JP5177364B2 - Method for producing interlayer film for laminated glass - Google Patents

Description

The present invention relates to an interlayer film for laminated glass used for laminated glass including film tempered glass and the like excellent in impact resistance, penetration resistance, crime prevention, etc. used in automobiles, railway vehicles, buildings, showcases, etc. about the how to manufacture.

  Generally, laminated glass having a structure in which a transparent adhesive layer (intermediate film) is sandwiched between glass plates is used for glass used for automobiles, particularly windshields. The transparent adhesive layer is formed of, for example, a PVB film, an EVA film, or the like, and the presence of the transparent adhesive layer improves the penetration resistance of the laminated glass. In addition, broken glass fragments remain attached to the transparent adhesive layer in response to an impact from the outside, thus preventing scattering. For this reason, for example, even if a laminated glass of an automobile is broken for the purpose of theft or intrusion, the window cannot be opened freely, so that it is useful as a security glass. Such a laminated glass is described in Patent Document 1, for example.

  On the other hand, for example, automobile door glass and fitted glass are generally less likely to be destroyed in an accident, and therefore do not require the penetration resistance or the like of the windshield, so a slightly reinforced low-strength glass. A board is used. However, when only such a single glass plate is used, there are the following drawbacks. That is, (1) Inferior to laminated glass in terms of impact resistance, penetration resistance, etc. (2) If broken for the purpose of theft or intrusion, it breaks into many pieces and the window is opened freely And so on. For this reason, it is also considered to use glass having characteristics such as laminated glass for the door glass and the fitted glass. As glass suitable for such applications, film tempered glass in which a glass plate and a plastic film are bonded via a transparent adhesive layer is described in Patent Documents 2 and 3, for example.

  Such an interlayer film (transparent adhesive layer) that bonds the two glass plates of laminated glass or the glass plate of the film tempered glass and the plastic film has excellent adhesion and penetration resistance as described above. It has been demanded. In particular, high performance is required for laminated glass using two glass plates. Furthermore, recently, high sound insulation is also required to block noise outside the vehicle.

  However, a laminated glass using a PVB film as an interlayer film for laminated glass has good penetration resistance and impact resistance. However, since moisture resistance is not sufficient, transparency and adhesiveness may deteriorate due to long-term use. is there.

  On the other hand, a laminated glass using an EVA film can obtain good sound insulation and excellent water resistance, adhesion and penetration resistance, but the transparency may not be sufficient.

  In Patent Document 4 (Japanese Patent Application Laid-Open No. 2004-50750), since it has excellent moisture resistance, transparency and adhesiveness can be maintained over a long period of time, and sound insulation, penetration resistance, and impact resistance are remarkably high. As a good glass laminate or the like, a first adhesive resin layer mainly composed of polyvinyl butyral resin and a second adhesive resin layer mainly composed of ethylene-vinyl acetate copolymer resin are provided between the substrates. A glass laminate having a layer structure or a three-layer structure has been proposed.

  When producing a composite film having a two-layer or three-layer structure including such a PVB layer and an EVA layer, for example, each layer is cut into a predetermined size, aligned, and laminated and pressure-bonded. In this case, the dimensional accuracy and positioning at the time of cutting are complicated, and the productivity is low.

JP 2002-187746 A JP 2002-046217 A JP 2002-068785 A JP 2004-50750 A

  As a method for producing a composite film having a two-layer or three-layer structure including a PVB layer and an EVA layer, it is considered that a multilayer extrusion method using a generally known die can be used. However, according to the study of the present inventor, for example, an EVA layer / PVB layer / EVA layer having a structure excellent in transparency, adhesiveness, sound insulation, penetration resistance and impact resistance is melted and extruded by a die. In this case, it is necessary to set the melting temperature to about 200 ° C. at which PVB can be melted. When the organic peroxide (crosslinking agent) is contained in EVA at such a high temperature, a crosslinking reaction of EVA occurs, It has been found that there is a problem of thickening and, in some cases, gelation.

  An object of this invention is to provide the method of manufacturing simply the intermediate film for laminated glasses of the 3 layer structure of EVA layer / PVB layer / EVA layer.

  In addition, the present invention provides a method for easily producing an interlayer film for laminated glass having a three-layer structure of EVA layer / PVB layer / EVA layer excellent in transparency, adhesion, sound insulation, penetration resistance, and impact resistance. The purpose is to do.

  This inventor repeated examination about the method which can manufacture the intermediate film for laminated glasses of a 3 layer structure of EVA layer / PVB layer / EVA layer easily, and between the EVA layers in the softened state or the molten state which heated only the PVB layer As a result of the insertion, it was found that three layers can be pressure-bonded while preventing the crosslinking reaction of the EVA layer, and the present invention has been achieved.

