GROSSMANN MATTHIAS (DE)
MISTRY UMESH (GB)
WILKEN KAREN (DE)
WO2022004463A1 | 2022-01-06 | |||
WO2019088066A1 | 2019-05-09 |
EP3705537A1 | 2020-09-09 | |||
US4271425A | 1981-06-02 | |||
US4087585A | 1978-05-02 | |||
US3159601A | 1964-12-01 | |||
US3159662A | 1964-12-01 | |||
US3419593A | 1968-12-31 | |||
US3715334A | 1973-02-06 | |||
US3775452A | 1973-11-27 | |||
US3814730A | 1974-06-04 | |||
US4530879A | 1985-07-23 | |||
EP0122008A1 | 1984-10-17 | |||
EP0146307A2 | 1985-06-26 | |||
US4510094A | 1985-04-09 | |||
US20030199603A1 | 2003-10-23 | |||
US4640939A | 1987-02-03 | |||
EP1672031A1 | 2006-06-21 |
LEWISCOLBORNGRADEBRYANTSUMPTERSCOTT, ORGANOMETALLICS, vol. 14, 1995, pages 2202 - 2213
Claims 1. A potting compound for use in the potting of electronic equipment, the potting compound comprising a curable silicone composition the composition comprising: (A) at least one polyorganosiloxane having at least one alkenyl groups bonded to a silicon atom, (B) at least one organohydrogensiloxane having at least one SiH group, (C1) at least one photo-activatable hydrosilylation catalyst, (C2) at least one non-photo-activatable hydrosilylation catalyst, and (D) optionally additives. 2. The potting compound according to claim 1, wherein the electronic components are for automotive or power applications. 3. The potting compound according to claims 1 or 2 for the protection of an electronic equipment against moisture, dust and environmental hazards. 4. The potting compound according to any of claims 1-3, wherein the at least one polyorganosiloxane having at least one alkenyl group A) is selected from the groups of polyorganosiloxanes having the formula (Ia): [MaDbTcQdR9e]m (Ia) wherein the indices in formula (Ia) are defined as follows: a = 0 - 10 b = 0 - 2000 c = 0 - 50 d = 0 - 1 e = 0 - 300 m = 1 - 1000 with a, b, c, d and m being such that the viscosity of component (A) at 20 °C is less than 15000 mPa.s(measured at a shear rate of D=10 s-1 according to DIN 53019 and for viscosities below 5000 mPa.s measured according to DIN 53015), and M is selected from R3SiO1/2 and M*, D is selected from R2SiO2/2 and D*, T is selected from RSiO3/2 and T*, and Q=SiO4/2, R9 is selected from divalent organic groups bound via carbon to two silicon atoms and wherein each R, which may be the same or different, is selected from an optionally substituted alkyl group with up to 30 carbon atoms, an optionally substituted aryl with up to 30 carbon atoms, and an organic group bound to Si via carbon comprising a poly(C2-4)-alkyleneoxy moiety with up to 1000 (C2-C4)alkyleneoxy groups, the groups R being free of aliphatic unsaturation, and wherein M*= R1pR3-pSiO1/2, D*= R1qR2-qSiO2/2, T*= R1SiO3/2, wherein p= 1-3 q= 1-2 R is as defined before, and R1 is selected from alkenyl groups. 5. The potting compound according to any of claims 1-4, wherein the component (A) has the formula (Ia1) (Ia1), wherein R1 and R are as defined above and x is ≥ 0. 6. The potting compound according to any of claims 1-5, wherein the component (B) is selected from the group of (B1) a linear SiH-containing polyorganosiloxane and (B2) a branched SiH- containing polyorganosiloxane. 7. The potting compound according to any of claims 1-6, wherein the component (B) is selected from the group of (B1) a linear polydiorganosiloxane having an SiH group at each end, and (B2) a branched SiH-containing polyorganosiloxane containing at least one MH unit. 8. The potting compound according to any of claims 1-7, wherein the branched SiH- containing polyorganosiloxane (B2) are selected from polyorganosiloxanes comprising at least one siloxy unit selected from the group consisting of a Q unit: and a T unit: wherein R is as defined above, and at least one siloxy unit MH: wherein R is alkyl. 9. The potting compound according to any of claims 1-8, wherein the branched SiH- containing polyorganosiloxane B2) are selected from polyorganosiloxanes consisting of at least one siloxy unit Q: and at least one siloxy unit MH: 10. The potting compound according to any of claims 1-9, wherein the SiH-containing polyorganosiloxane resins (B2) are selected from polyorganohydrogensiloxanes consisting of Q and MH units of the formula {[Q][MH]0,01-10}m wherein Q and MH are as defined above, and m is about 1 to about 20. 11. The potting compound according to any of claims 1-10 comprising a linear polydiorganosiloxane (B1) having an SiH group at each end, and a branched SiH-containing polyorganosiloxane (B2) consisting of Q and MH units of the formula {[Q][MH]0,01-10}m wherein Q, MH and m are as defined above. 12. The potting compound according to any of the preceding claims, wherein the organo- metallic hydrosilylation catalyst (C1) or (C2) is selected from the group consisting of transition metal complex catalysts selected from platinum, palladium, rhodium, nickel, iridium, ruthenium, and iron complexes and combinations thereof. 13. The potting compound according to any of claims 1-12, wherein (C1) is a photo- activatable platinum catalyst selected from the group consisting of η5-(optionally substituted) cyclopentadienyl platinum(IV) complexes, ß-diketonato trimethylplatinum (IV) complexes, bis(β- diketonato) platinum(II) complexes, bis(phosphine) platinum(II) complexes, cyclooctadiene platinum(II) complexes, and mixtures thereof. 14. The potting compound according to any of claims 1-13, wherein the non- photoactivatable hydrosilylation catalyst (C2) is platinum catalyst selected from the group consisting of platinum compounds such as chloroplatinic acid, or platinum complexes such as platinum/vinylsiloxane complexes, or mixtures thereof. 15. The potting compound according to any of claims 1-14, further comprising the additive (D) selected from of the group consisting of a hydrosilylation reaction inhibitor. 16. The potting compound according to any of claims 1-15, further comprising as additives (D) at least one selected from the group consisting of an optical brightener or UV tracer (fluorescent whitening agent). 17. The potting compound according to any of claims 1-16, comprising: - 100 parts per weight of at least one polyorganosiloxane (A) having at least one alkenyl group bonded to a silicon atom, - 0.1 to 30 parts per weight of at least one organohydrogensiloxane (B) having at least one SiH group, - 0.1 to 3.5 weight per cent of at least one photo-activatable hydrosilylation catalyst (C1) based on total weight of (A) and (B), - 1 to 1000 ppm at least one non-photo-activatable hydrosilylation catalyst (C2) based on the total weight of the components (A) and (B), and - 0.1 to 10 parts of optionally additives (D). 