WO2015061075A1

WO2015061075A1 - Cured silicone with high light transmittance, curable silicone for preparing same, devices and methods

Info

Publication number: WO2015061075A1
Application number: PCT/US2014/060356
Authority: WO
Inventors: Stanton J. DENT; Joel Patrick MCDONALD; Emil Radkov; Wei RONG; Michael Raymond STRONG; Shengqing Xu
Original assignee: Dow Corning Corporation
Priority date: 2013-10-24
Filing date: 2014-10-14
Publication date: 2015-04-30
Also published as: TW201527436A

Abstract

A non-resinous curable polyorganosiloxane composition consisting essentially of non-resinous ingredients that comprise non-resinous ingredients (A), (B), (C), and (D): (A) a first polyorganosiloxane polymer containing vinyl groups only on terminal ends of the first polyorganosiloxane polymer, only on pendant positions of the first polyorganosiloxane polymer, or on terminal ends and pendant thereon (i.e., some on terminal ends and others pendant thereon); (B) a multivinyl-functional silicon monomer for forming cluster crosslinks; (C) a SiH functional crosslinker; and (D) a curing reaction catalyst. A cured polyorganosiloxane, free-standing light guide, composite light guide, optoelectronic devices, and luminaires prepared therefrom. A method of transmitting light.

Description

CURED SILICONE WITH HIGH LIGHT TRANSMITTANCE, CURABLE SILICONE FOR PREPARING SAME, DEVICES AND METHODS

[0001] This invention generally relates to a cured silicone with high light transmittance, a curable silicone for preparing same, and devices prepared therefrom, and methods of using the devices.

[0002] US 5,574,073 to Juen, D. R., et al. mentions curable silicone compositions which provide high strength foams or elastomers. These foams or elastomers have high strength properties which are provided by a combination of non-resinous organopolysiloxanes as the base polymer. The high strength properties are better than the high strength properties of cured silicone compositions where only one non-resinous organopolysiloxane polymer type is employed. These compositions have the added benefit of being less expensive than resin based formulations.

[0003] US 6,926,952 B1 to Weber, M. F., et al. mentions articles, including free-standing films, comprising a base comprising a polymer layer having a major surface; and an anti- reflective stack optically coupled to the base that reduces the reflectivity of the base at over a first wavelength range of interest. The anti-reflective stack comprises alternating layers of (i) high index polymer; and (ii) low index polymer. Methods of making such articles are also provided.

[0004] US 6,983,093 B2 to Fraval, H. R., et al. mentions a light guide that includes a flexible elongated tube having an inner surface and first and second ends. A non-supercritically dried hydrophobic aerogel film is affixed to the inner surface of the tube as a cladding layer, and a fluid core is disposed within the tube. The fluid core has a refractive index greater than the refractive index of the aerogel cladding film.

[0005] US 201 1 /0203664 A1 to Howell, M., et al. mentions a photovoltaic cell module, a photovoltaic array including at least two modules, and a method of forming the module. The module includes a first outermost layer and a photovoltaic cell disposed on the first outermost layer. The module also includes a second outermost layer disposed on the photovoltaic cell and sandwiching the photovoltaic cell between the second outermost layer and the first outermost layer. The method of forming the module includes the steps of disposing the photovoltaic cell on the first outermost layer, disposing a silicone composition on the photovoltaic cell, and compressing the first outermost layer, the photovoltaic cell, and the second layer to form the photovoltaic cell module.

[0006] JP 2012-024545 A, based on a machine-generated English translation thereof obtained from the JPO, mentions a device includes a body part for covering an external surface of an insert part with a diameter of approximately 1 mm, and a light guide part. The body part is formed by an ultrafine tube made from elastomer of a flexible polyamide group as material. The light guide part is formed by transparent thermosetting silicone rubber and has translucency. When the light guide part is molded, the light guide part and the body part are integrated by inserting an end part of the body part into a molding die. An exterior surface shape of the light guide part when being molded is defined by the molding die, while an interior shape is defined by the body part and a soluble inner component loaded in advance inside the end part of the body part. After demolded (sic), the soluble inner component is melted and removed by heated water.

[0007] We (the present inventors) have discovered or recognized technical problems with prior silicones used as light guides that are not solved by the art. Some light guides require resinous silicones for mechanical strength, but we found that resinous silicones absorb and/or scatter visible light, rendering them unsuitable for efficiently transmitting visible light. The longer the distance of transmittance, the more unsuitable resinous silicones become. Other prior silicones, non-resinous silicones (e.g., rubbers and liquids) lack mechanical strength and, if they are to be used as light guides, must be confined in two dimensions, or even contained in three dimensions.

[0008] Therefore, we desired to find light guides with high light transmittance, and so we conceived the inventive technical solution described herein.

BRIEF SUMMARY OF THE INVENTION

[0009] This invention comprises a cured silicone with high light transmittance, a curable silicone for preparing same, and devices prepared therefrom, and methods of using the devices. Embodiments of the invention include:

[0010] A non-resinous curable polyorganosiloxane composition consisting essentially of non-resinous ingredients that comprise non-resinous ingredients (A), (B), (C), and (D): (A) a first polyorganosiloxane polymer containing vinyl groups only on terminal ends of the first polyorganosiloxane polymer, only on pendant positions of the first polyorganosiloxane polymer, or on terminal ends and pendant thereon (i.e., some on terminal ends and others pendant thereon); (B) a multivinyl-functional silicon monomer for forming cluster crosslinks; (C) a SiH functional crosslinker; and (D) a curing reaction catalyst.

[0011] A cured polyorganosiloxane comprising a reaction product of curing the non-resinous curable polyorganosiloxane composition.

[0012] A free-standing light guide comprising the cured polyorganosiloxane. [0013] A composite light guide comprising the cured polyorganosiloxane disposed on a support.

[0014] An optoelectronic device comprising the free-standing light guide or composite light guide and at least one light element, wherein the free-standing light guide or composite light guide is configured to transmit light when light is emitted from the light element.

[0015] A luminaire comprising the optoelectronic device and a power supply that is configured for powering the at least one light element.

[0016] A method of transmitting light comprising visible light to a light-receiving element via any one of the light guides.

[0017] The non-resinous curable polyorganosiloxane composition is useful for preparing the cured polyorganosiloxane, which is useful as a free-standing light guide or with a support.

Each light guide is useful in the optoelectronic device, which is useful in the luminaire. The invention may have additional uses, including those unrelated to lighting applications for illuminating a surface or space.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Embodiments of the invention and certain advantages may be illustrated and described by referring to the accompanying drawings.

[0019] Figure (Fig.) 1 shows an embodiment of a free-standing light guide that is guiding light.

[0020] Fig. 2 shows a graph of the percent transmittance expressed as a fraction versus light wavelength for a comparative example of 100.0 millimeter (mm) thickness and for an inventive example of 100.0 mm thickness.

[0021] Fig. 3 shows a graph of the percent transmittance expressed as a fraction at a light wavelength of 400 nanometers (nm) versus sample thickness for a comparative example and for an inventive example.

[0022] Fig. 4 shows a graph of the percent transmittance expressed as a fraction versus light wavelength for a comparative example of 8.70 mm thickness and for inventive examples of 9.18 mm thickness, 9.15 mm thickness, and 9.20 mm thickness.

[0023] Fig. 5 shows a graph of reflectivity-corrected percent transmission expressed as a fraction versus visible light wavelength for a comparative example and for an inventive example of 3.85 mm thickness. DETAILED DESCRIPTION OF THE INVENTION

[0024] The Brief Summary and Abstract are incorporated here by reference. The invention includes, but is not limited to, the embodiments summarized above. The inventive cured polyorganosiloxane lacks resinous silicones and yet has mechanical strength. The cured polyorganosiloxane also does not scatter visible light, has high transmission of light comprising visible light as described later and/or has low haze as described later. This combination of properties renders the cured polyorganosiloxane suitable for forming light guides, including free-standing light guides, that efficiently transmit light comprising visible light, including transmitting the light through the light guide having a long optical pathway as described later.

[0025] The invention has technical and non-technical advantages. We found that the inventive light guide may be used free standing or with a support and enables more efficient transmission of light comprising visible light. We believe the combination of technical features create a beneficial balance between mechanical strength and high transmission of light comprising visible light as described later is unique in the silicone art. By omitting resinous polyorganosiloxanes and agglomerates thereof from the non-resinous curable polyorganosiloxane composition, and thus from the cured polyorganosiloxane, we have prevented their disadvantageous light-scattering (e.g., Rayleigh scattering and Mie scattering) and, thus increased the efficiency of transmission of light comprising visible light therethrough. Further, by employing only linear polyorganosiloxanes (i.e., straight chain, branched chain, or both) and limiting the concentration of long polyorganosiloxane chains by limiting number average molecular weight (M_n) or degree of polymerization (DP) thereof, we have further prevented disadvantageous light-scattering (e.g., Rayleigh scattering) and, thus further increased the efficiency of transmission of light comprising visible light therethrough. These features by themselves, however, gave a material (e.g., a gel) with an unacceptable loss of mechanical strength. Fortunately, we were able to restore mechanical strength without loss of the gain in transmission efficiency for light comprising visible light and arrive at the present technical solution by also formulating the non-resinous curable polyorganosiloxane composition in such a way that upon curing same the resulting cured polyorganosiloxane advantageously contains cluster crosslinks. Noteworthy, the cured polyorganosiloxane advantageously does not cure, and is not cured, to such an extent that it forms resin structures as in T and Q resins as defined later. At any given mechanical strength and length of the optical pathway defined therein, the percent transmission of visible light (e.g., from 375 to 725 nanometers (nm), alternatively from 400 to 700 nm, alternatively 400 nm, alternatively 700 nm) through the cured polyorganosiloxane may be greater than (>) the percent transmission of visible light along an equal length optical pathway in a resinous polyorganosiloxane having the same mechanical strength and lacking cluster crosslinks. Certain aspects of this invention may independently solve additional problems and/or have other advantages.

[0026] As used herein, "may" confers a choice, not an imperative. Optionally" means is absent, alternatively is present. "Contacting" means bringing into physical contact. "Operative contact" comprises functionally effective touching, e.g., as for modifying, coating, adhering, sealing, or filling. The operative contact may be direct physical touching, alternatively indirect touching. All U.S. patent application publications and patents referenced herein, or a portion thereof if only the portion is referenced, are hereby incorporated herein by reference to the extent that incorporated subject matter does not conflict with the present description, which would control in any such conflict. All % are by weight unless otherwise noted. All "wt%" (weight percent) are, unless otherwise noted, based on total weight of all ingredients used to make the composition, which adds up to 100 wt%. Any Markush group comprising a genus and subgenus therein includes the subgenus in the genus, e.g., in "R is hydrocarbyl or alkenyl," R may be alkenyl, alternatively R may be hydrocarbyl, which includes, among other subgenuses, alkenyl. The term "silicone" includes linear, branched, or a mixture of linear and branched polyorganosiloxane macromolecules.

[0027] As used herein, the term "cluster crosslink" is a unit or segment at which 3 or more polyorganosiloxane chains come together. For example, the cluster crosslink may be a unit to which 3 or 4 polyorganosiloxane chains are covalently bonded. The unit may be thought of as a pseudo node. Alternatively, the cluster crosslink may be a segment containing a plurality of same or different units. To which segment 4, alternatively 5, alternatively from 6 to 8, alternatively 9 to 20 polyorganosiloxane chains may be covalently bonded. The polyorganosiloxane chains may be covalently bonded directly or indirectly to a same central atom in the unit (in embodiments with 3 or 4 chains) or to two or more different atoms in the segment (in embodiments with 4, alternatively 5, alternatively from 6 to 8, alternatively 9 to 20 polyorganosiloxane chains). The cluster crosslink may have a formula weight from > 280 to < 2,000 grams per mole (g/mol), alternatively from 280 to 1 ,500 g/mol, alternatively from 280 to 1 ,200 g/mol, alternatively from 1 ,200 to 2,000 g/mol, alternatively from 1 ,500 to 2,000 g/mol. Alternatively, the molecular weight may be from > 400 to < 1 ,200 g/mol, alternatively from 432 to < 1 ,200 g/mol, alternatively from 600 to 1 ,200 g/mol, alternatively from 700 to < 1 ,200 g/mol, alternatively from > 400 to < 1 ,000 g/mol, alternatively from 432 to < 1 ,000 g/mol, alternatively from 600 to 1 ,000 g/mol, alternatively from 700 to < 1 ,000 g/mol. The formula weight of the cluster crosslink may be the same as the molecular weight of ingredient (B), the multivinyl-functional silicon monomer, described later. The invention employs the cluster crosslinks in the cured polyorganosiloxane at a crosslink density that is high enough for satisfactory mechanical strength without embrittlement (e.g., elongation-at- break or tensile strength), and yet low enough for preventing or minimizing light scattering and thereby retaining an increase in transmission efficiency for light comprising visible light (e.g., reflectivity-corrected transmittance of light from 375 to 725 nm, alternatively from 400 to 700 nm, alternatively 400 nm, alternatively 700 nm). Alternatively or additionally, transmission efficiency for light other than visible light may be increased.

[0028] The term "light element" means a component or device that characteristically functions during operation of the luminaire to emit (i.e., generate and release), sense, guide, optically couple, split, or filter light. The light element may be a light-generating element (light emitting diode) or a light-receiving element (e.g., a sensor). For purposes of the present description, the light element(s) are distinct from and in addition to the light guides.

[0029] The term "light extraction" means getting light from one location to a surrounding location.

