Adhesive Tape for Plastic Lens Molding and Method for Molding Plastic Lens

Abstract

The object of the invention is to provide an adhesive tape for plastic lens molding and a method for molding a plastic lens that can suppress the generation of defects such as wrinkles and whitening at the outer peripheral portion of the molded product when molding a high refractive index plastic lens by a short-time heating process. The solution to the problem is an adhesive tape for plastic lens molding, which is an adhesive tape for plastic lens molding having a base material and an adhesive layer formed on the surface of the base material. The adhesive layer contains an acrylic copolymer having a functional group and a crosslinking agent that reacts with the functional group. The acrylic copolymer has a weight average molecular weight (Mw) of 1,100,000 or more and a polydispersity (Mw / Mn) of 10.0 or less. The dissolution rate of the adhesive layer when immersed in toluene adjusted to a temperature of 80 °C for 2 hours is 48.0% or less. The deviation amount of the adhesive tape after 800 minutes in the creep test is 0.15 mm or more and 0.50 mm or less. The plastic lens has a refractive index of 1.59 or more.

Description

Technical Field

[0001] The present invention relates to an adhesive tape for plastic lens molding, and particularly to an adhesive tape for high refractive index plastic lens molding. Background Art

[0002] Thermosetting optical resins and monomers for plastic lens molding that have been put to practical use in applications such as spectacle lenses are roughly divided into the following two types: a polycondensation type typified by thiourethane resins; and a radical type typified by acrylic and vinyl compounds. Among them, thiourethane resins have advantages such as a high refractive index (e.g., refractive index of 1.59 or more) due to the inclusion of sulfur atoms and excellent impact resistance due to the formation of (thio)urethane bonds. By effectively utilizing these advantages, they have been widely popularized as optical resins mainly for high refractive index spectacle lenses.

[0003] The above-mentioned thiourethane resin can be obtained by curing a resin in which a (thio)urethane bond is formed by a condensation reaction between a polythiol component and a polyisocyanate component. In order to carry out polymerization while maintaining optical uniformity, it is necessary to carry out polymerization curing while slowly raising the temperature from room temperature to a high temperature over a long period of time. For example, in the case of polymerizing and molding a high refractive index spectacle lens, generally, in order to carry out polymerization curing while slowly raising the temperature from room temperature around 20 to 30°C to a high temperature around 120 to 130°C, a heating and curing process as long as 24 hours or more is required. Therefore, although the thiourethane resin is excellent in performance as a resin for high refractive index plastic lens molding, there is still room for improvement in productivity.

[0004] In view of the above problems of productivity, Patent Document 1 discloses, for the purpose of providing spectacle lenses excellent in optics, physical properties, and productivity, a resin obtained by polymerizing and curing a composition containing the following components, which is suitable for high refractive index spectacle lenses. In addition, regarding the curing of this composition, short-time curing can be carried out by heating. The composition contains a component obtained by prepolymerizing a polythiol compound having a specific structure with a polyisocyanate compound, a component composed of a (meth)acrylate compound having a specific structure, and a component composed of a compound capable of copolymerizing with them. And regarding the short-time curing, it is described in the examples that: the composition is injected into a concave lens mold, heated and cured from 50°C to 130°C for 3 hours, further heated and cured at 130°C for 1 hour, allowed to cool to room temperature, and then the lens is demolded from the glass mold to obtain a colorless and transparent concave lens. It is also known that: compared with the above-mentioned conventional heating and curing process, the curing start temperature is high and the heating time is also short.

[0005] In addition, Patent Document 2 discloses a batch process including the following steps as a process for molding an optical article for the main purpose of reducing optical defects. The steps are: a step of introducing (i) a dithiol component or (ii) a polyisocyanate component into a reaction vessel; a step of adding a first catalyst of organotin halide to form a first reaction mixture; a step of heating the first reaction mixture; a step of introducing a second catalyst of tertiary amine into the first reaction mixture; a step of mixing the polyisocyanate (ii) in the reaction vessel containing the first reaction mixture when initially adding the dithiol (i), or mixing the dithiol (i) in the first reaction mixture when initially adding the polyisocyanate (ii) to form a second reaction mixture; a step of filling the second reaction mixture into a mold, preparing a filled mold, and forming a molded optical article. And regarding this batch process, it is described in the examples that: the second reaction mixture is filled into the mold, the curing cycle starts at 50°C, rises to 130°C (0.11°C / min) in 12 hours, the sample is held at 130°C for 6 hours, and then cooled to 70°C in 1 hour to obtain a cured lens. And it is known that: compared with the above-mentioned conventional temperature-rising curing process, the curing start temperature is high and the temperature-rising time is also short.

[0006] On the other hand, as a method for molding a plastic lens, a method of molding by a casting polymerization method using a pair of glass molds (molds) and an adhesive tape for sealing is known. In this method, a pair of glass molds are arranged opposite to each other at a predetermined interval. Then, the adhesive tape is adhered along the circumferential direction to the entire circumference of the outer peripheral surfaces of the pair of glass molds to produce a polymerization unit. Thus, the space between the glass molds is sealed by the adhesive tape. Then, a resin injection nozzle is inserted into this adhesive tape, and a liquid resin (polymerizable monomer, polymerizable prepolymer) is injected into the space between the glass molds and filled. Then, the resin is polymerized and cured by heating, light irradiation, etc. to obtain a plastic lens. In order to obtain a high-quality plastic lens by this method, the adhesive tape for plastic lens molding is required to have the property of not causing appearance defects (such as whitening, wrinkles, etc.) at the outer peripheral portion of the plastic lens.

[0007] Patent Document 3 describes an adhesive tape for manufacturing a plastic lens, which has a pressure-sensitive adhesive layer with a soluble fraction of 30% or less in toluene (20°C). The examples describe a process in which a diethylene glycol diallyl carbonate-based liquid lens raw material is slowly heated from 40°C to 110°C over 35 hours to polymerize and cure the raw material, and then allowed to cool to room temperature, thereby obtaining a lens that is free of turbidity, colorless and transparent, and has no residual adhesive component on the side. However, when this adhesive tape for manufacturing a plastic lens is used to mold a high-refractive-index plastic lens by the above-mentioned short-time heating process, that is, a process with a high curing start temperature and a short heating time, a colorless and transparent lens is not necessarily obtained. Under high-temperature conditions, the amount of the pressure-sensitive adhesive layer eluted from the adhesive layer becomes larger relative to the lens raw material, and sometimes whitening occurs at the outer peripheral portion of the obtained molded product. In addition, if highly crosslinked and structured, the holding force of the pressure-sensitive adhesive becomes larger than required. For example, it is difficult to alleviate the influence of the curing shrinkage of a high-refractive-index plastic lens raw material such as a thiourethane resin, that is, the adhesive tape is likely to wrinkle, and sometimes wrinkles occur on the side of the plastic lens. Therefore, there is room for improvement in simultaneously suppressing the occurrence of whitening and wrinkles.

[0008] Generally, the whitening of a plastic lens refers to a state in which the plastic lens appears white and turbid when observed while irradiating light.

[0009] Prior Art Documents

[0010] Patent Documents

[0011] Patent Document 1: Japanese Patent Laid-Open No. 10-114825

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2018-525499

[0013] Patent Document 3: Japanese Patent Laid-Open No. 5-255650 Summary of the Invention

[0014] Problems to be Solved by the Invention

[0015] The present invention has been made in view of the above problems, and an object thereof is to provide an adhesive tape for molding a plastic lens and a method for molding a plastic lens that can suppress the occurrence of defects such as wrinkles and whitening at the outer peripheral portion of a molded product and the residual adhesive on the adherend when the adhesive tape is peeled off when molding a high-refractive-index plastic lens by a short-time heating process.

[0016] Means for Solving the Problems

[0017] For this purpose, the inventors of the present invention conducted in-depth research on the adhesive layer of the adhesive tape for forming high refractive index plastic lenses, and found that: when forming a high refractive index plastic lens by a short-time heating process, in order to suppress the generation of defects such as wrinkles and whitening at the outer peripheral portion of the formed product, first of all, it is important to set the weight average molecular weight (Mw) and the polydispersity of the molecular weight (Mw / Mn) of the polymer (acrylic copolymer) used in the adhesive within an appropriate range. Moreover, if an acrylic adhesive designed such that the dissolution rate when immersed in toluene adjusted to a temperature of 80 °C for 2 hours is 48.0% or less, and the deviation amount in the creep test (temperature 40 °C, load 0.5 kg) is 0.15 mm or more and 0.50 mm or less is used as the adhesive layer, it is possible to suppress the generation of whitening, wrinkles, bubbles at the outer peripheral portion of the obtained high refractive index plastic lens formed product, and the adhesion residue of the adhesive tape on the plastic lens and the side surface of the mold when the adhesive tape is peeled off, thus completing the present invention.

[0018] That is, compared with the conventional heating and curing process, in the case of using a short-time heating and curing process with a high curing start temperature and a short heating time when forming a high refractive index plastic lens, the adhesive layer in the adhesive tape used as the sealing tape will be suddenly exposed for several hours in the liquid to viscous and high-temperature polymerizable monomers and prepolymers for plastic lenses that are not fully cured in the initial stage of polymerization. In particular, since the reaction between polythiol and polyisocyanate is slower than that of other monomers, the liquid to viscous state lasts longer. Therefore, the risk of a part of the adhesive composition dissolving from the adhesive layer into plastic lens materials such as monomers and prepolymers is sharply increased compared with the conventional heating and curing process that takes a long time to slowly heat up from room temperature to a high temperature. It is considered that if the dissolution amount reaches a certain amount or more, whitening is likely to occur at the outer peripheral portion of the obtained plastic lens formed product. However, if this problem is to be solved only by highly crosslinking and structuring the adhesive layer, the whitening is suppressed, but as described above, the adhesive layer becomes harder than necessary, and it is difficult to relieve the influence of the curing shrinkage of the high refractive index plastic lens raw material. Therefore, wrinkles are likely to occur on the side surface of the plastic lens.

[0019] Therefore, in order to simultaneously solve the above-mentioned whitening generation and wrinkle generation, which are in a trade-off relationship, during the molding of a high refractive index plastic lens, the present inventors first focused on the weight average molecular weight (Mw) and the polydispersity of the molecular weight (Mw / Mn) of the acrylic copolymer used in the adhesive layer and conducted research. As a result, it was found that if the weight average molecular weight (Mw) of the acrylic copolymer is increased to 1,100,000 or more and the polydispersity of the molecular weight (Mw / Mn) is set to 10.0 or less, the low molecular weight components of the acrylic copolymer and the low molecular weight components of the homopolymer generated by non-copolymerization, specifically, the low molecular weight components with a weight average molecular weight of less than 10,000, become extremely small. Therefore, even if the highly crosslinked structure of the adhesive layer is not achieved to a level higher than required, the amount of elution from the adhesive layer to the lens material can be suppressed, and the risk of whitening generation can be significantly reduced. On the other hand, it was found that since the highly crosslinked structure is not achieved, the adhesive layer does not harden to a level higher than required, and the generation of wrinkles can be suppressed. Further, due to the large molecular weight and the small polydispersity of the molecular weight, it has both large cohesion and appropriate softness, and the adhesive residue can also be suppressed.

[0020] The present invention includes the following constitution. That is, the adhesive tape for plastic lens molding according to the present invention is an adhesive tape for plastic lens molding having a base material and an adhesive layer formed on the surface of the base material, and is characterized in that

[0021] The above-mentioned adhesive layer contains an acrylic copolymer having a functional group and a crosslinking agent that reacts with the functional group,

[0022] The above-mentioned acrylic copolymer has a weight average molecular weight (Mw) of 1,100,000 or more and a polydispersity of the molecular weight (Mw / Mn) of 10.0 or less,

[0023] The elution rate of the above-mentioned adhesive layer when immersed in toluene adjusted to a temperature of 80 °C for 2 hours is 48.0% or less, and

[0024] The deviation amount of the above-mentioned adhesive tape after 800 minutes in the creep test (temperature 40 °C, load 0.5 kg) is 0.15 mm or more and 0.50 mm or less,

[0025] The above-mentioned plastic lens has a refractive index of 1.59 or more.

