JPH0496969A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition without generating draw down in blow molding, comprising a polyamide having a specific viscosity, polyolefin and/or an elastomer and a modified elastomer and/or a modified polyolefin. CONSTITUTION:The objective thermoplastic resin composition contains (A) 60-90wt.% polyamide (preferably nylon 6 or nylon 66, etc.) having >=4, preferably 4.5-6 relative viscosity, (B) 1-35wt.% rubber selected from B1: polyolefin and/or B2: an elastomer, preferably an ethylene-butylene copolymer rubber, ethylene- propylene-diene copolymer rubber and styrene-based copolymer rubber and (C) 1-35wt.% modified elastomer and/or modified polyolefin obtained by reacting B2 and/or B1 with an unsaturated carboxylic acid (anhydride) and has <=1g/10min melt flow rate.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermoplastic resin composition suitable for various blow-molded containers, automobile parts, structural members, etc. This invention relates to a thermoplastic resin composition that has excellent impact resistance and the like and does not cause drawdown during blow molding.

[Prior art and problems to be solved by the invention] Polyamides such as nylon have excellent chemical resistance and gas barrier properties.
Because it is a material with excellent properties such as durability and mechanical strength, it is widely used in various small containers and barrier materials in multilayer molded products.

However, when a polyamide resin is used alone, the drawdown during blow molding becomes large, making it unsuitable for manufacturing parisons for medium to large blow molded products with a length of 1 m or more.

In order to prevent the second drawdown, it is conceivable to increase the degree of polymerization of polyamide to increase its viscosity, but there is a limit due to technical problems in increasing the degree of polymerization of polyamide, problems with manufacturing costs, etc. Furthermore, when the viscosity of polyamide is increased, other problems arise in the molding process, such as the need to increase the driving horsepower of the extrusion screw.

However, polyamides are not only used alone, but are often used in combination with resins such as polyolefins.

This is done to overcome the disadvantages of polyamides, which generally have poor impact resistance and water absorption.

As an example of improving physical properties by adding polyolefin to polyamide, for example, (a) 50 to 99 parts by weight of polyamide and (b) alicyclic carbon having a cis-type double bond in the ring in polyolefin or olefin elastomer. There is a polyamide composition comprising 50 to 1 part by weight of a modified polyolefin or a modified olefin elastomer to which 0.001 to 10 mol% of at least one compound selected from the group consisting of acids or functional derivatives thereof is added (JP-A No. (Sho 55-165952).

In addition, 1 to 98 parts by weight of polyolefin (a), 1 to 49 parts by weight of modified polyolefin (b) obtained by reacting polyolefin with an unsaturated carboxylic acid or its derivative, and 1 to 98 parts by weight of polyamide (c) (however, (a+ ten (bj
+ (c) = 100 parts by weight), low crystalline ethylene-α
- 5 to 50 parts by weight of a modified ethylene-α-olefin copolymer (d) obtained by reacting an olefin copolymer with an unsaturated carboxylic acid or a derivative thereof, and a metal compound (e). There is also known a thermoplastic resin composition containing 0.5 to 5 times the molar amount of acid added (Japanese Patent Application Laid-Open No. 62-241941).

As mentioned above, not only polyamides are used as the main component and polyolefins are added thereto, but polyamides are also added as an improvement to polyolefin compositions. For example, propylene polymer (8195-5
Parts by weight, 5 to 95 parts by weight of polyamide (b) and (a)
10(b) = 100 parts by weight, X-ray crystallinity 0-30% and propylene content 50-70 mol%
propylene/α-olefin random copolymer +c+
Propylene consisting of 1 to 80 parts by weight of a modified propylene/α-olefin copolymer (d) obtained by graft-modifying 0.01 to 5 parts by weight of a graft monomer selected from unsaturated carbonic acids or derivatives thereof to 1 to 80 parts by weight. There is a polymer composition (JP-A-60-110740). Also, (a
30 to 98 parts by weight of polypropylene, (b) 1 to 69 parts by weight of polyamide, and (c) a mixture of polypropylene and a low-crystalline ethylene/α-olefin copolymer are reacted with an unsaturated carboxylic acid or a derivative thereof. 1 to 49 parts by weight of a modified polyolefin (provided that (a) 10 (bl)
There is also a polypropylene composition consisting of + (c1=100 parts by weight) (Japanese Patent Application Laid-Open No. 158739/1983).

