JP2019026802A - Polyamide resin composition for visible tank and visible tank - Google Patents

Abstract

To provide a polyamide resin composition that can mold a visible tank having excellent transparency after kept in a high temperature atmosphere for a long time, and a visible tank.SOLUTION: A polyamide resin composition for visible tank contains, based on 100 pts.mass of a polyamide resin, 40-100 pts.mass of an inorganic filler and 0.5-5.0 pts.mass of a phosphorous antioxidant. The polyamide resin contains a semi-aromatic polyamide resin and an aliphatic polyamide resin at a mass ratio of 95:5-40:60. The phosphorous antioxidant contains two or more phosphorus atoms in the molecule.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide resin composition for a visibility tank and a visibility tank. In particular, the present invention relates to a visibility tank that is used in a high temperature atmosphere for a long time and requires visibility.

Polyamide resins are used in various molded products such as automotive parts because of their excellent mechanical properties and heat resistance.
For example, Patent Document 1 includes polyamide resin (A) 65 to 97 parts by mass, acid-modified polyolefin (B) 1.5 to 15 parts by mass, unmodified polyolefin (C) 1.5 to 15 parts by mass, and silane coupling. A polyamide resin composition containing 0.1 to 5 parts by mass of the agent (D) so that the total of (A) to (D) is 100 parts by mass, and the acid-modified polyolefin (B) and unmodified A polyamide resin composition characterized in that the total amount of polyolefin (C) is 3 to 20 parts by mass is disclosed. Further, it is described that such a resin composition is preferably used for a visibility tank such as a fuel tank.

  Patent Document 2 contains 100 parts by mass of a polyamide resin (A) and 0.5 to 3.0 parts by mass of a coupling agent (B), and has a transmittance of 40% or more. A molding polyamide resin composition is disclosed. Moreover, visibility tanks, such as a fuel tank and an oil tank, are described as a use of this resin composition.

JP 2014-062194 A JP 2017-048284 A

As described above, polyamide resin compositions used for visibility tanks are known. Here, fuel tanks are the mainstream of resin-made automobile tanks. However, from the viewpoint of reducing the weight of automobiles, the application of resin materials to tanks other than fuel tanks, such as tanks used in cooling systems, is expected. Under such circumstances, a tank that is excellent in transparency after being placed in a high temperature atmosphere for a long time in addition to excellent transparency is required.
The present invention aims to solve such problems, and is a polyamide resin composition capable of molding a visibility tank excellent in transparency after being placed in a high temperature atmosphere for a long time, the resin composition An object of the present invention is to provide a visibility tank using an object.

上記式（１）中、＊は他の部位との結合位置であり、＊＊は他の部位との結合位置または水素原子である。
＜４＞前記リン系酸化防止剤が、分子中にリン原子を２つ含む、＜１＞〜＜３＞のいずれか１つに記載の視認性タンク用ポリアミド樹脂組成物。
＜５＞リン系酸化防止剤の含有量が、視認性タンク用ポリアミド樹脂組成物の１．０〜３．０質量％である、＜１＞〜＜４＞のいずれか１つに記載の視認性タンク用ポリアミド樹脂組成物。
＜６＞他の酸化防止剤を含まないか、他の酸化防止剤の含有量が、リン系酸化防止剤の含有量の０．０１質量％以下である、＜１＞〜＜５＞のいずれか１つに記載の視認性タンク用ポリアミド樹脂組成物。
＜７＞前記リン系酸化防止剤が、式（２）で表される化合物および式（３）で表される化合物の少なくとも１種を含む、＜１＞〜＜６＞のいずれか１つに記載の視認性タンク用ポリアミド樹脂組成物；
式（２）

