JP2008201025A - Shaping mold for molding polymerization - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaping mold for molding polymerization capable of manufacturing a lens material which is obtained by polymerizing a monomer composition comprising at least a silicone-containing unsaturated monomer and has excellent oxygen permeability and functional physical properties. <P>SOLUTION: In the shaping mold for molding polymerization for molding an ophthalmic lens material to be aimed by polymerizing a monomer composition at least comprising the silicone-containing unsaturated monomer stored in a molding cavity, at least a site providing the molding cavity is composed of a polypropylene with the total amount of the content of an additive being in a range of 500-2,000 ppm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mold for mold polymerization, and particularly to an ophthalmic lens product such as a contact lens or an intraocular lens using a monomer composition containing a silicone-containing unsaturated monomer.

  In recent years, disposable (disposable) hydrous soft contact lenses have appeared, and when they are easy to use and dirty or damaged, they can be easily replaced with new lenses for use. The population of contact lens wearers is increasing. And since such a disposable lens is premised on replacement in a short period of time, it is naturally strongly required that it can be supplied to lens consumers at a low cost. Therefore, the “mold polymerization method” that can minimize the manufacturing cost is usually employed for the production of the disposable lens.

  By the way, conventionally known contact lens manufacturing methods can be roughly classified into three types, and besides the mold polymerization method described above, there are a cutting polishing method and a spin casting method. Among them, the cutting and polishing method is a method of manufacturing a desired contact lens by cutting out a lens material such as a plate shape or a rod shape with a lathe and performing a cutting and polishing process. In addition, the cutting and polishing method is a method suitable for manufacturing contact lenses that require products of different types of standards, and in particular, hard contact lenses that require such types of standard products. Is advantageously employed in the manufacture of However, the above-described method has a problem in that the number of steps is large and it takes a long time to manufacture or a lot of lens material is discarded as cutting waste, so that the increase in manufacturing cost cannot be avoided.

  On the other hand, the mold polymerization method and the spin cast method are mainly used for the production of soft contact lenses. As is well known, in the former mold polymerization method, a polymerizable monomer composition is filled in a mold having a molding cavity corresponding to a desired lens shape, and the monomer composition is polymerized. This is a method for producing a target contact lens. In the latter spin casting method, the polymerizable monomer composition is poured into a rotating mold, and the monomer composition is expanded by the centrifugal force to form a lens shape. A method of manufacturing a lens.

  These mold polymerization method and spin cast method require a mold having high surface accuracy for each standard when manufacturing various types of contact lenses with different standards. Since the manufacturing cost increases, it is not suitable for manufacturing hard contact lenses that require many kinds of standard products. However, when manufacturing soft contact lenses, the soft contact lenses are flexible, fitted according to the shape of the wearer's cornea, and applied to most wearers with one or two base curve standards. Since the number of types of molds required is small, these methods can be preferably employed.

  Moreover, these mold polymerization method and spin casting method can simplify the manufacturing process and reduce the amount of the monomer composition used to the minimum as compared with the cutting and polishing method. It has the advantage that mass production can be realized. Accordingly, these methods are particularly advantageously employed in the production of contact lenses with high consumption, such as disposable soft contact lenses.

  By the way, in the mold polymerization method, generally, a resin mold that is manufactured by injection molding is used in consideration of the releasability of the lens material that is a polymer of the monomer composition and its moldability. ing. In the resin used for the mold, a stabilizer, a plasticizer, a lubricant, an antioxidant, a neutralizing agent, an antiaging agent and the like are usually added as additives.

  On the other hand, in the monomer composition, hydrophilic monomers such as 2-hydroxyethyl methacrylate, methacrylic acid, acrylic acid, N-vinylpyrrolidone and dimethylacrylamide, and alkyl (meth) such as methyl (meth) acrylate and ethyl (meth) acrylate In addition to polyfunctional monomers such as acrylate, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, and the like, monomers generally used for ophthalmic lenses are conventionally used.

  In Patent Document 1 related to the background art of the present invention, as a mold for mold polymerization of a monomer composition containing at least a nitrogen-containing unsaturated monomer, at least a portion providing a molding cavity is a long-chain hydrocarbon-modified polyamide. A mold polymerization mold characterized by being made of resin is disclosed.

