Polyester resin and its manufacturing method, molded article, fiber, fiber for tires, and reaction method.

Abstract

The present invention provides a polyester resin with improved reactivity in electron beam crosslinking, a method for producing the same, a molded article containing the polyester resin, a fiber containing the polyester resin, a fiber for tires containing the fiber, and a reaction method using the polyester resin. [Solution] A polyester resin having structural units derived from a dicarboxylic acid compound and structural units derived from an unsaturated diol compound, wherein the structural units derived from the unsaturated diol compound include a linear portion, two oxygen atoms derived from hydroxyl groups bonded to both ends of the linear portion, and a side chain portion branching from the linear portion and having one or more ethylenic carbon-carbon double bonds.

Description

Technical Field

[0001] The present invention relates to a polyester resin, a method for producing the same, a molded body, a fiber, a fiber for a tire, and a reaction method. In particular, the present invention relates to a polyester resin having improved reactivity in electron beam crosslinking, a method for producing the same, a molded body containing the polyester resin, a fiber containing the polyester resin, a fiber for a tire containing the fiber, and a reaction method using the polyester resin.

Background Art

[0002] Conventionally, an adhesive treatment called resorcinol / formalin / latex treatment (RFL treatment) has been performed on an unmodified polyester resin such as polyethylene terephthalate (PET) to impart rubber adhesiveness. However, since the RFL treatment involves a treatment containing formalin or the like, there are concerns about adverse effects on the environment and health. Furthermore, since a two-step process is required, there are concerns about cost increases. Therefore, it has been studied to impart rubber adhesiveness by olefin-modifying a polyester resin without performing the RFL treatment.

[0003] For example, a semi-aromatic polyester copolymer using a 1,2-disubstituted olefin such as cis-2-butene-1,3-diol (CBD) as a modifier, which is crosslinked by heating in the presence of a radical initiator to obtain a high-strength and high-modulus semi-aromatic polyester copolymer, is disclosed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the technology described in Patent Document 1 had the problem of low reactivity in electron beam crosslinking, making it impossible to impart rubber adhesion.

[0006] The object of the present invention is to provide a polyester resin with improved reactivity in electron beam crosslinking, a method for producing the same, a molded article containing the polyester resin, a fiber containing the polyester resin, a fiber for tires containing the fiber, and a reaction method using the polyester resin. [Means for solving the problem]

[0007] As a result of diligent research, the inventors of the present invention have found that the reactivity in electron beam crosslinking is improved when the polyester resin has (A) a structural unit derived from a dicarboxylic acid compound and (B) a structural unit derived from an unsaturated diol compound containing a linear portion, two oxygen atoms derived from hydroxyl groups bonded to both ends of the linear portion, and a side chain portion branching from the linear portion and having one or more ethylenic carbon-carbon double bonds, and have completed the present invention. The above is based on the fact that the reactivity in electron beam crosslinking is higher when the unsaturated diol compound is a monosubstituted olefin and / or a 1,1-disubstituted olefin than when the unsaturated diol compound is a 1,2-disubstituted olefin. However, when the unsaturated diol compound is a monosubstituted olefin, there is a risk that it will react at the polycondensation temperature and gel during polymerization. In this respect, when the unsaturated diol compound is a 1,1-disubstituted olefin, a balance is struck between the stability during polycondensation and the reactivity of the introduced olefin, making it more preferable.

[0008] In other words, the present invention is as follows [1] to

[13] . [1] A polyester resin having structural units derived from a dicarboxylic acid compound and structural units derived from an unsaturated diol compound, wherein the structural units derived from the unsaturated diol compound include a linear portion, two oxygen atoms derived from hydroxyl groups bonded to both ends of the linear portion, and a side chain portion branching from the linear portion and having one or more ethylenic carbon-carbon double bonds. [2] The polyester resin according to [1] above, wherein the ethylenic carbon-carbon double bond is a carbon-carbon double bond containing a methylidene group. [3] The polyester resin according to [1] or [2] above, wherein the structural units derived from the dicarboxylic acid compound are structural units derived from an aromatic dicarboxylic acid compound. [4] The polyester resin according to any one of [1] to [3] above, wherein the structural unit derived from the unsaturated diol compound is a structural unit derived from an unsaturated diol compound with a 1,1-disubstituted olefin structure. [5] The polyester resin according to [4] above, wherein the structural unit derived from the unsaturated diol compound is a structural unit derived from 2-methylene-1,3-propanediol. [6] The polyester resin according to any one of [1] to [5] above, wherein the content of structural units derived from the unsaturated diol compound is 0.1 to 30 mol% based on 100 mol% of the total amount of all structural units in the polyester resin. [7] A polyester resin according to any of [1] to [6] above, having a number average molecular weight of 3000 or more and a molecular weight distribution of 5 or less. [8] A method for producing a polyester resin according to any of [1] to [7] above, comprising a polycondensation step of polycondensing the dicarboxylic acid compound, the unsaturated diol compound containing an ethylenic carbon-carbon double bond, and the saturated diol compound. [9] The method for producing a polyester resin according to [8] above, wherein the polycondensation temperature in the polycondensation step is 250°C or less.

[10] A molded article containing the polyester resin described in any of [1] to [7] above.

[11] A fiber containing the polyester resin described in any of [1] to [7] above.

[12] Tire fibers containing the fibers described in

[11] above.

