Polyester resin, its use, and molded body, cosmetic container, and cosmetic product

Abstract

This polyester resin comprises a polymer of (A) an acid component and (B) an alcohol component. The component (A) comprises (A1) a terephthalic acid component in an amount of 72 mol% or more and (A2) an isophthalic acid component in an amount of 8 to 28 mol% both related to the whole amount of the component (A). The component (B) comprises (B1) an ethylene glycol component in an amount of 77 mol% or more, (B2) a 2,2-dimetyl-1,3-propanediol component in an amount of 4 to 18 mol% and (B3) a diethylene glycol component in an amount of 5 mol% or less all relative to the whole amount of the component (B). The total of the ratio of the content of the component (A2) to the content of the component (A) and the ratio of the content of the component (B2) to the content of the component (B) is 24 to 43 mol%.

Description

Polyester resin, its use, and cosmetic containers and cosmetic products Related Applications

[0001] The present invention is based on the priority claim of Japanese Patent Application No. 2021-80464 (filed May 11, 2021), the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a polyester resin and a method of using the same. The present disclosure also relates to a cosmetic container having the polyester resin and a cosmetic product using the cosmetic container.

[0003] Polyethylene terephthalate (PET), a copolymer of terephthalic acid and ethylene glycol, is used in a variety of applications. Polyester resins are known that have polyethylene terephthalate as the main structure and are partially copolymerized with neopentyl glycol as an alcohol component (see, for example, Patent Documents 1 and 2).

[0004] The copolymer polyester resin described in Patent Document 1 contains 100 mol % of terephthalic acid as a dicarboxylic acid component, and 79 to 94.5 mol % of ethylene glycol, 3.0 to 20.0 mol % of neopentyl glycol, and 1.0 to 2.5 mol % of diethylene glycol as glycol components, and has an intrinsic viscosity of 0.77 dL / g to 0.78 dL / g. The copolymer polyester resin described in Patent Document 2 contains 100 mol % of terephthalic acid as a dicarboxylic acid component, and 79 to 94.5 mol % of ethylene glycol, 4.0 to 31.2 mol % of neopentyl glycol, and 1.9 to 2.8 mol % of diethylene glycol as glycol components, and has an intrinsic viscosity of 0.71 dL / g to 0.75 dL / g.

[0005] JP 2011-68879 A JP 2004-123984 A

[0006] The following analysis is given in light of the present disclosure.

[0007] When resin is used as a container material, a resin is selected that corresponds to the contents and application. For example, a resin that is highly resistant to the contents (contents) is selected so that the container does not discolor or deteriorate due to contact with the contents (contents). To improve the aesthetic appeal of the container or to increase the visibility of the contents, a resin with high transparency is selected rather than an opaque resin. To improve design, a resin with high moldability is selected so that the resin can be easily molded into complex shapes.

[0008] However, generally, when an attempt is made to increase the transparency or moldability of a resin, the resistance of the resin to contents (contact materials) containing organic compounds tends to decrease. Therefore, in order to obtain a container that can accommodate desired contents and can be used for desired purposes, a resin with improved resistance to the contents, moldability, and transparency is required.

[0009] When the intrinsic viscosity is increased as in the copolymer polyester resins described in Patent Documents 1 and 2, the molding temperature, i.e., the temperature required to achieve a melt viscosity suitable for molding, becomes high. High molding temperatures make the polyester resin more susceptible to deterioration and also reduce production efficiency. Furthermore, the copolymer polyester resins described in Patent Documents 1 and 2 have a high proportion of PET structure, which makes crystalline portions prone to occur, resulting in cloudiness when thick sections are formed. Furthermore, it is difficult to improve moldability, transparency, and resistance to contact materials simply by adjusting the alcohol component, as in the copolymer polyester resins described in Patent Documents 1 and 2.

[0010] Therefore, there is a demand for a polyester resin that has high moldability, can be molded at low temperatures, has transparency in molded products, and has improved resistance to contact with objects.

[0011] There is also a demand for cosmetic containers and cosmetic products that use such polyester resins.

[0012] According to a first aspect of the present invention, there is provided a polyester resin containing a polymer of (A) an acid component and (B) an alcohol component. The component (A) contains, relative to the total amount of the component (A), 72 mol% or more of an (A1) terephthalic acid component and 8 mol% to 28 mol% of an (A2) isophthalic acid component. The component (B) contains, relative to the total amount of the component (B), 77 mol% or more of an (B1) ethylene glycol component and 4 mol% to 18 mol% of a (B2) 2,2-dimethyl-1,3-propanediol component. The sum of the content of the component (A2) relative to the component (A) and the content of the component (B2) relative to the component (B) is 24 mol% to 43 mol%. When the polyester resin contains a (B3) diethylene glycol component, the content of the (B3) diethylene glycol component is 5 mol% or less relative to the total amount of the component (B). The intrinsic viscosity is 0.48 dl / g to 0.67 dl / g.

[0013] According to a second aspect of the present invention, there is provided a cosmetic container comprising the polyester resin according to the first aspect.

[0014] According to a third aspect of the present invention, there is provided a cosmetic product including a cosmetic and the cosmetic container according to the second aspect that contains the cosmetic.

