Thermoplastic polyester elastomer resin composition and molded body thereof

Abstract

The present invention is a thermoplastic polyester elastomer resin composition which can obtain a molded body having good appearance and extremely excellent wear resistance. The thermoplastic polyester elastomer resin composition contains a thermoplastic polyester elastomer resin (A) which is composed of a hard segment composed of a polyester having aromatic dicarboxylic acid and aliphatic and / or alicyclic glycol as a constituent component, and a soft segment selected from at least one of aliphatic polyether, aliphatic polyester and aliphatic polycarbonate. In a molded product obtained by injection molding the thermoplastic polyester elastomer resin composition, the average dispersed area of the silicone-acrylic copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming a matrix is 0.3 μm 2 The following.

Description

Technical Field

[0001] This invention relates to a thermoplastic polyester elastomer resin composition that can yield molded articles with good appearance and extremely excellent abrasion resistance. Background Technology

[0002] To improve the abrasion resistance of resin compositions, methods such as adding long-chain organic acid compounds (e.g., organic acid esters, organic acid salts, organic acid amides) or silicone oils as slip agents are known. In particular, for flexible compositions with a hardness below 60 measured by a D-type durometer, a large amount of slip agent is required to exhibit sufficient abrasion resistance. However, once a large amount of slip agent is added, its poor dispersibility prevents it from fully exhibiting compatibility with the resin. Therefore, over time, the slip agent separates and accumulates near the surface, easily causing problems such as exudation, blooming, and whitening. Furthermore, long-chain organic acid compounds are prone to deterioration at high temperatures and can easily produce discoloration and foreign matter, known as burn marks or scorch marks, during melt molding.

[0003] On the other hand, it is also known to improve abrasion properties by adding solid particles such as silicone powder or Teflon (registered trademark) powder that do not melt even at high temperatures. Solid particles act as fillers, which not only have an adverse effect on formability or surface properties, but also have poor adhesion to the resin components of the composition, so they are easy to peel off from the interface. There is a problem that the strength of the composition itself will decrease once a large amount is used.

[0004] To address this issue, attempts have been made to develop copolymers that combine structural components with good compatibility with resin composition and those that improve wear resistance, for application in various thermoplastic resins. However, while these copolymers exhibit improved heat and weather resistance, they also often show defects such as decreased melt flowability or formability. The reason for this phenomenon is believed to be that graft copolymers or block copolymers with different structures act as quasi-crosslinking points in the thermoplastic resin.

[0005] Patent Document 1 discloses an invention relating to a thermoplastic elastomer composition. The thermoplastic elastomer composition contains an epoxy tackifier relative to a thermoplastic polyester elastomer, the epoxy tackifier comprising a silicone-modified (meth)acrylic polymer and styrene.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2016-79228 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] In Patent Document 1, silicone-modified acrylic polymers were proposed to address the above-mentioned problems. However, it is known that the appearance of molded articles made from thermoplastic polyester elastomer compositions is still insufficient. The object of the present invention is to provide a thermoplastic polyester elastomer resin composition and a molded article made therefrom, which can produce molded articles with better appearance and superior abrasion resistance.

[0011] Technical means to solve the problem

[0012] In order to achieve the above-mentioned objectives, the inventors of this application discovered that by adding a specific silicone-acrylic copolymer to a thermoplastic polyester elastomer, both appearance and wear resistance can be achieved, thus completing the present invention.

[0013] That is, the present invention has the following [1] to [4].

[0014] [1] A thermoplastic polyester elastomer resin composition, characterized in that it comprises a thermoplastic polyester elastomer resin (A) and a silicone-acrylic acid copolymer (B); the thermoplastic polyester elastomer resin (A) is composed of hard segments of polyester consisting of aromatic dicarboxylic acids and aliphatic and / or alicyclic diols, combined with soft segments selected from at least one of aliphatic polyethers, aliphatic polyesters and aliphatic polycarbonates; in the molded article obtained by injection molding the thermoplastic polyester elastomer resin composition, the average dispersion area of ​​the silicone-acrylic acid copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming the matrix is ​​0.3 μm. 2 the following.

[0015] [2] The thermoplastic polyester elastomer resin composition according to [1] is characterized in that the silicone-acrylic copolymer (B) is a graft copolymer in which the main skeleton is silicone and the acrylic polymers on the main skeleton are bonded in a side chain manner.

