability as specific freon (also referred to as chlorofluorocarbon or CFC).
Production was banned by the year 2000 in order to protect the earth. Naturally, the specific fluorocarbon, trichlorofluoromethane, 1,1,2-trichloro-1,2,2-
Trifluoroethane is also banned from production and cannot be obtained. Therefore, trichlorofluoromethane cannot be used as a solvent for the flash spinning method of polyolefin.

From such a background, a flash spinning method using a new solvent without using trichlorofluoromethane which is a specific freon has already been proposed. That is, US Pat. No. 5,032,326, EP 0357381
A2 and JP-A-2-139408 disclose methylene chloride and an alternative fluorocarbon such as chlorofluoromethane,
Flash spinning using a mixed solvent with 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, 1,1,1,2-tetrafluoro-2-chloroethane, 1-chloro-1,1-difluoroethane, etc. A method is disclosed.
Also, US Pat. No. 5,081,177, US Pat.
No. 25, EP 0 361 684 A1, JP
JP-160909 discloses 1,1-dichloro-2,
2,2-Trifluoroethane, 1,2-dichloro-1,
2,2-Trifluoroethane, 1,1-dichloro-2,2
A spinning method using difluoroethane, 1,2-dichloro-1,1-difluoroethane, 1,1-dichloro-1-fluoroethane and the like is further described in EP 0407953 A2, in which polypropylene is used with 1,1-dichloro-
2,2,2-trifluoroethane, 1,2-dichloro-
A method of spinning using 1,2,2-trifluoroethane or the like, and furthermore, EP 357364A4 and
No. 76809 proposes a method of spinning using methylene chloride and carbon dioxide. Also, EP04
Japanese Patent Application Laid-Open No. 14498A2 and Japanese Patent Application Laid-Open No. 3-152209 propose a method using a mixed solvent system of water-containing organic solvents. EP 431 801 proposes a method of spinning using carbon dioxide and water.

Further, 1,1-dichloro-2,2,3,
3,3-pentafluoropropane and / or 1,3
A method of spinning using a mixture of -dichloro-1,2,2,3,3-pentafluoropropane and a hydrocarbon is disclosed in JP-A-4-185708. However,
All of these already proposed flash spinning methods have drawbacks when spinning with polyolefins.

For example, a mixed solvent of methylene chloride and an alternative fluorocarbon proposed in US Pat. No. 5,032,326 is
It may be used temporarily as a laboratory solvent, but not as an industrial solvent. This is because methylene chloride is highly toxic and may be carcinogenic. As an index indicating the degree of toxicity, ACGIH (American Conference of Govermental
TLV of Industrial Hygienists) (T hreshold L im
its V alues of Airbone Contaminants) is known. The TLV of trichlorofluoromethane is 1000 ppm
Whereas that of methylene chloride is only 50 ppm, which is clearly more toxic than trichlorofluoromethane. Moreover, methylene chloride is also registered as a carcinogen. Therefore, it is apparent that methylene chloride and a mixed solvent thereof cannot be used industrially as a solvent for flash spinning. Furthermore, there is a problem in using methylene chloride in view of the properties required for the solvent during spinning. The reason is that the heat of evaporation of methylene chloride is
78.7 cal / g, trichlorofluoromethane 4
This is much larger than 3.5 cal / g. This means that when methylene chloride is used as the solvent, the spun yarn spun by flash is easily wetted by the remaining solvent. As pointed out in Japanese Patent Application Laid-Open No. 3-76809, the wet yarn has a commercial value because it has a tendency to adhere and wind around a roller used to solidify the yarn into a sheet structure. It cannot be made into a non-woven fabric sheet and cannot be produced commercially. Therefore, when using methylene chloride as a solvent, a low-boiling gas is allowed to coexist to promote the evaporation of methylene chloride remaining in the fiber after spinning, and at the same time, increase the polymer concentration of the spinning solution in advance. It is necessary. Increasing the polymer concentration has the effect of increasing the amount of coagulation heat generated in the polymer solution when flashing the polymer solution and utilizing the heat to promote drying of the spun yarn. In this case, if either one of the use of a low-boiling gas and the increase of the polymer concentration is lacking, a wet yarn will result. However, when the polymer concentration of the spinning solution is increased, the spread state of the obtained spun yarn is deteriorated, and the quality of the sheet-like product tends to decrease. Therefore, it is understood that methylene chloride cannot be used from the viewpoint of such spinnability.

There is also a problem with the proposal of using an alternative chlorofluorocarbon as disclosed in US Pat. No. 5,081,177. 1,1-
Dichloro-2,2,2-trifluoroethane and its isomers have been shown in recent studies to produce tumors, albeit benign, in rats. Furthermore, these alternative Freon are
Since it is a poor solvent for high-density polyethylene, which is a typical example of polyolefin, there is another problem that high-density polyethylene cannot be dissolved when used alone. Therefore,
In order to improve the solubility, a technique using a hydrocarbon, methylene chloride, or the like as a co-solvent has been disclosed at the same time. However, even if the alternative chlorofluorocarbon coexists with a hydrocarbon or methylene chloride, the ratio of the chlorofluorocarbon alternative to the solvent is still as high as 50% or more. The property remains strong, and it is still difficult to dissolve in high-density polyethylene, and the problem that the dissolution rate is slow still remains. Thus, 1,1-dichloro-2,2,2-trifluoroethane and its isomers have problems in toxicity and solubility of high-density polyethylene. Similarly, 1,1-
Dichloro-2,2-difluoroethane and its isomers also have toxicity (toxicity to the genital organs) and solubility of high-density polyethylene. On the other hand, 1,1-dichloro-1-fluoroethane and isomers thereof dissolve high-density polyethylene even when used alone, and give high-quality yarn. However,
These solvents are very easy to thermally decompose, and even if they are rapidly dissolved by an extruder, they release a large amount of hydrogen chloride or hydrogen fluoride and are thermally decomposed to easily produce halogenated oligomers.
These decomposition products cause serious problems such as coloring the product and corroding the spinning device. Furthermore, 1,
With respect to 1-dichloro-1-Furoroetan, the solvent further ozone depletion potential (ODP, O zone D epleti
on P otential) are also beyond the 0.1, there is also a problem that has a high ozone depletion potential. Therefore, 1,1-dichloro-1-fluoroethane and its isomers cannot be used as a flash spinning solvent because they are easily thermally decomposed and have high ozone destruction ability.

The technique proposed in EP 357 364 A4 uses methylene chloride as a solvent,
Cannot be used for the reasons already mentioned. In addition, the method of flash spinning using carbon dioxide and water as a solvent proposed in EP 431801 can be applied to a specific polyolefin having vinyl alcohol having a high hydrophilicity as a copolymer component. However, this solvent is common polyethylene,
Due to the poor ability to dissolve polypropylene, it is almost impossible to obtain fibers with favorable physical properties. Moreover, in this method, it is necessary to use a surfactant substantially in combination, which not only complicates the process, but also causes a problem that the surfactant remains in the obtained fiber and practical properties are deteriorated. There is.

Further, in a proposal using a mixed system of a water-containing organic solvent, such as EP 0414498 A2, it cannot be used because the solvent used has high flammability. Also disclosed in Japanese Patent Application Laid-Open No. 4-185708 is 1,1-dichloro-
In the method of spinning using 2,2,3,3,3-pentafluoropropane and / or a mixture of 1,3-dichloro-1,2,2,3,3-pentafluoropropane and hydrocarbons, Since the hydrocarbons used in the mixture have problems such as flammability and high toxicity, they cannot be put to practical use.