[0030] The term "light guide" means a free-standing or a supported material (e.g., in a composite material) for transmitting or propagating light. The composite material comprises a light guide disposed on a support. The free-standing and composite light guides may be collectively referred to herein as light guides. A light guide typically comprises a surface portion adapted for receiving light to be propagated, another surface portion adapted for reflecting light as it is being propagated within the light guide, and still another surface portion adapted for extracting the propagated light from the light guide. The light being received (from a light source), propagated, and extracted by the light guide may be composed of a single wavelength or, typically, of a spectrum of wavelengths.

[0031] As used herein, the terms "light transmission" and "light transmittance" are used interchangeably and have the same meaning. Transmitted light is light that has traveled through a medium without being absorbed or scattered.

[0032] The term "non-resinous" and the phrase "composition consisting essentially of non- resinous ingredients that comprise non-resinous ingredients," in describing the curable polysiloxane composition and cured polyorganosiloxane prepared by curing same, means lacking optical characteristics of a polyorganosiloxane resin. For example, non-resinous may mean having a weight average molecular weight (M_w) > 3,000 g/mol and having less than (<) 33 mole percent (mol%) of a total of T and Q units, alternatively < 20 mol%, alternatively < 10 mol%, alternatively < 5 mol%, alternatively 0 mol%, i.e., lacking both T and Q siloxane units; or having a M_w from 100 to < 3,000 g/mol and from 0 to 4 total T and Q units, alternatively 0 to 3 total T and Q units, alternatively 0 to 2 total T and Q units, alternatively 2 total T and Q units, alternatively 1 total T and Q units, alternatively 0 total T and Q units. If there are T or Q units, there may be just T unit(s), alternatively just Q unit(s), alternatively at least 1 T unit and at least 1 Q unit so long as the total T and Q units is < 4. For example, the curable polysiloxane composition and cured polysiloxane may have 1 Q unit and 0 T units, alternatively 1 T unit and 0 Q units, alternatively 1 Q unit and 1 T unit, alternatively 0 Q units and 0 T units, alternatively 2 Q units and 0, 1 or 2 T units, alternatively 2 T units and 0, 1 or 2 Q units. M and D units may also be present in the curable polysiloxane composition and cured polyorganosiloxane prepared by curing same. E.g., the curable polysiloxane composition and cured polyorganosiloxane prepared by curing same may have only MQ units, MT units, MDT units, or T units. The M siloxane units may be represented by the formula R^M3SiO-|/2, wherein each R^M independently is H or any small monovalent organic group and the Si of the M unit is bonded to carbon atoms of the R^M groups. The D siloxane units may be represented by the formula R^SiC^, wherein each R^D independently is H or any small monovalent organic group and the Si of the D unit is bonded to carbon atoms of the R^D groups. The T siloxane units may be represented by the formula R^TSi03/2, wherein R^T is H or any small monovalent organic group and the Si of the T unit is bonded to a carbon atom of the R^T group. The Q siloxane units may be represented by the formula S1O4/2. The small monovalent organic group has a formula weight < 280 g/mol, alternatively < 200 g/mol, alternatively < 150 g/mol. The small monovalent organic group may be (C-| -C2rj)hydrocarbyl, alternatively (C-| -C-| 5)hydrocarbyl, alternatively (C-| -C-| o)hydrocarbyl, alternatively (C-| -Cg)hydrocarbyl. Illustrative examples of hydrocarbyl are alkyl, alkenyl, alkynyl, and aryl.

E.g., the (C-| -C6)hydrocarbyl may be (C-| -Cg)alkyl, (C2-Ce)alkenyl, (C2-Ce)alkynyl,

(C3-Cg)cycloalkyl, or phenyl. The small monovalent organic group may be unsubstituted or substituted. Mol% M, D, T and Q units may be determined with ²9Si-nuclear magnetic resonance. Again, the cured polyorganosiloxane advantageously does not cure, and is not cured, to such an extent that it forms resin structures as in T and Q resins as defined hereabove for. [0033] The inventive non-resinous curable polyorganosiloxane composition may be illustrated by describing below a non-resinous hydrosilylation-curable polyorganosiloxane composition in greater detail. The non-resinous curable polyorganosiloxane composition is not limited to non-resinous hydrosilylation curable polyorganosiloxane compositions, e.g., it may be a non-resinous free radical-curable polyorganosiloxane composition instead, in which composition the hydrosilylation reaction catalyst would be replaced by a free radical generator such as an organic peroxide (e.g., benzoyl peroxide) or ultraviolet light. The aforementioned advantages and benefits of the invention apply to the non-resinous hydrosilylation-curable polyorganosiloxane composition, the hydrosilylation-cured polyorganosiloxane, the light guides, optoelectronic devices and the luminaires prepared therefrom.

[0034] The non-resinous hydrosilylation-curable polyorganosiloxane composition consists of non-resinous ingredients that may comprise non-resinous ingredients (A), (B), (C), and (D):

(A) a first polyorganosiloxane polymer having a weight average molecular weight of from 1 ,000 to 1 ,000,000 g/mol, alternatively from 1 ,000 to 120,000 g/mol, and containing vinyl groups only on terminal ends of the first polyorganosiloxane polymer or on terminal ends and pendant thereon (i.e., some on terminal ends and others pendant thereon), and having on average at least two vinyl groups per molecule and a pendant vinyl content, when present, of from 0.01 to 5 weight percent based on weight of ingredient (A);

(B) a multivinyl-functional silicon monomer containing from 3 or more vinyl groups up to per vinyl substitution and being an organosiloxane having a molecular weight of from 280 to 2,000 g/mol or being an organosilane having a molecular weight of from 124 to 2,000 g/mol;

(C) a silicon hydride (SiH) functional organosiloxane crosslinker having on average at least two SiH functional groups per molecule; and

(D) a hydrosilylation reaction catalyst;

wherein the total SiH-to-vinyl molar ratio of the non-resinous hydrosilylation-curable polyorganosiloxane composition is from 0.1 to 10, alternatively from 0.1 to < 10. For brevity the non-resinous hydrosilylation-curable polyorganosiloxane composition may be referred to herein as NRHCP Composition.

[0035] In the NRHCP Composition, the total SiH-to-vinyl molar ratio of the NRHCP Composition is from 0.1 to 10, alternatively from 0.1 to 5, alternatively from 0.1 to 2.5, alternatively from 0.5 to 10, alternatively from 0.5 to 5, alternatively from 0.5 to 2.5, alternatively from 0.8 to 10, alternatively from 0.8 to 5, alternatively from 0.8 to 2.5, alternatively 0.8 to 1 .5, alternatively > 0.8 to < 1 .5, alternatively from 0.9 to < 1 .5, alternatively 1 .0 to 1 .5, alternatively from 1 .0 to < 1 .5, alternatively from 0.9 to 1 .3, alternatively from 1 .0 to 1 .3, alternatively from 1 .0 to 1 .1 , e.g., 1 .06.

[0036] In the NRHCP Composition the vinyl groups of (A) the first polyorganosiloxane polymer may be only on terminal ends of the first polyorganosiloxane polymer; alternatively only on pendant positions of the first polyorganosiloxane polymer, alternatively some the vinyl groups of ingredient (A) may be pendant on and others on terminal ends of the first polyorganosiloxane polymer. The pendant vinyl content, when present, may be from 0.01 to 4 wt%, alternatively from 0.01 to 2 wt%, alternatively from 0.01 to 1 wt%, alternatively from 0.01 to 0.8 wt%, alternatively from 0.01 to 0.40 wt%, alternatively from 0.01 to 0.20 wt%, alternatively from 0.05 to 0.8 wt%, alternatively from 0.05 to 0.40 wt%, alternatively from 0.05 to 0.20 wt%, alternatively from 0.1 to 0.80 wt%, alternatively from 0.10 to 0.40 wt%, alternatively from 0.10 to 0.20 wt%, all based on weight of ingredient (A). The first polyorganosiloxane polymer may consist of only linear molecules, which may be straight chain or branched chain. The first polyorganosiloxane polymer may consist of only straight chain linear molecules. The vinyl groups of (A) the first polyorganosiloxane polymer may be only on terminal ends of the first polyorganosiloxane polymer and the first polyorganosiloxane polymer may consist of only straight chain linear molecules. The first polyorganosiloxane polymer may have a M_w of from 1 ,000 to 1 ,000,000 g/mol, alternatively from 1 ,000 to 120,000 g/mol, alternatively from 1 ,000 to 100,000 g/mol, alternatively from 1 ,000 to 75,000 g/mol, alternatively from 1 ,000 to 50,000 g/mol, alternatively from 2,000 to 120,000 g/mol, alternatively from 2,000 to 100,000 g/mol, alternatively from 2,000 to 75,000 g/mol, alternatively from 2,000 to 50,000 g/mol, alternatively from 5,000 to 120,000 g/mol, alternatively from 5,000 to 100,000 g/mol, alternatively from 5,000 to 75,000 g/mol, alternatively from 5,000 to 50,000 g/mol, alternatively from 6,000 to 120,000 g/mol, alternatively from 6,000 to 100,000 g/mol, alternatively from 6,000 to 75,000 g/mol, alternatively from 6,000 to 50,000 g/mol, alternatively from 7,000 to 120,000 g/mol, alternatively from 7,000 to 100,000 g/mol, alternatively from 7,000 to 75,000 g/mol, alternatively from 7,000 to 50,000 g/mol. The first polyorganosiloxane polymer may be a vinyl-terminated polydimethylsiloxane lacking (without) pendant vinyl groups, alternatively a vinyl-terminated polydimethylsiloxane also having pendant vinyl groups, alternatively a vinyl- terminated polydimethyl,methylphenyllsiloxane lacking pendant vinyl groups, alternatively a vinyl-terminated polydimethyl,methylphenylsiloxane also having pendant vinyl groups, alternatively a vinyl-terminated polydiphenylsiloxane lacking pendant vinyl groups, alternatively a vinyl-terminated polydiphenylsiloxane also having pendant vinyl groups. A polydimethyl,methylphenylsiloxane generally is a polydiorganosiloxane having (CH3)2Si02/2 and (CH3)(phenyl)Si02/2 repeat units. The pendant vinyl content, when present, is described above. The ingredient (A) the first polyorganosiloxane polymer may be a single type of molecule or structure, alternatively (A) the first polyorganosiloxane polymer may be a combination of any two or more (e.g., two) different said molecules that differ in at least one of the following properties: structure, viscosity, average molecular weight, siloxane units, and sequence.

[0037] In the NRHCP Composition ingredient (B) the multivinyl-functional monomer may have a vinyl content from 10 to 50 wt%, alternatively from 10 to < 50 wt%, alternatively from 10 to 40 wt%, alternatively from 10 to 30 wt%, alternatively from 10 to < 30 wt%, alternatively from 15 to 50 wt%, alternatively from 15 to < 50 wt%, alternatively from 15 to 40 wt%, alternatively from 15 to 30 wt%, alternatively from 15 to < 30 wt%, alternatively from 20 to 50 wt%, alternatively from 20 to < 50 wt%, alternatively from 20 to 40 wt%, alternatively from 20 to 30 wt%, e.g., 25 wt%, all based on weight of ingredient (B). The number of vinyl groups on average per molecule of the multivinyl-functional monomer is at least 3 up to per vinyl substitution. The number of vinyl groups on average per molecule of the multivinyl-functional monomer may be from 3 to 10, alternatively from 3 to 8, alternatively from 3 to 6, alternatively from 3 to 5, alternatively 3 or 4, alternatively from 4 to 10, alternatively from 4 to 8, alternatively from 4 to 6, alternatively 4 or 5, alternatively from 5 to 10, alternatively from 5 to 8, alternatively 5 or 6, alternatively 3, alternatively 4, alternatively 5, alternatively 6, alternatively 7, alternatively 8, alternatively 9, alternatively 10, alternatively per vinyl substitution, Per vinyl substitution means each terminal and pendant substitution position the multivinyl-functional monomer is substituted with vinyl group. The multivinyl-functional monomer may be an organosiloxane monomer or organosilane monomer. The ingredient (B) the multivinyl-functional monomer may be a single type of molecule or structure, alternatively (B) the multivinyl-functional monomer may be a combination of any two or more (e.g., two) different said molecules that differ in at least one of the following properties: structure, viscosity, average molecular weight, siloxane units, and sequence.

[0038] The multivinyl-functional monomer may be an organosiloxane having a molecular weight from 280 to 2,000 g/mol, alternatively from 280 to 1 ,500 g/mol, alternatively from 280 to 1 ,200 g/mol, alternatively from 1 ,200 to 2,000 g/mol, alternatively from 1 ,500 to 2,000 g/mol. Alternatively, the molecular weight of the organosiloxane may be from 400 to 1 ,200 g/mol, alternatively from > 400 to < 1 ,200 g/mol, alternatively from 432 to 1 ,200 g/mol, alternatively from 432 to < 1 ,200 g/mol, alternatively from 600 to 1 ,200 g/mol, alternatively from 700 to 1 ,200 g/mol, alternatively from 700 to < 1 ,200 g/mol, alternatively from 400 to 1 ,000 g/mol, alternatively from > 400 to < 1 ,000 g/mol, alternatively from 432 to < 1 ,000 g/mol, alternatively from 600 to 1 ,000 g/mol, alternatively from 700 to 1 ,000 g/mol, alternatively from 700 to < 1 ,000 g/mol. The multivinyl-functional monomer may be an organosiloxane of formula (I): (H2C=CHR2SiO)4Si, wherein each R independently is (C-| -

Cg)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosiloxane of formula (II): (H2C=CHR2SiO)3Si-Si(OSiR2CH=CH2)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosiloxane of formula (III): (H2C=CHR2SiO)3Si-SiR2-Si(OSiR2CH=C 1-12)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. In any one of formulas (I) to (III) each R may be H2C=CH-, methyl or phenyl; alternatively methyl or phenyl, alternatively methyl. In some embodiments the multivinyl-functional monomer is an organosiloxane of formula (ll-a): (H₂C=CHR2SiO)3Si-0-Si(OSiR2CH=CH₂)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. In other embodiments the multivinyl-functional monomer may be an organosiloxane of formula (lll-a): (H2C=CHR2SiO)3Si-0-SiR2-0- Si(OSiR2CH=CH₂)3, wherein each R independently is (C-| -CeJalkyl, H₂C=CH-, or phenyl. In any one of formulas (ll-a) to (lll-a) each R may be methyl or phenyl; alternatively methyl or phenyl, alternatively methyl. Alternatively, at least one R may be ethyl, a propyl, a butyl, a pentyl, or a hexyl; alternatively at least one R may be ethyl, propyl, or 1 -methylethyl; alternatively at least one R may be ethyl.

