Polyester elastomer resin composition

Abstract

Provided is a polyester elastomer resin composition that retains mechanical properties, and in which the lubricant does not dissolve in water during washing of the molded article with water, and also does not dissolve in a nonpolar solvent (heptane) during washing of the molded article, and that is excellent in sound resistance and abrasion resistance. A polyester elastomer resin composition containing 0.1 to 5 parts by mass of polyoxytetramethylene polyoxyethylene glycol (B) with respect to 100 parts by mass of a polyester elastomer (A) composed of a hard segment made of a polyester composed of an aromatic dicarboxylic acid and an aliphatic and / or alicyclic diol as constituent components, and at least one soft segment selected from an aliphatic polyether, an aliphatic polyester, and an aliphatic polycarbonate.

Description

Technical Field

[0001] The present invention relates to a polyester elastomer resin composition. Specifically, the present invention relates to a polyester elastomer resin composition that retains mechanical properties, and in which the lubricant does not dissolve in water even when a molded article made of the polyester elastomer resin composition is washed with water, and the lubricant does not dissolve even when the molded article is washed with a non-polar solvent (heptane), and that has excellent noise resistance and abrasion resistance.

Background Art

[0002] Conventionally, in order to impart abrasion resistance to a thermoplastic polyester elastomer, it has been studied to blend a solid lubricant such as a fatty acid amide compound (see Patent Documents 1 and 2). Further, as a liquid lubricant, it has been studied to blend a small amount of a single polyether or a copolymer polyether composed of two or more different alkylene units (see Patent Documents 3 and 4).

[0003] In the method of adding a solid lubricant as in Patent Documents 1 and 2, although the solid lubricant quickly bleeds out to the surface of the molded article and short-term abrasion resistance can be imparted, the solid lubricant present on the surface during a long-term sliding test is scraped off, and sustained abrasion resistance cannot be exhibited. Further, when water is present at a location where the lubricant on the surface of the molded article has been scraped off, local variations occur in the frictional state on the surface of the molded article, resulting in vibration noise and a phenomenon called noise generation.

[0004] In the method of adding a single polyether as in Patent Documents 3 and 4, although the lubricant remains on the surface of the molded article continuously over a long period, since the blended polyether component exhibits hydrophilicity, when the surface of the molded article is washed with water, it dissolves or is washed away by water, and the lubricant is easily scraped off from the surface of the molded article, resulting in problems such as noise generation at the start of sliding.

[0005] In response to this problem, a polyester elastomer resin composition has been proposed that uses a combination of a solid lubricant such as a fatty acid amide compound and a liquid lubricant of a copolymer polyether composed of ethylene oxide units and propylene oxide units (see Patent Document 5).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0007] The polyester elastomer resin composition of Patent Document 5 has a certain effect on the sound rattling resistance after water washing. However, for molded products that require a higher level of sound rattling resistance, not only the sound rattling resistance after water washing but also the sound rattling resistance after washing with a non-polar solvent (heptane) are required. It has been found that the conventional technology cannot achieve the sound rattling resistance against such two types of cleaning solvents.

[0008] The present invention was devised in view of the current state of such conventional technologies, and its object is to obtain long-term and continuous abrasion resistance while maintaining mechanical properties, and for the water washing of molded products, the lubricant does not dissolve in water, and for the heptane washing of molded products, the lubricant does not dissolve, and to provide a polyester elastomer resin composition excellent in sound rattling resistance after washing.

Means for Solving the Problems

[0009] As a result of intensive studies to achieve the above object, the present inventors have found that by using polyoxytetramethylene polyoxyethylene glycol as a lubricant, it is possible to achieve sound resistance after washing and long-term stable abrasion resistance without being easily detached from the surface of the molded article even during washing with water and washing with heptane, and thus completed the present invention.

[0010] That is, the present invention is as follows. [1] 0.1 to 5 parts by mass of polyoxytetramethylene polyoxyethylene glycol (B) is contained with respect to 100 parts by mass of a polyester elastomer (A) composed of a hard segment made of an aromatic dicarboxylic acid and an aliphatic and / or alicyclic diol and at least one soft segment selected from an aliphatic polyether, an aliphatic polyester, and an aliphatic polycarbonate. Po Polyester elastomer resin composition A polyester elastomer resin composition characterized in that the number average molecular weight of the polyoxytetramethylene polyoxyethylene glycol (B) is 800 to 4000. 2 The polyester elastomer resin composition according to [1], wherein the ratio of the tetramethylene oxide unit to the ethylene oxide unit of the polyoxytetramethylene polyoxyethylene glycol (B) is 10:90 to 90:10 (molar ratio). to The polyester elastomer resin composition according to [1]. 3 The polyester elastomer resin composition according to [1], wherein the soft segment of the polyester elastomer (A) is an aliphatic polyether. to The polyester elastomer resin composition according to [1]. 4 The polyester elastomer resin composition according to [1], further containing 0.5 to 10 parts by mass of a polyamide resin (C) with respect to 100 parts by mass of the polyester elastomer (A). to The polyester elastomer resin composition according to [1]. 5 The polyester elastomer resin composition according to [1], further containing 0.1 to 5 parts by mass of a thickener (D) with respect to 100 parts by mass of the polyester elastomer (A), and the thickener (D) is at least one compound selected from an epoxy compound and a carbodiimide compound. to ​​​​The described polyester elastomer resin composition. 6 The melt flow rate (MFR) value at 230 °C and a load of 2.16 kg, measured in accordance with the flow test method for thermoplastic plastics specified in JIS K7210, is 3 g / 10 min or less. [1 to The described polyester elastomer resin composition.

Advantages of the Invention

[0011] In the polyester elastomer resin composition of the present invention, a specific liquid lubricant stably bleeds out to the surface layer of a molded article made of the polyester elastomer resin composition and does not easily detach from the surface of the molded article even during water washing and heptane washing, and it is possible to achieve sound resistance after washing and long-term stable abrasion resistance.

