JP5764925B2 - Method for producing silicone prepolymer - Google Patents

Description

  The present invention relates to a silicone prepolymer having a uniform composition. The silicone prepolymer exhibits a high Strehl ratio and has a small optical distortion, and thus is suitably used for an optical material. Furthermore, since it contains a silicone component and exhibits high oxygen permeability, it is particularly suitably used for intraocular lenses, artificial corneas, contact lenses and the like.

  Conventionally, there is an advantage that shrinkage at the time of polymerization can be suppressed and an extraction step of residual monomer is unnecessary after polymerization. Therefore, a method using a prepolymer having a polymerizable group is known in the polymerization of contact lenses. (For example, Patent Document 1). This Patent Document 1 mainly describes poly (2-hydroxyethyl methacrylate) which is a hydrophilic prepolymer, and the prepolymer is soluble in a water-soluble solvent.

  On the other hand, in order to obtain a material for contact lenses used for continuous wear, a method of copolymerizing a silicone monomer is known in order to obtain sufficient oxygen permeability. Various monomers are exemplified. However, Patent Document 1 does not specify a polymerization composition and a polymerization method when a silicone monomer is copolymerized. Therefore, for example, when a (meth) acrylic acid ester monomer is copolymerized as a silicone monomer and a (meth) acrylamide monomer is used as a hydrophilic monomer, due to the difference in the polymerizability of these monomers, the initial and late polymerizations may occur. The composition of the resulting copolymer is different, and as a result, there is a problem in that optical distortion is observed when the polymer obtained by prepolymerizing the copolymer and polymerizing the copolymer is used as an optical material.

  In addition, as a method for copolymerizing at the same polymerization rate of two or more types of monomers having different polymerizability, a method in which a monomer is added dropwise is known (for example, Patent Document 2). In Patent Document 2, a solution containing a large amount of a (meth) acrylic acid ester monomer such as a silicone monomer is dropped into a solution containing a large amount of a (meth) acrylamide monomer that is a hydrophilic monomer, so that the polymerization rate can be made uniform. Polymerized. However, when the copolymer is obtained by copolymerization by the method of Patent Document 2, there is a problem that the uniformity of the polymerization rate and the reproducibility of the molecular weight of the obtained copolymer are low. In Patent Document 2, the molecular weight is controlled by chain transfer to the polymerization solvent, but it is presumed that the polymerization solvent is likely to volatilize and the composition changes during the polymerization. Furthermore, Patent Document 2 has a problem that it is difficult to confirm the degree of uniformity and reproducibility because there is no clear index regarding the uniformity of the polymerization rate.

International Publication No. 2003/077772 Pamphlet US Patent Application Publication No. 2009/0111905

  An object of this invention is to provide the prepolymer which has a uniform composition by superposing | polymerizing at the same polymerization rate of the monomer which has a different polymerizable functional group. More preferably, a silicone prepolymer having improved reproducibility of molecular weight and polymerization rate uniformity is provided by using a combination of a solvent that hardly causes chain transfer and a chain transfer agent, and introducing an index indicating the uniformity of polymerization. Since the polymer obtained by polymerizing the prepolymer of the present invention has a good Strehl ratio, it is particularly suitable as a raw material for ophthalmic lenses such as contact lenses, intraocular lenses, and artificial corneas.

(1) A group consisting of a monomer having any one of a styryl group, an acryloyloxy group, and a methacryloyloxy group,
A group consisting of monomers having any one of an acrylamide group, a methacrylamide group, a vinyl carbonate group, a vinyl carbamate group, a vinyl amide group, and a vinyl ester group is defined as B group,
In the case of selecting and copolymerizing at least one monomer from each of Group A and Group B,
Among the monomers divided into two groups, group A and group B, at least one monomer is a silicone monomer, and at least one monomer is a hydrophilic monomer, and at least one monomer is a hydroxyl group in the molecule , A monomer having at least one reactive functional group selected from an amino group, a carboxyl group and a carboxylic anhydride group ;
And, A group, in the monomer a and monomer b which their respective selected from Group B,
When the average value of the monomer consumption rate (%) difference between the monomer a and the monomer b from the start of polymerization to the end of polymerization is the ABC value,
A method for producing a silicone prepolymer, wherein the polymerization is carried out so that the ABC value is 7.15 or less.
(2) A dripping liquid and a dripping liquid each containing the silicone monomer, the hydrophilic monomer and the reactive monomer,
S _{A1 is} the sum of the molar concentrations of the monomers contained in the group A in the dripping solution, and S _{B1 is} the sum of the molar concentrations of the monomers contained in the group _{B in} the dripping solution. S _{A2 is} the sum of the molar concentrations of the monomers, and S _B2 is the sum of the molar concentrations of the monomers contained in group B in the dropping solution.
S _A1 / S _B1 <S _A2 / S _B2
Using a dripping liquid and a dripping liquid that satisfy
The method for producing a prepolymer as described in (1) above, wherein polymerization is carried out while continuously or intermittently adding the dropping solution to the dropping solution.
(3) The monomer according to (1) or (2) above, wherein the monomer selected from Group A has a (meth) acryloyloxy group, and the monomer selected from Group B has a (meth) acrylamide group A method for producing a prepolymer.
(4) The method for producing a prepolymer according to any one of the above (1) to (3), wherein the total content of silicon atoms is 10 to 30% by weight based on the solid content of the prepolymer.
(5) At least one of the silicone monomers is a polar silicone monomer having a polar group in the molecule, and the content of the polar silicone monomer is 30 to 90% by weight with respect to the solid content of the silicone prepolymer. The method for producing a prepolymer as described in (4) above, wherein
(6) The polar group is a hydroxyl group, amide group, carboxyl group, amino group, carbonate group, carbamate group, sulfonamide group, sulfonic acid group, phosphoric acid group, methoxyethyl group, methoxyethoxyethyl group, hydroxyethyl group, hydroxy The method for producing a prepolymer as described in (5) above, which is a group selected from the group consisting of ethoxyethyl groups.
(7) The method for producing a prepolymer according to (5), wherein the polar group is a hydroxyl group.
(8) At least one of the polar silicone monomers is represented by the following general formula (d)

The method for producing a prepolymer according to (5), wherein the monomer is represented by the formula:
(In formula (d), R represents hydrogen or a methyl group. L represents an alkylene group having 1 to 20 carbon atoms or an arylene group. D represents a silicone group.)
(9) At least one of the polar silicone monomers is represented by the following general formula (e)

The method for producing a prepolymer according to (5), wherein the monomer is represented by the formula:
(In the formula (e), R represents hydrogen or a methyl group. L represents an alkylene group or an arylene group having 1 to 20 carbon atoms. G represents an alkyl group or aryl having 1 to 20 carbon atoms and having 1 to 20 carbon atoms. Represents a group, D represents a silicone group.)
(10) D in the general formula (d) and / or (e) is the following general formula (f)

