JPH0873735A - Polyamide resin composition for optical part, and part for optical communication - Google Patents

Abstract

PURPOSE: To obtain a material for optical parts which contains a rate earth element uniformly in a high concentration, has excellent moldability and heat resistance inaccessible so far, and can be produced by a simple and easy process. CONSTITUTION: This composition consists of a polyamide resin containing 0.01-25wt.% rare earth element cations and has a light transmittance at a thickness of 3mm of at least 50% in the wavelength region from 1,300 to 1,500nm except the absorption assignable to the rare earth element cations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin composition for optical parts and optical communication parts. For more information,
The present invention relates to a polyamide resin composition containing a rare earth element cation, and particularly to a polyamide resin composition for optical components having excellent transparency to light in the near infrared region, a method for producing the same, and uses thereof. The resin composition of the present invention has features such as absorption of light of a specific wavelength derived from rare earth element cations and generation of fluorescence accompanying this, or high refractive index, and optical communication parts including optical amplifiers. It is used in a wide range of optical fields, such as nonlinear optical materials and lenses.

[0002]

2. Description of the Related Art Conventionally, inorganic glass has been the predominant material used for manufacturing products in the optical field. It has excellent light transmittance in a wide wavelength range of inorganic glass, heat resistance, chemical resistance, water resistance, surface hardness, abrasion resistance,
This is due to characteristics such as a low coefficient of linear expansion. In recent years, due to advances in manufacturing technology for organic polymer materials, acrylic resins,
Transparent amorphous thermoplastics such as styrenic resins and aromatic polycarbonate resins have been developed, and applications that take advantage of features not possessed by inorganic glass, such as excellent moldability, lightness, and toughness, such as cameras In addition to the widespread use as materials for eyeglasses, lens materials for spectacles, headlamp covers for automobiles, etc., inorganic glass, which has a long history of use, still predominates in such general-purpose applications.

On the other hand, in a new field such as optical communication and electronic information, there is a property that the conventional inorganic glass does not have in the function of amplifying the loss (decrease in signal strength) at the time of light transmission and the wavelength conversion function. Optical materials are needed. In order to realize such functionalization, it is generally necessary to introduce an element or a molecular structural unit that exerts these functions, and the material is mixed or chemically modified. , The adaptability to such functionalization or compositing was not sufficient.

Recently, as an optical fiber amplifier material, an inorganic glass doped with a cation of a rare earth element such as erbium has attracted attention (for example, Electronics, 199).
September 0 issue, pages 56-60, or OPTRONI
CS, 1990, No. 11, 47-53). this is,
This is an application of excitation of an electron in an erbium cation atom by a light beam in the visible to near-infrared region and a fluorescence generation phenomenon of a wavelength of about 1.5 μm. However, when inorganic glass is used as the matrix, the solubility of erbium cations is relatively low, so addition of at most several 100 ppm makes cluster formation due to the association of these cations remarkable, and addition of more than this causes conversely excitation. There is a drawback that the efficiency is reduced, that is, a peak of the optical amplification function is observed. Further, since it is an inorganic glass material, its toughness and moldability were not always satisfactory.

For the purpose of remedying these drawbacks, for example,
The 991 IEICE Proceedings 4-232, etc.
A method of obtaining a quartz film containing a rare earth element at a high concentration and uniformly by a hydrolysis-condensation reaction in a homogeneous solution using a metal alkoxide and a chloride of a rare earth element as raw materials is disclosed. However, such a method has a problem in molding such that it is difficult to mold a thick quartz film on the substrate because cracking and peeling of the quartz film from the substrate occur.

On the other hand, the addition of rare earth element cations to organic polymer materials has also been studied. For example, JP-A-5-86
No. 189 discloses a rare earth element obtained by using chlorosilanes having an organic group and a chloride of the rare earth element as a raw material.
Polysiloxanes incorporated into polymeric chains are disclosed. Further, JP-A-5-88026 discloses a material containing a complex such as an acetylacetone complex of a rare earth element, which is excellent in solubility in an organic solvent and oxidation resistance, in polyacrylate or polysiloxane. . Furthermore, Proceedings of the Society of Polymer Science, Vol. 43 (1), 29 (1994)
In order to increase the cation concentration to about 10% by weight, a rare earth element cation salt of a polymerizable organic acid such as acrylic acid or methacrylic acid is synthesized and the rare earth cation-supporting monomer is polymerized or copolymerized. The possible materials have been reported. By these methods, a rare earth element cation can be added at a high concentration to an organic polymer material having excellent moldability, but the synthesis method is complicated, and it may be an economic constraint in industrial applications. , And the resin used had the drawback of relatively low heat resistance.

