WO2006003998A1

WO2006003998A1 - Polyamide resin and multilayer moldings

Info

Publication number: WO2006003998A1
Application number: PCT/JP2005/012092
Authority: WO
Inventors: Kazunobu Sato; Tomomichi Kanda; Masashi Kurokawa
Original assignee: Mitsubishi Gas Chemical Company, Inc.
Priority date: 2004-07-02
Filing date: 2005-06-30
Publication date: 2006-01-12

Abstract

A polyamide resin obtained by subjecting a polyamide produced by melt polycondensation to crystallization and heat treatment successively. The starting polyamide produced by melt polycondensation is constituted of diamine units and dicarboxylic units, wherein m-xylylenediamine units account for at least 70 % by mole of the diamine units and a dicarboxylic unit mixture consisting of C4-20 α,ω-straight-chain aliphatic dicarboxylic units and isophthalic units at a mole ratio of 30:70 to 95:5 accounts for at least 70 % by mole of the dicarboxylic units. The crystallization is carried out by keeping the starting polyamide in the presence of 1 to 30 % by weight of water based on the polyamide at 70 to 120˚C for 0.5 to 4 hours. The heat treatment is carried out by keeping the starting polyamide either in an inert gas atmosphere or under a reduced pressure at a temperature ranging from the melting point of the starting polyamide minus 50˚C to that minus 10˚C for 1 to 12 hours.

Description

Specification

Polyamide resin and multilayer molded body

Technical field

[0001] The present invention relates to a polyamide resin having a specific composition and a multilayer molded article that has been subjected to a specific heat treatment. Specifically, the present invention relates to barrier properties, mechanical properties, chemical resistance, heat resistance and the like. In addition, the present invention relates to a heat-treated polyamide resin having excellent moldability and a multilayer molded body.

Background art

[0002] Polyamides are widely used as materials for injection molded articles such as automobiles and electric / electronic parts because they have excellent mechanical performance. It is also used as a packaging material for food, beverages, medicines, electronic components, and so on. Among them, polyamides obtained by polycondensation reaction of xylylenediamine and aliphatic dicarboxylic acids (hereinafter referred to as “MX nylon”), especially polyamides that can also obtain metaxylylenediamine and adipic acid power (polyamides) Since MXD6) has low permeability to gaseous substances such as oxygen and carbon dioxide, it is used as a gas barrier material in molded articles such as films and bottles.

[0003] In recent years, a fuel container made of resin for resin manufactured by blow molding has attracted attention in terms of weight reduction, elimination of fouling treatment, improvement in shape flexibility, reduction of processing man-hours and full automation of manufacturing. Alternatives to metal fuel containers are advancing. However, although polyethylene (high-density polyethylene) that has been used in the past has excellent mechanical strength, molding processability, and economic efficiency, it has a poor barrier performance against fuel, making it impossible to comply with regulations on fuel permeation. ing.

[0004] For this reason, a container having a fluorine-treated inner surface and a multilayer container in which a polyamide-polyethylene alcohol copolymer having a fuel barrier property is provided between polyethylene layers as a barrier layer have been proposed ( For example, see Patent Documents 1 to 5). Fluorine treatment is not used at present because it requires safety in handling hazardous gases and requires complicated processes such as fluorine recovery after treatment. Although the permeation amount of the fuel can be reduced to some extent by providing the noria layer, the noria property to the fuel is not perfect. If the thickness of the barrier layer is increased, the impact absorption at the time of collision will be reduced or the weight will be reduced. Due to inconveniences such as increase and cost increase, it was difficult to improve the fuel barrier property. Therefore, it was difficult for the proposed multilayer container to fully meet the regulations that will be strengthened in the future. The use of ethanol as a fuel is being considered because the use of fossil fuels and the emission of carbon dioxide and carbon dioxide can be reduced by adding ethanol to gasoline. Since conventional noria materials such as nylon 6 and ethylene butyl alcohol copolymer are inferior in noria properties to alcohols, materials having higher barrier properties are desired.

[0005] Fuel containers are usually molded by the direct blow method. Since the conventional noria materials described above are inferior in heat resistance, gels are liable to occur due to the retention of the resin if the temperature of the resin increases during molding. For this reason, it is difficult to recycle burrs generated during molding, or it is necessary to switch to a resin with excellent thermal stability when operating and shutting down the equipment. There is a problem with effective use. In particular, in direct pro-molding, if the melt viscosity of the resin is low, drawdown occurs, resulting in problems such as the thickness of the resulting product being too thin or uneven thickness. On the other hand, if the molding temperature is too high, the polyolefin used for the outer layer is melted to lower the viscosity and cause drawdown, which is not preferable.

[0006] Patent Document 1: Japanese Patent Laid-Open No. 3-32815

Patent Document 2: JP-A-5-345349

Patent Document 3: JP-A-6-340033

Patent Document 4: JP-A-9-29904

Patent Document 5: Japanese Patent Laid-Open No. 2001-97053

Disclosure of the invention

[0007] The present invention is intended to solve the above-mentioned problems of the prior art and to provide a noria material excellent in barrier properties, mechanical properties, chemical resistance, heat resistance and moldability.