Although each of the above compositions has improved impact resistance, surface gloss, etc., the drawdown resistance during blow molding is insufficient. For this reason, each of the above-mentioned resin compositions is not suitable for manufacturing large-sized blow-molded products by extrusion blow-molding a parison.

Therefore, an object of the present invention is to solve the above-mentioned problems, and to provide good surface gloss, chemical resistance, impact resistance, etc.
An object of the present invention is to provide a thermoplastic resin composition that does not cause drawdown during blow molding and has excellent moldability.

[Means to solve the problem]

As a result of intensive research in view of the above problems, the present inventors have discovered that a composition containing a polyamide having a specific viscosity, a polyolefin and/or an elastomer, and a modified elastomer and/or a modified polyolefin in a specific ratio has a specific The inventors have found that the material has a high melt flow rate value, is good in each of the physical properties described above, and can prevent drawdown during molding, and has conceived the present invention.

That is, the thermoplastic resin composition of the present invention comprises (a) a polyamide 60-90 having a relative viscosity (η1.1) of 4.0 or more;
(b) polyolefin and/or elastomer 1 to 35% by weight;
(c) 1 to 35% by weight of a modified elastomer and/or modified polyolefin obtained by reacting an elastomer and/or polyolefin with an unsaturated carboxylic acid or its anhydride, and the melt flow rate of the entire composition ( 240℃,
2.16 kg load, except for polyamide 66-containing compositions, which are characterized by a force of 0 g/10 minutes or less at 270° C. and a 2.16 kg load.

The present invention will be explained in detail below.

The polyamide (a) used in the present invention includes hexamethylene diamine, decamethylene diamine, dodecamethylene diamine, 2.2.4- or 2.4.4° trimethylhexamethylene diamine, 1.3- or 1.
4-bis(aminomethyl)cyclohexane, his(p-
aliphatic, cycloaliphatic or aromatic diamines such as m- or p-xylylene diamine (aminocyclohexylmethane), m- or p-xylylene diamine; Polyamide produced from aliphatic, alicyclic or aromatic dicarboxylic acid, 6-aminocaproic acid, 11-
Polyamides produced from aminocarboxylic acids such as aminoundecanoic acid and 12-aminododecanoic acid, polyamides produced from lactams such as ε-caprolactam and ω-dodecalactam, and copolyamides consisting of these components, or these. Mixtures of polyamides are mentioned. Specifically, nylon 6, nylon 66, nylon 610, nylon 9, nylon 6/66, nylon 66/610, nylon 6/11, nylon 6/12.
, nylon 12, nylon 46, amorphous nylon, etc. Among these, nylon 6, nylon 66, and copolymers of both are preferred because of their good rigidity and heat resistance.

The molecular weight of this polyamide is not particularly limited, but a relative viscosity (η1.1) of 4.0 or more, preferably 4.5 to 6.0 is used. If the relative viscosity is less than 4.0, the viscosity of the resulting thermoplastic resin composition will be low, making it impossible to prevent drawdown.

(b) Polyolefins that can be used in the present invention include homopolymers of common olefins such as ethylene, propylene, butene-11hexene-1,4-methylpentene-1, and copolymers of ethylene and propylene or other toolefins. A combination of these α-olefins, a copolymer of two or more of these α-olefins, a homopolymer and a copolymer, or a blend of a homopolymer and a copolymer may be used. can.

Note that when polypropylene is used as the polyolefin, improvement in heat resistance is expected. Further, the use of high-density polyethylene is preferable from the viewpoint of drawdown resistance.

Among these polyolefins, polypropylene is
The melt flow rate at 230°C and a load of 2.16 kg is preferably 5 g/10 minutes or less, more preferably 0.
5 to Ig/10 minutes is used.

In addition, for polyethylene, the melt index (190℃
, 2.16 kg load) is preferably 1.0 g/10 minutes or less, more preferably 0. O1~0.5 g
/10 minutes. If the melt flow rate or melt index exceeds the above range, it becomes difficult to prevent drawdown.

Examples of the elastomer in the present invention include (1) an olefin elastomer and (2) an elastomer containing styrene.

(1) Olefin elastomer in the present invention is
Ethylene, propylene, 1-butene, 1-hexene, 4
- Means a copolymer rubber of two or more types of toolefins such as -methyl-pentene. Specifically, ethylene-
Examples include propylene copolymer rubber (EPR) and ethylene-butene copolymer rubber (EBR). Particularly preferred is ethylene-butene copolymer rubber (EBR). In addition, ethylene-propylene-diene copolymer rubber (EPDM)
can also be used.