The above purpose is
Production of an interlayer film for laminated glass comprising a step of pressing and laminating two EVA sheets of a resin composition containing an ethylene / vinyl acetate copolymer and an organic peroxide through a PVB sheet of a resin composition containing polyvinyl butyral In the method
In the above step, a resin composition containing polyvinyl butyral is heated and extruded into a sheet shape, and the obtained softened PVB sheet is inserted between two EVA sheets, thereby producing an interlayer film for laminated glass An intermediate for laminated glass comprising a step of pressing and laminating two EVA sheets of a resin composition containing an ethylene / vinyl acetate copolymer and an organic peroxide through a PVB sheet of a resin composition containing polyvinyl butyral In the method for producing a membrane,
In the above process, the resin composition containing polyvinyl butyral is heated and extruded from a T-die into a sheet shape, and the obtained softened PVB sheet is inserted between two EVA sheets conveyed between a pair of rolls. A method for producing an interlayer film for laminated glass,
Is achieved.

The suitable aspect of the manufacturing method of the intermediate film for laminated glasses of this invention is as follows.
(1) The heat extrusion temperature of the resin composition containing polyvinyl butyral is in the range of 150 to 250 ° C, particularly in the range of 180 to 220 ° C. Suitable for melting polyvinyl butyral.
(2) The temperature of the two EVA sheets is in the range of 0 to 50 ° C, particularly in the range of 10 to 40 ° C. The PVB sheet and the EVA sheet can be favorably bonded.
(3) The temperature of the T die is in the range of 150 to 250 ° C, particularly in the range of 180 to 220 ° C. Suitable for melting polyvinyl butyral.
(4) The temperature of the roll is in the range of -20 to 40 ° C, particularly in the range of 0 to 30 ° C. The softened state of the PVB sheet can be controlled so that the pressure bonding with the EVA sheet can be performed satisfactorily.
(5) The roll is an embossing roll or a guide roll. An embossing roll is particularly preferable. Embossing is possible at the same time.
(6) The extruded PVB sheet is inserted between the two EVA sheets within 5 seconds after the extrusion, further within 3 seconds, particularly within 1 to 3 seconds. The softened state of the PVB sheet can be controlled so that the pressure bonding with the EVA sheet can be performed satisfactorily.
(7) The thickness of each EVA layer is in the range of 0.1 to 1.0 mm. If the upper limit is exceeded, the thickness of the intermediate film is too large, the resulting laminate is bulky, and the transparency is also unfavorable. On the other hand, in the case of less than the lower limit, the contribution of the properties of the EVA layer (eg, high viscoelasticity at low temperature, moisture resistance, sound insulation) is not sufficient. The thickness of the EVA layer is particularly preferably in the range of 0.1 to 0.5 mm. Further, from the above viewpoint, it is preferable that the thickness of the total EVA layer is in the range of 0.1 to 1.0 mm.
(8) The thickness of each PVB layer is in the range of 0.1 to 2.0 mm. If the upper limit is exceeded, the thickness of the intermediate film is too large, the resulting laminate is bulky, and the transparency is also unfavorable. On the other hand, if it is less than the lower limit, the contribution of PVB characteristics (eg, high viscoelasticity at room temperature) is not sufficient. The thickness of the PVB layer is particularly preferably in the range of 0.1 to 1.0 mm.
(9) The vinyl acetate unit of the ethylene / vinyl acetate copolymer is in the range of 23 to 38% by mass with respect to 100 parts by mass of the ethylene vinyl acetate copolymer. Excellent transparency.
(10) The ethylene / vinyl acetate copolymer has an organic peroxide of 0.05 to 4.0 parts by mass (particularly 0.05 to 1.0 part by mass with respect to 100 parts by mass of the ethylene / vinyl acetate copolymer). Part).

  In the method for producing an interlayer film for laminated glass according to the present invention, a resin composition containing polyvinyl butyral is heated and extruded into a sheet shape, and the PVB sheet is softened or melted (high temperature state) in two organic oxide-containing EVA sheets. By inserting between the layers, the EVA layer and the PVB layer can be pressure-bonded by utilizing the latent heat of the high-temperature PVB sheet while preventing the crosslinking reaction of the EVA layer. Therefore, an interlayer film for laminated glass having a three-layer structure of EVA layer / PVB layer / EVA layer can be produced very easily.

