CA1226996A - Fire-retardant photopolymers - Google Patents
Fire-retardant photopolymersInfo
- Publication number
- CA1226996A CA1226996A CA000423459A CA423459A CA1226996A CA 1226996 A CA1226996 A CA 1226996A CA 000423459 A CA000423459 A CA 000423459A CA 423459 A CA423459 A CA 423459A CA 1226996 A CA1226996 A CA 1226996A
- Authority
- CA
- Canada
- Prior art keywords
- polythiol
- retardant
- chain
- composition
- tetrahalophthalate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D181/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing sulfur, with or without nitrogen, oxygen, or carbon only; Coating compositions based on polysulfones; Coating compositions based on derivatives of such polymers
- C09D181/02—Polythioethers; Polythioether-ethers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G75/00—Macromolecular compounds obtained by reactions forming a linkage containing sulfur with or without nitrogen, oxygen, or carbon in the main chain of the macromolecule
- C08G75/02—Polythioethers
- C08G75/04—Polythioethers from mercapto compounds or metallic derivatives thereof
- C08G75/045—Polythioethers from mercapto compounds or metallic derivatives thereof from mercapto compounds and unsaturated compounds
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/22—Secondary treatment of printed circuits
- H05K3/28—Applying non-metallic protective coatings
- H05K3/285—Permanent coating compositions
- H05K3/287—Photosensitive compositions
Abstract
FIRE-RETARDANT PHOTOPOLYMERS
Abstract of the Invention A novel flame retardant photosensitive composition is disclosed comprising an allylic or methallylic, halogenated phthalate and a polythiol.
Abstract of the Invention A novel flame retardant photosensitive composition is disclosed comprising an allylic or methallylic, halogenated phthalate and a polythiol.
Description
I
BACKGROUND OF THE INVENTION
Allylic esters of phthalic acids and androids have been prepared by a variety of standard esterifica~ion procedures. For example, the reaction of allylic halides with metal salts of phthalic acids has been described, in both aqueous and an hydrous systems, usually in the presence of a tertiary amine catalyst. This esterification is a two-step reaction, requiring first the preparation of the metal salt of phthalic acid and second the reaction of the metal phthalate with the allylic halide. The requirement in this process for initial preparation of the phthalate salt from the phthalic acid, before the actual esterification, is accompanied by several disadvantages; in an hydrous systems the process of preparing the an hydrous metal phthalate is ime-consuming since the salt must be prepared in aqueous solution and subsequently dried and requires special equipment due to corrosion problems; if the metal phthalate is prepared and used in aqueous medium, substantial decomposition of the allylic halide in the subsequent esterification may occur due to its instability in the presence of water, and there is the economic disadvantage of requiring an additional operation in the overall synthesis In U. S. Patent 3,086,g85, to overcome the above mentioned disadvantages, a new method of preparing allylic halides is taught which provides for the direct reaction, in one step' of a phthalate acid or android with an allylic halide using an amine catalyst.
U. S. Patent 3,Q35,084 teaches synthesis of methallyl phthalateJ from salts of phthalic acid using as well an amine catalyst.
French Patent 1,372,~67 introduces a novel catalyst, namely a copper halide, metallic copper mixture to effect the synthesis of ally phthalate by the same reaction .
route of the above discussed patents, namely conversion ox the phthalic acid or android to its salt via alkaline neutralization and subsequent reaction with an ally halide.
Ally esters of phthalic acids have found a variety of uses as plasticizers, as chemical intermediates and as taught, for example, in U. S. Patents 3,824,104, 3,376,139 and 3,891,695 as components of photosensitive compositions.
Furthermore, the halogenated allylic esters of phthalic acids have found a variety of applications such as in insecticide compositions, as light-stabilizers for polyvinyl halide resins, and, additionally, these compounds are useful in the preparation of polymers which, due to the high halogen content, are flame-retardant in nature. As an example of art documenting particularly the last application, one may refer to U. S. Patent 4,105,~10 which teaches the imparting of flame-retardant properties to curable vinyl unsaturated polymers by incorporation therein of Delilah tetrabromophthalate. These halogenated ally esters of phthalic acid may be made by a variety of methods, e. g., by the reaction of a halogenated phthalic android and an alcohol as described in U. S. Patent
BACKGROUND OF THE INVENTION
Allylic esters of phthalic acids and androids have been prepared by a variety of standard esterifica~ion procedures. For example, the reaction of allylic halides with metal salts of phthalic acids has been described, in both aqueous and an hydrous systems, usually in the presence of a tertiary amine catalyst. This esterification is a two-step reaction, requiring first the preparation of the metal salt of phthalic acid and second the reaction of the metal phthalate with the allylic halide. The requirement in this process for initial preparation of the phthalate salt from the phthalic acid, before the actual esterification, is accompanied by several disadvantages; in an hydrous systems the process of preparing the an hydrous metal phthalate is ime-consuming since the salt must be prepared in aqueous solution and subsequently dried and requires special equipment due to corrosion problems; if the metal phthalate is prepared and used in aqueous medium, substantial decomposition of the allylic halide in the subsequent esterification may occur due to its instability in the presence of water, and there is the economic disadvantage of requiring an additional operation in the overall synthesis In U. S. Patent 3,086,g85, to overcome the above mentioned disadvantages, a new method of preparing allylic halides is taught which provides for the direct reaction, in one step' of a phthalate acid or android with an allylic halide using an amine catalyst.
U. S. Patent 3,Q35,084 teaches synthesis of methallyl phthalateJ from salts of phthalic acid using as well an amine catalyst.
French Patent 1,372,~67 introduces a novel catalyst, namely a copper halide, metallic copper mixture to effect the synthesis of ally phthalate by the same reaction .
route of the above discussed patents, namely conversion ox the phthalic acid or android to its salt via alkaline neutralization and subsequent reaction with an ally halide.
Ally esters of phthalic acids have found a variety of uses as plasticizers, as chemical intermediates and as taught, for example, in U. S. Patents 3,824,104, 3,376,139 and 3,891,695 as components of photosensitive compositions.
Furthermore, the halogenated allylic esters of phthalic acids have found a variety of applications such as in insecticide compositions, as light-stabilizers for polyvinyl halide resins, and, additionally, these compounds are useful in the preparation of polymers which, due to the high halogen content, are flame-retardant in nature. As an example of art documenting particularly the last application, one may refer to U. S. Patent 4,105,~10 which teaches the imparting of flame-retardant properties to curable vinyl unsaturated polymers by incorporation therein of Delilah tetrabromophthalate. These halogenated ally esters of phthalic acid may be made by a variety of methods, e. g., by the reaction of a halogenated phthalic android and an alcohol as described in U. S. Patent
2,462,601 by the reaction of the alkali metal salt of a tetrahalophthalic acid and an alkyd alcohol as illustrated in Us S. Patent 2,617,820, etc.
