Polyester resin composition and molded article thereof

Abstract

Provided is a polyester resin composition containing a polyester resin (A) and a dye (B), the polyester resin (A) having a dicarboxylic acid structural unit and a diol structural unit, the dicarboxylic acid structural unit being terephthalic acid units and / or 2,6-naphthalene dicarboxylic acid units, 5 to 90 mol% of the diol structural unit being units represented by general formula (1) or (2), and 5 to 90 mol% of the diol structural unit being units derived from an alicyclic diol, the dye (B) being obtained by combining two or more dyes having a structure containing at least two secondary amino groups and at least one benzene ring.

Description

Technical Field

[0001] This invention relates to polyester resin compositions and molded articles such as baby bottles using the polyester resin compositions. Background Technology

[0002] Aromatic saturated polyester resins, especially polyethylene terephthalate (PET), are resins with a good balance of mechanical properties, solvent resistance, aroma retention, weather resistance, and reusability, and are widely used primarily for bottles and films. However, PET has drawbacks regarding crystallinity and heat resistance. Specifically, regarding crystallinity, due to its high crystallinity, PET whitens and impairs transparency when manufacturing thick molded bodies or sheets due to crystallization. Furthermore, regarding heat resistance, since PET's glass transition temperature is around 80°C, it is not suitable for applications requiring high heat resistance and transparency, such as automotive interiors, import / export packaging materials, food packaging materials requiring retort or microwave heating, and baby bottles or tableware requiring heat sterilization.

[0003] Therefore, currently, in applications requiring transparency, low-crystallinity polyester resins such as PET partially copolymerized with 1,4-cyclohexanediethanol or PET partially modified with isophthalic acid are also used. However, while the transparency of PET partially copolymerized with 1,4-cyclohexanediethanol or PET partially modified with isophthalic acid is improved compared to PET, these resins have a glass transition temperature of around 80°C and poor heat resistance.

[0004] In addition, for applications requiring heat resistance, polyester resins with high glass transition temperatures, such as polyethylene 2,6-naphthalenedicarboxylate (hereinafter sometimes referred to as "PEN") or poly(1,4-cyclohexanedimethyl terephthalate), are used. However, while PEN or poly(1,4-cyclohexanedimethyl terephthalate) can also improve heat resistance, they are highly crystallinity and have poor transparency.

[0005] In addition, as a polyester resin that maintains high transparency and improves the heat resistance of PET or PEN, a polyester resin containing a diol having a cyclic acetal backbone has been proposed (Patent Documents 1 and 2). This polyester resin can be used in applications requiring both transparency and heat resistance.

[0006] However, in areas such as baby bottles that were previously sterilized by boiling, the widespread use of household UV sterilization devices in recent years has made UV sterilization a common sterilization method. In addition, due to increasing societal demands for ESG and SDGs, there is a trend towards simplifying packaging for items such as baby bottles (from cardboard boxes to simple shrink wrap).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2017-105873

[0010] Patent Document 2: International Publication No. 2020 / 218324 Summary of the Invention

[0011] The technical problem that the invention aims to solve

[0012] Therefore, it is required to impart UV resistance to polyester resins to suppress degradation such as reduced strength or color changes caused by UV irradiation from UV sterilization equipment, fluorescent lamps, or sunlight during store displays. Furthermore, when imparting UV resistance, it is also required that the color tone of the thermoplastic polyester resin not be impaired (or that the color tone be improved).

[0013] Technical solutions for solving technical problems

[0014] After careful research, the inventors of this invention discovered that by combining two or more dyes with specific structures into a polyester resin having a prescribed composition, UV resistance can be imparted without damaging the hue of the polyester resin, thus completing this invention.

[0015] That is, the present invention includes the following methods.

[0016] [1] A polyester resin composition, characterized in that:

[0017] It contains polyester resin (A) and dye (B).

[0018] The aforementioned polyester resin (A) has dicarboxylic acid structural units and diol structural units.

