JPS63182500A - Special paper like sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a special paper-like sheet. Furthermore, for more details,
Especially water resistant, heat resistant, oil resistant and flame retardant.

Concerning special paper-like sheets with high radiation resistance, etc.

[Conventional technology]

In recent years, paper-like sheet materials have been used not only for conventional purposes such as recording paper, paper, and wrapping paper, but also for a wide variety of purposes.

It is beginning to expand into various fields. Typical fields include electrical fields such as capacitors, and various types of filter paper.

etc., are widely deployed.

The main properties required of paper in this field are: ■ heat resistance, ■ combination of strength and flexibility, ■ water resistance, and ■ little falling off from paper-like sheets. 9. Even after washing, there is little falling off from the paper-like sheet, ■Oil resistance.

■Flame retardant grade 1.

Various methods have been disclosed to provide such properties. Representative examples are as follows.

That is, the sheet-like material disclosed in Japanese Patent Publication No. 57-24440 etc. is mainly composed of a highly heat-resistant organic material and an inorganic material, so it is somewhat brittle, and there are also problems in that the inorganic material easily falls off. , it is somewhat insufficient for deployment in the so-called high-tech field.

Further, the sheet-like materials disclosed in Japanese Patent Publication No. 57-400 and the like are mainly related to gypsum paper made of natural pulp and gypsum. Gypsum paper certainly has high heat resistance, but it has a major drawback in that it is difficult to achieve both strength and flexibility, which are the characteristics of paper.

Although a method for producing a nonwoven fabric made of polyphenylene sluide and heat-resistant fibers is disclosed in JP-A-61-2.89162, the polyphenylene sluide fibers used in this publication are essential to be undrawn fibers. It is. Although undrawn fibers do have the advantage of being able to be fused at low temperatures, they have the major disadvantage of poor heat resistance at high temperatures. The fibers are extremely weak unless they are stretched to some extent.

In particular, polyphenylene sulide and polyethylene terephthalate, which have aromatic rings in their molecules and have no hydrogen bonds or ionic bonds between nine molecules, exhibit their original characteristics only after stretching. Therefore, especially once exposed to high temperatures.

It becomes extremely brittle, especially if subjected to repeated fatigue.

It breaks down easily and does not maintain its fibrous form.

Furthermore, undrawn fibers have the disadvantage of extremely high shrinkage. Therefore, even if such fibers are used as adhesives for sheet products, they not only lose their adhesion effect, but also have the major disadvantage that they themselves fall off from the sheet, especially at high temperatures. Further, unless the processing conditions are extremely limited, serious problems such as deformation of the sheet during the processing will occur.

Furthermore, the object of this publication is a so-called nonwoven fabric, not a single paper-like sheet.

In other words, although these paper-like special sheet materials have made progress compared to conventional paper made of cellulose, they still have the following major problems before they can be used more widely.

That is.

■Poor heat resistance.

■Poor water resistance. In particular, high temperature water resistance is poor.

0 Strength and flexibility are not compatible.

■Many objects fall off from the paper sheet. In particular, when repeated fatigue tests are performed, an extremely large number of substances fall off.

■Poor oil resistance.

■Low flame retardancy.

■Poor radiation resistance.

[Problem that the invention seeks to solve]

That is, the problems to be solved by the present invention are as follows.

That is, low heat resistance, low water resistance9 strength and flexibility-
0, oil resistance and flame retardance are low, radiation resistance is low, and a lot of material falls off from the paper.

[Means for solving problems]

In view of the current situation, the inventors of the present invention have conducted extensive studies without being bound by conventional research concepts.

We have arrived at the present invention. In order to solve this problem, the present invention has the following configuration.

(1) A special paper-like sheet, which contains at least (1) fibers made of an aromatic ring polymer and (2) polyarylene fibers having a denier of 0.3 denier or less and mainly consisting of short fibers having the following structural formula. A special paper-like sheet characterized by:

(2) The special paper sheet according to claim 1, wherein the aromatic ring-containing polymer is poly-phenylene-phthalamide, polybenzobisoxazole, or polybenzobisthiazole.

