JPH09194558A - Plastic lens made of sulfur-containing urethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject colorless transparent lens having a high refractive index and a low dispersion, and excellent in heat resistance and also in productivity by adding a specific third component to a mixture of a polythiol having >=4 functions and xylylenediisocyanate. SOLUTION: (C) At least one kind selected from bis(isocyanatocyclohexyl) methane, bis(isocyanatomethyl)cyclohexane, norbornanediisocyanatomethyl, etc., in an amount of <=50mol% is added to a composition consisting of (A) a polythiol having >=4 functional groups of formula I (R1 to R4 are each H, CH2 SH, a group of formula II, a group of formula III, etc.; when any one of R1 to R4 is H, any other one of them is a group of formula II or formula III, and when any two of R1 to R4 are H, the other two of them are groups of formula II or formula III; three or more of R1 to R4 can not be H at the same time), formula IV [(m) is an integer of 1-3] or formula V [(n) is an integer of 0-3] and (B) xylylenediisocyanate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sulfur-containing urethane plastic lens.

[0002]

2. Description of the Related Art Plastic lenses are lighter in weight and less likely to break than inorganic lenses and can be dyed, and are rapidly becoming popular as optical elements such as spectacle lenses and camera lenses.

As a resin widely used for these purposes, there is a resin obtained by radical polymerization of diethylene glycol bis (allyl carbonate) (hereinafter referred to as D.A.C.). This resin is excellent in impact resistance, lightweight, excellent in dyeability,
It has various characteristics such as good machinability such as machinability and polishability.

However, D. A. C. The refractive index of the lens is n _D = 1.50 compared to the inorganic lens (n _D = 1.52)
In order to obtain the same optical characteristics as a glass lens, it is necessary to increase the center thickness, the edge thickness, and the curvature of the lens, and it is inevitable that the lens becomes thick as a whole.
Therefore, a lens resin having a higher refractive index is desired. Further, as one of the lens resins which give a high refractive index, a reaction between an isocyanate compound and a hydroxy compound such as diethylene glycol (Japanese Patent Laid-Open No. 57-13660).
No. 1) or tetrabromobisphenol A
Of a polyurethane system obtained by a reaction with a hydroxy compound containing a halogen atom such as (JP-A-58-164615) or a reaction with a hydroxy compound containing a diphenylsulfide skeleton (JP-A-60-194401). A plastic lens made of resin or the like is known.

Lenses made of these known resins are described in D.I.
A. C. Although the refractive index is improved compared to the lens using, the refractive index is still insufficient, or in order to improve the refractive index, a compound having many halogen atoms or aromatic rings in the molecule is used. Therefore, it has drawbacks such as poor weather resistance and impact resistance, or large specific gravity.

[0006]

The present inventors have previously reacted with pentaerythritol tetrakis (2-mercaptoacetate) (hereinafter abbreviated as PETG) and xylylene diisocyanate (hereinafter abbreviated as XDi). It was found that the thiocarbamic acid S-alkyl ester resin thus obtained has a high refractive index, is colorless and transparent, and has excellent mechanical properties and processability (JP-A-60-199).
No. 016). However, the thiocarbamic acid S-
Even when the strength of the alkyl ester resin is required to be corrected, there is a problem that the refractive index is still insufficient, the edge thickness is increased, and the fashionability is deteriorated.

The inventors of the present invention have made further studies and found a polythiol compound having four or more functional groups, which is a novel compound, and a resin using this has a higher refractive index than a resin using PETG and is colorless and transparent. It has excellent dyeability, heat resistance and productivity, and as a plastic lens material,
It has been found that it is an extremely excellent material (JP-A-7-2
No. 52207). However, depending on the use of the lens, not only the refractive index but also the balance of various performances such as Abbé number, heat resistance, and specific gravity may be emphasized and required, and the above-mentioned invention alone can completely meet the market demand. It was difficult and there was room for further improvement.

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted extensive studies to further improve the above materials, and as a result, have been identified as a mixture of a polythiol having 4 or more of the above functional groups and xylylene diisocyanate. By adding the third component,
Although the refractive index is slightly lowered, they have found that the Abbe number, heat resistance and specific gravity are further improved, and have reached the present invention.

That is, the present invention provides the following formula (1):

[Chemical 6] However, when any one of R ₁ , R ₂ , R ₃ and R ₄ is H, the other one is

Embedded image When any _{two of} R ₁ , R ₂ , R ₃ and R ₄ are H, the other 2 are

Embedded image Selected from the _three , and three or more of R ₁ , R ₂ , R ₃ and R ₄ never become H. ), The following formula (2)

Embedded image (M represents an integer of 1 to 3) and the following formula (3).

