JPS6164706A - Production of liquid prepolymer - Google Patents

Abstract

PURPOSE:To produce a liquid prepolymer which does not gel and exhibits excellent prolonged storage stability, by polymerizing an unsaturated monomer based on an alkylene glycol bis (allyl carbonate) in a specified solvent and removing the solvent from the product. CONSTITUTION:An unsaturated monomer based on an alkylene glycol bis(allyl carbonate), e.g., diethylene glycol bis(allyl carbonate), is polymerized in at least one solvent selected from the group consisting of ketones, ethers and aromatic hydrocarbons, and the solvent is removed from the product. It is possible to obtain a liquid prepolymer which can not be heretofore obtained, does not gel even at a conversion >=17%, has a desired degree of polymerization and a low viscosity and can be stored for a long time at room temperature. On casting, this prepolymer can give a good polymer molding of an alkylene glycol bis(allyl carbonate), freed from swelling from a mold, polymerization shrinkage and polymerization strain.

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a method for producing a liquid prepolymer of an unsaturated monomer containing alkylene glycol bis(allyl carbonate) as a main component. The present invention relates to a method for producing a liquid prepolymer that can be stored at room temperature for a long period of time.

(Prior art) Alkylene glycol bis(allyl carbonate), typified by diethylene glycol bis(allyl carbonate), is used as a monomer for transparent plastics. Polymers with excellent optical and mechanical properties can be obtained by polymerization, and are particularly popular. It is widely used as an organic glass (lens). However, these polymer molded products of alkylene glycol bis(allyl carbonate) are generally produced by a cast polymerization method after adding a radical initiator to the corresponding monomer. However, these seven polymers of fullkylene glycol bis(allyl carbonate)
When attempting to obtain a polymer molded product having sufficient hardness for practical use, large polymerization shrinkage occurs during polymerization.

For example, diethylene glycol bis(allyl carbonate) undergoes as much as about 14% shrinkage during polymerization. Therefore, in cast polymerization, which is a common polymerization method for alkylene glycol bis(allyl carbonate), it is difficult to obtain sufficient precision.

(Problem to be Solved by the Invention) For this reason, several methods have been proposed to reduce the polymerization shrinkage rate of fullkylene glycol bis(allyl carbonate). A method of producing a liquid prepolymer by heating and polymerizing after adding an agent, and a method of producing a liquid prepolymer by heating and polymerizing the monomer of fullkylene glycol bis(allyl carbonate), which has a low polymerization shrinkage rate and is copolymerized with the fullkylene glycol bis(allyl carbonate). There is a method of adding a possible second monomer. However, in the former method for producing liquid prepolymers, the three-dimensional crosslinking reaction progresses and gelation occurs when the monomer polymerization rate reaches about 17%, so the shrinkage rate during polymerization can only be improved to about 12%. . In addition, in the latter method of adding the second monomer, in order to sufficiently improve the polymerization shrinkage rate, it is necessary to add a large amount of the second monomer, and as a result, the resulting polymer molded product is There is a problem that the excellent optical properties and mechanical properties originally possessed by alkylene glycol bis(7lyl carbonate) resin are impaired.

(Means for solving the problem) In view of the above, the present invention provides alkylene glycol bis(
As a result of intensive research in order to reduce the high polymerization shrinkage rate, which is a drawback of resins whose main component is allyl carbonate (hereinafter abbreviated as AGAC), we have developed an unsaturated monomer whose main component is AGAC in a specified solvent. We have discovered that by removing the polymerized hindlimb solvent, a prepolymer that does not gel even at a polymerization rate of 17% or more, which could not be produced conventionally, can be obtained, leading to the present invention. be. That is, according to the present invention, even if the polymerization rate of unsaturated monomers reaches 17% or more during the production of a prepolymer, the three-dimensional crosslinking reaction does not proceed, there is no fear that gelation will occur, and the desired polymerization can be achieved. It is possible to produce a liquid prepolymer with a low viscosity and high viscosity, which can be stored at room temperature for a long period of time, and by further polymerizing the prepolymer, an excellent polymer can be obtained.

