Technical field
[0001]
　The present invention relates to a polyamide resin composition.
Background technique
[0002]
　Polyamide resins have excellent properties as engineering plastics, automobile, machinery, are widely used in various industrial fields such as electric and electronic. In order to improve the mechanical properties of the polyamide resins, there is known a technique of compounding carbon fibers, fillers such as glass fibers.
　For example, a polyamide 6, the proposed sliding component material comprising a glass fiber non-circular cross-section which is by 10 major and the ratio of the shorter diameter of 1.2 in the cross section in a particular content, low warpage, high limit PV value, low dynamic friction coefficient, there is a superior abrasion resistance (e.g., see Patent Document 1). Also, a specific polyamide resin, reinforced polyamide molding material comprising a glass fiber with a specific content of which has a non-circular cross-section is proposed, molded parts having high rigidity and resistance to transverse is possible to manufacture are (e.g., see Patent Document 2).
　On the other hand, a thermoplastic resin such as polyamide resin, cross-section is proposed for laser welding thermoplastic resin composition comprising a glass fiber with a specific content of a flat shape, excellent mechanical strength good laser welding characteristics there is a (e.g., see Patent Document 3).
CITATION
Patent Document
[0003]
Patent Document 1: WO 2007/097214
Patent Document 2: JP 2014-111779 Patent Publication
Patent Document 3: JP 2013-53316 JP
Summary of the Invention
Problems that the Invention is to Solve
[0004]
　However, the polyamide resin composition containing glass fibers of a conventional non-circular cross-section, and the suppression of dimensional change upon water absorption in the molded body, and excellent abrasion resistance after water absorption, excellent and impact strength, high surface strength it has been difficult to satisfy door at the same time.
　The present invention, in the case of forming a molded body, the suppression of dimensional change upon water absorption, and excellent abrasion resistance after water absorption, excellent and impact strength, polyamide can be satisfied high surface strength and at the same time to provide a resin composition and an object.
Means for Solving the Problems
[0005]
　Specific means for solving the problems are as follows.
　A glass fiber having a non-circular cross-section, wherein the polyamide resin containing a structural unit number of carbon atoms is more than 6 for one amide group, the number average molecular weight of the polyamide resin is 20,000 to 40,000, the glass fibers content is a polyamide resin composition is not more than 40 mass% to 15 mass%.
Effect of the invention
[0006]
　According to the present invention, in the case of forming a molded body, the suppression of dimensional change upon water absorption, and excellent abrasion resistance after water absorption, to satisfy excellent and impact strength, and a high surface strength simultaneously it is possible to provide a polyamide resin composition.
DESCRIPTION OF THE INVENTION
[0007]
　The content of each component in the compositions herein, when substances corresponding to the component in the composition there are a plurality, unless otherwise specified, the total amount of the plural substances present in the composition means.
[0008]
[Polyamide Resin Composition]
　The polyamide resin composition according to the present embodiment includes a glass fiber having a non-circular cross-section, a polyamide resin containing a structural unit number of carbon atoms is more than 6 for one amide group, wherein the the number average molecular weight of the polyamide resin is 20,000 to 40,000, a content of the glass fibers is 60 wt% or less than 15 wt%. A polyamide resin having a number average molecular weight of contain and specific range of many constitutional units number of carbon atoms, to form a molded body of glass fiber having a non-circular cross section polyamide resin composition containing a specific content ratio, water it can be achieved and dimensional stability when, excellent wear resistance was after water absorption, excellent and impact strength, and a high surface hardness. And dimensional stability during water absorption, to achieve a good wear resistance after water absorption is because showing a low water absorption of the polyamide resin composition according to the present embodiment is excellent.
[0009]
(Polyamide resin)
　polyamide resin, the structural unit (hereinafter, also referred to as "specific structural unit") the number of carbon atoms for one amide group exceeds 6 not particularly limited as long as it contains. Number of carbon atoms for one amide group in a particular structural unit, from the viewpoint of excellent wear resistance and impact resistance after dimensional stability and water absorption during water absorption, preferably 7 to 12, 8 to 12 more preferable. Here the number of carbon atoms for one amide group in the structural units, for example, if the polyamide 6 or polyamide 66, the number of carbon atom per amide group is a 6, a 11 if polyamide 11, polyamide 12 if a 12, a 9 if polyamide 612.
