JPH0251940B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyamide molded article having light resistance. More specifically, the present invention relates to a polyamide molded body comprising zeolite solid particles that retain copper ions, a vehicle, and polyamide. It has been known for a long time that copper has an effect on the heat oxidation resistance and light oxidation resistance of polyamide. As a method for improving the heat resistance and light resistance of polyamide by adding a small amount of copper compound to polyamide, French Patent No. 906893 and British Patent
652947, German Patent No. 883644, etc. However, copper compounds alone cannot produce satisfactory effects, and at the same time have the disadvantage that metallic copper precipitates even when added in small amounts during melt processing such as spinning and molding. Therefore, in order to enhance the stabilizing effect of copper compounds, Japanese Patent Publication No. 10956/1983
A method of using iodine or an iodine compound in combination with a copper compound as proposed in Japanese Patent Publication No. 48-7700, or a method of using a mercapto compound in combination as proposed in Japanese Patent Publication No. 49-10987 and Japanese Patent Publication No. 49-28661. We know how to do it. The former method has a high stabilizing effect on the copper compound in the polyamide, but has the following drawbacks. For example, when using iodine or metal iodides, the metal will corrode significantly in the presence of water, so special processing is applied to the inside of containers, piping, and polymerization reaction containers used to store and supply iodine to prevent corrosion caused by iodine. There is a complication in the equipment that must be prevented.
Furthermore, nuclear-substituted aromatic iodine compounds and iodine-substituted aliphatic hydrocarbons are themselves unstable compounds, making it difficult to use them industrially. In the latter method, the polyamide has high heat resistance and light resistance in terms of strength retention, but has the disadvantage of coloring during spinning and molding. The present inventors have completed the present invention as a result of intensive research to improve the above-mentioned drawbacks. An object of the present invention is to provide a light-resistant polyamide molded article, and more specifically, to provide a light-resistant polyamide molded article containing a vehicle and zeolite-based solid particles that retain copper ions. be. That is, the present invention consists of zeolite solid particles holding copper ions, a vehicle, and polyamide, and the content of the zeolite solid particles is 0.005 to 0.005.
At 10% by weight, the content of copper ions retained in the zeolite solid particles is 0.001% relative to the entire molded body.
This is a polyamide molded article having light resistance characterized by a content of ~0.5% by weight. In the present invention, the zeolite-based solid particles holding copper ions are those obtained by treating the ion-exchangeable portion of natural or synthetic zeolite made of aluminosilicate with a solution of water-soluble copper salts to remove copper ions. It is something that is kept. copper ion is
There are Cu ⁺ and Cu, and either one is fine, but Cu is more advantageous because it is stable as an ion and easily soluble in water. Alternatively, a complex ion such as Cu[NH ₃ ] ₄ may be used. Zeolite is generally an aluminosilicate with a three-dimensionally developed skeleton structure, and is generally based on Al ₂ O ₃ , XM _2/o O・Al ₂ O ₃・
It is expressed as YSiO ₂・ZH ₂ O. M represents an ion-exchangeable metal ion, usually a monovalent to divalent metal, and n corresponds to this valence. on the other hand,
X and Y are the coefficients of metal oxide and silica, respectively, and Z
represents the number of water of crystallization. Many types of zeolites are known, with different composition ratios, pore diameters, specific surface areas, etc. However, the specific surface area of the zeolite solid particles used in the present invention is 150 m ² /g (based on anhydrous zeolite).