[13] A reaction method comprising a post-reaction step in which an ethylenically charged carbon-carbon double bond contained in the polyester resin described in any of [1] to [7] above is used as a reaction site for a post-reaction, wherein the post-reaction in the post-reaction step is one or more selected from the group consisting of a thermal radical reaction, a UV radical reaction, a redox radical reaction, an electron beam-triggered reaction, an enthiol reaction, a vulcanization reaction, a Diels-Alder reaction, a hydrosilylation reaction, a hydroboration reaction, an epoxidation reaction, a cyclization reaction, and a diolation reaction. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a polyester resin with improved reactivity in electron beam crosslinking, a method for producing the same, a molded article containing the polyester resin, a fiber containing the polyester resin, a fiber for tires containing the fiber, and a reaction method using the polyester resin. Normally, polyester resins such as polyethylene terephthalate (PET) have an inert structure, making it difficult to functionalize them through post-reactions. However, the polyester resin of the present invention can be given post-reactivity by using the introduced olefin functional group (ethylenically active carbon-carbon double bond) as a reaction site. [Modes for carrying out the invention]

[0010] The following description is based on an example of an embodiment of the present invention. However, the embodiments shown below are illustrative examples for realizing the technical concept of the present invention, and the present invention is not limited to the following description. In this specification, although preferred forms of the embodiments are shown, combinations of two or more of the individual preferred forms are also preferred forms. For matters indicated by numerical ranges, when there are several numerical ranges, the lower limit values and upper limit values thereof can be selectively combined to form preferred forms. For example, from the description "preferably 10 to 90, more preferably 30 to 60", it is also possible to combine the "preferred lower limit value (10)" and the "more preferred upper limit value (60)" to obtain "10 to 60". Also, within the numerical ranges described in this specification, the upper limit value or lower limit value of the numerical range may be replaced with the values shown in the examples. In this specification, when there is a description of a numerical range of "XX to YY", it means "XX or more and YY or less". In this specification, the "structural unit" means the "repeating unit constituting the polymer".

[0011] [Polyester resin] The polyester resin of the present invention has a structural unit derived from a dicarboxylic acid compound and a structural unit derived from an unsaturated diol compound, and optionally has other structural units. Note that the polyester resin of the present invention does not contain (1) the "structural unit represented by the general formula (refer to the following general formula (1)) in claim 1 of JP-A-4-15210" which contains an ethylenic carbon-carbon double bond only in the linear portion and (2) the "structural unit derived from an unsaturated diol compound having a 1,2-disubstituted olefin structure such as cis-2-butene-1,4-diol (CBD)" which contains an ethylenic carbon-carbon double bond only in the linear portion.

[0012] [Chemical formula] ··· General formula (1) (In general formula (1), R 1 and R 2 are each a hydrogen atom, a halogen atom, or an alkyl group having 1 to 8 carbon atoms, and m and n are each an integer of 1 to 10.)

[0013] <Structural unit derived from dicarboxylic acid compound> The structural unit derived from a dicarboxylic acid compound is not particularly limited, and examples thereof include a structural unit derived from an aliphatic dicarboxylic acid, a structural unit derived from an alicyclic dicarboxylic acid, a structural unit derived from an aromatic dicarboxylic acid compound, and the like. These may be used alone or in combination of two or more. Among these, from the viewpoints of hardness and heat resistance, a structural unit derived from an aromatic dicarboxylic acid compound is preferable.

[0014] (Aliphatic dicarboxylic acid) The aliphatic dicarboxylic acid is not particularly limited, and examples thereof include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and the like. These may be used alone or in combination of two or more. Among these, from the viewpoint of the balance between strength and flexibility, succinic acid and adipic acid are preferable.

[0015] ( Alicyclic dicarboxylic acid) The alicyclic dicarboxylic acid is not particularly limited, and examples thereof include cyclohexanedicarboxylic acid, furandicarboxylic acid, pyrandicarboxylic acid, adamantanedicarboxylic acid, dihydrofurandicarboxylic acid, trihydropyrandicarboxylic acid, cyclopropanedicarboxylic acid, cyclobutanedicarboxylic acid, camphoric acid, and the like. These may be used alone or in combination of two or more. Among these, from the viewpoint of availability, cyclohexanedicarboxylic acid is preferable.

[0016] (Aromatic dicarboxylic acid) The aromatic dicarboxylic acid is not particularly limited, and examples thereof include phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and the like. These may be used alone or in combination of two or more. Among these, from the viewpoints of strength, heat resistance, and availability, terephthalic acid is preferable.

[0017] Dicarboxylic acid compounds include not only dicarboxylic acids having two carboxyl groups, but also compounds derived from dicarboxylic acids (compounds in which the carboxyl groups have been modified). There are no particular restrictions on the dicarboxylic acid-derived compounds (compounds in which the carboxyl group has been modified), and examples include diester compounds such as bis(2-hydroxyethyl) terephthalate (BHET: see structural formula 1 below); dicarboxylic acid halide compounds such as terephthalic acid chloride; and so on.

[0018] [ka] ...Structural formula 1

[0019] There are no particular restrictions on the content of structural units derived from dicarboxylic acid compounds, but it is preferably 30 to 70 mol%, more preferably 40 to 60 mol%, and most preferably 45 to 55 mol%, relative to 100 mol% of the total amount of structural units in the polyester resin. If the value is above the lower limit of the above range, strength and heat resistance can be increased, and if it is below the upper limit of the above range, a moderate degree of flexibility can be provided.

