WO2022265078A1

WO2022265078A1 - Polyvinyl acetal resin film

Info

Publication number: WO2022265078A1
Application number: PCT/JP2022/024196
Authority: WO
Inventors: 尚輝鴨志田; 裕司大東; 祐美子寺口; 由貴石川
Original assignee: 積水化学工業株式会社
Priority date: 2021-06-18
Filing date: 2022-06-16
Publication date: 2022-12-22
Also published as: TW202313828A; JPWO2022265078A1

Abstract

A polyvinyl acetal resin film according to the present invention contains a component having a polyoxyalkylene group, contains 10-10,000 mass ppm of at least one antioxidant having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure, and has an increase in the total concentration of an aldehyde with at most 8 carbon atoms of at most 100 mass ppm after being heated for 5 hours at 130°C in a sealed container.　With the present invention it is possible to provide a polyvinyl acetal resin film in which yellowing of the film, generation of an aldehyde odor, and deterioration of the polyvinyl acetal resin are inhibited, even if the film has been exposed to high temperatures.

Description

Polyvinyl acetal resin film

The present invention relates to a polyvinyl acetal resin film.

Polyvinyl acetal-based resin films are widely used as interlayer films for laminated glass. Laminated glass includes two glass plates and an interlayer film for laminated glass disposed between the two glass plates, and the two glass plates are integrated by the interlayer film for laminated glass. Laminated glass is widely used in automobiles, railroad vehicles, aircraft, ships, buildings, etc., because it is excellent in safety because the amount of scattered glass fragments is small even if it is broken by an external impact.

The polyvinyl acetal resin film contains a polyvinyl acetal resin and, if necessary, a plasticizer. When these polyvinyl acetal-based resins and plasticizers have a polyoxyalkylene group, the flexibility of the film is improved, and the workability and adhesion to organic glass are improved.
However, when a component having a polyoxyalkylene group is contained in the film, the thermal stability is lowered, and problems such as yellowing of the film when exposed to high temperatures, generation of aldehyde odor, and deterioration of the resin tend to occur. Become.

In addition, the interlayer film for laminated glass is exposed to high temperatures of about 60 to 150°C when it is laminated and adhered to glass to form laminated glass. Furthermore, in the environment in which laminated glass is used, it may be exposed to temperatures of about 50 to 70° C. for a long period of time. Therefore, a polyvinyl acetal resin film used as an interlayer film for laminated glass is required to be less likely to cause defects such as yellowing, generation of aldehyde odor, and resin deterioration, and to have excellent thermal stability.

Various studies have been made for the purpose of reducing yellowing and odor as described above.
Patent Document 1 describes an invention relating to an interlayer film for laminated glass having a total amount of volatile substances of 30 ppm or less after standing at 100° C. for 1 hour. Patent Document 2 describes an invention relating to a fiber containing polyvinyl butyral having a butyralization degree of 50 to 90% by mass and a butyraldehyde content of 20 mass ppm or less.
Patent Document 3 describes an invention relating to a sheet containing certain amounts of polyvinyl acetal, a plasticizer, and a specific ultraviolet absorber, and describes the use of an antioxidant with a specific structure. Patent Document 4 describes an invention relating to a polyvinyl acetal resin for heat-developable photosensitive materials, in which the degree of polymerization, the amount of residual acetyl groups, the amount of residual hydroxyl groups, and the amount of water are within specific ranges, and the residual aldehyde content is 10 ppm or less. It is

JP-A-2001-72445 WO2014/157080 JP 2015-214692 A Japanese Patent Application Laid-Open No. 2002-201215

However, Patent Document 1 described above does not consider reduction of volatile matter at 100° C. or higher, and Patent Document 2 does not describe reduction in the concentration of aldehydes other than butyraldehyde. Further, these Patent Documents 1 and 2 are intended to reduce odor and do not disclose a method for preventing resin deterioration. Further, Patent Document 3 does not disclose the reduction of aldehyde concentration, and Patent Documents 3 and 4 do not disclose a method for preventing resin deterioration when exposed to high temperatures.
In addition, these Patent Documents 1 to 4 describe a method for effectively preventing yellowing of the film, generation of aldehyde odor, and deterioration of the resin, which are likely to occur when a component having a polyoxyalkylene group is contained. not even suggested.

Accordingly, the present invention provides a polyvinyl acetal-based resin film containing a component having a polyoxyalkylene group, which prevents yellowing of the film, generation of an aldehyde odor, and reduction of the polyvinyl acetal-based resin film even when exposed to high temperatures. An object of the present invention is to provide a polyvinyl acetal-based resin film in which resin deterioration is suppressed.

As a result of extensive studies, the present inventors have found that a film containing a component having a polyoxyalkylene group, containing a specific amount of an antioxidant having a specific partial structure, and aldehyde after heating under specific conditions The inventors have found that the above problems can be solved by a polyvinyl acetal-based resin film in which the amount of increase in the total concentration of is less than a certain value, and have completed the following invention.
That is, the present invention provides the following [1] to [12].
[1] Containing a component having a polyoxyalkylene group and containing 10 to 10000 ppm by mass of at least one antioxidant having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure A polyvinyl acetal-based resin film having a total concentration increase of 100 mass ppm or less of aldehydes having 8 or less carbon atoms after heating at 130° C. for 5 hours in a sealed container.
[2] The polyvinyl acetal resin film according to [1] above, wherein the component having a polyoxyalkylene group is a polyvinyl acetal resin having a polyoxyalkylene group or a plasticizer having a polyoxyalkylene group.
[3] The polyvinyl acetal resin film according to [1] or [2] above, wherein the polyoxyalkylene group is linked to the main chain of the polyvinyl acetal resin.
[4] The polyvinyl acetal resin film according to any one of [1] to [3] above, wherein the polyoxyalkylene group is a group having a repeating unit of an oxyalkylene group having 2 to 4 carbon atoms.
[5] The polyvinyl according to any one of [1] to [4] above, wherein the repeating unit of the polyoxyalkylene group is at least one selected from the group consisting of an oxyethylene group and an oxypropylene group. Acetal resin film.
[6] The polyvinyl acetal-based resin film according to any one of [1] to [5] above, wherein the polyoxyalkylene content is 5 to 50 parts by mass with respect to 100 parts by mass of the unmodified polyvinyl acetal moiety.
[7] The polyvinyl acetal-based resin having a polyoxyalkylene group has at least one functional group selected from the following formulas (1-1) to (1-2), [2] to The polyvinyl acetal resin film according to any one of [6].

