JP6831252B2 - Transparent polyamide resin composition - Google Patents

Description

The present invention relates to a composition containing a transparent polyamide and a modified ethylene polymer.

Transparent polyamide has excellent transparency while maintaining the excellent properties of polyamide (for example, strength, rigidity, and abrasion resistance), so it is used in applications where transparency is required (for example, eyeglass frames, wristwatch band members, etc.). Is under study (see, for example, Patent Document 1).
Depending on the application for which this transparent polyamide is being studied, it is required to improve the impact resistance. Generally, in order to improve the impact resistance, a method of adding a polymer having excellent impact resistance is known.

Japanese Patent Application Laid-Open No. 06-065371

However, when a polymer is added to the transparent polyamide and used, there is a problem that the transparency, which is one of the characteristics of the transparent polyamide, is significantly lowered. An object of the present invention is to provide a transparent polyamide resin composition having improved mechanical properties such as impact strength without impairing the transparency of the transparent polyamide.

The transparent polyamide resin composition of the present invention is transparent and contains 99 to 60% by weight of the transparent polyamide (A) and 1 to 40% by weight of the modified ethylene polymer (B) graft-modified with an unsaturated carboxylic acid or a derivative thereof. Polyamide resin composition
The amount of the modified ethylene-based polymer (B) grafted with the unsaturated carboxylic acid or its derivative on the ethylene-based polymer (B') before modification is in the range of 0.1 to 10% by weight.
The ethylene-based polymer (B') before modification contains high-pressure radical method low-density polyethylene (B'1) and an ethylene / α-olefin copolymer (B') containing ethylene units and α-olefin units having 3 or more carbon atoms. It is characterized by containing at least one polymer selected from the group consisting of 2) and having a density of the ethylene-based polymer (B') of 890 to 925 kg / m ³ .

The ethylene-based polymer (B') before modification is preferably at least one selected from the high-pressure radical method low-density polyethylene, the ethylene / 1-butene copolymer, and the ethylene / 1-hexene copolymer. The MFR (190 ° C., 2.16 kg overload) of the modified ethylene polymer (B) is preferably 0.1 to 100 g / 10 minutes.

According to the present invention, a transparent polyamide resin composition having improved mechanical properties such as impact strength can be produced without impairing the transparency of the transparent polyamide.

The transparent polyamide resin composition of the present invention contains a transparent polyamide (A). The transparent polyamide is a polyamide having excellent light transmittance, and is a polyamide having a total light transmittance of 85% or more, preferably 90% or more.

Examples of the transparent polyamide (A) include amorphous or microcrystalline polyamide obtained by condensing diamine and a dicarboxylic acid.
Examples of the diamine include 1,6-hexamethylenediamine, 2-methyl-1,5-diaminopentane, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1, Linear or branched aliphatic diamines having 6 to 14 carbon atoms such as 9-nonamethylenediamine, 1,10-decamethylenediamine, and 1,12-decamethylenediamine;
4,4'-Diaminodicyclohexylmethane (also known as bis- (4-amino-cyclohexyl) -methane), 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylpropane, 1 , 4-Diaminocyclohexane, 1,4-bis (aminomethyl) -cyclohexane, 2,6-bis (aminomethyl) -norbornan, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, bis- (4-) Alicyclic diamines having 6 to 22 carbon atoms such as amino-3-methyl-cyclohexyl) methane (also known as 4,4'-diamino-3,3'-dimethyldicyclohexylmethane) and isophoronediamine;
Examples thereof include aromatic diamines having 8 to 22 carbon atoms such as m-xylylenediamine, p-xylylenediamine, and bis (4-aminophenyl) propane. These diamines may be used alone or in combination of two or more.

Examples of the dicarboxylic acid include adipic acid, 2,2,4-trimethyladipic acid, 2,4,4-trimethyladipic acid, azelaic acid, sebacic acid, 1,12-dodecanedic acid and the like having 6 to 6 carbon atoms. 22 linear or branched aliphatic dicarboxylic acids;
Cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxydicyclohexylmethane, 3,3'-dimethyl-4,4'-dicarboxydicyclohexylmethane, 4,4'-dicarboxydicyclohexylpropane, 1,4- An alicyclic dicarboxylic acid having 6 to 22 carbon atoms such as bis (carboxymethyl) cyclohexane;
4,4'-Diphenylmethanedicarboxylic acid, isophthalic acid, tributylisophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalindicarboxylic acid, 2,6-naphthalindicarboxylic acid, 2,7-naphthalindicarboxylic acid , Diphenyl acid, diphenyl ether-4,4'-dicarboxylic acid and other aromatic dicarboxylic acids having 8 to 22 carbon atoms. These dicarboxylic acids may be used alone or in combination of two or more.