Examples of AGAC used in the present invention include ethylene glycol bis(allyl carbonate), diethylene glycol bis(allyl carbonate), triethylene glycol bis(7lyl carbonate), propylene glycol bis(7lyl carbonate), and dipropylene glycol. Bis(7lyl carbonate).

Polyoxyfulkylene polyol bis(7lyl carbonate) and the like.

In addition, an unsaturated polymer copolymerizable with AGAC as described above may be added to generally 50%
It is also possible to use them together within the range of mol% or less.

Such copolymerizable unsaturated monomers are selected appropriately depending on the final desired AGAC polymer molded article, and can impart various improved properties such as a high refractive index and excellent mechanical properties, or obtain a polymer. It is used to reduce the polymerization rate during polymerization. In order to obtain an ACAC polymer molded product (lens) with a particularly high refractive index,
A copolymerizable unsaturated monomer whose homopolymer has a refractive index of 1.5 or more is used. The copolymerizable unsaturated monomers preferably used in the present invention generally include vinyl compounds, heptalyl compounds, etc. Typical examples include vinyl acetate, vinyl chloride, vinyl alcohol, styrene, and copolymer compounds. Vinyl compounds such as styrene and methylstyrene; methyl methacrylate, methyl acrylate, and ethylene glycol dimethacrylate.

Ethylene glycol bisglycidyl methacrylate, 2
-Hydroxyethyl methacrylate, phenyl methacrylate, bisphenol A dimethacrylate, 2.2
- ivy acid esters and acrylic acid esters such as bis(4-methacryloxyethoxyphenyl)propane,
Diallyl phthalate, diallyl terephthalate, diallyl in 7-thaleate, diallyl tartrate, diallyl epoxysuccinate, diallyl maleate, tri-7lyl isocyanurate.

Examples include heptalyl compounds such as allyl salicylate and allyl phenyl carbamate.

In the present invention, it is extremely important to selectively use ethers, ketones, or aromatic hydrocarbons as the polymerization solvent in order to obtain the desired desired liquid prepolymer. Incidentally, instead of ethers, ketones or aromatic hydrocarbons, for example ethanol.

When an alcohol such as isopropyl alcohol is used as a polymerization solvent, the crosslinked polymer precipitates as a solid during polymerization, making it impossible to produce a liquid prepolymer. Also,
When polymerization is carried out in a halogenated carbon such as chloroform or carbon tetrachloride, the halogenated carbon acts as a terogen, so the prepolymer produced is AGA.
C The excellent properties originally possessed by the resin are lost. Typical examples of ethers and ketones preferably used in the present invention include tetrahydrofuran, 1,3-dioxane,
1.Alicyclic ethers such as 4-dioxane and epidylhydrin; Aliphatic ethers such as ethyl ether, butyl ether, inbutyl ether, furoyl ether, ethylene glycol dimethyl ether, ethylene glycol monomethyl ether, and propylene glyfur dimethyl ether; Ethers such as aromatic ethers such as anisole and phenethole, and alicyclic ketones such as cyclohexanone and cyclopentanone; 7 setones.

Ketones such as aliphatic ketones such as methyl ethyl ketone, 2-pentanone, 3-hexanone, methyl imbutyl ketone, aromatic ketones such as 2-acetophenone and propiophenone, and generally carbon atoms within 4 such as toluene, xylene, and benzene. Examples include aromatic hydrocarbons substituted with a furkyl group, and it is possible to use one type of these or a mixture of one or more types of solvents.

Incidentally, although the amount of the polymerization solvent used as described above cannot be determined unconditionally,
The amount is generally 10 to 2000 parts by weight.

In other words, if the amount of solvent used is less than the above 10 parts by weight, the polymerization rate of the prepolymer increases and the viscosity increases significantly, making it difficult to put it into practical use. In some cases, gelation may occur and the prepolymer production becomes impossible. Furthermore, if the amount of the solvent is more than 2000 parts by weight, a large amount of radical initiator is required to sufficiently increase the polymerization rate of the monomer, and this is not suitable for industrially producing prepolymers.