18. The potting compound according to any of claims 1-17, comprising: - 100 parts per weight of at least one polyorganosiloxane (A) having at least one, alkenyl group bonded to a silicon atom, - 0.1 to 25 parts per weight of at least one linear polyorganosiloxane (B1) having an SiH group at each end, - 0.1 to 5 parts per weight of at least one polyorganohydrogensiloxane (B2) having at least one siloxy unit Q and at least one siloxy unit MH as defined above, - 1 to 1000 ppm of at least one photo-activatable hydrosilylation catalyst (C1) based on total weight of (A) and (B), - 0.1 to 3.1 weight percent at least one non-photo-activatable hydrosilylation catalyst (C2) based on the total weight of the components (A) and (B), and - 0.1 to 10 parts (D) optionally additives. 19. The potting compound according to claim 17 or 18, wherein the said silicone composition has a viscosity below 1000 mPa.s at 20°C measured according to DIN 53015. 20. The potting compound of any of claims 1-19 wherein: (A) is selected from at least one linear polyorganosiloxane having at both ends one alkenyl group bonded to a silicon atom, (B) is selected from a linear polydiorganosiloxane (B1) having an SiH group at each end, and an SiH-containing polyorganosiloxane resin (B2) consisting of Q and MH units as defined (C1) at least one photo-activatable hydrosilylation catalyst, (C2) at least one non-photo-activatable hydrosilylation catalyst, and 21 The potting compound according to any of claims 1-20, further comprising at least one adhesion enhancing agent (E). 22. The potting compound of claim 21, wherein the adhesion agent is selected from a titanate compound. 23. The potting compound according to claim 22 wherein the adhesion enhancing agent (E) is tetra-n butyltitanate. 24. The potting compound according to claim 23 wherein the said silicone composition has a viscosity below 1000 mPa.s at 20°C measured according to DIN 53015. 25. A process of curing the curable silicone composition as defined in any of the claims 1 to 24 to a cured silicone composition in a chamber/cavity of the electronic component having areas not readily accessible to direct UV light irradiation, the process comprising: a) applying the said curable silicone composition into the chamber/cavity in a manner so as to fill in the chamber/cavity. b) irradiating the chamber/cavity with UV irradiation sufficient to substantially cure the composition in the areas directly accessible to UV light, and c) exposing the composition on the chamber/cavity to a temperature of ≥ 20°C for sufficient time to cure the composition in the areas not accessible to UV light. 26. A process of curing of the curable silicone compositions as defined in any of the claims 1 to 24 to a cured silicone composition for the manufacture of connector potting, the process comprising a) applying said curable silicone composition to a chamber/cavity/pocket comprising pin connectors, b) exposing said curable silicone composition to UV light, and c) then curing in areas not accessible to UV light in a temperature range of 20 to 80°C. 27. A cured composition obtained by the curing of the curable silicone composition according to any of the claims 25 to 26 by a UV radiation cure step followed by a cure step at a temperature in the range of ≥ 20°C and ≤80°C. I. mixing, so as to form a curable composition as defined in any of the claims 21 to 23, II. applying a potting of/dispensing said curable composition into a chamber/cavity of the electronic component; and III. curing said curable composition to said chamber/cavity by exposing the said curable composition in the potting chamber/cavity to a source of UV radiation and thereafter non photoactivatable curing said curable composition at a temperature in the range of 20 to 80°C. 29. The article of claim 28 wherein the substrate is a circuit board or pin connector. 30. Use of the curable silicone composition, as defined in any of the preceding claims in the form of a kit of two parts system. 31. A composition comprising: (a) a first part comprising (A) at least one polyorganosiloxane having at least one alkenyl group bonded to a silicon atom, (C1) at least one photo-activatable hydrosilylation catalyst, and (C2) at least one non-photo-activatable hydrosilylation catalyst, and (b) a second part comprising (B) at least one organohydrogensiloxane having at least one SiH group, and (D1) a polyorganosiloxane, different from (B)comprising at least one unit selected from the group consisting of R(H)SiO2/2 and R5(R)SiO2/2, wherein R is selected from optionally substituted alkyl with up to 30 carbon atoms, optionally substituted aryl with up to 30 carbon atoms, and an organic group bound to Si via carbon comprising a poly(C2-4)-alkyleneoxy moiety with up to 1000 (C2-C4)alkyleneoxy groups, the groups R being free of aliphatic unsaturation, R5 is selected from the group consisting of unsaturated aliphatic group with up to 14 carbon atoms, epoxy–group-containing aliphatic group with up to 14 carbon atoms, cyanurate–containing group, and an isocyanurate–containing group, and further comprising at least one unit of the formula (3): - O2/2(R)Si-R4-SiRd(OR3)3-d (3) wherein R in formula (3) may be identical or different and is selected from optionally substituted alkyl with up to 30 carbon atoms, optionally substituted aryl with up to 30 carbon atoms, and an organic group bound to Si via carbon comprising a poly(C2-4)-alkyleneoxy moiety with up to 1000 (C2- C4)alkyleneoxy groups, the groups R being free of aliphatic unsaturation,, R3 is selected from H (hydrogen) and alkyl radicals having 1 to 6 carbon atoms, and may be identical or different, R4 is a difunctional optionally substituted hydrocarbyl radical with up to 15 carbon atoms, which may contain one or more heteroatoms selected from O, N and S atoms, and which is bond to the silicon atoms via an Si-C-bond, and d is 0 to 2. 32. The composition of claim 31, wherein the polyorganosiloxane (A) is selected from at least one linear polyorganosiloxane having at least one alkenyl group; and the organohydrogensiloxane (B) is selected from at least one linear polydiorganosiloxane (B1) having an SiH group at each end, and at least one SiH-containing polyorganosiloxane resin (B2) consisting of Q and MH units where Q is SiO4/2, and MH is HR2SiO1/2, where R of the MH unit may be identical or different and is selected from optionally substituted alkyl with up to 30 carbon atoms, optionally substituted aryl with up to 30 carbon atoms, and an organic group bound to Si via carbon comprising a poly(C2-4)-alkyleneoxy moiety with up to 1000 (C2-C4) alkyleneoxy groups, the groups R being free of aliphatic unsaturation. 