JP2011213523A - Method for producing interlayer for laminated glass, interlayer for laminated glass, and the laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an interlayer for laminated glass, with which an interlayer for laminated glass on which unevenness in the appearance is suppressed and a pattern is hardly visually recognized when light passes therethrough, can be obtained.SOLUTION: The method for producing the interlayer 1 for the laminated glass, in which a first layer 2 and a second layer 3 are laminated, includes: a step in which inorganic particles 5 are dispersed in a plasticizer to obtain a dispersion and the obtained dispersion is mixed with a thermoplastic resin to prepare a second layer-forming composition containing the thermoplastic resin, plasticizer and inorganic particles 5; and a coextrusion step of coextruding a first layer-forming composition containing a thermoplastic resin and the second layer-forming composition containing the thermoplastic resin, plasticizer and inorganic particles 5 to thereby obtain the objective interlayer 1 for laminated glass in which the first layer 2 and the second layer 3 are laminated.

Description

  The present invention relates to a method for producing an interlayer film for laminated glass in which a layer containing inorganic particles and a layer different from the layer containing inorganic particles are co-extruded, and a laminate obtained by the method for producing an interlayer film for laminated glass The present invention relates to an interlayer film for glass and a laminated glass provided with the interlayer film for laminated glass.

  Laminated glass is widely used in automobiles, railway vehicles, aircraft, ships, buildings, and the like. As the laminated glass, there is a colored laminated glass. Colored laminated glass is used in applications requiring privacy protection, such as daylighting windows, bathroom doors, and veranda waistboards.

  The colored laminated glass is manufactured, for example, by sandwiching a colored intermediate film between a pair of transparent glass plates.

  As an example of the colored intermediate film, Patent Document 1 below proposes a colored intermediate film in which opacifying agents such as calcium carbonate or silica are dispersed in a thermoplastic resin. This colored intermediate film is produced by dispersing an opacifier in a thermoplastic resin and then molding it.

Japanese Examined Patent Publication No. 2-56295

  Since the colored intermediate film described in Patent Document 1 is colored with an opacifier, the light transmission amount of the colored laminated glass using the colored intermediate film can be relatively reduced. Furthermore, when the person or object is viewed through the colored laminated glass, the visibility of the person or object can be lowered.

  By the way, a multilayer interlayer film having a laminated structure of two or more layers is known as an interlayer film used for the laminated glass. If the colored intermediate film described in Patent Document 1 is laminated with another intermediate film, uneven appearance may occur when light is transmitted through the obtained multilayer intermediate film or a laminated glass using the multilayer intermediate film. It is easy to occur and a pattern may be visually recognized.

  An object of the present invention is to provide a method for producing an interlayer film for laminated glass capable of obtaining an interlayer film for laminated glass in which unevenness in appearance is suppressed when light is transmitted and the pattern is hardly visually recognized, and for the laminated glass It is to provide an interlayer film for laminated glass obtained by the method for producing an interlayer film, and a laminated glass provided with the interlayer film for laminated glass.

  According to a wide aspect of the present invention, there is provided a method for producing an interlayer film for laminated glass in which a first layer and a second layer are laminated, wherein a dispersion is obtained by dispersing inorganic particles in a plasticizer. Thereafter, the step of mixing the obtained dispersion and the thermoplastic resin to prepare a second layer forming composition containing the thermoplastic resin, the plasticizer, and the inorganic particles, and the first containing the thermoplastic resin The first layer and the second layer are laminated by coextrusion of the layer forming composition and the second layer forming composition containing a thermoplastic resin, a plasticizer, and inorganic particles. And a coextrusion step for obtaining an interlayer film for laminated glass.

  In a specific aspect of the method for producing an interlayer film for laminated glass according to the present invention, when producing the interlayer film for laminated glass in which the first layer, the second layer, and the third layer are laminated, After dispersing the inorganic particles in the agent to obtain a dispersion, the obtained dispersion and thermoplastic resin are mixed, and the second layer-forming composition containing the thermoplastic resin, the plasticizer, and the inorganic particles A first layer forming composition containing a thermoplastic resin, the second layer forming composition containing a thermoplastic resin, a plasticizer and inorganic particles, and a first resin containing a thermoplastic resin. A coextrusion step of coextruding the layer forming composition 3 to obtain an interlayer film for laminated glass in which the first layer, the second layer, and the third layer are laminated in this order; Is provided.

