Ionomers, resin sheets, and laminated glass

Abstract

To provide an ionomer which is excellent in transparency, maintains high elastic modulus at high temperature, is reduced in coloration, and is reduced in odor in molding.SOLUTION: An ionomer contains, based on the total monomer unit constituting a resin, 0.05 to 1.0 mol% of a (meth)acrylate unit, 4.5 to 9.0 mol% of a carboxylic acid unit, 0.65 to 3.0 mol% of a carboxylic acid neutralized compound unit, and an ethylene unit, and has a total content of the (meth)acrylate unit, the carboxylic acid unit and the carboxylic acid neutralized compound unit of 7.0 to 10 mol%.

Description

[Technical Field]

[0001] The present invention relates to ionomers, and more specifically to ionomers having excellent physical and optical properties, resin sheets using the ionomer, and laminated glass using the resin sheet as an interlayer. [Background technology]

[0002] Ionomers, which are neutralized ethylene-unsaturated carboxylic acid copolymers, are used as interlayers in laminated glass due to their excellent transparency and adhesion to glass (for example, Patent Document 1). In recent years, the performance requirements for laminated glass have increased, and ionomers are now required to maintain high transparency regardless of the manufacturing conditions of the laminated glass, maintain a high modulus of elasticity even at high temperatures to prevent a decrease in the strength of the laminated glass, and have less coloration and a better appearance.

[0003] For example, Patent Document 2 describes an ionomer in which 5 to 15% by mass of an α,β-unsaturated carboxylic acid derivative is introduced as a third component into an ethylene-unsaturated carboxylic acid copolymer. This ionomer exhibits improved optical properties.

[0004] However, the ionomer described in Patent Document 2 still lacks sufficient properties to achieve the required balance of transparency, high modulus of elasticity, and low coloration for ionomers used as interlayers in laminated glass. Furthermore, a new problem with the ionomer described in Patent Document 2 is that a strong odor originating from the third component is generated during molding, placing a heavy burden on the workers. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] U.S. Patent No. 6,432,522 [Patent Document 2] Special Publication No. 2017-519083 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention solves the above-mentioned conventional problems, and its objective is to provide an ionomer that has excellent transparency, maintains a high modulus of elasticity at high temperatures, has minimal discoloration, and reduces odor during molding. [Means for solving the problem]

[0007] The present invention provides an ionomer containing 0.05 to 1.0 mol% (meth)acrylic acid ester units, 4.5 to 9.0 mol% carboxylic acid units, 0.65 to 3.0 mol% carboxylic acid neutralized product units, and ethylene units based on the total monomer units constituting the resin, and having a total content of 7.0 to 10 mol% of (meth)acrylic acid ester units, carboxylic acid units, and carboxylic acid neutralized product units.

[0008] In one embodiment, the ionomer has an MFR of 0.7 g / 10 min or more, measured under conditions of a measurement temperature of 190°C and a load of 2.16 kgf.

[0009] In one embodiment, the (meth)acrylic acid ester unit is at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate.

[0010] In one form, the above ionomer contains 6.5 to 10 mol% (meth)acrylic acid ester units, The MFR (Measuring Frequency) was measured under conditions of a measurement temperature of 190°C and a load of 2.16 kgf, with a range of 90-400 g / 10 min. This product uses ethylene-(meth)acrylic acid ester copolymer as a raw material.

[0011] In one form, the above ionomer is The storage modulus of elasticity of 30 MPa or higher was measured using a 0.8 mm thick resin sheet test piece under the conditions of a measurement temperature of 50°C and a frequency of 1 Hz. A yellow index (YI) of 2.0 or less was measured using a resin sheet-like test piece with a thickness of 0.8 mm, and A 0.8 mm thick resin sheet test specimen was placed between two glass plates, heated to 140°C, and then slowly cooled to 23°C at a rate of 0.1°C / min. The haze level of 5.0% or less was measured using this laminated glass. It possesses the following characteristics.

[0012] Furthermore, the present invention provides a resin composition containing any of the above ionomers in an amount of 93% by mass or more.

[0013] Furthermore, the present invention provides a resin sheet substantially made from any of the above-mentioned ionomers or resin compositions.

[0014] Furthermore, the present invention provides laminated glass having two glass plates and the above-mentioned resin sheet as an interlayer disposed between the two glass plates. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide an ionomer that exhibits a good balance of transparency, high modulus of elasticity, and low coloration, and in addition, has reduced odor during molding. [Modes for carrying out the invention]

[0016] <Structure> The ionomer of the present invention is a resin comprising ethylene units, (meth)acrylic acid ester units (A), carboxylic acid units (B), and carboxylic acid neutralized units (C). In one embodiment, the ionomer of the present invention is a resin comprising constituent units (A), (B), and (C) and ethylene units.

[0017] Examples of the monomer constituting the (meth)acrylic acid ester unit (A) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, pentadecyl (meth)acrylate, dodecyl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, allyl (meth)acrylate, etc. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate are preferred, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate are more preferred, methyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate are even more preferred, and methyl (meth)acrylate is most preferred. In the case of methacrylic acid ester and acrylic acid ester, methacrylic acid ester is preferred because it is superior in heat decomposition resistance and low coloring property. These (meth)acrylic acid esters can be used alone or in combination of two or more.

[0018] The content of the (meth)acrylate unit (A) in the ionomer is 0.05 mol% or more and 1.0 mol% or less. When the content of (A) is within this range, the transparency is increased and the odor during molding is reduced. The preferable lower limit of the above content is preferably 0.07 mol% or more, more preferably 0.08 mol% or more, and even more preferably 0.09 mol% or more. The preferable upper limit of the above content is preferably 0.9 mol% or less, more preferably 0.8 mol% or less, and even more preferably 0.6 mol% or less.

[0019] Examples of the monomer constituting the carboxylic acid unit (B) include acrylic acid, methacrylic acid, itaconic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, etc. Among these, acrylic acid, methacrylic acid, monomethyl maleate, and monoethyl maleate are more preferable, acrylic acid and methacrylic acid are even more preferable, and methacrylic acid is most preferable. These carboxylic acid units can be used alone or in combination of two or more.

