JP2006265398A - Polyamide resin composition excellent in antifreeze liquid resistance and element for water supplying place made therefrom - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin composition having good durability, strength and heat resistance when contacting with hot water or an aqueous solution containing polyhydric alcohol such as ethylene glycol or propylene glycol as an antifreeze, and to provide elements using the composition and for water supplying place. <P>SOLUTION: The polyamide resin composition comprises (A) 95-50 wt.% copolyamide resin, which comprises (a1) 20-80 wt.% hexamethylene sebacamide unit (N610) obtained from sebacic acid and hexamethylenediamine and (a2) 80-20 wt.% hexamethylene telephthalamide unit (N6T) obtained from terephthalic acid and hexamethylenediamine, and (B) 5-50 wt.% polyphenylene sulfide resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention comprises a copolymerized polyamide resin obtained by copolymerizing nylon 610 (N610) and nylon 6T (N6T) at a specific ratio and a polyphenylene sulfide resin. In particular, the copolymerized polyamide resin and the polyphenylene sulfide resin are specified. A polyamide resin composition having good durability, strength, and heat resistance in contact with an aqueous solution containing a polyhydric alcohol such as warm water or ethylene glycol (hereinafter also referred to as “antifreeze”) by being formed into a morphology The present invention relates to a water member made of the same. In particular, the present invention relates to a water pipe member that can be suitably used for a resin pipe and a hot water circulation device using the same.

  Polyamide resins are excellent in mechanical properties such as tensile and bending strength and elastic modulus, and have good heat resistance and chemical resistance, and are used in many fields such as precision machine parts and structural materials. In the fields of automobiles, architecture, and civil engineering, metal parts are being made of resin to reduce weight and streamline assembly. Among them, polyamide resin typified by glass fiber reinforced nylon 66 resin has excellent heat resistance, oil resistance, and toughness. It is a radiator tank that is a part in an automobile engine room, floor heating that performs floor heating, and cold areas. It has been attracting attention as a material for parts that come into contact with antifreeze liquid such as pipe-like piping used in the so-called “heat system method” such as a road heating system that prevents freezing of road surfaces, and has a considerable track record of use. However, the conventional glass fiber reinforced nylon 66 resin has a tendency to decrease in strength after long-time contact with an antifreeze under a high temperature atmosphere, and further performance improvement has been desired. In order to solve this problem, a method using a composition in which a long chain aliphatic polyamide such as nylon 612, nylon 610, nylon 11, nylon 12 or the like having a lower amide group concentration than nylon 66 is used as it is or blended with nylon 66 (for example, a patent) Document 1) is disclosed. However, these methods have the disadvantage that although the antifreeze resistance is improved, the heat resistance is inferior to that of nylon 66. In addition, a method using a polyamide having an aromatic component in the molecular chain (for example, Patent Document 2) is also disclosed. However, in this method, the dimensional stability and heat resistance at the time of water absorption are surely compared with those of a polyamide resin alone. However, the polyamide containing these aromatic components has a melting point that is too high and can be melt-molded only in a very limited temperature range and residence time. In addition, a high-temperature mold equipped with an oil temperature controller or the like is necessary, and there is a problem in moldability.

  In order to complement the physical properties of such polyamide resin, combined with polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) which has excellent heat resistance, antifreeze resistance and moldability, but has problems in toughness and moldability Conventionally, a resin composition and a molded body (for example, Patent Document 3) have been proposed.

However, although these methods certainly improve the dimensional stability and heat resistance at the time of water absorption compared to the polyamide resin alone, there are drawbacks such as brittleness and easy cracking, so when using it for parts that require antifreeze resistance It was not enough.
Japanese Patent Publication No. 3-2392 JP-A-4-239530 JP-A-5-248237

  The present invention has excellent performance in all of mechanical properties, heat resistance, chemical resistance and moldability, and can suppress as much as possible the deterioration of mechanical properties due to contact with antifreeze liquid for a long time. An object of the present invention is to provide a novel polyamide resin composition and a water member made of the polyamide resin composition.

  Thus, as a result of intensive studies to solve the above-mentioned problems, the present inventors have blended polyphenylene sulfide resin at a specific ratio with a copolymerized polyamide resin obtained by copolymerizing N610 and N6T at a specific ratio. The inventors have found that the problem can be solved and have reached the present invention.

