KR20010041746A - Light and thermally stable polyamide - Google Patents

Abstract

The photo-stable and thermostable polyamides with internal stabilizers may be prepared in the presence of an effective amount of at least one hindered piperidine compound and an effective amount of at least one aliphatic dicarboxylic acid chain control compound. Prepared by polymerization.

Description

Light and Thermally Stable Polyamide

The present invention relates to polyamides having high photostability and thermal stability. More specifically, the present invention relates to modified nylon polymers containing sterically hindered piperidine compounds and chain modifiers, wherein the modified nylon polymers have improved light and thermal stability.

It is known that when unmodified nylon is exposed to light and / or heat, it discolors and loses its physical properties such as strength retention and stretch resistance. Thus, adding light stability and / or thermal stability to nylon is essential in many cases to give nylon acceptable performance. Stabilizers may be added before, during or after the polymerization. Conventional stabilizers are added to the polymer and mixed, and are not bound to the polymer chains. Thus, stabilizers can be readily implemented, evaporated or washed out of the polymer during processing or use of the polyamide. This means that the stabilizing activity is reduced in an undesirable manner and impurities are released to the surroundings (eg, air, dye baths, etc.).

It is known to use various organic stabilizers in nylon and articles made therefrom. However, the problem is that organic stabilizers, such as hindered phenols, are expensive and have limited effects.

In general, inorganic stabilizers are less expensive and more effective than organic stabilizers, but inorganic stabilizers have other problems. Typically inorganic stabilizers, such as copper compounds, cause problems during processing. For example, the copper compound may be reduced to an insoluble copper element during melt extrusion. The production of elemental copper reduces production efficiency and costs significant device maintenance. In addition, the removal of copper deposits results in environmentally undesirable wastewater. In other processes, such as treating automotive nylon fibers with copper complexes in a dye bath, excess copper complexes remaining in the dye bath also produce environmentally undesirable wastewater.

Applicant's U.S. Application No. 08 / 804,312 discloses a molding product of poly (epsilon-caprolactam) hydrolysically polymerized in the presence of water and sterically hindered piperidine derivatives in a dyeing bath and in the dyeing bath. A method of making a photochemically stable dyed nylon composition comprising dyeing at least one metallic or non-metallic acid dye.

Applicant's U.S. Application No. 60 / 045,269 discloses stabilized solution-dyeing, which melts a polymerized amide monomer-comprising polyamide in the presence of one or more hindered piperidine compounds and colors the molten polyamide with a colorant. It relates to a method for producing a fiber.

PCT Applicant International Application No. PCT / EP 95/01349 contains one or more triacetone diamine compounds having a primary amino group (-NH ₂ ) which reacts with the carboxy end groups of the polyamide molecule during the polymerization reaction so that the polymer is light stable. And essentially stable polyamides with thermal stability are described.

Poly. Deg. And Stab. 21, 251-262 (1988) discloses improving the light stability of polyamide 6/6 by adding 2,2,6,6-tetramethylpiperidin-4-ol (TMP). The authors claim that TMP reacts with the carboxyl end groups of the polyamide when recondensing the TMP-containing polyamide 6/6 melt at 275 ° C. under a steam atmosphere.

Accordingly, there is a need for a modified polyamide that reduces the need for copper-based stabilizers and that does not discolor, i.e., yellow after exposure to light and / or heat. There is also a need for the production of polyamides having improved yellowing resistance properties upon exposure to light and / or heat, especially in engineering plastic products.

It is an object of the present invention to provide modified polyamides which do not discolor after exposure to light and / or heat.

Another object of the present invention is to reduce the need for copper-based stabilizers in polyamides.

It is a further object of the present invention to provide a process for the preparation of environment-friendly and effective modified polyamides having both photostability and thermal stability.

Thus, according to one embodiment of the present invention, there is provided a process for preparing light stable and thermo stable polyamides with built-in stabilizers. The method comprises polymerizing at least one polyamide-forming monomer in the presence of an effective amount of at least one hindered piperidine compound and an effective amount of at least one aliphatic dicarboxylic acid chain control compound.