The method for producing a prepolymer as described in (8) or (9) above, wherein
(In formula (f), E ^{1 to} E ¹¹ are each independently hydrogen, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms. H represents an integer of 0 to 200, and i, j, and k each independently represents an integer of 0 to 20, except when h = i = j = k = 0.
(11) At least one of the polar silicone monomers is represented by the following general formula (s)

The method for producing a prepolymer according to (5), wherein the monomer is represented by the formula:
(In the formula (s), n represents an integer of 3 to 10. R _s represents an alkyl group or an aryl group having 1 to 20 carbon atoms.)
(12) The hydrophilic monomer is N, N-dimethylacrylamide, 2-hydroxyethyl methacrylate, N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, (meth) acrylic acid, N-vinyl-2-piperidone, N-vinyl-2-caprolactam, N-vinyl-3-methyl-2-caprolactam, N-vinyl-3-methyl-2-piperidone, N-vinyl-4-methyl-2-piperidone, N-vinyl-4- Methyl-2-caprolactam, N-vinyl-3-ethyl-2-pyrrolidone, N-vinyl-4,5-dimethyl-2-pyrrolidone, N-vinylimidazole, acryloylmorpholine, N, N-diethylacrylamide, N-isopropyl The monomer selected from the group consisting of acrylamide; (1) The manufacturing method of the prepolymer in any one of (11).
(13) The method for producing a prepolymer according to any one of (1) to (12) above, wherein a solvent having a boiling point of 80 ° C. to 200 ° C. at 1013 hPa is used as the polymerization solvent.
(14) A method for producing a prepolymer as described in any one of (1) to (13) above, wherein a tertiary alcohol is used as a polymerization solvent.
(15) After polymerization, it is obtained by introducing a polymerizable functional group by reacting a reactive functional group derived from a monomer having at least one reactive functional group in the molecule with a compound having a polymerizable functional group. The method for producing a prepolymer as described in any one of (1) to (14) above.
(16) The method for producing a prepolymer as described in (2) above, wherein a chain transfer agent is contained in the liquid to be dropped and / or in the liquid to be dropped.
(17) The method for producing a prepolymer according to the above (17), wherein the chain transfer agent is an alkyl mercaptan.
(18) An ophthalmic lens obtained by polymerizing a prepolymer obtained by the production method according to any one of (1) to (18).
(19) A contact lens obtained by polymerizing a prepolymer obtained by the production method according to any one of (1) to (18).

  By the production method of the present invention, a prepolymer having a uniform composition can be obtained by performing polymerization at the same polymerization rate of monomers having different polymerizable functional groups. Since the polymer obtained by polymerizing the prepolymer of the present invention has a good Strehl ratio, it is suitably used as a raw material for ophthalmic lenses such as contact lenses, intraocular lenses, and artificial corneas.

It is an example of the graph which plotted the monomer consumption rate of the monomer a and the monomer b with respect to polymerization time.

  In the method for producing a silicone prepolymer of the present invention, a silicone prepolymer having a uniform composition can be obtained by performing polymerization at the same polymerization rate of monomers having different polymerizable functional groups.

  In the method for producing a silicone prepolymer of the present invention, monomers used for copolymerization are roughly divided into two groups depending on the polymerization rate at the time of copolymerization. Monomers having any of styryl, acryloyloxy, and methacryloyloxy groups that polymerize faster during copolymerization, acrylamide groups, methacrylamide groups, vinyl carbonate groups, vinyl carbamate groups that tend to polymerize more slowly, Monomers having either a vinylamide group or a vinyl ester group are group B. Among these, the monomers of group A are preferably (meth) acryloyloxy groups, B in terms of balance of physical properties of transparency, elastic modulus, and moisture content when the obtained silicone prepolymer is polymerized and used as an optical material. A group of monomers is a combination of (meth) acrylamide groups, and most preferably, a group A monomer is a methacryloyloxy group, and a group B monomer is a combination of acrylamide groups.

  In the method for producing a silicone prepolymer of the present invention, in each of monomer a and monomer b selected from Group A and Group B, the monomer consumption of each of monomer a and monomer b from the start of polymerization to the end of polymerization Let the average value of the difference of rate (%) be ABC value.

  The smaller the ABC value, the better the polymerization rate of the monomer a selected from the group A and the polymerization rate of the monomer b selected from the group B match from the start of polymerization to the end of polymerization. When both monomers are sufficiently uniformly polymerized, the ABC value is 7.15 or less, and the uniformity of the composition of the silicone polymer obtained by polymerizing the obtained silicone prepolymer is improved, so a wider range. More preferably, it is 6.21 or less from the viewpoint that a transparent silicone polymer can be easily obtained with the above composition, and it is possible to suppress adhesion of lipids and the like to the polymer surface because the surface uniformity of the silicone polymer is improved. Most preferably, it is 5 or less.

  Of the monomers used in the method for producing a silicone prepolymer of the present invention, at least one monomer is a silicone monomer. Moreover, in order that the obtained silicone prepolymer becomes easy to melt | dissolve in an aqueous solvent, it is preferable that at least 1 type of silicone monomer is a polar silicone monomer which has a polar group in a molecule | numerator. The content is preferably 30 to 90% by weight with respect to the solid content of the silicone prepolymer because the solubility in an aqueous solvent cannot be obtained if the content is too small or too large. More preferred is 50 to 70% by weight.

Suitable examples of polar groups in the polar silicone monomer include hydroxyl group, amide group, carboxyl group, amino group, carbonate group, carbamate group, sulfonamide group, sulfonic acid group, phosphoric acid group, methoxyethyl group, methoxyethoxyethyl group , Hydroxyethyl group, and hydroxyethoxyethyl group. Of these, the most preferred is a hydroxyl group.
More specifically, a preferred example of the polar silicone monomer is represented by the following general formula (d)

A silicone monomer represented by the following general formula (e)

A silicone monomer represented by the following general formula (s)

The silicone monomer represented by these is mentioned.

  In general formulas (d), (e), and (s), R represents hydrogen or a methyl group.

  In general formulas (d) and (e), L represents an alkylene group having 1 to 20 carbon atoms or an arylene group. Examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, an octylene group, a decylene group, and a phenylene group. The alkylene group and arylene group may be branched or linear.

  In general formulas (d) and (e), D represents a silicone group. As preferred examples thereof, the following general formula (f)

The silicone group represented by these is mentioned.

In general formula (f), E ^{1 to} E ¹¹ are each independently hydrogen, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms. Represents either.

  In general formula (f), h represents an integer of 0 to 200, and i, j, and k each independently represent an integer of 0 to 20 (provided that h = i = j = k = 0). except). If the sum of h + i + j + k is too small, sufficient oxygen permeability cannot be obtained, and if it is too large, the compatibility with the hydrophilic monomer is reduced, so 2-100 are preferred, 2-10 are more preferred, 3-8 Is most preferred. Moreover, i = j = k = 0 is preferable from the viewpoint of the shape recoverability of the polymer obtained by polymerizing the obtained silicone prepolymer.