33. The composition of claim 32 comprising: - 100 parts per weight of the at least one polyorganosiloxane (A) having at least one alkenyl group bonded to a silicon atom, - 0.1 to 25 parts per weight of the at least one linear polyorganosiloxane (B1) having an SiH group at each end, - 0.1 to 5 parts per weight of the at least one polyorganohydrogensiloxane (B2) having at least one siloxy unit Q and at least one siloxy unit MH as defined above, - 1 to 1000 ppm of the at least one photo-activatable hydrosilylation catalyst (C1) based on total weight of (A) and (B), - 0.1 to 3.1 weight percent at least one non-photo-activatable hydrosilylation catalyst (C2) based on the total weight of the components (A) and (B), - 0.1 to 10 weight percent of the component (D1) based on the total weight of part (a) and (b), and - 0.001 to 10 parts per weight of an additive. 34. The composition of any of claims 31-33, wherein (D1) is selected from a compound of the formula (3a): R11 is R or R5; and R4 is a difunctional optionally substituted hydrocarbyl radical with up to 15 carbon atoms, which may contain one or more heteroatoms selected from O, N and S atoms, and which is bond to the silicon atoms via an Si-C-bond, s1 = 0-6 t1 = 0-6 s1 + t1 = 2 – 6 with the proviso that there is at least one group –(OSi(R)H)- or –(OSi(R)(R11)- in the compound. 35. The composition of claim 34, wherein the compound of formula (3a) has the formula: . 36. The composition of claim 34, wherein the compound of formula (3a) has the formula: . 37. The composition of ay of claims 31-36, wherein the polyorganosiloxane (A) is of the formula (Ia1): wherein each R is independently selected from a saturated organic group, each R1 is independently selected from an alkenyl group, and x is ≥ 0. 38. The composition of any of claims 31-37, wherein the composition, upon combining parts (a) and (b), has a viscosity of from about 50 mPa.s to about 10 Pa.s at 20°C measured at a shear rate of D=10 s-1 according to DIN 53019 for viscosities above 5000 mPa.s and measured according to DIN 53015 at 20°C for viscosities below 5000 mPa.s. 39. The composition of any of claims 31-37, wherein the composition, upon combining parts (a) and (b), has a viscosity of 100 mPa.s to about 1000 mPa.s at 20°C measured according to DIN 53015. 40. The composition of any of claims 31-37, wherein the composition, upon combining parts (a) and (b), has a viscosity of 200 mPa.s to about 800 mPa.s at 20°C measured according to DIN 53015. 41. The composition of any of claims 31-37, wherein the composition, upon combining parts (a) and (b), has a viscosity of 300 mPa.s to about 500 mPa.s at 20°C measured according to DIN 53015. 42. The composition according to any of claims 31-37, wherein the silicone composition has a viscosity below 1000 mPa.s at 20°C measured according to DIN 53015. 43. A process of curing the curable silicone composition as defined in any of claims 31 to 42 in a chamber/cavity of an electronic component having areas not readily accessible to direct UV light irradiation, the process comprising: (i) combining part (a) and part (b) to form the curable silicone composition; (ii) applying the curable silicone composition into the chamber/cavity in a manner so as to fill in the chamber/cavity; (iii) irradiating the chamber/cavity with UV irradiation sufficient to substantially cure the composition in the areas directly accessible to UV light; and (iv) exposing the composition on the chamber/cavity to a temperature of ≥ 20°C for sufficient time to cure the composition in the areas not accessible to UV light. 44. A process of curing the curable silicone compositions as defined in any of claims 31 to 42 to a cured silicone composition for the manufacture of connector potting or encapsulation of electronic components, the process comprising (i) combining part (a) and part (b) to form the curable composition; (ii) applying said curable silicone composition to a chamber/cavity/pocket comprising pin connectors, (iii) exposing said curable silicone composition to UV light, and (iv) curing in areas not accessible to UV light in a temperature range of 20 to 80°C. 45. An article prepared by the steps, comprising: (i) mixing part (a) and part (b), so as to form a curable composition as defined in any of claims 31 to 42, (ii) applying a potting of/dispensing of said curable composition into a chamber/cavity of the electronic component; and (iii) curing said curable composition to said chamber/cavity by exposing the said curable composition in potting chamber/cavity to a source of UV radiation and thereafter non- photoactivatable curing said curable composition at a temperature in the range of 20 to 80°C. 46. The article of claim 45, wherein the substrate is a circuit board or a connector plug. 47. A composition comprising: (A) at least one polyorganosiloxane having at least one, alkenyl groups bonded to a silicon atom, (B) at least one organohydrogensiloxane having at least one SiH group, (C1) at least one photo-activatable hydrosilylation catalyst, (C2) at least one non-photo-activatable hydrosilylation catalyst, and (D1) A polyorganosiloxane comprising at least one unit selected from the group consisting of R(H)SiO2/2 and R5(R)SiO2/2, wherein R is selected from optionally substituted alkyl with up to 30 carbon atoms, optionally poly(C2-4)-alkyleneoxy moiety with up to 1000 (C2-C4)alkyleneoxy groups, the groups R being free of aliphatic unsaturation, R5 is selected from the group consisting of unsaturated aliphatic group with up to 14 carbon atoms, epoxy–group-containing aliphatic group with up to 14 carbon atoms, cyanurate–containing group, and an isocyanurate–containing group, and further comprising at least one unit of the formula (3): -O2/2(R)Si-R4-SiRd(OR3)3-d (3) wherein R in formula (3) may be identical or different and is selected from optionally substituted alkyl with up to 30 carbon atoms, optionally substituted aryl with up to 30 carbon atoms, and an organic group bound to Si via carbon comprising a poly(C2-4)-alkyleneoxy moiety with up to 1000 (C2- C4)alkyleneoxy groups, the groups R being free of aliphatic unsaturation,, R3 is selected from H (hydrogen) and alkyl radicals having 1 to 6 carbon atoms, and may be identical or different, R4 is a difunctional optionally substituted hydrocarbyl radical with up to 15 carbon atoms, which may contain one or more heteroatoms selected from O, N and S atoms, and which is bond to the silicon atoms via an Si-C-bond, and d is 0 to 2. 48. A composition according to claim 47 or according to any one of the claims 31 to 42 further comprising an adhesion enhancing agent (E). 49. The composition of claim 48 having a lap shear strength of at least 0.1 MPa when interposed between a first substrate that is glass and a second substrate that is either Aluminium or PBT. 50. The composition of claim 48 or 49 having cohesive failure in the range of 60-100% in the cured state on a metal or plastic substrate in a OverLapShear (OLS) Test 51. A composition according to claim 50 having cohesive failure in the range of 60-100% in the cured state on an aluminium or PBT substrate in a OverLapShear (OLS) Test 52. Use of a curable silicone composition of any of claims 1-24, or 31-42, or 47-48 as a potting compound in the potting of electronic components. 53. The use according to claim 52, wherein the electronic components are for automotive or power applications. 54. The use according to claim 52, wherein the electronic components are for automotive or power applications. 55. The use of according to claim 52 for the protection against moisture, dust, and/or environmental hazards. |
