Interlayer for laminated glass, method for producing interlayer for laminated glass, and laminated glass

Abstract

The present invention aims to provide an interlayer film for a laminated glass that enables production of a laminated glass having high visible light transmittance even when deaeration for preliminary pressure bonding and heating for final pressure bonding are performed in parallel in a vacuum deaeration method. The present invention also aims to provide a method for producing the interlayer film for a laminated glass, and a laminated glass including the interlayer film for a laminated glass. Provided is an interlayer film for a laminated glass having a multitude of recesses on at least one surface, the surface with the recesses having a texture aspect ratio Str of 0.04 or lower as measured in conformity with ISO 25178.

Claims

1. An interlayer film for a laminated glass having a multitude of recesses on at least one surface, the surface with the recesses having a texture aspect ratio Str of 0.04 or lower as measured in conformity with ISO 25178, wherein the interlayer film has a wedge-shaped cross section, the recesses have a groove shape with a continuous bottom, and the surface with the recesses has a ten-point average roughness Rz of 10 μm or more and 50 μm or less as measured in conformity with JIS B 0601(1994).

2. The interlayer film for a laminated glass according to claim 1, wherein after heating at 100° C. for 15 minutes, the surface with the recesses has a texture aspect ratio Str of 0.08 or less as measured in conformity with ISO 25178.

3. A laminated glass comprising: a pair of glass plates; and the interlayer film for a laminated glass according to claim 1 interposed between the pair of glass plates.

4. The interlayer film for a laminated glass according to claim 1, wherein a wedge angle θ of the interlayer film having the wedge-shaped cross section is 0.1 mrad or more and 1 mrad or less.

5. A method for producing the interlayer film for a laminated glass according to claim 1, comprising: a first step of imparting fine protrusions and recesses to a surface of a resin film; and a second step of imparting recesses in the shape of engraved lines to the surface of the resin film, the resin film after the first step having an arithmetic average roughness Ra of 4 μm or less as measured in conformity with JIS B 0601(1994), in the second step, the recesses in the shape of engraved lines being imparted at a linear velocity of 10 m/min or less.

6. The method for producing the interlayer film for a laminated glass according to claim 5, wherein a product (Ra×Sm) of the arithmetic average roughness Ra of the resin film after the first step as measured in conformity with JIS B 0601(1994) and an interval Sm of the recesses is 2,500 or less.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic view illustrating an exemplary interlayer film for a laminated glass in which recesses each having a groove shape with a continuous bottom are arranged on a surface at equal intervals and adjacent recesses are arranged side by side in parallel to each other.

(2) FIG. 2 is a schematic view illustrating an exemplary interlayer film for a laminated glass in which recesses each having a groove shape with a continuous bottom are arranged on a surface at equal intervals and adjacent recesses are arranged side by side in parallel to each other.

(3) FIG. 3 is a schematic view illustrating an exemplary interlayer film for a laminated glass in which recesses each having a groove shape with a continuous bottom are arranged on a surface at unequal intervals and adjacent recesses are arranged side by side in parallel to each other.

(4) FIG. 4 is a schematic view explaining positions where parallel light transmittance Tp is measured in a laminate after preliminary pressure bonding in production of a laminated glass in examples.

DESCRIPTION OF EMBODIMENTS

(5) Embodiments of the present invention are specifically described in the following with reference to, but not limited to, examples.

Example 1

(6) (1) Preparation of Resin Film

(7) Polyvinyl alcohol having an average degree of polymerization of 1,700 was acetalized with n-butyraldehyde to give polyvinyl butyral having an acetyl group content of 1 mol %, a butyral group content of 69 mol %, and a hydroxy group content of 30 mol %. To 100 parts by mass of the obtained polyvinyl butyral were added 39 parts by mass of a plasticizer and an adhesion modifier at a magnesium concentration in the film of 50 ppm. The mixture was kneaded well with a mixing roll to give a resin composition. The plasticizer used was triethylene glycol-di-2-ethylhexanoate (3GO). The adhesion modifier used was a 50% by mass:50% by mass mixture of magnesium bis(2-ethyl butyrate) and magnesium acetate.

(8) The obtained resin composition was extruded using an extruder to give a single-layer interlayer film for a laminated glass having a thickness of 760 μm.

(9) (2) First Step

(10) Embossing rolls having a coarse main embossed pattern and a fine sub-embossed pattern were prepared by a method including forming random protrusions and recesses on the surfaces of iron rolls with an abrasive material, subjecting the iron rolls to vertical grinding, and further forming finer protrusions and recesses with a finer abrasive material on planar portions after the vertical grinding. As a first step, using the pair of embossing rolls as a device for transferring a pattern of protrusions and recesses, a random pattern of protrusions and recesses was transferred to both surfaces of the resin film.

(11) The transferring conditions employed here were a temperature of the interlayer film for a laminated glass of 80° C., a temperature of the rolls of 145° C., a linear velocity of 10 m/min, a line width of 1.5 m, and a press linear pressure of 1 to 100 kN/m.

