JP2003277605A - Resin composition for molded articles in contact with water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for molded articles and a molded article which are excellent in mechanical properties such as tensile strength and flexural modulus and which are excellent in heat aging resistance and hydrolysis resistance and which come into contact with water. Offer. SOLUTION: (A) 15 to 150 parts by weight of glass fiber, (C) 0.05 to 1.0 part by weight of phenolic heat stabilizer, and (D) based on 100 parts by weight of polyamide resin. A resin composition and a molded article containing a copper compound in an amount of 10 to 5000 ppm based on copper in the copper compound with respect to (A) and used for a molded article that comes into contact with water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded product which is excellent in tensile strength and flexural modulus and which is in contact with water and which is excellent in hydrolyzability, and a resin composition used therefor.

[0002]

2. Description of the Related Art Polyamide resins are utilized in various industrial fields by taking advantage of their excellent mechanical properties and heat resistance. Particularly in the vicinity of an automobile engine, a material having high reliability is required as a mechanical component. Therefore, a so-called reinforced polyamide resin in which mechanical properties are further improved by compositely strengthening glass fibers is preferably used. Among these parts, a polyamide resin material having excellent long-term heat resistance and chemical resistance is desired for parts that are likely to come into contact with the antifreeze liquid around the radiator and hot water. However, a polyamide resin material simply reinforced with glass fibers is sufficiently satisfactory in mechanical strength but insufficient in heat aging resistance and hydrolysis resistance. In order to improve these, various methods have been proposed so far.

For example, in order to improve antifreeze resistance, appearance and releasability, JP-A No. 11-166119 discloses:
A reinforced polyamide resin composition produced by kneading a raw material composed of a polyamide resin, a glass fiber, an azine dye and an aliphatic bisamide compound and / or a higher fatty acid metal salt with a glass fiber at the time when the polymer is melted is proposed. There is. However, in this proposal, although the hydrolysis resistance is excellent, the heat aging resistance is not sufficiently satisfactory.

Polyamide manufacturers have commercialized copper halides and materials in which copper acetate and halides are added at the same time for the purpose of improving heat aging resistance. Since the compound is liable to be eluted, there is a tendency that the action and effect on the heat-resistant aging property is less likely to be exhibited as compared with the usual molded product. As described above, there has been no method for improving the mechanical properties, the heat aging resistance and the hydrolysis resistance of the glass fiber reinforced polyamide resin at the same time, and a material capable of simultaneously satisfying such properties has been desired.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to tensile strength,
It is an object of the present invention to provide a resin composition and a molded product that are used in a molded product that is in contact with water and that has excellent mechanical properties such as flexural modulus, and further has excellent heat aging resistance and hydrolysis resistance. .

[0006]

As a result of intensive studies to solve the above problems, the present inventors have found that a copper compound and a phenolic stabilizer are added to a composition comprising a polyamide resin and glass fiber. It is possible to obtain a composition and a molded article that are used for molded articles that are in contact with water and that have excellent mechanical properties such as tensile strength and flexural modulus, and that also have excellent heat aging resistance and hydrolysis resistance. Find out that
The present invention has been completed.

That is, in the present invention, (1) 100 parts by weight of (A) polyamide resin and (B) glass fiber 15 to 1 are used.
50 parts by weight of (C) phenolic heat stabilizer is added in an amount of 0.05 to
A resin composition comprising 1.0 part by weight and (D) a copper compound in an amount of 10 to 5000 ppm based on (A), based on copper in the copper compound, and used in a molded product that comes into contact with water. (2) 15 to 150 parts by weight of (B) glass fiber, relative to 100 parts by weight of (A) polyamide resin,
Water comprising a resin composition containing (C) a phenolic heat stabilizer in an amount of 0.05 to 1.0 part by weight, and (D) a copper compound in an amount of 10 to 5,000 ppm relative to (A) based on copper in the copper compound. A molded product that comes into contact with. The present invention relates to a resin composition and a molded product used in a molded product that comes into contact with water according to the above (1) and (2).

The present invention will be described in detail below. A general polyamide can be used as the (A) polyamide resin according to the present invention. For example, polyamide 66 obtained by condensation polymerization of diamine and dicarboxylic acid, polyamide 610, polyamide 612, polyamide 6T (polyhexamethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide), obtained by ring-opening polymerization of lactam. Polyamide 6, polyamide 12, polyamide 11 obtained by self-polycondensation of ω-aminocarboxylic acid
At least one selected from the above, and / or a copolymer or blend of these polyamides can be used. Among the above-mentioned polyamides, polyamide 66, in terms of mechanical properties, heat resistance, crystallization temperature, moldability and appearance of molded products,
A homopolymer, a copolymer or a blend of polyamide 6, polyamide 610, polyamide 612 and polyamide 6I is preferable.

