CA1136600A - Safe, dry, free-flowing peroxide/aromatic carboxylic acid compositions - Google Patents
Safe, dry, free-flowing peroxide/aromatic carboxylic acid compositionsInfo
- Publication number
- CA1136600A CA1136600A CA000355772A CA355772A CA1136600A CA 1136600 A CA1136600 A CA 1136600A CA 000355772 A CA000355772 A CA 000355772A CA 355772 A CA355772 A CA 355772A CA 1136600 A CA1136600 A CA 1136600A
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- Prior art keywords
- peroxide
- solid
- benzoic acid
- weight
- composition
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-
- 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
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
- C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/52—Polycarboxylic acids or polyhydroxy compounds in which at least one of the two components contains aliphatic unsaturation
- C08G63/54—Polycarboxylic acids or polyhydroxy compounds in which at least one of the two components contains aliphatic unsaturation the acids or hydroxy compounds containing carbocyclic rings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F4/00—Polymerisation catalysts
- C08F4/28—Oxygen or compounds releasing free oxygen
- C08F4/32—Organic compounds
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Polymerization Catalysts (AREA)
- Macromonomer-Based Addition Polymer (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A Safe, Dry and Free-Flowing Solid Peroxide/
Aromatic Carboxylic Acid Composition is prepared by mixing the solid peroxide, such as diacyl peroxide, dialkyl peroxydicarbonate, dialkyl peroxide or alkylidene diperoxide, which melts above 30°C, with a solid aromatic carboxylic acid, particularly unsubstituted or alkyl-substituted benzoic acid, which melts above 40°C. This solid peroxide composition is used as an initia-tor for the polymerization of ethylenically unsaturated monomers, such as sytrene, and for curing of unsaturated polyester resins and diethylene glycol bis(allyl carbonate).
This solid peroxide composition exhibits improved safety characteristics such as delayed ignition times when in contact with a flame and increased thermal stabilities compared to similar prior art peroxide formulations.
A Safe, Dry and Free-Flowing Solid Peroxide/
Aromatic Carboxylic Acid Composition is prepared by mixing the solid peroxide, such as diacyl peroxide, dialkyl peroxydicarbonate, dialkyl peroxide or alkylidene diperoxide, which melts above 30°C, with a solid aromatic carboxylic acid, particularly unsubstituted or alkyl-substituted benzoic acid, which melts above 40°C. This solid peroxide composition is used as an initia-tor for the polymerization of ethylenically unsaturated monomers, such as sytrene, and for curing of unsaturated polyester resins and diethylene glycol bis(allyl carbonate).
This solid peroxide composition exhibits improved safety characteristics such as delayed ignition times when in contact with a flame and increased thermal stabilities compared to similar prior art peroxide formulations.
Description
- 11366(~0 Safe, Dry, Free-Flowing Solid Peroxide/
Aromatic Carboxylic Acid Composition Background of the Invention Thi.s invention relates to peroxide/aromatic carboxylic acid compositions and methods of using these compositions in polymerization and crosslinking; more particularly, this invention relates to compositions of dry solid free-flowing peroxides having melting points greater than 30C, aromatic carboxylic acids with melting points above 40C and optionally a dust suppressant.
~ , This invention also comprehends processes for polymerizing ethylenically unsaturated monomers by polymerizing said monomers in the presence of an initiating amount of the above mentioned solid peroxide composition and for curing of unsaturated polyester resins and diethylene glycol bis(allyl carbonatej monomer by cross-linking in the presence of an initiating amount of the above mentioned solid peroxide composition.
Many peroxide compositions are described in the lo prior art, although none of them teaches the instant in-vention. U.S. Patent No. 3,538,011 describes solid, free-flowing stabllized compositions containing organic per-oxides and organic fillers and the methods for the production of these compositions. Organic peroxides employed in this patent for these organic peroxide/organic filler compositions are aromatic and aliphatic diacyl peroxides, ketone peroxides and peroxyesters that are solid at room temperature whereas, the organic fillers employed are solid plasticizers that are soluble in polyester resin masses and are solid at room temperature, such as dicyclohexyl phthalate (m.p., 63-5C). These organic fillers are claimed to reduce the explosiveness and the shock sensitivity of the organic peroxides employed. Nevertheless, these formulations with dibenzoyl peroxide were found to be thermally unstable stored at 113fi600 70C relatively short time periods (see ~xample X, infra). The prior art is also replete with many peroxide paste compositions containing one or more organic safety liquids and water. Although these peroxide pastes and suspensions are described to be safe and free-flowing, none of them teach the safe, dry, free-flowing solid peroxide/aromatic carboxylic acid composition of the present inven-tion that have been found to be significantly more permanently stable than similar prior art formulations and considerably more resistent to burning ignition. Moreover, the benzoic acid as a filler in the instant invention has no detrimental affects on the rate of solution of the formulation in ethylenically unsaturated monomers, such as styrene or in unsaturated polyester resins.
Statement of the Invention This invention is directed to a safe, free-flowing solid peroxide formulation consisting essentially of 40-85~ by weight of a solid peroxide having a melting point above 30C, preferably above 40C, 15-60~ by weight of a solid aromatic carboxylic acid having a melting point above 40C and 0.0 to 2.0% by weight of a dust suppressant. More particularly, the aforesaid aromatic carboxylic acid component is an unsubstituted or alkyl-substituted benzoic acid.
Detailed Description of the Invention It has now been discovered that a free-flowing, solid peroxide composition can be significantly safer with respect to burning ignition and thermal stability than 11366(~0 previous free-flowing, solid compositions of the prior art which contained the same level of the same solid peroxides.
A. Solid Peroxide Component of the Compositions The solid peroxide component of the invention compositions - have melting points above 30 C and come from the following peroxide classes:
1) Solid substituted and unsubstituted diacyl peroxides such as dibenzoyl peroxide (m.p., 106-7C), di-(2-methyl-lo benzoyl) peroxide (m.p., 54-55C), di-(methoxybenzoyl) peroxide (m.p., 126 C), di-(2-methoxycarbonylbenzoyl) peroxide (m.p., 80C), di-(2-benzylbenzoyl) peroxide (m.p., 72-3 C), di-(4-fluorobenzoyl) peroxide (m.p., 93 C), di-(3-chlorobenzoyl) peroxide (m.p., 122-3 C), di-(4-chlorobenzoyl) peroxide (m.p., 140-1 C), di-(2,4-dichlorobenzoyl) peroxide (m.p., 9g-lOa c) ~ dibenzoyl diperoxyadipate (m.p., 93-4 C), benzoyl octadecanoyl peroxide (m.p., 78-9 C),dilauroyl peroxide (m.p., 41-2 C), dihexadecanoyl peroxide (m.p., 67-8 C), di(chloroacetyl) peroxide (m.p., 85C), and di-(3-carboxypropionyl) peroxide (m.p., 125C). These and other solid diacyl peroxides melt-ing above 30C, can be found in the published art ~e.g.
D. Swern(editor), Organic Peroxides, Vol. 1, Wiley-Inter-science,New York,1970,Chapter I,"Organic Peroxides and Per-oxy Co~pounds - General Description", O.L. Mageli and C.S. Sheppard, Pages 66&67; and W. Cooper, J.Chem.Soc.,1951, pages 3106-13].
1136~iQO
Aromatic Carboxylic Acid Composition Background of the Invention Thi.s invention relates to peroxide/aromatic carboxylic acid compositions and methods of using these compositions in polymerization and crosslinking; more particularly, this invention relates to compositions of dry solid free-flowing peroxides having melting points greater than 30C, aromatic carboxylic acids with melting points above 40C and optionally a dust suppressant.
~ , This invention also comprehends processes for polymerizing ethylenically unsaturated monomers by polymerizing said monomers in the presence of an initiating amount of the above mentioned solid peroxide composition and for curing of unsaturated polyester resins and diethylene glycol bis(allyl carbonatej monomer by cross-linking in the presence of an initiating amount of the above mentioned solid peroxide composition.
Many peroxide compositions are described in the lo prior art, although none of them teaches the instant in-vention. U.S. Patent No. 3,538,011 describes solid, free-flowing stabllized compositions containing organic per-oxides and organic fillers and the methods for the production of these compositions. Organic peroxides employed in this patent for these organic peroxide/organic filler compositions are aromatic and aliphatic diacyl peroxides, ketone peroxides and peroxyesters that are solid at room temperature whereas, the organic fillers employed are solid plasticizers that are soluble in polyester resin masses and are solid at room temperature, such as dicyclohexyl phthalate (m.p., 63-5C). These organic fillers are claimed to reduce the explosiveness and the shock sensitivity of the organic peroxides employed. Nevertheless, these formulations with dibenzoyl peroxide were found to be thermally unstable stored at 113fi600 70C relatively short time periods (see ~xample X, infra). The prior art is also replete with many peroxide paste compositions containing one or more organic safety liquids and water. Although these peroxide pastes and suspensions are described to be safe and free-flowing, none of them teach the safe, dry, free-flowing solid peroxide/aromatic carboxylic acid composition of the present inven-tion that have been found to be significantly more permanently stable than similar prior art formulations and considerably more resistent to burning ignition. Moreover, the benzoic acid as a filler in the instant invention has no detrimental affects on the rate of solution of the formulation in ethylenically unsaturated monomers, such as styrene or in unsaturated polyester resins.
Statement of the Invention This invention is directed to a safe, free-flowing solid peroxide formulation consisting essentially of 40-85~ by weight of a solid peroxide having a melting point above 30C, preferably above 40C, 15-60~ by weight of a solid aromatic carboxylic acid having a melting point above 40C and 0.0 to 2.0% by weight of a dust suppressant. More particularly, the aforesaid aromatic carboxylic acid component is an unsubstituted or alkyl-substituted benzoic acid.
Detailed Description of the Invention It has now been discovered that a free-flowing, solid peroxide composition can be significantly safer with respect to burning ignition and thermal stability than 11366(~0 previous free-flowing, solid compositions of the prior art which contained the same level of the same solid peroxides.
A. Solid Peroxide Component of the Compositions The solid peroxide component of the invention compositions - have melting points above 30 C and come from the following peroxide classes:
1) Solid substituted and unsubstituted diacyl peroxides such as dibenzoyl peroxide (m.p., 106-7C), di-(2-methyl-lo benzoyl) peroxide (m.p., 54-55C), di-(methoxybenzoyl) peroxide (m.p., 126 C), di-(2-methoxycarbonylbenzoyl) peroxide (m.p., 80C), di-(2-benzylbenzoyl) peroxide (m.p., 72-3 C), di-(4-fluorobenzoyl) peroxide (m.p., 93 C), di-(3-chlorobenzoyl) peroxide (m.p., 122-3 C), di-(4-chlorobenzoyl) peroxide (m.p., 140-1 C), di-(2,4-dichlorobenzoyl) peroxide (m.p., 9g-lOa c) ~ dibenzoyl diperoxyadipate (m.p., 93-4 C), benzoyl octadecanoyl peroxide (m.p., 78-9 C),dilauroyl peroxide (m.p., 41-2 C), dihexadecanoyl peroxide (m.p., 67-8 C), di(chloroacetyl) peroxide (m.p., 85C), and di-(3-carboxypropionyl) peroxide (m.p., 125C). These and other solid diacyl peroxides melt-ing above 30C, can be found in the published art ~e.g.
D. Swern(editor), Organic Peroxides, Vol. 1, Wiley-Inter-science,New York,1970,Chapter I,"Organic Peroxides and Per-oxy Co~pounds - General Description", O.L. Mageli and C.S. Sheppard, Pages 66&67; and W. Cooper, J.Chem.Soc.,1951, pages 3106-13].
