JPH064760B2 - Polyamide-containing impact-resistant resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyamide-containing resin composition having impact resistance as well as excellent properties of polyamide resin such as toughness, rigidity and abrasion resistance. It is used in a wide range of fields including industrial materials such as automobiles, electricity, electronics, and machines.

[Prior Art] Since polyamide resins are inferior in impact resistance, various improvements have been proposed.

Japanese Patent Laid-Open No. 52-150457 discloses a hydrogenated block copolymer 100.
A composition is disclosed comprising 1 part by weight and 5 to 200 parts by weight polyamide. However, since such a block copolymer has extremely poor compatibility with a polar polymer such as polyamide, it cannot be made into a useful composition.

JP-A-59-56451 describes (a) polyamide 50 to 90% by weight (b)
Maleic anhydride adducts of hydrogenated polymers of conjugated dienes or hydrogenated copolymers of conjugated dienes and vinyl aromatic hydrocarbons 10
Impact polymer composition in the form of a graft copolymer containing from 50 to 50% by weight, an unsaturated content of (b) of 0.5 to 20%, at least 5% of (a) and (b) containing at least 20% of polyamide. The thing is disclosed. However, when a maleic anhydride adduct of a hydrogenated polymer of a conjugated diene or a hydrogenated polymer of a conjugated diene and a vinyl aromatic hydrocarbon is mixed with a polyamide, there is a drawback that rigidity is obviously lowered due to the increase of the mixing ratio. .

Japanese Examined Patent Publication No. 55-44108 discloses one phase containing 60 to 99% by weight of a polyamide having a number average molecular weight of at least 5000, and
From 1 to 40% by weight of at least one other phase having a particle size in the range of 0.01 to 1.0 micron and containing at least one polymerizing pair adhering to the polyamide, essentially a multiphase thermoplastic composition Is disclosed. The polymer of at least one other phase has a tensile modulus in the range of 0.0705 to 1410 kg / cm ² , (tensile modulus of the polyamide matrix resin) / (tensile modulus of the at least one polymer) The ratio is greater than 10/1, and the at least 1
A polymer of at least 20 of the at least one other phase.
Polymers or polymer mixtures which make up weight% and can be used as polymers for at least one other phase are described in a very wide range. However, this Japanese Patent Publication Sho 55-441
No. 08 contains 0.07 as a polymer of at least one other phase.
Since the one having a low tensile modulus of 05 to 1410 kg / cm ^{2 and} a tensile modulus lower than 1/10 of the tensile modulus of the polyamide matrix resin is used, there is a drawback that the rigidity is obviously lowered.

Further, the decrease in rigidity will be specifically described with reference to the drawings.

FIG. 1 shows the relationship between the bending elastic modulus and the polyamide mixing ratio of the resin composition as an index of rigidity. Diagram A shows the relationship between the flexural modulus and the polyamide mixing ratio of the compositions disclosed in JP-A-59-56451 and JP-B-55-44108.

It is clearly understood that the bending elastic modulus sharply decreases due to the decrease in the polyamide mixing ratio, in other words, the increase in the mixing ratio of the polymer mixed with the polyamide. This is
It will also be limited to regions where the polyamide mixing ratio is high. On the other hand, diagrams B, B ₂ and B ₃ show the relationship between the two in the composition of the present invention. Even if the mixing ratio of the polyamide is decreased, that is, even if the mixing ratio of the copolymer and the maleic anhydride-modified polyphenylene ether resin mixed with the polyamide is increased, the flexural modulus is maintained at a high level. This also has the advantage that the polyamide mixing ratio can be selected in a wide range and, for example, other peculiarities of the polyamide (such as hygroscopicity and performance deterioration due to moisture absorption) can be improved by decreasing the polyamide mixing ratio. .

[Problems to be Solved by the Invention] In recent years, demands for improvement in impact resistance of polyamide resins have been further increased with the expansion of their applications. Impact resistance is
It is usually expressed by Izod impact strength, and in the case of polyamide resin alone, several kg ・ cm / cm to 10 kg ・ cm / cm (with notch,
It is about dry condition.

The present invention improves impact resistance of polyamide resin. Polyamide resin has extremely poor compatibility with styrene-based hydrocarbon polymer block-conjugated diene-based elastomer block copolymer and styrene-based hydrocarbon polymer block-olefin-based elastomer block copolymer. It cannot be improved impact. As a result of extensive studies on this point,
One or more copolymers selected from the group consisting of polyamide resin and styrene hydrocarbon polymer block-conjugated diene elastomer block copolymer and styrene hydrocarbon polymer block-olefin elastomer block copolymer. It has been found that excellent impact resistance can be obtained by using a composition comprising a maleic anhydride-modified polyphenylene ether resin in addition.