[0016] [3] The thermoplastic polyester elastomer resin composition according to [1] or [2] is characterized in that the weight reduction rate of the silicone-acrylic copolymer (B) at 250°C is more than 3.3%, as determined by thermogravimetric analysis (TGA).

[0017] [4] A molded article, characterized in that the molded article is made from a thermoplastic polyester elastomer resin composition containing a thermoplastic polyester elastomer resin (A) and a silicone-acrylic acid copolymer (B), wherein the thermoplastic polyester elastomer resin (A) is composed of hard segments of polyesters consisting of aromatic dicarboxylic acids and aliphatic and / or alicyclic diols, combined with soft segments selected from at least one of aliphatic polyethers, aliphatic polyesters and aliphatic polycarbonates; in the molded article, the average dispersion area of ​​the silicone-acrylic acid copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming the matrix is ​​0.3 μm. 2 the following. Detailed Implementation

[0018] The thermoplastic polyester elastomer resin composition of the present invention will be described in detail below.

[0019] The thermoplastic polyester elastomer resin composition of the present invention is a thermoplastic polyester elastomer resin composition containing a thermoplastic polyester elastomer (A) and a silicone-acrylic copolymer (B); in the molded article obtained by injection molding the thermoplastic polyester elastomer resin composition, the average dispersion area of ​​the silicone-acrylic copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming the matrix is ​​0.3 μm. 2 the following.

[0020] Thermoplastic polyester elastomer (A) is composed of hard segments of polyester consisting of aromatic dicarboxylic acids and aliphatic and / or alicyclic diols, combined with soft segments selected from at least one of aliphatic polyethers, aliphatic polyesters and aliphatic polycarbonates.

[0021] The thermoplastic polyester elastomer (A) preferably uses the following hard and soft segments as its main components: hard segments composed of crystalline polyesters consisting of aromatic dicarboxylic acids and aliphatic and / or alicyclic diols, and soft segments selected from at least one of aliphatic polyethers, aliphatic polyesters, and aliphatic polycarbonates, wherein the content of the soft segment component is preferably 95% to 5% by mass. The content of the soft segment component is more preferably 90% to 10% by mass, further preferably 85% to 15% by mass, and particularly preferably 75% to 25% by mass. Furthermore, the thermoplastic polyester elastomer (A) can be adjusted to the above-mentioned soft segment content by using two or more soft segment components with different contents.

[0022] In the thermoplastic polyester elastomer (A), the aromatic dicarboxylic acid constituting the hard segment of the polyester can be any commonly used aromatic dicarboxylic acid, although there are no particular limitations. However, terephthalic acid or naphthalic acid is preferred as the main aromatic dicarboxylic acid. Among the isomers of naphthalic acid, 2,6-naphthalic acid is preferred. Other components include: aromatic dicarboxylic acids such as diphenyl dicarboxylic acid, isophthalic acid, and sodium isophthalate-5-sulfonate; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and tetrahydrophthalic anhydride; and aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebaceous acid, dodecanoic acid, dimer acid, and hydrogenated dimer acid. These components can be used within a range that does not significantly reduce the melting point of the resin, and their amount is less than 35 mol% of the total acid components, preferably less than 30 mol%.

[0023] Furthermore, in the thermoplastic polyester elastomer (A), the aliphatic or alicyclic diol constituting the hard segment of the polyester can be a wide variety of commonly used aliphatic or alicyclic diols, although there are no particular limitations, but alkylene diols with 2 to 8 carbon atoms are mainly preferred. Specifically, examples include: ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,4-cyclohexanediethanol. 1,4-Butanediol and 1,4-cyclohexanediethanol are most preferred.

[0024] From the perspective of physical properties, formability, and cost-effectiveness, polyesters composed of butylene terephthalate units (structural units composed of terephthalic acid and 1,4-butanediol) or butylene dinaphthalate units (structural units composed of 2,6-naphthalic acid and 1,4-butanediol) are preferred as components constituting the hard segments of the aforementioned polyester.

[0025] The soft segments of the thermoplastic polyester elastomer (A) used in this invention are selected from at least one of aliphatic polyethers, aliphatic polyesters and aliphatic polycarbonates.

