Primer compositions and methods of making the same
In one aspect, the invention includes an aqueous composition for coating articles including isocyanate resins. The coating composition includes from about 50% to about 100% by weight of at least one thermoplastic acrylic polymer; from about 0.1% to about 20% by weight titanium dioxide; and water. The composition has a basic pH, a solids ratio of from about 58% to about 69% by weight, and is substantially free of quartz pigments.
1 . An aqueous composition for coating articles including isocyanate resins, the composition comprising:
from about 50% and to about 100% by weight of at least one thermoplastic acrylic polymer;
from about 0.1% and to about 20% by weight titanium dioxide; and
water, wherein the composition has a basic pH, a solids ratio of from about 58% to about 69% by weight, and is substantially free of quartz pigments.
2 . The composition according to claim 1 , wherein the acrylic polymer is present in an amount from about 10% to about 40% by weight.
3 . The composition according to claim 1 , wherein the acrylic polymer comprises an acrylic copolymer.
4 . The composition according to claim 1 , wherein the acrylic polymer comprises monomer units selected from the group consisting of acrylic acid, butyl acrylate, 2-ethylhexyl acrylate, methyl acrylate, ethyl acrylate, acrylonitrile, methyl methacrylate, trimethylolpropane triacrylate, and combinations thereof.
5 . The composition according to claim 4 , wherein the acrylic polymer further comprises monomer units selected from the group consisting of vinyl aromatics and combinations thereof.
6 . The composition according to claim 5 , wherein the vinyl aromatic monomer groups are selected from the group consisting of styrene, α-methyl styrene, p-methyl styrene, o-methyl styrene, p-tert-butyl styrene, 1,3-dimethylstyrene, 1,3-butadiene, 2,4-butadiene, and combinations thereof.
7 . The composition according to claim 1 , wherein the titanium dioxide is present in an amount of from about 0.5% to about 5% by weight.
8 . The composition according to claim 1 , further comprising from about 1% to about 30% by weight thickening agents.
9 . The composition according to claim 8 , wherein the thickening agents are selected from the group consisting of clay, aluminum silicate, clays, magnesium silicates, and combinations thereof.
10 . The composition according to claim 1 , further comprising at least one additional component selected from the group consisting of surfactants, dispersants, organic solvents, fungicides, bactericides, catalysts, rheological agents, extenders, biocides, pH stabilizers and combinations thereof.
11 . The composition according to claim 1 , further comprising a pigment.
12 . The composition according to claim 11 , wherein the composition comprises a pigment volume concentration load of from about 30% to about 40%.
13 . A method for making a primer composition, the method comprising:
forming a first grind phase by grinding water, at least one surfactant, and at least one co-solvent together;
forming a second grind phase by grinding titanium dioxide into the first grind phase;
grinding the second grind phase to form a paste having a Hegman of no greater than about 4; and
adding the paste to a let-down composition comprising water, at least one acrylic polymer, and at least one rheological agent while agitating.
14 . The method according to claim 13 , further comprising grinding thickening agents during the formation of the second grind phase.
15 . The method according to claim 13 , further comprising grinding extenders during the formation of the second grind phase.
16 . The method according to claim 13 , wherein the paste comprises particles having an average diameter of from about 5 μm to about 8 μm.
17 . The method according to claim 13 , wherein the step of adding the paste to a let-down composition comprises adding the paste at substantially ambient conditions.
18 . The method according to claim 13 , further comprising cooling the paste to a temperature below about 100° F. before adding the paste to the let-down composition.
19 . The method according to claim 13 , further comprising adding at least one catalyst to the let-down composition.
20 . The method according to claim 13 , wherein at least one pigment is added to the composition during formation of the second grind phase.
21 . The method according to claim 13 , wherein the let-down composition includes a sufficient concentration of water to form a primer having a pigment volume concentration from about 30% to about 40%.