[0008] As a result of diligent studies to achieve the above object, the present inventors have obtained a polyamide resin having a specific monomer composition ratio obtained by melt polycondensation by further heat-treating under specific conditions. The present inventors have found that polyamide resin has excellent barrier properties, mechanical properties, chemical resistance, heat resistance and moldability, and have completed the present invention.

[0009] That is, the present invention comprises a diamine unit and a dicarboxylic acid unit, 70 is the mole ^_0/0 or more force xylylene § Min units, 70 mole ^_0/0 or more of the dicarboxylic acid unit having 4 to 20 carbon atoms a, .omega.-linear aliphatic dicarboxylic acid unit and isophthalic acid unit Polymer Α obtained by melt polycondensation, which is a mixed dicarboxylic acid unit having a molar ratio of 30: 70-95: 5, is present in the presence of 1 to 30% by weight of water with respect to polymer A, and Crystallization by maintaining at 70 to 120 ° C for 0.5 to 4 hours under an inert gas stream or under reduced pressure, and then the melting point of polymer A—50 ° C. to melting point of polymer A—10 The present invention relates to a polyamide resin (heat treated polyamide resin) obtained by heat treatment for 1 to 12 hours at a temperature of ° C.

The present invention also relates to a multilayer molded body comprising at least one barrier layer made of the heat-treated polyamide resin and another layer having another thermoplastic resin power.

BEST MODE FOR CARRYING OUT THE INVENTION

[0010] The heat-treated polyamide resin of the present invention is obtained by crystallizing a polyamide resin (polymer A) obtained by polycondensation of a diamine component and a dicarboxylic acid component in a molten state, and further calo-heat-treating under specific conditions. Is obtained.

[0011] In the heat-treated polyamide resin, 70 mol% or more, preferably 75 mol% or more, more preferably 80 mol% or more (including 100 mol% of each) of diamine units is metaxylylenediamine units. Examples of diamine components other than metaxylylenediamine include aliphatic diamines such as tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, otamethylene diamine, nonamethylene diamine, para-phenylenediamine, And diamines having an aromatic ring such as paraxylylenediamine; and alicyclic diamines such as bis (aminomethyl) cyclohexane. Heat treatment polyamide榭脂is a unit derived from di Amin components other than the m-xylylenediamine § Min, may contain 30 mole ^_0/0 following total Jiamin units (including zero).

[0012] In heat-treated polyamide resin, 70 mol% or more of dicarboxylic acid units, preferably 80 mol% or more, more preferably 90 mol% or more (each including 100 mol%) is a 4 or 20 carbon atoms, ω —A mixed dicarboxylic acid unit consisting of a linear aliphatic dicarboxylic acid unit and an isophthalic acid unit. The molar ratio of α, ω-linear aliphatic dicarboxylic acid unit having 4 to 20 carbon atoms and isophthalic acid unit is 30:70 to 95: 5, preferably 40:60 to 95: 5, more preferably 50: 5 0 to 90:10, more preferably 60:40 to 85:15. Isophthalic acid units within this range When included, the barrier properties against methanol, ethanol and methyl tert butyl ether (M TBE) are improved.

Specific examples of a, ω linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, dodecanedioic acid. Etc. can be illustrated. Of these, adipic acid is preferred.

[0013] By including the mixed dicarboxylic acid unit as described above, the melting point of the heat-treated polyamide resin is reduced compared to the case where only the ex, ω linear aliphatic dicarboxylic acid unit having 4 to 20 carbon atoms is included. Since molding can be performed at a low temperature, the molding energy can be reduced and the molding cycle can be shortened. In addition, the melt viscosity of the heat-treated polyamide resin increases and molding defects such as drawdown can be avoided, so that molding processability is improved. Other dicarboxylic acid components other than oc, ω-linear aliphatic dicarboxylic acid and isophthalic acid having 4 to 20 carbon atoms include phthalic acid compounds such as terephthalic acid and orthophthalic acid, 1, 2 naphthalenedicarboxylic acid, 1, 3 Naphthalene dicarboxylic acid, 1, 4 naphthalene dicarboxylic acid, 1, 5 naphthalene dicarboxylic acid, 1, 6 naphthalene dicarboxylic acid, 1, 7 naphthalene dicarboxylic acid, 1, 8 naphthalene dicarboxylic acid, 2, 3 naphthalene dicarboxylic acid, 2, 6 Naphthalenedicarboxylic acid such as isomers such as naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid. Heat treatment polyamide榭脂is, oc of the 4 to 20 carbon atoms, a unit derived from a dicarboxylic acid component other than ω-linear aliphatic dicarboxylic acid and isophthalic acid, the total dicarboxylic acid monomer position of ³ 〇 mole ^o / ₀ or less ( (Including zero).

[0014] The heat-treated polyamide resin is obtained by polymerizing the diamine component and the dicarboxylic acid component in a molten state to produce a polymer soot, crystallizing the polymer A, and further heat-treating under specific conditions. Manufactured from Yuko.

