JPH05279273A - Halogenous solvent, solution using the same and production of three-dimensional fiber - Google Patents

Abstract

PURPOSE:To produce a solvent substitutable with trichlorofluoromethane or more excellent than trichlorofluoromethane, a solution using the solvent and three-dimensional yarn of polyolefin using the solvent. CONSTITUTION:A halogenous solvent is a mixed solvent substantially comprising bromochloromethane and/or 1,2-dichloroethylene and a cosolvent wherein the cosolvent is one or more selected from carbon dioxide, sulfur hexafluoride, difluorochloromethane, 1,1,1,2-tetrafluoroethane and the ratio of the co-solvent in the mixed solvent is 3-65wt.%. A solution of polyolefin in the solvent and three-dimensional yarn of polyolefin using the solvent are produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides an improved solvent having a low toxicity, a low flammability and a 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 fiber of a polyolefin excellent in strength and openability which is used for a nonwoven sheet by using the solvent and the solution.

In other words, it relates to an improved solvent which is non-toxic and non-flammable and which can be used very safely, the polyolefin solution using this solvent and the improved flash spinning process. Furthermore, the solvent according to the present invention can be applied not only to the polyolefin solution for flash spinning but also to detergents, foaming materials, gas for hollow fiber production, reaction solvents and the like.

[0003]

2. Description of the Related Art A method for producing a reticulated fiber of polyolefin is known as a flash spinning method. In this flash spinning method, polyolefin is added to an organic solvent, which can be said to be a liquefied gas, a polyolefin solution is prepared under high temperature and high pressure, and after that, the solution pressure is once reduced through a decompression orifice to cause phase separation, resulting in opacity. This is a method in which the solution is further jetted through a spinneret into an atmosphere under normal temperature and normal pressure to form a three-dimensional fiber, which is a well-known spinning method.

For example, this spinning method is described in USP3081.
519, USP3227794, USP3
No. 227784, USP3467744, U
SP3564088 publication, USP37545611 publication, EP285670A1 publication, EP321567A
No. 1, JP 357364A2, JP-B-40-
28125, JP-B-42-19520, JP-A-62-33816, and JP-A-63-50512.
It is described in the official gazette.

Fibers obtained by this flash spinning include short fibrous substances and continuous three-dimensional fibrous substances,
The former is used as a synthetic pulp and the latter is used as a nonwoven sheet. This non-woven sheet is generally called synthetic paper, and the main feature of this product is that it is highly water resistant, strong, light and fluff free. This non-woven sheet is highly praised by the world, and this non-woven sheet is used for airmail envelopes, floppy disk sleeves, oxygen absorber bags, desiccant bags, medical sterilization bags, building insulation and condensation prevention cloth, nuclear 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 breathable uniform sheet cannot be obtained without such fibers.

As a product of such a nonwoven sheet,
Tyvek (Tyvek registered trademark) manufactured by DuPont, USA
And Luxer (registered trademark) manufactured by the present applicant is already on the market. By the way, the solvent of the polymer used in the flash spinning method is required to have the following characteristics, which is already known in USP 3081519 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 under the temperature and pressure suitable for preparing the polymer solution, and 1% of the polymer at the boiling point of the solvent or lower. Being a solvent that dissolves only below, a solvent that can form a phase consisting of almost a polymer immediately after phase separation during spinning, and the separated polymer phase, a solvent that hardly remains,
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 their isomers, homologues and fats such as cyclohexane. Aromatic hydrocarbons, unsaturated hydrocarbons, halogenated hydrocarbons such as methylene chloride, carbon tetrachloride, chloroform, ethyl chloride and methyl chloride, alcohols such as ethanol, methanol and hexafluoroisopropanol, esters, ethers, ketones, Fluorinated 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 mentioned above are known.

The optimum solvent is selected from these solvents in consideration of various conditions of the spinning method used and the kind of the polymer used. However, as a solvent for the flash-spinning method for polyolefins, it has excellent polymer solubility and spinnability, and is also nonflammable and nontoxic trichlorofluoromethane, 1,1,2-trichloro-1,
2,2-trifluoroethane is preferred. In particular, trichlorofluoromethane is the most excellent solvent.

In flash spinning, a polymer solution under high temperature and high pressure is jetted into the atmosphere to be gasified, so that the solvent has a low boiling point and is not lipolytic even at high temperature and has lipophilicity sufficient to dissolve polyolefin. It is required to be a solvent and at least low toxicity and flame retardancy. That is, in flash spinning, the solvent is gasified and always separated from the polymer, and the gasified solvent is recovered and liquefied by an operation such as cooling and compression. Therefore, flash spinning is performed in a vast enclosed space. This is because otherwise the gasified solvent cannot be recovered. The size of the closed space is 2000 m ³ for example.
Filling such a huge space with flammable gas significantly increases the possibility of fire, explosion, etc.
It is extremely dangerous and virtually no flammable gases can be used as solvents.

Usually, a corona discharge device or a high-voltage static eliminator is built in this closed space and can serve as an ignition source for 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 non-woven fabrics, and inevitably there will be cases where workers are forced to enter and leave the enclosed space for repair and maintenance. The outlet of the formed non-woven sheet is a non-contact seal, and the gas in the closed space constantly leaks to the work place. Therefore, if it is toxic,
It cannot be used as a solvent for flash spinning. For this reason, the only solvent that can be used in the flash spinning method is trichlorofluoromethane, which is the only nonflammable and nontoxic solvent.

However, in recent years, it has been discovered that all halogenated hydrocarbons in which all hydrogen is replaced by chlorine and fluorine have extremely high ozone depletion ability as specific CFCs (also referred to as chlorofluorocarbons or CFCs),
From the standpoint of protecting the earth, production was banned by the year 2000. Naturally, the specific CFCs, trichlorofluoromethane, 1,1,2-trichloro-1,2,2-
Production of trifluoroethane etc. is also prohibited and will not be available. Therefore, trichlorofluoromethane cannot be used as a solvent for the flash spinning method of polyolefin.