The transparent polyamide (A) can also be obtained by ring-opening polymerization of lactam, condensation of ω-aminocarboxylic acid, or the like.
Examples of the lactam include ε-caprolactam and ω-laurin lactam. These lactams may be used alone or in combination of two or more.

Examples of the ω-aminocarboxylic acid include ω-aminoenanthic acid and ω-aminononanoic acid. These ω-aminocarboxylic acids may be used alone or in combination of two or more.

Specific examples of the transparent polyamide (A) include poly- ω-aminoheptanoic acid (PA7) , polyundecaneamide (PA11), polylaurinlactam (PA12) , polyhexamethyleneisophthalamide (PA6I), and polymethoxylyleniso. Phtalamide (PAMXDI), a homopolymer obtained by condensation of bis- (4-amino-3-methyl-cyclohexyl) methane (MACM) and 1,10-decandicarboxylic acid (PAMACM10), MACM and sebacic acid. Polyamide obtained by condensation (PAMACM12), bis- (4-amino-cyclohexyl) -methane) (also known as 4,4'-diaminodicyclohexylmethane) and 1,10-decandicarboxylic acid alone. Polyamide homopolymer such as polymer (PACM12);
PA 6I / 6T, PAMXDI / 6I, PAMXDI / MXDT / 6I / 6T, PAMXDI / 12I, PAMACM12, PAMACMI / 12, PAMACMI / MACMT / 12, PA6I / MACMI / 12, PA6I / 6T / MACMI / MACMT, PA6I / 6T / MACMI / MACMT / 12, PAMACM6 / 11, PAMACMI / MACM12, PACMT / PACM10 / 610 (ACM stands for bis- (4-amino-cyclohexyl) -methane) (4,4'-diaminodicyclohexylmethane), PACMT / PACM10 / 614, PACMT / PACM14 / 614, PACMT / 618, PACMT / 12, PACMT / MACM14 / 12, PACMT / MACM14 / 614, PACMT / IPD14 / 614 (IPD stands for isophorone diamine), carbon number 4-12 A copolymer having a polyamide unit composed of a condensate of an aliphatic alkylenediamine and 2,6-naphthalenedicarboxylic acid and a polyamide unit composed of a condensate of an aliphatic alkylenediamine having 4 to 12 carbon atoms and isophthalic acid. Polyamide copolymers can be mentioned.

Among these transparent polyamides (A) , PA 610, PA 612, PA 11, PA 12 in terms of low water absorption, dimensional stability, electrical characteristics, chemical resistance, oil resistance, weather resistance, yellowing resistance, flexibility, etc. , And PACM12 are preferred.

A commercially available product can also be used as the transparent polyamide (A). Commercially available products include Trogamid CX7323, Trogamid T, Trogamid CX9701 (trade name, above, Daicel Degussa), Grillamide TR-90, Grillamide TR-155, Griboly G21, Grillamide TR-55 LX ( above, Ems-Chemie). -Japan), Cristamide MS1100, Cristamide MS1700 (above, Arkema ) and the like .

The transparent polyamide resin composition of the present invention contains a modified ethylene-based polymer (B) in which the ethylene-based polymer (B') is graft-modified with an unsaturated carboxylic acid or a derivative thereof.
The ethylene-based polymer (B') used as a raw material for graft modification includes both high-pressure radical low-density polyethylene (B'1) and ethylene / α-olefins containing ethylene units and α-olefin units having 3 or more carbon atoms. It contains at least one polymer selected from the group consisting of the polymer (B'2), and its density is 890 to 925 kg / m ³ .

