CA1216390A - Ethylenically unsaturated polymerizable compositions - Google Patents
Ethylenically unsaturated polymerizable compositionsInfo
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- CA1216390A CA1216390A CA000443967A CA443967A CA1216390A CA 1216390 A CA1216390 A CA 1216390A CA 000443967 A CA000443967 A CA 000443967A CA 443967 A CA443967 A CA 443967A CA 1216390 A CA1216390 A CA 1216390A
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- prepolymerizate
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Abstract
ABSTRACT OF THE DISCLOSURE
There is disclosed a process for the polymerization of a non-air-curing mono-ethylenically unsaturated free-radical polymerizable monomer in which an oxidative prepolymerizate is incorporated into the monomer. The prepolymerizate is an oxidatively polymerizable compound in which there are at least two unsaturations which are each .beta.,.gamma. to oxygen or sulfur which is employed in an amount of 1 - 200 parts by weight of the prepolymerizate per mole of non-air-curing monomer, and is of the formula where R1 is a radical characterized by a molecular weight less than about 2000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the functionality of R1 is n, and is in the range of 1 to 10, where R2 is selected from the group consisting of hydrogen and C1 to C10 organic radicals, where E is a moiety containing a radical having an activated olefinic unsaturation .beta.,.gamma. to the activating group and is present in sufficient amount to provide a .beta.,.gamma.
-unsaturation equivalent of less than about 250, where m is the average number of E moieties in the n segments of the structure and where the product of m and n is in the range of about 4 to about 60. Compositions are also disclosed of the oxidative prepolymerizate described above together with the polymerizable monomer. The resulting products formed after polymerization have a wide field of utility in adhesives, moldings, casting operations and the like. With the present development, since the oxidative prepolymerizate and the monomer copolymerize, varying of the properties of the final product can be readily achieved.
There is disclosed a process for the polymerization of a non-air-curing mono-ethylenically unsaturated free-radical polymerizable monomer in which an oxidative prepolymerizate is incorporated into the monomer. The prepolymerizate is an oxidatively polymerizable compound in which there are at least two unsaturations which are each .beta.,.gamma. to oxygen or sulfur which is employed in an amount of 1 - 200 parts by weight of the prepolymerizate per mole of non-air-curing monomer, and is of the formula where R1 is a radical characterized by a molecular weight less than about 2000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the functionality of R1 is n, and is in the range of 1 to 10, where R2 is selected from the group consisting of hydrogen and C1 to C10 organic radicals, where E is a moiety containing a radical having an activated olefinic unsaturation .beta.,.gamma. to the activating group and is present in sufficient amount to provide a .beta.,.gamma.
-unsaturation equivalent of less than about 250, where m is the average number of E moieties in the n segments of the structure and where the product of m and n is in the range of about 4 to about 60. Compositions are also disclosed of the oxidative prepolymerizate described above together with the polymerizable monomer. The resulting products formed after polymerization have a wide field of utility in adhesives, moldings, casting operations and the like. With the present development, since the oxidative prepolymerizate and the monomer copolymerize, varying of the properties of the final product can be readily achieved.
Description
S3~1 -1- 06-12~1099)A
ETHYLENICALLY UNSATURATED POLYMERIZABLE COMPOSITIONS
_ This invention relates to a free-radical-polymerizable composition and to a polymerization process and more specifically to a free-radical-poly-merizable composition containing a polymerizable initiator and to a process for initiating the poly-merization of free-radical-polymerizable monomers with a polymerizable initiator.
Thus the invention relates to compositions containing a polymerizable initiator that not only initiates polymerization reactions but also apparently enters into the polymerization reactions and modifies the properties of final polymers obtained.
DESCRIPTION OF THE PRIOR ART
_ Typically a free radical polymerization initiator is a peroxide, a peracid, a perester or an azo derivative that is capable of generating free radicals which initiate polymerization of ethyleni-cally unsaturated monomers. The molecule does not take part in the polymerization to the extent of becoming incorporated into the polymer molecule as a comonomer.
These initiators are highly active and sometimes dangerously unstable and need to be handled with great care. For this reason they are used under carefully controlled conditions.
One constraint on conventiQnal free-radical-initiation is that it is usually strongly inhibited by the presence of oxygen such that polymerization reactions have to be conducted in an inert atmosphPre.
"~
~6~
Conventional initiators have an activation temperature below which they are not very active so that free-radical polymerization reacti.ons are conventionally carried out at elevated temperatures. Since such reactions are usually also exothermix it is necessary to equip polymerization vessels with elaborate temperature control facilities, The initiators used in the present invention however are not only highly stable and highly reactive but they have the capacity actually to enter into a copolymerization reaction with the ethylenically-unsaturated, free radical-polymerizable monomer and so produce copolymers that can be tailored to the desired end use. In addition the initiators are very active even at room temperature so that the reaction mixture need not be heated.
A further advantage is that, unlike conventional initiators, they function as oxygen scavengers and so work effectively in the presence of oxygen. Elaborate closed reaction vessels are not therefore required.
It is recognized that often it is advantageous to operate in the absence of air so as to reduce color body formation and to maximise structurai uniformity. The initiators of the invention are even more effective in the absence of air and permit ready access to these same advantages.
DESCRIPTION OF THE INVE~TIO~
The present invention provides a process for the polym2rization o~ a non-air-curable mono-ethylenically-unsaturated, free-radical-polymerizable monomer which comprises:
A process for the polymerization of a non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer which comprises:
A. Incorporating in the monomer an oxidative prepolymerizate of an oxidatively polymerizable compound having a structure comprising at least two unsaturations which are .j ~^ . ;.
6~
-2a-each ~ ,y to oxygen or sulfur activating the unsaturations towards oxidative polymerization, to provide a concentration of from about l to abou-t 200 parts by weight of oxidative prepolymerizate per mole of non-air-curing monomer, the oxidatively polymerizable compound being represented by the structure:
l ~ )m R2~ n where Rl is a radical characterized by a molecular weight less than about 2000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the functionality of Rl is n, and is in the range of l to lO, where R2 is selected from the group consisting of hydrogen and Cl and C10 organic radicals, where E
is a moiety containing a radical having an activated olefinic unsaturation ~ ,y to the activating group and is present in sufficient amount to provide a ~ ,y -unsaturation equivalent of less than about 250, where m is the average number of E
moieties in the n segments of the structure and where the product of m and n is in the range of about 4 to about 60; and in which the non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer is a (meth)-acrylic ester containing from 4 to 14 carbon atoms; and s. activating the oxidative prepolymerizate to copolymerize with the non-air-curing monomer.
There is also provided, in a further embodiment to this invention, a process for the polymerization of a non-air-curing mono-ethylenically-unsaturated free-radical-polymerizable monomer which comprises:
A. forming an oxidative prepolymerizate by bringing into contact with air the reaction product of an alcohol and allyl glycidyl ether comprising at least four (4) 63~
-2b-allyloxy groups per hydroxy group of the alcohol.
B. adding the non-air-curing free-radical-polymerizable monomer to the oxidative prepolymerizate to provide a concentration of oxidative prepolymerizate of 10 to 50 parts by weight per mole of non-air-curing monomer; and S C. activating the oxidative prepolymerizate toward free-radical copolymerization with the non-air-curing free-radical polymerizable monomer by means of a cobalt drier salt.
There is also provided, in accordance with this invention, a composition comprising:
A. an oxidative prepolymerizate of an oxidatively polymerizable compound having a structure comprising at least two unsaturations which are each ~ , ~ to oxygen or sulfur activating the unsaturations towards oxidative polymerization, the oxidatively polymerizahle compound being represented by the structure:
Rl~ (E)m ~ R2] n where R1 is characterized as being a radical of molecular weight less than about 2,000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the tunctionality of R1 is n and is in the range of 1 to 10, where R2 is selected from the group consisting of hydrogen and C1 ~o C 10 organic radicals, where E is a moiety containing a radical having an activated olefinic unsaturation ~ , y to the activating group and is ~ .,J~
~L2:~L63~
present in sufficient amount to provide a ~ unsaturation equivalent of less than about 250, where m is the average number of E moieties in the n segments of the s-tructure and where the product m and n is in the range of about ~ to about 60;
B. a non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer; wherein the concentration of oxidative prepolymerizate is in the range of about 1 to about 200 parts by weight per mole of non-air-curing monomer;
and wherein the non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer is a (meth)-acrylic ester containing from 4 to 14 carbon atoms.
In still further embodiments, there is also provided a copolymer product obtained by carrying out the above described process.
OXIDATIVELY POLYMERIZABLE COMPOUND
The process of oxidative polymerization is most widely known in the context of drying oils and alkyd based paints, (which are generally long chain unsaturated acid triglycerides), and relates to a mechanism by which, in contact with air, certain molecules can cross-link. This occurs through initial formation of peroxide group intermediates which then decompose to form cross-link sites between the molecules.
Readiness to undergo oxidative polymerization is also demonstrated by the prepolymers described in USP 4,145,248 which are further described below and which provide some of the preferred oxidative prepolymerizates used in the process of the invention.
An oxidative prepolymerizate of an oxid-~Z~i3~
-4- 06-12(1099)A
tively polymerizable compound (monomer or prepolymer as indicated above) is obtained by a process in which oxygen is bubbled through the compound, (if a liquid), or its solution at a temperature that is preferably below 30C. This is continued until a significant proportion of hydroperoxide groups has been generated.
The presence of hydroperoxide groups can be readily detected by addition of acidified, solvent-soluble iodide ion which is directly converted to iodine giving a yellow/brown coloration.
The formation of the oxidative prepoly-merizate is usually accompanied by an increase in vis-cosity since the hydroperoxide groups begin slowly to decompose and generate cross-links as soon as they are formed. Usually therefore the oxidative prepoly-merizate will have a Gardner viscosity at 25C of at least B/C and is advantageously at least M and is preferably higher, for example R/S or even higher.
It is however desirable that the oxidative prepoly-merizate be readily miscible with the free-radical-polymerizable monomer and this puts a practical limitation on the viscosity that can be employed.
While oxidative prepolymerizates based on oxidatively polymerizable monomers are not excluded, those prepolymerizates that tend to be the more effective in practice include the oxidative pre-polymerizates derived from air-bodying of compounds of the type described in VSP 4,145,248. Such polymers (which may be termed "prepolymers" to accord with the use of the term "oxidative prepolymerizates" to describe the result of air-bodying such polymers are represented by tne following structure:
~ (E)m~R2~n .,~ .