This will be described in more detail below.

It is extremely surprising that according to the present invention, it is possible to produce a paper-like special sheet material that is revolutionary in its chemical resistance and water resistance.

The special sheet material of the present invention is composed of at least two component polymers, one of which is represented by this structural formula and is hereinafter referred to as PAS. A typical example is polyphenylene sulfide fiber, and particularly preferred is a polymer whose main structural unit is poly-P-phenylene sulfide (hereinafter referred to as PPS). Such materials have the great advantage of being extremely chemical resistant and heat resistant.

Specifically, they include PPS, poly-P-phenylene sulfoxide, poly-P-phenylene sulfone, and copolymers and modified products thereof.

It goes without saying that various additives may be added to the polymer. In addition, when particularly increasing radiation resistance, diphenyl ether derivatives (diphenyl ether with various alkyl groups attached,
Those in which a large number of aromatic rings are bonded through ether bonds, and those in which a large number of aromatic rings are bonded through ether bonds,
moreover.

It is also particularly preferable to add alkyl groups, aromatic rings, etc.).

There is also a sulfonic acid group on the aryl group of PAS fiber.

Polymers to which carboxylic acid groups or the like have been added are also particularly preferred because they have particularly high hydrophilicity and are therefore easy to wet paper-making, are easily colored, and are difficult to decolor.

Conventionally known methods can be applied to the method for producing such a polymer, and there are no particular limitations. Also, to improve the functionality of the special paper-like sheet of the present invention.

Conventionally known methods can be applied to add a sulfonic acid group or the like to a phenyl group, and there is no restriction in any way. Particularly preferred methods for the addition of sulfonic acid groups are9, for example, treatment of fibers with sulfur trioxide,1 treatment with fuming sulfuric acid, treatment with sulfuric acid, treatment with chlorosulfonic acid.

The first type of combined treatment with carbon tetrachloride and chlorosulfonic acid produces PPS by adding a sulfonic acid group to the arylene group.
It is also an extremely effective method to use fibers containing sulfonic acid groups. It is also extremely effective to add a sulfonic acid group to a monomer and copolymerize the monomer with a monomer to which no sulfonic acid group is added.

A particularly preferred method for adding sulfonic acid groups, etc. to PAS fibers is to carry out the treatment after forming the fibers, especially for multi-surface fibers such as microfine fibers and multi-hollow fibers (lotus root fibers). be.

If such a method is adopted, the reaction time can be reduced.

Additionally, since it can be carried out at relatively low temperatures, there are fewer side reactions.

It also has the great advantage of being completely and safely possible. It goes without saying that the present invention is not limited to this method.

The constituent components of the special paper-like sheet of the present invention are small (consisting of such polymers, but P made of such polymers).
AS fibers are mainly 0.3 denier (hereinafter referred to as d) or less.

If it exceeds 0.3 d, the sheet-like material in particular will harden.

It loses flexibility and becomes easily broken.

Moreover, major drawbacks such as a decrease in tear resistance tend to occur. Also, as PAS fibers become thicker, they become colored by 1, so
It is difficult to mold PAS fibers with high white skin. Also, high fineness makes it difficult to make paper.

Therefore, the fineness of the PAS fiber is 0.3 d or less, particularly preferably 0.1 d or less. More preferable is 0.07
d or less. It should be noted that the PAS fibers do not need to have a uniform fineness in the length direction.

In short, it is sufficient if some of the fibers have a fineness below this level.

That is, the thickness of the PAS fibers may vary in the length direction, or may be branched into fibrils. This means that the form of the fiber is not limited to PAS fibers only, and fibers made of aromatic ring polymers may also have a similar form.