[0019] The dicarboxylic acid structural units mentioned above are terephthalic acid units and / or 2,6-naphthalenedicarboxylic acid units.

[0020] 5-90 mol% of the aforementioned diol structural units are units derived from diols having a cyclic acetal skeleton as shown in general formula (1) or general formula (2), and 5-90 mol% of the aforementioned diol structural units are units derived from alicyclic diols.

[0021] The dye (B) mentioned above is obtained by combining two or more dyes having a structure containing at least two secondary amino groups and at least one benzene ring.

[0022]

[0023] (In equation (1), R) 1 and R 2These can be used independently to represent aliphatic groups with 1 to 10 carbon atoms, alicyclic groups with 3 to 10 carbon atoms, or aromatic groups with 6 to 10 carbon atoms.

[0024]

[0025] (In equation (2), R) 1 The meaning is the same as above, R 3 This refers to an aliphatic group with 1 to 10 carbon atoms, an alicyclic group with 3 to 10 carbon atoms, or an aromatic group with 6 to 10 carbon atoms.

[0026] [2] The polyester resin composition as described in [1] above, wherein the dye (B) is a dye selected from two or more colors of CI (dye index) Solvent Blue RR, Solvent Blue 97, Solvent Blue 104, Solvent Violet 36 and Reactive Red 2.

[0027] [3] The polyester resin composition as described in [1] above, wherein the dye (B) is selected from two or more dyes selected from the compounds shown in the following formulas (3) to (6).

[0028]

[0029] [4] The polyester resin composition as described in any one of [1] to [3] above, wherein the dye (B) is contained in an amount of 3.0 ppm to 10 ppm or less.

[0030] [5] The polyester resin composition as described in 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-cyclohexanediethanol.

[0031] [6] The polyester resin composition as described in any one of [1] to [5] above, wherein the dicarboxylic acid structural unit is a 2,6-naphthalenedicarboxylic acid unit.

[0032] [7] The polyester resin composition as described in any one of [1] to [6] above, wherein the content of polycarbodiimide contained in the polyester resin composition is less than 0.1% by mass.

[0033] [8] A molded article that uses the polyester resin composition described in any one of [1] to [7] above.

[0034] [9] A container that uses the polyester resin composition described in any one of [1] to [8] above.

[0035]

[10] A baby bottle that uses the polyester resin composition described in any one of [1] to [9] above.

[0036] Invention Effects

[0037] The polyester resin composition of the present invention is endowed with UV resistance without loss of color. Detailed Implementation

[0038] The following is a detailed description of specific embodiments of the present invention (hereinafter referred to as "this embodiment"). This embodiment is merely an illustration of the present invention and is not intended to limit the invention to the following content. The present invention can be implemented with appropriate modifications within its spirit and scope.

[0039] <Polyester Resin Composition>

[0040] The polyester resin composition of this embodiment contains polyester resin (A) and dye (B).

[0041] [Polyester Resin (A)]

[0042] Polyester resin (A) has dicarboxylic acid structural units and diol structural units.

[0043] (Diol structural unit)

[0044] 5 to 90 mol% of the diol structural units in the polyester resin (A) are units of diols having a cyclic acetal skeleton as shown in general formula (1) or general formula (2) below, and 5 to 90 mol% of the diol structural units are units of alicyclic diols.

[0045]

[0046]

[0047] In equations (1) and (2) above, R 1 and R 2 Each group is 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, preferably selected from methylene, ethylene, propylene, butylene and their structural isomers, such as isopropylene and isobutylene.

[0048] R 3 It 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, preferably selected from methyl, ethyl, propyl, butyl and their structural isomers, such as isopropyl and isobutyl.

[0049] As a diol having a cyclic acetal skeleton as shown in the above formula (1), 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (also known as spirocyclic diol) is particularly preferred.

