阅读说明：本技术 一种低收缩树脂及其制备方法与应用 (Low-shrinkage resin and preparation method and application thereof ) 是由 温俊霞 钱建平 花蕾 于 2020-05-25 设计创作，主要内容包括：本发明公开了一种低收缩树脂及其制备方法与应用,所述制备方法,包括以下步骤：步骤一,按化学计量比称取二烯丙基二甘醇碳酸脂、季戊四醇或三羟甲基丙烷、催化剂和阻聚剂MEHQ,在120～160℃真空负压条件下反应并不断搅拌,生成低收缩树脂和副产物丙烯醇；步骤二,在线监测,当产物低收缩树脂的含量和折射率达到要求,停止反应；步骤三,冷却降温,过滤除去催化剂；步骤四,如果产物的色度大于30,要利用活性炭进行脱色处理所述应用为低收缩树脂在折射率为1.499的平定双光镜片和折射率为1.499的渐进半成品镜片中的应用。本发明的产品产率高,且折射率和粘度可控,适合推广应用。(The invention discloses a low-shrinkage resin and a preparation method and application thereof, wherein the preparation method comprises the following steps: weighing diallyl diglycol carbonate, pentaerythritol or trimethylolpropane, a catalyst and a polymerization inhibitor MEHQ according to a stoichiometric ratio, reacting at the temperature of 120-160 ℃ under a vacuum negative pressure condition, and continuously stirring to generate low-shrinkage resin and a byproduct of allyl alcohol; secondly, monitoring on line, and stopping reaction when the content and the refractive index of the low-shrinkage resin of the product meet the requirements; cooling, and filtering to remove the catalyst; and step four, if the chroma of the product is more than 30, decoloring by using activated carbon, wherein the application is the application of the low-shrinkage resin in a flat bifocal lens with the refractive index of 1.499 and a progressive semi-finished lens with the refractive index of 1.499. The product of the invention has high yield, controllable refractive index and viscosity, and is suitable for popularization and application.)

1. A low shrinkage resin, characterized in that it has the chemical formula:

or

2. A preparation method of low-shrinkage resin is characterized by comprising the following steps:

weighing diallyl diglycol carbonate, pentaerythritol or trimethylolpropane, a catalyst and a polymerization inhibitor methyl hydroquinone or p-hydroxyanisole according to a stoichiometric ratio, reacting at the temperature of 120-160 ℃ under a vacuum negative pressure condition, and continuously stirring to generate low-shrinkage resin and allyl alcohol;

secondly, monitoring on line, and stopping reaction when the content and the refractive index of the low-shrinkage resin meet the requirements;

and step three, cooling, and filtering to remove the catalyst.

3. The method for preparing a low shrinkage resin according to claim 2, wherein: the stirring speed in the first step is 85-150 r/min.

4. The method for preparing a low shrinkage resin according to claim 2, wherein: the reaction time in the first step is 10-16 h.

5. The method for preparing a low shrinkage resin according to claim 2, wherein: the molar excess of the diallyl diglycol carbonate is 60-150%.

6. The method for preparing a low shrinkage resin according to claim 2, wherein: the theoretical value in the second step is 65-150 mm²/s。

7. The method for preparing a low shrinkage resin according to claim 2, wherein: and (3) decoloring the product obtained after the treatment in the third step by using activated carbon, wherein the chroma of the product is more than 30.

8. The method for preparing a low shrinkage resin according to claim 2, wherein: the catalyst is calcium oxide or calcium hydroxide.

9. The method for preparing a low shrinkage resin according to claim 7, wherein: the treatment of the calcium hydroxide comprises the following steps:

preheating a muffle furnace before use, firstly heating to 190-200 ℃, preserving heat for 1-2 h, then heating to 400-420 ℃, preserving heat for 1-2 h, then heating to 720-900 ℃, preserving heat for 1-2 h, and turning off for later use;

and secondly, putting the calcium hydroxide into a crucible, then putting the crucible into a muffle furnace, and sintering for 4-5 hours at 720-900 ℃.

10. Use of a low shrink resin according to claim 1 in a flat bifocal lens with a refractive index of 1.499 and a progressive semi-finished lens with a refractive index of 1.499.

Technical Field

The invention relates to the field of resin, in particular to low-shrinkage resin and a preparation method and application thereof.

Background

The 1.499 lenses were the earliest resin lenses, the first generation of ultra-light, impact resistant resin lenses. As an optical lens, the 1.499 lens has proper refractive index, low specific gravity of 1.32 (almost half of glass), Abbe number of 58-59 (low dispersion), impact resistance and high light transmittance, and can be dyed and coated. At present, trimethylolpropane type low-shrinkage 1.499 resin is sold in the market, but the trimethylolpropane type resin in the market has more low-boiling-point impurities, is not beneficial to the quality control of lenses, is easy to appear that the lenses are brittle and fragile, is not easy to be cured and molded, and is easy to yellow.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention aims to provide a low-shrinkage resin with high yield and better performance, the invention also aims to provide a preparation method of the low-shrinkage resin with controllable viscosity and refractive index, and the invention further aims to provide application of the low-shrinkage resin in a flat bifocal lens with the refractive index of 1.499 and a progressive semi-finished lens with the refractive index of 1.499.