In the above melt polycondensation, monocarboxylic acids such as benzoic acid, propionic acid and butyric acid; polyvalent carboxylic acids such as trimellitic acid and pyromellitic acid; carboxylic acid anhydrides such as trimellitic anhydride and pyromellitic anhydride, etc. You may cover in the range which does not impair the effect of this invention. In addition, epsilon prolatatam, _ω- Laucata ratatam, _ω- enantolactam, etc .; An amino acid such as an acid is effective for the present invention.

It can be added within the range.

In melt polycondensation, for example, a nylon salt composed of metaxylylenediamine, adipic acid and isophthalic acid is heated in the presence of water under pressure, and polymerized in a molten state while removing the added water and condensed water. It can be done by a method. Alternatively, metaxylylenediamine can be directly added to a molten adipic acid and isophthalic acid mixture and polycondensed under normal pressure. In this case, in order not to solidify the reaction system, methylylenediamine is continuously added to raise the reaction system so that the reaction temperature during the polycondensation is maintained above the melting point of the generated oligoamide and polyamide. It is preferable to proceed the polycondensation while warming.

Polymer A obtained by melt polycondensation has a terminal amino group concentration of 30-: LOO equivalent Zg, a terminal carboxyl group concentration of 100-30 equivalent Zg, a number average molecular weight of 11000-20000, and a melting point of 160-235 ° C. The melt viscosity is preferably 200 to 2500 Pa's (100 ^sec_1 ).

[0015] As a method of crystallizing the polymer A and then performing heat treatment in the following, for example, using a batch-type heating device such as a rotating drum, the polymer A is gently heated in the presence of water in an inert gas atmosphere or under reduced pressure. After heating, and crystallizing while avoiding fusion; further heat treatment; using a grooved stirring and heating device, heating in an inert gas atmosphere to crystallize, then hopper shape A heat treatment in an inert gas atmosphere using a heating apparatus of the above; a method of performing a calorie heat treatment using a batch heating apparatus such as a rotating drum after crystallization using a groove type stirring heating apparatus, etc. Is mentioned. In particular, a method of crystallization and heat treatment using a batch heating apparatus is preferred.

[0016] Since the polymer A obtained by the melt polycondensation has a low crystallization rate, there is a risk of problems such as adhesion to the heating apparatus and adhesion between the pellets during the heat treatment. Therefore, it is preferable to perform the heat treatment after the crystallization treatment of the polymer A in advance. 1 to 30 weight ^_0/0 of water of the polymer A Ka卩E, and gently heated at a heating rate of 0. 1 to 3 ° CZ min to around at 70 to 120, 0 at a temperature within the range. By maintaining for 5 to 4 hours, the crystallization of the polymer A proceeds, and the phenomenon of adhesion can be prevented if fusion occurs. Furthermore, after the crystallization is completed, water in the system is removed immediately, and the temperature is further raised to continuously heat the product. Therefore, efficient production can be performed without losing energy efficiency. When the amount of water is less than 1% by weight of the polymer A, there is a problem that the time for the crystallization process is increased if the polymer A may adhere to the apparatus wall during the crystallization process. On the other hand, if it exceeds 30% by weight, there is a problem that it is difficult to remove water after the completion of crystallization. Further, if the heat treatment conditions for crystallization are within the above range, the crystallinity is preferably 10% or more, but if the range is exceeded, problems such as inadequate crystallization and extension of the treatment time occur. There is a risk. Crystallization may be carried out in air, but is preferably carried out in an inert gas atmosphere or under reduced pressure (preferably 0.1 to 3.5 kPa).

[0017] By heat-treating the polymer A after crystallization, the number average molecular weight and viscosity of the polyamide resin increase, and draw-down when producing multilayer containers such as films, sheets, and bottles, sheet edges As a result, it is possible to obtain a heat-treated polyamide resin having excellent moldability. The heat treatment is performed at a temperature ranging from the melting point of the polymer A—50 ° C. to the melting point of the polymer A 10 ° C. for 1 to 12 hours in an inert gas atmosphere or under reduced pressure (preferably 0.01 to 1.33 kPa). Preferably it is done. When the heat treatment temperature is lower than the melting point—50 ° C., the heat treatment is insufficient and the effect of improving the characteristics becomes insufficient. Also, when the melting point is higher than 10 ° C, there is a problem that the polyamide resin adheres to the inner wall of the apparatus. Also, if the treatment time is less than 1 hour, there is a problem that the heat treatment is insufficient, and if it exceeds 12 hours, the effect of improving the characteristics is small for the time.

[0018] The heat-treated polyamide resin of the present invention preferably has a number average molecular weight of 16000 to 50000, more preferably 17000 to 45000 force S. When the number average molecular weight is within the above range, mechanical properties, alcohol resistance, and processability are good.

[0019] The melting point of the heat-treated polyamide resin is preferably 160 to 230 ° C, more preferably 170 to 220 ° C, and still more preferably 180 to 210 ° C. By bringing the melting point of the heat-treated polyamide resin closer to that of other thermoplastic resins, the occurrence of defects such as uneven thickness due to the molding temperature difference from the thermoplastic resin during the production of multilayer molded articles, the Coloring can be suppressed.

