MX2008008224A - Method of spin coating. - Google Patents

Abstract

A method of spin coating in which a coating liquid having a high viscosity is ejected at a relatively high rate to spin-coat a base surface while diminishing or preventing air bubble inclusion in the coating film being formed. The spin coating method comprises ejecting a coating fluid from a nozzle tip to drop the coating fluid on a surface of a base which is rotating and thereby form an even coating film on the base surface, and is characterized in that the distance between the nozzle tip and the base surface at the time of coating fluid ejection is 2.5 mm or shorter.

Description

METHOD OF COVERING BY TURNOVER Field of the Invention The present invention relates to a spin coating method for the formation of a uniform coating film on a surface of a substrate. In more detail, the present invention relates to a method of spin coating whereby, when a photochromic layer is formed on a lens substrate of the eyeglasses having a primer layer on the surface, the incorporation of bubbles into the layer Photochromic can be prevented. BACKGROUND OF THE INVENTION Photochromic goggles are glasses whose lenses are rapidly colored in an exterior irradiated with a light containing UV rays such as sunlight to function as sun glasses and which fade in an irradiated interior without light to function like ordinary transparent glasses, and the demands with it grow larger in recent years. As a method for producing a plastic lens having photochromic characteristics, a method is known in which a photochromic compound is impregnated on a surface of a lens that has no photochromic characteristic (impregnation method), a method in which a Photochromic compound is dissolved in a monomer and the solution obtained is polymerized to directly obtain a lens photochromic (in mass method), and a method in which a layer having photochromic characteristics (hereinafter also referred to as a photochromic coating layer) is formed on a surface of a plastic lens using a coating liquid that it contains a photochromic compound (hereinafter also referred to as a photochromic coating agent or simply as a coating liquid) (coating method). Among these methods, the coating method has an advantage, compared to the other two methods, that it can easily impart photochromic characteristics, in principle, to any lens substrate. For example, in the impregnation method, it is required to use a soft substrate in which the photochromic compound diffuses easily as a lens substrate, and in the mass method, it is required to use a special monomer composition to achieve excellent photochromic characteristics . On the other hand, in the coating method, there is no such restriction to the substrates. In the coating method, in general, the spin coating method is adopted in which a coating liquid is dripped onto a surface of a lens substrate while the substrate is rotated along the central axis, the liquid The coating is developed by the centrifugal force during rotation to form a uniform coating film.

In the spin coating method, it is always necessary to perform a stable feed of the photochromic coating agent in a minimum required amount to prevent variation in the thickness of the coating film between the products as well as to suppress the production cost. In the formation of a photochromic coating layer on a surface of a lens substrate, although the lens substrate can be coated directly with the coating liquid, to improve the adhesion between the lens substrate of various types, and the coating layer Photochromic, it is preferable that the photochromic coating layer be formed after the formation of a primer layer on the surface of the lens substrate. In this case, while the photochromic coating layer is dissolving the primer layer, adhesion is acquired between the lens substrate and the photochromic coating layer. However, when an uncured photochromic coating agent and the primer layer are in contact with one another for a long period of time, the primer layer is dissolved so that the adhesion between the lens substrate and the coating layer Photochromic is reduced and the uniformity of the primer layer also deteriorates. To prevent such inconveniences, it is required that the drip and spreading step of the photochromic coating agent be completed within a predetermined period of time. For this reason, it is desired that Dripping operations of approximately 1 g of the coating liquid upon cure is completed within 10 to 120 sec per lens substrate. That is, a predetermined amount of coating liquid is required to drip within a predetermined period of time in view of industrial production. Therefore, manual drip using an eyedropper, etc. it should not be adopted in industrial production. To drip a predetermined amount of coating liquid within a predetermined period of time, a method is generally adopted wherein the coating liquid inside a barrel is discharged from a nozzle attached to the nozzle of the barrel for a predetermined period of time using air (nitrogen, etc.) with a constant pressure (refer to Document 1 of the Patent). However, if the discharge was performed continuously for a large number of lens substrates, the coating liquid retained in the nozzle of the nozzle will ever drain. To prevent draining, it is effective to install a check valve on the nozzle and reduce the diameter of the nozzle. [Patent Document 1] Japanese Patent Pending Publication No. 013873/2005 Description of the Invention Problems to be Solved with the Invention To drip a predetermined amount of the Nozzle coating liquid having a smaller diameter within a predetermined period of time, the discharge velocity (linear velocity) of the coating liquid is inevitably increased with respect to the case using a nozzle having a larger diameter. However, it was found that bubbles are often generated in the coating film formed if the linear velocity is increased. As a reason for this phenomenon, although not theoretically restricted, the following possibility can be considered: When a drop discharged from the nozzle is falling, the portion of the nozzle is affected by the influence of the air pressure around it and sucks air to form bubbles, and bubbles trapped in the coating liquid remain even after the drop reaches the surface of the substrate. If the wettability of the coating liquid to the surface of the substrate is high, even when the bubbles have been trapped in the coating liquid, since the coating liquid immediately develops on the surface of the substrate, the bubbles are defoamed flowing from the liquid of coating in many cases. However, for the primer layer and the photochromic coating agent, such defoaming can not be expected to occur due to poor wettability. In addition, the photochromic coating layer above mentioned is relatively thick and typically formed to have a thickness of approximately 40 μ? . To form a coating film having this thickness, a coating liquid having a relatively high viscosity is used as the photochromic coating agent. If the coating liquid has a very high viscosity, the aforementioned bubble aspiration occurs more frequently during discharge. Such bubbles have a diameter of approximately 10 μ? T ?, and the presence thereof can be confirmed with the naked eye. Therefore, particularly for spectacle lenses, the commercial value is significantly reduced if the bubbles are incorporated in the photochromic layer. For this reason, a technique is required to reduce or prevent the incorporation of bubbles in the coating film formed by spin coating on a surface of a substrate with a coating liquid having a high viscosity at a relatively high discharge rate. Means for solving the problems The means for solving the aforementioned problems that the present invention provides are as follows: (1) a spin coating method comprising discharging a coating liquid from the nozzle of a nozzle and apply drip on a surface of a substrate that rotates to form a uniform coating film on the surface of the substrate, where the distance between the nozzle nozzle and the surface of the substrate during the discharge of the coating liquid is 2.5 mm or less; (2) the spin coating method according to item (1), wherein the linear velocity during the dripping of the coating liquid is 1 cm / sec or more; (3) the spin coating method according to items (1) or (2), wherein the viscosity of the coating liquid is in the range of 50 cP to 500 cP at 25 ° C; (4) the spin coating method according to any of the items (1) to (3), wherein the substrate is a spectacle lens having a primer layer on the surface and the coating liquid comprises a composition curable containing a photochromic compound; and (5) a method for producing a substrate with a cured film, which comprises curing a coating film on a substrate obtained by the spin coating method according to any of the aforementioned items (1) to (4). * Effects of the invention According to the present invention, a spin coating method is provided by which a uniform coating film can be formed on a surface of a substratum. In particular, when a photochromic coating agent having a relatively high viscosity is discharged at a high velocity onto a lens substrate of the glasses having a primer layer on the surface to form a photochromic coating layer, the incorporation of bubbles in the photochromic layer it can be prevented. Brief Description of the Drawings [Figure 1] Figure 1 is a sectional view, showing a representative embodiment of the coating method according to the present invention. Description of the Symbols 10 Nozzle 11 Barrel 20 Coating Liquid 30 Substrate 31 Primer Coating 40 Support Device Best Mode for Carrying Out the Invention Hereinafter, the embodiments of the present invention are specifically explained with reference to the drawings. In the spin coating method, as shown in Figure 1, the coating liquid 20 is discharged from the nozzle 10 of the nozzle 10 and the coating liquid is applied by dripping onto the surface of the substrate 30 which is rotating.

The substrate 30 is supported on a rotating support device 40. The nozzle 10 is connected to the barrel 11 filled with the coating liquid 20. A structure is provided in which air pressure (nitrogen, etc.) is applied to the barrel 11. to discharge a predetermined amount of the coating liquid 20 at a constant speed. In this structure, therefore, a predetermined amount of the coating liquid 20 can be applied by dripping onto the surface of the substrate within a predetermined period of time by controlling the air pressure in intervals. A check valve can be installed in the part connecting the barrel 11 and the nozzle 10 to prevent runoff of the liquid. The nozzle 10 has no particular limitation on its shape and can be any of so-called pointed nozzle, curved nozzle, narrow nozzle and grooved nozzle. In particular, the curved nozzle and the grooved nozzle are preferable. From the viewpoint of preventing runoff of the coating liquid 20, the internal diameter of the nozzle 10 is preferably 3.0 mm or less, preferably 2.0 mm or less and especially preferred in the range of 1.6 mm to 0.5 mm. If the internal diameter is too large, runoff is likely to occur even in a state where no air pressure is applied after the completion of the discharge. Meanwhile, if the The internal diameter is too small, when a predetermined amount of the coating liquid is discharged within a predetermined period of time, the discharge pressure of the coating liquid becomes higher and therefore the linear velocity at the time of discharging is increases, to thereby increase the possibility of incorporation of bubbles in the coating film. In the present invention, the distance between the nozzle nozzle 10 and the surface of the substrate 30 during discharge of the coating liquid is 2.5 mm or less, and preferably 2.0 mm or less, and is preferably 0.3 mm or more and further preferable 0.5 mm or more. Therefore, when the coating liquid is applied by dripping, the distance between the nozzle nozzle 10 and the surface of the substrate 30 is preferably set in the range of 1.5 to 0.5 mm, and especially in the range of 1.2 mm. to 0.8 mm. If the distance between the nozzle nozzle 10 and the surface of the substrate 30 exceeds 2.5 mm, the coating liquid traps bubbles during dripping, probably causing the incorporation of bubbles in the coating film. If the nozzle nozzle 10 and the surface of the substrate 30 are very close to each other, the nozzle nozzle may touch and damage the surface of the substrate or may touch the surface of the coating film, thereby deteriorating the uniformity of the coating film. On the other hand, during the dripping of the coating liquid, the Rotations of the substrate 30 are preferably maintained relatively low (200 RPM or less, preferably at approximately 100 RPM). If the revolution of the substrate 30 is too high, the droplets are likely to trap bubbles when they come in contact with the surface of the substrate 30, possibly causing a lack of product. To control the distance between the nozzle nozzle 10 and the surface of the substrate 30, either one or both of the feed devices (including the barrel 11 and the nozzle 10) of the coating liquid and support device 40 are held with a mechanism capable of moving up and down. On the other hand, a means for automatically measuring the distance between the nozzle nozzle 10 and the surface of the substrate 30 can be installed. In addition, the nozzle 10 can be held so as to be movable in the radial direction of the substrate 30. By releasing the coating liquid 20 from the nozzle 10 of the nozzle 10 to apply it drip onto the rotating substrate under the aforementioned conditions, the coating liquid applied by dripping onto the surface of the substrate 30 will develop uniformly on the surface of the substrate 30 by the centrifugal force caused by the rotation of the substrate 30, and a coating film having a uniform thickness on the surface of the substrate is obtained. substrate 30. If the wettability between the coating liquid 20 and the surface of the substrate 30 it is poor, the coating liquid 20 is sometimes preserved in the vicinity of the pieces where it was applied by dripping. In this case, the coating liquid can be developed by rotating the substrate 30 while it comes into contact with a brush or a soft film (PET film, etc.) with the coating liquid 20. In addition, after the termination the application By dripping the coating liquid or after the development of the coating liquid, it is preferable that the revolutions of the substrate 30 are increased to make the thickness of the coating film uniform. The revolutions at this time, which depend on the viscosity of the coating liquid and other conditions, are typically 300 RPM or more, and preferably approximately 600 RPM. The high speed of rotation of the substrate 30 sometimes causes vibration thereof. In such a situation, if the distance between the nozzle nozzle 10 and the surface of the substrate 30 is maintained at 0.7 mm or less, the nozzle of the nozzle may touch and damage the surface of the substrate or may touch the surface of the coating film, thereby deteriorating the uniformity of the coating film. Therefore, before the high speed of rotation of the substrate, the distance between the nozzle of the nozzle 10 and the surface of the substrate 30 is preferably increased to 0.7 mm or more. As mentioned above, one or both of the feeding devices (including the barrel 11 and the nozzle 10) of the liquid of The coating and the support device 40 are supported with a mechanism capable of moving up and down, thereby allowing the distance between the nozzle nozzle and the surface of the substrate to be adjusted as appropriate. In addition, the nozzle 10 should be held in such a manner that it is movable towards the radial direction of the substrate 30, and prior to the high rotational speed of the substrate, the nozzle 10 can be switched from above the substrate 30 so that the nozzle of the nozzle can move away to the position where it can not touch the surface of the substrate. As mentioned above, in general, as the rate of discharge (linear velocity) of the coating liquid increases, the possibility of incorporation of bubbles in the coating film increases. However, by adopting the above-mentioned conditions of the present invention, although the rate of discharge of the coating liquid increases, the incorporation of bubbles in the coating film can be prevented. Therefore, the methods of the present invention are preferably adopted particularly under the condition that the linear velocity of the coating liquid at the time of the drip application is 1 cm / sec or more, more preferably 5 cm / sec or more, and especially 10 to 70 cm / sec. It is not necessary to say, according to the present invention, that the incorporation of bubbles can also be prevented under the condition that the linear velocity of the coating liquid at the moment the drip application is less than 1 cm / sec. Here, the rate of discharge of the coating liquid refers to the rate of discharge of the coating liquid at the outlet position of the nozzle and can be calculated from the internal diameter of the nozzle, from the discharge amount for a coating and from the time of discharge for a coating.

The discharge velocity equation used in the present invention can be expressed as follows: [Equation 1] Discharge velocity (cm / sec) = discharge amount (cm3) / [(inner diameter of the nozzle (mm) / 2) 2 X p X discharge time (sec)] The discharge velocity can be adjusted as appropriate by changing the internal diameter of the nozzle 10, the air pressure applied to barrel 11 or similar. For example, if the internal diameter of the nozzle is reduced, the discharge velocity is increased in case the air pressure is the same. If the air pressure is increased, the discharge velocity is increased in case the internal diameter of the nozzle is the same. On the other hand, as mentioned above, in general, as the viscosity of the coating liquid increases, the possibility of incorporation of bubbles in the coating film increases. However, by adopting the conditions of the present invention, although the viscosity of the coating liquid increases, the incorporation of bubbles in the coating film can be prevented. Therefore, the methods of the present invention can preferably be adopted particularly in spin coating with a coating liquid having a viscosity of 50 cP at 500 cP, more preferably from 60 cP to 400 cP and especially preferably from 70 cP to 300 cP at 25 ° C. Here, the viscosity of the coating liquid was measured at 25 ° C using a Cannon-Fenske viscometer. The measurement was made in accordance with JISK2283, and the viscosity of the coating liquid was calculated from the kinetic viscosity obtained and the specific gravity of the sample determined in advance using the equation, Viscosity (cP) = kinetic gravity (cSt) X Specific gravity . The viscosity of the coating liquid can be adjusted by selecting the type of composition and the index of the composition used in the preparation of the coating liquid.

To a composition having a low viscosity is added further, the viscosity of the coating liquid decreases. As described above, the coating method of the present invention can preferably be employed particularly in spin coating with a coating liquid having a relatively high viscosity at a high discharge rate.

Therefore, for example, as a method of producing a photochromic eyeglass lens in which a thick photochromic layer is required to be formed, the coating method of the present invention is especially preferable. Hereinafter, the coating method of the present invention is more specifically explained for the case of the application for producing a photochromic eyeglass lens as an example.

In this case, a disc-shaped substrate made of glass or resin, which is normally used as a lens, can conveniently be used as the substrate 30. In general, a plastic spectacle lens has a curved surface and its convex surface it often has a complicated curved shape due to the advancement of optical design in recent years. However, in the present invention, such a spectacle lens can be used as the substrate 30 without any problem. In addition, the adhesion to the substrate 30 can be further improved by modifying its surface which will be coated using a known public method before coating it with a coating liquid. The method for modification is not particularly limited, and there may be mentioned, for example, modification by discharge treatment, such as treatment of plasma discharge and corona treatment, modification by glazing of the surface with a glazing agent or the like and modification by immersion in a solution such as an alkaline solution.

In addition, to particularly improve the adhesion of the photochromic layer, the surface of the substrate 30 is preferably provided with a primer layer 31. The primer layer 31 can be formed from a variety of primer resins used in this type of applications. If a photochromic agent (vi) described below is used, preferably a urethane-based primer resin is particularly used from the point of view of adhesion for this coating agent. Such a urethane-based primer resin is described in detail in WO 2004/078476. As the photochromic coating agent, there may be several coating agents used in this technical field. Specifically, there can be mentioned, for example, (i) a photochromic coating agent comprising a photochromic compound dissolved in a urethane oligomer (refer to WO 1998/37115), (ii) a photochromic coating agent comprising a photochromic compound dissolved in a polymerizable monomer composition which is a combination of a monofunctional, a bifunctional, and a multifunctional monomer of polymerizable radical (refer to U.S. Patent Publication No. 5914174) (iii) a photochromic coating agent comprising a compound photochromic dissolved in a composition of monomer composed of a combination of only two or more kinds of bifunctional (meta) acrylic monomers (see reference WO 2001/02449), (iv) a photochromic coating agent comprising N-alkoxymethyl (meth) acrylamide, a catalyst ( preferably an acid catalyst) and a photochromic compound (refer to WO 2000/36047), (v) a photochromic coating agent comprising a polymerizable radical monomer having a silanol group or a group that generates a silanol group by hydrolysis, an amine compound and a photochromic compound in specific amounts respectively (document brochure WO 2003/011967), (vi) photochromic coating agent comprising a component of a polymerizable radical monomer, a surfactant with a silicone base or a base fluorine and a photochromic compound (refer to WO 2004/078476), and the like. Among these, in particular, the photochromic coating agent (vi) is preferably used from the point of view of adhesion to the aforementioned urethane-based primer resin. However, when the surface of a lens substrate having the urethane-based primer layer is coated with the photochromic coating agent (vi), the The photochromic coating agent excessively dissolves the primer layer during a long period of contact between a photochromic coating agent and the primer layer, in such a way as to deteriorate the uniformity of the primer layer. To prevent such inconvenience, the drip and scatter operation of the coating solution is required to be completed within a constant period. For this reason, in industrial mass production, about 1 g of the coating liquid is drip applied within 5 sec to 30 sec per lens substrate. The discharge nozzle having a small diameter is used to prevent runoff of the liquid, and to drip a predetermined amount of the nozzle coating liquid having such a small diameter within a predetermined period of time, the discharge velocity ( linear velocity) of the coating liquid is inevitably increased compared to the case using a nozzle having a larger diameter, and consequently, the bubbles are sometimes incorporated in the coating film. Even in this case, however, the incorporation of bubbles in the coating film can be prevented by adopting the coating method of the present invention. Subsequently, a substrate with a cured film can be obtained by curing the coating film formed on the substrate by an appropriate medium. A means to cure the film of Coating is varied depending on the composition of the coating film. For example, in the case of the photochromic coating agent (vi) described above, the curing is preferably carried out with the combination of curing and ultraviolet thermosetting. [Industrial Applicability] The present invention provides a spin coating method with which a uniform bubble-free coating film can be formed on a surface of a substrate. Particularly when rotatingly coating a spectacle lens substrate having a primer layer on the surface with a photochromic coating agent having a relatively high viscosity at a high discharge rate to form a photochromic coating layer, the incorporation of bubbles in the photochromic coating layer it can be efficiently prevented. Accordingly, the method of the present invention can contribute to improving the productivity of a photochromic eyeglass lens. (Examples) Hereinafter, the present invention will be explained with reference to the examples and comparative examples, but the present invention is not restricted to these examples. The lens substrates and primer ingredients used in the present examples are shown below.

[Lens substrate] • CR (plastic lens made of allylic resin, refractive index = 1.50) • MRA (resin plastic lens with thiourethane base, refractive index = 1.60) • MRB (resin plastic lens with base of thiourethane, refractive index = 1.67) • TE (resin plastic lens with thioepoxy base, refractive index = 1.71) • SPL (plastic lens of methacrylic resin, refractive index = 1.54) • SE (resin lens) methacrylic + vinyl resin; refractive index = 1.60) [Primer ingredient] • Moisture cure primer, "Takeseal PFR402TP-4", manufactured by Takebayashi Chemical Industry Co., Ltd. • Moisture curing primer, "Takeseal PFR4", manufactured by Takebayashi Chemical Industry Co., Ltd • Moisture cure primer, "Urethane Primer 06", manufactured by ALPS Chemicals Mfg. Co., Ltd. • Moisture cure primer, "Takenate M-402P", manufactured by Mitsui Takeda Chemicals Inc. • Moisture cure primer, "Barnock DM652", manufactured by Dainippon Ink and Chemicals, Incorporated [M ore om of polymerizable radical] • TMPT: trimethylolpropane trimethacrylate • UG6: urethane hexacrylate oligomer (Shin-Nakamura Chemical Co., Ltd .: U-6HA) • EB6A: polyester hexacrylate oligomer (Daicel-UCB Company Ltd .: EB-1830) • GMA: glycidyl methacrylate • BPE: 2,2-bis (4-methacryloyloxypentaethoxyphenyl) propane • 9GDA: polyethylene glycol diacrylate (average molecular weight: 532) • BPE-Oligo: 2,2-bis (4-acryloyloxy polyethylene glycol phenyl) propane having a molecular weight of 776 (Photochromic compound) • PC1 (Formula 1) «PC2 (Formula 2) • PC3 (Formula 3) [Polymerization initiator] • CGI1800: mixture of 1-hydroxyzothiohexyl phenyl ketone and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide (weight ratio 3: 1) • CGI1870: mixture of 1-Hydroxycyanohexyl phenyl ketone and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide (weight ratio: 3: 7) [Stabilizer] • LS765: bis (1, 2,2,6 sebacate) , 6-pentamethyl-4-piperidyl) [Leveling agent] • SiL1: silicone-based surfactant "L7001" manufactured by Dow-Toray Corning Co., Ltd. • SiL2: silicone-based surfactant "FZ2104" manufactured by Dow -Toray Corning Co., Ltd. [Silane coupling agent] • TSL: y-methacryloyloxypropyltrimethoxysilane (Example 1) CR (plastic lens of allylic resin; refractive index = 1.50) was used as a lens substrate. This lens substrate was completely degreased with acetone. A mixed liquid was prepared by mixing 50 parts by weight of each moisture cure primer "Takeseal PFR402TP-4" manufactured by Takebayashi Chemical Industry Co., Ltd. as a primer and ethyl acetate. To the resulting mixed liquid, 0.03 parts by weight of a leveling agent "FZ2104" manufactured by Dow-Toray Corning Co., Ltd. was subsequently added, and the resulting solution was completely stirred under a nitrogen atmosphere until it became uniform to obtain the composition (a). The surface of the CR was rotationally coated with this composition using a 1H-DX2 rotating applicator manufactured by MIKASA Co., Ltd. The lens was subjected to curing at room temperature for 15 minutes to prepare a lens substrate having a layer of primer. Subsequently, the surface of the aforementioned lens substrate having the primer layer was rotationally coated with about 1 g of a photochromic polymerizable composition. The conditions of the coating per turn at this time were as follows. The revolutions of the lens substrate were maintained at 100 RPM for approximately 25 sec. During this period, the photochromic polymerizable composition, while discharging for 13 sec, was pushed and expanded towards the outer side of the lens substrate using a PET film.

(STAGE 1). Subsequently, the revolutions were increased from 100 RPM to 600 RPM for 6 sec (STAGE 2), maintained at 600 RPM for 10 sec (STAGE 3), and then decreased from 600 RPM to 0 RPM for 2 sec (STAGE 4). The distance between the lens substrate and the nozzle of the dispenser was initially adjusted to 1 mm, and after finishing discharge of the photochromic polymerizable composition, the nozzle of the dispenser was moved from the center of the lens substrate to the exterior of the lens substrate while that the distance was maintained at 1 mm. This movement of the nozzle of the dispenser was performed in the course of STEP 1. Here, as a nozzle of the dispenser, a curved nozzle manufactured by SAN-EI TECH Ltd. having an internal diameter of 0.84 mm was used, through which approximately 1 g of the coating liquid was discharged onto the surface of the aforementioned lens substrate having the primer layer for 13 sec. The discharge rate of the coating liquid at this time was 14 cm / sec. The composition (I) shown below was used as the photochromic polymerizable composition. A mixture was prepared by mixing polymerizable radicals monomers, 2,2-bis (4-methacryloyloxypentaethoxyphenyl) propane / polyethylene glycol diacrylate (average molecular weight; 532) / trimethylolpropane trimethacrylate / hexaperylate polyester oligomer (Daicel-UCB Company, Ltd .: EB -1830) / glycidyl methacrylate in the range of 40/15/25/10/10 parts by weight, respectively. To 100 parts of this polymerizable radical monomer mixture was added 2.0 parts by weight of a photochromic compound (PC1) having a structure represented by the following formula, [Formula 4] 0. 6 parts by weight of a photochromic compound (PC2) having a structure represented by the following formula, [Formula 5] 0. 4 parts by weight of a photochromic compound (PC3) having a structure represented by the following formula. [Formula 6] After the resulting mixture was completely mixed, 0.5 parts by weight of a polymerization initiator, CGI 1800 [mixture of 1-hydroxycyclohexyl phenyl ketone and bis (2,6-dimethoxybenzoyl) oxide -2.4.4 were added here. -trimethylpentylphosphine; (Weight ratio 3: 1)], 5 parts by weight of a stabilizer, sebacate bis (1, 2,2,6, 6-pentamethyl-4-piperidyl), 7 parts by weight of a silane coupling agent, and methacryloyloxypropyltrimethoxysilane and 0.1 parts by weight of a leveling agent (silicon-based surfactant), "L-7001" manufactured by Dow-Toray Corning Co., Ltd., and the mixture was thoroughly mixed. The resulting photochromic polymerizable composition had a viscosity of 130 cP at 25 ° C. The surface of this coated lens was irradiated using a metal halide lamp whose output at 405 nm was adjusted to be 130 mW / cm2 on the surface of the lens to cure the coating film for 3 min. In a nitrogen gas atmosphere, and then further subjected to a heat treatment in a thermostat at 120 ° C to obtain a photochromic cured thin film. The thickness of the thin film obtained can be adjusted depending on the condition of the coating by rotation. In the present invention, the thickness of the cured photochromic thin film was adjusted to be 40 ± 1 μ? T ?. The appearance of the lens substrate having that prepared photochromic cured film was evaluated as follows: the lens substrate having the cured film was irradiated with light from a high pressure mercury lamp, the projection surface was displayed on white paper, the projection surface at the center of the lens (where the photochromic composition was first dispensed) was observed. The evaluation criteria are described below. Good: No defect was observed. Poor: Defects such as bubbles were observed. The appearance of the lens substrate prepared by the aforementioned method was evaluated as "good". In addition, to evaluate the photochromic characteristics of the lens substrate having the photochromic cured film, the concentration of the color development was measured by the following method. The lens having the obtained photochromic coating layer was irradiated with a xenon lamp L-2480 (300 W) SHL-100 manufactured by Hamamatsu Photonics K.K. through a UV22 ultraviolet light transmission filter and an HA50 heat ray absorber filter (both are manufactured by Hoya Corporation) with transmission forces of 2.4 mW / cm2 at 365 nm and 24 μ ?? / cm2 at 245 nm on the surface of the polymer at 20 ° C ± 1 ° C for 120 seconds to develop color. The maximum wavelength absorption was measured for the lens with color development in a spectrophotometer (MCPD 3000 instantaneous multichannel photodetector) manufactured by Otsuka Electronics Co., Ltd. The difference, e (120) - e (0), between the absorbance, e (120), at the maximum absorption of wavelength measured above and the absorbance, e (0), was determined at the same wavelength of the cured film in the non-irradiated state, and this value was referred to as the concentration of color development. It can be considered that a higher value means a more excellent photochromic feature. The concentration of the color development of the lens substrate having the photochromic cured film prepared by the aforementioned method was 1.05 at the maximum wavelength absorption of 588 nm, exhibiting excellent photochromic characteristics.