式（２）中、Ｒ¹〜Ｒ⁵は、それぞれ独立に、炭化水素基である；
式（３）

式（３）中、Ｒ⁶およびＲ⁷は、それぞれ独立に、炭化水素基である。
＜８＞２ｍｍの厚さに成形し、１３０℃の雰囲気下に１００時間置いた後の波長４８０ｎｍにおける透過率の保持率が６０％以上である、＜１＞〜＜７＞のいずれか１つに記載の視認性タンク用ポリアミド樹脂組成物。
＜９＞＜１＞〜＜８＞のいずれか１つに記載の視認性タンク用ポリアミド樹脂組成物から形成される視認性タンク。 Based on the above problems, it has been found that the above problems can be solved by using a phosphorus-based antioxidant having a predetermined structure in a resin composition containing a polyamide resin and an inorganic filler. Specifically, the above problem has been solved by the following means <1>, preferably <2> to <9>.
<1> The polyamide resin contains 40 to 100 parts by mass of an inorganic filler and 0.5 to 5.0 parts by mass of a phosphorous antioxidant with respect to 100 parts by mass of the polyamide resin. The polyamide resin includes a semi-aromatic polyamide resin and a fat. A polyamide resin composition for a visibility tank, which contains a group polyamide resin in a mass ratio of 95: 5 to 40:60, and wherein the phosphorus antioxidant contains two or more phosphorus atoms in the molecule.
<2> The semi-aromatic polyamide resin includes a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, and 50 mol% or more of the structural unit derived from diamine is a polyamide resin derived from xylylenediamine. The polyamide resin composition for a visibility tank described in 1.
<3> The polyamide resin composition for a visibility tank according to <1> or <2>, wherein the phosphorus-based antioxidant includes a structure represented by the following formula (1):
Formula (1)

In the above formula (1), * is a bonding position with another moiety, and ** is a bonding position with another moiety or a hydrogen atom.
<4> The polyamide resin composition for a visibility tank according to any one of <1> to <3>, wherein the phosphorus-based antioxidant contains two phosphorus atoms in the molecule.
<5> The visual recognition according to any one of <1> to <4>, wherein the content of the phosphorus-based antioxidant is 1.0 to 3.0% by mass of the polyamide resin composition for a visibility tank. Polyamide resin composition for water tank.
<6> Any of <1> to <5>, which does not contain other antioxidants, or the content of other antioxidants is 0.01% by mass or less of the content of phosphorus antioxidants The polyamide resin composition for visibility tanks as described in any one.
<7> In any one of <1> to <6>, wherein the phosphorus antioxidant includes at least one of a compound represented by formula (2) and a compound represented by formula (3) The polyamide resin composition for a visibility tank according to the description;
Formula (2)

In formula (2), R ^{1 to} R ⁵ are each independently a hydrocarbon group;
Formula (3)

In formula (3), R ⁶ and R ⁷ are each independently a hydrocarbon group.
<8> Any one of <1> to <7>, wherein the transmittance retention at a wavelength of 480 nm after being molded to a thickness of 2 mm and placed in an atmosphere at 130 ° C. for 100 hours is 60% or more The polyamide resin composition for a visibility tank described in 1.
<9> A visibility tank formed from the polyamide resin composition for a visibility tank according to any one of <1> to <8>.

  According to the present invention, it is possible to provide a polyamide resin composition capable of forming a visibility tank excellent in transparency after being placed in a high temperature atmosphere for a long time, and a visibility tank.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

The polyamide resin composition for a visibility tank of the present invention (hereinafter sometimes simply referred to as “resin composition of the present invention”) is 40 to 100 parts by mass of an inorganic filler and 100% by mass with respect to 100 parts by mass of the polyamide resin. 0.5 to 5.0 parts by mass of an antioxidant, and the polyamide resin contains a semi-aromatic polyamide resin and an aliphatic polyamide resin in a mass ratio of 95: 5 to 40:60, and the phosphorus series The antioxidant contains two or more phosphorus atoms in the molecule. By adopting such a configuration, it becomes possible to provide a visibility tank having excellent transparency after being placed in a high temperature atmosphere for a long time. In particular, it is possible to provide a visibility tank that is remarkably excellent in visibility in the visible region.
Mixing an antioxidant with a polyamide resin has been studied. However, as a result of studies by the present inventor, it has been difficult to achieve visibility with a phenol-based antioxidant or a sulfur-based antioxidant. In addition, even with phosphorus-based antioxidants, the visibility, particularly the transmittance in the visible region after being placed in a high-temperature atmosphere for a long time, that is, the transmittance in the visible region after aging treatment may vary. I understood. As a result of further various studies, it was found that by using a phosphorus-based antioxidant containing two or more phosphorus atoms in the molecule, the transmittance after aging treatment in the visible region can be kept specifically high, It has become possible to provide tanks with excellent visibility.

