JP2010085911A - Lens substrate for infrared ray absorbing spectacles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens substrate for infrared ray absorbing polarized spectacles which sufficiently shows infrared absorption performance and in which an infrared absorption function and lens color tone are not partially varied but are stable, without wasting a large quantity of an expensive infrared ray absorbent as grinding swarf when cutting a molded lens substrate for infrared ray absorbing polarized spectacles in order to obtain a required lens diopter nor causing deterioration or decomposition of the infrared absorbent due to heat during molding. <P>SOLUTION: A polarizing element 3 which is formed by coating both surfaces of a polarizing film 2 with polyurethane resin containing the infrared absorbent, with the same layer thickness and a lens substrate 1 for spectacles, which is formed of polyurethane resin not containing the infrared absorbent and has the side of a concave lens surface 1b used for grinding for diopter adjustment are integrated into the lens substrate for infrared ray absorbing polarized spectacles by insert-molding accompanying a polymerization reaction of the polyurethane material so that the polarizing element 3 is put over a convex lens surface 1a being one surface of the lens substrate 1 for eyeglasses. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an infrared-absorbing spectacle lens substrate made of polyurethane resin and a method for producing the same.

  In general, a lens base material for spectacles is manufactured by casting polymerization, and a convex lens surface is formed on the surface of one side thereof, and the back surface is formed in a concave shape or a flat shape, and a required lens as a spectacle lens. In order to adjust the frequency, the back surface is ground without grinding the surface, and a coating is applied as necessary to improve functionality.

  The lens base material for polarizing glasses is an integrated body in which a polarizing element having a polarizing film (film) is superposed on the lens base material for eyeglasses as described above, and the polarizing film stretches a resin film uniaxially. It is prepared by impregnating iodine or the like as a polarizing dye.

  To manufacture a polarizing eyeglass lens substrate by the casting polymerization method, a polarizing film preliminarily formed into a predetermined curved shape is held along the inner peripheral surface of a ring-shaped gasket that matches a lens substrate of a required diameter. A pair of molds are arranged above and below the polarizing film, and are fitted into the inner periphery of the gasket in a liquid-tight manner, and a monomer is injected into the gap (cavity) between the molds to cause a polymerization reaction, thereby polarizing elements. (Patent Document 1).

By the way, glasses are useful not only for correcting vision but also for protecting eye cells from harmful rays, and many sun glasses and light-shielding glasses contain UV absorbers that block UV transmission. UV-absorbing spectacle lenses are used.
Moreover, as a kind of harmful light beam to be controlled in the spectacle lens, not only the ultraviolet region but also the infrared region is required.

  Incidentally, among infrared rays, an electromagnetic wave having a wavelength of 780 to 1300 nm that is invisible to the eye is referred to as a near infrared ray, and an electromagnetic wave having a wavelength of 1300 to 2000 nm that is also invisible to the eye is referred to as a mid infrared ray. The penetrating power in these wavelength ranges extends to 30 mm below the skin, and particularly near infrared light passes through the cornea and reaches almost the retina, which may damage the fundus.

  Infrared burns tend not only to be exposed to intense light instantaneously, but also to accumulate damage gradually over a long period of time. There are examples.

  General infrared absorbing dyes for blocking infrared transmission, that is, dyes that absorb in the infrared region (also called infrared absorbers) include azo, aminium, anthraquinone, cyanine, and polymethine. Systems, diphenylmethane, triphenylmethane, quinone, diimonium, dithiol metal complex, squarylium, phthalocyanine, naphthalocyanine and the like are known.

  A solvent-containing coating solution is formed so as to form a coating layer with a resin composition in which such an infrared absorber is dispersed in a resin serving as a binder alone or in combination as necessary, and this is applied and dried. An infrared absorption filter in which an infrared absorption layer is formed is known (Patent Document 2).

  Some of the infrared absorbers as described above are 0 with respect to a synthetic resin base material excellent in optical properties for glasses such as polycarbonate, diethylene glycol bisallyl carbonate (CR-39), polymethyl methacrylate (PMMA), and the like. It is known that about 0.001 to 0.05% by weight is blended and formed as a spectacle lens (Patent Document 3).

JP 2001-318044 A JP-A-2005-43921 JP-A-2003-107412 (Claims 2 to 4, paragraphs 0013, 0020, 0022, 0023)

  However, in the conventional spectacle lens technology described above, in order to coat the surface of the lens with the infrared absorber, the coating layer is made as thin as possible so as not to deteriorate the optical characteristics of the original spectacle lens. In this case, the desired infrared absorption performance cannot be sufficiently ensured.

  As another means for providing a general-purpose lens with desired infrared absorption performance, an infrared absorber is dispersed in a thermoplastic resin material, and the thermoplastic resin is melted to form a lens. Although possible, optical distortion may occur in the lens, and foreign matter cannot be sufficiently filtered out of the resin, so that the manufacturing method is not suitable for high-quality spectacle lenses.