~L2~6~
where Rl is a radical of molecular weight less than about 2000 obtained by removal of active hyd.rogen from an hydrogen compound selected from -the group consisting oE water, alcohols, thiols, carboxylic acids, carboxy]ic amides, and amines. The backbone of the radical Rl may be a hydrocarbon moiety, a polyether moiety, a polyester moiety, a polyamide moiety, or a polyurethane moiety and can be selected to enhance the compatibility of the oxidative prepolymerizate with the ethylenically-unsaturated free radical polymerizable monomer. n isthe functionality of Rl and is in the range oE 1 to 10, the produc-t of n and m (the number of E groups per segment) being in the range of about 4 to about 60. R2 is selected from the group consisting of hydrogen and C
to C10 saturated or unsaturated organic radicals. The R2 group may for example be a hydrocarbon radical, an acyl group such as acetyl or acrylyl, or a 1,2-epoxy group such as glycidyl. E is a moiety containing a radical having an activated olefinic unsaturation ~,y to an activating oxygen or sulfur atom and is present in sufficient amount to provide a ~,y unsaturation equivalent of less than about 250. The ~,y unsaturation equivalent conforms to the accepted definition of the term equivalent, i.e., it is the weight containing one unit of unsaturation. Preferably the ~, r unsaturation is less than about 150 and is more preferably in the range of about 115 to about 120. Advantageously the value of m is at least 3 and the allyloxy groups are present in the molecule in groups of three or more to provide a close spatial relationship between them.
Advantageously the ~,y unsaturation is supplied by an allyl group provided by an E group represented by the structure CH2 ~ ICH - 0
ETHYLENICALLY UNSATURATED POLYMERIZABLE COMPOSITIONS
_ This invention relates to a free-radical-polymerizable composition and to a polymerization process and more specifically to a free-radical-poly-merizable composition containing a polymerizable initiator and to a process for initiating the poly-merization of free-radical-polymerizable monomers with a polymerizable initiator.
Thus the invention relates to compositions containing a polymerizable initiator that not only initiates polymerization reactions but also apparently enters into the polymerization reactions and modifies the properties of final polymers obtained.
DESCRIPTION OF THE PRIOR ART
_ Typically a free radical polymerization initiator is a peroxide, a peracid, a perester or an azo derivative that is capable of generating free radicals which initiate polymerization of ethyleni-cally unsaturated monomers. The molecule does not take part in the polymerization to the extent of becoming incorporated into the polymer molecule as a comonomer.
These initiators are highly active and sometimes dangerously unstable and need to be handled with great care. For this reason they are used under carefully controlled conditions.
One constraint on conventiQnal free-radical-initiation is that it is usually strongly inhibited by the presence of oxygen such that polymerization reactions have to be conducted in an inert atmosphPre.
"~
~6~
Conventional initiators have an activation temperature below which they are not very active so that free-radical polymerization reacti.ons are conventionally carried out at elevated temperatures. Since such reactions are usually also exothermix it is necessary to equip polymerization vessels with elaborate temperature control facilities, The initiators used in the present invention however are not only highly stable and highly reactive but they have the capacity actually to enter into a copolymerization reaction with the ethylenically-unsaturated, free radical-polymerizable monomer and so produce copolymers that can be tailored to the desired end use. In addition the initiators are very active even at room temperature so that the reaction mixture need not be heated.
A further advantage is that, unlike conventional initiators, they function as oxygen scavengers and so work effectively in the presence of oxygen. Elaborate closed reaction vessels are not therefore required.
It is recognized that often it is advantageous to operate in the absence of air so as to reduce color body formation and to maximise structurai uniformity. The initiators of the invention are even more effective in the absence of air and permit ready access to these same advantages.
DESCRIPTION OF THE INVE~TIO~
The present invention provides a process for the polym2rization o~ a non-air-curable mono-ethylenically-unsaturated, free-radical-polymerizable monomer which comprises:
A process for the polymerization of a non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer which comprises:
A. Incorporating in the monomer an oxidative prepolymerizate of an oxidatively polymerizable compound having a structure comprising at least two unsaturations which are .j ~^ . ;.
6~
-2a-each ~ ,y to oxygen or sulfur activating the unsaturations towards oxidative polymerization, to provide a concentration of from about l to abou-t 200 parts by weight of oxidative prepolymerizate per mole of non-air-curing monomer, the oxidatively polymerizable compound being represented by the structure:
l ~ )m R2~ n where Rl is a radical characterized by a molecular weight less than about 2000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the functionality of Rl is n, and is in the range of l to lO, where R2 is selected from the group consisting of hydrogen and Cl and C10 organic radicals, where E
is a moiety containing a radical having an activated olefinic unsaturation ~ ,y to the activating group and is present in sufficient amount to provide a ~ ,y -unsaturation equivalent of less than about 250, where m is the average number of E
moieties in the n segments of the structure and where the product of m and n is in the range of about 4 to about 60; and in which the non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer is a (meth)-acrylic ester containing from 4 to 14 carbon atoms; and s. activating the oxidative prepolymerizate to copolymerize with the non-air-curing monomer.
There is also provided, in a further embodiment to this invention, a process for the polymerization of a non-air-curing mono-ethylenically-unsaturated free-radical-polymerizable monomer which comprises:
A. forming an oxidative prepolymerizate by bringing into contact with air the reaction product of an alcohol and allyl glycidyl ether comprising at least four (4) 63~
-2b-allyloxy groups per hydroxy group of the alcohol.
B. adding the non-air-curing free-radical-polymerizable monomer to the oxidative prepolymerizate to provide a concentration of oxidative prepolymerizate of 10 to 50 parts by weight per mole of non-air-curing monomer; and S C. activating the oxidative prepolymerizate toward free-radical copolymerization with the non-air-curing free-radical polymerizable monomer by means of a cobalt drier salt.
There is also provided, in accordance with this invention, a composition comprising:
A. an oxidative prepolymerizate of an oxidatively polymerizable compound having a structure comprising at least two unsaturations which are each ~ , ~ to oxygen or sulfur activating the unsaturations towards oxidative polymerization, the oxidatively polymerizahle compound being represented by the structure:
Rl~ (E)m ~ R2] n where R1 is characterized as being a radical of molecular weight less than about 2,000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the tunctionality of R1 is n and is in the range of 1 to 10, where R2 is selected from the group consisting of hydrogen and C1 ~o C 10 organic radicals, where E is a moiety containing a radical having an activated olefinic unsaturation ~ , y to the activating group and is ~ .,J~
~L2:~L63~
present in sufficient amount to provide a ~ unsaturation equivalent of less than about 250, where m is the average number of E moieties in the n segments of the s-tructure and where the product m and n is in the range of about ~ to about 60;
B. a non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer; wherein the concentration of oxidative prepolymerizate is in the range of about 1 to about 200 parts by weight per mole of non-air-curing monomer;
and wherein the non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer is a (meth)-acrylic ester containing from 4 to 14 carbon atoms.
In still further embodiments, there is also provided a copolymer product obtained by carrying out the above described process.
OXIDATIVELY POLYMERIZABLE COMPOUND
The process of oxidative polymerization is most widely known in the context of drying oils and alkyd based paints, (which are generally long chain unsaturated acid triglycerides), and relates to a mechanism by which, in contact with air, certain molecules can cross-link. This occurs through initial formation of peroxide group intermediates which then decompose to form cross-link sites between the molecules.
Readiness to undergo oxidative polymerization is also demonstrated by the prepolymers described in USP 4,145,248 which are further described below and which provide some of the preferred oxidative prepolymerizates used in the process of the invention.
An oxidative prepolymerizate of an oxid-~Z~i3~
-4- 06-12(1099)A
tively polymerizable compound (monomer or prepolymer as indicated above) is obtained by a process in which oxygen is bubbled through the compound, (if a liquid), or its solution at a temperature that is preferably below 30C. This is continued until a significant proportion of hydroperoxide groups has been generated.
The presence of hydroperoxide groups can be readily detected by addition of acidified, solvent-soluble iodide ion which is directly converted to iodine giving a yellow/brown coloration.
The formation of the oxidative prepoly-merizate is usually accompanied by an increase in vis-cosity since the hydroperoxide groups begin slowly to decompose and generate cross-links as soon as they are formed. Usually therefore the oxidative prepoly-merizate will have a Gardner viscosity at 25C of at least B/C and is advantageously at least M and is preferably higher, for example R/S or even higher.
It is however desirable that the oxidative prepoly-merizate be readily miscible with the free-radical-polymerizable monomer and this puts a practical limitation on the viscosity that can be employed.
While oxidative prepolymerizates based on oxidatively polymerizable monomers are not excluded, those prepolymerizates that tend to be the more effective in practice include the oxidative pre-polymerizates derived from air-bodying of compounds of the type described in VSP 4,145,248. Such polymers (which may be termed "prepolymers" to accord with the use of the term "oxidative prepolymerizates" to describe the result of air-bodying such polymers are represented by tne following structure:
~ (E)m~R2~n .,~ .
~L2~6~
where Rl is a radical of molecular weight less than about 2000 obtained by removal of active hyd.rogen from an hydrogen compound selected from -the group consisting oE water, alcohols, thiols, carboxylic acids, carboxy]ic amides, and amines. The backbone of the radical Rl may be a hydrocarbon moiety, a polyether moiety, a polyester moiety, a polyamide moiety, or a polyurethane moiety and can be selected to enhance the compatibility of the oxidative prepolymerizate with the ethylenically-unsaturated free radical polymerizable monomer. n isthe functionality of Rl and is in the range oE 1 to 10, the produc-t of n and m (the number of E groups per segment) being in the range of about 4 to about 60. R2 is selected from the group consisting of hydrogen and C
to C10 saturated or unsaturated organic radicals. The R2 group may for example be a hydrocarbon radical, an acyl group such as acetyl or acrylyl, or a 1,2-epoxy group such as glycidyl. E is a moiety containing a radical having an activated olefinic unsaturation ~,y to an activating oxygen or sulfur atom and is present in sufficient amount to provide a ~,y unsaturation equivalent of less than about 250. The ~,y unsaturation equivalent conforms to the accepted definition of the term equivalent, i.e., it is the weight containing one unit of unsaturation. Preferably the ~, r unsaturation is less than about 150 and is more preferably in the range of about 115 to about 120. Advantageously the value of m is at least 3 and the allyloxy groups are present in the molecule in groups of three or more to provide a close spatial relationship between them.
Advantageously the ~,y unsaturation is supplied by an allyl group provided by an E group represented by the structure CH2 ~ ICH - 0
2 CH2 CH CH2 -The "prepolymers" of a preferred group have a backbone comprising at least one segment with the ~$3~
-6- 06-12(1099)A
formula:
{ CH ~ (I) I
A - (E)m H
where A is a moiety terminating in the residue of an active hydrogen-containing group selected from the group eonsisting of alcoholic hydroxyl, thiol, amide, earboxylic acid and secondary amine with an aetive ilydrogen removed, E is a moiety containing a radieal having an activated olefinie unsaturation, ~ , ~ to the aetivating oxygen or sulfur atom, n is the number of adjaeent (as the term is hereinafter defined~
segments having this formula, and n and m are integers and are each at least 1, provided that where one is less than 4 the other is at least 4. The prepolymers can have a plurality of adjacent segments of the above formula and by "adjacent" is meant that they are directly eonnected through a carbon-carbon bond or are indirectly connected through a ~ C-C ~ or ~ O-C
group or an oxygen or sulfur atom.
