Polyester resin composition and molded article thereof

Abstract

The present invention can provide a polyester resin composition comprising 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; 5-90 mol% of the diol constitutional unit is a unit represented by general formula (1) or (2); 5-90 mol% of the diol constitutional unit is a unit derived from an alicyclic diol; and the dye (B) is obtained by combining at least two dyes having a structure that contains at least two secondary amino groups and at least one benzene ring.

Description

Polyester resin composition and molded article thereof

[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.

[0002] Aromatic saturated polyester resins, particularly polyethylene terephthalate (hereinafter sometimes referred to as "PET"), are resins that offer a good balance of mechanical properties, solvent resistance, aroma retention, weather resistance, recyclability, and the like, and are widely used, primarily for applications such as bottles and films. However, PET has drawbacks in terms of crystallinity and heat resistance. Specifically, with regard to crystallinity, PET has high crystallinity, so when attempting to produce thick molded articles or sheets, it whitens due to crystallization and loses transparency. With regard to heat resistance, PET has a glass transition temperature of approximately 80°C, making it unsuitable for applications requiring high heat resistance and transparency, such as products used inside automobiles, packaging materials for import and export, food packaging materials that are retorted or microwave-heated, and baby bottles and tableware that are heat-sterilized.

[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 conventionally 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 have improved transparency compared to PET, their glass transition temperatures are around 80°C and their heat resistance is poor.

[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] Furthermore, 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 traditionally used, the use of home UV sterilizers has become widespread in recent years, and UV sterilization has become the standard sterilization method. Furthermore, 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).

[0007] JP 2017-105873 A International Publication No. 2020 / 218324

[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 maintain (or improve) the color tone of thermoplastic polyester resins.

[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 encompasses the following aspects: [1] A polyester resin composition comprising a polyester resin (A) and a dye (B), wherein the polyester resin (A) has dicarboxylic acid structural units and diol structural units, the dicarboxylic acid structural units are terephthalic acid units and / or 2,6-naphthalenedicarboxylic acid units, 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, and 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. (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. (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 [1] above, wherein the dye (B) is a dye of two or more colors selected from the group consisting of compounds represented by the following formulas (3) to (6): [4] The polyester resin composition according to any one of [1] to [3] above, containing the dye (B) in an amount of 3.0 ppm to 10 ppm. [5] The polyester resin composition according to any one of [1] to [4] above, 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 [1] to [5] above, wherein the dicarboxylic acid structural unit is a 2,6-naphthalenedicarboxylic acid unit. [7] The polyester resin composition according to any one of [1] to [6] above, wherein the content of polycarbodiimide contained in the polyester resin composition is less than 0.1 mass %. [8] A molded article using the polyester resin composition according to any one of [1] to [7] above. [9] A container using the polyester resin composition according to any one of [1] to [8] above.

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

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

[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 a dicarboxylic acid structural unit and a diol structural unit.

[0015] (Diol Structural Units) 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.

[0016] In the above formulas (1) and (2), R １ and R ２ are 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. 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 unit derived from an alicyclic diol in the diol constituent units of the polyester resin (A) is 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. A unit derived from 1,4-cyclohexanedimethanol, a unit derived from norbornene dimethanol, a unit derived from tricyclodecane dimethanol, or a unit derived from 2,6-decahydronaphthalenedimethanol is preferred, and a unit derived from 1,4-cyclohexanedimethanol is 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. The content is preferably 0 to 70 mol %, more preferably 0 to 50 mol %, and particularly preferably 0 mol % or more but 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 constituent 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 the present 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 %, relative to 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) exhibits 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 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) preferably contains 10 to 90 mol %, and 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, a polyester resin 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 may be used.

[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, that 5 to 90 mol % of units derived from 1,4-cyclohexanedimethanol, and that 0 to 90 mol % of units derived from ethylene glycol. From the same 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 Structural Units) 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 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 Color Index Solvent Red 2. The compound of formula (6) corresponds to Color Index Solvent Blue 104.