[0050] As a diol having a cyclic acetal skeleton as shown in formula (2) above, 5-hydroxymethyl-5-ethyl-2-(1,1-dimethyl-2-hydroxyethyl)-1,3-dioxane is particularly preferred.

[0051] The units derived from alicyclic diols in the diol structural units of polyester resin (A) are not particularly limited. Examples of units derived from diols such as 1,3-cyclohexanediethanol, 1,4-cyclohexanediethanol, 1,2-decahydronaphthalenediethanol, 1,3-decahydronaphthalenediethanol, 1,4-decahydronaphthalenediethanol, 1,5-decahydronaphthalenediethanol, 1,6-decahydronaphthalenediethanol, 2,7-decahydronaphthalenediethanol, tetrahydronaphthalenediethanol, norbornenediethanol, tricyclodecanediethanol, and pentacyclododecanediethanol are preferred. Units derived from 1,4-cyclohexanediethanol, norbornenediethanol, tricyclodecanediethanol, and 2,6-decahydronaphthalenediethanol are particularly preferred.

[0052] In this embodiment, the preferred diol having a cyclic acetal skeleton is 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (spirocyclic diol), and the preferred alicyclic diol is 1,4-cyclohexanediethanol.

[0053] The diol structural unit in this embodiment may also contain diol structural units other than diol units having a cyclic acetal skeleton and alicyclic diol units. The content of other diol structural units relative to 100 mol% of the diol structural unit can be 0 to 90 mol%, preferably 0 to 70 mol%, more preferably 0 to 50 mol%, and particularly preferably 0 mol% or more and less than 50 mol%. Other diol structural units can be exemplified by units derived from: aliphatic diols such as ethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, propylene glycol, and neopentanediol; polyether compounds such as polyethylene glycol, polypropylene glycol, and polybutanediol; bisphenols such as 4,4'-(1-methylethylidene)bisphenol, methylene bisphenol (bisphenol F), 4,4'-cyclohexylene bisphenol (bisphenol Z), and 4,4'-sulfonyl bisphenol (bisphenol S); epoxide adducts of the above bisphenols; aromatic dihydroxy compounds such as hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, and 4,4'-dihydroxydiphenylbenzophenone; and epoxide adducts of the above aromatic dihydroxy compounds. Considering the mechanical strength, heat resistance, and availability of polyester resins, units derived from ethylene glycol are preferred when other diol structural units are included.

[0054] (Dicarboxylic acid structural unit)

[0055] The dicarboxylic acid structural unit in the polyester resin (A) comprises a terephthalic acid unit and / or a 2,6-naphthalenedicarboxylic acid unit. The terephthalic acid unit refers to a unit derived from terephthalic acid. The 2,6-naphthalenedicarboxylic acid unit refers to a unit derived from 2,6-naphthalenedicarboxylic acid. Examples of terephthalic acid units include units derived from terephthalic acid and dimethyl terephthalate. Preferably, the dicarboxylic acid structural unit is a 2,6-naphthalenedicarboxylic acid unit.

[0056] In addition, without compromising the purpose of this embodiment, the dicarboxylic acid structural unit may also include other dicarboxylic acid structural units. Other dicarboxylic acid structural units are not limited to the following units, but can be listed as follows: units derived from aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, decahydronaphthalenedicarboxylic acid, norbornanedicarboxylic acid, tricyclodecanedicarboxylic acid, pentacyclododecanedicarboxylic acid, 3,9-bis(1,1-dimethyl-2-carboxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 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 tetrahydronaphthalenedicarboxylic acid.

[0057] In this embodiment, from the viewpoint of fully improving the balance of physical properties such as transparency, heat resistance, impact resistance and mechanical strength of polyester resin (A), it is preferable to contain 80 to 100 mol% of terephthalic acid units and / or 2,6-naphthalenedicarboxylic acid units relative to 100 mol% of dicarboxylic acid structural units, more preferably 90 to 100 mol%, and particularly preferably 100 mol%.