(12) The resin film after the first step was subjected to measurements of the arithmetic average roughness Ra and the interval Sm between the recesses by methods in conformity with JIS B 0601(1994). The measurements were performed in an environment at a temperature of 23° C. and a humidity of 30 RH % under the conditions of a cut-off value of 2.5 mm, a standard length of 2.5 mm, a spare length of 2.5 mm, an evaluation length of 12.5 mm, a tip radius of the probe of 2 μm, a tip angle of 60°, and a measurement speed of 0.5 mm/s.

(13) In the case where the Sm exceeds 450 μm, the measurements may be inaccurate with a standard length of 2.5 mm. In such a case, the measurement was performed by changing the cut-off value to 8 mm or longer.

(14) (3) Second Step

(15) In the second step, a pair of rolls including a metal roll having a surface milled with a triangular oblique line-type mill and a rubber roll having a JIS hardness of 65 to 75 was used as a device for transferring a pattern of protrusions and recesses. The resin film after the first step was passed through the device for transferring a pattern of protrusions and recesses to impart, to one surface of the resin film, protrusions and recesses in which recesses each had a groove shape with a continuous bottom (shape of an engraved line) and were arranged side by side in parallel to each other at equal intervals. The transferring conditions employed here were a temperature of the resin film of 70° C., a temperature of the rolls of 140° C., a linear velocity of 10 m/min, and a press linear pressure of 1 to 100 kN/m.

(16) Subsequently, the same operations were performed on the other surface of the resin film to impart recesses each having a groove shape with a continuous bottom (shape of an engraved line).

(17) The resin film after the second step was subjected to measurements of the ten-point average roughness Rz, the arithmetic average roughness Ra, and the interval Sm between the recesses by methods in conformity with JIS B 0601(1994). The measurements were performed in a direction perpendicular to the groove shape with a continuous bottom in an environment at a temperature of 23° C. and a humidity of 30 RH % under the conditions of a cut-off value of 2.5 mm, a standard length of 2.5 mm, a spare length of 2.5 mm, an evaluation length of 12.5 mm, a tip radius of the probe of 2 μm, a tip angle of 60°, and a measurement speed of 0.5 mm/s.

(18) In the case where the Sm exceeds 450 μm, the measurements may be inaccurate with a standard length of 2.5 mm. In such a case, the measurement was performed by changing the cut-off value to 8 mm or longer.

(19) (4) Measurement of Str

(20) The Str was measured in an environment at a temperature of 23° C. and a humidity of 30 RH % by the following method.

(21) A surface of the interlayer film for a laminated glass was analyzed using a three-dimensional white light interference microscope (ContourGT-K available from Bruker AXS GmbH) in a 2 mm square field of view at an objective lens magnification of 50 times, an internal lens magnification of 0.5 times, and a resolution set to “half resolution” to obtain images. In this operation, the light quantity and threshold were set as appropriate to minimize noise in the analysis. The obtained images were subjected to planarization and noise removal processes, and coarse protrusions and recesses were removed using a Gaussian filter. Then, the Str value was calculated by a method specified in ISO 25178.

(22) Analytical software “Vision64” included in the apparatus was used in image processing. The planarization process involved the following first to third processing operations. As the first processing, the processing “Terms Removal (F-Operator)” on Analysis Toolbox was performed under the analysis condition “Tilt only (Plane Fit)”. As the second processing, the processing “Statistic Filter” was performed under the analysis conditions “Filter type: median” and “Filter size: 3”. As the third processing, the processing “data Restore” was performed by selecting the analysis condition “Legacy”, selecting Restore Edge condition, and setting Iteration condition to a value for sufficient data complement. As the noise removal processing (fourth processing), the processing “Gaussian Regression Filter” was performed under the analysis conditions “under Band pass condition, order: 0, Type: Regular, Long wavelength cutoff: 1 mm, and Short wavelength cutoff: 0.002 mm”. At this time, the advance setup was performed under initial conditions. The image data after the first processing through the fourth processing was subjected to the fifth processing “S parameters-Spatial” under the analysis condition “Angle resolution: 1 deg, Search range: From 0 to 90”. The resulting “Str” was used as the Str value.

(23) The measurement was performed on two points in the center portion of a 10 cm square sample of the interlayer film for a laminated glass. The average of the obtained values was used as the Str value. Otherwise the measurement was in conformity with ISO 25178(2012).

(24) The Str was measured on both an interlayer film for a laminated glass (before heating) not heated after production and an interlayer film for a laminated glass (after heating) heated at 100° C. for 15 minutes by the following method.

(25) A 5-mm-thick stainless steel plate and three 2.5-mm-thick clear glass plates were placed in a gear oven, and each plate was heated to a surface temperature of 100° C. Before heating to 100° C., the surface of the stainless steel plate to be in contact with the interlayer film for a laminated glass in the subsequent step was surface-treated with a silicone release agent (available from Shin-Etsu Chemical Co., Ltd., SEPA-COAT SP). After the surface temperatures of the stainless steel plate and the clear glass plates reached 100° C., the temperature of the gear oven itself was set at 100° C. On the stainless steel plate was placed the interlayer film for a laminated glass cut to a size of 10 cm×10 cm. On the interlayer film was placed a polyethylene terephthalate (PET) sheet cut to a frame shape having an inside dimensions of 7 cm×7 cm and a thickness of 50 μm. On the PET sheet were placed the three 2.5-mm-thick clear glass plates (10 cm×10 cm) heated to 100° C. Here, the interlayer film for a laminated glass and the PET sheet had been left to stand in an atmosphere at a temperature of 23° C. and a humidity of 30% for three hours before placed on, respectively, the stainless steel plate and the interlayer film for a laminated glass.