In another aspect, the present invention includes a polymer backbone, at least one hindered piperidine radical and at least one aliphatic dicarboxylic acid chain control compound, wherein the at least one hindered piperidine radical And at least one aliphatic dicarboxylic acid chain control compound are directed to photostable and thermostable polyamides that are chemically bonded to the polymer backbone. The polyamides of the present invention are substantially free of copper compounds.

Modified polyamides with internal stabilizers made in accordance with the present invention obtain good photostability and thermal stability without the use of other stabilizers such as copper salts. The use of at least one aliphatic dicarboxylic acid chain control compound and at least one sterically hindered piperidine compound not only acts as a molecular weight modifier in the polymerization reaction, but also imparts photostability and thermal stability to the resulting polyamide. The modified polyamides of the present invention do not discolor in the early stages upon exposure to ultraviolet light.

The above and other objects, effects, characteristics and advantages of the present invention will become more apparent in the following detailed description of preferred embodiments of the present invention, especially when taken in conjunction with the drawings.

1 is a graph showing strength retention for solution-dyed yarns after exposure to a weatherometer.

2 is a graph showing the degree of yellowing of polyamide plaques after exposure to weathering testers.

To help understand the principles of the invention, a description of specific embodiments of the invention is set forth below, and specific terminology is used to describe it. Nevertheless, use of this specific terminology will not limit the scope of the invention, and variations, modifications, equivalents, and additional applications of the principles of the invention discussed as would normally be practiced in the art to which this invention pertains may be considered. There will be.

As used herein, the term "polyamide" refers to homopolymers, copolymers, blends and grafts of these long chain polymers having repeating amide groups (-CO-NH-) as part integrated into the polymer backbone. These long chain polyamides are generally referred to as "nylons".

The term "inner" as used in connection with the polyamide of the present invention means that the component that provides the light stability and thermal stability to the polyamide is chemically bonded to the polymer backbone of the polyamide, rather than simply physically mixed with the polyamide. do.

In one embodiment, the invention comprises a polymer backbone, at least one hindered piperidine radical and at least one aliphatic dicarboxylic acid chain control compound, wherein the at least one hindered piperidine radical And at least one aliphatic dicarboxylic acid chain control compound are chemically bonded to the polymer backbone and provide a modified polyamide that is substantially free of copper compounds. The light stable and thermostable polyamides of the present invention are nylon 6, nylon 6/6, nylon 6/9, nylon 6/10, nylon 6T, nylon 6/12, nylon 4/6, nylon 11, nylon 12, or poly Aromatic nylons such as (meth-phenylene isophthalamide) and poly (para-phenylene terephthalamide). As the light stable and heat stable polyamide of the present invention, nylon 6, nylon 6/6, nylon 6T, nylon 6/12 and nylon 4/6 are preferred. Nylon 6 is most preferred as the light stable and heat stable polyamide of the present invention.

Any suitable polyamide-forming monomer can be used for making the photostable and thermostable polyamides of the present invention. Suitable polyamide-forming monomers include, but are not limited to, diamine compounds, dicarboxylic acids, caprolactam monomers, and combinations thereof. In a preferred embodiment of the invention, the polyamide-forming monomers consist of caprolactam monomers.

The polymerization reaction to form the polyamides of the present invention is preferably carried out according to conventional methods, such as those described in US Pat. No. 5,149,758 to Matthies, the entire contents of which are incorporated herein by reference, The polymerization is carried out in the presence of an effective amount of at least one hindered piperidine compound and an effective amount of at least one aliphatic dicarboxylic acid chain control compound. An effective amount of the at least one hindered piperidine compound is an amount sufficient to provide photostability and thermal stability to the resulting polyamide in combination with at least one aliphatic dicarboxylic acid chain control compound. The effective amount of the at least one hindered piperidine compound is preferably from about 0.030 to about 0.800 mol%, more preferably from about 0.060 to about 0.400 mol%, based on the weight of the polyamide-forming monomer used. An effective amount of at least one aliphatic dicarboxylic acid chain control compound is an amount sufficient to provide photostability and thermal stability to the resulting polyamide in combination with at least one sterically hindered piperidine compound. The effective amount of at least one aliphatic dicarboxylic acid chain control compound is preferably from about 0.001 to about 0.800 mol%, more preferably from about 0.050 to about 0.500 mol%, based on the weight of the polyamide-forming monomer used.

