JP2017095542A - Molded product having weld - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded product having a through hole being fixing means and a weld in contact with the through hole which can suppress cracking that particularly easily occurs and is excellent in weld toughness.SOLUTION: A molded product contains a polyamide resin (A) and a rubbery polymer (B) having at least one reactive functional group selected from the group consisting of an epoxy group, an acid anhydride group, an amino group, a carboxyl group, a carboxyl metal salt and an oxazoline group; is a molded product formed of a thermoplastic resin composition having specific morphology in electron microscope observation; and has a through hole being fixing means and a weld in contact with the through hole.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a molded article comprising a thermoplastic resin composition containing a polyamide resin and a rubbery polymer having a reactive functional group, and having a weld in contact with a through hole as a fixing means.

  Polyamide resins are widely used in automobile / vehicle-related parts, materials / building materials parts, sporting goods, electrical / electronic parts, etc. because of their excellent mechanical properties, heat resistance, and chemical resistance. In these applications, the shape of the molded product is complicated with modularization and weight reduction, and a molded product having a weld is used. Generally, welds in injection molding occur at a site where a molten resin flow injected into a mold cavity branches and merges. In such welds, although the molten resin merges and is fused, the resin may not be uniformly mixed, and the mechanical properties tend to be lower than that of the non-weld. In particular, in recent years, in addition to downsizing and thinning, the shape of the molded product is further complicated. In particular, when molding a molded product with a through-hole as a fixing means for fastening or fitting with other parts by injection molding, avoid the occurrence of welds because the molten resin flow branches and merges in the vicinity of the through-hole. However, there is a problem that cracks frequently occur starting from the weld. Possible methods for suppressing cracks that originate from welds include methods that do not generate welds through post-processing of through-holes, and methods that suppress cracks by increasing the thickness or changing the shape of molded products. Therefore, a material excellent in weld toughness is required.

  Regarding a technique for improving weld strength, for example, a thermoplastic resin composition comprising a polyamide resin, a modified polyolefin resin, and an unmodified polyolefin resin, wherein the thermoplastic resin composition has an average dispersed particle size of 20 μm or less, and a surfactant. A resin molded body (for example, see Patent Document 1), a polyamide, a resin mixture obtained by melt-mixing a polyolefin partially or entirely modified with an acid anhydride, and a weld comprising a higher aliphatic carboxylic acid metal salt A resin composition with improved strength has been proposed (see, for example, Patent Document 2).

  On the other hand, for a polyamide resin composition containing a polyamide resin and a modified polyolefin resin, for example, a thermoplastic resin composition containing (A) a thermoplastic resin and (B) a resin having a reactive functional group, In the morphology of the resin composition observed by a line tomography method, one of (A) or (B) forms a continuous phase, the other forms a dispersed phase, and the dispersed phase contains the continuous phase component. Thermoplastic resin in which a three-dimensional connection structure Cs is formed and the proportion of the area of the connection structure Cs in the cross section of the dispersion phase Dp having an average particle diameter of 1000 nm or less is 10% or more. Composition (for example, refer patent document 3).

JP-A-5-43794 JP-A-6-136259 JP 2007-254567 A

  Although the resin molded body and the resin composition described in Patent Documents 1 and 2 can improve the weld strength, the weld toughness is low. In particular, the resin molded body and the resin composition have a through hole as a fixing means and a weld in contact with the through hole. When applied to a molded product, there is a problem that cracks starting from welds are likely to occur. On the other hand, Patent Document 3 does not have a concept of applying a thermoplastic resin composition having a specific morphology to a molded product having a through hole as a fixing means and a weld in contact with the through hole, and weld toughness is also considered. Not.

  In view of the above circumstances, the present invention provides a molded article with excellent weld toughness that can suppress cracks that are particularly likely to occur in a molded article having a through hole as a fixing means and a weld in contact with the through hole. There is to do.

The present invention provides a thermoplastic resin composition having a specific morphology, including a polyamide resin and a rubbery polymer having a reactive functional group, into a molded product having a through hole as a fixing means and a weld in contact with the through hole. By using it, it has excellent toughness against post-processing stresses such as fastening and fitting with other parts and deformation of welds, and suppresses cracks originating from welds that are particularly likely to occur in such molded products. It was made by finding out that it can do. That is, the present invention is as follows.
(1) Rubber resin having polyamide resin (A) and at least one reactive functional group selected from the group consisting of epoxy group, acid anhydride group, amino group, carboxyl group, carboxyl metal salt and oxazoline group In the electron microscope observation, the polyamide resin (A) forms a continuous phase (α), the rubbery polymer (B) having the reactive functional group forms a dispersed phase (β), In addition, the dispersed phase (β) contains fine particles having a particle diameter of 1 to 100 nm made of a compound formed by the reaction of the polyamide resin (A) and the rubbery polymer (B) having a reactive functional group, and the dispersed phase (β ) Is a molded article made of a thermoplastic resin composition having a morphology in which the area occupied by the fine particles is 10% or more, and is in contact with the through hole as a fixing means and the through hole Molded article having a Eldo.
(2) The ratio (L / T) of the length (L [mm]) of the weld contacting the through hole to the thickness (T [mm]) of the molded product in the weld is 0.1 to 100 (1) Articles described in 1.
(3) The method for producing a molded article according to (1) or (2), wherein the thermoplastic resin composition is injection-molded.

  ADVANTAGE OF THE INVENTION According to this invention, the molded article excellent in weld toughness which can suppress the crack which tends to occur especially in the molded article which has the through hole which is a fixing means, and the weld which contacts a through hole can be provided.

It is the schematic which shows the one aspect | mode of the molded article which has the through hole which is a fixing means, and the weld which touches a through hole.

