IT9020432A1 - POLYMERIZABLE LIQUID COMPOSITION IN ORGANIC GLASSES WITH LOW COLOR AND HIGH REFRACTION INDEX - Google Patents

Description

DESCRIPTION of the industrial invention entitled:

"Polymerizable liquid composition in organic glasses with low color and high refractive index"

SUMMARY

A polymerizable liquid composition in organic glasses with low color and high refractive index contains:

(A) from 20 to 80% by weight of a mixture of monomer and oligomers of an allyl carbonic derivative which can be represented by the formula (I):

and where: X = hydrogen or halogen (excluding fluorine);

a and b are integers independently equal to 1 or 2;

n assumes values from 1 to 5, with the condition that at least 10% by weight of the mixture consists of oligomeric allyl carbonic derivatives (n> 1);

(B) from 80 to 20% by weight of a liquid monomer copolymerizable with component (A), selected from diallyl isophthalate, diallyl terephthalate, triallyl cyanurate and triallyl isocyanurate; And

(C) from 0.3 to 1 part by weight, for every 100 parts by weight of the sum of components (A) and (B), of cyclopentene or an alkyl cyclopentene, where the alkyl group, linear or branched, contains from 1 to 10 carbon atoms.

DESCRIPTION

The present invention relates to a polymerizable liquid composition in organic glasses with a low color and a high refractive index. The invention also relates to organic glasses obtained from said polymerizable composition.

In the organic glass sector, the products of the polymerization of bis (allyl carbonates) of diethylene glycol are interesting and this in view of their optical and mechanical characteristics that make them useful in the preparation of optical articles (F. Strain; "Encyclopedia of Chemical Processing and Design ", Vol.

1, Interscience Publishers, New York, 1964, pp. 799 and following.

However, in the preparation of optical articles from such polymerizates relatively higher thicknesses are required than those of inorganic glass articles and this due to the relatively low values of the refractive index typical of the polymerizates themselves. This is disadvantageous from the point of view of the weight of the manufactured article, of the loss of aesthetic characteristics and of the difficulties in obtaining articles of high optical quality with high thickness.

Therefore, in order to overcome these problems, compositions suitable for forming polymerizates having a relatively high refractive index have been developed in the art. In the context of allyl carbonic derivatives, these compositions of the known art generally comprise polymerizable monomers endowed with an aromatic portion, such as bis (allyl carbonates) of bisphenols and related ethoxylated derivatives, which can also be used in halogenated form, especially brominated. Representative of this prior art is U.S. Pat. 4,622,376; CA 105 7576n (Japan patent application 60-231.712); CA 1057577p (Japan patent application 60-231.7134) and CA 10580818h (Japan patent application 61-23.567).

In the Italian patent application No. 21,440 A / 89, filed on 3 August 1989, in the name of the Applicant, a polymerizable liquid composition is described containing a polyfunctional allyl liquid monomer and a mixture of monomer and oligomers of bis (allyl carbonate) of bisphenol A halogenated and oxyethylated. This composition can be transformed, by polymerization, into organic glasses with a high refractive index, additionally endowed with good values of impact resistance and good workability. It has now been found that it is possible to improve the color of the organic glasses obtainable from the composition of the aforementioned Italian patent application, even when said composition contains bis (allyl carnonates) in their non-halogenated form, by including small quantities in the composition itself. of cyclopentene or its alkyl derivative. It has also been found that such an improvement in color is unexpectedly good and not obtainable by means of other monomers of the known art, such as for example the cyclohexene compounds described in the European patent application 224.123 or other similar monomers.

In accordance with this, the present invention relates to a liquid composition polymerizable in organic glasses with low color and high refractive index, which comprises:

(A) from 20 to 80% by weight of a mixture of monomer and oligomers of an allyl carbonic derivative which can be represented by the formula (I):

and where: X = hydrogen or halogen (excluding fluorine);

a and b are integers independently equal to 1 or 2;

n assumes values from 1 to 5, with the condition that at least 10% by weight of the mixture consists of oligomeric alkyl carbonic derivatives (n> 1);

(B) from 80 to 20% by weight of a liquid monomer copolymerizable with component (A), selected from diallyl isophthalate, diallyl terephthalate, triallyl cyanurate and triallyl isocyanurate; And

(C) from 0.3 to 1 part by weight, for every 100 parts by weight of the sum of components (A) and (B), of cyclopentene or an alkyl cyclopentene, where the alkyl group, linear or branched, contains from 1 to 10 carbon atoms.

