JPH10296603A - Protective material for fixing sheet-like lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily separate a protective material after grinding and polishing, by interposing a sheetlike article, composed of an optical hardened article of a polimeric composition including diallylphthalate and pentaerythritoltetra at a specific equivalent ratio, between a fixed member and a lens. SOLUTION: A working block 4 is constituted of a spindle part 4a, having a rotatably symmetric shape with the center line of a rotation spindle 3 as the center, and fitted to the spindle 3, and a cup part 4b for fixing a lens 1; and forms a circular recesses part 4c, to be adopted as a lens fixing member and filled with a low-melting point metal 8, on the end surface of the cup part 4b. A protective material 10; which is a sheet-like material composed of the optical hardened article of a polymeric composition including one kind of diallylisophtalate, and diallylterephthakate, and pentaerythritoltetra at an equivalent ratio of 2:1-1:3; is interposed between the cup part 4b forming the recesses part 4c and the lens 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective material for fixing a sheet-like lens. More specifically, the present invention relates to a sheet for fixing a lens to a fixing member for processing and fixing the lens to the fixing member when the lens is fixed to a fixing member for processing and grinding and polishing. The present invention relates to a protective material for fixing a lens.

[0002]

2. Description of the Related Art Conventionally, as a method of cutting and finishing a lens, a lens is fixed to a rotation axis,
2. Description of the Related Art A method of grinding and polishing by rotating a lens while a grinding wheel is in contact with a processing surface of the lens via a grinding agent, an abrasive, or the like is generally widely used.

However, in the case of a small and thin lens such as a spectacle lens, it is not easy to fix and hold the lens on the rotating shaft using a jig or the like during grinding and polishing. Therefore, the fixed holding of these lenses on the rotation axis is performed by casting a low melting point metal as a fixing member on the back surface of the surface to be processed of the lens in a block shape or a thick film shape, and integrating the lens with the rotation axis. It is performed by integrating with the low melting point metal layer.

[0004] In this case, when the low melting point metal is cast directly on the lens surface as a fixing member as described above, when the low melting point metal is removed after grinding and polishing, the lens surface may be stained or damaged.

On the other hand, instead of casting the low-melting metal, a cup-shaped processing block that can be connected to a rotating shaft is used, and a low-melting metal for bonding is injected into the block to separate the processing block and the lens. After fixing, a method has been proposed in which the rotating shaft and the lens are fixed by connecting the processing block to the rotating shaft. In this method, when removing the low melting point metal or the processing block, the lens surface is removed. However, the problem that stains and scratches occur on the surface cannot be solved.

Therefore, there has been proposed a method of attaching a sheet-like lens protecting material before attaching the processing block to the lens. As a material of such a sheet, a polyolefin film having an adhesive layer, a polyvinyl chloride film, a polyurethane film, a polyester film and the like are known.

The sheet-like lens protecting material is interposed between the processing block and the lens to fix them and protect the lens. After grinding and polishing, the lens is moved to the processing block. After being removed from the lens, it can be peeled off from the back surface of the lens.

[0008]

However, in the method using the sheet-like lens protective material made of the above-mentioned material, since the adhesiveness of the protective material to the lens is low, there is a possibility that the lens is displaced and detached during grinding or polishing. Often had occurred. Therefore, the rotation speed of the lens during grinding or polishing could not be made too high.

In this regard, it has been considered to provide another adhesive layer for improving the adhesion to the lens on the surface of the sheet-like lens protection material. However, the surface layer for improving the adhesion may be provided. The formation has a disadvantage that the manufacturing process of the lens protection material becomes very complicated and causes an increase in manufacturing cost. On the other hand, the adhesiveness is too high, which makes it difficult to peel off the adhesive, which may cause dirt and scratches on the lens surface during peeling. Is further required, and the adverse effect that the complexity of the process is increased sometimes occurs.

[0010] In view of the above problems, the present invention aims at protecting a lens by forming a protective material firmly on a lens surface by its own high adhesive force without forming an adhesive layer. Another object of the present invention is to provide a sheet-like lens fixing protective material that can be easily peeled off in the process of peeling the protective material after grinding and polishing while realizing a high rotation of the lens during grinding and polishing. And

[0011]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems and as a result have reached the following invention.