To prepare the polyamides of the present invention, at least one hindered amine compound and at least one aliphatic dicarboxylic acid chain control compound are added to the starting monomer or polymerization mixture. That is, one or more hindered piperidine compounds, one or more aliphatic dicarboxylic acid chain control compounds and polyamide-forming monomers are added separately or in a mixture to the reactor in which the polymerization takes place.

The hindered piperidine compound used in the present invention is

It is expressed as Wherein R ₁ comprises an amine- or amide-forming functional group, R ₂ is alkyl, R ₃ is hydrogen, a C ₁ -C ₃ alkyl group and -OR ₄ , wherein R ₄ is hydrogen, methyl and C Selected from the group consisting of ₁ -C ₇ alkyl groups. R ₁ is preferably -NHR ₅ , wherein R ₅ is hydrogen or C ₁ -C ₈ alkyl, carboxyl, carboxylic acid derivative,-(CH ₂ ) _x (NH) R ₅ , wherein x is an integer from 1 to about 6),-(CH ₂ ) _y COOH, wherein y is an integer from 1 to about 6, and-(CH ₂ ) _y COOH acid derivative. The hindered piperidine compound used in the present invention is preferably amino polyalkylpiperidine or polyalkylpiperidine acid. Examples of such steric hindered piperidine compounds

4-amino-2,2,6,6-tetramethylpiperidine,

4- (aminoalkyl) -2,2,6,6-tetramethylpiperidine,

4- (aminoaryl) -2,2,6,6-tetramethylpiperidine,

4- (aminoaryl / alkyl) -2,2,6,6-tetramethylpiperidine,

3-amino-2,2,6,6-tetramethylpiperidine,

3- (aminoalkyl) -2,2,6,6-tetramethylpiperidine,

3- (aminoaryl) -2,2,6,6-tetramethylpiperidine,

3- (aminoaryl / alkyl) -2,2,6,6-tetramethylpiperidine,

2,2,6,6-tetramethyl-4-piperidinecarboxylic acid,

2,2,6,6-tetramethyl-4-piperidinealkylcarboxylic acid,

2,2,6,6-tetramethyl-4-piperidinearylcarboxylic acid,

2,2,6,6-tetramethyl-4-piperidinealkyl / arylcarboxylic acid,

2,2,6,6-tetramethyl-3-piperidinecarboxylic acid,

2,2,6,6-tetramethyl-3-piperidinealkylcarboxylic acid,

2,2,6,6-tetramethyl-3-piperidinearylcarboxylic acid and

2,2,6,6-tetramethyl-3,4-piperidinealkyl / arylcarboxylic acid

Include, but are not limited to.

The hindered amine compound may be a mixture of hindered piperidine compounds. More preferably, the hindered piperidine compound is 2,2,6,6-tetraalkylpiperidine. Most preferably, the hindered piperidine compound is 4-amino-2,2,6,6-tetramethylpiperidine.

Chain control compounds suitable for use in the present invention are aliphatic dicarboxylic acids and combinations thereof. Examples of such aliphatic dicarboxylic acids include malic acid, malonic acid, methylmalonic acid, ethylmalonic acid, butylmalonic acid, dimethylmalonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2- Ethyl-2-methylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, 2,3-dimethylglutaric acid, 2,4-dimethylglutaric acid, adipic acid, 3-methyladipic acid, azela Acids, pimelic acid, sebacic acid, decanedicarboxylic acid and dodecanedioic acid, but are not limited to these.

The aliphatic dicarboxylic acid chain control compound used in the present invention may be the same or different from the dicarboxylic acid used as the polyamide-forming compound. The aliphatic dicarboxylic acid chain control compound is preferably selected from the group consisting of C ₄ -C ₁₀ alkane dicarboxylic acids, in particular adipic acid, azelaic acid, sebacic acid and decandicarboxylic acid. Most preferably, the aliphatic dicarboxylic acid chain control compound is adipic acid.