  Moreover, since the obtained interlayer film for laminated glass has a three-layer structure of EVA layer / PVB layer / EVA layer as described above, transparency, adhesion, sound insulation, penetration resistance, and impact resistance are thereby obtained. As well as good performance, excellent penetration resistance and impact resistance can be obtained even under harsh conditions (low temperature or severe impact), so laminated glass with improved penetration resistance and impact resistance can be used. It can be said that it is a suitable intermediate film.

  The method for producing an interlayer film for laminated glass of the present invention is a method by which an interlayer film for laminated glass having a three-layer structure of EVA layer / PVB layer / EVA layer can be produced very easily.

  The method for producing an interlayer film for laminated glass of the present invention will be described in detail below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an example of an embodiment of the manufacturing method of the present invention.

  The PVB resin composition melt-mixed from the extruder 1 is supplied to the heated T die 2, and the molten PVB resin composition is extruded from the T die 2 into a sheet shape. The extruded softened PVB sheet 3 is inserted between the EVA sheets 4A and 4B conveyed to the pair of rolls 5A and 5B near the normal temperature, and is crimped by the pair of rolls 5A and 5B. A laminated intermediate film 6 made of the PVB sheet 3 / EVA sheet 4B is obtained. The intermediate film 6 is sent to the cooling roll 7 by the auxiliary roll 7, and the cooled intermediate film 6 is taken up via the auxiliary roll 9. The interlayer film for laminated glass of the obtained laminate is heat-crosslinked at the time of producing laminated glass.

  The EVA sheets 4A and 4B are generally produced by extrusion molding, calendar molding, or the like at a temperature at which crosslinking does not occur (generally around 100 ° C.), but are cooled until reaching the rolls 5A and 5B. Alternatively, EVA sheets 4A and 4B that have already been prepared separately may be used.

  The temperature of the heated T die 2 to which the PVB resin composition is sent is preferably in the range of 150 to 250 ° C, particularly in the range of 180 to 220 ° C. That is, in the T die 2, the PVB resin composition is heated so as to have sufficient fluidity. The extruded PVB sheet is also in the range of 150 to 250 ° C, particularly in the range of 180 to 220 ° C. The PVB sheet immediately after being extruded is in a softened state close to a molten state.

  The extruded softened PVB sheet is inserted between the two EVA sheets conveyed to the rolls 5A and 5B as soon as possible. That is, since the high-temperature softened PVB sheet and the two EVA sheets are pressure-bonded on the rolls 5A and 5B, a temperature (latent heat) at which these three layers can be fused and integrated with sufficient adhesive strength. ) Must have a PVB sheet. For this reason, it is generally preferable that the PVB sheet extruded by heating is inserted between the two EVA sheets within 5 seconds after the extrusion, further within 3 seconds, particularly 1 to 3 seconds.

  In this case, the temperature of the two EVA sheets is generally around room temperature as described above, and is preferably in the range of 0 to 50 ° C., particularly in the range of 10 to 40 ° C. In this case, it is preferable to set the temperature of the rolls 5A and 5B in the range of -20 to 40 ° C, particularly in the range of 0 to 30 ° C, in order to set the temperature of the EVA sheet. Thereby, crimping | bonding of a PVB sheet and an EVA sheet | seat can be performed favorably with the stable dimension.

  Examples of the T die include a T-type manifold die, a fish tail die, a coat hanger die, and a screw die. A T-type manifold die is preferred.

  The rolls 5A and 5B are generally embossed rolls or guide rolls. An embossing roll is particularly preferable. As a result, embossing is possible simultaneously with crimping. The embossing rolls may be both embossing rolls, one being an embossing roll and the other being a rubber roll or the like.

  The thickness of the EVA sheet (EVA layer) is preferably in the range of 0.1 to 1.0 mm, particularly preferably in the range of 0.1 to 0.5 mm. If the upper limit is exceeded, the thickness of the intermediate film is too large, the resulting laminate is bulky, and the transparency is also unfavorable. On the other hand, in the case of less than the lower limit, the contribution of the properties of the EVA layer (eg, high viscoelasticity at low temperature, moisture resistance, sound insulation) is not sufficient. From such a viewpoint, it is particularly preferable that the total thickness of the two EVA layers is in the range of 0.1 to 1.0 mm.

  The thickness of the PVB sheet (PVB layer) is preferably in the range of 0.1 to 2.0 mm, particularly preferably in the range of 0.1 to 1.0 mm. If the upper limit is exceeded, the thickness of the intermediate film is too large, the resulting laminate is bulky, and the transparency is also unfavorable. On the other hand, if it is less than the lower limit, the contribution of PVB characteristics (eg, high viscoelasticity at room temperature) is not sufficient.

Since the production method of the present invention is characterized by inserting a softened PVB sheet between two EVA sheets, any method may be used as long as such processing is possible. For example, the PVB sheet may be inserted by being softened with a heating roll.

