JPH0275613A - Styrenic thermosetting organic glass - Google Patents

Abstract

PURPOSE:To improve the transparency, impact resistance and solvent resistance by polymerizing and curing a composition which comprises styrene, a specific compound and a radical polymerization initiator. CONSTITUTION:1mole of a 1:1 mixture (a) of 2,4,4-trimethylhexamethylene diisocyanate (i) with 2,2,4-trimethylhexamethylene diisocyanate (ii) is subjected to addition reaction with 2 moles of hydroxyethyl (meth)acrylate (b) in the presence of a urethanation catalyst to produce and addition product (B). A mixture of 20-70wt.% styrene (A) with 30-80wt.% component (B) is blended with a radical polymerization initiator (C) (e.g., dibutyltin dilaurate) in an amount of 0.01-10wt.% for the mixture (C) to obtain a composition. The resulting composition is poured into a mold, and heated to polymerize and cure for 0.1-24hr.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a styrenic thermosetting organic glass which has excellent transparency and is particularly suitable for use in plastic lenses.

(Prior art and its problems) Organic glass, ie, transparent plastic, has advantages over glass, such as being lightweight and easy to mass produce.

Representative examples are poly(diethylene glycol bisallyl carbonate), poly(methyl methacrylate), poly(
styrene), poly(carbonate), etc.

However, especially when considered for use in plastic lenses, poly(diethyreglycol bisallyl carbonate) has the drawbacks of a refractive index of 1.50, which is lower than inorganic glass, and a specific gravity of 1.32, which is still high.

Poly(methyl methacrylate) has a refractive index of 1°49, lower than that of inorganic glass, and has the disadvantage of poor solvent resistance. Poly(
carbonate) has a high refractive index of 1.59 but poor solvent resistance. Further, although poly(styrene) is lightweight, has a high refractive index, and is inexpensive, it has drawbacks such as poor strength and poor solvent resistance.

Furthermore, since poly(methyl methacrylate), poly(carbonate), and poly(styrene) are thermoplastic resins, they require expensive molds for molding, and it is necessary to prepare a wide variety of grades for, for example, eyeglass lenses. is uneconomical for some applications.

Therefore, there is a demand for thermosetting organic glass that has advantages in transparency, lightness, refractive index, price, etc., and also has excellent solvent resistance. Attempts are being made.

For example, in JP-A-51-79353, a copolymer of styrene and diethylene glycol bisallyl carbonate is applied to a plastic lens. but,
With this combination, the cured product becomes cloudy and is not practical as an organic glass.

Furthermore, according to JP-A-58-168614 (hereinafter referred to as the application), rA: a vinyl monomer that provides a polymer with a refractive index of 1.55 or more, and B: an isocyanate compound and a hydroxyl group. A resin j for lenses has been proposed, which is obtained by addition polymerizing a composition consisting of a vinyl monomer containing the following: and a mixture in which the molar ratio of NC010H is 0.5 to 2.0. However, the present inventors used xylylene diisocyanate, isophorone diisocyanate, or 1,6-hexamethylene diisocyanate as the A component: styrene, B component: isocyanate compound, and hydroxyethyl acrylate as the vinyl monomer containing a hydroxyl group, When the application was retested by setting the molar ratio of N COlo H to 1.0, it was found that all of the obtained polymerized cured products were cloudy and opaque, and had no practical use as organic glass or plastic lenses. Furthermore, the degree of white turbidity was more pronounced as the amount of styrene monomer increased. The reason for this cloudiness is thought to be that the monomer composition in the composition changes as the polymerization progresses, and the cured product obtained in the early stage of polymerization and the cured product obtained in the late stage of polymerization are not compatible with each other. .

The present inventors have clearly demonstrated that styrene-containing polymers have advantages in light weight, refractive index, and price, and have improved their disadvantages of impact resistance and solvent resistance, while at the same time being colorless and transparent without clouding. We believed that if we could obtain a cured product with the desired properties, the scope of its application as an organic glass would extend to the entire range of existing inorganic glasses, so we conducted intensive studies to obtain an organic glass with the desired performance using styrene as the main component.

As a result, poly(
The present invention was achieved by discovering that it is possible to obtain an organic glass that maintains the light weight and refractive index of styrene, has excellent impact resistance and solvent resistance, and has good compatibility with the cured product and is free from cloudiness. This is what I did.