Above, the zeolite constituent SiO ₂ /
The Al ₂ O ₃ molar ratio should be less than 14, preferably less than 11. The water-soluble copper salt solution used easily undergoes ion exchange with the zeolite defined in the present invention, so it is possible to utilize this phenomenon to retain copper ions in the zeolite stationary phase. but,
Zeolite particles that hold metal ions are
Two conditions must be met: the specific surface area is 150 m ² /g or more and the SiO ₂ /Al ₂ O ₃ molar ratio is 14 or less. It has been found that if this is not the case, an effective lightfast object cannot be obtained. This is thought to be due to the fact that the absolute amount of copper ions fixed in zeolite is insufficient in a state where the effect can be exerted. In other words, this is thought to be due to the physicochemical properties of the zeolite, such as the amount of exchange groups, exchange rate, and accessibility. Therefore, zeolites with a high SiO ₂ /Al ₂ O ₃ molar ratio, known as molecular sieves, are completely unsuitable for the present invention. Also, SiO ₂ /Al ₂ O ₃
Zeolites with a molar ratio of 14 or less can hold copper ions uniformly, and it has therefore been found that by using such zeolites, a sufficient light resistance effect can be obtained for the first time. In addition, the SiO ₂ /Al ₂ O ₃ molar ratio of zeolite is 14
The acid resistance and alkali resistance of zeolite with a high silica ratio exceeding 20% increase with increasing SiO ₂ , but on the other hand, it takes a long time to synthesize it, and from an economic standpoint, it is not advisable to use zeolite with such a high silica ratio. Not. The aforementioned natural or synthetic zeolite with SiO ₂ /Al ₂ O ₃ ≦14 can be used satisfactorily from the viewpoint of acid resistance and alkali resistance in the fields in which the present polyamide composition is usually considered, and is also economical. It is cheap and a good idea. From this point of view as well, the SiO ₂ /Al ₂ O ₃ molar ratio must be 14 or less. As the zeolite material having a SiO ₂ /Al ₂ O ₃ molar ratio of 14 or less used in the present invention, either natural or synthetic zeolite can be used. For example, natural zeolite is analcime (Analcime).
_SiO2 / _Al2O3 =3.6 _{~ 5.6} ), Chabazite: _SiO2 / _Al2O3 =33~6.0 and 6.4~
7.6), Clinoptilolite:
SiO ₂ /Al ₂ O ₃ = 8.5 to 10.5), Erionite (Erionite: SiO ₂ / Al ₂ O ₃ = 5.8 to 7.4), Faujasite (SiO ₂ / Al ₂ O ₃ = 4.2 to 4.6),
mordenite: SiO ₂ /Al ₂ O ₃ = 8.34
~10.0), Philipsite:
SiO ₂ /Al ₂ O ₃ =2.6 to 4.4), and the like. These typical natural zeolites are suitable for the present invention. On the other hand, typical synthetic zeolites include A-type zeolite (SiO ₂ /Al ₂ O ₃ = 1.4-2.4),
-type zeolite (SiO ₂ /Al ₂ O ₃ = 2-3), Y-
_These synthetic _zeolites are suitable as _{the zeolite} material of the _present invention _. . Particularly preferred are
Synthetic A-type zeolite, X-type zeolite, Y
- type zeolites and synthetic or natural mordenites. The shape of the zeolite is preferably in the form of powder particles;
The particle size may be appropriately selected depending on the application, but is preferably 20 μm or less. When the average particle diameter exceeds 20 μ, the texture of the dispersed state tends to become rough, and the light resistance effect decreases. Thick molded products may be a few microns to 20 microns when applied to various containers, pipes, granular materials, or thick denier fibers, etc. On the other hand, when molded into fine denier fibers or films, the particle size is small. In particular, in the case of textiles for clothing, it is preferably 5μ or less, more preferably 2μ or less. Next, the vehicle used in the present invention is preferably a viscous liquid that is kneaded with zeolite solid particles to form a slurry and has poor reactivity with polyamide. Examples include polyethylene glycol, polytetramethylene glycol, polyoxyethylene triglyceride, polybutylene adipate, diethylene glycol adipate, etc., and the viscosity at 75° C. is preferably about 500 to 900 cps. The method of kneading the zeolite solid particles with the vehicle is not particularly limited, and any method that can form a slurry may be used, such as an automatic mortar or a three-roll kneader. The concentration of zeolite solid particles in the slurry is preferably 50% by weight or less. If it exceeds 50% by weight, thixotropy will develop and it will be difficult to form a slurry. The slurry is added to and mixed with molten polyamide. For example, in the case of spinning, there is a method of pressurizing the slurry with a gear pump into the polyamide that has been melted by a screw and fed into a spinning head. On the other hand, when zeolite solid particles are melt-spun in powder form without slurrying, for example, polyamide and chip blend, secondary agglomeration of the zeolite solid particles occurs, resulting in the formation of fine particles into polyamide. Mixing as is may be difficult, and uniform dispersion is also difficult. On the other hand, the method of kneading zeolite-based solid particles with a vehicle to form a slurry and adding this to molten polyamide prevents secondary aggregation of zeolite-based solid particles, maintains a fine particle state, and improves uniform dispersibility. It is possible to do so. By adding the slurry to the molten polymer and then kneading it with a static kneading element or the like, more uniform dispersion can be achieved. Being able to maintain the zeolite solid particles in a fine state makes it possible to reduce the increase in overpressure when passing through a layer of overmaterial in a spinneret pack, for example, and improve uniform dispersion. This means that the dispersibility of copper ions also improves, which is extremely effective for improving light resistance. The polyamides used in the present invention include nylon 6, nylon 66, nylon 11, nylon 12, and copolyamides thereof. The zeolite-based solid particles and vehicle-containing polyamide molded article of the present invention is composed of the zeolite-based solid particles, the vehicle, and the polyamide, and at least a portion of the zeolite-based solid particles retain copper ions. . The proportion of zeolite solid particles in the whole is 0.005 to 10% by weight.
