Compositions: coating or plastic – Coating or plastic compositions – Inorganic settable ingredient containing
Reexamination Certificate
2002-05-14
2004-03-23
Marcantoni, Paul (Department: 1755)
Compositions: coating or plastic
Coating or plastic compositions
Inorganic settable ingredient containing
C106S725000, C106S726000, C106S727000, C106S728000, C106S730000, C106S734000, C106S772000, C106S802000, C106S805000, C106S808000, C106S809000, C106S810000, C106S817000, C427S427000
Reexamination Certificate
active
06709508
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to dry mortar formulations modified with water-redispersible polymer powders which exhibit improved tensile adhesion properties when used as adhesives and coating materials.
2. Background Art
Mixtures of hydraulic binder such as cement or gypsum, and water-redispersible polymer powders are known. The redispersible powder is added as an organic binder to improve adhesion to the substrate and the flexibility of the coating. Further ingredients of these mixtures include fillers, as well as thickeners for controlling the Theological properties. Conventional additives also include dispersants, cement plasticizers, and additives for accelerating or retarding setting. One example of a mortar base mix is disclosed in DE-A 1951171.
Such mixtures are prepared by stirring with water and then used, for example, in construction adhesives such as tile adhesives or exterior insulation and finishing system (EIFS) adhesives, troweling compositions, leveling compounds, grouts, reinforcing mortars for exterior insulation and finishing systems (EIFS), and as adhesives for bonding wood flooring. When such mortar compounds are employed, a disadvantage is that the tensile bond strengths obtained are not entirely satisfactory. In particular, a decrease in the tensile bond strength is often found when the dry mortars have been stored for prolonged periods prior to use.
DE-A 19843730 and EP-B 751175 disclose that polymer powders can be prevented from self-igniting by adding antioxidants.
It would be desirable to provide dry mortar formulations which when used as adhesives or coating materials bring about good tensile bond strength.
SUMMARY OF THE INVENTION
The present invention is directed to dry mortar compositions employing water-redispersible polymer powders which produced cured (set) products exhibiting good tensile bond strength irrespective of dry storage time. The compositions contain, in addition to the conventional mortar components, a redispersible polymer powder and an antioxidant.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
The invention provides dry mortar formulations comprising
a) from 0.5 to 80% by weight of hydraulic binder,
b) from 0 to 97% by weight of fillers,
c) from 0 to 3.5% by weight of thickeners,
d) from 1.0 to 80% by weight of redispersible polymer powder, and
e) from 0.0001 to 1.0% by weight of one or more antioxidant compounds,
the percentage by weight based on the overall weight of the dry mortar, and totaling 100% by weight. The descriptions of the various ingredients set forth below are non-limiting.
The hydraulic binder fraction a) is preferably from 0.5 to 70% by weight, with particular preference given to 8 to 50% by weight. Generally, cement or gypsum is used. Preference is given to using Portland cement.
Suitable fillers b) are quartz sand, quartz flour, calcium carbonate, dolomite, aluminum silicates, talc, and mica; lightweight fillers such as pumice, foamed glass, aerated concrete, perlites or vermiculites; and fillers based on natural or synthetic fibers. Mixtures of these fillers may also be used. The filler fraction is preferably from 10 to 90% by weight, more preferably from 40 to 90% by weight, and most preferably from 75 to 90% by weight.
Examples of thickeners c) are polysaccharides such as cellulose ethers and modified cellulose ethers, starch ethers, guar gum, xanthan gum, phyllosilicates, polycarboxylic acids such as polyacrylic acid and the partial esters thereof, optionally acetalized and/or hydrophobically modified polyvinyl alcohols, casein, and associative thickeners. It is also possible to use mixtures of these thickeners. Preference is given to cellulose ethers, modified cellulose ethers, optionally acetalized and/or hydrophobically modified polyvinyl alcohols, and mixtures thereof. It is preferred to use from 0.05 to 2.5% by weight, more preferably from 0.05 to 0.8% by weight of thickeners.
