Interlayer film for colored laminated glass, and colored laminated glass

Abstract

The present invention aims to provide an interlayer film for a colored laminated glass which exhibits a visible light transmittance Tv of 5% or lower, small variation in visible light transmittance and an excellent appearance when incorporated in a laminated glass together with two clear glass plates in conformity with JIS R3202 (1996), and a colored laminated glass produced using the interlayer film for a colored laminated glass. Provided is an interlayer film for a colored laminated glass exhibiting a visible light transmittance Tv of 5% or lower when incorporated in a laminated glass together with two clear glass plates in conformity with JIS R3202 (1996), the interlayer film for a colored laminated glass including a laminate of at least two layers including a first resin layer containing a thermoplastic resin and a colorant and a second resin layer containing a thermoplastic resin and no colorant, the first resin layer satisfying a ratio of a difference Δt.sub.1 in thickness between the maximum value t.sub.1max and the minimum value t.sub.1min to an average thickness (Δt.sub.1/average thickness of first resin layer) of 0.30 or less.

Claims

1. An interlayer film for a colored laminated glass exhibiting a visible light transmittance Tv of 5% or lower when incorporated in a laminated glass together with two clear glass plates in conformity with JIS R3202 (1996), the interlayer film for a colored laminated glass comprising a laminate of at least two layers including a first resin layer containing a thermoplastic resin and a colorant and a second resin layer containing a thermoplastic resin and no colorant, the first resin layer satisfying a ratio of a difference Δt.sub.1 in thickness between the maximum value t.sub.1max and the minimum value t.sub.1min to an average thickness (Δt.sub.1 of first resin layer/average thickness of first resin layer) of 0.30 or less, wherein the interlayer film has recesses on at least one surface thereof, and wherein a CV value of visible light transmittance (%) obtained by a following equation is 24.6% or less:
CV value=standard deviation/average of visible light transmittance×100.

2. The interlayer film for a colored laminated glass according to claim 1, comprising a laminate of at least three layers including a first resin layer interposed between two second resin layers.

3. The interlayer film for a colored laminated glass according to claim 1, wherein the first resin layer has an average thickness of 100 to 500 μm and the second resin layer has an average thickness of 100 μm or more.

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

5. The interlayer film for a colored laminated glass according to claim 2, wherein the first resin layer has an average thickness of 100 to 500 μm and the second resin layer has an average thickness of 100 μm or more.

6. A colored laminated glass comprising: a pair of glass plates; and the interlayer film for a colored laminated glass according to claim 2 interposed between the pair of glass plates.

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

8. A colored laminated glass comprising: a pair of glass plates; and the interlayer film for a colored laminated glass according to claim 5 interposed between the pair of glass plates.

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 3D roughness image data obtained by the measurement using a 3D profilometer performed on a surface of an interlayer film for a laminated glass having recesses each having a groove shape with a continuous bottom on the surface.

DESCRIPTION OF EMBODIMENTS

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

EXAMPLE 1

(5) (1) Preparation of a Resin Composition for a First Resin Layer

(6) Polyvinyl alcohol having an average degree of polymerization of 1,700 was acetalized using n-butyraldehyde to provide 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 % (hereafter, also referred to as “PVB1”). To 100 parts by mass of the PVB1 were added 40 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer and carbon black as a colorant, and they were sufficiently kneaded using a mixing roll to prepare a resin composition for a first resin layer. The amount of the added colorant was set to 0.095% by mass in 100% by mass of the first resin layer and 0.038% by mass in 100% by mass of the entire interlayer film for a colored laminated glass to be obtained.

(7) (2) Preparation of a Resin Composition for a Second Resin Layer

(8) To 100 parts by mass of the PVB1 was added 40 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer, and they were sufficiently kneaded using a mixing roll to prepare a resin composition for a second resin layer.

(9) (3) Production of an Interlayer Film for a Colored Laminated Glass

(10) The obtained resin composition for a first resin layer and resin composition for a second resin layer were extruded from a co-extruder under the condition of an extrusion temperature of 200° C., thereby preparing an interlayer film for a colored laminated glass having a two-layer structure (first resin layer/second resin layer).

