JP2016222903A - Resin composition for blow molding and multilayer structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for blow molding suitable for blow molding low in melt viscosity under high shear rate and high in melt viscosity under low shear rate.SOLUTION: There is provided a resin composition for blow molding containing a polyamide resin with the melting point of 200°C or lower (A) and an acid modified polyolefin resin with melt viscosity at 220°C and shear rate of 122 secof 800 to 1,500 Pa s (B) and having zero shear viscosity at 230°C of 10,000 to 1,000,000 Pa s.SELECTED DRAWING: None

Description

  The present invention provides a blow molding resin composition suitable for blow molding having a low melt viscosity at a high shear rate and a high melt viscosity at a low shear rate, and a layer comprising this composition and a gas barrier layer are laminated. A multilayer structure.

Polyamide resins have excellent mechanical properties, heat resistance, and chemical resistance, so they are used as engineering plastics in various molded products, and their use as blow molded products is also being studied.
However, since the polyamide resin is a polymer with a linear structure, it cannot be said that the strain hardening at the extension viscosity is sufficient, and furthermore, the melt viscosity at a low shear rate is small, so a large tank is formed by blow molding. When trying to do so, the extruded parison (molten cylindrical resin) is stretched by its own weight, it is difficult to keep the thickness of the tank wall constant, and it has been said that the blow moldability is poor.

Therefore, as a material excellent in blow moldability, for example, Patent Document 1 discloses a polyamide resin containing an aliphatic polyamide resin having a number average molecular weight of 25000 or more, an aromatic polyamide resin, and an acid-modified ethylene / α-olefin copolymer. A blow molding material comprising the composition is disclosed.
However, since the acid-modified ethylene / α-olefin copolymer contained in the blow molding material of Patent Document 1 has a high melt viscosity and a large effect of increasing the viscosity under a high shear rate, the addition amount is limited. As a result, there is a problem that the effect of increasing the viscosity is difficult to obtain. Moreover, since the melting point of the polyamide resin contained in the blow molding material of Patent Document 1 is high, there is also a problem that it is difficult to laminate with a heat-sensitive resin layer.

JP 2007-126591 A

  Accordingly, the present invention provides a blow molding resin composition suitable for blow molding having a low melt viscosity at a high shear rate and a high melt viscosity at a low shear rate, and a layer comprising this composition and a gas barrier layer are laminated. An object of the present invention is to provide a multilayer structure.

  As a result of intensive studies in view of the above circumstances, the inventors of the present invention contain a low melting point polyamide resin and an acid-modified polyolefin resin having a predetermined melt viscosity, and have a zero shear viscosity at 230 ° C. of 10,000 to 1,000,000 Pa · It has been found that the resin composition as s can solve the above-mentioned problems.

That is, the present invention contains a polyamide resin (A) having a melting point of 200 ° C. or less and an acid-modified polyolefin resin (B) having a melt viscosity of 800 to 1,500 Pa · s at 220 ° C. and a shear rate of 122 sec ^−1. A blow molding resin composition having a zero shear viscosity at 230 ° C. of 10,000 to 1,000,000 Pa · s.

  Moreover, this invention is a multilayer structure characterized by laminating | stacking the layer which consists of a resin composition for blow molding of this invention, and a gas barrier layer.

  The blow molding resin composition of the present invention has a low melt viscosity at a high shear rate (hereinafter also referred to as a high shear side) and a high melt viscosity at a low shear rate (hereinafter also referred to as a low shear side). Therefore, it is a resin composition suitable for blow molding. Moreover, since the melting point of the polyamide resin (A) is 200 ° C. or lower and the resin composition for blow molding of the present invention can be processed at a low temperature, PVOH (polyvinyl alcohol), EVOH (ethylene / vinyl alcohol copolymer), etc. Stable formability can be imparted even when laminated with a material having a relatively low thermal stability. Therefore, according to the blow molding resin composition of the present invention, for example, a multilayer structure in which a layer made of the blow molding resin composition of the present invention and a gas barrier layer are laminated can be stably molded.

In the resin composition for blow molding of the present invention, the melt viscosity is increased on the low shear side due to the interaction between the acid-modified group of the acid-modified polyolefin resin (B) and the polyamide resin (A), and the resin composition is acid-modified. Since the polyolefin has a low viscosity, the melt viscosity on the high shear side is estimated to be low.
When the melt viscosity of the polyamide resin (A) is high, the content of the acid-modified polyolefin resin (B) is decreased. On the contrary, when the melt viscosity of the polyamide resin (A) is low, the acid-modified polyolefin resin (B By adjusting the contents of both components such as increasing the content of B), the zero shear viscosity at 230 ° C. can be adjusted to a predetermined range.

Hereinafter, although it demonstrates in detail about the structure of this invention, these show an example of a desirable embodiment, and this invention is not specified by these content.
The resin composition for blow molding of the present invention comprises a polyamide resin (A) having a melting point of 200 ° C. or less, and an acid-modified polyolefin resin having a melt viscosity of 800 to 1,500 Pa · s at 220 ° C. and a shear rate of 122 sec ^−1. (B).