The high-pressure radical method low-density polyethylene (B'1) is a polyethylene having many branches having long-chain branches obtained by polymerizing ethylene by a so-called high-pressure radical polymerization method.
The α-olefin as an α-olefin unit contained in the ethylene / α-olefin copolymer (B'2) is an α-olefin having 3 or more carbon atoms, but preferably an α-olefin having 3 to 18 carbon atoms. Is. Examples of the α-olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and the like. Among these α-olefins, 1-butene and 1-hexene are preferable. These α-olefins may be used alone or in combination of two or more.

The ethylene unit content of the ethylene / α-olefin copolymer (B'2) is preferably 89 to 99 mol%, more preferably 90 to 98 mol%, and the α-olefin content having 3 or more carbon atoms is preferable. Is 11 to 1 mol%, more preferably 10 to 2 mol%.

When the α-olefin content and the ethylene content are in the above ranges, the dispersibility of the modified ethylene / α-olefin copolymer after graft modification in the transparent polyamide tends to be excellent.

The ethylene / α-olefin copolymer (B'2) is, for example, in the presence of a vanadium-based catalyst composed of a soluble vanadium compound and an alkylaluminum halide compound, and a zirconium-based catalyst composed of a zirconium metallocene compound and an organic aluminum oxy compound. In addition, it can be prepared by randomly copolymerizing ethylene and α-olefin.

Among the above ethylene-based polymers (B'), high-pressure radical method low-density polyethylene, ethylene / 1-butene copolymer, and ethylene / 1-hexene copolymer are preferable.
The density of the ethylene polymer (B') is 890 to 925 kg / m ³ , preferably 890 to 920 kg / m ³ . When the density of the ethylene-based polymer (B') is within the above range, the modified ethylene / α-olefin copolymer after graft modification has excellent dispersibility in transparent polyamide, and the resulting resin composition becomes transparent. It tends to be excellent.

From the viewpoint of handleability at the time of preparing the resin composition, the MFR (190 ° C., 2.16 kg overload) of the ethylene polymer (B') before modification is preferably 0.5 to 100 g / 10 minutes, more preferably. Is 1 to 90 g / 10 minutes, more preferably 1 to 90 g / 10 minutes.

The modified ethylene-based polymer (B) is obtained by graft-modifying an unsaturated carboxylic acid or a derivative thereof with an unmodified ethylene-based polymer (B').
Unsaturated carboxylic acids include, for example, unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid; maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, and nadic acid (registered trademark). ) (Endosys-bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid) and other unsaturated dicarboxylic acids.

Examples of the derivative of the unsaturated carboxylic acid include acid halide compounds, amide compounds, imide compounds, acid anhydrides and ester compounds of the unsaturated carboxylic acid. Specific examples of the unsaturated carboxylic acid derivative include malenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maleate.

Among these unsaturated carboxylic acids or derivatives thereof, unsaturated dicarboxylic acids or acid anhydrides thereof are preferable, maleic acid, nadic acid (registered trademark) or their acid anhydrides are more preferable, and maleic acid or maleic acid anhydrides are more preferable. Is even more preferable.

The graft modification of the unmodified ethylene polymer (B') can be carried out by various conventionally known methods, for example, the following methods.
(1) A method in which an unmodified ethylene-based polymer (B') is melted and unsaturated carboxylic acid or the like is added to perform graft modification (graft copolymerization).
(2) A method in which an unmodified ethylene polymer (B') is dissolved in a solvent and an unsaturated carboxylic acid or the like is added to carry out graft modification (graft copolymerization).

At the time of graft modification, in order to efficiently perform graft modification (graft copolymerization) of unsaturated carboxylic acid or the like, it is preferable to perform graft modification in the presence of a radical polymerization initiator.

Examples of the radical polymerization initiator include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxide benzoate) -3-hexine, 1 , 4-Bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butylperacetate, 2,5-dimethyl-2,5-di- (tert-butyl peroxide) -3-hexine, 2,5-dimethyl −2,5-di (tert-butyl peroxide) hexane, tert-butylperbenzoate, tert-butylperphenylacetate, tert-butylperisobutyrate, tert-butylper-sec-octate, tert-butylperpivalate, Organic peroxides such as cumylperpivalate, tert-butylperdiethyl acetate;
Examples thereof include azo compounds such as azobisisobutyronitrile and dimethylazoisobutyrate.

