JPS58163722A - Production of flame-retardant polyamide fiber or film - Google Patents

Abstract

PURPOSE:An optically anisotropic dope containing a phosphorus-containing compound as a solvent component is subjected to wet forming to give the titled fiber or film with high mechanical properties. CONSTITUTION:Sulfuric acid of higher than 90wt% concentration, phosphorus pentoxide in an amount of 0.1-0.6 mole per mole of the water included in the sulfuric acid and a polyamide cited below are used to prepare an optically anisotropic dope and the dope is subjected to wet forming into fiber or film. The polyamide is composed of reccurring units selected from the groups consisting of formulasI, II and III (the units represented by formulaIand formula II exists in equinolar amounts, when they present in the polymer; R, R' and R'' are divalent radical; n is 0, 1; more than 95mol% of R, R' and R'' are one hard group bearing a extending chain bond or 2 or more hard groups bonding one another through extending chain bonds directly or containing azo or azoxy groups as bridges).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing polyamide fiber or film OIl which has excellent mechanical properties and is difficult to manufacture. This relates to a method for obtaining a polyamide fiber X-ray film with excellent mechanical properties and difficulty from an optically anisotropic dope. For this reason, it has been attracting attention in recent years, but the solubility of aromatic polyamides with polymeric properties is extremely poor, and the only known solvent system is Minato sulfuric acid or its similar compounds. do not have. For example, @! 5s
No. 14170 discloses that at least 98×11 degrees of sulfuric acid and chlorosulfuric acid, fluorosulfuric acid and mixtures of these acids are prepared by a certain company as required. These acids include hydrofluoric acid,
halogenated alkyl sulfones, halogenated aromatic sulfonic acids, halogenated acetic acids, halogenated lower alkyl alcohols and halogenated nine-keto, y- or aldehydes,
Using a mixture containing trifluoromethanesulfonic acid, sulfone, chlorinated phenol, and nitrobenzene as additives in an amount of about 30×1 of the total weight of the solvent and additives, optically anisotropic polyamide is produced from this and a para-oriented aromatic polyamide. After preparing the dope, fibers or films with excellent mechanical properties are obtained from the dope. The patent publication Kti does not mention anything about the flame retardancy of the nine-fiber film obtained from the sulfuric acid dope by this method. Since the polyamide fiber or film disclosed in the Scissor Patent Publication is self-extinguishing, it seems that no consideration was generally given to improving flame retardancy.

The present inventors have discovered the fiber X of Japanese Patent Publication No. 55-14170
In the process of researching flame retardancy for wire films, we unexpectedly discovered that it was effective to contain a special amount of a dope (R41) type compound and wet-forming it. Furthermore, in systems containing such 〉-based compounds, it has been conventionally believed that a low degree of 70II is unfavorable for rounding due to insufficient solvent power, and even if less than 998% by weight of sulfuric acid is used, it is still It was also discovered that an optically anisotropic dope can be formed, and the present invention was achieved by forming a round O, that is,
In the present @O method line, units of the following formula (wherein the units I and l are present in substantially molar amounts when present in the heavy metal body, the groups R11' and R
1 may be the same or different, and represents a divalent group,
The grave is O or the integer 1, and all groups a18' in the polymer
and at least about 95 mo of Ro.

% consists of one hard group with a dielectric chain linkage or a series of such hard groups linked directly through an X-ray azo or azoxy group by a chain linkage. ) to produce a flame-retardant polyamide fiber or film consisting of a polyamide consisting essentially of repeating units selected from the group consisting of fil), 90% by weight or more and less than 0% by weight. An optically anisotropic dope is prepared from 0.1 to 0.6 mol of dinidine pentoxide and the above polyamide per 1 mol of water contained in the composition, and the cough dope is wet-processed. This is a method for producing a film made of flame retardant polyamide fibers.