In the preferred embodiment, the composition of the present invention contains from 35 to 65% by weight of a component (A) with formula (I) where X is bromine, a and b are equal to 1; and the content of oligomers (n> 1) varies from 15 to 50% by weight; from 65 to 35% by weight of component (B); and from 0.3 to 1 part by weight, for every 100 parts by weight of the sum of components (A) and (B), of a component (C) selected from cyclopentene and methyl cyclopentene.

Component (A) of the composition of the present invention can be conveniently obtained by means of a transesterification reaction between the suitable diol and diallyl carbonate, in the presence of a basic catalyst, operating for example according to the general lines of the transesterification process described in the European patent N. 35.304. By operating under these conditions, a mixture of allyl carbonic derivatives monomer (n = 1) and oligomers (n> 1) is obtained, according to formula (I), in proportion to each other which varies according to the ratio between the reactants. In particular, component (A), useful in the composition of the present invention, can be obtained by transesterification of diallyl carbonate and the diol [preferably 2,2-bis (4-hydroxyethoxy-3,5-dibromo phenyl) propane] in molar ratio between them less than about 20/1 and preferably in the range from 12/1 to 4/1.

Still in the preferred embodiment, the composition of the present invention contains from 0.05 to 0.2 parts by weight, for every 100 parts by weight of the sum of components (A) and (B), of a light absorbing agent ultraviolet (UV absorber) selected in the class of hydroxybenzophenones and from 0.05 to 0.3 parts by weight, for every 100 parts by weight of the sum of components (A) and (B), of an amine selected from aliphatic amines and sterically hindered amines (HALS).

Examples of hydroxybenzophenones suitable for the purpose are 2,4-dihydroxy benzophenone, 2-hydroxy-4-methoxy benzophenone, 2-hydroxy-4-n-octyloxy benzophenone, 2-hydroxy-4-isooctyloxy benzophenone, 2-hydroxy-4-dodecyl oxy benzophenone, 2,2'-dihydroxy-4-methoxy benzophenone, 2,2 ', 4,4'-tetrahydroxy benzophenone and 2-hydroxy-4-methoxy-5-sulfo benzophenone. Examples of commercial hydroxybenzophenones, suitable for the purpose, are those marked with the following brands: Chimassorb 90, Advastab 48, Chimassorb 81, Chimassorb IL5, Uvinul D50 and Uvinul 400.

Examples of aliphatic amines and sterically hindered amines suitable for the purpose are triethyl amine, Ν, Ν-dimethyl ethanol amine and the derivatives of tetraalkyl, especially tetrameters, piperidine. Examples of commercial products suitable for this purpose are those marked with the following brands: Tinuvin 770, Tinuvin 662, Spinuvex A36, Chimassorb 944, Hostavin N-20, Goodrite 3034 and Cyasorb UV 3346.

The addition of the hydroxybenzophenones and the aliphatic amines or sterically hindered amines to the compositions of the present invention allows to significantly increase the resistance to aging and this without worsening the initial coloring of the polymer and without reducing its hardness.

The composition of the present invention also contains a polymerization initiator in an amount from 2 to 8 parts by weight for every 100 parts by weight of the sum of components (A) and (B). Such an initiator is soluble in the composition itself and is capable of generating free radicals in a temperature range from about 30 to about 100 ° C. Non-limiting examples of such initiators are organic peroxide initiators and percarbonates and particularly diisopropyl peroxy dicarbonate, dicyclohexyl peroxy dicarbonate, di-sec-butyl peroxy dicarbonate, dibenzoyl peroxide and tert-butyl perbenzoate. In the preferred embodiment of the present invention, the polymerization initiator is present in the composition in quantities from 3 to 5 parts by weight for every 100 parts by weight of the sum of components (A) and (B).

The polymerizable liquid composition of the present invention can additionally contain one or more conventional additives such as detaching agents, dyes, pigments, infrared light absorbers and the like in an overall quantity in any case not exceeding 1 part by weight for every 100 parts by weight of the sum of the components. (A) and (B).

The polymerizable liquid composition of the present invention is transformed into optical articles by means of the polymerization process in the mold (casting). The polymerization is initiated by the free radicals generated by the decomposition of the polymerization initiators added to the composition itself, generally operating at temperatures from 35 to 100 ° C. Under these conditions, the times required for complete polymerization range from 2 to 100 hours. The articles thus obtained have a high refractive index, an extremely low color and a good resistance to aging, as will be evident from the following experimental examples, which are reported to better illustrate the present invention.

