JPH05287134A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having high surface hardness, excellent heat resistance, low discoloration and improved appearance by blending a polyamide with an olefinic elastomer and a specific modified olefinic elastomer in a specific ratio. CONSTITUTION:(A) A polyamide (preferably nylon 6 or nylon 66) is blended with (B) an olefinic elastomer (e.g. ethylene-propylene-diene copolymer rubber) and (C) an olefinic elastomer modified with an unsaturated glycidyl compound of formula I (R is H or 1-6C alkyl; Ar is glycidyloxy-containing 6-20 aromatic hydrocarbon; (n) is 1-4) in a weight ratio of the component A/component B+C of 70/30-2/98 and the component B/component C of 5/95-95/5 to give the objective composition. A compound of formula II is preferable as the unsaturated glycidyl compound. The composition is obtained preferably by blending the components A to C in a molten state at 210-290 deg.C.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition comprising a polyamide and an olefin elastomer. More specifically, it has excellent impact resistance and elasticity, high surface hardness, heat resistance and good appearance, and can be suitably used for various sealing materials, tubes, industrial parts, office supplies, sports equipment, toys and the like. The present invention relates to a thermoplastic resin composition including a polyamide and an olefin elastomer.

[0002]

2. Description of the Related Art Polyolefin elastomers are lightweight and excellent in water resistance, weather resistance and moldability, but their hardness is low, so that the surface is easily scratched and heat resistance is poor.

Therefore, an improved method of mixing a filler of an appropriate inorganic material or a crystalline resin such as polyethylene or polypropylene has been attempted. However, when a filler is added, the performance of the elastomer such as impact resistance and elasticity is impaired, and even when a crystalline resin is added, the heat resistance is not sufficiently improved, and neither is a practical method.

In recent years, research has been actively conducted to obtain a resin composition having both properties by melt-mixing (alloying) two or more polymers having different properties. Polyamide is a resin having excellent mechanical strength, which is a drawback of the olefin-based elastomer, and heat resistance. Therefore, by blending the polyamide with the olefin-based elastomer, it is possible to obtain a polyolefin-based resin having excellent water resistance and weather resistance. It is expected to be an elastomer composition having the properties of the elastomer and the polyamide excellent in mechanical strength, heat resistance and the like.

However, since the polyamide and the olefin elastomer have poor compatibility with each other, the thermoplastic resin composition in which both are mixed has a lowered surface hardness, impact resistance, elasticity, etc.
A composition having the intended physical properties cannot be obtained.

[0006] Therefore, the present applicant previously mixed and melt-kneaded an unsaturated carboxylic acid anhydride or an epoxy-modified olefinic elastomer with a polyamide for the purpose of improving the compatibility between the polyamide and the olefinic elastomer. By improving the compatibility dispersibility of the polyamide and the olefin-based elastomer, a thermoplastic resin composition in which the surface hardness is improved and the impact resistance and elasticity are prevented from decreasing (Japanese Patent Application No. 2-139280) has been proposed. issue). According to the above thermoplastic resin composition, improvement in surface hardness, reduction in impact resistance and elongation, etc. are prevented, but coloring (yellowing) is observed in the obtained composition, which causes a problem in appearance as a product. was there.

Therefore, an object of the present invention is to provide a thermoplastic resin composition comprising polyamide and an olefin-based elastomer, which has good impact resistance and elasticity, high surface hardness and good heat resistance and appearance. It is in.

[0008]

Means for Solving the Problems As a result of intensive studies by the present inventors, when a polyamide, an olefin-based elastomer and an olefin-based elastomer modified with an unsaturated glycidyl compound were blended in a specific ratio, the surface hardness was high. ,
The present invention has been accomplished by finding that a thermoplastic resin composition having excellent heat resistance, little coloration, and good appearance can be obtained.

That is, the present invention comprises (a) a polyamide, (b) an olefin elastomer, and (c) the following general formula (I):

[Wherein, R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms having at least one glycidyloxy group, and n Represents an integer of 1 to 4. ] The olefinic elastomer modified with the unsaturated glycidyl compound shown by these is contained, and the ratio of a component (a) and a component (b) + (c) is (a) / ((b) + (c) by weight ratio. ) = 70 / 30-2
/ 98, and the ratio of the component (b) to the component (c) is (b) / (c) = 5/95 to 95/5 in weight ratio, and a thermoplastic resin composition is provided. It is a thing.

