JPH0533248B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing a new crosslinked polymer, and more specifically, to provide a transparent resin that is excellent in terms of heat resistance, moldability, water absorption, hardness, etc. [Prior art and its problems] Conventional transparent resins have been used for plastic lenses, compact disks, etc.
The resin itself was not completely satisfactory in terms of specific gravity, moldability, light transmittance, heat resistance, etc. For example, polymethyl methacrylate (hereinafter abbreviated as PMMA), which is known as a transparent resin, has a large water absorption rate, and therefore has a problem in that its refractive index changes greatly depending on humidity. In addition, resins made by polymerizing diethylene glycol bisallyl carbonate (hereinafter referred to as
(abbreviated as ADC) still had problems in terms of hardness, heat resistance, water absorption, etc. [Means for Solving the Problems] As a result of intensive research into resins that solve the above-mentioned problems, the present inventors discovered that neopentyl glycol bisallyl carbonate (hereinafter referred to as N-
It has been found that a polymer (abbreviated as BAC) has significantly superior transparency, hardness, water absorption resistance, etc. Therefore, the present invention provides a method for producing such a polymer. That is, the present invention provides the general formula (In the formula, R ₁ is H or CH ₃ ; R ₂ is CH ₂ , CH ₂
OCH ₂ CH ₂ ,

[expression] or

〔Example〕

EXAMPLES Hereinafter, in order to specifically explain the present invention, Examples will be given and explained, but the present invention is not limited to these Examples. In addition, the crosslinked polymer obtained in the example is
Various physical properties were measured by the following test methods. (1) Specific gravity: Measured at a temperature of 20°C according to JISZ8807. (2) Refractive index (η ²⁰ _D ): Measured at 20° C. using Atsube's refractive index, using monobromnaphthalene as the contact liquid. (3) Atsube's number: Measured using Atsube's refractive index at 20°C. Monobromnaphthalene was used as the contact liquid. (4) Rockwell hardness (L scale): Measured with Rockwell hardness tester, initial load 10Kg, test load 60
Kg, steel ball diameter 6.35±0.0025mm, load weight was released after 15 seconds, and measured 15 seconds later. (5) Shrinkage rate: Calculated from the specific gravity of the monomer and the specific gravity of the lens. (6) Coefficient of thermal expansion: Measured using alumina as a reference, thermocouple P-R temperature raised from 25℃ to 125℃.
℃, Rate 10k/minR±250μ (7) Absorption rate: Measured from the weight increase rate after soaking a lens piece in water at 23℃ for 3 days. (8) Light transmittance: Measured on a 2 mm thick test piece using a Hays meter (Toyo Seiki Seisakusho). Example 1 3.1g of diisopropyl peroxydicarbonate (hereinafter abbreviated as IPP), which is a polymerization catalyst, was added to 100g of neopentyl glycol bisallyl carbonate, and the mixture was thoroughly stirred for 5 minutes at room temperature.
After completely degassing with a vacuum pump, the glass plate was poured into a mold fixed with a gasket, and cast polymerization was performed. At this time, the material of the mold was an ethylene-vinyl acetate copolymer, and injection was performed under pressure with _N2 gas. The glass mold injected with the monomer was placed in an air oven programmed to gradually increase the temperature from 40℃ to 90℃ over 19 hours. After 19 hours, the mold was left at a constant temperature of 60℃ for 1 hour and then released. I did this and got a plastic cleanse. Then, to reduce optical distortion,
The lenses were post-cured for 2 hours at °C. For comparison, a lens was obtained using ADC under the same conditions as above. The physical properties of the obtained lenses were measured and the results are shown in Table 1. Table 1 N-BAC ADC specific gravity 1.220 1.313 η ²⁰ _D 1.490 1.499 Atsube number 60.8 57.9 Rozquell hardness L scale 112 98 Shrinkage rate (%) 11 15 Water absorption rate (%) 0.04 0.27 Light transmittance (%) 93 92 Coefficient of thermal expansion 25 〜75℃ 91×10 ^-6 14×10 ^-5 75～125℃ 12×10 ^-5 13×10 ^-5 Example 2 Add a radical polymerization initiator to 100 parts by weight of neopentyl glycol bisallyl carbonate used in Example 1 A mixed solution to which 3 parts by weight of benzoyl peroxide was added was poured into a mold, and cast polymerization was performed. Polymerization was performed using an air oven starting at a temperature of 50°C and gradually increasing the temperature to 10°C.
The temperature was set to 90°C for an hour, and once the temperature reached 90°C, the mixture was further heated at that temperature for 3 hours. After the polymerization was completed, the same operation as in Example 1 was performed. The decomposition temperature of the colorless and transparent crosslinked polymer of neopentyl glycol bisallyl carbonate thus obtained is approximately 360°C.
The refractive index η ²⁰ _D was 1.483, the light transmittance was 92%, the Rockwell hardness was 110, the specific gravity was 1.198, and the water absorption was 0.03. Example 3 Instead of the neopentyl glycol bisallyl carbonate used in Example 1, neopentyl glycol bisallyl carbonate, other copolymerizable monomers shown in Table 2, and a radical polymerization catalyst (concentration 2.5 parts by weight) were used. The same procedure as in Example 1 was carried out except for using the following. The results were as shown in Table 2. The abbreviations used in Table 2 are as follows: MMA: Methyl methacrylate ADC: Diethylene glycol bisallyl carbonate DAP: Diallyl phthalate EDMA: Ethylene dimethacrylate

[Table] Example 4 is a polymerization catalyst for 100gr of carbonate.
After adding 1.5g of IPP, it was poured into a mold and cast polymerization was performed. Polymerization was carried out using an air oven, starting at a temperature of 20°C and gradually increasing the temperature.
The temperature was raised to 90°C for 19 hours, and after 19 hours, the mold was released after being left at a constant temperature of 60°C for 1 hour. The subsequent operations were performed in the same manner as in Example 1. The results were as shown in Table 3.

【table】

[Table] Example 5 In Example 1, Instead of neopentyl glycol bisallyl carbonate, A post-cured lens was manufactured in the same manner as in Example 1, except that . The physical properties of the obtained lenses were measured and the results are shown in Table 4.

【table】

[Table] Example 6 In Example 1, Instead of neopentyl glycol bisallyl carbonate, A post-cured lens was manufactured in the same manner as in Example 1, except that . The physical properties of the obtained lenses were measured and the results are shown in Table 4.

[Brief explanation of the drawing]

Figure 2 is a chart of the infrared absorption spectrum of the neopentyl glycol monomer, and Figure 2 is a chart of the infrared absorption spectrum of the polymer. These infrared absorption spectra are from JEOL Ltd.
Measured using FTIR-100.

Claims (1)

[Claims] 1. General formula (In the formula, R ₁ is H or CH ₃ ; R ₂ is CH ₂ , CH ₂
OCH ₂ CH ₂ , [Formula] or [Formula]) from the group consisting of carbonate (first monomer), carboxylic acid and carboxylic acid ester having an unsaturated bond capable of radical polymerization in the molecule A method for producing a crosslinked polymer, which comprises polymerizing at least one selected copolymerizable monomer (second monomer).