From the above, a solvent that has been proposed so far as a substitute for trichlorofluoromethane for flash spinning is:
It is clear that all of these have unsolved problems, and no satisfactory solvent has been proposed yet which can replace trichlorofluoromethane. The purpose of the present invention is
An object of the present invention is to provide a solvent which can substitute for trichlorofluoromethane or which is better. That is, an object of the present invention is to provide a solvent which is excellent as a solvent for flash spinning of a polyolefin, hardly burns, has low toxicity, and has a low ozone destruction ability. It is another object of the present invention to provide a polymer solution using the solvent. Furthermore,
Another object of the present invention is to provide an improved method for flash spinning a polyolefin, which can provide a three-dimensional fiber having high strength and excellent spreadability using the solvent. Needless to say, the solvent and the solution according to the present invention can be used in other technical fields in which the characteristics can be utilized, for example, as a reaction solvent, a foaming agent, a cleaning agent, and the like used as a substitute for chlorofluorocarbon.

[0019]

Means for Solving the Problems To achieve the above object, the present inventors have conducted enormous research on the screening of solvents, and found that a fiber comparable to a polyolefin three-dimensional fiber by a conventional flash spinning method. Or trial-and-error as to whether a fiber having superior performance was obtained, and as a result, the present invention was able to be reached.

That is, the first invention of the present invention is a mixed solvent consisting essentially of a solvent consisting of bromochloromethane and / or 1,2-dichloroethylene and a cosolvent, wherein the cosolvent is carbon dioxide, hexafluoride. Sulfur fluoride, difluorochloromethane, 1,1,1,2-tetrafluoroethane, 1-
Chloro-1,2,2,2-tetrafluoroethane, 1-chloro-1,1-difluoroethane, 1,1-dichloro-
2,2,3,3,3-pentafluoropropane, 1,3-
One or more members selected from the group consisting of dichloro-1,2,2,3,3-pentafluoropropane, dodecafluoropentane and tetradecafluorohexane, and the proportion contained in the mixed solvent of the cosolvent is 3 to It is a halogen-based solvent characterized by being 65% by weight.

In a mixed solvent composed of a binary solvent consisting essentially of bromochloromethane and 1,2-dichloroethylene and a co-solvent, the proportion of bromochloromethane in the binary solvent is preferably 40 to 75% by weight. .
A preferable ratio contained in the mixed solvent of the cosolvent is 10 to 3
0 wt%. As a stabilizer, propylene oxide,
At least one of the group consisting of 1,2-butylene oxide, nitromethane, a phosphite represented by the structural formula (I), a diphosphite represented by the structural formula (2), and a diphosphite represented by the structural formula (3) It is advisable to include the above in an amount of 0.001 to 5 wt% of the mixed solvent.

[0022]

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[0023]

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[0024]

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The second invention of the present invention is a polyolefin solution prepared at a high temperature and a high pressure, wherein a mixed solvent consisting essentially of a solvent consisting of bromochloromethane and / or 1,2-dichloroethylene and a cosolvent is used as a solvent. The cosolvent used was carbon dioxide, sulfur hexafluoride, difluorochloromethane, 1,1,1,2-tetrafluoroethane, 1-chloro-1,2,2,2-tetrafluoroethane, 1-chloro-
1,1-difluoroethane, 1,1-dichloro-2,2,
Selected from one or more of the group consisting of 3,3,3-pentafluoropropane, 1,3-dichloro-1,2,2,3,3-pentafluoropropane, dodecafluoropentane and tetradecafluorohexane Using a halogen-based solvent characterized in that the proportion contained in the mixed solvent of the co-solvent is 3 to 65 wt%, and wherein the polyolefin solution has a polyolefin concentration of 5 to 25 wt%. is there.

As the polyolefin, polyethylene or polypropylene can be used. Also 1,2-
The trans form in dichloroethylene can be used at 30 to 40% by weight. The third invention of the present invention is a polyolefin solution adjusted at high temperature and high pressure, a reduced pressure orifice,
Pass through the decompression chamber and the spinneret, release to normal temperature and normal pressure area,
In the method for producing a fibrillated polyolefin three-dimensional fiber, a mixed solvent consisting essentially of a solvent consisting of bromochloromethane and / or 1,2-dichloroethylene and a cosolvent is used as a solvent, and the cosolvent is made of carbon dioxide and hexafluoroethylene. Sulfur fluoride, difluorochloromethane, 1,1,
1,2-tetrafluoroethane, 1-chloro-1,2,2
2,2-tetrafluoroethane, 1-chloro-1,1-difluoroethane, 1,1-dichloro-2,2,3,3,3
Pentafluoropropane, 1,3-dichloro-1,2,2
Selected from one or more of the group consisting of 2,3,3-pentafluoropropane, dodecafluoropentane, and tetradecafluorohexane, and the proportion contained in the mixed solvent of the co-solvent is 3 to 65 wt%; A method for producing a three-dimensional polyolefin fiber, wherein the polyolefin concentration in the polyolefin solution is 5 to 25 wt%.

At this time, a mixed solvent composed of a binary solvent consisting essentially of bromochloromethane and 1,2-dichloroethylene and a cosolvent was used as the solvent, and the ratio of bromochloromethane in the binary solvent was 40 to 75 wt. It is good to be%. By this method, the present inventors can obtain a three-dimensional fiber of polyolefin, which is a solvent having a low ozone depleting ability, is significantly higher in strength, and has a good opening property, unlike a conventionally known method. did it.

As described above, it is assumed that the solvent used for flash spinning is an organic solvent which becomes a gas at normal temperature and normal pressure. That is, the polyolefin is dissolved under high temperature and high pressure, then the pressure is once lowered to change the phase from a transparent liquid to an opaque liquid, and then the opaque polymer solution is blown through a spinneret into an atmosphere at normal temperature and normal pressure. At this time, the organic solvent is gasified to form a supersonic gas jet. The polymer is solidified and stretched by the gas jet, and becomes a three-dimensional fiber having high strength.

Accordingly, the properties to be possessed as a flash spinning solvent are widely known as described above, but when examined in more detail, they are as follows. At room temperature and pressure, the polymer should not be dissolved at all, but at a temperature exceeding the melting point of the polymer and at a high pressure far exceeding the normal pressure. A phase change from a transparent liquid to an opaque liquid by a temperature exceeding the melting point of the polymer and not causing thermal degradation,
Especially in the case of flash spinning, LC
ST (L ower C ritical S olution T emperature, lower critical solution temperature) is preferably in the polymer solution with type phase diagram, it is preferable that flash spinning solvent also has an LCST type phase diagram. Moreover, it is preferable to have an LCST type phase diagram, and that the phase change occurs instantaneously. This property is important because flash spinning causes a phase change from transparent to opaque with pressure. As soon as it comes out of the spinneret, it must be gasified.
This means that it must have a boiling point near normal temperature and normal pressure. That is, it must be a low boiling organic solvent. The change before and after the spinneret is approximately an isentropic change. Thus, the spinneret outlet spontaneously becomes a liquid / gas mixture. If it is left as it is, it will not be usable because it will be leaked three-dimensional fiber. However, because the polymer has heat,
The liquid is gasified by this calorific value and becomes a dry three-dimensional fiber. This means that the heat of evaporation of the organic solvent must be adequate. Organic solvents must have good thermal stability because they are exposed to temperatures above the melting point of the polymer. In the present invention, the term "thermal stability" means that it is difficult to perform heat division at a temperature at which a polymer is dissolved. It must be non-flammable or non-flammable because there is electrical equipment that fills a large-capacity enclosed space and is an ignition source in the enclosed space. Since humans often come into contact with the gas filled in the enclosed space, it must be non-toxic. Since the entire flash spinning apparatus becomes a high-pressure apparatus, it is necessary that the solvent be a low corrosive solvent. ODP must be small. Preferably,
Preferably it is less than 0.01.

Of particular importance are low boiling points, LCST type polymer solutions, thermal stability, low flammability, non-toxicity and low ODP. We have a low boiling point, LCST type polymer solution,
Numerous experiments were conducted to find flash spinning solvents that satisfied the six conditions of thermal stability, low flammability, non-toxicity and low ODP.

As a result, bromochloromethane or / and 1,2-dichloroethylene, carbon dioxide, sulfur hexafluoride, difluorochloromethane, 1,1,1,2-tetrafluoroethane, 1-chloro-1, 1-difluoroethane, 1-chloro-1,2,2,2-tetrafluoroethane, 1,1-dichloro-2,2,3,3,3-pentafluoropropane, 1,3-dichloro-1,2,2 2,3,3
Finding that a mixed solvent consisting essentially of one or more co-solvents of the group consisting of pentafluoropropane, dodecafluoropentane and tetradecafluorohexane completely or almost completely satisfies the above six conditions. Was.

