N-vinyl lactam copolymer and method for producing the same

Abstract

The purpose of the present invention is to provide an N-vinyl lactam copolymer that suppresses yellowing under high temperature conditions, and that, for example, when a fiber raw material resin is processed, is compatible with the resin and has suppressed thermal decomposition. A copolymer according to the present invention is an N-vinyl lactam copolymer that has a structural unit (a) derived from an N-vinyl lactam monomer and a structural unit (b) derived from an oxazoline monomer, and that has a substituent containing a phosphorous atom.

Description

[Technical Field]

[0001] This disclosure relates to N-vinyl lactam copolymers and methods for producing the same. [Background technology]

[0002] N-vinyl lactam polymers, such as polyvinylpyrrolidone, are widely used in various fields as water-soluble and safe functional polymers. For example, they are used in cosmetics, pharmaceutical and agricultural chemical intermediates, food additives, photosensitive electronic materials, tackifiers, and various special industrial applications (e.g., the manufacture of hollow fiber membranes).

[0003] For example, Patent Document 1 discloses an N-vinyllactam copolymer having structural units derived from an N-vinyllactam monomer and structural units derived from a hydrophobic monomer, and having substituents containing a phosphorus atom at the ends of the main chain. Patent Document 1 also discloses that the N-vinyllactam copolymer can suppress the decrease in mechanical strength of fibers and improve hygroscopicity and color resistance, and is therefore suitable for use in textile products and the like. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-119030 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] As mentioned above, although N-vinyllactam polymers that exhibit little discoloration even when mixed with resin raw materials for fibers under high-temperature conditions are known, there was a problem that the strength of the fibers decreased when the resin and N-vinyllactam polymer were incompatible during processing of the resin raw materials for fibers. Furthermore, when mixed under high-temperature conditions, the N-vinyllactam polymer under thermal decomposition occurred, and the gases produced by this decomposition reduced the strength of the resin and worsened the working environment. Therefore, the present invention aims to provide an N-vinyl lactam copolymer that suppresses yellowing under high-temperature conditions, is compatible with resins, and is susceptible to thermal decomposition, for example, during the processing of resins used as raw materials for fibers. [Means for solving the problem]

[0006] The copolymer of this disclosure is an N-vinyllactam copolymer having a structural unit (a) derived from an N-vinyllactam monomer and a structural unit (b) derived from an oxazoline monomer, and having substituents including a phosphorus atom.

[0007] The phosphorus atom content is preferably 0.01 to 1.5% by mass per 100% by mass of the N-vinyl lactam copolymer.

[0008] The above N-vinyllactam copolymer preferably has a content of 70 to 97% by mass of structural units (a) derived from the N-vinyllactam monomer and a content of 3 to 30% by mass of structural units (b) derived from the oxazoline monomer, relative to 100% by mass of structural units derived from the total monomer.

[0009] The above N-vinyl lactam copolymer preferably has a K value of 15 to 60.

[0010] The above N-vinyl lactam copolymer preferably has a weight-average molecular weight of 10,000 or more and 500,000 or less.

[0011] The present invention is also a hygroscopic agent containing the above-mentioned N-vinyl lactam copolymer.

[0012] The present invention is also a compatibilizer containing the above N-vinyl lactam-based copolymer.

[0013] The present invention is also a resin composition containing the above N-vinyl lactam-based copolymer, polyester, and / or polyamide.

[0014] The present invention is also a method for producing an N-vinyl lactam-based copolymer, which includes a step of polymerizing a monomer component containing an oxazoline-based monomer and an N-vinyl lactam-based monomer in the presence of a phosphorus atom-containing compound.

[0015] The phosphorus atom-containing compound is preferably hypophosphorous acid (salt). [Advantages of the Invention]

[0016] According to the present disclosure, it is possible to provide an N-vinyl lactam-based copolymer capable of suppressing elution from, for example, fibers while suppressing yellowing under high-temperature conditions, and a method for producing the same. [Modes for Carrying Out the Invention]

[0017] Hereinafter, embodiments of the present disclosure will be described in detail. The following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0018] [N-vinyl lactam-based copolymer] The N-vinyl lactam-based copolymer of the present disclosure (hereinafter, also referred to as the copolymer of the present disclosure) has a structural unit (a) derived from an N-vinyl lactam-based monomer and a structural unit (b) derived from an oxazoline-based monomer, and has a substituent containing a phosphorus atom.

[0019] [Structural unit derived from N-vinyl lactam-based monomer] The copolymers of this disclosure include structural units (a) derived from N-vinyllactam monomers. In this disclosure, structural units (a) derived from N-vinyllactam monomers are typically structural units formed by the polymerization of N-vinyllactam monomers, but are not limited to structures actually formed by the polymerization of N-vinyllactam monomers. Structural units formed by other methods also qualify as structural units (a) derived from N-vinyllactam monomers, as long as they have the same structure as structures formed by the polymerization of N-vinyllactam monomers. Preferably, structural units (a) are structural units having a structure in which at least one of the carbon-carbon double bonds contained in the N-vinyllactam monomer is replaced by a carbon-carbon single bond.

[0020] In this disclosure, the N-vinyllactam monomer is preferably a compound comprising at least one carbon-carbon double bond and at least one cyclic lactam ring structure, and may have other groups. The cyclic lactam ring structure is not particularly limited, but is preferably a 4-membered to 7-membered ring, and more preferably a 5-membered or 6-membered ring.

[0021] The above N-vinyl lactam monomer is given by the following formula (1);

[0022] [ka]

[0023] (In the formula, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 ) represents an alkyl group having 1 to 10 carbon atoms, which may have hydrogen atoms or substituents, and may be the same or different. x represents an integer from 0 to 4. y represents an integer from 1 to 3. The structure is preferably represented by ). The above R 1 ~R 6The number of carbon atoms of the alkyl group is preferably 1 to 6, more preferably 1 to 4. The above alkyl group is more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. The above R 1 ~R 6 The substituents in are not particularly limited, and examples include a carboxyl group, a sulfonic acid group, and esters and salts thereof. R 1 ~R 3 is preferably a hydrogen atom. R 4 ~R 6 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom. x is preferably an integer of 0 to 2, more preferably an integer of 0 to 1, and most preferably 0. y is preferably 1 or 2, and more preferably 1.

[0024] The N-vinyl lactam-based monomer is not particularly limited, and examples include N-vinyl-2-pyrrolidone, N-vinylcaprolactam, N-vinyl-4-butylpyrrolidone, N-vinyl-4-propylpyrrolidone, N-vinyl-4-ethylpyrrolidone, N-vinyl-4-methylpyrrolidone, N-vinyl-4-methyl-5-ethylpyrrolidone, N-vinyl-4-methyl-5-propylpyrrolidone, N-vinyl-5-methyl-5-ethylpyrrolidone, N-vinyl-5-propylpyrrolidone, N-vinyl-5-butylpyrrolidone, N-vinyl-4-methylcaprolactam, N-vinyl-6-methylcaprolactam, N-vinyl-6-propylcaprolactam, N-vinyl-7-butylcaprolactam, etc. Among them, N-vinyl-2-pyrrolidone is preferable. The copolymer of the present disclosure contains one or more structural units (a) derived from an N-vinyl lactam-based monomer.

[0025] <Structural unit derived from oxazoline-based monomer> The copolymers of this disclosure include structural units (b) derived from oxazoline monomers. In this disclosure, structural units (b) derived from oxazoline monomers are typically structural units formed by the polymerization of oxazoline monomers, but are not limited to structures actually formed by the polymerization of oxazoline monomers. Structural units formed by other methods are also considered structural units (b) derived from oxazoline monomers as long as they have the same structure as structures formed by the polymerization of oxazoline monomers. Preferably, structural units (b) are structural units having a structure in which at least one of the carbon-carbon double bonds contained in the oxazoline monomer is replaced by a carbon-carbon single bond.