[0039] Alternatively, the multivinyl-functional monomer may be an organosilane having a molecular weight of from 1 10 to 2,000 g/mol, alternatively from 1 10 to 1 ,500 g/mol, alternatively from 1 10 to 1 ,200 g/mol, alternatively 124 to 2,000 g/mol, alternatively from 124 to 1 ,500 g/mol, alternatively from 124 to 1 ,200 g/mol, alternatively from 280 to 2,000 g/mol, alternatively from 280 to 1 ,500 g/mol, alternatively from 280 to 1 ,200 g/mol. Alternatively, the molecular weight of the organosilane may be from > 300 to < 1 ,200 g/mol, alternatively from 340 to < 1 ,200 g/mol, alternatively from 400 to 1 ,200 g/mol, alternatively from 500 to < 1 ,200 g/mol, alternatively from > 600 to < 1 ,000 g/mol. The multivinyl-functional monomer may be an organosilane of formula (IV): (H2C=CHR2Si)4Si, wherein each R independently is

(C-| -Cg)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosilane of formula (V): (H₂C=CHR2Si)3Si-Si(SiR2CH=CH₂)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosilane of formula (VI): (H2C=CHR2Si)3Si-SiR2-Si(SiR2CH=C H₂)3, wherein each R independently is (C-| -Ce)alkyl, H2C=CH-, or henyl. The multivinyl-functional monomer may be an organosilane of formula (VII):

independently is a bond, a (C-| -Ce)alkylene or a phenylene. The multivinyl-functional monomer may be an organosilane of formula (VIII): (H2C=CHRAsi)3SiR, wherein each RA independently is a bond, a (C-| -C6)alkylene, or a phenylene; alternatively each RA independently is a (C-| -Cg)alkylene or a phenylene; and wherein each R independently is (C-i -Ce)alkyl, H2C-CH-, or phenyl. In any one of formulas (IV) to (VIII) each R may be (C-| -Cg)alkyl, H2C=CH-, or phenyl; alternatively H2C=CH-, methyl or phenyl; alternatively methyl or phenyl, alternatively H2C=CH-, alternatively methyl. The multivinyl-functional monomer may be an organosilane of formula (IX): (H2C=CHR2SiO)4Si, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosilane of formula (X): (H2C=CHR2Si)3Si-0-Si(SiR2CH=CH2)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosilane of formula (XI): (H₂C=CHR2SiO)3Si-0-Si(OSiR2CH=CH₂)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosilane of formula (XII): (H₂C=CHR2SiO)3Si-0-Si(SiR2CH=CH₂)3, wherein each R independently is (Ci -Ce)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosilane of formula (XIII): (H2C=CHR2SiO)3Si-SiR2-Si(SiR2CH=C 1^)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. The multivinyl-functional monomer may be an organosilane of formula (XIV): (H₂C=CHR₂SiO)₃Si-0-SiR2-0-Si(OSiR2CH=C H₂)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl. The multivinyl- functional monomer may be an organosilane of formula (XV): (H₂C=CHR2Si)3Si-0-SiR2-0-Si(SiR2CH=CH₂)3, wherein each R independently is (C-| -Ce)alkyl, H2C=CH-, or phenyl. Alternatively, at least one R may be ethyl, a propyl, a butyl, a pentyl, or a hexyl; alternatively at least one R may be ethyl, propyl, or 1 -methylethyl; alternatively at least one R may be ethyl.

[0040] It is believed that by using a multivinyl-functional monomer having the aforementioned molecular weight and vinyl content, the cluster crosslinks may be created in the hydrosilylation-cured polyorganosiloxane. It is believed that using a multivinyl-functional monomer that is an organosilane having a molecular weight less than 1 10 g/mol or an organosiloxane having a molecular weight less than 280 g/mol would lack sufficient number of vinyl groups for creating the grouped polyorganosiloxane chains of the cluster crosslinker and having a molecular weight greater than 2,000 g/mol would "explode" the cluster such that it no longer comprises a cluster crosslinker, but would undesirably have optical properties with more resin-like character (i.e., optical properties of resins).

[0041] Ingredient (C) is the SiH functional organosiloxane crosslinker. The crosslinker may have an average, per molecule, of at least two silicon bonded hydrogen atoms. Ingredient (C) may comprise a polyorganohydrogensiloxane. Ingredient (C) can be a single polyorganohydrogensiloxane or a combination comprising two or more (e.g., two, alternatively three) polyorganohydrogensiloxanes that differ in at least one of the following properties: structure, viscosity, average molecular weight, siloxane units, and sequence.

[0042] Ingredient (C) of NRHCP Composition may comprise a linear polyorganohydrogensiloxane of general formula (XVI): HR¹2SiO-(R¹2SiO)_c-SiR¹2H (XVI), where each R¹ is independently a hydrogen atom (H), or a monovalent organic group, which is a monovalent substituted or unsubstituted hydrocarbon group, with the proviso that on average at least two R¹ per molecule are hydrogen atoms, and subscript c is an integer with a value of 1 or more. Alternatively, at least three R¹ per molecule are hydrogen atoms and c may range from 0 to 200, alternatively from 1 to 200, alternatively from 1 to 100, alternatively from 1 to 60, alternatively from 1 to 20, alternatively 1 to 10. Ingredient (C) may comprise a hydrogen terminated polydiorganosiloxane. Alternatively, ingredient (C) may comprise a poly(dimethyl/methylhydrogen)siloxane copolymer.

[0043] Alternatively, ingredient (C) of NRHCP Composition may comprise a branched polyorganohydrogensiloxane of unit formula (XVII): (R²Si0₃ 2)d(R²2Si02/2)e(^R23Si0₁ 2)f(Si04 2)g(XO)_h (XVII), where X' is an alkoxy- functional group. Each R² is independently a hydrogen atom or a monovalent organic group, which is a monovalent substituted or unsubstituted hydrocarbon group, with the proviso that an average of at least two per molecule of R² are hydrogen atoms. In formula (XVII), the polyorganohydrogensiloxane contains an average of at least two silicon bonded hydrogen atoms per molecule, however, 0.1 mol% to 40 mol% of R² may be hydrogen atoms.

[0044] In formula (XVII), subscript d is a positive number, subscript e is 0 or a positive number, subscript f is 0 or a positive number, subscript g is 0 or a positive number, subscript h is 0 or a positive number, e/d has a value ranging from 0 to 10, f/e has a value ranging from 0 to 5, g/(d+e+f+g) has a value ranging from 0 to 0.3, and h/(d+e+f+g) has a value ranging from 0 to 0.4.

[0045] The amount of ingredient (C) is sufficient to provide the SiH/Vi ratio in the range described above.

[0046] Ingredient (D) is the hydrosilylation reaction catalyst. Ingredient (D) is added in an amount sufficient to promote curing of the composition. However, the amount of ingredient (D) may range from 0.01 to 1 ,000 ppm, alternatively 0.01 to 100 ppm, and alternatively 0.01 to 50 ppm, alternatively 0.1 to 18 ppm, alternatively 1 to 18 ppm, alternatively 0.3 to 7 ppm, alternatively 0.5 to 7 ppm, alternatively 1 to 7 ppm, of platinum group metal (e.g., Pt) based on the weight of the NRHCP Composition. The ingredient (D) the hydrosilylation reaction catalyst may be a single type of molecule or structure, alternatively (D) the hydrosilylation reaction catalyst may be a combination of any two or more (e.g., two) different said molecules that differ in at least one of the following properties: structure, metal, average molecular weight, method of preparation or activation, or support, if any.

[0047] Hydrosilylation catalysts are known in the art and are commercially available. These catalysts are suitable for use as ingredient (D) of the NRHCP Composition. Ingredient (D) may comprise a platinum group metal selected from the group consisting of platinum, rhodium, ruthenium, palladium, osmium or iridium metal or organometallic compound thereof, and a combination thereof. Ingredient (D) is exemplified by platinum black, platinum compounds such as chloroplatinic acid, chloroplatinic acid hexahydrate, a reaction product of chloroplatinic acid and a monohydric alcohol, platinum bis-(ethylacetoacetate), platinum bis- (acetylacetonate), platinum dichloride, and complexes of said platinum compounds with olefins or low molecular weight organopolysiloxanes or platinum compounds microencapsulated in a matrix or core-shell type structure. Complexes of platinum with low molecular weight organopolysiloxanes include 1 ,3-diethenyl-1 ,1 ,3,3-tetramethyldisiloxane complexes with platinum. These complexes may be microencapsulated in a resin matrix. Alternatively, the catalyst may comprise 1 ,3-diethenyl-1 ,1 ,3,3-tetramethyldisiloxane complex with platinum. Examples of suitable hydrosilylation catalysts for ingredient (D) are described in, for example, U.S. Patents 3,159,601 ; 3,220,972; 3,296,291 ; 3,419,593; 3,516,946; 3,814,730; 3,989,668; 4,784,879; 5,036,1 17; and 5,175,325 and EP 0 347 895 B. Microencapsulated hydrosilylation catalysts and methods of preparing them are exemplified in U.S. Patent No. 4,766,176; and U.S. Patent No. 5,017,654.

[0048] The NRHCP Composition may further consist of one or more non-resinous additional ingredients. The one or more additional non-resinous ingredients are optional. Suitable additional non-resinous ingredients include, but are not limited to non-resinous: (E) a second polyorganosiloxane polymer, (F) an adhesion promoter, (G) a hydrosilylation inhibitor, (H) a mold release agent, (I) an optically active agent, (J) a filler, (K) a heat stabilizer, (L) a flame retardant, (M) a reactive diluent, (N) a pigment, (O) an oxidation inhibitor, and (P) a combination of any two or more thereof. Optional ingredients (E) to (G) are described in detail below. Optional ingredients (H) to (O) are well known in the art and may be found, e.g., in US 2013/0248163 A1 to Bhagwagar D., et al.

[0049] The NRHCP Composition may further comprise the non-resinous ingredient (E) a second polyorganosiloxane polymer having vinyl groups and a M_w of from 1 ,000 to < 40,000 g/mol and containing vinyl groups only on terminal ends of the second polyorganosiloxane polymer or some on terminal ends and others pendant thereon, and having on average at least two vinyl groups per molecule and a pendant vinyl content, when present, of from 0.01 to 1 .0 wt%, alternatively from 0.01 to 0.5 wt%, alternatively from 0.01 to 0.2 wt%, alternatively from 0.05 to 1 .0 wt%, alternatively from 0.05 to 0.5 wt%, alternatively from 0.05 to 0.2 wt%, alternatively from 0.1 to 1 .0 wt%, alternatively from 0.1 to 0.5 wt%, alternatively from 0.1 to 0.2 wt%, all based on weight of ingredient (E). The DP of ingredient (E) is less than the DP of ingredient (A). The (E) second polyorganosiloxane polymer may consist of only linear molecules, which may be straight chain or branched chain. The second polyorganosiloxane polymer may consist of only straight chain linear molecules. The vinyl groups of (E) the second polyorganosiloxane polymer may be only on terminal ends of the second polyorganosiloxane polymer and the second polyorganosiloxane polymer may consist of only straight chain linear molecules. The second polyorganosiloxane polymer may have a M_w of from 1 ,000 to 40,000 g/mol, alternatively from 1 ,000 to 30,000 g/mol, alternatively from 1 ,000 to 25,000 g/mol, alternatively from 1 ,500 to 40,000 g/mol, alternatively from 1 ,500 to 30,000 g/mol, alternatively from 1 ,500 to 25,000 g/mol, alternatively from 2,000 to 40,000 g/mol, alternatively from 2,000 to 30,000 g/mol, alternatively from 2,000 to 25,000 g/mol. The second polyorganosiloxane polymer may be a vinyl-terminated polydimethylsiloxane lacking pendant vinyl groups, alternatively a vinyl- terminated polydimethylsiloxane also having pendant vinyl groups, alternatively a vinyl- terminated polydimethyl,methylphenylsiloxane lacking pendant vinyl groups, alternatively a vinyl-terminated polydimethyl,methylphenylsiloxane also having pendant vinyl groups, alternatively a vinyl-terminated polydiphenylsiloxane lacking pendant vinyl groups, alternatively a vinyl-terminated polydiphenylsiloxane also having pendant vinyl groups. The pendant vinyl content, when present, is described above. The DP of ingredient (E) is less than the DP of ingredient (A).