Hereinafter, the reason why the solvent and the solution of the present invention satisfy the above-mentioned six conditions particularly required for flash spinning will be described, and further, the characteristics of the solvent and the preferable composition range thereof will be described. In order to avoid complexity, difluorochloromethane is HCFC-22,1,1,1,2-tetrafluoroethane is HFC-134a, 1-chloro-1,1-
Difluoroethane is HCFC-142b, 1-chloro-
1,2,2,2-tetrafluoroethane is HCFC-12
4,1,1-dichloro-2,2,3,3,3-pentafluoropropane is HCFC-225ca and 1,3-dichloro-1,2,2,3,3-pentafluoropropane is HC
FC-225cb, dodecafluoropentane is FC-61
12, Tetradecafluorohexane is abbreviated FC-7114 in the description below. Toxicity AC of bromochloromethane, 1,2-dichloroethylene
The GIH has a TLV of 200 ppm in each case, indicating a high value (that is, low toxicity) as a chloro compound. The TLV of the cosolvent is, for example, 50
It is known to have a very low toxicity, being 00 ppm and up to 1000 ppm for sulfur hexafluoride. TLVs are not specified for other cosolvents, but their toxicity is considered to be very low. Moreover, none of these solvents has been reported to be carcinogenic to humans. Thus, the flash spinning solvents of the present invention composed of these solvents are not completely non-toxic, but have rather low toxicity. Pay attention to gas leakage and ventilation of the place, maintain the controlled concentration in the work place, and use personal protective equipment such as an air line mask when in contact with people. Flammability and thermal stability Since bromochloromethane and 1,2-dichloroethylene may be thermally decomposed when exposed to high temperatures, it is necessary to use a stabilizer or the like as necessary. Many stabilizers have been developed today, but the high temperature and pressure required for flash spinning (typical temperature and pressure are 200 ° C, 200 kg / cm
² )), very few stabilizers are effective.
This is because the use conditions of the solvent are very severe and the stabilizer used here is a solvent stabilizer, so if used in a large amount, after spinning, the stabilizer is concentrated into the yarn, and the yarn is bloomed or bloomed. Because it bleeds.
Therefore, a small amount of a stabilizer which is effective at high temperature and pressure is required. After investigating many stabilizers, it was found that epoxy compounds, nitro compounds, diphosphites and phosphites were effective. In particular, diphosphite showed a high heat stabilizing effect. Further, as a result of a detailed study of the structure of the stabilizer, as a stabilizer, propylene oxide,
It has been found that 1,2-butylene oxide, nitromethane, phosphite represented by structural formula (1), diphosphite represented by structural formula (2), and diphosphite represented by structural formula (3) are particularly excellent. Was.

[0033]

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[0034]

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[0035]

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In the present invention, R¹, R^Two, R^ThreeIs charcoal
Heterogeneous or homogeneous monovalent hydrocarbons with a prime number of 1 to 30
And examples thereof include nC_nH_{n + 1}, Iso
-C _nH_{n + 1}(Where n is an integer from 1 to 30)
You. ), Phenyl group or partially alkyl group
And a benzene ring. Of these combinations
Of which, R¹, R^Two, R^ThreeOne or two are aromatic groups
Is preferable from the viewpoint of increasing thermal stability. Ma
The remaining one or two are aliphatic coals in which n is 8 or more.
Hydrogen is preferred from the viewpoint of improving thermal stability.
R^Four, R^FiveIs a monovalent aliphatic having 8 to 30 carbon atoms
Hydrocarbons, examples of which are nC _nH_{n + 1}, I
so-C_nH_{n + 1}(However, n is an integer from 8 to 30
It is. ). Desirable n is for enhancing thermal stability.
From 12 to 24, more preferably from 16 to 20
You.

These stabilizers may be used alone or together with other stabilizers and additives.
Other stabilizers and additives include dibutyltin malate,
Examples include metal soap, methanol, phenol derivatives, catechol derivatives, methanol, ethanol, methyl acetate, ethyl acetate, β-diketone derivatives, tertiary amines such as pyridine and tributylamine, and N, N-dimethylpyridine derivatives.

Among the stabilizers used in the present invention, diphosphite represented by the structural formula (2) is most effective in reducing the decomposition reaction of the solvent. However, since diphosphite has low solubility in the solvent of the present invention, other stabilizers may be used depending on the process. With respect to the amount used, generally, one or more of the stabilizers of the present invention can be used in an amount of about 0.001 to 5% by weight of the mixed solvent of the present invention. In the case of the epoxy compound and the diphosphite, When the content is 0.001 to 0.1 wt%, a high thermal stability effect can be exhibited. In order to enhance the effect of the stabilizer, the bromochloromethane, 1,2-dichloroethylene and the cosolvent used in the present invention are preferably substantially pure. In particular, the amount of free acids such as hydrogen chloride, hydrogen bromide and water is preferably as low as possible, particularly preferably 10 ppm or less.

The cosolvent used in the present invention is HCFC-14.
Except for 2b, all are completely nonflammable solvents. Therefore,
One of the important meanings of mixing a cosolvent with the two chloro compounds is to significantly reduce the flammability of the solvent of the present invention. Although HCFC-142b has flammability, it has a narrow explosion range of 9 to 15 v% and is a flame-retardant substance. Therefore, the solvent obtained using HCFC-142b is flame-retardant and can be used if it is produced in a completely closed process.

Bromochloromethane is a completely non-flammable solvent, known as a strong digestive agent called CB,
It is a solvent with a very high combustion suppression effect. Therefore, a mixed solvent of bromochloromethane and a co-solvent except HCFC-142b is completely nonflammable with an arbitrary solvent composition. 1,2
-Dichloroethylene has an explosion range of 9.7 to 12.8v
%, Which is a so-called flame retardant substance. 1,2-Dichloroethylene has a very high lower explosion limit, and can be completely incombustible or very easily mixed with a nonflammable solvent.
It can be a flame retardant solvent. As such a nonflammable solvent, the cosolvent of the present invention is very suitable. In order to reduce or eliminate flammability, the solvent composition of the present invention is very useful, and the preferable proportion of 1,2-dichloroethylene is 70 to 90% by weight, particularly preferably 70 to 90% by weight. ~ 80 wt%.

By combining 1,2-dichloroethylene and bromochloromethane, it is possible to prepare a solvent which is completely nonflammable and has excellent thermal stability at the same time. The explosion range can be reduced by adding a nonflammable substance to the flammable solvent. Then, in order to improve the flammability of 1,2-dichloroethylene, bromochloromethane was used as a non-combustible substance. Bromochloromethane is a low toxic and excellent solvent for polyolefins under high temperature and pressure as described later. Moreover, because it has a bromine atom with a high combustion suppressing effect, it is extremely excellent as a combustion suppressing substance with flash spinning in mind.
The only one. For example, chloroform, carbon tetrachloride, chloroform, methylene bromide, bromoform and the like also have a high combustion suppressing effect. However, none of these compounds have high toxicity, so flash spinning cannot be used.

When the flammability of a mixed solvent of a binary solvent of 1,2-dichloroethylene and bromochloromethane and a cosolvent was examined, it was found that the proportion of bromochloromethane in the binary solvent was approximately 40% by weight, indicating that the mixture was completely nonflammable. I understood. Therefore, in order to prepare a completely non-combustible two-component solvent, the proportion of bromochloromethane in the two-component solvent must be 40% by weight or more.