[0026] In the above manner, the above-mentioned acrylic copolymer has a carboxyl group as a functional group, and the above-mentioned crosslinking agent is preferably a polyisocyanate-based compound.

[0027] In addition, the above acrylic copolymer has an acid value of 5.0 to 75.0 mgKOH / g, and the ratio (NCO / COOH) of the equivalent of the isocyanate group (NCO) in the above polyisocyanate compound to the equivalent of the carboxyl group (COOH) in the above acrylic copolymer is preferably 0.20 to 0.80.

[0028] In addition, further, the monomer as the raw material of the above acrylic copolymer preferably contains an (alkyl) acrylate having an alkyl group with 5 to 18 carbon atoms.

[0029] In addition, further, the dissolution rate of the above adhesive layer when immersed in toluene adjusted to a temperature of 80°C for 2 hours is preferably 38.0% or less.

[0030] In addition, further, the deviation amount of the above adhesive tape after 800 minutes in the creep test is preferably 0.20 mm or more and 0.50 mm or less.

[0031] In addition, further, the above plastic lens is preferably a thiourethane resin.

[0032] In addition, further, the above substrate is preferably a composite substrate formed by laminating a sheet-like first substrate, an inorganic thin film layer, an adhesive layer, and a sheet-like second substrate in this order.

[0033] In addition, further, the above adhesive tape preferably has a water vapor transmission rate according to JIS K 7129 of 1.5 g / (m 2 ·24h) or less.

[0034] Furthermore, the plastic lens molding method according to the present invention is characterized by having the following steps: a chamber forming step of relatively disposing a pair of molds with a predetermined interval therebetween, pasting the adhesive tape for plastic lens molding of the present invention on the outer peripheral portions of the above two molds, and sealing the opening of the space formed between the above two molds to form a chamber for filling a polymerizable raw material for a plastic lens; a polymerizable raw material filling step of filling the above chamber with a polymerizable raw material for a plastic lens having a refractive index of 1.59 or more; and a polymerization step of polymerizing the above polymerizable raw material.

[0035] In addition, further, the polymerization conditions of the above polymerization step preferably include: a polymerization start temperature of 45°C or more and 65°C or less, a polymerization final temperature of 130°C or more and 150°C or less, and a heating rate to reach the above polymerization final temperature of 0.10°C / minute or more and 0.45°C / minute or less.

[0036] In addition, further, the above plastic lens is preferably a thiourethane resin.

[0037] Advantages of the Invention

[0038] According to the present invention, it is possible to provide an adhesive tape for molding a high-refractive-index plastic lens and a method for molding a plastic lens, which can suppress the generation of defects such as whitening and wrinkling at the outer peripheral portion of the molded product and the adhesive residue on the adherend when the adhesive tape is peeled off during the molding of a high-refractive-index plastic lens by a short-time heating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 FIG. is a cross-sectional view showing the structure of an adhesive tape according to an embodiment of the present invention.

[0040] Figure 2 FIG. is a perspective view showing an example of the structure of a glass mold used in the method for molding a plastic lens according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0041] (Configuration of the Adhesive Tape)

[0042] The adhesive tape of the present invention has a base material and an adhesive layer formed on the surface of the base material. The base material is a member that supports the adhesive layer. The base material refers to a film-like material having tensile strength, heat resistance, and flexibility. The base material may be composed of a single layer or a composite material having multiple layers.

[0043] Figure 1 FIG. is a cross-sectional view showing the structure of an adhesive tape according to an embodiment of the present invention. The adhesive tape 1 of the present embodiment is used in the application of manufacturing a plastic lens for, for example, spectacle lenses. The adhesive tape 1 of the present embodiment preferably has a structure in which a composite base material 2 and an adhesive layer 3 are laminated. Further, the composite base material 2 preferably includes a first laminate 10 having an inorganic thin film layer 5 formed on a first base material 4 and a second laminate 20 having an adhesive layer 6 formed on a second base material 7 laminated together. In addition, in the present embodiment, the adhesive layer 3 is formed on the surface of the composite base material 2 on the side of the first base material 4, but the adhesive layer 3 may also be formed on the surface of the composite base material 2 on the side of the third base material 7.

[0044] In the adhesive tape 1 of the present embodiment, a tackifier coating (not shown) for improving the adhesion may be provided between the composite base material 2 (first base material 4) and the adhesive layer 3, and between the first base material 4 and the inorganic thin film layer 5 as needed.

[0045] <Composite Base Material>

[0046] As described above, the composite base material 2 of the present embodiment has a structure in which the first base material 4, the inorganic thin film layer 5, the adhesive layer 6, and the second base material 7 are laminated in this order by laminating the first laminate 10 and the second laminate 20.

[0047] Hereinafter, each layer constituting the composite base material 2 will be described.

[0048] [First base material]

[0049] The material of the first base material 4 used in the adhesive tape 1 of the present embodiment is not particularly limited. For example, a base material made of plastic, metal, etc. can be used.

[0050] Among them, a base material mainly composed of polyethylene terephthalate (PET) is particularly preferably used. In addition, as the first base material 4, for example, resin films such as polybutylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, biaxially stretched polypropylene, polyimide, aromatic polyamide, polycycloolefin, and fluororesin can also be used.

[0051] Details will be described later, but an inorganic thin film layer 5 containing, for example, silicon, aluminum, etc. is provided on the first base material 4 of the present embodiment.

[0052] When polyethylene terephthalate (PET) is used as the first base material 4, it is preferable to set the thickness of the first base material 4 in the range of 9 μm or more and 25 μm or less.

[0053] When the thickness of the first base material 4 is less than 9 μm, the film thickness unevenness of the first base material 4 in the width direction of the adhesive tape 1 becomes larger, and wrinkles, folds, etc. are likely to occur when the inorganic thin film layer 5 is laminated on the first base material 4. As a result, the water vapor transmission rate of the adhesive tape 1 sometimes becomes partially high, and there is a tendency for plastic lenses manufactured using the adhesive tape 1 to easily generate bubbles and whitening.

[0054] In addition, in the manufacturing process of the adhesive tape 1 described later, the first laminate 10 formed by laminating the inorganic thin film layer 5 on the first base material 4 is usually wound in such a manner that the side of the inorganic thin film layer 5 becomes the outer periphery. Here, when the thickness of the first base material 4 exceeds 25 μm, the outer periphery side (the side of the inorganic thin film layer 5) of the first laminate 10 is more likely to elongate when winding the first laminate 10 compared to the case where the thickness of the first base material 4 is 25 μm or less. As a result, the inorganic thin film layer 5 elongates in the first laminate 10, and thus cracks (crazing) sometimes occur in the entire inorganic thin film layer 5. And, in the adhesive tape 1 in which such cracks in the inorganic thin film layer 5 occur, the water vapor transmission rate sometimes becomes high, and there is a tendency for plastic lenses manufactured using the adhesive tape 1 to easily generate bubbles and whitening.

[0055] [Second base material]

[0056] The material of the second base material 7 is not particularly limited in the same manner as the first base material 4. For example, a base material made of plastic, metal, etc. can be used.

[0057] Among them, it is particularly preferable to use a substrate mainly composed of polyethylene terephthalate (PET). In addition, as the second substrate 7, similar to the first substrate 4, resin films such as polybutylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, biaxially stretched polypropylene, polyimide, aromatic polyamide, polycycloolefin, and fluororesin can be used, for example.

[0058] When using polyethylene terephthalate (PET) as the second substrate 7, it is preferable to set the thickness of the second substrate 7 within the range of 18 μm or more and 38 μm or less.

[0059] When the thickness of the second substrate 7 is too small, the rigidity of the second substrate 7 is likely to decrease, and there is a tendency that it is difficult to maintain the interval between the two molds 50 (refer to Figure 2 ) in the manufacturing process of the plastic lens described later. In addition, when the thickness of the second substrate 7 is too small, sometimes it cannot completely resist the force of the expansion of the plastic lens molding resin (refers to monomers and / or oligomers) 100 injected between the mold 50 and the adhesive tape 1 to form the chamber C (refer to Figure 2 ), resulting in rupture, cutting, etc. of the adhesive tape 1, and air invades into the chamber C. Further, when the thickness of the second substrate 7 is too small, it is feared that it cannot completely resist the force of the shrinkage of the plastic lens molding resin 100 in the chamber C, causing the adhesive tape 1 to be stretched in a manner of being pushed toward the center of the chamber C to generate wrinkles, and wrinkles (tape wrinkles) caused by the wrinkles of the adhesive tape 1 are generated on the formed lens.

[0060] On the other hand, when the thickness of the second substrate 7 is too large, the rigidity of the second substrate 7 is likely to increase, and there is a tendency that the stretchability of the adhesive tape 1 decreases. In addition, the total thickness of the adhesive tape 1 becomes larger, and in the manufacturing process of the plastic lens described later, when winding the adhesive tape 1 around the mold 50, sometimes gaps are generated between the adhesive tapes 1 at the overlapping lap portions of the adhesive tape 1, and the resin 100 leaks from the chamber C.

[0061] In addition, when considering the relationship between the first substrate 4 and the second substrate 7, it is preferable to set the thickness of the second substrate 7 within the range of 2 times or more and 3 times or less the thickness of the first substrate 4. By making the first substrate 4 and the second substrate 7 have such a relationship, during the winding of the adhesive tape 1, in the manufacturing process of the plastic lens, etc., it is possible to suppress the load applied to the inorganic thin film layer 5 provided between the first substrate 4 and the second substrate 7 due to the deformation of the adhesive tape 1. Further, by making the first substrate 4 and the second substrate 7 have such a relationship, the rigidity and stretchability of the entire adhesive tape 1 can be within a range preferable for the molding use of the plastic lens. Thereby, in the manufacturing process of the plastic lens described later, it is possible to suppress the generation of moisture mixing into the chamber C, resin 100 leaking from the chamber C, etc.

[0062] Furthermore, the total thickness of the combined first substrate 4 and second substrate 7 is preferably in the range of 27 μm or more and 60 μm or less. By setting the total thickness of the combined first substrate 4 and second substrate 7 within such a range, in the manufacturing process of the plastic lens described later, it is possible to suppress liquid leakage caused by the step difference at the overlapping portion where the adhesive tape 1 overlaps, and at the same time, it is possible to suppress breakage or peeling of the adhesive tape 1 due to deformation such as shrinkage of the resin 100.

[0063] [Inorganic thin film layer]

[0064] The inorganic thin film layer 5 is composed of an inorganic substance and is provided to improve the moisture resistance and gas barrier properties of the adhesive tape 1 and suppress the permeation of moisture in the adhesive tape 1.

[0065] Examples of the inorganic substance constituting the inorganic thin film layer 5 include silicon, aluminum, magnesium, zinc, tin, nickel, titanium, hydrocarbons, etc., or their oxides, carbides, nitrides, or mixtures thereof. Among them, silicon oxide, silicon nitride, aluminum oxide, aluminum nitride, and substances mainly composed of hydrocarbons such as diamond-like carbon are preferably used. In particular, as the inorganic thin film layer 5, from the aspect of being able to suppress the permeation of moisture in the adhesive tape 1, silica and alumina are more preferably used.

[0066] It should be noted that the above inorganic substances can be used alone or in combination of two or more.

[0067] As a method for forming the inorganic thin film layer 5, known methods such as evaporation coating method and coating method can be used. Among them, from the aspect of obtaining a thin film with high moisture resistance and gas barrier properties and uniformity, the evaporation coating method is preferably used. The evaporation coating method includes methods such as PVD (Physical Vapor Deposition) including vacuum evaporation, ion plating, sputtering, etc., and CVD (Chemical Vapor Deposition).

