JP3441620B2 - Plastic lens molding die sealing tape - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape for sealing the side surfaces of two glass molds when producing a plastic lens by a casting method.

[0002]

2. Description of the Related Art Among plastic lenses, a casting method is generally used for manufacturing an eyeglass lens which requires particularly high performance. The cast molding method is a method in which a liquid lens raw material is injected into a lens-shaped mold, and is polymerized and cured by heating or radiation irradiation, and then the mold is removed to obtain a lens. The mold used in this cast molding method is generally one in which two glass molds are fixed and sealed with a gasket. However, the gasket has flexibility to follow the shrinkage of the cured product during polymerization, and Since various characteristics such as heat resistance against heating of the above and stability of light energy upon irradiation with radiation are required, there are many restrictions on the materials used, and other types of gaskets are prepared according to the size of the lens. Although it is necessary, since it is disposable, there is the inconvenience that the molding processing cost becomes expensive. Further, since the gasket material may be eluted during injection or during polymerization heating depending on the lens raw material, the gasket material must be changed according to the type of the lens raw material. For the purpose of solving the problem caused by such a gasket, a method has been proposed in which the side surfaces of two glass molds are replaced with gaskets and fixed and sealed using an adhesive tape.

However, in the method using this adhesive tape, the adhesive surface of the adhesive tape to be used and the liquid lens raw material are in direct contact with each other. Therefore, when a normal adhesive tape is used, the components in the adhesive are contained in the lens raw material. It may be eluted to affect the cured state of the raw material, or turbidity may occur in the lens after curing. Therefore, an adhesive tape using an adhesive that solves the problems of curability and turbidity has been studied. For example, in JP-A-61-148282, a tackifying resin composed of rubber and a specific component is used as a main component. An adhesive tape using the above adhesive is disclosed. This tape had insufficient elution resistance to the lens raw material. This is because it has a high solubility in an organic solvent such as acetone, and it is technically difficult to form a crosslinked structure even if it is crosslinked for the purpose of decreasing the solubility. Further, this adhesive also has insufficient heat resistance, and there are many restrictions on the temperature and time during production, and adhesive residue remains on the glass mold, and a cleaning step after release is essential. Further, JP-A-5-255650 discloses an adhesive tape using a pressure-sensitive adhesive composed of an acrylic polymer and having a soluble content in toluene of 30% or less. However, this adhesive tape has a drawback that the lens material used is limited to polycarbonates, polyesters and the like, and is not compatible with a monomer for a thiourethane lens having a high refractive index.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a glass type sealing tape which has excellent chemical resistance and can fix and seal the glass type without using an adhesive. To do.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides an ultraviolet curable resin having a specific composition which is excellent in flexibility and adhesiveness and can be semi-permanently adhered to a flat surface without an adhesive or a fastener, and at any time, easily. It has been completed based on this finding that it can be peeled off. That is, the plastic lens molding sealing tape of the present invention comprises at least one of diallyl phthalate, diallyl isophthalate and diallyl terephthalate and pentaerythritol tetra (3-mercaptopropionate) in a ratio of 2: 1 to 1: 3. It is characterized in that it comprises an ultraviolet-cured product of a polymerization composition which is contained at an equivalent ratio of.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the sealing tape of the present invention contains at least one of diallyl phthalate, diallyl isophthalate and diallyl terephthalate as monomer components and pentaerythritol tetra (3-).
Mercaptopropionate) in an equivalent ratio of 2: 1 to 1: 3. When the amount of at least one of diallyl phthalate, diallyl isophthalate and diallyl terephthalate is larger than this equivalence ratio range, the polymerization is not completed and when the amount of pentaerythritol tetra (3-mercaptopropionate) is large. After polymerization, it becomes a polymer with a strong monomer odor.

In the present invention, at least one of diallyl phthalate, diallyl isophthalate and diallyl terephthalate and pentaerythritol tetra (3) are used.
-Mercaptopropionate) 1.1: 1 to 1: 1.
It is more preferable to use the equivalent ratio of 1 from the viewpoint of the homogeneity of the polymer. Further, in the present invention, diallyl phthalate,
Among diallyl isophthalate and diallyl terephthalate, it is preferable to use diallyl isophthalate in terms of curability and adhesiveness of the polymer.

Further, an ultraviolet curing agent is added to the polymerization composition having an equivalent ratio of the above components for the purpose of causing a polymerization reaction by ultraviolet rays. The addition amount of this ultraviolet curing agent is preferably such that it is contained in the polymerization composition in an amount of 0.005 to 1.0% by weight. The amount of UV curing agent is 0.
If it is less than 005% by weight, sufficient polymerization / curing reaction may not be carried out, and it may cause elution into the lens raw material.
On the contrary, if the addition amount exceeds 1.0% by weight, bubbles are likely to be involved due to the heat generated during the mixing, and bubbles may be included in the cured product to make a smooth product. In such a case, there is a possibility that a gap will be created during the bonding with the glass mold and liquid leakage will occur from there.