(based on anhydrous zeolite). If it is less than 0.005% by weight, it is difficult to retain enough copper ions to have a light resistance effect, and even if it exceeds 10% by weight, the light resistance effect is almost unchanged and the physical properties of polyamide are The change becomes large, and its use as a polyamide molded product is limited. From this point of view, the content range is more preferably 0.01 to 6% by weight, and more preferably 0.01 to 4% by weight when the particle-containing polyamide molded article of the present invention is used in the form of fibers. Copper ions must be retained in the zeolite solid particles through an ion exchange reaction. If the material is simply adsorbed or attached without ion exchange, the light resistance effect and its durability will be insufficient. There are two possible methods for retaining copper ions. The first method is to add and mix a slurry of copper-zeolite and vehicle to polyamide, and the second method is to add and mix a slurry of zeolite and vehicle to polyamide and then mold it.
This is a method in which a polyamide molded body is subjected to an ion exchange treatment to cause copper ions to be retained in zeolite within the polyamide composition. First, the first method will be explained. This method utilizes copper-zeolite, and the copper-zeolite is
As mentioned above, zeolite can be prepared using an ion exchange reaction. When converting the various zeolites defined in the present invention into copper-zeolites, a solution of water-soluble copper salts such as copper sulfate is usually used, but care must be taken to ensure that the concentration does not become excessive. . For example, A-type or X-type zeolite (sodium type) is subjected to an ion exchange reaction,
When converting to Cu-zeolite, Cu ²⁺ replaces Na ⁺ in the solid phase when 1M-CuSO ₄ is used, but at the same time, Cu ₃ (SO ₄ ) (OH) ₄ etc. in the zeolite solid phase Due to the precipitation of basic precipitates, the porosity of the zeolite is reduced and the specific surface area is significantly reduced. In order to prevent such excessive copper precipitation into the zeolite phase, it is desirable to keep the concentration of the aqueous copper solution used in a more dilute state, for example, 0.05M or less. When a CuSO ₄ solution of such a concentration is used, the specific surface area of the Cu-zeolite obtained is almost the same as that of the converted material zeolite, and the light resistance effect can be exhibited in an optimal state. Above copper-zeolite (based on anhydrous zeolite)
Theoretically, the maximum amount of Cu in zeolite is approximately 22% by weight for A-type zeolite, approximately 20% by weight for X-type zeolite, approximately 16% by weight for Y-type zeolite, and approximately 8% by weight for mordenite. , the preferred range is 0.01-15% by weight. Also, metal ions other than copper, such as sodium,
The coexistence of potassium, calcium, or other metal ions does not impede the light resistance effect, so the residual or coexistence of these ions is not a problem. The copper zeolite is then kneaded with a vehicle,
The composition of the present invention is obtained by forming a slurry and adding and mixing the slurry to polyamide so as to have the above-mentioned content. The amount of copper relative to the copper-zeolite (given as weight percent A) and the amount of copper-zeolite relative to the polyamide composition (given as weight percent B) are both related to the lightfastness effect; the more A, the less B is needed. , if A is small, it is necessary to increase B. In order to effectively exhibit the light resistance effect, the value of A x B x 1/100 (i.e., the weight % of copper ions retained in the zeolite solid particles relative to the entire polyamide composition) should be adjusted to be 0.001 to 0.5. There must be. If it is less than 0.001, the light resistance effect is poor, and if it exceeds 0.5, the light resistance effect is almost unchanged, and depending on the temperature conditions, metal copper may precipitate, although slightly, during molding or melt spinning. Coloring that appears to occur occurs. The timing and method of addition and mixing are not particularly limited. For example, there are a method of adding and mixing to raw material monomers and then polymerizing them, a method of adding and mixing to reaction intermediates, a method of adding and mixing to the polymer after completion of polymerization, a method of adding and mixing to a forming dope, for example, a spinning dope, and the like. Below, for the sake of simplicity, these methods are simply