<Polyamide resin>
The resin composition of the present invention includes a semi-aromatic polyamide resin and an aliphatic polyamide resin. Each of the semi-aromatic polyamide resin and the aliphatic polyamide resin may be a crystalline polyamide resin or an amorphous polyamide resin, but a crystalline polyamide resin is preferred. The crystalline polyamide resin is generally inferior in transparency to the amorphous polyamide resin, so that the technical value used in the present invention is high.
The semi-aromatic polyamide resin is composed of a structural unit derived from a diamine and a structural unit derived from a dicarboxylic acid, and 30 to 70 mol% of the total structural unit of the structural unit derived from the diamine and the structural unit derived from the dicarboxylic acid has an aromatic ring. It is preferable that 40-60 mol% of the total structural unit of the structural unit derived from diamine and the structural unit derived from dicarboxylic acid is a structural unit containing an aromatic ring.

Among the semi-aromatic polyamide resins as described above, from the viewpoint of moldability and heat resistance, it contains a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, and 50 mol% or more of the structural unit derived from diamine is xylylenediamine. Is preferably a polyamide resin derived from (hereinafter, sometimes referred to as “XD-based polyamide”).
The ratio of the XD polyamide in the polyamide resin is preferably 50% by mass or more, and more preferably 80% by mass or more.

  XD-based polyamide is preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, particularly preferably 95 mol% or more of the structural unit derived from diamine. Preferably, the structural unit derived from xylylenediamine and derived from a dicarboxylic acid is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, still more preferably 90 mol%, still more preferably 95 mol. % Or more is derived from α, ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms.

Examples of diamines other than metaxylylenediamine and paraxylylenediamine that can be used as the raw material diamine component of the XD polyamide include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, and octanediamine. Aliphatic diamines such as methylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,3-bis (amino Methyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis ( -Aminocyclohexyl) propane, bis (aminomethyl) decalin, alicyclic diamines such as bis (aminomethyl) tricyclodecane, bis (4-aminophenyl) ether, paraphenylenediamine, fragrances such as bis (aminomethyl) naphthalene Examples include diamines having a ring, and one kind or a mixture of two or more kinds can be used.
When a diamine other than xylylenediamine is used as the diamine component, it is less than 50 mol% of the structural unit derived from diamine, preferably 30 mol% or less, more preferably 1 to 25 mol%, particularly preferably. Used in a proportion of 5 to 20 mol%.

  Preferred examples of the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms to be used as the raw material dicarboxylic acid component of the XD polyamide include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipine Examples include aliphatic dicarboxylic acids such as acid, sebacic acid, undecanedioic acid, and dodecanedioic acid, and one or a mixture of two or more can be used. Among these, the melting point of the polyamide resin is suitable for molding. Therefore, adipic acid or sebacic acid is preferable, and adipic acid is more preferable.

  Examples of the dicarboxylic acid component other than the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid and orthophthalic acid, 1,2-naphthalenedicarboxylic acid, 3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3- The isomers of naphthalenedicarboxylic acids such as naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid can be exemplified, and one or a mixture of two or more can be used.

  When a dicarboxylic acid other than an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms is used as the dicarboxylic acid component, terephthalic acid or isophthalic acid may be used from the viewpoint of molding processability and barrier properties. preferable. The proportion of terephthalic acid and isophthalic acid is preferably 30 mol% or less, more preferably 1 to 30 mol%, and particularly preferably 5 to 20 mol% of the dicarboxylic acid structural unit.