[0015] According to a fourth aspect of the present invention, there is provided a method of using a polyester resin, in which the polyester resin according to the first aspect is applied to a cosmetic container.

[0016] The polyester resin of the present disclosure has high moldability.

[0017] The polyester resins of the present disclosure are moldable at low temperatures.

[0018] The polyester resin of the present disclosure has high transparency in the form of a molded article.

[0019] The polyester resins of the present disclosure have high resistance to contact with materials.

[0020] By applying the polyester resin of the present disclosure to a cosmetic container, it is possible to provide a cosmetic container and a cosmetic product that are excellent in safety, visibility, and aesthetics.

[0021] FIG. 1 is a schematic diagram for explaining a stress crack test.

[0022] According to a preferred embodiment of the first aspect, the sum of the content of the component (A2) relative to the component (A) and the content of the component (B2) relative to the component (B) is 27 mol % to 40 mol %.

[0023] According to a preferred embodiment of the first aspect, the melt viscosity at 180° C. is 100 Pa·s to 200 Pa·s.

[0024] According to a preferred embodiment of the first aspect, the tensile elongation is 100% or more.

[0025] According to a preferred embodiment of the first aspect, the Charpy impact strength is 2 kJ / m ２ That's all.

[0026] According to a preferred mode of the first aspect, the polyester resin has a container shape.

[0027] According to a preferred embodiment of the first aspect, the polyester resin is applied to a cosmetic container.

[0028] In the following description, reference numerals in the drawings are used to facilitate understanding of the invention and are not intended to limit the invention to the illustrated embodiments. Furthermore, the shapes, dimensions, scales, etc. of the drawings are not intended to limit the invention to the forms shown in the drawings. In each embodiment, the same elements are denoted by the same reference numerals.

[0029] The polyester resin (including molded articles) of the present disclosure will be described. In this disclosure, unless otherwise specified, the polyester resin may also include molded articles. The polyester resin of the present disclosure is a polyester resin that is a copolymer of an acid component (polycarboxylic acid) and an alcohol component (polyol, polyhydroxy compound). In this disclosure, polycarboxylic acid refers to a compound having multiple carboxy groups. Furthermore, polyol or polyhydroxy compound refers to a compound having multiple hydroxy groups.

[0030] The acid component mainly contains a terephthalic acid component. The content of the terephthalic acid component is preferably 72 mol% or more, and more preferably 75 mol% or more, relative to the total amount of the acid components. The content of the terephthalic acid component can be, for example, 77 mol% or more, 80 mol% or more, 82 mol% or more, 83 mol% or more, 84 mol% or more, or 86 mol% or more, relative to the total amount of the acid components. If the terephthalic acid component is less than 72 mol%, the physical strength of the polyester resin will decrease. The content of the terephthalic acid component is preferably 92 mol% or less, more preferably 90 mol% or less, and even more preferably 88 mol% or less, relative to the total amount of the acid components. The content of the terephthalic acid component relative to the total amount of the acid components can be, for example, 86 mol% or less, 85 mol% or less, 84 mol% or less, 82 mol% or less, 80 mol% or less, 79 mol% or less, or 77 mol% or less. If the terephthalic acid component exceeds 92 mol%, the melt viscosity becomes too high.

[0031] The acid component further contains an isophthalic acid component. The content of the isophthalic acid component is preferably 8 mol% or more, more preferably 10 mol% or more, relative to the total amount of the acid components. The content of the isophthalic acid component can be, for example, 12 mol% or more, 14 mol% or more, 15 mol% or more, 16 mol% or more, 18 mol% or more, 20 mol% or more, 21 mol% or more, or 23 mol% or more, relative to the total amount of the acid components. If the isophthalic acid component is less than 8 mol%, low-temperature molding becomes difficult and the transparency of the molded body decreases. The content of the isophthalic acid component is preferably 28 mol% or less, more preferably 25 mol% or less, relative to the total amount of the acid components. The content of the isophthalic acid component relative to the total amount of the acid components can be, for example, 23 mol% or less, 20 mol% or less, 18 mol% or less, 17 mol% or less, 16 mol% or less, or 14 mol% or less. If the isophthalic acid component exceeds 28 mol%, the mechanical strength will decrease.

[0032] The total amount of the terephthalic acid component and the isophthalic acid component is preferably 90 mol % or more, more preferably 95 mol % or more, based on the total amount of the acid components. The total amount of the terephthalic acid component and the isophthalic acid component can be 100 mol % based on the total amount of the acid components.

[0033] The acid component may contain other acid components as long as the essential properties of the polyester resin of the present disclosure are not altered. Examples of other acid components include orthophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, succinic acid, dimer acid, 1,4-cyclohexadicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, trimellitic acid, and derivatives thereof. Any of these other acid components may be contained alone, or two or more may be contained in any ratio.

[0034] The alcohol component mainly contains an ethylene glycol component. The content of the ethylene glycol component is preferably 77 mol% or more, and more preferably 81 mol% or more, relative to the total amount of the alcohol components. The content of the ethylene glycol component can be, for example, 82 mol% or more, 84 mol% or more, 85 mol% or more, 86 mol% or more, 87 mol% or more, 88 mol% or more, or 90 mol% or more, relative to the total amount of the alcohol components. If the ethylene glycol component is less than 77 mol%, the resistance to contact materials will decrease. The content of the ethylene glycol component is preferably 96 mol% or less, and more preferably 92 mol% or less, relative to the total amount of the alcohol components. The content of the ethylene glycol component can be, for example, 90 mol% or less, 88 mol% or less, 86 mol% or less, or 84 mol% or less, relative to the total amount of the alcohol components. If the ethylene glycol component exceeds 96 mol%, the melt viscosity will be too high.