  In general formula (e), G represents a C1-C20 alkyl group or aryl group having at least one hydroxyl group. Examples thereof include 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 2,3-dihydroxypropyl group and the like.

  In general formula (s), n represents an integer of 3 to 10, but if it is too small, sufficient oxygen permeability cannot be obtained, and if it is too large, the compatibility with the hydrophilic monomer is lowered. Is more preferable.

  In general formula (s), Rs represents a C1-C20 alkyl group or an aryl group. For example, methyl group, ethyl group, propyl group, n-propyl group, i-propyl group, n-butyl group, s-butyl group, t-butyl group, n-pentyl group, i-pentyl group, s- Examples include pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, icosyl group, phenyl group, naphthyl group and the like. The alkyl group may be branched or linear. When Rs has too many carbon atoms, the silicone content is relatively lowered and the oxygen permeability is lowered. Therefore, an alkyl group having 1 to 10 carbon atoms or an aryl group is more preferable, and an alkyl group having 1 to 4 carbon atoms is most preferable. preferable.

  If the silicon prepolymer obtained by the method for producing a silicone prepolymer of the present invention has a silicon atom content that is too low, a polymer obtained by polymerizing the silicone prepolymer cannot obtain sufficient oxygen permeability, and if it is too high, it is hydrophilic. 10-30% by weight is preferable with respect to the solid content of the prepolymer because compatibility with the polymerizable monomer cannot be obtained.

  Among the monomers used in the method for producing the silicone prepolymer of the present invention, at least one is a hydrophilic monomer. Preferred examples thereof include N, N-dimethylacrylamide, 2-hydroxyethyl methacrylate, N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, (meth) acrylic acid, N-vinyl-2-piperidone, N- Vinyl-2-caprolactam, N-vinyl-3-methyl-2-caprolactam, N-vinyl-3-methyl-2-piperidone, N-vinyl-4-methyl-2-piperidone, N-vinyl-4-methyl- 2-caprolactam, N-vinyl-3-ethyl-2-pyrrolidone, N-vinyl-4,5-dimethyl-2-pyrrolidone, N-vinylimidazole, acryloylmorpholine, N, N-diethylacrylamide, N-isopropylacrylamide, etc. Is mentioned. Of these, N, N-dimethylacrylamide is most preferable in terms of the balance between compatibility with the silicone monomer and hydrophilicity.

  Among the monomers used in the method for producing a silicone prepolymer of the present invention, at least one type is a monomer having a reactive functional group. Suitable examples thereof include hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dihydroxypropyl (meth) acrylate, hydroxyethyl (meth) ) Acrylamide, dihydroxypropyl (meth) acrylamide, hydroxymethyl (meth) acrylamide, hydroxypropyl (meth) acrylamide, diethylene glycol (meth) acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol (meth) acrylate, ( Mono) having a hydroxyl group such as erythritol (meth) acrylate, xylitol (meth) acrylate, sorbitol (meth) acrylate, and polyethylene glycol (meth) acrylate -Monomers having amino groups such as allylamine and 2-aminoethyl (meth) acrylamide, (meth) acrylic acid, vinyloxyacetic acid, allyloxyacetic acid, (meth) acrylic acid, crotonic acid, 2- (meth) acryloylpropanoic acid, Examples include monomers having a carboxyl group such as 3- (meth) acryloylbutanoic acid and 4-vinylbenzoic acid. Among them, a monomer having a hydroxyl group and a monomer having an amino group are preferable because of the high reactivity of the reactive functional group, and it is more preferable in that it is difficult to promote the decomposition of the silicone component because it is neutral. Is a monomer having a hydroxyl group.

  In the method for producing a silicone prepolymer of the present invention, as a method for adjusting the polymerization rate, the concentration of the monomer of group B having a slow reaction rate in the initial reaction solution is relatively high, and the monomer of group A is polymerized during the polymerization. It is preferable to perform polymerization while continuously or intermittently adding a dropping solution having a relatively high concentration of.

That is, a dripping liquid and a dripping liquid each containing the silicone monomer, the hydrophilic monomer and the reactive monomer,
S _{A1 is} the sum of the molar concentrations of the monomers contained in the group A in the dripping solution, and S _{B1 is} the sum of the molar concentrations of the monomers contained in the group _{B in} the dripping solution. total _{S A2} molar concentration of the monomer, the sum of the molar concentrations of monomers contained in the group B of the drip solution when the _{S B2} to the following formula _{S A1 / S B1 <S A2} / S B2
Using a dripping liquid and a dripping liquid that satisfy
It is preferable to polymerize the dropping liquid while continuously or intermittently adding the dropping liquid during the polymerization.

  The dropping time in the case of dropping the monomer mixed solution should be determined according to the monomer used while measuring the ABC value under a plurality of dropping time conditions. In the case where the monomer of group B is an acrylamide, when the dropping time is too short, unpolymerized monomers gradually increase in the system, so that the polymerization rate difference becomes obvious and the ABC value increases, and the dropping time When it is too long, the production efficiency is lowered, so 200 to 600 minutes is preferable, 230 to 500 minutes is more preferable, and 250 to 450 minutes is most preferable.

  In the method for producing a silicone prepolymer of the present invention, the monomer consumption rate (%) at a certain point in time is obtained by dividing the amount of each monomer consumed up to that point by the amount of each monomer finally added to the polymerization stock solution. It is expressed as a value obtained by multiplying the obtained value by 100.

In the method for producing a silicone prepolymer of the present invention, the total difference between the monomer consumption rate of monomer a and the monomer consumption rate of monomer b at each measurement time from the start of polymerization to the end of polymerization is divided by the number of measurements, or the monomer A value obtained by dividing the area between two monomer consumption rate curves from the start of polymerization to the end of polymerization by the end of polymerization in the graph in which the monomer consumption rate of a and the monomer consumption rate of monomer b are plotted against the polymerization time is ABC. Define as value.
An example of a graph in which the monomer consumption rates of the monomer a and the monomer b used in the latter method are plotted against the polymerization time is shown in FIG. The ABC value is expressed as follows using a mathematical formula.
ABC value = (1 / T) ΣA _n
(T is the end of polymerization time, A _n represents an area between the graph in each section.)
However, the polymerization completion time is defined as the polymerization completion time when either the monomer consumption rate of the monomer a and the monomer b is 97% or more, or the shorter time of 720 minutes. In addition, when the polymerization end time is 720 minutes, the monomer consumption rate so as to include each measurement time of 0, 20, 40, 60, 80, 100, 120, 150, 180, 240, 300, 360, 720 minutes. Measure. When the polymerization end time is shorter than 720 minutes, the monomer consumption rate is measured at a point within the above measurement time within the polymerization end time.

