JPS62131026A - Production of fully aromatic polyamide molding with hydrophobic surface - Google Patents

Abstract

PURPOSE:To obtain the titled molding excellent in strength, modulus, heat resistance, tear resistance and dimensional stability, by rendering only the surface hydrophobic by reacting a specified fully aromatic polyamide molding by heating with a halogen compound, an ester, etc. CONSTITUTION:A molding, such as fiber, woven fabric or film, obtained by molding a fully aromatic polyamide repeating units of formula I and/or formula II (wherein Ar1-3 are each a bivalent aromatic group) is reacted with a halogen compound (e.g., methyl iodide), a heterocyclic compound (e.g., propylene oxide), an ester compound (e.g., mesyloxybutane), an alcohol, an organic acid (e.g., acetic acid) or a Michael acceptor (e.g., styrene) in the presence of, optionally, a base, an acid or the like at 50-300 deg.C for 1sec-3hr to render the surface hydrophobic by converting part or all of the amide bonds on its surface into N- or O-substituted derivatives.

Description

Detailed Description of the Invention [Technical Field of Application of the Invention] The present invention is a method for producing a wholly aromatic polyamide molded article with surface hydrophobicity, and more specifically, a method for manufacturing a wholly aromatic polyamide molded article without damaging the wholly aromatic polyamide molded article. The present invention relates to a method for producing a wholly aromatic polyamide molded article in which only the surface is made hydrophobic.

[Prior art]

As a heat-resistant polymer, molded products such as fibers and films made of so-called fully aromatic polyamides, in which all of the divalent hydrocarbon groups bonded through amide bonds are aromatic cyclic groups, have high strength and high strength. It is useful in a variety of applications because of its elastic modulus and excellent heat resistance. In particular, because of its high strength and high modulus properties, galvanizing fibers are added to various thermoplastic resins, rubbers, and thermosetting resins as reinforcing fibers, and are used to improve the mechanical properties, heat resistance, etc. of the compositions. is being considered.

For example, Polymer Engineering and Science Vol. 14, p. 633 (1974), Journal Opazolide Polymer Science, Vol. 20, p. 435 (1976),
Rano-Chemistry and Technology Volume 50 9
(See p. 45 (1977)) [Problems to be solved by the invention] However, fully aromatic polyamides generally have large moisture absorption and resulting dimensional changes due to the hydrogen bonds between the amide groups of the polyamide. Group polyamide films have a 10
The hygroscopic expansion rate is more than twice as high.

Journal of Polymer Science, Polymer Chemistry Edition, Vol. 19, p. 1133 (1981) discloses a technique for substituting fully aromatic polyamide with N-alkyl in dimethyl sulfoxide, which reduces moisture absorption, Alternatively, an improvement in moisture absorption stability can be expected, but in reality, the surface of a wholly aromatic polyamide molded product is an intermediate of this method, such as N-metalized wholly aromatic polyamide and N-alkylated wholly aromatic polyamide. When modified, these chemicals have poor chemical resistance, which can damage the surface of the molded product or destroy a dense layer if it exists on the surface, resulting in a decrease in moisture absorption and moisture absorption. It turns out that sexual improvement does not materialize. In addition, heat treatment of wholly aromatic polyamides is disclosed in Japanese Patent Application Laid-Open No. 47-43419, etc., and it is thought that this increases crystallinity and improves moisture absorption properties accordingly, but the degree of There are also drawbacks such as the fact that the fully aromatic polyamide is extremely small and brittle.

[Means to solve the problem]

As a result of intensive research in order to solve the above-mentioned problems, the present inventors have discovered that halogen compounds, heterocyclic compounds, ester compounds, alcohols, organic acids, or michaelyl compounds are added to the surface of fully aromatic polyamide molded products. We have found a solution to this problem and have arrived at the present invention.

That is, the present invention has the general formula -NH-A r H-NH-CO-A r2-C
A wholly aromatic polyamide molded product having a repeating unit of halogen compounds,
By reacting with a heterocyclic compound, an ester compound, an alcohol, an organic acid, or a Michael acceptor, some or all of the amide bonds on the surface of the theramide molded product are converted to N.
This is a method for producing a surface-hydrophobic wholly aromatic polyamide molded article, characterized in that it is a 1- or 0-substituted derivative.