The ethylene-propylene copolymer (EPR) rubber used in the present invention has a content of repeating units derived from ethylene of 10 to 90 mol%, and a content of repeating units derived from propylene of 90 to 10 mol%. It is preferable that A more preferable range is 20 to 80 mol% of ethylene repeating units and 80 to 20 mol% of propylene repeating units.

Also, the Mooney viscosity of EPR (1,1, (+00°
C) is preferably within the range of 1 to 120, more preferably 5 to +00.

In the present invention, ethylene-butene copolymer comb (,E
BR) is a random copolymer with a butene-1 content of 10 to 90% by weight, especially a butene-1 content of 20% by weight.
~80% by weight is preferred.

Mooney viscosity ML of the above ethylene-butene copolymer rubber,
, 4(toooC) is preferably in the range of 1 to 120, more preferably 5 to 100.

In addition, in the present invention, ethylene-propylene copolymer (
EPR) and ethylene-butene copolymer rubber (EBR)
basically consists of the above repeating units, or
Copolymers containing other resin components may also be used within a range that does not impair the properties of these copolymers.

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

Furthermore, the Mooney viscosity ML of EPDM. 4 (100°
C) is preferably in the range of 40-100, more preferably 60-80.

(2) As the styrene-containing elastomer, styrene-butadiene-styrene butt copolymer (
SBS), styrene-ethylene/butylene-styrene block copolymer (SEBS), and styrene-butadiene copolymer rubber (SBR).

In addition, styrene-ethylene/butylene-styrene block copolymer (SEBS) is a copolymer in which a styrene part and an ethylene/butylene copolymer part are in the form of a block, and it is expressed by the following - dilation (1). It is something that will be done.

(S-EB7S (wherein, S represents a polystyrene portion, EB represents an ethylene/butylene copolymer portion, and n represents the degree of polymerization.

Note that the styrene-ethylene/butylene-styrene block copolymer (SEBS) can generally be obtained by hydrogenating a styrene-butadiene-styrene block copolymer (5BS).

The modified elastomer (c) used in the present invention is an elastomer modified with an unsaturated carboxylic acid or its anhydride.

Examples of unsaturated carbonic acids or anhydrides include monocarboxylic acids such as acrylic acid and methacrylic acid, dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, maleic anhydride, itaconic anhydride, and endo-bicyclo(2, 2,1)
Examples include dicarboxylic anhydrides such as -5-heptene-2,3-dicarboxylic anhydride (himic anhydride), and dicarboxylic acids and their anhydrides are particularly preferred. Specifically, modification with maleic anhydride is preferred.

Further, as the elastomer modified with unsaturated carbonic acid or its anhydride, the above-mentioned (1) olefin elastomer and (2) styrene-containing elastomer are preferable.

The content of the unsaturated carboxylic acid or its anhydride in the modified elastomer is 0.05 to IO% by weight, preferably 0.1 to 5% by weight. If the amount of modification by the unsaturated carboxylic acid or its anhydride is less than the above lower limit, the modified elastomer and polyamide will not be sufficiently compatible. Moreover, if the upper limit is exceeded, it becomes difficult to uniformly disperse the modified elastomer in the polyamide.

The modified elastomer can be produced by either a solution method or a melt-kneading method. For example, in the case of melt kneading method,
Put the elastomer, unsaturated carboxylic acid (or acid anhydride) for modification, and catalyst (organic peroxide, etc.) into an extruder or twin-screw kneader, and heat it to a temperature of 130 to 300°C to melt it. Knead from In the case of a solution method, the starting material is dissolved in an organic solvent such as xylene, and the solution is stirred at a temperature of 100 to 300°C. In either case, ordinary radical polymerization catalysts can be used as catalysts, such as benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide, Peroxides such as peroxybenzoic acid, peroxyacetic acid, tert-butyl peroxypivalate, 2,5-dimethyl 2,5-di-tert-butyl peroxyhexine, diazo compounds such as azobisisobutyronitrile, etc. preferable. The amount of catalyst added is 1 part of unsaturated carboxylic acid for modification or its anhydride.
The amount is about 1 to 100 parts by weight per 00 parts by weight.

As the modified polyolefin (c), those obtained by modifying the polyolefin of component (b) with an unsaturated carboxylic acid or its anhydride can be used. As the unsaturated carboxylic acid anhydride, maleic anhydride is preferably used. In addition, the modification is performed when the content of maleic anhydride is 0.05 to 1
It is preferable to adjust the amount to 0% by weight.