[0026] Examples of aliphatic polyethers include: poly(ethylene oxide) glycol, poly(propylene oxide) glycol, poly(tetramethylene ether) glycol, poly(hexamethylene ether) glycol, poly(trimethylene ether) glycol, copolymers of ethylene oxide and propylene oxide, ethylene oxide addition products of poly(propylene oxide) glycol, and copolymers of ethylene oxide and tetrahydrofuran.

[0027] Among these, from the viewpoint of elastic properties, the ethylene oxide addition products of poly(tetramethylene ether) glycol and poly(propylene oxide) glycol are preferred.

[0028] Examples of aliphatic polyesters include poly(ε-caprolactone), polyheptanolactone, polyoctyl lactone, and polybutylene adipate. Among these, poly(ε-caprolactone) and polybutylene adipate are preferred from the viewpoint of elastic properties.

[0029] As an aliphatic polycarbonate, it is preferable to be composed of aliphatic diol residues having 2 to 12 carbon atoms. Examples of such aliphatic diols include: ethylene glycol, 1,3-propanediol, 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, and 2-methyl-1,8-octanediol. In particular, aliphatic diols having 5 to 12 carbon atoms are preferred from the perspective of the softness and low-temperature properties of the resulting thermoplastic polyester elastomer. These components, based on the examples described below, can be used alone or in combination of two or more as needed.

[0030] As a soft segment constituting the thermoplastic polyester elastomer (A) used in this invention, an aliphatic polycarbonate diol with good low-temperature properties is preferred. Typically, aliphatic polycarbonate diols composed of 1,6-hexanediol, which forms the soft segment of the thermoplastic polyester elastomer, have glass transition temperatures as low as -60°C and melting points of around 50°C, thus exhibiting good low-temperature properties. Furthermore, aliphatic polycarbonate diols obtained by copolymerizing an appropriate amount of 3-methyl-1,5-pentanediol, while having a slightly higher glass transition point than the original aliphatic polycarbonate diol, also exhibit good low-temperature properties due to a lower melting point or becoming amorphous. In addition, for example, aliphatic polycarbonate diols composed of 1,9-nonanediol and 2-methyl-1,8-octanediol have a melting point of around 30°C and a glass transition temperature of around -70°C, which are low enough that they are equivalent to aliphatic polycarbonate diols with good low-temperature properties.

[0031] From the viewpoint of solving the problems of the present invention, aliphatic polyethers are preferred as the soft segments of the thermoplastic polyester elastomer (A) used in the present invention.

[0032] The thermoplastic polyester elastomer (A) used in this invention is preferably a copolymer with terephthalic acid, 1,4-butanediol, and poly(tetramethylene ether) glycol as its main components. Of the dicarboxylic acid components constituting the thermoplastic polyester elastomer (A), terephthalic acid is preferably 40 mol% or more, more preferably 70 mol% or more, further preferably 80 mol% or more, and particularly preferably 90 mol% or more. Of the diol components constituting the thermoplastic polyester elastomer (A), the total amount of 1,4-butanediol and poly(tetramethylene ether) glycol is preferably 40 mol% or more, more preferably 70 mol% or more, further preferably 80 mol% or more, and particularly preferably 90 mol% or more.

[0033] The number-average molecular weight of the poly(tetramethylene ether) glycol is preferably 500 to 4000. If the number-average molecular weight is below 500, it is difficult to exhibit elastomer properties. On the other hand, if the number-average molecular weight exceeds 4000, the compatibility with hard segment components decreases, making block copolymerization difficult. More preferably, the number-average molecular weight of the poly(tetramethylene ether) glycol is 800 to 3000, and even more preferably 1000 to 2500.

[0034] From the viewpoint of maximizing the inventive effect of this application, the specific viscosity of the thermoplastic polyester elastomer (A) is preferably 0.5 to 3.5 dl / g, more preferably 1.0 to 3.0 dl / g.

[0035] Thermoplastic polyester elastomer (A) can be manufactured using methods that are well-known. For example, it can be manufactured by: performing a transesterification reaction on a lower alcohol diester of a dicarboxylic acid, an excess of a low molecular weight diol, and a soft segment component in the presence of a catalyst, followed by polycondensation of the resulting reaction product; or by performing a transesterification reaction on a dicarboxylic acid, an excess of a diol, and a soft segment component in the presence of a catalyst, followed by polycondensation of the resulting reaction product.

