AU596100B2

AU596100B2 - Copolymer having high refractive index

Info

Publication number: AU596100B2
Application number: AU58023/86A
Authority: AU
Inventors: Naoya Imamura; Hisayuki Kayanoki; Yoshio Sugiyama; Motoaki Yoshida
Original assignee: Nippon Sheet Glass Co Ltd
Current assignee: Nippon Sheet Glass Co Ltd
Priority date: 1985-05-28
Filing date: 1986-05-28
Publication date: 1990-04-26
Anticipated expiration: 2006-05-28
Also published as: GB2176794B; FR2582658B1; GB8612893D0; FR2582658A1; AU5802386A; GB2176794A; KR870011159A; DE3617755A1

Description

AUSTRALIA

Patents Act LODGED AT SU8-oFICr.

P2 8 M1AY 1986 11jun COMPLETE SPECIFICATION

(ORIGINAL)

Ciass Int. Class Application Number: Lodged: ,5g'o V /7~6, 596 VOO Complete Specification Lodged: oo 'Priority 0 0 Related Art: zoo0 Accepted: Publishee: Thlis documeflt contairis the a~i~ndmeflts made under Section 49 and is correct for printing- 0 0~ 0 1 0 00>0* 0 0 Name(s) of Applicant(s): 41 APPLICANT'S REF.: K-107 (Glas) /YE NIPPON SHEET GLASS CO., LTD.

Address(es) of Applicant(s): No. 8, 4-chome, Dosohomachi, 94 Higashi-ku, Osaka, 6s* JAPAN Actual Inventor(s): NAOYA IMAMURA YOSHIO SUGIYAMA MOTOAKI YOSHIDA HISAYUKI KAYANOKI Address for Service is: PHILLIP6, -RMONDE AND FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne, Australia, 3000 Complete Specification for the invention entitled: COPOLYMAER HAVING REFRACTIVE INDEX The following statement is a full description of this invention, including the best method of performing it known to applicant(s): P19/3/84 Y1U3C 1A This invention relates to a novel copolymer, and more specifically, to a copolymer which has a high refractive index, a high Abbe number, reduced chromatic aberration, and excellent impact strength, moldability, polishability and dyeability (tintability) and is particularly suitable for production of optical lenses.

Various synthetic resins which replace inorganic glasses, particularly optical glasses, have been studied o o and proposed heretofore. For example, a polymer composed 0o o 10 of diethylene glycol bisallyl carbonate units as a main 0 ao component is in commercial use. This polymer has the 0 o00 00 advantage of light weight, safety, ease of processing and 0 0* 000 t tintability which inorganic glasses cannot satisfy, and because of its crosslinkage, its mechanical properties are 0 0, S 15 good. However, it has the defect that its refractive index is as low as about 1.50. Resins having a high refractive index with the elimination of this defect have been proposed. For example, resins containing large amounts of an t*0 aromatic ring and halogen disclosed in Japanese Laid-Open Patent Publication Nos. 166214/1981, 136309/1984, 136310/ 1984, and 28412/1985 have a high refractive index and can be processed inti lenses having a smaller thickness than conventional lenses. The reein described in Japanese Laid-Open Patent Publication No. 166214/1981, however, has a very low Abbe number of less than 35. If the Abbe number is low, the differences in refractive index depending upon wavelengths become great (highly dispersed), and are not 2 desirable in designing lenses. On the other hand, the resins described in Japanese Laid-Open Patent Publications Nos. 136309/1984, 146310/1984 and 28412/1985 has a high Abbe number, but has the defect of a low degree of crosslinkage and inferior solvent resistance.

Recently, a resin simultaneously having a high refractive index and a high Abbe number has been developed.

But its impact strength required of plastic eyeglass lenses for eyesight correction is insufficient and it has un- 10 satisfactory lens moldability by casting.

It is a principal object of this invention to provide a copolymer or resin which has a high refractive t index, low-dispersion optical characteristics, and excellent impact strength, lens moldability, polishability and tintability and is suitable for processing into optical lenses.

Another object of this invention is to provide a process for producing such a copolymer or resin.

Still another object of this invention is to provide an optical lense having a high refractive index, a high Abbe number, low-dispersion optical characteristics and excellent impact strength and tintability.

Other objects and advantages of this invention will become apparent from the following detailed description.

According to this invention, there is provided a copolymer having a high refractive index and comprising :i i i 3 1 to 90% by weight of first recurring units derived from at least one monomer represented by the formula

R

1

CH

2

=C-COO+CH

2 CH2 O--R 2

(I)

wherein R represents a hydrogen, chlorine or bromine atom or a methyl group, R represents a polycyclic aliphatic hydrocarbon group, and n a represents 0, 1, 2 or 3, t 1 to 80% by weight of second recurring units S 1 0 derived from at least one monomer containing at least two

R

3 residues CH2=C- which is an ester of an aliphatic polyhydric alcohol with an unsaturated carboxylic acid of the

R

3 1 3 formula CH2=C-COOH in which R represents a hydrogen, chlorine or bromine atom or a methyl group, and 5 to 90% of third recurring units derived from at least one radical-polymerizable monomer capable of giving a homopolymer having a refractive index of at least 1.55.