1136~iQO
2) Solid dialkyl peroxydicarbonates such as dibenzyl peroxydicarbonate (m.p., 101-2 C),dicyclohexyl peroxydi-carbonate (m.p., 46C), di-(cis-3,3,5-trimethylcyclohexyl) peroxydicarbonate (m.p., 81-2C), di-(4-t-butylcyclohexyl) peroxydicarbonate (m.p., 91-2C), dibornyl peroxydicar-bonate (m.p., 94-6QC), di-(2-phenoxyethyl) peroxydicar-bonate (m.p., 97-100C), di-n-tridecyl peroxydicarbonate (m.p., 43-5C)-and di-n-hexadecyl peroxydicarbonate (m.p., 52C). These and other solid dialkyl peroxydi-lo carbonates, melting above 30C, can be found in the publish-ed art e.g. Ref. 17B) [ D. Swern(editor), Organic Perox-ides,Vol. 1, Wiley-Interscience, N.Y.,1970,Chapter I, "Organic Peroxides and Peroxy Compounds - General Descrip-tion", O.L. Mageli et al, page 68.]
3) Solid ketone peroxides such as di-(l-hydroxycyclohexyl) peroxide (m.p., 69-71C), l-hydroxycyclohexyl- l-hydroper-oxycyclohexyl peroxide (m.p., 78C), di-(hydroperoxy-cyclohexyl) peroxide (m.p., 82-3C) and 3,5-dihydroxy-3,5-dimethyl-1,2-dioxolane (m.p., 80-2C).
4) Solid peroxyesters such as di-t-butyl diperoxytere-phthalate (m.p., 121-2 C), di-t-butyl diperoxysuccinate (m.p., 53-4 C), di-t-butyl diperoxyadipate (m.p., 42-3 C), di-t-butyl diperoxyphthalate (m.p., 48 C), t-butyl peroxy (3-carboxypropionate) (m.p., 55-6 C), t-butyl peroxy-(3-carboxy-2-propenoate) (m.p., 114-6 C) and 2,5-dimethyl-2~5-di(benzoylperoxy)hexane (m.p., 118C).
- 6 - 113660~
o These and other solid peroxyesters, melting above 30 C, can be found in the published art [e.g., Ref. D. Swern(editor), Organic Peroxides, Vol. 1, Wiley-Interscience, N.Y.,1970, Chapter I,"Organic Peroxides and Peroxy Compounds - Gen-eral Description", O. L. Mageli et al, Pages 75 to 78.]
- 6 - 113660~
o These and other solid peroxyesters, melting above 30 C, can be found in the published art [e.g., Ref. D. Swern(editor), Organic Peroxides, Vol. 1, Wiley-Interscience, N.Y.,1970, Chapter I,"Organic Peroxides and Peroxy Compounds - Gen-eral Description", O. L. Mageli et al, Pages 75 to 78.]
5) Solid alkyl hydroperoxides such as 2,5-dimethyl-2,5-dihydroperoxyhexane (m.p., 104-5C), 2,5~dimethyl-2,5-dihydroperoxy-3-hexyne (m.p., 107-gC), 2,7-dimethyl-2,7-dihydroperoxy-3,5-octadiyne (m.p., 95-7C), 1,4-di-(1-methyl-l-hydroperoxyethyl) benzene (m.p., 60-2C) and 1,3,5-tri-(1-methyl-l-Hydroperoxyethyl)benzene (m.p., 138 -40C).
6) Solid dialkyl peroxides such as di-cumyl peroxide (m.p., 39C), 1,4-di- [l-methyl-l-(t-butylperoxy)ethy~
benzene (m.p., 79~C), 1,3-di- [l-methyl-l-(t-butylperoxy)-ethyl] benzene (m.p., 49C), di(isopropyl-cumyl) peroxide (m.p., 70~C) and others that can be found in the published art [e.g.,D. Swern, Organic Peroxides, Vol. 1, Wiley-Interscience, N.Y., 1970, Chapter I, "Organic Perox-ides and Peroxy Compounds - General Description", O. L.
Mageli, et al, pages 41 to 48.]
B. Solid Benzoic Acid Component of the Com-~ositions The solid alkyl-substituted or unsubstituted benzoic acid component of the invention compositions are solids having melting points above 4~ C and are selected from the following:
~ .
~., 11366(~0 Benzoic acid (m.p., 122-3C), 2 methylbenzoic acid (m.p., 103-5C), 4-methylbenzoic acid (m.p., 180-2C), 2,4-dimethyl-benzoic acid (m.p., 127C) and 4-t-butylbenzoic acid (m.p., 164-5C).
C. Optional Dust Suppressants Suitable optional dust suppressants for the invention compositions are liquids such as mineral spirits or mineral oils having flash points above 100F, sucrose acetate isobutyrates and liquid plas-ticizers such as benzyl butyl phthalate, dibutyl phthalate and tricresly phosphate.
The compositions of typical peroxide formulations of this inven-tion are given in Table I.
D. Meth~ds for Preparation of Solid Peroxide Compositions Several procedures can be employed to prepare the solid, free-flowing peroxide/aromatic carboxylic acid compositions of this invention:
benzene (m.p., 79~C), 1,3-di- [l-methyl-l-(t-butylperoxy)-ethyl] benzene (m.p., 49C), di(isopropyl-cumyl) peroxide (m.p., 70~C) and others that can be found in the published art [e.g.,D. Swern, Organic Peroxides, Vol. 1, Wiley-Interscience, N.Y., 1970, Chapter I, "Organic Perox-ides and Peroxy Compounds - General Description", O. L.
Mageli, et al, pages 41 to 48.]
B. Solid Benzoic Acid Component of the Com-~ositions The solid alkyl-substituted or unsubstituted benzoic acid component of the invention compositions are solids having melting points above 4~ C and are selected from the following:
~ .
~., 11366(~0 Benzoic acid (m.p., 122-3C), 2 methylbenzoic acid (m.p., 103-5C), 4-methylbenzoic acid (m.p., 180-2C), 2,4-dimethyl-benzoic acid (m.p., 127C) and 4-t-butylbenzoic acid (m.p., 164-5C).
C. Optional Dust Suppressants Suitable optional dust suppressants for the invention compositions are liquids such as mineral spirits or mineral oils having flash points above 100F, sucrose acetate isobutyrates and liquid plas-ticizers such as benzyl butyl phthalate, dibutyl phthalate and tricresly phosphate.
The compositions of typical peroxide formulations of this inven-tion are given in Table I.
D. Meth~ds for Preparation of Solid Peroxide Compositions Several procedures can be employed to prepare the solid, free-flowing peroxide/aromatic carboxylic acid compositions of this invention:
- 7 -1136601~
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~ g os~ o ~o~o ~30 o ~ o ~ ~ ~ 3 3 o o o o o o ~ 3 ~ ~ 3 ~ ~ o~ o o o~
~3~333~ ~33333~ 3~3~3~3 ~ U~ .
U~
æ
2 ~ R æ ~ æ R ~
¢~a~c~ ~XZo~o~ ~3~?~
113~6(;~0 - 8a -â) ~
~ OOoOOOOOOOOOoo~ oO
3 ~ 3 ~ ~ 3 ~ u~ ~
2V` ~o~
2u~
.^ 4~
~ ~ 7 ~ ~ ~ 7 113~00 Procedure A
Wetted granular peroxide can be blended or mixed with an appropriate amount of a solid, granular aromatic carboxylic acid and optionally with an appropriate amount of dust suppressant until a uniform mixture is obtained.
Then the mixture can be tray dried or dried by other methods known in the art.
Procedure B
To a stirred aqueous slurry of granular peroxide is added o an appropriate amount of a solid, granular aromatic carboxylic acid, and optionally, an approrpiate amount of dust suppressant. A surfactant can also be optionally added to aid in forming a uniform aqueous slurry. After stirring for about 5 to 10 minutes, the solid is obtained by filtration or centrifugation and the wetted solid mixture is then dried.
Procedure C
To a stirred aqueous slurry of granular peroxide is added an appropriate amount of alkali metal salt of the solid aromatic carboxylic acid or aqueous solution thereof.
Optionally, an appropriate amount of surfactant and/or dust suppressant can be added. The mixture is then stirred until uniform and then an appropriate amount of mineral acid is added in order to precipitate the aromatic carboxylic acid. After stirring for about 5 to 10 minutes, the solid mixture is obtained by filtration or centrifuga-1~36600 tion and is dried. This procedure can also initially employ an alkaline peroxide slurry resulting from preparation of the solid peroxide. However, the product resulting must be water washed in order to remove impurities resulting from formation of the peroxide.
Procedure D
To an aqueous slurry of the granular peroxide, optionally containing a dust suppressant or a surfactant, is added a solution of the aromatic carboxic acid which employs a lo water soluble solvent such as acetone. The solid aromatic - carboxylic acid precipitates. The resulting slurry is stirred for 5 to 10 minutes and the dried product is obtained by initially filterlng or centrifuging followed by drying.
Procedure E
The solid peroxide and the solid aromatic carboxylic acid are dissolved in a common solvent such as acetone. The resulting solution then can either be:
a) Stripped to give a dry uniform solid mixture or, b) Added to stirred water in order to coprecipitate the two solid components and thus produce a uniform slurry of the composition. The product can then be isolated as described above. The optionally employed surfactant can be any nonionic surfactant such as a nonylphenoxy - . :
~13~ )0 polyethoxyethanol, anionic surfactant such as an alkali salt of an alky~laryl polyether sulfonate or a cationic surfactant such as an alkyldimethylbenzylammonium halide in which the alkyl group contains 10 to 20 carbons.
The invention peroxide compositions are useful as free- ;
radical inltiators in the bulk, emulsion, solution, or suspension pol:ymerization or copolymerization of ethylen-ically unsaturated monomers at suitable temperatures and pressures. Temperatures of 20 C to 250 C, preferably 30C to 200C and peroxide levels (on a pure basis) of 0.005 to 3%, preferably on 0.01 to 1%, by weight based on monomer, are normally employed in these polymerization processes. Ethylenically unsaturated monomers include olefins such as ethylene,propylene, styrene, alpha-methylstyrene, chlorostyrene, vinyltoluene, vinyl benzyl chloride, vinyl pyridine and divinylbenzene; diolefins, such as 1,3-butadiene, isoprene and chloroprene; vinyl esters, such as vinyl acetate, vinyl propionate, vinyl laurate, vinyl benzoate and divinyl carbonate; unsaturated nitriles,such as acrylonitrile and methacrylonitrile;
acrylic acid, methacrylic acid and their esters and amides, such as methyl, ethyl, _-butyl and 2-ethylhexyl acrylates and methacrylates, and acrylamide and metha-crylamide ;-maleic anhydride; maleic and fumaric acids and their esters; vinyl halo and vinylidene halo compounds, such as vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride and vinyldene fluoride; perhalo olefins, such as tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene; vinyl ethers, such as methyl vinyl ether, ethyl vinyl ether and _-butyl vinyl ether;
allyl esters, such as allyl acetate, allyl benzoate, diallyl phthalate, allyl ethyl carbonate, triallyl phosphate, dially fumarate and diallyl carbonate; acrolein;
methyl vinyl ketone; and mixture thereof.
The solid, free-flowing peroxide/aromatic carboxylic acid lo compositions of this invention are also useful for the curing of unsaturated polyester resin compositions.
Unsaturated polyester re~.~ns that can be cured by the peroxides of this invention usually consist of an unsaturated polyester and one or more polymerizable monomers. The unsaturated polyesters are, for instance, polyesters as they are obtained by esterifying at least one ethylenically unsaturated di- or polycarboxylic acid, anhydride or acid halide, such as maleic acid, fumaric acid, glutaconic acid, itaconic acid, mesaconic acid, citraconic acid, allylmalonic acid, allysuccinic acid, tetrahydrophthalic acid and others with saturated or unsaturated di- or polyols, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-pro-panediols, 1,2-, 1,3- and 1,4-butanediols, 2,2-dimethyl-1,3-propanediol, 2-hydroxymethyl-2-methyl-1,3-propanediol, 2-buten-1,4-diol, 2-butyn-1,4-diol, 2,2,4-trimethyl-1,3-~13~i60() pentanediol, glycerol, bisphenol A, mannitol and others.
Mixtures of such polyacids and/or mixtures of such poly-alcohols may also be used. The unsaturated di- or poly-carboxylic acids may be replaced, at least partly, by saturated polycarboxylic acids, such as adipic acid, succinic acid, sebacic acid and othersand/or by aromatic polycarboxylic acids, such as phthalic acid, trimellitic acid, pryomellic acid, isophthalic acid and terephthalic acid. The acids used may be substituted by groups such as halogen. Examples of such suitable halogenated acids are, for example, tetrachlorophthalic acid, 5,6-docarboxy-1,2,3,4,7,7-hexachlorobicyclo (2.2.1)-2-heptene and others.
