WO2022270540A1

WO2022270540A1 - Resin sheet having layer that contains ionomer resin composition, and laminated glass

Info

Publication number: WO2022270540A1
Application number: PCT/JP2022/024892
Authority: WO
Inventors: 卓郎新村; 淳裕中原; 芳聡淺沼
Original assignee: 株式会社クラレ
Priority date: 2021-06-23
Filing date: 2022-06-22
Publication date: 2022-12-29
Also published as: JPWO2022270540A1

Abstract

The present invention relates to a resin sheet which has one or more layers that contain an ionomer resin composition, wherein: one of the layers that contain an ionomer resin composition forms at least one surface of the resin sheet; the surface has a contact angle of 60 to 75 degrees as determined in accordance with JIS K6768; the ionomer resin composition contains an ionomer resin that has a (meth)acrylic acid unit (A), a neutralized (meth)acrylic acid unit (B) and an ethylene unit (C), and a salt that is formed of a strong acid and a strong base; the total content of the unit (A) and the unit (B) is 6 to 10% by mole based on all monomer units of the ionomer resin; and the content of the salt is 1 to 400 mg/kg based on the total mass of the ionomer resin composition.

Description

Resin sheet and laminated glass having layer comprising ionomer resin composition

This patent application claims priority under the Paris Convention of Japanese Patent Application No. 2021-104270 (filing date: June 23, 2021), and is hereby incorporated by reference in its entirety. shall be incorporated within.
TECHNICAL FIELD The present invention relates to a resin sheet having one or more layers containing an ionomer resin composition, a laminated glass intermediate film comprising the resin sheet, and a laminated glass having the laminated glass intermediate film.

　Ionomer resins, which are neutralized ethylene-unsaturated carboxylic acid copolymers, are used in interlayer films for laminated glass because of their excellent transparency and adhesion to glass (for example, Patent Document 1). As for the adhesion of ionomer resin to float glass, it is known that the adhesion to the air surface is worse than the adhesion to the tin surface.

As a method for improving the adhesion of the ionomer resin sheet to the glass, the surface of the glass is coated with a silane, organic amine (aliphatic amine, ethanolamine, etc.) or diisocyanate type coupling agent before joining the ionomer resin sheet and the glass. is known to prime the For example, Patent Literature 2 describes a method of improving adhesion to an ionomer resin sheet by using a glass sheet coated with an alcohol solution of a metal chelate.

Patent Document 3 describes a resin composition containing an ionomer resin and an adhesion promoter, wherein the adhesion promoter is a dialkoxysilane compound.

Patent Documents 4 and 5 describe a laminated molded product in which the surface of an ionomer resin sheet is subjected to oxidation treatment such as corona treatment or ozone treatment to modify the surface and improve printability or interlayer adhesion.

U.S. Pat. No. 6,432,522 Japanese Patent Application Laid-Open No. 9-227177 WO2019/027865 JP-A-4-64441 Japanese Patent Application Laid-Open No. 2006-52303

However, according to the study of the present inventors, it was found that the laminated glass described in Patent Document 2 has a large variation in adhesiveness and insufficient adhesiveness to the air surface. Further, in some cases, the resin composition described in Patent Document 3 is required to have improved adhesion to the air surface. Furthermore, the laminated molded bodies described in Patent Documents 4 and 5 do not have the adhesiveness required for laminated glass.
Furthermore, in recent years, the demand for laminated glass has increased, and regardless of the production conditions of laminated glass, it is required to maintain high transparency, etc. for laminated glass having a laminated glass intermediate film using an ionomer resin. has become
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a resin sheet having excellent adhesion to glass and excellent transparency.

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, the present invention includes the following.
[1] A resin sheet having one or more layers containing an ionomer resin composition, wherein the layer containing the ionomer resin composition forms at least one surface of the resin sheet, The contact angle of the surface measured in accordance with JIS K6768 is 60 to 75 degrees, and the ionomer resin composition contains (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B ), and an ionomer resin containing ethylene units (C), and a salt composed of a strong acid and a strong base, wherein the total content of the units (A) and the units (B) is the total content of the ionomer resin. A resin sheet, wherein the content of the salt is 6 to 10 mol % based on the monomer units, and the content of the salt is 1 to 400 mg/kg based on the total mass of the ionomer resin composition.
[2] The layer containing the ionomer resin composition forms both surfaces of the resin sheet, and the contact angles of both surfaces measured according to JIS K6768 are 60 to 75 degrees. The resin sheet according to [1].
[3] The ionomer resin further contains (meth)acrylic acid ester units (D), and the total content of the units (A), the units (B) and the units (D) constitutes the ionomer resin. The resin sheet according to [1] or [2], which is 6 to 10 mol % based on the total monomer units.
[4] The resin sheet according to any one of [1] to [3], wherein the salt is a metal salt of alkali metal and/or alkaline earth metal.
[5] The salt comprises 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. The resin sheet according to any one of [1] to [4].
[6] An interlayer film for laminated glass comprising the resin sheet according to any one of [1] to [5].
[7] A laminated glass comprising two glass plates and the interlayer film for laminated glass according to [6] disposed between the two glass plates.

According to the present invention, it is possible to provide a resin sheet that has excellent transparency as well as excellent adhesiveness to glass.

[Resin sheet]
The resin sheet of the present invention has one or more layers containing an ionomer resin composition (hereinafter also referred to as layer (x)). The layer (x) forms at least one surface of the resin sheet, and the surface has a contact angle of 60 to 75 degrees measured according to JIS K6768.
In a preferred embodiment of the present invention, the layer (x) forms both surfaces of the resin sheet, and the contact angles of both surfaces measured according to JIS K6768 are 60 to 75 degrees. is.

The resin sheet of the present invention exhibits excellent adhesion to glass because the contact angle is 60 degrees or more and 75 degrees or less. Surprisingly, it was found that this excellent adhesion was exhibited not only to the tin surface but also to the air surface. The contact angle is preferably 61 degrees or more, more preferably 62 degrees or more, and preferably 74 degrees or less, more preferably 73 degrees or less. When the contact angle is equal to or greater than the lower limit and equal to or less than the upper limit, excellent adhesiveness to glass tends to be exhibited. More specifically, the contact angle is measured by the method described in Examples.

In order to obtain the desired contact angle, the resin sheet may be surface-treated. Examples of surface treatment include corona treatment, plasma treatment, flame plasma treatment, surface oxidation treatment such as ozone treatment, and primer treatment in which a mixture of a silane compound and alcohol is applied. These surface treatments may be performed singly or in combination of two or more. Corona treatment is preferred as the surface treatment.

The corona treatment method is not particularly limited, and either a batch method or an in-line method may be used. The dose of corona treatment can be controlled by device power and/or feed rate. From the viewpoint of easily controlling the contact angle within a suitable range, the dose of corona treatment is preferably 0.01 J/cm ² or more, more preferably 0.05 J/cm ² or more, and still more preferably 0.1 J. /cm ² or more, preferably 50 J/cm ² or less, more preferably 40 J/cm ² or less, and even more preferably 30 J/cm ² or less.

The resin sheet of the present invention may be composed of only one layer (x), or may be a laminate containing at least one layer (x). The structure of the laminate is not particularly limited. Examples thereof include a laminate consisting of two or more layers (x), a laminate including one or more layers (x) and one or more other layers, and the like. When the laminate includes multiple layers (x) or multiple other layers, the resin or resin composition that constitutes each layer (x) or each other layer may be the same or different.

A layer containing a known resin can be used as the other layer. Examples of the resin include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, polytetrafluoroethylene, acrylic resin, polyamide, polyacetal, polycarbonate, polyethylene terephthalate among polyesters, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, Examples include polysulfone, polyethersulfone, polyarylate, liquid crystal polymer, polyimide, and thermoplastic elastomer. In addition, if necessary, the other layer may include additives exemplified in the section [Additives] described later, as well as plasticizers, heat-shielding materials (for example, inorganic heat-shielding fine particles having infrared absorption ability or organic It may contain one or more additives such as a heat shielding material) and a functional inorganic compound.

In a preferred embodiment of the present invention, at least one surface, preferably both surfaces, of the resin sheet of the present invention is coated with a melt from the viewpoint of excellent defoaming properties when the resin sheet and glass are thermocompression bonded. It is preferable to have an uneven structure imparted by a conventionally known method such as a fracture method or an embossing method. The shape of the melt fracture and emboss is not particularly limited, and conventionally known shapes may be appropriately selected.

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, still more preferably 0.3 mm or more, and particularly preferably 0.4 mm or more, Also, it is preferably 5 mm or less, more preferably 4 mm or less, even more preferably 2 mm or less, and particularly preferably 1 mm or less. When the resin sheet includes a plurality of layers (x), the thickness of each layer (x) may be the same or different.

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

The thickness of the resin sheet is measured using a conventionally known method, such as a contact or non-contact thickness gauge. The resin sheet may be in the state of being wound into a roll, or may be in the state of individual sheets.

Next, the components contained in the ionomer resin composition contained in the layer (x), that is, the ionomer resin and the salt composed of strong acid and strong base will be described.

[Ionomer resin]
The ionomer resin in the present invention contains (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), and the units (A) and the units (B) is 6 to 10 mol % based on the total monomer units constituting the ionomer resin.
In the present specification, the term "unit" means a "derived structural unit", for example, a (meth)acrylic acid unit refers to a structural unit derived from (meth)acrylic acid, (meth)acrylic acid The acid-neutralized unit indicates a structural unit derived from a (meth)acrylic acid-neutralized product, and the ethylene unit indicates a structural unit derived from ethylene. Moreover, in this specification, "(meth)acrylic acid" indicates methacrylic acid or acrylic acid.

When the total content exceeds the upper limit, it is difficult to suppress the increase in the melt viscosity during molding of the ionomer resin composition, which tends to reduce the moldability of the ionomer resin composition. Furthermore, when the total content is less than the lower limit, the transparency of the ionomer resin composition, particularly the transparency when the crystallization of the ionomer resin is promoted by slow cooling (hereinafter referred to as the transparency during slow cooling also called) tends to decrease. The total content is 6 mol % or more, preferably 6.5 mol % or more, more preferably 6.5 mol % or more, from the viewpoint of easily improving the transparency of the ionomer resin composition (especially the transparency during slow cooling) and the adhesion to glass. is 7.0 mol% or more, more preferably 7.5 mol% or more, and from the viewpoint of easily obtaining more suitable moldability, 10 mol% or less, preferably 9.9 mol% or less, more preferably is 9.5 mol % or less.

The total content of the units (A) and the units (B) can be adjusted according to the preparation method of the ionomer resin. More specifically, when an ionomer resin is prepared by a method comprising an ethylene-(meth)acrylic acid ester copolymer as a raw material and a saponification reaction step and a demetallization reaction step of the copolymer, ethylene-( Saponification reaction and demetallization reaction for converting (meth)acrylic acid ester units in the meth)acrylic acid ester copolymer into (meth)acrylic acid units (A) and (meth)acrylic acid neutralized units (B) It can be adjusted by each reactivity (conversion rate).

<(Meth) acrylic acid unit (A)>
Examples of monomers constituting the (meth)acrylic acid unit (A) include acrylic acid and methacrylic acid, and methacrylic acid is preferred from the viewpoint of heat resistance and adhesion to glass. The (meth)acrylic acid units may be used singly or in combination of two or more.

The content of the (meth)acrylic acid unit (A) in the ionomer resin is such that the total content of the unit (A) and the unit (B) is 6 to 6 based on the total monomer units constituting the ionomer resin. There is no particular limitation as long as it is within the range of 10 mol %. In one embodiment of the present invention, the content of (meth)acrylic acid units (A) in the ionomer resin is preferably 4.5 mol% or more, based on the total monomer units constituting the ionomer resin, and more Preferably 5.0 mol% or more, more preferably 5.5 mol% or more, particularly preferably 5.8 mol% or more, and preferably 9.0 mol% or less, more preferably 8.5 mol% Below, more preferably 8.0 mol % or less, particularly preferably 7.5 mol % or less. When the content of the unit (A) is at least the lower limit, the transparency of the ionomer resin composition and the excellent adhesion to glass are likely to be obtained. Moreover, when it is equal to or less than the above upper limit, it is easy to obtain more excellent moldability.

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

The content of the (meth)acrylic acid neutralized unit (B) in the ionomer resin is such that the total content of the unit (A) and the unit (B) is the total monomer units constituting the ionomer resin. As a standard, it is not particularly limited as long as it is within the range of 6 to 10 mol %. 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 0.65 mol % or more, based on the total monomer units constituting the ionomer resin. is 1.0 mol% or more, more preferably 1.5 mol% or more, particularly preferably 1.6 mol% or more, and preferably 3.0 mol% or less, more preferably 2.7 mol% or less , more preferably 2.6 mol % or less, particularly preferably 2.5 mol % or less. When the content of the unit (B) is at least the lower limit, it is easy to obtain better transparency and elastic modulus, and when it is at most the upper limit, an increase in melt viscosity during molding is suppressed. Cheap.

Each content of the unit (A) and the unit (B) is obtained by using an ethylene-(meth)acrylic acid ester copolymer as a raw material, and ionomer by a method including a saponification reaction step and a demetallization reaction step of the copolymer. When preparing a resin, the (meth)acrylic acid ester unit in the ethylene-(meth)acrylic acid ester copolymer is replaced with the (meth)acrylic acid unit (A) and the (meth)acrylic acid neutralized product unit (B ) can be adjusted by each reactivity of the saponification reaction and the demetallization reaction.

<Ethylene unit (C)>
The content of ethylene units (C) is preferably 80 mol% or more, more preferably 85 mol% or more, still more preferably 88 mol% or more, and from the viewpoint of easily increasing the transparency of the ionomer resin composition (especially the transparency during slow cooling), preferably 94 mol % or less, more preferably 92 mol % or less.

<(Meth) acrylic acid ester unit (D)>
The ionomer resin in the present invention, in addition to the (meth)acrylic acid unit (A), the (meth)acrylic acid neutralized unit (B), and the ethylene unit (C), from the viewpoint of easily obtaining higher transparency, Furthermore, it is preferable that the (meth)acrylic acid ester unit (D) is included.

When the ionomer resin contains the (meth)acrylic acid ester unit (D), the total content of the unit (A), the unit (B) and the unit (D) increases the transparency (especially during slow cooling). transparency), it is preferably 6 to 10 mol % based on the total monomer units constituting the ionomer resin. That is, in a preferred embodiment of the present invention, the ionomer resin in the present invention comprises (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), ethylene units (C), and ( Including the meth)acrylic acid ester unit (D), the total content of the unit (A), the unit (B) and the unit (D) is 6 based on the total monomer units constituting the ionomer resin. ~10 mol%. When the ionomer resin contains (meth)acrylic acid ester units (D), the total content of the units (A), the units (B) and the units (D) is not more than the upper limit, the ionomer resin composition It is easy to suppress the increase in the melt viscosity during the molding process of the product, and thereby, it is easy to obtain the ionomer resin composition with better moldability. Further, when the total content is at least the lower limit, it is easy to obtain higher transparency of the ionomer resin composition (especially transparency during slow cooling).
When the ionomer resin contains (meth)acrylic acid ester units (D), the total content of the units (A), the units (B) and the units (D) provides higher transparency (especially slow cooling 6 mol% or more, preferably 6.5 mol% or more, more preferably 7.0 mol% or more, still more preferably 7.5 mol% From the viewpoint of moldability, the content is 10 mol % or less, preferably 9.9 mol % or less, more preferably 9.5 mol % or less.

The total content of the units (A), the units (B) and the units (D) can be adjusted depending on the raw material of the ionomer resin. More specifically, when an ethylene-(meth)acrylic acid ester copolymer is used as a raw material and an ionomer resin is prepared by a method including a saponification reaction step and a demetallization reaction step of the copolymer, the ionomer resin It can be adjusted by the (meth)acrylic acid ester modification amount of the raw material ethylene-(meth)acrylic acid ester copolymer. Further, as described in US Pat. No. 8,399,096, when ethylene and (meth)acrylic acid are used as raw materials and these are polymerized to prepare an ionomer resin, ethylene and (meth)acrylic acid to be copolymerized It can be adjusted by the ratio.

Examples of monomers constituting the (meth)acrylate unit (D) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and 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, (meth)acrylic acid Phenyl, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, and (meth)acrylic acid allyl and the like.
Among 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, and more preferred monomers are ( Methyl meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate, and a particularly preferred monomer is methyl (meth)acrylate. These monomers may be used singly or in combination of two or more.

When the ionomer resin contains (meth)acrylic acid ester units (D), the content of the (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 greater than 0 mol %, more preferably more than 0 mol %, based on the total monomer units constituting the ionomer resin. is 0.01 mol% or more, more preferably 0.05 mol% or more, particularly preferably 0.08 mol% or more, and preferably 1.0 mol% or less, more preferably 0.7 mol% or less , more preferably 0.5 mol % or less. When the content of the unit (D) is at least the lower limit and at most the upper limit, higher transparency of the ionomer resin composition can be easily obtained.

When the ionomer resin contains the (meth)acrylic acid ester unit (D), the content of the unit (D) is obtained by using an ethylene-(meth)acrylic acid ester copolymer as a raw material and saponifying the copolymer. and a demetallization reaction step, the (meth)acrylic acid ester unit (D) in the ethylene-(meth)acrylic acid ester copolymer is replaced with the (meth)acrylic acid unit (A ) can be adjusted by the reactivity of the saponification reaction.

<Other monomer units>
The ionomer resin in the present invention comprises (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), and optionally included (meth)acrylic acid ester units ( It may contain monomeric units other than D). Examples of other monomer units include a carboxylic acid unit (A2) other than the (meth)acrylic acid unit (A), and a neutralized carboxylic acid unit other than the (meth)acrylic acid neutralized unit (B). (B2) and the like.
Examples of monomers constituting the carboxylic acid unit (A2) include itaconic acid, maleic anhydride, monomethyl maleate, and monoethyl maleate, with monomethyl maleate and monoethyl maleate being preferred. Examples of the monomer constituting the neutralized carboxylic acid unit (B2) include neutralized units of the neutralized carboxylic acid unit (A2). The neutralized carboxylic acid is obtained by replacing hydrogen ions of carboxylic acid with metal ions. Examples of the metal ions include those similar to the metal ions in the neutralized (meth)acrylic acid unit (B) described above, and the metal ions may be used singly or in combination of two or more.
These other monomer units may be used singly or in combination of two or more.

When the ionomer resin contains the other monomer units, the total content thereof, for example the total content of (A2) and (B2), may be appropriately selected within a range that does not impair the effects of the present invention. Based on the total monomer units constituting the ionomer resin, preferably 5 mol% or less, more preferably 3 mol% or less, still more preferably 1 mol% or less, and preferably 0.01 mol% or more, More preferably, it is 0.1 mol % or more.

(Meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C) in the ionomer resin in the present invention, and (meth)acrylic acid ester units when included ( D) and other monomeric unit contents (e.g., unit (A2) and unit (B2)) are determined by first identifying the monomeric units in the ionomer resin by pyrolysis gas chromatography, then It can be determined by using magnetic resonance spectroscopy (NMR) and elemental analysis. More specifically, it can be determined by the method described in Examples. It can also be determined by a method combining the above analysis method with IR and/or Raman analysis. Prior to these analyses, it is preferable to remove components other than the ionomer resin by reprecipitation or Soxhlet extraction.

In one embodiment of the present invention, the degree of branching per 1000 carbon atoms of the ionomer resin of the present invention is not particularly limited, and is preferably 5-30, more preferably 6-20. The degree of branching is the temperature at which the ionomer resin is polymerized, for example, when an ethylene-(meth)acrylic acid ester copolymer is used as a raw material and the ionomer resin is synthesized by a method including a saponification reaction step of the copolymer. can be adjusted by the polymerization temperature when synthesizing the ethylene-(meth)acrylic acid ester copolymer. The degree of branching per 1000 carbons can be measured by the DDMAS method using solid-state NMR.

The content of the ionomer resin is preferably 90% by mass or more, more preferably 90% by mass or more, based on the total mass of the ionomer resin composition, from the viewpoint of easily increasing the excellent adhesion to glass of the resulting ionomer resin composition and the transparency. is 95% by mass or more, more preferably 98% by mass or more, still more preferably 99% by mass or more, and preferably less than 100% by mass, more preferably 99.99% by mass or less.

[Salts Consisting of Strong Acids and Strong Bases]
The ionomer resin composition in the present invention contains a salt composed of a strong acid and a strong base (hereinafter also simply referred to as "salt") in addition to the ionomer resin. The salt content is 1-400 mg/kg based on the total mass of the ionomer resin composition. The present inventors have found that the resin sheet of the present invention satisfies the requirements of a contact angle of 60 to 75 degrees as described above, and the ionomer resin has the (meth)acrylic acid unit (A) and (meth)acrylic acid as described above. When the total content of hydrated units (B) satisfies the requirement of 6 to 10 mol% and the ionomer resin composition satisfies the requirement of salt 1 to 400 mg/kg, the glass of the resin sheet (not only the tin surface but also the air In addition to high adhesion to the surface), it was found that high transparency can be achieved. On the other hand, if any one of the above three requirements is not satisfied, the resin sheet cannot achieve both high adhesion to glass and high transparency. In addition, the present inventors have found that when the ionomer resin composition contains 1 to 400 mg/kg of salt, it is possible to further achieve high thermal decomposition resistance of the ionomer resin composition. Although it is not clear why the ionomer resin composition contains a salt within the above range, the ionomer resin composition is excellent in thermal decomposition resistance. This is believed to be due to the fact that the action can suppress the (meth)acrylic acid unit (A) in the ionomer resin from desorbing due to heat. Surprisingly, both the adhesion to glass and the thermal decomposition resistance of the ionomer resin composition sharply decreased when the salt content was less than 1 mg/kg, which is also shown in the comparative examples described later. ing.

When the content of the salt exceeds the upper limit, the transparency of the ionomer resin composition tends to be lowered. If the content of the salt is less than the lower limit, the thermal decomposition resistance is lowered, and the ionomer resin composition is likely to be thermally decomposed during, for example, molding processing. Reduced adhesion. The content of the salt is preferably 3 mg/kg or more, more preferably 5 mg/kg or more, based on the total mass of the ionomer resin composition, from the viewpoint of easily improving thermal decomposition resistance. In addition, from the viewpoint of easily improving transparency (especially transparency at the time of water absorption), the total mass of the ionomer resin composition is preferably 380 mg/kg or less, more preferably 340 mg/kg or less, and still more preferably 300 mg/kg. kg or less, particularly preferably 200 mg/kg or less. The salt content in the ionomer resin composition can be measured using ion chromatography, for example, by the method described in Examples.

The salt is not particularly limited, and examples thereof include metal salts of alkali metals and/or alkaline earth metals composed of strong acids and strong bases. These salts may be used singly or in combination of two or more. Examples of alkali metal salts include lithium salts, sodium salts, potassium salts, rubidium salts, cesium salts, and the like. Preferred alkali metal salts are lithium salt, sodium salt, and potassium salt, more preferred are sodium salt and potassium salt, and still more preferred is sodium salt, from the viewpoint of easily increasing the thermal decomposition resistance of the ionomer resin composition. Examples of alkaline earth metal salts include beryllium salts, magnesium salts, calcium salts, strontium salts, barium salts, and the like. Preferred alkaline earth metal salts are magnesium salts and calcium salts from the viewpoint of easily increasing the thermal decomposition resistance of the ionomer resin composition.

From the viewpoint of easily increasing the thermal decomposition resistance of the ionomer resin composition, more preferable salts include at least one cation selected from the group consisting of sodium ion, potassium ion, magnesium ion and calcium ion, halogen ion, sulfate ion, Salts comprising at least one anion selected from the group consisting of nitrate ions and sulfonate ions, more preferably salts comprising at least one cation selected from the group consisting of sodium ions and potassium ions, and halogen It is a salt comprising at least one anion selected from the group consisting of ions, sulfate ions and nitrate ions.

Examples of specific 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, p-toluenesulfonic acid. Sodium, potassium p-toluenesulfonate, magnesium p-toluenesulfonate, and calcium p-toluenesulfonate. More preferred salts are sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, sodium nitrate, and potassium nitrate, and more preferred salts are sodium chloride, sodium sulfate, and Sodium nitrate.

The method of adding a salt to the ionomer resin composition is not particularly limited. ) A method of obtaining an ionomer resin composition by separately adding a salt in the ionomer resin preparation process, and (III) A method of preparing an ionomer resin containing no salt and then adding a salt to the resin to obtain an ionomer resin composition. methods and the like. Among these methods, the method (I) is preferable from the viewpoint of easily dispersing the salt uniformly in the ionomer resin composition, thereby easily improving the transparency and thermal decomposition resistance.

A method for adjusting the content of the salt in the ionomer resin composition can be appropriately selected according to the method for containing the salt. For example, when a salt is added by the above method (I), it can be adjusted by the washing degree of the obtained resin. More specifically, the salt content in the ionomer resin composition can be adjusted by the number of washings in the step of washing the obtained resin with a washing liquid. Examples of the cleaning liquid include solvents that are good solvents for salts and poor solvents for resins, such as water, alcohols such as methanol, ketones such as acetone, and mixed solvents thereof. When the salt is added by the above methods (II) and (III), the salt content in the ionomer resin composition can be adjusted by adjusting the amount of the separately added salt and the amount of the post-added salt.

The dispersion state of the salt in the ionomer resin composition is not particularly limited, but from the viewpoint of easily improving the adhesion to glass, transparency, and thermal decomposition resistance, it is preferable that the salt is uniformly dispersed in the ionomer resin composition.

〔Additive〕
The ionomer resin composition in the present invention may further contain additives, if necessary.
Examples of additives that may optionally be included include UV absorbers, anti-aging agents, antioxidants, thermal degradation inhibitors, light stabilizers, anti-adhesive agents, lubricants, release agents, polymer processing aids, Examples include antistatic agents, flame retardants, dyes, pigments, organic dyes, matting agents, and phosphors. Among these additives, ultraviolet absorbers, anti-aging agents, antioxidants, heat deterioration inhibitors, light stabilizers, anti-sticking agents, lubricants, release agents, polymer processing aids, and organic dyes are preferred. . When the ionomer resin composition contains additives, the additives contained may be used singly or in combination of two or more.

A UV absorber is a compound that has the ability to absorb UV rays, and has the function of mainly converting light energy into heat energy. Examples of UV absorbers include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalic acid anilides, malonic esters, and formamidines. When using an ultraviolet absorber, it may be used alone or in combination of two or more.

Benzotriazoles are preferable as UV absorbers because they are highly effective in suppressing deterioration of optical properties such as coloration due to exposure to UV light. Examples of preferred benzotriazoles include 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (manufactured by BASF; trade name: TINUVIN329), 2 -(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (manufactured by BASF; trade name: TINUVIN234), 2,2'-methylenebis[6-(2H -benzotriazol-2-yl)-4-t-octylphenol] (manufactured by ADEKA Corporation; trade name: ADEKA STAB LA-31), and 2-(5-octylthio-2H-benzotriazol-2-yl)-6 -tert-butyl-4-methylphenol and the like. When benzotriazoles are used, they may be used alone or in combination of two or more.

Examples of triazine UV absorbers include 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine (manufactured by ADEKA Corporation; trade name : Adekastab LA-F70), its analogues hydroxyphenyltriazine-based UV absorbers (manufactured by BASF; trade names: TINUVIN477 and TINUVIN460), and 2,4-diphenyl-6-(2-hydroxy-4-hexyloxy phenyl)-1,3,5-triazine and the like. When triazines are used, they may be used singly or in combination of two or more.

Examples of anti-aging agents include known agents. Examples of specific anti-aging agents include hydroquinone, hydroquinone monomethyl ether, 2,5-di-t-butylphenol, 2,6-di(t-butyl)-4-methylphenol, mono (or di, or tri ) (α-methylbenzyl)phenol and other phenolic compounds; 2,2′-methylenebis(4-ethyl-6-t-butylphenol), 4,4′-butylidenebis(3-methyl-6-t-butylphenol), bisphenol compounds such as 4,4'-thiobis (3-methyl-6-t-butylphenol); benzimidazole compounds such as 2-mercaptobenzimidazole and 2-mercaptomethylbenzimidazole; 6-ethoxy-1,2- Amine-ketone compounds such as dihydro-2,2,4-trimethylquinoline, reaction products of diphenylamine and acetone, 2,2,4-trimethyl-1,2-dihydroquinoline polymers; N-phenyl-1-naphthylamine, Aromatics such as alkylated diphenylamine, octylated diphenylamine, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, p-(p-toluenesulfonylamido)diphenylamine, N,N′-diphenyl-p-phenylenediamine Secondary amine compounds; thiourea compounds such as 1,3-bis(dimethylaminopropyl)-2-thiourea and tributylthiourea; When an anti-aging agent is used, it may be used alone or in combination of two or more.

　Antioxidants are effective by themselves to prevent oxidative deterioration of resins in the presence of oxygen. Examples thereof include phosphorus antioxidants, hindered phenol antioxidants, thioether antioxidants, and the like. When antioxidants are used, they may be used alone or in combination of two or more. From the viewpoint of the effect of preventing deterioration of optical properties due to coloring, a phosphorus antioxidant and a hindered phenol antioxidant are preferable, and a combination of a phosphorus antioxidant and a hindered phenol antioxidant is more preferable.

When a combination of a phosphorus-based antioxidant and a hindered phenol-based antioxidant is used, the amount of phosphorus-based antioxidant used: the amount of hindered phenol-based antioxidant used is preferably 1:5 in mass ratio. ~2:1, more preferably 1:2 to 1:1.

Examples of preferred phosphorus antioxidants include 2,2-methylenebis(4,6-di-t-butylphenyl)octylphosphite (manufactured by ADEKA Corporation; trade name: ADEKA STAB HP-10), Tris (2 ,4-di-t-butylphenyl)phosphite (manufactured by BASF; trade name: IRGAFOS168), 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: ADEKA STAB PEP-36). When using a phosphorus-based antioxidant, it may be used alone or in combination of two or more.

Examples of preferred hindered phenolic antioxidants include pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (manufactured by BASF; trade name: IRGANOX1010), Octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate (manufactured by BASF; trade name: IRGANOX1076) and the like. When hindered phenol-based antioxidants are used, they may be used alone or in combination of two or more.

Thermal degradation inhibitors can prevent thermal degradation of resins by scavenging polymer radicals that are generated when exposed to high heat under virtually oxygen-free conditions. Examples of preferred heat deterioration inhibitors include 2-t-butyl-6-(3′-t-butyl-5′-methyl-hydroxybenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd.; trade name : Sumilizer GM), 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: Sumilizer GS) and the like. When the heat deterioration inhibitor is used, it may be used alone or in combination of two or more.

A light stabilizer is a compound that has the function of scavenging radicals that are mainly generated by light oxidation. Examples of preferred light stabilizers include hindered amines such as compounds having a 2,2,6,6-tetraalkylpiperidine skeleton. When light stabilizers are used, they may be used singly or in combination of two or more.

Examples of anti-adhesion agents include salts or esters of fatty acids, esters of polyhydric alcohols, inorganic salts, inorganic oxides, and particulate resins. Examples of preferred 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. When an anti-tacking agent is used, it may be used alone or in combination of two or more.

Examples of lubricants include stearic acid, behenic acid, stearamic acid, methylenebisstearamide, hydroxystearic triglyceride, paraffin wax, ketone wax, octyl alcohol, and hydrogenated oil. When a lubricant is used, it may be used alone or in combination of two or more.

Examples of release agents include higher alcohols such as cetyl alcohol and stearyl alcohol; glycerin higher fatty acid esters such as stearic acid monoglyceride and stearic acid diglyceride. When a release agent is used, it may be used alone or in combination of two or more.

As the polymer processing aid, polymer particles having a particle size of 0.05 to 0.5 μm, which can be produced by an emulsion polymerization method, are usually used. The polymer particles may be monolayer particles composed of a polymer having a single composition ratio and a single intrinsic viscosity, or may be multilayer particles composed of two or more polymers having different composition ratios or intrinsic viscosities. . When polymer processing aids are used, they may be used alone or in combination of two or more. Among them, particles having a two-layer structure having an inner layer of a polymer layer having a low intrinsic viscosity and an outer layer of a polymer layer having a high intrinsic viscosity of 5 dl/g or more are preferred. The intrinsic viscosity of the polymeric processing aid is preferably 3-6 dl/g. If the intrinsic viscosity is too low, the effect of improving the moldability tends to be low, and if the intrinsic viscosity is too high, the molding processability of the copolymer tends to deteriorate.

A compound that has the function of converting ultraviolet light into visible light is preferably used as the organic dye. When organic dyes are used, they may be used singly or in combination of two or more.

Examples of phosphors include fluorescent pigments, fluorescent dyes, fluorescent white dyes, fluorescent whitening agents, and fluorescent bleaching agents. When phosphors are used, they may be used singly or in combination of two or more.

When these additives are added, the content of various additives can be appropriately selected within a range that does not impair the effects of the present invention, and the total content of various additives is, with respect to the total mass of the ionomer resin composition, It is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less.

Various additives may be added when manufacturing the ionomer resin composition, may be added after manufacturing the ionomer resin composition, or may be added when manufacturing the resin sheet described below.

The ionomer resin composition in the present invention may have a shape such as pellets in order to improve convenience during storage, transportation, or molding. When pelletizing the ionomer resin composition, the pelletization can be carried out, for example, by cutting strands obtained by a melt extrusion method. The temperature of the ionomer resin composition during pelletization by melt extrusion is preferably 150° C. or higher, more preferably 170° C. or higher, from the viewpoint of easily stabilizing the discharge from the extruder. In addition, the temperature is preferably 250° C. or lower, more preferably 230° C. or lower, from the viewpoint of easily suppressing thermal decomposition and deterioration of the ionomer resin. Since the ionomer resin composition of the present invention has high thermal decomposition resistance, problems such as the generation of black foreign matter due to thermal decomposition of the ionomer resin are less likely to occur when the ionomer resin composition is pelletized by the melt extrusion method.

[Method for producing ionomer resin composition]
The method for producing the ionomer resin composition in the present invention is not particularly limited. The ionomer resin composition may be produced by any of the methods (I) to (III) described above as the method of adding a salt to the ionomer resin composition. Among the methods (I) to (III), the salt is easily dispersed uniformly in the ionomer resin composition, thereby easily obtaining improved adhesion to glass, transparency and thermal decomposition resistance. The method (I) is preferred, wherein a salt is formed in the process of preparing the ionomer resin to obtain an ionomer resin composition comprising the ionomer resin and the salt. This method (I) will be described in detail below.

As an example of method (I), an ethylene-(meth)acrylic acid ester copolymer (X) is used as a starting material, and all or part of the (meth)acrylic acid ester units in the copolymer are (meth)acrylic converted to acid units and neutralized (meth)acrylic acid units, (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), ethylene units (C) and optionally (meth ) A crude ionomer resin containing acrylic acid ester units (D) is prepared (step i), a poor solvent is added to the resulting solution containing the crude ionomer resin, and granules containing the crude ionomer resin (hereinafter simply “ (also referred to as "particulate matter") is precipitated (step ii), and then the precipitated particulate matter is washed with a washing liquid (step iii).

<Step (i)>
A method of converting all or part of the (meth)acrylic acid ester units in the ethylene-(meth)acrylic acid ester copolymer (X) to (meth)acrylic acid units and neutralized (meth)acrylic acid units For example, an ethylene-(meth)acrylic acid ester copolymer (X) is saponified with a strong base to convert all or part of the (meth)acrylic acid ester units into neutralized (meth)acrylic acid units. to obtain an ethylene-(meth)acrylic acid neutralized copolymer or ethylene-(meth)acrylic acid ester-(meth)acrylic acid neutralized copolymer, and then the obtained copolymer A method (hereinafter also referred to as method (1)) of demetallizing some of the neutralized (meth)acrylic acid units in the reaction mixture to convert them to (meth)acrylic acid units is exemplified.
Examples of methods other than method (1) include ethylene-(meth)acrylic acid neutralized copolymer obtained by saponification in method (1) or ethylene-(meth)acrylic acid ester-(meth)acrylic acid All the (meth)acrylic acid neutralized units in the hydropolymer are demetallized with a strong acid, converted to (meth)acrylic acid units, and ethylene-(meth)acrylic acid copolymers or ethylene-(meth)acrylic acid units are obtained. ) A method of obtaining an acrylic acid ester-(meth)acrylic acid copolymer and then neutralizing a part of the (meth)acrylic acid units in the obtained copolymer with metal ions (hereinafter, method (2) Also called).
In the methods (1) and (2), the strong base used in the saponification reaction and the strong acid used in the demetallization reaction are neutralized to form a salt composed of a strong acid and a strong base. In method (I), a part of this salt is left to obtain an ionomer resin composition comprising an ionomer resin and a salt after step (iii) described below.

Examples of monomers constituting the (meth)acrylate units of the ethylene-(meth)acrylate copolymer (X) include methyl (meth)acrylate, ethyl (meth)acrylate, (meth)acrylate ) n-propyl acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, (meth) ) amyl 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, Examples include glycidyl (meth)acrylate and allyl (meth)acrylate. Among 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, (meth)acrylate, ) n-propyl acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate, and more preferred monomers are methyl (meth)acrylate, (meth) They are n-butyl acrylate and isobutyl (meth)acrylate, and a particularly preferred monomer is methyl (meth)acrylate. The monomers may be used alone or in combination of two or more.

Specific examples of the ethylene-(meth)acrylic acid ester copolymer (X) include ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacryl Ethyl acid copolymer, ethylene-n-propyl acrylate copolymer, ethylene-n-propyl methacrylate copolymer, ethylene-isopropyl acrylate copolymer, ethylene-isopropyl methacrylate copolymer, ethylene-acrylic acid n-butyl copolymer, ethylene-n-butyl methacrylate copolymer, ethylene-sec-butyl acrylate copolymer, ethylene-sec-butyl methacrylate copolymer and the like.
As these copolymers, commercially available products may be used, and those synthesized by the high-temperature, high-pressure radical polymerization method described in US2013/0274424, JP-A-2006-233059, or JP-A-2007-84743 may be used. Examples of the commercially available products include "Aclift" (registered trademark) WD301F and WH401F manufactured by Sumitomo Chemical Co., Ltd., and "Rekspearl" (registered trademark) A4250 manufactured by Nippon Polyethylene Co., Ltd., and the like.

The content of (meth)acrylate units in the ethylene-(meth)acrylate copolymer (X) is preferably 6 mol% or more, more preferably 6.5 mol% or more, and still more preferably 7 mol. % or more, particularly preferably 7.5 mol % or more, and preferably 10 mol % or less, more preferably 9.9 mol % or less, still more preferably 9.5 mol % or less. The content of (meth)acrylic acid ester units in the copolymer (X) is determined by the (meth)acrylic acid units (A) and (meth)acrylic acid neutralized units in the resulting crude ionomer resin and ionomer resin. (B), and, when included, the (meth)acrylic acid ester unit (D) corresponding to the total content, so the content of the (meth)acrylic acid ester unit in the copolymer (X) is the lower limit When the content is equal to or more than the upper limit, the resulting ionomer resin composition is more suitable when the content is equal to or less than the upper limit. It is easy to obtain good moldability.
The content of (meth)acrylic acid ester units in the copolymer (X) can be adjusted by the copolymerization ratio of ethylene and (meth)acrylic acid ester. In addition, the content is the (meth)acrylic acid unit (A), the (meth)acrylic acid neutralized product unit (B), and the ethylene unit (C) in the ionomer resin described above, and when included (meth) As well as the contents of acrylic acid ester units (D) and other monomeric units (e.g. units (A2) and units (B2)), pyrolysis gas chromatography, nuclear magnetic resonance spectroscopy (NMR) and It can be determined by elemental analysis.

In one embodiment of the present invention, the melt flow rate (MFR ) is preferably 5 g/10 min or more, more preferably 10 g/10 min or more, still more preferably 50 g/10 min or more, still more preferably 100 g/10 min or more, preferably 400 g/10 min or less, more It is preferably 350 g/10 minutes or less, more preferably 300 g/10 minutes or less, and even more preferably 250 g/10 minutes or less. When the MFR of the ethylene-(meth)acrylic acid ester copolymer (X) is at least the lower limit and at most the upper limit, more suitable moldability and higher strength of the resulting ionomer resin composition are likely to be obtained. . The MFR of the ethylene-(meth)acrylic acid ester copolymer (X) can be adjusted by the degree of polymerization and the content of (meth)acrylic acid ester units. The MFR can be measured, for example, by the method described in Examples.

The weight-average molecular weight of the ethylene-(meth)acrylic acid ester copolymer (X) is preferably 15,000 g/mol or more, more It is preferably 20,000 g/mol or more, more preferably 30,000 g/mol or more, preferably 200,000 g/mol or less, more preferably 100,000 g/mol or less. From the same point of view, the number average molecular weight of the ethylene-(meth)acrylate copolymer (X) is preferably 5,000 g/mol or more, more preferably 10,000 g/mol or more, still more preferably 15 ,000 g/mol or more, preferably 100,000 g/mol or less, more preferably 50,000 g/mol or less. The weight average molecular weight and number average molecular weight can be adjusted by adjusting the amount of polymerization initiator and/or chain transfer agent during polymerization. The molecular weights (weight average molecular weight and number average molecular weight) of these ethylene-(meth)acrylic acid ester copolymers (X) are determined by column (TSKgel GMH _HR -H(20)HT three in series) and 1,2, Using 4-trichlorobenzene as a solvent, the measurement can be performed at a column temperature of 140° C. in terms of polystyrene.

The degree of branching per 1000 carbon atoms of the ethylene-(meth)acrylic acid ester copolymer (X) is not particularly limited, and is preferably 5-30, more preferably 6-20. The degree of branching can be adjusted by adjusting the polymerization temperature when the ethylene-(meth)acrylate copolymer (X) is polymerized. The degree of branching can be measured by performing a ¹³ C-NMR inverse gate decoupling method using an ethylene-(meth)acrylate copolymer (X) dissolved in deuterated ortho-dichlorobenzene. .

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. Sodium hydroxide and potassium hydroxide are preferred from the viewpoints of solubility in the solvent used for the saponification reaction and economic efficiency. You may use an alkali individually by 1 type or in combination of 2 or more types.

Examples of solvents used in the saponification reaction include ethers such as tetrahydrofuran and dioxane; halogen-containing solvents such as chloroform and dichlorobenzene; ketones having 6 or more carbon atoms such as methylbutyl ketone; mixed solvents with alcohols such as 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 alone or in combination of two or more.
Among 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 toluene and the like. is a mixed solvent of an aromatic compound and an alcohol such as methanol. The ratio of the hydrocarbon compound or aromatic compound and alcohol in the mixed solvent may be appropriately selected according to the type of each solvent used. For example, the mass ratio of the hydrocarbon compound or aromatic compound and alcohol ( hydrocarbons or aromatics/alcohols) can be from 50/50 to 90/10.

The temperature at which the saponification reaction is performed is preferably 50° C. or higher, more preferably 60° C. or higher, from the viewpoint of reactivity and solubility of the ethylene-(meth)acrylic acid ester copolymer (X). It is preferably 70° C. or higher, particularly preferably 80° C. or higher. The upper limit of the temperature is not particularly limited as long as it is lower than the temperature at which the ethylene-(meth)acrylic acid ester copolymer (X) decomposes, and is, for example, 300° C. or less.

The saponification reaction may be performed in the air or in an inert gas such as nitrogen gas or argon gas. Moreover, the saponification reaction may be carried out under normal pressure, under pressure, or under reduced pressure, preferably under pressure.

Examples of acids used for demetallization in methods (1) and (2) include strong acids such as hydrochloric acid, nitric acid, sulfuric acid, and toluenesulfonic acid. Among these, inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid are preferable from the viewpoint of easy removal of salts from the ionomer resin composition after demetalization. You may use an acid individually by 1 type or in combination of 2 or more types. As the solvent used for the demetallization reaction, the same solvents as those used for the saponification reaction described above can be selected.

The temperature at which the demetallization is performed is preferably 20° C. or higher, more preferably 30° C. or higher, still more preferably 40° C. or higher, and preferably 100° C. or lower, from the viewpoint of easily lowering the viscosity of the reaction solution. It is more preferably 80° C. or lower, still more preferably 60° C. or lower.

The demetallization may be performed in the air or in an inert gas such as nitrogen gas or argon gas. Moreover, the saponification reaction may be carried out under normal pressure, under pressure, or under reduced pressure, preferably under pressure.

In the method (2), the neutralizing agent used for partially neutralizing the (meth)acrylic acid units and converting them into neutralized (meth)acrylic acid units is an ionic compound containing metal ions. There is no particular limitation if any. 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. is mentioned. For example, when the metal ion is sodium ion, examples of the neutralizing agent include sodium hydroxide and the like.

<Step (ii)>
(Solution containing crude ionomer resin)
The crude ionomer resin obtained in step (i) comprises (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B) and ethylene units (C), wherein said units (A) and The total content of the units (B) is 6 to 10 mol % based on the total monomer units constituting the crude ionomer resin. In addition, the crude ionomer resin preferably contains (meth)acrylic acid ester units (D) in addition to the units (A), (B) and (C). ) When the acrylic acid ester unit (D) is included, the total content of the unit (A), the unit (B) and the unit (D) is 6 based on the total monomer units constituting the ionomer resin. It is preferably ~10 mol %. In addition to the units (A), (B), and (C), and optionally the units (D), the crude ionomer resin further contains carboxylic acids other than (meth)acrylic acid units. Acid units (A2) and other monomer units such as neutralized carboxylic acid units (B2) other than neutralized (meth)acrylic acid units may be included.

Examples of the unit (A) and the unit (B) in the crude ionomer resin, the unit (D) which may optionally be included, and other monomeric units (A2) and (B2) are Units (A), units (B), units (D), units (A2) and units (B2) contained in the ionomer resin in the invention include the same units as those described above. similar to ionomer resins. In addition, the content of each unit in the crude ionomer resin, the total content of units (A) and units (B), and optionally units (A), units (B) and units when unit (D) is included The total content of (D) is also the same as the content or total content described above for the ionomer resin in the present invention, including preferred forms.

The solution containing the 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) is used as the solution containing the crude ionomer resin. may be used.

The solvent in the solution containing the crude ionomer resin is not particularly limited as long as it can dissolve the crude ionomer resin, and examples thereof include the same solvents as those used in the saponification reaction. Among them, a mixed solvent of an aromatic compound such as toluene and an alcohol such as methanol is preferable from the viewpoint of solubility of the crude ionomer resin. The ratio of the aromatic compound to the alcohol in the mixed solvent may be appropriately selected according to the type of each solvent used. For example, the mass ratio of the aromatic compound to the alcohol (aromatic compound/alcohol) is , 50/50 to 90/10, preferably 65/35 to 85/15.

The concentration of the solution containing the crude ionomer resin is preferably 30 mass from the viewpoint that it is easy to obtain granules with a small particle size and, as a result, it is easy to adjust the salt content in the ionomer resin composition described later within a predetermined range. % or less, more preferably 15 mass % or less, preferably 1 mass % or more, more preferably 5 mass % or more.

The temperature of the solution containing the crude ionomer resin tends to suppress aggregation or agglomeration of the precipitated particles, and the salt content in the ionomer resin composition is easily adjusted within the range of 1 to 400 mg/kg. It is preferably below the melting point of the resin, more preferably 60° C. or below, and even more preferably 50° C. or below. From the viewpoint of fluidity of the solution containing the crude ionomer resin, the temperature is more preferably 25° C. or higher, more preferably 30° C. or higher.

(poor solvent)
The poor solvent added to the solution containing the crude ionomer resin is not particularly limited as long as it is mixed with the solution containing the crude ionomer resin and does not dissolve the ionomer resin. Examples thereof 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 tetrahydrofuran; and hydrocarbon compounds such as n-hexane, cyclohexane, heptane, and the like. The poor solvent may be used alone or in combination of two or more. Among them, the poor solvent is preferably methanol, 2-propanol, or the like, from the viewpoint that the ionomer resin composition can be easily dried due to its low boiling point, and the salt can be dissolved in the granules so that the salt can be easily removed. alcohols, water, and mixed solvents thereof, more preferably alcohols such as methanol.

The amount of poor solvent to be added may be appropriately selected according to the concentration of the solution containing the crude ionomer resin. For example, the amount of the poor solvent to be 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 with respect to 100 parts by mass of the solution containing the crude ionomer resin. The upper limit of the amount of the poor solvent to be added is not particularly limited, and is usually 1000 parts by mass or less with respect to 100 parts by mass of the solution containing the crude ionomer resin.

The method of adding the poor solvent to the solution containing the crude ionomer resin is not particularly limited. may The particle size of the granules tends to become smaller, which makes it easier to improve the removability of the salt in the granules, and as a result, the transparency of the ionomer resin composition tends to be improved. It is preferable to carry out in a short time, and it is more preferable to add at once. When the poor solvent is added in multiple portions, the addition of the poor solvent is preferably completed within 1 hour, more preferably within 30 minutes, and even more preferably within 10 minutes.

After adding the poor solvent to the solution containing the crude ionomer resin, it is preferable to stir the mixture of the solution containing the crude ionomer resin and the poor solvent. The stirring speed is not particularly limited, but the faster the stirring speed, the easier it is to obtain granules with a smaller particle size. The stirring time is not particularly limited, and, for example, the particles may be precipitated and the mixture of the solution containing the crude ionomer resin and the poor solvent may be stirred until it becomes slurry. A specific time is preferably 1 second to 3 hours, more preferably 10 seconds to 1 hour, and even more preferably 1 minute to 30 minutes.

(particulate matter)
The peak top particle size of the granules precipitated by adding a poor solvent to the solution containing the crude ionomer resin becomes easy to reduce the salt content in the granules by increasing the specific surface area of the granules. , the salt content is preferably 700 μm or less, more preferably 650 μm or less, still more preferably 600 μm or less, and particularly preferably 550 μm or less, from the viewpoint of facilitating adjustment of the salt content within the range of 1 to 400 mg/kg. Further, from the viewpoint of easily obtaining suitable filterability of the particulate matter and easily improving the production efficiency of the ionomer resin, the particle size is preferably 50 μm or more, more preferably 70 μm or more, and still more preferably 80 μm or more. The peak top particle size can be measured, for example, by a laser diffraction/scattering method or a single light scattering method.

The peak top particle size of the particulate material precipitated by adding a poor solvent to the solution containing the crude ionomer resin can be adjusted by the concentration and temperature of the solution containing the crude ionomer resin. Specifically, when the concentration and/or temperature of the solution containing the crude ionomer resin are lowered, the peak top particle size of the precipitated particulate matter can be reduced, and when the concentration and/or temperature of the solution containing the crude ionomer resin is increased, The peak top particle size of precipitated particulates can be increased. The peak top particle size of the particulate matter can also be adjusted by the method of adding the poor solvent and the stirring speed of the mixture of the solution containing the crude ionomer resin and the poor solvent.

<Step (iii)>
(washing liquid)
The washing liquid 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 washing liquids 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 of The washing liquid may be used alone or in combination of two or more.

Among these washing liquids, alcohols, water, and mixed liquids thereof are preferable from the viewpoint of high solubility of salts and easy removal of salts contained in the particulate matter. Furthermore, by increasing the solubility of the salt and by making the specific gravity of the cleaning liquid smaller than that of the granular material, thereby increasing the contact area between the cleaning liquid and the granular material, the removability of the salt can be easily increased. A more preferable cleaning liquid is a mixed liquid of water and alcohols from the viewpoint of facilitating removal of impurities such as organic compounds contained in the ionomer resin composition and facilitating drying of the ionomer resin composition obtained after washing. Preferred alcohols are methanol and ethanol, more preferably methanol, because they are easy to dry and have high compatibility with water.
The ratio of water and alcohols (water/alcohols (% by mass)) in the mixture of water and alcohols is preferably 20/80 to 80/20, more preferably 30/70 to 70/30. .

As an example of the method of washing the particulate matter with a washing liquid, there is a method of filtering the particulate matter from the dispersion liquid of the particulate matter obtained in the step (ii), mixing the filtered particulate matter with the washing liquid, and then dewatering. mentioned. More specifically, after mixing the granules filtered from the dispersion and the washing liquid, the granules are filtered from the washing liquid (hereinafter also referred to as washing step (a)), and then the filtered granules are filtered. is mixed with a new washing liquid, and then the particulate matter is filtered out of the washing liquid (hereinafter also referred to as washing step (b)). From the viewpoint of easy adjustment of the salt content in the granules within the range of 1 to 400 mg/kg and the production efficiency of the ionomer resin, the granules are washed in a batch process, for example, in one washing step. After (a), the washing step (b) is preferably performed 1 to 10 times, and the number of washing steps (b) after one washing step (a) is more preferably 1 to 6 times. It is preferably 1 to 4 times.

The amount of the cleaning liquid used in one cleaning step may be appropriately selected according to the amount of granular material to be cleaned. For example, the amount of the cleaning liquid used in one cleaning process is preferably 100 parts by mass to 2000 parts by mass, more preferably 200 parts by mass to 1000 parts by mass, and still more preferably 100 parts by mass of the dried granular material. is 300 parts by mass to 700 parts by mass.

The ionomer resin composition comprising the ionomer resin and salt obtained after step (iii) may be dried if necessary. The drying temperature is preferably below the melting point of the ionomer resin, more preferably below 80°C. Drying may be performed under reduced pressure.

<Characteristics of ionomer resin composition>
As described above, the ionomer resin composition of the present invention can exhibit high thermal decomposition resistance due to the inclusion of a specific amount of salt. As a result, the ionomer resin composition in the present invention can have a higher 1% weight loss temperature (Td1) and a lower degree of coloration.
The 1% weight loss temperature of the ionomer resin composition of the present invention when the temperature is raised at 10°C/min in a nitrogen atmosphere is preferably 330°C or higher, more preferably 350°C or higher, still more preferably 360°C or higher, and particularly preferably 360°C or higher. 370°C or higher. The 1% weight loss temperature is usually 450° C. or lower. When the 1% weight loss temperature of the ionomer resin composition is at least the above lower limit, foaming and/or thermal decomposition during melt molding of the ionomer resin composition is likely to be reduced, and air bubbles and/or thermal decomposition of the resin It is easy to obtain a resin sheet free from defects such as black foreign matter. In this specification, the 1% weight reduction temperature represents the temperature at which the weight reduction rate becomes 1% based on the weight at 200°C. The 1% weight loss temperature can be measured according to JIS K7120:1987, for example, by the method described in Examples.
The degree of coloring of the ionomer resin composition in the present invention is small, and the ionomer resin composition in the present invention is preferably colorless. The yellowness index (YI) at a sheet thickness of 0.8 mm of the ionomer resin composition of the present invention is preferably 2.0 or less, more preferably 1.8 or less, still more preferably 1.5 or less, particularly preferably 1 .0 or less. The lower the yellowness, the lower the colorability of the ionomer resin composition, so the lower limit is not particularly limited, and may be 0, for example. Note that the yellowness can be measured using a colorimetric color difference meter in accordance with JIS Z8722:2009.

As mentioned above, the ionomer resin composition of the present invention has high transparency due to the inclusion of a specific amount of salt. The haze of the sheet of the ionomer resin composition of the present invention at a thickness of 0.8 mm is preferably 2.0% or less, more preferably 1.5% or less, still 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%. The haze of the ionomer resin composition is measured using a haze meter according to JIS K7136:2000.

In addition, as described above, the ionomer resin composition of the present invention has transparency, especially transparency when the ionomer resin composition absorbs water ( transparency). The haze (water absorption haze) at a thickness of 0.8 mm when the sheet of the ionomer resin composition of the present invention absorbs water is preferably 9.0% or less, more preferably 5.0% or less, and still more preferably 4.0. % or less, particularly preferably 3.0% or less. The lower the water absorption haze, the higher the transparency of the ionomer resin composition after absorbing water. The water absorption haze can be measured, for example, by the method described in Examples.

According to studies by the present inventors, when the crystallinity of the ionomer resin is too high, the ionomer resin tends to whiten easily. Therefore, when the ionomer resin is slowly cooled to accelerate the crystallization of the resin, the transparency of the ionomer resin (transparency during slow cooling) tends to decrease. However, in the ionomer resin of the present invention, the total content of (meth)acrylic acid units (A) and (meth)acrylic acid neutralized units (B) in the resin is 6 mol% or more. Also, the resin is difficult to crystallize. As a result, the ionomer resin composition of the present invention containing such an ionomer resin can have high transparency even in a state in which crystallization of the ionomer resin is promoted by slow cooling.
The haze (gradual cooling haze) of the ionomer resin composition in the present invention in a state in which crystallization of the ionomer resin is promoted by slow cooling is preferably 5.0% or less, more preferably 4.5% or less, and even more preferably 4.5% or less. is 4.0% or less, more preferably 3.0% or less, and particularly preferably 2.5% 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%. Slow-cooling haze is obtained by disposing a sheet of an ionomer resin composition having a thickness of 0.8 mm between two glass plates to prepare a laminated glass, heating the laminated glass to 140 ° C., and then reducing the haze from 140 ° C. The haze after slowly cooling to 23°C at a rate of 1/min can be measured by measuring with a haze meter in accordance with JIS K7136:2000.

In one embodiment of the present invention, the melting point of the ionomer resin composition in the present invention is preferably 50°C or higher, more preferably 60°C or higher, and still more preferably 80°C or higher, from the viewpoint of heat resistance and thermal decomposition resistance. In addition, the temperature is preferably 200° C. or lower, more preferably 180° C. or lower, and still more preferably 150° C. or lower, from the viewpoint that the adhesive strength with glass is easily exhibited when producing laminated glass. The melting point can be measured based on JIS K7121:2012. Specifically, using a differential scanning calorimeter (DSC), measurement was performed under the conditions of a cooling rate of −10° C./min and a heating rate of 10° C./min, and from the pick-top temperature of the melting peak of the second heating can ask.

In one embodiment of the present invention, the heat of fusion of the ionomer resin composition in the present invention is preferably 0 J/g or more and 25 J/g or less. The heat of fusion can be measured based on JIS K7122:2012. Specifically, using a differential scanning calorimeter (DSC), measurement was performed under the conditions of a cooling rate of −10° C./min and a heating rate of 10° C./min, and the area of the melting peak during the second heating was calculated. can do.

In one embodiment of the present invention, the melt flow rate (MFR) of the ionomer resin composition of the present invention measured under conditions of 190°C and 2.16 kg according to JIS K7210-1:2014 is preferably 0. 1 g/10 min or more, more preferably 0.3 g/10 min or more, still 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 minutes or less, more preferably 30 g/10 minutes or less, and particularly preferably 10 g/10 minutes or less. When the MFR of the ionomer resin composition is not less than the lower limit and not more than the upper limit, it is easy to perform molding while suppressing deterioration due to heat, and it is easy to obtain a resin sheet having excellent penetration resistance.

The melting point, heat of fusion, and MFR of the ionomer resin composition are determined by the molecular weight of the ionomer resin, and the (meth)acrylic acid unit (A), neutralized (meth)acrylic acid unit (B), and ethylene unit (C) of the ionomer resin. ) and the content of (meth)acrylic acid ester units (D) optionally included.

In one embodiment of the present invention, the storage elastic modulus (E′) at 50° C. measured by dynamic viscoelasticity measurement of the ionomer resin composition in the present invention is suitable self-sustainability (i.e., high elastic modulus), In particular, from the viewpoint of self-sustainability in high-temperature environments (high elastic modulus in high-temperature environments), it 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. The upper limit of the storage modulus (E') is not particularly limited, and may be 1000 MPa. Said storage modulus is determined by the molecular weight of the ionomer resin and the (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), ethylene units (C), and the optionally included (meth)acrylic acid It can be adjusted by the content of the acid ester unit (D).

[Method for manufacturing resin sheet]
The method for producing the resin sheet of the present invention is not particularly limited. For example, after uniformly kneading the ionomer resin composition of the present invention, the layer (x) can be produced by a known film-forming method such as an extrusion method, a calendar method, a press method, a solution casting method, a melt casting method, or an inflation method. . Layer (x) may be used alone as a resin sheet. In addition, if necessary, two or more layers (x), or one or more layers (x) and one or more other layers are laminated by press molding or the like to obtain a laminate, or two At least one layer (x), or at least one layer (x) and at least one other layer may be formed by a coextrusion method to obtain a laminate, and this laminate may be used as a resin sheet. good. When the laminate includes multiple layers (x) or multiple other layers, the resin or resin composition that constitutes each layer (x) or each other layer may be the same or different.

Among known film forming methods, a method of producing a resin sheet using an extruder is preferably used. The resin temperature or the resin composition temperature during extrusion is preferably 150° C. or higher, more preferably 170° C. or higher, from the viewpoints of easily stabilizing the discharge of the resin from the extruder and easily reducing mechanical troubles. The temperature is preferably 250° C. or lower, more preferably 230° C. or lower, from the viewpoint of facilitating decomposition of the resin and deterioration of the resin accompanying the decomposition. Moreover, in order to remove the volatile substances efficiently, it is preferable to remove the volatile substances from the vent port of the extruder by reducing the pressure.
After the resin sheet is produced by a known film-forming method, the resin sheet may be subjected to surface treatment to obtain a desired contact angle, as described in the previous section [Resin sheet].

The resin sheet of the present invention has high transparency, high thermal decomposition resistance, and excellent adhesion to glass due to the features of the ionomer resin composition of the present invention.
That is, in a preferred embodiment of the present invention, the resin sheet of the present invention has the same haze, water absorption haze, slow cooling haze, storage modulus, 1% weight reduction degree and yellowness as those of the ionomer resin composition of the present invention. can have

The adhesive strength between the resin sheet of the present invention and glass is measured by, for example, a compressive shear strength test described in WO1999/058334. More specifically, it is measured by the method described in Examples.
The compressive shear strength against the tin surface of the resin sheet of the present invention is preferably 25 MPa or higher, more preferably 27 MPa or higher, still more preferably 29 MPa or higher, and particularly preferably 31 MPa or higher. The compressive shear strength against the air surface of the resin sheet of the present invention is preferably 25 MPa or more, more preferably 28 MPa or more, and particularly preferably 30 MPa or more. Moreover, the compressive shear strength against the tin surface or the air surface may be 50 MPa or less from the viewpoint of easily increasing the penetration resistance of the laminated glass.

The resin sheet of the present invention preferably has a low water content, for example, from the viewpoint that the resin sheet is less likely to foam during the production of laminated glass when the resin sheet is used as an interlayer film for laminated glass. The water content of the resin sheet is preferably 1% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.02% by mass or less, and particularly preferably 0.01% by mass or less. The content can be measured by a coulometric titration method.

[Laminated glass intermediate film and laminated glass]
The resin sheet of the present invention can be suitably used as an intermediate film for laminated glass (also simply referred to as an intermediate film). Therefore, the present invention includes a laminated glass interlayer made of the resin sheet of the present invention. The invention also includes a laminated glass comprising two glass sheets and a laminated glass interlayer of the invention arranged between the two glass sheets. Since the laminated glass of the present invention has the laminated glass intermediate film made of the resin sheet, it can have excellent transparency and excellent adhesiveness between the intermediate film and the glass.

Examples of the glass plate to be laminated with the interlayer film of the present invention include inorganic glass such as float glass, polished plate glass, figured glass, wired plate glass, and heat-absorbing plate glass, as well as conventionally known organic glass such as polymethyl methacrylate and polycarbonate. Glass or the like may be used. They may be either colorless or colored. These may use 1 type and may use 2 or more types together. Moreover, the thickness of one glass plate is preferably 100 mm or less, and the thickness of the two glass plates may be the same or different.

The laminated glass of the present invention can be produced by a conventionally known method. Examples thereof include a method using a vacuum laminator device, a method using a vacuum bag, a method using a vacuum ring, and a method using a nip roll. Moreover, after crimping|bonding by the said method, the method of putting into an autoclave and further adhering is also mentioned.

When using a vacuum laminator device, for example, under a reduced pressure of 1×10 ⁻⁶ to 1×10 ⁻¹ MPa, at 60 to 200° C., especially 80 to 160° C., a glass plate, an interlayer, and any layer (for example, adhesiveness A laminated glass can be manufactured by laminating a resin layer, etc.). A method using a vacuum bag or a vacuum ring is described, for example, in ^EP ^1235683 , wherein a glass plate and a A laminated glass can be produced by laminating the intermediate film.

As an example of a manufacturing method using nip rolls, a glass plate, an intermediate film and an arbitrary layer are laminated, degassed by rolls at a temperature below the flow start temperature of the intermediate film, and then crimped at a temperature close to the flow start temperature. method of doing so. Specifically, for example, after heating to 30 to 70° C. with an infrared heater or the like, degassing with rolls, further heating to 50 to 120° C., and pressing with rolls can be mentioned.

When the laminated glass is put into an autoclave and further pressure-bonded, the operating conditions of the autoclave process are appropriately selected depending on the thickness and/or structure of the laminated glass. is preferably treated for 0.5 to 3 hours.

Since the ionomer resin composition of the present invention has high transparency, excellent thermal decomposition resistance, and high adhesiveness to glass, the laminated glass of the present invention has excellent transparency and heat resistance, and the interlayer film and the glass in the laminated glass has high adhesion.
In one embodiment of the present invention, the haze of the laminated glass when the sheet thickness of the interlayer is 0.8 mm is preferably 1.0% or less, more preferably 0.8% or less, and still 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 laminated glass is measured using a haze meter according to JIS K7136:2000.

In one embodiment of the present invention, the laminated glass of the present invention has excellent transparency even after being heated to 140°C and then slowly cooled from 140°C to 23°C at a rate of 0.1°C/min. After heating a laminated glass having an interlayer sheet thickness of 0.8 mm to 140° C. and slowly cooling it from 140° C. to 23° C. at a rate of 0.1° C./min, the haze (slow cooling haze) is preferably is 5.0% or less, more preferably 4.5% or less, still 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%. Slow cooling haze is also measured using a haze meter in accordance with JIS K7136:2000.

In one embodiment of the present invention, the laminated glass of the present invention preferably has a low degree of coloring and is as colorless as possible. When the sheet thickness of the interlayer film is 0.8 mm, the yellowness of the laminated glass of the present invention is preferably 2.0 or less, more preferably 1.8 or less, still more preferably 1.5 or less, and particularly preferably 1.0 or less. Since the lower the yellowness, the lower the coloring of the laminated glass, the lower limit is not particularly limited, and may be 0, for example. The yellowness is measured using a colorimetric color difference meter in accordance with JIS Z8722:2009.

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.

[Content of monomer unit of resin in Examples and Comparative Examples]
For the ionomer resin compositions or ionomer resins obtained in Examples and Comparative Examples, the (meth)acrylic acid unit (A), the neutralized (meth)acrylic acid unit (B), the ethylene unit (C), and (meth)acrylic acid ester unit (D) content was analyzed as follows.

The ionomer resin compositions or ionomer resins obtained in Examples and Comparative Examples were respectively dissolved in a mixed solvent of dehydrated toluene/dehydrated acetic acid (75/25% by mass), reacted at 100° C. for 2 hours, and then acetone/ The neutralized (meth)acrylic acid unit (B) was converted to the (meth)acrylic acid unit (A) by reprecipitation in a mixed solvent of water (80/20% by mass). Then, after thoroughly washing with water and drying, the following (1) to (3) were carried out.
(1) The component of the monomer unit constituting the resin was analyzed by pyrolysis GC-MS.
(2) The acid value of the resin was measured according to JIS K0070:1992.
(3) Using a mixed solvent of deuterated toluene and deuterated methanol, the resin was subjected to ¹ H-NMR (400 MHz, manufactured by JEOL Ltd.) measurement.
(4) In addition, the ionomer resin compositions or ionomer resins obtained in Examples and Comparative Examples were each subjected to microwave decomposition pretreatment with nitric acid, and then subjected to ICP emission spectrometry (Thermo Fisher Scientific iCAP6500Duo). , the type and amount of the metal ion of the (meth)acrylic acid neutralized product unit (B) were identified.
From the above (1), the types and structures of the (meth)acrylic acid ester unit (D) and the (meth)acrylic acid unit (A) were identified. From that information and the information in (2) and (3) above, ethylene unit (C) / (meth) acrylic acid ester unit (D) / ((meth) acrylic acid unit (A) and (meth) acrylic acid The ratio of the sum of hydrate 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.
In addition, the content of each monomer unit of the ethylene-(meth)acrylic acid ester copolymer (X) as a raw material is the same as that of the ethylene-(meth)acrylic acid ester copolymer (X) in heavy toluene or heavy THF. was dissolved and measured by ¹ H-NMR (400 MHz, manufactured by JEOL Ltd.) to calculate.
In addition, since the content of the monomer units of the resin does not change during the process of producing the resin sheet from the ionomer resin composition or the ionomer resin, the calculated content of each monomer unit of each resin is It corresponds to the content of each monomer unit in the sheet.

[Content of Salt Consisting of Strong Acid and Strong Base]
0.1 g of the ionomer resin composition or ionomer resin obtained in Examples and Comparative Examples was weighed, added with 10 mL of ultrapure water, and heated at 90° C. for 1 hour. After that, it was allowed to cool and filtered through a filter with an opening of 0.45 μm. The filtrate obtained by filtration was used as a sample liquid, and measured under the following conditions using an ion chromatograph (manufactured by Shimadzu Corporation). Chloride ions or sulfate ions were quantified from the peak area obtained by the measurement, and the amount of the chloride ions or sulfate ions was converted to the amount of sodium salt to determine the salt content.
(Measurement condition)
Eluent: mixed solution of sodium carbonate aqueous solution (0.6 mmol/L) and sodium hydrogencarbonate aqueous solution (12 mmol/L);
Flow rate: 1.0 mL/min;
Column temperature: 40°C;
Column: IC-SA2 (250L×4.0)
Since the salt content does not change in the process of producing a resin sheet from the ionomer resin composition or ionomer resin, the calculated salt content of each ionomer resin composition or ionomer resin is the same as that of each corresponding resin sheet. Corresponds to the salt content.

[Fluidity (melt flow rate (MFR))]
In accordance with JIS K7210-1:2014, the MFR of the raw material resins used in Examples and Comparative Examples and the ionomer resin compositions or ionomer resins obtained in Examples and Comparative Examples were measured. Specifically, each resin composition or each resin is melted in a cylinder and extruded from a die with a nominal hole diameter of 2.095 mm installed at the bottom of the cylinder under 190 ° C. and a 2.16 kg load. The amount of resin composition or resin extruded (g/10 min) was measured.

[Heat decomposition resistance]
Thermal decomposition resistance of the ionomer resin compositions or ionomer resins obtained in Examples and Comparative Examples was evaluated according to JIS K7120:1987. Specifically, using a simultaneous differential thermal thermogravimetric analyzer TG-DTA7200 (manufactured by Hitachi High-Tech Science Co., Ltd.), each resin composition or The weight loss rate was measured when the resin was heated from 20°C to 550°C. The 1% weight reduction temperature (Td1), which is the temperature at which the weight reduction rate reaches 1% based on the weight at 200° C., was used as an index of thermal decomposition resistance.

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

[Yellowness index (YI) of resin sheet]
For each resin sheet obtained in Examples and Comparative Examples, a colorimetric color difference meter "ZE-2000" (manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure the yellowness according to JIS Z8722: 2009. .

[Contact angle of resin sheet]
Each resin sheet obtained in Examples and Comparative Examples was cut into 50 mm squares, and corona treatment was performed using a corona treatment machine (manufactured by Kasuga Denki Co., Ltd., tabletop table type treatment device (wire electrode) and high frequency power source AGF-B10S). did. In accordance with JIS K6768, the contact angle of distilled water was measured in a standard room at a temperature of 23° C. and a relative humidity of 50% using a contact angle meter (Kyowa Interface Science Co., Ltd., DropMaster 500). For Comparative Examples 1 and 2, contact angles were measured without corona treatment.

[Transparency during slow cooling (slow cooling haze)]
Each resin sheet obtained in Examples and Comparative Examples was cut into a 100 mm square, sandwiched between two float glass sheets of 100 mm square and 2.7 mm thick, and placed in a vacuum laminator (1522N manufactured by Nisshinbo Mechatronics Co., Ltd.). The vacuum laminator was evacuated at 100° C. for 1 minute, and pressed at 30 kPa for 5 minutes while maintaining the degree of vacuum and temperature to obtain a temporary bonded body. The obtained temporarily bonded body was put into an autoclave and treated at 140° C. and 1.2 MPa for 30 minutes to obtain laminated glass.
After heating the obtained laminated glass to 140° C., it was gradually cooled to 23° C. at a rate of 0.1° C./min. The haze of the laminated glass after slow cooling was measured using a haze meter HZ-1 (manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7136:2000.

[Adhesion to glass]
The resin sheets obtained in Examples and Comparative Examples were sandwiched between two sheets of float glass having a thickness of 2.7 mm, and placed in a vacuum laminator (1522N manufactured by Nisshinbo Mechatronics Co., Ltd.). The vacuum laminator was evacuated at 100° C. for 1 minute, and pressed at 30 kPa for 5 minutes while maintaining the degree of vacuum and temperature to obtain a temporary bonded body. The obtained temporarily bonded body was put into an autoclave and treated at 140° C. and 1.2 MPa for 30 minutes to obtain laminated glass.
Then, the obtained laminated glass was cut into a size of 25 mm×25 mm to obtain a test sample. The resulting test samples were evaluated by the Compressive shear strength test described in WO 1999/058334. The maximum shear stress when the laminated glass was peeled was taken as an index of the adhesion to glass.
In addition, when measuring the adhesiveness to the tin surface of the glass, laminated glass is prepared so that the tin surfaces of two float glasses are in contact with both sides of the resin sheet, and the adhesiveness to the air surface of the glass is measured. prepared a laminated glass so that the air surfaces of two float glasses were in contact with both sides of the resin sheet.

[Raw material resin]
Methyl methacrylate (MMA) modified amount or ethyl acrylate (EA) modified amount of each ethylene-(meth)acrylic acid ester copolymer (X) used as a raw material for the ionomer resin in Examples and Comparative Examples, and MFR are shown in Table 1.
As EMMA1, "Aclift" (registered trademark) WH401F manufactured by Sumitomo Chemical Co., Ltd. was used, and as EEA1, "Rexpearl" (registered trademark) A4250 manufactured by Japan Polyethylene Co., Ltd. was used.

[Example 1]
100 parts by mass of EMMA2 shown in Table 1 was introduced into a SUS pressure vessel, 233 parts by mass of toluene was added thereto, and the mixture was stirred at 60° C. under a pressure of 0.02 MPa to dissolve EMMA2. 100 parts by mass of a methanol solution of sodium hydroxide (20% by mass) was added to the resulting solution and stirred at 100°C for 4 hours to saponify EMMA2 to convert part of the methyl methacrylate units into sodium methacrylate units. Converted. Next, after cooling this solution to 50° C., 83 parts by mass of hydrochloric acid (20% by mass) is added and stirred at 50° C. for 1 hour to convert a part of the sodium methacrylate units to methacrylic acid, resulting in a crude ionomer. A solution containing the resin was obtained.
A mixed solvent of toluene/methanol (75/25 mass %) was added to the obtained solution so that the concentration of the crude ionomer resin was 10 mass % to dilute the solution. Next, after adjusting the diluted solution containing the obtained crude ionomer resin to 34° C., 430 parts by mass of methanol at 34° C. is added to the diluted solution with respect to 100 parts by mass of the solution containing the crude ionomer resin, Granules containing ionomer resin were precipitated. Next, after filtering the obtained granular material, 100 parts by mass of the filtered granular material and 600 parts by mass of a mixed solvent of water/methanol (50/50% by mass) were mixed. The slurry obtained by the above mixing was stirred at 40° C. for 1 hour, after which the granules were collected by filtration at room temperature. After washing the granules with a mixed solvent of water/methanol (50/50% by mass) three more times, the granules were vacuum-dried for 8 hours or longer. The particulate ionomer resin composition comprising ionomer resin and salt thus obtained was analyzed and its properties were evaluated. Table 2 shows the analysis results and evaluation results.
Next, the resulting ionomer resin composition was melt-kneaded at 210°C, and the melt-kneaded product was compression-molded for 5 minutes under heating at 210°C under a pressure of 4.9 MPa (50 kgf/cm ² ) to obtain a thickness. A resin sheet of 0.8 mm was obtained. Both surfaces of the obtained resin sheet were subjected to corona treatment at an output of 0.31 kW and a feed rate of 7.9 m/s, and the contact angles on both surfaces of the resin sheet were measured. Table 2 shows the contact angle.
Subsequently, a laminated glass was produced using the obtained resin sheet and evaluated. Table 2 shows the evaluation results.

[Example 2]
EMMA3 was used instead of EMMA2, 95 parts by weight of nitric acid (30% by weight) was used instead of 83 parts by weight of hydrochloric acid (20% by weight), and the temperature of the dilute solution containing the crude ionomer resin and methanol was increased from 34°C to 37°C. An ionomer resin composition was obtained, analyzed and evaluated in the same manner as in Example 1 except that the composition was changed. A resin sheet was prepared in the same manner as in Example 1 except that the obtained ionomer resin composition was used, and corona treatment was performed in the same manner as in Example 1 except that the feed speed was changed to 2.6 m/s. and measured the contact angle. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Example 3]
An ionomer resin composition 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 40°C, and analyzed and evaluated. went. A resin sheet was prepared in the same manner as in Example 1 except that the obtained ionomer resin composition was used, and corona treatment was performed in the same manner as in Example 1 except that the feed rate was changed to 1.3 m/s. and measured the contact angle. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Example 4]
EEA1 was used instead of EMMA2, 147 parts by weight of sulfuric acid (30% by weight) was used instead of 83 parts by weight of hydrochloric acid (20% by weight), and the temperature of the diluted solution containing the crude ionomer resin and methanol was increased from 34°C to 40°C. An ionomer resin composition was obtained, analyzed and evaluated in the same manner as in Example 1 except that the composition was changed. A resin sheet was prepared in the same manner as in Example 1 except that the obtained ionomer resin composition was used, and corona treatment was performed in the same manner as in Example 1 except that the feed speed was changed to 2.6 m/s. and measured the contact angle. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Example 5]
Using EMMA1 instead of EMMA2, changing the amounts of methanol solution of sodium hydroxide (20% by mass) and hydrochloric acid (20% by mass) to 80 parts by mass and 66 parts by mass, respectively, the concentration of the dilute solution containing the crude ionomer resin was changed from 10% by mass to 6% by mass, and the temperature of the diluted solution containing the crude ionomer resin and methanol was changed from 34°C to 41°C to obtain an ionomer resin composition, Analyzed and evaluated. A resin sheet was produced in the same manner as in Example 1 except that the obtained ionomer resin composition was used, corona treatment was performed, and the contact angle was measured. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Example 6]
An ionomer resin composition was obtained in the same manner as in Example 1, except that EMMA3 was used instead of EMMA2, and the temperature of the dilute solution containing the crude ionomer resin and methanol was changed from 34°C to 41°C, and analyzed and evaluated. went. A resin sheet was prepared in the same manner as in Example 1 except that the obtained ionomer resin composition was used, and corona treatment was performed in the same manner as in Example 1 except that the feed rate was changed to 1.3 m/s. and measured the contact angle. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Example 7]
EMMA3 was used instead of EMMA2, 147 parts by weight of sulfuric acid (30% by weight) was used instead of 83 parts by weight of hydrochloric acid (20% by weight), and the temperature of the diluted solution containing the crude ionomer resin and methanol was increased from 34°C to 41°C. An ionomer resin composition was obtained, analyzed and evaluated in the same manner as in Example 1 except that the composition was changed. A resin sheet was produced in the same manner as in Example 1 except that the obtained ionomer resin composition was used, and the feeding speed was changed to 1.3 m / s, and the number of treatments was changed to 2 times. Corona treatment was performed in the same manner as in Example 1, and the contact angle was measured. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Comparative Example 1]
In the same manner as in Example 1, except that EMMA1 was used instead of EMMA2, and the amounts of sodium hydroxide methanol solution (20% by mass) and hydrochloric acid (20% by mass) were changed to 80 parts by mass and 66 parts by mass, respectively. , an ionomer resin composition was obtained and analyzed and evaluated. A resin sheet was produced in the same manner as in Example 1 except that the obtained ionomer resin composition was used, and the contact angle was measured without corona treatment. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Comparative Example 2]
An ionomer resin composition was obtained in the same manner as in Example 1, except that EMMA3 was used instead of EMMA2, and the temperature of the dilute solution containing the crude ionomer resin and methanol was changed from 34°C to 37°C, and the composition was analyzed and evaluated. went. A resin sheet was produced in the same manner as in Example 1 except that the obtained ionomer resin composition was used, and the contact angle was measured without corona treatment. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Comparative Example 3]
EMMA4 was used in place of EMMA2, and the amounts of methanol solution of sodium hydroxide (20% by mass) and hydrochloric acid (20% by mass) were changed to 72 parts by mass and 59 parts by mass, respectively, and a dilute solution containing crude ionomer resin and methanol An ionomer resin composition was obtained, analyzed and evaluated in the same manner as in Example 1, except that the temperature was changed from 34°C to 40°C. A resin sheet was produced in the same manner as in Example 1 except that the obtained ionomer resin composition was used, corona treatment was performed, and the contact angle was measured. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Comparative Example 4]
EMMA3 was used instead of EMMA2, 95 parts by weight of nitric acid (30% by weight) was used instead of 83 parts by weight of hydrochloric acid (20% by weight), and the temperature of the diluted solution containing the crude ionomer resin and methanol was increased from 34°C to 40°C. An ionomer resin composition was obtained, analyzed and evaluated in the same manner as in Example 1 except that the composition was changed. A resin sheet was produced in the same manner as in Example 1, except that the obtained ionomer resin composition was used. Corona treatment was performed in the same manner as in Example 1, except that the feeding speed was changed to 1.3 m/s and the number of treatments was changed to 10 times, and the contact angle was measured. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Comparative Example 5]
In the same manner as in Example 1, except that EMMA1 was used instead of EMMA2, and the amounts of sodium hydroxide methanol solution (20% by mass) and hydrochloric acid (20% by mass) were changed to 80 parts by mass and 66 parts by mass, respectively. , an ionomer resin composition was obtained and analyzed and evaluated. A resin sheet was produced in the same manner as in Example 1, except that the obtained ionomer resin composition was used. Corona treatment was performed in the same manner as in Example 1, except that the feeding speed was changed to 1.3 m/s and the number of treatments was changed to 5 times, and the contact angle was measured. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Comparative Example 6]
EMMA3 was used instead of EMMA2, 147 parts by weight of sulfuric acid (30% by weight) was used instead of 83 parts by weight of hydrochloric acid (20% by weight), and the temperature of the diluted solution containing the crude ionomer resin and methanol was increased from 34°C to 43°C. An ionomer resin composition was obtained, analyzed and evaluated in the same manner as in Example 1 except that the composition was changed. A resin sheet was produced in the same manner as in Example 1, except that the obtained ionomer resin composition was used. Corona treatment was performed in the same manner as in Example 1, except that the feeding speed was changed to 1.3 m/s, and the contact angle was measured. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2.

[Comparative Example 7]
Using EMMA3 instead of EMMA2, using 95 parts by mass of nitric acid (30% by mass) instead of 83 parts by mass of hydrochloric acid (20% by mass), and washing the granules with a mixed solvent of water/methanol (50/50% by mass). An ionomer resin composition was obtained, analyzed and evaluated in the same manner as in Example 1 except that the above was performed 6 times. A resin sheet was produced in the same manner as in Example 1, except that the obtained ionomer resin composition was used. Corona treatment was performed in the same manner as in Example 1, except that the feed speed was changed to 2.6 m/s, and the contact angle was measured. Furthermore, a laminated glass was produced and evaluated in the same manner as in Example 1 except that the obtained resin sheet was used. Those results are shown in Table 2. In addition, "N.D." in Table 2 means that it was not detected, and the salt content was less than 1 mg/kg.

As shown in Table 2, it was confirmed that the resin sheets obtained in Examples 1 to 7 had excellent transparency as well as excellent adhesiveness to glass. In addition, it was confirmed that the adhesiveness to glass is excellent not only to the tin surface but also to the air surface.
On the other hand, the resin sheets obtained in Comparative Examples 1 to 5 are inferior in adhesiveness to glass, particularly to air surfaces, and the resin sheet obtained in Comparative Example 3 is transparent when slowly cooled. It was also inferior in sex. The resin sheet obtained in Comparative Example 6 was inferior in transparency when absorbing water. The resin sheet obtained in Comparative Example 7 was inferior in thermal decomposition resistance, and although the contact angle satisfies the specific range of the present invention, the adhesiveness to glass, particularly to the air surface, was poor. was inferior.

Since the resin sheet of the present invention has properties of high transparency and excellent adhesion to glass, it can be used as an interlayer film for laminated glass, for example, for architectural and structural applications (for example, laminates for facades, exterior walls or roofs, panels Building materials such as doors, windows, walls, roofs, sunroofs, sound insulation walls, display windows, balconies, handrails, partition glass members for conference rooms, solar panels, etc.), or laminated glass for vehicles ( For example, it can be suitably used as an intermediate film for automobile windshields, automobile side glasses, automobile sunroofs, automobile rear glasses, head-up display glasses, etc.). In addition, the laminated glass of the present invention can be suitably used as laminated glass for architectural/structural use or vehicle use.

Claims

A resin sheet having one or more layers comprising an ionomer resin composition,
The layer containing the ionomer resin composition forms at least one surface of the resin sheet,
The contact angle of the surface measured in accordance with JIS K6768 is 60 to 75 degrees,
The ionomer resin composition comprises an ionomer resin containing (meth)acrylic acid units (A), (meth)acrylic acid neutralized units (B), and ethylene units (C), and a salt composed of a strong acid and a strong base. comprising
The total content of the units (A) and the units (B) is 6 to 10 mol% based on the total monomer units constituting the ionomer resin,
The resin sheet, wherein the content of the salt is 1 to 400 mg/kg based on the total mass of the ionomer resin composition.
The layer comprising the ionomer resin composition forms both surfaces of the resin sheet,
The contact angles of both surfaces measured in accordance with JIS K6768 are 60 to 75 degrees.
The resin sheet according to claim 1.
The ionomer resin further contains (meth)acrylic acid ester units (D), and the total content of the units (A), the units (B) and the units (D) is the total amount of monomers constituting the ionomer resin. 3. The resin sheet according to claim 1, which is 6 to 10 mol % based on the body unit.
The resin sheet according to any one of claims 1 to 3, wherein the salt is a metal salt of alkali metal and/or alkaline earth metal.
The salt 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. The resin sheet according to any one of claims 1 to 4.
A laminated glass intermediate film made of the resin sheet according to any one of claims 1 to 5.
A laminated glass comprising two glass plates and the laminated glass intermediate film according to claim 6 arranged between the two glass plates.