JPS58171408A - Preparation of transparent resin having high refractive index - Google Patents

Abstract

PURPOSE:To obtain a colorless transparent resin having a high refractive index, by polymerizing a specific acrylic acid type monomer having an aromatic ring and another monomer in the presence of tert-butyl peroxyneodecanate as a polymerization initiator. CONSTITUTION:(A) One or more monomers selected from diacrylates and dimethacrylates having an aromatic ring, e.g. 1,4-dimethacryloxybenzene, in an amount of 10-100wt%, preferably 20-100wt%, based on (B) a radically polymerizable monomer, e.g. styrene, are mixed with the component (B), and the resultant mixture is then polymerized in the presence of (C) tert-butyl peroxyneodecanate as a radical polymerization initiator. Preferably, the component (C) has >=95% purity without containing a diluent and is used in an amount within 0.01-10wt% range based on the components (A) and (B).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing a high refractive index transparent resin. Conventionally, various studies and proposals have been made regarding synthetic resins to replace inorganic glass. Among them, compared to linear polymers such as methyl methacrylate and I-licarnate, the polymer of diethylene glycol bis(allyl cargenate) has a crosslinked structure, which improves its mechanical properties, chemical resistance, and resistance to cutting and polishing. Although it has excellent processability and can be used as an optical lens, its refractive index is small and its use as a lens is limited.

On the other hand, polymers having a higher refractive index than K have been proposed, such as in JP-A-53-137117. Currently known transparent polymers having a high refractive index, such as those having a refractive index of i, so or higher, generally have an aromatic ring. The monomer for providing such a polymer is one having both an aromatic ring and a vinyl group, and for the purpose of providing a crosslinked structure, a monomer having 0 vinyl groups is preferable.

Among them, acrylic esters or methacrylic esters having aromatic rings have physical properties close to those of inorganic glass, and are light in weight, making them useful not only for plate glass, dustproof glass, windshield glass, but also for lenses, prisms, etc. It is expected to be used as optical glass. However, it has an aromatic ring and U acrylic acid groups (-0COC) l = C
H2) or methacrylic acid group (-0COC(CH,) =
CH,) wo7) mo/? - (hereinafter referred to as diacrylate or dimethacrylate having an aromatic ring) and a monomer capable of radical polymerization, a pale yellow coloration occurs for unknown reasons.

Such coloring is a fatal defect when used as an organic glass as described above.

The present inventors have conducted various studies on how to prevent the above-mentioned coloring, and after much trial and error, they have found that this is due to the influence of the polymerization initiator, and as a result of further research, they have completed the present invention.

That is, the present invention uses tertiary-butyl t4 as a radical polymerization initiator in polymerizing at least 4/all monomers selected from diacrylates and dimethacrylates having an aromatic ring and a radically polymerizable monomer. - A method for producing a high refractive index transparent resin, characterized by using oxyneodecanate.

Diethylene glycol bis(allyl carbinate), which is the most commonly used polymer as conventional organic glass, is produced by slowly polymerizing at a relatively low temperature using diisoderopyrnooxydicarbonate as a polymerization initiator. The polymer has been changed. However, polymerization of at least one type of hetamine selected from diacrylates and methacrylates having an aromatic ring and a radically polymerizable bottle monomer 1. That is, in the polymerization system of the present invention, a large number of polymerization initiators, such as λ, including the diisozorobyrno-oxydicargenate, cause pale yellow coloring in the polymerization with peroxides.

However, the polymer obtained by the present invention is colorless and transparent and can be used for various purposes, and is particularly suitable for use in lenses or prisms of microscopes, cameras, glasses, etc., and glasses such as dustproof glass and windshield glass.

This shield will be explained in detail below.

Dimethacrylates and diacrylates having an aromatic ring used in the present invention are not particularly limited, and known ones can be used.

Typical examples that are generally preferably used include, for example, l, dimethacryloxybenzene, /, 4'-dimethacryloxy2.3. S, A-tetrabromobenzene, /, 1-diacryloxyethoxybenzene, /, <
1'-dimethacrylicyetoxico, 3. ,s,ls
-tetrachlorpenze/, dimethacrylate (lI
-chloro, lophenyl)methane, di(co-acryloxyethyl) heptalate, di(co-acryloxyethyl) tetraglomphthalate, 2.2bis(dermethacryloxyphenyl)pro/9-one, 2.2 bis(tI-acryloxy-3,S-dichlorophenyl)
Gronoyan, 2.2bis(lI-methacryloxy-3-
Bromphenyl)propane, 2. Cobis (dermethacryloxy 3,5-dibromphenyl)furo/dan 1.2
, 2bis(coumethacryloxy-3-iodophenyl)furo/dan, 2.2bis(lI-methacryloxyethoxyphenyl) f a /#n, 2.2bis(lI-
(methacryloxyethoxy-3,S-dibromphenyl)
Flo/Dan, 2. , tbis<ti-methacryloxypolyethoxyphenyl)furo/dan, 2, cobis(゛μm
Methacryloxypolyethoxy-3s S-/F mouth・
Mphenyl) Furo/Dan, i, s-dimethacryloxinaf! Ren, i, s'-diacrylate-2,11,A,
g-tetrachlornaphthalene, l,5-dimethacrylokijetoxy-, 2, tI.