In response to the need for developing compositions suited for the application as coating for electronic circuitry, which incorporate two basic properties, namely (a) that they be radiation curable and (b) what they be fire-retardant, research programs have been devised which, inter alias have focused on the aforediscussed halogenated ally phthalic esters since these compounds meet these two basic requirements 2~9~3~
These and other requirements have been met by the flame-retardant photosensitive composition of the present invention which is hereafter described.
SUMMARY OF THE Intention The present invention embraces a novel photosensitive composition which combines excellent W curability and very good flame-retardant properties.
Disclosed herein are halogenated ally or methallyl esters, i. e., pylons, which, in combination with polythiols and optionally photo initiators and other additives, result in screenable liquids which can be applied to electronic circuit boards and cured with W light to hard fire-retardant coatings.
The invention provides a flame-retardant, photo curable composition comprising a liquid, chain-extended, thither-containing allylic or methallylic tetrahalophthalate or a mixture thereof, and a polythiol.
The invention further provides a process of forming a liquid chain-extended thioether-containing allylic or methallylic tetrahaloph~halate which comprises reacting a solid member of the tetrahalophthalate group of the formula where X I (1) X~B~ Rl-R2~
25~ CC~2~C~2 I X~B~ R2 I
X COC~2C3~2 (3) X-Br; I 2~C~
X R2 (4) XsCl~ R1~2~
(5) X~C17 2~3 and 6 ) XDC~ Lo 3 I Eye with a polythiol in an amount so as to provide I to 0.~5 equivalents SH/equivalent of car~on-to-carbon double bond in the tetrahalvphthalate at a temperature in the range 60 to 150C.
ENTAILED DESCRIPTION CF~It~r INvrN~
It is an object of the present invention to drop a W curable composition suitable for coatings for electronic circuitry.
It is a further object of the present invention Jo develop W curable electronic circuit coatings which are characterized by an acceptable degree of flame retardant These and other objects will become obvious as the description of the invention proceeds.
According to the present invention tetrahalophthalic androids are converted to salts in base and reacted with ally chloride anger ~e~hallyl chloride in the presence of copper/cuprous chloride catalyst Jo give allyl/m2thallyl tetrahalophthalate esters in high yield and purity.
- pa-Z~;~96 Compounds covered by the present disclosure have the following structure:
where X O R (1) X=Br; Rl=R2=H
X n I I X=Br; Rl=R2=C~3 X CCH2C SHEA (3) Or ; R2=CH3 X R2 I X=Cl; Rl=R2=~
(5) X=C1, Rl=R2=C~3 and (6) X=Cl; lo R2=CH3 While compound 1 is a known compound (taught in U. S. Patent 4,105,710), compounds 2 through 6 are not documented in the prior art. U. S. Patent 3,035,084, while teaching preparation of the methallylic phthalate, as in the case of compound 5, does not teach the preparation of a halogenated methallylic phthalate, and, furthermore, synthesis of any of these halogenated compounds 1 through 6 by use of copper/cuprous chloride catalyst and by the reaction method described is also not disclosed in the prior art even though use of the catalyst and the reaction method are known for synthesis of non-halogenated phthalates as evidenced by the patents ; referred to under background of the Invention'.
These pylons, which are crystalline solids, are prereacted with a substoichiometric amount of polythiol in I the presence of a free radical thermal initiator, e. g., benzopinacol to give a liquid mixture. This mixture is then formulated with additional polythiol and optionally a photo initiator and other additives to make screenable - liquids which can be applied to electronic circuit boards . and cured with W light to hard fire-retardant coating.
The use of benzopinacol to prereact a pylon with a substoichiometric amount of a pothole is disclosed in Us S. Patent 4,020,233.
_ 5 _ I
Polythiols operable herein are simple or complex organic compounds having a multiplicity of pendant or terminally positioned ASH functional groups per average molecule.
The polythiol must contain 2 or more ASH groups/
molecule and have a viscosity range of essentially 0 to 20 million centipoises (cups) at 70C as measured by a Brook field Viscometer either alone or when in the presence of an inert solvent, aqueous dispersion or plasticizer.
Operable polythiols in the instant invention usually have molecular weights in the range of about 34 to about 20,000 and preferably, from about 100 to about 10,000.
The polythiols operable in the instant invention may - be exemplified by the general formula R8-(SH)n where n is at least 2 and R8 is a polyvalent organic moiety free from reactive carbon-to-carbon unsaturation. Thus, R8 may contain cyclic groupings and hotter atoms such as N, P or O and primarily contains carbon-carbon, carbon-hydrogen, carbon-oxygen or ~ilicon-oxygen containing chain linkages free of any reactive carbon-to-carbon unsaturation.
One class of polythiols operable herein are esters of i thiol-containing acids of the formula ~S~Rg~COOH where Rug is an organic moiety containing no reactive carbon-to-carbon unsaturation with polyhydroxy compounds of structure Rlo-(OH)n where Rio moiety containing no reactive carbon-to-carbon j unsaturation, and n is 2 or greater, These components will react under suitable conditions to give a polythiol having tune general structure:
R It --R
I/
Al where Rug and Rio are organic moieties cuntainin~ no I
reactive carbon-to-carbon unsaturation, and n is 2 or greater.
Polythiols such as the aliphatic monomeric polythiols methane ditniol, hexamethylene deathly, decamethylene deathly, tolylene-2,4-dithiol and the like) are operable herein. Examples of the polythiol compounds preferred include, but are not limiter to, esters of thioglycilic acid (HS-CH2COOH), alpha-mercaptopropionic acid (HS-CH(CH3)-COOH and beta-mercaptopropionic acid (HS-CH2CH2COO~) with polyhydroxy compounds such as glycols, trios, tutorials, ponytails, hexaols and the like. Specific examples of the preferred polythiols include, but are not limited to, ethylene glycol bis(thioglycolate), ethylene glycol bus (beta-mercapto-preappoint), trimethylolpropane iris (thioglycolate), trimethylolpropane tris-(beta-mercaptopropionate), pentaerythritol tetrakis (thioglycolate) and pentaerythritol tetrakis (beta-mercaptopropionate), all of which are commercially available. A specific example of a preferred polymeric polythiol is polypropylene ether glycol bis(beta-mercaptopropionate~ which is prepared from polypropylene-ether glycol ye. 9., Pluracol P2010, ! Wyandotte Chemical Corp.) and beta-mercaptopropionic acid by esterification.
