FUNCTIONAL SHEET INCLUDING POLYESTER RESIN, AND LENS USING FUNCTIONAL SHEET

Abstract

The present invention provides a functional sheet including a functional layer provided between protective layers. The functional layer is a polarizing film layer, a photochromic layer, or a combination of the polarizing film layer and the photochromic layer. At least one of the protective layers includes a layer formed of a resin (C) containing a polyester resin (A) obtained as a result of polycondensation of 1,4-cyclohexanedimethanol and 1,4-cyclohexanedicarboxylic acid and an aromatic polycarbonate resin (B), the polyester resin (A) being contained at a content of 10 to 100 parts by mass and the aromatic polycarbonate resin (B) being contained at a content of 0 to 90 parts by mass with respect to 100 parts by mass as a total of the polyester resin (A) and the aromatic polycarbonate resin (B). A lens is provided with such a functional sheet.

Claims

1. A functional sheet, comprising: a functional layer provided between a protective layer I and a protective layer II, the functional layer being a polarizing film layer, a photochromic layer, or a combination of the polarizing film layer and the photochromic layer; wherein at least one of the protective layer I and the protective layer II includes a layer formed of a resin (C) containing a polyester resin (A) obtained as a result of polycondensation of 1,4-cyclohexanedimethanol and 1,4-cyclohexanedicarboxylic acid and an aromatic polycarbonate resin (B), the polyester resin (A) being contained at a content of 10 to 100 parts by mass and the aromatic polycarbonate resin (B) being contained at a content of 0 to 90 parts by mass with respect to 100 parts by mass as a total of the polyester resin (A) and the aromatic polycarbonate resin (B).

2. The functional sheet according to claim 1, wherein the protective layer including the layer formed of the resin (C) includes the layer formed of the resin (C) and a layer formed of an aromatic polycarbonate resin, which are stacked to be integrated together, and the layer formed of the resin (C) is a front surface layer.

3. A lens obtained as a result of the functional sheet according to claim 1 being bent to be spherical or aspherical.

4. A lens obtained as a result of the functional sheet according to claim 1 bent such that the layer formed of the resin (C) is at a convexed surface, and a transparent resin being injection-molded to be put on a concaved surface of the functional sheet and integrated with the functional sheet.

5. A colored lens obtained as a result of the lens according to claim 3 being dyed.

6. The lens according to claim 3, wherein the lens includes a hard coat.

7. An eyewear item including the lens according to claim 3.

Description

EXAMPLES

[0050] Hereinafter, examples of the present invention will be described. The present invention is not limited to any of the following examples.

Example 1

<Production of a Protective Layer Sheet>

[0051] A protective layer sheet was produced with the polyester resin (A) (trade name: PRIMALLOY CP201 produced by Mitsubishi Chemical Corporation) by use of an extrusion device (PSV-30 produced by Plaengi Inc.) including a monoaxial extruder having a shaft diameter of 30 mm, a feed block coupled with the extruder and a T-die coupled with the feed block. The polyester resin (A) was continuously introduced into the monoaxial extruder having a shaft diameter of 30 mm and extruded under a condition of a cylinder temperature of 250° C. The polyester resin (A) was extruded into a sheet by the T-die coupled to a tip of the monoaxial extruder, and cooled while having a mirror surface transferred thereon by a mirror surface finishing roll. As a result, a sheet of the polyester resin (A) was obtained. The roll was set to a temperature of 100° C.

<Production of a Polarizing Film>

[0052] Poly(vinyl alcohol) (trade name: VF-PS#7500 produced by Kuraray Co., Ltd.) was stretched to twice as longer while being swollen in water at 35° C. for 270 seconds.

[0053] Then, the resultant poly(vinyl alcohol) was stretched to three times longer while being dyed in an aqueous solution containing Kayarus Supra Blue BWL, Sumilite Red 4B, Sumilite Supra Orange 2GL, and 10 g/L of anhydrous sodium sulfate at 35° C.