[0036] The silicone-acrylic acid copolymer (B) has a structure comprising at least one silicone (polysiloxane) portion and at least one (meth)acrylic acid polymer portion. Examples of copolymers having this structure include, for instance: the (acrylate / ethylhexyl acrylate / dimethyl methacrylate polysiloxane) copolymer (trade name: KP578) manufactured by Shin-Etsu Silicones Co., Ltd., the wax-type (acrylate / stearyl acrylate / dimethyl methacrylate polysiloxane) copolymer (trade name: KP561P), the (acrylate / docoyl acrylate / dimethyl methacrylate polysiloxane) copolymer (trade name: KP562P), and the CHALINE from Nissin Chemical Industries, Ltd., among others, copolymers with various structures and properties.

[0037] Among these, the silicone-acrylic copolymer (B) is preferably a graft copolymer in which the main backbone is silicone (polysiloxane) and the acrylic polymers on the main backbone are bonded together in a side-chain manner. With this structure, the acrylic polymer portion, which has excellent compatibility with the resin on the matrix side, becomes a branch chain. Due to the enhanced entanglement with the resin, it is difficult to exude and has excellent dispersibility during mixing.

[0038] Acrylic polymers are copolymers / polymers of (meth)acrylates and / or (meth)acrylate hydroxyalkyl esters. When manufacturing the polysiloxane portion, the number of grafting sites in the acrylic polymer can be adjusted by appropriately adding silane monomers with unsaturated groups. In the silicone-acrylic copolymer (B), both the polysiloxane portion and the acrylic polymer portion can be linear or branched. (Methacryl)acrylates and (meth)acrylate hydroxyalkyl esters can be used together, or only either one can be used.

[0039] In addition, the silicone-acrylic acid copolymer (B) can be partially modified and can also be in a core-shell morphology.

[0040] In silicone-acrylic copolymers (B), a higher proportion of the silicone (polysiloxane) portion tends to result in compositions with better lubricity; conversely, a higher proportion of the acrylic polymer tends to result in compositions with better dispersibility. From these perspectives, the polymerization ratio of the silicone to the acrylic polymer (silicone / acrylic polymer) is preferably 5 / 95 to 85 / 15 by mass, more preferably 30 / 70 to 80 / 20, and even more preferably 60 / 40 to 75 / 25.

[0041] When the silicone-acrylic copolymer (B) is solid at room temperature (23°C), it is preferably in granular form. The area-based average particle size is preferably 0.5–120 μm, more preferably 1–100 μm, further preferably 5–80 μm, and even more preferably 20–50 μm. The particle shape can be directly observed using an electron microscope. The area-based average particle size is calculated by measuring the major and minor axes of at least 30 arbitrary particles and normalizing them to an ellipse to calculate the cross-sectional area. When the silicone-acrylic copolymer (B) is in this particle shape, it becomes easier to handle as a granular or powder raw material. Furthermore, when mixed into the composition of the present invention, it disperses rapidly in the composition due to its good dispersibility, resulting in good sliding properties.

[0042] In the molded article obtained by injection molding the thermoplastic polyester elastomer resin composition of the present invention, the average dispersion area of ​​the silicone-acrylic copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming the matrix is ​​0.3 μm. 2 The following explains the means to satisfy this condition.

[0043] Injection molding is a molding method that can produce a large orientation in the shear orientation layer. Typically, the domain (particles) are stretched during injection, and as the process proceeds to the surface, the domain size of the molded article tends to gradually decrease.

[0044] However, when the surface energy difference between the matrix (resin) and the domains (particles) is too large, even if the domains (particles) are stretched during injection, they tend to re-aggregate if the matrix is ​​a thermoplastic polyester elastomer with a slow curing rate (low cooling crystallization temperature Tc2). Therefore, domains with long molecular chains and high surface energy (large energy difference with the resin) tend to revert to their original size, easily failing to undergo micro-dispersion and resulting in poor appearance. Therefore, to improve compatibility with the resin (reduce the energy difference), micro-dispersion is achieved by breaking down the core-shell structure of the particles during injection molding, and particles with low molecular weight are preferred.

[0045] In summary, from the perspective of easy micro-dispersion and improved wear resistance, a smaller molecular weight of the silicone-acrylic copolymer (B) is preferred. If the molecular weight of the silicone-acrylic copolymer (B) is too large, the dispersion of the silicone-acrylic copolymer (B) will be uneven, and large-sized particles will easily remain. The proportion of silicone-acrylic copolymer (B) particles on the surface of the molded article will decrease, and there is a tendency to make it difficult to show the improvement effect on wear resistance. Furthermore, the increase of large-sized particles or the increase of average dispersion area can become a cause of appearance defects such as whitening in the molded article.