In the wholly aromatic polyamide used in the present invention, at least 85 moles of amide bonds are obtained from aromatic cyclic diamine and aromatic cyclic dicarboxylic acid components. Examples of its structures include polyno ξ lapenzamide, polyno zo raphenylene tele 7 thalamide, poly-4,4'-diaminobenzanilide terephthalamide, polyparaphenylene-2,6-natalic amide, and cobolino graph ene 7/4.4'(3,3'-dimethylbiphenylene)-terephthalamide, copolyparaphenylene/2,5-hyridylene-terephthalamide, polyornephenylenephthalamide, polymetaphenylene phthalamide, polymetaphenylene phthalamide, polyorthophenylene isophthalamide amide, polymetaphenylene terephthalamide, polyparaphenylene isophthalamide, polyornophenylene terephthalamide, polymetaphenylene terephthalamide, ;tx)-1,5-naphthalene phthalamide,
poly-4,41-diphenylene-ortho-7-talamide, poly-IJ-4,4'-diphenylene-iso-7-talamide,
Poly-1,4-naphthalene phthalamide, poly-1゜4
- Naphthalene isophthalamide, poly-1,5-naphthalene isophthalamide, etc., and compounds in which part of the benzene nucleus of these aromatic diamines is substituted with halokene, (
Aromatic polyamides containing alicyclic amines, such as compounds in which part of the benzene nucleus of these aromatic diamines is replaced with piperazine, 2.5-dimethyl-radine, 2.5-diethylpiperazine, etc. Aromatic diamine is 3.
Ether groups such as 3'-oxy, diphenylene diamine, 3.4'-oxydiphenylene diamine, alkyl groups,
-Aromatic polyamides containing two phenyl groups linked by groups such as -s-, -so□-, -C-, -NH-, or -copolymers of the aromatic polyamides mentioned above, such as PoIJ-3 Examples include 3'-oxydiphenylene terephthalamide/4+) nosorough phenylene terephthalamide copolymer, poly-3,4'-oxydiphenylene terephthalamide/polynosorough phenylene terephthalamide copolymer, etc. can.

The wholly aromatic polyamide used in the present invention may be in the form of citron birch, and is not limited in any way, and includes, for example, spray pA (multifilament, staple, chopped strand, monofilament), fibrid, film, Examples include woven fabrics, nonwoven fabrics, sheets, paper, and powders, with fibers, films, and woven fabrics being particularly preferred.

The method for manufacturing these molded products from fully aromatic polyamide is as follows:
There are no particular limitations in implementing the present invention.

The halogen compounds used in the present invention include methyl iodide, ethyl iodide, propyl iodide, octyl iodide, stearyl iodide, ethyl bromide propyl bromide, octyl bromide, stearyl bromide, benzyl bromide, and chloride. ethyl,
Examples of the heterocyclic compound include propyl chloride, octyl chloride, stearyl chloride, benzoyl chloride, etc.; examples of the heterocyclic compound include propylene oxide, N-methylaziridine, N-benzylua syridine, N-methylazetidine, etc.; Examples of the alcohol include mesyloxyzolonozone, mesyloxybutane, tosyloxypropane, tosyloxybutane, tosyloxyoctyl, tosyloxystearyl, tosyloxybenzyl, etc. Alcohols include methanol, ethanol, octatool, 1,1. Examples of organic acids include acetic acid, zoropionic acid, octanoic acid, stearic acid, benzoic acid, etc. Michael acceptors include styrene, acrylic esters, methacrylic esters, acrolein, methacrolein, acrylamide,
Examples thereof include methacrylic acid amide, acrylonitrile, methacrylonitrile, etc., and particularly preferred are trifluoroethyl methacrylate and dimethacrylic acid to increase hydrophobicity.
．． 2.3.3-Tetrafluoropropyl, methacrylic acid 2
．． Examples include unsaturated ester compounds having a fluorine atom in the ester group, such as 2.3.4°4.4-hexafluorobutyl, fluorooctylethyl methacrylate, and perfluorooctylethyl acrylate.

In the present invention, it is preferable not to use a solvent in the treatment in which a wholly aromatic polyamide molded article is reacted with a halogen compound, a heterocyclic compound, an ester compound, an alcohol, an organic acid, and a Michael acceptor under heating. It is also possible to use organic solvents such as ether, methylene chloride, etc.

In the present invention, in the treatment in which a wholly aromatic polyamide molded article is reacted with a halogen compound, a heterocyclic compound, an ester compound, an alcohol, an organic acid, or a Michael acceptor under heating, the equilibrium of the nola reaction is In order to smoothly transfer to ) can coexist, and this is even more preferable.

The halogen compounds, heterocyclic compounds, ester compounds, alcohols, organic acids, and Michael acceptors used in the present invention are preferably used after pretreatment such as purification and dehydration, if necessary, so that they do not inhibit the reaction. It is also possible to have other solvents present.

In the treatment of reacting a wholly aromatic polyamide molded article with a halogen compound, a heterocyclic compound, an ester compound, an alcohol, an organic acid, or a Michael acceptor under heating, there are no particular restrictions on the reaction temperature and time; The reaction temperature is preferably between 50°C and 300°C, particularly preferably between 100°C and 250°C, and the reaction time is suitably between about 1 second and about 3 hours.

Regarding the reaction temperature, when the boiling point of the halogen compound, heterogeneous compound, ester compound, alcohol, organic acid, or Michael acceptor used is 100° C. or lower, it is more preferable to carry out the reaction in an autoclave.

Furthermore, there is no particular restriction on the degree of a of this reaction, and a method that does not use a solvent is preferred.

It is believed that by the method of the present invention, part or all of the surface layer of the wholly aromatic polyamide undergoes an N- or O-substitution reaction, and the N- or O-substituents on the surface of the wholly aromatic polyamide are red. It can be detected by methods such as external absorption spectroscopy, ATR method, chemical analytical electron spectroscopy (ESCA), and water contact angle measurement.