The method for producing such PAS fibers is not particularly limited, and conventionally known methods can be widely applied. For example, so-called polymer array fibers and polymer blend fibers.

By making compressible fibers such as peelable fibers, and then subjecting them to peeling treatment or removing at least one component,
An effective method for producing ultrafine fibers can be adopted.

Further, it is also a very effective means to make ultrafine fibers by means such as melt blowing and flash spinning. Also, among the shrinkable fibers, particularly core-sheath fibers.

By removing at least one component of polymer array fibers, polymer blend fibers, etc., hollow fibers are made, especially multi-hollow fibers (lotus root-shaped fibers) with a large number of hollow holes, and then the fibers are beaten. It is also an extremely effective method to form fibers into fibrillar branched fibers by treatment. It is also an extremely effective method to treat such fibers with a high-pressure fluid, such as a water jet, to form fibers branched into fibrid shapes.

The PAS fibers used in the special paper-like sheet of the present invention are mainly composed of short fibers. If short fibers are used as the main constituent fibers, the basis weight will be uniform, and the product can be made flexible. It is easy to demonstrate the great effect of increasing the ability.

Fiber length varies greatly depending on purpose and use, but 0°5f
1 to 150 fins is preferable, and especially when producing a special paper-like sheet with high uniformity, 0.5n to 25 fins is preferable. Also, when making high-strength special paper-like sheets.

It is preferable to add longer fibers. in any case,
Within this range, the uniformity was excellent. and.

A paper-like sheet material with good flexibility and excellent flexibility can be obtained.

The PAS microfibers are preferably stretched.

Particularly preferably, the stretching is 1.5 times or more. More preferably, it is stretched twice or more. If the stretching ratio is less than 1.5, the yarn becomes extremely brittle. In particular, the yarn becomes weak when exposed to temperatures above 90°C. Furthermore, if the yarn is exposed to temperatures of 90° C. or higher without any tension, it will shrink significantly and the yarn will become extremely weak. In other words,
When heat resistance is required, it is preferable to stretch 1.5 times or more. In particular, when heat resistance and sheet strength are required, it is preferable to use PAS microfibers that are highly stretched to twice or more and crystallized.

In order to improve the heat resistance, chemical resistance, etc. of the PAS fiber,
Furthermore, in order to impart hydrophilicity and improve paper-making properties,
Add plasma treatment and also.

It is also very good to modify PAS by oxidizing the sulfur component of PAS, such as polyphenylene sulfonation or polyphenylene sulfoxidation.

Incidentally, the fibers of the present invention naturally include those in which a side chain such as 10H group or one molecule within one molecule is bonded to PAS during such a treatment process. Also related to such fibers. It goes without saying that a sulfonic acid group or the like may be attached. However, such treatment increases the water absorption rate and moisture absorption rate of the special sheet material.
There will also be fields where it is inappropriate for the purpose of use, so it is important to consider the purpose of use.

It is preferable to carry out such processing depending on the purpose.

Next, it is used at least in the present invention. The other aromatic ring-containing polymer fibrous material will be described. Particularly preferred aromatic ring-containing polymers have a melting point of 300°C or higher. If it is less than 300°C, the heat resistance of the entire special sheet-like product will be lowered, which is not preferable.

A particularly preferred aromatic ring-containing polymer is a wholly aromatic ring polymer, or a polymer consisting of an aromatic ring and a heterocycle. A typical example of such a material is aromatic polyamide. Poly-m-phenylene-iso-phthalamide (hereinafter referred to as PMP)
I), poly-p-phenylene-tere-phthalamide (hereinafter referred to as PPPT), poly-P-penzamide.

, copolymers of such polymers, and polymers represented by the structural formula below.

Further, as the aromatic imide, those shown in the following structural formula are particularly preferable.

CI″13 is also a starting material for imide. Particularly preferred are diamine components in which the aromatic rings are bonded to each other by a fulphyte bond, a sulfone bond, or the like.