The other component of the unsaturated polyester resin composition, the polymerizable monomer Or monomers, can be preferably ethylenically unsaturated monomers, such as styrene, chlorostyrene, vinyltoluene, divinylbezene, alphamethylstyrene, diallyl ~aleate, diallyl phthalate, dibutyl fumarate, acrylonitrile, triallyl phosphate, triallyl cyanurate,methyl acrylate, methyl methacrylate, _-butyl methacrylate, ethyl acrylate and others, or mixtures thereof, which are copolymerizable with said polyesters. A preferred resin composition contains as the polyester component the esterification product of 1,2-propylene glycol ~a polyalcohol), maleic anhydride (an anhydride of an unsaturated polycarboxylic acid) and phthalic anhydride (an anhydride of an aromatic dicarboxylic acid) as well as the monomer component, 113~600 styrene. Temperatures of about 10C to 200C and peroxide levels o~ about 0.05% to 5% or more by weight of curable unsaturated polyester resin are normally employed. The unsaturated polyesters described above can be filled with various materials such as sulfur, glass fibers, carbon blacks, silicas, metal silicates, clays, metal carbonates, antioxidants, heat and light stabilizers, sensitizers, dyes, pigments, accelerators, metal oxides, such as zinc oxide, blowing agents, etc.
In addition, the free-flowing solid peroxide compositions of this invention can be employed for vulcanizing natural ~ and synthetic rubbers, for curing of olefin copolymers and terpoly~ers, such as EPR (ethylene-propylene co-polymers~ and EPD~ (ethylene-propylene-diene terpolymer), for crosslinking of PE (polythylene), ethylene-vinyl acetate copolymers, silicon rubbers, styrene-butadiene rubbers and the like, in the presence or absence of additives and fill-ers such as sulfur, carbon blacks, silicas, clays, carbo-nates, antioxidants, heat and light stabilizers, sensiti-zers, dyes, accelerators, zinc oxide, oils, blowing agents, etc.
The invention peroxide compositions can additionally be employed for the curing of monomers such as diethylene glycol bis(allyl carbonate) (ADC) as well as other diallyl and polyally~l compounds. In these applications 0.1 to ~13~60~
10% or more of the invention composition, based on curable monomer, can be employed.
Other types of unsaturated resins can be cured using the compositions of this invention as curing catalysts. These resins, called unsaturated vinyl ester resins, consist of a vinyI ester resin component and one or more polymeri-zable monomer components. The vinyl ester resin component can be made by reacting a chloroepoxide such as epichloro-hydrin with appropriate amounts of a glycol such as lo bisphenol A ~2,2-di-(4-hydroxyphenyl)propane~, in the presence of a base such as sodium hydroxide, to yield a condensation product having terminal epoxy groups derived from epichlorohydrin. Subsequent reaction of the condensation product with polymerizable unsaturated carboxylic acids such as acrylic acid and methacrylic acid, in the presence or absence of acidic or basic catalysts, results in formation of a vinyl ester terminated resin component. Normally styrene is added as the poly-merizable monomer component to complete the preparation of the unsaturated vinyl ester resin. Temperatures of about 10C to 20GC and pure peroxide levels of about 0.05%
to 5% or more by weight of curable unsaturated vinyl ester resin compositions are normally employed for curing of the unsaturated vinyl ester resins. The unsaturated resin described above can be filled with the materials employed with the unsaturated polyester resin compositions described previously.
1~3~00 Description of Preferred Embodiments Example I Preparation of a 50% Dibenzoyl Peroxide/50%
Benzoic Acid Composition A reactor equipped with a high speed stirrer was charged with 200g of water and 80g of commercial, wet 78%
dibenzoyl peroxide and the mixture was stirred vigorously for an hour at 50C. The fine wet dibenzoyl peroxide was separated by filtration and was hand mixed with 50g of finely ground 20 mesh (0.85mm) benzoic acid and the lo resulting mixture was passed through a 50 mesh (0.30mm) screen. Obtàined was 116g of wet product. At 26 C
lOOg of the product was dried for 24 hours to yield 82g of free-flowing powder which had an assay of 50.5%
dibenzoyl peroxide. Preliminary burning tests were carried out on 5g samples of this product as well as on a commercial sample of 50% dibenzoyl peroxide/50% dicyclohexyl phthalate (DCHP). The results showed that the invention 50% dibenzoyl peroxide/50% benzoic acid composition was significantly more resistant to ignition than was the art 50% dibenzoyl peroxide/50% dicyclohexyl phthalate composi-tion.
113660~
Example II Preparation of 70% Dibenzoyl Peroxide/30%
Benzoic Acid Compositions A reactor equipped with a mechanical stirrer was charged with 310g of commercial wet 78% dibenzoyl peroxide,1500g of water, 104g (o.85 mole) Or granular benzoic acid and 72g (0.90 mole) of 50% aqueous NaOH solution at room temperature. The resulting slurry was acidiried by adding 63g (0.45 mole) of 70% sulfuric acid at room temperature. This resulted in precipitation of the ben-zoic acid onto the wet dibenzoyl peroxide. The resultlng wet composition was separated by filtration and was washed with water. The product was then dried at 26C for 24 hours to yield 330g of dry composition which contained 70.1% dibenzoyl peroxide.
Another sample of 70% dibenzoyl peroxide/30% benzoic acidwas prepared as above except that in this case solid sodium benzoate was added to the aqueous dibenzoyl peroxide slurry in place of the combination of benzoic acid and 50% aqueous NaOH solution. The resulting dry composition contained 70.4% by weight of dibenzoyl peroxide.
Preliminary burning tests were carried out on the two above samples of the 70% dibenzoyl peroxide/30% benzoic acid composition and on a commercial sample of a 70% dibenzoyl ~3~i6Q~
peroxide/30% dicyclohexyl phthalate composition. The results showed than our invention compositions, containing benzoic acid, exhibited delayed ignition and resistanee to burning; whereas, the art composition, containing dicyclohexyl phthalate, ignited immediately upon contact with a flame.
1~36i60(~
Example III Preparation of Other Dibenzoyl Peroxide/
Benzoic Acid Compositions Employing the acid precipitation processes described in Example II, several other dry free-flowing dibenzoyl peroxide/benzoic acid compositions were prepared which contained 30 to 85% dibenzoyl peroxide and 15 to 70%
benzoic acid. The burning characteristics of these invention compositions along with those for 98% dibenzoyl peroxide and for the 50% dibenzoyl peroxide/50% DCHP
lo and the 70% dibenzoyl peroxide/30% DCHP art compositions are summarized in Example III Table.
The burning tests were carried out on 5 gram samples of various dibenzoyl peroxide compositions. In the test a 5 gram sample was placed in an aluminum dish (40 mm in diameter and 12 mm high) and the flame from a gas jet was brought into contact with the composition. The ignition time (the time required for the sample to ignite after contact with the flame), the total burning test time (ig-nition time plus the burning time) and the flame height were noted.
113~60C~
Example III Table Burning Test Results (5 gram samples) Composition Compo- Ignit. Total Flame sition Dibenzoyl % Benzoic Assay, Time, Burn, Height Peroxide Acid % Secs. Secs. Ins.
85.5~1 8 54 80.7<1 10 48 74.71 32 48 70.52 40 48 65.82 108 42 60.73 133 36 55.24 140 36 50.618192 30 45.435185 24 40.348230 12 35.158317 12 30.360320 12 70% Dibenzoyl Peroxide/30% DCHP70.2 <1 21 48 50% Dibenzoyl Peroxide/50% DCHP51.3 ~1 ~300 30 98% Dibenzoyl Peroxide 99.1Cl <1 60 '' ' , The results in Example III Table show that almost all of the dibenzoyl peroxide/benzoic acid compositions exhibited delayed ignition whereas the art dibenzoyl peroxide compositions were considerably more hazardous since they ignited immediately.
113~600 Example IV: Preparation of a 50% Dibenzoyl Peroxide/
49.5% Benzoic Acid/0.5% Mineral Oil Composition To a reactor equipped with a mechanical stirrer was charged 207g of water, 76.9g. of commercial 78% wet dibenzoyl peroxide, 0.4g of a surfactant*, 59.4g of 20 mesh (o.85 mm) benzoic acid and an aqueous 10% mineral oil (MO) emulsion that was previously made by mixing 0.6g of MO with 0.2g of a surfactant* and 5.2g of water. The resulting mixture was stirred for 15 minutes at 12 to 15 C, lo then the product was separated by filtration and the product was washed with water. The product was then spread out in a tray and was allowed to air dry at 20-25C over a period of 24 hours. Obtained was 117g of the dry formu-lation, 50% dibenzoyl peroxide/49.5% benzoic acid/0.5% MO.
The assay of the product according to the "active oxygen"
content was 50.1%. The MO reduced the amount of dusting due to the presence of fine particles of dibenzoyl peroxide and benzoic acid that were in the formulation.
*The surfactant employed was prepared by adding 75g of a stripped coconut fatty acid mixture (e.g., Ashland's HYDROFOL(R)ACID 631) to 711g of aqueous 7.4% posassium hydroxide solution. The mixture was stirred at room temperature until a clear aqueous solution was obtained.
113~i600 A shaker vibration test was carried out on the composition that was produced. A 250 ml graduated cylinder was completely filled with the 50% dibenzoyl peroxide/49.5%
benzoic acid/0.5% MO formulation. The top of the cylinder was covered with polyethylene film in order to prevent loss of product during shaking and the filled graduated cylinder was taped vertically to a Tyler Sieve Shaker (Model RX~24, W. C. Tyler, Inc., Mentor, Ohio 44060) and the shaker was turned on. After various periods of shaking the material in the top and in the bottom of the cylinder was assayed for dibenzoyl peroxide content.
Example IV Table summarizes the results and shows that the original assay, and the top and bottom assays were Example IV Table Shaker Test Results - Assay Uniformities Dibenzoyl Peroxide Content, %
Shaking Time, hrs. Ori~inal Top Bottom 1.0 50.1 50.4 49.8 3.0 50.0 49.7 50.0 6.o 50.0 49.2 50.9 10.0 50.1 52.2 51.9 within analytical error of each other. Hence, the 50%
dibenzoyl peroxide/49.5% benzoic acid/0.5% MO formulation remained stable with respect to assay uniformity during at least 10 hours of shaking on a Tyler Sieve Shaker.
.:
113~
- 2~ -Example V: Pre~aration of an 85% Dibenzoyl Peroxide/14.5%
Benzoic Acid/0.5% MO Composition To a reactor equipped with a mechanical stirrer was charged 280g of water, lO9g of commercial 78% wet dibenzoyl per-oxide, 0.2g of a surfactant (described in Example IV), 14.5g of 20 mesh (0.85 mm) benzoic acid and 6g of an aqueous 10% MO emulsion (described in Example IV). The resulting mixture was stirred for 15 minutes at 12-15C, then the product was separated by filtration and the product was washed with water. The product was then spread out on a tray and was allowed to dry at 20-25C over a period of 24 hours. A white free-flowing powder was obtained which contained 85% dibenzoyl peroxide, 14.5% benzoic acid and 0.5% MO. The assay of the product according to "active oxygen" content was 85.3%.
113~600 Example VI: SPI Exotherms of Various Dibenzoyl Peroxide/
Benzoic Acid Co~positions Two unsaturated polyester resin compositions were employed in this example.
Resin Composition A
This unsaturated polyester resin was composed of an unsaturated polyester and styrene monomer. The unsaturated polyester was an alkyd resin made by esterfying the following components.
lo Component Quantity Maleic anhydride l.0 mole Phthalic anyhydride l.0 mole Propylene glycol 2.2 moles To the resulting resin was added 0.013% by weight of hydroquinone inhibitor. The alkyd resin had an Acid No.
of 45-50. Seven (7) parts by weight of the above polyester (alkyd resin) was diluted with three (3) parts by weight ~f monomeric styrene. The resulting unsaturated polyester resin had the following properties:
a. Viscosity (Brookfield No. 2 at 20 r.p.m.) 13.08 poise b. Specific gravity 1.14 1136~i00 Curing Procedure Gelation and cure characteristics of various initiators in the above unsaturated polyester resin were determined using the Standard SPI Exotherm Procedure ("SPI Procedure for Running Exotherm Curves-Polyester Resins"j published in the Preprint of the 16th Annual Conference - Reinforced Plastics Division, Society of the Plastics Industry, Inc., February, 1961).