It is said to be "added to and mixed with polyamide." In short, the most suitable method may be adopted depending on the properties of the polyamide used, characteristics of the process, etc. Usually, the best method is to add and mix just before molding. Further, the copper-zeolite is subjected to a drying treatment, if necessary, before being made into a slurry. Drying conditions may be appropriately selected from the range of 100 to 500°C under normal pressure or reduced pressure. Preferred drying conditions are under reduced pressure
The temperature is 100-350℃. Next, the second method of the present invention will be explained. The second method is basically similar to the first method in many respects, although the timing of the ion exchange treatment is different. First, the zeolite defined above is kneaded with a vehicle without ion exchange to form a slurry, and the slurry is added to and mixed with polyamide. The content range of zeolite is the same as in the first method. The timing and method of addition and mixing are not particularly limited. As in the first method, the additives may be added and mixed at any stage from the preparation of polyamide raw materials to molding. Furthermore, if it is necessary to dry the zeolite, the method described above may be followed. In the second method, the zeolite-containing molded body thus obtained is subjected to an ion exchange treatment. The type and shape of the molded product are not particularly limited; for example, it may be an intermediate molded product such as a pellet, or it may be in the form of a final product. In order to increase the ion exchange efficiency, a molded body with a large specific surface area is suitable. Therefore, a molded body having a small diameter and thickness is preferable, such as a granular body, a film, or a fiber. The method of ion exchange treatment is basically similar to the method of ion exchange treatment of zeolite described above, and the zeolite-containing polyamide molded body is
Treatment with a solution of water-soluble copper salts. In this case, the concentration range of the copper salt is preferably 0.05M or less in the case of CuSO ₄ . If the concentration of Cu salt is too excessive, basic precipitation of copper will precipitate, reducing the light resistance effect. As the processing method, either a batch method or a continuous method is possible. In order to increase the amount of metal ions retained, the number of batch treatments may be increased or, in the case of a continuous method, the treatment time may be increased. The second method shows that the zeolite entrapped within a polymer still retains ion exchange capacity, and that by appropriate ion exchange treatment it can be made to retain copper ions. The proportion of zeolite within the polyamide that is ion-exchanged depends on the nature of the polyamide. However, since most polyamides are hydrophilic, as water permeates, copper ions permeate into the interior, and the zeolite inside the polyamide is also ion-exchanged. In the second method as well, the amount of copper ions retained in the zeolite solid particles is preferably 0.001 to 0.5% by weight based on the entire polyamide composition. In the second method, no precipitation of metallic copper occurs even if the proportion of copper is extremely increased, but it takes too much time, and the optimum upper limit is 0.5% by weight. Further, the remaining or coexistence of other metal ions is not a problem. The zeolite particles and vehicle-containing polyamide molded article of the present invention may contain a fourth component other than the copper zeolite and the vehicle. Examples include polymerization catalysts, stabilizers, matting agents, brighteners, organic or inorganic pigments, inorganic fillers, and various plasticizers. Furthermore, a liquid or an organic solvent may be contained as a fourth component. Moreover, the shape, size, etc. of the zeolite particles and vehicle-containing molded article of the present invention are not particularly limited. The distribution of the copper-zeolite within the molded body may be appropriately devised. For example, there is a method in which the outer layer of the multilayer structure contains the zeolite and the vehicle according to the present invention. In the case of fibers, the core is made using the well-known conjugate spinning technology.
