JPH06234897A - Composition for blow molding - Google Patents

Abstract

PURPOSE:To obtain a composition for blow molding which has good heat resistance, high mechanical strength and high resistance to antifreeze, and shows excellent blow moldability with reduced drawdown. CONSTITUTION:The composition contains (a) 50 to 95wt.% polyamide resin, (b) 5-50wt.% polyolefin modified with an unsaturated carboxylic acid or its anhydride or a mixture thereof with a polyolefin where the molar ratio of the terminal amino groups of the polyamide resin to the carboxyl groups is 1 to 10 and the component (b) is uniformly dispersed in the polyamide resin matrix in an average particle size of 0.5 to 5mum in diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molding composition containing a polyamide resin and a polyolefin, which has particularly good heat resistance, mechanical strength and antifreeze resistance, and has little drawdown and blow moldability. It relates to excellent blow molding compositions.

[0002]

BACKGROUND OF THE INVENTION Polyamide resins are excellent in gasoline barrier properties, mechanical strength, heat resistance, etc., and are therefore suitable for plastic parts that substitute various metals. For example, in order to reduce the weight of automobiles, radiator tanks, heater pipes and the like are manufactured by blow molding a polyamide resin. For such parts, it is common to use nylon 6 or nylon 66, which is particularly excellent in strength and heat resistance, to which a reinforcing material such as glass fiber is added.

However, the polyamide resin has a problem that it is inferior in water resistance, moldability, chemical resistance and antifreeze resistance. The above-mentioned insufficient properties are generally possessed by polyolefins. Therefore, it is possible to mix a polyamide resin and a polyolefin,
Since the polyamide resin and the polyolefin have poor compatibility with each other, various compositions have been proposed in which they are compatible with each other.

JP-B-61-26939 discloses (a) a polyamide resin, (b) a modified polymer obtained by graft-copolymerizing an ethylenically unsaturated carboxylic acid or an anhydride thereof with a polyolefin resin, and (c) a fibrous form. Includes reinforcements and (a) ingredients
(b) The components are (a) :( b) = 70: 30 to 95: 5 by weight, and
Disclosed is a composition containing the component (c) in a proportion of 40 to 200 parts by weight based on 100 parts by weight of the total of the components (a) and (b).

JP-A-60-170664 discloses that the number average molecular weight is 2
20 to 92 parts by weight of a polyamide resin (A) of 000 or more, 50 to 3 parts by weight of modified polyolefin (B), and an average diameter of 3 to 20 μ
m, and glass fiber (C) 5-50 with an average length of 50-600 μm
Part by weight is mixed (however, (A) + (B) + (C) above
Of 100 parts by weight) is disclosed.

Further, JP-A-62-241940 discloses that [A] olefin polymer: 30 to 95% by weight, [B] polyamide: 5 to
70% by weight, and [C] glass fiber using an acrylic resin as a sizing agent: 5-200 parts by weight ([A] + [B]
= 100 parts by weight), a plastic composition for forming a radiator tank of an automobile is disclosed.

However, although the above-mentioned conventional composition has improved compatibility between the polyamide resin and the polyolefin, it has a low melt viscosity, so that drawdown tends to occur in blow molding, and thus the obtained blow molded product is There is a problem that the wall thickness tends to be uneven.

Therefore, an object of the present invention is to provide a blow molding composition which has good heat resistance, mechanical strength and antifreeze resistance, and has little drawdown and excellent blow moldability.

[0009]

As a result of earnest research in view of the above object, the present inventors have found that the terminal amino group of a polyamide resin in a composition containing a polyamide resin and a modified polyolefin with an unsaturated carboxylic acid or an anhydride thereof. The molar ratio of the radical to the carboxyl group of the modified polyolefin is 1 to 1
Within the range of 0 and forming a specific morphology in which the polyolefin is uniformly dispersed in the polyamide resin matrix phase, the melt viscosity of the composition is significantly increased, drawdown is less likely to occur, and the heat resistance of the polyamide resin is reduced. The inventors have found that a composition suitable for blow molding can be obtained while maintaining the properties, and have arrived at the present invention.