[0035] The alcohol component further contains a 2,2-dimethyl-1,3-propanediol component (hereinafter also referred to as a "neopentyl glycol component"). The content of the neopentyl glycol component is preferably 4 mol% or more relative to the total amount of the alcohol components. The content of the neopentyl glycol component can be, for example, 6 mol% or more, 8 mol% or more, 10 mol% or more, or 12 mol% or more relative to the total amount of the alcohol components. If the neopentyl glycol component is less than 4 mol%, the mechanical strength of the polyester resin tends to be low. The content of the neopentyl glycol component is preferably 18 mol% or less, and more preferably 16 mol% or less, relative to the total amount of the alcohol components. The content of the neopentyl glycol component can be, for example, 15 mol% or less, 14 mol% or less, 13 mol% or less, 12 mol% or less, or 10 mol% or less relative to the total amount of the alcohol components. If the neopentyl glycol component exceeds 18 mol %, the resistance of the polyester resin to substances it comes into contact with will decrease.

[0036] The total amount of the ethylene glycol component and the neopentyl glycol component is preferably 90 mol% or more, more preferably 95 mol% or more, based on the total amount of the alcohol component. The total amount of the ethylene glycol component and the neopentyl glycol component can be 100 mol% based on the total amount of the alcohol component.

[0037] The alcohol component may contain a diethylene glycol component. The diethylene glycol component may be generated as a by-product. The content of the diethylene glycol component is preferably 5 mol% or less, more preferably 4 mol% or less, more preferably 3 mol% or less, even more preferably 2 mol% or less, and even more preferably 0 mol% relative to the total amount of the alcohol component. If the diethylene glycol component exceeds 5 mol%, the resistance and heat resistance of the polyester resin to contact materials will decrease. The total of the ethylene glycol component, neopentyl glycol component, and diethylene glycol component can be 95 mol% or more, preferably 100 mol%, relative to the total amount of the alcohol component.

[0038] The alcohol component may contain other alcohol components as long as the essential properties of the polyester resin of the present disclosure are not altered. Examples of other alcohol components include 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and derivatives thereof. These other alcohol components may be contained alone, or two or more may be contained in any proportion.

[0039] The sum of the content of the isophthalic acid component based on the total amount of the acid components and the content of the neopentyl glycol component based on the total amount of the alcohol components is preferably 24 mol% or more. This sum can be, for example, 26 mol% or more, 30 mol% or more, or 35 mol% or more. If this sum is less than 24 mol%, the melt viscosity will be high and the transparency will be reduced. This sum is preferably 43 mol% or less. This sum can be, for example, 40 mol% or less, 38 mol% or less, or 35 mol% or less. If this sum exceeds 43 mol%, the resistance to contact materials will be reduced.

[0040] The intrinsic viscosity (IV value) of the polyester resin of the present disclosure is 0.48 dl / g (10 ２ cm ３ / g) or more, and more preferably 0.50 dl / g or more. The intrinsic viscosity of the polyester resin of the present disclosure can be, for example, 0.52 dl / g or more, 0.55 dl / g or more, or 0.58 dl / g or more. If the intrinsic viscosity is less than 0.48 dl / g, sufficient mechanical properties cannot be obtained. The intrinsic viscosity (IV value) of the composition of the present disclosure is preferably 0.67 dl / g or less, and more preferably 0.65 dl / g or less. The intrinsic viscosity of the polyester resin of the present disclosure can be, for example, 0.62 dl / g or less, 0.60 dl / g or less, or 0.58 dl / g or less. If the intrinsic viscosity exceeds 0.67 dl / g, the melt viscosity becomes high. If the melt viscosity is high, it is necessary to increase the heating temperature to reduce the melt viscosity. As a result, the cooling time becomes longer, productivity decreases, and the polyester resin deteriorates. On the other hand, if you try to force molding without increasing the heating temperature and while the melt viscosity is still high, the polyester resin will not flow properly into the mold, resulting in molding defects, or shear heat will occur, leading to deterioration of the polyester resin.

[0041] The above-mentioned intrinsic viscosity is the intrinsic viscosity at 20°C, measured by dissolving 0.5000±0.0005 g of a sample in a mixed solvent of phenol:tetrachloroethane = 60:40 (mass ratio) using an automatic viscosity measuring device equipped with an Ubbelohde viscometer.

[0042] The melt viscosity of the polyester resin of the present disclosure at 180 ° C. is preferably 100 Pa s or more, more preferably 110 Pa s or more. The melt viscosity of the polyester resin of the present disclosure at 180 ° C. can be, for example, 120 Pa s or more, 130 Pa s or more, or 140 Pa s or more. If the melt viscosity is less than 100 Pa s, sufficient mechanical properties cannot be obtained. The melt viscosity of the composition of the present disclosure at 180 ° C. is more preferably 200 Pa s or less, and even more preferably 190 Pa s or less. The melt viscosity of the polyester resin of the present disclosure at 180 ° C. can be, for example, 180 Pa s or less, 170 Pa s or less, or 160 Pa s or less. If the melt viscosity exceeds 200 Pa s, the same problems as when the intrinsic viscosity is high will occur.

