PHOTOCHROMIC COMPOSITION RESISTANT TO FATIGUE

COMPOSITION PHOTOCHROMIQUE RESISTANT A LA FATIGUE

English Abstract

PHOTOCHROMIC COMPOSITION RESISTANT TO PATIGUE
ABSTRACT OF THE DISCLOSURE
An organic photochromic composition comprising spiro
[indoline-2,3'-[3H]-naphth [2,1-b] [1,4] oxazine] dye
(spirooxazine dye) and unconventional ultraviolet stabilizers.
The ultraviolet stabilizers improve the light fatigue
resistance of the spirooxazine (S.O.) dye and will not hinder
the photocolorability of the photochromic composition. The
unconventional ultraviolet stabilizers belong to the class of
hindered amine light stabilizers (HALS) and excited state
quenchers.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of increasing the light fatigue resistance of a spirooxazine
photochromic composition which comprises incorporating in
said composition a hindered amine light stabilizer.
2. A method according to claim 1 wherein said photochromic
composition additionally contains a singlet oxygen quencher
ultraviolet stabilizer.
3. A method according to claim 2 wherein said singlet oxygen
quencher ultraviolet stabilizer is a Ni2+ ion complex with an
organic ligand.
4. A method according to claim 2 wherein said singlet oxygen
quencher ultraviolet stabilizer is selected from [2,2' -thiobis
[4 -(1,1,3,3-tetramethylbutyl) phenolato] (butylamine)] nickel,
nickel [0-ethyl (3,5-di-tert-butyl-4-hydroxybenzyl)] phosphonate,
nickel dibutyldithiocarbamate, nickel di-isopropyl dithiophosphate,
bis [2,2' -thiobis-4-(1,1,3,3-tetramethylbutyl) phenolato] nickel,
cobalt (III) tris-di-n-butyldithiocarbamate, and cobalt (II) diisopropyldithio-
carbamate.
5. A method according to claim 4 wherein said photochromic
composition comprises a polymer containing about 0.1% to about
15% by weight spirooxazine photochromic dye.
6. A method aecording to claim 5 wherein said hindered amine
light stabilizer and said singlet oxygen quencher ultraviolet
stabilizer are incorporated in said photochromic composition
in a total amount of about 0.01% to about 5% by weight.
7. A method according to claim 6 wherein said hindered amine
light stabilizer is a tetramethyl piperidine derivative.
- 21 -

8. A method according to claim 1, wherein
said hindered amine light stabilizer is selected from one or more
compounds of the following formutae:
<IMG>
wherein R1, R2, R4, R5, R6, R7, R9, and R10 are lower alkyl,
R3 and R8 are selected from lower alkyl and hydrogen, and
n is 1-12;
<IMG>
wherein R1, R2, R4, R5, R6, R7, R9, R10, R11, R12, R13, R14,
R15, R16 and R17 are lower alkyl, and R3 nnd R8 are selected
from lower alkyl and hydrogen;
- 22 -

Claim 8 con't 2
<IMG>
wherein R1, R4, R5, R11 and R16 are selected from lower alkyl
and hydrogen, R2, R3,?R7,R8, R9, R10, R12, R13, R14, R15, R17
and R18 are lower alkyl; n1 is 1-12, and n2 is 1-15;
<IMG>
wherein R1, R2, R4, R5, R6, R7, R9, and R10 are lower alkyl,
R3 and R8 are selected from lower alkyl and hydrogen, n1 is
1-12 nnd n2 is 1-15;
<IMG>
wherein R1, R2, R3, and R4, are lower alkyl, and n is 1-15;
and (C26 H52 N4)n wherein n is 1-15.
-23 -