Polythiol terminated polyoxyalkylene polyols, such as i trimethylolpropane tris-(3-mercapto-2-hydroxypropyl-monooxypropyl~ ether and trimethylolpropane iris-(3-mercapto-2-hydroxypropyl-dioxypropyl) ether, are also operable. Furthermore, saturated alicyclic deathless, such as 1,5-cyclooctanedithiol, 3,7,11-trimethyl-1,5-cyclododecanedithiol, 4-hexyl-1,2-cyclohexanedithiol, ethylcyclohexyl deathly and d-limonene deathly represent commercially available deathless that are operable herein.
I
Additionally, polythiols operable herein to give cured solid polythioether products with the pylon in the presence of a photo initiator include the mercaptoester derivatives of styrene-allyl alcohol copolymers set owlet in U. S. Patent 3,904,499 and the isocyanurate containing polythiols disclosed in U. S. Patent 3,~76,440 and liquid thiol-terminated polymers made in accord with Us S.
Patent 3,258,495.
An example of the aforesaid latter type liquid they'll-terminated polymer is CAPTURE 3-800, commercially available from Diamond Shamrock Chemical Company.
In carrying out the reaction to transform the crystalline solid pylons to a chain-extended, polythio-ether containing liquid by reaction with a polythiol in the presence of a free radical thermal initiator, the amount of polythiol used is a substoichiometric amount.
sufficient polythiol must be used to convert the solid crystalline pylon to liquid polythioether but care must be exercised that no too much polythiol is added which could increase viscosity too much or cause golfing. It has been found that a range of 0~1 to 0.25 equivalents SH/equivalent of double bond in the pylon is operable to satisfy the aforesaid requirements. Following the chain extending reaction, additional polythiol is added to the I - system to supply the stoichiometric amount necessary to react with the remaining carbQn-to-Carbon double bonds in the chain-extended pylon optionally along with a photo initiator for use as a photo curable composition.
The chain-extending reaction is performed at temperatures above the melting point of the pylon and the disassociation temperature of the free radical thermal initiator. Temperatures in the range 60 to 150C are usually employed.
* Trademark , The free radical, thermal initiators used herein are selected from substituted or unsubs~ituted pinnacles, ago compounds, thrums, organic peroxides and mixtures thereof.
S The organic peroxides operable are of the general formula:
( 1 on wherein n = 0 or 1, R is independently selected from hydrogen aureole, alkyd, aureole carbonyl, alkaryl carbonyl, aralkyl carbonyl and alkyd carbonyl and Al is alkyd or aureole, said alkyd groups containing 1 to 20 carbon atoms.
Examples of operable organic peroxides include t but are not limited tol2,5-dimethyl-2,5-di(t-butylperoxy)-hexane, 1,3-bis(t-butylperoxyisopropyl)benzene, Boyce-(cumylperoxyisopropyl)benzene, 2,4-dichloroben20yl peroxide, caprylyl peroxide, laurel peroxide, t-butyl peroxyisobutyrate, bouncily peroxide, p-chlorobenzoyl peroxide, hydroxyheptyl peroxide, di-t-butyl doper-phthalate, t-butyl pleracetate, t-butyl perbenzoate, dicumyl peroxide t l,l-di(t-butylperoxy~-3,3,5 Tramiel-cyclohexane and di-t-butyl peroxide.
Examples of ago compounds operable herein include, but are not limited to, commercially available compounds such as 2-t-butylazo-2-cyanopropanè; 2,?'-azobis~2~4-dimethyl-4-methoxy-valeronitrile); 2,2'-azobis(isobutyronitrile);
2,2'-azobis(2,4-dimethylvaleronitrile) and l,l'-azobis-(cyclohexanecarbonitrile~.
The thrums operable as thermal initiators herein are of the formula:
I C-S-S C-N
wherein Al, R3, R3 and R4 taken singly can be hydrogen, linear or branched alkyd having from 1 to about 12 carbon atoms, linear or branched alkenyl having from 2 to about 12 carbon atoms, cycloalkyl having from 3 to about 10 ring carbon atoms, cycloalkenyl having from 3 to about 10 ring carbon atoms, aureole having from 6 to about 12 ring carbon atoms, alkaryl having from 6 to about 12 ring carbon atoms, aralkyl having from 6 to about 12 ring carbon atoms and, when taken together, Al and R2 and R3 and R4 can each be a diva lent alkaline group (-CnH2n-) having from 2 to about 12 carbon atoms, a diva lent alkenylene group (-CnH2n 2-) group . having from 3 to about 10 carbon atoms, a diva lent alkadienylene group -(CnH2n-4)- having from 5 to about 10 carbon atoms, a diva lent alkatrienylene group -(C Ho 6)- having from 6 to about 19 carbon atoms, a diva lent alkyleneoxyalkylene group (-CxH2xOLCxH2x-) having a total of from 4 to about 12 carbon atoms or a diva lent alkyleneaminoalkylene group:
( - CXH 2XNCX~ 2x having a total of from 4 to about 12 carbon atoms.
Operable thrums include, but are not limited to, tetramethylthiuram disulfide, tetraethylthiuram disulfide, di-N-pentamethylenethiuram disulfide, tetrabutylthiuram disulfide, dipehnyldimethylthiuram disulfide, diphenyl-diethylthiuram disulfide and diethyleneoxythiuram disulfide and the like.
I
The substituted or unsubstituted pinnacles operable herein as a thermal initiator have the general formula:
RlP'3 X Y
wherein Al and R3 are the same or different substituted or unsubstituted aromatic radicals, R2 and R4 are substituted or unsubstituted aliphatic or aromatic radicals and % and Y which may be the same or different are hydroxyl, alkoxy or airlocks.
Preferred pinnacles are those wherein Al, R2~ R3 and R4 are aromatic radicals, especially phenol radical and X and Y are hydroxyl.
Examples of this class of compounds include, but are not limited to, benzopinacol, 4,4'-dichlorobenzopinacol 4,4'-dibromoben~opinacol, 4/4'-diiodobenzopinacol, 4,4',4'l,4"'-tetrachlorobenzopinacol, 2,4,2l,4'-tetrachloro-benzopinacol, 4,4'-dimethylbenzopinacol, 3,3'-dimethyl-benzopinacol~ 2~2'-dimethylbenzopinacol, twitter-methylbenzopinacol, 4,4'-dimethoxybenzopinacol, 4,4.,4 n 4 n -tetramethoxybenzopinacol, 4,4'-diphenyl-benzopinacol, 4,4'-dichloro-4~,4"'-dime~hylbenzopinacol, 4,4'-dimethyl-4",4"'-diphenylbenzopinacol~ xanthonpinacol, fluorenonepinacol, acetophenonepinacol, 4,4'-dimethylaceto-phenone-pinacol, 4~4'~dichloroacetophenonepinacol, 1,1,2-triphenyl-propane-1,2-diol, 1,2,3,4-~etraphenyl-butane-2,3-diol, 1,2-diphenylcyclobutane-1,2-diol, propiophenone-pinacol r 4 4'-dimethylpropiophenone- -pinnacle, 2,2'-ethyl-3,3'-dimethoxypropiophenone-pinacol, 1,1,1,4,4,4-hexafluoro-2,3-diphenyl~butane-2,3-dioof.
i99~
As further compounds according to the present invention, there may be mentioned: benzopinacol-mono-methyl ether, benzopinacol-mono-phenylether, benzopinacol and monoisopropyl ether, benzopinacol monoisobutyl ether, benzopinacol moo (diethoxy methyl) ether and the like.