[0007]

DISCLOSURE OF THE INVENTION The present invention is for an optical component which contains a rare earth element in a high concentration and uniformly, has molding processability and heat resistance which have not been obtained, and which can be manufactured by a simple method. The purpose is to provide materials, optical components molded from these materials, and the like.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 comprises a polyamide resin containing 0.001 to 25% by weight of rare earth element cations. Excluding ion absorption wavelength 1
A light-transmittance at a thickness of 3 mm in a wavelength region of 300 to 1550 nm is 50% or more, and a polyamide resin composition for optical parts is provided. Further, in the invention described in claim 3, a manufacturing method is adopted in which a polyamide monomer is dissolved in a salt aqueous solution of a rare earth element cation, the temperature of the resulting solution is raised to distill off water and polymerize the polyamide. ,
That is the means. Further, claim 4
In the invention described in (1), a means for providing an optical communication component obtained from the polyamide resin composition for optical components according to (1) or (2) is taken.

The present invention will be described in detail below. In the present invention, the polyamide resin means an amide bond (-N
HCO-) is a polymer that can be melted by heating. In the present invention, a polyamide resin having excellent transmittance in light rays in the visible to near infrared region is suitable. The raw materials for the polyamide resin are diamines and dicarboxylic acids, lactams, or polymerizable ω-amino acids, salts of diamines and dicarboxylic acids, and oligomers of these raw materials.

Specific examples of such polyamide raw materials are as follows. Note that the present invention is not limited to the examples given below. Diamines: Aliphatic diamines such as tetramethylenediamine, hexamethylenediamine, bis (3-methyl-4-aminocyclohexyl) methane (also referred to as laromine),
Dicarboxylic acids such as xylylenediamines: Aliphatic dicarboxylic acids such as adipic acid and sebacic acid, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid, dimerized fatty acids, iminodiacetic acid, Dicarboxylic acids containing aromatic rings such as oxydiacetic acid, thiodiacetic acid, 1,4-phenyleneoxydiacetic acid, 1,3-phenylenedioxydiacetic acid, 2,6-naphthalenedioxydiacetic acid, etc. Lactams: caprolactam, undecano Lactam, dodecanolactam, etc. Polymerizable ω-amino acids: 6-aminocaproic acid, 1
1-aminoundecanoic acid, 12-aminododecanoic acid, etc.

Specific examples of the polyamide resin usable in the present invention include polytetramethylene adipamide (nylon 46), polycaprolactam (nylon 6), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebaca. Aliphatic polyamides such as amide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecanolactam (nylon 11), polydodecanolactam (nylon 12), terephthalic acid and / or isophthalic acid and hexamethylene diamine Polyamide obtained from, polyamide obtained from adipic acid and metaxylylenediamine, terephthalic acid and / or polyamide obtained from adipic acid and hexamethylenediamine, terephthalic acid and / or isophthalic acid Polyamide obtained from taric acid, adipic acid and metaxylylenediamine, copolymerized polyamide containing 1,3-phenylenedioxydiacetic acid as a copolymerization component, copolymerization containing 2,6-naphthalenedicarboxylic acid as a copolymerization component Aromatic polyamides, such as polyamide, are mentioned. These may be used alone or as a mixture of plural kinds.

From the viewpoint of transparency, heat resistance, water resistance, gas permeation resistance, etc., a particularly preferable polyamide resin is aromatic polyamide. Among aromatic polyamides, polyamides obtained from terephthalic acid and / or isophthalic acid and hexamethylenediamine, polyamides obtained from adipic acid and metaxylylenediamine, terephthalic acid and / or isophthalic acid, adipic acid and metaxylylenediene Polyamides obtained from amines are preferable from the viewpoint of easy availability of raw materials.

The molecular weight of these polyamide resins is not particularly limited, but usually the number average degree of polymerization is 70 to 50.
It can be selected in the range of 0. From the viewpoints of toughness and formability, it is preferable to select in the range of 100 to 400. Also,
The refractive index can be adjusted by changing the composition of the polyamide resin, for example, by selecting the type and amount of the aromatic group-containing monomer.

