Polyester resin composition and molded article thereof

Abstract

To provide a polyester resin composition for imparting UV resistance without impairing a color tone of a polyester resin.SOLUTION: A polyester resin composition contains a polyester resin (A) and a dye (B), wherein the polyester resin (A) has a dicarboxylic acid constitutional unit and a diol constitutional unit, the dicarboxylic acid constitutional unit is a terephthalic acid unit and / or a 2,6-naphthalenedicarboxylic acid unit, 5 to 90 mol% of the diol constitutional unit is a unit represented by the following general formula (1) or (2), and 5 to 90 mol% of the diol constitutional unit is a unit derived from alicyclic diol, and the dye (B) is a combination of two or more kinds of dyes having structures including at least two secondary amino groups and at least one benzene ring.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyester resin composition and a molded article such as a baby bottle made using the polyester resin composition. [Background technology]

[0002] Aromatic saturated polyester resins, particularly polyethylene terephthalate (PET), offer a well-balanced combination of mechanical properties, solvent resistance, aroma retention, weather resistance, and recyclability. They are widely used, primarily for applications such as bottles and films. However, PET has drawbacks in terms of crystallinity and heat resistance. Because PET is highly crystalline, attempting to produce thick molded products or sheets results in whitening due to crystallization and loss of transparency. Furthermore, PET's glass transition temperature is around 80°C, making it unsuitable for applications requiring high heat resistance and transparency, such as products used inside automobiles, packaging for imports and exports, food packaging for retort or microwave heating, and baby bottles and tableware for heat sterilization.

[0003] For this reason, low-crystalline polyester resins such as modified PET partially copolymerized with 1,4-cyclohexanedimethanol and modified PET partially modified with isophthalic acid have traditionally been used for applications requiring transparency. However, although modified PET partially copolymerized with 1,4-cyclohexanedimethanol and modified PET partially modified with isophthalic acid each offer improved transparency compared to PET, their glass transition temperatures are around 80°C, making them poor in heat resistance.

[0004] In addition, in fields requiring heat resistance, polyester resins with high glass transition temperatures, such as polyethylene 2,6-naphthalate (hereinafter sometimes referred to as "PEN") and poly(1,4-cyclohexanedimethylene terephthalate), have been used. However, although PEN and poly(1,4-cyclohexanedimethylene terephthalate) have improved heat resistance, they also have high crystallinity and poor transparency.

[0005] In addition, polyester resins containing diols having a cyclic acetal skeleton have been proposed as polyester resins that have high transparency while improving the heat resistance of PET and PEN (Patent Documents 1 and 2). Such polyester resins can be used in applications that require transparency and heat resistance.

[0006] However, in the field of baby bottles and other products, where boiling sterilization was previously used, home UV sterilization devices have become widespread in recent years, and UV sterilization has become the standard sterilization method. In addition, in response to growing social needs such as ESG and SDGs, the packaging of baby bottles and other products is becoming simpler (from paper box packaging to simple shrink film only). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-105873 [Patent Document 2] International Publication No. 2020 / 218324 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, there is a need to impart UV resistance to polyester resins to prevent deterioration such as loss of strength and color change caused by UV irradiation from UV sterilization equipment, etc., or exposure to fluorescent lights and sunlight when displayed in stores. Furthermore, when imparting UV resistance, it is also necessary to not impair (or improve) the color tone of thermoplastic polyester resins. [Means for solving the problem]

[0009] As a result of extensive research, the present inventors have discovered that by combining a polyester resin having a predetermined composition with two or more dyes having specific structures, it is possible to impart UV resistance to the polyester resin without deteriorating its color tone, and have thus completed the present invention.