(In formulas (1-1) and (1-2), A ¹ O and A ² O are each independently an oxyalkylene group having 2 to 4 carbon atoms; 200. R ³ and R ⁴ are each independently an alkyl group having 1 to 4 carbon atoms or a hydrogen atom.)
[8] The plasticizer having a polyoxyalkylene group is at least one selected from the group consisting of polyalkylene glycol-based plasticizers, polyoxyalkylene ether-based plasticizers, and monobasic organic acid esters. [2] The polyvinyl acetal resin film according to any one of [7].
[9] The polyvinyl acetal-based resin film according to any one of [1] to [8] above, wherein the antioxidant contains an antioxidant represented by the following formula (I).

In the above formula (I), R is an organic group having 1 to 100 carbon atoms, and the organic group may have at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom. .
[10] The polyvinyl acetal resin film according to any one of [1] to [9] above, wherein the antioxidant has a molecular weight of 1000 or more.
[11] An interlayer film for laminated glass, comprising the film according to any one of [1] to [10] above.
[12] An intermediate film for laminated glass according to [11] above, and first and second laminated glass members, wherein the laminated glass intermediate film is disposed between the first and second laminated glass members. Laminated glass.

According to the present invention, it is possible to provide a polyvinyl acetal-based resin film that suppresses yellowing of the film and the generation of aldehyde odor even when exposed to high temperatures, and that the polyvinyl acetal-based resin is less likely to deteriorate.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view schematically showing an interlayer film for laminated glass and laminated glass including the interlayer film for laminated glass according to one embodiment of the present invention.

[Polyvinyl acetal resin film]
The polyvinyl acetal resin film of the present invention contains a component having a polyoxyalkylene group and at least one antioxidant having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure. Contains 10 to 10000 mass ppm. Furthermore, in the polyvinyl acetal resin film of the present invention, the increase in the total concentration of aldehydes having 8 or less carbon atoms after heating in a sealed container at 130° C. for 5 hours is 100 mass ppm or less.
The polyvinyl acetal-based resin film is a film containing polyvinyl acetal-based resin as a main component (for example, 50% by mass or more).

<Amount of increase in total concentration of aldehyde>
The polyvinyl acetal-based resin film of the present invention has an increase in the total concentration of aldehydes having 8 or less carbon atoms of 100 mass ppm or less after heating at 130° C. for 5 hours in a sealed container. If the increase in the total concentration of aldehydes having 8 or less carbon atoms exceeds 100 ppm by mass, the odor caused by the aldehydes increases, the film yellows, and the polyvinyl acetal resin tends to deteriorate. Therefore, from the viewpoint of preventing such problems more effectively, the increase in the total concentration of the aldehydes having 8 or less carbon atoms is preferably 80 mass ppm or less, more preferably 50 mass ppm or less. The total concentration of aldehydes having 8 or less carbon atoms in the polyvinyl acetal-based resin film can be easily reduced by using a specific antioxidant to be described later.
The aldehyde having 8 or less carbon atoms may be a saturated aldehyde having 8 or less carbon atoms or may be an unsaturated aldehyde, such as formaldehyde, acetaldehyde, propionaldehyde, acrolein, butyraldehyde, crotonaldehyde, glutar Aldehyde, 2-ethylhexylaldehyde, furfural and the like can be mentioned.

The amount of increase in the total concentration of aldehydes having 8 or less carbon atoms is obtained by the following formula (1).
Formula (1) (Total concentration of aldehydes with 8 or less carbon atoms contained in polyvinyl acetal resin film after heating at 130 ° C. for 5 hours in a sealed container) - (To polyvinyl acetal resin film before heating Total concentration of aldehydes containing 8 or less carbon atoms)
As a container used for the test, a glass container with a capacity of 10 cm ³ is preferably used.
The total concentration of aldehydes having 8 or less carbon atoms is the total concentration of individual aldehydes having 8 or less carbon atoms present in the polyvinyl acetal resin film, and is measured by high performance liquid chromatography (HPLC).

<Antioxidant>
The polyvinyl acetal resin film of the present invention contains at least one antioxidant having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure. By using an antioxidant with such a specific structure, it becomes easier to suppress the thermal deterioration of the component having a polyoxyalkylene group. It becomes easy to suppress deterioration of resin.

As the antioxidant having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure, an antioxidant represented by the following formula (I) is preferable.

In the above formula (I), R is an organic group having 1 to 100 carbon atoms, and the organic group may have at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom. .
The portion of the above formula (I) excluding R is (3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

In the above formula (I), from the viewpoint of suppressing thermal deterioration of the component having a polyoxyalkylene group, R is an alkyl group having 4 to 30 carbon atoms, or 1 to 3 (3,5-di-tert -Butyl-4-hydroxyphenyl)propionate and an organic group having 15 to 60 carbon atoms which may have a sulfur atom.
Among them, from the viewpoint of suppressing thermal deterioration of a component having a polyoxyalkylene group, the antioxidant is preferably an antioxidant having the structure of the following formulas (I-1) to (I-4), and the formula (I-1 ) are particularly preferred. Note that iC ₈ H ₁₇ in formula (I-4) represents an isooctyl group.

The antioxidants represented by formulas (I-1) to (I-4) are commercially available as Irganox 1010, Irganox 1035, Irganox 1076 and Irganox 1135 (all of which are manufactured by BASF Japan Ltd.).

The antioxidant having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure used in the present invention preferably has a molecular weight of 1000 or more. By using an antioxidant having a molecular weight of 1000 or more, it is possible to effectively prevent thermal deterioration of the component having a polyoxyalkylene group. Examples of the antioxidant having a molecular weight of 1000 or more include the antioxidant represented by formula (I-1) described above.

