JPH04288339A - Polyamide blow molding - Google Patents

Abstract

PURPOSE:To produce a polyamide blow molding especially a three-dimensional blow molding excellent in heat resistance, residence stability in a molten state and impact resistance by mixing a specified polyamide with a specified resin and a heat resistance improver to form an intimate mixture improved in residence characteristics in a molten state. CONSTITUTION:A polyamide blow molding made from a mixture of 100 pts.wt. intimate mixture comprising 50-95wt.% crystalline polyamide (A) comprising 50-90wt.% hexamethyleneadipamide component, 5-40wt.% hexamethyleneterephthalamide component and 5-30wt.% hexamethyleneisophthalamide component and satisfying the relationships: melting temperature (Tm)>=225 deg.C and crystallization temperature (Tc)<=230 deg.C and 5-50wt.% ethylene ionomer resin and/or carboxy-modified elastomer (B) and having a melt viscosity satisfying formulas I and II and 0.001-10 pts.wt. heat resistance improver (C), wherein the mean particle diameter of the dispersed phase comprising component B dispersed in the polyamide matrix phase is 10mum or below.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a polyamide plastic blow molded product that has excellent heat resistance, impact resistance, chemical resistance, road antifreeze resistance, low water absorption, and dimensional stability. Specifically, polyamide is blended with an ethylene-based ionomer resin and/or a carboxy-modified elastomer and a heat resistance improver to form an intimate mixture with particularly improved melt retention characteristics of the polymer, resulting in heat resistance and melt retention stability. The present invention relates to polyamide blow-molded products with excellent properties and impact resistance, particularly three-dimensional blow-molded products.

0002

[Prior Art] Polyamide resins are widely used as engineering plastics due to their excellent physical properties, but in order to make use of these excellent properties for use in a wider range of applications, polyamide resins are not necessarily satisfactory materials. do not have. For example, polyamides generally have the property that the change in melt viscosity with respect to shear rate is small, that is, the dependence of melt viscosity on shear rate is small.
Therefore, it is substantially difficult to obtain blow-molded products for large-capacity containers. In other words, when blow molding is performed using a normal screw-type blow molding machine, the raw material polymer is
In this case, it is desirable to have a low melt viscosity in terms of extruder power and productivity.On the other hand, when forming a parison from molten polymer, the polymer extruded from the die is plasticized at a high shear rate. - It is preferred to have a high melt viscosity at low shear rates in order to maintain sufficient melt morphology and obtain uniformity of dimensions and wall thickness of the molded article. Therefore, in order to obtain large-sized blow-molded products with good dimensional stability, it is first necessary to have a high melt viscosity.
Merely having a high melt viscosity of the raw material polymer is not sufficient; it is an extremely important requirement that the melt viscosity be highly dependent on shear rate. Furthermore, although polyamide is considered to be a relatively strong material, its toughness and impact resistance largely depend on temperature and moisture content. ,
When it is completely dry or at low temperatures, it becomes a quite brittle material. Therefore, in order to obtain polyamide blow-molded products that have truly high practical value as commercial products, one of the important problems that must be overcome is the improvement of impact resistance at low temperatures and low moisture absorption. Furthermore, as the weight of automobiles has been reduced recently, the use of plastic in engine compartments has led to a demand for materials with more heat resistance, and materials that have heat resistance as well as impact resistance at low temperatures and low moisture absorption are desired.

As described above, although polyamide has various excellent properties, it is currently not fully utilized, especially as blow molded products, due to the drawbacks mentioned above. The emergence of blow molded products that have excellent impact resistance and heat resistance at low temperatures and low moisture absorption, which are made of polyamide materials that have high melt viscosity without sacrificing the useful properties of polyamides and whose shear rate dependence is large, has been a major development in this industry. The reality is that it is long awaited.