Further, as the aromatic amide-imide, those shown in the following structural formula are particularly preferable.

Here, Z is one of the following.

Y is represented by any of the following.

-o--co--soλ- Moreover, among those in which aromatic rings are mainly bonded through ether bonds, those represented by the following structural formulas are particularly preferable.

Moreover, among those in which aromatic rings are mainly bonded through ester bonds, those shown by the following structural formula are particularly preferable.

mlsm2s1M3 = 1o.

Especially preferred is polybenzobisoxazole (
Particularly preferred are those represented by the following structural formulas, such as PBO (hereinafter referred to as PBO), polybenzobisthiazole (hereinafter referred to as PBT), and polybenzimidazole (hereinafter referred to as FBI).

m I + )12- IQO Similar to PAS fibers, these fibers can take nine different forms. It may be fibrillar.

It may be thicker than ultra-fine fiber PAS* fiber. but.

It is particularly preferable that at least a portion of such fibers be thin. In particular, when a paper-like product of high quality is to be obtained, it is preferable that the fibers made of the aromatic ring polymer also have a diameter of 3 d or less. Particularly preferably, the fibers are fibrillated or are mainly composed of aromatic ring-containing polymer fibers having a diameter of 0.8 d or less.

The method for producing such fibers is not particularly limited, and conventionally known methods can be applied. The so-called flash spinning method is an extremely effective method. Further, since such fibers are easily fibrillated by mechanical treatment, it is extremely effective to make them into ultra-fine fibers by beating treatment. In addition, by injecting a high-pressure fluid, for example, a water jet stream, onto fibers made of these polymers, or by using mechanical or chemical beating treatments, ultrafine fibers or fibrillated fibers can be produced. It is also effective to do so. Another effective method is to add additives during fiber molding to facilitate fibrillation.

Therefore, particularly preferred aromatic ring-containing polymers are those that are easily fibrillated by such treatment. Good fibrillation allows for good paper making and therefore makes it easy to make good paper-like sheets.

So-called rigid fibers are easily fibrillated, and those that are not copolymerized are particularly preferred because they are easily fibrillated. In addition, non-copolymerized polymers are particularly preferred because they have high heat resistance, chemical resistance, and strength; however, even aromatic ring-containing polymers that are difficult to fibrillate can be used as a particularly effective method for producing ultrafine PAS fibers. It is.

It goes without saying that this is basically not a big problem, since so-called shrinkable fibers can be made and at least one component removed to produce ultrafine fibers or fibrillated fibers.

The special sheet material of the present invention is composed of at least two polymers, fibers made of the aromatic ring polymer and fibers made of PAS, but it also contains various other fillers, additives, papermaking aids, etc. Needless to say, it's fine to do so. One of the particularly preferred embodiments of the present invention is that PAS fibers, which are ultrafine fibers, and fibers made of an aromatic ring polymer are bonded or welded. Welding refers to melting or softening due to heat, resulting in a bonded state. The binding state of such fibers, ie.

When PAS ultrafine fibers and aromatic ring polymer are bonded together, other sizing agents, etc. are no longer necessary, improving the heat resistance of special sheet materials,
It has the great advantage of significantly improving water resistance, oil resistance, etc. Furthermore, the amount of material falling off from the special sheet-like material can be extremely reduced.

This is extremely preferable for using special sheet materials in clean applications.

Next, the ratio of PAS ultrafine fibers to fibers made of aromatic ring polymer varies greatly depending on the use of the special sheet material of the present invention, and cannot be generalized. In particular, when heat resistance is required, a higher proportion of fibers made of aromatic ring-containing polymers is preferred. On the other hand, if particularly chemical resistance is required, a higher proportion of PAS microfibers is preferred.

