Film for laminated glass, method of manufacturing embossing patterns of film for laminated glass, method of manufacturing embossing pattern transfer device, and embossing pattern transfer device

1. A film for laminated glass, the film comprising:

a surface embossing pattern formed on at least a portion of one side of the film,

wherein the surface embossing pattern comprises a plurality of convexities, and a plurality of concavities separating each of the plurality of convexities from one another,

wherein each of the plurality of convexities has a boundary defined by some of the plurality of concavities,

wherein an average area of the plurality of convexities is 0.01 mm 2 to 4.00 mm 2 ,

wherein a line shared by one of the plurality of convexities and the plurality of concavities defining the boundary of the one of the plurality of convexities forms a closed curve,

wherein each of the plurality of convexities has a shape of a polygon comprising vertexes,

an internal angle of each of the vertexes of the polygon is more than 40° and less than 180°, and

wherein the internal angles of all of the vertexes of the polygon are different from each other.

2. The film for laminated glass of claim 1 , wherein the plurality of concavities intersect with each other to form lines, and

each of the lines has two or more breakpoints at which a direction of the line changes.

3. The film for laminated glass of claim 1 , wherein each one of the plurality of convexities shares some of the plurality of concavities with some of the plurality of convexities that are adjacent to the one of the plurality of convexities, and

either one or both of a shape and an area of the some of the plurality of convexities that are adjacent to the one of the plurality of convexities are different from either one or both of a shape and an area of the one of the plurality of convexities.

4. The film for laminated glass of claim 3 , wherein a number of some of the plurality of convexities that are adjacent to the one of the plurality of convexities is three to eight.

5. The film for laminated glass of claim 1 , wherein the surface embossing pattern formed on at least the portion of the one side of the film is a first surface embossing pattern,

the film further comprises a second surface embossing pattern formed on at least a portion of another side of the film,

the second surface embossing pattern comprises a plurality of convexities and a plurality of concavities separating each of the plurality of convexities of the second surface embossing pattern from one another, and

shapes of the plurality of convexities in a unit area of 1 cm 2 of the first surface embossing pattern are different from shapes of the plurality of convexities in a unit area of 1 cm 2 of the second surface embossing pattern.

6. The film for laminated glass of claim 1 , wherein the one side of the film comprises a concavity A, a concavity B, and a concavity C in a cross-section of a unit area of 1 cm 2 ,

the concavity B is adjacent to the concavity A,

the concavity C is adjacent to the concavity B, and

a distance between the concavity A and the concavity B is different from a distance between the concavity B and the concavity C.

7. The film for laminated glass of claim 1 , wherein there are 24 to 9,800 convexities in a unit area of 1 cm 2 of the surface embossing pattern, and

a standard deviation of areas of the convexities in the unit area of 1 cm 2 of the surface embossing pattern is 0.01 to 0.4.

8. The film for laminated glass of claim 1 , wherein the internal angles of two or more of the vertexes of the polygon are equal to each other, and the internal angles of remaining ones of the vertexes of the polygon are different from each other remaining ones of the vertexes.

9. The film for laminated glass of claim 1 , wherein a value of deaeration performance of the film at 40° C. is 80% or more of a value of deaeration performance of the film at 20° C.

10. The film for laminated glass of claim 1 , wherein each of the plurality of convexities has a shape of a polygon, and

the polygon is any one of a triangle, a quadrilateral, a pentagon, a hexagon, a heptagon, and an octagon.

11. The film for laminated glass of claim 1 , wherein the plurality of concavities intersect with each other to form a line that begins at a start point where one of the plurality of concavities intersects a first edge of the surface embossing pattern, and extends along intersecting ones of the plurality of concavities to an end point where another one of the plurality of concavities intersects the first edge of the surface embossing pattern or a second edge of the surface embossing pattern.

12. The film for laminated glass of claim 1 , wherein 80% or more of the plurality of convexities in a unit area of 1 cm 2 of the surface embossing pattern have an area satisfying the following equation:

0.4 ×Sm≤Sni≤ 1.6 ×Sm

where Sni is an area of a convexity in the unit area of 1 cm 2 , and Sm is an average area of the plurality of convexities in the unit area of 1 cm 2 .