The use of polyamides for blow molding applications is already widely known and we have developed a method for producing polyamides with melt viscosity properties suitable for the production of large extrusion and blow molded products. We have already made a few proposals regarding this. The outline is as follows. That is, a method in which a polyfunctional epoxy compound containing a vinyl epoxy group and a vinylene epoxy group is added to polyamide, mixed and heated and melted (Japanese Patent Publication No. 48-7509)
Alternatively, a method in which a diamine salt of trimesic acid is added during polymerization of a polyamide monomer such as lactam (JP-A-50-2790, JP-A-50-2791,
50-3193, 50-104297, etc.), a branched chain is introduced into a polyamide molecule. The branched polyamide produced by this method certainly has good viscosity stability, high melt viscosity, and a large change in melt viscosity with respect to shear rate, which are characteristics suitable for obtaining blow-molded products. There was no improvement in impact resistance, and a blow-molded product with excellent impact resistance, especially at low temperatures and low moisture absorption, could not be obtained. Next, we recognized that an effective way to solve this drawback, that is, to improve the impact strength of branched polyamides, is to blend ethylene-based ionomer resins, ethylene-vinyl acetate copolymers, etc. into branched polyamides. Showa 52-32
Furthermore, it was discovered that nitrile rubber is extremely effective as an impact resistance improver for general polyamides (Japanese Patent Laid-Open No. 53-21252). Subsequently, we discovered that a mixture of polyamide, ethylene-based ionomer resin, and/or carboxy-modified nitrile rubber was a material with excellent melt viscosity characteristics and impact resistance, even compared to general polyamide (Japanese Patent Publication No. 55 -416
Publication No. 59).

[0005]

[Problems to be Solved by the Invention] However, even when trying to obtain a three-dimensional blow-molded product with a relatively long parison length using such prior art materials, the appearance of the molded product is poor, and furthermore, the heat resistance is poor or the heat resistance is poor. Even if the material was good, it could not be said to be a sufficiently satisfactory material for producing three-dimensional blow molded products because the parison solidified quickly and a long parison could not be obtained.

The object of the present invention is to solve the above-mentioned conventional problems, and to create a product that has excellent chemical resistance, heat resistance, melt retention stability, and impact resistance, and is also capable of forming three-dimensional blow molded products. An object of the present invention is to provide a polyamide blow-molded product using a polyamide-based material.

[0007]

[Means for Solving the Problems] That is, the present invention provides A(
a) Hexamethylene adipamide component (hereinafter abbreviated as 66) 50-90% by weight, (b) hexamethylene terephthalamide component (hereinafter abbreviated as 6T) 5-40% by weight, (c)
A polyamide consisting of 5 to 30% by weight of hexamethylene isophthalamide component (hereinafter abbreviated as 6I), which has a melting point (
Tm), 50 to 95% by weight of a crystalline polyamide whose crystallization temperature (Tc) satisfies Tm≧225°C and Tc≦230°C, and B: 5 to 50% by weight of ethylene ionomer resin and/or carboxy-modified elastomer In intimate mixture with 100 parts by weight of C heat resistance modifier 0.001
~10 parts by weight of an ethylene ionomer resin and/or a carboxy-modified elastomer dispersed in a polyamide matrix phase, the polyamide composition having a melt viscosity satisfying formula (I) and formula (II). This is a polyamide blow molded product in which the average particle size of the dispersed phase consisting of - is 10 microns or less.

[0008]lnμa10≧10.50−0.04
(T-Tm)...(I) μa
10/μa1000≧3.3
......(II) (in the above formula, Tm: melting point (°C) of polyamide
: Temperature (Tm+10℃) or higher (Tm+70℃) or lower (
℃) μa10: Temperature T (℃), shear rate 10 (sec
-1) Melt viscosity (poise) μa1000: temperature T (℃), shear rate 1000 (s
The melt viscosity (poise) in ec-1) is shown. ) In other words, the feature of the present invention is to optimize the melting point and crystallization temperature of the polyamide by specifying the composition of each polyamide component, and to create an intimate mixture of this polyamide with an ethylene ionomer resin and/or a carboxy-modified elastomer. We specified the melt viscosity properties of materials made of heat resistance modifiers and the intimate mixing state of the dispersed phase in blow-molded products. This makes it possible to obtain blow-molded products with excellent impact resistance at high temperatures and low temperatures, and with improved melt retention stability by adding a heat-resistance improver, and prevents material deterioration even in blow-molding machines equipped with an accumulator. The present invention is based on the discovery that a longer parison can be stably and easily obtained without causing any problems, and that it is particularly effective for three-dimensional blow molding.

