JP2017081160A - Functional sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional sheet that has a good appearance while maintaining the excellent functionality; and further to provide a functional molded article.SOLUTION: Provided is a functional sheet having a functional layer between 1 pair of optical sheets or films, on at least one surface of which a protective film for protecting the surface is laminated, and in which the protective film comprises at least 2 layers or more and in which at least 1 layer is a film (first film layer) with a melting point of 100°C or more and less than 125°C for bonding to the functional sheet and at least 1 layer is a film (second film layer) with a melting point of 150°C or more and 175°C or less disposed on the outer layer side.SELECTED DRAWING: None

Description

  The present invention relates to a functional sheet having a functional layer between a pair of optical sheets or optical films made of polycarbonate resin or the like. Specifically, the present invention relates to a functional sheet that can be die-cut into a desired shape while protecting the appearance of the optical sheet or optical film surface made of polycarbonate resin or the like.

  In recent years, mainly in the United States, the demand for plastic substrates using transparent and excellent impact-resistant polycarbonate for sunglasses having anti-glare properties and the like is rapidly increasing. In such plastic sunglasses, various methods for adjusting the antiglare property by imparting a polarizing function and a photochromic function have been studied. Such sunglasses are manufactured by the following method.

  For example, as a method of laminating a functional layer having antiglare properties between two plastic sheets or films, a method of laminating a photochromic layer between two polycarbonate sheets is known (see Patent Document 1). Yes. Specifically, a photochromic coating solution containing a solvent is applied to one plastic sheet, dried by passing it through a dryer at a specific temperature at a specific speed, and then the other plastic sheet is joined. A method (a method for producing a laminate) is shown. According to this method, a functional sheet having a photochromic layer with excellent smoothness can be produced continuously.

  A method of laminating a polarizing layer between two polycarbonate sheets (see Patent Document 2) is also known. Specifically, a method of laminating a polycarbonate film or a sheet on both sides of a polarizing thin layer in which a dichroic dye is oriented on a polymer film is shown. According to this method, a functional sheet having a polarizing layer with excellent smoothness can be produced.

  Furthermore, the functional sheet having the photochromic layer or the polarizing layer is used in a heating environment (under a temperature near the glass transition temperature of the laminate) using a mold or the like that has been dug into a desired shape in advance. ) Under a pressure or a reduced pressure (vacuum), it can be processed into a desired shape by performing a heat bending process. In addition, the functional sheet is usually die-cut before or after the above-described heat bending process, in a desired shape.

  On the other hand, synthetic plastic sheets such as polycarbonate are known to be easily scratched, soiled, or contaminated with foreign matter. In order to protect the surface of the synthetic plastic sheet during hot bending, storage, and transportation. It is known that a protective film is attached to the surface of a synthetic plastic sheet and used for hot bending. As such a protective film, for example, a polyolefin film such as polyethylene or polypropylene is used.

  For example, Patent Document 3 proposes a protective film having a two-layer structure of a low-density polyethylene layer and an ethylene-vinyl acetate copolymer (EVA) layer as a protective film for integrated thermal bending for an acrylic substrate. However, the protective film has a problem in heat resistance, and when used as a protective sheet on the surface of the polycarbonate resin, welding of the low density polyethylene layer to the mold occurs during heating during hot bending. There was a problem.

  Further, in order to improve heat resistance during hot bending, the first film comprises at least a first film layer disposed on the side in contact with the mold and a second film layer disposed on the side in contact with the polycarbonate sheet. A protective film is proposed which is a polyolefin film layer having a melting point of 150 ° C. or higher and a polyolefin film layer having a melting point of 125 to 145 ° C. of the second film layer (see Patent Document 4). By using this protective film, it is possible to suppress welding of the protective film to a mold or a polycarbonate sheet after hot bending.

  Furthermore, in order to suppress the heat resistance improvement during the heat bending process and the occurrence of thread-like defects during the die cutting process, the protective film has one base material layer and one adhesive layer. It has at least two melting peaks, a melting peak (A) of 105 ° C. or more and 130 ° C. or less and a melting peak (B) of 160 ° C. or more and less than 175 ° C., and the area ratio [(A) / (B)] of the melting peaks is A protective film of 35/65 or more and 80/20 or less has been proposed (see Patent Document 5). By using this protective film, it is possible to suppress thread-like defects during die cutting and to suppress welding of the protective film to a mold or a polycarbonate sheet after hot bending.

Japanese Patent No. 4661017 Japanese Patent No. 2130732 JP-A-8-192501 JP 2003-145616 A Japanese Patent No. 5724174

  However, when die-cutting to a lens size or the like is performed using the protective film described in Patent Document 4, thread-like foreign matter is generated at the end of the die-cut sheet, and Patent Document 4 or 5 In any case of the protective films described, the inventors have found that the protective film may float (peel) at the end. Furthermore, the protective film described in Patent Document 4 is in close contact with the functional sheet via an adhesive layer, and the protective film described in Patent Document 5 is added with a tackifier component such as a hydrogenated terpene resin. It is in close contact with the functional sheet via the adhesive layer, and the adhesive strength of the protective film to the polycarbonate sheet becomes too strong after hot bending, making it difficult to peel off, or bubbles are generated in the protective film during hot bending As a result, the inventors of the present invention have also found that appearance defects may occur on the polycarbonate sheet surface.

  Therefore, the object of the present invention is to reduce the appearance of the thread-like foreign matter and the protective film at the end after the die-cutting process while maintaining excellent functionality, and to peel off the protective film after hot bending. It is to provide a functional sheet with good appearance and few appearance defects, and also a functional molded body.

  The present inventors have intensively studied to solve the above problems. As a result, by adjusting the properties of the protective film to be attached to at least one surface of the functional sheet, the protective film can be used without using an adhesive layer to which a tackifying component such as an adhesive layer or a hydrogenated terpene resin is added. Has been found to be able to adhere to the functional sheet. And, when the functional sheet with the protective film adhered thereto is subjected to die cutting to a lens size or the like, it is possible to suppress the thread-like foreign matter generated at the end of the die cut sheet and the float of the protective film, The inventors have found that it is possible to maintain good peelability of the protective film even after the hot bending process and to suppress the generation of bubbles in the protective film even after the hot bending process, thereby completing the present invention.

That is, the present invention is a functional sheet in which a protective film for protecting the surface is laminated on at least one surface of a functional sheet having a functional layer between a pair of optical sheets or films,
The protective film comprises at least two layers, and at least one layer is a film (first film layer) bonded to a functional sheet having a melting point of 100 ° C. or higher and lower than 125 ° C., and at least one layer is 150 ° C. or higher and 175 ° C. It is the functional sheet which affixed the protective film which consists of a film (2nd film layer) arrange | positioned at the outer layer side of said 1st film layer which has the following melting | fusing points.

  The functional sheet of the present invention can suitably adopt the following aspect.

  (1) In the functional sheet described above, the number of thread-like foreign matters having a length of 2 mm or more generated at the end of the functional sheet after the die-cutting step to be molded into a desired shape is 20 or less.

  (2) The functional layer of the functional sheet has a photochromic function and / or a polarizing function.

  (3) Further, the protective film is at least one selected from polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-α-olefin copolymer and propylene-α-olefin copolymer, or a mixture of two or more. Product is used for each layer, and the thickness of the protective film is 10 to 150 μm.

  By using the functional sheet of the present invention, it is possible to suppress the occurrence of thread-like foreign matter generated at the end of the functional sheet after the die cutting process, and at the end of the functional sheet after the die cutting process. The floating of the generated protective film can also be suppressed. Furthermore, the functional sheet of the present invention has good peelability of the protective film after hot bending, and can effectively suppress poor appearance of the functional sheet surface such as polycarbonate sheet that occurs during hot bending. It is possible to obtain a secondary processed product such as a plastic lens having functionality. Although details are unknown as the reason why such an effect is obtained, the present inventors presume as follows.

  That is, the functional sheet of the present invention has a configuration in which an optical sheet such as a polycarbonate sheet or an optical film is laminated on both surfaces of the functional layer, and a protective film is further laminated on at least one surface of the optical sheet or optical film. Yes. Usually, since the functional sheet of the present invention is die-cut and used for lens size etc., the appearance and shape after die-cutting work to the workability and yield at the time of secondary processing such as subsequent thermal bending. Affect. In other words, after the functional sheet is die-cut, if thread-like foreign matter or protective film floats at the end of the functional sheet, that portion is transferred to the optical sheet or optical film surface during secondary processing such as thermal bending. It is estimated that appearance defects such as dents occur. Further, since the functional sheet of the present invention is also subjected to secondary processing such as thermal bending as described above, the heat resistance of the protective film affects the peelability and appearance of the protective film after thermal bending. To do. In other words, when the protective film is adhered to the functional sheet via the adhesive layer, the adhesiveness of the protective film to the functional sheet is excessively improved by heating in the thermal bending process of the functional sheet, and thermal bending is performed. Removability of the protective film after processing is reduced, resulting in unseparated residue, or generation of bubbles in the layer during heating in the heat bending process, so that the traces of the bubbles are transferred to the surface of the functional sheet and dents, etc. It is presumed that the appearance defect will occur.

  The functional sheet of the present invention can suppress the lifting of the filamentous foreign matter and the protective film generated at the end of the functional sheet after die cutting, and further suppresses the fusion of the protective film and the generation of bubbles during the hot bending process. Therefore, it is possible to suppress appearance defects such as dents generated on the surface of the optical sheet or optical film even when heat bending is performed, and to maintain good peelability of the protective film even after heat bending I guess.

  The present invention is a functional sheet having a protective film for protecting the surface on at least one surface of a functional sheet in which a functional layer is bonded between a pair of optical sheets or optical films, It is possible to suppress thread-like foreign matter and protective film floating generated at the end of the functional sheet after the die-cutting process for molding the functional sheet into a desired shape, and also a good protective film even after hot bending This is characterized in that the release property of the protective film can be maintained and the generation of bubbles in the protective film can be suppressed even after hot bending. By using such a functional sheet, it is possible to suppress the appearance defect in the heat bending process.