[0046] Graft copolymers, such as CHALINE R-175S, CHALINE R-170S, and CHALINE R-170HS, are formed by side-chain bonding of acrylic polymers on the main skeleton, with silicone (polysiloxane) as the main skeleton. These are manufactured by Nissin Chemical Industry.

[0047] Even for graft copolymers with the same composition, the molecular weight is a crucial factor, as explained above. This molecular weight is measured using the weight loss at 250°C as determined by thermogravimetric analysis (TGA).

[0048] In polymeric compounds, as the molecular weight increases, the intermolecular attraction becomes stronger, making thermal deformation less likely and resulting in a tendency for the softening temperature and thermal decomposition temperature to rise. Regarding the silicone-acrylic acid copolymer (B) used in this application, since it exhibits a softening point of around 100°C and a thermal decomposition temperature of around 250°C, the molecular weight deviation can be easily assessed based on the weight loss rate at these temperatures.

[0049] Thermogravimetric analysis (TGA) results for CHALINE R-175S, CHALINE R-170S, and CHALINE R-170HS, with weight loss (%) at each temperature, are shown in Table 1. The TGA determination conditions are as described in the examples below.

[0050] [Table 1]

[0051] 25 0.0 0.0 0.0 50 0.2 0.1 0.1 100 0.9 0.6 0.5 150 1.7 1.3 1.1 200 2.3 1.9 1.6 250 3.5 3.2 3.2 300 7.0 6.9 6.5

[0052] Regarding the weight loss rate at 100℃, R-175S is 0.9%, R-170S is 0.6%, and R-170HS is 0.5%. R-175S has the lowest molecular weight, and based on the order of molecular weight, R-175S can be considered the lowest. <R-170S<R-170HS。

[0053] Furthermore, regarding the weight loss rate at 250°C, R-175S was 3.5%, R-170S was 3.2%, and R-170HS was 3.2%. R-175S has the lowest molecular weight, and based on the order of molecular weight, R-175S can be considered the most suitable. <R-170S≈R-170HS。

[0054] The relationship between the weight reduction rate and molecular weight is integrated in the manufacturer's information (the relationship of molecular weight: R-175S << R-170S < R-170HS) and Japanese Patent Application Publication No. 2019-64281 (CHALINE R-175S average molecular weight 200,000 [paragraph 0090], CHALINE R-170 average molecular weight 400,000 [paragraph 0095]).

[0055] The silicone-acrylic acid copolymer (B) used in this invention preferably exhibits a weight loss rate of 3.3% or more at 250°C, as determined by thermogravimetric analysis (TGA). More preferably, the weight loss rate is 3.4% or more, and even more preferably 3.5% or more. The upper limit of the weight loss rate at 250°C is approximately 4.0%.

[0056] The content of silicone-acrylic copolymer (B) is preferably 1 to 20 parts by weight, more preferably 1.5 to 15 parts by weight, and even more preferably 2 to 12 parts by weight, relative to 100 parts by weight of thermoplastic polyester elastomer (A).

[0057] It can also be used in combination with other slip agents in conjunction with silicone-acrylic copolymer (B). Silicone-acrylic copolymer (B) is not limited to resin components and has good compatibility with any slip agent, including organic and silicone-based ones, thus suppressing problems such as exudation or discoloration caused by other slip agents. However, if too much of the other slip agent is used, the effect of silicone-acrylic copolymer (B) will be reduced. Therefore, when using other slip agents in combination, the amount used is preferably 90 parts by weight or less, more preferably 5 to 70 parts by weight, relative to 100 parts by weight of silicone-acrylic copolymer (B). The absence of other slip agents is also a preferred embodiment.

