JP2017178675A - Interlayer for laminated glass and laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interlayer for laminated glass which does not run out from between glass plates in a preliminary crimp step of laminate glass production, and to provide laminate glass using the interlayer for laminated glass.SOLUTION: Coefficient of expansion of a width direction measured after an interlayer for laminated glass 1 has been immersed in warm water of 80°C for 10 minutes is not more than 10%. Preferably a factor of shrinkage to a flow direction is not more than 15%, one end and another end in the other side are provided, and the thickness of the another end is thicker than the thickness of the one end.SELECTED DRAWING: Figure 1

Description

The present invention relates to an interlayer film for laminated glass that does not jump out from between glass plates when a pre-bonding step is performed in the production of laminated glass, and a laminated glass using the interlayer film for laminated glass.

Laminated glass obtained by sandwiching an interlayer film for laminated glass containing plasticized polyvinyl butyral between two glass plates and bonding them together is widely used particularly as a vehicle windshield.

In the method for producing laminated glass, for example, a laminated glass obtained by cutting an interlayer film for laminated glass unwound from a roll into an appropriate size and sandwiching the interlayer film for laminated glass between at least two glass plates. The body is put into a rubber bag and sucked under reduced pressure, pre-pressed while deaerating air remaining between the glass plate and the intermediate film, and then subjected to main pressure bonding by heating and pressurizing in an autoclave, for example (rubber back Method) or a laminated body in which an interlayer film for laminated glass is laminated between at least two glass plates is conveyed to a constant temperature by passing the laminated body through a heating zone while being conveyed using a conveyor. After that, the air remaining between the glass and the intermediate film is removed while being handled through the nip roll, and at the same time, the pressure between the intermediate film and the glass of the laminate is reduced by pre-pressure by thermocompression bonding. And, in the resulting state air reduced between laminate, a method of the present adhesive under high temperature and high pressure in an autoclave (nip roll method) has been performed. (For example, Patent Document 1)

In the above rubber pack method and nip roll method, when pre-bonding is performed, a part of the interlayer film for laminated glass jumps out between the two glass plates, contaminating the glass and manufacturing equipment, or damaging the operator. There was a problem that there was something. Such a jump-out of the interlayer film for laminated glass is particularly prominent when a car windshield having a curved surface is pre-press-bonded.

JP-A-8-26789

In view of the above-described situation, the present invention provides an interlayer film for laminated glass that does not jump out from between glass plates when a pre-bonding step is performed in the production of laminated glass, and a laminated glass using the interlayer film for laminated glass. The purpose is to provide.

The present invention has an expansion coefficient in the width direction of 10% or less measured after immersing the interlayer film for laminated glass in warm water at 80 ° C. for 10 minutes, and has one end and the other end on the opposite side of the one end. The thickness of the said other end is an intermediate film for laminated glasses larger than the thickness of the said one end.
The present invention is described in detail below.

The present inventors examined the cause of the phenomenon that the interlayer film for laminated glass jumps out between the two glass plates at the time of pre-bonding. As a result, it was found that the interlayer film for laminated glass contracted and expanded when heated during pre-bonding. That is, in the production of an interlayer film for laminated glass, a resin film obtained by extruding a raw resin composition from an extruder is wound using a roll. Moreover, when embossing is performed on the surface of the interlayer film for laminated glass, the film is passed between the embossing rolls while applying temperature. Through such a process, the stress is accumulated in the interlayer film for laminated glass because it is fixed while being pulled in the flow direction. On the other hand, in the pre-compression bonding process for manufacturing laminated glass, the interlayer film for laminated glass is heated to about 50 to 80 ° C. and becomes soft. At this time, the softened interlayer film for laminated glass is subjected to a force to shrink in the flow direction and a force to expand in the width direction due to the accumulated stress. It was thought that the phenomenon of jumping out between two glass plates occurred.

As a result of further diligent studies, the inventors of the present invention preliminarily used in the production of laminated glass by setting the expansion coefficient in the width direction measured after immersing the interlayer film for laminated glass in warm water at 80 ° C. for 10 minutes to 10% or less. The inventors have found that the interlayer film for laminated glass can be prevented from jumping out between the glass plates when the crimping process is performed, and the present invention has been completed.
Here, the temperature setting of 80 ° C. reflects the heating conditions at the time of pre-bonding, and more accurate measurement can be performed by heating in warm water.

The interlayer film for laminated glass of the present invention has an expansion coefficient in the width direction of 10% or less measured after the interlayer film for laminated glass is immersed in warm water at 80 ° C. for 10 minutes. Thereby, when performing the precompression bonding process in the production of laminated glass, the interlayer film for laminated glass can be prevented from jumping out between the glass plates. The expansion coefficient in the width direction of the interlayer film for laminated glass is preferably 7% or less, and more preferably 5% or less.