  The molded article of the present invention comprises a thermoplastic resin composition to be described later, and has a through hole that is a fixing means (hereinafter sometimes simply referred to as “through hole”) and a weld that is in contact with the through hole. And The through hole which is a fixing means refers to a through hole used for fixing to other components by post-processing such as fastening or fitting, and examples thereof include a screw hole and a metal insertion hole. When a molded product having a through hole is formed by injection molding, the thermoplastic resin composition flow melted in the vicinity of the through hole branches and merges, so that a weld that contacts the through hole is generated. Here, the weld in the present invention refers to a portion where the joining angle θ at the joining portion of the thermoplastic resin composition is 150 ° or less. Note that the merging angle θ is an angle formed by a perpendicular to each thermoplastic resin composition stream in the thermoplastic resin composition merging portion. When the merging angle is 0 °, the branched thermoplastic resin composition stream is merged from the front. When the merge angle is 180 °, it means that the branched thermoplastic resin composition streams do not merge. In the present invention, the term “weld is in contact with the through hole” means that the distance between the weld end on the through hole side and the through hole is 5% or less of the weld length (L) described later. When the distance between the weld hole on the through hole side and the through hole is 0, the effect of the present invention is more remarkably exhibited. Such weld tends to be a starting point of cracking, but in the present invention, by using a specific thermoplastic resin composition to be described later, a specific use of a molded product having a through hole and a weld in contact with the through hole. The weld toughness can be improved and cracking can be suppressed. Hereinafter, a molded product having a through hole and a weld contacting the through hole may be simply referred to as a “molded product”.

  FIG. 1 is a schematic view showing one embodiment of a molded product having a through hole and a weld contacting the through hole. In FIG. 1, 1 is a molded product having a through hole and a weld in contact with the through hole, 2 is a gate, 3 is a weld, and 4 is a through hole.

  In the molded product of the present invention, the ratio (L / T) of the weld length (L [mm]) in contact with the through hole to the thickness (T [mm]) of the molded product in the weld is 0.1 to 100. preferable. By setting L / T to 0.1 or more, the length of the weld is appropriately secured, the thickness of the molded product is moderately suppressed, the flow distance is shortened, and the cooling during the flow of the molten resin is suppressed. Therefore, the weld strength and weld toughness can be further improved. On the other hand, by setting L / T to 100 or less, the length of the weld can be moderately suppressed and the thickness of the molded product can be appropriately secured, so that the weld toughness can be further improved.

  L / T can be adjusted to a desired range by, for example, the thickness of the molded product, the shape of the molded product such as the position of the through hole, and the molding conditions such as the gate position and the number of gates.

  Examples of the molded product having a through hole as a fixing means and a weld in contact with the through hole include an adjuster plate and a cage clip.

  Next, the thermoplastic resin composition constituting the molded article of the present invention will be described. The thermoplastic resin composition used in the present invention includes a polyamide resin (A) and a rubbery polymer (B) having a reactive functional group. By including the rubbery polymer (B) having a reactive functional group together with the polyamide resin (A) excellent in heat resistance and strength, the tensile elongation at break and the impact strength can be improved.

  The polyamide resin used in the present invention is a resin composed of a polymer having an amide bond, and is mainly composed of amino acids, lactams or diamines and dicarboxylic acids. Representative examples of the raw materials include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, tetramethylenediamine, penta Methylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5 -Aliphatic diamines such as methylnonamethylenediamine, aromatic diamines such as metaxylylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1- Ami No-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane , Alicyclic diamines such as bis (aminopropyl) piperazine and aminoethylpiperazine, aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid Acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid and other aromatic dicarboxylic acids, 1,2-cyclohexane Dicarboxylic acid, 1,4-cyclohexa An alicyclic dicarboxylic acids such as dicarboxylic acid. In the present invention, two or more polyamide homopolymers or copolymers derived from these raw materials may be used in combination.

  In the present invention, particularly useful polyamide resins are polyamide resins having a crystal melting temperature of 150 ° C. or higher. Such polyamide resin is excellent in heat resistance and strength. Specific examples of polyamide resins having a crystal melting temperature of 150 ° C. or higher include polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polypentamethylene adipamide (polyamide 56), poly Tetramethylene adipamide (polyamide 46), polyhexamethylene sebacamide (polyamide 610), polypentamethylene sebacamide (polyamide 510), polytetramethylene sebacamide (polyamide 410), polyhexamethylene dodecamide (polyamide) 612), polyundecanamide (polyamide 11), polydodecanamide (polyamide 12), polycaproamide / polyhexamethylene adipamide copolymer (polyamide 6/66), polycaproamide / polyhexamethylene terephthalamide copolymer (Polyamide 6 / 6T), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (polyamide 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I), polyhexamethylene Adipamide / polyhexamethylene isophthalamide / polycaproamide copolymer (polyamide 66 / 6I / 6), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polyhexamethylene terephthalamide / polydecane Amide copolymer (polyamide 6T / 12), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6 / 6T / 6I), polyxylylene adipamide (polyamide XD6), polyhexamethylene terephthalamide / poly-2-methylpentamethylene terephthalamide copolymer (polyamide 6T / M5T), polyhexamethylene terephthalamide / polypentamethylene terephthalate Amide copolymer (polyamide 6T / 5T), polypentamethylene terephthalamide / polypentamethylene adipamide copolymer (5T / 56), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide (polyamide 10T) and these A copolymer etc. are mentioned.

  Particularly preferred are polyamide 6, polyamide 66, polyamide 56, polyamide 610, polyamide 510, polyamide 410, polyamide 612, polyamide 11, polyamide 12, polyamide 6/66, polyamide 66 / 6T, polyamide 6T / 6I, polyamide 66. / 6I / 6, polyamide 6T / 5T, polyamide 10T, and the like.

  It is practically preferable to use two or more of these polyamide resins depending on the required properties such as moldability, heat resistance, toughness, and surface properties. Among these, polyamide 6, polyamide 66, polyamide 610, More preferred are polyamide 11, polyamide 12, polyamide 66 / 6T, and polyamide 10T.

