Interlayer for laminated glass, laminated glass, production method for embossing roll, and production method for interlayer for laminated glass

Abstract

The present invention aims to provide an interlayer film for a laminated glass having recesses in the shape of engraved lines on both surfaces to exhibit excellent deaeration properties in production of a laminated glass and suppressing formation of a moire pattern when unwound from a rolled body thereof. The present invention also aims to provide a laminated glass including the interlayer film for a laminated glass, a method for producing an embossing roll suitably used for production of the interlayer film for a laminated glass, and a method for producing the interlayer film for a laminated glass. The present invention relates to an interlayer film for a laminated glass, having a large number of recesses on both surfaces, the recesses each having a groove shape with a continuous bottom and being regularly adjacent and parallel to each other, the interlayer film having a glossiness on a surface with the large number of recesses measured in conformity with JIS Z 8741-1997 of higher than 3% or a haze value measured in conformity with JIS K 7105-1981 of 87% or lower.

Claims

1. An interlayer film for a laminated glass, having recesses on both surfaces, the recesses each having a groove shape with a continuous bottom and being regularly adjacent and parallel to each other, the interlayer film having a glossiness on a surface with the recesses measured in conformity with JIS Z 8741-1997 of higher than 3% and a haze value measured in conformity with JIS K 7105-1981 of 87% or lower, wherein an interval Sm between the recesses each having a groove shape with a continuous bottom is 350 m or less, and wherein the interlayer film includes a resin layer comprising polyvinyl acetal and a plasticizer.

2. 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.

3. A method for producing the interlayer film for a laminated glass according to claim 1, said method comprising providing recesses on at least one surface of an interlayer film for a laminated glass by an embossing roll method using an embossing roll produced by a method comprising: an embossing roll production step 1 of forming protrusions and recesses on a metal roll by blasting with an abrasive material; an embossing roll production step 2 of grinding a protion of each protrusion on the metal roll provided with the protrusions and recesses into a flat surface portion; and an embossing roll production step 3 of forming protrusions and recesses by blasting with an abrasive material finer than the abrasive material used in the embossing roll production step 1.

4. A method for producing the interlayer film for a laminated glass according to claim 1, the method being intended to form recesses on at least one surface of an interlayer film for a laminated glass by an embossing method in which melt fracture phenomena are controlled, the method comprising the step of: extruding a resin composition from a die to form an interlayer film for a laminated glass; and cooling the extruded interlayer film for a laminated glass in a cooling water tank, a distance between the die and the cooling water tank being adjusted to 250 mm or shorter in the cooling.

5. A method for producing the interlayer film for a laminated glass according to claim 1, said method comprising providing recesses on at least one surface of an interlayer film for a laminated glass by an embossing roll method using an embossing roll produced by a method comprising: an embossing roll production step 1 of forming protrusions and recesses on a metal roll by blasting with an abrasive material; an embossing roll production step 2 of grinding a portion of each protrusion on the metal roll provided with the protrusions and recesses into a flat surface portion; and an embossing rill production step 3 of forming protrusions and recesses by blasting with an abrasive material finer than the abrasive material used in the embossing roll production step 1, wherein the abrasive material used in the embossing roll production step 3 has a grain diameter at a cumulative height of 3% in conformity with JIS R6001 (1998) of 11 m or more.

6. The interlayer film for a laminated glass according to claim 1, having a haze value measured in conformity with JIS K 7105-1981 of 72% to 87%.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows views schematically explaining a cause of a moire pattern formed when an interlayer film for a laminated glass having recesses in the shape of engraved lines is unwound from a rolled body thereof.

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

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

(4) FIG. 4 shows a view schematically illustrating an exemplary interlayer film for a laminated glass in which recesses each having a groove shape with a continuous bottom are arranged on the surface at unequal intervals and adjacent recesses are parallel to each other.

(5) FIG. 5 shows views schematically explaining the radius of rotation R of a protrusion.

(6) FIG. 6 is a view schematically explaining the intersection angle .