Furthermore, in addition to the diamine component and the dicarboxylic acid component, as components constituting the XD polyamide, lactams such as ε-caprolactam and laurolactam, fats such as aminocaproic acid, aminoundecanoic acid and the like as long as the effects of the present invention are not impaired. Group aminocarboxylic acids can also be used as copolymerization components.
For details of the XD polyamide, reference can be made to the description of paragraphs 0013 to 0025 of WO2016 / 080185, the contents of which are incorporated herein.
The XD polyamide used in the present invention contains trace components such as additives used in the synthesis. The polyamide resin used in the present invention is usually 95% by mass or more, preferably 98% by mass or more, and more preferably 99% by mass or more is a structural unit derived from dicarboxylic acid or a structural unit derived from diamine.

  Examples of the aliphatic polyamide resin in the present invention include polyamide 4, polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 6,66, polyamide 610, polyamide 612, and the like. Polyamide 6, polyamide 6,66 Polyamide 66 is preferable, and polyamide 66 is more preferable. The polyamide 6 here means a polyamide resin composed of a structural unit derived from ε-caprolactam, but does not depart from the gist of the present invention (for example, 5 mol% or less, further 3 mol% or less, particularly 1 And may contain structural units derived from other raw material monomers. The same applies to other aliphatic polyamides.

In the present invention, the polyamide resin includes a semi-aromatic polyamide resin and an aliphatic polyamide resin in a mass ratio (semi-aromatic polyamide resin: aliphatic polyamide resin) in a ratio of 95: 5 to 40:60, and 90:10 It is preferably included at a ratio of ˜40: 60, more preferably included at a ratio of 85:15 to 40:60, and still more preferably included at a ratio of 85:15 to 45:55.
The resin composition of the present invention may contain only one type of semi-aromatic polyamide resin and one type of aliphatic polyamide resin, or may contain two or more types. When 2 or more types are included, the total amount is preferably within the above range.

  The resin composition of the present invention preferably contains the polyamide resin in a proportion of 45% by mass or more of the composition in total, more preferably in a proportion of 50% by mass or more, and in a proportion of 55% by mass or more. May be. The upper limit of the content is preferably 80% by mass or less, more preferably 75% by mass or less, and further preferably 70% by mass or less.

<Inorganic filler>
The resin composition of the present invention contains an inorganic filler. The inorganic filler is preferably glass fiber.
A glass fiber consists of glass compositions, such as A glass, C glass, E glass, and S glass, and E glass (an alkali free glass) is especially preferable.

The glass fiber used for the resin composition of the present invention may be a single fiber or a single fiber twisted together.
The form of the glass fiber is “glass roving” obtained by continuously winding a single fiber or a plurality of twisted strands, “chopped strand” having a cut length (number average fiber length) of 1 to 10 mm, pulverization length ( Any of “milled fiber” having a number average fiber length) of 10 to 500 μm may be used. Such glass fibers are commercially available from Asahi Fiber Glass Co., Ltd. under the trade names “Glasslon Chopped Strand” and “Glasslon Milled Fiber”, and are easily available. Glass fibers having different forms can be used in combination.

  In the present invention, glass fibers having an irregular cross-sectional shape are also preferable. This irregular cross-sectional shape has a flatness indicated by a ratio of long diameter / short diameter (D2 / D1) where the long diameter of the cross section perpendicular to the fiber length direction is D2 and the short diameter is D1, for example, 1.5. It is preferable that it is 2.5-10, especially 2.5-8, especially 2.5-5. Regarding such flat glass, the description in paragraphs 0065 to 0072 of JP2011-195820A can be referred to, and the contents thereof are incorporated herein.

  The glass fiber used in the present invention is particularly preferably a glass fiber having a weight average fiber diameter of 1 to 20 μm and a cut length (number average fiber length) of 1 to 10 mm. Here, when the cross section of the glass fiber is flat, the weight average fiber diameter is calculated as a weight average fiber diameter in a circle having the same area.

  The inorganic filler in the present invention may be glass beads or glass flakes. The glass beads are spherical ones having an outer diameter of 10 to 100 μm, and are commercially available, for example, from Potters Barotini under the trade name “EGB731” and are easily available. Further, the glass flake is a flake shape having a thickness of 1 to 20 μm and a length of one side of 0.05 to 1 mm, and is commercially available, for example, under the trade name “Fureka” from Nippon Sheet Glass Co., Ltd. Are readily available.