Among these radical polymerization initiators, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) -3-hexine, 2,5-dimethyl-2,5 Dialkyl peroxides such as −di (tert-butylperoxy) hexane and 1,4-bis (tert-butylperoxyisopropyl) benzene are preferred.

The radical polymerization initiator is usually 0.001 to 1 part by weight, preferably 0.005 to 0.5 part by weight, more preferably 0. parts by weight, based on 100 parts by weight of the unmodified ethylene polymer (B'). It is used in an amount of 01 to 0.3 parts by weight.

The reaction temperature for graft modification is usually in the range of 60 to 350 ° C, preferably 150 to 300 ° C.
The amount of graft of the unsaturated carboxylic acid or its derivative in the modified ethylene polymer (B) is 0.1 to 10% by weight, preferably 0.1 to 10% by weight, based on 100% by weight of the unmodified ethylene polymer (B'). It is 0.1 to 5% by weight, more preferably 0.2 to 3% by weight.

The modified ethylene polymer (B) having a graft amount in the above range not only has excellent dispersibility with respect to the transparent polyamide, but also does not impair the transparency of the transparent polyamide. Further, when such a modified ethylene polymer (B) is used, a transparent polyamide resin composition having excellent mechanical properties such as impact strength can be obtained.

From the viewpoint of excellent dispersibility in the transparent polyamide (A), the MFR (190 ° C., 2.16 kg overload) of the modified ethylene polymer (B) is preferably 0.1 to 100 g / 10 minutes, more preferably. It is 0.3 to 90 g / 10 minutes, more preferably 0.4 to 80 g / 10 minutes.

From the viewpoint of excellent dispersibility in the density transparent polyamide modified ethylene polymer (B) (A), preferably 890~925kg / m ^3, more preferably 895~920kg / m ^3.

The transparent polyamide resin composition of the present invention contains 99 to 60% by weight of the transparent polyamide (A), 1 to 40% by weight of the modified ethylene polymer (B), 95 to 70% by weight of the transparent polyamide (A), and It preferably contains 5 to 30% by weight of the modified ethylene polymer (B), more preferably 90 to 80% by weight of the transparent polyamide (A), and 10 to 20% by weight of the modified ethylene polymer (B). .. By containing the transparent polyamide (A) and the modified ethylene polymer (B) in such an amount ratio, a transparent polyamide resin having excellent mechanical properties such as impact strength without impairing the original transparency of the transparent polyamide. The composition is obtained.

In addition to the transparent polyamide (A) and the modified ethylene-based polymer (B), the transparent polyamide resin composition of the present invention contains an antioxidant, an ultraviolet absorber, and a photoprotectant as long as the effects of the present invention are not impaired. Includes additives such as phosphite-based heat stabilizers, peroxide decomposing agents, basic auxiliary stabilizers, nucleating agents, plasticizers, lubricants, antistatic agents, flame retardants, pigments, dyes, fillers, etc. You may be. Further, the transparent polyamide resin composition of the present invention may contain a polymer other than the transparent polyamide (A) and the modified ethylene polymer (B) as long as the effects of the present invention are not impaired.

The transparent polyamide resin composition of the present invention is prepared by melt-mixing a transparent polyamide (A), a modified ethylene polymer (B), and an additive to be blended as necessary by various conventionally known methods. Will be done. For example, the transparent polyamide resin composition is a mixture obtained after the above components are simultaneously or sequentially put into a mixer such as a Henschel mixer, a V-type blender, a tumbler mixer, or a ribbon blender and mixed. Is obtained by melt-kneading with a melt-kneading device such as a single-screw extruder, a multi-screw extruder, a kneader, or a Banbury mixer.

Among these melt-kneading devices, if a device having excellent kneading performance such as a multi-screw extruder, a kneader, or a bumperry mixer is used, a high-quality transparent polyamide resin composition in which each component is more uniformly dispersed can be obtained. Be done. In addition, the above additives, such as antioxidants, may be added as needed at any stage of mixing and melt kneading.

The transparent polyamide resin composition of the present invention obtained as described above is a desired molded product having various shapes by various conventionally known melt molding methods such as injection molding, extrusion molding, compression molding, foam molding and the like. Can be.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. The raw material components used in Examples and Comparative Examples are as follows.