Generally, for optical communication using an optical fiber or the like, a wavelength range of 1300 to 1 is usually suitable because the optical loss of silicon glass fiber is the smallest.
Light in the near infrared region having a wavelength of about 550 nm is used as communication light. Therefore, it is desirable that the polyamide resin composition of the present invention has excellent light transmittance in the above wavelength range. Usually, the light transmittance in the wavelength region of 1300 to 1550 nm excluding the absorption wavelength of rare earth element cations described below needs to be 50% or more at a thickness of 3 mm. If the light transmittance is less than 50%, the dispersion of rare earth element cations is poor and there is a problem with transparency, so it is unsuitable as an optical material. The light transmittance of the polyamide resin composition is preferably 60% or more, more preferably 7%.
It is 0% or more, and most preferably 75% or more.

As described above, in order to obtain a polyamide resin composition having a high light transmittance in the above wavelength range, the monomer component constituting the polyamide resin is carbon-hydrogen bond, carbon-deuterium bond or carbon-hydrogen bond. By using a fluorine bond, the overtone component of absorption in the infrared (IR) region derived from the carbon-hydrogen bond is prevented from being included in the above-mentioned near-infrared wavelength region, and the light transmittance in the above-mentioned wavelength region is increased. It is possible.

In the present invention, the above polyamide resin contains a rare earth element cation. The rare earth element cation has a function of imparting unique optical characteristics to the resin composition, such as a light amplification function and a wavelength conversion function. The rare earth element used in the present invention means scandium (Sc), yttrium (Y) contained in Group 3A of the periodic table, and the following elements collectively referred to as lanthanoids: lanthanum (La), cerium (Ce), Praseodymium (P
r), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (D)
y), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), or lutetium (Lu). The polyamide resin composition of the present invention contains the rare earth element in the form of cations, but the rare earth element cations may be used alone or in combination of two or more.

There is no limitation on the valence of the rare earth element cation, and it is usually used as a divalent or trivalent cation, and is usually used in the form of a salt. As the salt, chloride, bromide, iodide, nitrate, perchlorate, bromate, acetate, sulfate and the like are preferable from the viewpoint of dispersibility in the polyamide resin. Further, double nitrate, double sulfate and chelate can be used. Although the above-mentioned cation fluorides, carbonates, phosphates, oxalates, etc. can be used, their dispersibility in a polyamide resin may be poor, so special consideration is required when compounding and dispersing. .

Salts containing a rare earth element suitable for the present invention include praseodymium chloride, praseodymium bromide, praseodymium iodide, praseodymium nitrate, praseodymium perchlorate,
Praseodymium bromate, praseodymium acetate, praseodymium salts such as praseodymium sulfate, neodymium chloride, neodymium bromide, neodymium iodide, neodymium nitrate, neodymium perchlorate, neodymium bromate, neodymium acetate, neodymium sulfate and other neodymium salts, europium chloride, Europium bromide, europium iodide, europium nitrate, europium perchlorate, europium bromate, europium acetate, europium sulfate, and other europium salts, dysprosium chloride, dysprosium bromide, dysprosium iodide, dysprosium perchlorate, bromine Dysprosium acid, dysprosium acetate, dysprosium sulfate, etc., dysprosium salts, erbium chloride, erbium bromide, erbium iodide, erbium nitrate, erbium perchlorate, erbium bromate , Erbium acetate, and the like can be given erbium salts such as sulfuric acid erbium.

Of these, praseodymium salt, neodymium salt, and erbium salt having near-infrared fluorescence generating ability are particularly suitable for use in optical amplifiers, and among them, at a signal wavelength suitable for fibers of inorganic glass such as silica glass. There is one
Most preferred are neodymium salts, praseodymium salts, and erbium salts, which have a fluorescence-generating ability at a wavelength of about 300 to 1550 nm. In addition, when the europium salt and the dysprosium salt are used in combination, the afterglow characteristic in which the fluorescence generation lasts for a long time may be obtained.

