JPH0657787B2 - Impact resistant polyamide composition - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to high impact polyamide compositions. More specifically, the present invention relates to a polyamide composition which is suitable as a material for automobile parts, sports equipment and the like, and which has excellent mechanical properties and thermal properties as well as excellent impact resistance.

2. Description of the Related Art Conventionally, as a polyamide composition having improved impact resistance, for example, a polyamide compounded with an ethylene ionomer resin (US Pat. No. 3,845,163, JP-B-5)
4-4743), a polyamide compounded with an ionomer or other elastomer having a low tensile elastic modulus having a bonding site (specific polar group) with an polyamide so as to have a dispersed particle size of 1 μm or less (Japanese Patent Publication 55-55). −44108),
Polyamide blended with ionomer resin and carbonate compound or oxide compound (Japanese Patent Publication No.
JP), a mixture of a polyamide with an ionomer and an olefin copolymerization elastomer (JP-A-58-23850).
No. gazette) is proposed.

However, in these impact-resistant polyamide compositions, although the non-weld portion of the molded article shows a high impact strength to some extent, the weld portion has a variation in the Izod impact strength value, and its average value is low. Atsuta By the way, in the case of forming a molded product, most of the molded products have one or several welds unless they have a very simple shape. Therefore, the low impact strength of the weld portion is an important problem for practical use.

Problems to be Solved by the Invention The object of the present invention is to overcome the drawbacks of conventional impact-resistant polyamide compositions, and to reduce the variation in the Izod impact strength value not only in the non-weld portion but also in the weld portion, and It is to provide a polyamide composition having excellent impact resistance such as high average value.

Means for Solving the Problems As a result of intensive studies by the present inventors, a resin mixture of a polyamide having a specific average sulfuric acid viscosity and an ethylene ionomer resin alone or an ethylene ionomer resin, or an olefin resin A composition obtained by adding a copolymerized elastomer or a styrene-based copolymerized elastomer to a specific carbonate compound, an oxide compound and, if necessary, a polyhydric alcohol in predetermined proportions may be suitable for the above purpose. The inventors have found the present invention and completed the present invention based on this finding.

That is, the present invention provides (A) an average sulfuric acid viscosity of 3.3 to 3.8.
Polyamide 60 having an average sulfuric acid viscosity of 3.15 to 3.80, which is a mixture of the above-mentioned polyamide and a polyamide having an average sulfuric acid viscosity of 2.5 to 3.0 and the former content is 70% by weight or less.
To 95% by weight, (B) an ethylene ionomer 40, a part of which may be substituted with a predetermined proportion of an olefin copolymer elastomer or a styrene copolymer elastomer
(C) General formula per 100 parts by weight of the resin mixture consisting of 5% by weight (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each a hydrogen atom or an alkyl group, and X is At least one selected from a carbonate compound and an oxide compound represented by the formula: 0.05 to 5.0 parts by weight, and optionally (D) a polyvalent compound having 2 to 20 carbon atoms per 1 part by weight of the component (C). The present invention provides an impact-resistant polyamide composition containing 0.1 to 1 part by weight of alcohol.

In the composition of the present invention, the polyamide used as the component (A) is a linear polymer compound having an amide bond, and examples thereof include nylon 66, nylon 6, nylon 610, nylon 612, nylon 46 and the like. Homopolymers, copolymers such as nylon 66-6, nylon 66-610 and nylon 66 and 6, nylon 66 and
Polymer blends such as 610 are included. Among them, nylon 66 homopolymer, copolymer containing nylon 66 as a main component, polymer blends of these and polymer blends of these with other nylons are excellent in heat resistance and mechanical properties, It is particularly suitable.

In the present invention, these polyamides include polyamides having an average sulfuric acid viscosity of 3.3 to 3.8 and average sulfuric acid viscosities of 2.5 to 2.5.
A mixture with 3.0 polyamide, the former content of 70
% By weight and an average sulfuric acid viscosity of 3.15 to 3.
It must be 80.