That is, the blow molding composition of the present invention comprises:
(a) a polyamide resin in an amount of 50 to 95% by weight, and (b) a modified polyolefin with an unsaturated carboxylic acid or an anhydride thereof, or a polyolefin resin mixture comprising a polyolefin and the modified polyolefin in an amount of 5 to 50% by weight. And the ratio of the number of moles of the terminal amino groups of the polyamide resin to the number of moles of the carboxyl groups in the modified polyolefin with the unsaturated carboxylic acid or its anhydride is 1 to
10 and is characterized in that the component (b) forms a dispersed phase having an average diameter of 0.5 to 5 μm, which is uniformly dispersed in the polyamide resin matrix phase.

The present invention is described in detail below. [A] Composition Components First, each composition component of the blow molding composition of the present invention will be described.

(A) Polyamide Resin In the present invention, (a) the polyamide resin includes hexamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4- or 2,4,4, -trimethylhexamethylenediamine, 1,3- or 1,4-bis (aminomethyl)
Aliphatic, alicyclic or aromatic diamines such as cyclohexane, bis (p-aminocyclohexylmethane), m- or p-xylylenediamine, and adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid Polyamides prepared from aliphatic, cycloaliphatic or aromatic dicarboxylic acids such as isophthalic acid, 6
From polyamides prepared from aminocarboxylic acids such as aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, polyamides prepared from lactams such as ε-caprolactam, ω-dodecalactam, and components thereof And a mixture of these polyamides. Specific examples include nylon 6, nylon 66, nylon 610, nylon 9, nylon 6/66, nylon 66/610, nylon 6/11, nylon 6/12, nylon 12, nylon 46, and amorphous nylon. . Of these, nylon 6 and nylon 66 are preferable in terms of good rigidity and heat resistance.

The molecular weight of the above polyamide resin is not particularly limited, but usually one having a relative viscosity η _r (measured in JIS K6810, 98% sulfuric acid) of 0.5 or more is used, and among them, one having a relative viscosity of 2.0 or more has excellent mechanical strength. Is preferable. The amount of terminal amino groups in the above polyamide resin (Korshak-Zamyationa
Method (Inverse titration method) (Chem.Abs. 40 , 4665, '46, ibid. 42 , 615
2, '48)) is 0.01-0.1 meq / g, especially 0.02
It is preferably about 0.08 meq / g. However, the amount of terminal amino groups of the polyamide resin in the composition needs to be a specific ratio with respect to the number of moles of the carboxyl groups of the modified polyolefin, as described later.

(B) Due to the unsaturated carboxylic acid or its anhydride
Modified Polyolefin In the modified polyolefin, a crystalline polyolefin and an olefin elastomer can be used as the polyolefin to be modified.

As the crystalline polyolefin, ethylene, propylene, butene-1, pentene-1, hexene-1,
Homopolymer of α-olefin such as 4-methylpentene-1
Examples thereof include a copolymer of ethylene and propylene or another α-olefin, or a copolymer of two or more kinds of these α-olefins. Of these, polypropylene is particularly preferable. Polypropylene is not limited to homopolymers, and the propylene component is 50 mol% or more, preferably 80
Random or block copolymers with other α-olefins containing more than mol% can also be used. As the comonomer copolymerized with propylene, there are ethylene and other α-olefins, and ethylene is particularly preferable.

Melt flow rate of the above polypropylene
The (MFR, 230 ° C., 2.16 kg load) is preferably 0.01 to 50 g / 10 min, and particularly preferably 0.1 to 5 g / 10 min.

Further, as the olefin elastomer, 2 of α-olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1 and the like are used.
Examples thereof include one or three or more copolymer rubbers, or a copolymer rubber of an α-olefin and another monomer. Above α
-The copolymer rubber of two or more kinds of olefins is typically an ethylene-propylene copolymer rubber (EP
R), ethylene-butene copolymer rubber (EBR), and ethylene-propylene-diene copolymer rubber (EPDM). Ethylene-propylene-diene copolymer rubber (EP
The diene in (DM) includes dicyclopentadiene and 1,4-
Non-conjugated dienes such as hexadiene, cyclooctadiene and methylene norbornene or conjugated dienes such as butadiene and isoprene can be used. Further, vinyl acetate, acrylic acid ester and the like can be used as the other monomer copolymerized with the α-olefin. A typical example of the copolymer of α-olefin and another monomer is ethylene-vinyl acetate copolymer (EVA).