In any case, it should be determined depending on the purpose and use. However, the ratio of fibers made of aromatic ring polymer to the entire special sheet material is at least 10% by weight (
(hereinafter referred to as wt%) or more is preferable. l
If it is less than 0 wt%, no significant improvement in physical properties such as heat resistance can be expected. Particularly preferably, 50 wt% or more, and even more preferably 80 wt%, of the fiber is composed of an aromatic ring-containing polymer. By setting such a ratio, heat resistance in particular is greatly improved. On the other hand, it is preferable that the content of PAS ultrafine fibers is at least 2 wt% or more.

If the amount is less than 2 wt%, the effect of adding PAS fibers is not so great.

The ratio of PAS ultrafine fibers varies greatly depending on the denier of the PAS ultrafine fibers, so the denier of the fibers and
Taking into consideration the dispersion state (dispersibility) in special sheet materials,
The proportion of PAS microfibers should be optimized.

Of course, lubricants and fillers.

It goes without saying that various additives such as a whitening agent and various inorganic fine particles serving as an insulator may be added.

It is also effective to add fibrillated substances other than those mentioned above.

The basis weight (basis weight) and density of the special paper-like sheet of the invention vary greatly depending on its use, and cannot be generalized.

Laws should be regulated as appropriate depending on the purpose.

When making the special paper-like sheet of the present invention, as a guideline for the density of PAS fibers, in the case of filter paper etc., it is preferable that the density is low, while in the case of a special paper-like sheet like medium-quality paper, it is 0.6
~0.7g/cra, 0.9~Ig/ad for high-quality paper-like special paper-like sheets, and 1.2~1.4g/- especially for art paper-like special paper-like sheets. is particularly preferred. Materials with these densities can be obtained by appropriately treating the sheet-like material in the paper-making process or in subsequent steps.

Next, the method for manufacturing the special paper-like sheet of the present invention will be briefly described.

Regarding PAS fibers and fibers made of aromatic ring polymers,
The methods already described are particularly preferred methods. Particularly preferably, wet paper making is performed using such a material. It goes without saying that static electricity or the like may be used to form a sheet-like material. PAS fibers may be made extremely fine before paper making, or may be made very fine after paper making. Especially polymer array fibers,
In the case of micronized fibers such as polymer blend fibers, it is more preferable to cut the fibers and make them ultra-fine.

It is easy to make a special paper-like sheet that is easy to make.

There are no particular limitations on paper making, and conventional methods can be used without any problems. In addition, during the paper making process, and before and after that, as appropriate.

There is no problem in performing hot pressing, fusing the PAS ultrafine fibers and the aromatic ring polymer, gloss treatment (treatment to give gloss), smoothing treatment, etc.

The present invention will be explained in more detail with reference to Examples below. It goes without saying that the present invention is not limited to these embodiments.

〔Example〕

This will be explained in more detail below with reference to Examples.

Example 1 Polymer array fibers were made under the following conditions.

■Sea component - polystyrene ■Island component = PPS ■Island/sea (weight ratio) = 50150 ■Number of islands = 36 ■Spinning temperature = 315℃ ■Spinning speed = 1000 m/min ■Stretching ratio -2,2 ■Stretching temperature - 90℃ ■Single fiber denier of the obtained polymer-aligned fibers -3,5
d Next, the fibers are pulled together into a tow shape, further cut into approximately 5 fins, and the short fibers are further treated with trichloride to remove the polystyrene component, resulting in ultrafine PAS short fibers with a single fiber of approximately 0°1d. The resulting zero-order synthetic pulp mainly composed of PMP I manufactured by DuPont was mixed and stirred in water so that the former was 10 wt% and the latter was 90 wt%, and dispersed in water.
The mixture was poured onto a stainless steel wire gauze and paper was made to obtain a sheet-like product. The dispersion of synthetic pulp and ultrafine PAS staple fibers was uniformly dispersed, so papermaking was easy.

Next, the sheet material was passed through a dryer at 315°C.

The synthetic pulp and ultrafine PAS short fibers were heat-fused to form the special paper-like sheet of the present invention.