(26) The interlayer film for a laminated glass was held in the gear oven at 100° C. for 15 minutes. The interlayer film was then taken out, transferred onto a 23° C. stainless steel plate, and cooled thereon. The measurement of the Str was performed on the center portion on the surface on the stainless steel side.

Examples 2 to 13 and Comparative Examples 1 to 6

(27) An interlayer film for a laminated glass having recesses in the shape of engraved lines on the surfaces was produced as in Example 1 except that the conditions for the first step and the second step were changed as shown in Table 1 or 2. The linear velocities in the first step and the second step were the same.

(28) In Example 6 and Comparative Example 4, the die used for extruding a resin film through an extruder had a lip shape for a lip method. Specifically, a resin film having fine protrusions and recesses on the surfaces was obtained using a lip die with a lip gap of 0.7 to 1.4 mm by a method in which the temperature of the resin composition at the inlet of the die was adjusted to 150° C. to 270° C., the temperature of the lip die was adjusted to 210° C., the line speed was 10 m/min, and the variation range of the inlet pressure of the extruder within 30 seconds was controlled to 0.4% or less. In Example 6 and Comparative Example 4, this operation was performed instead of the first step.

Example 14

(29) (1) Preparation of Resin Film

(30) Polyvinyl alcohol having an average degree of polymerization of 1,700 was acetalized with n-butyraldehyde to give polyvinyl butyral having an acetyl group content of 1 mol %, a butyral group content of 69 mol %, and a hydroxy group content of 30 mol %. To 100 parts by mass of the obtained polyvinyl butyral were added 39 parts by mass of a plasticizer and an adhesion modifier at a magnesium concentration in the film of 50 ppm. The mixture was kneaded well with a mixing roll to give a resin composition. The plasticizer used was triethylene glycol-di-2-ethylhexanoate (3GO). The adhesion modifier used was a 50% by mass:50% by mass mixture of magnesium bis(2-ethyl butyrate) and magnesium acetate.

(31) The obtained resin composition was extruded through an extruder into a resin film having a wedge-shaped cross section. The obtained resin film had a minimum thickness at one end and a maximum thickness at the other end, and did not have a uniform thickness portion. The distance between the one end and the other end of the obtained resin film was 1 m.

(32) An interlayer film for a laminated glass having recesses in the shape of engraved lines on the surfaces was produced as in Example 1 except that the obtained resin film having a wedge-shaped cross section was used, and that the conditions for the first step and the second step were changed as shown in Table 3. The linear velocities in the first step and the second step were the same.

(33) The obtained interlayer film was subjected to measurements of the minimum thickness, the maximum thickness, the cross-sectional shape, and the wedge angle. The obtained values were shown in Table 3.

Examples 15 to 17 and Comparative Example 7

(34) A resin film having a wedge-shaped cross section was obtained by adjusting the extruding conditions such that the minimum thickness, the maximum thickness, the cross-sectional shape, and the wedge angle of the resulting interlayer film were as shown in Table 3.

(35) An interlayer film for a laminated glass having recesses in the shape of engraved lines on the surfaces was produced as in Example 14 except that the obtained resin film having a wedge-shaped cross section was used, and that the conditions for the first step and the second step were changed as shown in Table 3. The linear velocities in the first step and the second step were the same.

Example 18

(36) (1) Preparation of Composition for First Resin Layer

(37) Polyvinyl alcohol having an average degree of polymerization of 1,700 was acetalized with n-butyraldehyde to give polyvinyl butyral having an acetyl group content of 1 mol %, a butyral group content of 69 mol %, and a hydroxy group content of 30 mol %. To 100 parts by mass of the obtained polyvinyl butyral were added 36 parts by mass of a plasticizer and an adhesion modifier at a magnesium concentration in the film of 50 ppm. The mixture was kneaded well with a mixing roll to give resin composition for a first resin layer.

(38) The plasticizer used was triethylene glycol-di-2-ethylhexanoate (3GO). The adhesion modifier used was a 50% by mass:50% by mass mixture of magnesium bis(2-ethyl butyrate) and magnesium acetate.

(39) (2) Preparation of Composition for Second Resin Layer

(40) Polyvinyl alcohol having an average degree of polymerization of 2,300 was acetalized with n-butyraldehyde to give polyvinyl butyral having an acetyl group content of 12.5 mol %, a butyral group content of 64 mol %, and a hydroxy group content of 23.5 mol %. To 100 parts by mass of the obtained polyvinyl butyral were added 76.5 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer. The mixture was kneaded well with a mixing roll to give a resin composition for a second resin layer.

(41) (3) Preparation of Resin Film

(42) The obtained resin composition for a first resin layer and resin composition for a second resin layer were co-extruded using a co-extruder to prepare a resin film having a rectangular cross section and a laminated structure (first resin layer/second resin layer/first resin layer).

(43) An interlayer film for a laminated glass having recesses in the shape of engraved lines on the surfaces was produced as in Example 1 except that the obtained resin film having a rectangular cross section was used, and that the conditions for the first step and the second step were changed as shown in Table 4. The linear velocities in the first step and the second step were the same.