Against this background, there has already been proposed a flash spinning method using a new solvent without using trichlorofluoromethane which is a specific flon. That is, USP 5032326, EP0357381
In A2 and JP-A-2-139408, methylene chloride and alternative fluorocarbons 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.
In addition, USP5081177, USP50230
25, EP0361684A1, JP2,
-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 difluoroloethane, 1,2-dichloro-1,1-difluoroethane, 1,1-dichloro-1-fluoroethane, etc., and EP 0407953 A2 further discloses 1,1-dichloro-
2,2,2-trifluoroethane, 1,2-dichloro-
A method of spinning using 1,2,2-trifluoroethane and the like, and further, EP 357364 A4 and JP-A-3-
Japanese Patent No. 76809 proposes a method of spinning using methylene chloride and carbon dioxide. Also, EP04
JP-A-14498A2 and JP-A-3-152209 propose a method using a mixed solvent system of water-containing organic solvents. Further, EP 431801 discloses 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 hydrocarbons 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 alternative CFCs proposed by 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 showing the degree of toxicity, ACGIH (American Conference of Govermental)
Industrial Hygienists) TLV ( T hreshold L im
its V alues of Airbone Contaminants) are known. TLV of trichlorofluoromethane is 1000ppm
In contrast, 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 clear that methylene chloride and its mixed solvent cannot be industrially used as a solvent for flash spinning. Furthermore, the use of methylene chloride is problematic in view of the properties required of the solvent during spinning. The reason is that the heat of vaporization 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 a solvent, flash-spun spun yarns are easily wetted by the residual solvent. As pointed out in Japanese Patent Application Laid-Open No. 3-76809, the moistened yarn has a commercial value because it tends to adhere to the periphery of the roller used for fixing the yarn to the sheet structure and to be wound. Non-woven sheet cannot be used and cannot be produced commercially. Therefore, when methylene chloride is used as a solvent, a low boiling point 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. Will be required. Increasing the polymer concentration is effective in increasing the coagulation heat generation amount of the polymer when flushing the polymer solution and utilizing the heat to accelerate the drying of the spun yarn. In this case, the lack of either the use of a low boiling point gas or the increase of the polymer concentration results in a wet yarn. 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 product tends to be deteriorated. Therefore, it is understood that methylene chloride cannot be used from the viewpoint of spinnability.

There is also a problem in the proposal using alternative CFCs such as US Pat. No. 5,081,177. 1,1-
Dichloro-2,2,2-trifluoroethane and its isomers have recently been found to cause tumors in rats, albeit benignly. Furthermore, these alternative CFCs
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 of using hydrocarbon, methylene chloride or the like as a cosolvent has been published at the same time. However, even if the alternative CFCs are made to coexist with hydrocarbons, methylene chloride, etc., the ratio of the alternative CFCs in the solvent is still high at 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 remains. As described above, 1,1-dichloro-2,2,2-trifluoroethane and its isomers have problems in toxicity and solubility in high-density polyethylene. Similarly, 1,1-
Dichloro-2,2-difluoroethane and its isomers also have problems in toxicity (toxicity to reproductive organs) and solubility of high-density polyethylene. On the other hand, 1,1-dichloro-1-fluoroethane and its isomers, even when used alone, dissolve high-density polyethylene and give high-quality yarn. However,
These solvents are very likely to be thermally decomposed, and even if they are rapidly dissolved by an extruder, they release a large amount of hydrogen chloride or hydrogen fluoride and thermally decompose to easily generate a halogenated oligomer.
These decomposed 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 flash spinning solvents because they are easily decomposed by heat and have high ozone depletion ability.

The technique proposed in EP357364A4 uses methylene chloride as a solvent,
Cannot be used for the reasons already mentioned. The method of flash spinning using carbon dioxide and water as a solvent, which is proposed in EP 431801, can be applied to a specific polyolefin having vinyl alcohol having a high hydrophilicity as a copolymerization component. However, this solvent is common polyethylene,
Due to their poor ability to dissolve polypropylene, it is almost impossible to obtain fibers with desirable 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.

Furthermore, proposals using a mixed system of water-containing organic solvents such as EP 041498A2 cannot be used because the solvent used has high flammability. In addition, 1,1-dichloro-disclosed in JP-A-4-185708
In the method of spinning using a mixture of 2,2,3,3,3-pentafluoropropane and / or 1,3-dichloro-1,2,2,3,3-pentafluoropropane and hydrocarbons, The hydrocarbons used in the mixture have problems such as flammability and high toxicity, and therefore cannot be put to practical use.

From the above, the trichlorofluoromethane alternative solvent for flash spinning that has been proposed so far is
It is clear that all of them have unsolved problems, and no sufficiently satisfactory solvent that can replace trichlorofluoromethane has been proposed yet. The purpose of the present invention is to
It is an object to provide a solvent that can substitute for or better than trichlorofluoromethane. That is, it is intended to provide a solvent which is excellent as a solvent for flash spinning of polyolefin, which is hard to burn, has low toxicity, and has a low ozone depletion ability. It is also another object of the present invention to provide a polymer solution using this solvent. Furthermore,
Another object of the present invention is to provide an improved method for flash spinning a polyolefin, which can obtain a three-dimensional fiber having high strength and excellent openability by using this solvent. Of course, the solvent and the solution according to the present invention can be used in other technical fields where the characteristics can be utilized, for example, as a reaction solvent used as a CFC substitute, a foaming agent, a cleaning agent, and the like.

[0019]

In order to achieve the above-mentioned object, the present inventors have conducted a great deal of research on solvent screening, and have found out how to compare fibers with polyolefin three-dimensional fibers by conventional flash spinning methods. It was possible to reach the present invention as a result of trial and error as to whether or not a fiber having excellent performance could be obtained.

That is, the first invention of the present invention is a mixed solvent consisting of a solvent consisting essentially of bromochloromethane and / or 1,2-dichloroethylene and a cosolvent, wherein the cosolvent comprises carbon dioxide, hexafluoride. Sulfur oxide, 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-
It is selected from one or more of the group consisting of dichloro-1,2,2,3,3-pentafluoropropane, dodecafluoropentane, and tetradecafluorohexane, and the proportion of the cosolvent contained in the mixed solvent is 3 to. It is a halogen-based solvent characterized by being 65 wt%.

In a mixed solvent composed of a two-component solvent consisting essentially of bromochloromethane and 1,2-dichloroethylene and a co-solvent, the proportion of bromochloromethane in the two-component solvent is preferably 40 to 75 wt%. ..
The preferred ratio of the cosolvent contained in the mixed solvent is 10 to 3
It is 0 wt%. As a stabilizer, propylene oxide,
1,2-butylene oxide, nitromethane, a phosphite represented by the structural formula (I), a diphosphite represented by the structural formula (2), or a diphosphite represented by the structural formula (3), or one of them. It is advisable to add the above to 0.001 to 5 wt% of the mixed solvent.