The high activity of the preferred prepoly-mers depends to a large extent on the provision of a plurality of activated double bonds advantageously in elose spatial relationship or in blocks. These double bonds are sites at which oxygen-initiated crosslinking takes place during the drying or accelerated or natural aging operation. Thus, the provision of blocks of activated double bonds each of which can provide a bond site, increases the structural strength of the erosslinks that form both inter- and intramole--7- 06-12(1099)A
cularly during drying and/or aging.
The double bonds are activated, by which is meant that by virtue of their proximity in the pre-polymer molecule to strongly electron-donating oxygen or sulfur groups they are more ready to form cross-links during the air dxying process. Examples of such electron-donating groups include ether, sulfide, hydroxyl, carboxyl, and olefinically unsaturated group. The preferred electron-donating group is an ether group.
These prepolymers may be hydrophilic in character, though hydrophilicity is not an essential characteristic of the oxidative prepolymerizates useful in the present invention. A hydrophobic polymer such as a drying oil-based paint causes the water to run off or form discrete droplets on a treated surface which, in effect, is water-proofed. A polymer possessing hydrophilic character, on the other hand, allows the surface to become wetted and, if of a porous material, allows the water to be absorbed into the material by a "wicking" effect.
Qualitatively, the term "hydrophilic"
polymer is understood to describe a polymer that can be applied to an unmodified cellulosic substrate without causing water applied to the treated substrate to run off or form discrete droplets. In other words, the polymer does not destro~ the power of the substrate to absorb water or to be wetted by it.
Quantitatively, it is found that hydropho-bic polymers have surface tensions of about 40 dynesor less (Water has a surface tension of 72 dynes).
The prepolymers can be formed by the reaction of a compound having an activated double bond and epoxy group with a molecule having a plurality of active hydrogen-containing groups
-6- 06-12(1099)A
formula:
{ CH ~ (I) I
A - (E)m H
where A is a moiety terminating in the residue of an active hydrogen-containing group selected from the group eonsisting of alcoholic hydroxyl, thiol, amide, earboxylic acid and secondary amine with an aetive ilydrogen removed, E is a moiety containing a radieal having an activated olefinie unsaturation, ~ , ~ to the aetivating oxygen or sulfur atom, n is the number of adjaeent (as the term is hereinafter defined~
segments having this formula, and n and m are integers and are each at least 1, provided that where one is less than 4 the other is at least 4. The prepolymers can have a plurality of adjacent segments of the above formula and by "adjacent" is meant that they are directly eonnected through a carbon-carbon bond or are indirectly connected through a ~ C-C ~ or ~ O-C
group or an oxygen or sulfur atom.
The high activity of the preferred prepoly-mers depends to a large extent on the provision of a plurality of activated double bonds advantageously in elose spatial relationship or in blocks. These double bonds are sites at which oxygen-initiated crosslinking takes place during the drying or accelerated or natural aging operation. Thus, the provision of blocks of activated double bonds each of which can provide a bond site, increases the structural strength of the erosslinks that form both inter- and intramole--7- 06-12(1099)A
cularly during drying and/or aging.
The double bonds are activated, by which is meant that by virtue of their proximity in the pre-polymer molecule to strongly electron-donating oxygen or sulfur groups they are more ready to form cross-links during the air dxying process. Examples of such electron-donating groups include ether, sulfide, hydroxyl, carboxyl, and olefinically unsaturated group. The preferred electron-donating group is an ether group.
These prepolymers may be hydrophilic in character, though hydrophilicity is not an essential characteristic of the oxidative prepolymerizates useful in the present invention. A hydrophobic polymer such as a drying oil-based paint causes the water to run off or form discrete droplets on a treated surface which, in effect, is water-proofed. A polymer possessing hydrophilic character, on the other hand, allows the surface to become wetted and, if of a porous material, allows the water to be absorbed into the material by a "wicking" effect.
Qualitatively, the term "hydrophilic"
polymer is understood to describe a polymer that can be applied to an unmodified cellulosic substrate without causing water applied to the treated substrate to run off or form discrete droplets. In other words, the polymer does not destro~ the power of the substrate to absorb water or to be wetted by it.
Quantitatively, it is found that hydropho-bic polymers have surface tensions of about 40 dynesor less (Water has a surface tension of 72 dynes).
The prepolymers can be formed by the reaction of a compound having an activated double bond and epoxy group with a molecule having a plurality of active hydrogen-containing groups
3~
-8- 06-12(1099)A
selected from alcoholic hydroxyl, thiol, amide, carboxylic acid and secondary amine groups. ~here it is also desirable that the polymer be hydrophilic it is often preferred that hydroxyl groups should provide the active hydrogen-containing groups. The prepolymer preferably should not contain primary or secondary amine groups or phenolic hydroxyl groups since such groups may interfere with the drying reaction.
The prepolymers can for example, be pre-pared by the reaction of a backbone compound having at least one and preferably from 1 to 6 moieties containing active hydrogen-containing groups with a compound containing both an epoxide group and an activated double bond in proportions such that from 1 to 20 epoxide radicals are provided for each active hydrogen-containing groups on the backbone compound and the polymer produced has at least four activated double bonds and provided further that the ~ , zr activated unsaturation equivalent is at most about 250 and is preferably less than about 150 and is even more preferably in the range of about 115 to about 120.
Alternatively, the prepolymer can be formed ~rom a polymer chain having a plurality of adjacent pendant hydroxyl groups, reacted with, for example, allyl chloride using the techniques of Williamson's ether synthesis~ Alternatively, the same Williamson synthesis technique may be employed using a polymer chain with pendant halogen atoms and an unsaturated alcohol such as allyl alcohol. This results in the generation of adjacent allyloxy groups pendant from the prepolymer backbone that can form a suitable block of unsaturation conferring the desired air-drying characteristics on the prepolymer.
Yet another method by which the prepolymer may ~e prepared is by the Lewis acid promoted poly-~639~
-9- 06-12(1099)A
merization of vinyl allyl ether. This reaction is selective to the vinyl group and results in a chain of carbon atoms with an allyloxy group pendant from every other carbon atom.
There are, therefore, two basic types of - prepolymer embraced by the formula [I] above. The first type comprises a backbone molecule with as little as one moiety containing an active hydrogen-containing group which is reacted with a compound containing an epoxy group and an activated terminal double bond in proportions such that at least four epoxy molecules are reacted with each baekbone molecule and preferably from 4 to 10 or even 20 epoxy molecules are reacted per active hydrogen-containing group. As a simple example reacting 1 mole of glyeol with 8 moles of allyl glycidyl ether produces a pre-polymer having the average structure CH2 ~CH2 O O
~CH2CH O ~ H ~ CH2CH ~ H
Cl H2 ICH2 O-CH -CH=CH O-CH -CH=CH
- thus providing two blocks of four adjacent aeti-vated allylie groups-assuming of course, uniform addition at both sides.In this co~ ound moiety [E]m is t 21 ~
b-CH2--CH=CH2 3n and has the double bond ~ to the activating oxygen group.
The other type of structure is obtained for example, when a backbone molecule which comprises at least four adjaeent active hydrogen-eontaining groups -10- 06-12(1099)A
is reacted with an unsaturated epoxy compound as described above or alternatively, using Williamson's ether synthesis, with allyl chloride to produce a block of pendant allylic groups. In the latter case the ether oxygen provides the activation for the double bond in the allyl group and also the group "A".
An example of such a prepolymer .is that produced by the reaction of allyl chloride with polyglycidol to produce a prepolymer having a structure with repeating units of the formula ~CH--CH2-0 o CH
CH=CH2 r Here the moiety E is t CH2-CH=CH ~ and m is 1 and n is at least 4, and the olefinic unsaturation is ~ , ~rto the activating oxygen.
The backbone compound can therefore, be a polymeric polyol such as polyethylene glycol, poly-glycerol, polyglycidol, polyvinyl alcohol, a partially hydrolyzed polyvinyl acetate, a styrene/-allyl alcohol copolymer, poly(2-hydroxyethyl acrylate), poly(vinyloxy-ethanol), a monomeric polyol such as sorbitol, mannitol, or ethylene glycol; a monomeric alcohol such as methyl alcohol or allyl alcohol; the corresponding thiols, and carboxylic acids such as acetic acid, fumaric acid, maleic acid, malonic acid and phthalic acid. Also, compounds containing a mixture of radicals can be used such as hydroxy acids, which are compounds containing the carboxy and hydroxy radicals, hydroxy amides, hydroxy ethers, hydroxy esters, and the like. However, poly-hydric alcohols having from 2 to 6 carbon atoms are ~2~63~1D
~ 06-12(1099)A
preferred and sorbitol is especially preferred.
The epoxy compound reacted with the backbone compound comprises an epoxide group and an activated double bond.
The epoxy compounds that can be used have the general formula O\
R4-CH-CH- [M] -CH=CH-R5 wherein M is absent or is a group capable of activ-ating the double bond selected from the following moieties: -CH2-O-CH2~,and -CH2~S-CH2-~ and wherein R4 and ~5 are each hydrogen or Cl to C4 alkyl groups.
It is important that the activating group does not comprise a moiety that will inhibit or deac-tivate the air-curing mechanism. Such disfavored groups include free primary and secondary amine, phenolic hydroxyl, and thiol groups.
Preferred compounds include allyl glycidyl ether, and butadiene monoxide. The most preferred reactant which is also readily available at relatively low cost is allyl glycidyl ether.
An alternative preferred type of o~idative prepolymerizate is obtained by the process described in U.S. Application Serial No. 150,789, filed May lg, 1980 now U.S. Patent 4,289,864, issued September 15, 1981. The process therein described comprises passing oxygen through an oxidatively polymerizable monomer maintained at a temperature of 30C. or below, said monomer having a structure comprising at least two unsaturations, with no more than three of said unsaturations being ~ , zr to a nucleophilic group capable of activating the unsaturation towards oxi-dative polymerization and selected from the group consisting of -O-, -S- and -C-O-I
~2~63~
-12- 06-12(1099)A
so as to polymerize the monomer oxidatively and raise the viscosity of the system to a desired level.
For the purposes of the present invention the monomer that is oxidatively polymerized by the above process preferably comprises at least two groups with the formula -Q-CH2-CH=CH2 where Q is one of the nucleophilic groups indicated above, and is preferably an -0- group. Of course the same group can be used to "activate" several unsaturated bonds as for example in diallyl ether.