In this specification, the flow direction of the interlayer film for laminated glass means the direction in which the raw resin composition is extruded from the extruder during the production of the interlayer film for laminated glass. The width direction of the interlayer film for laminated glass means a coplanar direction orthogonal to the flow direction.
In addition, the flow direction of the interlayer film for laminated glass can be confirmed by the following method, for example. That is, after the interlayer film for laminated glass is stored in a constant temperature bath at 140 ° C. for 30 minutes, it can be confirmed that the larger shrinkage rate in the parallel direction and the perpendicular direction of the film is the flow direction. In addition, it can confirm by the winding direction of the roll-shaped body of this intermediate film for laminated glasses. This is because the roll-shaped body of the interlayer film for laminated glass is wound up in the flow direction of the film during the production of the interlayer film for laminated glass. This is because the flow direction of the membrane is the same.

The interlayer film for laminated glass of the present invention has one end and the other end opposite to the one end. The one end and the other end are end portions on both sides facing each other in the intermediate film. In the interlayer film for laminated glass of the present invention, the thickness of the other end is larger than the thickness of the one end. When the laminated glass using the interlayer film for laminated glass of the present invention is used as a head-up display, the double image can be effectively suppressed by having a shape in which the thicknesses of the one end and the other end are different.

The interlayer film for laminated glass of the present invention preferably has a shrinkage in the flow direction of 15% or less measured after the interlayer film for laminated glass is immersed in warm water at 80 ° C. for 10 minutes. Thereby, when performing the precompression bonding process in the production of laminated glass, the interlayer film for laminated glass can be more reliably prevented from jumping out between the glass plates. The shrinkage ratio in the flow direction of the interlayer film for laminated glass is more preferably 10% or less.

The method for measuring the expansion coefficient in the width direction and the contraction ratio in the flow direction of the interlayer film for laminated glass in the present invention will be described in more detail with reference to FIG.
In FIG. 1A, first, the interlayer film 1 for laminated glass is drawn out from the roll-shaped body 2. At this time, the drawn-out direction is the flow direction of the interlayer film for laminated glass, and the coplanar direction perpendicular to the flow direction is the width direction.
The drawn interlayer film for laminated glass is cut at a position of 20 cm in the flow direction to obtain a test sample 3 of 20 cm × film width (usually 100 cm) (FIG. 1B). The test sample 3 is preferably placed on a flat surface under the conditions of 20 ° C. and 30% RH and cured for 24 hours before being subjected to measurement.
After curing, at least 3 marks are marked on the test sample 3 under the conditions of 20 ° C. and 30% RH. In FIG. 1 (b), cross-shaped marked lines 41, 42, and 43 are entered at three locations on the test sample 3. As for each marked line, a cross-shaped line is written with a length of 15 cm in the flow direction and the width direction of the interlayer film for laminated glass. In FIG. 1 (b), the marked line 41 is written in the central part in the flow direction and the width direction of the test sample 3, and the marked lines 42 and 43 are the central part in the flow direction of the test sample 3 in the width direction. I wrote it near the edge. However, the marked lines 42 and 43 were written so that the ends of the lines were separated from the end in the width direction of the test sample 3 by about 10 cm.
The test sample 3 with the marked line is immersed in warm water of 80 ° C. for 10 minutes (FIG. 1 (c)). It is preferable that the test sample after immersion in warm water is immediately immersed in water at 20 ° C. or lower for 10 minutes or longer and then cooled (FIG. 1 (d)).
The test sample 3 after cooling is taken out and the surface moisture is lightly wiped, and then the lengths in the flow direction and the width direction of the marked lines 41, 42, 43 are measured. The measurement is preferably performed within 5 minutes after taking out the test sample 3 (FIG. 1 (e)).
The expansion coefficient in the width direction and the shrinkage ratio in the flow direction of the interlayer film for laminated glass can be calculated by the following formulas (1) and (2), and the average of the values obtained by measuring at least two marked lines Is taken as the expansion rate in the width direction and the contraction rate in the flow direction.

The interlayer film for laminated glass of the present invention preferably contains a thermoplastic resin.
Examples of the thermoplastic resin include polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, polytrifluoride ethylene, acrylonitrile-butadiene-styrene copolymer, polyester, polyether, and polyamide. , Polycarbonate, polyacrylate, polymethacrylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyvinyl acetal, ethylene-vinyl acetate copolymer and the like. Especially, since it is easy to manufacture the intermediate film for laminated glasses which satisfy | fills the expansion coefficient of the said width direction, and the shrinkage | contraction rate of a flow direction, polyvinyl acetal is suitable.

The polyvinyl acetal resin can be produced, for example, by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The degree of saponification of PVA is generally in the range of 70-99.9 mol%.

The degree of polymerization of polyvinyl alcohol PVA for obtaining the polyvinyl acetal resin is preferably 200 or more, more preferably 500 or more, still more preferably 1700 or more, particularly preferably 2000 or more, preferably 5000 or less, more preferably 4000 or less, More preferably, it is 3000 or less, More preferably, it is less than 3000, Most preferably, it is 2800 or less. The polyvinyl acetal resin is preferably a polyvinyl acetal resin obtained by acetalizing PVA having a degree of polymerization of not less than the above lower limit and not more than the above upper limit. When the polymerization degree is equal to or higher than the lower limit, the penetration resistance of the laminated glass is further enhanced. When the polymerization degree is not more than the above upper limit, the intermediate film can be easily molded.