[0054] The resultant dyed film was stretched four times longer while being immersed in an aqueous solution containing 2.3 g/L of nickel acetate and 4.4 g/L of boric acid at 35° C. for 120 seconds. The resultant film was dried at room temperature for 3 minutes while being kept tensile. Then, the resultant film was heated at 110° C. for 3 minutes. As a result, a polarizing film having a transmittance of 35% and a degree of polarization of 99% was obtained.

<Production of a Functional Sheet>

[0055] An adhesive composition was prepared with 50 parts by mass of polyurethane prepolymer, 5 parts by mass of curing agent, and 60 parts by mass of ethyl acetate as a solvent. The adhesive composition was applied to the above-described polarizing film by use of a bar coater #24, and dried at 70° C. for 10 minutes. Then, a protective layer sheet produced above and the adhesive composition on the polarizing film were bonded together by a laminator. The adhesive composition was also applied to the side of the polarizing film of the resultant stacked sheet by substantially the same manner, and another protective layer sheet also produced above was bonded in substantially the same method. As a result, a functional sheet was obtained. The adhesive film had a post-curing thickness of 9 to 11 μm. The protective layer sheets each had a thickness of 0.3 mm.

<Bending>

[0056] A cut piece of the resultant functional sheet was bent by use of a concaved spherical surface bending form (radius of curvature: 66.81 mm; base curve: 7.932) provided with a vacuum-absorber and a silicone rubber sheet cover. Specifically, the cut piece of the functional sheet was put on a female silicone rubber sheet set to have a surface temperature of 145° C., and vacuum absorbing was started. Next, the cut piece of the functional sheet was pressurized, by a male form covered with a silicone rubber sheet, to be bent so as to have a spherical surface. Herein, the “base curve” is a curvature of a front surface of the lens, and is a value obtained by dividing 530 with a radius of curvature in units of millimeter.

<Formation of a Lens by Injection Molding>

[0057] The bent functional sheet was inserted into a mold for injection molding such that a convexed surface of the functional sheet would contact the mold. An aromatic polycarbonate resin (trade name: Iupilon CLS3400 produced by Mitsubishi Engineering-Plastics Corporation) was injection-molded to be put on a concaved surface of the functional sheet. As a result, a lens was produced. Regarding the conditions of the injection molding, the resin temperature was set to 300° C., the mold temperature was set to 80° C., and the pressure applied in a pressure keeping step was set to 60 MPa.

<Dyeing of the Lens>

[0058] 88 ml of BPI Brown #31100 (produced by Brain Power Inc.) as a disperse dye was incorporated into 1 L of pure water, and kept at 93° C. As a result, a brown dyeing liquid was obtained. The above-described polarizing lens was immersed in the brown dyeing liquid at 93° C. As a result, a colored lens was obtained. The spectral transmittance of the colored lens was measured by a spectrometer (trade name: UV-2700 produced by Shimadzu Corporation), and the difference between the pre-dyeing transmittance and the post-dyeing transmittance (post-dyeing amount of dye) was evaluated. Herein, the “transmittance” is the luminous transmittance in a two-degree field using a C light source, which is defined by JIS Z-8701.

<Discoloring with Alcohol>

[0059] The colored lens produced above was immersed in methanol for 30 minutes to evaluate the difference between the pre-dyeing transmittance and the post-discoloring transmittance (post-discoloring amount of dye). Then, the discoloring rates before and after the immersion were evaluated. Herein, the “discoloring rate” is defined as a value calculated by the expression “(post-dyeing amount of dye−post-discoloring amount of dye)/(post-dyeing amount of dye)×100”. The transmittance was measured by substantially the same method as that of, by use of the device used for, the evaluation on the coloring.

<Hard Coating>

[0060] The above-described colored lens was hard-coated by a dip coater. As a result, a hard-coated colored lens was obtained.

[0061] The values of the transmittance and the amount of dye before and after the dyeing, the transmittance and the amount of dye after the discoloring, and the discoloring rate are shown in Table 1 below.

Example 2

[0062] A colored lens was produced in substantially the same manner as in example 1 except that 40 parts by mass of the polyester resin (A), and 60 parts by mass of the aromatic polycarbonate resin (B) (trade name: Iupilon E-2000 produced by Mitsubishi Engineering-Plastics Corporation (same in the following examples), with respect to 100 parts by mass as a total of the polyester resin (A) and the aromatic polycarbonate resin (B), were mixed to form a protective layer sheet. Substantially the same evaluations as in example 1 were performed. The evaluation results are shown in Table 1.