The copolymer of this invention can be produced by a process which comprises radical-copolymerizing 1 to 90% by weight of at least one monomer of formula given above (to be referred to as a first monomer),

A

I i m~ 00 0W 0 0) 0 SO 00 o *0 00 4 4e 401a 4''a 04xi 4 1 to 80% by weight of at least one monomer

R

3 containing at least two residues CH 2 which is an ester of an aliphatic polyhydric alcohol with an unsaturated carboxylic acid of the formula

R

3

CH

2

=C-COOH

in which R 3 represents a hydrogen, chlorine or bromine atom or a methyl group, 5 to 90% by weight of at least one radicalpolymerizable monomer (to be referred to as a third mono- 10 mer) capable of giving a homopolymer having a refractive index of at least 1.55, and optionally, up to 40% by weight of another radical copolymeriable monomer (to be referred to as a fourth monomer).

The copolymer of this invention will be described specifically.

First monomer The monomer from which the first recurring units of the copolymer of this invention are derived are represented by the following formula (I) t" CH 2 =-COO+CH 2

CH

2 04.-R 2 wherein R 1 represents a hydrogen, chlorine or 5 bromine atom or a methyl group, R 2 represents a polycyclic aliphatic hydrocarbon group, and n represents 0, 1, 2 or 3.

The "polycyclic aliphatic hydrocarbon group" represented by R 2 is a monovalent aliphatic hydrocarbon group containing a plurality of alicyclic rings. The alicyclic rings preferably form a fused ring having at least two ring members in common rather than they exist independently from each other. The polycyclic aliphatic hydrocarbon group may include a chain hydrocarbon moiety in addition to such a ring. Such a polycyclic aliphatic hydrocarbon group may generally contain 7 to 30 carbon n o atoms, preferably 7 to 25 carbon atoms. Specifically, the following groups may be cited as examples.

2 1 2 wherein Y and Y each represent a hydrogen, chlorine or bromine atom or a lower alkyl group, or together form an additional bond,

CH

3 and

-CH

2

CH

2 In the present specification and claims, the term "lower" used to qualify an atomic grouping or a compound means that the atomic grouping.or compound so qualified 6 contains not more than 6 carbon atoms, preferably not more than 4 carbon atoms.

The monomers of formula are described, for example, in Japanese Laid-OPen Patent Publications Nos.

.16265/1983 and 7901/1984, and are known per se. In the present invention, the monomer of formula may be selected from such known monomers.

Second monomer 60 The second monomer which gives the second recur- 10 ring units of the copolymer of this invention is a compound

R

3 containing at least two residues of the formula CH 2

C-

which is an ester of an aliphatic polyhydric alcohol with

R

3 an unsaturated carboxylic acid of the formula CH 2

=C-COOH.

The aliphatic polyhydric alcohol used in forming the above ester is a normally linear or branched compound having at least 2, preferably 2 to 8, hydroxyl groups (-OH) which may contain an etheric oxygen atom in the chain. The aliphatic polyhydric alcohol may generally have 2 to carbon atoms, preferably 2 to 60 carbon atoms. Specific examples of the aliphatic polyhydric alcohol include the following compounds to Alkylene glycols of the formula HO-R 4 -OH in which R 4 represents an alkylene group having 2 to 18 carbon atoms, preferably 2 to 15 carbon atoms. Examples include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6- 7 hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and neopentyl glycol.

Polyalkylene glycols of the formula OH in which R 5 represents an alkylene group having 2 to 10 carbon atoms, preferably 2 to 6 carbon atoms, and m represents an integer of 2 to 25, preferably 2 to 18.

Examples include polyethylene glycols such as diethylene glycol, tetraethylene glycol and nonaethylene glycol, and polypropylene glycols such as dipropylene glycol and nonapropyelne glycol.

Trihydric alcohols such as CH2- OH

H

2 -OH CH20CH 2

CH

2

OH

CH-OH CH 3

CH

2

-C-CH

2 -OR and CH 3

CH

2

-C-CH

2

CH

2

CH

2 OH CH -OH CH -OH CH 2

OCH

2

CH

2

OH

2 2 2 2 2 Tetrahydric or higher alcohols such as CH2-OH CH2-OH CH -OH 2 1 2 12

HO-CH

2

-C-CH

2 -OH and HO-CH2-C-CH 2

-O-CH

2

-C-CH

2

-OH

CH2-OH

CH

2 -OH CH 2

-OH

When the polyhydric alcohol has 3 or more hydroxyl groups, one or more of these hydroxyl groups may be protected by a lower alkanoyl group such as acetyl or propionyl, provided that at least two hydroxyl groups must be present free.