  As a thermoplastic resin for spectacles, MMA (methyl methacrylate resin) and PC (polycarbonate resin), which are excellent in transparency, are often selectively employed, but MMA is not sufficient in terms of impact resistance. In addition, when PC of a certain molecular weight is used, the impact resistance is increased, but the molding temperature is required to be 250 ° C. or higher, and at that temperature, the infrared absorber is deteriorated and decomposed. A lens having both properties cannot be obtained.

  In addition, CR-39, which is a typical resin of a casting type curable resin for plastic spectacle lenses, and a medium refractive index resin (for example, Nippon Oil & Fats: Corporex, refractive index 1.56) Allyl diglycol carbonate is included as a component and is an anaerobic thermosetting resin that cures using diisopropyl peroxydicarbonate (hereinafter abbreviated as IPP) as a catalyst, but the IPP of the catalyst used is a peroxide. In addition, it is difficult for an infrared absorber to react with such a peroxide to deteriorate and decompose to obtain a desired infrared absorption performance.

  The thiourethane resin is a well-known high refractive index resin (for example, Mitsui Chemicals: thiourethane resin MR-7, refractive index 1.67) obtained by combining isocyanate and polythiol. When an agent was blended, it reacted with sulfur-based components and catalysts to deteriorate and decompose, and a sufficient infrared control effect could not be obtained.

In addition, the lens substrate for infrared-absorbing polarized glasses has various problems in terms of its structure.
For example, as shown in FIG. 7, when a spectacle lens base material is prepared by adding an expensive functionality imparting agent such as an infrared absorber to the entire resin composition constituting the lens base material B, the required lens power is obtained. In order to obtain the lens base material, for example, most of the back surface b ′ is removed by grinding, leaving a front side portion b indicated by a one-dot chain line in the figure. In this case, most of the expensive functionality-imparting agent added is discarded as grinding waste, and there is a problem that the efficiency of using the functionality-imparting agent is poor.

  In addition, in lenses with a degree that varies in thickness in the radial direction depending on the lens power, the amount per unit area of a functional imparting agent such as an infrared absorber added to the lens substrate from the beginning depends on the thickness of the lens. In this case, there is a problem that the desired function such as infrared absorption cannot be stably performed regardless of the position of the lens. Also, since infrared absorbers usually have a color tone, even a single lens can cause a difference in the color tone depending on the partial thickness, making it possible to stably produce lenses of a certain standard. This is also not preferable from the viewpoint of obtaining high quality.

  When a resin containing a function-imparting agent such as an infrared absorber is cast and formed on both sides of the polarizing film at once by a normal polarizing lens manufacturing method, a lens base material for spectacles used for grinding for lens power adjustment is formed on one side. A thick layer to be formed is formed, and a thin layer is formed on the other side, and there is a difference in flow rate at the time of casting molding of the resin material on the front and back surfaces of the polarizing film. Twisting off the gasket, turning it over, and creating a non-uniform part of the resin density called striae, making the lens non-homogeneous and non-uniform in refractive index, causing the transmitted light to fluctuate. There is a problem that the phenomenon also occurs.

  Therefore, the first problem of the present invention is to solve the above-described problems, and when the molded lens substrate for infrared-absorbing polarized glasses cuts the lens substrate to obtain a required lens power. It does not waste a large amount of expensive infrared absorbent as grinding waste, and the infrared absorbent exhibits sufficient infrared absorption performance without causing deterioration or decomposition due to heat during molding. The color tone is to make the lens substrate for infrared-absorbing polarized glasses stable without partial variations.

  In addition, the above-described excellent infrared-absorbing spectacle lens base material is efficiently produced, and the polarizing film does not come off from the gasket, invert, or move into trouble, especially during casting, It is also a second object of the present invention to provide a manufacturing method in which non-uniformity in the density of the resin called is unlikely to occur.

  In order to solve the first problem, in the present invention, a polarizing element formed by coating both surfaces of a polarizing film with a polyurethane resin containing an infrared absorber, and a polyurethane containing no infrared absorber A lens base material for spectacles that is made of resin and is used for grinding for adjusting the lens power is integrated so that the polarizing element is superposed on one side of the lens base material for spectacles by insert molding involving a polymerization reaction of a polyurethane resin material. Thus, a lens base material for infrared-absorbing polarized glasses was obtained.

  The lens substrate for infrared-absorbing spectacles according to the present invention configured as described above is formed by covering the both surfaces of a polarizing film with a polyurethane resin in which a polarizing element contains an infrared absorber. Since the spectacle lens base material used for grinding does not contain an infrared absorber, even if the back surface of the spectacle lens base material is ground to adjust the lens power, The function of the infrared absorber of the polarizing element provided in an overlapping manner can be efficiently utilized according to the amount of the infrared absorber added without being ground and removed.

  Further, the infrared absorptive spectacle lens of the present invention is an integrated one in which the polarizing element is overlapped on one side of the spectacle lens base material by insert molding accompanied by a polymerization reaction of a polyurethane resin material. Adoption of a combination of an absorbent and a polyurethane resin composition results in deterioration of infrared absorber function and reduced visible light transmittance due to additives such as peroxide (polymerization catalyst such as benzoyl peroxide, polymerization initiator, etc.) Trends are avoided. Moreover, molding at a relatively low temperature is possible, and it is not necessary to mold at a high temperature exceeding 250 ° C. as in the prior art, so that deterioration of the function of the infrared absorber due to heating is also avoided.