That is, the present invention
(1) (a1) 20 to 80% by weight of hexamethylene sebacamide units obtained from sebacic acid and hexamethylenediamine, (a2) 80 to 20% by weight of hexamethylene terephthalamide units obtained from terephthalic acid and hexamethylenediamine (A) a polyamide resin composition comprising 95 to 50% by weight of a copolymerized polyamide resin and (B) a polyphenylene sulfide resin of 5 to 50% by weight,
(2) The polyamide resin composition according to (1), wherein (A) the copolymerized polyamide resin forms a continuous phase, and (B) the polyphenylene sulfide resin has an average particle size of 0.01 to 3 μm in the composition. (1) a polyamide resin composition characterized by having a dispersed morphology;
(3) The polyamide resin composition of (1) or (2), comprising 95 to 50% by weight of the polyamide resin composition and (C) 5 to 50% by weight of an aliphatic polyamide resin,
(4) The polyamide resin according to any one of (1) to (3), wherein 0.5 to 100 parts by weight of (D) inorganic filler is contained with respect to 100 parts by weight of the polyamide resin composition. Composition,
(5) A water member characterized by comprising the polyamide resin composition,
(6) The water-circulating member according to (5), which is molded by at least one method selected from injection molding, injection compression molding, and compression molding,
(7) The water supply member according to (5) or (6), wherein the water supply member is a pipe,
(8) A hot water circulation device, characterized in that water or an aqueous solution containing a polyhydric alcohol is passed through a conduit constituted by the pipe according to (7),
Is to provide.

  The polyamide resin composition of the present invention and a water-repellent member comprising the same comprise a copolymerized polyamide resin obtained by copolymerizing N610 and N6T at a specific ratio and a polyphenylene sulfide resin, and in particular, a copolymerized polyamide resin and a polyphenylene sulfide resin. By forming a specific morphology, it has good durability and strength even under prolonged contact with warm water or antifreeze. Therefore, it can be suitably used as a pipe used as a pipe of a hot water circulation device represented by a radiator tank, a floor heating system, and a road heating system, which are components in an automobile engine room.

  Embodiments of the present invention will be described below.

  The (A) copolymerized polyamide resin used in the present invention comprises (a1) a hexamethylene sebacamide unit (hereinafter also referred to as nylon 610 or N610) obtained from sebacic acid and hexamethylenediamine, and (a2) terephthalic acid and hexamethylenediamine. From the hexamethylene terephthalamide unit (hereinafter also referred to as nylon 6T or N6T). The composition ratio of each component is 20 to 80% by weight for N610 and 80 to 20% by weight for N6T. The preferable composition ratio is 30 to 70% by weight of N610 and 70 to 30% by weight of N6T. When N6T is more than 80% by weight, the crystallinity is greatly lowered, and thus a sufficiently crystallized molded product cannot be obtained, and the mechanical properties, heat resistance, chemical resistance and the like are inferior. If N6T is less than 20% by weight, the melting point is low and the heat resistance is inferior, so that it is not preferable because it cannot be used for parts that require heat resistance such as a radiator tank used in an automobile engine room.

  The molecular weight of the (A) copolymerized polyamide used in the present invention is preferably 0.5 to 3.0 as a relative viscosity ηr measured at 25 ° C. in a 98% concentrated sulfuric acid solution having a sample concentration of 0.01 g / ml. Preferably it is 1.5-2.9. If ηr is lower than 0.5, the resin becomes brittle, and furthermore, the drawing from the tip of the nozzle of the cylinder becomes severe at the time of molding, which makes it impossible to mold. If ηr is higher than 3.0, the melt viscosity of the resin becomes too high, and the resin cannot be filled into the mold depending on the mold design at the time of molding.

  In addition, a copper compound is preferably used in the (A) copolymerized polyamide used in the present invention in order to improve long-term heat resistance. Specific examples of the copper compound include cuprous chloride, cupric chloride, cupric bromide, cuprous iodide, cupric iodide, cupric sulfate, cupric nitrate, and phosphoric acid. Copper, cuprous acetate, cupric acetate, cupric salicylate, cupric stearate, cupric benzoate and copper such as inorganic copper halide and xylylenediamine, 2-mercaptobenzimidazole, benzimidazole Compound etc. are mentioned. Among these, monovalent copper halide compounds are preferable, and cuprous acetate, cuprous iodide and the like can be exemplified as particularly suitable copper compounds. The amount of copper compound added is usually preferably 0.01 to 2 parts by weight, more preferably 0.015 to 1 part by weight, based on 100 parts by weight of the copolymerized polyamide resin. If the amount added is more than 2 parts by weight, the metal copper is liberated during melt molding, and the value of the product is reduced by coloring. In the present invention, an alkali halide compound can be added in combination with a copper compound. Examples of the alkali halide compound include lithium chloride, lithium bromide, lithium iodide, lithium chloride, potassium bromide, potassium iodide, sodium bromide and sodium iodide. Sodium chloride is particularly preferred.