Here, the sulfuric acid viscosity is the solution viscosity of polyamide measured using 98% sulfuric acid according to the method specified in JIS K6810. Such a polyamide blend composition of the present invention is advantageous because it has a high Izod impact strength in the weld portion and an excellent molding fluidity. The content of polyamide having a sulfuric acid viscosity of 3.3 to 3.8 is 7
If it exceeds 0% by weight, the molding fluidity is lowered and the moldability is deteriorated.

The ethylene-based ionomer resin used as the component (B) in the composition of the present invention is an ethylene unit, an unsaturated carboxylic acid ester unit, a copolymer composed of an unsaturated carboxylic acid unit and an unsaturated carboxylic acid metal salt unit. The proportion of ethylene units in the composition is 90 to 98 mol%.

The unsaturated carboxylic acid ester unit is a unit derived from an unsaturated carboxylic acid having 3 to 8 carbon atoms, for example, an alkyl ester of an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, and ethacrylic acid. Examples of such alkyl esters of unsaturated carboxylic acids include methyl acrylate, ethyl acrylate, n-butyl acrylate, t-acrylic acid.
-Butyl, isobutyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate,
Isopropyl methacrylate, n-butyl methacrylate,
Examples thereof include t-butyl methacrylate and isobutyl methacrylate, and of these, methyl acrylate, ethyl acrylate, methyl methacrylate and n-butyl methacrylate are particularly preferable.

Further, the unsaturated carboxylic acid unit is a unit derived from the unsaturated carboxylic acid mentioned above in the unsaturated carboxylic acid ester unit, the unsaturated carboxylic acid metal salt unit is derived from the metal salt of the unsaturated carboxylic acid It is a unit to do. As the metal species constituting the latter, there are IA group, IB group and II of the periodic table.
Group A, IIB, IIIA and VIII Group 4 metals,
For example, Na, K, Cu, Mg, Ca, Ba, Zn, Cd, Al, Fe, Co,
Examples include Ni. Among these, especially Na, K, Mg, Ca,
Ba and Zn are preferred.

Between the unsaturated carboxylic acid ester unit, the unsaturated carboxylic acid unit and the unsaturated carboxylic acid metal salt unit in the ethylene-based ionomer resin, when the respective molar numbers are α, β and γ, as well as Those having the relationship of are preferable.

If the proportion of ethylene units in the ethylene-based ionomer resin is less than 90 mol%, it is difficult to produce an ethylene-based copolymer by the high-pressure polyethylene method, so that it is not practical, and this proportion is 98 mol%. If it exceeds, the impact resistance is insufficiently improved.

On the other hand, when nylon 66 is used as the component (A), a larger amount of unsaturated carboxylic acid ester units gives better results in improving impact resistance, but if this amount is too large, , Ie If the value of is larger than 0.6, physical properties such as tensile strength are deteriorated, which is not preferable. For unsaturated carboxylic acid metal salt units, if this amount is too small, that is, If the value of is less than 0.1, the fluidity during melting is reduced, and if this amount is too large, i.e. If the value of is larger than 0.9, the impact resistance becomes insufficient, so that both are unsuitable. The unsaturated carboxylic acid unit is
It is necessary to increase the affinity between the ethylene ionomer resin and the polyamide.

In the composition of the present invention, as the component (B), a mixture of the ethylene-based ionomer resin and, if necessary, an olefin-based copolymer elastomer or a styrene-based copolymer elastomer can be used.

The olefin-based copolymer elastomer is an elastomer composed of a copolymer of ethylene and α-olefin having 3 or more carbon atoms, and examples thereof include ethylene and propylene, butene-1, hexene-1, 4-. Examples thereof include copolymers with methylbutene-1, 4-methylpentene-1 and the like. Among these, particularly preferable are copolymers of ethylene and propylene, and copolymers of ethylene and butene-1. In addition to ethylene and α-olefin having 3 or more carbon atoms, this ethylene-based copolymer elastomer further contains a non-conjugated diene such as methylene norbornene, ethylidene norbornene, 1,4-hexadiene and dicyclopentadiene. It may be a terpolymer.

The proportion of each component of the copolymer is not particularly limited, but the lower the glass transition temperature of the copolymer and the lower the crystallinity, the more the impact resistance of the polyamide composition at low temperature is improved. Considering this, the number of carbon atoms in the copolymer is 3
The above α-olefin content is preferably in the range of 10 to 40 mol%, particularly 15 to 35 mol%.