[0050] The NRHCP Composition may further comprise the non-resinous ingredient (F) an adhesion promoter for promoting adhesion to an organic polymer. Suitable adhesion promoters for ingredient (F) may comprise a transition metal chelate, a hydrocarbonoxysilane such as an alkoxysilane, a combination of an alkoxysilane and a hydroxy-functional polyorganosiloxane, an aminofunctional silane, or a combination thereof. Adhesion promoters are known in the art and may comprise silanes having the formula R3_tR4_uSi(OR5)4_ _{t + u}) where each R^ is independently a monovalent organic group having at least 3 carbon atoms; R⁴ contains at least one SiC bonded substituent having an adhesion-promoting group, such as amino, epoxy, mercapto or acrylate groups; subscript t has a value ranging from 0 to 2; subscript u is either 1 or 2; and the sum of (t + u) is not greater than 3. Alternatively, the adhesion promoter may comprise a partial condensate of the above silane. Alternatively, the adhesion promoter may comprise a combination of an alkoxysilane and a hydroxy-functional polyorganosiloxane. R^ is (C-| -Cg)alkyl and is exemplified by methyl, ethyl, propyl, and butyl.

[0051] Alternatively, the adhesion promoter may comprise an unsaturated or epoxy- functional compound. The adhesion promoter may comprise an unsaturated or epoxy- functional alkoxysilane. For example, the functional alkoxysilane can have the formula

R6_vSi(OR⁷)(4__v), where subscript v is 1 , 2, or 3, alternatively subscript v is 1 . Each R^ is independently a monovalent organic group with the proviso that at least one R^ is an unsaturated organic group or an epoxy-functional organic group. Epoxy-functional organic groups for R^ are exemplified by 3-glycidoxypropyl and (epoxycyclohexyl)ethyl. Unsaturated organic groups for R^ are exemplified by 3-methacryloyloxypropyl, 3-acryloyloxypropyl, and unsaturated monovalent hydrocarbon groups such as vinyl, allyl, hexenyl, undecylenyl. Each R⁷ is independently a saturated hydrocarbon group of 1 to 4 carbon atoms, alternatively 1 to

2 carbon atoms. R⁷ is (C-| -Cg)alkyl and is exemplified by methyl, ethyl, propyl, and butyl.

[0052] Examples of suitable epoxy-functional alkoxysilanes include 3- glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (epoxycyclohexyl)ethyldimethoxysilane, (epoxycyclohexyl)ethyldiethoxysilane and combinations thereof. Examples of suitable unsaturated alkoxysilanes include vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, hexenyltrimethoxysilane, undecylenyltrimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane, 3- methacryloyloxypropyl triethoxysilane, 3-acryloyloxypropyl trimethoxysilane, 3- acryloyloxypropyl triethoxysilane, and combinations thereof.

[0053] Alternatively, the adhesion promoter may comprise an epoxy-functional siloxane such as a reaction product of a hydroxy-terminated polyorganosiloxane with an epoxy- functional alkoxysilane, as described above, or a physical blend of the hydroxy-terminated polyorganosiloxane with the epoxy-functional alkoxysilane. The adhesion promoter may comprise a combination of an epoxy-functional alkoxysilane and an epoxy-functional siloxane. For example, the adhesion promoter is exemplified by a mixture of 3- glycidoxypropyltrimethoxysilane and a reaction product of hydroxy-terminated methylvinylsiloxane with 3-glycidoxypropyltrimethoxysilane, or a mixture of 3- glycidoxypropyltrimethoxysilane and a hydroxy-terminated methylvinylsiloxane, or a mixture of 3-glycidoxypropyltrimethoxysilane and a hydroxy-terminated methylvinyl/dimethylsiloxane copolymer.

[0054] Alternatively, the adhesion promoter may comprise an aminofunctional silane, such as an aminofunctional alkoxysilane exemplified by H₂N(CH₂)₂Si(OCH₃)3, H₂N(CH₂)₂Si(OCH₂CH₃)₃, H₂N(CH₂)₃Si(OCH₃)3, H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₅Si(OCH₃)₃,

CH₃NH(CH₂)₅Si(OCH₂CH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, CH3NH(CH₂)₂NH(CH₂)3SiCH3(OCH₂CH₃)2, C₄H₉NH(CH₂)₂NH(CH₂)3SiCH3(OCH₃)_2! C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)_2! and a combination thereof.

[0055] Alternatively, the adhesion promoter may comprise a transition metal chelate. Suitable transition metal chelates include titanates, zirconates such as zirconium acetyl aceton ate, aluminum chelates such as aluminum acetylacetonate, and combinations thereof.

[0056] The NRHCP Composition may further comprise a non-resinous ingredient (G) a hydrosilylation inhibitor for inhibiting ingredient (D) the hydrosilylation reaction catalyst. Ingredient (G), when used in NRHCP Composition, is a hydrosilylation reaction inhibitor. Suitable hydrosilylation reaction inhibitors are exemplified by acetylenic alcohols, cycloalkenylsiloxanes, ene-yne compounds, triazoles, phosphines; mercaptans; hydrazines; amines, and combinations thereof. Suitable acetylenic alcohols are exemplified by methyl butynol, ethynyl cyclohexanol, dimethyl hexynol, 3,5-dimethyl-1 -hexyn-3-ol, and a combination thereof; cycloalkenylsiloxanes such as methylvinylcyclosiloxanes exemplified by 1 ,3,5,7-tetramethyl-1 ,3,5,7-tetravinylcyclotetrasiloxane, 1 ,3,5,7-tetramethyl-1 ,3,5,7- tetrahexenylcyclotetrasiloxane, and a combination thereof; ene-yne compounds such as 3- methyl-3-penten-1 -yne, 3,5-dimethyl-3-hexen-1 -yne; triazoles such as benzotriazole; phosphines; mercaptans; hydrazines; amines such as tetramethyl ethylenediamine, dialkyl fumarates, dialkenyl fumarates, dialkoxyalkyl fumarates, maleates such as diallyl maleate, and a combination thereof. Suitable inhibitors are disclosed by, for example, U.S. Patents 3,445,420; 3,989,667; 4,584,361 ; and 5,036,1 17. Alternatively, ingredient (G) may comprise an organic acetylenic alcohol, a silylated acetylenic alcohol, or a combination thereof. Examples of organic acetylenic alcohol inhibitors are disclosed, for example, in EP 0 764 703 A2 and U.S. Patent 5,449,802 and include 1 -butyn-3-ol, 1 -propyn-3-ol, 2-methyl-3- butyn-2-ol, 3-methyl-1 -butyn-3-ol, 3-methyl-1 -pentyn-3-ol, 3-phenyl-1 -butyn-3-ol, 4-ethyl-1 - octyn-3-ol, 3,5-dimethyl-1 -hexyn-3-ol, and 1 -ethynyl-1 -cyclohexanol. Alternatively, ingredient (G) in the NRHCP Composition may be a silylated acetylenic inhibitor. Without wishing to be bound by theory, it is thought that adding a silylated acetylenic inhibitor may reduce yellowing of the cured product prepared from the NRHCP Composition as compared to a cured product prepared from a hydrosilylation curable composition that does not contain a hydrosilylation reaction inhibitor or that contains an organic acetylenic alcohol inhibitor. The NRHCP Composition may be free of organic acetylenic alcohol inhibitors. "Free of organic acetylenic alcohol inhibitors" means that if any organic acetylenic alcohol is present in the NRHCP Composition, the amount present is insufficient to reduce optical transparency of the cured product to < 95 % at a thickness of 2.0 mm or less at 400 nm wavelength after heating at 200 degrees Celsius (° C.) for 14 days.

[0057] Ingredient (G), when used in NRHCP Composition, may be added in an amount ranging from 0.001 to 1 parts by weight based on the total weight of the NRHCP Composition, alternatively 0.01 to 0.5 parts by weight. Suitable silylated acetylenic inhibitors for ingredient (G) may have general formula (V):

general formula (VI):

, or a combination thereof;

where each R⁸ is independently a hydrogen atom or a monovalent organic group, and subscript n is 0, 1 , 2, or 3, subscript q is 0 to 10, and subscript r is 4 to 12. Alternatively n is 1 or 3. Alternatively, in general formula (V), n is 3. Alternatively, in general formula (VI), n is 1 . Alternatively q is 0. Alternatively, r is 5, 6, or 7, and alternatively r is 6. Examples of monovalent organic groups for R⁸ include an aliphatically unsaturated organic group, an aromatic group, or a monovalent organic group, which is a monovalent substituted or unsubstituted hydrocarbon group free of aromatics and free aliphatic unsaturation, as described above. R⁹ is a covalent bond or a divalent hydrocarbon group.

[0058] Silylated acetylenic inhibitors of ingredient (G), when used in NRHCP Composition, are exemplified by (3-methyl-1 -butyn-3-oxy)trimethylsilane, ((1 ,1 -dimethyl-2- propynyl)oxy)trimethylsilane, bis(3-methyl-1 -butyn-3-oxy)dimethylsilane, bis(3-methyl-1 - butyn-3-oxy)silanemethylvinylsilane, bis((1 ,1 -dimethyl-2-propynyl)oxy)dimethylsilane, methyl(tris(1 ,1 -dimethyl-2-propynyloxy))silane, methyl(tris(3-methyl-1 -butyn-3-oxy))silane, (3-methyl-1 -butyn-3-oxy)dimethylphenylsilane, (3-methyl-1 -butyn-3- oxy)dimethylhexenylsilane, (3-methyl-1 -butyn-3-oxy)triethylsilane, bis(3-methyl-1 -butyn-3- oxy)methyltrifluoropropylsilane, (3,5-dimethyl-1 -hexyn-3-oxy)trimethylsilane, (3-phenyl-1 - butyn-3-oxy)diphenylmethylsilane, (3-phenyl-1 -butyn-3-oxy)dimethylphenylsilane, (3-phenyl- 1 -butyn-3-oxy)dimethylvinylsilane, (3-phenyl-1 -butyn-3-oxy)dimethylhexenylsilane,

(cyclohexyl-1 -ethyn-1 -oxy)dimethylhexenylsilane, (cyclohexyl-1 -ethyn-1 - oxy)dimethylvinylsilane, (cyclohexyl-1 -ethyn-1 -oxy)diphenylmethylsilane, (cyclohexyl-1 - ethyn-1 -oxy)trimethylsilane, and combinations thereof. Alternatively, ingredient (G) is exemplified by methyl(tris(1 ,1 -dimethyl-2-propynyloxy))silane, ((1 ,1 -dimethyl-2- propynyl)oxy)trimethylsilane, or a combination thereof.

[0059] The silylated acetylenic inhibitor of ingredient (G), when used in NRHCP Composition, may be prepared by methods known in the art for silylating an alcohol such as reacting a chlorosilane of formula R⁶ _nSiCI₄._n with an acetylenic alcohol of formula

the presence of an acid receptor. In these formulae, n, q, r, and R are as described above and R⁹ is a covalent bond or a divalent hydrocarbon group. Examples of silylated acetylenic inhibitors and methods for their preparation are disclosed, for example, in EP 0 764 703 A2 and U.S. Patent 5,449,802.

[0060] The NRHCP Composition may lack an ingredient that is a solid filler, may lack intentionally added cyclosiloxane, or may lack both a solid filler and intentionally added cyclosiloxane. (It is theoretically possible for cyclosiloxane to be present as an impurity at an insignificant concentration in the NRHCP Composition. The hydrosilylation-cured polyorganosiloxane prepared from NRHCP Composition may lack a liquid phase, may lack any crosslink other than a cluster crosslink, or may lack both the liquid phase and any crosslink other than a cluster crosslink. The hydrosilylation-cured polyorganosiloxane prepared from NRHCP Composition may contain end-to-end coupling, i.e., chain extension.

[0061] The NRHCP Composition may comprise the most preferred embodiment of each one of ingredients (A) to (D), alternatively ingredients (A) to (E), alternatively ingredients (A) to (F), alternatively ingredients (A) to (E) and (G), alternatively ingredients (A) to (G).

[0062] Any embodiment of the NRHCP Composition may be prepared by any convenient means, such as mixing all ingredients at ambient or elevated temperature. The NRHCP Composition may be prepared as a one-part composition or a multiple part composition. A one-part NRHCP Composition can be prepared by mixing ingredients (A), (B), (C), and (D) and any additional ingredients such as any one or more of optional ingredients (E) to (G), if present. If a one part NRHCP Composition will be prepared, pot life of the NRHCP Composition may be extended by adding ingredient (G) described above. If the NRHCP Composition will be used in a molding process (or overmolding process), such as that described herein, then a mold release agent may be added. In a multiple part NRHCP Composition, such as a two part NRHCP Composition, ingredients (C) and (D) are stored in separate parts such as a base part and a curing agent part. For example, a base part may be prepared by mixing ingredients comprising: 60% to 75% ingredient (A), 25% to 40% ingredient (B), and 6 ppm ingredient (D). The base part may optionally further comprise 0.2 to 5 parts ingredient (E), (F), and/or (G), when used in NRHCP Composition. A curing agent part may be prepared by mixing ingredients comprising: 50% to 70% ingredient (A), 20% to 37% ingredient (B), 7% to 16% by weight ingredient (C), and, if present, 0.001 to 1 % ingredient (E). The curing agent part may optionally further comprise 0.2 to 5 parts ingredient (F), when used in NRHCP Composition. The base part and the curing agent part may be stored in separate containers until just prior to use. Just prior to use, the base and curing agent parts are mixed together in a ratio of, for example, 1 to 10 parts base part per 1 part curing agent part.