<Polyamide resin (A)>
The polyamide resin (A) used in the present invention has an acid amide bond (—CONH—) in the main chain, and examples thereof include aliphatic polyamide resins, alicyclic polyamide resins, aromatic polyamide resins, and the like. Examples thereof include polyamide resins including at least one resin selected from combinations and (co) polymers corresponding to those combinations. The monomer unit constituting the polyamide resin may be one type or two or more types.
The polyamide resin (A) used in the present invention is a polyamide having a melting point of 200 ° C. or lower. The melting point of polyamide can be determined according to JIS K7121.

  Examples of the aliphatic polyamide resin, alicyclic polyamide resin, and aromatic polyamide resin include polyamide resins derived from lactam, aminocarboxylic acid, or a combination of diamine and dicarboxylic acid.

  Examples of the lactam include ε-caprolactam, ω-enantolactam, ω-laurolactam, α-pyrrolidone, α-piperidone and the like, and examples of the aminocarboxylic acid include 6-aminocaproic acid, 7-amino. Examples include heptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

  Examples of the diamine used as a raw material for the polyamide resin derived from the above diamine and dicarboxylic acid include hexamethylene diamine, ethylene diamine, tetramethylene diamine, pentamethylene diamine, peptamethylene diamine, octamethylene diamine, nonamethylene diamine, Methylene diamine, undecane methylene diamine, dodecane methylene diamine, tridecane diamine, tetradecane diamine, pentadecane diamine, hexadecane diamine, heptadecane diamine, octadecane diamine, nonadecane diamine, eicosane diamine, 2-methyl-1,8-octane diamine , 2,2,4 / 2,4,4-trimethylhexamethylenediamine and the like; 1,3 / 1,4-cyclohexyldiamine, bis (4-amino Chlohexyl) methane, bis (4-aminocyclohexyl) propane, bis (3-methyl-4-aminocyclohexyl) methane, (3-methyl-4-aminocyclohexyl) propane, 1,3 / 1,4-bisaminomethylcyclohexane 5-amino-2,2,4-trimethyl-1-cyclopentanemethylamine, 5-amino-1,3,3-trimethylcyclohexanemethylamine, bis (aminopropyl) piperazine, bis (aminoethyl) piperazine, norbornane Examples thereof include alicyclic diamines such as dimethyleneamine; aromatic diamines such as p-xylylenediamine and m-xylylenediamine.

  Examples of the dicarboxylic acid used as a raw material for the polyamide resin derived from the diamine and the dicarboxylic acid include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and tridecanedioic acid. , Tetradecandioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosandioic acid and other aliphatic dicarboxylic acids; 1,3 / 1,4-cyclohexanedicarboxylic acid, dicyclohexanemethane-4,4′-dicarboxylic acid Examples thereof include alicyclic dicarboxylic acids such as acids and norbornane dicarboxylic acids; aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, and 1,4 / 1,8 / 2,6 / 2,7-naphthalenedicarboxylic acid.

Among these polyamide resins, an aliphatic polyamide resin and an aromatic polyamide resin are preferable from the viewpoints of economy and versatility, and an aliphatic polyamide resin is particularly preferable from the viewpoint of workability and the balance of physical properties obtained.
In addition, as a polyamide resin, each of these polyamides can be used alone, or two or more kinds of polyamides can be mixed and used. Furthermore, a copolyamide composed of a combination of two or more kinds of polyamides can be used.

Examples of the aliphatic polyamide resin include polycaproamide (nylon 6), polyaminoundecanoic acid (nylon 11), polylauryl lactam (nylon 12), polyhexamethylenediaminoadipic acid (nylon 66), and polyhexamethylenediaminosebacin. Polymers such as acid (nylon 610) and polyhexamethylene diaminododecanedioic acid (nylon 612); caprolactam / hexamethylene diamino adipic acid copolymer (nylon 6/66), caprolactam / lauryl lactam copolymer (nylon 6 / 12), caprolactam / aminoundecanoic acid copolymer (nylon 6/11), caprolactam / hexamethylenediaminoadipic acid / aminododecanoic acid (nylon 6/66/12), caprolactam / hexamethylenediamino Dipic acid / lauryl lactam (nylon 6/66/12), caprolactam / hexamethylene diamino adipic acid / hexamethylene diamino sebacic acid (nylon 6/66/610), and caprolactam / hexamethylene diamino adipic acid / hexamethylene diamino dodecane Examples thereof include (co) polymers such as acids (nylon 6/66/612). In the present invention, among these types, those having a melting point of 200 ° C. or less are used.
These aliphatic polyamide resins can be used alone or in admixture of two or more.

  Among the above aliphatic polyamide resins, one or two selected from nylon 610, nylon 11, nylon 12, nylon 612, nylon 6/66, nylon 6/11, nylon 6/12, and nylon 6/66/12 The above aliphatic polyamides are preferable, and nylon 6/66 is particularly preferably used in terms of flexibility at low temperatures, hydrogen resistance under high-pressure hydrogen, and a low melting point.

The melting point of the polyamide resin (A) used in the present invention is 200 ° C. or less, preferably 150 to 200 ° C., particularly preferably 170 to 198 ° C., more preferably 180 to 198 ° C. If the melting point is too high, the processing temperature tends to be high, and the workability of the gas barrier layer to be laminated tends to decrease. On the other hand, if the melting point is too low, the melt viscosity of the acid-modified polyolefin resin (B) is reduced during melt mixing. There is a tendency that the difference becomes large and uniform melt mixing becomes difficult.
In addition, melting | fusing point can be calculated | required according to JISK7121.