[0068] The thickness of the inorganic thin film layer 5 is, for example, in the range of 0.1 nm to 500 nm, preferably in the range of 0.5 nm to 40 nm. By setting the thickness of the inorganic thin film layer 5 within the above range, it is possible to suppress the permeation of moisture, and in addition, it is possible to suppress the occurrence of breakage, etc. in the inorganic thin film layer 5. In addition, by setting the thickness of the inorganic thin film layer 5 within the above range, it is possible to suppress the reduction of the transparency of the adhesive tape 1.

[0069] [Adhesive layer]

[0070] The adhesive layer 6 is provided to bond the inorganic thin film layer 5 in the first laminate 10 and the second base material 7 in the second laminate 20. The adhesive layer 6 is formed of an adhesive. As the adhesive for forming the adhesive layer 6, for example, a polyester-based adhesive cured with an isocyanate-based curing agent can be used. However, the adhesive used for the adhesive layer 6 is not limited thereto, and known materials such as an epoxy-based adhesive and a polyether-based adhesive can be used.

[0071] As the thickness of the adhesive layer 6, a range of 1 μm or more and 10 μm or less is preferable. When the thickness of the adhesive layer 6 is too small, the adhesive strength between the adhesive layer 6 and the inorganic thin film layer 5 tends to become insufficient. Also, when the adhesive strength with the inorganic thin film layer 5 decreases, breakage of the inorganic thin film layer 5 occurs, and the water vapor transmission rate of the adhesive tape 1 easily increases. On the other hand, when the thickness of the adhesive layer 6 is too large, the total thickness of the adhesive tape 1 tends to become thick. Also, when the total thickness of the adhesive tape 1 becomes thick, in the manufacturing process of the plastic lens described later, when winding the adhesive tape 1 around the mold 50, sometimes a gap is generated between the adhesive tapes 1 at the overlapping portion where the adhesive tapes 1 overlap, resulting in leakage of the resin 100 from the chamber C.

[0072] <Adhesive layer>

[0073] The adhesive layer 3 of the present embodiment contains an acrylic copolymer as the main polymer of the adhesive. Hereinafter, the acrylic copolymer will be described in detail.

[0074] [Acrylic copolymer]

[0075] The acrylic copolymer refers to a copolymer obtained by polymerizing a monomer mixture containing a monomer having a (meth)acryloyl group. The monomer mixture contains, for example, an alkyl (meth)acrylate and an ethylenically unsaturated monomer having a functional group.

[0076] The weight average molecular weight (Mw) of the above acrylic copolymer is 1,100,000 or more, and the polydispersity (Mw / Mn) of the molecular weight is 10.0 or less. The values of the weight average molecular weight (Mw) and the number average molecular weight (Mn) are polystyrene conversion values measured by gel permeation chromatography.

[0077] If the above-mentioned weight-average molecular weight (Mw) is less than 1,100,000, the content of low-molecular-weight components with a molecular weight less than 10,000 will necessarily increase. In the manufacturing process of a high-refractive-index plastic lens by a short-time heating process, the risk of a part of the adhesive layer 3 dissolving into the resin for plastic lens molding increases, and whitening may occur at the outer peripheral part of the obtained plastic lens molded product. On the other hand, the upper limit of the weight-average molecular weight (Mw) is not particularly limited, but it is preferably 2,000,000 or less. If the weight-average molecular weight (Mw) exceeds 2,000,000, it may be difficult to achieve uniform coatability due to an increase in the viscosity of the adhesive composition solution. In addition, the stress relaxation property of the adhesive layer 3 decreases, and wrinkles may occur on the side surface of the obtained plastic lens molded product. The above-mentioned weight-average molecular weight (Mw) is preferably in the range of 1,200,000 or more and 1,500,000 or less.

[0078] If the polydispersity (Mw / Mn) of the above-mentioned molecular weight exceeds 10.0, the content of low-molecular-weight components with a molecular weight less than 10,000 will necessarily increase. In the manufacturing process of a high-refractive-index plastic lens by a short-time heating process, the risk of a part of the adhesive layer 3 dissolving into the resin for plastic lens molding increases, and whitening may occur at the obtained plastic lens molded product's outer peripheral part. On the other hand, the lower limit of the polydispersity (Mw / Mn) of the molecular weight is not particularly limited, but it is preferably 5.0 or more. If the polydispersity (Mw / Mn) of the molecular weight is less than 5.0, in the case where the weight-average molecular weight (Mw) is particularly large, the stress relaxation property of the adhesive layer 3 decreases, and wrinkles may occur on the side surface of the obtained plastic lens molded product.

[0079] By setting the weight-average molecular weight (Mw) and the polydispersity (Mw / Mn) of the above-mentioned acrylic copolymer within the above ranges, it is possible to substantially exclude the low-molecular-weight components of the acrylic copolymer, which is the main polymer of the adhesive. Therefore, even if a highly crosslinked structure beyond the required level cannot be achieved, in the manufacturing process of a high-refractive-index plastic lens by a short-time heating process, the risk of a part of the adhesive layer 3 dissolving into the resin 100 for plastic lens molding can be significantly suppressed. Further, the adhesive layer 3 does not harden beyond the required level and can maintain an appropriate stress relaxation property. Therefore, it is also possible to alleviate the influence of the curing shrinkage of the high-refractive-index plastic lens. As a result, whitening at the peripheral part of the plastic lens molded product and the generation of wrinkles on the side surface can be suppressed. In addition, the cohesion of the adhesive layer 3 is also high. Therefore, the resin 100 does not leak out of the lens chamber C and polymerize and cure, and the generation of air bubbles and notches at the outer peripheral part of the obtained plastic lens can be suppressed. Moreover, the generation of adhesive residue on the side surfaces of the mold 50 and the plastic lens molded product when the adhesive tape 1 is peeled off from the mold 50 after polymerization and curing can also be suppressed.

[0080] The above-mentioned (meth)acrylic acid alkyl esters are not particularly limited. From the viewpoints of reducing the solution viscosity of the polymerized acrylic copolymer and optimizing the deviation amount in the creep test, the number of carbon atoms in the alkyl group is preferably in the range of 5 to 18, more preferably in the range of 8 to 14. If the number of carbon atoms in the alkyl group is large, the functional groups of the acrylic copolymer described below will be moderately masked by the alkyl group with a large number of carbon atoms, and an extremely highly crosslinked structure will not be formed. Therefore, it is easy to have moderate stress relaxation properties. As a result, it is easy to set the deviation amount in the creep test within an appropriate range. Examples of the (meth)acrylic acid alkyl ester include 2-ethylhexyl acrylate (number of carbon atoms in the alkyl group [hereinafter, simply referred to as the number of carbon atoms]: 8, Tg of the homopolymer [hereinafter, simply referred to as Tg]: -70 °C), isodecyl acrylate (number of carbon atoms: 10, Tg: -60 °C), isoundecyl acrylate (number of carbon atoms: 11), isododecyl acrylate (number of carbon atoms: 12), isotridecyl acrylate (number of carbon atoms: 13), isomyristyl acrylate (number of carbon atoms: 14, Tg: -56 °C), decyl methacrylate (number of carbon atoms: 10, Tg: -74 °C), dodecyl acrylate (number of carbon atoms: 12, Tg: -8 °C), dodecyl methacrylate (number of carbon atoms: 12, Tg: -65 °C), tridecyl methacrylate (number of carbon atoms: 13, Tg: -40 °C), isodecyl methacrylate (number of carbon atoms: 10, Tg: -41 °C), undecyl methacrylate (number of carbon atoms: 11), tetradecyl methacrylate (number of carbon atoms: 14, Tg: -15 °C), etc.

[0081] The above-mentioned ethylenically unsaturated monomer having a functional group is not particularly limited. Examples thereof include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid, hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, and epoxy group-containing monomers such as glycidyl (meth)acrylate and allyl glycidyl ether. From the viewpoint of imparting moderate stress relaxation properties to the adhesive layer 3, the functional group possessed by the ethylenically unsaturated monomer is preferably a carboxyl group.

[0082] Examples of other monomers that can be contained in the monomer mixture include acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, vinyl propionate, vinyl chloride, alkyl vinyl ether, dimethylaminoethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, and methoxytriethylene glycol (meth)acrylate.

[0083] In the above acrylic polymer, the content ratios of the (meth)acrylic acid alkyl ester monomer, the ethylenically unsaturated monomer having a functional group, and other monomers are preferably 60 to 99.3% by mass for the (meth)acrylic acid alkyl ester monomer, 0.7 to 10% by mass for the ethylenically unsaturated monomer having a functional group, and 0 to 39.3% by mass for other monomers, and more preferably 70 to 99% by mass for the (meth)acrylic acid alkyl ester monomer, 1 to 5% by mass for the ethylenically unsaturated monomer having a functional group, and 0 to 29% by mass for other monomers.

[0084] The functional group of the above acrylic copolymer is a functional group as a crosslinking point to be crosslinked by a crosslinking agent described later. This functional group is introduced as a side chain by copolymerizing an ethylenically unsaturated monomer having a functional group. Among these functional groups, from the viewpoints of reactivity and versatility, a carboxyl group and a hydroxyl group having active hydrogen are preferred, and from the viewpoint of simultaneously suppressing the generation of whitening and wrinkles in the obtained plastic lens, a carboxyl group is more preferred. When the functional group is a carboxyl group, the acid value of the acrylic copolymer is preferably in the range of 5.0 to 75.0 mgKOH / g, and more preferably in the range of 7.0 to 38.0 mgKOH / g. In addition, when the functional group is a hydroxyl group, the hydroxyl value of the acrylic copolymer is preferably in the range of 3.0 to 48.0 mgKOH / g, and more preferably in the range of 4.8 to 24.0 mgKOH / g.

[0085] If the amount (acid value, hydroxyl value) of the functional group of the above acrylic copolymer is less than the lower limit value of the above range, when the addition amount of the crosslinking agent described later is small, since the crosslinking of the adhesive layer 3 becomes insufficient, in the manufacturing process of the high refractive index plastic lens by a short-time heating process, the risk of a part of the adhesive layer 3 dissolving into the resin for plastic lens molding becomes high, and whitening may occur in the peripheral part of the obtained plastic lens molded product. In addition, the cohesion of the adhesive layer 3 also becomes insufficient, and when the adhesive tape 1 is peeled off from the mold 50 after polymerization and curing, adhesive residue may occur on the side of the mold 50 and the plastic lens molded product. On the other hand, if the amount (acid value, hydroxyl value) of the above functional group exceeds the upper limit value of the above range, the adhesive layer 3 will form a highly crosslinked structure more than required and become too hard, so the stress relaxation property of the adhesive layer 3 is reduced, and wrinkles may occur on the side of the obtained plastic lens molded product. In addition, when the addition amount of the crosslinking agent described later is large, the adhesive force of the adhesive layer 3 is reduced, and the fixing force to the mold 50 may deteriorate.

[0086] The above acrylic copolymer can be produced by a conventional polymerization method. For example, according to the target monomer composition, a polymerization method such as solution polymerization, photopolymerization, bulk polymerization, suspension polymerization or emulsion polymerization can be applied to a monomer mixture containing a predetermined amount of the required monomers to produce it. In this process, if necessary, an appropriate polymerization initiator, molecular weight regulator, chain transfer agent, etc. can be used together. From the viewpoints of versatility and workability, polymerization by solution polymerization is preferred.

[0087] In the case of solution polymerization, specifically, a monomer component, a chain transfer agent, a polymerization solvent, etc. as required are added into a reaction vessel, and in an inert gas atmosphere such as nitrogen, a polymerization initiator is added. The reaction start temperature is usually set in the range of 40 to 100 °C, and the maintenance temperature of this reaction system is usually set in the range of 50 to 90 °C, and the reaction is carried out for 2 to 20 hours. In addition, during the polymerization reaction, a polymerization initiator, a chain transfer agent, a monomer component, and a polymerization solvent can be appropriately added additionally.