Modes for Carrying Out the Invention

[0012] [Polyester Elastomer (A)] The polyester elastomer (A) used in the present invention is composed of a hard segment made of a polyester containing an aromatic dicarboxylic acid and an aliphatic and / or alicyclic diol as constituent components, and at least one soft segment selected from an aliphatic polyether, an aliphatic polyester, and an aliphatic polycarbonate.

[0013] ​The aromatic dicarboxylic acids that constitute the polyester of the hard segment are widely used ordinary aromatic dicarboxylic acids and are not particularly limited. However, as the main aromatic dicarboxylic acids, terephthalic acid or naphthalenedicarboxylic acid (2,6-naphthalenedicarboxylic acid is preferred among the isomers) is desirably used. The content of these aromatic dicarboxylic acids is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and may even be 100 mol% in all the dicarboxylic acids that constitute the polyester of the hard segment. As the dicarboxylic acid components other than terephthalic acid and naphthalenedicarboxylic acid, there are aromatic dicarboxylic acids such as diphenyldicarboxylic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, and aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, and hydrogenated dimer acid. These acid components are used within a range that does not significantly lower the melting point of the polyester elastomer (A), and the amount thereof is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, and may even be 0 mol% of all the acid components. When these dicarboxylic acids are used as raw materials for the polyester elastomer, they may be in the form of ester bodies of the dicarboxylic acids. For example, as raw materials, terephthalic acid can also be used, and dimethyl terephthalate can also be used.

[0014] The aliphatic or alicyclic diols that constitute the polyester of the hard segment are widely used ordinary aliphatic or alicyclic diols and are not particularly limited. However, it is desirably mainly alkylene glycols having 2 to 8 carbon atoms. Specifically, ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, etc. can be mentioned. Among these, 1,4-butanediol or 1,4-cyclohexanedimethanol is preferred, and 1,4-butanediol is more preferred.

[0015] As components constituting the polyester of the above-mentioned hard segment, those composed of butylene terephthalate units (units composed of terephthalic acid and 1,4-butanediol) or butylene naphthalate units (units composed of 2,6-naphthalenedicarboxylic acid and 1,4-butanediol) are preferable from the viewpoints of physical properties, moldability, and cost performance.

[0016] The soft segment is at least one selected from aliphatic polyethers, aliphatic polyesters, and aliphatic polycarbonates. Examples of the aliphatic polyether include poly(ethylene oxide) glycol, poly(propylene oxide) glycol, poly(tetramethylene oxide) glycol, poly(hexamethylene oxide) glycol, poly(trimethylene oxide) glycol, a copolymer of ethylene oxide and propylene oxide, an ethylene oxide adduct of poly(propylene oxide) glycol, a copolymer of ethylene oxide and tetrahydrofuran, and the like.

[0017] Examples of the aliphatic polyester include poly(ε-caprolactone), poly(enantholactone), polycaprylolactone, polybutylene adipate, and the like. Among these aliphatic polyethers and / or aliphatic polyesters, poly(tetramethylene oxide) glycol, an ethylene oxide adduct of poly(propylene oxide) glycol, poly(ε-caprolactone), polybutylene adipate, and the like are preferable from the viewpoint of the elastic properties of the obtained polyester elastomer (A), and among them, poly(tetramethylene oxide) glycol is particularly preferable.

[0018] In addition, the aliphatic polycarbonate preferably mainly consists of aliphatic diol residues having 2 to 12 carbon atoms. Examples of these aliphatic diols include ethylene glycol, 1,3 - propylene glycol, 1,4 - butanediol, 1,5 - pentanediol, 1,6 - hexanediol, 1,8 - octanediol, 2,2 - dimethyl - 1,3 - propanediol, 3 - methyl - 1,5 - pentanediol, 2,4 - diethyl - 1,5 - pentanediol, 1,9 - nonanediol, 2 - methyl - 1,8 - octanediol, and the like. Particularly, aliphatic diols having 5 to 12 carbon atoms are preferred from the viewpoints of the flexibility and low - temperature properties of the resulting polyester elastomer. These components may be used alone or in combination of two or more as necessary based on the examples described below.

[0019] As the aliphatic polycarbonate diol, those having a low melting point (for example, 70°C or lower) and a low glass transition temperature are preferred. Generally, the aliphatic polycarbonate diol composed of 1,6 - hexanediol, which is used to form the soft segment of the polyester elastomer, has a low glass transition temperature of around - 60°C and a melting point of around 50°C, so it has good low - temperature properties. In addition, for example, an aliphatic polycarbonate diol obtained by copolymerizing an appropriate amount of 3 - methyl - 1,5 - pentanediol with the above - mentioned aliphatic polycarbonate diol has a slightly higher glass transition point than the original aliphatic polycarbonate diol, but its melting point decreases or becomes amorphous, so it corresponds to an aliphatic polycarbonate diol with good low - temperature properties. Also, for example, an aliphatic polycarbonate diol composed of 1,9 - nonanediol and 2 - methyl - 1,8 - octanediol has a melting point of about 30°C and a glass transition temperature of around - 70°C, which is sufficiently low, so it corresponds to an aliphatic polycarbonate diol with good low - temperature properties.

[0020] From the viewpoint of solving the problems of the present invention, an aliphatic polyether is preferred as the soft segment of the polyester elastomer (A).

[0021] The polyester elastomer (A) is preferably a copolymer mainly composed of terephthalic acid, 1,4-butanediol, and poly(tetramethylene oxide) glycol. Among the dicarboxylic acid components constituting the polyester elastomer (A), the content of terephthalic acid is preferably 40 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, and particularly preferably 90 mol% or more. Among the glycol components constituting the polyester elastomer (A), the total of 1,4-butanediol and poly(tetramethylene oxide) glycol is preferably 40 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, and particularly preferably 90 mol% or more.