(11) The thickness of each resin layer of the obtained interlayer film for a colored laminated glass was measured by the method described above. Table 1 shows the thickness of each resin layer.

(12) (4) Production of a Colored Laminated Glass

(13) The obtained interlayer film for a colored laminated glass was sandwiched between a pair of clear glass plates (5 cm in length×5 cm in width, 2.5 mm in thickness) in conformity with JIS R3202 (1996) to prepare a laminate. The obtained laminate was press-bonded under vacuum at 90° C. for 30 minutes using a vacuum laminator. The press-bonded laminate was further press-bonded for 20 minutes under 14 MPa at 140° C. using an autoclave. Thus, a colored laminated glass was obtained.

EXAMPLE 2

(14) An interlayer film for a colored laminated glass having a three-layer structure (second resin layer/first resin layer/second resin layer) was produced in which the thickness of each resin layer was adjusted to the value as shown in Table 1 using the resin composition for a first resin layer and the resin composition for a second resin layer obtained in Example 1. The interlayer film for a laminated glass was produced as in Example 1.

COMPARATIVE EXAMPLE 1

(15) In the preparation of a resin composition for a first resin layer, the amount of the added colorant was changed to 0.245% by mass in 100% by mass of the resulting first resin layer and 0.037% by mass in 100% by mass of the entire interlayer film for a colored laminated glass to be obtained. Using this resin composition for a first resin layer, an interlayer film for a colored laminated glass having a three-layer structure in which the thickness of each resin layer was adjusted to the value as shown in Table 2 was produced as in Example 2.

COMPARATIVE EXAMPLE 2

(16) In the preparation of a resin composition for a first resin layer, the amount of the added colorant was changed to 0.160% by mass in 100% by mass of the resulting first resin layer and 0.038% by mass in 100% by mass of the entire interlayer film for a colored laminated glass to be obtained. Using this resin composition for a first resin layer, an interlayer film for a colored laminated glass having a three-layer structure in which the thickness of each resin layer was adjusted to the value as shown in Table 2 was produced as in Example 2.

EXAMPLE 3

(17) (1) Preparation of a Resin Composition for a First Resin Layer

(18) To 100 parts by mass of PVB1 were added 42 parts by mass of 3GO as a plasticizer and carbon black as a colorant, and they were sufficiently kneaded using a mixing roll to prepare a resin composition for a first resin layer. The amount of the added carbon black was set to 0.171% by mass in 100% by mass of the first resin layer and 0.058% by mass in 100% by mass of the resulting colored interlayer film.

(19) (2) Preparation of a Resin Composition for a Second Resin Layer

(20) To 100 parts by mass of PVB1 was added 38.5 parts by mass of 3GO as a plasticizer, and they were sufficiently kneaded using a mixing roll to prepare a resin composition for a second resin layer.

(21) (3) Production of an Interlayer Film for a Colored Laminated Glass

(22) The obtained resin compositions for a first resin layer and for a second resin layer were extruded from a co-extruder under the condition of an extrusion temperature of 200° C., thereby preparing a laminate having a three-layer structure (second resin layer/first resin layer/second resin layer).

(23) (4) Formation of Recesses

(24) A pair of embossing rolls having a large number of fine recesses and a large number of fine protrusions formed thereon was used as a device for transferring fine protrusions and recesses. The obtained laminate was passed through the embossing rolls. Thus, a laminate having a large number of fine recesses and a large number of fine protrusions formed thereon was prepared.

(25) Another pair of embossing rolls was further used as a device for transferring protrusions and recesses. The obtained laminate having a large number of fine recesses and a large number of fine protrusions formed thereon was passed through the embossing rolls, and to the both surfaces of the laminate were formed recesses having a surface roughness (Rz) of 31 μm in which recesses each having a groove shape with a continuous bottom (shape of an engraved line) were formed in parallel to each other at equal intervals. Thus, an interlayer film for a colored laminated glass was obtained. The pairs of embossing rolls each include a metal roll having a surface milled with a triangular oblique line-type mill and a rubber roll having a JIS hardness of 45 to 75.