Otsu 91g - Tetratetrachlornaphtha Len.

t-Tetrachlor7talene, 22bis(4t-methacryloxyethoxyphenyl,)sulfone, 22bis(II
-methacryloxyethoxyphenyl)methane, and mixtures thereof.

Among these, when a particularly high refractive index is required, it is preferable to use dimethacrylate or diacrylate having a nuclear halo-substituted aromatic ring. Bromine is particularly preferable as the halogen. The number of halodane substituted into the aromatic ring is not particularly limited, and 1-da can be used.

First, the radically polymerizable monomer used in the present invention is not particularly limited, and known monomers can be used, including the above-mentioned aromatic ring-containing diacrylates and dimethacrylates.

The monomers to be used are monomers for mechanical properties when dimensional stability is important, and monomers for fimic performance when high refractive index is required, for example, monomers with aromatic rings for dyeing. Depending on the intended use of the resulting copolymer, the monomer having an I-oxy group may be selected as appropriate. Of course, it is optional to select multiple types of monomers in order to satisfy these multiple performances. Typical examples of functional monomers commonly used in droplets include:
Styrene, vinyltoluene, methoxystyrene, chlorstyrene, bromustyrene, iodostyrene dichlorostyrene, dibromustyrene, trichlorostyrene, tribromustyrene, styrene derivatives such as P-styryltrimethyl 7rane, phenyl methacrylate, phenyl acrylate, cool phenyl Acrylate, dichlorophenyl methacrylate, bromphenyl acrylate,
Dibuq phenyl methacrylate, pentabromphenyl methacrylate, methoxyphenyl methacrylate/! JL/-t, benzyl methacrylate, chlorobenzol acrylate, bromobenzyl methacrylate, pentabromphenyl methacrylate, methyl methacrylate, ethyl methacrylate, co-hydroxyethyl methacrylate,
Glycidyl methacrylate, allyl methacrylate, α
- trimethylsilane, methyl lylacrylate, methacryloyloxyethoxytrimethylsilane acrylate,
Naphthalene derivatives such as methacrylates, l-vinylnaphthalene, 2-vinylnaphthalene, α-naphthyl methacrylate, β-naphthyl methacrylate, α-naphthyl acrylate, vinyl-α-naphthylphenylsilane,
Other vinyl compounds such as vinyl acetate, acrylonitrile vinyltriethoxysilane, and vinyltrimethylsilane; polyfunctional monomers include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate,
Aliphatic acrylates such as trimethylol 7'o pantriacrylate, triethylene glycol diacrylate, tetrametherol pronotrimethacrylate,
Diallyl compounds such as methacrylates, sialyl 7-thalerate, diallyl iso-7-thalerate, ethylene glycol, bis(allyl carnate), diallyl tartrate, diallyl xysuccinate, diallylphenylsilane, diallyldimethylsilane, etc., and mixtures thereof. .

Furthermore, it can be selected from the acrylates having an aromatic ring and the methacrylates having an aromatic ring, although the ratio of the monomer selected from the diacrylate acrylates having an aromatic ring to the radically polymerizable monomer cannot be absolutely limited. ,7
A range of 0 to 100% by weight, preferably 20 to 100% by weight is common.

Therefore, the composition ratio of the two components in the present invention is preferably determined in advance depending on the required physical properties such as mechanical properties and refractive index.

In the present invention, the method for producing a high refractive index transparent resin is to use tert-butyl 9-oxyneodeca as a radical polymerization initiator, using dimethacrylates and diacrylates having an aromatic ring, and a monomer capable of radical polymerization as a radical polymerization initiator. obtained by polymerization in the presence of nates. The general structural formula of the polymerization initiator is shown by (1).

Here R1 is CH1 or ac2H, the group R1 is CH, or FiC, H, the group R, Fi04H, '11H11 or c4H1j group. In the present invention, a mixture consisting of one or more compounds represented by the above general formula can be used.

The tert-butyl oxyneodecanate used in the present invention must have a purity of at least 95- or higher.

Additionally, kernels that are essentially free of diluent are also required.

If a diluent is included, air bubbles will be generated in the molded product during polymerization, and the surface of the molded product will become rough, reducing its commercial value.

The amount of the radical polymerization initiator to be used varies depending on the polymerization type, polymerization conditions, type of monomer for the copolymerization component, etc., and cannot be absolutely limited, but it is generally 70.
It is most preferable to use it within the range of /~/θ゛ (weight t).