The content of the antioxidant having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure in the polyvinyl acetal resin film is 10 to 10000 mass ppm. If it is less than 10 ppm by mass, it becomes difficult to suppress thermal deterioration of the component having a polyoxyalkylene group. On the other hand, if it exceeds 10000 ppm by mass, it becomes difficult to obtain the effect corresponding to the amount of the antioxidant added. The content of the antioxidant in the polyvinyl acetal-based resin film is preferably 100 to 10000 mass ppm, more preferably 500 to 8000 mass ppm, still more preferably 1000 to 7000 mass ppm.

<Component having a polyoxyalkylene group>
The polyvinyl acetal-based resin film of the present invention contains a component having a polyoxyalkylene group. Containing a component having a polyoxyalkylene group improves the flexibility of the polyvinyl acetal film, and further improves workability and adhesion to organic glass when used as an interlayer film for laminated glass. Such a component having a polyoxyalkylene group is likely to cause thermal deterioration, yellowing, aldehyde odor generation, and resin deterioration. Since it contains, such a problem can be suppressed.
The polyoxyalkylene group is preferably a group having repeating units of oxyalkylene groups having 2 to 4 carbon atoms. More preferably, the repeating unit of the polyoxyalkylene group is at least one selected from the group consisting of an oxyethylene group and an oxypropylene group.

The component having a polyoxyalkylene group may be a polyvinyl acetal resin having a polyoxyalkylene group, or a compound other than a polyvinyl acetal resin having a polyalkylene group.
The component having a polyoxyalkylene group is preferably a polyvinyl acetal resin having a polyoxyalkylene group or a plasticizer having a polyoxyalkylene group.

(Polyvinyl acetal resin having polyoxyalkylene group)
A polyvinyl acetal resin having a polyoxyalkylene group has excellent flexibility. Therefore, a film containing a polyvinyl acetal-based resin having a polyoxyalkylene group tends to have a low glass transition temperature even when it does not contain a plasticizer, thereby improving workability and adhesion to organic glass.
The polyoxyalkylene group of the polyvinyl acetal-based resin having a polyoxyalkylene group is preferably linked to the main chain of the polyvinyl acetal-based resin via either an ether bond or —CH ₂ O— linking group. It is preferably linked to the main chain. In addition, -CH ₂ O- preferably has a carbon atom linked to the main chain.

More specifically, the polyvinyl acetal resin having a polyoxyalkylene group preferably has at least one functional group selected from the following formulas (1-1) and (1-2).

(In formulas (1-1) and (1-2), A ¹ O and A ² O are each independently an oxyalkylene group having 2 to 4 carbon atoms; 200. R ³ and R ⁴ are each independently an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and two or more types of oxyalkylene groups, for example, an oxyethylene group and an oxypropylene group, may be mixed. may be present.)

In formulas (1-1) and (1-2), A ¹ O and A ² O are each independently an oxyalkylene group having 2 to 4 carbon atoms. The oxyalkylene group having 2 to 4 carbon atoms is an oxyethylene group, an oxypropylene group or an oxybutylene group, preferably an oxyethylene group or an oxypropylene group, more preferably an oxyethylene group. Incidentally, two or more oxyalkylene groups may be used in combination, and in that case, each oxyalkylene group may be added at random or in blocks.
m and n represent the average number of repeating oxyalkylene groups, which is 4-200, preferably 4-100, more preferably 4-50, even more preferably 5-40, and particularly preferably 8-20.
Alkyl groups for R ³ and R ⁴ include methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl and t-butyl groups. R ³ and R ⁴ are each independently an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 2 carbon atoms, more preferably a methyl group or a hydrogen atom, and further A hydrogen atom is preferred.
Therefore, the functional group represented by formula (1-1) is particularly preferably the functional group represented by —O—(CH ₂ CH ₂ O) _m —H, and the functional group represented by formula (1-2) The group is particularly preferably a functional group represented by -CH ₂ O-(CH ₂ CH ₂ O) _n -H. The preferred ranges of m and n in these cases are also as described above.

The polyvinyl acetal-based resin has a structural unit derived from a vinyl group as a main chain, and the functional groups represented by formulas (1-1) to (1-2) are composed of vinyl groups that form the main chain. It is preferable that it is connected to the unit. Therefore, the polyvinyl acetal-based resin preferably has any one of structural units represented by the following formulas (2-1) and (2-2).

(In formulas (2-1) and (2-2), A ¹ O, A ² O, m, n, R ³ and R ⁴ are the same as above.)

A polyvinyl acetal-based resin typically has an acetal group, a hydroxyl group, and an acetyl group. ) and structural units represented by formula (3-3). Therefore, the polyvinyl acetal-based resin having a polyoxyalkylene group includes structural units represented by the following formulas (3-1), (3-2) and (3-3), and the above formula (2-1 ) to formula (2-2).
The formulas (2-1) and (2-2) are structural units having a polyoxyalkylene group, the formula (3-1) is a structural unit having an acetal group, and the formula (3-2) is a hydroxyl group. and formula (3-3) is a structural unit having an acetyl group.

(In formula (3-1), R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 19 carbon atoms.)

The amount of the structural unit having a polyoxyalkylene group in the polyvinyl acetal resin having a polyoxyalkylene group is preferably 1 to 30% by mass, more preferably 5 to 25% by mass, more preferably 10 to 20% by mass.
The amount of structural units having a polyoxyalkylene group means the ratio of the structural units having a polyoxyalkylene group to the total structural units of the polyvinyl acetal-based resin. The same applies to the amount of a structural unit having a hydroxyl group, the amount of a structural unit having an acetal group, and the amount of a structural unit having an acetyl group, which will be described later.
The amount of each structural unit can be calculated from the spectrum obtained by subjecting the polyvinyl acetal-based resin to proton NMR measurement.

The number of carbon atoms in the acetal group contained in the polyvinyl acetal-based resin is not particularly limited. ~6 is more preferred, and 2, 3 or 4 is even more preferred. Therefore, the number of carbon atoms in R ⁵ represented by the above formula (3-1) is preferably 1-9, more preferably 1-5, even more preferably 1-3.