That is, the polyurethane resin material is a polyurethane resin material containing, as a main component, a prepolymer obtained by reacting a polyisocyanate and a polyhydroxy compound, and containing an aromatic polyamine as a curing agent.
A polyurethane resin composition comprising such a material is a compound in which an atomic group having an isocyanate group that is easy to add is added to a bifunctional compound to form a polymer, and is a peroxide-based polymerization catalyst or polymerization initiator. In addition, there is no deterioration of the function of the infrared absorber in the cast molding and subsequent curing of the spectacle lens.

  In order to add the infrared absorbing dye to the polyurethane resin composition, the infrared absorbing dye is blended so that the average of infrared transmittance in the wavelength range of 780 to 2500 nm can be suppressed to 80% or less, preferably 30% or less. It is preferable to use a spectacle lens.

  In the invention of these infrared absorptive spectacle lenses, polyisocyanate is 4,4′-methylene-bis (cyclohexyl isocyanate) in order to be a spectacle lens excellent in transparency and impact resistance. Or an infrared-absorbing spectacle lens that is isophorone diisocyanate, and the polyhydroxy compound is preferably a polyether diol or polyester diol having an average molecular weight of 700 to 1200 or a mixture thereof, and further an aromatic polyamine is It is preferably 4,4′-methylene-bis (2-chloroaniline).

In order to obtain a more excellent impact / infrared absorbing spectacle lens, a polyurethane prepolymer having a reaction molar ratio (NCO / OH) of polyisocyanate and polyhydroxy compound of 2.5 to 4.0 and produced. It is preferable to use the above-described infrared-absorbing spectacle lens in which a polyisocyanate and a polyhydroxy compound are blended so that the NCO content is 7.0 to 14.0%.
The polarizing element is preferably a polarizing element in which both surfaces of a polarizing film are coated with the same layer thickness with a polyurethane resin material for cast molding with improved homogeneity. Of course, there is a case where the values are set individually.

  In order to manufacture an infrared-absorbing spectacle lens base material and solve the above-mentioned second problem, a spectacle lens base material used for grinding for lens power adjustment was molded with a polyurethane resin not containing an infrared-absorbing dye. Thereafter, the spectacle lens base material is inserted into the spectacle lens mold, and a polarizing film is placed on the front and back surfaces of the cavity where the lens surface of the spectacle lens base and the inner surface of the spectacle lens mold face each other. Then, a polyurethane resin material containing an infrared-absorbing dye is cast in a spectacle lens mold so as to fill the layered gap, and the polarizing element is formed by this casting. And the polarizing element and the spectacle lens base material are integrated so as to overlap each other by a polymerization reaction of a polyurethane resin material.

  Alternatively, after forming a polarizing element in which both front and back surfaces of the polarizing film are coated with a polyurethane resin material containing an infrared absorbing pigment, the polarizing element is inserted into a spectacle lens mold and the polarizing element and the lens mold A polyurethane resin material that does not contain an infrared absorber in the gap is cast-molded, and the lens base material for spectacles used for grinding for adjusting the lens power is cast into the polarizing element by polymerization reaction of the polyurethane resin material. It is also possible to employ a method for manufacturing a lens base material for infrared-absorbing polarized spectacles, which is formed by integrating the layers.

  The present invention relates to a polarizing element formed by coating a polarizing film with a polyurethane resin containing an infrared absorber, and a lens base material for spectacles formed of a polyurethane resin not containing an infrared absorber. Since the polarizing element is integrated on one side of the spectacle lens base material by insert molding with a polymerization reaction of the material, the required lens power adjustment is performed on the molded infrared absorptive polarizing spectacle lens base material. Therefore, even if the lens base material is cut, the amount of wasteful use of the expensive infrared absorbent as grinding waste is small, and the infrared absorbent exhibits excellent infrared absorption performance without causing deterioration or decomposition of the infrared absorbent. .

  In addition, the function of the infrared ray absorption functioning stably does not vary depending on the thickness of each lens portion, and the color tone due to infrared ray absorption does not vary depending on the lens thickness. Therefore, there is an advantage that it becomes a lens substrate for high-quality infrared-absorbing polarized spectacles.

  In addition, the invention relating to the method for manufacturing a lens substrate for infrared-absorbing polarized spectacles has the advantage that an infrared-absorbing polarizing spectacle lens substrate having the advantages described above can be manufactured, and a polarizing film is provided in a predetermined cavity. Inserting so that layered gaps are formed on both front and back sides, and cast polyurethane resin material containing infrared absorbing dye into the spectacle lens mold so as to fill the layered gaps. A resin layer of almost the same thickness is easily formed on the surface of the polarizing film, so that the flow rate of the urethane resin material is constant on both the front and back surfaces of the polarizing film at the time of casting, so that the polarizing film is not easily detached from the gasket and is not easily reversed. Alternatively, there is an advantage that the manufacturing method does not move to a defect and is difficult to cause non-uniformity of resin density called striae.