Ethylene-propylene copolymer rubber (EPR)
Preferably has an ethylene content of 40 to 90 mol% and a propylene content of 10 to 60 mol%. A more preferable range is 50 to 90 mol% of ethylene and 10 to 10 of propylene.
It is 50 mol%. EPR melt index (190 ℃,
2.16 kg load) is preferably in the range of 0.5 to 15 g / 10 minutes, more preferably 3 to 9 g / 10 minutes.

The ethylene-butene copolymer rubber (EBR) is
The ethylene content is preferably 60 to 97 mol%, and the butene-1 content is preferably 3 to 40 mol%. A more preferred range is 80 to 95 mol% for ethylene and 5 to 20 mol% for butene-1. EBR melt index (190 ° C, 2.16
(kg load) is preferably in the range of 0.5 to 15 g / 10 minutes, more preferably 3 to 9 g / 10 minutes.

The ethylene-propylene-diene copolymer (EPDM) has an ethylene content of 40 to 89 mol%, a propylene content of 10 to 59 mol%, and a diene content of 1 to 10 mol%. % Is preferable. The Mooney viscosity ML _{1 + 8} (100 ° C.) of EPDM is preferably in the range of 40 to 100, more preferably 60 to 80.

Ethylene-propylene copolymer rubber (EP
R), ethylene-butene copolymer rubber (EBR) and ethylene-propylene-diene copolymer rubber (EPDM) are, for example, 4-methylpentene-1 within a range not impairing the characteristics of these copolymers. Other α-olefins may be contained up to a proportion of 10 mol% or less.

Examples of the unsaturated carboxylic acid or its anhydride which is a monomer for modifying polyolefin as described above include monocarboxylic acids such as acrylic acid and methacrylic acid, dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, Dicarboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, endo-bicyclo- [2,2,1] -5-heptene-2,3-dicarboxylic acid anhydride (hymic acid anhydride), and the like, and particularly dicarboxylic acid Acids and their anhydrides are preferred.

The modified polyolefin with the modifying monomer may be a block copolymer, a graft copolymer, a random copolymer or an alternating copolymer.

Regarding the melt viscosity of the modified polyolefin as described above, in the case of modified polypropylene, the melt flow rate (MFR, 190 ° C., 1.05 kg load) is preferably 0.1 to 500 g / 10 minutes, and in the case of modified polyethylene. , Melt flow rate (MFR, 190 ℃, 1.05kg load) is 0.1-50
It is preferably 0 g / 10 minutes.

In the case of modified ethylene-propylene copolymer rubber, the melt flow rate (MFR, 190 ° C., 2.16
(kg load) is preferably 0.1 to 500 g / 10 min. In the case of modified ethylene-butene copolymer rubber, melt flow rate (MFR, 190 ℃, 2.16 kg load) is 0.1 to 500 g / 1
It is preferably 0 minutes.

The modified crystalline polyolefin as described above and the modified olefin elastomer may be used alone or in combination.

The content of the unsaturated carboxylic acid or its anhydride in the modified polyolefin is 0.05 to 16% by weight, particularly 0.1% by weight.
It is preferably about 13% by weight. Specifically, it is preferably 0.05 to 10% by weight, particularly 0.1 to 8% by weight in the case of maleic anhydride, and 0.08 to 16% by weight, particularly preferably 0.16 to 13% by weight in the case of hymic acid anhydride. . However,
As described later, the molar ratio of the terminal amino group in the polyamide resin in the composition to the carboxyl group of the modified polyolefin needs to be within a specific range.

The modified polyolefin can be produced by either a solution method or a melt kneading method. In the case of the solution method, the polyolefin, the modifying unsaturated carboxylic acid (or acid anhydride) and the catalyst are dissolved in an organic solvent such as xylene,
Stir at a temperature of ~ 140 ° C. In the case of the melt kneading method, the above starting materials are put into an extruder, a twin-screw kneader, or the like,
Knead while heating to a temperature of 150-250 ℃.
In any case, a usual radical polymerization catalyst can be used as a catalyst, for example, benzoyl peroxide, lauroyl peroxide, ditert-butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide, Peroxides such as peroxybenzoic acid, peroxyacetic acid and tertiary butyl peroxypivalate, and diazo compounds such as azobisisobutyronitrile are preferable. The amount of the catalyst added is about 1 to 100 parts by weight per 100 parts by weight of the unsaturated carboxylic acid for modification or its anhydride.