On the other hand, examples of the styrene-based copolymer elastomer include styrene-butadiene rubber and hydride of styrene-butadiene block polymer.

The impact strength at low temperature is improved by adding these copolymer elastomers. Regarding the amount of addition, the weight ratio of the ethylene ionomer resin to the copolymer elastomer is 3: 7 to 9.5: 0.5. Mixed to be in range. If the amount of the copolymerized elastomer is too small with respect to the ethylene ionomer resin, the compounding effect cannot be obtained, and if it is too large, the properties preferably based on the ionomer, such as impact strength, decrease.

Regarding the ratio of the component (A) and the component (B) in the composition of the present invention, the component (A) is 60 to 95% by weight and the component (B) is 5 to 40%.
It is selected in the range of weight%.

In the composition of the present invention, as the component (C), a compound represented by the general formula (R ₁ , R ₂ , R ₃ , R ₄ and X in the formula have the same meanings as described above), and at least one selected from the carbonate compound and the oxide compound is used.

Examples of the carbonate compound include ethylene carbonate, propylene carbonate and butylene carbonate, and examples of the oxide compound include ethylene oxide, propylene oxide and butylene oxide. These compounds may be used alone or in combination of two or more, and the amount thereof is 0.05 to 100 parts by weight of the total amount of the components (A) and (B).
It is selected in the range of 5.0 parts by weight, preferably 0.5 to 3.0 parts by weight.

It is considered that the carbonate compound and the oxide compound are present between the polyamide and the ethylene-based ionomer resin to chemically bond the two in some form, and also between the polyamides and the ethylene-based ionomer resin. It is conceivable that some of them are crosslinked.
By these, by preventing the change of the dispersed particle size and shape of the ionomer resin, or by suppressing the variation of the dispersed concentration in the polyamide matrix, it is believed that the Izod impact strength of the weld part is particularly improved. .

With respect to the total 100 parts by weight of the component (A) and the component (B), the above effect is not observed at less than 0.05 parts by weight, while if it exceeds 5.0 parts by weight, the gel during melt kneading The deterioration of the product is extremely difficult to produce, and it remains unreacted in the final composition, and silver streaks (silver) are generated on the surface of the injection molded product to reduce the commercial value. It causes a decrease in Izod impact strength.

In the composition of the present invention, when a polyhydric alcohol having 2 to 20 carbon atoms is used as the component (D) together with the component (C),
The effect can be further enhanced. The polyhydric alcohol serves as a dispersion medium for dispersing the carbonate compound or the oxide compound in the polymer.

As the polyhydric alcohol, for example, glycerin, ethylene glycol, pentaerythritol and the like are preferably mentioned, and the compounding amount thereof is selected in the range of 0.1 to 1 part by weight per 1 part by weight of the component (C). If this amount is less than 0.1 part by weight, the effect of addition will not be sufficiently exerted, and if it exceeds 1 part by weight,
It is not economical because it is not effective for that amount.

The composition of the present invention can be obtained by simultaneously melt-kneading the component (A), the component (B), the component (C) and, if necessary, the component (D). (A) component and (C) component are melt-kneaded in advance,
Even if the component (B) is melt-kneaded, the impact strength of the weld portion is not improved. From these facts, it is clear that the carbonate compound and the oxide compound are involved between the polyamide and the ethylene ionomer.

Further, when using an olefin copolymer elastomer or a styrene copolymer elastomer together with an ethylene ionomer resin as the component (B), the copolymer elastomer is (A) component, (C) component and an ethylene ionomer resin. It may be melt-kneaded, or may be melt-kneaded with the ethylene-based ionomer resin in advance and then melt-kneaded with the components (A) and (C).

One example of the preferred method for producing the composition of the present invention will be described. A polyamide pellet, an ethylene ionomer resin pellet, an olefin copolymer elastomer pellet or a styrene copolymer elastomer pellet, a carbonate compound, an oxide compound, and a polyhydric compound. The alcohol is blended in a tumbler or a Henschel mixer and melted and kneaded in an extruder. Of course, it is also possible to use a method in which only the polyamide pellets are supplied from the hopper and the other polymer pellets or compounds are side fed from the vent port. An extruder having a high kneading property, such as a twin-screw extruder, is preferably used.