Specifically, the acetal group is particularly preferably a butyral group, and therefore, the polyvinyl acetal-based resin is preferably a polyvinyl butyral-based resin.
The amount of the structural unit having an acetal group in the polyvinyl acetal resin having a polyoxyalkylene group is not particularly limited, but is, for example, 45 to 90% by mass, preferably 55 to 85% by mass, more preferably 60%. ~80% by mass. When the amount of the structural unit having an acetal group is within such a range, it becomes easier to introduce a certain amount of the structural unit having a polyoxyalkylene group.

The amount of the structural unit having a hydroxyl group in the polyvinyl acetal resin having a polyoxyalkylene group is not particularly limited, but is, for example, 0 to 35% by mass, preferably 5 to 30% by mass, more preferably 10 to 35% by mass. 25% by mass. By setting the amount of the structural unit having a hydroxyl group to these upper limits or less, the flexibility of the film is increased and the adhesiveness to organic glass is improved. On the other hand, when the amount of the structural unit having a hydroxyl group is at least these lower limits, it becomes easier to prevent the film from becoming too flexible.
The amount of the structural unit having an acetyl group in the polyvinyl acetal resin having a polyoxyalkylene group is not particularly limited, but is, for example, 0.01 to 50% by mass, preferably 0.1 to 20% by mass, More preferably, it is 0.5 to 10% by mass.

The average degree of polymerization of the polyvinyl acetal resin having a polyoxyalkylene group is preferably 300 or more and 5000 or less. By adjusting the average degree of polymerization within the above range, it becomes easier to improve adhesiveness while maintaining favorable mechanical strength, flexibility, and the like.
From these viewpoints, the average degree of polymerization of the polyvinyl acetal-based resin is more preferably 500 or more, more preferably 700 or more, and even more preferably 1200 or more from the viewpoint of easily improving the mechanical strength. In addition, the average degree of polymerization is more preferably 4500 or less, more preferably 4000 or less, and even more preferably 3500 or less from the viewpoint of easily improving adhesiveness.
The average degree of polymerization of polyvinyl acetal resin is the same as the average degree of polymerization of polyvinyl alcohol as a raw material, and can be obtained from the average degree of polymerization of polyvinyl alcohol. The average degree of polymerization of polyvinyl alcohol is determined by a method based on JIS K6726 "Polyvinyl alcohol test method".

When the polyvinyl acetal-based resin film contains a polyvinyl acetal-based resin having a polyoxyalkylene group, the content of the polyvinyl acetal-based resin having a polyoxyalkylene group is preferably 20% by mass or more, more preferably 50% by mass. It is at least 90% by mass, more preferably at least 90% by mass. By setting the content of the polyvinyl acetal-based resin having a polyoxyalkylene group to at least these lower limit values, flexibility can be easily imparted to the film even when a plasticizer is not used.

A polyvinyl acetal resin having a polyoxyalkylene group is produced, for example, by the following method.
First, polyoxyalkylene-modified polyvinyl alcohol is produced as raw material polyvinyl alcohol. Specifically, it is obtained by polymerizing a vinyl ester and a monomer containing a vinyl monomer having a polyoxyalkylene group to obtain a polymer, and then saponifying the polymer. Alkali or acid is generally used for saponification, and alkali is preferably used.
Next, the polyoxyalkylene-modified polyvinyl alcohol obtained above is preferably acetalized with an aldehyde to obtain a polyvinyl acetal-based resin having a polyoxyalkylene group. The method of acetalization is preferably carried out by a known method.

Vinyl esters include vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl isochorate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, stearic acid. Vinyl, vinyl oleate, vinyl benzoate, and the like can be used. Among these, vinyl acetate is preferred.

Further, specific examples of vinyl monomers having a polyoxyalkylene group include polyoxyalkylene vinyl ethers represented by the following formula (4-1) and polyoxyalkylene allyl ethers represented by the following formula (4-2). be done.

(In formulas (4-1) and (4-2), A ¹ O, A ² O, m, n, R ³ and R ⁴ are the same as above.)

Preferred specific examples of vinyl monomers having a polyoxyalkylene group include polyoxyethylene monovinyl ether, polyoxyethylene polyoxypropylene monovinyl ether, polyoxypropylene monovinyl ether, polyoxyethylene monoallyl ether, polyoxyethylene polyoxypropylene mono Examples include allyl ether and polyoxypropylene monoallyl ether, and among these, polyoxyethylene monovinyl ether, polyoxyethylene monoallyl ether, polyoxypropylene monovinyl ether, and polyoxypropylene monoallyl ether are more preferable.

(Plasticizer having polyoxyalkylene group)
A plasticizer having a polyoxyalkylene group has excellent flexibility. Therefore, a film containing a plasticizer having a polyoxyalkylene group tends to have a low glass transition temperature, improving workability and adhesion to organic glass.
The plasticizer having a polyoxyalkylene group is not particularly limited as long as it is a compound generally used as a plasticizer and has a polyoxyalkylene group. Basic organic acid esters and the like can be preferably used.

Polyalkylene glycol-based plasticizers include polyethylene glycol, polypropylene glycol, poly(ethylene oxide/propylene oxide) block copolymers, poly(ethylene oxide/propylene oxide) random copolymers, polytetramethylene glycol, and the like.

A polyoxyalkylene ether-based plasticizer means an ether compound of a monohydric or polyhydric alcohol and polyoxyalkylene.
Examples of polyoxyalkylene ether plasticizers include polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene-2-ethylhexyl ether, polyoxyethylene nonyl ether, and polyoxyethylene decyl ether. , polyoxyethylene allyl ether, polyoxypropylene allyl ether, polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyethylene glycol diglyceryl ether, polypropylene glycol diglyceryl ether, polyoxyalkylene pentaerythritol ether and the like.

Monobasic organic acid esters include esters of glycols with monobasic organic acids. Glycols include polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the number of repeating alkylene units is 2 to 10, preferably 2 to 4.
Specific examples of glycols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and butylene glycol.
Examples of monobasic organic acids include organic acids having 3 to 10 carbon atoms, and specific examples include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, n-octylic acid, and 2-ethylhexylic acid. , n-nonylic acid and decylic acid.