The thermoplastic resin composition of the present invention will be described in detail below. The polyamide, which is the component (a) of the thermoplastic resin composition used in the present invention, is a polymer compound having an acid amide (-CONH-) bond as a repeating unit, and depending on the polymerization mode, (1) lactam ring opening By polymerization, (2)
Examples thereof include polycondensation of aminocarboxylic acid and (3) polycondensation of diamine and dibasic acid.

For example, hexamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4
-Or a fat such as 2,4,4-trimethylhexamethylenediamine, 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane), m- or p-xylylenediamine Group, alicyclic or aromatic diamine, adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid,
Polyamides produced from aliphatic, alicyclic or aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, from aminocarboxylic acids such as 6-aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid Crystalline or amorphous polyamide produced, ε
-Caprolactam, polyamides produced from lactams such as ω-dodecalactam, and copolyamides composed of these components, or mixtures of these polyamides.

Specific examples of the polyamide include nylon 6, nylon 66, nylon 610 and nylon 61.
2, nylon 11, nylon 12, aromatic nylon, amorphous nylon and the like. Of these, nylon 6 and nylon 66, which have particularly good rigidity and heat resistance,
Is preferred. In the present invention, the molecular weight of the polyamide is not particularly limited, but polyamides having a relative viscosity η _r measured in 98% sulfuric acid based on JIS K6810 of 0.5 or more, of which 2.0 or more are preferable because they have excellent mechanical strength.

The (b) olefin-based elastomer of the thermoplastic resin composition in the present invention is ethylene and one kind of α-olefin other than ethylene such as propylene, 1-butene, 1-hexene and 4-methyl-pentene. It also means a copolymer rubber with two or more kinds. The copolymer rubber of ethylene and one or more kinds of α-olefins other than ethylene is typically ethylene-butene copolymer rubber (EBR), ethylene-propylene copolymer rubber (EPR). And ethylene-propylene-diene copolymer rubber (EPDM). Ethylene
As the diene in the propylene-diene copolymer rubber (EPDM), it is possible to use a non-conjugated diene such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylenenorbornene or a conjugated diene such as butadiene or isoprene. it can.

The ethylene content in the olefin elastomer is 5 to 95% by weight, preferably 10 to
90% by weight. An ethylene content of less than 5% by weight,
Alternatively, if it exceeds 95% by weight, it becomes difficult to exhibit properties as an elastomer. The crystallinity of such an olefin elastomer is usually 40% by weight or less.

The ethylene-propylene copolymer rubber (EPR) used in the present invention has a content of repeating units derived from ethylene of 50 to 80 mol% and a content of repeating units of propylene derived from 20 to 20 mol%. It is preferably 50% by weight. A more preferable range is 30 to 40 mol% of ethylene-based repeating units and 30 to 40 mol% of propylene-based repeating units.

The EPR melt flow rate (MF
R, 230 ° C., 2.16 kg load) is preferably in the range of 0.01 to 50 g / 10 minutes, more preferably 0.5 to 3
It is 0 g / 10 minutes.

The ethylene-butene copolymer rubber (EBR) used in the present invention has a content of repeating units derived from ethylene of 50 to 90 mol% and a content of repeating units derived from butene of 10 to 10. It is preferably 50% by weight. A more preferable range is 60 to 80 mol% of ethylene-based repeating units and 20 to 40 mol% of butene-based repeating units.

Further, the EBR melt flow rate (MF
R, 230 ° C., 2.16 kg load) is preferably in the range of 0.01 to 50 g / 10 minutes, more preferably 0.5 to 3
It is 0 g / 10 minutes.

The ethylene used in the present invention
The propylene-diene copolymer rubber (EPDM) has a content of repeating units derived from ethylene of 40 to 70.
It is preferable that the content of the repeating units derived from propylene is 30 to 60% by weight, and the content of the repeating units derived from a diene is 1 to 10% by mole. A more preferable range is 50-60 mol% of ethylene-based repeating units and 40-60% of propylene-based repeating units.
50 mol% and 3 to 6 mol% of diene-based repeating units.

Further, the melt flow rate of EPDM (MFR, 230 ° C., 2.16 kg load) is 0.01 to 50 g /
It is preferably in the range of 10 minutes, more preferably 0.
It is 1 to 30 g / 10 minutes.