[0020] <Structural units derived from unsaturated diol compounds> The structural unit derived from the unsaturated diol compound contains a linear portion, two oxygen atoms derived from hydroxyl groups bonded to both ends of the linear portion, and a side chain portion that branches off from the linear portion and has one or more ethylenic carbon-carbon double bonds. The linear portion is the part formed between the oxygen atoms derived from the two hydroxyl groups in the unsaturated diol compound, and does not contain the oxygen atoms derived from the two hydroxyl groups. The side chain portion is preferably branched from an atom other than the atom to which the two hydroxyl groups of the linear portion are bonded (e.g., a carbon atom), such as a structural unit derived from 2-methylene-1,3-propanediol (MPDA: see structural formula 2 below) or a structural unit derived from 2-isopropenyl-1,3-propanediol (IPED: see structural formula 3 below). There are no particular restrictions on the position of the ethylenic carbon-carbon double bond, but it is preferable that it be located at the end of the side chain, for example, in structural units derived from 2-methylene-1,3-propanediol (MPDA), 2-isopropenyl-1,3-propanediol (IPED), and 3,4-dihydroxy-1-butene (DOB: see structural formula 4 below).

[0021] [ka] ...Structural formula 2

[0022] [ka] ...Structural formula 3

[0023] [ka] ...Structural formula 4

[0024] There are no particular restrictions on the ethylenic carbon-carbon double bond; for example, carbon-carbon double bonds containing alkylidene groups such as methylidene, ethylidene, and propyridene; and carbon-carbon double bonds containing alkenylene groups such as propenylene. These may be used individually or in combination of two or more. Among these, a carbon-carbon double bond containing a methylidene group is more preferable from the viewpoint of imparting high post-reactivity.

[0025] There are no particular restrictions on the structural units derived from unsaturated diol compounds. Examples include structural units derived from unsaturated diol compounds with 1,1-disubstituted olefin structures such as 2-methylene-1,3-propanediol (MPDA), 2-isopropenyl-1,3-propanediol (IPED), and 3-methylene-1,5-propanediol; and monosubstituted olefin structures such as 3,4-dihydroxy-1-butene (DOB), glycerol monoallyl ether, glycerol monovinyl ether, trimethylolpropane monoallyl ether, trimethylolpropane monovinyl ether, 3-allyloxy-1,2-propanediol, pentaerythritol diallyl ether, pentaerythritol divinyl ether, and pentaerythritol allyl vinyl ether. These may be used individually or in combination of two or more. Among these, structural units derived from unsaturated diol compounds with a 1,1-disubstituted olefin structure are preferred, and structural units derived from 2-methylene-1,3-propanediol (MPDA) are more preferred, from the viewpoint of achieving both stability during polycondensation and post-reactivity.

[0026] There are no particular restrictions on the content of structural units derived from unsaturated diol compounds, but it is preferably 0.1 to 30 mol%, more preferably 0.2 to 20 mol%, and especially preferably 0.3 to 10 mol%, relative to 100 mol% of the total amount of structural units in the polyester resin. If the value is above the lower limit of the above range, high post-reactivity can be imparted, and if it is below the upper limit of the above range, the risk of high molecular weight formation during polymerization can be reduced and stringiness can be improved.

[0027] <Total content of structural units derived from dicarboxylic acid compounds and structural units derived from unsaturated diol compounds> There are no particular restrictions on the total content of structural units derived from dicarboxylic acid compounds and structural units derived from unsaturated diol compounds, but it is preferably 70 to 100 mol%, more preferably 80 to 100 mol%, and particularly preferably 90 to 100 mol%, relative to 100 mol% of the total amount of structural units in the polyester resin. If the value is above the lower limit of the above range, a high molecular weight resin is obtained.

[0028] <Other structural units> Other structural units are not particularly limited, but are preferably derived from saturated diol compounds such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, cyclohexanediol, cyclohexanedimethanol, cyclooctanediol, adamantanediol, and bicyclohexanol; or aromatic diol compounds such as benzenedimethanol. These may be used individually or in combination of two or more. Among these, structural units derived from ethylene glycol are preferred from the standpoint of industrial availability.

[0029] There are no particular restrictions on the total content of other structural units, but it is preferably 0 to 10 mol%, more preferably 0 to 5 mol%, and especially preferably 0 to 3 mol%, relative to 100 mol% of the total amount of all structural units in the polyester resin. If the value is above the lower limit of the above range, the strength and flexibility can be adjusted, and if it is below the upper limit of the above range, the strength can be increased.

[0030] <Physical properties of polyester resin> The physical properties of the polyester resin of the present invention, including the number-average molecular weight (Mn), weight-average molecular weight (Mw), molecular weight distribution (Mw / Mn), electron beam crosslinking properties, and stringiness, are described below.

[0031] (Number average molecular weight (Mn)) The number average molecular weight of the polyester resin of the present invention is not particularly limited, but is preferably 2000 to 200000, more preferably 2200 to 100000, even more preferably 2500 to 50000, particularly preferably 3000 to 30000, and most preferably 4000 to 10000. If the value is above the lower limit of the above range, the strength of the polyester resin can be increased, and if it is below the upper limit of the above range, stability during polymerization can be ensured. In this specification, the Mn of the polyester resin is the number-average molecular weight on a standard polymethyl methacrylate (PMMA) basis, determined by size exclusion high-performance liquid chromatography, and is measured in detail by the method described in the examples.

