JPS6010055B2 - Flame retardant polyamide composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to flame retardant polyamide compositions.

Polyamides, especially nylon 6 and nylon 66, are widely used as fibers and other molding materials because of their excellent mechanical properties, good dyeability, and beautiful appearance.

However, polyamides have the disadvantage of being easily combustible, which limits their use. A known method for imparting flame retardancy to polyamides is to treat the surface of polyamide molded articles, for example polyamide fibers, with an elutriation agent such as thiourea.

However, in order to obtain a sufficient elutriation effect with this method,
It is necessary to increase the amount of flame retardant deposited, which not only significantly affects the appearance and texture of the product, but also has the disadvantage that the flame retardant effect is poor in durability. As a method of eliminating such drawbacks, various attempts have been made to add a flame retardant to the polyamide before it is molded.

However, the flame retardants that have been proposed do not have a sufficient flame retardant effect on polyamides, and require a large amount of addition to improve the effect. Moreover, since many of the bonito retardant agents have reactivity with polyamide, adding a large amount of bonito retardant agents causes undesirable phenomena such as significant decomposition, foaming, gelation, and coloring of the polyamide, which may cause damage to the original properties of the polyamide. Physical properties and commercial value are highly valued. For example, although decabromo biphenyl and decabromo biphenyl ether described in British Patent No. 1158163 are known as flame retardants, they have poor compatibility with polyamide and poor moldability, making it difficult to obtain homogeneous molded products. Furthermore, the molded product obtained becomes cloudy and becomes what is called a "dulled" product.Also, when tetraprom phthalic anhydride, tetrachloro phthalic anhydride, het acid, tetrabromo bisphenol A, etc. are added to the polyamide. When mixed and molded, the resulting molded product becomes extremely colored and loses its commercial value.Furthermore, hexabromobenzene and the like cause significant smoke sublimation during the polyamide molding process, which is also undesirable.Furthermore, , Hakama Kosho 48-422
2,416-tribromoacetanilide and the like described in Japanese Patent No. 09 have the disadvantage that they elute onto the surface of the molded product even after molding, and the durability of the flame retardant effect is also poor. Such a melting phenomenon brings about undesirable effects such as yarn breakage during the drawing and warping process, especially when polyamide is made into fibers. The object of the present invention is to provide a polyamide composition which has durable flame retardancy without sacrificing any of the excellent properties of polyamide, and which does not have the drawbacks of the prior art as described above.

That is, the present invention provides a flame-retardant polyamide composition containing 0.5 to 25% by weight of a nuclear halogenated benzoic acid compound represented by the following general formula [1] based on the total weight of the polyamide composition. be.

(However, x represents chlorine or bromine, R represents a methyl group or ethyl group, 1 represents an integer of 1 to 5, and m represents an integer of 0 or 1 to 2.) The polyamide used in the present invention is an ordinary polyamide. Synthetic linear polyamides, such as nylon 6, nylon 10, nylon 11, nylon 12, nylon 6
0 Examples include nylon 610 and copolyamides containing these as main components, particularly nylon 6 and nylon.

66 is preferably applied. The nuclear halogenated benzoic acid compound used in the present invention is represented by the above general formula [1].