9. A method according to claim 8 wherein said photochromic
composition contains one or more of a spironxazine photochromic
dye of the formula
<IMG>
wherein one of R1, R2 and R3 is selected from the group consisting
of hydrogen, halogen, lower alkoxy, and lower alkyl and the
others are hydrogen; R4 and R5 are selected from the group
consisting of hydrogen, lower alkyl, lower alkoxy, halogen, and
trifluoromethyl; and R6 is lower alkyl.
10. A method according to claim 9 wherein said hindered amine
light stabilizer is selected from one or more of
bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate;
bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate;
di(1,2,2,6,6-pentamethyl-4-piperidinyl) - butyl(3',5' -ditertbutyl-
4-hydroxybenzyl) malonate; poly[(6-[(1,1,3,3-tetramethylbutyl) -
amino]-1,3,5-triazine-2,4-diyl) (1,6-[2,2,6,6-tetramethyl-4-piperidinyl]
amino-hexamethylene)]; poly[[6-(morpholino)-s-triazine-2,4-
diyl] [1,6-(2,2,6,6-tetramethyl-4-piperidyl) amino] -hexamethylene];
and dimethyl succinate polymer with 4-hydroxy-2,2,6,6-tetramethyl-
1-piperidineethanol.
-24-

11. A photochromic composition comprising at least one photochromic
compound having the structural formula
<IMG>
wherein one of R1, R2 and R3 is selected from the group consisting
of hydrogen, halogen, lower alkoxy, and lower alkyl and the
others are hydrogen; R4 and R5 are selected from the group
consisting of hydrogen, lower alkyl, lower alkoxy, halogen, and
trifluoromethyl; and R6 is lower alkyl; and
a hindered amine light stabilizer.
12. A composition according to claim 11 additionally comprising
a singlet oxygen quencher ultraviolet stabilizer.
13. A composition according to claim 12 wherein said singlet oxygen
quencher ultraviolet stabilizer is a Ni2+ ion complex with an
organic ligand.
14. A composition according to claim 12 wherein said singlet oxygen
quencher ultraviolet stabilizer is selected from [2,2'-thiobis
[4 -(1,1,3,3-tetramethylbutyl) phenolato] (butylamine)] nickel,
nickel [0-ethyl(3,5-di-tert-butyl-1-hydloxybenzyl)] phosphonate,
nickel dibutyldithiocarbamate, nickel di-isopropyl dithiophosphate,
bis[2,2 -thiobis-4-(1,1,3,3-tetramethylbutyl) phenolato] nickel,
cobalt (III) tris-di-n-butyldithiocarbamate, and cobalt (II) diisopropyldithio-
carbamate.
- 25 -

15. A composition according to claim 11, wherein
said hindered amine light stabilizer is selected from one or more
compounds of the following formulae:
<IMG>
wherein R1, R2, R4, R5, R6, R7, R9, and R10 are lower alkyl,
R3 and R8 are selected from lower alkyl and hydrogen, and
n is 1-12;
<IMG>
wherein R1, R2, R4, R5, R6, R7, R9, R10, R11, R12, R13, R14,
R15, R16 and R17 are lower alkyl, and R3 and R8 are selected
from lower alkyl and hydrogen;
-26-

Claim 15 con't 2
<IMG>
wherein R1, R4, R5, R11 and R16 are selected from lower alkyl
and hydrogen, R2, R3 , <IMG>, R9, R10, R12, R13, R14, R15, R17
and R18 are lower alkyl; n1 is 1-12, and n2 is 1-15;
<IMG>
wherein R1, R2, R4, R5, R6, R7, R9, and R10 are lower alkyl
R3 and R8 are selected from lower alkyl and hydrogen, n1 is
1-12 and n2 is 1-15;
<IMG>
wherein R1, R2, R3, and R4 are lower alkyl, and n is 1-15;
and (C26 H52 N4)n wherein n is 1-15.
-27-

16. A composition according to claim 15 wherein said hindered amine
light stabilizer is selected from one or more of
bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate;
bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate;
di(1,2,2,6,6-pentamethyl-4-piperidinyl) - butyl(3',5'-ditertbutyl-
4-hydroxybenzyl) malonate; poly[(6-[(1,1,3,3-tetramethylbutyl)-
amino]-1,3,5-triazine-2,4-diyl) (1,6-[2,2,6,6-tetramethyl-4-piperidinyl]
amino-hexamethylene)]; poly[[6-(morpholino)-s-triazine-2,4-
diyl] [1,6-(2,2,6,6-tetramethyl-4-piperidyl)amino]-hexamethylene];
and dimethyl succinate polymer with 4-hydroxy-2,2,6,6-tetramethyl-
1-piperidineethanol.
17. A composition according to claim 15 additionally comprising
a plastic host.
18. A composition according to claim 17 containing about 0.1% to
about 15% by weight of said photochromic compound and about
0.01% to about 5% by weight of said stabilizer or stabilizers.
-28-