  Here, the thread-like foreign matter means a foreign matter having a length of 2 mm or more generated at the outer edge portion (end portion) when the functional sheet is cut into a circular shape. In the functional sheet of the present invention, Is preferably 20 or less of the above-mentioned thread-like foreign matters when die-cut to a diameter of 80 mm. For the measurement of the thread-like foreign matter, using a digital microscope (manufactured by Keyence Corporation, VHX-2000), confirm the thread-like foreign matter having a length of 2 mm or more present on the outer periphery of the sheet punched into a circular shape having a diameter of 80 mm. It can be measured by counting the number of filamentous foreign matter.

  Hereinafter, the functional sheet of the present invention will be described.

(Protective film)
The protective film in the functional sheet of the present invention is used to protect the surface of the optical sheet or the optical film from scratches and dirt by being attached to the surface of the optical sheet or the optical film made of a synthetic resin such as polycarbonate. Is.

  As described above, the protective film of the present invention comprises at least two layers, and is a film (first film) that is bonded to a functional sheet having a melting point of at least 100 ° C. and less than 125 ° C., particularly a melting point of 100 ° C. to 123 ° C. A protective film comprising a film (second film layer) disposed on the outer layer side of the first film layer, wherein at least one layer has a melting point of 150 ° C. or higher and 175 ° C. or lower. By using such a protective film, the functional sheet of the present invention can suppress the occurrence of thread-like foreign matter at the end of the die-cut functional sheet. In addition, if the protective film of the present invention is used, the adhesion with the functional sheet surface is good, and even after the die cutting process, the protective film can be prevented from floating at the end of the die cut functional sheet. It becomes possible. Furthermore, even after being heated at the time of secondary processing such as hot bending, the protective film has a peelability equivalent to that before heating and can suppress appearance defects such as bubbles.

  The melting point of the protective film is the peak top when measured by the method described in JIS K7121 using a DSC (suggested scanning calorimeter).

  When a resin film made of a resin having a melting point of less than 100 ° C. for the protective film (first film layer) to be bonded to the functional sheet of the present invention is used as the protective film, the protective film is protected after a step where heat is applied such as heat bending. The adhesive force between the film and the functional sheet becomes too strong, which may hinder operability and the protective film may be fused and remain on the functional sheet surface. In addition, when the melting point of the first film layer is 125 ° C. or higher, the adhesive strength with the functional sheet is reduced, so that the protective film is likely to float at the end of the functional sheet after die cutting. . However, from the viewpoint of the adhesive strength to the functional sheet, the melting start temperature of the first film layer is preferably about 80 to 90 ° C. In addition, if the melting point of the film (second film layer) disposed on the outer layer side of the protective film is lower than less than 150 ° C., fusion to the mold surface is likely to occur during hot bending, resulting in poor molding and the like. When a resin film made of a resin exceeding 175 ° C. is used as a protective film, it becomes difficult to follow the deformation of the functional sheet at the time of thermal bending, so there is a problem in the processing stability of the functional sheet. May occur.

  As the resin used for the protective film (first film layer) bonded to the functional sheet of the present invention, a known resin having a melting point of 100 ° C. or higher and lower than 125 ° C. can be used without any limitation. From the viewpoint of suppressing lifting of the protective film at the end of the die-cut functional sheet, polyolefin, polyolefin copolymer, ethylene vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-α-olefin copolymer. A polymer, an ethylene-methacrylic acid copolymer, and the like are preferable, and a polyethylene elastomer or the like may be included. Among these, since it has good adhesion to the surface of the functional sheet, that is, the surface of the optical sheet or optical film made of a synthetic resin such as polycarbonate, low density polyethylene, ethylene-propylene copolymer, ethylene It is preferably at least one selected from vinyl acetate copolymers and ethylene-α-olefin copolymers, or a mixture of two or more. The low density polyethylene of the present invention is a linear low density polyethylene, a branched low density polyethylene, or a blend thereof.

  Moreover, it is preferable that tackifying components, such as a terpene resin, a hydrogenated terpene resin, a rosin resin, and a phenol resin, are not added to the first film layer of the present invention. By adding the tackifying component to the first film layer, the adhesion of the protective film to the functional sheet is improved, but the peelability tends to decrease because the adhesion of the protective film after the heat bending process becomes stronger. Because the heat resistance is insufficient, bubbles are generated in the first film layer, and the traces of the bubbles are transferred to the surface of the functional sheet, so that appearance defects such as dents are likely to occur.

  In addition, between the 1st film layer of this invention and a functional sheet, the adhesive layer to which the said tackifying component was added, and also acrylic type, silicone type, long chain alkyl type, stearic acid type, or urethane No adhesives such as system are laminated. When the pressure-sensitive adhesive is laminated between the functional sheet and the first film layer, the adhesion of the first film layer to the functional sheet is greatly improved, but the adhesiveness of the protective film after hot bending is also greater. Since it becomes strong, the decrease in peelability becomes remarkable. In addition, the generation of bubbles in the pressure-sensitive adhesive layer due to insufficient heat resistance becomes intense, and the appearance defect such as a dent resulting from the transfer of the bubble marks on the surface of the functional sheet becomes more prominent.

  As the first film layer of the present invention, the tensile strength is 30 MPa or less, particularly 20 MPa from the viewpoint of good cutting with respect to the blade used at the time of die cutting and suppressing the occurrence of thread-like foreign matters at the end of the die cut functional sheet. It is preferable to use a film made of the following resin. The reason is not clear, but when a resin film with a tensile strength exceeding 30 MPa is used, it is estimated that the cutting with respect to the blade used at the time of die-cutting is bad and the resin film is stretched and torn so as to be cut. doing. The tensile strength is more preferably 20 MPa or less from the viewpoint of suppressing the generation of thread-like foreign matters when the mold is punched.

  In addition, as a resin used for a film (second film layer) disposed on the outer layer side of the first film layer of the protective film of the present invention, that is, a film disposed on the side in contact with the mold at the time of thermal bending, A known resin having a melting point of 150 ° C. or higher and 175 ° C. or lower can be used without any limitation. From the viewpoint of heat resistance, it is composed of polypropylene, ethylene-propylene copolymer, propylene-α-olefin copolymer, or the like. A polyolefin film is preferred.

  The polyolefin film layer (polypropylene, ethylene-propylene copolymer, propylene-α-olefin copolymer, etc.) preferably used for the second film layer has a tensile strength exceeding 30 MPa, By laminating a resin film with a tensile strength of 30 MPa or less on the first film layer, the tensile strength of the first film layer is relaxed, and it is possible to suppress thread-like foreign matter at the end of the functional sheet that occurs during die cutting. It becomes.

  Also, any adhesive such as acrylic, silicone, long chain alkyl, stearic acid, or urethane as described above is laminated between the first film layer and the second film layer of the present invention. Not. When the pressure-sensitive adhesive is laminated between the first film layer and the second film layer, the adhesiveness between the first film layer and the second film layer is improved, but the pressure-sensitive adhesive is heated by heat during the bending process. The adhesive film is not used in the protective film of the present invention because it protrudes, contaminates the mold, and may cause poor appearance on the surface of the functional sheet.

  The protective film of the present invention comprises at least two or more layers, and has at least one first film layer and at least one second film layer, but between the first film layer and the second film layer. It is more preferable to have another film layer (hereinafter also referred to as “third film layer”). Even when a thick protective film is manufactured by laminating the third film layer, a protective film having a uniform final film thickness can be manufactured. When the layer is applied to a polycarbonate sheet or the like, it can be applied with a uniform film thickness. Moreover, resin used for the 3rd film layer of this invention is suitably selected from resin used for the above-mentioned 1st film layer and 2nd film layer.

  The said protective film of this invention is affixed on the surfaces, such as a polycarbonate sheet, and is used for secondary processes, such as a heat bending process using the metal mold | die etc. which were heated as it is. When a polycarbonate sheet, which will be described later, is used as the optical sheet or optical film for the functional sheet of the present invention, the glass transition temperature of the polycarbonate sheet is 145 to 150 ° C. Secondary processing such as is performed. Therefore, the protective film of the present invention is mainly from the viewpoint of the heat resistance during the secondary processing, the flexibility during the heat bending process, and the adhesiveness between the polycarbonate sheet and the protective film. The area ratio [(I) / (II)] between the heat of fusion (I) of 135 ° C. or less and the heat of fusion (II) of 145 ° C. or more and 175 ° C. or less mainly derived from the second film layer is 60/40 to The layer structure is preferably formed so as to be in the range of 99/1.

  The heat of fusion of the protective film can be measured by a method described in JIS K7121 using a DSC (suggested scanning calorimeter). In addition, although the said protective film has a 2 or more layer structure as above-mentioned, in the measurement of a calorie | heat amount, it measures with a 2 or more layer structure, without isolate | separating each layer. The specific measurement method is as follows.

<DSC measurement method>
In accordance with the measurement method of JIS K7121, 5 mg of a test piece of a protective film is weighed in an aluminum container and mounted on a differential scanning calorimeter (DSC8230 manufactured by Rigaku), and the heating rate is 10 ° C. from 0 ° C. in a nitrogen gas atmosphere. Measured by / min.

Further, the protective film used in the present invention has a foreign matter content in which the size of the foreign matter contained in the protective film is more than 100% and less than 200% with respect to the thickness of the protective film. , Preferably 10 or less per 100 cm ² .

  That is, since the protective film is peeled off during use, an inexpensive low-grade resin film is generally used. Such low-grade films are hard, white and cloudy called fish eyes (so-called “butsu”) due to insufficient melting of the raw material resin, temperature unevenness at the time of film formation, etc. It contains a lot of visible optical impurity particles, etc., and the present inventors have a dent on the surface of the functional layer of the functional sheet at the time of thermal bending corresponding to a large size of such optical impurity particles. I think it will be formed.