[Means for Solving the Problems] That is, the present invention has a specific gravity of 1.19 or less and a refractive index (N20°C D) obtained by polymerizing and curing a mixture consisting of the following a component, b component, and C component. It relates to a thermosetting organic glass having a temperature of 1.52 or more.

a: Styrene 20-70% by weight b = (
(a) 1 mole of a 1:1 mixture of 2,4.4-trimethylhexamethylene diisocyanate and 2,2,4-1-limethylhexamethylene diisocyanate, and (b) hydroxyethyl methacrylate (or acrylic acid, =-)) 2
C: Radical polymerization initiator 0.01 to 10% by weight based on the sum of components a and b When the styrene component a is less than 20% by weight, the viscosity of the mixture decreases. It has the drawbacks of high refractive index, poor operability, and low refractive index of the cured product. When the styrene content exceeds 70% by weight, the cured product becomes cloudy and has the drawback of insufficient solvent resistance.

The l:l mixture of (a) 2,4.4-trimethylhexamethylene diisocyanate and 2.2゜4-trimethylhexamethylene diisocyanate as component b of the present invention is:
It is a 1:1 mixture of the following formulas (il and (ii)). By using this diisocyanate, an organic glass with good compatibility of the cured product and no cloudiness can be obtained for the first time.

CH3 C1, + CH.

0CN-CHzCC+hCHCHzCIIz-NCO(
li) Tylhexamethylene diisocyanate alone is difficult to obtain industrially, and only a mixture is usually sold.

(b) Hydroxyethyl methacrylate (or acrylate) refers to 2-hydroxyethyl methacrylate or 2-hydroxyethyl acrylate.

(a) and (b) are subjected to an addition reaction in advance at a molar ratio of 1 mole of (a) to 2 moles of (b).

As a result, the following addition compound is obtained.

CH3 (wherein MAc represents a methacrylic group).

L (wherein Ac represents an acrylic group).

Although the urethanization addition reactions (a) and (b) proceed without a catalyst, it is preferable to use a known urethanization catalyst, such as dibutyltin silaurylate, stannath octoate, triethylenediamine, diazabicycloundecene. It is best to add @ amount of etc. Urethanization catalysts are available from Imori Publishing, “Polymer Experiments Volume 5, Double Condensation and Polyaddition First Edition,” 17
This is explained in detail in pages 56-68 of "Polyaddition and Addition Condensation, 1st Edition by Minoru Imoto and Keikichi Uno" by Kagaku Doujin. The usage amount is 0.00 for the total amount of (a) and (b)
The range is 1 to 0.5%. If it exceeds 0.5% by weight, it will be difficult to control the addition reaction and it will be wasteful. Although a reaction solvent is not particularly required, component C (styrene) of the present invention can be used as it is instead of the reaction solvent. Chloroform, methylene chloride, benzene, toluene,
After the addition reaction in a low boiling point solvent such as THE, the solvent may be distilled off.

Component b acts as a crosslinking agent and increases the solvent resistance and heat resistance of the cured product. At the same time, component b has the function of improving impact resistance, which is a drawback of styrene polymers. The amount of component b used is in the range of 30 to 80% by weight. If it is less than 30% by weight, the cured product will lack solvent resistance, and the compatibility between the initial product and the late product of the cured product will be poor, resulting in white turbidity.

If it exceeds 80% by weight, the advantages such as lightness and economy are diminished, and there are also disadvantages such as high viscosity of the mixture, poor curing operation, and low refractive index of the resulting cured product.

The radical polymerization initiator of component C refers to a known thermal polymerization initiator that is commercially available. Kagaku Doujin “Takayuki Otsu; Revised Chemistry of Polymer Synthesis 2nd Edition” pages 59-69 and Nippon Oil & Fats “
An example is given in "Organic Peroxides, 12th Edition".

Specifically, benzoyl peroxide, diisopropyl peroxycarbonate, abbisisobutyronitrile, L-
Examples include butyl peroxy (2-ethylhexanoate) and bis(t-butyl peroxide).