(26) The surface roughness Rz was measured by a method in conformity with JIS B-0601 (1994). The transferring conditions for formation of the recesses each having a groove shape (shape of an engraved line) were a temperature of a laminate of 95° C., a roll temperature of 130° C., and a press pressure of 500 kPa.

(27) The thickness of each resin layer of the obtained interlayer film for a colored laminated glass was measured by the method described above. Table 1 shows the thickness of each resin layer.

(28) (5) Production of a Colored Laminated Glass

(29) The obtained interlayer film for a colored laminated glass was sandwiched between a pair of clear glass plates (5 cm in length×5 cm in width, 2.5 mm in thickness) in conformity with JIS R3202 (1996) to prepare a laminate. The obtained laminate was press-bonded under vacuum at 90° C. for 30 minutes using a vacuum laminator. The press-bonded laminate was further press-bonded for 20 minutes under 14 MPa at 140° C. using an autoclave. Thus, a colored laminated glass was obtained.

EXAMPLES 4 TO 7, COMPARATIVE EXAMPLES 3 TO 6

(30) An interlayer film for a colored laminated glass and a colored laminated glass were obtained as in Example 3, except that the amount of the plasticizer, the concentration of the colorant, and the thickness of each resin layer were changed as shown in Table 1 or 2.

EXAMPLE 8, COMPARATIVE EXAMPLE 7

(31) An interlayer film for a colored laminated glass and a colored laminated glass were obtained as in Example 3, except that the resin used for the first resin layer was changed from PVB1 to polyvinyl butyral 2 (hereafter, also referred to as “PVB2”) and the amount of the plasticizer, the concentration of the colorant, and the thickness of each resin layer were changed as shown in Table 1 or 2.

(32) PVB2 was obtained by acetalizing polyvinyl alcohol having an average degree of polymerization of 2,300 with n-butyraldehyde, and had an acetyl group content of 12 mol %, a butyral group content of 66 mol %, and a hydroxy group content of 22 mol %.

(33) (Evaluation)

(34) The interlayer films for a laminated glass obtained in the examples and comparative examples were evaluated by the following method. Tables 1 and 2 show the results.

(35) (Measurement of Visible Light Transmittance)

(36) The visible light transmittance within a wavelength range of 380 to 780 nm was measured at an arbitrarily selected 20 sites on the obtained laminated glass using a spectrophotometer (“U-4100” available from Hitachi High-Technologies Corporation) in conformity with JIS R 3106 (1998). The average and the standard deviation of the visible light transmittances measured at 20 sites were obtained. The obtained standard deviation was divided by the average of the visible light transmittances, and the quotient was centupled. The obtained value (standard deviation/average of visible light transmittance×100) was defined as a CV value. The visible light transmittance of the clear glass plates used in the examples and comparative examples was 90.5%.

(37) TABLE-US-00001 TABLE 1 Ex- Ex- Ex- Ex- Ex- Ex- Ex- Ex- ample ample ample ample ample ample ample ample 1 2 3 4 5 6 7 8 Resin First Resin Kind PVB1 PVB1 PVB1 PVB1 PVB1 PVB1 PVB1 PVB2 com- resin Parts by 100 100 100 100 100 100 100 100 position layer mass Plasticizer Kind 3GO 3GO 3GO 3GO 3GO 3GO 3GO 3GO Parts by 40 40 42 42 42 40 38.5 60 mass Colorant Kind Carbon Carbon Carbon Carbon Carbon Carbon Carbon Carbon black black black black black black black black % by 0.095 0.095 0.171 0.193 0.150 0.171 0.085 0.289 mass Second Resin Kind PVB1 PVB1 PVB1 PVB1 PVB1 PVB1 PVB1 PVB1 resin Parts by 100 100 100 100 100 100 100 100 layer mass Plasticizer Kind 3GO 3GO 3GO 3GO 3GO 3GO 3GO 3GO Parts by 40 40 38.5 38.5 38.5 40 42 38 mass Interlayer Second t.sub.2max μm 500 260 175 186 170 174 115 347 film for resin t.sub.2min μm 400 220 150 158 147 150 89 320 colored layer Δ t.sub.2 μm 100 40 25 28 23 24 26 27 laminated Average μm 455 235 165 170 160 165 100 330 glass thickness First t.sub.1max μm 345 335 181 163 186 186 314 109 resin t.sub.1min μm 270 270 160 135 165 155 286 91 layer Δ t.sub.1 μm 75 65 21 28 21 31 28 18 Average μm 305 300 170 150 170 170 300 100 thickness Second t.sub.2max μm — 255 174 196 183 176 109 345 resin t.sub.2min μm — 210 151 169 158 153 89 319 layer Δ t.sub.2 μm — 45 23 27 25 23 20 26 Average μm — 225 165 180 170 165 100 330 thickness Entire Colorant % by 0.038 0.038 0.058 0.058 0.051 0.058 0.051 0.038 inter- mass layer film Δt.sub.1/t.sub.1 average 0.25 0.22 0.12 0.19 0.12 0.18 0.09 0.18 Eval- Average (%) of visible 1.52 1.49 1.52 1.6 4.86 1.56 4.9 1.59 uation light transmittance Tv CV value (%) of visible 25.8 24.6 18.5 20.6 7.9 13.1 8 20.6 light transmittance Tv