[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 a combination of a compound of formula (3) and a compound of formula (4) with a ratio of (3):(4)=99-50:1-50, particularly 70-50:30-50. In the combination of a compound of formula (6) and a compound of formula (5), a ratio of (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 99-50:1-50, particularly 70-50:30-50.

[0035] The content of dye (B) may be appropriately determined depending on the type of polyester resin, the type of dye, etc. 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, particularly preferably 7.0 ppm or less. That is, the range of the content of dye (B) is preferably 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] The method of addition is not particularly limited, but 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, 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 dye (B). Using multiple dyes effectively suppresses yellowing and mechanical strength loss upon UV irradiation without impairing color tone. Addition of a UV absorber is a commonly known method for improving the UV resistance of resins. However, according to the inventors' studies, as the amount of UV absorber added increases, absorbance in the UV region increases, which is expected to suppress photodegradation of the resin. However, it also tends to cause a decrease in mechanical strength and may cause surface roughness due to bleed-out of the UV absorber, which may become the starting point for fracture. Furthermore, UV absorbers primarily absorb light in the UV region (short wavelength region of visible light), causing yellowing of the resin and making them unsuitable for transparent applications. Dye (B) is believed to improve UV resistance without impairing color tone, without the concerns associated with the use of UV absorbers.

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

[0039] The 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. Furthermore, the optional components may include resins and oligomers such as polyolefin resins, polyester resins other than the polyester resin (A), polyamide resins, polycarbonate resins, acrylonitrile resins, vinyl chloride resins, vinyl acetate resins, polyacrylic acid resins, polymethacrylic acid 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, the 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 formed into a flat plate having a thickness of 2.0 mm by injection molding, 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 amount per irradiation: 2,265 mJ / cm ２ When the film is irradiated with UV light a total of 48 times using a UV irradiator such as a UV irradiator 1000 W or a UV irradiator 2000 W or a UV irradiator 3000 W or a UV irradiator 4000 W or a UV irradiator 5000 W or a UV irradiator 6000 W or a UV irradiator 7000 W or a UV irradiator 8000 W or a UV irradiator 9000 W or a UV irradiator 1 ...2000 W or a UV irradiator 13000 W or a UV irradiator 14000 W or a UV irradiator 15000 W or a UV irradiator 16000 W or a UV irradiator 17000 W or

[0045] The polyester resin composition of the present embodiment can be injection molded into a dumbbell piece 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 amount per irradiation: 2,265 mJ / cm ２ When the film is irradiated with UV light a total of 48 times using a UV irradiator such as a UV irradiator 1000 W or a UV irradiator 2000 W or a UV irradiator 3000 W or a UV irradiator 4000 W or a UV irradiator 5000 W or a UV irradiator 6000 W or a UV irradiator 7000 W or a UV irradiator 8000 W or a UV irradiator 9000 W or a UV irradiator 1 ...2000 W or a UV irradiator 3000 W or a UV irradiator 4000 W or a UV irradiator 5000 W or a UV irradiator

[0046] <Uses of Polyester Resin Composition> The polyester resin composition of this embodiment can be used to produce various molded articles. For example, it can be used for injection-molded articles, extrusion-molded articles such as sheets, films, and pipes, bottles, foams, pressure-sensitive adhesives, adhesives, paints, and the like. More specifically, the injection-molded articles may be insert-molded or two-color-molded. The sheets may be single-layered or multi-layered, and the films may be single-layered or multi-layered, and may be unstretched, stretched in one direction, or stretched in two directions, or may be laminated to a steel plate or the like. The films may be inflation-molded. The bottles may be direct-blown bottles, injection-blown bottles, or injection-molded bottles. The foams may be bead foams or extrusion foams. The polyester resin composition of this embodiment is particularly suitable for applications expected to be used in environments exposed to ultraviolet light, 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.