The polymerization reaction of the present invention is generally carried out in the presence of a radical polymerization initiator. The polymerization reaction proceeds only by heating, but it can also be carried out by irradiation with actinic rays such as ultraviolet rays and radiation. The above radical polymerization initiator is not particularly limited, and known ones can be used. Examples of typical radical polymerization initiators include benzoyl peroxide, P
-Chlorbensil peroxide, 2,4-dicurpenzoyl peroxide, decanoyl peroxide.

diacyl peroxides such as launoyl peroxide and 7 cetyl peroxide, diisobutyl peroxydicarbonate, disecanda, and leptyl peroxydicarbonate.

These include bar carbonates such as di-2-ethylhexyl peroxydicarbonate, furkyl peresters such as t-butylperoxy 2-ethylhexanate and t-butylperoxybivalate, and azo compounds such as 7-zobiswintinitrile. The amount of the radical polymerization initiator to be used varies depending on the type of polymerization solvent, i, etc., and cannot be determined unconditionally, but it is generally used for unsaturated polymers containing AGAC.
It is preferable to use 0.1 to 10 parts by weight per 00 parts by weight.

In the polymerization method of the present invention, 50 to 15
A liquid prepolymer can be produced by heating at a temperature of 0° C. until a substantially saturated polymerization rate is reached, and then removing the solvent by distillation or washing with water. In addition, depending on the type of solvent used during the polymerization, it is also possible to carry out the polymerization under increased pressure or reduced pressure. Polymerization temperature has a large effect on the storage stability of the produced prepolymer. Although it depends on the type of radical initiator used, the decomposition rate of the radical initiator is generally slow at temperatures below 50°C (it takes a very long time to complete polymerization, and heating time is insufficient). In this case, radical species may remain in the prepolymer produced, which may cause an increase in viscosity and gelation during storage.
A temperature higher than 0.degree. C. is not preferable because the produced prepolymer may be colored or thermal polymerization may proceed.

Furthermore, in carrying out the method of the present invention, the monomer containing a predetermined amount of a radical initiator is heated in the solvent, and after reaching a saturated polymerization rate, the monomer is heated at that temperature for at least 1 hour. It is desirable to further heat the above to decompose trace amounts of the radical initiator. Note that this heat treatment does not cause the polymerization reaction to proceed, so the quality of the obtained polymer is hardly affected.

(Effects of the Invention) Generally, in order to obtain a suitable liquid prepolymer, it is necessary to stop the polymerization before the prepolymer obtained by low polymerization of monomers gels. Furthermore, when a liquid prepolymer is subjected to cast polymerization, it is preferable to increase the polymerization rate of the liquid prepolymer in order to prevent leakage from casting, to prevent gasket swelling, and to prevent shrinkage due to one polymerization. On the other hand, in order to facilitate deaeration of the liquid prepolymer after cast polymerization, the viscosity of the liquid prepolymer is preferably low. Therefore, it is generally desirable that the desired liquid prepolymer have a viscosity of 15 to 150 mm.

According to the present invention, there is no fear of gelation even if the polymerization rate is increased, and a desired liquid prepolymer can be easily obtained.

In addition, the liquid prepolymer obtained by the present invention does not gel even if left at room temperature for several months, and there is almost no increase in viscosity (it is stable and can be stored for a long period of time.Furthermore,
By subjecting the liquid prepolymer obtained according to the present invention to cast polymerization, the problems of swelling, single polymerization contraction, and single polymerization strain of a pounded duck can be resolved, and a good AGAC polymer molded product can be obtained.

EXAMPLES In order to explain the present invention more specifically, Examples will be given below, but the present invention is not limited to these Examples VC. The various physical properties of the prepolymers obtained in the Examples were measured using the following test methods.

(1) Viscosity (abbreviated as η) Viscosity at 25°C was measured using a Cannon-Fenske viscometer.

(2) Ratio ft (abbreviated as d) Using a standard specific gravity needle, the specific gravity at 20"C was measured.