Of course, various additives other than stabilizers may be used in the modified polyamides of the present invention. These include, for example, but are not limited to, lubricants, nucleating agents, antioxidants, antistatic agents and the like.

The present invention provides modified polyamides that are stable from degradation by light and heat and that do not discolor, i.e. yellow, upon exposure to light and / or heat. In the present invention, other stabilizers may be present in some cases, but it is not necessary to use other stabilizers as additives, such as copper compounds. If such other stabilizers are present, they are present in significantly smaller amounts. By not using these stabilizers, the cost of maintaining the device is reduced, and the harmful waste water produced upon removal of the stabilizer deposits is reduced.

The present invention also provides modified polyamides with increased spinning efficiency. Spinning efficiency is increased by about 0.5% or more. This increase in spinning efficiency reduces the annual manufacturing costs by hundreds of thousands of dollars. Without being limited to this, the increased spinning efficiency is currently understood to be because the modified polyamides of the present invention have a narrower molecular weight distribution than acetic acid- and propionic acid-regulated polyamides. For polyamides with a relative viscosity of 2.7, the molecular weight distribution of the modified polyamides of the present invention is about 1.65 to about 1.80, and the molecular weight distributions of the acetic acid- and propionic acid-regulated polyamides are about 1.90 to about 2.00.

The present invention further relates to articles made from the photostable and thermostable polyamides of the invention and to methods of making such articles. Examples of such products include, but are not limited to, fibers, yarns, carpets, engineering plastics (eg, automotive parts), and the like. Fibers can be used to incorporate the photostable and thermostable polyamides of the present invention into US Pat. Nos. 4,983,448 and Kent of Karageorgiou, the entire contents of which are incorporated herein by any conventional fiber-making method, such as designation. (Kent) et al., 5,487,860. Preferably, the fiber-making method comprises high speed spinning of light stable and thermostable polyamides at a starting speed of about 4,000 m / min. Engineering plastics incorporate the photostable and thermostable polyamides of the present invention in any conventional plastics-making method, such as US Pat. No. 5,474,853 to Watanabe et al., The disclosure of which is incorporated herein by reference in its entirety. It can be prepared through.

Fibers made from the light stable and thermostable polyamides of the present invention can be dyed by conventional methods used for nylon dyeing, such as metallic and nonmetallic acid dyeing methods. Normal dye bath conditions for nylon dyeing can be used. The following general conditions are exemplary and not intended to be limiting. The dye bath is provided in a volume equal to about 20 times the weight of the product to be dyed. Processing chemicals are added that include chelating agents, leveling agents and acid donors that slowly lower the pH of the dyeing bath in the case of metallic acid dyeing to prevent the deposition or complexing of metal ions in hard water. Dye is added and the pH of the dye bath is adjusted. The solution is heated to the desired temperature, typically about 95 to about 110 ° C., at a rate of about 0.5 to about 3.0 ° C./minute and held at that temperature for about 30 to about 60 minutes. Cool or empty the dye bath and rinse the product thoroughly with fresh water. The dyed product is dried in an oven such as a tumble dryer or tenter oven.

Alternatively, fibers made from the light stable and thermostable polyamides of the present invention may be solution-dyed prior to making into articles. Normal conditions for nylon solution-dyeing may be used. The following general conditions are exemplary and not intended to be limiting. The polyamide of the present invention is melted and colored with a colorant selected from the group consisting of pigments, dyes, pigments and any coloring compound having intermediate properties of dyes and combinations thereof. The colored polyamides are then spun into fibers or fabrics, for example, via the methods disclosed in Carrageorgio, US Pat. No. 4,983,448, Kent et al., US 5,487,860, and Spich, US Pat. No. 4,918,947. In the case of engineering plastics, the polymer chips are mixed with coloring compounds such as pigments and dyes before filling the extruder. Mixing before filling the extruder is not physical mixing but physical mixing.