[0043] The melt viscosity at 180°C was measured using a melt viscosity measuring device at a temperature of 180°C and a shear rate of 6080 s for 20.0±5.0 g of each dried polyester resin. －１ The method for drying the polyester resin is not particularly limited, and for example, the polyester resin can be dried using a dehumidifying dryer at 60° C. for 48 hours.

[0044] The tensile elongation of the polyester resin of the present disclosure is preferably 160% or more, and more preferably 180% or more. If the tensile elongation is less than 160%, sufficient mechanical properties cannot be obtained. The tensile elongation can be measured in accordance with ISO 527.

[0045] The Charpy impact strength of the polyester resin of the present disclosure is 2 kJ / m ２ The Charpy impact strength of the polyester resin of the present disclosure is preferably 2.1 kJ / m or more. ２ or more than 2.2 kJ / m ２ The Charpy impact strength can be 2 kJ / m or more. ２ If the Charpy impact strength is less than 100%, sufficient mechanical properties cannot be obtained. The Charpy impact strength can be measured in accordance with ISO179.

[0046] The glass transition temperature of the polyester resin according to the present disclosure is preferably 65° C. or higher, and more preferably 70° C. or higher. The glass transition temperature can be measured, for example, using a differential scanning calorimetry (DSC) device.

[0047] The polyester resin of the present disclosure preferably has no melting point peak when subjected to DSC measurement while increasing the temperature from 40° C. to 270° C. at a temperature increase rate of 10° C. / min.

[0048] The polyester resin of the present disclosure may further contain a polymerization catalyst, such as a germanium compound or a titanium compound.

[0049] The polyester resin of the present disclosure may contain known additives, such as antistatic agents, ultraviolet absorbers, heat stabilizers, release agents, antioxidants, etc., as long as the essential properties of the composition of the present disclosure are not changed.

[0050] For example, the polyester resin of the present disclosure may further contain a phosphorus compound. Examples of phosphorus compounds include phosphoric acid, phosphorous acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trimethyl phosphite, triethyl phosphite, and tributyl phosphite. Of these, trimethyl phosphate is particularly preferred. The phosphorus compound is preferably present in an amount of 5 ppm to 1000 ppm, and more preferably 20 ppm to 100 ppm, based on the mass of the polyester resin.

[0051] The polyester resin of the present disclosure may also include polyester resins obtained by the manufacturing method described below. Regarding characteristics of the polyester resin of the present disclosure other than those described above, it may be difficult or impractical to directly identify the structure, etc., by the composition. In such cases, the polyester resin of the present disclosure should be allowed to be identified by its manufacturing method.

[0052] The polyester resin of the present disclosure can be used in a wide range of molding materials, for example, containers, electric and electronic parts, and automotive materials.

[0053] The polyester resin of the present disclosure can be molded at a low temperature. For example, the molding temperature can be set to 170°C to 220°C, preferably 180°C to 200°C. This reduces the energy required for molding. In particular, the cooling time can be shortened, thereby improving production efficiency. Therefore, molding costs can be reduced.

[0054] Furthermore, by keeping the molding temperature low, it is possible to suppress the decomposition of the polyester resin in a molten state, which in turn prevents deterioration in the quality of the molded product. Furthermore, by keeping the intrinsic viscosity low, it is possible to suppress the occurrence of temperature variations due to shear heat in a molten state, which in turn allows for uniform quality of molded products.

[0055] Furthermore, by keeping the molding temperature low, the mold cooling temperature can be increased, which reduces the cost of cooling energy and also suppresses condensation on the mold.

[0056] The polyester resin of the present disclosure has high transparency even when molded. For example, clouding is suppressed even when molded into a thick-walled container. This allows molded articles of the polyester resin of the present disclosure to have a good appearance. Furthermore, the polyester resin of the present disclosure can increase the diversity of the design of molded articles.

[0057] The polyester resin of the present disclosure has high moldability. For example, the polyester resin of the present disclosure facilitates injection molding into a mold, thereby preventing short shots. As a result, the polyester resin of the present disclosure can be used to produce molded articles having complex shapes.

[0058] The polyester resin of the present disclosure has high moldability, low-temperature moldability, and transparency, while also having high resistance to contact substances such as organic compounds. For example, even when the polyester resin comes into contact with an organic compound-containing product, discoloration and deterioration of the polyester resin are suppressed. As a result, the polyester resin of the present disclosure can be used, for example, as a container for cosmetics.

[0059] The polyester resin of the present disclosure can be applied to a container body that contains cosmetics. The polyester resin of the present disclosure can also be applied to a lid that is detachably attached to the container body. The cosmetic container can contain, for example, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more of the polyester resin of the present disclosure relative to the mass of the container. The entire cosmetic container (100% by mass) can be made of the polyester resin of the present disclosure. Because the polyester resin of the present disclosure has high transparency, when a container body is made of the polyester resin of the present disclosure, the contents (cosmetics) can be seen from the outside.