  The interlayer film for laminated glass obtained by the above manufacturing method has a basic structure as shown in FIG.

  FIG. 2 is a cross-sectional view showing an example of an embodiment of the interlayer film of the present invention. The intermediate film 22 is a three-layer laminated film in which an EVA layer 23A, a PVB layer 24, and an EVA layer 23B are laminated in this order.

  The production method of the present invention usually provides the above three-layer laminated film. For example, this three-layer laminated film is used instead of one EVA layer (EVA sheet) in the production method of the present invention. Thus, a five-layer laminated film can be obtained.

  FIG. 3 is a cross-sectional view showing an example of a preferred embodiment of the laminated glass of the present invention. The laminated glass 30 of FIG. 3 is obtained by bonding and integrating two glass plates 31A and 31B with an intermediate film 32. The EVA layers 33A and 33B are in contact with both the glass plate 31A and the glass plate 31B, respectively. Since both of the glass plates 31A and 31B are in contact with the EVA layers 33A and 33B, the adhesion and water resistance between the glass plates 31A and 31B and the intermediate film 32 are greatly improved, and the glass scatters when the laminated glass is broken. Is greatly suppressed and durability is also improved. In the intermediate film of the three-layer laminated film, the thickness of the PVB layer and the EVA layer are preferably set as described above, whereby the obtained laminated body has transparency, adhesiveness, sound insulation, Not only has good penetrability and impact resistance, but also excellent penetration resistance and impact resistance under severe conditions (low temperature or severe impact).

  In FIG. 3, one of the glass plates may be a transparent plastic film. In that case, it may be called film tempered glass. Alternatively, both of the glass plates may be transparent plastic films.

  The laminated glass of the present invention can be designed to have appropriate performance in terms of impact resistance, penetration resistance, transparency, etc. when one of the glass plates is plastic film (film reinforced glass). For example, it can be used for glass such as window glass provided in various vehicle bodies and buildings, or glass such as showcases and show windows. Both glass plates can be designed to exhibit particularly excellent impact resistance and improved penetration resistance, and can be used for various applications including laminated glass.

  The glass plate used in the present invention is usually silicate glass. In the case of film tempered glass, the glass plate thickness varies depending on the place where it is installed. For example, when it is used for a side glass and a fitted glass of an automobile, it is not necessary to make it thick like a windshield, generally 0.1 to 10 mm, and preferably 0.3 to 5 mm. The one glass plate 1 is reinforced chemically or thermally.

  In the case of a laminated glass that is both a glass plate suitable for an automobile windshield or the like, the thickness of the glass plate is generally 0.5 to 10 mm, and preferably 1 to 8 mm.

  The interlayer film for laminated glass of the present invention is a film having at least one EVA layer and PVB layer as described above.

  The PVB resin composition constituting the PVB sheet generally contains a PVB resin, a plasticizer, an ultraviolet absorber, and the like. As the PVB resin, those having a vinyl acetal unit (mainly vinyl butyral unit) of 70 to 95% by weight, a vinyl acetate unit of 1 to 15% by weight and an average degree of polymerization of 200 to 3000, particularly 300 to 2500 are preferred.

  Examples of the plasticizer for the PVB resin composition include organic plasticizers such as monobasic acid esters and polybasic acid esters, and phosphoric acid plasticizers.

  Monobasic acid esters include organic acids such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptanoic acid, n-octylic acid, 2-ethylhexylic acid, pelargonic acid (n-nonylic acid), decylic acid, and tris. Esters obtained by reaction with ethylene glycol are preferred, in particular triethylene-di-2-ethylbutyrate, triethylene glycol-di-2-ethylhexoate, triethylene glycol-di-capronate, triethylene glycol- Di-n-octoate is preferred. An ester of the above organic acid with tetraethylene glycol or tripropylene glycol can also be used.

  As the polybasic acid ester plasticizer, for example, an ester of an organic acid such as adipic acid, sebacic acid or azelaic acid and a linear or branched alcohol having 4 to 8 carbon atoms is preferable, and in particular, dibutyl seba Kate, dioctyl azelate and dibutyl carbitol adipate are preferred.

  As the phosphoric acid plasticizer, tributoxyethyl phosphate, isodecylphenyl phosphate, triisopropyl phosphate and the like are preferable.

  In the PVB resin composition, if the amount of the plasticizer is small, the film formability is deteriorated, and if it is too large, the durability during heat resistance is impaired. Therefore, the plasticizer is generally added in an amount of 5 to 50 with respect to 100 parts by mass of the polyvinyl butyral resin. It is preferable to include 10 parts by mass, particularly 10 to 40 parts by mass.