The group containing the activated unsatu-ration is usually an allyl radical. It can, however, be a homolog of such a group. It is often useful to have the unsaturation that is ~ , a~to the activating group conjugated with another unsaturated group in the same chain.
Typical unsaturated groups include, for example: -CH2CH=CH2, -CH2-CH=CH-CH3 ("cis" and "trans" versions), -CH2-CH=C ~, -CH2C~CH3)=CH2, and -CH(CH3)CH=CH2. Since the monomer comprises at least two or three such groups it is convenient to refer to them as di/tri olefinic monomers.
The molecule need not contain only the groups and moieties indicated. Other non-interfering functional or non-functional groups such as ester, amide, nitrile, carboxylic acid~ ketone, carboxy-aldehyde, sulfonamide, and the like can be present in the molecule. Indeed, sometimes functional groups can be very significant in providing a monomer that will result in a polymer with an appropriate degree of hydrophilicity, polarity, and substantivity.
Very often, however, the preferred molecules are as simple as possible since these tend also to be relatively cheap. An excellent monomer starting material is 1,2 diallyloxy-ethane. Other ~2~6~
-13- 06-12(1099)A
possible monomers include 1, ~-diallyloxy-2~butene, 1,3-diallyloxy-2-propanol, diallyl sulfide, ~ vinyl-oxyethyl allyl ether, diallyl succinate, diallyl maleate, diallyl fumarate, diallyl adipate, diallyl phthalate, triallyl cyanurate, triallyl orthoformate and dimethallyl malonate. Of these, the polyallyl ethers are preferred.
FORMATION OF THE OXIDATIVE PREPOLYMERIZATE
The oxidative polymerization process is preferably carried out at temperatures of 50C. or lower such as from 5 to 30C. and preferably from 10C. to 25C. and can involve the oxidatively poly-merizable prepolymer or monomer alone, (either will conventionally be a liquid under normal conditions) or a solution or emulsion of the prepolymer/monomer in a solvent.
The temperature of the reaction is found to be important in that low temperatures are required if reactive peroxy and hydroperoxy sites that are applic-able to air-curing chemistry are to be obtained and accumulated in adequate numbers. Advantageously the oxidative polymerization process is carried out under the above stated conditions for a sufficient time to provide a concentration of from 0.005 to 2.0 millimoles peroxide and hydroperoxide per gram and preferably from 0.2 to 1.0 millimoles per gram.
The time during which the oxygen is passed through the prepolymer/monomer depends largely on the rate at which oxygen is absorbed, that is, in effect, gas depression effectiveness, prepolymer/monomer reac-tivity, and the viscosity of the desired oxidative prepolymerizate. The time may be shortened by the presence of soluble metallic drier salts such as cobaltous acetate, cobaltous octoate, manganous acetate, and other salts or soluble chelates and complexes of 3 2~3~
-14- 06-12(1099~A
transition metals that are known generically as "metallic driers" in the paint field. Organic peroxides such as benzoyl peroxide and similar hydroperoxides are also found to be effective either alone or in conjunction with tertiary amines ~for peroxides) or with the metallic driers described above. Generally, from 0.001 to 5.0 percent by weight of such an additive or additive combination based on the prepolymer/monomer weight is found to be effective.
The oxygen can be supplied either as a pure gas or as a mixture with other inert gases such as, for example, air~ In general, air is preferred even though the reaction may be longer than when a gas with a higher oxygen content is used. The oxygen partial pressure may be widely varied but in practice atmospheric pressure is usually found to be con-venient. Conditions which favor oxygen dissolution such as sparging, agitation, stirring, dispersing, counter current mixing and the like will also speed oxidative prepolymerization.
The passage of oxygen is continued until, as a result of the oxidative polymerization, the desired "built" viscosity for the oxidative prepoly-meri~.ate is reached. This viscosity may be, for example, a Gardner viscosity at 25C. at least B/C, is advantageously at least M and is preferably from ~/S to Z-4. A viscosity in this range may be reached in a matter of hours, days, or even weeks depending primarily on the reactivity of the monomers, the number of activated saturations in the molecule, the number of polyunsaturate blocks, the presence/
absence of solvent, the reaction temperature, the presence/absence of metallic driers or other catalysts and the partial pressure of the oxygen in the reaction mixture.
~2~63~0 - --15- 06-12(1099)A
It should be noted that the reaction conditions chosen are those which unmistakably lead to oxidative polymerization or oxygen promoted poly-merization of the metallic drier-promoted, air-curing alkyd resin type, not that of vinyl (addition) poly-merization typified by the styryl, acrylic/methacrylic, vinyl, etc. systems. The latter, as is known to those skilled in the art, occurs only in the presence of free radical producing additives (i.e. initiators) and near total absence of radical inhibitors--including, among others, free dissolved oxygen, hydroquinones and their derivatives, homologs, etc., phenols, mercaptans, quinones, and (poly) primary or secondary amines. Since the oxidative polymerization reaction systems are continually sparged with air (2)' the initial oxygen rich phase assures that the reaction will overwhelmingly be of the oxidative polymerization type.
FREE RADICAL POLYMERIZABLE COMPOSITION
_ The other component of the copolymer of the - invention is a non-air-curing mono-ethylenically-un-saturated, free-radical-polymerizable monomer or mixture of monomers. The nature of the molecule is not critical so long as it is activated towards free-radical polymerization via the double bond by free-radical moieties present in the oxidative prepoly-merizate as a result of the oxidative polymeriza~
tion process.
Suitable monomers include vinylaromatic monomers such as styrene, chlorostyrene, d -methyl styrene and vinyl toluene; vinyl derivatives such as vinyl ethers, vinyl esters, vinylamides, vinylimides and vinyl halides; acrylic derivatives such as (meth3-acrylonitrile, (meth)acrylamide, (meth)acrylic acid, and (meth)acrylic esters containing from 4 to 14 carbon 6~
-16- 06-12(1099)A
atoms and mono- and di-esters of maleic and fumaric acid containïng from 5 to 20 carbon atoms. The preferred monomers are (meth~-acrylic esters containing from 4 to 14 carbon atoms.
Mixtures of such monomers can be used to achieve any desired balance of properties in the final interpolymers. Generally however it is preferable to select the monomers such that all can be brought together at room temperature to react. It is generally most convenient therefore if the reactants can be dissolved in a common solvent which is most preferably one of the reactants.
It is not however beyond the scope of this invention to provide that the reaction occurs in a suitable non-polymerizable solvent or that a gaseous reactant be contacted with the others in a multiphase reaction.
THE PROCESS
Activation of the reaction between the oxidative prepolymerizate and the non-air-drying free-radical-polymerizable comonomer can take place without any outside agent being involved. Generally such activation requires an elevated temperature of at least 6~C. and often about 80C. before a reason-able reaction rate can be achieved. It is found however that the addition of minor amounts of a metallic drier to the oxidative prepolymerizate, is extremely beneficial.
~here the oxidative prepolymerizate is derived from prepolymers such as those described in USP 4,145,248 it is possible to add the prepolymer itself. This is because the prepolymer is able to take up oxygen from the air and form au~ogenously the oxidative prepolymerizate. Such a reaction is however usually too slow for efficient use of the present 3~ .
-17- 06-12(1099)A
invention.
The addition of from 0.001 to 1.0% by weight of a metallic drier markedly speeds up the copoly-merization and enables rapid reaction to occur even at room temperature or lower. The metallic driers are salts and soluble complexes of transition elements such as cobalt and manganese and the typical represen-tatives include cobaltous acetate, citrate, acetyl-acetonate and 2-ethyl hexanoate, and the corresponding soluble manganous salts and complexes. Generally salts are preferred to complexes since they appear to generate higher reaction rate. The metallic drier is usually added in the form of a solution in a suitable solvent that will ensure dispersion of drier through-out the reaction mixture.
The proportions of the components can varyvery widely depending on the nature of the ~roduct to be obtained and in general a range of from about 1 to about 200 parts by weight of the oxidative prepolymer-izate per mole of the non-air-curing ethylenically unsaturated monomer can be used. More usually this range will be from about 5 to about 100 parts by weight of the oxidative prepolymerizate per mole of the monomer and more preferably from about 10 to about 50 parts by weight of the oxidative prepolymer-izate per mole of the monomer. As above indicated the proportions selected depend largely on the intended use. It is possible for example to use the oxidative prepolymerizate as a catalyst for polymer-izing a monomer at room temperature without use oftraditional free-radical generators. Such reactions are very useful since the reacting monomers can be selected such that the mixture with the oxidative polymerizate is a liquid that is relatively stable at at ambient temperatures but which polymerizes within 3~
-18- 06-12(1099)A
seconds on addition of a meta:Llic drier. This promises a wide field of utility in adhesives, moldings and casting operations. These uses are particularly favored by the relative insensitivity of the system to the presence of oxygen which would normally inhibit free-radical reactions. In such an application the weight percentage of oxidative prepolymerizate would conveniently range from l to 25~ of the combined monomer composition/oxidative prepolymerizate weight.
Other fields of use require a larger percentage of the oxidative prepolymerizate than is required for merely initiating the monomer polymerization. As an example, it is known from USP 4,145,248 and USP 4,289,864 that certain hydrophilic oxidative prepolymerizates are exceptionally useful for improving the physical properties of fibrous substrates. This end use is particularly significant in improving the wet and dry strengths of cellulosic substrates. The present invention provides a method of improving the properties obtained even further by incorporation of a suitable monomer as a component of the mixture applied to the substrate. Since the oxidative prepolymerizate and the monomer actually copolymerize, the possibilities of varying the properties of the final product by varying the nature and proportions of the components are endless.
It will be noted that the use of the oxida-tive prepolymerizate as an initiator results in no by-products since the initiator is a polymer that is incorporated into the final product. Thus it is capable of acting as a genuine internal plasticizer or other property modifier.
The use of an oxidative prepolymerizate as an initiator is ideal for paints and adhesives in view of its relative insensitivity to air and 63~
-19- 06-12(1099)A
temperature and because it leads to simultaneous drying throughout the mass, not merely at the surface initially with slower solidification of the body material.
DESCRIPTION OF PREFERRED EMBODIMENTS
The invention is now described in more detail in the context of the following Examples which illustrate various compositions and processes relating to the invention claimed.
EXAMPLE I
This Example describes the production of an oxidative prepolymerizate catalyst composition useful in the process of the invention.
A reaction vessel was charged with ethylene glycol which was reacted with allyl glycidyl ether in a 1:10 mole ratio in the presence of boron trifluoride/
etherate catalyst. The allyl glycidyl ether was added gradually over a period of several hours and the liquid product obtained had a Gardner viscosity at 25C. of F. The allyloxy equivalent was about 120.
Five Hundred grams of this product were vacuum stripped, placed in a flask and air-sparged at 50C. for 54-hours. After this period the Gardner viscosity had increased to Z-2. The resin was just pourable and was clear and colorless.