[0022] The number average molecular weight of the poly(tetramethylene oxide) glycol is preferably from 500 to 4000. If the number average molecular weight is less than 500, it may be difficult to exhibit elastomer properties. On the other hand, if the number average molecular weight exceeds 4000, the compatibility with the polyester portion of the hard segment may decrease, and it may be difficult to copolymerize in a block form. The number average molecular weight of the poly(tetramethylene oxide) glycol is more preferably from 800 to 3000, and still more preferably from 1000 to 2500.

[0023] The copolymerization amount of the poly(tetramethylene oxide) glycol is preferably 5 to 50 mol% based on the total glycol components constituting the polyester elastomer (A). The poly(tetramethylene oxide) glycol is more preferably 5 to 30 mol%, still more preferably 5 to 20 mol%, particularly preferably 7 to 18 mol%, and most preferably 8 to 15 mol% based on the total glycol components.

[0024] In the polyester elastomer (A), the mass part ratio of the hard segment to the soft segment is generally preferably in the range of hard segment:soft segment = 30:70 to 95:5, more preferably 40:60 to 90:10, still more preferably 45:55 to 87:13, and particularly preferably 50:50 to 85:15.

[0025] When the reduced viscosity of the polyester elastomer (A) is measured by the measurement method described below, it is preferably 0.5 dl / g or more and 3.5 dl / g or less. If it is less than 0.5 dl / g, the durability as a resin may be low, and if it exceeds 3.5 dl / g, the processability such as injection molding may be insufficient. The reduced viscosity of the polyester elastomer (A) is more preferably 1.0 dl / g or more and 3.0 dl / g or less, and still more preferably 1.5 dl / g or more and 2.8 dl / g or less. Further, the acid value of the polyester elastomer (A) is preferably 200 eq / t or less, and more preferably 50 eq / t or less.

[0026] The melting point of the polyester elastomer (A) is preferably 150 to 230°C, more preferably 175 to 210°C. When the melting point of the polyester elastomer (A) is less than 150°C, it may be due to the large amount of the soft segment and the heat resistance may decrease. When it exceeds 230°C, it may be due to the large amount of the hard segment and the flexibility may decrease.

[0027] The polyester elastomer (A) can be produced by known methods (for example, JP-A-10-182954, WO 2007 / 072748, etc.). For example, a method in which a lower alcohol diester of a dicarboxylic acid, an excessive amount of a low molecular weight glycol, and a soft segment component are subjected to a transesterification reaction in the presence of a catalyst, and the resulting reaction product is polycondensed; or a method in which a dicarboxylic acid, an excessive amount of a glycol, and a soft segment component are subjected to an esterification reaction in the presence of a catalyst, and the resulting reaction product is polycondensed; further, a method in which a hard segment is prepared in advance, a soft segment component is added thereto, and randomization is carried out by a transesterification reaction; a method in which a hard segment and a soft segment are connected by a chain linking agent; and when poly(ε-caprolactone) is used as the soft segment, an ε-caprolactone monomer may be added to the hard segment by an addition reaction. Any method may be employed.

[0028] [Polyoxytetramethylene polyoxyethylene glycol (B)] The polyoxytetramethylene polyoxyethylene glycol (B) used in the present invention is used as a lubricant to improve friction and wear characteristics. The polyoxytetramethylene polyoxyethylene glycol (B) is a polyoxyalkylene glycol compound, and the alkylene oxide unit is a compound composed of a tetramethylene oxide unit and an ethylene oxide unit. The number average molecular weight of the polyoxytetramethylene polyoxyethylene glycol (B) is preferably from 800 to 4000, more preferably from 1200 to 4000, and still more preferably from 1500 to 3500. If the number average molecular weight is less than the above lower limit, the rate at which the lubricant precipitates (bleeds out) on the surface of the molded product is too fast, and there is a risk that the lubricant will be easily scraped off from the surface of the molded product during the wear test. In other words, if the number average molecular weight is at least the above lower limit, the rate at which the lubricant precipitates on the surface of the molded product is moderately fast, and the lubricant will not be easily scraped off from the surface of the molded product during the wear test. In particular, when the number average molecular weight is 1200 or more, this effect can be more strongly exhibited. If the number average molecular weight exceeds the above upper limit, the rate at which the lubricant precipitates on the surface of the molded product is too slow, and there is a risk that the wear resistance and sound resistance cannot be sufficiently exhibited. The number average molecular weight can be measured by the method described in the Examples section below.

[0029] As the polyoxytetramethylene polyoxyethylene glycol (B), those represented by the following formula (1) can preferably be used.

[0030]

Chemical formula

[0031] In formula (1), a, b, and n represent integers of 1 or more. (However, the values of a and b may be different for each repetition within the brackets.) At this time, the ratio of the tetramethylene oxide unit to the ethylene oxide unit (tetramethylene oxide unit:ethylene oxide unit) is preferably from 10:90 to 90:10 (molar ratio), and more preferably from 30:70 to 60:40 (molar ratio). Further, the tetramethylene oxide unit and the ethylene oxide unit are preferably copolymerized randomly.

[0032] The blending amount of polyoxytetramethylene polyoxyethylene glycol (B) can vary depending on the affinity with the polyester elastomer (A) used or the required properties of the finally obtained composition. Two or more types of this polyoxytetramethylene polyoxyethylene glycol (B) may be used in combination, or it may be used in combination with other lubricant components. The blending amounts of the respective components described hereinafter are the contents in the polyester elastomer resin composition.

[0033] The blending amount of polyoxytetramethylene polyoxyethylene glycol (B) is 0.1 part by mass to 5 parts by mass, preferably 0.3 part by mass to 5 parts by mass, and more preferably 0.8 part by mass to 4 parts by mass with respect to 100 parts by mass of the above polyester elastomer (A). If it is less than 0.1 part by mass, the effects obtained by adding polyoxytetramethylene polyoxyethylene glycol (B) (effects of reducing frictional noise and wear amount) may not be significantly exhibited. On the other hand, if it exceeds 5 parts by mass, the melt viscosity of the polyester elastomer may be significantly decreased and molding may not be possible, the surface hardness and mechanical properties of the molded product may be deteriorated, polyoxytetramethylene polyoxyethylene glycol (B) may ooze out significantly from the surface of the molded body, deteriorating the appearance, or scattering to peripheral parts, etc., and adverse effects may appear.