  In the method for producing a silicone prepolymer of the present invention, when the silicone prepolymer is polymerized, a thermal polymerization initiator typified by a peroxide or an azo compound or a photopolymerization initiator is added to facilitate the polymerization. It is preferable. When performing thermal polymerization, a thermal polymerization initiator having an optimum decomposition characteristic for a desired reaction temperature is selected and used. In general, azo initiators and peroxide initiators having a 10-hour half-life temperature of 40 ° C to 120 ° C are suitable. Examples of the photopolymerization initiator include carbonyl compounds, peroxides, azo compounds, sulfur compounds, halogen compounds, and metal salts. These polymerization initiators are used alone or in combination. The amount used is appropriately adjusted according to the target molecular weight of the silicone prepolymer, but is preferably 0.001 to 5 mol%, more preferably 0.005 to 3 mol%, and more preferably 0.01 to 1 mol% with respect to the monomer. Most preferred.

  In the production method of the present invention, a chain transfer agent may be contained in the dropping liquid and / or in the dropping liquid in order to control the molecular weight of the resulting silicone prepolymer. Preferable examples of the chain transfer agent include alkyl mercaptans such as 2-mercaptoethanol, 2-aminoethanethiol, 2-aminoethanethiol hydrochloride, 1-hexanethiol, 1-dodecanethiol. The amount used is appropriately adjusted according to the target molecular weight of the silicone prepolymer, but is preferably 0.001 to 10 mol%, more preferably 0.005 to 5 mol%, and more preferably 0.01 to 3 mol based on the monomer. % Is most preferred.

  When the silicone prepolymer is polymerized by the method for producing a silicone prepolymer of the present invention, a polymerization solvent can be used. If the boiling point of the polymerization solvent is too low, the molecular weight of the silicone prepolymer obtained from volatilization during the polymerization and change in the monomer concentration is not stable, and if it is too high, removal after polymerization becomes difficult. The boiling point at 1013 hPa is preferably 80 ° C to 200 ° C, more preferably 90 ° C to 180 ° C. As the polymerization solvent, various organic and inorganic solvents are applicable. Examples include water, methanol, ethanol, propanol, 2-propanol, butanol, t-butanol, t-amyl alcohol, 3-methyl-3-pentanol, 3,7-dimethyl-3-octanol, tetrahydrolinalol and the like. Various alcohol solvents, various aromatic hydrocarbon solvents such as benzene, toluene, xylene, various aliphatic hydrocarbon solvents such as hexane, heptane, octane, decane, petroleum ether, kerosene, ligroin, paraffin, acetone, methyl ethyl ketone , Various ketone solvents such as methyl isobutyl ketone, various ester solvents such as ethyl acetate, butyl acetate, methyl benzoate, dioctyl phthalate, ethylene glycol diacetate, diethyl ether, tetrahydrofuran, dioxane, ethylene glycol Various glycol ethers such as rudialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polyethylene glycol-polypropylene glycol block copolymer, polyethylene glycol-polypropylene glycol random copolymer These are solvents, and these can be used alone or in combination. Among these, alcohol-based solvents are preferable because they easily dissolve both the silicone monomer and the hydrophilic monomer. In view of the advantage that chain transfer to the solvent is unlikely to occur during radical polymerization, it is combined with a chain transfer agent. By using it, it is possible to obtain a silicone prepolymer having the same molecular weight with good reproducibility, such as t-butanol, t-amyl alcohol, 3-methyl-3-pentanol, 3,7-dimethyl-3-octanol, etc. Tertiary alcohols are more preferable, and more preferable are t-butanol, t-amyl alcohol, and 3-methyl-3-pentanol, which are easy to remove after the polymerization reaction because the boiling point is not too high.

  If the molecular weight of the silicone prepolymer obtained by the production method of the present invention is too low, it is difficult to obtain an effect of reducing polymerization shrinkage, and if it is too high, the viscosity of the polymerization stock solution when polymerizing the silicone prepolymer to obtain a polymer becomes high. Therefore, 5,000 to 1,000,000 is preferable, 8,000 to 500,000 is more preferable, and 10,000 to 150,000 is most preferable.

  The silicone prepolymer obtained by the production method of the present invention is obtained by introducing a polymerizable functional group by reacting a compound having a polymerizable functional group with a reactive functional group of a monomer having a reactive functional group after polymerization. be able to. Preferable examples of the reactive functional group include a hydroxyl group, an amino group, a carboxyl group, an ester group, and a carboxylic anhydride group. Of these, a hydroxyl group is preferable in terms of reactivity and functional group neutrality. Moreover, as a suitable example in the case of using the compound which has a polymerizable functional group, (meth) acrylic acid 2-isocyanatoethyl, (meth) acrylic acid chloride, (meth) acrylic acid anhydride, 2-hydroxy methacrylate Examples include ethyl. Among these, (meth) acrylic anhydride and (meth) acrylic acid 2-isocyanatoethyl are preferable because they have high reactivity with the reactive functional group and can introduce the functional group with high efficiency.

  If the degree of functionalization of the silicone prepolymer obtained by the production method of the present invention is too high, the elastic modulus of the polymer obtained by polymerizing the silicone prepolymer will be too high, and if it is too low, the polymerization will not occur sufficiently and the polymer will not Since it is not obtained, it is preferably 0.1 to 1.5 mol%, more preferably 0.2 to 1 mol%, more preferably 0.25 to 0 with respect to the total number of moles of monomers used for the polymerization of the silicone prepolymer. .7 mol% is most preferred.

  When the silicone prepolymer obtained by the production method of the present invention is polymerized to obtain a silicone polymer, a thermal polymerization initiator typified by a peroxide or an azo compound or a photopolymerization initiator is used to facilitate the polymerization. It is preferable to add. When performing thermal polymerization, a thermal polymerization initiator having an optimum decomposition characteristic for a desired reaction temperature is selected and used. In general, azo initiators and peroxide initiators having a 10-hour half-life temperature of 40 ° C to 120 ° C are suitable. Examples of the photopolymerization initiator include carbonyl compounds, peroxides, azo compounds, sulfur compounds, halogen compounds, and metal salts. These polymerization initiators are used alone or in combination, and are used in an amount of up to about 1 part by weight per 100 parts by weight of the monomer component.