The aforementioned free radical, thermal initiators are added to the composition in amounts ranging from 0.01 - 1.0% by weight based on the weight of the pylon and polythiol.
The compositions of the present invention may, if desired, include such additives as antioxidant, accelerators, dyes, inhibitors, activators, fillers, pigments, antistatic agents, flame-retardant agents, thickeners, thixotropic agents, surface-active agents, viscosity modifies, extending oils, plasticizers, tackifiers and the like within the scope of this invention. Such additives are usually preblended with the ethylenically unsaturated compound or polythiol prior to or during the compounding step. Operable fillers include natural and synthetic resins, carbon black, glass fibers, - wood flour, clay, silica alumina, carbonates, oxides, hydroxides, silicates, glass flakes, glass beads, borate, phosphates, diatomaceous earth, talc, kaolin, barium sulfate, calcium sulfate, calcium carbonate, antimony oxide and the like. The aforesaid additives may be present in quantities up to 500 parts or more per 100 parts of ethylenically unsaturated compound and polythiol by weight and preferably about 0.005 to about 300 parts on the same basis.
The curing reaction to form hard, fire-re~ardant coatings on substrates is preferably but not necessarily, carried out in the presence of a photo initiator. Various photo initiators operable herein include, but are not limited to, benzophenone, acetophenone, o-methoxybenzo-phenone, acenapthene-quinone, methyl ethyl kitten, valerophenone, hexanophenone, alpha-phenylbutyrophenone, p-morpholinopropiophenone, dibenzosuberone, 4-morpholino-benzophenone, 4'-morpholinodeoxybenzoin, p-diacetyl-Bunsen, 4-aminobenzophenone, 4'-methoxyacetophenone, benzaldehyde, alpha-tetralone, 9-acetylphenanthrene, 2-acetylphenanthrene, 10-thioxanthenone, acutely-phenanthrene, 3-acetylindole, 9-fluorenone, Linda none 1j3,5-triacetylbenzene, thioxanthen-9-one, xanthrene-9-one, 7 H-benz[de]anthracen-7-one, l-naphthalaehyde, 4,4'-bis(dimethylamino) benzophenone, fluorene-9-one, l'-acetonaphthone, 2'-acetonaphthone, buttondown, triphenylphosphine, tri-o-tolyphosphine, acetonaphthone, buttondown, benz[a]anthracene-7.12-dione, etch Another class of photosensitizes is the Bunsen ethers, such as Bunsen methyl ether, Bunsen ethyl ether, Bunsen isopropyl ether and Bunsen isobutyl ether. The photosensitizes are usually added in an amount ranging from 0.0005 to 30~ by weight of the ethylenically unsaturated compound and the polythiol.
In addition, the halogenated ally compound in the composition of this invention can act as its own photo initiator, without added photo initiator of the above types.
When US radiation is used, an intensity of 0.0004 to 60.0 watts~cm in the 250-400 nanometer region is usually employed.
The curing reaction can alto be accomplished by using high energy ionizing radiation at a dose rate in the range 0.00001 to 1,000 megarads/second.
The amount of ionizing radiation which is employed in curing in the instant invention can vary between broad limits. Radiation dosages of less than a megarad up to 10 megarads or more for electrons are operable; preferably 0002 to 5 megarads energy absorbed are employed.
The following examples will aid to explain, but specifically not limit, the subject invention unless, otherwise noted, all parts and percentages are by weight.
Example 1 Synthesis of Delilah Tetrabromophthalate (DATBP) A mixture of 464 g tetrabromophthalic android, 80 9 sodium hydroxide, 650 ml water, 0.04 g copper powder, 2 9 cuprous chloride and 306 g ally chloride was stirred 2 hours at 70C to give 528 g (94~) Delilah te~rabromo-phthalate. The pi was kept between 6.5 and 7.5 by adding sodium hydroxide solution during the reaction.
Example 2 Dimethallyl tetrabromophthalat~ (DMATBP) was synthesized in a similar manner as set out in Example 1 by using methallyl chloride in place of ally chloride.
Example A mixture of ally methallyl tetrabromopnthalate, - 20 DATBP and DMATBP was synthesized in a similar manner as set out in Example 1 by using a mixture of methallyl chloride and ally chloride.
Delilah tetrachlorophthalate was synthesized by the same procedure in Example 1 using te~rachlorophthalic android in place of tetrabromophthal~c android.
Example 5 A mixture of 5~G g Delilah tetrabromophthalat~ 5.25 g of dimethallyl tetrabromophthalate, 10.0 g Delilah tetrachlorophthalate, 2.4 g ethylene glycol bis-(3-mercaptopropiona~e) and 0.16 g benzopinacol was heaved for 30 minute at 110C to form a chain-extended, liquid polymer. Thereafter at awoke, 9.1 g ethylene glycol byway mercaptopropionate) and 9.52 g of finely divided hydrated alumina HYDRA 710 from Alcoa) was added and mixed.
This formulation was shown to screen-print well, to photo cure fast and to exhibit good solder resistance and, S most importantly, testing of 2 ten-mil thick films have revealed it to be flame-retardant as reflected by an average Oxygen Index of 29.
In general, flame retardancy is measured by ASTM
Method D 2863-74 for oxygen index; an oxygen index of about 27-28 or higher is considered generally acceptable.
While suitable for application to electronic circuit boards, other applications for this composition may be easily envisaged where radiation curable fire-retardant coatings are required.
Variations may be made in materials, proportions and procedures without departing from the scope of this invention.
Example 6 2.09 g of Delilah tetrabromophthalate from Example l and 0.91 g of pentaerythritol tetrakis(beta-mercapto-preappoint) were mixed in a 13 mm test tube and slowly melted at 80-85C to a clear solution The solution was transferred to a glass plate and spread as a 20 mix thick film thereon. The film was exposed to W radiation from a Ferry W lamp for l minute. A solid, cured film resulted.
Example 6 was repeated except that a photo initiator, i. e., 0.03 g of 2,2-dimethoxy-2-phenylacetophenone, was added to the system. solid, cured film resulted.
example 8 Example 6 way repeated except that a photo initiator, it e., 0.03 g of dibenzosuberone, was added to the system. A solid, cured film resulted I
Example 9 Example 6 was repeated except that a photo initiator, i. e., 0.03 g of 4,4'-dimethoxybenzophenone, was added to the system. A solid, cured film resulted.