[0022]

[Chemical 7]

[0023]

[Chemical 8]

[0024]

[Chemical 9]

A second invention of the present invention is a polyolefin solution prepared at high temperature and high pressure, which comprises a mixed solvent consisting of a solvent consisting essentially of bromochloromethane and / or 1,2-dichloroethylene and a cosolvent. Used as a cosolvent, 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, tetradecafluorohexane. A polyolefin solution characterized in that the content of the co-solvent in the mixed solvent is 3 to 65 wt% and the concentration of the polyolefin in the polyolefin solution is 5 to 25 wt%. is there.

Polyethylene or polypropylene can be used as the polyolefin. Also 1,2-
The trans form in dichloroethylene can be used in an amount of 30 to 40 wt%. A third invention of the present invention is to prepare a polyolefin solution prepared at high temperature and high pressure, a decompression orifice,
Pass through the decompression chamber and spinneret and release into the room temperature and pressure range.
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 the solvent, and the cosolvent is carbon dioxide, hexafluoride. Sulfurized, 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-dichloro-1,2,
Selected from the group consisting of 2,3,3-pentafluoropropane, dodecafluoropentane, and tetradecafluorohexane, or more, and the proportion of the cosolvent contained in the mixed solvent is 3 to 65 wt%. The method for producing a three-dimensional polyolefin fiber is characterized in that the concentration of the polyolefin in the polyolefin solution is 5 to 25 wt%.

At this time, a mixed solvent composed of a two-component solvent consisting essentially of bromochloromethane and 1,2-dichloroethylene and a co-solvent is used as a solvent, and the proportion of bromochloromethane in the two-component solvent is 40 to 75 wt. It is good to use%. By this method, the present inventors can obtain a three-dimensional fiber of a polyolefin having a markedly high strength and good openability, which is different from the conventionally known methods, even though it is a solvent having a small ozone depletion ability. did it.

As described above, the solvent used for flash spinning is premised on being an organic solvent which becomes a gas at normal temperature and pressure. That is, the polyolefin is melted at 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 out 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 this gas jet, and becomes a three-dimensional fiber having high strength.

Therefore, the properties to be possessed as the flash spinning solvent are widely known as described above, but the details are as follows. At normal temperature and pressure, the polymer does not dissolve at all, but at temperatures above the melting point of the polymer and at high pressures far above atmospheric pressure, the polymer is dissolved. Phase change from a transparent liquid to an opaque liquid at a temperature exceeding the melting point of the polymer and not causing thermal deterioration.
In particular, in the case of flash spinning, LC mentioned in polymer solution theory
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 moreover, the phase change should occur instantaneously. This property is important because flash spinning causes a phase change from transparent to opaque under pressure. The moment you leave the spinneret, you must gasify it.
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 almost isentropic change. Therefore, the spinneret outlet spontaneously becomes a liquid / gas mixture. As it is, it cannot be used because it becomes a leaked three-dimensional fiber. However, since the polymer has heat,
This amount of heat gasifies the liquid to form dry three-dimensional fibers. This means that the heat of vaporization of the organic solvent must be appropriate. The organic solvent must have good thermal stability as it is exposed to temperatures above the melting point of the polymer. In addition, in the present invention, thermal stability means that it is difficult to carry out heat division at a temperature at which a polymer is dissolved. It must be non-combustible or flame-retardant because there is electrical equipment that fills a large-capacity enclosed space and is an ignition source in the enclosed space. The gas that fills the enclosed space is often touched by humans and must be non-toxic. Since the entire flash spinning device becomes a high-pressure device, it must be a solvent with low corrosiveness. ODP must be small. Preferably,
It is preferably less than 0.01.

Of particular importance are low boiling point, LCST type polymer solutions, thermal stability, low flammability, non-toxic, low ODP. The inventors have found that low boiling point, LCST type polymer solutions,
An extremely large number of experiments were conducted in order to find a flash spinning solvent satisfying the six conditions of thermal stability, low flammability, nontoxicity, 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, 3, 3
We have found that a mixed solvent consisting essentially of one or more cosolvents of the group consisting of pentafluoropropane, dodecafluoropentane, tetradecafluorohexane, fulfills the above six conditions completely or almost completely. It was

Hereinafter, the reason why the solvent and solution of the present invention satisfy the above-mentioned 6 conditions particularly required for flash spinning will be described, and the characteristics of the solvent, the preferable composition range thereof and the like will be described. In order to avoid complexity, difluorochloromethane is HCFC-22,1,1,1,2-tetrafluoroethane and 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, 1,3-dichloro-1,2,2,3,3-pentafluoropropane is HC
FC-225cb, dodecafluoropentane is FC-61
12, tetradecafluorohexane is abbreviated as FC-7114 in the following description. Toxicity Bromochloromethane, AC of 1,2-dichloroethylene
The TLVs of GIH are all 200 ppm and show high values (that is, low toxicity) as chloro compounds. The cosolvent TLV is, for example, 50% with carbon dioxide.
It is known to be extremely low in toxicity, since it is 00 ppm and sulfur hexafluoride is up to 1000 ppm. Regarding other cosolvents, TLV is not specified, but its toxicity is considered to be very small. Moreover, no carcinogenicity to humans has been reported with any of these solvents. Therefore, the flash spinning solvent of the present invention composed of these solvents is not completely non-toxic, but has a considerably low toxicity. Keeping a controlled concentration in the work place and keeping it in contact with people, using protective equipment such as an air line mask, etc. will not harm the health of human beings while paying attention to gas leakage and ventilation in the place. Combustibility and Thermal Stability Bromchloromethane and 1,2-dichloroethylene may undergo thermal decomposition when exposed to high temperatures, so it is necessary to use stabilizers and the like as necessary. Many stabilizers have been developed today, but the high temperature and high pressure required for flash spinning (typical temperature and pressure is 200 ° C, 200 kg / cm
^There are very few stabilizers that are effective under ² ).
This is because the solvent is used under extremely severe conditions, and the stabilizer used here is a solvent stabilizer, so if used in too large an amount, after spinning, the stabilizer is concentrated in the yarn and blooms from the yarn, or Because you will bleed.
Therefore, a small amount of a highly effective stabilizer at high temperature and high pressure is required. As a result of investigating a large number of stabilizers, it was found that epoxy compounds, nitro compounds, diphosphites and phosphites are effective. In particular, diphosphite showed a high heat stabilizing effect. Furthermore, as a result of detailed examination of the structure of the stabilizer, as the stabilizer, propylene oxide,
It was found that 1,2-butylene oxide, nitromethane, the phosphite represented by the structural formula (1), the diphosphite represented by the structural formula (2), and the diphosphite represented by the structural formula (3) are particularly excellent. It was