The melt flow rate of the thermoplastic resin composition consisting of the above three components (al, (b), and (c) when it does not contain polyamide 66 is as follows: 270℃,
Under the condition of 2.16 kg load, 1.0 g / 10 minutes or less,
Preferably it is 0.5 g/'io min or less. When the melt flow rate exceeds 1.0 g 710 minutes, drawdown during blow molding cannot be reliably prevented, making it difficult to produce large blow molded products.

The blending ratio of the three components (a), (b) and (c) in the composition of the present invention is (a) + (bl + (c)
) is 100% by weight, (al polyamide or 60~9
0% by weight, preferably 70-80% by weight, (b) 1-35% by weight of polyolefin and/or elastomer, preferably 5-20% by weight, (c) 1-35% by weight of modified elastomer and/or modified polyolefin. %, preferably 5 to 20% by weight.

(a) If the polyamide content is less than 60% by weight, the surface condition of the resulting molded product will not be good and the rigidity will be insufficient. Moreover, if the amount exceeds 90% by weight, impact resistance will decrease and water absorption will also increase.

(If the content of bl polyolefin and/or elastomer is less than 1% by weight, moldability will be poor.

In addition, if the amount exceeds 35% by weight, the compatibility with polyamide will decrease, the polyolefin and/or elastomer will not be able to be uniformly dispersed in the matrix formed by polyamide, and the mechanical strength etc. of the resulting molded product will decrease. do.

(If the amount of the c1 modified elastomer and/or modified polyolefin is less than 1% by weight, the impact resistance will decrease. Also,
If the amount exceeds 35% by weight, the rigidity of the molded article will be lost.

The resin composition of the present invention may also contain other additives for the purpose of modification, such as heat stabilizers, light stabilizers, flame retardants, plasticizers, antistatic agents, mold release agents, blowing agents, and nucleating agents. etc. can be added.

The thermoplastic resin composition of the present invention can be produced by mixing the above-mentioned components and dynamically heat-treating, that is, melt-kneading. As the mixing device, conventionally known devices such as an open type mixing roll, a non-open type Banbury mixer 1 extruder (including twin screws), and a kneader 1 continuous mixer can be used. Kneading at 200-300°C
The temperature may be 230 to 270°C, preferably 230 to 270°C.

[For production]

The thermoplastic resin composition of the present invention contains a polyamide having a specific relative viscosity, a polyolefin and/or elastomer, and a modified elastomer and/or modified polyolefin in the above-mentioned compounding ratio, High viscosity can be expected due to the reaction between the two, and the composition as a whole has a melt flow rate below a certain value, reliably preventing drawdown during molding such as blow molding. Therefore, moldability is not deteriorated.

Further, the composition of the present invention has excellent physical properties without impairing the good surface condition, chemical resistance, impact resistance, etc. of the polyamide itself. The reason for this is not necessarily clear, but in the composition of the present invention, a certain amount (60% by weight) or more of polyamide or so-called polymer alloy matrix resin is formed, and this matrix resin is surrounded by a modified elastomer or modified polyolefin. This is thought to be due to the fact that the polyolefin fins or elastomer particles are uniformly dispersed.

〔Example〕

The present invention will be explained in more detail by the following specific examples.

In each of the Examples and Comparative Examples, the following resins were used as raw material resins.

[1] Polyamide ■PAI: Boryamide 6 [Relative viscosity 5.0, EMS F50] ■PA2: Boryamide 6 [Relative viscosity 4.0, EMS F50]
47] ■PA3: Boryamide 6 [relative viscosity 2.8, EMSIA
, 28) ■PA4: Polyamide 66 [relative viscosity 5.8, manufactured by Unitika ■A153] ■PA6 Nylon 6/66 (relative viscosity 4.3, east side ■
CM 6041
load) 0.4 g/10 minutes, ethylene content 5.8% by weight,) ■PE/high-density polyethylene [melt index (M
l, 190℃, 2.16kg? ri weight) O, 1g/
10 minutes, density 0.950 g/cm '3) [3] Elastomer ■ EBR: Ethylene-butene copolymer rubber [Muni viscosity M L 1.4 (100°C) or 15-20.1-butene content 20% by weight , density 0.88g/cd1■EPR
: Ethylene-propylene copolymer rubber [Mooney viscosity M
L 1.4 (100°C) is 70, propylene content 28% by weight, density 0.86 g/cnf] [4] Modified elastomer ■ CMEBR: The above ethylene-butene copolymer rubber modified with maleic anhydride. Maleic anhydride content 0
．． 8% by weight.