JIS of polyamide resin used in the present invention
According to K6810, a polyamide having a relative viscosity of 1.6 to 3.7 measured at 25 ° C. in a 98% sulfuric acid concentration of 1% is preferably used, and a more preferable relative viscosity is 2.0 to 3 .1. If the relative viscosity is less than 1.6, the toughness may be insufficient and the mechanical strength may be lowered depending on the molded product. If the relative viscosity exceeds 3.7, the molding process becomes difficult and the appearance may be deteriorated.

Further, in the polyamide resin of the present invention, the amino terminal group is preferably 20 to 200 milliequivalents per kg of the polyamide resin, and more preferably 30 to 60.
It is a milliequivalent. When the amino terminal group is less than 30 mm, it becomes difficult to form a polyamide layer grafted to the interface with the glass fiber, and the mechanical properties are likely to be deteriorated. It is difficult, and even if it is obtained, it has a low molecular weight, resulting in insufficient mechanical properties.

Next, the glass fiber which is the component (B) used in the present invention will be described. Any glass fiber may be used as long as it is used as a reinforcing material for the polyamide resin, but from the viewpoint of handleability when the glass fiber is melt-mixed with the polyamide resin, the glass fiber length 1 to
Chopped type short fibers having a diameter of 10 mm and an average glass fiber diameter of 8 to 25 μm are preferable. Particularly preferable glass fiber shape is a glass fiber having a fiber length of 2 to 7 mm and an average fiber diameter of 8 to 15 μm from the viewpoint of reinforcing effect and glass fiber dispersibility. Glass fibers with an average diameter of less than 8 μm are difficult to bundle, and the fiber length may be reduced due to processing steps such as melt-kneading, which may adversely affect mechanical properties. However, the same glass fiber concentration may reduce mechanical properties.

The glass fiber contained in the polyamide resin preferably has an aspect ratio of 10 to 50, more preferably 20 to 40. When the aspect ratio of the contained glass fibers is less than 10, the mechanical properties are not improved so much, and when it exceeds 50, the glass fibers are likely to appear on the surface of the molded product and the appearance of the molded product may be deteriorated. The aspect ratio of the glass fiber referred to herein is a value obtained by dividing the weight average length of the glass fiber by the number average fiber diameter. The diameter of the glass fiber contained in the polyamide is almost equal to the diameter of the glass fiber raw material before mixing with the polyamide.

Further, the glass fiber is one which has been surface-treated with a sizing agent for polyamide resin (which contains a so-called sizing-purpose sizing component and a surface-treating component intended for adhesion between the polyamide resin). preferable. As the sizing agent used here, those having a main component of a copolymer of maleic anhydride and an unsaturated monomer, a silane coupling agent and / or an acrylic acid copolymer and / or a urethane polymer. However, especially from the effect of improving strength, rigidity, vibration fatigue characteristics and hydrolysis resistance, a copolymer of maleic anhydride and an unsaturated monomer and an amino group-containing silane coupling agent are the main constituent components. The most preferable one is.

Specific examples of the copolymer of maleic anhydride and an unsaturated monomer constituting the sizing agent include styrene and α-
Methylstyrene, butadiene, isoprene, chloroprene, 2,3-dichlorobutadiene, 1,3-pentadiene, a copolymer of an unsaturated monomer such as cyclooctadiene and maleic anhydride, and among them, butadiene,
A copolymer of styrene and maleic anhydride is particularly preferred. Further, two or more of these monomers may be used in combination, and for example, a mixture of a maleic anhydride / butadiene copolymer and a maleic anhydride / styrene copolymer may be used. I don't care. The above-mentioned copolymer of maleic anhydride and unsaturated monomer has an average molecular weight of 2,0.
It is preferably 00 or more. The ratio of maleic anhydride and unsaturated monomer is not particularly limited. Further, in addition to the maleic anhydride copolymer, an acrylic acid copolymer or a urethane polymer may be used in combination without any problem.

As the silane coupling agent which is another component constituting the sizing agent of the present invention, any silane coupling agent usually used for surface treatment of glass fibers can be used. Specifically, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane , N-β (aminoethyl)
Examples include aminosilane coupling agents such as γ-aminopropyltriethoxysilane.

