JP2009143164A - Manufacturing method and manufacturing apparatus for optical article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing apparatus for an optical article which realize a smooth injection even regarding a raw material composition, has a high viscosity, keeps the injection at a normal temperature difficult by reasons such as the characteristics of the raw material itself, or a time progress after the preparation, and at the same time, do not unfavorably affect the pot life of the raw material composition as well. <P>SOLUTION: This manufacturing apparatus 100 includes a tank 110, a viscometer 120, a mold 130, a raw material feeding apparatus 140, and a control section 150. In this case, the tank 110 houses the raw material composition. The viscometer 120 measures the viscosity of the raw material composition in the tank 110. The mold 130 polymerize-hardens the raw material composition. The raw material feeding apparatus 140 feeds the raw material composition to the mold 130. The control section 150 controls the heating temperature right before the injection of the raw material composition. The raw material feeding apparatus 140 includes a dispenser 141, a raw material distributing pipe 142 and a heater 143. In this case, the dispenser 141 injects the raw material composition into the mold 130. The raw material distributing pipe 142 is connected with the dispenser 141. The heater 143 covers the raw material distributing pipe 142 and is adjacent to the dispenser 141. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and apparatus for manufacturing an optical article such as a plastic lens.

Conventionally, in order to form an optical article such as a plastic lens, a raw material composition prepared by mixing a plurality of materials is injected into a cavity of a mold and polymerized and cured inside the cavity. In this case, the temperature control is performed by passing the raw material composition through a tank or a jacket of a tank subdivided from the tank.
However, when injecting into the glass mold, the temperature of the piping connecting the tank to the injection device is basically not controlled, and the injection is performed without maintaining the temperature controlled in the tank.

The raw material composition in the tank generally has a reaction that gradually progresses with time, and the viscosity increases. The raw material composition at the initial stage of the preparation has a low viscosity, and there is no problem at the time of injection. However, when the viscosity increases with time, it is difficult to inject into the mold.
Therefore, for materials whose viscosity is likely to fluctuate due to the temperature drop or rise in the piping, all the piping to the injection device is doubled and the temperature of the raw material composition is controlled by passing water in the same way as the tank. A method has been proposed (for example, Patent Document 1).

JP 2005-219436 A

  However, when the entire pipe is heated as in Patent Document 1, an increase in viscosity may be suppressed, but there is a concern that the reaction may proceed due to excessive heating and the pot life may be reduced. In particular, for a raw material composition having a high viscosity at the initial stage of preparation, the raw material composition must be heated to a higher temperature in order to realize smooth injection, and the adverse effect on the pot life is likely to be remarkable.

  Accordingly, the object of the present invention is to minimize the adverse effects such as a decrease in pot life of the composition due to heating, and to stably mass-produce the raw material composition having a high viscosity for reasons such as the passage of time. An object of the present invention is to provide a method and an apparatus for manufacturing an optical article.

  The method for producing an optical article of the present invention includes an injection step of injecting a composition stored in a tank into a cavity formed in a mold, and a polymerization for curing the composition injected in the injection step. A heating method so that the temperature of the composition immediately before being injected into the cavity is higher than the temperature of the composition stored in the tank. It is characterized by that.

In this invention, immediately before injecting the composition into the cavity of the mold, the temperature of the composition is heated by the heater so as to be higher than the temperature of the composition in the tank.
Therefore, the viscosity of the composition decreases, and the composition can be smoothly injected into the cavity. As a result, mass production is facilitated, productivity is improved, and a composition having a high viscosity and which has been abandoned can be used without waste. Further, since the entire pipe is not heated, there is no adverse effect such as a decrease in pot life.

  In the method for producing an optical article of the present invention, the injection step preferably controls the temperature of the composition injected into the cavity based on the value of the viscosity of the composition stored in the tank.