[0088] Among the above polymerization solvents, from the viewpoint of high molecular weight during the polymerization of the acrylic copolymer, an organic solvent that hardly undergoes chain transfer during the polymerization reaction is preferably used, such as esters and ketones. In particular, from the viewpoints of the solubility of the acrylic copolymer and the ease of the polymerization reaction, ethyl acetate, methyl ethyl ketone, acetone, etc. are preferably used.

[0089] As the polymerization initiator, organic peroxides, azo compounds, etc. that can be used in ordinary solution polymerization can be used. Among these polymerization initiators, during the polymerization of the acrylic copolymer, an azo compound that hardly undergoes a hydrogen abstraction reaction is preferably used as the polymerization initiator in the initial stage of polymerization, and an organic peroxide with good initiator efficiency is preferably used as the polymerization initiator in the later stage of polymerization. Thus, by changing the types of polymerization initiators added in the initial and later stages of polymerization, an acrylic copolymer having a high weight average molecular weight (Mw) and a moderate polydispersity (Mw / Mn) of molecular weight can be suitably synthesized.

[0090] [Crosslinking agent]

[0091] In order to crosslink the above acrylic polymer, the adhesive layer 3 of the present embodiment contains a crosslinking agent that reacts with the functional groups of an ethylenically unsaturated monomer having a functional group. As the above crosslinking agent, for example, polyisocyanate compounds, melamine compounds, aziridine compounds, epoxy compounds, oxazoline compounds, carbodiimide compounds, metal compounds such as metal complexes, amino-containing compounds, etc. can be cited. Among these crosslinking agents, polyisocyanate compounds are preferably used from the viewpoints of reactivity, heat resistance imparted, and versatility.

[0092] Examples of the polyisocyanate compound described above include isocyanate monomers such as toluene diisocyanate, chlorobenzene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate, isocyanate compounds obtained by adding trimethylolpropane or the like to these isocyanate monomers, isocyanurate compounds, biuret-type compounds, and polyurethane prepolymer-type isocyanates obtained by addition reaction with polyether polyol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. In addition, commercially available isocyanate-based crosslinking agents can also be used, such as CORONATE L-45 (trade name) manufactured by Soken Chemical & Engineering Co., Ltd., TAKENATE A-56 (trade name) manufactured by Mitsui Chemicals, Inc., etc. These polyisocyanate compounds can be used alone or in combination of two or more.

[0093] From the viewpoints of simultaneously suppressing whitening and wrinkle generation of the obtained plastic lens and suppressing adhesive residue, the content of the above crosslinking agent may be appropriately adjusted so that the dissolution rate of the adhesive layer when the adhesive tape 1 is immersed in toluene adjusted to a temperature of 80 °C for 2 hours is 48% or less, and the deviation amount after 800 minutes in the creep test is 0.15 mm or more and 0.50 mm or less. Since there is also a balance with the amount of functional groups in the above acrylic copolymer, it cannot be generalized, but it is preferably adjusted so that the content of the above crosslinking agent is, for example, in the range of 1.3 to 5.0 parts by mass with respect to 100 parts by mass of the acrylic copolymer. The equivalent ratio of the isocyanate group of the crosslinking agent to the active hydrogen-containing functional group of the acrylic copolymer, that is, if expressed as the equivalent ratio NCO / COOH of NCO (isocyanate group of the crosslinking agent) to COOH (carboxyl group of the acrylic copolymer) and NCO / OH of NCO (isocyanate group of the crosslinking agent) to OH (hydroxyl group of the acrylic copolymer), is preferably in the range of 0.20 to 0.80.

[0094] [Thickness]

[0095] The thickness of the adhesive layer 3 is preferably in the range of 10 μm or more and 50 μm or less. When the thickness of the adhesive layer 3 is less than 10 μm, the fixing force to the mold 50 and the adhesive force of the overlapping portion of the adhesive tapes 1 are reduced, and the resin 100 leaks from the lens chamber C, and bubbles and notches may be generated in the outer peripheral portion of the obtained plastic lens. On the other hand, when the thickness of the adhesive layer 3 is thicker than 50 μm, the thickness of the adhesive tape 1 becomes too thick, and gaps are likely to be generated in the overlapping portion of the adhesive tapes, and the resin 100 may leak from the chamber C.

[0096] (Adhesive tape)

[0097] When the pressure-sensitive adhesive tape 1 of the present embodiment is immersed in toluene adjusted to a temperature of 80 °C for 2 hours, the dissolution rate of the pressure-sensitive adhesive layer 3 is 48.0% or less, preferably 38.0% or less. If the above dissolution rate exceeds 48.0%, in the case of using a short-time temperature-rising curing process with a high curing start temperature and a short temperature-rising time in the manufacturing process of the plastic lens described later, that is, when the pressure-sensitive adhesive layer is exposed to a viscous and high-temperature polymerizable monomer or prepolymer for the plastic lens for more than several hours before it is fully cured in the initial stage of polymerization, the risk of a part of the pressure-sensitive adhesive composition dissolving from the pressure-sensitive adhesive layer into the monomer or prepolymer as the raw material of the plastic lens is sharply increased compared with the conventional temperature-rising curing process that slowly rises in temperature from normal temperature to high temperature over a long time. Due to the influence of the dissolved matter, whitening occurs at the outer peripheral part of the obtained plastic lens. If the above dissolution rate is 48.0% or less, the influence of its dissolved matter can be suppressed to an acceptable level, so whitening at a problematic level in terms of quality will not occur at the outer peripheral part of the obtained plastic lens.

[0098] In addition, the deviation amount of the pressure-sensitive adhesive tape 1 of the present embodiment after 800 minutes in the creep test (temperature 40 °C, load 0.5 kg) is 0.15 mm or more and 0.50 mm or less. If the above deviation amount is within this range, in the manufacturing process of the plastic lens described later, even if the polymerizable monomer and / or prepolymer cures and shrinks, the phenomenon of wrinkles generated at the outer peripheral part of the obtained plastic lens can be suppressed. In addition, the generation of adhesive residue on the side of the mold 50 and the plastic lens molded product when the pressure-sensitive adhesive tape 1 is peeled off from the mold 50 after polymerization and curing can also be suppressed. The above deviation amount is preferably in the range of 0.20 mm to 0.50 mm.

[0099] <Thickness of the pressure-sensitive adhesive tape>

[0100] As the overall thickness of the pressure-sensitive adhesive tape 1 having the configuration described above, it is preferably in the range of 37 μm or more and 110 μm or less. When the thickness of the pressure-sensitive adhesive tape 1 is less than 37 μm, since the thickness of the pressure-sensitive adhesive layer 3 becomes thinner, the fixing force to the mold 50 and the adhesive force of the overlapping part of the pressure-sensitive adhesive tapes 1 are reduced, and the resin 100 leaks out from the lens chamber C, and bubbles and notches may occur at the outer peripheral part of the obtained plastic lens. On the other hand, when the thickness of the pressure-sensitive adhesive tape 1 exceeds 110 μm, the thickness of the pressure-sensitive adhesive tape 1 becomes too thick, and gaps are likely to occur at the overlapping part of the pressure-sensitive adhesive tapes, and the resin 100 may leak out from the chamber C.

[0101] (Manufacturing method of the pressure-sensitive adhesive tape)

[0102] Next, an example of application is listed Figure 1Taking the adhesive tape 1 of the first embodiment described in [reference] as an example, its manufacturing method will be described. The adhesive tape 1 is formed by forming a composite substrate 2 and laminating an adhesive layer 3 on the formed composite substrate 2.

[0103] [Formation of Composite Substrate]

[0104] First, an adhesive composed of, for example, a polyester-based polyurethane adhesive, an epoxy resin adhesive, etc. is coated on a polyethylene terephthalate (PET) film serving as the second substrate 7 using a gravure roll or the like and dried. Thus, a second laminate 20 in which an adhesive layer 6 is laminated on the second substrate 7 is formed. Next, a first laminate 10 in which an inorganic thin film layer 5 composed of silica or the like is laminated on a polyethylene terephthalate (PET) film serving as the first substrate 4 is bonded to the formed second laminate 20 such that the inorganic thin film layer 5 faces the adhesive layer 6. Thus, a composite substrate 2 formed by laminating the first laminate 10 and the second laminate 20 is formed. Then, the composite substrate 2 is wound such that the first laminate 10 side (the first substrate 4 side) becomes the inner side, and the wound composite substrate 2 is cured in an atmosphere of 40°C to 50°C for 48 hours.

[0105] In addition, in the formation process of the composite substrate 2, for example, when the adhesive layer 6 is formed by directly coating an adhesive on the inorganic thin film layer 5 laminated on the first substrate 4 and the second substrate 7 is laminated on the adhesive layer 6 to form the composite substrate 2, the inorganic thin film layer 5 may be damaged such as cracked or fractured. Specifically, when coating the adhesive on the inorganic thin film layer 5, when further laminating the second substrate 7 on the adhesive layer 6 formed on the inorganic thin film layer 5, etc., a load may be applied to the inorganic thin film layer 5, resulting in cracking or fracturing of the inorganic thin film layer 5. And in the adhesive tape 1 including such an inorganic thin film layer 5, moisture easily permeates when the inorganic thin film layer 5 is damaged, etc., and there is a concern that the water vapor transmission rate increases.

[0106] In contrast, in the present embodiment, instead of directly laminating the adhesive layer 6 on the inorganic thin film layer 5, the adhesive layer 6 is laminated on the second substrate 7 to form the second laminate 20, and then the first laminate 10 and the second laminate 20 are bonded to form the composite substrate 2. By forming the composite substrate 2 using such a process, in the present embodiment, compared with the case of directly forming the adhesive layer 6 on the inorganic thin film layer 5 as described above, the load applied to the inorganic thin film layer 5 can be suppressed. As a result, the generation of cracking and fracturing of the inorganic thin film layer 5 can be suppressed, and the increase in the water vapor transmission rate of the adhesive tape 1 can be suppressed.

[0107] [Formation of Adhesive Layer]

[0108] Next, for the cured composite substrate 2, an adhesive composed of an acrylic copolymer resin or the like is applied to the first substrate 4 of the first laminate 10 to form an adhesive layer 3. Specifically, a crosslinking agent is added to a solution obtained by dissolving an adhesive mainly composed of an acrylic copolymer in an organic solvent such as ethyl acetate, toluene, or xylene to prepare an adhesive composition. Then, the adhesive composition is applied to the first substrate 4 in the composite substrate 2 using a beveled wheel coater, a lip coater, or the like so that the thickness after drying becomes uniform. Then, the applied adhesive composition is dried at a predetermined temperature to form an adhesive layer 3 on the composite substrate 2. The adhesive tape 1 (first embodiment) shown in Figure 1 is obtained through the above steps.

[0109] Generally, when manufacturing an adhesive tape by forming an adhesive layer on a substrate using a beveled wheel coater, a lip coater, or the like, the adhesive composition is applied while applying tension to the substrate. Here, when forming a film having an inorganic substance such as the inorganic thin film layer 5 of the present embodiment on the substrate, when forming an adhesive layer on the substrate, by applying tension to the substrate or bringing the film into contact with a guide roller, there is a case where a load is applied to the film and the film is broken. And, when the film is broken or the like, moisture easily permeates through the break of the film, etc., so that the water vapor transmission rate of the adhesive tape increases.

[0110] In contrast, the composite substrate 2 of the adhesive tape 1 of the present embodiment has a configuration in which the inorganic thin film layer 5 is sandwiched between the first substrate 4 and the second substrate 7 with the adhesive layer 6 interposed therebetween. Thus, when forming the adhesive layer 3 on the composite substrate 2, even when tension is applied to the composite substrate 2, compared with the case of not having this configuration, the inorganic thin film layer 5 can be protected by the first substrate 4 and the second substrate 7, and the occurrence of breakage or the like of the inorganic thin film layer 5 can be suppressed. And, by suppressing the occurrence of breakage or the like of the inorganic thin film layer 5, an increase in the water vapor transmission rate of the adhesive tape 1 can be suppressed.