[Means and Actions for Solving Problems] The present invention provides (A) styrene-based hydrocarbon polymer block
10% by weight or more and 35% by weight or less of one or more copolymers selected from the group consisting of a conjugated diene elastomer block copolymer and a styrene hydrocarbon polymer block-olefin elastomer block copolymer,
An impact-resistant resin composition comprising (B) a maleic anhydride-modified polyphenylene ether resin in an amount of 2% by weight or more and the same as (A), and 30% by weight to 88% by weight of a (c) polyamide resin.

The styrene-based hydrocarbon polymer block-conjugated diene-based elastomer block copolymer used in the present invention is a styrene-based hydrocarbon block (X) and (X ′) and a conjugated diene block (Y) (where X and X ′ are The same or different) elastomer block copolymer n is an integer of 1 to 10. ) Linear block copolymer represented by (In the formula, m is an integer of 1 to 4, and Z represents a residue of a coupling agent such as silicon tetrachloride or tin tetrachloride or a residue of an initiator such as a polyfunctional organic lithium compound.) A radial block copolymer represented by

Representative compounds as styrene-based hydrocarbons used here include styrene, α-methylstyrene, vinylxylene, ethylvinylxylene, vinylnaphthalene and mixtures thereof, and the conjugated diene includes butadiene, isoprene, and 1,3-pentadiene or 2,3-dimethylbutadiene, and mixtures thereof.

The terminal blocks of these block copolymers may be the same or different.

The number average molecular weight of these block copolymers is 10,000-80
It is 0,000, preferably 20,000 to 500,000.

The content of styrenic hydrocarbon in the block copolymer is preferably 10 to 70% by weight, more preferably 15 to 55% by weight.

The styrene-based hydrocarbon polymer block-olefin-based elastomer block copolymer used in the present invention comprises selectively hydrogenating the conjugated diene portion of the styrene-based hydrocarbon polymer block-conjugated diene-based elastomer block copolymer. Is obtained by. The unsaturated bond content in the hydrogenated copolymer is reduced to 20% or less of the original value. The preferred unsaturated bond content for differential use is 10% or less of the original content, and more preferably 5% or less.

Next, the maleic anhydride-modified polyphenylene ether resin used in the present invention is polyphenylene ether resin 100.
In the coexistence of 0.1 to 5 parts by weight, preferably 0.1 to 3 parts by weight, of the radical generator with respect to parts by weight, 200 to 350 ° C., preferably
0.3-10 parts by weight in the temperature range of 220-300 ° C, preferably 0.5
~ 7 parts by weight of maleic anhydride is reacted.
As the polyphenylene ether resin, a general formula (However, R ₁ and R ₂ represent the same or different hydrogen atoms, halogen atoms or substituents such as alkyl groups and aryl groups having 1 to 4 carbon atoms, and n represents an integer representing the degree of polymerization.)
And a modified polyphenylene ether obtained by graft-copolymerizing this with a vinyl compound. Specific examples of the polyphenylene ether include poly (2,6-dimethylphenylene-1,4-ether), poly (2-methyl-6-ethylphenylene-1,
4-ether), poly (2,6-diethylphenylene-1,4
-Ether), poly (2-methyl-6-n-propylphenylene-1,4-ether), poly (2-methyl-6-
Chlorphenylene-1,4-ether), poly (2-ethyl-6-chlorophenylene-1,4-ether) and the like. The average degree of polymerization n is preferably in the range of 60 to 250. Vinyl compounds include styrene, methylstyrene,
Styrene derivatives such as dimethyl styrene, α-methyl styrene and t-butyl butylene are used.

The radical generator used in the present invention represents known organic peroxides and diazo compounds, and specific examples thereof include benzoyl peroxide, dicumyl peroxide and t-.
Butyl hydroperoxide, cumene hydroperoxide, azobisisobutyronitrile and the like can be mentioned. These radical generators can be used in combination of two or more.