This special paper-like sheet has a slight yellow tinge.

It has excellent heat resistance, retaining its shape well even when left in air at 200°C (heat resistance test was carried out by cutting a paper-like sheet into 3C1L width and 20cm length, and 7 lamp lengths). 15a++, and 100mm at the bottom edge of the base paper.
A creep test was performed for 1 hour under heating with a load of
We observed the breakage of the base paper and determined that it had no heat resistance if more than half of the paper was broken in one width. The sheet was cut to a width of 3C and a length of 20cm, the clamp length was set to 15 marks, a load of 20g was applied to the lower end of the base paper, and a creep test was performed in water at 50°C for 1 hour.

The breaking condition of the base paper was observed, and if more than half of the 9 width 3 cI 11 was broken, it was determined that it did not have heat resistance).

It is extremely flexible, does not change even when immersed in oil, has extremely high chemical resistance, and has excellent flame retardancy.
It also has very high electrical insulation properties.

It also has excellent radiation resistance, and can be used not only in the field of conventional paper, but also in high-grade filter paper and electrical insulation paper.

In addition, there were very few fallen substances from this special paper-like sheet, and it could be safely used for various precision filter papers.

Example 2 In Example 1, the draw ratio of the PPS composite fiber was set to 3.5.
PPS composite fibers were produced under the same conditions except that the fibers were doubled, and then made into ultrafine fibers in the same manner as in Example 1.

Next, PPS ultrafine fibers and PMP I were mixed at a mixing ratio of 15 wt% for the former and 85 wt% for the latter, and paper was made in the same manner as in Example 1. Next, 30 sheets of paper were
The material was passed between calender rolls heated to 0° C. and pressed to obtain a high-quality paper having a specific gravity of about 1 g/d and a thickness of about 50 μm. This special sheet material has heat resistance of 240°C, high water resistance, excellent bending resistance, no change even when immersed in oil, and extremely high chemical resistance.

In particular, it has excellent flame retardancy and very high electrical insulation properties.

It could be used not only in the field of conventional paper, but also in high-grade filter paper and electrical insulation paper. Further, the number of substances falling off from this special paper-like sheet was even smaller than in Example 1, and it could be sufficiently used in so-called high-tech fields.

Example 3 The special sheet-like material of Example 2 was subjected to plasma treatment to perform polyphenylene sulfonation treatment of PPS.

Surprisingly, this special sheet-like material is highly heat resistant, retaining its shape well even when left in air at 300°C.
Moreover, it had physical properties equivalent to those of Example 2.

Example 4 In Example 1, the sea and the island were replaced, and a fiber having a fineness of 1.2 d after drawing was produced. Note that the stretching ratio is 3.
I increased it six times. Both spinning and drawing were carried out smoothly. Thereafter, the fibers were cut in the same manner as in Example 1 (the fiber length of the cut was mainly 1c+a or less), and further treated with trichlene,
The island components were removed to obtain multi-hollow PAS fibers of about 0.6 d. After that, the multi-hollow P
Fibrillation of AS fibers was carried out.

Fibrillation was successfully carried out, and a fibril-like material was obtained which was partially reduced to 0.1 d or less (photographed with a scanning electron microscope and d was measured).

Next, PPPT was dissolved in concentrated sulfuric acid using a method similar to that disclosed in Japanese Patent Publication No. 55-14167, and the fibers were spun using a test spinning machine and further subjected to tension heating treatment to produce fibers with a PPPT of approximately 1.7 deniers. Ta. After that, the fibers were knitted into a plain knit, and the plain knit was first treated with high pressure water (200 kg/aJ) from both sides of the plain knit to fibrillate the PPPT.

Next, the plain knitting was released and the yarn was made into a thread again.Next, the raw yarn was cut into pieces of about 1C11 or less using a ceramic cutter. Next, the single fibers were subjected to a beating machine and further fibrillated.