  In the PVB resin composition of the present invention, a benzophenone compound, a triazine compound, a benzoate compound, a hindered amine compound, or the like can be used as an ultraviolet absorber (UV absorber). Benzophenone compounds are preferred because yellowing is suppressed.

  Preferred examples of the benzophenone compounds include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-n-octylbenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, particularly 2-hydroxy-4-n-octylbenzophenone, 2,2'-dihydroxy- 4,4′-dimethoxybenzophenone is preferred.

  In a PVB layer, it is preferable to use the said ultraviolet absorber 0.05-1.0 mass part (especially 0.1-0.2 mass part) with respect to 100 mass parts of PVB.

  Furthermore, the PVB resin composition may contain an alkali or alkaline earth metal salt of a fatty acid (generally used as an adhesion modifier).

  Examples of alkaline earth metal salts of the fatty acids include magnesium formate, magnesium acetate, magnesium lactate, magnesium stearate, magnesium octylate, calcium formate, calcium acetate, calcium lactate, calcium stearate, calcium octylate, barium formate, acetic acid Barium, barium lactate, barium stearate, barium octylate, etc .; examples of alkali metal salts of fatty acids include potassium formate, potassium acetate, potassium lactate, potassium stearate, potassium octylate, sodium formate, sodium acetate, sodium lactate , Sodium stearate, sodium octylate and the like.

  Additives such as stabilizers and antioxidants may be added to the PVB resin composition to further prevent deterioration.

  EVA used in the EVA resin composition constituting the EVA sheet (layer) has a vinyl acetate content of generally 23 to 38% by mass, more preferably 23 to 38% by mass, and particularly 23 to 28% by mass. Is preferred. When the vinyl acetate content is less than 23% by mass, the transparency of the resin obtained when crosslinked and cured at a high temperature is not sufficient. Conversely, when the vinyl acetate content exceeds 38% by mass, the impact resistance when a security glass is obtained. The penetration resistance tends to be insufficient. Moreover, it is preferable that the melt flow index (MFR) of EVA is 4.0-30.0 g / 10min, especially 8.0-18.0g / 10min. Pre-crimping becomes easy.

  The EVA resin composition contains an organic peroxide and an ultraviolet absorber in the EVA, and may further contain various additives such as a crosslinking aid, an adhesion improver, and a plasticizer as necessary. it can.

  Examples of the ultraviolet absorber include benzophenone compounds, triazine compounds, benzoate compounds, and hindered amine compounds. From the viewpoint of suppressing yellowing, benzophenone compounds are preferred.

  In the EVA layer, it is preferable to use 0.05 to 1.0 parts by mass (particularly 0.1 to 0.2 parts by mass) of the ultraviolet absorber with respect to 100 parts by mass of EVA.

  In the present invention, any organic peroxide can be used in combination as long as it decomposes at a temperature of 100 ° C. or higher to generate radicals. The organic peroxide is generally selected in consideration of the film formation temperature, the adjustment conditions of the composition, the curing (bonding) temperature, the heat resistance of the adherend, and the storage stability. In particular, those having a decomposition temperature of 70 hours or more with a half-life of 10 hours are preferred.

  Examples of this organic peroxide include 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane-3-di- t-butyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, dicumyl peroxide, α, α′-bis (t-butylperoxy) Isopropyl) benzene, n-butyl-4,4-bis (t-butylperoxy) valerate, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -3 , 3,5-trimethylcyclohexane, t-butyl peroxybenzoate, benzoyl peroxide, t-butyl peroxyacetate, methyl ethyl ketone pero Oxide, 2,5-dimethylhexyl-2,5-bisperoxybenzoate, butyl hydroperoxide, p-menthane hydroperoxide, p-chlorobenzoyl peroxide, hydroxyheptyl peroxide, chlorohexanone peroxide, octanoyl peroxide Oxide, decanoyl peroxide, lauroyl peroxide, cumyl peroxy octoate, succinic acid peroxide, acetyl peroxide, m-toluoyl peroxide, t-butyl peroxyisobutylene and 2,4-dichlorobenzoyl peroxide Can be mentioned.

  The EVA layer is used to improve or adjust various physical properties of the film (optical properties such as mechanical strength, adhesiveness, transparency, heat resistance, light resistance, crosslinking speed, etc.), and in particular to improve mechanical strength. It preferably contains a group-containing compound, a methacryloxy group-containing compound and / or an epoxy group-containing compound.