Example 3

[0063] A colored lens was produced in substantially the manner as in example 1 except that 30 parts by mass of the polyester resin (A), and 70 parts by mass of the aromatic polycarbonate resin (B), with respect to 100 parts by mass as a total of the polyester resin (A) and the aromatic polycarbonate resin (B), were mixed to form a protective layer sheet. Substantially the same evaluations as in example 1 were performed. The evaluation results are shown in Table 1.

Example 4

[0064] A colored lens was produced in substantially the same manner as in example 1 except that 20 parts by mass of the polyester resin (A), and 80 parts by mass of the aromatic polycarbonate resin (B), with respect to 100 parts by mass as a total of the polyester resin (A) and the aromatic polycarbonate resin (B), were mixed to form a protective layer sheet. Substantially the same evaluations as in example 1 were performed. The evaluation results are shown in Table 1.

Example 5

[0065] A colored lens was produced in substantially the same manner as in example 1 except that 10 parts by mass of the polyester resin (A), and 90 parts by mass of the aromatic polycarbonate resin (B), with respect to 100 parts by mass as a total of the polyester resin (A) and the aromatic polycarbonate resin (B), were mixed to form a protective layer sheet. Substantially the same evaluations as in example 1 were performed. The evaluation results are shown in Table 1.

Example 6

[0066] A colored lens was produced in substantially the same manner as in example 1 except that a stacked body formed of the polyester resin (A) and the aromatic polycarbonate resin (B) produced by coextrusion was used as the protective layer sheet and that a functional sheet was produced by stacking the protective layer sheet and the adhesive composition applied to the polarizing film such that the aromatic polycarbonate resin layer of the protective layer sheet would be bonded with the adhesive composition.

[0067] Substantially the same evaluations as in example 1 were performed. The evaluation results are shown in Table 1.

Example 7

[0068] A colored lens was produced in substantially the same manner as in example 5 except that the protective layer sheet was set to have a thickness of 0.7 mm and that injection molding was not used to produce the lens. Substantially the same evaluations as in example 5 were performed. The evaluation results are shown in Table 1.

Comparative Example 1

[0069] A colored lens was produced in substantially the same manner as in example 1 except that the aromatic polycarbonate resin (B) was used instead of the polyester resin (A) to produce a protective layer sheet. Substantially the same evaluations as in example 5 were performed. The evaluation results are shown in Table 1.

TABLE-US-00001 TABLE 1 Comparative Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 example 1 Polyester resin (A) 100 40 30 20 10 100 10 0 (parts by mass) Polycarbonate resin (B) 0 60 70 80 90 0 90 100 (parts by mass) Pre-dyeing transmittance 33.5 32.9 34.6 33.0 33.5 34.0 35.2 34.0 (%) Post-dyeing transmittance 3.0 4.2 5.6 16.5 27.8 3.1 0.5 30.4 (%) Post-discoloring 4.1 5.2 6.8 18.5 29.5 4.1 0.8 33.2 transmittance (%) Post-dyeing amount 30 29 29 16 5.7 31 35 3.7 of dye Post-discoloring amount 29 28 28 14 4.0 30 34 0.9 of dye Discoloring ratio (%) 3.4 3.5 3.4 12 30 3.2 2.9 76

[0070] As shown in Table 1, in example 1, the post-dyeing transmittance is lower than the pre-dyeing transmittance by 30% or greater, which is preferable. In addition, the discoloring rate is close to 3%, which is also preferable. The scratch resistance is good because of the hard coating. In the present invention, the post-dyeing transmittance is lower than the pre-dyeing transmittance by, preferably 5% or greater, more preferably, 15% or greater, and especially preferably, 25% or greater. In the present invention, the discoloring rate is preferably 30% or less, more preferably 10% or less, and especially preferably 5% or less. By contrast, in comparative example 1, the post-dyeing transmittance is lower than the pre-dyeing transmittance only by 3.7%, and the discoloring rate is 76%, which is very high.