[0010] That is, the present invention includes the following aspects. [1] A polyester resin composition comprising a polyester resin (A) and a dye (B), The polyester resin (A) has a dicarboxylic acid structural unit and a diol structural unit, the dicarboxylic acid constituent unit is a terephthalic acid unit and / or a 2,6-naphthalenedicarboxylic acid unit, 5 to 90 mol % of the diol constituent units are units derived from a diol having a cyclic acetal skeleton represented by the following general formula (1) or general formula (2), and 5 to 90 mol % of the diol constituent units are units derived from an alicyclic diol, The dye (B) is a combination of two or more dyes having a structure containing at least two secondary amino groups and at least one benzene ring. A polyester resin composition comprising: [ka] (In formula (1), R 1 and R 2 each independently represents an aliphatic group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms. [ka] (In formula (2), R 1 is the same as above, and R 3 represents an aliphatic group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms. [2] The polyester resin composition according to [1] above, wherein the dye (B) is a dye of two or more colors selected from the group consisting of CI (Color Index) Solvent Blue RR, Solvent Blue 97, Solvent Blue 104, Solvent Violet 36, and Reactive Red 2. [3] The polyester resin composition according to the above item [1], wherein the dye (B) is two or more dyes selected from the group consisting of compounds represented by the following formulas (3) to (6): [ka] [4] The polyester resin composition according to any one of the above [1] to [3], which contains the dye (B) in an amount of 3.0 ppm or more and 10 ppm or less. [5] The polyester resin composition according to any one of the above [1] to [4], wherein the diol having a cyclic acetal skeleton is 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, and the alicyclic diol is 1,4-cyclohexanedimethanol. [6] The polyester resin composition according to any one of the above [1] to [5], wherein the dicarboxylic acid constitutional unit is a 2,6-naphthalenedicarboxylic acid unit. [7] The polyester resin composition according to any one of the above [1] to [6], wherein the content of polycarbodiimide contained in the polyester resin composition is less than 0.1% by mass. [8] A molded article using the polyester resin composition according to any one of the above [1] to [7]. [9] A container using the polyester resin composition according to any one of the above [1] to [8].

[10] A baby bottle using the polyester resin composition according to any one of the above [1] to [9]. [Effects of the Invention]

[0011] The polyester resin composition of the present invention is endowed with UV resistance and does not impair color tone. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0013] <Polyester resin composition> The polyester resin composition of the present embodiment contains a polyester resin (A) and a dye (B).

[0014] [Polyester resin (A)] The polyester resin (A) has dicarboxylic acid structural units and diol structural units.

[0015] (Diol building block) 5 to 90 mol % of the diol structural units in the polyester resin (A) are units derived from a diol having a cyclic acetal skeleton represented by the following general formula (1) or general formula (2), and 5 to 90 mol % of the diol structural units are units derived from an alicyclic diol. [ka] [ka]

[0016] In the above formulas (1) and (2), R 1 and R 2are each independently an aliphatic group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms, and are preferably selected from the group consisting of a methylene group, an ethylene group, a propylene group, a butylene group, and structural isomers thereof, such as an isopropylene group and an isobutylene group. R 3 is an aliphatic group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms, and is preferably selected from the group consisting of a methyl group, an ethyl group, a propyl group, a butyl group, and structural isomers thereof, such as an isopropyl group and an isobutyl group.

[0017] As the diol having a cyclic acetal skeleton represented by the above formula (1), 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (also called spiro glycol) is particularly preferred.

[0018] As the diol having a cyclic acetal skeleton represented by the above formula (2), 5-methylol-5-ethyl-2-(1,1-dimethyl-2-hydroxyethyl)-1,3-dioxane is particularly preferred.

[0019] The units derived from alicyclic diols in the diol constituent units of the polyester resin (A) are not particularly limited, and examples thereof include units derived from diols such as 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,2-decahydronaphthalenedimethanol, 1,3-decahydronaphthalenedimethanol, 1,4-decahydronaphthalenedimethanol, 1,5-decahydronaphthalenedimethanol, 1,6-decahydronaphthalenedimethanol, 2,7-decahydronaphthalenedimethanol, tetralindimethanol, norbornene dimethanol, tricyclodecane dimethanol, and pentacyclododecane dimethanol. Of these, units derived from 1,4-cyclohexanedimethanol, norbornene dimethanol, tricyclodecane dimethanol, and 2,6-decahydronaphthalenedimethanol are preferred, and units derived from 1,4-cyclohexanedimethanol are particularly preferred.

[0020] In this embodiment, it is preferable that the diol having a cyclic acetal skeleton is 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (spiroglycol) and the alicyclic diol is 1,4-cyclohexanedimethanol.

