JPH0445809A - Filter medium - Google Patents

Abstract

PURPOSE:To obtain a filter medium excellent in resistance to heat and chemicals by spinning the specified polyether-based copolymer consisting of repeating units with the composition ratio controlled in a specified range and exhibiting a specified melt viscosity as the material and heat-treating the product. CONSTITUTION:A polyether-based copolymer (e.g. obtained by reacting dihalogenobenzonitrile with the alkali metal compd. of 4,4'-bisphenol in the presence of a neutral polar solvent and copolymerizing the reaction product and 4,4'-dihalogenobenzophenone) consisting of the repeating units shown by formulas I and II, in which the composition ratio of the repeating units (molar ratio of (I) to (I+II)) is controlled to 0.1-0.4 and having 3,000-50,000 poise melt viscosity at 400 deg.C is spun and heat-treated to obtain the fiber having 1-100 denier and from which this filter medium is obtained. The filter medium is excellent in resistance to heat and chemicals, and retains its strength even under severe conditions at high temp. and humidity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a filter material, and more specifically, a filter material made of polyneedle copolymer fibers, for example, suitably used in the field of filters for rivers. Concerning filter media.

[Prior art and the problem to be solved by the invention] Conventionally, filtration media that require #passion and chemical resistance include fluorine thread resin #1laC tetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl hydroxide, etc. Nyledel copolymer (PEA), detrafluoroethylene-ethylene copolymer (ETFE)] are used. However, the strength of these fluororesin fibers at room temperature is 1 to 3 g/tenier, and the strength decreases to Ig/tenier at temperatures as high as 150 DEG C. or higher. Therefore, it is not appropriate to use the fluororesin fibers in filter media that are used under high temperature conditions. Also, +i
The fluororesin that is the raw material for the fiber described in ij.
2.3, the weight of the filter material itself is increased, which is a disadvantage.

On the other hand, if we only consider the heat resistance of aramid resin fibers (especially meta-aramid fibers), which are strong and heat resistant, and those used in grouper filters such as exhaust gas filters, we can say that these fibers have a temperature of 2211℃. Well, you can use it.

However, in the case of a Haku filter, sulfuric acid is produced to filter out powder present in the high-temperature exhaust gas produced when coal or heavy oil is burned, and this produces sulfuric acid, which hydrolyzes the aramid fibers. It dissolves and reduces its durability. Also, since this fiber has a weakness against alkalis,
It is not preferred as an alkali-resistant filter.

In response to these, Japanese Patent Publication No. 52-30609 proposes the use of a fabric made of polyphenylene sulfite filaments for industrial filters.

This fabric loses its excellent properties when exposed to strong chemicals such as nitric acid, or has the property of easily breaking into Cl when subjected to mechanical abrasion, twisting, or bending. Furthermore, in filters used in the electrical industry, etc., ions (NaCU-) are often eluted, making it difficult to apply to such fields.

Currently used m-fibers for filter media, such as the above-mentioned fluororesin fibers, have good chemical resistance, but have low strength, especially at high temperatures.B) Aramid fibers have good heat resistance. However, polyphenylene sulfite fibers have the disadvantage of poor chemical resistance to high-temperature alkalis and acids, and even though polyphenylene sulfite fibers have good chemical resistance, they have weaknesses in mechanical abrasion, bending, and twisting.

The present invention has been made based on the above circumstances.

The object of the present invention is to have excellent heat resistance and strong chemical resistance, and to strongly maintain the properties even under harsh environments such as temperature and humidity, and to prevent impurities such as ions and extracts from being eluted from the fiber itself. Our purpose is to provide filter media.

[Means for Solving the Problem]; In order to achieve and solve the problem of i0, the structure of the present invention includes a repeating unit represented by the following formula and a repeating unit represented by the following formula (II) (II
) consisting of repeating units represented by the formula (I), and the composition ratio of the repeating cIt position represented by the formula (I) [molar ratio: (I)/((
I) + (TI)) Spinning a polyether copolymer having a concentration of 0.15 to 0.40 mol and a melt viscosity of 3 to 5 (1,0011 voices) at 400°C. The filter material is made of a 1 to 100 denier mm+1 film that has been subjected to heat treatment after being heated.

The filter medium of the present invention is formed from fibers having a specific thickness, which are obtained by spinning a specific polyether copolymer and heat-treating the same. The following will be explained in order.

