Laminated glass with reduced creep at high temperatures

Abstract

The present invention relates to laminated glass comprising an interlayer based on a particular ethylene vinyl acetate-based resin composition, which is suitable for high temperature applications where polymer creep can be a problem, such as overhead architectural glazing, spandrel and bolted laminate applications, particularly where glazing temperatures can exceed 50°C or even 60°C for extended periods of time.

Description

Technical Field

[0001] The present invention relates to laminated glass suitable for high-temperature applications where creep of polymers can be a problem, such as for glazing for overhead construction, spandrels, fins, and bolted laminates, etc., particularly in places where the long-term glazing temperature can exceed 50°C, and further 60°C.

Background Art

[0002] Laminated glass is widely used for front glass, side glass, and rear glass of vehicles such as automobiles and airplanes, as well as for windows of buildings, etc., and also plays a role in reducing the scattering of glass fragments even when the glass is damaged by an external impact.

[0003] In recent years, the demand for improving the performance of laminated glass has been increasing. In particular, when using laminated glass for building structural applications (facades), it is required that the laminated glass does not allow flying objects to penetrate even when the glass is damaged, and that the laminated glass has self-supporting properties even under high-temperature conditions. In order to satisfy this required performance, it is necessary to have a desirable combination of adhesiveness and heat resistance so that the interlayer film maintains a certain elastic modulus or more.

[0004] As the interlayer film (interlayer) of laminated glass, vinyl butyral resin is used in large amounts, and a liquid plasticizer or an adhesion regulator is blended to adjust the molding processability, penetration resistance, and adhesion to glass. By blending the liquid plasticizer, the vinyl butyral resin softens and the heat resistance decreases. In addition, when the blending amount of the liquid plasticizer is reduced or not blended, although the heat resistance is improved, the molding processability decreases, so it is necessary to increase the molding temperature. Such heating increases the coloring of both the interlayer and the laminate.

[0005] Japanese Patent Publication No. 63-79741 and Japanese Patent Publication No. 2004-068013 describe the use of α-olefin-modified vinyl acetal polymers in the interlayer of laminated glass. However, these inventions do not take into consideration the problems mentioned above, such as the need to use large amounts of plasticizers, and have not resulted in any improvement.

[0006] Japanese Patent Publication No. 2011-57737 describes a sheet manufactured from polyvinyl acetal resin with an ethylene content of 0.5 to 40 mol% and an acetalization degree of 30 mol% or more. While two conventional definitions of acetalization degree exist (details of which will be discussed later), Japanese Patent Publication No. 2011-57737 does not specify a definition of acetalization degree. Therefore, the meaning of acetalization degree in Japanese Patent Publication No. 2011-57737 cannot be confirmed without actual measurement. This sheet is described as having high transparency, strength, flexibility, and suitability for use in laminated glass.

[0007] However, in the example of Japanese Patent Publication No. 2011-57737, a large amount of triethylene glycol-di-2-ethylhexanoate, a plasticizer, is used during sheet molding, at 30 parts by mass per 100 parts by mass of the polyvinyl acetal. As previously noted, using a large amount of plasticizer significantly reduces heat resistance. Furthermore, since the degree of acetalization is 30 mol% or more, there are problems with heat resistance.

[0008] Japanese Patent Publication No. 09-30846 describes a laminated glass in which a thermosetting resin, which is a mixture of an ionomer resin (in which ethylene-methacrylic acid copolymer molecules are bonded with metal ions) and an organic peroxide and a silane coupling agent, is interposed and integrated between glass plates, and the resin layer is thermoset. This laminated glass is said to have improved impact resistance and penetration resistance compared to conventional laminated glass using a polyvinyl butyral resin as the intermediate layer, and is said to have excellent impact resistance, penetration resistance, processability, and transparency. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Unexamined Patent Publication No. 63-79741 [Patent Document 2] Japanese Patent Publication No. 2004-068013 [Patent Document 3] Japanese Patent Publication No. 2011-57737 [Patent Document 4] Japanese Patent Application Publication No. 09-30846 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] However, ionomer resins are prone to whitening and poor adhesion if the temperature conditions during molding are not strictly controlled, and whitening is particularly likely if the cooling rate after melt molding is slow. For example, when laminated glass with a sheet-shaped molded body of ionomer resin sandwiched inside is cooled, whitening occurs in the center where the cooling rate is slow, and transparency decreases. Thus, laminated glass using ionomer resin requires strict control of manufacturing conditions, has high manufacturing costs, and is difficult to mass-produce industrially. [Means for solving the problem]

[0011] Summary of the Invention The present invention addresses the above problems by providing laminated glass containing an intermediate layer made from an ethylene-vinyl acetal resin composition, and here (i) The ethylene-vinyl acetal resin composition contains 80% by mass of the modified vinyl acetal resin component based on the total mass of the ethylene-vinyl acetal resin composition, (ii) The modified vinyl acetal resin component is one or more ethylene-vinyl acetal resins that contain 25 to 60 mol% ethylene units and 24 to 71 mol% vinyl alcohol units based on the total monomer units constituting the resin, and have an acetalization degree of 5 mol% or more and less than 40 mol%, (iii) The laminated glass, when measured as described in this specification, exhibits a creep of less than 1.9 mm in one month at 60°C.

[0012] In one embodiment, the ethylene-vinyl acetal resin composition substantially does not contain a plasticizer, for example, the plasticizer is 1% by mass or less based on the total mass of the ethylene-vinyl acetal resin composition.

[0013] In another embodiment, the acetyl group of the ethylene-vinyl acetyl resin is derived from one or more of butyraldehyde, benzaldehyde, and isobutyraldehyde.

[0014] In one embodiment, the intermediate layer includes an extruded film or sheet of an ethylene-vinyl acetal resin composition.

[0015] The laminated glass according to the present invention provides a desirable combination of bending strength, rigidity, optical properties, and creep properties, particularly at high temperatures exceeding 50°C or 60°C (or higher), and is thus suitable for use in various architectural and other end uses.

[0016] Therefore, in one embodiment, the laminated glass is overhead glazing.

[0017] In another embodiment, the laminated glass is a spandrel.

[0018] In another embodiment, the laminated glass is a glass fin.

[0019] In another embodiment, the laminated glass is bolted glass.

[0020] These and other embodiments, features, and advantages of the present invention will be more readily understood by those skilled in the art upon reading the following detailed description.

Brief Description of the Drawings

[0021] [Figure 1] Figure 1 is a graph showing the relationship between the degree of acetalization (DA1) of the ethylene-vinyl acetal resin used in the present invention and the assumed degree of acetalization (DA2) in JP201157737A.

Mode for Carrying Out the Invention

[0022] Detailed Description The present invention relates to a laminated glass suitable for high-temperature applications, and the laminated glass includes a plastic intermediate layer of a specific ethylene vinyl acetal resin composition described in more detail below.

[0023] In the context of this specification, all publications, patent applications, patents, and other references mentioned in this specification are hereby incorporated by reference in their entirety for all purposes as if fully set forth, unless otherwise indicated.

[0024] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. In case of conflict, this specification, including definitions, will prevail.

[0025] Unless otherwise specified, trademarks are shown in capital letters.

[0026] Unless otherwise specified, all percentages, parts, ratios, etc. are by weight.

[0027] Unless otherwise specified, the pressure expressed in psi units is gauge pressure, and the pressure expressed in kPa units is absolute pressure. However, the pressure difference is expressed as an absolute value (for example, pressure 1 is 25 psi higher than pressure 2).

[0028] Where applicable, the quantitative values ​​described herein may be determined by analytical or other measurement methods defined by reference to published or otherwise recognized standard procedures. Typical examples of such recognized standard procedure sources include ASTM (American Society for Testing and Materials, now ASTM International); ISO (International Organization for Standardization); DIN (Deutsches Institut für Normung (German Industrial Standards)); and JIS (Japanese Industrial Standards). Unless otherwise explicitly stated herein, any specific standard procedure used herein shall be considered to be the version of the procedure in effect as of the filing date of this application.

[0029] In the context of this invention, "creep" of the laminate is defined as the deflection of a rectangular laminated glass beam in a four-point bending test. The four-point bending test is based on ISO 1288-3:2016, but with some modifications to the sample size, load / support span dimensions, test temperature, and load application rate. The four-point bending test consists of loading a rectangular laminated glass sample with planar dimensions of 305 mm × 610 mm, loading it at a 150 mm span, and supporting it at a 300 mm span. The sample is kept at a temperature of 60°C and subjected to a fixed load of 1 kN for one month. The deflection of the laminate is monitored at the beam center point on the supported surface. For a laminate consisting of 3 mm glass + 0.76 mm interlayer + 3 mm glass, the maximum deflection of the laminate according to this invention is less than 1.9 mm under these test conditions.

[0030] "MFR" stands for "Melt Flow Rate," and unless otherwise specified, it is a measurement value in accordance with JIS K 7210:2014, at a temperature of 190°C and a load of 2160g.