(44) The obtained interlayer film was subjected to measurements of the average thicknesses of the first resin layer, the second resin layer, and the interlayer film. The obtained values were shown in Table 4.

Examples 19 to 23 and Comparative Example 8

(45) A resin composition for a first resin layer and a resin composition for a second resin layer were prepared by changing the amounts of the polyvinyl butyral and plasticizer as shown in Table 4. A resin film having a rectangular cross section and a laminated structure (first resin layer/second resin layer/first resin layer) was prepared by adjusting the co-extruding conditions such that the average thicknesses of the first resin layer, the second resin layer, and the interlayer film were as shown in Table 4.

(46) An interlayer film for a laminated glass having recesses in the shape of engraved lines on the surfaces was produced as in Example 18 except that the obtained resin film having a rectangular cross-section was used, and that the conditions for the first step and the second step were changed as shown in Table 4. The linear velocities in the first step and the second step were the same.

Example 24

(47) (1) Preparation of Composition for First Resin Layer

(48) Polyvinyl alcohol having an average degree of polymerization of 1,700 was acetalized with n-butyraldehyde to give polyvinyl butyral having an acetyl group content of 1 mol %, a butyral group content of 69 mol %, and a hydroxy group content of 30 mol %. To 100 parts by mass of the obtained polyvinyl butyral were added 36.0 parts by mass of a plasticizer and an adhesion modifier at a magnesium concentration in the film of 50 ppm. The mixture was kneaded well with a mixing roll to provide a resin composition for a first resin layer.

(49) The plasticizer used was triethylene glycol-di-2-ethylhexanoate (3GO). The adhesion modifier used was a 50% by mass:50% by mass mixture of magnesium bis(2-ethyl butyrate) and magnesium acetate.

(50) (2) Preparation of Composition for Second Resin Layer

(51) Polyvinyl alcohol having an average degree of polymerization of 2,300 was acetalized with n-butyraldehyde to give polyvinyl butyral having an acetyl group content of 12.5 mol %, a butyral group content of 64 mol %, and a hydroxy group content of 23.5 mol %. To 100 parts by mass of the obtained polyvinyl butyral were added 76.5 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer. The mixture was kneaded well with a mixing roll to give a resin composition for a second resin layer.

(52) (3) Preparation of Resin Film

(53) The obtained resin composition for a first resin layer and resin composition for a second resin layer were co-extruded using a co-extruder to prepare a resin film having a wedge-shaped cross section and a laminated structure (first resin layer/second resin layer/first resin layer). The obtained resin film having a wedge-shaped cross section had a minimum thickness at one end and a maximum thickness at the other end, and did not have a uniform thickness portion. The distance between the one end and the other end of the obtained interlayer film having a wedge-shaped cross section was 1 m.

(54) An interlayer film for a laminated glass having recesses in the shape of engraved lines on the surfaces was produced as in Example 1 except that the obtained resin film having a wedge-shaped cross section was used, and that the conditions for the first step and the second step were changed as shown in Table 5. The linear velocities in the first step and the second step were the same.

(55) The obtained interlayer film was subjected to measurements of the minimum thickness, the maximum thickness, the cross-sectional shape, and the wedge angle of the first resin layer, the second resin layer, and the interlayer film. The obtained values were shown in Table 5.

Comparative Example 9

(56) A resin composition for a first resin layer and a resin composition for a second resin layer were prepared by changing the amounts of the polyvinyl butyral and plasticizer as shown in Table 5. A resin film having a wedge-shaped cross section and a laminated structure (first resin layer/second resin layer/first resin layer) was prepared by adjusting the co-extruding conditions such that the minimum thickness, the maximum thickness, the cross-sectional shape, and the wedge angle of the first resin layer, the second resin layer, and the interlayer film were as shown in Table 5.

(57) An interlayer film for a laminated glass having recesses in the shape of engraved lines on the surfaces was produced as in Example 24 except that the obtained resin film having a wedge-shaped cross section was used, and that the conditions for the first step and the second step were changed as shown in Table 5. The linear velocities in the first step and the second step were the same.

(58) (Evaluation)

(59) The interlayer films for a laminated glass and laminated glasses obtained in the examples and comparative examples were evaluated by the following methods.

(60) Tables 1 to 5 show the results.

(61) (1) Evaluation of Deaeration Properties (23° C. to 90° C.)

(62) For Examples 1 to 13, Comparative Examples 1 to 6, Examples 18 to 23, and Comparative Example 8, the obtained interlayer film for a laminated glass was interposed between two clear glass plates (15 cm in length×15 cm in width×2.5 mm in thickness), and the interlayer film portions protruding from the laminate were cut to prepare a laminate for evaluation.

(63) For Examples 14 to 17, Comparative Example 7, Example 24, and Comparative Example 9, the interlayer film for a laminated glass was interposed between two clear glass plates such that the one end having the minimum thickness of the interlayer film for a laminated glass was included in the laminate, and that one end of each clear glass plate was aligned with the end having the minimum thickness of the interlayer film for a laminated glass. The interlayer film portions protruding from the laminate were cut to prepare a laminate for evaluating the thinnest portion. Separately, the interlayer film for a laminated glass was interposed between two glass plates such that the one end having the maximum thickness of the interlayer film for a laminated glass was included in the laminate, and that one end of each clear glass plates was aligned with the end having the maximum thickness of the interlayer film for a laminated glass. The interlayer film portions protruding from the laminate were cut to prepare a laminate for evaluating the thickest portion.