Water-redispersible polymer powders d) are those which in water break down into primary particles, which are then dispersed in the water. Suitable polymers, for example, are those based on one or more vinyl esters of unbranched or branched alkylcarboxylic acids having from 1 to 15 carbon atoms, methacrylic esters and acrylic esters of alcohols having from 1 to 10 carbon atoms, vinyl-aromatics, olefins, dienes, and vinyl halides as monomers or comonomers. It is also possible to use mixtures of these polymers. Preference is given to using from 1 to 10% by weight of water-redispersible polymer powders d).
Preferred vinyl esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methylvinyl acetate, vinyl pivalate, and vinyl esters of alpha-branched monocarboxylic acids having from 5 to 11 carbon atoms, examples being VeoVa5®, VeoVa9®, VeoVa10® or VeoVa11® (trade names of Shell). Preferred methacrylic esters or acrylic esters are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, and 2-ethylhexyl acrylate. Preferred vinyl-aromatics are styrene, methylstyrene, and vinyltoluene. A preferred vinyl halide is vinyl chloride. The preferred olefins are ethylene and propylene, and the preferred dienes are 1,3-butadiene and isoprene.
If desired, the polymers may also contain from 0.1 to 10% by weight, based on the overall weight of the polymer, of functional comonomer units, for example ethylenically unsaturated monocarboxylic or dicarboxylic acids such as acrylic acid; ethylenically unsaturated carboxamides such as (meth)acrylamide; ethylenically unsaturated sulfonic acids and/or their salts, preferably vinylsulfonic acid; polyethylenically unsaturated comonomers such as divinyl adipate, diallyl maleate, allyl methacrylate and triallyl cyanurate, and/or N-methylol(meth)acrylamides and their ethers, such as their isobutoxy or n-butoxy ethers.
Particularly preferred polymers are those listed below, the weight percentages adding up to 100% by weight, together, where appropriate, with the fraction of functional comonomer units:
From among the vinyl ester polymers: vinyl acetate polymers, vinyl acetate-ethylene copolymers with an ethylene content of from 1 to 60% by weight; vinyl ester-ethylene-vinyl chloride copolymers with an ethylene content of from 1 to 40% by weight and a vinyl chloride content of from 20 to 90% by weight; vinyl acetate copolymers with from 1 to 50% by weight of one or more copolymerizable vinyl esters such as vinyl laurate, vinyl pivalate, vinyl esters of an alpha-branched carboxylic acid, especially Versatic acid vinyl esters (VeoVa9®, VeoVa10®, VeoVa11®), which may also contain from 1 to 40% by weight of ethylene; and vinyl acetate-acrylic ester copolymers with from 1 to 60% by weight of acrylic ester, especially methyl methacrylate, n-butyl acrylate, or 2-ethylhexyl acrylate, which may also contain from 1 to 40% by weight of ethylene.
From among the (meth)acrylic ester polymers: polymers of n-butyl acrylate or 2-ethylhexyl acrylate; copolymers of methyl methacrylate with n-butyl acrylate and/or 2-ethylhexyl acrylate; and copolymers of methyl methacrylate with 1,3-butadiene.
From among the vinyl chloride polymers, besides the abovementioned vinyl ester/vinyl chloride/ethylene copolymers: vinyl chloride-ethylene copolymers and vinyl chloride-acrylate copolymers.
From among the styrene polymers: styrene-1,3-butadiene copolymers and styrene-acrylic ester copolymers such as styrene-n-butyl acrylate or styrene-2-ethylhexyl acrylate copolymers, each with a styrene content of from 10 to 70% by weight. Most preferred are styrene-1,3-butadiene copolymers having a styrene content of from 10 to 70% by weight and a 1,3-butadiene content of from 30 to 90% by weight, with or without the abovementioned functional comonomer units, the fractions in % by weight adding up to 100% by weight.
Aqueous polymer dispersions and the water-redispersible powders of the abovementioned polymers that are obtainable from them by drying are known and are avai
Dietrich Ulf
Mayer Theo
Brooks & Kushman P.C.
Marcantoni Paul
Wacker Polymer Systems GmbH & Co. KG
LandOfFree
Dry mortar formulations modified with water-redispersible... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dry mortar formulations modified with water-redispersible..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dry mortar formulations modified with water-redispersible... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3234939