The amount of the radical polymerization initiator is 0.01-10% by weight, preferably 0.1% by weight, based on the total amount of component C and component b.
~5% by weight. When it is less than 0.01% by weight, polymerization is insufficient and unpolymerized bones tend to remain. Also,
If it exceeds 10% by weight, it will be difficult to control polymerization and it will be wasteful.

The composition before curing may contain, without departing from the spirit of the present invention,
By adding a small amount of a monomer that can react with component a or component b, it is possible to widen the physical properties of the cured product, such as strength, heat resistance, dyeability, coating properties, etc., and the range of polymerization and curing conditions.

Such reactive monomers include, for example, α-methylstyrene, chlorostyrene, divinylhenzene, phenyl acrylate, phenyl methacrylate, hensyl acrylate, benzyl methacrylate, naphthyl acrylate, naphthyl acrylate, ethylene glycol dimethacrylate, hydroxyethyl methacrylate. ,
Hydroxyethyl acrylate, phosphoric acid ester of hydroxyethyl methacrylate, diacrylate and dimethacrylate of bisphite alcohol A and ethylene oxide adduct, glycerin diacrylate, glycerin dimethacrylate, methacrylate of glycerin monophenyl ether, trimethylolpropane diacrylate, trimethylol Propane triacrylate, pentaerythritol triacrylate, pentaerythritol tetra(β-thiopropionate), trimethylhexamethylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, xylylene diisocyanate,
Examples include hexamethylene diisocyanate, ethylene glycol, propylene glycol, butanediol, xylylene diol, and the like.

In addition, known polymerization inhibitors, antioxidants, ultraviolet absorbers,
It is of course possible to add a small amount of additives such as a mold release agent to improve the operability of the pre-cured composition and to improve the practicality of the obtained polymerized and cured product.

Polymerization and curing of the present invention is usually carried out as follows.

■ a: Styrene, b: 1 mol of a mixture of 2,2.4-trimethylhexamethylene diisocyanate and 2.4°4-trimethylhexamethylene diisocyanate and 2 hydroxyethyl methacrylate (or acrylate)
The moles of the addition compound and C: the radical polymerization initiator are uniformly mixed.

■Pour the mixture into the mold.

(2) The polymerization and curing reaction is advanced by heating, and the product is removed from the mold after 0.1 to 24 hours.

(Effects of the Invention) The present invention improves impact resistance and solvent resistance, which are disadvantages of poly(styrene), which is advantageous in lightness, refractive index, and cost among conventional organic glass raw materials, and at the same time, it is colorless without clouding. It gives a transparent cured product.

That is, the thermosetting organic glass of the present invention is colorless and transparent, and has a higher refractive index (N20°C D) than poly(diethylene glycol bisallyl carbonate) or poly(methyl methacrylate). Furthermore, despite containing a large amount of styrene units, it has excellent impact resistance and solvent resistance.
Good weather resistance. Moreover, it is lightweight with a specific gravity of 1.19 or less.

Therefore, it is suitable for reducing the weight and improving the strength of conventional inorganic glass, and can be used in a wide range of applications such as plates and cast products as an alternative to inorganic glass.

In particular, since it is lightweight, has good transparency, and has a higher refractive index than poly(diethylene glycol bisallyl carbonate), it can be suitably used as a plastic lens, such as a vision correction lens.

(Example) The present invention will be explained in more detail with reference to Examples below.

In addition, the physical property values were determined by the following method.

■ Color: Determined visually, if there is no coloration or cloudiness, it is considered good.

■ Refractive index (N20℃D) and Atsbe number (ν20℃D)
: Measured by Atsube refractometer.

■ Specific gravity: Comparison with standard specific gravity liquid.

■ Weather resistance: Good if there is no discoloration after 200 hours of exposure to Suga Test Instruments Sunshine Weather Meter.

■ Heat resistance: Vicat softening temperature of 100''C or higher is considered good.

■ Strength: Thickness 2. A 16 g steel ball is dropped from a height of 127 cm onto a 0 mm plate, and a case where it does not break is considered good.

■ Solvent resistance: Rub the board with a cloth soaked in methanol or acetone, and if there is no clouding, it is considered good.

■ Dyeability Items that can be dyed with a niblastic lens dye are considered good.

■ Workability: Good if a smooth cutting surface can be obtained using a polishing machine.

