JP2009073948A - Thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin composition from which a molded article having excellent cold shock resistance in addition to high stiffness and heat resistance can be produced, and which is applicable even to ethanol-containing fuel system parts. <P>SOLUTION: The thermoplastic resin composition comprises a polyamide resin (A) having an intrinsic viscosity measured in concentrated sulfuric acid at 25°C in a range of 1.0-3.0 dl/g, a melting point of 300-340°C and a glass transition temperature of ≥80°C, and a carboxylic acid-modified ethylene/α-olefin copolymer (B) having an ethylene content of 70-95 mol% and a glass transition temperature of ≤-20°C, wherein the resin composition has a content of the polyamide resin (A) in a range of 70-100 mass% and a content of the carboxylic acid-modified ethylene/α-olefin copolymer (B) in a range of 0-30 mass%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition excellent in low-temperature impact property and a molded product thereof in addition to the characteristics of polyamide resin, particularly semi-aromatic polyamide resin, which have high rigidity and heat resistance. Furthermore, the present invention relates to a thermoplastic resin composition useful as a molded article for an ethanol-containing fuel system, which is attracting attention as a countermeasure against global warming, and a thermoplastic resin composition containing the composition.

  Polyamide resin has excellent heat resistance, oil resistance, moldability, rigidity, toughness, etc., so power tools, general industrial parts, machine parts, electronic parts, automotive interior and exterior parts, fuel system parts, Expansion to various functional parts such as automobile electrical parts is being attempted.

  However, since the aliphatic polyamide resin has a high water absorption rate, a molded article formed of such an aliphatic polyamide has a problem that dimensions and physical properties greatly vary due to water absorption.

  On the other hand, the aromatic polyamide resin is a polyamide obtained by polycondensing an aromatic dicarboxylic acid and a diamine using an aromatic dicarboxylic acid as a dicarboxylic acid component. Aromatic polyamide resins, unlike aliphatic polyamide resins, have a low water absorption rate. Therefore, the use of aromatic polyamide resins reduces the dimensional accuracy and physical properties of the molded products as described above due to water absorption. Problems such as fluctuations are eliminated. Further, since this aromatic polyamide generally has a higher melting point than aliphatic polyamide, it has an advantage of excellent heat resistance.

  However, when the molded article formed from the aromatic polyamide resin is examined in more detail, there is a problem that the toughness such as elongation and impact resistance is low as compared with the molded article formed from the aliphatic polyamide resin.

  A semi-aromatic polyamide resin has a characteristic that is a good mix of the characteristics of an aliphatic polyamide resin and an aromatic polyamide resin, but the impact resistance is not satisfactory. In order to improve the impact resistance of the aromatic polyamide resin, it is already known to add a modified α-olefin elastomer, and various improvements have been attempted with respect to the semi-aromatic polyamide.

In recent years, global warming has become a problem, and ethanol-containing gasoline is in the spotlight as a countermeasure. Development of fuel system parts corresponding to ethanol-containing gasoline is being made accordingly, but polyamide resin is also a focus as a material due to its heat resistance and other characteristics. However, it is unclear whether the polyamide composition disclosed herein has sufficient low-temperature impact resistance as an automotive part. In addition, it is not yet known what composition ratios are desirable for ethanol-containing fuel system parts.
JP 05-009381 A JP 2004-217698 A

  The present invention provides a thermoplastic resin composition capable of producing a molded article having excellent low-temperature impact properties in addition to the characteristics of high rigidity and heat resistance, and can be adapted as an ethanol-containing fuel system component. It is an object.

  As a result of intensive studies to solve the above problems, the inventor has identified a carboxylic acid-modified ethylene / α-olefin copolymer having a specific composition as needed for a polyamide having a specific composition and physical properties. By mixing at a ratio, it was found that excellent low-temperature impact properties were obtained, and that ethanol-containing gasoline was also resistant, and the present invention was completed.

