JPS6237052B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing aromatic polyamide moldings with significantly improved heat resistance, electrical performance and dimensional stability. More specifically, aromatic polyamide molding has significantly improved electrical properties, dimensional stability, and heat resistance by blending a specified crosslinking compound and silicone compound and treating it with heat, ultraviolet rays, and/or electron beams, etc. It relates to methods of manufacturing things. Aromatic polyamides have excellent heat resistance and mechanical properties, and include P-phenylene terephthalamide polymers, halogen-substituted P-phenylene terephthalamide polymers, p-phenylene isophthalamide polymers, and m-phenylene terephthalamide polymers. - Polymers such as phenylene isophthalamide-based polymers are polymer materials that have received particular attention in recent years and have been used in a wide variety of fields such as fibers and synthetic papers. However, although molded products such as films and sheets made of aromatic polyamides have excellent performance, they have poor electrical properties and dimensional stability due to moisture absorption compared to molded products such as polyimide films. However, it is not necessarily satisfactory as a high-performance molded product, and there is currently a strong desire to improve these various performances. One way to solve this problem is to
- In the case of phenylene isophthalamide polymer films, a method of treating the film with long-chain fatty acids, fluorinated or chlorinated aliphatic carboxylic acids, or aromatic hydrocarbons having methyl groups; A method of incorporating a silicone polymer or a fluorine polymer into a film, and a method of coating the surface of the film with a silicone polymer or a fluorine polymer are disclosed in Japanese Patent Application Laid-Open No. 1983-1999.
122160, JP 51-122173, JP
It has been proposed in JP-A-51-122174, JP-A-52-41899, JP-A-52-41900, etc., and the electrical properties are further improved by stretching the film in two axial directions. Methods and the like are disclosed in JP-A-52-56169, JP-A-52-152973, and the like. Furthermore, in Japanese Patent Publication No. 53-45238, an attempt has been made to subject a halogen-substituted p-phenylene terephthalamide film to tension heat treatment to lower its moisture absorption rate and improve its electrical properties. There is. However, although all of these methods have some effects, they are insufficient to fundamentally improve dimensional stability and electrical properties due to the hygroscopic nature of the polar amide groups of aromatic polyamides, and are not necessarily at a satisfactory level. The current state of the art is such that the performance of this technology has not been achieved. In contrast to these prior art techniques, the present inventors blended aromatic polyamide with a specific crosslinking compound,
We have attempted to develop a new technology that can significantly improve electrical properties and heat resistance by treating it with ultraviolet rays and electron beams, and have previously proposed it. However, even in this case, when viewed from the viewpoint of moisture absorption dimensional stability, although there is a significant improvement compared to the aromatic polyamide molded product in which the invention is not adopted, it is still not as good as the polyamide molded product. It wasn't enough. The inventors of the present invention fully took into account this point of view, and as a result of intensive studies aimed at fundamentally improving not only electrical properties and heat resistance but also moisture absorption dimensional stability, the inventors added a predetermined amount of aromatic polyamide polymer to By blending specific crosslinking compounds and silicone compounds, especially reactive silicone compounds, and subjecting them to ultraviolet or electron beam treatment and heat treatment, not only electrical properties and heat resistance but also hygroscopic dimensional stability can be improved. The present invention was achieved by discovering a new method for obtaining significantly improved aromatic polyamide molded articles. That is, the present invention provides an aromatic polyamide polymer having (a) the following general formula:

【formula】

【formula】

【formula】

【formula】

[Formula] (where R ₁ , R ₂ , and R ₃ represent hydrogen or an alkyl group) A crosslinkable compound containing at least one group represented by the formula and (b) a silicon-based compound, especially a compound with the general formula XSi
(OR) ₃ (where R is an alkyl group and X is an organic functional group containing an amino group, a mercapto group, a vinyl group, an epoxy group, or a methacryloxy group) was blended and molded. After that, the molded product is treated with ultraviolet rays, electron beams, or both, and then heat treated at a temperature of 100°C or higher to produce an aromatic polyamide with significantly improved heat resistance, electrical properties, and hygroscopic dimensional stability. This is a method for manufacturing molded products. The aromatic polyamide polymer used in the present invention has the general formula

【formula】

It is an aromatic polyamide polymer containing a repeating structural unit represented by the formula either singly or in the form of a copolymer, preferably an aromatic polyamide polymer containing 50 mol% or more of the structural unit. Here, Ar ₁ and Ar ₂ are aromatic groups having divalent bonds, and may be the same or different, and a typical one thereof has the following structural formula.

