JPH0142986B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an adhesive tape or sheet for sealing the sides of two molds positioned at a predetermined interval when casting a plastic lens. Regarding.

[Conventional technology]

Conventionally, plastic lenses have been manufactured using methods such as injection molding and hot pressing, but in order to manufacture plastic lenses with excellent performance, cast molding has been adopted.

Cast molding is a method in which diethylene glycol bisallyl carbonate, acrylic ester, methacrylic ester, diallyl ester,
This is a method in which a liquid curable compound such as triallyl isocyanate is injected and cured by heating.

Conventionally, in this method, two molds were fixed and the molds were fixed with a gasket to prevent the liquid curable compound from flowing out from inside the mold.
It is necessary to prepare many types of gaskets according to the shape of the plastic lens, and when taking out the hardened plastic lens, it has to be destroyed, resulting in high molding costs. , it has been proposed to hold two molds with adhesive tape (Japanese Unexamined Patent Publication No. 135030/1983).

[Problem that the invention seeks to solve]

However, in the above method, the adhesive side of the adhesive tape used comes into direct contact with the liquid curable compound. Adhesives and other compounds may dissolve into the liquid curable compound, slowing down the curing of the liquid curable compound, or
There were drawbacks such as turbidity in the plastic lens after curing.

In view of the above-mentioned drawbacks, the present invention aims to prevent the adhesive and other compounds in the adhesive layer from dissolving into the liquid curable compound even when it comes into direct contact with the liquid curable compound for obtaining a plastic lens. The purpose of this invention is to provide an adhesive tape or sheet that does not slow down the curing speed of a chemical compound or cause clouding of a plastic lens after curing.

[Means for solving problems]

The base material used in the present invention can be any material commonly used in conventional adhesive tapes, such as paper, cloth, or plastic film. It is preferable that the film has the strength to fix the film, and it is also preferable that the film has chemical resistance so as not to be damaged by liquid curable compounds, etc., and biaxially oriented polypropylene film and polyethylene terephthalate film are preferably used. used.

Further, the thickness of the base material is not particularly limited, but a thickness of 30 to 100 μm is generally used.

Although any rubber may be used in the present invention, natural rubber and synthetic natural rubber mainly composed of polyisoprene are preferably used.

The tackifier used in the present invention is made from a terpene resin, an alicyclic petroleum resin synthesized from a 5-carbon fraction of petroleum, and an alicyclic petroleum resin synthesized from a 9-carbon petroleum fraction. selected from the group.

The above-mentioned terpene resin is a homopolymer or copolymer of α-binene and β-binene.

The alicyclic petroleum resin synthesized from the 5-carbon fraction of the above-mentioned petroleum is generally a 5-carbon fraction whose main components are isoprene, 1,3 pentadiene, etc. obtained by thermal decomposition of petroleum naphtha. It is a resin obtained by copolymerizing components called.

In addition, the alicyclic petroleum resin synthesized from the 9-carbon fraction of petroleum is the one obtained by extracting BTX (benzene, toluene, xylene) from the 6-11 carbon fraction obtained by thermal decomposition of petroleum naphtha. This is a resin obtained by copolymerizing the residual amount and then hydrogenating it.

The adhesive of the present invention consists of the above-mentioned rubber and the above-mentioned tackifying agent, and the amount added may be determined as appropriate depending on the required quality such as adhesive strength and tack when used, but in general, The tackifier is preferably added in an amount of 40 to 200 parts by weight per 100 parts by weight of rubber.

In addition, the adhesive contains a softener, a crosslinking agent, an inorganic filler,
Anti-aging agents and the like may be added to the extent that they do not dissolve into the liquid curable compound and cause turbidity or inhibit the curing reaction.

The adhesive tape or sheet of the present invention has the above-mentioned adhesive layer formed on one side of the above-mentioned base material, but any conventionally known method may be adopted as a method for forming the adhesive layer, such as the above-mentioned method. A method is adopted in which the adhesive is dissolved in a solvent such as ethyl acetate, toluene, cyclohexane, etc., and the solution is coated on one side of the base material and dried.

In addition, when laminating the adhesive layer on one side of the base material, in order to improve the adhesion between the adhesive and the base material, the surface of the base material may be subjected to corona discharge treatment, plasma discharge treatment, undercoat treatment, etc. Good too.

To show an example of casting a plastic lens using the adhesive tape or sheet of the present invention, first, two glass molds held by a mold holder are positioned at a predetermined interval, and the periphery of the side surface of the mold is , seal with adhesive tape or sheet so that the adhesive layer is on the inside, and use two molds and adhesive tape or sheet,
Forming a cavity in the shape of the plastic lens to be molded. Next, a plastic lens is obtained by injecting a liquid curable compound into this cavity, heating and curing it, and taking it out after curing.

Examples of the liquid curable compound include styrene, styrene substituted with a nuclear halogen, phenyl (meth)acrylate, phenyl (meth)acrylate substituted with a nuclear halogen, benzyl (meth)acrylate, benzyl (meth)acrylate substituted with a nuclear halogen, vinylnaphthalene, Naphthyl (meth)acrylate, (di)(meth)acrylate of tetrabromobisphenol A derivative, divinylbenzene,
diethylene glycol bisallyl carbonate,
Reaction of diallyl carbonate, methyl methacrylate, (di)ethylene glycol di(meth)acrylate of tetrabromobisphenol A derivatives, monohydroxy acrylate of tetrabromobisphenol A derivatives and polyfunctional isocyanates such as xylylene diisocyanate and hexamethylene diisocyanate. Examples include reaction products of monohydroxy acrylate of a nuclear halogen-substituted phenol derivative and a polyfunctional isocyanate, reaction products of a monohydroxy acrylate of a nuclear halogen-substituted biphenyl derivative and a polyfunctional isocyanate, and mixtures thereof.