That is, the present invention provides a protective material for fixing a lens interposed between a lens and a fixing member for grinding and polishing the lens, wherein the protective material comprises at least one of diallyl phthalate, diallyl isophthalate and diallyl terephthalate. A sheet-like material comprising a photocurable product of a polymerizable composition containing pentaerythritol tetra (3-mercaptopropionate) in an equivalent ratio of 2: 1 to 1: 3, for fixing a sheet-like lens. Provide protective material.

The sheet-like lens fixing protective material of the present invention comprises:
Because of its high adhesiveness, it can be strongly adhered to the lens surface without separately forming an adhesive. As a result, there is no displacement or detachment of the lens in the grinding / polishing process, and the fixability of the lens to the fixing member is significantly improved.
As a result, the rotation speed of the lens during grinding or polishing can be increased. Further, since the protective material of the present invention can be easily peeled off from the lens, the sheet can be easily peeled off without leaving dirt or scratches on the lens surface after the grinding / polishing processing.

[0014]

Embodiments of the present invention will be described below. The protective material for fixing a sheet-like lens of the present invention,
It consists of a photocurable product of a polymerizable composition containing a photocurable polymerizable monomer.

(1) Polymerizable composition (i) Polymerizable monomer The polymerizable composition of the present invention comprises, as a polymerizable monomer component,
At least one of diallyl phthalate, diallyl isophthalate and diallyl terephthalate as a diallyl component and pentaerythritol tetra (3-mercaptopropionate) as a functional group-containing component in a ratio of 2: 1
１ ： 1: 3 equivalent ratio. When the amount of the diallyl component exceeds this equivalent ratio range, the polymerization reaction is not completed, and the unpolymerized portion remains in a liquid state. In addition, when the amount of the functional group-containing component increases, a polymer having a strong monomer odor after polymerization is obtained.

The diallyl component and the functional group-containing component are:
It is more preferable to use an equivalent ratio of 1: 1 to 1: 1.1 from the viewpoint that the polymerization reaction is performed uniformly and a photocured product with high uniformity is obtained. It is preferable to use diallyl isophthalate as the diallyl component in view of the curability and adhesion of the polymer.

(Ii) Photopolymerization Initiator In the present invention, a photopolymerization initiator is usually added to the polymerizable composition for the purpose of causing a photopolymerization / curing reaction. The amount of the photopolymerization initiator is preferably 0.01 to 10% by weight based on the total amount of the polymerizable composition. If the amount of the photopolymerization initiator is less than 0.01% by weight, a sufficient polymerization / curing reaction does not occur, and if the amount exceeds 10% by weight, the reaction proceeds too much to increase the viscosity of the liquid or generate heat. The stability as a liquid will be impaired, for example, it will become violent. The amount is 1
When the amount does not exceed 0% by weight, the stability of the liquid is maintained, and the workability and safety in the polymerization step and the like are maintained.

The photopolymerization initiator is not particularly limited, and various types 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-
Trithiophosphite, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, (η ^{5 to} 2,4-cyclopentadiene-1
-Yl) [(1,2,3,4,5,6-η)-(1-methylethyl) benzene] -iron (1 +)-hexafluorophosphate (1-). Or a combination of two or more.

Among them, in particular, 2-hydroxy-2
It is preferable to use a combination of -methyl-1-phenylpropan-1-one and bisacylphosphine oxide.

Further, such an ultraviolet curing agent may be N, N
-Dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, triethanolamine, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-5-methylthio-1 ,
One or two of known photosensitizers such as 3,4-thiazole
More than one species may be used in combination.

(Iii) Other components In addition to the polymerizable monomer and the photopolymerization initiator, a curing accelerator, an antifoaming agent, a leveling agent, etc. , A pigment, a disperse dye and the like can be added as necessary.

(Iv) Preparation of polymerizable composition The method for preparing the polymerizable composition of the present invention is not particularly limited as long as the above components can be uniformly mixed. Specifically, the polymerizable monomer, photopolymerization initiator, and necessary additives are uniformly mixed and stirred in a dark place by a known method.

Various solvents can be used for the purpose of uniformly mixing the components. The solvent to be used is not particularly limited. For example, aliphatic hydrocarbon solvents such as n-hexane, n-decane and cyclohexane, aromatic hydrocarbon solvents such as benzene, toluene and xylene, butyl acetate, benzyl acetate Ester solvents such as, methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, butyl carbitol,
Examples thereof include alcohol solvents such as methyl cellosolve acetate, ethylene glycol and diethylene glycol, ketone solvents such as methyl ethyl ketone, and derivatives thereof.

