JP2905035B2 - Fixing tape for eyeglass lens polishing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectacle lens polishing tape, and more particularly to a spectacle lens polishing tape used for fixing and protecting a plastic spectacle lens when polishing the spectacle lens.

[0002]

2. Description of the Related Art Plastic eyeglass lenses are usually polished for surface finishing. In this polishing, a low melting point alloy is cast in a block shape on the back side of the polished surface of the lens to be integrated with the lens. A method has been used in which a rotating shaft is attached to a block-shaped low melting point alloy, and the surface to be polished is rotated by the rotation of the rotating shaft to perform polishing. At this time, before casting the low melting point alloy, a removable fixing tape for polishing is applied to the lens to protect the lens surface and secure the adhesion to the alloy before casting the low melting point alloy. The polishing fixing tape has a pressure-sensitive adhesive layer (adhesive surface) on one surface, and the adhesive surface adheres to the back surface of the lens during polishing, and has an action of easily peeling off after polishing, and has another effect. The surface has a heat resistance that enables casting of a low melting point alloy at a temperature equal to or higher than the melting point, and has a function of adhering to the cooled and solidified alloy.

[0003] Therefore, the required properties of the polishing tape are (1) the flexibility to follow the curved surface of the lens, (2) the adhesive used for the tape adhesive surface is a lens,
For example, it has sufficient adhesiveness to a polycarbonate lens, and at the same time, easily peels off after polishing, there is no adhesive residue on the lens surface. (3) The tape non-adhesive surface has heat resistance,
It is excellent in adhesion to a low melting point alloy, and there is no displacement, loosening, or the like between the alloy and the tape during polishing.

[0004] However, it is difficult to satisfy all of these required characteristics. For example, the adhesion between the cast low-melting alloy and the tape is low, and the polishing often causes a problem that the low-melting alloy and the tape, and thus the lens, peel off during polishing. Was.

[0005] In this regard, a surface layer having excellent adhesion to the low melting point alloy is formed, and the tape is coated with an adhesive layer / support /
A method of forming a three-layer structure of a non-adhesive layer (Japanese Patent Publication No.
JP-A-4-146983, or a method using a modified polyolefin resin film having a carboxylic acid group or a carboxylic acid metal base in a side chain on a tape support (JP-A-4-146983).
Publication).

[0006] However, both methods have the disadvantage of increasing costs in terms of materials and production.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing tape for polishing which has improved fixation holding force between a cast low melting point alloy and a lens without increasing costs in terms of materials and production. It is in.

[0008]

The inventors of the present invention have repeatedly studied to find such a fixing tape for polishing. As a result, the use of a polyester block copolymer as a flexible film material can easily solve the problem. The present invention has been found, and the present invention has been achieved.

That is, the present invention is a fixing tape for polishing spectacle lenses, wherein a pressure-sensitive adhesive layer for fixing a spectacle lens to be polished is provided on one side of a flexible film, and the other side is fixed by a low melting point metal. A fixing tape for polishing eyeglass lenses, characterized in that a film made of a block copolymerized polyester of a high melting point aromatic polyester A and a polyester B having a glass transition temperature of 0 ° C. or lower is used as the flexible film. In particular, when a polyacrylate-based pressure-sensitive adhesive is selected as the pressure-sensitive adhesive, a preferable fixing tape is obtained.

The present invention will be described. The block copolymer polyester of the present invention comprises a high melting point polyester A and a polyester B having a glass transition temperature of 0 ° C. or lower,
As the high melting point polyester A, a crystalline polyester having a melting point of 180 ° C. or more, particularly 200 ° C. or more is preferably used. For example, terephthalic acid, naphthalene-2,
A polyester of 6-dicarboxylic acid and tetramethylene glycol is particularly preferably used. On the other hand, as polyester B having a glass transition temperature of 0 ° C. or lower, aliphatic, alicyclic and aromatic dicarboxylic acids and polyesters obtained from a combination of aliphatic diols have a glass transition temperature of 0 ° C. or lower, preferably − What is necessary is just 5 degrees C or less. For example, a dicarboxylic acid selected from an aromatic dicarboxylic acid such as isophthalic acid and phthalic acid and an aliphatic dicarboxylic acid and a carbon number of 6 to 6
Polyester with 12 diols. The polyester is preferably low crystalline or amorphous. In the case of crystalline, the melting point is preferably 50 ° C. or less.

The ratio of polyester A to polyester B constituting such a block copolymerized polyester is 50: 5.
0-25 to 75 is preferred. A known production method can be applied to the production of this copolymer, and a method in which a high-molecular weight polyester A and a polyester B are melt-mixed and reacted until the melting point of the homopolymer of the polyester A is lowered by 2 to 30 ° C. Is common. The intrinsic viscosity of the block copolymerized polyester (measured in orthochlorophenol at 35 ° C.) is 0.7 or more, preferably 0.9 or more.

[0012] The polyester film has a thickness of 50
It is preferably from 300 to 300 μm.

Basically, such a film can be easily manufactured by a conventional film forming method.