The polyamides of the fibers and films produced by the process of the present invention are composed of groups of the following formula (wherein unit I and the ring are present in substantially 5 equivalent molar amounts when present in the polymer). However, the groups R18' and R@ may be the same or different and represent a divalent group, and n
is O or an integer, and at least about 95 mole % of all groups R' and R1 in the polymer are directly bonded to each other by one rigid group or chain bonds. From a series of such hard groups, a series of carefully selected repeating units consisting of 0) can be used. Thus, a substantial portion of the polymer is l
1ii! gives a chain (polyoxy-1# when n is O)
According to the method of the present invention, copolya zeta units (i.e., 8 or R
' is a mixture of at least two different groups, or if units I, l and I are present), as-spun fibers and films with an elongation of at least 4.5 have a degree.

On the other hand, the product of the present invention made from a polymeric boric acid having an elongation of at least 3.5X, herein the term "hard i group" refers to (a) a cyclic group; - (2, 2,
2)-bicyclooctylene, and 佽) linear unsaturated group:
Means vinylene-CH=CH- and ethynylene-C=C-. It must be understood that monomers containing amino groups directly bonded to linear unsaturated groups are not stable and therefore cannot be useful with vinylene or ethini.

The term "extending bond" refers to bonds that extend the molecular chains of groups that are substantially coaxial (as in hytrans-1,4-cyclohexalene) and oriented in opposite directions. (Whether or not it is sharpened is determined by actually measuring the bond angle). When these polymer structures are further mixed with some strong protic acid solvents,
It has the characteristic of forming an anisotropic X-ray liquid crystalline phase.

This will be explained in detail later.

Suitable groups with extended chain bonds, which are suitable as R, R' and R1, are trans-1,4-cyclohequin-vinylene, ethenylene, azo or ay+cy linked by 91,4-phenylene groups. be. Additionally, Ra) can also serve as the radical R1 for trans-vinylene, ethynylene, trans, trans-1,4-butadienylene.

8. R' and R'a may be substituted and/or unsubstituted groups; 10. Substituent groups, if present, preferably during subsequent processing of the polymer (such as during heat treatment of its molded article); It should be non-reactive (eg thermally stable). The reactivity of the substituents is undesirable in that it causes branching and crosslinking of the polymer and adversely affects the properties of the dope and/or X-ray fibers. Preferred non-reactive substituents include d, halogen (eg chloro, boom and fluor), lower alkyl (eg methyl, ethyl and isopropyl), methoxy, cyano and nitro groups. In general, it is preferred that two (more preferably one bulk) suitable substituents be present per single group. More preferably, the groups R, R' and R10 in the polymer
No more than 20 mole % should be substituted with 9r.

Preferred types of heavy metal bodies of the group mentioned above are those in which R and R′ are groups 1
．． 4-phenylene, 4.4'-biphenylene, 2.6-
naphthylene, 1.5-+7 tyrene, and trans-1.
selected from 4-cyclohexylene and 2R is further a group 2,5
-pyridylene and trans-vinylene: R
1 is 1,4-phenylene; and at least 50 mole % of the total of R and R' is completely aromatic. The most preferred among the suitable polymers of keratin seeds are those in which R is a group 1,4-7 dynylene, 4.4'
- biphenylene, 2,6-naphthylene, 2,5-pyridylene, trans-1,4-cyclohexylene, and trans-vinylene, where R' is trans-1,4
-cyclohexylene, 1,4-phenylene, and 1.4
- selected from a mixture of phenylene and up to 50 mol % 04,4'-biphenylene = R1 is 1,4-phenylene; and (I) at least 75% of the total of R and R'
The polymer satisfies the following conditions: mol % is completely aromatic, and at least 75 mol % of either R or R' is 1,4-7 enylene.

The lance-shaped chain of the present invention does not correspond to the foregoing description.
Groups, such as groups without extended chain bonds or non-rigid groups, may be included at about SN (molar basis).

