TWO-PART, SILANE MODIFIED POLYMER/FREE RADICALLY CURABLE ADHESIVE SYSTEMS
Two-part silane modified polymer/free radically curable adhesive systems demonstrating improved strength and percent elongation are provided.
1 . A two part adhesive composition comprising:
(a) a Part A composition comprising:
(i) a (meth)acrylate-functionalized component; and
(ii) a block copolymer component; and
(b) a Part B composition comprising:
(i) an alkoxysilane- or acyloxysilane-functionalized component,
wherein the Part A composition or the Part B composition comprises an oxidant and the Part A composition or the Part B composition comprises at least one of a reducing agent and a transition metal, provided that the Part A composition and the Part B composition do not each comprise the oxidant, the reducing agent, and the transition metal.
2 . The composition of claim 1 , wherein the (meth)acrylate-functionalized component (i) of the Part A composition comprises a mono-functional (meth)acrylate component.
3 . The composition of claim 1 , wherein the (meth)acrylate-functionalized component (i) of the Part A composition comprises an alkyl(meth)acrylate and/or a mono-functional (meth)acrylate component and one or more of isobornyl (meth)acrylate, lauryl (meth)acrylate and/or ethylhexyl (meth)acrylate.
4 . The composition of claim 1 , wherein the (meth)acrylate-functionalized component (i) of the Part A composition comprises a mono-functional (meth)acrylate component in an amount within the range of about 10 to about 50 percent by weight.
5 . The composition of claim 1 , wherein the block copolymer component (ii) of the Part A composition comprises one or more of a (meth)acrylate-terminated polybutadiene in liquid form at room temperature, a styrene-containing block copolymer, a core shell rubber, and combinations thereof.
6 . The composition of claim 5 , wherein the styrene-containing block copolymer is a member selected from the group consisting of styrene-butadiene-styrene, styrene-isoprene-styrene, and combinations thereof.
7 . The composition of claim 5 , wherein the styrene-containing block copolymer has a weight average molecular weight in the range of about 100,000 to about 500,000 Mw.
8 . The composition of claim 1 , further comprising a reactive acid component.
9 . The composition of claim 8 , wherein the reactive acid component comprises one or more of a (meth)acrylic acid and/or ester thereof.
10 . The composition of claim 8 , wherein the reactive acid component comprises a phosphate ester of hydroxyethyl methacrylate.
11 . The composition of claim 1 , wherein the oxidant is a peroxide.
12 . The composition of claim 1 , wherein the oxidant is a perbenzoate.
13 . The composition of claim 1 , wherein the oxidant is t-butyl perbenzoate, benzoyl peroxide or cumene hydroperoxide.
14 . The composition of claim 1 , wherein the oxidant is present in an amount from about 0.01 percent to about 10 percent by weight.
15 . The composition of claim 1 , wherein the reducing agent is a nitrogen-containing component and/or a transition metal containing compound.
16 . The composition of claim 1 , wherein the nitrogen containing component is present in an amount from about 0.01 percent to about 10 percent by weight.
17 . The composition of claim 15 , wherein the transition metal of the transition metal containing compound is a member selected from the group consisting of copper, vanadium, cobalt and iron.
18 . The composition of claim 15 , wherein the transition metal containing compound is present in an amount from about 0.005 percent by weight to about 0.5 percent by weight.
19 . The composition of claim 1 , wherein Part A further comprises a reactive acid component.
20 . The composition of claim 1 , wherein the alkoxysilane-or acyloxysilane-functionalized component is a polymer having at least one hydrolysable silyl group that is bonded to the polymer through an ether (—O—) linking group or carbonyl group, in which the carbonyl group is bonded to heteroatoms selected from oxygen, nitrogen and sulfur, with the proviso that at least one heteroatom is nitrogen.
21 . The composition of claim 1 , wherein the alkoxysilane-or acyloxysilane-functionalized component is present in an amount from 30 percent by weight to 95 percent by weight.
22 . The composition of claim 1 , which when mixed together cures to 90% of its ultimate strength in 24 hours at room temperature.
23 . The composition of claim 21 , which when cured demonstrates at least one of tensile strength on aluminum substrates of greater than 2.5 Mpa, linear shrinkage of less than 8%, Shore A hardness of greater than 40, and elongation of greater than 200%.
24 . The composition of claim 1 , further comprising an alkyl (meth)acrylate component.
25 . The composition of claim 24 , wherein the alkyl (meth)acrylate component is selected from the group consisting of polyethylene glycol di(meth)acrylates, tetrahydrofuran (meth)acrylates and di(meth)acrylates, hydroxypropyl (meth)acrylate, hexanediol di(meth)acrylate, trimethylol propane tri(meth)acrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, benzylmethacrylate, tetraethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, di-(pentamethylene glycol) dimethacrylate, tetraethylene diglycol diacrylate, diglycerol tetramethacrylate, tetramethylene dimethacrylate, ethylene dimethacrylate, neopentyl glycol diacrylate, trimethylol propane triacrylate and bisphenol-A mono and di(meth)acrylates, bisphenol-F mono and di(meth)acrylates, urethane (meth)acrylate, epoxy(meth)acrylate, and (meth)acrylated polyacrylate.
26 . The composition of claim 1 , wherein the Part A composition is housed in a first chamber of a dual chamber syringe and the Part B composition is housed in a second chamber of the dual chamber syringe.
27 . The composition of claim 1 , wherein at least one of the Part A composition or the Part B composition further comprises at least one of a toughener, a plasticizer or a filler.
28 . A two part adhesive composition comprising:
(a) a Part A composition comprising:
(i) a (meth)acrylate-functionalized component comprises a mono-functional (meth)acrylate component;
(ii) a (meth)acrylate-functionalized urethane; and
(iii)a block copolymer component; and
(b) a Part B composition comprising:
(i) an alkoxysilane- or acyloxysilane-functionalized component,
wherein the Part A composition or the Part B composition comprises an oxidant and the Part A composition or the Part B composition comprises at least one of a reducing agent and a transition metal, provided that the Part A composition and the Part B composition do not each comprise the oxidant, the reducing agent, and the transition metal.
29 . The composition of claim 28 , which cures in a fixture time on aluminum substrates with a 1 mm gap of about 15 to about 45 minutes and when cured demonstrates at least one of a tensile strength on aluminum substrates of greater than 2.5 MPa, and percent elongation of greater than 100.