JPS6010056B2 - Flame retardant polyamide composition - Google Patents

Description

[Detailed description of the invention] FIELD OF THE INVENTION This 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. As a method for imparting flame retardancy to polyamides, a method is known in which the surface of polyamide molded articles, for example polyamide fibers, is treated with a flame retardant such as thiourea.

However, in order to obtain a sufficient effect with this method, it is necessary to increase the amount of flame retardant applied, which not only significantly impairs the appearance and texture of the product, but also results in poor durability of the effect. It has its drawbacks. As a method to eliminate this drawback, various attempts have been made to add a retardant to the polyamide before it is molded.
The flame retardants that have been proposed so far do not have a sufficient flame retardant effect on polyamides, and require a large amount of addition in order to exhibit their effect.

Furthermore, addition of such a large amount of flame retardant is accompanied by undesirable phenomena such as significant decomposition, foaming, gelling, and coloring of the polyamide, and the inherent physical properties and commercial value of the polyamide are significantly compromised. For example, even if it is known as a flame retardant, British Patent No. 11
Decabromo biphenyl, decabromo biphenyl ether, etc. described in No. 58163 have poor compatibility with polyamides, poor moldability, and it is difficult to obtain homogeneous molded products. becomes cloudy and becomes so-called dull.

Also, tetrabromo phthalic anhydride, tetrachlorophthalic anhydride, het acid, tetrabromo bisphenol A
When polyamide and the like are mixed together and molded, the resulting molded product becomes extremely colored and loses its commercial value. Furthermore, hexabromobenzene and the like are undesirable from this point of view as they cause significant smoke sublimation during the polyamide molding process. Furthermore, 2,4,6-tribromoacetanilide and the like described in Japanese Patent Publication No. 48-42203 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 poor. This elution phenomenon has undesirable effects, particularly when polyamide is made into fibers, such as fiber breakage during the drawing and warping process. The purpose of the present invention is to provide polyamides without sacrificing their excellent properties.
The object of the present invention is to provide a polyamide composition that has durable flame retardancy and does not have the disadvantages of conventional techniques 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 carboxylic acid compound represented by the following general formula [1] based on the total weight of the polyamide composition. be.

(However, × is chlorine or bromine, A is -○-, 1NH, 1S02-, 1C&- or 1(CH2)2-, R is -C
OO day or -CH3, 1 is an integer of 1 to 4, m is 0 or 1, and n is 0 or an integer of 1 to 2. ) The polyamide used in the present invention refers to ordinary synthetic linear polyamides, such as nylon 6, nylon 10, nylon 11, nylon 12, nylon 66, and nylon 610.
and copolyamides containing these as main components, among which nylon 6 and nylon 66 are particularly preferably applied.

The nuclear halogenated carboxylic acid compound used in the present invention is “
It is represented by the general formula [1].