It should be understood that groups that do not comply with these conditions will have different effects on the properties of the as-spun product. That is, hard groups such as m-7 enylene, in which the bonds extending the chain are neither coaxial nor parallel and opposite, and very soft groups such as hex, t-methylene, and decamethylene, are usually present in small amounts. used in 4.4′-
Groups such as bipendylene, even when used in amounts greater than 5X, produce fibers that still exhibit the unusual combination of properties of the products of this invention. The gold portion of the amide unit in the linear condensation polymer chain, although not preferred,
If desired, other stable non-acade-forming units may be substituted, such as ester-forming units or urea- or sulfonamide-forming units. Generally, such products are more difficult to manufacture and have very limited uses.

The polymer to be spun may be a homopolymer, a random copolymer, an ordered copolymer or a mixture of homopolymers and/or copolymers. The fibers and fillers of the present invention may also contain conventional additives such as dyes, fillers, brighteners, UV stabilizers, antioxidants, etc.゛Suitable polyamides include poly(p-7enylene 7taland); poly9(pyenylene p, p'-biphenyldicarpoxamide); poly(p-phenylene 1.5
Poly(trans, trans-4,4'-dodecahydrobiphenylene 7-talua); Poly(trans-1,-1 cinnamide); Poly(p-phenylene 4); Poly(1,4-(2,2,2)-bicyclooctylenetere7talua()''); Copoly(P-phenylene 4゜4/-azoxy Benzenedicarpoquinamide/
terephthalamide); poly(p-7 enylene 4.4'-
) and poly(p-phenylene acetylene carbokinamide).

The S medium used in the present invention has a lo content of 90% by weight or more.

The preferred Ktt should be less than 94 wt. Solvent Q of the present invention - The amount of water contained in the sulfuric acid, i.e., the mole number of water, depends on the content of dinidine pentoxide used as the acid component, and its ratio is LO: PtOs = 1:
A (Here, M is 0.1≦A≦'0.8) O゛ is selected. The reason for choosing this range is as follows. In other words, when the humidity is 0.1, the flame resistance of the resulting fiber or film after wet aging should not be improved; It was mixed! This is not preferred because the decomposition reaction of sulfuric acid is too slow, or the polyamide tends to deteriorate and the intrinsic viscosity decreases. The value of
-0.35.

The sulfuric acid containing 90% by weight or more and less than 100% by weight x is recycled as follows. 90% by weight sulfuric acid no longer sufficiently dissolves the polyamide used in the present invention, and 100% by weight or more sulfuric acid does not dissolve the P to be added.
This is because the amount of Ps has to be reduced, making it impossible to achieve the initial objective of improving flame resistance. (preferably from 94 to 99*% by weight), it is then possible to provide fibers and films that have good mechanical properties and are sufficiently difficult to process, which are the effects of the present invention.

The polyamide used in the present invention has extremely poor solubility. For that purpose, for example, ~Fan Gong Kei '51-[4170 Bulletin] lists sulfuric acid with a concentration of at least 98%, and chlorosulfuric acid, fluorosulfuric acid, and substantially from these acids as suitable solvents for boric acid. It is also stated that the moisture content of the dope should be carefully adjusted to be less than 2%. As mentioned above, the method according to the present invention allows the use of sulfuric acid with a concentration far below 98% by weight, but if the concentration of sulfuric acid is 90% by weight or more, the amount of P! By using o- in combination, a dope useful for item 11 can be obtained without causing excessive deterioration of the polyamide or interfering with the production of a dope suitable for spinning.

In the present invention, it is important to use an optically anisotropic dope. Here, whether or not the dope has optical anisotropy can be determined, for example, in Tokukai Publication No. 8474/1983, in a rounded manner. The fact that DOG has optical anisotropy is considered to correspond to the fact that it forms a liquid crystal.

