JP2018532864A - Curable silicone composition - Google Patents

Abstract

The composition, which is a curable silicone composition, has an average of at least two alkenyl groups in each molecule, has a degree of polymerization of from about 25 to about 10,000, and from about 20% to about 50% by weight of the organopolysiloxane. % By weight alkenyl-functional dialkylpolysiloxane; and SiO _4/2 units, R ¹ ₂ R ² SiO _1/2 units, and R ¹ ₃ SiO _1/2 units, wherein R ¹ is C _1-10 alkyl Yes, R ² is alkenyl. An alkenyl functional organopolysiloxane resin having an alkenyl group in the range of about 1.0% to about 4.5% by weight and an OH content of about 0.2% to about 2.0%. An alkenyl-functional organopolysiloxane resin having a weight percent molecular weight of about 2,000 g / mole to about 22,000 g / mole; a crosslinker; and a catalytic amount of a hydrosilylation catalyst. And including.

Description

  The subject described in the present specification relates to a curable silicone composition, a method for producing the curable silicone composition, and a cured product from which a highly transparent cured silicone material is obtained.

  In the medical, electronics, and lamp industries, optimally balanced mechanical and optical properties enable superior device functions and performance. In these industries, resin reinforced silicone elastomers are widely used to achieve or improve mechanical performance. It has been speculated and widely accepted by those skilled in the art that high mass average molecular weight (<22,000 g / mol) alkenyl functional organopolysiloxane resins need to be included to provide sufficient reinforcement to these silicone elastomers. ing.

  It has also been demonstrated for some time that alkenyl-functional organopolysiloxane resins provide excellent mechanical reinforcement of the silicone elastomer and then the resulting cured material. However, as the amount of alkenyl-functional organopolysiloxane resin increases in the composition, the optical properties decrease due to agglomeration and concentration increase of the resin particles, resulting in light scattering and concomitant haze. This haze is disadvantageous in many applications where the functionality or efficiency of the device is enabled by light transmission.

  The compositions obtained herein show a significant and unexpected improvement in this balanced performance characteristic. More specifically, the present invention is contrary to conventional common sense, which means that mechanical strength and light transmittance are reduced to alkenyl having an extremely low mass average molecular weight (lower than 22,000 g / mol). The use of functional organopolysiloxane resins can be balanced, maintained and improved.

  Furthermore, these low weight average molecular weight alkenyl functional organopolysiloxane resins are available in high concentrations in the composition relative to the concentration of alkenyl functional organopolysiloxane polymers in the composition, thereby providing Excellent surface properties are obtained which are also desirable for optical and electronic applications. Specifically, these compositions provide excellent visible light transmittance and mechanical properties, while reducing surface tack and making processing properties suitable.

The curable silicone composition of the present invention comprises an organopolysiloxane, a crosslinker, and a catalytic amount of a hydrosilylation catalyst. The organopolysiloxane has an alkenyl functional polymer and an alkenyl functional resin. The polymer has an average of at least two alkenyl groups in each molecule, has a degree of polymerization in the range of about 25 to about 10,000, and is present in the range of about 20% to about 50% by weight of the organopolysiloxane. To do. The resin is SiO _4/2 units, R ¹ ₂ R ² SiO _1/2 units, and R ¹ ₃ SiO _1/2 units [wherein R ¹ is C _1-10 alkyl and R ² is alkenyl. . ]. The resin has alkenyl in the range of about 1.0% to about 4.5% by weight, the hydroxyl content on the silicon is in the range of about 0.2% to about 2.0% by weight, The average molecular weight ranges from about 2,000 g / mol to about 22,000 g / mol.

FIG. 5 shows the overall light transmission measured as a function of wavelength using the optical evaluation sample preparation C for an example of 0.28 centimeter (cm) thickness considered herein. The optical haze measured as a function of wavelength using the optical evaluation sample preparation C for the 0.28 cm thick example discussed herein is shown. The light transmission measured as a function of wavelength using the optical evaluation sample preparation D is shown for the 1.0 cm thickness example discussed herein. Figure 2 shows the overall light transmission measured as a function of wavelength using optical evaluation sample preparation B for the 3.2 cm thickness example discussed herein.