(2) Protective material for fixing lens in sheet form The protective material for fixing lens of the present invention can be manufactured by the following method. That is, first, a solution of the polymerizable composition is formed into a sheet by casting or the like, and is irradiated with light from above to perform photopolymerization and curing, thereby forming a sheet-like lens made of a photocured product of the polymerizable composition. A fixing protection material can be obtained.

As the irradiation light, ultraviolet rays are usually used, but electron beams can also be used. The conditions for light irradiation are not particularly limited, and a conventionally known method can be employed.

The thickness of the sheet-like lens fixing protective material of the present invention is usually 0.1 to 1 mm, preferably 0.2 to 0.1 mm.
9 mm. In the present invention, for the purpose of facilitating the distinction between the lens and the protective material, such as when peeling the protective material from the lens, to enhance the workability of the grinding and polishing process,
The protective material for fixing a sheet-like lens after photo-curing the polymerizable composition can be dyed. There is no limitation on the dyeing method, and dyeing can be performed by a commonly used dyeing process. As the dye at this time, for example, an aqueous solvent-based disperse dye or an alcohol-based organic dye is used.

(3) Grinding and Polishing of Lens The protective material for fixing a sheet-like lens according to the present embodiment includes a rotating shaft and a fixing member for grinding and polishing of the lens connected to the rotating shaft. In a grinding / polishing processing apparatus in which a lens is rotated to grind and polish the lens by driving the rotation shaft while being fixed to a fixed member,
It is used by being interposed between the lens and the fixing member, and plays a role of bonding and fixing the lens to the fixing member and protecting the lens. That is, the sheet-like lens fixing protective material according to the present embodiment is attached to the surface (rear surface) of the lens opposite to the surface to be processed, and the fixing member is bonded and fixed on the sheet-like lens fixing protective material. You. Then, in a state where a grinding tool (a grindstone or the like) is brought into contact with the surface to be processed of the lens, the rotating shaft connected and fixed to the fixing member is rotated to rotate the lens, thereby grinding or polishing the processed surface of the lens. Is performed.

Hereinafter, an example of lens processing (grinding / polishing) using the sheet-like lens fixing / protecting material according to the present embodiment will be specifically described. FIG. 1 is a plan view showing the structure of a curve generator for lens processing.

As shown in FIG. 1, the curve generator includes a work part A and a grindstone part B. The work part A is fixed on the X table 2 with the X table 2 slid on the bed (not shown) in the X direction (left and right direction in FIG. 1) and its rotation axis (work axis) 3 oriented in the X direction. A work spindle 11 and a processing block 4 detachably attached to the tip of the rotating shaft 3 by a bayonet or a screw. This processing block 4 has a rotationally symmetrical shape about the center line of the rotating shaft 3, and as shown in an enlarged sectional view of FIG. 2, a shaft attached to the rotating shaft 3 of the work spindle 11. It comprises a portion 4a and a cup portion 4b for fixing the lens 1, which is a workpiece. The end surface of the cup portion 4b is formed in a spherical shape having a predetermined curvature, and a circular concave portion 4c in which a low-melting-point metal (adhesive metal) 8 is filled when the lens 1 is fixed is formed in the center thereof. . A metal injection port 4d for injecting the bonding metal 8 into the circular concave portion 4c is provided between the circular concave portion 4c and the tip end surface of the shaft portion 4a.
Is penetrating. In addition, as the bonding metal 8, a metal known in the art can be used. However, after processing the lens, the processing block 4 and the lens 1 are immersed in warm water or the like to dissolve the bonding metal 8 and release the bonding metal 8 from the protective material. ,
Usually, those having a melting point of 45 to 60 ° C are suitable. Specifically, alloys such as bismuth, lead, tin, cadmium, and indium are used.

On the other hand, the grindstone portion B
Y table 5 that slides in the direction (vertical direction in FIG. 1)
On the Y table 5 in the Z direction (X direction and Y direction).
Rotating around a θ axis oriented in a direction perpendicular to the direction
Table 6 and a grinding wheel spindle 12 fixed on the θ table 6 with its rotation axis (grinding wheel axis) 7 orthogonal to the θ axis
And a grindstone holder 9 attached to the tip of the grindstone shaft 7. A cup grindstone C having a cylindrical shape with a bottom and having a circular recess at the center of the end face is fixed to the tip of the grindstone holder 9. The grindstone holder 9 and the cup grindstone C are coaxial with the grindstone shaft 7.