In the present invention, it is also possible to use a mixture of the above modified polyolefin and an unmodified polyolefin. As the unmodified polyolefin, the same polyolefin as the above-mentioned polyolefin to be modified can be used. In the case of a mixture of modified polyolefin and unmodified polyolefin, the mixing ratio of both is 100 in total.
It is preferable that the modified polyolefin is 5% by weight or more, especially 10 to 80% by weight. However, even in the case of the mixture, the molar ratio of the terminal amino group in the polyamide resin in the composition to the carboxyl group of the modified polyolefin needs to be within a specific range as described later.

The following nine cases are listed as combinations of the polyolefin resin mixture. Modified crystalline polyolefin + crystalline polyolefin Modified crystalline polyolefin + olefin elastomer Modified olefin elastomer + olefin elastomer Modified olefin elastomer + crystalline polyolefin Modified crystalline polyolefin + Modified olefin elastomer + crystalline polyolefin Modified crystalline polyolefin + Modified olefin elastomer + olefin elastomer Modified crystalline polyolefin + crystalline polyolefin +
Olefin-based elastomer Modified olefin-based elastomer + Crystalline polyolefin + Olefin-based elastomer Modified crystalline polyolefin + Modified olefin-based elastomer + Crystalline polyolefin + Olefin-based elastomer Among these, the combination of and is particularly preferable.

[B] Blending Ratio In the blow molding composition of the present invention, the blending ratio of the resin component (polyamide resin + modified polyolefin (adding polyolefin as necessary)) is 10 in total.
As 0% by weight, the content of the polyamide resin is 50 to 95% by weight, and the content of the modified polyolefin (addition of polyolefin as necessary) is 5 to 50% by weight. 50% by weight of polyamide resin
Below (when the modified polyolefin exceeds 50% by weight)
, Heat resistance and mechanical strength are insufficient, and if the polyamide resin exceeds 95% by weight (modified polyolefin is less than 5% by weight), moldability and antifreeze resistance become insufficient, and the cost increases. . The preferred blending ratio is 55 to 90% by weight of the polyamide resin and 10 to 45% by weight of the modified polyolefin (adding a polyolefin if necessary).

[C] A terminal amino group of polyamide resin
In the present invention, the polyamide resin and the modified polyolefin are blended at the blending ratio as described above, but the molar ratio of terminal amino group / carboxyl group in the composition is in the range of 1 to 10. It is within.

This is because of the following reasons. That is, when the modified polyolefin and the polyamide resin are melt-kneaded, the carboxyl groups in the modified polyolefin react with the terminal amino groups of the polyamide resin to form a modified polyolefin-polyamide graft copolymer. The larger the number, the larger the melt viscosity.
When the molar ratio of terminal amino group / carboxyl group is 10 or more, the viscosity of the composition required as a resin for blow molding cannot be obtained. When the molar ratio of terminal amino group / carboxyl group is less than 1, the amount of the modified polyolefin-polyamide graft copolymer formed is large, but the ratio of the modified polyolefin in the entire composition becomes too large (the ratio of the polyamide resin is small. Therefore, the physical properties of the polyamide resin such as mechanical strength and heat resistance are deteriorated. The preferred terminal amino group / carboxyl group molar ratio is within the range of 1 to 7.

[D] (b) Component polyamide resin matrix
The average diameter of the dispersed phase in the polyamide resin matrix phase components in the composition in an average diameter present invention the dispersed phase (b) (polyolefin resin mixture consisting of modified polyolefin, or a polyolefin and the modified polyolefin) in box phase is , 0.5 ~
It is within the range of 5 μm. The average diameter of this dispersed phase is 0.5 μm
If it becomes smaller, the compatibilization of the polyolefin will proceed excessively, so that the properties of the polyamide resin and the component (b) will be averaged, and the heat resistance will decrease. Further, if the average diameter of the dispersed phase of the component (b) exceeds 5 μm, the impact resistance, especially the impact resistance at low temperature water absorption is deteriorated.

[E] Other Components Inorganic Filler The blow molding composition of the present invention may be added with an inorganic filler such as glass fiber, talc, calcium carbonate, mica, or whisker for the purpose of reinforcing the composition. it can. Of these, glass fiber is particularly preferable.