  The exemplary composition described herein is a curable silicone composition that includes an organopolysiloxane (A) as a basic component of the composition. The organopolysiloxane includes an alkenyl functional organopolysiloxane polymer (A-1) and an alkenyl functional organopolysiloxane resin (A-2).

In one exemplary embodiment, (A-1) has an average of at least two alkenyl groups in each molecule. The polymer form of (A-1) has a substantially linear molecular structure, but a part of the molecular chain may be somewhat branched. Examples of alkenyl in (A-1) include, but are not limited to, vinyl, alkyl, allyl, isopropenyl, butenyl, pentenyl, hexenyl and cyclohexenyl, or a combination of any two or more thereof. Examples of the bonding position of the alkenyl group may include a terminal position and / or a side chain position on the molecular chain, but are not particularly limited thereto. Examples of the alkyl in (A-1) include C _1-10 alkyl [methyl, ethyl, propyl, cyclopentyl, cyclohexyl and the like] or a combination of any two or more thereof, but is not particularly limited thereto.

  In one example embodiment, (A-1) is an alkenyl-functional dialkylpolysiloxane having an average of at least two alkenyl groups in each molecule. In another example embodiment, (A-1) is a diorganopolysiloxane, including dimethylpolysiloxane having both ends of the molecular chain end-capped with dimethylvinylsiloxy groups, and both ends of the molecular chain are Dimethylsiloxane-methylvinylsiloxane copolymer end-capped with dimethylvinylsiloxy groups, methylvinylpolysiloxane end-capped with trimethylsiloxy groups at both ends of the molecular chain, end-capped with trimethylsiloxy groups at both ends of the molecular chain A stopped dimethylsiloxane-methylvinylsiloxane copolymer or a combination of any two or more thereof may be mentioned, but is not particularly limited thereto.

  In one example embodiment, the viscosity of (A-1) at 25 ° C. is from about 100 millipascal seconds (mPa · s) to about 2,000,000 mPa · s, more specifically about 1,500 mPa · s. S to about 100,000 mPa · s, or even more specifically about 2,000 mPa · s to about 80,000 mPa · s. When (A-1) is a mixture of two or more alkenyl functional polyorganosiloxanes and can include high and low viscosity alkenyl functional polyorganosiloxanes, the viscosity at 25 ° C. of the mixture is about 1 000 mPa · s to about 200,000 mPa · s.

  The content ratio of (A-1) in the composition ranges from about 20% to about 50% by weight of (A), or more specifically from about 25% to about 50% by weight of (A). An amount, or even more specifically an amount from about 30% to about 50% by weight. At least some of the reasons for this are that if the amount of (A-1) is below the lower limit of the stated range, the flexibility of the cured silicone material obtained by curing of the composition tends to decrease, When the amount of (A-1) exceeds the upper limit of the described range, it is mentioned that the hardness of the cured silicone material obtained by curing of the present composition is likely to decrease. When the content ratio of (A-1) in (A) is 30% by mass to 50% by mass, the content ratio of (A-1) in (A) is 20% by mass to 30% by mass. Compared to certain compositions, favorable processing characteristics including viscosity and flowability are obtained.

In one example embodiment, the vinyl functional polydimethylsiloxane is a fluid having vinyl groups only at the ends and the average degree of polymerization of the polysiloxane chain is from about 25 to about 10,000, for example, the formula is M ^Vi ₂ D ₂₅ to M ^Vi ₂ D _10,000 [wherein M ^Vi is a siloxane unit containing an average of one vinyl group and two methyl groups, and D is a siloxane unit having two methyl groups. is there. ].

In another example embodiment, the vinyl functional polydimethylsiloxane is a fluid having vinyl groups only at the ends, the average degree of polymerization of the polysiloxane chain is 900, and the formula is M ^Vi ₂ D ₉₀₀ [wherein M ^Vi is a siloxane unit containing an average of one vinyl group and two methyl groups, and D is a siloxane unit having two methyl groups. ].

