JPWO2015040663A1 - Sheet containing polyvinyl acetal - Google Patents

Abstract

Even when using a high boiling point, low polarity plasticizer and storing it for a long time with a relatively high water content, it is equivalent to using it before storage as an interlayer film for laminated glass It aims at obtaining the sheet | seat which expresses the adhesiveness to glass, and an external appearance. The sheet contains a polyvinyl acetal, a plasticizer having a molecular weight of 380 or more, and a silicon-containing compound. The plasticizer having a molecular weight of 380 or more is 30 to 70 parts by weight with respect to 100 parts by weight of the polyvinyl acetal, and the sheet has a thickness of 0.2 to 2 mm. When the sheet is analyzed by ICP emission spectrometry, 0.10 to 30 ppm of silicon is detected, and silicon secondary ions detected when TOF-SIMS measurement is performed in a cross section parallel to the thickness direction of the sheet. Providing sheets that meet certain conditions.

Description

  The present invention relates to a sheet containing polyvinyl acetal and its use.

  Sheets made of polyvinyl acetal and a plasticizer are widely used as interlayer films for laminated glass because of their excellent adhesion and transparency to glass and mechanical strength.

  When using a sheet made of polyvinyl acetal and a plasticizer as an interlayer film for laminated glass, a high-boiling plasticizer is preferable from the viewpoint of suppressing the volatilization of the plasticizer when used over a long period of time or at a high temperature. Used. In particular, triethylene glycol di-2-ethylhexanoate (3GO) has been widely used in recent years because it has a high boiling point, is compatible with polyvinyl acetal, and is excellent in the plasticizing effect of polyvinyl acetal. However, 3GO is a low polarity compound, and a sheet containing polyvinyl acetal and 3GO tends to be easily charged. Since charged sheets are likely to adsorb dust present in the storage environment, when such sheets are stored for a long period of time and used as an interlayer film for laminated glass, laminated glass having an appearance problem may be obtained. . In order not to cause such a problem, a sheet containing polyvinyl acetal and 3GO may be adjusted to a relatively high water content, for example, about 0.5 to 0.9%, and stored in a state where it is difficult to be charged. .

  By the way, in the laminated glass, the adhesiveness between the interlayer film for laminated glass and the glass must be appropriately adjusted according to the purpose. As a method of adjusting the adhesion between the interlayer film for laminated glass and the glass, a method of adding an alkali metal salt of carboxylic acid, an alkaline earth metal salt of carboxylic acid or the like to the interlayer film for laminated glass is known ( For example, see Patent Documents 1 to 3). However, when the laminated glass including the interlayer film for laminated glass to which such a carboxylate is added is used under high humidity, if the carboxylate is a salt of a carboxylic acid having a small carbon number, Water absorption may cause the edge of the laminated glass to whiten. Further, when the carboxylate is a salt of a carboxylic acid having a large number of carbon atoms, the problem of whitening is suppressed, but it is not sufficient, and the adhesion between the interlayer film for laminated glass and the glass over time There was a change. Patent Documents 1 to 3 disclose an interlayer film for laminated glass in which a carboxylic acid and a carboxylic acid metal salt are used in combination. When such an interlayer film is used, the problem of change in the adhesive property with time is On the other hand, hydrolysis of polyvinyl acetal occurred using carboxylic acid, which is an essential component, as a catalyst, and odor problems sometimes occurred due to the generated aldehyde. Such an odor problem is particularly noticeable when the interlayer film is stored at a relatively high water content.

  On the other hand, as a method for suppressing whitening when the interlayer film for laminated glass absorbs moisture, silicon-containing compounds such as silicone oil (see, for example, Patent Documents 4 to 7) and silane coupling agents (for example, see References 8 to 10) There is known a method for adjusting the adhesion between the interlayer film for laminated glass and the glass by adding s. In the laminated glass including such an interlayer film for laminated glass, whitening due to moisture absorption of the interlayer film for laminated glass is unlikely to occur even under high humidity.

  By the way, when silicon-containing compounds such as silicone oil and silane coupling agents are used for the interlayer film for laminated glass, the silicon-containing compounds are applied to the surface of the interlayer film or kneaded into the interlayer film. However, when these interlayer films are stored for a long time under high humidity, for example, in the case of an interlayer film for laminated glass coated with a silicon-containing compound, the silicon-containing compound moves into the interlayer film over time. Therefore, the interlayer film for laminated glass stored for a long time may not exhibit the same adhesion to glass as the interlayer film before storage. On the other hand, when the silicon-containing compound is kneaded and used in the intermediate film, when such an intermediate film is stored for a long period of time, the silicon-containing compound is gelled in the intermediate film, and the appearance of the laminated glass obtained using this, In particular, the appearance when intense light such as an automobile headlight is irradiated may be impaired.

JP 05-186250 A Japanese Patent Laid-Open No. 07-041340 Japanese Patent Laid-Open No. 08-119687 Japanese Patent Laid-Open No. 50-121311 Japanese Patent Laid-Open No. 10-139499 JP 2000-007386 A JP 2000-203899 A Japanese Patent Application Laid-Open No. 07-068054 JP 07-237942 A Japanese Patent Application Laid-Open No. 08-026786

  This invention provides the sheet | seat which solves said subject, Uses the high boiling point and low polarity plasticizer like 3GO, and used for laminated glass what was stored for a long time with the comparatively high moisture content. Even if it is a case where it is used as an intermediate film, it aims at obtaining the sheet | seat which expresses the adhesiveness to glass, and an external appearance equivalent to the case where the thing before storage is used.

  According to the present invention, the object includes a polyvinyl acetal, a plasticizer having a molecular weight of 380 or more, and a silicon-containing compound, and a plasticizer having a molecular weight of 380 or more is 30 to 70 parts by weight with respect to 100 parts by weight of the polyvinyl acetal. When the sheet is 0.2 to 2 mm, 0.10 to 30 ppm of silicon is detected when the sheet is analyzed by ICP emission spectrometry, and TOF-SIMS measurement is performed in a cross section parallel to the thickness direction of the sheet In addition, the total number of silicon secondary ions detected from the region having a thickness of 0 to 60 μm and a width of W μm from at least one surface of the sheet is N (0 to 60), and 10 to 10 in the thickness direction from the surface. The total number of silicon secondary ions detected from the region of 60 μm and width W μm is N (10 to 60), and 60 to 110 μm and width W μm in the thickness direction from the surface. 5/6 × N (0-60) / N (60-110) is 1.2 or more when the total number of silicon secondary ions detected from the region is N (60-110), 5 This is achieved by providing a sheet in which / 6 × N (0-60) / N (10-60) is 0.8-2.

  The sheet preferably contains an alkali metal salt and / or an alkaline earth metal salt.

  The alkali metal salt and / or alkaline earth metal salt is preferably an alkali metal salt of carboxylic acid or an alkaline earth metal salt of carboxylic acid.

  The carboxylic acid is preferably a carboxylic acid having 1 to 8 carbon atoms.

  The content of the alkali metal salt and / or alkaline earth metal salt is preferably 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the polyvinyl acetal.

  The silicon-containing compound is preferably a compound containing a silicon-oxygen bond.

  The silicon-containing compound is preferably a silane coupling agent.