  Patent Document 2 relates to a mold for an ophthalmic lens and a method for producing an ophthalmic lens, and discloses the use of polypropylene and polyamide as a molding material.

In patent document 3, a polymeric material for producing a half mold for use in the production of contact lenses, wherein the material is in the range of 0.1-20% in the thermoplastic polymer and the thermoplastic material. It is disclosed to include internal additives in amounts. Patent Document 3 discloses that the thermoplastic material is polystyrene or polypropylene, and the additive is polyethylene or polypropylene wax having a molecular weight of 5,000 to 200,000.
JP 2003-291158 A JP 2000-185325 A Japanese Patent No. 3764778

  By the way, the oxygen permeability of the soft contact lens conventionally produced by the mold polymerization method is low because it depends on the moisture content, and is inferior to the oxygen permeable hard contact lens.

  However, in recent years, ophthalmic lens materials comprising a monomer composition containing a silicone-containing unsaturated monomer (such as a silicone hydrogel soft contact lens having improved oxygen permeability so that it can withstand long-term continuous wear even with soft contact lenses) Hereinafter, simply referred to as a lens material) has been proposed.

  And, when a monomer composition containing such a silicone-containing unsaturated monomer is mold-polymerized with a resin mold similar to the conventional one to obtain a contact lens, the affinity with the resin mold is poor, There are problems such as bubbles generated in the obtained lens material, inferred to be caused by polymerization distortion, and curling of the lens material in a water-containing state.

  Further, the present inventors have found that the composition of the surface and the inside of the lens material is likely to be different, which may cause deformation of the lens material or a decrease in strength after release. It became clear. Here, since silicone originally has hydrophobic and lipophilic properties, it was considered that the silicone-containing unsaturated monomer caused elution of the additive contained in the resin mold.

  In Patent Documents 1 to 3, in a mold polymerization mold for suitably obtaining an ophthalmic lens product such as a contact lens or an intraocular lens or a lens blank using a silicone-containing unsaturated monomer, the same mold is used. There is no disclosure or suggestion as to how the total content of additives contained in the polymerization mold is made.

  The present invention has been made in the context of the above circumstances, and produces a lens material obtained by polymerizing a monomer composition containing at least a silicone-containing unsaturated monomer with excellent oxygen permeability and functional properties. An object of the present invention is to provide a mold for mold polymerization that can be used.

  The invention of claim 1 of the present application provides a molding die for molding an objective ophthalmic lens material by containing a monomer composition containing at least a silicone-containing unsaturated monomer in a molding cavity and polymerizing the monomer composition. The gist of the mold for mold polymerization is characterized in that at least the part that gives the molding cavity is made of polypropylene having a total content of additives in the range of 500 to 2000 ppm.

  The invention of claim 2 is characterized in that, in claim 1, the additives contained in the polypropylene are an antioxidant and a neutralizing agent.

  By using the mold of the present invention, the moldability, polymerizability, detachability and specifications of an ophthalmic lens material comprising a monomer composition containing a silicone-containing unsaturated monomer can be made suitable. As a result, a lens material for the same eye can be manufactured with excellent oxygen permeability and functional properties.

Embodiments of the present invention will be described below.
The mold for mold polymerization according to an embodiment of the present invention is a mold for polymerizing a monomer composition composed of a plurality of unsaturated monomers including at least a silicone-containing unsaturated monomer. The mold is composed of, for example, a male mold and a female mold. The two male molds and the female mold are combined to form a molding cavity having a shape that gives a desired lens material (for example, a lens blank that is a semi-finished contact lens) between the molds. Is done.

  Then, the entire mold may be made of polypropylene, or only the portion providing the molding cavity may be made of polypropylene. Note that polypropylene is not special and may be commercially available.

Furthermore, in order to obtain a mold, an antioxidant and a neutralizing agent are added in appropriate amounts as additives.
(Antioxidant)
Antioxidants include phenolic antioxidants or hydroxylamine antioxidants. This antioxidant is a radical scavenger and is intended to prevent the degradation caused by radicals generated in the resin due to external factors such as oxygen, heat, and ultraviolet rays from growing in a chain reaction.