Embedded image (N represents an integer of 0 to 3), and 50 mol% or less of bis (isocyanatocyclohexyl) with respect to the composition of polythiol having 4 or more functional groups represented by any of the above and xylylene diisocyanate. Sulfur-containing urethane resin composition comprising at least one third component selected from the group consisting of methane, bis (isocyanatomethyl) cyclohexane, norbornane diisocyanatomethyl and pentaerythritol tetrakis (mercaptoacetate), and heating the composition. It is a sulfur-containing urethane type plastic lens obtained by curing.

Examples of the polythiol represented by the formula (1) include the following compounds.

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Examples of the polythiol represented by the formula (2) include the following compounds.

Embedded image

Examples of the polythiol represented by the formula (3) include the following compounds.

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The tetrathiol or higher functional polythiol used in the present invention is described in the literature [The Chemistry of th.
can be produced by any of the general methods for synthesizing polythiols described in [ethiol group], but from the viewpoint of coloring the product, the compounds of the following formulas (4) to (6) are reacted with thiourea, The isothiuronium salt method in which isothiuronium is chlorinated and is hydrolyzed is preferable.

The following equation (4)

Embedded image If any one of A ₁ , A ₂ , A ₃ and A ₄ is H, then the other one is

Embedded image When any _{two of} A ₁ , A ₂ , A ₃ and A ₄ are H, the other two are

[Chemical 21] No more than three of A ₁ , A ₂ , A ₃ , and A ₄ are H. X represents an OH group, or a chlorine atom, a bromine atom, an iodine atom, a methanesulfonyl group, a benzenesulfonyl group, or a p-toluenesulfonyl group,
Each may be the same or different. ), The following formula (5)

Embedded image (M represents an integer of 1 to 3 and X has the same meaning as described above) and the following formula (6).

Embedded image (N represents an integer of 0 to 3 and X has the same meaning as described above), examples of the polyol, polyhalogen compound and halide having a hydroxy group include organic low molecular epoxy compounds such as epihalohydrin and butadiene epoxide, Glycerin derivatives such as 2-chloro-1,3-propanediol, thioglycerol and tribromopropane,
1,2,3,4-tetrabromobutane, 1,2,3
Obtained by reacting an organic low-molecular halide such as 4,5-pentachloropentane with an ethylene derivative such as 2-mercaptoethanol or ethylene oxide and a sulfide such as sodium hydrosulfide, sodium sulfide, potassium sulfide or hydrogen sulfide. To be

In addition, formulas (4) containing polyhalides
The desorption substrate of the formula (6) is the O of a corresponding polyol of the formulas (4) to (6) and a halide having a hydroxy group.
It can also be obtained by reacting with a H group and introducing a leaving group.

As a method for introducing a leaving group by reacting with an OH group, a general reaction from alcohol can be used. For example, a method of reacting hydrogen halide such as hydrochloric acid, hydrobromic acid and hydroiodic acid, a method of using the hydrogen halide and a metal halide such as zinc chloride, an alkali metal salt such as potassium iodide and sodium bromide. And methods using acids such as sulfuric acid and phosphoric acid, methods using halogen and phosphorus, methods using thionyl chloride, phosphorus tribromide, phosphorus pentachloride, methanesulfonyl chloride, benzenesulfonyl chloride, p-toluenesulfonyl chloride and the like. .

The isothiuronium chlorination reaction in the next step is
The polyfunctional compound of the formulas (4) to (6) is reacted with 4 equivalents or more, preferably 4 to 8 equivalents of thiourea with respect to the compound. At this time, when there is an OH group, the reaction is carried out by adding 1 equivalent or more, preferably 1 to 5 equivalents of a mineral acid to the OH group. As the mineral acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, phosphoric acid and the like can be used, but hydrochloric acid or hydrobromic acid is preferable from the viewpoints of reaction rate and economy and coloring of the product.

In the subsequent hydrolysis reaction, an inorganic base such as sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, sodium acetate and potassium phosphate, or an organic base such as ammonia, triethylamine and hydrazine is added to the above reaction solution. And the like with respect to the polyfunctional compound of formula (4) to formula (6), 4 equivalents or more, preferably 4 to 20.
An equivalent amount is added and hydrolysis is performed to obtain the desired tetrafunctional or higher polythiol. The sulfur-containing urethane resin obtained by adding the third component to the tetrathiol or higher functional polythiol and xylylene diisocyanate according to the present invention is colorless and transparent, has no optical distortion, has a high refractive index and low dispersion (high Abbe number), and has a low It is a resin with a specific gravity that is excellent in impact resistance, dyeability, heat resistance, and processability, and has physical properties that are satisfactory as a resin for plastic lenses.