The reason why optically anisotropic doping should be used in the present invention should be understood as follows. In other words, it is difficult to think that the fact that the dope has optical anisotropy itself is directly related to the superior mechanical properties of the molded product (fiber or film); rather, the high boria 2 of the dope
It should be considered that such a high boria 2 do concentration produces optical anisotropy in the doped state and excellent mechanical properties in the molded product. Therefore, the optical anisotropy is superimposed as an indicator of a useful surrogate characteristic of high polyamide concentration. Range of polyamide concentration showing optical anisotropy, degree of polymerization of polyamide (
intrinsic viscosity), dope temperature, sulfuric acid concentration, P! Although it may vary slightly depending on the amount added to the can, it is approximately 10% by weight or more, as will be explained in detail later.

The intrinsic viscosity of the polyamide used in the present invention is not particularly limited, but is usually set to a constant value of 10 or more to 10.0 by the method described below.
Suitable insects are as follows, preferably 3.0 or more and 7.0 or less. The polyamide concentration of the round iron dope may be as long as it forms an optically anisotropic dope.
sulfuric acid, P, 05, and polyamide), preferably from about 10% to 25% by weight, preferably 14%
A range of % by weight or more and 20% by weight or less is appropriate. Boriaod fibers and films made of a wet acid part of a nine dope having an intrinsic viscosity and a concentration substantially of that of these polyamides have properties of high tenacity and high density, in addition to difficult properties. - In the method of the present invention, the timing of addition of P-Os may be at the time of dissolving the boria 2, and the polyamide is mixed with sulfuric acid,
There is a method of adding PtOs after swelling or swelling, or a method of adding PtOs to sulfuric acid in advance! A method of adding scissors polyamide after dissolving 0@ is used. In response to the dissolution of polyamides in the above-mentioned solvents, the company uses hydrogen fluoride, hydrogen chloride, fluorosulfuric acid, cool sulfuric acid, antimony trifluoride, antimony trifluoride, boron trifluoride, and trifluoride as dissolution aids. It is also possible to use one or more of the following.

The fibers or films of the present invention may be blended with known compounding agents such as antioxidants, heat stabilizers, ultraviolet absorbers, colorants, flame retardants, and matting agents according to formulations known per se.

For the production of fibers, a round technique similar to the conventional wet spinning method can be used.
After passing through an oriice, the fibers are passed directly into a coagulating medium, or after passing through a non-coagulating medium such as air, they are extruded into a coagulating medium and solidified into fibers in the coagulating medium. Hydrous water is preferably used as the coagulation medium, but monohydric or polyhydric alcohols such as methyl alcohol, ethylene glycol, glycerin, isoptetrapanol, mixtures of water and the above alcohols, acids such as sulfuric acid, etc. Alkali such as ammonium hydroxide and various salts such as Schiff's 5 are used for chlorination. During this wet spinning, the temperature of the dope or coagulation medium is expressed as 1lIK'flA@, but generally -
10-10CjC (D range @IIc is desirable.

In a preferred embodiment of the invention, the cough dope is spun into a non-rigid atmosphere and the spun fiber stream is then solidified into fibers in a coagulation medium. At this time, the coagulation medium is
Preferably, the fibers are formed by a spot-down tension spinning process in which the fiber stream is caused to flow downward in the spinning direction and tension is applied to the fiber stream by friction created between the coagulation medium and the fiber stream. As the non-solidifying medium, a gas such as air or nitrogen or a liquid immiscible with the dope such as a hydrocarbon liquid is used, and as the solidifying medium, those mentioned above are used.

The nine fibers, which are spun and wound at a suitable speed, are passed through a washing liquid such as water or ammonium chloride, and then dried in air at 90 to 150° C. for a suitable period of time. Depending on the case, heat treatment at a moderate temperature can also be performed.

Films can also be formed by the same method as fibers.

The material obtained by the method according to the present invention has excellent fire resistance.1. S flammability -1 For example, even if placed in the flame of an alcohol lamp, it will not burn or emit carbonization, and has a high LOI.
value (extreme oxygen index).