  Examples of phenolic antioxidants include tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, tris (2,4-di-t-butylphenyl) phosphite, 2,6-di-t-butyl-p-cresol, 2,2'-ethylidene-bis (4,6-di-t-butylphenol), 2-t-butyl-6- (3-t-butyl-2 -Hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris ( 3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, tris (4-t -Butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 3,9-bis [1,1-dimethyl-2- {β- (3-t-butyl-4-hydroxy-5-methylphenyl) Propionyloxy} Tyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 2,2-bis [4- [2- (3,5-di-t-butyl-4-hydroxyphenylpropionyloxy) Ethoxy] phenyl] propane, bis [2- (3′-t-butyl-2′-hydroxy-5′-methylbenzyl) -6-t-butyl-4-methylphenyl] terephthalate, bis [3,3-bis (4'-Hydroxy-3'-t-butylphenyl) butyric acid] ethylene glycol ester, etc. can be mentioned, these are appropriately selected and used alone or in admixture of two or more. Can do.

  In addition, hydroxylamine antioxidants include N, N-dilaurylhydroxyamine, N, N-dimyristylhydroxyamine, N, N-dipalmitylhydroxylamine, N-palmityl-N-stearylhydroxylamine, N , N-distearylhydroxylamine, N, N-dicocohydroxylamine, N, N-bishydroxylamine, and the like can be selected as appropriate and used alone or in combination of two or more. Can be used.

(Neutralizer)
The neutralizer is for dispersing the antioxidant in the resin, or for obtaining a lubricant function and a neutralization function for the polymerization reaction catalyst.

  Examples of neutralizing agents include calcium stearate, lithium stearate, sodium stearate, magnesium stearate, zinc stearate, calcium montanate, calcium 12-hydroxystearate, calcium stearyl lactate, 2,2-methylenebisphosphate (2,6 -Di-t-butylphenyl), magnesium, aluminum, hydroxide, carbonate, hydrate, etc., and these may be appropriately selected and used alone or in admixture of two or more. Can do.

  These additives are used in appropriate amounts depending on the properties required for the mold, but if the total content of these additives is in the range of 500 to 2000 ppm, the moldability and polymerization of the mold are increased. It is preferable that good results can be obtained in any of the properties, detachability, and specifications, and any of moldability, polymerizability, detachability, and specifications of the mold is particularly preferable in the range of 1000 to 1700 ppm. Even more favorable results can be obtained. When the total content of additives is less than 500 ppm, good results cannot be obtained in the measurement of interference fringes on the lens-forming optical surfaces of contact lenses that are molded products and ophthalmic lenses such as intraocular lenses. Sexuality gets worse.

On the other hand, if the total content of additives exceeds 2000 ppm, when the lens material is released from the mold after polymerization, peeling or breakage occurs on the lens surface, resulting in poor release properties.
This mold can be performed by a conventionally known method. For example, polypropylene is melted and an appropriate amount of the above-mentioned additive is mixed, and the mold is formed in a mold for mold production via an injection molding machine. By being injected, a mold having a target shape is formed.

(Lens material)
The monomer composition filled in the molding cavity of the mold includes at least a silicone-containing unsaturated monomer so that a lens material such as a contact lens having a high oxygen permeability (high oxygen permeability) can be obtained. It is necessary to be out.

  Examples of the silicone-containing unsaturated monomer include polysiloxane macromonomer, silicon-containing alkyl (meth) acrylate, and silicon-containing styrene derivative.

  More specifically, the polysiloxane macromonomer is a polymerizable unsaturated monomer represented by the following general formula (I) in which a polymerizable group is bonded to the siloxane main chain via one or more urethane bonds. is there.

A ¹ -U ¹ -(-S ¹ -U ^2- ) _n -S ² -U ³ -A ² (I)
In the general formula (I), A ¹ is a group represented by the following general formula (II).

^{Y 21 -Z 21 -R 31 - ......} (II)
[In General Formula (II), Y ²¹ represents an acryloyl group, a vinyl group, or an allyl group, Z ²¹ represents an oxygen atom or a direct bond, and R ³¹ represents a direct bond or a carbon number of 1 to Represents an alkylene group having 12 linear, branched or aromatic rings; ]
In the general formula (I), A ² is a group represented by the following general formula (III).