In order to fix the lens 1 to the above-described curve generator, first, the sheet-like lens fixing protective material 10 according to the present embodiment is attached to the back surface 1b of the lens 1 while extending as little gap as possible. . Then
A processing block 4 in which the curvature of the end surface of the cup portion 4b matches the curvature of the back surface 1b of the lens 1 is selected, and the end surface of the cup portion 4b of the processing block 4 is passed through the sheet-like lens fixing protective material 10. To the rear surface 1b of the lens 1. Then, the bonding metal 8 is injected into the circular recess 4c through the metal injection port 4d. Thereafter, it is air-dried for a certain period of time, and waits until the bonding metal 8 is solidified and the lens 1 is fixed to the processing block 4. After the bonding metal is hardened, the processing block 4 is connected to the rotating shaft 3.

Next, the .theta. Table 6 is appropriately rotated, and the angle of the grindstone shaft 7 with respect to the work axis 3 (hereinafter referred to as "grindstone angle") corresponds to the design value of the curvature of the surface 1a to be processed of the lens 1. Adjust to an angle. At this time, when the surface to be processed of the lens 1 (the surface in contact with the grindstone C) is processed into a spherical concave surface,
Since the edge of the grindstone C must be in contact with the surface to be processed of the lens 1 at the center of the work shaft 3, the positions of the tables X and Y are appropriately adjusted.

After the above, both spindles 11 and 12 are rotated for a predetermined time while spraying a known grinding (polishing) liquid or a grinding (polishing) agent between the lens 1 and the grindstone C.
Perform grinding and polishing.

In the above working example, as the fixing member,
Although the combination of the processing block 4 and the low melting point metal 8 designed to be connectable to the rotating shaft 3 is used, the configuration of the fixing member is not limited to this. For example, the entire fixing member may be made of the low melting point metal 8, and the fixing member made of the low melting point metal 8 may be connected to the rotating shaft 3. In this case, the low-melting-point metal 8 is cast directly on the sheet-like lens fixing protective material 10 adhered to the lens 1 in a block shape or a thick film shape.

Since the sheet-like lens fixing protective material according to the present embodiment has a high adhesiveness itself, it can be strongly adhered to the lens surface without separately forming an adhesive. As a result, the fixability of the lens protection material during the grinding / polishing process is improved. In addition, there is no need to provide an additional adhesive layer for improving the adhesiveness, and the manufacturing cost can be suppressed. On the other hand, the sheet-like lens fixing protective material of the present invention is easy to peel off the sheet after the processing is completed, and does not cause stains or scratches on the lens surface at the time of peeling.

[0037]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

[0038]

Example 1 5.52 parts by weight of diallyl phthalate, 5.48 parts by weight of pentaerythritol tetra (3-mercaptopropionate), and 2-methyl- [4- (methylthio) phenyl] -2 as a photopolymerization initiator Morpholino-1-propan-1-one 0.01 parts by weight in a dark place
The mixture was stirred and mixed for an hour to obtain a polymerizable composition.

The obtained solution of the polymerizable composition is poured into a prepared 10 cm × 10 cm mold, and when the solution has spread to a uniform thickness, the polymerizable composition is cured by irradiating ultraviolet rays. Thus, a sheet-like lens fixing protective material having a thickness of 0.8 mm was obtained. The illuminance of the ultraviolet light at this time was 300 mW /
cm ² .

The workability of the obtained sheet-like lens fixing protective material was actually examined using a curve generator as shown in FIGS. 1 and 2 in the following manner. In other words, after extending the sheet-shaped lens fixing protective material on the surface (back surface) opposite to the processing surface of the lens to be ground without any gaps, protect the processing block that matches the curve of the lens. Put on top of the material, and from the opening hole in the upper part of the block, the bonding metal (alloy composition: 44.3% bismuth, 22.1% lead, 8.7% tin, 5.6% cadmium, 19.3% indium) Low-melting point alloy), and air-dry with cold air for about 30 minutes to fix the lens and the processing block. After the bonding metal is hardened, the rotary shaft is connected to the claw of the processing block and fixed. Grinding was performed by moving the rotating shaft in a state in which a grinding agent and a grinding fluid were brought into contact with the processed surface of. Further, in the polishing step, processing was performed in the same manner except that the abrasive and the polishing liquid were replaced with the abrasive and the polishing liquid. At the time of this processing, no displacement or detachment of the lens was observed.

