Filling-bonding material, protective sheet-equipped filling-bonding material, laminated body, optical device, and protective panel for optical device

Abstract

The present invention aims to provide a filling-bonding material that is suitably used to fill a space between parts, while bonding the parts, in optical devices in various shapes not limited to flat shapes. The present invention also aims to provide a protective sheet-equipped filling-bonding material, a laminate, an optical device, and a protective panel for an optical device each including the filling-bonding material. Provided is a filling-bonding material having a shape with an uneven thickness.

Claims

1. A self-supporting filling-bonding material having a shape with an uneven thickness, wherein a width of the filling-bonding material has a value of 50 mm or greater, wherein the uneven thickness being defined between a curved surface and an opposing surface, wherein the curved surface has a principal curvature of 1/1000 mm.sup.−1 or more and has a positive or negative Gaussian curvature, and wherein the filling-bonding material has a light-transmitting portion, wherein the light transmitting portion has an average residual phase difference (R.sub.ave) of 20 nm/mm or less and/or an in-plane standard deviation (s) of a phase difference of 10 nm or less.

2. The filling-bonding material according to claim 1, wherein the light transmitting portion has a visible light transmittance of 80% or higher and a haze of 1% or lower.

3. The filling-bonding material according to claim 1, wherein the opposing surface is a flat surface.

4. The filling-bonding material according to claim 1, wherein a thickest part of the filling-bonding material comprises a thickness of 500 μm or greater.

5. The filling-bonding material according to claim 1, wherein the curved surface has a chord length of 50 mm or longer.

6. The filling-bonding material according to claim 1, having a glass transition temperature (Tg) of 10° C. or higher and 60° C. or lower.

7. The filling-bonding material according to claim 1, having a storage modulus at 20° C. of 1×10.sup.4 Pa or greater and 1×10.sup.10 Pa or lower.

8. The filling-bonding material according to claim 1, comprising a polyvinyl acetal.

9. The filling-bonding material according to claim 1, further comprising a light-shielding portion or a light-scattering portion.

10. The filling-bonding material according to claim 9, wherein the light-shielding portion has a visible light transmittance of 10% or lower.

11. The filling-bonding material according to claim 9, wherein the light-scattering portion has a haze of 10% or higher.

12. The filling-bonding material according to claim 9, wherein the light-shielding portion or the light-scattering portion contains a dye or a pigment.

13. The filling-bonding material according to claim 9, wherein the light-shielding portion or the light-scattering portion is positioned at a periphery of the filling-bonding material.

14. A protective sheet-equipped filling-bonding material comprising: the filling-bonding material according to claim 1; and a protective sheet covering the filling-bonding material.

15. A laminate comprising: a pair of bonded parts; and the filling-bonding material according to claim 1, the filling-bonding material filling a space between the pair of bonded parts.

16. An optical device comprising the laminate according to claim 15, the pair of bonded parts including at least one transparent part, the transparent part and the filling-bonding material having a difference in refractive index of 0.03 or less.

17. A protective panel for an optical device comprising: a first panel; a second panel; and a self-supporting filling-bonding material having a shape with an uneven thickness, the uneven thickness being defined between a curved surface and an opposing surface, wherein the curved surface has a principal curvature of 1/5000 mm.sup.−1 or more, at least one of the first panel or the second panel having a curved surface, the first panel and the second panel being directly bonded to each other with the filling-bonding material, wherein the filling-bonding material has a light-transmitting portion, wherein the light transmitting portion has an average residual phase difference (R.sub.ave) of 20 nm/mm or less and/or an in-plane standard deviation (s) of a phase difference of 10 nm or less.

18. The protective panel for an optical device according to claim 17, wherein the panel with a curved surface, of the first panel and the second panel, and the filling-bonding material have a difference in refractive index of 0.1 or less.

19. The protective panel according to claim 17, wherein the filling-bonding material has a storage modulus at 23° C. of 1 MPa or greater and a tensile strength at break of 1 MPa or greater.