As the glass fiber, both chopped strands and rovings can be used, but those having an average fiber diameter of 6 to 20 μm and an aspect ratio of 100 to 500 are preferable. In addition, it is preferable to use those which have been surface-treated with a silane coupling agent and / or a binding agent made of a polymer having a carboxyl group or an acid anhydride group. Such surface treatment improves the adhesion between the glass fiber and the polyamide resin.

The compounding amount of the above-mentioned inorganic filler is 50 parts by weight or less, particularly 10 parts by weight, based on 100 parts by weight of the total of the resin components.
It is preferably about 30 parts by weight. The amount of inorganic filler compounded
If it exceeds 50 parts by weight, the moldability is lowered, making it difficult to produce a molded product, and the mechanical strength is rather lowered.

For the purpose of modifying the blow molding composition of the present invention, other additives such as a heat stabilizer, an antioxidant, a light stabilizer, a flame retardant, a plasticizer and an antistatic agent. , A release agent and a foaming agent can be added.

[F] Production Method The blow molding composition of the present invention is obtained by heating and melting the above-mentioned components at 200 to 320 ° C. using a kneading device such as an extruder such as a single-screw extruder or a twin-screw extruder. It can be obtained by kneading in the state. At this time, in order to make the average diameter of the dispersed phase of the component (b) within the above range, for example, JP-A-1-24
It is preferred to use a twin-screw extruder as described in 0561. When glass fibers are mixed, the glass fibers may be added from the beginning together with the polyamide resin and the modified polyolefin (polyolefin if necessary), or after the above resin components have been melt-kneaded to some extent, they may be added in the middle. Good.

The blow molding composition of the present invention thus obtained can be molded into a desired shape by a blow molding method. The method of blow molding is not limited to the ordinary method, and can be applied to a three-dimensional bending blow molding method (for example, IHI method or Placo method).

[0041]

In the present invention, the molar ratio of the terminal amino group of the polyamide resin to the carboxyl group of the modified polyolefin in the composition containing the polyamide resin and the modified polyolefin with an unsaturated carboxylic acid or an anhydride thereof is 1
Within the range of 10 to 10, and because the polyolefin forms a specific morphology uniformly dispersed in the polyamide resin matrix phase, the melt viscosity of the composition is greatly increased, the blow moldability is improved, and the drawability is improved. Down is much less likely to occur.

Although the reason why such an effect is obtained is not always clear, when the modified polyolefin and the polyamide resin are melt-blended, the carboxyl group of the modified polyolefin and the terminal amino group of the polyamide resin react with each other and the modified polyolefin- A polyamide graft copolymer is formed. Since the melt viscosity of the composition can be increased by increasing the proportion of the graft copolymer in the composition and decreasing the proportion of the remaining modified polyolefin, the molar ratio of terminal amino group / carboxyl group is from 1 to 1. It is considered that the reason for limiting to 10 is that the resin has a viscosity suitable as a resin for blow molding.

Further, the average diameter of the polyolefin dispersed phase is 0.
By adjusting the thickness to 5 to 5 μm, the compatibilization is appropriately adjusted,
The composition for blow molding can be prepared without impairing the heat resistance and mechanical properties of the polyamide resin.

[0044]

The present invention will be described in more detail by the following examples. The following resin components were used as raw materials. [1] Polyamide resin Nylon 6 Ny6: [EMS F50, manufactured by EMS Corporation, relative viscosity (JIS K6810, measured in 98% sulfuric acid) [η _r ] 6.0, Kors
hak-Zamyationa method (inverse titration method) (Chem.Abs.40,466
5, '46, ibid. 42,6152, '48)
0.022 meq / g] [2] Modified polyolefin Maleic anhydride modified polypropylene CMPP: [Propylene homopolymer (Tonen Chemical Co., Ltd.)
Manufactured by E200X, modified with maleic anhydride using Perhexin 2.5B (manufactured by NOF CORPORATION) as an initiator, and added amount of maleic anhydride is 0.3% by weight (0.03).
m equivalent / g), melt flow rate (190 ° C, 1050 g load) 40 g / 10 minutes] [3] Modified olefin elastomer Maleic anhydride modified ethylene-butene copolymer rubber CMEBR: [Ethylene-butene copolymer rubber ( EBM2041P manufactured by Nippon Synthetic Rubber Co., Ltd., modified with maleic anhydride using Perhexin 2.5B (manufactured by NOF CORPORATION) as an initiator, and the addition amount of maleic anhydride
0.8 wt% (0.08 meq / g), melt flow rate
(190 ° C., 2160 g load) 1.5 g / 10 min] [4] Polyolefin polypropylene HPP: [Tonen Kagaku KK, E-200X] [5] Glass fiber GF: [Asahi Fiber Glass KK, 03MAFT2A, Average fiber diameter 13 μm, aspect ratio 230, surface treatment with maleic anhydride]