Transparent polyamide (A)
"Microcrystalline transparent polyamide": manufactured by Daicel Evonik, Trogamid (registered trademark) CX7323, thermal deformation temperature (load 1.8 MPa) 105 ° C., density; 1024 kg / m ³
Ethylene polymer before graft modification (B')
Four types of ethylene / 1-butene copolymer (EBR) manufactured by Mitsui Chemicals Co., Ltd. (B'-1) to (B'-4) and ethylene / 1-hexene copolymer manufactured by Prime Polymer Co., Ltd. Two types of coalesced (EHR) (B'-5) to (B'-6) and low density polyethylene (B'-7) manufactured by Mitsui DuPont Polychemical Co., Ltd. were used. Only the maleic anhydride modified product (B'-3) was used in the comparative example, and the other maleic anhydride modified products were used in the examples. The properties of (B'-1) to (B'-7) were as follows.
Ethylene 1-butene copolymer (B'-1) ethylene content 92 mol%, MFR 18 g / 10 minutes measured at 190 ° C., 2.16 kg load, density 893 kg / m ³
Ethylene 1-butene copolymer (B'-2) ethylene content 92 mol%, MFR 3.6 g / 10 minutes measured at 190 ° C., 2.16 kg load, density 893 kg / m ³
Ethylene 1-butene copolymer (B'-3) ethylene content 88 mol%, MFR 18 g / 10 minutes measured at 190 ° C., 2.16 kg load, density 885 kg / m ³
Ethylene 1-butene copolymer (B'-4) ethylene content 95 mol%, MFR 1.2 g / 10 minutes measured at 190 ° C., 2.16 kg load, density 904 kg / m ³
Ethylene 1-hexene copolymer (B'-5) ethylene content 96 mol%, MFR 10 g / 10 minutes measured at 190 ° C., 2.16 kg load, density 910 kg / m ³
Ethylene 1-hexene copolymer (B'-6) ethylene content 97 mol%, MFR 10 g / 10 minutes measured at 190 ° C., 2.16 kg load, density 920 kg / m ³
-Low density polyethylene (B'-7) measured at 190 ° C. with a load of 2.16 kg, MFR 10 g / 10 minutes, density 920 kg / m ³
The methods for measuring various physical properties of the maleic anhydride-modified ethylene-based polymer (B) are as follows.

(Preparation of press sheet for measurement)
A pressure sheet was formed at 7.5 MPa using a hydraulic heat press machine manufactured by Shinto Metal Industry Co., Ltd. set at 180 ° C. For a sheet with a thickness of 0.5 to 3 mm, apply residual heat with no load for 5 minutes, pressurize at 7.5 MPa for 2 minutes, and then use another hydraulic heat press machine manufactured by Shinto Metal Industry Co., Ltd. set at 20 ° C. , 7.5 MPa and cooled for 5 minutes to prepare a sample for measurement. A brass plate having a thickness of 5 mm was used as the hot plate. The samples prepared by the above method were used for various physical property evaluation samples.

(MFR)
The melt flow rate (MFR) was measured under the conditions of 190 ° C. and 2.16 kg load according to ASTM D2240.

(density)
In accordance with ASTM D1505, the density was measured by the density gradient tube method using the strand resin that flows out in the MFR measurement.

[Preparation of maleic anhydride-modified ethylene polymer (B)]
Maleic anhydride-modified ethylene-based polymers (B-1) to (B-3) and (B-5) to (B-8) used in Examples, and maleic anhydride-modified polyolefins (B) used in Comparative Examples. The preparation method of -4) is shown below.

[Synthesis Example 1] (Method for preparing B-1)
10 kg of a resin composition (C1) composed of 100% by mass of an ethylene / 1-butene copolymer (B'-1), 90 g of maleic anhydride (MAH), and 2,5-dimethyl-2,5-di- (t). A solution prepared by dissolving 4.5 g of −butylperoxy) -3-hexine (trade name: perhexine 25B) in acetone was blended. Next, the obtained blend was charged from the hopper of a shaft extruder having a screw diameter of 30 mm and L / D = 42, and extruded into a strand shape at a resin temperature of 250 ° C., a screw rotation speed of 180 rpm, and a discharge rate of 10 kg / hr. The obtained strand was sufficiently cooled and then granulated to obtain a maleic anhydride-modified ethylene-based polymer (B-1). The results of measuring the physical properties of the obtained (B-1) are shown in Table 1. The degree of modification (maleic anhydride graft amount) of the maleic anhydride-modified ethylene polymer (B) is a calibration curve prepared separately based on the wave number 1780 cm ^-1 peak intensity assigned to the carbonyl group by FT-IR. I asked for it.