[0010]
　Polyamide resin, it is preferred that the average number of carbon atoms for one amide group in all structural units is more than 6, more preferably 7 to 12, more preferably 8 to 12. The average number of carbon atoms for one amide group in all structural units, for example, a 6 if 6/66 copolymer, polyamide 6/12 copolymer (copolymerization ratio of 1: 1) if 9 become.
[0011]
　The polyamide resin, made of a diamine and dicarboxylic acid, and the like made from those consisting of lactams or aminocarboxylic acids and a copolymer of two or more kinds of these.
[0012]
　Examples of the diamine, ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, peptidase data diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, tridecane diamine, tetradecane diamine , pentadecane diamine, hexadecane diamine, heptamethylene decanediamine, octadecane diamines, nona decane diamine, eicosane diamine, 2-methyl-1,8-octane diamine, 2,2,4 / 2,4,4-trimethylhexamethylene diamine, etc. aliphatic diamines, 1,3- / 1,4-cyclohexyl diamine, bis (4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) propane, bis (3 Methyl-4-aminocyclohexyl) methane, (3-methyl-4-aminocyclohexyl) propane, 1,3- / 1,4-bis-aminomethyl cyclohexane, 5-amino-2,2,4-trimethyl-1-cyclo pentane methylamine, 5-amino-1,3,3-trimethylcyclohexane methylamine, bis (aminopropyl) piperazine, bis (aminoethyl) piperazine, alicyclic diamines such as norbornane methylene amines, m-/ p-xylylene aromatic diamines such as phenylenediamine and the like. Diamine Among these carbon atoms greater than 6 are preferred.
[0013]
　Examples of the dicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanoic dioic acid, dodecanedioic acid, tridecane dioic acid, tetradecanedioic acid, pentadecanoic dioic acid, hexadecane dioic acid, octadecanedioic acid, aliphatic dicarboxylic acids such as eicosanedioic acid, 1,3 / 1,4-cyclohexanedicarboxylic acid, di-cyclohexane-4,4'-dicarboxylic acid, norbornane carboxylic acid alicyclic dicarboxylic acids and the like, isophthalic acid, terephthalic acid, 1,4 / 1,8 / 2,6 / 2,7-naphthalene aromatic dicarboxylic acids such as dicarboxylic acid and the like. These more dicarboxylic acids from any number of carbon atoms is 6 inside is preferable.
[0014]
　The lactams, .epsilon.-caprolactam, enantholactam, undecanoic lactam, dodecane lactam, alpha-pyrrolidone, alpha-piperidone and the like. As the aminocarboxylic acid 6-aminocaproic acid, 7-amino heptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid. These often lactams and aminocarboxylic acids carbon atoms than 6 among preferred.
[0015]
　The homopolymers of the polyamide resin having a structural unit number of carbon atoms for one amide group exceeds 6, for example, Poriundekan acid lactam (polyamide 11), polylauryllactam (polyamide 12), polytetramethylene dodecamide ( polyamide 412), poly pentamethylene azelamide (polyamide 59), poly pentamethylene sebacamide (polyamide 510), poly pentamethylene dodecamide (polyamide 512), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide bromide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), poly nona adipamide (polyamide 96), poly nonamethylene azelamide (polyamide 99), poly nonamethylene sebacamide (polyamide 91 ), Poly nonamethylene dodecamide (polyamide 912), polydecamethylene adipamide (polyamide 106), polydecamethylene azelamide (polyamide 109), polydecamethylene deca bromide (polyamide 1010), polydecamethylene dodecamide (polyamide 1012), polydodecamethylene adipamide (polyamide 126), polydodecamethylene azelamide (polyamide 129), polydodecamethylene sebacamide (polyamide 1210), poly dodecamethylene dodecamide (polyamide 1212), cited polyamide 122 and the like It is.