  In another specific aspect of the method for producing an interlayer film for laminated glass according to the present invention, calcium carbonate is used as the inorganic particles.

  The interlayer film for laminated glass according to the present invention is an interlayer film for laminated glass obtained by the method for producing an interlayer film for laminated glass.

  The laminated glass according to the present invention includes an interlayer film for laminated glass configured according to the present invention and first and second laminated glass constituent members, and the interlayer film for laminated glass includes the first and second interlayer films. It is sandwiched between laminated glass components.

  In the method for producing an interlayer film for laminated glass according to the present invention, inorganic particles are dispersed in a plasticizer to obtain a dispersion, and then the second obtained by mixing the dispersion and a thermoplastic resin. Since the layer forming composition is used, the second layer forming composition and the first layer forming composition or the first and third layer forming compositions are further coextruded. Unevenness of the appearance is suppressed, and an interlayer film for laminated glass in which a pattern is difficult to be visually recognized when light is transmitted can be obtained.

FIG. 1 is a partially cutaway sectional view showing an interlayer film for laminated glass obtained by the method for manufacturing an interlayer film for laminated glass according to one embodiment of the present invention. FIG. 2 is a partially cutaway sectional view showing an example of laminated glass using the interlayer film for laminated glass shown in FIG.

  Details of the present invention will be described below.

(Interlayer film for laminated glass)
FIG. 1 shows a partially cutaway sectional view of an interlayer film for laminated glass obtained by the method for producing an interlayer film for laminated glass according to one embodiment of the present invention.

  The intermediate film 1 shown in FIG. 1 includes a first layer 2, a second layer 3 laminated on the surface 2 a of the first layer 2, and a first layer 2 of the second layer 3. And a third layer 4 laminated on the other surface 3b opposite to the one surface 3a. The intermediate film 1 is used to obtain a laminated glass. The intermediate film 1 is an intermediate film for laminated glass.

  The second layer 3 includes a thermoplastic resin, a plasticizer, and a plurality of inorganic particles 5. The intermediate film 1 does not include the second layer 3 containing inorganic particles on both surfaces.

  Since the second layer 3 includes the inorganic particles 5, it is generally a colored layer. The second layer 3 is preferably colored, and is preferably a colored layer. The second layer 3 is more preferably milky white and more preferably a milky white layer. The first and third layers 2 and 4 contain a thermoplastic resin. Each of the first and third layers 2 and 4 is preferably transparent, and is preferably a transparent layer.

  The intermediate film 1 has a three-layer structure in which a first layer 2, a second layer 3 containing inorganic particles, and a third layer 4 are laminated in this order. Thus, the second layer 3 containing the inorganic particles 5 is preferably sandwiched between the first and third layers 2 and 4. In this case, the laminated glass constituent member can be firmly bonded to both surfaces of the intermediate film 1. However, the third layer 4 is not necessarily used. That is, the first layer 2 may be laminated only on one surface 3 a of the second layer 3 including the inorganic particles 5. In this case, another layer is not laminated on the other surface 3b of the second layer 3, and a layer containing inorganic particles is not laminated. The other surface 3b of the second layer 3 is a layer on which laminated glass constituent members are laminated. Further, the intermediate film may have a laminated structure of four layers or more.

  The thickness of the intermediate film is not particularly limited. The thickness of the intermediate film indicates the total thickness of each layer constituting the intermediate film. Therefore, in the case of the intermediate film 1, the thickness of the intermediate film 1 indicates the total thickness of the first to third layers 2 to 4. From the viewpoint of practical use, and from the viewpoint of sufficiently improving penetration resistance and weather resistance, the thickness of the intermediate film is preferably in the range of 0.1 to 3 mm. A more preferable lower limit of the thickness of the intermediate film is 0.25 mm, and a more preferable upper limit is 1.5 mm. If the thickness of the intermediate film is too thin, the penetration resistance or weather resistance of the laminated glass may be lowered.