[0020] The melt viscosity at the shear rate lOOsec — ¹ at the molding temperature (usually 165 to 235 ° C) of the heat-treated polyamide resin is preferably 2000 to 8000 Pa's, more preferably 2500 to 700. OPa's. When the melt viscosity of the heat-treated polyamide resin is within the above range, it is possible to avoid a drawdown and a decrease in mechanical strength when producing a multilayer molded body by a hollow molding method or the like. Polyamide resin exceeding the above range is preferable because it is difficult to produce and an excessive load force S is applied during molding.

[0021] The glass transition point of the heat-treated polyamide resin is preferably 90 to 130 ° C. When the glass transition point is 90 ° C or higher, it is excellent in the noria characteristics at high temperatures. Further, the fuel permeation amount of the heat-treated polyamide resin measured by the method used in the following examples is preferably 5 gZday or less, more preferably 0.1 to 5 gZday, and still more preferably 0.1 to 2 gZday. The terminal amino group concentration is preferably 10 to 80 eq / g, more preferably 60 to 80 eq / g, still more preferably 60 to 75 eqZg, and the terminal carboxyl group concentration is preferably more preferably 80 to 10 eq. Is 50 to 10 eqZg, more preferably 40 to 15 eqZg.

[0022] The heat-treated polyamide resin may contain smectite (organic swelling smectite) treated with an organic swelling agent. Smectite is a 2-octahedron-type or 3-octahedral-type layered silicate having a charge density of 0.25 to 0.6. The 2-octahedron type includes montmorillonite, sidelite, etc. Hectrite, saponite, etc. are mentioned as the face type. Among these, montmorillonite is preferable.

[0023] The organic swollen smectite is obtained by expanding an interlayer of the layered silicate by bringing an organic swelling agent such as a polymer compound or an organic compound into contact with the layered silicate in advance.

As the organic swelling agent, a quaternary ammonium salt can be preferably used, but preferably a quaternary ammonia having at least one alkyl group or alkenyl group having 12 or more carbon atoms. Umu salts, particularly preferably quaternary ammonium halides (chloride, bromide, etc.) are used.

[0025] Specific examples of organic swelling agents include:

Trimethyl dodecyl ammonium salt, trimethyl tetradecyl ammonium salt, trimethyl hexadecyl ammonium salt, trimethyloctadecyl ammonium salt, trimethyl alkyl ammonium salt such as trimethylecoyl ammonium salt salt;

Trimethyl alcohol hum salt such as trimethyl octadecerium salt, trimethyl octadedecaluminum salt; Triethyl dodecyl ammonium salt, triethyl tetradecyl ammonium salt, trihexahexadecyl ammonium salt, triethyloctadecyl ammonium salt, etc.

Tributyl diolenorequinoleum salt such as tributyl dodecyl ammonium salt, tributyl tetradecyl ammonium salt, tribubutyl hexadecyl ammonium salt, tributyl octadecyl ammonium salt;

Dimethyldidecammonium salt, dimethylditetradecylammonium salt, dimethylditetradecylammonium salt, dimethyldihexadecylammonium salt, dimethyldioctadecylammonium salt, dimethylditalamoammum salt, etc. -Um salt;

Dimethyl dikeel ammonium salt such as dimethyl diocta de ammonium salt, dimethyl diocta de ammonium salt, etc .;

Diethyldialkyl ammonium salts such as Jetyldidodecyl ammonium salt, Jetyl ditetradecyl ammonium salt, Jetyl dihexadecyl ammonium salt, Jetyl dioctadecyl ammonium salt, etc. Dibutyldialkylammonium salts such as tildihexadecylammonium salt and dibutyldioctadecylammonium salt;

Methylbenzyl dialkyl ammonium salts such as methyl benzyl dihexadecyl ammonium salts;

Dibenzyldialkyl ammonium salts such as dibenzyldihexadecyl ammonium salts;

Trialkylmethyl ammonium salts such as tridodecyl methyl ammonium salts, tritetradecyl methyl ammonium salts, trioctadecyl methyl ammonium salts;

A trialkylethyl ammonium salt such as tridodecylethyl ammonium salt; a trialkylbutyl ammonium salt such as tridodecylbutyl ammonium salt; and

4-amino-1-n-butyric acid, 6-amino-1-n-caproic acid, 8-aminocaprylic acid, 10-aminodecanoic acid, 12-aminododecanoic acid, 14-aminotetradecanoic acid, 16-aminohexadenoic acid, Ω-amino acids such as 18-aminooctadecanoic acid. Ammonium salts containing hydroxyl and Z or ether groups, especially methyldihydroxyxetyl hydrogenated beef tallow ammonia salt, and methyldialkyl (PAG) ammonia