Polyneedle-based copolymer - An important point in the polyneedle-based copolymer that is the raw material for the filter medium of the present invention is that the polyether-based copolymer or the repeating unit represented by the formula (I) and the above-mentioned It consists of a repeating unit represented by formula (II), and the content ratio or composition ratio of the repeating unit represented by formula (1) [molar ratio, (I)/((I)+(II))]
is in the range of 0.15 to 0, 4f+, and the formula (IT)
The content or composition ratio of the repeating unit expressed as [molar ratio, (II)/((I)+(II))][1,85
~0.60.

If the composition ratio or cell ratio of the repeating units represented by formula (I) is less than 0.15, the glass transition temperature of the polyether copolymer will become low, resulting in a decrease in heat resistance or a high melting point. This may lead to deterioration of spinnability. -・way, fl
If it exceeds 40, the polyether copolymer will lose its crystallinity and its heat resistance and solvent resistance will decrease.

In addition, the polyneedle copolymer described in ■ij is heated at a temperature of 4 (1
The melt viscosity at 0°C (zero shear viscosity) is 3, [100
~50,000 voices.

A low molecular weight copolymer having a melt viscosity of less than 3,000 voices may not be able to achieve sufficient heat resistance and mechanical strength.

- On the other hand, if it exceeds 50,000 voices, the spinnability may deteriorate.

The polyether copolymer used in the present invention has a crystal melting point of, for example, about 330 to 400°C, has high crystallinity, has a sufficient polymericity 7ii, and exhibits sufficient heat resistance.

A polyneedle copolymer having such excellent properties can be produced as follows.

- Production of polyether copolymer - The polyether copolymer is produced by, for example, combining an alkali metal compound of cyhalochenobensoni-1-lyl and 4,4'-hyphenol in the presence of a neutral polar solvent. After reacting,
It can be obtained by carrying out a copolymerization reaction between the reaction product and 4.4'-dihalogenol\triphenone.

Examples of the cyhalogenobennyl-1-lyl include:
24-cyhalogenobennitrile represented by the following formula; (wherein, X is a halogen atom f);

Examples include 2,6-cyhalochenopenzonitrile represented by N (in the formula, X has the same meaning as above)-C.

Among these, preferred are 2,4-dichlorohennenitrile, 2,4-difluorobensoni-1helyl, 2,
6-cyclopenzonitrile, 2,6-cyclohensonitrile, and 2,6-cyclohensonitrile are particularly preferred.

For example, to obtain the polyether copolymer by the method described above, the cyhalogenohenzonitrile and 4,4"-biphenol represented by the following formula 0 are reacted in the presence of an alkali metal compound and a neutral polar solvent. let

[■1 The alkali metal compound may be any compound as long as it can convert the above-mentioned 4,4"hyphenol into an alkali metal salt, and is not particularly limited, but preferably an alkali metal carbonate or an alkali metal hydrogen carbonate. It is.

Examples of the alkali metal carbonates include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate,
Examples include cesium carbonate.

Of these, preferred are 1-lium carbonate and potassium carbonate.

rij alkali metal charcoal water Jf, J'1! In the end,
Examples include lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, and cesium hydrogen carbonate.

Among these, preferred are sodium hydrogen carbonate and potassium hydrogen carbonate.

In the method described in f'NI, sodium carbonate and potassium carbonate are particularly preferably used among the various alkali metal compounds mentioned above.

Examples of neutral polar solvents include N,N-cymedylformamide, N,N-diethylformamide,
N,N-dimethylacetyamide, 11. N-ethylacetamito, N, N-cypropylacetamito, N,
N-dimethylbenzoic acid amide 1-, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-inbutyl-2-pyrrolidone, N-n-propyl 2 -pyrrolidone, N-n-butyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-medyru-3-methyl-2-pyrrolidone, N-ethyl-3-methyl-2-pyrrolidone, N-methyl3 .4
．． 5-trimethyl-2-pyrrolin, N-methyl-2
-piperitone, N-ethyl-2-pyrrolone, N-isopropyl-2-piperidone, N-methyl-6-methyl-2-piperidone, N-methyl-3-ethylpiperitone, dimethyl sulfoxide, diethyl sulfoxide, l
-Methyl-1-oxosulfolane, l-ethyl-1-oxosulfolane, l-phenyl-1-oxosulfolane, dimethylimitasolicinone, diphenylsulfone, and the like.

11'l cyhalogenohenennyl-1-lyl and the above 4゜4
The usage ratio of ゛-biphenol and the alkali metal compound is a molar ratio to the 4,4゛-biphenol,
The above-mentioned cyhalogenohensoni is 1 to 1, usually 0. ]5~
When the alkali metal compound is the alkali metal carbonate, the ratio is usually 1.03 to 2.50, preferably 1.05. The ratio is 1.25 to 1.25, and when the alkali metal carbonate is used, the ratio is usually twice that when the alkali metal carbonate is used.