[0060] The polyester resin of the present disclosure has sufficient mechanical properties.

[0061] A method for producing the polyester resin of the present disclosure will be described.

[0062] The polyester resin of the present disclosure can be produced by a known method based on the above-mentioned monomers and additives. For example, an ester prepolymer may be produced by direct esterification using an unsubstituted polycarboxylic acid as a starting material, or an ester prepolymer may be produced by transesterification using an esterified product such as dimethyl ester as a starting material. From the viewpoint of production efficiency, direct esterification is preferred.

[0063] The addition rates of the monomers and additives may be the rates set forth above in the description of the polyester resin of the present disclosure.

[0064] The direct esterification reaction or transesterification reaction can be carried out, for example, by charging raw materials into a reaction vessel equipped with a heater, a stirrer, and a distillation tube, adding a reaction catalyst, and raising the temperature while stirring under an inert gas atmosphere at atmospheric pressure, and allowing the reaction to proceed while distilling off by-products such as methanol produced by the reaction. The reaction temperature can be, for example, 150°C to 270°C, and preferably 160°C to 260°C. The reaction time is, for example, about 3 to 7 hours.

[0065] At least one metal compound can be used as a catalyst for the transesterification reaction. Preferred metal elements include, for example, sodium, potassium, calcium, titanium, lithium, magnesium, manganese, zinc, tin, and cobalt. Of these, titanium and manganese compounds are preferred because they have high reactivity and produce a good color tone for the resulting resin. The amount of transesterification catalyst added is usually preferably 5 ppm to 1000 ppm, and more preferably 10 ppm to 100 ppm, based on the polyester resin produced.

[0066] To suppress the production of diethylene glycol as a by-product, it is preferable to reduce the amount of ethylene glycol in the reaction system. For example, it is preferable to set the molar ratio of the alcohol component to the acid component (alcohol component / acid component) to 1.3 or less. Furthermore, the production of diethylene glycol can be suppressed by adding, for example, 5 ppm of sodium hydroxide.

[0067] It is also desirable to add a phosphorus compound after the completion of the direct esterification reaction or the transesterification reaction to further promote the esterification reaction. Examples of phosphorus compounds include phosphoric acid, phosphorous acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trimethyl phosphite, triethyl phosphite, and tributyl phosphite. Of these, trimethyl phosphate is particularly preferred. The amount of the phosphorus compound used is preferably 5 ppm to 1000 ppm, and more preferably 20 ppm to 100 ppm, based on the mass of the polyester resin produced.

[0068] Among the polyol components in the present disclosure, neopentyl glycol may be added during the direct esterification reaction of the polycarboxylic acid component with ethylene glycol, or may be added after the esterification reaction is completed. It is preferable to first mix the polycarboxylic acid component with ethylene glycol and neopentyl glycol at room temperature to prepare a slurry, and then proceed with the esterification reaction in an esterification reaction tank, since this can prevent neopentyl glycol from scattering. Furthermore, in the present disclosure, the entire amount of ethylene glycol may be added before the esterification reaction, and it is not necessary to add a portion of it after the esterification reaction.

[0069] Following the transesterification and esterification reactions, a polymerization catalyst can be added to the ester prepolymer, and a polycondensation reaction can be further carried out until the desired molecular weight is achieved. For example, germanium dioxide can be used as the catalyst in the polymerization reaction. The catalyst addition rate can be, for example, 180 ppm to 220 ppm relative to the amount of resin produced. The polycondensation reaction can be carried out, for example, by gradually increasing the temperature and reducing the pressure inside the reaction vessel after adding the polymerization catalyst. The pressure inside the vessel is preferably reduced to, for example, 0.4 kPa or less, preferably 0.2 kPa or less. The temperature inside the vessel is preferably increased to, for example, 250°C to 290°C. The polymerization reaction can be carried out, for example, under reduced pressure until the final vessel pressure is 150 Pa or less, until the desired melt viscosity is achieved. Thereafter, the vessel pressure can be increased to, for example, 0.5 MPa, and the reaction product can be extruded from the bottom of the vessel and recovered. For example, the reaction product can be extruded into water in the form of strands, cooled, and then cut to obtain pelletized polyester resin. In the present disclosure, the obtained pellets do not need to be subjected to an infrared irradiation step.

[0070] A catalyst other than germanium dioxide can also be used as the polymerization catalyst. For example, titanium dioxide can be used as the polymerization catalyst. When titanium dioxide is used, the catalyst addition rate can be, for example, 1 ppm to 10 ppm relative to the amount of resin produced.

[0071] The polyester resin of the present invention can be appropriately blended with various additives, such as antioxidants, heat stabilizers, lubricants, antistatic agents, plasticizers, UV absorbers, and pigments, depending on the application and molding purpose. These additives may be blended in either the polymerization reaction process or the processing / molding process. Examples of antioxidants include hindered phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants, with hindered phenol-based antioxidants being particularly preferred. The amount added is preferably approximately 100 ppm to 5000 ppm. Furthermore, when molding a melt-extrusion film, metal salts such as magnesium acetate, calcium acetate, and magnesium chloride may be added to stabilize the electrostatic adhesion of the cooling roll.