20. The protective panel for an optical device according to claim 17, wherein at least one of the first panel or the second panel is a glass plate.

21. The protective panel according to claim 20, wherein the filling-bonding material has a 180° peel strength at 300 mm/min of 5 N/25 mm or greater.

22. An optical device comprising the protective panel for an optical device according to claim 17.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows views schematically illustrating an exemplary filling-bonding material of the present invention and an exemplary embodiment thereof.

(2) FIG. 2 shows views schematically illustrating an exemplary filling-bonding material of the present invention and an exemplary embodiment thereof.

(3) FIG. 3 shows perspective views each schematically illustrating an exemplary filling-bonding material of the present invention.

(4) FIG. 4 shows a perspective view and a cross-sectional view each illustrating an exemplary filling-bonding material of the present invention.

(5) FIG. 5 shows a cross-sectional view schematically illustrating an exemplary filling-bonding material of the present invention and an exemplary embodiment thereof.

(6) FIG. 6 shows cross-sectional views schematically illustrating an exemplary filling-bonding material of the present invention and an exemplary embodiment thereof.

(7) FIG. 7 shows perspective views each schematically illustrating an exemplary filling-bonding material of the present invention having a light-shielding portion.

(8) FIG. 8 shows a perspective view schematically illustrating an exemplary protective sheet-equipped filling-bonding material of the present invention.

(9) FIG. 9 shows views each schematically illustrating an exemplary protective panel for an optical device of the present invention.

(10) FIG. 10 shows views each schematically illustrating an exemplary protective panel for an optical device of the present invention.

(11) FIG. 11 shows views each schematically illustrating an exemplary protective panel for an optical device of the present invention.

(12) FIG. 12 shows a view schematically illustrating an exemplary protective panel for an optical device of the present invention.

(13) FIG. 13 shows a view schematically illustrating an exemplary embodiment of the protective panel for an optical device of the present invention.

(14) FIG. 14 shows a view schematically illustrating an exemplary method for producing the protective panel for an optical device of the present invention.

(15) FIG. 15 shows a view schematically illustrating an exemplary optical device including the filling-bonding material of the present invention.

(16) FIG. 16 shows a view schematically illustrating an exemplary optical device including the filling-bonding material of the present invention.

(17) FIG. 17 shows schematic views explaining the arc length and the chord length of the curved surface.

DESCRIPTION OF EMBODIMENTS

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

Preparation of Polyvinyl Butyral 1 (PVB1)

(19) A reactor equipped with a stirrer was charged with 2,700 mL of ion exchange water and 300 g of polyvinyl alcohol (average degree of polymerization: 850, degree of saponification: 99.0 mol %), and the polyvinyl alcohol was dissolved with stirring under heating. Thus, a solution was obtained. Next, to the solution was added 35% by weight hydrochloric acid as a catalyst to a hydrochloric acid concentration of 0.2% by weight. After adjustment of the solution temperature to 15° C., 21 g of n-butyraldehyde (n-BA) was added thereto with stirring. Then, 145 g of n-butyraldehyde (n-BA) was added, and polyvinyl butyral in the form of white particles was precipitated. Fifteen minutes later from the precipitation, 35% by weight hydrochloric acid was added to a hydrochloric acid concentration of 1.8% by weight, followed by heating to 50° C. and aging at 50° C. for two hours. The solution was then cooled and neutralized. The polyvinyl butyral was washed with water and dried. Thus, polyvinyl butyral (PVB1) was obtained. The obtained polyvinyl butyral 1 (PVB1) had a hydroxy group content of 31.0 mol %, an acetyl group content of 1.0 mol %, and a degree of butyralization of 68.0 mol %.