The present inventors are still unable to ascertain the exact reason why the flame resistance of the molded product of the present invention is improved. surely,
The fibers and films obtained by the method of the present invention tend to have a higher P content than the fibers and films obtained by the conventional method. However, the difference in level is 10'-10'' ppm, and the fibers and films obtained by the method of the present invention have improved flame resistance even when the P content is slightly low. Or perhaps some difference in the microstructure of the adult material is at play.

The fibers according to the invention have excellent flame retardancy, excellent initial modulus and high strength, 41 high tensile strength and knot strength, loop strength and heat resistance, weather resistance and UV resistance. In addition, these characteristics have many industrial uses, such as tire cords, rubber belts, reinforcements for rubber products such as hoses, fiber reinforcements for various rice fiber reinforced plastics, or ropes, furnace cloths, etc. It is useful for industrial fibers such as various covers and clothing fibers such as sewing thread.

The film according to the present invention has excellent flammability, high strength, and initial modulus, making it suitable for electrical insulating films, magnetic tape (computer tape,
It is suitably used for video tapes, cassette tapes, etc., microphone haze films, movie films, transparent films, wrapping strings, etc.

Hereinafter, the present invention will be explained in detail by giving examples and comparative examples thereto. wing

tTh, JIB 7201, which is commonly used as an index of the drying properties of polyamide molded products, is used to measure the ultimate oxygen index (L (D=I=)).

The intrinsic viscosity (dink) is expressed by the following formula.

v ink = zn (vr) / C In the above formula, C is the concentration of the heavy body** (#medium 1GOsd polymer or textile or film 01F)〉, wr (relative viscosity) company,
Measured at 35° C. in a capillary viscosity tube and determined by dividing the flow time of Kokonoe Taitotan by the flow time of pure solvent. In this case, sulfur (118 to 98% by weight) was used as the solvent. (abbreviated) K is shown,
The OIK embodiment of the present invention and its effects are limited to the examples.

Example 1 97.5 wt% Ht 80427009 (containing 3.75 moles of water) to Pros 1429 (1 mole)
After dissolving PPTA (Winh=4.4) 593
9 was added and melted at 70 to 75°C to obtain a shiny optically anisotropic dope in about 1.5 hours. Solution viscosity Fi27
00 poise (71°C). The whole was transferred to a spinning device kept at 75°C, and after degassing under vacuum for about 2 hours, it was passed through a conduit with a built-in filter using a gear pump.
The material was introduced into a 50-hole spinneret, passed through an air layer in the air chamber, extruded vertically into water at 3°C, and rolled up into a bottle under draft. - After washing by immersion in running water at night, dry at 100°C for 2 hours to obtain yarn (η1nh=4,2).

Further, 8.8 g of the defoamed dope was stretched to a thickness of Q and 05 cm on a glass plate kept at 75°C.

- After washing by immersion in running water at night, it was dried at 100°C for 2 hours to obtain a film (Wink=41).

Results II! Show IK.

Table 1 Comparative Example 1 97, s wt% H280a 2700 fl PPT
Add A (Da1nk=44) 5939 and heat to 70-75℃
The fiber was obtained using the same spinning equipment and spinning conditions as in Example 1. (Wink=40) and film (vinh=4.1
) physical properties are shown in *2.

Table 2 The method of Comparative Example 1 outside the present invention has operational disadvantages such as slow dissolution of the polyamide and difficulty in spinning due to the high viscosity of a certain percentage of Ali dope (poor spinnability). , the decrease in the intrinsic viscosity of PPTA was somewhat large, and 7? The rounded fibers are rather small and 90% round, and what is more important is that the LOI value is low overall. Therefore, the properties of the fibers and film of Example 1 produced by the method of the present invention are clearly superior to those of the fibers and film of Comparative Example 1 produced by a method other than the present invention.