[0063] Generally, the NRHCP Composition may be hydrosilylation cured at ambient temperature or with heating the NRHCP Composition at elevated temperature, for an ad rem time period. Heating may accelerate the curing. The exact time and temperature for heating will vary depending on various factors including the amount of catalyst and the type and amount of inhibitor (ingredient (G)) present (if any), however hydrosilylation curing may be performed by heating the NRHCP Composition at the elevated cure temperature ranging from 50 ° C. to 200 ° C., e.g., from 80° C. to 180° C., alternatively from 80° C. to 150° C. (e.g., 120° or 150° C, and for the amount of cure time ranging from 1 second to 100 minutes, e.g., from 1 to 80 minutes, from 30 seconds to 20 minutes (e.g., 5 minutes or 75 minutes). All other things being equal, the higher the cure temperature the lower the cure time for achieving a given level of curing, and the lower the cure temperature, the higher the cure time for achieving a given level of curing.

[0064] The cured polyorganosiloxane may be a hydrosilylation-cured polyorganosiloxane prepared by curing the NRHCP Composition of any one of the preceding embodiments. The hydrosilylation-cured polyorganosiloxane may have a light-guide effective crosslink density of the aforementioned cluster crosslinks and lack optical properties with resin-like character (i.e., optical properties of polyorganosiloxane resins) as described above. For example, the hydrosilylation-cured polyorganosiloxane may have mechanical strength as represented by elongation-at-break and/or tensile strength and high light transmittance as represented by reflectivity-corrected light transmittance or haze value.

[0065] For example, the hydrosilylation-cured polyorganosiloxane may have a high light transmission as indicated by a reflectivity-corrected light transmittance of visible light of > 99.50%, alternatively > 99.60%, alternatively > 99.70%, all when tested using a 3.85 millimeters (mm) sample with light at from 400 to 700 nm, alternatively 400 nm, alternatively 700 nm. Alternatively, the hydrosilylation-cured polyorganosiloxane may have an elongation- at-break, at 25° C, of > 10%, alternatively > 15%, alternatively >25%, alternatively > 40%, alternatively > 50%, alternatively > 60%, alternatively > 100%, alternatively > 13% and < 65%, alternatively > 40% and < 75%, and a high light transmission as indicated by a reflectivity-corrected light transmittance of > 99.00%, alternatively > 99.10%, alternatively > 99.20%, all when tested using a 3.85 mm sample with light from 375 to 725 nm, alternatively from 400 to 700 nm. Alternatively, hydrosilylation-cured polyorganosiloxane may have a reflectivity-corrected light transmittance of visible light of > 99.50%, alternatively > 99.60%, alternatively > 99.70%, all when tested using a 3.85 millimeters (mm) sample with light at from 400 to 700 nm.

[0066] The hydrosilylation-cured polyorganosiloxane may have a high amount of light transmission as indicated by the non-reflectivity corrected transmittance of visible light of > 90.0%, alternatively > 90.5%, alternatively > 91 .0%, all when tested using a 25.0 mm thick sample with light at a wavelength from 400 to 700 nm, alternatively at a wavelength of 400 nm, alternatively at 700 nm. Alternatively, the hydrosilylation-cured polyorganosiloxane may have a high amount of reflectivity corrected light transmission as indicated by transmittance of visible light of > 99.00%, alternatively > 99.10%, alternatively > 99.20%, all when tested using a 25.0 mm thick sample with light at a wavelength from 375 to 725 nm, alternatively at a wavelength from 400 to 700 nm.

[0067] In addition to the aforementioned efficiency of transmission of light comprising visible light, the hydrosilylation-cured polyorganosiloxane may have an elongation-at-break, at 25° C, of > 10%, alternatively > 20%, alternatively > 30%, alternatively > 50%, alternatively > 42% and < 75%. The elongation-at-break may be at least 150%, alternatively from 100% to 400%, alternatively from 100% to 350%, alternatively from 150% to 400%, all as measured by ASTM D412. [0068] Alternatively or additionally, the hydrosilylation-cured polyorganosiloxane may have a high light transmission as indicated by a haze value from 0 to 3.0%, alternatively from > 0 to < 3.0%, alternatively from 0.01 to 2.5%, alternatively from 0.01 to < 2.5%, alternatively from 0.01 to 2.0%, alternatively from 0.01 to < 2.0%, all when tested using a 3.85 mm sample with light at 400 nm. Additionally, the hydrosilylation-cured polyorganosiloxane may also have an elongation-at-break of greater than 10% as described herein.

[0069] Alternatively to the elongation-at-break or additionally thereto, and In addition to the aforementioned efficiency of transmission of light comprising visible light, the hydrosilylation- cured polyorganosiloxane may have a maximum tensile strength of at least (i.e., greater than or equal to) 0.2 megapascals (MPa), alternatively at least 0.3 MPa. Alternatively or additionally, the hydrosilylation-cured polyorganosiloxane has a maximum tensile strength of at least 0.2 MPa and a high light transmission as indicated by a haze value from >0 to less than 3.0 percent when tested using a 3.85 mm sample with light at 400 nm. Alternatively, the maximum tensile strength may range from 0.2 MPa to 10 MPa, alternatively from 0.2 to 0.4 MPa. Alternatively, the elongation-at-break is greater than 10 percent at 25° C. and the maximum tensile strength is at least 0.2 MPa. Maximum tensile strength is as measured by ASTM D412.

[0070] The hydrosilylation-cured polyorganosiloxane may also have no or low dust pickup.

[0071] The hydrosilylation-cured polyorganosiloxane has functional properties that make it suitable for use as a light guide. The light guide is a solid light guide.

[0072] The light guide may be a free-standing light guide comprising the hydrosilylation- cured polyorganosiloxane of any one of the preceding embodiments. The free-standing light guide may lack a support or may be supported only in one dimension. The free-standing light guide may be configured to contain morphological features for extracting light from the light guide when light is present therein. The light guide may have a light-guide effective crosslink density of the aforementioned cluster crosslinks and lack T and Q units. For example, the light guide may have any one of the combinations of mechanical strength as represented by elongation-at-break and/or tensile strength and high light transmittance as represented by reflectivity-corrected light transmittance or haze value characteristics mentioned earlier for the hydrosilylation-cured polyorganosiloxane.

[0073] An embodiment of the free-standing light guide is shown in Fig. 1 . In Fig. 1 , the embodiment free-standing light guide 10 has top surface 18 and bottom surface 19 and defines a linear optical pathway 1 therethrough from proximal end 1 1 to distal end 12 of light guide 10 and a non-linear optical pathway 2 therethrough from proximal end 1 1 to distal end 13 that is the bottom surface 19 of light guide 10. The optical pathway may be linear or nonlinear. Non-linear optical pathways are contemplated wherein the light guide contains features that may reflect, refract or bend light, including aspects where light extraction from the light guide is perpendicular to the plane of the light guide.

[0074] Alternatively, the light guide may be a composite light guide comprising the hydrosilylation-cured polyorganosiloxane, which may include ingredient (F) the adhesion promoter, wherein the hydrosilylation-cured polyorganosiloxane is disposed on a support. The composite light guide may comprise a film, plate or slab (thicker than a film) of the hydrosilylation-cured polyorganosiloxane disposed on the support. The support may be a film or may be any other shape. The support may be a optically clear; alternatively the support may be a reflector for reflecting light such as visible light. The optically clear support may be made of any optically clear material, including a silicate glass or an optically clear organic polymer. The silicate glass may comprise a window of a building, skylight, or windshield of a vehicle. The organic polymer may be a fluoropolymer, a fluoro- chloropolymer, a polyester copolymer (e.g., poly(ethylene terephthalate), a polycarbonate (PC) or optically clear poly(methyl methacrylate) (PMMA) such as a base component of a luminaire. For example, the organic polymer of the support may be a PC or a PMMA, alternatively a PC, alternatively a PMMA. The optically clear support may be configured to contain morphological features or reflective features (e.g., a white film support) for extracting light from the composite light guide when light is present therein. The composite light guide may be supported only in one dimension, alternatively in two dimensions. The light guide film, plate or slab or the support of the composite light guide may be treated before forming the light guide film, plate or slab on the support. The treatment may comprise contacting the light guide film (or plate or slab), support, or both with a primer or a plasma.

[0075] The NRHCP Composition of any one of the preceding embodiments may be cured in a mold so as to make a shaped form of the hydrosilylation-cured polyorganosiloxane. The shaped form may be configured as the light guide. The shaped hydrosilylation-cured polyorganosiloxane may be mechanically joined to another such shaped polyorganosiloxane to form the mechanical joint and effective optical interface of the modular devices. The shaped hydrosilylation-cured polyorganosiloxane may be prepared by a molding method such as injection molding or compression molding. When prepared in as a film, plate or slab (all restricted in one dimension, the film restricted more than the plate or slab), the shaped hydrosilylation-cured polyorganosiloxane may be prepared by a coating method such as a coating method employing a doctor blade. The viscosity of the NRHCP Composition is suitable for use in high-speed coating methods. The shaped hydrosilylation-cured polyorganosiloxane may be a light guide.

[0076] The light guides allow transmission of light therethrough, e.g., visible light transmission. The light being transmitted may include, but is not limited to, visible light such as light from 375 to 725 nm, alternatively from 400 to 700 nm, alternatively 400 nm, alternatively 700 nm. The efficiency of transmission of visible light advantageously is increased relative to a comparative resinous composition as described earlier. Alternatively or additionally, transmission efficiency for light other than visible light may be allowed and increased relative to the comparative resinous composition. The light guide may be configured to have a shape having an aspect ratio greater than 2 so as to primarily conduct light in one dimension. For example, the light guide may function as a core layer in an optical wave guide, which comprises lower and upper cladding layers and the light guide core layer, which has a refractive index that is different than the cladding layers. The lower and upper cladding layers independently may be a different embodiment of the hydrosilylation-cured polyorganosiloxane having a different refractive index than the embodiment of the hydrosilylation-cured polyorganosiloxane from which the core layer is made; alternatively the lower and upper cladding layers may be a resinous polyorganosiloxane. The cross-sectional profile of the one-dimension light guide may be any shape such as random, elliptical, rhombohedral, square, rectangular, ovoid, or circular. Alternatively, the light guide may be configured to have a shape that is restricted in one dimension so as to primarily conduct light in two dimensions. For example, the light guide may be a film of the hydrosilylation-cured polyorganosiloxane. The film may have a thickness of from > 0 to 10 mm, alternatively from > 0 to 7 mm, alternatively from > 0 to 4 mm, alternatively at most 2 mm, alternatively at most 1 mm, alternatively at most 0.1 mm, alternatively at least 0.001 mm, alternatively at least 0.01 mm, alternatively at least 0.5 mm. Alternatively, the light guide may be configured to have a 3-dimensional shape so as to conduct light in three dimensions. For example, the light guide may be a bulk shape of the hydrosilylation-cured polyorganosiloxane, wherein the bulk shape may be, e.g., a sphere, hemisphere, ovoid, pyramidal, or box shape.

[0077] The light guides may be used to make an optoelectronic device comprising the light guide and at least one light element. The optoelectronic device may comprise at least one light element and the free-standing light guide of any one of the preceding embodiments, wherein the free-standing light guide is configured to transmit light when light is emitted from the light element. Alternatively, the optoelectronic device may comprise at least one light element and the composite light guide of any one of the preceding embodiments, wherein the composite light guide is configured to transmit light when light is emitted from the at least one light element. The optoelectronic device may further comprise additional elements such as an optical encapsulant for encapsulating the at least one light element, a lens for controlling direction of light being emitted from the at least one light element, at least one electrical connector for conducting electricity to the at least one light element, or any combination of two or more or all of the preceding additional elements. The optical encapsulant and lens independently may be a polyorganosiloxane or an organic polymer. The electrical connector(s) independently may be a wire, tabbing, or ribbon and may be made of a highly conductive metal such as Cu, Au, Ag, and alloys thereof.

[0078] The optoelectronic devices may be used to make luminaires, which are devices having at least one light element that is a light-generating element. The luminaire may comprise an optoelectronic device of any one of the preceding embodiments and a power supply for powering the at least one light element. The luminaire may further comprise additional elements such as the optical encapsulant for encapsulating the at least one light element, a lens for controlling direction of light being emitted from the at least one light element, at least one electrical connector for conducting electricity to the at least one light element, or any combination of two or more or all of the preceding additional elements. The power supply may be in operative electrical communication with the at least one light element via the electrical connector(s).

[0079] Each light element of an optoelectronic device or luminaire of any one of the preceding embodiments may be a light emitting device such as a light-emitting diode (LED), a liquid crystal display (LCD), or any other light source. The light source may emit light comprising visible light.

[0080] Due to its high visible light transmission character, especially from 375 to 725 nm, alternatively from 400 to 700 nm, alternatively 400 nm, alternatively 700 nm, the light guide made of the hydrosilylation-cured polyorganosiloxane, and thus the optoelectronic and luminaire devices containing the light guide, may be used in the method of transmitting light comprising visible light and in the method of illuminating a surface with light comprising visible light.