[0016]
　As the copolymer of the polyamide resin having a structural unit number of carbon atoms for one amide group exceeds 6, for example, caprolactam / hexamethylene diamino azelaic acid copolymer (polyamide 6/69), caprolactam / hexamethylene diamino sebacic acid copolymer (polyamide 6/610), caprolactam / hexamethylene aminoundecanoic acid copolymer (polyamide 6/611), caprolactam / hexamethylene-aminododecanoic acid copolymer (polyamide 6/612), caprolactam / aminoundecanoic acid copolymer (polyamide 6/11), caprolactam / lauryllactam copolymer (6/12), caprolactam / hexamethylene diamino adipic acid / lauryl lactam (polyamide 6/66/12), caprolactone N / a hexamethylene diamino adipic acid / hexamethylene diamino sebacate (polyamide 6/66/610), and caprolactam / hexamethylene diamino adipic acid / hexamethylene diamino dodecane dicarboxylic acid (polyamide 6/66/612), and the like.
[0017]
　These homopolymers, copolymers can be used in the form of each alone or in mixtures.
　Among these, dimensional stability during water absorption, in view of impact strength and surface strength, polyamide 11, polyamide 12, polyamide 610, polyamide 612, polyamide 6/12, is selected from the group consisting of polyamide 6/66/12 It is preferably at least one that, polyamide 11, polyamide 12, at least one selected from the group consisting of polyamide 610 and polyamide 612 is more preferable.
[0018]
　The molecular weight of the polyamide resin is 20,000 to 40,000 number average molecular weight, preferably at 22000 or 38000 or less, more preferably 23000 or more 36000 or less. By number average molecular weight of the polyamide resin is in the above range, it is possible to achieve better wear resistance after water absorption.
[0019]
　There is no particular limitation on the relative viscosity of the polyamide resin, the polymer is dissolved 1g of 96% concentrated sulfuric acid 100 ml, preferably relative viscosity measured at 25 ° C. is 1.8 to 5.0, 2.0 more than 3.5 or less is more preferable. If the relative viscosity is less than the upper limit of the above range, there is a tendency that good processability is obtained, if it is lower than the lower limit, there is a tendency that the mechanical strength is improved.
[0020]
　Content in the total amount of the polyamide resin composition of polyamide resin, from the viewpoint of dimensional stability during mechanical properties and water absorption is preferably 40 mass% or more and 85 mass% or less, more preferably 80 wt% or more 55 wt% or less , more preferably more than 65 wt% 75 wt% or less.
[0021]
(Glass fiber)
　Examples of glass fibers, is not particularly limited as long as the cross section is non-circular. The cross-section non-circular, in cross section perpendicular to the length direction of the glass fiber, of the two points of the outer periphery of the cross section, the major axis distance connecting two points having the maximum outer periphery of the cross section of the straight line perpendicular to the major axis the distance between two points crossing the exists and a minor diameter connecting two points having the maximum length of the major axis and minor axis which means a different shape. Ratio minor axis of the major axis of the glass fibers may be greater than 1, from the viewpoint of mechanical properties, for example, 1.2 to 10, preferably 1.5 to 6, 1.7 to 4.5 It is more preferable.
[0022]
　There is no particular restriction on the sectional shape of the glass fiber, typically, cocoon-shaped, oval, semi-circular, arcuate, rectangular, parallelogram, or those of these similar type used. In practice, flowability, mechanical properties, from the viewpoint of low warpage, cocoon-shaped, oval or rectangular are preferred. The cross-sectional shape of the glass fibers, for example, referred to the description of JP-62-268612 JP.
[0023]
　The thickness of the glass fiber is not particularly limited. Minor diameter of the glass fiber is usually 0.5μm or 25μm or less, the major axis is 300μm or less than 1.25 .mu.m.
　Fiber length of the glass fibers typically 1mm or 15mm or less, preferably 1.5mm or more 12mm or less, and more preferably 2mm or more than 6mm.
　The aspect ratio obtained by dividing the fiber length by the average value of the major axis and the minor axis of the glass fiber is usually 10 or more, rigidity, mechanical strength, in terms of fluidity, preferably 15 or more to 100 or less.