Description

D~CKGI~oU~D OF rllr, INvrNTIoN
The invel-tion relates to a photochromic composition,
and more particularly to an organic photochromic composition
comprisinq spiro [indo]ine-2,3'-[31l~-naphth [2,1-b] [1,4] oxa~ine]
(S.O.) dye and unconventional ultraviolet (UV) stabili~ers.
Compoullds which under-Jo reversible photo-induced
color changes nre termed photochromic compounds. When
subjected to ultraviolet light or visible irradiation, these
pho~ochromic compounds change their transmission. They
subsequently revert to their original color state when they
are subjected to a difEerent wavelen~Jtl) oE radiation or when
the initial light source is removed.
~ lthou~h the or~nnic photocl)romic n~ater;als hnve
been known for over 50 yenrs, they have not had widespread
industrial or commercial use. ~rhis is primarily due to the
irreversible decomposition phenomenon, generally known as

~` ¢ ~L~6~
light Eatigue. Repeated expo.sure to light cnuses the
photochromic material.s to lo.se l:heir pllol:ocllromism.
It is thoucJl~t l:hat ligl~t or heal: or both light and
heAt are responsible Eor the photo(lecomposition oE organic
photochromic compouncls. Tl~us, many people have tried to
increase the ligl)t Eatigue resistance oE the compounds by
adding numerous conventional antioxklant~s or ultraviolet light
absorbers. For exalnple, U.S. Patent No. 3,212,898 teaches the
use oE conventional UV ab.sorbers such as benzophenone and
benzotriazole to increase the photochromic li Ee oE
photochromic benzosp;ropyran compounds. Similarly, U.S. Patent
No. 3,666,352 teaches the use oE conventional UV 1ight
absorbers in photochromic mercury thiocal-hazollate l.enses,
transparent to radiation oE wavelengths greater than 4200
Angstrom units and opaque to radiation oE wavelengths less
than 4200 Angstro~n units, in order to substantially increase
the durability oE the lenses against photochemica1
degradation .
one class oE organic photochromic compounds, spiro
[indoline-2,3'-[3~l]-naphth 12,1-b] [1,4] oxazine] dyes (S.O. dyes)
are known to have good light Eatigue resistance. In general,
the light Eatigue resistance oE the spirooxazine compounds is
about 100 times better than the c].osely related spiropyrans.
This class oE photochromic compounds has been disclosed in
I~.S. Patent Nos. 3,562,172; 3,578,602; 4,215,010; 4,342,66~;
and 4,440,672.
-3-

3V3'~
The precise mechanism Eor photodecomposition of S.O.
dyes is not yet fully understoocl. ~Ithough some
eircumstantlal evidence indieates that oxyc~en is involved in
the photodecomposition proces.q, the traditiollal antioxid~nts
(aryl amines and hindered phenols~ do not improve the licJht
Eatigue resistance oE S.O. dyes. The eonventional UV
stabilizers, substituted benæophenones and benzotriazoles,
cause a small improvement in the l;ght Eatigue resistanee of
S.O. dyes, but they cannot be used eEEectively since they
create a sereening efEeet by absorbing UV radiation strongly
in the region where the S.O. dyes absorb W radiation. By
eompeting with the S.O. dyes to absorb W light, these
conventional stabilizers substantially decrease the eEEeetive
light intensity for S.O. dye aetivation. Furthermore, some oE
the eonventional ~V stabilizers are detrimental to S.O. dyes
under eertain eonditions.
In addition, the presenee of acids has a deleterious
ëffeet on 5Ø eompounds. ~cids may be in the plastie host
material from whicll the phol:ochromie artiele is made, such a.s
PVC or cellulosics. The aeids are usually generated either
thermally during the Eorrning proeess, or photoehemieally
during u5e of the photoellrornic artiele. The S.O. dye solution
b.eeomes a pinkish to reddish eolor in the presenee of even a
minute alnount oE aeid, and the solution eeases to show a
photoehromie eEfeet. The pinkish to reddish eolor is likely
due to the formation of a complex between the S.O. compound
and acid. A base must be usecl to neutralize the aeid and to
restore the original colorless or light blue eolor.