The resin composition of this invention contains 40-100 mass parts of inorganic fillers with respect to 100 mass parts of polyamide resins. The lower limit of the content is preferably 42 parts by mass or more, and may be 50 parts by mass or more. The upper limit of the content is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, and may be 85 parts by mass or less.
The resin composition of this invention may contain only 1 type of the said inorganic filler, and may contain 2 or more types. When 2 or more types are included, the total amount is preferably within the above range.

上記式（１）中、＊は他の部位との結合位置であり、＊＊は他の部位との結合位置または水素原子である。
式（１）中、＊＊が水素原子の場合とは、式（１）において、ベンゼン環にｔ−ブチル基が置換している態様を意味する。以下、＊＊について、同様に考える。 <Phosphorus antioxidant>
The resin composition of the present invention contains a phosphorus-based antioxidant containing two or more phosphorus atoms in the molecule. The phosphorus-based antioxidant used in the present invention is a known phosphorus-based antioxidant, and compounds containing two or more phosphorus atoms in the molecule can be widely used. For example, the compounds represented by the formulas (1) to (5) described in JP 2012-117037 A are exemplified, and the contents thereof are incorporated in the present specification.
The phosphorus antioxidant preferably contains 2 to 7 phosphorus atoms in the molecule, more preferably 2 to 4, more preferably 2 or 3, and still more preferably 2 .
The phosphorus-based antioxidant used in the present invention preferably includes a structure represented by the following formula (1).
Formula (1)

In the above formula (1), * is a bonding position with another moiety, and ** is a bonding position with another moiety or a hydrogen atom.
The case where ** is a hydrogen atom in the formula (1) means an embodiment in which a t-butyl group is substituted on the benzene ring in the formula (1). Hereinafter, the same applies to **.

式（２）中、Ｒ¹〜Ｒ⁵は、それぞれ独立に、炭化水素基である。
Ｒ¹は、環状構造を含む炭化水素基であることが好ましく、アリーレン基を含む炭化水素基であることがより好ましく、−アリーレン基−アリーレン基−であることがさらに好ましく、ビフェニレン基であることが一層好ましい。
Ｒ²〜Ｒ⁵はそれぞれ独立に、アリール基であることが好ましく、フェニル基であることがより好ましい。アリール基は、置換基を有していてもよい。置換基としては、炭化水素基が例示され、アルキル基が好ましく、ｔ−ブチル基がより好ましい。特に、Ｒ²〜Ｒ⁵は、下記式で表されることが好ましい。

上記式中、＊は、式（２）の酸素原子との結合部位であり、＊＊は他の部位との結合位置または水素原子である。ｔ−ブチル基の末端の＊＊は水素原子またはフェニル基であることが好ましい。
式（２）で表される化合物は、分子量が６００〜１５００であることが好ましく、８００〜１２００であることがより好ましい。
式（３）

式（３）中、Ｒ⁶およびＲ⁷は、それぞれ独立に、炭化水素基である。
Ｒ⁶およびＲ⁷は、アリール基であることが好ましく、フェニル基であることがより好ましい。アリール基は、置換基を有していてもよい。置換基としては、炭化水素基が例示され、アルキル基が好ましく、ｔ−ブチル基がより好ましい。特に、Ｒ⁶およびＲ⁷は、下記式で表されることが好ましい。

上記式中、＊は、式（３）の酸素原子との結合部位であり、＊＊は他の部位との結合位置または水素原子である。ｔ−ブチル基の末端の＊＊は水素原子または炭化水素基（好ましくはアリール基、より好ましくはフェニル基）であることが好ましい。
式（３）で表される化合物は、分子量が４００〜１５００であることが好ましく、５００〜１２００であることがより好ましい。 The phosphorus-based antioxidant used in the present invention more preferably contains at least one of the compound represented by the formula (2) and the compound represented by the formula (3).
Formula (2)

In formula (2), R ^{1 to} R ⁵ are each independently a hydrocarbon group.
R ¹ is preferably a hydrocarbon group containing a cyclic structure, more preferably a hydrocarbon group containing an arylene group, more preferably an -arylene group-arylene group-, and a biphenylene group. Is more preferable.
R ^{2 to} R ⁵ are each independently preferably an aryl group, and more preferably a phenyl group. The aryl group may have a substituent. Examples of the substituent include a hydrocarbon group, an alkyl group is preferable, and a t-butyl group is more preferable. In particular, R ^{2 to} R ⁵ are preferably represented by the following formula.