The composition prepared in the tank is transported from the tank to the mold through a pipe. When the room temperature is lower than the temperature of the composition controlled in the tank, the viscosity is reduced while being transported inside the pipe. To rise. On the other hand, in order to inject the composition from the pipe into the mold, an optimum viscosity is required for the injection. Since there is a correlation between the viscosity and the temperature, the viscosity can be adjusted by controlling the temperature.
Specifically, in order to smoothly inject into the mold, it is often desirable to make the viscosity of the composition when injected into the mold less than the viscosity of the composition in the tank. For this purpose, the temperature of the composition at the time of pouring into the mold may be made higher than the temperature of the composition in the tank. Controlling the temperature of the composition in this way facilitates mass production, improves productivity, and makes it possible to use a composition having a high viscosity and which has been abandoned without waste. Further, there is no need to increase the temperature of the entire tank and it is not necessary to increase the temperature of the entire pipe, so there is no adverse effect on the pot life.

  The optical article manufacturing apparatus of the present invention includes a tank in which the composition is stored, a mold in which the composition stored in the tank is injected into the cavity, and the composition is injected into the cavity of the mold. An apparatus for manufacturing an optical article comprising a dispenser, comprising: a heater that makes the temperature of the composition immediately before being injected into the cavity higher than the temperature of the composition stored in the tank. .

In the present invention, a dispenser is used when injecting a composition prepared in a tank into a mold. And the heater for raising the temperature of the composition supplied to this dispenser is provided.
Since it is easy to adjust the temperature of the heater, the temperature of the composition can be easily raised to a desired temperature. In addition, since there is a correlation between the viscosity of the composition and the temperature, it can be adjusted to a desired viscosity by setting the temperature.
Therefore, the viscosity of the composition can be reduced, and an optimum viscosity can be obtained when it is injected into the cavity. As a result, mass production is facilitated, productivity is improved, and a composition having a high viscosity and which has been abandoned can be used without waste.

  The optical article manufacturing apparatus of the present invention includes a viscometer that measures the viscosity of the composition stored in the tank, and a control that controls the temperature of the composition injected into the cavity based on the measured value of the viscometer. And an apparatus.

According to the present invention, since the tank is equipped with the viscometer, the viscosity of the composition in the tank can be constantly measured and monitored.
Therefore, when the viscosity of the composition in the tank increases with the lapse of time after the completion of the preparation, it is possible to constantly measure and monitor the degree of increase in the viscosity, and to match the degree of increase in the viscosity of the composition. The temperature of the heater can be adjusted so as to obtain an optimum viscosity at the time of injection.
That is, when the viscosity of the composition is low, heating at a low temperature is sufficient for the heater, and when the viscosity of the composition is high, the heater is heated to a high temperature, thereby reducing the viscosity of the composition at the time of injection. It can be lowered and injected smoothly.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
(Configuration of manufacturing equipment)
FIG. 1 is a schematic view of an optical article manufacturing apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the manufacturing apparatus 100 includes a tank 110 that stores a raw material composition, a viscometer 120 that measures the viscosity of the raw material composition in the tank 110, a mold 130 that polymerizes and cures the raw material composition, A raw material supply device 140 that supplies the raw material composition to the mold 130 and a control unit 150 that controls a temperature at which the raw material composition is heated immediately before injection are provided.

  The raw material used by this invention is not specifically limited, What is generally used as a material of an optical article can be used. For example, (meth) acrylic resin, styrene resin, polycarbonate resin, allyl resin, allyl carbonate resin such as diethylene glycol bisallyl carbonate resin (CR-39), vinyl resin, polyester resin, polyether resin, isocyanate compound and hydroxy such as diethylene glycol Urethane resin obtained by reaction with a compound, thiourethane resin obtained by reacting an isocyanate compound and a polythiol compound, a thioepoxy resin obtained by polymerizing a polymerizable composition containing a compound having a (thio) epoxy group, Examples thereof include resins obtained by polymerizing a polymerizable composition containing a (thio) epoxy compound having one or more disulfide bonds in the molecule. In this embodiment, styrene resin is used.

  The tank 110 is a substantially cylindrical container composed of a bottom surface 111 and a wall surface 112 raised vertically from the bottom surface 111. A mounting hole 113 for mounting the viscometer 120 is formed on the bottom surface 111 side of the wall surface 112. Further, it is desirable that the tank is provided with a temperature control facility such as a water jacket and a stirring device such as a stirring blade.