[0081] Advantageously, the light guide may define an optical pathway therethrough by which the transmitted light travels during these methods. As described earlier, the optical pathway may be linear or non-linear. The optical pathway has a proximal end where light is introduced into the light guide and a distal end where transmitted light is to exit the light guide, wherein the proximal and distal ends of the optical pathway are in optical communication with each other via the optical pathway. The proximal and distal ends of the optical pathway independently may be exterior to the light guide or interior to the light guide. For example, the at least one light element may be a light-generating element, and the light- generating element may be disposed within the light guide such that the proximal end of the optical pathway is interior to the light guide. Alternatively, the light-generating element may be disposed exterior to the light guide such that the proximal end of the light guide is an exterior surface of the light guide. Similarly, the at least one light element may be a light- receiving element, and the light-receiving element may be disposed within the light guide such that the distal end of the optical pathway is interior to the light guide. Alternatively, a light-receiving element may be disposed exterior to the light guide such that the distal end of the light guide is an exterior surface of the light guide. The optical pathway may be a short optical pathway of at most 100 mm, alternatively at most 50 mm, alternatively at most 10 mm, alternatively at most 4 mm. The optical pathway may be a medium optical pathway of >100 mm to < 5 centimeters (cm), alternatively 500 mm to < 5 cm, alternatively 1 to 5 cm. The optical pathway may be a long optical pathway of at least 5 cm, alternatively at least 10 cm, alternatively at most 10 meters (m), alternatively at most 5 m, alternatively at most 2 m, alternatively at most 1 m. The optical pathway may be linear, alternatively non-linear. Nonlinear optical pathways may be defined by configuring the light guides with structural morphology (e.g., angular features) for redirecting the direction of travel of the light. Non- linear optical pathways are created by morphological features that are designed into the light guides for extracting light from the light guides in a desired direction. Non-linear optical pathways exclude light scattering, which is an uncontrolled or random phenomenon.

[0082] At any given mechanical strength and length of the optical pathway, the percent transmission of visible light along optical pathway in the methods may be greater than the percent transmission of visible light along an equal length optical pathway in a resinous polyorganosiloxane having the same mechanical strength. Thus, the methods are useful with the light guides having optical pathways of 3.85 mm or greater, alternatively 1 mm or greater, alternatively 1 cm or greater, alternatively at least 5 cm, alternatively at least 10 cm, alternatively at least 1 m, such as up to 10 m.

[0083] The method of transmitting light comprising visible light to a light-receiving element via any one of the light guides may comprise a method of transmitting light comprising visible light to a light-receiving element via any one of the light guides made of the hydrosilylation- cured polyorganosiloxane and defining an optical pathway therethrough, wherein the optical pathway has a proximal end where light is introduced into the light guide and a distal end where transmitted light is to exit the light guide, wherein the proximal and distal ends of the optical pathway are in optical communication with each other via the optical pathway and wherein the distal end of the optical pathway of the light guide is disposed opposite the light- receiving element such that the light guide is configured for directing transmitted light exiting the light guide to the light-receiving element, the method comprising: Introducing light comprising visible light into the light guide at the proximal end of the optical pathway thereof; allowing the introduced light to transmit along the optical pathway through the light guide to give a transmitted light comprising visible light at the distal end of the optical pathway; and allowing the transmitted light to exit the light guide at the distal end of the optical pathway and be received by the light-receiving element. The light-receiving element may be a surface of an object and the method further comprises illuminating the surface. The object being illuminated may be any natural object or man-made object. The natural object may be a tree, lawn, garden, waterfall, or rock. The man-made object may be a wall (interior or exterior) of a building or room contained therein, a roof of a building or ceiling of a room, floor of a room, shelf or display in a store, merchandise, or work of art. Alternatively, the light-receiving element may be a light reflector, light diffuser, light attenuator, or a converter device for converting light comprising visible light into an electrical signal readable by an electronic device. The method may further comprise the electronic device disposed in electronic communication with the converter device and reading the electrical signal. The electronic device may be an integrated circuit or memory storage medium. The light comprising visible light being introduced into the light guide in the method may be from a natural or man-made light source. The method may further comprise introducing light comprising visible light from the light source into the light guide. The man-made light source may be a light emitting device such as those devices described earlier.

[0084] In addition to its use as a light guide in light guide applications the hydrosilylation- cured polyorganosiloxane is applicable for both passive-system elements and active-system elements for other applications. The following are examples of such other elements and applications: optical waveguides, optical adhesives, optical switches, optical attenuators, and optical amplifiers or similar active light-transmitting elements. Additional examples of suitable devices and applications in which the hydrosilylation-cured polyorganosiloxane may be utilized include volumetric phase gratings, Bragg gratings, Mach Zhender interferometers, lenses, amplifiers, cavities for lasers, acusto-optic devices, modulators, and dielectric mirrors. [0085] The NRHCP Composition has been described herein with a multivinyl-functional silicon monomer for ingredient (B) and SiH-functional organosiloxane crosslinker for ingredient (C). The invention also contemplates an alternative NRHCP Composition comprising the aforementioned ingredients (A) and (D), a multi-SiH-functional silicon monomer for ingredient (B), and a vinyl-functional crosslinker for ingredient (C). The multi- SiH-functional silicon monomer is the same as the multivinyl-functional silicon monomer except vinyl groups in the latter monomer have been formally replaced by H atoms in the former monomer. The vinyl-functional crosslinker is the same as the SiH-functional organosiloxane crosslinker except the SiH hydrogen atoms in the latter crosslinker have been formally replaced by vinyl groups in the former crosslinker.

[0086] In some embodiments the invention comprises any one of the following numbered aspects:

[0087] 1 . A non-resinous hydrosilylation-curable polyorganosiloxane composition consisting essentially of non-resinous ingredients that comprise non-resinous ingredients (A), (B), (C), and (D): a first polyorganosiloxane polymer having a weight average molecular weight of from 1 ,000 to 120,000 grams per mole and containing vinyl groups only on terminal ends of the first polyorganosiloxane polymer, only on pendant positions of the first

polyorganosiloxane polymer, or some on terminal ends and others pendant thereon, and having on average at least two vinyl groups per molecule and a pendant vinyl content, when present, of from 0.01 to 5 weight percent based on weight of ingredient (A); a multivinyl- functional silicon monomer containing 3 or more vinyl groups up to per vinyl substitution and being an organosiloxane having a molecular weight of from 280 to 2,000 grams per mole or being an organosilane having a molecular weight of from 124 to 2,000 g/mol; a SiH functional organosiloxane crosslinker having on average at least two SiH functional groups per molecule; and a hydrosilylation reaction catalyst; wherein the total SiH-to-vinyl molar ratio of the non-resinous hydrosilylation-curable polyorganosiloxane composition is from 0.1 to 10.

[0088] 2. The non-resinous hydrosilylation-curable polyorganosiloxane composition of aspect 1 wherein the vinyl groups of (A) the first polyorganosiloxane polymer are only on terminal ends of the first polyorganosiloxane polymer; or wherein the first

polyorganosiloxane polymer consists of only linear molecules, which may be straight chain or branched chain; or wherein the first polyorganosiloxane polymer consists of only straight chain linear molecules; or wherein the vinyl groups of (A) the first polyorganosiloxane polymer are only on terminal ends of the first polyorganosiloxane polymer and the first polyorganosiloxane polymer consists of only straight chain linear molecules.

[0089] 3. The non-resinous hydrosilylation-curable polyorganosiloxane composition of aspect 1 or 2 wherein (B) the multivinyl-functional monomer is an organosiloxane of formula (I): (H₂C=CHR₂SiO)4Si, wherein each R independently is H, (C-| -C₆)alkyl, H₂C=CH-, or phenyl; or an organosiloxane of formula (II): (H2C=CHR₂SiO)3Si-Si(OSiR2CH=CH2)3, wherein each R independently is H, (C-| -Cg)alkyl, H2C=CH-, or phenyl; or an

organosiloxane of formula (III): (H2C=CHR2SiO)3Si-SiR2-Si(OSi R2CH=C H2)3, wherein each R independently is H, (C-| -Cg)alkyl, H2C=CH-, or phenyl.

[0090] 4. The non-resinous hydrosilylation-curable polyorganosiloxane composition of aspect 1 or 2 wherein (B) the multivinyl-functional monomer is an organosilane of formula (IV): (H2C=CHR₂Si)4Si, wherein each R independently is H, (C-| -C6)alkyl, H₂C=CH-, or phenyl; or an organosilane of formula (V): (H2C=CHR2Si)3Si-Si(SiR2CH=CH2)3, wherein each R independently is H, (C-| -Ce)alkyl, H2C=CH-, or phenyl; or an organosilane of formula (VI): (H₂C=CHR₂Si)3Si-SiR2-Si(SiR2CH=C H₂)3, wherein each R independently is H,

(C-| -Ce)alkyl, H2C=CH-, or phenyl; or an organosilane of formula (VII): (H2C=CHR2)4Si, wherein each R independently is H, (C-| -Ce)alkyl, H2C=CH-, or phenyl; or an organosilane of formula (VIII): (H2C=CHR₂Si)3SiR, wherein each R independently is H, (C-| -CeJalkyl,

H₂C=CH-, or phenyl.

[0091] 5. The non-resinous hydrosilylation-curable polyorganosiloxane composition of aspect 3 or 4 wherein each R is methyl.

[0092] 6. The non-resinous hydrosilylation-curable polyorganosiloxane composition of any one of the preceding aspects further comprising a non-resinous ingredient (E) a second polyorganosiloxane polymer having vinyl groups and a weight average molecular weight of from 1 ,000 to < 40,000 grams per mole and containing vinyl groups only on terminal ends of the second polyorganosiloxane polymer or some on terminal ends and others pendant thereon, and having on average at least two vinyl groups per molecule and a pendant vinyl content, when present, of from 0.01 to 1 .0 weight percent based on weight of ingredient (E), wherein the Degree of Polymerization (DP) of ingredient (E) is less than the DP of ingredient (A). [0093] 7. The non-resinous hydrosilylation-curable polyorganosiloxane composition of any one of the preceding aspects further comprising a non-resinous ingredient (F) an adhesion promoter for promoting adhesion to an organic polymer.

[0094] 8. The non-resinous hydrosilylation-curable polyorganosiloxane composition of any one of the preceding aspects further comprising a non-resinous ingredient (G) a

hydrosilylation inhibitor for inhibiting ingredient (D) the hydrosilylation reaction catalyst.

[0095] 9. A hydrosilylation-cured polyorganosiloxane prepared by curing the non-resinous hydrosilylation-curable polyorganosiloxane composition of any one of the preceding aspects.

[0096] 10. The hydrosilylation-cured polyorganosiloxane of aspect 9 having a reflectivity- corrected light transmittance of greater than 99.50 percent when tested using a 3.85 millimeters sample with light at 400 nanometers or from 400 to 700 nanometers.

[0097] 1 1 . The hydrosilylation-cured polyorganosiloxane of aspect 9 or 10 having a haze value from >0 to less than 3.0 percent when tested using a 3.85 millimeters sample with light at 400 nanometers.

[0098] 12. The hydrosilylation-cured polyorganosiloxane of aspect 9, 10 or 1 1 further having an elongation-at-break greater than 100 percent, a tensile strength greater than 2

megapascals, or both an elongation-at-break greater than 100 percent and a tensile strength greater than 2 megapascals.

[0099] 13. A free-standing light guide comprising the hydrosilylation-cured

polyorganosiloxane of any one of aspects 9 to 12.

[00100] 14. An optoelectronic device comprising at least one light element and the free-standing light guide of aspect 13 wherein the free-standing light guide is configured to transmit light when light is emitted from the light element.

[00101] 15. A luminaire device comprising the optoelectronic device of aspect 14 and a power supply that is configured for powering the at least one light element.

[00102] 16. A composite light guide comprising the hydrosilylation-cured

polyorganosiloxane of any one of aspects 9 to 12 disposed on a support.

[00103] 17. The composite light guide of aspect 16 comprising a film of the

hydrosilylation-cured polyorganosiloxane disposed on the support.

[00104] 18. The composite light guide of aspect 16 or 17, wherein the support is a polycarbonate or a poly(methyl methacrylate). [00105] 19. The composite light guide of any one of aspects 16 to 18, wherein the support is configured to contain morphological features for extracting light from the composite light guide when light is present therein.

[00106] 20. An optoelectronic device comprising at least one light element and the composite light guide of any one of aspects 16 to 19, wherein the composite light guide is configured to transmit light when light is emitted from the light element.

[00107] 21 . A luminaire device comprising the optoelectronic device of aspect 20 and a power supply that is configured for powering the at least one light element.

[00108] 22. A hydrosilylation-cured polyorganosiloxane having an elongation-at-break of greater than 100% and having a reflectivity-corrected light transmittance of greater than 99.50 percent when tested using a 3.85 millimeters sample with light at 400 nanometers or at from 400 to 700 nanometers.

[00109] 23. A hydrosilylation-cured polyorganosiloxane having an elongation-at-break of greater than 100 % and having a haze value from >0 to less than 3.0 percent when tested using a 3.85 millimeters sample with light at 400 nanometers.

[00110] 24. A method of transmitting light comprising visible light to a light-receiving element via a light guide made of the hydrosilylation-cured polyorganosiloxane of any one of aspects 9 to 12 and defining an optical pathway therethrough, wherein the optical pathway has a proximal end where light is introduced into the light guide and a distal end where transmitted light is to exit the light guide, wherein the proximal and distal ends of the optical pathway are in optical communication with each other via the optical pathway and wherein the distal end of the optical pathway of the light guide is disposed opposite the light-receiving element such that the light guide is configured for directing transmitted light exiting the light guide to the light-receiving element, the method comprising: Introducing light comprising visible light into the light guide at the proximal end of the optical pathway thereof; allowing the introduced light to transmit along the optical pathway through the light guide to give a transmitted light comprising visible light at the distal end of the optical pathway; and allowing the transmitted light to exit the light guide at the distal end of the optical pathway and be received by the light-receiving element.

[00111] 25. The method of aspect 24 wherein the light-receiving element is a surface of an object and the method further comprises illuminating the surface.

