Resin film for laminated glass, and laminated glass and preparation thereof
A resin film for laminated glass, laminated glass including the resin film, and a process for manufacturing the laminated glass are disclosed. The resin film for laminated glass comprises a resin layer comprising a polyvinyl acetal resin and a contact surface in direct contact with glass, wherein the contact surface has an Rz roughness of 25 to 90 μm and a maximum static friction coefficient at 20° C. of 0.85 to 1.60, and the compressive elastic deformation index measured in the perpendicular direction from the contact surface at 35° C. is 40 to 310 μm/N.
1. A resin film for laminated glass, which comprises:
a resin layer comprising a polyvinyl acetal resin and a contact surface in direct contact with glass,
wherein the contact surface has an Rz roughness of 25 to 90 μm, a maximum static friction coefficient at 20° C. of 0.85 to 1.60, a maximum static friction coefficient at 40° C. of 1.05 to 1.80, and a maximum static friction coefficient at 45° C. of 1.20 to 2.10,
wherein a content of OH group in the polyvinyl acetal resin is 36 to 54% by mole, and
wherein a compressive elastic deformation index defined by the following Equation 1 and measured in the perpendicular direction from the contact surface at 35° C. is 40 to 310 μm/N:
Compressive elastic deformation index= d/F Equation 1
wherein F is a force of 0.05 to 0.6 N applied in the direction perpendicular to the contact surface by a tip having a flat end and a diameter of 4 mm, and d is a depth that is compressively deformed in the perpendicular direction by the tip.
2. The resin film for laminated glass of claim 1 , which has a compressive elastic deformation index of 80 to 310 μm/N when F is 0.05 to 0.2 N and a compressive elastic deformation index of 60 to 140 μm/N when F is 0.2 to 0.4 N.
3. The resin film for laminated glass of claim 1 , wherein the resin layer further comprises a plasticizer.
4. The resin film for laminated glass of claim 3 , wherein the resin layer comprises 20 to 50 parts by weight of the plasticizer based on 100 parts by weight of the first polyvinyl acetal resin, and the plasticizer is at least one selected from the group consisting of an ester-based plasticizer and a phosphoric acid-based plasticizer.
5. The resin film for laminated glass of claim 3 , wherein the polyvinyl acetal resin is prepared from a mixture of polyvinyl alcohols that comprise 5 to 15% by weight of a polyvinyl alcohol having a degree of polymerization of 1,000 to 1,300, 70 to 85% by weight of a polyvinyl alcohol having a degree of polymerization of 1,500 to 1,900, and 8 to 25% by weight of a polyvinyl alcohol having a degree of polymerization of 2,000 to 2,500.
6. The resin film for laminated glass of claim 1 , wherein the thickness of the resin layer is 580 to 940 μm, and the upper and lower sides of the resin layer are in contact with glass, respectively.
7. A laminated glass, which comprises a first glass panel; the resin film for laminated glass of claim 1 ; and a second glass panel sequentially laminated.
8. A process for manufacturing a laminated glass, which comprises:
(1) disposing the resin film for laminated glass of claim 1 on a first glass panel;
(2) disposing a second glass panel on the resin film for laminated glass; and
(3) aligning the second glass panel with respect to the first glass panel.
9. A resin film for laminated glass, which comprises a structure in which a first skin layer, an intermediate resin layer, and a second skin layer are sequentially laminated,
wherein the first skin layer and the second skin layer each comprise a first contact surface or a second contact surface in direct contact with glass,
the first skin layer and the second skin layer each comprise a first polyvinyl acetal resin,
the first contact surface and the second contact surface each have an Rz roughness of 25 to 90 μm, a maximum static friction coefficient at 20° C. of 0.85 to 1.60, a maximum static friction coefficient at 40° C. of 1.05 to 1.80, and a maximum static friction coefficient at 45° C. of 1.20 to 2.10,
wherein a content of OH group in the first polyvinyl acetal resin is 36 to 54% by mole, and
wherein a compressive elastic deformation index defined by the following Equation 1 and measured in the perpendicular direction from each of the first contact surface and the second contact surface at 35° C. is 40 to 310 μm/N:
Compressive elastic deformation index= d/F Equation 1
wherein F is a force of 0.05 to 0.6 N applied in the direction perpendicular to the contact surface by a tip having a flat end and a diameter of 4 mm, and d is a depth that is compressively deformed in the perpendicular direction by the tip.
10. The resin film for laminated glass of claim 9 , wherein the thicknesses of the first skin layer and the thicknesses of the second skin layer are 250 to 400 μm, respectively, and the thickness of the intermediate resin layer is 80 to 140 μm.
11. The resin film for laminated glass of claim 9 , wherein the intermediate resin layer comprises a second polyvinyl acetal resin and a plasticizer,
the intermediate resin layer comprises 30 to 40 parts by weight of the plasticizer based on 100 parts by weight of the second polyvinyl acetal resin, and
a content of OH group in the second polyvinyl acetal resin is 5 to 30% by mole.
12. A laminated glass, which comprises a first glass panel; the resin film for laminated glass of claim 9 ; and a second glass panel sequentially laminated.
13. A process for manufacturing a laminated glass, which comprises:
(1) disposing the resin film for laminated glass of claim 9 on a first glass panel;
(2) disposing a second glass panel on the resin film for laminated glass; and
(3) aligning the second glass panel with respect to the first glass panel.