Examples of such nuclear halogenated carboxylic acid compounds include parafuromphenylacetic acid and orthobromphenylacetic acid.
Metabromphenylacetic acid, parachlorophenylacetic acid, orthochlorophenylacetic acid, metachlorophenylacetic acid, parachlorophenylacetic acid, 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, parabromphenoxyacetic acid , 214-dibromphenoxyacetic acid, 2'4,5-tribromphenoxyacetic acid, parabromphenylglycine, 2,4-dibromphenylglycine, monobromobenzenesulfonylacetic acid, orthomethyl-parabromphenylacetic acid, 3-methyl- 5-chlorophenylglycine, 3-methyl-5-chlorophenoxyacetic acid, 8-fluorinated phenylpropionic acid, y-chlorinated phenylbutyric acid, brominated phenylacetic acid-orthocarboxylic acid, chlorinated phenylacetic acid-orthocarboxylic acid carboxylic acid,
Examples include metabromophenylglycine-orthocarboxylic acid. These compounds themselves are thermally stable and provide excellent flame retardant effects without deteriorating the physical properties of polyamide. Among these, in terms of color tone of polyamide molded products,
A nuclear brominated carboxylic acid compound is preferred, and the number of nuclear substituted halogens is preferably 1 to 2 because the compound itself can be easily produced and a product with high purity can be obtained. Further, from the viewpoint of compound cost, etc., compounds without a nuclear substituted methyl group or carboxyl group are preferred, and for the same reason, nuclear halogenated phenylacetic acid compounds and nuclear halogenated phenoxyacetic acid compounds are preferred. Therefore, particularly preferred compounds are metabromphenyl acetic acid, parabromphenyl acetic acid, parabromphenoxy acetic acid, 2,4-dibrophenoxy acetic acid, and the like. 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 in the range of 0.5 to 25% by weight based on the final polyamide product. You can use it with . In particular, a range of 2 to 10% by weight is preferred, and a particularly preferred range is 2 to 7% by weight. 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 polyamide, for example, the specified polyfamide and the compound are mixed in a rotating drum, or the mixture obtained by mixing the polyamide and the compound in a mixer is mixed using a known extrusion method. It can be melted and molded using a Ruder or a grid-type melting device. 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 generally it is higher than the melting point of the polyamide, with a melting point of 180
A range of 00 or more is desirable. Preferably, the range is the melting point of the polyamide + (10 to 50 qo). The nuclear halogenated carboxylic 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 amenable to fiberization, and can be easily fiberized 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 yarn quality such as strength and elongation, and dyeability, and the compound remains stable even after repeated home washing and dry cleaning. It is advantageous in that it does not elute or fall off, causing no deterioration in flame retardancy and no hygienic problems. 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 "% by weight" unless otherwise specified, and the relative viscosity is determined by dissolving the polyamide to a concentration of 1% in concentrated sulfuric acid and using an Ostwald viscometer at 25o0. The measured values are shown. Flame retardancy was evaluated using the limiting oxygen index (hereinafter referred to as L.0.
1. It is abbreviated as. ) and 450 It is expressed as the number of flames by the coil method. {a} L. 0.1. According to the measurement method JIS-K-7201-1972, L0.1. was measured.

[b-Measuring the number of twists using the 45o coil method A twisted rod weighing 1 hour, having a length of low rib, and number of twists of 10 is made from the fiber to be tested, and this twisted rod is attached to a stainless steel wire on the 0.5 side. Insert into a coil with diameter IQ cape, coil pitch 2 legs, length 15 ribs and hold at a 45 degree angle, flame length 45
The micro burner on the side lights up the lower end for 1 second to cause combustion, and when the flame goes out, the position is shifted and an after-flame is set at the lower end again in the same way.

In this way, the number of saddle flames until the 10 skins of the twisted rod were burned out was measured, and the average value of 5 times is shown.The compatibility test method and evaluation method are as follows. J×2
Approximately 27 minutes of polyamide bright pellets and a predetermined amount of the compound are thoroughly mixed and then poured into a test tube.

To prevent oxidation of the polyamide, the test tube is heated to a temperature 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 molten material was visually observed through the glass wall, and the evaluation was roughly divided into the following three stages. ◯=uniformly dissolved, the polymer was transparent, and there was no yuzu droplet dispersion.

Δ=Most of the polymer is dissolved, but the polymer is translucent due to some dispersion.

× = Polymer is opaque, and a large amount of undissolved matter is dispersed.

However, in the case of being located in the middle of the above three stages, an intermediate display such as ○△ was 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 close to unmodified polyamide o
Δ=Coloring is clearly observed compared to unmodified polyamide.

x = Significant coloring compared to unmodified polyamide.

However, in the case of an intermediate stage, an intermediate display such as △× was used.

Example 1 Nylon 6 chip (relative viscosity 2.60, moisture content 0.08
%), various compounds as listed in Table 1 were thoroughly mixed in advance, and 265q.
Melt spinning was carried out at a temperature of ○ and a print speed of 600 m/min.

Next, it is stretched 3.4 times and made of 10 filaments.
A fiber of 0 denier was obtained.

The flammability of the obtained fibers was tested by L. 0.1. This was done by measuring the number of saddle flares using the 45o coil method. Further, evaluation of weavability was performed as follows.

○ = Less thread breakage, on par with unmodified nylon 6, less than 1 thread breakage per 1 million machines.

△=The thread breaks about 5 to 20 times per million.