In said examples the polymerizable liquid compositions are prepared, the dicyclohexyl peroxy dicarbonate polymerization initiator is added and the resulting compositions are subjected to polymerization in glass molds assembled with a flexible gasket of plasticized polyvinyl chloride, which determines the thickness of the polymeric product. The polymerization takes place in a forced circulation oven, with a polymerization cycle lasting 20 hours, with a temperature that rises from 40 to 80 ° C.

The following characteristics are determined on the hardened samples:

Refractive index (nD20), measured with Abbe refractometer (ASTM D-542);

Haze (%) and visible transmittance, measured with Gardner Hazegard XL-211 (ASTM D-1003);

Yellow Index (YI) defined as:

YI = (100 / Y) (1.277X - 1.06Z), measured with Gardner's XL-805 colorimeter (ASTM D-1925);

Rockwell hardness (M), measured with Rockwell durometer (ASTM D-785);

Resistance to aging, evaluated for continuous exposure in Weather O Meter (WOM) equipped with a 6,500 W xenon lamp; the results are expressed as an increase in yellow index (Delta YI) determined after 150 hours of exposure at 62 ° C on the black panel and at a relative humidity of 50%.

Furthermore, the following components (A) are used in the liquid compositions in the following examples:

(Al) product of the transesterification of diallyl carbonate and 2,2-bis (4-hydroxyethoxy-3,5-dibromophenyl) propane, in a molar ratio of 12/1, corresponding to formula (I) with X = bromine ; a = b = 1; n = 1.10 (mean value); content of oligomers (η> 1) = 17% by weight;

(A2) product of the transesterification of diallyl carbonate and 2,2-bis (4-hydroxyethoxy-3,5-dibromophenyl) propane, in a molar ratio of 8/1, corresponding to formula (I) with X = bromine ; a = b = 1; n = 1.15 (mean value); content of oligomers (η> 1) = 25% by weight; And

(A3) product of the transesterification of diallyl carbonate and 2,2-bis (4-hydroxyethoxy-3,5-dibromophenyl) propane, in a molar ratio of 4/1, corresponding to formula (I) with X = bromine ; a = b = 1; n = 1.35 (mean value); content of oligomers (η> 1) = 45% by weight.

Examples 1-3.

Three liquid compositions are prepared containing respectively the components (Al), (A2) and (A3) described above. Diallyl isophthalate is used as component (B) and cyclopentene is used as component (C). The quantities by weight of the constituents of the compositions are reported in Table 1 below.

Table 1

The compositions are added with cyclohexyl peroxy dicarbonate, as polymerization initiator, in a quantity of 3.5 parts by weight for every 100 parts by weight of the composition and are subjected to polymerization in flat sheets with a thickness of 3 mm, operating according to the methods indicated in the description. The characteristics which are reported in table 2 are determined on the plates thus obtained. In the table the numbers reported in brackets indicate (for comparison purposes) the characteristics of the plates similarly obtained, but starting from compositions without component (C).

Table 2

Example N. YI Rockwell hardness (M) p

For comparison purposes, two tests are also carried out according to Example 3 above, replacing component (C) with 0.5 parts by weight of cyclohexene (test I) and with 1.0 parts by weight of cyclohexene (test II) . Table 3 below shows the characteristics of the slabs obtained.

Table 3

Example 4 (Comparison).

For comparison purposes, compositions similar to that of Example 2 are prepared, but containing, as component (C), 0.5 parts by weight of the following cyclic olefins:

norbornadiene NB

cis, cis-1,5-cyclooctadiene COD

cyclooctene CO

cyclopentadiene CP

4-vinyl-1-cyclohexene VC

These compositions are polymerized, under the same conditions as the previous examples, into flat sheets with a thickness of 3 mm, the characteristics of which are reported in the following table 4.

Table 4

Examples 5-7.

Three compositions are prepared containing 50 parts by weight of component (A2), 50 parts by weight of diallyl isophthalate as component (B), 0.5 parts by weight of cyclopentene as component (c) and the following other constituents listed in table 5 , together with their quantity by weight.

Table 5

Chimassorb 90 = 2-hydroxy-4-methoxy benzophenone; commercial product of the Ciba-Geigy company;

Tinuvin 622 = sterically hindered amine, commercial product of the Ciba-Geigy company;

Tinuvin 770 = sterically hindered amine, commercial product of the Ciba-Geigy company.