The terminal group concentration of the polyamide resin is not particularly limited, but those having a terminal amino group concentration of 1.5 × 10 ⁻⁵ mol / g or more are reactive with the rubbery polymer having a reactive functional group. In terms of surface. The terminal amino group concentration here can be measured by dissolving a polyamide resin in an 85% phenol-ethanol solution, using thymol blue as an indicator, and titrating with an aqueous hydrochloric acid solution.

  There is no restriction | limiting in particular in the polymerization degree of a polyamide resin, The range of 1.5-7.0 is preferable as relative viscosity measured at 25 degreeC in the 98-% concentrated sulfuric acid solution with a resin concentration of 0.01 g / ml. If the relative viscosity is 1.5 or more, the weld toughness can be further improved. 1.8 or more is more preferable. On the other hand, if the relative viscosity is 7.0 or less, the moldability can be improved. 5.0 or less is more preferable.

  In the present invention, the rubbery polymer (B) having a reactive functional group is at least one reaction selected from the group consisting of an epoxy group, an acid anhydride group, an amino group, a carboxyl group, a carboxyl metal salt, and an oxazoline group. Have a functional group. Hereinafter, the rubbery polymer having such a reactive functional group may be simply referred to as “rubbery polymer having a reactive functional group”. In particular, epoxy groups, acid anhydride groups, and carboxyl metal salts are preferably used because of their high reactivity and low side reactions such as decomposition and crosslinking.

  As the acid anhydride constituting the acid anhydride group, maleic anhydride and itaconic anhydride are preferably used. When the acid anhydride group is introduced into the rubbery polymer, the method can be carried out by a generally known technique and is not particularly limited. For example, the acid anhydride group and the raw material for the rubbery polymer can be used. A method of copolymerizing with a monomer, a method of grafting an acid anhydride onto a rubber polymer, and the like can be used.

  In addition, when the epoxy group is introduced into the rubbery polymer, the method can be carried out by a generally known technique and is not particularly limited. For example, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, itacon A method of copolymerizing a vinyl monomer having an epoxy group, such as a glycidyl ester compound of an α, β-unsaturated acid such as glycidyl acid, with a monomer which is a raw material of a rubber polymer, polymerization initiation having an epoxy group A method of polymerizing a rubbery polymer using an agent or a chain transfer agent, a method of grafting an epoxy compound onto a rubbery polymer, or the like can be used.

  When the amino group is introduced into the rubbery polymer, the method can be carried out by a generally known technique and is not particularly limited. For example, the amino compound and the monomer that is a raw material of the rubbery polymer And a method of grafting an amino group onto a rubbery polymer.

  When the carboxyl group is introduced into the rubbery polymer, the method can be carried out by a generally known technique, and is not particularly limited. For example, an unsaturated carboxylic acid monomer having a carboxyl group is added to the rubbery polymer. A method of copolymerizing with a monomer that is a raw material of the polymer can be used. Specific examples of the unsaturated carboxylic acid include (meth) acrylic acid.

  A carboxyl metal salt in which a part of the carboxyl group is a metal salt is also effective as a reactive functional group, and examples thereof include (meth) acrylic acid metal salts. Although the metal of a metal salt is not specifically limited, Preferably, alkali metals, such as sodium, alkaline-earth metals, such as magnesium, zinc etc. are mentioned.

  Further, when the oxazoline group is introduced into the rubbery polymer, the method can be carried out by a generally known technique and is not particularly limited. For example, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, For example, a method of copolymerizing a vinyl monomer having an oxazoline group such as 2-acryloyl-oxazoline and 2-styryl-oxazoline with a monomer which is a raw material of the rubber polymer can be used.

  In the present invention, the rubbery polymer of the rubbery polymer having a reactive functional group generally contains a polymer having a glass transition temperature lower than room temperature, and a part of the intermolecular molecule is a covalent bond, an ionic bond, It refers to polymers that are constrained to each other by van der Waals force, entanglement, and the like. For example, polybutadiene, polyisoprene, styrene-butadiene random copolymer and block copolymer, hydrogenated product of the block copolymer, acrylonitrile-butadiene copolymer, diene rubber such as butadiene-isoprene copolymer, Random copolymer and block copolymer of ethylene-propylene, random copolymer and block copolymer of ethylene-butene, copolymer of ethylene and α-olefin having 5 or more carbon atoms, ethylene-unsaturated carboxylic acid Preferred examples include ester copolymers.

  Among these, from the viewpoint of compatibility with the polyamide resin, an ethylene-unsaturated carboxylic acid ester copolymer is preferably used. The unsaturated carboxylic acid ester in the ethylene-unsaturated carboxylic acid ester copolymer is preferably a (meth) acrylic acid ester, more preferably an ester of (meth) acrylic acid and an alcohol. Specific examples of unsaturated carboxylic acid esters include (meth) acrylic acid such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylate-2-ethylhexyl, stearyl (meth) acrylate Examples include esters. The weight ratio of the ethylene component to the unsaturated carboxylic acid ester component in the ethylene-unsaturated carboxylic acid ester copolymer is not particularly limited, but is preferably 90/10 to 10/90, more preferably 85/15 to 15 / A range of 85. The number average molecular weight of the ethylene-unsaturated carboxylic acid ester copolymer is not particularly limited, but is preferably in the range of 1000 to 70000 from the viewpoint of fluidity and mechanical properties.

  The number of functional groups per molecular chain in the rubbery polymer having a reactive functional group is not particularly limited, but usually 1 to 10 is preferable, and 1 to reduce side reactions such as crosslinking. 5 is more preferable. Moreover, although the molecule | numerator which does not have a functional group at all may be contained, it is so preferable that the ratio is small.