The reaction of maleic anhydride is carried out by methods well known to those skilled in the art. For example, disclosed in JP-A-52-142799,
A method of melt-kneading a polyphenylene resin and maleic anhydride in the coexistence of a radical generator, substantially without solvent, at a temperature of 200 to 300 ° C. and a shear rate of 10 sec ⁻¹ or more, and JP The method disclosed in JP-A-59-59724 may be a method of bringing the respective components into contact with each other while melt-kneading. The present invention is not limited by the method for producing the maleic anhydride-modified polyphenylene ether.

The polyamide resin used in the present invention is a polycondensate of dicarboxylic acid and diamine, a polycondensate of α-aminocarboxylic acid,
It is a ring-opening polymer of a cyclic lactam, and specifically, nylon 6, nylon 64, nylon 46, nylon 66, nylon 610, nylon 11, nylon 12, etc., and their copolymers, namely nylon 6-nylon 66. Examples thereof include copolymers, nylon 6-nylon 12 copolymers, and mixtures thereof. The number average molecular weight of these polyamides is generally 5,000 to 30,000, and preferably 10,000 to 25,000.

In the resin composition of the present invention, (A) styrene-based hydrocarbon polymer block-conjugated diene-based elastomer block copolymer and styrene-based hydrocarbon polymer block-
The content of one or more copolymers selected from the group consisting of olefin-based elastomer block copolymers is 10
~ 35 wt%, preferably 15-30 wt%. 10% by weight
If the amount is less than 35% by weight, the impact resistance is insufficiently improved. If the amount exceeds 35% by weight, the rigidity, toughness, abrasion resistance, etc. originally possessed by the polyamide resin are mainly attributable to the insufficient amount ratio of the polyamide resin. The characteristics are impaired.

The maleic anhydride modified polyphenylene ether resin is 2
The content is not less than the same weight% as (A) and preferably not more than 4% by weight and not more than 0.8 times as much as (A). If it is less than 2% by weight, the impact resistance is not sufficiently improved, and if it exceeds the content of (A), the impact resistance is remarkably lowered.

As described above, the inventors of the present invention say that impact resistance is remarkably improved particularly by the maleic anhydride-modified polyphenylene ether-based resin, and further by the content of the maleic anhydride-modified polyphenylene ether-based resin in a specific range. This is the first time that a surprising fact was found and the present invention was achieved. Such a solution has never been disclosed by the person skilled in the art by analogy or suggestion with the prior art.

The content of the polyamide resin is 88 to the remaining (A) and the maleic anhydride-modified polyphenylene ether-based resin is excluded.
30% by weight.

The improved impact resistant resin composition of the present invention can be manufactured by various methods. For example, a method of pre-kneading any two or three components and kneading the remaining components, or simultaneously kneading three or four components is included. In addition, additives, reinforcing agents, fillers and the like can be added at any of these stages, if necessary, to the extent that the properties of the composition are not impaired. Examples of the kneading device include an extruder, a mixing roll, a Banbury mixer, a kneader, and the like, and the kneading method using a twin-screw extruder is particularly preferable in the present invention. Although the kneading temperature depends on the melting temperature of the component resins, it is usually 220 to 300 ° C. in the kneading not containing the polyamide resin, and preferably the melting point of the polyamide resin or more and the melting point + 50 ° C. or less in the kneading containing the polyamide resin.

[Effect of the Invention] The composition of the present invention has improved rigidity in combination with improved impact resistance, and has the toughness of a polyamide resin.
Balanced with excellent properties such as wear resistance,
It is molded into various shapes by various conventionally known methods. For example, methods such as injection molding, extrusion molding, compression molding, foam molding and the like can be mentioned, and they are used in a wide range of applications including industrial materials such as automobiles, electricity, electronics and machinery.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

Examples 1 to 15 First, a maleic anhydride-modified polyphenylene ether resin was prepared as follows.

Poly (2,6-dimethylphenylene-1,4) with an average degree of polymerization of 140
-Ether), di-t-butyl peroxide and maleic anhydride were dry-blended at a weight ratio of 100/1/5 at room temperature, and then a screw diameter of 30 mm, L / D = 30 Using a twin-screw extruder with a vent, melt at a cylinder temperature of 300 ° C and a screw rotation speed of 75 rpm,
It was extruded with a residence time of 1 minute, passed through a cooling bath, and then pelletized. 0.05 g of this pellet was sampled and made into a film having a thickness of about 15 microns using chloroform, and then heated and refluxed with ethanol in a Soxhlet extractor for 10 hours. Next, this film was dried and used as a sample for infrared spectroscopy measurement. Derived from reaction with maleic anhydride in this sample-C
The presence of O ₂ -structure in the infrared absorption spectrum 1000-1800 cm ^-1
It was confirmed by analyzing the absorption peak of.