-Um salt, dimethyl bis (PAG) ammonium salt, jetyl bis (PAG) ammonium salt, dibutyl bis (PAG) ammonium salt, methyl alkyl bis (PAG) ammonium salt, ethyl Alkyl bis (PAG) ammonium salt, butyl alkyl bis (PAG) ammonium salt, methyl tri (PAG) ammonium salt, etyltri (PAG) ammonium salt, butyl tri (PAG) ammonium salt Salt, tetra (PAG) ammonium salt (wherein alkyl represents an alkyl group having 12 or more carbon atoms such as dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, etc., and PAG is a polyalkylene glycol residue, preferably A quaternary ammonium salt containing at least one alkylene glycol residue, such as a polyethylene glycol residue or a polypropylene glycol residue having 20 or less carbon atoms). Can be used. Among them, trimethyldodecyl ammonium salt, trimethyltetradecyl ammonium salt, trimethylhexadecyl ammonium salt, trimethyloctadecyl ammonium salt, dimethyldidodecyl ammonium salt, dimethylditetradecyl ammonium salt Nium salt, dimethyl dihexadecyl ammonium salt, dimethyl dioctadecyl ammonium salt, dimethyl ditallow ammonium salt, methyl dihydroxyethyl hydrogenated tallow ammonium salt are preferred. These organic swelling agents can be used alone or as a mixture of a plurality of types.

[0026] The blending ratio of the organic swollen smectite is preferably 1 to 20% by weight, more preferably 1.5 to 15% by weight, based on the total of the heat-treated polyamide resin and the organic swollen smectite. If the blending ratio is 1% by weight or more, an effect of improving the barrier property appears, and if it exceeds 20% by weight, an appropriate barrier property improving effect cannot be expected.

[0027] The organic swollen smectite needs to be uniformly dispersed without locally agglomerating in the heat-treated polyamide resin. The term “uniformly dispersed” as used herein means that the layered silicate is separated into flat plates in the heat-treated polyamide resin, and 50% or more of them have an interlayer distance of 5 nm or more. This interlayer distance is the distance between the centers of gravity of the flat objects. The greater the distance, the better the dispersion state, and the transparency when finally made into a film, sheet, or hollow container. In addition, the barrier properties against gaseous substances such as oxygen and carbon dioxide can be improved.

[0028] Regarding the method of adding organic swollen smectite to heat-treated polyamide resin, a method of adding organic swollen smectite during melt polymerization for polymer A production, stirring, a single screw or twin screw extruder, etc. Examples include a method of melt-kneading heat-treated polyamide resin and organic swollen smectite using various commonly used extruders. Among these, a twin-screw extruder is used in terms of productivity and versatility. The melt kneading method used is preferred.

[0029] At that time, the melt kneading temperature was adjusted to 180 to 260 ° C, the residence time was adjusted to 5 minutes or less, and the screw had at least one reverse screw element and Z or one ding disk, It is preferable to carry out while partly retaining in the part.

[0030] When the melt-kneading temperature is within the above range, the organic swollen smectite is well dispersed. Moreover, the dispersibility of layered silicate improves by providing a retention part in a screw. In general, the melt kneading time is preferably adjusted to 1 to 5 minutes from the viewpoint of dispersibility, thermal decomposition, and gel generation.

[0031] The heat-treated polyamide resin of the present invention includes other thermoplastic resins such as polyolefin, polystyrene, polyester, polycarbonate, and polyamides such as nylon 6, nylon 66, and nylon 666, as long as the effects of the present invention are not impaired. Fats, elastomers, modified polyolefins, ionomers, lubricants, mold release agents, heat stabilizers, antioxidants, UV absorbers, layered silicates, glass fibers, Co, Mn, Zn and other inorganic or organic metal salts Additives such as complexes can be added.

[0032] Examples of the thermoplastic resin used in the multilayer molded article of the present invention include polyolefin, polystyrene, polyester, polycarbonate, and polyamides such as nylon 6, nylon 66, and nylon 666. Polyolefins include linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, ultra high molecular weight high density polyethylene, polypropylene, or two or more types of olefins selected from ethylene, propylene, butene, etc. Examples thereof include copolymers and mixtures thereof. Among these, ultra high molecular weight high density polyethylene is preferably used because it is excellent in prevention of drawdown during hollow molding, impact resistance, fuel swell resistance, and water resistance. The heat that can be used in the present invention Polyolefins, polystyrenes, polyesters, polycarbonates and polyamides as exemplified above as plastic fats can be mixed with each other, mixed with other resins such as elastomers, and other materials such as carbon black and flame retardants. It is also possible to use it in admixture with additives.

[0033] The multilayer molded article of the present invention is a bottle-shaped, cup-shaped, tray-shaped, tan, or the like formed by laminating at least one layer of heat-treated polyamide resin and at least one thermoplastic resin layer. Examples include multi-layer containers such as cups. These molding methods are not particularly limited, but they are manufactured by a method of further thermoforming after extrusion molding, a melt molding method such as blow molding, a co-injection molding called sandwich molding and two-color molding. Specifically, a multilayer sheet is manufactured using a T-die extruder, thermoformed, a container is obtained by adhesion or welding, a cylindrical parison is formed using an injection molding machine or an extruder, It is manufactured by a method of professionally molding the nozzle, co-injection molding or the like in which two or more types of molten resin are sequentially injected into a mold.

The thickness of each layer varies depending on the shape of the multilayer molded body. Usually, the thickness of the barrier layer is selected from the range of 0.001 to Lmm, and the thickness of the thermoplastic resin layer is selected from the range of 0.01 to 20 mm.