[00112] 26. The method of aspect 24 wherein the light-receiving element is a light reflector, light diffuser, light attenuator, or a converter device for converting light comprising visible light into an electrical signal readable by an electronic device. [00113] Determining numerical property values: for purposes of the present invention and unless indicated otherwise, the numerical property values used herein may be determined by the following procedures.

[00114] Determining dynamic viscosity: for purposes of the present invention examples and unless indicated otherwise, use dynamic viscosity that is measured at 25° C. using a rotational viscometer such as a Brookfield Synchro-lectric viscometer or a Wells- Brookfield Cone/Plate viscometer. The results are generally reported in centipoise. This method is based on according to ASTM D1084-08 (Standard Test Methods for Viscosity of Adhesives) Method B for cup/spindle and ASTM D4287-00(2010) (Standard Test Method for High-Shear Viscosity Using a Cone/Plate Viscometer) for cone/plate.

[00115] Determining kinematic viscosity: use test method ASTM-D445-1 1 a (Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of

Dynamic Viscosity)) at 25° C. expressed in cSt or mm²/s units.

[00116] Determining M_w and M_n: use Gel Permeation Chromatograph (GPC) with a Waters model no. 2695 Separations Module, a Waters 2410 differential refractometer, and polystyrene as the standards.

[00117] Tensile strength and elongation-at-break, examples of mechanical strength, are measured according to ASTM D412. A dumbbell sample (cut by the die of D1708, ½ scale, Fremont) of material, in the thickness of 2.0±0.5 mm, was tested on a texture analyzer (TA.HDPIus Texture Analyser, Texture Technologies Corp, NY, USA) at 23±1 ^' C. in a speed of 2 mm/second. The elongation-at-break was obtained as the data at the sample breaking. Each value is measured three times for each example, and the average is reported. Elongation-at-break is measured at 25° C. After curing, the inventive cured non-resinous hydrosilylation-cured polyorganosiloxane composition is expected to have an elongation-at- break at 25° C. of > 10%, alternatively > 15%, alternatively > 20%, alternatively >25%, alternatively > 30%, alternatively > 40%, alternatively > 60%, alternatively > 100%, alternatively > 13% and < 65%, alternatively > 10% and < 75%. In contrast, a comparative example that is identical to the inventive example except that it contained a substantial and significant amount of a vinyl-functional MQ resin and it lacked, and was cured in the absence of, the present ingredient (B) multivinyl-functional silicon monomer, needs the vinyl- functional MQ resin to achieve any useful amount of elongation-at-break. But the cured comparative material contains MQ resin, which diminishes its optical transmittance. It would have been unexpected that the inventive cured non-resinous hydrosilylation-cured polyorganosiloxane composition would have a beneficial combination of properties of elongation-at-break and light transmittance.

[00118] Transmittance (of light) is measured on 3.85 mm samples initially after cure, the measurement using an ultraviolet-visible spectrophotometer as described below. Haze value is measured at 400 nm.

[00119] Light Transmittance: Characterization of light transmittance for examples was performed with an ultraviolet/visible light dual beam spectrophotometer (Perkin Elmer Lambda950 Spectrophotometer) operating at a medium scanning speed, 1 nm slit width, over a wavelength range from 200 to 800 nm. The "light transmittance" values thus generated are reported below (e.g., Table 1 ) and depicted in Figs. 2 to 4. The reported values are not corrected for surface reflections. (Surface reflections or so called Frensel reflections are due to refractive index differences between the air and the (silicone) test sample.)

[00120] Characterization of reflectivity corrected, internal light transmittance for examples was performed with an ultraviolet/visible light dual beam spectrophotometer with an integrating sphere attachment (Agilent Cary 500 Spectrophotometer). The spectrophotometer was operated at a medium scanning speed, 1 nm slit width, over a wavelength range from 360 to 740 nm. The reported "internal light transmittance" values have been corrected for surface reflections.

[00121] Non-invention ingredient 1 : is a vinyl-functional methylsiloxane resin of formula IV^r_jM^Qgg, where M is a trimethylsiloxane unit, M^i is a dimethylvinylsiloxane unit, and Q is a Q unit; and having Mn 5,000 g/mol and Mw 21 ,400 g/mol.

[00122] Ingredient (A-1 ): is a vinyl-functional polydimethylsiloxane fluid having vinyl groups only on terminal ends and a DP 65, and being of the formula M^Dgs, wherein M^i is a dimethylvinylsiloxane unit containing, on average per molecule, 1 vinyl group and 2 methyl groups; and D is a dimethylsiloxane unit containing 2 methyl groups.

[00123] Ingredient (A-2): is a vinyl-functional polydimethylsiloxane fluid having vinyl groups only on terminal ends and a DP 165, and being of the formula M^D-^, wherein

I |Vi and D are as defined for ingredient (A-1 ).

[00124] Ingredient (A-3): is a vinyl-functional polydimethylsiloxane fluid having vinyl groups only on terminal ends and a DP 500, and being of the formula M^DSQO, wherein M^i and D are as defined for ingredient (A-1 ). [00125] Ingredient (A-4): is a vinyl-functional polydimethylsiloxane fluid having vinyl groups only on terminal ends and a DP 900, and being of the formula M^Dgoo, wherein

M^i and D are as defined for ingredient (A-1 )

[00126] Ingredient (A-5): is a vinyl-functional polydimethylsiloxane gum having some vinyl groups on terminal ends and others at pendant locations within the siloxane chain and a DP 9500, and being of the formula D^-\ 509500, wherein M^i and D are as defined for ingredient (A-1 ) and _DVi is a methylvinylsiloxane unit.

[00127] Ingredient (A-6): is a vinyl-functional polydimethylsiloxane fluid having some vinyl groups on terminal ends and others at pendant locations within the siloxane chain and a DP 165, and being of the formula M^Vi2 D^Vi3D-| 62_> wherein M^Vi, D and D^Vi are as defined for ingredient (A-5).

[00128] Ingredient (B-1 ): is tetrakis(vinyldimethylsiloxy)silane.

[00129] Ingredient (C-1 ): is an SiH-functional organosiloxane crosslinker having, on average per molecule, 8 SiH groups.

[00130] Ingredient (C-2) is an SiH-functional organosiloxane crosslinker having, on average per molecule, 50 Si-H groups.

[00131] Ingredient (C-3) is an SiH-functional organosiloxane crosslinker having, on average per molecule, 4 Si-H groups.

[00132] Ingredient (D-1 ): is Karstedt's catalyst, a platinum-based hydrosilylation reaction catalyst with 5,100 parts per million (ppm) Pt.

[00133] Ingredient (G-1 ): 3,5-dimethyl-1 -hexyn-3-ol.

[00134] Comparative Example(s) (CE) used herein are non-invention example(s) that may help illustrate some benefits or advantages of the invention when compared to invention examples (IEx.), which follow later. Comparative Example(s) should not be deemed to be prior art.

[00135] Comparative Example (CE) 1 : prepared a mixture shown in Table 1 A later to give a resinous hydrosilylation-curable polyorganosiloxane composition of CE 1 . The non- inventive ingredient 1 (a vinyl-functional MQ polysiloxane resin), vinyl polymers (A-3) and (A- 4), hydrosilylation reaction catalyst (D-1 ), and hydrosilylation inhibitor (G-1 ) were added to a mixing vessel and mixed via asymmetric centrifugal mixing at 3400 rotations per minute for 30 seconds. Then the SiH-functional crosslinker (C-1 ) was added to the vessel, and the contents were again mixed via asymmetric centrifugal mixing at 3400 rotations per minute for 30 seconds. The resulting non-invention composition, which lacked a multivinyl-functional silicon monomer, was then poured into separate molds, and initially cured at 65° C. for 16 hours. Then the initially cured materials were removed from the molds, and subsequently cured again at 150° C. for 1 hour to give slabs of hydrosilylation-cured polyorganosiloxane of CE 1 . As detailed in Table 1 A, sample thicknesses ranging from 3.85 mm to 100.0 mm. The slabs were useful as planar lightguides. The slabs were used for light transmission analysis. Measured light transmittance of wavelength ranging from 300 to 700 nm through sample of 100.0 mm thickness, and the measurements are shown in Fig. 2. Measured light transmittance at a fixed wavelength of 400 nm through samples of 10.0 mm, 25.0 mm, 50.0 mm, and 100.0 mm, and the measurements are shown in Fig. 3. Measured light transmittance at a fixed wavelength of 400 nm through a sample of 8.70 mm thickness, and the measurement is shown in Fig. 4.

[00136] The invention is further illustrated by, and an inventive embodiment may include any combinations of features and limitations of, the non-limiting examples thereof that follow. The concentrations of ingredients in the compositions/formulations of the examples are determined from the weights of ingredients added unless noted otherwise.

[00137] Inventive Examples (lEx.) 1 to 5: prepared examples of the non-resinous hydrosilylation-curable polyorganosiloxane compositions shown in Tables 1 A and 1 B later to give a NRHCP Composition of lEx. 1 to 5, respectively. For each of lEx. 1 to 5, a different ingredient (A) first polyorganosiloxane polymer, or a combination of two different ingredients

(A) , were selected from ingredients (A-1 ), (A-2), (A-3), (A-4), (A-5), and (A-6); an ingredient

(B) multivinyl-functional silicon monomer that is ingredient (B-1 ); an ingredient (C) SiH functional organosiloxane crosslinker that is ingredient (C-1 ); a hydrosilylation reaction catalyst that is ingredient (D-1 ); and a hydrosilylation inhibitor (G) that is ingredient (G-1 ) were used as shown in Tables 1 A and 1 B. The ad rem ingredient(s) (A) and ingredients (B- 1 ), (D-1 ) and (G-1 ) for each example were added to a mixing vessel, and the vessel's contents were mixed via asymmetric centrifugal mixing at 3,400 rotations per minute for 30 seconds. Then the ingredient (C-1 ) was added to the vessel, and the vessel's contents were again mixed via asymmetric centrifugal mixing at 3,400 rotations per minute for 30 seconds to give the NRHCP Compositions of lEx. 1 to 5, respectively.

[00138] lEx. A to E: The compositions of lEx. 1 to 5 were then poured into separate molds, and initially cured at 65° C. for 16 hours. Then the initially cured materials were removed from the molds, and subsequently cured again at 150° C. for 1 hour to produce at least one slab (a plate, i.e., or molded article restricted in one dimension) of each of the respective compositions, respectively. The slabs of I Ex. A to E are useful as planar lightguides. The slabs were used for light transmission analysis. As detailed in Tables 1 A and 1 B, the slabs of lEx. A to E had different thicknesses. Overall, thicknesses ranged from 3.85 mm to 100.0 mm. The slabs were evaluated to determine how well the cured compositions lEx. 1 to 5 would transmit light when used as planar lightguides. Light transmittance at 400 nm and/or 460 nm is shown for I Ex A to D (made from I Ex. 1 to 4, respectively) at thickness indicated in Table 1 A later and for lEx. E (made from lEx. 5) in Table 1 B later. The 3.85 mm thick slabs of CEx 1 and lEx 2 were cured using the same conditions by being prepared in a hot press and cured at 150 ° C. for 75 minutes, which curing conditions were different than the curing conditions used for the thicker slabs (10.0 mm, 25.0 mm, 50.0 mm, and 100.0 mm).

[00139] Measured transmittance of light of wavelengths ranging from 300 to 800 nm through the samples lEx. A to E (made from lEx. 1 to 5, respectively) is provided in Figs 2 to 4. Reflectivity corrected internal light transmission for lEx. A (made from lEx. 1 ) versus light wavelengths ranging from 400 to 700 nm is shown in Fig. 5, and is presented for lEx A at the 400 nm wavelength of light in Table 1 A below. Light transmittance through lEx. A (made from lEx. 1 ) at wavelengths ranging from 400 to 800 nm is shown for a 100.0 mm sample of lEx. A in Fig. 2. Light transmittance through lEx. A (made from lEx. 1 ) at a fixed wavelength of 400 nm is shown as a function of sample thickness of 10.0 mm, 25.0 mm, 50.0 mm, and 100.0 mm in Fig. 3. Light transmittance at wavelengths in the range from 300 to 800 nm is shown for samples lEx. C, D and E (made from lEx. 3, 4 and 5) at 9.18 mm, 9.15 mm, 9.20 mm, respectively, and at 8.70 mm for CE 1 in Fig. 4. Reflectivity corrected, internal light transmittance of samples lEx. A (made from lEx. 1 ) and CE 1 at wavelengths in the range from 400 to 700 nm is shown for a 3.85 mm samples of lEx A and CEx 1 in Fig. 5.

[00140] Table 1 A: formulations of hydrosilylation-curable polyorganosiloxane compositions of CE 1 and lEx. 1 to 4 and corresponding slabs of lEx. A to D:

lEx 3 & lEx 4 &

CE 1 lEx 1 & lEx 2 & C D

Ingredient (wt%) A (wt%) B (wt%) (wt%) (wt%)

Ingredient (A-2) (165 DP, terminal

None 58.5 96.0 0.60 0.60 vinyls only)

Ingredient (A-3) (500 DP, terminal

40.7 None None None None vinyls only)

Ingredient (A-4) (900 DP, terminal

14.4 38.6 None None None vinyls only)

Ingredient (A-6) (DP 165, terminal and

None None None None 90.01 pendant vinyls)

Ingredient (B-1 ) None 0.70 1 .00 2.39 2.39

Ingredient (C-1 ) (cross linker) 5.4 2.00 2.84 7.30 7.30

Ingredient (D-1 ) (Pt catalyst) 0.0003 0.0003 0.0003 0.0003 0.0003

Ingredient (G-1 ) Hydrosilylation

0.20 0.20 0.19 0.13 0.13 Inhibitor

Sample thickness(es) (mm) 3.85, 3.85,

8.70, 9.23,

10.0, 10.0,

8.99 9.18 9.15 25.0, 25.0,

50.0, 50.0,

100.0 100.0

Transmittance (400 nm, %) @ sample 88.4 @ 92.0 @ 93.6 @ 93.5 @ 93.4 @ thickness (mm) 8.70 8.99 9.23 9.18 9.15

Transmittance (460 nm, %) @ sample 90.2 @

93.0 @ 94.3 @

None None thickness (mm) 8.70 8.99 9.23

Reflectivity-corrected Transmittance

99.6 None 98.4 None None (400 nm; %)

Elongation at break (%) _*

80 28 14 16

Maximum tensile strength (MPa) 1 1 _*

0.3 0.30 0.33

^*not tested.