[51 Modified Polyolefin ■ CMPP: Modified ethylene-propylene random copolymer [Ethylene content 3.0% by weight, melt flow rate (MFR, 230°C, 2.16 kg load) Ig/10
(2) modified with maleic anhydride, with a maleic anhydride content of 0.3% by weight.

■CMP E modified polyethylene, the above-mentioned high-density polyethylene modified with maleic anhydride, maleic anhydride content 0.3% by weight Examples 1 to 10 and Comparative Examples 1 to
5 Polyamide, polypropylene, high-density polyethylene, modified elastomer, modified polypropylene, modified polyethylene, and elastomer were mixed in a two-axis direction mixer (45 mmφ, L/D 28) at the compounding ratio shown in Table 1.
So, 230~270°CC120Orp, discharge amount 40k
The mixture was melt-kneaded at a rate of g/hr to form pellets.

For these compositions, the melt flow rate (240
℃, 2.16 kg load), flexural modulus, and Izot impact strength were measured.

Next, the moldability of the obtained composition (pellet) was evaluated based on the following criteria.

In addition, the surface properties of molded articles obtained from the compositions were evaluated using the following criteria.

(1) Melt flow rate: Measured at 240°C and a load of 2.16 kg.

(2) Flexural modulus: JIS K7203 i: Twisted measurement.

(3) Izot impact strength: Measured according to JIS K7110.

(4) Molding The two-set acid compound (pellet) was molded into a cylindrical parison with a length of 1.5 m at a molding temperature of 230 to 270°C using a large blow molding machine (manufactured by Ishikawajima Harima Heavy Industries ■, IPB200C). Manufactured. An attempt was made to manufacture a 1 m long spoiler from this parison. In this molding, a material that could be sufficiently molded without substantially causing drawdown was designated as Q. In addition, those in which drawdown occurred and molding became impossible were marked as x.

(5) A cylindrical parison with a length of 1.5 m was produced using the above-mentioned large-scale blow molding machine using the surface property double-set acid (pellet). A boiler with a length of 1 m was manufactured from this parison by blow molding. The average surface roughness of the obtained spoiler was measured in accordance with JIS B 0651. Those with an average surface roughness of 8 μm or less were rated as ○.

The results are shown in Table 1.

For comparison, compositions having the formulations shown in Table 1 were also produced, and various tests were conducted on the compositions in the same manner as in Example 1.

Furthermore, moldability was evaluated in the same manner as in Example 1 using this composition.

Furthermore, the surface properties of the blow-molded spoiler were evaluated in the same manner as in Example 1.

The results are also shown in Table 1.

As is clear from Table 1, the thermoplastic resin composition of the present invention had a low melt flow rate, and was good in all of the flexural modulus, Izot impact strength, moldability, and surface properties of blow-molded products.

〔Effect of the invention〕

As detailed above, the thermoplastic resin composition of the present invention has a low melt flow rate and prevents drawdown, and therefore has good moldability.

It also has excellent surface properties, impact resistance, and mechanical strength.

Therefore, the thermoplastic resin composition of the present invention is suitable for automobile parts, such as spoilers, bumpers, duct parts, gasoline tank peripheral parts, various blow molded products such as containers, and structural parts such as OA equipment. .

Applicant: Tonen Petrochemical Co., Ltd.

Claims (2)

[Claims] (1) (a) 60 to 90% by weight of polyamide having a relative viscosity (η_r_■_i) of 4.0 or more; (b) polyolefin and/or elastomer 1 to 35%;
and (c) 1 to 35% by weight of a modified elastomer and/or modified polyolefin obtained by reacting an elastomer and/or polyolefin with an unsaturated carboxylic acid or its anhydride, and the melt flow of the entire composition is Rate (240℃,
1. A thermoplastic resin composition characterized in that the 2.16 kg load (270° C., 2.16 kg load for polyamide 66-containing compositions) is 1.0 g/10 minutes or less. (2) In the thermoplastic resin composition according to claim 1,
The elastomer is a copolymer rubber selected from ethylene-propylene copolymer rubber, ethylene-butylene copolymer rubber, ethylene-propylene-diene copolymer rubber, and styrene-containing copolymer rubber. A thermoplastic resin composition.