-R ³⁴ -Z ²² -Y ²² (III)
[In General Formula (III), Y ²² represents an acryloyl group, a vinyl group, or an allyl group, while Z ²² represents an oxygen atom or a direct bond, and R ³⁴ represents a direct bond or a carbon number of 1 to Represents an alkylene group having 12 linear, branched or aromatic rings. (However, Y ²¹ in the general formula (II) and Y ^{22 in the} general formula (III) may be the same or different.)]
Further, in the general formula (I), U ¹ is a group represented by the following general formula (IV).

-X ²¹ -E ²¹ -X ²⁵ -R ^32- (IV)
[In General Formula (IV), X ²¹ and X ²⁵ each independently represent a direct bond, an oxygen atom or an alkylene glycol group, and E ²¹ represents an —NHCO— group (in this case, X ²¹ represents X ²⁵ is an oxygen atom or an alkylene glycol group, E ²¹ forms a urethane bond with X ²⁵ ), —CONH— group (in this case, X ²¹ is , An oxygen atom or an alkylene glycol group, while X ²⁵ is a direct bond, E ²¹ forms a urethane bond with X ²¹ ), or saturated or unsaturated aliphatic, alicyclic and aromatic A divalent group derived from a diisocyanate selected from the group of group (in this case, X ²¹ and X ²⁵ are each independently an oxygen atom or an alkylene glycol group; E ²¹ is X ²¹ and X ²¹ two forms a urethane bond between the ²⁵ Representing the-yl). R ³² represents an alkylene group having a linear or branched chain having 1 to 6 carbon atoms. ]
In the general formula (I), S ¹ and S ² are each independently a group represented by the following general formula (V).

［一般式（Ｖ）中、Ｒ²³、Ｒ²⁴、Ｒ²⁵、Ｒ²⁶、Ｒ²⁷、及びＲ²⁸は、それぞれ独立して、炭素数１〜６のアルキル基、フッ素置換されたアルキル基又はフェニル基であり、Ｋは１〜１５００の整数、Ｌは０又は１〜１４９９の整数であり、Ｋ＋Ｌは１〜１５００の整数である。］
さらに、前記した一般式（Ｉ）において、Ｕ²は、下記一般式（VI）にて表わされる基である。

[In General Formula (V), R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ , and R ²⁸ are each independently an alkyl group having 1 to 6 carbon atoms, a fluorine-substituted alkyl group, or phenyl. K is an integer of 1 to 1500, L is 0 or an integer of 1 to 1499, and K + L is an integer of 1 to 1500. ]
Furthermore, in the above general formula (I), U ² is a group represented by the following general formula (VI).

^{-R 37 -X 27 -E 24 -X 28} -R 38 - ...... (VI)
[In General Formula (VI), R ³⁷ and R ³⁸ each independently represents an alkylene group having a linear or branched chain having 1 to 6 carbon atoms, and X ²⁷ and X ²⁸ each independently represent Represents an oxygen atom or an alkylene glycol group. E ²⁴ is a divalent group derived from a diisocyanate selected from the group consisting of saturated or unsaturated aliphatic, alicyclic and aromatic groups (in this case, E ²⁴ represents X ²⁷ and X ^28). Forming two urethane bonds between each other). ]
In the above general formula (I), U ³ is a group represented by the following general formula (VII).

^{-R 33 -X 26 -E 22 -X 22} - ...... (VII)
[In General Formula (VII), R ³³ represents an alkylene group having a linear or branched chain having 1 to 6 carbon atoms, and X ²² and X ²⁶ are each independently a direct bond, an oxygen atom or an alkylene group. Represents a glycol group. E ²² is a —NHCO— group (wherein X ²² is an oxygen atom or an alkylene glycol group, while X ²⁶ is a direct bond, and E ²² forms a urethane bond with X ^26. are), - CONH- group (provided that in this case, X ^22, while a direct bond, X ²⁶ is an oxygen atom or an alkylene glycol group, E ²² forms a urethane bond and X ²⁶ Or a divalent group derived from a diisocyanate selected from the group consisting of saturated or unsaturated aliphatic, alicyclic and aromatic groups (wherein X ²² and X ²⁶ are each independently An oxygen atom or an alkylene glycol group, and E ²² represents two urethane bonds between X ²² and X ²⁶ ). ]
In addition, in the said general formula (I), n shows 0 or the integer of 1-10.