The ethylene-propylene copolymer rubber (EPR), ethylene-butene copolymer rubber (EBR) and ethylene-propylene-diene copolymer rubber (EPDM) used in the present invention are basically the above-mentioned ones. It is composed of repeating units, but may be, for example, 4-methyl-pentene-1 within a range not impairing the properties of these copolymers.
Other repeating units, such as repeating units derived from other α-olefins such as, may be included up to a proportion of 10 mol% or less.

In the present invention, as the above-mentioned olefin elastomer, an olefin elastomer composition in which polyolefin and / or polyethylene is mixed can be used. The polypropylene that can be used in the present invention is not limited to a homopolymer of propylene but includes a block copolymer or a random copolymer of propylene and ethylene. In case of copolymer, ethylene content is 1
It is 0% by weight or less. Such polypropylene resin usually has a melt flow rate (MFR, 0.5 to 80 g / min).
JISK7210, 230 ° C, 2.16kg load).

The polyethylene that can be used in the present invention has a melt index (MI, load 2.16 kg, 190 ° C.) of 0.1.
〜50g / 10min, density (ASTM D1505) 0.970〜0.88
It is 5 g / cm ³ and may be copolymerized with about 20% by weight or less of another α-olefin. Examples of such polyethylene include low density polyethylene, linear low density polyethylene, and high density polyethylene, with high density polyethylene being particularly preferred. High-density polyethylene usually has a melt index (MI, load 2.16 kg, 190 ° C) of 0.1 to 50 g / 10 minutes, and 0.94 to 0.
It has a density of 97 g / cm ³ .

When polypropylene and / or polyethylene is mixed, the mixing amount is 80% by weight or less, preferably 50% by weight, based on 100% by weight of the olefin elastomer. If the mixing amount of polypropylene and / or polyethylene exceeds 80% by weight, the properties as an elastomer are lost.

The modified polyolefin elastomer as the component (c) of the thermoplastic resin composition in the present invention is the above-mentioned various olefin elastomers modified with an unsaturated glycidyl compound.

Here, the unsaturated glycidyl compound used as the modifier is a compound having an acrylamide or methacrylamide group and an epoxy group, and the unsaturated glycidyl compound represented by the following general formula (I) is preferably used. To be done.

[0028]

[Chemical 3]

[In the formula, R represents a hydrogen atom or a carbon number of 1 to 6]
Of Ar, Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and n represents an integer of 1 to 4. Among the unsaturated glycidyl compounds represented by the above general formula, glycidyl compounds represented by the following general formula are particularly preferable.

[0030]

[Chemical 4]

[Wherein R represents a hydrogen atom or a carbon number of 1 to 6]
Is an alkyl group. Such a glycidyl compound can be produced, for example, by the method described in JP-A-60-130580, and these polymerizable compounds can be used alone or in combination of two or more kinds.

The compounding amount of the modifier in the modified polyolefin varies depending on the kind of the raw material olefin-based elastomer and cannot be generally specified, but it is generally about 0.01 to 30% by weight, preferably 0.1 to 100 parts by weight of the olefin-based elastomer. 10 to 10% by weight. If the blending amount of the unsaturated glycidyl compound is less than 0.01 parts by weight, it is difficult to achieve a high graft ratio, and if it exceeds 30 parts by weight, the molecular weight of the modified olefin elastomer obtained is lowered.

Such a modified olefin elastomer can be obtained by utilizing a known modification method such as a solution method or a melt kneading method. In addition, a desired product may be appropriately selected from commercially available products and used. As a specific example of the modification method,
A modification example (graft polymerization) of an olefinic elastomer with the glycidyl compound is shown below.

That is, in the melt-kneading method, an olefin elastomer, the above-mentioned glycidyl compound and, if necessary, a catalyst are used, and these components are put into an extruder, a twin-screw kneader or the like, and heated to about 170 to 300 ° C. The modified olefin elastomer is obtained by kneading for about 0.1 to 20 minutes while heating and melting at a temperature. In the case of the solution method,
90% by dissolving the above starting materials in an organic solvent such as xylene.
Denaturation is carried out at a temperature of about 200 ° C. for 0.1 to 100 hours with stirring.

The modified olefin elastomer thus obtained has a graft ratio of about 0.1 to 10% by weight, and
Melt flow rate of about 01 to 50 g / 10 minutes (MF
R, JIS K7210, load 2.16 kg, 230 ° C).