  The content ratio of the polyamide resin (A) and the rubbery polymer (B) having a reactive functional group in the thermoplastic resin composition used in the present invention is 50 to 95 parts by weight and 5 to 50 parts by weight of a rubbery polymer having a reactive functional group are preferred. By containing 5 parts by weight or more of the rubbery polymer having a reactive functional group, the weld toughness can be further improved. The content of the rubbery polymer having a reactive functional group is more preferably 10 parts by weight or more, and further preferably 20 parts by weight or more. On the other hand, when the content of the rubbery polymer having a reactive functional group is 50 parts by weight or less, the rigidity of the molded product can be improved and the weld toughness can be further improved. The content of the rubbery polymer having a reactive functional group is more preferably 45 parts by weight or less, and still more preferably 40 parts by weight or less.

  In the thermoplastic resin composition constituting the molded article of the present invention, the polyamide resin (A) is a continuous phase (α) and the rubbery polymer (B) having a reactive functional group is a dispersed phase in an electron microscope observation. (Β) and fine particles having a particle diameter of 1 to 100 nm made of a compound formed by the reaction of a polyamide polymer and a rubbery polymer having a reactive functional group in the dispersed phase (β). It has a morphology in which the area occupied by the fine particles in (β) is 10% or more. By highly controlling the structure in the dispersed phase as described above, a thermoplastic resin composition having excellent weld toughness can be obtained. The dispersion layer (β) contains fine particles having a particle diameter of 1 to 100 nm made of a compound produced by the reaction of a polyamide resin and a rubbery polymer having a reactive functional group, so that a molded product can be injection molded or molded. Since the layered deformation of the dispersion layer (β) when an external force is applied to the product can be suppressed, the weld toughness can be improved. Such an effect is remarkably exhibited when the area occupied by the fine particles in the dispersed phase (β) is 10% or more.

  Here, a known technique can be applied to the morphology observation. However, under general molding conditions, the morphology does not change before and after molding. Therefore, in the present invention, an ISO test in which a thermoplastic resin composition is injection molded. After cutting the central part of the piece in the cross-sectional direction to 1 to 2 mm square and dyeing a rubbery polymer having a reactive functional group with ruthenium tetroxide, an ultrathin section of 0.1 μm or less (about 80 nm) is obtained with an ultramicrotome − Cut at 196 ° C., magnified 35,000 times, and observed with a transmission electron microscope. With respect to the obtained image, the basic structure and the presence or absence of fine particles having a particle diameter of 1 to 100 nm in the dispersed phase (β) are observed. Further, the area occupied by the fine particles in the dispersed phase (β) is calculated using image analysis software “Scion Image” manufactured by Scion Corporation.

  As a method for producing the thermoplastic resin composition having the morphology (hereinafter sometimes referred to as “polyamide resin-rubber polymer composite composition (α-β)”), the following preparation methods (1) to (1) to The method (3) is preferred. From the viewpoint of productivity, the method of preparation method (3) is more preferable.

Examples of the preparation method (1) include the method described in JP-A-2008-156604. That is, a twin-screw extruder comprising a polyamide polymer and a rubbery polymer having a reactive functional group, the ratio L / D of the screw length L to the screw diameter D being 50 or more and having a plurality of full flight zones and kneading zones And the maximum resin pressure of the resin pressure in the kneading zone in the screw is Pkmax (MPa), and the minimum resin pressure of the resin pressure in the full flight zone in the screw is Pfmin (MPa),
Pkmax ≧ Pfmin + 0.3
The method of melt-kneading and manufacturing on the conditions which satisfy | fill is mentioned. L / D is a value obtained by dividing the screw length L by the screw diameter D. The screw length is the length from the upstream end of the screw segment at the position (feed port) where the screw base material is supplied to the screw tip. In the extruder, the side to which raw materials are supplied may be referred to as upstream, and the side from which molten resin is discharged may be referred to as downstream. In this method, the resin pressure in the kneading zone is increased within a certain range from the resin pressure in the full flight zone, thereby effectively promoting the reaction between the polyamide resin and the rubbery polymer having a reactive functional group. It becomes possible.

  Examples of the preparation method (2) include a method described in International Publication No. 2009/119624. That is, there is a method in which a polyamide polymer and a rubbery polymer having a reactive functional group are produced by melt kneading while stretching and flowing. Here, the extension flow is a flow form in which molten resin is stretched in two flows flowing in opposite directions. On the other hand, generally used shear flow is a flow form in which molten resin undergoes shear deformation in two flows having different velocities in the same direction. In the elongational flow kneading used for the production of the polyamide resin-rubber polymer composite composition (α-β), since the dispersion efficiency is higher than the shear flow generally used in melt kneading, particularly reactive processing. In the case of alloying with a reaction as in the above, the reaction can proceed efficiently.

  Examples of the preparation method (3) include the method described in JP2011-0663015. That is, there is a method in which a polyamide resin and a rubbery polymer having a reactive functional group are melt-kneaded while stretching and flowing, and then melt-kneaded with a notch mixing screw.

In the preparation method (3), the inflow effect pressure drop before and after the zone of melt-kneading (extension flow zone) while stretching and flowing is preferably 100 to 500 kg / cm ² (9.8 to 49 MPa). The inflow effect pressure drop before and after the extension flow zone can be obtained by subtracting the pressure difference (ΔP ₀ ) in the extension flow zone from the pressure difference (ΔP) before the extension flow zone. When the inflow effect pressure drop before and after the extension flow zone is 9.8 MPa or more, the rate of extension flow formation in the extension flow zone is high, and the pressure distribution can be made more uniform. Moreover, when the inflow effect pressure drop before and after the extension flow zone is 49 MPa or less, the back pressure in the extruder is suppressed to an appropriate range, and stable production becomes easy.

  In the preparation method (3), when the length of one extension flow zone in the screw of the extruder is Lk and the screw diameter is D, Lk / D = 3 to 8 is the viewpoint of kneadability and reactivity. Therefore, it is preferable.