  Further, in the method in which a polarizing element is inserted into a spectacle lens mold and a polyurethane resin material not containing an infrared absorber is cast in the gap between the polarizing element and the lens mold, the above-described advantages are obtained. There is an advantage that a certain lens substrate for infrared-absorbing polarized spectacles can be efficiently manufactured, and further, a polarizing element in which both front and back surfaces of the film are coated with a polyurethane resin material containing an infrared-absorbing dye in the same thickness is molded. Therefore, there is an advantage that the polarizing film does not easily come off from the mold or gasket, does not easily reverse, or does not move to a defect, and the manufacturing method is less likely to cause unevenness of resin density called striae.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIGS. 1-3, embodiment of the invention which concerns on the lens base material A for infrared absorptive spectacles is the polarizing element 3 formed by coat | covering both surfaces of the polarizing film 2 with the polyurethane resin containing an infrared absorber. And a spectacle lens base 1 formed of a polyurethane resin not containing an infrared absorber and used for grinding whose power is adjusted on the concave lens surface 1b side, and a lens base for spectacles by insert molding with a polymerization reaction of the polyurethane resin material. The polarizing element 3 is integrated so as to overlap the convex lens surface 1 a on one side of the material 1.

Although the polarizing film 2 is obtained according to a well-known manufacturing method, for example, it is preferable to employ a film obtained by impregnating a film made of polyvinyl alcohol with iodine, an iodine compound, or a dye by impregnation.
When both surfaces of the polarizing film 2 are coated with the polyurethane resin composition, the polarizing film 2 is inserted in a mold with a curve in advance and insert molding is performed, or a sheet-like polyurethane resin composition is formed on both surfaces of the polarizing film 2. Articles may be laminated, and an adhesive may be interposed as required.

  The polyurethane resin composition as a constituent material of the polarizing element 3 is mainly composed of a polyurethane resin obtained by addition polymerization reaction of a prepolymer obtained by reacting a polyisocyanate and a polyhydroxy compound and an aromatic polyamine as a curing agent, A composition containing an infrared absorber can be employed.

  In order to manufacture the infrared-absorbing spectacle lens base A, first, as shown in FIGS. 2 and 3, the spectacle lens base 1 used for grinding for adjusting the lens power does not contain an infrared-absorbing dye. Molded with a polyurethane resin composition.

  In order to form such a spectacle lens substrate 1 or polarizing element 3 with a polyurethane resin, a casting method can be employed. To explain the outline of this method, in order to mold a lens, a pair of concave and convex molds are fitted in a liquid-tight manner through a gasket, and a prepolymer is placed in a cavity formed between the pair of molds. A mixture of aromatic polyamines, which are curing agents, is injected, polymerized and cured.

  In addition, when fitting a concave mold and a convex mold through a ring-shaped gasket, a polarizing film is inserted in the gasket in advance. Then, the monomer of the resin raw material is injected from the injection hole formed in the mold or gasket so as to flow along both surfaces of the polarizing film, covered with the resin, and polymerized and cured.

More specifically, the polyurethane resin material is obtained by blending, for example, a polyisocyanate and a polyhydroxy compound such that their reaction molar ratio (NCO / OH) is 2.5 to 4.0. It is preferable to prepare a polyurethane resin composition in which 0 to 14.0% of polyurethane prepolymer and aromatic polyamine are blended so that the reaction molar ratio (NCO / NH ₂ ) is 1.10 to 0.90.

  In the first embodiment according to the invention of the manufacturing method of the lens substrate for infrared-absorbing polarized spectacles, first, the spectacle lens substrate 1 used for grinding for lens power adjustment is molded with a polyurethane resin containing no infrared-absorbing dye. Thereafter, the molded spectacle lens substrate 1 is inserted into a polarizing spectacle lens mold.

  The eyeglass lens base material 1 comprises a polyurethane resin composition made of a disk-shaped lower mold 5 formed with a meniscus-shaped recess 4 shown in the cross-sectional shape of FIG. 2, and an upper mold 6 that forms the upper surface of the convex lens. Are cast into a cavity for forming a meniscus lens substrate in a mold constituted by combining the above.

  Next, the eyeglass lens substrate 1 taken out after molding as shown in FIG. 3 is then inserted into a mold having the gasket 7 and the upper mold 9 for insert molding shown in FIGS. In that case, the spectacle lens substrate 1 can be used as a lower mold (a lower mold may be provided separately). Then, the polarizing film 2 is inserted into a layered cavity where the lens surface 1a and the inner surface 9b of the upper mold 9 which is a spectacle lens mold are opposed so that a layered gap is formed on both the front and back surfaces.

That is, as shown in FIGS. 4 and 5, the mold for insert molding is inserted into the lower part of the inner periphery of the ring-shaped gasket 7 with the pre-manufactured eyeglass lens base material 1 being aligned without any gaps. A polarizing film 2 is inserted above the material 1 with an interval of, for example, about 1 mm. At this time, the polarizing film 2 preformed so as to be along the upper surface of the spectacle lens substrate 1 is held by the annular protrusion 7 a extending in the circumferential direction at the center of the inner peripheral surface of the ring-shaped gasket 7.
The eyeglass lens base material 1 is formed by cutting a step-shaped cut around the lens base material 1 and aligning it with the lower inner periphery of the gasket 7.