These compositions are transformed into flat sheets with a thickness of 5 mm, with the usual methods and the characteristics of these sheets are reported in table 6.

Table 6

Examples 8-12.

Five compositions are prepared containing 50 parts by weight of component (A2), 50 parts by weight of diallyl isophthalate as component (B), 0.5 parts by weight of cyclopentene as component (C) and the following other constituents listed in table 7 , together with their quantity by weight.

Table 7

These compositions are polymerized, under the same conditions as the previous examples, into flat sheets with a thickness of 5 mm, the characteristics of which are reported in the following table 4.

Table 8

Claims (9)

CLAIMS 1. Polymerizable liquid composition in organic glasses with low color and high refractive index, characterized in that it comprises: (A) from 20 to 80% by weight of a mixture of monomer and oligomers of an allyl carbonic derivative which can be represented by the formula (I): and where: X = hydrogen or halogen (excluding fluorine); a and b are integers independently equal to 1 or 2; n assumes values from 1 to 5, with the condition that at least 10% by weight of the mixture consists of oligomeric allyl carbonic derivatives (n> 1); (B) from 80 to 20% by weight of a liquid monomer copolymerizable with component (A), selected from diallyl isophthalate, diallyl terephthalate, triallyl cyanurate and triallyl isocyanurate; And (C) from 0.3 to 1 part by weight, for every 100 parts by weight of the sum of components (A) and (B) of cyclopentene or an alkyl cyclopentene, where the alkyl group, linear or branched, contains from 1 at 10 carbon atoms. 2. Composition according to claim 1, characterized in that it contains from 35 to 65% by weight of a component (A) with formula (I) where X is bromine, a and b are equal to 1; and the content of oligomers (n> 1) varies from 15 to 50% by weight; from 65 to 35% by weight of component (B); and from 0.3 to 1 part by weight, for every 100 parts by weight of the sum of components (A) and (B), of a component (C) selected from cyclopentene and methyl cylopentene. 3. Composition according to claim 1, characterized in that said component (A) is the product of the transesterification of diallyl carbonate and of 2,2-bis (4-hydroxyethoxy-3,5-dibromophenyl) propane] in molar ratio to each other from 12/1 to 4/1. 4. Composition according to claim 1, characterized in that it additionally contains from 0.05 to 0.2 parts by weight, for every 100 parts by weight of the sum of components (A) and (B), of an absorption agent of the ultraviolet light (UV absorber) selected in the class of hydroxybenzophenones and from 0.05 to 0.3 parts by weight, for every 100 parts by weight of the sum of components (A) and (B), of an amine selected from the aliphatic amines and sterically hindered amines (HALS). 5. Composition according to claim 4, characterized in that said ultraviolet light absorbing agents and said aliphatic and sterically hindered amines are selected from: 2,4-dihydroxy benzophenone, 2-hydroxy-4-methoxy benzophenone, 2-hydroxy -4-n-octyloxy benzophenone, 2-hydroxy-4-isooctyloxy benzophenone, 2-hydroxy-4-dodecyloxy benzophenone, 2,2'-dihydroxy-4-methoxy benzophenone, 2,2 ', 4,4'-tetrahydroxy benzophenone , 2-hydroxy-4-methoxy-5-sulfur benzophenone, triethyl amine, Ν, Ν-dimethyl ethanol amine and derivatives of tetraalkyl, especially tetramethyl, piperidine. 6. Composition according to claim 1, characterized in that it additionally contains from 2 to 8 parts by weight, for every 100 parts by weight of the sum of components (A) and (B), of a polymerization initiator, soluble in the composition itself and capable of generating free radicals in a range of temperatures from about 30 to about 100 ° C. 7. Composition according to claim 6, characterized in that the initiator is selected from diisopropyl peroxy dicarbonate, dicyclohexyl peroxy dicarbonate, di-sec-butyl peroxy dicarbonate, di-benzoyl peroxide and tert-butyl perbenzoate and is present in quantities of 3 to 5 parts by weight for every 100 parts by weight of the sum of components (A) and (B). 8. Composition according to claim 1, characterized in that it additionally contains one or more additives selected from detaching agents, dyes, pigments and infrared light absorbers, in an overall quantity not exceeding 1 part by weight for every 100 parts by weight of the sum of components (A) and (B). 9. Organic glasses obtained by polymerization in mold (casting) of the composition according to claims 1 to 8.