  That is, the present invention relates to 50 to 99 mol% of terephthalic acid component units and 1 to 50 mol% of aromatic dicarboxylic acid component units other than terephthalic acid and / or 1 to 50 aliphatic dicarboxylic acid component units having 4 to 18 carbon atoms. A polyamide resin composed of a repeating unit consisting of a dicarboxylic acid component unit composed of mol% and a diamine component unit composed of an aliphatic diamine component unit and / or an alicyclic diamine component unit, and concentrated in 25 ° C. concentrated sulfuric acid A polyamide resin (A) having an intrinsic viscosity measured in the range of 1.0 to 3.0 dl / g, a melting point of 300 to 340 ° C., and a glass transition temperature of 80 ° C. or higher, and an ethylene content of A tree comprising a carboxylic acid-modified ethylene / α-olefin polymer (B) having a glass transition temperature of −20 ° C. or lower and having a content of 70 to 95 mol% The composition is characterized in that the content of the polyamide (A) is in the range of 70 to 100% by mass and the content of the carboxylic acid-modified ethylene / α-olefin copolymer (B) is in the range of 0 to 30% by mass. And a molded article for an ethanol-containing fuel system containing the composition.

  The thermoplastic resin composition of the present invention is excellent in low-temperature impact properties in addition to the high rigidity and heat resistance of polyamides, particularly semi-aromatic polyamides. Furthermore, the present invention has resistance to an ethanol-containing fuel that has been attracting attention as a countermeasure against global warming, and as a raw material resin composition used for a molded article for an ethanol-containing fuel system, and also an ethanol-containing fuel It is very useful as a molding for a system.

Below, the thermoplastic resin composition of this invention is demonstrated concretely.
[Polyamide (A)]
The polyamide resin (A) of the present invention comprises a dicarboxylic acid component unit and an aliphatic diamine component unit.

[Dicarboxylic acid component unit]
The dicarboxylic acid component unit constituting the polyamide resin (A) used in the present invention is a terephthalic acid component unit of 50 to 100 mol%, an aromatic polyfunctional carboxylic acid component unit other than terephthalic acid unit of 0 to 50 mol%, and / or It is preferable that it is 0-50 mol% of C4-C20 aliphatic polyfunctional carboxylic acid component units, and the total amount of these dicarboxylic acid component units is 100 mol%. Among these, examples of the aromatic carboxylic acid component unit other than terephthalic acid include isophthalic acid, 2-methylterephthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, and the like, and among these, isophthalic acid is particularly preferable. These may be used alone or in combination of two or more. If a trifunctional or higher polyfunctional compound such as trimellitic acid or pyromellitic acid is used, it is added in such an amount that the resin does not gel, specifically 5 in 100 mol% of the total carboxylic acid component units. It is necessary to make it less than mol%.

  Moreover, when introducing an aliphatic dicarboxylic acid component, it is derived from an aliphatic polyfunctional carboxylic acid compound having 4 to 20, preferably 6 to 12, and more preferably 6 to 10 carbon atoms. Examples of such compounds include adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid and the like. Among these, adipic acid is particularly preferable from the viewpoint of improving mechanical properties. In addition to this, a polyfunctional carboxylic acid compound having three or more functional groups can be used as needed, but the addition amount should be such that the resin does not gel. Specifically, the total carboxylic acid component It is necessary to make it 5 mol% or less in the total 100 mol% of the unit.

  In the present invention, when the total amount of dicarboxylic acid component units is 100 mol%, the terephthalic acid component units are 50 to 100 mol%, preferably 55 to 90 mol%, more preferably 60 to 70 mol%. The aromatic polyfunctional carboxylic acid component unit other than terephthalic acid is preferably contained in an amount of 0 to 50 mol%, preferably 0 to 25 mol%, and more preferably 0 to 10 mol%. When the amount of the aromatic polyfunctional carboxylic acid component increases, the amount of moisture absorption decreases and the heat resistance tends to improve. In addition, the amount of aromatic dicarboxylic acid component other than terephthalic acid tends to increase the mechanical properties, particularly toughness, of the molded product because the crystallinity of the polyamide resin increases as the content decreases. Further, the aliphatic polyfunctional carboxylic acid component unit having 4 to 20 carbon atoms is preferably contained in an amount of 0 to 50 mol%, preferably 30 to 50 mol%, more preferably 30 to 40 mol%. .

[Diamine component unit]
The diamine component unit constituting the polyamide resin (A) used in the present invention has 4 to 20 carbon atoms, preferably 6 to 12, more preferably 6 to 10 carbon atoms, having a straight chain and / or a side chain. A diamine component unit is mentioned, and the total amount of these polyfunctional amine component units is 100 mol%.

  Specific examples of the linear polyfunctional amine component unit include 1,4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, , 10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane. Among these, 1,6-diaminohexane is preferable.