[0034] Polyoxytetramethylene polyoxyethylene glycol (B) is an aggregate of many types of molecules with different properties at the molecular level, so it tends to gradually bleed out from the polyester elastomer and can exhibit the effects of wear resistance and sound absorption over a long period of time.

[0035] The reason why polyoxytetramethylene polyoxyethylene glycol (B) is not removed from the surface of the molded article during water washing is considered as follows. The tetramethylene oxide unit of polyoxytetramethylene polyoxyethylene glycol (B) has excellent compatibility with the polyester elastomer (A). On the other hand, the ethylene oxide unit of polyoxytetramethylene polyoxyethylene glycol (B) has poor compatibility with the polyester elastomer (A). Therefore, it is considered that due to the appropriate interaction between the polyester elastomer (A) and polyoxytetramethylene polyoxyethylene glycol (B), the lubricant stably bleeds out to the surface layer of the molded article, and due to the appropriate interaction, the lubricant exhibits the effect of remaining even during water washing.

[0036] The reason why polyoxytetramethylene polyoxyethylene glycol (B) is not removed from the surface of the molded article during heptane washing is considered as follows. The ethylene oxide unit of polyoxytetramethylene polyoxyethylene glycol (B) has a high ether group ratio in the alkylene oxide unit and is more polar compared to the tetramethylene oxide unit. Therefore, its solubility in heptane is low, and it is considered that the lubricant exhibits the effect of remaining even during heptane washing.

[0037] [Polyamide resin (C)] The polyamide resin (C) optionally used in the present invention has a role of improving the heat aging resistance of the polyester elastomer. The polyamide resin (C) is a polymer compound having an amide bond in the molecular chain, and is a diamine having an aliphatic hydrocarbon group having 2 to 20 carbon atoms or a substituted aliphatic hydrocarbon group thereof, or an aromatic hydrocarbon group having 6 to 16 carbon atoms or a substituted aromatic hydrocarbon group thereof, and an aliphatic hydrocarbon group having 2 to 20 carbon atoms or a substituted aliphatic hydrocarbon group thereof, or an aromatic hydrocarbon group having 6 to 16 carbon atoms or a substituted aromatic hydrocarbon group thereof. Examples thereof include polyamides obtained from dicarboxylic acids, polymers obtained from lactams, polymers obtained from ω-aminocarboxylic acids, and the like. For example, polymers of salts obtained by reacting adipic acid, sebacic acid, linoleic acid, dodecanedioic acid, etc. with ethylenediamine, hexamethylenediamine, metaxylylenediamine, etc. may be mentioned, and these copolymers or two or more thereof may be used in combination. Specifically, polyamide 4, polyamide 6, polyamide 7, polyamide 8, polyamide 9, polyamide 11, polyamide 12 obtained from lactam or ω-aminocarboxylic acid, polyamide 66, polyamide 69, polyamide 610, polyamide 611, polyamide 612, polyamide 6T, polyamide 6I, polyamide MXD6 obtained from diamine and dicarboxylic acid, and copolymers thereof, such as polyamide 6 / 66, polyamide 6 / 610, polyamide 6 / 6T, polyamide 6I / 6T, polyamide 6 / 66 / 12, etc. Among these polyamide resins, when polyamide 6 and / or a binary or ternary or higher copolymer polyamide resin is used, a more excellent effect can be exhibited. The polyamide resin (C) is more preferably a binary or ternary or higher copolymer polyamide resin.

[0038] The polyamide resin (C) preferably has an amine value of 50 to 2000 eq / t. When the amine value is within the above range, the effect of improving the heat aging resistance of the polyester elastomer becomes greater. The amine value is more preferably 70 to 1000 eq / t, still more preferably 100 to 700 eq / t, and particularly preferably 100 to 550 eq / t.

[0039] The blending amount of the polyamide resin (C) is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the thermoplastic polyester elastomer (A). If the polyamide resin (C) is more than the above range, the original properties of the polyester elastomer (A) may be impaired. If it is less than the above range, the effect of improving heat aging resistance is small. The blending amount of the polyamide resin (C) is more preferably 1 to 7 parts by mass, and even more preferably 1 to 3 parts by mass with respect to 100 parts by mass of the polyester elastomer (A).

[0040] [Thickener (D)] The thickener (D) optionally used in the present invention is a reactive compound having a functional group capable of reacting with a hydroxyl group or a carboxyl group of the polyester elastomer (A) (hereinafter sometimes simply referred to as a reactive compound). The functional group is preferably at least one selected from an epoxy group (glycidyl group), an acid anhydride group, a carbodiimide group, and an isocyanate group, and preferably contains two or more per molecule. The functional group is more preferably an epoxy group (glycidyl group) or a carbodiimide group. The thickener (D) is particularly preferably an epoxy compound and / or a carbodiimide compound.

[0041] The epoxy compound is a polyfunctional epoxy compound having two or more epoxy groups. Specifically, examples include 1,6-dihydroxynaphthalene diglycidyl ether having two epoxy groups, 1,3-bis(oxiranylmethoxy)benzene, 1,3,5-tris(2,3-epoxypropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and diglycerol triglycidyl ether having three epoxy groups, 1-chloro-2,3-epoxypropane·formaldehyde·2,7-naphthalenediol polycondensate and pentaerythritol polyglycidyl ether having four epoxy groups. Among them, it is preferably a polyfunctional epoxy compound having heat resistance in the skeleton. In particular, a bifunctional or tetrafunctional epoxy compound having a naphthalene structure in the skeleton, or a trifunctional epoxy compound having a triazine structure in the skeleton is preferable. Considering the degree of increase in the solution viscosity of the polyester elastomer (A), the effect of efficiently reducing the acid value of the polyester elastomer (A), and the degree of occurrence of gelation due to aggregation and solidification of the epoxy itself, a bifunctional or trifunctional epoxy compound is preferable.