The degree of polymerization of PVA indicates the average degree of polymerization. The average degree of polymerization is determined by a method based on JIS K6726 “Testing method for polyvinyl alcohol”. In general, an aldehyde having 1 to 10 carbon atoms is preferably used as the aldehyde. Examples of the aldehyde having 1 to 10 carbon atoms include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, Examples include n-nonyl aldehyde, n-decyl aldehyde, and benzaldehyde. Among these, n-butyraldehyde, n-hexylaldehyde or n-valeraldehyde is preferable, and n-butyraldehyde is more preferable. As for the said aldehyde, only 1 type may be used and 2 or more types may be used together.

The polyvinyl acetal resin contained in the interlayer film is preferably a polyvinyl butyral resin. By using the polyvinyl butyral resin, the weather resistance of the interlayer film with respect to the laminated glass member is further enhanced.

The interlayer film for laminated glass of the present invention preferably contains a plasticizer.
The plasticizer is not particularly limited as long as it is a plasticizer generally used for an interlayer film for laminated glass. For example, organic plasticizers such as monobasic organic acid esters and polybasic organic acid esters, organic Examples thereof include phosphoric acid plasticizers such as phosphoric acid compounds and organic phosphorous acid compounds.
Examples of the organic plasticizer include triethylene glycol-di-2-ethylhexanoate, triethylene glycol-di-2-ethylbutyrate, triethylene glycol-di-n-heptanoate, and tetraethylene glycol-di-2. -Ethylhexanoate, tetraethylene glycol-di-2-ethylbutyrate, tetraethylene glycol-di-n-heptanoate, diethylene glycol-di-2-ethylhexanoate, diethylene glycol-di-2-ethylbutyrate, diethylene glycol -Di-n-heptanoate etc. are mentioned. Among them, it is preferable to contain triethylene glycol-di-2-ethylhexanoate, triethylene glycol-di-2-ethylbutyrate, or triethylene glycol-di-n-heptanoate. More preferably, it contains 2-ethylhexanoate.

In the interlayer film for laminated glass of the present invention, the content of the plasticizer with respect to the thermoplastic resin is not particularly limited. The content of the plasticizer with respect to 100 parts by mass of the thermoplastic resin is preferably 25 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 35 parts by mass or more, preferably 80 parts by mass or less, more preferably. Is 60 parts by weight or less, more preferably 50 parts by weight or less. When the content of the plasticizer is not less than the above lower limit, the penetration resistance of the laminated glass is further enhanced. When the content of the plasticizer is not more than the above upper limit, the transparency of the interlayer film is further enhanced.

The interlayer film for laminated glass of the present invention preferably contains an adhesive strength modifier.
As said adhesive force regulator, an alkali metal salt or alkaline-earth metal salt is used suitably, for example. As said adhesive force regulator, salts, such as potassium, sodium, magnesium, are mentioned, for example.
Examples of the acid constituting the salt include organic acids of carboxylic acids such as octylic acid, hexylic acid, 2-ethylbutyric acid, butyric acid, acetic acid, formic acid, and inorganic acids such as hydrochloric acid and nitric acid.

The interlayer film for laminated glass of the present invention includes, as necessary, a modified silicone oil, a flame retardant, an antistatic agent, a moisture-resistant agent, a heat ray reflective agent, a heat ray absorbent, as an antioxidant, a light stabilizer, and an adhesion modifier. You may contain additives, such as a coloring agent which consists of an antiblocking agent, an antistatic agent, and a pigment or dye.

The interlayer film for laminated glass of the present invention may have a single-layer structure composed of only one resin film or a multilayer structure in which two or more resin layers are laminated.
When the interlayer film for laminated glass of the present invention has a multilayer structure, it has a first resin layer and a second resin layer as two or more resin layers, and the first resin layer and the second resin layer Since the two resin layers have different properties, it is possible to provide an interlayer film for laminated glass having various performances that have been difficult to achieve with only one layer.

When the interlayer film for laminated glass of the present invention has a multilayer structure, for example, in order to improve the sound insulation of the laminated glass, the first resin layer is a protective layer and the second resin layer is a sound insulation layer. An interlayer film for laminated glass (hereinafter, also referred to as “sound insulating interlayer”) having excellent sound insulating properties, in which a sound insulating layer is sandwiched between two protective layers.
Hereinafter, the sound insulation interlayer will be described more specifically.