  The silicon-containing compound is preferably a silicone oil.

  The plasticizer having a molecular weight of 380 or more is preferably triethylene glycol di-2-ethylhexanoate.

  After producing the sheet, it is preferred that the total storage time at a temperature exceeding 30 ° C. is less than 3000 hours.

  The viscosity average polymerization degree of polyvinyl acetal existing in a region of 0 to 60 μm in the thickness direction from the surface of the sheet, and the viscosity average polymerization degree of polyvinyl acetal existing in a region of 60 to 110 μm in the thickness direction from the surface. The difference is preferably 0-500.

  Silicon contained in sheet A, obtained by laminating sheet A containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound, and sheet B containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound The concentration of the contained compound is higher than the concentration of the silicon-containing compound contained in the sheet B, and the difference between the degree of acetalization of the polyvinyl acetal contained in the sheet A and the degree of acetalization of the polyvinyl acetal contained in the sheet B is 0 to 3 mol%. It is preferable that

  Silicon contained in sheet A, obtained by laminating sheet A containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound, and sheet B containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound The concentration of the containing compound is higher than the concentration of the silicon-containing compound contained in the sheet B, and the difference between the average residual hydroxyl group content of the polyvinyl acetal contained in the sheet A and the average residual hydroxyl group content of the polyvinyl acetal contained in the sheet B is 0-3. It is preferable that it is mol%.

Silicon contained in sheet A, obtained by laminating sheet A containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound, and sheet B containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound the concentration of the containing compound is higher than the concentration of the silicon-containing compound contained in the sheet B, and highest plasticizer content of the plasticizer contained in the sheet a and the plasticizer a _1, often a second content plasticizer agent and plasticizer a _2, the content of the plasticizer a ₁ with respect to 100 parts by mass of the polyvinyl acetal contained in the sheet a and (a ₁₎ part by weight, the content of the plasticizer a ₂ for the polyvinyl acetal 100 parts by (a ₂₎ as a mass parts, further, the highest plasticizer content of the plasticizer contained in the sheet B and a plasticizer B _1, the content of two More plasticizer to the eye as a plasticizer B _2, the content of the plasticizer B ₁ for the polyvinyl acetal 100 parts by weight contained in sheet B and (b ₁₎ part by weight, the plasticizer B ₂ with respect to the polyvinyl acetal 100 parts by When (b ₂ ) parts by mass of (b ₂ ), (a ₂ ) / (a ₁ ) and (b ₂ ) / (b ₁ ) are 0 to 0.1, and | [(a1) + ( a2)] − [(b1) + (b2)] | ≦ 10.

  According to the present invention, the object includes a polyvinyl acetal, a plasticizer having a molecular weight of 380 or more, and a silicon-containing compound, and a plasticizer having a molecular weight of 380 or more is 30 to 70 parts by weight with respect to 100 parts by weight of the polyvinyl acetal. When the sheet is 0.2 to 2 mm, 0.10 to 30 ppm of silicon is detected when the sheet is analyzed by ICP emission spectrometry, and TOF-SIMS measurement is performed in a cross section parallel to the thickness direction of the sheet In addition, the total number of silicon secondary ions detected from a region having a thickness of 0 to X μm and a width of W μm from at least one surface of the sheet is defined as N (0 to X), and X / The total number of silicon secondary ions detected from a region of 6 to X μm and a width of W μm is N (X / 6 to X), and X to 11 X / 6 μm and a width of W μm in the thickness direction from the surface. When the total number of silicon secondary ions detected from N is X (X to 11X / 6), 5/6 × N (0 to X) / N (X to 11X / 6) is 1.2 or more. Yes, 5/6 × N (0 to X) / N (X / 6 to X) is 0.8 to 2, and X is 20 to 90 μm.

  According to the present invention, the above object is preferably achieved by providing a laminated glass including the sheet.

  In the sheet of the present invention, when TOF-SIMS measurement is performed on a cross section parallel to the thickness direction of the sheet, it is detected from a region having a width of 0 to 60 μm and a width of W μm from at least one surface of the sheet. The total number of secondary ions is N (0 to 60), the total number of silicon secondary ions detected from the surface in the thickness direction of 10 to 60 μm and the width W μm is N (10 to 60), 5/6 × N (0-60) / N (where N (60-110) is the total number of silicon secondary ions detected from the surface in the thickness direction of 60-110 μm and width W μm. 60 to 110) is 1.2 or more, which is 0 to 60 μm in the thickness direction from the surface of the sheet as compared to the inside of the sheet represented by the region of 60 to 110 μm in the thickness direction from the surface of the sheet. Of the sheet surface represented by the area Beside, silicon-containing compound at a high concentration represents a be distributed. By setting 5/6 × N (0-60) / N (60-110) to 1.2 or more, the adhesion with glass is appropriately achieved by the action of the silicon-containing compound present at a high concentration in the vicinity of the sheet surface. The problem of appearance due to the gelation of the silicon-containing compound can be suppressed while adjusting to the above.

  The sheet of the present invention has 5/6 × N (0 to 60) / N (10 to 60) of 0.8 to 2, which is in the thickness direction from the surface in the vicinity of the sheet surface. The concentration of the silicon-containing compound present in the region of 0 to 60 μm and the portion excluding the region of 0 to 10 μm out of the region of 0 to 60 μm in the thickness direction from the surface, that is, 10 to 60 μm in the thickness direction from the surface This indicates that the concentration of the silicon-containing compound existing in the region does not change significantly. Therefore, in the sheet of the present invention, since the silicon-containing compound existing in a very shallow region in the thickness direction of the sheet does not easily migrate to the inside of the sheet, the adhesive force changes even when the sheet of the present invention is stored for a long period of time. Is unlikely to occur.

It is a figure showing the measurement object area | region of TOF-SIMS measurement in the cross section parallel to the thickness direction of a sheet | seat.

  First, the polyvinyl acetal used in the present invention will be described. The polyvinyl acetal used in the present invention is not particularly limited, and the degree of polymerization, the degree of acetalization, the average residual hydroxyl group amount, and the vinyl ester residue amount are not particularly limited. For example, when the polymerization degree is expressed using the viscosity average polymerization degree of polyvinyl alcohol as a raw material as an index, the viscosity average polymerization degree is preferably 200 to 3000, more preferably 500 to 2400, and 1000 to 2000. More preferably. When the viscosity average degree of polymerization exceeds 3000, the processability of the sheet of the present invention may be reduced, and when the viscosity average degree of polymerization is less than 200, the mechanical strength of the obtained sheet may be reduced, or silicon content may be reduced. Compound migration tends to occur.

  The degree of acetalization of the polyvinyl acetal is not particularly limited, but is preferably 40 to 85 mol%, more preferably 60 to 80 mol%, and further preferably 67 to 75 mol%. If the degree of acetalization is less than 40 mol%, the flexibility of the resulting sheet will be insufficient, and the compatibility with plasticizers and silicon-containing compounds having a molecular weight of 380 or more contained in the sheet will be reduced, resulting in transparency. May decrease. On the other hand, when the degree of acetalization exceeds 85 mol%, the mechanical strength of the obtained sheet is reduced, or when the sheet is stored for a long period of time, dealdehydes occur due to hydrolysis of polyvinyl acetal, and odor problems are likely to occur. Tend to be.