[0031] Where a quantity, concentration, or other value or parameter is given as a range, or as a list of upper and lower limits, this should be understood as specifically disclosing all ranges formed from any pair of any upper and lower limits, regardless of whether the ranges are disclosed individually. Where numerical ranges are enumerated herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within the range. The scope of this disclosure is not intended to be limited to any specific values ​​enumerated in defining the range.

[0032] When a range of values ​​is described as "less than" or "no more than" a specified quantity (or other equivalent expression), it is important to understand that the range is limited at a lower limit by an unspecified non-zero value. Correspondingly, when a range of values ​​is described as "more than," "greater than," or "not less than" a specified quantity (or other equivalent expression), it should be understood that the upper limit is not infinite and is limited by an unspecified finite value.

[0033] When the term "approximately" is used to describe the endpoint of a value or range, the disclosure should be understood to include the specific value or endpoint being referred to.

[0034] The terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” and other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of claim elements is not necessarily limited to those elements alone and may include other elements not expressly enumerated or that are specific to such process, method, article, or apparatus.

[0035] The transitional phrase "consisting of" limits the claim to exclude any claim elements or components not specified in the claim, and, apart from impurities typically associated with them, to not include any materials other than those listed. If the phrase "consisting of" appears in a phrase in the body of the claim rather than immediately following the preamble, it limits only the elements described in that phrase; other elements are not excluded from the claim as a whole.

[0036] The transitional phrase "consisting essentially of" limits the scope of the claim to certain claimed elements, materials, or steps and other things that do not substantially affect the basic and novel features of the claimed invention. Thus, a "consisting essentially of" claim occupies an intermediate position between a closed claim written in the "consisting of" form and a fully open claim drafted in the "including" form. Any additives as defined herein (in appropriate levels for such additives), and small amounts of impurities, are not excluded from the composition by the term "consisting essentially of".

[0037] Furthermore, unless the opposite is explicitly stated, "or" and "and / or" refer to inclusiveness, not exclusivity. For example, condition A or B, or A and / or B, is satisfied by one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), or both A and B are true (or exist).

[0038] The use of “a” or “an” in describing various elements and components in this specification is solely for convenience and to give a general meaning to the disclosure. This statement should be read as including one or at least one singular, and unless it is clear that there is another meaning, singular also includes plural.

[0039] As used herein, the term “predominant portion” means that the reference material constitutes more than 50% of the total, unless otherwise defined herein. Unless otherwise specified, percentages are molar when referring to molecules (e.g., hydrogen, methane, carbon dioxide, carbon monoxide, hydrogen sulfide, etc.) and by weight otherwise (e.g., carbon content, etc.).

[0040] As used herein, the terms “substantial portion” or “substantially” mean all, almost all, or the majority, as understood by those skilled in the art in the context in which they are used, unless otherwise defined. It is intended to take into account reasonable deviations from 100% that typically occur in industrial or commercial-scale situations.

[0041] The terms "depleted" or "reduced" are synonymous with a decrease in what was originally present. For example, removing a significant portion of a material from a flow creates a material-depleted flow, where the material is effectively depleted. Conversely, the terms "enriched" or "increased" are synonymous with having more than what was originally present.

[0042] As used herein, the term “copolymer” refers to a polymer containing copolymer units resulting from the copolymerization of two or more comonomers. In this context, copolymers may be described herein in relation to their constituent comonomers or the amount thereof, for example, “a copolymer containing vinyl acetate and 15 mol% of comonomers,” or similar descriptions. Such descriptions may be considered informal in that they do not refer to comonomers as copolymer units; they do not include conventional copolymer nomenclature, such as the International Union of Pure and Applied Chemistry (IUPAC) nomenclature; they do not use product-by-process terminology; or for other reasons. However, as used herein, descriptions of copolymers in relation to their constituent comonomers or the amount thereof mean that the copolymer contains copolymer units of a particular comonomer (in the specified amount, if specified). Unless so explicitly stated in limited circumstances, copolymers are necessarily not products of a reaction mixture containing a given comonomer in a given amount.

[0043] As can be seen from the context, the term “composition” is typically used to refer to two or more polymers and / or copolymers, and possibly other types of ingredients blended or mixed with them, but it is also acceptable to use it to refer to just one of the polymers or copolymers themselves.

[0044] The terms “film” and “sheet” are interchangeable, and there is no established industry standard, but they can be defined in terms of their respective thicknesses. As sometimes used herein, the term “film” may refer to a structure having a thickness of about 10 mils (0.25 mm) or less, while the term “sheet” may refer to a structure having a thickness greater than about 10 mils (0.25 mm). Other meanings (thicknesses) may be given in the context of specific embodiments.

[0045] Where a material, method, or apparatus is described herein using the terms “known to those of skill in the art,” “conventional,” or synonyms or synonymous phrases, those terms mean that materials, methods, and apparatus that are common at the time of filing of this application are included herein. This also includes materials, methods, and apparatus that are not currently common but will become recognized in the art as suitable for similar purposes.

[0046] For convenience, many elements of the present invention may be described separately, and optional lists may be provided, and numerical values ​​may be ranges; however, for the purposes of this disclosure, this should not be considered a disclosure to any claim or a limitation to the scope of support of this disclosure of any combination of such separate components, list items, or ranges. Unless otherwise stated, each and all combinations possible in this disclosure should be considered expressly disclosed for all purposes.

[0047] Methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this disclosure, but suitable methods and materials are described herein. Therefore, the materials, methods, and examples herein are for illustrative purposes only and are not intended to be limiting unless specifically stated otherwise.

[0048] <Ethylene-vinyl acetal resin> The ethylene-vinyl acetal resin used in the present invention is obtained by acetalizing an aldehyde with an ethylene-vinyl alcohol resin (hereinafter referred to as ethylene-vinyl alcohol copolymer).

[0049] Examples of ethylene-vinyl alcohol copolymers include those obtained by copolymerizing ethylene with vinyl ester monomers and then saponifying the resulting copolymer.

[0050] Conventional methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization can be applied to copolymerize ethylene and vinyl ester monomers. Azo initiators, peroxide initiators, redox initiators, etc., can be appropriately selected as polymerization initiators depending on the polymerization method.

[0051] In saponification reactions, conventionally known alkaline or acidic catalysts can be used for alkolisis, hydrolysis, etc., but among these, saponification reactions using methanol as the solvent and caustic soda (NaOH) as a catalyst are simple.

[0052] The degree of saponification of the ethylene vinyl alcohol copolymer is not particularly limited, but is usually 95 mol% or more, or 98 mol% or more, or 99 mol% or more, or 99.9 mol% or more.

[0053] Examples of suitable vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatileate (vinyl polymer acid), vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, and vinyl benzoate. Vinyl acetate is preferred.

[0054] The ethylene unit content of ethylene vinyl alcohol copolymer is typically between 25 mol%, 30 mol%, 35 mol%, 60 mol%, 55 mol%, or 50 mol%. Lower ethylene unit content tends to reduce the impact resistance of the modified vinyl acetal resin of the present invention. Conversely, higher ethylene unit content tends to negatively affect heat resistance. By satisfying the above range, the ethylene unit content of the ethylene-vinyl acetal resin can be more precisely adjusted to achieve an appropriate balance of properties.

[0055] The MFR of ethylene vinyl alcohol copolymer at 190°C and a 2.16 kg load is generally from 1 g / 10 min, or 2 g / 10 min, or 3 g / 10 min, up to 30 g / 10 min, or up to 20 g / 10 min, or up to 10 g / 10 min. By satisfying this range, the MFR of the modified vinyl acetal resin described later can be adjusted to a suitable range.

[0056] The method for producing the ethylene-vinyl acetal resin used in the present invention is not particularly limited and can be produced by known production methods. For example, one method is to carry out an acetalization reaction by adding an aldehyde to an ethylene vinyl alcohol copolymer solution under acidic conditions, or to carry out an acetalization reaction by adding an aldehyde to an ethylene vinyl alcohol copolymer dispersion under acidic conditions.

[0057] The reaction product obtained after the acetalization reaction is neutralized with alkali, then washed with water and removed with a solvent to obtain the desired modified vinyl acetal resin.

[0058] The solvent used to produce the modified vinyl acetal resin is not particularly limited and examples include water, alcohol, dimethyl sulfoxide, and mixed solvents of water and alcohols.

[0059] The dispersion medium for producing modified vinyl acetal resin is not particularly limited, and examples include water and alcohol.

[0060] The catalyst for the acetalization reaction is not particularly limited, and either organic or inorganic acids may be used. Examples include acetic acid, p-toluenesulfonic acid, nitric acid, sulfuric acid, hydrochloric acid, and carbonic acid. In particular, inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid are preferred because they can be easily washed after the reaction.