In the sound insulating interlayer, the sound insulating layer has a role of providing sound insulating properties.
The sound insulation layer preferably contains polyvinyl acetal X and a plasticizer.
The polyvinyl acetal X can be prepared by acetalizing polyvinyl alcohol with an aldehyde. The polyvinyl acetal X is preferably an acetalized product of polyvinyl alcohol. The polyvinyl alcohol is usually obtained by saponifying polyvinyl acetate.
The preferable lower limit of the polymerization degree of the polyvinyl alcohol is 200, and the preferable upper limit is 5000. By setting the polymerization degree of the polyvinyl alcohol to 200 or more, the penetration resistance of the obtained sound insulating interlayer can be improved, and by setting it to 5000 or less, the moldability of the sound insulating layer can be ensured. The minimum with a more preferable polymerization degree of the said polyvinyl alcohol is 500, and a more preferable upper limit is 4000.

The preferable lower limit of the carbon number of the aldehyde for acetalizing the polyvinyl alcohol is 4, and the preferable upper limit is 6. By setting the number of carbon atoms in the aldehyde to 4 or more, a sufficient amount of plasticizer can be stably contained, and excellent sound insulation performance can be exhibited. In addition, bleeding out of the plasticizer can be prevented. By setting the number of carbon atoms in the aldehyde to 6 or less, the synthesis of polyvinyl acetal X can be facilitated and productivity can be ensured.
The aldehyde having 4 to 6 carbon atoms may be a linear aldehyde or a branched aldehyde, and examples thereof include n-butyraldehyde and n-valeraldehyde. .

The upper limit with the preferable amount of hydroxyl groups of the said polyvinyl acetal X is 30 mol%. By setting the amount of hydroxyl groups in the polyvinyl acetal X to 30 mol% or less, it is possible to contain an amount of a plasticizer necessary for exhibiting sound insulation, and to prevent bleeding out of the plasticizer. The more preferable upper limit of the hydroxyl group amount of the polyvinyl acetal X is 28 mol%, the more preferable upper limit is 26 mol%, the particularly preferable upper limit is 24 mol%, the preferable lower limit is 10 mol%, the more preferable lower limit is 15 mol%, and the more preferable lower limit. Is 20 mol%.
The amount of hydroxyl groups in the polyvinyl acetal X is a value obtained by dividing the amount of ethylene groups to which the hydroxyl groups are bonded by the total amount of ethylene groups in the main chain, as a percentage (mol%). The amount of ethylene group to which the hydroxyl group is bonded can be determined, for example, by measuring the amount of ethylene group to which the hydroxyl group of polyvinyl acetal X is bonded by a method based on JIS K6728 “Testing method for polyvinyl butyral”. it can.

The minimum with the preferable amount of acetal groups of the said polyvinyl acetal X is 60 mol%, and a preferable upper limit is 85 mol%. By setting the amount of acetal group of the polyvinyl acetal X to 60 mol% or more, it is possible to increase the hydrophobicity of the sound insulation layer and to contain a plasticizer in an amount necessary for exhibiting sound insulation. Bleed out and whitening can be prevented. By setting the amount of acetal groups of the polyvinyl acetal X to 85 mol% or less, the synthesis of the polyvinyl acetal X can be facilitated and productivity can be ensured. The amount of the acetal group can be determined by measuring the amount of ethylene group to which the acetal group of the polyvinyl acetal X is bonded by a method based on JIS K6728 “Testing method for polyvinyl butyral”.

The minimum with the preferable amount of acetyl groups of the said polyvinyl acetal X is 0.1 mol%, and a preferable upper limit is 30 mol%. By setting the amount of acetyl groups in the polyvinyl acetal X to 0.1 mol% or more, an amount of a plasticizer necessary for exhibiting sound insulation can be contained, and bleeding out can be prevented. Moreover, the hydrophobicity of a sound insulation layer can be made high and whitening can be prevented by making the amount of acetyl groups of the said polyvinyl acetal X into 30 mol% or less. The more preferable lower limit of the acetyl group amount is 1 mol%, the more preferable lower limit is 5 mol%, the particularly preferable lower limit is 8 mol%, the more preferable upper limit is 25 mol%, and the still more preferable upper limit is 20 mol%. The amount of acetyl groups is the value obtained by subtracting the amount of ethylene groups to which acetal groups are bonded and the amount of ethylene groups to which hydroxyl groups are bonded from the total amount of ethylene groups in the main chain. This is a value expressed as a percentage (mol%) of the mole fraction obtained by dividing by.

In particular, since the above-mentioned sound insulation layer can easily contain a plasticizer in an amount necessary to exhibit sound insulation, the above-mentioned polyvinyl acetal X is a polyvinyl acetal having an acetyl group content of 8 mol% or more, or Polyvinyl acetal having an acetyl group amount of less than 8 mol% and an acetal group amount of 68 mol% or more is preferred.

As for content of the plasticizer in the said sound-insulation layer, the preferable minimum with respect to 100 mass parts of said polyvinyl acetals X is 45 mass parts, and a preferable upper limit is 80 mass parts. By setting the content of the plasticizer to 45 parts by mass or more, high sound insulation can be exhibited, and by setting it to 80 parts by mass or less, bleeding out of the plasticizer occurs, and the interlayer film for laminated glass Decrease in transparency and adhesiveness can be prevented. The more preferred lower limit of the plasticizer content is 50 parts by mass, the still more preferred lower limit is 55 parts by mass, the more preferred upper limit is 75 parts by mass, and the still more preferred upper limit is 70 parts by mass.