  The average residual hydroxyl group content of polyvinyl acetal is preferably 10 to 50 mol%, more preferably 19 to 39 mol%, and still more preferably 24 to 32 mol%. When the average residual hydroxyl group amount exceeds 50 mol%, the compatibility with a plasticizer having a molecular weight of 380 or more may be lowered, and when it is less than 10 mol%, the mechanical strength of the resulting sheet may be lowered.

  The amount of the vinyl ester residue of polyvinyl acetal is preferably 0.01 to 20 mol%, more preferably 0.1 to 10 mol%, and further preferably 0.2 to 3 mol%. Those having a vinyl ester residue content of less than 0.01 mol% are difficult to produce industrially at low cost, and those having a vinyl ester residue content of more than 20 mol% are those having a vinyl ester residue during long-term storage. The group may be hydrolyzed to generate, for example, carboxylic acid such as acetic acid, and the carboxylic acid may be used as a catalyst to hydrolyze the polyvinyl acetal to generate an aldehyde that causes odor.

  The polyvinyl acetal used in the present invention is produced from, for example, polyvinyl alcohol that can be obtained by a conventionally known method or conventionally known modified polyvinyl alcohol.

  The polyvinyl acetal used in the present invention is produced by a conventionally known method. For example, first, an aqueous solution of polyvinyl alcohol having a concentration of 3 to 40% by mass is maintained in a temperature range of 80 to 100 ° C., and then the aqueous solution is gradually cooled over 10 to 60 minutes. When the temperature is lowered to −10 to 30 ° C., an aldehyde and an acid catalyst are added, and an acetalization reaction is performed for 30 to 300 minutes while keeping the temperature constant. At that time, polyvinyl alcohol having a certain degree of acetalization is deposited. Thereafter, the reaction solution is heated to a temperature of 30 to 80 ° C. over 30 to 300 minutes, and the temperature is maintained for 10 to 500 minutes. Next, a basic compound is added to the reaction solution, the acid catalyst is neutralized, washed with water, and dried to obtain polyvinyl acetal.

  The acid catalyst used in the acetalization reaction is not particularly limited, and any of organic acids and inorganic acids can be used. Examples thereof include acetic acid, paratoluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid. Of these, hydrochloric acid, sulfuric acid, and nitric acid are preferably used. Moreover, although the aldehyde used for acetalization reaction is not specifically limited, It is preferable to acetalize with the conventionally well-known aldehyde of C1-C8, and especially a C4-C6 aldehyde is preferable, especially n-butyraldehyde. Is preferably used. In this invention, the polyvinyl acetal obtained by using together 2 or more types of aldehydes can also be used, and 2 or more types of polyvinyl acetals obtained using different aldehydes can also be mixed and used.

  Next, the plasticizer used in the present invention will be described. The plasticizer having a molecular weight of 380 or more used in the present invention is not particularly limited. For example, triethylene glycol di-2-ethylhexanoate (3GO, molecular weight 402), tetraethylene glycol di-2-ethylhexanoate (4GO, molecular weight 446). ), Aliphatic ester compounds such as dinonyl adipate (molecular weight 398), dioctyl sebacate (molecular weight 426), aromatic ester compounds such as dioctyl phthalate (molecular weight 396), adipic acid and 3-methyl-1, A conventionally known polyester compound having a molecular weight of 380 or more, such as a polyester compound obtained by copolymerization with 5-pentanediol, can be used. Among these compounds, those having a molecular weight of 380 to 2000 are preferred, those having a molecular weight of 390 to 1000 are more preferred, and those having a molecular weight of 400 to 600 are more preferred. When the molecular weight of the plasticizer is less than 380, the silicon-containing compound contained as an essential component in the present invention quickly shifts to the inside of the sheet (in the sheet thickness direction, the same applies hereinafter), thereby achieving the object of the present invention. I can't. Moreover, when the molecular weight of the plasticizer exceeds 2000, the compatibility with the polyvinyl acetal is poor, the transparency of the resulting sheet may be impaired, and the plasticizing effect on the polyvinyl acetal is not sufficiently exhibited. There is. In addition, the chemical structure of the plasticizer of the present invention is not particularly limited, but from the viewpoint of appropriately adjusting the adhesion between the sheet of the present invention and glass, at least one functional group selected from a hydrocarbon group, an ether bond and an ester bond. A plasticizer containing only groups is preferred. The plasticizer used in the present invention is triethylene glycol di-2-ethylhexanoate because it is difficult for the silicon-containing compound to move into the sheet and is excellent in compatibility with polyvinyl acetal and plasticizing effect on polyvinyl acetal. It is best to be an eate.

  In the sheet of the present invention, the plasticizer content is preferably 30 to 70 parts by mass, more preferably 31 to 60 parts by mass, and 32 to 50 parts by mass with respect to 100 parts by mass of the polyvinyl acetal. More preferably it is. If the plasticizer content is less than 30 parts by mass, the flexibility of the sheet may not be sufficient, and if the plasticizer content is more than 70 parts by mass, the strength and transparency of the sheet may be reduced. There is a tendency that the silicon-containing compound contained in is easily transferred into the sheet. In addition, as will be described later, when the sheet A and the sheet B are laminated to obtain the sheet of the present invention, the same is applied to the entire sheet with respect to 100 parts by mass of the polyvinyl acetal included in the entire sheet composed of the sheet A and the sheet B. It is preferable to make content of the plasticizer contained into 30-70 mass parts.

  Next, the silicon-containing compound used in the present invention will be described. The silicon-containing compound used in the present invention is not particularly limited as long as it does not contradict the gist of the present invention. However, a compound containing a silicon-oxygen bond is preferable from the viewpoint of adjusting the adhesion to glass, and in particular, a silane coupling agent. Silicone oil or the like is preferably used. The silane coupling agent is not particularly limited, but methyltrimethoxysilane, hexyltrimethoxysilane, phenyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane And conventionally known silane coupling agents such as 3-glycidyloxypropyltriethoxysilane, vinyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane. Among these, those having an epoxy group or an amino group are particularly preferable from the viewpoint of adjusting the adhesive force with glass.

  Examples of the silicone oil include conventionally known silicone oils such as dimethyl silicone, methylphenyl silicone, amino group-modified silicone, alkyl group-modified silicone, polyether group-modified silicone, and carboxyl group-modified silicone. Amino group-modified silicone, polyether group-modified silicone, and carboxyl group-modified silicone are preferred from the viewpoint of adjusting the adhesion to glass.

  The silicon content in the sheet of the present invention is 0.10 to 30 ppm, preferably 0.20 to 25 ppm, and preferably 0.30 to 20 ppm, when analyzed by ICP emission spectrometry. More preferred. When the silicon content is less than 0.10 ppm as the silicon detection amount when the sheet is analyzed by ICP emission spectrometry, the effect of adjusting the adhesive force is insufficient, and when the silicon detection amount exceeds 30 ppm, When the sheet is stored for a long period of time, the silicon-containing compound may gel and the appearance of the resulting laminated glass may be impaired. The content of silicon in the sheet of the present invention was determined by cutting a sheet sample in a plane parallel to the cross section in the thickness direction, adding sulfuric acid and nitric acid, thermally decomposing, and then using a solution with a constant volume of hydrochloric acid. And it can carry out by measuring with an ICP emission spectrometer (Optima4300DV by Perkin Elmer).

