JPH04342583A - Polyisocyanate compound, optical material and optical product obtained by using the same - Google Patents

Abstract

PURPOSE:To obtain the subject new compound capable of providing an optical material and a plastic lens, having a high refractive index and Abbe's number and excellent in heat resistance and mechanical properties. CONSTITUTION:A compound expressed by formula I (n1 is 0-3; n2 is 2-4), e.g. 2,5-diisocyanatomethyltetrahydrothiophene. The compound expressed by formula I (n1 is 1; n2 is 2) is obtained by reacting a compound expressed by formula II (X is Cl, Br or I) with a compound expressed by the formula MOCN (M is a metallic element such as Na, K or Ag).

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD The present invention relates to polyisocyanate compounds, optical materials and optical products obtained using the same. The polyisocyanate compound of the present invention is used, for example, as a useful raw material for optical plastic lens materials. In addition, the optical material of the present invention obtained using the above polyisocyanate compound has a high refractive index, low dispersion, and excellent optical properties, and is used for optical applications such as lenses, prisms, optical fibers, recording medium substrates, filters, etc. Preferably used in products. Furthermore, decorative items such as glasses and flower vases that take advantage of their high refractive index are also included in the optical products referred to here.

0002

BACKGROUND OF THE INVENTION Plastic lenses have been used in optical applications such as various lenses in recent years because they are lighter, less likely to break, and easier to dye than glass. Polyethylene glycol bisallyl carbonate (CR-39) and polymethyl methacrylate (PMMA) are generally used as plastic lens materials for this purpose. The refractive index of these plastic materials is 1.50 or less, and when used as a lens material, for example, as the power increases, the lens must be made thicker, and the advantage of plastics, such as light weight, is lost. Therefore, when used as a lens for spectacles, the esthetics deteriorated, which was not preferable. Further, in particular, in the case of a concave lens, the thickness around the lens becomes thick, causing birefringence and chromatic aberration, which is not desirable. Therefore, there is a need for a high refractive index, low dispersion plastic material that can reduce the thickness of the lens while taking advantage of the characteristics of plastic with low specific gravity, and has less chromatic aberration. Materials for this purpose include tetrachloromethaxylylenedithiol and 1
, 3,5-trimercaptobenzene and a diisocyanate compound is disclosed in JP-A-63-46213. Further, a polymer of pentaerythritol tetrakisthiopropionate and diisocyanate is disclosed in JP-A-64-26622. Furthermore, a polymer of pentaerythritol tetrakisthiopropionate and a vinyl compound was disclosed in JP-A-63-3095.
It is disclosed in Publication No. 09.

0003

[Problem to be Solved by the Invention] However, the above-mentioned Japanese Patent Application Laid-Open No. 63-46213 and Japanese Patent Application Laid-Open No. 64-26622
Although the isocyanate compound described in the publication has a high refractive index, it has a low Abbe number, and a polyadduct of this compound with a thiol compound has a low Abbe number and poor weather resistance. Further, the polymer described in JP-A-63-309509 also has the drawbacks of low refractive index, low Abbe number, and poor heat resistance. Therefore, an object of the present invention is to provide a new polyisocyanate compound that eliminates the above-mentioned drawbacks, and new optical materials and optical products using the same as a raw material.

0004

[Means for Solving the Problems] The present invention has been made to achieve the above object, and the novel polyisocyanate compound of the present invention is characterized by being represented by the general formula (I).

[0005]

[Chemical 3]

[0006] In the formula, n1 is an integer of 0 to 3. Moreover, n2 is an integer of 2 to 4, and the substituent (II
) can be arbitrarily added to each of the 2, 3, 4, and 5-positions of the tetrahydrothiophene ring.

[0007]

[C4]

Further, the novel optical material of the present invention is a polyisocyanate compound (a1
), a compound (b1) containing two or more hydroxyl groups in one molecule, a compound (b2) containing two or more mercapto groups in one molecule, and one or more in one molecule It is characterized in that it is obtained by polymerizing a component (B) containing at least one of the hydroxy groups of and at least one compound (b3) having one or more mercapto groups.