[0033]

[Chemical 10]

[0034]

[Chemical 11]

[0035]

[Chemical 12]

In the present invention, R¹, R², R³Is charcoal
Monovalent hydrocarbons of different or similar prime numbers from 1 to 30
It is a basic group, for example, n-C_nH_{n + 1}, Iso
-C _nH_{n + 1}(However, n is an integer from 1 to 30.
It ), Phenyl group or partially alkyl group
And a benzene ring. Of these combinations
Of which, R¹, R², R³One or two of them are aromatic groups
It is preferable to have the following in order to improve thermal stability. Well
In addition, the remaining one or two are aliphatic charcoal in which n is 8 or more.
Hydrogen fluoride is preferable from the viewpoint of improving thermal stability.
R^Four, R^FiveIs a monovalent aliphatic having 8 to 30 carbon atoms
A hydrocarbon, examples of which are n-C _nH_{n + 1}, I
so-C_nH_{n + 1}(However, n is an integer from 8 to 30.
Is. ). Preferred n is for enhancing thermal stability.
And 12 to 24, and more preferably 16 to 20
It

These stabilizers may be used alone or in combination with other stabilizers and additives.
Other stabilizers and additives include dibutyl tin malate,
Examples thereof include metal soaps, 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, the diphosphite represented by the structural formula (2) is most effective in reducing the decomposition reaction of the solvent. However, since diphosphite has a low solubility in the solvent of the present invention, other stabilizers may be used depending on the process. Regarding the amount to be used, generally, one or more of the stabilizers of the present invention can be used in an amount of about 0.001 to 5 wt% of the mixed solvent of the present invention, and in the case of an epoxy compound and diphosphite, When it is 0.001 to 0.1 wt%, a high heat stability effect can be exhibited. In order to enhance the effect of the stabilizer, it is preferable that the bromchloromethane, 1,2-dichloroethylene and the cosolvent used in the present invention are substantially pure products. In particular, free acids such as hydrogen chloride, hydrogen bromide and water are preferably as small as possible, particularly preferably 10 ppm or less.

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

Bromochloromethane is a completely nonflammable solvent, known as a powerful extinguisher called CB.
It is a solvent with extremely high combustion suppression effect. Therefore, the mixed solvent of bromochloromethane and the co-solvent except HCFC-142b is completely incombustible with any 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 by mixing with a nonflammable solvent, it is extremely easy to completely inflame or
It can be a flame-retardant solvent. As such a nonflammable solvent, the cosolvent of the present invention is extremely suitable. In order to reduce or eliminate flammability, the solvent composition of the present invention is very useful, and the preferable ratio of such 1,2-dichloroethylene is 70 to 90 wt%, particularly preferably 70 ~ 80 wt%.

By combining 1,2-dichloroethylene and bromochloromethane, it is possible to prepare a solvent which is completely incombustible and at the same time has excellent thermal stability. By adding a non-combustible substance to the flammable solvent, the explosion range can be reduced. Therefore, in order to improve the flammability of 1,2-dichloroethylene, bromochloromethane was used as an incombustible substance. Bromochloromethane has a low toxicity and is an excellent good solvent for polyolefin under high temperature and high pressure as described later. Moreover, since 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.
Is the only one. For example, chloroform, carbon tetrachloride, chloroform, methylene bromide, bromoform, etc. also have a high combustion suppressing effect. However, since these compounds all have high toxicity, flash spinning cannot be used.

When the flammability of a mixed solvent of a binary solvent of 1,2-dichloroethylene and bromochloromethane and a co-solvent was examined, the proportion of bromochloromethane in the binary solvent was about 40% by weight and it was completely incombustible. I understood. Therefore, in order to prepare a completely incombustible two-component solvent, the proportion of bromochloromethane in the two-component solvent must be 40 wt% or more.

Now, 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 originates not only in the dilution effect by reducing the abundance ratio of bromochloromethane in the solvent but also in the effect of 1,2-dichloroethylene suppressing the thermal decomposition of bromochloromethane. 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 wt% or less. It is preferably 60 wt% or less, more preferably 50 wt% or less.

Therefore, in order to obtain a solvent which is completely incombustible and at the same time excellent in thermal stability, the proportion of bromochloromethane in the binary solvent of 1,2-dichloroethylene and bromochloromethane is 40 to 75 wt%, Preferably 4
The amount is 0 to 60 wt%, more preferably 50 to 60 wt%.
The mixing ratio of the cosolvent in the mixed solvent of the present invention composed of a binary solvent of 1,2-dichloroethylene and bromochloromethane and a cosolvent is generally 3 to 50% by weight.
Is. Particularly preferably, it is 5 to 30 wt%, and even more preferably 10 to 30 wt%.

Although bromochloromethane has a low thermal stability, it can be practically used by adjusting the solution using an extruder at a high temperature and high pressure and a short residence time, 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 pressure. Therefore, one of the important meanings of mixing these gaseous co-solvents 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 not higher than 60 ° C., more preferably not higher than 50 ° C., as long as it is gasified at room 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 gaseous cosolvent. The boiling point of bromochloromethane is 68 ° C. In addition, 1,2-dichloroethylene has two geometric isomers, a trans isomer and a cis isomer.
The boiling point of trans-1,2-dichloroethylene is 47.
At 7 ° C, the boiling point of cis-1,2-dichloroethylene is 6
It is 0.25 ° C. Therefore, by changing the mixing ratio of the gaseous cosolvent, 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
℃), HCFC-225cb (boiling point: 56.1 ℃), F
Regarding the co-solvents of C-6112 (boiling point: 30 ° C.) and FC-7114 (boiling point: 56 ° C.), the boiling points are slightly higher, but even if these liquid co-solvents are used, the boiling points are substantially 60 ° C. or less. A solvent can be obtained. The spun yarn was never wet even 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 polyolefin is dissolved therein. As described above, the basic principle of flash spinning is to spin a polymer solution at high temperature and high pressure under reduced pressure to cause phase separation to form an opaque liquid composed of at least two phases of a polymer and a solvent, and then perform 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.

