Compositions: coating or plastic – Coating or plastic compositions – Inorganic settable ingredient containing
Reexamination Certificate
2000-09-13
2002-06-04
Green, Anthony (Department: 1755)
Compositions: coating or plastic
Coating or plastic compositions
Inorganic settable ingredient containing
C106S634000, C106S696000, C106S708000, C106S724000, C106S790000, C106S823000
Reexamination Certificate
active
06398865
ABSTRACT:
BACKGROUND OF INVENTION
The present invention relates to a cement composition containing a silicone oil emulsion and more specifically to a cement composition having superior fluidity and exhibiting superior water repellency and resistance to cracking upon hardening. Cement compositions obtained by compounding silicone oil with hydraulic cement, KOKAI Hei 02-145467, KOKAI Hei 02-160651, and KOKAI Hei 03-261642, and a concrete or mortar composition, KOKAI Hei 05-306156 have been offered in order to obtain water-repellent cured products. However, the problem with cement composition obtained by compounding silicone oil in these compositions was that it was difficult to disperse silicone oil in hydraulic cement and the water repellent properties of the resultant cured cement products were insufficient. In addition, the problem with cement compositions obtained by compounding silicone rubber powder therein was that they lacked fluidity and the water repellent properties and resistance to cracking of the cured products of concrete or mortar obtained by curing them were insufficient. It is an object of the present invention to provide a cement composition having superior fluidity and exhibiting superior water repellency and resistance to cracking upon hardening.
SUMMARY OF INVENTION
The present invention is a cement composition comprising
(A) hydraulic cement,
(B) a silicone oil emulsion containing crosslinked silicone particles with an average particle size of from 0.05 &mgr;m to 100 &mgr;m in drops of silicone oil with an average size of 0.1 &mgr;m to 500 &mgr;m dispersed in water, the particle size of the crosslinked silicone particles being smaller than the size of the silicone oil drops, in an amount such that the total weight of the silicone oil and crosslinked silicone particles in component (B) ranges from 0.1 parts by weight to 50 parts by weight per 100 parts by weight of component (A), and optionally
(C) aggregate.
DESCRIPTION OF INVENTION
The present invention is a cement composition comprising
(A) hydraulic cement,
(B) a silicone oil emulsion containing crosslinked silicone particles with an average particle size of from 0.05 &mgr;m to 100 &mgr;m in drops of silicone oil with an average size of 0.1 &mgr;m to 500 &mgr;m dispersed in water, the particle size of the crosslinked silicone particles being smaller than the size of the silicone oil drops, in an amount such that the total weight of the silicone oil and crosslinked silicone particles in component (B) ranges from 0.1 parts by weight to 50 parts by weight per 100 parts by weight of component (A), and optionally
(C) aggregate.
The cement composition of the present invention is explained in detail hereinbelow. The hydraulic cement of component (A), which is the main component of the present composition, is a component that hardens on standing when mixed with water. A representative example of component (A) is Portland cement, which is prepared, for instance, by adding a cure modifier such as calcium sulfate (gypsum) to a clinker prepared by firing a raw material consisting of iron oxide, quartzite, clay, and lime (CaO) at a high temperature and then pulverizing the mixture. Examples of Portland cement include early strength Portland cement, ultra-high early strength Portland cement, moderate-heat Portland cement, sulfate-resisting Portland cement, and white Portland cement. Additionally, examples of the hydraulic cement of component (A) other than Portland cement include blast furnace cement, silica cement, fly ash cement, and alumina cement.
The silicone oil emulsion of component (B) is a component used to impart superior water repellency and cracking resistance to cured products of the present composition without decreasing the fluidity. The silicone oil emulsion of component (B) is characterized by containing crosslinked silicone particles with an average particle size of from 0.05 &mgr;m to 100 &mgr;m in drops of silicone oil with an average size of 0.1 &mgr;m to 500 &mgr;m dispersed in water, the particle size of the crosslinked silicone particles being smaller than the size of the silicone oil drops.