(Method for producing interlayer film for laminated glass)
In the method for producing an interlayer film for laminated glass according to this embodiment for obtaining the interlayer film 1, first, inorganic particles 5 are dispersed in a plasticizer in order to obtain a second layer forming composition. To obtain a dispersion liquid dispersed in a plasticizer. Next, the obtained dispersion liquid and the thermoplastic resin are mixed, and a second layer forming composition containing the thermoplastic resin, the plasticizer, and the inorganic particles 5 is prepared.

  That is, in the present embodiment, in order to prepare the second layer forming composition and produce the second layer 3, the inorganic particles 5 are not added to the thermoplastic resin in a state where they are not dispersed in the plasticizer. Further, the thermoplastic resin, the plasticizer, and the inorganic particles 5 are added at a time and are not mixed.

  Furthermore, a first layer forming composition containing a thermoplastic resin and a third layer forming composition containing a thermoplastic resin are prepared.

  Next, a first layer forming composition containing a thermoplastic resin, a second layer forming composition containing a thermoplastic resin, a plasticizer, and inorganic particles 5, and a third layer containing a thermoplastic resin The forming composition is laminated by coextrusion. Thus, the first layer 2 formed by the first layer forming composition, the second layer 3 including the inorganic particles 5 formed by the second layer forming composition, The intermediate film 1 in which the third layer 4 formed by the third layer forming composition is laminated is obtained.

  In addition, when obtaining the intermediate film which is not provided with the 3rd layer 4, the said 2nd containing the said 1st layer forming composition containing a thermoplastic resin, a thermoplastic resin, a plasticizer, and an inorganic particle. The layer forming composition is coextruded. In this way, the first layer formed of the first layer forming composition and the second layer 3 containing inorganic particles formed of the second layer forming composition are in this order. A laminated interlayer film for laminated glass is obtained.

  The main feature of the method for producing an interlayer film for laminated glass according to the present embodiment is that the inorganic particles 5 are dispersed in a plasticizer, and then the dispersion and the thermoplastic resin are mixed. By using the second layer forming composition thus mixed, the inorganic particles 5 can be uniformly dispersed in the second layer 3. For this reason, it becomes difficult for the inorganic particles 5 to be partially concentrated at the bonding interface between the second layer 3 and the first and third layers 2 and 4. Further, during the co-extrusion, partial variations are less likely to occur in the melt viscosity of the second layer forming composition containing the inorganic particles 5 in the extruder. For this reason, the adhesion interface between the second layer 3 and the first and third layers 2 and 4 can be made uniform. For example, it is difficult for a rough region to be partially formed at the bonding interface between the second layer 3 and the first and third layers 2 and 4.

  Furthermore, another main feature of the method for producing an interlayer film for laminated glass according to the present embodiment is that the first to third layer forming compositions are coextruded. By coextrusion of the first to third layer forming compositions, the uniformity of the adhesion interface between the second layer 3 and the first and third layers 2 and 4 can be enhanced. Further, when only the first and second layer forming compositions are coextruded without using the third layer forming composition, the first layer 2 and the second layer 3 The uniformity of the bonding interface can be improved.

  Therefore, when light passes through the intermediate film 1 obtained as described above and the laminated glass using the intermediate film 1, unevenness in appearance can be suppressed and it is difficult to visually recognize the pattern.

  On the other hand, in the interlayer film for laminated glass in which the layer containing the conventional inorganic particles is laminated on a layer different from the layer containing the inorganic particles, the adhesion interface between the layer containing the inorganic particles and the other layer. In, for example, many irregularities are likely to be present on the surface of each layer. For this reason, when light passes through the intermediate film or the laminated glass, the light is scattered due to the unevenness, the appearance unevenness is likely to occur, and the pattern may be visually recognized.

(Details of materials of first to third layer forming compositions)
The second layer 3 and the second layer forming composition include a thermoplastic resin, a plasticizer, and inorganic particles 5. Each of the first and third layers 2 and 4 and the first and third layer-forming compositions contains a thermoplastic resin. More preferably, the first and third layers 2 and 4 and the first and third layer forming compositions each include a thermoplastic resin and a plasticizer.