The viscometer 120 includes a main body part 121 fitted in the mounting hole 113, a detection part 122 that detects the viscosity of the raw material composition at the tip of the main body part 121, and a display device 123 that displays a measurement value at the detection part 122. It is equipped with. The main body 121 and the mounting hole 113 are sealed so that the raw material in the tank 110 does not leak. The detection unit 122 is immersed in the raw material composition in the tank 110. The display device 123 is connected to the main body 121 and displays the viscosity detected by the detection unit 122 as a numerical value.
As the viscometer 120, a commercially available viscometer can be used. For example, an in-line viscometer such as a shield viscometer “FVM80A-ST” manufactured by CBC Corporation can be suitably used.

  The mold 130 is formed by winding a tape 132 around the periphery of a pair of lens molds 131.

  The raw material supply device 140 is a device that supplies a raw material composition to the mold 130, a dispenser 141 that injects the raw material composition into the mold 130, and a raw material distribution in which a lower end portion is connected to a base end portion of the dispenser 141. A pipe 142 and a heater 143 that covers the raw material circulation pipe 142 and is adjacent to the dispenser 141 are provided, and the other end of the raw material circulation pipe 142 is immersed in the raw material composition in the tank 110.

The raw material composition is supplied from the tank 110 to the dispenser 141 through the raw material circulation pipe 142 at a constant pressure. As the dispenser 141, for example, a needle valve type dispenser can be used. In the needle valve type dispenser, compressed air and raw material are introduced, the needle valve opens and closes, and the raw material is discharged from the injection nozzle at the tip while the needle valve is open.
The raw material circulation pipe 142 supplies the composition in the tank 110 to the dispenser 141 at a constant pressure.

The heater 143 is not particularly limited as long as the composition inside the raw material circulation pipe 142 can be heated immediately before being supplied to the dispenser 141. For example, a band heater in which a nichrome ribbon wire is incorporated in a stainless steel film may be used. it can. The band heater is attached so as to wrap around the outer peripheral surface of the raw material circulation pipe 142.
The heater 143 is attached to a part of the raw material circulation pipe 142 adjacent to the dispenser 141.

  The temperature of the heater 143 can be determined according to the viscosity of the raw material composition flowing through the raw material flow pipe 142. What is necessary is just to set about the preset temperature of the heater 143 with respect to the viscosity of a specific raw material composition so that it may become optimal according to the kind and characteristic of a raw material composition to be used. Specifically, a program that raises the heater temperature as the viscosity in the tank increases can be considered.

The control unit 150 includes a heater control unit 151 that controls the temperature of the heater 143 and a dispenser control unit 152 that controls the operation of the dispenser.
The heater control unit 151 may perform control so that the temperature is automatically determined based on a certain calculation formula according to the viscosity of the raw material composition in the tank 110, or the heater control unit 151 may It is also possible for the operator to manually change the set value and control it after confirming the value.
In addition, the dispenser control unit 152 may control the injection amount, injection speed, etc. independently while monitoring the liquid level in the mold 130 or the raw material composition in conjunction with the heater control unit 151. It is also possible to control using data such as temperature and viscosity.

(Method for manufacturing optical article)
Next, a method for manufacturing an optical article by the manufacturing apparatus 100 will be described.
First, the raw material composition is prepared in the tank 110. Specifically, a necessary amount of polymerizable raw materials such as various monomers and oligomers are weighed and put into the tank 110. Two or more kinds of the polymerizable raw materials may be used as necessary. After one or more polymerizable raw materials are charged into the tank 110, the temperature of the tank 110 is adjusted to an appropriate temperature and sufficiently stirred so that the charged raw material composition becomes uniform. At this time, if necessary, an internal mold release agent, an ultraviolet absorber, a light stabilizer, an antioxidant, a crosslinking agent, a bluing agent and the like may be added.

