Interlayer for laminated glass

Abstract

To provide an intermediate film for laminated glass which contains a resin derived from non-petroleum, is excellent in glass adhesion, and has high stability to heat and impact.SOLUTION: An intermediate film for laminated glass contains a polymer compound with a sugar skeleton as a main chain, and the polymer compound contains a modified polymer compound esterified with a compound having at least one group selected from the group consisting of a phosphate group, a phosphite group, a sulfate group, and a sulfurous acid group and salts thereof.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an interlayer for laminated glass and laminated glass containing the interlayer for laminated glass. [Background technology]

[0002] Laminated glass, which combines inorganic glass with an interlayer for laminated glass, is known to be useful for purposes such as preventing the scattering of glass fragments when glass breaks or improving security, and laminated glass is also used in the exterior walls of buildings. Compositions containing polyvinyl acetal resin, such as polyvinyl butyral resin (hereinafter also referred to as "PVB resin"), are widely used as interlayers for laminated glass.

[0003] However, in recent years, with the growing awareness of a de-petroleum and carbon-neutral society, there is a demand for materials with low environmental impact to realize a sustainable society. For this reason, there is a need to replace the resins used in interlayers for laminated glass with non-petroleum-derived resins such as biomass-derived resins. Interlayers containing nitrocellulose and cellulose acetate are being considered as interlayers for laminated glass that include non-petroleum-derived resins. For example, Patent Document 1 discloses an interlayer for laminated glass having a functional layer on the surface of a resin interlayer containing PVB resin, and states that the resin interlayer may further contain nitrocellulose, and that nitrocellulose can be used as the matrix material constituting the functional layer. Patent Document 2 also discloses an interlayer for laminated glass in which an impermeable protective plastic thin film is laminated on an intermediate layer of PVB resin, and states that cellulose acetate can be used as the impermeable protective plastic thin film. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2021 / 005162 [Patent Document 2] Japanese Unexamined Patent Publication No. 14511 / 1983 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, our investigations have shown that when cellulose acetate is used as an interlayer or thin film, as in Patent Document 2, an adhesive layer or primer layer such as PVB resin is necessary between the glass and the cellulose acetate to ensure adhesion to the glass. We have also found that nitrocellulose may not be sufficiently stable against heat and impact.

[0006] Therefore, the object of the present invention is to provide an interlayer film for laminated glass that contains a non-petroleum-derived resin, has excellent glass adhesion properties, and has high stability against heat and impact. [Means for solving the problem]

[0007] The present inventors, after diligent research to solve the above problems, arrived at the present invention. That is, the present invention provides the following preferred embodiments.

[0008] [1] An interlayer for laminated glass comprising a polymer compound having a sugar backbone as its main chain, wherein the polymer compound is esterified with a compound having at least one group selected from the group consisting of a phosphate group, a phosphite group, a sulfate group, a sulfite group, and salts thereof. [2] The interfilm for laminated glass according to [1], wherein the content of the modified polymer compound is 50% by mass or more relative to the total amount of the polymer compound. [3] The interfilm for laminated glass according to [1] or [2], wherein the polymer compound is starch or cellulose. [4] An interlayer for laminated glass according to any one of [1] to [3], wherein at least a portion of the polymer compound is neutralized with metal ions. [5] An interfilm for laminated glass according to any one of [1] to [4], wherein the degree of esterification of the modified polymer compound is 0.1 or more. An interlayer film for laminated glass according to any one of [1] to [5], further containing a plasticizer. A laminated glass comprising two inorganic glasses and an interlayer film for laminated glass according to any one of [1] to [6] disposed between the two inorganic glasses.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide an interlayer film for laminated glass that contains a resin not derived from petroleum, has excellent glass adhesiveness, and has high stability against heat and impact.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is an example of the results of a stability test. [Figure 2] FIG. 2 is a schematic diagram of a laminated glass used for measuring glass adhesiveness. [Figure 3] FIG. 3 is a schematic diagram of a laminated glass used for measuring glass adhesiveness to which an iron plate is adhered.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention. Also, when a plurality of upper limit values and lower limit values are described for specific parameters, etc., any upper limit value and lower limit value can be combined to form a suitable numerical range.

[0012] 〔Interlayer Film for Laminated Glass〕 The interlayer film for laminated glass of the present invention (hereinafter also simply referred to as "interlayer film") contains a polymer compound having a sugar backbone as a main chain, and the polymer compound is a modified polymer compound esterified with a compound having at least one group selected from the group consisting of a phosphate group, a phosphite group, a sulfate group, a sulfite group, and salts thereof (hereinafter also referred to as "first modified polymer compound").

[0013] The inventors have found that in an interlayer film for laminated glass containing a polymer compound having a sugar backbone as the main chain as a resin derived from non-petroleum, when a first modified polymer compound is contained in the polymer compound, an interlayer film for laminated glass having excellent glass adhesiveness can be obtained. Although the reason why the glass adhesiveness of the interlayer film for laminated glass is improved when it contains the first modified polymer compound is not clear, it is considered that the interaction between the interlayer film for laminated glass and glass is strengthened because the first modified polymer compound contains a hydroxyl group of phosphoric ester, phosphite, sulfate ester and / or sulfite ester. Further, the inventors have found that the interlayer film for laminated glass of the present invention can improve the stability against heat and impact and reduce the risk of causing ignition and explosion by containing the first modified polymer compound. In the present specification, "stability" refers to a property related to causing thermal decomposition and generating rapid gas, combustion and explosion without the help of air, and a high or improved stability indicates that the risk of causing ignition and explosion is small or reduced even when subjected to heat or impact.

[0014] <Polymer compound having a sugar backbone as the main chain> The interlayer film for laminated glass of the present invention contains a polymer compound (hereinafter also simply referred to as "polymer compound") having a sugar backbone as the main chain, which is a resin derived from non-petroleum. The polymer compound having a sugar backbone as the main chain is not particularly limited, and examples thereof include polysaccharides such as starch, cellulose, chitin, chitosan, hemicellulose, pectin, pullulan, agar, alginic acid, carrageenan, dextrin; and polymers containing chain sugar alcohols such as threitol, erythritol, arabinitol as monomer units. These polymer compounds can be used alone or in combination of two or more. Among these polymer compounds, polysaccharides are preferable, polysaccharides containing glucose units are more preferable, and starch and cellulose are even more preferable from the viewpoints of the abundance as natural resources and easy availability, and the ease of improving the glass adhesiveness of the interlayer film.

[0015] In one embodiment of the present invention, the starch can be any of the following: common starches such as corn starch, waxy corn starch, wheat starch, potato starch, tapioca starch, sweet potato starch, bamboo shoot starch, and konjac starch; modified starches such as lightly oxidized starch and acid-treated soluble starch; and modified starches obtained by modifying these starches. These starches can be used alone or in combination of two or more. Examples of modified starches include esterified starch, etherified starch, and oxidized starch. For example, esterified starch refers to starch esterified with an esterifying reagent and has a modifying group derived from the esterifying reagent. Among these starches, corn starch and its modified starch are preferred from the viewpoint of being inexpensive, readily available, and producing a reaction solution with low viscosity.

[0016] In one embodiment of the present invention, examples of cellulose include natural cellulose such as wood pulp obtained from hardwoods or softwoods, and refined pulp from non-wood species (i.e., non-wood pulp), regenerated cellulose, and modified cellulose obtained by modifying these celluloses. These celluloses can be used individually or in combination of two or more. Examples of modified cellulose include esterified cellulose, etherified cellulose, and oxidized cellulose. For example, esterified cellulose refers to cellulose esterified with an esterifying reagent and has modifying groups derived from the esterifying reagent. Examples of non-wood pulp include cotton-derived pulp (e.g., refined linters) including cotton linter pulp, hemp-derived pulp, bagasse-derived pulp, kenaf-derived pulp, bamboo-derived pulp, straw-derived pulp, etc. Cotton-derived pulp, hemp-derived pulp, bagasse-derived pulp, kenaf-derived pulp, bamboo-derived pulp, and straw-derived pulp refer to refined pulp obtained from raw materials such as cotton lint, cotton linters, hemp-based abaca (often from Ecuador or the Philippines), zaisal, bagasse, kenaf, bamboo, and straw, through purification processes such as deligninization by pulping and bleaching. As natural cellulose, cellulose fiber aggregates originating from animals (e.g., sea squirts), algae, microorganisms (e.g., acetic acid bacteria), and microbial products can be used. As regenerated cellulose, cut yarns of regenerated cellulose fibers (viscose, cupro, Tencel, etc.), cut yarns of cellulose derivative fibers, and ultrafine yarns of regenerated cellulose or cellulose derivatives obtained by electrospinning can be used. For detailed information on these raw materials, cellulose, see, for example, Marusawa and Uda, "Plastic Materials Lecture (17) Cellulose Resins," Nikkan Kogyo Shimbun (published in 1970), and the Japan Institute of Invention and Innovation, Public Technical Report No. 2001-1745 (pp. 7-8). Among these celluloses, wood pulp and its modified cellulose are preferred from the viewpoint of availability.

[0017] The polymer compound in the interlayer of the present invention includes a first modified polymer compound esterified (or modified) with a compound having at least one group selected from the group consisting of phosphate groups, phosphite groups, sulfate groups, sulfite groups, and salts thereof. From the viewpoint of further improving the glass adhesion and stability of the interlayer, the first modified polymer compound is preferably a modified polymer compound esterified with a compound having at least one group selected from the group consisting of phosphate groups, phosphite groups, and salts thereof. In this specification, unless otherwise specified, the terms "polymer compound with a sugar backbone as the main chain" and "polymer compound" mean modified polymer compound and / or unmodified polymer compound.

[0018] Compounds having at least one group selected from phosphate groups, phosphite groups, sulfate groups, sulfite groups, and salts thereof include, for example, phosphoric acid, dehydrated condensates of phosphoric acid, pyrophosphate, phosphonic acid, phosphinic acid, metaphosphate, polyphosphate, sulfuric acid, sulfite, sulfonic acid, and salts thereof. These compounds may contain water in the form of hydrated water, or they may be anhydrous and contain no water. These can be used alone or in combination of two or more. Salts of these compounds include lithium salts, sodium salts, potassium salts, ammonium salts, organic ammonium salts, and organic phosphonium salts, and these salts can be used alone or in combination of two or more. Among these, phosphoric acid, pyrophosphate, sodium salts of phosphoric acid, or potassium salts of phosphoric acid, ammonium salts of phosphoric acid, sodium salts of pyrophosphate, potassium salts of pyrophosphate, ammonium salts of pyrophosphate, and sulfuric acid are preferred from the viewpoint of easily improving the glass adhesion and stability of the interlayer film, as well as being low cost and easily applicable industrially.

[0019] The first modified polymer compound has a modifying group (or substituent) derived from a compound having at least one group selected from a phosphate group, a phosphite group, a sulfate group, a sulfite group, and salts thereof. In one embodiment of the present invention, the first modified polymer compound preferably has at least one modifying group selected from the group consisting of a phosphate group, a phosphite group, a sulfate group, and a sulfite group, more preferably at least one modifying group selected from the group consisting of a phosphate group and a phosphite group, and even more preferably a phosphate group, from the viewpoint of easily improving the glass adhesion and stability of the interlayer film. These modifying groups may be neutralized with metal ions. Examples of the metal ions include alkali metal ions such as lithium, sodium, and potassium; and alkaline earth metal ions such as magnesium and calcium. These metal ions can be used alone or in combination of two or more.

[0020] In one embodiment of the present invention, it is preferable that at least a portion of the first modified polymer compound is neutralized with a metal ion, that is, at least one of the modifying groups of the first modified polymer compound is neutralized with a metal ion. When a portion or all of the first modified polymer compound is neutralized with a metal ion, the thermal stability of the interlayer film is easily improved, and the degradation of the polymer compound is easily suppressed, thus making it easier to suppress blackening due to degradation of the polymer compound. Examples of metal ions include those described above, and from the viewpoint of easily improving the thermal stability of the interlayer film and easily suppressing blackening, alkali metal ions are preferred, more preferably lithium ions and sodium ions. The method of neutralization with metal ions is not particularly limited, and for example, it may be carried out by immersing the first modified polymer compound in an alkali metal solution for alkali treatment, and then washing it.

[0021] In one embodiment of the present invention, the degree of neutralization of the modifying group of the first modified polymer compound is not particularly limited and may be, for example, 0 to 100%. However, from the viewpoint of easily improving thermal stability and easily suppressing blackening, it is preferably 10% or more, more preferably 15% or more, even more preferably 20% or more, even more preferably 30% or more, and particularly preferably 35% or more. Furthermore, from the viewpoint of reducing water absorption and easily preventing yellowing of the interlayer film, especially when heated for a long time, the degree of neutralization is preferably 90% or less, more preferably 85% or less, even more preferably 80% or less, even more preferably 75% or less, and particularly preferably 70% or less. The degree of neutralization can be measured by ICP emission spectrometry.

[0022] In one embodiment of the present invention, the degree of esterification of the first modified polymer compound, that is, the degree of esterification of the modified group derived from at least one group selected from phosphate groups, phosphite groups, sulfate groups, sulfite groups and their salts, and the group neutralized with these metal ions (hereinafter also referred to as the "first degree of esterification"), is preferably 0.1 or higher, more preferably 0.3 or higher, even more preferably 0.5 or higher, even more preferably 0.8 or higher, particularly preferably 1.0 or higher, particularly more preferably 1.2 or higher, and most preferably 1.5 or higher. When the first degree of esterification is above the lower limit, the glass adhesion and stability of the interlayer film are easily improved, and the processability is also easily improved, making it easier to process the raw material into an interlayer film even when a fibrous raw material is used. The upper limit of the first degree of esterification is not particularly limited, but from the viewpoint of easily suppressing yellowing of the interlayer film, it is preferably 3.0 or lower, more preferably 2.8 or lower, and even more preferably 2.6 or lower.

[0023] The degree of esterification refers to the proportion to which the hydroxyl groups of the monomer units constituting a modified polymer compound are esterified by an esterifying agent such as an inorganic acid or its salt. For example, if the polymer compound is cellulose, the glucose units constituting cellulose have free hydroxyl groups at positions 2, 3, and 6, so the upper limit of the degree of esterification of modified cellulose is 3.0. Therefore, the degree of esterification of unmodified cellulose is 0, and the degree of esterification of completely (100%) esterified modified cellulose is 3.0.

[0024] The degree of ester substitution can be measured using known methods, for example, by ICP emission spectroscopy. The first degree of ester substitution can be determined by measuring the content of the core element of the substituent (or modifying group), for example, phosphorus in the case of a phosphate ester, or sulfur in the case of a sulfate ester, using ICP emission spectroscopy. For example, it can be determined by the method described in the examples, where the modified polymer compound is subjected to microwave decomposition in nitric acid, and then calculated according to the following formula (1) described in Carbohydrate Polymers 229 (2020) 115294.

[0025]

number

[0026] In one embodiment of the present invention, the viscosity-average molecular weight of the first modified polymer compound is preferably 30,000 or more, more preferably 50,000 or more, even more preferably 100,000 or more, and particularly preferably 200,000 or more, from the viewpoint of easily improving penetration resistance. Furthermore, the viscosity-average molecular weight is preferably 500,000 or less, more preferably 400,000 or less, even more preferably 350,000 or less, and particularly preferably 300,000 or less, from the viewpoint of good solubility, easily reducing the viscosity of the dope used when manufacturing the interlayer film, and facilitating the manufacture of the interlayer film. The viscosity-average molecular weight can be determined, for example, by measuring the intrinsic viscosity number [η] of a dilute copper ethylenediamine (CED) solution in accordance with JIS P8215:1998 and applying it to the following formula. [η] = 190 × [DP] Viscosity average molecular weight=162×[DP]+18

[0027] In one embodiment of the present invention, the phosphorus concentration in the first modified polymer compound is preferably 1.8% by mass or more, more preferably 3.0% by mass or more, even more preferably 5.0% by mass or more, even more preferably 7.7% by mass or more, particularly preferably 13% by mass or more, and particularly more preferably 16% by mass or more. When the phosphorus concentration is above the lower limit of the above, it is easier to improve the glass adhesion and stability of the interlayer film, and it is easier to suppress the formation of hydrogen bonds in the polymer compound, and even when a fibrous raw material is used, the raw material is easier to loosen and easier to process into an interlayer film shape. Furthermore, from the viewpoint of easily suppressing yellowing of the interlayer film, the phosphorus concentration in the first modified polymer compound is preferably 23% by mass or less, more preferably 21% by mass or less.

[0028] In one embodiment of the present invention, the sulfur concentration in the first polymer compound is preferably 1.8% by mass or more, more preferably 3.0% by mass or more, even more preferably 5.0% by mass or more, even more preferably 7.7% by mass or more, particularly preferably 13% by mass or more, and particularly more preferably 16% by mass or more. When the sulfur concentration is above the lower limit of the above, it is easier to improve the glass adhesion and stability of the interlayer film. Furthermore, the sulfur concentration in the first modified polymer compound is preferably 21% by mass or less, from the viewpoint of easily suppressing yellowing of the interlayer film.

[0029] In one embodiment of the present invention, the metal ion concentration in the first modified polymer compound is preferably 0.8% by mass or more, more preferably 2.2% by mass or more, even more preferably 3.3% by mass or more, even more preferably 5.4% by mass or more, particularly preferably 6.9% by mass or more, particularly more preferably 8.0% by mass or more, and most still more preferably 10% by mass or more. Furthermore, from the viewpoint of reducing the specific gravity of the polymer compound and making it easier to obtain a lightweight sheet, the metal ion concentration is preferably 26% by mass or less, more preferably 25% by mass or less. When the metal ion concentration in the first modified polymer compound is within the above range, it is easier to improve the glass adhesion and stability of the interlayer, and it is easier to suppress the degradation of the polymer compound and suppress blackening and yellowing of the interlayer.

[0030] In one embodiment of the present invention, the first modified polymer compound preferably has a phosphorus concentration and / or sulfur concentration of 1.8% by mass or more, and a metal ion concentration of 0.8% by mass or more, more preferably 2.2% by mass or more, even more preferably 3.3% by mass or more, even more preferably 5.4% by mass or more, particularly preferably 6.9% by mass or more, particularly more preferably 8.0% by mass or more, and most even more preferably 10% by mass or more.

[0031] The phosphorus, sulfur, and metal ion concentrations in the polymer compound can be determined by ICP emission spectroscopy, for example, by the method described in the examples.

[0032] In one embodiment of the present invention, the first modified polymer compound preferably includes modified starch and / or modified cellulose esterified with a compound having at least one group selected from a phosphate group, a phosphite group, a sulfate group, a sulfite group, and salts thereof, from the viewpoint of easily improving the glass adhesion and stability of the interlayer film. More preferably, it is starch phosphate, cellulose phosphate, starch sulfate and / or cellulose sulfate, and even more preferably starch phosphate and / or cellulose phosphate.

[0033] In one embodiment of the present invention, the content of the first modified polymer compound is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, particularly more preferably 95% by mass or more, and also preferably 100% by mass or less, relative to the total amount of polymer compounds, from the viewpoint of easily improving the glass adhesion and stability of the interlayer film.

[0034] In one embodiment of the present invention, the content of the first modified polymer compound in the interlayer is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more, relative to the total amount of the interlayer, from the viewpoint of easily improving the glass adhesion and stability of the interlayer. Furthermore, there is no particular upper limit to the content of the first modified polymer compound in the interlayer, and it may be 100% by mass or less.

[0035] The method for producing the first modified polymer compound is not particularly limited and can be produced by known methods. For example, it can be produced by reacting a polymer compound having a sugar backbone as its main chain with a compound having at least one group selected from the group consisting of phosphate groups, phosphite groups, sulfate groups, sulfite groups, and salts thereof as an esterifying agent. The reaction between the polymer compound and the esterifying agent may be carried out in a heterogeneous system by dispersing the polymer compound together with the esterifying agent in a solvent, or in a homogeneous system by dissolving the polymer compound in the solvent. Furthermore, the reaction may be carried out in the absence of a solvent, for example, by heating and kneading the polymer compound and esterifying agent in a kneader or the like, or by reacting in an infrared indirect heating device or a microwave heating device. When reacting in a homogeneous system, the polymer compound can be dissolved in the solvent by performing the pretreatment described later on the polymer compound.

[0036] The solvent that can be used in the reaction between the polymer compound and the esterification reagent is not particularly limited and may be water and / or an organic solvent. From the viewpoint of easily dissolving the compound having at least one group selected from the group consisting of phosphate groups, phosphite groups, sulfate groups, sulfite groups and salts thereof, and being easy to handle, it is preferable to use water. However, from the viewpoint of easily increasing the degree of esterification, it is preferable to use an organic solvent that can swell or dissolve the polymer compound. In addition, if the reaction is carried out at a high temperature in order to accelerate the reaction, urea can also be used as a solvent.

[0037] The organic solvent is not particularly limited, and alcoholic solvents, ketone solvents, ester solvents, alkylamide solvents, pyrrolidone solvents, halogen-containing solvents, or mixtures thereof can be used. Examples of alcoholic solvents include methanol, ethanol, isopropyl alcohol, and hexanol. Examples of ketone solvents include acetone and methyl ethyl ketone. Examples of ester solvents include ethyl acetate, methyl formate, trimethyl phosphate, and triethyl phosphate. Examples of alkylamide solvents include N,N-dimethylformamide and N,N-dimethylacetamide. Examples of pyrrolidone solvents include 2-pyrrolidone and 3-pyrrolidone. Examples of halogen-containing solvents include dichloromethane. From the viewpoint of easily preventing side reactions, N,N-dimethylformamide, N,N-dimethylacetamide, dichloromethane, trimethyl phosphate, and triethyl phosphate are preferred, and from the viewpoint of the solubility of inorganic acid esters, N,N-dimethylformamide, N,N-dimethylacetamide, trimethyl phosphate, and triethyl phosphate are more preferred.

[0038] From the viewpoint of increasing reactivity, it is preferable to swell the polymer compound in an organic solvent before reacting it with the esterification reagent. Preferred solvents for swelling are N,N-dimethylformamide, N,N-dimethylacetamide, dichloromethane, trimethyl phosphate, and triethyl phosphate, with dimethylformamide, dimethylacetamide, trimethyl phosphate, and triethyl phosphate being more preferred.

[0039] In addition to swelling the polymer compound in an organic solvent, pretreatment may be performed to dissolve the polymer compound in the solvent. The pretreatment is not particularly limited, and known methods can be used. For example, the following methods (i) and (ii) can be cited. Method (i): An activation method generally called alcellation or mercellation, which involves mixing a polymer compound, such as cellulose, with a large amount of water and a large excess of alkali metal hydroxide to obtain an alkaline polymer compound (e.g., alkali cellulose). Method (ii): A method for dissolving polymer compounds, such as cellulose, using solvents such as dimethyl sulfoxide containing tetrabutylammonium fluoride, dimethyl sulfoxide containing paraformaldehyde, and dimethylacetamide containing lithium chloride, as described in "Encyclopedia of Cellulose, edited by the Cellulose Society, published by Asakura Shoten Co., Ltd.", Macromol. Chem. Phys. 201, 627-631 (2000), etc. Among these methods, the reaction using a dimethylacetamide solvent containing lithium chloride is preferred because it is a mild reaction that allows for quick pretreatment.

[0040] In the above reaction, in addition to the polymer compound, esterification reagent, and solvent, a catalyst may also be used. Examples of catalysts include amines such as methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, and hexamethylenediamine. Among these, triethylamine is preferred. Furthermore, when using a compound having at least one group selected from the group consisting of phosphate groups such as phosphoric acid, phosphite groups, and salts thereof as an esterification reagent, it is preferable to use phosphorus pentoxide in combination, from the viewpoint of easily increasing the degree of esterification. When using a compound having at least one group selected from the group consisting of sulfate groups (such as sulfuric acid), sulfite groups, and salts thereof as an esterification reagent, it is preferable to use an acid anhydride in combination.

[0041] In one embodiment of the present invention, the polymer compound may include, in addition to the first modified polymer compound, a second modified polymer compound esterified with an organic acid and its salt, to the extent that the effects of the present invention are not impaired. The second modified polymer compound is a compound having a modified group such as an organic acid ester group introduced by an organic acid and its salt. Examples of the modified group are alkyl carbonyl ester group, alkenyl carbonyl ester group, aromatic carbonyl ester group, aromatic alkyl carbonyl ester group, etc., and each may have further substituted groups. Preferred examples of these include acetyl group, propionyl group, butyryl group, heptanol group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, isobutanoyl group, tert-butanoyl group, cyclohexanecarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group, etc. When the second modified polymer compound has these substituents, its affinity for organic solvents is easily increased, and corrosion of equipment by inorganic acids is easily reduced. Among these, the presence of an acetyl group, a propionyl group, and a butyryl group is more preferable from the standpoint of manufacturing costs, and the presence of an acetyl group is particularly preferable.

[0042] In one embodiment of the present invention, the amount of modifying groups such as organic acid ester groups in the second modified polymer compound is preferably small from the viewpoint of easily improving the glass adhesion of the interlayer. In one embodiment of the present invention, the degree of ester substitution of organic acid ester groups in the second modified polymer compound (hereinafter also referred to as the "second degree of ester substitution") is preferably 2.0 or less, more preferably 1.8 or less, even more preferably 1.6 or less, even more preferably 1.5 or less, particularly preferably 1.3 or less, particularly more preferably 1.0 or less, especially preferably 0.6 or less, and especially more preferably 0.5 or less, from the viewpoint of easily improving the glass adhesion of the interlayer. Furthermore, the lower limit of the degree of organic acid ester substitution is not particularly limited and may be 0 or more. The second degree of ester substitution can be calculated by chemical analysis by NMR, for example, by calculating the area ratio of peaks originating from the modifying groups in NMR.

[0043] In one embodiment of the present invention, the content of the second modified polymer compound is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 20% by mass or less, particularly preferably 10% by mass or less, particularly more preferably 5% by mass or less, and may also be 0% by mass or more, from the viewpoint of easily improving the glass adhesion and stability of the interlayer film, relative to the total amount of polymer compounds.

[0044] The method for producing the second modified polymer compound is not particularly limited. For example, it may be produced by using the above-mentioned organic acid and its salt as an esterification reagent in the method for producing the first modified polymer compound.

[0045] In one embodiment of the present invention, the polymer compound may further contain an unmodified polymer compound. In one embodiment of the present invention, the content of the unmodified polymer compound is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, and may be 0% by mass or more, based on the total amount of the polymer compound.

[0046] In one embodiment of the present invention, the viscosity-average molecular weight of the second modified polymer compound and the polymer compound other than the first polymer compound, such as the unmodified polymer compound, is not particularly limited and can be selected from the same range as the viscosity-average molecular weight of the first modified polymer compound.

[0047] In one embodiment of the present invention, it is preferable that the polymer compound does not contain polymer compounds that fall under Class 5 hazardous materials under the Japanese Fire Service Act, from the viewpoint of easily improving the stability of the polymer compound and the interlayer. Examples of polymer compounds that fall under Class 5 hazardous materials under the Fire Service Act include organic peroxides, nitrate esters, nitro compounds, nitroso compounds, azo compounds, diazo compounds, hydrazine derivatives, hydroxylamines, hydroxylamine salts, metal azides, guanidine nitrate, 1-allyloxy-2,3-epoxypropane, 4-methylideneoxetan-2-one, and polymer compounds that contain any of these or have substituents derived therefrom. In one embodiment of the present invention, it is preferable that the polymer compound does not contain polymer compounds having nitrate ester groups or nitro groups, such as nitrocellulose, from the viewpoint of easily improving the stability of the polymer compound and the interlayer.

[0048] In one embodiment of the present invention, from the viewpoint of easily suppressing or preventing the generation of harmful halogen gases in the event of a fire, it is preferable that the polymer compound does not contain inorganic acids containing halogen atoms such as chlorosulfonic acid, hydrofluoric acid, hydrochloric acid, chloric acid, perchloric acid, iodic acid, hydroiodic acid, hydrobromic acid, hexafluorophosphate, and modified polymer compounds modified using halides (salts) of these inorganic acids as esterifying reagents.

[0049] In one embodiment of the present invention, the total calorific value of the polymer compound, as measured in accordance with ISO 1716, is preferably 20 MJ / kg or less, more preferably 17 MJ / kg or less, even more preferably 12 MJ / kg or less, even more preferably 10 MJ / kg or less, particularly preferably 8 MJ / kg or less, particularly more preferably 6 MJ / kg or less, particularly more preferably 4 MJ / kg or less, particularly preferably 3 MJ / kg or less, particularly more preferably 2 MJ / kg or less, and particularly still preferably 1 MJ / kg or less, from the viewpoint of easily improving the flame resistance of the interlayer in applications where excellent fire spread prevention performance is required. The lower limit of the total calorific value is not particularly limited and may be 0 MJ / kg or less. The lower the total calorific value of the polymer compound with a sugar backbone as its main chain, the easier it is to design the interlayer, such as the types and content of other components other than the polymer compound that may be included in the interlayer. The total calorific value of the polymer compound with a sugar backbone as its main chain can be adjusted, for example, by the content of the modified polymer compound in the polymer compound, and can be adjusted to below the above upper limit by increasing the content of the first modified polymer compound or decreasing the content of the second modified polymer compound. The total heat generation can be measured in accordance with ISO 1716, for example, by the method described in the examples.

[0050] <Plasticizer> In one embodiment of the present invention, the interlayer for laminated glass may further contain a plasticizer, to the extent that it does not impair the effects of the present invention, in order to reduce the viscosity of the polymer compound and improve the film-forming properties of the interlayer.

[0051] Conventional plasticizers can be used, and examples include phthalates, isophthalates, fatty acid esters (e.g., oleates, adipicates, fumarates, sebacates, maleates, succinates, etc.), polyhydric alcohol ethers or esters (e.g., glycerol esters, ethylene glycol esters or ethers, 1,2-propylene glycol esters or ethers, etc.), benzoates, diethylene glycol dibenzoate, azelaates, arylene-bis(diaryl phosphate), citrate esters, phosphate esters, polyesters, trimellitic acid esters (e.g., tributyl trimellitic acid, trioctyl trimellitic acid), inorganic acids, sugars (e.g., monosaccharides, oligosaccharides, chain-like sugar alcohols), etc. These plasticizers can be used individually or in combination of two or more.

[0052] The following are some examples of plasticizers mentioned above, but they are not limited to these examples. Triacetin, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate, biphenyl diphenyl phosphate, triphenyl phosphate, tri(2-ethylhexyl) phosphate, tri(butoxyethyl) phosphate, tri(2-ethylhexyl) phosphate, triethyl citrate, acetyl trimethyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, o-acetyl tributyl citrate, dibutyl phthalate, diaryl phthalate, diethyl phthalate, dimethyl phthalate, di-(2-methoxyethyl) phthalate, dioctyl phthalate, dioctyl adipate, dibutyl tartrate, o-benzoyl ethyl benzoate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, N-ethyltoluenesulfonamide, p-toluenesulfonic acid o-cresyl, ethylene glycol, diethylene glycol, 1,2-propionic acid Phenylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,5-pentylene glycol, triethylene glycol, and tetraethylene glycol, aromatic diols, substituted aromatic diols, aromatic ethers, trippropionine, tribenzoin, polycaprolactone, glycerin, glycerin esters, diacetin, propylene glycol dibenzoate, glyceryl tribenzoate, diethylene glycol dibenzoate, triethylene glycol dibenzoate, dipropylene glycol dibenzoate, and ethylene glycol dibenzoate, glyceryl benzoate acetate, stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, hydroquinone, catechol, resorcinol, ethylene glycol, neopentyl glycol, 1,4-Cyclohexanedimethanol, diethylene glycol, polyethylene glycol, polyethylene glycol ester, polyethylene glycol diester, di-2-ethylhexyl polyethylene glycol ester, bis(2-ethylhexanoic acid)triethylene glycol, glycerin ester, diethylene glycol, polypropylene glycol, polyglycol diglycidyl ether, dimethyl sulfoxide, N-methylpyrrolidinone, C1-C20 dicarboxylic acid esters, dimethyl adipate, dihexyl adipate, di(2-ethylhexyl) adipate, 3-methyl-1 adipate,5-Pentanediol, Dibutyl Maleate, Dioctyl Maleate, Resorcinol Acetate, Catechol, Catechol Esters, Phenols, Epoxylated Soybean Oil, Castor Oil, Linseed Oil, Epoxylated Linseed Oil, Other Vegetable Oils, Other Seed Oils, Polyethylene Glycol Bifunctional Glycidyl Ether, γ-Valerolactone, Alkyl Phosphates, Aryl Phosphates, Phospholipids, Eugenol, Cinnamyl Alcohol, Camphor, Methoxyhydroxyacetophenone, Vanillin, Ethyl Vanillin, 2-Phenoxyethanol, Glycol Ethers, Glycol Esters, Glycol Ester Ethers, Polyglycol Ethers, Polyglycol Esters, Ethylene Glycol Ethers, Propylene Glycol Ethers, Ethylene Glycol Esters, Propylene Glycol Esters, Polypropylene Glycol Esters, Acetylsalicylic Acid, Acetaminophen Ethanol, naproxen, imidazole, triethanolamine, benzoic acid, benzyl benzoate, salicylic acid, 4-hydroxybenzoic acid, 4-hydroxybenzoate propyl, 4-hydroxybenzoate methyl, 4-hydroxybenzoate ethyl, 4-hydroxybenzoate benzyl, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, butylated hydroxytoluene, butylated hydroxyanisole, e Tylenediamine, piperidine, piperazine, hexamethylenediamine, triazine, triazole, pyrrole, glucose, galactooligosaccharides, isomaltoligosaccharides, xylooligosaccharides, soybean oligosaccharides, nigerooligosaccharides, lactulose oligosaccharides, fructooligosaccharides, alginic acid, trehalose, guar gum, treitol, erythritol, arabinitol, xylitol, iditol, galactitol, mannitol, sorbitol, and mixtures thereof.

[0053] Among these plasticizers, sugars, polyhydric alcohol ethers or esters, and phosphate esters are preferred from the viewpoint of being less prone to bleed-out, more preferably monosaccharides, disaccharides, chain alcohols with 6 or fewer carbon atoms, trialkyl phosphates, and even more preferably chain alcohols with 5 to 6 carbon atoms, trimethyl phosphate, and ethyl phosphate. When the plasticizer contains a phosphate ester, it is easier to suppress the decomposition of the modifying group in the modified polymer compound.

[0054] In one embodiment of the present invention, the carbon content per molecule of the plasticizer (in the unit chemical structure) is not particularly limited and may be 0 to 100%, but from the viewpoint of easily improving the flame resistance of the interlayer film and easily improving compatibility with the first modified polymer compound such as phosphoric acid-modified and / or sulfuric acid-modified cellulose, a lower value is preferable, for example, preferably 60% or less, more preferably 50% or less, even more preferably 45% or less, even more preferably 40% or less, and particularly preferably 30% or less. The carbon content per molecule of the plasticizer (in the unit chemical structure) can be determined by the carbon content in the chemical formula if the plasticizer is a low molecular weight compound with a molecular weight of less than 10,000 g / mol, or by dividing the weight of carbon atoms in the unit chemical structure by the average molar molecular weight if the plasticizer is a polymer with a weight-average molecular weight of 10,000 or more. The method for determining the average molar molecular weight of the polymer is not particularly limited, and weight-average molecular weight, number-average molecular weight, viscosity-average molecular weight, etc. can be used, but in the present invention, weight-average molecular weight is used.

[0055] In one embodiment of the present invention, the molecular weight or weight-average molecular weight of the plasticizer is preferably less than 30,000, more preferably 10,000 or less, even more preferably 1,000 or less, even more preferably 500 or less, and particularly preferably 300 or less.

[0056] In one embodiment of the present invention, the plasticizer content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on the total mass of the interlayer film, from the viewpoint of easily suppressing bleed-out from the resin. Furthermore, the plasticizer content is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 5% by mass or more, and particularly preferably 10% by mass or more, based on the total mass of the interlayer film, from the viewpoint of easily making the interlayer film flexible.

[0057] <Materials that reduce heat generation> In one embodiment of the present invention, the interlayer for laminated glass of the present invention may further contain a heat-reducing material as needed, for example, in applications where excellent fire spread prevention performance is required, from the viewpoint of easily reducing the total heat generated by the interlayer and easily improving flame resistance.

[0058] In this specification, a calorific value reducing material means a material that has a calorific value reducing effect when mixed with a polymer compound, that is, a material whose total calorific value measured in accordance with ISO 1716 is 10 MJ / kg or less on its own. Examples of calorific value reducing materials include inorganic acids and their salts or halides, metal hydroxides and their salts, metal salts, low molecular weight carboxylic acids and their salts or halides, phytic acid, urea, etc. Examples of inorganic acids and their salts and halides include phosphoric acid, pyrophosphate, phosphonic acid, phosphinic acid, metaphosphate, polyphosphate, sulfuric acid, sulfurous acid, chlorosulfonic acid, boric acid, hydrofluoric acid, hydrochloric acid, chloric acid, perchloric acid, iodic acid, hydroiodic acid, hydrobromic acid, hydrocyanic acid, hexafluorophosphate, silicic acid, salts thereof, and halides thereof. Examples of metal hydroxides and metal salts include metal hydroxides and halides such as lithium, sodium, calcium, potassium, magnesium, and aluminum. Examples of low molecular weight carboxylic acids and their salts, and their halides include oxalic acid, tartaric acid, malonic acid, malic acid, citric acid, fumaric acid, maleic acid, aspartic acid, their salts, and their halides. Among these, inorganic acids containing phosphorus or sulfur, such as phosphoric acid, pyrophosphate, phosphonic acid, phosphinic acid, metaphosphate, polyphosphate, sulfuric acid, and sulfite, and their salts are preferred from the viewpoint of reducing the amount of heat generated, and inorganic acids containing phosphorus and their salts are more preferred.

[0059] In one embodiment of the present invention, the content of the heat-reducing material can be appropriately selected according to the flame resistance required for the interlayer. For example, the content of the heat-reducing material can be reduced when the polymer compound contains only the first modified polymer compound, rather than when the polymer compound contains a second modified polymer compound or an unmodified polymer compound in addition to the first modified polymer compound. In one embodiment of the present invention, the content of the heat-reducing material is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 20% by mass or less, particularly preferably 10% by mass or less, particularly more preferably 5% by mass or less, and particularly still preferably 1% by mass or less, relative to the total mass of the interlayer. The lower limit of the content is not particularly limited and may be 0% by mass or more. In one embodiment of the present invention, it is preferable that the interlayer does not contain the heat-reducing material, from the viewpoint of easily suppressing the separation of the polymer compound and the heat-reducing material.

[0060] <Other additives> In one embodiment of the present invention, the interlayer may contain, in addition to the polymer compound, other additives other than plasticizers and heat-reducing materials. Examples of other additives include antioxidants, heat degradation inhibitors, ultraviolet absorbers, light stabilizers, lubricants, mold release agents, processing aids, foaming agents, antistatic agents, dyes, pigments, light diffusers, organic dyes, matting agents, fillers, antiblocking agents, flow promoters, melt strength enhancers, branching agents (e.g., glycerol, trimellitic acid, and anhydride), chain extenders, nucleating agents, opacifiers, glass beads, metal spheres, ceramic beads, reinforcing agents, carbon black, impact modifiers, and phosphors. These additives can be used individually or in combination of two or more. If the interlayer contains other additives, their content is not particularly limited, but may be, for example, 5% by mass or less, and preferably 3% by mass or less, relative to the total mass of the interlayer.

[0061] <Interlayer for laminated glass> The interlayer film for laminated glass of the present invention contains a first modified polymer compound, and therefore exhibits excellent glass adhesion and high stability against heat and impact. Furthermore, in one embodiment of the present invention, the interlayer film for laminated glass of the present invention may have high light transmittance.

[0062] In one embodiment of the present invention, the phosphorus concentration of the interlayer is preferably 1.8% by mass or more, more preferably 3.0% by mass or more, even more preferably 5.0% by mass or more, even more preferably 7.7% by mass or more, particularly preferably 13% by mass or more, and particularly more preferably 16% by mass or more. When the phosphorus concentration is above the lower limit of the above, it is easier to improve the glass adhesion and stability of the interlayer, and it is easier to suppress the formation of hydrogen bonds in the polymer compound, and even when a fibrous raw material is used, the raw material is easier to loosen and easier to process into an interlayer shape. Furthermore, from the viewpoint of easily maintaining the storage stability of the interlayer, the phosphorus concentration of the interlayer is preferably 23% by mass or less, more preferably 21% by mass or less, and even more preferably 19% by mass or less.

[0063] In one embodiment of the present invention, the sulfur concentration of the interlayer film is preferably 1.8% by mass or more, more preferably 3.0% by mass or more, even more preferably 5.0% by mass or more, even more preferably 7.7% by mass or more, particularly preferably 13% by mass or more, and particularly more preferably 16% by mass or more. When the sulfur concentration is above the lower limit of the above, it is easier to improve the glass adhesion and stability of the interlayer film. Furthermore, from the viewpoint of easily maintaining the storage stability of the interlayer film, the sulfur concentration of the interlayer film is preferably 20% by mass or less.

[0064] In one embodiment of the present invention, the metal ion concentration of the interlayer is preferably 0.8% by mass or more, more preferably 2.2% by mass or more, even more preferably 3.3% by mass or more, even more preferably 5.4% by mass or more, particularly preferably 6.9% by mass or more, particularly more preferably 8.0% by mass or more, and most still more preferably 10% by mass or more. Furthermore, the metal ion concentration is preferably 26% by mass or less, more preferably 25% by mass or less. When the metal ion concentration of the interlayer is within the above range, it is easier to improve the glass adhesion and stability of the interlayer, and it is easier to suppress the degradation of the polymer compound and the blackening and yellowing of the interlayer.

[0065] In one embodiment of the present invention, the interlayer film of the present invention preferably has a phosphorus concentration and / or sulfur concentration of 1.8% by mass or more, and a metal ion concentration of 0.8% by mass or more, more preferably 2.2% by mass or more, even more preferably 3.3% by mass or more, even more preferably 5.4% by mass or more, particularly preferably 6.9% by mass or more, particularly more preferably 8.0% by mass or more, and most still more preferably 10% by mass or more.

[0066] The phosphorus concentration, sulfur concentration, and metal ion concentration of the interlayer can be determined by ICP emission spectroscopy, for example, by the method described in the examples.

[0067] In one embodiment of the present invention, the moisture content of the interlayer for laminated glass is not particularly limited, but from the viewpoint of the long-term durability of the laminated glass, it is preferable that the moisture content be low, as moisture can inhibit adhesion between the interlayer and the glass interface. The moisture content of the interlayer is usually 0 to 100%, preferably 30% or less, more preferably 25% or less, even more preferably 20% or less, and particularly preferably 15% or less. The moisture content can be measured by known methods, for example, by measuring the weight of the interlayer after it has been humidified to an equilibrium state under conditions of 23°C and 50% relative humidity, and then measuring the weight of the interlayer after it has been dried overnight at 105°C, the moisture content can be calculated using the following formula. Moisture content (%) = (Weight before drying at 105°C - Weight after drying at 105°C) / (Weight before drying at 105°C) × 100 The moisture content can be adjusted by storing the product in a room with a constant temperature and humidity of 23°C and 50% RH, or by volatilizing the moisture in the interlayer using a hot air dryer or vacuum dryer.

[0068] In one embodiment of the present invention, the interlayer film of the present invention is preferably free of Class 5 hazardous materials under the Japanese Fire Service Act, from the viewpoint of easily improving the stability of the interlayer film. Examples of Class 5 hazardous materials under the Fire Service Act include organic peroxides, nitrate esters, nitro compounds, nitroso compounds, azo compounds, diazo compounds, hydrazine derivatives, hydroxylamines, hydroxylamine salts, metal azides, guanidine nitrate, 1-allyloxy-2,3-epoxypropane, 4-methylideneoxetan-2-one, and any of these.

[0069] In one embodiment of the present invention, the thickness of the interlayer film may be, for example, 0.0010 mm to 5.0 mm, preferably 0.30 mm or more, more preferably 0.40 mm or more, and even more preferably 0.45 mm or more, from the viewpoint of easily improving penetration resistance, preferably 5.00 mm or less, more preferably 3.00 mm or less, even more preferably 2.00 mm or less, even more preferably 1.50 mm or less, particularly preferably 1.00 mm or less, particularly more preferably 0.90 mm or less, and especially still more preferably 0.80 mm or less. When the thickness of the interlayer film is within the above range, it is easy to achieve both uniformity of the interlayer film thickness and adhesion to the laminated glass. The thickness of the interlayer film can be measured with a thickness gauge, and the average value measured at multiple locations (for example, 10 to 20 locations) can be adopted as the thickness of the interlayer film.

[0070] The interlayer of the present invention comprises one or more layers (hereinafter also referred to as "interlayer A") comprising a first modified polymer compound. In one embodiment of the present invention, the interlayer of the present invention may consist only of one or two or more layers of interlayer A, or it may include other resin layers on the surface of interlayer A.

[0071] Other resin layers include, for example, layers containing polyvinyl butyral (PVB) or ethylene-based ionomers, which are known to be used as interlayers for laminated glass. Laminating these other resin layers onto the surface of interlayer A tends to improve the conformability of the interlayer to the surface when laminating it with glass. From the viewpoint of reducing the total heat generated by the interlayer and improving flame resistance, the thickness of these layers other than interlayer A is preferably thin, for example, 0.0001 to 0.050 mm, preferably 0.0001 to 0.0030 mm, and more preferably 0.0001 to 0.0015 mm. If there are multiple interlayer A or other resin layers, the components constituting each layer and the thickness of each layer may be the same or different from each other. The same description regarding the thickness of the interlayer in this invention also applies to the thickness of interlayer A.

[0072] In one embodiment of the present invention, the interfilm of the present invention may be subjected to an easy-adhesion treatment on its surface. Examples of easy-adhesion treatments include surface treatments such as corona treatment, plasma treatment, and low-pressure ultraviolet treatment, or providing an adhesion aid layer by coating. Examples of adhesion aids include compounds containing at least one selected from isocyanate groups, carbodiimide groups, epoxy groups, oxazoline groups, amino groups, and silanol groups, and organosilicon compounds. Among these, it is preferable that the adhesion aid be at least one selected from compounds containing isocyanate groups (isocyanate compounds) and organosilicon compounds. Examples of organosilicon compounds include silane coupling agent condensates and silane coupling agents. Other surface treatment methods besides hydrophilization treatments include UV irradiation, electron beam irradiation, and flame treatment.

[0073] The adhesion aid layer can be formed on the interfilm by known methods. For example, a method can be used that involves coating the interfilm with an adhesion aid and drying it. The thickness of the easy-adhesion layer is preferably 1 to 100 nm, more preferably 10 to 50 nm, in a dry state. The adhesion aid used for coating may be diluted with a solvent, and the solvent is not particularly limited; for example, alcohols can be used. The dilution concentration (percentage of the mass of solids relative to the total mass of the coating solution) is not particularly limited, but is preferably 1 to 5% by mass, more preferably 1 to 3% by mass.

[0074] The interlayer for laminated glass of the present invention exhibits excellent glass adhesion even when it does not contain other resin layers or when the surface of the interlayer is not treated for easy adhesion. Therefore, in one embodiment of the present invention, the interlayer for laminated glass of the present invention may consist only of interlayer A containing the first modified polymer compound.

[0075] In one embodiment of the present invention, the interlayer film of the present invention has excellent penetration resistance. The penetration resistance of the interlayer film can be evaluated by the penetration energy. From the viewpoint of penetration resistance of the interlayer film, the penetration energy is preferably 3 J or more, more preferably 5 J or more, and even more preferably 7 J or more. The upper limit of the penetration energy is not particularly limited and may be, for example, 25 J or less. If the penetration energy of the interlayer film is equal to or greater than the above lower limit, even if a flying object collides with the laminated glass containing the interlayer film of the present invention and the laminated glass is damaged, the interlayer film is less likely to break, thereby improving safety. The penetration energy can be adjusted by the molecular weight of the polymer compound contained in the interlayer film and the thickness of the interlayer film. For example, increasing the molecular weight or increasing the thickness makes it easier to increase the penetration energy. The penetration energy can be measured by conducting a test using a drop-weight impact tester in accordance with ASTM D3763, under the conditions of a measurement temperature of 23°C, a load of 2 kg, and an impact velocity of 9 m / sec.

[0076] In one embodiment of the present invention, the tensile storage modulus of the interlayer film of the present invention, measured by tensile dynamic viscoelasticity measurement at 25 to 50°C, a frequency of 1 Hz, and a strain of <1%, is typically 0.1 to 3,000 MPa. The tensile storage modulus is preferably 50 MPa or more, more preferably 100 MPa or more, preferably 3,000 MPa or less, more preferably 2,500 MPa or less, and even more preferably 2,000 MPa or less. If the tensile storage modulus is above the lower limit, the interlayer film is less likely to bend even when thin, making it easier to process. If it is below the upper limit, it is easier to eliminate strain during bonding between the interlayer film and the glass. The tensile storage modulus can be measured by a viscoelasticity measuring device, specifically by performing tensile dynamic viscoelasticity measurement using a viscoelastic spectrometer "Rheogel-E4000" (manufactured by UBM Co., Ltd.) under measurement conditions of a frequency of 1 Hz, a measurement temperature of -50 to 250°C, and a strain of <1%. The tensile storage modulus can be adjusted by the content of components in the interlayer film. For example, if the interlayer film contains a plasticizer, it may be adjusted by the amount of plasticizer.

[0077] The optical properties of the interlayer of the present invention can be appropriately adjusted depending on the application. For example, in applications where high transmittance is preferable, it is desirable to have a high total light transmittance and excellent aesthetics. In one embodiment of the present invention, the total light transmittance of the interlayer of the present invention is preferably 50% or more, more preferably 70% or more, and even more preferably 85% or more. When the total light transmittance is above the above lower limit, the transparency of the resulting laminated glass is easily improved when the interlayer of the present invention is used as an interlayer for laminated glass. Furthermore, since transparency increases as the total light transmittance increases, there is no particular upper limit, and it may be, for example, 100%. The total light transmittance can be measured using a haze meter according to the measurement method described in JIS K7361-1.

[0078] Furthermore, for applications where translucency is preferred, such as for privacy protection in balconies of buildings, it is desirable that the optical properties of the interlayer of the present invention have a total light transmittance within a certain range. In one embodiment of the present invention, the total light transmittance of the interlayer of the present invention is preferably 10% or more, more preferably 20% or more, even more preferably 30% or more, and also preferably 90% or less, more preferably 80% or less, and even more preferably 75% or less. When the total light transmittance is within the above range, it is easy to obtain laminated glass that achieves both aesthetic appeal utilizing the luster of the glass and privacy protection. The total light transmittance can be adjusted by the thickness of the interlayer, the content of inorganic acid salts in the interlayer, or the content of additives such as pigments.

[0079] The haze of the interlayer film of the present invention can be adjusted as appropriate depending on the application. For example, in applications where aesthetics are required as well as total light transmittance, the haze is preferably 20% or less, and in applications where privacy protection is important, the haze is preferably 20% or more. The haze can be measured using a haze meter according to the measurement method described in JIS K7361-1. The haze of the interlayer film of the present invention can be measured, for example, using a haze meter SH7000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.) in accordance with JIS K7136:2000.

[0080] The interlayer for laminated glass of the present invention has excellent glass adhesion properties. The glass adhesion properties of the interlayer can be evaluated by evaluating the heat creep resistance of laminated glass obtained using the interlayer of the present invention. The heat creep resistance of the laminated glass is rated at a load of 37 kg / m². 2The thermal creep resistance can be evaluated by measuring the distance of displacement in the laminated glass when an accelerated test is conducted at 50°C for one week, and specifically, it can be evaluated by the method described in the examples below. The thermal creep resistance of the laminated glass is preferably 1 mm or less, and more preferably 0.5 mm or less. If the thermal creep resistance is below the above upper limit, it is easier to prevent problems such as thermal displacement in the laminated glass causing the installed glass to fall off or move, and the safety of the laminated glass is enhanced. The lower the thermal creep resistance, the higher the glass adhesion, so the lower limit is not particularly limited and may be 0 m or more. The glass adhesion of the interlayer can be adjusted, for example, by the content of inorganic acids and their salts in the interlayer.

[0081] In one embodiment of the present invention, the total heat generation of the interlayer film of the present invention, measured in accordance with ISO 1716, is preferably 20 MJ / kg or less, more preferably 17 MJ / kg or less, even more preferably 15 MJ / kg or less, particularly preferably 12 MJ / kg or less, especially preferably 10 MJ / kg or less, especially more preferably 8 MJ / kg or less, and especially still preferably 5 MJ / kg or less, from the viewpoint of easily improving the flame resistance of the interlayer film. When the total heat generation of the interlayer film is below the above upper limit, the interlayer film is less likely to ignite, and the flame resistance of the interlayer film is easily improved. Also, the smaller the total heat generation of the interlayer film, the less likely it is to ignite and the higher the flame resistance of the interlayer film, so the lower limit is not particularly limited and may be, for example, 0 MJ / kg or more. The total heat generation can be measured in accordance with ISO 1716, and can be measured, for example, by the method described in the examples.

[0082] The interlayer film for laminated glass of the present invention has high stability against heat and impact. The stability of the interlayer film against heat and impact can be evaluated by whether it falls under Class 5 dangerous goods of the Fire Service Act of Japan. If it does not fall under Class 5 dangerous goods of the Fire Service Act, the stability is high and the risk of causing ignition or explosion is low. Therefore, the interlayer film for laminated glass of the present invention does not fall under Class 5 dangerous goods of the Fire Service Act. Whether it falls under Class 5 dangerous goods of the Fire Service Act can be determined based on the method described in "Thermal Analysis as a Method for Determining Class 5 Dangerous Goods of the Fire Service Act", Netsu Sokutei, 16 (2), p. 90, (1989). Specifically, with the common logarithm (log(T DSC )) of the value obtained by subtracting 25 °C from the heat generation start temperature (T DSC ) on the horizontal axis and the common logarithm (logQ DSC ) of the heat generation amount (Q DSC ) measured by differential scanning calorimetry (DSC) on the vertical axis, it can be determined by a method of checking the position of the points plotted for the interlayer film, which is the test substance, with respect to the determination line (hereinafter also simply referred to as the "determination line") connecting the points plotted for 2,4-dinitrotoluene (DNT) and benzoyl peroxide (BPO), which are the standard substances (hereinafter also referred to as the "stability test"). When the point plotted for the interlayer film is located below the determination line, the interlayer film has high stability against heat and impact and does not cause explosion or ignition even when these stimuli are applied, so it is determined as "no risk", that is, "not falling under Class 5 dangerous goods of the Fire Service Act". When the point plotted for the interlayer film is located on or above the determination line, the interlayer film is determined as "risky" with risk, that is, "falling under Class 5 dangerous goods of the Fire Service Act".

[0083] Fig. 1 shows an example of the results of the stability test. In Fig. 1, the straight line connecting the points plotted for the two standard substances (BPO and DNT) represents the determination line. As shown in Fig. 1, when the point plotted for the test substance is located below the determination line, the test substance is determined as "no risk", and when the point plotted for the test substance is located on or above the determination line, the test substance is determined as "risky".

[0084] T of the interlayer film and the standard substanceDSC and Q DSC This can be measured by differential scanning calorimetry, and can be measured according to the method described in Netsu Sokutei, 16 (2), p. 90, (1989) "Thermal Analysis as a Test Method for Determining Class 5 Hazardous Materials under the Fire Service Act".

[0085] [Method for manufacturing interlayers for laminated glass] The method for manufacturing the interfilm of the present invention is not particularly limited and can be manufactured by known methods. In one embodiment of the present invention, the interfilm of the present invention is manufactured by the following steps: (I) A step of coating a support with a solution or dispersion containing a polymer compound, and (II) A step of solidifying the coating film containing the obtained polymer compound with a poor solvent. It is preferable to manufacture it by a method that includes [a specific component].

[0086] Step (I) is a step of coating a support with a solution or dispersion (dope) containing a polymer compound to form a coating film containing the polymer compound.

[0087] The solution or dispersion containing the polymer compound in step (I) can be prepared by dissolving or dispersing the polymer compound in a solvent. The solvent used to dissolve or disperse the polymer compound is not particularly limited and can be appropriately selected depending on the solubility of the polymer compound used. Examples include N,N-dimethylacetamide, lithium chloride, water, and mixed solvents thereof. Among these, a mixed solvent of N,N-dimethylacetamide and lithium chloride is preferred when the polymer compound has a phosphate group as a modifying group, which may be neutralized with metal ions, and water is preferred when the polymer compound has a sulfate group as a modifying group, which may be neutralized with metal ions.

[0088] Solutions or dispersions containing polymer compounds may, if necessary, also contain plasticizers, calorific value reducing materials, and other additives in addition to the polymer compounds.

[0089] From the viewpoint of easily reducing viscosity, the solid content concentration in a solution or dispersion containing a polymer compound may be preferably 1 to 30% by mass, more preferably 1 to 10% by mass.

[0090] The support material is not particularly limited and can be, for example, a belt-shaped or drum-shaped stainless steel with a mirror finish, a resin film such as PET film, or paper with a release agent. The method of coating the support material with a solution or dispersion containing a polymer compound is not particularly limited and can be any known method, such as gravure printing, comma coating, slit die coating, or screen printing.

[0091] Step (II) is a step in which the coating film containing the polymer compound obtained in step (I) is solidified with a poor solvent. Examples of poor solvents in step (II) include ethanol, methanol, and acetone.

[0092] After step (II), the intermediate film of the present invention can be obtained by removing the solvent from the solidified coating film obtained. The method for removing the solvent is not particularly limited and may be, for example, heat drying or vacuum drying. Furthermore, the solvent may be removed on the support, after peeling the coating film from the support, or both.

[0093] In one embodiment of the present invention, if the interlayer film of the present invention contains a plasticizer, the interlayer film containing the plasticizer may be obtained by including the plasticizer in a solution or dispersion containing a polymer compound, or the interlayer film containing the plasticizer may be obtained by impregnating an interlayer film without a plasticizer in an aqueous solution or the like containing a plasticizer.

[0094] In one embodiment of the present invention, the interfilm of the present invention may be manufactured by a method that includes a step (step (I')) of pouring a solution or dispersion containing a polymer compound into a poor solvent through a slit (hole), instead of the steps (I) and (II) described above. In step (I'), by pouring a solution or dispersion containing a polymer compound into a poor solvent through a slit of a predetermined thickness, a coating film of a predetermined thickness can be obtained without a support, and after step (I'), the interfilm of the present invention can be obtained by removing the solvent from the obtained coating film.

[0095] [Laminated glass] The present invention also includes laminated glass comprising two inorganic glass sheets and an interlayer for laminated glass of the present invention disposed between the two inorganic glass sheets. Because the laminated glass of the present invention includes the interlayer for laminated glass of the present invention, it has excellent adhesion between the interlayer and the inorganic glass, and also has high stability against heat and impact, eliminating the risk of explosion and providing high safety. Furthermore, in one embodiment of the present invention, the laminated glass of the present invention has high light transmittance.

[0096] Examples of inorganic glass that can be laminated with the interlayer of the present invention include float glass, polished plate glass, patterned glass, tempered glass, wired plate glass, or heat-absorbing plate glass. Among these, tempered glass is preferred for applications requiring high strength. The inorganic glass may be colorless or colored. The two inorganic glass sheets may be of the same type or different types.

[0097] Examples of inorganic glass materials include soda-lime glass, borosilicate glass, alkali-free glass, and quartz glass, with soda-lime glass being preferred. The two inorganic glass pieces may be of the same type or different types.

[0098] Examples of tempered glass include air-cooled tempered glass, semi-air-cooled tempered glass, and chemically strengthened glass. Semi-air-cooled tempered glass refers to glass with a lower compressive stress on the glass surface (hereinafter also referred to as surface compressive stress or CS) than air-cooled tempered glass, for example, glass with a CS of 50 MPa or less. Because air-cooled tempered glass sheets have a greater depth of compressive stress layer (hereinafter also referred to as DOL) than typical chemically strengthened glass sheets, cracks caused by flying stones, etc., are less likely to penetrate the compressive stress layer in laminated glass manufactured using air-cooled tempered glass sheets. In addition, cracks generated from cracks caused by flying stones, etc., are less likely to propagate within the glass surface in laminated glass manufactured using semi-air-cooled tempered glass sheets or chemically strengthened glass sheets.

[0099] Air-cooled tempered glass is made by rapidly cooling a uniformly heated glass plate from a temperature near its softening point, thereby creating compressive stress on the glass surface due to the temperature difference between the glass surface and the interior, and thus strengthening the glass surface. As a method for manufacturing air-cooled tempered glass, a well-known method can be employed in which glass heated to near its softening temperature is rapidly cooled, generating residual stress in the thickness direction of the glass at room temperature, thereby forming a compressive stress layer on the glass surface. Typically, the heating temperature of the glass plate is above the strain point and below the softening point of the material constituting the glass plate.

[0100] Chemically strengthened glass is glass whose surface has been strengthened through chemical treatment. One method of chemical treatment is ion exchange. In ion exchange, the glass is immersed in a treatment solution (for example, molten potassium nitrate), and compressive stress is generated on the glass surface by exchanging ions with small ionic radii (for example, sodium ions) for ions with large ionic radii (for example, potassium ions). Compressive stress is generated throughout the entire surface of the glass, forming a compressive stress layer of uniform depth across the entire surface of the glass.

[0101] The size of the CS on the glass surface and the DOL formed on the glass surface can be adjusted by the chemical treatment time and / or chemical treatment temperature, respectively. For example, at the same chemical treatment temperature, the longer the chemical treatment time, the deeper the DOL becomes. Also, at the same chemical treatment temperature, the size of the CS is initially larger at longer chemical treatment times, but then decreases. Therefore, there is no one-to-one correspondence between the size of the DOL and the size of the CS.

[0102] Glass surfaces often have invisible scratches, and in order to suppress cracking of the glass originating from these scratches, a compressive stress layer deeper than the depth of the scratch is required. From this viewpoint, a DOL of greater than 10 μm is preferable. Preferably, the DOL is 20 μm or more, and more preferably 28 μm or more.

[0103] The thickness of each inorganic glass sheet is not particularly limited and may be, for example, 0.5 to 20 mm. From the viewpoint of improving the transparency of the laminated glass and reducing its weight, it is preferably 6 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. The thicknesses of the two inorganic glass sheets may be the same or different.

[0104] In one embodiment of the present invention, the inorganic glass may not only have a flat shape, but may also have a shape having at least a bent or curved portion. For example, in the image display surfaces of devices such as televisions, personal computers, smartphones, and car navigation systems, glass with a bent or curved portion is sometimes used, and the laminated glass of the present invention can be used as such glass.

[0105] In one embodiment of the present invention, the inorganic glass may optionally have structures such as conductive structures, sound-insulating structures, design or aesthetic layers, or combinations thereof, applied to all or part of the inorganic glass, insofar as they do not hinder the objectives and effects of the present invention.

[0106] In one embodiment of the present invention, the laminated glass of the present invention may be used as a single sheet or as a combination of two or more sheets. When used as a combination of two or more sheets, the laminated glass has, for example, an inorganic glass / interlayer for laminated glass / inorganic glass / interlayer for laminated glass / inorganic glass configuration. When using two or more laminated glass sheets, the materials and thicknesses of each component of the laminated glass may be the same or different.

[0107] In one embodiment of the present invention, a spacer may be used in the laminated glass of the present invention. By using a spacer, it is possible to prevent moisture and other substances from entering the interlayer of the laminated glass. The spacer may be made of metal or alloy such as aluminum or stainless steel, or of resin. Examples of spacers include known frame-shaped spacers or hollow pipe materials used in double-glazed glass or dimming elements.

[0108] The laminated glass of the present invention can be manufactured by conventionally known methods. Examples include methods using a vacuum laminator, a vacuum bag, a vacuum ring, and a nip roll. Another method involves pre-pressing the glass using the above methods and then placing it in an autoclave for final bonding.

[0109] When using a vacuum laminator, for example, 1 × 10 -6 ~3×10 -2 Laminated glass can be manufactured by laminating inorganic glass, an interlayer for laminated glass, and inorganic glass under reduced pressure of MPa at 20-200°C, particularly at 50-160°C.

[0110] When using a vacuum bag or vacuum ring, for example, as described in European Patent No. 1235683, approximately 2 × 10 -2 Laminated glass can be manufactured by laminating inorganic glass, an interlayer for laminated glass, and inorganic glass at a temperature of 20 to 160°C under a pressure of MPa.

[0111] When using nip rolls, laminated glass can be produced by degassing the inorganic glass, the interlayer film for laminated glass, and the inorganic glass stacked together with a roll and then heating and pressing the inorganic glass, the interlayer film for laminated glass, and the inorganic glass. More specifically, for example, after heating the inorganic glass, the interlayer film for laminated glass, and the inorganic glass stacked together to 20 to 70 °C by an infrared heater or the like, degassing with a roll, and then heating to 70 to 150 °C, laminated glass can be produced by pressing the inorganic glass, the interlayer film for laminated glass, and the inorganic glass with a roll.

[0112] When autoclaving after temporary pressing by the above method for full pressing, the operating conditions of the autoclave process may be appropriately selected according to the thickness or configuration of the laminated glass. The autoclave process can be carried out, for example, at a pressure of 0.5 to 1.5 MPa and a temperature of 20 to 160 °C for 0.5 to 3 hours.

[0113] When the interlayer film for laminated glass contains other layers in addition to interlayer film A, laminated glass may be produced by bonding the interlayer film for laminated glass containing interlayer film A and other layers to the inorganic glass by the method described above, or laminated glass may be produced by stacking interlayer film A and other layers between two sheets of inorganic glass and bonding them by the method described above.

Examples

[0114] Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to the following examples.

[0115] [Phosphorus concentration] The phosphorus concentration in the interlayer film was determined by measuring the phosphorus atom content by ICP emission analysis after decomposing the interlayer film with a microwave decomposition apparatus. <Microwave decomposition> Apparatus: ETHOS UP by MILESTONE Solvent: Nitric acid Decomposition temperature: 210 °C Decomposition time: 30 minutes <ICP emission analysis> Equipment: ThermoFisher iCAP7400 Duo

[0116] [Sulfur concentration] The sulfur concentration in the interlayer was determined by measuring the sulfur atom content using ICP emission spectrometry, similar to the method used for determining the phosphorus concentration.

[0117] [Metal ion concentration] The metal ion concentration in the interlayer was determined by measuring the metal atom content using ICP emission spectrometry, similar to the phosphorus concentration.

[0118] [Degree of esterification (DS)] The degree of ester substitution was calculated using the phosphorus concentration or sulfur atom concentration obtained by ICP emission spectrometry from the following formula (1).

number

[0119] [thickness] The thickness of the interlayer was measured at 10 points using a thickness gauge, and the average value was taken as the thickness of the interlayer.

[0120] [Glass adhesion] The interlayers produced in the examples and comparative examples were cut to dimensions of 135 mm in length and 50 mm in width. Next, as shown in Figure 2, an interlayer 71 was sandwiched between two pieces of float glass 51 and 52, each measuring 165 mm in length, 50 mm in width, and 3 mm in thickness, so that 135 mm of the 165 mm length of the float glass was attached via the interlayer 71, thereby producing laminated glass 50 for glass adhesion measurement. The manufacturing procedure for the laminated glass is the same as the manufacturing procedure described in the section [Making Laminated Glass] below. Next, as shown in Figure 3, a 250g iron plate 81 was bonded to the glass 51 side of the laminated glass 50 using instant adhesive 91 to produce laminated glass 100 with the iron plate bonded to it. The laminated glass 100 with the iron plate bonded to it was placed on a stand 111 and left in a 50°C chamber for one week. After the period of time, the distance that the glass 51 had slid down was measured, and this distance was evaluated based on the following criteria, and this evaluation was used as an evaluation of the heat creep resistance. A: Laminated glass can be manufactured, and the distance the glass 51 slips down is 1 mm or less. B: Laminated glass can be manufactured, but the distance the glass 51 slips down exceeds 1 mm. C: Does not exhibit glass adhesion properties, making it impossible to manufacture laminated glass.

[0121] [Species evaluation (permeability)] The appearance of the laminated glass prepared in the examples and comparative examples was visually evaluated as follows. A: It has light transmittance that allows the printed material to be recognized through the laminated glass. B: The printed material is not recognizable through the laminated glass and is opaque.

[0122] [Stability Testing] The stability of the interlayer films obtained in the examples and comparative examples was evaluated using DSC in accordance with the description in Netsu Sokutei, 16 (2), p. 90, (1989) "Thermal Analysis as a Test Method for Determining Class 5 Hazardous Materials under the Fire Service Act". Two standard materials, DNT and BPO, and the exothermic start temperature (T) of the interlayer films obtained in the examples and comparative examples. DSC、(°C) and calorific value (Q DSC The values ​​(cal / g) were measured by sealing each sample in a high-pressure sample pan. <Measurement conditions> DSC: METTLER TOLEDO "DSC822e" Standard substances: 2,4-dinitrotoluene (DNT) and benzoyl peroxide (BPO) Pressure: Pressure increases from atmospheric pressure (initial) inside a sealed cell. Atmosphere: air Sample amount: 2 mg Heating rate: 10°C / min Sample form: Grinded into a powder Sample container: Stainless steel, sealed cell The common logarithm (log(T)) of the value obtained by subtracting 25°C from the exothermic onset temperature of DNT and BPO. DSC -25)), the common logarithm of heat generation (log(Q) DSC The values ​​were [2.46, 2.73] and [1.93, 2.43], respectively. These values ​​were the average of five measurements. Regarding DNT and BPO, log(T DSC For -25) log(Q DSC The points were plotted for DNT and BPO, and the straight line connecting these points was used as the decision line. If the plot for the interlayer was below the test line (i.e., the heat generation was below the test line), it was considered "no risk (high stability)." If it was on or above the test line (i.e., the heat generation was on or above the test line), it was considered "risk (low stability)."

[0123] [Total heat generation] The total heat generation of the interlayers obtained in the examples and comparative examples was measured according to ISO-1716. The interlayers were measured after being thoroughly dried by pre-drying under reduced pressure at 80°C and a reduced pressure of 0.1 MPa or less for at least 3 days. <Analysis of calorific value> Equipment: Ogawa Sampling Co., Ltd., Netsuken-type digital calorimeter OSK100-5 Packaging: Wrapped in ganpi paper in a cigarette-like shape. Sealing gas: Oxygen Gas pressure: 3.0 MPa Sample form: Grinded into a powder Combustion aid: Do not use

[0124] [Fabrication of interlayers] [Example 1: Phosphate-modified cellulose (CP-1)] Dissolved pulp (NSPP-HR, manufactured by Nippon Paper Industries Co., Ltd., viscosity-average molecular weight: 277,000) was thoroughly washed to remove impurities with deionized water and dried overnight in an 80°C hot air dryer. 50.0 g of dissolved pulp and 500.0 g of N,N-dimethylacetamide (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a 1-liter glass container equipped with a reflux condenser, thermometer, and anchor-shaped stirring blade, and the temperature was raised to 120°C. This solution was stirred at a rotation speed of 150 rpm for 2 hours to swell the pulp (pulp dispersion-1). A 3-liter glass container equipped with a separate reflux condenser, thermometer, and anchor-shaped stirring blade was kept below 10°C under an ice bath. 1770g of 85% phosphoric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 990g of triethyl phosphate (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into the container and stirred at 150 rpm for 30 minutes. 1250g of phosphorus pentoxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was slowly mixed into this solution, ensuring the internal temperature did not exceed 15°C. After the entire contents had been added, the glass container was purged with nitrogen and stirred at 10°C and 150 rpm for 30 minutes. Then, pulp dispersion-1 was slowly added, ensuring the internal temperature did not exceed 30°C. After the addition was complete, the temperature was raised to 30°C and the mixture was reacted under a nitrogen atmosphere for 72 hours. After the reaction, the solid and liquid components were separated by centrifugation (8000 rpm, 15 minutes). The solid component was washed multiple times with an excess amount of acetone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to remove any liquid adhering to it. The solid component was then washed multiple times with a washing solution made by adding a small amount of water to acetone. Washing was repeated until the phosphorus content in the washing solution could no longer be detected by microwave decomposition and ICP emission spectrometry (detection limit: 0.02 mass%). The washed solid component was vacuum dried to obtain phosphate-modified cellulose CP-1. The obtained CP-1 was dissolved in a mixed solvent of N,N-dimethylacetamide and lithium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) in a mass ratio of 10:1 (solid content concentration: 10.0 mass%). This solution was coated onto a support in a sheet-like manner to a predetermined thickness using a film applicator (manufactured by Tester Industry Co., Ltd.), the sheet was solidified with ethanol and the solvent was washed off, and an interlayer film of CP-1 was obtained by vacuum drying. The phosphorus concentration in the resulting interlayer film was 20.3% by mass.

[0125] [Example 2: Phosphate-modified cellulose (CP-2)] An intermediate film of phosphate-modified cellulose CP-2 was obtained in the same manner as in Example 1, except that the reaction time was changed from 72 hours to 24 hours. The phosphorus concentration in the resulting interlayer film was 15.5% by mass.

[0126] [Example 3: Sodium phosphate-modified cellulose (CP-3)] CP-1 was dispersed in deionized water to a solid content concentration of 10% by mass, and a 10N sodium hydroxide aqueous solution was added to the resulting dispersion until the pH reached 11. The dispersion was then washed multiple times with deionized water to obtain sodium phosphate-modified cellulose CP-3. This was dissolved and coated in the same manner as in Example 1 to obtain an interlayer film of CP-3. The phosphorus concentration in the resulting interlayer film was 16.9% by mass, and the sodium concentration was 24.5% by mass.

[0127] [Example 4: Sodium phosphate-modified cellulose (CP-4)] Dissolved pulp (NSPP-HR, manufactured by Nippon Paper Industries Co., Ltd., viscosity-average molecular weight: 277,000) was thoroughly washed to remove impurities with deionized water and dried overnight in an 80°C hot air dryer. 50.0 g of dissolved pulp and 587.3 g of 1-hexanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were charged into a 1-liter glass container equipped with a reflux condenser, thermometer, and anchor-shaped stirring blade, and the temperature was raised to 25°C. This solution was stirred at a rotation speed of 150 rpm for 24 hours to swell the pulp (pulp dispersion-4). A 3-liter glass container equipped with a separate reflux condenser, thermometer, and anchor-shaped stirring blade was kept below 10°C under an ice bath. 1770g of 85% phosphoric acid and 990g of triethyl phosphate were charged into the container and stirred at 150 rpm for 30 minutes. 1250g of phosphorus pentoxide was slowly mixed into this solution, ensuring the internal temperature did not exceed 15°C. After the entire amount had been charged, the glass container was purged with nitrogen and stirred at 10°C and 150 rpm for 30 minutes. Pulp dispersion-4 was then slowly added, ensuring the internal temperature did not exceed 30°C. After the addition was complete, the temperature was raised to 30°C and the mixture was reacted under a nitrogen atmosphere for 72 hours. After the reaction, the solids and liquids were separated by centrifugation (8000 rpm, 15 minutes), and the solids were washed multiple times with excess 1-hexanol, ethanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and deionized water. Washing was repeated until the phosphorus content in the washing solution could no longer be detected by microwave decomposition and ICP emission spectrometry (detection limit: 0.02 mass%). The solids after washing were vacuum dried. The obtained resin was dispersed in deionized water to a solid content concentration of 10 mass%, and a 10N sodium hydroxide aqueous solution was added to the resulting dispersion until the pH became 11. Subsequently, it was washed multiple times with deionized water to obtain sodium phosphate-modified cellulose CP-4. The obtained CP-4 was dissolved in a mixed solvent of N,N-dimethylacetamide and lithium chloride in a mass ratio of 10:1, coated into a sheet to a predetermined thickness using a film applicator (manufactured by Tester Industries Co., Ltd.), the sheet was solidified and the solvent washed off with ethanol, and then vacuum dried to obtain a sheet of phosphate-modified cellulose CP-4. The phosphorus concentration in the resulting interlayer film was 7.8% by mass, and the sodium concentration was 11.4% by mass.

[0128] [Example 5: Lithium phosphate-modified cellulose (CP-5)] A sheet of lithium phosphate-modified cellulose CP-5 was obtained in the same manner as in Example 3, except that a 10M aqueous lithium hydroxide solution was used instead of 10N sodium hydroxide. The phosphorus concentration in the resulting interlayer film was 17.8% by mass, and the lithium concentration was 7.8% by mass.

[0129] [Example 6: Lithium phosphate-modified cellulose (CP-6)] A sheet of lithium phosphate-modified cellulose CP-6 was obtained in the same manner as in Example 4, except that a 10M aqueous lithium hydroxide solution was used instead of 10N sodium hydroxide. The phosphorus concentration in the resulting interlayer film was 10.4% by mass, and the lithium concentration was 4.4% by mass.

[0130] [Example 7: Phosphate-modified resin composition (CP-7)] A sheet of sodium phosphate-modified cellulose, prepared in the same manner as in Example 3, was uniformly coated with trimethyl phosphate (manufactured by Tokyo Chemical Industry Co., Ltd., carbon content 26%) using a film applicator (manufactured by Tester Industry Co., Ltd.). The sheet was then absorbed with trimethyl phosphate to a content of 25% by mass, thereby obtaining a sheet of phosphate-modified resin composition CP-7 containing phosphate-modified cellulose and trimethyl phosphate. The phosphorus concentration in the resulting interlayer film was 18.2% by mass, and the sodium concentration was 18.4% by mass.

[0131] [Example 8: Phosphate-modified resin composition (CP-8)] A sheet of phosphate-modified resin composition CP-8 was obtained in the same manner as in Example 7, except that triethyl phosphate (manufactured by Tokyo Chemical Industry Co., Ltd., carbon content 40%) was used instead of trimethyl phosphate, and the triethyl phosphate content was set to 15% by mass. The phosphorus concentration in the resulting interlayer film was 16.9% by mass, and the sodium concentration was 20.8% by mass.

[0132] [Example 9: Sodium phosphate-modified starch (CP-9)] Phosphate-modified starch CP-9 was obtained in the same manner as in Example 1, except that starch (CAPSUL®, manufactured by Ingredion) was used instead of dissolved pulp (NSPP-HR, manufactured by Nippon Paper Industries Ltd.) and the reaction time was changed from 72 hours to 24 hours. Since phosphate-modified starch is water-soluble, an intermediate film of CP-9 was obtained in the same manner as in Example 7. The phosphorus concentration in the resulting interlayer film was 11.9% by mass.

[0133] [Example 10: Phosphate-modified cellulose (CP-10)] Dissolved pulp (NSPP-HR, manufactured by Nippon Paper Industries Co., Ltd., viscosity-average molecular weight: 277,000) was thoroughly washed to remove impurities with deionized water and dried overnight in an 80°C hot air dryer. 50.0 g of dissolved pulp and 587.3 g of 1-hexanol were charged into a 1-liter glass container equipped with a reflux condenser, thermometer, and anchor-shaped stirring blade, and the temperature was raised to 25°C. This solution was stirred at a rotation speed of 150 rpm for 24 hours to swell the pulp (pulp dispersion-10). A 3-liter glass container equipped with a separate reflux condenser, thermometer, and anchor-shaped stirring blade was kept below 10°C under an ice bath. 1770 g of 85% phosphoric acid and 990 g of triethyl phosphate were charged into the container and stirred at 150 rpm for 30 minutes. 1250 g of phosphorus pentoxide was slowly mixed into this solution, ensuring the internal temperature did not exceed 15°C. After the entire volume had been charged, the glass container was purged with nitrogen and stirred at 10°C and 150 rpm for 30 minutes. The pulp dispersion was then slowly added, ensuring the internal temperature did not exceed 30°C. After the addition was complete, the temperature was raised to 30°C and the mixture was reacted under a nitrogen atmosphere for 72 hours. After the reaction, the solids and liquids were separated by centrifugation (8000 rpm, 15 minutes), and the solids were washed multiple times with excess 1-hexanol, ethanol, and deionized water in that order. Washing was repeated until the phosphorus content in the washing solution could no longer be detected by the aforementioned microwave decomposition and ICP emission spectrometry (detection limit: 0.02 wt%). The solids after washing were vacuum-dried to obtain phosphate-modified cellulose CP-10. The obtained CP-10 was dissolved and coated in the same manner as in Example 1 to obtain a CP-10 sheet. The phosphorus concentration in the resulting interlayer film was 10.8% by mass.

[0134] [Example 11: Sulfuric acid-modified cellulose (CP-7)] Dissolved pulp (NSPP-HR, manufactured by Nippon Paper Industries Co., Ltd., viscosity-average molecular weight: 277,000) was thoroughly washed with deionized water to remove impurities and dried overnight in an 80°C hot air dryer. 15.0 g of dissolved pulp and 1410.0 g of N,N-dimethylformamide were charged into a 3-liter glass container equipped with a reflux condenser, thermometer, and anchor-shaped stirring blade, and the temperature was raised to 120°C. This solution was stirred at 150 rpm for 24 hours to swell the pulp (pulp dispersion-11). The mixture was then cooled to 10°C, and 108.9 g of fuming sulfuric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was slowly added, ensuring that the internal temperature did not exceed 30°C. After the addition, the temperature was raised to 50°C and the mixture was reacted under a nitrogen atmosphere for 3 hours. After the reaction, the mixture was cooled to 20°C, and the solid and liquid components were separated by centrifugation (8000 rpm, 15 minutes). The solid component was washed multiple times with an excess amount of acetone to remove any adhering liquid, and then washed multiple times with a washing solution of acetone and a small amount of water. Microwave decomposition and ICP emission spectrometry were performed repeatedly until the phosphorus content in the washing solution was no longer detectable (detection limit: 0.02 mass%). The washed solid component was vacuum dried. The obtained solid component was used in place of dissolved pulp, and the same procedure was repeated multiple times to obtain sulfuric acid-modified cellulose with increased reactivity. The obtained sulfuric acid-modified cellulose was dispersed in deionized water to a solid content concentration of 10 mass%, and a 10N sodium hydroxide aqueous solution was added to the resulting dispersion until the pH reached 11. The mixture was then washed multiple times with deionized water to obtain sodium sulfate-modified cellulose CP-11. Since CP-11 was water-soluble, an interlayer of CP-11 was obtained in the same manner as in Example 1, except that it was dissolved in water instead of the mixed solvent of N,N-dimethylacetamide and lithium chloride, coated into a sheet using a film applicator (manufactured by Tester Industries Co., Ltd.) to a predetermined thickness, and then vacuum-dried to obtain the sheet. The sulfur concentration in the resulting interlayer film was 19.6% by mass, and the sodium concentration was 13.9% by mass.

[0135] [Comparative Example 1: Acetate-modified cellulose (CP-11)] Cellulose triacetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was thoroughly washed to remove impurities with deionized water and dried overnight in an 80°C hot air dryer. Then, it was dissolved in dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), coated into a sheet using a film applicator (manufactured by Tester Industries Co., Ltd.) to a predetermined thickness, and hot air dried to obtain a sheet of cellulose triacetate CP-11.

[0136] [Comparative Example 2: Unmodified Cellulose (CP-12)] Dissolved pulp (NSPP-HR, manufactured by Nippon Paper Industries Co., Ltd.) was thoroughly washed to remove impurities with deionized water, then compressed and dried into a 0.8 mm thick sheet to obtain an unmodified cellulose interlayer.

[0137] [Comparative Example 3: Acetate-modified cellulose mixture (CP-13)] Cellulose triacetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was thoroughly washed to remove impurities with deionized water and dried overnight in an 80°C hot air dryer. Then, 100 parts by mass of cellulose triacetate and 10.0 parts by mass of bisphenol A bis-(diphenyl phosphate) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed in dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), coated into a sheet to a predetermined thickness using a film applicator (manufactured by Tester Industries Co., Ltd.), and hot air dried to obtain a sheet of cellulose triacetate CP-13.

[0138] [Comparative Example 4: Nitrocellulose (nitrate-modified cellulose)] A sheet of nitrocellulose CP-14 was obtained by coating a 10% collodion (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) into a sheet to a predetermined thickness using a film applicator (manufactured by Tester Industries, Ltd.), and then allowing the solvent to evaporate for one week under room temperature and humid conditions. The CP-14 sheets were dried at 80°C for 2 hours immediately before the total heat generation and stability tests.

[0139] [Fabrication of laminated glass] The interlayers prepared in the examples and comparative examples were placed between two flat pieces of float glass. After placing this in a rubber bag, it was put into a vacuum laminator (manufactured by Nisshinbo Mechatronics Inc.) and pre-bonded to the float glass and the interlayer by degassing under the conditions of a hot plate temperature of 100°C, vacuuming time of 12 minutes, press pressure of 50 kPa, and press time of 17 minutes. Next, the pre-bonded material removed from the rubber bag was compressed in an autoclave to obtain laminated glass. The autoclave conditions were a pressure of 6 bar and a temperature of 100°C for a total of no more than 90 minutes.

[0140] The properties of the interlayer films and laminated glass obtained in the examples and comparative examples were measured and evaluated according to the method described above. The results are shown in Tables 1 and 2. In the tables, the degree of esterification (DS) represents the degree of esterification of phosphate groups if the cellulose or starch in the interlayer is phosphate-modified, the degree of esterification of sulfate groups if it is sulfur-modified, the degree of esterification of acetate groups if it is cellulose acetate, and the degree of esterification of nitrate groups if it is nitrate-modified. In addition, the P concentration, S concentration, Na concentration, and Li concentration in the tables represent the phosphorus concentration, sulfur concentration, sodium concentration, and lithium concentration in the interlayer, respectively.

[0141] [Table 1]

[0142] [Table 2]

[0143] The interlayers obtained in the examples are laminated glass interlayers containing modified cellulose or modified starch as the resin, obtained by modifying non-petroleum-derived cellulose or starch. As shown in Table 1, the interlayers obtained in the examples exhibited excellent glass adhesion and could be used as laminated glass interlayers without an adhesive layer or primer layer. On the other hand, the interlayers obtained in Comparative Examples 1 to 3 did not exhibit glass adhesion, possibly because they did not have modifying groups that could interact with glass, and could not be used as laminated glass interlayers. Furthermore, the interlayers obtained in the examples were confirmed to have high stability against heat and impact. On the other hand, the interlayer obtained in Comparative Example 4 had low stability against heat and impact, and there was a risk of ignition and explosion during the manufacture of laminated glass, so it was not possible to manufacture laminated glass, and evaluation of glass adhesion and permeability could not be carried out. [Industrial applicability]

[0144] The interlayer film for laminated glass of the present invention has high stability against heat and impact, thus reducing the risk of explosion. Furthermore, it is a non-petroleum-derived interlayer film for laminated glass with excellent glass adhesion. Therefore, the interlayer film and laminated glass of the present invention can be used as environmentally friendly materials. Therefore, the interlayer film and laminated glass of the present invention can be suitably used as surface materials for laminated glass in vehicle applications (e.g., windshields, side windows, sunroofs, rear windows, head-up display glass, etc.) or in building and structural applications (e.g., laminates for facades, exterior walls or roofs, panels, doors, windows, walls, roofs, sunroofs, soundproof walls, display windows, balconies, railing walls, and other building materials, glass partitions for conference rooms, solar panels, etc.). [Explanation of symbols]

[0145] 50 Laminated glass for glass adhesion measurement 51 Float glass 52 Float glass 71 Interlayer 81 Iron Plate 91 Instant adhesive 100 Laminated glass for measuring the adhesion of glass with bonded iron plates. 111 Stand

Claims

1. An interlayer for laminated glass comprising a polymer compound having a sugar skeleton as its main chain, wherein the polymer compound is esterified with a modified polymer compound having at least one group selected from the group consisting of a phosphate group, a phosphite group, a sulfate group, a sulfite group, and salts thereof, Here, the modified polymer compound has at least one group selected from the group consisting of a phosphate group, a phosphite group, a sulfate group, a sulfite group, and salts thereof. The content of the modified polymer compound is 50% by mass or more relative to the total amount of the interlayer film for laminated glass, The degree of esterification of the modified polymer compound is 0.1 or more. The polymer compound is starch or cellulose. Interlayer for laminated glass.

2. The interlayer film for laminated glass according to claim 1, wherein at least a portion of the polymer compound is neutralized with metal ions.

3. The interlayer film for laminated glass according to claim 1 or 2, further comprising a plasticizer.

4. Laminated glass comprising two inorganic glass sheets and an interlayer for laminated glass according to any one of claims 1 to 3, disposed between the two inorganic glass sheets.

Images