The present invention will be explained in detail below. The novel polyisocyanate compound of the present invention is characterized by having a tetrahydrothiophene ring which is an alicyclic sulfide. This tetrahydrothiophene ring increases the refractive index and Abbe number of the polyisocyanate compound itself, so
When an optical material is manufactured using this polyisocyanate compound, the refractive index and Abbe number of the optical material are also increased. Further, since the tetrahydrothiophene ring of this polyisocyanate compound is rigid, when an optical material is manufactured using this polyisocyanate compound, it provides high heat resistance and excellent mechanical properties to the optical material.

The reason why n1 in the general formula (I) is limited to an integer of 0 to 3 will be described. When n1 is 4 or more, the refractive index of the polyisocyanate compound decreases, and the refractive index of the optical material obtained using the polyisocyanate compound as a raw material tends to decrease, and the heat resistance also tends to decrease, which is not preferable. In addition, in general formula (I), n2 is described as 2 to 4 because the substituent (
II) of the 2,3,4,5- tetrahydrothiophene ring
This shows that only one can be added to each position arbitrarily. In the general formula (I), the polyisocyanate compound of the present invention has n1 = 1, n2 = 2 (2,5
- position), it can be synthesized by the method shown in the following formula.

[0011]

[C5]

[0012] However, in the formula, X is Cl, Br, I,
Further, M is a metal element such as Na, K, Ag or the like. The synthesis method was shown above, n1 = 1, n2 = 2 (2,5-
General formula (I) other than the polyisocyanate compound of
Examples of the polyisocyanate compounds include the following. However, it is not limited to these.

[0013]

[C6]

[0014]

[C7]

[0015]

[Chemical formula 8]

Next, the optical material of the present invention obtained using the polyisocyanate compound of the general formula (I) will be described. This optical material contains the polyisocyanate compound (a1) represented by the general formula (I). Component (A) and a compound having two or more hydroxyl groups in one molecule (b1
), a compound (b2) having two or more mercapto groups in one molecule, and a compound (b3) having one or more hydroxyl groups and one or more mercapto groups in one molecule. (B) and is obtained by polymerization reaction. Since the compound of general formula (I) in component (A) has already been described in detail here, its explanation will be omitted.

In addition to the compound represented by the general formula (I), component (A) contains two or more iso(thio)cyanate groups in one molecule in order to appropriately improve the physical properties of the optical material. It may contain one or more kinds of compounds. These compounds specifically include xylylene diiso(thio)cyanate, 3,3'-dichlorodiphenyl-
4,4'-diiso(thio)cyanate, 4,4'-diphenylmethane diiso(thio)cyanate, hexamethylene diiso(thio)cyanate, isophorone diiso(thio)cyanate, 2,2',5,5 '-Tetrachlorodiphenyl-4,4'-diiso(thio)cyanate, tolylene diiso(thio)cyanate, 1,3-bis(iso(
Examples include thio) cyanate methyl) cyclohexane. In addition, the above-mentioned iso(thio)cyanate means both an isocyanate and an isothiocyanate, and the iso(thio)cyanate group means both an isocyanate group and an isothiocyanate group. The amount of the compound represented by general formula (I) to be used is 0.1 based on the total amount of component (A).
-100 mol%, preferably 5-100 mol%
%.

Specific examples of the hydroxy group-containing compound (b1) used in component (B) include ethylene glycol, trimethylolpropane, glycerin, dihydroxybenzene, catechol, 4,4'-dihydroxyphenyl sulfide, and 2- Examples include hydroxyethyl sulfide. The mercapto group-containing compound (b2) used in component (B) includes 1,2-ethanedithiol, 1,3-propanedithiol, tetrakismercaptomethylmethane, pentaerythritol tetrakismercaptopropionate, pentaerythritol tetrakismercapto Acetate, 2,5-dimercaptomethyl-1,4-dithiane, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 1,3,5-benzenedithiol, 1,2 −
Dimercaptomethylbenzene, 1,3-dimercaptomethylbenzene, 1,4-dimercaptomethylbenzene,
Examples include 1,3,5-trimercaptomethylbenzene, toluene-3,4-dithiol, tris(3-mercaptopropyl)isocyanurate, and the like. In addition, component (B
) The hydroxy group- and mercapto group-containing compounds (b3) used include 2-mercaptoethanol, 2-mercaptoethanol,
, 3-dimercaptopropanol, 1,2-dihydroxy-3-mercaptopropane, 4-mercaptophenol and the like.

