摘要:
An organopolysiloxane photoinitiator having an average of at least two siloxane units, of which at least an average of one siloxane unit per organopolysiloxane molecule has the formula:X.sub.a R.sub.b SiO(.sub.4-a-b)/2 (I)wherein a is an integer of 1-3, b is an integer of 0-2 and a plus b equals 1-3; R is C.sub.1 -C.sub.10 hydrocarbyl or halogen substituted C.sub.1 -C.sub.10 hydrocarbyl; and X is a substituted acetophenone photomoiety selected from: ##STR1## where R.sup.1 is any substituent which will not interfere with hydrosilation, n is an integer between 0 and 5 in formulas (II), (IIa), (III), (IIIa), (IV) and (IVa) and between 0 and 4 in formula (III) and (IIIa); m is 0 or 1; R.sup.2 is alkyl or substituted alkyl; R.sup.3 is H, alkyl or aryl; R.sup.4 is a divalent hydrocarbon group having between 2 and 10 carbon atoms or an alkylene oxy alkylene group; R.sup.5 is a group selected from H, alkyl, aryl, organosilyl, or the reaction product of an isocyanate esterification reagent or an etherification reagent with the hydroxyl product formed when R.sup.5 is H and R.sup.6 is a trivalent hydrocarbon or hydrocarbon oxyhydrocarbon group.The silicones are prepared by hydrosilation of the corresponding olefinically or acetylenically unsaturated acetophenones.
摘要:
Polyorganosiloxane photoinitiators containing aryoyl formate photomoieties bonded to silicon atoms via non-hydrolyzable Si-C bonds. They may be prepared from alkenyl or alkynyl aryoyl formates and polyorganosiloxanes containing silicon hydride groups via hydrosilation. They are effective photoinitiators for photocurable silicone resins and for ethylenically unsaturated monomers, producing cured films with good weatherability and low temperature flexibility.
摘要:
A polyorganosiloxane polymer having a structure represented by one of the formulas(AB).sub.m Cor[(AB).sub.m ].sub.n SiR.sub.(4-n)where the R groups are the same or different organic groups other than acrylic groups or groups co-curable therewith; A is a linear polyorganosiloxane segment containing between 3 and about 50 siloxane repeat units at least 3 of which are acrylic group containing repeat units represented by the formula ##STR1## where R.sup.1 is lower alkyl, the R.sup.2 groups are the same or different alkylene, alkyleneoxy or alkenylene groups, and y is 0-4; B is a polyorganosiloxane segment represented by the formula ##STR2## where x is an integer of at least 100; C is A or a triorganosilyl group; m is an integer of 1 or more; and n is 3 or 4.
摘要:
An antiperspirant composition is disclosed in the form of a transparent stick. The composition comprises a mixture of aluminum chlorohydrate, nonionic surfactant, liquid oil, and water, the latter being present in an amount from 20 to 50%. Preferably, the liquid oil is a combination of volatile silicone and emollient oil.
摘要:
A polyorganosiloxane polymer having a structure represented by one of the formulas(AB).sub.m C or [(AB).sub.m ].sub.n SiR.sub.(4-n)where the R groups are the same or different organic groups other than acrylic groups or groups co-curable therewith; A is a linear polyorganosiloxane segment containing between 3 and about 50 siloxane repeat units at least 3 of which are acrylic group containing repeat units represented by the formula ##STR1## where R.sup.1 is lower alkyl, the R.sup.2 groups are the same or different alkylene, alkyleneoxy or alkenylene groups, and y is 0-4; B is a polyorganosiloxane segment represented by the formula ##STR2## where x is an integer of at least 100; C is A or a triorganosilyl group; m is an integer of 1 or more; and n is 3 or 4.
摘要:
Compositions of (a) a silicone resin characterized by an intermediate region free of acrylic groups, at least 150 siloxane units long, and terminal acrylic groups; (b) at least 10% of a fumed silica filler; and (c) a photoinitiator, can be cured by UV irradiation to tough elastomeric materials useful in adhesive and sealant applications.
摘要:
Polysiloxane polymers with photoinitiating functionality. The polymers may be obtained by reacting .alpha.-allylbenzoin ethers with a siloxane or polysiloxane containing a plurality of silicon hydride groups. Alternatively, the allylbenzoin ethers may be reacted with a hydrolyzable hydrosilane and further reacted with other hydrolyzable organosilanes or siloxanes to form the polysiloxane with pendant photoinitiating benzoin ether groups. The other hydrolyzable silanes or siloxanes may include photocurable groups to yield self curing polymers. In the same manner, photoinitiating siloxane polymers of the first method may be further polymerized to yield self curing products. The photoinitiating polymers may also be combined with ethylenically unsaturated monomers or other silicones with photocurable groups to yield photocurable compositions.
摘要:
A method of curing a liquid silicone composition to a crosslinked polymer on a substrate having shadow areas no readily accessible to direct UV light, the method comprising:(a) applying a liquid composition to the substrate in a manner so as to cover both the light accessible and the shadow areas, the composition comprising a radical photoinitiator and a crosslinkable polydihydrocarbylsiloxane prepolymer having a molecular weight of at least 1000, having a plurality of acrylate or methacrylate groups bound thereto and further including a plurality of groups of the formula ##STR1## where R.sup.1 is a hydrolyzable organic group and R.sup.2 is R.sup.1 or, if R.sup.1 is dialkylamino, R.sup.2 is R.sup.1 or hydrocarbyl;(b) irradiation the substrate with UV irradiation sufficient to substantially cure the composition in the areas directly accessible to UV light, and(c) exposing the composition on the substrate to moisture for sufficient time to cure the composition in the shadow areas. Suitable polydihydrocarbyl siloxanes have the formula: ##STR2## where n is an integer, R.sup.1 is selected from amino, oxime or --OOCR.sup.3, R.sup.2 is R.sup.1 or hydrocarbyl, provided that when R.sup.1 is not amino, R.sup.2 is the same as R.sup.1, R.sup.3 is hydrocarbyl, R.sup.4 is H or methyl, R.sup.5 is a organo group having a carbon atom bound to the adjacent silicon atom and R.sup.6 is a hydrocarbyl group, said prepolymer having a molecular weight of at least 1,000.
摘要:
A polyorganosiloxane polymer having a structure represented by one of the formulas(AB).sub.m C or [(AB).sub.m ].sub.n SiR.sub.(4-n)where the R groups are the same or different organic groups other than acrylic groups or groups co-curable therewith; A is a linear polyorganosiloxane segment containing between 3 and about 50 siloxane repeat units at least 3 of which are acrylic groups containing repeat units represented by the formula ##STR1## where R.sup.1 is H or lower alkyl, R.sup.2 is alkylene or alkenylene, and y is 0-4; B is a polyorganopolysiloxane segment represented by the formula ##STR2## where x is an integer of at least 100; C is A or a triorganosilyl group; m is an integer of 1 or more; and n is 3 or 4.
摘要:
Polyorganosiloxanes having an average of more than two siloxane repeat units, at least one of which repeat units includes a photoinitiating group bound to the silicon atom thereof, the photoinitiating group having the formula ##STR1## where R.sup.1 and R.sup.2 are the same or different alkyl groups or R.sup.1 and R.sup.2 are alkylene groups linked to each other so that R.sup.1 and R.sup.2 together with the carbon atom to which both are attached comprise a cycloalkyl group, and R.sup.3 is H or hydrocarbyl.Compositions of these polyorganosiloxanes and silicones or organic monomers with free radical curable groups are readily cured by irradiation with UV light.