The unsaturated carboxylic acid to be reacted with the polyhydric alcohol is a compound represented by the following formula (II) 8 CH 2 =C-COOH (I I) wherein R 3represents a hydrogen, chlorine or bromine atom or a methyl group.

The esterification of the polyhydric alcohol with the unsaturated carboxylic acid may be carried out by methods known per se. Especially suitable compounds used as the second monomer in this invention are represented by the following formulae (III) to (VI).

14 CH 2 C-COO-R -OOC-C=CH 2 (111) C C

CC

C C C C CC 'C C C C C C I IC C C C C CC =C-COOfR5O+-OC-C=C

CH

2 m C1 2 CH -0-A 2 CH CH -C-CH -0O-A CH 2 -0-A 3 CH 2 -0-A 6 CH 2 -0-A 9

(IV)

MV

(VI)

In the above formulae, at least two of A1, A 2and R3 3

IW

A represent the residue CH 2 C-CO- and the remainder represents an alkanoyl group such as acetyl. or propionyl; at 4 9 1 least two of A to A represent the residue CH 2 =C-CO- and the remainder represent an alkanoyl group such as acetyl or propionyl, and R 3 R 4 R 5 and n are the same as defined above.

-9- These second monomers may be used singly or as a mixture of two or more. Examples of suitable second monomers include alkylene glycol di(meth)acrylates such as 1,9-nonanediol di(meth)acrylate and 1,6-hexanediol di- (meth)acrylate; polyethylene glycol di(meth)acrylates such as tetraethylene glycol di(meth)acrylate and nonaethylene glycol di(meth)acrylate; polypropylene glycol di(meth)acrylates such as dipropylene glycol di(meth)acrylate and nonapropylene glycol di(meth)acrylate; (meth)acrylates of trimethylolpropane derivatives such as trimethylolpropane tri(meth)acrylate; and poly(meth)acrylates of pentaerythritol derivatives such as pentaerythritol tri(meth)acrylate monoacetate, pentaerythritol tetra(meth)acrylate, 1 dipentaerythritol hexa(meth)acrylate and dipentaerythritol tetra(meth)acrylate diacetate.

Among these, especially preferred are 1,9nonanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, nonapropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate and dipentaerythritol penta(meth)acrylate monoacetate.

Third monomer The third monomer used in this invention is a radical-polymerizable monomer capable of giving a homopolymer having a refractive index of at least 1.55, preferably at least 1.57. Monomers capable of giving i +ro~ 10 homopolymers of such a high refractive index are known per se, or even when they are not known, they may be selected easily by synthesizing homopolymers from them and measuring the refractive indices of the homopolymers. Such monomers include radical-polymerizable monomers having at least one aromatic ring, preferably 1 or 2 aromatic rings. Specifically, they include the following compounds.

Compounds represented by the formula

R

6

R

7

X

CH2=C-COOCH2CH (VII) wherein R 6 represents a hydrogen, chlorine or bromine atom or a methyl group, R 7 represents a hydrogen atom or a methyl group, X represents a chlorine, bromine or iodine atom, p is 0, 1, 2, or 3, and q is 0 or an integer of 1 to Specific examples include phenyl (meth)acrylates such as p-bromophenyl (meth)acrylate, tribromophenyl (meth)acrylate and 2,4-dichlorophenyl methacrylate; phenoxyethyl (meth)acrylates such as p-bromophenoxyethyl (meth)acrylate and tribromophenoxyethyl (meth)acrylate; 2-phenoxypropyl (meth)acrylates such as 2-(tribromophenoxy)propyl (meth)acrylate; and polyethylene glycol monophenyl ether mono- (meth)acrylates such as diethylene glycol mono(tribromophenyl)ether mono(meth)acrylate and triethylene glycol mono(tribromophenyl)ether mono(meth)acrylate.

(ii) bis-Phenol A derivatives represented by the following formula

R

8

CH

3

R

9 CH2= -o 2CH2 r CH 2

CH

2 1;-OC-CH 2 Gil

(VIII)

9 wheerein R8and R 9, independently from each other, represent a hydrogen, chlorine or bromine atom or a methyl group, Z 1, Z2 Z3 and Z 4, independently from each other, represent a hydrogen, chlorine, bromine or iodine atom, and r and s, independently from each other, represent 0, 1, 2 4 I or 3.

Specific examples include 2,2-bis(4-methacryloxyethoxy- 3,5-dibromophenyl)propane, 2,2-bis(4-methacryloxy-3,5dichlorophenyl)propane.

(iii) Styrene compounds such as styrene, chlorostyrene, dichlorostyrene, bromostyrene, methylstyrene, methoxystyrene and divinyjlbenzene.