The melt viscosity of a composition obtained by adding a heat resistance improver to an intimate mixture of polyamide, ethylene ionomer resin and/or carboxy-modified elastomer, which is the raw material for obtaining the blow molded article of the present invention, is expressed by the above formula. It is necessary that (I) and (II) are satisfied.

Formula (I) is a formula that defines the viscosity above a certain level necessary for blow molding, and if the melt viscosity does not satisfy formula (I), the viscosity is low and blow molding cannot be performed satisfactorily. Generally, the melt viscosity of a polymer is expressed as a function of the measurement temperature and shear rate, but the measurement temperature is naturally determined by the melting point and softening point of the polymer, so when discussing a specific value of melt viscosity, the measurement temperature and The difference in melting point, i.e. (T-Tm
) is appropriate to display as a parameter. Melt viscosity is measured using an ordinary capillary viscometer, and ASTM-D-1
This is a value measured according to the method specified in 238. The measurement temperature is generally selected from a temperature range of 10 to 70° C. higher than the melting point of the polymer in relation to the molding temperature.

[0011] Equation (II) is a formula that expresses the magnitude of the shear rate dependence of melt viscosity, and is the ratio of the melt viscosity in the low shear rate region to the melt viscosity in the high shear rate region. It is a quantification of size. If the melt viscosity characteristic does not satisfy formula (II), the change in melt viscosity with respect to the shear rate is small and blow molding cannot be performed satisfactorily, which is not preferable. Shear rate expressed by formula (II) 10 sec-1 and 1000 sec
Ratio of melt viscosity at c-1 (μa10/μa100
Although the upper limit of 0) is not specified, a value of about 20 is a common sense upper limit in view of the performance of the molding machine.

The melt viscosity of the material is expressed by the above formulas (I) and (I
It is necessary to satisfy both conditions I), and even if only one of the conditions is satisfied, a good blow molded product cannot be obtained.

The polyamide that can be used in the present invention includes (a) 50 to 90% by weight of 66 component, (b) 5% by weight of 6T component.
40% by weight, and 5 to 30% by weight of the (c) 6I component. If the amount of component 66 is less than 50% by weight, the crystallinity of the obtained polyamide will be low and the balance of physical properties such as chemical resistance will be poor.
If it exceeds 0% by weight, the crystallization temperature will exceed 230°C, making it impossible to obtain a sufficiently long parison during blow molding, which is not preferable. If the 6T component is less than 5% by weight, the melting point of the resulting polyamide will be lower than 225°C, resulting in decreased heat resistance and poor balance of physical properties; if it exceeds 40% by weight, heat resistance will improve but crystallization will occur. temperature is 2
If the temperature exceeds 30° C., it is undesirable because it promotes solidification of the parison during blow molding. Furthermore, if the 6I component is less than 5% by weight, it will essentially become a 66/6T copolymer, and although the heat resistance will improve, the crystallization temperature will also exceed 230°C, which will accelerate the solidification of the parison during blow molding. If it exceeds this amount, the 6I component is amorphous and its melting point decreases, resulting in a decrease in crystallinity and heat resistance. That is, the polyamide of the present invention lowers the crystallization temperature of nylon 66 by introducing the 6I component, improves blow moldability, and improves blow moldability.
It is based on the design concept of compensating for the decrease in heat resistance due to the addition of the 6T component by adding the 6T component. A blow moldable polyamide with well-balanced physical properties cannot be obtained without such a design concept. Furthermore, Tm≧225℃, Tc≦230℃
In order to obtain a polyamide that satisfies the conditions of 66, 6T, 6
Polymerization tests were carried out one by one within the above composition range of component I, and the Tm, Tc, and crystallinity of the obtained polyamide were determined by measuring with a differential scanning calorimeter (DSC).

[0014] Although there are no particular restrictions on the method of polymerizing polyamide, melt polymerization, interfacial polymerization, solution polymerization, bulk polymerization, solid phase polymerization, and a combination of these methods are usually used, and melt polymerization is generally the most preferred. Appropriate. The raw materials for each component are 66
, 6T, and 6I may be added to the polymerization kettle in the form of salts, or
They may also be introduced in the form of their respective monomers.

