JP2003131174A - Method of manufacturing lens molded goods and cleaning agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environmentally considered new cleaning agent and a method of manufacturing a plastic lens utilizing a cleaning method using the cleaning agent. SOLUTION: The method of manufacturing the lens molded goods comprising injecting a lens monomer of a diethylene glycol bis-allyl carbonate system into the cavity of a lens casting mold combined with a sealing material and molds and subjecting the monomer to casting polymerization, then removing the sealing material and cleaning the lens molded goods together with the molds with the cleaning agent containing glycol ether and water. The cleaning agent for the plastic lens or the plastic lens molds containing the glycol ether and the water.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a plastic lens for spectacles based on diethylene glycol bisallyl carbonate (hereinafter sometimes abbreviated as DAC),
And a cleaning agent for plastic lenses or plastic lens molds. More specifically, the present invention provides
Plastic lens molding (here, for example, refers to a state in which the gasket is removed and the lens is sandwiched between glass molds after polymerization) and a plastic lens molding mold (for example, a glass mold) attached to a plastic molding The present invention relates to a cleaning agent for cleaning raw materials, unreacted monomers, oligomers, polymers, high molecular weight resinous stains such as components bleeding out from a gasket, and a method for producing a plastic lens using the same.

[0002]

2. Description of the Related Art The resin most widely used as a plastic lens for spectacles is a resin whose main component is diethylene glycol bisallyl carbonate (hereinafter referred to as DAC), and is generally molded by a cast polymerization method. Target. In cast polymerization, a resin monomer is injected into the cavity of a molding mold consisting of a glass molding die and a gasket, and the temperature is controlled by an electric furnace or the like to carry out the polymerization. Then, after the polymerization is completed, the gasket is removed and the molded lens is peeled off from the mold. Since the DAC is anaerobic during this mold release work, unreacted monomer on the outside of the mold that has adhered or leaked during the injection work may adhere to hands or jump, which hinders the work. In addition, unreacted monomers, oligomers, polymers, components bleeding out from the gasket, and many plastic molding materials adhere to the molded product after polymerization.

Therefore, a chemical removal method has been used for the purpose of removing those components from the molded lens and the mold. As a chemical removal method, for example, a cleaning operation before a mold release step with a cleaning liquid using trichlorethylene or a surfactant has been generally performed.

[0004]

However, since the above-mentioned trichlorethylene is a harmful substance, it is required to switch to a substitute product in view of environmental problems and occupational safety and health. In addition, since the washing step including the surfactant requires a rinsing step with water or the like, there is concern that the drainage may affect the environment. Then, the objective of this invention is providing the manufacturing method of the plastic lens using the cleaning agent which replaces these cleaning agents mentioned above, and the cleaning method using the cleaning agent.

[0005]

The present invention which solves the above problems is as follows. [Claim 1] A diethylene glycol bisallyl carbonate-based lens monomer is injected into a cavity of a lens mold in which a sealant and a mold are incorporated, and after casting polymerization, the sealant is removed to obtain the lens molded product. A method for producing a lens molded article, which comprises: cleaning the above-mentioned mold with a cleaning agent containing glycol ether and water. [Claim 2] The method according to claim 1, wherein the detergent has a glycol ether content of 30 to 95%. [Claim 3] The glycol ether contained in the detergent has a boiling point range of 50 to 300 ° C and a molecular weight of 5
It is 0-500, The manufacturing method of Claim 1 or 2 characterized by the above-mentioned. [Claim 4] Cleaning of the lens molded product and the mold includes a first cleaning step of cleaning the lens molded product and the mold with a cleaning liquid containing glycol ether and water, and a cleaning liquid used in the first cleaning process. The second cleaning step of rinsing with a cleaning solution containing the same glycol ether, and a drying step of drying the cleaned lens molded product and mold are performed. The manufacturing method according to the description. [Claim 5] A part of the cleaning liquid in the first cleaning step is extracted, at least glycol ether is regenerated from the extracted liquid, and the regenerated glycol ether is supplied to the first cleaning step or the second cleaning step. 4. The manufacturing method according to 4. [Claim 6] The method according to claim 5, wherein the glycol ether is regenerated by vacuum distillation using a distillation regenerator. [Claim 7] A cleaning agent for a plastic lens or a plastic lens mold, which contains glycol ether and water. [Claim 8] The content of glycol ether is 30 to 95%.
The cleaning agent according to claim 7, wherein [Claim 9] The boiling point range of glycol ether is 50 to
The cleaning agent according to claim 7 or 8, which has a molecular weight of 50 to 500 at 300 ° C. [Claim 10] The cleaning agent according to any one of claims 7 to 9, wherein the plastic lens is a diethylene glycol bisallyl carbonate-based lens.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A diethylene glycol bisallyl carbonate-based lens (DAC
System lens) is a lens known as a DAC system lens, and the composition thereof is not particularly limited. For example, DA
The C lens has a DAC of 20 to 1 as a monomer component.
It is obtained by polymerizing a monomer solution containing 100% of the above components, and other components such as diallyl phthalate, styrene and methyl methacrylate, a polymerization initiator, an ultraviolet absorber and the like as a monomer component other than DAC.