(iv) Acrylic or methacrylic esters such as benzyl acrylate, p-chlorobenzyl acrylate, o-chlorobenzyl acrylate, dichlorobenzyl acrylate, trichlorobenzy! acrylate, bromobenzyl acrylate, dibromopentyl acrylate, tribromobenzyl acrylate, benzyl methacrylate, p-chlorobenzyl methacrylate, o-chlorobenzyl methacryalte, o-chlorobenzyl methacrylate, dichlorobenzyl methacrylate, trichlorobenzyl methacrylate, bromobenzyl methacrylate, dibromobenzyl methacrylate and tribromobenzyl methacrylate.

Allyl compounds such as allyl cinnamate, 12 diallyl phthalate and diallyl isophthalate.

These third monomers may be used singly or as a mixture of two or more. Of the third monomers, the compounds of formulae (VII) and (VIII) are preferred in this invention. Especially preferred are tribromophenyl methacrylate, tribromophenoxyethyl acrylate, 2,2-bis(4-methbenzyl methacrylate, p-chlorobenzyl methacrylate and p-bromobenzyl methacrylate.

S 10 Fourth monomer o I The copolymer of this invention may optionally a 4* oe' contain recurring units (to be referred to as fourth recurring units) derived from a radical-copolymerizable monomer (fourth monomer) which is different from the first o' 15 to third monomers. There is no particular restriction on C a the fourth monomer so long as it does not adversely affect the properties of the copolymer formed from the first to third monomers, and various radical-polymerizable monomers S may be used. Preferred fourth monomers are those which 20 further improve the properties of the copolymer. For example, when long-chain (particularly, C 6 to C 23 alkyl (meth)acrylates such as dodecyl methacrylate and stearyl acrylate, and polyalkylene glycol mono(meth)acrylates represented by the formula I 12 CH2=C-CCOCHCHO-R (IX) 2 2^ii 13 10 wherein R represents a hydrogen atom or a methyl group, R11 represents a hydrogen atom or a 32 methyl group, R 1 2 represents a hydrogen atom or a lower alkyl group, and t is 1 to such as polyethylene glycol mono(meth)acrylate and polypropylene glycol mono(meth)acrylate are used as the fourth monomer, the impact strength of the resulting copolymer can be improved. Furthermore, since the polyalkylene glycol mono(meth)acrylate also improves the hydrophilicity of the C oi 10 resulting copolymer, the copolymer has good adhesion to a glass mold in casting of lenses, for example, and lenses having a good surface condition can be obtained.

Preparation of the copolymer The copolymer of this invention can be prepared by radical-copolymerizing the first to third monomers described above and optionally the fourth monomer.

The copolymerization can be carried out in accordance with radical polymerization methods known per se, usually by a bulk polymerization method in the absence of a polymerization solvent. The casting polymerization method is especially suitable. For example, a mixture comprising the monomers and a polymerization initiator is put into a suitable mold which may be supported by gaskets or spacers and heated or irradiated with actinic rays such as light or radioactive rays to polymerize the monomers. As required, it is possible to copolymerize the monomers preliminarily to form a prepolymer or a polymer syrup before the mixture I 14 is put into the mold, and put the prepolymer or polymer syrup into the mold and complete the polymerization.

A molded article composed of the polymer of this invention may be produced in one step by using the reactive injection molding method (RIM method).

The proportions of the first to fourth monomers used in the copolymerization may be within the following tabulated ranges.

00 a ft I 0 00 O 0F 0 C 000 O 00 0 00 0i 00 0 0 00 #00 0 0 00 4. 0 0r 4 0- 0r

O

Ranges of the proportions by weight) Monomer General Preferred Most preferred lst monomer 1 90 2 70 2 2nd monomer 1 80 5 70 15 3rd monomer 5 90 10 80 30 4th monomer 0 40 0 30 0 The weight percents are based on the total weight of the monomers.

The polymerization initiators may be any of radical polymerization initiators known per se. Examples are organic peroxides such as benzoyl peroxide, diisopropyl 20 peroxydicarbonate and lauroyl peroxide and azo compounds such as azobisisobutyronitrile. The polymerization initiator may be used in an amount of generally 0.03 to 8% by weight, preferably 0.1 to 5% by weight, based on the total weight of the monomers although its amount may vary depending upon the types and reactivities of the monomers used, for example.

When the copolymerization is carried out by _1 15 heating, the heating temperature is advantageously 20 to 120 0 C generally, and 30 to 100 0 C preferably.

The above copolymerization process gives a copolymer having a high refractive index and comprising 1 to 90% by weight, preferably 2 to 70% by weight, more preferably 2 to 50% by weight, of the first recurring units derived from at least one first monomer, 1 to 80% by weight, preferably 5 to 70% by 0o0o weight, more preferably 15 to 60% by weight, of the second "o S: 10 recurring units derived from at least one second monomer, 8 and 8,8 5 to 90% by weight, preferably 10 to 80% by weight, more preferably 30 to 80% by weight, of the third recurring units derived from at least one third monomer, 0 15 and 8 optionally, up to 40% by weight, preferably up to 30% by weight, more preferably up to 20% by weight, of the fourth recurring units derived from at least one 0 fourth monomer.