[0061] The aldehyde used in the acetalization reaction is not particularly limited, but examples include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, hexylaldehyde, benzaldehyde, isobutyraldehyde, 2-ethylhexylaldehyde, 2-methylbutyraldehyde, trimethylacetaldehyde, 2-methylpentyaldehyde, 2,2-dimethylbutyraldehyde, 2-ethylbutyraldehyde, and 3,5,5-trimethylhexylaldehyde. Butyraldehyde, benzaldehyde, and isobutyraldehyde are preferred in terms of heat resistance and optical properties. In addition, one aldehyde may be used, or two or more may be used in combination.

[0062] The alkali used to neutralize the reaction product is not particularly limited, and examples include sodium hydroxide, potassium hydroxide, ammonia, sodium acetate, sodium carbonate, sodium bicarbonate, and potassium carbonate.

[0063] The degree of acetalization of the modified vinyl acetal resin of the present invention is typically 5 mol% or more and less than 40 mol%. In various embodiments, the lower limit of the degree of acetalization is 6 mol% or more, or 7 mol% or more, or 8 mol% or more, or 9 mol% or 10 mol% or more. If the degree of acetalization is too low, the crystallinity of the modified vinyl acetal resin tends to increase, and transparency tends to decrease. Furthermore, in other embodiments, the upper limit of the degree of acetalization is 38 mol% or less, or 36 mol% or less, or 34 mol% or less, or 32 mol% or less, or less than 30 mol%. The upper limit of the degree of acetalization may also be 29 mol% or less, or 28 mol% or less, or 27 mol% or less, or 26 mol% or less, or less than 25 mol%. If the degree of acetalization is too high, heat resistance and glass adhesion tend to be impaired.

[0064] As described above, two definitions are generally used for the degree of acetalization of ethylene-vinyl acetal resin. One is defined as the proportion of acetalized vinyl alcohol units among structural units other than ethylene units. That is, for example, it refers to the proportion of acetalized vinyl alcohol units in the sum of acetalized vinyl alcohol units, non-acetalized vinyl alcohol units, and vinyl acetate units. This degree of acetalization is determined by the following degrees of acetalization. DA1 (mol %) = {k / (k+l+m)} × 100 [In the formula, (l) is assumed to be the mole fraction of non-acetalized vinyl alcohol units, (m) the mole fraction of vinyl acetate units, and (k) the mole fraction of acetalized vinyl alcohol units.]

[0065] Another definition is the proportion of all monomer units, including ethylene units, i.e., acetalized vinyl alcohol units. That is, for example, it refers to the ratio of the sum of ethylene units, acetalized vinyl alcohol units, non-acetalized vinyl alcohol units, and vinyl acetate units to the acetalized vinyl alcohol units. This degree of acetalization is determined by the following degrees of acetalization. DA2 (mol %) = {k / (k+l+m+n)} × 100 [In the formula, (l) is assumed to be the mole fraction of non-acetalized vinyl alcohol units, (m) is assumed to be the mole fraction of acetalized vinyl alcohol units, (k) is assumed to be the mole fraction of acetalized vinyl alcohol units, and (n) is assumed to be the mole fraction of ethylene units.]

[0066] In this invention, the former DA1 is adopted as the degree of acetalization. In other words, the degree of acetalization is defined as the proportion of acetalized vinyl alcohol units among structural units other than ethylene units.

[0067] The relationship between the degree of acetalization (DA1) and the degree of acetalization (DA2) is given by equation (I): DA2 = {(100-n) / 100} × DA1 (I) [In equation (1), n ​​represents the molar ratio of ethylene units to total monomer units.] Please note that it is expressed as follows:

[0068] Figure 1 is a graph showing the relationship between the degree of acetalization (DA1) and the degree of acetalization (DA2) for n=15, 25, 32, 38, 44, 48, and 60, for example.

[0069] The degree of acetalization of the modified vinyl acetal resin of the present invention can be determined by the following procedure. First, the modified vinyl acetal resin is dissolved in ethanol, a 2N hydroxylamine hydrochloride solution and hydrochloric acid are added, the mixture is stirred in a condenser-equipped water bath for 4 hours, cooled, and then neutralized with ammonia water. After that, methanol is added to precipitate, and the mixture is washed and dried to obtain ethylene vinyl alcohol copolymer. Next, the obtained ethylene vinyl alcohol copolymer is dissolved in DMSO (dimethyl sulfoxide) at 120°C, cooled to room temperature, N,N-dimethyl-4-aminopyridine and acetic anhydride are added, and the mixture is stirred for 1 hour. The mixture is precipitated with deionized water and acetone, washed and dried to obtain ethylene vinyl acetate copolymer.

[0070] The obtained ethylene vinyl acetate copolymer is dissolved in DMSO-d6 and measured using a 400 MHz proton NMR spectrometer. From the spectrum obtained after 256 integrations, the molar ratio (n) of ethylene units in the ethylene vinyl alcohol copolymer can be calculated from the intensity ratio of methine protons (peaks at 1.1-1.9 ppm) derived from ethylene units and vinyl acetate units, and terminal methyl protons (peak at 2.0 ppm) derived from vinyl acetate units.

[0071] The molar ratios of vinyl alcohol units (l), vinyl acetate units (m), and acetalized vinyl alcohol units (k) to the total monomer units constituting the modified vinyl acetal resin are calculated using the intensity ratios of methyl protons (peaks at 1.0–1.8 ppm) derived from ethylene units, vinyl alcohol units, and vinyl ester units, and terminal methyl protons (peaks at 0.8–1.0 ppm) derived from acetal units, as well as the mole fraction (n) of the ethylene vinyl alcohol unit copolymer, from the spectra obtained by dissolving the modified vinyl acetal resin in DMSO-d6 and performing 256 cumulative measurements using a 400 MHz proton NMR spectrometer.

[0072] The degree of acetalization of the modified vinyl acetal resin is determined using the molar ratio of vinyl alcohol units (l), the molar ratio of vinyl acetate units (m), and the molar ratio of acetalized vinyl alcohol units (k), and is calculated using DA1.

[0073] Alternatively, the ethylene vinyl alcohol copolymer before the acetalization reaction is dissolved in DMSO at 120°C, cooled to room temperature, then N,N-dimethyl-4-aminopyridine and acetic anhydride are added, and after stirring for 1 hour, the copolymer is precipitated with deionized water and acetone, washed, and dried to obtain ethylene vinyl acetate copolymer.

[0074] The obtained ethylene vinyl acetate copolymer was dissolved in DMSO-d6 and measured using a 400 MHz proton NMR spectrometer. From the spectrum obtained after 256 integrations, the molar ratio (n) of ethylene units in the ethylene vinyl alcohol copolymer can be calculated from the intensity ratio of methine protons (peaks of 1.1-1.9 ppm) derived from ethylene units and vinyl acetate units, and terminal methyl protons (peak of 2.0 ppm) derived from vinyl acetate units. Note that since ethylene units are not affected by the acetalization reaction, the molar ratio (n) of ethylene units in the ethylene vinyl alcohol copolymer before the acetalization reaction is equal to the molar ratio (n) of ethylene units in the modified vinyl acetal resin obtained after the acetalization reaction.

[0075] The molar ratios of vinyl alcohol units (l), vinyl acetate units (m), and acetalized vinyl alcohol units (k) to the total monomer units constituting the modified vinyl acetal resin are calculated using the intensity ratios of methyl protons (peaks from 1.0 to 1.8 ppm) derived from ethylene units, vinyl alcohol units, and vinyl ester units, and terminal methyl protons (peaks from 0.8 to 1.0 ppm) derived from acetal units, as well as the mole fraction (n) of the ethylene vinyl alcohol unit copolymer, from the spectra obtained by dissolving the modified vinyl acetal resin in DMSO-d6 and performing 256 cumulative measurements using a 400 MHz proton NMR spectrometer.

[0076] The degree of acetalization of the modified vinyl acetal resin may be determined using the molar ratio of vinyl alcohol units (l), the molar ratio of vinyl acetate units (m), and the molar ratio of acetalized vinyl alcohol units (k), and may be calculated using DA1.

[0077] As an alternative method, the mass ratio of non-acetalized vinyl alcohol units (l0), the mass ratio of acetalized vinyl alcohol units (m0), and the mass ratio of acetalized vinyl alcohol units (k0) are determined by titration according to the method described in JIS K6728:1977, the mass ratio of non-acetalized vinyl alcohol units (l0), the mass ratio of acetalized vinyl alcohol units (m0), and the mass ratio of acetalized vinyl alcohol units (k0) are determined from n0 = 1 - l0 - m0 - k0, and from these, the molar ratio of non-acetalized vinyl alcohol units (l), the molar ratio of vinyl acetate units (m), and the molar ratio of acetalized vinyl alcohol units (k) are calculated, and the degree of acetalization is calculated from DA1.