3'~
U.S. Patent No. ~ 1(), 672 cl;scl.oses the use oE
organonickel complex stahilizers to improvt! the ~ ht fai:i~Ut!
resistance oE the photoch1 olnic compoul-c1s. Ilowever, these
organonickel comploxes do not have the abill ity to neutralize
acids which may be presenl: !
SUMM~I~Y Ol~ T111~ INVENTION
The problems oE the prior art are overcome by the
discovery that a group of unconventional UV stabilizers will
irnprove the light-Eatigue resistance oE S.O. dyes, while not
affecting their photocolornbility. Tl-er;e unconventional UV
stabilizers belong to the class Oe hindere(1 amine litJht
stabilizers (I~ ,S) and excited state quencl1ers. Ilindered amine
light stabilizers of Eer an advanta~e over organometallic
complex stabilizers in their ability to neutralize acid, and
to thus improve the light-fatigue resistance and preserve the
original color oE the S.O. dyes. It is preierable to use the
hindered amine light stabilizers together with excited state
quenchers in the organic photochromic compound of the
invention; this combination has a synergetic effect in
improving the light Eatigue resistance of the S.O. compounds.
These UV stabilizers will not hindt!r the
photocolorability of S.O. dyes, since they have a minimal
absorption in the UV region where S.O. dyes absorb. The S.O.
dye and UV stabil izers may be incorporatl?d within optically
clear plastics to n~,a1ce a photochromic element suitable for a
--5--

3~
photochromic sunglass len,s, ski ~oggle, or other plastics to
render them photochromi c
Accordingly, it is an ob ject oE the present
invention to improve the light Eatigue resistance Oe an
organic photochromic composition containing S.O. dye.
It is another object oE the present invention to
improve the light Eatigue resistance oE these pllotocllromic
compositions without hinderillg their phol:ocolorability.
It is a Eurtller object oE the present invention to
use such improved photochromic compositions to Eabricate
photocllromlc artlcles such a9 sunglasses, ophthalmic lenses,
ski goggles, window coating3, toys, fabrics, and the like.
Other objects and Eurtller scope oE applicability oE
the present invention wil l become apparent Erom the det~iled
description to follow.
i

f
DEscn~ IoN O~ T1113 PRrA~`~11RED l:MBODIMENT
~ he o~--3anic p11otoc11ro111ic composition of the present
invention comprise~: a~ spiro rindoline-2,3'-~3111-nnphth
12,l-_] [],~1 oxaz;ne1 (]ye ~spirooxazi11e 3ye), having t1~e
structural Eormulfl
C1t3
n~ ~ V= \~n2
'I
wherein one of Rl, R2 and n3 is hydrogen, halogen, lower
,alkyl, or lower alkoxy and the others are hydrogen; R4 and R5
1'are hydrogen, lower alkyl, lower alkoxy, halogen, or
triEluoromethyl; and R6 is lower alkyl; and, b) an
unconventional UV stabilizer or stabilizers. As used
throughout the specification and claims, "lower" means up to
12 carbon atoms (n=1-12~ in the Eree alkyl or alkoxy radical
group, wherein the alkyl Eree radical group has the structural
formula of CnH2n+l, and the alkoxy Eree radical group has the
structural Eormula of Cn1-12n+l0. PreEerallly~ the W stabilizer
comprises a hindered amine light stabilizer ~11ALS~. The
. .
preEerred hindered amine light stabilizers cornprise
derivatives oE tetramethyl piperidine. Most preEerably, the UV
stabilizer comprises a combination oE a hindered amine light
~stabilizer and an excited state quenc1)er. PreEerably~ the
excited state quencher comprises an organonickel complex light
!
'
I