[Synthesis Example 2] (Method for preparing B-2)
A maleic anhydride-modified ethylene-based polymer (B-2) was obtained in the same manner as in Synthesis Example 1 except that the MAH compounding amount was 120 g and the perhexine 25B compounding amount was 6 g in the preparation method of (B-1). It was. Table 1 shows the results of measuring the physical characteristics of the obtained (B-2).

[Synthesis Example 3] (Method for preparing B-3)
Synthesis example except that the ethylene / 1-butene copolymer (B'-2) was used instead of the ethylene / 1-butene copolymer (B'-1) in the preparation method of (B-1). In the same manner as in No. 1, a maleic anhydride-modified ethylene-based polymer (B-3) was obtained. Table 1 shows the results of measuring the physical properties of the obtained (B-3).

[Synthesis Example 4] (Method for preparing B-4)
Synthesis example except that the ethylene / 1-butene copolymer (B'-3) was used instead of the ethylene / 1-butene copolymer (B'-1) in the preparation method of (B-1). In the same manner as in No. 1, a maleic anhydride-modified ethylene-based polymer (B-4) was obtained. Table 1 shows the results of measuring the physical characteristics of the obtained (B-4).

[Synthesis Example 5] (Method for preparing B-5)
Synthesis example except that ethylene 1-butene copolymer (B'-4) was used instead of ethylene 1-butene copolymer (B'-1) in the preparation method of (B-1). In the same manner as in No. 1, a maleic anhydride-modified ethylene-based polymer (B-5) was obtained. The results of measuring the physical properties of the obtained (B-5) are shown in Table 1.

[Synthesis Example 6] (Method for preparing B-6)
Synthesis example except that in the preparation method of (B-1), an ethylene / 1-hexene copolymer (B'-5) was used instead of the ethylene / 1-butene copolymer (B'-1). In the same manner as in No. 1, a maleic anhydride-modified ethylene-based polymer (B-6) was obtained. The results of measuring the physical properties of the obtained (B-6) are shown in Table 1.

[Synthesis Example 7] (Method for preparing B-7)
Synthesis example except that in the preparation method of (B-1), an ethylene / 1-hexene copolymer (B'-6) was used instead of the ethylene / 1-butene copolymer (B'-1). In the same manner as in No. 1, a maleic anhydride-modified ethylene-based polymer (B-7) was obtained. The results of measuring the physical properties of the obtained (B-7) are shown in Table 1.

[Synthesis Example 8] (Method for preparing B-8)
In the preparation method of (B-1), the same procedure as in Synthesis Example 1 was carried out except that low-density polyethylene (B'-7) was used instead of the ethylene / 1-butene copolymer (B'-1). , Maleic anhydride-modified ethylene-based polymer (B-8) was obtained. The results of measuring the physical properties of the obtained (B-8) are shown in Table 1.

[Example 1]
A dry blend was prepared by mixing 90 parts by mass of a microcrystalline transparent polyamide [manufactured by Daicel Evonik, trade name: Trogamide CX7323] and 10 parts by mass of a maleic anhydride-modified polyolefin (B-1) using a Henschel mixer. .. Next, this dry blend was supplied to a twin-screw extruder (L / D = 42, 30 mmφ) set at 270 ° C. to prepare pellets of the polyamide resin composition. The pellets of the obtained polyamide resin composition were dried at 80 ° C. for 12 hours, and then injection molded under the following conditions to prepare a test piece for a physical characteristic test.

(Injection molding conditions)
Cylinder temperature: 270 ° C
Injection pressure: 400 kg / cm ²
Mold temperature: 80 ° C
Subsequently, the physical characteristics of the polyamide resin composition were evaluated by the following method.

(2) Bending test The flexural modulus and bending strength were measured according to ASTM D790 using a test piece having a thickness of 1/8. The state of the test piece was prepared in a dry state at a temperature of 23 ° C. for 2 days. It was.