Preparation of Polyvinyl Butyral 2 (PVB2)

(20) A reactor equipped with a stirrer was charged with 2,700 mL of ion exchange water and 300 g of polyvinyl alcohol (average degree of polymerization: 850, degree of saponification: 88.0 mol %), and the polyvinyl alcohol was dissolved with stirring under heating. Thus, a solution was obtained. Next, to the solution were added 35% by weight hydrochloric acid as a catalyst to a hydrochloric acid concentration of 0.6% by weight. After adjustment of the solution temperature to 15° C., 14 g of n-butyraldehyde (n-BA) was added with stirring. Then, 186 g of n-butyraldehyde (n-BA) was added, and polyvinyl butyral in the form of white particles was precipitated. Fifteen minutes later from the precipitation, 35% by weight hydrochloric acid was added to a hydrochloric acid concentration of 3.9% by weight, followed by heating to 45° C. and aging at 45° C. for three hours. The solution was then cooled and neutralized. The polyvinyl butyral was washed with water and dried. Thus, polyvinyl butyral 2 (PVB2) was obtained. The obtained polyvinyl butyral 2 (PVB2) had a hydroxy group content of 24.0 mol %, an acetyl group content of 12.0 mol %, and a degree of butyralization of 64.0 mol %.

Example 1

(1) Production of Filling-Bonding Material

(21) An amount of 20 parts by weight of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer and 100 parts by weight of the polyvinyl butyral 1 (PVB1) prepared in (1) were mixed, and the mixture was press-molded with heating. Thus, a filling-bonding material (principal curvature: 1/1,000 mm.sup.−1, chord length: 200 mm, maximum value (t1) of thickness: 5.2 mm, minimum value of thickness: 200 μm, maximum value of width: 200 mm) in a shape with an uneven thickness (shape including a flat surface and a convex surface facing the flat surface) was obtained.

(2) Measurement of Storage Modulus of Filling-Bonding Material at 20° C. and 80° C., Measurement of Tg (Maximum Value of Tan δ)

(22) The viscoelasticity measurement of the filling-bonding material was performed using a dynamic viscoelastometer (ARES-G2 available from TA Instruments Japan Inc.) under the condition of increasing the temperature from −50° C. to 100° C. at a rate of temperature rise of 3° C./min and the conditions of a frequency of 1 Hz and a shearing strain of 1%. Thus, the storage moduli of the filling-bonding material at 20° C. and 80° C. were obtained. The storage moduli at 20° C. and 80° C. were 6.9×10.sup.7 Pa and 9.2×10.sup.5 Pa, respectively. Tg was 29.3° C.

(3) Measurement of Visible Light Transmittance and Haze

(23) The visible light transmittance and haze of the filling-bonding material at the light-transmitting part were measured in conformity with JIS K 7136: 2000 using a spectrophotometer U4100 available from Hitachi High-Technologies Corporation.

(4) Measurement of Average Residual Phase Difference (Rave)

(24) The light-transmitting portion of the filling-bonding material was divided into 100 sections in a plan view in the optical axis direction, and the phase difference (R0) in each divided region was measured with a light at a wavelength of 520 nm using PA-200 available from Photonic Lattice, Inc. Using the values (D) of the thicknesses at respective regions, the average of the residual phase difference (R1=R0/D) was calculated as Rave.

(5) Measurement of In-Plane Standard Deviation (s) of Phase Difference

(25) The light-transmitting portion of the filling-bonding material was divided into 50,000 sections in a plan view in the optical axis direction, and the phase difference in each divided region was measured with light at a wavelength of 520 nm using PA-200 available from Photonic Lattice, Inc. The measurement results were processed using software (PA-View 2.2.4), and the in-plane standard deviation (s) of the phase difference was obtained.

Example 2

(26) The filling-bonding material obtained in Example 1 was placed in a mold of the same size, and subjected to annealing treatment (60° C. for five hours).

Example 3

(27) A filling-bonding material was obtained as in Example 2, except that the amount of the added plasticizer was changed to 30 parts by weight.