[0026] In this disclosure, the oxazoline monomer is preferably a compound comprising at least one carbon-carbon double bond and at least one oxazoline group, but may also have other groups. The above oxazoline monomer is given by the following formula (2);

[0027] [ka]

[0028] (In the formula, R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 ) represents an alkyl group having 1 to 10 carbon atoms, which may have hydrogen atoms or substituents, and z represents an integer from 0 to 4.

[0029] The above R 7 ~R 13 The preferred range of carbon atoms in the alkyl group, preferred form, and specific examples of substituents are as follows: 7 ~R 13 It is similar to that. The above R 7 ~R 13The substituents in are not particularly limited, but examples include carboxyl groups, sulfonic acid groups, and esters and salts thereof. R 7 , R 8 A hydrogen atom is preferred as the atom. R 9 A methyl group is preferred as the component. R 10 ~R 13 Preferably, the element is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom. z is preferably an integer between 0 and 2, more preferably an integer between 0 and 1, and most preferably 0.

[0030] The oxazoline monomers are not particularly limited, but examples include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-4,4-dimethyl-2-oxazoline, 2-vinyl-4-ethyl-2-oxazoline, 2-vinyl-4-propyl-2-oxazoline, 2-vinyl-4-butyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-vinyl-5-ethyl-2-oxazoline, and 2- Vinyl oxazolines with or without substitution, such as nyl-5-propyl-2-oxazoline and 2-vinyl-5-butyl-2-oxazoline; 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-4,4-dimethyl-2-oxazoline, 2-isopropenyl-4-ethyl-2-oxazoline, 2-isopropenyl-4-propyl-2-oxazoline, 2-isopropenyl Isopropenyl oxazolines with or without substitution, such as nyl-4-butyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2-isopropenyl-5-propyl-2-oxazoline, and 2-isopropenyl-5-butyl-2-oxazoline; 2-allyl-2-oxazoline, 2-allyl-4-methyl-2-oxazoline, and 2-allyl-4,4-di Examples include methyl-2-oxazoline, 2-allyl-4-ethyl-2-oxazoline, 2-allyl-4-propyl-2-oxazoline, 2-allyl-4-butyl-2-oxazoline, 2-allyl-5-methyl-2-oxazoline, 2-allyl-5-ethyl-2-oxazoline, 2-allyl-5-propyl-2-oxazoline, 2-allyl-5-butyl-2-oxazoline, and other substituted or unsubstituted allyloxazolines.

[0031] Among these, substituted or unsubstituted isopropenyloxazolines are preferred, and 2-isopropenyl-2-oxazoline is more preferred. The substituents are preferably alkyl groups having 1 to 10 carbon atoms, and more preferably alkyl groups having 1 to 4 carbon atoms. The copolymers of this disclosure contain one or more structural units (b) derived from oxazoline monomers.

[0032] <Other monomer-derived structural units> The copolymers of this disclosure may optionally include structural units derived from monomers other than structural units (a) derived from N-vinyllactam monomers and structural units (b) derived from oxazoline monomers (hereinafter also referred to as structural units (c) derived from other monomers). In this disclosure, structural units (c) derived from other monomers are preferably structural units having a structure in which at least one of the carbon-carbon double bonds contained in monomers other than N-vinyllactam monomers and oxazoline monomers is replaced by a carbon-carbon single bond.

[0033] Other monomers are not particularly limited, but include acrylic acid esters such as methyl acrylate and ethyl acrylate; methacrylic acid esters such as methyl methacrylate and ethyl methacrylate; aromatic vinyl monomers such as styrene and vinyltoluene; vinyl esters such as vinyl acetate and vinyl propionate; unsaturated nitriles such as acrylonitrile and methacrylonitrile; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; amide group-containing monomers such as (meth)acrylamide, N-methyl(meth)acrylamide, N-vinylacetamide, and N-vinylformamide; olefin monomers such as isobutylene and 1-octene; 2-(dimethylamino)ethyl acrylate and 2-(dimethylamino) methacrylate Examples include amino group-containing monomers such as ethyl, vinylamine, N-vinylimidazole, and N-vinylcarbazole; sulfonate-containing monomers such as vinyl sulfonates and styrene sulfonates; polyalkylene glycol chain-containing monomers such as (meth)acrylic acid esters of methoxypolyethylene glycol and (meth)acrylic acid esters of phenoxypolyethylene glycol; phosphorus-containing monomers such as phosphate ester-containing monomers and phosphate base-containing monomers; carboxylate-containing monomers such as acrylates, methacrylates, and maleates; hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate, (meth)allyl alcohol, isoprenol, and compounds obtained by adding alkylene oxides to these; and so on. The copolymers of this disclosure may optionally contain one or more structural units (c) derived from other monomers.

[0034] <Substituents containing phosphorus atoms> The copolymers of this disclosure have substituents containing phosphorus atoms. The position of the substituents containing phosphorus atoms in the copolymers of this disclosure is not particularly limited, but preferably the copolymers of this disclosure have substituents containing phosphorus atoms in the main chain. The substituent containing the phosphorus atom may be, for example, a group derived from a phosphorus-containing monomer as one of the other monomers mentioned above, or a group derived from a chain transfer agent described later. The substituent containing the phosphorus atom is not particularly limited as long as it contains a phosphorus atom, but it is preferably a reducing group. Examples of the substituent containing a phosphorus atom having reducibility include a hypophosphite (salt) group, a phosphite (salt) group, and the like. More preferably, it is a hypophosphite (salt) group. In the present disclosure, the hypophosphite (salt) group means a hypophosphite group or a salt thereof, and the phosphite (salt) group means a phosphite group or a salt thereof. Examples of the salt include metal salts, ammonium salts, organic amine salts, etc. More specifically, examples of the metal salt include salts of alkali metals such as sodium salt and potassium salt; salts of alkaline earth metals such as magnesium salt, calcium salt, strontium salt, and barium salt; salts such as aluminum salt and iron salt. Examples of the organic amine salt include alkanolamine salts such as monoethanolamine salt, diethanolamine salt, and triethanolamine salt; alkylamine salts such as monoethylamine salt, diethylamine salt, and triethylamine salt; morpholine salt, etc. Among these, as the salt, sodium salt, potassium salt, calcium salt, and ammonium salt are preferable.

[0035] Among the above, it is particularly preferable to have a hypophosphite (salt) group. As will be described later, in the presence of hypophosphite (salt), by polymerizing a monomer composition containing an N-vinyl lactam-based monomer and an oxazoline-based monomer, it is possible to efficiently introduce a substituent containing a phosphorus atom to the main chain terminal by chain transfer. Incidentally, since hypophosphite (salt) acts as a divalent chain transfer agent, when introduced to the molecular main chain terminal, it may be -P(=O)(-OX)H, and when introduced into the molecular main chain interior, it may be -P(=O)(-OX)-. The above X is a hydrogen atom, a metal salt, an ammonium salt, an organic amine salt, etc. The copolymer of the present disclosure contains one or more substituents containing a phosphorus atom. The type of the substituent containing a phosphorus atom is, for example 31 It can be confirmed by PNMR or the like.

[0036] <Composition of N-vinyl lactam-based copolymer, etc.> The copolymer of the present disclosure preferably contains structural unit (a) derived from an N-vinyl lactam monomer in a proportion of 70% to 99% by mass, more preferably 75% to 98% by mass, even more preferably 80% to 97% by mass, even more preferably 80% to 96% by mass, and particularly preferably 80% to 95% by mass, based on 100% by mass of structural units derived from the total monomer (referring to the sum of structural units (a), structural unit (b), and structural unit (c)). By including it within the above range, for example, when the copolymer of the present disclosure is used as a modifier for fibers, it tends to efficiently impart moisture absorption and release properties, and also tends to suppress elution from the resin and yellowing under high-temperature conditions.