c~
stabilizer. For a description o~ hindered ~mine light
stabilizers and e~cltecl sta~e quenchers sec the ~ollowing
four articles in Mode,-n Plastics ~nryclopedia:
1) Shute, ~aymond
"Antioxidants," pp. 102-103 (19~3-1989); 2) Li, S.S.,
"Ultraviolet Stabilizers," pp. 174-177 tl983-1984); 3) Patel,
A., "Antioxidants," pp. 106-107 (19~-19~5); and ~)
Stretanski J.~ ltraviolet Stabilizers " pp 179-180
~19~4-1985).
Between 0.1 anA about 15% by weight oE the S.O. dye
and between 0.01 and about 5% by wei~ht oE the IWJS stabilizer
or combined W .stal)ili7ers, depenclinc~ on their soLubility can
be incorporated into a plastic article havinc~ enhanced light
~atigue resistance. rL~he SO clye and ~V stahilizers may be mixecl
in a sGlution with an opticalLy clear polymer which is
thereaEter cast as a Film, sheet, lens, or toy or a polymer
WhiCIl iS injection molr3ed or otl~erwise sl~aped into a ~ilm or
lens; or a prepolymerize(l ~ilm or lells containin(~ ti)e W
stabilizers may l~e immersed in a dye ~ath comprising S.O. dye
dissolved in a solution o~ organic solvents such as alcollol
toluene halogenal-e-l hydrocarbon or the like. otl~er methods o~
blending the W stabi:li%ers with the S.O. dye and polymers
such as coating or laminating may also be employecl.

6~)3'~
One hinclered ~mine l.i~ht stabili7.er, use~ul in th~
~rganic photochroin.i.c c~mposi.tion oE the inventiorl, comprises
the structuraL formula
~5 n~
~n7
~3 ~\oc(cll2)n1l0~7r
nl () () n~()
1' 2' ~ 5' ~6~ R7~ and Rlo are .lower alkyl; l~
and R8 are lower alkyl OL' h~-lr(.)c~en; and n=1-12; and in
particular, the hindered am.ine li~3ht stabilizer is Bis
~2,2,6,6-tetramethy.l-4-piperidillyl) sebacate, wherein Rl, R2,
R9~ R5, ~6~ R7, ~9 and Rlo are methyl, R3 and ~ are hydrogen,
and n=8, sold under the trade~ar~ oE Tinuvin 770, and obtained
from the C.iba-Geig~ Corporation; and also in particular, the
hindered amine light stabilizer is Bis .(l,2,2,6,6-pentamethyl-
4~piperidinyl) sebacate, wherein Rl, R2, R9, R5, R6, R7, Rg
and Rld are methyl, R3 and R~ are methyl, and n=~, sold under
the trademark of Tinuvin 765, and obtained from the Ciba-Geigy
Corporation.

Another hinclered amine lic~ht stabilizer which is
useful in the organic photocllrolnic composition oE the
invention comprises tl~e structur~l Eormula
n5 nh
11 r~
R3 N ~ I ~ N 1
2 ~ ~ ~ C - C 0 ~ 1
nl o I ~ nlo
Cll,~
~7\J~c/ 12
16 1115 ol~ n/~ r~l3
wherein Rl, R2, R~, R5, R6, l~7~ Rg~ Rlo~ R12' R13' R14'
R15, R16, and ~17 are lower ~lkyl; and R3 ~nd Ra are lower
alkyl or hydroc~en; ana in particll].ar, the hindered amine light
stabilizer is di~l,2,2,6,G-pentamethyl-4-piperidinyl)-
butyl(3',5'-ditertbutyl-~-hydroxybenzyl) malon~te, wherein R1,
R R , R5~ R6, R7~ l~9~ Rlo~ R12~ Rl~, Rl~' 15 16 17
are methyl, Rll is butyL, and ~ and R8 are methyl, sold under
the trademark of Tinuvin 14~, an~1 obtained Eroln the Ciba-Geigy
Corporation.
1 0--

3q3~
~ nother 11inderecl alliine light sl:al~ilizer which is
useEul in the orgallic pllotochrolnlc compo.~ition o~ the
inverl~ion compl.ise~ 1:l)(? .c;trLIotlllal Eorlllu].n
N - (Cll2)n - _N
nl3 ~ n9 ~ n~
Rl, R4, R5, Rll, and R16 are lower alkyl or llydrogen;
R2, R3, R6, R7, R~ 9, l~lo, R12' R13' R14' 15 17 18
are lower alkyl; nl=1-12; and n2-1-15; and in particular, the
hindered amine light stabi].izer is poly[(6-[~1,1,3,3-tetra-
methylbutyl)amino]-1,3,5-triazine-2,4-diyl)(1,6-12,2,6,6-tetra-
methyl-4-piperi-linyl]amino-hexamethylene)], wherein R2, R3, R6,
7' 8' Rg~ R~ R12~ 3~ Rl~ Rls, R17, and Rl~ are meth~
Rl, R4, R5, Rll, and ~16 are hydrogen, and nl=6, sold under
the tradern~rk Chimassorb 9~4, and obtained ~rom the Ciba-Geigy
Corporation.
--1 .1.--