[0021] The diol structural units of this embodiment may contain other diol structural units in addition to the diol units having a cyclic acetal skeleton and the alicyclic diol units. The content of the other diol structural units may be 0 to 90 mol% relative to 100 mol% of the diol structural units. It is preferably 0 to 70 mol%, more preferably 0 to 50 mol%, and particularly preferably 0 mol% or more and less than 50 mol%. Examples of other diol constituent units include units derived from diols such as aliphatic diols such as ethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, propylene glycol, and neopentyl glycol; polyether compounds such as polyethylene glycol, polypropylene glycol, and polybutylene glycol; bisphenols such as 4,4'-(1-methylethylidene)bisphenol, methylenebisphenol (bisphenol F), 4,4'-cyclohexylidenebisphenol (bisphenol Z), and 4,4'-sulfonylbisphenol (bisphenol S); alkylene oxide adducts of the above bisphenols; aromatic dihydroxy compounds such as hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, and 4,4'-dihydroxydiphenylbenzophenone; and alkylene oxide adducts of the above aromatic dihydroxy compounds. In consideration of the mechanical strength, heat resistance and availability of the polyester resin, when other diol structural units are contained, it is preferable that they are units derived from ethylene glycol.

[0022] (Dicarboxylic acid structural unit) The dicarboxylic acid constituent unit in the polyester resin (A) contains a terephthalic acid unit and / or a 2,6-naphthalenedicarboxylic acid unit. The terephthalic acid unit means a unit derived from terephthalic acid. The 2,6-naphthalenedicarboxylic acid unit means a unit derived from 2,6-naphthalenedicarboxylic acid. Examples of the terephthalic acid unit include units derived from terephthalic acid and dimethyl terephthalate. Preferably, the dicarboxylic acid constituent unit is a 2,6-naphthalenedicarboxylic acid unit.

[0023] Furthermore, the dicarboxylic acid constituent unit may contain other dicarboxylic acid constituent units as long as the object of this embodiment is not impaired. Examples of other dicarboxylic acid constituent units include, but are not limited to, units derived from aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, decalindicarboxylic acid, norbornanedicarboxylic acid, tricyclodecanedicarboxylic acid, pentacyclododecanedicarboxylic acid, 3,9-bis(1,1-dimethyl-2-carboxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, and 5-carboxy-5-ethyl-2-(1,1-dimethyl-2-carboxyethyl)-1,3-dioxane; and units derived from aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 2-methylterephthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and tetralindicarboxylic acid.

[0024] In this embodiment, from the viewpoint of sufficiently improving the balance of physical properties such as transparency, heat resistance, impact resistance, and mechanical strength of the polyester resin (A), the polyester resin (A) preferably contains 80 to 100 mol % of terephthalic acid units and / or 2,6-naphthalenedicarboxylic acid units, more preferably 90 to 100 mol %, and particularly preferably 100 mol %, per 100 mol % of dicarboxylic acid constituent units.

[0025] The polyester resin (A) contains 5 to 90 mol % of the units derived from the diol having a cyclic acetal skeleton, relative to 100 mol % of all diol constituent units, resulting in reduced crystallinity and a high glass transition temperature, resulting in high transparency and heat resistance. The polyester resin (A) has a better balance of transparency and heat resistance than, for example, polyester resins in which 100 mol % of the diol constituent units are derived from ethylene glycol and 1,4-cyclohexanedimethanol, or other polyester resins such as PET, polybutylene terephthalate, and polylactic acid. From the same perspective, the polyester resin (A) preferably contains 15 to 80 mol %, and more preferably 20 to 70 mol %, of the units derived from the diol having a cyclic acetal skeleton.

[0026] The polyester resin (A) contains 5 to 90 mol % of the units derived from the above alicyclic diol, relative to 100 mol % of all diol constituent units. In this embodiment, from the viewpoint of further improving the impact resistance of the polyester resin (A), the polyester resin (A) contains preferably 10 to 90 mol %, more preferably 15 to 90 mol %, of the units derived from the alicyclic diol.

[0027] In the present embodiment, from the viewpoint of impact resistance, examples include polyester resins in which 15 to 50 mol % of the diol constituent units in the polyester resin (A) are units derived from a diol having a cyclic acetal skeleton, and 15 to 85 mol % are units derived from an alicyclic diol.