Is there any particular restriction on the amount of the neutral polar solvent used? Usually, the amount of the dihalogenobenzonitrile and the 4.
The amount is selected in the range of 200 to 2.000 parts by weight per 100 parts by weight of the 4°-biphenol and the alkali metal compound.

In the method described in item 3, the reaction product obtained by reacting the dihalogenobenzonitrile with the 4,4'-biphenol in the presence of the alkali metal compound and the neutral polar solvent; React with 4'-dihalogenobenzophenone.

In obtaining the polyether copolymer, the 4,4'-dihalogenohensiphenone used is represented by the following formula 6 (where, X has the same meaning as above). Compounds, more specifically, 4,4゛-cyclohensophenone, 4,4゛cyclohensophenone,
Examples include 4-chloro-4'fluorobentzphenone.

In the above method, the 4,4'-dihalogenohensiphenone has a molar ratio of the dihalogenobenzonitrile to the 4,4°-biphenol of No. 411, or
Usually 0.98-1.02, preferably 1.00-1.
Use as old as possible.

In order to obtain the polyether copolymer by the method described above, for example, the dihalogenobenzonitrile and the 4.4'-hyphenol are added to the neutral polar solvent,
The alkali metal compound is added at the same time to react the cyhalogenoenzonyl-1-lyl and the 4.4'-biphenol, and then the 4,4'-dihalogenohensiphenone is further added. Usually 150-380℃
The series of reactions is carried out at a temperature preferably in the range of 180-330°C. If the reaction temperature is less than 150°C, the reaction rate is too slow to be practical, and if it exceeds 380°C, side reactions may occur.

In addition, the reaction time of this series of reactions is usually o, + ~
l1111! i, preferably 111! between p~5
n! j 1 lil.

For example, the polyether copolymer obtained in this manner is composed of a repeating unit represented by the above formula (I) and a repeating unit represented by the above formula (H), and the repeating unit represented by the above formula (I) Unit composition ratio is 0.15
It is a copolymer having a melt viscosity of 3,000 to 50,000 voices at a temperature of 400°C.

46. After the above reaction is completed, the polyether copolymer may contain alkali metal salts produced during the polycondensation reaction. Is it possible to remove the alkali metal salt to a considerable extent from the polyether copolymer by ordinary polymer purification operations? When necessary, the polyether copolymer after the completion of the i′rI′ integration reaction is treated with an organic acid or an inorganic acid-containing,
It is best to wash with an acidic aqueous solution adjusted to pH 3.5 or higher.

In terms of organic spirits and acidic acid, for example, monocarboxylic alcohols such as acetic acid, acetic acid, monochloro S=1, dichloroacetic acid, trichloroacetic acid, propionic acid, and dicarboxylic acids such as oxalic acid and malonic acid may be mentioned. Ru. Among these, oxalic acid and other cycalphon-resistant are preferred, and oxalic acid is preferred for cattle. Incidentally, one type of these organic acids can be used alone, or two or more types can be used in combination.

Examples of the inorganic acids include hydrochloric acid, sulfuric acid, phosphorous acid, and the like. Among these, hydrochloric acid is preferred.

It is preferable to adjust the concentration of the solution containing these substances to a pH of 1.5 or higher, or to determine the type of sake.

The time for washing the polyneedle copolymer with the m++ aqueous solution is sufficient for the content of alkali metal salt in the polyether copolymer to reach the desired value, for example, 5 [1p I)m or less. be. In addition, in order to promote the desalination effect by washing, the mixture of the acidic aqueous solution and the polyether copolymer may be heated or heated under pressure during washing.

After washing with an acidic aqueous solution, in order to remove the acid from the polyether copolymer, pure water, ion exchange water, /KW
It is recommended that you wash every 7th and 11th minute.

Next, this polyether copolymer is spun.

Spinning The polyneedle copolymer can be spun using a conventionally known melt spinning method.

In order to carry out melt spinning, the spinning temperature is usually 30-7 higher than the crystal melting point (Tm) of the polyether copolymer.
[Spinning is carried out at 1°C higher temperature and using a normal spinneret.

If the spinning temperature is lower than the melting point of the polyether copolymer by 1°C, the spinning temperature will decrease and the yarn diameter will decrease. Sometimes the joints become difficult.・If the temperature exceeds 70° C. higher than the melting point of the polyneedle copolymer, the quality of the spun yarn may deteriorate.

However, the key is to completely melt the polyneedle copolymer before spinning, and if the polyether copolymer is spun without being completely melted, the mechanical strength of the fiber will decrease.

