Ionomer resin composition, resin sheet, and laminated glass

Abstract

The present invention relates to an ionomer resin composition comprising an ionomer resin and a silane coupling agent, wherein: the ionomer resin includes a (meth)acrylic acid unit (A), a (meth)acrylic acid neutralized unit (B), and an ethylene unit (C); the total content of the unit (A) and the unit (B) is 6-10 mol% with respect to the total monomer units constituting the ionomer resin; the content of a salt formed by a strong acid and a strong base in the ionomer resin composition is 1-400 mg / kg; and the content of the silane coupling agent is 0.005-0.5 parts by mass with respect to 100 parts by mass of the ionomer resin.

Description

[Technical Field]

[0001] This patent application claims priority under the Paris Convention with respect to Japanese Patent Application No. 2021-104273 (filing date: June 23, 2021), which is incorporated herein by reference in its entirety. The present invention relates to an ionomer resin composition, a resin sheet comprising one or more layers containing the ionomer resin composition, a laminated glass interlayer made of the resin sheet, and laminated glass having the laminated glass 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 ionomer resins 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 without reducing the strength of the laminated glass, have less coloration and a better appearance, and have better adhesion to glass and be less prone to peeling.

[0003] Patent Document 2 describes an ionomer which is a neutralization product of an ethylene acid copolymer containing a copolymer unit of ethylene, a copolymer unit of a primary α,β-unsaturated carboxylic acid having 3 to 10 carbon atoms, and a copolymer unit of a derivative of a secondary α,β-unsaturated carboxylic acid having 3 to 10 carbon atoms.

[0004] Patent Document 3 describes a resin composition containing a homogeneous mixture of an ionomer resin and a dialkoxysilane compound as an adhesion promoter. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] U.S. Patent No. 6,432,522 [Patent Document 2] Special Publication No. 2017-519083 [Patent Document 3] Special Publication No. 2020-529500 [Overview of the project] [Problems that the invention aims to solve]

[0006] Patent Document 2 states that the ionomer described in the document exhibits improved optical properties (haze) compared to conventional ionomers. However, our own investigations have shown that ionomers like the one described in Patent Document 2 are prone to thermal decomposition during molding and the resulting interlayer film is likely to have defects such as black foreign matter.

[0007] Furthermore, when laminated glass is used outdoors, moisture such as rain can cause delamination between the glass and the interlayer, particularly at the edges of the laminated glass, or whitening and a decrease in transparency. Therefore, there is a need for an ionomer resin that can form a laminated glass interlayer with high transparency and adhesion to the glass even in wet conditions.

[0008] Patent Document 3 describes that the resin composition described in the document has improved adhesion to glass in a wet state. However, according to the inventors' studies, the resin composition described in Patent Document 3 may have defects such as black foreign matter in the resulting interlayer film due to thermal decomposition during molding, and a crosslinked gel may be formed due to a crosslinking reaction with a dialkoxysilane compound during molding. Therefore, further improvements are needed to obtain an interlayer film with a good appearance.

[0009] Therefore, the object of the present invention is to provide an ionomer resin composition that exhibits excellent transparency, thermal decomposition resistance, and adhesion to substrates such as glass in a wet state. [Means for solving the problem]

[0010] The present inventors, after diligent research to solve the above problems, arrived at the present invention. That is, the present invention provides the following preferred embodiments.

[0011] [1] An ionomer resin composition comprising an ionomer resin and a silane coupling agent, The ionomer resin contains (meth)acrylic acid units (A), (meth)acrylic acid neutralized product units (B), and ethylene units (C), the total content of units (A) and (B) is 6 to 10 mol% based on the total monomer units constituting the ionomer resin, and the content of salts consisting of strong acids and strong bases in the ionomer resin is 1 to 400 mg / kg. An ionomer resin composition in which the silane coupling agent is contained in an amount of 0.005 to 0.5 parts by mass per 100 parts by mass of the ionomer resin. [2] The ionomer resin composition according to [1], wherein the ionomer resin further comprises (meth)acrylic acid ester units (D), and the total content of units (A), (B), and (D) is 6 to 10 mol% based on the total monomer units constituting the ionomer resin. [3] The ionomer resin composition according to [1] or [2], wherein the salt comprising the strong acid and the strong base is a metal salt of an alkali metal and / or an alkaline earth metal. [4] The ionomer resin composition according to any one of [1] to [3], wherein the salt comprising the strong acid and the strong base is a salt comprising at least one cation selected from the group consisting of sodium ions and potassium ions and at least one anion selected from the group consisting of halogen ions, nitrate ions and sulfate ions. [5] The ionomer resin composition according to any one of [1] to [4], wherein the silane coupling agent is at least one silane coupling agent selected from the group consisting of amino compounds, glycidoxy compounds, sulfide compounds, mercapto compounds, vinyl compounds, nitro compounds and chloro compounds. [6] The ionomer resin composition according to any one of [1] to [5], wherein the silane coupling agent is at least one silane coupling agent selected from the group consisting of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane. [7] A resin sheet comprising one or more layers containing the ionomer resin composition according to any one of [1] to [6]. [8] An interlayer film for laminated glass, which is formed of the resin sheet according to [7]. [9] A laminated glass comprising two glass plates and the interlayer film for laminated glass according to [8] disposed between the two glass plates.

Effect of the Invention

[0012] According to the present invention, there can be provided an ionomer resin composition excellent in transparency, thermal decomposition resistance and adhesion to substrates such as glass in a wet state.

Mode for Carrying Out the Invention

[0013] [Ionomer Resin Composition] The ionomer resin composition of the present invention comprises: an ionomer resin containing 1 to 400 mg / kg of a salt formed of a strong acid and a strong base; and 0.005 to 0.5 parts by mass of a silane coupling agent relative to 100 parts by mass of the ionomer resin, wherein the ionomer resin contains (meth)acrylic acid units (A), neutralized (meth)acrylic acid units (B), and ethylene units (C), and the total content of the units (A) and the units (B) is 6 to 10 mol% based on all monomer units constituting the ionomer resin. The present inventors have conducted studies on ionomer resin compositions, and surprisingly found that when an ionomer resin which contains specific units in specific amounts and contains 1 to 400 mg / kg of a salt formed of a strong acid and a strong base is combined with 0.005 to 0.5 parts by mass of a silane coupling agent relative to 100 parts by mass of said ionomer resin, an ionomer resin composition excellent in transparency, thermal decomposition resistance and adhesion to substrates such as glass in a wet state can be obtained.

[0014] In this specification, "unit" means "derived constituent unit," for example, (meth)acrylic acid unit refers to a constituent unit derived from (meth)acrylic acid, (meth)acrylic acid neutralized unit refers to a constituent unit derived from (meth)acrylic acid neutralized product, and ethylene unit refers to a constituent unit derived from ethylene. Also in this specification, "(meth)acrylic acid" refers to methacrylic acid or acrylic acid.

[0015] [Ionomer resin] The ionomer resin of the present invention contains (meth)acrylic acid units (A), (meth)acrylic acid neutralized product units (B), and ethylene units (C), wherein the total content of units (A) and (B) is 6 to 10 mol% based on the total monomer units constituting the ionomer resin. By having the total content within the above range, transparency and adhesion to substrates such as glass can be improved.

[0016] If the total content exceeds the upper limit, it becomes difficult to suppress the increase in melt viscosity during molding of the ionomer resin composition, which tends to reduce the moldability of the ionomer resin composition. Furthermore, if the total content is below the lower limit, the transparency of the ionomer resin composition, especially the transparency when the crystallization of the ionomer resin composition is promoted by slow cooling (hereinafter also referred to as transparency during slow cooling), tends to decrease. From the viewpoint of easily improving the transparency of the ionomer resin composition (especially transparency during slow cooling) and adhesion to substrates such as glass, the total content is 6 mol% or more, preferably 6.5 mol% or more, more preferably 7.0 mol% or more, and even more preferably 7.5 mol% or more. From the viewpoint of easily improving moldability, it is 10 mol% or less, preferably 9.9 mol% or less, and more preferably 9.5 mol% or less.

[0017] The total content of the aforementioned units (A) and (B) can be adjusted by the method for producing the ionomer resin. More specifically, when producing an ionomer resin using an ethylene-(meth)acrylic acid copolymer as a raw material and including a saponification reaction step for the copolymer, the total content can be adjusted by the degree of reactivity (conversion ratio) of each reaction that converts the (meth)acrylic acid units in the ethylene-(meth)acrylic acid copolymer into (meth)acrylic acid units (A) and (meth)acrylic acid neutralized product units (B) by the saponification reaction and the demetallation reaction.

[0018] <(meth)acrylic acid units (A)> Examples of monomers constituting (meth)acrylic acid unit (A) include acrylic acid and methacrylic acid, with methacrylic acid being preferred from the viewpoint of heat resistance and adhesion to the substrate. These (meth)acrylic acid units may be one type or a combination of two types.

[0019] The content of (meth)acrylic acid unit (A) in the ionomer resin is not particularly limited as long as the total content of unit (A) and unit (B) is within the range of 6 to 10 mol% based on the total monomer units constituting the ionomer resin. In one embodiment of the present invention, the content of (meth)acrylic acid unit (A) in the ionomer resin is preferably 4.5 mol% or more, more preferably 5.0 mol% or more, even more preferably 5.5 mol% or more, particularly preferably 5.8 mol% or more, and also preferably 9.0 mol% or less, more preferably 8.5 mol% or less, even more preferably 8.0 mol% or less, particularly preferably 7.5 mol% or less, based on the total monomer units constituting the ionomer resin. When the content of unit (A) is above the lower limit, the transparency and adhesion to the substrate of the ionomer resin composition are easily improved. When it is below the upper limit, the moldability is easily improved.

[0020] <(meth)acrylic acid neutralized product unit (B)> The neutralized (meth)acrylic acid unit (B) is preferably the neutralized unit of the (meth)acrylic acid unit (A). The (meth)acrylic acid neutralized product is obtained by replacing the hydrogen ions of (meth)acrylic acid with metal ions. Examples of the metal ions include monovalent metals such as lithium, sodium, and potassium, and polyvalent metals such as magnesium, calcium, zinc, aluminum, and titanium. Such metal ions may be used individually or in combination of two or more. For example, a combination of one or more monovalent metal ions and one or more divalent metal ions may be used.

[0021] The content of (meth)acrylic acid neutralized units (B) in the ionomer resin is not particularly limited as long as the total content of units (A) and units (B) is within the range of 6 to 10 mol% based on the total monomer units constituting the ionomer resin. In one embodiment of the present invention, the content of (meth)acrylic acid neutralized units (B) is preferably 0.65 mol% or more, more preferably 1.0 mol% or more, even more preferably 1.3 mol% or more, even more preferably 1.5 mol% or more, particularly preferably 1.6 mol% or more, and also preferably 3.0 mol% or less, more preferably 2.7 mol% or less, even more preferably 2.6 mol% or less, particularly preferably 2.5 mol% or less, based on the total monomer units constituting the ionomer resin. If the content of unit (B) is above the lower limit, transparency and elastic modulus are easily improved, and if it is below the upper limit, the increase in melt viscosity during molding is easily suppressed.

[0022] The content of each of the aforementioned units (A) and (B) can be adjusted by the degree of reactivity in each reaction that converts the (meth)acrylic acid units in the ethylene-(meth)acrylic acid copolymer into (meth)acrylic acid units (A) and (meth)acrylic acid neutralized units (B) by the saponification and demetallation reactions, when an ionomer resin is produced using an ethylene-(meth)acrylic acid copolymer as a raw material and the method includes a saponification reaction step and a demetallation reaction step for the copolymer.