【formula】 【formula】

【formula】

【formula】

【formula】

【formula】

Here, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ are lower alkyl, lower alkoxy, halogen or nitro group, and n ₁ , n ₂ , n ₃ are 0 to 4 including 0 and 4.
is an integer, and X ₁ and X ₂ are

【formula】

【formula】 -O-,

【formula】

One selected from [Formula], where Y, Y ₁ and Y ₂ represent hydrogen or a lower alkyl group. Typical aromatic polyamide polymers used in the present invention include poly-m-phenylene isophthalamide or a copolymer thereof, poly-m-phenylene terephthalamide or a copolymer thereof, poly-p-phenylene Isophthalamide or its copolymer, poly-p-phenylene terephthalamide or its copolymer, p-berezamide or its copolymer, 3,4'-diphenyl ether terephthalamide or its copolymer, 2,2 - Polyamides made of bis[4-(4-aminophenoxy)phenyl]propane and terephthalic acid chloride or isophthalic acid chloride, or copolymers thereof, etc., but aromatic polyamide-based polymers are limited to these. isn't it. The aromatic polyamide polymer can be obtained by using a solution polymerization method, an interfacial polymerization method, or the like using a predetermined aromatic dicarboxylic acid halide and an aromatic diamine. The following are representative examples of crosslinking compounds that can be blended into the aromatic polyamide polymer in the method of the present invention to exhibit the effects of the present invention. That is, (1) general formula

【formula】

A group of compounds containing at least one group represented by the formula: Here, R ₁ , R ₂ , and R ₃ represent hydrogen or an alkyl group, and representative compounds of this group include the general formula There is a group of compounds shown in Here, R' ₁ , R' ₂ , R' ₃ , R' ₄ represent hydrogen, an alkyl group, a hydroxyalkyl group, a carboxyalkyl group, a halogenated alkyl group, and n is 1
or more, and at least one of R' ₁ , R' ₂ , R' ₃ , and R' ₄ is a functional group with radical reactivity, such as an unsaturated alkyl group, an allyl group, etc. It won't happen. Representative examples of such compounds include triallyl cyanurate, diallylmethyl cyanurate, polyethylene allyl cyanurate,
Triallyl isocyanurate, diallylmethyl isocyanurate, polyethylene allyl isocyanurate, ethylene bis(diallyl cyanurate), tetramethylene bis(diallyl cyanurate), ethylene bis(diallyl isocyanurate), tetramethylene bis(diallyl isocyanurate), diallyl Examples include hydroxyethyl cyanurate, diallyl hydroxyethyl isocyanurate, diallyl carboethoxy cyanurate, diallyl carboethoxy isocyanurate, diallyl chloroethyl cyanurate, diallyl chloroethyl isocyanurate, and the like. More typical examples include diallyl malonate, diallyl succinate, diallyl glutarate,
Dicarboxylic acid diallyl esters such as diallyl adipate and diallyl azelate, allyl-substituted melamines such as N,N-diallylmelamine, hexaallyloxymethylmelamine, hexaallylmelamine and triallylmelamine, and the like. (2) General formula