For the cooling power method and the take-up method, known techniques can be suitably adopted.

In cooling, according to the present invention, it is not necessarily necessary to provide a cooling liquid bath, and cooling and solidification can be suitably performed even in air.

Note that there are no particular restrictions on the spinning device, winding device, etc. that can be used in the filter medium of the present invention, and any of those used in conventional methods can be suitably used.

After spinning the polyneedle copolymer as described above, it is preferable to carry out stretching as described in detail below.

For drawing the spun yarn of the polyether copolymer obtained in steps 1-1 and 1-, any conventionally used drawing device can be suitably used. ↓In terms of L type,
For example, a non-contact stretching device using heated water/air, a heating medium electric heater, etc., a heating multi-stage stretching device equipped with one or more stages of contact heaters, etc. can be suitably used.

In any case, in the method for producing the polyether copolymer fiber used in the filter medium of the present invention, the drawing temperature is 100% higher than the glass transition temperature of the polyether copolymer.
~30°C higher temperature range is required. If the stretching temperature is less than 10° C. higher than the glass transition temperature of the polyether copolymer, the stretchability may decrease and a sufficient stretching effect may not be obtained. On the other hand, if the stretching temperature exceeds a temperature that is 30° C. higher than the glass transition temperature of the polyether copolymer, fuzz or lapping may occur during the stretching process, making stable stretching impossible.

Therefore, in producing the #a fiber of the polyether copolymer used in the present invention, the stretching ratio is 1.5.
As mentioned above, it is preferably 2 to 1O. If this stretching ratio is less than 1.5, fibers with a predetermined strength may not be obtained.

After the polyether copolymer is spun as described above and preferably further stretched, it is subjected to heat treatment as detailed below.

-Heat treatment- The heat treatment can be carried out using known techniques and equipment, for example, a roller or the like is often used.

The heat treatment temperature can be suitably carried out in a temperature range higher than the crystallization temperature and lower than the melting point of the polyether copolymer.

By performing this heat treatment, the polyneedle copolymer is crystallized, and the thermal stability, strength, and drug resistance of the resulting polyneedle copolymer fiber are further improved.

Note that this heat treatment may be performed under tension of the drawn yarn obtained by performing the above-mentioned drawing, or may be performed under no tension.

1. Filtering Material The filtration material of the present invention can be manufactured from fibers obtained by spinning, stretching, and heat-treating the polyether copolymer.

An important point regarding the polyether copolymer fiber used in the present invention is that the thickness of the polyether copolymer fiber is 1
~100 denier.

If it is less than 1 denier, fluff may occur during spinning,
Furthermore, when used as a filter material, it is subject to greater deterioration due to abrasion and ultraviolet rays, resulting in decreased durability. On the other hand, if it exceeds 100 denier, the mechanical properties, heat resistance, and chemical resistance of the polyether copolymer fibers will be good, but the filtrate will be large when used as a filter material, and its uses will be limited.

Therefore, in order to construct a filter material that is easy to handle, has a wide range of uses, and has excellent durability, heat resistance, and chemical resistance, it is necessary to have a denier in the range of 1 to 100 denier. .

1 of the present invention! ! The overfill material uses polyneedle copolymer fibers having the above-mentioned specific denier value, and is made into a woven fabric.
It can be obtained by forming it into knitted or nonwoven fabrics.

In addition, depending on the use, when forming the above-mentioned textile etc.,
It is also possible to use a blended yarn of a polyether copolymer and other fibers.

rjj Pi, the woven fabric may have a woven structure such as a plain weave, a diagonal weave, or a satin weave.

The knitted fabric may have a knitted structure such as flat knitting or tuck knitting.

The filter material made of polyneedle copolymer fibers obtained as described above can be suitably used for various purposes as a filter material with excellent thermal stability, mechanical strength, and chemical resistance. can.

[Example] Next, Examples and Comparative Examples of the present invention will be shown to further specifically explain the present invention.

(Example 1) ■ Internal volume 2110 equipped with a Dean-Starck trap filled with toluene of vol., a stirring device, and an argon gas blowing pipe.
2,6-cyclopensonitrile 1,
548 g (9 mol), 4.4'-biphenol5.
! iao g (30 moles), potassium carbonate 4,561 g
(33 mol) and 50 moles of N-methylpyrrolidone were added, and the temperature was raised from room temperature to 195°C over 1 hour while blowing argon gas.

After heating for 5℃, add a small amount of toluene and mix the resulting water.
) was removed.