[0037] The copolymer of the present disclosure preferably contains structural unit (b) derived from the oxazoline monomer in a proportion of 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 25% by mass or less, even more preferably 3% by mass or more and 20% by mass or less, even more preferably 4% by mass or more and 20% by mass or less, and particularly preferably 5% by mass or more and 20% by mass or less, based on 100% by mass of structural units derived from the total monomer (referring to the sum of structural units (a), structural unit (b), and structural unit (c)). By containing structural unit (b) within the above range, for example, when the copolymer of the present disclosure is used as a modifier for fibers, it tends to efficiently impart moisture absorption and release properties and tends to suppress yellowing under high-temperature conditions. In particular, when kneaded with resins containing carboxyl groups, such as polyester resins and polyamide resins, the reaction between the oxazoline group and the carboxyl group tends to suppress leaching from the resin and improve compatibility, thereby suppressing a decrease in strength.

[0038] The content of structural unit (c) derived from other monomers in the copolymer of this disclosure is arbitrary and not particularly limited, but is preferably 0% by mass or more and 5% by mass or less, more preferably 0% by mass or more and 1% by mass or less, even more preferably 0% by mass or more and 0.5% by mass or less, and particularly preferably 0% by mass or more and 0.1% by mass or less, based on 100% by mass of structural units derived from all monomers (the sum of structural units (a), structural units (b), and structural units (c)). By including within the above range, it is possible to impart other characteristics while utilizing the characteristics of the copolymer of this disclosure, for example. Note that in the above range, if the structural unit derived from other monomers is a structural unit derived from a salt of a monomer containing an acid group, it is calculated by mass as a structural unit derived from the corresponding monomer containing an acid group. Similarly, if the structural unit derived from other monomers is a structural unit derived from a salt of a monomer containing an amino group, it is calculated by mass as a structural unit derived from the corresponding monomer containing an amino group. For example, if it is a structural unit derived from sodium acrylate, it is calculated by mass as a structural unit derived from acrylic acid, which is the corresponding acid.

[0039] The copolymer of this disclosure has substituents containing phosphorus atoms, and preferably contains phosphorus atoms in an amount of 0.01% by mass or more and 1.5% by mass or less, more preferably 0.05% by mass or more and 1.0% by mass or less, and even more preferably 0.1% by mass or more and 0.5% by mass or less, based on 100% by mass of the copolymer. By containing phosphorus atoms within the above range, for example, when the copolymer of this disclosure is used as a modifier for fibers, yellowing under high-temperature conditions is suppressed, and compatibility with resins tends to be improved, for example, during processing of resins used as raw materials for fibers. Furthermore, by containing phosphorus atoms within the above range, the heat resistance of the copolymer tends to be improved, for example, by suppressing thermal decomposition of the copolymer during melt kneading with resins or during molding processes, thereby suppressing a decrease in strength due to thermal decomposition and deterioration of the working environment due to gases generated by decomposition. Note that substituents containing phosphorus atoms bonded to the ends of the main chain are substituents containing phosphorus atoms that are included in (or located in) the main chain. The copolymer of this disclosure preferably contains phosphorus atoms in substituents containing phosphorus atoms within the above range, and more preferably contains phosphorus atoms within the above range.

[0040] The amount of phosphorus atoms contained in the copolymer can be calculated, for example, by subtracting the amount of phosphorus atoms contained in the phosphorus-containing compound (excluding the copolymer) in the resulting copolymer-containing composition from the amount of phosphorus atoms contained in the phosphorus-containing compound used in the manufacturing process.

[0041] A composition comprising the copolymer of the present disclosure (hereinafter also referred to as the composition of the present disclosure) may also contain a phosphorus atom-containing compound. In the present disclosure, a phosphorus atom-containing compound means a compound other than the copolymer of the present disclosure that has substituents containing a phosphorus atom. Examples of phosphorus atom-containing compounds include hypophosphorous acid (salt), phosphite (salt), phosphoric acid (salt), hypophosphorous acid ester, phosphite ester, phosphate ester, and the like.

[0042] The composition of this disclosure preferably contains a phosphorus atom-containing compound in an amount of 0.0001 to 1% by mass, more preferably 0.001 to 0.5% by mass, and even more preferably 0.0015 to 0.3% by mass, based on 100% by mass of the copolymer of this disclosure. By including the compound within the above range, for example, when the copolymer of this disclosure is used as a modifier for fibers, yellowing under high-temperature conditions is suppressed, and compatibility with resins tends to be good, for example, during the processing of the resin raw material for fibers. Note that if the phosphorus atom-containing compound is a salt, the above range is calculated by mass as the corresponding acid (hereinafter also referred to as acid conversion). For example, if it is sodium hypophosphite, the mass is calculated as the corresponding acid, which is hypophosphorous acid.

[0043] The composition of the present disclosure preferably contains an N-vinyl lactam monomer in an amount of 0 ppm to 5000 ppm, more preferably 0 ppm to 3000 ppm, and even more preferably 0 ppm to 1000 ppm, based on 100% by mass of the copolymer of the present disclosure.

[0044] The composition of the present disclosure preferably contains an oxazoline monomer in an amount of 0 ppm to 3000 ppm, more preferably 0 ppm to 2000 ppm, and even more preferably 0 ppm to 1000 ppm, based on 100% by mass of the copolymer of the present disclosure.

[0045] The copolymers of this disclosure are not particularly limited, but preferably have a weight-average molecular weight of 10,000 or more and 500,000 or less, more preferably 30,000 or more and 300,000 or less, and even more preferably 50,000 or more and 200,000 or less. Having a weight-average molecular weight within the above range allows the copolymers of this disclosure to suppress yellowing under high-temperature conditions while tending to exhibit good compatibility with resins, for example, during processing of resins used as raw materials for fibers.

[0046] The K value of the above N-vinyllactam copolymer is preferably 15 to 60, more preferably 17 to 45, even more preferably 18 to 40, and particularly preferably 19 to 35, in order to suppress yellowing of the copolymer under high-temperature conditions while maintaining an appropriate viscosity. Here, the K value of the above N-vinyllactam copolymer is a viscosity characteristic value that correlates with the molecular weight of the N-vinyllactam copolymer, and is calculated by applying it to the following Fikentscher formula. K=(1.5logη rel -1) / (0.15+0.003c)+(300clogη rel +(c+1.5clogη rel ) 2 ) 1 / 2 / (0.15c+0.003c 2 ) Here, η rel c is the relative viscosity (at 25°C) of an aqueous solution of N-vinyllactam copolymer relative to water, as measured by a capillary viscometer, and c is the concentration [mass%] of the N-vinyllactam copolymer in the aqueous solution of N-vinyllactam copolymer. The above K value can be measured by the method described in the examples.

[0047] The copolymer of the present disclosure preferably has a color (YI) of 50 or less after heating at 260°C for 60 minutes under a nitrogen atmosphere, more preferably less than 50, even more preferably 40 or less, and particularly preferably less than 40. The color tone of the above copolymer can be measured by the method described in the examples. The compositions of the present disclosure are not particularly limited, but may include, for example, 1% by mass or more and 100% by mass or less of the copolymer of the present disclosure.

[0048] The method for producing the copolymer of this disclosure is not particularly limited, but it is preferable to produce it by the "Method for producing the N-vinyl lactam copolymer of this disclosure" described later.

[0049] [Method for producing N-vinyllactam copolymers] <Polymerization process> The method for producing an N-vinyllactam copolymer according to this disclosure (hereinafter also referred to as the "production method of this disclosure") preferably includes a step of polymerizing a monomer component comprising an N-vinyllactam monomer and an oxazoline monomer (hereinafter also referred to as the "polymerization step"). The monomer component may optionally contain other monomers. Unless otherwise specified, the N-vinyllactam monomer, the oxazoline monomer, and other monomers, as well as preferred embodiments thereof, are as described above. The content of N-vinyllactam monomers in the monomer components is not particularly limited, but is preferably 70% to 99% by mass, more preferably 75% to 98% by mass, even more preferably 80% to 97% by mass, even more preferably 80% to 96% by mass, and particularly preferably 80% to 95% by mass, based on 100% by mass of total monomers (the sum of N-vinyllactam monomers, oxazoline monomers, and other monomers). By including within the above range, for example, when the copolymer of this disclosure is used as a modifier for fibers, it tends to efficiently impart moisture absorption and release properties, and also tends to suppress elution from the resin and yellowing under high-temperature conditions.