In the above formula, * is a bonding site with the oxygen atom of formula (2), and ** is a bonding position with another site or a hydrogen atom. ** at the terminal of the t-butyl group is preferably a hydrogen atom or a phenyl group.
The compound represented by the formula (2) preferably has a molecular weight of 600 to 1500, and more preferably 800 to 1200.
Formula (3)

In formula (3), R ⁶ and R ⁷ are each independently a hydrocarbon group.
R ⁶ and R ⁷ are preferably aryl groups, and more preferably phenyl groups. The aryl group may have a substituent. Examples of the substituent include a hydrocarbon group, an alkyl group is preferable, and a t-butyl group is more preferable. In particular, R ⁶ and R ⁷ are preferably represented by the following formula.

In the above formula, * is a bonding site with the oxygen atom of formula (3), and ** is a bonding position with another site or a hydrogen atom. The terminal ** of the t-butyl group is preferably a hydrogen atom or a hydrocarbon group (preferably an aryl group, more preferably a phenyl group).
The compound represented by the formula (3) preferably has a molecular weight of 400 to 1500, and more preferably 500 to 1200.

The resin composition of the present invention contains 0.5 to 5.0 parts by mass of the phosphorus-based antioxidant with respect to 100 parts by mass of the polyamide resin. The lower limit of the content is preferably 1.0 part by mass or more, more preferably 1.5 parts by mass or more, and may be 2.0 parts by mass or more. The upper limit of the content is preferably 4.0 parts by mass or less, more preferably 3.0 parts by mass or less, and may be 2.7 parts by mass or less.
Moreover, it is preferable that content of the said phosphorus antioxidant is 1.0-3.0 mass% of the polyamide resin composition for visibility tanks, and the resin composition of this invention is 1.0-2. More preferably, it is 5 mass%. By setting it as such a compounding quantity, it exists in the tendency for transparency to improve more.
The resin composition of this invention may contain only 1 type of the said phosphorus antioxidant, and may contain 2 or more types. When 2 or more types are included, the total amount is preferably within the above range.

<Other antioxidants>
The resin composition of the present invention comprises a phosphorus-based antioxidant other than a phosphorus-based antioxidant containing two or more phosphorus atoms in the molecule, and other antioxidants (a sulfur-based antioxidant, a phenol-based antioxidant). Etc.) may or may not be included.
As one embodiment of the resin composition of the present invention, a resin containing another antioxidant (sulfur-based antioxidant, phenol-based antioxidant, etc.) at a ratio of 1 to 10 parts by mass with respect to 100 parts by mass of polyamide resin. Compositions are exemplified.
As another embodiment of the resin composition of the present invention, other antioxidants are not included, or the content of other antioxidants is 0.01% by mass or less of the content of phosphorus antioxidants. A certain resin composition is exemplified. By setting it as such a structure, the resin composition with a higher transmittance | permeability retention after the aging process in wavelength 480nm is obtained.

<Other ingredients>
The resin composition of the present invention may contain other components without departing from the spirit of the present invention. Examples of such additives include thermoplastic resins other than polyamide resins, flame retardants, ultraviolet absorbers, fluorescent brighteners, anti-dripping agents, antistatic agents, antifogging agents, lubricants, antiblocking agents, and fluidity. Examples include improvers, plasticizers, dispersants, and antibacterial agents. These components may use only 1 type and may use 2 or more types together.