(3) Izod Impact Test Using a test piece with a thickness of 1/8, the impact strength of the notched Izod was measured at 23 ° C and -30 ° C according to ASTM D256. The state of the test piece was adjusted to 23 in a dry state. It was carried out at a temperature of ° C. for 2 days.

(4) Optical property test (internal haze, total light transmittance)
Internal haze and total light transmittance were measured according to ASTM D1003 using a square plate test piece having a thickness of 2 mm. The state of the test piece was prepared in a dry state at a temperature of 23 ° C. for 2 days.

[Example 2]
A polyamide resin composition was prepared in the same manner as in Example 1 except that maleic anhydride-modified polyolefin (B-2) was used instead of maleic anhydride-modified styrene-based block copolymer (B-1). The results are shown in Table 2.

[Example 3]
A polyamide resin composition was prepared in the same manner as in Example 2 except that the amount of the transparent polyamide was changed to 80 parts by weight and the amount of the maleic anhydride-modified polyolefin (B-2) was changed to 20 parts by weight. The results are shown in Table 2.

[Example 4]
A polyamide resin composition was prepared in the same manner as in Example 1 except that maleic anhydride-modified polyolefin (B-3) was used instead of maleic anhydride-modified styrene-based block copolymer (B-1). The results are shown in Table 2.

[Example 5]
A polyamide resin composition was prepared in the same manner as in Example 1 except that maleic anhydride-modified polyolefin (B-5) was used instead of maleic anhydride-modified styrene-based block copolymer (B-1). The results are shown in Table 2.

[Example 6]
A polyamide resin composition was prepared in the same manner as in Example 5 except that the amount of the transparent polyamide was changed to 80 parts by mass and the amount of the maleic anhydride-modified polyolefin (B-5) was changed to 20 parts by mass. The results are shown in Table 2.

[Example 7]
A polyamide resin composition was prepared in the same manner as in Example 1 except that maleic anhydride-modified polyolefin (B-6) was used instead of maleic anhydride-modified styrene-based block copolymer (B-1). The results are shown in Table 2.

[Example 8]
A polyamide resin composition was prepared in the same manner as in Example 7 except that the amount of the transparent polyamide was changed to 80 parts by mass and the amount of the maleic anhydride-modified polyolefin (B-6) was changed to 20 parts by mass. The results are shown in Table 2.

[Example 9]
A polyamide resin composition was prepared in the same manner as in Example 1 except that maleic anhydride-modified polyolefin (B-7) was used instead of maleic anhydride-modified styrene-based block copolymer (B-1). The results are shown in Table 2.

[Example 10]
A polyamide resin composition was prepared in the same manner as in Example 1 except that maleic anhydride-modified polyolefin (B-8) was used instead of maleic anhydride-modified styrene-based block copolymer (B-1). The results are shown in Table 2.

[Comparative Example 1]
A polyamide resin composition was prepared in the same manner as in Example 1 except that maleic anhydride-modified polyolefin (B-4) was used instead of maleic anhydride-modified styrene-based block copolymer (B-1). These results are shown in Table 2.

[Reference example 1]
After the pellet of the transparent polyamide itself was dried at 80 ° C. for 12 hours, injection molding was performed under the above-mentioned conditions to prepare a test piece for a physical characteristic test. Then, the physical properties of the transparent polyamide were evaluated in the same manner. The results are shown in Table 2.

Claims (2)

A transparent polyamide resin composition containing 99 to 60% by weight of the transparent polyamide (A) and 1 to 40% by weight of the modified ethylene polymer (B) graft-modified with an unsaturated carboxylic acid or a derivative thereof.
The amount of the modified ethylene-based polymer (B) grafted with the unsaturated carboxylic acid or its derivative on the ethylene-based polymer (B') before modification is in the range of 0.1 to 10% by weight.
The ethylene-based polymer (B') before modification is a high-pressure radical method low-density polyethylene (B'1), and the density of the ethylene-based polymer (B') is 890 to 925 kg / m ^3, which is transparent. Polyamide resin composition. The transparent polyamide resin composition according to claim 1 , wherein the MFR (190 ° C., 2.16 kg overload) of the modified ethylene polymer (B) is 0.1 to 100 g / 10 minutes.