[0050] The content of the oxazoline monomer in the monomer component is not particularly limited, but is preferably 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 25% by mass or less, even more preferably 3% by mass or more and 20% by mass or less, even more preferably 4% by mass or more and 20% by mass or less, and particularly preferably 5% by mass or more and 20% by mass or less, based on 100% by mass of the total monomer. By including it within the above range, for example, when the copolymer of the present disclosure is used as a modifier for fibers, it tends to efficiently impart moisture absorption and release properties, and also tends to suppress elution from the resin and yellowing under high temperature conditions.

[0051] The content of other monomers in the monomer component is arbitrary and not particularly limited, but is preferably 0% by mass or more and 5% by mass or less, more preferably 0% by mass or more and 1% by mass or less, even more preferably 0% by mass or more and 0.5% by mass or less, and particularly preferably 0% by mass or more and 0.1% by mass or less, based on 100% by mass of the total monomers. By including them within the above range, it is possible to impart other characteristics while making use of the characteristics of the copolymer of this disclosure, for example.

[0052] The polymerization step is preferably carried out in the presence of a phosphorus atom-containing compound. By chain transfer to the phosphorus atom-containing compound, substituents containing phosphorus atoms can be efficiently introduced into the copolymer of this disclosure. Unless otherwise specified, the phosphorus atom-containing compounds and their preferred embodiments are as described above. Due to their high chain transfer efficiency, hypophosphorous acid (salt), phosphorous acid (salt), and hypophosphorous acid esters are preferred, and hypophosphorous acid (salt) is more preferred. When using a phosphorus atom-containing compound, one type or two or more types may be used.

[0053] In the polymerization step, the amount of phosphorus-containing compound used is preferably 0.1 g or more and 5 g or less, and more preferably 0.3 g or more and 1 g or less, per mole of monomer (total monomer) used. Note that if the phosphorus-containing compound is a salt, the above range is calculated by mass using the corresponding acid. For example, if it is sodium hypophosphite, the mass is calculated using the corresponding acid, which is hypophosphorous acid.

[0054] The polymerization step may optionally use chain transfer agents other than phosphorus atom-containing compounds (hereinafter also referred to as other chain transfer agents). Examples of other chain transfer agents include thiol-based chain transfer agents such as mercaptoethanol and mercaptopropionic acid; halides such as carbon tetrachloride and methylene chloride; secondary alcohols such as isopropyl alcohol and glycerin; sulfites such as sodium sulfite; bisulfites such as sodium bisulfite; dithionites such as sodium dithionite; and pyrosulfites such as potassium pyrosulfite. When using the above other chain transfer agents, they may be used alone or in combination of two or more.

[0055] The polymerization step is preferably carried out in the presence of a polymerization initiator. There are no particular restrictions on the polymerization initiator, but examples include hydrogen peroxide; persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylpropionamidine) dihydrochloride, (2,2'-azobis-2-amidinopropane dihydrochloride), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate, and 2,2'-azobis[2-(2- Suitable polymerization initiators include azo compounds such as imidazolin-2-yl)propane, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, and 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride; organic peroxides such as benzoyl peroxide, lauroyl peroxide, peracetic acid, di-t-butyl peroxide, and cumenehydroperoxide; and redox initiators that generate radicals by combining an oxidizing agent and a reducing agent, such as ascorbic acid and hydrogen peroxide, or persulfates and metal salts. Among these polymerization initiators, hydrogen peroxide, persulfates, and azo compounds are preferred, with azo compounds being the most preferred, as they tend to reduce the amount of residual monomers. Among the above azo compounds, 2,2'-azobis(2-methylpropionamidine) dihydrochloride is particularly preferred. These polymerization initiators may be used alone or in the form of a mixture of two or more.

[0056] In the polymerization step, the amount of polymerization initiator used is preferably 0.1 g or more and 10 g or less, more preferably 0.5 g or more and 5 g or less, and even more preferably 1 g or more and 3 g or less, per mole of monomer (total monomer) used.

[0057] The polymerization step is preferably carried out in the presence of a solvent. Examples of solvents include one or more selected from alcohols such as water, methyl alcohol, ethyl alcohol, isopropyl alcohol (2-propanol), n-butyl alcohol, and diethylene glycol. Water and isopropyl alcohol are preferred solvents. Water is more preferred. The amount of solvent used is preferably 40 to 1000% by mass per 100% by mass of monomer.

[0058] The polymerization step is optional, but ammonia and / or amine compounds may be used, for example, to accelerate the polymerization reaction or prevent hydrolysis of N-vinyl lactam. Any suitable amine compound can be used as the amine compound. Specifically, primary amines, secondary amines, tertiary amines, and quaternary ammonium salts are examples. When using the above amine compounds, only one type may be used, or two or more types may be used. When using the above ammonia and amine compounds, the amount used is arbitrary and not particularly limited, but the total amount of both can be used in amounts of 0.01 parts by mass to 1 part by mass per 100 parts by mass of N-vinyl lactam monomer.

[0059] The polymerization step is optional, but other additives may be added. Examples of other additives include inorganic bases such as sodium hydroxide and sodium carbonate; heavy metal salts such as Mohr's salt (Fe(NH4)2(SO4)2·6H2O), ferrous sulfate heptahydrate, ferrous chloride, ferric chloride, copper(I) sulfate and / or its hydrate, copper(II) sulfate and / or its hydrate, copper(II) chloride and / or its hydrate; and ammine complex salts of copper such as diamminecopper salt ([Cu(NH3)2]2SO4·H2O, [Cu(NH3)2]Cl, etc.) and tetraamminecopper salt ([Cu(NH3)4]SO4·H2O, [Cu(NH3)4]Cl2, etc.).

[0060] The polymerization temperature in the polymerization step is preferably 70°C or higher, more preferably 75 to 110°C, and even more preferably 80 to 105°C. When the polymerization temperature is within the above range, the amount of residual monomer components tends to decrease. It should be noted that the polymerization temperature does not need to be kept constant throughout the polymerization reaction. For example, polymerization may be started from room temperature, the temperature may be raised to a set temperature at an appropriate heating time or rate, and then the set temperature may be maintained thereafter. Alternatively, the polymerization temperature may be varied over time (raised or decreased) during the polymerization reaction, depending on the dropwise addition method of monomer components and initiators.

[0061] When the polymerization step is carried out, for example, in the presence of an aqueous solvent, the pH of the reaction system is preferably 6 or higher, more preferably 7 or higher, and preferably 11 or lower. When the pH is within this range, the generation of impurities or by-products in the reaction solution tends to be suppressed.

[0062] The polymerization step can be carried out under pressurized conditions, atmospheric pressure, or reduced pressure, although this is optional. The polymerization step may also be carried out under an inert atmosphere, although this is optional. When carried out under an inert atmosphere, the system may be replaced with an inert gas such as nitrogen before the start of polymerization, or an inert gas may be added during the polymerization step.

[0063] The polymerization time in the polymerization step is not particularly limited, for example, when carried out in a batch reaction, but it is preferably 30 minutes or more and 5 hours or less. Within this range, the discoloration of the polymerization solution tends to be reduced.

[0064] When the polymerization step is carried out in a batch reaction, all raw materials may be added to the reactor before polymerization begins, some raw materials may be added to the reactor before polymerization begins and the remaining raw materials may be added to the reactor continuously or stepwise, or polymerization may be carried out while all raw materials are added to the reactor continuously or stepwise.

[0065] In the polymerization step, it is also possible to add 50% or more, more preferably 70% or more, and even more preferably 90% or more, of 100% by mass of the phosphorus atom-containing compound used to the reactor before the start of polymerization (hereinafter also referred to as initial preparation).