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

As an example of the present invention, parabromphenyl acetic acid was used, and for comparison, a similar compound was added thereto in the same amount.

That is, NO. No. 1 is para-bromobenzyl alcohol with an OH group bonded instead of a carboxyl group; No. 2 is parafrom besodylamine-N-acetyl to which an N-acetyl group is bonded. 3 is parabromphenyl acetamide bound to an acid amide. As is clear from the results in Table 1, No. In the case of Nos. 1 to 3, the compatibility, colorability, and spinnability were almost good, but the important flame retardant performance was that of ordinary nylon 6.
It was almost the same as (No. 4).

On the other hand, the product of the present invention using parabromphenyl acetic acid (No.
5) showed very excellent flame retardant performance.

Table 1 Example 2 Nylon 6 chips (relative viscosity 2.70) were coated with compounds known as flame retardants listed in Table 2 and B according to the present invention.
-Para-bromo-phenylpropionic acid, 2-carboxy-4,6-dibromo-phenylacetic acid, para-bromo-phenylglycine and para-bromo-benzenesulfonylacetic acid were thoroughly mixed in advance, and the mixture was heated at 26 mm using an extruder type extruder. A test piece with a width of 6.5 ribs and a length of 150 ribs was cut out from a sheet with a thickness of 3 ribs prepared by melting and mixing the rice bran.

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, resulting in dull molded products and poor moldability. In addition, coloring was observed in all cases, and No. 2 is particularly remarkable. Furthermore, although the flame retardant performance is recognized, it is considerably inferior even though the amount added is twice that of the product of the present invention. No. 3 and no. 5 is
In both cases, coloring was observed and flame retardant properties were observed, but they were considerably inferior to the products of the present invention. No. 4 is coloring,
Due to severe decomposition and deterioration, it was not possible to obtain a molded product. N
o. 6 and no. 7 is a phosphorus compound. In this case, the colorability is good, but the flame retardant performance is not improved at all. In the case of polyester, it is known that flame retardant performance is good if the phosphorus compound contains about 500 phosphorus atoms, but compared to this, the results with nylon 6 are surprising. The difficulty of making nylon 6 flame retardant is similar. No
．． No. 8 is a type of phosphate ester containing a halogen, but its compatibility is insufficient, the coloration is significant, and its flame retardant effect is also insufficient. As mentioned above, when 12% of a compound known as a retardant is added to nylon 6, the compatibility,
Problems such as coloration and decomposition and deterioration occurred.

In order to improve this problem, it is possible to reduce the amount added, but as shown in Table 2, even with 12% addition, the flame retardant performance is insufficient, and it is not possible to reduce the amount added any further. This will further reduce the flame retardant performance, and the meaning of flame retardancy will be lost. On the other hand, No. 10~No. It will be understood that the product of the present invention shown in No. 13 has no problems with compatibility, coloration, etc., and its flame retardant performance is also very excellent.

Example 3 Nylon 6, Fludalchip (relative viscosity 2.60, moisture content 0.08%), compounds known as key combustion agents listed in Table 3, and parabromphenoxyacetic acid and 2-methyl according to the present invention. -4-bromophenyl acetic acid and 2,4,5
- Trichlorophenoxyacetic acid was blended and the threads were melted and removed in the same manner as in Example 1 to evaluate various properties.

No. 1 and no. 2 has concerns about colorability and spinnability,
Furthermore, the flame retardant performance is also insufficient.

No. No. 3 has no particular problems with compatibility, colorability, or spinnability, but white powder, which is thought to be a compound added during stretching, is a guide.
A so-called elution phenomenon in which the yarn adheres to rollers and the like is observed, which is undesirable as it causes thread breakage. Furthermore, 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 is a chlorine compound, but it is not compatible with nylon 6, and yarn breakage occurred frequently during hemming, and the nozzle was clogged and winding was impossible. No. 5 was completely poor. No. No. 6 has good compatibility, colorability, spinnability, etc., but No. A similar phenomenon as in case 3 was observed. Moreover, contrary to expectations, the flame retardant performance did not improve at all. ．． As mentioned above, when nylon 6 is blended with 10% of a compound known as a brood retardant and made into fused paper yarn to obtain fibers, the compatibility, colorability, classability, elution phenomenon during stretching, etc. All of them were satisfactory, and nothing that showed sufficient flame retardant performance was found. On the other hand, No.
The products of the present invention shown in Nos. 9 to 11 do not have the above-mentioned drawbacks, and even with a blending amount of 5%, nylon 6 fibers having excellent flame retardancy were obtained.