Specific monobasic organic acid esters include triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, and triethylene glycol di-n-octanoate. , triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, Dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicapryate, triethylene glycol di-n-heptanoate, tetraethylene Glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate and the like.
The monobasic organic acid ester is not limited to the complete ester of each ester described above, and may be a partial ester. For example, it may be a partial ester of a glycol with a monobasic organic acid. Specific examples include triethylene glycol-mono-2-ethylhexanoate.

The content of the plasticizer having a polyoxyalkylene group in the polyvinyl acetal resin film is not particularly limited, but is, for example, 5 to 50 parts by mass with respect to the total 100 parts by mass of the polyvinyl acetal resin contained in the film. It is preferably 15 to 30 parts by mass.

The polyvinyl acetal-based resin film may contain a plasticizer other than the above-described plasticizer having a polyoxyalkylene group.
Examples of plasticizers other than plasticizers having a polyoxyalkylene group include organic phosphorus plasticizers, polybasic organic acid esters, alcohol plasticizers, esters of polyhydric alcohols, and the like.

Organic phosphorus plasticizers include, for example, tributoxyethyl phosphate, isodecylphenyl phosphate, triisopropyl phosphate, and the like.
Examples of polyvalent basic organic acid esters include dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, diisononyl adipate, heptyl nonyl adipate, dibutylcarbitol adipate, and mixed adipic acid. and esters. Mixed adipates include adipates prepared from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms.
Examples of alcohol-based plasticizers include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, and pentaerythritol.

Examples of esterified products of polyhydric alcohols include esterified products of polyhydric alcohols and monobasic organic acids, adducts of polyhydric alcohols and cyclic esters, and the like.
Monobasic organic acids include monobasic organic acids having 3 to 24 carbon atoms, preferably 6 to 18 carbon atoms. Specific examples of ester compounds of polyhydric alcohols and monobasic organic acids include mono- and diesters of glycerin and stearic acid, and mono- and diesters of glycerin and 2-ethylhexylic acid.
Examples of adducts of polyhydric alcohols and cyclic esters include caprolactone adducts of trimethylolpropane, and specifically polycaprolactone triols.

In the polyvinyl acetal-based resin film of the present invention, the polyoxyalkylene content (hereinafter simply referred to as polyoxyalkylene content) per 100 parts by mass of the unmodified polyvinyl acetal moiety is preferably 5 from the viewpoint of improving the flexibility of the film. to 50 parts by mass, more preferably 15 to 30 parts by mass.
When the component having a polyoxyalkylene group is a polyvinyl acetal resin having a polyoxyalkylene group, the content of polyoxyalkylene is the mass of the structural unit having a polyoxyalkylene group relative to 100 parts by mass of the unmodified polyvinyl acetal moiety. shall mean In addition, the polyoxyalkylene content, if the component having a polyoxyalkylene group is a component other than a polyvinyl acetal resin having a polyoxyalkylene group (for example, a plasticizer having a polyoxyalkylene group), the unmodified Suppose that it means the mass with respect to 100 mass parts of polyvinyl acetal parts.
Moreover, the unmodified polyvinyl acetal portion means the total amount of structural units having a hydroxyl group, structural units having an acetyl group, and structural units having an acetal group in the polyvinyl acetal-based resin.
For example, in the case of a film composed of an unmodified polyvinyl acetal resin and a plasticizer having a polyoxyalkylene group, the content of polyoxyalkylene relative to 100 parts by mass of the unmodified polyvinyl acetal moiety is 100 parts of the unmodified polyvinyl acetal resin. It means the amount of plasticizer having a polyoxyalkylene group relative to parts by mass.
Moreover, in the case of a film made of a polyvinyl acetal resin having a polyoxyalkylene group, it is as follows. That is, the content of polyoxyalkylene with respect to 100 parts by mass of the unmodified polyvinyl acetal moiety is the polyoxyalkylene group with respect to a total of 100 parts by mass of the structural unit having a hydroxyl group, the structural unit having an acetyl group, and the structural unit having an acetal group. means the mass of a structural unit having

(Unmodified polyvinyl acetal resin)
The polyvinyl acetal-based resin film of the present invention contains polyvinyl acetal-based resin as a main component. Here, the term "main component" means that it contains, for example, 50% by mass or more, preferably 80% by mass or more.
The polyvinyl acetal-based resin may be a polyvinyl acetal-based resin having the above-described polyoxyalkylene group, or may be an unmodified polyvinyl acetal-based resin. The unmodified polyvinyl acetal-based resin is a resin that does not contain structural units other than the structural unit having a hydroxyl group, the structural unit having an acetyl group, and the structural unit having an acetal group.
The unmodified polyvinyl acetal resin has the above polyoxyalkylene groups with respect to the amount of structural units having a hydroxyl group, the amount of structural units having an acetyl group, the amount of structural units having an acetal group, and the average degree of polymerization. Those within the range described for the polyvinyl acetal-based resin can be used without particular limitation.

(Additive)
The polyvinyl acetal-based resin film of the present invention may contain additives other than the plasticizer. Specific examples of the additive include ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, adhesion regulators, pigments, dyes, fluorescent whitening agents, crystal nucleating agents, and the like.

(Glass-transition temperature)
The glass transition temperature of the polyvinyl acetal resin film of the present invention is preferably 15 to 55°C, more preferably 15 to 50°C, still more preferably 20 to 45°C. When the glass transition temperature of the polyvinyl acetal-based resin film is equal to or lower than the above upper limit, the adhesion of the interlayer film for laminated glass containing the film to relatively low-polarity organic glass such as a polycarbonate plate can be improved. When the glass transition temperature of the polyvinyl acetal-based resin film is at least the above lower limit, the handleability can be improved without exhibiting adhesiveness or the like.
The glass transition temperature of the polyvinyl acetal-based resin film can be detected by performing viscoelasticity measurement using a dynamic viscoelasticity measuring device and reading the peak temperature of the loss tangent tan δ obtained from the viscoelasticity measurement result. Details of the measurement conditions are as described in Examples.