The block copolymer polyester film of the present invention has a pressure-sensitive adhesive layer on one surface. This pressure-sensitive adhesive demonstrates sufficient adhesive strength during polishing,
Although it is easily peeled off after polishing, a polyacrylate-based adhesive (adhesive) is preferable. As such a polyacrylate-based adhesive, for example, an alkyl acrylate such as butyl acrylate or isooctyl acrylate is mainly used. Preferred are polyacrylate adhesives. Further, a natural rubber adhesive or a thermoplastic rubber adhesive can also be used. Such a pressure-sensitive adhesive has a peel force against a lens of 150 to 3000 g / inch, or even 5 to 3000 g / inch.
It is preferably from 00 to 2550 g / inch. In addition, the pressure-sensitive adhesive may contain a coloring agent, an antioxidant, an adhesion enhancer (tackifier) and the like.

The pressure-sensitive adhesive layer can be formed by applying a coating solution containing an effective concentration of a pressure-sensitive adhesive to a block copolymer polyester film and drying.
The coating thickness is about 15 to 60 μm as a rough guide.

The present invention will be further described with reference to the drawings. FIG. 1 is a schematic partial cross-sectional view showing the use of a polishing tape. In the drawing, 1 is a block copolymer polyester film, 2 is an eyeglass lens, 3 is a low melting point alloy, 4 is a fixing stand, and 5 is a polishing unit.

The polishing tape of the present invention is useful for polishing plastic lenses, especially polycarbonate lenses.
Further, an ophthalmic lens is preferable as the spectacle lens.

[0018]

The present invention will be further described below with reference to examples.

[0019]

Example 1 184 parts of dimethyl isophthalate, 12 parts of dimethyl sebacate and 140 of hexamethylene glycol
The part was polymerized by a conventional method using a titanium butoxide catalyst to obtain a polyester B having an intrinsic viscosity of 1.15. Polybutylene terephthalate (intrinsic viscosity 1.02; melting point 2) obtained by separately polymerizing 70 parts of this polyester B at 240 ° C.
20 ° C.) (the melting point is measured by heating at a differential scanning calorimeter of 20 ° C./min), and the mixture is mixed under reduced pressure. After 40 minutes, phosphorous acid is added to stop the reaction. I took out. This polymer had a melting point of 203 ° C, an intrinsic viscosity of 1.16, and a glass transition temperature of -5 ° C.

This block polyester was extruded from a T-die and solidified by a cooling roll at 60 ° C. to prepare a film. An emulsion of a polyacrylate-based pressure-sensitive adhesive (90% by weight of isooctyl acrylate and 10% by weight of acrylic acid) is applied to one side of the film and dried. Obtained.

An unpolished lens is attached to the pressure-sensitive adhesive surface of this tape in the same manner as in the drawing, and Bi45%, Pb23%,
A low-melting alloy composed of 11% of Sn, 19% of In and 2% of Ga was used and fixed to a fixing table. The opposite surface of the lens was polished, but the lens could be polished smoothly without detachment. After polishing, the lens was removed, but the adhesive was good without remaining on the lens.

[0022]

Examples 2-3 The block copolymerized polyester was prepared in the same manner as in Example 1 except that the composition of the polyester B and the ratio of the polybutylene terephthalate as the polyester A (as in Example 1) were changed as shown in the table. The same polishing test as in Example 1 was performed using the fixing tape on which the was obtained, formed into a sheet, and coated with an adhesive. The results are shown in Table 1.

[0023]

[Table 1]

[0024]

Comparative Example 1 A sheet was prepared in the same manner as in Example 1 except that the block copolymerized polyester of the present invention was replaced by polybutylene terephthalate (intrinsic viscosity 1.51) obtained by copolymerizing 63% by weight of polytetramethylene glycol having an average molecular weight of 2,000. A polishing test was performed by applying an adhesive, but the adhesion with the low melting point alloy was not sufficient, and the polishing could not be performed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view schematically showing a usage state of a fixing tape of the present invention. In FIG. 1, 1 is a fixing tape, 2
Denotes a spectacle lens, 3 denotes a low melting point alloy, 4 denotes a fixing table, and 5 denotes a polishing unit.

Continuation of front page (56) References JP-A-3-36795 (JP, A) JP-A-55-151076 (JP, A) JP-A-56-135582 (JP, A) JP-A-5-70749 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B24B 13/005 C09J 7/02

Claims (2)

(57) [Claims] 1. A fixing tape for polishing spectacle lenses, comprising a pressure-sensitive adhesive layer for fixing a spectacle lens to be polished on one side of a flexible film, and the other side fixed by a low melting point alloy. A fixing tape for polishing spectacle lenses, wherein a film made of a block copolyether of a high melting point aromatic polyester A and a polyester B having a glass transition temperature of 0 ° C. or lower is used as the flexible film. 2. The fixing tape for polishing eyeglass lenses according to claim 1, wherein the pressure-sensitive adhesive is a polyacrylate-based pressure-sensitive adhesive.