〔Effect of the invention〕

The composition of the adhesive tape or sheet of the present invention is as described above, and the adhesive is composed of rubber, a terpene resin, an alicyclic petroleum resin synthesized from a 5-carbon fraction of petroleum, and a 9-carbon fraction of petroleum. Since the tackifying agent is selected from the group consisting of more synthesized alicyclic petroleum resins, the adhesive in the adhesive layer and Other compounds do not dissolve into the liquid curable compound, the curing speed of the liquid curable compound does not slow down, and the plastic lens does not become cloudy after curing, resulting in a cloudless plastic lens that can be cast by casting. It is easily molded by the method.

〔Example〕

Next, examples of the present invention will be explained.

Note that "parts" hereinafter mean "parts by weight".

Example 1 Natural rubber 100 parts Terpene resin (manufactured by Yasushi Oil Co., Ltd., trade name YS Resin Px #1000) 60 parts Alicyclic petroleum resin synthesized from a 5-carbon fraction (manufactured by Nippon Zeon Co., Ltd., trade name Quinton B170) )
30 parts Toluene 760 parts The above composition was uniformly dissolved to obtain a 20% adhesive composition.

The resulting adhesive composition was applied to one side of a 38μ thick polyethylene terephthalate film using a doctor blade to reduce the thickness of the adhesive layer after drying.
It was applied to a thickness of 40 μm and dried to obtain an adhesive tape of the present invention.

A width matching tape corresponding to the thickness of the plastic lens to be obtained is attached to the base material side of the adhesive tape obtained, and a mold with two concave and convex parts that form the optical surface of the lens is placed, and the gap between them forms the lens. The adhesive tape was attached to the outer periphery of the side surface of the mold so that both widthwise ends of the width adjusting tape adhered to the adhesive tape coincided with the outer periphery of the mold. Wrap it around once with an overlap of about 1 to 2 cm to ensure complete contact with the mold.

Inside the mold assembled in this way, diethylene glycol bisallyl carbonate 100
and 3 parts of isopropyl peroxycarbonate.
The polymerization was completed by gradually increasing the temperature to ℃ over 20 hours. After slowly cooling to room temperature, when the adhesive tape was removed, the adhesive part of the adhesive tape was sticky, but this was resolved by immersing it in toluene at 40°C for 5 minutes. In addition, mold release was easily performed using a heat shock method.

The obtained lens was clear and colorless, with no turbidity due to melting of the adhesive or chipping due to leakage of the liquid curable compound. Furthermore, the lens was optically good with no distortion.

Example 2 Natural rubber 100 parts Terpene resin (manufactured by Yasuyu Co., Ltd., trade name YS Resin)
Px#700) 30 parts Alicyclic petroleum resin synthesized with 9 carbon atoms (manufactured by Arakawa Chemical Co., Ltd., trade name Alcon P100) 70 parts cyclohexane 800 parts The above composition was uniformly dissolved, and 20% A pressure-sensitive adhesive composition was obtained.

The obtained adhesive composition was applied to one side of a 50μ thick polyethylene terephthalate film using a doctor roll until the thickness of the adhesive layer after drying was 40μ.
The adhesive tape of the present invention was obtained by applying the adhesive tape so as to give the following properties and drying it.

Using the obtained adhesive tape, a casting mold was assembled in the same manner as in Example 1.

In the mold thus assembled, a liquid curing solution consisting of 50 parts of 2,2'-bis(4-methacryloxyethoxy-3,5-dibromophenyl)propane, 50 parts of styrene, and 0.1 part of diisopropyl peroxydicarbonate was added. Inject a chemical compound and heat from 40℃.
The temperature was gradually raised to 110°C over 30 hours to complete polymerization. The mold release was the same as in Example 1.

The obtained lens was colorless and transparent with no chips or turbidity, and had no optical distortion in appearance.

Example 3 Synthetic natural rubber (manufactured by Kuraray Co., Ltd., trade name IR-10)
100 parts terpene resin (manufactured by Yasuyuki Co., Ltd., trade name: YS Resin)
Px#1150) 60 parts turpentine resin (manufactured by Yasushi Yuki Co., Ltd., product name YS Resin
Px#700) 30 parts cyclohexane 760 parts An adhesive tape of the present invention was obtained in the same manner as in Example 1 using the adhesive composition with the above formulation, and cast in the same manner as in Example 1. Assembled the mold for.

In the mold thus assembled, 7 parts of hexamethylene diisocyanate, 2-(4-acryloxyethoxy-3,5-dibromophenyl)-2-
(A liquid curable compound consisting of 63 parts of 4-hydroxyethoxy-3,5-dibromophenylpropane, 30 parts of divinylbenzene, 0.01 part of dibutyltin dilaurate, and 0.1 part of di-8-butyl peroxide was injected, and Polymerization was completed by gradually increasing the temperature to 120° C. over 30 hours. Mold release was the same as in Example 1.

The obtained lens was colorless and transparent without chips or cloudiness, and had no optical distortion in appearance.

Claims (1)

[Scope of Claims] 1. Rubber, terpene resin, aliphatic petroleum resin synthesized from a 5-carbon fraction of petroleum, and alicyclic resin synthesized from a 9-carbon fraction of petroleum on one side of the base material. Sealing around the sides of two molds positioned at a predetermined interval when casting a plastic lens on which an adhesive layer made of a tackifier selected from the group consisting of petroleum-based resins is formed. Adhesive tape or sheet for 2. The adhesive tape or sheet according to claim 1, wherein the rubber is natural rubber. 3. The adhesive tape or sheet according to claim 1, wherein the base material is a polyethylene terephthalate film.