[0111] It should be noted that the adhesive tape 1 formed through the above steps is usually wound so that the adhesive layer 3 is on the inside. In the present embodiment, since the adhesive layer 3 is provided on the first substrate 4, in the state where the adhesive tape 1 is wound, the composite substrate 2 is wound with the first substrate 4 side on the inside. In addition, in the formation process of the composite substrate 2, when the first laminate 10 is cured, the first laminate 10 is wound with the first substrate 4 side on the inside.

[0112] That is, in the present embodiment, in the state where the manufactured adhesive tape 1 is wound and in the state where the first laminate 10 is wound in the forming process of the composite substrate 2, the winding directions of the first laminate 10 are the same, and the winding direction of the inorganic thin film layer 5 provided on the first laminate 10 in the manufacturing process of the adhesive tape 1 does not change. Here, for example, if the winding direction of the inorganic thin film layer 5 changes in the manufacturing process of the adhesive tape 1, there is a concern that a load is applied to the inorganic thin film layer 5, resulting in cracks, defects, and fractures. In contrast, in the present embodiment, by adopting a configuration in which the winding direction of the inorganic thin film layer 5 does not change in the manufacturing process of the adhesive tape 1, it is possible to suppress the load on the inorganic thin film layer 5 and suppress the occurrence of fractures and the like in the inorganic thin film layer 5.

[0113] (Molding method of plastic lens using adhesive tape)

[0114] As described above, the adhesive tape 1 of the present embodiment is used, for example, in the molding of plastic lenses that can be used as spectacle lenses and the like. Next, an example of a molding method of a plastic lens using the adhesive tape 1 of the present embodiment will be described.

[0115] Figure 2 It is a perspective view showing an example of the structure of a glass mold used in the molding method of the plastic lens of the present invention.

[0116] [Chamber forming process]

[0117] First, as Figure 2 shown, after a pair of molds 50 having a substantially disk-shaped shape are disposed opposite to each other with a predetermined interval therebetween, the adhesive tape 1 is pasted along the circumferential direction on the outer peripheral portions of the two molds 50. Then, while maintaining the interval between the molds 50, the opening of the space formed between the molds 50 is continuously sealed. As a result, as Figure 2 shown, the molds 50 are connected to each other substantially in parallel, and at the same time, a lens-shaped chamber C is partitioned and formed therebetween. It should be noted that as the mold 50, a glass (silica) mold or a metal mold is usually mostly used, but the material of the mold 50 is not limited to these.

[0118] [Resin filling process]

[0119] After the chamber C is formed between the molds 50, next, as Figure 2 shown, one end of the adhesive tape 1 is peeled off to open a gap, and a nozzle (not shown) is inserted into the chamber C from this gap. Then, a liquid resin 100 is injected and filled into the chamber C from this nozzle. Then, the peeled adhesive tape 1 is restored to its original state to block the gap. It should be noted that the resin 100 injected and filled into the chamber C is, for example, a resin in which a polymerization initiator and a crosslinking agent are added to a polymerizable monomer and / or a polymerizable prepolymer.

[0120] [Polymerization process]

[0121] Next, the molds 50 wound with the adhesive tape 1 and filled with the resin 100 into the chamber C are arranged in the polymerization furnace, and the resin 100 in the chamber C is polymerized and cured by heating, light irradiation, or the like. Then, after the resin 100 is sufficiently cured, the adhesive tape 1 is completely peeled off and the mold 50 is disassembled to obtain a plastic lens. Here, as a short-time temperature-rising process in the polymerization process by heating, the polymerization start temperature is 45°C or higher and 65°C or lower, and the heating rate to reach the final curing temperature of 130°C or higher and 150°C or lower is preferably 0.10°C / minute or higher and 0.45°C / minute or lower. If the polymerization start temperature, the final curing temperature, and the heating rate are within the above ranges, even in the short-time temperature-rising process, the quality of the obtained high-refractive-index plastic lens can be maintained at an acceptable level.

[0122] It should be noted that the plastic lens formed in this embodiment is used as, for example, a spectacle lens. Here, as the resin 100 (polymerizable monomer or polymerizable prepolymer) used in the molding of the plastic lens, conventionally known materials can be used. For example, in the case of forming a spectacle lens with an ultra-high refractive index (refractive index: 1.65 or higher), monomers, prepolymers, etc. of episulfide resins (MR-174 (trade name) manufactured by Mitsui Chemicals, Inc., IU-20 (trade name) manufactured by Mitsubishi Gas Chemical Company, Inc.), and thiourethane resins (MR-7 (trade name) manufactured by Mitsui Chemicals, Inc.) are used.

[0123] In addition, in the case of forming a spectacle lens with a high refractive index (refractive index: 1.59 or higher and less than 1.65), monomers, prepolymers, etc. of thiourethane resins (MR-6 (trade name), MR-8 (trade name) manufactured by Mitsui Chemicals, Inc.), polyester methacrylate (TS-26 (trade name) manufactured by Tokuyama Corporation), and polycarbonate (Panlite (trade name) manufactured by Teijin Chemicals Ltd.) are used.

[0124] Conventionally, in the polymerization process of the manufacturing process of plastic lenses, moisture in the external air sometimes penetrates through the adhesive tape 1 and enters the chamber C. And when the moisture mixes into the resin 100, it sometimes reacts with, for example, a crosslinking agent added to the resin 100 to generate gas or the like. As a result, voids are formed in the plastic lens, and sometimes the obtained plastic lens has bubbles or whitening. Here, when the voids in the formed plastic lens are large due to the mixing of moisture in the external air into the resin 100, bubbles are generated in the main peripheral part of the plastic lens, and when the voids are small, whitening is generated in the main central part of the plastic lens.

[0125] Particularly, when using an isocyanate-based curing agent in the curing of a resin 100 such as a thiourethane-based resin, the isocyanate groups (NCO groups) in the resin 100 react with the moisture mixed into the resin 100 to generate CO2 gas as a by-product. Moreover, voids are formed by this CO2 gas, and thus bubbles and whitening sometimes occur in the plastic lens.

[0126] In contrast, in the adhesive tape 1 of the present embodiment, an inorganic thin film layer 5 for suppressing the permeation of moisture in the adhesive tape 1 is provided. Moreover, the adhesive tape 1 has a configuration in which the inorganic thin film layer 5 is sandwiched between a first base material 4 and a second base material 7 with a bonding layer 6 interposed therebetween. By having such a configuration, in the adhesive tape 1 of the present embodiment, the inorganic thin film layer 5 is protected by the first base material 4 and the second base material 7, and the inorganic thin film layer 5 is less likely to be damaged or the like in the manufacturing process of the adhesive tape 1 and the manufacturing process of the plastic lens.

[0127] Accordingly, in the present embodiment, in the manufacturing process of the plastic lens, it is possible to suppress the permeation of moisture in the external air through the adhesive tape 1 and the intrusion into the chamber C due to the breakage or the like of the inorganic thin film layer 5.

[0128] As a result, in the formed plastic lens, it is possible to suppress the generation of bubbles and whitening caused by the mixing of moisture into the resin 100 in the chamber C.

[0129] Examples

[0130] Next, the present invention will be described in more detail using examples and comparative examples. It should be noted that the present invention is not limited to the following examples.

[0131] Hereinafter, each example and each comparative example will be described in detail.

[0132] 1. Production of the adhesive tape 1 and molding of the plastic lens

[0133] (Example 1)

[0134] A first laminate 10 (TECHBARRIER LX (trade name), manufactured by Mitsubishi Rayon Co., Ltd.) in which silica was vapor-deposited on a 12-μm-thick polyester film as the first base material 4 and the inorganic thin film layer 5 was laminated, and a second laminate 20 in which a 1-μm-thick polyester-based adhesive (TAKELAC A-310 / TAKENATE A-3 (trade name), manufactured by Mitsui Chemicals, Inc.) as the bonding layer 6 was laminated on a 25-μm-thick polyester film (polyester film manufactured by Mitsubishi Rayon Co., Ltd.) as the second base material 7 were bonded together with the inorganic thin film layer 5 facing the bonding layer 6 to form a composite base material 2.

[0135] The ethyl acetate / toluene solution (solid content concentration: 40 mass%) of the adhesive composed of acrylic copolymer A1 (dodecyl methacrylate / acrylic acid / vinyl acetate = 78 mass% / 2 mass% / 20 mass%, acid value: 14.8 mgKOH / g) was adjusted. The polystyrene-reduced weight-average molecular weight (Mw) of acrylic copolymer A1 measured by gel permeation chromatography was 1,320,000, and the polydispersity (Mw / Mn) was 9.3. In addition, the glass transition temperature Tg calculated by the Fox equation was -49°C.

[0136] Next, with respect to 250 parts by mass (100 parts by mass in terms of solid content) of the adhesive solution, 6.8 parts by mass (3.0 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.49) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration: 45 mass%, NCO content: 8 mass%) manufactured by Soken Chemical & Engineering Co., Ltd. was blended using a disperser to prepare an adhesive solution for coating (solid content concentration: 40 mass%).

[0137] Next, the adhesive solution for coating was applied onto the first substrate 4 of the composite substrate 2 and then heated at 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained.

[0138] Next, using the formed adhesive tape 1, through Figure 2The method shown forms two thiourethane-based plastic lenses PL1 and PL2 with different refractive indices. As the main raw materials of the resin for forming the plastic lens PL1, a mixture of 56.48 parts by mass of pentaerythritol tetrakis(mercapto propionate) and 43.52 parts by mass of m-xylene diisocyanate is used. As additives, 0.007 parts by mass of a tin-based catalyst, 0.14 parts by mass of an acidic phosphate-based internal mold release agent, and 0.10 parts by mass of a benzotriazole-based ultraviolet absorber are used. After stirring and mixing m-xylene diisocyanate and the additives under reduced pressure, pentaerythritol tetrakis(mercapto propionate) is added, and the mixture is slowly stirred and mixed under reduced pressure at 60 °C. The stirring and mixing are terminated when the viscosity reaches 200 cps (23 °C), and a resin composition for forming the plastic lens PL1 is prepared. As the main raw materials of the resin for forming the plastic lens PL2, a mixture of 48.09 parts by mass of 2,3-bis(2-mercaptoethylthio)propane-1-thiol and 51.91 parts by mass of m-xylene diisocyanate is used. As additives, 0.007 parts by mass of a tin-based catalyst, 0.14 parts by mass of an acidic phosphate-based internal mold release agent, and 0.10 parts by mass of a benzotriazole-based ultraviolet absorber are used. After stirring and mixing m-xylene diisocyanate and the additives under reduced pressure, 2,3-bis(2-mercaptoethylthio)propane-1-thiol is added, and the mixture is slowly stirred and mixed under reduced pressure at 60 °C. The stirring and mixing are terminated when the viscosity reaches 200 cps (23 °C), and a resin composition for forming the plastic lens PL2 is prepared. The polymerization start temperature is set at 60 °C, and it is raised to the polymerization final temperature of 130 °C in 10 hours (heating rate: 0.12 °C / min). After the sample is held at 130 °C for 5 hours, it is cooled to 60 °C in 2 hours, and a thiourethane-based plastic lens PL1 (refractive index 1.60) and a thiourethane-based plastic lens PL2 (refractive index 1.67) are obtained.

[0139] (Example 2)

[0140] An ethyl acetate / toluene solution (solid content concentration 40 mass%) of an adhesive composed of an acrylic copolymer A2 (dodecyl methacrylate / acrylic acid / vinyl acetate = 78 mass% / 2 mass% / 20 mass%, acid value 14.9 mgKOH / g) is prepared. The polystyrene-reduced weight average molecular weight (Mw) of the acrylic copolymer A2 measured by gel permeation chromatography is 1,100,000, and the polydispersity (Mw / Mn) is 9.8. In addition, the glass transition temperature Tg calculated by the Fox equation is -49 °C.