Example 4

(28) A filling-bonding material was obtained as in Example 2, except that PVB2 was used instead of PVB1 and the amount of the added plasticizer was changed to 60 parts by weight.

Example 5

(29) A filling-bonding material was obtained as in Example 4, except that the amount of the added plasticizer was changed to 25 parts by weight.

Example 6

(30) A filling-bonding material was obtained as in Example 1, except that a cobalt blue pigment (C. I. pigment blue 28 available from Asahi Kasei Kogyo Co., Ltd.) was added to the plasticizer. The cobalt blue pigment was added in an amount of 0.02 parts by weight relative to 100 parts by weight of PVB1.

Example 7

(31) A filling-bonding material was obtained as in Example 1, except that a cobalt blue pigment (Nanotek cobalt blue Slurry (15% alcohol solution) available from C. I. Kasei Co., Ltd.) was added to the plasticizer. The cobalt blue pigment (solid content) was added in an amount of 0.012 parts by weight relative to 100 parts by weight of PVB1.

Example 8

(32) A filling-bonding material was obtained as in Example 7, except that the amount of the cobalt blue pigment (solid content) was changed to 0.0072 parts by weight relative to 100 parts by weight of PVB1.

Example 9

(33) A filling-bonding material was obtained as in Example 2, except that the annealing temperature was changed to 40° C.

Example 10

(34) A filling-bonding material was obtained as in Example 1, except that no plasticizer was added.

Evaluation

(35) The filling-bonding materials obtained in Examples 1 to 9 were evaluated by the following methods. Table 1 shows the results.

(1) Evaluation of Filling/Bonding Properties Between Parts

(36) Two sheets of plate glass (200 mm×100 mm, thickness: 1 mm) were prepared. One was used as it was (flat plate). The other was subjected to heat-molding to be curved in a direction of the 200-mm side, preparing a curved glass having a curvature radius of 1,000 mm.

(37) Next, the filling-bonding material obtained in each example was placed such that its flat surface faces the flat glass, and the curved glass was placed to correspond to the curved surface of the filling-bonding material. Thus, the flat glass, the filling-bonding material, and the curved glass were stacked in the stated order.

(38) Then, the laminate was treated in a heating vacuum laminator under the conditions of 70° C. and 200 Pa for three minutes. The laminate was further treated in an autoclave at 70° C. and 5 Mpa for 30 minutes. Thus a laminate including the flat glass, the filling-bonding material, and the curved glass (protective panel for an optical device in which the plate glass and the curved glass were directly bonded to each other using the filling-bonding material) was produced. The obtained laminate was visually observed in an initial state (right after the production) and 48 hours later to check the presence or absence of a remaining space or foaming due to defective lamination. The case where no remaining space or foaming was observed was rated good (∘) and the case where a remaining space or foaming was observed was rated poor (x).

(2) Evaluation of High-Temperature Reliability

(39) A laminate (protective panel for an optical device in which the flat glass and the curved glass were directly bonded to each other using the filling-bonding material) obtained as in (1) was allowed to stand still in a high-temperature and high-humidity environment (85° C., 85%) for 240 hours, and the presence or absence of foaming was visually checked. The case where no foaming was observed was rated good (∘) and the case where foaming was observed was rated poor (x).

(3) Evaluation of Optical Quality

(40) Characters in white were displayed on a black background on the flat display, and the black display portion in the background was observed through polarizing glasses. Next, the laminate (protective panel for an optical device in which flat glass and curved glass were directly bonded to each other using the filling-bonding material) obtained as in (1) was placed on the screen of the flat display, and the presence or absence of a white part (white blank) and the presence or absence of blurring of the characters were visually observed.