By the way, 1,2-dichloroethylene is superior in thermal stability to bromochloromethane. Therefore, we want to minimize the amount of bromochloromethane used. On the other hand, when 1,2-dichloroethylene is mixed with bromochloromethane to improve thermal stability, thermal stability equal to or higher than that of trichlorofluoromethane can be secured. This is due to the effect of 1,2-dichloroethylene suppressing the thermal decomposition of bromochloromethane, as well as the diluting effect caused by reducing the abundance ratio of bromochloromethane in the solvent. That is, 1,2-dichloroethylene can significantly suppress the generation of decomposition products due to the presence of the double bond.
In order to obtain such excellent thermal stability, the proportion of bromochloromethane in the binary solvent of bromochloromethane and 1,2-dichloroethylene must be 75% by weight or less. Preferably, it is at most 60 wt%, more preferably at most 50 wt%.

Therefore, in order to obtain a completely nonflammable solvent having excellent thermal stability at the same time, the proportion of bromochloromethane in the binary solvent of 1,2-dichloroethylene and bromochloromethane is 40 to 75% by weight. Preferably, 4
The content is 0 to 60% by weight, more preferably 50 to 60% by weight.
In addition, the mixing ratio of the cosolvent in the mixed solvent of the present invention composed of the binary solvent of 1,2-dichloroethylene and bromochloromethane and the cosolvent is generally 3 to 50% by weight.
It is. In particular, it is preferably 5 to 30% by weight, and more preferably 10 to 30% by weight.

Although bromochloromethane has a low thermal stability, it can be practically used by adjusting the solution using an extruder having a short residence time at a high temperature and a high pressure, or by setting a low spinning temperature. Can be used without problems. Boiling point carbon dioxide, HCFC-22, HFC-134a, HC
FC-142b and HCFC-124 are gases at normal temperature and normal pressure. Thus, one of the important implications of mixing these gaseous cosolvents with the two chloro compounds is:
It is to significantly lower the boiling point of the flash spinning solvent of the present invention.

The boiling point is preferably 60 ° C. or lower, more preferably 50 ° C. or lower, as long as gasification occurs at normal temperature and normal pressure. This boiling point is a function of the solvent composition in the mixed solvent, and can be freely adjusted by changing the mixing ratio of the above-mentioned gaseous cosolvent. Bromochloromethane has a boiling point of 68 ° C. In addition, 1,2-dichloroethylene has two geometric isomers, a trans form and a cis form.
The boiling point of trans-1,2-dichloroethylene is 47.
7 ° C., the boiling point of cis-1,2-dichloroethylene is 6
0.25 ° C. Therefore, by changing the mixing ratio of the gaseous co-solvent, the solvent of the present invention can be adjusted to a desired boiling point of 60 ° C. or lower.

HCFC-225ca (boiling point: 51.1)
° C), HCFC-225cb (boiling point: 56.1 ° C), F
The cosolvents of C-6112 (boiling point: 30 ° C.) and FC-7114 (boiling point: 56 ° C.) have slightly higher boiling points, but the boiling point is substantially 60 ° C. or lower even when these liquid cosolvents are used. A solvent can be obtained. The spun yarn was not wet when spun using the solvent of the present invention. Cloud Point Curve The solvent used in the present invention becomes an LCST-type polymer solution when the polyolefin is dissolved therein. As described above, the basic principle of flash spinning is that a high-temperature and high-pressure polymer solution is decompressed and phase-separated to form an opaque liquid composed of at least two phases of a polymer and a solvent, followed by spinning. Therefore, the temperature and pressure of the cloud point that can be determined by changing from a transparent liquid to an opaque liquid are extremely important. This cloud point is also the point at which phase separation occurs. The cloud point is indicated by the temperature and pressure at which the liquid changes from transparent to opaque.
In polymer chemistry, a diagram in which this cloud point is plotted on temperature / pressure coordinates is called a cloud point curve. The suitability of the solvent for flash spinning can be determined from the position of the cloud point curve on the temperature / pressure coordinate plane.

In the present invention, the cloud point curve was measured by the apparatus shown in FIGS. FIG. 1 is an explanatory view of the entire apparatus, and FIG. 2 is an explanatory view of an optical cell container for measuring a cloud point. That is, two optical windows 2 are provided in an optical cell container (internal dimensions, diameter 40 mm × length 83 mm, volume about 100 cm ³ ) 1 so that the inside can be observed through light. The length of the optical path through which light passes is 18 mm because the thickness of the glass 14 of the optical window 2 is 9 mm and two are provided, and the thickness of the solution is 40 mm, so that the total length is 58 mm. The optical cell container 1 has a built-in stirring blade 13 for stirring the inside of the container at about 180 rpm until the polymer is dissolved.
The structure of the stirring blade 13 is such that two stirring blades are installed, and the axis of the portion corresponding to the optical window is “co” so as not to disturb the optical observation.
It is shaped like a letter. Further, a thermometer 4 is inserted so as to be in direct contact with the solution in the optical cell container. The pressure gauge 5 is provided in the middle of the pipe 9 and detects the pressure in the optical cell container. A plunger-type pressure regulator is provided via a pipe 9 to adjust the liquid pressure in the optical cell container. Further, a pipe 10 is provided for venting the gas in the optical cell container and for pushing out the liquid in the container. Further, the entire optical cell container is covered with an aluminum casting heater, and the control circuit temperature is controlled.

The method for measuring the cloud point is as follows. First, the polymer and the solvent were weighed so that the polymer concentration became a predetermined concentration and the inside of the container became a liquid seal, and was supplied to the container. Preparation of the polymer solution was performed on the basis of volume% for the purpose of simplifying the experiment. When a gaseous co-solvent was used, the mixed solvent was prepared in a predetermined ratio in a stainless steel cylinder of 300 cm ^{3 at} a predetermined ratio, and introduced into the optical cell container by pressurization with nitrogen gas. When a liquid cosolvent was used, it was introduced into the optical cell container as it was after the adjustment. In each case, a predetermined amount of the polymer was placed in the optical cell container, the optical cell container was evacuated to avoid the influence of air, and then the mixed solvent was introduced. The pressure in the vessel then rises as it is heated and the liquid expands. The heating rate was 4.5 ° C./min. The liquid condition is 50kg / cm ² , 1
After the temperature reached around 05 ° C., the pressure was not adjusted until the polymer was completely dissolved. In this way, the polymer that has reached the vicinity of the melting point of the polymer starts to be dissolved in the solvent. In this state, a polymer solution was prepared.

Next, the measurement of the cloud point is started. While increasing the temperature, the pressure was changed by a plunger type pressure regulator, and the point at which the solution started to become cloudy, that is, the cloud point, was visually observed. With 1,2-dichloroethylene alone, this cloud point curve exists at a very low pressure in the temperature range of flash spinning and cannot be observed unless the temperature is considerably high. For example, when a high-density polyethylene having a weight-average molecular weight of 102000 is used, 220 ° C.
In the line connecting the ^{62kg / cm 2, 83kg / cm} 2 at 230 ° C., a barely level cloud point curve is observed (the pressure of the cloud point with the polymer concentration is decreased, a practical polymer concentration cloud point The curve cannot be observed). The result is
1,2-dichloroethylene is a good solvent for polyolefin under high temperature and high pressure. Further, bromochloromethane shows higher solubility than 1,2-dichloroethylene, that is, it is a very good solvent for polyolefin under high temperature and high pressure. For example, when the above-mentioned high-density polyethylene is used, 2 v%
Even at very low concentrations, no cloud point can be ascertained.