[0141] Next, 6.8 parts by mass (3.0 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.49) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration 45 mass%, NCO content 8 mass%) manufactured by Soken Chemical & Engineering Co., Ltd. was blended with respect to 250 parts by mass of this adhesive solution (100 parts by mass in terms of solid content), and an adhesive solution for coating (solid content concentration 40 mass%) was prepared.

[0142] Next, after coating this adhesive solution for coating on the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes, thereby forming an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0143] (Example 3)

[0144] An ethyl acetate / toluene solution (solid content concentration 40 mass%) of an adhesive composed of acrylic copolymer A3 (dodecyl methacrylate / acrylic acid / vinyl acetate = 78 mass% / 2 mass% / 20 mass%, acid value 14.5 mgKOH / g) was prepared. The polystyrene-reduced weight average molecular weight (Mw) of acrylic copolymer A3 measured by gel permeation chromatography was 1,380,000, and the polydispersity (Mw / Mn) was 9.5. In addition, the glass transition temperature Tg calculated by the Fox equation was -49°C.

[0145] Next, 6.8 parts by mass (3.0 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.50) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration 45 mass%, NCO content 8 mass%) manufactured by Soken Chemical & Engineering Co., Ltd. was blended with respect to 250 parts by mass of this adhesive solution (100 parts by mass in terms of solid content), and an adhesive solution for coating (solid content concentration 40 mass%) was prepared.

[0146] Next, after coating this adhesive solution for coating on the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes, thereby forming an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0147] (Example 4)

[0148] The amount of the polyisocyanate-based crosslinking agent "CORONATE L-45" (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was changed to 5.0 parts by mass (2.3 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.36). Except for this, the same operations as in Example 1 were carried out to obtain Adhesive Tape 1 and a plastic lens.

[0149] (Example 5)

[0150] The amount of the polyisocyanate-based crosslinking agent "CORONATE L-45" (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was changed to 8.3 parts by mass (3.7 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.60). Except for this, the same operations as in Example 1 were carried out to obtain Adhesive Tape 1 and a plastic lens.

[0151] (Example 6)

[0152] The amount of the polyisocyanate-based crosslinking agent "CORONATE L-45" (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was changed to 3.2 parts by mass (1.4 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.23). Except for this, the same operations as in Example 1 were carried out to obtain Adhesive Tape 1 and a plastic lens.

[0153] (Example 7)

[0154] The amount of the polyisocyanate-based crosslinking agent "CORONATE L-45" (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was changed to 10.0 parts by mass (4.5 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.72). Except for this, the same operations as in Example 1 were carried out to obtain Adhesive Tape 1 and a plastic lens.

[0155] (Example 8)

[0156] An ethyl acetate / toluene solution (solid content concentration: 40% by mass) of an adhesive composed of an acrylic copolymer B (dodecyl methacrylate / acrylic acid / vinyl acetate = 79% by mass / 1% by mass / 20% by mass, acid value: 7.5 mgKOH / g) was prepared. The polystyrene-reduced weight-average molecular weight (Mw) of the acrylic copolymer B measured by gel permeation chromatography was 1,350,000, and the polydispersity (Mw / Mn) was 9.2. In addition, the glass transition temperature Tg calculated by the Fox equation was -50°C.

[0157] Next, 5.3 parts by mass (2.4 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.75) of the polyisocyanate-based crosslinking agent "CORONATE L-45" (trade name, solid content concentration 45 mass%, NCO content 8 mass%) manufactured by Soken Chemical & Engineering Co., Ltd. was blended with respect to 250 parts by mass of the adhesive solution (100 parts by mass in terms of solid content), and an adhesive solution for coating (solid content concentration 40 mass%) was prepared.

[0158] Next, after coating the first substrate 4 of the composite substrate 2 with the adhesive solution for coating, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, a plastic lens was obtained in the same manner as in Example 1.

[0159] (Example 9)

[0160] An ethyl acetate / toluene solution (solid content concentration 40 mass%) of an adhesive composed of an acrylic copolymer C (dodecyl methacrylate / acrylic acid / vinyl acetate = 75 mass% / 5 mass% / 20 mass%, acid value 37.1 mgKOH / g) was prepared. The polystyrene-reduced weight average molecular weight (Mw) of the acrylic copolymer C measured by gel permeation chromatography was 1,150,000 and the polydispersity (Mw / Mn) was 9.7. In addition, the glass transition temperature Tg calculated by the Fox equation was -45°C.

[0161] Next, 10.1 parts by mass (4.5 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.29) of the polyisocyanate-based crosslinking agent "CORONATE L-45" (trade name, solid content concentration 45 mass%, NCO content 8 mass%) manufactured by Soken Chemical & Engineering Co., Ltd. was blended with respect to 250 parts by mass of the adhesive solution (100 parts by mass in terms of solid content), and an adhesive solution for coating (solid content concentration 40 mass%) was prepared.

[0162] Next, after coating the first substrate 4 of the composite substrate 2 with the adhesive solution for coating, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, a plastic lens was obtained in the same manner as in Example 1.

[0163] (Example 10)

[0164] An ethyl acetate / toluene solution (solid content concentration: 40% by mass) of an adhesive composed of an acrylic copolymer D (dodecyl acrylate / 2-ethylhexyl acrylate / acrylic acid = 78% by mass / 20% by mass / 2% by mass, acid value: 14.9 mg KOH / g) was prepared. The polystyrene-reduced weight-average molecular weight (Mw) of the acrylic polymer D determined by gel permeation chromatography was 1,200,000, and the polydispersity (Mw / Mn) was 9.7. Additionally, the glass transition temperature Tg calculated by the Fox equation was -22°C.

[0165] Next, with respect to 250 parts by mass (100 parts by mass in terms of solid content) of this adhesive solution, 6.8 parts by mass (3.0 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.49) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was blended using a disperser to prepare a coating adhesive solution (solid content concentration: 40% by mass).

[0166] Next, after coating this coating adhesive solution onto the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thereby, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0167] (Example 11)

[0168] An ethyl acetate / toluene solution (solid content concentration: 40% by mass) of an adhesive composed of an acrylic copolymer E (isodecyl methacrylate / acrylic acid / vinyl acetate = 78% by mass / 2% by mass / 20% by mass, acid value: 14.6 mg KOH / g) was prepared. The polystyrene-reduced weight-average molecular weight (Mw) of the acrylic copolymer E determined by gel permeation chromatography was 1,360,000, and the polydispersity (Mw / Mn) was 9.2. Additionally, the glass transition temperature Tg calculated by the Fox equation was -27°C.

[0169] Next, with respect to 250 parts by mass (100 parts by mass in terms of solid content) of this adhesive solution, 6.8 parts by mass (3.0 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.50) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was blended using a disperser to prepare a coating adhesive solution (solid content concentration: 40% by mass).

[0170] Next, after applying the adhesive solution for coating onto the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0171] (Example 12)

[0172] An ethyl acetate / toluene solution (solid content concentration: 40% by mass) of an adhesive composed of an acrylic copolymer F (tetradecyl methacrylate / 2-ethylhexyl acrylate / acrylic acid = 88% by mass / 10% by mass / 2% by mass, acid value: 14.9 mgKOH / g) was prepared. The polystyrene-reduced weight average molecular weight (Mw) of the acrylic copolymer F measured by gel permeation chromatography was 1,100,000, and the polydispersity (Mw / Mn) was 10.0. In addition, the glass transition temperature Tg calculated by the Fox equation was -20°C.

[0173] Next, 5.0 parts by mass (2.3 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.36) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was added to 250 parts by mass (100 parts by mass in terms of solid content) of the adhesive solution using a disperser to prepare an adhesive solution for coating (solid content concentration: 40% by mass).

[0174] Next, after applying the adhesive solution for coating onto the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0175] (Example 13)

[0176] An ethyl acetate / toluene solution (solid content concentration: 40% by mass) of an adhesive composed of an acrylic copolymer G (2-ethylhexyl acrylate / acrylic acid / vinyl acetate = 83% by mass / 2% by mass / 15% by mass, acid value: 15.0 mgKOH / g) was prepared. The polystyrene-reduced weight average molecular weight (Mw) of the acrylic copolymer G measured by gel permeation chromatography was 1,380,000, and the polydispersity (Mw / Mn) was 10.0. In addition, the glass transition temperature Tg calculated by the Fox equation was -57°C.

[0177] Next, 8.3 parts by mass (3.7 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.59) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration 45 mass%, NCO content 8 mass%) manufactured by Synthetic Chemical Industry Co., Ltd. was blended with respect to 250 parts by mass of the adhesive solution (100 parts by mass in terms of solid content), and an adhesive solution for coating (solid content concentration 40 mass%) was prepared.

[0178] Next, after coating the adhesive solution for coating on the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0179] (Example 14)

[0180] An ethyl acetate / toluene solution (solid content concentration 40 mass%) of an adhesive composed of an acrylic copolymer H (dodecyl methacrylate / 2-hydroxyethyl acrylate / vinyl acetate = 83 mass% / 2 mass% / 15 mass%, hydroxyl value 10.0 mgKOH / g) was prepared. The polystyrene-reduced weight average molecular weight (Mw) of the acrylic copolymer H measured by gel permeation chromatography was 1,420,000, and the polydispersity (Mw / Mn) was 9.8. In addition, the glass transition temperature Tg calculated by the Fox equation was -54°C.

[0181] Next, 5.0 parts by mass (2.3 parts by mass in terms of solid content, NCO / OH equivalent ratio = 0.53) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration 45 mass%, NCO content 8 mass%) manufactured by Synthetic Chemical Industry Co., Ltd. was blended with respect to 250 parts by mass of the adhesive solution (100 parts by mass in terms of solid content), and an adhesive solution for coating (solid content concentration 40 mass%) was prepared.

[0182] Next, after coating the adhesive solution for coating on the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0183] (Comparative Example 1)

[0184] The ethyl acetate solution (solid content concentration: 30% by mass) of an adhesive composed of acrylic copolymer I (n-butyl acrylate / methyl acrylate / 2-hydroxyethyl acrylate = 85% by mass / 10% by mass / 5% by mass, hydroxyl value: 24.0 mg KOH / g) was adjusted. The polystyrene-reduced weight-average molecular weight (Mw) of acrylic copolymer I measured by gel permeation chromatography was 753,000, and the polydispersity (Mw / Mn) was 17.1. In addition, the glass transition temperature Tg calculated by the Fox equation was -48°C.

[0185] Next, 6.7 parts by mass (3.0 parts by mass in terms of solid content, NCO / OH equivalent ratio = 0.30) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was added to 333 parts by mass (100 parts by mass in terms of solid content) of the adhesive solution using a disperser to prepare an adhesive solution for coating (solid content concentration: 30% by mass).

[0186] Next, the adhesive solution for coating was applied to the first substrate 4 of the composite substrate 2 and then heated at 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, a plastic lens was obtained in the same manner as in Example 1.

[0187] (Comparative Example 2)

[0188] The ethyl acetate solution (solid content concentration: 30% by mass) of an adhesive composed of acrylic copolymer I (n-butyl acrylate / methyl acrylate / 2-hydroxyethyl acrylate = 85% by mass / 10% by mass / 5% by mass, hydroxyl value: 24.0 mg KOH / g) was adjusted. The polystyrene-reduced weight-average molecular weight (Mw) of acrylic copolymer I measured by gel permeation chromatography was 753,000, and the polydispersity (Mw / Mn) was 17.1. In addition, the glass transition temperature Tg calculated by the Fox equation was -48°C.

[0189] Next, 11.2 parts by mass (5.0 parts by mass in terms of solid content, NCO / OH equivalent ratio = 0.50) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was added to 333 parts by mass (100 parts by mass in terms of solid content) of the adhesive solution using a disperser to prepare an adhesive solution for coating (solid content concentration: 30% by mass).