As a mold used as a mold, glass is generally used in many cases, but the material is not particularly limited, and may be metal, ceramic or the like. The sealing material is not particularly limited either, but a resin gasket or tape type is generally used. In the production method of the present invention, the casting method and conditions for casting the DAC lens are not particularly limited. Known methods and conditions can be used as they are.

In the manufacturing method of the present invention, after the casting polymerization, the sealing material is removed, and the lens molded product is washed together with the mold. The detergent used in the production method of the present invention and the detergent of the present invention contain glycol ether and water. The glycol ether is preferably selected from glycol ethers having a molecular weight of 50 to 500 and a boiling point range of 50 to 300 ° C. It is preferable to use a glycol ether having a molecular weight and a boiling point in this range, since a washing step with another detergent (another organic solvent, water, etc.) as an additional step is not required after the washing.

Examples of glycol ethers including glycol ethers having such a molecular weight and a boiling point include the following compounds. 2-methoxyethanol (molecular weight 76.09, boiling point 124.6 ° C), 2-ethoxyethanol (molecular weight 90.12, boiling point 135.6 ° C), 2- (methoxymethoxy) ethanol (molecular weight 106.12, boiling point 167.5 ° C), 2-isopropoxyethanol (molecular weight 104.09). , Boiling point 139-143
), 2-butoxyethanol (molecular weight 118.17, boiling point 170.
2 ° C), 2- (isopentyloxy) ethanol (molecular weight 1
36.13, boiling point 181 ° C), 2- (hexyloxy) ethanol (molecular weight 146.23, boiling point 208.1 ° C), 2-phenoxyethanol (molecular weight 138.16, boiling point 244.7 ° C), 2- (benzyloxy) ethanol (molecular weight 152.19, boiling point 256 ° C) , Diethylene glycol (molecular weight 106.12, boiling point 244.8 ℃), diethylene glycol monomethyl ether (molecular weight 120.15,
Boiling point 194.1 ° C), diethylene glycol monoethyl ether (molecular weight 134.17, boiling point 202.0 ° C), diethylene glycol monobutyl ether (molecular weight 162.23, boiling point 230.4 ° C),
Triethylene glycol (molecular weight 150.17, boiling point 288.0
° C), triethylene glycol monomethyl ether (molecular weight 164.21, boiling point 249 ° C), tetraethylene glycol (molecular weight 194.23, boiling point 327.3 ° C), polyethylene glycol
(Molecular weight 150-800, boiling point 50-300 ° C),

1-methoxy-2-propanol (molecular weight 9
0.12, boiling point 120 ° C), 1-ethoxy-2-propanol
(Molecular weight 104.15, boiling point 137.5-13 ° C), 2-ethoxy-1-
Propanol (molecular weight 104.15, boiling point 124.6 ° C), dipropylene glycol (molecular weight 134.17, boiling point 231.8 ° C), dipropylene glycol monomethyl ether (molecular weight 148.20,
Boiling point 190 ° C), dipropylene glycol monoethyl ether (molecular weight 162.22, boiling point 197.8 ° C), tripropylene glycol monomethyl ether (molecular weight 206.28, boiling point 243)
℃), polypropylene glycol (molecular weight 400-500, boiling point
50-300 ° C) 3-Methyl-3-methoxybutanol (molecular weight 118, boiling point
174 ° C) dipropylene glycol methyl ether (molecular weight 148.2,
Boiling point 188.3 ° C) Tripropylene glycol methyl ether (Molecular weight 206.
3, boiling point 242.4 ℃) Propylene glycol methyl ether acetate (molecular weight 132.2, boiling point 146 ℃) ethylene glycol ethyl ether acetate (molecular weight 1
32.2, boiling point 156.3 ° C) Propylene glycol ethyl ether acetate (molecular weight 146.2, boiling point 158 ° C) 3-methyl-3-methoxybutyl acetate (molecular weight 16
0.2, boiling point 188 ° C) 1,2-diethoxyethane (molecular weight 118.17, boiling point 121.4
1,2-butoxyethane (molecular weight 174.28, boiling point 203.3 ° C) diethylene glycol dimethyl ether (molecular weight 134.1
8, boiling point 159.76 ℃) Diethylene glycol diethyl ether (molecular weight 162.2
2, boiling point 188.4 ℃) diethylene glycol dibutyl ether (molecular weight 218.3
3, boiling point 254.6 ℃) ethylene glycol diglycidyl ether (molecular weight 174.
2, boiling point 112 (4.5 mn) ° C) ethylene glycol monoethyl ether acetate (molecular weight 132.2, boiling point 156.3 ° C) ethylene glycol monobutyl ether acetate (molecular weight 160.2, boiling point 192 ° C) ethylene glycol monohexyl ether (molecular weight 146.
3, boiling point 208.3 ° C) ethylene glycol monomethyl ether acetate (molecular weight 118.2, boiling point 145 ° C) diethylene glycol ethyl methyl ether (molecular weight 14
8.2, boiling point 179 ° C)