  When a silicone prepolymer obtained by the production method of the present invention is polymerized to obtain a silicone polymer, it is preferable to add a hydrophilic polymer as an internal wetting agent to the polymerization stock solution in order to impart water wettability to the polymer surface. Suitable examples of hydrophilic polymers include polyvinylpyrrolidone, poly-N-vinyl-2-piperidone, poly-N-vinyl-2-caprolactam, poly-N-vinyl-3-methyl-2-caprolactam, poly-N- Vinyl-3-methyl-2-piperidone, poly-N-vinyl-4-methyl-2-piperidone, poly-N-vinyl-4-methyl-2-caprolactam, poly-N-vinyl-3-ethyl-2- Pyrrolidone, and poly-N-vinyl-4,5-dimethyl-2-pyrrolidone, polyvinylimidazole, poly-N, N-dimethylacrylamide, polyvinyl alcohol, polyacrylic acid, polyethylene oxide, poly-2-ethyloxazoline, heparin polysaccharide, Polysaccharides, and mixtures and copolymers thereof, macromonomers It is. Of these, polyvinyl pyrrolidone, poly-N, N-dimethylacrylamide, polyacrylic acid, and polyvinyl alcohol are more preferable in terms of showing good wettability, and the most preferable in terms of having good solubility in the polymerization stock solution. Preferable are polyvinylpyrrolidone and poly-N, N-dimethylacrylamide.

  If the amount of the hydrophilic polymer added is too small, sufficient wettability cannot be obtained, and if it is too large, the solubility in the polymerization stock solution containing the silicone prepolymer is reduced. More preferred is 5 to 25% by weight, and most preferred is 1 to 20% by weight.

  If the molecular weight of the hydrophilic polymer is too small, sufficient wettability cannot be obtained, and if it is too large, the polymerization stock solution becomes too viscous, preferably 1000 to 2 million, more preferably 10,000 to 1 million, 20 10,000 to 800,000 are most preferable.

  When the silicone prepolymer obtained by the production method of the present invention is polymerized to obtain a silicone polymer, a polymerization solvent can be used. Various organic and inorganic solvents can be used as the solvent. Examples include water, methanol, ethanol, propanol, 2-propanol, butanol, t-butanol, t-amyl alcohol, various alcohol solvents such as 3,7-dimethyl-3-octanol, tetrahydrolinalol, benzene, toluene , Xylene and other aromatic hydrocarbon solvents, hexane, heptane, octane, decane, petroleum ether, kerosene, ligroin, paraffin and other aliphatic hydrocarbon solvents, acetone, methyl ethyl ketone, methyl isobutyl ketone and other ketones Solvent, various ester solvents such as ethyl acetate, butyl acetate, methyl benzoate, dioctyl phthalate, ethylene glycol diacetate, diethyl ether, tetrahydrofuran, dioxane, ethylene glycol dialkyl ether, diethyl Various glycol ether solvents such as polyethylene glycol dialkyl ether, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polyethylene glycol-polypropylene glycol block copolymer, polyethylene glycol-polypropylene glycol random copolymer These can be used alone or in combination. Among these, alcohol solvents and glycol ether solvents are preferable because the solvent can be easily removed from the obtained silicone polymer by washing with water.

  The silicone polymer obtained by polymerizing the silicone prepolymer obtained by the production method of the present invention can be used alone after being molded into a desired shape, or can be molded after mixing with other materials. . It is also preferable to apply the coating on the surface of the molded product.

  When the silicone prepolymer obtained by the production method of the present invention is polymerized to form a polymer for use as an ophthalmic lens, the following methods can usually be used as the polymerization method and molding method. For example, a method of once forming a round bar or a plate and processing it into a desired shape by cutting or the like, a mold polymerization method, a spin casting method, or the like.

  As an example, a case where an ophthalmic lens made of a silicone polymer obtained by polymerizing a silicone prepolymer obtained by the production method of the present invention is obtained by a mold polymerization method will be described below.

  The silicone prepolymer composition is filled into the gap between two molds having a lens shape. Then, photopolymerization or thermal polymerization is performed to form a lens shape. A mold made of resin, glass, ceramics, metal, or the like can be used as the mold, but in the case of photopolymerization, an optically transparent material is preferably used, and usually resin or glass is used. When manufacturing an ophthalmic lens, in many cases, a gap is formed by two opposing molds, and the gap is filled with a silicone prepolymer composition. Subsequently, the mold filled with the silicone prepolymer composition in the gap is irradiated with actinic rays such as ultraviolet rays, or placed in an oven or a liquid bath and heated to polymerize the silicone prepolymer. There may be a method of using both in combination, such as heat polymerization after photopolymerization, or conversely photopolymerization after heat polymerization. In the case of photopolymerization, it is common to irradiate light containing a large amount of ultraviolet light using, for example, a mercury lamp or insect trap as a light source for a short time (usually 1 hour or less). When thermal polymerization is performed, the temperature is gradually raised from around room temperature, and the temperature is increased to 60 ° C. to 200 ° C. over several hours to several tens of hours, so that the optical uniformity and quality of the polymer are maintained. And is preferred to improve reproducibility.

  The silicone polymer obtained by polymerizing the silicone prepolymer obtained by the production method of the present invention can be modified by various methods. When the use is an ophthalmic lens and water wettability is not imparted using the above-described internal wetting agent, it is preferable to perform a modification treatment that improves the water wettability of the surface.

  Specific reforming methods include electromagnetic vapor (including light) irradiation, plasma irradiation, chemical vapor deposition treatment such as vapor deposition and sputtering, heating, base treatment, acid treatment, use of other appropriate surface treatment agents, and these Can be mentioned. Among these reforming means, simple and preferred are base treatment and acid treatment.

  Examples of the base treatment or acid treatment include a method in which a molded product is brought into contact with a basic or acidic solution, a method in which a molded product is brought into contact with a basic or acidic gas, and the like. More specific methods include, for example, a method of immersing a molded product in a basic or acidic solution, a method of spraying a basic or acidic solution or basic or acidic gas on the molded product, or a basic or acidic solution on a molded product. Examples of the method include a method of applying the coating with a spatula, a brush, etc., and a basic or acidic solution applied to the molded product by a spin coating method or a dip coating method. The most simple method for obtaining a large modification effect is a method of immersing a molded article in a basic or acidic solution.

  Although the temperature at the time of immersing a silicone polymer in a basic or acidic solution is not specifically limited, Usually, it is performed within a temperature range of about −50 ° C. to 300 ° C. Considering workability, a temperature range of −10 ° C. to 150 ° C. is more preferable, and −5 ° C. to 60 ° C. is most preferable.

  The optimum time for immersing the silicone polymer in a basic or acidic solution varies depending on the temperature, but is generally preferably within 100 hours, more preferably within 24 hours, and most preferably within 12 hours. If the contact time is too long, not only the workability and productivity are deteriorated, but also adverse effects such as a decrease in oxygen permeability and a decrease in mechanical properties may occur.

  High molecular weights such as alkali metal hydroxides, alkaline earth metal hydroxides, various carbonates, various borates, various phosphates, ammonia, various ammonium salts, various amines, polyethyleneimine, and polyvinylamine as bases A base or the like can be used. Of these, alkali metal hydroxides are most preferred because of their low cost and great treatment effect.

  As the acid, various inorganic acids such as sulfuric acid, phosphoric acid, hydrochloric acid and nitric acid, various organic acids such as acetic acid, formic acid, benzoic acid and phenol, and various high molecular weight acids such as polyacrylic acid and polystyrenesulfonic acid can be used. . Among these, a high molecular weight acid is most preferable because it has a large treatment effect and little adverse effect on other physical properties.