  On the other hand, specific examples of the silicon-containing (meth) acrylate which is one of the silicone-containing unsaturated monomers include, for example, trimethylsiloxydimethylsilylmethyl (meth) acrylate, trimethylsiloxydimethylsilylpropyl (meth) acrylate, methylbis (trimethylsiloxy) ) Silylpropyl (meth) acrylate, tris (trimethylsiloxy) silylpropyl (meth) acrylate, mono [methylbis (trimethylsiloxy) siloxy] bis (trimethylsiloxy) silylpropyl (meth) acrylate, tris [methylbis (trimethylsiloxy) siloxy] Silylpropyl (meth) acrylate, methylbis (trimethylsiloxy) silylpropylglyceryl (meth) acrylate, tris (trimethylsiloxy) silyl Propylglyceryl (meth) acrylate, mono [methylbis (trimethylsiloxy) siloxy] bis (trimethylsiloxy) silylpropylglyceryl (meth) acrylate, trimethylsilylethyltetramethyldisiloxypropylglyceryl (meth) acrylate, trimethylsilylmethyl (meth) acrylate, Trimethylsilylpropyl (meth) acrylate, trimethylsilylpropylglyceryl (meth) acrylate, trimethylsiloxydimethylsilylpropylglyceryl (meth) acrylate, methylbis (trimethylsiloxy) silylethyltetramethyldisiloxymethyl (meth) acrylate, tetramethyltriisopropylcyclotetrasiloxy Sanylpropyl (meth) acrylate, tetramethyltriisopropyl Black tetra siloxy bis (trimethylsiloxy) can be exemplified silyl propyl (meth) acrylate. In the present specification, “·· (meth) acrylate” means “·· acrylate” or “·· methacrylate”.

  On the other hand, examples of the silicon-containing styrene derivative that is another silicone-containing unsaturated monomer include those represented by the following general formula (VIII).

［式中、ｐは１〜１５の整数、ｑは０又は１、ｒは１〜１５の整数を示す。］
なお、上記の一般式（VIII）にて表わされるシリコン含有スチレン誘導体において、ｐ又はｒが、１６以上の整数である場合には、その精製や合成が困難となると共に、得られるレンズ材料の硬度が低下するようになる。又、ｑが、２以上の整数である場合には、シリコン含有スチレン誘導体の合成が困難となる傾向がある。

[Wherein, p represents an integer of 1 to 15, q represents 0 or 1, and r represents an integer of 1 to 15. ]
In the silicon-containing styrene derivative represented by the above general formula (VIII), when p or r is an integer of 16 or more, purification and synthesis are difficult, and the hardness of the obtained lens material Will fall. In addition, when q is an integer of 2 or more, synthesis of the silicon-containing styrene derivative tends to be difficult.

  Specific examples of the silicon-containing styrene derivative represented by the general formula (VIII) include, for example, tris (trimethylsiloxy) silylstyrene, bis (trimethylsiloxy) methylsilylstyrene, (trimethylsiloxy) dimethylsilylstyrene, tris (Trimethylsiloxy) siloxydimethylsilylstyrene, [bis (trimethylsiloxy) methylsiloxy] dimethylsilylstyrene, heptamethyltrisiloxanylstyrene, nonamethyltetrasiloxanylstyrene, pentadecamethylheptacyloxanylstyrene, heneicosa Methyl decayloxanyl styrene, heptacosamethyl tridecacyloxanyl styrene, Hentria Contamethyl pentadecacloxanyl styrene, Trimethylsiloxypentamethyldisiloxymethyl Styrene, tris (pentamethyldisiloxy) silylstyrene, tris (trimethylsiloxy) siloxybis (trimethylsiloxy) silylstyrene, bis (heptamethyltrisiloxy) methylsilylstyrene, tris [methylbis (trimethylsiloxy) siloxy] silylstyrene, trimethylsiloxy Bis [tris (trimethylsiloxy) siloxy] silylstyrene, heptakis (trimethylsiloxy) trisilylstyrene, nonamethyltetrasiloxyundecylmethylpentasiloxymethylsilylstyrene, tris [tris (trimethylsiloxy) siloxy] silylstyrene, (tristrimethylsiloxy Hexamethyl) tetrasiloxy [tris (trimethylsiloxy) siloxy] trimethylsiloxysilylstyrene, nonakis Methylsiloxy) tetrasilylstyrene, bis (tridecamethylhexasiloxy) methylsilylstyrene, heptamethylcyclotetrasiloxynylstyrene, heptamethylcyclotetrasiloxybis (trimethylsiloxy) silylstyrene, tripropyltetramethylcyclotetrasiloxanyl Examples thereof include styrene and trimethylsilylstyrene.