In one embodiment, the component (D1) is selected from a compound of formula: wherein: R, R 3 , R 4 , R 5 are as defined above, s= 0 - 10 preferably = 0- 5 t= 0 – 50 preferably = 2- 30 u= 1-10 preferably = 1 s + t+ u =≤ 70 with the proviso that there is at least one group –(OSi(R)H)- or –(OSi(R)(R 5 )- in the compound. These compounds may comprise to a certain content Q or T branching groups, replacing the D units. R 5 is for example selected from:
Component (D2) is preferably selected from compounds of the formula (4): X-(CR 6 2)e-Y-(CH2)eSiRd(OR 3 )3-d wherein X is selected from the group consisting of halogen, pseudohalogen, unsaturated aliphatic group with up to 14 carbon atoms, epoxy–group-containing aliphatic group with up to 14 carbon atoms, cyanurate– containing group, and an isocyanurate–containing group, Y is selected from the group consisting of a single bond, a heteroatomic group selected from –COO–, –O–, –S–, –CONH–, –HN–CO–NH–, R 6 is selected from hydrogen and R as defined above, e is 0, 1, 2, 3, 4, 5, 6, 7, or 8, and may be identical or different, R is as defined above and may be identical or different, R 3 is as defined above and may be identical or different, d is 0, 1, or 2. Preferred examples of component (D2) include: (3e) for upper structure and (3f) for lower structure
(3h) wherein R and d are as defined above. Component (D2) can serve as in-situ surface treating agent for filler (E). It is preferred to use mixtures of silanes of the component (D2) Component (D3) is preferably selected from compounds of the formula (3i): wherein r is 0 or 1, R 7 may be the same or different group, which is selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, alkenyl group, alkoxy group, alkenyloxy group, alkenylcarbonyloxy group and an aryl group, and a group of formula –Ef-Si(OR)3-dRd, wherein R is identical or different, and d is as defined above, a group of formula –O-Si(R) 2 R 1 , wherein R and R 1 are as defined above, a group of formula –E f -Si(R) 2 H, wherein R is as defined above, h i E i di l t i ith t 8 b t d 0 t 3 h t t i selected from –O-, -NH-, C=O, and -C(=O)O-, and f is 0 or 1, and Z is selected from the following groups: wherein R 8 is selected from the group of a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl group, aryl group, alkenyl group and alkynyl group, and g is a positive number of at least 2, wherein at least one of the groups selected from R 7 and R 8 is reactive in hydrosilylation. Preferred components (D3) include: (3n) wherein Z, r, R 7 , R 3 , R and d are each as defined above.” In some embodiments, components (D1), (D2), and (D3) can be present in an amount of from about 0.1 weight percent to about 10 weight percent; from about 0.5 weight percent to about 7 weight percent; or from about 1 weight percent to about 5 weight percent based on the total weight of the composition. In one embodiment, the composition comprises at least one component (D1) in an amount of from about 0.1 weight percent to about 10 weight percent; from about 0.5 weight percent to about 7 weight percent; or from about 1 weight percent to about 5 weight percent based on the total weight of the composition. Other auxiliary components (component (D)) include: - Fillers: Examples of suitable fillers include those selected from, for example, TiO2, nano-TiO2, optical lightener (like Tinopal OB) and nano-silica. Silicon dioxide nanoparticles are also known as silica nanoparticles or nano-silica, which have stability, low toxicity and an ability to be functionalized with a range of molecules and polymers. Nano-silica particles are divided into P-type and S-type according to their structure. The P-type particles are characterized by numerous nanopores, which have a pore rate of 0.61 ml/g and exhibit a higher ultraviolet reflectivity compared to the S-type; the latter also has a comparatively smaller surface area. When the filler is nano-silica and is included into the silicone composition according to the invention, then the cured silicone composition will be transparent for a good UV curing. In one embodiment, the curable silicone composition does not contain any reinforcing filler in particular silica. - Non reinforcement filler: Examples of materials serving as fillers or extenders (BET-surface areas < 50 m²/g) are known as non- reinforcing fillers. They include for example powdered quartz, diatomaceous earths, powdered crystoballites, micas, aluminum oxides, and aluminum hydroxides. Titanium dioxides or iron oxides, Zn oxides, chalks, or carbon blacks whose BET surface areas are from 0.2 to less than 50 m 2 /g can be used also as heat stabilizer. These fillers are available under variety of trade names, examples being Sicron ^, Min-U-Sil ^, Dicalite ^, Crystallite ^. The materials known as inert fillers or extenders with BET surface areas below 50 m2/g should advantageously comprise no particles (< 0.005 % by weight) above 100 µm for use in silicone rubbers, in order that further processing generates no problems during downstream processing, e.g., passage through sieves or nozzles, or the mechanical properties of the articles produced therefrom are adversely affected. In one embodiment according to the invention, the used silicone composition comprises a UV tracer compound as compound (D) such as a benzoxazole compound and/or a bis-benzoxazole compound and/or a thiophenediyl benzoxazole compound and/or thiophenediyl bis-benzoxazole compound. Preferably the UV tracer compound is the 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole), also found as MPI Bright 100 UV Tracer from MPI Chemie, where it is used under UV light as marker for voids or uneven coverage or uneven curing in the mold for electronic components. The UV tracer a compound will fluoresce when exposed to UV electromagnetic radiation. - Hydrosilylation Inhibitor compound The rate of the hydrosilylation reaction can be affected as known by a number of additional compounds, the so-called inhibitors used as compound (D). This allows to further influence the rate of crosslinking after photoactivation, that is, the temperature and the time can be