[0058] In the thermoplastic polyester elastomer resin composition of the present invention, various additives may be added according to the purpose without impairing the effects of the present invention. As additives, the following may be added: known hindered phenolic, sulfur-based, phosphorus-based, and amine-based antioxidants; hindered amine, triazole, benzophenone, benzoate, nickel, and salicylic acid-based light stabilizers; antistatic agents, slip agents (slip agents other than silicone-acrylic copolymer (B)), peroxides, and other molecular modifiers; epoxy compounds, isocyanate compounds, carbodiimide compounds, and other compounds with reactive groups (compatibilizers); metal passivators, organic and inorganic nucleating agents, neutralizing agents, acid stabilizers, antibacterial agents, fluorescent whitening agents, fillers, flame retardants, flame retardant additives, organic and inorganic pigments, etc. The total amount of these additives may be added in the range of 10 parts by weight or less relative to 100 parts by weight of the thermoplastic polyester elastomer (A). In particular, in order to uniformly disperse the silicone-acrylic copolymer (B) in the thermoplastic polyester elastomer (A) forming the matrix, a compatibilizer is preferably included. The compatibilizer is preferably 0.5 to 3 parts by weight relative to 100 parts by weight of the thermoplastic polyester elastomer (A).

[0059] As a method for manufacturing the thermoplastic polyester elastomer resin composition of the present invention, the thermoplastic polyester elastomer (A), silicone-acrylic copolymer (B), and other components are mixed in the prescribed proportions and then melt-blended. Mixing can be performed using a Henschel mixer, a screw mixer, a V-type agitator, etc.; melt blending can be performed using a Banbury internal mixer, a kneading heater, a single-screw or twin-screw melt blending extruder, etc.

[0060] The MFR (g / 10 min) of the thermoplastic polyester elastomer resin composition of the present invention is widely applicable to various molding methods, so there are no particular limitations.

[0061] In the molded article obtained by injection molding the thermoplastic polyester elastomer resin composition of the present invention, the average dispersion area of ​​the silicone-acrylic copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming the matrix satisfies 0.3 μm. 2 The method for determining the average dispersion area of ​​the silicone-acrylic copolymer (B) is as described in the examples below. The average dispersion area of ​​the silicone-acrylic copolymer (B) is preferably 0.25 μm. 2 Below, 0.2 μm is more preferred. 2 The lower limit of the average dispersion area of ​​the silicone-acrylic acid copolymer (B) is 0.005 μm. 2 Around 0.05μm is preferred considering various manufacturing conditions. 2 above.

[0062] The molding method for the thermoplastic polyester elastomer resin composition of the present invention is not specific, and injection molding or blow molding, extrusion molding, foam molding, profile molding, calendering and other various molding methods can be used appropriately. Injection molding is preferred.

[0063] In the molded article composed of the thermoplastic polyester elastomer resin composition described above, the average dispersion area of ​​the silicone-acrylic copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming the matrix is ​​0.3 μm. 2 The following molded body is also one of the inventions of this application.

[0064] The molded articles derived from the thermoplastic polyester elastomer resin composition of the present invention, because they are manufactured according to the above method, have good appearance and good wear resistance. Therefore, the molded articles of the present invention can be suitably used for parts subjected to repeated wear, such as automotive parts. Furthermore, when embossing is present in the molded article, even better wear resistance will be achieved.

[0065] Example

[0066] The present invention will now be specifically described using examples and comparative examples. The present invention is not limited to the following examples, and modifications may be made within the scope of the spirit of the context, and any of them are included within the technical scope of the present invention.

[0067] 1) Average dispersion area and number of coarse particles in silicone-acrylic acid copolymer (B): Microscopic observation

[0068] Based on a 10mm × 10mm molded article with a thickness of 2mm formed by injection molding, a cross-section of the sample was prepared from near the center of the molded article using a cryostat, so that a plane perpendicular to the flow direction could be observed. Images were taken using a Nikon ECLIPSE LV150N industrial microscope at 100x objective. The image was taken at the center of the molded article cross-section where the particle dispersion diameter was stable. The images were analyzed using a Nikon NIS-Elements BR to calculate the average area (average dispersion area) of the observed dispersed particles of the silicone-acrylic copolymer (B). Various coarse particles, as described below, were excluded from the calculated area.

[0069] Furthermore, using a Nikon ECLIPSE LV150N industrial microscope with a 20x objective lens, images were taken at the same location and magnified to 131mm wide and 185mm long. Visual inspection determined that the area of ​​the dispersed particles was equivalent to 100μm. 2 The above refers to the number of coarse-sized particles. The image resolution area is 0.29 mm.2 The number of elements contained within that area is used to represent the total number of elements.