[0028] In this embodiment, particularly considering the balance of transparency, heat resistance, impact resistance, mechanical strength, and the like, it is preferred that 100 mol % of the dicarboxylic acid constituent units in the polyester resin (A) are terephthalic acid units and / or 2,6-naphthalenedicarboxylic acid, and that 5 to 90 mol % of the diol constituent units are units derived from 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 5 to 90 mol % of units derived from 1,4-cyclohexanedimethanol, and 0 to 90 mol % of units derived from ethylene glycol. From a similar viewpoint, it is particularly preferred that 100 mol % of the dicarboxylic acid constituent units in the polyester resin (A) are terephthalic acid units and / or 2,6-naphthalenedicarboxylic acid units, and that 15 to 50 mol % of the diol constituent units are units derived from 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 15 to 85 mol % are units derived from 1,4-cyclohexanedimethanol, and 0 to 70 mol % are units derived from ethylene glycol.

[0029] (other building blocks) The polyester resin (A) may contain, within the scope of the present embodiment, monoalcohol units such as butyl alcohol, hexyl alcohol, and octyl alcohol; trihydric or higher polyhydric alcohol units such as trimethylolpropane, glycerin, 1,3,5-pentanetriol, and pentaerythritol; monocarboxylic acid units such as benzoic acid, propionic acid, and butyric acid; polycarboxylic acid units such as trimellitic acid, trimethyl trimellitate, trimellitic anhydride, and pyromellitic acid; and oxyacid units such as glycolic acid, lactic acid, hydroxybutyric acid, 2-hydroxyisobutyric acid, and hydroxybenzoic acid.

[0030] The method for producing the polyester resin of this embodiment is not particularly limited, and any conventionally known method can be used. Examples include melt polymerization methods such as transesterification and direct esterification, and solution polymerization. Conventionally known transesterification catalysts, esterification catalysts, various stabilizers such as etherification inhibitors, heat stabilizers, and light stabilizers, and polymerization regulators can also be used.

[0031] [Dye (B)] The dye (B) in this embodiment is a combination of two or more dyes each having a structure containing at least two secondary amino groups and at least one benzene ring. There are no particular limitations on the dye as long as it has a structure containing at least two secondary amino groups and at least one benzene ring, and various known dyes can be used.

[0032] Preferably, dye (B) is two or more dyes selected from the group consisting of compounds represented by the following formulas (3) to (6), more preferably a combination of (3) or (6) with (4) or (5), particularly preferably a combination of a compound of formula (3) with a compound of formula (4), or a combination of a compound of formula (5) with a compound of formula (6), and most preferably a combination of a compound of formula (3) with a compound of formula (4). The compound of formula (3) corresponds to Color Index Solvent Blue RR and Color Index Solvent Blue 97. The compound of formula (4) corresponds to Color Index Solvent Violet 36. The compound of formula (5) corresponds to Reactive Red 2. The compound of formula (6) corresponds to Solvent Blue 104. [ka]

[0033] A preferred blending ratio (unit: mass) is (3) or (6):(4) or (5)=99-50:1-50, particularly 70-50:30-50, and particularly preferred is (3):(4)=99-50:1-50, particularly 70-50:30-50 in the case of a combination of a compound of formula (3) and a compound of formula (4). In the case of a combination of a compound of formula (6) and a compound of formula (5), (6):(5)=99-50:1-50, particularly 70-50:30-50.

[0034] Preferably, dye (B) is two or more dyes selected from the group consisting of CI (Color Index) Solvent Blue RR, Solvent Blue 97, Solvent Blue 104, Solvent Violet 36, and Reactive Red 2, and more preferably a combination of at least one dye selected from the group consisting of Solvent Blue RR, Solvent Blue 97, and Solvent Blue 104 and at least one dye selected from the group consisting of Solvent Violet 36 and Reactive Red 2. Dye (B) is particularly preferably a combination of Solvent Blue RR and Solvent Violet 36, a combination of Solvent Blue 97 and Solvent Violet 36, or a combination of Reactive Red 2 and Solvent Blue 104. Most preferably, dye (B) is a combination of Solvent Blue RR and Solvent Violet 36, or a combination of Solvent Blue 97 and Solvent Violet 36. The blending ratio (unit: mass) of at least one selected from the group consisting of Solvent Blue RR, Solvent Blue 97, and Solvent Blue 104 to at least one selected from the group consisting of Solvent Violet 36 and Reactive Red 2 is preferably 99-50:1-50, particularly 70-50:30-50. In the case of a combination of Solvent Blue RR and Solvent Violet 36, the ratio of Solvent Blue RR to Solvent Violet 36 is preferably 99-50:1-50, particularly 70-50:30-50. In the case of a combination of Solvent Blue 97 and Solvent Violet 36, the ratio of Solvent Blue 97 to Solvent Violet 36 is preferably 99-50:1-50, particularly 70-50:30-50. In the case of a combination of Reactive Red 2 and Solvent Blue 104, the ratio of Solvent Blue 104:Reactive Red 2 is preferably 99 to 50:1 to 50, particularly 70 to 50:30 to 50.