Example 10 example 6 was repeated except that a photo initiator, i. e., 0.03 9 of benzophenone, was added to the system. A
solid, cured film resulted.
Example 11 Example 6 was repeated except that Owe g of buoyancy-pinnacle was added to the original mixture and, after formation ox the thioether-containing chain-extended pylon, 0.03 9 of 2,2-dime~hoxy-2-phenylacetophenone was added prior to irradiation. A solid cured film resulted.
Example 12 A mixture of 20.48 g of Delilah tetrachlorophthalate, 2.06 g pentaerythritol tetrakis(beta-mercaptopropionate) and 0.01 g benzopinacol were heated with stirring at 125C
for 1 hour to form a chain-extended, liquid polymer. The polymer was cooled to 60C and 3.26 g of 2,2-dimethoxy-2-phenylacetophenone, 0.03 g of pyrogallol and OOZE g of phosphorous acid were added to the system along with 10.28 9 of pentaerythritol tetrakis(beta Marquette-preappoint). This admixture was spread as a 20 mix thick coat on a glass plate and exposed to US radiation for 2 1/2 minutes. A solid, cured, transparent coating adhering to the glass plate re~ultedQ
In response to the need for developing compositions suited for the application as coating for electronic circuitry, which incorporate two basic properties, namely (a) that they be radiation curable and (b) what they be fire-retardant, research programs have been devised which, inter alias have focused on the aforediscussed halogenated ally phthalic esters since these compounds meet these two basic requirements 2~9~3~
These and other requirements have been met by the flame-retardant photosensitive composition of the present invention which is hereafter described.
SUMMARY OF THE Intention The present invention embraces a novel photosensitive composition which combines excellent W curability and very good flame-retardant properties.
Disclosed herein are halogenated ally or methallyl esters, i. e., pylons, which, in combination with polythiols and optionally photo initiators and other additives, result in screenable liquids which can be applied to electronic circuit boards and cured with W light to hard fire-retardant coatings.
The invention provides a flame-retardant, photo curable composition comprising a liquid, chain-extended, thither-containing allylic or methallylic tetrahalophthalate or a mixture thereof, and a polythiol.
The invention further provides a process of forming a liquid chain-extended thioether-containing allylic or methallylic tetrahaloph~halate which comprises reacting a solid member of the tetrahalophthalate group of the formula where X I (1) X~B~ Rl-R2~
25~ CC~2~C~2 I X~B~ R2 I
X COC~2C3~2 (3) X-Br; I 2~C~
X R2 (4) XsCl~ R1~2~
(5) X~C17 2~3 and 6 ) XDC~ Lo 3 I Eye with a polythiol in an amount so as to provide I to 0.~5 equivalents SH/equivalent of car~on-to-carbon double bond in the tetrahalvphthalate at a temperature in the range 60 to 150C.
ENTAILED DESCRIPTION CF~It~r INvrN~
It is an object of the present invention to drop a W curable composition suitable for coatings for electronic circuitry.
It is a further object of the present invention Jo develop W curable electronic circuit coatings which are characterized by an acceptable degree of flame retardant These and other objects will become obvious as the description of the invention proceeds.
According to the present invention tetrahalophthalic androids are converted to salts in base and reacted with ally chloride anger ~e~hallyl chloride in the presence of copper/cuprous chloride catalyst Jo give allyl/m2thallyl tetrahalophthalate esters in high yield and purity.
- pa-Z~;~96 Compounds covered by the present disclosure have the following structure:
where X O R (1) X=Br; Rl=R2=H
X n I I X=Br; Rl=R2=C~3 X CCH2C SHEA (3) Or ; R2=CH3 X R2 I X=Cl; Rl=R2=~
(5) X=C1, Rl=R2=C~3 and (6) X=Cl; lo R2=CH3 While compound 1 is a known compound (taught in U. S. Patent 4,105,710), compounds 2 through 6 are not documented in the prior art. U. S. Patent 3,035,084, while teaching preparation of the methallylic phthalate, as in the case of compound 5, does not teach the preparation of a halogenated methallylic phthalate, and, furthermore, synthesis of any of these halogenated compounds 1 through 6 by use of copper/cuprous chloride catalyst and by the reaction method described is also not disclosed in the prior art even though use of the catalyst and the reaction method are known for synthesis of non-halogenated phthalates as evidenced by the patents ; referred to under background of the Invention'.
These pylons, which are crystalline solids, are prereacted with a substoichiometric amount of polythiol in I the presence of a free radical thermal initiator, e. g., benzopinacol to give a liquid mixture. This mixture is then formulated with additional polythiol and optionally a photo initiator and other additives to make screenable - liquids which can be applied to electronic circuit boards . and cured with W light to hard fire-retardant coating.
The use of benzopinacol to prereact a pylon with a substoichiometric amount of a pothole is disclosed in Us S. Patent 4,020,233.
_ 5 _ I
Polythiols operable herein are simple or complex organic compounds having a multiplicity of pendant or terminally positioned ASH functional groups per average molecule.
The polythiol must contain 2 or more ASH groups/
molecule and have a viscosity range of essentially 0 to 20 million centipoises (cups) at 70C as measured by a Brook field Viscometer either alone or when in the presence of an inert solvent, aqueous dispersion or plasticizer.
Operable polythiols in the instant invention usually have molecular weights in the range of about 34 to about 20,000 and preferably, from about 100 to about 10,000.
The polythiols operable in the instant invention may - be exemplified by the general formula R8-(SH)n where n is at least 2 and R8 is a polyvalent organic moiety free from reactive carbon-to-carbon unsaturation. Thus, R8 may contain cyclic groupings and hotter atoms such as N, P or O and primarily contains carbon-carbon, carbon-hydrogen, carbon-oxygen or ~ilicon-oxygen containing chain linkages free of any reactive carbon-to-carbon unsaturation.
One class of polythiols operable herein are esters of i thiol-containing acids of the formula ~S~Rg~COOH where Rug is an organic moiety containing no reactive carbon-to-carbon unsaturation with polyhydroxy compounds of structure Rlo-(OH)n where Rio moiety containing no reactive carbon-to-carbon j unsaturation, and n is 2 or greater, These components will react under suitable conditions to give a polythiol having tune general structure:
R It --R
I/
Al where Rug and Rio are organic moieties cuntainin~ no I
reactive carbon-to-carbon unsaturation, and n is 2 or greater.