Table 3 Example 4 Nylon 6 chips (relative viscosity 2.70) were thoroughly mixed with parabromphenoxyacetic 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, flame retardancy is observed with a blending amount of 0.5% or more, while in terms of compatibility and coloring,
It is preferably 5% or less.

Table 4 Example 5 Nylon 6 full-dull chip (relative viscosity 2.8, moisture content 0)
．． 075%) and 2% by weight of 2,4-dibromphenoxyacetic acid were thoroughly mixed in advance and melt-kneaded at 250°C using an extruder to obtain master chips.

This master chip was thoroughly mixed with a nylon 6 full-dull chip (relative viscosity: 2.80, moisture content: 0.075%) so that the content of 2,4-dibromphenoxyacetic acid was 5.5% by weight, and the mixture was combined into an extruder mold. 25y using a threading machine
Melt spinning was carried out at a temperature of o. Next, stretch it to about 3.3 times and
A 40 denier fiber consisting of 0 filaments was obtained. The strength of this fiber was 4.8 ta'd and the elongation was 35%, which was not much different from that of unmodified nylon 6 ordinary yarn. This fiber was subjected to normal warping and knitting to obtain a tricot sample. Problems such as workability during warping and knitting were particularly surprising as they were the same as in the case 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 bush flames was measured.

As a result, the tricot fabric according to the present invention was exposed to flame five times, and its flame retardancy was excellent. On the other hand, the denatured nylon 6 cloth obtained in the same manner 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 a sheet with a thickness of 3 was molded using the same method as in Example 2, but at a molding temperature of 275 qo. The L. 0.1. was measured.

Compatibility, colorability, etc. were also evaluated. Table 5 No.
．． 1 is a type of phosphoric acid esters containing bromine and chlorine, but this has problems with compatibility and is markedly colored.
Furthermore, even though the amount added is 10%, the flame retardant performance is also insufficient.

On the other hand, No. 3 and no. The product of the present invention shown in No. 4 does not have the above-mentioned problems, and its flame retardant performance is excellent despite the small amount added.

Claims (1)

[Claims] 1. A flame-retardant polyamide composition containing 0.5 to 25% by weight of a nuclear halogenated carboxylic 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, A is -O-, -NH-,
-SO_2-, -CH_2- or -(CH_2)_2
-, R represents -COOH or -CH_3, 1 is 1 to
m is an integer of 4, m is 0 or 1, and n is 0 or an integer of 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 carboxylic acid compound represented by general formula [I], X is bromine. 4 In the nuclear halogenated carboxylic acid compound represented by general formula [I], A is -O
- The flame-retardant polyamide composition according to claim 1 or 3. 5. The flame-retardant polyamide composition according to claim 1 or 3, wherein m is 0 in the nuclear halogenated carboxylic acid compound represented by general formula [I]. 6. The flame-retardant polyamide composition according to claim 1, 3, 4, or 5, wherein n is 0 in the nuclear halogenated carboxylic acid compound represented by general formula [I]. thing. 7 In the nuclear halogenated carboxylic acid compound represented by general formula [I], claims 1, 3, 4, 5, or 1, wherein 1 is an integer of 1 to 2; The flame-retardant polyamide composition according to item 6. 8 The nuclear halogenated carboxylic acid compound represented by general formula [I] is selected from the group consisting of meta-bromphenyl acetic acid, para-bromphenyl acetic acid, para-bromphenoxyacetic acid, and 2,4-dibromphenoxyacetic acid. The flame-retardant polyamide composition according to claim 1 or 3, which is at least one compound comprising: 9 The content of the nuclear halogenated carboxylic acid compound represented by general formula [I] with respect to the total weight of the polyamide composition is 2 to 1
The flame-retardant polyamide composition according to claim 1, which has a content of 0% by weight.