  Specifically, the functional sheet in the present invention is a functional sheet in which a functional layer having functionality such as photochromic characteristics and polarization characteristics is bonded between a pair of optical sheets or optical films, An optical sheet such as a polycarbonate sheet or an optical film is laminated on both surfaces of the functional layer. For the functional layer of the present invention, urethane resin or polyvinyl alcohol resin is used, but these resins have a lower softening point than the polycarbonate sheet, and heat bending of the functional sheet to which the protective film containing the foreign matter is attached. When the processing is performed, the functional layer in the center is softened, and the functional layer during processing is pressed by pressure from both sides. It is presumed that a recess corresponding to the shape of the foreign matter is formed during processing. Therefore, it is speculated that by controlling the size and number of foreign matters contained in the protective film, it is possible to suppress the formation of dents according to the shape of the foreign matters at the time of thermal processing occurring on the functional sheet surface. Yes.

In terms of the effect of suppressing the appearance defect after the heat processing, the size of the foreign matter present in the protective film is more than 100% and less than 180% in the depth direction with respect to the thickness of the protective film. Preferably, it is in a range of more than 100% and less than 150%. From the same point, the number of foreign substances is preferably 5 or less, and most preferably 3 or less, per 100 cm ² of the protective film.

The foreign matter can be measured by the following method. First, using a digital microscope (manufactured by Keyence Corporation, VHX-2000), the shape of foreign matter contained in 100 cm ^{2 of} the protective film is confirmed. And it is measurable by counting the number of confirmed foreign matters. In addition, the size in the planar direction and the depth direction can be measured by looking at the surface roughness of the protective film where foreign matter is present with a laser microscope (VK-8700 / 8710, manufactured by Keyence Corporation). it can.

  The thickness of the protective film is preferably 10 to 150 μm from the viewpoint of workability in the secondary processing and suppression of occurrence of defects due to the protective film. When the thickness of the protective film is less than 10 μm, a wrinkle defect occurs during the thermal bending process, or the shape of the foreign matter attached to the mold or the protective film surface during the thermal bending process is easily transferred to the functional sheet surface. In addition, when the thickness of the protective film is greater than 150 μm, thread-like foreign matters are likely to be generated during the die-cutting process, it is difficult to bend into a desired shape during the heat bending process, and the heat resistance is low. In this case, the film layer protrudes from the polycarbonate sheet or the like, and it tends to cause poor appearance. The thickness of the protective film is more preferably 25 to 110 μm. Among these, the protective film of the present invention is preferably composed of a second film layer disposed on the side in contact with the mold and a first film layer disposed on the side in contact with the functional sheet, the second film layer, The thickness of each of the first film layers is preferably the following value. That is, the thickness of the second film layer is preferably 5 to 100 μm, more preferably 20 to 100 μm, and the thickness of the first film layer is preferably 5 to 100 μm, and 5 to 30 μm. Is more preferable, and it is most preferable that it is 10-30 micrometers.

  Furthermore, in order to suppress the adhesion of dust and dust to the surface of the protective film, and further to suppress the generation of static electricity when the protective film is peeled off, the protective film is used to suppress the adhesion of dust and dirt to the functional sheet itself. One or a plurality of layers may be coated with a conductive material such as polypyrrole, or an antistatic agent such as a surfactant may be added to the protective film. In addition, various additives such as antioxidants and light stabilizers can be added to the protective film of the present invention or applied to the surface to stably stabilize the optical sheet or optical film or bent product over a long period of time. It can also be stored.

  The protective film used for this invention can be obtained by making it adhere | attach, coextruding the film which comprises each layer.

(Optical sheet or optical film)
As the optical sheet or optical film in the functional sheet of the present invention, a light-transmitting sheet or film can be used without particular limitation, but it is made of a resin from the viewpoint of easy availability and ease of processing. Is preferably used. Examples of resins suitable as raw materials for optical sheets or optical films include polycarbonate resins, polyethylene terephthalate resins, nylon resins, triacetyl cellulose resins, acrylic resins, urethane resins, allyl resins, epoxy resins, and polyvinyl alcohol resins. . Among these, polycarbonate resin is particularly preferable because it has good adhesiveness and high applicability to the injection molding method. These optical sheets or films can be used in combination with different ones. In addition, when using the dyed optical sheet or film, the dyed one can be used originally, or after producing the functional sheet of the present invention, the surface optical sheet or film is dyed. Also good.

  The polycarbonate resin used for the optical sheet or the optical film is an aromatic polycarbonate resin mainly composed of an aromatic phenol having a general bisphenol A skeleton, and further, an aromatic polycarbonate resin and a polyester resin, polysiloxane, polyamide, A polymer alloy with a synthetic resin such as polystyrene, polyolefin, acrylic, amorphous polyolefin, ABS, or AS can be used. Specifically, it is preferable to use a polycarbonate resin containing structural units derived from the following diols.

(Where
R _{1 to} R ₄ are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 6 carbon atoms. A cycloalkoxy group having 20 carbon atoms or an aryloxy group having 6-20 carbon atoms,
A is an oxygen atom, sulfur atom, sulfoxide group, sulfone group, carbonyl group, alkylene group having 1 to 20 carbon atoms, alkylidene group having 2 to 20 carbon atoms, cycloalkylene group having 6 to 20 carbon atoms, or 6 to 6 carbon atoms. A cycloalkylidene group having 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or an alkylene arylene alkylene group having 6 to 20 carbon atoms. )

(Where
R _{5 to} R ₈ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, or a substituted or unsubstituted group. Represents an aryl group having 6 to 20 carbon atoms,
B represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms;
m and n are each independently an integer of 0 to 5. )

(Where
R ₉ is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
R ₁₀ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,
p is an integer of 1 to 3. )

(Where
Y is an alkylene group having 2 to 10 carbon atoms or an oxyalkylene group having 2 to 10 carbon atoms,
q is an integer of 1-10. )

  The polycarbonate resin used for the optical sheet or the optical film preferably has a weight average molecular weight of 10,000 to 200,000, more preferably 15,000 to 80,000.

  Polyester resins used for optical sheets or optical films include polyvalent carboxylic acids such as terephthalic acid and 2,6-naphthalenedicarboxylic acid, ethylene glycol, 1,3-propanediol, and 1,4-butanediol. A polycondensate with a polyalcohol such as 1,4-cyclohexanedimethanol is preferred from the viewpoints of strength and transparency. Among these, polyethylene terephthalate composed of terephthalic acid and ethylene glycol is preferable.

  Moreover, the polyamide resin used for an optical sheet or an optical film is a polymer formed by bonding a large number of monomers by amide bonds, and n-nylon, n, m-nylon and the like are preferably used. n-Nylon can be obtained by a ring-opening polycondensation reaction of ε-caprolactam, undecane lactam, lauryl lactam and the like. n, m-Nylon can be obtained by copolycondensation reaction of diamines such as tetramethylenediamine, hexamethylenediamine, nonanediamine, and methylpentadiamine with dicarboxylic acids such as adipic acid, sebacic acid, terephthalic acid, and isophthalic acid. I can do it. Among these, nylon 6 obtained by ring-opening polycondensation reaction of ε-caprolactam, nylon 6,6 obtained by copolycondensation reaction of hexamethylenediamine and adipic acid, and the like are preferable.

  Moreover, the cellulose resin used for an optical sheet or an optical film is a resin in which β-glucose molecules are linearly polymerized by glycosidic bonds, and examples thereof include acetyl cellulose, diacetyl cellulose, and triacetyl cellulose.

  The polyacrylic resin used in the optical sheet or optical film is a polymer of acrylic acid ester or methacrylic acid ester, and is a methacrylate polymer mainly composed of methacrylates such as methyl methacrylate and cyclohexyl methacrylate. Alternatively, a copolymer is preferable from the viewpoints of hardness, strength, transparency, and the like.

  Further, urethane resins used for optical sheets or optical films include polyisocyanate compounds such as aromatic isocyanate, alicyclic isocyanate, and aliphatic isocyanate, polycarbonate polyol, polyester polyol, polycaprolactone polyol, and polyether polyol. A commercially available urethane resin comprising a chain extender such as a polyol compound, a low molecular weight diol, and a diamine compound can be used.

  The polyolefin resin used for the optical sheet or the optical film is a resin synthesized by using olefins such as ethylene and propylene and alkenes as unit molecules, and in addition to polyethylene and polypropylene, a polycycloolefin resin may also be used. I can do it.

  As a suitable thickness of the optical sheet or film used in the present invention, 100 to 1500 μm is preferable, and 200 to 1000 μm is more preferable. These optical sheets or films can be used in combination with different thicknesses.

Moreover, the coating layer may be formed in the surface (upper surface and lower surface) of the optical sheet and film of this invention. The coating layer comprises a water-dispersible polymer such as water-dispersed polyurethane resin, water-dispersed polyester resin, water-dispersed acrylic resin, water-dispersed polyurethane / acrylic resin; among the water-dispersible polymers, a polymer having a carbonyl group and a hydrazide compound A crosslinked product of a water-soluble polymer such as polyvinyl alcohol; a polymerizable monomer having a (meth) acrylic group and / or an epoxy group, a (meth) acrylic group, a vinyl group, an amino group, and a mercapto group. Of a hydrolyzable organosilicon compound having a group capable of forming a silanol group or a urethane having a polymerizable group selected from a group that can be hydrolyzed to form a silanol group, a (meth) acrylate group, an epoxy group, and a vinyl group Composition of urea resin; propenyl ether group-containing compound, polyene compound and Ene / thiol compositions comprising ol compound, such as light-curable composition comprising an oxetane compound, a resin, crosslinked, may be formed from the composition. By forming the coating layer on the outermost surface (the side where no photochromic adhesive sheet is present), a (meth) acrylate-based monomer composition, an allyl-based monomer composition, a thiourethane-based monomer composition, a urethane-based monomer composition The laminated sheet of the present invention can be embedded in a monomer composition that forms a thermosetting resin (optical substrate) such as a thioepoxy monomer composition. As a result, it is possible to obtain an optical article in which the laminated sheet is embedded in the thermosetting resin (optical substrate) having good adhesion between the thermosetting resin (optical substrate) and the laminated sheet. .
Next, the functional layer of the present invention will be described. The functional layer of the present invention is not particularly limited as long as it is a layer that imparts antiglare properties, but may be at least one functional layer selected from a functional layer having photochromic properties and a functional layer having polarization properties. preferable.