Polythiols such as the aliphatic monomeric polythiols methane ditniol, hexamethylene deathly, decamethylene deathly, tolylene-2,4-dithiol and the like) are operable herein. Examples of the polythiol compounds preferred include, but are not limiter to, esters of thioglycilic acid (HS-CH2COOH), alpha-mercaptopropionic acid (HS-CH(CH3)-COOH and beta-mercaptopropionic acid (HS-CH2CH2COO~) with polyhydroxy compounds such as glycols, trios, tutorials, ponytails, hexaols and the like. Specific examples of the preferred polythiols include, but are not limited to, ethylene glycol bis(thioglycolate), ethylene glycol bus (beta-mercapto-preappoint), trimethylolpropane iris (thioglycolate), trimethylolpropane tris-(beta-mercaptopropionate), pentaerythritol tetrakis (thioglycolate) and pentaerythritol tetrakis (beta-mercaptopropionate), all of which are commercially available. A specific example of a preferred polymeric polythiol is polypropylene ether glycol bis(beta-mercaptopropionate~ which is prepared from polypropylene-ether glycol ye. 9., Pluracol P2010, ! Wyandotte Chemical Corp.) and beta-mercaptopropionic acid by esterification.
Polythiol terminated polyoxyalkylene polyols, such as i trimethylolpropane tris-(3-mercapto-2-hydroxypropyl-monooxypropyl~ ether and trimethylolpropane iris-(3-mercapto-2-hydroxypropyl-dioxypropyl) ether, are also operable. Furthermore, saturated alicyclic deathless, such as 1,5-cyclooctanedithiol, 3,7,11-trimethyl-1,5-cyclododecanedithiol, 4-hexyl-1,2-cyclohexanedithiol, ethylcyclohexyl deathly and d-limonene deathly represent commercially available deathless that are operable herein.
I
Additionally, polythiols operable herein to give cured solid polythioether products with the pylon in the presence of a photo initiator include the mercaptoester derivatives of styrene-allyl alcohol copolymers set owlet in U. S. Patent 3,904,499 and the isocyanurate containing polythiols disclosed in U. S. Patent 3,~76,440 and liquid thiol-terminated polymers made in accord with Us S.
Patent 3,258,495.
An example of the aforesaid latter type liquid they'll-terminated polymer is CAPTURE 3-800, commercially available from Diamond Shamrock Chemical Company.
In carrying out the reaction to transform the crystalline solid pylons to a chain-extended, polythio-ether containing liquid by reaction with a polythiol in the presence of a free radical thermal initiator, the amount of polythiol used is a substoichiometric amount.
sufficient polythiol must be used to convert the solid crystalline pylon to liquid polythioether but care must be exercised that no too much polythiol is added which could increase viscosity too much or cause golfing. It has been found that a range of 0~1 to 0.25 equivalents SH/equivalent of double bond in the pylon is operable to satisfy the aforesaid requirements. Following the chain extending reaction, additional polythiol is added to the I - system to supply the stoichiometric amount necessary to react with the remaining carbQn-to-Carbon double bonds in the chain-extended pylon optionally along with a photo initiator for use as a photo curable composition.
The chain-extending reaction is performed at temperatures above the melting point of the pylon and the disassociation temperature of the free radical thermal initiator. Temperatures in the range 60 to 150C are usually employed.
* Trademark , The free radical, thermal initiators used herein are selected from substituted or unsubs~ituted pinnacles, ago compounds, thrums, organic peroxides and mixtures thereof.
S The organic peroxides operable are of the general formula:
( 1 on wherein n = 0 or 1, R is independently selected from hydrogen aureole, alkyd, aureole carbonyl, alkaryl carbonyl, aralkyl carbonyl and alkyd carbonyl and Al is alkyd or aureole, said alkyd groups containing 1 to 20 carbon atoms.
Examples of operable organic peroxides include t but are not limited tol2,5-dimethyl-2,5-di(t-butylperoxy)-hexane, 1,3-bis(t-butylperoxyisopropyl)benzene, Boyce-(cumylperoxyisopropyl)benzene, 2,4-dichloroben20yl peroxide, caprylyl peroxide, laurel peroxide, t-butyl peroxyisobutyrate, bouncily peroxide, p-chlorobenzoyl peroxide, hydroxyheptyl peroxide, di-t-butyl doper-phthalate, t-butyl pleracetate, t-butyl perbenzoate, dicumyl peroxide t l,l-di(t-butylperoxy~-3,3,5 Tramiel-cyclohexane and di-t-butyl peroxide.
Examples of ago compounds operable herein include, but are not limited to, commercially available compounds such as 2-t-butylazo-2-cyanopropanè; 2,?'-azobis~2~4-dimethyl-4-methoxy-valeronitrile); 2,2'-azobis(isobutyronitrile);
2,2'-azobis(2,4-dimethylvaleronitrile) and l,l'-azobis-(cyclohexanecarbonitrile~.
The thrums operable as thermal initiators herein are of the formula:
I C-S-S C-N
wherein Al, R3, R3 and R4 taken singly can be hydrogen, linear or branched alkyd having from 1 to about 12 carbon atoms, linear or branched alkenyl having from 2 to about 12 carbon atoms, cycloalkyl having from 3 to about 10 ring carbon atoms, cycloalkenyl having from 3 to about 10 ring carbon atoms, aureole having from 6 to about 12 ring carbon atoms, alkaryl having from 6 to about 12 ring carbon atoms, aralkyl having from 6 to about 12 ring carbon atoms and, when taken together, Al and R2 and R3 and R4 can each be a diva lent alkaline group (-CnH2n-) having from 2 to about 12 carbon atoms, a diva lent alkenylene group (-CnH2n 2-) group . having from 3 to about 10 carbon atoms, a diva lent alkadienylene group -(CnH2n-4)- having from 5 to about 10 carbon atoms, a diva lent alkatrienylene group -(C Ho 6)- having from 6 to about 19 carbon atoms, a diva lent alkyleneoxyalkylene group (-CxH2xOLCxH2x-) having a total of from 4 to about 12 carbon atoms or a diva lent alkyleneaminoalkylene group:
( - CXH 2XNCX~ 2x having a total of from 4 to about 12 carbon atoms.
Operable thrums include, but are not limited to, tetramethylthiuram disulfide, tetraethylthiuram disulfide, di-N-pentamethylenethiuram disulfide, tetrabutylthiuram disulfide, dipehnyldimethylthiuram disulfide, diphenyl-diethylthiuram disulfide and diethyleneoxythiuram disulfide and the like.
I
The substituted or unsubstituted pinnacles operable herein as a thermal initiator have the general formula:
RlP'3 X Y
wherein Al and R3 are the same or different substituted or unsubstituted aromatic radicals, R2 and R4 are substituted or unsubstituted aliphatic or aromatic radicals and % and Y which may be the same or different are hydroxyl, alkoxy or airlocks.
Preferred pinnacles are those wherein Al, R2~ R3 and R4 are aromatic radicals, especially phenol radical and X and Y are hydroxyl.