Using the curing procedure described above at 93C (200F) the 50% dibenzoyl peroxide/49.5% benzoic acid/0.5% MO (A) composition of Example IV, the 85% dibenzoyl peroxide/14.5%
benzoic acid/0.5% MO (B) composition of Example V, commer-cial wet 78~ dibenzoyl peroxide and commercial 50~ dibenzoyl peroxide/50% dicyclohexyl phthalate (C) were evaluated as curing agents for Resin Composition A. The results are summarized in Example VI Table I and show that the instant invention compositions (A) and (B) cured the unsaturated polyester resin and had activities that were essentially the same as those of art composition (C) and commercial wet 78% dibenzoyl peroxide in Resin Composition A.
93C SPI Exotherm Data - Resin Composition A
Dibenzoyl Peroxide Peak Barcol Composition Level* ~ Gel,Mins. Cure,Mins. Exo.,F Hardness A 1.0 2.6 3.7 411 45 B 1.0 2.2 3.1 403 45 C 1.0 2.3 3.5 415 45 78~ Dibenzoyl Peroxide 1.0 2.4 3.6 413 45 *As pure dibenzoyl peroxide 113~i~00 Resin Composition B (DERAKANE 411-45) This unsaturated polyester resin was a corrosion resistant unsaturated polyester resin that was composed of a vinyl ester resin and styrene monomer. This resin, DERAKANE
411-45, was produced by the Dow Chemical Company. (see Dow Chemical Company Bulletin,"Derakane Vinyl Ester Resins for Corrosion Resistance", 1975).
The same curing procedure and the same dibenzoyl peroxide compositions as used for curing of Resin Composition A
lo were used ~or curing of Resin Composition B. The results are summarized in Example VI Table II and again show that the dibenzoyl peroxide compositions of the instant invention, e.g., (A) and (B), cured Resin Composition B and had activites that were essentially the same as those of art composition (C) and commercial wet 78% dibenzoyl peroxide, hence the aromatic carboxylic acid had no detrimental effect on the efficiency of the peroxide as a curing initiator ~or unsaturated polyester resins.
Example VI Table II
93C SPI Exotherm Data - Resin ComPosition B
Dibenzoyl Peroxide Le~el*,Gel, Cure, Peak Barcol Composi-tion % ~ins. Mins. Exo., F Hardness A 1.0 5.6 7.3 416 20-25 B 1.0 5.0 6.8 415 25-30 C 1.0 5.2 6.9 415 20-25 78% Dibenzoyl 1.0 5.5 7.3 416 20-25 Peroxide ~As pure dibenzoyl peroxide * ~ ,v~c~
, 113f~i6~0 Example VII: Ignition Times for Various Dibenzoyl Peroxide/Carboxylic Acid Formulations Several dry free-flowing dibenzoyl peroxide/carboxylic acid formulations were prepared by the procedures described in the previous Examples. Burning ignition times were then determined on these formulations.
The results are summarized in Example VII Table and Example VII Table Ignition Times of Various Dibenzoyl Peroxide/Carboxylic lo Acid Formulations Formulation Composition Filler Ignition Dibenzoyl m.p., Time, Peroxide, % Filler, % Cseconds 60% 2-Methylbenzoic Acid, 40% 103-5 28 60% 4-Methylbenzoic Acid, 40% 180-2 13 60% Benzoic Acid, 40% 122-3 3 70% Benzoic Acid, 30% 122-3 2 70% Stearic Acid, 30% 65-67~ 1 70% Azelaic Acid*, 30% 98-102C 1 70% DCHP, 30 63-5 ~1 ~ l,9-nonanedioic acid show that aromatic carboxylic acids such as benzoic acid, 2-methylbenzoic acid and 4-methylbenzoic acid caused the formulation to have desirable and safe delayed ~gnitions whereas the non-aromatic carboxylic acids such as stearic 1136~600 - 29 _ acid and azelaic acids failed to delay ignition of the compositions containing them. The results of this example demonstrate the general usefulness of aromabic carboxylic acids in the practice of this invention.
113~60V
Example VIII: Preparation of Peroxide/Benzoic Acid For-mulations Several room temperature stable solid dialkyl peroxydicar-bonates su~ as di-(2-phenoxyethyl) peroxydicarbonate (A-l) (m.p., 97-100C), di-(4-t-butylcyclohexyl) peroxydicarbonate (A-2)(m.p., 91-2C) and dibenzyl peroxydicarbonate (A-3) (m.p., 101-2C) and the solid dihydroperoxide, 2,5-dimethyl-2,5-dihydroperoxyhexane (A-4)(m.p., 104-5 C), in dry granular form were individually hand mixed with equal quantities of dry granular benzoic acid (m.p., 122-3 C) or dicyclohexyl phthalate (DCHP)(m.p., 65-5 C). The latter filler, DCHP, has been employed in prior art compositions whereas the former ~iller, benzoic acid, is employed in the compositions of this invention. Example VIII Table summarizes the burning ignition times for the above compositions and show that the 50% peroxide/50~ benzoic acid formulations of this invention resulted in much longer ignition times than the corresponding 50% peroxide/50% DCHP
formulations. Hence, the aromatic carboxylic acid fillers (e.g., benzoic acid) of the present invention are much safer fillers for peroxides than are prior art fillers (e.g., DCHP).
1~3~600 Example VIII Table lgnition Tlmes for Various 50% Peroxide/50% Filler Compositions Peroxide FillerIgnition Time, secs.
A-l Benzoic Acid 6 A-l DCHP 3 A-2 Benzoic Acid 8 A-3 Benzoic Acid 5 A-4 Benzoic Acid47 Dibenzoyl Peroxide Benzoic Acid18*
Dibenzoyl Peroxide DCHP C 1 *Data from Example III Table 113~600 Example IX: Preparation of a 70% Di-(2-methylbenzovl) Peroxide/30% Benzoic Acid Formulation Employing essentially the same procedure as used in Example V solid free-flowing 70~ di-(2-methylbenzoyl) peroxide formulations were prepared in which benzoic acid, an aromatic carboxylic acid filler of this invention, and DCHP, an art flller, were employed. Example IX Table shows that the composition containing benzoic acid gave a longer burning ignition time than did the composition locontaining the art filler (DCHP).
Example IX Table 70% Di-(2-methylbenzoyl) Peroxide Formulations Filler MeltingO Composition Filler Point, CBurning Ignition Time, secs.
Benzoic Acid 122-3 2 113~6(~0 Example X: Thermal Stabilities of Dibenzoyl Peroxide/
Benzoic Acid Formulations Several dibenzoyl peroxide/benzoic acid formulations of this invention and several dlbenzoyl peroxide/DCHP formulations of the art were stability tested at 50C, 60C and 70C.
Samples containing approximately lOg of each formulation were placed in ovens at 50C, 60C and 70C and the samples were held at these temperatures for various lengths of time. Example X Table summarizes the percent of assay lost for each of these formulations at the ends of the thermal stability tests. The results demonstrate that the dibenzoyl peroxide/benzoic acid formulations of this invention have significantly better thermal stabilities than the art dibenzoyl peroxide/DCHP formulations. The invention formulations lost very little assay when stored at 70C
whereas one of the art compositions decomposed completely at 70C and a second art composition decomposed violently at 70C. The practicaly implication of these thermal stability data is that the invention dibenzoyl peroxide formulations are safer to process, dry at elevated temperatures during manufacture, ship and store than are the prior art dibenzoyl peroxide/DCHP formulations.
1~3~i600 Example X Table Thermal Stabilities of Various Dibenzoyl Peroxide Formulations Formulation Composition Dibenzoyl Storage Duration % Assay Peroxide, % Filler Temp, C hrs. Lost Benzoic Acid, 50 50 240 0.4 DCHP, 50 50240 2.4 Benzoic Acid, 50 60 240 o.8 DCHP, 50 60240 100*
Benzoic Acid, 50 70 16 1.4 DCHP, 50 70 ~100**
Benzoic Acid, 30 50 120 0.1 DCHP, 30 50120 2.0 Benzoic Acid, 15 50 240 3-DCHP, 15 50240 12.9 Benzoic Acid, 15 60 240 8.4 DCHP, 15 60 48 19.1 D~HP, 15 60 120 100 Benzoic Acid, 15 70 6 0.5 DCHP, 15 70 2100***
* Sample decomposed completely and became liquid.
After 120 hrs./60C % assay lost was 18.4.
** Sample decomposed completely and became liquid.
***Sample exploded and destroyed testing oven after two hours at 70C.
1~35i601) Example XI: Vin~l Chloride Sus~ension Polymerization with a 50% Di-~2-phenoxyethyl) peroxydicarbonate/50% Benzoic Acid Com~osition Pure di-(2-phenoxyethyl) peroxydicarbonate (A-l) and the 50% A-1/50% benzoic acid composition of this inventi~n were evaluated as polymerization initiators at 55C for vinyl chloride suspension polymerizations in a PVC reactor.
The level of initiator that was employed on a pure basis was 0.10 parts per hundred based on vinyl chloride monomer and the pH of the suspensions was about 6.5. The experimental procedure employed is described below.
Suspension Polymerizations Polymerizations of vinyl chloride in suspension were carried out in a 1.5 liter reactor, which was designed and instrumented such ~hat the polymerization could be monitored calortmetrically. The reactor was immérsed in a water bath, maintained 0.5C above the desired reaction temperature, thus preventing any heat loss to the surroundings. The heat produced from the exothermic polymerization, plus the heat passed into the reactor from the water bath, was removed by the passage of cooling water thro gh internal coils in the reactor. Thus the temperature was kept constant. The flow rate of the coling water, and the temperature difference between entrance and exit streams were monitored, hence a continuous recording 1131~600 of heat removed (cal. min ) was obtained.
The pressure in the reactor was also continuously moni-tored. At about 70% conversion of monomer to polymer, the monomer in the vapor phase became depleted and the pressure fell. Thus, from a knowledge of the point of 70% conversion, and heat of polymerization of vinyl chloride (23 kcal/mole) it was possible to calculate the ~background count" in the calorimetric recording, this background being due to heat flow from the water bath to the reactor. By substrac~ion, the true rate of polymeri-- zation (cal. min 1), as a function of time, was obta~ned.
Suspension System Used pH~6.5) 1% solution of Aerosol MA 80%* 42 ml 1% solution of Methocel F 50** 168 ml Triply distilled water ~ 469 ml * Surfactant made by American Cyanamid Co. (sodium dihexyl succinate)Cr~
**Hydroxypropyl methyl cellulose polymer made by Dow Chemical C\~_~L~W~_~) Note: pH of the aqueous phase was measured at ambient temperatures, 22C, using a standard pH meter.
- ~7 -Example ~I Table sUmmarizes the time that was required for reachin~ the pressure drop (ca, 70% conversion of vinyl chloride monomer to pol~mer) when pure A-l and the 50% A-1/50% benzoic acid composition were employed.
Example XI Table Viny~l Chloride Suspension Polymerizations at 55C, pH 6.5 Level, Time to Pressure Drop Initiator Compos~tion phm* (~70% Conversion),Mins.
Pure A-l 0.10 340 50% A-1/50% Benzoic Acid 0.10 340 *Parts of pure peroxide per hundred monomer The results show that the 50% A-1/50% benzoic acid composition of this invention had the same efficien~y (on a pure basis) as pure A-l. Hence, the safe composition of this invention, such as 50% A-1/50% benzoic acid, can be employed as free-radical initiator compositions for polymerizing monomers, such as vinyl chloride, to polymers, hence the aromatic carboxylic acid had no detrimental effect on the efficiency of the peroxide as an initiator for vinyl monomer polymerizations.