The sulfur-containing urethane resin of the present invention has the formula (1) to
Group of (3) tetrafunctional or more polythiol and xylylene diisocyanate, bis (isocyanatocyclohexyl) methane, bis (isocyanatomethyl) cyclohexane, norbornane diisocyanatomethyl and pentaerythritol tetrakis (mercaptoacetate) as the third component It can be obtained by reacting with at least one selected from

In the present invention, various known reactive compounds may be added for the purpose of modifying the resin. For example, a hydroxy compound, a mercapto compound, a mercapto compound having a hydroxy group, an isocyanate compound,
Examples thereof include an isothiocyanate compound, an isothiocyanate compound having an isocyanate group, a compound having an unsaturated bond, an epoxy compound, an episulfide compound and a spiropyran compound.

The mixing ratio of the xylylene diisocyanate used in the present invention and the polythiol represented by the formulas (1) to (3) is such that the molar ratio of (NCO) / (SH) functional groups is usually 0.5 to 3. Within the range of 0.0, preferably within the range of 0.5 to 2.0.

The plastic lens of the present invention is made of a thiocarbamic acid S-alkyl ester resin or a dithiourethane resin, and has a thiocarbamic acid S-alkyl ester bond with an isocyanato group and a mercapto group or an isothiocyanato group and a mercapto. The group is mainly composed of a dithiourethane bond, but depending on the purpose, it may of course contain an alohanate bond, a urea bond, a thiourea bond, a burette bond or the like.

For example, the thiocarbamic acid S-alkyl ester bond is further reacted with an isocyanato group,
Increasing crosslink density by further reacting the dithiourethane bond with an isothiocyanato group often gives favorable results. In this case the reaction temperature is at least 10
The temperature is raised to 0 ° C. or higher, and a large amount of isocyanate component or isothiocyanate component is used. Alternatively, an urine bond or a biuret bond can be used by partially using an amine or the like. When using a compound other than the above-mentioned active hydrogen compound that reacts with an isocyanate compound or an isothiocyanate compound, it is necessary to pay particular attention to coloring.

Depending on the purpose, as in the known molding method, various internal release agents, chain extenders, crosslinking agents, light stabilizers, ultraviolet absorbers, antioxidants, oil-soluble dyes, fillers and the like can be used. The substance may be added.

In order to adjust the reaction rate to a desired value, a known reaction catalyst used in the production of polyurethane may be added appropriately.

The lens of the present invention is usually obtained by cast polymerization. Specifically, xylylene diisocyanate, a third component, and a tetrafunctional or higher polythiol represented by the formulas (1) to (3) are mixed, and this mixed solution is defoamed by an appropriate method as necessary. After that, the mixture is poured into a mold and polymerized while gradually raising the temperature from a low temperature of about 0 to 30 ° C to a high temperature of about 100 to 180 ° C. At this time, a known release treatment may be applied to the mold in order to facilitate the release property after the polymerization.

The sulfur-containing urethane resin according to the present invention thus obtained has an extremely low dispersion, a high refractive index, excellent heat resistance, is colorless and transparent, has no optical distortion, is lightweight, has weather resistance and is dyed. It has excellent properties such as resistance, impact resistance, and workability, and is suitable as a material for optical elements such as eyeglass lenses and camera lenses, glazing materials, paints, and adhesives.

Further, the lens made of the sulfur-containing urethane resin according to the present invention is provided with antireflection, high hardness, abrasion resistance, chemical resistance improvement, antifogging property, or fashionability as required. In order to improve the impartation, a physical or chemical treatment such as surface polishing, antistatic treatment, hard coat treatment, anti-reflection coat treatment, dyeing treatment, light control treatment can be applied.

[0029]

The present invention will be described below in more detail with reference to examples and comparative examples. In the performance test of the obtained lens, the refractive index, Abbe number, weather resistance, optical strain, impact resistance, heat resistance, and dyeability were evaluated by the following test methods.

Refractive index, Abbe number: Measured at 20 ° C. using a Bruchrich refractometer. Weather resistance: The lens resin was set in a weatherometer equipped with a sunshine carbon arc lamp, and after 200 hours, the lens was taken out and the hue of the lens resin before the test was compared. The evaluation criteria were no change (○), slight yellowing (△), and yellowing (x). Optical distortion: Visually judged by a distortion tester. The case where no optical distortion was observed was marked with ◯, and the case where optical distortion was observed was marked with x. Impact resistance; 1 from 127 cm height according to FDA standards
An iron ball of 6.3 g was dropped, and those that did not crack were rated as ◯, those that cracked were rated as Δ, and those that cracked were rated as x. Heat resistance: Measured by the TMA (Peneto) method. Dyeability; 90 ° C disperse dye (Mitsui Toatsu Dye MLP Bl
ue-2) The resin test piece was submerged in 0.5% by weight aqueous dispersion while stirring the dispersion, and taken out after 10 minutes,
Washed. ○ Stained ones, × unstained ones
And

Synthesis Example 1 92.5 g (1.0 mol) of epichlorohydrin was added to a mixed solution of 78.1 g (1.0 mol) of 2-mercaptoethanol and 2.0 g of triethylamine for 1 hour while keeping the internal temperature at 35 to 40 ° C. Then, the mixture was dropped and aged at 40 ° C. for 1 hour. Na ₂ S. 9H ₂ O 12
An aqueous solution prepared by dissolving 5.0 g (0.5 mol) in 100 g of pure water was added dropwise over 1 hour while maintaining the internal temperature at 40 to 45 ° C., and further aged at 45 ° C. for 1 hour to give the following tetrafunctional compound. Obtained. Identification was performed by NMR.