  Specific examples of the linear aliphatic diamine component unit having a side chain include 2-methyl-1,5-diaminopentane, 2-methyl-1,6-diaminohexane, 2-methyl-1,7. -Diaminoheptane, 2-methyl-1,8-diaminooctane, 2-methyl-1,9-diaminononane, 2-methyl-1,10-diaminodecane, 2-methyl-1,11-diaminoundecane, etc. . Among these, 2-methyl-1,5-diaminopentane and 2-methyl-1,8-diaminooctane are preferable.

  When using a trifunctional or more polyfunctional compound, it is necessary to add it so that the resin does not gel, specifically, 5 mol% or less in a total of 100 mol% of all amine component units.

[Polyamide resin (A)]
In producing the polyamide resin (A) used in the present invention, any known method can be employed.

  The polyamide resin (A) of the present invention has an intrinsic viscosity [η] measured at a temperature of 25 ° C. in 96.5% sulfuric acid of 1.0 to 3.0 dl / g, preferably 1.2 to 2.5 dl / g. More preferably, it is 1.5-2.0. When [η] is within this range, it is possible to obtain a polyamide resin that has high toughness as well as impact resistance and heat resistance and can be applied to an ethanol-containing fuel.

  Further, the polyamide resin (A) used in the present invention has a melting point because it is crystalline, and the polyamide resin obtained by the above production method is 10 ° C./min using a differential scanning calorimeter (DSC). When the endothermic peak based on melting when the temperature is raised is measured as the melting point (Tm), it is preferably 280 to 340 ° C, particularly preferably 300 to 340 ° C, and more preferably 300 to 330 ° C.

  Furthermore, the glass transition temperature (Tg) of the polyamide resin (A) used in the present invention is 80 ° C. or higher, preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and the temperature range is 80 to 180 ° C., preferably Is 100 to 170 ° C, more preferably 120 to 150 ° C.

  The terminal amino group concentration is not particularly limited, but is preferably 5 to 600 ppm, more preferably 10 to 300 ppm. The terminal amino group concentration was determined by dissolving 0.5 g of a sample in 30 ml of a metacresol solvent at 110 ° C. for 30 minutes and titrating with 0.02 mol / l paratoluenesulfonic acid. This is based on the colorimetric method in which the density of the point changed to is obtained by calculation.

  A preferred polyamide resin (A) in the present invention is a PA6T copolymer having 2 to 4 components having the above-mentioned properties. These may be used singly or as a mixture of two or more. It is desirable that the aromatic ratio of the polyamide resin (A) as a whole is 20 mol% or more, preferably 25 mol% or more, more preferably 30 mol% or more.

  Specific examples of the polyamide resin (A) in the present invention include 6T / DT, 6T / 6I, 6T / DT / 66, 6T / 6I / 66, 6T / DT / 6I, 6T / DT / 66 / D6, 9T, 10T / 106 and the like. (The above symbols indicate the component structure of the polyamide resin (A). For example, in the case of a polyamide resin of 6T / DT / 66, a copolymer composed of three components is shown, and the breakdown of the components is 6T. The part is composed of a polyamide component composed of 1,6-diaminohexane (6) and terephthalic acid (T), and the DT part is composed of 2-methyl-1,5-diaminopentane (D) and terephthalic acid (T). 66 parts indicate polyamide composed of 1,6-diaminohexane (6) and adipic acid (6), and represents a polyamide resin composed of these three components. I represents isophthalic acid, 9 represents 1,9 diaminononane, and 10 represents 1,10-diaminodecane.)

[Ethylene / α-olefin copolymer (B)]
The carboxylic acid-modified ethylene / α-olefin polymer (B) of the present invention is a carboxylic acid-modified product of a copolymer in which ethylene units and α-olefin units are randomly arranged. The carboxylic acid-modified ethylene / α-olefin copolymer is a low crystallinity or amorphous copolymer, and is preferably substantially amorphous. That is, the crystallinity measured by the X-ray diffraction method is 10% or less, preferably 5% or less, and particularly preferably 0%. Therefore, many of these carboxylic acid-modified ethylene / α-olefin copolymers do not exhibit a clear melting point. Further, since the crystallinity is low, the carboxylic acid-modified ethylene / α-olefin random copolymer is soft, and the tensile modulus of the polymer is usually 0.1 kg / cm 2 or more and less than 20000 kg / cm 2, Preferably it exists in the range of 1 kg / cm <2> -15000 kg / cm <2>.