Example 1 47 g (0.45 mol) of styrene, trimethylhexamethylene diisocyanate (2,4,4- and 2.2
．． 429 g (0.22 mol) of hydroxyethyl methacrylate, and 0.01 g of dibutyltin silaurylate were uniformly mixed and stirred for 1 hour to form urethane. A chemical reaction was carried out.

Add 1g of diisopropyl peroxycarbonate to the mixture.
After adding and mixing well, the mixture was poured into a mold consisting of two glass plates and a rubber gasket. Next, from 35°C to 5
8 hours to 5°C, 3 hours from 55°C to 70°C,
The temperature was raised from 70°C to 110°C over 3 hours, and 11
It was kept at 0°C for 1 hour. After cooling, the cured resin plate was taken out. The obtained resin plate had the following physical properties and was excellent as a material for organic glass, especially plastic lenses.

Color: Good refractive index (N20℃D): 1.549 Atsube number (
ν20°C D): 40 Specific gravity: 1.128 Weather resistance: Good Heat resistance: Good (Vicat softening temperature 119°C) Strength;
Good solvent resistance: Good dyeability: Good processability: Good Comparative Examples 1-2 When using zero-generation H diisocyanate 47 g of styrene
, 53 g of an addition compound of 1 mole of metaxylene diisocyanate and 2 moles of hydroxyethyl methacrylate, and monobutylperoxy(2-ethylhexanoei) Ig as a radical polymerization initiator were mixed and cured in the same manner as in Example 1. did. The obtained resin plate was opaque and cloudy.

Similarly, 47 g of styrene, 53 g of an addition compound of 1 mole of inphorone diisocyanate and 2 moles of hydroxyethyl methacrylate, and 1 g of t-butylperoxy(2-ethylhexanoate) were mixed and obtained in the same manner as in Example 1. The resin plate obtained was opaque and cloudy.

Examples 2 to 5 Component C: styrene, component B nitrimethylhexamethylene diisocyanate (2,4,4- and 2°2.4-1
1 mixture) and 2 moles of hydroxyethyl methacrylate, and component C: radical polymerization initiator t-butylperoxy(2-ethylhexanoate) (abbreviated as PBO) in the amounts shown in Table 1. A resin plate was obtained by curing in the same manner as in Example 1.

Table 1 shows the physical properties of the obtained resin plate.

Comparative Examples 3 to 6 A component in a bottle using the amount of C component and B component of zero firing ■:
Styrene, component b nitrimethylhexamethylene diisocyanate (2,4,4- and 2°2.4-1: 1r
Ll) addition compound of 1 mol and 2 mol of hydroxyethyl methacrylate, and component C diradical polymerization initiator P
A resin plate was obtained by curing in the same manner as in Example 1 using BO in an amount outside the scope of the claims of the present application as shown in Table 1.

Table 1 shows the physical properties of the obtained resin plate.

Example 6 Styrene 48 g (0.45 mol), trimethylhexamethylene diisocyanate (2,4,4- and 2.2
．． 25 g (0.12 mol) of 4-l:1 mixture), 28 g (0.24 mol) of hydroxyethyl acrylate
, PBOIg, and dibutyltin silaurylate 0
．． 01g was mixed uniformly, stirred for 1 hour, and then poured into a mold consisting of two glass plates and a rubber gasket.

Next, it was cured in the same manner as in Example 1, and the resin plate was taken out. The obtained resin plate had the following physical properties.

Color: Good refractive index (N20℃D): 1. 552 Atsube number (νF141 Specific gravity: 1.134 Weather resistance: Good Heat resistance: Good (Vicat softening temperature 122"C) Strength:
Good solvent resistance: Good dyeability: Good Processability: Good

Claims (1)

[Claims] (1) A composition consisting of the following components a, b, and c, obtained by polymerization and curing, has a specific gravity of 1.19 or less and a refractive index (
N^2^0^℃_D) Thermosetting organic glass with a temperature of 1.52 or higher. a: 20 to 70% by weight of styrene b: (a) 1 mole of a 1:1 mixture of 2,4,4-trimethylhexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, and (b)
Hydroxyethyl methacrylate (or acrylate)
30-80% by weight of addition compound with 2 moles c: radical polymerization initiator 0.01-10% by weight (2% by weight based on the sum of components a and b)
) A plastic lens made of the thermosetting organic glass according to claim 1.