determined at which/in which the silicone rubber composition or mixture is cured or vulcanized to an elastomeric molded body after photoactivation. Appropriate inhibitors for the photoactivatable hydrosilylation of the present invention with platinum are inhibitors such as vinyl siloxanes, 1,3-divinyltetramethyldisiloxane or tetravinyltetramethyltetracyclosiloxane. Other known inhibitors such as ethynylcyclohexanol, 3- methylbutynol or dimethyl maleate can be used too. The inhibitors are used to delay the curing reaction after photoactivation in a desired manner. Basically, any inhibitors known for the class of the group of platinum metals can be used, if not already a sufficiently long processing time is achieved by selection of the ligands of the catalyst (C2). An exemplary embodiment is to use the catalysts with the vinyl siloxane based inhibitor even more preferably with tetravinyltetramethyltetracyclosiloxane. The total amount of the possible inhibitor auxiliaries as component (D) is preferably 0 to 15 parts by weight based on 100 parts by weight of component (A) and (B). - Opacifying fillers Among the opacifying fillers are also in particular non-transparent, in particular inorganic, pigments or carbon black. The use of these opacifying fillers is preferred only when pigmentation is necessary or the physical function like thermal or electrical conductivity is a requirement. The use of opaque non-transparent fillers requires changing the usual sequence of the activation and shaping steps in the process. Normally, if no or transparent fillers are used, the photo-activation through irradiation is carried out after the final shaping process. If opaque non-transparent fillers, which would inhibit the photo-activation of the photo-activatable catalyst, are used, the photo-activation step is carried out before the opaque non-transparent fillers are incorporated and the mixture is shaped. Component (E): Adhesion enhancing agent: In another embodiments the silicone composition comprises an adhesion enhancing agent (E) wherein the adhesion enhancing agent is a metal based compound, like titanate compounds more preferably tetra-n butyltitanate which allows the silicone composition to better adhere to metal surfaces, preferably Aluminum and also to plastic substrates such as, but not limited to, PBT (Polybutylenterephthalate), PPS (Polybutylensuccinate), ABS(Acrylnitril-Butadien-Styrol-Copolymer), PC (polycarbonate), PPO (polypropylene oxide), PP (polypropylene), HDPE (High-Density Polyethylen), and the like, more preferably PBT. In a further embodiment, the silicone composition comprises an adhesion enhancing agent (E) in an amount of 0.001 part to 0.1 part per weight related to 100 parts per weight of (A), preferably from 0.005 to 0.075 per weight related to 100 parts per weight of (A), more preferably from 0.01 to 0.06 per weight related to 100 parts per weight of (A), even more preferably from 0.015 to 0.05 per weight related to 100 parts per weight of (A). In one embodiment, the composition is provided as a composition comprising (a) a first part comprising the (A) component, the (C1) photo-activatable catalyst, and the (C2) non-photo-activatable catalyst; and (b) a second part comprising the (B) component. The second part (b) may optionally include one or more additional components such as one or more alkenyl functional polyorganosiloxanes (A), adhesion enhancing agents, inhibitors etc. Ratios between different components in the used silicone composition In one embodiment according to the invention the silicone composition for potting application for electronic components comprises: - 100 parts per weight of at least one polyorganosiloxane (A) having at least one, preferably at least two alkenyl groups bonded to a silicon atom, - 0.1 to 30 parts per weight of at least one organohydrogensiloxane (B) having at least one SiH group, - 0.1 to 3.5 weight percent of at least one photo-activatable hydrosilylation catalyst (C1) based on total weight of (A) and (B), - 1 to 1000 ppm at least one non-photo-activatable hydrosilylation catalyst (C2) based on the total weight of the components (A) and (B), and - 0 to 10 parts of optionally additives (D). In one embodiment, the composition includes an additive (E) selected from an adhesion enhancing agent in an amount of 0.1 to 10 parts per weight related to 100 parts per weight of component (A). In one embodiment, the adhesion enhancing agent is selected from a titanate compound. In another embodiment according to the invention the silicone composition for potting application comprises: - 100 parts per weight of at least one linear polyorganosiloxane (A) having one alkenyl group bonded to a silicon atom at each end, - 0.01 to 30 parts by weight of component (B) selected from the group of (B1) a linear SiH-containing polyorganosiloxane and (B2) a branched SiH-containing polyorganosiloxane, - 0.1 to 3.5 weight percent of at least one photo-activatable hydrosilylation catalyst (C1) based on total weight of (A) and (B), - 1 to 1000 ppm at least one non-photo-activatable hydrosilylation catalyst (C2) based on the total weight of the components (A) and (B), and - 0 to 10 parts of optionally additives (D). In one embodiment, the composition includes an adhesion enhancing agent in an amount of 0.1 to 10 parts per weight related to 100 parts per weight of component (A).. In one embodiment, the adhesion enhancing agent is selected from a titanate compound. In one embodiment according to the invention the used silicone composition for potting application comprises: - 100 parts per weight of at least one linear polyorganosiloxane (A) having one alkenyl, preferably at least two alkenyl groups bonded to a silicon atom at each end, - 0.01 to 30 parts by weight of component (B) selected from the group of (B1) a linear SiH-containing polyorganosiloxane having one SiH group at each end and (B2) a branched SiH-containing polyorganosiloxane consisting of at least one M H unit and at least one Q unit, - 0.1 to 3.5 weight percent of at least one photo-activatable hydrosilylation catalyst (C1) based on total weight of (A) and (B), - 1 to 1000 ppm at least one non-photo-activatable hydrosilylation catalyst (C2) based on the total weight of the components (A) and (B), and - 0 to 10 parts of optionally additives (D). In one embodiment, the composition includes an additive (E) selected from an adhesion enhancing agent in an amount of 0.1 to 10 parts per weight related to 100 parts per weight of component (A).. In one embodiment, the adhesion enhancing agent is selected from a titanate compound. In one embodiment according to the invention the used silicone composition for potting application comprises: - 100 parts per weight of at least one linear