The detergent used in the production method of the present invention and the detergent of the present invention preferably have a glycol ether content of 30% by weight or more, and more preferably 50% by weight to 95% by weight. . The cleaning agent contains water in addition to glycol ether. The reason is that glycol ether has a flash point, which reduces the risk of operational ignition. Therefore, when the water content is 70% by weight or more, the detergency is reduced. The cleaning agent may include one kind or two or more kinds of glycol ethers.

The cleaning of the lens molded product and the mold with the above cleaning agent is preferably used in combination with, for example, ultrasonic irradiation because a high cleaning effect can be obtained. In that case, since the temperature of the casting polymerization is generally 50 to 150 ° C., a rapid temperature change is suppressed, and the lens molding is performed at an inappropriate time due to the difference in shrinkage between the lens molded product and the mold. It is preferable to control the temperature so as to keep it constant in order to prevent the product from separating from the mold. 20 to wash
The temperature may be in the range of 90 ° C, preferably 60 to 90.
C., more preferably 70 to 85.degree.

The cleaning of the lens molded product and the mold is the same as the first cleaning step of cleaning the lens molded product and the mold with a cleaning liquid containing glycol ether and water, and the same cleaning liquid used in the first cleaning process. It preferably comprises a second washing step of rinsing with a washing solution containing glycol ether, and a drying step of drying the washed lens molded product and mold.

FIG. 2 shows the configuration of an ultrasonic cleaning device for performing the first cleaning step, the second cleaning step and the drying step.
Based on this, a detailed description will be given below. FIG. 2 is an explanatory view of the cleaning device. This cleaning apparatus is composed of a stainless steel cleaning tank 1, a pulling tank 2, and a drying tank 3. The first washing step is carried out in the washing tank 1, the second washing step is carried out in the pulling tank 2, and the drying step is carried out in the drying tank 3. The cleaning tank 1 contains the cleaning agent (cleaning liquid) of the present invention, and an ultrasonic device 11 is attached for the purpose of enhancing the cleaning effect.
Temperature control is performed by (not shown). The pulling tank 2 is composed of a first tank 21 and a second tank 22 whose temperature is controlled by a heater 23, and is filled with a cleaning liquid containing the same glycol ether as the cleaning liquid as a rinsing liquid. Second tank 22
The liquid overflowed in the first tank 21 moves to the first tank 21
The liquid overflowed in the tank 21 is moved to the cleaning tank 1.

A circulation mechanism 24 for pumping the liquid from the first tank 21 to the second tank 22 through a filter is provided between the first tank 21 and the second tank 22. , The first tank
The rinsing liquid is circulated from 21 to the second tank 22. on the other hand,
Above the tank, the overflow from the second tank 22 to the first tank due to overflow.
Since the cleaning liquid is supplied to the first tank 21, the rinsing liquid is constantly circulated between the first tank 21 and the second tank 22.

The drying tank 3 has a heater 31 and an air blower 32.
The molded product and the mold, which are sent into the tank by the hot air supply means, are dried with hot air.

The lens molded product and the mold are conveyed to these tanks by moving the racks holding the lens molded product and the mold up and down and back and forth.
It is possible to swing up and down in the tank and advance it to each tank so as to feed the rack holding the molded product and the mold.

