Anaerobic compositions and surface activator therefor

A two-part polymerizable composition, curable through gaps of twenty mils or more, consisting essentially of:

• A. a first part comprising a mixture of a polymerizable acrylate ester monomer selected from the group consisting of monofunctional acrylate esters and polyacrylate esters having the formula ##EQU14## wherein R.sup.2 is a radical selected from the group consisting of hydrogen, halogen and alkyl of from 1 to about 4 carbon atoms;
• q is an integer equal to at least 1;
• and X is an organic radical containing at least two carbon atoms and having a total bonding capacity of q plus 1;
• and a hydroperoxy polymerization initiator capable of polymerizing said monomer in the substantial absence of oxygen;
• B. as a cure-through-gap agent a second part comprising the combination of a substituted thiourea of the formula ##EQU15## wherein A is hydrogen or ##EQU16## and C. about 0.1% to about 5% by weight of the composition of an acid having a pKA of less than about 6 in admixture with either (A) or (B).

A two-part polymerizable composition, curable through gaps of 20 mils or more, consisting essentially of:

• A. a first part comprising a polymerizable acrylate ester monomer having a molecular weight of at least about 130 and selected from the group consisting of monofunctional acrylate esters and polyacrylate esters having the formula ##EQU20## wherein R.sup.2 is a radical selected from the group consisting of hydrogen, halogen and alkyl of from 1 to about 4 carbon atoms;
• q is an integer equal to at least 1;
• and X is an organic radical containing at least two carbon atoms and having a total bonding capacity of q plus 1;
• from about 0.1% to about 10% by weight of a hydroperoxide polymerization initiator capable of polymerizing said monomer in the substantial absence of oxygen;
• and
• B. as a cure-through-gap agent a second part comprising the combination of a solvent solution of a substituted thiourea having one of the formulae;
• a. ##EQU21## wherein each of R.sup.6, R.sup.7 and R.sup.8 is a hydrocarbon group containing up to about 10 carbon atoms, and R.sup.5 is hydrogen or R.sup.8 ;
• b. ##EQU22## where each B is a difunctional chain completing a heterocyclic ring containing up to about 14 carbon atoms;
• and
• c. ##EQU23## wherein R.sup.5, R.sup.8 and B are as defined above, and about 0.1% to about 5% by weight of the composition of an acid having a pKA of less than about 6.

A process for sealing or bonding substrates which comprises:

• A. applying to at least one of said substrates a primer composition, capable of curing the composition of part (B) through gaps of twenty mils or more, comprising a mixture of a substituted thiourea of the formula ##EQU24## wherein A is hydrogen or ##EQU25## and about 0.1% to about 5% of an organic acid having a pKA less than about 6;
• B. applying to at least one of said substrates a polymerizable composition comprising a polymerizable acrylate ester monomer selected from the group consisting of monofunctional acrylate esters and polyacrylate esters having the formula ##EQU26## wherein R.sup.2 is a radical selected from the group consisting of hydrogen, halogen and alkyl of from 1 to about 4 carbon atoms;
• q is an integer equal to at least 1;
• and X is an organic radical containing at least two carbon atoms and having a total bonding capacity of q plus 1;
• and from about 0.1% to about 10% by weight of a hydroperoxide polymerization initiator capable of polymerizing said monomer in the substantial absence of oxygen;
• C. and thereafter placing said substrates in an abutting relationship until the polymerizable composition has hardened sufficiently to seal or bond said substrates.

A process for sealing or bonding substrates which comprises:

• A. applying to at least one of said substrates a primer composition, capable of curing the composition of part (B) through gaps of 20 mils or more, comprising a mixture of a substituted thiourea of the formula ##EQU30## wherein A is hydrogen or ##EQU31## B. applying to at least one of said substrates a polymerization composition comprising a polymerizable acrylate ester monomer selected from the group consisting of monofunctional acrylate esters and polyacrylate esters having the formula ##EQU32## wherein R.sup.2 is a radical selected from the group consisting of hydrogen, halogen and alkyl of from 1 to about 4 carbon atoms;
• q is an integer equal to at least 1;
• and X is an organic radical containing at least two carbon atoms and having a total bonding capacity of q plus 1;
• from about 0.1% to about 10% by weight of a hydroperoxide polymerization initiator capable of polymerizing said monomer in the substantial absence of oxygen;
• and about 0.1% to about 5% of an organic acid having a pKA less than about 6;
• C. and thereafter placing said substrates in an abutting relationship until the polymerizable composition has hardened sufficiently to seal or bond said substrates.