Moreover, it is preferable to contain the nitrogen-containing unsaturated monomer in addition to the silicone-containing unsaturated monomer.
As the nitrogen-containing unsaturated monomer, N-vinyl lactam, N-mono or N, N-disubstituted (meth) acrylamide that is nonionic and can improve the water content of the obtained contact lens. Can be suitably employed. In the present specification, the notation “·· (meth) acrylamide” is used as a general term including “·· acrylamide” and “·· methacrylamide”.

  More specifically, examples of N-vinyl lactams include N-vinyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone, N-vinyl-4-methyl-2-pyrrolidone, and N-vinyl. -5-methyl-2-pyrrolidone, N-vinyl-3-ethyl-2-pyrrolidone, N-vinyl-4,5-dimethyl-2-pyrrolidone, N-vinyl-5,5-dimethyl-2-pyrrolidone, N -Pyrrolidone such as vinyl-3,3,5-trimethyl-2-pyrrolidone, N-vinyl-5-methyl-5-ethyl-2-pyrrolidone; N-vinyl-2-piperidone, N-vinyl-3-methyl- 2-piperidone, N-vinyl-4-methyl-2-piperidone, N-vinyl-5-methyl-2-piperidone, N-vinyl-6-methyl-2-piperidone, N-vinyl-6-ethyl-2- Piperidones such as peridone, N-vinyl-3,5-dimethyl-2-piperidone, N-vinyl-4,4-dimethyl-2-piperidone; N-vinyl-2-caprolactam, N-vinyl-3-methyl-2 -Caprolactam, N-vinyl-4-methyl-2-caprolactam, N-vinyl-7-methyl-2-caprolactam, N-vinyl-7-ethyl-2-caprolactam, N-vinyl-3,5-dimethyl-2 -Caprolactam, N-vinyl-4,6-dimethyl-2-caprolactam, caprolactam such as N-vinyl-3,5,7-trimethyl-2-caprolactam; methacryloylmorpholine and the like, while N-mono or N, Examples of the N-disubstituted (meth) acrylamide include N-methyl (meth) acrylamide and N-ethyl (meth). N-monosubstituted (meth) acrylamides such as N-monoalkyl (meth) acrylamides such as chloramide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide; N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-methyl (ethyl) (meth) acrylamide, N, N-methyl (propyl) (meth) acrylamide, N, N-ethyl ( N, N-dialkyl (meth) acrylamides such as (propyl) (meth) acrylamide, and N, N-disubstituted (meth) acrylamides such as N, N-dimethylaminopropyl (meth) acrylamide, and these nitrogen-containing An unsaturated monomer is appropriately selected, and a single monomer or a mixture of two or more Used.

  The nitrogen-containing unsaturated monomer is contained in an amount of 2% by weight or more, preferably 4% by weight or more, based on the total amount of polymerizable unsaturated monomer components constituting the monomer composition to be polymerized. It is desirable to be squeezed.

  In addition, a polymerizable unsaturated monomer different from the above-mentioned silicone-containing unsaturated monomer is appropriately selected as the monomer composition in accordance with the characteristics required for the lens material (for example, contact lens). And may be contained in an appropriate amount.