  The thermoplastic resin is not particularly limited. Examples of the thermoplastic resin include polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic copolymer resin, polyurethane resin, sulfur-containing polyurethane resin, and polyvinyl alcohol resin. Of these, polyvinyl acetal resin is preferably used. As for the said thermoplastic resin, only 1 type may be used and 2 or more types may be used together. Further, the thermoplastic resins used in the first to third layer forming compositions may be the same or different.

  The polyvinyl acetal resin is a resin obtained by acetalizing a polyvinyl alcohol resin (PVA) with an aldehyde. As said polyvinyl acetal resin, the polyvinyl acetal resin generally used for the intermediate film for laminated glasses can be used. Examples of the polyvinyl acetal resin include a polyvinyl formal resin obtained by reacting a polyvinyl alcohol resin and formaldehyde, a narrowly defined polyvinyl acetal resin obtained by reacting a polyvinyl alcohol resin and acetaldehyde, and a polyvinyl alcohol resin and n-butyraldehyde. And polyvinyl butyral resin obtained by the reaction.

  The polyvinyl acetal resin is preferably a resin obtained by acetalizing a polyvinyl alcohol resin with an aldehyde having 1 to 10 carbon atoms. The more preferable lower limit of the carbon number of the aldehyde is 4, and the more preferable upper limit is 6. The vinyl acetate component (residual acetyl group) of the polyvinyl acetal resin is preferably 30 mol% or less.

  The manufacturing method of the said polyvinyl acetal resin is not specifically limited. The said polyvinyl acetal resin can be manufactured with a conventionally well-known manufacturing method.

  The second layer forming composition contains a plasticizer. Each of the first and third layer forming compositions preferably contains a plasticizer. In particular, when the thermoplastic resin is a polyvinyl acetal resin, a plasticizer is preferably included. By the combined use of the polyvinyl acetal resin and the plasticizer, the adhesive force between the interlayers of the interlayer film and the adhesive force between the interlayer film and the laminated glass constituent member can be further increased.

  As the plasticizer, known plasticizers generally used for interlayer films can be used. Examples of the plasticizer include triethylene glycol-di-2-ethylbutyrate (3GH), triethylene glycol-di-2-ethylhexanoate (3GO), and triethylene glycol-di-n-heptanoate (3G7). , Tetraethylene glycol-di-2-ethylhexanoate (4GO), tetraethylene glycol-di-n-heptanoate (4G7) or oligoethylene glycol-di-2-ethylhexanoate (NGO) is preferably used. .

  Examples of the plasticizer include phthalic acid esters such as ricinoleic acid alkyl ester, dioctyl phthalate (DOP), dibutyl phthalate (DBP) and diisodecyl phthalate (DIDP), di-2-ethylhexyl adipate (DOA) and diisodecyl adipate ( Adipic acid esters such as DIDA), sebacic acid esters such as dibutyl sebacate (DBS) and di-2-ethylhexyl sebacate (DOS), phosphate esters such as tricresyl phosphate (TCP) and trioctyl phosphate (TOP), In addition, epoxidized soybean oil or the like may be used. As for the said plasticizer, only 1 type may be used and 2 or more types may be used together. The plasticizers used in the first to third layer forming compositions may be the same or different.

  The plasticizer content of the first to third layer forming compositions is preferably in the range of 25 to 70 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The minimum with more preferable content of the said plasticizer with respect to 100 weight part of the said thermoplastic resins is 30 weight part, and a more preferable upper limit is 60 weight part. When the content of the plasticizer is within the above range, the penetration resistance of the interlayer film can be further enhanced, and the adhesion between the interlayer film and the laminated glass constituent member can be further enhanced.

  The content of the plasticizer with respect to 100 parts by weight of the thermoplastic resin in the second layer forming composition is the plasticizer with respect to 100 parts by weight of the thermoplastic resin in the first and third layer forming compositions. The content is preferably larger than the content of 5 parts by weight, more preferably 5 parts by weight or more, still more preferably 10 parts by weight or more.

  As the inorganic particles 5 contained in the second layer forming composition, calcium carbonate, alumina, kaolin clay, calcium silicate, magnesium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, talc, feldspar powder, Examples include mica, barite, barium carbonate, titanium oxide, silica, and glass beads. As for the said inorganic particle, only 1 type may be used and 2 or more types may be used together.