[0020] The content of the carboxylic acid unit (B) in the ionomer is 4.5 mol% or more and 9.0 mol% or less. When the content of (B) is within this range, it is possible to achieve both adhesion to glass and transparency. If the above content is too low, the transparency will decrease and the adhesion to glass will also decrease. If the above content is too high, the moldability will decrease and there will be a tendency to color. The preferable lower limit of the above content is preferably 5.0 mol% or more, more preferably 5.5 mol% or more, and even more preferably 5.8 mol% or more. The preferable upper limit of the above content is preferably 8.5 mol% or less, more preferably 8.0 mol% or less, and even more preferably 7.5 mol% or less.

[0021] The carboxylic acid neutralized unit (C) is preferably the neutralized unit of the carboxylic acid unit (B). The carboxylic acid neutralized product is obtained by replacing the hydrogen ions of the carboxylic acid with metal ions. Examples of metal ions include monovalent metals such as lithium, sodium, and potassium, and polyvalent metals such as magnesium, calcium, zinc, aluminum, and titanium. There is no need to be only one type of metal ion; two or more types can be used in combination. For example, a combination of one or more monovalent metal ions and one or more divalent metal ions may be used.

[0022] The content of carboxylic acid neutralized units (C) in the ionomer is between 0.65 mol% and 3.0 mol%. This range of (C) content allows for both transparency and moldability. If the content is too high, the melt viscosity during molding increases, and discoloration tends to occur. If the content is too low, transparency is low, and the elastic modulus at 50°C becomes low. The preferred lower limit of the content is preferably 1.0 mol% or more, more preferably 1.5 mol% or more, and even more preferably 1.7 mol% or more. The preferred upper limit of the content is preferably 2.7 mol% or less, more preferably 2.6 mol% or less, and even more preferably 2.5 mol% or less.

[0023] The ionomer of the present invention has a total amount of (meth)acrylic acid ester units (A), carboxylic acid units (B), and carboxylic acid neutralized product units (C) of 7.0 mol% or more and 10 mol% or less. Having the total amount of (A), (B), and (C) within this range allows for both high transparency and a high modulus of elasticity at 50°C. The lower limit of the above content is more preferably 7.5 mol% or more, even more preferably 8.0 mol% or more, and most preferably 8.5 mol% or more. The upper limit of the above content is more preferably 9.9 mol% or less, and even more preferably 9.5 mol% or less.

[0024] <Manufacturing method> One method for producing the ionomer of the present invention is to copolymerize ethylene and (meth)acrylic acid ester at high temperature and high pressure to obtain an ethylene-(meth)acrylic acid ester copolymer (X), and then convert a portion of the (meth)acrylic acid ester units into (meth)acrylic acid units and (meth)acrylic acid neutralized unit units. One method for converting a portion of the (meth)acrylic acid ester units into (meth)acrylic acid units and (meth)acrylic acid neutralized unit units is, for example, to perform a saponification reaction using sodium hydroxide to synthesize an ethylene-(meth)acrylic acid ester-(meth)acrylic acid neutralized copolymer, and then convert a portion of the (meth)acrylic acid neutralized unit units into (meth)acrylic acid with an acid.

[0025] As the (meth)acrylic acid ester used as the raw material for the above manufacturing method, the aforementioned (meth)acrylic acid esters can be used. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred, and methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate are more preferred. Comparing methacrylic acid esters and acrylic acid esters, methacrylic acid esters are preferred because the resulting ionomer has superior heat resistance to decomposition and low coloration. These (meth)acrylic acid esters can be used individually or in combination of two or more.

[0026] Specific examples of ethylene-(meth)acrylic acid ester copolymer (X) include ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-n-propyl acrylate copolymer, ethylene-n-propyl methacrylate copolymer, ethylene-isopropyl acrylate copolymer, ethylene-isopropyl methacrylate copolymer, ethylene-n-butyl acrylate copolymer, ethylene-n-butyl methacrylate copolymer, ethylene-sec-butyl acrylate copolymer, ethylene-sec-butyl methacrylate copolymer, and the like. These copolymers may be commercially available or synthesized with reference to US2013 / 0274424, JP 2006-233059, and JP 2007-84743.

[0027] The (meth)acrylic acid ester unit content of the ethylene-(meth)acrylic acid ester copolymer (X) is preferably 6.5 mol% or more and 10 mol% or less, more preferably 7.0 mol% or more and 9.5 mol% or less, and most preferably 7.5 mol% or more and 9.2 mol% or less. By setting the content within this range, the content of (meth)acrylic acid ester units, carboxylic acid units, and carboxylic acid neutralized product units in the resulting ionomer can be set within an appropriate range.

[0028] The melt flow rate (MFR) of the ethylene-(meth)acrylic acid copolymer (X), measured at 190°C and 2.16 kgf, is preferably 90 g / 10 min or more and 400 g / 10 min or less, more preferably 100 g / 10 min or more and 350 g / 10 min or less, and most preferably 150 g / 10 min or more and 330 g / 10 min or less. By setting the MFR of the ethylene-(meth)acrylic acid copolymer (X) within this range, both the moldability and strength of the resulting ionomer can be achieved. The MFR of the ethylene-(meth)acrylic acid copolymer (X) can be adjusted by the degree of polymerization and the ratio of (meth)acrylic acid units.

[0029] Ethylene-(meth)acrylic acid ester copolymer (X) was subjected to a column temperature of 140°C, 1,2,4-trichlorobenzene solvent, and a column (TSKgel GMH). HR The molecular weight in polystyrene terms, measured using three series-bound H(20)HT lines, is preferably such that the lower limit of the weight-average molecular weight is 15,000 g / mol or more, more preferably 20,000 g / mol or more, even more preferably 25,000 g / mol or more, and particularly preferably 30,000 g / mol or more, from the viewpoint of achieving both the moldability and strength of the resulting ionomer. The upper limit of the weight-average molecular weight is preferably 200,000 g / mol or less, more preferably 100,000 g / mol or less, and even more preferably 50,000 g / mol or less. The lower limit of the number-average molecular weight is preferably 3,000 g / mol or more, more preferably 50,000 g / mol or more, even more preferably 80,000 g / mol or more, even more preferably 10,000 g / mol or more, and particularly preferably 15,000 g / mol or more. The upper limit of the number-average molecular weight is preferably 100,000 g / mol or less, more preferably 50,000 g / mol or less, and even more preferably 30,000 g / mol or less.

[0030] The degree of branching per 1000 carbon atoms of the ethylene-(meth)acrylic acid copolymer (X) is not particularly limited, but is preferably 5 to 30, and more preferably 6 to 20. The degree of branching per 1000 carbon atoms is analyzed by dissolving the ethylene-(meth)acrylic acid copolymer in deuterated orthodichlorobenzene, 13 This can be performed using the inverse gate decoupling method of 1C-NMR.

[0031] As a method for converting some of the (meth)acrylic acid ester units of an ethylene-(meth)acrylic acid ester copolymer (X) to (meth)acrylic acid units and (meth)acrylic acid neutralized units, some of the (meth)acrylic acid ester units of the ethylene-(meth)acrylic acid ester copolymer (X) are subjected to a saponification reaction with an alkali to convert them to (meth)acrylic acid neutralized units, and then some of the (meth)acrylic acid neutralized units are demetallated with an acid to convert them back to (meth)acrylic acid units. This allows for the production of an ionomer having ethylene units, (meth)acrylic acid ester units, carboxylic acid units, and carboxylic acid neutralized units.

[0032] Another method involves saponifying a portion of the (meth)acrylic acid ester units of the ethylene-(meth)acrylic acid ester copolymer (X) with an alkali to convert them into (meth)acrylic acid neutralized units. Then, all of the (meth)acrylic acid neutralized units are demetallated with an acid to convert them back into (meth)acrylic acid units. Finally, a portion of these units is neutralized with an alkali metal or alkaline earth metal to produce an ionomer having ethylene units, (meth)acrylic acid ester units, carboxylic acid units, and carboxylic acid neutralized units.

[0033] Suitable solvents for the saponification reaction of a portion of the (meth)acrylic acid ester units of the ethylene-(meth)acrylic acid ester copolymer (X) with an alkali include ether solvents such as tetrahydrofuran and dioxane, halides such as chloroform and dichlorobenzene, ketones with 6 or more carbon atoms such as methyl butyl ketone, hydrocarbon compounds such as n-hexane and cyclohexane, mixed solvents of hydrocarbon compounds and alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol, aromatic compounds such as benzene, toluene, xylene, and ethylbenzene, and mixed solvents of aromatic compounds and alcohols. Since the ethylene-(meth)acrylic acid ester copolymer (X) suitable for the present invention preferably contains (meth)acrylic acid ester units in a specific proportion, the selection of appropriate solvents and reaction conditions is important for producing the ionomer of the present invention.

[0034] When saponifying a portion of the (meth)acrylic acid ester units of the ethylene-(meth)acrylic acid ester copolymer (X) with an alkali, the temperature is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 70°C or higher, and most preferably 80°C or higher, from the viewpoint of reactivity and the solubility of the ethylene-(meth)acrylic acid ester copolymer (X). There is no particular upper limit, but a temperature at which the ethylene-(meth)acrylic acid ester copolymer (X) does not decompose is preferred, for example, 300°C or lower.

[0035] In the process of converting a portion of the (meth)acrylic acid ester units of the ethylene-(meth)acrylic acid copolymer (X) into (meth)acrylic acid neutralized units by saponification with an alkali, and then demetallating a portion of the (meth)acrylic acid neutralized units with an acid to convert them back into (meth)acrylic acid units, any known organic acid such as acetic acid, hydrochloric acid, nitric acid, or sulfuric acid can be used. The solvent used for demetallating with acid can be the same solvent used in the saponification reaction.

[0036] When a portion of the (meth)acrylic acid ester units of an ethylene-(meth)acrylic acid copolymer (X) is saponified with an alkali to convert them into (meth)acrylic acid neutralized units, and then all of the (meth)acrylic acid neutralized units are demetallated with an acid to convert them back into (meth)acrylic acid units, and then a portion of these units is neutralized with an alkali metal or alkaline earth metal, the neutralizing agent used is not particularly limited as long as it is an ionic compound containing the aforementioned metal ions. Examples of metal ions include alkali metal ions such as lithium, potassium, and sodium; alkaline earth metal ions such as magnesium and calcium; transition metal ions such as zinc, nickel, iron, and titanium; and aluminum ions. For example, when the metal ion is a sodium cation, examples of neutralizing agents include sodium hydroxide, sodium acetate, and sodium bicarbonate. Polymers such as ionomers containing sodium carboxylate units can also be used as neutralizing agents.

[0037] The content of (meth)acrylic acid ester units, carboxylic acid units, and carboxylic acid neutralized units in the ionomer of the present invention can be analyzed by the following procedure. First, the constituent units in the ionomer are identified by pyrolysis gas chromatography, and then their respective content can be evaluated using nuclear magnetic resonance spectroscopy (NMR) and elemental analysis. IR and Raman analysis can also be combined. Prior to these analyses, it is preferable to remove components other than the ionomer by reprecipitation or Soxhlet extraction.

[0038] The melting point of the ionomer of the present invention is preferably 50°C or higher and 200°C or lower, more preferably 60°C or higher and 180°C or lower, and even more preferably 80°C or higher and 150°C or lower. The melting point can be determined from the pick-top temperature of the melting peak during the second heating, using differential scanning calorimetry (DSC) with a cooling rate of -10°C / min and a heating rate of 10°C / min, referring to the method described in JIS K7121:2012.

[0039] The heat of fusion of the ionomer of the present invention is preferably 0 J / g or more and 25 J / g or less. It can be calculated using differential scanning calorimetry (DSC) with a cooling rate of -10°C / min and a heating rate of 10°C / min, based on the method described in JIS K7122:2012, from the area of ​​the melting peak during the second heating.

[0040] The melt flow rate (MFR) of the ionomer of the present invention, measured under conditions of 190°C and 2.16 kgf, is preferably 0.3 g / 10 min or higher, more preferably 0.7 g / 10 min or higher, even more preferably 1.0 g / 10 min or higher, even more preferably 1.5 g / 10 min or higher, and particularly preferably 2.0 g / 10 min or higher. While there is no particular upper limit, it is preferably 50 g / 10 min or lower, more preferably 30 g / 10 min or lower, even more preferably 10 g / 10 min or lower, and particularly preferably 5 g / 10 min or lower. Having the ionomer's MFR within this range enables molding processes that suppress thermal degradation. The ionomer's MFR can be adjusted by controlling the molecular weight and the amounts of (meth)acrylic acid ester units (A), carboxylic acid units (B), and carboxylic acid neutralized product units (C).

[0041] The molecular weight is measured by heating and dissolving the ionomer in a mixed solvent of acetic acid / toluene to convert the carboxylic acid neutralized units into carboxylic acid units. Furthermore, the carboxylic acid units are esterified to methyl carboxylate with trimethylsilyldiazomethane. The resulting copolymer is then dissolved in orthodichlorobenzene, and its molecular weight can be measured using high-temperature SEC. A calibration curve is created using polystyrene as a standard substance, and the molecular weight is calculated in terms of polystyrene.

[0042] The degree of branching per 1000 carbon atoms of the ionomer of the present invention is not particularly limited, but is preferably 5 to 30, and more preferably 6 to 20. The degree of branching per 1000 carbon atoms can be analyzed using the DDMAS method with solid-state NMR.

[0043] The storage modulus (E') at 50°C, as measured by the dynamic viscoelasticity measurement of the ionomer of the present invention, is preferably 20 MPa or higher, more preferably 30 MPa or higher, even more preferably 40 MPa or higher, and most preferably 50 MPa or higher. There is no particular upper limit to the storage modulus (E'), but it is preferably 1000 MPa or lower. In the present invention, the storage modulus (E') is measured by the method described in the examples.

[0044] <Resin composition> The ionomer of the present invention may optionally contain anti-aging agents, antioxidants, and thermal degradation inhibitors. The amounts of such additives can be appropriately determined within a range that does not impair the effects of the present invention, and the total amount is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less.

[0045] The resin composition preferably contains 93% by mass or more of the ionomer of the present invention, more preferably 95% by mass or more, and even more preferably 96% by mass or more.

[0046] Various additives may be added to the polymerization or polymer reaction system during the production of ionomers, added during the resin separation process, or added after separation. They may also be added during the production of molded articles such as films.

[0047] Known materials can be used as anti-aging agents. Specifically, phenolic compounds such as hydroquinone, hydroquinone monomethyl ether, 2,5-di-t-butylphenol, 2,6-di(t-butyl)-4-methylphenol, mono(or di, or tri)(α-methylbenzyl)phenol; bisphenolic compounds such as 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol); benzimidazole compounds such as 2-mercaptobenzimidazole and 2-mercaptomethylbenzimidazole; and 6-ethoxy-1 Amine-ketone compounds such as 2-dihydro-2,2,4-trimethylquinoline, reaction products of diphenylamine and acetone, and 2,2,4-trimethyl-1,2-dihydroquinoline polymers; aromatic secondary amine compounds such as N-phenyl-1-naphthylamine, alkylated diphenylamine, octylated diphenylamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, p-(p-toluenesulfonylamide)diphenylamine, and N,N'-diphenyl-p-phenylenediamine; and thiourea compounds such as 1,3-bis(dimethylaminopropyl)-2-thiourea and tributylthiourea can be used.

[0048] Antioxidants are those that, in the presence of oxygen, are effective in preventing oxidative degradation of resins on their own. Examples include phosphorus-based antioxidants, hindered phenol-based antioxidants, and thioether-based antioxidants. These antioxidants may be used individually or in combination of two or more. Among these, phosphorus-based antioxidants and hindered phenol-based antioxidants are preferred from the viewpoint of preventing degradation of optical properties due to coloring, and the combination of phosphorus-based antioxidants and hindered phenol-based antioxidants is more preferred.

[0049] When using a combination of phosphorus-based antioxidants and hindered phenol-based antioxidants, the ratio of phosphorus-based antioxidant to hindered phenol-based antioxidant by mass is preferably (1:5) to (2:1), and more preferably (1:2) to (1:1).

[0050] Preferred phosphorus-based antioxidants include 2,2-methylenebis(4,6-di-t-butylphenyl)octylphosphite (manufactured by ADEKA Corporation; product name: Adekastab HP-10), tris(2,4-di-t-butylphenyl)phosphite (manufactured by BASF; product name: IRGAFOS168), and 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (manufactured by ADEKA Corporation; product name: Adekastab PEP-36).

[0051] Preferred hindered phenol antioxidants include pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (BASF; trade name IRGANOX1010) and octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate (BASF; trade name IRGANOX1076).

[0052] Thermal degradation inhibitors prevent the thermal degradation of resins by capturing polymer radicals that are generated when exposed to high temperatures in virtually oxygen-free conditions.

[0053] Preferred thermal degradation inhibitors include 2-t-butyl-6-(3'-t-butyl-5'-methyl-hydroxybenzyl)-4-methylphenylacrylate (manufactured by Sumitomo Chemical Co., Ltd.; trade name Sumirizer GM) and 2,4-di-t-amyl-6-(3',5'-di-t-amyl-2'-hydroxy-α-methylbenzyl)phenylacrylate (manufactured by Sumitomo Chemical Co., Ltd.; trade name Sumirizer GS).

[0054] In the present invention, in addition to the anti-aging agents, antioxidants, and thermal degradation inhibitors mentioned above, various additives such as ultraviolet absorbers, light stabilizers, anti-adhesion agents, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, dyes and pigments, organic dyes, matting agents, and phosphors may be added to the ionomer as needed. The amount of such various additives can be appropriately determined within a range that does not impair the effects of the present invention, and the total amount is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less.

[0055] Various additives may be added to the polymerization or polymer reaction system during the production of ionomers, added during the resin separation process, or added after separation. They may also be added during the production of molded articles such as films.

[0056] UV absorbers are compounds that have the ability to absorb ultraviolet light and are said to primarily function by converting light energy into thermal energy.

[0057] Examples of UV absorbers include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalate anilides, malonic acid esters, and formamidines. These may be used individually or in combination of two or more.

[0058] Benzotriazoles are preferred as UV absorbers because they are highly effective in suppressing the deterioration of optical properties such as discoloration caused by UV exposure. Preferred benzotriazoles include 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (BASF; trade name TINUVIN329), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (BASF; trade name TINUVIN234), 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-t-octylphenol] (ADEKA Corporation; LA-31), and 2-(5-octylthio-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol.

[0059] Furthermore, examples of triazine-based UV absorbers include 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine (manufactured by ADEKA Corporation; LA-F70), its analogues such as hydroxyphenyltriazine-based UV absorbers (manufactured by BASF; TINUVIN477 and TINUVIN460), and 2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine.

[0060] Light stabilizers are compounds that are said to primarily function by capturing radicals generated by oxidation caused by light. Suitable light stabilizers include hindered amines, such as compounds with a 2,2,6,6-tetraalkylpiperidine skeleton.