The interlayer film for laminated glass of the present invention may have one end as the whole laminated glass and the other end on the opposite side of the one end, and the other end has a thickness larger than the thickness of the one end. The thickness of the sound insulation layer may be uniform or different throughout the sound insulation layer. The sound insulation layer may have one end and the other end opposite to the one end, and the other end may have a shape larger than the thickness of the one end. The sound insulation layer preferably has a portion having a wedge-shaped cross-sectional shape in the thickness direction. A preferable lower limit of the minimum thickness of the sound insulation layer is 50 μm. By setting the minimum thickness of the sound insulation layer to 50 μm or more, sufficient sound insulation can be exhibited. A more preferable lower limit of the minimum thickness of the sound insulating layer is 80 μm, and a more preferable lower limit is 100 μm. In addition, although the upper limit of the maximum thickness of the said sound-insulating layer is not specifically limited, Considering the thickness as an intermediate film for laminated glasses, a preferable upper limit is 300 micrometers. A more preferable upper limit of the maximum thickness of the sound insulation layer is 220 μm.

The above-mentioned protective layer prevents bleeding of a large amount of plasticizer contained in the sound insulation layer, resulting in a decrease in the adhesion between the interlayer film for laminated glass and the glass. Has the role of granting.
The protective layer preferably contains, for example, polyvinyl acetal Y and a plasticizer, and more preferably contains polyvinyl acetal Y having a larger amount of hydroxyl group than polyvinyl acetal X and a plasticizer.

The polyvinyl acetal Y can be prepared by acetalizing polyvinyl alcohol with an aldehyde. The polyvinyl acetal Y is preferably an acetalized product of polyvinyl alcohol.
The polyvinyl alcohol is usually obtained by saponifying polyvinyl acetate. Moreover, the preferable minimum of the polymerization degree of the said polyvinyl alcohol is 200, and a preferable upper limit is 5000. By setting the polymerization degree of the polyvinyl alcohol to 200 or more, the penetration resistance of the interlayer film for laminated glass can be improved, and by setting it to 5000 or less, the moldability of the protective layer can be ensured. The minimum with a more preferable polymerization degree of the said polyvinyl alcohol is 500, and a more preferable upper limit is 4000.

The preferable lower limit of the carbon number of the aldehyde for acetalizing the polyvinyl alcohol is 3, and the preferable upper limit is 4. By setting the number of carbon atoms of the aldehyde to 3 or more, the penetration resistance of the interlayer film for laminated glass is increased. By making the carbon number of the aldehyde 4 or less, the productivity of the polyvinyl acetal Y is improved.
The aldehyde having 3 to 4 carbon atoms may be a linear aldehyde or a branched aldehyde, and examples thereof include n-butyraldehyde.

The upper limit with the preferable amount of hydroxyl groups of the said polyvinyl acetal Y is 33 mol%, and a preferable minimum is 28 mol%. By making the amount of hydroxyl groups in the polyvinyl acetal Y 33 mol% or less, whitening of the interlayer film for laminated glass can be prevented. By making the amount of hydroxyl groups in the polyvinyl acetal Y 28 mol% or more, the penetration resistance of the interlayer film for laminated glass is increased.

In the polyvinyl acetal Y, the preferable lower limit of the amount of acetal group is 60 mol%, and the preferable upper limit is 80 mol%. By setting the amount of the acetal group to 60 mol% or more, an amount of plasticizer necessary for exhibiting sufficient penetration resistance can be contained. By making the amount of the acetal group 80 mol% or less, it is possible to ensure the adhesive force between the protective layer and the glass. A more preferable lower limit of the amount of the acetal group is 65 mol%, and a more preferable upper limit is 69 mol%.

The upper limit with the preferable amount of acetyl groups of the said polyvinyl acetal Y is 7 mol%. By making the amount of acetyl groups of the polyvinyl acetal Y 7 mol% or less, the hydrophobicity of the protective layer can be increased and whitening can be prevented. A more preferable upper limit of the amount of the acetyl group is 2 mol%, and a preferable lower limit is 0.1 mol%. In addition, the amount of hydroxyl groups, the amount of acetal groups, and the amount of acetyl groups of polyvinyl acetal Y can be measured by the same method as for polyvinyl acetal X.

As for content of the plasticizer in the said protective layer, the preferable minimum with respect to 100 mass parts of said polyvinyl acetals Y is 20 mass parts, and a preferable upper limit is 45 mass parts. By setting the content of the plasticizer to 20 parts by mass or more, penetration resistance can be ensured, and by setting the content to 45 parts by mass or less, bleeding out of the plasticizer is prevented, and an interlayer film for laminated glass It is possible to prevent a decrease in transparency and adhesiveness. The more preferred lower limit of the plasticizer content is 30 parts by mass, the still more preferred lower limit is 35 parts by mass, the more preferred upper limit is 43 parts by mass, and the still more preferred upper limit is 41 parts by mass. Since the sound insulation of the laminated glass is further improved, the plasticizer content in the protective layer is preferably smaller than the plasticizer content in the sound insulation layer.