  The (B) polyphenylene sulfide resin (hereinafter also referred to as PPS resin) used in the present invention is a polymer having a repeating unit represented by the following structural formula,

From the viewpoint of heat resistance, a polymer containing 70 mol% or more, more preferably 90 mol% or more of a polymer containing a repeating unit represented by the above structural formula is preferred. Moreover, less than 30 mol% of the repeating units of the PPS resin may be composed of repeating units having the following structure.

Since the PPS resin having a part of the structure has a low melting point, it is advantageous in terms of moldability when the melting point of the thermoplastic resin is low.

The melt viscosity of the PPS resin used in the present invention is not particularly limited as long as melt kneading is possible, but usually a resin having a viscosity of 50 to 20000 poise (320 ° C., shear rate 1000 ⁻¹ ) is preferably used, and a viscosity of 100 to 5000 poise is used. A range is more preferred.

  Such a PPS resin is generally known in the art, ie, a method for obtaining a polymer having a relatively low molecular weight described in JP-B-45-3368, or JP-B-52-12240 and JP-A-61-7332. Or a method for obtaining a polymer having a relatively large molecular weight. In the present invention, the PPS resin obtained as described above is crosslinked / polymerized by heating in air, heat treatment under an inert gas atmosphere such as nitrogen or under reduced pressure, washing with an organic solvent, hot water, aqueous acid solution, etc. Of course, it is possible to use it after performing various treatments such as activation with an acid anhydride, amine, isocyanate, or a functional group-containing compound.

  As a specific method for crosslinking / high molecular weight by heating PPS resin, it can be performed in an oxidizing gas atmosphere such as air or oxygen, or in a mixed gas atmosphere of the oxidizing gas and an inert gas such as nitrogen or argon. An example is a method in which heating is performed in a heating container at a predetermined temperature until a desired melt viscosity is obtained. The heat treatment temperature is usually 170 to 280 ° C, preferably 200 to 270 ° C. The heat treatment time is usually selected from 0.5 to 100 hours, and preferably 2 to 50 hours. By controlling both, a target viscosity level can be obtained. The heat treatment apparatus may be a normal hot air dryer or a heating apparatus with a rotary or stirring blade, but a heating apparatus with a rotary or stirring blade is used for efficient and more uniform treatment. Is more preferable.

  As a specific method for heat-treating the PPS resin under an inert gas atmosphere such as nitrogen or under reduced pressure, a heat treatment temperature of 150 to 280 ° C., preferably 200 to 200 ° C. under an inert gas atmosphere such as nitrogen or under reduced pressure. A method of heat treatment at 270 ° C. and a heating time of 0.5 to 100 hours, preferably 2 to 50 hours can be exemplified. The heat treatment apparatus may be a normal hot air dryer or a heating apparatus with a rotary or stirring blade, but a heating apparatus with a rotary or stirring blade is used for efficient and more uniform treatment. More preferably it is used.

  The PPS resin used in the present invention is preferably a PPS resin that has been subjected to deionization treatment. Specific examples of the deionization treatment include an acid aqueous solution washing treatment, a hot water washing treatment, and an organic solvent washing treatment, and these treatments may be a combination of two or more methods.