[0058] In polyester resin (A), relative to 100 mol% of all diol structural units, it contains 5 to 90 mol% of units derived from the aforementioned diols having a cyclic acetal backbone. This results in decreased crystallinity, a higher glass transition temperature, and consequently, high transparency and high heat resistance. Compared to other polyester resins such as PET, polybutylene terephthalate, and polylactic acid, where 100 mol% of the diol structural units are derived from ethylene glycol and 1,4-cyclohexanediol, polyester resin (A) also exhibits a good balance between transparency and heat resistance. From the same perspective, polyester resin (A) preferably contains 15 to 80 mol%, more preferably 20 to 70 mol% of units derived from the aforementioned diols having a cyclic acetal backbone.

[0059] In the polyester resin (A), relative to 100 mol% of all diol structural units, it contains 5 to 90 mol% of the aforementioned units derived from alicyclic diols. In this embodiment, from the viewpoint of further improving the impact resistance of the polyester resin (A), it is preferable to contain 10 to 90 mol% of units derived from alicyclic diols, and more preferably 15 to 90 mol%.

[0060] In this embodiment, from the viewpoint of impact resistance, a polyester resin (A) in which 15 to 50 mol% of the diol structural units are derived from diols having a cyclic acetal backbone and 15 to 85 mol% are derived from alicyclic diols can be cited as an example.

[0061] In this embodiment, particularly considering the balance of transparency, heat resistance, impact resistance, and mechanical strength, it is preferred that 100 mol% of the dicarboxylic acid structural units in the polyester resin (A) are terephthalic acid units and / or 2,6-naphthalenedicarboxylic acid units, and that 5 to 90 mol% of the diol structural 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-cyclohexanediethanol, and 0 to 90 mol% of units derived from ethylene glycol. From the same point of view, it is particularly preferred that 100 mol% of the dicarboxylic acid structural 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 structural 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-cyclohexanediethanol, and 0 to 70 mol% are units derived from ethylene glycol.

[0062] (Other structural units)

[0063] In the polyester resin (A), without prejudice to the purpose of this embodiment, it may also contain monohydric alcohol units such as butanol, hexanol, and octanol, or polyhydric alcohol units with three or more ions such as trimethylolpropane, glycerol, 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 trimellitic acid, trimellitic anhydride, and pyromellitic acid, and oxyacid units such as glycolic acid, lactic acid, hydroxybutyric acid, 2-hydroxyisobutyric acid, and hydroxybenzoic acid.

[0064] The method for manufacturing the polyester resin of this embodiment is not particularly limited, and existing known methods can be used. Examples include melt polymerization methods such as transesterification and direct esterification, or solution polymerization. Various known compounds can also be used as transesterification catalysts, esterification catalysts, etherification inhibitors, heat stabilizers, light stabilizers, and polymerization regulators.

[0065] [Dye (B)]

[0066] The dye (B) in this embodiment is obtained by combining 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 having a structure containing at least two secondary amino groups and at least one benzene ring, and various known dyes can be used.

[0067] The preferred dye (B) is two or more dyes selected from the compounds shown in formulas (3) to (6) below, more preferably a combination of (3) or (6) and (4) or (5), particularly preferably a combination of the compound of formula (3) and the compound of formula (4), or a combination of the compound of formula (5) and the compound of formula (6), and most preferably a combination of the compound of formula (3) and the compound of formula (4). The compound of formula (3) corresponds to Dye Index Solvent Blue RR and Dye Index Solvent Blue 97. The compound of formula (4) corresponds to Dye Index Solvent Violet 36. The compound of formula (5) corresponds to Reactive Red 2. The compound of formula (6) corresponds to Solvent Blue 104.

[0068]

[0069] The preferred mixing ratio (unit: mass) is (3) or (6): (4) or (5) = 99-50: 1-50, particularly 70-50: 30-50. In the case of a combination of compounds of formula (3) and formula (4), (3): (4) = 99-50: 1-50, particularly 70-50: 30-50. In the case of a combination of compounds of formula (6) and formula (5), (6): (5) = 99-50: 1-50, particularly 70-50: 30-50.