[0042] The carbodiimide compound may be a polycarbodiimide compound having two or more carbodiimide groups (-N=C=N- structure) in one molecule. Examples include aliphatic polycarbodiimide compounds, alicyclic polycarbodiimide compounds, aromatic polycarbodiimide compounds, and copolymers thereof. An aliphatic polycarbodiimide compound or an alicyclic polycarbodiimide compound is preferable.

[0043] The polycarbodiimide compound can be obtained, for example, by the decarboxylation reaction of a diisocyanate compound. Examples of the diisocyanate compound that can be used here include 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane diisocyanate, tetramethylxylylene diisocyanate, 1,3,5-triisopropylphenylene-2,4-diisocyanate, and the like. These may be used alone or two or more of them may be copolymerized and used. Further, a branched structure may be introduced, or a functional group other than a carbodiimide group or an isocyanate group may be introduced by copolymerization. Furthermore, the terminal isocyanate can be used as it is, but the degree of polymerization may be controlled by reacting the terminal isocyanate, or a part of the terminal isocyanate may be blocked.

[0044] As the polycarbodiimide compound, alicyclic polycarbodiimides derived from, in particular, dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, etc. are preferable, and polycarbodiimides derived from dicyclohexylmethane diisocyanate or isophorone diisocyanate are particularly good.

[0045] It is preferable that the polycarbodiimide compound contains 2 to 50 carbodiimide groups per molecule from the viewpoints of stability and handleability. More preferably, it contains 5 to 30 carbodiimide groups per molecule. The number of carbodiimides (i.e., the number of carbodiimide groups) in the polycarbodiimide molecule corresponds to the degree of polymerization in the case of a polycarbodiimide obtained from a diisocyanate compound. For example, the degree of polymerization of a polycarbodiimide obtained by connecting 21 diisocyanate compounds in a chain is 20, and the number of carbodiimide groups in the molecular chain is 20. Usually, the polycarbodiimide compound is a mixture of molecules of various lengths, and the number of carbodiimide groups is represented by an average value. Having the number of carbodiimide groups within the above range and being solid near room temperature enables powdering, so it is excellent in workability and compatibility during mixing with the polyester elastomer (A), and is also preferable in terms of uniform reactivity and bleed-out resistance. The number of carbodiimide groups can be measured, for example, using a conventional method (a method of dissolving with an amine and performing back-titration with hydrochloric acid).

[0046] It is preferable that the polycarbodiimide compound has an isocyanate group at the terminal and the isocyanate group content is 0.5 to 4% by mass from the viewpoints of stability and handleability. More preferably, the isocyanate group content is 1 to 3% by mass. In particular, it is preferable that the polycarbodiimide is derived from dicyclohexylmethane diisocyanate or isophorone diisocyanate and has the isocyanate group content within the above range. The isocyanate group content can be measured using a conventional method (a method of dissolving with an amine and performing back-titration with hydrochloric acid).

[0047] The compounding amount of the thickener (D) is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the polyester elastomer (A). If it is less than 0.1 part by mass, the target molecular chain extension effect is insufficient. If it exceeds 5 parts by mass, the thickening effect becomes excessive, which tends to have an adverse effect on moldability or affect the mechanical properties of the molded product. When the thickener (D) is an epoxy compound, if it exceeds 5 parts by mass, unevenness may occur on the surface of the molded product due to the aggregation and curing of the epoxy compound. When the thickener (D) is a carbodiimide compound, if it exceeds 5 parts by mass, hydrolysis of the polyester elastomer (A) may occur due to the basicity of the polycarbodiimide compound, which tends to affect the mechanical properties.

[0048] As the thickener (D), either an epoxy compound or a carbodiimide compound may be used. Also, the thickener (D) can be used in combination with an epoxy compound and a carbodiimide compound. In that case, the upper limit of each content is the apportioned content according to the content ratio of the epoxy compound and the carbodiimide compound. For example, when using an epoxy compound and a carbodiimide compound in a mass ratio of 50:50, the upper limit of the epoxy compound may be 2.5 parts by mass and the upper limit of the carbodiimide compound may be 2.5 parts by mass.

[0049] [Other Additives] In the resin composition of the present invention, general-purpose antioxidants such as aromatic amine-based, hindered phenol-based, phosphorus-based, and sulfur-based antioxidants can be blended in addition to the above components (A) to (D). Two or more of these may be used in combination. Specific examples of the aromatic amine-based antioxidant include phenylnaphthylamine, 4,4'-dimethoxydiphenylamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and 4-isopropoxydiphenylamine.

[0050] As the hindered phenol antioxidant, general-purpose compounds can be used, but those with a molecular weight of 500 or more such as N,N'-hexamethylene-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamic acid amide) and tetrakis[methylene-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane are preferred because they are less likely to volatilize in a high-temperature atmosphere.

[0051] As the phosphorus antioxidant, compounds containing phosphorus such as phosphoric acid, phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, polyphosphonates, diphosphite compounds, etc. can be mentioned. Specific examples include triphenyl phosphite, diphenyl decyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, etc.

[0052] As the sulfur antioxidant, compounds containing sulfur such as thioether-based, dithiocarboxylate-based, mercaptobenzimidazole-based, thiocarbanyl amide-based, thiodipropionate-based, etc. can be mentioned. Specific examples include dilauryl thiodipropionate, distearyl thiodipropionate, didodecyl thiodipropionate, ditetradecyl thiodipropionate, dioctadecyl thiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, trilauryl trithiophosphite, etc. In particular, thioether-based antioxidants having a thioether structure can be preferably used because they receive oxygen from the oxidized substance and reduce it.

[0053] The compounding amount of each of the above antioxidants is preferably 0.01 to 3 parts by mass, more preferably 0.05 to 2 parts by mass, and still more preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the polyester elastomer (A).

[0054] As a method for determining the composition and composition ratio of the polyester elastomer resin composition used in the present invention, a sample is dissolved in a solvent such as deuterated chloroform and measured. 1 It is also possible to calculate from the proton integration ratio of 1H-NMR.