  In the present invention, the TOF-SIMS measurement of the sheet can be performed by the method described in the examples using, for example, the apparatus described in the examples.

  In the sheet of the present invention, when TOF-SIMS measurement is performed in a cross section parallel to the thickness direction of the sheet, silicon 2 detected from a region having a thickness of 0 to X μm and a width of W μm from at least one surface of the sheet. The total number of secondary ions is N (0 to X), and the total number of silicon secondary ions detected from the region of X / 6 to X μm and width W μm in the thickness direction from the surface is N (X / 6 to X). ), And the total number of silicon secondary ions detected from the region of X to 11X / 6 μm and width W μm in the thickness direction from the surface is N (X to 11X / 6), 5/6 × N (0 to X) / N (X to 11X / 6) is 1.2 or more, and 5/6 × N (0 to X) / N (X / 6 to X) is 0.8 to 2. Here, X can be appropriately designed according to the thickness of the sheet, and is 20 to 90 μm, and preferably 20 to 80 μm.

  More specifically, for example, as shown in FIG. 1, in a cross section parallel to the thickness direction of the sheet 1, 0 to 110 μm in the thickness direction from the surface of the sheet 1, and in a direction parallel to the surface of the sheet 1. The area | region which consists of a rectangle of W micrometer is an area | region used as the measuring object of TOF-SIMS measurement. The sheet of the present invention is detected from a region to be measured (hereinafter referred to as a measurement target region) 2a (see FIG. 1A) having a thickness of 0 to 60 μm and a width W μm from at least one surface of the sheet 1. The total number of silicon secondary ions to be detected is N (0 to 60), and is detected from the measurement target region 2b (see FIG. 1B) having a thickness of 10 to 60 μm and a width W μm from the surface. The total number of secondary ions is N (10 to 60), and silicon secondary ions detected from the measurement target region 2c (see FIG. 1 (c)) having a thickness of 60 to 110 μm and a width of W μm from the surface. 5/6 × N (0-60) / N (60-110) is 1.2 or more, where N is a total number of N (60-110). 5/6 × N (0-60) / N (60-110) is preferably 1.3-20, more preferably 1.4-10, and more preferably 1.5-8. Further preferred. By reducing 5/6 × N (0-60) / N (60-110) to 1.2 or more, the adhesiveness with glass is appropriately adjusted, and the appearance is reduced due to the gelation of the silicon-containing compound. Can be suppressed. There is no upper limit for 5/6 × N (0-60) / N (60-110), but if 5/6 × N (0-60) / N (60-110) exceeds 20, the sheet When this is stored for a long period of time, the silicon-containing compound tends to move into the sheet and the adhesiveness to glass tends to change. The area of the measurement target region 2c of N (60 to 110) is 5/6 times the area of the measurement target region 2a of N (0 to 60) and is 5/6 × N (0 to 60) / N. The value “5/6” in (60 to 110) is a coefficient for correcting the difference in area between the two regions.

  Further, 5/6 × N (0-60) / N (10-60) is 0.8-2, preferably 0.83-1.7, and 0.85-1.5. More preferably, it is 0.9 to 1.3. When 5/6 × N (0 to 60) / N (10 to 60) is less than 0.8, or exceeds 2, when the obtained sheet is stored for a long period of time, the adhesion to glass is increased. It may change and is not preferable. Note that the area of the measurement target region 2b of N (10 to 60) is 5/6 times the area of the measurement target region 2a of N (0 to 60), and is 5/6 × N (0 to 60) / N. The value “5/6” in (10-60) is a coefficient for correcting the difference in area between the two regions.

  W is an arbitrary positive number, and is preferably 10 to 1000 μm. In the present invention, when N (0-60), N (10-60) and N (60-110) are measured, TOF-SIMS measurement is performed with a uniform width W μm.

  The sheet of the present invention may contain an alkali metal salt and / or an alkaline earth metal salt from the viewpoint of optimizing the adhesiveness with glass, as long as it is not contrary to the gist of the present invention. The alkali metal salt and alkaline earth metal salt are not particularly limited, and a cation selected from alkali metal ions such as sodium ion and potassium ion, or alkaline earth metal ions such as magnesium ion and calcium ion, acetate ion and propane Acid ion, butanoic acid ion, 2-ethylhexylic acid ion, 2-ethyl-2-hexenoic acid ion, nonanoic acid ion, decanoic acid ion, stearic acid ion, oleic acid ion, carboxylate ion such as adipic acid ion, chlorine ion Conventionally known alkali metal salts and alkaline earth metal salts containing inorganic anions such as hydroxide ions are used. Among these, an alkali metal salt of a carboxylic acid or an alkaline earth metal salt of a carboxylic acid is particularly preferable from the viewpoint of appropriately adjusting the adhesiveness between the sheet of the present invention and glass. In particular, an alkali metal salt of a carboxylic acid having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, more preferably 2 to 3 carbon atoms, or 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, more preferably Alkaline earth metal salts of carboxylic acids having 2 to 3 carbon atoms are preferable from the viewpoint that the adhesiveness between the sheet and the glass hardly changes even when the sheet of the present invention is used for a long time. Especially, a C2-C3 alkaline earth metal salt is especially preferable at the point which is excellent in the inhibitory effect of the whitening at the time of water absorption.

  The content of the alkali metal salt and / or alkaline earth metal salt in the sheet of the present invention (when the alkali metal salt and alkaline earth metal salt are used in combination) is not particularly limited, but is 100 parts by weight of polyvinyl acetal. 0.001 to 0.1 parts by mass, more preferably 0.001 to 0.07 parts by mass, and even more preferably 0.001 to 0.05 parts by mass. When the content of the alkali metal salt and / or alkaline earth metal salt is less than 0.001 part by mass, the effect of adjusting the adhesiveness between the sheet of the present invention and the glass may not be sufficiently exhibited. When the content of the salt and / or alkaline earth metal salt exceeds 0.1 parts by mass, the sheet of the present invention is likely to be whitened by water absorption, which is not preferable.

  The sheet of the present invention may contain an antioxidant, an ultraviolet absorber, and other additives as long as it is not contrary to the gist of the present invention. For example, a conventionally known sheet can be used. The amount added can also be appropriately selected according to the purpose.