[0035] The content of dye (B) may be determined appropriately depending on the type of polyester resin, the type of dye, and the like. The lower limit of the content is preferably 0.5 ppm or more, more preferably 2.0 ppm or more, particularly preferably 3.0 ppm or more, and most preferably 3.2 ppm or more. The upper limit is preferably 10 ppm or less, more preferably 7.5 ppm or less, and particularly preferably 7.0 ppm or less. That is, the content of dye (B) is suitably in the range selected from the group consisting of 0.5 to 10 ppm, 0.5 to 7.5 ppm, 0.5 to 7.0 ppm, 2.0 to 10 ppm, 2.0 to 7.5 ppm, 2.0 to 7.0 ppm, 3.0 to 10 ppm, 3.0 to 7.5 ppm, 3.0 to 7.0 ppm, 3.2 to 10 ppm, 3.2 to 7.5 ppm, and 3.2 to 7.0 ppm.

[0036] Although the method of addition is not particularly limited, melt-kneading using an extruder is preferred. In this case, a high concentration of dye (B) may be melt-kneaded in the polyester resin (A) to prepare a master batch, which may then be diluted to a predetermined concentration before molding.

[0037] As described above, the polyester resin (A) exhibits excellent performance in terms of heat resistance, transparency, and impact resistance. Furthermore, the polyester resin composition of this embodiment contains two or more dyes having the specific structure described above as the dye (B). By using multiple dyes, yellowing and a decrease in mechanical strength upon UV irradiation can be effectively suppressed without impairing the color tone. The addition of a UV absorber is a commonly known method for improving the UV resistance of resins. However, according to the inventors' research, as the amount of UV absorber added increases, the absorbance in the UV region increases, which is expected to suppress photodegradation of the resin. However, this also tends to reduce mechanical strength, and the surface roughness caused by bleed-out of the UV absorber may become the starting point for fracture. Furthermore, UV absorbers mainly absorb light in the UV region (short wavelength region of visible light), which can cause the resin to yellow, making them unsuitable for transparent applications. Dye (B) is believed to improve UV resistance without compromising color tone, eliminating the concerns associated with the use of such UV absorbers.

[0038] [Optional ingredients] In addition to the polyester resin (A) and the dye (B), any optional components may be added to the polyester resin composition of the present embodiment.

[0039] Optional components include, but are not limited to, various additives and molding aids such as antioxidants, light stabilizers, plasticizers, extenders, matting agents, drying regulators, antistatic agents, antisettling agents, surfactants, flow improvers, drying oils, waxes, fillers, reinforcing agents, surface smoothing agents, leveling agents, and curing reaction accelerators. Optional components may also include resins and oligomers such as polyolefin resins, polyester resins other than polyester resin (A), polyamide resins, polycarbonate resins, acrylonitrile resins, vinyl chloride resins, vinyl acetate resins, polyacrylic resins, polymethacrylic resins, polystyrene, ABS resins, polyimide resins, and AS resins.

[0040] The content of the optional components is not particularly limited, but from the viewpoints of improving impact resistance while ensuring good heat resistance and transparency and effectively suppressing embrittlement after heat treatment, the content is preferably 2.9% by mass or less, more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less, relative to 100% by mass of the polyester resin composition.

[0041] However, when polycarbodiimide is contained as an optional component, the content thereof is preferably less than 0.1% by mass, and most preferably, the composition is substantially free of polycarbodiimide.

[0042] When a pigment is included as an optional component, its content is preferably less than 2.0 ppm, more preferably less than 1.0 ppm. Most preferably, the resin is substantially free of pigment. The pigment content refers to the amount of pigment contained in the resin. In the case of a resin molded product, the amount of pigment applied to the surface of the molded product is not used in calculating the pigment content.