[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 Value After conditioning the humidity of the flat plates obtained in the Examples and Comparative Examples described below for 48 hours, the Lab value of the Hunter color system was measured in an atmosphere of 23°C and 50% relative humidity. The measuring device used was a haze 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 based on the following criteria.

[0049] (2) Yellowing Resistance The flat plates obtained in the examples and comparative examples described below were subjected to 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 amount per irradiation: 2,265 mJ / 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.

[0050] (3) Decrease in mechanical strength The dumbbell pieces obtained in the examples and comparative examples described below were subjected to a belt conveyor-type UV irradiation machine (light source: high-pressure mercury lamp, irradiation peak intensity (lamp distance 180 mm): 319 mW / cm ２ , Accumulated light amount per irradiation: 2,265 mJ / 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.

[0051] [Synthesis of SH] A 30-liter polyester production apparatus equipped with a packed column rectification column, a partial condenser, a total condenser, a cold trap, a stirrer, a heating device, and a nitrogen inlet tube was charged with 38.3 moles of dimethyl 2,6-naphthalenedicarboxylate, 17.9 moles of ethylene glycol, 22.9 moles of 1,4-cyclohexanedimethanol, and 17.9 moles of spiroglycol as raw material monomers. 0.005 mole % of tetra-n-butoxytitanium and 0.02 mole % of potassium acetate were added to the dimethyl 2,6-naphthalenedicarboxylate, and the temperature was raised 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 mole % of germanium dioxide and 0.05 mole % of triethyl phosphate were added to the dicarboxylic acid component. The temperature was gradually raised and the pressure was gradually reduced, and polycondensation was finally carried out at 280°C and 0.1 kPa or less. The reaction was terminated when an appropriate melt viscosity was reached, to obtain a polyester resin (SH resin).

[0052] [Synthesis of SC] A 30-liter polyester production apparatus equipped with a packed rectification column, partial condenser, total condenser, cold trap, agitator, heater, and nitrogen inlet tube was charged with raw monomers: 51.2 mol of dimethyl terephthalate, 0.15 mol of trimethyl trimellitate, 44.1 mol of ethylene glycol, 48.4 mol of 1,4-cyclohexanedimethanol, and 5.4 mol of spiroglycol. 0.010 mol% of tetra-n-butoxytitanium and 0.02 mol% of potassium acetate were added to the dicarboxylic acid component, and the temperature was raised 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, 0.10 mol% of germanium dioxide and 0.05 mol% of triethyl phosphate were added to the dicarboxylic acid component. The temperature was gradually raised and the pressure was gradually reduced, and polycondensation was finally carried out at 285°C and 0.1 kPa or less. The reaction was terminated when an appropriate melt viscosity was reached, to obtain a polyester resin (SC resin).

[0053] [Example 1] (Preparation of kneaded pellets) Using a twin-screw kneading extruder (manufactured by Toshiba Machine Co., Ltd., model: TEM26SX, screw diameter: 26 mmφ, L / D: 48), a polyester resin and various additives were dry-blended according to the composition shown in Table 4 and charged from a 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 kneaded pellets were then injection molded to obtain 2.0 mm thick plates and dumbbell pieces conforming to ISO 527. For injection molding, an injection molding machine, Model: J85AD, manufactured by The Japan Steel Works, Ltd., was used, and molding was carried out under conditions of a cylinder temperature of 245 to 280°C and a mold temperature of 15 to 50°C. Using the molded plates and dumbbell pieces, Lab value measurements, yellowing resistance tests, and mechanical strength degradation resistance tests were carried out. 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.

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

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 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: 【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, 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. 2. The polyester resin composition according to claim 1, 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 claim 1 or 2, wherein the dye (B) is two or more dyes selected from the group consisting of compounds represented by the following formulas (3) to (6): 【Chemistry 3】

4. The polyester resin composition according to claim 1 or 2, comprising the dye (B) in an amount of 3.0 ppm or more and 10 ppm or less.

5. 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.

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

7. 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 mass %.

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

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

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

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