摘要:
Solventless, thermoplastic silicone pellets are prepared blending silicone resins (A) of the MQ-type and with predominantly linear silicone fluids (B), such as polydimethylsiloxane liquids and gums, to substantially homogeneity. The blends are heated to a predetermined compression-forming temperature, compression-formed to a densified mass and shaped into a pellet form. The composition of the pellets is balanced such that the pellets exhibit plastic flow at the predetermined compression-forming temperature and resist agglomeration at temperatures at or below a predetermined maximum storage temperature.
摘要:
Solventless silicone resins, which exhibit a high degree of reconstitution, are produced in forms such as powders and flakes. The degree of reconstitution is judged by the fact that silicone resin/fluid alloys produced therefrom exhibit only a minor shift in T.sub.g, the glass transition temperature, in comparison to analogous alloys produced from solvent dispersed (virgin) resin. Resin, and preferably virgin resin, is dispersed in a volatile liquid dispersant and blended with a nonvolatile silicone fluid. Thereafter, the volatile liquid dispersant is removed by means such as spray-drying or evaporation, resulting in the solventless resin forms of the invention.
摘要:
A method of dispersing silicone compositions in organic thermoplastic materials is disclosed. The novel compositions produced by the method of the invention have a fine and relatively uniform dispersion or organosilicone in an organic thermoplastic. An organosilicone resin (A) and a predominantly linear silicone fluid (B) are first blended to substantial homogeneity to form an organosilicone alloy therefrom. The organosilicone alloy exhibits thermoplastic behavior and has a temperature-dependent complex viscosity .eta.*.sub.Si (T) associated therewith. Likewise the organic thermoplastic materials have a temperature-dependent complex viscosity, .eta.*.sub.OTP (T), associated therewith. The organic thermoplastic and the organosilicone alloy are thereafter mixed at a predetermined mixing temperature, T.sub.m, and a predetermined shear strain rate. The organic thermoplastic material and the organosilicone alloy are both in a flowable state at T.sub.m. The value of T.sub.m is selected to be about .+-.30.degree. C. of a temperature, T.sub.0, wherein the absolute value of {72*.sub.OTP (T.sub.0)-.eta.*.sub.Si (T.sub.0)} is at its lowest value, at the predetermined shear strain rate.
摘要:
An additive to improve the hydrophobicity of a thermoplastic resin wherein the additive is at least 0.3 parts by weight of a thermoplastic silicone blend, said thermoplastic silicone blend having:(A) an organosilicone resin of the empirical formula(R.sub.3 Sio.sub.1/2)a (R.sub.2 SiO.sub.2/2)b (RSiO.sub.3/2)c( SiO.sub.4/2)dwherein: a and d are positive numerical values and b and c are zero or positive numerical values with the provisos that a+b+c+d=1, 0.ltoreq.(b+c).ltoreq.0.2 and the ratio of a:(b+c+d) is between about 0.3 and 1.0; and R is a monovalent radical independently selected from the group consisting of hydrogen, hydroxyl, alkyl, alkenyl, alkoxy, oximo, aryl, epoxide, carboxyl, ether, polyether, amide and alkyl amino radicals, which R groups may be the same or different, with the proviso that at least sixty mole percent of said R radicals are methyl; and(B) a predominantly linear silicone fluid having the empirical formula(R'.sub.3 SiO.sub.1/2)x (R'.sub.2 SiO.sub.2/2)y (R'SiO.sub.3/2)zwherein: x and y are positive numerical values and z is 0 or a positive numerical value with the provisos that x+y+z=1, y/(x+y+z).gtoreq.0.8; and R' is a monovalent radical independently selected from the group consisting of hydroxyl and alkyl radicals, which R' groups may be the same or different, with the proviso that at least sixty mole percent of said R' radicals are methyl;said organosilicone resin (A) and said predominantly linear silicone fluid (B) being present in relative amounts such that said blends have a dynamic shear modulus (G*), measured at a frequency of 10 radians/sec, of at least 5.times.10.sup.7 dyne/cm.sup.2 at temperatures less than said predetermined maximum storage temperature.
