摘要:
Moisture curable compositions which cure to produce hard coatings contain prepolymers bearing alkoxysilyl groups of the formula —X—CH2—Si(OR)3-xR1x where X is —O— or —O—CO—NR″—. The compositions are storage stable and can be cured without use of tin catalysts.
摘要:
Isocyanate-free foamable mixtures suitable for filling construction voids and for other uses, comprise isocyanate-free, alkoxysilane-terminated prepolymers (A) which have a silane end group of the formula [1], where X and Y are each an oxygen atom, an N—R3 group or a sulfur atom, R1 is an alkyl, cycloalkyl, alkenyl or aryl radical having 1-10 carbon atoms, R2 is an alkyl radical having 1-2 carbon atoms or an ω-oxyalkylalkyl radical having a total of 2-10 carbon atoms, R3 is a hydrogen atom, an alkyl, alkenyl or aryl radical having 1-10 carbon atoms or a —CH2—SiR1z(OR2)3-z group, and z is 0 or 1, with the proviso that at least one of the two groups X and Y is an NH function, and (B) blowing agents.
摘要:
α-aminoalkoxysilanes wherein the α-amino group is a tertiary amino group, and which also contains a further reactive group, display excellent reactivity of the alkoxy groups while remaining stable with respect to decomposition and byproduct formation, particularly through cleavage of the Si-C bond. The α-aminosilanes are particularly useful for preparing alkoxysilyl-terminated prepolymers which exhibit high cure rates in the presence of moisture, and for functionalizing particles reactive therewith.
摘要:
Both flexible and rigid foams may be prepared by reacting di- or polyisocyanates with organopolysiloxanes which are prepared by reaction of silanol-terminated organopolysiloxanes with organosilicon compounds containing alkyleneoxy or alkylenamino groups bonded on both ends to silicon, thus resulting in organopolysiloxanes having 95% or more of aminoalkyl or hydroxyalkyl terminal groups.
摘要:
Condensation curable systems employ ordinarily highly reactive polymers bearing methylene-linked alkoxysilyl groups. By limiting the amounts of activating compounds during the preparation of such polymers, the reactivity is sharply decreased, yet can be increased by addition of suitable catalysts. As a result, the polymers may be easily processed, yet the moisture curing times may be adjusted readily.
摘要:
Blocked silyl isocyanates contain a methylene group between the blocked isocyanate group and silicon. The blocked isocyanates are easily prepared in high yield and purity.
摘要:
Alkoxysilyl-terminated preopolymers prepared by reacting an alkoxysilane with a prepolymer prepared by reacting a di- or polyisocyanate with both a low molecular weight diol or polyol and a high molecular weight polyol, the respective polyol components present within a specific ratio range, and giving rise to an increased content of urethane groups, and an inhomogenous distribution thereof exhibit high tensile strength and elongation, even without the use of fillers.
摘要:
Both flexible and rigid foams may be prepared by reacting di- or polyisocyanates with organopolysiloxanes which are prepared by reaction of silanol-terminated organopolysiloxanes with organosilicon compounds containing alkyleneoxy or alkylenamino groups bonded on both ends to silicon, thus resulting in organopolysiloxanes having 95% or more of aminoalkyl or hydroxyalkyl terminal groups.
摘要:
The invention relates to a one-step process for the preparation of acryloyl group-containing liquid-crystalline monomers of the general formula (1) (Z—Y1—A2—Y2—)mM(—O—A1-acrylate)n (1) in which mesogenic alcohols of the general formula (2) (Z—Y1—A2—Y2—)mM(OH)n (2) are reacted with esters of 3-chloropropionic acid of the general formula (3) ClPr—A1—X (3) with elimination of HCl, where acrylate is an acrylate radical, ClPr is a 3-chloropropionate radical, A1 are identical or different alkyl chain spacers having 2-20 carbon atoms, in which the carbon chain may be interrupted by non-adjacent ether, thioether, or imino groups, A2 are radicals A1 or single chemical bonds, M is a mesogenic group, X is a leaving group, Z are alkyl radicals or crosslinkable groups, Y1 and Y2, independently of one another, are a single chemical bond, —O—, —S—, —O—CO—, —CO—O—, —O—CO—O, —CO—NR1—, —NR1—CO—, —O—CO—NR1—, —NR1—CO—O— or —NR1—CO—NR1—, R1 is hydrogen or a C1-C4-alkyl radical, n is 1, 2, 3 or 4, and m is 0, 1, 2 or 3.