~L~6~03'~
Another hinlerec~ am;.ne light stabilizer which is
useful in the organic pholocllrolllic compos.ition of the
invention comprises the strllcturl~l. Eormul.a
; ~ n ~ 2
Rl~ R2~ R5~ R6, 1~7~ ~91 and Rlo are lower alkyl;
R3 and R8 are 1ower alkyl or l~ydrogen; n~ 12; an(l n2=1-15;
and in partic~llar, the llinclered ami.lle li.gllt sta~il.i%er is
poly[~6-tmorpholino)-s-tr.iazine-2,~-diyl][l,6-(2,2,6,6-tetra-
methyl-4-piperidyl)amino]llexclmetllylene], wherein Rl~ ~2~ R4,
R5, R6, R7, 1~9, and Rlo are methyl, 1~3 and ~ are hydroc~en,
ancl nl=6, sold uncler tlle tr~demark Cyasorh 33~fi, alld ohtained
from the American Cyanalmicd Cor.poration.
-12-

~ nother hill~ler.ed ~mine light stabili~er which is
use~l in the or~anic phot~cllrolnic compo~;t;on ~E the
invention compri.ses ~llc 5~ lo~ur~l. Eo~m
nl
... ~ 2 - .
., _ o ~ 11 cll~ C112 u ~ 2 C~2 C _
wherein Rl, R2, R3, an(l 1~ are lower alkyl; and n-1-15; and in
particular, the hindered amine ].igllt stabil.izer is a dimethyl
sllccinate polymer with ~-hydroxy-2,2,6,6-tetrarnethyl-1-piper-
idineethanol, where;n l~l R2, 1~3 and ~4 are metllyl., sold under
the trademark Tinuvin 622 ancl obta.ined Erom the Ciba-Geigy
Corporation.
Other hindered amine liq11t stabilizers which are
use~ul in the orgarlic photochromic compo.si tion of the
invention include a hindered alnine light stabilizer having the
structural formula (C26H52N~)n, wherein n=1-15 sold under the
trademark Of Spinuvex A-36 and obtained Eroln the Borg-Warner
Corporation; and a hindered amine li~ht stabili2er sold under
the trademark of Mostavin TMN20, and obtained Erom tile
American Hoechst Corporation.
Ultraviolet stabil.i%ers, belonqinq to the class oE
excited state quenchers, which are useful in the organic
photocllromic compound oE the invention, include colnplexes of
i~ Ni ion with some orqanic ligand cobalt (III) tris-di-n-
-13-

butyldithiocarbamate, cobalt (II) diisopropylditi~iocarbamate
(Co DIPDTP), and nickel diisopropyldithiophosi?l)~te (Ni
DIpD~rp)~
The preEerred excited state quellcl)ers are singlet
oxygen c~uenchers, and in partic-llar, complexes oF Ni2 ion
~ith some organic ligancl. rhese i~ii2~ complexes are normal~y
used in polyole~ins l:o provitle protection irom photo-
degradation Most preEerably, the Ni2i c~olnplexe~ are:
[2,2 -Thiobis ['~i-(1,1,3,3-tetralnt-~thyLbut:yl) phenolato]
~butylamine)~ nickel, havinci the structuraL ormuLa
CH~ 1 - C''2
c,l3~ C~3
S . . . . . . ~.i . . . NH2 ( CH2 ) 3CH3
CH3 C--C~2 ~--~ -C/
CH3 Cil3
sold under the trademarkoE Cyasorb UV 10~, and obtained from
the American Cyanalnid Company;
. .
- - .