Further, in the manufacturing method of the present invention, a part of the cleaning liquid in the first cleaning step is extracted, glycol ether is regenerated from the extracted liquid, and the glycol ether is supplied to the first cleaning step or the second cleaning step. it can. For the above method, an apparatus equipped with the cleaning liquid regeneration treatment apparatus 4 shown in FIG. 2 can be used. However, in the cleaning liquid regeneration treatment device shown in FIG. 2, a distillation regeneration device is used to recover the glycol ether. The regeneration treatment device 4 is composed of a storage tank 41 and a distillation regeneration device 42, and the storage tank 41 is composed of a stock solution tank 43 and a regeneration solution tank 44. The stock solution tank 43 is a tank for temporarily storing the cleaning solution overflowed from the cleaning tank 1,
It is stored here and appropriately sent to the distillation / regeneration device 43 through a pipe. Further, a regenerant liquid tank 44 is installed in the stock solution tank 43 so that the reclaimed solution can overflow from the reclaimed solution tank 44 to the stock solution tank 43 so that the level of the reclaimed solution tank 44 can be controlled. Has become. The regenerant liquid tank 44 stores the regenerant liquid regenerated by the distillation regenerator 42, and when regeneration is completed, it is sent to the regenerant liquid tank 44 through a pipe at any time. Also,
The stock solution tank 43 and the reclaimed solution tank 44 are temperature-controlled by a heater, preferably about 80 ° C.

The distillation regenerator 44 distills the cleaning liquid under reduced pressure. The glycol ether and water are recovered by distillation, and those not distilled are discharged as waste liquid. The distillation is preferably carried out at a reduced pressure of 40 mmHg or less at 50 to 200 ° C., and the glycol ether and water recovered by distillation are sent to the regenerant tank 44. As for the degree of reduced pressure during distillation, when the degree of reduced pressure is high, it is possible to distill at a lower temperature, and when the degree of reduced pressure is low, a high liquid temperature is required.

To regenerate the cleaning agent, an oil / water separation system or a distillation regeneration system is generally used. The oil-water separation method is
This is a method that utilizes the difference in affinity and the specific gravity difference between the waste and the cleaning liquid, but it is difficult to remove 100% of the waste, and if the waste is completely dissolved in the cleaning liquid, it cannot be separated. The DAC used in the present invention is almost dissolved in a mixed solution of glycol ether and water. On the other hand, the distillation regeneration method as opposed to the oil-water separation method is a method utilizing the boiling point difference between the cleaning liquid and the waste, and when the boiling point difference between the cleaning liquid and the waste is small, or when the boiling point of the waste is lower, it cannot be used. However, if the boiling point difference is large, complete separation is possible. As the distillation regeneration method, a reduced pressure method is preferably used for the distillation regeneration. Distillation under reduced pressure lowers the boiling point of the cleaning solution and requires less heat for distillation. Also, reducing the pressure reduces the oxygen concentration in the distillation pot, so it contains hydrocarbon solvents. Even if the substance has a flash point or a substance that has a flash point during distillation, there is an advantage that the risk of ignition is reduced and the safety can be maintained. Moreover, the boiling point of DAC, which is a raw material for the lens molded article produced in the present invention, is 16.6 ° C. at 2 mmHg, and the difference in boiling point from glycol ether is large, so that the distillation regeneration method can be used. By carrying out the distillation regeneration, the cleaning liquid component can be distilled and reused, and the waste liquid remains in the distillation pot as a residue and is discharged as a waste liquid.

By providing a waste liquid tank before the distillation / regeneration device, it is possible to balance the liquid supply to the distillation / regeneration device. Furthermore, by providing these tanks, it is possible to compensate for the amount of liquid evaporated from the cleaning tank and to use the liquid for a long time without replenishing the liquid.

Since the boiling point of water is different from that of glycol ether, which is a cleaning component, it is effective to install a water content adjusting tank for distillate. Further, this water content adjusting tank not only serves to balance the water content, but also serves to adjust the unevenness of the amount of the distilled regenerated liquid over time. Moisture meter in the regenerant tank
The water content of the regenerant is controlled at 45, and is controlled so that it does not fall below a certain level. This is to prevent the risk of flammability of glycol ether, which is a component of the cleaning liquid, and is preferable as a practical measure as a safety measure in a lens mass production factory. And from the regeneration tank 44 to the pulling tank
The regenerant is sent to 2 and replenished. The replenishment is controlled by a valve with a flow meter. And the raising tank
The replenishing liquid overflows from 2 and is supplied to the cleaning tank 1 to form a circulation cycle of the cleaning liquid.