Further, epoxysilane coupling agents such as γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane; γ-methacryloxypropylmethyl Methacryloxysilane coupling agents such as dimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, Examples thereof include vinylsilane-based coupling agents such as vinyltris (β-methoxyethoxy) silane.

These coupling agents can also be used in combination of two or more kinds. Among these, aminosilane coupling agents are most preferable because of their affinity with polyamide resins, and among them, γ-aminopropyltriethoxysilane and N-β (aminoethyl) γ-aminopropyltriethoxysilane are most preferable. The ratio of the maleic anhydride copolymer to the silane coupling agent is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the former which gives a relatively good balance of physical properties. Usually, a maleic anhydride copolymer and a silane coupling agent are mixed in a water solvent and used as a sizing agent, but if necessary, a surfactant, a lubricant, a softening agent, an antistatic agent, etc. may be added. Is also good.

The sizing agent is a process of processing glass into a fiber,
Alternatively, it is used by adhering it to the glass fiber surface in a step after processing, and when it is dried, a coating film composed of the copolymer and the coupling agent is formed on the glass fiber surface. At this time, the final adhesion amount after drying the sizing agent is 1 glass fiber.
It is preferably in the range of 0.1 to 2 parts by weight per 00 parts by weight. If the adhesion amount is 0.1 parts by weight or less, the sizing property of the glass fiber becomes insufficient, and when blending with the polyamide resin,
The so-called pills formed by the intertwining of glass fibers,
The physical properties of the glass fiber reinforced polyamide resin composition may be significantly reduced. On the other hand, when the adhered amount is 2 parts by weight or more, the glass fibers are strongly bundled together, so that the fiber bundle is observed in the molded product and the appearance of the molded product is liable to be poor. A more preferable amount of the sizing agent attached is in the range of 0.2 to 1.0 part by weight per 100 parts by weight of glass fiber. Here, the amount of the sizing agent attached is measured as the ignition loss after the glass fiber is burned for 60 minutes, and is determined according to JIS R3420.

The amount of the glass fiber (B) used in the present invention is 15 to 15 with respect to 100 parts by weight of the polyamide resin.
It is 0 part by weight, and 30 to 50 parts by weight is preferable from the viewpoints of moldability and surface appearance of the molded product. If the content of the glass fiber is less than 15 parts by weight, the strength, rigidity and heat aging resistance will be insufficient, and if it exceeds 150 parts by weight, moldability and appearance will be significantly deteriorated. Further, as the phenolic heat stabilizer which is the component (C) of the present invention, a hindered phenolic stabilizer can be preferably used, and for example, N, N ′ hexamethylenebis3- (3,5-di. Tertiary-butyl-4-hydroxyphenyl) -propionate, triethylene glycol bis-3- (3-tertiary-butyl-4-hydroxy-5-methyl-phenyl) propionate, 1,6-hexanediol-bis- [3- (3,
5-di-tertiary-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3. 5-triazine can be illustrated.

Further, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and 2,2-thio-diethylenebis [3- (3,5-di-]. t-Butyl-4-hydroxyphenyl) propionate, octadecyl-3- (3,5
-Di-t-butyl-4hydroxyphenyl) propionate, 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5
-Trimethyl-2,4,6-tris (3,5-di-t-
Butyl-4-hydroxybenzyl) benzene etc. can be illustrated. The blending ratio of the component (C) of the present invention is 0.05 to 1.0 parts by weight with respect to 100 parts by weight of the polyamide resin, and the blending amount of the component (C) is less than 0.05 parts by weight, The effect of the present invention cannot be obtained, and when it exceeds 1.0 part by weight, bleeding occurs during molding, and deterioration of the appearance of the molded product and contamination of the mold are likely to occur.

The copper compound which is the component (D) of the present invention includes, for example, copper chloride, copper bromide, copper fluoride, copper iodide, copper thiocyanate, copper nitrate and acetic acid. Copper, naphthene copper, copper caprate, copper laurate, copper stearate, copper acetylacetone, copper (I) oxide, copper (II) oxide and the like can be mentioned. Particularly preferred in the present invention is copper iodide or the like. Copper halide and copper acetate. The amount of the copper compound added is 10 to 5000 ppm, and particularly preferably 50 to 2000 ppm, based on the copper in the copper compound, based on the polyamide resin. Addition amount is 10pp
If it is less than m, it becomes difficult to sufficiently exert the effect of improving the heat aging resistance, and the addition amount is 5000 p.
If it exceeds pm, the effect of improving the heat aging resistance is saturated, and the effect of increasing the amount of addition is not obtained, and conversely, for example, corrosion of metals such as polymerization reactors, extruders, molding machines, etc.,
Corrosion of the metal inserted into the molded product easily occurs. Further, in the present invention, the copper compound is more preferably used in combination with an inorganic or organic halide.