[0066] In the polymerization step, the N-vinyl lactam monomer and the oxazoline monomer may be added to the reactor while the polymerization reaction is taking place, preferably at a rate of 50% or more by mass, more preferably 70% or more, and even more preferably 90% or more, based on 100% by mass of the amount used. In this case, the addition rate does not need to be kept constant during the polymerization reaction, and the addition rate may be changed. The addition rate may be changed once or twice or more.

[0067] In the polymerization step described above, although optional, the polymerization initiator may be added to the reactor while the polymerization reaction is taking place, preferably at a rate of 50% or more by mass, more preferably 70% or more, and even more preferably 90% or more, relative to 100% by mass of the amount used. In this case, the addition rate does not need to be kept constant during the polymerization reaction, and the addition rate may be changed. The addition rate may be changed once or twice or more.

[0068] For the container used in the polymerization process, a container made of stainless steel (SUS) is preferred, and a container equipped with a stirrer is also preferred.

[0069] <Addition process for heat resistance improver> The manufacturing method of the present disclosure may include, for example, a step of adding a heat-resistant agent to the reaction solution after the polymerization reaction is completed (also referred to as the heat-resistant agent addition step). This tends to further improve the heat resistance of the copolymer of the present disclosure. The heat-resistant agent may be added to the copolymer solution or to the dried copolymer.

[0070] The amount of heat-resistant improver used in the manufacturing method of the present disclosure is preferably 0.1 to 10% by mass, more preferably 0.2 to 10% by mass, even more preferably 0.5 to 10% by mass, and even more preferably 0.5 to 8% by mass, based on 100% by mass of the copolymer of the present disclosure. The copolymer or composition of the present disclosure may contain, for example, the heat-resistant improver within the above range.

[0071] The heat resistance improving agent is not particularly limited as long as it improves heat resistance, but examples include phenolic antioxidants, sulfuric antioxidants, phosphorus-based antioxidants, alcoholic antioxidants, amine-based antioxidants, and hindered amine-based antioxidants. Preferably, it is at least one selected from the group consisting of phenolic antioxidants, alcoholic antioxidants, amine-based antioxidants, phosphorus-based antioxidants, and hindered amine-based antioxidants. For example, the antioxidant described in Japanese Patent Application Publication No. 2020-37619 is an example. Among these, BHT, hydroquinone, tocopherol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, and 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene are preferred as phenolic antioxidants.

[0072] <Drying process> The manufacturing method of the copolymer of the disclosure may include a step of removing all or part of the solvent from a solution of the copolymer of the disclosure. The step of obtaining a solid of the copolymer of the disclosure is also called a drying step. The drying step may be carried out by a known general method, such as spray drying, freeze-drying, fluidized bed drying, drum drying, belt drying, etc. When heating and drying at atmospheric pressure, the drying temperature is preferably about 100 to 200°C, and the drying time is preferably about 0.2 to 180 minutes. When drying under reduced pressure, the drying temperature may be appropriately selected according to the degree of reduced pressure. The drying step may also be carried out under an inert atmosphere.

[0073] The manufacturing method of the disclosed herein may optionally include a grinding step for grinding the dried copolymer of the disclosed herein, a classification step for classifying the dried copolymer of the disclosed herein, and a granulation step for granulating the dried copolymer of the disclosed herein. The above steps may be carried out simultaneously with the drying step.

[0074] <Other processes> The manufacturing method of the present disclosure may include any steps other than those described above. Examples include a purification step, a desalting step, a concentration step, a dilution step, a pH adjustment step, and so on. For example, treating the reaction solution (polymerization solution) with a cation exchange resin tends to improve the color of the polymer solution containing the copolymer of the present disclosure.

[0075] [Applications of N-vinyllactam copolymers] The N-vinyl lactam copolymers and compositions of the present disclosure are not particularly limited, but can be used in a variety of applications, such as manufacturing aids for hollow fiber membranes, cleaning agents for semiconductors, additives for adhesives and sealants, manufacturing aids for electronic components, detergent additives, cosmetic additives, thickeners, ink additives, pigment dispersants, dispersants for inorganic particles, additives for paint compositions, surface treatment agents, resin modifiers, binders for inorganic substances, ceramic binders, additives for inorganic compositions, fiber treatment agents, and additives for functional fibers.

[0076] <Resin composition> The copolymers and compositions of the present disclosure may be used as additives to resins such as polyester and polyamide, preferably in melt-kneading applications. The resin may be a resin used for fiber manufacturing. By adding the copolymers of the present disclosure, moisture absorption and release properties and deodorizing properties can be imparted to resins such as polyester. A composition containing the copolymers of the present disclosure and the resin is also referred to as a resin composition of the present disclosure.

[0077] The amount of copolymer of the present disclosure added to a resin such as polyester is preferably such that the mass ratio of the copolymer of the present disclosure to the resin is 99.9:0.1 to 60:40, more preferably 99.5:0.5 to 65:35, even more preferably 99:1 to 70:30, even more preferably 98.8:1.2 to 85:15, particularly preferably 98.5:1.5 to 88:12, and most preferably 98.2:1.8 to 92:8. Within the above range, the moisture absorption and release properties of the resin composition tend to be good, and yellowing and elution of the copolymer of the present disclosure tend to be suppressed.

[0078] In the resin composition of this disclosure, the ratio of mass of structural parts derived from the resin to structural parts derived from the copolymer of this disclosure is preferably 99.9:0.1 to 60:40, more preferably 99.5:0.5 to 65:35, even more preferably 99:1 to 70:30, even more preferably 98.8:1.2 to 85:15, particularly preferably 98.5:1.5 to 88:12, and most preferably 98.2:1.8 to 92:8. The mass of structural parts derived from the copolymer of this disclosure is the sum of (i) the mass of the copolymer of this disclosure and (ii) the mass of structural parts obtained by removing the portion attributable to the resin from the reaction product of the copolymer of this disclosure and the resin. The structural parts derived from the resin are the sum of (iii) the mass of the resin and (iv) the mass of structural parts obtained by removing the portion attributable to the copolymer of this disclosure from the reaction product of the copolymer of this disclosure and the resin.

[0079] The moisture absorption rate of the resin composition of this disclosure is preferably 0.30% or more and 15% or less, more preferably 0.35% or more and 10% or less, and even more preferably 0.40% or more and 8% or less.

[0080] The above-mentioned polyester is not particularly limited, and those used for fiber manufacturing are preferred, but examples include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene isophthalate, polypropylene isophthalate, and polybutylene isophthalate.

[0081] The polyamides mentioned above are not particularly limited, and those used for fiber manufacturing are preferred, but examples include nylon 4, nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, nylon 610, nylon MXD6 (a polycondensate of metaxylylenediamine and adipic acid). A form of the resin composition of the present disclosure comprising an N-vinyl lactam copolymer and a polyester and / or polyamide is one of the preferred embodiments of the present invention.

[0082] The method for producing the resin composition of this disclosure is not particularly limited, but it preferably includes a step of mixing the resin with the copolymer of the present invention. While melt kneading (mixing) is usually preferred, mixing may also be done by dissolving in a solvent.

[0083] The temperature during melt-kneading is not particularly limited, but for example, 200 to 350°C is preferred. More preferably, it is 250 to 320°C, and even more preferably, 260 to 310°C. The time required for the above melting and kneading is not particularly limited, but for example, 1 to 60 minutes is preferred. More preferably, it is 2 to 30 minutes.

[0084] The apparatus for mixing the resin composition of this disclosure is not particularly limited, but a single-screw extruder, a twin-screw extruder, a dual-arm kneader, etc., can be used. The mixing process can be carried out in batches or continuously.

[0085] The resin composition of this disclosure may be manufactured by any other process in addition to the mixing process described above, such as a drying process and a molding process. The resin composition of this disclosure is suitable as a raw material for polyester fibers, but it can also be used for applications other than fibers, so its shape is not particularly limited and can be, for example, pellets, sheets, rods, lumps, or powders.