Since the sound insulation of the laminated glass is further improved, the amount of hydroxyl group of the polyvinyl acetal Y is preferably larger than the amount of hydroxyl group of the polyvinyl acetal X, more preferably 1 mol% or more, further preferably 5 mol% or more. It is particularly preferably 8 mol% or more. By adjusting the amount of hydroxyl groups of polyvinyl acetal X and polyvinyl acetal Y, the plasticizer content in the sound insulation layer and the protective layer can be controlled, and the glass transition temperature of the sound insulation layer is lowered. As a result, the sound insulation of the laminated glass is further improved.
Moreover, since the sound insulation of the laminated glass is further improved, the content of the plasticizer (hereinafter also referred to as content X) relative to 100 parts by mass of the polyvinyl acetal X100 in the sound insulation layer is the polyvinyl acetal Y100 in the protective layer. It is preferably more than the content of plasticizer (hereinafter also referred to as “content Y”) relative to parts by mass, more preferably 5 parts by mass or more, still more preferably 15 parts by mass or more, and more than 20 parts by mass. It is particularly preferred. By adjusting the content X and the content Y, the glass transition temperature of the sound insulation layer is lowered. As a result, the sound insulation of the laminated glass is further improved.

The interlayer film for laminated glass of the present invention may have one end as the whole laminated glass and the other end on the opposite side of the one end, and the other end has a thickness larger than the thickness of the one end. The thickness of the protective layer may be uniform throughout the protective layer or may be different. The protective layer may have one end and the other end opposite to the one end, and the thickness of the other end may be larger than the thickness of the one end. The protective layer preferably has a portion having a wedge-shaped cross-sectional shape in the thickness direction.
The thickness of the protective layer is not particularly limited as long as it is adjusted to a range that can serve as the protective layer. However, when the protective layer has irregularities, it is preferable to increase the thickness as much as possible so as to prevent the irregularities from being transferred to the interface with the sound insulating layer that is in direct contact therewith. Specifically, a preferable lower limit of the minimum thickness of the protective layer is 100 μm, a more preferable lower limit is 300 μm, a still more preferable lower limit is 400 μm, and a particularly preferable lower limit is 450 μm. The upper limit of the maximum thickness of the protective layer is not particularly limited, but in order to ensure the thickness of the sound insulation layer to the extent that sufficient sound insulation can be achieved, the upper limit is substantially about 1000 μm, and preferably 800 μm. .

The interlayer film for laminated glass of the present invention preferably has a portion having a wedge-shaped cross section in the thickness direction as the entire interlayer film for laminated glass. The cross-sectional shape in the thickness direction of the entire interlayer film for laminated glass is a wedge shape, so that when a laminated glass using the interlayer film for laminated glass of the present invention is used as a head-up display, the generation of double images is effective. Can be prevented. When the cross-sectional shape in the thickness direction has a wedge-shaped portion, the wedge angle θ of the entire interlayer film for laminated glass is preferably 0.01 mrad or more because it can effectively prevent generation of a double image. 0.2 mrad or more is more preferable, 2 mrad or less is preferable, and 0.7 mrad or less is more preferable.

The total thickness of the interlayer film for laminated glass of the present invention is not particularly limited. The minimum thickness of the entire interlayer film for laminated glass of the present invention is preferably 250 μm or more, and more preferably 800 μm or more because the penetration resistance of the laminated glass is sufficiently improved. Moreover, since the handleability of the interlayer film for laminated glass is sufficiently improved, the maximum thickness of the entire interlayer film for laminated glass of the present invention is preferably 2800 μm or less, more preferably 1800 μm or less, and 1200 μm. More preferably, it is as follows.

When the distance between one end and the other end is X, the intermediate film has a minimum thickness in a region of a distance of 0X to 0.2X from one end to the inside, and 0X from the other end to the inside. It is preferable to have a maximum thickness in a region with a distance of ˜0.2X, and the intermediate film has a minimum thickness in a region with a distance of 0X to 0.1X from one end to the inside, and from the other end to the inside. It is more preferable to have the maximum thickness in a region with a distance of 0X to 0.1X. Preferably, the intermediate film has a minimum thickness at one end and the intermediate film has a maximum thickness at the other end.

The method for producing the sound insulation interlayer is not particularly limited.For example, after the sound insulation layer and the protective layer are formed into a sheet by a normal film formation method such as an extrusion method, a calendar method, and a press method, The method of laminating etc. is mentioned.