Examples of such inorganic or organic halides include alkali metal or alkaline earth metal halides and ammonium halides, and organic compound quaternary ammonium halides or alkyl halides and allyl halides. Specifically, sodium bromide, sodium iodide, potassium bromide, potassium iodide, calcium chloride, ammonium iodide, stearyltriethylammonium bromide, benzyltriethylammonium iodide and the like can be illustrated. Among these, iodine compounds are preferable, and more preferable iodine compounds include, for example, potassium iodide,
Magnesium iodide, ammonium iodide and the like are preferable. The addition amount of these is 0.005 to 1 part by weight, preferably 100 parts by weight of the polyamide resin (A),
0.01 to 0.8 parts by weight is preferable.

These heat stable formulations may be carried out at any step during polyamide manufacture. For example, a copper compound containing copper acetate and copper iodide as a constituent component may be added to a monomer, and then polymerization may be performed, or after the polymer is obtained by the polymerization, in a processing step such as an extruder or a molding machine. It may be added in the molten polyamide.
Alternatively, it may be directly mixed with the polymer pellets and then subjected to a molding step.

The glass fiber reinforced resin composition of the present invention can be used in molding processes such as injection molding, extrusion molding, blow molding and press molding. In addition, various additives are added to the resin composition of the present invention as desired, such as heat stabilizers for polyamides such as phosphorus compounds, oxidative deterioration of hindered phenols and hindered amines, etc. within a range not impairing the object of the present invention. Inhibitors, light stabilizers such as manganese compounds, nucleating agents such as talc and boron nitride, mineral fillers such as calcium carbonate, wollastonite, kaolin, calcined kaolin and mica, carbon black, titanium oxide, and phthalocyanine dyes Other colorants, plasticizers, antistatic agents, other thermoplastic resins, etc. can be added.

[0025]

〔raw materials〕

[1] Polyamide Resin PA1: Polyamide 66, Relative Viscosity 2.5, Number of Amino End Groups 45 mEq / kg, Cu Concentration 100 ppm, CuI / KI (Iodine is added by 20 times mol relative to copper) PA2: Polyamide 66/6 Copolymer (The ratio of polyamide 6 is 5% by weight), relative viscosity 2.5, amino terminal group number 4
5 meq / kg, Cu concentration 100 ppm, CuI / KI (adding 20 times mole iodine to copper) PA3: Polyamide 66 / 6I (ratio of polyamide 6I is 5% by weight; polyamide 6I is polyhexamethylene isophthalamide) , Relative viscosity 2.0, amino end group 60 meq / kg, Cu concentration 100 ppm, CuI / KI (iodine to copper 2
PA4: Polyamide 66, relative viscosity 2.5, amino terminal group 50 meq / kg [2] Glass fiber Asahi Fiber Glass Co., Ltd .; CS03JAFT756K25 [3] Phenolic stabilizer PH1: Ciba Specialty Chemicals Co. Gender; Irga
nox1098 PH2: Yoshitomi Pharmaceutical Co., Ltd .; Yoshinox BB [4] Copper compound Cu1: Wako Pure Chemical Industries; CuI / KI (added during polyamide polymerization) Cu2: Bruggemann Product; Bruggolen H321 (added during melt kneading)

[Preparation of Test Pieces] Preparation of Tensile Strength Test Pieces and Bending Test Pieces Using an injection molding machine (PS40E made by NISSEI PLASTIC CO., LTD.), The mold temperature was 80 ° C., ASTM D638 TYPE I and length 5 inches × width 0 A 0.5 inch x 1/8 thick specimen was molded. Preparation of Aging Test Specimens A JIS No. 3 dumbbell (thickness: 3 mm) was molded at a mold temperature of 80 ° C. using an injection molding machine (PS40E made by NISSEI RESIN).

[Measurement Method] (I) Tensile Strength According to ASTM D638, the test piece was measured with a tensile tester (manufactured by Toyo Seiki: UTM25) at 23 ° C. and a crosshead speed of 5 mm / min. (II) Flexural Modulus According to ASTM D790, the test piece was measured by a tensile tester (manufactured by Toyo Seiki: UTM25) under conditions of 23 ° C., crosshead speed 5 mm / min, and span 50 mm. (III) Aging test after extraction with hot water 2 L of distilled water was weighed in an autoclave (content: 3 L),
After immersing JIS No. 3 dumbbell pieces, seal the lid and keep at 130 ° C.
The whole autoclave was immersed in the oil bath for 24 hours. After cooling, the test piece was taken out, the taken-out test piece was allowed to stand in oven air at 200 ° C. for 1000 hours, and after cooling, a tensile test was performed according to the method described in the above (I) Tensile strength. The distance between the cross heads at this time was set to 50 mm, a test was conducted, and the retention rate was calculated when the result of the tensile test before treatment was 100%.