The melt viscosity of the polyamide resin (A) used in the present invention is preferably 500 to 4,000 Pa · s, particularly preferably 700 to 3,500 Pa · s, more preferably 900 at 220 ° C. and a shear rate of 122 sec ⁻¹ . ˜3,000 Pa · s.
If the melt viscosity is too high, shearing heat generation tends to occur, and the thermal stability during molding tends to decrease. On the other hand, if the melt viscosity is too low, the zero shear viscosity does not increase sufficiently and the blow moldability tends to decrease.
The melt viscosity can be measured using, for example, “Capillograph 1B” manufactured by Toyo Seiki Seisakusho.

<Acid-modified polyolefin resin (B)>
The acid-modified polyolefin resin (B) means a polyolefin resin modified with an acid, and examples thereof include those obtained by modifying a polyolefin resin with a carboxylic acid.

Examples of the polyolefin resin include homopolymers of olefin monomers such as ethylene, propylene, and butene, and random or block copolymers of two or more olefin monomers.
Among them, examples of the olefin homopolymer include polyethylene such as ultra-low density polyethylene, (linear) low density polyethylene, and high density polyethylene, polypropylene, polybutene, polymethylpentene, and the like.
Examples of olefin block copolymers include ethylene-α olefin copolymers such as ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers; propylene-ethylene copolymers. And propylene-α olefin copolymers such as propylene-butene copolymer; butene-α olefin copolymers such as butene-ethylene copolymer and butene-propylene copolymer.
Examples of the olefin random copolymer include those obtained by random copolymerization of two or more of the above olefin monomers and exhibiting low crystallinity. Specifically, for example, an ethylene-based tuffmer manufactured by Mitsui Chemicals, Inc., Examples include a toughmer series (trade name) such as a propylene-based toughmer and a butene-based toughener.

For example, the acid modification may be performed by copolymerizing a part of the monomer constituting the polyolefin resin instead of the α, β-unsaturated carboxylic acid or its derivative, or by graft reaction or the like to a part of the side chain of the polyolefin resin. It is carried out by introducing an α, β-unsaturated carboxylic acid or a derivative thereof.
Examples of the α, β-unsaturated carboxylic acid used for the acid modification include maleic acid, acrylic acid, itaconic acid, and crotonic acid. Examples of α, β-unsaturated carboxylic acid derivatives include acid anhydrides, esters, amides, imides, metal salts and the like of the above α, β-unsaturated carboxylic acids. Specific examples thereof include, for example, Maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, maleic acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, acrylamide Methacrylamide, maleic acid monoamide, maleic acid diamide, fumaric acid monoamide, maleimide, N-butylmaleimide, sodium methacrylate and the like. Of these, maleic anhydride is preferably used.

  The amount of modification in the acid-modified polyolefin resin (B) (for example, the amount of carboxylic acid for modification) is preferably 0.05 to 5% by weight with respect to the polyolefin resin as a base. If the amount of modification is too small, the compatibility of the resulting resin composition tends to be lowered, and the effects of the present invention tend not to be obtained. On the other hand, if the amount is too large, the reaction rate with the terminal amino group of the polyamide resin increases, causing a high viscosity in the melt-kneading process and, in some cases, causing gelation or tending to decrease moldability. is there.

The acid-modified polyolefin resin (B) has a melt viscosity of 800 to 1,500 Pa · s, preferably 850 to 1,250 Pa · s at 220 ° C. and a shear rate of 122 sec ⁻¹ . If the melt viscosity is too high, the difference in viscosity from the polyamide resin (A) tends to increase and the mixing property tends to decrease. Conversely, if the melt viscosity is too low, the zero shear viscosity of the composition does not increase sufficiently. The blow moldability tends to decrease.
The melt viscosity can be measured using, for example, “Capillograph 1B” manufactured by Toyo Seiki Seisakusho.

  As such an acid-modified polyolefin resin (B), a commercially available product may be used. Examples of commercially available carboxylic acid-modified polyolefin resins include “Admer”, “Tafmer” M series and MA series (Mitsui Chemicals), “Biner”, “Fusabond” (DuPont), “Orevac” (Arkema) And “Plexer” (manufactured by Equistar), “Modic AP” (manufactured by Mitsubishi Chemical Corporation), and the like.

In addition, the acid-modified polyolefin resin (B) used in the present invention is a compound in which the carboxylic acid component contained in the acid-modified polyolefin resin is partially mixed with other compounds (for example, nylon 6, It may be a modified polymer post-modified with a polyamide resin such as nylon 6/12).
Of these, the Tuffmer MA series, which is an acid-modified product of an α-olefin copolymer, is preferred because of its excellent low temperature characteristics. In addition, as acid-modified polyolefin resin (B), these acid-modified polyolefin resins can each be used independently, or 2 or more types can also be mixed and used.