The invention will be further described by way of the examples described in detail below. The embodiment is described by way of example, which does not limit the scope of the invention. In the examples, "ADA" means adipic acid, "PPA" means propionic acid, "TPA" means terephthalic acid, and "TAD" means 4-amino-2,2,6,6-tetra Mean methylpiperidine. In addition, the following terms and test conditions used in the examples are defined as follows.

<weight%>

The percentage by weight of the ingredient in question.

<Relative Viscosity (RV)>

Relative viscosity is a comparison of the viscosity of the polymer solution in formic acid with the viscosity of formic acid itself (ASTM D 789). Test results reported herein were obtained using 0.20 g of Nylon 6 dissolved in 20 cc of formic acid at 25 ° C.

<Terminal content>

The amino end group content was determined by dissolving about 2.0 g of the polymer in about 60 cc of the phenol-methanol mixture (68:32). This solution was titrated with about 0.20 N HCl at about 25 ° C. using a potentiometric method to determine the end point with a rapid potential increase.

The carboxy end group content was determined by dissolving about 0.30 g of the polymer in about 40 cc of benzyl alcohol mixture at 180 ° C. This solution was titrated with about 0.03 N t -butyl ammonium hydroxide at about 80 to about 100 ° C. using a potentiometric method to determine the end point with a rapid potential increase.

<Exposure test>

This test is designed to simulate the interior of a car surrounded by extreme environments caused by sunlight, heat and humidity for the purpose of predicting the performance of the car interior. This test measured the degree of yellowing (delta b ^* value) of each exposed sample. This test was performed according to the GM SAE J1885 test method entitled "Accelerated Exposure of Automotive Interior Trim Components using a Controlled Irradiation Water-Cooled Xenon-Arc Apparatus".

<Strength retention rate>

This test was designed to determine the strength retention of control and experimental samples. The term "strength retention" refers to the change in tenacity of a material as a result of exposure of the material to sunlight or an artificial light source. Toughness is a measure of fiber strength. This test was performed according to AATCC Test Method 16-1993, Colorfastness to Light, Option E (Water-Cooled Xenon-Arc Lamp, Continuous Light). The toughness of each material was measured before exposure and after exposure by 425 kJ each time. Strength retention was calculated | required as follows.

<Example 1 (Comparative Example): Polymerization of PPA / TAD-Controlled Nylon 6>

A 250-liter autoclave with a mixture of 75 kg of caprolactam, 1800 g of water, 135 g (0.18% by weight) propionic acid and 112.5 g (0.15% by weight) of 4-amino-2,2,6,6-tetramethylpiperidine Was charged. The mixture was heated to 270 ° C. for 1 hour while increasing the pressure to 60 psi (3102 mm Hg). The mixture was held at 60 psi for 30 minutes, then the pressure was slowly lowered. To accelerate the polymerization, the reaction system was placed under reduced pressure of 400 mm Hg for 75 minutes. The polymer was then extruded under nitrogen pressure and cut into chips. The chips were washed with hot water (90 ° C.) and dried in a tumble dryer. Relative viscosity was measured to be 2.71. The amino group content was measured at 42 meq / kg and the carboxyl end group content was measured at 45 meq / kg.

Example 2 Polymerization of ADA / TAD-Controlled Nylon 6

250-liter mixture of 75 kg caprolactam, 1800 g water, 240 g adipic acid (0.32 wt%) and 112.5 g (0.15 wt%) of 4-amino-2,2,6,6-tetramethylpiperidine The autoclave was charged. The mixture was heated to 270 ° C. for 1 hour while increasing the pressure to 60 psi (3102 mm Hg). The mixture was held at 60 psi for 30 minutes, then the pressure was slowly lowered. To accelerate the polymerization, the reaction system was placed under reduced pressure of 500 mm Hg for 45 minutes. The polymer was then extruded under nitrogen pressure and cut into chips. The chips were washed with hot water (90 ° C.) and dried in a tumble dryer. Relative viscosity was measured to be 2.67. The amino group content was measured at 37 meq / kg and the carboxyl end group content was measured at 70 meq / kg.