(41) The results before and after the placement of the laminate on the flat display were compared. With regard to the presence or absence of a white part (white blank), the case where any change in color was not observed, while black display was maintained, in the black display portion was rated good (∘). The case where a sense of discomfort was evoked, though no white portion was recognized, was rated fair (Δ). The case where a white part was clearly visually observed was rated poor (x). Similarly, with regard to the presence or absence of blurring of the characters, the case where the outlines of the characters were clearly recognized was rated good (∘). The case where distorted outlines of the characters were recognized was rated fair (Δ). The case where the shapes of the characters were clearly deformed to be blurred was rated poor (x).

(42) TABLE-US-00001 TABLE 1 Evaluation Filing/ bonding properties Pres- ence Pres- or ab- ence Optical sence or quality Optical characteristics of ab- Pres- Pres- Vis- foam- sence ence ence Composition ible ing of or or Plasti- Pig- light right foam- High- ab- ab- Resin cizer ment Treat- Elasticity trans- after ing temper- sence sence Parts Parts Parts ment G′ at G′ at mit Rave pro- 48 ature of of by by by An- 20° C. 80° C. Tg tance Haze nm/ s duc- hours reli- white blur- weight weight weight nealing Pa Pa ° C. % % mm nm tion later ability blank ring Example PVB1 20 0 Not 6.9 × 10.sup.7 9.2 × 10.sup.5 29.3 91.2 0.1 21.5 12.1 ∘ ∘ ∘ x ∘ 1 per- formed Example PVB1 20 0 60° C. 7.3 × 10.sup.7 8.6 × 10.sup.5 29.5 91 0.1 5.2 2.2 ∘ ∘ ∘ ∘ ∘ 2 5 h Example PVB1 30 0 60° C. 1.7 × 10.sup.7 4.6 × 10.sup.5 18.8 91.3 0.1 4.9 1.9 ∘ ∘ ∘ ∘ ∘ 3 5 h Example PVB2 60 0 60° C. 2.2 × 10.sup.6 3.5 × 10.sup.5 −4.3 91.3 0.1 2.9 1.7 ∘ ∘ x ∘ ∘ 4 5 h Example PVB2 25 0 60° C. 9.8 × 10.sup.6 4.1 × 10.sup.5 22.1 91.1 0.1 2.9 1.7 ∘ ∘ ∘ ∘ ∘ 5 5 h Example PVB1 20 0.02 Not 7.1 × 10.sup.7 8.6 × 10.sup.5 30.1 78.1 2.6 22.4 13.5 ∘ ∘ ∘ x x 6 per- formed Example PVB1 20 0.012 Not 7.5 × 10.sup.7 8.8 × 10.sup.5 29.5 86.1 0.4 21.5 12.2 ∘ ∘ ∘ x Δ 7 per- formed Example PVB1 20 0.0072 Not 7.5 × 10.sup.7 8.9 × 10.sup.5 28.7 88.4 0.3 21.8 11.9 ∘ ∘ ∘ x ∘ 8 per- formed Example PVB1 20 0 40° C. 7.0 × 10.sup.7 9.1 × 10.sup.5 29.5 91.4 0.1 11.4 5.1 ∘ ∘ ∘ ∘ ∘ 9 5 h Example PVB1 0 0 Not 8.5 × 10.sup.8 2.5 × 10.sup.6 68.8 90.8 0.1 22.3 13.8 ∘ x x x ∘ 10 per- formed

INDUSTRIAL APPLICABILITY

(43) The present invention can provide a filling-bonding material that is suitably used to fill a space between parts, while bonding the parts, in optical devices in various shapes not limited to flat shapes. The present invention can also provide a protective sheet-equipped filling-bonding material, a laminate, an optical device, and a protective panel for an optical device each including the filling-bonding material.

REFERENCE SIGNS LIST

(44) 1 filling-bonding material 11 light-shielding portion 2 touch panel module 21 chassis 3 surface protection panel 31a first panel 31b second panel 32 protective panel for an optical device 4 hollow 5 protective sheet 6 protective sheet-equipped filling-bonding material 7 optical device 8 bond or adhesive 9 display module