(64) Since the interlayer films for a laminated glass having a wedge-shaped cross section produced in the examples and comparative examples of the present application had the minimum thickness at one end and the maximum thickness at the other end, the laminates for evaluating the thinnest portion and the laminates for evaluating the thickest portion were prepared by the above process. In the case of an interlayer film for a laminated glass having the minimum thickness and the maximum thickness at portions other than the ends, the laminate for evaluating the thinnest portion and the laminate for evaluating the thickest portion are preferably produced such that the portion having the minimum thickness and the portion having the maximum thickness are positioned in the middle of the clear glass plates. When it is difficult to position the portion having the minimum thickness and the portion having the maximum thickness in the middle of the clear glass plates, the laminate for evaluating the thinnest portion and the laminate for evaluating the thickest portion may be produced by the above process such that one end of each clear glass plate was aligned with one end of the interlayer film for a laminated glass.

(65) The obtained laminate for evaluation, laminate for evaluating the thinnest portion, and laminate for evaluating the thickest portion were each stored at 23° C. and 30 RH % until the surface temperature of the glass reached 23° C. The laminate was then transferred into a rubber bag. The rubber bag was connected to a vacuum suction device, and heating and depressurization were simultaneously performed to heat the laminate under reduced pressure of −600 mmHg such that the surface temperature of the glass of the laminate (preliminary pressure bonding temperature) reached 90° C. after 14 minutes. Thereafter, the laminate was cooled until the surface temperature of the glass of the laminate reached 40° C., and then the pressure was returned to atmospheric pressure to complete the preliminary pressure bonding.

(66) The preliminary pressure-bonded laminate was put in an autoclave and held under the conditions of a temperature of 140° C. and a pressure of 1,300 kPa for 10 minutes. The temperature was then lowered to 50° C. and the pressure was returned to atmospheric pressure to complete the final pressure bonding. A laminated glass was thus obtained.

(67) The parallel light transmittance Tp (%) of the laminate after the preliminarily pressure bonding in the production of the laminated glass was measured with a haze meter (HM-150 available from Murakami Color Research Laboratory) in conformity with JIS K 7105.

(68) FIG. 4 is a schematic view explaining positions where the parallel light transmittance Tp is measured. With respect to the laminate of 15 cm in length×15 cm in width, the parallel light transmittance was measured at five points (the points surrounded by dotted lines in FIG. 4): the center at which two diagonals of the laminate intersect; and four points 5.6 cm away in the diagonal direction from the apexes of the laminate. The average of the measured values was taken as the parallel light transmittance Tp.

(69) Reduction in transparency of the laminated glass is caused by defective deaeration during preliminary pressure bonding. Accordingly, the deaeration properties of the interlayer film for a laminated glass can be evaluated more precisely by measurement of the parallel light transmittance of the laminate after preliminarily pressure bonding than analysis of foaming in the laminated glass.

(70) For use in applications such as automotive windshields, the parallel light transmittance Tp needs to be at least 56%.

(71) (2) Evaluation of Deaeration Properties (50° C. to 90° C.)

(72) A laminate for evaluation, a laminate for evaluating the thinnest portion, and a laminate for evaluating the thickest portion were obtained as in the evaluation of deaeration properties (23° C. to 90° C.)

(73) The obtained laminate for evaluation, laminate for evaluating the thinnest portion, and laminate for evaluating the thickest portion were each stored in a gear oven until the surface temperature of the glass reached 50° C. The laminate was then transferred into a rubber bag preheated to 50° C., and stored therein for three minutes. The rubber bag was then connected to a vacuum suction device to perform depressurization. The laminate was heated under reduced pressure of −600 mmHg such that the surface temperature of the glass of the laminate (preliminary pressure bonding temperature) reached 90° C. after 14 minutes. Thereafter, the laminate was cooled until the surface temperature of the glass of the laminate reached 40° C., and then the pressure was returned to atmospheric pressure to complete the preliminary pressure bonding.

(74) The preliminary pressure-bonded laminate was put in an autoclave and stored under the conditions of a temperature of 140° C. and a pressure of 1,300 kPa for 10 minutes. The temperature was then lowered to 50° C. and the pressure was returned to atmospheric pressure to complete the final pressure bonding. A laminated glass was thus obtained.

(75) The parallel light transmittance Tp (%) of the laminate after the preliminary pressure bonding in the production of the laminated glass was measured in the same manner as above.