  The melt index (measured at 190 ° C.) of the carboxylic acid-modified ethylene α-olefin copolymer is usually 0.1 to 30 g / 10 min, preferably 1.0 to 20 g / 10 min, particularly preferably 2 Within the range of 0.0-15 g / 10 min. Further, the value of Mw / Mn measured by GPC is usually 5.5 or less, preferably 4.5 or less, particularly preferably 3.5 or less.

  Furthermore, the glass transition temperature (Tg) of the carboxylic acid-modified ethylene α-olefin copolymer is usually −20 ° C. or lower, preferably −40 ° C. or lower, and the range is −200 to −20 ° C., preferably Is in the range of −100 to −20 ° C., more preferably −100 to −40 ° C., still more preferably −80 to −50 ° C.

  The intrinsic viscosity [η] measured in decalin at 135 ° C. of this carboxylic acid-modified ethylene α-olefin copolymer is usually in the range of 0.2 to 10 dl / g, preferably 1 to 5 dl / g. The density is usually in the range of 0.80 to 0.90 g / cm @ 3, preferably 0.85 to 0.88 g / cm @ 3.

  As the α-olefin constituting the carboxylic acid-modified ethylene / α-olefin copolymer, an α-olefin having 3 to 10 carbon atoms is usually used. Examples of the α-olefin include propylene, butene -1, pentene-1, hexene-1, 4-methylpentene-1, octene-1, decene-1 and mixtures thereof. Of these, propylene, 1-butene, and 1-octene are preferable.

  In the carboxylic acid-modified ethylene / α-olefin copolymer as described above, the molar ratio of ethylene to α-olefin (ethylene / α-olefin) varies depending on the type of α-olefin, but generally 10/90 To 99/1, preferably 50/50 to 95/5. The molar ratio is preferably 50/50 to 90/10 when the α-olefin is propylene, and 80/20 when the α-olefin is an α-olefin having 4 or more carbon atoms. It is preferable that it is -95/5.

  This ethylene α-olefin copolymer contains component units other than the component units derived from α-olefin, such as component units derived from a diene compound, within the range not impairing the characteristics of the present invention. Also good.

  Examples of component units allowed to be contained in the ethylene α-olefin copolymer include 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, and 6-methyl-1 Component units derived from chain non-conjugated dienes such as 1,5-heptadiene and 7-methyl-1,6-octadiene; cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2 Component units derived from cyclic non-conjugated dienes such as -norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene and 6-chloromethyl-5-isopropenyl-2-norbornene; 2,3 Component derived from diene compounds such as 2-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene and 2-propenyl-2,2-norbornadiene As well as component units derived from cyclic olefins. The content of the diene component unit as described above in the α-olefin random elastic copolymer is usually 10 mol% or less, preferably 5 mol% or less.

  Examples of ethylene / α-olefin copolymers that form such carboxylic acid-modified α-olefin random copolymers include ethylene / propylene copolymers, ethylene / butene-1 copolymers, and ethylene / 4-methyl. Two-component copolymers such as pentene-1 copolymer, ethylene / hexene-1 copolymer, ethylene / octene-1 copolymer and ethylene / decene-1 copolymer; ethylene / propylene / 1, 4-hexadiene copolymer, ethylene-propylene-dicyclopentadiene copolymer, ethylene-propylene-5-ethylidene-2-norbornene copolymer, ethylene-propylene-2,5-norbornadiene copolymer, ethylene-butene- 1-dicyclopentadiene copolymer, ethylene-butene-1,1,4-hexadiene copolymer and ethylene-butene-1,5-ethylidene-2-norbornene copolymer A multi-component copolymer such as a polymer can be exemplified.

[Carboxylic acid modification]
The carboxylic acid-modified ethylene α-olefin copolymer used in the present invention is an unmodified ethylene α-olefin copolymer having the above composition (ratio), which is an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or It is formed by graft modification using an unsaturated carboxylic acid derivative as a modifier.

  Examples of unsaturated carboxylic acids used here include acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocis-bicyclo [2.2.1] Hept-5-ene-2,5-dicarboxylic acid (nadic acid TM) and methyl-endocis-bicyclo [2.2.1] hept-5-ene-2,5-dicarboxylic acid (methyl nadic acid TM) ). In addition, preferable examples of the unsaturated carboxylic acid anhydride include maleic anhydride, citraconic anhydride, nadic anhydride, and methyl nadic anhydride. Further, unsaturated carboxylic acid derivatives include acid halide compounds of the above unsaturated carboxylic acids (eg maleyl chloride), imide compounds (eg maleimide), ester compounds (eg monomethyl maleate, dimethyl maleate and glycidyl maleate). E)).