11366~
EXAMPLE XII~: Curing of Dlethylene ~lycol Bis~allyl Carbonate~ w~th 8'5% Dlbenzoyl Peroxide/15% Benzoic Acid, 85%' D1'benzoy1 Peroxide/15% Dicyclohexyl Phthalate and 98% Di'be'nzo'y~l Peroxi'de Compositions Diethylene glycol bis(allyl carbonate), ADC,is a cross-linkable monomer, which then cured with free-radical curing agents, is finding increasing use in optical applications (safety glasses, safety shields, etc.) The only free-radical catalysts that have been found to satisfactorily cure ADC are dry 98% dibenzoyl peroxide and the low molecular weight peroxydicarbonates, diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate.
The latter initiators require refrigerated storage and care in handling whereas the former 98% dibenzoyl peroxide, although stable, requires extremely careful handling owing ~o its explosive burning hazard. Although commercial wet dibenzoyl peroxide formulations containing 22 to 33% water are resistant to burning the water in them causes problems such as gas bubbles and surface imper-fections when these wet dibenzoyl peroxide products are used for curing of ADC lenses.
~13ti6(~0 Various dry dibenzoyl peroxide compositions were employed for curing ADC. These c~mpositions were an instant invention compos~tion consisting of 85% dibenzoyl peroxide and 15% benzoic acid and art compositions such as dry 98% dibenzoyl peroxide and an 85% dibenzoyl peroxide/dicyclohexyl phthalate formulation.
Curing ~rocedure ~n the curing tests 0.125 inch thick lenses were cast in a curing cell consisting of two glass plates separated by~ a T~gon (trademark of the Norton Co., a clear, flexible vinyl acetate/vinyl chloride copolymer) gasket.
The glass plates were held in contact with the Tygon(R) gasket by means of four spring binder clips, one on each edge of the 4 inch x 4 inch cell. The catalyzed ADC
monomer was prepared by dissolving 1.772gof dibenzoyl peroxide (on a pure basis) in 50g of ADC. The catalyzed ADC was in~ected into the cell by means of a syringe. A
second syringe was used to allow the displaced air to escape.
The castings were polymerized in a hot air oven using the following time/temperature profile:
113~;6~0 _ 40 -Temperature (C~ Time, mins.
o 96 15 Thus, the total cure time was 6~2 hours. At the end of this period the cells were removed from the oven and allowed to cool to ambient temperature. The Barcol hardness and appearance of each casting were then deter-mined. Example XII Table summarizes the result of curing of ADC by the dibenzoyl peroxide compositions.
113f~6C~
Example XlI Table Curing of ADC with Dibenzoyl Peroxide Compositions (I.772g pure Dibenzoyl Peroxide/50g ADC) Dibénzoyl Peroxide Composition Hardness Appearance Dry 98% Dibenzoyl Peroxide 45-48 Good 85% Dibenzoyl Peroxide/15% 41-45 Good Benzoic Acid 85% Dibenzoyl Peroxide/15% 17-23 Poor*
Dicyclohexyl Phthalate lo *Uneven surface due to premature release from the glass surface of the mold.
The instant invention composition (85% dibenzoyl peroxide/
15% benzoic acid) cured the resin about as well as did dry 98% dibenzoyl peroxide. On the other hand the art composition, 85% dibenzoyl peroxide/15% dicyclohexyl phthalate, gave a poor quality lens as judged by hardness and surface quality. These results demonstrate that the safe dibenzoyl peroxide/benzoic acid compositions of this invention can be used for curing of ADC in place of hazardous dry 98% dibenzoyl peroxide whereas the art dibenzoyl peroxide/dicyclohexyl phthalate formulations cannot be used. Since dry 98% dibenzoyl peroxide is forbidden in transport in most of the countries of the world, the above results represent a significant advance in the art. They demonstrate that producers of ADC
lenses throughout the world can safely use the safe and stable dibenzoyl peroxide/benzoic acid compositions of 113~1600 this inventiGn in place of the hazardous dry 98%
dibenzoy~l peroxide and the hazardous and the thermally unstable low molecular weight liquid peroxydicarbonates for curing o~ ADC.
11366al0 Example XI~I: 50% Dialkyl Peroxide/50% Filler For~ulation~s Two dialky~l peroxides and two fillers were used to prepare four 50% dialkyl peroxide/50% filler compositions.
The dialkyl peroxides used were di-cumyl peroxide (A-5) (m.p., 39 C) and 1,3-di-[1-methyl-1-(t-butylperoxy)ethyl]-benzene (A-6) (m.p., 70 C) whereas~ the fillers were benzoic acid (m.p., 122-3 C) and dicyclohexyl phthalate (DCHP) (m.p., 63-5 C). The latter filler, DCHP, has been employed in prior art compositions whereas the former filler, benzoic acid, is employed in the compositions of this invention. The compositions were prepared by handmixing of equal parts of powdered dialkyl peroxide and powdered filler untll the compositions were uniform. The resulting 50% peroxide/50% filler compositions as well as pure A-5 and pure A-6 were evaluated in burning tests on 5 gram portions of each sample. The maximum flame heights of each composition were noted and the results are summarized in Example XIII Table.
1136~(~0 Example XIII Table Burning Tests on 50% Dialkyl Peroxide/50% Filler Compositions Dialkyl Maximum Peroxide, % Flame Height, ins.
A-5, 50 Benzoic Acid, 50 10 - 12 A-5, 5 DCHP, 50 24 A-5, 100 None 36 - 48 A-6, 50 Benzoic Acid, 50 14 - 16 lo A-6, 50 DCHP, 50 28 - 30 3 A-6, 100 None 36 The results show that both fillers (benzoic acid and DCHP) reduced the flame height of the peroxide burn, hence, both fillers reduced the explosive burning hazard of pure A-5 and A-6. However, the compositions of this invention (i.e., 50% A-5/50% benzoic acid and 50% A-6/50% benzoic acid) were significantly more effective in reducing the flame height and explosive burning hazard than were the compositions which used the art filler (i.e., 50%
A-5/50% DCHP and 50% A-6/50% DCHP).
U~
o E~ ~
~ g os~ o ~o~o ~30 o ~ o ~ ~ ~ 3 3 o o o o o o ~ 3 ~ ~ 3 ~ ~ o~ o o o~
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2 ~ R æ ~ æ R ~
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113~6(;~0 - 8a -â) ~
~ OOoOOOOOOOOOoo~ oO
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~ ~ 7 ~ ~ ~ 7 113~00 Procedure A
Wetted granular peroxide can be blended or mixed with an appropriate amount of a solid, granular aromatic carboxylic acid and optionally with an appropriate amount of dust suppressant until a uniform mixture is obtained.
Then the mixture can be tray dried or dried by other methods known in the art.
Procedure B
To a stirred aqueous slurry of granular peroxide is added o an appropriate amount of a solid, granular aromatic carboxylic acid, and optionally, an approrpiate amount of dust suppressant. A surfactant can also be optionally added to aid in forming a uniform aqueous slurry. After stirring for about 5 to 10 minutes, the solid is obtained by filtration or centrifugation and the wetted solid mixture is then dried.
Procedure C
To a stirred aqueous slurry of granular peroxide is added an appropriate amount of alkali metal salt of the solid aromatic carboxylic acid or aqueous solution thereof.
Optionally, an appropriate amount of surfactant and/or dust suppressant can be added. The mixture is then stirred until uniform and then an appropriate amount of mineral acid is added in order to precipitate the aromatic carboxylic acid. After stirring for about 5 to 10 minutes, the solid mixture is obtained by filtration or centrifuga-1~36600 tion and is dried. This procedure can also initially employ an alkaline peroxide slurry resulting from preparation of the solid peroxide. However, the product resulting must be water washed in order to remove impurities resulting from formation of the peroxide.
Procedure D
To an aqueous slurry of the granular peroxide, optionally containing a dust suppressant or a surfactant, is added a solution of the aromatic carboxic acid which employs a lo water soluble solvent such as acetone. The solid aromatic - carboxylic acid precipitates. The resulting slurry is stirred for 5 to 10 minutes and the dried product is obtained by initially filterlng or centrifuging followed by drying.
Procedure E
The solid peroxide and the solid aromatic carboxylic acid are dissolved in a common solvent such as acetone. The resulting solution then can either be:
a) Stripped to give a dry uniform solid mixture or, b) Added to stirred water in order to coprecipitate the two solid components and thus produce a uniform slurry of the composition. The product can then be isolated as described above. The optionally employed surfactant can be any nonionic surfactant such as a nonylphenoxy - . :
~13~ )0 polyethoxyethanol, anionic surfactant such as an alkali salt of an alky~laryl polyether sulfonate or a cationic surfactant such as an alkyldimethylbenzylammonium halide in which the alkyl group contains 10 to 20 carbons.
The invention peroxide compositions are useful as free- ;
radical inltiators in the bulk, emulsion, solution, or suspension pol:ymerization or copolymerization of ethylen-ically unsaturated monomers at suitable temperatures and pressures. Temperatures of 20 C to 250 C, preferably 30C to 200C and peroxide levels (on a pure basis) of 0.005 to 3%, preferably on 0.01 to 1%, by weight based on monomer, are normally employed in these polymerization processes. Ethylenically unsaturated monomers include olefins such as ethylene,propylene, styrene, alpha-methylstyrene, chlorostyrene, vinyltoluene, vinyl benzyl chloride, vinyl pyridine and divinylbenzene; diolefins, such as 1,3-butadiene, isoprene and chloroprene; vinyl esters, such as vinyl acetate, vinyl propionate, vinyl laurate, vinyl benzoate and divinyl carbonate; unsaturated nitriles,such as acrylonitrile and methacrylonitrile;
acrylic acid, methacrylic acid and their esters and amides, such as methyl, ethyl, _-butyl and 2-ethylhexyl acrylates and methacrylates, and acrylamide and metha-crylamide ;-maleic anhydride; maleic and fumaric acids and their esters; vinyl halo and vinylidene halo compounds, such as vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride and vinyldene fluoride; perhalo olefins, such as tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene; vinyl ethers, such as methyl vinyl ether, ethyl vinyl ether and _-butyl vinyl ether;
allyl esters, such as allyl acetate, allyl benzoate, diallyl phthalate, allyl ethyl carbonate, triallyl phosphate, dially fumarate and diallyl carbonate; acrolein;
methyl vinyl ketone; and mixture thereof.
The solid, free-flowing peroxide/aromatic carboxylic acid lo compositions of this invention are also useful for the curing of unsaturated polyester resin compositions.
Unsaturated polyester re~.~ns that can be cured by the peroxides of this invention usually consist of an unsaturated polyester and one or more polymerizable monomers. The unsaturated polyesters are, for instance, polyesters as they are obtained by esterifying at least one ethylenically unsaturated di- or polycarboxylic acid, anhydride or acid halide, such as maleic acid, fumaric acid, glutaconic acid, itaconic acid, mesaconic acid, citraconic acid, allylmalonic acid, allysuccinic acid, tetrahydrophthalic acid and others with saturated or unsaturated di- or polyols, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-pro-panediols, 1,2-, 1,3- and 1,4-butanediols, 2,2-dimethyl-1,3-propanediol, 2-hydroxymethyl-2-methyl-1,3-propanediol, 2-buten-1,4-diol, 2-butyn-1,4-diol, 2,2,4-trimethyl-1,3-~13~i60() pentanediol, glycerol, bisphenol A, mannitol and others.
Mixtures of such polyacids and/or mixtures of such poly-alcohols may also be used. The unsaturated di- or poly-carboxylic acids may be replaced, at least partly, by saturated polycarboxylic acids, such as adipic acid, succinic acid, sebacic acid and othersand/or by aromatic polycarboxylic acids, such as phthalic acid, trimellitic acid, pryomellic acid, isophthalic acid and terephthalic acid. The acids used may be substituted by groups such as halogen. Examples of such suitable halogenated acids are, for example, tetrachlorophthalic acid, 5,6-docarboxy-1,2,3,4,7,7-hexachlorobicyclo (2.2.1)-2-heptene and others.