Silicone oils with a viscosity of from 1 mPa·s to 100,000,000 mPa·s at 25° C. are preferable, and silicone oils with a viscosity of from 2 mPa·s to 10,000,000 mPa·s at 25° C. are particularly preferable as the silicone oil of component (B). Examples of such silicone oils include oils having linear, partially branched linear, cyclic, or branched molecular structures, with oils having linear or cyclic structures being especially preferable. In addition, the silicone oil preferably does not contribute to the crosslinking reaction taking place when the crosslinked silicone particles are formed. Examples of silicone oils suggested in the case where the crosslinked silicone particles are crosslinked by means of a hydrosilylation reaction include compounds that have no alkenyl groups and no silicon-bonded hydrogen atoms, for instance dimethylpolysiloxane having both terminal ends of the molecular chain blocked with trimethylsiloxy groups, methylphenylpolysiloxane having both terminal ends of the molecular chain blocked with trimethylsiloxy groups, copolymer of methylphenylsiloxane and dimethylsiloxane having both terminal ends of the molecular chain blocked with trimethylsiloxy groups, copolymer of methyl(3,3,3-trifluoropropyl)siloxane and dimethylsiloxane having both terminal ends of the molecular chain blocked with trimethylsiloxy groups, cyclic dimethylsiloxane, and cyclic methylphenylsiloxane. Examples of silicone oils suggested in the case where the crosslinked silicone particles are crosslinked by means of a condensation reaction include compounds that have no silanol groups, silicon-bonded hydrogen atoms, or silicon-bonded hydrolyzable groups, for instance, silicone oils such as those mentioned above, and in addition dimethylpolysiloxane having both terminal ends of the molecular chain blocked with dimethylvinylsiloxy groups, copolymer of methylvinylsiloxane and dimethylsiloxane having both terminal ends of the molecular chain blocked with dimethylvinylsiloxy groups, methylvinylpolysiloxane having both terminal ends of the molecular chain blocked with trimethylsiloxy groups, and cyclic methylvinylsiloxane.
In component (B), the average size of the drops of silicone oil ranges from 0.1 &mgr;m to 500 &mgr;m, preferably, from 0.5 &mgr;m to 200 &mgr;m. This is due to the fact that when the average size of the drops of silicone oil is either below the lower limit of the above-mentioned range or exceeds the upper limit of the above-mentioned range, the stability of the emulsion tends to decrease.
In component (B) the average particle size of the crosslinked silicone particles ranges from 0.1 &mgr;m to 100 &mgr;m and preferably from 0.5 &mgr;m to 50 &mgr;m. This is due to the fact that when the average particle size of the crosslinked silicone particles is either below the lower limit of the above-mentioned range or exceeds the upper limit of the above-mentioned range, the stability of the emulsion tends to decrease. In component (B), the particle size of the crosslinked silicone particles must be smaller than the size of the drops of silicone oil. Spherical, spindle-shaped, oblate, or irregular shapes are suggested as examples of the shape of the crosslinked silicone particles, with the spherical shape being preferred.
Compositions crosslinkable by means of a hydrosilylation reaction, a condensation reaction, or a free radical reaction initiated by an organic peroxide are suggested as the crosslinkable silicone compositions used to form the crosslinked silicone particles, with compositions crosslinkable via a hydrosilylation reaction or a condensation reaction being preferred. Such crosslinkable silicone compositions are preferably compositions forming rubber-like or gel-like crosslinked products as a result of the crosslinking reaction.
A composition comprising at least an organopolysiloxane having at least two alkenyl groups in one molecule, an organopolysiloxane having at least two silicon-bonded hydrogen atoms in one
Kobayashi Kazuo
Morita Yoshitsugu
Uomori Masahiko
DeCesare James L.
Dow Corning Toray Silicone Co. Ltd.
Green Anthony
Scaduto Patricia M.
LandOfFree
Cement composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cement composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cement composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2898417