[0055] Furthermore, when weather resistance is required for the resin composition of the present invention, it is preferable to add an ultraviolet absorber and / or a hindered amine compound. For example, benzophenone-based, benzotriazole-based, triazole-based, nickel-based, and salicylic-based light stabilizers can be used. The addition amount is preferably 0.1% or more and 5% or less based on the mass of the resin composition.

[0056] Various other additives can be blended in the polyester elastomer resin composition of the present invention. As additives, resins, inorganic fillers, stabilizers, and anti-aging agents other than those described above can be added within a range that does not impair the characteristics of the present invention. Also, as other additives, coloring pigments, inorganic and organic fillers, coupling agents, tackiness improvers, quenchers, stabilizers such as metal deactivators, flame retardants, etc. can be added. The total compounding amount of these various additives is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less with respect to 100 parts by mass of the polyester elastomer (A).

[0057] The MFR of the polyester elastomer resin composition of the present invention is not particularly limited, but for the purpose of obtaining a general injection molded product, it is preferably 0.1 to 30 g / 10 min. However, from the viewpoint of further improving heat aging resistance and blow moldability, it is preferably 3 g / 10 min or less, and more preferably 0.1 to 3 g / 10 min. The MFR can be measured by the method described in the Examples section below.

[0058] As a method for producing the resin composition of the present invention, there is a method in which each component is melt-kneaded using a single-screw or twin-screw screw-type melt-kneading machine, or a normal mixer for thermoplastic resins typified by a kneader-type heating machine, and then pelletized by a granulation process.

Examples

[0059] In order to explain the present invention in more detail, examples are given below, but the present invention is not limited by the examples. Each measured value described in the examples was measured by the following method.

[0060] Melting point: Using a differential scanning calorimeter "DSC220 type" manufactured by Seiko Instruments Inc., 5 mg of the measurement sample was placed in an aluminum pan, covered with a lid and sealed, and after holding at 250 °C for 5 minutes to completely melt the sample, it was rapidly cooled with liquid nitrogen, and then measured from -150 °C to 250 °C at a heating rate of 20 °C / min. From the obtained thermogram curve, the endothermic peak temperature was taken as the melting point.

[0061] Reduced viscosity: 0.10 g of the sufficiently dried resin was dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane (mass ratio 6 / 4) and measured at 30 °C with an Ubbelohde viscometer.

[0062] Acid value: 0.2 g of the sample was precisely weighed, dissolved in 20 ml of chloroform, and titrated with 0.01 N potassium hydroxide (ethanol solution). Phenolphthalein was used as the indicator.

[0063] Amine value (eq / ton): 3 g of the sample was weighed, and for the solution dissolved in 80 ml of m-cresol, using "AT-500N" manufactured by Kyoto Electronics Industry Co., Ltd., it was titrated by potentiometric titration using a 0.05 mol / l perchloric acid methanol solution as the titrant.

[0064] Relative viscosity: The method for measuring the relative viscosity of polyamide resin generally includes methods using three types of solvents, namely metacresol, 96% sulfuric acid, and 90% formic acid, depending on the type of solvent used for dissolution. However, the relative viscosity of the polyamide resin (C) in the present invention was measured using a 98% sulfuric acid solution (polyamide resin concentration 1 g / dl, temperature 25°C).

[0065] Number average molecular weight of polyoxytetramethylene polyoxyethylene glycol (B): The sample was dissolved in deuterated chloroform (CDCl3) / trifluoroacetic acid (TFA) = 85 / 15 (volume ratio). 1 The number average molecular weight was calculated from the spectral ratio of tetramethylene oxide and ethylene oxide obtained by 1H-NMR and the amount of their terminals. Regarding (B'-1) used in the comparative example, it was also measured by this method.

[0066] The following were used as raw materials. [Polyester elastomer (A)] · (A-1) Polyester elastomer A1 According to the method described in Reference Example 1 of Paragraph 0017 of JP-A-9-59491, polyester elastomer A1 with terephthalic acid / 1,4-butanediol / poly(tetramethylene oxide) glycol (PTMG; number average molecular weight 1500) at 100 / 88 / 12 (molar ratio) was produced. The melting point of this polyester elastomer A1 was 197°C, the reduced viscosity was 1.86 dl / g, and the acid value was 38 eq / t. · (A-2) Polyester elastomer A2 According to the method described in Reference Example 1 of Paragraph 0017 of JP-A-9-59491, polyester elastomer A2 with terephthalic acid / 1,4-butanediol / poly(tetramethylene oxide) glycol (PTMG; number average molecular weight 2000) at 100 / 90 / 10 (molar ratio) was produced. The melting point of this polyester elastomer A2 was 205°C, the reduced viscosity was 2.15 dl / g, and the acid value was 35 eq / t.

[0067] [Polyoxytetramethylene Polyoxyethylene Glycol (B)] · (B-1) Polyserin DC-1800E (manufactured by NOF Corporation, number average molecular weight 1800, tetramethylene oxide unit / ethylene oxide unit = 46 / 54 [molar ratio]) · (B-2) Polyserin DC-3000E (manufactured by NOF Corporation, number average molecular weight 3000, tetramethylene oxide unit / ethylene oxide unit = 53 / 47 [molar ratio]) · (B-3) Polyserin DC-1100 (manufactured by NOF Corporation, number average molecular weight 1000, tetramethylene oxide unit / ethylene oxide unit = 35 / 65 [molar ratio])

[0068] [Other Polyether Glycol Compounds] · (B’-1) Polyserin DCB-2000 (polyoxytetramethylene polyoxypropylene glycol) (manufactured by NOF Corporation, number average molecular weight 2000, tetramethylene oxide unit / propylene oxide unit = 61:39 [molar ratio]) · (B’-2) PEG-1540 (polyethylene glycol) (manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight 1450) · (B’-3) PTMG3000 (poly(tetramethylene oxide) glycol) (manufactured by Mitsubishi Chemical Corporation, number average molecular weight 3000)

[0069] [Polyamide Resin (C)] · (C-1) Polyamide Resin C1 (polyamide 6 / 66 / 12) (relative viscosity 1.3, amine value 490 eq / t)

[0070] [Thickener (D)] · (D-1) TEPIC-S (triazine skeleton-containing trifunctional epoxy compound) (manufactured by Nissan Chemical Industries, Ltd.) · (D-2) Carbodilite HMV-15CA (alicyclic polycarbodiimide compound) (manufactured by Nisshinbo Industries, Inc.)