Further, above the polarizing film 2, for example, a disk-shaped upper mold 9 having a spherical crown surface on the inside with an interval of about 1 mm is fitted and held on the inner peripheral upper portion of the gasket 7 in a liquid-tight manner. .
In order to fix the spectacle lens substrate 1 and the upper mold 9 to the gasket 7, it is preferable to elastically press the clip 7 with a clip indicated by a chain line from above and below, and appropriately insert a protective material. It is also preferable to protect the parts.

  Using the insert molding die configured as described above, a mixture of a prepolymer and a curing agent is injected from the gate 7b into a layered space formed above the lens base material 1 for spectacles. In this way, the surface of the polarizing film 2 was covered with the polyurethane resin composition by insert molding accompanied by a polymerization reaction of the polyurethane resin material, and disposed with a gap of, for example, 1 to 2 mm on the spectacle lens substrate 1. The gap in contact with the polarizing film is filled with a polyurethane resin composition, and the polarizing element 3 is integrated with the lens base material 1 for spectacles to produce an infrared-absorbing spectacle lens base material shown in FIG.

  The lens substrate for infrared-absorbing spectacles thus obtained does not contain an infrared absorber or the like in the lens substrate 1, so that even if the lens substrate 1 is ground to adjust the lens power, it absorbs infrared rays. The agent is not scraped off as grinding waste, and the infrared absorption function is evenly exerted without being affected even if the lens thickness differs between the central portion and the peripheral portion. Therefore, the function of the added infrared absorber is stable and the lens base material for spectacles can be efficiently added.

  As shown in FIG. 6, as a second embodiment of the invention relating to the method of manufacturing a lens substrate for infrared-absorbing polarized glasses, both the front and back surfaces of the polarizing film 2 are coated with a polyurethane resin material containing an infrared-absorbing dye. After the polarizing element 3 is molded, the polarizing element 3 is inserted into a spectacle lens mold having a gasket 7 and a lower mold 8 to substitute for the upper mold, and infrared rays are absorbed in the gap between the polarizing element 3 and the lower mold 8. A polyurethane resin material not containing an agent is cast-molded, and the lens base material 1 for spectacles used for grinding for lens power adjustment is cast on the polarizing element by a polymerization reaction of the polyurethane resin material. This is a method that integrates the two.

  The shaping of the polarizing element 3 will be described with reference to FIG. A lower mold prepared in advance is attached to the gasket 7. Next, the polarizing film 2 is inserted with an interval of, for example, 1 mm above and below. Next, the upper mold 9 is attached to the gasket 7. The polarizing film 2 is hold | maintained at the cyclic | annular convex part 7a extended in a gasket inner peripheral direction.

  Next, a mixture of the prepolymer and the aromatic polyamine is injected from the gate 7b. In this way, the polarizing element 3 is formed by covering both the front and back surfaces of the polarizing film 2 with the polyurethane resin composition layer having the same thickness by insert molding involving a polymerization reaction of the polyurethane resin material.

  Next, as shown in FIG. 6, the polarizing element 3 is inserted into a spectacle lens mold having a gasket 7 and a lower mold 8. At this time, the polarizing element 3 is substituted for the upper mold, and a clip (not shown) is used to elastically press and fix the polarizing element 3 and the lower mold 8 from above and below appropriately through a protective material.

  Thereafter, a polyurethane resin material that does not contain an infrared absorber is cast from a gate 7b into a cavity formed between the polarizing element 3 and the lower mold 8, and the lens power is adjusted by this casting. The spectacle lens base material 1 used for grinding is integrated so as to overlap the polarizing element 3, and the infrared light spectacle lens base material shown in FIG. 1 is manufactured.

The materials used for manufacturing the infrared-absorbing spectacle lens substrate used in the above-described embodiment will be described in detail below.
The polyisocyanate used for the polyurethane resin material is preferably alicyclic diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate) or isophorone diisocyanate.
Polyisocyanates other than those mentioned above include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, hydrogenated XDl, norbornane diisocyanate and the like, but when these are used, the pot life of the resulting urethane resin is not sufficiently increased.

The polyhydroxy compound used in the present invention is a polyether diol or polyester diol having an average molecular weight of 700 to 1200 and a mixture thereof.
As the polyether diol, polyoxytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran and other polyether diols can be used. As the polyester diol, various known polyesters can be used, and 1,4-butanediol adipate and 1,6-hexanediol adipate are preferable.

  The viscosity of the prepolymer obtained by reacting with the diisocyanate is lower for prepolymers from polyether diols, which is advantageous for casting operations. Therefore, polyether diol is particularly preferable as the polyhydroxy compound used in the present invention.

  In order to improve hardness and chemical resistance, an aliphatic polyol having a molecular weight of 300 or less may be used in combination. Examples of the aliphatic polyol include diols such as ethylene glycol, diethylene glycol, propylene glycol, and 1,4-butanediol, and triols such as trimethylolethane and trimethylolpropane.

  A typical example of an aromatic polyamine preferably used in the present invention is an aromatic diamine, and 4,4'-methylene-bis (2-chloroaniline) is particularly preferable because of its long molding pot life. However, other well-known aromatic polyamines can also be used. When the aromatic polyamine is used and the pot life is short, it is necessary to take care such as quickly performing the molding operation.

  Examples of the known aromatic diamines include aromatic monocyclic diamines such as 2,4-diamino-3,5-diethyltoluene and 2,6-diamino-3,5-diethyltoluene, and aromatic polyamines. The cyclic diamines 4,4'methylene-bis (2,6-diisopropylaniline), 4,4'methylene-bis (2,6-dimethylaniline), 4,4'methylene-bis (2-ethyl-6) -Methylaniline), 4,4'methylene-bis (2,6-diethylaniline), 4,4'methylene-bis (2-isopropyl-6-methylaniline), 4,4'methylene-bis (3-chloro -2,6-diethylaniline).

  In the present invention, when a prepolymer obtained by reacting a polyisocyanate and a polyhydroxy compound is produced, the reaction molar ratio (NCO / OH) is preferably 2.5 to 4.0. The NCO content is preferably 7.0 to 14.0%. If the reaction molar ratio and the NCO content are smaller than these ranges, the prepolymer viscosity becomes too high, making it difficult to perform the casting operation of the polarizing element, and the hardness of the lens substrate for polarizing glasses is also not preferable. Moreover, when larger than the said range, hardened | cured material property will deteriorate and it is not preferable.

The mixing molar ratio (NCO / NH ₂ ) between the prepolymer of this invention and the aromatic polyamine is 1.10 to 0.90, and well-known curing conditions can be employed.

As the infrared absorber, an infrared absorber that absorbs infrared rays over a wavelength range of 780 to 2500 nm may be selected, and known infrared absorbing dyes can be used. For example, the following are preferably used. .
(1) An infrared absorber comprising N, N, N ′, N′-tetrakis (p-substituted phenyl) -p-phenylenediamines, benzidines and their aluminum salts and diimonium salts.
(2) N, N, N ′, N′-tetraarylquinone dimonium salts.
(3) Bis- (p-dialkylaminophenyl) [N, N-bis (p-dialkylaminophenyl) p-aminophenyl] aminium salt.

Moreover, as an ultraviolet absorber which can be used as needed, the following are mentioned, for example.
(1) 2-hydroxy-4-n-octoxybenzophenone
(2) 4-Dodecyloxy-2-hydroxybenzophenone
(3) 2-2'-hydroxy-4-methoxybenzophenone

  When these ultraviolet absorbers are used, all ultraviolet rays of UV-A (315 to 400 nm) having a long wavelength, UV-B (280 to 315 nm) having a short wavelength, and UV-C (100 to 280 nm) having a shorter wavelength are used. Is preferably absorbed.

For example, in order to extinguish the blue flame of the welding light, it is necessary to absorb a wavelength of 380 to 450 nm, and when a polarizing film and an infrared absorber are used, they are absorbed without adding a dye, but a polarizing film is not used. In some cases, yellow dyes, orange dyes, red dyes and mixtures thereof that absorb blue in the resin are used.
In order to make the eyeglass lens have a brown color tone, a yellow dye, an orange dye, a red dye, or a mixture thereof is used.

A water-soluble dye is selected when dyeing on a polarizing film, and an oil-soluble dye is suitable when dyeing a urethane resin.
There are direct dyes, acid dyes, basic dyes, sulfur dyes, disperse dyes, oil-soluble dyes and the like as dye types, but it is desirable to use dyes with excellent fastness properties.

  The addition amount of the infrared absorber is usually 0.05 to 10 parts by weight with respect to 100 parts by weight of the material constituting the lens (impact urethane), and is preferably 0 when used for applications other than the light shielding protector. A range of 0.1 to 1.0 parts by weight is suitable. In the case of a light shielding protector, it may be added according to the required infrared absorption performance.

  The addition amount of the ultraviolet absorber is 0.01 to 4 parts by weight, preferably 0.1 to 4.0 parts by weight, more preferably 0, with respect to 100 parts by weight of the material constituting the lens (impact urethane). A range of 2 to 0.5 parts by weight is suitable.

The spectacle lens of the present invention transmits at least visible light having a wavelength in the range of 380 to 780 nm, the transmittance is in the range of 1% to 75%, and is preferably in the range of 10% to 40% except for the light shielding protector.
The ultraviolet wavelength (100 nm to 380 nm) is less than 0.1%, preferably less than 0.02, and it is more suitable not to transmit. In addition, the durability of the infrared absorbent when used outdoors is improved by adding the ultraviolet absorbent.
As for the infrared wavelength (780 nm to 2500 nm), the average transmittance is 80% or less, preferably 30% or less, and the average transmittance can be adjusted to be high according to the demands of consumers such as emphasizing fashionability. . However, this is not the case for the light-shielding protective equipment used in welding work and the like because it is based on the specified standards.

When used for anything other than light-shielding protective equipment, the color tone is adjusted to suit the taste in consideration of fashionability, but the average light transmittance (A%) in the wavelength range of 380 to 550 nm and the average light transmittance in the wavelength range of 550 to 780 nm. It is preferable to adjust the color tone by adding an infrared absorber to the color tone of the lens having a ratio (B%) of A / B ≦ 0.3.
The color tone of the spectacle lens can correspond to various preferences, but since there are many infrared absorbers that exhibit a green color, there are some limitations, and it is only necessary to select in consideration of infrared absorption performance and fashionability. .

  The eyeglass lens can be hard-coated. In this method, a lens is immersed in a solution containing a silicon compound or the like to form a reinforced film to improve surface hardness. Further, it is possible to further improve the performance by applying antifogging treatment, antireflection treatment, chemical resistance treatment, antistatic treatment, mirror treatment, water repellent treatment and the like.

  The spectacle lens manufactured in this way suppresses the transmission of harmful rays of infrared rays and ultraviolet rays, so it is suitable for use in places with extremely strong sunlight. Eye damage due to light rays can be prevented.

  In addition, it is obliged to wear light-shielding protective equipment for work that generates ultraviolet rays, intense visible light, and infrared rays that are harmful to the eyes, such as welding work. Although the standard of use is defined in JIS T 8141 depending on the working state, a usable light-shielding lens can be produced by adjusting the amount of the infrared absorber or coloring material added.

The eyeglass lens according to the preferred adjustment example in the present invention can reliably prevent eye damage (the following five types) caused by harmful rays.
(1) Damage to cornea and conjunctiva due to UV-B, C
(2) Damage to the lens by UV-A
(3) Photochemical damage to the retina by blue light
(4) Damage to the cornea and lens due to visible and near infrared rays
(5) Damage to the cornea and lens due to near- and mid-infrared rays

Next, the infrared-absorbing spectacle lens substrate obtained as described above was examined for deterioration in infrared-absorbing property.
In the following Examples and Comparative Examples, all “parts” and “%” are “parts by weight” and “% by weight” unless otherwise specified.

[Prepolymer production]
In a 500 ml separable flask equipped with a thermometer, stirrer, and nitrogen seal tube, 200 parts of polyoxytetramethylene glycol (Hodogaya Chemical Industry: PTG-1000N) with an average molecular weight of 1014 is taken and heated while stirring in a nitrogen stream. And dehydrated under reduced pressure of 100 to 110 ° C./3 to 5 mmHg for 1 hour. After dehydration, 170 parts of 4,4′-methylene-bis (cyclohexyl isocyanate) (manufactured by Sumitomo Bayer Urethane: Desmodur W) was added and reacted at 120 to 130 ° C. for 2 hours to produce a prepolymer. The obtained prepolymer was a colorless transparent liquid, and had an NCO content of 9.9%, a viscosity of 8600 mPa · s / 30 ° C., and 750 mPa · s / 60 ° C.

[Production example of eyeglass lens substrate]
100 parts by weight of the resulting prepolymer was heated to 70 ° C., and then mixed and degassed with 31.4 parts by weight of 4,4′-methylene-bis (2-chloroaniline) melted at 120 ° C. This mixture was poured into a mold preheated at 100 ° C. and cured by heating at 100 ° C. for 24 hours to produce a spectacle lens substrate. The mixing molar ratio (NCO / NH ₂ ) at this time was 1.0.

[Production example of polarizing element]
A polarizing film made of polyvinyl alcohol having a red color tone (copper 30) was previously inserted into a molding die for a polarizing element, and then insert molding was performed in which a molding material was injected. At that time, in the molding material (mixture) for the lens base material for spectacles described above, except that 0.13 parts by weight of diimonium-based compound (manufactured by Nippon Kayaku Co., Ltd .: IRG-022) as an infrared absorber was added. A polarizing element was produced in the same manner. A near-infrared spectroscopy chart (thickness of about 2.0 mm) of the obtained polarizing element is shown in FIG.

  The average of the infrared transmittance in the wavelength range of 780 to 2500 nm is calculated from the result of FIG. 8 to be 3.93% (the average of the infrared transmittance in the wavelength range of 780 to 1700 nm is 2.27%). It can be seen that there was no deterioration of the infrared absorber, and a polarizing element having the expected excellent infrared absorption performance was obtained.

[Comparative Production Example 1 of Polarizing Element]
Infrared absorber diimonium compound (manufactured by Nippon Kayaku Co., Ltd .: IRG-022) with respect to 100 parts by weight of high refractive index resin (Mitsui Chemicals: thiourethane resin MR-7, refractive index 1.67) .13 parts by weight was added, and a polarizing film made of polyvinyl alcohol having a red color tone (Copa-15) was sandwiched and cast to produce a polarizing element. A near-infrared spectroscopic chart of the obtained polarizing element (lens thickness of about 2.4 mm) is shown in FIG.

  From the result of FIG. 9, when the average of infrared transmittance in the wavelength range of 780 to 2500 nm is examined, it is 47.70% (when the average of infrared transmittance in the wavelength range of 780 to 1700 nm is examined, 70.26%). In addition, it can be seen that the desired infrared absorption performance is not obtained because the infrared absorber has deteriorated by reacting with the sulfur-based component.