[0043] [Physical Properties] The polyester resin composition of this embodiment is injection molded into a 2.0 mm thick plate, and after 48 hours of humidity conditioning, the L value measured in an atmosphere of 23°C and 50% relative humidity is preferably 92.0 or more, particularly 93.5 or more. Furthermore, the a value measured in the same manner is preferably -0.1 or more and less than 0.6, particularly 0.1 or more and less than 0.4. Furthermore, the b value measured in the same manner is preferably -2.6 or more and less than 1.1, particularly -1.5 or more and less than 0.0.

[0044] The polyester resin composition of the present embodiment can be injection molded into a flat plate having a thickness of 2.0 mm, and can be applied to, for example, a belt conveyor-type UV irradiator (light source: high-pressure mercury lamp, irradiation peak intensity (lamp distance: 180 mm): 319 mW / cm 2 , Accumulated light intensity per irradiation: 2,265mJ / cm 2When the film is irradiated with UV light a total of 48 times using a UV irradiator such as a UV irradiator 1000W, the change in the b value Δ (b value after UV irradiation - b value before UV irradiation) measured before and after the UV irradiation test using the same measurement method as above is preferably 1.5 or less, particularly 1.1 or less.

[0045] The polyester resin composition of the present embodiment can be injection molded into dumbbell pieces conforming to ISO 527, and can be applied to, for example, a belt conveyor-type UV irradiator (light source: high-pressure mercury lamp, irradiation peak intensity (lamp distance 180 mm): 319 mW / cm 2 , Accumulated light intensity per irradiation: 2,265mJ / cm 2 When the film is irradiated with UV light a total of 48 times using a UV irradiator such as a UV irradiation machine, the change in tensile elongation at break Δ before and after UV irradiation (tensile elongation at break after UV irradiation - tensile elongation before UV irradiation) is preferably -13 or more, particularly -5 or more.

[0046] <Uses of polyester resin composition> Various molded articles can be produced using the polyester resin composition of this embodiment. For example, the composition can be used for injection-molded articles, extrusion-molded articles such as sheets, films, and pipes, bottles, foams, pressure-sensitive adhesives, adhesives, and paints. More specifically, the injection-molded articles can be insert-molded or two-color-molded. The sheets can be single-layered or multi-layered, and the films can be single-layered or multi-layered. They can be unstretched, stretched in one direction, or stretched in two directions, and can be laminated to a steel plate or the like. The films can be inflation-molded. The bottles can be direct-blown bottles, injection-blown bottles, or injection-molded bottles. The foams can be bead foams or extrusion foams. The composition is particularly suitable for applications where exposure to ultraviolet light is expected, such as products used inside automobiles, packaging materials for import and export, food packaging materials, and containers such as baby bottles and tableware. That is, the polyester-based injection-molded article, polyester-based extrusion-molded article, polyester-based foam, polyester-based container, polyester-based bottle, polyester-based tableware, and polyester-based baby bottle of this embodiment can each be said to contain the polyester resin composition of this embodiment. These are not particularly limited as long as they contain the polyester resin composition of this embodiment, and can be in various known forms suited to their respective uses. [Example]

[0047] The present embodiment will be described in more detail below with reference to examples, but the scope of the present embodiment is not limited to these examples.

[0048] [Evaluation method] (1) Lab values The flat plates obtained in the examples and comparative examples described below were conditioned for 48 hours, and then the Lab values ​​of the Hunter color system were measured in an atmosphere of 23°C and 50% relative humidity. The measuring device used was a haze value measuring device (model: COH-300A) manufactured by Nippon Denshoku Industries Co., Ltd. The measuring device used was an apparatus conforming to JIS-K-7105 and ASTM D1003. Points were assigned according to the following criteria. [Table 1]

[0049] (2) Yellowing resistance The flat plates obtained in the examples and comparative examples described below were irradiated with a belt conveyor-type UV irradiator (light source: high-pressure mercury lamp, irradiation peak intensity (lamp distance 180 mm): 319 mW / cm 2 , Accumulated light intensity per irradiation: 2,265mJ / cm 2 ) UV irradiation was carried out a total of 48 times. Using the same measurement method as in (1), the b value of the plate was measured before and after UV irradiation, and the change Δ (b value after UV irradiation - b value before UV irradiation) was calculated. Points were assigned according to the following criteria. [Table 2]