[0023] <Ethylene unit (C)> The ethylene unit (C) content is preferably 80 mol% or more, more preferably 85 mol% or more, and even more preferably 88 mol% or more, based on the total monomer units constituting the ionomer resin, from the viewpoint of easily improving the impact resistance of the ionomer resin composition. Furthermore, from the viewpoint of easily improving the transparency of the ionomer resin composition (especially transparency during slow cooling), it is preferably 94 mol% or less, and more preferably 91 mol% or less. When the ethylene unit (C) content is above the lower limit, it is easy to improve mechanical strength and moldability, and when it is below the upper limit, it is easy to improve transparency.

[0024] <(meth)acrylate unit (D)> In one embodiment of the present invention, the ionomer resin preferably contains (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), as well as (meth)acrylic acid ester units (D) from the viewpoint of obtaining higher transparency.

[0025] When the ionomer resin contains (meth)acrylic acid ester units (D), the total content of units (A), (B), and (D) is preferably 6 to 10 mol% based on the total monomer units constituting the ionomer resin, from the viewpoint of easily improving transparency (especially transparency during slow cooling). That is, in a preferred embodiment of the present invention, the ionomer resin contains (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), ethylene units (C), and (meth)acrylic acid ester units (D), and the total content of units (A), (B), and (D) is preferably 6 to 10 mol% based on the total monomer units constituting the ionomer resin. When the ionomer resin contains (meth)acrylic acid ester units (D), if the total content of units (A), (B), and (D) is less than or equal to the upper limit, it is easier to suppress the increase in melt viscosity during molding of the ionomer resin composition, thereby improving the moldability of the ionomer resin composition. Furthermore, if the total content is above the lower limit, it is easier to improve the transparency of the ionomer resin composition, especially during slow cooling. When the ionomer resin contains (meth)acrylic acid ester units (D), the total content of units (A), (B), and (D) is 6 mol% or more, preferably 6.5 mol% or more, more preferably 7.0 mol% or more, and even more preferably 7.5 mol% or more, from the viewpoint of improving transparency (especially transparency during slow cooling) and adhesion to the substrate, and 10 mol% or less, preferably 9.9 mol% or less, and more preferably 9.5 mol% or less, from the viewpoint of moldability.

[0026] The total content of units (A), (B), and (D) can be adjusted by the raw materials of the ionomer resin. More specifically, when an ionomer resin is produced using an ethylene-(meth)acrylic acid copolymer as a raw material and a method including a saponification reaction step of the copolymer, the total content can be adjusted by the amount of (meth)acrylic acid ester modification of the ethylene-(meth)acrylic acid copolymer, which is the raw material of the ionomer resin. Also, as described in U.S. Patent No. 8399096, when an ionomer resin is produced using ethylene and (meth)acrylic acid as raw materials and polymerized, the total content can be adjusted by the ratio of ethylene to (meth)acrylic acid copolymerized.

[0027] Examples of monomers constituting the (meth)acrylate ester unit (D) 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, and allyl (meth)acrylate. Of these, preferred monomers from the viewpoint of transparency or heat resistance are 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 t-butyl (meth)acrylate; more preferred monomers are methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate; even more preferred monomers are methyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate; and particularly preferred monomer is methyl (meth)acrylate. These (meth)acrylate esters may be used individually or in combination of two or more.

[0028] When the ionomer resin contains (meth)acrylic acid ester units (D), the content of (meth)acrylic acid ester units (D) in the ionomer resin is not particularly limited. In one embodiment of the present invention, the content of (meth)acrylic acid ester units (D) in the ionomer resin is preferably more than 0 mol%, more preferably 0.01 mol% or more, even more preferably 0.05 mol% or more, particularly preferably 0.08 mol% or more, and also preferably 1.0 mol% or less, more preferably 0.7 mol% or less, and even more preferably 0.5 mol% or less, based on the total monomer units constituting the ionomer resin. When the content of units (D) is above the lower limit and below the upper limit, the transparency of the ionomer resin composition is easily improved.

[0029] When an ionomer resin contains (meth)acrylic acid ester units (D), the content of these units (D) can be adjusted by the degree of reactivity of the saponification reaction, which converts the (meth)acrylic acid ester units (D) in the ethylene-(meth)acrylic acid ester copolymer into (meth)acrylic acid units (A), when the ionomer resin is produced using an ethylene-(meth)acrylic acid ester copolymer as a raw material and the method includes a saponification reaction step and a demetallation reaction step for the copolymer.

[0030] <Other monomeric units> The ionomer resin of the present invention may contain monomer units other than (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), and optionally (meth)acrylic acid ester units (D). Examples of other monomer units include carboxylic acid units other than (meth)acrylic acid units (A1) and carboxylic acid neutralized units other than (meth)acrylic acid neutralized units (B1). Examples of monomers constituting the carboxylic acid unit (A1) include itaconic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, and the like, with monomethyl maleate and monoethyl maleate being preferred. Examples of monomers constituting the carboxylic acid neutralized product unit (B1) include the neutralized product unit of the carboxylic acid unit (A1). The carboxylic acid neutralized product is obtained by replacing the hydrogen ions of the carboxylic acid with metal ions. The metal ions are the same as those used in the (meth)acrylic acid neutralized product unit (B) described above, and the metal ions may be a single type or a combination of two or more types. These other monomeric units may be a single type or a combination of two or more types.

[0031] If the ionomer resin contains the above-mentioned other monomer units, the total content thereof, for example, the total content of (A1) and (B1), can be appropriately selected within a range that does not impair the effects of the present invention. For example, based on the total monomer units constituting the ionomer resin, it is preferably 5 mol% or less, more preferably 3 mol% or less, even more preferably 1 mol% or less, and also preferably 0.01 mol% or more, more preferably 0.1 mol% or more.

[0032] The content of (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), as well as (meth)acrylic acid ester units (D) if present, and other monomer units (e.g., units (A1) and (B1)) in the ionomer resin can be determined by first identifying the monomer units in the ionomer resin by pyrolysis gas chromatography, and then by using nuclear magnetic resonance spectroscopy (NMR) and elemental analysis. More specifically, it can be determined by the method described in the examples. Alternatively, it can be determined by combining the above analytical methods with IR and / or Raman analysis. It is preferable to remove components other than the ionomer resin by reprecipitation or Soxhlet extraction before these analyses.

[0033] <Salts composed of strong acids and strong bases> The ionomer resin contains 1 to 400 mg / kg of salts (hereinafter also simply referred to as "salts") consisting of strong acids and strong bases. The inventors have found that when the ionomer resin contains 1 to 400 mg / kg of salts, it is possible to improve the thermal decomposition resistance while maintaining the high transparency of the ionomer resin composition (especially transparency when water is absorbed). Therefore, the ionomer resin composition of the present invention can achieve both high transparency and high thermal decomposition resistance. The reason why the ionomer resin composition of the present invention has excellent thermal decomposition resistance due to the inclusion of salts within the above range is not clear, but it is thought that the interaction between the salts and (meth)acrylic acid units (A) in the ionomer resin suppresses the detachment of (meth)acrylic acid units (A) in the ionomer resin due to heat.

[0034] Furthermore, the inventors discovered that while combining ionomer resins with silane coupling agents typically tends to generate black foreign matter and crosslinked gels during molding, making it difficult to obtain resin sheets with a good appearance, surprisingly, when the ionomer resin contains 1 to 400 mg / kg of salt, it is easier to obtain resin sheets with a good appearance. Although the reason is not entirely clear, it is thought that the inclusion of salt improves the heat decomposition resistance of the ionomer resin composition.

[0035] If the salt content exceeds the upper limit, the transparency of the ionomer resin composition tends to decrease. If it is below the lower limit, the thermal decomposition resistance decreases, making the ionomer resin composition more susceptible to thermal decomposition, for example, during molding. From the viewpoint of easily improving thermal decomposition resistance and improving the appearance of the resulting resin sheet, the salt content is 1 mg / kg or more, preferably 3 mg / kg or more, and more preferably 5 mg / kg or more. Furthermore, from the viewpoint of easily improving transparency (especially transparency when water is absorbed) and improving the appearance of the resulting resin sheet, it is 400 mg / kg or less, preferably 380 mg / kg or less, more preferably 350 mg / kg or less, even more preferably 320 mg / kg or less, even more preferably 300 mg / kg or less, and particularly preferably 200 mg / kg or less. The salt content in the ionomer resin can be appropriately selected depending on the method of incorporating the salt into the ionomer resin, as described later. The salt content in the ionomer resin can be measured using an ion chromatograph, for example, by the method described in the examples.

[0036] The salts composed of a strong acid and a strong base are not particularly limited, and examples include metal salts of alkali metals and / or alkaline earth metals composed of a strong acid and a strong base. These salts may be used individually or in combination of two or more. Examples of alkali metal salts include lithium salts, sodium salts, potassium salts, rubidium salts, cesium salts, etc. From the viewpoint of easily improving the heat decomposition resistance of the ionomer resin composition and obtaining a resin sheet with a good appearance, preferred alkali metal salts are lithium salts, sodium salts, potassium salts, more preferably sodium salts and potassium salts, and even more preferably sodium salts. Examples of alkaline earth metal salts include beryllium salts, magnesium salts, calcium salts, strontium salts, barium salts, etc. From the viewpoint of easily improving the heat decomposition resistance of the ionomer resin composition, preferred alkaline earth metal salts are magnesium salts and calcium salts.

[0037] From the viewpoint of easily improving the heat decomposition resistance of the ionomer resin composition and easily obtaining a resin sheet with a good appearance, a more preferred salt is a salt comprising at least one cation selected from the group consisting of sodium ions, potassium ions, magnesium ions, and calcium ions, and at least one anion selected from the group consisting of halogen ions, sulfate ions, nitrate ions, and sulfonate ions, and even more preferably a salt comprising at least one cation selected from the group consisting of sodium ions and potassium ions, and at least one anion selected from the group consisting of halogen ions, sulfate ions, and nitrate ions.

[0038] Specific examples of preferred salts include sodium chloride, potassium chloride, magnesium chloride, calcium chloride, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, sodium nitrate, potassium nitrate, magnesium nitrate, calcium nitrate, sodium p-toluenesulfonate, potassium p-toluenesulfonate, magnesium p-toluenesulfonate, and calcium p-toluenesulfonate. From the viewpoint of easily improving transparency and heat decomposition resistance and obtaining resin sheets with a good appearance, more preferred salts are sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, sodium nitrate, potassium nitrate, and even more preferably sodium chloride, sodium sulfate, and sodium nitrate.

[0039] The method for incorporating salt into the ionomer resin is not particularly limited. Examples include (I) a method of generating and incorporating the salt during the manufacturing process of the ionomer resin, (II) a method of adding the salt separately during the manufacturing process of the ionomer resin, and (III) a method of manufacturing a salt-free ionomer resin and then adding the salt to the resin afterward. Of these methods, method (I), which involves generating and incorporating the salt during the manufacturing process of the ionomer resin, is preferred from the viewpoint of easily dispersing the salt uniformly in the ionomer resin, thereby improving transparency and heat decomposition resistance.

[0040] The method for adjusting the salt content consisting of strong acids and strong bases in the ionomer resin can be appropriately selected according to the salt content method described above. For example, when salt is included by method (I), it can be adjusted by the degree of cleanliness of the obtained resin. More specifically, the salt content in the ionomer resin can be adjusted by the number of washes in the process of washing the obtained resin with a washing solution. Examples of the washing solution include solvents that are good solvents for salt and poor solvents for resin, such as water, alcohols such as methanol, ketones such as acetone, and mixed solvents thereof. When salt is included by methods (II) and (III), the salt content in the ionomer resin can be adjusted by the amount of salt added separately and the amount of salt added later, respectively.

[0041] The dispersion state of the salts consisting of strong acids and strong bases in the ionomer resin is not particularly limited, but it is preferable that they be uniformly dispersed in the ionomer resin from the viewpoint of improving transparency and thermal degradation resistance and obtaining resin sheets with a good appearance.