<Characteristics of resin composition>
The resin composition of the present invention has a transmittance of 15% or more (preferably 16% or more, preferably an upper limit) after being molded to a thickness of 2 mm and placed in an atmosphere of 130 ° C. for 100 hours at a wavelength of 480 nm. For example, the resin composition may be 50% or less, and further 45% or less.
The resin composition of the present invention has a transmittance retention of 60% or more (preferably 63% or more, more preferably, after being molded to a thickness of 2 mm and placed in an atmosphere of 130 ° C. for 100 hours at a wavelength of 480 nm. 67% or more, more preferably 70% or more, and the upper limit is not particularly defined. For example, the resin composition can be 100% or less, and further 95% or less.

<Application>
The resin composition of the present invention can be used to form a visibility tank in a wide range of applications such as the automobile field, shipbuilding field, railway field, electrical and electronic field, sundries field, civil engineering field, and food field. That is, this invention also discloses the visibility tank formed from the polyamide resin composition for visibility tanks of this invention. Specific examples of the visibility tank include a fuel tank, an expansion tank, a water supply tank, a brewing tank, a tank built in a pump, and the like. The storage target of the tank is not particularly defined, but is particularly preferably used as a tank containing water, LLC (long life coolant), gas (air, nitrogen gas, etc.) as contents.

  The tank of the present invention may have a cap, a handle, a joint with another tank or a part, and the like. These parts may be formed from a composition having the same composition as the resin composition of the present invention, or may be formed from other resin materials. Moreover, you may form from materials other than resin.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

<Synthesis example of polyamide resin MP10>
In a reaction vessel equipped with a stirrer, a partial condenser, a full condenser, a thermometer, a dropping funnel and a nitrogen introducing tube, and a strand die, 12,135 g (60 mol) of sebacic acid precisely weighed, sodium hypophosphite monohydrate Product (NaH ₂ PO ₂ .H ₂ O) (3,105 g (phosphorus atom concentration in the polyamide resin as 50 ppm by mass)) and sodium acetate (1.61 g) were sufficiently substituted with nitrogen, and then under a small amount of nitrogen stream The system was heated to 170 ° C. with stirring. The molar ratio of sodium acetate / sodium hypophosphite monohydrate was 0.67.
To this, 8.172 g (60 mol) of a 7: 3 mixed diamine of metaxylylenediamine and paraxylylenediamine was added dropwise with stirring, and the inside of the system was continuously heated while removing the condensed water formed outside the system. . After completion of the dropwise addition of the mixed metaxylylenediamine, the melt polymerization reaction was continued for 40 minutes at an internal temperature of 260 ° C.
Thereafter, the inside of the system was pressurized with nitrogen, the polymer was taken out from the strand die, and pelletized. The melting point of the obtained polyamide resin (MP10) was 215 ° C.

Polyamide resin A-1: MP10, semi-aromatic polyamide resin A-2: metaxylylene adipamide, MXD6, manufactured by Mitsubishi Gas Chemical Co., Ltd., 6000, semi-aromatic polyamide resin A-3: nylon 66, Solvay Stabamid 26AE1K, aliphatic polyamide resin

Inorganic filler B-1: T-756H, manufactured by Nippon Electric Glass Co., Ltd., ECS03T-756H, weight average fiber diameter 10.5 μm, cut length 3 mm
B-2: T-289H, manufactured by Nippon Electric Glass Co., Ltd., ECS03T-289H, weight average fiber diameter 10 μm, cut length 3 mm

Phosphorous antioxidants:
C-1: PEP-Q, manufactured by BASF

C-2: PEP-36, manufactured by ADEKA

C-3: S9228, manufactured by Dober Chemical Corporation

C-4: Irgafos 168, manufactured by BASF

Other antioxidants D-1: Irganox 1010, phenolic antioxidants, BASF D-2: Sumilizer TP-D, sulfur antioxidants, Sumitomo Chemical

Example 1
<Compound of resin composition>
Each component is weighed and blended so as to have the composition shown in Table 1 described later (the amount of each component in the table is part by mass), and the basis of a twin screw extruder (Toshiki Machine Co., Ltd., TEM26SS). And melted to obtain resin composition pellets. The set temperature of the extruder was 280 ° C.