Example 3 (Comparative): Polymerization of PPA / 0.15% TAD-Regulated Nylon 6>

A mixture of molten caprolactam containing 0.5 wt% water and 0.19 wt% propionic acid was continuously injected into the top of the polymerization reactor. The polymerization reactor used was the stainless steel VK column mentioned in US Pat. No. 4,354,020, which is incorporated herein by reference. The mixture was continuously injected at the top of the VK column into reaction zone I at a rate of about 30-40 kg / h at about 265 ° C. with stirring. A 340 liter capacity VK column was heated with heat exchange oil. At the same time, separate 4-amino-2,2,6,6-tetramethylpiperidine at a rate such that 4-amino-2,2,6,6-tetramethylpiperidine in the mixture is always 0.15% by weight. It was fed continuously into the reaction zone I from a stream of. The heat of polymerization generated in the other reaction zone was removed by appropriate cooling with an internal heat exchanger. The temperature of the last reaction zone was about 265 ° C. The resulting polymer was extruded at the bottom of the VK column and cut into chips. The chips were washed with hot water (90 ° C.) and dried in a tumble dryer. Relative viscosity was determined to be 2.68. Both the amino group content and the carboxyl end group content were measured at 44 meq / kg.

Example 4 Polymerization of ADA / 0.15% TAD-Controlled Nylon 6

Caprolactam was polymerized on the same VK column as Example 3, but 0.29 wt% adipic acid, 0.5 wt% water and 0.15 wt% of 4-amino-2,2,6,6-tetramethylpiperidine were added. It was different. The dry product had a relative viscosity of 2.73, an amino end group content of 43 meq / kg, and a carboxyl end group content of 59 meq / kg.

Example 5 Polymerization of ADA / 0.30% TAD-Controlled Nylon 6

Caprolactam was polymerized on the same VK column as Example 3, but 0.29 wt% adipic acid, 0.5 wt% water and 0.30 wt% 4-amino-2,2,6,6-tetramethylpiperidine were added. It was different. The dry product had a relative viscosity of 2.70, an amino end group content of 53 meq / kg, and a carboxyl end group content of 51 meq / kg.

Example 6 (Comparative): Polymerization of TPA / 0.15% TAD-Controlled Nylon 6>

Caprolactam was polymerized on the same VK column as in Example 3, except that 0.30 wt% terephthalic acid, 0.5 wt% water and 0.15 wt% 4-amino-2,2,6,6-tetramethylpiperidine were added. The dry product had a relative viscosity of 2.68, an amino end group content of 42 meq / kg, and a carboxyl end group content of 63 meq / kg.

Example 7 Spinning of 1115 Denier / 58 Filament Solution-Stained Yarns of Tri-Global Cross Sections

In addition to nylon 6 polymers from Examples 3-6, commercially available nylon 6 (Ultramid B® Nylon 6, available from BASF Corporation of Mount Olive, NJ) at 260-265 ° C. I was. The blue-grey concentrate mixed with the appropriate amount of nylon chips was added to the spinning machine via a volumetric feeder. The extruded filaments were cooled and solidified through a cooling air stream at 15 ° C. After spinning, the yarn was pulled to an elongation of 3.3 and woven in a woven jet at 215 ° C. The yarn was obtained at a draw roll speed of about 2350 m / min.

<Example 8: Strength retention after UV exposure>

The solution-dyed blue-gray yarn from Example 7 was 425 kJ in an Atlas Ci65 Weather-Ometer® under the conditions detailed in AATCC Test Method 16-1993, Colorfastness to Light, Option E. Incremental exposure to 2125 kJ. The strength of each yarn was measured before and after exposure with increasing 425 kJ each time. The strength retention after each increase and exposure is shown in FIG. 1. This result shows that the strength retention of TAD-containing polymers, in particular ADA / TAD polymers, is significantly increased. Commercially available nylon 6 had a dramatic decrease in strength after exposure, while TAD-containing polymers retained strengths greater than 85% even after exposure to 2125 kJ.