[0190] Next, after applying the adhesive solution for coating onto the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0191] (Comparative Example 3)

[0192] An ethyl acetate / toluene solution (solid content concentration: 30% by mass) of an adhesive composed of an acrylic copolymer J (2-ethylhexyl acrylate / acrylic acid / vinyl acetate = 89.5% by mass / 0.5% by mass / 10% by mass, acid value: 3.8 mg KOH / g) was prepared. The polystyrene-reduced weight-average molecular weight (Mw) of the acrylic copolymer J measured by gel permeation chromatography was 1,020,000, and the polydispersity (Mw / Mn) was 31.2. In addition, the glass transition temperature Tg calculated by the Fox equation was -63°C.

[0193] Next, 3.3 parts by mass (1.5 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 1.07) of the polyisocyanate-based crosslinking agent “CORONATE L-45” (trade name, solid content concentration: 45% by mass, NCO content: 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was added to 333 parts by mass (100 parts by mass in terms of solid content) of the adhesive solution using a disperser to prepare an adhesive solution for coating (solid content concentration: 30% by mass).

[0194] Next, after applying the adhesive solution for coating onto the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0195] (Comparative Example 4)

[0196] An ethyl acetate / toluene solution (solid content concentration: 30% by mass) of an adhesive composed of an acrylic copolymer K (n-butyl acrylate / methyl acrylate / 2-hydroxyethyl acrylate = 50% by mass / 45% by mass / 5% by mass) was prepared. The polystyrene-reduced weight-average molecular weight (Mw) of the acrylic copolymer K measured by gel permeation chromatography was 672,000, and the polydispersity (Mw / Mn) was 18.2. In addition, the glass transition temperature Tg calculated by the Fox equation was -28°C.

[0197] Next, 3.3 parts by mass (1.5 parts by mass in terms of solid content, NCO / OH equivalent ratio = 0.15) of the polyisocyanate-based crosslinking agent "CORONATE L-45" (trade name, solid content concentration 45 mass%, NCO content 8 mass%) manufactured by Soken Chemical & Engineering Co., Ltd. was blended with respect to 333 parts by mass of the adhesive solution (100 parts by mass in terms of solid content), and an adhesive solution for coating (solid content concentration 30 mass%) was prepared.

[0198] Next, after coating the adhesive solution for coating on the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained. Next, in the same manner as in Example 1, a plastic lens was obtained.

[0199] (Comparative Example 5)

[0200] An ethyl acetate / toluene solution (solid content concentration 40 mass%) of an adhesive composed of acrylic copolymer A4 (dodecyl methacrylate / acrylic acid / vinyl acetate = 78 mass% / 2 mass% / 20 mass%, acid value 14.8 mgKOH / g) was prepared. The polystyrene-converted weight-average molecular weight (Mw) of acrylic copolymer A4 measured by gel permeation chromatography was 1,240,000, and the polydispersity (Mw / Mn) was 16.7. In addition, the glass transition temperature Tg calculated by the Fox equation was -49°C.

[0201] Next, 3.2 parts by mass (1.4 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.23) of the polyisocyanate-based crosslinking agent "CORONATE L-45" (trade name, solid content concentration 45 mass%, NCO content 8 mass%) manufactured by Soken Chemical & Engineering Co., Ltd. was blended with respect to 250 parts by mass of the adhesive solution (100 parts by mass in terms of solid content), and an adhesive solution for coating (solid content concentration 40 mass%) was prepared.

[0202] Next, after coating the adhesive solution for coating on the first substrate 4 of the composite substrate 2, it was heated at a temperature of 110°C for 3 minutes to form an adhesive layer 3 with a dried thickness of 30 μm. Thus, an adhesive tape 1 with a total dried thickness of 68 μm was obtained.

[0203] (Comparative Example 6)

[0204] The amount of the polyisocyanate crosslinking agent "CORONATE L-45" (trade name, solid content concentration 45% by mass, NCO content 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was changed to 11.7 parts by mass (5.3 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.84). Except for this, the same operations as in Example 1 were carried out to obtain Adhesive Tape 1 and a plastic lens.

[0205] (Comparative Example 7)

[0206] The amount of the polyisocyanate crosslinking agent "CORONATE L-45" (trade name, solid content concentration 45% by mass, NCO content 8% by mass) manufactured by Soken Chemical & Engineering Co., Ltd. was changed to 2.6 parts by mass (1.2 parts by mass in terms of solid content, NCO / COOH equivalent ratio = 0.19). Except for this, the same operations as in Example 1 were carried out to obtain Adhesive Tape 1 and a plastic lens.

[0207] 2. Evaluation method

[0208] (1) Evaluation method for Adhesive Tape 1

[0209] (1-1) Adhesion test

[0210] Under the temperature condition of 23°C, for the Adhesive Tape 1 prepared in Examples 1 to 14 and Comparative Examples 1 to 7, according to the method described in JIS Z 0237 (2009), a relative grinding SUS adhesion test (peel adhesion test) was carried out.

[0211] Specifically, the Adhesive Tape 1 was adhered to a ground stainless steel plate (SUS304), and a roller with a mass of 2 kg was reciprocally pressed once at a speed of 5 mm / second. Then, after standing for 20 to 40 minutes, a tensile testing machine was used to peel in the 180° direction relative to the stainless steel plate at a speed of 5 mm / second, and the adhesion to the relative grinding SUS plate was measured.

[0212] (1-2) Holding force test

[0213] Under the temperature condition of 23°C, for the adhesive tapes 1 prepared in Examples 1 to 14 and Comparative Examples 1 to 7, the relative abrasion SUS adhesion test (holding force test) was carried out according to the method described in JIS Z 0237 (2009). Specifically, the adhesive layer was adhered to a relative abrasion SUS plate (SUS304) with an area of 25 mm × 25 mm in such a way that the end portion in the length direction of the adhesive tape 1 protruded. Then, a roller with a mass of 2 kg was reciprocally pressed on the adhesive tape 1 at a speed of 5 mm / second once. Next, after about 20 minutes to 40 minutes from the pressing of the adhesive tape 1, a weight of 1 kg was installed at the end portion of the adhesive tape 1 under the temperature condition of 40°C. Then, the elapsed time from the installation of the weight until the adhesive tape 1 was completely peeled off from the abrasion SUS plate, or the deviation amount (mm) of the adhesive tape 1 after 24 hours was measured.

[0214] (1-3) Creep test

[0215] Under the temperature condition of 23°C, for the adhesive tapes 1 prepared in Examples 1 to 14 and Comparative Examples 1 to 7, the adhesive layer was adhered to a relative abrasion SUS plate (SUS304) with an area of 25 mm × 25 mm in such a way that the end portion in the length direction of the adhesive tape 1 protruded. Then, a roller with a mass of 2 kg was reciprocally pressed on the adhesive tape 1 at a speed of 5 mm / second once. Next, after about 20 minutes to 40 minutes from the pressing of the adhesive tape 1, the test piece was placed in a 6-channel recording creep testing machine (Toyo Seiki Seisaku-sho, Ltd., model C100-6) adjusted to 40°C, and a load of 0.5 kg was applied. Then, the deviation amount (mm) after 800 minutes was measured to conduct the creep test. It should be noted that the deviation amount was set as the average value of 6 test pieces.

[0216] (1-4) Measurement of the dissolution rate of the adhesive layer

[0217] For the adhesive tapes 1 prepared in Examples 1 to 14 and Comparative Examples 1 to 7, test pieces were cut with an area of 25 mm × 25 mm. Then, they were immersed in toluene adjusted to 20°C and 80°C for 2 hours, and the weights before and after immersion were measured. The dissolution rate with respect to toluene at each temperature was measured by the following formula (1).

[0218] Dissolution rate (%) = {1 - [(W2 - W0) / (W1 - W0)]} × 100 (1)

[0219] (W0: weight of the base material, W1: weight of the test piece before immersion, W2: weight of the test piece after immersion and drying)

[0220] (2) Evaluation of plastic lenses

[0221] For the plastic lenses PL1 and PL2 produced using the adhesive tapes 1 prepared in Examples 1 to 14 and Comparative Examples 1 to 7, the presence or absence of whitening, wrinkles, and bubbles was visually observed and evaluated. In addition, the presence or absence of adhesive residue on the mold and the side surfaces of the plastic lenses after peeling off the adhesive tape 1 was also visually evaluated. It should be noted that the whitening of the plastic lens refers to the state in which the plastic lens shows white turbidity when irradiated with light. The evaluation of the occurrence of whitening, wrinkles, and bubbles in the plastic lens, as well as the occurrence of adhesive residue on the mold and the side surfaces of the plastic lens, was carried out according to the following criteria.

[0222] (Occurrence of Whitening)

[0223] A: No whitening was observed.

[0224] B: Slight whitening was observed at the outer peripheral part of the plastic lens.

[0225] C: Clear whitening was observed at the outer peripheral part of the plastic lens.

[0226] (Occurrence of Bubbles)

[0227] A: No bubbles were observed.

[0228] B: Slight bubbles were observed at the outer peripheral part of the plastic lens.

[0229] C: Clear bubbles were observed at the outer peripheral part of the plastic lens.

[0230] (Occurrence of Wrinkles)

[0231] A: No wrinkles were observed.

[0232] B: Slight wrinkles were observed on the side surface of the plastic lens.

[0233] C: Clear wrinkles were observed on the side surface of the plastic lens.

[0234] (Occurrence of Adhesive Residue)

[0235] A: No adhesive residue was observed.

[0236] B: Slight adhesive residue was observed on the mold and / or the side surface of the plastic lens.

[0237] C: Clear adhesive residue was observed on the mold and / or the side surface of the plastic lens.

[0238] In any of the tests, the evaluations of A or B were judged to be at a level where there are no practical problems.

[0239] 3. Test Results

[0240] Regarding the evaluation results of the adhesive tape 1 for Examples 1 to 14 and Comparative Examples 1 to 7, they are shown in Tables 1 to 4.

[0241] [Table 1]

[0242]

[0243] [Table 2]

[0244]

[0245] [Table 3]

[0246]

[0247] [Table 4]

[0248]

[0249] As shown in Tables 1 to 3, it was confirmed that: in the adhesive tape 1 of Examples 1 to 14 using an adhesive composition containing a functional group-containing acrylic copolymer (A1 to A3, B to H) having a weight average molecular weight (Mw) of 1,100,000 or more and a molecular weight polydispersity (Mw / Mn) of 10.0 or less measured by gel permeation chromatography and a crosslinking agent that reacts with the functional group, and setting the dissolution rate in toluene adjusted to a temperature of 80°C to 48.0% or less and the deviation amount in the creep test to 0.15 mm or more and 0.50 mm or less, when molding high refractive index plastic lenses PL1 (refractive index 1.60) and PL2 (refractive index 1.67) by a short-time heating process, satisfactory results were obtained for each characteristic of the appearance represented by whitening.

[0250] In the comparison between Example 1 and Examples 4 to 7 where the acid value of the acrylic copolymer was the same at 14.8 mgKOH / g and only the content of the crosslinking agent was different, in Example 6 where the content of the crosslinking agent was the lowest at 1.4% by mass (NCO / COOH = 0.23), since the dissolution rate in toluene adjusted to a temperature of 80°C was 47.7%, which was greater than that of other examples, the amount of the adhesive layer 3 dissolved in the resin for plastic lens molding was slightly more, and whitening was slightly observed at the outer peripheral portions of the obtained plastic lenses PL1 and PL2. In addition, in Example 7 where the content of the crosslinking agent was the highest at 4.5% by mass (NCO / COOH = 0.72), since the deviation amount in the creep test was 0.15 mm, which was less than that of other examples, the cohesive force of the adhesive layer 3 was slightly greater, that is, the stress relaxation property was slightly worse, and wrinkles were slightly observed on the sides of the obtained plastic lenses PL1 and PL2.

[0251] In addition, in Example 9 where the acid value of the acrylic copolymer is as large as 37.1 mgKOH / g and the content of the crosslinking agent is as much as 4.5% by mass, since the deviation amount in the creep test is 0.15 mm, which is less than that of other examples, the cohesion of the adhesive layer 3 is slightly larger, that is, the stress relaxation property is slightly worse, and wrinkles are slightly observed on the sides of the obtained plastic lenses PL1 and PL2.