[0024]
　The glass constituting the fiberglass, A glass, C glass, made of the composition, such as E glass and the like, from the viewpoint of the thermal stability of the polyamide resin, E glass is preferred. Glass fibers can also be a silane coupling agent, titanium coupling agent, it may be surface treated with a surface treatment agent of the other macromolecules or small molecules. By being surface-treated to improve the dispersibility and adhesion to the polyamide resin.
[0025]
　Content in the total amount of the polyamide resin composition of the glass fiber is not more than 15 wt% to 60 wt%, impact strength, in terms of dimensional stability and surface hardness of the absorption of water, 20 wt% to 45 wt% or less, and more preferably 35 mass% or less than 25 wt%.
[0026]
　The polyamide resin composition, other components within a range not to impair the effects of the present invention, for example, plasticizers, impact resistant material, the heat-resistant material, foaming agent, weathering agent, crystal nucleating agent, crystallization accelerator, release agent , lubricants, antistatic agents, flame retardants, flame retardant aids, pigments, can be appropriately compounded functionalizing agent such as a dye or the like.
[0027]
　Polyamide resin composition, the glass fibers of non-circular cross section of the polyamide resin and a predetermined amount of the uniaxial or biaxial extruder, is produced by melt-kneading in a Banbury mixer or the like.
　By molding a polyamide resin composition obtained, it is possible to obtain a desired molded body. As the molding method, extrusion molding method, blow molding method, injection molding method, etc. can be employed.
[0028]
　Polyamide resin composition, automobiles and machinery gears, pulleys, cams, bearings, but is used for a cable housing, etc., there is no harm in using a member that requires other similar functions.
Example
[0029]
　Is specifically described below by the present invention examples and comparative examples, the present invention is not limited to these examples. Incidentally, The physical properties measurement method of resin and molded articles used in Examples and Comparative Examples below.
[0030]
(1) Charpy impact strength: according to ISO 179-1, room temperature, were subjected to edgewise impact test using a test piece A notched thickness 4 mm. (N = 10)
[0031]
(2) dimensional change rate upon water absorption: Sumitomo Heavy Industries, to prepare a 200 × 40 × 3 mm molded article at Ltd. SE-100D injection molding machine, 48 hours after standing under vacuum, the surface of the molded article the distance between the transferred marking line measured by OLYMPUS Ltd. microscope were sized before water absorption treatment.
　Then 23 ° C., after standing 168 hours under RH 50% atmosphere, a scribe line distance which is transferred to the surface of the molded article was measured by OLYMPUS Ltd. microscope were the dimensions after water absorption process.
　Obtained in the above, by using the dimension after size and water absorption treatment before water absorption treatment was calculated upon absorbing water dimensional change by the following equation.
　　Upon absorbing water dimensional change
　　　= (dimension after water absorption treatment - the dimensions of the pre-water treatment) / water pretreatment size × 100
[0032]
(3) Rockwell hardness R scale: In accordance with ISO2039-2, the hardness was measured by the R scale. Measurement of Rockwell Hardness R-scale was performed and after prior water treatment of the test sample and (untreated) water treatment. The water treatment has been dipped in 2 hours and 6 hours Thomas Scientific Instruments Co. thermostat bath T104NB set the test sample at a set temperature 80 ° C..
[0033]
(4) Molecular weight: using a Tosoh Corp. HLC-802A, was calculated number average molecular weight in terms of PMMA subjected to GPC measurement under the following conditions.