I heat stabilizer, an antioxidant, etc. may be incorporated in the copolymer depending upon its end uses. Generally, these additives are added to the monomeric mixture before polymerization. They may be permeated from the surface of the copolymer by the same method as the tinting method after the polymerization.

The incorporation of the ultraviolet absorber can 16 improve the weatherability and light resistance of the resulting copolymer. Examples of the ultraviolet absorbers are benzotriazoles, benzophenones, salicylic acid compounds, cyanoacrylate compounds, and compounds known as ultraviolet stabilizers such as hindered amines, nickel complex salts and benzoates. The ultraviolet absorber may be used in an amount of 0.03 to 3% by weight, preferably 0.1 to 2 by weight, based on the total weight of the I monomers used.

S I 10 The copolymer obtained by the above polymeriza- 1 tion may, as required, be subjected to an after-treatment i 0 such as annealing.

It has been found that when at least one of the compounds represented by formulae (III), and (VI) is used as the second monomer, a copolymer having fairly satisfactory properties can be produced even if the use of the first monomer is omitted.

Thus, according to another aspect of this invention, there is provided a copolymer comprising 20 1 to 80% by weight of recurring units derived from at least one second monomer selected from the compounds of formulae (III), and and 5 to 90% by weight of recurring units derived from at least one third monomer, and optionally, up to 40% by weight of recurring units derived from at least one fourth monomer.

17 Utility The copolymer provided by this invention has excellent optical properties shown by its higher Abbe number, for example at least 35, higher refractive index, for example, at least 1.55, and less chromatic aberration than high refractive resins proposed heretofore. Furthermore, it has excellent transferability of a mold moldability), in cast molding, low shrinkage, and excellent 0 impact strength, dyeability, and processability (for exe 10 ample, polishability).

Accordingly, the copolymer of this invention may be used as optical lens materials in eyeglasses and cameras, and as optical elements in optical communication.

For production of optical lenses, the copolymer 15 of this invention may be subjected to cast polymerization whereby a lens can be directly obtained. Alternatively, S0. the copolymer of this vnetion may first be molded into a plate or block from which a lens may be cut out, followed by surface poslishing and other treatments as required.

S 20 The following Examples illustrate the present invention more specifically.

The properties of the copolymers obtained in the examples were tested by the following methods.

Refractive index and Abbe number Measured by an Abbe refractometer.

Impact strength 7A concave lens having a central thickness of 2 mm *icrf:-: 'i

L,

18 was subjected to a steel ball falling test in accordance with FDA standards, and the result was evaluated on the following standards.

Excellent: not broken Good: slightly cracked Poor: broken Surface condition The surface condition of a lens sample molded from the copolymer by cast polymerization was observed visually, and the result was evaluated on the following standards.

Excellent: a complete mirror surface Good: partly raised or depressed Poor: entirely raised and depressed 15 Tintability S" The sample polymer was tinted with a disperse dye (Sumikaron Blue, a product of Sumitomo Chemical Co., Ltd.) at 90°C for 10 minutes. The result was evaluated on the a following standard.

Good: the tintability was CR-39 or higher Fair: the tintability was slightly lower than CR-39 Poor: the tintability was much lower than CR-39 EXAMPLE 1 A mixture consisting of 22 parts by weight of dicyclopentenyloxyethyl acrylate [compound of formula (I) in which R is H, n is 1, and R 2 is 12 parts by in which i i ii 19 weight of polyethylene glycol dimethacrylate [compound of formula (IV) in which R is methyl, R is ethylene, and m is 14], 8 parts by weight of polypropylene glycol monomethacrylate [compound of formula (IX) in which RI is methyl,

R

I I is methyl, R 12 is hydrogen and t is 5 23 partss of tribromophenyl methacrylate, 35 parts by weight of 2,2-bis(4-methacryloxyethoxy-3,5-dibromophenyl)propane, 3 parts by weight of tertiary butyl peroxy-2-ethyl hexanoate as a radical polymerization initiator and 1.0% by weight of 2-(2'-hydroxy-3',5'-ditert-butylphenyl)-5-chlorobenzotriazole as an ultraviolet absorber was cast into a glass mold, and polymerized with hot air. Specifically, the mixture was maintained at 50 C for 7 hours, and 60 C for hours. The temperature was then -ai4sdto 90 C over 4 hours, and the mixture was maintained at 90°C for 4 hours. The resulting copolymer article was taken out from the glass mold, and post-cured at 110 C for 2 hours. The resulting molded article had a refractive index of 1.566 and an Abbe number of 38.7. As shown in Table 1, it had excellent impact strength, surface condition,'tintability, polishability and light resistance suitable for use as a ?4 material for lenses.