  Although the method for producing the sheet of the present invention is not particularly limited, for example, a method of laminating layers A and B having different concentrations of the silicon-containing compound may be mentioned. More preferably, the method of laminating | stacking in order of layer A / layer B / layer A is mentioned. In this case, both layer A and layer B contain polyvinyl acetal and a plasticizer having a molecular weight of 380 or more. The concentration of the silicon-containing compound contained in the layer A is preferably 1.2 times or more, more preferably 1.3 to 20 times the concentration of the silicon-containing compound contained in the layer B, and 1.4 10 to 10 times is more preferable, and 1.5 to 8 times is optimal. Furthermore, the thickness of the layer A is preferably 20 to 90 μm, more preferably 40 to 70 μm, still more preferably 55 to 70 μm, and most preferably 57 to 65 μm. The thickness of the layer B is preferably 50 to 1900 μm, more preferably 300 to 1200 μm, and further preferably 500 to 1000 μm. When layer A and layer B are stacked one on top of another, silicon in a region from 0 to 60 μm in the thickness direction from the sheet surface on the layer A side is compared to a region from 60 to 110 μm in the thickness direction from the sheet surface on the layer A side. The containing compound is distributed in a high concentration, and the silicon-containing compound has a region of 0 to 60 μm in the thickness direction from the sheet surface on the layer A side and a region of 10 to 60 μm in the thickness direction from the sheet surface on the layer A side. It is possible to obtain a sheet whose density does not change greatly, that is, a sheet defined in the present invention. When layer A / layer B / layer A are stacked in this order, the requirements specified in the present invention can be satisfied in any region specified from any surface.

  The content of the plasticizer having a molecular weight of 380 or more in the layer A is preferably 30 to 70 parts by mass, and more preferably 31 to 60 parts by mass with respect to 100 parts by mass of the polyvinyl acetal. Moreover, it is preferable that it is 0.002-0.3 mass part with respect to 100 mass parts of polyvinyl acetals, and, as for content of the silicon-containing compound in the layer A, it is 0.003-0.25 mass part. More preferred. When the content of the silicon-containing compound in the layer A is less than 0.002 parts by mass with respect to 100 parts by mass of the polyvinyl acetal, the adhesive strength with the glass cannot be adjusted appropriately, and the content of the silicon-containing compound in the layer A Is more than 0.3 parts by mass, when the obtained sheet is stored for a long period of time, the silicon-containing compound is transferred to the inside of the sheet, the adhesiveness with the glass is likely to change, the silicon-containing compound Gelation tends to impair the appearance.

  On the other hand, the content of the plasticizer having a molecular weight of 380 or more in the layer B is preferably 30 to 70 parts by mass and more preferably 31 to 60 parts by mass with respect to 100 parts by mass of the polyvinyl acetal. Moreover, it is preferable that it is 0.0001-0.02 mass part with respect to 100 mass parts of polyvinyl acetals, and, as for content of the silicon-containing compound in the layer B, it is 0.0005-0.01 mass part. More preferred. When the content of the silicon-containing compound in the layer B is less than 0.0001 parts by mass with respect to 100 parts by mass of the polyvinyl acetal, the silicon-containing compound moves into the sheet when the obtained sheet is stored for a long period of time. The adhesiveness to glass tends to change, and if it exceeds 0.02 parts by mass, the silicon-containing compound gels and the appearance tends to be impaired.

  Another method for producing the sheet of the present invention is a method in which layer D is formed on the surface of layer C containing polyvinyl acetal, a plasticizer and a silicon-containing compound by a casting method. In this case, the concentration of the silicon-containing compound contained in the layer D is preferably 1.2 times or more, more preferably 1.3 to 20 times the concentration of the silicon-containing compound contained in the layer C, More preferably, it is 1.4 to 10 times, and most preferably 1.5 to 8 times. The thickness of the layer C is preferably 50 to 1900 μm, preferably 300 to 1200 μm, and more preferably 500 to 1000 μm. The thickness of the layer D is preferably 20 to 90 μm, more preferably 40 to 70 μm, still more preferably 55 to 70 μm, and most preferably 57 to 65 μm. However, the concentration and thickness of the silicon-containing compound in layers C and D are not limited to these. Further, the layer D may be formed on one surface of the layer C, or the layer D may be formed on both surfaces of the layer C. By forming the layer D on one surface of the layer C, in the region of 0 to 60 μm in the thickness direction from the surface on the layer D side, compared to the region of 60 to 110 μm in the thickness direction from the surface on the layer D side. The silicon-containing compound is distributed at a high concentration, and the concentration of the silicon-containing compound in the region of 0 to 60 μm in the thickness direction from the surface on the layer D side and in the region of 10 to 60 μm in the thickness direction from the surface on the layer D side Can be obtained, that is, a sheet defined by the present invention. When the layer D is formed on both surfaces of the layer C, the requirements defined in the present invention can be satisfied in the region specified from any surface.

  The content of the plasticizer having a molecular weight of 380 or more in the layer C is preferably 30 to 70 parts by mass, and more preferably 31 to 60 parts by mass with respect to 100 parts by mass of the polyvinyl acetal. Further, the content of the silicon-containing compound in the layer C is preferably 0.0001 to 0.02 parts by mass and preferably 0.0005 to 0.01 parts by mass with respect to 100 parts by mass of the polyvinyl acetal. More preferred. When the content of the silicon-containing compound in the layer C is less than 0.0001 parts by mass with respect to 100 parts by mass of the polyvinyl acetal, the silicon-containing compound moves into the sheet when the obtained sheet is stored for a long period of time. The adhesiveness to glass tends to change, and if it exceeds 0.02 parts by mass, the silicon-containing compound gels and the appearance tends to be impaired.

  As a coating liquid used for forming the layer D, 30 to 70 parts by mass of a plasticizer having a molecular weight of 380 or more, 0.002 to 0.3 parts by mass of a silicon-containing compound and 1000 parts per 100 parts by mass of polyvinyl acetal. It is preferable to contain ~ 5000 parts by mass of a solvent. The content of the silicon-containing compound in the layer D is more preferably 0.005 to 0.25 parts by mass with respect to 100 parts by mass of the polyvinyl acetal. When the content of the silicon-containing compound in the layer D is more than 0.3 parts by mass with respect to 100 parts by mass of the polyvinyl acetal, the silicon-containing compound moves into the sheet when the resulting sheet is stored for a long period of time. As a result, the adhesiveness to glass tends to change, and the silicon-containing compound tends to gel and the appearance tends to be impaired. The solvent used in the coating solution for forming the layer D is not particularly limited as long as it can dissolve polyvinyl acetal, and examples thereof include tetrahydrofuran, chloroform, ethanol, propanol, butanol, and the like. Of these, ethanol and propanol are preferred. The coating solution for forming layer D is preferably applied so that the thickness of layer D when dried is 20 to 90 μm, more preferably 40 to 70 μm, and 55 It is more preferable to apply so as to be ˜70 μm.

  Whether the sheet of the present invention is a laminate of layer A and layer B or a laminate of layer C and layer D, the polyvinyl acetal, plasticizer, and silicon-containing compound are defined in the present invention. Needless to say, it meets the requirements. In the latter method, since the migration of the silicon-containing compound in the thickness direction of the sheet may occur due to the influence of the solvent used during casting, the sheet of the present invention is preferably produced by the former method. Further, even in the former method, when the layers A and B are laminated, if the temperature is heated to 120 ° C. or higher, the silicon-containing compound may move in the sheet thickness direction. It is preferable that the temperature be less than 120 ° C.

  In the sheet of the present invention, the difference between the viscosity average polymerization degree of the polyvinyl acetal contained in the portion of 0 to 60 μm from the surface of the sheet and the viscosity average polymerization degree of the polyvinyl acetal contained in the portion of 60 to 110 μm is 0 to 500. It is preferable that it is 0-300, It is more preferable that it is 0-200, It is optimal that it is 0-100. It is preferable that the difference in the viscosity average polymerization degree satisfies such a range because when the sheet of the present invention is stored for a long period of time, the silicon-containing compound does not easily move into the sheet.