The usage ratio of component (A) and component (B) (component (A)/component (B)) is such that the ratio of (iso(thio)cyanate group)/(mercapto group + hydroxy group) is 0.95.
It is preferably within the range of ~1.05. Furthermore, additives such as ultraviolet absorbers, antioxidants, color inhibitors, and fluorescent dyes may be added as appropriate to improve weather resistance. Further, a catalyst for improving polymerization reactivity may be used as appropriate, and organic tin compounds, amine compounds, etc. are effective.

As an example, the production of the optical material of the present invention using the polyisocyanate compound of the present invention will be described below. A homogeneous mixture of the above components (A), component (B), additives and catalysts is poured into a mold using a known cast polymerization method, that is, a mold made of a glass or metal mold and a resin gasket, and heated. and harden. At this time, in order to facilitate the removal of the resin after molding, the mold may be subjected to mold release treatment in advance, or a release agent may be mixed into the mixture of component (A) and component (B). The polymerization temperature varies depending on the compound used, but is generally -20
At ˜+150° C., the polymerization time is 0.5 to 72 hours. The optical material of the present invention can be easily dyed in water or an organic solvent using a conventional disperse dye, and at this time, a carrier may be added or heated to further facilitate dyeing. The optical material thus obtained is particularly preferably used as a plastic lens, although it is not limited thereto.

[0021]

[Examples] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. (Evaluation of physical properties) The physical properties of the polyisocyanate compounds and their optical materials (polymers) obtained in Examples and Comparative Examples were evaluated as follows. The refractive index (nD) and Abbe number (νD) were measured at 20° C. using an Abbe refractometer 3T manufactured by Atago. Appearance was observed with the naked eye. A lens (an optical product using an optical material) was set in a weather meter equipped with a weather-resistant sunshine carbon arc lamp, and after 200 hours, the lens was taken out and the hue was compared with the lens before the test. Evaluation criteria remain unchanged (
〇), slight yellowing (△), and yellowing (×). TMA measurement was performed using a heat-resistant Rigaku TMA device with a 0.5 mm diameter pin under a load of 10 gf, and at a rate of 10°C/min.
Evaluation was made based on the peak temperature of the chart obtained by increasing the temperature. Visual observation was performed using the optical distortion Schlieren method. Those with no distortion were marked as ○, and those with distortion were marked as ×.

(Example 1) The polyisocyanate compound of the present invention, 2,5-isocyanatemethyltetrahydrothiophene (general formula (I)
), n1 = 1, n2 = 2 (2,5-position)) Production Example 2,5-dibromomethyltetrahydrothiophene (54
．． 8 g, 0.2 mol), potassium cyanate (32.
4g, 0.4mol) and dimethylformamide 15
0ml of the mixture was heated to 115°C for 15 hours. After cooling, the solid matter was removed by filtration, and the solvent was distilled off. Thereafter, the residue was distilled under reduced pressure to obtain 19.2 g (yield: 48.5%) of a colorless and transparent liquid with a boiling point of 114° C./3 mmHg. The IR spectrum of this product showed absorption due to isocyanate groups (2275 cm-1), so it was found to be the desired product. nd/νd=1.5289/44.9. The IR spectrum of this new polyisocyanate compound is shown in FIG.

(Example 2) Example of manufacturing an optical product of the present invention 2,5-diisocyanatemethyltetrahydrothiophene (indicated as DIT-1 in Tables 1 to 3) obtained in Example 1 0.1 mol, 2 ,5-dimercaptomethyl-1,
4-dithiane (denoted as DMMD in Tables 1 to 3) 0.1
A mixture of 1×10 −5 mol and dibutyltin dilaurate (indicated as DBTDL in Tables 1 to 3) was stirred uniformly, poured into two glass molds for lens molding, and
℃ for 10 hours, then 60℃ for 5 hours, then 120℃
The mixture was polymerized by heating for 3 hours to obtain a plastic lens. Various physical properties of the obtained plastic lenses are shown in Tables 1 to 3. From Tables 1 to 3, the polymer of Example 2 is colorless and transparent, has a very high refractive index (nD) of 1.66, and has a high Abbe number (νD) of 36 (low dispersion). , excellent weather resistance and heat resistance (115° C.), and no optical distortion.