In any of the modification methods, as a catalyst, a conventional radical polymerization catalyst such as benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, acetyl peroxide, t-butyl perbenzoate, or peroxybenzoate is used. Peroxides such as dicumyl oxide, perbenzoic acid, peracetic acid, t-butyl perpivalate, and 2,5-dimethyl-2,5-di-t-butylperoxyhexyne, and azobisisobutyronitrile. And other azo compounds can be used. The amount of the catalyst added is about 0.1 to 10 parts by weight with respect to 100 parts by weight of the glycidyl compound for modification. It is also possible to add a phenolic antioxidant during the above graft reaction.

The modified olefin elastomer (graft copolymer) thus obtained has a very small decrease in molecular weight, and thus can be a modified olefin elastomer having a high molecular weight which cannot be obtained by the conventional method. The glycidyl compound used in the method of the present invention is also
No irritating odor is generated during denaturation, and there is no discoloration as in the case of denaturation with maleic anhydride.

The thermoplastic resin composition of the present invention can be obtained by melt-kneading the above-mentioned respective components, that is, the polyamide, the olefin elastomer, and the olefin elastomer modified with the unsaturated glycidyl compound.

In the present invention, (a) polyamide,
The blending ratio of the (b) olefin-based elastomer and the (c) olefin-based elastomer modified with the unsaturated glycidyl compound is such that the ratio of the component (a) to the component (b) + (c) is (a) / (B) + (c) = 70/30 to 2/9
8, preferably 60/40 to 10/90, and the weight ratio of the component (b) to the component (c) is (b) / (c) =
5/95 to 95/5, preferably 10/90 to 90/1
It is 0.

Here, if the content of the (b) olefinic elastomer is less than 5% by weight, the resulting composition becomes a yellowish and poor-appearing elastomer, and (c) the olefinic elastomer modified with an unsaturated glycidyl compound is 5%. If it is less than wt%, it will be difficult to achieve the effect of the modified polymer.

Further, in the present invention, other substances, for example, for the purpose of strengthening or modifying the thermoplastic resin composition, for example,
Fillers and reinforcements such as glass fiber, heat stabilizers, light stabilizers,
A flame retardant, a plasticizer, an antistatic agent, a foaming agent, a nucleating agent and the like can be added and blended.

As the melt-kneading method, various conventionally known methods can be adopted. That is, a batch kneading method using a batch type kneading machine, a kneading method using a kneading machine such as a Banbury mixer, a Brabender, a kneading roll, a single-screw extruder, or a twin-screw extruder can be exemplified. The kneading temperature is 200 to 300 ° C., preferably 210.
Is in the range of to 290 ° C. If the kneading temperature is lower than 200 ° C, the compatibility of the polyamide and the polyolefin-based elastomer is insufficient, and if the temperature exceeds 300 ° C, the original properties of the resin may be impaired.

The kneading order of each component is not particularly limited, and various orders can be adopted. For example, (i) the component (a), the component (b), and the component (c) are simultaneously charged into a batch-type kneader, a Brabender, or a kneader such as a single-screw or twin-screw extruder at the same time, and they are packaged together Method of kneading, (ii) Component (a) and component (b) are simultaneously charged into an extruder, and then component (c) is charged from the middle of the barrel to be kneaded, (iii) Component (b) And the component (c) are simultaneously charged into the extruder, and then the component (a) is charged halfway. (Iv) The component (a) and the component (c) are simultaneously charged into the extruder, and then the component ( For example, a method of inserting b) halfway.

[0044]

[Function] Polyamide and olefin elastomer,
The thermoplastic resin composition of the present invention obtained by melt-kneading with an olefinic elastomer modified with an unsaturated glycidyl compound, the surface hardness, the softening temperature, the details of why the appearance is excellent is not necessarily clear, the modified olefin It is considered that this is because the system elastomer reacts with the polyamide to form a graft body, and this acts as a compatibilizer for the olefin elastomer and the polyamide.

[0045]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples. In the examples and comparative examples, the following raw material components and catalysts were used.

Polyamide nylon 6: A1030BRL manufactured by Unitika Ltd., relative viscosity η _r 2.6 (JIS K6810, measured in 98% sulfuric acid).

Polyolefin rubber Ethylene-propylene rubber (EPR): manufactured by Mitsui Petrochemical Co., Ltd .: P0180, melt flow rate (MF)
R, 230 ° C, 2.16 kg load) 6.0 g / 10 minutes.