  The above modifiers can be used alone or in combination. Among such modifiers, it is preferable to use an unsaturated carboxylic acid anhydride, and maleic anhydride or nadic anhydride TM is particularly preferable.

  Examples of a method for graft polymerization of the above-mentioned graft modifier to an unmodified ethylene α-olefin copolymer include suspension or solution of an ethylene α-olefin copolymer suspended or dissolved in a solvent. Include a method of adding a graft modifier to a graft reaction (solution method) and a method of performing a graft reaction while melting a mixture of an ethylene α-olefin copolymer and a graft modifier (melting method). it can.

  In such a graft reaction, the amount of the graft modifier is set in consideration of its reactivity, but generally 1 to 10 parts by weight per 100 parts by weight of the unmodified ethylene α-olefin copolymer. Used in an amount in the range of parts by weight.

  By carrying out the graft reaction in this way, the graft modifier is usually grafted at a ratio of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight per 100 parts by weight of the unreacted ethylene α-olefin copolymer. A graft-modified ethylene α-olefin copolymer in which a modifier is graft-polymerized can be obtained.

  In addition, when performing such a graft reaction, graft efficiency can be improved by using a radical initiator. As the radical initiator used here, known radical initiators such as organic peroxides, organic peresters, and azo compounds can be used. When a radical initiator is used, the amount used is usually 0.01 to 20 parts by weight with respect to 100 parts by weight of the unmodified ethylene α-olefin copolymer.

  In the present invention, among the modified ethylene α-olefin copolymers as described above, the ethylene content is 35 to 50 mol%, and the amorphous carboxylic acid-modified ethylene / α-olefin random copolymer rubber is substantially amorphous. By using, a molded article having excellent toughness can be obtained.

[Flame retardants]
In the present invention, a flame retardant may be used as necessary. The flame retardant is added for the purpose of lowering the flammability of the resin. The flame retardant polyamide composition of the present invention is thermally stable at the time of molding at a temperature of 280 ° C. or more, flame retardancy, fluidity, In order to provide heat resistance and toughness equivalent to or better than 46 nylon, it is necessary to use a phosphinate.

As the phosphinate used in the present invention,
The phosphinic acid salt which is the flame retardant (B) used in the present invention can be easily obtained from the market, and examples thereof include:

  The flame retardant may be added at a rate of 5 to 40% by mass, preferably 10 to 20% by mass, with respect to 100% by mass of the thermoplastic resin composition.

[Flame retardant aid]
In the present invention, a flame retardant aid may be used as necessary. Any flame retardant aid may be used as long as it is used in combination with a flame retardant to significantly enhance the flame retarding action, and known ones can be used. Specifically, antimony compounds such as antimony trioxide, antimony tetroxide, antimony pentoxide, and sodium antimonate, 2ZnO · 3B ₂ O ₃ , 4ZnO · B ₂ O ₃ · H ₂ O, 2ZnO · 3B ₂ O ₃ · Examples thereof include zinc borate, zinc stannate, zinc phosphate, calcium borate, calcium molybdate and the like as listed in 3.5H ₂ O, and these may be used alone or in combination of two or more. . Among these, sodium antimonate, zinc borate, and zinc phosphate are preferable, and sodium antimonate and zinc borate anhydrides, that is, 2ZnO.3B ₂ O ₃ are more preferable.

  The flame retardant aid is added at a ratio of 0.1 to 20% by mass, further 0.5 to 15% by mass, more preferably 1 to 10% by mass with respect to 100% by mass of the thermoplastic resin composition of the present invention. May be.