(Functional layer with photochromic properties)
In the functional sheet of the present invention, the functional layer having photochromic properties is preferably an adhesive layer containing a urethane resin and a photochromic compound (hereinafter also referred to as “photochromic adhesive layer”), and the photochromic adhesive layer includes a urethane resin and a photochromic adhesive layer. It comprises a photochromic compound.

  The photochromic adhesive layer of the present invention may be a single layer or may be formed from a plurality of layers. In the case of a single layer, an adhesive layer containing the urethane resin and the photochromic compound may be used. In the case of a plurality of layers, the second adhesive layer may be laminated on both surfaces of the first adhesive layer containing the urethane resin and the photochromic compound.

  In addition, the thickness of the photochromic adhesive layer in the functional sheet to be obtained is not particularly limited, but when it is a single layer, it is preferably 5 to 100 μm. Moreover, when it is set as the structure of 2nd contact bonding layer / 1st contact bonding layer / 2nd contact bonding layer, it is preferable that a 1st contact bonding layer is 5-100 micrometers, More preferably, it is 10-50 micrometers, It is preferable that a layer is 2-40 micrometers, More preferably, it is 5-15 micrometers.

  Hereinafter, each component which comprises the said photochromic contact bonding layer is demonstrated.

(Urethane resin)
The urethane resin, which is a constituent component of the photochromic adhesive layer, is used for the purpose of bonding an optical sheet or an optical film such as a pair of polycarbonate sheets on both sides. The urethane resin may be either a thermoplastic resin or a thermosetting resin.

  The urethane resin is not particularly limited as long as it is a resin having a urethane bond in the molecule and can join a pair of optical sheets or films. Specifically, a urethane resin obtained from a diisocyanate compound, a polyol compound, and a chain extender can be used. Among these, a urethane-urea resin using diamine or triamine as a chain extender is particularly preferable. By using diamine or triamine as a chain extender, a urea bond (—R—NH—CO—NH—) is introduced into the urethane resin to form a urethane-urea resin.

(Diisocyanate compound)
As said isocyanate compound, it is an isocyanate compound which has two or more isocyanate groups in a molecule | numerator, and an aliphatic isocyanate compound, an alicyclic isocyanate compound, an aromatic isocyanate compound, and a mixture thereof are used. Among these, it is preferable to use an aliphatic isocyanate compound and / or an alicyclic isocyanate compound from the viewpoint of weather resistance. For the same reason, it is preferable that 30 to 100% by mass, particularly 50 to 100% by mass of the diisocyanate compound is an aliphatic diisocyanate compound.

Specifically, aliphatic such as tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate, octamethylene-1,8-diisocyanate, 2,2,4-trimethylhexane-1,6-diisocyanate Diisocyanate compound;
Cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 2,4-methylcyclohexyl diisocyanate, 2,6-methylcyclohexyl diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 4,4 ′ -Methylenebis (cyclohexyl isocyanate) isomer mixture, hexahydrotoluene-2,4-diisocyanate, hexahydrotoluene-2,6-diisocyanate, hexahydrophenylene-1,3-diisocyanate, hexahydrophenylene-1,4-diisocyanate 1,9-diisocyanato-5-methylnonane, 1,1-bis (isocyanatomethyl) cyclohexane, 2-isocyanato-4-[(4-isocyanate Preparative cyclohexyl) methyl] -1-methyl-cyclohexane, 2- (3-isocyanatopropyl) cyclohexyl isocyanate, alicyclic diisocyanate compounds such as norbornane diisocyanate;
Phenylcyclohexylmethane diisocyanate, 4,4′-methylenebis (phenylisocyanate) isomer mixture, toluene-2,3-diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, phenylene-1,3- Diisocyanate, phenylene-1,4-diisocyanate, 1,3-bis (isocyanatomethyl) benzene, xylylene diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, diphenyl ether diisocyanate, 1,3-diisocyanatomethylbenzene, 4, 4′-diisocyanato-3,3′-dimethoxy (1,1′-biphenyl), 4,4′-diisocyanato-3,3′-dimethylbiphenyl, 1,2-diisocyanatobenzene, 1,4 Bis (isocyanatomethyl) -2,3,5,6-tetrachlorobenzene, 2-dodecyl-1,3-diisocyanatobenzene, 1-isocyanato-4-[(2-isocyanatocyclohexyl) methyl] 2-methyl Aromatic diisocyanate compounds such as benzene, 1-isocyanato-3-[(4-isocyanatophenyl) methyl) -2-methylbenzene, 4-[(2-isocyanatophenyl) oxy] phenyl isocyanate, diphenylmethane diisocyanate, etc. be able to.

  Among these, from the viewpoint of good adhesive strength, heat resistance, and coatability, as described above, 30 to 100% by mass, particularly 50 to 100% by mass of the isocyanate compound is an aliphatic diisocyanate compound and an alicyclic type. It is preferably at least one diisocyanate compound selected from the group consisting of diisocyanate compounds. Specific examples of suitable compounds include tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate, octamethylene-1,8-diisocyanate, 2,2,4-trimethylhexane-1,6- Diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 2,4-methylcyclohexyl diisocyanate, 2,6-methylcyclohexyl diisocyanate, isophorone diisocyanate, norbornane diisocyanate, 4, 4'-methylenebis (cyclohexyl isocyanate) isomer mixture, hexahydrotoluene-2,4-diisocyanate, hexahydrotoluene-2,6-diisocyanate, hexahi Rofeniren 1,3 diisocyanate are hexahydrophthalate phenylene-1,4-diisocyanate. These diisocyanate compounds may be used alone or in combination of two or more.

(Polyol compound)
As a polyol compound which is one of the constituent components of the urethane resin, the number of hydroxyl groups contained in the molecule is preferably 2 to 6 because the urethane resin to be produced does not become a highly crosslinked product, In view of the solubility, the number of hydroxyl groups contained in the molecule is more preferably 2 to 3. Specifically, polyether polyol, polyester polyol, polycarbonate polyol, and polycaprolactone polyol are preferable as the polyol compound. These polyol compounds may be used alone or in combination of two or more. From the viewpoints of heat resistance, adhesiveness, weather resistance, hydrolysis resistance and the like, polycarbonate polyols and poly It is preferred to use caprolactone polyol.

  Examples of the polyether polyol include a polyether polyol compound obtained by reaction of a compound having two or more active hydrogen-containing groups in the molecule with an alkylene oxide, and a modified polymer polyol or urethane modified product of the polyether polyol compound. Examples include polyether polyols and polyether ester copolymer polyols.

  The compounds having two or more active hydrogen-containing groups in the molecule include water, ethylene glycol, propylene glycol, butanediol, glycerin, trimethylolpropane, hexanetriol, triethanolamine, diglycerin, pentaerythritol, tritriol. Examples thereof include polyol compounds such as glycol and glycerin having one or more hydroxyl groups in the molecule such as methylolpropane and hexanetriol, and these may be used alone or in admixture of two or more.

  Moreover, as said alkylene oxide, cyclic ether compounds, such as ethylene oxide, propylene oxide, tetrahydrofuran, are mentioned, These may be used individually or may be used in mixture of 2 or more types.

  Examples of the polyester polyol include a polyester polyol obtained by a condensation reaction between a polyhydric alcohol and a polybasic acid. Here, as the polyhydric alcohol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexane Diol, 3,3′-dimethylol heptane, 1,4-cyclohexanedimethanol, neopentyl glycol, 3,3-bis (hydroxymethyl) heptane, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, etc. These may be used alone or in combination of two or more. Examples of the polybasic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, orthophthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. These may be used alone or in combination of two or more.

  Examples of the polycarbonate polyol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1, 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 3-methyl-1,5-pentanediol 2-ethyl-4-butyl-1,3-propanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer acid diol, bisphenol A Ethylene oxide and propylene oxide adducts, Polycarbonate polyols obtained by phosgenation of one or more low molecular polyols such as bis (β-hydroxyethyl) benzene, xylylene glycol, glycerin, trimethylolpropane and pentaerythritol, or ethylene carbonate, diethyl carbonate, and diphenyl carbonate The polycarbonate polyol obtained by the transesterification method by the above etc. can be mentioned. Among these low molecular polyols, low molecular polyols having a linear alkyl chain are more preferable from the viewpoint of adhesiveness and heat resistance of the urethane urea resin finally obtained, and a low molecular polyol having an alkyl group in the side chain. Polycarbonate polyols synthesized from molecular polyols tend to have poor adhesive properties.

  Moreover, it is preferable to introduce | transduce functional groups, such as a piperidine structure, a hindered phenol structure, a triazine structure, or a benzotriazole structure, into the terminal of a urethane resin. Examples of the compound that modifies the end imparting this functionality include 1,2,2,6,6-pentamethyl-4-hydroxypiperidine having a piperidine structure, 1,2,2,6,6-pentamethyl-4-amino. Piperidine, 2,2,6,6-tetramethyl-4-hydroxypiperidine, 2,2,6,6-tetramethyl-4-aminopiperidine, 1,2,2,6,6-pentamethyl-4-aminomethyl Examples include piperidine, 1,2,2,6,6-pentamethyl-4-aminobutylpiperidine and the like. Other examples of the compound that modifies the terminal include amines such as methylamine, ethylamine, propylamine, isopropylamine, normal butylamine, tert-butylamine, pentylamine, and hexylamine.

  As a method for synthesizing the urethane resin, a so-called one-shot method or a prepolymer method can be employed. The amount ratio of the isocyanate compound, polyol compound, chain extender, and terminal-modifying compound used in the synthesis may be determined as appropriate, but the heat resistance, adhesive strength, photochromic properties (color density) of the resulting adhesive urethane resin From the viewpoint of balance such as fading speed, weather resistance, etc., the following ratio is preferable. That is, the total number of moles of hydroxyl groups contained in the polyol compound is n1, the total number of isocyanate groups contained in the isocyanate compound is n2, and the total number of groups capable of reacting with the isocyanate group contained in the chain extender is n3. N1: n2 where n4 is the total number of moles of a group capable of reacting with an isocyanate group (specifically, an amino group, a hydroxyl group, a mercapto group, and / or a carboxyl group, etc.) contained in the compound that modifies the terminal. : N3: n4 = 0.30-0.89 / 1 / 0.10-0.69 / 0.01-0.20, particularly n1: n2: n3: n4 = 0.40-0. It is preferable that the quantity ratio is 83/1 / 0.15 to 0.58 / 0.02 to 0.15, and n1: n2: n3: n4 = 0.55 to 0.78 / 1 / 0.20. ~ 0.43 / 0.02-0.1 It is most preferred to become ratio. Here, said n1-n4 can be calculated | required as a product of the use mole number of the compound used as each component, and the number of each group which exists in this compound 1 molecule.

  In the production of the urethane resin, since the isocyanate compound, the polyol compound, and the chain extender react with each other or with each other, the resulting urethane resin is obtained as a mixture having a certain molecular weight distribution. Therefore, it is difficult to specify the function of the obtained urethane resin.

(Preferable urethane resin)
Moreover, in order to improve the adhesion (adhesion) strength of an optical article (laminated body) described later, the urethane resin is a urethane bond of a urethane-urea resin having a urethane bond and a urea bond in the molecular chain, or / And a resin having a bridged structure obtained by reacting the urea bond with a polyisocyanate compound. The urethane-urea resin may be a compound having two or more amino groups in the molecule as a chain extender.

  And as a polyisocyanate compound made to react with a urea bond, in addition to the above-mentioned isocyanate compound, 1,3,5-tris (6-isocyanatohexyl) burette, (2,4,6-trioxtriazine-1, 3,5 (2H, 4H, 6H) triyl) tris (hexamethylene) isocyanate, 1-methylbenzene-2,4,6-triyltriisocyanate, 4,4 ′, 4 ′ ′-methylidynetris (isocyanatobenzene ), Methylsilanetriyltrisisocyanate, 2,6-diisocyanatocaproic acid 2-isocyanatoethyl, 2,6-bis [(2-isocyanatophenyl) methyl] phenylisocyanate, tris (3-methyl-6- Isocyanatobenzoyl) methane, tris (4-methyl-3-isocyanatobenzoyl) ) Three isocyanate groups in the molecule such as methane, tris (3-isocyanatophenyl) methane, tris (3-methyl-4-isocyanatobenzoyl) methane, tris (4-methyl-2-isocyanatobenzoyl) methane The compound which has can be mentioned. Moreover, the isocyanurate compound which has three isocyanate groups can be mentioned. Furthermore, compounds having four isocyanate groups in the molecule such as tetraisocyanatosilane and [methylenebis (2,1-phenylene)] bisisocyanate can be exemplified.

  Among these, suitable polyisocyanate compounds include compounds having an isocyanate group bonded to a secondary carbon. Specifically, isomer mixture of 4,4′-methylenebis (cyclohexyl isocyanate), cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, hexahydrotoluene-2, 4-diisocyanate, hexahydrotoluene-2,6-diisocyanate, hexahydrophenylene-1,3-diisocyanate, hexahydrophenylene-1,4-diisocyanate, and trimers of these isocyanate compounds and isophorone diisocyanate (isocyanurate compounds) ) And the like.

  As urethane-urea resin which has a bridge structure, it is preferable that the quantity of a polyisocyanate compound becomes the range of 5-20 mass parts with respect to 100 mass parts of urethane resins.

In addition, the physical properties of the functional sheet of the present invention, the viewpoint of processing stability when producing an optical article by bending or injection molding using the obtained functional sheet, and the adhesive viewpoint of these functional sheets, Furthermore, in the case of forming a hard coat layer on the surface of these functional sheets or optical articles, from the viewpoint of workability when applying or curing the hard coat liquid, as a suitable physical property of the urethane resin, The softening point is preferably 80 ° C. or higher and 150 ° C. or lower. This softening point is a value measured under the following conditions using a thermomechanical measurement device (Seiko Instruments, TMA120C).
[Measurement Conditions] Temperature rising rate: 10 ° C./min, measurement temperature range: 30 to 200 ° C., probe: needle-inserted probe with a tip diameter of 0.5 mm.

  By using a urethane resin (linear urethane resin or urethane-urea resin having a bridge structure) having a softening point of 80 ° C. or higher and 150 ° C. or lower for the adhesive layer, the surface of the functional sheet or optical article is hardened. In the case of forming a coat layer, in the case of carrying out a thermal bending process, in the case of carrying out injection molding to obtain an optical article, it exhibits excellent characteristics. And when using such a urethane resin, the method of this invention exhibits the outstanding effect.

(Photochromic compound)
As a photochromic compound used as a constituent component of the photochromic adhesive layer, known photochromic compounds such as a chromene compound, a fulgimide compound, a spirooxazine compound, and a spiropyran compound can be used without any limitation. These may be used alone or in combination of two or more.

  Examples of the fulgimide compound, spirooxazine compound, spiropyran compound and chromene compound described in JP-A-2-28154, JP-A-62-2288830, WO94 / 22850, WO96 / 14596, etc. Can be mentioned.

  Among these photochromic compounds, 1 is a chromene compound having an indeno (2,1-f) naphtho (2,1-b) pyran skeleton from the viewpoint of photochromic properties such as color density, initial coloring, durability, and fading speed. It is more preferable to use more than one type. Further, among these chromene compounds, compounds having a molecular weight of 540 or more are preferable because they are particularly excellent in color density and fading speed.

  The blending amount of the photochromic compound in the present invention is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the urethane resin from the viewpoint of photochromic properties.

  When the blending amount is too small, sufficient color density and durability tend not to be obtained. When the blending amount is too large, although depending on the type of photochromic compound, the photochromic compound is difficult to dissolve, and the composition In addition to the tendency to decrease the uniformity, the adhesive force (adhesion) also tends to decrease. In order to maintain sufficient adhesion to an optical substrate such as a polymer sheet while maintaining photochromic properties such as color density and durability, the amount of photochromic compound added is 0.5 to 100 parts by mass of urethane resin. It is more preferable to set it to 10 to 10 weight part, especially 1 to 7 mass parts.

  Hereinafter, the manufacturing method of the functional sheet (henceforth "photochromic sheet") which has the photochromic characteristic of this invention using each said component is demonstrated.

(Method for producing photochromic sheet)
In the method for producing a photochromic sheet of the present invention, a photochromic sheet is formed by interposing an adhesive layer containing a urethane resin and a photochromic compound between a pair of optical sheets or optical films laminated with a protective film.

(Adhesive layer that is a single layer (first adhesive layer))
When the photochromic adhesive layer is a single adhesive layer (hereinafter sometimes referred to as a first adhesive layer), after the photochromic adhesive layer is formed, it may be bonded to an optical film or optical sheet, or urethane. A resin and a photochromic compound may be mixed, applied onto an optical film or sheet, and directly formed into a sheet. Above all, when using a urethane-urea resin having a bridge structure, the first adhesion in which a urethane-urea resin before crosslinking, a photochromic compound, a polyisocyanate compound blended as necessary, an additive, and an organic solvent are mixed. It is preferable to form the adhesive layer in a sheet form by preparing a layer coating solution, applying the coating solution on the first or second optical film or sheet, and then drying. Or after apply | coating the said coating liquid for 1st contact bonding layers on another base material, it may be made to dry and the formed sheet may be peeled, and an adhesive layer may be formed in a sheet form.

  In this first adhesive layer coating solution, additives that are blended as necessary are known additives, surfactants, antioxidants, radical scavengers, UV stabilizers, UV absorbers, mold release agents. , Coloring agents, antistatic agents, fluorescent dyes, dyes, pigments, fragrances, plasticizers, and the like. These additives are preferably in the range of 0.001 to 20 parts by mass with respect to 100 parts by mass of the urethane resin. In addition, when using urethane-urea resin which has a bridge structure, this value is considered as 100 mass parts of urethane-urea resin before bridge | crosslinking. If these additives are used excessively, the adhesiveness of the photochromic adhesive layer to the polycarbonate sheet is lowered. Therefore, the amount added is preferably 7 parts by mass or less, more preferably 3 parts by mass or less, and most preferably 1 part by mass. It is as follows.

  Examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, t-butanol, 2-butanol, 2,2,2-trifluoroethanol; ethylene glycol monomethyl ether, Ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol Polyhydric alcohol derivatives such as n-butyl ether and ethylene glycol dimethyl ether; diacetone alcohol; methyl ethyl ketone, diethyl Tones, ketones such as n-propyl methyl ketone, methyl isobutyl ketone, diisopropyl ketone, n-butyl methyl ketone; toluene; hexane; heptane; acetates such as ethyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate Dimethylformamide (DMF); dimethyl sulfoxide (DMSO); tetrahydrofuran (THF); cyclohexanone; chloroform; dichloromethane and combinations thereof.

  When the coating liquid for the first adhesive layer as described above is applied on the polycarbonate sheet and then dried, the obtained sheets may be joined by the method described in detail below. In addition, when applied to a substrate other than the polycarbonate sheet, the substrate and the first adhesive layer are peeled off, and the obtained first adhesive layer is interposed between the polycarbonate sheets to be described in detail below. Can be joined together.

  As a method for applying the coating solution for the first adhesive layer, a known method may be adopted, and known methods such as a spin coating method, a spray coating method, a dip coating method, a dip-spin coating method, and a dry laminating method may be used. Used without any restrictions. Above all, it is desirable to use roll polycarbonate from the viewpoint of production efficiency, so it can be applied to roll sheets such as knife coaters, die coaters, gravure coaters, reverse roll coaters, bar coaters as coating machines. It is preferable to use a general coating machine. Among them, knife coaters and die coaters having a relatively wide allowable range of coating solution viscosity are preferably used.

(Multi-layer adhesive layer)
Moreover, when making a photochromic contact bonding layer into multiple layers, it is preferable to set it as the 3 layer structure which consists of a 2nd contact bonding layer / a 1st contact bonding layer / a 2nd contact bonding layer. In this case, the second adhesive layer is in contact with the two polycarbonate sheets. And adhesiveness can be improved more by mix | blending a photochromic compound with a 1st contact bonding layer.

  The first adhesive layer preferably has the same configuration as the single-layer adhesive layer. That is, the first adhesive layer has a softening point of 80 ° C. or higher and 150 ° C. or lower, and uses the urethane-urea resin having the bridge structure. In addition, a polyisocyanate compound, a photochromic compound, and blended as necessary. It is preferable to form from the coating liquid for 1st contact bonding layers which mixed the additive and the organic solvent.

  On the other hand, the second adhesive layer is not particularly limited, but it is preferable to use a urethane-urea resin having a softening point of 100 ° C. or higher and 200 ° C. or lower. The second adhesive layer may contain a photochromic compound, but it is preferable that only the first adhesive layer contains a photochromic compound in order to exhibit better adhesiveness.

  When forming an adhesive layer having such a three-layer structure, the second adhesive layer / first adhesive layer / second adhesive layer can be formed by coextrusion, but may be formed by the following method. preferable. First, a 1st contact bonding layer apply | coats the said coating liquid for 1st contact bonding layers on base materials other than a polycarbonate sheet, and shape | molds according to the said method.

  The second adhesive layer is prepared by preparing a coating solution for the second adhesive layer containing a urethane resin, an additive that is blended as necessary, and an organic solvent, and applying the coating liquid onto the polycarbonate sheet, followed by drying, thereby the second adhesive layer. A layer is formed on the polycarbonate sheet. In addition, the thing similar to what was demonstrated with the coating liquid for 1st adhesion | attachment can be used for the additive and organic solvent which are contained in the coating liquid for 2nd contact bonding layers. The second adhesive layer can be produced on a substrate other than the polycarbonate sheet, like the first adhesive layer, but is preferably produced directly on the polycarbonate sheet in order to improve the adhesiveness.

  Then, the polycarbonate sheet having the second adhesive layer and the base material having the first adhesive layer are pressure-bonded using a heated laminating roll or the like so that the second adhesive layer and the first adhesive layer are joined. . Next, the first adhesive layer that appears after the substrate is peeled off and the polycarbonate sheet having the second adhesive layer are joined by the method of the present invention so that the first adhesive layer and the second adhesive layer are joined. What is necessary is just to crimp.

(Photochromic sheet after-treatment)
The photochromic sheet of the present invention obtained by the above-described method can be used for secondary processing or the like as it is, but the state can be stabilized and used by the following method. Specifically, it is preferable to deaerate the sheet just joined at a temperature of 20 ° C. or higher and 70 ° C. or lower for 4 hours or longer under normal pressure or reduced pressure. Furthermore, it is preferable to leave this standing laminate at a temperature of 60 ° C. to 130 ° C. for 30 minutes to 3 hours (hereinafter referred to as heat treatment). In addition, when a polyisocyanate compound is blended (when a crosslinked urethane-urea resin is used for the adhesive layer), it may be humidified at a temperature of room temperature to 100 ° C. and a humidity of 30 to 100% RH. preferable.

Furthermore, after the humidification treatment, excess moisture present in the laminate can be removed by standing at 40 to 130 ° C. under normal pressure or under vacuum.
Next, the functional layer having polarization characteristics will be described.

(Functional layer with polarization characteristics)
In the functional sheet of the present invention, the functional layer having a polarizing property is not particularly limited as long as it has a polarizing property, but a layer containing a polyvinyl alcohol resin and a dichroic dye (hereinafter also referred to as “polarizing layer”). It is preferable that

  The polarizing layer of the present invention may be a single layer or may be formed from a plurality of layers. In the case of a single layer, a layer containing the polyvinyl alcohol resin and the dichroic dye may be used. In the case of a plurality of layers, the second layer may be laminated on both surfaces of the first layer containing the polyvinyl alcohol resin and the dichroic dye.

  In addition, the thickness of the polarizing layer in the obtained functional sheet is not particularly limited, but in the case of a single layer, it is preferably 10 to 500 μm. Moreover, when it is set as the structure of 2nd layer / 1st layer / 2nd layer, it is preferable that a 1st layer is 10-500 micrometers, and a 2nd layer is 2-40 micrometers. preferable.

  The polarizing layer of the present invention is preferably a uniaxially stretched resin film having a low softening point that forms a functional layer such as a polyvinyl alcohol film impregnated with an iodine compound (or dichroic dye) as a polarizer. Used. Such a polarizing material is generally used in an amount of about 0.1 to 5 parts by mass per 100 parts by mass of a resin having a low softening point. The method for producing the functional sheet having the polarizing property of the present invention (hereinafter also referred to as “polarizing sheet”) using the polarizing layer is not particularly limited, but the iodine compound ( Alternatively, it is preferably a polarizing sheet in which an optical sheet such as a polycarbonate sheet or an optical film is bonded to both surfaces of a polarizing film that is dyed with a dichroic dye and dried. As said 2nd layer (adhesion layer) used when producing a polarizing sheet, it is preferable to use the 2 liquid type thermosetting polyurethane resin which consists of a hardening | curing agent containing a polyurethane prepolymer and a polyol.

  Next, a method for laminating the protective film on the functional sheet of the present invention will be described.

(Lamination of protective film)
The method of laminating the protective film used in the present invention on the optical sheet or the optical film surface is not particularly limited as long as it is a laminating method that finally forms the functional sheet of the present invention. From the viewpoint of preventing scratches on the surface of the sheet or optical film, it is preferable that a protective film is stuck on at least one surface of the optical sheet or optical film before the functional sheet is produced.

(Functional sheet processing)
(Die cutting)
The functional sheet of the present invention may be used after being cut into a desired shape. The timing for performing the die cutting process may be before or after the thermal bending process described later.

  Blades such as Thomson blades, pinnacle blades, engraving blades, and etching blades are used in the die cutting process of the present invention, but it is preferable to use Thomson blades from the viewpoint of processing stability and economy. Examples of the shape of the Thomson blade include a double blade, a single blade, a double blade, a triple blade, a double blade, and the blade angle of the blade edge is preferably in the range of 25 to 60 °.

  The thickness of the blade is preferably 0.3 to 2.0 mm, and the material is preferably all steel having a Shore hardness of 30 to 90. As for the Shore hardness, it is also possible to adjust the sharpness by increasing only the hardness of the blade edge.

  When the functional sheet of the present invention is punched with a Thomson blade, it is more preferable to use a blade having a blade angle of 45 ° or less in consideration of the cutting property of the protective film attached to the functional sheet. The blade is preferably 30 ° or less. If the blade angle of the Thomson blade used exceeds 60 °, the protective film will be cut off, and the protective film will extend to the end of the functional sheet to generate thread-like foreign matter, or the protective film may float. It may occur, resulting in a defect in the finally obtained plastic lens and a decrease in yield.

  Moreover, the pressure at the time of the die cutting process may be determined as appropriate depending on the material of the functional sheet to be die cut. However, the functional sheet of the present invention is subjected to a pressure of 500 to 1000 kg per sheet. It is preferable to do.

(Hot bending)
Next, before integrating with the optical substrate, the functional sheet is subjected to thermal bending to form a lens-shaped spherical shape (for two eyes) or a spherical shape (1 for use in sunglasses / goggles). It can also be processed (manufactured with a processed sheet). In addition, you may die-cut to a desired shape before performing a heat bending process. Examples of the method for thermally bending the functional sheet into a spherical shape include hot press processing, pressure processing, and vacuum suction processing.

  In the hot press process, first, a convex mold having a desired spherical shape and a concave mold are mounted on a hot press machine, and the functional sheet is pressed between the molds with a fixing jig, and the convex mold is used. And heat the concave mold. Subsequently, it can be bent into a desired spherical shape by pressing with a heated mold from both sides of the functional sheet. In the case of hot pressing, it is also possible to perform bending using only a convex mold without using a concave mold. When hot pressing is performed, not only the mold but also the entire atmosphere in which the hot pressing including the functional sheet is performed may be performed.

  The pressing process uses an apparatus having a desired spherical concave mold. The functional sheet of the present invention is fixed to the concave mold with a fixing jig, and a mold capable of injecting compressed air is placed on the lower surface side of the functional sheet, and the whole is heated with a heater. Next, compressed air is injected from the lower surface side of the functional sheet and deformed into the shape of the concave mold.

  The vacuum suction processing uses a device having a desired spherical concave mold as in the pressurization processing. The functional sheet of the present invention is installed in this concave mold, or fixed with a fixing jig, and the whole is heated with a heater. Next, the functional sheet is deformed into the shape of the concave mold by vacuum suction from the inside of the concave mold.

  Further, the functional sheet of the present invention can be deformed by using both pressure processing and vacuum suction processing.

  The functional sheet of the present invention is assumed to be capable of suppressing the formation of dents according to the shape of the object during thermal processing by controlling the size and number of foreign substances contained in the protective film. Yes.

  In these hot bending methods, it is important that the functional sheet is smooth and has little warpage. In other words, if the functional sheet is warped when it is installed at a predetermined position where the functional sheet is subjected to hot bending, it is not only fixed at the predetermined position but also the functional sheet after hot bending. There is a risk of distortion in the spherical shape. According to the method of the present invention, these defects can be suppressed.

  The temperature at the time of hot bending may be appropriately determined depending on the type of the optical sheet or optical film used in the functional sheet of the present invention, but it is preferably carried out at a temperature exceeding 120 ° C. and not exceeding 200 ° C.

  Moreover, it is preferable that the functional sheet obtained by the method of the present invention is subjected to a preheating treatment as a pretreatment for performing heat bending. When the laminate is subjected to hot bending in a state containing water or air in the atmosphere, the water or air inside the functional sheet expands, and defects such as bubbles may occur. Therefore, generation of bubbles and the like can be suppressed by performing heat bending after performing the preheating treatment. The preheating treatment may be left at a temperature of 40 ° C. to 120 ° C. for 5 minutes to 24 hours. The pressure may be normal pressure, but it is more effective to perform the preheating treatment under reduced pressure.

(Process after hot bending)
The functional sheet of the present invention or the functional sheet (processed sheet) subjected to thermal bending is peeled off the protective film, and then attached to the mold of the injection molding machine. The functional sheet or the back surface of the processed sheet (concave surface) The optical base material made of a thermoplastic resin and the functional sheet or the processed sheet are integrated by injection molding of a thermoplastic resin on the) side to form an optical article such as a plastic lens. Furthermore, in order to prevent the generation | occurrence | production of the damage | wound at the time of wear of the obtained plastic lens, it can also coat | cover and use by a hard-coat layer. Further, on the surface of the plastic lens, in addition to the hard coat layer, if necessary, an antireflection treatment such as vapor deposition of a thin film of metal oxide such as SiO2, TiO2, or ZrO2 or application of a thin film of an organic polymer, Processing such as antistatic treatment or secondary treatment can also be performed.

  The invention is illustrated by the following experimental example.

In the following experiments, measurement or evaluation of various characteristics of the optical laminate or a lens obtained by processing the optical laminate was performed by the following method.
<Peel strength of functional sheet>
After peeling off the protective film from the optical laminate produced in each Example or Comparative Example, the protective film was cut into a size of 25 × 100 mm, and this was used as a test piece as a tester (Autograph AGS-500NX, manufactured by Shimadzu Corporation). ), A tensile test was performed at a crosshead speed of 100 mm / min, and the initial peel strength between the transparent substrate (polycarbonate sheet) and the functional sheet (corresponding to the optical functional layer) in the optical laminate was measured.

Moreover, after immersing the said test piece in the boiling distilled water for 1 hour, the peeling strength (peeling strength after a boiling test) of a transparent base material and a functional sheet was measured similarly.
<Peel strength of protective film>
A test piece similar to the above was prepared without peeling off the protective film, and the initial peel strength between the protective film and the transparent substrate (polycarbonate sheet) was measured. Moreover, the heat treatment was performed by holding the test piece in an atmosphere of 150 ° C. for 30 minutes, and thereafter, peel strength (peel strength after heat treatment) was measured in the same manner as described above.
<Photochromic characteristics>
After peeling off the protective film from the optical laminate, a xenon lamp L-2480 (300W) SHL-100 manufactured by Hamamatsu Photonics Co., Ltd. was passed through an aeromass filter (manufactured by Corning) at 23 ° C. on the surface of the laminate. The color intensity was irradiated for 120 seconds at a beam intensity of 365 nm = 2.4 mW / cm ² and 245 nm = 24 μW / cm ² , and the following photochromic characteristics were measured.

1) Maximum absorption wavelength (λmax):
It is the maximum absorption wavelength after color development determined by a spectrophotometer (instant multi-channel photo director MCPD1000) manufactured by Otsuka Electronics Co., Ltd. The maximum absorption wavelength is related to the color tone at the time of color development.

2) Color density [ε (120) −ε (0)]:
Difference between absorbance ε (120) after irradiation for 120 seconds at the maximum absorption wavelength and absorbance ε (0) when not irradiated at the maximum absorption wavelength. It can be said that the higher this value, the better the photochromic properties.

3) Fading speed [t1 / 2 (seconds)]:
The time required for the absorbance at the maximum wavelength of the sample to drop to half of [ε (120) −ε (0)] when light irradiation is stopped after irradiation for 120 seconds. It can be said that the shorter this time is, the better the photochromic property is.

4) Durability (%) = [(A96 / A0) × 100]:
In order to evaluate the durability of coloring by light irradiation, the following deterioration acceleration test was conducted. That is, the obtained laminate was accelerated and deteriorated for 96 hours using a xenon weather meter X25 manufactured by Suga Test Instruments Co., Ltd. Thereafter, the color density was evaluated before and after the test, the color density (A0) before the test and the color density (A96) after the test were measured, and the value of [(A96) / A0] × 100] was determined as the residual rate. (%) And used as an index of color durability. The higher the remaining rate, the higher the durability of coloring.
<Die-cutting processability evaluation>
The obtained optical laminate was subjected to die cutting to produce 20 disk-shaped sheets having a diameter of 80 mm.
(Acquisition of non-defective products from the prevention of filamentous foreign matter)
The number of disc-like sheets with 20 or less thread-like foreign matters having a length of 2 mm or more at the end of the disc-like sheet is regarded as a non-defective product with few thread-like foreign matters, and the ratio of the good disc-like sheets is drawn by stringing. It was calculated as a non-defective product acquisition rate from the prevention of thread-like foreign matter. Evaluation was evaluated visually.
(Acquisition rate of non-defective products from floating prevention)
The number of the disk-shaped sheets in which the protective film having a width of 0.5 mm or more is not more than a quarter of the outer periphery is defined as a non-defective product in which the protective film is prevented from being lifted. The ratio of the disk-shaped sheet was calculated as a non-defective product acquisition rate from the anti-floating property. Evaluation was evaluated visually.
<Lens appearance evaluation>
The following evaluation was performed by visual observation and a digital microscope (VHX-2000, manufactured by Keyence Corporation) as to whether or not a defective portion exists in the lens obtained by processing the optical laminate.

In addition, the defect which can be easily confirmed visually is a shape defect generated at the lens end, and this defect is presumed to be mainly caused by the floating of the protective film end.
(Lens molding yield)
Using a digital microscope, it was observed whether or not a defective portion was present in the obtained lens, and the ratio of non-defective lenses to 20 lenses was calculated as a lens molding yield.
(Bad 1)
The number of defective products confirmed by observing the lens surface with a digital microscope was measured.

A lens having irregularities with a diameter of 30 μm or more was defined as a defective lens, and the number of defective products per 20 sheets was shown. This defect is mainly derived from the optical impurity fine particles.
(Defect 2)
The shape defect of the lens end was visually observed, and the lens having the shape defect was regarded as a defective lens, and indicated as the number of defective products per 20 sheets. This defect is mainly caused by the fact that the end of the protective film is lifted during vacuum suction.
(Defect 3)
The adhesive residue on the lens surface was visually observed, and the one where the adhesive residue was confirmed was regarded as a defective lens, and indicated as the number of defective products per 20 sheets.
<Protective film>
Protective films 1A to 1H and 2A of two layers (low melting point layer / high melting point layer) or three layers (low melting point layer / intermediate layer / high melting point layer) prepared using various resins or resin mixtures having different melting points, respectively. ˜2R was prepared. Table 1 shows the material, tensile strength, and thickness of each protective film.

The abbreviations used in Table 1 are as follows.
LDPE: low density polyethylene HDPE: high density polyethylene PP: polypropylene LDHDmix: mixture of low density polyethylene and high density polyethylene PPLDmix: mixture of polypropylene and low density polyethylene 5ADLDPE: low density polyethylene 1ADLDPE containing 5% by weight of hydrogenated terpene resin: Low density polyethylene PVCL containing 1% by weight of hydrogenated terpene resin: Polyvinyl chloride ADLDPE-HDPEmix:
5% by weight of hydrogenated terpene resin mixture of low density polyethylene and high density polyethylene PEVAC: Polyethylene / vinyl acetate copolymer Note that low density polyethylene (LDPE) with a melting point of 130 ° C or 120 ° C is used. Has been.

  In addition, polypropylene (PP) having a melting point of 160 ° C. or 165 ° C. is used. For the above protective film, the softening start temperature and the heat of fusion area ratio (I) / (II) measured by DSC are shown in Table 2. Indicated.

Further, for the protective film, the number of optical impurity particles is measured, and the length d of the impurity particles in the film thickness direction is 2t or more, 1 to 2t, 1 to 1.8t with respect to the film thickness t. The number contained per 100 cm ² of the film in the range of 1 to 1.5 t was measured and shown in Table 3.

(Preparation of urethane resin solution for optical functional layer)
To a three-necked flask with a stirring blade, cooling tube, thermometer, and nitrogen gas inlet tube,
251.9 g of polycarbonate diol having a number average molecular weight of 800
Isophorone diisocyanate 100g
Was reacted at 110 ° C. for 7 hours under a nitrogen atmosphere to synthesize a prepolymer.

  After completion of the reaction, the reaction solution was cooled to around 30 ° C. and dissolved in 1515 g of THF, and then 23.6 g of bis- (4-aminocyclohexyl) methane, which is a chain extender, was added dropwise and reacted at 25 ° C. for 1 hour. .

  Thereafter, 7.7 g of 1,2,2,6,6-pentamethyl-4-aminopiperidine was further added dropwise and reacted at 25 ° C. for 1 hour to obtain a urethane resin solution.

In this urethane resin solution,
Photochromic compound 11.5g
40 g of an isomer mixture of 4,4′-methylenebis (cyclohexyl isocyanate)
Ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate]
(Antioxidant) 4g
DOW CORNING TORAY L-7001
(Surfactant) 0.6g
Was added and stirred and mixed at room temperature to obtain a urethane resin solution for the optical functional layer.

  In addition, as a photochromic compound, what is represented by the following formula was used.