As a result, the adhesion of the lens having the photochromic cured film was evaluated. According to the evaluation method, the lens substrate having the photochromic cured film was immersed in boiling water at 100 ° C for 1 hour, then cooled to room temperature and cross-pattern tested was conducted within 30 minutes. The evaluation criteria are described below. A: No peel B: Peel less than 5% C: Peel more than 5% and less than 15% D: Peel 15% or more The adhesion of the lens substrate prepared by the aforementioned method was A.

(Examples 2 to 15) By a method similar to that for preparing the primer composition (A) in Example 1, the ingredients listed in Table 1 were mixed to obtain the primer compositions (B) to (G). Then, by a method similar to that for preparing the photochromic composition (I) in Example 1, the ingredients listed in Table 2 were mixed to prepare the photochromic compositions (II) to (V). Subsequently, using the lens substrates, the primer compositions and the photochromic polymerizable compositions listed in Table 4, the photochromic cured films were prepared and the appearance, photochromic characteristics and adhesion were evaluated by a method similar to Example 1, except that the coating condition, the distances between the lens substrate and the dispensing nozzle during the coating with the photochromic polymerizable composition and the discharge velocity were changed as shown in Table 3. The results are summarized in Table 4. ( Comparative Examples 1 to 5) Using the lens substrates, the primer compositions and the photochromic polymerizable compositions listed in Table 4, the photochromic cured films, and the appearance, photochromic characteristics and adhesion were evaluated by a similar method to example 1, except that coating condition, the distances between The substrate of the lens and the dispensing nozzle during the coating with the photochromic composition and the discharge rates were changed according to that shown in Table 3. The results are summarized in Table 4.

[Table 1] [Table 2] [Table 3] * Distance (1): the distance between the lens substrate and the dispensing nozzle during the discharge of the photochromic polymerizable composition * Distance (2): the distance between the lens substrate and the dispensing nozzle when the dispensing nozzle is moved outward of the lens substrate after discharge of the photochromic polymerizable composition [Table 4] As clearly seen in the examples mentioned above, if the distance between the lens having the primer layer and the nozzle dispensing the photochromic polymerizable composition is 0.3 mm to 2.5 mm during the discharge of the photochromic composition, a lens substrate that It has an excellent photochromic cured film in appearance, photochromic characteristics and adhesion can be obtained. On the other hand, as shown in the comparative examples, if the distance between the lens having the primer layer and the nozzle dispensing the photochromic polymerizable composition was 3.0 mm or more or if it was 0.1 mm or less, a poor appearance was observed in the area coated with the photochromic polymerizable composition, while the photochromic property and adhesion remained excellent.

Claims (5)

1. - Spinning coating method comprising discharging a coating liquid from the nozzle of the nozzle and applying it by dripping onto a surface of a substrate that rotates to form a uniform coating film on the surface of the substrate, wherein the distance between the nozzle nozzle and the surface of the substrate during the discharge of the coating liquid is 2.5 mm or smaller.

2. - Spinning coating method according to claim 1, wherein the linear velocity during the discharge of the coating liquid is 1 cm / sec or more.

3. - Spinning coating method according to claim 1 or claim 2, wherein the viscosity of the coating liquid is in the range of 50 to 500 cP at 25 ° C.

4. - Spinning coating method according to any of claims 1 to 3, wherein the substrate is a spectacle lens having a primer layer on the surface and the coating liquid comprises a curable composition containing a compound photochromic

5. - Method for producing a substrate a cured film comprising curing a coating film on a substrate obtained by the spin coating method according to any of claims 1 to 4.