  In the preparation method (3), as a specific method for forming the extensional flow zone, the spiral angle θ, which is the angle between the top on the disk front end side and the top on the rear surface side, is 0 in the counter-rotating direction of the screw. A method of forming with a twist kneading disc in a range of ° <θ <90 °, and a flight screw in which a resin passage having a reduced cross-sectional area from the screw front end side to the rear end side is formed in the flight portion Preferred examples include a forming method, a method of forming from a resin passage provided in an extruder and having a cross-sectional area through which a molten resin passes is reduced for a while.

  In the preparation method (3), the notch refers to a product obtained by shaving a screw flight crest. The notch type mixing screw can increase the resin filling rate, and the molten resin passing through the mixing zone to which the notch type mixing screw is connected is easily affected by the extruder cylinder temperature. Therefore, even the molten resin that generates heat by promoting the reaction in the extension flow zone in the first half of the extruder can be efficiently cooled in the mixing zone composed of the notch mixing screw in the second half, and the resin temperature can be lowered. In addition, since the reaction is promoted in the first-half extension flow zone, the melt viscosity of the resin when passing through the second-half mixing zone is high, and shearing due to the notch of the notch-type mixing screw acts effectively to react. Will also be promoted. That is, the method of melt kneading with a notched mixing screw after melt kneading while stretching and flowing can improve kneadability and reactivity while suppressing the resin temperature rise, and the screw length L and screw diameter Polyamide resin-rubber polymer composite composition (α-β) which suppresses resin degradation due to heat generation and has excellent shock absorption even when the throughput is increased with a general-purpose large extruder having a short D ratio L / D ) Can be obtained.

  In the preparation method (3), a zone for melting and kneading with a notched mixing screw (hereinafter sometimes referred to as “mixing zone”) is a single screw having a screw pitch length of 0.1D to 0.5D, and It is preferable from the viewpoint of improving the cooling efficiency of the molten resin by filling the resin, improving the kneadability, and improving the reactivity, by connecting notched mixing screws having 8 to 16 notches per pitch. It is more preferable that a notch type mixing screw having a screw pitch length of 0.1D to 0.3D and a notch number of 10 to 15 per pitch is connected. Here, the single thread indicates that the screw flight has one crest when the screw rotates 360 degrees.

  In preparation method (3), when the length of one mixing zone in the screw of the extruder is Lm and the screw diameter is D, Lm / D = 5 to 15 is the cooling efficiency of the molten resin due to resin filling It is preferable from the viewpoint of improvement, kneadability improvement, and reactivity improvement.

  In the preparation method (3), it is preferable to provide the mixing zone at two or more locations from the viewpoint of improving the cooling efficiency of the molten resin by filling the resin, improving the kneadability, and improving the reactivity.

  In preparation method (3), 75% or more of the notch type mixing screw constituting the mixing zone is in the direction of screw rotation in the direction opposite to the rotation direction of the screw shaft. From the viewpoint of improving kneadability and reactivity, it is preferable.

  In preparation method (3), assuming that the extruder cylinder set temperature in the extension flow zone is Ck and the extruder cylinder set temperature in the mixing zone is Cm, melt kneading while satisfying Ck−Cm ≧ 60 In addition to greatly improving cooling efficiency, kneadability and reactivity can be greatly improved, which is preferable. In general, a chemical reaction tends to proceed at a higher reaction temperature. Conversely, when the resin temperature decreases, the reaction rate between the polyamide resin and the reactive functional group decreases. However, in the preparation method (3), even if the cylinder temperature of the mixing zone is lowered and the resin temperature is lowered, the reaction can proceed, and the impact absorption, impact resistance and heat resistance during high-speed tensioning can be reversed. Can increase sex. This is because a zone for melting and kneading is provided in the first half to promote the reaction between the polyamide resin and the reactive functional group, so that the melt viscosity when passing through the mixing zone is high, and the resin temperature is increased. If the melt viscosity is further increased and the melt viscosity is further increased, the shear due to the notch of the notch type mixing screw acts more strongly, and the reaction is promoted more than compensating for the decrease in the reaction rate due to the resin temperature decrease. . This effect is manifested for the first time in a screw configuration in which a mixing zone comprising a notched mixing screw is provided after the extension flow zone. On the other hand, for example, when melt kneading with a general kneading disk that cannot form an extension flow in the first half, the reaction rate of the thermoplastic resin and the reactive functional group is low, so notched mixing after the kneading disk zone Even if a mixing zone composed of screws is provided, the melt viscosity when passing through the mixing zone is low. Therefore, the shear due to the notch of the notch mixing screw is small, and the progress of the reaction is lower than that in the case where the first half has a zone for melt-kneading while stretching and flowing.

  In the preparation method (3), examples of the extruder to be used include a single screw extruder, a twin screw extruder, and a triaxial or more multi-screw extruder. Among these, a single screw extruder and a twin screw extruder are preferably used, and a twin screw extruder is particularly preferably used. Further, the screw of such a twin screw extruder is not particularly limited, and a fully meshed type, an incomplete meshed type, a non-meshed type screw, etc. can be used. It is a type. Further, the rotation direction of the screw may be either the same direction or a different direction, but is preferably the same direction rotation from the viewpoint of kneading property and reactivity. In the present invention, the most preferred screw is a co-rotating fully meshed type.

  The preparation method (3) is preferably applied to melt-kneading using a general-purpose twin screw extruder having an L / D of less than 50, and generates heat even when the throughput is increased by a twin screw extruder having a large screw diameter D. It is possible to obtain a polyamide resin composition that suppresses resin degradation due to heat resistance and has heat resistance, impact resistance, impact absorption, and the like.