[0078] The vinyl alcohol unit content of the modified vinyl acetal resin of the present invention is 24 to 71 mol%, based on the total monomer units constituting the resin. The lower limit of the molar ratio of vinyl alcohol units is more preferably 24.8 mol% or more, 25.6 mol% or more, 26.4 mol% or more, and 27.2 mol% or more, in that order, with 28 mol% or more being the most preferred. Note that the lower limit of the molar ratio of vinyl alcohol units may also be 26 mol% or more, 32 mol% or more, or 38 mol% or more. If the proportion of vinyl alcohol units is less than 24 mol%, the glass adhesion of the modified vinyl acetal resin of the present invention tends to be impaired. Furthermore, the upper limit of the morphological ratio of the cellular acol unit is most preferably 70.5 M% or less, 69.8 M or less, 69 M or less, more preferably 68.3 M or less, and 67.5% or less. The upper limits of the molar ratio of vinyl alcohol units may also be 65 mol% or less and 59 mol% or less. When the proportion of vinyl alcohol units exceeds 71 ​​mol%, glass adhesion improves, but transparency tends to decrease.

[0079] The mol% based on the total monomer units constituting the modified vinyl acetal resin of the present invention is calculated by converting 1 mole of acetal units to 2 moles of vinyl alcohol units. For example, in a modified vinyl acetal resin consisting of 44.0 moles of ethylene units, 44.8 moles of vinyl alcohol units, and 5.6 moles of acetal units, the ethylene units are 44.0 mol%, the vinyl alcohol units are 44.8 mol%, and the degree of acetalization is 20.0 mol%.

[0080] The MFR of the modified vinyl acetal resin of the present invention at 190°C and a 2.16 kg load is preferably in the order of 0.1 g / 10 min, or 1 g / 10 min, or 2 g / 10 min, or 3 g / 10 min, up to 100 g / 10 min, or up to 50 g / 10 min, or up to 30 g / 10 min, or up to 20 g / 10 min. If the MFR is too low, sufficient processability (fluidity) cannot be obtained in the appropriate molding temperature range during molding, requiring an increase in the molding temperature, and the resulting molded article tends to be more prone to discoloration. If the MFR is too high, sufficient melt tension cannot be obtained in the appropriate molding temperature range during molding, and problems such as deterioration of film molding stability and surface condition of the molded article tend to occur.

[0081] <Resin composition> The resin composition used in the present invention contains, based on the total mass of the resin composition, preferably 80% by mass or more (including 100%), more preferably 90% by mass or more (including 100%), and even more preferably 95% by mass or more (including 100%) of one or a combination of modified vinyl acetal resins.

[0082] In addition to the modified vinyl acetal resin, the resin composition of the present invention may optionally contain other thermoplastic resins. The other thermoplastic resins are not particularly limited and examples include (meth)acrylic resins, polyvinyl butyral resins, ionomer resins, and so on.

[0083] If the resin composition contains other thermoplastic resins, their content is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, based on the total mass of the resin composition. If the content of other thermoplastic resins in the resin composition exceeds 20% by mass, transparency, impact resistance, and adhesion to substrates such as glass tend to decrease.

[0084] The resin composition of the present invention may further contain additives such as plasticizers, antioxidants, ultraviolet absorbers, adhesion enhancers, blocking inhibitors, silane coupling agents, pigments, dyes, heat shielding materials, and functional inorganic compounds, as needed. Furthermore, if necessary, plasticizers or various additives may be extracted or washed to temporarily reduce the content of these plasticizers and additives, and then plasticizers and various additives may be added again.

[0085] If the resin composition contains additives, the amount of additives is preferably 20% by mass or less, or 15% by mass or less, or 10% by mass or less, or 5% by mass or less, based on the total mass of the resin composition. If the amount of various additives is too high, problems such as insufficient self-supporting properties (heat resistance) under high-temperature conditions and bleeding occurring when used for a long period of time as an interlayer for laminated glass are likely to occur.

[0086] In particular, plasticizers, by their nature, have a high effect of reducing self-supporting properties (heat resistance) under high-temperature conditions. Therefore, in one embodiment, the resin composition is substantially free of plasticizers, for example, its content is 1% by mass or less (including 0% by mass), or 0.5% by mass or less (including 0% by mass), or 0.1% by mass or less (including 0% by mass), based on the total mass of the resin composition.

[0087] The plasticizer used is not particularly limited, but examples include triethylene glycol-di-2-ethylhexanoate, tetraethylene glycol-di-2-ethylhexanoate, di-(2-butoxyethyl)-adipate (DBEA), di-(2-butoxyethyl)-sebacate (DBES), di-(2-butoxyethyl)-glutarate, di-(2-butoxyethoxyethyl)-adipate (DBEEA), di-(2-butoxyethoxyethyl)-sebacate (DBEES), di-(2-butoxyethyl)-azelaic acid, and di-(2-butoxyethyl Examples include di-(2-hexoxyethyl)-adipate, di-(2-hexoxyethyl)-azelaic acid, di-(2-hexoxyethyl)-glutaric acid, di-(2-hexoxyethoxyethyl)-adipate, di-(2-hexoxyethoxyethyl)-sebacate, di-(2-hexoxyethoxyethyl)-azelaic acid, di-(2-hexoxyethoxyethyl)-glutaric acid, di-(2-butoxyethyl)-phthalate and / or di-(2-butoxyethoxyethyl)-phthalate. Among these, plasticizers in which the sum of the number of carbon atoms and oxygen atoms constituting the molecule is 28 or more are preferred. Examples include triethylene glycol-di-2-ethylhexanoate, tetraethylene glycol-di-2-ethylhexanoate, di-(2-butoxyethoxyethyl)-adipate, and di-(2-butoxyethoxyethyl)-sebacate. The above plasticizers may be used individually or in combination of two or more.

[0088] Furthermore, the modified vinyl acetal resin of the present invention may contain an antioxidant. Examples of antioxidants that can be used include phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants, of which phenolic antioxidants are preferred, and alkyl-substituted phenolic antioxidants are particularly preferred.

[0089] Examples of phenolic antioxidants include acrylate compounds, such as 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, or 2,4-di-t-amyl-6-(1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl)phenyl acrylate, 2,6-di-t-butyl-4-ethylphenol, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylene-bis( 4-methyl-6-t-butylphenol), 4,4'-butylidene-bis(6-t-butyl-m-cresol), 4,4'-thiobis(3-methyl-6-t-butylphenol), bis(3-cyclohexyl-2-hydroxy-5-methylphenyl)methane, 3,9-bis(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 1,1,3-tris(2-methyl-4-hydroxyethyl) (Loxy-5-t-butylphenyl)butane, alkyl-substituted phenol compounds, e.g., 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis(methylene-3',5'-di-t-butyl-4'-hydroxyphenyl)propionate)methane or triethylene glycol bis(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate,6-(4-hydroxy-3,5-di-t-butylanilino)-2,4- Examples include bis-octylthio-1,3,5-triazines, such as triazine group-containing phenol compounds, for example, 6-(4-hydroxy-3,5-dimethylanilino)-2,4-bis-octylthio-1,3,5-triazine, 6-(4-hydroxy-3-methyl-5-t-butylanilino)-2,4-bis-octylthio-1,3,5-triazine, or 2-octylthio-4,6-bis-(3,5-di-t-butyl-4-oxyanilino)-1,3,5-triazine.

[0090] Examples of phosphorus-based antioxidants include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, tris(2-t-butyl-4-methylphenyl) phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and monophosphite compounds, such as 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or 10-decyl Examples include ruoxy-9,10-oxa-10-phosphaphenanthrene, 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-di-tridecyl phosphite), 4,4'-isopropylidene-bis(phenyl-di-alkyl(C12~C15) phosphite), 4,4'-isopropylidene-bis(diphenylmonoalkyl(C12~C15) phosphite), 1,1,3-tris(2-methyl-4-di-tridecyl phosphite-5-t-butylphenyl)butane, or diphosphite compounds, such as tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene phosphite. Among these, monophosphite compounds are preferred.

[0091] Examples of sulfur-based antioxidants include dilauryl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, lauryl stearyl 3,3'-thiodipropionate, pentaerythritol-tetrakis-(β-lauryl-thiopropionate), and 3,9-bis(2-dodecylthioethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane.

[0092] The amount of antioxidant added is preferably 0.001 to 5 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of modified vinyl acetal resin. These antioxidants may be added when manufacturing the modified vinyl acetal resin of the present invention. Alternatively, they may be added to the modified vinyl acetal resin when molding the plate-shaped molded article of the present invention.