Examples 1 to 7 Di-3 thylene glycol bis(allyl carpone)) 60
I! was dissolved in Solvent 300II shown in Table 1, 0.60 p of diimbropylpaosydi carbonate was added, and after polymerization for 3 hours at the polymerization temperature shown in Table 1, 6# & was depressurized. The prepolymer was obtained by distillation. The properties of the prepolymer are shown in Table Jc1. In addition, 30% of the produced prepolymer
The viscosity after standing for one month at ℃ is also shown in Table 1.

Comparative Example 1 Diethylene glycol bis(7lyl carbonate) 60
．． p was dissolved in 300 g of isopropyl alcohol, 0.60.9 g of diisopropyl peroxydicarbonate was added, and the mixture was polymerized at 80° C. for 3 hours. A white solid polymer precipitated in the system during polymerization, making it impossible to obtain a liquid prepolymer.

Examples 8 to 13 Diethylene glycol bis(allyl carbonate) 60# was added to a three-bottle flask equipped with a reflux condenser with predetermined amounts of 1,4-dioxane and diisopropyl peroxydicarbonate listed in Table 2. was added, heated by about 20°C to 100°C, and polymerized at this temperature for 3 hours. Thereafter, the solvent was distilled off under reduced pressure to obtain a diethylene glycol bis(allyl carbonate) prepolymer. The properties of the obtained prepolymer are shown in No. 24. Table 2 also shows the viscosity of the obtained prepolymer after it was left at 30° C. for one month.

82 Table Note) IPP diisopropyl baroxydicarbonate Example 14 Diethylene glycol bis(7lyl carbonate)) 61
1 was dissolved in 30011 liters of 1,4-dioxane, 0.601 liters of benzoyl peroxide was added thereto, and the mixture was polymerized at 100° C. for 4 hours with stirring.

Thereafter, 1,4-dioxane was distilled off under reduced pressure.

The properties of the obtained prepolymer were as follows, and they remained almost unchanged even after one month.

Specific gravity: 1.184 (20°C) Viscosity: 103 cps (25°C) Examples 15 to 17 Diethylene glycol bis(allyl carbonate) 54
．． 9 and 6 g of the monomers shown in Table 3 were added to 1,4-dioxane 3
0.30 F of diimpropylperoxydicarbonate was added thereto, and the mixture was heated at 100° C. with stirring for 3 hours, and then 1,4-dioxane was distilled off under reduced pressure. The physical properties of the obtained prepolymer are shown in Part 3. Table 3 also shows the viscosity after standing at 30° C. for one month.

Table 3 Example 18 Diethylene glycol bis(allyl carbonate) 60
．． 9 with 150g of 1,4-dioxane and 150I of benzene
0.60I of diisopropyl peroxydicarbonate was added to the mixture, and the mixture was polymerized at 80°C for 3 hours. The solvent was then distilled off under reduced pressure to obtain a prepolymer of diethylene glycol bis(allyl carbonate). Obtained. The physical properties of this product are as follows, and they remained almost unchanged even after one month.

Specific gravity (d), 1.172 Viscosity (η), 43 cps Example 19 Fuchlene glycol bis(7lyl carbonate) 60
I was dissolved in 300p of 1,4-dioxane, and
Add 0.60I (Ville Carbonais) and heat at 100°C.
After polymerization for a period of time, the solvent was distilled off under reduced pressure to obtain a prepolymer of propylene glycol bis(allyl carbonate). The physical properties of this product were as follows.

Specific gravity (d), 1.164 Viscosity (η), 18cps

Claims (2)

[Claims] (1) After polymerizing an unsaturated monomer mainly composed of alkylene glycol bis(allyl carbonate) in at least one solvent selected from the group of ketones, ethers, and aromatic hydrocarbons, A method for producing a liquid prepolymer, characterized by removing the solvent. (2) The manufacturing method according to claim 1, in which diethylene glycol bis(allyl carbonate) is used as the alkylene glycol bis(allyl carbonate).