  Examples of such polymerizable unsaturated monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, and dodecyl. Alkyl (meth) acrylates such as (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, hexafluoroisopropyl (meth) acrylate; hydroxyethyl (meth) acrylate, hydroxy Hydroxyl-containing (meth) acrylates such as propyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, (meth) acrylic acid, and the like In addition to polymerizable unsaturated monomers conventionally used as raw materials for lens materials such as silicone-containing unsaturated monomers, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) Polyethylene glycol di (meth) acrylate such as acrylate; Polypropylene glycol di (meth) acrylate such as propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate; Hexamethylene glycol di (Meth) acrylate, trimethylolpropane tri (meth) acrylate, vinyl (meth) acrylate, allyl (meth) acrylate, (meth) acryloyloxyethyl (meth) ) Acrylate, N, N'-methylenebis (meth) acrylamide, N, N'-dihydroxy ethylene - bis (meth) acrylamide and the like, can be exemplified polyfunctional monomer used as a crosslinking agent conventionally.

  Furthermore, in the monomer composition containing the silicone-containing unsaturated monomer, in addition to the polymerizable unsaturated monomer, various conventionally known polymerization initiators, for example, thermal polymerization initiators, photopolymerization initiators, Each is added in an appropriate amount.

  Examples of the polymerization initiator include radical polymerization initiators such as azobisisobutyronitrile, azobisdimethylvaleronitrile, benzoyl peroxide, tert-butyl hydroperoxide, cumene hydroberoxide, methyl orthobenzoyl benzoate, and methyl benzoylform. Benzoin photopolymerization initiators such as mate, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin-n-butyl ether; 2-hydroxy-2-methyl-1-phenylpropan-1-one, p -Isopropyl-α-hydroxyisobutylphenone, p-tert-butyltrichloroacetophenone, 2,2-dimethoxy-2-phenylacetophenone, α, α-dichloro-4- Phenone photopolymerization initiators such as enoxyacetophenone and N, N-tetraethyl-4,4-diaminobenzophenone; 1-hydroxycyclohexyl phenyl ketone; 1-phenyl-1,2-propanedione-2- (o-ethoxy) Carbonyl) oxime; thioxanthone photopolymerization initiators such as 2-chlorothioxanthone and 2-methylthioxanthone; dibenzosubalon; 2-ethylanthraquinone; benzophenone acrylate; benzophenone; These are appropriately selected depending on the polymerization method and the like, and are used alone or in admixture of two or more.

The characteristics of the mold polymerization mold configured as described above will be described.
(1) According to the mold polymerization mold of the present embodiment, the part that gives the molding cavity is made of polypropylene having a total content of additives in the range of 500 to 2000 ppm. The lens material molded using the molding die is excellent in moldability and can be made suitable for polymerizability, detachability and specifications.

  (2) Especially when the additive is an antioxidant and a neutralizing agent, the lens material molded using a mold for mold polymerization is excellent in moldability and suitable for polymerizability, detachability and standard. Can be made.

Next, Examples 1 to 5 and Comparative Examples 1 to 3 will be described with reference to Tables 1 to 3.
The mold polymerization molds of Examples 1 to 5 and Comparative Examples 1 to 3 (that is, male mold and female mold) were molten polypropylenes in which the addition ratio of additives (that is, antioxidant and neutralizer) was changed. These are formed by injecting them into a molding cavity formed in a mold for manufacturing a mold by an injection molding machine.

  Here, in Examples 1 to 5 and Comparative Examples 2 and 3, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane used as the antioxidant and Tables 1 and 2 show the total proportion of tris (2,4-di-t-butylphenyl) phosphite. In Examples 1 to 5 and Comparative Examples 2 and 3, calcium stearate was used as the neutralizing agent in the proportions shown in Tables 1 and 2.

  As shown in Tables 1 and 2, in Example 1, antioxidant 400 ppm, neutralizer 1000 ppm, Example 2 antioxidant 500 ppm, neutralizer 500 ppm, Example 3 antioxidant 600 ppm, medium In the fourth embodiment, the sum is 500 ppm, and in Example 4, the antioxidant is 1000 ppm, the neutralizer is 700 ppm, and in Example 5, the antioxidant is 600 ppm, and the neutralizer is 500 ppm.