The polyamide resin composition of the present invention contains a rare earth element cation in an amount of 0.001 to 25% by weight (% by weight as an ion). When this amount is less than 0.001% by weight, desirable properties such as light amplification effect are hardly exhibited, and when it exceeds 25% by weight, the dispersibility of the cation may be extremely deteriorated. Not preferable. In the case of an optical communication component such as an optical amplifier or an optical waveguide, the content of this cation is 0.01 to 0.01 from the viewpoint of fluorescence intensity.
The range is preferably 20% by weight, more preferably 0.1 to 15% by weight, and most preferably 0.5 to 10% by weight. The content of rare earth element cations is 650.
It can be measured by quantifying the ash when an organic component is burned in an electric furnace at a temperature of about ℃, or by a physicochemical method such as fluorescent X-ray analysis.

As described above, the polyamide resin composition of the present invention is 1300 to 1300 excluding the absorption wavelength of rare earth element cations.
The light transmittance in the wavelength region of 1550 nm needs to be 50% or more in a thickness of 3 mm. Here, the absorption wavelength of the rare earth element cation is, for example, 98 for erbium.
0nm, 1530nm, etc., neodymium 820nm, etc.
For praseodymium, 1017 nm and the like can be mentioned. In order to make the light transmittance of the resin composition excellent in the above range, it is necessary to satisfactorily disperse the rare earth element cations in the resin matrix. The smaller the average dispersed particle size of this cation domain is, the more preferable, but it is usually 100 nm or less, preferably 70 nm or less, more preferably 50 nm or less, further preferably 40 nm or less, most preferably 30 nm or less.

In an optical amplifier such as an optical fiber amplifier which plays a role of recovering the attenuation of communication light, pumping light (pump light) which effectively excites rare earth elements that generate fluorescence at the wavelength of communication light is always passed through the optical amplifier. Due to the stimulated emission phenomenon due to the light pulse, the same fluorescence as that of the pulse waveform is generated and an amplification effect is obtained. Therefore, when the resin composition of the present invention is used as an optical amplifier, it is necessary to have the ability to generate fluorescence in excitation light derived from rare earth element cations.

The method of adding the rare earth element cation to the polyamide resin is not particularly limited, and for example, (1) after the addition of the above cation to the polyamide resin monomer, a known method such as a melt polymerization method or an anionic polymerization method is used. A method of producing a polyamide by a polyamide synthesis method, (2) a method of adding the cation to a polyamide resin solution and mixing and then removing the solvent, or (3) a method of melt-kneading the polyamide resin and the cation, Etc.

Of these, the method (1) is most preferable in terms of cation dispersibility in the polyamide resin. A particularly preferred method is a melt polymerization method in which a monomer for polyamide production is dissolved in an aqueous solution of the above cation salt, the temperature of the obtained homogeneous solution is elevated to distill off water, and the monomer is polymerized. By this method, the existing polyamide production process can be utilized as it is, which is a very advantageous method industrially. When the polyamide resin composition is used as a masterbatch for dilution, the method of dilution is not limited, but it is usually melt-mixed in a device such as a twin-screw extruder capable of applying strong shearing. It

The polyamide resin composition of the present invention contains polyethylene, polypropylene, an ethylene-α-olefin copolymer, if necessary, within a range not impairing transparency.
Polyamide elastomer, polyester elastomer,
Other thermoplastic resins such as polyester ether amide, polyether elastomer, styrene-based thermoplastic elastomer or its acid-modified product, acrylic rubber, core-shell type acrylic rubber, ionomer resin, polyphenylene ether, aromatic polycarbonate, aromatic polyester, epoxy resin, etc. Inorganic fillers such as fumed silica, talc, kaolinite, glass beads, glass flakes, clay, calcium carbonate, calcium sulfate, alumina, titania, zirconia; lubricants such as calcium stearate, barium stearate, zinc stearate; etc. Additives such as heat stabilizers, ultraviolet absorbers, pigments, carbon black, Ketjen black, graphite, antioxidants, plasticizers and antistatic agents used in polyamide resins can be mixed.

Since the polyamide resin composition for optical parts of the present invention has excellent moldability, it is possible to manufacture a desired molded article by various molding methods adopted for molding a polyamide resin. . Examples of the molding method include an injection molding method, an extrusion molding method including a T-die film forming method and an inflation molding method, a blow molding method, a differential pressure molding method such as a vacuum molding method and a pressure molding method, and compression molding. By such a molding method, an injection molded product of any shape, a sheet, a film, a laminated film, a rod-shaped molded product, a fiber,
Molded articles such as filaments, yarns and hollow molded articles can be used. In the case of forming a sheet, a film, or a hollow molded product, the stretching used for molding a polyamide resin is also possible.