The other component of the unsaturated polyester resin composition, the polymerizable monomer Or monomers, can be preferably ethylenically unsaturated monomers, such as styrene, chlorostyrene, vinyltoluene, divinylbezene, alphamethylstyrene, diallyl ~aleate, diallyl phthalate, dibutyl fumarate, acrylonitrile, triallyl phosphate, triallyl cyanurate,methyl acrylate, methyl methacrylate, _-butyl methacrylate, ethyl acrylate and others, or mixtures thereof, which are copolymerizable with said polyesters. A preferred resin composition contains as the polyester component the esterification product of 1,2-propylene glycol ~a polyalcohol), maleic anhydride (an anhydride of an unsaturated polycarboxylic acid) and phthalic anhydride (an anhydride of an aromatic dicarboxylic acid) as well as the monomer component, 113~600 styrene. Temperatures of about 10C to 200C and peroxide levels o~ about 0.05% to 5% or more by weight of curable unsaturated polyester resin are normally employed. The unsaturated polyesters described above can be filled with various materials such as sulfur, glass fibers, carbon blacks, silicas, metal silicates, clays, metal carbonates, antioxidants, heat and light stabilizers, sensitizers, dyes, pigments, accelerators, metal oxides, such as zinc oxide, blowing agents, etc.
In addition, the free-flowing solid peroxide compositions of this invention can be employed for vulcanizing natural ~ and synthetic rubbers, for curing of olefin copolymers and terpoly~ers, such as EPR (ethylene-propylene co-polymers~ and EPD~ (ethylene-propylene-diene terpolymer), for crosslinking of PE (polythylene), ethylene-vinyl acetate copolymers, silicon rubbers, styrene-butadiene rubbers and the like, in the presence or absence of additives and fill-ers such as sulfur, carbon blacks, silicas, clays, carbo-nates, antioxidants, heat and light stabilizers, sensiti-zers, dyes, accelerators, zinc oxide, oils, blowing agents, etc.
The invention peroxide compositions can additionally be employed for the curing of monomers such as diethylene glycol bis(allyl carbonate) (ADC) as well as other diallyl and polyally~l compounds. In these applications 0.1 to ~13~60~
10% or more of the invention composition, based on curable monomer, can be employed.
Other types of unsaturated resins can be cured using the compositions of this invention as curing catalysts. These resins, called unsaturated vinyl ester resins, consist of a vinyI ester resin component and one or more polymeri-zable monomer components. The vinyl ester resin component can be made by reacting a chloroepoxide such as epichloro-hydrin with appropriate amounts of a glycol such as lo bisphenol A ~2,2-di-(4-hydroxyphenyl)propane~, in the presence of a base such as sodium hydroxide, to yield a condensation product having terminal epoxy groups derived from epichlorohydrin. Subsequent reaction of the condensation product with polymerizable unsaturated carboxylic acids such as acrylic acid and methacrylic acid, in the presence or absence of acidic or basic catalysts, results in formation of a vinyl ester terminated resin component. Normally styrene is added as the poly-merizable monomer component to complete the preparation of the unsaturated vinyl ester resin. Temperatures of about 10C to 20GC and pure peroxide levels of about 0.05%
to 5% or more by weight of curable unsaturated vinyl ester resin compositions are normally employed for curing of the unsaturated vinyl ester resins. The unsaturated resin described above can be filled with the materials employed with the unsaturated polyester resin compositions described previously.
1~3~00 Description of Preferred Embodiments Example I Preparation of a 50% Dibenzoyl Peroxide/50%
Benzoic Acid Composition A reactor equipped with a high speed stirrer was charged with 200g of water and 80g of commercial, wet 78%
dibenzoyl peroxide and the mixture was stirred vigorously for an hour at 50C. The fine wet dibenzoyl peroxide was separated by filtration and was hand mixed with 50g of finely ground 20 mesh (0.85mm) benzoic acid and the lo resulting mixture was passed through a 50 mesh (0.30mm) screen. Obtàined was 116g of wet product. At 26 C
lOOg of the product was dried for 24 hours to yield 82g of free-flowing powder which had an assay of 50.5%
dibenzoyl peroxide. Preliminary burning tests were carried out on 5g samples of this product as well as on a commercial sample of 50% dibenzoyl peroxide/50% dicyclohexyl phthalate (DCHP). The results showed that the invention 50% dibenzoyl peroxide/50% benzoic acid composition was significantly more resistant to ignition than was the art 50% dibenzoyl peroxide/50% dicyclohexyl phthalate composi-tion.
113660~
Example II Preparation of 70% Dibenzoyl Peroxide/30%
Benzoic Acid Compositions A reactor equipped with a mechanical stirrer was charged with 310g of commercial wet 78% dibenzoyl peroxide,1500g of water, 104g (o.85 mole) Or granular benzoic acid and 72g (0.90 mole) of 50% aqueous NaOH solution at room temperature. The resulting slurry was acidiried by adding 63g (0.45 mole) of 70% sulfuric acid at room temperature. This resulted in precipitation of the ben-zoic acid onto the wet dibenzoyl peroxide. The resultlng wet composition was separated by filtration and was washed with water. The product was then dried at 26C for 24 hours to yield 330g of dry composition which contained 70.1% dibenzoyl peroxide.
Another sample of 70% dibenzoyl peroxide/30% benzoic acidwas prepared as above except that in this case solid sodium benzoate was added to the aqueous dibenzoyl peroxide slurry in place of the combination of benzoic acid and 50% aqueous NaOH solution. The resulting dry composition contained 70.4% by weight of dibenzoyl peroxide.
Preliminary burning tests were carried out on the two above samples of the 70% dibenzoyl peroxide/30% benzoic acid composition and on a commercial sample of a 70% dibenzoyl ~3~i6Q~
peroxide/30% dicyclohexyl phthalate composition. The results showed than our invention compositions, containing benzoic acid, exhibited delayed ignition and resistanee to burning; whereas, the art composition, containing dicyclohexyl phthalate, ignited immediately upon contact with a flame.
1~36i60(~
Example III Preparation of Other Dibenzoyl Peroxide/
Benzoic Acid Compositions Employing the acid precipitation processes described in Example II, several other dry free-flowing dibenzoyl peroxide/benzoic acid compositions were prepared which contained 30 to 85% dibenzoyl peroxide and 15 to 70%
benzoic acid. The burning characteristics of these invention compositions along with those for 98% dibenzoyl peroxide and for the 50% dibenzoyl peroxide/50% DCHP
lo and the 70% dibenzoyl peroxide/30% DCHP art compositions are summarized in Example III Table.
The burning tests were carried out on 5 gram samples of various dibenzoyl peroxide compositions. In the test a 5 gram sample was placed in an aluminum dish (40 mm in diameter and 12 mm high) and the flame from a gas jet was brought into contact with the composition. The ignition time (the time required for the sample to ignite after contact with the flame), the total burning test time (ig-nition time plus the burning time) and the flame height were noted.
113~60C~
Example III Table Burning Test Results (5 gram samples) Composition Compo- Ignit. Total Flame sition Dibenzoyl % Benzoic Assay, Time, Burn, Height Peroxide Acid % Secs. Secs. Ins.
85.5~1 8 54 80.7<1 10 48 74.71 32 48 70.52 40 48 65.82 108 42 60.73 133 36 55.24 140 36 50.618192 30 45.435185 24 40.348230 12 35.158317 12 30.360320 12 70% Dibenzoyl Peroxide/30% DCHP70.2 <1 21 48 50% Dibenzoyl Peroxide/50% DCHP51.3 ~1 ~300 30 98% Dibenzoyl Peroxide 99.1Cl <1 60 '' ' , The results in Example III Table show that almost all of the dibenzoyl peroxide/benzoic acid compositions exhibited delayed ignition whereas the art dibenzoyl peroxide compositions were considerably more hazardous since they ignited immediately.
113~600 Example IV: Preparation of a 50% Dibenzoyl Peroxide/
49.5% Benzoic Acid/0.5% Mineral Oil Composition To a reactor equipped with a mechanical stirrer was charged 207g of water, 76.9g. of commercial 78% wet dibenzoyl peroxide, 0.4g of a surfactant*, 59.4g of 20 mesh (o.85 mm) benzoic acid and an aqueous 10% mineral oil (MO) emulsion that was previously made by mixing 0.6g of MO with 0.2g of a surfactant* and 5.2g of water. The resulting mixture was stirred for 15 minutes at 12 to 15 C, lo then the product was separated by filtration and the product was washed with water. The product was then spread out in a tray and was allowed to air dry at 20-25C over a period of 24 hours. Obtained was 117g of the dry formu-lation, 50% dibenzoyl peroxide/49.5% benzoic acid/0.5% MO.
The assay of the product according to the "active oxygen"
content was 50.1%. The MO reduced the amount of dusting due to the presence of fine particles of dibenzoyl peroxide and benzoic acid that were in the formulation.
*The surfactant employed was prepared by adding 75g of a stripped coconut fatty acid mixture (e.g., Ashland's HYDROFOL(R)ACID 631) to 711g of aqueous 7.4% posassium hydroxide solution. The mixture was stirred at room temperature until a clear aqueous solution was obtained.
113~i600 A shaker vibration test was carried out on the composition that was produced. A 250 ml graduated cylinder was completely filled with the 50% dibenzoyl peroxide/49.5%
benzoic acid/0.5% MO formulation. The top of the cylinder was covered with polyethylene film in order to prevent loss of product during shaking and the filled graduated cylinder was taped vertically to a Tyler Sieve Shaker (Model RX~24, W. C. Tyler, Inc., Mentor, Ohio 44060) and the shaker was turned on. After various periods of shaking the material in the top and in the bottom of the cylinder was assayed for dibenzoyl peroxide content.
Example IV Table summarizes the results and shows that the original assay, and the top and bottom assays were Example IV Table Shaker Test Results - Assay Uniformities Dibenzoyl Peroxide Content, %
Shaking Time, hrs. Ori~inal Top Bottom 1.0 50.1 50.4 49.8 3.0 50.0 49.7 50.0 6.o 50.0 49.2 50.9 10.0 50.1 52.2 51.9 within analytical error of each other. Hence, the 50%
dibenzoyl peroxide/49.5% benzoic acid/0.5% MO formulation remained stable with respect to assay uniformity during at least 10 hours of shaking on a Tyler Sieve Shaker.
.:
113~
- 2~ -Example V: Pre~aration of an 85% Dibenzoyl Peroxide/14.5%
Benzoic Acid/0.5% MO Composition To a reactor equipped with a mechanical stirrer was charged 280g of water, lO9g of commercial 78% wet dibenzoyl per-oxide, 0.2g of a surfactant (described in Example IV), 14.5g of 20 mesh (0.85 mm) benzoic acid and 6g of an aqueous 10% MO emulsion (described in Example IV). The resulting mixture was stirred for 15 minutes at 12-15C, then the product was separated by filtration and the product was washed with water. The product was then spread out on a tray and was allowed to dry at 20-25C over a period of 24 hours. A white free-flowing powder was obtained which contained 85% dibenzoyl peroxide, 14.5% benzoic acid and 0.5% MO. The assay of the product according to "active oxygen" content was 85.3%.
113~600 Example VI: SPI Exotherms of Various Dibenzoyl Peroxide/
Benzoic Acid Co~positions Two unsaturated polyester resin compositions were employed in this example.
Resin Composition A
This unsaturated polyester resin was composed of an unsaturated polyester and styrene monomer. The unsaturated polyester was an alkyd resin made by esterfying the following components.
lo Component Quantity Maleic anhydride l.0 mole Phthalic anyhydride l.0 mole Propylene glycol 2.2 moles To the resulting resin was added 0.013% by weight of hydroquinone inhibitor. The alkyd resin had an Acid No.
of 45-50. Seven (7) parts by weight of the above polyester (alkyd resin) was diluted with three (3) parts by weight ~f monomeric styrene. The resulting unsaturated polyester resin had the following properties:
a. Viscosity (Brookfield No. 2 at 20 r.p.m.) 13.08 poise b. Specific gravity 1.14 1136~i00 Curing Procedure Gelation and cure characteristics of various initiators in the above unsaturated polyester resin were determined using the Standard SPI Exotherm Procedure ("SPI Procedure for Running Exotherm Curves-Polyester Resins"j published in the Preprint of the 16th Annual Conference - Reinforced Plastics Division, Society of the Plastics Industry, Inc., February, 1961).