Examples of this class of compounds include, but are not limited to, benzopinacol, 4,4'-dichlorobenzopinacol 4,4'-dibromoben~opinacol, 4/4'-diiodobenzopinacol, 4,4',4'l,4"'-tetrachlorobenzopinacol, 2,4,2l,4'-tetrachloro-benzopinacol, 4,4'-dimethylbenzopinacol, 3,3'-dimethyl-benzopinacol~ 2~2'-dimethylbenzopinacol, twitter-methylbenzopinacol, 4,4'-dimethoxybenzopinacol, 4,4.,4 n 4 n -tetramethoxybenzopinacol, 4,4'-diphenyl-benzopinacol, 4,4'-dichloro-4~,4"'-dime~hylbenzopinacol, 4,4'-dimethyl-4",4"'-diphenylbenzopinacol~ xanthonpinacol, fluorenonepinacol, acetophenonepinacol, 4,4'-dimethylaceto-phenone-pinacol, 4~4'~dichloroacetophenonepinacol, 1,1,2-triphenyl-propane-1,2-diol, 1,2,3,4-~etraphenyl-butane-2,3-diol, 1,2-diphenylcyclobutane-1,2-diol, propiophenone-pinacol r 4 4'-dimethylpropiophenone- -pinnacle, 2,2'-ethyl-3,3'-dimethoxypropiophenone-pinacol, 1,1,1,4,4,4-hexafluoro-2,3-diphenyl~butane-2,3-dioof.
i99~
As further compounds according to the present invention, there may be mentioned: benzopinacol-mono-methyl ether, benzopinacol-mono-phenylether, benzopinacol and monoisopropyl ether, benzopinacol monoisobutyl ether, benzopinacol moo (diethoxy methyl) ether and the like.
The aforementioned free radical, thermal initiators are added to the composition in amounts ranging from 0.01 - 1.0% by weight based on the weight of the pylon and polythiol.
The compositions of the present invention may, if desired, include such additives as antioxidant, accelerators, dyes, inhibitors, activators, fillers, pigments, antistatic agents, flame-retardant agents, thickeners, thixotropic agents, surface-active agents, viscosity modifies, extending oils, plasticizers, tackifiers and the like within the scope of this invention. Such additives are usually preblended with the ethylenically unsaturated compound or polythiol prior to or during the compounding step. Operable fillers include natural and synthetic resins, carbon black, glass fibers, - wood flour, clay, silica alumina, carbonates, oxides, hydroxides, silicates, glass flakes, glass beads, borate, phosphates, diatomaceous earth, talc, kaolin, barium sulfate, calcium sulfate, calcium carbonate, antimony oxide and the like. The aforesaid additives may be present in quantities up to 500 parts or more per 100 parts of ethylenically unsaturated compound and polythiol by weight and preferably about 0.005 to about 300 parts on the same basis.
The curing reaction to form hard, fire-re~ardant coatings on substrates is preferably but not necessarily, carried out in the presence of a photo initiator. Various photo initiators operable herein include, but are not limited to, benzophenone, acetophenone, o-methoxybenzo-phenone, acenapthene-quinone, methyl ethyl kitten, valerophenone, hexanophenone, alpha-phenylbutyrophenone, p-morpholinopropiophenone, dibenzosuberone, 4-morpholino-benzophenone, 4'-morpholinodeoxybenzoin, p-diacetyl-Bunsen, 4-aminobenzophenone, 4'-methoxyacetophenone, benzaldehyde, alpha-tetralone, 9-acetylphenanthrene, 2-acetylphenanthrene, 10-thioxanthenone, acutely-phenanthrene, 3-acetylindole, 9-fluorenone, Linda none 1j3,5-triacetylbenzene, thioxanthen-9-one, xanthrene-9-one, 7 H-benz[de]anthracen-7-one, l-naphthalaehyde, 4,4'-bis(dimethylamino) benzophenone, fluorene-9-one, l'-acetonaphthone, 2'-acetonaphthone, buttondown, triphenylphosphine, tri-o-tolyphosphine, acetonaphthone, buttondown, benz[a]anthracene-7.12-dione, etch Another class of photosensitizes is the Bunsen ethers, such as Bunsen methyl ether, Bunsen ethyl ether, Bunsen isopropyl ether and Bunsen isobutyl ether. The photosensitizes are usually added in an amount ranging from 0.0005 to 30~ by weight of the ethylenically unsaturated compound and the polythiol.
In addition, the halogenated ally compound in the composition of this invention can act as its own photo initiator, without added photo initiator of the above types.
When US radiation is used, an intensity of 0.0004 to 60.0 watts~cm in the 250-400 nanometer region is usually employed.
The curing reaction can alto be accomplished by using high energy ionizing radiation at a dose rate in the range 0.00001 to 1,000 megarads/second.
The amount of ionizing radiation which is employed in curing in the instant invention can vary between broad limits. Radiation dosages of less than a megarad up to 10 megarads or more for electrons are operable; preferably 0002 to 5 megarads energy absorbed are employed.
The following examples will aid to explain, but specifically not limit, the subject invention unless, otherwise noted, all parts and percentages are by weight.
Example 1 Synthesis of Delilah Tetrabromophthalate (DATBP) A mixture of 464 g tetrabromophthalic android, 80 9 sodium hydroxide, 650 ml water, 0.04 g copper powder, 2 9 cuprous chloride and 306 g ally chloride was stirred 2 hours at 70C to give 528 g (94~) Delilah te~rabromo-phthalate. The pi was kept between 6.5 and 7.5 by adding sodium hydroxide solution during the reaction.
Example 2 Dimethallyl tetrabromophthalat~ (DMATBP) was synthesized in a similar manner as set out in Example 1 by using methallyl chloride in place of ally chloride.
Example A mixture of ally methallyl tetrabromopnthalate, - 20 DATBP and DMATBP was synthesized in a similar manner as set out in Example 1 by using a mixture of methallyl chloride and ally chloride.
Delilah tetrachlorophthalate was synthesized by the same procedure in Example 1 using te~rachlorophthalic android in place of tetrabromophthal~c android.
Example 5 A mixture of 5~G g Delilah tetrabromophthalat~ 5.25 g of dimethallyl tetrabromophthalate, 10.0 g Delilah tetrachlorophthalate, 2.4 g ethylene glycol bis-(3-mercaptopropiona~e) and 0.16 g benzopinacol was heaved for 30 minute at 110C to form a chain-extended, liquid polymer. Thereafter at awoke, 9.1 g ethylene glycol byway mercaptopropionate) and 9.52 g of finely divided hydrated alumina HYDRA 710 from Alcoa) was added and mixed.
This formulation was shown to screen-print well, to photo cure fast and to exhibit good solder resistance and, S most importantly, testing of 2 ten-mil thick films have revealed it to be flame-retardant as reflected by an average Oxygen Index of 29.