[0050] (3) Decreased mechanical strength The dumbbell pieces obtained in the examples and comparative examples described below were subjected to a belt conveyor-type UV irradiation device (light source: high-pressure mercury lamp, irradiation peak intensity (lamp distance 180 mm): 319 mW / cm 2 , Accumulated light intensity per irradiation: 2,265mJ / cm 2 ) UV irradiation was carried out a total of 48 times. The tensile elongation at break was measured before and after UV irradiation using a Strograph APIII from Toyo Seiki Seisakusho Co., Ltd., and the change in Δ (tensile elongation at break after UV irradiation - tensile elongation before UV irradiation) was calculated. Points were assigned according to the following criteria. [Table 3]

[0051] [Synthesis of SH] For a 30-liter polyester manufacturing plant equipped with a packed column type rectification column, a partial condenser, a total condenser, a cold trap, an agitator, a heater, and a nitrogen inlet pipe, the following raw material monomers were used: 38.3 mol of dimethyl 2,6-naphthalenedicarboxylate, ethylene glycol 17.9 moles, 22.9 moles of 1,4-cyclohexanedimethanol, and Spiroglycol 17.9 mol The mixture was charged with dimethyl 2,6-naphthalenedicarboxylate, to which 0.005 mol % of tetra-n-butoxytitanium and 0.02 mol % of potassium acetate were added, and the mixture was heated to 225°C under a nitrogen atmosphere to carry out a transesterification reaction. After the reaction conversion of the dicarboxylic acid component reached 90% or more, 0.025 mol % of germanium dioxide and 0.05 mol % of triethyl phosphate were added to the dicarboxylic acid component, and the temperature was gradually increased and the pressure was gradually reduced, ultimately carrying out polycondensation at 280°C and 0.1 kPa or less. The reaction was terminated when an appropriate melt viscosity was reached, yielding a polyester resin (SH resin).

[0052] [Synthesis of SC] A 30-liter polyester manufacturing plant equipped with a packed column type rectification column, partial condenser, total condenser, cold trap, agitator, heater, and nitrogen inlet pipe was used as the raw material monomer. dimethyl terephthalate 51.2 moles, Trimethyl trimellitate 0.15 mol, ethylene glycol 44.1 moles, 48.4 moles of 1,4-cyclohexanedimethanol, and Spiroglycol 5.4 mol The mixture was charged with 0.010 mol% tetra-n-butoxytitanium and 0.02 mol% potassium acetate were added to the dicarboxylic acid component, and the temperature was raised to 225°C under a nitrogen atmosphere to carry out an ester exchange reaction. After the reaction conversion of the dicarboxylic acid component reached 90% or more, 0.10 mol% germanium dioxide and 0.05 mol% triethyl phosphate were added to the dicarboxylic acid component, and the temperature was gradually raised and the pressure was gradually reduced, finally carrying out polycondensation at 285°C and 0.1 kPa or less. The reaction was terminated when an appropriate melt viscosity was reached, and a polyester resin (SC resin) was obtained.

[0053] [Example 1] (Preparation of mixed pellets) Using a twin-screw kneading extruder (manufactured by Toshiba Machine Co., Ltd., model: TEM26SX, screw diameter: 26 mmφ, L / D: 48), polyester resin and various additives were dry blended according to the composition shown in Table 4 and charged into the hopper. Strands were extruded under conditions of a cylinder temperature of 180 to 260°C, a die temperature of 260°C, a screw rotation speed of 75 rpm, and a discharge rate of 15 kg / h, and were water-cooled and pelletized to obtain polyester resin composition pellets.

[0054] (Injection molding of kneaded pellets) The resulting kneaded pellets were then injection molded to obtain 2.0 mm thick plates and dumbbell pieces conforming to ISO 527. A J85AD injection molding machine manufactured by The Japan Steel Works, Ltd. was used for injection molding, with a cylinder temperature of 245 to 280°C and a mold temperature of 15 to 50°C. Lab value measurements, yellowing resistance tests, and mechanical strength degradation resistance tests were conducted using the molded plates and dumbbell pieces. The results are shown in Table 4.