[Reinforcement material]
In the present invention, a reinforcing material may be used as necessary, and as the reinforcing material, various inorganic fillers having shapes such as a fiber shape, a powder shape, a granular shape, a plate shape, a needle shape, a cloth shape, and a mat shape are used. can do. More specifically, powders such as silica, silica alumina, alumina, calcium carbonate, titanium dioxide, talc, wollastonite, diatomaceous earth, clay, kaolin, spherical glass, mica, gypsum, red pepper, magnesium oxide and zinc oxide Plate-like inorganic compounds, needle-like inorganic compounds such as potassium titanate, glass fiber (glass fiber), potassium titanate fiber, metal-coated glass fiber, ceramic fiber, wollastonite, carbon fiber, metal carbide fiber, metal cured Inorganic fibers such as physical fibers, asbestos fibers and boron fibers, and organic fibers such as aramid fibers and carbon fibers. As such a fibrous filler, glass fiber is particularly preferable. By using glass fiber, the moldability of the composition is improved, and mechanical properties such as tensile strength, bending strength, bending elastic modulus, and heat distortion temperature of the molded body formed from the thermoplastic resin composition, etc. Heat resistance is improved. The average length of the glass fibers as described above is usually in the range of 0.1 to 20 mm, preferably 0.3 to 6 mm, and the aspect ratio (L (average length of fibers) / D (average of fibers) The outer diameter)) is usually in the range of 10 to 5000, preferably 2000 to 3000. It is preferable to use glass fibers having an average length and an aspect ratio within such ranges.

  Two or more kinds of these fillers can be mixed and used. Further, these fillers can be used after being treated with a silane coupling agent or a titanium coupling agent. For example, the surface treatment may be performed with a silane compound such as vinyltriethoxysilane, 2-aminopropyltriethoxysilane, or 2-glycidoxypropyltriethoxysilane.

  Further, the fibrous filler may be coated with a sizing agent, and is preferably an acrylic, acrylic / maleic acid modified, epoxy, urethane, urethane / maleic acid modified, urethane / amine modified compound. used. The surface treatment agent may be used in combination with the sizing agent, and by using in combination, the binding between the fibrous filler in the composition of the present invention and other components in the composition is improved, and the appearance and strength are improved. Improved characteristics.

  These reinforcing materials may be added at a ratio of 0 to 60% by mass, preferably 10 to 50% by mass, more preferably 20 to 45% by mass with respect to 100% by mass of the thermoplastic resin composition of the present invention. good.

[Other additives]
The thermoplastic resin composition of the present invention is a heat stabilizer, weathering stabilizer, fluidity improver, plasticizer, thickening agent other than the above as long as the object of the present invention is not impaired in addition to the above components. Contains various known compounding agents such as additives, antistatic agents, release agents, pigments, dyes, inorganic or organic fillers, nucleating agents, fiber reinforcing agents, inorganic compounds such as carbon black, talc, clay and mica. May be. In the present invention, additives such as a commonly used halogen scavenger can also be used. As the halogen scavenger, for example, hydrotalcite is known. Moreover, heat resistance, a flame retardance, rigidity, tensile strength, bending strength, and impact strength are further improved by containing a fiber reinforcing agent.

  Furthermore, the thermoplastic resin composition according to the present invention may contain other polymers as long as the object of the present invention is not impaired. Examples of such other polymers include polyethylene, polypropylene, poly-4- Polyolefin such as methyl-1-pentene, ethylene / 1-butene copolymer, propylene / ethylene copolymer, propylene / 1-butene copolymer, modified aromatic vinyl compound / conjugated diene copolymer such as polystyrene, SEBS, CEBC, etc. Examples include polymers, polyamides other than polyamide (A), polycarbonate, polyacetal, polysulfone, polyphenylene oxide, fluororesin, silicone resin, PPS, LCP, Teflon (registered trademark), and the like. Also, modified polyethylene modified with carbonyl group, amino group, epoxy group, glycidyl group, modified polyolefin, modified aromatic vinyl compound / conjugated diene copolymer such as modified SEBS or its hydride, amino group, epoxy group, Examples thereof include modified polyolefin elastomers other than carboxylic acid-modified ethylene / α-olefin copolymer (B) modified with a glycidyl group or the like.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention is prepared by mixing and melting a polyamide resin (A) and a carboxylic acid-modified ethylene / α-olefin copolymer (B) and, if necessary, additives and / or other resins. can do. For example, it can be prepared by a method of blending and kneading additives and other resins while melting the polyamide resin (A) and the carboxylic acid-modified ethylene / α-olefin copolymer (B). At this time, a normal kneading apparatus such as an extruder or a kneader can be used.

  By kneading in this manner, a so-called polymer alloy is usually formed in which the carboxylic acid-modified ethylene / α-olefin copolymer (B) is finely dispersed in the polyamide resin (A).

  In the thermoplastic resin composition of the present invention, the polyamide resin (A) and the carboxylic acid-modified ethylene α-olefin copolymer (B) have a polyamide resin (A) content of 70 to 100% by mass, carboxylic acid-modified ethylene · The content of the α-olefin copolymer (B) is preferably in the range of 0 to 30% by mass, the content of (A) is 80 to 100% by mass, and the content of (B) is 0 to 20% by mass. % Is more preferable.