By the way, this cloud point curve was measured by the apparatus shown in FIGS. 1 and 2 in the present invention. FIG. 1 is an explanatory diagram of the entire apparatus, and FIG. 2 is an explanatory diagram of an optical cell container for measuring a cloud point. That is, the optical cell container (internal size, diameter 40 mm × length 83 mm, volume about 100 cm ³ ) 1 is provided with two optical windows 2 so that the inside can be observed through light. The length of the optical path through which the light passes is 18 mm because the thickness of the glass 14 of the optical window 2 is 9 mm, and the length of the glass 14 is 58 mm in total because the thickness of the solution is 40 mm. The optical cell container 1 has a stirring blade 13 built therein, and the inside of the container is stirred 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 that hits the optical window is "co" so as not to interfere with optical observation.
It is processed in the shape of. Further, the 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. In order to adjust the liquid pressure in the optical cell container, a plunger type pressure regulator is installed via a pipe 9. Further, a pipe 10 is provided for degassing the gas in the optical cell container and pushing out the liquid in the container. Further, the entire optical cell container is covered with a cast aluminum 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 and supplied to the container so that the polymer concentration became a predetermined concentration and the inside of the container became a liquid seal. The polymer solution was prepared based on the volume% for the sake of simplifying the experiment. When a gaseous co-solvent is used as the mixed solvent, the mixed solvent was adjusted in advance in a stainless steel cylinder of 300 cm ^{3 at} a predetermined ratio and introduced into the optical cell container by pressurizing with nitrogen gas. When a liquid cosolvent was used, it was introduced into the optical cell container as it was after adjustment. In each case, a predetermined amount of 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 heating then causes the pressure in the container to rise as the liquid expands. The heating rate was 4.5 ° C / min. Liquid state is 50kg / cm ² , 1
After the temperature was close to 05 ° C, the pressure was not adjusted until the polymer was completely dissolved. In this way, the polymer reaching the vicinity of the melting point of the polymer starts to dissolve in the solvent. A polymer solution was prepared in this state.

Then, the cloud point is measured. While increasing the temperature, the pressure was changed by the plunger type pressure regulator, and the point at which the solution began to cloud, that is, the cloud point was visually searched for. 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 raised to a considerably high temperature. For example, in the case of using high-density polyethylene having a weight average molecular weight of 102000, 220 ° C at an extremely thin concentration of 2v%.
Is 62kg / cm ² and 230kg is 83kg / cm ² at the line where the cloud point curve is finally observed. (The cloud point pressure decreases with the polymer concentration. The curve cannot be observed). This result is
1,2-dichloroethylene shows that it is a good solvent for polyolefin under high temperature and high pressure. Further, bromochloromethane has a higher solubility than 1,2-dichloroethylene, that is, it is an extremely good solvent for polyolefin under high temperature and high pressure. For example, when the above-mentioned high-density polyethylene is used, 2v%
It is not possible to ascertain the cloud point, even at extremely low concentrations.

On the other hand, the cosolvent cannot dissolve the polymer in the temperature range of flash spinning. It is a complete poor solvent. Therefore, by combining the two chloro compounds, which are good solvents for polyolefin, and the cosolvent under high temperature and high pressure, it was possible to bring the cloud point curve to a position suitable for flash spinning. Such a preferable cloud point pressure is about 80 to 300 kg / cm ^{2 at} 200 ° C., and 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 wt% for any chloro compound. Particularly preferably, it is 5 to 30 wt%, and even more preferably 1
It was 0 to 30 wt%. Exemplifying a particularly preferable amount of cosolvent for each cosolvent, carbon dioxide is 10 to 20 wt%,
Sulfur hexafluoride is 5 ~ 20wt%, HCFC-22 is 15 ~
30 wt%, HFC-134a 15-25 wt%, HCF
C-142b is 20-40wt%, HCFC-124 is 1
5 ~ 30wt%, HCFC-225ca 30 ~ 65wt
%, HCFC-225cb is 30-65 wt%, FC-6
112 is 15-30 wt%, FC-7114 is 15-30%
wt%. The preferable amounts of these co-solvents are slightly different depending on the type of polymer and the degree of polymerization, but are generally in the range shown here. Of course, two or more kinds of these cosolvents may be mixed and used, or a new solvent may be partially added separately. Regarding 1,2-dichloroethylene, the cloud point of the cis isomer was slightly low, but the difference between the trans isomer and the cis isomer was not a substantial problem.

3 and 4 show examples of cloud point curves. That is, FIG. 3 shows that A) bromochloromethane / carbon dioxide (85/15 wt%) and B) bromochloromethane / HFC-134a (80/20 wt%) and (75/2).
5 wt%) is a cloud point curve of a solvent composition. The upper region of each cloud point curve is one-phase and the lower region is two-phase. The polymer is 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 is one-phase and the lower region is two-phase. The polymer is 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 co-solvents, and spinning results were used to find suitable solvents and their compositions.

Bromochloromethane or / and 1,2
-Dichloroethylene with sulfur hexafluoride, FC-6112,
Even if FC-7114 is mixed at room temperature under autogenous pressure, a uniform solution cannot be obtained. However, it is possible to obtain a homogeneous solution by increasing the temperature or / and the pressure. Therefore, it is necessary to control the temperature and pressure when preparing a uniform solution. Generally, a uniform solution can be obtained for bromochloromethane at a temperature of 140 ° C. or higher and for 1,2-dichloroethylene at a temperature of 80 ° C. or higher. ODP OH determines the lifetime of halogen compounds in the atmosphere.
It is an active chemical species called a radical. It is produced by the reaction of oxygen and organic matter under the 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 life of 1,2-dichloroethylene in the atmosphere is short. ODP is required in consideration of the life in the atmosphere, and therefore specific CFCs or carbon tetrachloride> alternative CFCs> methylene chloride (ODP is 0.003)> a 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-CFC structure, the ODP is naturally 0. Therefore,
The solvent of the present invention using these co-solvents can be used without any problems in the future, because it is substantially composed of a solvent having no ozone depletion ability. To date, there have been disclosed flash spinning solvents with some low ODP alternative CFCs, but these solvents all have ozone depletion potential, albeit at low levels. Nowadays, the regulations concerning chlorofluorocarbons are increasing more and more, and it is clear how important and excellent the present invention is to provide a solvent which has no ozone depletion ability and which is nonflammable and has low toxicity. On the other hand, HCFC-22, HCF
C-142b, HCFC-124, HCFC-225c
Since a, HCFC-225cb hydrochlorofluorocarbon has an ODP of 0.01 order, there is a possibility that it cannot be used within 20 years due to stricter regulations.

From the above-mentioned restrictions, consideration and experimental results, the preferable mixing ratio of the cosolvent is 5 to 30 wt%.
Is. Particularly preferably, it is 10 to 30 wt%. In addition, since ODP is substantially 0 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 cosolvents that are uniform and have high operability, are particularly preferable.