<Transmissivity>
After drying the pellet obtained by the above-mentioned manufacturing method at 120 ° C. for 5 hours, using Nissei Plastic Industries, SG75-MII, conditions of cylinder temperature 280 ° C., mold temperature 130 ° C., molding cycle 50 seconds And a plate having a thickness of 60 mm × 60 mm and a thickness of 2 mm was formed.
About the obtained plate, the transmittance | permeability (unit:%) in wavelength 800nm and 480nm was measured using the visible and ultraviolet spectrophotometer (the Shimadzu Corporation make, UV-3100PC), respectively.
Further, after the obtained plate was placed in an atmosphere of 130 ° C. for 100 hours (aging treatment), the transmittance was measured in the same manner.
Furthermore, the transmittance retention after the aging treatment was calculated.

Examples 2-8, Comparative Examples 1-4
In Example 1, the composition of the resin composition was changed as shown in Table 1, and the others were performed in the same manner.

As is clear from the above results, the resin composition of the present invention had high visibility (Examples 1 to 8). In particular, when the wavelength is 800 nm, the transmittance, the transmittance after the aging treatment, and the retention rate are compared with the resin composition of the present invention or without adding an antioxidant (Comparative Example 4). Even when a phosphorus-based antioxidant outside the scope of the present invention was blended (Comparative Examples 1 to 3), no significant difference was observed. Rather, a difference in effect was recognized depending on whether or not an antioxidant other than phosphorus was added.
On the other hand, when the wavelength was 480 nm, a significant difference was observed in the retention after the aging treatment between the resin composition of the present invention and the resin composition of the comparative example. The visibility tank is highly valuable in that a composition having a high transmittance retention after aging treatment in the visible region is obtained because the transmittance in the visible region is important.

Claims (9)

Including 100-100 parts by mass of polyamide resin, 40-100 parts by mass of inorganic filler and 0.5-5.0 parts by mass of phosphorous antioxidant,
The polyamide resin includes a semi-aromatic polyamide resin and an aliphatic polyamide resin in a mass ratio of 95: 5 to 40:60,
A polyamide resin composition for a visibility tank, wherein the phosphorus antioxidant contains two or more phosphorus atoms in the molecule. The semi-aromatic polyamide resin includes a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, and 50 mol% or more of the structural unit derived from diamine is a polyamide resin derived from xylylenediamine. A polyamide resin composition for a visibility tank. The polyamide resin composition for a visibility tank according to claim 1 or 2, wherein the phosphorus antioxidant includes a structure represented by the following formula (1):
Formula (1)

In the above formula (1), * is a bonding position with another moiety, and ** is a bonding position with another moiety or a hydrogen atom. The visibility resin tank polyamide resin composition of any one of Claims 1-3 in which the said phosphorus antioxidant contains two phosphorus atoms in a molecule | numerator. The polyamide resin for a visibility tank according to any one of claims 1 to 4, wherein the content of the phosphorus-based antioxidant is 1.0 to 3.0 mass% of the polyamide resin composition for a visibility tank. Composition. The other antioxidant is not contained, or the content of the other antioxidant is 0.01% by mass or less of the content of the phosphorus-based antioxidant, according to any one of claims 1 to 5. Polyamide resin composition for visibility tanks. The visibility tank of any one of Claims 1-6 in which the said phosphorus antioxidant contains at least 1 sort (s) of the compound represented by Formula (2), and a compound represented by Formula (3). Polyamide resin composition;
Formula (2)

In formula (2), R ^{1 to} R ⁵ are each independently a hydrocarbon group;
Formula (3)

In formula (3), R ⁶ and R ⁷ are each independently a hydrocarbon group. The visibility according to any one of claims 1 to 7, wherein the transmittance retention at a wavelength of 480 nm after being molded to a thickness of 2 mm and placed in an atmosphere at 130 ° C for 100 hours is 60% or more. Polyamide resin composition for tanks. The visibility tank formed from the polyamide resin composition for visibility tanks of any one of Claims 1-8.