On the other hand, the co-solvent cannot dissolve the polymer in the temperature range of flash spinning. Completely poor solvent. Therefore, by combining the two chloro compounds, which are good solvents for polyolefins, and the cosolvent under high temperature and pressure, a cloud point curve could be brought to a position suitable for flash spinning. Such a preferable cloud point pressure is about 80 to 300 kg / cm ^{2 at} 200 ° C., particularly preferably about 120 to 230 kg / cm ² . When such a preferable cloud point pressure was converted into a preferable mixing ratio of the cosolvent, it was generally 3 to 65% by weight for all the chloro compounds. In particular, it is preferably 5 to 30% by weight, and more preferably 1 to 30% by weight.
It was 0 to 30% by weight. To illustrate a particularly preferred cosolvent amount for each cosolvent, carbon dioxide is 10 to 20 wt%,
5 to 20 wt% sulfur hexafluoride, 15 to HCFC-22
30wt%, HFC-134a is 15 ~ 25wt%, HCF
20-40 wt% for C-142b, 1 for HCFC-124
5-30 wt%, HCFC-225ca is 30-65 wt%
%, HCFC-225cb is 30 ~ 65wt%, FC-6
112 is 15-30 wt%, FC-7114 is 15-30%
wt%. The preferred amounts of these co-solvents slightly vary depending on the type of polymer and the degree of polymerization, but generally fall within the ranges shown here. Of course, two or more of these cosolvents may be used as a mixture, or a new solvent may be partially added separately. Further, with respect to 1,2-dichloroethylene, although the cloud point was slightly lower in the cis-form than in the cis-form, the difference between the trans-form and the cis-form was not a substantial problem.

FIGS. 3 and 4 show examples of the cloud point curve. 3) A) bromochloromethane / carbon dioxide (85/15 wt%) and B) bromochloromethane / HFC-134a (80/20 wt%) and (75/2).
5 shows a cloud point curve of a solvent composition of 5 wt%). The upper region of each cloud point curve has one phase, and the lower region has two phases. The polymer is a high-density polyethylene having a density of 0.97 g / cm ³ and a weight average molecular weight of 102000 (dispersion degree: 6.14), and the polymer concentration of the solution is 18 v%.
On the other hand, FIG. 4 shows trans-1,2-dichloroethylene / bromochloromethane / carbon dioxide (45/40/15 wt.
%), (50/35/15 wt%), (50/40/10
3 shows cloud point curves of three solvent compositions (wt%). The upper region of each cloud point curve has one phase, and the lower region has two phases. The polymer is a high-density polyethylene having a density of 0.97 g / cm ³ and a weight average molecular weight of 102000 (dispersion degree: 6.14), and the polymer concentration of the solution is 18 v%.

As a matter of course, it was also confirmed that the position of the cloud point curve changes depending on the composition ratio of the two chloro compounds and the cosolvent. This indicates that the thermodynamic properties of the polymer solution change depending on the solvent composition ratio. Cloud point curves were obtained for other compositions and other cosolvents, and a spinning experiment was performed using the results to find an appropriate solvent and its composition.

Bromochloromethane or / and 1,2
-Sulfur hexafluoride in dichloroethylene, FC-6112,
Mixing FC-7114 at room temperature under autogenous pressure does not result in a uniform solution. However, a uniform solution can be obtained by increasing the temperature or / and pressure. Therefore, when preparing a uniform solution, it is necessary to control the temperature and pressure. Generally, a uniform solution can be obtained at a temperature of 140 ° C. or higher for bromochloromethane and at a temperature of 80 ° C. or higher for 1,2-dichloroethylene. ODP The life of halogen compounds in the atmosphere is determined by OH
It is an active chemical species called a radical. It is formed by the reaction of oxygen and organic substances under ultraviolet light from the sun.
Since bromochloromethane is a chloro compound having a hydrogen atom, it reacts very easily with OH radicals in the atmosphere. Therefore, the ODP of bromochloromethane is substantially zero. Since 1,2-dichloroethylene has a double bond, it is difficult to react with OH radicals and remain in the atmosphere. Therefore, the lifetime of 1,2-dichloroethylene in the atmosphere is short. Since ODP is required in consideration of the life in the atmosphere, specific fluorocarbon and carbon tetrachloride> alternative fluorocarbon> methylene chloride (ODP is 0.003)> halogen compound having a double bond (for example, 1, 2-dichloroethylene). Therefore, the ODP of 1,2-dichloroethylene is substantially zero.

On the other hand, carbon dioxide, sulfur hexafluoride, HFC
Since -134a, FC-6112, and FC-7114 have a non-fluorocarbon structure, the ODP is naturally 0. Therefore,
Since the solvent of the present invention using these cosolvents is substantially composed of a solvent having no ozone depleting ability, it can be used without any problem in the future. To date, flash spinning solvents using several low ODP alternative freons have been disclosed, but all of these solvents have ozone depletion capabilities, albeit at low levels. With regulations on fluorocarbons increasing day by day, it is clear how important and excellent the present invention is to provide a solvent that has no ozone depletion capability and is nonflammable and low toxic. On the other hand, HCFC-22, HCF
C-142b, HCFC-124, HCFC-225c
a, Since the hydrochlorofluorocarbon of HCFC-225cb has an ODP on the order of 0.01, it may not be able to be used within 20 years due to stricter regulations.

From the above-mentioned limitations, considerations, and experimental results, the preferred co-solvent mixing ratio is 5 to 30 wt%.
It is. Particularly preferably, it is 10 to 30% by weight. In addition, since ODP is substantially zero among the cosolvents, carbon dioxide, sulfur hexafluoride, HFC-134a, FC-6
112 and FC-7114 are preferable, and carbon dioxide and HFC-134a, which are uniform and highly operable cosolvents, are particularly preferable.

Incidentally, 1,2-dichloroethylene undergoes an isomerization reaction at high temperature and high pressure. Such an isomerization reaction
Considering the recovery of the solvent, it means that the ratio of the isomer changes with each recovery. However, under the conditions of flash spinning, it was found that the ratio of the trans-form became almost equilibrium when the ratio was 30 to 40% by weight. Therefore, if the ratio of isomers is controlled within this range, regardless of the number of recovery times,
A fixed isomer ratio of 1,2-dichloroethylene can be handled. This control is very important for stable production. When the solvent of the present invention is used at a temperature of 100 ° C. or lower, this isomerization reaction hardly occurs. Therefore, even if 1,2-dichloroethylene having any isomer ratio is used, the use and recovery can be performed with good stability. Can be repeated.

The three-dimensional fiber spun using the flash-spinning solvent of the present invention determined as described above can be formed into a good nonwoven sheet, which is excellent in opening property, strength and strength without wetting. Was something. The weight ratio between the flash spinning solvent and the polyolefin used in the method for producing a polyolefin three-dimensional fiber of the present invention is 5 to 25 wt%. Within this range, a three-dimensional fiber of polyolefin having excellent spreadability and high strength can be easily produced. 5
If it is less than wt%, it becomes a pulp-like or low-strength yarn,
If the content is 5 wt% or more, the openability of the yarn becomes low, which is not preferable in any case. More preferably, 10 to 20 wt%
It is.

As the polyolefin, polyethylene,
Examples include polypropylene and polymethylpentene-1. The polyethylene is most preferably high-density polyethylene, and the density is 0.94 g / cm ³ or more. Further, it is preferable that the copolymer component maintain the above density at 15 wt% or less. The polypropylene preferably contains about 85 wt% or more of isotactic polypropylene, and about 15 wt% or less of other polypropylene or
A copolymer component such as ethylene and butene may be contained. Further commonly known polymer additives, light stabilizers,
Lubricants, nucleating agents, crosslinkers, plasticizers, fillers, and the like may be included in the polymer.

The apparatus used in the present invention may be provided with a dissolution adjusting device and a spinning device including a reduced-pressure orifice, a reduced-pressure chamber, and a spinneret. Prior to this, there are a device for opening and dispersing the three-dimensional fiber, a moving conveyor device for forming the opened and dispersed three-dimensional fiber into a sheet, and a winding machine for winding the formed sheet. The sheet forming section is housed in a closed box, and the solvent gas in the box is recovered. The solution adjusting device may be an autoclave device or an extruder. Alternatively, a conventionally known device can be used.

[0061]

The present invention will be described with reference to the following examples.
This example is for specifically explaining the present invention, and does not limit the scope of the claims of the present invention.