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

The three-dimensional fiber spun using the flash spinning solvent of the present invention determined as described above has excellent openability and high strength without getting wet, and can be a good nonwoven sheet. It was a thing. The weight ratio of 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, it is possible to easily produce a three-dimensional fiber of a polyolefin which has excellent openability and high strength. 5
If it is less than wt%, it becomes a pulp-like or low-strength yarn.
If it is 5 wt% or more, the yarn openability is low, which is not preferable in any case. More preferably 10 to 20 wt%
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, the copolymerization component is preferably 15% by weight or less and maintains the above-mentioned density. The polypropylene preferably contains about 85 wt% or more isotactic polypropylene, and about 15 wt% or less of other polypropylene or
A copolymerization component such as ethylene or butene may be contained. Further commonly known polymer additives, light stabilizers,
The polymer may contain a lubricant, a nucleating agent, a cross-linking agent, a plasticizer, a filler and the like.

The apparatus used in the present invention may be equipped with a dissolution adjusting apparatus and a spinning apparatus including a decompression orifice, a decompression chamber and a spinneret. Before that, there are a device for opening / dispersing the three-dimensional fibers, a moving conveyor device for forming the opened / dispersed three-dimensional fibers into a sheet, and a winder for winding the resulting sheet. The sheet forming unit is housed in a closed box, and the solvent gas in the box is collected. 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 the purpose of specifically illustrating the invention and is not intended to limit the scope of the claims of the invention.

Example 1 Melt index is 0.7
82.1g of high-density polyethylene 8 and 613g of mixed solvent of bromochloromethane / carbon dioxide (85 / 15wt%)
Was charged into an autoclave, and the (polymer concentration 11.8
wt%) The autoclave was heated while rotating the propeller stirrer to dissolve the high density polyethylene. The solution was further heated and the solution pressure was increased to completely dissolve the polymer. After dissolution, the solution was discharged from the discharge nozzle at the bottom of the autoclave and the pressure was kept at about 250 kg / cm ² so that the solution pressure did not exceed 300 kg / cm ² . When the temperature of the solution reached 200 ° C., the nitrogen gas introduction valve in the upper part of the autoclave was opened, nitrogen pressure of 258 kg / cm ² was applied, and the discharge valve in the lower part 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 the spinneret (introduction angle from the decompression chamber to the nozzle was 60 mm).
°, the nozzle diameter is 0.5 mm, the length is 0.5 mm, and a circular groove with a diameter of 3.3 mm and a depth of 3 mm is formed outside the nozzle. ) And released into the atmosphere. The spread yarn was made by hitting a vinyl chloride plate inclined at about 45 ° at a position about 20 to 40 mm away from the spinneret. The opened fiber in the opened state was received by a wire mesh of 10 mesh and collected. The pressure in the decompression chamber is 174 kg
It was / cm ² . The spinning speed was 279 m / s.

The obtained fiber is an unopened yarn and has a fineness of 97d.
Tensile strength 6.0 g / d, tensile elongation 37%, specific surface area 24 m ² / g, fineness 95 d with open yarn, tensile strength 5.8 g / d, tensile elongation 34%, a well-formed three-dimensional fiber. It was

Comparative Example 1 Example 1 was repeated using trichlorofluoromethane as a solvent and 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 with a fineness of 99d and a tensile strength of 5.4 g /
d, the tensile elongation was 27%, and the specific surface area was 21.2 m ² / g.

That is, the spinning speed of Example 1 was 279 m /
The spinning speed of Comparative Example 1 is only 159 m / s as compared with s. This shows that the use of the solvent according to the present invention enabled spinning at a significantly higher speed than in the conventional production method. The ability to increase the spinning speed is
Further, it means that a highly drawn yarn can be obtained as compared with the conventional one. This is evidenced by the tensile strength and tensile elongation values of the fiber of Comparative Example 1 being 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 spun yarn was investigated. Table 1
Shows the spinning results. The measurement of the number of free fibrils was performed as follows. That is, the sampled open yarn is gently sandwiched between glass plates, and while moving the optical microscope with an objective lens of 1.6 times and an eyepiece lens of 10 times in the fiber width direction, Count the number and convert it per 100 denier to give the number of free fibrils.

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

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

[0069]

[Table 1]

[Example 6] By changing only the solvent composition,
With the polymer and polymer concentration of Example 1 fixed,
Reticulated fibers were produced using the spinning device of Example 1. Bromochloromethane / carbon dioxide ratio of 90.6 / 9.4
At wt%, the strength is 4.8 g / d and the specific surface area is 36 m ² / g,
At 80/20, at 5.2 g / d and 70/30 wt%,
5.0 g / d of reticulated fiber was obtained. All of these reticulated fibers showed good openability.

[Example 7] By changing only the polymer concentration and keeping the polymer and solvent composition of Example 1 fixed,
Reticulated fibers were made using the spinning position of Example 1. When the polymer concentration is 7.0 wt%, the strength is 3.4 g / d, 20.
At 5 wt%, 5.4 g / d of reticulated fiber was obtained. All of these reticulated fibers showed good openability.

Example 8 Melt index is 0.7
81.2 g of high-density polyethylene 8 and a mixed solvent 6 of bromochloromethane / HFC-134a (78/22 wt%)
57 g was charged into the autoclave, and (polymer concentration 1
The autoclave was heated while rotating the propeller-type stirrer to dissolve the high-density polyethylene. The solution was further heated and the solution pressure was increased to completely dissolve the polymer. After dissolution, the solution was discharged from the discharge nozzle at the bottom of 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, 270 kg / cm ² nitrogen pressure was applied, 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 the spinneret (introduction angle from the decompression chamber to the nozzle 60 °, nozzle diameter 0. 5 mm, a length of 0.5 mm, and having a circular groove of 4.0 mmφ and a depth of 3 mm on the outside centering on the nozzle) was discharged into the atmosphere. Approximately 20 ~ open fiber from the spinneret
It was made by applying it to a vinyl chloride plate inclined at about 45 ° at a position 40 mm apart. The opened fiber in the opened state was received by a wire mesh of 10 mesh and collected. The pressure in the vacuum chamber was 159 kg / cm ² . The spinning speed was 206 m / s.

The obtained fiber is an unopened yarn and has a fineness of 126.
d, tensile strength 6.6 g / d, tensile elongation 36%,
Specific surface area 15 m ² / g, fineness 123d with open yarn, tensile strength 6.5 g / d, tensile elongation 20%, fiber width 3.5
It was a well-formed reticulated fiber at -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 physical properties of spun yarn was examined.
Table 2 shows the spinning results. However, the spinneret has an inlet angle of 60 ° from the decompression chamber, a nozzle diameter of 0.5 mm, a length of 0.5 mm, and a circular groove of 3.3 mmφ and 3 mm depth outside the nozzle. Changed to.