The softening point of the urethane resin contained in the urethane resin solution for the optical function layer was 105 ° C.
(Urethane resin solution for adhesive layer)
To a three-necked flask with a stirring blade, cooling tube, thermometer, and nitrogen gas inlet tube,
220 g of polycarbonate diol with a number average molecular weight of 1000
Isophorone diisocyanate 100g
Was reacted at 110 ° C. for 7 hours under a nitrogen atmosphere to synthesize a prepolymer.

  After completion of the reaction, the reaction solution was cooled to around 30 ° C. and dissolved in 1550 g of propylene glycol monomethyl ether, and then 36 g of isophoronediamine as a chain extender was added dropwise and reacted at 25 ° C. for 1 hour.

  Thereafter, 2 g of n-butylamine was further added dropwise and reacted at 25 ° C. for 1 hour to obtain a propylene glycol monomethyl ether solution of urethane resin.

  To this urethane resin solution, 2.0 g of DOW CORNING TORAY L-7001 as a surfactant was added and stirred and mixed at room temperature to obtain a urethane resin solution for an adhesive layer.

The softening point of the urethane resin contained in the urethane resin solution for the adhesive layer was 150 ° C.
<Example 1>
(Creation of optical laminate)
A protective film 1A was laminated on one side of a 400 μm thick polycarbonate sheet to prepare a transparent substrate with a protective film.

The protective film A used here has a two-layer structure of a low melting point layer (thickness 15 μm) made of low density polyethylene having a melting point of 120 ° C. and a high melting point layer (thickness 15 μm) made of polypropylene having a melting point of 165 ° C. The total thickness t is 30 μm (see Tables 1 and 2). This protective film A contains five optical impurity particles having a size in the plane direction of 40 μm or more and a length d in the film thickness direction of 40 μm or more (1t <d <2t) per 100 cm ^2. (See Table 3).

  Moreover, about this protective film 1A, area ratio [(I) / (II)] of the heat of fusion (I) of 80-135 degreeC calculated | required by DSC and the heat of fusion (II) of 145-175 degreeC is 65 / 35.

  First, using a coater (manufactured by Tester Sangyo), the urethane resin solution for the adhesive layer is applied on the polycarbonate sheet surface (the surface on which the protective film is not laminated) of the transparent substrate at a coating speed of 0.5 m / min. The adhesive layer having a thickness of 5 μm was formed by coating and drying at a drying temperature of 110 ° C. for 3 minutes.

  In addition, the urethane resin solution for optical function layer prepared above is applied on an OPP film (stretched polypropylene film) having a thickness of 50 μm prepared separately at a coating speed of 0.3 m / min, and a drying temperature of 100 ° C. Was dried for 5 minutes to form a functional sheet (corresponding to the optical functional layer) having a thickness of 40 μm on the OPP film.

  Next, the optical functional layer is placed on the adhesive layer of the transparent substrate formed in advance, and is laminated using a laminate roll, and is composed of protective film / polycarbonate sheet / adhesive layer / functional sheet / OPP film. A laminate α was obtained.

  Next, a laminate roll obtained by peeling the OPP film from the laminate α and a polycarbonate sheet with a protective film having an adhesive layer are laminated so that the functional sheet and the adhesive layer on the polycarbonate sheet are joined. Used for pressure welding.

  The laminated sheet thus obtained was allowed to stand at 60 ° C. under vacuum (500 Pa) for 12 hours (degassing step), then heat-treated at 120 ° C. for 2 hours (heating step), and then 70 ° C. and 90%. An optical laminate having photochromic properties was obtained by performing a humidification treatment (humidification step) with RH for 20 hours, and finally leaving it at 80 ° C. under vacuum (500 Pa) for 5 hours (drying step).

  The layer structure of this optical laminated body is as follows.

Protective film / PC sheet / adhesive layer / functional sheet / adhesive layer / PC sheet / protective film (PC sheet is a polycarbonate sheet)
In the obtained optical laminate, the peel strength of the functional sheet was 200 N / 25 mm at the initial peel strength and 180 N / 25 mm after the boiling test. As for photochromic properties, the maximum absorption wavelength (λmax) was 585 nm, the color density 1.0, the fading speed 45 seconds, and the durability 93%.

Moreover, the peel strength of the protective film was an initial peel strength of 0.5 N / 25 mm, and a post-heat treatment peel strength of 0.5 N / 25 mm.
(Secondary processing of optical laminate [vacuum suction processing])
In order to mold the obtained optical laminate into a lens, the optical laminate with a protective film was die-cut using a Thomson blade (both blades, blade angle 42 °), and a disc-shaped sheet having a diameter of 80 mm was obtained. I got a copy. When the obtained disk-shaped sheet was evaluated for die-cutting workability, both the non-defective product acquisition rate from the filamentous foreign matter prevention property and the non-defective product acquisition rate from the float prevention property were 100%.

  Using the disk-shaped sheet obtained above, bending to a spherical shape was performed by vacuum suction processing (thermal bending processing). This vacuum suction processing was carried out by placing a concave mold having a diameter of 90 mm in an atmosphere at 150 ° C. and performing vacuum suction from a hole in the center of the concave mold with a vacuum pump. The processing time was about 20 minutes per sheet, and an optical laminate processed into a spherical shape was obtained by removing it from the mold. Prior to vacuum suction processing, the optical laminate was preheated at 80 ° C. for 1 hour under vacuum.

The protective films on both sides were peeled off from the processed sheet of the obtained optical laminate having a spherical shape, and then placed in a mold of an injection molding machine and heated to 100 ° C. The injection molding machine is filled with pellets of polycarbonate resin (Panlite manufactured by Teijin Chemicals Co., Ltd.) preheated at 120 ° C for 5 hours, heated and melted at 300 ° C and 60 rpm, and placed in the mold at an injection pressure of 14000 N / cm ^2. By injection, a plastic lens (optical article) integrated with a polycarbonate resin was produced.
Using the obtained optical layered body having a spherical shape, a plastic lens is manufactured in the same manner as in Example 1, and the appearance of the lens is evaluated (lens molding yield, defect 1, defect 2, defect 3). The results are shown in Table 5. The lens molding yield (lens appearance evaluation) of the obtained lens was 85%.

Table 5 shows the results of the above-mentioned die cutting processability, the peel strength of the functional sheet, the peel strength of the protective film, the photochromic characteristics, and the lens molding yield.
<Examples 2 to 12, Comparative Examples 1 to 5>
Using the protective film shown in Table 4, an optical laminate and a lens were prepared in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 5.
<Comparative Example 6>
An optical laminate and a lens are produced in the same manner as in Example 1 except that the protective film A is attached to a polycarbonate sheet using a polyethylene-based adhesive, and the same evaluation as in Example 1 is performed. Table 5 shows.
<Example 13>
An optical laminate and a lens were produced in the same manner as in Example 1 except that the protective film A was used and a polyvinyl alcohol polarizing film was used as a functional sheet corresponding to the optical functional layer. The same evaluation was performed, and the results are shown in Table 5.

  As apparent from Examples 1 to 13, when a protective film comprising a low melting point layer having a melting point of 100 to 125 ° C. and a high melting point layer having a melting point of 150 to 175 ° C. is used, the lens finally obtained The appearance was not only a defect (defect 1) related to irregularities on the lens surface, but also a shape defect (defect 2) in hot bending and a defect (defect 3) caused by adhesive residue, resulting in an extremely excellent molding yield. .

  On the other hand, as shown in Comparative Examples 1 to 5, when the melting point of the low melting point layer is outside the range of 100 to 125 ° C., when the tackifying component is blended in the low melting point layer, the melting point of the high melting point layer is 150. When the temperature is outside the range of ˜175 ° C., the lens finally obtained is excellent in the defect (defect 1) related to the unevenness of the lens surface, but the shape defect (defect 2) or adhesive residue in the heat bending process is not good. The defect (defect 3) attributed to was inferior, and the molding yield decreased.

  Furthermore, as shown in Comparative Example 6, when the protective film was affixed to the polycarbonate sheet with an adhesive, the defect 3 due to the adhesive residue was extremely bad.

Claims (9)

  A functional sheet in which a protective film for protecting the surface is laminated on at least one surface of a functional sheet having a functional layer between a pair of optical sheets or films, wherein the protective film has at least two layers or more And the first layer having a melting point of 150 ° C. or more and 175 ° C. or less, wherein at least one layer is bonded to a functional sheet having a melting point of 100 ° C. or more and less than 125 ° C. A functional sheet which is a film (second film layer) disposed on the outer layer side of the film layer.   2. The functional sheet according to claim 1, wherein 20 or less thread-like foreign matters having a length of 2 mm or more are generated at an end portion of the functional sheet after the die-cutting step to be molded into a desired shape.   The functional sheet according to claim 1, wherein the functional layer has a photochromic function and / or a polarizing function. The protective film is made of at least one or a mixture of two or more selected from polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-α-olefin copolymer and propylene-α-olefin copolymer for each layer. Laminated product,
And the thickness of this protective film is 10-150 micrometers, The functional sheet of any one of Claims 1-3.   The softening point of the said functional layer is 80 degreeC or more, The laminated body which has a photochromic function of any one of Claims 1-4. The functional layer comprises at least a layer having a photochromic function, and the layer having a photochromic function comprises a urethane-urea resin (A) and a photochromic compound (B). A functional sheet having a photochromic function according to any one of 5. The polyurethane-urea resin (A) is
(A1) at least one polyol compound selected from the group consisting of polycarbonate polyol and polycaprolactone polyol;
(A2) a diisocyanate compound having two isocyanate groups in the molecule;
(A3) an amino group-containing compound having two or more amino groups in the molecule;
(A4) a functional compound having a group capable of reacting with one or two isocyanate groups in the molecule and having a piperidine structure in the molecule;
The functional sheet having a photochromic function according to claim 6, wherein the functional sheet is a resin obtained by reaction. The layer having a photochromic function comprises a reaction product of the polyurethane-urea resin (A) and (C) a polyisocyanate compound having at least two isocyanate groups in the molecule. A functional sheet having a photochromic function. The molded object of the functional sheet using the functional sheet of any one of Claims 1-8.