Example 1 Melt index was 0.7
82.1 g of high-density polyethylene of No. 8 and 613 g of a mixed solvent of bromochloromethane / carbon dioxide (85/15 wt%)
Was charged into an autoclave, and (polymer concentration: 11.8
The autoclave was heated while rotating the propeller-type stirrer to dissolve the high-density polyethylene. The solution was further heated, the solution pressure was increased, and the entire polymer was dissolved. After dissolution, the solution was discharged from the discharge nozzle below the autoclave so that the solution pressure did not exceed 300 kg / cm ² , and the pressure was maintained at approximately 250 kg / cm ² . When the temperature of the solution reached 200 ° C., the nitrogen gas introduction valve at the top of the autoclave was opened, nitrogen pressurization of 258 kg / cm ² was performed, and the discharge valve at the bottom of the autoclave was quickly opened. Next, the solution was passed through a reduced pressure orifice (diameter 0.65 mm, length 5 mm) and led to a decompression chamber (diameter 8 mm, length 40 mm), and a spinneret (introduction angle 60 from the decompression chamber to the nozzle).
°, a nozzle diameter of 0.5 mm, a length of 0.5 mm, and a circular groove of 3.3 mmφ and a depth of 3 mm outside the nozzle. ) And released into the atmosphere. The spread yarn was made at a position about 20 to 40 mm away from the spinneret by applying it to a vinyl chloride plate inclined at about 45 °. The spread fiber in the spread state was received by a 10-mesh wire net and collected. The pressure in the decompression chamber is 174 kg
/ Cm ² . The spinning speed was 279 m / s.

The obtained fiber is an unopened yarn having a fineness of 97d,
It is a three-dimensional fiber having a good form with a tensile strength of 6.0 g / d, a tensile elongation of 37%, a specific surface area of 24 m ² / g, an open fiber size of 95 d, a tensile strength of 5.8 g / d, and a tensile elongation of 34%. Was.

Comparative Example 1 Example 1 was repeated using trichlorofluoromethane as a solvent at a polymer concentration of 12.5 wt%. The pressure in the vacuum chamber was 73 kg / cm ² . The spinning speed was 159 m / s. The obtained fiber is an unopened yarn having a fineness of 99 d and a tensile strength of 5.4 g /
d, tensile elongation 27%, specific surface area 21.2 m ² / g.

That is, the spinning speed of 279 m /
The spinning speed of Comparative Example 1 is only 159 m / s as compared with s. This indicates that the use of the solvent according to the present invention makes it possible to spin at a remarkably high speed as compared with the conventional production method. The ability to increase the spinning speed
Furthermore, it means that a higher drawn yarn can be obtained than before. This is evidenced by the fact that the tensile strength and elongation values of the fiber of Comparative Example 1 are inferior to the respective values of Example 1.

[Examples 2 to 5] Under the same conditions as in Example 1,
The effect of the pressure in the vacuum chamber on the physical properties of the spun yarn was investigated. Table 1
Shows the results of the spinning. The number of free fibrils was measured as follows. In other words, the sampled spread yarn is gently sandwiched between glass plates, and the optical microscope of 1.6 times the objective lens and 10 times the eyepiece is moved in the fiber width direction, and the individual yarns in the field of view are moved one by one. The number is counted and converted to the number of free fibrils per 100 denier.

The spread yarn was obtained by placing a copper plate inclined at about 25 ° at a position of about 25 mm from the spinneret and colliding a gas jet containing fibers with the copper plate.
In the table, the scale of the evaluation of the spreadability is "○", the number of free fibrils is 300/100 denier or more, and "△" is between 100 to 300/100 denier, and "x". For example, it is 100/100 denier or less. If "x", it indicates that it cannot be used.

The obtained fiber was a good quality three-dimensional reticulated fiber having excellent spreadability and high strength.

[0069]

[Table 1]

Example 6 By changing only the solvent composition,
With the polymer and polymer concentration of Example 1 fixed,
Using the spinning apparatus of Example 1, a reticulated fiber was produced. The ratio of bromochloromethane / carbon dioxide is 90.6 / 9.4
In wt%, the strength is 4.8 g / d, the specific surface area is 36 m ² / g,
At 80/20, at 5.2 g / d and at 70/30 wt%,
5.0 g / d of reticulated fiber was obtained. Each of these reticulated fibers exhibited good spreadability.

[Example 7] By changing only the polymer concentration and keeping the polymer and solvent composition of Example 1 fixed,
Using the spinning position of Example 1, a reticulated fiber was produced. When the polymer concentration is 7.0 wt%, the strength is 3.4 g / d, 20.
At 5 wt%, 5.4 g / d reticulated fiber was obtained. Each of these reticulated fibers exhibited good spreadability.

Example 8 The melt index was 0.7
81.2 g of high-density polyethylene and bromochloromethane / HFC-134a (78/22 wt%) mixed solvent 6
57 g was charged into an autoclave, and (polymer concentration 1
(1.0 wt%) The autoclave was heated while rotating the propeller type stirrer to dissolve the high density polyethylene. The solution was further heated, the solution pressure was increased, and the entire polymer was dissolved. After dissolution, the solution was discharged from the discharge nozzle below the autoclave so that the solution pressure did not exceed 300 kg / cm ² , and the pressure was maintained at approximately 270 kg / cm ² .
When the temperature of the solution reached 200 ° C., the nitrogen gas introduction valve was opened, nitrogen pressurization at 270 kg / cm ² was performed, and the discharge valve at the bottom of the autoclave was quickly opened. Then
The solution was passed through a decompression orifice (diameter 0.65 mm, length 5 mm) and led to a decompression chamber (diameter 8 mm, length 40 mm), and a spinneret (introduction angle from the decompression chamber to the nozzle 60 °, nozzle diameter 0.1 mm). 5 mm, a length of 0.5 mm, and a circular groove of 4.0 mmφ and a depth of 3 mm outside the center of the nozzle) and released into the atmosphere. Spreading yarn is about 20 ~ from spinneret
It was made by hitting a vinyl chloride plate inclined about 45 ° at a position 40 mm away. The spread fiber in the spread state was received by a 10-mesh wire net and collected. The pressure in the decompression chamber was 159 kg / cm ² . The spinning speed was 206 m / s.

The obtained fiber was an unopened yarn having a fineness of 126.
d, tensile strength 6.6 g / d, tensile elongation 36%,
Specific surface area 15 m ² / g, fineness of spread yarn 123 d, tensile strength 6.5 g / d, tensile elongation 20%, fiber width 3.5
It was a well-formed reticulated fiber of about 6 cm.

Examples 9 to 11 Under the same conditions as in Example 8, the effect of the pressure in the vacuum chamber on the spun yarn properties was examined.
Table 2 shows the spinning results. However, the spinneret has an introduction angle of 60 ° from the decompression chamber to the nozzle, a nozzle diameter of 0.5 mm, a length of 0.5 mm, and a circular groove of 3.3 mmφ outside the nozzle and a depth of 3 mm around the nozzle. Changed to

The obtained fiber was a good three-dimensional reticulated fiber having excellent spreadability and high strength.

[0076]

[Table 2]

Example 12 Reticulated fibers were produced using the spinning apparatus of Example 8 while changing only the solvent composition and fixing the polymer and the polymer concentration of Example 8. The ratio of bromochloromethane / HFC-134a is 90 /
At 10 wt%, the strength is 4.2 g / d, at 85/15 wt%, 5.8 g / d, and at 70/30 wt%, 5.2 g / d.
Was obtained. Each of these reticulated fibers exhibited good spreadability.

Example 13 Reticulated fibers were produced using the spinning apparatus of Example 8 while changing only the polymer concentration and keeping the polymer and solvent compositions of Example 8 fixed. When the polymer concentration is 7.2 wt%, the strength is 3.4 g / d, 2
At 0.5 wt%, 5.8 g / d of reticulated fiber was obtained.
Each of these reticulated fibers exhibited good spreadability.

[Examples 14 to 29] In the same manner as in Example 1, spinning was performed using solvents having various solvent compositions. Tables 3 and 4 show the results.

[0080]

[Table 3]

[0081]

[Table 4]

In the table, DCE is the transformer-1, 2
-Dichloroethylene, BCM refers to bromochloromethane. HCFC-225 consists of HCFC-225ca and H
Figure 2 shows a 50/50 wt% mixture of CFC-225cb.