The obtained fiber was a good quality three-dimensional reticulated fiber having excellent openability 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 polymer concentration of Example 8. The ratio of bromochloromethane / HFC-134a is 90 /
The strength was 4.2 g / d at 10 wt%, 5.8 g / d at 85/15 wt%, and 5.2 g / d at 70/30 wt%.
The following reticulated fiber was obtained. All of these reticulated fibers showed good openability.

Example 13 A reticulated fiber was produced using the spinning apparatus of Example 8 while changing only the polymer concentration and fixing the polymer and solvent composition of Example 8. When the polymer concentration is 7.2 wt%, the strength is 3.4 g / d, 2
At 0.5 wt%, 5.8 g / d reticulated fiber was obtained.
All of these reticulated fibers showed good openability.

[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 transformers-1, 2
-Dichloroethylene, BCM refers to bromochloromethane. HCFC-225 is HCFC-225ca and H
A 50/50 wt% mixture of CFC-225cb is shown.

Example 30 A melt index of 0.
78 high density polyethylene 81.7 g, 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 the autoclave, and the polymer concentration was 11.8 wt.
%) The autoclave was heated while rotating the propeller stirrer to dissolve the high density polyethylene. The solution was further heated and the solution pressure was increased to completely dissolve the polymer. 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 in the upper part of the autoclave was opened, a pressure of 250 kg / cm ² was applied, and the discharge valve in the lower part of the autoclave was quickly opened. The solution is then reduced to a vacuum orifice (diameter 0.65
mm: Length of 5 mm) and pressure reduction chamber (diameter 8 mm, length 40)
mm) and spinneret (introduction angle from the decompression chamber to the nozzle 6 °, nozzle diameter 0.5 mm, length 0.5 mm, 3.3 mmφ outside the center of the nozzle, 3 mm deep circular groove) Have) and released into the atmosphere. The spread yarn was made by hitting a vinyl chloride plate inclined at about 45 ° at a position about 20 to 40 mm away from the spinneret. The opened fiber in the opened state was received by a wire mesh of 10 mesh and collected.

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

A flammability test using a mixed gas with air was also conducted. The solvent shown in Example 30 was nonflammable in any mix composition with air. However, for comparison, 1,2-dichloroethylene / carbon dioxide (85/1
When the same combustion test was performed with a composition of 5 wt%), 1
When ignition energy of 000 mJ or more was applied, it burned depending on the mixed composition of air.

[Example 31] The spinning temperature was raised to 215 ° C.
And Example 1 was repeated. The obtained thread wears slightly black
It was colored. Similarly, propylene oxide was added to the spinning solvent.
De, 1,2-butylene oxide, nitromethane, tri
Phenyl phosphite, dinonyl phenyl phosphite
G, trilauryl phosphite, R^FourIs n-C₁₈H₃₇so
Diphosphite represented by a certain structural formula (2) (manufactured by Asahi Denka Co., Ltd.
PEP-8F), or R^FiveIs n-C₁₂H _{twenty five}~ NC₁₅
H₃₁A structural formula that is randomly bound to the range
Diphosphite represented by (3) (MARK-made by Asahi Denka Co., Ltd.
(1500) is mixed with a solvent in an amount of 0.1 wt% and then spun.
did. The yarns obtained with these stabilizers are completely colored.
I didn't. In particular, PEP-8F and MARK-15
For 00, it was completely colored even if 0.025 wt% was used.
I didn't.

Other stabilizers were investigated for comparison. The colorability was examined at a concentration of 0.1 wt% with respect to the solvent. Zinc stearate, barium stearate, methanol, dibutyltin dilaurylate, tributylamine, methyl acetate, catechol, etc. were examined, but coloration was hardly improved.

[Examples 32-34] Spinning was performed using isotactic polypropylene instead of high-density polyethylene. In Example 32, polypropylene having 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. 21 spinning
Performed at 5 ° C. and used as a stabilizer, PEP-8F of Example 31.
Was added to the solvent in an amount of 0.5 wt%. 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 moist 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 wt% based on the dry yarn. On the other hand, in each of the examples of the present invention, dried yarn was obtained.

When the polymer concentration was increased to 18 wt%, the yarn dried, but the openability was evaluated by the evaluation method of Table 1 as Δ to ×.
Met. For example, using the conditions of Example 1, the number of free fibrils was 130. By the way, Example 1
The free fibril count of was 310. Example 14,
The same experiment was repeated by collecting 15 solvents. 1,2
-The proportion of the trans form of dichloroethylene gradually decreases as the number of times of spinning is increased, and the proportion of the trans form becomes 30 to 4
The value became almost constant in the range of 0 wt%. Further, Examples 14 and 15 were repeated using 1,2-dichloroethylene having a trans isomer / cis isomer ratio of 35/65 wt%, but the trans isomer / cis isomer 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 an increased blood affinity is shown as an example in which the present invention is applied 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
It dissolved in 0 cm ³ . A bundle (about 7,000 pieces) of regenerated cellulose hollow fiber membranes (inner diameter 0.2 mm, film thickness 0.01 mm, length 30 cm) was shaken for 30 minutes in this treatment liquid while occasionally moving up and down. The treated regenerated cellulose hollow fiber membrane bundle was immersed in methanol for one day and then dried under reduced pressure at room temperature to obtain a hollow fiber membrane bundle (1) in which the hollow fiber surface was esterified.

For comparison, 1,1,2-trichloro-containing a specific CFC currently in industrial use is used.
1,2,2-trifluoroethane / acetone (87.5 /
12.5 wt%) bromochloromethane / HFC-134
It was used instead of a (85/15 wt%). The thus obtained esterified hollow fiber membrane bundle is designated as (2). Obtained esterified regenerated cellulose hollow fiber membranes (1) and (2) and untreated regenerated cellulose hollow fiber membranes (3)
Each was incorporated into a dialysis machine, and extracorporeal circulation was performed by dogs.
The dog is a beagle dog weighing about 10 kg, 100 cm ³ / mi
Blood of n was taken from the shunt that was added to the neck and allowed to flow into the dialyzer. Before the extracorporeal circulation, the dialyzer was washed with physiological saline and then the dialyzer and the blood circuit were filled with physiological saline containing 5 U / cm ³ of heparin, and then blood was flown. Blood was collected at the inlet of the dialyzer and the white blood cell count was measured.
Table 6 shows the values at 15 minutes and 30 minutes after dialysis, where the white blood cell count immediately before dialysis is 100.