  As the solvent for the basic or acidic solution, various inorganic and organic solvents can be used. For example, water, methanol, ethanol, propanol, 2-propanol, butanol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, various alcohols such as glycerin, various aromatic carbonization such as benzene, toluene, xylene Various aliphatic hydrocarbons such as hydrogen, hexane, heptane, octane, decane, petroleum ether, kerosene, ligroin, paraffin, various ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, methyl benzoate, phthalate Various esters such as dioctyl acid, diethyl ether, tetrahydrofuran, dioxane, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether Ter, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether, various ethers such as polyethylene glycol dialkyl ether, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylimidazolidinone, hexamethylphosphoric triamide, And various aprotic polar solvents such as dimethyl sulfoxide, halogen solvents such as methylene chloride, chloroform, dichloroethane, trichloroethane, and trichloroethylene, and fluorocarbon solvents. Of these, water is most preferable from the viewpoints of economy, ease of handling, chemical stability, and the like. As the solvent, a mixture of two or more kinds of substances can also be used.

  The basic or acidic solution used in the present invention may contain components other than the basic or acidic substance and the solvent.

  The silicone polymer can be freed of basic or acidic substances by washing after base treatment or acid treatment.

  As the cleaning solvent, various inorganic and organic solvents can be used. For example, water, methanol, ethanol, propanol, 2-propanol, butanol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, various alcohols such as glycerin, various aromatic carbonization such as benzene, toluene, xylene Various aliphatic hydrocarbons such as hydrogen, hexane, heptane, octane, decane, petroleum ether, kerosene, ligroin, paraffin, various ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, methyl benzoate, phthalate Various esters such as dioctyl acid, diethyl ether, tetrahydrofuran, dioxane, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether Ter, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether, various ethers such as polyethylene glycol dialkyl ether, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylimidazolidinone, hexamethylphosphoric triamide, And various aprotic polar solvents such as dimethyl sulfoxide, halogen solvents such as methylene chloride, chloroform, dichloroethane, trichloroethane, and trichloroethylene, and fluorocarbon solvents.

  As the washing solvent, a mixture of two or more kinds of solvents can also be used. The cleaning solvent may contain components other than the solvent, such as inorganic salts, surfactants, and cleaning agents.

  The modification treatment as described above may be performed on the entire silicone polymer, or may be performed on only a part of the silicone polymer, for example, on the surface only. When the modification treatment is performed only on the surface, only the water wettability of the surface can be improved without greatly changing the properties of the entire silicone polymer.

The oxygen permeability of the silicone polymer obtained by polymerizing the silicone prepolymer obtained by the production method of the present invention is preferably an oxygen permeability coefficient of 70 × 10 ⁻¹¹ (cm ² / sec) mLO ₂ / (mL · hPa) or more. .

  The Strehl ratio of an ophthalmic lens made of a silicone polymer obtained by polymerizing a silicone prepolymer obtained by the production method of the present invention is preferably 0.90 or more, and more preferably 0.95 or more.

  The silicone polymer obtained by polymerizing the silicone prepolymer obtained by the production method of the present invention is particularly suitably used for ophthalmic lenses such as contact lenses, intraocular lenses, and artificial corneas.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.
Analysis Method (1) GPC Measurement GPC measurement was performed under the following conditions.
Column: TSKgel GMH _HR- M × 2 mobile phase: chloroform Column temperature: 40 ° C.
Injection volume: 100 μL
Detector: UV detector (254 nm)
Flow rate: 1 mL / min Sample concentration: 0.4% by weight
Standard Sample: Polystyrene (2) Calculation of Monomer Consumption Rate The polymerization start time is 0, 20, 40, 60, 80, 100, 120, 150, 180, 240, 300, 360, 720 minutes with the drop start time being 0 minutes. Sample approximately 100 μL each. For variables used below, for example, when the sample weight is expressed as Ws (n), it represents the sample weight of the nth sample collected from the polymerization reaction solution. Therefore, Ws (3) represents the weight of the third sample taken, ie the sample taken at 40 minutes. After measuring the weight of the sample collected at each time point, it is diluted with about 2.5 to 3.0 g of chloroform and filtered through a 0.45 μm filter to obtain a GPC measurement sample. X (n) is calculated from the sample weight Ws (n) and the weight Wc (n) of chloroform by the following equation.
X (n) = Ws (n) / Wc (n)
The obtained GPC measurement sample is measured under the GPC measurement conditions of (1) above. The peak area value of the monomer for which the consumption rate in the measurement result is to be obtained is Am (n).

The time at which the sample was collected is t (n), and the solid content (total of all monomers other than the solvent, chain transfer agent, polymerization initiator) added to the polymerization stock solution at the time t (n) is K (n ), The solid content contained in the initial solution A at the start of dropping is K _A (1), the solid content contained in the monomer mixture B at the start of dropping is K _B (1), the completion of the dropping time T _B, the start of the dropping of the solid content contained in the polymerization initiator solution C at K _{C (1),} when the completion of the dropping time of the initiator solution C and T _C,
K (n) = K _A (1) + (t (n) / T _B ) × K _B (1) + (t (n) / T _C ) × K _C (1)
In the same manner, the amount of solvent added to the polymerization stock solution at the time of t (n) is S (n), the amount of solvent contained in the initial solution A at the start of dropping is S _A (1), the start solution C S the amount of solvent which was contained in _{C (1),} when the completion of the dropping time of the initiator solution C and T _C,
S (n) = S _A (1) + (t (n) / T _C ) × S _C (1)
However, the above is an example when the solvent is contained only in the solution A and the initiator solution C. For example, when the solvent is also contained in the solution B, the term of (t (n) / T _B ) × M _B (1) is used. to add.
Y (n) is calculated by the following equation from K (n) and S (n) obtained above.
Y (n) = K (n) / S (n)
Further, R (n) is obtained by the following equation.
R (n) = Am (n) / (X (n) × Y (n))
The monomer amount M _R (n) contained in the polymerization stock solution without polymerization at the time of t (n) is M _R (n) = (R (n) / R (n−1)) × M _R ( n-1) (when n> 1)
M _R (1) = M (1) (when n = 1)
On the other hand, the monomer amount M (n) added to the polymerization stock solution up to the time point t (n) is:
M (n) = M _A (1) + (t (n) / T _B ) × M _B (1)
It is represented by Therefore, assuming that the amount of monomer finally added to the polymerization stock solution is M (13), the monomer consumption rate Z (n) is Z (n) = (M (n) −M _R (n)) / M (13 ) × 100
It is represented by
For each monomer, the monomer consumption rate graph is obtained by plotting the horizontal axis as t (n) and the vertical axis as Z (n).