又、比較例１では、酸化防止剤０ｐｐｍ、中和剤０ｐｐｍ、比較例２では酸化防止剤１０００ｐｐｍ、中和剤１３００ｐｐｍ、比較例３では酸化防止剤１０００ｐｐｍ、中和剤１３００ｐｐｍとしている。

In Comparative Example 1, the antioxidant is 0 ppm and the neutralizing agent is 0 ppm. In Comparative Example 2, the antioxidant is 1000 ppm and the neutralizing agent is 1300 ppm. In Comparative Example 3, the antioxidant is 1000 ppm and the neutralizing agent is 1300 ppm.

  Then, using the mold polymerization molds of Examples 1 to 5 and Comparative Examples 1 to 3, a lens material made of the material 1 or the material 2 (in this example and the comparative example, a contact lens) Material 2 was polymerized and molded by a thermal polymerization method using a polymerization oven by a UV polymerization method using a UV lamp.

  Here, the material 1 and the material 2 are shown in Table 3.

表３中の、略号は以下の通りである。

Abbreviations in Table 3 are as follows.

(monomer)
Silicone-containing unsaturated monomer A: Urethane bond-containing polydimethylsiloxane macromonomer Silicone-containing unsaturated monomer B: Tris (trimethylsiloxy) silylisopropyl methacrylate 6FPMA: Hexafluoroisopropyl methacrylate N-MMP: 1-methyl-3-methylene-2- Pyrrolidinone DMAA: N, N-dimethylacrylamide N-VP: N-vinyl-2-pyrrolidone MAA: Methacrylic acid EDMA: Ethylene glycol dimethacrylate (polymerization initiator)
HMPPO: 2-hydroxy-2-methyl-1-phenylpropan-1-one V-65: Azobisdimethylvaleronitrile And, using the respective molds of Examples 1-5 and Comparative Examples 1-3, The moldability, polymerizability, detachability, and specifications when the lens material was molded were evaluated.

The evaluation items are as follows.
1. Moldability Interference fringes were measured on the lens-forming optical surface of the molded product, and the quality was judged.

<Evaluation criteria>
○: The roundness of the interference fringes is less than 0.02 mm.
(Triangle | delta): The roundness of an interference fringe is less than 0.03 mm.

X: The roundness of interference fringes is 0.03 mm or more.
2. Polymerization Polymerization was performed using molds for mold polymerization that were suitable for the items of moldability, and the polymerizability (surface characteristics / residual monomers) was evaluated.

<Evaluation criteria>
○: No abnormality on the lens surface and residual monomer.
X: Abnormality on the surface (demolded, unpolymerized) and residual monomer.
3. Removability Using a mold polymerization mold that was suitable for the item of moldability, the releasability of the lens polymer after polymerization from the mold was evaluated.

<Evaluation criteria>
○: No abnormality on the lens surface.
X: There is peeling or damage on the lens surface.
4). Standards Using molds for mold polymerization that were qualified for moldability, the polymerized lens polymer was released from the mold, and the resulting lens standards (BC, Power, Corona) were evaluated. went.

<Evaluation criteria>
○: Corona state is B. C. More than level.
X: Corona defect.

-: Not carried out because no lens was obtained.
As shown in Table 1 and Table 2, in Examples 1 to 5, since the total content of antioxidants is 1000 to 1700 ppm, all items of moldability, polymerizability, detachability, and specifications are: We were able to get an evaluation of On the other hand, in the case of Comparative Example 1 in which the antioxidant was 0 ppm, the evaluation of moldability was x, and there was no value as a product, so other evaluation items were not carried out. Further, in Comparative Examples 2 and 3 where the antioxidant was 2300 ppm, peeling and breakage occurred on the lens surface, the detachability was evaluated as x, and the standard evaluation items were not carried out.

In addition, embodiment of this invention is not limited to the said embodiment, You may change a structure as follows.
In the above embodiment, a contact lens is taken as an example, but it goes without saying that the embodiment may be embodied in a mold for mold polymerization that forms another ophthalmic lens such as an intraocular lens.

Claims (2)

  A monomer composition containing at least a silicone-containing unsaturated monomer is accommodated in a molding cavity and polymerized to form a molding die for molding a target ophthalmic lens material, and at least a portion that provides the molding cavity Is composed of polypropylene having a total content of additives in the range of 500 to 2000 ppm.   The mold for mold polymerization according to claim 1, wherein the additives contained in the polypropylene are an antioxidant and a neutralizing agent.