[0032]

Embedded image Next, 303.8 g (3.0 mol) of 36% hydrochloric acid and 190.3 g (2.5 mol) of thiourea were added to the above reaction solution,
The mixture was heated and stirred at 110 ° C for 9 hours. After cooling to room temperature, 400 ml of toluene was added, and 25% ammonia water 306.5 was added.
g (4.5 mol) was gradually added, and hydrolysis was carried out at 60 ° C. for 3 hours. The obtained organic layer was treated with 100% of 36% hydrochloric acid.
1, 100 ml of water, 100 ml of dilute ammonia water, 10 water
After sequentially washing twice with 0 ml, toluene was distilled off by a rotary evaporator, dusts and the like were filtered by suction filtration, and the following polythiol (hereinafter, F
SH4) 174.6 g (0.476 mol,
Yield 95.2%) was obtained.

[0033]

Embedded image Each of these isomers was isolated and identified by reverse phase chromatography. First, FSH4- (A)
Ingredient

[0034]

Embedded image The results of elemental analysis, IR, MS, and NMR are shown below.

[0035]

[Table 1] <IRν _max (KBr) cm ⁻¹ > 2543 (SH) <MS> m / z = 366 (M ⁺ ).

[0036]

[Table 2] Next, the FSH4- (C) component

[0037]

Embedded image It shows about. Elemental analysis, IR and MS were the same as (A).

[0038]

[Table 3] Finally, of the FSH4- (B) component

[0039]

Embedded image It shows about. Elemental analysis, IR and MS were the same as (A).

[0040]

[Table 4]

Example 1 The following isomer mixture polythiol FSH

Embedded image 3.6.7 g (0.10 mol), m-xylylene diisocyanate 27.5 g (0.146 mol) and norbornane diisocyanatomethyl (abbreviated as NBDi) 11.
After mixing 1 g (0.054 mol) and homogenizing, the mixture was poured into a mold composed of a glass mold and a gasket made of thermoplastic elastomer manufactured by Mitsui Petrochemical Co., Ltd.
It was cured by heating to 20 ° C. for 12 hours. The sulfur-containing urethane plastic lens thus obtained was colorless and transparent, and had no cloudiness in the peripheral portion due to elution from the gasket. In addition, Table 1 shows the physical properties of the obtained lens.

Examples 2 to 5 Plastic lenses were obtained in the same manner as in Example 1 except that the third component was changed. Table 1 shows the physical property values of the obtained plastic lenses.

Example 6 A plastic lens was obtained in the same manner as in Example 1 except that the polythiol and the third component were replaced. Table 1 shows the physical property values of the obtained plastic lenses.

Comparative Examples 1 and 2 Polythiols used in Example 1 or Example 6 and m-xylylene diisocyanate were mixed, and a plastic lens was obtained in the same manner as in Example 1. The physical properties are shown in Table 1.

[0045]

[Table 5]

[0046]

Embedded image

[0047]

EFFECTS OF THE INVENTION The sulfur-containing urethane resin and lens using tetrathiol or higher functional polythiol and specific polyisocyanate according to the present invention are colorless and transparent, have high refractive index and low dispersion, and have excellent heat resistance. It also has excellent productivity.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Mamoru Tanaka Mitsui Toatsu Chemical Co., Ltd. 30 Asamudacho, Omuta City, Fukuoka Prefecture

Claims (2)

[Claims] 1. The following formula (1): And when any one of R ₁ , R ₂ , R ₃ and R ₄ is H, the other one is When any _{two of} R ₁ , R ₂ , R ₃ and R ₄ are H, the other 2 are Selected from the _three , and three or more of R ₁ , R ₂ , R ₃ and R ₄ never become H. ), The following formula (2) (M represents an integer of 1 to 3) and the following formula (3): (N represents an integer of 0 to 3), and 50 mol% or less of bis (isocyanatocyclohexyl) with respect to the composition of polythiol having 4 or more functional groups represented by any of the above and xylylene diisocyanate. A sulfur-containing urethane resin composition comprising at least one third component selected from the group consisting of methane, bis (isocyanatomethyl) cyclohexane, norbornane diisocyanatomethyl and pentaerythritol tetrakis (mercaptoacetate). 2. A sulfur-containing urethane-based plastic lens obtained by heat-curing the composition according to claim 1.