Examples 1 to 9 and Comparative Examples 1 to 9 Nylon (Ny6), polypropylene (BPP) and a modified polyolefin with maleic anhydride (CMPP or CMEBR) were mixed in the proportions shown in Table 1, and the twin screw extruder was used. (45 mmφ, L / D = 28) was charged from the main hopper. Further, glass fibers (GF) were added from the middle of the twin-screw extruder at a ratio shown in Table 1 with respect to a total of 100 parts by weight of the resin component and kneaded at 250 ° C. and 200 rpm to obtain pellets of the composition. .

Using the obtained pellets, a test piece for a physical property test described later was prepared by injection molding, and the specific gravity, tensile strength, bending strength and heat distortion temperature were measured. The results are shown in Table 2.

Using the above pellets, a parison was extruded at a rotation speed of 30 rpm and a temperature of 240 ° C. from a circular die having an outer diameter of 32 mmφ and an inner diameter of 13 mmφ installed in a 50 mmφ extruder. At that time, the time to reach the length of 10 cm from the bottom surface of the die (t ₁₀ ) and the time to reach the length of 60 cm (t ₆₀
) And were measured, and the ratio (t ₆₀ / t ₁₀ ) was taken as the drawdown ratio. The results are shown in Table 2.

Table 1 Composition (parts by weight) Example 1 Example 2 Example 3 Example 4 Example 5 Ny6 60 60 60 60 70 CMPP-10 30 20 10 CMEBR 10 ----- HPP 30 30 10 20 20 GF 25 25 25-25 Molar ratio of terminal amino group / carboxyl group ^* 1.6 4.3 1.4 2.0 5.0

Table 1 (continued) Composition (parts by weight) Example 6 Example 7 Example 8 Example 9 Ny6 70 80 90 70 CMPP-10 10 10 CMEBR 10 --- HPP 20 10-20 GF 25 25 25-Molar ratio of terminal amino group / carboxyl group ^*  1.9 5.8 6.5 5.0

Table 1 Composition (parts by weight) Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Ny6 100-60 50 CMPP-100-50 CMEBR --- HPP--40-GF 25 25 25 25 Terminal amino Group / carboxyl group molar ratio ^* − − − 0.7

Table 1 (continued) Composition (parts by weight) Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Ny6 70 70 80 90 70 CMPP 3−2 5 3 CMEBR−30 −−− HPP 27-18 5 27 GF 25 25 25 25 −Molar ratio of terminal amino group / carboxyl group ^*  16.8 0.6 28.8 12.9 16.8 Note) *: The terminal amino group in nylon 6 and modified polypro
The molar ratio with the carboxyl group in pyrene.

Table 2 Physical Properties Example 1 Example 2 Example 3 Example 4 Example 5 Specific gravity ⁽¹⁾ 1.17 1.17 1.17 1.03 1.19 Tensile strength ⁽²⁾ 750 1200 1000 550 1200 Bending strength ⁽³⁾ 1100 1600 1200 750 1600 Heat distortion temperature ⁽⁴⁾ 140 150 145 60 160 Drawdown ratio ⁽⁵⁾ ○ ○ ○ ○ ○ (b) Component dispersion diameter ⁽⁶⁾ 1.2 2.3 1.1 1.1 1.9

Table 2 (continued) Physical Properties Example 6 Example 7 Example 8 Example 9 Specific gravity ⁽¹⁾ 1.19 1.22 1.25 1.06 Tensile strength ⁽²⁾ 800 1200 1200 630 Bending strength ⁽³⁾ 1200 1650 1700 760 Heat distortion temperature ⁽⁴⁾ 140 165 170 60 Drawdown ratio ⁽⁵⁾ ○ ○ ○ ○ (b) Dispersion diameter of component ⁽⁶⁾ 1.1 1.1 1.2 1.1