EXAMPLES 2-14 In each run, a molded article of a copolymer was produced in the same way as in Example 1 except that the monomers in the proportions shown in Table 1 were used instead of the monomers used in Example 1. The results are AA shown in Table 1.

Table 1 Ex- Ccxmposition by weight) Refractive Abbe IImpact Surface Tintample index number jstrength condition ability 1 DCPE.A/PPMA/PEDM1(14) /Br 3 PhMA/Br BPMA 1.566 38.7 jExcellent Excellent Goo 2 1.569 37.5 (24/8/9/23/36) 3 1.567 37.9 (25/8/5/18/44) 4 1.587 35.3 (18/8/12/31/33) 1.561 40.8 I (29/8/13/14/36) 6 DCPEA/PPMA/PEDM (14) /Br 3 Ph4A/Br BP4A 154 3.

(18/9/15/23//35) 154 3.

7 Nopol MA/PRWAPEEX(14)/Br 3 PhMA/]Br BPMA 1.562 40.0 I (18/15/23/35) to be continued iil r L

C*-C

r I

-C

ci 0 o 000 0 4t~li 4 0) 0 C 0 0 a* 0C Table 1 (continued) Ex- Cwposition by weight) Refractive Abbe Impact Surface Tintample index nuner strength condition ability 8 IBMAP2A/PE4M(14)/Br PhMA/Br BPMA 1.561 40.5 Excellent Excellent Good 118/9/15 23/35) 9 DCPEA/PPf4APEE*(14)/Br PhOEtMA/Br BPMA 1.565 38.6 (118/11/2034) DCPEA/PPMA/PEDM(14)/BzMA/Br BPMA 1.556 44.5 (26/9/14/11/40) 11 DCPEA/PPMA/PEDM(14)/Br PhMA/BPMA 1.566 38.5 (37/10/15/28/20) 12 DCPE/PPMA/PW(14)/St/BPMA 45.1 Fair Fair (34/12/19/9/26) 1-3 DCPE/PPMA/PEM(1l4)/DAIP 1.551 48,C Excellent Good (33/12/18/37) 14 DCPEA/PED(14)/Br 3 PhMA/Br 1.568 37.4 Fair (2417/17/42) 8 88 10 22 The abbreviations used in Table 1 for the monomers are as follows:-, DCPEA: dicyclopentenyloxyethyl acrylate PPMA: polypropylene glycol monomethacrylate (5 6 moles of propylene glycol added) PEDM polyethylene glycol dimethacrylate (14 moles of ethylene glycol added) Br 3 PhMA: tribromophenyl methacrylate Br 4BPMA: 2,2-bis(4--methacryloxyethoxy-3,5-dibromophenyl) propane DCPMA: dicyclopentanyl methacrylate Nopol MA: Nopol methacrylate IBMA: isobornyl methacrylate Br 3 PhOEtA: tribromophenoxyethyl acrylate BzMA: benzyl methacrylate BPMA: bisphenol A dimethacrylate DAIP: diallyl isophthalate 8 8.1 8 8 I 884 8 4 14 44 I 4 8; 44 4 0 4 I 8 88 23 EXAMPLE A mixture consistging of 26 parts by weight of dicyclopentenyloxyethyl acrylate (DCPEA), 20 parts by weight of tetraethylene glycol dimethacrylate, 54 parts by weight of tribromophenyl methacrylate (Br 3 PhMA), 2 parts by weight of tert-butylperoxy(2-ethylhexanoate) as a radical polymerization initiator and 0.5 part by weight of hydroxy-3',5'-ditertiary-butylphenyl)-5-chlorobenzotriazole as an ultraviolet absorber was cast into a mrld constructed of a glass mold and gaskets of ethylene/vinyl acetate copolymer, and heate' from 35 C to 80°C over the course of hours. The resulting copolymer article was taken out from the glass mold, and post-cured at 100 0 C. The resulting molded article had a refractive index of 1.571 and an Abbe number of 41.4. As shown in Table 2, the molded article showed excellent impact strength, polishability, and light resistance and was suitable for optical applica- Stions.

EXAMPLES 16-41 In each run, a copolymer article was obtained in the same way as in Example 15 except that the monomers in the proportions shown in Table 2 were used instead of the monomers used in Example 15. The results are shown in Table 2.