[0072] According to the method for producing a polyester resin of the present disclosure, a composition having the above-described properties can be produced.

[0073] A method for producing a molded article of the polyester resin of the present disclosure will now be described. As a method for producing a molded article of the polyester resin, for example, injection molding can be adopted.

[0074] First, the polyester resin of the present disclosure is melted. The set temperature of a heating device (e.g., a cylinder) for melting the polyester resin is a temperature that does not cause an unmelted body of the composition. The set temperature of the heating device is preferably 220°C or less, more preferably 200°C or less, and can be 180°C or less depending on the polyester resin. By lowering the heating temperature, the cooling time can be shortened, production efficiency can be improved, and quality degradation can be suppressed. The set temperature of the heating device can be 170°C or more, or 180°C or more. The polyester resin of the present disclosure has a low intrinsic viscosity, so it is possible to suppress the temperature of the polyester resin from significantly deviating from the set temperature due to shear heat. In addition, it is possible to suppress the occurrence of temperature unevenness in the melt.

[0075] Second, the molten polyester resin is filled into the mold. The mold can be maintained at a predetermined temperature. The mold temperature can be set, for example, to 20°C to 60°C, preferably 30°C to 50°C. If the mold temperature is lower than 20°C, particularly lower than room temperature, a large amount of energy is required for cooling. In addition, condensation occurs in the mold, which accelerates mold deterioration. The mold is preferably cooled with water.

[0076] Third, the polyester resin filled in the mold is molded while being held in the mold for a predetermined time. After molding, the molded body is released from the mold. The holding time from when the resin is poured into the mold to when it is released is the cooling time (molding time). The cooling time depends on the size of the molded body, particularly its thickness.

[0077] According to the method for producing a polyester resin molded article of the present disclosure, it is possible to reduce production costs by reducing energy consumption and improving production efficiency, and to produce molded articles with high and uniform quality.

[0078] The molded article of the polyester resin of the present disclosure will be described.

[0079] The polyester resin molded article of the present disclosure is a molded article produced by the above-described manufacturing method. For example, the polyester resin molded article of the present disclosure can be a molded article obtained by melting and molding a polyester resin at a set temperature of 160°C or higher, preferably 180°C or higher and 200°C or lower. The molded article of the present disclosure preferably has a portion with a thickness of 2 mm or higher, more preferably a portion with a thickness of 3 mm or higher, and even more preferably a portion with a thickness of 5 mm or higher. Having a portion with a thickness of 2 mm or higher can more effectively shorten the cooling time. For example, when the molded article has a thickness of 5 mm, it can be molded at a heating temperature of 180°C and a cooling time of about 20 seconds in a mold at 20°C to 60°C. Furthermore, the thickest portion of the molded article of the present disclosure can be 10 mm or less in thickness. When the molded article has a thickness of 10 mm, it can be molded at a heating temperature of 180°C and a cooling time of about 75 seconds in a mold at 20°C to 60°C.

[0080] The composition and properties of the molded body may change from those of the polyester resin before molding depending on the heat-melting conditions during production of the molded body. It may be difficult to directly identify the composition and properties of the molded body. In such cases, it is useful to identify the molded body based on the manufacturing method of the polyester resin before molding into the molded body.

[0081] The polyester resin molded article of the present disclosure is molded at a low temperature, allowing it to have quality with minimal deterioration from the polyester resin before molding. Furthermore, the polyester resin molded article of the present disclosure is not affected by uneven heat generation due to shear heat, allowing it to have uniform quality. The polyester resin molded article of the present disclosure can have the desired dimensions even with a short cooling time.

[0082] Molded articles of the polyester resin of the present disclosure can be designed in a variety of designs. For example, the molded articles can be designed into containers with thick, transparent bottoms. Such containers can have a luxurious feel. Furthermore, the molded articles can be designed into containers with complex shapes.

[0083] A molded article of the polyester resin of the present disclosure has moldability, low-temperature moldability, and transparency, yet has high resistance to contact with substances (e.g., organic compounds) with reduced discoloration and deformation.

[0084] According to the present disclosure, the polyester resin of the present disclosure can be molded into a cosmetic container for containing a cosmetic.

[0085] The cosmetic container and cosmetic product of the present disclosure will be described.

[0086] The cosmetic product of the present disclosure includes a cosmetic and a cosmetic container for containing the cosmetic. The cosmetic container, particularly the main body for containing the cosmetic, is a cosmetic container containing the polyester resin of the present disclosure. Preferably, the cosmetic container, particularly the main body for containing the cosmetic, is a molded article made of the polyester resin of the present disclosure.

[0087] The cosmetic may be in any form, such as an aqueous composition, an oil-based composition, an emulsion composition (such as an oil-in-water composition or a water-in-oil composition), etc. Examples of the cosmetic include sunscreen cosmetics, lotions, foundations, lipsticks, moisturizers, nail polish, mascara, and hair cosmetics.

[0088] By applying the polyester resin of the present disclosure to a cosmetic container, it is possible to provide a cosmetic container and a cosmetic product that are excellent in safety, visibility, and aesthetics.

[0089] In this disclosure, the term "or greater than" may be read as "greater than," where appropriate. Additionally, the term "or less than" may be read as "less than," where appropriate.