(76) TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Pro- First Impartment of pro- Roll Roll Roll Roll Roll Melt Roll Roll Roll duction Step trusions and recesses emboss- emboss- emboss- emboss- emboss- fracture emboss- emboss- emboss- ment ment ment ment ment ment ment ment First Ra (μm) 2.8 1.0 1.1 1.3 1.5 2.5 1.6 3.5 3.5 Surface Sm (μm) 460 660 650 580 650 350 650 520 520 Ra × Sm 1288 660 715 754 975 875 1040 1820 1820 Second Ra (μm) 2.9 1.1 0.9 1.5 1.4 2.4 1.5 3.6 3.6 Surface Sm (μm) 500 640 600 600 600 360 640 550 550 Ra × Sm 1450 704 540 900 840 864 960 1980 1820 Second Impartment of pro- Roll Roll Roll Roll Roll Roll Roll Roll Roll Step trusions and recesses emboss- emboss- emboss- emboss- emboss- emboss- emboss- emboss- emboss- Linear velocity ment ment ment ment ment ment ment ment ment (m/min) 10 10 10 10 10 10 10 5 8 Interlay film for First Recess Engraved Engraved Engraved Engraved Engraved Engraved Engraved Engraved Engraved laminated glass surface shape lines lines lines lines lines lines lines lines lines Rz (μm) 45 42 30 31 45 40 39 43 43 Sm (μm) 300 295 301 200 196 199 200 195 202 Str (before 0.037 0.032 0.035 0.020 0.030 0.028 0.021 0.026 0.029 heating) Str (after 0.071 0.040 0.040 0.030 0.033 0.039 0.027 0.030 0.045 heating) Δ Str 0.034 0.008 0.005 0.010 0.003 0.011 0.006 0.004 0.016 Second Recess Engraved Engraved Engraved Engraved Engraved Engraved Engraved Engraved Engraved Surface shape lines lines lines lines lines lines lines lines lines Rz (μm) 45 43 28 30 45 37 38 42 43 Sm (μm) 300 295 300 200 199 199 200 200 197 Str (before 0.034 0.030 0.037 0.022 0.030 0.030 0.022 0.028 0.030 heating) Str (after 0.071 0.039 0.042 0.032 0.033 0.039 0.028 0.031 0.045 heating) Δ Str 0.037 0.009 0.005 0.010 0.003 0.009 0.006 0.003 0.015 Evalua- Tp (23° C. to 90° C.) (%) 65 71 66 75 72 74 75 70 68 tion of Tp (50 to 90° C.) (%) 60 65 60 64 62 63 73 63 59 deaer- ation pro- perties

(77) TABLE-US-00002 TABLE 2 Example Example Example Example Comparative Comparative Comparative Comparative Comparative Comparative 10 11 12 13 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Production First Step Impartment of Roll Roll Roll Roll Roll Roll Roll Melt Roll Roll protrusions and recesses embossment embossment embossment embossment embossment embossment embossment fracture embossment embossment First Ra (μm) 3.5 0.9 1.8 1.5 6.0 7.0 6.0 8.0 6.0 3.0 Surface Sm (μm) 520 590 600 150 520 620 450 430 450 480 Ra × Sm 1820 531 1080 225 3120 4340 2700 3440 2700 1440 Second Ra (μm) 3.7 0.9 1.9 1.6 6.2 6.7 5.8 8.5 5.5 3.3 Surface Sm (μm) 450 550 550 150 510 650 470 470 450 460 Ra × Sm 1665 495 1045 240 3162 4355 2726 3995 2475 1518 Second Step Impartment of Roll Roll Roll Roll Roll Roll Roll Roll Roll Roll protrusions and recesses embossment embossment embossment embossment embossment embossment embossment embossment embossment embossment Linear velocity (m/min) 10 10 10 10 10 10 10 5 8 Interlay film for First Recess shape Engraved Engraved Engraved Engraved Engraved Engraved Engraved Engraved Engraved Engraved laminated glass surface lines lines lines lines lines lines lines lines lines lines Rz (μm) 42 35 30 38 46 42 30 40 30 38 Sm (μm) 195 194 450 190 307 400 200 200 200 195 Str (before 0.029 0.015 0.035 0.022 0.060 0.070 0.045 0.050 0.045 0.042 heating) Str (after 0.060 0.020 0.043 0.022 0.105 0.250 0.092 0.300 0.220 0.150 heating) Δ Str 0.031 0.005 0.008 0.000 0.045 0.180 0.047 0.250 0.175 0.031 Second Recess shape Engraved lines Engraved lines Engraved lines Engraved Engraved Engraved Engraved Engraved Engraved Engraved lines lines lines lines lines lines lines Surface Rz (μm) 38 38 33 36 45 40 30 40 35 35 Sm (μm) 203 192 450 190 300 410 190 200 200 203 Str (before 0.035 0.015 0.035 0.022 0.060 0.070 0.045 0.060 0.043 0.044 heating) Str (after 0.065 0.018 0.045 0.023 0.100 0.270 0.095 0.320 0.200 0.160 heating) Δ Str 0.030 0.003 0.010 0.001 0.040 0.200 0.050 0.260 0.157 0.030 Evaluation Tp (23° C. to 90° C.) (%) 66 77 65 75 64 62 64 63 66 65 of Tp (50 to 90° C.) (%) 57 75 57 73 49 38 52 40 43 48 deaeration properties