[0070] Furthermore, dye (B) is preferably selected from two or more dyes chosen from CI (Dye Index) Solvent Blue RR, Solvent Blue 97, Solvent Blue 104, Solvent Violet 36, and Reactive Red 2; more preferably, it is a combination of at least one dye chosen from Solvent Blue RR, Solvent Blue 97, and Solvent Blue 104 and at least one dye chosen from Solvent Violet 36 and Reactive Red 2. Particularly preferred 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. Most preferably, it is a combination of Solvent Blue RR and Solvent Violet 36, or a combination of Solvent Blue 97 and Solvent Violet 36.

[0071] As a mixing ratio (unit: mass), it is preferably at least one selected from Solvent Blue RR, Solvent Blue 97, and Solvent Blue 104 : at least one selected from Solvent Violet 36 and Reactive Red 2 = 99-50 : 1-50, particularly preferably 70-50 : 30-50. In the case of a combination of Solvent Blue RR and Solvent Violet 36, it is preferably Solvent Blue RR : Solvent Violet 36 = 99-50 : 1-50, particularly preferably 70-50 : 30-50. In the case of a combination of Solvent Blue 97 and Solvent Violet 36, it is preferably Solvent Blue 97 : Solvent Violet 36 = 99-50 : 1-50, particularly preferably 70-50 : 30-50. In the case of a combination of Reactive Red 2 and Solvent Blue 104, it is preferably Solvent Blue 104 : Reactive Red 2 = 99-50 : 1-50, particularly preferably 70-50 : 30-50.

[0072] The content of dye (B) can be appropriately determined based on the type of polyester resin and the type of dye. 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 range of dye (B) content is preferably selected from 0.5–10 ppm, 0.5–7.5 ppm, 0.5–7.0 ppm, 2.0–10 ppm, 2.0–7.5 ppm, 2.0–7.0 ppm, 3.0–10 ppm, 3.0–7.5 ppm, and 3.0–7.0 ppm, 3.2–10 ppm, 3.2–7.5 ppm, and 3.2–7.0 ppm.

[0073] There are no particular limitations on the method of addition, but it is preferable to use an extruder for melt mixing. In this case, a high concentration of dye (B) can be melt-mixed with polyester resin (A) to produce a masterbatch, which is then diluted to a specified concentration for use during molding.

[0074] As described above, polyester resin (A) is a material that exhibits excellent properties in terms of heat resistance, transparency, and impact resistance. Furthermore, in the polyester resin composition of this embodiment, the dye (B) contains two or more dyes having the specific structures described above. By using multiple dyes, yellowing and a decrease in mechanical strength under UV irradiation can be effectively suppressed without compromising the hue.

[0075] A known method for improving the UV resistance of resins is to add UV absorbers. However, according to the inventors' research, while increasing the amount of UV absorber increases the absorbance in the UV region and can inhibit photodegradation of the resin, it also leads to a decrease in mechanical strength. Furthermore, the surface roughening caused by the exudation of UV absorbers can sometimes become a starting point for damage. In addition, UV absorbers mainly absorb light in the UV region (the short wavelength region of visible light), which is the cause of the resin's yellow coloration, thus making it unsuitable for transparent applications.

[0076] It is believed that dye (B) need not worry about the problems caused by the use of UV absorbers mentioned above, and can improve UV resistance without damaging the hue.

[0077] [Any ingredient]

[0078] In the polyester resin composition of this embodiment, in addition to polyester resin (A) and dye (B), any other components may be added.