[0086] The resin composition of this disclosure may contain components other than the resin and the copolymer of this disclosure. Examples of such components include antioxidants such as phenolic compounds, phosphorus compounds and sulfur compounds; plasticizers; flame retardants; pigments such as zinc oxide, magnesium oxide and titanium oxide; and the like.

[0087] <Hygroscopic agent> The copolymers and compositions of the present disclosure can be used as hygroscopic agents for resins and the like. A method for imparting hygroscopic properties to a resin, which includes the step of adding the copolymer of the present disclosure to the resin, is also one of the present inventions. Furthermore, the use of the copolymer of this disclosure to impart hygroscopic properties to the resin is also one aspect of the present invention. The hygroscopic agents of the present disclosure are not particularly limited, but include, for example, 1% by mass or more and 100% by mass or less of the copolymer of the present disclosure. Preferred embodiments of the hygroscopic agents of the present disclosure are the same as those of the copolymers and / or compositions of the present disclosure unless otherwise specified, and preferred embodiments of the hygroscopic agents of the present disclosure when used as resin additives are the same as those of the copolymers and / or compositions of the present disclosure for use as additives to resins unless otherwise specified.

[0088] <Compatibility enhancer> The copolymers and compositions of the present disclosure can be used as compatibility agents for resins and the like. A method for imparting compatibility to a resin, which includes the step of adding the copolymer of the present disclosure to the resin, is also one of the present inventions. Furthermore, the use of the copolymer of this disclosure to impart compatibility to the resin is also one aspect of the present invention. The compatibility agent of the present disclosure is not particularly limited, but comprises, for example, 1% by mass or more and 100% by mass or less of the copolymer of the present disclosure. Preferred embodiments of the compatibility agent of the present disclosure are the same as those of the copolymer and / or compositions of the present disclosure unless otherwise specified, and preferred embodiments of the compatibility agent of the present disclosure when used as a resin additive are the same as those of the copolymer and / or compositions of the present disclosure for use as an additive to resins unless otherwise specified. Furthermore, another preferred embodiment of the present invention is that the compatibility agent is an agent that makes the copolymer contained in the compatibility agent compatible with the resin. [Examples]

[0089] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "percent mass".

[0090] <Measurement of weight-average molecular weight> The weight-average molecular weight was determined by gel permeation chromatography (GPC) under the following conditions. Equipment: Tosoh HLC-8320GPC Detector: RI Columns: Showa Denko Corporation Shodex KD-806M (2 pieces), KD-G 4A Column temperature: 40℃ Flow rate: 0.8ml / min Calibration curve: Polystyrene Standards Eluent: N,N-dimethylformamide (containing 0.1% LiBr).

[0091] <Measurement of solid content of copolymer composition> Weigh out approximately 1 g of the copolymer composition (mass W2 (g)) into a weighing can with a bottom diameter of approximately 5 cm (mass W1 (g)), and leave it standing in a constant-temperature dryer at 150 °C for 1 hour to dry it. Measure the total mass (W3 (g)) of the weighing can and the copolymer after drying, and determine the solid content from the following formula. Solid content (mass %) = [(W3 - W1) / W2] × 100

[0092] <K value> The K value of the polymer was determined by preparing a 1% aqueous polymer solution in terms of solid content, measuring its viscosity at 25 °C using a capillary viscometer (diluted micro-Ubbelohde viscometer I (K = 0.01)) manufactured by LA UDA, and applying it to the above-mentioned Fikentscher's formula for calculation.

[0093] <Measurement of phosphorus atom-containing compounds and phosphorus atoms in the polymer> The phosphorus atom-containing compounds were quantified using ion chromatography. Measurement conditions for ion chromatography: The polymer to be measured was dried under reduced pressure at 80 °C, and the obtained solid content was dissolved in ion-exchanged water to a concentration of 0.5 mass %. It was measured using IC-2010 manufactured by Tosoh Corporation (column: Shodex ICSI-904E, guard column: Shodex ICSI-90G, column temperature: 25 °C, flow rate: 1.2 mL / min, detector: conductivity detector, injection volume: 100 μL, eluent: 0.1 mass % aqueous sodium carbonate solution). From the peak area ratio of ion chromatography, the ions of unreacted phosphorus atom-containing compounds were calculated and subtracted from the added amount to calculate the ratio (mass %) of the structural units containing phosphorus atoms in the polymer.

[0094] <Example 1> In a stainless steel reaction vessel equipped with Maxblend (a registered trademark of Sumitomo Heavy Industries, Ltd.) type stirring blades, a glass lid, a stirrer with a stirring seal, a nitrogen inlet tube, a reflux condenser, and a temperature sensor, 445.0 parts by mass of deionized water, 3.78 parts by mass of sodium hypophosphite monohydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.13 parts by mass of 48% sodium hydroxide aqueous solution were charged, and the temperature of the solution in the reaction vessel was raised to 88-92°C while stirring. Next, maintaining a temperature of 90°C, 403.2 parts by mass of N-vinylpyrrolidone was added dropwise to the reaction vessel over 360 minutes, 100.8 parts by mass of 2-isopropenyl-2-oxazoline was added over 300 minutes starting 1 minute after the start of N-vinylpyrrolidone addition, and 83.2 parts by mass of 10% by mass of 2,2'-azobis(2-methylpropionamidine) dihydrochloride aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, hereinafter referred to as "10% V-50") was added dropwise to the reaction vessel over 360 minutes, each through separate supply routes. The addition of each component was carried out continuously while adjusting the dropping rate. After the addition of 10% V-50 was completed, the temperature was maintained for another 60 minutes to allow maturation, and the polymer composition was obtained. The solid content concentration after polymerization was 50% by mass, and the content of N-vinylpyrrolidone and 2-isopropenyl-2-oxazoline in the obtained copolymer (1) was 80.0% by mass and 20.0% by mass, respectively. The obtained polymer composition was dried under reduced pressure in a vacuum dryer at 90°C (Yamato Scientific Co., Ltd.: Rectangular Vacuum Constant Temperature Dryer DP33) for 5 hours, and the dried material was then pulverized in a lab mill to obtain a powder containing copolymer (1) of the present disclosure. The obtained powder had a solid content of 95.7%, a K value of 36, and a weight-average molecular weight of 95,000. The content of unreacted hypophosphorous acid (sodium) in the powder was 1300 ppm in terms of acid. The amount of phosphorus atoms present in the main chain of the copolymer was 1600 ppm.

[0095] <Example 2> In a stainless steel reaction vessel equipped with Maxblend (a registered trademark of Sumitomo Heavy Industries, Ltd.) type stirring blades, a glass lid, a stirrer with a stirring seal, a nitrogen inlet tube, a reflux condenser, and a temperature sensor, 429.5 parts by mass of deionized water, 3.65 parts by mass of sodium hypophosphite monohydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.14 parts by mass of 48% sodium hydroxide aqueous solution were charged, and the solution in the reaction vessel was heated to 90°C while being stirred. Next, maintaining the temperature at 90°C, 350.2 parts by mass of N-vinylpyrrolidone were added in two stages: 250 minutes for 200 minutes followed by 87.6 parts by mass for 40 minutes. 48.6 parts by mass of 2-isopropenyl-2-oxazoline were added over 300 minutes, starting 1 minute after the start of N-vinylpyrrolidone addition. 9.7 parts by mass of 10% V-50 were added in two stages: 30 minutes followed by 70.5 parts by mass for 330 minutes. Each of these was added dropwise through separate supply routes to the reaction vessel. 2-isopropenyl-2-oxazoline was added continuously at a constant dropwise rate. After the addition of 10% V-50 was completed, the mixture was aged for another 60 minutes while maintaining the temperature at 90°C to obtain the polymer composition. The solid content after polymerization was 50% by mass, and the N-vinylpyrrolidone and 2-isopropenyl-2-oxazoline content in the obtained copolymer (2) was 90% by mass and 10% by mass, respectively. The obtained polymer composition was dried under reduced pressure in a vacuum dryer at 90°C (Yamato Scientific Co., Ltd.: rectangular vacuum constant temperature dryer DP33) for 5 hours, and the dried material was then pulverized in a lab mill to obtain a powder containing copolymer (2) of the present disclosure. The solid content of the obtained powder was 95.3%, the K value was 29, and the weight-average molecular weight was 86,000. The content of unreacted hypophosphorous acid (sodium) in the powder was 640 ppm in terms of acid. The amount of phosphorus atoms present in the main chain of the copolymer was 1900 ppm.