  In the preparation method (3), the ratio of the total length of the zone for melt-kneading while stretching and flowing (extension flow zone) with respect to the total length of the screw of the extruder is 10 to 35%, and with respect to the total length of the screw of the extruder The ratio of the total length of the zone (mixing zone) for melting and kneading by the notch mixing screw is 20 to 35%, which improves the cooling efficiency of the molten resin by filling the resin, improves the kneadability, and improves the reactivity. It is preferable from the viewpoint.

  In the preparation method (3), the residence time in the extruder is preferably 30 to 300 seconds. The dwell time is the position of the screw base to which the raw material is supplied (feed port), together with the raw material, the colorant and the like are introduced, and the colorant and the like are extruded from the discharge port of the extruder. This is the time until the maximum degree of coloration of the extrudate by the colorant. When the residence time is 30 seconds or more, the reaction in the extruder is sufficiently accelerated, and the properties of the polyamide resin-rubber polymer composite composition (α-β) (balance of heat resistance, impact resistance, etc.) In addition, the impact absorbability that makes the unique viscoelastic property remarkably appear is further improved. When the residence time is 300 seconds or less, the thermal deterioration of the resin due to the long residence time can be suppressed.

  The thermoplastic resin composition used in the present invention may contain other components, if necessary, within a range that does not impair its properties.

  For example, you may contain other thermoplastic resins as needed in the range which does not impair the characteristic. Examples of such thermoplastic resins include polyester resins, polyphenylene sulfide resins, polyphenylene oxide resins, polycarbonate resins, polylactic acid resins, polyacetal resins, polysulfone resins, tetrafluoropolyethylene resins, polyetherimide resins, polyamideimide resins, polyimides. Examples thereof include resins, polyether sulfone resins, polyether ketone resins, polythioether ketone resins, polyether ether ketone resins, polyethylene resins, polypropylene resins, styrene resins such as polystyrene resins and ABS resins, and polyalkylene oxide resins. Two or more of these thermoplastic resins can be used in combination. When such thermoplastic resins are used, the content thereof is not particularly limited, but is 0.1 to 400 parts by weight with respect to 100 parts by weight of the total of the polyamide resin and the rubbery polymer having a reactive functional group. preferable.

  In addition, rubbers other than the rubbery polymer having a reactive group may be added as necessary as long as the characteristics are not impaired. Examples of such rubbers include ethylene-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid and ethylene-methacrylic acid, ethylene-unsaturated carboxylic acid esters such as ethylene-acrylic acid ester and ethylene-methacrylic acid ester. Polymers, acrylic ester-butadiene copolymers, for example, acrylic elastic polymers such as butyl acrylate-butadiene copolymers, copolymers of ethylene and fatty acid vinyl such as ethylene-vinyl acetate, ethylene-propylene-ethylidene norbornene Thermoplastic elastomers such as copolymers, ethylene-propylene non-conjugated diene terpolymers such as ethylene-propylene-hexadiene copolymers, butylene-isoprene copolymers, chlorinated polyethylene, polyamide elastomers, and polyester elastomers It is preferred examples. Two or more of these rubbers can be used in combination. When such rubbers are used, the content thereof is not particularly limited, but is preferably 0.1 to 400 parts by weight with respect to 100 parts by weight of the total of the polyamide resin and the rubbery polymer having a reactive functional group.

  Moreover, you may contain various fillers as needed in the range which does not impair the characteristic. The filler may be fibrous or non-fibrous, or a combination of fibrous filler and non-fibrous filler may be used. Examples of the filler include glass fiber, glass milled fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, stone-kow fiber, metal Fibrous fillers such as fibers, wollastonite, zeolite, sericite, kaolin, mica, clay, pyrophyllite, bentonite, asbestos, talc, alumina silicate and other silicates, alumina, silicon oxide, magnesium oxide, zirconium oxide, Metal compounds such as titanium oxide and iron oxide, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, hydroxides such as magnesium hydroxide, calcium hydroxide and aluminum hydroxide, Rasubizu, ceramic beads, non-fibrous fillers such as boron nitride and silicon carbide and the like, which may be hollow, it is also possible to further combination of these fillers 2 or more. In addition, these fibrous and / or non-fibrous fillers are pretreated with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, an epoxy compound, This is preferable in terms of obtaining superior mechanical properties.

  In order to improve strength, dimensional stability, etc., when such a filler is used, its content is not particularly limited, but it is 30 with respect to 100 parts by weight in total of the polyamide resin and the rubbery polymer having reactive functional groups. ˜400 parts by weight is preferred.

  Moreover, you may contain various additives as needed in the range which does not impair the characteristic. Examples of such various additives include crystal nucleating agents, anti-coloring agents, hindered phenols, hindered amines, hydroquinone series, phosphite series and substituted products thereof, copper halides, iodide compounds and the like, and heat. Stabilizers, resorcinol-based, salicylate-based, benzotriazole-based, benzophenone-based, hindered amine-based weathering agents, aliphatic alcohols, aliphatic amides, aliphatic bisamides, release agents such as ethylene bisstearylamide and higher fatty acid esters, p -Plasticizers such as octyl oxybenzoate and N-butylbenzenesulfonamide, lubricants, dyes such as nigrosine and aniline black, pigments such as cadmium sulfide, phthalocyanine and carbon black, alkyl sulfate type anionic antistatic agents Agent, 4th grade Nium salt type cationic antistatic agent, nonionic antistatic agent such as polyoxyethylene sorbitan monostearate, betaine amphoteric antistatic agent, hydroxide such as melamine cyanurate, magnesium hydroxide, aluminum hydroxide, Examples include flame retardants such as ammonium polyphosphate, brominated polystyrene, brominated polyphenylene oxide, brominated polycarbonate, brominated epoxy resins, or combinations of these brominated flame retardants and antimony trioxide, and foaming agents.