Such nuclear halogenated benzoic acid compounds include, for example, monochlorobenzoic acid (2-substituted, 3-substituted, 4-substituted) dichlorobenzoic acid (2,4-substituted, 2,5-substituted, 2,6-substituted). Substituted product, 314-substituted product, 315 single layer fusuma body)
, monochloromonobromobenzoic acid (2-chloro-4-from-substituted product, 2-from-4-chloro-substituted product, 2-chloro-5-from-substituted product, 2-from-5-chloro-substituted product, 2-chloro-6-from substituted product) 3-chloro-4-from-substituted product (3-chloro-4-from-substituted product), trichlorobenzoic acid (2
0314-substituted product, 2.305 single layer fusuma body, 20316 single layer fusuma body, 2.4.5-substituted product, 2.466 single layer specimen, 3
1415 monosubstituted), monochlorodibromobenzoic acid (2
-chloro-4,6-difurome substituted product, 4-chloro-30
5-dibrome substituted product, 2,4-dibromo-6-chloro substituted product, 2-chloro-306-dibrome substituted product, 3-chloro-206-dibrome substituted product, 203-dibrome-6-
chlor-substituted), 2131405-tetrachlorobenzoic acid, 203'41516-pentachlorobenzoic acid, monobrombenzoic acid (2-substituted, 3-substituted, 4-substituted), diprombenzoic acid (234-substituted, 215-substituted), Substituted product, 206 monosubstituted product, 304 monosubstituted product, 3'5-substituted product), trifluorobenzoic acid (21304-substituted product, 2.3-substituted product),
05-substituted product, 214.5 monolayer, 204'6-substituted product, 3.405-substituted product), 2030416-tetrabromobenzoic acid, 283'405.6-pentabromobenzoic acid, monochloro-orthotolulic acid ( 3-substituted product,
4-substituted, 5-substituted, 6-mono-substituted), monochloro-meter-toluic acid (4-substituted, 5-mono-substituted, 6-mono-substituted), monochloro-paratoluic acid (2-substituted, 3-substituted)
monosubstituted), 416-dichloroorthotoluic acid,
4,6-dichloro-methatoluic acid, 2,5-dichloro-paratoluic acid, 3,5-dichloro-paratoluic acid, monobromo, ortho-toluic acid (4-substituted, 5-mono-substituted, 6-substituted) monobromoparatolylic acid (4-substituted, 5-substituted, 6-substituted), monobromoparatolulic acid (2-substituted, 3-substituted)
, difuromorthotoluic acid (4,5-substituted product, 4
・6-mono-substituted), 4,6-dibromo-methatoluic acid, dibromo-para-toluic acid (2,5-mono-substituted, 2-
6-substituted product, 3,5-substituted product), 2,4,5,6-tetrachloro-methatoluic acid, 2,3,5,6-tetrachloro-paratoluic acid, 3-from-6-chloro-methatoluic acid Examples include toluic acid. These compounds themselves are thermally stable and provide an excellent broiling effect without degrading the physical properties of the polyamide. Among these, nuclear brominated benzoic acid compounds are preferred from the viewpoint of color tone of polyamide molded products. On the other hand, the number of nuclear substituted halogens is 1 to 2 because the compound itself is easy to manufacture and a highly pure product can be obtained.
is preferable, and from the viewpoint of the cost of the compound, those without a nuclear substituted methyl group or ethyl group are preferable. Among these, parabrombenzoic acid is a particularly preferred compound. The amount of the above-mentioned compound added can be appropriately selected depending on the intended use of the polyamide molded product.

Generally, the flame retardance increases as the amount added increases, but it should be added within a range that does not affect the moldability and quality of the molded product, and is usually 0.5% to the final polyamide product.
It may be used in a range of 25% by weight. Among these, a range of 2 to 1% by weight is preferred. If the amount of the compound added is less than 0.5% by weight, sufficient flame retardant performance cannot be obtained, whereas if it exceeds 25% by weight, moldability and quality of the molded product will be affected. do not have. As a method for blending and molding the above compound into a polyamide, for example, a predetermined polyamide and the compound are mixed in a rotating drum, or a mixture obtained by mixing the polyamide and the compound in a mixer is mixed using a known extruder. Alternatively, it can be melted and molded using a grid-type melting device or the like.

It is also possible to prepare a master chip by previously mixing and melting the compound in polyamide at a high concentration, and then mixing and diluting the compound to a predetermined concentration and molding the master chip. The molding temperature can be arbitrarily selected depending on the polyamide used and the type and amount of the compound added, but it is generally desirable to be in the range of not less than the melting point of the polyamide and not more than the melting point +80 qo. Preferably, the melting point of the polyamide is 10 (
The range is from 10 to 50 p.m. The nuclear halogenated benzoic acid compound according to the present invention does not cause coloration or gelation of polyamide, and since the compound itself has high stability against light and heat, it can be obtained without decomposing during molding processing. Flame-retardant polyamide molded products have extremely excellent properties such as quality, whiteness, and light resistance.

Moreover, the compound has extremely good compatibility with polyamide, and the resulting polyamide molded product has no clouding phenomenon and has excellent transparency and gloss. Because of these properties, the flame-retardant polyamide composition of the present invention is particularly suitable for fiberization, and can be easily formed into fibers by known methods for producing polyamide fibers.