[0079] As an optional component, it is not limited to the following components, but may include, for example, various additives and molding aids such as antioxidants, light stabilizers, plasticizers, extenders, matting agents, drying conditioners, antistatic agents, anti-settling agents, surfactants, flow modifiers, drying oils, waxes, fillers, reinforcing agents, surface smoothers, leveling agents, and curing reaction accelerators. Furthermore, as an optional component, it may include resins and oligomers such as polyester resins other than polyolefin resins and polyester resins (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.

[0080] The content of any component is not particularly limited. From the viewpoint of ensuring good heat resistance and transparency, improving impact resistance, 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.

[0081] However, when polycarbodiimide is included as an optional component, its content is preferably less than 0.1% by mass. Most preferably, it is substantially free of polycarbodiimide.

[0082] When 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, it is substantially pigment-free. Here, pigment content refers to the amount of pigment contained in the resin. In the case of a molded article made of resin, the amount of pigment coated on the surface of the molded article is not used in the calculation of pigment content.

[0083] [physical properties]

[0084] Regarding the polyester resin composition of this embodiment, a 2.0 mm thick plate is formed by injection molding. After 48 hours of humidification, the L value measured at 23°C and 50% relative humidity is preferably 92.0 or higher, and particularly preferably 93.5 or higher. Furthermore, the a value measured using the same method is preferably -0.1 or higher and less than 0.6, and particularly preferably 0.1 or higher and less than 0.4. Additionally, the b value measured using the same method is preferably -2.6 or higher and less than 1.1, and particularly preferably -1.5 or higher and less than 0.0.

[0085] Furthermore, regarding the polyester resin composition of this embodiment, a 2.0 mm thick flat plate was formed by injection molding, using, for example, a conveyor-type UV irradiation machine (light source: high-pressure mercury lamp, peak irradiation intensity (lamp distance 180 mm): 319 mW / cm²). 2 Cumulative light intensity per irradiation: 2,265 mJ / cm² 2 When a total of 48 UV irradiations are performed using a UV irradiation machine, the change in 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 described above is preferably 1.5 or less, and particularly preferably 1.1 or less.

[0086] Furthermore, regarding the polyester resin composition of this embodiment, dumbbell plates based on ISO 527 are manufactured by injection molding, using, for example, a conveyor-type UV irradiation machine (light source: high-pressure mercury lamp, peak irradiation intensity (lamp distance 180mm): 319mW / cm). 2 Cumulative light intensity per irradiation: 2,265 mJ / cm² 2 When a UV irradiation machine is used to perform a total of 48 UV irradiations, the change in tensile elongation at break Δ (tensile elongation at break after UV irradiation - tensile elongation before UV irradiation) before and after UV irradiation is preferably -13 or more, and particularly preferably -5 or more.

[0087] <Uses of Polyester Resin Compositions>

[0088] The polyester resin composition of this embodiment can be used to manufacture various molded articles. For example, it can be used for injection molded articles, sheets, films, tubes, extruded articles, bottles, foams, adhesives, bonding agents, coatings, etc. More specifically, the injection molded articles can be insert molding or two-color molding. The sheets can be single-layer or multi-layer, the films can be single-layer or multi-layer, they can be unstretched films or films stretched in one or two directions, and they can be laminated on steel plates, etc. The films can also be blow-molded. The bottles can be direct blow-molded bottles, injection blow-molded bottles, or injection-molded bottles. The foams can be bead foams or extruded foams. It is particularly suitable for applications intended for use in environments where the product is exposed to ultraviolet light, such as products used in automobiles, import and export packaging materials, food packaging materials, containers for baby bottles and tableware, etc. In other words, it can be said that the polyester injection molded articles, polyester extruded articles, polyester foams, polyester containers, polyester bottles, polyester tableware, and polyester baby bottles of this embodiment each 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 made into various known forms according to various uses.

[0089] Example

[0090] The following examples illustrate this implementation in more detail, but this implementation is not limited to these examples.