The degree of polymerization of the polyamide used here is not particularly limited, but it is usually determined from the relative viscosity (1 g of polymer is mixed with 98% concentrated hydrochloric acid 100%
ml and measured at 25°C. (same below) is 1.5 or more 5
Polyamides within the range below are desirable. Furthermore, in order to obtain stability in discharging the polymer from the polymerization kettle, it is possible to add monocarboxylic acid compounds, dicarboxylic acid compounds, monoamine compounds, diamine compounds, and derivatives thereof to the polymerization kettle together with monomers as polymerization stabilizers. It can be used as a useful method. Examples of these compounds include acetic acid, benzoic acid, stearic acid, sebacic acid, adipic acid, dodecanedioic acid, undecanoic acid, terephthalic acid, isophthalic acid, suberic acid, cyclohexanedicarboxylic acid, stearylamine, ethylenediamine, decamethylene diamine, tetra Examples include methylene diamine and hexamethylene diamine.

[0016] In a preferred embodiment, the obtained polyamide is subjected to melt polymerization, if necessary, and then further subjected to solid phase polymerization in order to obtain a desired melt viscosity.

In the solid phase polymerization, polyamide may be used as it is, or a phosphorus compound or the like may be added to the polyamide as a polymerization accelerator. As the phosphorus compound, phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid, polyphosphoric acid, and their alkaline earth metal salts can be effectively used. In particular, phosphoric acid is commonly used. The amount of the phosphorus compound added is not particularly limited, but is preferably 0.01 to 5.
%, more preferably 0.05 to 2%. One or more types of phosphorus compounds can also be used in combination. A commonly known method can be used for adding the phosphorus compound. For example, a method is preferably used in which a phosphorus compound or an aqueous solution of a phosphorus compound is added to polyamide resin pellets, powder, pieces, etc., and mixed using a Henschel mixer, tumbler, ribbon mixer, or the like. As a method of adjusting the melt viscosity, in addition to solid phase polymerization, it is also possible to melt-knead the polyamide resin to which the above-mentioned phosphorus compound is added. A known extruder can be used for melt-kneading.

The melting point of the polyamide used here is 22
It is necessary that the temperature is 5°C or higher. If the melting point is lower than 225°C, sufficient heat resistance cannot be obtained. Although there is no particular upper limit to the melting point, a value of 300° C. or lower is appropriate from the viewpoint of operability during polymerization and moldability during molding.

[0019] The crystallization temperature is 230°C or less,
This is necessary in order to obtain relatively long parisons. 230℃
If it is higher, the parison solidifies quickly and it becomes impossible to obtain the desired parison length. Although the lower limit of the crystallization temperature is not particularly limited, a temperature that allows crystallization at room temperature, ie, about 40° C., is generally appropriate. There are no particular limitations on crystallinity, and any polyamide within the composition range of the present invention can be used without any problem in crystallinity.

The ethylene ionomer resin used in the present invention is an ionic resin made by adding metal ions with a valence of 1 to 3 to a copolymer of an ethylene-containing α-olefin and an α,β-unsaturated carboxylic acid. It is a polymer. Here α, β−
Representative examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, and itaconic acid; representative examples of metal ions with a valence of 1 to 3 include Na+, K+, Ca++, and Zn+.
+ and Al+++, and the like. These ethylene-based ionomer resins are generally “Himilan” (
Various grades commercially available under the trade name (formerly known as "Surlyn A") can be used.

The carboxy-modified elastomers used in the present invention include ethylene, propylene, butene-1, butadiene, isoprene, 1,3-pentadiene, pentene-1,
4-Methylpentene-1, isobutylene, 1,4-hexadiene, dicyclopentadiene, 2,5-norbornene, 5-ethylidenenorbornene, 5-ethyl-2,5
-Norbornadiene, 5-(1'-propenyl)-2-
α,
It is a modified polyolefin obtained by introducing β-unsaturated carboxylic acid. Examples of α,β-unsaturated carboxylic acids used here are maleic acid, fumaric acid, itaconic acid, acrylic acid, crotonic acid, cis-4-cyclohexane-1
, 2-dicarboxylic acid and its anhydrides and derivatives, and maleimide and its derivatives. There are no particular restrictions on the method of introducing the α,β-unsaturated carboxylic acid, such as mixing and copolymerizing the main component olefins and the α,β-unsaturated carboxylic acid, or using a radical initiator in the polyolefin. A method such as grafting and introducing an α,β-unsaturated carboxylic acid can be used. The amount of α,β-unsaturated carboxylic acid introduced is 0.0 relative to the polyolefin.
A suitable range is 0.01 to 40 mol%, preferably 0.01 to 35 mol%.