In general, flame retardancy is measured by ASTM
Method D 2863-74 for oxygen index; an oxygen index of about 27-28 or higher is considered generally acceptable.
While suitable for application to electronic circuit boards, other applications for this composition may be easily envisaged where radiation curable fire-retardant coatings are required.
Variations may be made in materials, proportions and procedures without departing from the scope of this invention.
Example 6 2.09 g of Delilah tetrabromophthalate from Example l and 0.91 g of pentaerythritol tetrakis(beta-mercapto-preappoint) were mixed in a 13 mm test tube and slowly melted at 80-85C to a clear solution The solution was transferred to a glass plate and spread as a 20 mix thick film thereon. The film was exposed to W radiation from a Ferry W lamp for l minute. A solid, cured film resulted.
Example 6 was repeated except that a photo initiator, i. e., 0.03 g of 2,2-dimethoxy-2-phenylacetophenone, was added to the system. solid, cured film resulted.
example 8 Example 6 way repeated except that a photo initiator, it e., 0.03 g of dibenzosuberone, was added to the system. A solid, cured film resulted I
Example 9 Example 6 was repeated except that a photo initiator, i. e., 0.03 g of 4,4'-dimethoxybenzophenone, was added to the system. A solid, cured film resulted.
Example 10 example 6 was repeated except that a photo initiator, i. e., 0.03 9 of benzophenone, was added to the system. A
solid, cured film resulted.
Example 11 Example 6 was repeated except that Owe g of buoyancy-pinnacle was added to the original mixture and, after formation ox the thioether-containing chain-extended pylon, 0.03 9 of 2,2-dime~hoxy-2-phenylacetophenone was added prior to irradiation. A solid cured film resulted.
Example 12 A mixture of 20.48 g of Delilah tetrachlorophthalate, 2.06 g pentaerythritol tetrakis(beta-mercaptopropionate) and 0.01 g benzopinacol were heated with stirring at 125C
for 1 hour to form a chain-extended, liquid polymer. The polymer was cooled to 60C and 3.26 g of 2,2-dimethoxy-2-phenylacetophenone, 0.03 g of pyrogallol and OOZE g of phosphorous acid were added to the system along with 10.28 9 of pentaerythritol tetrakis(beta Marquette-preappoint). This admixture was spread as a 20 mix thick coat on a glass plate and exposed to US radiation for 2 1/2 minutes. A solid, cured, transparent coating adhering to the glass plate re~ultedQ
Claims (8)
1. A flame retardant, photocurable composition comprising (1) a liquid, chain-extended, thioether-containing allylic or methallylic tetrahalophthalate or a mixture thereof, and (2) a polythiol.
2. The composition of Claim 1 also containing a photoinitiator.
3. The composition of Claim 1 wherein the tetrahalo-phthalate has the structure:
where (1) X=Br; R1=R2=H
(2) X=Br; R1=R2-CH3 (3) X Br; R1 H; R2 C 3 (4) X=Cl; R1=R2=H
(5) X=Cl; R1=R2=CH3 and (6) X=Cl; R1=H; R2=CH3
where (1) X=Br; R1=R2=H
(2) X=Br; R1=R2-CH3 (3) X Br; R1 H; R2 C 3 (4) X=Cl; R1=R2=H
(5) X=Cl; R1=R2=CH3 and (6) X=Cl; R1=H; R2=CH3
4. The process of forming a liquid, chain-extended thioether-containing allylic or methallylic tetrahalo-phthalate which comprises reacting a solid member of the tetrahalophthalate group of the formula:
where (1) X=Br; R1=R2=H
(2) X=Br; R1=R2=CH3 (3) X=Br; R1=H; R2=CH3 (4) X=Cl; R1=R2=H
(5) X=Cl; R1=R2=CH3 and (6) X=Cl; R1=H; R2=CH3 with a polythiol in an amount so as to provide 0.1 to 0.25 equivalents SH/equivalent of carbon-to-carbon double bond in the tetrahalophthalate at a temperature in the range 60 to 150°C.
where (1) X=Br; R1=R2=H
(2) X=Br; R1=R2=CH3 (3) X=Br; R1=H; R2=CH3 (4) X=Cl; R1=R2=H
(5) X=Cl; R1=R2=CH3 and (6) X=Cl; R1=H; R2=CH3 with a polythiol in an amount so as to provide 0.1 to 0.25 equivalents SH/equivalent of carbon-to-carbon double bond in the tetrahalophthalate at a temperature in the range 60 to 150°C.
5. The process according to Claim 4 wherein a free radical thermal initiator is added to the system.
6. The process according to Claim 5 wherein the free radical thermal initiator is benzopinacol.
7. process for forming a coating on a substrate which comprises applying to a substrate a flame-retardant, photocurable composition comprising (1) a liquid, chain-extended, thioether-containing allylic or methallylic tetrahalophthalate or a mixture thereof and (2) a polythiol and, thereafter, subjecting said coated substrate to UV radiation.
8. The process according to Claim 7 wherein the composition also contains a photoinitiator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US39556582A | 1982-07-06 | 1982-07-06 | |
| US395,565 | 1982-07-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1226996A true CA1226996A (en) | 1987-09-15 |
Family
ID=23563578
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000423459A Expired CA1226996A (en) | 1982-07-06 | 1983-03-11 | Fire-retardant photopolymers |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA1226996A (en) |
| DE (1) | DE3323222A1 (en) |
| FR (1) | FR2529901B1 (en) |
| GB (1) | GB2123431B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4591522A (en) * | 1985-01-04 | 1986-05-27 | W. R. Grace & Co. | Liquid photopolymers curable to fire-retardant, hydrolysis resistant compositions |
| US6479622B1 (en) | 1999-05-10 | 2002-11-12 | 3M Innovative Properties Company | Compositions for making ene-thiol elastomers |
| AU2022222668A1 (en) * | 2021-02-16 | 2023-08-17 | Prc-Desoto International, Inc. | Compositions containing a free radical polymerization initiator |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4139385A (en) * | 1975-06-20 | 1979-02-13 | General Electric Company | Coating method and composition using cationic photoinitiators polythio components and polyolefin components |
-
1983
- 1983-03-11 CA CA000423459A patent/CA1226996A/en not_active Expired
- 1983-06-28 DE DE19833323222 patent/DE3323222A1/en not_active Withdrawn
- 1983-07-01 GB GB08317872A patent/GB2123431B/en not_active Expired
- 1983-07-05 FR FR8311176A patent/FR2529901B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2123431B (en) | 1985-10-09 |
| FR2529901B1 (en) | 1986-02-14 |
| DE3323222A1 (en) | 1984-01-12 |
| FR2529901A1 (en) | 1984-01-13 |
| GB8317872D0 (en) | 1983-08-03 |
| GB2123431A (en) | 1984-02-01 |
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