[0055] [Examples 2 to 6] Flat plates and dumbbell pieces were produced and evaluated in the same manner as in Example 1, except that the compositions were as shown in Table 4. The results are shown in Table 4.

[0056] [Comparative Examples 1 to 13] Flat plates and dumbbell pieces were produced and evaluated in the same manner as in Example 1, except that the compositions were as shown in Table 4. The results are shown in Table 4.

[0057] The compositions and properties of the test pieces (flat plates and dumbbell pieces) obtained in Examples 1 to 6 and Comparative Examples 1 to 13 are shown below. [Table 4]

[0058] The structures of the additives in Table 4 above are shown below. [ka]

Claims

1. A polyester resin composition comprising a polyester resin (A) and a dye (B), The polyester resin (A) has a dicarboxylic acid structural unit and a diol structural unit, the dicarboxylic acid constituent unit is a terephthalic acid unit and / or a 2,6-naphthalenedicarboxylic acid unit, 5 to 90 mol % of the diol structural units are units derived from a diol having a cyclic acetal skeleton represented by the following general formula (1) or general formula (2), and 5 to 90 mol % of the diol structural units are units derived from an alicyclic diol, The dye (B) is a combination of Solvent Blue RR and Solvent Violet 36, a combination of Solvent Blue 97 and Solvent Violet 36, or a combination of Reactive Red 2 and Solvent Blue 104, The blending ratio (unit: mass) of Solvent Blue RR and Solvent Violet 36 is Solvent Blue RR: Solvent Violet 36 = 70-50:30-50, The compounding ratio (unit: mass) of Solvent Blue 97 to Solvent Violet 36 is Solvent Blue 97:Solvent Violet 36=70-50:30-50, The blending ratio (unit: mass) of Reactive Red 2 and Solvent Blue 104 is Solvent Blue 104:Reactive Red 2=70-50:30-50, The dye (B) is contained in an amount of 0.5 ppm or more and 10 ppm or less. A polyester resin composition comprising: 【Chemistry 1】 (In formula (1), R １ and R ２ each independently represents an aliphatic group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms. 【Chemistry 2】 (In formula (2), R １ is the same as above, and R ３ represents an aliphatic group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms.

2. A polyester resin composition comprising a polyester resin (A) and a dye (B), The polyester resin (A) has a dicarboxylic acid structural unit and a diol structural unit, the dicarboxylic acid constituent unit is a terephthalic acid unit and / or a 2,6-naphthalenedicarboxylic acid unit, 5 to 90 mol % of the diol structural units are units derived from a diol having a cyclic acetal skeleton represented by the following general formula (1) or general formula (2), and 5 to 90 mol % of the diol structural units are units derived from an alicyclic diol, The dye (B) is a combination of a compound represented by the following formula (3) and a compound represented by the following formula (4), or a combination of a compound represented by the following formula (5) and a compound represented by the following formula (6), The compounding ratio (unit: mass) of the compound of the following formula (3) to the compound of the following formula (4) is the compound of the following formula (3):the compound of the following formula (4)=70 to 50:30 to 50, The compounding ratio (unit: mass) of the compound of the following formula (5) to the compound of the following formula (6) is the compound of the following formula (6):the compound of the following formula (5)=70 to 50:30 to 50, The dye (B) is contained in an amount of 0.5 ppm or more and 10 ppm or less. A polyester resin composition comprising: 【Transformation 3】 (In formula (1), R 1 and R 2 each independently represent an aliphatic group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms.) 【Chemistry 4】 (In formula (2), R 1 is the same as defined above, and R 3 represents an aliphatic group having 1 to 10 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms.) 【Transformation 5】

3. 3. The polyester resin composition according to claim 1, wherein the diol having a cyclic acetal skeleton is 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, and the alicyclic diol is 1,4-cyclohexanedimethanol.

4. 3. The polyester resin composition according to claim 1, wherein the dicarboxylic acid structural unit is a 2,6-naphthalenedicarboxylic acid unit.

5. The polyester resin composition according to claim 1 or 2, wherein the content of the polycarbodiimide contained in the polyester resin composition is less than 0.1% by mass.

6. A molded article using the polyester resin composition according to claim 1 or 2.

7. A container using the polyester resin composition according to claim 1 or 2.

8. A baby bottle using the polyester resin composition according to claim 1 or 2.

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