Example 30 The melt index was 0.1.
81.7 g of 78 high density polyethylene, trans-1,
2-dichloroethylene / bromochloromethane / carbon dioxide (50/35/15 wt%, in this case trans-1,
The ratio of 2-dichloroethylene / bromochloromethane is
613 g of a mixed solvent of 58.8 / 41.2 wt%) was charged into an autoclave, and the polymer concentration was 11.8 wt%.
%) The autoclave was heated while rotating the propeller type stirrer to dissolve the high density polyethylene. The solution was further heated, the solution pressure was increased, and the entire polymer was dissolved. After dissolution, the solution pressure is not to exceed 300 kg / cm ^2, keeping the solution was drained pressure from the discharge nozzle of the autoclave lower part 200~300kg / cm ^2. When the temperature of the solution (spinning temperature) reached 200 ° C., the nitrogen gas introduction valve at the top of the autoclave was opened, pressurization at 250 kg / cm ² was performed, and the discharge valve at the bottom of the autoclave was quickly opened. The solution was then pumped through a vacuum orifice (diameter 0.65).
mm: 5 mm length) and pass through a vacuum chamber (diameter 8 mm, length 40)
mm) and a spinneret (introduction angle of 6 ° from the decompression chamber to the nozzle, nozzle diameter 0.5mm, length 0.5mm, 3.3mmφ around the nozzle, a circular groove of 3mm depth outside) And released into the atmosphere. The spread yarn was made at a position about 20 to 40 mm away from the spinneret by applying it to a vinyl chloride plate inclined at about 45 °. The spread fiber in the spread state was received by a 10-mesh wire net and collected.

The obtained fiber is white, and is an unopened yarn having a fineness of 84d, a tensile strength of 6.5 g / d, and a tensile elongation of 3
9%, a specific surface area of 35 m ² / g, fineness of the opened fiber was 85 d, tensile strength was 6.5 g / d, and tensile elongation was 32%. Example 30 was repeated with the spinning temperature set to 215 ° C., but the obtained fiber was also white in the same manner as in Example 1, and showed the same mechanical physical properties. However, bromochloromethane / carbon dioxide (85 / 15wt
%) And the spinning temperature was set at 215 ° C., the resulting fiber exhibited the same mechanical properties as in Example 1, but was colored gray due to the decomposition product of the solvent.

Further, a test of combustibility with a mixed gas with air was conducted. The solvent shown in Example 30 was nonflammable in any mixture composition with air. However, for comparison, 1,2-dichloroethylene / carbon dioxide (85/1
The same combustion test was conducted with the composition of
When ignition energy of 000 mJ or more was applied, combustion occurred depending on the mixed composition of air.

[Example 31] The spinning temperature was increased to 215 ° C.
Example 1 was repeated. The resulting yarn is slightly blackened
Was colored. Similarly, propylene oxide is added to the spinning solvent.
, 1,2-butylene oxide, nitromethane, tri
Phenyl phosphite, dinonyl phenyl phosphite
, Trilauryl phosphite, R^FourIs nC₁₈H₃₇so
Diphosphite represented by a certain structural formula (2) (manufactured by Asahi Denka
PEP-8F) or R^FiveIs nC₁₂H _{twenty five}~ NC_Fifteen
H₃₁Is a structural formula that is randomly attached to a range of
Diphosphite represented by (3) (MARK-
1500) to the solvent at 0.1 wt% and then spinning
did. Yarns obtained with these stabilizers are completely colored
I didn't. In particular, PEP-8F and MARK-15
Regarding 00, even when using 0.025 wt%,
I didn't.

For comparison, other stabilizers were investigated. The coloring property was examined at a concentration of 0.1% by weight with respect to the solvent. Zinc stearate, barium stearate, methanol, dibutyltin dilaurate, tributylamine, methyl acetate, catechol and the like were examined, but coloring was hardly improved.

Examples 32 to 34 Spinning was performed using isotactic polypropylene instead of high-density polyethylene. In Example 32, a melt flow rate of 1.53 was used, and in Examples 33 and 34, a polypropylene having a melt flow rate of 2.38 was used. Spinning is 21
Performed at 5 ° C., and as a stabilizer, PEP-8F of Example 31
Was added to the solvent in an amount of 0.5% by weight. Table 5 shows the results.

[0089]

[Table 5]

Comparative Example 2 The experiments of Examples 1, 14, 16, 19, 22, 28 and 29 were repeated using methylene chloride as a good solvent. The yarn was wet when methylene chloride was used. For example, when the conditions of Example 1 were used, the residual amount of methylene chloride in the yarn immediately after spinning was about 16% by weight based on the dry yarn. On the other hand, in each case, dried yarn was obtained in Examples of the present invention.

When the polymer concentration was increased to 18% by weight, the yarn was dried.
Met. For example, when the conditions of Example 1 were used, the number of free fibrils was 130. By the way, Example 1
Had a free fibril count of 310. Example 14,
The same experiment was repeated with the recovery of 15 solvents. 1,2
The proportion of the trans form of dichloroethylene gradually decreases as the number of spinning increases, and the proportion of the trans form becomes 30 to 4;
It became almost constant in the range of 0 wt%. Further, Examples 14 and 15 were repeated using 1,2-dichloroethylene having a trans / cis ratio of 35/65 wt%, but the trans / cis ratio hardly changed.

Example 35 In Example 35, the result of using the solvent of the present invention in the production of a regenerated cellulose polymer membrane having improved blood affinity as an example in which the present invention was applied to other than flash spinning. . C ₁₂ H ₂₅ (OCH ₂ CH
₂ ) _n OCH ₂ COOH (n is 4.5 on average)
32 g, 0.01 g of 4.4-dimethylaminopyridine,
0.13 g of dicyclohexylcarbodiimide was added to bromochloromethane / HFC-134a (85/15 wt%) 35
Dissolved in 0 cm ³ . A bundle (about 7,000 pieces) of regenerated cellulose hollow fiber membranes (0.2 mm in inner diameter, 0.01 mm in thickness, 30 cm in length) was shaken and moved up and down for 30 minutes from time to time. The treated regenerated cellulose hollow fiber membrane bundle was immersed in methanol for 24 hours and dried at room temperature under reduced pressure to obtain a hollow fiber membrane bundle (1) in which the surface of the hollow fiber was esterified.

Further, for comparison, 1,1,2-trichloro-containing specific fluorocarbon currently used industrially was used.
1,2,2-trifluoroethane / acetone (87.5 /
12.5 wt%) with bromochloromethane / HFC-134
a (85/15 wt%). The esterified hollow fiber membrane bundle thus obtained is referred to as (2). The obtained esterified regenerated cellulose hollow fiber membranes (1) and (2) and the untreated regenerated cellulose hollow fiber membrane (3)
Was incorporated into a dialyzer to perform extracorporeal circulation by a dog.
The dog is a beagle dog weighing about 10 kg, 100 cm ³ / mi
n blood was drawn from the shunt added to the neck and flowed through the dialyzer. Prior to extracorporeal circulation, the dialyzer was washed with a physiological saline solution, and then the dialyzer and the blood circuit were filled with a physiological saline solution containing 5 U / cm ³ of heparin, and then blood was flowed. Blood was collected at the dialyzer inlet, and the white blood cell count was measured.
Table 6 shows the values at 15 minutes and 30 minutes after dialysis, where the leukocyte count immediately before dialysis was taken as 100.

[0094]

[Table 6]

By using the solvent of the present invention, a regenerated cellulose hollow fiber membrane having a blood affinity equal to or higher than that of a 1,1,2-trichloro-1,2,2-trifluoroethane / acetone solvent can be obtained. It turns out to give.

[0096]

The solvent and solution according to the present invention have a low ozone depleting ability and can be used as a new alternative CFC solvent and solution. In particular, the solvent and the solution of the present invention are extremely useful as a solvent for flash spinning, a detergent, a foam, a gas for producing a hollow fiber, a reaction solvent, and the like. In particular, it is important as a solvent for flash spinning.