[0034] An adhesive resin layer (adhesive layer) can be provided between the barrier layer and the thermoplastic resin layer constituting the multilayer molded body. The adhesive resin constituting the adhesive layer is, for example, maleic acid, acrylic acid, methacrylic acid, itaconic acid, or these acids if a thermoplastic resin layer made of polyolefins is bonded. Polyethylene, polypropylene, or a copolymer of olefins such as ethylene, propylene, and butene modified with an anhydride or the like can be used. In addition, if the thermoplastic resin layer is made of polyester or polycarbonate, an ethylene acetate butyl copolymer, an alkali or alkaline earth metal crosslinked ethylene acrylate copolymer, and an ethylene acrylate ester The power that can be exemplified by a copolymer is not particularly limited.

[0035] The noria layer of the multilayer molded body may be formed by mixing the heat-treated polyamide resin of the present invention and the thermoplastic resin. In that case, it is preferable to use olefin and Z or styrene copolymer modified with the above-mentioned adhesive resin, unsaturated power rubonic acid or its anhydride as a compatibilizing agent. In addition, heat-treated polyamide resin has viscosity and thermoplastic resin. It is desirable to adjust the mixing amount and take a dispersed state in which the heat-treated polyamide resin forms a continuous layer. As for the mixing method, if it is a publicly known method, fine resin pellets are driven and dispersed with an extruder, a method in which a resin powder is mixed and dispersed in an extruder, and dispersion is performed using a mixer. Although the method of performing etc. is mentioned, it does not specifically limit.

In the present invention, burrs and molding defects can be melted again and introduced into the multilayer molded body as a recycled layer. The recycled layer is preferably disposed on the outer layer than the barrier layer in view of the strength of the multilayer molded body.

[0037] In addition, as long as the object of the present invention is not impaired, each of the resin layers of the multilayer molded body of the present invention has a lubricant.

, Mold release agents, heat stabilizers, antioxidants, UV absorbers, layered silicates, inorganic or organic metal salts such as Co, Mn, Zn, complexes, etc. can be added.

Example

Hereinafter, the present invention will be specifically described with reference to examples and the like. In Examples and the like, the evaluation of the polyamide resin and the multilayer molded body was based on the following method.

[0039] (1) Concentration of terminal amino group of polyamide rosin

Polyamide rosin 0.3 to 0.5 g was precisely weighed and dissolved in phenol Z ethanol = 4 Zl volume solution 30 cc at 20 to 30 ° C with stirring. After complete dissolution, neutral titration with an aqueous NZ100 hydrochloric acid solution was performed using an automatic titrator manufactured by Mitsubishi Chemical Corporation.

[0040] (2) Terminal carboxyl group concentration of polyamide resin

A sample of 0.3 to 0.5 g of positive amide was obtained and stirred and dissolved in 30 cc of Penzino rare reconole at 160 to 180 ° C. under a stream of honey. After complete dissolution, cool to 80 ° C or lower under a nitrogen stream, add methanol with stirring, and use an automatic titrator manufactured by Mitsubishi Chemical Co., Ltd. Obtained by neutralization titration.

[0041] (3) Number average molecular weight of polyamide resin

The terminal amino group concentration and terminal carboxyl group concentration were calculated from the following equations. Number average molecular weight = 2 x 10 so (concentration of terminal carboxyl group + concentration of terminal amino group) [0042] (4) Melting point of polyamide resin

Using a heat flux differential scanning calorimeter manufactured by Shimadzu Corporation, measurement was performed at 10 ° CZ. [0043] (5) Melt viscosity of polyamide resin

Measured using Toyo Seiki Co., Ltd. Capillograph 1C (Cabilizer is LZD = 10) at a temperature of 2O ° C and a shear rate of lOOsec- ¹ .

[0044] (6) Gel concentration

Add PTFE 1.2g to a disk-shaped cavity with an inner diameter of 36mm and a depth of 1mm, and seal it with a PTFE lid to leave no gas phase part, and at 210 ° C, lOOkgZcm ² 30 A disc-like plate was obtained by heating and pressing for 2 seconds. The plate was inserted into a cavity of the same shape of a PTFE template preheated to 210 ° C, pressed at a press pressure of lOOkgZc m ² or more for 72 hours, and then rapidly cooled to room temperature and a sample was taken out. . Sample lOOmg was weighed and placed in 20cc of hexafluoroisopropanol (HFIP) and dissolved at room temperature for 24 hours. Thereafter, the mixture was filtered through a PTFE membrane filter (pore size: 3 μm) with a known weight, and the filter was washed with HFIP. This filter was dried with a hot air dryer for 30 minutes under conditions of Z120 ° C, and after weighing the filter, the weight percentage of HFIP insoluble matter was calculated as the gel concentration.