[0093] Furthermore, the modified vinyl acetal resin of the present invention may contain an ultraviolet absorber. Examples of ultraviolet absorbers used include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α'dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, and 2-(3,5-di-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole Benzotriazole-based UV absorbers, e.g., 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole or 2'-hydroxyoctylphenyl)benzotriazole, 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate; hinderamine-based UV absorbers, e.g., bis(1,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-butylmalonate or 4-(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy)-1-(2-(3-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl)-2,2,6,6 -Tetramethylpyridine, examples include 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate or benzoate-based UV absorbers, such as hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate. The amount of these UV absorbers added is preferably in the range of 10 to 50,000 ppm, more preferably 100 to 10,000 ppm, based on the mass of the modified vinyl acetal resin. Furthermore, two or more of these UV absorbers may be used in combination. These UV absorbers may be added during the production of the modified vinyl acetal resin of the present invention. Alternatively, they may be added to the modified vinyl acetal resin when molding the plate-shaped molded articles of the present invention.

[0094] Furthermore, the modified vinyl acetal resin of the present invention may contain an adhesion improver. Examples of adhesion improvers that can be used include those disclosed in International Publication No. 03 / 033583, with alkali metal salts and / or alkaline earth metal salts of organic acids being preferred, particularly potassium acetate and / or magnesium acetate. Other additives, such as silane coupling agents, may also be added. The optimal amount of adhesion improver varies depending on the additive used and the application of the resulting module and laminated glass. However, it is preferable to adjust the amount so that the adhesive strength in the Panmel test (described in International Publication No. 03 / 033583, etc.) of the resulting sheet is typically 3 to 10. If high penetration resistance is required, the amount should be adjusted to 3 to 6, and if high glass shatter resistance is required, the amount should be adjusted to 7 to 10. When high glass shatter resistance is required, omitting the adhesion improver is also a useful method.

[0095] Furthermore, the modified vinyl acetal resin of the present invention may contain a silane coupling agent. Examples of adhesion enhancers that can be used include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyldiethoxysilane, and N-(2-aminoethyl)-3-aminopropyldiethoxysilane.

[0096] These silane coupling agents may be used individually or in combination of two or more. The amount of silane coupling agent is preferably 0.001 to 5 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of modified vinyl acetal resin. These silane coupling agents may be added when manufacturing the modified vinyl acetal resin of the present invention. Alternatively, they may be added to the modified vinyl acetal resin when molding the plate-shaped molded article of the present invention.

[0097] When a laminated glass is manufactured by incorporating heat-shielding fine particles or a heat-shielding compound as a heat-shielding material into the interlayer of the present invention, thereby imparting a heat-shielding function to the laminate, the transmittance of solar infrared radiation can be adjusted.

[0098] Suitable heat-shielding particles are disclosed, for example, in U.S. Patent Application Publication No. 2017 / 0320297.

[0099] Specific examples of heat-shielding microparticles include metal-doped indium oxide, e.g., tin-doped indium oxide (ITO), metal-doped tin oxide, e.g., antimond-doped tin oxide (ATO), metal-doped zinc oxide, e.g., aluminum-doped zinc oxide (AZO), general formula: M m WO n Examples of metal element composite tungsten oxide, zinc antimonate (ZnSb2O5), lanthanum hexaboride, etc., are represented by (M representing a metal element; m is approximately 0.01 to approximately 1.0; n is approximately 2.2 to approximately 3.0). Among these, ITO, ATO, and metal element composite tungsten oxide are preferred, and metal element composite tungsten oxide is more preferred. Examples of metal elements represented by M in metal element composite tungsten oxide include Cs, Tl, Rb, Na, K, etc., with Cs being particularly preferred. From the viewpoint of heat shielding properties, m is preferably approximately 0.2 or more, or approximately 0.3 or more, and preferably approximately 0.5 or less, or approximately 0.4 or less.

[0100] From the viewpoint of the transparency of the final laminate, the average particle diameter of the heat-shielding fine particles is preferably about 100 nm or less, or about 50 nm or less. Note that in this specification, the average particle diameter of the heat-shielding particles refers to the particle diameter measured by a laser diffraction device.

[0101] In the final resin composition, the content of heat-shielding fine particles is preferably about 0.01% by weight or more, or about 0.05% by weight or more, or about 0.1% by weight or more, or about 0.2% by weight, relative to the weight of the resin. Furthermore, the content of heat-shielding fine particles is preferably about 5% by weight or less, or about 3% by weight or less.

[0102] Examples of heat-shielding compounds include phthalocyanine compounds and naphthalocyanine compounds. From the viewpoint of further improving heat-shielding properties, it is preferable that the heat-shielding compound contains a metal. Examples of metals include Na, K, Li, Cu, Zn, Fe, Co, Ni, Ru, Rh, Pd, Pt, Mn, Sn, V, Ca, Al, etc., with Ni being particularly preferred.

[0103] The content of the heat-shielding compound is preferably about 0.001% by weight or more, or about 0.005% by weight or more, or about 0.01% by weight or more, based on the weight of the resin. Furthermore, the content of the heat-shielding compound is preferably about 1% by weight or less, or about 0.5% by weight or less.

[0104] The colored intermediate layer can be formed as is commonly known in the art.

[0105] For example, one or more pigments can be added to the resin composition, as is generally disclosed in U.S. Patent Application Publication No. 2008 / 0302461.

[0106] Blends of one or more inorganic particles and one or more dyes can also be used.

[0107] In some cases, it may be desirable to form a translucent intermediate layer in order to produce a laminate having the aesthetic properties of etched or sandblasted glass, for example, as disclosed in U.S. Patent No. 7,261,943, or having a translucent white appearance, as disclosed in U.S. Patent Application Publication No. 2013 / 0225746.

[0108] Decorative laminated glass with images can also be prepared, for example, as described in U.S. Patent No. 7,232,213.

[0109] <Interlayer (sheet or film)> The storage modulus (E') of the modified vinyl acetal resin or plate-shaped molded article containing the same according to the present invention, under the conditions of a measurement temperature of 50°C and a frequency of 1 Hz, is preferably 20 to 1000 MPa, more preferably 30 to 900 MPa, and even more preferably 40 to 800 MPa. When the storage modulus (E') is within the above range, the self-supporting properties are further improved. In the present invention, the storage modulus (E') was measured by the method described in the examples.

[0110] The method for producing the intermediate is not particularly limited, and known methods can be used. Specifically, the resin composition may be formed into a sheet or film by extrusion molding, press molding, blow molding, injection molding, solution casting, etc. In particular, a method is preferred in which the resin composition and additives are supplied to an extruder, kneaded, melted, and removed from the mold to form a sheet or film. The resin temperature during extrusion is typically from about 170°C, or from about 180°C, or from about 190°C to about 250°C, or to about 240°C, or to about 230°C. If the resin temperature is too high, the modified vinyl acetal resin will decompose, increasing volatile substances and increasing discoloration. Conversely, if the temperature is too low, extrusion becomes very difficult, and the volatile content also increases. In order to efficiently remove volatile substances, it is preferable to remove them by reducing the pressure from the vent port of the extruder.

[0111] In order to prevent adhesion between intermediate layers during manufacturing and storage, and to improve degassing performance in the lamination process described later, it is preferable to have irregularities on the surface of the interlayer film of the present invention. Furthermore, it is preferable that an irregular structure such as melt fractures and / or embossing is formed on the surface of the interlayer film of the present invention by conventionally known methods. The shape of the melt fractures or embossing is not particularly limited, and conventionally known shapes can be used.

[0112] Preferably, such a structure is provided on at least one side (more preferably both sides) of the interlayer for the laminated glass.

[0113] Examples of methods for forming the surface of an interlayer for laminated glass include, for example, the conventionally known embossing roll method, the shape extrusion method, and the extrusion lip embossing method using melt fracture. Among these, the embossing roll method is preferred in order to stably obtain an interlayer for laminated glass having uniform and fine irregularities formed on the interlayer.

[0114] Embossed rolls used in the embossing roll method can be manufactured, for example, by transferring a desired relief pattern to the surface of a metal roll using an engraving mill (mother mill) with a suitable relief pattern. Embossed rolls can also be manufactured using laser etching. Furthermore, after forming a fine relief pattern on the surface of the metal roll as described above, the surface with the fine relief pattern can be blast-treated using an abrasive such as aluminum oxide, silicon oxide, or glass beads to form an even finer relief pattern.

[0115] Furthermore, it is preferable that the embossing rolls used in the embossing roll method are subjected to a release treatment. If embossing rolls that have not been subjected to a release treatment are used, it becomes difficult to peel the interlayer film for laminated glass from the embossing rolls. Examples of release treatment methods include known methods such as silicone treatment, Teflon® treatment, and plasma treatment.

[0116] The depth of the recesses and / or the height of the protrusions (hereinafter sometimes referred to as "embossed height") on the surface of the interlayer for laminated glass formed by the embossing roll method or the like is preferably about 5 μm or more, or about 10 μm or more, or about 20 μm or more. When the embossed height is about 5 μm or more, when laminated glass is manufactured, air bubbles present at the interface between the interlayer for laminated glass and the glass are less likely to remain, and as a result, the appearance of the laminated glass tends to be good.