  The acryloxy group-containing compound and methacryloxy group-containing compound to be used are generally acrylic acid or methacrylic acid derivatives, and examples thereof include acrylic acid or methacrylic acid esters and amides. Examples of ester residues include linear alkyl groups such as methyl, ethyl, dodecyl, stearyl, lauryl, cyclohexyl group, tetrahydrofurfuryl group, aminoethyl group, 2-hydroxyethyl group, 3-hydroxypropyl group. And 3-chloro-2-hydroxypropyl group. In addition, polyhydric alcohols such as ethylene glycol, triethylene glycol, polypropylene glycol, polyethylene glycol, trimethylolpropane, and pentaerythritol, and esters of acrylic acid or methacrylic acid can also be used.

  Examples of amides include diacetone acrylamide.

  Examples of polyfunctional compounds (crosslinking aids) include esters obtained by esterifying a plurality of acrylic acid or methacrylic acid with glycerin, trimethylolpropane, pentaerythritol, and the like, and the aforementioned triallyl cyanurate and triallyl isocyanurate. it can.

Examples of epoxy-containing compounds include triglycidyl tris (2-hydroxyethyl) isocyanurate, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and phenol. (Ethyleneoxy) ₅ glycidyl ether, pt-butylphenyl glycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, glycidyl methacrylate, butyl glycidyl ether can be mentioned.

  In the present invention, a silane coupling agent can be added as an adhesion improver in order to further enhance the adhesive force between the EVA layer and the glass plate or plastic film.

  Examples of this silane coupling agent include γ-chloropropylmethoxysilane, vinylethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltri Methoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- Mention may be made of β- (aminoethyl) -γ-aminopropyltrimethoxysilane. These silane coupling agents may be used alone or in combination of two or more. Moreover, it is preferable that content of the said compound is 5 mass parts or less with respect to 100 mass parts of EVA.

  The plasticizer is not particularly limited, but polybasic acid esters and polyhydric alcohol esters are generally used. Examples thereof include dioctyl phthalate, dihexyl adipate, triethylene glycol-di-2-ethylbutyrate, butyl sebacate, tetraethylene glycol diheptanoate, and triethylene glycol dipelargonate. One type of plasticizer may be used, or two or more types may be used in combination. The content of the plasticizer is preferably in the range of 5 parts by mass or less with respect to 100 parts by mass of EVA.

  The EVA sheet (layer) of the present invention is obtained by, for example, molding a composition containing the above-mentioned EVA, organic peroxide, ultraviolet absorber, etc. by ordinary extrusion molding, calendar molding (calendering) or the like to obtain a layered product. It can be manufactured by a method. The PVB sheet (layer) of the present invention is formed according to the method of the present invention. The EVA sheet (layer) is formed as described above and may be continuously conveyed to a pair of rolls, or may be previously formed as described above and used or conveyed when laminated with the PVB sheet. Also good.

  In order to produce the laminated glass of the present invention, for example, first, as described above, the intermediate film of the present invention is formed, the intermediate film is interposed between the glass plates, the laminated body is degassed, and then heated. What is necessary is just to press down and to carry out adhesion integration. Such a laminate can be obtained, for example, by a vacuum bag method or a nip roll method. Such lamination can be performed by pressure bonding by a nip roll method because the EVA layer is soft, and the production of the laminate becomes easy. It is preferable that the temperature of a nip roll is 80-140 degreeC. In the case of the EVA layer / PVB layer / EVA layer structure as in the present invention, the residual process of air is reduced, so that the degassing step (by autoclave) can be omitted.

  When manufacturing the said laminated glass, it is necessary to bridge | crosslink the EVA layer of an intermediate film generally at 100-150 degreeC (especially around 130 degreeC) for 10 minutes-1 hour. Such cross-linking is carried out at the temperature of 80 to 120 ° C., for example, at 100 to 150 ° C. (especially around 130 ° C.) after deaeration in the state of being sandwiched between the glass plates when producing laminated glass. The heat treatment is performed for 10 minutes to 1 hour. Cooling after crosslinking is generally performed at room temperature, and in particular, the faster the cooling, the better.

  As described above, one glass plate of the laminated glass of the present invention may be a film tempered glass as a plastic film, and the plastic film used in that case is a polyethylene terephthalate (PET) film or a polyethylene aphthalate (PEN) film. And polyethylene butyrate film, and PET film is preferred.

  When the hard coat layer is formed on the surface of the plastic film, an ultraviolet curable resin or a thermosetting resin is used as the resin used for that purpose. The hard coat layer generally has a thickness of 1 to 50 μm, preferably 3 to 20 μm.