The polyamide resin composition for optical parts of the present invention makes use of features such as excellent moldability, lightness, toughness, transparency, light amplification action, wavelength conversion action, and high refractive index, and has an arbitrary shape. It can be used for optical components. Examples thereof include optical amplifiers, optical waveguides, optical communication components such as optical fibers, non-linear optical elements, lenses, and dark fluorescent materials. Moreover, since the resin composition of the present invention has a good light transmittance in the visible region, it is also preferably used for a lens for visible light and the like.

[0028]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. [Evaluation method] (1) Fluorescence measurement After sandwiching the dried sample between two cover glasses (about 150 nm thick) and heating the cover glass to 280 ° C, the sample thickness becomes about 0.5 mm. It was crushed into a transparent sample plate. UV-31 manufactured by Shimadzu Corporation is used for the sample that is still sandwiched between the cover glasses.
00S UV-visible-near infrared absorptiometer
Measure the absorption spectrum in the wavelength region of ~ 1700 nm,
The absorption wavelength corresponding to the peak of absorbance was determined and used as the excitation wavelength for the fluorescence measurement described below. For samples containing europium,
The absorption wavelength derived from europium obtained by the above absorption spectrum measurement was used as an excitation wavelength, and F-3 manufactured by Hitachi, Ltd.
The fluorescence spectrum in the wavelength region of 300 to 700 μm was measured with a 000 type fluorimeter. 15 samples each for erbium, praseodymium, or neodymium
Since it is known to generate fluorescence in the near infrared region near 00 nm or 1300 nm, the absorption wavelength derived from each element obtained by the absorption spectrum measurement is used as the excitation wavelength,
The presence or absence of near-infrared fluorescence was observed with a near-infrared camera equipped with a visible light cut filter.

(2) Light transmittance Using an injection molding machine (J28SA) manufactured by Japan Steel Works, Ltd., a flat plate having a thickness of 3 mm was molded from the dried sample. The molding conditions at this time were a barrel temperature setting of 280 ° C., a maximum injection speed, and a mold temperature of 80 ° C. The light transmittance spectrum of the thus obtained flat plate having a thickness of 3 mm was measured in the wavelength region of 400 to 1550 nm by the absorptiometer described above. Then, the minimum value of the light transmittance in this wavelength region excluding the absorption wavelength derived from the rare earth element cation was obtained. (3) Content of rare earth element cations About 2 g of a sample was precisely weighed and calculated from the weight fraction of the residue completely incinerated in an electric furnace at 600 ° C. and shown in Table 1. (4) Refractive index A representative sample was measured at 23 ° C. with an Abbe type refractometer.

[Example 1] 25.1 g of erbium (III) acetate tetrahydrate (reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added to 95 ml of demineralized water.
It is dissolved at 100 ° C. with stirring, and 100 g of ε-caprolactam and 5 g of 6-aminocaproic acid are added to this and 12
The temperature was raised to 0 ° C. The obtained homogeneous solution was sealed in an autoclave having a capacity of 600 ml, and 18.5 g of terephthalic acid and 46.0 isophthalic acid prepared in advance under atmospheric pressure.
g, and 56.2 g of an 80% by weight aqueous solution of hexamethylenediamine were mixed with 98.2 g of demineralized water, and brine was added to the autoclave over about 5 minutes. The obtained homogeneous solution was stirred at 120 ° C. for 30 minutes and then the internal pressure was adjusted to 3.
While maintaining the pressure at 5 atm, at a temperature of 150 ° C., about 90% of the added water was distilled off. Further, while maintaining the internal pressure at 14 atm, the temperature was raised to 280 ° C. over about 3 hours to distill off water. Then, while maintaining the internal temperature at 280 ° C., the pressure was released to atmospheric pressure, and the polycondensation reaction was further performed for 2 hours in this state. The obtained polyamide resin composition was pink and transparent. The refractive index of this composition was measured and found to be 1.59. When an absorption spectrum of the obtained composition was measured, an absorption peak derived from erbium appeared at 980 nm, and fluorescence was measured using this as an excitation wavelength. The evaluation results are shown in Table-1.