Table 2 (continued) Physical Properties Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Specific gravity ⁽¹⁾ 1.30 1.10 1.17 1.17 Tensile strength ⁽²⁾ 1200 700 800 600 Bending strength ⁽³⁾ 1700 850 850 650 Heat distortion temperature ⁽⁴⁾ 170 120 120 120 Drawdown ratio ⁽⁵⁾ × × × × (b) Dispersion diameter of component ⁽⁶⁾ − − 10 0.3

Table 2 (continued) Physical properties Comparative example 5 Comparative example 6 Comparative example 7 Comparative example 8 Comparative example 9 Specific gravity ⁽¹⁾ 1.19 1.19 1.22 1.25 1.19 Tensile strength ⁽²⁾ 1200 800 900 1200 630 Bending strength ^{(3 )} 1600 1100 1200 1700 760 Heat distortion temperature ⁽⁴⁾ 160 140 150 170 60 Drawdown ratio ⁽⁵⁾ △ △ × × × (b) Dispersion diameter of component ⁽⁶⁾ 9 0.3 10 1.2 9

(1) Specific gravity: Measured according to ASTM D792. (2) Tensile strength: measured by ASTM D638 (Unit: kg / c
m ² ). (3) Bending strength: Measured by ASTM D790 (Unit: kg / c
m ² ). (4) Heat distortion temperature: When the temperature of a 110 mm × 4 mm × 12.7 mm test piece subjected to a load of 18.6 kg when the temperature is raised at a constant rate (2 ° C / min), the temperature at which the test piece is bent by 0.25 mm is ASTM Measured by D648 (Unit: ° C). (5) Drawdown ratio: Outer diameter 32 installed in an extruder with a diameter of 50 mm
When a parison is extruded from a circular die with a diameter of mmφ and an inner diameter of 13 mmφ at a rotation speed of 30 rpm and a temperature of 240 ° C, the time required to reach the length of 10 cm from the bottom surface of the die (t ₁₀ ) and the length of 60 cm are reached. From the ratio t ₆₀ / t ₁₀ to the time (t ₆₀ ),
The following criteria evaluated. ○: Drawdown ratio of 4.5 or more △: Drawdown ratio of 2.5 or more and less than 4.5 ×: Drawdown ratio of less than 2.5 (6) (b) Dispersion diameter of component: Part of the parison obtained in (5) was cut and freeze fractured. The post fracture surface was etched with hot xylene, observed with SEM, and image-processed for calculation (unit: μm).

As is clear from Table 2, the compositions of the respective examples were good in tensile strength, bending strength, heat distortion temperature and drawdown ratio, and had improved blow moldability.

[0058]

As described in detail above, in the present invention, the terminal amino group of the polyamide resin and the carboxyl group of the modified polyolefin in the composition containing the polyamide resin and the modified polyolefin with an unsaturated carboxylic acid or an anhydride thereof. Since the molar ratio with the group is within the range of 1 to 10, the melt viscosity of the composition is significantly increased, the blow moldability is improved, and drawdown is not significantly generated. Further, since the dispersed phase of polyolefin (modified polyolefin or composed of polyolefin and modified polyolefin) is within the range of 0.5 to 5 μm, a blow molded product can be obtained without impairing the heat resistance and mechanical strength of the polyamide resin.

The composition of the present invention as described above is suitable for use in automobile parts such as radiator tanks and heat pipes, parts for household electric appliances and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication C08L 77/00 LQS 9286-4J (72) Inventor Tadashi Sezume 3 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 Tonen Chemical Co., Ltd. Technology Development Center

Claims (1)

[Claims] 1. (a) 50 to 95% by weight of polyamide resin,
(b) A modified polyolefin with an unsaturated carboxylic acid or an anhydride thereof, or a composition containing 5 to 50% by weight of a polyolefin resin mixture consisting of the polyolefin and the modified polyolefin, wherein the terminal amino group of the polyamide resin is The ratio of the number of moles and the number of moles of the carboxyl group in the modified polyolefin with the unsaturated carboxylic acid or its anhydride is 1 to 10 and the average of the component (b) uniformly dispersed in the polyamide resin matrix phase. Diameter
A blow molding composition, characterized in that it forms a dispersed phase of 0.5 to 5 μm.