<Example 9: Yellowing test of plate according to GM SAE J1885 test method>

In addition to the polymers from Examples 3-6, commercially available nylon 6 (Ultramid B® Nylon 6, available from BASF Corporation of Mount Olive, NJ) was melted in an injection molding machine at about 265 ° C. The molten polymer was injected into a mold to make a plate of 110 mm x 110 mm x 3 mm. These plates were then cut into smaller plates, each about 55 mm x 110 mm x 3 mm.

The plates were then exposed for 1,000 hours (1,410 kJ) in 100 hour increments (141 kJ) on an Atlas CI65 Weather-Ommeter® under the conditions detailed in the GM SAE J1885 test method. Measure the degree of yellowing (or “delta b ^* ”, after which the exposed plate is increased each time using the Applied Color System spectrometer (or “delta b ^* ”, indicating that the higher the delta b ^* value, the more yellow the sample is). It was. The exposure results are shown in FIG. The results show that the commercially available nylon 6 polymer and the comparative TPA / 0.15% TAD-regulated polymers were most significantly yellowed during the exposure process. The PPA / TAD polymer was less yellowed than the commercial nylon 6 polymer and the comparative TPA / 0.15% TAD-controlled polymer, while the ADA / TAD polymer was only slightly yellowed upon exposure.

While the invention has been described in terms of the most practical and preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments and on the contrary there are various modifications and equivalents that fall within the spirit and scope of the appended claims.

Claims (22)