  As the ultraviolet curable resin, a known ultraviolet curable resin can be used, and any other low molecular weight and multifunctional resin suitable for hard coat treatment is not particularly limited. Examples of the ultraviolet curable resin include urethane oligomers having a plurality of ethylenic double bonds, oligomers such as polyester oligomers and epoxy oligomers, pentaerythritol tetraacrylate (PETA), pentaerythritol tetramethacrylate, and dipentaerythritol hexaacrylate (DPEHA). The monofunctional or polyfunctional oligomers and the like are generally composed of a reactive diluent and a photopolymerization initiator. Furthermore, various additives can be contained. As the reactive diluent, the acryloxy group-containing compound, methacryloxy group-containing compound and / or epoxy group-containing compound used in the transparent adhesive layer can be used, and the transparent adhesive layer can also be used as a photopolymerization initiator. The compounds used in can be used.

  One kind of each of the oligomer, the reactive diluent and the initiator may be used, or two or more kinds thereof may be used in combination. As for content of a reactive diluent, 0.1-10 mass parts is common with respect to 100 mass parts of ultraviolet curable resin, and 0.5-5 mass parts is preferable. The content of the photopolymerization initiator is preferably 5 parts by mass or less with respect to 100 parts by mass of the ultraviolet curable resin.

  As the thermosetting resin, a reactive acrylic resin, a melamine resin, an epoxy resin, or the like can be used. The ultraviolet curable resin can also be used.

  When a hard coat layer is formed using an ultraviolet curable resin, the ultraviolet curable resin is diluted as it is or with an organic solvent to an appropriate concentration, and the resulting solution is applied to an appropriate film with an appropriate coating machine (coater). After coating on top and drying as necessary, a hard coat layer can be formed by irradiating with UV light for several seconds to several minutes directly or through a release sheet (after vacuum degassing) with a UV lamp. As the UV lamp, a high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, or the like can be used.

  When a hard coat layer is formed using a thermosetting resin, an organic solvent solution of the thermosetting resin is applied onto an appropriate film with an appropriate coating machine (coater), and a release sheet is provided if necessary, a laminator, etc. After degassing, heat curing and thermocompression bonding are performed. In the case where the release sheet is not used, it is preferable to dry for 60 seconds before heating and pressure bonding to evaporate the solvent of the coating layer and to prevent the surface from sticking. Even when a release sheet is used, it is preferable that the release sheet is provided after slightly drying.

  You may provide the transparent conductive layer which consists of a metal and / or a metal oxide in the surface of the glass plate of the laminated body obtained by this invention.

  A barrier layer may be formed on the side surface of the laminate obtained as described above. In general, the thickness of the barrier layer is preferably 0.1 to 20 μm and 1 to 10 μm.

  The laminate thus obtained can be used for the following applications. In other words, glass fitted in automobiles, side glass and rear glass, railway vehicles such as ordinary vehicles, express vehicles, express vehicles and sleeper vehicles, door windows for passenger doors, window glasses and indoor door glasses, windows in buildings, etc. Glass and indoor door glass, indoor display showcases and show windows. Preferably, it is useful for automobile side or rear glass, railcar window glass, especially automobile door glass.

  The following examples further illustrate the present invention.

[Example 1]
A long EVA sheet (width 1.0 m, length 200 m, thickness 0.2 mm) was obtained by a calendar molding method using the following composition as a raw material. The kneading of the blend was carried out at 80 ° C. for 15 minutes, the calender roll temperature was 80 ° C., and the processing speed was 5 m / min.
(Formulation for EVA sheet formation (parts by mass))
EVA resin (vinyl acetate content 26% by weight): 100
Cross-linking agent (1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane): 2.0
Silane coupling agent (γ-methacryloxypropyltrimethoxysilane): 0.5
Crosslinking aid (triallyl isocyanurate): 2.0
UV absorber (2,2′-dihydroxy-4,4′-dimethoxybenzophenone): 0.15

The following formulation:
(Formulation for PVB sheet formation (parts by mass))
PVB resin (degree of acetalization 66 mol%): 100
Plasticizer (triethylene glycol-di (2-ethylbutyrate)): 33
UV absorber (2,2′-dihydroxy-4,4′-dimethoxybenzophenone): 0.15
As shown in FIG. 1, the resin composition is put into an extruder 1 and extruded from a T-die (200 ° C.) 2 into a sheet (200 ° C.), and the extruded PVB sheet 3 is turned into a pair of rolls 5A, The sheet was inserted between the EVA sheets 4A and 4B obtained as described above and conveyed to 5B (10 ° C.). As a result, the three sheets are pressure-bonded by the pair of rolls 5A and 5B, and the laminated body composed of the EVA sheet 4A / PVB sheet 3 / EVA sheet 4B (thickness 0.2 mm / 0.8 mm / 0.2 mm). An intermediate film 6 was obtained.