<Resin composition for blow molding>
The blow molding resin composition of the present invention (hereinafter also referred to as the resin composition of the present invention) has a zero shear viscosity at 230 ° C. of 10,000 to 1,000,000 Pa · s, preferably 12,000 to 900,000 Pa · s, Particularly preferred is 15,000 to 850,000 Pa · s, and more preferred is 17,000 to 800,000 Pa · s. If the zero shear viscosity is too low, the drawdown of the parison tends to be severe and the blow moldability tends to decrease.On the other hand, if the viscosity is too high, the shape of the parison becomes unstable and the thickness becomes uneven during blow molding. Tend to be. The calculation of the zero shear viscosity can be obtained, for example, by fitting from the melt viscosity data measured with a rotary rheometer and extrapolating to a shear rate of zero.

The resin composition of the present invention has a melt viscosity at 220 ° C. and 230 ° C. and a shear rate of 122 sec ⁻¹ of preferably 800 to 5000 Pa · s, particularly preferably 1000 to 4500 Pa · s, and more preferably 1000 to 4000 Pa. -S. If the melt viscosity at a shear rate of 122 sec ⁻¹ is too low, the zero shear viscosity does not increase sufficiently and the blow moldability tends to decrease. On the other hand, if the melt viscosity is too high, shear heat generation tends to occur and heat during molding. There is a tendency for stability to decrease.

  The blending ratio of the polyamide resin (A) and the acid-modified polyolefin resin (B) in the resin composition of the present invention is not limited as long as the zero shear viscosity falls within the above range. Polyamide resin (A) / acid-modified polyolefin resin (B) = 95 / 5-60 / 40 (weight ratio) is preferable, particularly preferably 95 / 5-65 / 35 (weight ratio), and more preferably 95 / 5-70 / 30 (weight ratio). If the compounding ratio of the acid-modified polyolefin resin (B) is too small, the zero shear viscosity of the composition tends to be low and the blow moldability tends to be reduced. There is.

As a method for adjusting the zero shear viscosity at 230 ° C. of the resin composition of the present invention to 10,000 to 1,000,000 Pa · s, for example, in accordance with the melt viscosity of the polyamide resin (A), the acid-modified polyolefin resin (B) The method of adjusting a compounding ratio is mentioned. For example, when using a polyamide resin (A) having a low melt viscosity, it can be adjusted by increasing the blending ratio of the acid-modified polyolefin resin (B). Conversely, a polyamide resin (A) having a high melt viscosity is used. When it does, it can adjust by making small the compounding ratio of acid-modified polyolefin resin (B).
More specifically, for example 220 ° C., the polyamide resin (A) melt viscosity is less than 500 Pa · s or more 1500 Pa · s at a shear rate of 122 sec ^-1, 220 ° C., the melt viscosity at a shear rate of 122 sec ^-1 When the acid-modified polyolefin resin (B) of 800 to 1500 Pa · s is used, the blending ratio ((A) / (B)) is adjusted to 85/15 to 65/35 at 220 ° C. and a shear rate of 122 sec ⁻¹ . A polyamide resin (A) having a melt viscosity of 1500 Pa · s to 4000 Pa · s, and an acid-modified polyolefin resin (B) having a melt viscosity of 800 to 1500 Pa · s at 220 ° C. and a shear rate of 122 sec ⁻¹ are used. In this case, the blending ratio ((A) / (B)) may be adjusted to 95/5 to 75/25.

As a method for producing the resin composition of the present invention, a method of kneading the polyamide resin (A) and the acid-modified polyolefin resin (B) in a molten state is preferable. For the melt kneading, an extruder, a bumper mixer, a kneader ruder A known kneader such as a mixing roll or a blast mill can be used. For example, when an extruder is used, a single-screw or twin-screw extruder can be used. After melt-kneading, a method of extruding the resin composition for blow molding into a strand shape, cutting and pelletizing can be employed.
Such melt-kneading may be performed by batch-feeding the polyamide resin (A), the acid-modified polyolefin resin (B), and other resins that can be blended as necessary, or the polyamide resin (A) is biaxially mixed. While melting and kneading with an extruder, another resin or the like may be side-feeded in a molten state or a solid state.
The melt kneading temperature can be selected from the range of 100 to 300 ° C, and is usually 190 to 250 ° C, preferably 190 to 245 ° C, particularly preferably 200 to 240 ° C, and more preferably 200 to 235 ° C. is there. The residence time in the extruder is preferably 20 seconds to 5 minutes, particularly preferably 30 seconds to 2 minutes.

The resin composition of the present invention preferably has a melt tension of 15 mN or more at 230 ° C. and a shear rate of 122 sec ⁻¹ , particularly preferably 18 mN or more, and more preferably 20 mN or more. Blow moldability is further improved by the high melt tension of the resin composition. Although there is no restriction | limiting in particular about the upper limit of melt tension, Usually, it is 200 mN or less.

  The resin composition of the present invention may be blended with other resins and additives as necessary, provided that the zero shear viscosity at 230 ° C. is 10,000 to 1,000,000 Pa · s. It can be prepared by blending other resins and additives and melt-kneading. Other resins include, for example, ionomer resins, polystyrene resins, polyester resins, polyvinyl chloride resins, polyvinylidene chloride resins, acrylic resins, vinyl ester resins, polyurethane elastomers, chlorinated polyethylene resins, Examples thereof include thermoplastic resins such as chlorinated polypropylene resins, polyvinyl acetate resins, polyvinyl alcohol resins, and ethylene vinyl alcohol resins. Examples of the additive include known additives such as a plasticizer, a filler, an antioxidant, a colorant, an antistatic agent, an ultraviolet absorber, and a lubricant.