22 . A method of producing a thin-layer lignocellulosic composite having increased resistance to moisture-induced shrinking or swelling, the method comprising:
(a) forming a lignocellulosic composite mixture comprising at least one type of lignocellulosic fiber comprising a predetermined moisture content of at least about 4%, at least about 1 wt % of an organic isocyanate resin, at least about 0.1 wt % tackifier, and at least about 0.1 wt % release agent, wherein the mixture is substantially free of wax;
(b) pre-pressing the mixture into a loose formed mat;
(c) pressing the mat between two dies at an elevated temperature and pressure and for a sufficient time further reducing the thickness of the mat to form a thin-layer composite of predetermined thickness, and allowing the isocyanate resin to interact with the lignocellulosic fiber such that the resultant thin-layer composite has a predetermined resistance to moisture; and
(d) coating at least one surface of the thin-layer lignocellulosic composite with a primer comprising:
(i) from about 50% to about 100% by weight of at least one thermoplastic acrylic polymer;
(ii) from about 0.1% and about 20% by weight titanium dioxide; and
(iii) water, wherein the composition has a basic pH, a solids ratio of from about 58% to about 69% by weight, and is substantially free of quartz pigments.
23 . The method according to claim 22 , wherein the lignocellulosic fiber comprises wood.
24 . The method according to claim 22 , wherein the tackifier is selected from the group consisting of rosins, lignins, hydrocarbons, hydrogenated hydrocarbons, pure monomers, hydrogenated pure monomers, water-based dispersions, and combinations thereof.
25 . The method according to claim 22 , further comprising spraying additional release agent onto the loose-formed mat before the pressing step.
26 . The method according to claim 22 , wherein the release agent is added to the mixture prior to pre-pressing the mixture into a loose formed mat.
27 . The method according to claim 22 , wherein the release agent will not substantially interfere with subsequent processing of the composite.
28 . The method according to claim 22 , further comprising exposing at least one surface of at least one die to an anti-bonding agent.
29 . The method according to claim 28 , wherein the step of exposing the at least one surface of the at least one die to the anti-bonding agent comprises coating the at least one surface of the at least one die with the anti-bonding agent.
30 . The method according to claim 22 , wherein the isocyanate comprises diphenylmethane diisocyanate (MDI) or toluene diisocyanate (TDI).
31 . The method according to claim 22 wherein the temperature used to press the mat into the thin layer composite comprises a range from about 250° F. (about 121° C.) to about 400° F. (about 204° C.).
32 . The method according to claim 22 , wherein the pressure used to press the mat into the thin layer composite comprises a range from about 2500 psi (about 176 kg/cm 2 ) to about 150 psi (10.5 kg/cm 2 ).
33 . The method according to claim 22 , wherein the predetermined resistance to moisture comprises a thickness swelling of less than 15% after being immersed for 24 hours in water at 70° F. (21° C.).
34 . The method according to claim 22 , wherein the acrylic polymer in the primer composition is present in an amount of from about 15% to about 35% by weight.
35 . The method according to claim 22 , wherein the acrylic polymer comprises an acrylic copolymer.
36 . The method according to claim 22 , wherein the acrylic polymer contains monomer units selected from the group consisting of be acrylic acid, butyl acrylate, 2-ethylhexyl acrylate, methyl acrylate, ethyl acrylate, acrylonitrile, methyl methacrylate, trimethylolpropane triacrylate, and combinations thereof.
37 . The method according to claim 36 , wherein the acrylic polymer further comprises monomer units selected from the group consisting of vinyl aromatics and combinations thereof.
38 . The method according to claim 37 , wherein the vinyl aromatic monomer groups are styrene.
39 . The method according to claim 22 , wherein the titanium dioxide is present in an amount of from about 0.5% to about 5% by weight.
40 . The method according to claim 22 , further comprising from about 1% to about 30% by weight thickening agents.
41 . The method according to claim 40 , wherein the thickening agents are selected from the group consisting of clay, aluminum silicate, clays, magnesium silicates, and combinations thereof.
42 . The method according to claim 22 , further comprising at least one additional component selected from the group consisting of surfactants, dispersants, organic solvents, fungicides, bactericides, catalysts, rheological agents, extenders, biocides, and combinations thereof.
43 . The method according to claim 22 , further comprising a pigment.
44 . The method according to claim 43 , wherein the composition comprises a pigment volume concentration load of from about 30% to about 40%.