[0071] [Other Additives] · Aromatic amine antioxidant: Nonflex DCD (manufactured by Ouchi Shinko Chemical Co., Ltd.) (4,4'-bis(α,α-dimethylbenzyl)diphenylamine) · Hindered phenol antioxidant: Irganox 1010 (manufactured by BASF) · Hindered phenol antioxidant: Irganox 1098 (manufactured by BASF) · Sulfur antioxidant: Lasmid LG (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (dilauryl thiodipropionate)

[0072] Examples 1 to 8, Comparative Examples 1 to 6 Each of the above components was dry-blended at the ratios shown in Table 1 and kneaded and pelletized using a twin-screw extruder. Using the pellets of this polyester elastomer resin composition, the following evaluations were conducted. Also, regarding the test pieces used for surface hardness, bleed amount, lubricant residual rate by water washing, lubricant residual rate by heptane washing, abrasion test, and squeaking test, injection molded products (100-angle test pieces: width 100 mm, length 100 mm, thickness 2.0 mm) were produced using an injection molding machine at a cylinder temperature of 240°C and a mold temperature of 50°C. The results are shown in Table 1.

[0073] Surface hardness: In accordance with the test method described in ISO 48-4, the surface hardness was measured in an environment at 23°C. Three 100-angle test pieces were stacked, the needle tip was dropped, and the value 15 seconds after the contact between the test piece and the needle tip was read to measure the surface hardness.

[0074] Melt viscosity (MFR): In accordance with the test method (Method A) described in JIS K7210, the melt flow rate (MFR: g / 10 min) at a measurement temperature of 230°C and a load of 2160 g was measured. A composition with a moisture content of 0.1 mass% or less was used for the measurement.

[0075] Bleed amount (23°C): The 100-corner test pieces were left standing in an environment of 23°C / 50%RH for 2 weeks. Then, the mass of the molded product was measured. The surface of the molded product was carefully wiped off with a Kimwipe once, and the mass of the molded product was measured again. The bleed amount of the lubricant was measured from the mass difference before and after wiping.

[0076] Wear test (presence or absence of wear powder generation): The 100-corner test pieces were left standing in an environment of 23°C / 50%RH for 2 weeks. Then, the thrust wear test described in JIS K7213 was carried out to confirm the presence or absence of wear powder generation on the surface of the molded product, and it was evaluated according to the following criteria. The cylindrical test pieces used in the thrust wear test were SUS-65C, and the sliding test was carried out under a load of 1.0 MPa, a sliding speed of 100 rpm, and a test time of 60 minutes. No wear powder generation is observed on the surface of the molded product: A Slight wear powder generation is observed on the surface of the molded product: B Wear powder generation is observed on the surface of the molded product: C

[0077] Lubricant residue rate by water washing: The 100-corner test pieces were left standing in an environment of 23°C / 50%RH for 2 weeks. Then, water was sprayed on the molded product, and wiping was carried out using a thrust wear testing machine. A waste cloth was sandwiched between the cylindrical test piece SUS-65C and the molded product, and it was carried out under a load of 0.5 MPa, a sliding speed of 50 rpm, and a wiping time of 5 minutes. The surfaces of the molded product before and after wiping were compared by infrared absorption spectroscopy (IR), and it was confirmed as the lubricant residue rate whether the peak derived from the lubricant remained after wiping. Specifically, the lubricant residue rate is shown by [(absorbance before washing) - (absorbance after washing)] / [(absorbance before washing) - (absorbance derived from polyester elastomer)] × 100 in the region of 1360 - 1370 cm ―1 .

[0078] Lubricant residue rate by heptane washing: The 100-corner test pieces were left standing in an environment of 23°C / 50%RH for 2 weeks. Then, heptane was sprayed onto the molded products, and wiping was carried out using a thrust wear tester. A cloth was sandwiched between the cylindrical test piece SUS-65C and the molded product, and the test was carried out at a load of 0.5 MPa, a sliding speed of 50 rpm, and a wiping time of 5 minutes. The surfaces of the molded products before and after wiping were compared by infrared absorption spectroscopy (IR), and it was confirmed as the lubricant residue rate whether peaks derived from the lubricant remained after wiping. Specifically, the lubricant residue rate is [(absorbance before cleaning) - (absorbance after cleaning)] / [(absorbance before cleaning) - (absorbance derived from the polyester elastomer)] × 100 in the region of 1360~1370 cm ―1 as shown.

[0079] Rattling test (presence or absence of rattling): The 100-corner test pieces were left standing in an environment of 23°C / 50%RH for 2 weeks. Then, water or heptane was sprayed onto the molded products, and wiping was carried out using a thrust wear tester. A cloth was sandwiched between the cylindrical test piece SUS-65C and the molded product, and the test was carried out at a load of 0.5 MPa, a sliding speed of 50 rpm, and a wiping time of 5 minutes. Further, water was dropped onto the surface of the molded product after wiping, and a thrust wear test was carried out to confirm the presence or absence of rattling. At this time, as the cylindrical test piece used in the thrust wear test, a test piece obtained by injection molding the same resin as the 100-corner test piece at a cylinder temperature of 240°C was used, and when the sliding test was carried out at a load of 0.5 MPa, a sliding speed of 50 rpm, and a test time of 5 minutes, the generated sound was measured with a noise meter NL-20 manufactured by Lion Corporation.