  Example 1

DMA: N, N-dimethylacrylamide OH-mPDMS: silicone monomer HEMA: 2-hydroxyethyl methacrylate Norblock: UV absorber Blue HEMA: polymerizable dye DSH: dodecyl mercaptan ADVN: polymerization initiator TAA: t-amyl alcohol 1) Monomer Preparation of mixture B In a 300 mL eggplant flask, 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole (ultraviolet absorber, 2.6 g), the following formula (r)

A dye represented by the formula (0.024 g) and N, N-dimethylacrylamide (DMA, 20 g) were added to dissolve the ultraviolet absorber and the dye. Next, 2-hydroxyethyl methacrylate (19.2 g), n-dodecyl mercaptan (DSH, 0.036 g), the following formula (j)

After adding a silicone monomer represented by (OH-mPDMS, 71.2 g), a three-way cock connected to a vacuum line and a nitrogen line was attached, and the inside of the eggplant flask was purged with nitrogen.

2) Preparation of polymerization solution A In a 500 mL four-necked flask, 0.42 g of 2,2′-azobis (2,4-dimethylvaleronitrile) (ADVN), 7 g of DMA, 130 g of t-amyl alcohol (TAA) 7.5% by weight of the monomer mixture B prepared in 1) above was added, a mechanical stirrer, a three-way cock connected to a vacuum line and an argon line were attached, and the inside of the flask was purged with argon.

3) Preparation of initiator solution C 0.42 g ADVN and 50 g TAA were added to a 100 mL flask. The interior of the flask was purged with nitrogen using a three-way cock connected to a vacuum line and a nitrogen line.

4) The polymerization monomer mixed solution B flask and the polymerization solution A flask were connected via a tube pump. The flask of the initiator solution C and the flask of the polymerization solution A were connected in the same manner. The four-necked flask of the polymerization solution A was immersed in a water bath heated to 60 ° C., stirred for 5 minutes, and then dropwise addition of the monomer mixture B and the initiator solution C was started. Samples from the reaction solution at 0, 20, 40, 60, 80, 100, 120, 150, 180, 240, 300, 360, and 720 minutes after the start of dropping Was extracted and chloroform was added to prepare a GPC sample. The dropping end time of the monomer mixture B was 326 minutes, and the dropping end time of the initiator solution C was 260 minutes. Heating was stopped at 720 minutes and cooled to room temperature overnight. The weight of the polymerization solution was measured, and the decreased amount was taken as the solvent scattering amount during the polymerization. GPC measurement was performed on each sample of the reaction solution, and the consumption rates of both monomers were calculated based on the peak areas of OH-mDPMS and DMA. A graph of the polymerization time and the monomer consumption rate was plotted, and the value obtained by dividing the total area between the consumption rate curves of both monomers by the total polymerization time was defined as the ABC value.

After completion of the reaction, the solvent was distilled off with an evaporator. The obtained solid content was dissolved in 150 mL of methanol while heating to 60 ° C., and the obtained solution was added to 300 mL of 40% (v / v) aqueous methanol solution with stirring, and allowed to stand for a while. The supernatant was discarded, and the resulting precipitate was washed once with 300 mL of a 65% (v / v) aqueous methanol solution and once with 300 mL of a 75% (v / v) aqueous methanol solution. The obtained solid content was vacuum-dried at 40 ° C. for 18 hours and then crushed by adding liquid nitrogen. Unfunctional silicone polymer was obtained by vacuum drying at 40 ° C. for 3 hours.
The concentration unit “% (v / v)” refers to a value obtained by dividing the volume of the specific component in the state before mixing by the sum of the volume of each component in the state before mixing and multiplying by 100. That is, a mixture of 40 ml of methanol and 60 ml of water is represented as a 40% (v / v) aqueous methanol solution.

Examples 2-43
In the same manner as in Example 1, except that the initial DMA amount in the initial solution A and the monomer mixture B, the dropping time of the mixture B and the solution C, the initiator amount, and the chain transfer agent amount were changed as shown in Table 2. Polymerization was performed. The ABC value of each Example was as Table 2 and Table 3.

Example 44
Three-way connected to a nitrogen line by adding 30 g of the non-functional polymer obtained in Example 1, 4.5 mg of 2,6-di-t-butyl-4-methylphenol (BHT) and 167 mL of toluene to a 300 mL four-necked flask A cock, mechanical stirrer, and Claisen tube were attached, and a Liebig condenser, bent tube, and eggplant flask were connected to the tip of the Claisen tube. Water was removed from the reaction system by heating to 110 ° C. with stirring under a nitrogen stream and distilling off about 110 g of toluene. After cooling the reaction solution to 60 ° C., 0.516 mL of bismuth (III) (2-ethylhexanoic acid) toluene solution ^{* and} 0.695 mL of 2-isocyanatoethyl methacrylate (MOI) were added under a nitrogen stream at 100 ° C. The reaction was allowed for 5 hours. After completion of the reaction, the reaction solution was cooled to 60 ° C., 20 g of methanol was added, and the mixture was stirred for 30 minutes. The reaction solution was concentrated at 50 ° C. using an evaporator, and 70 g of methanol was added to the obtained solid to dissolve it. The obtained solution was added to 250 mL of a 50% (v / v) aqueous methanol solution while stirring and allowed to stand, and then the supernatant was discarded. The obtained solid content was washed with 200 mL of 70% (v / v) aqueous methanol solution, 200 mL of 75% (v / v) aqueous methanol solution, and 200 mL of 80% (v / v) aqueous methanol solution. The obtained solid content was vacuum-dried overnight at 40 ° C. for 18 hours, then crushed by adding liquid nitrogen, and vacuum-dried at 40 ° C. for 3 hours to obtain the desired silicone prepolymer.
^{* A} solution of bismuth (2-ethylhexanoic acid) in 2-ethylhexanoic acid (Bi: 25%, Wako Pure Chemical Industries, Ltd.) 0.1183 mL (0.1072 g) was diluted with 50 mL of toluene.

Example 45
Add 3.00 g of silicone prepolymer to a solution consisting of polyvinylpyrrolidone K90 (0.55 g), Irgacure 819 (Ciba Specialty Chemicals) 0.04 g and t-amyl alcohol 4.34 g, and mix while heating at 70 ° C. And then degassed under reduced pressure. The solution was returned to normal pressure under argon to remove oxygen and poured into a contact lens mold made of a transparent resin (poly (4-methyl-1-pentene)) in a glove box under a nitrogen atmosphere. The mold was irradiated with light at 55 ° C. (1.6 mW / cm 2, 30 minutes, 20 W fluorescent lamp) and polymerized to obtain a contact lens-shaped sample. The mold was released in borate buffer (pH 7.4 to 7.6), transferred to a vial, and boiled at 120 ° C. for 30 minutes. After cooling, the lens was taken out and immersed in a borate buffer. When the Strehl ratio of the obtained lens was measured, it was 0.97.