[Comparative Example 1]
An intermediate film of a laminate composed of EVA sheet 4A / PVB sheet 3 / EVA sheet 4B using a T-die for three-layer extrusion (200 ° C.) using the formulation for EVA sheet formation and the formulation for PVB sheet formation in Example 1 Attempted to produce 6. However, the resin composition blended for forming the EVA sheet could not be produced because it gelled in the T-die.

[Evaluation of laminated glass]
Using the interlayer film obtained in Example 1, a laminated glass was produced and evaluated.

  As the glass plate, two silicate glass plates having a thickness of 2 mm that had been washed and dried in advance were prepared.

  Two glass plates were laminated through the EVA film / PVB sheet / EVA intermediate film obtained above, and pre-pressed at a temperature of 110 ° C. using a nip roll. Next, this pre-pressed glass was placed in an autoclave and held for 30 minutes under conditions of a temperature of 130 ° C. and a pressure of 1.2 MPa to produce a laminated glass (see FIG. 3).

(Penetration resistance)
According to the method described in JIS-R-3211 (1998), an impact was applied from one glass surface, and the penetration resistance property was investigated. The case of penetrating due to impact was marked with ◯, and the case of not penetrating was marked with ×.

  The above test was performed at 23 ° C. (room temperature) and −5 ° C. (low temperature).

(Sound insulation)
The sound transmission loss was investigated according to the method described in JIS-A-1416 (2000), and the sound transmission loss of sound of 3000 to 5000 Hz was examined. A value of 35 dB or more was given as ◯, and a value less than as x.

  The measurement results are shown below.

It is sectional drawing which shows an example of the manufacturing method of the intermediate film of this invention. An example of the basic structure of the intermediate film of the present invention is shown. An example of preferable embodiment of the laminated glass of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extruder 2 T die 3 PVB sheet 4A, 4B EVA sheet 5A, 5B Roll 6 Intermediate film 7, 9 Auxiliary roll 8 Cooling roll 22 Intermediate film 23A, 23B EVA layer
24 PVB layer 30 Laminated glass 31A, 31B Glass plate 32 Intermediate film

Claims (12)

Production of an interlayer film for laminated glass comprising a step of pressing and laminating two EVA sheets of a resin composition containing an ethylene / vinyl acetate copolymer and an organic peroxide through a PVB sheet of a resin composition containing polyvinyl butyral In the method
In the above step, a resin composition containing polyvinyl butyral is heated and extruded into a sheet shape, and the obtained softened PVB sheet is inserted between two EVA sheets, thereby producing an interlayer film for laminated glass Method. Production of an interlayer film for laminated glass comprising a step of pressing and laminating two EVA sheets of a resin composition containing an ethylene / vinyl acetate copolymer and an organic peroxide through a PVB sheet of a resin composition containing polyvinyl butyral In the method
In the above process, the resin composition containing polyvinyl butyral is heated and extruded from a T-die into a sheet shape, and the obtained softened PVB sheet is inserted between two EVA sheets conveyed between a pair of rolls. The manufacturing method of the intermediate film for laminated glasses characterized by the above-mentioned.   The manufacturing method according to claim 1 or 2, wherein the heat extrusion temperature of the resin composition containing polyvinyl butyral is in the range of 150 to 250 ° C.   The manufacturing method according to any one of claims 1 to 3, wherein the temperature of the two EVA sheets is in a range of 0 to 50 ° C.   The manufacturing method according to any one of claims 2 to 4, wherein the temperature of the T die is in a range of 150 to 250 ° C.   The manufacturing method according to any one of claims 2 to 5, wherein the temperature of the roll is in the range of -20 to 40 ° C.   The production method according to any one of claims 2 to 6, wherein the roll is an embossing roll or a guide roll.   The manufacturing method according to any one of claims 1 to 7, wherein the PVB sheet that has been heated and extruded is inserted between the two EVA sheets within 5 seconds after being extruded.   The manufacturing method according to any one of claims 1 to 8, wherein the thickness of each EVA layer is in the range of 0.1 to 1.0 mm.   The manufacturing method according to any one of claims 1 to 9, wherein the thickness of each PVB layer is in the range of 0.1 to 2.0 mm.   The production method according to any one of claims 1 to 10, wherein the vinyl acetate unit of the ethylene / vinyl acetate copolymer is in a range of 23 to 38% by mass with respect to 100 parts by mass of the ethylene vinyl acetate copolymer. The ethylene / vinyl acetate copolymer contains 0.05 to 4.0 parts by mass of an organic peroxide with respect to 100 parts by mass of the ethylene / vinyl acetate copolymer. The production method according to item.

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