Using the curing procedure described above at 93C (200F) the 50% dibenzoyl peroxide/49.5% benzoic acid/0.5% MO (A) composition of Example IV, the 85% dibenzoyl peroxide/14.5%
benzoic acid/0.5% MO (B) composition of Example V, commer-cial wet 78~ dibenzoyl peroxide and commercial 50~ dibenzoyl peroxide/50% dicyclohexyl phthalate (C) were evaluated as curing agents for Resin Composition A. The results are summarized in Example VI Table I and show that the instant invention compositions (A) and (B) cured the unsaturated polyester resin and had activities that were essentially the same as those of art composition (C) and commercial wet 78% dibenzoyl peroxide in Resin Composition A.
93C SPI Exotherm Data - Resin Composition A
Dibenzoyl Peroxide Peak Barcol Composition Level* ~ Gel,Mins. Cure,Mins. Exo.,F Hardness A 1.0 2.6 3.7 411 45 B 1.0 2.2 3.1 403 45 C 1.0 2.3 3.5 415 45 78~ Dibenzoyl Peroxide 1.0 2.4 3.6 413 45 *As pure dibenzoyl peroxide 113~i~00 Resin Composition B (DERAKANE 411-45) This unsaturated polyester resin was a corrosion resistant unsaturated polyester resin that was composed of a vinyl ester resin and styrene monomer. This resin, DERAKANE
411-45, was produced by the Dow Chemical Company. (see Dow Chemical Company Bulletin,"Derakane Vinyl Ester Resins for Corrosion Resistance", 1975).
The same curing procedure and the same dibenzoyl peroxide compositions as used for curing of Resin Composition A
lo were used ~or curing of Resin Composition B. The results are summarized in Example VI Table II and again show that the dibenzoyl peroxide compositions of the instant invention, e.g., (A) and (B), cured Resin Composition B and had activites that were essentially the same as those of art composition (C) and commercial wet 78% dibenzoyl peroxide, hence the aromatic carboxylic acid had no detrimental effect on the efficiency of the peroxide as a curing initiator ~or unsaturated polyester resins.
Example VI Table II
93C SPI Exotherm Data - Resin ComPosition B
Dibenzoyl Peroxide Le~el*,Gel, Cure, Peak Barcol Composi-tion % ~ins. Mins. Exo., F Hardness A 1.0 5.6 7.3 416 20-25 B 1.0 5.0 6.8 415 25-30 C 1.0 5.2 6.9 415 20-25 78% Dibenzoyl 1.0 5.5 7.3 416 20-25 Peroxide ~As pure dibenzoyl peroxide * ~ ,v~c~
, 113f~i6~0 Example VII: Ignition Times for Various Dibenzoyl Peroxide/Carboxylic Acid Formulations Several dry free-flowing dibenzoyl peroxide/carboxylic acid formulations were prepared by the procedures described in the previous Examples. Burning ignition times were then determined on these formulations.
The results are summarized in Example VII Table and Example VII Table Ignition Times of Various Dibenzoyl Peroxide/Carboxylic lo Acid Formulations Formulation Composition Filler Ignition Dibenzoyl m.p., Time, Peroxide, % Filler, % Cseconds 60% 2-Methylbenzoic Acid, 40% 103-5 28 60% 4-Methylbenzoic Acid, 40% 180-2 13 60% Benzoic Acid, 40% 122-3 3 70% Benzoic Acid, 30% 122-3 2 70% Stearic Acid, 30% 65-67~ 1 70% Azelaic Acid*, 30% 98-102C 1 70% DCHP, 30 63-5 ~1 ~ l,9-nonanedioic acid show that aromatic carboxylic acids such as benzoic acid, 2-methylbenzoic acid and 4-methylbenzoic acid caused the formulation to have desirable and safe delayed ~gnitions whereas the non-aromatic carboxylic acids such as stearic 1136~600 - 29 _ acid and azelaic acids failed to delay ignition of the compositions containing them. The results of this example demonstrate the general usefulness of aromabic carboxylic acids in the practice of this invention.
113~60V
Example VIII: Preparation of Peroxide/Benzoic Acid For-mulations Several room temperature stable solid dialkyl peroxydicar-bonates su~ as di-(2-phenoxyethyl) peroxydicarbonate (A-l) (m.p., 97-100C), di-(4-t-butylcyclohexyl) peroxydicarbonate (A-2)(m.p., 91-2C) and dibenzyl peroxydicarbonate (A-3) (m.p., 101-2C) and the solid dihydroperoxide, 2,5-dimethyl-2,5-dihydroperoxyhexane (A-4)(m.p., 104-5 C), in dry granular form were individually hand mixed with equal quantities of dry granular benzoic acid (m.p., 122-3 C) or dicyclohexyl phthalate (DCHP)(m.p., 65-5 C). The latter filler, DCHP, has been employed in prior art compositions whereas the former ~iller, benzoic acid, is employed in the compositions of this invention. Example VIII Table summarizes the burning ignition times for the above compositions and show that the 50% peroxide/50~ benzoic acid formulations of this invention resulted in much longer ignition times than the corresponding 50% peroxide/50% DCHP
formulations. Hence, the aromatic carboxylic acid fillers (e.g., benzoic acid) of the present invention are much safer fillers for peroxides than are prior art fillers (e.g., DCHP).
1~3~600 Example VIII Table lgnition Tlmes for Various 50% Peroxide/50% Filler Compositions Peroxide FillerIgnition Time, secs.
A-l Benzoic Acid 6 A-l DCHP 3 A-2 Benzoic Acid 8 A-3 Benzoic Acid 5 A-4 Benzoic Acid47 Dibenzoyl Peroxide Benzoic Acid18*
Dibenzoyl Peroxide DCHP C 1 *Data from Example III Table 113~600 Example IX: Preparation of a 70% Di-(2-methylbenzovl) Peroxide/30% Benzoic Acid Formulation Employing essentially the same procedure as used in Example V solid free-flowing 70~ di-(2-methylbenzoyl) peroxide formulations were prepared in which benzoic acid, an aromatic carboxylic acid filler of this invention, and DCHP, an art flller, were employed. Example IX Table shows that the composition containing benzoic acid gave a longer burning ignition time than did the composition locontaining the art filler (DCHP).
Example IX Table 70% Di-(2-methylbenzoyl) Peroxide Formulations Filler MeltingO Composition Filler Point, CBurning Ignition Time, secs.
Benzoic Acid 122-3 2 113~6(~0 Example X: Thermal Stabilities of Dibenzoyl Peroxide/
Benzoic Acid Formulations Several dibenzoyl peroxide/benzoic acid formulations of this invention and several dlbenzoyl peroxide/DCHP formulations of the art were stability tested at 50C, 60C and 70C.
Samples containing approximately lOg of each formulation were placed in ovens at 50C, 60C and 70C and the samples were held at these temperatures for various lengths of time. Example X Table summarizes the percent of assay lost for each of these formulations at the ends of the thermal stability tests. The results demonstrate that the dibenzoyl peroxide/benzoic acid formulations of this invention have significantly better thermal stabilities than the art dibenzoyl peroxide/DCHP formulations. The invention formulations lost very little assay when stored at 70C
whereas one of the art compositions decomposed completely at 70C and a second art composition decomposed violently at 70C. The practicaly implication of these thermal stability data is that the invention dibenzoyl peroxide formulations are safer to process, dry at elevated temperatures during manufacture, ship and store than are the prior art dibenzoyl peroxide/DCHP formulations.
1~3~i600 Example X Table Thermal Stabilities of Various Dibenzoyl Peroxide Formulations Formulation Composition Dibenzoyl Storage Duration % Assay Peroxide, % Filler Temp, C hrs. Lost Benzoic Acid, 50 50 240 0.4 DCHP, 50 50240 2.4 Benzoic Acid, 50 60 240 o.8 DCHP, 50 60240 100*
Benzoic Acid, 50 70 16 1.4 DCHP, 50 70 ~100**
Benzoic Acid, 30 50 120 0.1 DCHP, 30 50120 2.0 Benzoic Acid, 15 50 240 3-DCHP, 15 50240 12.9 Benzoic Acid, 15 60 240 8.4 DCHP, 15 60 48 19.1 D~HP, 15 60 120 100 Benzoic Acid, 15 70 6 0.5 DCHP, 15 70 2100***
* Sample decomposed completely and became liquid.
After 120 hrs./60C % assay lost was 18.4.
** Sample decomposed completely and became liquid.
***Sample exploded and destroyed testing oven after two hours at 70C.
1~35i601) Example XI: Vin~l Chloride Sus~ension Polymerization with a 50% Di-~2-phenoxyethyl) peroxydicarbonate/50% Benzoic Acid Com~osition Pure di-(2-phenoxyethyl) peroxydicarbonate (A-l) and the 50% A-1/50% benzoic acid composition of this inventi~n were evaluated as polymerization initiators at 55C for vinyl chloride suspension polymerizations in a PVC reactor.
The level of initiator that was employed on a pure basis was 0.10 parts per hundred based on vinyl chloride monomer and the pH of the suspensions was about 6.5. The experimental procedure employed is described below.
Suspension Polymerizations Polymerizations of vinyl chloride in suspension were carried out in a 1.5 liter reactor, which was designed and instrumented such ~hat the polymerization could be monitored calortmetrically. The reactor was immérsed in a water bath, maintained 0.5C above the desired reaction temperature, thus preventing any heat loss to the surroundings. The heat produced from the exothermic polymerization, plus the heat passed into the reactor from the water bath, was removed by the passage of cooling water thro gh internal coils in the reactor. Thus the temperature was kept constant. The flow rate of the coling water, and the temperature difference between entrance and exit streams were monitored, hence a continuous recording 1131~600 of heat removed (cal. min ) was obtained.
The pressure in the reactor was also continuously moni-tored. At about 70% conversion of monomer to polymer, the monomer in the vapor phase became depleted and the pressure fell. Thus, from a knowledge of the point of 70% conversion, and heat of polymerization of vinyl chloride (23 kcal/mole) it was possible to calculate the ~background count" in the calorimetric recording, this background being due to heat flow from the water bath to the reactor. By substrac~ion, the true rate of polymeri-- zation (cal. min 1), as a function of time, was obta~ned.
Suspension System Used pH~6.5) 1% solution of Aerosol MA 80%* 42 ml 1% solution of Methocel F 50** 168 ml Triply distilled water ~ 469 ml * Surfactant made by American Cyanamid Co. (sodium dihexyl succinate)Cr~
**Hydroxypropyl methyl cellulose polymer made by Dow Chemical C\~_~L~W~_~) Note: pH of the aqueous phase was measured at ambient temperatures, 22C, using a standard pH meter.
- ~7 -Example ~I Table sUmmarizes the time that was required for reachin~ the pressure drop (ca, 70% conversion of vinyl chloride monomer to pol~mer) when pure A-l and the 50% A-1/50% benzoic acid composition were employed.
Example XI Table Viny~l Chloride Suspension Polymerizations at 55C, pH 6.5 Level, Time to Pressure Drop Initiator Compos~tion phm* (~70% Conversion),Mins.
Pure A-l 0.10 340 50% A-1/50% Benzoic Acid 0.10 340 *Parts of pure peroxide per hundred monomer The results show that the 50% A-1/50% benzoic acid composition of this invention had the same efficien~y (on a pure basis) as pure A-l. Hence, the safe composition of this invention, such as 50% A-1/50% benzoic acid, can be employed as free-radical initiator compositions for polymerizing monomers, such as vinyl chloride, to polymers, hence the aromatic carboxylic acid had no detrimental effect on the efficiency of the peroxide as an initiator for vinyl monomer polymerizations.
11366~
EXAMPLE XII~: Curing of Dlethylene ~lycol Bis~allyl Carbonate~ w~th 8'5% Dlbenzoyl Peroxide/15% Benzoic Acid, 85%' D1'benzoy1 Peroxide/15% Dicyclohexyl Phthalate and 98% Di'be'nzo'y~l Peroxi'de Compositions Diethylene glycol bis(allyl carbonate), ADC,is a cross-linkable monomer, which then cured with free-radical curing agents, is finding increasing use in optical applications (safety glasses, safety shields, etc.) The only free-radical catalysts that have been found to satisfactorily cure ADC are dry 98% dibenzoyl peroxide and the low molecular weight peroxydicarbonates, diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate.