That is, for example, flame-retardant polyamide fibers can be obtained by melting the flame-retardant polyamide composition in the form of chips with an extruder, measuring it with a gear pump, extruding it from gold, drawing the filament, and drawing the flame-retardant polyamide fiber. . The thus obtained flame-retardant polyamide fibers are no different from ordinary polyamide fibers in terms of strength, elongation, dyeability, etc., and the compound does not elute even after repeated home washing or dry cleaning. It is advantageous in that it does not cause any deterioration in flame retardancy or hygienic problems because it does not peel off or fall off. Further, the nuclear halogenated benzoic acid compound according to the present invention imparts extremely excellent flame retardancy to polyamide when added in a small amount, but it is also possible to further improve the effect by using it in combination with other flame retardants. In this case, as the retardant used in combination, halogen-containing compounds, antimony compounds, tin compounds, other metal oxides, etc. are preferable. Furthermore, there is no problem in adding third components such as matting agents, antioxidants, heat stabilizers, light stabilizers, antistatic agents, colorants, optical brighteners, etc. to the flame-retardant polyamide composition of the present invention. do not have. The present invention will be explained in detail below with reference to Examples.

In the examples, "%" means "wt%" unless otherwise specified, and the relative viscosity (rel) is determined by dissolving the polyamide to a concentration of 1% in concentrated sulfuric acid and using an Ostwald viscometer at 25q0. The measured values are shown. Flame retardancy is evaluated using the limiting oxygen index (L.〇1) according to the following measurement method.
．． It is abbreviated as. ) and the number of flame reinforcements by the 45o coil method. (a) L. 0.1. Measurement method JIS-K-7
201-1972 according to L. 0.1. was measured.

[b} 450 Method for measuring the number of times of flame contact using the coil method A twisted rod weighing 1 hour, 10 mm long, and 10 twists was made from the fiber to be tested, and this twisted rod was made of stainless steel with a side of 0.5 Insert the wire into a coil with a diameter of 1 length, a coil pitch of 2 sides, and a length of 15 mm, and hold it at a 45 degree angle until the flame length is 4.
Use a 5-piece micro-burner to set a flame on the bottom end of the machine and burn it, and when the flame goes out, shift the position and re-light the bottom end of the aircraft.

In this way, the number of times the flaming occurred until the 10 skins of the twisted rod were completely burnt out was measured, and the average value of the 5 times was shown. The compatibility test method and evaluation method are as follows. 3 ratio guy? Into a 20x test tube, mix approximately 27 pieces of polyamide bright pellets and the specified amount of the compound and then add it.

To prevent oxidation of the polyamide, the test tube is heated to above the melting point of the polyamide while flowing nitrogen to melt the contents. After melting, mix thoroughly and uniformly with a rope rod. Next, the state of the melt was observed with the naked eye through the glass wall, and the evaluation was roughly divided into the following three stages. ○ - Dissolved uniformly, the polymer was transparent, and there was no oil droplet dispersion.

△: Most of the polymer is dissolved, but the polymer is translucent due to some dispersion.

x - The polymer is opaque and a large amount of undissolved matter is dispersed.

However, if the item is located in the middle of the above three stages, an intermediate display such as ◯ or △ is used.

The evaluation criteria for colorability are as follows.

That is, the colored state of the molded product was visually evaluated as follows.

◎-No coloring at all, equivalent to unmodified polyamide.

- Slightly colored, but similar to unmodified polyamide.
Δ-Coloring is clearly observed compared to unmodified polyamide.

× - Significant coloration compared to unmodified polyamide.

However, if the item is at an intermediate stage, an intermediate display such as △× is used.

Example 1 Nylon 6 chip (relative viscosity 2.60 moisture content 0.08%
), parabrobenzoic acid and similar compounds as shown in Table 1 were thoroughly mixed in advance, and the mixture was woven at a temperature of 265 oo and a weaving speed of 600 m using an ordinary extruder type loom.
/min.

Next, it is stretched 3.4 times and made up of 10 filaments.
Obtained denier fiber. The flammability of the obtained fibers was tested by L. 0.1. This was done by measuring the number of flares using the 450 coil method. Furthermore, uniformity was evaluated as follows.

○...Less thread breakage similar to unmodified nylon 6 10
Thread breakage is less than 1 time per 0 direction. △...The thread breaks about 5 to 20 times per million skins.

×... Yarn breakage occurs frequently and a satisfactory spun yarn cannot be obtained. The evaluation methods for compatibility, colorability, etc. are as described above.

The compounds used as comparative examples are as follows.

That is, No. 1 is 1,2,4-triprombenzene having no nuclear substituent, NO. 2 has a methyl substituent 2.
405-Tribromtoluene, No. 3 is 204,6-tribromophenol having a phenolic OH group.
No. 4 is 21416-tribromoaniline having an amino group, No. 5 is parabromoacetanilide having an acetyl group. As is clear from Table 1, No. 3 had poor colorability and ironability and was unable to obtain a sample yarn.