Specific examples of carboxy-modified elastomers particularly useful in the present invention include ethylene/ethyl acrylate.
g-Maleic anhydride copolymer (“g” represents graft, same hereinafter), ethylene/methyl methacrylate-g-maleic anhydride copolymer, ethylene/ethyl acrylate-
g-maleimide copolymer, ethylene/ethyl acrylate-g-N-phenylmaleimide copolymer and saponified products of these copolymers, ethylene/propylene-g-maleic anhydride copolymer, ethylene/butene-1- g-maleic anhydride copolymer, ethylene/propylene/1,4-hexadiene-g-maleic anhydride copolymer, ethylene/
Propylene/dicyclopentadiene-g-maleic anhydride copolymer, ethylene/propylene/2,5-norbornadiene-g-maleic anhydride copolymer, ethylene/propylene-g-N-phenylmaleimide copolymer, ethylene/ Butene-1-g-N-phenylmaleimide copolymer, styrene/maleic anhydride copolymer, styrene/butadiene/styrene-g-maleic anhydride block copolymer, styrene/butadiene/styrene block copolymer with hydrogen Styrene/ethylene/butylene/styrene obtained by grafting maleic anhydride after addition
-maleic anhydride block copolymer, styrene/isoprene-g-maleic anhydride block copolymer, etc., and each of these can be used alone or in the form of a mixture.

The intimate mixture used in the present invention consists of a material obtained by intimately mixing polyamide with 5 to 50% by weight, particularly preferably 10 to 40% by weight, of an ethylene ionomer resin and/or a carboxy-modified elastomer. be done. If the amount of the ethylene-based ionomer resin and/or carboxy-modified elastomer is less than 5% by weight, not only will the effect of increasing the shear rate dependence of the melt viscosity of the mixture decrease noticeably, but also blow molding with excellent impact resistance will be achieved. unable to obtain goods. On the other hand, if the amount of ethylene-based ionomer resin and/or carboxy-modified elastomer exceeds 50% by weight, not only will the heat resistance decrease, but the characteristics of polyamide will not be exhibited, and the original purpose of a polyamide-based plastic blow molded product will be lost. This is not desirable because they are different.

[0024] The heat resistance improver used in the present invention is produced by keeping the material in a high-temperature molten state for a long time, such as when molding the polyamide composition as the material with a blow molding machine equipped with an accumulator. It is useful to add it in some cases. As the heat resistance improver, copper compounds such as copper acetate and copper halides such as copper iodide, copper chloride, and copper bromide can be used. Copper compounds are also potassium iodide, potassium chloride,
It may be used in combination with an alkali halide such as sodium iodide. In addition to these inorganic heat resistance improvers, there are antioxidants or hindered phenol compounds (for example, Ciba Geigy's product name "IRGANOX"), phosphite compounds (for example, , Ciba-Geigy's product name "IRGAFOS", etc.), thioether compounds, etc. can be suitably used. These antioxidants and antioxidants can be used singly or as a mixture of two or more.
It is effective to use a dophenol compound and a phosphite compound in combination.

The amount of these heat resistance improvers added is 0.001 to 10 parts by weight, more preferably 0.001 to 10 parts by weight, per 100 parts by weight of the intimate mixture of polyamide and ethylene ionomer resin and/or carboxy-modified elastomer. 01 to 5 parts by weight. If the amount added is less than 0.001 parts by weight, the effect as a heat resistance improver will not be exhibited;
Even if it is added in excess of parts by weight, the effect of the heat resistance improver will not change, but rather it will have an adverse effect on the properties of the material. The heat resistance improver may be added to the polyamide raw material during the polymerization of the polyamide, or may be mixed with the polyamide, ethylene ionomer resin and/or carboxy-modified elastomer.