The latter initiators require refrigerated storage and care in handling whereas the former 98% dibenzoyl peroxide, although stable, requires extremely careful handling owing ~o its explosive burning hazard. Although commercial wet dibenzoyl peroxide formulations containing 22 to 33% water are resistant to burning the water in them causes problems such as gas bubbles and surface imper-fections when these wet dibenzoyl peroxide products are used for curing of ADC lenses.
~13ti6(~0 Various dry dibenzoyl peroxide compositions were employed for curing ADC. These c~mpositions were an instant invention compos~tion consisting of 85% dibenzoyl peroxide and 15% benzoic acid and art compositions such as dry 98% dibenzoyl peroxide and an 85% dibenzoyl peroxide/dicyclohexyl phthalate formulation.
Curing ~rocedure ~n the curing tests 0.125 inch thick lenses were cast in a curing cell consisting of two glass plates separated by~ a T~gon (trademark of the Norton Co., a clear, flexible vinyl acetate/vinyl chloride copolymer) gasket.
The glass plates were held in contact with the Tygon(R) gasket by means of four spring binder clips, one on each edge of the 4 inch x 4 inch cell. The catalyzed ADC
monomer was prepared by dissolving 1.772gof dibenzoyl peroxide (on a pure basis) in 50g of ADC. The catalyzed ADC was in~ected into the cell by means of a syringe. A
second syringe was used to allow the displaced air to escape.
The castings were polymerized in a hot air oven using the following time/temperature profile:
113~;6~0 _ 40 -Temperature (C~ Time, mins.
o 96 15 Thus, the total cure time was 6~2 hours. At the end of this period the cells were removed from the oven and allowed to cool to ambient temperature. The Barcol hardness and appearance of each casting were then deter-mined. Example XII Table summarizes the result of curing of ADC by the dibenzoyl peroxide compositions.
113f~6C~
Example XlI Table Curing of ADC with Dibenzoyl Peroxide Compositions (I.772g pure Dibenzoyl Peroxide/50g ADC) Dibénzoyl Peroxide Composition Hardness Appearance Dry 98% Dibenzoyl Peroxide 45-48 Good 85% Dibenzoyl Peroxide/15% 41-45 Good Benzoic Acid 85% Dibenzoyl Peroxide/15% 17-23 Poor*
Dicyclohexyl Phthalate lo *Uneven surface due to premature release from the glass surface of the mold.
The instant invention composition (85% dibenzoyl peroxide/
15% benzoic acid) cured the resin about as well as did dry 98% dibenzoyl peroxide. On the other hand the art composition, 85% dibenzoyl peroxide/15% dicyclohexyl phthalate, gave a poor quality lens as judged by hardness and surface quality. These results demonstrate that the safe dibenzoyl peroxide/benzoic acid compositions of this invention can be used for curing of ADC in place of hazardous dry 98% dibenzoyl peroxide whereas the art dibenzoyl peroxide/dicyclohexyl phthalate formulations cannot be used. Since dry 98% dibenzoyl peroxide is forbidden in transport in most of the countries of the world, the above results represent a significant advance in the art. They demonstrate that producers of ADC
lenses throughout the world can safely use the safe and stable dibenzoyl peroxide/benzoic acid compositions of 113~1600 this inventiGn in place of the hazardous dry 98%
dibenzoy~l peroxide and the hazardous and the thermally unstable low molecular weight liquid peroxydicarbonates for curing o~ ADC.
11366al0 Example XI~I: 50% Dialkyl Peroxide/50% Filler For~ulation~s Two dialky~l peroxides and two fillers were used to prepare four 50% dialkyl peroxide/50% filler compositions.
The dialkyl peroxides used were di-cumyl peroxide (A-5) (m.p., 39 C) and 1,3-di-[1-methyl-1-(t-butylperoxy)ethyl]-benzene (A-6) (m.p., 70 C) whereas~ the fillers were benzoic acid (m.p., 122-3 C) and dicyclohexyl phthalate (DCHP) (m.p., 63-5 C). The latter filler, DCHP, has been employed in prior art compositions whereas the former filler, benzoic acid, is employed in the compositions of this invention. The compositions were prepared by handmixing of equal parts of powdered dialkyl peroxide and powdered filler untll the compositions were uniform. The resulting 50% peroxide/50% filler compositions as well as pure A-5 and pure A-6 were evaluated in burning tests on 5 gram portions of each sample. The maximum flame heights of each composition were noted and the results are summarized in Example XIII Table.
1136~(~0 Example XIII Table Burning Tests on 50% Dialkyl Peroxide/50% Filler Compositions Dialkyl Maximum Peroxide, % Flame Height, ins.
A-5, 50 Benzoic Acid, 50 10 - 12 A-5, 5 DCHP, 50 24 A-5, 100 None 36 - 48 A-6, 50 Benzoic Acid, 50 14 - 16 lo A-6, 50 DCHP, 50 28 - 30 3 A-6, 100 None 36 The results show that both fillers (benzoic acid and DCHP) reduced the flame height of the peroxide burn, hence, both fillers reduced the explosive burning hazard of pure A-5 and A-6. However, the compositions of this invention (i.e., 50% A-5/50% benzoic acid and 50% A-6/50% benzoic acid) were significantly more effective in reducing the flame height and explosive burning hazard than were the compositions which used the art filler (i.e., 50%
A-5/50% DCHP and 50% A-6/50% DCHP).
Claims (9)
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED
AS FOLLOWS:
1. A solid, dry, free-flowing peroxide/unsubstituted or alkyl substituted benzoic acid composition consisting essentially of:
40 to 85% by weight of a solid peroxide having a melting point above 30°C and selected from the group consisting of substituted or unsubstituted diacyl peroxides, dialkyl peroxydicarbonates, ketone peroxides, dialkyl peroxides, peroxyesters, and alkyl hydroperoxides, 15 to 60% by weight of a solid unsubstituted or substituted benzoic acid wherein the substituent is an alkyl of 1 to 4 carbons, and 0.0 to 2.0% by weight of a dust suppressant.
40 to 85% by weight of a solid peroxide having a melting point above 30°C and selected from the group consisting of substituted or unsubstituted diacyl peroxides, dialkyl peroxydicarbonates, ketone peroxides, dialkyl peroxides, peroxyesters, and alkyl hydroperoxides, 15 to 60% by weight of a solid unsubstituted or substituted benzoic acid wherein the substituent is an alkyl of 1 to 4 carbons, and 0.0 to 2.0% by weight of a dust suppressant.
2. The solid peroxide composition of Claim 1 wherein the solid peroxide is selected from the group consisting of dibenzoyl peroxide, di-(2-methylbenzoyl) peroxide, di-(2-phenoxyethyl) peroxydicarbonate, di-(4-t-butylcyclohexyl) peroxydicarbonate, dibenzyl peroxydicarbonate, 2,5-dimethyl-2,5-dihydroperoxyhexane, di-cumyl peroxide, and
3. The solid peroxide composition of Claim 2 wherein the solid unsubstituted or substituted benzoic acid is selected from the group consisting of benzoic acid, 2-methylbenzoic acid, and 4-methylbenzoic acid.
4. The solid peroxide composition of Claim 1 wherein the dust suppressant is 0.5% mineral oil.
5. The solid peroxide composition of Claim 1 of 85% of dibenzoyl peroxide and 15% of benzoic acid.
6. The solid peroxide composition of Claim 1 of 50% of dibenzoyl peroxide, 49.5% of benzoic acid, and 0.5% of mineral oil.
7. In the method of crosslinking an unsaturated polyester resin, the improvement comprising crosslinking in the presence of an initiating amount of a solid, dry, free-flowing peroxide/unsubstituted or alkyl substituted benzoic acid composition consisting essentially of:
40 to 85% by weight of a solid, organic peroxide having a melting point above 30°C.
15 to 60% by weight of a solid unsubstituted or alkyl substituted benzoic acid having a melting point above 40°C
and 0.0 to 2.0% by weight of a dust suppressant.
40 to 85% by weight of a solid, organic peroxide having a melting point above 30°C.
15 to 60% by weight of a solid unsubstituted or alkyl substituted benzoic acid having a melting point above 40°C
and 0.0 to 2.0% by weight of a dust suppressant.
8. In the method of crosslinking diethylene glycol bis(allyl carbonate) monomer, the improvement comprising crosslinking in the presence of an initiating amount of a solid, dry, free-flowing peroxide/unsubstituted or alkyl substituted benzoic acid composition consisting essentially of:
40 to 85% by weight of a solid, organic peroxide having a melting point above 30°C, 15 to 60% by weight of a solid unsubstituted or alkyl substituted benzoic acid having a melting point above 40°C
and 0.0 to 2.0% by weight of a dust suppressant.
40 to 85% by weight of a solid, organic peroxide having a melting point above 30°C, 15 to 60% by weight of a solid unsubstituted or alkyl substituted benzoic acid having a melting point above 40°C
and 0.0 to 2.0% by weight of a dust suppressant.
9. In the method of polymerizing ethylenically unsaturated monomers, the improvement comprising polymerizing in the presence of an initiating amount of a solid, dry, free-flowing peroxide/unsubstituted or alkyl substituted benzoic acid composition consisting essentially of:
40 to 85% by weight of a solid, organic peroxide having a melting point above 30°C, 15 to 60% by weight of a solid unsubstituted or alkyl substituted benzoic acid having a melting point above 40°C
and 0.0 to 2.0% by weight of a dust suppressant.
40 to 85% by weight of a solid, organic peroxide having a melting point above 30°C, 15 to 60% by weight of a solid unsubstituted or alkyl substituted benzoic acid having a melting point above 40°C
and 0.0 to 2.0% by weight of a dust suppressant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/308,220 US4387044A (en) | 1979-08-13 | 1981-10-05 | Safe, dry, free-flowing solid peroxide/unsubstituted or alkyl substituted benzoic acid compositions |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US6615079A | 1979-08-13 | 1979-08-13 | |
| US066,150 | 1979-08-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1136600A true CA1136600A (en) | 1982-11-30 |
Family
ID=22067565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000355772A Expired CA1136600A (en) | 1979-08-13 | 1980-07-09 | Safe, dry, free-flowing peroxide/aromatic carboxylic acid compositions |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS5636502A (en) |
| BR (1) | BR8005067A (en) |
| CA (1) | CA1136600A (en) |
| DE (1) | DE3030658A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10875982B2 (en) | 2015-11-23 | 2020-12-29 | United Initiators Gmbh | BCHPC having a reduced burning rate |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH078898B2 (en) * | 1987-05-28 | 1995-02-01 | 帝人株式会社 | Thermosetting epoxy resin composition for molding |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2453070A (en) * | 1944-08-23 | 1948-11-02 | Buffalo Electrochemical Compan | Organic peroxide composition |
| US2453071A (en) * | 1945-01-27 | 1948-11-02 | Buffalo Electro Chem Co | Desensitization of solid organic peroxides |
| DE1048028B (en) * | 1956-09-05 | 1958-12-31 | Elektrochem Werke Muenchen Ag | Polymerization catalyst in solution for the production of polymers and copolymers from unsaturated organic compounds |
| NL132378C (en) * | 1966-06-23 | |||
| DE1922171C3 (en) * | 1969-04-30 | 1979-03-01 | Peroxid-Chemie Gmbh, 8021 Hoellriegelskreuth | Process for the production of a peroxide paste |
-
1980
- 1980-07-09 CA CA000355772A patent/CA1136600A/en not_active Expired
- 1980-08-12 BR BR8005067A patent/BR8005067A/en unknown
- 1980-08-12 JP JP10991380A patent/JPS5636502A/en active Pending
- 1980-08-13 DE DE19803030658 patent/DE3030658A1/en not_active Ceased
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10875982B2 (en) | 2015-11-23 | 2020-12-29 | United Initiators Gmbh | BCHPC having a reduced burning rate |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3030658A1 (en) | 1981-03-26 |
| BR8005067A (en) | 1981-05-12 |
| JPS5636502A (en) | 1981-04-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |