US-12617885-B2 - Ionomer resin, resin sheet, and laminated glass

US12617885B2US 12617885 B2US12617885 B2US 12617885B2US-12617885-B2

Abstract

The present invention relates to an ionomer resin, comprising a (meth)acrylic acid unit (A), a neutralized (meth)acrylic acid unit (B) and an ethylene unit (C), wherein a total content of the unit (A) and the unit (B) is 6 to 10% by mole based on all monomer units constituting the ionomer resin, and the content of a transition metal in the ionomer resin is 0.01 to 100 mg/kg.

Inventors

Takuro Niimura
Kenta TAKEMOTO
Atsuhiro Nakahara
Yoshiaki Asanuma

Assignees

KURARAY EUROPE GMBH

Dates

Publication Date: 20260505
Application Date: 20210922
Priority Date: 20200929

Claims (10)

1 . An ionomer resin, comprising: a (meth)acrylic acid unit (A); a neutralized (meth)acrylic acid unit (B); and an ethylene unit (C), wherein a total content of the unit (A) and the unit (B) is 6 to 10% by mole based on all monomer units constituting the ionomer resin, and the content of a transition metal in the ionomer resin is 0.01 to 100 mg/kg.
2 . The ionomer resin according to claim 1 , further comprising a (meth)acrylic acid ester unit (D), wherein a total content of the unit (A), the unit (B), and the unit (D) is 6 to 10% by mole based on all monomer units constituting the ionomer resin.
3 . The ionomer resin according to claim 1 , wherein the transition metal is at least one metal selected from the group consisting of iron, nickel, manganese, and chromium.
4 . A resin sheet, comprising at least one layer comprising the ionomer resin according to claim 1 .
5 . A laminated glass intermediate film, consisting of the resin sheet according to claim 4 .
6 . A laminated glass, comprising: two glass plates; and the laminated glass intermediate film according to claim 5 , which is arranged between the two glass plates.
7 . A method of producing the ionomer resin according to claim 1 , the method comprising: saponifying an ethylene-(meth)acrylic acid ester copolymer with a strong base; and demetallizing a saponification product obtained by the saponifying with a strong acid, wherein the saponifying and/or the demetallizing is/are performed in the presence of a transition metal.
8 . The method according to claim 7 , wherein the demetallizing is performed by intra-liquid addition of the strong acid to a solution of the saponification product.
9 . A method of producing an ionomer resin, the method comprising: saponifying an ethylene-(meth)acrylic acid ester copolymer with a strong base; and demetallizing a saponification product obtained by the saponifying with a strong acid, wherein the saponifying and/or the demetallizing is/are performed in the presence of a transition metal, wherein: the saponifying and/or the demetallizing is/are performed using a reaction apparatus, and at least a portion of the reaction apparatus is formed of an alloy comprising nickel and chromium as transition metals in a total amount of not less than 50% by mass, and wherein the ionomer resin comprises: a (meth)acrylic acid unit (A); a neutralized (meth)acrylic acid unit (B); and an ethylene unit (C), wherein a total content of the unit (A) and the unit (B) is 6 to 10% by mole based on all monomer units constituting the ionomer resin, and the content of a transition metal in the ionomer resin is 0.01 to 100 mg/kg.
10 . The method according to claim 9 , wherein the at least a portion of the reaction apparatus is at least a portion selected from the group consisting of a reaction vessel, a stirring blade, a baffle, and a feed line through which the strong base and/or the strong acid is/are supplied to the reaction vessel.

Description

TECHNICAL FIELD This patent application claims priority under the Paris Convention based on Japanese Patent Application No. 2020-163733 (filed on Sep. 29, 2020), which is incorporated herein by reference in its entirety. The present invention relates to: an ionomer resin; a method of producing the same; a resin sheet that includes at least one layer containing the ionomer resin; a laminated glass intermediate film that consists of the resin sheet; and a laminated glass that includes the laminated glass intermediate film. BACKGROUND ART Ionomers, which are neutralization products of ethylene-unsaturated carboxylic acid copolymers, are used in intermediate films of laminated glass because of their excellent transparency and adhesion with glass (e.g., Patent Literature 1). In recent years, with the increasing performance requirements for laminated glass, ionomer resins are also demanded, for example, to keep high transparency regardless of the production conditions of laminated glass; to maintain a high elastic modulus and not to cause a reduction in the strength of laminated glass even at a high temperature; to have excellent appearance with less coloring; and to exhibit superior adhesion with glass and to be hardly peelable from glass. Patent Literature 2 discloses a polymeric sheet which includes at least one layer containing an ionomer or ionomer blend incorporating a partially neutralized α,β-ethylenically unsaturated carboxylic acid, wherein the ionomer or ionomer blend contains ions of one or more monovalent metals in an amount of about 1% to about 60%, and ions of one or more polyvalent metals in an amount of about 40% to about 99%, based on a total amount of neutralization of the α,β-ethylenically unsaturated carboxylic acid. Patent Literature 3 discloses a resin composition containing an ionomer resin and an adhesion promoter, wherein the adhesion promoter is a dialkoxysilane compound. CITATION LIST Patent Literature Patent Literature 1: U.S. Pat. No. 6,432,522 B1 Patent Literature 2: JP 2009-512763 A Patent Literature 3: WO 2019/027865 A1 SUMMARY OF INVENTION Technical Problem When a laminated glass is used outdoors, there are cases where, due to the moisture from rain and the like, peeling occurs between glass and an intermediate film of the laminated glass and the transparency is reduced by whitening, particularly at the edges of the laminated glass. Therefore, there is a demand for an ionomer resin which can form a laminated glass intermediate film that has high transparency and exhibits high adhesion with glass even under high-humidity conditions. Patent Literature 2 discloses that the ionomer or ionomer blend disclosed therein exhibits synergistically improved glass adhesion. However, according to the studies conducted by the present inventors, it was found that, under high-humidity conditions, the ionomer disclosed in Patent Literature 2 can tend to delaminate from glass and thus have insufficient adhesion to the glass, in addition to a tendency to whiten and have less transparency. Patent Literature 3 discloses that the resin composition disclosed therein exhibits high adhesion with glass even under high-humidity conditions. However, according to the studies conducted by the present inventors, it was found that the resin composition disclosed in Patent Literature 3 is likely to generate a crosslinked gel during forming process, and needs further improvement to obtain therefrom a resin sheet having a good appearance. In view of the above, an object of the present invention is to provide: an ionomer resin from which a sheet that not only has high transparency and exhibits high adhesion with a substrate such as glass even under high-humidity conditions but also has a good appearance can be formed; and a method of producing the same. Solution to Problem The present inventors intensively studied to solve the above-described problems, and thereby arrived at the present invention. That is, the present invention provides the following preferred embodiments. [1] An ionomer resin, comprising: a (meth)acrylic acid unit (A);a neutralized (meth)acrylic acid unit (B); andan ethylene unit (C),whereina total content of the unit (A) and the unit (B) is 6 to 10% by mole based on all monomer units constituting the ionomer resin, andthe content of a transition metal in the ionomer resin is 0.01 to 100 mg/kg. [2] The ionomer resin according to [1], further comprising a (meth)acrylic acid ester unit (D), wherein a total content of the unit (A), the unit (B), and the unit (D) is 6 to 10% by mole based on all monomer units constituting the ionomer resin. [3] The ionomer resin according to [1] or [2], wherein the transition metal is at least one metal selected from the group consisting of iron, nickel, manganese, and chromium. [4] A resin sheet, comprising at least one layer comprising the ionomer resin according to any one of [1] to [3]. [5] A laminated glass intermediate film, consisting of the resin sheet accordin