The method for producing the interlayer film for laminated glass of the present invention is not particularly limited, and can be produced by a method of extruding the raw resin composition from an extruder. Here, by controlling the conditions at the time of extrusion molding, an interlayer film for laminated glass that satisfies the expansion coefficient in the width direction and the shrinkage ratio in the flow direction can be obtained. Moreover, when embossing is performed on the surface of the interlayer film for laminated glass, it is difficult to obtain an interlayer film for laminated glass satisfying the expansion coefficient in the width direction and the shrinkage ratio in the flow direction by the method using an embossing roll. It is preferable to employ a lip method that gives irregularities by devising the shape of the die of the die of the extruder.
Specifically, the speed difference of each roll through which the resin film discharged from the mold of the extruder passes until winding is adjusted to 15% or less. In addition, the roll through which the resin film discharged from the mold first passes is placed below the mold and ahead of the mold in the flow direction. Furthermore, the amount of extrusion from the extruder is adjusted to 500 to 800 kg / h, and the speed of the first roll is adjusted to 5 to 10 m / min. By controlling these extrusion conditions, an interlayer film for laminated glass that satisfies the expansion coefficient in the width direction and the shrinkage ratio in the flow direction can be obtained.

The laminated glass in which the interlayer film for laminated glass of the present invention is laminated between a pair of glass plates is also one aspect of the present invention.
The said glass plate can use the transparent plate glass generally used. Examples thereof include inorganic glass such as float plate glass, polished plate glass, template glass, netted glass, wire-containing plate glass, colored plate glass, heat ray absorbing glass, heat ray reflecting glass, and green glass. Further, an ultraviolet shielding glass having an ultraviolet shielding coating layer formed on the glass surface can also be used. Furthermore, organic plastics plates such as polyethylene terephthalate, polycarbonate, and polyacrylate can also be used.
Two or more types of glass plates may be used as the glass plate. For example, the laminated glass which laminated | stacked the intermediate film for laminated glasses of this invention between transparent float plate glass and colored glass plates like green glass is mentioned. Moreover, you may use the glass plate from which 2 or more types of thickness differs as said glass plate.

According to the present invention, there is provided an interlayer film for laminated glass that does not protrude from between glass plates when a pre-bonding step is performed in the production of laminated glass, and a laminated glass using the interlayer film for laminated glass. be able to.

It is a schematic diagram explaining the method of measuring the expansion coefficient of the width direction of the intermediate film for laminated glasses, and the shrinkage ratio of the flow direction.

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

Example 1
(Preparation of resin composition for protective layer)
For 100 parts by mass of polyvinyl butyral obtained by acetalizing polyvinyl alcohol having an average polymerization degree of 1700 with n-butyraldehyde (acetyl group content 1 mol%, butyral group content 69 mol%, hydroxyl group content 30 mol%) Then, 36 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) was added as a plasticizer. Further, a mixture of magnesium 2-ethylbutyrate and magnesium acetate (1: 1 by mass) was added as an adhesive strength modifier so that the magnesium content was 50 ppm. The mixture was sufficiently kneaded with a mixing roll to obtain a protective layer resin composition.

(Preparation of intermediate layer resin composition)
Polyvinyl butyral obtained by acetalizing polyvinyl alcohol having an average polymerization degree of 2300 with n-butyraldehyde (acetyl group amount 12.5 mol%, butyral group amount 64 mol%, hydroxyl group amount 23.5 mol%) 100 76.5 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer is added to parts by mass, and kneaded sufficiently with a mixing roll to obtain a resin composition for an intermediate layer. .

(Preparation of interlayer film for laminated glass)
The obtained intermediate layer resin composition and protective layer resin composition are coextruded using a coextrusion machine, whereby the first protective layer and the intermediate layer resin composition are formed of the protective layer resin composition. An intermediate film for laminated glass having a three-layer structure in which an intermediate layer made of the above and a second protective layer made of a resin composition for the protective layer were laminated in this order was obtained and wound into a roll.
In addition, in the interlayer film for laminated glass obtained after providing the unevenness, the first protective layer has a wedge-shaped cross-sectional shape in the thickness direction, the maximum thickness is 525 μm, the minimum thickness is 350 μm, and the cross-sectional shape in the thickness direction of the intermediate layer is wedge-shaped. The thickness is 150 μm, the minimum thickness is 100 μm, the cross-sectional shape in the thickness direction of the second protective layer is wedge-shaped, the maximum thickness is 525 μm, the minimum thickness is 350 μm, the cross-sectional shape in the thickness direction of the entire intermediate film is wedge-shaped, the maximum thickness is 1200 μm, Extrusion conditions were set so that the minimum thickness was 800 μm and the width was 100 cm. At this time, when the temperature of the lip mold is in the range of 100 ° C. to 280 ° C., the end portion where the entire thickness of the intermediate film is thin in the width direction is low temperature, and the end portion where the entire thickness of the intermediate film is thick is the high temperature side. Adjust the temperature gradient to adjust the temperature of the mold and adjust the gap of the lip as a lip mold in the range of 1.0 to 4.0 mm, and the resin film discharged from the lip mold Adjust the speed difference of each roll that passes until winding to 15% or less, and the first roll through which the resin film discharged from the lip mold passes is below the mold and flows from the mold. It was installed so as to be in front of the direction, and the amount of extrusion from the extruder was adjusted to 700 kg / h, and the speed of the first passing roll was adjusted to 7 m / min.