[0032] (Weight average molecular weight (Mw)) The weight-average molecular weight of the polyester resin of the present invention is not particularly limited, but is preferably 2,000 to 600,000, more preferably 3,000 to 300,000, even more preferably 5,000 to 100,000, particularly preferably 10,000 to 50,000, and most preferably 20,000 to 30,000. If the value is above the lower limit of the above range, the strength of the polyester resin can be increased, and if it is below the upper limit of the above range, stability during polymerization can be ensured. In this specification, the Mw of the polyester resin is the weight-average molecular weight on a standard polymethyl methacrylate (PMMA) basis, determined by size exclusion high-performance liquid chromatography, and is measured in detail by the method described in the examples.

[0033] (Molecular weight distribution (Mw / Mn)) The molecular weight distribution (Mw / Mn) of the polyester resin of the present invention is not particularly limited, but is preferably 5 or less, more preferably 1.5 to 4.5, and particularly preferably 2.0 to 4.0. If the value is above the lower limit of the above range, synthesis can be facilitated, and if it is below the upper limit of the above range, the stringiness can be improved. In this specification, the molecular weight distribution (Mw / Mn) is the molecular weight distribution (Mw / Mn) calculated from the weight-average molecular weight (Mw) and number-average molecular weight (Mn) in terms of standard polymethyl methacrylate resin (PMMA) obtained by size exclusion high-performance liquid chromatography (HCM), and is measured in detail by the method described in the examples.

[0034] (Electron beam crosslinkability) From the viewpoint of improving physical properties through crosslinking, it is desirable for polyester resins to have as high electron beam crosslinkability as possible. More specifically, it is preferable that a film approximately 100 μm thick obtained by hot pressing a modified polyester resin is sealed in a nitrogen atmosphere, subjected to 500 kGy electron beam irradiation, immersed in a large amount of hexafluoro-2-propanol (HFIP) solution, and heated in a water bath at 50°C for 1 hour, resulting in gelation. Electron beam crosslinking properties are measured by the method described in the examples.

[0035] (Stringy) From the viewpoint of processing polyester resin into a fibrous form for use, it is desirable that the polyester resin has as high a stringing property as possible. More specifically, it is preferable that the modified polyester resin is set in a flow tester, melted at polymerization temperature + 10 degrees Celsius for 5 minutes, and then extruded, and that the extruded molten resin exhibits stringing. The stringiness is measured by the method described in the examples.

[0036] [Method for manufacturing polyester resin] The present invention relates to a method for producing a polyester resin, comprising a polycondensation step and, if necessary, further comprising other steps.

[0037] <Polycondensation process> The polycondensation step involves polycondensing the aforementioned dicarboxylic acid compound with the aforementioned unsaturated diol compound containing an ethylenic carbon-carbon double bond and the aforementioned saturated diol compound.

[0038] There are no particular restrictions on the polycondensation temperature in the polycondensation process, but it is preferably 250°C or lower, more preferably 150 to 250°C, and most preferably 200 to 250°C. If the value is above the lower limit of the above range, the molecular weight of the polyester resin can be increased in a shorter time, and if it is below the upper limit of the above range, the stringiness can be improved.

[0039] There are no particular restrictions on the polycondensation catalyst used in polyester production. Examples include titanium(IV) alkoxides such as tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, and tetrabutoxytitanium; tin compounds such as di-n-butyltin oxide, di-n-butyltin dilaurate, and dibutyltin diacetate; and combinations of acetates of magnesium, calcium, zinc, etc., with antimony oxide or the above-mentioned titanium compounds. These may be used individually or in combination of two or more. Among these, tetrabutoxytitanium as titanium(IV) alkoxide is preferred from the standpoint of high catalytic performance.

[0040] There are no particular restrictions on the amount of polycondensation catalyst used, but it is preferably 5 to 500 ppm by mass, more preferably 30 to 300 ppm by mass, and most preferably 50 to 200 ppm by mass relative to the polyester resin produced. If the value is above the lower limit of the above range, sufficient catalytic performance for the polycondensation reaction can be expected. If the value is below the upper limit of the above range, the need for catalyst removal by washing is eliminated, and a reduction in the number of steps can be expected.

[0041] The ratio MA:MB of the molar amount MA of the dicarboxylic acid compound to the molar amount MB of the unsaturated diol compound used in the above polycondensation reaction is not particularly limited, but is preferably 0.8:1.0~1.0:0.8, more preferably 0.9:1.0~1.0:0.9, and especially preferably 0.95:1.0~1.0:0.95. If the value is above the lower limit of the above range, a reduction in the amount of unreacted monomer can be expected, and if the value is below the upper limit of the above range, a reduction in the amount of unreacted monomer can be expected. Furthermore, if the dicarboxylic acid compound and the unsaturated diol compound each consist of multiple types of compounds, the above molar amounts are the arithmetic mean of the molar amounts of those multiple compounds.

[0042] <Polyester resin composition> The polyester resin composition comprises the polyester resin of the present invention and may further contain other resins and additives as needed. There are no particular restrictions on the polyester resin content in the polyester resin composition, but from the viewpoint of making it easier for the polyester resin composition to exhibit the desired performance, the content is preferably 50 to 100% by mass, more preferably 60 to 95% by mass, and particularly preferably 70 to 90% by mass, when the polyester resin composition is considered to be 100% by mass.