The following procedure was used for deter-n~ining the peroxide content. A 2 gram sample of the resin was added to a flask and was dissolved in 50 ml of a solvent mixture of acetic acid and chloroform in the weight ratio of 35:~5. Four lumps of dry ice, each approximately 1 ccm in volume were added to the solution which was swirled to allow dissolved oxygen to be removed by entrainment in the subliming carbon dioxide. One ml of a freshly prepared saturated potassium iodide solution was added to the sample ~Z~63~3 solution, the ~lask was stoppered and the mixture was stirred for 15 minutes. One hundred ml o~ deaerated distilled water and approximately 0.2 g. o~ an iodine titration indicator, sold by Taylor Chemical Company under the tradename Paragon were added and the mixture was titrated with sodium thiosulfate to a colorless end-point, permanent for one-minute. During the titration the mixture was stirred vigorously under a nitrogen blanket. The peroxide content calculated as hydrogen peroxide was 0.89 moles per gram.
This Example illustrates the process of the invention.
A glass tube was charged with 4.0g of methyl methacrylate (containing about 50 to 100 ppm of hydroquinone as stabilizer) and 0.4g of the oxidative prepolymerizate catalyst of Example 1. The two mixcible liquids were stirred for 30 seconds to effect homogeneity; then 0.025g of a 12% cobaltous octoate solution in cyclohexane was added with stirring.
A srnall quantity of the mixture obtained was spread as a moderately thick film on a stainless steel strip of metal and allowed to cure. The liquid became tacky after 15-20 minutes while remaining optically very clear. No signs o~ cracking, chipping or brittleness were observed after a three hour cure period.
The film had good adhesion to the metal surface and a hardness, as measured by ASTM Method D 3363-4, of HB/F after three (3) hours and better than 4H after a day. For purposes of comparison the oxidative prepolymerizate alone, activated by the cobalt catalyst was cast on a ~63~
~21-stainless steel strip. Even after six (6) hours from the point at which a film formed over the surface of the liquid, it had only a 2B hardness, (measured by the above technique), and showed low adhesion to the stainless steel plate and poor toughness. It tended to break into crumbs when rubbed between the fingers.
It would appear therefore that a genuine copolymerization has occurred to produce a new copolymer.
This Example illustrates the ineffectiveness of the cobaltous octoate catalyst per se or a benzoyl peroxide catalyst acting alone in the initiation of polymerization of inhibited methyl methacrylate.
Two samples of 49 of methyl methacrylate, each containing 25-50 ppm of hydroquinone as inhibitor, were prepared.
Both samples were treated with 0.025g of a 12% solution in cyclohexane of cobaltous octoate and the second sample additionally received O.lg of benzoyl peroxide. Both were left at room temperature in the presence of air for four (4) hours.
Neither sho~ed any evidence of reaction by increased viscosity.
Each sample was then treated with Q.4g of the oxidative prepolymerizate of Example 1 stirred in at room temperature until a homogeneous liquid was obtained. Both produced a hard, tough, clear, solvent insolu~le resin.
This Example demonstrates the relative stability of methyl methacrylate monomer in the presence of the oxidative prepolymerizate when allowed to stand at room .," . ~
,. ,,;
35~0 temperature in the presence of air but absence of the cobaltous salt.
A loosely capped vial containing 3g of methyl methacrylate and lg of the oxidative prepolymerizate of Example 1 ~as stirred until the solution was homogeneous and left at room temperature. No change in viscosity was observed after 24-days.
However within 30-minutes of the addition of 0.012g of 12% cobaltous octoate the contents had polymerized to a hard ~ough casting.
In this Example a number of catalysts were evaluated for their activity in initiating polymerization of a mixture of ~.0g of methyl methacrylate; 0.4g of ethylene glycol dimethacrylate and 0.5g of the oxidative prepolymerizate of Example l. All reactions were run in loosely-capped 2-dram vials and were allowed to proceed to rigid castings.
In each case 0.010 to 0.012g of tas supplied) metallic drier composition was added to the above mi~ture.
It was found that cobaltous and cobaltic salts (the acetates, octanoates, 2-ethylhexanoates, naphthenates and tallates) promote extremely fast polyrnerizations. These salts are also known to promote rapid gelat:lon of the oxidative prepolymerizates alone.
On the other hand the corresponding largely covalent acetylacetonates (chelates) are comparatively slow reacting catalysts.
This Example illustrates the effectiveness of the process of the invention with vinylaromatic monomers such as styrene, 3~
-~3-A mixture was prepared of 4.0g of inhibited styrene monomer, (commercial styrene conventionally contains an inhibitor to prevent autogenous or premature reaction), and 0.4g of the oxidative prepolymerizate of Example 1. The mixture was thoroughly mixed and nitrogen-sparged for 15 minutes before the introduction of 0.0125g of a 12% solution in cyclohexane of cobaltous octanoate.
The mixture gelled after 45 minutes and set to a hard brittle casting after 90 minutes.
EXAMPLE__7 This Example illustrates the process of the invention applied to a vinyl monomer.
A reaction mixture was prepared containing lg of ethylene glycol dimethacrylate and 0.25g of the preplymerizate of Example 1 and vinyl acetate. The reaction mixture was sparged with nitrogen at room temperature until after the addition of 0.02g of a 6% solution of cobaltous naphthenate. The mixture gelled in 3.75 rninutes and set to a hard casting in approximately 15 minutes.
EXAMPLE ~
This Example illistrates the retardant effect of oxygen on the polymerization rate of the process of the invention.
In each of the following runs the monomer was a 10:1 by ~eight mixture of methyl methacrylate and ethylene glycol dimethacrylate. The oxidative prepolymerizate was that obtained in Example 1. The gas indicated was sparged through the reaction rnixture for the duration of the reaction until the mixture had gelled. All runs were per~ormed at room temperature in screw capped glass tubes. The results are set forth in Table 1.
, ~
,~,,..~,, The above runs show clearly that although oxygen is an inhibitor of free-radical polymerization reactions, the oxidative prepolymerizate is able, in effect, to remove it from the reaction when operating in its oxidative polymerization mode and generate the catalytic entities that permit the free-radical copolymerization of the reaction mixture.
Run #7 shows clearly that even an active conventional hydroperoxide catalyst i5 comparatively ineffective in the presence of air to effectuate polymerization.
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This Example illustrates the utility of another type of oxidative prepolymerizate in the process of this invention in the formula-tion of an adhesive composition.
Trimethylolpropane diallyl ether was oxidatively polymerized by sparging with air at 70C for 68.5 hours to a Gardner viscosity at 25C of Z-4. No cobalt catalyst was used.
The peroxlde content was 0.37 moles per gram.
A mixture of 2.5g of n-butyl acrylate, 2.5g of the product known by the trade mark "Carbowax 200" dimethacrylate and 0.5g of the oxidative prepolymerizate based on trimethylol propane diallyl ether was stirred until homogeneous.
A 12% solution of cobaltous 2-ethyl hexanoate in cyclohexane (0.012g) was added and quickly stirred into the reaction mixture at room temperature. This mixture was then applied in roughly equal amounts onto flat, dry, clean surfaces of two polywood blocks. The blocks were then clamped together for one minute. While much of the curing probably occurs in the first 6-8 hours under these conditions, it is possible that full cure is not reached for 1-2 days. The cured composite withstands mechanical shock and twisting forces without bond rupture.
The above Examples are for the purpose of illustration only and are not intended to imply any necessary limitation on the inherent scope of the invention. It will be appreciated that many minor modifications to, or variations in, the formulations and processes descibed above could be made without departing from the essential scope of the invention.
t is intended that all such modifications and variations should be embraced within the purview of this invention.
-8- 06-12(1099)A
selected from alcoholic hydroxyl, thiol, amide, carboxylic acid and secondary amine groups. ~here it is also desirable that the polymer be hydrophilic it is often preferred that hydroxyl groups should provide the active hydrogen-containing groups. The prepolymer preferably should not contain primary or secondary amine groups or phenolic hydroxyl groups since such groups may interfere with the drying reaction.
The prepolymers can for example, be pre-pared by the reaction of a backbone compound having at least one and preferably from 1 to 6 moieties containing active hydrogen-containing groups with a compound containing both an epoxide group and an activated double bond in proportions such that from 1 to 20 epoxide radicals are provided for each active hydrogen-containing groups on the backbone compound and the polymer produced has at least four activated double bonds and provided further that the ~ , zr activated unsaturation equivalent is at most about 250 and is preferably less than about 150 and is even more preferably in the range of about 115 to about 120.
Alternatively, the prepolymer can be formed ~rom a polymer chain having a plurality of adjacent pendant hydroxyl groups, reacted with, for example, allyl chloride using the techniques of Williamson's ether synthesis~ Alternatively, the same Williamson synthesis technique may be employed using a polymer chain with pendant halogen atoms and an unsaturated alcohol such as allyl alcohol. This results in the generation of adjacent allyloxy groups pendant from the prepolymer backbone that can form a suitable block of unsaturation conferring the desired air-drying characteristics on the prepolymer.
Yet another method by which the prepolymer may ~e prepared is by the Lewis acid promoted poly-~639~
-9- 06-12(1099)A
merization of vinyl allyl ether. This reaction is selective to the vinyl group and results in a chain of carbon atoms with an allyloxy group pendant from every other carbon atom.
There are, therefore, two basic types of - prepolymer embraced by the formula [I] above. The first type comprises a backbone molecule with as little as one moiety containing an active hydrogen-containing group which is reacted with a compound containing an epoxy group and an activated terminal double bond in proportions such that at least four epoxy molecules are reacted with each baekbone molecule and preferably from 4 to 10 or even 20 epoxy molecules are reacted per active hydrogen-containing group. As a simple example reacting 1 mole of glyeol with 8 moles of allyl glycidyl ether produces a pre-polymer having the average structure CH2 ~CH2 O O
~CH2CH O ~ H ~ CH2CH ~ H
Cl H2 ICH2 O-CH -CH=CH O-CH -CH=CH
- thus providing two blocks of four adjacent aeti-vated allylie groups-assuming of course, uniform addition at both sides.In this co~ ound moiety [E]m is t 21 ~
b-CH2--CH=CH2 3n and has the double bond ~ to the activating oxygen group.
The other type of structure is obtained for example, when a backbone molecule which comprises at least four adjaeent active hydrogen-eontaining groups -10- 06-12(1099)A
is reacted with an unsaturated epoxy compound as described above or alternatively, using Williamson's ether synthesis, with allyl chloride to produce a block of pendant allylic groups. In the latter case the ether oxygen provides the activation for the double bond in the allyl group and also the group "A".