The ultraviolet curing agent is not particularly limited,
Various substances can be used, for example, benzoin,
Benzyl, benzoin methyl ether, acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2
-Hydroxy-2-methylpropan-1-one, 4-
(2-Hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenylketone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl- [4- (methylthio)
Phenyl] -2-morpholino-1-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzophenone, 4,4′-bis (dimethylamino) ) Benzophenone, 4,4'-bis (diethylamino) benzophenone, N, N-dimethylaminoacetophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 1-chloroanthraquinone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone , 2, 4,
6-trichloromethyl-s-triazine, 2- (p-chlorophenyl) -4,6-bis (trichloromethyl)-
s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -4'-methoxyphenyl-s-
Triazine, 2- (4-methoxy-naphth-1-yl)
-4,6-bis (trichloromethyl) -s-triazine, 2-p-methoxystyryl-4,6-bis (trichloromethyl) -s-triazine, 2- (2 ', 4'-dimethoxystyryl) -4 , 6-bis (trichloromethyl) -s-triazine, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylbisimidazolyl, 2,2'-bis (o-chlorophenyl) ) −
4,4 ', 5,5'-Tetra- (p-methoxyphenyl) bisimidazolyl, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bisacylphosphine oxide, triphenylphosphine, triphenylphosphite, trilauryl-triti Ophosphite, bis (2,6-dimethoxybenzoyl) -2,4
4-trimethylpentylphosphine oxide, (η ⁵
~ 2,4-cyclopentadien-1-yl) [(1,
2,3,4,5,6-η)-(1-methylethyl) benzene] -iron (1 +)-hexafluorophosphate (1-) and the like, and these may be used alone or in combination of two or more kinds. Can be used. Among these, it is particularly preferable to use 2-hydroxy-2-methyl-1-phenylpropan-1-one and bisacylphosphine oxide in combination. Further, such an ultraviolet curing agent is used as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, triethanolamine, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercapto. It may be used in combination with one or more known photosensitizers such as benzimidazole and 2-mercapto-5-methylthio-1,3,4-thiazole.

The above-mentioned respective components are blended in a dark place to prepare a polymerization composition, which is irradiated with ultraviolet rays to cause a polymerization / curing reaction, and then molded into a film or sheet to form a plastic lens. A mold sealing tape is obtained. The film or sheet can be formed by any known method, for example, a casting method, an inflation method, an extrusion method, a calender method, or the like. Generally, the sealing tape of the present invention preferably has a thickness of 10 to 1000 μm, and is 50 to 50 in terms of moldability and workability.
More preferably, it is 0 μm. The width of the sealing tape varies depending on the thickness of the plastic lens, but it is usually preferable that the width is about 1.5 to 4.5 cm. In addition,
Since the sealing tape of the present invention can be freely cut and used, the width and length can be appropriately adjusted depending on the shape of the glass mold used at the place of use.

Next, a method for producing a plastic lens using the plastic lens molding die sealing tape of the present invention will be described. First, two glass molds are held by a holder, positioned at a predetermined interval and fixed in that state, and the glass mold is laid across the side surfaces of the two fixed glass molds to seal the present invention. A lens can be obtained by forming a set mold by adhering a stop tape, injecting a lens raw material into the set mold, heating the raw material to cure the raw material, and then peeling the tape from the set mold. The sealing tape of the present invention has excellent adhesion to glass,
Despite not having an adhesive layer, the two glass molds can be fixed and sealed by closely contacting the side surfaces of the glass molds.
Further, since no adhesive is used, elution into the liquid lens raw material does not occur, and after the lens raw material is cured, there is no contaminant on the side surface, and it can be peeled off easily and cleanly.

There are no particular restrictions on the lens raw material from which a plastic lens can be produced using the sealing tape of the present invention, and commonly used lens raw materials such as diethylene glycol bisallyl carbonate, diallyl carbonate, diethylene glycol bismethacryl carbonate. Allyl carbonates such as ethylene glycol bisallyl carbonate, unsaturated alcohol esters such as diallyl phthalate, triallyl isocyanurate and diallyl benzoate, unsaturated acid esters such as methyl methacrylate, glycol dimethacrylate and glycidyl methacrylate, styrene and the like. A monomer such as a derivative or a mixture thereof, further m-xylylene diisocyanate, p-xylylene diisocyanate,
Polyisocyanates such as tetrachloro-m-xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate and pentaerythritol tetra (thioglycolate), di (2-mercaptoethyl) ether, Polythiourethane lens monomer formed by reaction with polythiols such as 1,2-ethanediol, 1,4-butanedithiol, ethylene glycol dithioglycolate, trimethylolpropane tris- (thioglycolate), and the like Examples thereof include a prepolymer which is a partial polymer.

[0013]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereby.