[0043] (Other resins) Other resins besides polyester resins are not particularly limited, but examples include polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polyglycolic acid (PGA), polyethylene furanoate (PEF), polyhydroxyalkanoate (PHA) [e.g., polyhydroxybutyrate valiate (PHBV), 3-hydroxybutyrate-3-hydroxyhexanoic acid copolymer polyester, etc.], cellulose acetate (CA), starch, 3-hydroxybutanoic acid polymers, β-methyl-δ-valerolactone polymers, and other biomass resins or biodegradable resins. These may be used individually or in combination of two or more.

[0044] There are no particular restrictions on the content of other resins, but from the viewpoint of effectively obtaining the effects of the present invention, it is preferably less than 50 parts by mass, more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less, relative to 100 parts by mass of the total of polyester resin and other resins. There are no particular restrictions on the lower limit, but for example, it is 5 parts by mass or more. In other words, the content of other resins is preferably 5 parts by mass or more and less than 50 parts by mass, relative to 100 parts by mass of the total of polyester resin and other resins.

[0045] (Additives) There are no particular restrictions on the additives, and examples include inorganic fillers, softeners, heat aging inhibitors, antioxidants, light stabilizers, antistatic agents, mold release agents, flame retardants, foaming agents, pigments, dyes, whitening agents, UV absorbers, lubricants, plasticizers, crosslinking agents, fillers, crosslinking accelerators, crosslinking aids, tackifiers, adhesion enhancers, organic fillers, nucleating agents, heat-resistant stabilizers, colorants, flame retardant aids, blooming inhibitors, thickeners, conductive aids, flowability enhancers, hydrolysis resistant agents, etc. These may be used individually or in combination of two or more. There are no particular restrictions on the content of additives, but from the viewpoint of making it easier for the polyester resin composition to exhibit the desired performance, the additive content is preferably 0.001 to 30% by mass, more preferably 0.005 to 25% by mass, even more preferably 0.007 to 20% by mass, even more preferably 0.01 to 15% by mass, even more preferably 0.01 to 10% by mass, and particularly preferably 0.01 to 5% by mass, when the polyester resin composition is considered as 100% by mass.

[0046] (Method for producing polyester resin composition) There are no particular restrictions on the method for producing the polyester resin composition; it is sufficient to uniformly mix the polyester resin, any other resin, and any additives. There are no particular restrictions on the mixing method, and examples include melt-kneading using a single-screw extruder, multi-screw extruder, Banbury mixer, heated roll, brabender, various kneaders, etc. Here, each component may be supplied from separate input ports. Furthermore, the ingredients may be pre-blended before melting and mixing. There are no particular restrictions on the method of pre-blending; for example, mixing machines such as Henschel mixers, high-speed mixers, V-blenders, ribbon blenders, tumbler blenders, and conical blenders can be used. There are no particular restrictions on the temperature during melt mixing, but from the viewpoint of the melting point and decomposition temperature of the polyester resin, it is preferably 130 to 200°C.

[0047] [Reaction method] The reaction method of the present invention includes a post-reaction step and, if necessary, further includes other steps.

[0048] <Post-reaction steps> The post-reaction step is a step in which the ethylenic carbon-carbon double bonds contained in the polyester resin of the present invention are used as reaction sites for a post-reaction. Post-reaction steps include thermal radical reactions, UV radical reactions, redox radical reactions, electron beam-triggered reactions, enthiol reactions, vulcanization reactions, Diels-Alder reactions, hydrosilylation reactions, hydroboration reactions, epoxidation reactions, cyclization reactions, and diolation reactions. These may be used individually or in combination of two or more. Among these, thermal radical reactions, UV radical reactions, redox radical reactions, electron beam-triggered reactions, enthiol reactions, and vulcanization reactions are preferred from the standpoint of increasing the reaction rate.

[0049] <<Enthiol reaction>> For the enthiol reaction, if a mercapto group-containing compound is used that further contains hydrophilic groups such as carboxyl groups, sulfonic acid groups, hydroxyl groups, or amino groups, polar groups or reactive groups can be introduced. Furthermore, if a compound further contains lipophilic groups such as long-chain alkyl groups, long-chain alkyl ester groups, or long-chain alkoxy groups, the solubility in solvents and the flexibility of the resin can be improved. There are no particular restrictions on the mercapto group-containing compounds used in the enthiol reaction. Examples include thioglycerol, methyl mercaptan, ethyl mercaptan, n-propyl mercaptan, isopropyl mercaptan, n-butyl mercaptan, sec-butyl mercaptan, tert-butyl mercaptan, isobutyl mercaptan, n-amyl mercaptan, sec-amyl mercaptan, tert-amyl mercaptan, isoamyl mercaptan, activated amyl mercaptan, n-hexyl mercaptan, sec-hexyl mercaptan, n-heptyl mercaptan, sec-heptyl mercaptan, n-octyl mercaptan, sec-octyl mercaptan, n-no Examples include nyl mercaptan, sec-nonyl mercaptan, n-decyl mercaptan, n-dodecyl mercaptan, n-cetyl mercaptan, monothioethylene glycol, monothiopropylene glycol, α-monothioglycerin, monothioethylene chlorhydrin, 3-chloropropyl mercaptan, thioglycolic acid, thiohydroacrylic acid, thiolactic acid, thiomalic acid, mercaptopropanesulfonic acid, thioethanolamine, β-diethylamine ethyl mercaptan, γ-diethylaminopropyl mercaptan, β-nitroethyl mercaptan, thiophenol, thiocresol, thiosalicylic acid, alkyl esters of thioalkyl acids, alkylamides, etc. These may be used individually or in combination of two or more.