An example of such a prepolymer .is that produced by the reaction of allyl chloride with polyglycidol to produce a prepolymer having a structure with repeating units of the formula ~CH--CH2-0 o CH
CH=CH2 r Here the moiety E is t CH2-CH=CH ~ and m is 1 and n is at least 4, and the olefinic unsaturation is ~ , ~rto the activating oxygen.
The backbone compound can therefore, be a polymeric polyol such as polyethylene glycol, poly-glycerol, polyglycidol, polyvinyl alcohol, a partially hydrolyzed polyvinyl acetate, a styrene/-allyl alcohol copolymer, poly(2-hydroxyethyl acrylate), poly(vinyloxy-ethanol), a monomeric polyol such as sorbitol, mannitol, or ethylene glycol; a monomeric alcohol such as methyl alcohol or allyl alcohol; the corresponding thiols, and carboxylic acids such as acetic acid, fumaric acid, maleic acid, malonic acid and phthalic acid. Also, compounds containing a mixture of radicals can be used such as hydroxy acids, which are compounds containing the carboxy and hydroxy radicals, hydroxy amides, hydroxy ethers, hydroxy esters, and the like. However, poly-hydric alcohols having from 2 to 6 carbon atoms are ~2~63~1D
~ 06-12(1099)A
preferred and sorbitol is especially preferred.
The epoxy compound reacted with the backbone compound comprises an epoxide group and an activated double bond.
The epoxy compounds that can be used have the general formula O\
R4-CH-CH- [M] -CH=CH-R5 wherein M is absent or is a group capable of activ-ating the double bond selected from the following moieties: -CH2-O-CH2~,and -CH2~S-CH2-~ and wherein R4 and ~5 are each hydrogen or Cl to C4 alkyl groups.
It is important that the activating group does not comprise a moiety that will inhibit or deac-tivate the air-curing mechanism. Such disfavored groups include free primary and secondary amine, phenolic hydroxyl, and thiol groups.
Preferred compounds include allyl glycidyl ether, and butadiene monoxide. The most preferred reactant which is also readily available at relatively low cost is allyl glycidyl ether.
An alternative preferred type of o~idative prepolymerizate is obtained by the process described in U.S. Application Serial No. 150,789, filed May lg, 1980 now U.S. Patent 4,289,864, issued September 15, 1981. The process therein described comprises passing oxygen through an oxidatively polymerizable monomer maintained at a temperature of 30C. or below, said monomer having a structure comprising at least two unsaturations, with no more than three of said unsaturations being ~ , zr to a nucleophilic group capable of activating the unsaturation towards oxi-dative polymerization and selected from the group consisting of -O-, -S- and -C-O-I
~2~63~
-12- 06-12(1099)A
so as to polymerize the monomer oxidatively and raise the viscosity of the system to a desired level.
For the purposes of the present invention the monomer that is oxidatively polymerized by the above process preferably comprises at least two groups with the formula -Q-CH2-CH=CH2 where Q is one of the nucleophilic groups indicated above, and is preferably an -0- group. Of course the same group can be used to "activate" several unsaturated bonds as for example in diallyl ether.
The group containing the activated unsatu-ration is usually an allyl radical. It can, however, be a homolog of such a group. It is often useful to have the unsaturation that is ~ , a~to the activating group conjugated with another unsaturated group in the same chain.
Typical unsaturated groups include, for example: -CH2CH=CH2, -CH2-CH=CH-CH3 ("cis" and "trans" versions), -CH2-CH=C ~, -CH2C~CH3)=CH2, and -CH(CH3)CH=CH2. Since the monomer comprises at least two or three such groups it is convenient to refer to them as di/tri olefinic monomers.
The molecule need not contain only the groups and moieties indicated. Other non-interfering functional or non-functional groups such as ester, amide, nitrile, carboxylic acid~ ketone, carboxy-aldehyde, sulfonamide, and the like can be present in the molecule. Indeed, sometimes functional groups can be very significant in providing a monomer that will result in a polymer with an appropriate degree of hydrophilicity, polarity, and substantivity.
Very often, however, the preferred molecules are as simple as possible since these tend also to be relatively cheap. An excellent monomer starting material is 1,2 diallyloxy-ethane. Other ~2~6~
-13- 06-12(1099)A
possible monomers include 1, ~-diallyloxy-2~butene, 1,3-diallyloxy-2-propanol, diallyl sulfide, ~ vinyl-oxyethyl allyl ether, diallyl succinate, diallyl maleate, diallyl fumarate, diallyl adipate, diallyl phthalate, triallyl cyanurate, triallyl orthoformate and dimethallyl malonate. Of these, the polyallyl ethers are preferred.
FORMATION OF THE OXIDATIVE PREPOLYMERIZATE
The oxidative polymerization process is preferably carried out at temperatures of 50C. or lower such as from 5 to 30C. and preferably from 10C. to 25C. and can involve the oxidatively poly-merizable prepolymer or monomer alone, (either will conventionally be a liquid under normal conditions) or a solution or emulsion of the prepolymer/monomer in a solvent.
The temperature of the reaction is found to be important in that low temperatures are required if reactive peroxy and hydroperoxy sites that are applic-able to air-curing chemistry are to be obtained and accumulated in adequate numbers. Advantageously the oxidative polymerization process is carried out under the above stated conditions for a sufficient time to provide a concentration of from 0.005 to 2.0 millimoles peroxide and hydroperoxide per gram and preferably from 0.2 to 1.0 millimoles per gram.
The time during which the oxygen is passed through the prepolymer/monomer depends largely on the rate at which oxygen is absorbed, that is, in effect, gas depression effectiveness, prepolymer/monomer reac-tivity, and the viscosity of the desired oxidative prepolymerizate. The time may be shortened by the presence of soluble metallic drier salts such as cobaltous acetate, cobaltous octoate, manganous acetate, and other salts or soluble chelates and complexes of 3 2~3~
-14- 06-12(1099~A
transition metals that are known generically as "metallic driers" in the paint field. Organic peroxides such as benzoyl peroxide and similar hydroperoxides are also found to be effective either alone or in conjunction with tertiary amines ~for peroxides) or with the metallic driers described above. Generally, from 0.001 to 5.0 percent by weight of such an additive or additive combination based on the prepolymer/monomer weight is found to be effective.
The oxygen can be supplied either as a pure gas or as a mixture with other inert gases such as, for example, air~ In general, air is preferred even though the reaction may be longer than when a gas with a higher oxygen content is used. The oxygen partial pressure may be widely varied but in practice atmospheric pressure is usually found to be con-venient. Conditions which favor oxygen dissolution such as sparging, agitation, stirring, dispersing, counter current mixing and the like will also speed oxidative prepolymerization.
The passage of oxygen is continued until, as a result of the oxidative polymerization, the desired "built" viscosity for the oxidative prepoly-meri~.ate is reached. This viscosity may be, for example, a Gardner viscosity at 25C. at least B/C, is advantageously at least M and is preferably from ~/S to Z-4. A viscosity in this range may be reached in a matter of hours, days, or even weeks depending primarily on the reactivity of the monomers, the number of activated saturations in the molecule, the number of polyunsaturate blocks, the presence/
absence of solvent, the reaction temperature, the presence/absence of metallic driers or other catalysts and the partial pressure of the oxygen in the reaction mixture.
~2~63~0 - --15- 06-12(1099)A
It should be noted that the reaction conditions chosen are those which unmistakably lead to oxidative polymerization or oxygen promoted poly-merization of the metallic drier-promoted, air-curing alkyd resin type, not that of vinyl (addition) poly-merization typified by the styryl, acrylic/methacrylic, vinyl, etc. systems. The latter, as is known to those skilled in the art, occurs only in the presence of free radical producing additives (i.e. initiators) and near total absence of radical inhibitors--including, among others, free dissolved oxygen, hydroquinones and their derivatives, homologs, etc., phenols, mercaptans, quinones, and (poly) primary or secondary amines. Since the oxidative polymerization reaction systems are continually sparged with air (2)' the initial oxygen rich phase assures that the reaction will overwhelmingly be of the oxidative polymerization type.
FREE RADICAL POLYMERIZABLE COMPOSITION
_ The other component of the copolymer of the - invention is a non-air-curing mono-ethylenically-un-saturated, free-radical-polymerizable monomer or mixture of monomers. The nature of the molecule is not critical so long as it is activated towards free-radical polymerization via the double bond by free-radical moieties present in the oxidative prepoly-merizate as a result of the oxidative polymeriza~
tion process.
Suitable monomers include vinylaromatic monomers such as styrene, chlorostyrene, d -methyl styrene and vinyl toluene; vinyl derivatives such as vinyl ethers, vinyl esters, vinylamides, vinylimides and vinyl halides; acrylic derivatives such as (meth3-acrylonitrile, (meth)acrylamide, (meth)acrylic acid, and (meth)acrylic esters containing from 4 to 14 carbon 6~
-16- 06-12(1099)A
atoms and mono- and di-esters of maleic and fumaric acid containïng from 5 to 20 carbon atoms. The preferred monomers are (meth~-acrylic esters containing from 4 to 14 carbon atoms.
Mixtures of such monomers can be used to achieve any desired balance of properties in the final interpolymers. Generally however it is preferable to select the monomers such that all can be brought together at room temperature to react. It is generally most convenient therefore if the reactants can be dissolved in a common solvent which is most preferably one of the reactants.
It is not however beyond the scope of this invention to provide that the reaction occurs in a suitable non-polymerizable solvent or that a gaseous reactant be contacted with the others in a multiphase reaction.
THE PROCESS
Activation of the reaction between the oxidative prepolymerizate and the non-air-drying free-radical-polymerizable comonomer can take place without any outside agent being involved. Generally such activation requires an elevated temperature of at least 6~C. and often about 80C. before a reason-able reaction rate can be achieved. It is found however that the addition of minor amounts of a metallic drier to the oxidative prepolymerizate, is extremely beneficial.
~here the oxidative prepolymerizate is derived from prepolymers such as those described in USP 4,145,248 it is possible to add the prepolymer itself. This is because the prepolymer is able to take up oxygen from the air and form au~ogenously the oxidative prepolymerizate. Such a reaction is however usually too slow for efficient use of the present 3~ .
-17- 06-12(1099)A
invention.
The addition of from 0.001 to 1.0% by weight of a metallic drier markedly speeds up the copoly-merization and enables rapid reaction to occur even at room temperature or lower. The metallic driers are salts and soluble complexes of transition elements such as cobalt and manganese and the typical represen-tatives include cobaltous acetate, citrate, acetyl-acetonate and 2-ethyl hexanoate, and the corresponding soluble manganous salts and complexes. Generally salts are preferred to complexes since they appear to generate higher reaction rate. The metallic drier is usually added in the form of a solution in a suitable solvent that will ensure dispersion of drier through-out the reaction mixture.