Fibrillation was more thorough and better than PPS.

Next, the PPS ultrafine fibers of Example 2 were adjusted to 5wt%, the fibrillated PPS ultrafine fibers to be 10wt%, and the fibrillated PPPT to be 65wt%, and high-quality paper was produced in the same manner as in Example 2. The special sheet material was extremely smooth and flexible, and had the same characteristics as Example 2.

Furthermore, it is hardly affected by organic solvents and has excellent heat resistance, chemical resistance, water resistance, and flame retardancy. It was a sheet product.

Example 5 The PPS microfiber of Example 2 was treated with 40% peracetic acid to produce a poly-P-phenylenesulfone microfiber single fiber, and the poly-P-phenylenesulfone fiber was further treated with 30% peracetic acid.
% fuming sulfuric acid for 10 seconds to add a sulfonic acid group to the ester group. Next, the material was further treated with an aqueous solution of sodium hydroxide to convert the sulfonic acid group into sodium sulfonate.

Next, synthetic pulp mainly composed of Example 10 PMP I was mixed so that the former amounted to 45 wt% and the latter amounted to 55 wt%, and the mixture was treated in the same manner as in Example 2 to obtain a special sheet-like material. The 10 second paper was particularly good. Next, when a cationic coloring agent was partially applied to the special paper-like sheet using a screen method and coloring treatment was carried out, the resulting sheet was well colored and had high fastness. In other words, a paper was obtained which was highly heat resistant and could be colored satisfactorily. One special sheet material also had an ion exchange function.

Example 6 To the PPS of Example 1, 5 parts by weight of a diphenyl ether derivative in which two alkyl groups having about 15 carbon atoms were attached to diphenyl ether were added to 3100 parts by weight of PP.
The spinning temperature was 300°C. Spinning was carried out very smoothly despite the low temperature. Next, thread the yarn smoothly 3.
It was possible to stretch it up to 9 times. Hereafter, the same treatment as in Example 2 was carried out,
I got high quality paper. This paper had the same physical properties as Example 2, but was particularly excellent in radiation resistance.

Comparative Example 1 Only the island component of Example 1 was spun and treated in the same manner as in Example 1 to obtain a 3.5 d PPS single yarn.

This fiber was treated in the same manner as in Example 1 to form a paper-like sheet. However, the paper could not be made well, probably because the fibers were thick. The paper-like sheets that were partially produced were rough and hard, and moreover easily folded, so they could not be used in the same way as ordinary paper.

Comparative Example 2 The 3.5d PPS fiber of Comparative Example 1 and the commercially available 2d aromatic amide fiber manufactured by Kijin ■ under the trade name "Cornesox"
was cut into approximately 5 fi pieces, and prepared so that the former was 10 wt% and the latter was 90 wt%, and paper was made in the same manner as in Example 1.

However, the paper could not be made well, probably because the fibers were thick.

The partially formed paper-like sheet is rough and hard.

Moreover, it was easily foldable and could not be used like ordinary paper.

Comparative Example 3 The undrawn yarns of polymer array fibers made of PPS and polystyrene from Example 1 were tied together to form a tow.

Furthermore, it was cut to about 5 fi, and the sea component was removed with carbon tetrachloride. Next, a synthetic pulp mainly composed of PMP I manufactured by DuPont was prepared so that the content of Ryusha was 10 wt% and the latter was 90 wt%, and then treated in the same manner as in Example 1.
It was made into a paper-like sheet. Paper was made almost in the same manner as in Example 1.

Next, when we conducted a test in which the sheet was passed through a dryer at 315°C to heat-fuse the 9 synthetic pulp and ultrafine PAS short fibers, some of the PPS melted and fell off from the sheet, causing the sheet to lose its shape. Oops. Furthermore, the remaining undamaged sheets were brittle and easily torn.