  The following method can be illustrated as a specific method when the PPS resin is washed with an organic solvent. That is, the organic solvent used for washing is not particularly limited as long as it does not have an action of decomposing the PPS resin. For example, nitrogen-containing polar solvents such as N-methylpyrrolidone, dimethylformamide, and dimethylacetamide, dimethyl sulfoxide Sulfoxides such as dimethylsulfone, sulfone solvents, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone and acetophenone, ether solvents such as dimethyl ether, dipropyl ether and tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene chloride, dichloroethane , Halogen solvents such as tetrachloroethane, chlorobenzene, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol Lumpur, phenol, cresol, alcohols such as polyethylene glycol, phenolic solvents, benzene, toluene, and aromatic hydrocarbon solvents such as xylene. Among these organic solvents, use of N-methylpyrrolidone, acetone, dimethylformamide, chloroform or the like is preferable. These organic solvents are used alone or in combination of two or more. As a method of washing with an organic solvent, there is a method of immersing a PPS resin in an organic solvent, and if necessary, stirring or heating can be appropriately performed. There is no restriction | limiting in particular about the washing | cleaning temperature at the time of wash | cleaning PPS resin with an organic solvent, Arbitrary temperature of about normal temperature-about 300 degreeC can be selected. Although the cleaning efficiency tends to increase as the cleaning temperature increases, a sufficient effect is usually obtained at a cleaning temperature of room temperature to 150 ° C. The PPS resin that has been washed with an organic solvent is preferably washed several times with water or warm water in order to remove the remaining organic solvent.

  The following method can be illustrated as a specific method when the PPS resin is washed with hot water. That is, in order to express a preferable chemical modification effect of the PPS resin by hot water washing, the water used is preferably distilled water or deionized water. The operation of the hot water treatment is usually performed by charging a predetermined amount of PPS resin into a predetermined amount of water, and heating and stirring at normal pressure or in a pressure vessel. The ratio of the PPS resin to water is preferably larger, but usually a bath ratio of 200 g or less of PPS resin is selected for 1 liter of water.

  The following method can be illustrated as a specific method in the case of acid-treating PPS resin. That is, there is a method of immersing a PPS resin in an acid or an aqueous solution of an acid, and stirring or heating can be performed as necessary. The acid used is not particularly limited as long as it does not have an action of decomposing PPS resin, and is saturated with aliphatic monocarboxylic acid such as formic acid, acetic acid, propionic acid and butyric acid, and halo-substituted aliphatic such as chloroacetic acid and dichloroacetic acid. Aromatic carboxylic acids such as saturated carboxylic acid, benzoic acid, salicylic acid, dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, phthalic acid, fumaric acid, inorganic acidic compounds such as sulfuric acid, phosphoric acid, hydrochloric acid, carbonic acid, silicic acid, etc. Can be given. Of these, acetic acid and hydrochloric acid are more preferably used. In order to remove the remaining acid or salt from the acid-treated PPS resin, it is preferable to wash it with water or warm water several times. The water used for washing is preferably distilled water or deionized water in the sense that it does not impair the effect of the preferred chemical modification of the PPS resin by acid treatment.

  In the present invention, a conventionally known compatibilizing agent may be blended for the purpose of improving the compatibility of the copolymerized polyamide resin (A) and the PPS resin (B). Specific examples of these compatibilizers include organosilane compounds such as alkoxysilanes having at least one functional group selected from an epoxy group, an amino group, an isocyanate group, a hydroxyl group, a mercapto group, and a ureido group, Α-olefins such as ethylene and propylene and α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and crotonic acid, their esters, anhydrides, halides, sodium, potassium, magnesium, zinc, etc. Random, block, and modified copolymers such as graft copolymers with at least one compound selected from derivatives such as salts, α-olefins and glycidyl esters of α, β-unsaturated acids Epoxy group-containing olefin copolymers such as olefin copolymers and polyfunctional epoxy Shi compounds and the like, it can also be used at the same time two or more.

In the present invention, the blending ratio of the copolymerized polyamide resin (A) and the PPS resin (B) is 50 to 95% by weight of the copolymerized polyamide resin and 5 to 50% by weight of the PPS resin. When the PPS resin as the component (B) is less than 5% by weight, the effect of improving the heat resistance and antifreeze resistance is small, and when it exceeds 50% by weight, the impact resistance is significantly inferior.
The heat resistance referred to here is a bending test piece molded at a molding temperature of PPS resin melting point + 20 ° C., and the bending test piece is evaluated at a deflection temperature under load measured according to ASTM D638, preferably at 200 ° C. or higher. is there. When the deflection temperature under load is less than 200 ° C., the heat resistance is inferior, and therefore, it is not preferable because it cannot be used for parts that require heat resistance such as a radiator tank used in an automobile engine room.