DESCRIPTION OF EMBODIMENTS

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

Example 1

(1) Preparation of a Resin Composition

(8) Polyvinyl alcohol having an average degree of polymerization of 1,700 was acetalized with n-butyraldehyde to give polyvinyl butyral (acetyl group content: 1 mol %, butyral group content: 69 mol %, hydroxy group content: 30 mol %). To 100 parts by mass of the polyvinyl butyral was added 40 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer, and kneaded well with a mixing roll to give a resin composition.

(2) Production of an Interlayer Film for a Laminated Glass

(9) The obtained resin composition was extruded from an extruder to form an interlayer film for a laminated glass with a uniform thickness.

(3) Formation of Fine Protrusions and Recesses in the First Step

(10) According to Production Example 1, fine protrusions and recesses were formed on both surfaces (first surface and second surface) of the interlayer film for a laminated glass to adjust the glossiness of the surface.

(11) Here, an embossing roll produced by the following method was used.

(12) As an embossing roll production step 1, blasting was performed on the surface of a metal roll using a #36 abrasive material made of aluminum oxide at a discharge pressure of 5010.sup.4 Pa. After the embossing roll production step 1, the ten-point average roughness Rz of the roll surface measured in conformity with JIS B-0601 (1994) was 65 m.

(13) Next, as an embossing roll production step 2, partial grinding was performed using a #400 to #1000 grinding stone. After the embossing roll production step 2, the ten-point average roughness Rz of the roll surface measured in conformity with JIS B-0601 (1994) was 40 m.

(14) Then, as an embossing roll production step 3, blasting was performed using #320 abrasive material made of aluminum oxide at a discharge pressure of 5010.sup.4 Pa, thereby preparing an embossing roll.

(15) A pair of thus prepared embossing rolls was used as a device for transferring a pattern of protrusions and recesses to form fine protrusions and recesses on both surfaces of the obtained interlayer film for a laminated glass. 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 linear pressure of 1 to 100 kN/m.

(16) The ten-point average roughness (Rz) of the film surface after the formation of fine protrusions and recesses measured in conformity with JIS B-0601 was 12 m. The obtained interlayer film had an average thickness of 760 m.

(4) Formation of Recesses in the Shape of Engraved Lines by Second Step

(17) To the surface of the interlayer film for a laminated glass after the first step was provided protrusions and recesses each having a groove shape with a continuous bottom by the following procedure. A pair of rolls including a metal roll having a surface processed with a triangular oblique line-type mill and a rubber roll having a JIS hardness of 45 to 75 was used as a device for transferring a pattern of protrusions and recesses. The interlayer film for a laminated glass after the first step was passed through the device for transferring a pattern of protrusions and recesses, thereby forming protrusions and recesses where recesses each having a groove shape with a continuous bottom are parallel to each other at equal intervals on the first surface of the interlayer film for a laminated glass. The transferring conditions employed here were a temperature of the interlayer film for a laminated glass of 70 C., a temperature of the rolls of 140 C., a linear velocity of 10 m/min, and a linear pressure to 1 to 100 kN/m for producing the desired roughness.

(18) Then, the same operations were performed on the second surface of the interlayer film for a laminated glass to form recesses each having a groove shape with a continuous bottom. At that time, the intersection angle formed between the recesses each having a groove shape (shape of an engraved line) with a continuous bottom on the first surface and the recesses each having a groove shape (shape of an engraved line) with a continuous bottom on the second surface was set to 20.

(5) Measurement of Protrusions and Recesses on the First Surface and the Second Surface

(5-1) Glossiness Measurement

(19) The glossiness was measured using a gloss meter (GM-26PRO available from Murakami Color Research Laboratory) by the method of measurement 2 described in JIS Z 8741-1997. The interlayer film for a laminated glass was left to stand on a sample table, and the glossiness was measured while the interlayer film for a laminated glass was rotated so that the angle of the groove shape of each recess relative to the irradiation direction of a light source was changed. Here, the minimum glossiness was taken as the glossiness of the interlayer film for a laminated glass of the present invention.

(5-2) Rz Value Measurement

(20) The ten-point average roughness (Rz) on both surfaces of the obtained interlayer film for a laminated glass was measured by the method in conformity with JIS B-0601 (1994) using Surfcorder SE300 available from Kosaka Laboratory Ltd. The measurement was performed using a stylus profilometer at a cut-off value of 2.5 mm, a standard length of 2.5 mm, an evaluation length of 12.5 mm, and a measurement rate of 0.5 mm/s, with a stylus having a tip radius of 2 m and a tip angle of 60. The measurement environment was 23 C. and 30 RH %. The stylus was moved in a direction perpendicular to the groove direction of engraved lines.

(5-3) Sm Measurement

(21) The Sm values of the first surface and second surface of the obtained interlayer film for a laminated glass were measured using a Surfcorder SE300 available from Kosaka Laboratory Ltd. The measurement was performed using a stylus profilometer at a cut-off value of 2.5 mm, a standard length of 2.5 mm, an evaluation length of 12.5 mm, and a measurement rate of 0.5 mm/s, with a stylus having a tip radius of 2 m and a tip angle of 60. The measurement environment was 23 C. and 30 RH %. The stylus was moved in a direction perpendicular to the direction of grooves in the shape of engraved lines.

(5-4) Haze Value Measurement

(22) The haze value was measured by the method described in JIS K 7105-1981 with a haze and transmittance meter (HM-150 available from Murakami Color Research Laboratory). Here the interlayer film for a laminated glass was set in such a manner that the first surface was on the light source side.

Examples 2 to 6

(23) An interlayer film for a laminated glass was obtained in the same manner as in Example 1, except that the conditions for forming recesses in the shape of engraved lines in the second step were changed.

Comparative Example 1

(24) An interlayer film for a laminated glass was obtained in the same manner as in Example 1, except that the grain size of the abrasive material used in the embossing roll production step 3 in which an embossing roll for forming the first shape was produced was changed to #800.

Example 7

(1) Preparation of a Resin Composition

(25) Polyvinyl alcohol having an average degree of polymerization of 1,700 was acetalized with n-butyraldehyde to give polyvinyl butyral (acetyl group content: 1 mol %, butyral group content: 69 mol %, hydroxy group content: 30 mol %). To 100 parts by mass of the polyvinyl butyral were added 40 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer, and the mixture was mixed well with a mixing roll to give a resin composition.

(2) Production of an Interlayer Film for a Laminated Glass and Formation of Fine Protrusions and Recesses

(26) According to Production. Example 2, concurrently with the formation of an interlayer film for a laminated glass, fine protrusions and recesses were formed on both surfaces of the interlayer film for a laminated glass.

(27) Specifically, an interlayer film for a laminated glass was formed under the conditions including the extrusion amount per die width of 440 kg/hr.Math.m, the surface temperature of the film immediately after extrusion from the die of 200 C., the resin pressure at the die inlet of 80 kgf/cm.sup.2, and the water temperature in the water tank for cooling the film of 20 C. to 30 C. in the embossing method in which melt fracture phenomena are controlled, and at the same time, fine protrusions and recesses were formed on both surfaces of the interlayer film for a laminated glass. In the above step, the distance from the die to the surface of the cooling water tank was set to 100 mm.

(28) The obtained interlayer film for a laminated glass had a thickness of 760 m. The Rz value measured by the same method as in Example 1 after formation of the fine protrusions and recesses was 18 m.

(29) The obtained interlayer film for a laminated glass with fine protrusions and recesses was subjected to the second step in the same manner as in Example 1, except that the conditions for forming recesses in the shape of engraved lines were changed. An interlayer film for a laminated glass was thus obtained.

Examples 8 to 11

(30) An interlayer film for a laminated glass was obtained in the same manner as in Example 7, except that conditions for forming recesses in the shape of engraved lines were changed.

Comparative Example 2

(31) An interlayer film for a laminated glass was obtained in the same manner as in Example 7, except that the distance from the die to the surface of the cooling water tank was changed to 200 mm in the embossing method in which melt fracture phenomena are controlled.

Examples 12 to 14

(32) An interlayer film for a laminated glass was obtained in the same manner as in Example 1, except that the polyvinyl butyral used had a composition as shown in Table 2 and the conditions for forming the recesses in the shape of engraved lines in the second step were changed.

Comparative Example 3

(33) An interlayer film for a laminated glass was obtained in the same manner as in Comparative Example 1, except that the polyvinyl butyral used had a composition as shown in Table 2 and the conditions for forming the recesses in the shape of engraved lines in the second step were changed.

Comparative Example 4

(34) An interlayer film for a laminated glass was obtained in the same manner as in Comparative Example 2, except that the polyvinyl butyral used had a composition as shown in Table 2 and the conditions for forming the recesses in the shape of engraved lines were changed.

Evaluation

(35) Formation of a moire pattern in each of the interlayer films for a laminated glass obtained in Examples 1 to 14 and Comparative Examples 1 to 4 was evaluated by the following method. Tables 1 and 2 show the results.

(36) The interlayer film for a laminated glass obtained in each of the examples and comparative examples was cut to prepare a test sample with a size of 50 mm in length and 50 mm in width. Three pieces of thus obtained test samples were stacked to give a laminate. The laminate was left to stand on a 1.5-mm-thick PVB sheet that was placed on an even glass plate for the purpose of allowing uniform application of a load, with a release paper interposed between the laminate and the PVB sheet. Here, the release paper was prepared by coating base paper with silicone as releasing treatment. Then, a glass plate of 6-kg weight was placed on the laminate with a release paper interposed therebetween. The release paper was prepared by coating base paper with silicone as releasing treatment. After standing at 23 C. for 72 hours, the interlayer film for a laminated glass placed in the middle of the laminate was taken out and subjected to a moire test within three minutes after being taken out.

(37) The moire test was performed as follows. The interlayer film for a laminated glass was set at a position of 1 m from a lamp, and 20 evaluators visually observed the interlayer film from a position on the opposite side of the lamp across the interlayer film and obliquely at an angle of 45. The number of people who noticed a moire pattern and the number of people who felt that the moire pattern was unpleasant were counted.

(38) TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 6 7 8 9 10 Compositon Polyvinyl Average degree of 1700 1700 1700 1700 1700 1700 1700 1700 1700 1700 of interlayer butyral resin polymerization of PVA film Degree of butyralization mol % 69 69 69 69 69 69 69 69 69 69 Degree of acetylation mol % 1 1 1 1 1 1 1 1 1 1 Hydroxy group content mol % 30 30 30 30 30 30 30 30 30 30 Amount Parts by 100 100 100 100 100 100 100 100 100 100 mass Plasticizer Type 3GO 3GO 3GO 3GO 3GO 3GO 3GO 3GO 3GO 3GO Amount Parts by 40 40 40 40 40 40 40 40 40 40 mass Method of Melt fracture Distance from die to mm 100 100 100 100 providing fine method surface of water tank protrusions Embossing Abrasive material used Mesh #320 #320 #320 #320 #320 #320 and recesses roll method in embossing roll production step 3 Protrusions First surface Glossiness % 4.2 4.9 8.0 4.9 6.5 15.4 10.0 10.5 3.9 7.0 and recesses Rz m 44 35 25 35 37 50 35 35 45 49 on the surface Sm m 200 200 195 200 260 395 203 201 201 220 Second Glossiness % 4 4.5 8 4.6 5.4 14.2 11.2 11.9 3.5 7 surface Rz m 42 36 27 36 38 45 34 34 43 45 Sm m 185 185 186 185 250 390 201 201 201 215 Intersection angle of recesses 20 20 20 90 90 20 90 20 20 45 Haze value % 84.4 82.9 80.0 82.8 82.5 72.0 83.2 83.3 86.2 83.3 Evaluation Moire test Number of people who noticed 13 10 8 9 7 6 14 15 17 8 moire pattern Number of people who felt that 2 0 0 0 0 0 2 3 4 0 moire pattern was unpleasant

(39) TABLE-US-00002 TABLE 2 Example Comparative Example 11 12 13 14 1 2 3 4 Compositon Polyvinyl Average degree of 1700 1700 1700 1700 1700 1700 1700 1700 of interlayer butyral resin polymerization of PVA film Degree of butyralization mol % 69 69 69.9 68.4 69 69 69.9 68.4 Degree of acetylation mol % 1 1 1.1 0.7 1 1 1.1 0.7 Hydroxy group content mol % 30 30 29 30.9 30 30 29 30.9 Amount Parts by 100 100 100 100 100 100 100 100 mass Plasticizer Type 3GO 3GO 3GO 3GO 3GO 3GO 3GO 3GO Amount Parts by 40 40 40 40 40 40 40 40 mass Method of Melt fracture Distance from die to mm 100 200 200 providing fine method surface of water tank protrusions Embossing Abrasive material used Mesh #320 #320 #320 #800 #800 and recesses roll method in embossing roll production step 3 Protrusions First surface Glossiness % 13.9 3.5 4.4 5.0 3.0 2.9 2.8 2.9 and recesses Rz m 43 48 42 35 50 53 52 51 on the surface Sm m 350 190 199 195 200 195 200 195 Second Glossiness % 15 3.4 4.4 4.6 3 2.9 2.5 2.9 surface Rz m 50 48 40 35 52 51 54 51 Sm m 350 175 195 180 198 203 195 186 Intersection angle of recesses 20 20 20 20 20 20 20 20 Haze value % 79.0 86.5 83.0 82.5 87.8 88.1 88.0 87.9 Evaluation Moire test Number of people who noticed 2 20 13 9 20 20 20 20 moire pattern Number of people who felt that 0 8 1 0 18 17 18 14 moire pattern was unpleasant

Example 15

Preparation of a Resin Composition for a Protective Layer

(40) Polyvinyl alcohol having an average degree of polymerization of 1,700 was acetalized with n-butyraldehyde to give polyvinyl butyral (acetyl group content: 1 mol %, butyral group content: 69 mol %, hydroxy group content: 30 mol %). To 100 parts by mass of the polyvinyl butyral was added 36 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer, and the mixture was sufficiently kneaded with a mixing roll to prepare a resin composition for a protective layer.

(41) (Preparation of a Resin Composition for an Intermediate Layer)

(42) Polyvinyl alcohol having an average degree of polymerization of 3,000 was acetalized with n-butyraldehyde to give polyvinyl butyral (acetyl group content: 12.5 mol %, butyral group content: 64.2 mol %, hydroxy group content: 23.3 mol %). To 100 parts by mass of the polyvinyl butyral was added 76.5 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer, and the mixture was sufficiently kneaded with a mixing roll to prepare a resin composition for an intermediate layer.

Production of an Interlayer Film for a Laminated Glass

(43) The obtained resin composition for an intermediate layer and resin composition for a protective layer were co-extruded using a co-extruder to form an interlayer film for a laminated glass having a triple layer structure including a first protective layer made of the resin composition for a protective layer, an intermediate layer made of the resin composition for an intermediate layer, and a second protective layer made of the resin composition for a protective layer, stacked in the stated order. The extrusion conditions were set such that the first and second protective layers each had a thickness of 350 m and the intermediate layer had a thickness of 100 m in an interlayer film for a laminated glass to be obtained after formation of protrusions and recesses.

(44) Then, the protrusions and recesses were formed on the interlayer film for a laminated glass in the same manner as in Example 1, except that the type of the blasting material used in the embossing roll production step 3 in which the embossing roll for forming the first shape was produced was changed and the pressure upon transferring the pattern of protrusions and recesses was adjusted so that the desired Rz value was achieved. The protrusions and recesses on the both surfaces were measured.

Example 16

Production of an Interlayer Film for a Laminated Glass and Formation of Fine Protrusions and Recesses

(45) A resin composition for an intermediate layer and a resin composition for a protective layer were obtained in the same manner as in Example 15. The obtained resin composition for, intermediates layer and resin composition for a protective layer were coextruded using a co-extruder to form an interlayer film for a laminated glass having a triple layer structure including a first protective layer made of the resin composition for a protective layer, an intermediate layer made of the resin composition for an intermediate layer, and a second protective layer made of the resin composition for a protective layer, stacked in the stated order. In that process, according to Production Example 2, the first shape was provided concurrently with the formation of the interlayer film for a laminated glass. Specifically, in the embossing method in which melt fracture phenomena are controlled, an interlayer film for a laminated glass was formed under the conditions including the extrusion amount per width of the die of 440 kg/hr.Math.m, the surface temperature of the film immediately after extrusion from the die of 200 C., the resin pressure at the die inlet of 80 kgf/cm.sup.2, and the water temperature in the water tank for cooling the film of 20 C. to 30 C. At the same time, fine protrusions and recesses were formed on both surfaces of the interlayer film for a laminated glass. In the above step, the distance from the die to the surface of the cooling water tank was set to 100 mm. The obtained interlayer film for a laminated glass with fine protrusions and recesses was subjected to the second step in the same manner as in Example 1, except that the conditions for forming the recesses in the shape of engraved lines were changed. An interlayer film for a laminated glass was thus obtained. The first protective layer and second protective layer of the obtained interlayer film for a laminated glass each had a thickness of 350 m and the intermediate layer had a thickness of 100 m.

Examples 17 to 21

(46) An interlayer film for a laminated glass was produced in the same manner as in Example 15, except that the polyvinyl butyral used had a composition as shown in Table 3 or 4 and that the type of the blasting material used in the embossing roll production step 3 in which an embossing roll for forming the first shape was produced and the pressure upon transferring of the pattern of protrusions and recesses were adjusted so that the desired Rz value was achieved. The protrusions and recesses on each surface of the obtained interlayer film for a laminated glass were measured.

Comparative Example 5

(47) An interlayer film for a laminated glass was obtained in the same manner as in Example 15, except that the grain size of the abrasive material used in the embossing roll production step 3 in which an embossing roll for forming the first shape was produced was changed to #800.

Comparative Example 6

(48) An interlayer film for a laminated glass was obtained in the same manner as in Example 16, except that the distance from the die to the surface of the cooling water tank in the embossing method in which melt fracture phenomena are controlled was changed to 200 mm.

Evaluation

(49) Formation of a moire pattern in each of the interlayer films for a laminated glass obtained in Examples 15 to 21 and Comparative Examples 5 and 6 was evaluated by the same method as described above. Tables 3 and 4 show the results.

(50) TABLE-US-00003 TABLE 3 Example 15 16 17 18 19 First and Polyvinyl Average degree of 1700 1700 1700 1700 1700 second butyral polymerization of PVA protective resin Degree of butyralization mol % 69 69 69 69.9 69.9 layers Degree of acetylation mol % 1 1 1 1.1 1.1 Hydroxy group content mol % 30 30 30 29 29 Amount Parts by 100 100 100 100 100 mass Plasticizer Type 3GO 3GO 3GO 3GO 3GO Amount Parts by 36 36 36 39 39 mass Structure Thickness m 350 350 350 360 350 Intermediate Polyvinyl Average degree of 3000 3000 1700 2300 3000 layer butyral polymerization of PVA resin Degree of butyralization mol % 64.2 64.2 64.2 77.8 77.8 Degree of acetylation mol % 12.5 12.5 12.5 1.5 1.5 Hydroxy group content mol % 23.3 23.3 23.3 20.7 20.7 Amount Parts by 100 100 100 100 100 mass Plasticizer Type 3GO 3GO 3GO 3GO 3GO Amount Parts by 76.5 76.5 76.5 79 79 mass Structure Thickness m 100 100 100 100 100 Whole Structure Structure First First First First First interlayer protective protective protective protective protective film layer/ layer/ layer/ layer/ layer/ intermediate intermediate intermediate intermediate intermediate layer/second layer/second layer/second layer/second layer/second protective protective protective protective protective layer layer layer layer layer Thickness m 800 800 800 800 800 Method of Melt-fracture Distance from die to mm 100 providing fine method surface of water tank protrusions Embossing Abrasive material in Mesh #320 #320 #320 #320 and recesses roll method embossing roll production step 3 Protrusions First Glossiness % 4.2 9.8 4.1 4,5 4.3 and recesses surface Rz m 43 34 4.2 42 43 on surface Sm m 200 200 201 204 202 Second Glossiness % 4.3 10.6 4.4 4.5 4.4 surface Rz m 40 37 41 42 42 Sm m 195 198 194 204 200 Intersection angle of recesses 20 90 20 20 20 Haze value % 84.6 83.4 84.5 83.5 83.4 Evaluation Moire test Number of people who noticed 14 16 14 13 13 moire pattern Number of people who felt that 2 2 2 1 1 moire pattern was unpleasant

(51) TABLE-US-00004 TABLE 4 Example Comparative Example 20 21 5 6 First and Polyvinyl Average degree of 1700 1700 1700 1700 second butyral polymerization of PVA protective resin Degree of butyralization mol % 68.5 68.5 69 69 layers Degree of acetylation mol % 0.5 0.5 1 1 Hydroxy group content mol % 31 31 30 30 Amount Parts by 100 100 100 100 mass Plasticizer Type 3GO 3GO 3GO 3GO Amount Parts by 36 36 36 36 mass Structure Thickness m 350 350 350 350 Intermediate Polyvinyl Average degree of 3000 1700 3000 3000 layer butyral polymerization of PVA 67 67 64.2 64.2 resin Degree of butyralization mol % Degree of acetylation mol % 8 8 12.5 12.5 Hydroxy group content mol % 25 25 23.3 23.3 Amount Parts by 100 100 100 100 mass Plasticizer Type 3GO 3GO 3GO 3GO Amount Parts by 75 75 76.5 76.5 mass Structure Thickness m 100 100 100 100 Whole Structure Structure First First First First interlayer protective protective protective protective film layer/ layer/ layer/ layer/ intermediate intermediate intermediate intermediate layer/second layer/second layer/second layer/second protective protective protective protective layer layer layer layer Thickness m 800 800 800 800 Method of Melt-fracture Distance from die to mm 200 providing fine method surface of water tank protrusions Embossing Abrasive material in Mesh #320 #320 #320 #800 and recesses roll method embossing roll production step 3 Protrusions First Glossiness % 5.5 5.5 3.0 2.9 and recesses surface Rz m 33 34 50 53 on surface Sm m 190 188 200 195 Second Glossiness % 5.3 5.2 2.9 2.9 surface Rz m 35 34 51 53 Sm m 185 180 198 203 Intersection angle of recesses 20 20 20 20 Haze value % 82.5 82.5 87.5 88.1 Evaluation Moire test Number of people who noticed 8 8 20 20 moire pattern Number of people who felt that 0 0 16 18 moire pattern was unpleasant

INDUSTRIAL APPLICABILITY

(52) The present invention can provide an interlayer film for a laminated glass having recesses in the shape of engraved lines on both surfaces to exhibit excellent deaeration properties in production of a laminated glass and suppressing formation of a moire pattern when unwound from a rolled body thereof. The present invention can also provide a laminated glass including the interlayer film for a laminated glass, a method for producing an embossing roll suitably used for production of the interlayer film for a laminated glass, and a method for producing the interlayer film for a laminated glass.

REFERENCE SIGNS LIST

(53) 1: Arbitrarily selected one recess 2: Recess adjacent to the arbitrarily selected one recess 3: Recess adjacent to the arbitrarily selected one recess A: Interval between recess 1 and recess 2 B: Interval between recess 1 and recess 3 10: Interlayer film for a laminated glass 11: Recess having a groove shape with a continuous bottom on first surface 12: Recess having a groove shape with a continuous bottom on second surface 20: Protrusions and recesses on first surface or second surface 21: Recess having a groove shape with a continuous bottom 22: protrusion