By using the solvent according to the present invention, it is possible to obtain a socially useful three-dimensional fiber having a strength and opening property equal to or higher than that of using trichlorofluoromethane without destroying the ozone layer. can get. Utilizing the present invention, the three-dimensional fiber of polyolefin is much more excellent in opening property than flash spinning method using a solvent that can replace conventionally known trichlorofluoromethane, and also has high strength, which is always stable. Maintain productivity and can be easily manufactured. This industrial significance has enormous value.

[Brief description of the drawings]

FIG. 1 is a schematic view of an optical cell container-based measuring device for measuring the cloud point of a polymer solution.

FIG. 2 is a schematic view of an optical cell container used for cloud point measurement.

FIG. 3 is a graph showing an example of a cloud point curve of the polymer solution of the present invention, wherein A) bromochloromethane / carbon dioxide (85/15 wt%) and B) bromochloromethane / HF.
C-134a (80/20 wt%) and (75/25 wt%
%) Is a graph showing a cloud point curve of the solvent composition of (%).

FIG. 4: trans-1,2-dichloroethylene / bromochloromethane / carbon dioxide (45/40/15 wt%),
(50/35 / 15wt%), (50/40 / 10wt%)
3 is a graph showing a cloud point curve of the solvent composition of Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical cell 2 ... Optical window 5 ... Pressure gauge 7 ... Light source 8 ... Receiver

Continued on front page (31) Priority claim number Japanese Patent Application No. 3-288766 (32) Priority date November 5, 1991 (11.5 January 1991) (33) Priority claim country Japan (JP) (31) Priority claim number 4-4538 (32) Priority date January 14, 1992 (199.2.1.14) (33) Priority claim country Japan (JP) (31) Priority claim number 4-4780 (32) Priority date January 14, 1992 (199.2.1.14) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-4936 (32) Priority Date January 14, 1992 (199.2.1.14) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-4938 (32) Priority date January 14, 1992 (199.2.1.14) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-19096 (32) Priority date February 4, 1992 (1992.2.4) (33) Priority Country Japan (JP) (72) Inventor Yoshiaki Nakayama 6-4100 Asahicho, Nobeoka-shi, Miyazaki Prefecture Asahi Kasei Kogyo Co., Ltd. (72) Inventor Kenji Kaneyoshi 6-4100 Asahicho, Nobeoka City, Miyazaki Prefecture Asahi Kasei Kogyo Co., Ltd. (56) References JP-A-5-263310 (JP, A) JP-A-5-263308 (JP, A) JP-A-4-352809 (JP, A) JP-A-2-247143 (JP, A) JP-A-6-502449 (JP, A) JP-A-5-505183 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) C07C 19/075 C07C 21/073 D01D 5/11 D01F 6/04 CA (STN) REGISTRY (STN)

Claims (17)

(57) [Claims] 1. A mixed solvent comprising a solvent substantially consisting of bromochloromethane and / or 1,2-dichloroethylene and a cosolvent, wherein the cosolvent is carbon dioxide, sulfur hexafluoride, difluorochloromethane, , 1,1,2-tetrafluoroethane, 1-chloro-1,2,2,2-tetrafluoroethane, 1-chloro-1,1-difluoroethane,
Consists of 1,1-dichloro-2,2,3,3,3-pentafluoropropane, 1,3-dichloro-1,2,2,3,3-pentafluoropropane, dodecafluoropentane and tetradecafluorohexane Selected from one or more of the groups, wherein the proportion contained in the mixed solvent of the cosolvents is 3 to 6
A halogen-based solvent having a content of 5% by weight. 2. The method of claim 1, wherein the bromochloromethane and the 1,2-
2. The halogen-based solvent according to claim 1, wherein the solvent is a mixed solvent composed of a two-component solvent composed of dichloroethylene and a co-solvent, wherein the proportion of bromochloromethane in the two-component solvent is 40 to 75% by weight. 3. The composition according to claim 1, wherein the ratio of the co-solvent contained in the mixed solvent is 1
3. The composition according to claim 1, wherein the content is 0 to 30% by weight.
The halogenated solvent described in the above. 4. A propylene oxide as a stabilizer,
At least one of the group consisting of 1,2-butylene oxide, nitromethane, a phosphite represented by the structural formula (I), a diphosphite represented by the structural formula (2), and a diphosphite represented by the structural formula (3) 2. The composition according to claim 1, wherein said solvent is contained in an amount of 0.001 to 5 wt% of the mixed solvent.
4. The halogenated solvent according to any one of items 1 to 3. Embedded image Embedded image Embedded image 5. A polyolefin solution adjusted at a high temperature and a high pressure, wherein the halogen-based solvent according to any one of claims 1 to 4 is used as a solvent, and a polyolefin concentration in the polyolefin solution is 5 to 25% by weight. A polyolefin solution, characterized in that: 6. The polyethylene solution according to claim 5, wherein the polyolefin is polyethylene. 7. The polypropylene solution according to claim 5, wherein the polyolefin is polypropylene. 8. The polyolefin solution according to claim 5, wherein the trans form in 1,2-dichloroethylene is 30 to 40% by weight. 9. A method of producing a fibrillated polyolefin three-dimensional fiber by passing a polyolefin solution adjusted at a high temperature and a high pressure through a reduced pressure orifice, a reduced pressure chamber, and a spinneret, and releasing the solution to a normal temperature and normal pressure region. A mixed solvent consisting essentially of bromochloromethane and / or 1,2-dichloroethylene and a co-solvent, wherein the co-solvent is carbon dioxide, sulfur hexafluoride, difluorochloromethane,
1,1,2-tetrafluoroethane, 1-chloro-1,
2,2,2-tetrafluoroethane, 1-chloro-1,1
-Difluoroethane, 1,1-dichloro-2,2,3
3,3-pentafluoropropane, 1,3-dichloro-
One or more members selected from the group consisting of 1,2,2,3,3-pentafluoropropane, dodecafluoropentane, and tetradecafluorohexane, and the proportion contained in the mixed solvent of the co-solvent is 3 to 65 wt%. Wherein the polyolefin solution has a polyolefin concentration of 5 to 25% by weight. 10. A mixed solvent consisting essentially of a binary solvent consisting of bromochloromethane and 1,2-dichloroethylene and a co-solvent, wherein the proportion of bromochloromethane in the binary solvent is 40 to 75 wt. %. The method for producing a polyolefin three-dimensional fiber according to claim 9, wherein 11. The method for producing a three-dimensional polyolefin fiber according to claim 9, wherein a ratio of the co-solvent contained in the mixed solvent is 10 to 30 wt%. 12. Stabilizers include propylene oxide, 1,2-butylene oxide, nitromethane, phosphite represented by the structural formula (1), diphosphite represented by the structural formula (2), and phosphite represented by the structural formula (3). 10. The composition of claim 9, wherein one or more of the group consisting of the diphosphites represented is contained in an amount of 0.001 to 5% by weight of the mixed solvent.
12. The method for producing a polyolefin three-dimensional fiber according to any one of items 1 to 11. Embedded image Embedded image Embedded image 13. The method according to claim 9, wherein the trans form in 1,2-dichloroethylene is 30 to 40% by weight.
13. The method for producing a polyolefin three-dimensional fiber according to any one of items 1 to 12. 14. A mixed solvent comprising substantially 80 to 90% by weight of bromochloromethane and 20 to 10% by weight of carbon dioxide as a solvent, wherein the polyolefin concentration in the solution is 10 to 20% by weight. The method for producing a three-dimensional polyolefin fiber according to claim 9. 15. As a solvent, substantially 75 to 85% by weight of bromochloromethane and 25 to 15% by weight of 1,1,1,2.
The method for producing a three-dimensional polyolefin fiber according to claim 9, wherein a mixed solvent of tetrafluoroethane is used, and the polyolefin concentration in the solution is 10 to 20 wt%. 16. The method for producing a three-dimensional polyethylene fiber according to claim 9, wherein the polyolefin is polyethylene. 17. The method for producing a polypropylene three-dimensional fiber according to claim 9, wherein the polyolefin is polypropylene.