(78) TABLE-US-00003 TABLE 3 Example Example Example Example Comparative 14 15 16 17 Example 7 Production First Impartment of protrusions Roll Roll Melt Melt Roll Step and recesses embossment embossment fracture fracture embossment First Ra (μm) 1.3 1.5 2.5 2.5 6.0 Surface Sm (μm) 580 150 350 350 450 Ra × Sm 754 225 875 875 2700 Second Ra (μm) 1.5 1.6 2.4 2.4 5.8 Surface Sm (μm) 600 150 360 360 470 Ra × Sm 900 240 864 864 2726 Second Impartment of Roll Roll Roll Roll Roll Step protrusions and recesses embossment embossment embossment embossment embossment Linear velocity (m/min) 10 10 10 10 10 Interlayer Thickest First Recess Engraved Engraved Engraved Engraved Engraved film portion surface shape lines lines lines lines lines for Rz (μm) 31 36 40 40 30 laminated Sm (μm) 200 190 199 199 200 glass Str (before heating) 0.020 0.022 0.028 0.028 0.050 Str (after heating) 0.030 0.022 0.039 0.039 0.091 Δ Str 0.010 0.000 0.011 0.011 0.042 Second Recess Engraved Engraved Engraved Engraved Engraved Surface shape lines lines lines lines lines Rz (μm) 30 36 37 37 30 Sm (μm) 200 190 199 199 190 Str (before heating) 0.022 0.022 0.030 0.030 0.050 Str (after heating) 0.032 0.023 0.039 0.039 0.095 Str (after heating) 0.010 0.001 0.009 0.009 0.045 Thinnest First Recess Engraved Engraved Engraved Engraved Engraved portion surface shape lines lines lines lines lines Rz (μm) 31 38 40 48 30 Sm (μm) 200 190 199 200 200 Str (before heating) 0.020 0.022 0.028 0.025 0.050 Str (after heating) 0.030 0.022 0.039 0.030 0.092 Δ Str 0.010 0.000 0.011 0.005 0.042 Second Recess Engraved Engraved Engraved Engraved Engraved Surface shape lines lines lines lines lines Rz (μm) 30 36 37 37 30 Sm (μm) 200 190 199 199 190 Str (before heating) 0.022 0.022 0.030 0.030 0.050 Str (after heating) 0.032 0.023 0.039 0.039 0.095 Δ Str 0.010 0.001 0.009 0.009 0.045 Thickness Minimum [um] 800 830 780 900 800 thickness Maxium [um] 1200 1600 1250 1230 1200 thickness Cross- [-] Wedge Wedge Wedge Wedge Wedge sectional shape shape shape shape shape shape Width mm 1000 1000 1000 1000 1000 Wedge [mrad] 0.40 0.77 0.47 0.33 0.40 angle Evaluation Thickest Tp (23° C. to 90° C.) (%) 72 75 69 73 60 of portion Tp (50 to 90° C.) (%) 60 71 58 68 49 deaeration Thinnest Tp (23° C. to 90° C.) (%) 77 78 74 74 64 properties portion Tp (50 to 90° C.) (%) 65 74 62 62 52

(79) TABLE-US-00004 TABLE 4 Comparative Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 Example 8 First Polyvinyl Butyral group content [mol %] 69 68.5 69.9 69 69 69 69 resin butyral Hydroxy group content [mol %] 30 31 29 30 30 30 30 layer resin Acetyl group content [mol %] 1 0.5 1.1 1 1 1 1 Amount [phr] 100 100 100 100 100 100 100 Plasticizer Type [-] 3GO 3GO 3GO 3GO 3GO 3GO 3GO Amount [phr] 36.0 36.0 39.0 36.0 36.0 36.0 36.0 Structure Average Thickness [μm] 350 350 345 350 350 350 350 Cross-sectional shape [-] Rectangular Rectangular Rectangular Rectangular Rectangular Rectangular Rectangular shape shape shape shape shape shape shape Second Polyvinyl Butyral group content [mol %] 64 67 77.8 69 69 64 64 resin butyral Hydroxy group content [mol %] 23.5 25.0 20.7 18.0 18.0 23.5 23.5 layer resin Acetyl group content [mol %] 12.5 8 1.5 13 13 12.5 12.5 Amount [phr] 100 100 100 100 100 100 100 Plasticizer Type [-] 3GO 3GO 3GO 3GO 3GO 3GO 3GO Amount [phr] 76.5 75.0 79.2 78.0 78.0 76.5 76.5 Structure Average Thickness [μm] 100 110 120 100 100 100 100 Cross-sectional shape [-] Rectangular shape Rectangular Rectangular Rectangular Rectangular Rectangular Rectangular Production First step Impartment of protrusions and recesses Roll embossment Roll embossment Roll embossment Roll embossment Roll embossment Melt fracture Roll embossment First surface Ra (μm) 1.4 1.4 1.4 1.8 1.8 2.7 7.2 Sm (μm) 570 580 600 610 610 340 620 Ra × Sm 798 812 840 1098 1098 918 4464 Second surface Ra (μm) 1.6 1.6 1.6 2.0 2.0 2.5 6.9 Sm (μm) 550 550 540 550 550 360 650 Ra × Sm 880 880 864 1100 1100 900 4485 Second Impartment of protrusions and recesses Roll Roll Roll Roll Roll Roll Roll Step Linear velocity (m/min) embossment embossment embossment embossment embossment embossment embossment 10 10 10 10 10 10 10 Interlayer film for First Recess Engraved Engraved Engraved Engraved Engraved Engraved Engraved laminated glass surface shape lines lines lines lines lines lines lines Rz (μm) 31 31 31 30 37 39 43 Sm (μm) 200 200 199 450 192 199 402 Str (before heating) 0.021 0.021 0.020 0.036 0.022 0.028 0.072 Str (after heating) 0.031 0.030 0.030 0.043 0.022 0.040 0.255 Δ Str 0.010 0.009 0.010 0.007 0.000 .012 0.183 Second Recess Engraved Engraved Engraved Engraved Engraved Engraved Engraved Surface shape lines lines lines lines lines lines lines Rz (μm) 30 30 30 33 38 39 41 Sm (μm) 202 200 195 450 190 202 405 Str (before heating) 0.022 0.021 0.022 0.036 0.021 0.030 0.075 Str (after heating) 0.032 0.031 0.032 0.046 0.022 0.039 0.278 Δ Str 0.010 0.010 0.010 0.010 0.001 0.009 0.203 Structure [-] First resin First resin First resin First resin First resin First resin First resin layer/second layer/second layer/second layer/second layer/second layer/second layer/second resin layer/first resin layer/first resin layer/first resin layer/first resin layer/first resin layer/first resin layer/first resin layer resin layer resin layer resin layer resin layer resin layer resin layer Cross-sectional shape [-] Rectangular Rectangular Rectangular Rectangular Rectangular Rectangular Rectangular shape shape shape shape shape shape shape Evaluation of Tp (23° C. to 90° C.) (%) 77 76 71 65 78 74 62 deaeration Tp (50 to 90° C.) (%) 65 66 51 57 74 62 38 properties