45 . A thin-layer lignocellulosic composite comprising a mixture of no more than about 99 wt % of at least one type of lignocellulosic fiber, wherein the fiber comprises a predetermined moisture content of at least about 4%, at least about 1 wt % of an organic isocyanate resin, a release agent, and a tackifier, wherein the mixture is substantially free of added wax and wherein the mixture is pressed between two dies at an elevated temperature and pressure and for a sufficient time forming a thin-layer composite of predetermined thickness, and allowing the isocyanate resin to interact with the lignocellulosic fiber such that the resultant thin-layer composite has a predetermined resistance to moisture, and wherein the thin-layer lignocellulosic composite is coated with a primer composition comprising:
(a) from about 10% to about 40% by weight of at least one thermoplastic acrylic polymer;
(b) from about 0.1% to about 20% by weight titanium dioxide; and
(c) water, wherein the primer composition has a basic pH, a solids ratio of from about 58% to about 69% by weight, and is substantially free of quartz pigments.
46 . The thin-layer lignocellulosic composite according to claim 45 , wherein the lignocellulosic fiber comprises wood.
47 . The thin-layer lignocellulosic composite according to claim 45 , wherein the mixture comprises from about 0.1% to about 5 wt % tackifier.
48 . The thin-layer lignocellulosic composite according to claim 45 , wherein the tackifier is selected from the group consisting of rosins, lignins, hydrogenated rosins, hydrocarbons, hydrogenated hydrocarbons, pure monomers, hydrogenated pure monomers, water-based dispersions, and combinations thereof.
49 . The thin-layer lignocellulosic composite according to claim 45 , wherein the release agent comprises an emulsion of surfactants and polymers.
50 . The thin-layer lignocellulosic composite according to claim 49 , wherein the mixture is preformed into a loose formed mat, and additional release agent is sprayed onto at least one surface of the mat prior to pressing the mat into the thin layer composite.
51 . The thin-layer lignocellulosic composite according to claim 45 , wherein the lignocellulosic fiber ranges from about 80% to about 98 wt % of the mixture.
52 . The thin-layer lignocellulosic composite according to claim 51 , wherein the predetermined moisture content of the fiber ranges from about 4% to about 15% moisture by weight after drying.
53 . The thin-layer lignocellulosic composite according to claim 45 , wherein the isocyanate comprises diphenylmethane diisocyanate or toluene diisocyanate.
54 . The thin-layer lignocellulosic composite according to claim 45 , wherein the predetermined thickness ranges from about 0.085 inches (about 2.16 mm) to about 0.250 inches (about 6.35 mm).
55 . The thin-layer composite according to claim 45 , wherein the acrylic polymer in the primer composition is present in an amount of from about 15% to about 35% by weight.
56 . The thin-layer composite according to claim 45 , wherein the acrylic polymer comprises an acrylic copolymer.
57 . The thin-layer composite according to claim 45 , wherein the acrylic polymer contains monomer units selected from the group consisting of be acrylic acid, butyl acrylate, 2-ethylhexyl acrylate, methyl acrylate, ethyl acrylate, acrylonitrile, methyl methacrylate, trimethylolpropane triacrylate, and combinations thereof.
58 . The thin-layer composite according to claim 57 , wherein the acrylic polymer further comprises monomer units selected from the group consisting of vinyl aromatics and combinations thereof.
59 . The thin-layer composite according to claim 58 , wherein the vinyl aromatic monomer groups are styrene.
60 . The thin-layer composite according to claim 45 , wherein the titanium dioxide is present in an amount of from about 0.5% to about 5% by weight.
61 . The thin-layer composite according to claim 45 , further comprising from about 1% to about 30% by weight thickening agents.
62 . The thin-layer composite according to claim 61 , wherein the thickening agents are selected from the group consisting of clay, aluminum silicate, clays, magnesium silicates, and combinations thereof.
63 . The thin-layer composite according to claim 45 , further comprising at least one additional component selected from the group consisting of surfactants, dispersants, organic solvents, fungicides, bactericides, catalysts, rheological agents, extenders, biocides, and combinations thereof.
64 . The thin-layer composite according to claim 45 , further comprising a pigment.
65 . The composition according to claim 64 , wherein the composition comprises a pigment volume concentration load of from about 30% to about 40%.