In the composition of the present invention, additives usually used in polyamide compositions, for example, stearic acid metal salt, ethylenebisstearylamide, lubricants such as waxes, copper compounds,
Metal halides, heat-resistant agents such as organic heat stabilizers, manganese compounds, weathering agents such as carbon black, reinforcing agents such as glass fiber, talc, kaolin, mica, wollastonite, carbon fiber, pigments and dyes A colorant or the like can be added if necessary. Further, a heat stabilizer, weather resistance and the like for the ethylene ionomer resin, olefin copolymer elastomer or styrene copolymer elastomer may be appropriately added.

Effects of the Invention The impact-resistant polyamide composition of the present invention has excellent impact resistance, such as a small variation in the Izod impact strength value not only in the non-welded portion but also in the welded portion and having a high average value. It has excellent molding fluidity, and is suitable as a material for fields requiring high impact resistance and good moldability, for example, automobile parts and sports equipment.

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

In addition, evaluation of each physical property was calculated | required as follows.

(1) Izod impact strength of the weld part By injection molding using a mold in which the resin flows from the left and right simultaneously and the weld part is generated in the center,
Generate a weld, insert a notch in the weld,
The Izod impact strength was measured according to ASTM-D256.

(2) Molding fluidity Injection molding was performed using a spiral mold, and the distance that the resin flowed was measured.

(3) Dispersed particle size of elastomer component A test piece obtained by injection molding is immersed in liquid nitrogen for 1 hour and then shock-split. The elastomer component of this fractured surface was extracted with hot xylene, and the fractured surface was observed with a scanning electron microscope to determine the dispersed particle size.

The types of each polymer and the meanings of symbols are shown below.

Ethylene ionomer (1): a copolymer having 94.5 mol% of ethylene, 2.0 mol% of acrylic acid, 2.2 mol% of zinc acrylate and 1.3 mol% of isobutyl acrylate as a copolymerization component, MI = 1.0 g / 10 min Ethylene ionomer (2): 94.1 mol% ethylene, 2.7 mol% acrylic acid and zinc acrylate 3.2
Copolymer having mol% as a copolymerization component, MI = 0.4 g /
10 minutes Olefin-based elastomer (EP): ethylene 90.4
Copolymer having mol% and 9.6 mol% of propylene as a copolymerization component, MI = 4.5 g / 10 minutes Kraton G1652 (hereinafter, also referred to as K): Styrene-based elastomer manufactured by Shell Chemical Co., Ltd. EC: Ethylene carbonate GL: Glycerin Example 1 Nylon 66 having a sulfuric acid viscosity of 2.86, 22.8 parts by weight and nylon 66 having a sulfuric acid viscosity of 3.76, 53.2
Parts by weight, 24 parts by weight of ethylene-based ionomer (1) and 2.0 parts by weight of ethylene carbonate were blended for 3 minutes with a tumbler blender, and then kneaded and extruded by a twin-screw extruder PCM30 manufactured by Ikegai Tekko Co., Ltd. to obtain pellets. The Izod impact strength and the molding fluidity of the weld part were measured by using the above. The results are shown in the table.

Examples 2-3, Comparative Example 1 Blending and extrusion were performed in the same manner as in Example 1 except that nylon 66 pellets having a sulfuric acid viscosity of 2.86 and nylon 66 pellets having a sulfuric acid viscosity of 3.76 were used in the ratios shown in the table. The obtained composition pellets were formed into pellets, and the Izod impact strength and molding fluidity of the welded portion were measured.
The results are shown in the table.

Comparative Example 2 The same operation and evaluation as in Example 1 were carried out except that nylon 66 and 76 parts by weight of sulfuric acid viscosity of 3.76 were used in place of the two types of nylon 66. The results are shown in the table.

Comparative Example 3 The same operation and evaluation as in Example 1 were carried out except that nylon 66 having a sulfuric acid viscosity of 3.30 was used. The results are shown in the table.