In another example embodiment, the vinyl functional polydimethylsiloxane is a fluid having vinyl groups only at the ends, the polysiloxane chain has an average degree of polymerization of 500, and the formula is M ^Vi ₂ D ₅₀₀ , wherein M ^Vi is a siloxane unit having an average of one vinyl group and two methyl groups, and D is a siloxane unit having two methyl groups. ].

In another example embodiment, the vinyl functional polydimethylsiloxane is a fluid having vinyl groups only at the ends, the polysiloxane chain has an average degree of polymerization of 300, and the formula is M ^Vi ₂ D ₃₀₀ , wherein M ^Vi is a siloxane unit having an average of one vinyl group and two methyl groups, and D is a siloxane unit having two methyl groups. ].

In a further example embodiment, the vinyl functional polydimethylsiloxane is a fluid having vinyl groups only at the ends, the average degree of polymerization of the polysiloxane chain is 165, and the formula is M ^Vi ₂ D ₁₆₅ M ^Vi is a siloxane unit having an average of one vinyl group and two methyl groups, and D is a siloxane unit having two methyl groups. ].

In a further embodiment, the vinyl-functional polydimethylsiloxane is a fluid having vinyl groups only at the ends, the polysiloxane chain has an average degree of polymerization of 27, and the formula is M ^Vi ₂ D ₂₇ , where M ^Vi Is a siloxane unit having on average one vinyl group and two methyl groups, and D is a siloxane unit having two methyl groups. ].

  In some cases, when the degree of polymerization of the organopolysiloxane is 900 or less, a sufficient viscosity cannot be obtained, and the organopolysiloxane having a viscosity exceeding 1,000,000 mPa · s And / or vinyl may be arranged in pendant positions and / or side chain positions and included in the composition, but is not particularly limited thereto. For example, when the viscosity of (A-1) at 25 ° C. is less than 1,000 mPa · s (cP), the material obtained by the cured composition tends to be unsatisfactory in flexibility and / or tensile strength. Tends to be low. In this example, a suitable amount of high viscosity organopolysiloxane can be added to the composition to obtain satisfactory flexibility and / or high tensile strength.

In one example embodiment, the high viscosity polyorganosiloxane has vinyl groups only at the ends, the average degree of polymerization of the polysiloxane chain is ₂₀₀₀ to 15,000, and the formula is from M ^Vi ₂ D ₂₀₀₀ to M ^Vi ₂ D _15,000 [wherein M ^Vi is a siloxane unit containing an average of one vinyl group and two methyl groups, and D is a siloxane unit having two methyl groups. ].

In another example embodiment, the high viscosity polyorganosiloxane has vinyl groups only at the ends, has an average degree of polymerization of 9,463, and the formula is M ^Vi ₂ D _9,463 , where M ^Vi is , On average, a siloxane unit having one vinyl group and two methyl groups, and D is a siloxane unit having two methyl groups. ].

In yet another example embodiment, the high viscosity polyorganosiloxane has vinyl groups at the terminal and pendant positions, the polysiloxane chain has an average degree of polymerization of 9,437, includes D and D ^Vi units, and has the formula M ^Vi ₂ D ^Vi ₁₈₇ D _{9,250 wherein} M ^Vi is a siloxane unit having an average of one vinyl group and two methyl groups, and D ^Vi is an average of one vinyl group and one It is a siloxane unit having a methyl group, and D is a siloxane unit having two methyl groups. ].

Moreover, as above-mentioned, organopolysiloxane also contains an alkenyl functional resin (A-2). (A-2) is SiO _4/2 units (“Q” units), R ¹ ₂ R ² SiO _1/2 units (alkenyl and alkyl functional “M” units), and R ¹ ₃ SiO _1/2 Units (alkyl functional “M” units) wherein R ¹ is C _1-10 alkyl and R ² is alkenyl. ]including. In one example embodiment, the vinyl content in (A-2) is about 1.0 wt% to about 4.5 wt%, and the OH content by silanol groups is about 0.2 wt% to about 4.5 wt%. The weight average molecular weight is about 2,000 g / mol to about 22,000 g / mol. More specifically, the vinyl content contained in (A-2) is about 2.0 wt% to about 4.0 wt%, and the silanol group OH content is about 0.4 wt% to about 1. wt%. The weight average molecular weight is about 2,000 g / mol to about 20,000 g / mol. More specifically, the vinyl content in (A-2) is about 2.8 wt% to about 3.8 wt%, and the OH content due to silanol groups is about 0.6 wt% to about 1 wt. 0.5% by weight, and the mass average molecular weight is from about 2,000 g / mole to about 15,000 g / mole.