(IV) Bleed-out test When the above-mentioned aging test piece was produced, the presence or absence of mold contamination after 50 shots was examined. (V) Copper Deposition Test 200 g of the melt-mixed composition pellets shown in Table 1 or Table 2 were placed in an SUS autoclave (internal volume: 3 L), and cooled 3 hours after the internal temperature reached 290 ° C. Then, the resin of which the pellet was melted was taken out, and the quantitative analysis of copper element was carried out by the ICP method. At that time, if the copper concentration holds 80% or more of the initial pellet, ○, 8
Those less than 0% were evaluated as x.

[0029]

[Examples 1 to 7, 9, 10] TEM3 manufactured by Toshiba Machine Co., Ltd.
Cylinder set temperature 290 using 5BS, twin screw extruder
℃, screw rotation speed 300 rpm, total feed amount 50 kg / hr, the top feed hole was fed with a mixed raw material other than glass fiber, and the glass fiber was fed into the polyamide resin melted from the side feed hole at the ratio shown in Table 1. After cooling the strands extruded from the spinning holes, the strands were cut into pellets having a length of 3 mm and a diameter of 3 mm and dried to obtain glass fiber reinforced polyamide resin composition pellets. The pellets thus obtained are subjected to the above-mentioned method at a cylinder temperature of 290 ° C.
Molded under the conditions of and evaluated. The results are shown in Table 1.

[0030]

Example 8 PA4 containing no copper was used as the polyamide, and Bruggolen H321 was mixed as the auxiliary raw material other than the PA4 pellets and the glass fiber during the melt mixing so that the copper concentration was the ratio shown in Table 1. Melt mixing, molding and evaluation were carried out in the same manner as in Example 1.

[0031]

[Comparative Examples 1 to 4] TEM35BS, 2 manufactured by Toshiba Machine Co., Ltd.
Cylinder set temperature 290 ℃ using screw extruder, screw rotation speed 300 rpm, total feed amount 50 kg
/ Hr mixed material other than glass fiber is supplied to the top feed hole, glass fiber is supplied to the polyamide resin melted from the side feed hole in the ratio of Table 2, and the strand extruded from the hole is cooled. It was cut into pellets having a length of 3 mm and a diameter of 3 mm and dried to obtain glass fiber reinforced polyamide resin composition pellets. The obtained pellets were molded and evaluated under the conditions of a cylinder temperature of 290 ° C. by the above method. The results are shown in Table 2.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

Industrial Applicability The resin composition of the present invention has excellent mechanical properties such as tensile strength and flexural modulus, and has improved heat aging resistance and hydrolysis resistance. In particular, engine covers that require strict reliability,
It can be suitably used for automobile underhood parts such as radiator tanks, car heater tanks, water valves, water pumps and radiator pipes.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4F071 AA54 AA54X AB15 AB18                       AB22 AB23 AB28 AC07 AC09                       AC11 AD01 AD07 AE05 AE17                       AF01 AF14 AF45 AH07 AH17                       BA01 BB05 BB06 BC07                 4J002 CL011 CL031 CL051 DD078                       DE098 DF038 DL006 EE048                       EG018 EG088 EJ027 EJ037                       EJ047 EJ067 EU187 EW127                       FA046 FB096 FB266 FD016                       FD067 FD208 GM00 GN00

Claims (2)

[Claims] 1. To 100 parts by weight of (A) polyamide resin, (B) 15 to 150 parts by weight of glass fiber, (C) 0.05 to 1.0 part by weight of phenolic heat stabilizer, and (D) ) A resin composition comprising a copper compound in an amount of 10 to 5,000 ppm relative to (A) based on copper in the copper compound and used in a molded product that is in contact with water. 2. To 100 parts by weight of (A) polyamide resin, (B) 15 to 150 parts by weight of glass fiber, (C) 0.05 to 1.0 part by weight of phenolic heat stabilizer, and (D) ) A molded article which is in contact with water and which comprises a resin composition containing a copper compound in an amount of 10 to 5000 ppm based on (A) based on copper in the copper compound.