【formula】

A group of compounds containing at least one group represented by the formula: Here, R″ ₁ , R″ ₂ , R″ ₃ represent hydrogen or an alkyl group, and representative examples of such compound groups include acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, etc. , methyl methacrylate, ethyl methacrylate, methacrylic acid 2
- Methacrylic acids such as hydroxyethyl, acrylic acids such as ethylene glycol and polyethylene glycol, or esters with methacrylic acid;
Examples include amides of acrylic acid and methacrylic acid such as acrylamide and methacrylamide, and other general crosslinking compounds can also be used as necessary. 1 selected from the compound groups shown in (1) to (2)
The content of one or more crosslinking compounds is 10% by weight or less, preferably 0.5 to 10% by weight, based on the aromatic polyamide polymer.
It is preferable to mix it in a range of 5% by weight. Further, in the present invention, representative silicone compounds that can be blended together with the crosslinking compound to exhibit the effects of the present invention include silicone oils such as methyl silicone oil, phenyl-modified silicone oil, and amine-modified silicone oil. More preferred are so-called silane coupling agents represented by the general formula XSi(OR) ₃ . Here, R represents an alkyl group, and X represents an organic functional group including an amino group, a mercapto group, a vinyl group, an epoxy group, and a methacryloxy group. Typical examples of these silane coupling agents include vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and N-β(aminoethyl )-γ-aminopropyltrimethoxysilane, β-(3,4
Examples include epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxy-propyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane. The blending ratio of the silicone compound used in the present invention is 30% by weight based on the aromatic polyamide polymer.
or less, preferably 20% by weight or less, more preferably
A range of 0.5% to 10% by weight is good. If the blending ratio is 30% by weight or more, the heat resistance, which is an inherent characteristic of aromatic polyamide polymers, will be impaired, which is not preferable. If the mixing ratio is less than 0.5% by weight, it is insufficient to achieve the effects of the present invention. When carrying out the method of the present invention, a predetermined aromatic polyamide polymer is mixed with an amide solvent such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, etc., and optionally with calcium chloride, lithium chloride, or chloride. A predetermined crosslinkable compound and a silicone compound are added and mixed to a polymer solution dissolved in the above-mentioned amide solvent containing metal halides such as magnesium, lithium bromide, calcium bromide, and ammonium bromide. Fibers, films, and pulp can be produced by blending the composition and using conventional methods such as dry, wet, semi-dry and semi-wet methods. When the aromatic polyamide molded product is a film, the polymer composition containing the crosslinkable compound and the silicone compound is produced in a batch or continuous manner using a dry, wet or semi-dry/semi-wet process. It is preferable to stretch the film in uniaxial or biaxial directions in hot water or in a steam atmosphere, if necessary. At this time, in addition to the crosslinking compound, a silicone compound is also added.
The aromatic polyamide film containing 30% by weight or less has excellent stretchability, especially improved stretchability during sequential biaxial stretching. This is another advantage of the invention. After drying the stretched film to a fixed length,
and an electron beam, and then heat-treated the film at a temperature of 100°C or higher, preferably 200°C or higher, and more preferably 300°C or higher under constant length or tension to improve heat resistance and electrical properties. Therefore, an aromatic polyamide film with excellent humidity and dimensional stability can be obtained. As the silicon compound of the present invention, an aromatic polyamide molded product obtained by blending a compound represented by the general formula XSi(OR) ₃ , which is a so-called silane coupling agent, and a crosslinking compound is treated with ultraviolet rays and/or an electron beam. After that, heat treatment is performed at a temperature of 100° C. or higher, preferably 200° C. or higher, and when formed into a sheet-like product such as a film, it can be made into a sheet-like product with extremely excellent transparency. In carrying out the present invention, in addition to adding and blending the crosslinking compound and silicone compound into the polymer solution as described above, the crosslinking compound and silicone compound may be added as they are, or may be mixed with acetone, methanol, etc. It is also possible to dissolve these compounds in a low boiling point solvent such as benzene, mix them with the aromatic polyamide powder, and then remove the low boiling point solvent before blending. When this method is adopted, a polymer containing a crosslinkable compound and a silicone compound is dissolved in the amide solvent described above to obtain a polymer solution, and in addition to obtaining a molded article by the method described above, the crosslinkable compound and silicone compound are dissolved. It is also possible to produce a sheet-like product using a compression molding machine such as a press from a polymer composition blended with a system compound. At this time, when a reactive silicone compound represented by XSi(OR) ₃ is used as the silicone compound, the silicone compound becomes a plasticizer and
As mentioned above, the silicone compound is extremely effective as a reactive plasticizer that reacts with the aromatic polyamide polymer and the silicone compound to form a new molded product by performing pressure heat treatment preferably at a temperature of 150°C or higher. This is a novel and useful effect of the present invention. The upper limit temperature is approximately 400℃ for polymethaphenylene isophthalamide-based polymers, and approximately 400°C for polyparaphenylene terephthalamide-based polymers.
The heat treatment temperature can be appropriately selected up to 600℃. Next, the present invention will be explained in more detail with reference to Examples. All parts in the examples are by weight. Example 1 20 parts of m-phenylene isophthalamide polymer containing 3 mol% terephthalic acid units (intrinsic viscosity 1.36, determined in NMP at a polymer concentration of 0.5% by weight), 4 parts of lithium chloride, triallylisocyanurate
A polymer solution consisting of 0.6 parts of γ-glycidoxypropyltrimethoxysilane, 1 part of γ-glycidoxypropyltrimethoxysilane, and 80 parts of dimethylacetamide was cast onto a glass plate using a doctor knife, dried at 140°C for 7 minutes, and then immersed in water to form a transparent film. Obtained. The obtained film was sequentially stretched 1.8 times biaxially in hot water at 95°C, and then dried to a fixed length to obtain a 25μ film. this film
Irradiated with ultraviolet light for 5 minutes with a 2KW ultraviolet lamp, then
Heat treated at 350℃ for a constant length. The performance of the aromatic polyamide film thus obtained is shown in Table 1, and it is recognized that it exhibits extremely high performance. The film performance in the case where triallylisocyanurate or γ-glycidoxypropyltrimethoxylan was not used is shown as a comparative example.