Comparative Example 4 The same operation and evaluation as in Example 1 were performed except that nylon 66 having a sulfuric acid viscosity of 2.86 was used. The results are shown in the table.

Comparative Example 5 In the same manner as in Example 1, 76 parts by weight of nylon 66 having a sulfuric acid viscosity of 3.76 and 24 parts by weight of the ethylene ionomer (1) were blended, extruded, pelletized, and the obtained composition pellet was molded. The Izod impact strength of the weld was measured. The results are shown in the table.

From the results shown in the table, it can be seen that the Izod impact strength of the weld part is low when the sulfuric acid viscosity is lower than 3.15 and when the carbonate compound is not present.

From the comparison between Examples 1 to 3 and Comparative Example 1, it can be seen that even in the combined use system of two kinds of polyamides, if the average sulfuric acid viscosity is 3.15 or more, a high weld zone Izod impact strength is exhibited.

From the comparison between Example 2 and Comparative Example 3, it can be seen that the combined use system of two polyamides is superior in both the Izod impact strength in the weld part and the molding fluidity to the single polyamide system even with the same average sulfuric acid viscosity.

From the comparison between Examples 1 to 3 and Comparative Example 2, it can be seen that the combined system in which the mixing ratio of the two polyamides is 70/30 or less is superior in molding fluidity to the single polyamide system.

Example 4 35 parts by weight of nylon 66 having a sulfuric acid viscosity of 2.86, 35 parts by weight of nylon 66 having a flow viscosity of 3.76, 22.5 parts by weight of an ethylene ionomer (1), and 7.5 parts by weight of an olefin elastomer. After blending 1.5 parts by weight of ethylene carbonate with a tumbler blender for 3 minutes, the mixture is melt-kneaded with a twin-screw extruder PCM30 manufactured by Ikegai Tekko Co., Ltd., and the strands are water-cooled and cut with a cutter to form pellets. Got The pellets were injection-molded, and the Izod impact strength of the weld and the Izod impact strength at low temperature were measured. The results are shown in the table.

Example 5 Craton G1652 in place of the olefin elastomer
The same operation and evaluation as in Example 4 were carried out except that was used.
The results are shown in the table.

Comparative Example 6 The same operation and evaluation as in Example 4 were performed except that 70 parts by weight of nylon 66 having a sulfuric acid viscosity of 3.76 was used instead of the two types of nylon 66. The results are shown in the table.

Comparative Example 7 The same operation as in Example 4 except that 70 parts by weight of nylon 66 having a sulfuric acid viscosity of 3.76 was used in place of the two types of nylon 66, and Kraton G1652 was used in place of the olefin elastomer, that is, an olefin. The same operation and evaluation as in Comparative Example 6 were carried out except that Kraton G1652 was used instead of the system elastomer. The results are shown in the table.

From the comparison with Examples 4 to 5 and Comparative Examples 6 to 7, it can be seen that the combined use system of two kinds of polyamides is superior to the single polyamide system in the Izod impact strength at the weld portion and the Izod impact strength at low temperature.

Example 6 38 parts by weight of nylon 66 having a sulfuric acid viscosity of 2.86, 38 parts by weight of nylon 66 having a fluid viscosity of 3.76, 18 parts by weight of an ethylene ionomer (1), 6 parts by weight of an olefin elastomer, and ethylene carbonate of 2. 0 parts by weight and 1.0 part by weight of glycerin were weighed, and as a blending order, nylon 66, ethylene ionomer, olefin elastomer and glycerin were first blended for 3 minutes using a tumbler blender, and then ethylene carbonate was added. For 3 minutes, and then kneaded and extruded by a twin-screw extruder PCM30 manufactured by Ikegai Tekko Co., Ltd., and the pellets thus obtained were used to measure the Izod impact strength and molding fluidity of the welded portion. The results are shown in the table.

Example 7 The same operation as in Example 6 except that the ethylene ionomer (2) was used in place of the ethylene ionomer (1),
An evaluation was made. The results are shown in the table.