[Comparative Production Example 2 of Polarizing Element]
0.13 parts by weight of an infrared absorbent diimonium-based compound (manufactured by Nippon Kayaku Co., Ltd .: IRG-022) is added to 100 parts by weight of allyl diglycol carbonate (CR-39) as a base resin. A polarizing element was manufactured by sandwiching and casting a polarizing film made of polyvinyl alcohol having a color tone (copper 30). A near-infrared spectroscopic chart of the obtained polarizing element (lens thickness of about 2.0 mm) is shown in FIG.

  From the result of FIG. 10, when the average of the infrared transmittance in the wavelength range of 780 to 2500 nm is examined, it is 58.20% (the average of the infrared transmittance in the wavelength range of 780 to 1700 nm is 81.47%). In other words, the infrared absorbing agent reacts with the peroxide catalyst IPP, deteriorates and decomposes, and the desired infrared absorbing performance is not obtained.

  As described above, a polarizing element formed by adding an infrared absorber to a polyurethane resin obtained by addition polymerization reaction of a polyisocyanate and a polyhydroxy compound and an aromatic polyamine exhibits excellent infrared absorption performance. It can be seen that even when this is integrally molded so as to be integrated with the lens substrate, the infrared absorber does not deteriorate or decompose.

Sectional drawing of the lens base material for infrared absorptive spectacles which shows an Example Sectional drawing which shows the shaping | molding die of the lens base material for spectacles Cross-sectional view of eyeglass lens substrate Plan view showing gasket of lens substrate for infrared absorbing glasses Sectional drawing which shows the manufacturing method of 1st embodiment, and shows the gasket and mold of the VV line cross section of FIG. Sectional drawing which shows the manufacturing method of 2nd embodiment, and shows a gasket and a mold Sectional drawing of the lens base material for infrared absorptive spectacles which shows a prior art example Near-infrared spectroscopic chart of manufacturing example of polarizing element Near-infrared spectroscopic chart of Comparative Example 1 of polarizing element Near-infrared spectroscopic chart of Comparative Example 2 of polarizing element

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Eyeglass lens base material 1a Convex lens surface 1b Concave lens surface 2 Polarizing film 3 Polarizing element 4 Meniscus-shaped recessed part 5 Lower mold 6 Upper mold 7 Gasket 8 Lower mold 9 Upper mold A Infrared-absorbing spectacle lens base B Conventional example Infrared-absorbing eyeglass lens substrate

Claims (7)

  A polarizing element formed by covering both surfaces of a polarizing film with a polyurethane resin containing an infrared absorber, and a lens base material for spectacles that is formed of a polyurethane resin that does not contain an infrared absorber and is used for grinding for lens power adjustment And an infrared-absorbing polarizing spectacle lens substrate obtained by integrating the polarizing element on one side of the spectacle lens base material by insert molding with a polymerization reaction of a polyurethane resin material.   2. The lens group for infrared-absorbing polarizing glasses according to claim 1, wherein the polyurethane resin material is a polyurethane resin material containing, as a main component, a prepolymer obtained by reacting a polyisocyanate and a polyhydroxy compound and containing an aromatic polyamine as a curing agent. Wood.   The polyurethane resin material has a reaction molar ratio of polyisocyanate and polyhydroxy compound (NCO / OH) of 2.5 to 4.0, and the resulting polyurethane prepolymer has an NCO content of 7.0 to 14.0%. The lens substrate for infrared-absorbing polarized glasses according to claim 2, which is a polyurethane resin material in which polyisocyanate and a polyhydroxy compound are blended.   The lens substrate for infrared absorbing polarizing glasses according to any one of claims 1 to 3, wherein the polarizing film is a polarizing film obtained by impregnating a stretched film made of polyvinyl alcohol resin with iodine or an iodine compound.   The infrared light-absorbing polarizing spectacle lens substrate according to any one of claims 1 to 4, wherein the polarizing element is a polarizing element in which both surfaces of a polarizing film are coated with polyurethane resin so as to have the same layer thickness.   After molding a spectacle lens base material used for grinding for lens power adjustment with a polyurethane resin not containing an infrared absorbing dye, the spectacle lens base material is inserted into a spectacle lens mold and the spectacles are used. Insert a polarizing film into the cavity where the lens surface of the lens base material and the inner surface of the spectacle lens mold face each other so that a layered gap is formed on both front and back surfaces, and then a polyurethane resin material containing an infrared absorbing dye Casting is performed in a spectacle lens mold so as to fill the layered gap, and a polarizing element is formed by this casting, and the polarizing element and the spectacle lens base material are overlapped by a polymerization reaction of a polyurethane resin material. The manufacturing method of the lens base material for infrared absorptive polarized spectacles which consists of integrating like.   After forming a polarizing element whose front and back surfaces of the polarizing film are coated with a polyurethane resin material containing an infrared absorbing dye, the polarizing element is inserted into a spectacle lens mold and inserted into the gap between the polarizing element and the lens mold. A polyurethane resin material not containing an infrared absorber was cast-molded, and the lens base material for spectacles used for grinding for lens power adjustment was superimposed on the polarizing element by a polymerization reaction of the polyurethane resin material by this cast molding. The manufacturing method of the lens base material for infrared absorptive polarizing glasses which consists of integrating in this way.

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