摘要翻译:一种用于改善热塑性树脂的疏水性的添加剂,其中所述添加剂为至少0.3重量份的热塑性硅氧烷共混物,所述热塑性硅氧烷共混物具有:(A)经验式(R3Si1 / 2)a的有机硅氧烷树脂(R2SiO2 / 2)b(RSiO3 / 2)c(SiO4 / 2)d其中a和d为正数值,b和c为零或正数值,条件是a + b + c + d = /=(b+c)=0.2,a:(b + c + d)的比例在约0.3和1.0之间; 并且R是独立地选自氢,羟基,烷基,烯基,烷氧基,肟基,芳基,环氧化物,羧基,醚,聚醚,酰胺和烷基氨基的一价基团,R基团可以相同或不同 ,条件是至少60摩尔%的所述R自由基是甲基; 和(B)具有经验式(R'3SiO1 / 2)x(R'2SiO2 / 2)y(R'SiO3 / 2)z的主要线性硅氧烷流体,其中x和y是正数值,z是0或 正数值,条件是x + y + z = 1,y /(x + y + z)> = 0.8; 并且R'是独立地选自羟基和烷基的一价基团,R'基团可以相同或不同,条件是至少60摩尔%的所述R'基团是甲基; 所述有机硅氧烷树脂(A)和所述主要线性硅氧烷流体(B)以相对的量存在,使得所述共混物的动态剪切模量(G *)以10弧度/秒的频率测量为至少5×10 7达因/ cm2,在低于所述预定最大存储温度的温度下。
摘要:
A method of obtaining fine-grained, free-flowing powdered silicone resins is disclosed. The powdered silicone resins contain very low or no residual aromatic solvents or other volatile organic compounds. The method includes the steps of (1) preparing a solution of an MQ silicone resin dissolved in a volatile liquid organosilicon solvent, such as hexamethyldisiloxane, and (2) spray-drying the solution obtained in step (1) to produce the silicone resin powder.
摘要:
The present invention relates generally to a novel process for making a solid solventless MQ resin comprising the steps of (1)(A) feeding at least one MQ resin dispersed in a volatile solvent into an extrusion device, (2) removing the volatile solvent to form a solid solventless MQ resin; and (3) recovering the solid solventless MQ resin, provided steps (1) to (3) are completed without the addition of a linear silicone fluid.
摘要:
This invention relates to a flame retardant composition comprising: (a) 81 to 99.99 weight percent of a thermoplastic resin, thermoset resin, thermoplastic resin blend, or thermoset resin blend which upon burning forms a char and (b) 0.01-19 weight percent of a silsesquioxane resin having a weight average molecular weight of greater than 300.
摘要:
A silicone composition comprising (A) 100 parts by weight of a polydiorganosiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule; (B) 75 to 150 parts by weight of an organopolysiloxane resin having a number-average molecular weight of from 2,000 to 5,000 and consisting essentially of R.sup.3.sub.2 R.sup.4 SiO.sub.1/2 units and SiO.sub.4/2 units wherein each R.sup.3 is independently selected from the group consisting of monovalent hydrocarbon and monovalent halogenated hydrocarbon groups free of aliphatic unsaturation, R.sup.4 is selected from the group consisting of R.sup.3 and alkenyl, the mole ratio of R.sup.3.sub.2 R.sup.4 SiO.sub.1/2 units to SiO.sub.4/2 units is from 0.6:1 to 1.1:1, and the resin contains an average of from 2.5 to 7.5 mole percent of alkenyl groups; (C) an organohydrogenpolysiloxane having an average of at least three silicon-bonded hydrogen atoms per molecule in an amount sufficient to provide from one to three silicon-bonded hydrogen atoms per alkenyl group in components (A) and (B) combined; (D) an adhesion promoter in an amount sufficient to effect adhesion of the composition to a substrate; and (E) a hydrosilylation catalyst in an amount sufficient to cure the composition.
摘要:
A coating composition contains a carbamate-functional film-forming material, a carbinol-functional, nonlinear siloxane resin, and an aminoplast crosslinking agent. The composition provides excellent high-bake repair adhesion of a repair-coating layer over the initial coating.
摘要:
A radiation or thermal curable coating composition contains a cycloaliphatic epoxide resin, a carbinol functional silicone resin or an anhydride functional silicone resin, and a thermal or photoactivated acid catalyst. An organic polyol may also be included in the composition as an optional component. The composition is useful as a radiation curable coating, as an adhesive, a photodefinable coating, or as a thermal cure coating. The cycloaliphatic epoxide resin adds toughness and adhesion to the composition, whereas either of the carbinol functional silicone resin or the anhydride functional silicone resin provides the composition with water resistance, weatherability, thermal stability, and flexibility.