In the present invention, the method of polymerizing at least seven monomers selected from cyacrylates and dimethacrylates having an aromatic ring and a radically polymerizable monomer is not particularly limited, and any known polymerization method can be employed.

An example of a typical polymerization method is a cast polymerization method. For example, a mixture of the polymerization component monomers containing a radical polymerization initiator is injected between molds held by an elastomer gasket or spacer, polymerized and cured in a heating oven, and then taken out. Of course, it is also possible to preliminarily polymerize a mixture of polymerization component monomers in the presence of a polymerization initiator to increase the viscosity of the mixture, and then perform cast polymerization.

Among the polymerization conditions, temperature in particular has an effect on the properties of the transparent resin. give. -Finally, it is preferable to carry out so-called 4-polymerization, in which polymerization is started slowly at a relatively low temperature and cured at a high temperature when the polymerization is completed.

For example, it is preferable to start polymerization slowly at about 20°C to lI0°C, gradually raise the temperature, and terminate the polymerization at a high temperature of about gθ -/20°C.

In particular, when the objective is to obtain a thick high refractive index transparent resin, it is preferable to lengthen the polymerization time at a low temperature or to perform the preliminary polymerization described above.

However, if the polymerization time is too long, especially at a high temperature, the resin will be colored pale yellow and the effect of the polymerization initiator of the present invention will be lost. is not desirable.

Generally, it is preferable to select conditions such that copolymerization is completed in 5 to 30 hours. Since the polymerization time varies depending on various conditions, it is preferable to determine the optimum conditions in advance according to these conditions.

Of course, during the polymerization, additives such as release agents, ultraviolet absorbers, antioxidants, anti-coloring agents, antistatic agents, fluorescent dyes, and various stabilizers may be selected and used as necessary. I can do it.

In order to explain the present invention more specifically, Examples and corresponding comparative examples are shown below. From these results, the present invention. It will be easily understood that the resin polymerized using the tertiary butyloxyneodecanate polymerization initiator is a colorless and transparent resin with a high refractive index. Of course, the present invention is not limited to these Examples. The various physical properties of the high refractive index transparent resins obtained in the Examples were measured by the following test methods.

(11 Refractive index (no) The refractive index at 20° C. was measured using an Atsube refractometer. Motupromnaphthalene was used as the contact liquid.

121 transmittance (Ttchi) Measured using a fade meter.

(31 Pale yellow coloring - (hue), b
(chroma) was measured.

The larger the a and b values, the greater the yellow coloration.

Examples 7 to 3 110 parts by weight of styrene and 6 cobis(dermethacryloxyethoxy 3,5-dibromphenyl)pronomones 6
0 parts by weight were dissolved. next! /Tertiary-butyl-oxyneodecanate (purity 99%) with the composition shown in the table.
) and mix well.

This mixed solution was injected into a mold consisting of a glass plate with a diameter of 3I1ml+ and a gasket made of ethylene-vinyl acetate copolymer, and cast polymerization was carried out using an air heating furnace at 25°C. Polymerization was started, and the temperature was gradually raised to 90°C after 25 hours. Further 90℃
After polymerizing for 2 hours at 700° C., the polymer was taken out from the gasket and mold, and polymerized at 700° C. for 2 hours. The polymer was colorless and transparent. The physical properties of the polymer were measured and shown in Table 1.

Comparative Examples/-/, f; In place of Examples/--, the polymerization initiators shown in Table 1 were added in the compositions shown in Table 1. All others <Example 1~
It was carried out in the same manner as in 3.

For reference, the properties of Tsuku oxide are shown in Table 2.

From the results in Tables 1 and 2, tertiary butyl, 4
- It is easily understood that oxyneodecanate specifically penetrates the colorless and transparent high refractive index resin.

The thickness of this effect of tertiary butyl peroxyneodecanate does not depend on the decomposition temperature of the peroxide, and is completely unknown.

Example II-A Styrene and cocobis (lI-methacryloxyethoxy-
3,5-dibromphenyl)pro/Danwo was mixed with the composition shown in Table 3, 7 parts by weight of tert-butyl peroxyneodecanate (purity 9t%) was added as a polymerization initiator, and the rest was as in Example 1. The same procedure was carried out. The results are shown in Table 3.

Comparative Example 16 In Example D, the polymerization initiators shown in Table 3 were used. The rest was carried out in the same manner as in Examples tl-6.

The results are shown in Table 3.

Example 7~ // Casting polymers of various compositions were produced by the same means as in Examples 7~3, and the results are shown in Table D as Examples and Comparative Examples. As is clear from Table 3, it is clear that the resin of the present invention is colorless and transparent compared to the comparative example.

Claims (1)

[Claims] In polymerizing at least 7 monomers selected from diacrylates and dimethacrylates having an aromatic ring and a monomer capable of radical polymerization, tertiary-butyl/#-oxyneodecanate is used as a radical polymerization initiator. A method for producing a high refractive index transparent resin.