polyorganosiloxane (A) having one alkenyl, preferably at least two alkenyl groups bonded to a silicon atom at each end, - 0.01 to 30 parts by weight of component (B) selected from the group of (B1) a linear SiH-containing polyorganosiloxane having one SiH group at each end and (B2) a branched SiH-containing polyorganosiloxane consisting of at least one M H unit and at least one Q unit, - 0.1 to 3.5 weight percent of at least one photo-activatable hydrosilylation catalyst (C1) based on total weight of (A) and (B), - 1 to 1000 ppm at least one non-photo-activatable hydrosilylation catalyst (C2) based on the total weight of the components (A) and (B), and - 0 to 10 parts of optionally additives (D). - 0 to 10 parts of an adhesion enhancing agent (E) selected from titanate compounds. In one embodiment, the above silicone composition has a viscosity below 10000 mPa.s, preferably below 8000 mPa.s, more preferably below 5000 mPa.s at 20°C and D=10 s -1 according to DIN 53019. In another embodiment, the above silicone composition has a viscosity below 1000 mPa.s, preferably below 800 mPa.s, more preferably below 500 mPa.s at 20°C according to DIN 53015. In another embodiment according to the invention, the curable silicone composition which comprises: - 100 parts per weight of at least one linear polydiorganosiloxane (A) having one alkenyl group bonded to a silicon atom at each end of the formula wherein each R is independently selected from saturated organic groups, preferably methyl, each R 1 is independently selected from alkenyl groups, preferably vinyl groups, and x is ≥ 0. - 0.01 to 30 parts by weight of component (B) selected from the group of (B1) a linear SiH-containing polydiorganosiloxane having one SiH group at each end of formula
wherein R is independently selected from saturated organic groups, and one R 3 is H and remaining R 3 groups are R groups independently selected from saturated organic groups and p ≥ 0 and q = 0 and (B2) a branched SiH-containing polyorganosiloxane consisting of M H units and Q units, - 0.1 to 3.5 weight percent of at least one photo-activatable hydrosilylation catalyst (C1) (alkyl- cyclopentadienyl) Pt (alkyl)3, preferably the alkyl group is methyl based on total weight of (A) and (B), - 1 to 1000 ppm at least one non-photo-activatable hydrosilylation catalyst (C2) selected from the group of hexachloloroplatinic and alkenylsiloxane complexes of platinum based on the total weight of the components (A) and (B), and - optionally 0.1 to 10 parts of (D1) to (D3), preferably (D1) of formula (3c). - 0.1 to 10 parts of adhesion enhancing agent (E) based on titanate compounds. - optionally 0 to 10 parts of compound (D) as UV tracer selected from the group of benzoxazole compound and/or a bis-benzoxazole compound and/or a thiophenediyl benzoxazole compound and/or thiophenediyl bis-benzoxazole compound. In another embodiment, the above silicone composition has a viscosity below 1000 mPa.s, preferably below 800 mPa.s, more preferably below 500 mPa.s at 20°C measured according to DIN 53015. This silicone composition exhibits adhesion to the surface of the chamber/cavity/mold of the electronic component. In still another embodiment, the curable silicone composition is provided as a kit of 2 components system (part A and part B mixed as a 1 to 1 weight ratio) as the potting application requires flowing of the curable silicone composition and a quick curing before the next steps of the process (turning upside down of the electronic component etc). Excellent mechanical properties are obtained for this kind of curable silicone composition. The present compositions can be employed as potting and encapsulation materials suitable for protecting electrical and electronic components from environmental stresses and other stresses. The curable silicone composition of the current invention is used, for example, as material for potting on integrated circuits in a chamber/cavity/mold in electronic devices as a potting compound in potting and encapsulation of electronic components in automotive, power applications for the protection against moisture, dust and environmental hazards. Potting is the process of filling a complete mechanical or electronic assembly with a liquid material that is subsequently cured with moisture, UV light, and/or thermal energy. Typically, the potting material is dispensed into a plastic housing (chamber), pocket (cavity), or case (mold) where the electronic unit is placed. In potting applications, the silicone composition flows over and around a component or fills in a chamber/cavity/mold to protect components therein. Examples include heavy duty electrical cords and connectors, electronics in plastic cases, circuit boards and concrete repair. Encapsulation includes building a frame or dam around an objection, e.g., wires, passive components, etc., and filling the space with a liquid material between the frame and the object and subsequently curing the material with moisture, UV light, and/or thermal energy. In one embodiment according to the invention, a process of curing the curable silicone composition to a cured silicone composition in a chamber/cavity /mold having areas not readily accessible to direct UV light irradiation, comprises the steps: a) applying the said curable silicone composition to the chamber/cavity/mold in a manner so as to cover both the light accessible and the areas not readily accessible to direct UV light, b) irradiating 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 a temperature of ≥ 20°C for sufficient time to cure the composition in the areas not accessible to UV light. The areas not accessible to UV light are also named here shadow areas. A cured product is obtained by exposing the curable silicone composition according to the invention to irradiation, preferably to UV light to perform hydrosilylation reaction and in parallel a non-photoactivatable hydrosilylation reaction. In one embodiment according to the invention, the process of curing of the curable silicone compositions to a cured silicone composition for the manufacture of connector potting, the process comprising the steps: a. applying said curable silicone composition to a chamber/cavity /mold with connectors, b. exposing said curable silicone composition to UV light c. then curing in areas not accessible to UV light in a temperature range of 20 to 80°C. In one embodiment according to the invention, the process of curing of the curable silicone compositions to a cured silicone composition for the manufacture of connector potting, the process comprising the steps: b. exposing said curable silicone composition to UV light for less than five minutes, preferably less than one minute, c. then curing in areas not accessible to UV light in