  Antifreeze resistance as used herein refers to molding of ASTM No. 1 dumbbell piece at a molding temperature of PPS resin melting point + 20 ° C., and the tensile strength of the dumbbell piece and 130 ° C./1000 hours in a 50% long life coolant (LLC) aqueous solution. It is evaluated by the strength retention based on the tensile strength after the treatment, and is preferably 40% or more. When the strength retention is less than 40%, the antifreeze resistance is poor, and therefore, it is not preferable because it cannot be used for parts requiring antifreeze resistance such as a radiator tank used in an automobile engine room. The long life coolant (LLC) here is an antifreeze containing ethylene glycol as a main component.

  In order to obtain a high balance between antifreeze resistance and heat resistance, the polyamide resin composition of the present invention forms a continuous phase (matrix) as shown in FIG. It is preferable that the dispersed phase is formed (sea-island structure), and the PPS resin forming the dispersed phase has a dispersed morphology with an average particle diameter of 0.01 to 3 μm, more preferably 0.01 to 2. It is 5 μm, more preferably 0.5 to 2.5 μm. Here, the morphology of the present invention is not limited to the form of FIG. 1, and the shape of the PPS resin particles may be polygonal or substantially elliptical. When the dispersion of the PPS resin is in an agglomerated form and the average particle diameter is larger than 3 μm, the mechanical strength and impact resistance are lowered. On the other hand, when the average particle size is smaller than 0.01 μm, the effect of improving the heat resistance and antifreeze resistance is small. In the case of the morphology of the present invention, mechanical strength and impact resistance, heat resistance, and antifreeze resistance are particularly excellent.

  The average particle size referred to here means molding ASTM No. 1 dumbbell pieces at a molding temperature of PPS resin melting point + 20 ° C., and cutting a thin piece 0.1 μm or less (about 80 nm) from the center in the cross-sectional area direction of the dumbbell pieces. Then, with respect to the dispersed portions of 100 arbitrary PPS resins when observed with a transmission electron microscope (magnification: 10,000 times), first, the respective maximum diameter and minimum diameter were measured to obtain an average value, and then those It is the number average particle diameter for which the average value was obtained.

In this invention, in order to improve the impact property of a polyamide resin, it is preferable to contain (C) aliphatic polyamide resin. The (C) aliphatic polyamide used in the present invention is a substantially linear polyamide having —CH ₂ —, specifically, nylon 46, nylon 66, nylon 610, nylon 612, nylon 6, Nylon 11, nylon 12, nylon 66 and nylon 6 copolymer, nylon 66 and nylon 610 copolymer, nylon 66 and nylon 612 copolymer and the like may be mentioned, and two or more kinds may be blended. More preferred is nylon 6, nylon 66 or nylon 66/6 copolymer. The molecular weight of the aliphatic polyamide is not particularly limited and may be in a known molecular weight range, but preferably ηr is in the range of 1.5 to 7.0, particularly in the range of 2.0 to 6.0. Aliphatic polyamide resins are preferred. The content of the (C) aliphatic polyamide resin is preferably 5 to 50% by weight, more preferably 5 to 30% by weight of the total of the components (A) to (C). If the blending amount of the aliphatic polyamide is less than 5% by weight, the impact improving effect is small, and if the blending amount exceeds 50% by weight, the antifreeze resistance is inferior.

  In the present invention, it is preferable to blend (D) an inorganic filler in order to improve the mechanical strength of the polyamide resin composition. Although it does not specifically limit as (D) inorganic filler used by this invention, Fillers, such as fibrous form, plate shape, powder form, a granular form, can be used. Specifically, glass fibers, PAN-based and pitch-based carbon fibers, stainless steel fibers, metal fibers such as aluminum fibers and brass fibers, organic fibers such as aromatic polyamide fibers, gypsum fibers, ceramic fibers, asbestos fibers, zirconia fibers , Alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whisker, silicon nitride whisker, etc., whisker-like filler, wollastonite, sericite, kaolin, mica, clay, bentonite, Silicate silicates such as asbestos, talc and alumina silicate, swellable layered silicates such as montmorillonite and synthetic mica, metal compounds such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide and iron oxide, calcium carbonate, calcium carbonate , Magne carbonate Um, carbonates such as dolomite, calcium sulfate, sulfates such as barium sulfate, glass beads, ceramic beads, boron nitride, silicon carbide, and a non-fibrous fillers such as calcium phosphate and silica. In the above filler, PAN-based carbon fibers are preferably used when glass fibers and conductivity are required. The type of glass fiber is not particularly limited as long as it is generally used for reinforcing a resin, and can be selected from, for example, a long fiber type, a short fiber type chopped strand, a milled fiber, or the like. Moreover, said filler can also be used in combination of 2 or more types. In addition, the surface of the filler used in the present invention is a known coupling agent (for example, silane coupling agent, titanate coupling agent, etc.), other surface treatment agents, and swellable layered silicates. Pretreatment with organic onium ions is preferred in terms of obtaining better mechanical strength and antifreeze resistance. The glass fiber may be coated or bundled with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin.