Next, styrene-butadiene-styrene-butadiene block polymer (styrene content 40% by weight), styrene-ethylene / butylene-styrene block copolymer (styrene content 29% by weight), the maleic anhydride-modified polyphenylene ether resin and nylon. 66 (number average molecular weight 18000) was mixed at the ratio shown in Table 1, extruded by a twin-screw extruder (screw diameter 45 mm, L / D = 33) set at 280 ° C., and pelletized through a cooling bath. 80 these pellets
After vacuum-drying at 8 ° C. for 8 hours, injection molding was performed under the following conditions to prepare a molded piece for measuring physical properties.

Injection molding machine 1 ounce Cylinder temperature 280 ° C Injection pressure 600kg / cm ² Injection time 15 seconds Cooling time 20 seconds Mold temperature 80 seconds Subsequently, the physical properties were measured by the following methods.

Izod impact strength: Measured by ASTM D-256 using a notched test piece having a thickness of 1/8 ".

Rigidity: 1/8 "thick test piece, ASTM D
The flexural modulus was measured according to 790-80.

High temperature rigidity: 1/8 "thickness of test piece, A in dry condition
The heat distortion temperature at 18.6 kg / cm ² was measured by STMD648.

The results are shown in Table 1.

Comparative Example 1 Table 1 shows the physical properties of the nylon 66 resin alone used in the examples.

Comparative Examples 2, 4, 6, 8 The same procedure as in Examples 1 to 15 was carried out except that the maleic anhydride-modified polyphenylene ether resin was not added. The results are shown in Table 1.

Comparative Examples 3, 5, 9 Maleic anhydride modified polyphenylene ether resin
The same procedure as in Examples 1 to 15 was performed, except that the content of the styrene-based hydrocarbon polymer block / olefin-based elastomer block copolymer was exceeded. The results are shown in Table 1.
It was shown to.

Comparative Example 7 The procedure of Examples 1 to 15 was repeated, except that the styrene-based hydrocarbon polymer block-olefin-based elastomer block copolymer was kneaded at a ratio of less than 10% by weight. The results are shown in Table 1.
It was shown to.

Comparative Example 10 The procedure of Examples 1 to 15 was repeated, except that the styrene-based hydrocarbon polymer block-olefin-based elastomer block copolymer was kneaded in a proportion of more than 35% by weight. The results are shown in Table 1.

The autoclave of Example 100 was charged with an aqueous solution 20 containing 9.4 kg of diaminobutane and 14.6 kg of adipic acid, and the temperature was gradually raised with stirring and the temperature was raised to 140 ° C. in 2 hours. Since almost all the water is removed, a vacuum of 50 to 100 mmHg
The temperature was raised to 220 ° C and the condensation reaction was continued for 3 hours. Here, once cooled, the contents were crushed and taken out, charged into a 200 kettle, and continuously heated at 260 ° C. for 4 hours while flowing N ₂ gas at a rate of 10 / min. The produced nylon 46, polytetramethylene adipamide) is (96% H ₂ SO ₄ , 0.1% by weight) in sulfuric acid.
Ηr = 3.4 measured at 20 ° C.).

Using this nylon 46 as polyamide, extrusion temperature,
The same procedure as in Examples 1 to 15 was performed except that the injection molding temperature was 310 ° C.

The results are as follows, and high impact resistance and rigidity were obtained. Incidentally, the physical properties of the nylon 46 resin alone are also shown.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the relationship between the flexural modulus and the polyamide mixing ratio of a resin composition as an index of rigidity. Diagram A shows the relationship between the flexural modulus and the polyamide mixing ratio of the compositions disclosed in JP-A-59-56451 and JP-B-55-44108. Diagram B shows the relationship between the two of the compositions of the present invention.

Claims (1)

[Claims] 1. A copolymer selected from the group consisting of (A) styrene-based hydrocarbon polymer block-conjugated diene-based elastomer block copolymer and styrene-based hydrocarbon polymer block-olefin-based elastomer block copolymer. Or 2 kinds or more, 10 weight% or more and 35 weight% or less,
An impact-resistant resin composition containing (B) a maleic anhydride-modified polyphenylene ether resin in an amount of 2% by weight or more and the same as (A) or less by weight, and (C) a polyamide resin in an amount of 30% by weight or more and 88% by weight or less.