[0050] The method for adding a mercapto group-containing compound to an ethylenically active carbon-carbon double bond in a polyester resin is carried out in accordance with generally known addition reactions to unsaturated double bonds. In a method for adding a mercapto group-containing compound to an ethylenically charged carbon-carbon double bond in a polyester resin, there are no particular restrictions on the amount of the mercapto group-containing compound added to the polyester resin, but it is preferably 0.02 to 2 molar equivalents, more preferably 0.2 to 1 molar equivalent, relative to the ethylenically charged carbon-carbon double bond in the polyester resin.

[0051] The enthiol reaction may be carried out without a catalyst, but a catalyst may be used if necessary. There are no particular restrictions on the catalyst, and examples include azobisisobutyronitrile, azobiscyanovalelic acid, benzoyl peroxide, lauroyl peroxide, cumenehydroperoxide, methyl ethyl ketone peroxide, ammonium persulfate, potassium persulfate, and hydrogen peroxide. These may be used individually or in combination of two or more. There are no particular restrictions on the amount of catalyst used, but it is preferably 0.1 to 5 parts by mass per 100 parts by mass of the mercapto group-containing compound.

[0052] The addition reaction of mercapto group-containing compounds may be carried out in a molten state by means of reaction extrusion, or in a solid-liquid reaction or solution reaction using a solvent. When a solvent is used, there are no particular restrictions on the solvent, and examples include hydrocarbon solvents such as cyclohexane, toluene, xylene, nitrobenzene, turpentine, pentane, and naphthene; chlorine solvents such as trichloroene, perchloroene, chloroform, and carbon tetrachloride; ether solvents such as methyl cellosolve, ethyl cellosolve, diethyl cellosolve, dioxane, and tetrahydrofuran; amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; hydrophilic solvents such as methanol, ethanol, impropanol, butanol, and dimethyl sulfoxide; and water. These may be used individually or in combination of two or more.

[0053] There are no particular restrictions on the reaction temperature for the enthiol reaction, but it is preferably 0 to 300°C, and more preferably 40 to 250°C. There are no particular restrictions on the reaction atmosphere for the enthiol reaction, but it is preferable to carry out the reaction under an inert gas stream. There are no particular restrictions on the reaction time for the enthiol reaction, but it is preferably 1 second to 10 hours, more preferably 10 seconds to 5 hours, even more preferably 20 seconds to 1 hour, particularly preferably 30 seconds to 30 minutes, and most preferably 1 minute to 20 minutes.

[0054] If the reaction is a solution reaction, the product may be used as is in solution form after the reaction is complete, or it may be used after obtaining a solid product through processes such as solvent removal, purification, and drying. In the case of a melt reaction such as reaction extrusion, the product may be pelletized using a pelletizer or processed into fiber form by melt spinning.

[0055] <Other processes> Other than the above, there are no particular restrictions; one type may be used alone, or two or more types may be used.

[0056] [Molded body] The molded article of the present invention contains the polyester resin of the present invention. The shape of the molded article is not particularly limited as long as it is a molded article that can be manufactured using the polyester resin of the present invention or a polyester resin composition containing the polyester resin. Examples include pellets, films, sheets, plates, pipes, tubes, bottles, fibrous bodies, rod-shaped bodies, fine particles, particulate bodies, foams, and the like. There are no particular restrictions on the method of manufacturing the molded article, and examples include injection molding, blow molding, press molding, extrusion molding, calendering, and molding by a 3D printer. When the above-mentioned molded body is a film, there are no particular restrictions on the thickness of the film, but it is preferably 5 to 500 μm, more preferably 25 to 300 μm, and most preferably 50 to 200 μm. There are no particular restrictions on the content of the polyester resin of the present invention in the molded article of the present invention, but it is preferably 50 to 100% by mass, more preferably 60 to 95% by mass, and particularly preferably 70 to 90% by mass. If the value is above the lower limit of the above range, high reactivity can be expected, and if it is below the upper limit of the above range, fiber strength can be guaranteed.

[0057] [fiber] The fiber of the present invention contains the polyester resin of the present invention. The polyester resin of the present invention can be suitably used in various fiber applications by taking advantage of its excellent reactivity in electron beam crosslinking.

[0058] There are no particular restrictions on the content of the polyester resin of the present invention in the fibers of the present invention, but it is preferably 50 to 100% by mass, more preferably 60 to 95% by mass, and particularly preferably 70 to 90% by mass. If the value is above the lower limit of the above range, high reactivity can be expected, and if it is below the upper limit of the above range, fiber strength can be guaranteed.

[0059] [Fibers for tires] The tire fibers of the present invention include the fibers of the present invention. The fibers of the present invention, taking advantage of their excellent reactivity in electron beam crosslinking, can be suitably used in various tire fiber applications.

[0060] There are no particular restrictions on the content of the fibers of the present invention in the tire fibers of the present invention, but it is preferably 50 to 100% by mass, more preferably 60 to 95% by mass, and particularly preferably 70 to 90% by mass. If the value is above the lower limit of the above range, high reactivity can be expected, and if it is below the upper limit of the above range, fiber strength can be guaranteed. [Examples]

[0061] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples. In the examples and comparative examples, "%" and "parts" refer to "mass%" and "parts by mass," respectively, unless otherwise specified. The measurement and evaluation methods used in the following examples and comparative examples are shown below.