The method of mixing the polyamide, the ethylene ionomer resin and/or the carboxy-modified elastomer, and the heat resistance improver is not particularly limited, and any commonly known method can be used. Polyamide and ethylene ionomer resin and/or carboxy-modified elastomer
A method in which pellets, powder, or pieces of a heat resistance improver are homogeneously mixed using a high-speed stirrer, and then melt-kneaded using an extruder with sufficient kneading capacity, or polyamide and ethylene-based ionomer resin and/or carboxy-modified elastomer are mixed together. A suitable method is to melt-knead and pelletize in an extruder, then add a heat resistance improver to the dried pellets and make it adhere to the surface of the pellets. It is also possible to use a method in which the homogeneously mixed mixture is not kneaded in advance in an extruder, but is directly kneaded in a molding machine during blow molding, and then molded. There are no restrictions on the blow molding method, and conventionally known methods can be used. That is, in general, after forming a parison using an ordinary blow molding machine, blow molding may be carried out at an appropriate temperature.

The materials of the present invention are particularly useful in blow molding machines having accumulators in which the polymer remains melted.

In order for the blow-molded article of the present invention obtained as described above to have excellent impact strength, both of the constituent polymers must be intimately mixed with each other. One of the methods for evaluating the mixed state of polymers is to use the particle size of the dispersed phase as an evaluation criterion, but the blow molded product of the present invention uses an ethylene ionomer as a dispersed phase dispersed in a polyamide matrix phase. - The dispersed average particle size of the resin and/or carboxy-modified elastomer portion is 10 microns or less, more preferably 5 microns or less, which improves impact resistance, especially impact resistance at low temperatures and low moisture absorption. Necessary to obtain excellent molded products. If the average particle size of the dispersed phase exceeds 10 microns, the effect of improving impact strength will be reduced, making it impossible to obtain a molded article with excellent impact resistance, especially at low temperatures and low moisture absorption. However, since the ethylene-based ionomer resin and/or carboxy-modified elastomer used in the present invention have good compatibility with polyamide, it is possible to relatively easily achieve the intimate mixing state specified herein, but more preferably It is desirable to melt-knead the mixture in an extruder before performing blow molding. Also, during blow molding, it is appropriate to use a blow molding machine equipped with a screw having a high kneading capacity. In order to examine the mixing state of the blow molded product, that is, the particle size of the dispersed phase in the matrix phase, it is sufficient to cut out a part of the molded product and directly measure the particle size using a microscope or the like.

The blow molded product of the present invention also has moldability,
It is also possible to add and introduce other components such as pigments, weathering agents, crystallization promoters, reinforcing materials, flame retardants, lubricants, mold release agents, etc. as long as the physical properties are not impaired.

The present invention will be explained in more detail with reference to Examples below. The impact resistance of the blow molded products listed in Examples and Comparative Examples was evaluated by the following method. That is, a reagent container with an internal volume of 500 ml obtained by blow molding was filled with water at 0°C, the mouth was tightly stoppered, and the container was placed on a horizontal concrete floor from a height of 2.5 m with the bottom facing downward. The container was dropped repeatedly to determine the number of drops until the container broke. This test was conducted on five containers made under certain conditions. The present invention is not limited to the following examples unless it exceeds the gist thereof.

Reference Example 1 (Production of polyamide of the present invention) 66 components (raw materials: hexamethylene diamine/adipic acid), 6T components (raw materials: hexamethylene diamine/terephthalic acid), 6I components (raw materials: hexamethylene diamine/isophthalic acid) Weigh out each monomer (acid) so that it has the composition shown in Table 1, add it to a polymerization pot, and melt-polymerize it to form a polymer.
And so. After the polymerization was completed, the mixture was discharged from the bottom of the polymerization vessel, drawn into a strand, and pelletized using a pelletizer. After drying this pellet in vacuum, various properties were measured and the results shown in Table 1 were obtained.