Also No. No. 1, 2, and 4 had good compatibility and paperability, but some coloring was observed. 5 is compatibility, colorability,
Both paperability and paperability were good. However, the flame retardant performance of these materials was completely the same as that of ordinary nylon 6 (No. 6), despite the relatively high bromine concentration.

On the other hand, No. No. 7 (product of the present invention) had good phase properties, coloring properties, and spinnability, and its flame retardant performance was also significantly improved compared to each comparative example. Table 1 Example 2 Nylon 6 chips (relative viscosity 2.70) were mixed with compounds known as chick retardants listed in Table 2, parabrobenzoic acid, 3,4-dichlorobenzoic acid and 4-dichlorobenzoic acid according to the present invention.・
6-dichloroorthotolulic acid was thoroughly mixed in advance and melt-kneaded at 260 qo using an extruder type extruder to create a sheet with a thickness of 3 feet, 6.5 cm wide and 15 cm long. I cut out his test piece.

L. of the obtained test piece. 0.1. The compatibility and colorability were also measured and evaluated using the methods described above. Table 2 NO. 1 and NO. No. 2 has poor compatibility with nylon 6, and the molded product becomes dull.

Moreover, moldability is also poor. Furthermore, coloration was observed in all cases,
No. 2 is particularly remarkable. In addition, flame retardant performance was observed, but it was considerably inferior to the product of the present invention, even though the amount added was twice that of the product of the present invention. No. 3 and no. Although coloring and flame retardant properties were observed in all of No. 5, they were considerably inferior to the products of the present invention. No. Sample No. 4 suffered from severe discoloration and decomposition, and it was not possible to obtain a molded product. No. 6 and 7 are phosphorus compounds.

Although these have good coloring properties, their flame retardant properties are completely inadequate. In the case of polyester, it is known that flame retardant performance is good if the phosphorus compound contains about 5000 phosphorus atoms, but the results with nylon 6 are surprising, and the The difficulty of making flame retardant is similar. NO. No. 8 is a type of phosphate ester containing a halogen, but it has insufficient compatibility, significant coloring, and insufficient flame retardant effect.

As mentioned above, compounds known as flame retardants are added to nylon 6.
When 12% of the compound was added, problems such as compatibility, colorability, decomposition and deterioration properties occurred. For example, in order to improve these problems, it is possible to reduce the amount added, but even at 12% shown in Table 2, the flame retardant performance is insufficient, so reducing the amount further is not recommended. This further deteriorates the flame retardant performance, and there is no point in adding a flame retardant. On the other hand, No.
It will be understood that the products of the present invention shown in Nos. 10 to 12 have almost no problems with compatibility, coloration, etc., and their flame retardant performance is very excellent.

Example 3 Nylon 6, full dual tip (relative viscosity 2.
60, moisture content 0.08%), compounds known as nada retardants listed in Table 3 and 2,4,6-tribrobenzoic acid, trichlorobenzoic acid, monofurom-
Metatolylic acid was blended and melt paper yarn was prepared in the same manner as described in Example 1, and flame retardant performance etc. were evaluated.

No. 1 and no. 2 has concerns about colorability and susceptibility,
Also, flame retardant performance is insufficient.

No. No. 3 has no particular problems with compatibility, colorability, paperability, etc., but white powder, which is thought to be a compound added during stretching, is a guide,
The elution phenomenon of adhesion to rollers, etc. is observed, causing thread breakage, which is undesirable, and the flame retardant performance is also insufficient. N
o. Although the flame retardant performance of No. 7 is relatively good, it cannot be said to be sufficient, and there is also a problem with the colorability. No. No. 4 was a chlorine compound, but it was not compatible with the chlorine compound, and when the paper was unloaded, the yarn broke frequently and the nozzle was clogged, making it impossible to wind it up. No. As can be seen from the table, No. 5 is completely defective. No. No. 6 has good compatibility, colorability, and gradeability, but No. An elution phenomenon similar to that in case 3 was observed. Furthermore, contrary to our expectations, the flame retardancy did not improve at all. As mentioned above, when 10% of a compound known as a flame retardant is blended into nylon 6 and made into a melt-woven paper yarn to obtain fibers, the following properties are observed: We were unable to find anything that showed satisfactory flame retardant performance.

On the other hand, the products of the present invention shown in Nos. 9 to 11 do not have the above-mentioned drawbacks, and nylon 6 fibers with very excellent flame retardancy were obtained even at a blending amount of 5%.