　Column: Shodex HFIP-LG + HFIP- 806M
　Eluent: HFIP-10 mM CF 3 COONa
　Temperature: 40 ° C.
　flow rate: 0.8 ml / min
　Sample concentration: about 0.1 wt / vol%
　Injection volume: 500 [mu] l
[0034]
(5) Abrasion resistance at water absorption (after water treatment amount of wear): Sumitomo Heavy Industries, to create a molded article of 40 mm × 50 mm × 3 mmt at Ltd. SE-100D injection molding machine to obtain a test sample . Outer diameter 25.6m as counterpart material, the inner diameter 20 mm, those of the hollow length 15mm created by material S45C. The friction and wear testing machine was used, Ltd. A & D Company Ltd. EFM-III-EN. The test sample was immersed for 2 hours and 6 hours at a set temperature 80 Thomas Scientific Instruments set to ° C. (KK) constant temperature water bath T104NB. After the above treatment, wiping the water surface of the test sample was left for 48 hours in a vacuum state. Using a sample after 80 ° C. water treatment obtained above, after measuring the initial weight of the test sample, test machine attached to the lower portion, mounting the counterpart material testing machine top, test load 25 kgf, peripheral speed 100 mm / performed 240 minute test at sec, were weighed test specimen after the test. Obtained from the above was calculated wear amount from the difference between the weight after the test to the initial weight after 80 ° C. water treatment.
[0035]
· Polyamide resin
PA6-1: Number polyamide
6 having an average molecular weight 13000 PA6-2: Number polyamide
6 having an average molecular weight 30000 PA66-1: Number polyamide
66 having an average molecular weight 20000 PA66-2: Number polyamide
66 having an average molecular weight 34000 PA12-1 : number polyamide
12 having an average molecular weight 24000 PA12-2: number average polyamide
12 having a molecular weight of 30000 PA12-3: number average polyamide
12 molecular weight 35000 PA12-4: number average polyamide
12 molecular weight 14000 PA12-5: number-average molecular weight of 41000 polyamide 12
[0036]
Glass fiber
GF1: cross-sectional shape rectangular glass fibers (Nitto Boseki Co., Ltd. CSG3PA-820S)
　ratio of the major axis and the minor axis 4, fiber diameter 7 × 28 .mu.m
GF2: cross-section a circular glass fiber (Nippon Electric Glass Co., Ltd. ECS03T249H )
　fiber diameter 10.5μm
[0037]
Examples 1 6, Comparative Examples 1 to 7
　the polyamide resin and glass fiber as described in Table 1 were melt-kneaded at TEX44HCT twin-screw kneader to prepare a polyamide resin composition pellet of interest.
　Next, the resulting pellets cylinder temperature 290 ° C., a mold temperature of 80 ° C., to produce the various test pieces were evaluated for various physical properties. The results obtained are shown in Table 2.
[0038]
[Table 1]

[0039]
[Table 2]

Industrial Applicability
[0040]
　The polyamide resin composition of the present invention, it is possible to satisfy the suppression of dimensional change upon water absorption in the molded body, and excellent abrasion resistance after water absorption, excellent and impact strength, and a high surface strength simultaneously, particularly preferably used in the sliding member or the like. In particular, gears, bearings, pulleys, are suitably used for the sliding member of the bearing or the like.
[0041]
　Japanese Patent Application No. 2015-200937: disclosure (filed Oct. 9, 2015) in its entirety is incorporated herein by reference.
　All documents described herein, patent applications, and technical standards, each individual publication, patent application, and that the technical specification is incorporated by reference to the same extent as if marked specifically and individually, It incorporated by reference herein.

The scope of the claims
[Claim 1]
　A glass fiber having a non-circular cross-section,
　and a polyamide resin containing a structural unit number of carbon atoms is more than 6 for one amide group
include,
　number average molecular weight of the polyamide resin is 20,000 to 40,000,
　the glass fibers the content is 60 mass% or less than 15 wt%, the polyamide resin composition.
[Claim 2]
　The polyamide resin, polyamide 11, polyamide 12, polyamide 612, polyamide 610, is at least one selected from the group consisting of polyamide 6/12 and polyamide 6/66/12, polyamide resin composition of claim 1 Stuff.
[Claim 3]
　The polyamide resin is a polyamide 12, a polyamide resin composition according to claim 1.
[Claim 4]
　The polyamide number average molecular weight of the resin is 36000 or less than 23000, the polyamide resin composition according to any one of claims 1 to 3.
[Claim 5]
　Molded article comprising the polyamide resin composition according to any one of claims 1 to 4.