  The inorganic particles 5 are preferably at least one of calcium carbonate, titanium oxide, and silica, and more preferably calcium carbonate. By using these preferable inorganic particles, it is possible to obtain an intermediate film in which unevenness in appearance is less likely to occur when light is transmitted and the pattern is more difficult to be visually recognized.

  The average particle diameter of the inorganic particles 5 is preferably in the range of 1 to 100 μm, and more preferably in the range of 1 to 50 μm. The average particle diameter can be measured by a dynamic light scattering method using an Ar laser as a light source, using a light scattering measuring device. Examples of the light scattering measurement device include “DLS-6000AL” manufactured by Otsuka Electronics Co., Ltd.

  The content of the inorganic particles 5 in the second layer forming composition is preferably in the range of 0.3 to 30 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The minimum with more preferable content of the inorganic particle 5 with respect to 100 weight part of said thermoplastic resins is 0.5 weight part, and a more preferable upper limit is 20 weight part. When the content of the inorganic particles 5 is within the above range, an appropriately colored intermediate film can be obtained. Further, when light is transmitted, the appearance unevenness is more difficult to occur, and the pattern is more difficult to be visually recognized.

  The first and third layer forming compositions preferably do not contain inorganic particles. When inorganic particles are not included, since there are no inorganic particles on the surfaces of the first and third layers 2 and 4, a laminated glass constituent member is further formed on the surfaces of the first and third layers 2 and 4. It can be firmly bonded. However, the first and third layer forming compositions may contain a small amount of inorganic particles. In this case, the content of the inorganic particles with respect to 100 parts by weight of the thermoplastic resin in the first and third layer forming compositions is 100 parts by weight of the thermoplastic resin in the second layer forming composition. It is preferable that the content is smaller than the content of inorganic particles. Furthermore, the content of the inorganic particles in the first and third layer forming compositions is preferably 30 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin. There exists a tendency for the adhesive force of a 1st, 3rd layer and a laminated glass structural member to fall, so that there is much content of an inorganic particle.

  The first to third layer forming compositions include heat ray shielding particles, light shielding agents, colorants, ultraviolet absorbers, antioxidants, adhesive strength modifiers, light stabilizers, flame retardants, antistatic agents, and moisture resistance. Known additives used for interlayer films for laminated glass, such as an agent, a heat ray reflective agent and a heat ray absorber, can be added.

  Examples of the heat ray shielding particles include tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), indium-doped zinc oxide (IZO), tin-doped zinc oxide, silicon-doped zinc oxide, and antimony. Examples include zinc acid, lanthanum hexaboride, cerium hexaboride, gold powder, silver powder, platinum powder, and aluminum powder.

  Examples of the light-shielding agent include carbon black and red iron oxide.

  Examples of the colorant include pigments and dyes. The colorant is preferably a pigment. As the pigment, a black pigment carbon black, a red pigment (CI Pigment red), a blue pigment (CI Pigment blue), and a yellow pigment (CI Pigment yellow) were mixed. Examples include dark reddish brown mixed pigments.

  Examples of the ultraviolet absorber include malonic acid ester compounds, oxalic acid anilide compounds, benzotriazole compounds, benzophenone compounds, triazine compounds, benzoate compounds, hindered amine compounds, and the like. Of these, benzotriazole compounds are preferred.

  Examples of the antioxidant include t-butylhydroxytoluene, tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, and the like.

  Examples of the adhesive strength modifier include alkali metal salts of organic and inorganic acids, alkaline earth metal salts of organic and inorganic acids, silane coupling agents, and modified silicone oils.

(Laminated glass)
The interlayer film for laminated glass according to the present invention is used for obtaining laminated glass.

  FIG. 2 shows an example of a laminated glass using the intermediate film 1 shown in FIG.

  A laminated glass 11 shown in FIG. 2 includes an intermediate film 1 and first and second laminated glass constituting members 12 and 13. The intermediate film 1 is an intermediate film for laminated glass. The intermediate film 1 is sandwiched between the first and second laminated glass constituent members 12 and 13. Therefore, the laminated glass 11 is configured by laminating the first laminated glass constituting member 12, the intermediate film 1, and the second laminated glass constituting member 13 in this order. The first laminated glass constituent member 12 is laminated on the surface of the first layer 2. The second laminated glass constituting member 13 is laminated on the surface of the third layer 4.