There is a method of incorporating zeolite and vehicle into the sheath component of the sheath-shaped cross-section yarn. The bonding force between zeolite and copper ions as defined in the present invention is extremely large, unlike a method in which the zeolite and copper ions are retained simply by physical adsorption on an adsorbent material such as activated carbon or alumina. Therefore, the light-fastness effect of the polyamide composition containing such copper zeolite and its long-term durability should be particularly mentioned as a characteristic advantage of the present invention. The zeolite limited as in the present invention is Cu
It has the advantage of high reactivity with For example, ion-exchangeable metal ions ( ^{Na +} ) in A-type zeolite, and has a high retention ability. Furthermore, the zeolite defined as in the present invention has the advantage of high selective adsorption to Cu ²⁺ . This fact shows that even when the polyamide molded article containing zeolite particles of the present invention is used in liquids containing various metal ions or in water for the purpose of light resistance, Cu ²⁺ is stably retained in the zeolite matrix for a long period of time, resulting in light resistance. This means that it will last for a long time. In addition, the zeolite limited as in the present invention is
Its exchange capacity is large, which has the advantage of increasing the amount of Cu retained. Further, depending on the purpose of use of the zeolite particle-containing polymer of the present invention, there is an advantage that the amount of Cu contained in the zeolite solid particles can be easily adjusted by ion exchange. Moreover, the zeolite defined in the present invention hardly deteriorates the physical properties of the polymer, and a wide variety of polymer types can be selected. Since the zeolite particles and the vehicle-containing polyamide molded article of the present invention are mainly made of polyamide, they can be molded into various shapes and sizes. For example, it can be made into granules, films, fibers, various containers, pipes, or any other molded product, and can be used in a very wide range of applications requiring light resistance. Moreover, since the zeolite particles and the vehicle-containing polyamide molded article of the present invention also have the functions inherent to zeolite, it is possible to utilize both the light resistance and the functions inherent to zeolite. For example, the combined effect of zeolite's original functions of moisture absorption and adsorption and light resistance can be utilized. Furthermore, it is also possible to incorporate other functional substances to exhibit a combined function of the above effects and other functions. Other functional substances include activated carbon and silica gel. In the case of activated carbon, the deodorizing and adsorption effect is enhanced, and in the case of silica gel, the adsorption effect is enhanced. Examples of the present invention will be described below, but the present invention is not limited to these examples unless the gist thereof is exceeded. Reference Example 1 Table 1 shows unconverted natural and synthetic zeolite particles used in the examples of the present invention. Each zeolite was obtained by crushing and classifying crude raw materials to obtain the desired particle size. The A-type zeolite in Table 1 is abbreviated as Z ₁ , the X-type zeolite as Z ₂ , the Y-type zeolite as Z ₃ , natural mordenite 1 as Z ₄ , natural mordenite 2 as Z ₅ , and natural chabasite as Z ₆ . The particle diameter, water content, and specific surface area of these zeolites were as shown in Table 1. Next, 250 g of dried fine powder of each type of zeolite listed in Table 1 was collected, and 1/20 M copper sulfate aqueous solution was added to each.
The resulting mixture was kept under stirring at room temperature for 5 hours to perform ion exchange. The copper-zeolite obtained by this ion exchange method was filtered and then washed with water to remove excess copper ions. Next, the water-washed copper-zeolite was dried at 100 to 105°C and then ground to obtain a fine powder of copper-zeolite. The copper content and specific surface area of the dried copper-zeolite product obtained were as shown in Table 2. ( _No.Z7 to _Z12 )

【table】

[Table] Reference example 2 Dry powder of Y-type zeolite (Z ₃ ) shown in Table 1 250
1/200M copper sulfate solution was added thereto, and the resulting mixture was stirred at room temperature for 5 hours.
The copper-zeolite obtained by this ion exchange method was filtered and washed with water. (Z ₁₃ ) Separately, 250 g of dry powder of Y-type zeolite (Z ₃ ) shown in Table 1 was collected, and 1/20M copper sulfate solution was added to it.
was added and stirred at room temperature for 5 hours, and the obtained copper-zeolite was separated by centrifugation. Next, the same process as above was repeated eight times. The finally obtained converted product was washed with water to remove excess copper ions. (Z ₁₄ ) The above two samples of copper-zeolite were dried at 100 to 105°C and then ground to obtain finely powdered copper-zeolite. The copper content and specific surface area of this are shown in Table 3.