  The difference between the degree of acetalization of the polyvinyl acetal contained in the layer A and the degree of acetalization of the polyvinyl acetal contained in the layer B is preferably 0 to 3 mol%, and preferably 0 to 2 mol%. More preferably, it is more preferably 0 to 1 mol%. Further, the difference between the average residual hydroxyl group content of polyvinyl acetal contained in layer A and the average residual hydroxyl group content of polyvinyl acetal contained in layer B is preferably 0 to 3 mol%, and 0 to 2 mol%. It is more preferable, and it is more preferable that it is 0-1 mol%. When the polyvinyl acetal contained in the sheet of the present invention satisfies such a range, when the sheet of the present invention is stored for a long period of time, it is difficult for the silicon-containing compound contained as an essential component to move into the sheet. Is preferred.

Further, in the plasticizer contained in the layer A used in making the sheets of the present invention, the highest content of high plasticizer and plasticizer A _1, also to more plasticizer Second plasticizer A _2, The content of plasticizer A ₁ with respect to 100 parts by mass of polyvinyl acetal in layer A is (a ₁ ) parts by mass, and the content of plasticizer A ₂ with respect to 100 parts by mass of polyvinyl acetal in layer A is (a ₂ ) parts by mass. Further, in the plasticizer contained in the layer B, most content-rich plasticizers and plasticizer B _1, also more plasticizers Secondly the plasticizer B _2, plasticizers for polyvinyl acetal 100 parts by weight of the layer B the content of B ₁ and _{(b 1)} part by weight, when the content of the plasticizer _{B 2} with respect to the polyvinyl acetal 100 parts by weight of the layer B and _{(b 2)} parts by weight, _(a 2) / Preferably a ₁₎ and _{(b 2) / (b 1} ) are both 0 to 0.1, more preferably from 0 to 0.07, more preferably from 0 to 0.05. Moreover, it is preferable that | [(a ₁ ) + (a ₂ )] − [(b ₁ ) + (b ₂ )] | ≦ 10, and | [(a ₁ ) + (a ₂ )] − [( b ₁ ) + (b ₂ )] | ≦ 7 is more preferable, and | [(a ₁ ) + (a ₂ )] − [(b ₁ ) + (b ₂ )] | ≦ 5 is satisfied. Further preferred. When (a ₁ ), (a ₂ ), (b ₁ ), and (b ₂ ) satisfy the above range, when the sheet of the present invention is stored for a long period of time, the silicon-containing compound in the thickness direction of the sheet This is preferable because the transition to the inside of the sheet hardly occurs.

  The thickness of the sheet of the present invention is 200 to 2000 μm (0.2 to 2 mm), preferably 500 to 1500 μm, and more preferably 700 to 1300 μm.

  Even if the sheet of the present invention is used as an interlayer film for laminated glass that has been stored for a long time at a relatively high moisture content, the adhesiveness to glass is the same as when using a sheet before long-term storage, Although it is suitable because it exhibits an appearance, in order to better exhibit the effects of the present invention, a temperature exceeding 30 ° C., preferably a temperature exceeding 25 ° C., more preferably a temperature exceeding 20 ° C. after the production of the sheet. Those stored at a low temperature such that the total storage time at is less than 3000 hours are more preferred. The storage time at a temperature exceeding 30 ° C. is preferably less than 2000 hours, and more preferably less than 1000 hours. When the storage time at a temperature exceeding 30 ° C. is 3000 hours or more, the silicon-containing compound contained as an essential component in the sheet of the present invention may migrate, and the intended characteristics of the present invention may not be exhibited.

  When the sheet of the present invention is used as an interlayer film for laminated glass, the glass laminated with the sheet is not particularly limited. In addition to inorganic glass such as float plate glass, polished plate glass, mold plate glass, mesh plate glass, heat ray absorbing plate glass, Conventionally known organic glasses such as methyl methacrylate and polycarbonate can be used, and these may be colorless, colored, transparent or non-transparent, but inorganic glass is more preferable. These may be used alone or in combination of two or more. The thickness of the glass is not particularly limited, but is preferably 20 mm or less, more preferably 10 mm or less, and even more preferably 5 mm or less. Further, a part or all of the organic glass or inorganic glass used in the laminated glass may be replaced with a polyester sheet or the like.

  When using the sheet | seat of this invention as an intermediate film for laminated glasses, the shape of the outermost surface of a sheet | seat is not specifically limited, A smooth thing and what provided the uneven structure may be used.

  When using the sheet of the present invention as an interlayer film for laminated glass, the method for producing laminated glass is not particularly limited, and can be produced by a conventionally known method. For example, a method using a vacuum laminator device, a vacuum Examples include a method using a bag, a method using a vacuum ring, a method using a nip roll, and the like. Moreover, you may process the obtained temporary bonded body by an autoclave after temporary bonding by these methods.

In the case of using a vacuum laminator device, an example of the production conditions is shown. Lamination is performed at a temperature of 100 to 200 ° C., preferably 130 to 160 ° C. under a reduced pressure of 1 × 10 ^{−6 to} 3 × 10 ⁻² MPa. A method using a vacuum bag or a vacuum ring is described in, for example, European Patent No. 1235683, and is laminated at 130 to 145 ° C. under a pressure of about 2 × 10 ⁻² MPa, for example.

  In the case of using a nip roll, an example of the operating condition is as follows: a method of first press-bonding at a temperature not higher than the flow start temperature of polyvinyl acetal plasticized with a plasticizer, and then temporarily pressing at a temperature close to the flow start temperature Is mentioned. Specifically, for example, after heating to 30 to 70 ° C. with an infrared heater or the like, degassing with a roll, and further heating to 50 to 120 ° C., followed by pressure bonding with a roll and bonding or temporary bonding can be mentioned.

  The operating conditions of the autoclave process that is additionally performed after the temporary pressure bonding are appropriately selected according to the thickness and configuration of the module and the laminated glass. For example, the operating conditions are 130 to 130 at a pressure of 1.0 to 1.5 MPa (gauge pressure). The treatment is carried out at a temperature of ˜145 ° C. for 0.5 to 3 hours.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Preparation of PVB-1)
In a 5 L (liter) glass container equipped with a reflux condenser, thermometer, and squid type stirring blade, 3690 g of ion exchange water, polyvinyl alcohol (PVA-1) (viscosity average polymerization degree 1700, saponification degree 99.0 mol%) ) 310 g was charged and the temperature was raised while heating the solution to completely dissolve the polyvinyl alcohol. Next, after cooling the solution to 8 ° C. in about 30 minutes, 180 g of butyraldehyde and 158 g of 20% hydrochloric acid were added, and a butyralization reaction was performed for 60 minutes. Thereafter, the reaction solution was heated to 66 ° C., held at 66 ° C. for 100 minutes, and then cooled to room temperature. After washing the polyvinyl acetal resin with ion-exchanged water, the acid catalyst was neutralized with an aqueous sodium hydroxide solution, further washed with ion-exchanged water, dehydrated and dried to obtain polyvinyl butyral (PVB-1). The resulting PVB-1 had a butyralization degree (average acetalization degree) of 70.1 mol%, a residual vinyl acetate group content of 0.9 mol%, and an average residual hydroxyl group content of 29 mol%. . The degree of butyralization of PVB-1 and the content of the remaining vinyl acetate groups were measured according to JIS K6728. The measurement results are shown in Table 1.