  Examples of the first and second laminated glass constituent members 12 and 13 include glass plates and PET (polyethylene terephthalate) films. The laminated glass 11 includes not only a laminated glass in which an interlayer film for laminated glass is sandwiched between two glass plates, but also a laminated glass in which an interlayer film for laminated glass is sandwiched between a glass plate and a PET film or the like. included. The laminated glass 11 is a glass plate-containing laminate, and it is sufficient that at least one glass plate is used. Further, another laminated glass constituent member may be laminated on the outer surface of at least one of the first and second laminated glass constituent members 12 and 13. The another laminated glass constituent member may be a glass plate.

  Examples of the glass plate include inorganic glass and organic glass. Examples of the inorganic glass include float plate glass, heat ray absorbing plate glass, polished plate glass, mold plate glass, mesh plate glass, and wire plate glass. The organic glass is a synthetic resin glass substituted for inorganic glass. Examples of the organic glass include polycarbonate plates and poly (meth) acrylic resin plates. Examples of the poly (meth) acrylic resin plate include a polymethyl (meth) acrylate plate.

  Although the thickness of the laminated glass component members 12 and 13 is not specifically limited, It is preferable to exist in the range of 1-5 mm. Moreover, when the laminated glass structural members 12 and 13 are glass plates, it is preferable that the thickness of this glass plate exists in the range of 1-5 mm. When the laminated glass constituent members 12 and 13 are PET films, the thickness of the PET film is preferably in the range of 0.03 to 0.5 mm.

  The manufacturing method of the laminated glass 11 is not specifically limited. For example, the intermediate film 1 is sandwiched between the first and second laminated glass constituent members 12 and 13 and passed through a pressing roll, or put in a rubber bag and sucked under reduced pressure, so that the first and second The air remaining between the laminated glass constituent members 12 and 13 and the intermediate film 1 is deaerated. Then, it pre-adheres at about 70-110 degreeC, and a laminated body is obtained. Next, the laminated body is put in an autoclave or pressed, and pressed at about 120 to 150 ° C. and a pressure of 1 to 1.5 MPa. In this way, the laminated glass 11 can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited only to the following examples.

(Synthesis Example 1)
Synthesis of polyvinyl butyral resin (a):
191 parts by weight of polyvinyl alcohol having an average degree of polymerization of 1700 and a degree of saponification of 88.1 mol% was added to 2890 parts by weight of pure water, heated and dissolved to obtain a solution. The temperature of this solution was adjusted to 12 ° C., and 201 parts by weight of 35% by weight hydrochloric acid catalyst and 148 parts by weight of n-butyraldehyde were added to the above solution and kept at 12 ° C. to precipitate the reaction product. Then, it hold | maintained at 45 degreeC for 3 hours, and reaction was completed. Next, it was washed with excess water, unreacted n-butyraldehyde was washed away, and the hydrochloric acid catalyst was neutralized with an aqueous sodium hydroxide solution. After washing with excess water for 2 hours, it was dried to obtain a white powdery polyvinyl butyral resin (a).

  The average degree of butyralization of the obtained polyvinyl butyral resin (a) was 63.8 mol%, and the vinyl acetate component was 11.9 mol%.

(Synthesis Example 2)
Synthesis of polyvinyl butyral resin (b):
191 parts by weight of polyvinyl alcohol having an average degree of polymerization of 1700 and a saponification degree of 98.9 mol% was added to 2890 parts by weight of pure water, heated and dissolved to obtain a solution. The temperature of this solution was adjusted to 12 ° C., and 201 parts by weight of 35% by weight hydrochloric acid catalyst and 152 parts by weight of n-butyraldehyde were added to the above solution and maintained at 12 ° C. to precipitate the reaction product. Then, it hold | maintained at 45 degreeC for 3 hours, and reaction was completed. Next, it was washed with excess water, unreacted n-butyraldehyde was washed away, and the hydrochloric acid catalyst was neutralized with an aqueous sodium hydroxide solution. After washing with excess water for 2 hours, it was dried to obtain a white powdery polyvinyl butyral resin (b).

  The average degree of butyralization of the obtained polyvinyl butyral resin (b) was 68.0 mol%, and the vinyl acetate component was 1.1 mol%.