a temperature range of 20 to 80°C. In another embodiment, the invention related to an article prepared by the steps comprising: I. mixing, so as to form a curable composition as described above II. applying a potting of/dispensing said curable composition to a chamber/cavity /mold; and III. curing said curable composition to said chamber/cavity /mold by exposing said silicone composition in the potting containing chamber/cavity /mold to a source of UV radiation and thereafter to a non-photoactivatable curing. In a preferred embodiment of the process according to the present invention the silicone composition is curable upon photoactivation for a period of 0.01 to 300 sec. Photoactivation is carried out with light of a wavelength in the range of 200 to 450 nm (UV light). In the process according to the present invention an UV radiation source for the light activation is chosen, for example, from the group of UV lamps such as xenon lamps which can be operated as flash lamps, undoped mercury lamps or mercury lamps doped with iron or gallium, black light lamps and excimer lamps as well as LED UV lamps. The total amount of exposure at a wavelength of 365 nm is preferably in a range from 100 mJ/cm 2 to 10 J/cm 2 . The wavelength used to cure the curable silicone composition of the current invention is not narrowly limited as long as the wavelength is capable to cure the composition within a reasonable timescale. The photoactivation curing is followed by a non-photoactivated curing in a temperature range of 20 to 80°C for a period of 0.5 to 2 hours to allow the curing of the silicone composition in the areas not accessible to UV light. The use of a two component addition curable system (kit of a part A and part B) allows a quicker curing with some time to dispense the composition in the mold which is convenient for the potting application. In one embodiment, the invention provides a process of curing the curable composition by the process comprising accelerating the curing in the temperature range from 20 to 80°C. In one embodiment, the invention also provides a cured composition prepared by the process of curing the inventive curable silicone composition with a UV intensity of 0.5 J/cm² to 20 MJ/cm² followed by curing in the temperature range of 20 to 80°C. In one embodiment the cured composition has a hardness in penetration range 20 to 8010/mm tested with 1/4 cone according to DIN 51579 and in another embodiment thehardness is in Shore 00 range of 0 to 70 according to ASTM D2240 - 2015. The electronic components that the present compositions may be employed to protect are not particularly limited. Electronic components may include, for example, any type of PCB (printed circuit board) assemblies as well as switches and electronic connectors with pins. Typically, the electronic Potting materials according to the invention are used to protect entire or sometimes just certain areas of the circuit board assemblies for engine and/or transmission control units, electronic power steering units, power supplies or transformers and chassis and safety related electronic control units (e.g. ABS, ESP, etc). The other applications are related to electronic connectors. A connector typically consists of a plastic housing (engineered plastic such as PBT, PPS, ABS etc) and metal connector pins. Connector potting applications are prevalent in many applications, ranging from automotive, telecommunication, military, aerospace, and consumer-electronics. Power electronics and power modules applications. In particular potting and encapsulation of IGBT (Insulated Gate Bipolar Transistor) modules. IGBT modules have been developed to be used as switching elements for the power converters of variable-speed drives for motors, uninterruptable power supplies, and others. An IGBT is a semiconductor device that combines the high-speed switching performance of a power MOSFET () with the high-voltage/high-current handling capabilities of a bipolar transistor. The main function of our silicone material according to the invention in this IGBT application is to provide electrical insulation of the wires and high voltage areas in the module to prevent arcing or a short circuit. Typically connector pins are mounted in/ through the plastic housing of the connector. As the pins are reaching through the plastic housing and as there is a small gap due to production tolerances between the metal connector pin and the plastic housing, proposed silicone composition as potting material acts a barrier to prevent water ingress. The potting material is dispensed into the connector, filling the cavity by flowing into the gaps. After filling and flowing, the material is cured with exposure to UV light. As there are areas below the connector pins which might not get exposed to UV light; “so called shadow areas” a second cure mechanism without UV is required. In addition, the silicone composition as cured material according to the invention will provide one or more of the following: (a) long term stability over a broad temperature range, (b) retention of flexibility, adhesion, and/or sealing even in extreme conditions, (c) permanent flexibility and low cure shrinkage for stress relief, (d) low stress and non-cracking, (e) ability to withstand exposure to vibration, impact and shock, (f) exceptional durability (g) excellent thermal shock resistance, (h) exceptional moisture protection, (i) minimal expansion and contraction with temperature changes, (j) excellent electrical insulation properties for use with sensitive circuits, (k) low volatile solutions, (l) customizable cure rates allowing the material to match the assembly process, and/or (m) wide range of viscosities – from semi- flowable to flowable liquids. What has been described above includes examples of the present specification. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present specification, but one of ordinary skill in the art may recognize that many further specification is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim. The foregoing description identifies various, non-limiting embodiments of a silicone composition, processes for curing such compositions, and the use of such compositions in various applications. Modifications may occur to those skilled in the art and to those who may make and use the invention. The disclosed embodiments are merely for illustrative purposes and not intended to limit the scope of the invention or the subject matter set forth in the claims. EXAMPLES Example 1 & Example 2 Silicone compositions were obtained by mixing part A and B (as displayed in Table 1 below, for Example 1 and Example 2) at a weight ratio 1:1 for each corresponding example. The two silicone compositions (of Example 1 and Example 2) differ by the absence (Example 2) or the presence (Example 1) ) of the UV tracer MPI Bright 100. The UV tracer is used for leaks detection or seal defects detection. The UV tracer is added after the blending of part A with part B. The work life at 23°C corresponds to the time to get the doubling of the initial viscosity of the final silicone rubber composition (A+B) of corresponding example. The silicone composition mixture of the Example is then irradiated first by a metal halide Lamp with a UV intensity for green strength of 4.5. Table 1 Compositions of the invention for preparing samples as in Example 1 and 2