  The blending amount of the (D) inorganic filler is preferably 0.5 to 100 parts by weight with respect to 100 parts by weight of the polyamide resin composition of the present invention. More preferably, it is 5 to 80 parts by weight. If the blending amount is less than 0.5 parts by weight, the strength is insufficient, which is not preferable. On the other hand, if the blending amount exceeds 100 parts by weight, the fluidity at the time of molding is impaired.

  In the composition of the present invention, other components such as antioxidants and heat stabilizers (hindered phenol-based, hydroquinone-based, phosphite-based and substituted products thereof), weather resistance, etc. are within the range not impairing the effects of the present invention. Agents (resorcinol, salicylate, benzotriazole, benzophenone, hindered amine, etc.), mold release agents and lubricants (montanic acid and its metal salts, esters, half esters, stearyl alcohol, stearamide, various bisamides, bisureas) And polyethylene wax, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black, etc.), dyes (eg, nigrosine), crystal nucleating agents (talc, silica, kaolin, clay, etc.), plasticizers (octyl p-oxybenzoate, N- Butylbenzenesulfonamide), antistatic (Alkyl sulfate type anionic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, betaine amphoteric antistatic agents, etc.), flame retardants (eg red phosphorus, melamine cyanurate, hydroxylation) Hydroxides such as magnesium and aluminum hydroxide, ammonium polyphosphate, brominated polystyrene, brominated polyphenylene ether, brominated polycarbonate, brominated epoxy resins or combinations of these brominated flame retardants with antimony trioxide), etc. The polymer can be added.

  The water-circulating member in the present invention is a so-called “heat system method” such as a radiator tank that is a component in an automobile engine room, floor heating that performs floor heating, or a road heating system that prevents freezing of road surfaces in cold regions. It is a member arranged in contact with an aqueous solution (antifreeze) containing hot water or a polyhydric alcohol such as ethylene glycol or propylene glycol, which is typified by a pipe-like pipe used in the above. Such polyhydric alcohols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,5-pentanediol, hexylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, Polyethylene glycol, polypropylene glycol, glycerin and the like can be mentioned, and all of them are effective. Among them, ethylene glycol and propylene glycol can be preferably used.

  The method for obtaining the polyamide resin composition of the present invention is not particularly limited, but in melt kneading, for example, when melt kneading with a twin screw extruder, polyamide resin and PPS resin are supplied from the main feeder, and the inorganic filler is used. Examples thereof include a method of feeding from the side feeder at the tip of the extruder and a method of melt-kneading the polyamide resin in advance and then melt-kneading with the inorganic filler. The extrusion temperature is usually selected from a temperature range 5 to 50 ° C. higher than the melting point of the polyamide resin or PPS resin, and the screw rotation speed is preferably 150 rpm or more, and more preferably 200 rpm or more for obtaining the morphology of the present invention. Is preferred.

  The water supply member of the present invention can be shaped by a known method, and the molding method is not limited, and injection molding, extrusion molding, blow molding, press molding and the like can be used. Among them, it is preferable to employ one method selected from injection molding, injection compression molding, and compression molding in terms of excellent productivity and industrial implementation of the present invention. The molding temperature is usually selected from a temperature range 5 to 50 ° C. higher than the melting point of the polyamide resin or the PPS resin, and is generally a single layer, but may be a multilayer by a two-color molding method. .

  The water-circulating member of the present invention can be preferably used for tanks, pipes, pump housings, valves, flanges and the like because of its excellent antifreeze resistance, and among them, it can be preferably used as a pipe.

  The hot water circulation device of the present invention refers to a device for adjusting the antifreeze liquid to 30 to 60 ° C. and circulating it through a pipe. The hot water circulation device of the present invention comprises a heat exchanger heated by a heat source, a storage tank that stores hot water, and a circulation pump that forcibly circulates hot water, and each is connected by a pipe to circulate hot water, thereby It is possible to maintain a constant temperature under the floor and under the road.