[0096] <Example 3> A stainless steel reaction vessel equipped with Maxblend (a registered trademark of Sumitomo Heavy Industries, Ltd.) type stirring blades, a glass lid, a stirrer with a stirring seal, a nitrogen inlet tube, a reflux condenser, and a temperature sensor was charged with 446.1 parts by mass of deionized water, 3.67 parts by mass of sodium hypophosphite monohydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.15 parts by mass of 48% sodium hydroxide aqueous solution. The solution in the reaction vessel was heated to 90°C while being stirred. Next, maintaining the temperature at 90°C, 223.7 parts by mass of N-vinylpyrrolidone were added in two stages: 120 minutes followed by 241.3 parts by mass over 150 minutes. 24.5 parts by mass of 2-isopropenyl-2-oxazoline were added over 300 minutes, starting 1 minute after the start of N-vinylpyrrolidone addition. 10% V-50 was added in two stages: 6.7 parts by mass over 30 minutes followed by 53.8 parts by mass over 330 minutes, each through separate supply channels. The 2-isopropenyl-2-oxazoline was added continuously at a constant dropping rate. After the completion of the 10% V-50 addition, the temperature was maintained at 90°C for another 60 minutes for aging to obtain the polymer composition. The solid content after polymerization was 50% by mass, and the N-vinylpyrrolidone and 2-isopropenyl-2-oxazoline content in the obtained copolymer (3) was 95% by mass and 5% by mass, respectively. The obtained polymer composition was dried under reduced pressure in a vacuum dryer at 90°C (Yamato Scientific Co., Ltd.: rectangular vacuum constant temperature dryer DP33) for 5 hours, and the dried material was then pulverized in a lab mill to obtain a powder containing the copolymer (3) of this disclosure. The solid content of the obtained powder was 95.1%, the K value was 27, and the weight-average molecular weight was 85,000. The content of unreacted hypophosphorous acid (sodium) in the powder was 400 ppm in terms of acid. The amount of phosphorus atoms present in the main chain of the copolymer was 2000 ppm.

[0097] <Comparative Example 1> In a SUS reaction vessel equipped with Maxblend (a registered trademark of Sumitomo Heavy Industries, Ltd.) type stirring blades, a glass lid, a stirrer with a stirring seal, a nitrogen inlet tube, a reflux condenser, and a temperature sensor, 373.9 parts by mass of deionized water, 9.0 parts by mass of 25% sodium hypophosphite monohydrate aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.14 parts by mass of 48% sodium hydroxide aqueous solution were charged, and the solution in the reaction vessel was heated to 88-92°C while stirring. Then, maintaining the temperature at 90°C, 500 parts by mass of N-vinylpyrrolidone was added dropwise over 360 minutes, and 27.0 parts by mass of 10% V-50 was added dropwise over 390 minutes, each through separate supply channels. The addition of each component was carried out continuously at a constant dropping rate. Furthermore, 8.5 parts by mass of 88% formic acid aqueous solution was added in a single batch 420 minutes after the start of polymerization, and 3.6 parts by mass of 48% sodium hydroxide aqueous solution was added in a single batch 480 minutes after the start of polymerization. After the addition of the 48% by mass sodium hydroxide aqueous solution, the mixture was aged for another 60 minutes while maintaining the temperature to obtain the polymer composition. The obtained polymer composition was dried under reduced pressure in a vacuum dryer at 90°C (Yamato Scientific Co., Ltd.: Rectangular vacuum constant temperature dryer DP33) for 5 hours, and then the dried material was pulverized in a lab mill to obtain a powder containing comparative polymer (1). The weight-average molecular weight of the obtained powder was 90,000. The content of unreacted hypophosphorous acid (sodium) in the powder was 15 ppm in terms of acid. The amount of phosphorus atoms present in the main chain of the copolymer was 1800 ppm.

[0098] <Comparative Example 2> In a glass reaction vessel equipped with a double-paddle type stirring blade, a glass lid, a stirrer with a stirring seal, a nitrogen inlet tube, a reflux condenser, and a temperature sensor, 1177.0 parts by mass of deionized water, 3.6 parts by mass of 4.8% sodium hydroxide aqueous solution, 116.6 parts by mass of N-vinylpyrrolidone as monomer solution, and 9.8 parts by mass of sodium hypophosphite monohydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were charged, and the mixture was heated to 90°C while stirring at 200 rpm under a nitrogen stream. Then, while maintaining the temperature at 90°C and stirring at 200 rpm under a nitrogen stream, 1049.7 parts by mass of N-vinylpyrrolidone was added dropwise over 230 minutes, 61.4 parts by mass of styrene (at 25°C, 10 g of styrene dissolved in 100 g of water resulted in 10 g of insoluble matter) over 240 minutes, and 81.8 parts by mass of 15% V-50 aqueous solution over 240 minutes, each through separate supply channels. Each component was added dropwise continuously at a constant dropping rate. After the addition of N-vinylpyrrolidone was completed, the mixture was aged for another 130 minutes while maintaining the temperature to obtain a polymer composition containing comparative polymer (2). The solid content concentration after polymerization was 50% by mass, and the N-vinylpyrrolidone and styrene content in the obtained comparative copolymer (2) were 95.0% by mass and 5.0% by mass, respectively. The obtained polymer composition was dried under reduced pressure in a vacuum dryer at 90°C (Yamato Scientific Co., Ltd.: rectangular vacuum constant temperature dryer DP33) for 5 hours, and the dried material was then pulverized in a lab mill to obtain a powder containing comparative copolymer (2). The weight-average molecular weight of the obtained powder was 19,000. The content of unreacted hypophosphorous acid (sodium) in the powder was 2200 ppm in acid terms. The amount of phosphorus atoms present in the main chain of the copolymer was 1800 ppm.

[0099] <Comparative Example 3> A glass reaction vessel equipped with a double-paddle type stirring blade, a glass lid, a stirrer with a stirring seal, a nitrogen inlet tube, a reflux condenser, and a temperature sensor was charged with 55 parts by mass of methyl ethyl ketone, 27 parts by mass of N-vinylpyrrolidone, and 3 parts by mass of 2-isopropenyl-2-oxazoline. A solution of 0.15 parts by mass of V-65 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) dissolved in 15 parts by mass of methyl ethyl ketone was charged into the dropping apparatus. The solution in the reaction vessel was then heated to 70°C while stirring at 200 rpm under a nitrogen stream. The temperature was then maintained at 70°C, and the above solution charged into the dropping apparatus was added dropwise over 180 minutes while stirring. After the dropwise addition was complete, the temperature was maintained for another 120 minutes to allow maturation, yielding a pale yellow polymer composition containing comparative copolymer (3). The solid content after polymerization was 50% by mass, and the N-vinylpyrrolidone and 2-isopropenyl-2-oxazoline content in comparative copolymer (3) was 80.0% by mass and 20.0% by mass, respectively. The obtained polymer composition was dried under reduced pressure in a vacuum dryer at 90°C (Yamato Scientific Co., Ltd.: rectangular vacuum constant temperature dryer DP33) for 5 hours, and the dried material was then pulverized in a lab mill to obtain the powder of comparative copolymer (3). The weight-average molecular weight of comparative copolymer (3) was 90,000.