Table 2 Ex- Composition by weight) Refractive Abbe Impact ample jindex number strength DCPEA/Br 3 PhMA/PEDM (26/54/20) 1.571 41.4 Excellent 16 n (28/49/23) 1.563 42.8 17 jDCPEA/Br 3 PhMA/PEDM(4)/PEDM(9) (14/50/17/19) 1.558 43.3 18 (17/55/20/8) 1.565 41.4 19 DCPMA/Br 3 PhMA/DEGDM/PEDM(9) (17/51/3/29) 1.554 43.5 DCPEA/Br 3 PhOEtA/HDA/PEDM(9) (18/54/15/13) 1.568 42.3 21 DCPEA/Br 3 PhMA/TMPTM/PEDMf9) (20/54/13/12) 1.570 41.8 22 DCPEA/Br 3 PhMA/DPPA/PEDM(9) (18/54/8/20) 1.567 42.5 23 DCPMA/Br 3 PhMA/DPHA/PEDM(9) (17/53/6/24) 1.564 42.6 24 DCPMA/DrSt/PEDM(4) (20/60/20) 1.571 40.4 DCPEA/Br 3 PhMA/NDA/PEDM(9) (10/56/23/11) 1.561 41.2 26 DCPEA/Br 3 PhMA/NDMA/PEDM(9) (7/56/22/15) 1.560 42.1 27 DCPEA/Br 3 PhMA/NDA (35/50/15) 1.568 28 1IBEMA/Br 3 PhMA/NDA/Ph DM(9) (8/58/19/15) 1.561 39.5 to be continued Table 2 (continued) Ex- Composition by weight) Refractive Abbe Impact ample index number strength 29 DCPA/Br 3 PhOEtA/NDA/PEDM(9) (7/56/22/15) 1.558 42.6 Exeln DCPEA/Br 3 PhMA/NDA/DoMA (15/56/23/6) 1.561 40.1 I 31 DCPEA/Br 3 PhMA/DoDA (10/56/34) 1.562 40.7 I 32 DCPMA/BrBzMA/NDA (10/70/20) 1.560 41.8 33 IDCPEA/BrSt/NDA/PEDM(9) (10/60/20/10) 1.569 38.5 34 DCpEA/Br 3 PhMA/DoDA/Br 4 BPMA (10/30/30/20) 1.573 37.7 DCPEA/BzMA/Br 3 PhMA/'NDA/PEDM(4) /PEDM(9) 1.5604 43.0 3 (3/7/50/15/10/15) 36 Br 3 PhMA/NDA/DoMA (60/20/20) 1.5625 38.8 Fair 37 Br 3 PhMA/NDA/PEDM(9) (58/20/12) 1.5630 40.2 Excellent 38 Br 2 St/TMPTM/PEDM(9) (60/15/25) 1.5612 39.3 39 jBr 3 PhMA/TMPTM/StMA (58/12/30) 1.5605 41.1 BrBzMA/DPHA/PEDM(9) (70/.15/15) 1.5568 41.9 41 BzMA/Br 3 PhMA/DPHA/StMA (20/45/15/20) 1.5645 38.3 26 The abbreviations used in Table 2 to indicate the monomers were as follows:- (the abbreviations in Table 1 are also applicable to Table 2) PEDM polyethylene glycol dimethacrylate (4 moles of ethylene glycol added) PEDM polyethylene glycol dimethacrylate (9 moles of ethylene glycol added) DEGDM: diethylene glycol dimethacrylate HDA: 1,6-hexanediol diacrylate TMPTM: trimethylolpropane trimethacrylate DPPA: dipentaerythritol pentaacrylate monoacetate DPHA: dipentaerythritol hexaacrylate NDA: 1,9-nonanediol diacrylate NDMA: 1,9-nonanediol dimethacrylate IBEMA: isobornyloxyethyl methacrylate DoMA: dodecyl methacrylate DoDA: 1,12-dodecanediol diacrylate BrBzMA: bromobenzyl metahcrylate BrSt: bromostyrene Br St: dibromostyrene 2 StMA: stearyl methacrylate BzMA: benzyl methacrylate

Claims

1. A copolymer having a high refractive index and comprising 1 to 90% by weight of first recurring units derived from at least one monomer represented by the for- mula R 1 CH2=C-COO CH2CH20 0-R2 (I) wherein R 1 represents a hydrogen, chlorine or bromine atom or a methyl group, R 2 represents a polycyclic aliphatic hydrocarbon group, and n represents 0, 1, 2 or 3, 1 to 80% by weight of second recurring units derived from at least one monomer containing at least two 3 R residues CH2=C- which is an ester of an aliphatic poly- hydric alcohol with an unsaturated carboxylic acid of the R 3 R formula CH 2 =C-COOH in which R represents a hydrogen, chlorine or bromine atom or a methyl group, and 5 to 90% of third recurring units derived from at least one radical-polymerizable monomer capable of giving a homopolymer having a refractive index of at least 1.55.