The proportions of the components can varyvery widely depending on the nature of the ~roduct to be obtained and in general a range of from about 1 to about 200 parts by weight of the oxidative prepolymer-izate per mole of the non-air-curing ethylenically unsaturated monomer can be used. More usually this range will be from about 5 to about 100 parts by weight of the oxidative prepolymerizate per mole of the monomer and more preferably from about 10 to about 50 parts by weight of the oxidative prepolymer-izate per mole of the monomer. As above indicated the proportions selected depend largely on the intended use. It is possible for example to use the oxidative prepolymerizate as a catalyst for polymer-izing a monomer at room temperature without use oftraditional free-radical generators. Such reactions are very useful since the reacting monomers can be selected such that the mixture with the oxidative polymerizate is a liquid that is relatively stable at at ambient temperatures but which polymerizes within 3~
-18- 06-12(1099)A
seconds on addition of a meta:Llic drier. This promises a wide field of utility in adhesives, moldings and casting operations. These uses are particularly favored by the relative insensitivity of the system to the presence of oxygen which would normally inhibit free-radical reactions. In such an application the weight percentage of oxidative prepolymerizate would conveniently range from l to 25~ of the combined monomer composition/oxidative prepolymerizate weight.
Other fields of use require a larger percentage of the oxidative prepolymerizate than is required for merely initiating the monomer polymerization. As an example, it is known from USP 4,145,248 and USP 4,289,864 that certain hydrophilic oxidative prepolymerizates are exceptionally useful for improving the physical properties of fibrous substrates. This end use is particularly significant in improving the wet and dry strengths of cellulosic substrates. The present invention provides a method of improving the properties obtained even further by incorporation of a suitable monomer as a component of the mixture applied to the substrate. Since the oxidative prepolymerizate and the monomer actually copolymerize, the possibilities of varying the properties of the final product by varying the nature and proportions of the components are endless.
It will be noted that the use of the oxida-tive prepolymerizate as an initiator results in no by-products since the initiator is a polymer that is incorporated into the final product. Thus it is capable of acting as a genuine internal plasticizer or other property modifier.
The use of an oxidative prepolymerizate as an initiator is ideal for paints and adhesives in view of its relative insensitivity to air and 63~
-19- 06-12(1099)A
temperature and because it leads to simultaneous drying throughout the mass, not merely at the surface initially with slower solidification of the body material.
DESCRIPTION OF PREFERRED EMBODIMENTS
The invention is now described in more detail in the context of the following Examples which illustrate various compositions and processes relating to the invention claimed.
EXAMPLE I
This Example describes the production of an oxidative prepolymerizate catalyst composition useful in the process of the invention.
A reaction vessel was charged with ethylene glycol which was reacted with allyl glycidyl ether in a 1:10 mole ratio in the presence of boron trifluoride/
etherate catalyst. The allyl glycidyl ether was added gradually over a period of several hours and the liquid product obtained had a Gardner viscosity at 25C. of F. The allyloxy equivalent was about 120.
Five Hundred grams of this product were vacuum stripped, placed in a flask and air-sparged at 50C. for 54-hours. After this period the Gardner viscosity had increased to Z-2. The resin was just pourable and was clear and colorless.
The following procedure was used for deter-n~ining the peroxide content. A 2 gram sample of the resin was added to a flask and was dissolved in 50 ml of a solvent mixture of acetic acid and chloroform in the weight ratio of 35:~5. Four lumps of dry ice, each approximately 1 ccm in volume were added to the solution which was swirled to allow dissolved oxygen to be removed by entrainment in the subliming carbon dioxide. One ml of a freshly prepared saturated potassium iodide solution was added to the sample ~Z~63~3 solution, the ~lask was stoppered and the mixture was stirred for 15 minutes. One hundred ml o~ deaerated distilled water and approximately 0.2 g. o~ an iodine titration indicator, sold by Taylor Chemical Company under the tradename Paragon were added and the mixture was titrated with sodium thiosulfate to a colorless end-point, permanent for one-minute. During the titration the mixture was stirred vigorously under a nitrogen blanket. The peroxide content calculated as hydrogen peroxide was 0.89 moles per gram.
This Example illustrates the process of the invention.
A glass tube was charged with 4.0g of methyl methacrylate (containing about 50 to 100 ppm of hydroquinone as stabilizer) and 0.4g of the oxidative prepolymerizate catalyst of Example 1. The two mixcible liquids were stirred for 30 seconds to effect homogeneity; then 0.025g of a 12% cobaltous octoate solution in cyclohexane was added with stirring.
A srnall quantity of the mixture obtained was spread as a moderately thick film on a stainless steel strip of metal and allowed to cure. The liquid became tacky after 15-20 minutes while remaining optically very clear. No signs o~ cracking, chipping or brittleness were observed after a three hour cure period.
The film had good adhesion to the metal surface and a hardness, as measured by ASTM Method D 3363-4, of HB/F after three (3) hours and better than 4H after a day. For purposes of comparison the oxidative prepolymerizate alone, activated by the cobalt catalyst was cast on a ~63~
~21-stainless steel strip. Even after six (6) hours from the point at which a film formed over the surface of the liquid, it had only a 2B hardness, (measured by the above technique), and showed low adhesion to the stainless steel plate and poor toughness. It tended to break into crumbs when rubbed between the fingers.
It would appear therefore that a genuine copolymerization has occurred to produce a new copolymer.
This Example illustrates the ineffectiveness of the cobaltous octoate catalyst per se or a benzoyl peroxide catalyst acting alone in the initiation of polymerization of inhibited methyl methacrylate.
Two samples of 49 of methyl methacrylate, each containing 25-50 ppm of hydroquinone as inhibitor, were prepared.
Both samples were treated with 0.025g of a 12% solution in cyclohexane of cobaltous octoate and the second sample additionally received O.lg of benzoyl peroxide. Both were left at room temperature in the presence of air for four (4) hours.
Neither sho~ed any evidence of reaction by increased viscosity.
Each sample was then treated with Q.4g of the oxidative prepolymerizate of Example 1 stirred in at room temperature until a homogeneous liquid was obtained. Both produced a hard, tough, clear, solvent insolu~le resin.
This Example demonstrates the relative stability of methyl methacrylate monomer in the presence of the oxidative prepolymerizate when allowed to stand at room .," . ~
,. ,,;
35~0 temperature in the presence of air but absence of the cobaltous salt.
A loosely capped vial containing 3g of methyl methacrylate and lg of the oxidative prepolymerizate of Example 1 ~as stirred until the solution was homogeneous and left at room temperature. No change in viscosity was observed after 24-days.
However within 30-minutes of the addition of 0.012g of 12% cobaltous octoate the contents had polymerized to a hard ~ough casting.
In this Example a number of catalysts were evaluated for their activity in initiating polymerization of a mixture of ~.0g of methyl methacrylate; 0.4g of ethylene glycol dimethacrylate and 0.5g of the oxidative prepolymerizate of Example l. All reactions were run in loosely-capped 2-dram vials and were allowed to proceed to rigid castings.
In each case 0.010 to 0.012g of tas supplied) metallic drier composition was added to the above mi~ture.
It was found that cobaltous and cobaltic salts (the acetates, octanoates, 2-ethylhexanoates, naphthenates and tallates) promote extremely fast polyrnerizations. These salts are also known to promote rapid gelat:lon of the oxidative prepolymerizates alone.
On the other hand the corresponding largely covalent acetylacetonates (chelates) are comparatively slow reacting catalysts.
This Example illustrates the effectiveness of the process of the invention with vinylaromatic monomers such as styrene, 3~
-~3-A mixture was prepared of 4.0g of inhibited styrene monomer, (commercial styrene conventionally contains an inhibitor to prevent autogenous or premature reaction), and 0.4g of the oxidative prepolymerizate of Example 1. The mixture was thoroughly mixed and nitrogen-sparged for 15 minutes before the introduction of 0.0125g of a 12% solution in cyclohexane of cobaltous octanoate.
The mixture gelled after 45 minutes and set to a hard brittle casting after 90 minutes.
EXAMPLE__7 This Example illustrates the process of the invention applied to a vinyl monomer.
A reaction mixture was prepared containing lg of ethylene glycol dimethacrylate and 0.25g of the preplymerizate of Example 1 and vinyl acetate. The reaction mixture was sparged with nitrogen at room temperature until after the addition of 0.02g of a 6% solution of cobaltous naphthenate. The mixture gelled in 3.75 rninutes and set to a hard casting in approximately 15 minutes.
EXAMPLE ~
This Example illistrates the retardant effect of oxygen on the polymerization rate of the process of the invention.
In each of the following runs the monomer was a 10:1 by ~eight mixture of methyl methacrylate and ethylene glycol dimethacrylate. The oxidative prepolymerizate was that obtained in Example 1. The gas indicated was sparged through the reaction rnixture for the duration of the reaction until the mixture had gelled. All runs were per~ormed at room temperature in screw capped glass tubes. The results are set forth in Table 1.
, ~
,~,,..~,, The above runs show clearly that although oxygen is an inhibitor of free-radical polymerization reactions, the oxidative prepolymerizate is able, in effect, to remove it from the reaction when operating in its oxidative polymerization mode and generate the catalytic entities that permit the free-radical copolymerization of the reaction mixture.
Run #7 shows clearly that even an active conventional hydroperoxide catalyst i5 comparatively ineffective in the presence of air to effectuate polymerization.
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This Example illustrates the utility of another type of oxidative prepolymerizate in the process of this invention in the formula-tion of an adhesive composition.
Trimethylolpropane diallyl ether was oxidatively polymerized by sparging with air at 70C for 68.5 hours to a Gardner viscosity at 25C of Z-4. No cobalt catalyst was used.
The peroxlde content was 0.37 moles per gram.
A mixture of 2.5g of n-butyl acrylate, 2.5g of the product known by the trade mark "Carbowax 200" dimethacrylate and 0.5g of the oxidative prepolymerizate based on trimethylol propane diallyl ether was stirred until homogeneous.
A 12% solution of cobaltous 2-ethyl hexanoate in cyclohexane (0.012g) was added and quickly stirred into the reaction mixture at room temperature. This mixture was then applied in roughly equal amounts onto flat, dry, clean surfaces of two polywood blocks. The blocks were then clamped together for one minute. While much of the curing probably occurs in the first 6-8 hours under these conditions, it is possible that full cure is not reached for 1-2 days. The cured composite withstands mechanical shock and twisting forces without bond rupture.
The above Examples are for the purpose of illustration only and are not intended to imply any necessary limitation on the inherent scope of the invention. It will be appreciated that many minor modifications to, or variations in, the formulations and processes descibed above could be made without departing from the essential scope of the invention.
t is intended that all such modifications and variations should be embraced within the purview of this invention.