(Examples 3 to 9) Examples of manufacturing other optical products of the present invention Plastic lenses were obtained by carrying out the same operations as in Example 2, except that the monomer compositions shown in Tables 1 to 3 were used. Ta. The physical properties of these plastic lenses are shown in Tables 1 to 3 together with the physical properties of the polymer of Example 2. From Tables 1 to 3, the plastic lenses of Examples 3 to 9 are colorless and transparent, have a very high refractive index (nD) of 1.60 to 1.64, and have an Abbe number (νD) of 37 to 40. High (low dispersion)
It had excellent weather resistance and heat resistance (106 to 124°C), and was free of optical distortion.

(Comparative Example 1) Pentaerythritol tetrakismercaptopropionate (PET in Tables 1 to 3)
MP) 0.1 mol, m-xylylene diisocyanate (expressed as XDI in Tables 1 to 3) 0.2 mol, and dibutyltin dilaurate (DBTD in Tables 1 to 3)
A mixture of 1 x 10-5 mol (denoted as L) was stirred uniformly, poured into two glass molds for lens molding, and heated at 50°C for 10
After that, the mixture was polymerized by heating at 60° C. for 5 hours and then at 120° C. for 3 hours to obtain a plastic lens. Various physical properties of the obtained plastic lenses are shown in Tables 1 to 3. From Tables 1 to 3, the plastic lens of this comparative example was colorless and transparent, and no optical distortion was observed, but (nD)/(νD) was 1.
．． The temperature was low at 59/36, and the heat resistance was also poor at 86°C.

(Comparative Examples 2 and 3) Plastic lenses were obtained in the same manner as in Comparative Example 1, except that the monomer compositions shown in Tables 1 to 3 were used. The physical properties of these plastic lenses are shown in Tables 1 to 3 together with the physical properties of the polymers of Examples 2 to 10 and Comparative Example 1. From Tables 1 to 3, the plastic lens of Comparative Example 2 has a high refractive index of 1.68 and excellent heat resistance (128°C), but is yellow in color.
It had a low Abbe number, poor weather resistance, and optical distortion was observed. Further, the plastic lens of Comparative Example 3 was colorless and transparent, and had excellent heat resistance (113° C.) and weather resistance, but the refractive index was as low as 1.57, and optical distortion was observed.

[0027]

Effects of the Invention The novel polyisocyanate compound of the present invention has a tetrahydrothiophene ring, so it has a high refractive index and Abbe number, and is a compound having two or more hydroxyl groups in one molecule. It easily undergoes a polymerization reaction with at least one of a compound having a mercapto group and a compound having one or more hydroxyl groups and one or more mercapto groups in one molecule to provide an optical material. In addition, since the optical material of the present invention obtained using this polyisocyanate compound contains a tetrahydrothiophene ring in the main chain, it has a high refractive index and Abbe number, and has good heat resistance, weather resistance,
Because of its excellent transparency, it is preferably used in optical products such as lenses such as eyeglass lenses and camera lenses, recording medium substrates used in optical fibers, optical disks, magnetic disks, etc., and filters. Furthermore, it is also used in decorative items such as glasses and flower vases that take advantage of its high refractive index.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an IR spectrum of the polyisocyanate compound obtained in Example 1.

[Table 1]

[Table 2]

[Table 3]

Claims (4)

[Claims] 1. A polyisocyanate compound represented by general formula (I). embedded image In the formula, n1 is an integer of 0 to 3. Also, n
2 is an integer of 2 to 4, and only one substituent (II) can be optionally added to each of the 2, 3, 4, and 5-positions of the tetrahydrothiophene ring. [Case 2] 2. A component (A) containing the polyisocyanate compound (a1) according to claim 1, a compound (b1) having two or more hydroxyl groups in one molecule, and a compound (b1) containing two or more hydroxyl groups in one molecule. Compound (b2) having a mercapto group
and a component (B) containing at least one of the compounds (b3) having one or more hydroxyl groups and one or more mercapto groups in one molecule. . 3. An optical product characterized by using the optical material according to claim 2. 4. The optical product according to claim 3, wherein the optical product is a plastic lens.