[Thermoplastic resin composition molded article]
Using the thermoplastic resin composition of the present invention, a molded body having a desired shape can be produced by utilizing a usual melt molding method, for example, a compression molding method, an injection molding method or an extrusion molding method. For example, the molded product is produced by introducing the resin composition of the present invention into an injection molding machine prepared at a cylinder temperature of about 300 to 350 ° C., bringing it into a molten state, and introducing it into a mold having a predetermined shape. can do.

  The molded body thus obtained is very excellent in low temperature impact resistance. The molded body containing the thermoplastic resin composition of the present invention has a notched IZOD impact strength at −40 ° C. of 90 J / m or more, more preferably 100 J / m or more.

  The shape of the molded product produced using the thermoplastic resin composition of the present invention is not particularly limited. For example, power tools and general industrial parts, mechanical parts such as gears and cams, printed wiring boards and electronic parts It can be used as a resin for forming electronic parts such as housings.

  The resin composition of the present invention is also suitable as a resin for forming automobile interior / exterior parts, fuel system parts, automobile electrical parts and the like. In particular, the thermoplastic resin composition of the present invention has excellent chemical resistance as a molded article for an ethanol-containing fuel system. The oil absorption after immersing the molded article of the present invention for 100 hours at 65 ° C. in an ethanol-containing fuel obtained by adding 30 vol% of ethanol to simulated gasoline (toluene / isooctane: 60/40 vol%) is 5% or less, preferably 4% or less. Yes, the flexural modulus after immersion is 1000 MPa or more, preferably 1200 MPa or more.

 EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention should not be construed as being limited to these examples.

The physical property evaluation methods performed in the examples are as follows.
(Oil absorption rate)
A test piece having a thickness of 3.2 mm, a length of 127 mm, and a width of 12.7 mm is immersed in ethanol-containing fuel at 65 ° C. for 500 hours, and the attached fuel is wiped off. The weight is measured with a balance capable of weighing in units of 0.1 mg. The difference between this weight and the weight before immersion was defined as the oil absorption, and the oil absorption relative to the weight before immersion was defined as the oil absorption.

(Bending elastic modulus after oil absorption)
The same sample whose oil absorption was measured was measured at 23 ° C. according to ASTM D-790.

(Low temperature IZOD)
A 3.2 mm thick notched IZOD test piece was measured with an IZOD impact tester in accordance with ASTM D-256 in a thermostatic chamber adjusted to −40 ° C.

(Tg)
About 5 mg of the sample was set on a differential scanning calorimeter (DSC), and once the sample was completely melted, the sample was cooled to 30 ° C., and then Tg was measured at the time of re-heating at a rate of 10 ° C./min.

(Measuring method of [η])
After 0.5 g of polyamide resin is swollen with a small amount of concentrated sulfuric acid, about 15-20 ml of concentrated sulfuric acid is added twice every 2-3 hours. After standing overnight, add concentrated sulfuric acid and make up accurately to 50 ml. The concentrated sulfuric acid solution in which this polyamide resin was dissolved was measured for the number of dripping seconds with an Ubbelohde viscometer adjusted to 25 ° C., and [η] was determined.
The following resins were used for the polyamide resin (A) and the carboxylic acid-modified ethylene / α-olefin copolymer (B) shown in Examples and Comparative Examples.
The polyamide resin shown below was adopted as the polyamide resin (A).

[Polyamide-a]
Polyamide resin comprising 55 mol% terephthalic acid and 45 mol% adicarboxylic acid in dicarboxylic acid component units, and an approximately equivalent diamine unit comprising 1,6-diaminohexane units.

[Polyamide-b]
Polyamide resin composed of 70 mol% of terephthalic acid and 30 mol% of isophthalic acid in dicarboxylic acid component units, and approximately equivalent diamine units composed of 1,6-diaminohexane units.

[Polyamide-c]
A polyamide resin in which the dicarboxylic acid component is terephthalic acid, and the diamine unit is 50 mol% of 1,6-diaminohexane and 50 mol% of 2-methyl-1,5-hexanediamine.