Next, the reaction was carried out at a temperature of 1F and 195℃ for 30 minutes, and then 4.58% of 4.4′-difluoropennephenone
2 g (21 liters) of N-methylpyrroline 7()
A solution dissolved in C2 was added to C2, and the reaction was carried out for a further 1 hour.

After the reaction process, the 41-component was pulverized with Tsulenta (manufactured by Waninck Rei), washed with water and methanol, and dried to obtain a white powdery copolymer! [1,
0 kg (yield: 8%) was obtained.

When the properties of this copolymer were measured, it was found that the temperature of 40
Melt roughness at 0°C (upper shear viscosity) 16, O
En Boyce, Callas transition temperature 185°C1 Crystal melting point;) 4
8°C5 Pyrolysis start temperature 56fl °C (in air, 5%
There was a heavy weight.

Additionally, this copolymer had the following repeating units.

(I)/(I)+(u)=0.3.

■Take 1'' Σ1 construction The polyether copolymer obtained in the above (■) was heated at 400°.
After heating and melting to C, the inner diameter is 1. [, 1 mm, length], [) Using a ml 11 nozzle, the nozzle temperature is 39
Spinning was carried out at 0°C.

Thereafter, the spun yarn was passed through a 30 cm long heating cylinder maintained at a temperature of 300° C., cooled in air, and wound at a speed of 400 ml per minute.

Next, this undrawn yarn was subjected to a heat treatment for stretching 4 times between a hot roller at a temperature of 14f1°C and a hot roller at 250°C to obtain a drawn yarn of 2 denier.

The strength of this yarn at room temperature is 8. fl g/denier, elongation was 20%, and dry heat shrinkage was 4.5% at 220'C. Also, the strength in ]5[] 'C dry heat is 5.2
g/denier. In addition, the measurement of item 8 L1 will be 6.11! ; −1−′+ [′, l l :I
-81.

This thread's sulfuric acid (40%, 95℃, 1() old +r) retention -1A, alkali resistance (power sorter 4()%, 95℃
, ]DIlbr) retention rate is + [110% 73°. In addition, liN Kt, FPlj (4i',
1%, 95'C, 1oohr) Retention rate means that 40% sulfuric acid is attached to a sample at a ratio of 10% of heavy weight, and the retention rate is 1% in a dry mold at q5°C. ] The ratio of the strength of the sample measured after aging to the strength of the sample before adhesion to sulfuric acid, and the alkali resistance (strength sorter 40%, 1) at 5°C 91
υυ) 1" retention rate is determined by applying a 40% force sorter to the sample.
1% of the nail part, and put it in a dry mold at 95°C.
] It is the ratio of the strength of the sample measured after applying the force to the strength of the sample before arrival at the force + 1 meter.

Using this fiber, a 5-ply satin fabric of 100 wood/inch was produced.

The heat resistance (tJL) of this fabric is 240°C, and the resistance and alkalinity are both 100%, same as the fiber.
There was.

(Example 2) In Example 1, the stretching ratio was changed to 3 times (C1).
A drawn yarn of 2.5 denier was obtained.

This fiber was evaluated in the same manner as in Example 1 above.

Further, a woven fabric was produced in the same manner as in Example 1, and the evaluation was 1-1.

The results are shown in Table 1.

(Comparative Example 1) Using 2 denier meta-aramid fiber as the raw material mM, the evaluation was made in the same manner as in Example 1.

Further, a woven fabric was produced and evaluated in the same manner as in Example 1.

The results are shown in Table 1.

In addition, 10% by weight of 40% sulfuric acid was attached to this fabric, and 1
The strength retention rate after being placed in a dry mold at 513° C. for 1 hour was 5%. There were also holes in some parts.

[Effects of the Invention] (1) According to the present invention, t! It is heat resistant because it is spun and heat-treated using a specific polyether copolymer that is composed of specific repeating units in a specific range of Ml composition and has a specific melt viscosity as a raw material for the passage material. It is possible to provide a filtration material that has excellent chemical resistance, excellent strength retention under harsh environments such as temperature and humidity, and which does not elute impurities such as ions or eluates from itself.

Claims (1)

[Claims] (1) The following formula (I); ▲There are mathematical formulas, chemical formulas, tables, etc.▼The repeating unit represented by (I) and the following formula (II); ▲Mathematical formula,
There are chemical formulas, tables, etc. ▼ The composition ratio of the repeating units represented by the formula (I) [molar ratio: (I)/{(
I) + (II)}] is 0.15 to 0.40 mol, and the melt viscosity at 400°C is 3,000 to 50
A filtration material comprising fibers of 1 to 100 deniers which are heat-treated after spinning a polyether copolymer having a poise strength of 1,000 poise.