Table 3 Example 4 Nylon 6 chips (relative viscosity 2.70) were thoroughly mixed with parabrobenzoic acid in various proportions, and test pieces were obtained in the same manner as in Example 2.

L. of the obtained test piece. 0.1. was measured, and compatibility and colorability were evaluated using the methods described above. The results are shown in Table 4. As is clear from Table 4, when the content is less than 0.5%, the flame retardancy improves only slightly, but when the content is 0.5% or more, flame retardancy is observed.

Moreover, when it is 2% or more, excellent flame retardancy is exhibited, and when it exceeds 10%, the flame retardance is almost saturated. On the other hand, from the viewpoint of compatibility and colorability, the content is preferably 25% or less, particularly preferably 10% or less. Table 4 Example 5 Nylon 6 Fludull chips (relative viscosity 2.80, moisture content 0.075%) were thoroughly mixed with 20% by weight of 2,4-dibromobenzoic acid, and 25% by weight was mixed using an extruder.
000 to obtain a master chip.

This master chip was thoroughly mixed with nylon 6 full dull chips (relative viscosity 2.80, moisture content 0.075%) so that the content of 2,4-dibromobenzoic acid was 5.5% by weight, and then passed through an extruder type spinning machine. using 255oo
It was melt spun at a temperature of . Next, stretch it to about 3.3 times and
A 40 denier fiber consisting of filaments was obtained. The strength of this fiber was 4.8 m/d and the elongation was 35%, which was not much different from that of unmodified nylon 6 ordinary yarn.This fiber was warped and knitted in the usual way to make a tricot sample. Sutra,
There were no particular problems with workability during knitting, and the results were comparable to those of unmodified nylon 6. This tricot sample was also subjected to conventional scouring and dyeing. Dyeing was carried out by both dispersion dyeing and acid dyeing, and the dyeability was good with no significant difference from unmodified nylon 6. In order to evaluate the flame retardant performance of the obtained dyed tricot cloth, the number of flames was measured.

As a result, *the tricot cloth according to the present invention has a bush flame count of 5
The flame retardant performance was excellent. On the other hand, the unmodified nylon 6 fabric obtained using the same machine was used only once. As described above, the flame-retardant nylon fiber according to the present invention has no particular problems in post-processing steps such as warping, knitting, and dyeing, and the resulting product has excellent flame-retardant performance. The thing has become clear. Example 6 Nylon 66 chips (relative viscosity 2.50) were thoroughly mixed with the compounds listed in Table 5, and the same method as Example 2 was used except that the molding temperature was 27,500 and a three-legged sheet was molded. The L. 0.1. was measured.

Compatibility, colorability, etc. were also evaluated. Table 5 No.
．． No. 1 is a type of phosphate ester containing bromine and chlorine.

This has problems with compatibility, is significantly colored, and has insufficient flame retardant performance even though the amount added is 10%. On the other hand, No. The products of the present invention shown in Nos. 3 to 5 do not have the above-mentioned problems, and their flame retardancy is excellent even though the amount added is small.

Claims (1)

[Scope of Claims] 1. A flame-retardant polyamide composition containing 0.5 to 25% by weight of a nuclear halogenated benzoic acid compound represented by the following general formula [I] based on the total weight of the polyamide composition. thing. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, X is chlorine or bromine, R is a methyl group or an ethyl group, l is an integer from 1 to 5, and m is an integer from 0 or 1 to 2.) 2. The flame-retardant polyamide composition according to claim 1, wherein the polyamide is nylon 6 or nylon 66. 3. The flame-retardant polyamide composition according to claim 1, wherein in the nuclear halogenated benzoic acid compound represented by general formula [I], X is bromine. 4. The flame-retardant polyamide composition according to claim 1 or 3, wherein in the nuclear halogenated benzoic acid compound represented by general formula [I], l is an integer of 1 to 2. 5. The flame-retardant polyamide composition according to claim 1 or 3, wherein m is 0 in the nuclear halogenated benzoic acid compound represented by general formula [I]. 6. The flame-retardant polyamide composition according to claim 1, wherein the nuclear halogenated benzoic acid compound represented by general formula [I] is parabromobenzoic acid. 7 The content of the nuclear halogenated benzoic acid compound represented by general formula [I] with respect to the total weight of the polyamide composition is 2 to 10
% by weight of the flame retardant polyamide composition according to claim 1.