The tank temperature at the time of stirring is generally −10 ° C. to 80 ° C., and more preferably 0 ° C. to 40 ° C. If it is carried out at a very high temperature, there are problems that the polymerization reaction starts early or the raw material composition is colored yellow. Moreover, if it is performed at a low temperature, it is impossible to dissolve the powder (solid) polymerizable raw materials and various additives (powder (solid) such as ultraviolet absorbers), or even if it can be dissolved, it takes a very long time. It is easy for problems to occur. Moreover, you may add a polymerization initiator and a polymerization catalyst before stirring or in the middle of stirring. However, these may be added before or after the degassing step described later in relation to the pot life of the raw material composition.
The stirring time when the raw material composition is prepared using the tank 110 is generally 1 minute to 48 hours, more preferably 5 minutes to 24 hours. In a short time, it is not sufficiently uniform, and in the case of a long time, there is a problem that the polymerization reaction starts. The atmosphere in the tank at the time of stirring can be performed in an atmosphere of an inert gas such as air, nitrogen or argon. The pressure may be increased or decreased in addition to normal pressure.

In preparing the raw material composition, the tank 110 may be used from the beginning as described above, or after preparing the raw material composition using another tank, the prepared raw material composition may be used. It is also possible to transfer to the tank 110 for use.
Furthermore, depending on the raw material composition, a preliminary reaction may be performed in the tank 110. When the preliminary reaction is performed, the reaction can be performed simply by heating the tank temperature, but if necessary, a small amount of a polymerization initiator for the preliminary reaction or a polymerization catalyst may be added. . By performing the preliminary reaction, there is an effect of reducing polymerization shrinkage during polymerization molding and preventing the mold and the molding material from being peeled off during polymerization. In addition, depending on the type of raw material, there is an effect of improving the transparency of the resin after molding by performing a preliminary reaction.

Thus, it is common to perform a deaeration process after preparation of a raw material composition or after completion of a preliminary reaction. The degassing step has an effect of avoiding the appearance of defective bubbles by leaving the bubbles in the cured product after polymerization molding by eliminating minute bubbles entrained during stirring from the raw material composition. In addition, when a raw material composition for urethane resin or thiourethane resin is used, if the trace amount of water is contained in the raw material composition, bubble defects may occur during polymerization molding. By performing the deaeration process, it is possible to reduce the amount of water, and there is an effect of reducing bubble defects.
The deaeration step is generally performed at -10 ° C to 80 ° C for 1 minute to 24 hours under a reduced pressure of 0.001 to 100 torr. However, depending on the raw material composition, if the pressure is reduced too much, the monomer itself contained in the composition volatilizes, and the optimum pressure, temperature, time, etc. vary depending on the raw material composition.

  After the deaeration process is completed, the raw material composition in the tank 110 is injected into the cavity of the mold 130 through the raw material flow pipe 142 and the dispenser 141 by the raw material supply device 140. At this time, the raw material composition flowing in the raw material distribution pipe 142 is heated by the heater 143.

There are the following two reasons for heating.
First, since the raw material distribution pipe 142, the dispenser 141, the mold 130, etc. are usually placed in an indoor room temperature environment (around 25 ° C.), the temperature of the raw material composition passing through the dispenser may be around room temperature. It is common. When the viscosity of the raw material composition at room temperature is too high, the raw material composition does not flow well in the gap of the mold 130 and often overflows to the outside of the mold 130 even when trying to inject into the mold 130. Alternatively, if an attempt is made to inject while avoiding overflow, it is necessary to extremely slow the injection speed, which causes a problem in productivity. Even if it is somehow injected, the air remaining in the mold 130 has a high viscosity of the raw material composition, so that it is often not discharged well, resulting in a defective lens.
Such a phenomenon is likely to occur particularly when a mold for producing a plus power lens having a narrow gap width at the outer peripheral portion of the mold is used. In the mold for plus strength, since the edge of the lens is thin, there may be a gap of 1 mm or less.

In general, the viscosity of the raw material composition that is optimal for pouring is 2 to 500 mPa · s, more preferably 5 to 200 mPa · s, and still more preferably 10 to 100 mPa · s. When the viscosity of the raw material composition is too high, the raw material composition does not flow well through the gap of the mold 130 as described above, and a phenomenon such as flowing out of the mold tends to occur.
When the viscosity of the raw material composition at the time of injection exceeds 500 mPa · s, it is impossible to inject into a mold for a normal plus power lens only by slowing the injection speed, and there is no choice but to greatly widen the mold gap. Even if it is a plus power lens, it is impossible to produce only a lens with a very thick edge and a low commercial value. When the viscosity of the raw material composition at the time of injection exceeds 200 mPa · s, it can be dealt with by slowing down the injection speed or by slightly widening the mold gap. , Leading to an increase in lens edge thickness. When the viscosity of the raw material composition is lowered to 100 mPa · s or less, even a mold for a plus power lens can be smoothly injected, and a large problem often does not occur.
In addition, when the viscosity of the raw material composition is too low, there is no problem in flowing through the gap, but when the flow of the raw material composition becomes too strong and the flow reaches the bottom of the mold 130, There may be adverse effects such as entrapment of minute bubbles due to momentum.

For these reasons, when the viscosity of the raw material composition at room temperature is too high to be injected, it is heated by the heater 143, and the temperature of the raw material composition at the time of injection is increased, thereby increasing the viscosity of the raw material composition. Lowering is effective for smooth injection into the mold 130. In addition, even if the viscosity of the raw material composition at room temperature is 500 mPa · s or less, heating with the heater 143 further reduces the viscosity at the time of injection, thereby realizing a smoother injection. There are many merits such as high speed.
In this case, the heater can be controlled in a stepless manner according to the viscosity of the raw material composition based on 25 ° C., assuming that the room temperature, which is a normal room temperature, is 25 ° C. However, since the effect is small at a temperature very close to normal temperature, the range in which the effect of reducing viscosity is large is 28 ° C. or higher when the normal temperature is 25 ° C., and more preferably 30 ° C. or higher. Or it is +3 degreeC or more with respect to normal temperature, More preferably, it is +5 degreeC or more. When there is a difference between the room temperature and this temperature, the amount of decrease in the viscosity of the raw material composition is large, and the effect at the time of injection is large.

  As a second reason for heating, even if the viscosity of the raw material composition at room temperature is an optimum value for injection, the tank 110 is kept at a low temperature (for example 0 If the distance between the tank and the dispenser is too close, even if the tank is exposed to the room temperature environment while passing through the raw material circulation pipe 142, the time is short, and it is The temperature of the raw material composition cannot be increased, and the raw material composition may be injected at a low temperature, resulting in an increase in viscosity. In this case, it is possible to inject the material with an optimum viscosity by heating the raw material to near room temperature with the heater 143. In this case, the temperature of the raw material composition may be raised to around room temperature, and the heating temperature in the heater does not need to greatly exceed the room temperature. When the room temperature is 25 ° C., a sufficient effect can be obtained even at 30 ° C. or lower. Further, since the raw material composition is not heated except for the heater 143 portion, adverse effects on the pot life are minimized, and energy saving is also achieved.

  In addition, in order to measure the viscosity of the raw material composition immediately before the dispenser 141 of the raw material flow pipe 142, a viscometer may be provided in the raw material flow pipe 142.

According to the present embodiment described above, the following operational effects can be obtained.
(1) In the present embodiment, the heater 143 is provided at a position adjacent to the dispenser 141 and covering the raw material circulation pipe 142. That is, the heater 143 is heated immediately before the raw material composition is injected into the mold 130.
Therefore, the viscosity of the raw material composition at the time of mold 130 injection can be optimized, and the raw material composition can be smoothly injected into the mold 130. Furthermore, since the heating time of the raw material composition is short, adverse effects on the pot life of the raw material composition can be minimized.

  Further, even a raw material composition whose viscosity has increased over time after the degassing step can be smoothly injected into the mold 130 by heating immediately before injection. As a result, mass production is facilitated, productivity is improved, and a composition having a high viscosity and which has been abandoned can be used without waste.

(2) Since the viscosity of the composition can always be measured by the viscometer 120 attached to the tank 110, the management of the viscosity is easy. Further, since there is a correlation between the viscosity and the temperature, the viscosity of the raw material composition immediately before being injected into the mold 130 can be adjusted by controlling the temperature with the heater 143.
Therefore, as in the present embodiment, the viscosity is easily managed, and the heater 143 that can easily control the temperature based on this viscosity is used. Therefore, the viscosity of the raw material composition can be easily controlled.

(3) In this embodiment, the viscometer 120 is attached to the tank 110, and the detection unit 122 is constantly immersed in the raw material composition in the tank 110. Moreover, the viscosity of the raw material composition in the tank 110 can be constantly measured and monitored by displaying the measured value on the display device 123.
Therefore, in order to measure the viscosity of the raw material composition in the tank 110, it is possible to save the trouble of taking a part of the raw material composition out of the tank 110 and measuring the viscosity. Further, there is a possibility that an error may occur when the viscosity is taken out of the tank 110, but in this embodiment, the accurate viscosity of the raw material composition in the tank 110 can be continuously measured. As a result, it is possible to optimize the heating temperature immediately before mold injection, and it can be brought closer to the optimum viscosity at the time of mold injection, and a high-quality product can be manufactured.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that modifications and improvements within the scope of achieving the objects and effects of the present invention are included in the contents of the present invention. Nor.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[Example 1]
In a mixing tank equipped with an in-line viscometer (CBC, product name “FVM80A-ST”), 103 parts by weight of m-xylylene diisocyanate and 4,8or4,7or5,7-dimercaptomethyl-1,11 -Dimercapto-3,6,9-trithiaundecane (100 parts by weight) was mixed, 0.15 part by weight of an internal mold release agent, and 2- (2-hydroxy-5-methylphenyl) -2H- as an ultraviolet absorber. While mixing 3.0 parts by weight of benzotriazole and maintaining the tank temperature at 25 ° C., the mixture was sufficiently stirred for about 1 hour to prepare a raw material composition.
Thereafter, 0.04 part by weight of dibutyltin dichloride was added as a polymerization catalyst, and after further stirring and dissolving, deaeration was performed under a vacuum of 5 mmHg for 30 minutes.
After the degassing, the tank temperature was kept at 25 ° C. and the stirring was continued slowly. The injection into the mold was started after 2 hours had passed after the degassing.
In the injection, the viscosity of the raw material composition in the tank was monitored with an in-line viscometer, and the heating temperature of the heater was adjusted. The relationship between the viscosity and the heating temperature is 30 ° C. when the viscosity is 100 to 200 mPa · s, 35 ° C. when it is 200 to 300 mPa · s, 40 ° C. when it is 300 to 400 mPa · s, and 400 to 500 mPa · s. Was set to 45 ° C. and 500 to 600 mPa · s.
This time, the set value of the heater was manually changed as described above. However, automatic control using a program controller, etc., is performed for heater control, and in accordance with the viscosity of the raw material composition in the tank, step by step or without permission The heater temperature may be controlled on the floor.
The shape of the injected mold was a product having a shape in which the lens power after molding was +5.00 D and the edge thickness was 1.2 mm, and the outer peripheral portion was sealed with an adhesive tape. In addition, the injection | pouring speed | velocity | rate performed the injection | pouring test in two cases, standard speed and low speed, and evaluated whether injection | pouring could be performed smoothly and whether a bubble etc. remain in a lens and it does not become an external appearance defect. The standard speed is a speed that fills the mold in about 60 seconds, and the low speed is a speed that fills the mold in about 3 minutes.
The mold that has been injected is heated from 30 ° C. to 120 ° C. over 20 hours, polymerized and cured, then cooled to room temperature, and then the mold and the cured raw material composition are released to form a plus lens shape. An optical material was obtained. About the lens after mold release, the external appearance was confirmed whether bubbles etc. remain.

[Comparative Example 1]
The same preparation tank and the same raw material as in Example 1 were used to prepare and degas the raw material composition. The storage time and storage conditions after the deaeration process were also performed in the same manner as in Example 1. When the same time as in Example 1 was reached, an injection test at standard speed and low speed was performed. In the injection, the raw material composition was directly injected into the mold without heating with a heater immediately before the injection.