[0070] Using an injection molding machine (Toshiba Machine Manufacturing IS-80G-2AIS), the barrel temperature was set to 250°C in Example 4 and 220°C in the others, and the molded articles for testing were formed at an injection speed of 30%.

[0071] It should be noted that, due to the microdispersion of particles, if the average dispersion area cannot be calculated using the detection methods described above, the average dispersion area can be calculated using a transmission electron microscope (TEM), a more precise analytical method, as explained below.

[0072] Based on a 10mm × 10mm molded article with a thickness of 2mm formed by injection molding, cryosections were prepared from near the center of the article using a cryotome, so that a surface perpendicular to the flow direction could be observed. The sections stained with an electron microscope staining agent (any one of ruthenium tetroxide, osmium tetroxide, or phosphotungstic acid) were observed and photographed using a JEM2100 transmission electron microscope manufactured by NJE at an accelerating voltage of 200kV. The magnification of the photographs was set to 2000–5000. The TEM images were binarized using ImageJ (free software developed by the National Institutes of Health) to calculate the average area (average dispersion area) of the observed dispersed particles of the silicone-acrylic copolymer (B). At this time, various coarse particles were excluded from the calculated area.

[0073] 2) Wear resistance: Thrust wear test

[0074] A SUS cylinder was placed on a 10mm × 10mm molded article with a thickness of 2mm, formed by injection molding under the same conditions as in 1) above. An abrasion test was conducted under a load of 0.37MPa, a sliding speed of 65rpm, and a test time of 10min. The mass before and after the test was compared, with the reduction in mass taken as the abrasion amount. Abrasion amount less than 0.3g was rated as 0, 0.3g to less than 0.35g as △, and more than 0.35g as ×.

[0075] 3) Whitening of appearance: Visual evaluation

[0076] For a 10mm×10mm molded article with a thickness of 2mm formed by injection molding under the same conditions as 1) above, the proportion of whitening area is observed by visual inspection. If it is less than 25%, it is rated as 0; if it is more than 25% but less than 50%, it is rated as △; and if it is more than 50%, it is rated as ×.

[0077] The raw materials used in the examples and comparative examples are shown below.

[0078] [Thermoplastic polyester elastomer (A)]

[0079] A-1: A thermoplastic polyester elastomer (A-1) with a molar ratio of terephthalic acid / 1,4-butanediol / polyoxytetramethylene glycol (PTMG: number average molecular weight 2000) of 100 / 78.8 / 21.2 is manufactured based on the method described in Japanese Patent Application Publication No. 9-59491. The content of the soft segment (PTMG) is 68% by mass, and the specific viscosity is 1.9 dl / g.

[0080] A-2: A thermoplastic polyester elastomer (A-2) with a molar ratio of 2,6-naphthalenedicarboxylic acid / 1,4-butanediol / polyoxytetramethylene glycol (PTMG: number average molecular weight 1000) of 100 / 87.8 / 12.2 is manufactured based on the method described in Japanese Patent Application Publication No. 9-59491. The content of the soft segment (PTMG) is 32% by mass, and the specific viscosity is 1.3 dl / g.

[0081] 0.02 g of thermoplastic polyester elastomer was dissolved in 10 ml of a mixed solvent of phenol / tetrachloroethane (mass ratio 6 / 4), and the specific viscosity was measured at 30 °C using an Ubbelohde viscometer.

[0082] [Silicone-Acrylic Copolymer (B)]

[0083] B-1: CHALINE R-175S, silicone / acrylic polymer = 70 / 30 (mass ratio), average particle size on an area basis of 30 μm, weight loss at 250°C of 3.5%.

[0084] B-2: CHALINE R-170S, silicone / acrylic polymer = 70 / 30 (mass ratio), average particle size on an area basis of 30 μm, weight loss at 250°C of 3.2%.

[0085] B-3: CHALINE R-170HS, silicone / acrylic polymer = 70 / 30 (mass ratio), average particle size on an area basis of 30 μm, weight loss at 250°C of 3.2%.

[0086] B-4: Manufacturing of silicone-modified (meth)acrylic polymer A (an acrylic polymer with polyalkylsiloxane side chains) as described in Japanese Patent Application Publication No. 2016-79228. Silicone / acrylic polymer = 70 / 30 (mass ratio), average particle size based on area 50 μm.