Ni cke 1 [ 0 -e thy l ( 3, 5-d i - te r t-bu ty l - Il-hyd ro~:ybe n zy L ) ]
pho~;phonate, havin~l th~ r~lcl:ural. Eormu].a
_
(C113) 3C
. l~o~ 2 IP Mi
(C~3~ 3~ C~t~5 o
sold under the trademark of Irgastab 2002, and obtained Erom
the Ciba-Geigy Corporat:ion; Nickel dibutyldithiocarbamate,
having the structural Eormula
._
CH3 ~ CH2 ) 3 ~ S
/NC\ Ni
CH3 ( C}l2 ) 3/ \S
_ __ 2
sold under the trademark oE nylex NBC, and ol>ta.ined Erom E.l.
duPont de Memours ~ Company;
-15-

Bis [2,2'-thiobis-4-(1,1,3,3-tetramethy1buty1~ pheno1ato]
nickel, having the structural formu1a
C~13_ClU3C~t2~ Ho~?}Cl3cll2-cl-c~3
~13~ C113 \ C,l3 c,~3
s ~ s
CH5~ 2 1 ~DII O_~ C--Cll--Ci_C~l
t ~l3 Cil3 C~13
sold under the trademark o~ UV-Chek ~M 101, and obtained from
the Ferro Corporal:ion; Nickel di-lsopropyl clitl~iopllosphate (Ni
DIPDTP~, having the structural ~ormula
l(CH3)2CI~0]2 p~ ~ Ni'~ ~ [Cll(cll3)2]2
and other Ni2 coml?lexes so]d under the trademark~ of W -chek
AM 105, UV-Chek ~M 12fi, and ~V-Chelc ~M 205 which can also be
obtained from the Ferro Corporat:ion.
The pre~errecl S.O. dyes ~or use in accc)rd~nce with
the invention are 1,3,3,~,5-pentamethy1-~'-methoxy-spiro
[indo1ine-2,3'-[3ll]-naphtll [2~1-b] ~1,4] oxa~ine;
1,3,3,5,6-pentamethy1-9'-met)loxy-spirooxazine;
1,3,3-trimethy1-5'-methoxy spirooxa~ine;
1,3,3-trimethy1-5-methoxy spirooxazine;
1,3,3t4,5-pentamethyl-8'-bromo spirooxazine;
1,3,3,5,6-pentamethy1-8'-bromo spirooxazine;
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1,2,3,3,4,5-hexAInetllyl-9'-metlloxy spirooxazine;
i,2,3,3,5,6-hexame l:hyl -9 ' -me ~:hoxy spiroox;l7.ine;
l~3~3-trimethyl-~-triEluorome~hy~ -mel:hoxy g~irooxa7.ine;
1,3,3-trimetllyl-6-lriEluorom~-3tllyl-9'-metlloxy spirooxazine;
'1,3,3-trimethyl~4-tr;Eluorolnethyl-5'-mel:lloxy .spirooxazine; and
1,3, 3-trimethyl-6-triEl~lorolllethyl-5'-metl~oxy spirooxa~ine.
The preferred plastic hosts are cellulose acetate
butyrate (CAB); CR-39'~, a diethylene glycol bis
(allyl carbonate) obtained from PPG Industries, Inc.; Lexan'~,
a polycarbonate resin conclensation product oE bisphenol-A and
phosgene, obtained Erom General Electric; Plexi(Jla3l~ a
polymethyl methacrylate obtained Erom the Rohlll and lla~s
Company; polyvinyl c!lloride; and polyolefins.
'rl-e invention is Eurther illustrated by the
EolLowing non-limiting example~s.
!j - Rxamples 1-B
Eight cellulose acetate butarate (CAB) samples
~having a thickness oE 17-19 m1s., containing 0.4% by weight oE
a mixture of 1,2,3,3,4,5- and 1,2,3,3,5,6-hexamethyl-9'-
methoxy SØ isomers, with and witl-ollt hindered amine light
stabilizers (H~T..S) were prepared by castin<J a methylene
.chloride solution of C~B. Four successive castings were needed
to obtain the desire(l thickness with good optical appearance.
The control sample containe-1 no ll~I.S. ~rhe seven other samples
contained variou.s hindered amine ligllt stal~ilizers in an
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1~6~03'~
arhi.trary amount o~ 1% by wei-3hl~ e sn~ le.s were suhjected
to a 20-llour cycle lia(leollleter exl-osu~e tesl:ing. ~r~er Civ~
cycl.e.s, the control. .3alllL)l.e wil:hollt ll7~T,'`, .lo~sl: al.l. its
photochromisln whi.l.e t:hl? salllr].es with Tl7~r.~S still. sllowed good