[0252] Furthermore, Example 13 in which the number of carbon atoms of the alkyl group of the (meth)acrylic acid alkyl ester as the main component of the acrylic copolymer is 8 and the content of the crosslinking agent is 3.7 parts by mass is compared with Example 5 in which the number of carbon atoms of the alkyl group of the (meth)acrylic acid alkyl ester as the main component of the acrylic copolymer is 12 and the content of the crosslinking agent is 3.7 parts by mass. Since the deviation amount in the creep test is as small as 0.18 mm, the cohesion of the adhesive layer 3 is slightly larger, that is, the stress relaxation property is slightly worse, and wrinkles are slightly observed on the sides of the obtained plastic lenses PL1 and PL2.

[0253] Furthermore, Example 14 in which the functional group of the acrylic copolymer is a hydroxyl group and the content of the crosslinking agent is 2.3 parts by mass is compared with Example 4 in which the functional group of the acrylic copolymer is a carboxyl group and the content of the crosslinking agent is 2.3 parts by mass. Since the deviation amount in the creep test is as small as 0.15 mm, the cohesion of the adhesive layer 3 is slightly larger, that is, the stress relaxation property is slightly worse, and wrinkles are slightly observed on the sides of the obtained plastic lenses PL1 and PL2.

[0254] From this, it is confirmed that the adhesive tape 1 of Examples 1 to 14 designed such that the dissolution rate in toluene adjusted to a temperature of 80 °C is 48.0% or less, the deviation amount in the creep test is 0.15 mm or more and 0.50 mm or less, using an adhesive composition containing a functional group-containing acrylic copolymer having a weight average molecular weight (Mw) of 1,100,000 or more and a molecular weight polydispersity (Mw / Mn) of 10.0 or less measured by gel permeation chromatography and a crosslinking agent that reacts with the functional group as the adhesive layer 3 is useful as an adhesive tape for molding a high refractive index plastic lens by a short-time heating process.

[0255] In contrast, as shown in Tables 3 to 4, it is confirmed that in Comparative Examples 1 to 7 where the adhesive layer 3 does not satisfy the constituent requirements of the present invention, the evaluation results of at least any one of whitening, wrinkles, bubbles, and adhesive residue are worse than those of Examples 1 to 14.

[0256] Specifically, in Comparative Example 1 using acrylic copolymer I with a weight-average molecular weight (Mw) as low as 753,000 and a polydispersity of molecular weight (Mw / Mn) as large as 17.1, due to the influence of low-molecular-weight components with insufficient crosslinking, the dissolution rate in toluene adjusted to a temperature of 80°C was 80.0%, which was extremely large compared to the examples. Therefore, the amount of the adhesive layer 3 dissolved into the plastic lens-forming resin increased, and whitening was clearly observed at the outer peripheral portions of the obtained plastic lenses PL1 and PL2. In addition, the deviation amount in the creep test was also 0.10 mm, which was extremely small compared to the examples. It is speculated that since the number of carbon atoms in the alkyl group of the (meth)acrylic acid alkyl ester as the main component was 4 and the functional group of the acrylic copolymer was a hydroxyl group, the cohesive force of the adhesive layer 3 was large, that is, the stress relaxation property was poor, and wrinkles were clearly observed on the sides of the obtained plastic lenses PL1 and PL2.

[0257] In addition, in Comparative Example 2 in which the content of the crosslinking agent was increased to 5.0% by mass relative to Comparative Example 1, although the dissolution rate in toluene adjusted to a temperature of 80°C was as low as 45.0%, the whitening at the outer peripheral portions of the obtained plastic lenses PL1 and PL2 was improved to a slightly observable level. However, since the deviation amount in the creep test also further decreased to less than 0.10 mm, the wrinkles on the sides of the obtained plastic lenses PL1 and PL2 were still not improved.

[0258] Furthermore, in Comparative Example 3 using acrylic copolymer J with a weight-average molecular weight (Mw) as low as 1,020,000 and a polydispersity of molecular weight (Mw / Mn) as large as 31.2, due to the influence of low-molecular-weight components with insufficient crosslinking, the dissolution rate in toluene adjusted to a temperature of 80°C was 75.8%, which was extremely large compared to the examples. Therefore, the amount of the adhesive layer 3 dissolved into the plastic lens-forming resin increased, and whitening was clearly observed at the outer peripheral portions of the obtained plastic lenses PL1 and PL2. In addition, the deviation amount in the creep test was 0.60 mm. It is speculated that since the acid value of the acrylic copolymer was 3.8 mgKOH / g, wrinkles were not generated on the sides of the obtained plastic lenses PL1 and PL2. It should be noted that regarding the adhesive residue, it was at a level slightly observable on the side of the mold after the adhesive tape 1 was peeled off.

[0259] Furthermore, in Comparative Example 4 using acrylic copolymer K with a weight-average molecular weight (Mw) as small as 672,000, a polydispersity of molecular weight (Mw / Mn) as large as 18.2, and containing 45% by mass of methyl acrylate with 1 carbon atom in the alkyl group of the (meth)acrylic acid alkyl ester and 50% by mass of butyl acrylate with 4 carbon atoms in the alkyl group of the (meth)acrylic acid alkyl ester, the dissolution rate in toluene adjusted to a temperature of 80 °C was particularly 31.0%. No whitening occurred at the outer peripheral portions of the resulting plastic lenses PL1 and PL2. It is speculated that this is because there is a difference between the solubility parameter (SP) value of methyl acrylate and the SP value of toluene. However, the deviation amount in the creep test was also 0.11 mm, which is small compared to the examples. It is speculated that this is because the functional group of the acrylic copolymer is a hydroxyl group and the number of carbon atoms in the alkyl group of the (meth)acrylic acid alkyl ester is small. Therefore, wrinkles were clearly observed on the sides of the resulting plastic lenses PL1 and PL2. Additionally, regarding the adhesive residue, it was clearly observable on the side of the mold after the adhesive tape 1 was peeled off. It is speculated that this is because the weight-average molecular weight (Mw) is as small as 672,000.

[0260] Furthermore, in Comparative Example 5 using acrylic copolymer A-4 with a weight-average molecular weight (Mw) of 1,240,000, which satisfies the scope of the present invention but has a polydispersity of molecular weight (Mw / Mn) as large as 16.7 and is outside the scope of the present invention, although the dissolution rate in toluene adjusted to a temperature of 80 °C was 51.6%, which is smaller than that in Comparative Example 1 and Comparative Example 3, this value is still larger compared to the examples. Therefore, the amount of the adhesive layer 3 dissolved in the plastic lens-forming resin increased, and whitening was clearly observed at the outer peripheral portions of the resulting plastic lenses PL1 and PL2.

[0261] Furthermore, in Comparative Example 6 using acrylic copolymer A-1 with a weight-average molecular weight (Mw) and a polydispersity of molecular weight (Mw / Mn) that satisfy the scope of the present invention, but with the deviation amount in the creep test adjusted to 0.10 mm or less by increasing the crosslinking agent content, although no whitening occurred at the outer peripheral portions of the resulting plastic lenses PL1 and PL2, wrinkles were clearly observed on the sides of the resulting plastic lenses PL1 and PL2.

[0262] Furthermore, in Comparative Example 7 using acrylic copolymer A-1 with a weight-average molecular weight (Mw) and a polydispersity of molecular weight (Mw / Mn) that satisfy the scope of the present invention, but with the dissolution rate in toluene adjusted to 49.5% by decreasing the crosslinking agent content, although no wrinkles occurred on the sides of the resulting plastic lenses PL1 and PL2, whitening was clearly observed at the outer peripheral portions of the resulting plastic lenses PL1 and PL2. It should be noted that regarding the adhesive residue, it was at a level where it was slightly observable on the side of the mold after the adhesive tape 1 was peeled off.

[0263] Symbol Explanation

[0264] 1: Adhesive tape, 2: Composite substrate, 3: Adhesive layer, 4: First substrate, 5: Inorganic thin film layer, 6: Bonding layer, 7: Second substrate, 10: First laminate, 20: Second laminate, 50: Mold, 100: Resin for plastic lens molding, C: Chamber.

Claims

1. An adhesive tape for plastic lens molding, which is an adhesive tape for plastic lens molding having a base material and an adhesive layer formed on the surface of the base material. The adhesive layer contains an acrylic copolymer having a functional group and a crosslinking agent that reacts with the functional group. The acrylic copolymer is a copolymer obtained by polymerizing a monomer mixture containing a monomer having a (meth)acryloyl group. The monomer mixture contains an alkyl (meth)acrylate, an ethylenically unsaturated monomer having a functional group, and other monomers. The other monomers are acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, vinyl propionate, vinyl chloride, alkyl vinyl ether, dimethylaminoethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, and methoxytriethylene glycol (meth)acrylate. The alkyl (meth)acrylate monomer is 60 to 99.3% by mass, the ethylenically unsaturated monomer having a functional group is 0.7 to 10% by mass, and the other monomers are 0 to 39.3% by mass. The acrylic copolymer has a weight-average molecular weight (Mw) of 1,100,000 or more and a polydispersity of the molecular weight, i.e., Mw / Mn, of 10.0 or less. The acrylic copolymer has a carboxyl group as a functional group, and the crosslinking agent is a polyisocyanate compound. The acrylic copolymer has an acid value of 5.0 to 75.0 mgKOH / g, and the ratio of the equivalent of the isocyanate group, i.e., NCO, of the polyisocyanate compound to the equivalent of the carboxyl group, i.e., COOH, of the acrylic copolymer, i.e., NCO / COOH, is 0.20 to 0.

80. The dissolution rate of the adhesive layer when immersed in toluene adjusted to a temperature of 80°C for 2 hours is 48.0% or less, and The deviation amount of the adhesive tape after 800 minutes in a creep test at a temperature of 40°C and a load of 0.5 kg is 0.15 mm or more and 0.50 mm or less. The plastic lens has a refractive index of 1.59 or more.

2. The adhesive tape for plastic lens molding according to claim 1, wherein the monomer as a raw material of the acrylic copolymer contains an alkyl (meth)acrylate having an alkyl group with 5 to 18 carbon atoms.

3. The adhesive tape for plastic lens molding according to claim 1 or 2, wherein the dissolution rate of the adhesive layer when immersed in toluene adjusted to a temperature of 80°C for 2 hours is 38% or less.

4. The adhesive tape for plastic lens molding according to claim 1 or 2, wherein the deviation amount of the adhesive tape after 800 minutes in the creep test is 0.20 mm or more and 0.50 mm or less, and the plastic lens is a thiourethane resin.

5. The adhesive tape for plastic lens molding according to claim 1 or 2, wherein the base material is a composite base material formed by laminating a sheet-like first base material, an inorganic thin film layer, an adhesive layer, and a sheet-like second base material in this order.

6. The adhesive tape for plastic lens molding according to claim 1 or 2, wherein the adhesive tape has a water vapor transmission rate according to JIS K 7129 of 1.5 g / (m 2 ·24 h) or less.

7. A method for molding a plastic lens, which comprises: Chamber formation step: A pair of molds are arranged opposite to each other with a predetermined interval therebetween, and an adhesive tape for plastic lens molding according to any one of claims 1 to 6 is adhered to the outer peripheral portions of the two molds, and the opening of the space formed between the two molds is sealed to form a chamber for filling a polymeric raw material for a plastic lens; Polymeric raw material filling step: A polymeric raw material for a plastic lens having a refractive index of 1.59 or more is filled into the chamber; and Polymerization step: Polymerizing the polymeric raw material.

8. The molding method of the plastic lens according to claim 7, wherein the polymerization conditions in the polymerization step include: A polymerization start temperature of 45°C or more and 65°C or less, a polymerization final temperature of 130°C or more and 150°C or less, and a heating rate to reach the polymerization final temperature of 0.10°C / minute or more and 0.45°C / minute or less.

9. The method for molding a plastic lens according to claim 7 or 8, wherein the plastic lens is a thiourethane-based resin.

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