Claims (27)
1. A process for the polymerization of a non-air-curing mono-ethylenically unsaturated free-radical-poly-merizable monomer which comprises:
(A) incorporating into the monomer an oxidative prepolymerizate of an oxidatively polymerizable compound having a structure comprising at least two unsaturations which are each .beta. , .gamma. to oxygen or sulfur activating the unsaturations towards oxidative polymerization, to provide a concentration of from about 1 to about 200 parts by weight of oxidative prepolymerizate per mole of non-air-curing monomer, the oxidatively polymerizable compound being represented by the structure:
where R1 is a radical characterized by a molecular weight less than about 2000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the functionality of R1 is n, and is in the range of 1 to 10, where R2 is selected from the group consisting of hydrogen and C1 to C10 organic radicals, where E is a moiety containing a radical having an activated olefinic unsaturation .beta. , .gamma. to the activating group and is present in sufficient amount to provide a .beta. , .gamma.
-unsaturation equivalent of less than about 250, where m is the average number of E moieties in the n segments of the structure and where the product of m and n is in the range of about 4 to about 60; and in which the non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer is a (meth)-acrylic ester containing from 4 to 14 carbon atoms; and (B) activating the oxidative prepolymerizate to copolymerize with the non-air-curing monomer.
(A) incorporating into the monomer an oxidative prepolymerizate of an oxidatively polymerizable compound having a structure comprising at least two unsaturations which are each .beta. , .gamma. to oxygen or sulfur activating the unsaturations towards oxidative polymerization, to provide a concentration of from about 1 to about 200 parts by weight of oxidative prepolymerizate per mole of non-air-curing monomer, the oxidatively polymerizable compound being represented by the structure:
where R1 is a radical characterized by a molecular weight less than about 2000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the functionality of R1 is n, and is in the range of 1 to 10, where R2 is selected from the group consisting of hydrogen and C1 to C10 organic radicals, where E is a moiety containing a radical having an activated olefinic unsaturation .beta. , .gamma. to the activating group and is present in sufficient amount to provide a .beta. , .gamma.
-unsaturation equivalent of less than about 250, where m is the average number of E moieties in the n segments of the structure and where the product of m and n is in the range of about 4 to about 60; and in which the non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer is a (meth)-acrylic ester containing from 4 to 14 carbon atoms; and (B) activating the oxidative prepolymerizate to copolymerize with the non-air-curing monomer.
2. The process according to claim 1 in which the oxidatively polymerizable compound has a .beta. , .gamma.
-unsaturation equivalent less than about 150 and is the reaction product of water or an alcohol with allyl glycidyl ether.
-unsaturation equivalent less than about 150 and is the reaction product of water or an alcohol with allyl glycidyl ether.
3. The process according to claim 1 in which the oxidatively polymerizable compound has a structure comprising at least two groups with the formula -Q-CH2-CH=CH2 wherein Q is selected from the group consisting of -O-, -S- and .
4. The process according to claim 1 in which the concentration of oxidative prepolymerizate is in the range of 5 to 100 parts by weight per mole of the monomer.
5. The process according to claim 1 in which the concentration of oxidative prepolymerizate is in the range of about 10 to about 50 parts by weight per mole of the monomer.
6. The process according to claim 1 in which up to 1% by weight of a metallic drier salt is added to the composition to initiate free-radical polymerization.
7. The process according to claim 1 in which the copolymerization takes place under an oxygen free atmosphere.
8. A process for the polymerization of a non-air-curing mono-ethylenically-unsaturated free-radical-polymerizable monomer which comprises:
(A) forming an oxidative prepolymerizate by bringing into contact with air the reaction product of an alcohol and allyl glycidyl ether comprising at least four (4) allyloxy groups per hydroxy group of the alcohol.
(B) adding the non-air-curing free-radical-polymerizable monomer to the oxidative prepolymerizate to provide a concentration of oxidative prepolymerizate of 10 to 50 parts by weight per mole of non-air-curing monomer; and (C) activating the oxidative prepolymerizate toward free-radical copolymerization with the non-air-curing free-radical polymerizable monomer by means of a cobalt drier salt.
(A) forming an oxidative prepolymerizate by bringing into contact with air the reaction product of an alcohol and allyl glycidyl ether comprising at least four (4) allyloxy groups per hydroxy group of the alcohol.
(B) adding the non-air-curing free-radical-polymerizable monomer to the oxidative prepolymerizate to provide a concentration of oxidative prepolymerizate of 10 to 50 parts by weight per mole of non-air-curing monomer; and (C) activating the oxidative prepolymerizate toward free-radical copolymerization with the non-air-curing free-radical polymerizable monomer by means of a cobalt drier salt.
9. The process according to claim 1 in which the oxidatively polymerizable molecule comprises a structure resulting from the oxidation of a prepolymer precursor having the formula:
wherein A is a moiety terminating in the residue of an active hydrogen-containing group selected from the group consisting of alcoholic hydroxyl, thiol, amide, carboxylic acid and secondary amine with an active hydrogen atom removed, E is a moiety containing a radical having an activating olefinic unsaturation .beta. , .gamma. to the activating group, and m and n are integers and where either is less than 4 the other is at least 4.
wherein A is a moiety terminating in the residue of an active hydrogen-containing group selected from the group consisting of alcoholic hydroxyl, thiol, amide, carboxylic acid and secondary amine with an active hydrogen atom removed, E is a moiety containing a radical having an activating olefinic unsaturation .beta. , .gamma. to the activating group, and m and n are integers and where either is less than 4 the other is at least 4.
10. A copolymer produced by the process according to claim 1, 2 or 3.
11. A copolymer produced by the process according to Claim 4, 5 or 6.
12. A copolymer produced by the process according to claim 7, 8 or 9.
13. A composition of matter comprising:
(A) an oxidative prepolymerizate of an oxidatively polymerizable compound having a structure comprising at least two unsaturations which are each .beta. , .gamma. to oxygen or sulfur activating the unsaturations towards oxidative polymerization, the oxidatively polymerizable compound being represented by the structure:
where R1 is characterized as being a radical of molecular weight less than about 2,000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the functionality of R1 is n and is in the range of 1 to 10, where R2 is selected from the group consisting of hydrogen and C1 to C10 organic radicals, where E is a moiety containing a radical having an activated olefinic unsaturation .beta. , .gamma. to the activating group and is present in sufficient amount to provide a .beta. , .gamma.
-unsaturation equivalent of less than about 250, where m is the average number of E moieties in the n segments of the structure and where the product of m and n is in the range of about 4 to about 60;
(B) a non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer; wherein the concentration of oxidative prepolymerizate is in the range of about 1 to about 200 parts by weight per mole of non-air-curing monomer;
and wherein the non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer is a (meth)-acrylic ester containing from 4 to 14 carbon atoms.
(A) an oxidative prepolymerizate of an oxidatively polymerizable compound having a structure comprising at least two unsaturations which are each .beta. , .gamma. to oxygen or sulfur activating the unsaturations towards oxidative polymerization, the oxidatively polymerizable compound being represented by the structure:
where R1 is characterized as being a radical of molecular weight less than about 2,000, obtained by removal of active hydrogen from an active hydrogen compound selected from the group consisting of water, alcohols, thiols, carboxylic acids, carboxylic amides, and amines, where the functionality of R1 is n and is in the range of 1 to 10, where R2 is selected from the group consisting of hydrogen and C1 to C10 organic radicals, where E is a moiety containing a radical having an activated olefinic unsaturation .beta. , .gamma. to the activating group and is present in sufficient amount to provide a .beta. , .gamma.
-unsaturation equivalent of less than about 250, where m is the average number of E moieties in the n segments of the structure and where the product of m and n is in the range of about 4 to about 60;
(B) a non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer; wherein the concentration of oxidative prepolymerizate is in the range of about 1 to about 200 parts by weight per mole of non-air-curing monomer;
and wherein the non-air-curing mono-ethylenically unsaturated free-radical-polymerizable monomer is a (meth)-acrylic ester containing from 4 to 14 carbon atoms.
14. The composition of claim 13 wherein the oxidatively polymerizable compound has a .beta. , .gamma.-unsaturation equivalent of less than about 150 and is the reaction product of water or an alcohol with allyl glycidyl ether.
15. The composition of claim 13 wherein the oxidatively polymerizable compound has a structure comprising at least two groups with the formula -Q-CH2-CH=CH2 wherein Q is selected from the group consisting of -O-, -S- and
16. The composition of claim 13 wherein the .beta. ,.gamma. -un-saturation equivalent is less than about 150.
17. The composition of claim 13 wherein the .beta. ,.gamma. -un-saturation equivalent is in the range of about 115 to about 120.
18. The composition of claim 13 wherein the peroxide content of the oxidative prepolymerizate is in the range of about 0.005 to about 2.0 millimoles per gram.
19. The composition of claim 13 wherein the peroxide content of the oxidative prepolymerizate is in the range of about 0.2 to about 1.0 millimoles per gram.
20. The composition of claim 13 wherein the concentration of oxidative prepolymerizate is in the range of 5 to 100 parts by weight per mole of non-air-curing monomer.
21. The composition of claim 13 in which up to 1% by weight of a metallic drier salt is added to the composition to initiate free-radical-polymerization.
22. The composition of claim 13 in which the concentration of oxidative prepolymerizate is in the range of 10 to 50 parts by weight per mole of non-air-curing monomer.
23. The composition of claim 13 wherein the oxidatively polymerizable compound is represented by the structure:
wherein A is a moiety terminating in the residue of an active hydrogen-containing group selected from the group consisting of alcoholic hydroxyl, thiol, amide, carboxylic acid and secondary amine with an active hydrogen atom removed, E is a moiety containing a radical having an activating olefinic unsaturation .beta. , .gamma. to the activating group, and m and n are integers and where either is less than 4 the other is at least 4.
wherein A is a moiety terminating in the residue of an active hydrogen-containing group selected from the group consisting of alcoholic hydroxyl, thiol, amide, carboxylic acid and secondary amine with an active hydrogen atom removed, E is a moiety containing a radical having an activating olefinic unsaturation .beta. , .gamma. to the activating group, and m and n are integers and where either is less than 4 the other is at least 4.
24. The copolymer product obtained by curing the composition of claim 13, 14 or 15.
25. The copolymer product obtained by curing the composition of claim 16, 17 or 18.
26. The copolymer product obtained by curing the composition of claim 19, 20 or 21.
27. The copolymer product obtained by curing the composition of claim 22 or 23.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US47407983A | 1983-03-10 | 1983-03-10 | |
| US474,079 | 1983-03-10 | ||
| US51287783A | 1983-07-12 | 1983-07-12 | |
| US512,877 | 1983-07-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1216390A true CA1216390A (en) | 1987-01-06 |
Family
ID=27044344
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000443967A Expired CA1216390A (en) | 1983-03-10 | 1983-12-21 | Ethylenically unsaturated polymerizable compositions |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1216390A (en) |
-
1983
- 1983-12-21 CA CA000443967A patent/CA1216390A/en not_active Expired
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