[0042] In one embodiment of the present invention, the degree of branching per 1000 carbon atoms of the ionomer resin is not particularly limited, but is preferably 5 to 30, more preferably 6 to 20. The degree of branching can be adjusted by the polymerization temperature of the ionomer resin; for example, when the ionomer resin is synthesized by the EMMA saponification method, by the polymerization temperature when synthesizing ethylene-(meth)acrylic acid ester (X). The degree of branching per 1000 carbon atoms can be measured by the DDMAS method using solid-state NMR.

[0043] In one embodiment of the present invention, the melting point of the ionomer resin is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 80°C or higher, from the viewpoint of heat resistance and resistance to thermal decomposition, and is preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 150°C or lower, from the viewpoint of easily achieving adhesion with glass when manufacturing laminated glass. The melting point can be measured in accordance with JIS K7121:2012. Specifically, it can be measured using a differential scanning calorimeter (DSC) under conditions of a cooling rate of -10°C / min and a heating rate of 10°C / min, and determined from the pick-top temperature of the melting peak during the second heating.

[0044] In one embodiment of the present invention, the heat of fusion of the ionomer resin is preferably 0 J / g or more and 25 J / g or less. The heat of fusion can be measured in accordance with JIS K7122:2012. Specifically, it can be measured using a differential scanning calorimeter (DSC) under conditions of a cooling rate of -10°C / min and a heating rate of 10°C / min, and calculated from the area of ​​the melting peak during the second heating.

[0045] In one embodiment of the present invention, the melt flow rate (MFR) of the ionomer resin, measured in accordance with JIS K7210-1:2014 under conditions of 190°C and 2.16 kg, is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, even more preferably 0.7 g / 10 min or more, even more preferably 1.0 g / 10 min or more, particularly preferably 1.5 g / 10 min or more, preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, and particularly preferably 10 g / 10 min or less. When the MFR is above the lower limit and below the upper limit, it is easier to perform molding processes that suppress thermal degradation and to obtain a resin sheet with excellent puncture resistance.

[0046] The melting point, heat of fusion, and MFR of the ionomer resin can be adjusted by the molecular weight of the ionomer resin, as well as the content of (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), and optionally (meth)acrylic acid ester units (D) in the ionomer resin.

[0047] <Method for manufacturing ionomer resin> The method for producing the ionomer resin in the present invention is not particularly limited. For example, as described above for the method of incorporating a salt into the ionomer resin, it may be produced by (I) generating the salt during the ionomer resin production process, (II) adding the salt separately during the ionomer resin production process, or (III) first producing an ionomer resin without salt and then adding the salt to the resin afterward. Of these methods, method (I), which involves generating and incorporating the salt during the ionomer resin production process, is preferred from the viewpoint of easily dispersing the salt, which consists of a strong acid and a strong base, uniformly in the ionomer resin, thereby improving the transparency and heat decomposition resistance of the ionomer resin composition. Method (I) will be described in detail below.

[0048] Method (I) includes a process in which an ethylene-(meth)acrylic acid ester copolymer (X) is used as a raw material, and all or part of the (meth)acrylic acid ester units in the copolymer are converted into (meth)acrylic acid units and (meth)acrylic acid neutralized unit to produce a crude ionomer resin containing (meth)acrylic acid units (A), (meth)acrylic acid neutralized unit (B), ethylene units (C), and optionally (meth)acrylic acid ester units (D) (step i), a poor solvent is added to a solution of the obtained crude ionomer resin to precipitate granular resin (step ii), and the precipitated granular resin is then washed with a washing solution (step iii).

[0049] (Process i) A method for converting all or part of the (meth)acrylic acid ester units in an ethylene-(meth)acrylic acid ester copolymer (X) to (meth)acrylic acid units and (meth)acrylic acid neutralized units is to saponify the ethylene-(meth)acrylic acid ester copolymer (X) with a strong base to convert all or part of the (meth)acrylic acid ester units to (meth)acrylic acid neutralized units to obtain an ethylene-(meth)acrylic acid neutralized copolymer or an ethylene-(meth)acrylic acid ester-(meth)acrylic acid neutralized copolymer, and then demetallate a portion of the (meth)acrylic acid neutralized units in the obtained copolymer with a strong acid to convert them to (meth)acrylic acid units (hereinafter also referred to as method (1)). Other than method (1) described above, there is a method (hereinafter also referred to as method (2)) in which all (meth)acrylic acid neutralized units in the ethylene-(meth)acrylic acid neutralized copolymer or ethylene-(meth)acrylic acid ester-(meth)acrylic acid neutralized copolymer obtained by saponification in method (1) are demetallated with a strong acid to convert them into (meth)acrylic acid units to obtain ethylene-(meth)acrylic acid copolymer or ethylene-(meth)acrylic acid ester-(meth)acrylic acid copolymer, and then a portion of the (meth)acrylic acid units in the obtained copolymer are neutralized with metal ions. In addition, in methods (1) and (2) above, a salt consisting of a strong acid and a strong base is produced by the neutralization reaction between the strong base used in the saponification reaction and the strong acid used in the demetallation reaction, and a crude ionomer resin containing the salt consisting of a strong acid and a strong base is obtained.

[0050] Examples of monomers constituting the (meth)acrylic acid ester unit of the above ethylene-(meth)acrylic acid ester copolymer (X) 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, and allyl (meth)acrylate. Of these, preferred monomers are 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 t-butyl (meth)acrylate. More preferred monomers are methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate. Even more preferred monomers are methyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate. Particularly preferred is methyl (meth)acrylate. These (meth)acrylate esters may be used individually or in combination of two or more.

[0051] 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, and ethylene-sec-butyl methacrylate copolymer. These copolymers may be commercially available products, or they may be synthesized by the high-temperature, high-pressure radical polymerization method described in US2013 / 0274424, JP 2006-233059, or JP 2007-84743. Examples of such commercially available products include "Aclift" (registered trademark) WD301F and WH401F manufactured by Sumitomo Chemical Co., Ltd., and "Rexpearl" (registered trademark) A4250 manufactured by Nippon Polyethylene Co., Ltd.

[0052] The content of (meth)acrylic acid ester units in the ethylene-(meth)acrylic acid ester copolymer (X) is preferably 6 mol% or more, more preferably 6.5 mol% or more, even more preferably 7 mol% or more, particularly preferably 7.5 mol% or more, and also preferably 10 mol% or less, more preferably 9.9 mol% or less, and even more preferably 9.5 mol% or less. The content of (meth)acrylic acid ester units in copolymer (X) corresponds to the total content of (meth)acrylic acid units (A), (meth)acrylic acid neutralized product units (B), and (meth)acrylic acid ester units (D), if present, in the resulting crude ionomer resin and ionomer resin. Therefore, if the content of (meth)acrylic acid ester units in copolymer (X) is above the lower limit, the transparency of the resulting ionomer resin composition, especially transparency during slow cooling, is easily improved, and if the content is below the upper limit, the moldability of the resulting ionomer resin composition is easily improved. The content of (meth)acrylic acid ester units in copolymer (X) can be adjusted by the copolymerization ratio of ethylene to (meth)acrylic acid ester. The content can be determined by pyrolysis gas chromatography, nuclear magnetic resonance spectroscopy (NMR), and elemental analysis, similar to the content of (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), as well as (meth)acrylic acid ester units (D) if present, and other monomer units (e.g., units (A1) and (B1)) in the ionomer resin described above.

[0053] In one embodiment of the present invention, the melt flow rate (MFR) of the ethylene-(meth)acrylic acid copolymer (X), measured in accordance with JIS K7210-1:2014 at 190°C and 2.16 kg, is preferably 5 g / 10 min or more, more preferably 10 g / 10 min or more, even more preferably 50 g / 10 min or more, even more preferably 100 g / 10 min or more, preferably 400 g / 10 min or less, more preferably 350 g / 10 min or less, even more preferably 300 g / 10 min or less, and even more preferably 250 g / 10 min or less. When the MFR of the ethylene-(meth)acrylic acid copolymer (X) is above the lower limit and below the upper limit, the moldability and strength of the resulting ionomer resin composition are easily improved. The MFR of the ethylene-(meth)acrylic acid copolymer (X) can be adjusted by the degree of polymerization and the content of (meth)acrylic acid units. The MFR can be measured, for example, by the method described in the examples.

[0054] The weight-average molecular weight of the ethylene-(meth)acrylic acid copolymer (X) is preferably 15,000 g / mol or more, more preferably 20,000 g / mol or more, even more preferably 30,000 g / mol or more, preferably 200,000 g / mol or less, and more preferably 100,000 g / mol or less, from the viewpoint of easily improving the moldability and strength of the resulting ionomer resin composition. Similarly, the number-average molecular weight of the ethylene-(meth)acrylic acid copolymer (X) is preferably 5,000 g / mol or more, more preferably 10,000 g / mol or more, even more preferably 15,000 g / mol or more, preferably 100,000 g / mol or less, and more preferably 50,000 g / mol or less. The weight-average molecular weight and number-average molecular weight can be adjusted by the amount of polymerization initiator and / or chain transfer agent used during polymerization. The molecular weights (weight-average molecular weight and number-average molecular weight) of these ethylene-(meth)acrylic acid ester copolymers (X) were determined using a column (TSKgel GMH). HR Using three -H(20)HT series-connected columns and 1,2,4-trichlorobenzene solvent, the measurement can be performed in polystyrene equivalent under conditions of a column temperature of 140°C.

[0055] 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, more preferably 6 to 20. The degree of branching can be adjusted by the polymerization temperature when polymerizing the copolymer (X). The degree of branching is determined by dissolving the ethylene-(meth)acrylic acid copolymer (X) in deuterated orthodichlorobenzene, 13 It can be measured by the inverse gate decoupling method of 1C-NMR.

[0056] Examples of alkalis used in the saponification reaction in methods (1) and (2) above include strong bases such as sodium hydroxide, potassium hydroxide, and calcium hydroxide. From the viewpoint of solubility in the solvent used in the saponification reaction and economic efficiency, sodium hydroxide and potassium hydroxide are preferred.

[0057] Examples of solvents used in the above saponification reaction include ethers such as tetrahydrofuran and dioxane; halogen-containing solvents such as chloroform and dichlorobenzene; ketones with 6 or more carbon atoms such as methyl butyl ketone; 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. These solvents may be used individually or in combination of two or more. Of these, from the viewpoint of the solubility of the resin before and after the saponification reaction, preferred solvents are mixed solvents of hydrocarbon compounds and alcohols, and mixed solvents of aromatic compounds and alcohols, and more preferred solvents are mixed solvents of aromatic compounds such as toluene and alcohols such as methanol. The ratio of hydrocarbon compounds or aromatic compounds to alcohols in the mixed solvent can be appropriately selected depending on the type of solvent used. For example, the mass ratio of hydrocarbon compounds or aromatic compounds to alcohols (hydrocarbon compounds or aromatic compounds / alcohols) may be 50 / 50 to 90 / 10.

[0058] The temperature at which the above saponification reaction is carried out is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 70°C or higher, and particularly preferably 80°C or higher, from the viewpoint of reactivity and the solubility of the ethylene-(meth)acrylic acid copolymer (X). The upper limit of this temperature is not particularly limited as long as it is below the temperature at which the ethylene-(meth)acrylic acid copolymer (X) decomposes, for example, 300°C or lower.

[0059] The above saponification reaction may be carried out in air or in an inert gas such as nitrogen gas or argon gas. Furthermore, the above saponification reaction may be carried out under normal pressure, under pressure, or under reduced pressure, and is preferably carried out under pressure.

[0060] Examples of acids used for demetallation in methods (1) and (2) above include strong acids such as hydrochloric acid, nitric acid, sulfuric acid, and toluenesulfonic acid. These acids may be used individually or in combination of two or more. From the viewpoint of easily removing salts from the ionomer resin after demetallation, inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid are preferred. The solvent used for the above demetallation can be the same solvent used in the saponification reaction described above.

[0061] The temperature used when performing the above demetallation is preferably 20°C or higher, more preferably 30°C or higher, even more preferably 40°C or higher, preferably 100°C or lower, more preferably 80°C or lower, and even more preferably 60°C or lower, from the viewpoint of easily lowering the viscosity of the reaction solution.

[0062] The above demetallation may be carried out in air or in an inert gas such as nitrogen or argon, similar to the saponification reaction. Furthermore, the saponification reaction may be carried out under normal pressure, under pressure, or under reduced pressure, and is preferably carried out under pressure.

[0063] In method (2) described above, the neutralizing agent used to neutralize a portion of the (meth)acrylic acid units and convert them into (meth)acrylic acid neutralized units is not particularly limited as long as it is an ionic compound containing a metal ion. Examples of the 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 ion, an example of a neutralizing agent is sodium hydroxide.

[0064] (Step ii) (Solution of crude ionomer resin) The crude ionomer resin obtained in step i contains (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), and the total content of units (A) and (B) is 6 to 10 mol% based on the total monomer units constituting the crude ionomer resin. Furthermore, it is preferable that the crude ionomer resin contains (meth)acrylic acid ester units (D) in addition to units (A), (B), and (C), and if the crude ionomer resin contains (meth)acrylic acid ester units (D), it is preferable that the total content of units (A), (B), and (D) is 6 to 10 mol% based on the total monomer units constituting the crude ionomer resin. Furthermore, the crude ionomer resin may also contain other monomer units, such as carboxylic acid units other than (meth)acrylic acid units (A1), carboxylic acid neutralized units other than (meth)acrylic acid neutralized units (B1), in addition to the aforementioned units (A), (B), and (C), and optionally, (D).

[0065] Examples of the units (A) and (B) in the crude ionomer resin, as well as the unit (D) which may be optionally included, and other monomer units (A1) and (B1), include the same units as those described above for units (A), unit (B), unit (D), unit (A1), and unit (B1) contained in the ionomer resin of the present invention, and the preferred form is also the same as that of the ionomer resin described above. Furthermore, the content of each unit in the crude ionomer resin, the total content of unit (A) and unit (B), and the total content of unit (A), unit (B), and unit (D) when unit (D) is optionally included, are also the same as those described above for the ionomer resin of the present invention, including the preferred form.

[0066] A solution of crude ionomer resin can be prepared by dissolving the crude ionomer resin obtained in step i in a solvent, and the reaction solution of the crude ionomer resin obtained in step i may be used as the solution of crude ionomer resin.

[0067] The solvent in the solution of the crude ionomer resin is not particularly limited as long as it is capable of dissolving the crude ionomer resin, and examples include solvents similar to those used in the saponification reaction described above. Among these, a mixed solvent of an aromatic compound such as toluene and an alcohol such as methanol is preferred from the viewpoint of solubility of the crude ionomer resin. The ratio of the aromatic compound to the alcohol in the mixed solvent can be appropriately selected depending on the type of solvent used, for example, the mass ratio of the aromatic compound to the alcohol (aromatic compound / alcohol) may be 50 / 50 to 90 / 10, preferably 65 / 35 to 85 / 15.

[0068] The concentration of the crude ionomer resin solution is preferably 30% by mass or less, more preferably 15% by mass or less, and also preferably 1% by mass or more, more preferably 5% by mass or more, from the viewpoint of easily obtaining granular resin with small particle size, thereby easily adjusting the salt content in the ionomer resin within the range of 1 to 400 mg / kg, and easily improving the heat decomposition resistance of the ionomer resin.

[0069] The temperature of the crude ionomer resin solution is preferably below the melting point of the ionomer resin, more preferably below 60°C, and even more preferably below 50°C, from the viewpoint of easily suppressing the aggregation or adhesion of precipitated granular resin, easily adjusting the salt content in the ionomer resin to within the range of 1 to 400 mg / kg, and easily improving the heat decomposition resistance of the ionomer resin composition. Furthermore, from the viewpoint of the fluidity of the crude ionomer resin solution, the temperature is more preferably above 25°C, and even more preferably above 30°C.

[0070] (Poor solvent) The poor solvent to be added to the crude ionomer resin solution is not particularly limited as long as it mixes with the crude ionomer resin solution and does not dissolve the ionomer resin. Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol; water; ketones such as acetone and methyl ethyl ketone; esters such as methyl acetate and ethyl acetate; ethers such as dimethyl ether, diethyl ether, and tetrahydrofuran; and hydrocarbon compounds such as n-hexane, cyclohexane, and heptane. These may be used individually or in combination of two or more. Among these, the poor solvent is preferably alcohols such as methanol and 2-propanol, water, and mixed solvents thereof, more preferably alcohols such as methanol, because they have a low boiling point, making it easy to dry the ionomer resin, and because they can dissolve salts, making it easy to remove salts from granular resin.

[0071] The amount of poor solvent added may be appropriately selected depending on the concentration of the crude ionomer resin solution. For example, the amount of poor solvent added is preferably 30 parts by mass or more, more preferably 60 parts by mass or more, and particularly preferably 100 parts by mass or more, per 100 parts by mass of the crude ionomer resin solution. There is no particular upper limit to the amount of poor solvent added, and it is usually 1000 parts by mass or less per 100 parts by mass of the crude ionomer resin solution.

[0072] The method of adding the poor solvent to the crude ionomer resin solution is not particularly limited. For example, the poor solvent may be added to the crude ionomer resin solution all at once, or it may be added in multiple steps by dropwise addition. From the viewpoint of reducing the particle size of the granular resin, thereby improving the removal of salts from the granular resin, and consequently improving the transparency of the ionomer resin composition, it is preferable to add the poor solvent in a relatively short time, and more preferably in one step. When adding the poor solvent in multiple steps, it is preferable to complete the addition of the poor solvent within 1 hour, more preferably within 30 minutes, and even more preferably within 10 minutes.

[0073] It is preferable to add a poor solvent to the crude ionomer resin solution and then stir the mixture of the crude ionomer resin solution and the poor solvent. The stirring speed is not particularly limited, but the faster the stirring speed, the easier it is to obtain granular resin with smaller particle sizes. The stirring time is not particularly limited; for example, stirring is sufficient until the granular resin precipitates and the mixture of the crude ionomer resin solution and the poor solvent becomes a slurry. Specifically, it is preferably 1 second to 3 hours, more preferably 10 seconds to 1 hour, and even more preferably 1 minute to 30 minutes.

[0074] (Granular resin) The peak top particle size of the granular resin precipitated by adding a poor solvent to a solution of crude ionomer resin is preferably 700 μm or less, preferably 650 μm or less, more preferably 600 μm or less, and even more preferably 550 μm or less, from the viewpoint of increasing the specific surface area of ​​the granular resin, thereby making it easier to reduce the salt content in the granular resin, and as a result, making it easier to adjust the salt content within the range of 1 to 400 mg / kg, and improving the heat decomposition resistance of the ionomer resin composition. Furthermore, from the viewpoint of easily improving the filterability of the granular resin and easily improving the manufacturing efficiency of the ionomer resin, it is preferably 50 μm or more, more preferably 70 μm or more, and preferably 80 μm or more. The peak top particle size can be determined, for example, by measuring the particle size distribution of the granular resin using a laser diffraction / scattering particle size distribution analyzer.

[0075] The peak top particle size of granular resin precipitated by adding a poor solvent to a crude ionomer resin solution can be adjusted by the concentration and temperature of the crude ionomer resin solution. Specifically, lowering the concentration and / or temperature of the crude ionomer resin solution reduces the peak top particle size of the precipitated granular resin, while increasing the concentration and / or temperature of the crude ionomer resin solution increases the peak top particle size of the precipitated granular resin. Furthermore, the peak top particle size of the granular resin can also be adjusted by the method of adding the poor solvent and the stirring speed of the mixture of the crude ionomer resin solution and the poor solvent.

[0076] (Step iii) (Cleaning solution) The cleaning solution in step iii is not particularly limited as long as it does not dissolve the ionomer resin and is capable of dissolving the salt. Examples of preferred cleaning solutions include alcohols such as methanol, ethanol, 1-propanol, and 2-isopropanol; water; ketones such as acetone and methyl ethyl ketone; esters such as methyl acetate and ethyl acetate; and ethers such as dimethyl ether, diethyl ether, and tetrahydrofuran. These may be used individually or in combination of two or more.

[0077] Among these cleaning solutions, alcohols, water, and mixtures thereof are preferred from the viewpoint of high salt solubility and ease of removing salts contained in granular resin. Furthermore, in addition to increasing salt solubility, a mixture of water and alcohols is more preferred from the viewpoint of increasing the contact area between the cleaning solution and the granular resin by making the specific gravity of the cleaning solution lower than that of the granular resin, thereby improving salt removal efficiency, ease of removing impurities such as organic compounds contained in the granular resin, and ease of drying the ionomer resin obtained after cleaning. Preferred alcohols are methanol, ethanol, and more preferably methanol, due to their ease of drying and high compatibility with water. The ratio of water to alcohols (water / alcohols (mass%)) in a mixture of water and alcohols is preferably 20 / 80 to 80 / 20, and more preferably 30 / 70 to 70 / 30.

[0078] An example of a method for washing granular resin with a washing solution is to filter the granular resin from the granular resin dispersion in step ii, mix the filtered granular resin with the washing solution, and then dewater the mixture. More specifically, a method can be described in which the granular resin filtered from the granular resin dispersion is mixed with the washing solution, the granular resin is filtered from the washing solution (hereinafter also referred to as washing step (a)), and then the filtered granular resin is mixed with a new washing solution, and the granular resin is filtered from the washing solution (hereinafter also referred to as washing step (b)). From the viewpoint of easily adjusting the salt content in the granular resin to within the range of 1 to 400 mg / kg, improving the heat decomposition resistance of the ionomer resin composition, and improving the manufacturing efficiency of the ionomer resin, it is preferable that, in the case of a batch process, the washing of the granular resin is performed by, for example, one washing step (a) followed by one to ten washing steps (b), more preferably one to six times, and even more preferably one to four times, after one washing step (a).

[0079] The amount of cleaning solution used per cleaning step may be appropriately selected depending on the amount of granular resin to be cleaned. For example, the amount of cleaning solution used per cleaning step is preferably 100 to 2000 parts by mass, more preferably 200 to 1000 parts by mass, and even more preferably 300 to 700 parts by mass, per 100 parts by mass of dry granular resin.

[0080] The ionomer resin obtained in step iii may be dried as needed. The drying temperature is preferably below the melting point of the ionomer resin, and more preferably below 80°C.

[0081] [Silane coupling agent] The ionomer resin composition of the present invention contains 0.005 to 0.5 parts by mass of a silane coupling agent per 100 parts by mass of ionomer resin. By including a silane coupling agent within the above range, adhesion to glass, particularly adhesion to glass in a wet state, can be improved. This is thought to be because the silane coupling agent has reactive groups that react with inorganic materials such as glass and reactive groups that react with organic materials such as resin, and therefore the silane coupling agent can bond the ionomer resin and glass by chemical bonds or ionic bonds. Furthermore, in the present invention, even if the amount of silane coupling agent is small, such as 0.005 to 0.5 parts by mass per 100 parts by mass of ionomer resin, the adhesion between the ionomer resin composition and glass can be improved. Therefore, even with the inclusion of a silane coupling agent, the formation of crosslinked gel can be suppressed, and a resin sheet with a good appearance, such as excellent surface smoothness, can be obtained. On the other hand, if the content of the silane coupling agent is below the above lower limit, the adhesion to glass in a wet state tends to decrease, making delamination from glass more likely in a wet state. Furthermore, exceeding the above upper limit makes gelation more likely due to the cross-linking reaction by the silane coupling agent, making it difficult to obtain a resin sheet with a good appearance.

[0082] In one embodiment of the present invention, the content of the silane coupling agent is, from the viewpoint of easily improving adhesion to glass, particularly adhesion to glass in a wet state, 0.005 parts by mass or more, preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.05 parts by mass or more, even more preferably 0.07 parts by mass or more, and particularly preferably 0.08 parts by mass or more, per 100 parts by mass of ionomer resin. Furthermore, from the viewpoint of suppressing gelation of the ionomer resin composition and easily obtaining a resin sheet with a good appearance, the content is 0.5 parts by mass or less, preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, even more preferably 0.2 parts by mass or less, and particularly preferably 0.18 parts by mass or less, per 100 parts by mass of ionomer resin.

[0083] The silane coupling agent is not particularly limited and examples include amino compounds, glycidoxy compounds, sulfide compounds, mercapto compounds, vinyl compounds, nitro compounds, chloro compounds, etc. These silane coupling agents may be used individually or in combination of two or more.

[0084] Examples of amino compounds include N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminomethyl)-3-aminopropyltrimethoxysilane, N-(2-aminomethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminomethyl)-3-aminopropylmethyldiethoxysilane, N-(2-aminomethyl)-3-aminopropyltriethoxysilane, and 3-aminopropyltrimethoxy Examples include sisilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, hydrochloride of N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, N-(2-aminomethyl)-8-aminooctyltrimethoxysilane, N-(2-aminoethyl)-8-aminooctyltrimethoxysilane, N-(2-aminomethyl)-8-aminooctyltriethoxysilane, and N-(2-aminoethyl)-8-aminooctyltriethoxysilane.

[0085] Examples of glycidoxy compounds include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane.

[0086] Examples of sulfide compounds include bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-trimethoxysilylpropyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, and 3-trimethoxysilylpropyl-N,N-dimethyl Examples include luthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, and 3-octanoylthio-1-propyltriethoxysilane.

[0087] Examples of mercapto compounds include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, and 2-mercaptoethyltriethoxysilane.

[0088] Examples of vinyl compounds include vinyltriethoxysilane, vinyltrimethoxysilanedimethoxymethylvinylsilane, and diethoxy(methyl)vinylsilane.

[0089] Examples of nitro compounds include 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane.

[0090] Examples of chloro compounds include 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, and 2-chloroethyltriethoxysilane.

[0091] Other compounds include, for example, diethoxydimethylsilane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, dimethoxydimethylsilane, methyldiethoxysilane, diisopropyldimethoxysilane, dicyclopentyldimethoxysilane, octyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, hexadecyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and N,N,N-tris(3-trimethoxysilylpropyl)triisocyanurate.

[0092] In one embodiment of the present invention, the silane coupling agent may be trialkoxysilane or dialkoxysilane, but from the viewpoint of easily improving adhesion to glass in a wet state, dialkoxysilane is preferred.

[0093] In one embodiment of the present invention, the silane coupling agent is preferably an amino compound or a glycidoxy compound, from the viewpoint of easily improving adhesion to glass in a wet state, more preferably N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and even more preferably N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane. These silane coupling agents can be used alone or in combination of two or more.

[0094] [Other additives] In one embodiment of the present invention, the resin composition of the present invention may contain, in addition to the silane coupling agent, other additives as needed. Examples of additives include ultraviolet absorbers, antioxidants, antioxidants, thermal degradation inhibitors, 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. Among these additives, ultraviolet absorbers, antioxidants, antioxidants, thermal degradation inhibitors, light stabilizers, anti-adhesion agents, lubricants, mold release agents, polymer processing aids, and organic dyes are preferred. The additives may be used individually or in combination of two or more types.

[0095] 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. Examples of UV absorbers include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalate anilides, malonic acid esters, and formamidines. These can be used individually or in combination of two or more.

[0096] 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. Examples of preferred benzotriazoles include 2-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (BASF; trade name: TINUVIN 329), 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (BASF; trade name: TINUVIN 234), 2,2'-methylenebis[6-(2H-benzotriazole-2-yl)-4-t-octylphenol] (ADEKA Corporation; trade name: ADEKA Stab LA-31), and 2-(5-octylthio-2H-benzotriazole-2-yl)-6-tert-butyl-4-methylphenol. These may be used individually or in combination of two or more.

[0097] 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; trade name: ADEKA Stab LA-F70), its analogues such as hydroxyphenyltriazine-based UV absorbers (manufactured by BASF; trade names: TINUVIN477 and TINUVIN460), and 2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine. These can be used individually or in combination of two or more.

[0098] Examples of anti-aging agents include well-known materials. Specific examples of anti-aging agents include phenolic compounds such as hydroquinone, hydroquinone monomethyl ether, 2,5-di-t-butylphenol, 2,6-di(t-butyl)-4-methylphenol, and 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), and 4,4'-thiobis(3-methyl-6-t-butylphenol); and benzimidazole compounds such as 2-mercaptobenzimidazole and 2-mercaptomethylbenzimidazole; 6 Examples include amine-ketone compounds such as -ethoxy-1,2-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. These may be used individually or in combination of two or more.

[0099] 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 a combination of a phosphorus-based antioxidant and a hindered phenol-based antioxidant is more preferred.

[0100] When combining a phosphorus-based antioxidant and a hindered phenol-based antioxidant, the ratio of phosphorus-based antioxidant to hindered phenol-based antioxidant by mass is preferably 1:5 to 2:1, more preferably 1:2 to 1:1.

[0101] Examples of preferred phosphorus-based antioxidants include 2,2-methylenebis(4,6-di-t-butylphenyl)octylphosphite (manufactured by ADEKA Corporation; trade name: Adekastab HP-10), tris(2,4-di-t-butylphenyl)phosphite (manufactured by BASF; trade 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; trade name: Adekastab PEP-36). These may be used individually or in combination of two or more.

[0102] Examples of 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). These may be used individually or in combination of two or more.

[0103] Thermal degradation inhibitors prevent the thermal degradation of resins by capturing polymer radicals that are generated when exposed to high heat under virtually oxygen-free conditions. Examples of preferred thermal degradation inhibitors include 2-t-butyl-6-(3'-t-butyl-5'-methyl-hydroxybenzyl)-4-methylphenyl acrylate (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)phenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd.; trade name: Sumirizer GS). These may be used individually or in combination of two or more.

[0104] Light stabilizers are compounds that primarily function to capture radicals generated by photo-induced oxidation. Examples of preferred light stabilizers include hindered amines, such as compounds with a 2,2,6,6-tetraalkylpiperidine skeleton. These can be used individually or in combination of two or more.

[0105] Examples of anti-adhesion agents include fatty acid salts or esters, polyhydric alcohol esters, inorganic salts, inorganic oxides, and particulate resins. Preferred examples of anti-adhesion agents include calcium stearate, calcium carbonate, calcium sulfate, magnesium sulfate, barium sulfate, silicon dioxide (manufactured by Evonik; trade name: Aerosil), and particulate acrylic resins. These may be used individually or in combination of two or more.

[0106] Examples of lubricants include stearic acid, behenic acid, stearamic acid, methylenebisstearoamide, hydroxystearate triglyceride, paraffin wax, ketone wax, octyl alcohol, and hydrogenated oils. These can be used individually or in combination of two or more.

[0107] 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. These may be used individually or in combination of two or more.

[0108] Polymer processing aids typically use polymer particles having a particle size of 0.05 to 0.5 μm, which can be produced by emulsion polymerization. These polymer particles may be single-layer particles consisting of a polymer with a single composition ratio and a single intrinsic viscosity, or multilayer particles consisting of two or more polymers with different composition ratios or intrinsic viscosities. These may be a single polymer or a combination of two or more polymers. Among these, particles with a two-layer structure are preferred, 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. The intrinsic viscosity of the polymer processing aid is preferably 3 to 6 dl / g. If the intrinsic viscosity is too low, the improvement effect on moldability tends to be low, and if the intrinsic viscosity is too high, it tends to lead to a decrease in the moldability of the copolymer.

[0109] As examples of organic dyes, compounds that have the function of converting ultraviolet light into visible light are preferably used. The organic dye may be used alone or in combination of two or more types.

[0110] Examples of phosphors include fluorescent pigments, fluorescent dyes, fluorescent white dyes, fluorescent whitening agents, and fluorescent bleaching agents. These may be used individually or in combination of two or more types.

[0111] The content of each additive can be appropriately selected within a range that does not impair the effects of the present invention, and the total content of each additive is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less, based on the total mass of the resin composition.

[0112] [Ionomer resin composition] The ionomer resin composition of the present invention comprises an ionomer resin and a silane coupling agent, wherein the ionomer resin comprises (meth)acrylic acid units (A), (meth)acrylic acid neutralized product units (B), and ethylene units (C), the total content of units (A) and (B) is 6 to 10 mol% based on the total monomer units constituting the ionomer resin, the content of salts consisting of strong acids and strong bases in the ionomer resin is 1 to 400 mg / kg, and the content of the silane coupling agent is 0.005 to 0.5 parts by mass per 100 parts by mass of the ionomer resin. As a result, a resin sheet can be formed that has high transparency, high resistance to thermal decomposition, high adhesion to glass in a wet state, and an excellent appearance.

[0113] In one embodiment of the present invention, the ionomer resin content is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more, relative to the total mass of the ionomer resin composition, and also preferably less than 100% by mass, and more preferably 99.99% by mass or less, from the viewpoint of improving transparency, thermal decomposition resistance, and especially adhesion to glass in a wet state.

[0114] As described above, the ionomer resin composition of the present invention contains 1 to 400 mg / kg of salt, and therefore can have high thermal decomposition resistance. In a preferred embodiment of the present invention, the 1% weight loss temperature (Td1) of the ionomer resin composition of the present invention when heated by 10°C / min under a nitrogen atmosphere is preferably 330°C or higher, more preferably 350°C or higher, even more preferably 360°C or higher, particularly preferably 370°C or higher, and usually 450°C or lower. When the 1% weight loss temperature of the ionomer resin composition is above the above lower limit, foaming and / or thermal decomposition of the ionomer resin composition during melt molding is easily reduced, and an interfilm without defects such as black foreign matter caused by bubbles and / or thermal decomposition of the resin can be easily obtained. In this specification, the 1% weight loss temperature represents the temperature at which the weight loss rate becomes 1%, based on the weight at 200°C. The 1% weight loss temperature can be measured according to JIS K7120:1987, and can be measured, for example, by the method described in the examples.

[0115] In one embodiment of the present invention, the storage modulus (E') at 50°C, as measured by dynamic viscoelasticity measurement of the ionomer resin composition of the present invention, is preferably 20 MPa or higher, more preferably 30 MPa or higher, even more preferably 40 MPa or higher, and particularly preferably 50 MPa or higher, from the viewpoint of good self-supporting properties (i.e., high modulus), and especially self-supporting properties in high-temperature environments (high modulus in high-temperature environments). The upper limit of the storage modulus (E') is not particularly limited and may be 1000 MPa. The storage modulus can be adjusted by the molecular weight of the ionomer resin, as well as the content of (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), and optionally (meth)acrylic acid ester units (D).

[0116] The ionomer resin composition of the present invention has high transparency. In one embodiment of the present invention, the haze of the ionomer resin composition of the present invention is preferably 2.0% or less, more preferably 1.5% or less, and even more preferably 1.0% or less. Since the transparency of the ionomer resin composition increases as the haze decreases, the lower limit is not particularly limited and may be, for example, 0.01% or more. The haze of the ionomer resin composition is measured using a haze meter in accordance with JIS K7136:2000.

[0117] The inventors have found that while including salts consisting of strong acids and strong bases in ionomer resins easily improves the heat decomposition resistance of the ionomer resin composition, excessive salt content reduces the transparency of the ionomer resin composition, particularly its transparency when it absorbs water (transparency when water is absorbed). Therefore, the inventors conducted further investigations and found that if the salt content in the ionomer resin is 400 mg / kg or less, the transparency of the ionomer resin composition when it absorbs water can also be improved. Thus, the ionomer resin composition of the present invention, with a salt content of 1 to 400 mg / kg, exhibits high transparency even when water is absorbed. In one embodiment of the present invention, the haze (water-absorbing haze) of the ionomer resin composition of the present invention when it has absorbed water is preferably 9.0% or less, more preferably 5.0% or less, even more preferably 3.0% or less, and particularly preferably 2.5% or less. Since a smaller water-absorbing haze increases the transparency of the ionomer resin composition when it has absorbed water, the lower limit is not particularly limited and may be, for example, 0.01% or more. The water-absorbing haze can be measured using a haze meter in accordance with JIS K7136:2000 by immersing the ionomer resin composition in deionized water at 23°C for 300 hours, removing it from the deionized water, and wiping off the moisture adhering to the surface of the ionomer resin composition as a test piece, and measuring it, for example, by the method described in the examples.

[0118] According to the inventors' studies, if the crystallinity of the ionomer resin is too high, the ionomer resin tends to whiten easily, and the transparency (transparency during slow cooling) tends to decrease when the ionomer resin composition is slowly cooled to promote crystallization. However, in the present invention, the ionomer resin has a total content of 6 mol% or more of (meth)acrylic acid units (A) and (meth)acrylic acid neutralized product units (B) in the resin, making it less prone to crystallization and resulting in high transparency even during slow cooling. In a preferred embodiment of the present invention, the haze (slow-cooled haze) of the ionomer resin composition of the present invention, obtained by promoting the crystallization of the ionomer resin contained in the composition through slow cooling, is preferably 5.0% or less, more preferably 4.5% or less, even more preferably 4.0% or less, even more preferably 3.0% or less, and particularly preferably 2.5% or less. Since a smaller haze increases the transparency of the ionomer resin composition, the lower limit is not particularly limited and may be, for example, 0.01% or more. The slow-cooled haze is obtained by preparing laminated glass by placing a resin sheet formed from the ionomer resin composition as an interlayer between two glass plates, heating the laminated glass to 140°C, and then slowly cooling it from 140°C to 23°C at a rate of 0.1°C / min, and measuring the haze with a haze meter in accordance with JIS K7136:2000.

[0119] In one embodiment of the present invention, the ionomer resin composition of the present invention has a low degree of coloration, and is preferably colorless. From the viewpoint of low coloration, the yellowness (YI) of the ionomer resin composition of the present invention is preferably 2.0 or less, more preferably 1.8 or less, even more preferably 1.5 or less, and particularly preferably 1.0 or less. Since the coloration of the ionomer resin composition decreases as the yellowness (YI) decreases, the lower limit is not particularly limited and may be, for example, 0 or more. The yellowness (YI) can be measured using a colorimeter in accordance with JIS Z8722:2009.

[0120] In one embodiment of the present invention, the adhesive strength of the ionomer resin composition of the present invention to glass is measured, for example, by a compression shear strength test described in WO1999-058334. The compression shear strength is preferably 15 MPa or more, more preferably 20 MPa or more, and particularly preferably 25 MPa or more, from the viewpoint of easily increasing the adhesive strength. The compression shear strength may also be 50 MPa or less, from the viewpoint of easily increasing the penetration resistance of the laminated glass.

[0121] In one embodiment of the present invention, the adhesion of the ionomer resin composition of the present invention to glass in a wet state can be evaluated by the glass adhesion strength of a resin sheet formed from the ionomer resin composition, which is measured by a peel test performed in a wet state. The glass adhesion strength in a wet state is preferably 0.1 N / cm or more, more preferably 0.3 N / cm or more, even more preferably 0.7 N / cm or more, even more preferably 1.0 N / cm or more, and particularly preferably 1.2 N / cm or more. There is no particular upper limit, and it may be 10 N / cm or less. The adhesive strength can be measured by a tensile testing apparatus, for example, by the method described in the examples.

[0122] The ionomer resin composition of the present invention may be made into pellets or other forms to improve convenience during storage, transportation, or molding. When the ionomer resin composition is pelletized, for example, it can be obtained by cutting strands obtained by a melt extrusion method. When pelletizing by melt extrusion, the temperature of the resin composition during melt extrusion is preferably 150°C or higher, more preferably 170°C or higher, from the viewpoint of easily stabilizing discharge from the extruder. Furthermore, the temperature is preferably 250°C or lower, more preferably 230°C or lower, from the viewpoint of suppressing deterioration due to thermal decomposition of the resin. Because the ionomer resin composition of the present invention has high resistance to thermal decomposition, problems such as the generation of black foreign matter due to thermal decomposition of the ionomer resin composition are less likely to occur when pelletizing by melt extrusion in this manner.

[0123] The method for producing the ionomer resin composition of the present invention is not particularly limited, and can be produced, for example, by mixing an ionomer resin, a silane coupling agent, and optionally other additives.

[0124] The method of mixing the ionomer resin and the silane coupling agent is not particularly limited; for example, the silane coupling agent may be directly added to the ionomer resin and mixed. In one embodiment of the present invention, the silane coupling agent may be added as part of the masterbatch of the ionomer resin, and the masterbatch and the ionomer resin may be mixed to adjust the content of the silane coupling agent in the ionomer resin composition. Furthermore, the addition of the silane coupling agent may be carried out in the pelletizing process, the molding process into sheets or films, etc.

[0125] Various additives may be added during the production of the ionomer resin, added to the ionomer resin after its production, or added during the pelletizing process, or during the molding process into sheets, films, etc.

[0126] [Resin sheet] The present invention also includes resin sheets comprising one or more layers containing the ionomer resin composition of the present invention. Because the resin sheet of the present invention comprises layers containing the resin composition of the present invention, it has excellent transparency and adhesion to substrates such as glass, and also has a good appearance with fewer black foreign matter and crosslinked gels.

[0127] The resin sheet of the present invention comprises one or more layers containing the ionomer resin composition of the present invention (hereinafter also referred to as layer (x)). The resin sheet of the present invention may consist only of layer (x), or it may be a laminate containing at least one layer (x). The laminate is not particularly limited, but examples include a laminate containing two or more layers (x), a laminate containing one or more layers (x) and one or more other layers, etc. If layer (x) or other layers are multiple layers, the resin or resin composition constituting each layer may be the same or different.

[0128] Examples of the aforementioned 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, etc. Furthermore, the other layers may also contain, as necessary, one or more additives such as the aforementioned additives, as well as plasticizers, 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.

[0129] In one embodiment of the present invention, from the viewpoint of excellent bubble release when heat-pressing the resin sheet and the substrate together, it is preferable that the resin sheet of the present invention has an uneven surface structure, such as melt fractures or embossing, using conventionally known methods. The shape of the melt fractures and embossing may be appropriately selected from conventionally known methods.

[0130] The thickness of one layer (x) in the resin sheet of the present invention is preferably 0.1 mm or more, more preferably 0.2 mm or more, even more preferably 0.3 mm or more, particularly preferably 0.4 mm or more, and also preferably 5 mm or less, more preferably 4 mm or less, even more preferably 2 mm or less, particularly preferably 1 mm or less. If the layer (x) in the resin sheet consists of multiple layers, the thickness of each of the multiple layers (x) in the resin sheet may be the same or different.

[0131] The thickness of the resin sheet of the present invention is preferably 0.1 mm or more, more preferably 0.2 mm or more, even more preferably 0.3 mm or more, even more preferably 0.4 mm or more, particularly preferably 0.5 mm or more, particularly more preferably 0.6 mm or more, particularly still more preferably 0.7 mm or more, especially preferably 0.75 mm or more, and also preferably 20 mm or less, more preferably 15 mm or less, even more preferably 10 mm or less, even more still more preferably 5 mm or less, particularly preferably 4 mm or less, particularly still more preferably 2 mm or less, and especially still still more preferably 1 mm or less.

[0132] 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.

[0133] In a preferred embodiment of the present invention, the resin sheet of the present invention exhibits the same values ​​as the ionomer resin composition of the present invention described in the section on [Ionomer Resin Composition]: weight loss temperature, haze, water absorption haze, slow cooling haze, yellowness, storage modulus at 50°C, adhesive strength, and adhesive strength in a wet state.

[0134] The resin sheet of the present invention is preferable to have a low water content, from the viewpoint of being less prone to foaming during the manufacture of laminated glass. The water content of the resin sheet 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 particularly preferably 0.01% by mass or less. The above content can be measured by coulometric titration.

[0135] The method for manufacturing the resin sheet of the present invention is not particularly limited. For example, after uniformly kneading the ionomer resin composition of the present invention, layers (x) can be manufactured by known film-forming methods such as extrusion, calendering, pressing, solution casting, melt casting, and inflation. Layers (x) may be used as a resin sheet on their own. Alternatively, two or more layers (x), or one or more layers (x) and one or more other layers, may be laminated into a laminated resin sheet by press molding or the like, or two or more layers (x), or one or more layers (x) and one or more other layers may be molded into a laminated resin sheet by co-extrusion. When there are multiple layers (x) or other layers, the resin compositions constituting each layer may be the same or different.

[0136] Among known film-forming methods, the method of manufacturing a resin sheet using an extruder is preferably used. The resin temperature during extrusion is preferably 150°C or higher, more preferably 170°C or higher, from the viewpoint of stabilizing the discharge of resin from the extruder and reducing mechanical troubles. The resin temperature during extrusion is preferably 250°C or lower, more preferably 230°C or lower, from the viewpoint of reducing resin decomposition and deterioration associated with decomposition. Furthermore, in order to efficiently remove volatile substances, it is preferable to remove volatile substances from the vent port of the extruder by reducing the pressure.

[0137] [Laminated glass interlayer and laminated glass] The resin sheet of the present invention can be suitably used as a laminated glass interlayer (also simply called an interlayer). Therefore, the present invention encompasses a laminated glass interlayer made of the resin sheet of the present invention. The present invention also encompasses laminated glass having two glass plates and the laminated glass interlayer of the present invention disposed between the two glass plates. Because the laminated glass of the present invention has a laminated glass interlayer made of the resin sheet, it can have excellent transparency.

[0138] As the glass plate to be laminated with the interlayer of the present invention, for example, inorganic glass such as float glass, polished glass, patterned glass, wired glass, and heat-absorbing glass can be used, as well as conventionally known organic glass such as polymethyl methacrylate and polycarbonate. These may be colorless or colored. One type may be used, or two or more types may be used in combination. Furthermore, the thickness of one glass plate is preferably 100 mm or less, and the thicknesses of the two glass plates may be the same or different.

[0139] 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.

[0140] When using a vacuum laminator, for example, 1 × 10 -6 ~1 × 10 -1 Laminated glass can be manufactured by laminating a glass plate, an interlayer, and an optional layer (e.g., an adhesive resin layer) under reduced pressure of MPa at 60-200°C, particularly 80-160°C. Methods using vacuum bags or vacuum rings are described, for example, in European Patent No. 1235683, and are approximately 2 × 10⁻⁶ -2 ~3×10 -2 Laminated glass can be manufactured by laminating a glass plate, an interlayer, and any other layer under a pressure of approximately MPa at a temperature of 100-160°C.

[0141] An example of a manufacturing method using nip rolls is a method in which a glass plate, an interlayer, and an arbitrary layer are laminated, degassed by a roll at a temperature below the flow initiation temperature of the interlayer, and then compressed at a temperature close to the flow initiation temperature. Specifically, for example, one method is to heat to 30-70°C with an infrared heater, degas with a roll, heat again to 50-120°C, and then compress with a roll.

[0142] 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.

[0143] Because the ionomer resin composition of the present invention and the resin sheet obtained from the resin composition have high transparency and high adhesion to glass, the laminated glass of the present invention has excellent transparency. In one embodiment of the present invention, the haze of the laminated glass of the present invention is preferably 1.0% or less, more preferably 0.8% or less, and even more preferably 0.5% or less. Since the transparency of the laminated glass increases as the haze decreases, the lower limit is not particularly limited and may be, for example, 0.01%. The haze of the laminated glass is measured using a haze meter in accordance with JIS K7136:2000.

[0144] The laminated glass of the present invention also exhibits excellent transparency during annealing. Transparency during annealing can be evaluated by the haze during annealing (annealing haze). The annealing haze of the laminated glass of the present invention is preferably 5.0% or less, more preferably 4.5% or less, even more preferably 4.0% or less, even more preferably 3.0% or less, and particularly preferably 2.5% or less. Since the transparency of the laminated glass increases as the haze decreases, the lower limit is not particularly limited and may be, for example, 0.01% or more. The annealing haze of the laminated glass is determined by heating the laminated glass to 140°C, then annealing it from 140°C to 23°C at a rate of 0.1°C / min, and measuring the haze using a haze meter in accordance with JIS K7136:2000, which can be determined, for example, by the method described in the examples.

[0145] The laminated glass of the present invention has minimal coloration and is preferably colorless as much as possible. The yellowness (YI) of the laminated glass of the present invention is preferably 3.0 or less, more preferably 2.0 or less, even more preferably 1.5 or less, particularly preferably 1.0 or less, and may preferably be 0 or more. The yellowness (YI) can be measured using a colorimeter in accordance with JIS Z8722.

[0146] The adhesive strength between the glass plate and the interlayer in the laminated glass of the present invention is measured, for example, by a compression shear strength test described in WO1999-058334. From the viewpoint of easily increasing the adhesive strength, the compression shear strength is preferably 15 MPa or more, more preferably 20 MPa or more, and particularly preferably 25 MPa or more. Furthermore, from the viewpoint of easily increasing the penetration resistance of the laminated glass, the compression shear strength may be 50 MPa or less.

[0147] The adhesion between the glass plate and the interlayer in the laminated glass of the present invention in a wet state can be evaluated by the glass adhesive strength of the interlayer, which is measured by a peel test performed in a wet state. The glass adhesive strength in a wet state is preferably 0.1 N / cm or more, more preferably 0.3 N / cm or more, even more preferably 0.7 N / cm or more, even more preferably 1.0 N / cm or more, and particularly preferably 1.2 N / cm or more. There is no particular upper limit, and it may be 10 N / cm or less. The adhesive strength can be measured by a tensile testing apparatus, for example, by the method described in the examples.

[0148] As described above, a resin sheet comprising one or more layers containing the ionomer resin composition of the present invention is useful as an interlayer for laminated glass. This interlayer is particularly preferred as an interlayer for laminated glass used as a structural material (for facades) due to its excellent adhesion to substrates such as glass, transparency, and self-supporting properties.

[0149] Furthermore, the laminated glass of the present invention is not limited to interlayers for structural materials, but can be suitably used in automotive windshields, automotive side windows, automotive sunroofs, automotive rear windows, head-up display glass, 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, solar panels, and the like. [Examples]

[0150] 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.

[0151] [Monomeric content of resins obtained in the examples and comparative examples] The ionomer resin compositions obtained in the examples and comparative examples were analyzed for the content of (meth)acrylic acid units (A), (meth)acrylic acid neutralized product units (B), ethylene units (C), and (meth)acrylic acid ester units (D) in the ionomer resin as follows.

[0152] The ionomer resin compositions obtained in the examples and comparative examples were 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 (meth)acrylic acid neutralized units (B) to (meth)acrylic acid units (A). The resulting resins were thoroughly washed with water, dried, and the dried resins were subjected to the following procedures (1) to (3). (1) The monomer components constituting the resin were analyzed by pyrolysis GC-MS. (2) The acid value of the resin was measured in accordance with JIS K0070:1992. (3) Using a mixed solvent of deuterated toluene and deuterated methanol, the resin 1 1H-NMR (400MHz, manufactured by JEOL Ltd.) measurements were performed. (4) The ionomer resin compositions obtained in the examples and comparative examples were subjected to microwave decomposition pretreatment with nitric acid, and the types and amounts of metal ions in the (meth)acrylic acid neutralized unit (B) were identified by ICP emission spectrometry (Thermo Fisher Scientific iCAP6500Duo). From (1) above, the types and structures of (meth)acrylic acid ester units (D) and (meth)acrylic acid units (A) were identified. From this information, as well as from the information in (2) and (3) above, the ratio of ethylene units (C) / (meth)acrylic acid ester units (D) / (total of (meth)acrylic acid units (A) and (meth)acrylic acid neutralized units (B)) was calculated. Furthermore, from the information in (4) above, the ratio of ethylene units (C) / (meth)acrylic acid ester units (D) / (meth)acrylic acid units (A) / (meth)acrylic acid neutralized units (B) was calculated. Furthermore, the content of each monomer unit of the raw material, ethylene-(meth)acrylic acid ester copolymer (X), was determined by dissolving it in deuterated toluene or deuterated THF. 1 The results were measured and calculated using 1H-NMR (400MHz, manufactured by JEOL Ltd.).

[0153] [Content of salts consisting of strong acids and strong bases in ionomer resin (residual inorganic salt content)] 0.1 g of the ionomer resin obtained in the examples and comparative examples was weighed out, 10 mL of ultrapure water was added to the resin, and the mixture was heated at 90°C for 1 hour. After cooling, it was filtered through a filter with a mesh size of 0.45 μm. The filtrate obtained from filtration was used as the sample solution and measured using an ion chromatograph (manufactured by Shimadzu Corporation) under the following conditions. Chloride ions or sulfate ions were quantified based on the peak area obtained from the measurement, and the amount of chloride ions or sulfate ions was converted to the amount of sodium salt to determine the amount of residual inorganic salt. (Measurement conditions) Eluent: A mixed solution of sodium carbonate aqueous solution (0.6 mmol / L) and sodium bicarbonate aqueous solution (12 mmol / L); Flow rate: 1.0mL / min; Column temperature: 40°C; Column: IC-SA2 (250L x 4.0)

[0154] [Heat decomposition resistance] In accordance with JIS K7120:1987, the thermal decomposition resistance of the ionomer resin compositions obtained in the examples and comparative examples was evaluated. Specifically, using a differential thermogravimetric analyzer TG-DTA7200 (manufactured by Hitachi High-Tech Science Co., Ltd.), the weight loss rate of each resin composition was measured when heated from 20°C to 550°C under a nitrogen atmosphere with a heating rate of 10°C / min and a flow rate of 50 mL / min. The 1% weight loss temperature (Td1), which is the temperature at which the weight loss rate becomes 1% based on the weight at 200°C, was used as an indicator of thermal decomposition resistance.

[0155] [Transparency during water absorption (water absorption haze)] The resin sheets obtained in the examples and comparative examples were cut into 50 mm squares, and the cut samples were immersed in deionized water at 23°C for 300 hours to obtain water-absorbing samples. After wiping off the moisture adhering to the surface of the water-absorbing samples removed from the deionized water, the haze of the water-absorbing samples was measured using a haze meter HZ-1 (manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7136:2000.

[0156] [Transparency during slow cooling (slow cooling haze)] The resin sheets obtained in the examples and comparative examples were sandwiched between two 2.7 mm thick float glass sheets. Using a vacuum laminator (Nisshinbo Mechatronics Co., Ltd., 1522N), the pressure inside the vacuum laminator was reduced to 100°C for 1 minute, and then pressed at 30 kPa for 5 minutes while maintaining the reduced pressure and temperature to obtain a temporary bond. The obtained temporary bond was placed in an autoclave and treated at 140°C and 1.2 MPa for 30 minutes to obtain laminated glass. 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.

[0157] [Glass adhesion strength in a wet state] A 2.7 mm thick float glass was cut into a rectangle 100 mm wide and 200 mm long, and its surface was cleaned. A thin polyester tape (25 μm thick, 25 mm wide) with silicone adhesive was attached to the air surface of the float glass to form two parallel strips, creating a uniform 25 mm wide adhesive area between the polyester tapes. A resin sheet (0.8 mm thick, 150 mm wide, 200 mm long) was placed on this adhesive area, and a 12 μm fluororesin film was then placed on top of the resin sheet. Subsequently, a glass piece different from the float glass was placed on the fluororesin film to obtain a relatively flat surface for the lamination process, and the fluororesin film functioned as a release layer for removing the glass piece. The resulting temporary bond was placed in an autoclave and treated at 140°C and 1.2 MPa for 30 minutes to remove the fluororesin film and the glass piece placed on top of it, obtaining a release test specimen with two layers of float glass and ionomer resin sheet bonded together. Subsequently, each sample was subjected to a peel test at a 90° angle using a tensile testing apparatus (Shimadzu Autograph) to measure the glass adhesion strength. Peeling from the float glass surface to the ionomer resin sheet was performed at 23°C and 50% RH at a head speed of 1 cm / min. After peeling off approximately 100 mm of sample, deionized water was applied to the peel interface between the float glass and the resin sheet to ensure that the interface was completely immersed in liquid water. Then, the peeling speed was reduced to 0.25 mm / min, and another peel test was performed on approximately 100 mm of sample to evaluate the glass adhesion strength. Sufficient water was present to ensure that the sample remained in a "wet" state throughout this test period. The average value of the obtained wet glass adhesion strength was taken as the value.

[0158] [Raw materials] Table 1 shows the amount of methyl methacrylate (MMA) or ethyl acrylate (EA) modification and MFR of each ethylene-(meth)acrylic acid ester copolymer (X) used as a raw material for the ionomer resin in the examples and comparative examples. For EMMA1, we used "Aclift" (registered trademark) WH401F manufactured by Sumitomo Chemical Co., Ltd., and for EEA1, we used "Rexpearl" (registered trademark) A4250 manufactured by Nippon Polyethylene Co., Ltd.

[0159] [Table 1]

[0160] The silane coupling agents used in the examples and comparative examples are shown below. Silane coupling agent 1(S1):3-Glycidoxypropylmethyldiethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) Silane coupling agent 2(S2): N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0161] [Example 1] 100 parts by mass of EMMA2 from Table 1 were introduced into a SUS pressure vessel, and 233 parts by mass of toluene were added. The mixture was stirred at 60°C under a pressure of 0.02 MPa to dissolve the EMMA2. 96 parts by mass of a methanol solution of sodium hydroxide (20% by mass) was added to the resulting solution, and the mixture was stirred at 100°C for 4 hours to saponify the EMMA2 and convert some of the methyl methacrylate units into sodium methacrylate units. Next, after cooling this solution to 50°C, 83 parts by mass of hydrochloric acid (20% by mass) was added, and the mixture was stirred at 50°C for 1 hour to convert some of the sodium methacrylate units into methacrylic acid, obtaining a crude ionomer resin solution. The obtained crude ionomer resin solution was diluted by adding a toluene / methanol (75 / 25% by mass) mixed solvent to a crude ionomer resin concentration of 10% by mass. Next, the diluted crude ionomer resin solution was adjusted to 34°C, and then 430 parts by mass of methanol at 34°C was added to the diluted solution per 100 parts by mass of the crude ionomer resin solution to precipitate granular resin. Next, the obtained granular resin was filtered off, and 100 parts by mass of the filtered granular resin was mixed with 600 parts by mass of a water / methanol (50 / 50% by mass) mixed solvent. The slurry obtained by the above mixing was stirred at 40°C for 1 hour, and then the granular resin was filtered off at room temperature. The granular resin was further washed three times with the water / methanol (50 / 50% by mass) mixed solvent to obtain washed ionomer resin 1. After the obtained ionomer resin 1 was vacuum-dried for 8 hours or more, 100 parts by mass of the ionomer resin 1 and 0.15 parts by mass of a silane coupling agent (S1) were melt-kneaded at 210°C, and the melt-kneaded product was heated at 210°C at 4.9 MPa (50 kgf / cm 2 ) pressure for 5 minutes to obtain an ionomer resin sheet 1 having a thickness of 0.8 mm. The analysis results and evaluation results of ionomer resin sheet 1 are shown in Table 2.