Comparative Example 8 The same operation and evaluation as in Example 6 were carried out except that 76 parts by weight of nylon 66, which has a sulfuric acid viscosity of 3.30, was used in place of the two types of nylon 66. The results are shown in the table.

Comparative Example 9 Comparative Example 8 except that 1.0 part by weight of glycerin was not used.
The same operation and evaluation were performed. The results are shown in the table.

From the comparison with Examples 6 to 7 and Comparative Examples 8 to 9, it can be seen that the system with the addition of glycerin has a higher Izod impact strength in the weld portion than the system without the addition of glycerin. Further, even with the same average sulfuric acid viscosity, the sulfuric acid viscosity is 2.8 as compared with a single polyamide system.
It can be seen that the combination fluid of two kinds of polyamides, ie, Nylon 66 of No. 6 and Nylon 66 of sulfuric acid viscosity of 3.76 has better molding fluidity.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08L 25:10) (C08L 77/00 23:26) (56) Reference JP-A-53-108151 (JP, A) JP 58-23850 (JP, A) JP 53-44180 (JP, B2)

Claims (4)

[Claims] 1. A mixture of (A) a polyamide having an average sulfuric acid viscosity of 3.3 to 3.8 and a polyamide having an average sulfuric acid viscosity of 2.5 to 3.0, the former content being 70% by weight or less. is there,
Polyamide 60-9 having an average sulfuric acid viscosity of 3.15-3.80
5% by weight, (B) ethylene-based ionomer resin 40-5
(C) General formula per 100 parts by weight of the resin mixture consisting of (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each a hydrogen atom or an alkyl group, and X is The impact-resistant polyamide composition contains 0.05 to 5.0 parts by weight of at least one selected from the compounds represented by the formula: 2. A mixture of (A) a polyamide having an average sulfuric acid viscosity of 3.3 to 3.8 and a polyamide having an average sulfuric acid viscosity of 2.5 to 3.0, the former content being 70% by weight or less. is there,
Polyamide 60-9 having an average sulfuric acid viscosity of 3.15-3.80
5% by weight, (B) Mixture 4 of ethylene ionomer resin and olefin copolymer elastomer or styrene copolymer elastomer in a weight ratio of 3: 7 to 9.5: 0.5
(C) General formula per 100 parts by weight of the resin mixture consisting of 0 to 5% by weight. (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each a hydrogen atom or an alkyl group, and X is The impact-resistant polyamide composition contains 0.05 to 5.0 parts by weight of at least one selected from the compounds represented by the formula: 3. A mixture of (A) a polyamide having an average sulfuric acid viscosity of 3.3 to 3.8 and a polyamide having an average sulfuric acid viscosity of 2.5 to 3.0, the former content being 70% by weight or less. is there,
Polyamide 60-9 having an average sulfuric acid viscosity of 3.15-3.80
5% by weight, (B) ethylene-based ionomer resin 40-5
(C) General formula per 100 parts by weight of the resin mixture consisting of (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each a hydrogen atom or an alkyl group, and X is 0.05 to 5.0 parts by weight of at least one selected from the compounds represented by the formula (1), and (D) a polyhydric alcohol having 2 to 20 carbon atoms per 1 part by weight of the component (C). 1-1
An impact-resistant polyamide composition, characterized in that it contains parts by weight. 4. A mixture of (A) a polyamide having an average sulfuric acid viscosity of 3.3 to 3.8 and a polyamide having an average sulfuric acid viscosity of 2.5 to 3.0, wherein the content of the former is 70% by weight or less. is there,
Polyamide 60-9 having an average sulfuric acid viscosity of 3.15-3.80
5% by weight, (B) Mixture 4 of ethylene ionomer resin and olefin copolymer elastomer or styrene copolymer elastomer in a weight ratio of 3: 7 to 9.5: 0.5
(C) General formula per 100 parts by weight of the resin mixture consisting of 0 to 5% by weight. (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each a hydrogen atom or an alkyl group, and X is 0.05 to 5.0 parts by weight of at least one selected from the compounds represented by the formula (1), and (D) a polyhydric alcohol having 2 to 20 carbon atoms per 1 part by weight of the component (C). 1-1
An impact-resistant polyamide composition, characterized in that it contains parts by weight.