[0032]

[Table 1]

Example 1 Polyamide species N-1 of Reference Example 1 was solid-phase polymerized at 280°C.
, the melt viscosity at a shear rate of 10 sec-1 is μa10
=9000 poise polyamide was obtained. For this polyamide, styrene/ethylene/butylene/styrene-g-
20% by weight of a maleic anhydride block copolymer (trade name "Tuftech" M1913 (manufactured by Asahi Kasei Corporation); hereinafter abbreviated as modified SEBS) was added and mixed, and 0.03 parts by weight of copper iodide was added to 100 parts by weight of this mixture. , potassium iodide 0.0
5 parts by weight were added and further mixed. Add this mixture to 28
The mixture was melt-kneaded in an extruder with a diameter of 30 mm and set at 0° C., and then pelletized. After vacuum drying this pellet, AS
Using a melt indexer manufactured according to TM-D-1238, the shear rate was 10 sec at a temperature of 280°C.
The melt viscosities at 1 and 1000 sec-1 (μa10 and μa1000, respectively) were measured. The result is μa10=70000 poise, μa1000=8000
poise, and these values satisfied formulas (I) and (II).

[0034] Next, the pellets obtained here were made into diameter 40mmφ.
of outer diameter 2 at 280°C using a blow molding machine with an extruder of
When a parison with a thickness of 0 mm and a wall thickness of 2 mm was formed, and a 500 ml reagent bottle was molded, the condition of the parison was observed, and no sagging of the parison was observed. We were able to obtain a molded product.

[0035] A part of this molded product was cut out, and the sample was cut into an extremely thin piece using an ultramicrotome. When the particle size of the modified SEBS phase as a dispersed phase was observed using an electron microscope, it was found to be 0.8 microns on average. It was confirmed that modified SEBS was finely dispersed in the polyamide matrix.

[0036] Furthermore, when the impact resistance of the blow molded product was investigated by a drop test, the number of tests until the molded product broke was 10.
It was found that it had excellent practical impact resistance.

A parison with an outer diameter of 20 mm and a wall thickness of 2 mm was formed from the same material using a blow molding machine equipped with an accumulator, and a parison with an outer diameter of 5 mm and a length of 7 mm was formed using a three-dimensional blow molding mold.
It was molded into a pipe with a complicated shape of 0.00 mm. This material could be molded into a shape with good appearance and exact dimensions of the mold without generating decomposition gas of the polymer due to melting and retention in the accumulator and without causing the parison to sag.

Example 2 The procedure was carried out in exactly the same manner as in Example 1, except that 20% by weight of "Himilan" 1706 (ionomer resin manufactured by Du Pont, USA) was added and mixed in place of the modified SEBS used in Example 1. A composition of polyamide, "Himilan" 1706, copper iodide, and potassium iodide was obtained. The shear rate of this composition at a temperature of 280°C is 10 sec-1 and 10
The melt viscosity at 00 sec-1 is μa10 = 6500
0 poise, μa1000=7000 poise, and in this case as well, the melt viscosity value satisfied formulas (I) and (II).

[0039] Subsequently, using the same equipment as in Example 1, a 500 ml container was blow-molded under the same conditions, and the shape retention of the parison was extremely good, and a blow-molded product with uniform wall thickness was easily obtained. was completed. In addition, when the mixed state and impact resistance of this molded article were evaluated in the same manner as in Example 1, the average particle size of the "HIMILAN" 1706 phase dispersed in the polyamide matrix was 1.0 microns. It also showed excellent results in the drop test, with more than 10 tests.

A parison with an outer diameter of 20 mm and a wall thickness of 2 mm was formed from the same material using a blow molding machine equipped with an accumulator, and a parison with an outer diameter of 50 mm and a length of 7 mm was formed using a three-dimensional blow mold.
It was molded into a pipe with a complicated shape of 0.00 mm. This material could be molded into a shape with good appearance and exact dimensions of the mold without generating decomposition gas of the polymer due to melting and retention in the accumulator and without causing the parison to sag.

Comparative Example 1 A composition of polyamide and "Himilan" 1706 was prepared in the same manner as in Example 2, except that copper iodide and potassium iodide, which were the heat resistance improvers of Example 2, were not used. Obtained. Shear rate of this composition at 280°C: 10 sec
The melt viscosity at -1 and 1000 sec-1 is μa
10=65000 poise, μa1000=7000 poise, and in this case as well, the melt viscosity value satisfied formulas (I) and (II). The average particle size of “HIMILAN” 1706 phase dispersed in the polyamide matrix is 1
．． It was 0 micron.