[0045] (7) Fuel permeation amount

Polyamide resin was charged into a single screw extruder with a diameter of 20 mm, and a 70 μm thick film was prepared at a preset temperature of 170 to 240 ° C. Two pieces of the obtained film were cut into 11 × 13 cm squares, and each was put together, and the three pieces were heat-sealed with a seal width of 10 mm to produce a bag. The obtained bag was filled with 60 g of fuel (isooctane Z toluene Z ethanol = 40 Z 40 Z 20 vol%), and the mouth was heat sealed with a seal width of 10 mm. The fuel-filled bag was left in an explosion-proof constant temperature and humidity chamber adjusted to 40 ° C / 65% RH, the fuel-filled bag was measured every day, and the amount of weight change per day was recorded. The maximum amount of weight change per day was used as the fuel permeation.

[0046] (8) Tensile elongation at break

Using an injection molding machine, an injection molded piece of polyamide resin was prepared and measured according to ASTM D638.

[0047] (9) Ethanol resistance 1

Using an injection molding machine, measure the polyamide resin injection molded piece with dimensions 3.2 X 12.7 X 127mm Produced. Using a jig with a span of 100 mm, a load (12 MPa) was applied to the injection molded piece to give it a sag. An absorbent cotton soaked with ethanol was placed on the convex surface of the flexure of the injection-molded piece and allowed to stand for one day.

[0048] (10) Ethanol resistance 2

Using a multi-layer extruder, high-density polyethylene resin (Nippon Polyethylene Co., Ltd., Novatec HD—HY540, MFR = 1.OgZ 10 minutes at 190 ° CZ2160g), adhesive resin (Mitsui Chemicals, Inc.) , Admer GT6, MFR = 0.9gZlO at 190 ° CZ2160g) and polyamide resin are charged into the extruder, respectively. High density polyethylene resin layer Z adhesive resin layer Z polyamide resin layer Z adhesive Resin layer Z High density polyethylene resin layer = 300 /

A multilayer sheet consisting of 40/100/40/300 μm was prepared. The obtained sheet was cut into a 3 × 7 cm square and allowed to stand for 3 weeks at 23 ° C. and 50% RH. Next, after immersing in ethanol for 10 minutes, the degree of peeling was observed.

[0049] Comparative Example 1

A 50-liter reactor equipped with a stirrer, a condenser, a condenser, a dripping tank, and a nitrogen gas inlet tube was charged with 12 kg (82. llmol) adipic acid and 3.41 kg (20. 53 mol) isophthalic acid. After sufficiently replacing the inside of the reactor with nitrogen, adipic acid and isophthalic acid were melted at 160 ° C under a small amount of nitrogen flow. To this, 13.75 kg (100.95 mol) of metaxylylenediamine was added dropwise over 210 minutes with stirring. During this time, the internal temperature continuously increased to 254 ° C. Water distilled with the addition of metaxylylenediamine was removed out of the system through a condenser and a condenser. After the addition of metaxylylenediamine, the internal temperature was raised to 260 ° C and the reaction was continued for 1 hour. The obtained polymer was taken out as a strand from the nozzle at the bottom of the reaction can, cooled with water and then cut into pellets to obtain polyamide 1. Table 2 shows the measurement results of the obtained polyamide 1 and multilayer sheet (ethanol resistance 2).

[0050] Example 1

3 kg of the polyamide 1 pellets obtained in Comparative Example 1 and 0.15 kg of distilled water were charged into a 10 L eggplant-shaped flask and attached to an evaporator. The flask was immersed in an oil bath, and the evaporator was driven and rotated at 40 rpm. Subsequently, evacuation was performed to ltorr (133 Pa) or less, and a replacement operation was performed 3 times to obtain a normal pressure with 99% by volume or more of nitrogen. 80 oil bath After raising the temperature to ° C, crystallization was carried out by maintaining at atmospheric pressure for 2 hours in a nitrogen atmosphere. Thereafter, the pressure was reduced to about 0.1 IkPa, the temperature of the oil bath was raised to 190 ° C., and heat treatment was performed for 5 hours to obtain polyamide 2. Table 1 shows the measurement results of the obtained polyamide 2 and multilayer sheet (ethanol resistance 2).

[0051] Comparative Example 2

Polyamide 3 was obtained in the same manner as in Comparative Example 1 except that 13.92 kg (102.20 mol) of metaxylylenediamine was added dropwise. The results are shown in Table 2.

[0052] Example 2

A polyamide 4 was obtained in the same manner as in Example 1 except that the polyamide 3 obtained in Comparative Example 2 was used. The results are shown in Table 1.

[0053] Example 3

After dry blending 97 parts by weight of the polyamide 4 obtained in Example 2 and 3 parts by weight of montmorillonite (trade name “Orben” manufactured by Shiroishi Kogyo Co., Ltd.) treated with an organic swelling agent, the mixture The compound was fed by a weighing feeder at a speed of 12 kgZ to a twin-screw extruder set with a tough-type screw having a cylinder diameter of 37 mm and a retention part due to a reverse element. Melting and kneading were performed under the conditions of a cylinder temperature of 220 ° C., a screw rotation speed of 300 rpm, and a residence time of 90 seconds, and the molten strand was cooled and solidified with cooling air, and then pelletized to obtain polyamide 5. Table 1 shows the measurement results of the obtained polyamide 5 and multilayer sheet (ethanol resistance 2).