[0062] [Method for measuring the content (denaturation rate) of structural units derived from unsaturated diol compounds] 1 The measurement was performed by 1H NMR (solvent: deuterated trifluoroacetic acid). The measurement conditions were as follows. The measurement results are shown in Table 1. Using the LAMBDA 500 nuclear magnetic resonance spectrometer manufactured by JEOL Ltd., modified polyester resin was subjected to a reaction at room temperature. 1The 1H NMR spectrum was measured, and the modification rate of the modified polyester resin [content of structural units derived from unsaturated diol compounds (mol%) relative to all structural units] was calculated from the integral values ​​of the peaks (5.0-7.5 ppm) of structural units derived from unsaturated diol compounds. For example, in Example 1, the modification rate was calculated from the integral values ​​of the peaks of structural units derived from unsaturated diol compounds that appeared around 5.1 ppm and 5.6 ppm.

[0063] [Measurement of number-average molecular weight (Mn) and weight-average molecular weight (Mw)] The number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution were calculated using a size-exclusion high-performance liquid chromatography system manufactured by Shimadzu Corporation. The measurement conditions were as follows. The measurement results are shown in Table 1. Columns: Two Tosoh Corporation HFIP series columns "GMHHR-H(S)" connected in series. Standard sample: Polymethyl methacrylate resin (PMMA) Solvent and mobile phase: 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) Flow rate: 0.35mL / min Temperature: 40℃ Sample solution concentration: 0.1% by mass (filtered through a 0.45 μm aperture filter) Injection volume: 10μL Detector: LC-20AD (RI detector)

[0064] [Evaluation of electron beam crosslinking properties] The modified polyester resins obtained in each of the examples and comparative examples described later were formed by hot pressing to produce films with a thickness of approximately 100 μm. The obtained films were sealed under a nitrogen atmosphere and subjected to electron beam irradiation at 500 kGy. After electron beam irradiation, the films were immersed in a large amount of hexafluoro-2-propanol (HFIP) solution and heated in a water bath at 50°C for 1 hour. If solid matter remained, it was determined that gelling had occurred. If no gelling had occurred, the weight-average molecular weight was determined by GPC measurement, and the change in molecular weight before and after electron beam irradiation was confirmed. The electron beam crosslinkability was evaluated using the following evaluation criteria. The evaluation results are shown in Table 1. <Evaluation Criteria> A (Good): Gel formation present B (Acceptable): No gels are present, but the weight-average molecular weight after electron beam irradiation is 2.5 times or more than before irradiation. C (Poor): No gelling material is present, and the weight-average molecular weight after electron beam irradiation is less than 2.5 times that of before irradiation.

[0065] [Evaluation of stringiness] The modified polyester resins obtained in each of the examples and comparative examples described later were placed in a flow tester, melted at their respective polymerization temperature + 10 degrees Celsius for 5 minutes, and then extruded. It was then determined whether or not the extruded molten resin was stringy. The evaluation results are shown in Table 1. A (Good): It is producing strings of thread. B (Poor): Does not string and becomes rubbery.

[0066] (Example 1) In a separable flask equipped with a stirrer, T-joint, top thermometer, Liebig condenser, vacuum meter, diaphragm pump / vacuum pump, round-bottom flask, and nitrogen inlet tube, 95.7 parts by mass of bis(2-hydroxyethyl) terephthalate (BHET) and 4.3 parts by mass of 2-methylene-1,3-propanediol (MPDA) (6.5 mol% / total structural units) were charged. 0.0523 parts by mass of tetrabutoxytitanium as titanium(IV) alkoxide (titanium concentration of 100 ppm by mass relative to the resin) was dissolved in 5 parts by mass of ethylene glycol and added, and thoroughly mixed. After purging the reactor with a flow of nitrogen, the temperature was raised to 240°C in a salt bath while stirring. At atmospheric pressure (1013 hPa), stirring was continued while gradually raising the temperature to 255°C until the distillation of ethylene glycol stopped and the thermometer in the T-joint read below 100°C. Subsequently, the pressure was reduced to 50 Torr (6666 Pa) using a diaphragm pump. The pressure was then reduced further to 0.5 Torr (66 Pa) using a vacuum pump, and the reaction was continued while raising the temperature to 275°C (polymerization temperature). The reaction was allowed to proceed for a total polymerization time of 220 minutes. After releasing the vacuum by nitrogen leakage, the contents were removed. The resulting polymer was pulverized and then vacuum-dried overnight at 80°C to obtain MPDA-modified polyester resin.

[0067] In a three-necked flask equipped with a stirrer, stopcock, reflux tube, bubbler, three-way stopcock, and nitrogen inlet tube, 10 parts by mass of the MPDA-modified polyester resin obtained in Example 1 and 0.3 parts by mass of thioglycerol were added, and the mixture was heated at 240°C using a salt bath (salt bath furnace) and reacted for 60 minutes. The reaction product was removed, 1 Structural analysis performed using 1H NMR confirmed that the following reactions were occurring.

[0068] [ka]

[0069] (Examples 2-8, Comparative Examples 1-2) In Example 1, a modified polyester resin was produced in the same manner as in Example 1, except that the unsaturated diol compound (modified monomer species), the amount of unsaturated diol compound (modified monomer species) charged, the polymerization temperature, and the total polymerization time were changed as shown in Table 1. The physical properties of the obtained modified polyester resin are shown in Table 1.