〔Effect of the invention〕

The feature of the surface-hydrophobic wholly aromatic polyamide molded article of the present invention is that the hygroscopic coefficient and hygroscopic expansion coefficient are reduced by substituting the N-position or 0-position of the amide group on the surface with a hydrophobic group. This is because the hydrogen bonds of the amide groups of the fully aromatic polyamide molded product on the surface are destroyed by the N- or O-substitution reaction, and the hydrophobic groups are spread across the surface.

The conventionally known method for introducing an N-substituent into a polyamide group is to first introduce N-gold! In order to prepare the A salt and react it with the hydrophilic agent, there was a great deal of trouble in removing water and in the troublesome operating procedures.However, in the present invention, the reaction can be carried out in one step by carrying out the reaction under heating. Since the N- or 0-F4' exchangeable barrel can be introduced onto the polyamide surface using only a single step, the operation is extremely simple and the reaction can be carried out cleanly. In addition, the invention has the feature that it can be processed without damaging the surface, so it has the characteristics of fully aromatic polyamide molded products, such as high strength, high modulus, heat resistance, high tear resistance, and dimensional stability at high temperatures. Hydrophobicity can be achieved without sacrificing much of the properties.

〔Example〕

Hereinafter, in order to further clarify the present invention, the present invention will be explained using actual winding examples, but it goes without saying that the scope of the present invention is not limited to these examples.

In the examples, the hygroscopic expansion coefficient is 10% when the sample is
After drying completely at 0° C. and cooling to room temperature, the elongation was measured using a TMA (thermal stress strain measuring device) in an atmosphere with a relative humidity of 90 coefficients, and the elongation was calculated using the following formula.

Example 1 In a 50 ml eggplant-shaped flask, 1 ml of benzyl bromide and the amount of catalyst (approximately 5 mg) were placed in a 2 cm x 2
A poly(p-phenylene terephthalamide) film (according to the method described in Japanese Patent Publication No. 17886/1986) was added, and the mixture was reacted for 20 minutes at 150° C. in a silicone oil gas. After the reaction, it was washed with acetone and air-dried. The hygroscopic expansion coefficient of the poly(p-722/terephthalamide) film treated in this way is 4.1xio''''''/w
4 RH and that of the unprocessed film (6,OX
10-""/mm+%RH), the shrinkage due to moisture absorption could be suppressed to about one-third.

Example 2 Methacrylic acid 2,2 was added to a 50+11 eggplant-shaped flask.
゜3.3 Tetrafluorozolovir I Ne and 2m x 2cr
n poly(p-phenylene terephthalamide) film (according to the method of Japanese Patent Publication No. 57-17886), and
/I): Reacted for 10 minutes at 180°C in 17 oil A bath. After the reaction, it was washed with acetone and air-dried. The poly(p-phenylene terephthalamide) film treated in this way has a wet expansion coefficient of 1. OX 10-'C4
1 (11, that of unprocessed film (6,0X1
Compared to the 0zu fin/'rRr4R (branch), dimensional changes due to moisture absorption can be suppressed to about one-sixth.

1 no-, sil (t/Ii 3 methacrylic acid 2.2.3.3-son trafluoroprovir l
Example 2 was repeated, except that instead of 1 ml of trifluoroethanol, 1 ytl of concentrated sulfur and 1 d of concentrated sulfur were used.

Films processed in this way are
i-%R1 (and that of the untreated film (S,
Compared to OXl 0-''/Jr%RH), the dimensional change due to moisture absorption could be suppressed to about two-thirds.

Example 4 Poly(p-phenylene terephthalamide) #fiber (
Example 1 was repeated except that 500 mg (thread diameter: 12 μm) was used. In this case, treated and denatured po'J (p
-phenylene terephthalamide) The moisture absorption rate of the fibers is 24
The hygroscopicity was about half lower than that of untreated fiber (5,096).

Example 5 Example 1 except that 500 mg of woven fabric (average of 110 threads with a diameter of 12.1 μm) of poly(p-)unilene terephthalamide) fibers was used instead of the poly(p-phenylene terephthalamide) film. repeated. In this case, the hygroscopicity of the woven fabric of treated and modified poly(p-phenylene terephthalamide) fibers was 24%, which was 25+01% lower than that of untreated fibers (s, o%).

Claims (1)

[Claims] 1. General formula -NH-Ar_1-NH-CO-Ar_2-
A wholly aromatic polyamide molded article having a repeating unit of CO and/or -NH-Ar_3-CO- (wherein Ar_1, Ar_2, and Ar_3 each independently represent a divalent aromatic cyclic group), A part or all of the amide bonds on the surface of the polyamide molded product are converted into N- or O-substituted derivatives by reacting with a halogen compound, heterocyclic compound, ester compound, alcohol, organic acid, or Michael acceptor while heating. A method 2 for producing a wholly aromatic polyamide molded article with a surface hydrophobicity characterized by Manufacturing method 4 according to claim 1, wherein the aromatic polyamide molded article is a wholly aromatic polyamide woven fabric; Claim 1, wherein the wholly aromatic polyamide molded article is a wholly aromatic polyamide film Manufacturing method described