[0100] <Evaluation of polymers based on heat resistance to yellowing (YI value)> The color tone was evaluated under high-temperature conditions using the following procedure. The copolymer of the present disclosure and the comparative (co)polymer were dried in a vacuum dryer at 50°C for 12 hours. After drying, each copolymer, comparative polymer, and comparative copolymer were heated at 260°C under a nitrogen atmosphere for 60 minutes, and then air-cooled in a desiccator. After the samples returned to room temperature were ground, L, a, and b were measured using a colorimeter under the following conditions. Equipment: “Color difference meter SE-2000” manufactured by Nippon Denshoku Kogyo Co., Ltd. Method: Samples before and after heating are placed in a quartz cell and measured in "reflection mode" under light shielding. From the obtained values ​​of L, a, and b, the degree of yellowness (YI) was calculated using the following formula.

[0101]

number

[0102] Judgment criteria: ○: YI value is less than 40 ×: YI value is 40 or higher

[0103] <Thermal decomposition resistance test of the polymer (thermal decomposition initiation temperature)> The thermal decomposition start temperatures of the copolymers of the present disclosure and the comparative (co)polymer powders were measured using a thermogravimetric analyzer (BRUKER TG-DTA2000SA). (Measurement conditions) Sample: 0.01g Atmosphere: Air (50L / min) Heating pattern: 2°C / min Judgment criteria: ○: Pyrolysis onset temperature is below 200℃ ×: The thermal decomposition initiation temperature is below 200°C.

[0104] <Evaluation of polyester resin compositions> The copolymer of the present disclosure and the comparative (co)polymer were pre-mixed with polyester resin (Unitika, MA-2101M) at a concentration of 5% by mass, and then kneaded at 270°C for 5 minutes using a mixer (Toyo Seiki Seisakusho, Laboplastmill) to obtain resin compositions (1) to (3) and comparative resin compositions (1) to (3). Furthermore, the obtained resin compositions (1) to (3) and comparative resin compositions (1) to (3) were melt-press molded at 10 MPa for 1 minute using a manual heating press (Imoto Seisakusho, IMC-180C) to produce unstretched films with a thickness of 100 μm. The moisture absorption rate and AFM of the obtained unstretched films were measured under the conditions described below.

[0105] <Compatibility test with polyester resin (evaluation of AFM images)> The unstretched film was further cross-sectional using a microtome, and the surface topography was evaluated by image processing under the following measurement conditions.

[0106] (Measurement conditions) Device: BRUKER Dimension icon Measurement mode: PeakForceTapping mode (Air) Probe: RTESPA-300 (Spring constant = 40 N / m) Judgment criteria: ○: No patchy pattern was observed in the elastic modulus image of the AFM image. ×: Spotted patterns are visible in the elastic modulus image of the AFM image.

[0107] <Hygroscopicity test of polyester resin composition> Test specimens obtained by cutting an unstretched film to a size of 20 mm x 60 mm are placed in an aluminum cup (tare weight W0 (g)) and dried in a dryer at 110°C for 2 hours. After that, the specimens are allowed to cool in a desiccator for 30 minutes, and the total weight W1 (g) including the specimens is measured. Next, the aluminum cup containing the specimens is placed in a constant temperature and humidity chamber adjusted to 20°C and 65% RH for 24 hours. After that, the specimens are allowed to cool in a desiccator for 30 minutes, and the total weight W2 (g) including the specimens is measured. Then, the aluminum cup containing the specimens is placed in a constant temperature and humidity chamber adjusted to 30°C and 90% RH for 24 hours. After that, the specimens are allowed to cool in a desiccator for 30 minutes, and the total weight W3 (g) including the specimens is measured.

number

[0108] ○:ΔMR≧1.0 ×: Resulting MR < 1.0

[0109] <Evaluation of polyamide resin compositions> The copolymer of the present disclosure and the comparative (co)polymer were pre-mixed in 15% by mass with a polyamide resin (Nylon 6, manufactured by Toray Industries, Inc., trade name: Amiran CM1017), and then kneaded at 240°C for 5 minutes using a mixer (Laboplastmill, manufactured by Toyo Seiki Seisakusho Co., Ltd.) to obtain a resin composition and a comparative resin composition. Furthermore, the obtained resin composition and comparative resin composition were melt-press molded at 10 MPa for 1 minute using a manual heating press (IMC-180C, manufactured by Imoto Seisakusho Co., Ltd.) to produce an unstretched film with a thickness of 100 μm.

[0110] <Hygroscopicity test of polyamide resin composition> The ΔMR was measured using the same method as in the hygroscopicity test for polyester resin compositions. The evaluation criteria were as follows. ○: ΔMR≧3.0 ×: ΔMR < 3.0

[0111] <Heat resistance test of polyamide resin composition> The unstretched film was further heated at 10 MPa and 300°C for 10 minutes using a manual heating press (Imoto Seisakusho, IMC-180C model), and the film condition was visually evaluated. ○: No foaming is observed, or very little foaming, on the film. ×: Foaming was observed in the film.

[0112] The evaluation results are summarized in Table 1.

[0113] [Table 1]

[0114] The abbreviations used in the table are as follows: NVP: N-vinylpyrrolidone IPO:2-Isopropenyl-2-Oxazoline St: Styrene The results in Table 1 show that the copolymer of this disclosure exhibits excellent yellowing resistance even under high-temperature conditions, excellent compatibility with fibers such as polyester, can impart good moisture absorption and release properties to fibers such as polyester, and also exhibits excellent thermal decomposition resistance, resulting in excellent moldability for resins.

Claims

1. It has a structural unit (a) derived from an N-vinyllactam monomer and a structural unit (b) derived from an oxazoline monomer, and a substituent containing a phosphorus atom. The content of the structural unit (b) is 1% by mass or more and 30% by mass or less, relative to 100% by mass of structural units derived from the total monomers. The substituent containing the phosphorus atom is a hypophosphorous (salt) group, An N-vinyl lactam copolymer in which the phosphorus atom content is 0.1 to 1.5% by mass per 100% by mass of the N-vinyl lactam copolymer.

2. With respect to 100% by mass of structural units derived from the total monomer of the N-vinyllactam copolymer, The content of structural unit (a) derived from the N-vinyllactam monomer is 70 to 97% by mass, The N-vinyllactam copolymer according to claim 1, wherein the content of structural unit (b) derived from the oxazoline monomer is 3 to 30% by mass.

3. The N-vinyl lactam copolymer according to claim 1 or claim 2, wherein the K value calculated by the following formula is 15 or more and 60 or less. K=(1.5logη ｒｅｌ -1) / (0.15+0.003c)+(300clogη ｒｅｌ +(c+1.5clogη ｒｅｌ ) ２ ) １／２ / (0.15c+0.003c ２ ) (η ｒｅｌ c is the relative viscosity (at 25°C) of an aqueous solution of N-vinyllactam copolymer relative to water, as measured by a capillary viscometer, and c is the concentration [mass%] of the N-vinyllactam copolymer in the aqueous solution.

4. An N-vinyl lactam copolymer according to claim 1 or claim 2, wherein the weight-average molecular weight is 10,000 or more and 500,000 or less.

5. A hygroscopic agent comprising an N-vinyl lactam copolymer as described in claim 1 or claim 2.

6. A compatibility agent comprising an N-vinyllactam copolymer as described in claim 1 or claim 2.

7. A resin composition comprising the N-vinyl lactam copolymer according to claim 1 or claim 2, and polyester and / or polyamide.

8. The process includes a step of polymerizing monomer components, including an oxazoline monomer and an N-vinyllactam monomer, in the presence of a phosphorus atom-containing compound. The content of the oxazoline monomer is 1% by mass or more and 30% by mass or less based on 100% by mass of the total monomers. The phosphorus atom-containing compound is hypophosphorous acid (salt), A method for producing an N-vinyl lactam copolymer, wherein the amount of the phosphorus atom-containing compound used is 0.1 g or more and 5 g or less per mole of monomer (total monomer) used.

Images