Example 1
Preparation of composition A:
60 parts by weight of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer and 5 parts by weight of calcium carbonate as inorganic particles (“Super # 1500” manufactured by Maruo Calcium Co., Ltd., average particle size 2.2 μm) To obtain a dispersion liquid in which inorganic particles are dispersed in a plasticizer.

  65 parts by weight of the obtained dispersion and 100 parts by weight of the polyvinyl butyral resin (a) were mixed to obtain a composition A.

Preparation of composition B:
100 parts by weight of the polyvinyl butyral resin (b) and 40 parts by weight of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer were mixed to obtain a composition B.

Preparation of interlayer film for laminated glass:
The obtained composition A was used as the second layer forming composition. Further, the obtained composition B was used as the first and third layer forming compositions.

  Using a multilayer extruder, the composition B as the first layer forming composition, the composition A as the second layer forming composition, and the above as the third layer forming composition Composition B was coextruded. In this way, the first layer (transparent layer, thickness 0.33 mm) formed of the composition B, and the second layer (milky white layer, thickness 0.10 mm) formed of the composition A, Then, an interlayer film for laminated glass was obtained in which the third layer (transparent layer, thickness 0.33 mm) formed of the composition B was laminated in this order.

Laminated glass production:
The obtained interlayer film for laminated glass was cut into a size of 30 cm in length and 30 cm in width.

  The obtained intermediate film was sandwiched between two glass plates (length 30 cm × width 30 cm × thickness 2.5 mm) to obtain a laminate. Next, the obtained laminate was put in a rubber bag and deaerated for 20 minutes at a vacuum degree of 2.6 kPa. While being deaerated, the laminate was vacuum pressed while being kept in an oven at 90 ° C. for 30 minutes. The laminated glass preliminarily pressure-bonded in this manner was pressure-bonded for 20 minutes at 135 ° C. and a pressure of 1.2 MPa in an air autoclave to obtain a laminated glass.

(Example 2)
Preparation of composition C:
In preparing the composition A of Example 1, the inorganic particles were converted from calcium carbonate ("Super # 1500" manufactured by Maruo Calcium Co., Ltd., average particle size 2.2 [mu] m) to silica ("SO-C6" manufactured by Admatechs), A composition C was obtained in the same manner except that the average particle size was changed to 2.2 μm.

Preparation of interlayer film for laminated glass and laminated glass:
An interlayer film for laminated glass and a laminated glass were produced in the same manner as in Example 1, except that the composition C obtained instead of the composition A was used as the second layer forming composition.

(Example 3)
Preparation of composition D:
A composition D was obtained in the same manner except that the content of the inorganic particles was changed from 5 parts by weight to 3 parts by weight during the preparation of the composition A of Example 1.

Preparation of interlayer film for laminated glass and laminated glass:
An interlayer film for laminated glass and a laminated glass were produced in the same manner as in Example 1 except that the composition D obtained instead of the composition A was used as the second layer forming composition.

Example 4
Preparation of composition E:
Composition E was obtained in the same manner except that the content of the inorganic particles was changed from 5 parts by weight to 10 parts by weight when preparing the composition A of Example 1.

Preparation of interlayer film for laminated glass and laminated glass:
An interlayer film for laminated glass and a laminated glass were produced in the same manner as in Example 1 except that the composition E obtained instead of the composition A was used as the second layer forming composition.

(Comparative Example 1)
Preparation of composition F:
100 parts by weight of the polyvinyl butyral resin (a), 60 parts by weight of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer, and calcium carbonate (“Super # 1500” manufactured by Maruo Calcium Co., Ltd.) as inorganic particles. And 5 parts by weight of an average particle size of 2.2 μm) were mixed at once (powder addition) to obtain a composition F.

Preparation of interlayer film for laminated glass and laminated glass:
An interlayer film for laminated glass and a laminated glass were produced in the same manner as in Example 1 except that the composition F obtained instead of the composition A was used as the second layer forming composition.

(Comparative Example 2)
Laminated glass production:
The composition A obtained in Example 1 was used as the second layer forming composition. The composition A was sufficiently melt-kneaded with a mixing roll and then press-molded at 150 ° C. for 30 minutes using a press molding machine to produce a second layer (milky white layer, thickness 0.1 mm).