Comparative Example 1
The monomers, initiators, and solvents in Table 1 were polymerized in the same manner as in Example 1 except that they were charged all at once instead of dropping into a 500 mL four-necked flask to functionalize and lens. The ABC value at the time of polymerization was 14.4, and the Strehl ratio of the obtained lens was 0.85.

Comparative Example 2
Polymerization was carried out according to the method of Example 9 of Patent Document 2 (US Patent Application Publication No. 2009/0111905), and the ABC value was 7.6. Furthermore, when functionalization and lens formation were performed, the Strehl ratio of the obtained lens was the Strehl ratio of the lens obtained by polymerizing the silicone prepolymer (ABC value 7.15) of Example 2 of the present invention. The value was smaller than the ratio.

  The present invention relates to a silicone prepolymer having a uniform composition, and the polymer obtained by polymerizing the silicone prepolymer is particularly suitably used for ophthalmic lenses such as contact lenses, intraocular lenses, and artificial corneas.

T: polymerization end time S: area between graphs (ΣA _n )
Ra: Monomer consumption rate of monomer a Rb: Monomer consumption rate of monomer a

Claims (19)

A group consisting of monomers having any of a styryl group, an acryloyloxy group, and a methacryloyloxy group,
A group consisting of monomers having any one of an acrylamide group, a methacrylamide group, a vinyl carbonate group, a vinyl carbamate group, a vinyl amide group, and a vinyl ester group is defined as B group,
In the case of selecting and copolymerizing at least one monomer from each of Group A and Group B,
Among the monomers divided into two groups, group A and group B, at least one monomer is a silicone monomer, and at least one monomer is a hydrophilic monomer, and at least one monomer is a hydroxyl group in the molecule, A monomer having at least one reactive functional group selected from an amino group, a carboxyl group and a carboxylic anhydride group;
And in the monomer a and the monomer b respectively selected from the A group and the B group,
When the average value of the monomer consumption rate (%) difference between the monomer a and the monomer b from the start of polymerization to the end of polymerization is the ABC value,
A method for producing a silicone prepolymer, wherein the polymerization is carried out so that the ABC value is 7.15 or less. A dripping liquid and a dripping liquid each containing the silicone monomer, the hydrophilic monomer and the reactive monomer,
S _{A1 is} the sum of the molar concentrations of the monomers contained in the group A in the dripping solution, and S _{B1 is} the sum of the molar concentrations of the monomers contained in the group _{B in} the dripping solution. total _{S A2} molar concentration of the monomer, the sum of the molar concentrations of monomers contained in the group B of the drip solution when the _{S B2} to the following formula _{S A1 / S B1 <S A2} / S B2
Using a dripping liquid and a dripping liquid that satisfy
2. The method for producing a prepolymer according to claim 1, wherein polymerization is carried out while continuously or intermittently adding the dropping solution to the dropping solution. The method for producing a prepolymer according to claim 1 or 2, wherein the monomer selected from Group A has a (meth) acryloyloxy group, and the monomer selected from Group B has a (meth) acrylamide group. The method for producing a prepolymer according to any one of claims 1 to 3, wherein the total content of silicon atoms is 10 to 30% by weight based on the prepolymer solid content. At least one of the silicone monomers is a polar silicone monomer having a polar group in the molecule, and the content of the polar silicone monomer is 30 to 90% by weight based on the solid content of the silicone prepolymer. The method for producing a prepolymer according to claim 4. The polar group is a hydroxyl group, amide group, carboxyl group, amino group, carbonate group, carbamate group, sulfonamide group, sulfonic acid group, phosphoric acid group, methoxyethyl group, methoxyethoxyethyl group, hydroxyethyl group, hydroxyethoxyethyl group The method for producing a prepolymer according to claim 5, wherein the group is a group selected from the group consisting of: 6. The method for producing a prepolymer according to claim 5, wherein the polar group is a hydroxyl group. Among the polar silicone monomers, at least one of the following general formula (d)

The method for producing a prepolymer according to claim 5, wherein the monomer is represented by the formula:
(In formula (d), R represents hydrogen or a methyl group. L represents an alkylene group having 1 to 20 carbon atoms or an arylene group. D represents a silicone group.) Of the polar silicone monomers, at least one of the following general formula (e)

The method for producing a prepolymer according to claim 5, wherein the monomer is represented by the formula:
(In the formula (e), R represents hydrogen or a methyl group. L represents an alkylene group or an arylene group having 1 to 20 carbon atoms. G represents an alkyl group or aryl having 1 to 20 carbon atoms and having 1 to 20 carbon atoms. Represents a group, D represents a silicone group.) D in the general formula (d) and / or (e) is the following general formula (f)

It is represented by these. The manufacturing method of the prepolymer of Claim 8 or 9 characterized by the above-mentioned.
(In formula (f), E ^{1 to} E ¹¹ are each independently hydrogen, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms. H represents an integer of 0 to 200, and i, j, and k each independently represents an integer of 0 to 20, except when h = i = j = k = 0. Of the polar silicone monomers, at least one of the following general formula (s):

The method for producing a prepolymer according to claim 5, wherein the monomer is represented by the formula:
(In the formula (s), n represents an integer of 3 to 10. R _s represents an alkyl group or an aryl group having 1 to 20 carbon atoms.) The hydrophilic monomer is N, N-dimethylacrylamide, 2-hydroxyethyl methacrylate, N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, (meth) acrylic acid, N-vinyl-2-piperidone, N-vinyl. 2-caprolactam, N-vinyl-3-methyl-2-caprolactam, N-vinyl-3-methyl-2-piperidone, N-vinyl-4-methyl-2-piperidone, N-vinyl-4-methyl-2 -Caprolactam, N-vinyl-3-ethyl-2-pyrrolidone, N-vinyl-4,5-dimethyl-2-pyrrolidone, N-vinylimidazole, acryloylmorpholine, N, N-diethylacrylamide, N-isopropylacrylamide A monomer selected from the group Method for producing a prepolymer according to any one of. The method for producing a prepolymer according to claim 1, wherein a solvent having a boiling point of 80 ° C. to 200 ° C. at 1013 hPa is used as the polymerization solvent. A method for producing a prepolymer according to any one of claims 1 to 13, wherein a tertiary alcohol is used as a polymerization solvent. It is obtained by introducing a polymerizable functional group by reacting a compound having a polymerizable functional group with a reactive functional group derived from a monomer having at least one reactive functional group in the molecule after polymerization. The method for producing a prepolymer according to any one of claims 1 to 14. The method for producing a prepolymer according to claim 2, wherein a chain transfer agent is contained in the liquid to be dropped and / or in the liquid to be dropped. The method for producing a prepolymer according to claim 16, wherein the chain transfer agent is an alkyl mercaptan. An ophthalmic lens obtained by polymerizing a prepolymer obtained by the production method according to claim 1. A contact lens obtained by polymerizing a prepolymer obtained by the production method according to claim 1.

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