Radical polymerization catalyst POX: Perhexin 25B [manufactured by NOF CORPORATION]

Modified polyolefin rubber Modified ethylene-propylene rubber (modified EPR): Ethylene-propylene rubber (Mitsui Petrochemical Co., Ltd .: P01
80) 100 parts by weight of organic peroxide (POX)
(Perhexin 25B: manufactured by NOF CORPORATION) 0.03 parts by weight, unsaturated glycidyl compound (AXE) represented by the following chemical formula [Kanefuchi Chemical Industry Co., Ltd.]

[0050]

[Chemical 4]

3 parts by weight were added, and the diameter was 30 mm and L /
Using a single-screw extruder with a D ratio of 23, a screw rotation speed of 6
Melt-kneaded at 0 rpm and temperature of 200 ° C. AX graft ratio: 2.6% by weight, melt flow rate (MFR, 2
30 ℃, 2.16kg load) 3.5g / 10min.

Here, the graft ratio of AXE was calculated as follows. The obtained modified olefin elastomer is dissolved in boiling xylene and reprecipitated in methanol,
The precipitated polymer was vacuum dried and hot pressed into a film having a thickness of about 50 μm. The IR of the obtained film was measured, and the ratio of the absorbance between the peak (1648 cm ^-1 ) related to the expansion and contraction of the carbonyl (C = O) bond of the modifier and the peak (840 cm ^-1 ) peculiar to isotactic polyethylene was determined. It was calculated and calculated using a calibration curve prepared in advance.

Examples 1 to 6 and Comparative Examples 1 to 7 Polyamide (nylon 6), modified polyolefin rubber (modified EPR), and olefin rubber (EPR)
Were used in the proportions shown in Table 1, and this was melt-kneaded at a screw rotation speed of 200 rpm and a temperature of 250 ° C. using a twin-screw extruder having a diameter of 45 mm to form pellets.

The Vicat softening point, elongation at break, permanent elongation, surface hardness and yellow index of the thermoplastic resin composition thus obtained were measured. The results are also shown in Table 1.

[0055]

[Table 1]

[0056]

[Table 2]

The methods for measuring the physical properties shown in Table 1 above are as follows. (1) Vicat softening point: measured by ASTM D1525. (2) Elongation at break: Measured according to JIS K6301. (3) Permanent elongation: Measured according to JIS K6301. (4) Surface hardness: measured by ASTM D2240 (Shore D). (5) Yellow index: Measured according to JIS K7103.

As is clear from Table 1, polyamide,
Comparing the thermoplastic resin composition of the present invention comprising an olefin elastomer and a modified elastomer with the resin (composition) of the comparative example, Comparative Example 1 consisting of only the polyolefin (EPR) and polyamide (nylon 6) and polyolefin ( Comparative Examples 2, 4 and 6 consisting of EPR only have good coloring degree (yellow index), but are inferior in Vicat softening point, elongation at break and surface hardness. On the contrary, polyamide and modified polyolefin (modified EP
Comparative Examples 3, 5 and 7 consisting only of R) have good Vicat softening point, elongation at break and surface hardness, but poor coloring degree (yellow index).

That is, it can be seen that the thermoplastic resin composition of the present invention is excellent in good balance in all of Vicat softening point, elongation at break, permanent elongation, surface hardness and yellow index.

[0060]

As described above in detail, the thermoplastic resin composition of the present invention comprises polyamide, an olefin-based elastomer and a modified olefin-based elastomer, and has good impact resistance and elasticity, and heat resistance (softening temperature). ) Is good and the composition is excellent in appearance with little coloring. Such a thermoplastic resin composition of the present invention is suitable as a resin composition for various engineering plastics, particularly various sealing materials, tubes, industrial parts, office supplies, sports equipment, toys and the like.

[Chemical 2]

[Chemical 5]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Fujita 1-3-1 Nishitsurugaoka, Oi-cho, Iruma-gun, Saitama Tonen Research Institute

Claims (1)

[Claims] 1. A polyamide, (b) an olefin elastomer, and (c) the following general formula (I): [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms having at least one glycidyloxy group, and n
Represents an integer of 1 to 4. ] The olefinic elastomer modified with the unsaturated glycidyl compound shown by these is contained, and the ratio of a component (a) and a component (b) + (c) is (a) / ((b) + (c) by weight ratio. ) = 70/30 to 2/98, and the ratio of the component (b) to the component (c) is (b) by weight.
/ (C) = 5 / 95-95 / 5, The thermoplastic resin composition characterized by the above-mentioned.