[0091] [Evaluation Method]

[0092] (1) Lab value

[0093] After 48 hours of conditioning, the plates obtained in the examples and comparative examples described later were used to measure the Lab values ​​of the Hunter color series at 23°C and 50% relative humidity. The measuring apparatus used was a haze measuring apparatus (model: COH-300A) manufactured by Nippon Denshoku Kogyo Co., Ltd. The apparatus used was based on JIS-K-7105 and ASTM D1003. Scores were recorded according to the following standards.

[0094] [Table 1]

[0095]

[0096] (2) Resistance to yellowing

[0097] For the flat plates obtained in the embodiments and comparative examples described later, a conveyor belt UV irradiation machine (light source: high-pressure mercury lamp, peak irradiation intensity (lamp distance 180mm): 319mW / cm²) was used. 2 Cumulative light intensity per irradiation: 2,265 mJ / cm² 2A total of 48 UV irradiations were performed. The b-values ​​of the plate before and after UV irradiation were measured using the same method as in (1), and the change Δ (b-value after UV irradiation - b-value before UV irradiation) was calculated. The scores were recorded according to the following benchmarks.

[0098] [Table 2]

[0099]

[0100] (3) Reduced mechanical strength

[0101] The dumbbell plates obtained in the embodiments and comparative examples described later were subjected to UV irradiation using a conveyor belt type (light source: high-pressure mercury lamp, peak irradiation intensity (lamp distance 180mm): 319mW / cm²). 2 Cumulative light intensity per irradiation: 2,265 mJ / cm² 2 A total of 48 UV irradiations were performed. Using a Strograph APIII from Toyo Seiki Co., Ltd., the elongation at break before and after UV irradiation was measured, and the change Δ (elongation at break after UV irradiation – elongation at break before UV irradiation) was calculated. Scores were recorded according to the following criteria.

[0102] [Table 3]

[0103]

[0104] [Synthesis of SH]

[0105] In a 30-liter polyester manufacturing unit equipped with a packed column distillation column, a condenser, a total condenser, a cold trap, a stirrer, a heating device, and a nitrogen inlet pipe, 38.3 mol of dimethyl 2,6-naphthalenedicarboxylate, 17.9 mol of ethylene glycol, 22.9 mol of 1,4-cyclohexanediethanol, and 17.9 mol of spirocyclohexanediol were added as raw material monomers. Relative to dimethyl 2,6-naphthalenedicarboxylate, 0.005 mol% tetrabutoxytitanium and 0.02 mol% potassium acetate were added. The mixture was heated to 225°C under a nitrogen atmosphere to carry out a transesterification reaction. After the conversion rate of the dicarboxylic acid component reached over 90%, relative to the dicarboxylic acid component, 0.025 mol% germanium dioxide and 0.05 mol% triethyl phosphate were added, and the temperature was slowly increased and the pressure reduced until polycondensation was carried out at 280°C and below 0.1 kPa. The reaction was terminated when an appropriate melt viscosity was reached to obtain polyester resin (SH resin).

[0106] [Synthesis of SC]

[0107] In a 30-liter polyester manufacturing unit equipped with a packed column distillation column, a condenser, a total condenser, a cold trap, a stirrer, a heating device, and a nitrogen inlet pipe, 51.2 mol of dimethyl terephthalate, 0.15 mol of trimethyl trimellitate, 44.1 mol of ethylene glycol, 48.4 mol of 1,4-cyclohexanediol, and 5.4 mol of spirocyclodiol were added as raw material monomers. Relative to the dicarboxylic acid composition, 0.010 mol% of tetra-n-butoxytitanium and 0.02 mol% of potassium acetate were added. The mixture was heated to 225°C under a nitrogen atmosphere to carry out a transesterification reaction. After the conversion rate of the dicarboxylic acid composition reached over 90%, relative to the dicarboxylic acid composition, 0.10 mol% of germanium dioxide and 0.05 mol% of triethyl phosphate were added, and the temperature was slowly increased and the pressure reduced until polycondensation was carried out at 285°C and below 0.1 kPa. The reaction was terminated when an appropriate melt viscosity was reached to obtain polyester resin (SC resin).