<Blow molding>
The blow molding method using the resin composition of the present invention is not particularly limited, and a known method can be used. Generally, after forming a parison using a normal blow molding machine, blow molding may be carried out, and the molding is preferably performed at a temperature 10 to 50 ° C. higher than the melting point of the polyamide resin (A). .

<Blow molding>
A blow molded product such as a tank can be formed by blow molding using the resin composition of the present invention. The blow molded product may be composed of only a layer made of the resin composition of the present invention (hereinafter also referred to as a resin composition layer), or may have a multilayer structure in which other resin layers are laminated. . In particular, when producing a high-pressure gas tank for filling hydrogen gas using the resin composition of the present invention, a multilayer in which the resin composition layer of the present invention and a layer (gas barrier layer) made of a gas barrier material are laminated. A multilayer blow molded product as the structure is preferred.

  As the gas barrier material, a polyvinyl alcohol-based resin is preferable. In particular, an ethylene / vinyl alcohol copolymer resin (EVOH resin) has a low melting point and a large difference between a melting temperature at the time of molding and a temperature at which the resin starts to decompose. ), Ethylene / vinyl alcohol copolymer resin having a 1,2-diol group in the side chain (EVOH resin containing a side chain 1,2-diol), a polyvinyl alcohol resin having a 1,2-diol group in the side chain ( Side chain 1,2-diol-containing PVA resin) is preferred. Among them, EVOH resin and side chain 1,2-diol-containing EVOH resin having an ethylene content of 5 to 60 mol%, preferably 15 to 38 mol%, particularly preferably 15 to 29 mol% have a low melting point. It is preferable in terms of high moldability and high gas barrier properties.

  The method for producing such a side chain 1,2-diol-containing PVA resin is not particularly limited, but (i) a saponified copolymer of a vinyl ester monomer and a compound represented by the following general formula (1) (Ii) a method of saponifying and decarboxylating a copolymer of a vinyl ester monomer and a vinyl ethylene carbonate represented by the following general formula (2), (iii) a vinyl ester monomer and the following general formula (3 The side chain 1,2-diol-containing PVA resin is produced by a method of saponifying and deketalizing a copolymer with 2,2-dialkyl-4-vinyl-1,3-dioxolane represented by be able to.

In general formulas (1), (2) and (3), R ^{1 to} R ⁶ each independently represents a hydrogen atom or an organic group. R ^{1 to} R ⁶ are preferably all hydrogen atoms, but may be organic groups as long as the resin properties are not significantly impaired. Although it does not specifically limit as this organic group, For example, C1-C4 alkyl groups, such as a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, are mentioned. Preferably, it may be an organic group having a substituent such as a halogen group, a hydroxyl group, an ester group, a carboxylic acid group, or a sulfonic acid group, if necessary.

In the general formulas (1), (2), and (3), X is a single bond or a bond chain, and is preferably a single bond from the viewpoint of improving gas barrier properties. The bonding chain is not particularly limited, and examples thereof include hydrocarbons such as alkylene, alkenylene, alkynylene, phenylene, and naphthylene (these hydrocarbons may be substituted with halogen such as fluorine, chlorine, and bromine). _{other, -O -, - (CH 2} O) m -, - (OCH 2) m -, - (CH 2 O) mCH 2 -, - CO -, - COCO -, - CO (CH 2) mCO- _{, -CO (C 6 H 4)} CO -, - S -, - CS -, - SO -, - SO 2 -, - NR -, - CONR -, - NRCO -, - CSNR -, - NRCS -, - _{NRNR -, - HPO 4 -,} - Si (OR) 2 -, - OSi (OR) 2 -, - OSi (OR) 2 O -, - Ti (OR) 2 -, - OTi (OR) 2 -, - OTi (OR) ₂ O—, —Al (OR) —, —OAl (OR) -, -OAl (OR) O-, and the like (wherein R is each independently an arbitrary substituent, a hydrogen atom or an alkyl group is preferred, and m is a natural number). Of these, alkylene having 6 or less carbon atoms, particularly methylene, or —CH ₂ OCH ₂ — is preferable from the viewpoints of viscosity stability and heat resistance during production.

R ⁷ and R ⁸ are each independently a hydrogen atom or R ⁹ —CO— (wherein R ⁹ is an alkyl group having 1 to 4 carbon atoms). R ¹⁰ and R ¹¹ are each independently a hydrogen atom or an organic group, and the organic group is the same as described above.
As the methods (i), (ii) and (iii), for example, the method described in JP-A-2006-95825 can be employed.

Among them, the method in terms of excellent in copolymerization reactivity and industrial handling (i) are preferred, R ¹ to R ⁶ in the general formula (2) is hydrogens, X a single bond, R ^7, R 3,4-diasiloxy-1-butene in which ⁸ is R ⁹ —CO— and R ⁹ is an alkyl group is preferred, and 3,4-diacetoxy-1-butene in which R ⁹ is a methyl group is particularly preferred. Used.
Furthermore, even if 1,3-diacetoxy-2-methylenepropane, 1,3-dipropionyloxy-2-methylenepropane, 1,3-dibutyronyloxy-2-methylenepropane or the like is introduced in combination Good.