Example 2 In the example described in Example 1, praseodymium (III) acetate dihydrate (Wako Pure Chemical Industries, Ltd. reagent) was used instead of erbium acetate (III) tetrahydrate. Performed the same operation as in the same example. Table 1 shows the evaluation results of the obtained composition.

Example 3 In the example described in Example 1, erbium (III) acetate tetrahydrate was replaced with europium (III) acetate tetrahydrate (reagent manufactured by Wako Pure Chemical Industries, Ltd.). Performed the same operation as in the same example. Table 1 shows the evaluation results of the obtained composition.

Example 4 In the example described in Example 1, neodymium acetate (III) monohydrate (reagent manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of erbium (III) acetate tetrahydrate. Is
The same operation as in the same example was performed. Table 1 shows the evaluation results of the obtained composition.

Example 5 In the example described in Example 1, ε-caprolactam and 6-aminocaproic acid were not added, and the above-mentioned brine was added to 37 g of terephthalic acid, 92 g of isophthalic acid, 46.1 g of laromine, and hexamethylene. 84.3 g of 80% by weight aqueous solution of diamine was added to demineralized water 19
The same operation as in the same example was carried out, except that the salt water was changed to 6.4 g. The glass transition point of this composition was 160 ° C. as measured by DSC. Table 1 shows the evaluation results of the obtained composition.

[Example 6] The same operation as in Example 1 was carried out except that erbium (III) acetate tetrahydrate was changed to 175 g in the example described in Example 1. The composition obtained had an ash content of 25.8% by weight and a minimum light transmittance of 35%. Then dry chips 2 of this composition
0 wt% and Novamid X21 manufactured by Mitsubishi Kasei Co., Ltd. (acid component: terephthalic acid / isophthalic acid = 2.5 / 1, diamine component: hexamethylenediamine, amorphous aromatic polyamide, number average degree of polymerization is about 90). , Novamid is a registered trademark of 80% by weight dry-blended and melt-mixed with an extruder having a single screw having a diameter of 30 mm under the conditions of screw rotation of 50 rpm and 280 ° C. to obtain a molten blend. It was Table 1 shows the evaluation results of the obtained melt blended product.

Comparative Example 1 In the example described in Example 1, except that erbium (III) acetate tetrahydrate was not added,
The same operation as in the same example was performed. The refractive index measured in the same manner as in Example 1 was 1.56. Table 1 shows the evaluation results of the obtained composition.

[Comparative Example 2] The same procedure as in Example 1 was carried out except that 4 mg of erbium (III) acetate tetrahydrate was used. In the absorption spectrum measurement,
Since the absorption peak derived from Er cation could not be confirmed, the fluorescence spectrum measurement was not performed. Table 1 shows the evaluation results of the obtained composition.

[0038]

[Table 1]

[0039]

INDUSTRIAL APPLICABILITY The present invention has the following particularly advantageous effects, and its industrial utility value is extremely large. 1. The polyamide resin composition of the present invention contains a rare earth element cation and has an excellent light transmittance for light in the visible to near-infrared region, and therefore has the ability to absorb light and generate fluorescence derived from this cation. In addition, an increase in the refractive index is recognized due to the presence of this cation. 2. Since the polyamide resin composition of the present invention has excellent moldability, lightness and toughness, it is very useful as various optical parts including optical communication parts such as optical amplifiers.

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Claims (4)

[Claims] 1. A rare earth element cation is added in an amount of 0.001 to 25.
A polyamide resin for optical parts, which is made of a polyamide resin contained by weight% and has a light transmittance of 50% or more at a thickness of 3 mm in a wavelength range of 1300 to 1550 nm excluding the absorption wavelength of the rare earth element cation. Composition. 2. The polyamide resin composition for optical parts according to claim 1, wherein the rare earth element is any one of erbium (Er), praseodymium (Pr), and neodymium (Nd). 3. The method according to claim 1, wherein the polyamide monomer is dissolved in a salt aqueous solution of a rare earth element cation, and the temperature of the resulting solution is raised to distill off water and polymerize the polyamide. 2. The method for producing a polyamide resin composition for optical parts according to 2. 4. A component for optical communication, which is obtained from the polyamide resin composition for optical components according to claim 1 or 2.