[0108] [Example 1]

[0109] (Preparation of compounded granules)

[0110] Using a twin-screw compounding extruder (manufactured by Toshiba Machine Co., Ltd., model: TEM26SX, screw diameter: 26mmφ, L / D: 48), polyester resin and various additives were dry-mixed according to the composition shown in Table 4 and fed from the hopper. The extruded material was extruded under the conditions of barrel temperature 180–260°C, die temperature 260°C, screw speed 75 rpm, and ejection rate 15 kg / h. After water cooling, the mixture was granulated to obtain polyester resin composition granules.

[0111] (Injection molding of compounded granules)

[0112] Next, the obtained compounded granules were injection molded to obtain flat plates with a thickness of 2.0 mm and dumbbell plates based on ISO 527. Injection molding was performed using an injection molding machine manufactured by Nippon Steel Co., Ltd., model J85AD, at a barrel temperature of 245–280°C and a mold temperature of 15–50°C. Lab value determination, yellowing resistance testing, and mechanical strength reduction resistance testing were conducted using the molded flat plates and dumbbell plates. The results are shown in Table 4.

[0113] [Examples 2-6]

[0114] Using the composition shown in Table 4, except for the procedures described in Example 1, the flat plate and dumbbell plates were manufactured and evaluated. The results are shown in Table 4.

[0115] [Comparative Examples 1-13]

[0116] Using the composition shown in Table 4, except for the procedures described in Example 1, the flat plate and dumbbell plates were manufactured and evaluated. The results are shown in Table 4.

[0117] The composition and characteristics of the test pieces (flat plates and dumbbell plates) obtained in Examples 1-6 and Comparative Examples 1-13 are shown.

[0118] [Table 4]

[0119]

[0120] The structures of the additives in Table 4 above are shown below.

[0121]

Claims

1. A polyester resin composition, characterized in that: It contains polyester resin (A) and dye (B). The polyester resin (A) has dicarboxylic acid structural units and diol structural units. The dicarboxylic acid structural 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 diols having a cyclic acetal skeleton as shown in general formula (1) or general formula (2), and 5 to 90 mol% of the diol structural units are units derived from alicyclic diols. The dye (B) is a combination of Solvent Blue 97 and Solvent Violet 36, or a combination of Reactive Red 2 and Solvent Blue 104. The mass ratio of Solvent Blue 97 to Solvent Violet 36 is 70-50:30-50. The mass ratio of Reactive Red 2 to Solvent Blue 104 is Solvent Blue 104:Reactive Red 2 = 70-50:30-50. The content of the dye (B) is between 0.5 ppm and 10 ppm. In equation (1), R 1 and R 2 Each can be used independently to represent an aliphatic group with 1 to 10 carbon atoms, an alicyclic group with 3 to 10 carbon atoms, or an aromatic group with 6 to 10 carbon atoms. In equation (2), R 1 The meaning is the same as above, R 3 It represents an aliphatic group with 1 to 10 carbon atoms, an alicyclic group with 3 to 10 carbon atoms, or an aromatic group with 6 to 10 carbon atoms.

2. The polyester resin composition according to claim 1, characterized in 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, and the alicyclic diol is 1,4-cyclohexanediethanol.

3. The polyester resin composition according to claim 1 or 2, characterized in that: The dicarboxylic acid structural unit is a 2,6-naphthalenedicarboxylic acid unit.

4. The polyester resin composition according to claim 1 or 2, characterized in that: The content of polycarbodiimide in the polyester resin composition is less than 0.1% by mass.

5. A molded article, characterized in that: The polyester resin composition according to claim 1 or 2 was used.

6. A container, characterized in that: The polyester resin composition according to claim 1 or 2 was used.

7. A baby bottle, characterized in that: The polyester resin composition according to claim 1 or 2 was used.

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