  As the laminated structure, resin composition layer / gas barrier layer / reinforcing layer, resin composition layer / gas barrier layer / resin composition layer / reinforcing layer, resin composition layer / gas barrier layer / resin composition layer / moisture in order from the inside. Examples include impermeable thermoplastic resin layer / reinforcing layer, resin composition layer / gas barrier layer / resin composition layer / adhesive resin layer / moisture impermeable thermoplastic resin layer / reinforcing layer, and the like. Preferred is resin composition layer / gas barrier layer / resin composition layer / reinforcing layer.

  As the thermoplastic resin used for the moisture-impermeable thermoplastic resin layer, for example, a hydrophobic thermoplastic resin is preferably used. Specifically, for example, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ethylene-vinyl acetate copolymer, ionomer, ethylene- Polyethylene resins such as propylene copolymer, ethylene-α-olefin (α-olefin having 4 to 20 carbon atoms) copolymer, ethylene-acrylic acid ester copolymer; polypropylene, propylene-α-olefin (carbon number 4) ~ 20 α-olefin) polypropylene resins such as copolymers; polybutene, polypentene and other olefin homo- or copolymers, cyclic polyolefin, or olefin homo- or copolymers of unsaturated rubonic acid or its Ester graft-modified (carboxylic acid-modified polio Polyolefin resins in a broad sense such as fin resins and ester-modified polyolefin resins); polystyrene resins; polyamides such as nylon 11, nylon 12, nylon 6, nylon 66, and copolymers such as nylon 6/12 and nylon 6/66 Polyamide resins such as polyamide; vinyl ester resins such as polyvinyl chloride, polyvinylidene chloride, acrylic resins, and polyvinyl acetate; polyurethane resins; tetrafluoroethylene, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymers , Fluoropolymers such as ethylene / tetrafluoroethylene copolymer, tetrafluoroethylene / hexafluoropropylene copolymer; chlorinated polyethylene; chlorinated polypropylene; fluororesin having a polar group, heat such as thermoplastic polyurethane A plastic resin is mentioned.

  Furthermore, an adhesive resin layer may be provided between the resin composition layer of the present invention and the gas barrier layer. However, when the gas barrier layer is formed from EVOH, the adhesion between the resin composition layer of the present invention and the gas barrier layer is good. Therefore, an adhesive resin layer is not required, and a decrease in adhesive force is small even after exposure to high-pressure hydrogen. In addition, the number of layers of the multilayer structure is usually 3 to 15 layers, preferably 4 to 10 layers, including the reinforcing layers.

The thickness ratio of the gas barrier layer to the resin composition layer of the present invention is the sum of all the same layer thicknesses in the laminate, and the resin composition layer is usually thicker, and the resin composition layer relative to the gas barrier layer The thickness ratio (resin composition layer / gas barrier layer) is usually 1 to 100, preferably 2 to 20, particularly preferably 3 to 15. The thickness of the resin composition layer is usually 50 μm to 100 mm.
When the gas barrier layer is too thin, there is a tendency that high gas barrier properties are hardly obtained in the resulting multilayer blow-molded product. When it is too thick, there is a tendency for flexibility and economy to decrease.
In addition, if the resin composition layer is too thin, the multilayer blow moldability tends to decrease or the strength of the resulting multilayer blow molded product tends to decrease. The product tends to decrease.

  Moreover, when using an adhesive layer, it is usually preferable to make the gas barrier layer thicker. The thickness ratio of the gas barrier layer to the adhesive layer (gas barrier layer / adhesive layer) is usually 1 to 100, preferably 1 to 50, particularly preferably 1 to 10. The thickness of the adhesive layer is usually preferably 10 to 2000 μm. If the adhesive layer is too thin, the interlayer adhesion tends to be insufficient, and if it is too thick, the economy tends to be reduced.

As the adhesive layer, a known adhesive resin can be used, and usually a carboxylic acid-modified polyolefin resin obtained by modifying a polyolefin resin with an unsaturated carboxylic acid (or unsaturated carboxylic acid anhydride) such as maleic acid. Alternatively, a fluororesin having a polar group is preferably used. As said polyolefin resin, the polyolefin resin enumerated as a thermoplastic resin used for the above-mentioned moisture-impermeable thermoplastic resin layer can be used.
In view of the balance between economy and performance, a carboxylic acid-modified polyolefin resin is preferable, and a carboxylic acid-modified polypropylene resin, a carboxylic acid-modified polyethylene resin, or a mixture thereof is particularly preferable.
The moisture-impermeable thermoplastic resin layer and the adhesive layer are coated with known general additives, modifiers, fillers, other resins, etc. in order to improve moldability and various physical properties. You may mix | blend in the range which does not inhibit this effect.

Examples of the reinforcing layer include a reinforcing fiber layer using fibers and a reinforcing rubber layer using rubber. As the reinforcing fiber layer, for example, high-strength fibers such as polyparaphenylene benzbisoxazole (PBO) fibers, aramid fibers, and carbon fibers, nonwoven fabrics, cloths, and the like can be used. A reinforcing fiber layer is preferable, and a reinforcing fiber layer using high-strength fibers is particularly preferable.
Carbon fiber is preferably used as the reinforcing layer of a storage container such as a high-pressure gas tank. The carbon fiber is preferably a PAN system from the viewpoint of strength, and a pitch system having a high thermal conductivity is preferable from the viewpoint of controlling the thermal conductivity.