13. The film for laminated glass of claim 1 , wherein the surface embossing pattern formed on at least the portion of the one side of the film is a first surface embossing pattern,

the film for laminated glass further comprises a second surface embossing pattern formed on at least a portion of another side of the film opposite to the one side of the film,

the second surface embossing pattern comprises a plurality of convexities, and a plurality of concavities separating the plurality of convexities of the second surface embossing pattern from one another;

the plurality of concavities of the first surface embossing pattern comprise a first concavity and a third concavity,

the plurality of concavities of the second surface embossing pattern comprise a second concavity and a fourth concavity,

the first concavity, the second concavity, the third concavity, and the fourth concavity are disposed in a unit area of 1 cm 2 of the film when the film is viewed in a direction perpendicular to the one side of the film and the other side of the film,

the first concavity and the second concavity are adjacent to each other and a distance between the first concavity and the second concavity is d1 when the film is viewed in a cross-section of the unit area of 1 cm 2 of the film, the third concavity and the fourth concavity are adjacent to each other and a distance between the third concavity and the fourth concavity is d2 when the film is viewed in the cross-section of the unit area of 1 cm 2 of the film, and

d1 and d2 are different from each other.

14. The film for laminated glass of claim 1 , wherein the boundary is further defined by a plurality of concavities that are immediately adjacent to the each of the plurality of convexities.

15. The film for laminated glass of claim 1 , wherein the plurality of convexities are coplanar.

16. A method of manufacturing a film for laminated glass, the method comprising:

preparing an untreated film, a first embossing pattern transfer device comprising a first pattern, and a second embossing pattern transfer device comprising a second pattern; and

transferring the first pattern of the first embossing pattern transfer device to one side of the untreated film, and transferring the second pattern of the second embossing pattern transfer device to another side of the untreated film opposite the one side of the untreated film, thereby preparing a film for laminated glass,

wherein the first pattern of the first embossing pattern transfer device comprises first non-protrusions, and first protrusions separating the first non-protrusions from one another and being connected to each other so that each of the first non-protrusions has a boundary defined by some of the first protrusions,

the second pattern of the second embossing pattern transfer device comprises second non-protrusions, and second protrusions separating the second non-protrusions from each other and being connected to each other so that each of the second non-protrusions has a boundary defined by some of the second protrusions,

one side of the film for laminated glass comprises a first surface embossing pattern,

another side of the film for laminated glass opposite the one side of the film for laminated glass comprises a second surface embossing pattern,

the first surface embossing pattern comprises:

a plurality of first convexities corresponding to the first non-protrusions of the first pattern of the first embossing pattern transfer device; and

a plurality of first concavities corresponding to the first protrusions of the first pattern of the first embossing pattern transfer device, the plurality of first concavities separating the plurality of first convexities from each other and being connected to each other so that each of the plurality of first convexities has a boundary defined by some of the plurality of first concavities,

the second surface embossing pattern comprises:

a plurality of second convexities corresponding to the second non-protrusions of the second pattern of the second embossing pattern transfer device; and

a plurality of second concavities corresponding to the second protrusions of the second pattern of the second embossing pattern transfer device, the plurality of second concavities separating the plurality of second convexities from each other and being connected to each other so that each of the plurality of second convexities has a boundary defined by some of the plurality of second concavities,

an average area of the first convexities is 0.01 mm 2 to 4.00 mm 2 , and an average area of the second convexities is 0.01 mm 2 to 4.00 mm 2 ,

wherein a line shared by one of the plurality of convexities and the plurality of concavities defining the boundary of the one of the plurality of convexities forms a closed curve,

wherein each of the plurality of convexities has a shape of a polygon comprising vertexes,

an internal angle of each of the vertexes of the polygon is more than 40° and less than 180°, and

wherein the internal angles of all of the vertexes of the polygon are different from each other.