[0117] The height of the embossed portion is preferably about 150 μm or less, or about 100 μm or less, or about 80 μm or less. When the height of the embossed portion is about 150 μm or less, the adhesion between the interlayer for laminated glass and the glass is good when laminated glass is manufactured, which tends to result in a good appearance of the laminated glass.

[0118] In this invention, the height of the embossed portion refers to the maximum height roughness (Rz) as defined in JIS B 0601 (2001). The height of the embossed portion can be measured, for example, using the confocal principle of a laser microscope. The height of the embossed portion, i.e., the depth of the recess or the height of the protrusion, can be changed without departing from the spirit of this invention.

[0119] Examples of shapes that can be imparted by methods such as embossing rolls include grids, oblique grids, oblique ellipses, ellipses, oblique grooves, and grooves. Among these, oblique grids and oblique grooves are preferred from the viewpoint of better releasing air bubbles. The inclination angle is preferably 10° to 80° with respect to the film flow direction (MD direction).

[0120] The shaping process, such as the embossing roll method, may be performed on one side or both sides of the interlayer for laminated glass, but it is more preferable to perform it on both sides. Furthermore, the shaped pattern may be a regular pattern, an irregular pattern such as a random matte pattern, or a pattern as disclosed in U.S. Patent No. 7,351,468.

[0121] The thickness of the interlayer in the present invention is not particularly limited, but is preferably from about 0.10 mm, or from about 0.40 mm, or from about 0.70 mm to about 3.0 mm, or from about 2.8 mm, or from about 2.6 mm. If the interlayer is too thin, it tends to be difficult to satisfy the penetration resistance performance of the laminated glass, and if the interlayer is too thick, the cost of the sheet itself increases and the cycle time of the lamination process increases, which is undesirable. The interlayer may be a single layer, or the desired thickness can be adjusted by using two or more layers.

[0122] The penetration resistance of the film or sheet of the present invention is preferably such that the penetration energy in the drop-weight impact test described later is 11 J or more, more preferably 13 J or more, and even more preferably 15 J or more. If the penetration resistance of the plate-shaped molded body is too low, a sufficient value cannot be obtained for the penetration resistance of laminated glass using the plate-shaped molded body as an intermediate film, making it difficult to use.

[0123] The film or sheet of the present invention is useful as an interlayer for laminated glass. Interlayers for laminated glass are particularly preferred as interlayers for structural laminated glass from the viewpoint of adhesion to substrates such as glass, transparency, and self-supporting properties. Furthermore, while suitable as an interlayer for laminated glass in various applications such as automobiles and other mobile devices, buildings, and solar cells, the invention is not limited to these applications.

[0124] <Laminated glass> Laminated glass can be manufactured by inserting the interlayer film of the present invention between two or more pieces of glass made from inorganic or organic glass and laminating them. The glass to be laminated with the interlayer film for laminated glass of the present invention is not particularly limited. The thickness of the glass is not particularly limited, but is preferably from about 1 mm, or from about 2 mm to about 10 mm, or from about 6 mm.

[0125] The glass used can be either inorganic or organic. Examples of inorganic glass include not only window glass, plate glass, silicate glass, low-iron glass, tempered glass, tempered CeO-free glass, and float glass, but also colored glass, specialty glass (e.g., glass containing components to control solar heat), coated glass (e.g., glass sputtered with metal (e.g., silver or indium tin oxide) for sunlight control), E-glass, Toro glass, and Solex® glass (PPG Industries, Pittsburgh, Pennsylvania). Such specialty glasses are disclosed, for example, in U.S. Patents 4,615,989, 5,173,212, 5,264,286, 6,150,028, 6,340,646, 6,461,736, and 6,468,934. The type of glass selected for a particular laminate depends on its intended use.

[0126] Examples of organic glass include, but are not limited to, polycarbonate, acrylic, polyacrylate, cyclic polyolefin (e.g., ethylene norbornene polymer), polystyrene (preferably metallocene-catalyzed polystyrene), polyamide, polyester, fluoropolymer, and combinations of two or more thereof.

[0127] The interlayer used in the laminated glass of the present invention may consist only of a layer (x) containing the above-mentioned modified resin composition, or it may be a multilayer film containing at least two layers (x). The multilayer film is not particularly limited and examples include a two-layer film in which layer (x) and other layers are laminated, and a three-layer film in which other layers are arranged between two layers (x).

[0128] Other layers include layers containing known resins. Examples of resins that can be used include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, polytetrafluoroethylene, acrylic resin, polyamide, polyacetal, polycarbonate, polyester, polyethylene terephthalate, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, polyarylate, liquid crystal polymer, polyimide, etc. Furthermore, other layers may optionally contain additives such as plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, antiblocking agents, pigments, dyes, heat shielding materials (e.g., inorganic heat shielding materials and organic heat shielding materials having infrared absorption capabilities), and functional inorganic compounds.

[0129] Known methods can be used to laminate the above-mentioned laminated glass, such as using a vacuum laminator, a vacuum bag, a vacuum ring, or a nip roll. Additionally, a process involving immersion in an autoclave after temporary bonding can also be added.

[0130] When using a nip roll, for example, one method is to perform the first temporary bonding at a temperature below the flow initiation temperature of the modified vinyl acetal resin, and then perform further temporary bonding under conditions close to the flow initiation temperature. Specifically, for example, one method is to heat the mixture to about 30°C to about 70°C using an infrared heater, degas it with a roll, heat it further to about 50°C to about 120°C, and then press it with a roll to bond or temporarily bond it.

[0131] The autoclave process, which is performed after the initial bonding, is carried out for approximately 2 hours at a temperature of approximately 130°C to 145°C and a pressure of approximately 1 MPa to 5 MPa, depending on the thickness and configuration of the module and laminated glass.

[0132] The laminated glass of the present invention preferably exhibits excellent transparency. Haze is the percentage of light beam scattered at a specific angle. For example, when the laminated glass is slowly cooled under the conditions described later, the haze is preferably 2% or less, or 1.6% or less, or 1.2% or less. The haze can be measured using a haze meter in accordance with ISO 14782.

[0133] The laminated glass of the present invention preferably exhibits excellent adhesion to the glass. For example, the peel stress in the compressive shear strength test by the method described later is preferably 20 MPa, or 22 MPa, or 24 MPa to 40 MPa, or 38 MPa, or 36 MPa. If the peel stress is too low, the adhesion between the glass and the interlayer is insufficient, and the glass tends to shatter when it breaks. If the peel stress is too high, the adhesion between the glass and the interlayer is too strong, which may reduce the resistance to penetration when the glass breaks.

[0134] When the laminated glass of the present invention contains a heat-shielding material, the transmittance at a wavelength of 1,500 nm is preferably about 50% or less, or about 20% or less. If the transmittance at a wavelength of 1,500 nm is about 50% or less, the infrared shielding rate increases, and the heat-shielding performance of the laminated glass tends to improve.

[0135] Heat / shielding and solar radiation protection can also be provided by the use of low-E glass and / or IR reflection technology, as is generally known to those skilled in the art, for example, as disclosed in U.S. Patent No. 7,291,398.

[0136] <Final use> The laminated glass of the present invention has excellent transparency, impact resistance, formability, heat resistance, and creep behavior, making it suitable and reliable for high-temperature applications where other conventional materials may have limited reliability. Because of its excellent transparency, impact resistance, heat resistance, and formability, the laminated glass of the present invention is suitable for use in building materials such as automobile windshields, automobile side windows, automobile sunroofs, automobile rear windows, head-up display glass, facades, laminates for exterior walls and roofs, panels, doors, windows, walls, sunroofs, soundproof walls, display windows, balconies, railing walls, etc., as well as partition glass materials for conference rooms, solar panels, and the like.

[0137] In particular, the laminates of the present invention can be applied to overhead glazing, spandrels, fins, and bolted glass applications, which are particularly high-temperature sensitive end applications using typical intermediate layer materials.

[0138] Overhead glazing is used in a variety of situations. For example, conventional overhead glazing systems such as walkways and canopies generally include multiple horizontal frame members or purlins interconnected to form a structural frame unit, vertical frame members or rafters, and pressure plates mounted on top to hold glass panels in place on the frame members. U.S. Patent No. 8,356,454. Overhead glazing is particularly susceptible to interlayer creep, which can cause glazing failure and, in the worst case, loss of adhesion of glass panels, increasing the risk of glass falling. The risk of failure, especially at high temperatures, can be reduced by using the low-creep interlayer and laminated glass of the present invention.

[0139] In buildings of two stories or more, the spandrel is the area between the window frame and the top of the window below it. Spandrel panels are most often used to conceal interior parts of a building that are not necessarily aesthetically pleasing when viewed from the outside. Examples of such interior parts include building frame members, heating and air conditioning ducts, tubing or plumbing, and electrical cables or conduits. In addition to concealing the interior of a building, spandrel panels typically aesthetically complement or harmonize the windows of the glass system with other attributes of the building. Details regarding laminated spandrel panels and their use are generally well known to those skilled in the art, as exemplified, for example, in European Patent No. 2517877 and other publications cited therein. Similar to overhead glazing, breakage of the spandrel panel can occur due to interlayer creep, particularly at high temperatures; however, this risk can be reduced by using the low-creep interlayer and laminated glass of the present invention.