Example 1 68.9 parts by weight of diallyl isophthalate, pentaerythritol tetra (3-mercaptopropionate) 6
8.4 parts by weight and 0.14 parts by weight of 1-hydroxycyclohexyl phenyl ketone as an ultraviolet curing agent were mixed in a dark place, and the obtained polymerization composition was prepared 60 cm ×
It was poured into a mold having a size of 80 cm, and when the liquid spread to a uniform thickness, it was irradiated with ultraviolet rays to obtain an ultraviolet cured product. The illuminance at this time was 150 mW / cm ² . The thickness of the obtained ultraviolet cured product was 200 μm. This sheet was cut into a width of 3 cm to form a sealing tape.
Next, two glass molds forming the optical surface of the plastic lens are held and fixed at an interval corresponding to the thickness of the lens, and the tape is attached to the glass mold around the side surface of the glass mold.
The set mold was formed by wrapping and adhering. In the formed set mold, 9.3 parts by weight of m-xylylene diisocyanate and pentaerythritol tetra (thioglycolate) were added.
A liquid lens material prepared by mixing 10.7 parts by weight of a monomer mixture and 0.01 parts by weight of di-n-butyltin dichloride as a thermal polymerization initiator was injected, and the temperature was increased from 40 ° C to 70 ° C over 48 hours. Gradually raise the temperature to polymerize and cure the raw material,
After allowing to cool to room temperature, the tape was peeled off, and the glass mold was removed from the cured product to obtain a lens. The obtained lens was colorless and transparent without turbidity due to elution of the adhesive component, etc., and no sealing tape component remained on the glass type side surface, which is the tape peeling surface.

Example 2 Example 1 was repeated except that diallyl terephthalate was used instead of diallyl isophthalate among the components of the sealing tape.
In the same manner as above, a sealing tape was manufactured and a plastic lens was molded using the sealing tape. The obtained lens was colorless and transparent without stains due to elution of adhesive components and the like, and no sealing tape component remained on the glass mold side surface, which is the tape peeling surface.

Example 3 The same amount of diallyl phthalate was used instead of diallyl isophthalate, and 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propane-1 was used as an ultraviolet curing agent.
Example 1 except that 1.0 part by weight of -one and 0.005 part by weight of 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one were added. A plastic lens mold sealing tape was obtained. When a plastic lens was molded using this tape in the same manner as in Example 1, the lens was colorless and transparent without stains such as elution, and a sealing tape was provided on the glass mold side surface, which is the tape peeling surface. No residual components were observed.

Comparative Example 1 100 parts by weight of natural rubber, 60 parts by weight of a terpene resin, and 30 parts by weight of an aliphatic petroleum resin synthesized from a fraction having 5 carbon atoms were put into 670 parts by weight of toluene and uniformly dissolved and mixed. To produce an adhesive component, which is applied to a 38 μm-thick biaxially stretched polyethylene terephthalate film to a thickness of 40 μm, dried at 120 ° C. for 2 minutes, and stored at 50 ° C. for 3 days to give an adhesive tape. Got When a lens was produced in the same manner as in Example 1 using this tape, turbidity which is considered to be caused by elution of the adhesive component was observed in the lens, and residual adhesive component was observed on the side surface of the glass mold.

[0018]

Since the sealing tape of the present invention is excellent in flexibility and has excellent adhesiveness to glass, it can be adhered to the side surface of the glass mold to fix and seal the two glass molds. You can When the glass mold is set using the sealing tape of the present invention and the plastic lens raw material is polymerized and cured, the adhesive component is not eluted into the liquid lens raw material because no adhesive is used in the sealing tape. It does not occur and the product lens does not become turbid, and it is possible to manufacture high quality lenses, while there is no sealing tape component remaining on the side surface of the glass mold after the lens raw material is cured, and it can be peeled off easily and cleanly. You can In addition, since the sealing tape of the present invention has excellent chemical resistance, it does not cause an abnormality even when it comes into contact with the monomer mixture that is the lens raw material, and may cause an abnormality even if it is washed before use if necessary. In addition, it is excellent in heat resistance against heating during polymerization, and can be applied to polymerization of any lens raw material. Furthermore, since the sealing tape of the present invention is inexpensive, it can be disposable.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C09J 7/00 C09J 7/00 // B29K 67:00 B29K 67:00 B29L 11:00 B29L 11:00 (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 39/00-39/44 B29C 33/00-33/76 C08J 3/00-3/28 C08J 5/00-5/24 C09J 4/00-4/06 C09J 7/00-7/04

Claims (2)

(57) [Claims] 1. An ultraviolet ray of a polymerization composition containing at least one of diallyl phthalate, diallyl isophthalate and diallyl terephthalate and pentaerythritol tetra (3-mercaptopropionate) in an equivalent ratio of 2: 1 to 1: 3. A plastic lens molding encapsulating tape comprising a cured product. 2. The sealing tape according to claim 1, which has a thickness of 10 to 1000 μm.