[0023]

EXAMPLES The present invention will now be described in more detail with reference to examples. (Lens Molding) Hereinafter, lens molding will be described with reference to FIG. Figure 1 (a) is a diagram illustrating the formation of a mold in the cast molding method of a plastic lens for eyeglasses, (b)
[FIG. 3] is a cross-sectional view of the mold, and (c) is a cross-sectional view of a molded product. DAC 100 parts by weight, diisopropyl peroxydicarbonate 3 parts by weight, polyether modified surfactant 30 parts by weight
pm (against DAC) and 0.03 parts by weight of 2-hydroxy-4-n-octoxybenzophenone as a UV absorber, a lens monomer, two glass mother molds consisting of an upper mold 51 and a lower mold 52, and a polyethylene mold. Inject into the cavity of the molding mold 54 with the gasket 53 assembled, and
Polymerization was carried out at 50 ° C. for 5 hours, 60 ° C. for 3 hours, 70 ° C. for 2 hours, and 80 ° C. for 2 hours. After the polymerization was completed, the gasket 53 was removed, and then a molded product 56 including glass molds 51 and 52 and a lens 55 sandwiched between the molds was obtained.

(Washing Step) The molded product 56 was packed in a stainless steel holding rack of an ultrasonic washing device and set in the carrying mechanism of the washing device shown in FIG. In the cleaning device 1, the molded product 55 is placed on the holding rack, immersed in a cleaning tank, and while being vertically swung, irradiated with ultrasonic waves,
Wash for 5 seconds to 10 minutes. The temperature of the washing tank at this time is 80
℃. Then, this rack is pulled up from the washing tank and moved to the next pulling tank by the carrying means. A rinsing liquid containing the same components as the cleaning tank is contained in the pulling tank, and the rack is lowered into the drawing tank, immersed, and oscillated up and down to perform rinsing for 5 seconds to 10 minutes. . Then, this rack is pulled up from the pulling tank and moved to the next drying tank by the carrying means. In the drying tank, this rack is lowered, and while being vertically swung, it is heated by a heater and hot air is blown to dry the molded product. Then, the rack is pulled up from the drying tank, the rack is transferred from the cleaning device, and the molded product is taken out. Then, as a result of evaluating the cleaning effect by visual observation under a fluorescent lamp, it was confirmed that the cleaning was successfully performed. Next, in the releasing step, the lens molded product 55 was released from the glass molds 51 and 52 to obtain a lens.

[0025]

According to the manufacturing method and the cleaning agent of the present invention,
The load on the environment can be reduced and good detergency can be maintained, as compared with the case of using detergency which has been conventionally used, using trichlorethylene or a surfactant. In addition, the excellent effect of high safety for the human body at the time of washing is exhibited.

[Brief description of drawings]

FIG. 1 is an explanatory view of a lens molding process.

FIG. 2 is an explanatory diagram of a cleaning device.

Claims (10)

[Claims] 1. A lens molded product obtained by injecting a diethylene glycol bisallyl carbonate-based lens monomer into a cavity of a lens mold in which a sealing material and a molding die are incorporated, casting polymerization, and then removing the sealing material. A method for producing a lens molded article, which comprises: cleaning the above-mentioned mold with a cleaning agent containing glycol ether and water. 2. The method according to claim 1, wherein the detergent has a glycol ether content of 30 to 95%. 3. The glycol ether contained in the detergent has a boiling point range of 50 to 300 ° C. and a molecular weight of 5
It is 0-500, The manufacturing method of Claim 1 or 2 characterized by the above-mentioned. 4. The cleaning of the lens molded product and the mold includes a first cleaning step of cleaning the lens molded product and the mold with a cleaning liquid containing glycol ether and water, and a cleaning liquid used in the first cleaning process. The second cleaning step of rinsing with a cleaning solution containing the same glycol ether, and a drying step of drying the cleaned lens molded product and mold are performed. The manufacturing method according to the description. 5. A part of the cleaning liquid in the first cleaning step is extracted, at least glycol ether is regenerated from the extracted liquid, and the regenerated glycol ether is supplied to the first cleaning step or the second cleaning step. 4. The manufacturing method according to 4. 6. The production method according to claim 5, wherein the glycol ether is regenerated by vacuum distillation using a distillation regenerator. 7. A cleaning agent for a plastic lens or a plastic lens mold, which contains glycol ether and water. 8. A glycol ether content of 30 to 95%
The cleaning agent according to claim 7, wherein 9. Glycol ether has a boiling point range of 50 to 50.
The cleaning agent according to claim 7 or 8, which has a molecular weight of 50 to 500 at 300 ° C. 10. The cleaning agent according to any one of claims 7 to 9, wherein the plastic lens is a diethylene glycol bisallyl carbonate type lens.