[0140] Glass fins are used to support glass-clad facades and increase their rigidity. They also function as supports for glass roofs. Because structural integrity is required, loss of laminate integrity due to creep can lead to glass falling or fatal damage. The risk of damage can be reduced by using the low-creep interlayer and laminated glass of the present invention.

[0141] Bolt-fastened glass systems (also known as direct point attachment glazing) are also generally known to those skilled in the art, as exemplified, for example, in U.S. Patent Application Publication No. 2006 / 0005482. Conventional bolt-fastened systems typically require low-creep inserts and bushings between the bolts and the interlayer to ensure the bolt tension is maintained; otherwise, interlayer creep can loosen the bolts over time, causing potential structural problems, especially in high-temperature applications. The use of such bushings increases the cost and complexity of lamination manufacturing, but this can be partially or entirely avoided by using the low-creep interlayer and laminate of the present invention. [Examples]

[0142] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0143] <Determination of ethylene units, vinyl alcohol units, acetal units, and degree of acetalization> The ethylene vinyl alcohol copolymer before the acetalization reaction was dissolved in DMSO at 120°C, cooled to room temperature, and then N,N-dimethyl-4-aminopyridine and acetic anhydride were added and the mixture was stirred for 1 hour. Precipitation was performed with deionized water and acetone, followed by washing and drying to obtain ethylene vinyl acetate copolymer. The obtained ethylene vinyl acetate copolymer was dissolved in DMSO-d6, and the molar ratio (n) of ethylene units in the ethylene vinyl acetate copolymer was calculated from the intensity ratio of methine protons (peaks of 1.1-1.9 ppm) derived from ethylene units and vinyl acetate units, and terminal methyl protons (peak of 2.0 ppm) derived from vinyl acetate units, from the spectrum obtained by measuring the ethylene vinyl acetate copolymer with 256 integration cycles using a 400 MHz proton NMR spectrometer. Here, since ethylene units are not affected by the acetalization reaction, the molar ratio (n) of ethylene units in the ethylene vinyl alcohol copolymer before the acetalization reaction is treated as being equal to the molar ratio (n) of ethylene units in the modified vinyl acetal resin obtained after the acetalization reaction.

[0144] The molar ratios of vinyl alcohol units (l), vinyl acetate units (m), and acetalized vinyl alcohol units (k) relative to the total monomer units constituting the modified vinyl acetal resin were calculated using the intensity ratios of methyl protons (peaks of 1.0-1.8 ppm) derived from ethylene units, vinyl alcohol units, and vinyl ester units, and terminal methyl protons (peaks of 0.8-1.0 ppm) derived from acetal units, as well as the molar ratio (n) of the ethylene vinyl alcohol unit copolymer, from the spectrum obtained by dissolving the modified vinyl acetal resin in DMSO-d6 and integrating it 256 times using a 400 MHz proton NMR spectrometer.

[0145] The degree of acetalization (DA1) of the modified vinyl acetal resin was determined using the molar ratio of vinyl alcohol units (l), the molar ratio of vinyl acetate units (m), and the molar ratio of acetalized vinyl alcohol units (k) determined above.

[0146] <Rigidity evaluation under high-temperature conditions> The molten mixture of the resin composition obtained by the method described later was heated at 200°C and 50 kgf / cm². 2 A 0.8 mm thick sheet was obtained by compression molding at a pressure of 5 minutes. A 40 mm x 5 mm test piece was cut from the sheet, and the storage modulus (E') was measured using a dynamic viscoelasticity analyzer manufactured by UBM Corporation under conditions of a measurement temperature of 50°C and a frequency of 1 Hz. The obtained value serves as an indicator of the rigidity of the interlayer for laminated glass under high-temperature environments.

[0147] <Evaluation of penetration resistance> The molten mixture of the resin composition obtained by the method described later was heated at 200°C and 50 kgf / cm². 2 A 0.8 mm thick sheet was obtained by compression molding at a pressure of 5 minutes. A 60 mm x 60 mm test specimen was cut from the sheet and tested using a drop weight impact tester (CEAST9350, Instron Co., Ltd.) 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 / s. Penetration energy was calculated from the area of ​​the SS curve from the moment the striker edge contacts the test specimen (test force is sensed) to the moment of penetration (test force returns to zero) and passing through (test force returns to zero).

[0148] <Evaluation of film moldability> The resin composition obtained by the method described later was used to produce a 0.8 mm thick, 50 cm wide sheet by forming a film using a 40 mm diameter full-flight single-screw extruder and a 60 cm wide coated hanger die at a barrel temperature of 200 °C. The film molding stability was observed, and if film molding could be performed continuously without problems and a sheet with a good appearance was obtained, it was evaluated as A. If problems such as tearing or loosening of the sheet occurred and a sheet with a good appearance was not obtained, it was evaluated as B.

[0149] <Evaluation of glass adhesion> The molten paste of the resin composition obtained by the method described later was heated at 210°C and 50 kgf / cm². 2A 0.8 mm thick sheet was obtained by compression molding at a pressure of 0.8 mm for 5 minutes. The obtained sheet was sandwiched between two 2.7 mm thick float glass sheets, and an intermediate laminate was obtained by reducing the pressure at 100°C for 1 minute using a vacuum laminator (Nisshinbo Mechatronics Co., Ltd. 1522N), pressing at 30 kPa for 5 minutes while maintaining the degree of reduced pressure and temperature. The obtained intermediate laminate was placed in an autoclave and treated at 140°C and a pressure of 1.2 MPa for 30 minutes to obtain the final laminated glass. The obtained laminated glass was cut to a size of 25 mm x 25 mm to obtain test samples. The obtained test samples were evaluated by the compression shear strength test (compression shear strength test) described in International Publication No. 1999 / 058334. The maximum shear stress when peeling the laminated glass was used as an indicator of glass adhesion.

[0150] <Transparency Assessment> The laminated glass obtained by the above method was heated to 140°C and then slowly cooled to 23°C at a rate of 0.1°C / min. After that, the haze of the laminated glass was measured. The haze was measured according to ISO 14782 using a haze meter (HZ-1, manufactured by Suga Test Instruments Co., Ltd.).

[0151] <Example 1: Synthesis of Modified Vinyl Acetal Resin> 100 parts by weight of ethylene vinyl alcohol copolymer chips having 44 mol% ethylene units, 99% degree of saponification, and an MFR of 5.5 g / 10 min, synthesized according to the method described in Japanese Patent Publication No. 2016-28139, were dispersed in 315 parts by weight of 1-propanol. The temperature of the solution was raised to 60°C while stirring, 40 parts by weight of 1M hydrochloric acid was added, and then 16.7 parts by weight of n-butyraldehyde was added to disperse the solution. The acetalization reaction was then carried out while maintaining the temperature at 60°C. As the reaction progressed, the chips dissolved, and a homogeneous solution was obtained. After holding for 36 hours from the start of the reaction, 6.4 parts by weight of sodium bicarbonate was added to stop the reaction. 500 parts by weight of 1-propanol was added to the reaction solution to homogenize it, and then 2000 parts by weight of water was added dropwise to precipitate the resin. Subsequently, the filtration and washing operations were repeated three times, and the solution was vacuum dried at 60°C for 8 hours to obtain a modified vinyl acetal resin. The resulting modified vinyl acetal resin had an ethylene unit content of 44 mol% and a degree of acetalization of 31 mol%.

[0152] The modified vinyl acetal resin obtained above was melt-kneaded for 3 minutes at a chamber temperature of 200°C and a rotation speed of 100 rpm using a lab-plastidomill (device name "4M150", manufactured by Toyo Seiki Co., Ltd). The contents of the chamber were removed and cooled to obtain a molten mixture. Various physical properties were evaluated using the obtained molten mixture. The results are shown in Table 1.

[0153] <Examples 2-6> Each modified vinyl acetal resin was obtained in the same manner as in Example 1, except that the ethylene units of the ethylene vinyl alcohol copolymer used, the amount of MFR and n-butyraldehyde added, and the reaction time were changed as shown in Table 1. These mixtures were melt-kneaded in the same manner as in Example 1 to obtain a molten kneaded product. Various physical properties were evaluated using the obtained molten kneaded product. The results are shown in Table 1.

[0154] <Example 7> Modified vinyl acetal resins were obtained in the same manner as in Example 2, and a molten compound was obtained in the same manner as in Example 1, except that 8 parts by weight of triethylene glycol-di-2-ethylhexanoate per 100 parts by weight of the modified vinyl acetal resin was added as a plasticizer. Various physical properties were evaluated using the obtained molten compound. The results are shown in Table 1.