[0070] [Table 1]

[0071] Table 1 shows that the modified polyester resins of Examples 1 to 8, which have one or more ethylenic carbon-carbon double bonds in the side chain portion of the structural unit derived from the unsaturated diol compound, exhibit improved reactivity in electron beam crosslinking. [Industrial applicability]

[0072] According to the present invention, it is possible to provide a polyester resin with improved reactivity in electron beam crosslinking, a method for producing the same, a molded article containing the polyester resin, a fiber containing the polyester resin, a fiber for tires containing the fiber, and a reaction method using the polyester resin. The polyester resin of the present invention can be used for crosslinking triggered by electron beams, chemical modification by enthiol reactions, chemical modification by Diels-Alder reactions, and the like. There are no particular limitations on the uses of the polyester resin and molded articles of the present invention, and examples include: disposable or reusable food utensils such as food bags, food caps, food trays, straws, cutlery, food containers, coffee capsules, and bottles; stoppers and cap liners for containers that store food, beverages, medicines, etc.; single-layer or multi-layer films and sheets such as electronic component packaging materials, pharmaceutical packaging materials, food packaging films, agricultural materials such as agricultural mulch films and compost bags, civil engineering and construction materials, and industrial materials; daily necessities such as seedling pots, cosmetic containers, detergent containers, bleach containers, shopping bags and garbage bags, laminate films, boards, stretched sheets, sanitary cover stock materials, outdoor leisure products, water-retaining sheets, cooler boxes, cushioning films, and synthetic paper; fishing lines, fishing nets, vegetation nets, monofilaments, flat yarns, staples, crimped fibers, and ribs. Fibers such as adhesive tapes, split yarns, ropes, binding materials, composite fibers, woven fabrics and nonwoven fabrics; adhesives and bonding agents such as solvent-based, hot-melt-based, and heat-stretch-based types; coating agents such as aqueous-based, solution-based, emulsion-based, and dispersion-based types; medical materials such as surgical threads, sutures, artificial bones, artificial skin, DDS such as microcapsules, wound dressings, etc.; filaments for 3D printers; toner for developing; support materials for hydraulic fracturing and water loss prevention agents for excavation; various vibration-damping and vibration isolation materials such as vibration-damping rubber, mats, sheets, cushions, dampers, pads, and mounting rubbers; components such as casings for home appliances such as televisions, stereos, vacuum cleaners, and refrigerators, or for mobile phones; automotive interior and exterior parts such as bumper parts, body panels, weatherstrips, grommets, instrument panels, airbag covers, etc.; various grips such as scissors, screwdrivers, toothbrushes, and ski poles; These are some examples. These may be used individually or in combination of two or more types. Furthermore, when the polyester resin and molded articles of the present invention are used in cosmetic bottles and the like, improved barrier performance through electron beam crosslinking is expected to enhance chemical resistance and other properties.

Claims

1. A polyester resin having structural units derived from a dicarboxylic acid compound and structural units derived from an unsaturated diol compound, The structural unit derived from the unsaturated diol compound comprises a linear portion, two oxygen atoms derived from hydroxyl groups bonded to both ends of the linear portion, and a side chain portion branching from the linear portion and having one or more ethylenic carbon-carbon double bonds, wherein the resulting polyester resin is provided.

2. The polyester resin according to claim 1, wherein the ethylenic carbon-carbon double bond is a carbon-carbon double bond containing a methylidene group.

3. The polyester resin according to claim 1, wherein the structural unit derived from the dicarboxylic acid compound is a structural unit derived from an aromatic dicarboxylic acid compound.

4. The polyester resin according to claim 1, wherein the structural unit derived from the unsaturated diol compound is a structural unit derived from an unsaturated diol compound with a 1,1-disubstituted olefin structure.

5. The polyester resin according to claim 4, wherein the structural unit derived from the unsaturated diol compound is a structural unit derived from 2-methylene-1,3-propanediol.

6. The polyester resin according to claim 1, wherein the content of structural units derived from the unsaturated diol compound is 0.1 to 30 mol% with respect to 100 mol% of the total amount of structural units in the polyester resin.

7. The polyester resin according to claim 1, wherein the number average molecular weight is 3000 or more and the molecular weight distribution is 5 or less.

8. A method for producing a polyester resin according to any one of claims 1 to 7, A method for producing a polyester resin, comprising a polycondensation step of polycondensing the dicarboxylic acid compound, the unsaturated diol compound containing an ethylenic carbon-carbon double bond, and a saturated diol compound.

9. The method for producing a polyester resin according to claim 8, wherein the polycondensation temperature in the polycondensation step is 250°C or less.

10. A molded article comprising the polyester resin according to any one of claims 1 to 7.

11. A fiber containing the polyester resin according to any one of claims 1 to 7.

12. A fiber for tires comprising the fiber described in claim 11.

13. A reaction method comprising a post-reaction step in which an ethylenically charged carbon-carbon double bond contained in a polyester resin according to any one of claims 1 to 7 is used as a reaction site for a post-reaction, A reaction method wherein the post-reaction in the aforementioned post-reaction step is one or more selected from the group consisting of a thermal radical reaction, a UV radical reaction, a redox radical reaction, an electron beam-triggered reaction, an enthiol reaction, a vulcanization reaction, a Diels-Alder reaction, a hydrosilylation reaction, a hydroboration reaction, an epoxidation reaction, a cyclization reaction, and a diolation reaction.

Images