[0162] Example 2 Ionomer resin 2 was obtained in the same manner as in Example 1, except that EMMA3 was used instead of EMMA2, and the temperatures of the dilute solution of the crude ionomer resin and methanol were changed from 34°C to 37°C. 100 parts by mass of ionomer resin 2 and 0.06 parts by mass of a silane coupling agent (S1) were melt-kneaded at 210°C, and the melt-kneaded product was heated at 210°C at 4.9 MPa (50 kgf / cm 2 ) pressure for 5 minutes to obtain an ionomer resin sheet 2 having a thickness of 0.8 mm. The analysis results and evaluation results of the obtained ionomer resin sheet 2 are shown in Table 2.

[0163] Example 3 Ionomer resin 3 was obtained in the same manner as in Example 1, except that EMMA3 was used instead of EMMA2, and the temperatures of the dilute solution of the crude ionomer resin and methanol were changed from 34°C to 40°C. 100 parts by mass of ionomer resin 3 and 0.10 parts by mass of a silane coupling agent (S2) were melt-kneaded at 210°C, and the melt-kneaded product was heated at 210°C at 4.9 MPa (50 kgf / cm 2 ) pressure for 5 minutes to obtain an ionomer resin sheet 3 having a thickness of 0.8 mm. The analysis results and evaluation results of the obtained ionomer resin sheet 3 are shown in Table 2.

[0164] Example 4 Ionomer resin 4 was obtained in the same manner as in Example 3, except that 220 parts by mass of sulfuric acid (30% by mass) was added instead of hydrochloric acid. 100 parts by mass of ionomer resin 4 and 0.25 parts by mass of silane coupling agent (S2) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 The sheet was compressed and molded at a pressure of 0.8 mm for 5 minutes to obtain an ionomer resin sheet 4 with a thickness of 0.8 mm. The analysis and evaluation results of the obtained ionomer resin sheet 4 are shown in Table 2.

[0165] [Example 5] Ionomer resin 5 was obtained in the same manner as in Example 1, except that EEA1 was used instead of EMMA2, the concentration of the diluted crude ionomer resin solution was changed from 10% by mass to 6% by mass, and the temperature of the diluted crude ionomer resin solution and methanol was changed from 34°C to 41°C. 100 parts by mass of ionomer resin 5 and 0.10 parts by mass of silane coupling agent (S2) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 A 0.8 mm thick ionomer resin sheet 5 was obtained by compression molding at a pressure of ) for 5 minutes. The analysis and evaluation results of the obtained ionomer resin sheet 5 are shown in Table 2.

[0166] [Example 6] Ionomer resin 6 was obtained in the same manner as in Example 1, except that EMMA1 was used instead of EMMA2, the amount of sodium hydroxide methanol solution (20% by mass) added was changed from 96 parts by mass to 73 parts by mass, the amount of hydrochloric acid (20% by mass) added was changed from 83 parts by mass to 63 parts by mass, and the temperature of the diluted crude ionomer resin solution and methanol was changed from 34°C to 37°C. 100 parts by mass of ionomer resin 6 and 0.40 parts by mass of silane coupling agent (S2) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 A 0.8 mm thick ionomer resin sheet 6 was obtained by compression molding at a pressure of ) for 5 minutes. The analysis and evaluation results of the obtained ionomer resin sheet 6 are shown in Table 2.

[0167] [Example 7] After obtaining ionomer resin 3 in the same manner as in Example 3, 0.12 parts by mass of silane coupling agent (S2) and 0.1 parts by mass of ultraviolet absorber [2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (BASF; trade name: TINUVIN329)] are added to 100 parts by mass of the ionomer resin 3, and the mixture is melt-kneaded at 210°C. The melt-kneaded mixture is then heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 A 0.8 mm thick ionomer resin sheet 7 was obtained by compression molding at a pressure of ) for 5 minutes. The analysis and evaluation results of the ionomer resin sheet 7 are shown in Table 2.

[0168] [Example 8] Ionomer resin 8 was obtained in the same manner as in Example 1, except that EMMA3 was used instead of EMMA2, and the temperature of the diluted solution containing the crude ionomer resin and methanol was changed from 34°C to 41°C. 100 parts by mass of ionomer resin 8 and 0.11 parts by mass of silane coupling agent (S1) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 A 0.8 mm thick ionomer resin sheet 8 was obtained by compression molding at a pressure of ) for 5 minutes. The analysis and evaluation results of the obtained ionomer resin sheet 8 are shown in Table 2.

[0169] [Example 9] Ionomer resin 9 was obtained in the same manner as in Example 1, except that EMMA3 was used instead of EMMA2, 147 parts by mass of sulfuric acid (30% by mass) was used instead of 83 parts by mass of hydrochloric acid (20% by mass), and the temperature of the diluted solution containing the crude ionomer resin and methanol was changed from 34°C to 41°C. 100 parts by mass of ionomer resin 9 and 0.09 parts by mass of silane coupling agent (S1) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 A 0.8 mm thick ionomer resin sheet 9 was obtained by compression molding at a pressure of ) for 5 minutes. The analysis and evaluation results of the obtained ionomer resin sheet 9 are shown in Table 2.

[0170] [Comparative Example 1] Ionomer resin 10 was obtained in the same manner as in Example 1, except that the temperature of the diluted solution of crude ionomer resin and methanol was changed from 34°C to 43°C. 100 parts by mass of ionomer resin 10 and 0.10 parts by mass of silane coupling agent (S1) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 The sheet was compressed and molded at a pressure of 0.8 mm for 5 minutes to obtain an ionomer resin sheet 10 with a thickness of 0.8 mm. The analysis and evaluation results of the obtained ionomer resin sheet 10 are shown in Table 2.

[0171] [Comparative Example 2] Ionomer resin 11 was obtained in the same manner as in Example 1, except that the temperature of the diluted solution of crude ionomer resin and methanol was changed from 34°C to 46°C. 100 parts by mass of ionomer resin 11 and 0.10 parts by mass of silane coupling agent (S1) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 The sheet was compressed and molded at a pressure of 0.8 mm for 5 minutes to obtain an ionomer resin sheet 11 with a thickness of 0.8 mm. The analysis and evaluation results of the obtained ionomer resin sheet 11 are shown in Table 2.

[0172] [Comparative Example 3] Ionomer resin 12 was obtained in the same manner as in Example 1, except that 220 parts by mass of sulfuric acid (30% by mass) was added instead of hydrochloric acid, and the temperature of the diluted solution of crude ionomer resin and methanol was changed from 34°C to 50°C. 100 parts by mass of ionomer resin 12 and 0.10 parts by mass of silane coupling agent (S1) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 The sheet was compressed and molded at a pressure of 0.8 mm for 5 minutes to obtain an ionomer resin sheet 12 with a thickness of 0.8 mm. The analysis and evaluation results of the obtained ionomer resin sheet 12 are shown in Table 2.

[0173] [Comparative Example 4] Ionomer resin 13 was obtained in the same manner as in Example 1, except that EMMA3 was used instead of EMMA2, and the crude ionomer resin solution was reprecipitated in a mixed solvent of acetone / water (80 / 20% by mass) at a ratio of 500 parts by mass per 100 parts by mass of the crude ionomer resin, and the obtained granular resin was washed three times with a mixed solvent of acetone / water (20 / 80% by mass). 100 parts by mass of ionomer resin 13 and 0.10 parts by mass of silane coupling agent (S2) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 The sheet was compressed and molded at a pressure of 0.8 mm for 5 minutes to obtain an ionomer resin sheet 13 with a thickness of 0.8 mm. The analysis and evaluation results of the obtained ionomer resin sheet 13 are shown in Table 2.

[0174] [Comparative Example 5] Ionomer resin 14 was obtained in the same manner as in Example 1, except that EMMA4 was used instead of EMMA2, the amount of methanol solution of sodium hydroxide (20% by mass) added was changed from 96 parts by mass to 66 parts by mass, and the amount of hydrochloric acid (20% by mass) added was changed from 83 parts by mass to 57 parts by mass. 100 parts by mass of ionomer resin 14 and 0.10 parts by mass of silane coupling agent (S2) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 The sheet was compressed and molded at a pressure of 0.8 mm for 5 minutes to obtain an ionomer resin sheet 14 with a thickness of 0.8 mm. The analysis and evaluation results of the obtained ionomer resin sheet 14 are shown in Table 2.

[0175] [Comparative Example 6] After obtaining ionomer resin 3 in the same manner as in Example 3, 100 parts by mass of the ionomer resin 3 were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 A 0.8 mm thick ionomer resin sheet 15 was obtained by compression molding at a pressure of ) for 5 minutes. The analysis and evaluation results of the ionomer resin sheet 15 are shown in Table 2.

[0176] [Comparative Example 7] After obtaining ionomer resin 3 in the same manner as in Example 3, 100 parts by mass of the ionomer resin 3 and 1.0 part by mass of silane coupling agent (S2) were melt-kneaded at 210°C, and the molten mixture was heated at 210°C under pressure of 4.9 MPa (50 kgf / cm²). 2 Although compression molding was performed for 5 minutes under the pressure specified above, it was not possible to obtain an ionomer resin sheet with a smooth surface due to gelation.

[0177] [Table 2]

[0178] As shown in Table 2, the ionomer resin compositions obtained in Examples 1 to 9 were found to have a high 1% weight loss temperature (Td1), low water absorption haze and slow cooling haze, high transparency, and high glass adhesion in a wet state. Furthermore, the resin sheets produced using the ionomer resin compositions obtained in the examples had few black foreign matter and gelled substances, and good surface smoothness and appearance. In contrast, the ionomer resin compositions obtained in Comparative Examples 1 to 7 showed poor results in at least one of the following: 1% weight loss temperature, water absorption haze, slow cooling haze, and glass adhesion in a wet state.

Claims

1. This is an ionomer resin composition containing an ionomer resin and a silane coupling agent. The ionomer resin contains (meth)acrylic acid units (A), (meth)acrylic acid neutralized product units (B), and ethylene units (C), the total content of units (A) and (B) is 6 to 10 mol% based on the total monomer units constituting the ionomer resin, and the content of salts consisting of strong acids and strong bases in the ionomer resin is 1 to 400 mg / kg. An ionomer resin composition in which the silane coupling agent is contained in an amount of 0.005 to 0.5 parts by mass per 100 parts by mass of the ionomer resin.

2. The ionomer resin composition according to claim 1, wherein the ionomer resin further comprises (meth)acrylic acid ester units (D), and the total content of units (A), (B), and (D) is 6 to 10 mol% based on the total monomer units constituting the ionomer resin.

3. The ionomer resin composition according to claim 1, wherein the salt comprising the strong acid and strong base is a metal salt of an alkali metal and / or an alkaline earth metal.

4. The ionomer resin composition according to claim 1, wherein the salt comprising the strong acid and strong base is a salt comprising at least one cation selected from the group consisting of sodium ions and potassium ions, and at least one anion selected from the group consisting of halogen ions, nitrate ions, and sulfate ions.

5. The ionomer resin composition according to claim 1, wherein the silane coupling agent is at least one silane coupling agent selected from the group consisting of amino compounds, glycidoxy compounds, sulfide compounds, mercapto compounds, vinyl compounds, nitro compounds, and chloro compounds.

6. The ionomer resin composition according to claim 1, wherein the silane coupling agent is at least one silane coupling agent selected from the group consisting of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane.

7. A resin sheet comprising one or more layers containing the ionomer resin composition according to any one of claims 1 to 6.

8. A laminated glass interlayer made of a resin sheet as described in claim 7.

9. Laminated glass comprising two glass plates and a laminated glass interlayer according to claim 8 disposed between the two glass plates.

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