2. 1e-opolymer-e 'claim 1 wherein the polycyclic aliphatic hydrocarbon groups represented by R 2 in formula 28 MI has 7 to 30 carbon atoms, and is particularly 1 4a 2 wherein Y1and Y2each represent a hydrogen, chlorine or bromine atom or a lover alkyl group, or together form an additional bond. 2520 A O-S AcL&Ae,5 orC Cko-~

3. +hecopolymer -Fhe intesc d monomer is a compound selected from the group consisting of compounds of the following formulae (III) to (VI) I4 CH =C-COO-R -OOC-C=C1HII CH =C-COO*R 5 OiiFOC-C=CH 2 (IV) CH -0-A 3 CHC CH -0-A 5 MH 0A a dCH 2 0- 3H O A 3 wherein R 3represents a hydrogen, chlorine or bromine atom or a methyl group, R 4represents an alkylene group having 2 29 to 18 carbon atoms, R 5 represents an alkylene group having 2 to 10 carbon atoms, at least two of A A and A repre- R 3 sent the residue CH2=C-CO- and the remainder represents an alkanoyl group, at least two of A4 to A9represent the alkanoyl group, at least two of A to A represent the to Do o t 4 1 residue CH2=C-CO- and the remainder represent an alkanoyl group, and m is an integer of 2 to A o-s cAdc iv\ o~ne oe o? c~os, zo

4. he-copolymer/ f olaim 1 wherein the third monomer is selected from the group consisting of compounds of the following formula (VII) R R 7x CH 2 =C-COO*CH 2 CHOP (VII) I 4 o i wherein R 6 represents a hydrogen, chlorine or bromine atom or a methyl group, R 7 represents a hydrogen atom or a methyl group, X represents a chlorine, bromine or iodine atom, p is 0, 1, 2 or 3, and q is 0 or an integer of 1 to and bisphenol A derivatives of the following formula (VIII) CH 2 2 CH 2 0OC-CCH 2 (VIII) wherein R 8 and R 9 independently from each other represent a hydrogen, chlorine or bromine atom or C i 30 1 2 3 4 a methyl group, and Z Z 2 Z and Z independently from each other, represent a hydrogen, chlorine, bromine or iodine atom, and r and s, independently from each other, represent 0, 1, 2 or 3. A copolymer as claimed in any one of claims 1 to 4 wherein the second monomer is selected from the group consisting of 1,9-nonanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, tetraethylene gylcol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate and dipentaerythritol penta(meth)acrylate monoacetate.

6. A copolymer as claimed in any one of claims 1 to wherein the third monomer is selected from the group consisting of tribromophenyl methacrylate, tribromophenoxyethyl acrylate, 2,2-bis(4-methacryloxyethoxy- benzyl methacrylate, p-chlorobenzyl methacrylate and p-bromobenzyl methacrylate.

7. A copolymer as claimed in any one of claims 1 to 6 j «comprising 1 to 70% by weight of the first recurring units fi 5 to 70% by weight of the second recurring units (B) I t and 10 to 80% by weight of the third recurring units

8. A ropolymer as claimed in claims 1 to 7 which further comprises up to 40% by weight of recurring units derived from at least one fourth radical polymerizable monomer selected from long-chain alkyl(meth)acrylates and polyalkylene glycol mono(meth)acrylates.

9. A copolymer as claimed in claim 8 wherein the fourth ._iil ~l-L 1- I_ 31 monomer is selected from the group consisting of C6-C23 alkyl (meth)acrylates and polyalkylene glycol mono(meth)- acrylates of Lhe formula R 1 0 SR CH2=C-COOCH2 CHH--Rt 1 2 (IX) R 1 1 wherein R 10 represents a hydrogen atom or a methyl group, R II represetns a hydrogen atom or a methyl group, R12 represents a hydrogen atom or a lower alkyl group, and t is 1 to A process for producing a copolymer having a high refractive index, which comprises radical-copolymerizing 1 to 90% by weight of at least one first monomer of the formula 1 R, R 2 CH 2 =C-COOCH 2 CH 2 0-R (I) 2 wherein R 1 represents a hydrogen, chlorine or bromine atom or a methyl group, R represents a polycylic aliphatic hydrocarbon group, and n is 0, 1, 2 or 3, 1 to 80% by weight of at least one second monomer containing at least two residues of the formula R3 CH2=C- r -i j 1 II) 1- _li 4 I 32 wherein R 3 represents a hydrogen, chlorine or bromine atom or a methyl group, which is an ester of an aliphatic polypolyhydric alcohol with an unsaturated carboxylic acid of formula R 3 CH =C-COOH wherein R 3 is as defined, and 5 to 90% by weight of at least one third radical-polymerizable monomer capable of giving a homopolymer having a refractive index of at least 1.55, and optionally up to 40% by weight of at least one radical-polymerizable fourth monomer which is different from the first to third monomers.

11. A process as claimed in claim 10 wherein the copolymerization is carried out by cast polymerization.

12. An optical lens composed of a copolymer as claimed in I any one of claims 1 to 9.

13. A copolymer as claimed in claim 1, substantially as hereinbefore described with reference to any one of the examples. S 14. A process as claimed in claim 10, substantially as hereinbefore described with reference to any one of the examples. DATED: 8 FEBRUARY 1990 PHILLIPS ORMONDE FITZPATRICK Attorneys for: ODAJIMA CO CO7p 4A*