This material was formed into a parison with an outer diameter of 20 mm and a wall thickness of 2 mm using a blow molding machine equipped with an accumulator, and a parison with an outer diameter of 50 mm and a length of 7 mm was formed using a three-dimensional blow mold.
It was molded into a pipe with a complicated shape of 0.00 mm. The polymer of this material deteriorated slightly due to melting and retention in the accumulator, and some decomposition gas was generated and the parison sagged.

Example 3 Polyamide species N-2 of Reference Example 1 was solid-phase polymerized at 270°C.
A polyamide having a melt viscosity of μa10=13000 poise at a shear rate of 10 sec-1 was obtained. For this polyamide, ethylene/propylene-g-maleic anhydride copolymer (manufactured by Exxon, trade name "Excera")
20% by weight of VA1803 (hereinafter abbreviated as modified EPR)
To 100 parts by weight of the added mixture, N,N'-hexamethylene (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide) ("IRGANOX" manufactured by Ciba-Geigy) was added.
1098) Example 1 except that 0.5 parts by weight was added.
A composition of polyamide, modified EPR, and heat resistance improver was obtained in the same manner as above. The shear rate of this composition at a temperature of 270°C is 10 sec-1 and 1000 sec-1
The melt viscosity is μa10=120000 poise, μ
a1000=9500 poise, and in this case as well, the melt viscosity value satisfied formulas (I) and (II). Subsequently, using the same apparatus as in Example 1, 500
When a ml container was blow molded, the shape retention of the parison was extremely good and a blow molded product with uniform wall thickness could be easily obtained. In addition, when the mixed state and impact resistance of this molded article were evaluated in the same manner as in Example 1, it was found that the modified EPR dispersed in the polyamide matrix was also used in this case.
The average particle size of the phase was 1.0 microns, and it showed an excellent value in the drop test, which was tested more than 10 times.

A parison with an outer diameter of 20 mm and a wall thickness of 2 mm was formed from the same material using a blow molding machine equipped with an accumulator, and a parison with an outer diameter of 50 mm and a length of 7 mm was formed using a three-dimensional blow mold.
It was molded into a pipe with a complicated shape of 0.00 mm. This material could be molded into the shape of the mold with a good appearance without generating decomposition gas of the polymer or causing the parison to sag due to melting and retention in the accumulator.

[0045]

[Effects of the Invention] By using the polyamide composition of the present invention, it is now possible to inexpensively produce blow-molded products with desirable properties that could not be achieved with existing single materials, and the excellent features of polyamide can be produced. Taking advantage of this, it has become possible to use it in various blow molded products. In particular, the polyamide composition of the present invention provides a material with heat resistance and melt retention stability, and is suitable for use in accumulators that require melt retention stability.
The recent advances in automatic technology have made it possible to mold three-dimensional blow molded products with complex shapes using a blow molding machine equipped with a mulleter.
This is of great significance as it is consistent with the movement towards weight reduction.

Claims (1)

[Claims] Claim 1: A(a) hexamethylene adipamide component
A polyamide consisting of 50 to 90% by weight, (b) hexamethylene terephthalamide component 5 to 40% by weight, and (c) hexamethylene isophthalamide component 5 to 30% by weight, melting point (Tm), crystallization temperature (Tc) is 50 to 95% by weight of crystalline polyamide satisfying Tm≧225°C Tc≦230°C, and B
Intimate mixture with 5-50% by weight of ethylene-based ionomer resin and/or carboxy-modified elastomer
100 parts by weight, C heat resistance improver 0.001-1
0 parts by weight, and the melt viscosity is according to formula (I) and (
A polyamide blow-molded product made of a polyamide composition that satisfies II), in which the average particle size of the dispersed phase made of an ethylene ionomer resin and/or a carboxy-modified elastomer dispersed in a polyamide matrix phase is 10 microns or less . ln μa10≧10.50−0.04(
T-Tm)・・・・・・(I)μa
10/μa1000≧3.3
......(II) (In the above formula, Tm: Melting point (°C) of polyamide
: Temperature (Tm+10℃) or higher (Tm+70℃) or lower (
℃) μa10: Temperature T (℃), shear rate 10 (sec
-1) Melt viscosity (poise) μa1000: temperature T (℃), shear rate 1000 (s
The melt viscosity (poise) in ec-1) is shown. )