[00141] In Table 1 A lEx. 1 includes two ingredients (A), which are (A-2) having a terminal-only vinyl functional polydimethylsiloxane with DP 165 and (A4) having a larger terminal-only vinyl functional polydimethylsiloxane with DP 900. lEx. 2 has one ingredient (A), which is (A-2), the terminal-only vinyl functional polydimethylsiloxane with DP 165. lEx. 3 includes two ingredients (A), wherein one ingredient (A-1 ) is a relatively small (DP 65), terminal-only vinyl functional polydimethylsiloxane fluid and the other ingredient (A-2) is a larger terminal-only vinyl functional polydimethylsiloxane of DP 165. lEx. 4 also includes two ingredients (A), wherein one ingredient (A-2) has terminal-only vinyl functional polydimethylsiloxane with a DP 165 and the other ingredient (A-6) has both terminal and pendant vinyl functional polydimethylsiloxane with DP 165. Thus, in some embodiments the inventive composition includes one ingredient (A), in other embodiments two ingredients (A). Additional embodiments are contemplated wherein there are three different ingredients (A) (e.g., (A-1 ), (A-2) or (A6), and (A3) or (A-4)).

[00142] Table 1 B: formulations of hydrosilylation-curable polyorganosiloxane composition of lEx. 5 and corresponding slab of lEx. E:

lEx 5 &

Ingredient E (wt%)

Elongation at break (%) 55

Maximum tensile strength (MPa) 0.45

[00143] In Table 1 B lEx. 5 includes an ingredient (A-5) that has some pendant and others terminal vinyl functionality in the polydimethylsiloxane and high average molecular weight (DP 9500).

[00144] Ten prophetic inventive examples are included herein that are identical to any one of lEx. 1 to 5 and lEx. A to E, respectively, except wherein the SiH-functional crosslinker (C-1 ) is replaced by an equivalent weight of the SiH-functional crosslinker (C-2). Another ten prophetic inventive examples are included herein that are identical to any one of lEx. 1 to 5 and lEx. A to E except wherein the SiH-functional crosslinker (C-1 ) is replaced by an equivalent weight of the SiH-functional crosslinker (C-3).

[00145] The inventive non-resinous hydrosilylation-curable polyorganosiloxane compositions may be cured to the inventive hydrosilylation-cured polyorganosiloxanes, which may are elastomeric and may be used as light guides. Further, the inventive hydrosilylation-cured polyorganosiloxanes are flexible enough to be bent multiple times rather than just one time as for a thermoset material (e.g., a poly(methyl methacrylate)). The lasting flexibility of the inventive hydrosilylation-cured polyorganosiloxanes enables them to be used in lighting applications where multiple bending forces are applied either during installation or during re-configuration or re-installation of the inventive optoelectronic devices or luminaires made therewith. In aspects where said flexibility is less desired, the lightguides made from the inventive hydrosilylation-cured polyorganosiloxanes may be disposed on a support.

[00146] Fig. 2 shows a graph of percent light transmittance at 300 to 800 nm expressed as a fraction versus visible light wavelength for a comparative example and for an inventive example of 100 mm thickness. As shown by the visible light transmittance data in Fig. 2, the inventive non-resinous hydrosilylation-curable polyorganosiloxane compositions may be cured to the inventive hydrosilylation-cured polyorganosiloxanes, which have significantly higher transmittance of visible light than the non-invention hydrosilylation-cured polyorganosiloxanes of CE 1 . [00147] Fig. 3 shows a graph of the percent light transmittance at 400 nm expressed as a fraction versus sample thickness for a comparative example and for an inventive example. As shown by the visible light transmittance data in Fig. 3, the inventive non- resinous hydrosilylation-curable polyorganosiloxane compositions may be cured to the inventive hydrosilylation-cured polyorganosiloxanes, which maintain significantly higher transmittance of light at 400 nm wavelength up to sample thicknesses of 100 mm than the non-invention hydrosilylation-cured polyorganosiloxanes of CE 1 .

[00148] Fig. 4 shows a graph of percent light transmittance at 300 to 800 nm expressed as a fraction versus visible light wavelength for a comparative example of 8.70 mm thickness, and for an inventive examples of thickness 9.18 mm, 9.15 mm, and 9.20 mm for lEx 3, 4, and 5 respectively. As shown by the visible light transmittance data in Fig. 4, the inventive non-resinous hydrosilylation-curable polyorganosiloxane compositions may be cured to the inventive hydrosilylation-cured polyorganosiloxanes, which have significantly higher transmittance of visible light than the non-invention hydrosilylation-cured polyorganosiloxanes of CE 1 .

[00149] Fig. 5 shows a graph of reflectivity-corrected percent transmittance at from 400 to 700 nm expressed as a fraction versus visible light wavelength for a comparative example and for an inventive example both of 3.85 mm thickness. As shown by the visible light transmittance data corrected for reflectance in Fig. 5, the inventive non-resinous hydrosilylation-curable polyorganosiloxane compositions may be cured to the inventive hydrosilylation-cured polyorganosiloxanes, which have significantly higher transmittance of visible light than the non-invention hydrosilylation-cured polyorganosiloxanes of CE 1 .

[00150] The below claims are incorporated by reference here, and the terms "claim" and "claims" are replaced by the term "aspect" or "aspects," respectively. Embodiments of the invention also include these resulting numbered aspects.

Claims

What is claimed is:

1 . A non-resinous hydrosilylation-curable polyorganosiloxane composition consisting essentially of non-resinous ingredients that comprise non-resinous ingredients (A), (B), (C), and (D):

(A) a first polyorganosiloxane polymer having a weight average molecular weight of from 1 ,000 to 1 ,000,000 grams per mole and containing vinyl groups only on terminal ends of the first polyorganosiloxane polymer, only on pendant positions of the first polyorganosiloxane polymer, or on terminal ends and pendant thereon (i.e., some on terminal ends and others pendant thereon), and having on average at least two vinyl groups per molecule and a pendant vinyl content, when present, of from 0.01 to 5 weight percent based on weight of ingredient (A);

(B) a multivinyl-functional silicon monomer containing 3 or more vinyl groups up to per vinyl substitution and being an organosiloxane having a molecular weight of from 280 to 2,000 grams per mole or being an organosilane having a molecular weight of from 124 to 2,000 g/mol;

(C) a SiH functional organosiloxane crosslinker having on average at least two SiH functional groups per molecule; and

(D) a hydrosilylation reaction catalyst;

wherein the total SiH-to-vinyl molar ratio of the non-resinous hydrosilylation- curable polyorganosiloxane composition is from 0.1 to 10.

2. The non-resinous hydrosilylation-curable polyorganosiloxane composition of claim 1 wherein the vinyl groups of (A) the first polyorganosiloxane polymer are only on terminal ends of the first polyorganosiloxane polymer; or wherein the first polyorganosiloxane polymer consists of only linear molecules, which may be straight chain or branched chain; or wherein the first polyorganosiloxane polymer consists of only straight chain linear molecules; or wherein the vinyl groups of (A) the first polyorganosiloxane polymer are only on terminal ends of the first polyorganosiloxane polymer and the first polyorganosiloxane polymer consists of only straight chain linear molecules; or wherein some of the vinyl groups of (A) are on terminal ends and others at pendant positions of the first polyorganosiloxane polymer.

3. The non-resinous hydrosilylation-curable polyorganosiloxane composition of claim 1 or 2 wherein (B) the multivinyl-functional monomer is an organosiloxane of formula (I): (H₂C=CHR₂SiO)4Si, wherein each R independently is (C-| -C₆)alkyl, H₂C=CH-, or phenyl; or an organosiloxane of formula (II): (H2C=CHR₂SiO)3Si-Si(OSiR2CH=CH2)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl; or an organosiloxane of formula (III): (H2C=CHR2SiO)3Si-SiR2-Si(OSi R2CH=C 1-12)3, wherein each R independently is (Ci -Ce)alkyl, H₂C=CH-, or phenyl; or

wherein (B) the multivinyl-functional monomer is an organosilane of formula (IV): (H₂C=CHR₂Si)4Si, wherein each R independently is (C-| -CeJalkyl, H₂C=CH-, or phenyl; or an organosilane of formula (V): (H2C=CHR2Si)3Si-Si(SiR2CH=CH2)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl; or an organosilane of formula (VI): (H2C=CHR2Si)3Si-SiR2-Si(SiR2CH=C 1-12)3, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl; or an organosilane of formula (VII): (H2C=CHR2)4Si, wherein each R independently is (C-| -Ce)alkyl,

H₂C=CH-, or phenyl; or an organosilane of formula (VIII): (H₂C=CHR₂Si)3SiR, wherein each R independently is (C-| -Cg)alkyl, H2C=CH-, or phenyl.

The non-resinous hydrosilylation-curable polyorganosiloxane composition of any one of the preceding claims further comprising at least one of a non-resinous ingredient (E), a non-resinous ingredient (F) an adhesion promoter for promoting adhesion to an organic polymer, or a non-resinous ingredient (G) a hydrosilylation inhibitor for inhibiting ingredient (D) the hydrosilylation reaction catalyst; wherein the non- resinous ingredient (E) is a second polyorganosiloxane polymer having vinyl groups and a weight average molecular weight of from 1 ,000 to < 40,000 grams per mole and containing vinyl groups only on terminal ends of the second polyorganosiloxane polymer or some on terminal ends and others pendant thereon, and having on average at least two vinyl groups per molecule and a pendant vinyl content, when present, of from 0.01 to 1 .0 weight percent based on weight of ingredient (E), wherein the Degree of Polymerization (DP) of ingredient (E) is less than the DP of ingredient (A).

A hydrosilylation-cured polyorganosiloxane prepared by curing the non-resinous hydrosilylation-curable polyorganosiloxane composition of any one of the preceding claims.

6. The hydrosilylation-cured polyorganosiloxane of claim 5 having a reflectivity- corrected light transmittance of greater than 99.50 percent when tested using a 3.85 millimeters sample with light at 400 nanometers or from 400 to 700 nanometers.

7. The hydrosilylation-cured polyorganosiloxane of claim 5 or 6 further having an elongation-at-break greater than 10 percent at 25 degrees Celsius, a maximum tensile strength of at least (i.e., greater than or equal to) 0.2 megapascals (MPa), or both.

8. A free-standing light guide comprising the hydrosilylation-cured polyorganosiloxane of any one of claims 5 to 7.

9. An optoelectronic device comprising at least one light element and the free-standing light guide of claim 8 wherein the free-standing light guide is configured to transmit light when light is emitted from the light element

10. A luminaire device comprising the optoelectronic device of claim 9 and a power supply that is configured for powering the at least one light element.

1 1 . A composite light guide comprising the hydrosilylation-cured polyorganosiloxane of any one of claims 5 to 7 disposed on a support.

12. The composite light guide of claim 1 1 , wherein the support is configured to contain morphological features or reflective features for extracting light from the composite light guide when light is present therein.

13. An optoelectronic device comprising at least one light element and the composite light guide of claim 1 1 or 12, wherein the composite light guide is configured to transmit light when light is emitted from the light element.

14. A luminaire device comprising the optoelectronic device of claim 13 and a power supply that is configured for powering the at least one light element.

15. A hydrosilylation-cured polyorganosiloxane having an elongation-at-break of greater than 10% and having a reflectivity-corrected light transmittance of greater than 99.50 percent when tested using a 3.85 millimeters sample with light at 400 nanometers or at from 400 to 700 nanometers.

16. A method of transmitting light comprising visible light to a light-receiving element via a light guide made of the hydrosilylation-cured polyorganosiloxane of any one of claims 5 to 7 and defining an optical pathway therethrough, wherein the optical pathway is linear or non-linear, wherein the optical pathway has a proximal end where light is introduced into the light guide and a distal end where transmitted light is to exit the light guide, wherein the proximal and distal ends of the optical pathway are in optical communication with each other via the optical pathway and wherein the distal end of the optical pathway of the light guide is disposed opposite the light- receiving element such that the light guide is configured for directing transmitted light exiting the light guide to the light-receiving element, the method comprising:

Introducing light comprising visible light into the light guide at the proximal end of the optical pathway thereof;

allowing the introduced light to transmit along the optical pathway through the light guide to give a transmitted light comprising visible light at the distal end of the optical pathway; and

allowing the transmitted light to exit the light guide at the distal end of the optical pathway and be received by the light-receiving element.

17. The method of claim 16 wherein the light-receiving element is a surface of an object and the method further comprises illuminating the surface; or

wherein the light-receiving element is a light reflector, light diffuser, light attenuator, or a converter device for converting light comprising visible light into an electrical signal readable by an electronic device.