Polymerizing at least one polyamide-forming monomer in the presence of an effective amount of at least one hindered piperidine compound and an effective amount of at least one chain control compound, wherein the at least one chain control compound A process for producing a photo-stable and thermostable polyamide comprising aliphatic dicarboxylic acids and combinations thereof. The method of claim 1, wherein the at least one hindered piperidine compound is selected from the group consisting of amino polyalkylpiperidines. The compound of claim 1, wherein the at least one sterically hindered piperidine compound is 4-amino-2,2,6,6-tetramethylpiperidine, 4- (aminoalkyl) -2,2,6,6- Tetramethylpiperidine, 4- (aminoaryl) -2,2,6,6-tetramethylpiperidine, 4- (aminoaryl / alkyl) -2,2,6,6-tetramethylpiperidine, 3-amino-2,2,6,6-tetramethylpiperidine, 3- (aminoalkyl) -2,2,6,6-tetramethylpiperidine, 3- (aminoaryl) -2,2, 6,6-tetramethylpiperidine, 3- (aminoaryl / alkyl) -2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethyl-4-piperidinecar Acids, 2,2,6,6-tetramethyl-4-piperidinealkylcarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinearylcarboxylic acid, 2,2,6 , 6-tetramethyl-4-piperidinealkyl / arylcarboxylic acid, 2,2,6,6-tetramethyl-3-piperidinecarboxylic acid, 2,2,6,6-tetramethyl-3 -Piperidinealkylcarboxylic acid, 2,2,6,6-tetramethyl-3-piperidinearylcarboxylic acid, 2,2,6,6-tetramethyl-3,4-piperidineal The method / arylcarboxylic acids and is selected from the group consisting of a combination thereof. 4. The method of claim 3, wherein the at least one hindered piperidine compound is 4-amino-2,2,6,6-tetramethylpiperidine. The compound of claim 1, wherein the at least one aliphatic dicarboxylic acid chain control compound is malic acid, malonic acid, methylmalonic acid, ethylmalonic acid, butylmalonic acid, dimethylmalonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid. , 2,3-dimethylsuccinic acid, 2-ethyl-2-methylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, 2,3-dimethylglutaric acid, 2,4-dimethylglutaric acid, adipic Acid, 3-methyladipic acid, azelaic acid, pimelic acid, sebacic acid, decandicarboxylic acid, dodecanedioic acid, and combinations thereof. The method of claim 5, wherein the at least one aliphatic dicarboxylic acid chain control compound is selected from the group consisting of adipic acid, azelaic acid, decandicarboxylic acid, sebacic acid, and combinations thereof. The method of claim 6, wherein the at least one aliphatic dicarboxylic acid chain control compound is adipic acid. The method of claim 1, wherein the light and heat stable polyamides are nylon 6, nylon 6/6, nylon 6/9, nylon 6/10, nylon 6T, nylon 6/12, nylon 4/6, nylon 11, nylon 12 , Poly (meth-phenylene isophthalamide) and poly (para-phenylene terephthalamide). The method of claim 8, wherein the light stable and heat stable polyamide is nylon 6. 10. The method of claim 1, wherein the polyamide-forming monomer comprises a caprolactam monomer. A polymer backbone, at least one hindered piperidine radical and at least one aliphatic dicarboxylic acid chain control compound, wherein the at least one hindered piperidine radical and at least one aliphatic dicarboxyl Acid-stable regulatory compounds are photostable and thermostable polyamides that are chemically bonded to the polymer backbone. 12. The polyamide according to claim 11, wherein the at least one hindered piperidine compound is selected from the group consisting of amino polyalkylpiperidines. 12. The method of claim 11, wherein the at least one hindered piperidine compound is 4-amino-2,2,6,6-tetramethylpiperidine, 4- (aminoalkyl) -2,2,6,6- Tetramethylpiperidine, 4- (aminoaryl) -2,2,6,6-tetramethylpiperidine, 4- (aminoaryl / alkyl) -2,2,6,6-tetramethylpiperidine, 3-amino-2,2,6,6-tetramethylpiperidine, 3- (aminoalkyl) -2,2,6,6-tetramethylpiperidine, 3- (aminoaryl) -2,2, 6,6-tetramethylpiperidine, 3- (aminoaryl / alkyl) -2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethyl-4-piperidinecar Acids, 2,2,6,6-tetramethyl-4-piperidinealkylcarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinearylcarboxylic acid, 2,2,6 , 6-tetramethyl-4-piperidinealkyl / arylcarboxylic acid, 2,2,6,6-tetramethyl-3-piperidinecarboxylic acid, 2,2,6,6-tetramethyl-3 -Piperidinealkylcarboxylic acid, 2,2,6,6-tetramethyl-3-piperidinearylcarboxylic acid, 2,2,6,6-tetramethyl-3,4-piperidineal / Arylcarboxylic acid and a polyamide selected from the group consisting of a combination thereof. The polyamide of claim 13, wherein the at least one hindered piperidine compound is 4-amino-2,2,6,6-tetramethylpiperidine. The method of claim 11, wherein the at least one aliphatic dicarboxylic acid chain control compound is malic acid, malonic acid, methylmalonic acid, ethylmalonic acid, butylmalonic acid, dimethylmalonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid , 2,3-dimethylsuccinic acid, 2-ethyl-2-methylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, 2,3-dimethylglutaric acid, 2,4-dimethylglutaric acid, adipic Polyamides selected from the group consisting of acids, 3-methyladipic acid, azelaic acid, pimelic acid, sebacic acid, decandicarboxylic acid, dodecanedioic acid, and combinations thereof. 16. The polyamide of claim 15, wherein the at least one aliphatic dicarboxylic acid chain control compound is selected from the group consisting of adipic acid, azelaic acid, decandicarboxylic acid, sebacic acid, and combinations thereof. 17. The polyamide of claim 16, wherein the at least one aliphatic dicarboxylic acid chain control compound is adipic acid. The method of claim 11, wherein the polyamide is nylon 6, nylon 6/6, nylon 6/9, nylon 6/10, nylon 6T, nylon 6/12, nylon 4/6, nylon 11, nylon 12, poly (meth- Phenylene isophthalamide) and poly (para-phenylene terephthalamide). 19. The polyamide of claim 18, wherein the polyamide is nylon 6. Photostability comprising a polymer backbone, at least one sterically hindered piperidine radical chemically bonded to the polymer backbone, and at least one aliphatic dicarboxylic acid chain control compound chemically bound to the polymer backbone and having an increased radiation efficiency of at least 0.5% And thermostable polyamides. An article comprising the light stable and heat stable polyamide of claim 11. 22. The article of claim 21 selected from the group consisting of fibers, yarns, carpets and engineering plastics.