[0094]

[Table 6]

When the solvent of the present invention is used, a regenerated cellulose hollow fiber membrane having a blood affinity equal to or higher than that of the 1,1,2-trichloro-1,2,2-trifluoroethane / acetone solvent is obtained. I understand that you give.

[0096]

INDUSTRIAL APPLICABILITY The solvent and solution according to the present invention have a low ozone depletion ability and can be used as a novel CFC alternative solvent and solution. In particular, the solvent and solution of the present invention are extremely useful as a solvent for flash spinning, a detergent, a foaming material, 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 strength and opening property equivalent to or higher than that of the case of using trichlorofluoromethane without depleting the ozone layer. can get. If the present invention is utilized, the three-dimensional fiber of polyolefin, which is much more excellent in openability than the conventional flash spinning method using a solvent capable of substituting trichlorofluoromethane and has high strength, is always stable. Maintains productivity and is easy to manufacture. This industrial significance is of great value.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a measuring device with an optical cell container for measuring the cloud point of a polymer solution.

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

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

[Explanation of symbols]

 1 ... Optical cell 2 ... Optical window 5 ... Pressure gauge 7 ... Light source 8 ... Light receiver

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C11D 7/50 D01D 5/08 A 7199-3B D01F 6/04 E 7199-3B (31) Priority Claim number Japanese Patent Application No. 3-288766 (32) Priority Date No. 3 (1991) November 5 (33) Country of priority claim Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-4538 (32) Priority Hihei 4 (1992) January 14 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-4780 (32) Priority Day Hei 4 (1992) January 14 (33) ) Priority claiming country Japan (JP) (31) Priority claiming number Japanese Patent Application No. 4-4936 (32) Priority date Hei 4 (1992) January 14 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese patent application No. 4-4938 (32) Priority date Hei 4 (1992) January 14 (33) Country of priority claim Japan (JP) (31) Priority claim number Hira 4-19096 (32) Priority date Hira 4 (1992) February 4 (33) Priority claiming country Japan (JP) (72) Inventor Yoshiaki Nakayama 6-4100 Asahi-cho, Nobeoka-shi, Miyazaki Asahi Kasei Kogyo Co., Ltd. In-house (72) Inventor Kenji Kiyo, 6-4100 Asahi-cho, Nobeoka-shi, Miyazaki Prefecture Asahi Kasei Kogyo Co., Ltd.

Claims (17)

[Claims] 1. A mixed solvent comprising a solvent consisting essentially of bromochloromethane and / or 1,2-dichloroethylene and a cosolvent, wherein the cosolvent is carbon dioxide, sulfur hexafluoride, difluorochloromethane, 1 , 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, tetradecafluorohexane Selected from one or more members of the group, and the proportion of the cosolvent contained in the mixed solvent is 3 to 6
A halogen-based solvent characterized by being 5 wt%. 2. Substantially bromochloromethane and 1,2-
2. A halogen-based solvent according to claim 1, which 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 wt%. 3. The ratio of the cosolvent contained in the mixed solvent is 1
It is 0-30 wt%, The claim 1 or 2 characterized by the above-mentioned.
The halogen-based solvent described. 4. A propylene oxide as a stabilizer,
1,2-butylene oxide, nitromethane, a phosphite represented by the structural formula (I), a diphosphite represented by the structural formula (2), or a diphosphite represented by the structural formula (3), or one of them. The above is included in 0.001 to 5 wt% of the mixed solvent.
The halogen-based solvent according to any one of 1 to 3. [Chemical 1] [Chemical 2] [Chemical 3] 5. A polyolefin solution prepared at high temperature and high pressure, wherein the halogen-based solvent according to any one of claims 1 to 4 is used as a solvent, and the polyolefin concentration in the polyolefin solution is 5 to 25 wt%. A polyolefin solution characterized by: 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 isomer in 1,2-dichloroethylene is 30 to 40 wt%. 9. A method for producing a fibrillated polyolefin three-dimensional fiber by allowing a polyolefin solution prepared at high temperature and high pressure to pass through a reduced pressure orifice, a reduced pressure chamber, and a spinneret and then released into a room temperature and normal pressure region to produce a fibrillated polyolefin three-dimensional fiber. As a mixed solvent consisting essentially of bromochloromethane and / or 1,2-dichloroethylene and a cosolvent, the cosolvent is 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-2,2,3,
3,3-pentafluoropropane, 1,3-dichloro-
1,2,2,3,3-pentafluoropropane, dodecafluoropentane, selected from the group consisting of tetradecafluorohexane one or more, the proportion contained in the cosolvent mixed solvent is 3 to 65 wt% And a polyolefin concentration in the polyolefin solution is 5 to 25 wt%. 10. A mixed solvent composed essentially of a binary solvent consisting of bromochloromethane and 1,2-dichloroethylene and a cosolvent is used as the solvent, and the proportion of bromochloromethane in the binary solvent is 40 to 75 wt. %, And the method for producing a polyolefin three-dimensional fiber according to claim 9. 11. The method for producing a three-dimensional polyolefin fiber according to claim 9, wherein the content of the cosolvent in the mixed solvent is 10 to 30 wt%. 12. Stabilizers such as propylene oxide, 1,2-butylene oxide, nitromethane, phosphite represented by structural formula (1), diphosphite represented by structural formula (2), and structural formula (3). 10. One or more selected from the group consisting of diphosphites represented by 0.001 to 5 wt% of the mixed solvent.
11. The method for producing a polyolefin three-dimensional fiber according to any one of 1 to 11. [Chemical 4] [Chemical 5] [Chemical 6] 13. The trans isomer in 1,2-dichloroethylene is 30 to 40 wt%.
13. The method for producing a polyolefin three-dimensional fiber according to any one of 1 to 12. 14. A mixed solvent consisting essentially of 80 to 90 wt% bromochloromethane and 20 to 10 wt% carbon dioxide is used as a solvent, and the polyolefin concentration in the solution is 10 to 20 wt%. The method for producing a polyolefin three-dimensional fiber according to claim 9. 15. Substantially 75-85 wt% bromochloromethane and 25-15 wt% 1,1,1,2 as solvent.
The method for producing a three-dimensional polyolefin fiber according to claim 9, wherein a mixed solvent of tetrafluoroethane is used and the concentration of the polyolefin in the solution is 10 to 20 wt%. 16. The method for producing a polyethylene three-dimensional 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.