  In the case of a blow molded product having a multilayer structure having the resin composition of the present invention and a gas barrier layer, it is preferable that the average linear expansion coefficients of the materials constituting each layer of the resin layer constituting the multilayer structure are close to each other. The ratio of the average linear expansion coefficient of the resin composition layer to the gas barrier layer (resin composition layer / gas barrier layer) is usually 2 or less, preferably 0.8 to 1.8, particularly preferably 1-1. 8.

By bringing the ratio of the average linear expansion coefficient close to 1, each layer shows a similar behavior with respect to environmental changes during high pressure and depressurization of hydrogen exposure, and the gas barrier layer can follow the behavior of the resin composition layer of the present invention. Therefore, it is possible to reduce a load such as bending that the gas barrier layer receives.
As the ratio of the average linear expansion coefficient, an average linear expansion coefficient measured under the same conditions can be applied. Furthermore, it is preferable to use an average linear expansion coefficient at −70 ° C. to 40 ° C., which is a practical temperature range in high-pressure gas equipment.

  In particular, when the reinforcing layer has a sheet layer braided with the high-strength fibers or a layer formed by winding the sheet in a spiral (reinforcing fiber layer), considering the linear expansion coefficient of the reinforcing fiber layer, the multilayer structure It is preferable to select a combination of layer materials. The average linear expansion coefficient can be measured by a thermomechanical analyzer (TMA).

  What is necessary is just to select the thickness and size of a blow molded product with the use and the target heat conductivity, for example, the thickness is 1-100 mm normally, Preferably it is 2-80 mm, Most preferably, it is 2-50 mm. The size may be selected depending on the application and is not particularly limited. For example, the capacity is usually 5 to 500 L, preferably 5 to 450 L, and particularly preferably 5 to 400 L. The shape can be appropriately selected from a cylindrical shape, a prismatic shape, a barrel shape, and the like.

  The thickness of the gas barrier layer can be selected in the range of usually 0.1 to 60%, preferably 0.5 to 45% of the thickness of the blow molded product.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In the examples, “%” and “parts” mean weight basis.

[Examples 1-4, Comparative Examples 1-3]
Using the polyamide resin (A) and acid-modified polyolefin resin (B) shown below as raw materials, resin compositions for blow molding of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared. Table 1 shows the melt viscosities of the polyamide resin (A) and the acid-modified polyolefin resin (B) at 220 ° C. and a shear rate of 122 sec ⁻¹ .

(material)
<Polyamide resin (A)>
Nylon 6/66 (manufactured by DSM, Novamid 2420J, melting point (Tm) 193 ° C. [ISO 11357-3], MFR: 11 g / 10 min [230 ° C., load 2160 g, ISO 1133], melt viscosity at shear rate 122 sec ⁻¹ 1200 Pa · s (220 ° C))
Nylon 6/66 (manufactured by DSM, Novamid 2430J, melting point (Tm) 193 ° C. [ISO 11357-3], MFR: 2.6 g / 10 min [230 ° C., load 2160 g, ISO 1133], shear rate 122 sec ⁻¹ Melt viscosity 2800 Pa · s (220 ° C))
<Acid-modified polyolefin resin (B)>
Acid-modified polyethylene (manufactured by Mitsui Chemicals, Tuffmer MA8510, melting point 69 ° C., MFR: 5.0 g / 10 min [230 ° C., load 2160 g, ASTM D1238], embrittlement temperature: less than −70 ° C., shear rate 122 sec ⁻¹ Melt viscosity at 1100 Pa · s (220 ° C.))
Acid-modified polyethylene (Mitsui Chemicals, Tuffmer MH7010, MFR: 1.8 g / 10 min [230 ° C., load 2160 g, ASTM D1238], melt viscosity 1700 Pa · s (220 ° C.) at a shear rate of 122 sec ⁻¹ )

[Preparation of blow molding resin composition]
Using the raw materials, a blow molding resin composition was prepared according to the formulation shown in Table 1. The used resin composition was pelletized under the following conditions using a twin screw extruder (manufactured by Technobel). The resin composition was prepared by dry blending each resin and then performing melt kneading extrusion with a twin screw extruder.
Screw diameter: 15mm
L / D = 60
Direction of rotation: same direction Screw pattern: kneaded in two places Screen mesh: 90/90 mesh Screw rotation speed: 200 rpm
Temperature pattern: C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / D = 200/210/220/220/230/230/230/230/230 ° C.
Resin temperature: 230 ° C

[Melt viscosity]
(1) Shear rate, melt viscosity at 122 sec ⁻¹ The melt viscosity at 220 ° C. and 230 ° C. and shear rate 122 sec ⁻¹ was measured using “Capillograph 1B” manufactured by Toyo Seiki Co., Ltd.
(2) Zero shear viscosity The zero shear viscosity [η ₀ (P)] at 230 ° C. was determined as follows.
The angular velocity [ω (rad / sec)] dispersion of the shear viscosity (η *) at a measurement temperature of 230 ° C. was measured in the range of 0.01 ≦ ω ≦ 10. For the measurement, a viscoelasticity measuring device Physica MCR301 manufactured by Anton Paar was used. The sample holder was a 25 mm diameter parallel plate, and the sample thickness was about 0.3 mm. The measurement points were 6 points per ω digit. The sample used for the measurement of the shear viscosity is a small heat press machine AH-10TD manufactured by AS ONE, preheating temperature 210 ° C., preheating time 30 seconds, heating temperature 210 ° C., heating time 1 minute, heating load 1 t, cooling temperature The measurement sample was prepared by press molding to a thickness of 0.3 mm under the conditions of 20 ° C. and cooling time of 30 seconds.
The zero shear viscosity η ₀ was calculated by fitting the Cross-Arrhenius model of the following formula (Eq-1) to an actually measured rheological curve [angular velocity (ω) dispersion of shear viscosity (η *)] by the least square method.