(thickness)
Although the thickness of the polyvinyl acetal-based resin film of the present invention is not particularly limited, it is, for example, 30 μm or more and 2000 μm or less, preferably 50 μm or more and 1000 μm or less.

(Method for producing polyvinyl acetal resin film)
Although the method for producing the polyvinyl acetal-based resin film of the present invention is not particularly limited, examples thereof include the following methods. A polyvinyl acetal-based resin composition containing a component having a polyoxyalkylene group is prepared. The polyvinyl acetal-based resin composition contains polyvinyl acetal-based resin as a main component (for example, 50% by mass or more based on solid content). In addition, the composition may contain a plasticizer, an additive, a solvent, and the like, if necessary.
Next, the polyvinyl acetal-based resin composition is preferably formed into a film by a known method. Specifically, the polyvinyl acetal-based resin composition may be applied to a support such as a release sheet, or poured into a mold, heated and dried as necessary, and molded into a film. Alternatively, it may be molded by extrusion molding, press molding, or the like.

<Interlayer film for laminated glass>
The interlayer film for laminated glass of the present invention (hereinafter sometimes simply referred to as an interlayer film) contains the polyvinyl acetal-based resin film described above. The intermediate film may have a single-layer structure consisting only of the above-described polyvinyl acetal-based resin film, or may have a multi-layer structure including the first layer consisting of the above-described film.
As shown in FIG. 1, the intermediate film of the present invention may be an intermediate film 30A having a single layer structure made of a polyvinyl acetal-based resin film 31. As shown in FIG. In this case, both surfaces of the film 31 constitute outermost surfaces that contact a pair of laminated glass members (first and second laminated glass members 41 and 42) that constitute the laminated glass. Since the film 31 has high flexibility and good adhesiveness to organic glass such as a polycarbonate plate, one or both of the first and second laminated glass members may be made of organic glass. However, one or both of the first and second laminated glass members may be inorganic glass.

Also, the intermediate film may have a multi-layer structure including at least the first layer made of the film 31 . The multilayered intermediate film may have at least one first layer.
In the case of a multilayer structure, the first layer may have two or more layers, and the first layer and a layer other than the above-described first layer (hereinafter, "second layer") ) may be used.
The second layer has a composition and physical properties different from those of the first layer, and is preferably a resin layer containing a thermoplastic resin. Examples of thermoplastic resins include polyvinyl acetal resins, acrylic resins, ethylene-vinyl acetate copolymer resins, ionomer resins, polyurethane resins, and thermoplastic elastomers. By using these resins, it becomes easier to secure the adhesiveness to the glass plate and the first layer. The thermoplastic resin may be used singly or in combination of two or more.
The second layer is preferably a layer made of a resin composition made of a thermoplastic resin, or a layer made of a resin composition containing a plasticizer and additives other than the plasticizer as appropriate in addition to the thermoplastic resin.

The thickness of the intermediate film of the present invention is, for example, 30 µm or more and 2000 µm or less, preferably 50 µm or more and 1000 µm or less. By setting the thickness of the intermediate film within such a range, the adhesiveness to the laminated glass member can be improved without increasing the thickness more than necessary.

<Laminated glass>
A laminated glass of the present invention comprises a first laminated glass member, a second laminated glass member, and an interlayer disposed between the first and second laminated glass members. In the laminated glass, the first and second laminated glass members are joined by an interlayer film, the first laminated glass member on one outermost surface of the interlayer film, and the second laminated glass member on the other outermost surface of the interlayer film. Glue to the outer surface. The structure of the intermediate film of the present invention is as described above.

Each of the first and second laminated glass members is a glass plate, preferably selected from inorganic glass and organic glass.

Examples of inorganic glass include, but are not limited to, float plate glass, tempered glass, colored glass, polished plate glass, figured glass, wired plate glass, lined plate glass, ultraviolet absorbing plate glass, infrared reflecting plate glass, infrared absorbing plate glass, Various glass plates, such as green glass, are mentioned. The inorganic glass may be subjected to surface treatment or the like.
Although the thickness of the inorganic glass is not particularly limited, it is preferably 0.1 mm or more, more preferably 1.0 mm or more, and preferably 5.0 mm or less, further preferably 3.2 mm or less.

The organic glass is not particularly limited, but may be a polycarbonate plate, a methacrylate plate such as a polymethylmethacrylate plate, an acrylonitrile-styrene copolymer plate, an acrylonitrile-butadiene-styrene copolymer plate, or a polyester plate such as a polyethylene terephthalate (PET) plate. , fluorine resin plate, polyvinyl chloride plate, chlorinated polyvinyl chloride plate, polypropylene plate, polystyrene plate, polysulfone plate, epoxy resin plate, phenol resin plate, unsaturated polyester resin plate, polyimide resin plate, etc. is mentioned. The organic glass may be appropriately subjected to surface treatment or the like.
Among the above, a polycarbonate plate is preferable from the viewpoint of excellent transparency, impact resistance, and combustion resistance, and a methacrylate plate such as a polymethyl methacrylate plate is preferable from the viewpoint of high transparency, excellent weather resistance, and mechanical strength. Among these, a polycarbonate plate is preferred.
Although the thickness of the organic glass is not particularly limited, it is preferably 0.1 mm or more, more preferably 0.3 mm or more, and preferably 5.0 mm or less, further preferably 3.0 mm or less.

The laminated glass of the present invention can be used in various fields. Specifically, vehicles such as automobiles and trains, ships, airplanes and other vehicles, buildings, condominiums, detached houses, halls, gymnasiums and other buildings, machine tools for cutting and polishing, shovels and cranes, etc. used for window glass of construction machinery, etc.

[Method for producing laminated glass]
Laminated glass can be produced by disposing a prefabricated interlayer between first and second laminated glass members and by thermocompression bonding or the like. In the laminated glass of the present invention, when the interlayer has a multilayer structure, the multilayer interlayer is prepared in advance, and the multilayer interlayer is disposed between the first and second laminated glass members. good too. In addition, a plurality of resin films for forming the first layer, the second layer, etc. are superimposed between the first and second laminated glass members, and the plurality of resin films are integrated to form a multilayer structure. It is preferable that the first and second laminated glass members are joined via the intermediate film, while the intermediate film is used as the first and second laminated glass members.