Comparative Example 2 99.5% by weight Hw No. 80 28G (PPTA (
η1nh=4.4) Add 61SIF and heat to 70-75℃
After about 2 hours, a shiny optically anisotropic dope was obtained. The solution viscosity was 2810 boids (71"C) and 690 fibers (Win) obtained by wet forming in the same manner as in Example 1.
Table 3 shows the physical properties of the film (q inh = 4.2) and the film (q inh = 4.2).

Table 3 The LOI values of Comparative Examples 1 and 2 are 29 to 31, which is 90% lower than the LOI value of 31 to 35 in Example 1. Example 2 95.2% by weight HzSO+ 27502 (containing 7.33 moles of water) was added with P*0*3419 (2, 40
After dissolving PPTA (vimh=15) 3419
was added and melted at 70 to 75°C to obtain a shiny optically anisotropic dope in about 2 hours. Solution viscosity a4100po4A
C71°C). Nine fibers (lFinh=5.3) and a film (η1
Table 4 shows the physical properties of nh=5.2).

Table 4 Example 3 93.0 weight XH180427309 (including;
0,61 mol) K, Prom S 029 (3
, 54 mol) was dissolved, then PPTA (Wink = 4.4 mol) was dissolved.
) 6559 and melt at 75-110℃, about 2
．． A glossy optically anisotropic dope was obtained in 5 hours.90 The solution viscosity was 5200 poise (71"C) and 11119 fibers (Winh=
4.3) and physical properties of the film (wink=4.3) Table 5
Shown below.

Table 5 Procedural amendment December 22, 1932 Mr. Kazuo Wakasugi, Commissioner of the Patent Office 1 Display of incident % Gusho 57-4027.2.

2. Name of the invention: Method for producing flame-retardant polyamide fibers or films 5. Relationship with the amended case/Patent applicant (oos): Asahi Kasei Corporation.

4 Agent, Toranomon Sangyo I, 5th floor, 2-29 Toranomon-chome, Minato-ku, Tokyo, 5th floor, 5th floor, 5th floor, Toranomon Sangyo I, Claims column I of the specification to be amended, Detailed description of the invention column 6, Description of the contents of the amendment. The following corrections will be made.

(1) The statement of the claims shall be amended as follows.

"Units of the following formula (in the above formula, units I and II are present in substantially equimolar amounts when present in the polymer, and the groups R1R' and RI
' may be the same or different and represents a divalent group,
n#io or the integer 1, and at least about 95 moles of the total groups R, R' and R' in the polymer have one hard group or chain linkages directly or azo or azoxy to each other by chain linkages. Consists of two or more hard groups bonded via a group. ) for producing flame retardant polyamide fibers or films consisting essentially of repeating units selected from the group consisting of: 90% by weight - 10%
Sulfuric acid at a concentration of less than 0% by weight, water contained in the sulfuric acid 1
Optically anisotropic dope'ft from diphosphorous pentoxide and polyamide in an amount of 0.1 mol or more and 6 mol or less per mole
A method for producing a flame-retardant polyamide fiber or film, characterized by wet molding the dope. ” (2) Page 5, line 14

Claims (1)

[Scope of Claims] Units of the following formula (in the above formula, the units ! and l are present in substantial molar amounts when present in the polymer; the groups R1R' and R
1 may be the same or different and represents a divalent group,
n FiG or an integer of 1, at least about 95% of the total number of groups R, R' and R'' in the polymer is one hard group having an extended chain bond or an extended chain. It consists of two or more hard groups connected to each other by bonds, either directly or through an azo or azoxy group. ) to produce flame retardant polyamide fibers or films consisting essentially of repeating units selected from the group consisting of 90% by weight
At least 100% by weight of plain sulfuric acid, 0.1 to 0.6 mol of diphosphorus pentoxide per 1 mol of water contained in the sulfuric acid, and an optically anisotropic dope from the above-mentioned boriad. 1. A method for producing a flame-retardant polyacrylic fiber film, which comprises preparing a flame-retardant polyamide fiber film and hot-layering it with a dope. −