(80) TABLE-US-00005 TABLE 5 Comparative Example 24 Example 9 First resin Polyvinyl Butyral group content [mol %] 69 69.9 layer butyral Hydroxy group content [mol %] 30 29 resin Acetyl group content [mol %] 1 1.1 Amount [phr] 100.0 100.0 Plasticizer Type [—] 3GO 3GO Amount [phr] 36.0 39.0 Structure Minimum thickness [μm] 350 345 Maximum thickness [μm] 610 605 Cross-sectional shape [—] Wedge Wedge Second Polyvinyl Butyral group content [mol %] 64 77.8 resin layer butyral Hydroxy group content [mol %] 23.5 20.7 resin Acetyl group content [mol %] 12.5 1.5 Amount [phr] 100 100 Plasticizer Type [—] 3GO 3GO Amount [phr] 76.5 79.2 Structure Minimum thickness [μm] 100 110 Maximum thickness [μm] 180 190 Cross-sectional shape [—] Wedge Wedge Production First Impartment of protrusions and recesses Roll embossment Roll embossment step First surface Ra (μm) 1.3 6.0 Sm (μm) 580.0 450 Ra × Sm 755 2700 Second surface Ra (μm) 2 5.8 Sm (μm) 600.0 470 Ra × Sm 900 2726 Second Impartment of protrusions and recesses Roll embossment Roll embossment step Linear velocity (m/min) 10 10 Interlayer Thickest First surface Recess shape Engraved lines Engraved lines film for portion Rz (μm) 31 30 laminated Sm (μm) 200 200 glass Str (before heating) 0.020 0.050 Str (after heating) 0.030 0.092 ΔStr 0.010 0.042 Second surface Recess shape Engraved lines Engraved lines Rz (μm) 30 30 Sm (μm) 200 190 Str (before heating) 0.022 0.050 Str (after heating) 0.032 0.095 ΔStr 0.010 0.045 Thinnest First surface Recess shape Engraved lines Engraved lines portion Rz (μm) 31 30 Sm (μm) 200 200 Str (before heating) 0.020 0.050 Str (after heating) 0.030 0.092 ΔStr 0.010 0.042 Second surface Recess shape Engraved lines Engraved lines Rz (μm) 30 30 Sm (μm) 200 190 Str (before heating) 0.022 0.050 Str (after heating) 0.032 0.095 ΔStr 0.010 0.045 Thickness Minimum thickness [—] 800 800 Maximum thickness [—] 1400 1400 Cross-sectional shape [—] Wedge Wedge Width mm 1000 1000 Structure [—] First resin First resin layer/second resin layer/second resin layer/first resin layer layer/first resin layer Wedge angle [mrad] 0.60 0.60 Evaluation Thickest Tp (23° C. to 90° C.) (%) 70 59 of portion Tp (50 to 90° C.) (%) 60 48 deaeration Thinnest Tp (23° C. to 90° C.) (%) 75 64 properties portion Tp (50 to 90° C.) (%) 64 52

INDUSTRIAL APPLICABILITY

(81) The present invention can provide an interlayer film for a laminated glass that enables production of a laminated glass having high visible light transmittance even when deaeration for preliminary pressure bonding and heating for final pressure bonding are performed in parallel in a vacuum deaeration method. The present invention also can provide a method for producing the interlayer film for a laminated glass and a laminated glass including the interlayer film for a laminated glass.

REFERENCE SIGNS LIST

(82) 1 recess 2 recess 3 recess 4 laminate after preliminary pressure bonding in production of laminated glass A interval between recess 1 and recess 2 B interval between recess 1 and recess 3