[0087] Thermogravimetric analysis (TGA)

[0088] The weight loss rate of a 5 mg sample at 250 °C was determined using a thermogravimetric analyzer (SII EXSTAR6000, TG6200 / DTA) at a heating rate of 10 °C / min, within the range of 23 to 550 °C. The apparatus was installed in a laboratory at 23 °C and 50% RH.

[0089] [Other additives]

[0090] UV absorber: CHISORB 234 (manufactured by BASF)

[0091] HALS (hindered amine light stabilizer): CHIMASORB 944 (manufactured by BASF)

[0092] Hindered phenolic antioxidant: SONGNOX 245 (manufactured by SONGWON)

[0093] Phosphorus-based antioxidant: HOSTANOX P-EPQ (manufactured by Clariant)

[0094] Compatibilizer: BF-7M, ethylene / glycidyl methacrylate / methyl acrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd.)

[0095] Examples 1-5, Comparative Examples 1-4

[0096] The above thermoplastic polyester elastomer (A) and silicone-acrylic copolymer (B) were dry-blended according to the addition amounts listed in Table 2, and then... A twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.) was used to melt-blend and extrude the resin into filaments at a temperature set of 200–220°C (240–250°C in Example 4). After water cooling, the filaments were granulated using a pelletizer. The resulting granules were then dried under reduced pressure at 100°C for 5 hours to obtain a thermoplastic polyester elastomer resin composition. The evaluation results are shown in Table 2.

[0097]

[0098] The results in Table 2 clearly show that the thermoplastic polyester elastomer resin compositions of Examples 1-5 exhibit excellent appearance and good abrasion resistance. Comparative Examples 1-4, due to the improper dispersion of their silicone-acrylic copolymer (B), showed worse results than the Examples in all properties.

[0099] Industrial availability

[0100] The thermoplastic polyester elastomer resin composition of the present invention is preferred for use as an automotive interior component where wear and tear are repeatedly applied due to its excellent appearance and abrasion resistance.

Claims

1. A thermoplastic polyester elastomer resin composition, characterized in that, It contains a thermoplastic polyester elastomer resin (A) and a silicone-acrylic copolymer (B); the thermoplastic polyester elastomer resin (A) is composed of hard segments of polyester consisting of aromatic dicarboxylic acids and aliphatic and / or alicyclic diols, combined with soft segments selected from at least one of aliphatic polyethers, aliphatic polyesters and aliphatic polycarbonates. The content of the silicone-acrylic copolymer (B) is 2 to 15 parts by weight relative to 100 parts by weight of the thermoplastic polyester elastomer resin (A). The silicone-acrylic acid copolymer (B) is a graft copolymer with silicone as the main skeleton and acrylic polymers on the main skeleton bonded in a side chain manner. The weight loss rate of the silicone-acrylic acid copolymer (B) at 250°C, as measured by thermogravimetric analysis (TGA), was greater than 3.3% and less than 4.0%. In the molded article obtained by injection molding the thermoplastic polyester elastomer resin composition, the average dispersed area of the silicone-acrylic copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming the matrix is 0.2 μm 2 The following.

2. The thermoplastic polyester elastomer resin composition according to claim 1, characterized in that, The weight reduction rate of the silicone-acrylic acid copolymer (B) at 250°C, as measured by thermogravimetric analysis (TGA), was more than 3.5%.

3. A molded body, characterized in that, The molded body is made from a thermoplastic polyester elastomer resin composition containing thermoplastic polyester elastomer resin (A) and silicone-acrylic acid copolymer (B), wherein the thermoplastic polyester elastomer resin (A) is composed of hard segments of polyester consisting of aromatic dicarboxylic acids and aliphatic and / or alicyclic diols, combined with soft segments selected from at least one of aliphatic polyethers, aliphatic polyesters and aliphatic polycarbonates; The content of the silicone-acrylic copolymer (B) is 2 to 15 parts by weight relative to 100 parts by weight of the thermoplastic polyester elastomer resin (A). The silicone-acrylic acid copolymer (B) is a graft copolymer with silicone as the main skeleton and acrylic polymers on the main skeleton bonded in a side chain manner. The weight loss of the silicone-acrylic acid copolymer (B) at 250°C, as measured by thermogravimetric analysis (TGA), was greater than 3.3% and less than 4.0%. In the molded article, the average dispersion area of ​​the silicone-acrylic copolymer (B) dispersed in the thermoplastic polyester elastomer resin (A) forming the matrix is ​​0.2 μm. 2 the following.

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