  In addition, for example, in a pipe of a hot water circulation device such as floor heating or road heating, an aqueous solution containing hot water or a polyhydric alcohol such as ethylene glycol is circulated, but the hot water circulation device of the present invention is It is preferable that an aqueous solution containing a polyhydric alcohol adjusted to 30 ° C. to 120 ° C. or water adjusted to 30 ° C. to 90 ° C. is passed. Since the aqueous solution containing polyhydric alcohol has an effect as an antifreeze, it can be suitably used as a hot water circulation device used in cold regions.

  Furthermore, the hot water circulation apparatus according to the present invention can be suitably used for a road heating system in which the pipe produced as described above is buried in the ground and the ground surface of the buried portion is asphalt-treated. .

Hereinafter, although an example is given and the present invention is explained in detail, the gist of the present invention is not limited only to the following examples.
(1) Measured according to standard methods below material strength.

Tensile strength and elongation: ASTM D638
Flexural modulus: ASTM D790
(2) Heat resistance The deflection temperature under load was measured according to ASTM D648.
(3) Antifreeze resistance The tensile strength and strength retention after treating ASTM No. 1 dumbbell pieces in a 50% aqueous solution of long life coolant (LLC) at 130 ° C./1000 hours were measured and used as a measure of antifreeze resistance.
(4) Morphology An ASTM No. 1 dumbbell piece is formed by injection molding under the conditions of a cylinder temperature of 300 ° C. and a mold temperature of 80 ° C. using an injection molding machine, and a thin piece of 0.1 μm or less is cut from the center. They were observed with a transmission electron microscope at a magnification of 10,000 times and evaluated as follows.
*: When a copolyamide resin forms a continuous phase as shown in FIG.
(5) Average Particle Size The average particle size of the PPS resin was measured using the image software “Scion Image” for the dispersed part of 100 arbitrary PPS resin particles in the injection-molded product observed at a magnification of 10,000 as in the above-described morphology observation. Using (Scion Corporation), the maximum diameter and the minimum diameter of each particle were measured to determine an average value, and then the number average value was determined.
(6) Appearance of water-circulating member As a water-circulating member, a pipe having an outer diameter of 17 mm, a wall thickness of 2 mm, and a length of 500 mm was formed by extrusion, and the appearance along the longitudinal direction was visually observed.
(7) Heat resistance of water-circulating member A welded wire mesh (wire mesh: 4 mmφ, 15 cm × 15 cm) on the roadbed is embedded, and an outer diameter of 17 mm and a wall thickness of 2 mm formed by extrusion as a water-circulating member thereon. After assembling the pipe, asphalt (dense particle size (13)) heated to 160 ° C. was cast to a thickness of 50 mm. Thereafter, asphalt pavement was dug up, and the heat resistance was evaluated by the appearance of the pipe (presence or absence of deformation or breakage).
(8) Antifreeze resistance of water-circulating member A pipe with an outer diameter of 17 mm, a wall thickness of 2 mm, and a length of 300 mm formed as a water-circulating member is immersed in a 50% aqueous solution of long life coolant (LLC) and treated at 130 ° C./1000 hours. The antifreeze resistance was evaluated based on the presence or absence of cracks on the pipe surface.

[Reference Example 1]
700 g of equimolar salt of sebacic acid and hexamethylene diamine, 300 g of equimolar salt of terephthalic acid and hexamethylene diamine, 8 g of benzoic acid and 250 ml of ion-exchanged water were charged into an autoclave having an internal volume of 3 liters and sufficiently purged with nitrogen. While stirring, the temperature was raised from room temperature to 220 ° C. over about 1 hour. Thereafter, while maintaining the pressure at 18 kg / cm ² , the temperature was raised to 260 ° C. over about 2 hours while removing water from the reaction system. Thereafter, the temperature was raised to 300 ° C. over about 2 hours while releasing the pressure, and the reaction was completed. Thereafter, stirring was stopped and the reaction mixture was taken out from the bottom of the autoclave at a differential pressure of 10 kg / cm ² to obtain a polymer having ηr = 2.3.

[Reference Example 2]
A polymer was prepared in the same manner as in Reference Example 1 except that 500 g of equimolar salt of sebacic acid and hexamethylenediamine, 500 g of equimolar salt of terephthalic acid and hexamethylenediamine, 8 g of benzoic acid and 250 ml of ion-exchanged water were used as starting materials. did. The obtained polymer had ηr of 2.45.