[0054] Comparative Example 3

Table 3 shows the measurement results for ethylene-vinyl alcohol copolymer (Kuraray, trade name “EVAL F-101BJ”).

[0055] Comparative Example 4

Each measurement result of nylon 6 copolymer (Toray, trade name “Amilan CM6246”) is shown in Table 3. [0056] [Table 1] table 1

Example 1 Example 2 Example 3 Polyamide 2 (heavy iron) 1 00

Polyamide 4 (heavy top) 1 1 00 9 7 Montmorillonite (parts by weight)--3 Concentration of terminal amino groups (μ equivalent / g) 6 6 4

Terminal carboxyl S concentration (equivalent Zg) 6 4 3 9-Number average molecular weight 2 5 0 00 1 9 0 0 0 One melting point nc) 2 0 7 2 0 7

Melt viscosity (P a 's) 4000 3 5 0 0 4 5 0 0 Gel concentration (%) 0 0 1 1 Fuel permeation (g no day) 0. 7 0. 7 0' 5 Measurement showing maximum weight change Period (Day-Day) 2-3 3 2-3 3 Elongation at break (%) 5 5 2 2 2 1 Ethanol resistance 1

No cracking None None None Ethanol resistance 2

Existence of peeling Little None None

[0057] [Table 2] Table 2

Comparative Example 1 Comparative Example 2 Polyamide 1 (parts by weight) 100 1 Polyamide 3 (parts by weight) 1 100 Terminal amino group concentration (μ equivalent / g) 41 86 Terminal carboxyl group concentration (μ equivalent / g) 95 65 Number average Molecular weight 15000 1 3000 Melting point (° C) 207 207 Melt viscosity (P a · s) 1 100 1000 Gel concentration (%) 0 0 Fuel permeation (gZd ay) 0.7 0.7 Measurement period showing maximum weight change (Day to Day) 2 to 3 2 to 3 Tensile elongation at break (%) 6 6 Ethanol resistance 1

Presence / absence of cracks Crack generation Crack generation Ethanol resistance 2

Exfoliation Exfoliation Exfoliation

[0058] [Table 3] Table 3

Comparative Example 3 Comparative Example 4

EVOH (parts by weight) 1 0 0 1 Nylon 6 copolymer (parts by weight) ― 1 0 0 Terminal amino group concentration Equivalent / g) 1 3 3 Terminal carboxyl group concentration (μ equivalent / g) ― 7 8 Melting point () 1 8 3 1 9 1 Melt viscosity (P a · s) 1 8 0 0 3 1 0 0 Gel concentration (%) 7 2 1 Fuel permeation (g / day) 1 · 2 7.3 Measurement showing maximum weight change Period (Day-Day) 7-8 0-1 Industrial applicability

The heat-treated polyamide resin of the present invention is excellent in barrier properties, mechanical properties, chemical resistance, heat resistance, and moldability, so it can be used as a packaging material for foods, beverages, chemicals, etc., and as a barrier material for fuel containers. Is preferred. In particular, it is suitable as a noria material for alcohol. Therefore, the industrial significance of the present invention is great.

Claims

The scope of the claims

[1] Composed of a diamine unit and a dicarboxylic acid unit, 70 mol% or more of the diamine unit is a metaxylene diamine unit, and 70 mol% or more of the dicarboxylic acid unit is an α, ω-linear fatty acid having 4 to 20 carbon atoms The polymer た obtained by melt polycondensation, which is a mixed dicarboxylic acid unit in which the molar ratio of the aliphatic dicarboxylic acid unit to the isophthalic acid unit is 30:70 to 95: 5, is 1 to 30 with respect to the polymer A. Crystallization in the presence of weight% water and by maintaining at 70 to 120 ° C for 0.5 to 4 hours, and then the melting point of polymer A in an inert gas atmosphere or under reduced pressure—50 ° C to Melting point of polymer A—A polyamide resin obtained by heat treatment at a temperature of 10 ° C. for 1 to 12 hours.

[2] The polyamide resin according to claim 1, having a number average molecular weight of 16000 to 50000.

[3] The polyamide resin according to claim 1 or 2, which has a melting point of 160 to 230 ° C.

[4] The polyamide resin according to any one of claims 1 to 3, which has a melt viscosity of 2000 to 8000 Pa's at a shear rate lOOsec- ¹ at a molding temperature.

[5] The polyamide resin according to any one of claims 1 to 4, wherein the terminal amino group concentration is 10 to 80 eqZg.

6. The polyamide resin according to any one of claims 1 to 5, wherein the crystallization is performed in a batch heating device.

[7] The crystallization and heat treatment are continuously performed in a batch heating apparatus.

The polyamide resin according to any one of 1 to 5.

[8] The smectite treated with the organic swelling agent is contained in an amount of 1 to 20% by weight based on the total amount of the smectite treated with the polyamide resin and the organic swelling agent. The polyamide resin according to any one of the above.

[9] A multilayer molded article comprising at least one layer of a barrier layer made of the polyamide resin according to any one of claims 1 to 8, and at least one layer of a thermoplastic resin.