  As the antioxidant and the heat stabilizer, hindered phenol compounds and phosphorus compounds are preferably used. Specific examples of the hindered phenol compounds include triethylene glycol-bis [3-t-butyl- (5 -Methyl-4-hydroxyphenyl) propionate], N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamide), tetrakis [methylene-3- (3 ', 5'- Di-t-butyl-4′-hydroxyphenyl) propionate] methane, pentaerythrityltetrakis [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate], 1,3,5 -Tris (3,5-di-t-butyl-4-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H -Trione, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 4,4'-butylidenebis (3-methyl-6-t-butylphenol), n-octadecyl- 3- (3,5-di-tert-butyl-4-hydroxy-phenyl) propionate, 3,9-bis [2- (3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy ) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,3,5-trimethyl-2,4,6-tris- (3,5-di) -T-butyl-4-hydroxybenzyl) benzene and the like.

  Among them, ester type polymer hindered phenol type is preferable. Specifically, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, pentaerythrityl. Tetrakis [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate], 3,9-bis [2- (3- (3-t-butyl-4-hydroxy-5- Methylphenyl) propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane and the like are preferably used.

  Specific examples of such antioxidant and heat stabilizer phosphorus compounds include bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2,4-dithio). -T-butylphenyl) pentaerythritol di-phosphite, bis (2,4-di-cumylphenyl) pentaerythritol di-phosphite, tris (2,4-di-t-butylphenyl) phosphite, tetrakis ( 2,4-di-t-butylphenyl) -4,4'-bisphenylene phosphite, di-stearyl pentaerythritol di-phosphite, triphenyl phosphite, 3,5-di-butyl-4-hydroxybenzyl Examples thereof include phosphonate diethyl ester.

  Two or more kinds of various additives can be used in combination. The content is not particularly limited, but is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight in total of the polyamide resin and the rubbery polymer having a reactive functional group.

  These thermoplastic resins, rubbers, and various additives can be blended at an arbitrary stage for producing the thermoplastic resin composition. For example, polyamide resins, rubber weights having reactive functional groups, and the like. Examples thereof include a method of adding at the time of blending the coalescence and a method of adding by a method such as a side feed during melt kneading.

  By injection molding the obtained thermoplastic resin composition, a molded product having a through hole and a weld in contact with the through hole can be obtained.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited by a following example. First, an evaluation method in each example and comparative example will be described.

(1) Morphological observation Rubber polymer (B) having a reactive functional group with ruthenium tetroxide by cutting the center part in the cross-sectional direction of the dumbbell-shaped test piece obtained in each example and comparative example into 1 to 2 mm square. Then, an ultrathin section of 0.1 μm or less (about 80 nm) was cut at −196 ° C. with an ultramicrotome, magnified 35,000 times, and observed with a transmission electron microscope. With respect to the obtained image, the basic structure and the presence or absence of fine particles of 1 to 100 nm in the dispersed phase (β) were observed. Used and calculated.

(2) Measurement of tensile strength and tensile elongation at break For tensile test pieces having welds and tensile test pieces not having welds obtained in each of the examples and comparative examples, except that the speed is 1000 mm / min, ISO527-1, According to 2, the distance between chucks was 115 mm, a tensile test was performed, and the tensile strength and tensile elongation at break were measured. The tensile elongation at break was the elongation at break based on a distance between chucks of 115 mm. The measurement was performed on four test pieces, and the number average value was calculated.

(3) Charpy impact strength measurement About the impact test piece obtained by each Example and the comparative example, the Charpy impact test was implemented according to ISO179 and the impact strength was measured.

  (4) Measurement of maximum tensile load and tensile breaking displacement For the square plate having welds in contact with the through holes obtained in each of the examples and comparative examples, the length L of the welds in contact with the through holes at a point 60 mm from the gate is 5 mm. A test piece having a width of 13 mm and a length of 80 mm was cut out. The obtained test piece was subjected to a tensile test at a speed of 50 mm / min and a distance between chucks of 30 mm, and the maximum tensile load and the tensile breaking displacement were measured. The measurement was performed on four test pieces, and the number average value was calculated.

  In a molded product having a weld that is in contact with the through hole, the higher the tensile strength, the maximum tensile load, the tensile elongation at break, and the tensile fracture displacement, the more the cracking due to low-speed deformation can be suppressed. Cracking can be suppressed.

The raw materials used in each example and comparative example are shown below.
Polyamide resin A: Polyamide 6 resin having a relative viscosity of 2.70 measured at 25 ° C. in a 98% sulfuric acid solution having a melting point of 225 ° C. and a resin concentration of 0.01 g / ml.
Rubbery polymer A having a reactive functional group: Glycidyl methacrylate-modified polyethylene copolymer ““ Bond First ”(registered trademark) BF-7L” (manufactured by Sumitomo Chemical Co., Ltd.).
Rubber polymer B having a reactive functional group: ethylene-methacrylic acid-zinc methacrylate copolymer “Himiran” (registered trademark) 1706 (manufactured by Mitsui DuPont Polychemical Co., Ltd.).