Comparative Example 4 A synthetic pulp mainly consisting of the ultrafine unstretched cut PPS fiber of Comparative Example 3 and PMP I manufactured by DuPont was prepared so that the former was 50 wt% and the latter was 50 wt%, and the following was carried out. It was processed in the same manner as in Example 1 to form a paper-like sheet. There were no major problems in paper making. Next, the sheet is exposed to high temperature, and the PPS ultrafine fibers and PMP
In order to weld the synthetic pulp mainly composed of I, first 120
When the sheet was placed in high-temperature air at ℃, it shrunk significantly and moreover, it shrank unevenly, making it impossible to make a proper sheet. In addition, the sheet was placed in high-temperature air at 270° C. and the two were welded together, and the sheet was rough and hard to the touch, and was easily damaged when the sheet was folded several times.

Comparative Example 5 According to the method of Example 1 of Japanese Patent Publication No. 55-14163, isotactic polypropylene was dissolved in methylene dichloride, and the solution was further injected under high pressure to form a flocculent material. Furthermore, fibrillated isotactic polypropylene was obtained by beating. Next, it was used in Example 1. 3. A synthetic pulp mainly composed of PMP I manufactured by DuPont was used in the same manner as in Example 1. The mixture was mixed and paper-made to make a paper-like sheet. In this case, paper could be made well and good paper-like sheets could be produced. However, this sheet did not have heat resistance of 150°C. That is, it could not be used at all at high temperatures. Also, perhaps because the isotactic polypropylene was easily destroyed when exposed to radiation, the isotactic polypropylene easily fell off the paper-like sheet when rubbed.

Comparative Example 6 Sowt% of commercially available natural pulp, PM used in Example 1
Mixed with synthetic pulp mainly composed of PI.

Paper was made to make paper-like sheets. In this case, paper could be made well and good paper-like sheets could be produced. However, one sheet was not water resistant. It was also easily flammable.

〔Effect of the invention〕

By adopting the configuration of the present invention, the following great effects are brought about.

■Special paper-like sheets with extremely high heat resistance can be obtained.

■Produces special paper-like sheets with extremely high water resistance.

■Produces special paper-like sheets with extremely high chemical resistance.

(2) In particular, paper-like sheets made of wholly aromatic polyamide, polyimide, polyaramid, PBT, PBO, etc., and PPS, etc. have extremely high flame retardance. Also.

Such a paper-like sheet has all the above characteristics.

(2) Particularly, paper-like sheets having a structure in which an aromatic ring polymer and PAS fibers such as PPS are adhered (welded) have very little falling off from the sheet. In addition, it has all of the characteristics of ■ to ■, and if an aromatic ring-containing polymer is specified, it also has the characteristic of ■.

(2) In particular, when PAS fibers with acidic groups such as sulfonic acid groups added to aryl groups are used to form special paper-like sheets, they can be easily colored with cationic colorants and are difficult to fall off.

■Especially when a heat-resistant material is used as a sizing agent.

Special paper-like sheets have extremely high heat resistance.

■In particular, when PAS fibers with acidic groups such as sulfonic acid groups added to aryl groups are used, a special paper-like sheet with ion exchange function can be obtained, and its own heat resistance, hot water resistance, and chemical resistance. Because it is extremely expensive, the use of ion exchange paper has spread rapidly.

■In particular, if PAS fibers containing diphenyl ether derivatives are used, sheets with extremely high radiation resistance can be obtained.

Claims (2)

[Claims] (1) A special paper-like sheet, which comprises at least [1] fibers made of an aromatic ring polymer and [2] polyarylene of the following structural formula that is 0.3 denier or less and mainly consists of short fibers. A special paper-like sheet characterized by containing fiber. ▲There are mathematical formulas, chemical formulas, tables, etc.▼x=0~2 (2) The special paper sheet according to claim 1, wherein the aromatic ring-containing polymer is poly-phenylene-phthalamide, polybenzobisoxazole, or polybenzobisthiazole.