[0155] [Table 1]

[0156] <Comparative Examples 1-4> Each modified vinyl acetal resin was obtained in the same manner as in Example 1, except that the ethylene units of the ethylene vinyl alcohol copolymer used, the MFR, the amount of added n-butyraldehyde, and the reaction time were changed as shown in Table 2. A molten kneaded product was then obtained in the same manner as in Example 1. Various physical properties were evaluated using the obtained molten kneaded product. The results are shown in Table 2.

[0157] <Comparative Example 5> 1700 parts by weight of a 7.5% aqueous solution of vinyl alcohol resin with a degree of saponification of 99%, 74.6 parts by weight of butyraldehyde, and 0.13 parts by weight of 2,6-di-t-butyl-4-methylphenol were charged, and the mixture was cooled to 14°C. 160.1 parts by weight of 20% by mass hydrochloric acid was added to initiate the acetalization reaction. Ten minutes after the completion of hydrochloric acid addition, the temperature was raised to 65°C over 90 minutes, and the reaction was carried out for a further 120 minutes. After that, the mixture was cooled to room temperature, the precipitated resin was filtered, and washed with deionized water (10 times with 10 times the amount of deionized water relative to the resin). Then, the mixture was thoroughly neutralized with a 0.3% by mass aqueous solution of sodium hydroxide, and the mixture was further washed 10 times with 10 times the amount of deionized water relative to the resin, dehydrated, and dried to obtain vinyl butyral resin.

[0158] The vinyl butyral resin obtained above was melt-kneaded in the same manner as in Example 1 to obtain a molten compound. Various physical properties were evaluated using the obtained molten compound. The results are shown in Table 2.

[0159] <Comparative Example 6> A vinyl butyral resin was obtained in the same manner as in Comparative Example 5, except that 30 parts by weight of triethylene glycol-di-2-ethylhexanoate was added as a plasticizer to 100 parts by weight of vinyl butyral resin, and a molten compound was obtained in the same manner as in Comparative Example 7. Various physical properties were evaluated using the obtained molten compound. The results are shown in Table 2.

[0160] <Comparative Example 7> According to the method described in Example 1 of Japanese Patent Publication No. 201157737, 100 g of polyvinyl alcohol having an ethylene content of 15 mol%, a degree of saponification of 98 mol%, and an average degree of polymerization of 1700 was stirred in 900 g of distilled water. However, the polyvinyl alcohol did not dissolve, and a 10% by weight aqueous solution of polyvinyl alcohol could not be obtained, making it impossible to carry out the acetalization reaction.

[0161] <Comparative Example 8> A modified vinyl acetal resin was obtained using the method described in Example 1 of Japanese Patent Application Publication No. 201157737, with polyvinyl alcohol having an ethylene content of 15 mol%, a degree of saponification of 98 mol%, and an average degree of polymerization of 1700, along with n-butyraldehyde, and 1-propanol as the solvent, with the reaction conditions modified according to Example 1 of this specification. The degree of acetalization of the obtained modified vinyl acetal resin was 73 mol%, which did not match the degree of acetalization of 64.5 mol% described in Japanese Patent Application Publication No. 201157737. On the other hand, the acetal units of the obtained modified vinyl acetal resin were 62 mol%, which was close to the degree of acetalization of 64.5 mol% described in Japanese Patent Application Publication No. 201157737.

[0162] From this, it can be concluded that the degree of acetalization in Japanese Patent Publication No. 201157737 represents the ratio of acetalized vinyl alcohol units to the acetal units, i.e., the total monomer units, and that Japanese Patent Publication No. 201157737 uses a different degree of acetalization than that of the present invention.

[0163] Next, a molten compound was obtained in the same manner as in Example 1 of Japanese Patent Publication No. 201157737. Various physical properties were evaluated using the obtained molten compound. The results are shown in Table 2.

[0164] [Table 2] Preferred embodiments of the present invention include the following: [1] Laminated glass comprising an intermediate layer made from an ethylene-vinyl acetal resin composition, (i) The ethylene-vinyl acetal resin composition contains 80% by mass or more of modified vinyl acetal resin components based on the total mass of the ethylene-vinyl acetal resin composition, (ii) The modified vinyl acetal resin component is one or more ethylene-vinyl acetal resins that contain 25 to 60 mol% ethylene units and 24 to 71 mol% vinyl alcohol units based on the total monomer units constituting the resin, and have an acetalization degree of 5 mol% or more and less than 40 mol%, (iii) The laminated glass exhibits creep of less than 1.9 mm at 60°C for one month, as measured according to this specification. Laminated glass. [2] The ethylene-vinyl acetal resin composition substantially contains no plasticizer, or optionally contains a plasticizer in an amount of 1% by mass or less (including 0% by mass), 0.5% by mass or less (including 0% by mass), or 0.1% by mass or less (including 0% by mass), based on the total mass of the resin composition, as described in [1]. [3] The ethylene-vinyl acetate resin composition comprises a plasticizer in an amount of 20% by mass or less, or 15% by mass or less, or 10% by mass or less, or 5% by mass or less, based on the total mass of the resin composition, as described in [1]. [4] The ethylene-vinylacetyl resin contains an acetyl group, the acetyl group is derived from one or more butyraldehyde, benzaldehyde and isobutyraldehyde, as described in any of [1] to [3]. [5] The resin composition comprises a heat-shielding material as an additive, as described in any of [1] to [4]. [6] The laminated glass according to [5], wherein the heat-shielding material is either heat-shielding fine particles or a heat-shielding compound or both. [7] The laminated glass according to any one of [1] to [6], wherein the intermediate layer comprises an extruded film or sheet of an ethylene-vinyl acetal resin composition. [8] The laminated glass according to [7], wherein the structure is provided on at least one or both sides of the intermediate layer. [9] The laminated glass according to [8], wherein the structure is an embossed structure.

[10] Laminated glass described in any of [1] to [9], which is overhead glazing.

[11] A spandrel, a laminated glass as described in any of [1] to [9].

[12] Fins, which are laminated glass as described in any of [1] to [9].

[13] A bolted glazing, which is a laminated glass as described in any of [1] to [9].

Claims

1. Laminated glass comprising an intermediate layer made from an ethylene-vinyl acetal resin composition, (i) The ethylene-vinyl acetal resin composition contains 80% by mass or more of modified vinyl acetal resin components based on the total mass of the ethylene-vinyl acetal resin composition, (ii) The modified vinyl acetal resin component is one or more ethylene-vinyl acetal resins, which, based on the total monomer units constituting the resin, contain 25 to 60 mol% ethylene units and 24 to 71 mol% vinyl alcohol units, and the degree of acetalization, defined as the proportion of acetalized vinyl alcohol units among structural units other than ethylene units, is 5 mol% or more and less than 40 mol%. (iii) In the case of the laminated glass consisting of a 3 mm glass + 0.76 mm interlayer + 3 mm glass, in a four-point bending test according to ISO 1288-3:2016, when a rectangular laminated glass sample with planar dimensions of 305 mm × 610 mm was loaded at a 150 mm span and supported at a 300 mm span, the sample was kept at a temperature of 60°C, and a fixed load of 1 kN was applied for one month, it showed creep of less than 1.9 mm. The aforementioned resin composition includes a heat-shielding material as an additive. Laminated glass.

2. The laminated glass according to claim 1, wherein the ethylene-vinyl acetal resin composition does not contain a plasticizer, or optionally contains a plasticizer in an amount of 1% by mass or less (including 0% by mass), 0.5% by mass or less (including 0% by mass), or 0.1% by mass or less (including 0% by mass), based on the total mass of the resin composition.

3. The laminated glass according to claim 1, wherein the ethylene-vinyl acetal resin composition contains a plasticizer in an amount of 20% by mass or less, or 15% by mass or less, or 10% by mass or less, or 5% by mass or less, based on the total mass of the resin composition.

4. The laminated glass according to any one of claims 1 to 3, wherein the ethylene-vinyl acetal resin contains an acetyl group, and the acetyl group is derived from one or more butyraldehyde, benzaldehyde, and isobutyraldehyde.

5. The laminated glass according to any one of claims 1 to 4, wherein the heat-shielding material is heat-shielding fine particles or a heat-shielding compound, or both.

6. The laminated glass according to any one of claims 1 to 5, wherein the intermediate layer comprises an extruded film or sheet of an ethylene-vinyl acetal resin composition.

7. The laminated glass according to claim 6, wherein at least one or both sides of the intermediate layer are provided with an uneven surface structure.

8. The laminated glass according to claim 7, wherein the structure is an embossed structure.

9. A laminated glass according to any one of claims 1 to 8, which is an overhead glazing.

10. A spandrel, as described in any one of claims 1 to 8.

11. A fin, made of laminated glass according to any one of claims 1 to 8.

12. Laminated glass according to any one of claims 1 to 8, which is a bolted glazing.

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