After the processing was completed, the rotating shaft was removed, and the processing block was immersed together with the processed lens in 70 ° C. hot water for 15 minutes to melt the bonding metal and remove the processing block from the protective material. When the protective material was peeled off from the lens surface by hand, it could be easily peeled off. No scratches, dirt, etc. remained on the rear surface of the lens, and no change was observed as compared to before processing.

[0042]

Example 2 Example 1 except that diallyl phthalate was replaced by diallyl isophthalate as a component of the polymerizable composition.
When grinding and polishing were performed in the same manner as in the above, processing was performed smoothly, there was no detachment of the lens, etc., and no scratches, dirt, etc. remained on the back of the lens after processing, and before processing There was no change compared to.

[0043]

Example 3 As a photopolymerization initiator in a polymerizable composition, 2
2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one instead of -methyl- [4- (methylthio) phenyl] -2-morpholino-1-propan-1-one Was ground and polished in the same manner as in Example 1 except that 0.006 parts by weight was added, the processing was performed smoothly, there was no detachment of the lens, and the like. In the state, no scratches, dirt, etc. remained, and no change was observed as compared with the state before processing.

[0044]

Example 4 Example 1 except that diallyl phthalate was replaced by diallyl terephthalate as a component of the polymerizable composition.
When grinding and polishing were performed in the same manner as in the above, the processing was performed smoothly, there was no detachment of the lens, etc., and the condition of the back of the lens after processing, no scratches, dirt etc. remained at all, No change was seen in comparison.

[0045]

Comparative Example 1 An adhesive (trade name: Liquidine AR-825, Sankyo Chemical Co., Ltd.) was applied to one side of a commercially available ethylene-propylene copolymer film as a protective material for fixing a sheet-like lens.
Was ground and polished in the same manner as in Example 1 except that a protective material prepared by applying a transfer method so that the dry thickness became 25 μm was used, and the processing was performed smoothly. However, the lens was slightly misaligned. Also, after processing, remove the rotating shaft, immerse in warm water to dissolve the metal for bonding, remove the processing block, and then peel off the protective material by hand from the lens surface. It could not be removed and some adhesive remained on the lens surface.

[0046]

Comparative Example 2 As a protective material for fixing a sheet-like lens, a commercially available ethylene-propylene copolymer film was coated on one side with an ethylene copolymer resin-based adhesive (trade name: Hondain, Sumika CFD Chemical Co., Ltd.). ) Was ground and polished in the same manner as in Example 1 except that a protective material prepared by applying a transfer method so that the dry thickness became 30 μm was used. There was no lens displacement or detachment. After processing, remove the rotating shaft, immerse in hot water to dissolve the metal for bonding, remove the processing block, and then peel off the protective material by hand from the lens surface. It was torn and left on the lens surface.

[0047]

According to the protective material for fixing a sheet-like lens of the present invention, since the adhesion between the lens surface and the protective material is excellent, the fixing and holding performance of the lens during grinding and polishing is improved.
Trouble is less likely to occur than when a conventional sheet-like protective material provided with an adhesive layer is used. Further, such a fixed holding performance makes it possible to increase the rotation of the lens during grinding and polishing. In addition, since the protective material of the present invention can be easily peeled as well as adherence, the speed of the grinding and polishing steps and the quality of processed products can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a structure of a grinding / polishing apparatus (curve generator) shown as a preferred embodiment in an embodiment of the present invention.

FIG. 2 is an II-I of the apparatus for grinding and polishing shown in FIG.
FIG. 2 is a partially enlarged longitudinal sectional view taken along a line I.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lens 16 ... Back surface of lens 10 ... Protective material for fixing sheet-like lens 4 ... Processing block 4d ... Metal injection port 8 ... Metal for adhesion 3 ... Rotation axis 1a: Surface to be processed of lens

Claims (3)

[Claims] 1. A lens fixing protective material interposed between a lens and a lens-grinding / polishing fixing member, comprising 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. 2. The protective material for fixing a sheet-like lens according to claim 1, wherein a photopolymerization initiator is incorporated in the polymerizable composition in an amount of 0.01 to 10% by weight. 3. The sheet-like lens fixing protective material according to claim 1, which is a sheet-like material having a thickness of 0.1 to 1 mm.