Example 1
The polyamide resin A and the rubbery polymer B having reactive functional groups were mixed in the blending composition shown in Table 1, and while performing nitrogen flow, the screw diameter was 65 mm, and the L / D of two screws of two-thread screw = 45, using the same direction rotation complete mesh type twin screw extruder (manufactured by Nippon Steel Works, TEX-65αII), melt kneading at a cylinder temperature of 260 ° C., screw rotation speed of 300 rpm, extrusion rate of 200 kg / h, Strand-shaped molten resin was discharged from the discharge port (L / D = 45). The screw configuration is a twist kneading disc in which the helical angle θ, which is the angle between the top of the kneading disc and the top of the rear surface, is 20 ° in the counter-rotating direction from the position of L / D = 13. Were connected to each other at Lk / D = 5.0 minutes to form a zone (extension flow zone) for melt kneading while stretching and flowing. Further, a reverse screw zone of L / D = 0.5 was provided downstream of the extension flow zone. When the ratio (%) of the total length of the extension flow zone to the total length of the screw was calculated by (total length of extension flow zone) ÷ (total length of screw) × 100, it was 11%. Further, as a result of obtaining the inflow effect pressure drop before and after the extension flow zone by subtracting the pressure difference (ΔP ₀ ) in the extension flow zone from the pressure difference (ΔP) before the twist kneading disc, 19.6 MPa Met. Furthermore, from a position of L / D = 23 and 31, a notch type mixing screw having a single thread screw and a screw pitch of 0.25D and a number of notches of 12 per pitch is connected to Lm / D = 5.0 minutes respectively. Thus, two mixing zones were formed. When the ratio (%) of the total length of the mixing zone to the total length of the screw was calculated by (total length of the mixing zone) / (total length of the screw) × 100, it was 22%. Further, in the notch type mixing screw constituting the mixing zone, the ratio (%) of the screw in the direction of screw rotation in the direction opposite to the rotation direction of the screw shaft was set to 80%. A vent vacuum zone was provided at a position of L / D = 38, and volatile components were removed at a gauge pressure of −0.1 MPa. The discharged resin was drawn in a strand shape, passed through a cooling bath, cooled, and cut while being taken out by a pelletizer to obtain polyamide resin composition pellets.

  The obtained polyamide resin composition pellets are injection molded using a FANUC S-2000i molding machine under conditions of a molding temperature of 260 ° C., a mold temperature of 80 ° C., an injection speed of 100 mm / second, and a screw rotation speed of 100 rpm. As a result, a dumbbell-shaped test piece having a length of 127 mm, a width of 10 mm, and a thickness of 4 mm was obtained. At this time, a tensile test piece having no weld is prepared by making a portion where the molten resin of the mold is poured into one end in the length direction, and a portion where the molten resin is poured is taken as both ends in the length direction. A tensile test piece having a weld in the center in the vertical direction was produced. Moreover, the impact test piece was produced by cutting out into the length of 80 mm from the parallel part of the above-mentioned tensile test piece, and performing a notch process.

  Also, by injection molding under the same conditions as described above except that the injection speed is set to 20 mm / second, the distance is 119 mm, the width is 80 mm, the thickness is 2 mm, and the distance of 20 mm, 60 mm, and 100 mm from the gate at the center in the width direction. A square plate having a through hole with a diameter of 8 mm was obtained. Table 1 shows the results of evaluation by the method described above. In the morphology observation, the polyamide resin forms a continuous phase (α), the rubbery polymer having a reactive functional group forms a dispersed phase (β), and in the dispersed phase (β) It was confirmed that fine particles having a particle diameter of 1 to 100 nm made of a compound produced by the reaction of a rubbery polymer having a group and that the area occupied by fine particles in the dispersed phase (β) was 30%.

(Comparative Example 1)
The polyamide resin A pellets were injection molded under the same conditions as in Example 1 to obtain tensile test pieces, impact test pieces, and test pieces having welds in contact with the through holes. Table 1 shows the results of evaluation by the method described above.

(Comparative Examples 2-3)
A polyamide resin A and a rubbery polymer A or B having a reactive functional group are mixed in the blending composition shown in Table 1, and while flowing nitrogen, a screw diameter of 65 mm and two screws with two threads are used. Melting and kneading using L / D = 45 co-rotating fully meshed twin screw extruder (manufactured by Nippon Steel Works, TEX-65αII) at a cylinder temperature of 260 ° C., screw rotation speed of 300 rpm and extrusion rate of 200 kg / h The strand-shaped molten resin was discharged from the discharge port (L / D = 45). In the screw configuration, general kneading disks were connected at L / D = 5.0 minutes from the positions of L / D = 13, 23, 31 to form a kneading zone. Further, a reverse screw zone with L / D = 0.5 was provided downstream of the kneading zone. When the ratio (%) of the total length of the kneading zone to the total length of the screw was calculated by (total length of kneading zone) / (total length of screw) × 100, it was 33%. A vent vacuum zone was provided at a position of L / D = 38, and volatile components were removed at a gauge pressure of −0.1 MPa. The discharged resin was drawn in a strand shape, passed through a cooling bath, cooled, and cut while being taken out by a pelletizer to obtain polyamide resin composition pellets.

  The obtained polyamide resin composition pellets were injection molded under the same conditions as in Example 1 to obtain tensile test pieces, impact test pieces, and test pieces having welds in contact with the through holes.

  Table 1 shows the results of evaluation by the method described above. In addition, in the morphology observation, it was confirmed that the polyamide resin was a continuous phase (α) and the rubbery polymer having a reactive functional group was a dispersed phase (β). Fine particles composed of a compound formed by the reaction of a rubbery polymer having a reactive functional group were not observed.

1 Molded product having a through hole and a weld contacting the through hole 2 Gate 3 Weld 4 Through hole

Claims (3)

  Polyamide resin (A) and rubber polymer (B) having at least one reactive functional group selected from the group consisting of epoxy groups, acid anhydride groups, amino groups, carboxyl groups, carboxyl metal salts and oxazoline groups In the electron microscope observation, the polyamide resin (A) forms the continuous phase (α), the rubbery polymer (B) having the reactive functional group forms the dispersed phase (β), and the dispersed phase (Β) contains fine particles having a particle diameter of 1 to 100 nm made of a compound formed by the reaction of the polyamide resin (A) and the rubbery polymer (B) having a reactive functional group, in the dispersed phase (β) A molded article made of a thermoplastic resin composition having a morphology in which the area occupied by the fine particles is 10% or more, comprising a through hole as a fixing means and a well in contact with the through hole Molded article having a.   The ratio (L / T) of the length (L [mm]) of the weld contacting the through hole to the thickness (T [mm]) of the welded part of the molded product is 0.1 to 100. Molding.   The method for producing a molded article according to claim 1 or 2, wherein the thermoplastic resin composition is injection-molded.

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