Silicone composition of each of the examples (Example 1 and Example 2) was cured in two ways as follows: - 45 sec with a UV radiation of 100 mW/cm 2 (UV Curing 4.5 J/cm 2 ) - Non photocurable curing at 23°C for the shadow areas. (The UV curing is also possible with UV LED at 365 nm with a UV intensity for green strength of 24 – 9 s with a UV radiation of 500mW/cm2 corresponding to 4.5 J/cm 2 .) Table 2: Attributes of uncured and cured samples of the compositions (Example 1 and Example 2) of the invention 1) Time to double viscosity The Lap shear of the cured silicone compositions according to the invention was measured on different substrate combinations for Ex 1 and Ex 2. Substrate combination: glass/other substrate Bond line thickness between the 2 substrates: 100 µm Dual cure conditions: UV radiation 45 s 100 mW/cm 2 plus 16 hours at 23°C (non photo-activatable curing) Table 3: Lap shear strength and cohesive failure of the compositions (Example 1 and Example 2) of the invention Lap shear (DIN Norm EN 1465) was used to measure the strength of the adhesive properties under shear strength. (see https://leitfaden.klebstoffe.com/en/6-5-1-leap-shear-test/) The substrate combination glass/used silicone composition according to the invention/ PBT- GF30FR Ultradur B4300 G6 HR has the highest value for lap shear and the highest percentage of cohesive failure indicating that the adhesive is very suitable for this substrate combination. Ageing tests at 85°C/85% relative humidity (r.h.) were performed to see the effect on the lap shear adhesion of the silicone composition of Ex 1 or Ex 2 For the testing, following conditions were used: - Substrate combination used: glass/PBT (GF30 Ultradur B4315 G6 HR from BASF) - Bond line thickness : 100 µm - Curing conditions: UV radiation 45 s 100 mW/cm 2 and parallel non photo-activatable Table 4: Lap shear strength upon ageing, of the composition (Example 1) of the invention The silicone adhesive of Ex 1 or 2 shows 40% variation in the Lap shear strength after ageing at 85°C/85% relative humidity (r.h.), which is suitable for the potting application. The hardness buildup was measured for the inventive Ex 1 with 2 different UV sources. Table 5a : Hardness buildup after UV curing of inventive example Ex 1 with UV source being the hand-held lamp (housing holding the metal halide tube, reflector, safety thermostat, cooling fan, frame with blue filter) UV-H 255 Panacol 100 mW/cm² Table 5b : Hardness buildup after UV curing of Ex 1 with UV source being Hönle LED Spot 100HP K 365nm (1000 mW/cm 2 ). The above compositions are suitable for potting application because - they are easily pourable and filling of small cavities due to their low viscosity (about 220 mPa.s at 20°C according to DIN 53015). - they ensure after curing tightness against outside media. Examples 3 and 4 The silicone composition mixture of Example 3 or 4 (the composition of which is displayed in table 5 below) was irradiated first by a metal halide Lamp with a UV intensity for green strength of 4.5 and cured as follows: - 45 sec with a UV radiation of 100 mW/cm 2 (UV Curing 4.5 J/cm 2 ) Alternatively, UV LED at 365 nm with a UV intensity for green strength of 24 for 9 s and a UV radiation of 500 mW/cm 2 ) is used Table 5: Attributes of the composition (Example 3 and Example 4) of the invention The cohesive failure is measured using OverLapShear (OLS) Test and Failure Modes with an Instron device on a cured sample using a test substrate size 25mm x 10cm, a bond area 25mm x 25mm x 1mm and crosshead pull speed 10mm/min.100% cohesive failure means the silicone adhesive has broken in itself due to very good adhesion to substrate . As shown in Table 5, Ex 3 does not contain the tetra-n butyltitanate (E) and after irradiation by UV there is a big difference in the percentage of cohesion of failure for two different substrates like Aluminum 5754 or on PBT -GF30FR Ultradur B4300 G6 HR. These experiments display that in the presence of tetra-n butyltitanate there is a surprising increase of adhesion of the composition on substrates such as aluminum and PBT. The percentage of cohesion failure is 100% for Ex 4 indicating a surprisingly strong adhesion between the substrate (either Aluminium or PBT) and the silicone composition of Ex.4. The composition of the invention provides complete curing-by UV and shadow curing in addition to suprisingly enhancing adhesion on low energy substrates such as Al and PBT. Such enhancement in adhesion is presumably accelerated by a co-operative involvement of the metal (titanate) compound along with the UV-activated curing catalyst, which is hitherto unknown. The curing observed for the examples 3 and 4 was of the same quality with the same value of hardness i.e., 40 shore 00. Example 5: Use of a two components inventive silicone composition of Example 1 in a connector assembly: Automotive electrical connectors are specifically designed for use in automobile electrical systems. Automobile systems have undergone massive transformation and today modern systems are extensively wired and controlled by a microprocessor. This has increased the demand for high-quality and reliable wiring and electrical connectors. Typically connector pins are mounted in/ through the plastic housing of the connector. As the pins are reaching through the plastic housing and as there is a small gap due to production tolerances, between the metal connector pin and the plastic housing, our silicone material acts a barrier to prevent water ingress. The potting material as a two part inventive silicone composition of Example 1 (part A and part B were mixed at a weight ratio of 1:1) is dispensed into the connector, filling the cavity by flowing into the gaps. After filling and flowing, the inventive silicone composition of Example 1 was cured with exposure to UV light as indicated in Table 1. As there are areas below the connector pins which were required. The non-photoactivatable catalyst was acting for curing at room temperature and after 1 hour the cured silicone composition had a hardness shore 00 of 40 very close to the final hardness. The connector was then further processed.