[0090] The polyester resin (including molded articles), its use, and the cosmetic container and cosmetic product of the present disclosure will be described below using examples. The polyester resin, its use, and the cosmetic container and cosmetic product of the present disclosure are not limited to the following examples.

[0091] [Test Examples 1 to 15] Polyester resins were prepared, and the intrinsic viscosity, melt viscosity, glass transition temperature, content resistance, and mechanical properties of each polyester resin were tested. Tables 1 and 2 show the compositions and measurement results of Test Examples 1 to 15.

[0092] [Preparation of Polyester Resin] Terephthalic acid (TPA), isophthalic acid (IPA), ethylene glycol (EG), and 2,2-dimethyl-1,3-propanediol (neopentyl glycol (NPG)) were placed in a 30 L autoclave in the compositional proportions shown in Tables 1 and 2, and an esterification reaction was carried out at 250°C under nitrogen flow and atmospheric pressure. The blending proportions shown in Tables 1 and 2 indicate the blending proportions of the acid component and the alcohol component, respectively. Subsequently, using germanium dioxide as a polymerization catalyst, the pressure inside the reaction vessel was reduced over one hour, and a polycondensation reaction was carried out at 270°C under a reduced pressure of 100 Pa or less until a predetermined viscosity was reached. The reaction product was extruded from the reaction vessel into water and cut using a pelletizer to obtain resin pellets. The produced polyester resin was subjected to the following measurements.

[0093] In Test Example 15, the raw material ratio G / A of the alcohol (G) and the acid (A) was set to 1.6, thereby producing a larger amount of diethylene glycol.

[0094] [Measurement of Intrinsic Viscosity] For each polyester resin, 0.5000 g±0.0005 g of a sample was dissolved in a mixed solvent of phenol:tetrachloroethane = 60:40 (mass ratio), and the intrinsic viscosity at 20°C was measured using an automatic viscosity measuring device (ALC-6C manufactured by Sun Electronics Industries Co., Ltd.) equipped with an Ubbelohde viscometer.

[0095] [Measurement of Melt Viscosity] The polyester resin samples were dried using a dehumidifying dryer at 60° C. for 48 hours. Then, 20.0 g±5.0 g of each dried polyester resin was weighed out and measured using a melt viscosity measuring device at a measurement temperature of 180° C. and a shear rate of 6080 s －１ When the resin temperature in the furnace of the melt viscosity measuring device rose above the measurement temperature, it was judged that the melt viscosity measurement was impossible.

[0096] [Glass Transition Temperature] Using a differential scanning calorimeter (DSC-7 manufactured by PerkinElmer), the endothermic behavior of a polyester resin sample was observed while the temperature was raised from 30°C at a rate of 2°C / min in a nitrogen atmosphere, and the midpoint temperature of the endothermic behavior due to glass transition was taken as the glass transition temperature (Tg).

[0097] [Presence or absence of whitening during molding] The polyester resin of each test example was molded into a 9 mm thick plate at a molding temperature of 180°C and a cooling temperature of 40°C, and the molded product was checked for whitening. However, the polyester resins of test examples 9 and 12, which cannot be molded at 180°C, were molded at 220°C. No: No whitening occurred in the molded product; Yes: Whitening occurred in the molded product.

[0098] [Content Resistance Test] Assuming that the polyester resin would be used in a container, the resistance of the resin to the contents was tested. Specifically, the stress crack test and appearance change test described below were conducted. The test specimens were made by molding the polyester resin into plates measuring 80 mm in length, 10 mm in width, and 2 mm in thickness. Assuming that the contents were topical skin preparations, commercially available sunscreen cosmetics (cream and gel) and beauty serum (cream) were used as test agents applied to the test specimens. [Stress Crack Test] Figure 1 shows the apparatus used for the stress crack test. Approximately half of the longitudinal length of the test specimen 1 was protruded from the base 3 to serve as a fulcrum 1b. One end of the test specimen 1 was fixed to the base 3 with a fixture 4. A 200 g weight 2 was hung from the other end of the test specimen 1, so that a load of approximately 6.9 N·cm was applied to the fulcrum 1b. The test agent was applied to the upper surface of the area including the fulcrum 1b (application area 1a), and the test piece was left to stand for 24 hours at 23°C and a relative humidity of 50% RH. After 24 hours, it was confirmed whether cracks had occurred in the test piece 1. The evaluation criteria are as follows: A: No cracks occurred in the test piece; B: Fine cracks occurred in the test piece; C: Large cracks occurred in the test piece; D: The test piece was broken.

[0099] [Appearance Change Test] A test agent was applied to one side of a test piece. With the test agent applied, the test piece was left to stand for 7 days in an environment of 23°C or 37°C and a relative humidity of 50% RH. After 7 days, the appearance of the test piece was checked. A: No change in the appearance of the test piece; B: The test piece was slightly whitened; C: The test piece was whitened or the surface of the test piece was roughened.

[0100] [Measurement of Mechanical Properties] The tensile elongation of each polyester resin was measured in accordance with ISO 527. The tensile elongation was measured for five samples, and the average value was calculated. In addition, the Charpy impact strength of each polyester resin was measured in accordance with ISO 179. The Charpy impact strength was measured for 10 samples, and the average value was calculated.