  The composition B obtained in Example 1 was used as the first and third layer forming compositions. The composition B was sufficiently melt-kneaded with a mixing roll, and then press-molded at 150 ° C. for 30 minutes using a press molding machine, and the first layer (transparent layer, thickness 0.33 mm) and the third layer (transparent layer) , And a thickness of 0.33 mm).

  The obtained first to third layers were each cut into a size of 30 cm in length and 30 cm in width.

  Between the two glass plates (length 30 cm × width 30 cm × thickness 2.5 mm), the obtained first layer, the obtained second layer, and the obtained third layer are arranged in this order. Were stacked and sandwiched to obtain a laminate. Next, the obtained laminate was put in a rubber bag and deaerated for 20 minutes at a vacuum degree of 2.6 kPa. While being deaerated, the laminate was vacuum-pressed while being kept in an oven at 90 ° C. for 30 minutes. The laminated glass preliminarily pressure-bonded in this manner was pressure-bonded for 20 minutes in an air autoclave under conditions of 135 ° C. and a pressure of 1.2 MPa to obtain a laminated glass provided with an interlayer film for laminated glass.

(Evaluation)
A fluorescent lamp was placed at a position 200 cm away from the eyes. The direction of connecting the center of the fluorescent lamp and the eye so that the center of the laminated glass is positioned on the line connecting the center of the fluorescent lamp and the eye at a position 60 cm away from the eye, and the thickness of the laminated glass Laminated glass was placed so that the direction was parallel.

  The appearance of the laminated glass when the light from the fluorescent light was transmitted through the laminated glass was evaluated according to the following evaluation criteria.

[Evaluation criteria for appearance]
○: Uneven appearance is not observed and no pattern is observed ×: Uneven appearance is observed and the pattern is visible

  The blending components of Compositions A to F and the blending method of the inorganic particles are shown in Table 1 below. The evaluation results are shown in Table 2 below.

DESCRIPTION OF SYMBOLS 1 ... Intermediate film for laminated glass 2 ... 1st layer 2a ... Surface 3 ... 2nd layer 3a ... One surface 3b ... Other surface 4 ... 3rd layer 5 ... Inorganic particle 11 ... Laminated glass 12 ... 1st Laminated glass constituent member 13 ... Second laminated glass constituent member

Claims (5)

A method for producing an interlayer film for laminated glass in which a first layer and a second layer are laminated,
After dispersing inorganic particles in a plasticizer to obtain a dispersion, the obtained dispersion and thermoplastic resin are mixed, and a second layer forming composition containing the thermoplastic resin, the plasticizer, and inorganic particles Preparing a product,
Coextruding the first layer-forming composition containing a thermoplastic resin, and the second layer-forming composition containing a thermoplastic resin, a plasticizer, and inorganic particles, the first layer and the The manufacturing method of the intermediate film for laminated glasses provided with the coextrusion process of obtaining the intermediate film for laminated glass laminated | stacked with the 2nd layer. A method for producing an interlayer film for laminated glass in which a first layer, a second layer, and a third layer are laminated in this order,
After dispersing inorganic particles in a plasticizer to obtain a dispersion, the obtained dispersion and thermoplastic resin are mixed, and a second layer forming composition containing the thermoplastic resin, the plasticizer, and inorganic particles Preparing a product,
A first layer-forming composition containing a thermoplastic resin, a second layer-forming composition containing a thermoplastic resin, a plasticizer and inorganic particles, and a third layer-forming composition containing a thermoplastic resin A co-extrusion step of coextruding a product to obtain an interlayer film for laminated glass in which the first layer, the second layer, and the third layer are laminated in this order. The manufacturing method of the intermediate film for laminated glasses as described in any one of.   The method for producing an interlayer film for laminated glass according to claim 1, wherein calcium carbonate is used as the inorganic particles.   The intermediate film for laminated glasses obtained by the manufacturing method of the intermediate film for laminated glasses of any one of Claims 1-3. An interlayer film for laminated glass according to claim 4,
First and second laminated glass components,
Laminated glass in which the interlayer film for laminated glass is sandwiched between the first and second laminated glass constituting members.

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