The method of thermocompression bonding is not particularly limited, but it is preferable to place an intermediate film or the like between a pair of glass members and apply pressure while heating them. The heating temperature is preferably 60° C. or higher and 150° C. or lower, more preferably 70° C. or higher and 140° C. or lower. Also, the pressure is preferably 0.4 MPa or more and 1.5 MPa or less, more preferably 0.5 MPa or more and 1.3 MPa or less. In addition, the pressure here is an absolute pressure. Moreover, the thermocompression bonding includes a method using an autoclave, a method using a hot press, and the like, but it is preferable to use an autoclave.

In the production of the above-mentioned laminated glass, after disposing an intermediate film or a plurality of resin films between the first and second laminated glass members, a pair of laminated films is optionally formed before thermocompression bonding. Air remaining between the glass members may be vented. The method of degassing is not particularly limited, but it is good to pass it through a press roll or put it in a rubber bag and suck it under reduced pressure.
Temporary bonding may be performed before thermocompression bonding. Temporary bonding may be carried out, for example, by arranging an intermediate film or a plurality of resin films between a pair of laminated glass members and pressing them with a relatively low pressure while heating as necessary. Temporary adhesion may be performed, for example, by a vacuum laminator. Temporary adhesion may be performed after deaeration, when deaeration is performed, and may be performed with deaeration.

The present invention will be described in more detail with reference to examples, but the present invention is not limited by these examples.
In addition, the measuring method of each physical-property value in this invention, and the evaluation method are as follows.

<Amount of increase in total concentration of aldehydes having 8 or less carbon atoms>
0.05 g of the polyvinyl acetal resin film prepared in each example and comparative example was introduced as a sample into a glass container with a volume of 10 cm ³ , sealed, and heated at 130° C. for 5 hours.
The sample after heating and the sample before heating were each measured by high performance liquid chromatography (HPLC) as shown below to determine the total concentration of aldehydes having 8 or less carbon atoms. The difference between the two was defined as the amount of increase in the total concentration of aldehydes having 8 or less carbon atoms (mass ppm).
(HPLC measurement conditions)
2 mL of 200 ppm DNPH (dinitrophenylhydrazine)-2M phosphoric acid solution and 2 mL of ethyl acetate were added to 2 mL of a 1% by mass sample aqueous solution, and the mixture was shaken at room temperature for 10 minutes, and then the ethyl acetate layer was separated and used as a sample for HPLC measurement. .
A high performance liquid chromatography (HPLC) apparatus (Prominence) manufactured by Shimadzu Corporation was used as a measuring instrument. Using a PDA as a detector, an Ascentis C18 column as a mobile phase, and a mixed solvent of water and acetonitrile as a mobile phase, the concentration of each aldehyde-dinitrophenylhydrazine adduct was measured under the conditions of a sample injection volume of 10 μL and a flow rate of 0.5 mL/min. Each aldehyde concentration in was calculated.

<Measurement of yellowness index (YI)>
The yellowness index (YI) was measured as follows for the samples obtained by heating the polyvinyl acetal-based resin films produced in Examples and Comparative Examples at 130° C. for 10 hours.
A transmission spectrum from 250 nm to 2500 nm was obtained in transmission mode using a spectrophotometer (U-4100, manufactured by Hitachi, Ltd.). The yellowness index (YI) was calculated according to JIS K 7373 from the obtained spectrum.

<Odor>
Samples obtained by heating the polyvinyl acetal-based resin films produced in Examples and Comparative Examples at 130° C. for 10 hours were evaluated for odor as follows.
According to the sensory evaluation, when a butyric acid-like odor was detected, the odor was "present", and when it was not detected, the odor was "absent".

<Weight average molecular weight>
The weight-average molecular weight of the polyvinyl acetal-based resin was obtained as follows using a sample obtained by heating the polyvinyl acetal-based resin film produced in each example and comparative example at 130° C. for 10 hours. Moreover, the weight average molecular weight of the polyvinyl acetal-based resin before heating was also measured.
A sample was dissolved in tetrahydrofuran to prepare a 0.01 wt % solution. The filtrate was collected with a syringe filter (Millex-LH, 0.45 μm), and the weight average molecular weight (Mw) in terms of polystyrene was measured using GPC (Waters #2690: column KF-806L) with tetrahydrofuran as the mobile phase. did.

<Amount of Structural Units Having Each Functional Group>
The polyvinyl acetal-based resin was dissolved in DMSO-d ⁶ and measured using 1H-NMR (nuclear magnetic resonance spectrum) to determine the amount of the constituent units of each unit.

<Glass transition temperature (Tg)>
The viscoelasticity of the polyvinyl acetal-based resin film produced in each example and comparative example was measured using a dynamic viscoelasticity measuring device (manufactured by IT Instrument Control Co., Ltd., trade name "DVA-200") under the following measurement conditions. was measured. The peak temperature of loss tangent tan δ obtained from the results of viscoelasticity measurement was read. The first peak temperature counted from the low temperature side in the temperature range of -50 to 150°C was taken as the glass transition temperature (Tg).
(Measurement condition)
Deformation mode: shear mode, measurement temperature: -50°C to 200°C, heating rate: 5°C/min, measurement frequency: 1 Hz, strain: 1%

<Polyvinyl acetal resin used>
· PVB-1 (unmodified polyvinyl butyral resin) · · "BH-3" manufactured by Sekisui Chemical Co., Ltd.
Amount of structural unit having a hydroxyl group 24% by mass
Amount of structural unit having an acetyl group 1% by mass
Amount of structural units having a butyral group 75% by mass
・PVB-2 (polyvinyl butyral resin having a polyoxyalkylene group)
Amount of structural unit having a hydroxyl group 16% by mass
Amount of structural unit having an acetyl group 2% by mass
Amount of structural units having a butyral group 64% by mass
Amount of structural units having a polyoxyalkylene group 18% by mass

(Manufacture of PVB-2)
In a flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 1000 parts by mass of vinyl acetate, 135 parts by mass of poly(oxyethylene/propylene) allyl ether having an average repeating unit of 60 and 20 parts by mass of methanol are added. After the inside of the system was replaced with nitrogen, the temperature was raised to 60°C. 1.0 parts by mass of 2,2-azobisisobutyronitrile was added to this system to initiate polymerization. Polymerization was stopped 5 hours after the start of polymerization. The mixture was heated while adding methanol to remove unreacted vinyl acetate to prepare a 40% by weight methanol solution of the copolymer. While stirring 100 parts by mass of the methanol solution of this copolymer at 40° C., 8 parts by mass of 3% NaOH methanol solution was added, mixed well, and then held at 40° C. for 2 hours. The solidified polymer was pulverized by a pulverizer, washed with methanol, and dried to obtain polymer powder.
1000 parts by mass of the obtained polymer powder was added to 7500 parts by mass of pure water and stirred at a temperature of 90° C. for 2 hours to dissolve. This solution is cooled to 10° C., 805 parts by mass of hydrochloric acid having a concentration of 35% by weight and 630 parts by mass of n-butyraldehyde are added, the liquid temperature is lowered to 20° C., and the acetalization reaction is carried out while maintaining the temperature. The product precipitated out. Thereafter, the liquid temperature was maintained at 40° C. for 3 hours to complete the reaction, and neutralization, washing with water and drying were carried out in the usual manner to obtain a white powder of PVB-2.

<Plasticizer used>
・PPG1000 Polypropylene glycol 1000 diol type manufactured by Wako Pure Chemical Industries, Ltd.

<Antioxidant used>
As antioxidants having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure, Irganox 1010 and Irganox 1076 below were used.
· Irganox 1010 Antioxidant with the structure of the following formula (I-1) manufactured by BASF Japan Co., Ltd.

· Irganox 1076 Antioxidant with the structure of the following formula (I-3) manufactured by BASF Japan Co., Ltd.

The following BHT was used as antioxidant without (3,5-di-tert-butyl-4-hydroxyphenyl)propionate.
・BHT dibutyl hydroxytoluene

(Example 1)
100 parts by mass of PVB-1, 20 parts by mass of a plasticizer (PPG1000), and an antioxidant (Irganox 1010) in an amount of 2000 ppm by mass relative to the total amount of the formed film, ethanol and toluene (1:1 mass ratio) to obtain a polyvinyl acetal-based resin composition. The polyvinyl acetal resin composition was applied onto a release film and dried at 80° C. for 120 minutes to obtain a polyvinyl acetal resin film with a thickness of 80 μm. The evaluation results are shown in Table 1.

(Example 2)
A polyvinyl acetal-based resin film was obtained in the same manner as in Example 1, except that the type of resin and the blending amount of antioxidant were changed as shown in Table 1, and the plasticizer was not used. The evaluation results are shown in Table 1.

(Example 3)
A polyvinyl acetal-based resin film was obtained in the same manner as in Example 2, except that the type of antioxidant was changed as shown in Table 1. The evaluation results are shown in Table 1.

(Comparative example 1)
A polyvinyl acetal resin film was obtained in the same manner as in Example 1, except that the amount of antioxidant was changed as shown in Table 1 and the plasticizer was not used. The evaluation results are shown in Table 1.

(Comparative example 2)
A polyvinyl acetal-based resin film was obtained in the same manner as in Comparative Example 1, except that the type and amount of the antioxidant was changed as shown in Table 1. The evaluation results are shown in Table 1.

(Comparative Example 3)
A polyvinyl acetal-based resin film was obtained in the same manner as in Example 1, except that the type and amount of the antioxidant was changed as shown in Table 1. The evaluation results are shown in Table 1.

(Comparative Example 4)
A polyvinyl acetal-based resin film was obtained in the same manner as in Example 2, except that the type and amount of the antioxidant was changed as shown in Table 1. The evaluation results are shown in Table 1.

The polyvinyl acetal-based resin film of each example, which satisfies the requirements of the present invention, had a low degree of yellowness after heating, no odor was confirmed, and no deterioration of the resin occurred. Further, the glass transition temperature was low, and the film was excellent in flexibility.
On the other hand, the polyvinyl acetal-based resin films of Comparative Examples 1 and 2 did not contain a component having a polyoxyalkylene group, and therefore had a high glass transition temperature and poor flexibility. Since the polyvinyl acetal-based resin films of Comparative Examples 3 and 4 did not use an antioxidant containing (3,5-di-tert-butyl-4-hydroxyphenyl)propionate, the total concentration of aldehyde increased by High result. Moreover, the polyvinyl acetal-based resin film of Comparative Example 4 had a high degree of yellowness, an odor was confirmed, and deterioration of the resin occurred.

30A Interlayer film for laminated glass 31 Film (first layer)
41 First laminated glass member 42 Second laminated glass member

Claims

It contains a component having a polyoxyalkylene group and contains 10 to 10000 ppm by mass of at least one antioxidant having (3,5-di-tert-butyl-4-hydroxyphenyl)propionate as a partial structure, and is sealed. A polyvinyl acetal-based resin film having a total concentration increase of 100 mass ppm or less of aldehydes having 8 or less carbon atoms after being heated at 130° C. for 5 hours in a container.
The polyvinyl acetal resin film according to claim 1, wherein the component having a polyoxyalkylene group is a polyvinyl acetal resin having a polyoxyalkylene group or a plasticizer having a polyoxyalkylene group.
The polyvinyl acetal resin film according to claim 1 or 2, wherein the polyoxyalkylene group is linked to the main chain of the polyvinyl acetal resin.
The polyvinyl acetal resin film according to any one of claims 1 to 3, wherein the repeating unit of the polyoxyalkylene group is at least one selected from the group consisting of an oxyethylene group and an oxypropylene group.
The polyvinyl acetal resin film according to any one of claims 1 to 4, wherein the antioxidant has a molecular weight of 1000 or more.
An interlayer film for laminated glass comprising the film according to any one of claims 1 to 5.
A laminated glass comprising the interlayer film for laminated glass according to claim 6 and first and second laminated glass members, wherein the laminated glass interlayer is disposed between the first and second laminated glass members. glass.