(Examples 2-5, Comparative Examples 1-2)
The minimum thickness, maximum thickness and cross-sectional shape of the first protective layer, the intermediate layer, the second protective layer and the entire intermediate film were changed as shown in Table 1, and the temperature and temperature gradient of the lip mold, extrusion conditions, lip An interlayer film for laminated glass was obtained in the same manner as in Example 1 except that the difference in speed between the rolls through which the resin film discharged from the mold passed until winding and the speed of the roll that first passed through were changed.

(Evaluation)
The interlayer films for laminated glass obtained in Examples and Comparative Examples were evaluated by the following methods.
The results are shown in Table 1.

(1) Evaluation of expansion rate and shrinkage rate of interlayer film for laminated glass after immersion at 80 ° C. in hot water Based on the method described in FIG. It was measured. That is, an interlayer film for laminated glass was pulled out from the roll and cut at a position of 20 cm in the flow direction to obtain a test sample of 20 cm × 100 cm. The obtained test sample was placed on a flat surface under the conditions of 20 ° C. and 30% RH or less and cured for 24 hours. When the interlayer film for laminated glass was immersed in warm water at 80 ° C., it was submerged in the bottom of the water tank, being careful not to generate wrinkles during the immersion.
Subsequently, a cross-shaped marked line having a length of 15 cm was written at three locations on the test sample (a central portion in the flow direction and a portion 10 cm away from each end portion in the width direction).
The test sample with the marked line was immersed in warm water at 80 ° C. for 10 minutes, and then immersed in water at 20 ° C. or lower for 10 minutes or longer and cooled. The sample for a test after cooling was taken out, the surface water | moisture content was lightly wiped immediately, and the length of the flow direction of each marked line and the width direction was measured within 5 minutes.
The expansion rate in the width direction and the shrinkage rate in the flow direction of the interlayer film for laminated glass are calculated by the above formulas (1) and (2), and the average of the measured values at the three marked lines is taken to expand in the width direction. Rate and shrinkage in the flow direction.

(2) Evaluation of pop-out amount of interlayer film for laminated glass during pre-bonding 24 hours under conditions of 23 ° C. and 30% RH between two Teflon (registered trademark) sheets (thickness 3 mm, 25 cm × 25 cm) While the laminated body on which the cured intermediate film for laminated glass (25 cm × 25 cm) is laminated is conveyed using a conveyor, the laminated body is passed through the heating zone, and the temperature of the intermediate film immediately after the heating zone is 55 ° C. I tried to become. Immediately after reaching this temperature, the laminate was immersed in water at 20 ° C. or lower within 10 seconds and cooled for 10 minutes or longer. After cooling, the intermediate film was taken out, the surface was wiped off, and cured for 24 hours under conditions of 23 ° C. and 30% RH.
Pre-laminated glass interlayer is previously marked with a mark in the width direction at the 5 cm and 20 cm positions from the leading side that passes through the heating zone in the flow direction. The lengths of the lines were compared, and the pop-out amount was calculated by the following formula (3).
The average value of the obtained pop-out amount at the 5 cm position and the pop-out amount at the 20 cm position was calculated and used as the pop-out amount of the interlayer film for laminated glass at the time of pre-bonding.

If the amount of protrusion of the interlayer film for laminated glass at the time of pre-bonding is less than 1.5%, the glass and the manufacturing equipment are not contaminated and the operator is not damaged. Therefore, the case where the amount of protrusion of the interlayer film for laminated glass during pre-bonding was less than 1.5% was evaluated as “◯”, and the case where it was 1.5% or more was evaluated as “X”.

According to the present invention, there is provided an interlayer film for laminated glass that does not protrude from between glass plates when a pre-bonding step is performed in the production of laminated glass, and a laminated glass using the interlayer film for laminated glass. be able to.

DESCRIPTION OF SYMBOLS 1 Intermediate film for laminated glass 2 Roll-shaped body 3 Test samples 41, 42, 43 Mark line

Claims (3)

The expansion coefficient in the width direction measured after immersing the interlayer film for laminated glass in warm water at 80 ° C. for 10 minutes is 10% or less, and has one end and the other end on the opposite side of the one end. The interlayer film for laminated glass is characterized in that the thickness of the laminated glass is larger than the thickness of the one end. 2. The interlayer film for laminated glass according to claim 1, wherein the interlayer film for laminated glass has a shrinkage ratio in the flow direction of 15% or less measured after the interlayer film for laminated glass is immersed in warm water at 80 ° C. for 10 minutes. A laminated glass, wherein the interlayer film for laminated glass according to claim 1 or 2 is laminated between a pair of glass plates.

Images