[0101] In Test Examples 1 to 8, good evaluations were obtained for all evaluation items.

[0102] It was found that the containers produced in Test Examples 1 to 8 were applicable as cosmetic containers.

[0103] On the other hand, Test Examples 10 to 12, in which the neopentyl glycol content was 20 mol % or more, received low evaluations in the stress crack test. From this, it is considered that the content of neopentyl glycol is preferably 18 mol % or less, and more preferably 16 mol % or less, relative to the total amount of alcohol components.

[0104] In addition, in Test Example 12, which did not contain isophthalic acid, the intrinsic viscosity increased and the melt viscosity became so high that it was impossible to measure. Furthermore, whitening occurred during container molding. Therefore, it is considered preferable that the content of isophthalic acid is 8 mol% or more relative to the total amount of acid components.

[0105] In Test Example 14, in which the isophthalic acid content was 30 mol %, sufficient mechanical strength was not obtained. From this, it is considered that the content of isophthalic acid is preferably 28 mol % or less relative to the total amount of acid components.

[0106] In Test Example 15, which contained 7 mol % diethylene glycol, the evaluation in the stress crack test was low, and the evaluation in the appearance change test at 37° C. was also low. From this, it is considered preferable that the content of diethylene glycol is 5 mol % or less relative to the total amount of alcohol components.

[0107] In Test Example 13, in which the total content of isophthalic acid and neopentyl glycol was high, the evaluation of the appearance change test, particularly the resistance to contents at high temperatures, was low. Therefore, it is considered preferable that the total content be 43 mol% or less.

[0108] In Test Example 9, in which the total content of isophthalic acid and neopentyl glycol was low, the melt viscosity was so high that it could not be measured. In Test Example 12, the transparency of the molded article was low. Therefore, it is considered preferable that the total content be 24 mol% or more.

[0109]

[0110]

[0111] The polyester resin (including molded articles), its manufacturing method, its use, and the cosmetic container and cosmetic product of the present invention have been described based on the above embodiments and examples, but are not limited to the above embodiments and examples and can include various modifications, changes, and improvements to each disclosed element (including elements described in the claims, specification, and drawings) within the scope of the present invention and based on the basic technical idea of ​​the present invention. Furthermore, various combinations, substitutions, and selections of each disclosed element are possible within the scope of the claims of the present invention.

[0112] Further objects, purposes and modes (including modifications) of the present invention will become apparent from the entire disclosure of the present invention including the claims.

[0113] With respect to numerical ranges set forth herein, unless otherwise specified, any numerical value or range falling within that range should be construed as being specifically set forth herein.

[0114] The polyester resin of the present disclosure has excellent moldability and mechanical properties, and therefore the polyester resin and molded articles thereof can be used in a wide range of molding materials, such as containers, electric and electronic parts, and automotive materials.

[0115] 1 Test piece 1a Coating area 1b Support 2 Weight 3 Base 4 Fixture

Claims

1. A polyester resin comprising a polymer of (A) an acid component and (B) an alcohol component, The component (A) contains, relative to the total amount of the component (A), 72 mol % or more of an (A1) terephthalic acid component and 8 mol % to 28 mol % of an (A2) isophthalic acid component, The component (B) contains, relative to the total amount of the component (B), 77 mol % or more of an ethylene glycol component (B1) and 4 mol % to 18 mol % of a 2,2-dimethyl-1,3-propanediol component (B2); the sum of the content of the (A2) component relative to the (A) component and the content of the (B2) component relative to the (B) component is 24 mol % to 43 mol %, The content of the diethylene glycol component (B3) is 5 mol % or less based on the total amount of the component (B), A polyester resin having an intrinsic viscosity of 0.48 dl / g to 0.67 dl / g.

2. The polyester resin described in claim 1, wherein the (A) component contains, relative to the total amount of the (A) component, 75 mol% to 88 mol% of an (A1) terephthalic acid component and 12 mol% to 25 mol% of an (A2) isophthalic acid component.

3. The polyester resin described in claim 1, wherein the (B) component contains, relative to the total amount of the (B) component, 81 mol% to 91 mol% of an (B1) ethylene glycol component and 6 mol% to 16 mol% of a (B2) 2,2-dimethyl-1,3-propanediol component.

4. The polyester resin according to claim 1, wherein the total is from 27 mol% to 40 mol%.

5. The polyester resin according to claim 1, having a melt viscosity at 180°C of 100 Pa·s to 200 Pa·s.

6. The polyester resin according to claim 1, having a tensile elongation of 100% or more.

7. Charpy impact strength is 2 kJ / m ２ The polyester resin according to claim 1 .

8. The polyester resin according to any one of claims 1 to 7, which has a container shape.

9. A molded body comprising the polyester resin according to any one of claims 1 to 7, A molded article having a container shape, which has a part having a thickness of 2 mm or more and the thickest part is 10 mm or less.

10. A molded body as described in claim 9, having a cosmetic container shape.

11. A cosmetic container comprising the polyester resin according to any one of claims 1 to 7.

12. Cosmetics and A cosmetic product comprising: the cosmetic container according to claim 11 that contains the cosmetic.

13. A method for using the polyester resin according to any one of claims 1 to 7, which is applied to a cosmetic container.