(Preparation of PVB-2)
Polyvinyl butyral (PVB-2) was obtained in the same manner as in the preparation of PVB-1, except that the amount of butyraldehyde used was changed to 195 g and the holding time at 66 ° C. was changed to 190 minutes. PVB-2 had a butyralization degree (average acetalization degree) of 74.5 mol%, a residual vinyl acetate group content of 0.9 mol%, and an average residual hydroxyl group amount of 24.6 mol%. The degree of butyralization of PVB-2 and the content of residual vinyl acetate groups were measured according to JIS K6728. The measurement results are shown in Table 1.

(Preparation of PVB-3)
Polyvinyl butyral (PVB-3) was obtained in the same manner as in the preparation of PVB-1, except that the amount of butyraldehyde used was changed to 175 g and the holding time at 66 ° C. was changed to 90 minutes. The degree of butyralization (average degree of acetalization) of PVB-3 was 68.0 mol%, the content of residual vinyl acetate groups was 0.9 mol%, and the average amount of residual hydroxyl groups was 31.1 mol%. The degree of butyralization of PVB-3 and the content of residual vinyl acetate groups were measured according to JIS K6728. The measurement results are shown in Table 1.

Example 1
100 parts by mass of PVB-1, 39 parts by mass of triethylene glycol di-2-ethylhexanoate, 0.03 parts by mass of magnesium acetate tetrahydrate, BHT (3,5-t-butyl-4-hydroxytoluene) 0.1 part by mass, 0.03 part by mass of benzotriazole-based ultraviolet absorber (manufactured by BASF, TINUVIN 328), 0.02 part by mass of 3-glycidyloxypropyltrimethoxysilane was melt-kneaded at 150 ° C. Composition-1A was obtained. Further, Composition-1B was obtained in the same manner as Composition-1A, except that the amount of 3-glycidyloxypropyltrimethoxysilane added was 0.005 parts by mass. A layer-1A having a thickness of 60 μm is prepared as the sheet A by hot pressing the composition-1A at 150 ° C., and a layer having a thickness of 680 μm is formed as the sheet B by hot pressing the composition-1B at 150 ° C. -1B was prepared, and these were stacked in the order of layer-1A / layer-1B / layer-1A, and hot-pressed at 100 ° C. and a pressure of 40 kg / cm ² for 5 minutes to obtain a sheet 1 having a thickness of 800 μm. Got. The silicon contained in Sheet-1 was measured by ICP emission analysis and found to be 5.2 ppm. In addition, the ICP emission analysis of the amount of silicon was performed by adding a sulfuric acid and nitric acid to PVB-1 sample and thermally decomposing it, and then using a solution with a constant volume of hydrochloric acid and using an ICP emission analyzer (Optima 4300 DV manufactured by Perkin Elmer). This was done by measuring (hereinafter the same). The results are shown in Table 3.

(Measurement and analysis of time-of-flight secondary ion mass spectrometry (TOF-SIMS))
The obtained sheet-1 was cut using a microtome in a direction parallel to the thickness direction of the cross section. Using TOF-SIMS5 manufactured by ION-TOF Co., and using a scanning mode using a Bi ₃ ⁺⁺ ion gun as a primary ion source, a cross section in the thickness direction of the obtained sheet-1 is 0 in the thickness direction from the surface. An area of ˜128 μm and width of 128 μm was divided into vertical and horizontal 128 × 128 = 16384 pixels (that is, the total number of pixels measured was 16384 pixels), and analysis was performed on each pixel. From the obtained data, the total number N (0 to 60) of silicon secondary ions detected from a region of 0 to 60 μm in the thickness direction and a width of 128 μm, detected from a region of 10 to 60 μm in the thickness direction and a width of 128 μm The total number of silicon secondary ions N (10 to 60) and the total number N (60 to 110) of silicon secondary ions detected from a region having a thickness of 60 to 110 μm and a width of 128 μm are obtained. 5/6 × N (0-60) / N (60-110) and 5/6 × N (0-60) / N (10-60) were determined. The results are shown in Table 3.

(Heat conditioning, storage and evaluation of sheets)
Sheet-1 was stored at 23 ° C. and 50% RH. After 0 hours from the start of storage (that is, before storage immediately after obtaining a sheet by hot pressing), after 300 hours, after 500 hours, and after 3000 hours, the sheet-1 is adhered to glass by the method described later. And the transparency was evaluated.

(Evaluation of adhesion to glass)
Sheet-1 was conditioned at 23 ° C. and 28% RH for 24 hours to adjust the moisture content to 0.5%. Subsequently, the float glass having a thickness of 2 mm is laminated so as to be float glass / sheet-1 / float glass, put into a vacuum bag, treated at 100 ° C. and −0.09 MPa (gauge pressure), and temporarily bonded, The laminated glass 1-1 was obtained by processing at 140 ° C. and 1.2 MPa (gauge pressure) in an autoclave. The laminated glass 1-1 was allowed to stand at a temperature of −18 ° C. for 24 hours, and then smashed with a hammer having a head weight of 0.45 kg until the particle diameter of the glass became 6 mm or less. The glass piece peeled off from the intermediate film (sheet-1) was shaken off, and the Pummel value was determined according to the criteria shown in Table 2 based on the exposure degree (%) of the intermediate film. It shows that the adhesiveness with respect to the glass plate of a plasticization film is so high that a Pummel value is large. Here, the degree of exposure is the ratio of the area of the portion where the glass piece is peeled and the intermediate film is exposed to the entire area of the intermediate film. The results are shown in Table 4.

(Evaluation of transparency)
Sheet-1 was conditioned at 23 ° C. and 28% RH for 24 hours to adjust the moisture content to 0.5%. Subsequently, the float glass having a thickness of 2 mm is laminated so as to be float glass / sheet-1 / float glass, put into a vacuum bag, treated at 100 ° C. and −0.09 MPa (gauge pressure), and temporarily bonded, Laminated glass 1-2 was obtained by processing at 140 ° C. and 1.2 MPa (gauge pressure) in an autoclave. The state of the obtained laminated glass 1-2 was visually confirmed under an illuminance of 500 lux. Moreover, the light of 2000 candela was irradiated to the laminated glass 1-2 from the distance of 30 cm, and the mode was confirmed visually. A case where no foreign matter was found in both cases was designated as A, a case where foreign matter was seen only when 2000 candela light was irradiated, and a case where foreign matter was seen in both cases was designated as C. The results are shown in Table 4.

(Examples 2-29)
Sheets 2 to -29 were produced in the same manner as in Example 1 except that the compositions shown in Table 3 were changed, and the same evaluation as in Example 1 was performed. The results are shown in Tables 3 and 4.