ここで、ＢとＴ_ｂは材料定数、Ｔは温度である。

Here, B and _Tb are material constants, and T is temperature.

[Melt tension]
Using a Capillograph type 1B manufactured by Toyo Seiki Co., Ltd., a gut extruded using 230 ° C., shear rate 122 sec ⁻¹ , orifice diameter 1 mm, length 10 mm was 5 m / min, 10 m / min, 15 m / min, 20 m / min, 25 m / min. The tension when taken at min and 30 m / min was measured, and the average was taken as the melt tension.

[Drawdown test]
Using each of the pellets of Examples 1 to 4 and Comparative Examples 1 to 3, extrusion was performed under the following conditions with a twin screw extruder (Technobel), and the time for the molten resin to fall from the strand die to the ground was measured. .
Screw diameter: 15mm
L / D = 60
Rotation direction: same direction Screw: kneaded in two places Set temperature: C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / D = 200/200/210/220/230/230/230/230/225 ° C.
Screen mesh: 90/90 mesh Screw rotation speed: 200 rpm
Resin temperature: 225 ° C
Discharge rate: 1kg / hr
Die: 1 hole strand die Distance from strand die to ground: 1000mm

[Multilayer molding test of multilayer structure]
Using the blow molding resin composition pellets of Example 1, EVOH (Nippon Synthetic Chemical Industry Co., Ltd., Soarnol DT2904RB, ethylene content 29 mol%) pellets and HDPE (Nippon Polyethylene Co., Ltd., Novatec HD) pellets, feedblocks were used. A multilayer forming test of a multilayer structure was performed by a multilayer extrusion apparatus equipped with a three-layer, five-layer multilayer T die under the following conditions.
That is, is it possible to perform multilayer molding of a multilayer structure (film) including a blow molding resin composition, an EVOH layer as a gas barrier layer, and an HDPE layer as a moisture-impermeable thermoplastic resin layer in the following layer configuration: As a result, multilayer molding was possible.
Layer structure: HDPE layer / resin composition layer for blow molding / EVOH layer / resin composition layer for blow molding / HDPE layer = 85/10/10/10/85
Intermediate layer extruder (EVOH): 40 mm (diameter) single screw extruder (barrel temperature: 230 ° C.)
Upper and lower layer extruder (HDPE): 40 mm (diameter) single screw extruder (barrel temperature: 250 ° C.)
Middle upper and lower layer extruder (resin composition for blow molding): 32 mm (diameter) single screw extruder (barrel temperature: 230 ° C.)
Die: 3 types, 5 layers, feed block type T die (die temperature: 240 ° C)
Roll temperature: 50 ° C

As shown in Table 1, since the resin compositions for blow molding of Examples 1 to 4 have a zero shear viscosity at 230 ° C. of 10,000 to 1,000,000 Pa · s, the melt viscosity is high and blow molding at a low shear rate. It turns out that it is excellent in property. Moreover, when preparing the resin composition for blow molding, melt kneading extrusion can be easily performed, so that it can be seen that the melt viscosity is low under a high shear rate. Furthermore, since a good multilayer structure (film) was obtained in a multilayer molding test of a multilayer structure including an EVOH layer, a multilayer structure including a resin composition layer for blow molding and an EVOH layer under general molding conditions It can be seen that multilayer molding of the body is possible.
In addition, the resin compositions for blow molding of Examples 1 to 4 have a melt tension of 15 g or more at 230 ° C. and a shear rate of 122 sec ⁻¹ and 15 seconds or more in a drawdown test. It turns out that it is excellent in drawdown property and desirable as a resin composition for blow molding.

The blow molding resin composition and multilayer structure of the present invention include a fuel tank such as a high-pressure gas tank of hydrogen gas, a fuel filler tube, a fuel delivery pipe, a spoiler, an air intake duct, a resonator, and other various hoses, tubes, and tanks. It can be used for various applications such as automobile parts, machine parts such as pipes, household and office supplies, building material related parts, furniture parts.

Claims (3)

A polyamide resin (A) having a melting point of 200 ° C. or less, and an acid-modified polyolefin resin (B) having a melt viscosity of 800 to 1,500 Pa · s at 220 ° C. and a shear rate of 122 sec ⁻¹ , at 230 ° C. A blow-molding resin composition characterized by having a zero shear viscosity of 10,000 to 1,000,000 Pa · s. 2. The blow molding resin composition according to claim ¹ , wherein a melt tension at 230 ° C. and a shear rate of 122 sec ⁻¹ is 15 mN or more.   A multilayer structure comprising a layer made of the blow molding resin composition according to claim 1 and a gas barrier layer.