[0061] Preferred anti-adhesion agents include fatty acid salts or esters, polyhydric alcohol esters, inorganic salts, inorganic oxides, and particulate resins. Specific examples include calcium stearate, calcium carbonate, calcium sulfate, magnesium sulfate, barium sulfate, silicon dioxide (manufactured by Evonik; trade name Aerosil), and particulate acrylic resins.

[0062] Examples of lubricants include stearic acid, behenic acid, stearamidic acid, methylenebisstearamide, hydroxystearate triglyceride, paraffin wax, ketone wax, octyl alcohol, and hydrogenated oils.

[0063] Examples of release agents include higher alcohols such as cetyl alcohol and stearyl alcohol; and glycerin higher fatty acid esters such as monoglyceride stearate and diglyceride stearate.

[0064] As a polymer processing aid, polymer particles having a particle size of 0.05 to 0.5 μm, which can usually be produced by emulsion polymerization, are used. These polymer particles may be single-layer particles consisting of a polymer with a single composition ratio and a single intrinsic viscosity, or they may be multilayer particles consisting of two or more polymers with different composition ratios or intrinsic viscosities. Among these, particles with a two-layer structure, having a polymer layer with a low intrinsic viscosity in the inner layer and a polymer layer with a high intrinsic viscosity of 5 dl / g or more in the outer layer, are preferred. The polymer processing aid preferably has an intrinsic viscosity of 3 to 6 dl / g. If the intrinsic viscosity is too low, the effect of improving moldability tends to be low. If the intrinsic viscosity is too high, it tends to lead to a decrease in the moldability of the copolymer.

[0065] As organic dyes, compounds that have the function of converting ultraviolet light into visible light are preferably used.

[0066] Examples of phosphors include fluorescent pigments, fluorescent dyes, fluorescent white dyes, fluorescent whitening agents, and fluorescent bleaching agents.

[0067] The ionomer and resin composition containing the ionomer of the present invention can be made into pellets or other forms to improve convenience during storage, transportation, or molding. When forming into pellets, this can be done by cutting strands obtained by melt extrusion. The resin temperature during melt extrusion is preferably 150°C or higher, and more preferably 170°C or higher. Furthermore, the resin temperature during extrusion is preferably 250°C or lower, and more preferably 230°C or lower. In this case, using the low-odor resin of the present invention can ensure the health of workers. The ionomer and resin composition containing the ionomer of the present invention are useful as interlayers for laminated glass.

[0068] <Resin sheet> The resin sheet of the present invention may consist only of a layer (x) containing the above-mentioned ionomer or resin composition, or it may be a multilayer film containing at least one layer (x). The multilayer film is not particularly limited, but examples include a two-layer film in which layer (x) and other layers are laminated, or a film in which other layers are arranged between two layers (x).

[0069] Other layers include layers containing known resins. Examples of such resins include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, polytetrafluoroethylene, acrylic resin, polyamide, polyacetal, polycarbonate, and among polyesters, polyethylene terephthalate, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, polyarylate, liquid crystal polymer, polyimide, thermoplastic elastomer, and the like. The other layers may also contain additives such as plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, antiblocking agents, pigments, dyes, heat-shielding materials (e.g., inorganic heat-shielding fine particles or organic heat-shielding materials having infrared absorption capabilities), and functional inorganic compounds, as needed.

[0070] The method for producing the resin sheet of the present invention is not particularly limited. For example, it can be obtained by uniformly kneading the ionomer of the present invention or a resin composition containing the ionomer of the present invention, and then forming it into a layer (x) by known film-forming methods such as extrusion, calendering, pressing, solution casting, melt casting, or inflation. The layer (x) may be used as a resin sheet on its own. If necessary, the layer (x) may be laminated with other layers by press molding or the like to form a laminated resin sheet, or the layer (x) and other layers may be molded by co-extrusion to form a laminated resin sheet.

[0071] Among known film-forming methods, the method of manufacturing a resin sheet using an extruder is particularly preferred. The resin temperature during extrusion is preferably 150°C or higher, and more preferably 170°C or higher. Furthermore, the resin temperature during extrusion is preferably 250°C or lower, and more preferably 230°C or lower. If the resin temperature is too high, the resin used will decompose, raising concerns about resin degradation. Conversely, if the temperature is too low, discharge from the extruder will be unstable, leading to mechanical problems. To efficiently remove volatile substances, it is preferable to remove them by reducing the pressure from the extruder's vent port. Even when volatile substances are efficiently removed, odors may be generated by the T-die, etc., potentially severely deteriorating the working environment. By using the ionomer of the present invention, film formation becomes possible without deteriorating the working environment during film formation.

[0072] Furthermore, it is preferable to form an uneven surface structure on the resin sheet of the present invention using conventionally known methods such as melt fractures or embossing. The shapes of the melt fractures and embossing can be those conventionally known. Forming an uneven surface structure on the resin sheet of the present invention is preferable because it provides excellent bubble release when heat-pressing the resin sheet with a substrate such as glass.

[0073] The lower limit of the thickness of the resin sheet of the present invention is, in order of preference (the first lower limit is preferred, and the last lower limit is most preferred), 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, and 0.75 mm. The upper limit is, in order of preference (the first upper limit is preferred, and the last upper limit is most preferred), 5 mm, 4 mm, 2 mm, 1.6 mm, 1.2 mm, 1.1 mm, 1 mm, and 0.79 mm. The thickness of the resin sheet is measured using conventionally known methods, such as contact or non-contact thickness gauges. The resin sheet may be in a rolled state or as individual sheets.

[0074] The resin sheet of the present invention has the morphology, storage modulus (E'), and haze described with respect to the molten kneaded resin composition of the present invention.

[0075] The resin sheet of the present invention is preferably colorless, with minimal coloration. When the film thickness is 0.8 mm, the YI value is preferably 2.0 or less, more preferably 1.8 or less, even more preferably 1.5 or less, and most preferably 1.0 or less. The lower limit is 0.

[0076] The resin sheet of the present invention preferably has a low water content. For example, the water content is preferably 1% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.02% by mass or less, and most preferably 0.01% by mass or less.

[0077] <Laminated glass> The resin sheet of the present invention is preferably used as an interlayer for laminated glass. In this case, the glass laminated with the interlayer, which is the resin sheet of the present invention, can be any inorganic glass, such as float glass, tempered glass, polished glass, patterned glass, wired glass, or heat-absorbing glass, or conventionally known organic glass such as polymethyl methacrylate or polycarbonate, without limitation. These can be colorless or colored. One type may be used, or two or more types may be used in combination. Furthermore, the thickness of the glass is preferably 100 mm or less.

[0078] The laminated glass of the present invention, which is made by sandwiching a resin sheet between two sheets of glass, can be manufactured by conventionally known methods. Examples include using a vacuum laminator, a vacuum bag, a vacuum ring, or a nip roll. Another method involves pre-pressing the glass using the above methods and then placing it in an autoclave for final bonding.

[0079] When using a vacuum laminator, for example, 1 × 10 -6 ~3×10 -2 Inorganic glass plates, interlayers, adhesive resin layers, and organic glass plates are laminated under reduced pressure of MPa at 60-200°C, particularly at 80-160°C. Methods using vacuum bags or vacuum rings are described, for example, in European Patent No. 1235683, with a capacity of approximately 2 × 10⁻⁶. -2 It is laminated under a pressure of MPa at a temperature of 100-160°C.

[0080] One manufacturing method using nip rolls involves degassing the interlayer film with a roll at a temperature below the flow initiation temperature, followed by compression at a temperature close to the flow initiation temperature. Specifically, this method involves heating the film to 30-70°C using an infrared heater, degassing it with a roll, then heating it again to 50-120°C before compression with a roll.

[0081] When the laminated glass is pressed using the method described above and then placed in an autoclave for further pressing, the operating conditions for the autoclave process are appropriately selected depending on the thickness and composition of the laminated glass, but it is preferable to process it at a pressure of 0.5 to 1.5 MPa and a temperature of 100 to 160°C for 0.5 to 3 hours.

[0082] The laminated glass of the present invention exhibits excellent transparency. For example, when the interlayer thickness is 0.8 mm, the haze of the laminated glass is preferably 1% or less, more preferably 0.8% or less, and even more preferably 0.5% or less. There is no specific lower limit, but it is 0.01%. In this invention, the haze is measured using a haze meter HZ-1 (manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7136:2000.

[0083] The laminated glass of the present invention is particularly preferably one that exhibits excellent transparency even after being heated to 140°C and then slowly cooled from 140°C to 23°C at a rate of 0.1°C / min. For example, for laminated glass with an interlayer thickness of 0.8 mm, the haze after slow cooling is preferably 5.0% or less, more preferably 4.5% or less, even more preferably 4.0% or less, and most preferably 3.0% or less. There is no particular lower limit, but it is 0.01%.

[0084] The laminated glass of the present invention is preferably colorless, with minimal discoloration. For example, for laminated glass with an interlayer thickness of 0.8 mm, the YI is preferably 2.0 or less, more preferably 1.8 or less, even more preferably 1.5 or less, and most preferably 1.0 or less. The lower limit is 0.

[0085] The adhesive strength between the glass and the interlayer in the laminated glass of the present invention is preferably high. For example, the value evaluated by the compression shear strength test described in WO1999-058334 is preferably 15 MPa or higher, more preferably 20 MPa or higher, and most preferably 25 MPa or higher. There is no upper limit, but it is 100 MPa or lower.

[0086] As described above, the ionomer of the present invention and the resin sheet obtained by molding the ionomer of the present invention are useful as interlayers for laminated glass. These interlayers for laminated glass are particularly preferred as interlayers for structural laminated glass due to their excellent adhesion to substrates such as glass, transparency, and self-supporting properties. Furthermore, they are not limited to interlayers for structural laminated glass, but are also suitable as interlayers for various applications such as automotive windshields, automotive side windows, automotive sunroofs, automotive rear windows, head-up display glass, and other mobile bodies such as automobiles, laminates for exterior walls and roofs, panels, doors, windows, walls, roofs, sunroofs, soundproof walls, display windows, balconies, railing walls and other building materials, partition glass members for conference rooms, and solar cells, but are not limited to these applications. [Examples]

[0087] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0088] [Analysis of resins obtained in the examples and comparative examples] The content of (meth)acrylic acid ester units, carboxylic acid units, and carboxylic acid neutralized product units was analyzed as follows.

[0089] The ionomer or resin composition containing the ionomer obtained by the method described later was dissolved in a mixed solvent of dehydrated toluene / dehydrated acetic acid (75 / 25% by mass), reacted at 100°C for 2 hours, and then reprecipitated in a mixed solvent of acetone / water (80 / 20% by mass) to convert the carboxylic acid neutralized product back into a carboxylic acid. The obtained resin was thoroughly washed with water and then dried. The polymer unit components of the obtained resin were analyzed by thermal decomposition GC-MS (1). Next, the acid value of the obtained resin was measured in accordance with JIS K0070-1992 (2). The obtained resin was also subjected to a mixed solvent of deuterated toluene and deuterated methanol. 1¹H-NMR (400 MHz, JEOL Ltd.) measurements were performed (3). In addition, after pretreatment of the ionomer or resin composition containing the ionomer with microwave decomposition using nitric acid, the type and amount of metal ions in the carboxylic acid neutralized product were identified by ICP emission spectrometry (Thermo Fisher Scientific iCAP6500Duo) (4). From (1), the type and structure of the (meth)acrylic acid ester unit and the carboxylic acid unit were identified, and based on this information, the ratio of ethylene / (meth)acrylic acid ester unit / (total of carboxylic acid unit and carboxylic acid neutralized product unit) was calculated from the information in (2) and (3). Furthermore, the ratio of ethylene / (meth)acrylic acid ester unit / carboxylic acid unit / carboxylic acid neutralized product unit was calculated from the information in (4).

[0090] [Melt Flow Rate (MFR)] In accordance with JIS K7210, the amount of resin extruded per 10 minutes from a die of a specified diameter installed at the bottom of a cylinder was measured under conditions of 190°C and a 2.16 kgf load.

[0091] [Odor] 50 g of ionomer or ionomer-containing resin composition obtained by the method described later was melt-kneaded in a Laboplast Mill (manufactured by Toyo Seiki) at 220°C and 100 rpm. The inlet of the Laboplast Mill was left open, and the odor was compared from a distance of 50 mm directly above it. The odor was measured for 30 seconds starting 5 minutes after the start of melt-kneading using a portable odor sensor (model: XP-329m, manufactured by Shin-Cosmos Electric Co., Ltd.), and the average of the maximum and minimum odor values ​​over 30 seconds was compared. A higher odor value indicates a stronger odor, and odor values ​​of 700 or higher were evaluated as "B," while values ​​below 700 were evaluated as "A."

[0092] [Independent in high temperature environment] The molten kneaded ionomer or resin composition containing an ionomer obtained by the method described later was heated at 210°C at a rate of 50 kgf / cm². 2It was compression-molded at the pressure of for 5 minutes to obtain a resin sheet with a thickness of 0.8 mm. A test piece with a length of 40 mm and a width of 5 mm was cut out from the sheet, and the storage modulus of elasticity (E’) was measured using a dynamic viscoelasticity measuring device manufactured by UBM Co., Ltd. under the conditions of a measurement temperature of 50 °C and a frequency of 1 Hz. The value was used as an index for the self-supporting property of the resin sheet in a high-temperature environment. When the above storage modulus of elasticity was 30 MPa or more, it was evaluated as "A", and when it was less than 30 MPa, it was evaluated as "B".

[0093] [Colorability] The melt-kneaded product of an ionomer or a resin composition containing an ionomer obtained by the method described below was compression-molded at the pressure of under heating at 210 °C for 5 minutes to obtain a resin sheet with a thickness of 0.8 mm. The sheet was measured using a color difference meter "ZE-2000" (trade name) manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with JIS Z8722. The yellowness index (YI) calculated in accordance with JIS K7373 based on the obtained value was used. When the measured YI was 2.0 or less, it was evaluated as "A", when it exceeded 2.0 and was less than 3.0, it was evaluated as "B", and when it was 3.0 or more, it was evaluated as "C".

[0094] [Transparency] The melt-kneaded product of an ionomer or a resin composition containing an ionomer obtained by the method described below was compression-molded at the pressure of under heating at 210 °C for 5 minutes to obtain a resin sheet with a thickness of 0.8 mm. The obtained resin sheet was sandwiched between two sheets of float glass with a thickness of 2.7 mm, and using a vacuum laminator (1522N manufactured by Nisshinbo Mechatronics Co., Ltd.), the inside of the vacuum laminator was depressurized at 100 °C for 1 minute, and then pressed at a pressure of 30 kPa for 5 minutes while maintaining the degree of decompression and temperature to obtain a temporary adherent. The obtained temporary adherent was put into an autoclave and treated at 140 °C and 1.2 MPa for 30 minutes to obtain a laminated glass.

[0095] ​​​​The laminated glass obtained by the method described above was heated to 140°C and then slowly cooled to 23°C at a rate of 0.1°C / min. The haze of the laminated glass after the slow cooling operation was measured using a haze meter HZ-1 (manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7136:2000. The measured haze was evaluated as follows: "A" if it was 5.0% or less, "B" if it was between 5.0% and less than 10%, and "C" if it was 10% or more.

[0096] Table 1 summarizes the ethylene-(meth)acrylic acid copolymers (X) used as raw materials for producing the ionomers of this example and comparative example. These ethylene-(meth)acrylic acid copolymers (X) can be synthesized by the high-temperature, high-pressure radical polymerization method described in US2013 / 0274424, JP 2006-233059, or JP 2007-84743. For example, "Aclift" (registered trademark) WD301F manufactured by Sumitomo Chemical Co., Ltd. can be used as EMMA1, and "Rexpearl" (registered trademark) A4250 manufactured by Nippon Polyethylene Co., Ltd. can be used as EEA1.

[0097] [Table 1]

[0098] [Example 1] 100 parts by mass of EMMA4 shown in Table 1 were mixed with 233 parts by mass of toluene and dissolved at 60°C under a pressure of 0.02 MPa. 96 parts by mass of a methanol solution of sodium hydroxide (20% by mass) was added to the resulting solution, and the methyl methacrylate units were saponified at 100°C for 2 hours to convert them to sodium methacrylate units.

[0099] To this solution, 44 parts by mass of concentrated hydrochloric acid (36% by mass) was added, and some of the sodium methacrylate units were converted to methacrylic acid at 100°C for 2 hours. The resulting solution was reprecipitation in a mixed solvent of acetone / water (80% / 20% by mass) to obtain ionomer 1. Next, the obtained ionomer 1 was analyzed and its properties were evaluated. The analytical results of ionomer 1 are shown in Table 2. The MFR measurement results and odor evaluation results of ionomer 1, the self-supporting properties of the resin sheet at high temperatures, and the transparency and colorability evaluation results of the laminated glass are shown in Table 3.

[0100] [Example 2] Ionomer 2 was obtained in the same manner as in Example 1, except that EMMA5 shown in Table 1 was used, and 100 parts by mass of a methanol solution of sodium hydroxide and 46 parts by mass of concentrated hydrochloric acid were added. The analytical and evaluation results of the obtained ionomer 2 are shown in Tables 2 and 3.

[0101] [Example 3] Ionomer 3 was obtained in the same manner as in Example 1, except that EMMA5 shown in Table 1 was used, 95 parts by mass of a methanol solution of sodium hydroxide (16% by mass) was added, and methyl methacrylate units were saponified at 100°C for 10 hours, and 33 parts by mass of concentrated hydrochloric acid was added. The analytical and evaluation results of the obtained ionomer 3 are shown in Tables 2 and 3.

[0102] [Example 4] Ionomer 4 was obtained in the same manner as in Example 1, except that EMMA6 shown in Table 1 was used, and 112 parts by mass of a methanol solution of sodium hydroxide and 51 parts by mass of concentrated hydrochloric acid were added. The analytical and evaluation results of the obtained ionomer 4 are shown in Tables 2 and 3.

[0103] [Example 5] Ionomer 5 was obtained in the same manner as in Example 1, except that 100 parts by mass of a methanol solution of sodium hydroxide and 43 parts by mass of concentrated hydrochloric acid were added to EEA2 shown in Table 1. The analytical and evaluation results of the obtained ionomer 5 are shown in Tables 2 and 3.

[0104] [Example 6] Ionomer 6 was obtained in the same manner as in Example 1, except that 100 parts by mass of a methanol solution of sodium hydroxide and 46 parts by mass of concentrated hydrochloric acid were added to EEA1 shown in Table 1. The analytical and evaluation results of the obtained ionomer 6 are shown in Tables 2 and 3.

[0105] [Example 7] Ionomer 7 was obtained in the same manner as in Example 1, except that 112 parts by mass of a methanol solution of sodium hydroxide and 51 parts by mass of concentrated hydrochloric acid were added using the EMA shown in Table 1. The analytical and evaluation results of the obtained ionomer 7 are shown in Tables 2 and 3.

[0106] [Example 8] Ionomer 18 was obtained in the same manner as in Example 1, except that EMMA7 shown in Table 1 was used, and 100 parts by mass of a methanol solution of sodium hydroxide and 46 parts by mass of concentrated hydrochloric acid were added. The analytical and evaluation results of the obtained ionomer 18 are shown in Tables 2 and 3.

[0107] [Comparative Example 1] Ionomer 8 was obtained in the same manner as in Example 1, except that EMMA1 shown in Table 1 was used, and 40 parts by mass of a methanol solution of sodium hydroxide and 18 parts by mass of concentrated hydrochloric acid were added. The analytical and evaluation results of the obtained ionomer 8 are shown in Tables 2 and 3.

[0108] [Comparative Example 2] Ionomer 9 was obtained in the same manner as in Example 1, except that 72 parts by mass of a methanol solution of sodium hydroxide and 33 parts by mass of concentrated hydrochloric acid were added to EMMA2 as shown in Table 1. The analytical and evaluation results of the obtained ionomer 9 are shown in Tables 2 and 3.

[0109] [Comparative Example 3] Ionomer 10 was obtained in the same manner as in Example 1, except that 80 parts by mass of a methanol solution of sodium hydroxide and 37 parts by mass of concentrated hydrochloric acid were added to EMMA3 shown in Table 1. The analytical and evaluation results of the obtained ionomer 10 are shown in Tables 2 and 3.

[0110] [Comparative Example 4] Ionomer 11 was obtained in the same manner as in Example 1, using EMMA4 as shown in Table 1, except that concentrated hydrochloric acid was not added, and 78 parts by mass of acetic acid was added. The analytical and evaluation results of the obtained ionomer 11 are shown in Tables 2 and 3.

[0111] [Comparative Example 5] Ionomer 12 was obtained in the same manner as in Example 1, except that 100 parts by mass of a methanol solution of sodium hydroxide was added to EMMA5 shown in Table 1, and the methyl methacrylate units were saponified at 120°C for 10 hours, and 46 parts by mass of concentrated hydrochloric acid was added. The analytical and evaluation results of the obtained ionomer 12 are shown in Tables 2 and 3.

[0112] [Comparative Example 6] Ionomer 13 was obtained in the same manner as in Example 3, except that EMMA5 shown in Table 1 was used, the saponification reaction time was set to 3 hours, and 39 parts by mass of concentrated hydrochloric acid were added. The analytical and evaluation results of the obtained ionomer 13 are shown in Tables 2 and 3.

[0113] [Comparative Example 7] Ionomer 14 was obtained in the same manner as in Example 4, except that 47 parts by mass of concentrated hydrochloric acid was added using EMMA6 as shown in Table 1. The analytical and evaluation results of the obtained ionomer 14 are shown in Tables 2 and 3.

[0114] [Comparative Example 8] Ionomer 15 was obtained in the same manner as in Example 1, except that 106 parts by mass of a methanol solution of sodium hydroxide, a saponification reaction time of 3 hours, and 49 parts by mass of concentrated hydrochloric acid were added using the EMA shown in Table 1. The analytical and evaluation results of the obtained ionomer 15 are shown in Tables 2 and 3.

[0115] [Comparative Example 9] An ethylene / methacrylate ionomer with a methacrylic acid unit content of 6.3 mol% and a sodium methacrylate unit content of 1.8 mol%, and an MFR of 2.7 g / 10 min, was used as ionomer 16. The analytical and evaluation results of ionomer 16 are shown in Tables 2 and 3.

[0116] [Comparative Example 10] Ionomer 17 was an ethylene / n-butyl methacrylate / methacrylate ionomer with a methacrylic acid unit content of 6.0 mol%, a sodium methacrylate unit content of 2.1 mol%, and a n-butyl methacrylate unit content of 3.0 mol%, and an MFR of 3.5 g / 10 min. The analytical and evaluation results of ionomer 17 are shown in Tables 2 and 3.

[0117] [Table 2]

[0118] [Table 3]

[0119] From the above results, the ionomer of the embodiment that satisfies all the specified constituent elements of the present invention exhibited excellent balance of transparency, high modulus of elasticity, and low coloration, and in addition, reduced odor during molding. In contrast, the ionomer of the comparative example that did not satisfy any of the constituent elements was inferior in one or more of the following performance aspects: transparency, high modulus of elasticity, low coloration, and odor.

Claims

1. The resin contains 0.05 to 0.9 mol% (meth)acrylic acid ester units, 4.5 to 8.95 mol% carboxylic acid units, 1.0 to 2.5 mol% carboxylic acid neutralized product units, and ethylene units, based on the total monomer units constituting the resin, and the total content of (meth)acrylic acid ester units, carboxylic acid units, and carboxylic acid neutralized product units is 7.0 to 10.0 mol%. The aforementioned carboxylic acid neutralized unit is a neutralized monovalent metal ion. It is an ionomer, MFR of 1.0 g / 10 min or more, measured under conditions of a measurement temperature of 190°C and a load of 2.16 kgf. The storage modulus of elasticity of 30 MPa or higher was measured using a 0.8 mm thick resin sheet test piece under the conditions of a measurement temperature of 50°C and a frequency of 1 Hz. A yellow index (YI) of 2.0 or less was measured using a resin sheet-like test piece with a thickness of 0.8 mm, and The haze level of 5.0% or less was measured using laminated glass, which was prepared by placing a 0.8 mm thick resin sheet test specimen between two glass plates, heating it to 140°C, and then slowly cooling it to 23°C at a rate of 0.1°C / min. An ionomer having the properties of an ionomer.

2. The ionomer according to claim 1, wherein the (meth)acrylic acid ester unit is methyl (meth)acrylic acid.

3. It contains 6.5 to 10 mol% (meth)acrylic acid ester units, The MFR (Mean Frequency Rate) was measured under conditions of a measurement temperature of 190°C and a load of 2.16 kgf, and had a range of 90 to 400 g / 10 min. Using ethylene-(meth)acrylic acid ester copolymer as a raw material, The ionomer according to claim 1 or 2.

4. A resin composition containing the ionomer described in any one of claims 1 to 3 in an amount of 93% by mass or more.

5. A resin sheet comprising an ionomer according to any one of claims 1 to 3, or a resin composition according to claim 4.

6. Laminated glass comprising two glass plates and a resin sheet as described in claim 5 as an interlayer disposed between the two glass plates.

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