[Polyamide-d]
Polyamide-a and polyamide-b are polyamides equivalent in amount, consisting of 55 mol% terephthalic acid and 45 mol% adicarboxylic acid in the dicarboxylic acid component units, and approximately equivalent diamine units in 1,6-diaminohexane units. A polyamide resin composed of a composed polyamide resin and a dicarboxylic acid component of terephthalic acid, and a diamine unit of 50 mol% of 1,6-diaminohexane and 50 mol% of 2-methyl-1,5-hexanediamine.

[Polyamide-e]
Polyamide resin comprising 45% by mole of terephthalic acid and 55% by mole of adicarboxylic acid in dicarboxylic acid component units, and an approximately equivalent amount of diamine units comprising 1,6-diaminohexane units.
The following resins were employed for the carboxylic acid-modified ethylene / α-olefin copolymer (B).

[Modified PE]
Modified product (MFR = 1.5 g / 10 min; 230 ° C., malein) grafted with maleic anhydride onto ethylene / 1-butene copolymer (ethylene content = 80 mol%, crystallinity by X-ray diffraction = 5%) Acid content = 1.0 wt%). Density 0.87g / cm3, Tg = -60 ° C
Table 1 shows the resin compositions and physical properties used in Examples 1 to 6 and Comparative Examples 1 to 6.

Moreover, the following resin was used and the IZOD test was done.
Polyamide resin (A)

[Polyamide-g]
Polyamide resin composed of 90% by mole of terephthalic acid and 10% by mole of isophthalic acid in dicarboxylic acid component units, and an equivalent amount of diamine units composed of 1,6-diaminohexane units.
The following resin was adopted as the modified polyolefin.

[Modified PE-a]
A modified product obtained by grafting maleic anhydride onto an ethylene / 1-butene copolymer (maleic acid content = 1.0% by weight). Density 0.87g / cm3, Tg = -60 ° C

[Modified PE-b]
A modified product obtained by grafting maleic anhydride onto an ethylene / 1-butene copolymer (maleic acid content = 1.0% by weight). Density 0.92g / cm3, Tg = -24 ° C

[Modified PP]
Carboxylic acid-modified polypropylene (maleic acid content = 1.1% by weight). Tg = + 5 ° C
Table 2 shows the resin compositions and physical properties used in the examples.

Claims (8)

It consists of 50 to 99 mol% of terephthalic acid component units, 1 to 50 mol% of aromatic dicarboxylic acid component units other than terephthalic acid, and / or 1 to 50 mol% of aliphatic dicarboxylic acid component units having 4 to 18 carbon atoms. A dicarboxylic acid component unit;
A polyamide resin composed of a repeating unit consisting of an aliphatic diamine component unit and / or a diamine component unit consisting of an alicyclic diamine component unit,
A polyamide resin (A) having an intrinsic viscosity measured in concentrated sulfuric acid at 25 ° C. in the range of 1.0 to 3.0 dl / g, a melting point of 300 to 340 ° C., and a glass transition temperature of 80 ° C. or higher;
And a resin composition comprising a carboxylic acid-modified product (B) of an ethylene / α-olefin polymer having an ethylene content of 70 to 95 mol% and a glass transition temperature of −20 ° C. or less, A thermoplastic resin characterized in that the content of the polyamide resin (A) is in the range of 70 to 100% by mass and the content of the carboxylic acid-modified ethylene / α-olefin copolymer (B) is in the range of 0 to 30% by mass. Composition. The thermoplastic resin composition according to claim 1, wherein the polyamide resin (A) is 80 to 100% by mass and the carboxylic acid-modified ethylene / α-olefin copolymer (B) is 0 to 20% by mass. The thermoplastic resin composition according to claim 1 or 2, wherein the aromatic ratio in the polyamide resin (A) is 25 mol% or more and 50% or less. The thermoplastic resin composition of Claims 1-3 whose glass transition temperature of a polyamide resin (A) is 100 degreeC or more. The thermoplastic resin composition of Claims 1-4 whose glass transition temperature of a polyamide resin (A) is 120 degreeC or more. The thermoplastic resin composition according to any one of claims 1 to 5, wherein the carboxylic acid component unit in the carboxylic acid-modified product (B) of the ethylene / α-olefin copolymer is 0.01 to 10% by mass. . The thermoplastic resin composition according to any one of claims 1 to 6, wherein the glass transition temperature of the carboxylic acid-modified product (B) of the ethylene / α-olefin copolymer is -40 ° C or lower. A molded article for an ethanol-containing fuel system comprising the thermoplastic resin composition according to any one of claims 1 to 7.