[Example 2]
Using the same formulation tank as in Example 1, 100 parts by weight of diethylene glycol bisallyl carbonate and 0.1 part by weight of 2-2 (2-hydroxy-4-octyloxyphenyl) -benzotriazole as an ultraviolet absorber were mixed, The tank temperature was 25 ° C. and stirring was performed for about 60 minutes. Subsequently, 3 parts by weight of diisopropyl peroxydicarbonate was added as a polymerization initiator, and the mixture was further stirred to be uniform.
Subsequently, this raw material composition was deaerated for 15 minutes under a vacuum of 20 mmHg. After completion of the deaeration, the mixing tank was kept at 25 ° C. and stirring was continued slowly, and an injection experiment was conducted after 3 hours had elapsed after the completion of the deaeration.
In the injection, the heating conditions of the heater were set in the same manner as in Example 1 with respect to the viscosity of the raw material composition in the tank. The injection speed was the same as in Example 1 under the two conditions of standard speed and low speed, and the glass mold used had the same shape and edge thickness as Example 1.
[Comparative Example 2]
The same preparation tank and the same raw material as in Example 2 were used to prepare and degas the raw material composition. The storage time and storage conditions after the deaeration process were also performed in the same manner as in Example 2. When the same time as in Example 2 was reached, an injection test at standard speed and low speed was performed. In the injection, the raw material composition was directly injected into the mold without heating with a heater immediately before the injection.

For each example and each comparative example, the viscosity of the raw material composition in the tank at the time when the injection test was performed, and each condition when the raw material composition was heated to the heater set value, and the standard speed and low speed conditions Table 1 below shows the injection test results (smoothness during injection and the appearance of the lens).
In addition, about the viscosity at the time of heating, at the time of performing the injection test, a small amount of the raw material composition was sampled, and when the viscosity was measured by heating to the heater set temperature with a separately prepared E-type viscometer The value of is used.
The evaluation criteria for the injection result are as follows.
<Evaluation criteria for injection results>
◎: Can be injected without problems ○: Levels where bubbles remain slightly in the lens, but no problem △: Levels where large bubbles remain and lenses are missing ×: Raw material composition overflows from the mold and injection is impossible

  As can be seen from Table 1, in Examples 1 and 2, since heating is performed immediately before injection, the viscosity of the raw material composition can be lowered, and Comparative Example 1 is injected without heating under the same conditions. Compared to 2, smooth injection is possible, and it can be seen that injection in a short time is possible, or that it leads to a reduction in bubble defects during injection.

  The present invention can be used for optical articles such as plastics such as eyeglass lenses, prisms, optical fibers, information recording boards, filters, adhesives, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic of the manufacturing apparatus of the optical material concerning one Embodiment of this invention.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 100 ... Manufacturing apparatus, 110 ... Tank, 120 ... Viscometer, 130 ... Mold, 140 ... Raw material supply apparatus, 141 ... Dispenser, 143 ... Heater, 150 ... Control part

Claims (4)

Production of an optical article comprising an injection step of injecting a composition stored in a tank into a cavity formed inside a mold, and a polymerization step of polymerizing and curing the composition injected in the injection step A method,
A method for producing an optical article, wherein the composition is heated with a heater so that the temperature of the composition immediately before being injected into the cavity is higher than the temperature of the composition stored in the tank. In the manufacturing method of the optical article according to claim 1,
The said injection | pouring process controls the temperature of the composition inject | poured in the said cavity based on the value of the viscosity of the composition accommodated in the said tank, The manufacturing method of the optical article characterized by the above-mentioned. Manufacture of an optical article comprising: a tank in which the composition is stored; a mold for injecting the composition stored in the tank into the cavity; and a dispenser for injecting the composition into the cavity of the mold A device,
An apparatus for manufacturing an optical article, comprising: a heater that makes the temperature of the composition immediately before being injected into the cavity higher than the temperature of the composition stored in the tank. In the manufacturing method of the optical article according to claim 3,
A viscometer for measuring the viscosity of the composition stored in the tank;
An apparatus for manufacturing an optical article, comprising: a control device that controls a temperature of a composition injected into the cavity based on a measurement value of the viscometer.

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