(38) TABLE-US-00002 TABLE 2 Com- Com- Com- Com- Com- Com- Com- parative parative parative parative parative parative parative Ex- Ex- Ex- Ex- Ex- Ex- Ex- ample ample ample ample ample ample ample 1 2 3 4 5 6 7 Resin First Resin Kind PVB1 PVB1 PVB1 PVB1 PVB1 PVB1 PVB2 com- resin Parts by 100 100 100 100 100 100 100 position layer mass Plasticizer Kind 3GO 3GO 3GO 3GO 3GO 3GO 3GO Parts by 40 40 42 42 42 40 60 mass Colorant Kind Carbon Carbon Carbon Carbon Carbon Carbon Carbon black black black black black black black % by 0.245 0.160 0.171 0.193 0.150 0.171 0.289 mass Second Resin Kind PVB1 PVB1 PVB1 PVB1 PVB1 PVB1 PVB1 resin Parts by 100 100 100 100 100 100 100 layer mass Plasticizer Kind 3GO 3GO 3GO 3GO 3GO 3GO 3GO Parts by 40 40 38.5 38.5 38.5 40 38 mass Interlayer Second t.sub.2max μm 355 335 181 191 176 179 356 film for resin t.sub.2min μm 300 280 143 152 142 146 313 colored layer Δ t.sub.2 μm 55 55 38 39 34 33 43 laminated Average μm 325 300 165 170 160 165 330 glass thickness First t.sub.1max μm 150 220 201 173 203 198 119 resin t.sub.1min μm 85 150 148 124 149 142 87 layer Δ t.sub.1 μm 65 70 53 49 54 56 32 Average μm 115 180 170 150 170 170 100 thickness Second t.sub.2max μm 345 310 183 205 193 181 356 resin t.sub.2min μm 300 270 147 169 150 141 315 layer Δ t.sub.2 μm 45 40 36 36 43 40 41 Average μm 320 290 165 180 170 165 330 thickness Entire Colorant % by 0.037 0.038 0.058 0.058 0.051 0.058 0.038 interlayer mass film Δt.sub.1/t.sub.1 average 0.57 0.39 0.31 0.33 0.32 0.33 0.32 Eval- Average (%) of visible 2.35 2.12 1.63 1.53 4.78 1.65 1.55 uation light transmittance Tv CV value (%) of visible 44.6 37.3 34 29 12 36 34.5 light transmittance Tv

INDUSTRIAL APPLICABILITY

(39) The present invention can provide an interlayer film for a colored laminated glass which exhibits, when incorporated in a laminated glass together with two clear glass plates in conformity with JIS R3202 (1996), an excellent-appearance laminated glass having a visible light transmittance Tv of 5% or lower, small variation in visible light transmittance from portion to portion and an excellent appearance, and a colored laminated glass produced using the interlayer film for a colored laminated glass.