[0080] Tensile test after heat aging (elongation at break): Test pieces were prepared by punching out in the shape of a JIS No. 3 dumbbell in a direction perpendicular to the resin flow direction of an injection molded product (width 100 mm, length 100 mm, thickness 2.0 mm) manufactured at a cylinder temperature of 240°C and a mold temperature of 50°C. They were annealed in a hot air dryer at 150°C for 500 hours, and then the elongation at break was measured according to JIS K6251:2010.

[0081] Flexural fatigue test: Using a dematcher flexure crack tester BE-102 (manufactured by Tester Sangyo Co., Ltd.), for the following specified test pieces, in an atmosphere of 130 °C, the distance between the chucks was set to 75 mm and 19 mm, and repeated flexure was carried out at a speed of 300 times / min, and the flexural fatigue resistance was evaluated by the number of times until fracture. As the test pieces, injection molded products (width 20 mm, length 100 mm, thickness 3.6 mm, with a groove of R2.4 over the entire 20 mm width at the central part in the length direction) produced at a cylinder temperature of 240 °C and a mold temperature of 50 °C were used.

[0082]

Table 1

[0083] In Examples 1 to 8, by blending a specific liquid lubricant polyoxytetramethylene polyoxyethylene glycol (B) into the polyester elastomer, while maintaining the mechanical properties, a resin composition having bleed-out properties, long-term stable wear resistance, high lubricant residual rate after water washing and after heptane washing, and sound resistance is obtained. In particular, in Examples 1 to 3 and 5 to 8, compared with Example 4, the molecular weight of polyoxytetramethylene polyoxyethylene glycol (B) is higher, and better results are obtained in the wear test. In Examples 6 to 8, by further blending a polyamide resin (C), a resin composition having improved heat aging resistance while maintaining sound resistance is obtained. In Examples 7 and 8, by further blending a thickener (D), a resin composition having a low MFR and improved flexural fatigue resistance is obtained.

[0084] In Comparative Example 1, since no lubricant component is added, bleed-out of the lubricant on the surface of the molded product does not occur, the wear resistance is poor, and sound occurs in both cases after water washing and after heptane washing. Since it does not contain a lubricant component, the lubricant residual property by water washing and the lubricant residual property by heptane washing were not evaluated.

[0085] Comparative Example 2 is a case where polyoxytetramethylene polyoxypropylene glycol (DCB-1000) with a different copolymer component is added as a lubricant component. Since there is no ethylene oxide unit, its compatibility with the polyester elastomer is high, but the bleed amount is insufficient. Furthermore, since it is easily soluble in heptane, the lubricant residual property after heptane washing is low, and rattling occurs.

[0086] Comparative Example 3 is a case where polyethylene glycol (PEG-1540) is added as a lubricant component. Its compatibility with the polyester elastomer is low, and the bleed amount is large. Since this lubricant is a highly polar polyether, the lubricant residual property after water washing is low, and rattling occurs. Also, although the lubricant residual property after heptane washing is high, rattling occurs even in the rattling test after heptane washing because a thrust wear test is carried out by dropping water.

[0087] Comparative Example 4 is a case where poly(tetramethylene oxide) glycol (PTMG3000) is added as a lubricant component. Since its compatibility with the polyester elastomer is too high, the bleed amount is small. Also, the lubricant residual property after heptane washing is low, and rattling occurs.

[0088] Comparative Example 5 is a case where polyethylene glycol (PEG-1540) and poly(tetramethylene oxide) glycol (PTMG3000) are added as lubricant components, and there is no tetramethylene oxide unit / ethylene oxide unit in one molecule, and they are added as separate compounds. Similar to Comparative Examples 3 and 4, the lubricant residual property after heptane washing is low, and rattling occurs.

[0089] Comparative Example 6 is a case where a large amount of polyoxytetramethylene polyoxyethylene glycol (DC-1800E) is added as a lubricant component. Although it can exhibit anti-rattling properties, the surface hardness of the molded product itself decreases significantly and the MFR increases significantly, resulting in a significant decrease in mechanical properties.

Industrial Applicability

[0090] In the present invention, it is possible to continuously obtain wear resistance over a long period of time, the lubricant is not removed even in the water washing or heptane washing of the molded product, and a polyester elastomer resin composition excellent in sound rattling property after washing can be provided. Therefore, it is useful for applications such as automobiles and home appliance parts that require the above excellent properties. In particular, it is useful for automotive interior applications that require high slidability and automotive foot area members.

Claims

1. A polyester elastomer resin composition containing 0.1 to 5 parts by mass of polyoxytetramethylene polyoxyethylene glycol (B) with respect to 100 parts by mass of a polyester elastomer (A) composed of a hard segment made of an aromatic dicarboxylic acid and an aliphatic and / or alicyclic diol and at least one soft segment selected from an aliphatic polyether, an aliphatic polyester, and an aliphatic polycarbonate, wherein the number average molecular weight of the polyoxytetramethylene polyoxyethylene glycol (B) is 800 to 4000.

2. The polyester elastomer resin composition according to Claim 1, wherein the ratio of the tetramethylene oxide unit to the ethylene oxide unit of the polyoxytetramethylene polyoxyethylene glycol (B) is 10:90 to 90:10 (molar ratio).

3. The polyester elastomer resin composition according to Claim 1, wherein the soft segment of the polyester elastomer (A) is an aliphatic polyether.

4. The polyester elastomer resin composition according to Claim 1, further containing 0.5 to 10 parts by mass of a polyamide resin (C) with respect to 100 parts by mass of the polyester elastomer (A).

5. The polyester elastomer resin composition according to Claim 1, further containing 0.1 to 5 parts by mass of a thickener (D) with respect to 100 parts by mass of the polyester elastomer (A), wherein the thickener (D) is at least one compound selected from an epoxy compound and a carbodiimide compound.

6. The polyester elastomer resin composition according to Claim 1, wherein the melt flow rate (MFR) value at 230°C and a load of 2.16 kg measured according to the flow test method of thermoplastic plastics specified in JIS K7210 is 3 g / 10 min or less.

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