The technical scheme is as follows: the invention relates to a low-shrinkage resin, which has a chemical structural formula as follows:

or

The preparation method of the low-shrinkage resin comprises the following steps:

weighing diallyl diglycol carbonate, pentaerythritol or trimethylolpropane, a catalyst and a polymerization inhibitor methyl hydroquinone or p-hydroxyanisole according to a stoichiometric ratio, reacting at the temperature of 120-160 ℃ under a vacuum negative pressure condition, continuously stirring at the stirring speed of 85-150 r/min, and reacting for 10-16 h to generate low-shrinkage resin and allyl alcohol;

step two, carrying out online monitoring, wherein when the viscosity reaches a theoretical value of 65-150 mm²(s), stopping the reaction;

and step three, cooling, and filtering to remove the catalyst.

If the reaction product is reddish due to the polymerization inhibitor or the chroma of the product after the third step is more than 30, the color can be removed by using active carbon, and then the product is filtered again and collected. After the product comes out, the percentage content, the chromaticity, the moisture, the viscosity, the refractive index and the experimental shrinkage rate of the lens are detected and blended. In the reaction process, with the continuous rise of the temperature, the reactant solid can be continuously dissolved, and the propylene alcohol can be continuously discharged. Strictly controlling the amount of allyl alcohol, namely sampling in a kettle to check a gas chromatography result, testing the percentage content and the refractive index of a product, and stopping the reaction if the percentage content and the refractive index of the product meet the requirements. Wherein the molar excess of the diallyl diglycol carbonate is 60-150%.

The catalyst is calcium oxide or calcium hydroxide. The treatment of calcium hydroxide comprises the following steps:

preheating a muffle furnace before use, firstly heating to 190-200 ℃, preserving heat for 1-2 h, then heating to 400-420 ℃, preserving heat for 1-2 h, then heating to 720-900 ℃, preserving heat for 1-2 h, and turning off for later use;

and secondly, putting the calcium hydroxide into the crucible, then putting the crucible into a muffle furnace, and sintering the crucible for 4-5 hours at 750-800 ℃ at a distance which is equal to the distance from the periphery in the furnace and cannot lean against the furnace wall. Unnecessary impurities are burnt, water in the catalyst is removed, the catalyst is further purified, and the using effect is good.

The calcium oxide is put in an oven at 120 ℃ and kept for 4h for use.

The application of the low-shrinkage resin in a flat bifocal lens with a refractive index of 1.499 and a progressive semi-finished lens with a refractive index of 1.499 is realized by mixing the low-shrinkage resin with an initiator and performing thermosetting molding.

The reaction principle is as follows:

wherein the diallyl diglycol carbonate (ADC), also called diglycol dipropenyl carbonate, has a structural formula

Has the advantages that: compared with the prior art, the invention has the following remarkable characteristics: the prepared low-shrinkage resin has a good spatial structure, fewer low-boiling-point products, controllable product viscosity and refractive index, and good hardness and toughness of the prepared lens, and compared with the low-shrinkage resin prepared by using trimethylolpropane, the prepared low-shrinkage resin has fewer low-boiling-point products and better product performance than the products on the market; the method for integrally preparing the low-shrinkage resin saves time, labor and labor, is beneficial to reducing the cost, and basically meets the requirement of green reaction on product feeding and conversion.

Drawings

FIG. 1 is a GC inspection of a pentaerythritol low shrink resin of the present invention;

FIG. 2 is a GC inspection of a trimethylolpropane low shrinkage resin of the present invention.

Detailed Description

The raw materials in the following examples were purchased and used as received.

The preparation of calcium oxide comprises the following steps:

(1) preheating a muffle furnace before use, firstly heating to 190-200 ℃, preserving heat for 1-2 h, then heating to 400-420 ℃, preserving heat for 1-2 h, then heating to 720-900 ℃, preserving heat for 1-2 h, and turning off for later use;

(2) and (3) putting the calcium hydroxide into a crucible, and then putting the crucible into a muffle furnace, wherein the distance between the calcium hydroxide and the periphery of the muffle furnace is equal, the calcium hydroxide cannot lean against the furnace wall, and the calcium hydroxide is sintered for 4-5 hours at 750-800 ℃.

The calcium oxide is put in an oven at 120 ℃ and kept for 4h for use. Whether the calcium oxide is sintered or not affects the reaction time, the reaction time of the unsintered calcium oxide is long, and a yield difference of 10-20% exists.