[Table] Example 1 The copper-zeolites (Z ₇ to Z ₁₂ ) shown in Table 2 were each dried at 200° C. for 7 hours under reduced pressure. Next, take 50g of each of these and determine the viscosity of each at 75℃.
800cps diethylene glycol adipate 100g
were mixed and kneaded in an automatic mortar for 24 hours to form a slurry. At this time, the slurry was kept at a temperature of 60 to 70°C while being irradiated with an infrared lamp. 0.5 in 95% sulfuric acid using a regular melt spinning machine.
g/500c.c. concentration, relative viscosity measured at 25°C 6 of 2.3
Dry nylon chips were melted with a screw, and the copper-zeolite-containing slurry was forced into the molten nylon 6 polymer fed into a spinning head with a gear pump. At this time, the slurry was made to account for 3% by weight based on the entire mixed polymer. After passing it through 20 static kneading elements in the spinning head, it is extruded from the spinneret and wound up, and the resulting undrawn yarn is stretched.
Six types of drawn yarns of 50 denier/12 filaments were obtained. Separately, 50 g of each of the vacuum-dried copper-zeolite powders shown in Table 2 were taken, added to and mixed with nylon 6 dry chips so that the copper-zeolite content was 1% by weight as a whole, and melt-spun according to a conventional method. At this time as well, the mixture was passed through 20 static kneading elements in the spinning head. The resulting undrawn yarns were drawn to obtain six types of drawn yarns of 50 denier/12 filaments. Furthermore, a drawn yarn of 50 denier/12 filaments was also collected as a control yarn using only nylon 6. Table 4 shows the results of measuring the strength of these 13 types of drawn yarns after irradiating them with an ultraviolet fade meter for 200 hours.

【table】

[Table] As shown in the table above, the method of slurrying and press-fitting had better strength retention after irradiation with ultraviolet rays than the method of adding and mixing by chip blending. Regarding the type of zeolite, any of the ones in the table above are good if it is a slurry method, but especially type A,
X-type, Y-type zeolite and mordenite 1 were good. Example 2 The copper-Y type zeolite (Z ₉ ) shown in Table 2 and the copper-Y type zeolite (Z ₁₃ , Z ₁₄ ) shown in Table 3 were each dried at 200°C under reduced pressure for 7 hours. Then add this to 100 each
Each g of the mixture was taken and mixed with 150 g of polyoxyethylene triglyceride at 600 cps at 75°C, and kneaded using three kneading rolls heated to 80°C to form a slurry. Using a conventional spinning machine, nylon 6 chips with a relative viscosity of 2.3 measured with 95% sulfuric acid are melted with a screw, and the copper-zeolite slurry is poured into the molten nylon polymer fed into the spinning head using a gear pump. After passing through 15 static kneading elements, extrude it from the nozzle, roll it up, and stretch it to 120 mm.
The drawn yarn had a denier/4 filament. At this time, the amount of each slurry injected into the whole is the fifth
The results are shown in the table, and the strength results after 120 hours and 400 hours of irradiation of the drawn yarn obtained by this method with an ultraviolet fade meter are also shown.

[Table] From the results in Table 5, the content of copper in the drawn yarn is:
It has been found that light resistance is poor unless the amount is more than 0.001% by weight. Furthermore, when copper was added to the polymer in an amount greater than 0.5% by weight, slight coloring was observed in the polymer, but the light resistance was good. In addition, the copper-zeolite particles in the drawn yarn are 10% by weight.
It was also found that the strength of the drawn yarn is significantly lower when the amount exceeds .

Claims (1)

[Scope of Claims] 1. Consists of zeolite-based solid particles holding copper ions, a vehicle, and polyamide, and the content of the zeolite-based solid particles is 0.005 to 10% by weight,
A polyamide molded article having light resistance, characterized in that the content of copper ions retained in the zeolite solid particles is 0.001 to 0.5% by weight based on the entire molded article. 2. The molded article according to claim 1, wherein the zeolite solid particles have a specific surface area of 150 m ² /g or more and a SiO ₂ /Al ₂ O ₃ molar ratio of 14 or less. 3 The zeolite solid particles are type A zeolite,
The molded article according to claim 1, which is composed of type zeolite, Y type zeolite, or mordenite. 4. The molded article according to claim 1, wherein the vehicle is diethylene glycol adipate or polyoxyethylene triglyceride.