[Reference Example 3]
A polymer was prepared in the same manner as in Reference Example 1 except that 300 g of equimolar salt of sebacic acid and hexamethylenediamine, 700 g of equimolar salt of terephthalic acid and hexamethylenediamine, 8 g of benzoic acid and 250 ml of ion-exchanged water were used as starting materials. did. Ηr of the obtained polymer was 2.35.

[Reference Example 4]
A polymer was prepared in the same manner as in Reference Example 1 except that 900 g of equimolar salt of sebacic acid and hexamethylenediamine, 100 g of equimolar salt of terephthalic acid and hexamethylenediamine, 8 g of benzoic acid and 250 ml of ion-exchanged water were used as starting materials. did. Ηr of the obtained polymer was 2.50.

Polyamide resins and PPS used in Examples and Comparative Examples are as follows. Unless otherwise specified, polymerization was carried out and adjusted according to conventional methods.
<Polyamide resin>
(N6): Nylon 6 resin having a melting point of 225 ° C. and a relative viscosity of 2.80.
(N66): Nylon 66 resin <PPS resin> having a melting point of 265 ° C. and a relative viscosity of 2.70
(PPS-1): PPS resin having a melting point of 280 ° C., a melt flow rate (MFR) of 1000 g / 10 minutes (315 ° C., 5000 g load), and a weight average molecular weight (Mw) of 30000.
(PPS-2): PPS resin having a melting point of 280 ° C., MFR of 600 g / 10 minutes, and Mw of 38000.

Examples 1-12, Comparative Examples 1-10
When the copolymer polyamide resin and other resin are mixed as shown in Tables 1 and 2 and supplied from the main feeder of the TEX30 twin screw extruder manufactured by Nippon Steel Works, the inorganic filler is supplied in the middle of the cylinder. Melting and kneading were performed at a kneading temperature of 300 ° C. and a screw rotation speed of 200 rpm by a method of feeding using a side feeder. The obtained pellets were prepared and evaluated by the same method as in Example 1. The evaluation results are as shown in Tables 1 and 2.

  Here, GF in the table indicates glass fiber (fiber diameter 13 μm, 3 mm chopped strand, manufactured by Nippon Sheet Glass Co., Ltd.).

As is clear from comparison with Examples 1 to 12 and Comparative Examples 1 to 10,
A polyamide resin composition in which a polyphenylene sulfide resin is blended in a specific ratio with a copolymerized polyamide resin obtained by copolymerizing N610 and N6T in a specific ratio, and if necessary, an aliphatic polyamide and an inorganic filler are blended The resin composition of the present invention combines high mechanical strength and excellent heat resistance and good antifreeze resistance, and is suitable for use in water-based members.

It is a model figure of the morphology in which a copolymerized polyamide resin forms a continuous phase and a PPS resin is dispersed.

Explanation of symbols

1. 1. Copolymerized polyamide resin 2. PPS resin Inorganic filler

Claims (8)

(A1) 20 to 80% by weight of hexamethylene sebacamide units obtained from sebacic acid and hexamethylenediamine, (a2) 80% to 20% by weight of hexamethylene terephthalamide units obtained from terephthalic acid and hexamethylenediamine (A) Copolyamide resin 50 to 95% by weight and (B) Polyphenylene sulfide resin 5 to 50% by weight. The polyamide resin composition has a morphology in which (A) a copolymerized polyamide resin forms a continuous phase and (B) a polyphenylene sulfide resin is dispersed in the composition with an average particle size of 0.01 to 3 μm. The polyamide resin composition according to claim 1, wherein: The polyamide resin composition according to claim 1 or 2, comprising 95 to 50% by weight of the polyamide resin composition and 5 to 50% by weight of (C) an aliphatic polyamide resin. The polyamide resin composition according to claim 1, wherein 0.5 to 100 parts by weight of (D) inorganic filler is contained with respect to 100 parts by weight of the polyamide resin composition. A water member comprising the polyamide resin composition according to any one of claims 1 to 4. The water-around member according to claim 5, wherein the water-around member is formed by at least one method selected from injection molding, injection compression molding, and compression molding. The water-circulating member according to claim 5 or 6, wherein the water-circulating member is a pipe. An aqueous solution containing water or a polyhydric alcohol is passed through a conduit constituted by the pipe according to claim 7.

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