(Comparative Examples 1, 2, and 11)
The A layer changed to the composition shown in Table 5 was prepared in the same manner as in Example 1, and these were used as Comparative Example Sheet-1, Comparative Example Sheet-2, and Comparative Example Sheet-11, respectively, as in Example 1. The method was evaluated. The results are shown in Tables 5 and 6.

(Comparative Examples 8 and 9)
A layer changed to the composition shown in Table 5 was prepared in the same manner as in Example 1, and in both cases, a 1% tetrahydrofuran (THF) solution of 3-glycidyloxypropyltriethoxysilane in Comparative Example 8 was used. Using a bar coater, it was applied at a thickness of 50 μm. In Comparative Example 9, a 0.1% THF solution of 3-glycidyloxypropyltriethoxysilane was applied at a thickness of 50 μm using a bar coater. THF was naturally dried, and the obtained sheets were referred to as Comparative Example Sheet-8 and Comparative Example Sheet-9, respectively. These were evaluated in the same manner as in Example 1. The results are shown in Tables 5 and 6.

(Comparative Examples 3 to 7 and 10)
Comparative Example Sheets 3 to 7 and Comparative Example Sheet-10 were respectively produced in the same manner as Example 1 except that the compositions shown in Table 5 were changed, and the same evaluation as in Example 1 was performed. The results are shown in Tables 5 and 6.

1 Sheet 2 Measurement area

Claims (16)

The sheet contains a polyvinyl acetal, a plasticizer having a molecular weight of 380 or more, and a silicon-containing compound. The plasticizer having a molecular weight of 380 or more is 30 to 70 parts by weight with respect to 100 parts by weight of the polyvinyl acetal, and the sheet has a thickness of 0.2 to 2 mm. When the sheet is analyzed by ICP emission spectrometry, 0.10 to 30 ppm of silicon is detected,
When TOF-SIMS measurement is performed in a cross section parallel to the thickness direction of the sheet, the total number of silicon secondary ions detected from a region of 0 to 60 μm in the thickness direction and a width of W μm from at least one surface of the sheet N (0 to 60), 10 to 60 μm in the thickness direction from the surface, and the total number of silicon secondary ions detected from the region of width W μm to N (10 to 60), from the surface in the thickness direction When the total number of silicon secondary ions detected from the region of 60 to 110 μm and width W μm is N (60 to 110), 5/6 × N (0 to 60) / N (60 to 110) is 1. 2 or more, and 5/6 × N (0-60) / N (10-60) is 0.8-2. The sheet according to claim 1, comprising an alkali metal salt and / or an alkaline earth metal salt. The sheet according to claim 2, wherein the alkali metal salt and / or alkaline earth metal salt is an alkali metal salt of carboxylic acid or an alkaline earth metal salt of carboxylic acid. The sheet according to claim 3, wherein the carboxylic acid is a carboxylic acid having 1 to 8 carbon atoms. The sheet according to any one of claims 2 to 4, wherein the content of the alkali metal salt and / or alkaline earth metal salt is 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the polyvinyl acetal. The sheet according to any one of claims 1 to 5, wherein the silicon-containing compound is a compound containing a silicon-oxygen bond. The sheet according to any one of claims 1 to 6, wherein the silicon-containing compound is a silane coupling agent. The sheet according to any one of claims 1 to 6, wherein the silicon-containing compound is silicone oil. The sheet according to any one of claims 1 to 8, wherein the plasticizer having a molecular weight of 380 or more is triethylene glycol di-2-ethylhexanoate. The sheet according to any one of claims 1 to 9, wherein, after producing the sheet, the total storage time at a temperature exceeding 30 ° C is less than 3000 hours. The viscosity average polymerization degree of polyvinyl acetal existing in a region of 0 to 60 μm in the thickness direction from the surface of the sheet, and the viscosity average polymerization degree of polyvinyl acetal existing in a region of 60 to 110 μm in the thickness direction from the surface. The sheet according to any one of claims 1 to 10, wherein the difference is 0 to 500. It is obtained by laminating a layer A containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound, and a layer B containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound,
The concentration of the silicon-containing compound contained in layer A is higher than the concentration of the silicon-containing compound contained in layer B,
The sheet according to any one of claims 1 to 11, wherein the difference between the degree of acetalization of the polyvinyl acetal contained in the layer A and the degree of acetalization of the polyvinyl acetal contained in the layer B is 0 to 3 mol%. It is obtained by laminating a layer A containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound, and a layer B containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound,
The concentration of the silicon-containing compound contained in layer A is higher than the concentration of the silicon-containing compound contained in layer B,
The sheet according to any one of claims 1 to 12, wherein the difference between the average residual hydroxyl group content of polyvinyl acetal contained in layer A and the average residual hydroxyl group content of polyvinyl acetal contained in layer B is 0 to 3 mol%. It is obtained by laminating a layer A containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound, and a layer B containing polyvinyl acetal, a plasticizer having a molecular weight of 380 or more and a silicon-containing compound,
The concentration of the silicon-containing compound contained in layer A is higher than the concentration of the silicon-containing compound contained in layer B,
The most common plasticizer content of the plasticizer contained in the layer A and a plasticizer A _1, more plasticizers second content and plasticizer A _2, relative to 100 parts by mass of the polyvinyl acetal contained in the layer A The content of the plasticizer A ₁ is (a ₁ ) parts by mass, the content of the plasticizer A ₂ with respect to 100 parts by mass of the polyvinyl acetal is (a ₂ ) parts by mass, and among the plasticizers contained in the layer B The plasticizer B ₁ having the largest content is designated as plasticizer B ₁ , the plasticizer B ₂ having the second largest content is designated as plasticizer B _2, and the content of plasticizer B ₁ relative to 100 parts by mass of polyvinyl acetal contained in layer B is b ₁ ) parts by mass, and when the content of the plasticizer B ₂ with respect to 100 parts by mass of the polyvinyl acetal is (b ₂ ) parts by mass,
(A ₂ ) / (a ₁ ) and (b ₂ ) / (b ₁ ) are 0 to 0.1,
The sheet according to claim 1, wherein | [(a1) + (a2)] − [(b1) + (b2)] | ≦ 10. The sheet contains a polyvinyl acetal, a plasticizer having a molecular weight of 380 or more, and a silicon-containing compound. The plasticizer having a molecular weight of 380 or more is 30 to 70 parts by weight with respect to 100 parts by weight of the polyvinyl acetal, and the sheet has a thickness of 0.2 to 2 mm. When the sheet is analyzed by ICP emission spectrometry, 0.10 to 30 ppm of silicon is detected,
When TOF-SIMS measurement is performed in a cross section parallel to the thickness direction of the sheet, the total number of silicon secondary ions detected from the region of 0 to X μm and width W μm in the thickness direction from at least one surface of the sheet N (0 to X), and the total number of silicon secondary ions detected from the region of X / 6 to X μm and width W μm in the thickness direction from the surface is N (X / 6 to X). When the total number of silicon secondary ions detected from the region of X to 11X / 6 μm and width W μm in the thickness direction is N (X to 11X / 6), 5/6 × N (0 to X) / N (X to 11X / 6) is 1.2 or more, 5/6 × N (0 to X) / N (X / 6 to X) is 0.8 to 2, and X is 20 to 90 μm. There is a sheet. Laminated glass comprising the sheet according to claim 1.

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