photocllromi~m. ~ lt-~ specil~ic II~I.S usecl and l:he percerltage ot
residual photocoloral~i:Lity o~ the CA13 salnL~les aftc!r 100 hours
of Fadeometer exposure is sllown in Table 1.
Tab.l.e 1
Percentacle oE l~esidual Photocolorabi].;.l:y
Example ~I~LSPercent Residual Phc ocolorability
Control None * 0
2 Tinuvin 770 6~1
3 Tinuvin 765*84
4 Tinuvin 622 31
Tinuvin 14'tG7
6 Chimassorb 9~14* 76
7 Spinuvex ~36* 90
8 Hostavin N2U71
Examples 9-10
Two CAB sheet samples (60 mls.) were nnade by
- injection molding. One o~ the C~B sheet samples had 0.2~ by
weight Oe a mixture oE 1,2,3,3,~t,5- and 1,2,3,3,5,6-hexa-
methyl-9'-methoxy s~;.rooxazine .isomers and 0.2~ hy weight o~
UV-Chek AM-205 as an excited state quencher. q~he other sample
. . also had 0.2~ by weigllt Tinuvin 622 as a hindered amine ligllt
stabilizer in addition to the S.O. dye and the W~Chek ~M-205*
The sample witllout the ll~LS lost all oE its photochrolnism
after 15 20-hour Fa(leometer exposure cycles. ~lowever, the
sample with the 117~L', still. had ~10~i o~ thc original
photocolora~ilit:y ].eEt.
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~L2~
_xampl.es 11-13
7~ colltroL salllple Wrl~; cast at .l.G()" in r~n oven Eor 20
minu~:es Eroln a pl.asti.~ol. SOl.UI:ion COllSi.C.~:i.llfl 0E 3~
d.iisodecylphtllalate~ 3r~ octyl epoxy t:allate 3% mark
stal~ilizer 63% PVC and 0. l-rh 1~ 3~ 3 1~ 5- and 1 31 3 5 6-penta-
methyl-9 -methoxy S.O. ~.tye mixture Two more samples were
prepared as follows: One sample had in addition to the
ingredients in the control sample 0 2~ by weight: UV-Chek
AM-205 and the other sample llad 0.2r~ by weight w-chek AM-205
and 1.0r~ by weight Tinuvin 622. rrhe control sample lost all oE
its photochromic eE~ect aEter 20 hours o~ Fadeomet:er exposure;
the sample with UV-CIlek r~M-205 lasted ~0 hours be~ore losinq
its photochromic e~Eect and the sample witll both UV-Chek
AM-205 and Tinuvin 622 lastecl 1~0 hours beEore losing its
photochromic eE~ect.
Examples 14-18
An ethanol solution oE 1 3 3-trimel:llyl S.O. dye was
prepared by dissolving 13.1 mg oE dye in 100.0 ml oE ethanol.
Two milliters of the .sol.ution was placed in each of Eive 10.0
ml volumetric Elasks. lllen 0.1)1 ml oE 1 N IICl w IS added to
each Elask and eacll solut:.ion was ~lilute(-l with etl~nnol to 10.Q
ml. Each so].ution wa.s originaJ.ly col.orle.ss b~ becarne pinki.sh
and lost its pl-otochl-oln.ic eEEect once the IICl wrls addcd. To
Eour oE the solutions wa.r, added about 3 mg oE eit:her Tinuvin
770 Tinuvin 765 Cyasorb 10~3~1 or uV-Chek ~M-205. The
solutions containing l:he li.nuvin and Cyasorl~ compounds
reverted to color].ess solut:iol)s ancl regained their
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~ 26~
photochromic eEEecl, while the other solutions remained
pinkish and showed no photocllrolnic efeect.
Although the inventi.on has be~n described with
reference to its pre~erre.l embodimellt, otller eml>odimellts call
achieve the same resul~s. Variations and moclieications o~ thc
present invention wil.l he obvious to thc):ie skil.Led in the art
and it is intended to cover in tlle apuellcled claims all such
modifications ~nd eq~livalents.
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Representative Drawing