[Table] Examples 2 to 9 Various films were prepared in the same manner as in Example 1 using various crosslinking compounds and silane compounds instead of triallylisocyanurate and γ-glycidoxypropyltri-methoxysilane. Obtained. As shown in Table 2, the obtained films all exhibited excellent performance.

[Table] Example 10 Aromatic polyamide polymer consisting of 60 mol% metaphenylenediamine units, 40 mol% paraphenylenediamine units, and terephthalic acid chloride (intrinsic viscosity 4.29 as measured in 0.5% by weight concentrated sulfuric acid solution)
6 parts, calcium chloride 2.8 parts, triallylisocyanurate 0.18 parts and γ-glycidoxypropyltrimethoxysilane (SH- manufactured by Toray Silicon Co., Ltd.)
A polymer solution consisting of 0.3 parts of 6040), 0.8 parts of water, and 90.9 parts of N-methyl-2-pyrrolidone was cast onto a glass plate using a doctor knife, dried at 140°C for 7 minutes, and then immersed in water to obtain a transparent film. Ta. When I tried to stretch the obtained film in boiling water, it was stretched in two directions.
Stable stretching was possible at a stretching ratio of 1.5 times. After stretching, the film was irradiated with ultraviolet light for 1 minute using a 2Kw ultraviolet lamp, and then heat-set at 350°C under a fixed length to obtain a 25μ film. The dielectric breakdown voltage of the obtained film was 280Kv/
mm, shrinkage rate after 10 seconds soldering bath at 260℃ is 0.7%
It was hot. Note that when a film was similarly produced without using γ-glycidoxypropyltrimethoxysilane, the biaxial stretching ratio was at most 1.2 times. The shrinkage rate of the obtained film after being treated in a solder bath at 260°C for 10 seconds was 1.9%. Example 11 50 3,4'-diaminodiphenyl ether units
6 parts of p-phenylene terephthalamide polymer (intrinsic viscosity 2.89 measured with 0.5% by weight concentrated sulfuric acid solution) containing mol%, 2.3 parts of calcium chloride, 0.18 parts of triallylisocyanurate, γ-glycidoxypropyltrimethoxy Silane (manufactured by Toray Silicon Co., Ltd.)
A polymer solution consisting of 0.3 parts of SH-6040) and 94 parts of N-methyl-2-pyrrolidone was cast onto a glass plate, immersed in water, and then biaxially stretched 1.8 times in hot water at 95°C. Drying, UV irradiation, and heat fixation were performed in the same manner as in 10. The shrinkage rate of the obtained film after being treated in a solder bath at 260° C. for 10 seconds was 0.3%. For comparison, when a film was produced in the same manner without adding γ-glycidoxypropyltrimethoxysilane, the stretchability was poor, especially the biaxial stretchability during sequential stretching, and the film was stretched 1.3 times or more. was difficult. Further, the shrinkage rate of the obtained film after being treated in a solder bath at 260° C. for 10 seconds was 1.0%.

Claims (1)

[Scope of Claims] 1. An aromatic polyamide polymer having (a) the following general formula [Formula] [Formula] [Formula] [Formula] [Formula] (where R ₁ , R ₂ , R ₃ are hydrogen or A crosslinkable compound containing at least one group represented by (alkyl group) and (b) a silicon-based compound are blended and molded, and after being treated with ultraviolet rays and/or electron beams,
A method for producing an aromatic polyamide molded article, characterized by heat treatment at a temperature of ℃ or higher. 2 A silicon-based compound is represented by _the following general formula A method for producing an aromatic polyamide molded article according to claim 1, which is a compound.