In one example embodiment, (A-2) has a weight average molecular weight of about 3400 g / mol, a vinyl group content of 3.3% by weight, and a hydroxyl group content of 1.1% by weight (0 .044 mol OH / mol Si), and the ratio of the total number of moles of R ¹ ₂ R ² SiO _1/2 units and R ¹ ₃ SiO _1/2 units to 1 mol SiO _4/2 units is 1. 02.

In another example embodiment, the mass average molecular weight of (A-2) is 3,380 g / mol, the vinyl group content is 1.5% by mass, and the hydroxyl group content is 1.1% by mass ( 0.045 mol OH / mol Si), and the ratio of the total number of moles of R ¹ ₂ R ² SiO _1/2 units and R ¹ ₃ SiO _1/2 units to 1 mol of SiO _4/2 units is 1 .00.

In a further embodiment, the mass average molecular weight of (A-2) is 3,410 g / mol, the vinyl group content is 2.3% by mass, and the hydroxyl group content is 1.0% by mass (0. 040 mol OH / mol Si), and the ratio of the total number of moles of R ¹ ₂ R ² SiO _1/2 units and R ¹ ₃ SiO _1/2 units to 1 mol of SiO _4/2 units is 0.996. It is.

In another example embodiment, the mass average molecular weight of (A-2) is 3,460 g / mol, the vinyl group content is 3.1% by mass, and the hydroxyl group content is 1.2% by mass ( 0.046 mol OH / mol Si), and the ratio of the total number of moles of R ¹ ₂ R ² SiO _1/2 units and R ¹ ₃ SiO _1/2 units to 1 mol of SiO _4/2 units is 0 .988.

In one embodiment, the mass average molecular weight of (A-2) is 3,360 g / mol, the vinyl group content is 1.6% by mass, and the hydroxyl group content is 1.0% by mass. 039 mol OH / mol Si) and the ratio of the total number of moles of R ¹ ₂ R ² SiO _1/2 units and R ¹ ₃ SiO _1/2 units to 1 mol of SiO _4/2 units is 1.00 It is.

In another example embodiment, the mass average molecular weight of (A-2) is 3,880 g / mol, the vinyl group content is 3.4% by mass, and the hydroxyl group content is 0.8% by mass ( 0.034 mol OH / mol Si), and the ratio of the total number of moles of R ¹ ₂ R ² SiO _1/2 units and R ¹ ₃ SiO _1/2 units to 1 mol of SiO _4/2 units is 1 .00.

For comparison, in an embodiment not according to the present invention, the weight average molecular weight of the organopolysiloxane resin is 23,400 g / mol, the vinyl group content is 2.0% by mass, and the hydroxyl group content is 1.9. % By mass (0.074 mol OH / mol Si) of the total moles of R ¹ ₂ R ² SiO _1/2 units and R ¹ ₃ SiO _1/2 units to 1 mol of SiO _4/2 units Is 0.848. When incorporated in the formulation, the organopolysiloxane resin provides sufficient mechanical properties, but when the content of (A-2) exceeds 50% of (A), the light transmittance is inferior.

In another non-inventive embodiment, the organopolysiloxane resin has a weight average molecular weight of 26,000 g / mol, a vinyl group content of 4.0% by weight, and a hydroxyl group content of 1.6% by weight. % (0.063 mol OH / mol Si) and the ratio of the total number of moles of R ¹ ₂ R ² SiO _1/2 units and R ¹ ₃ SiO _1/2 units to 1 mol of SiO _4/2 units is 0.882. When incorporated in the formulation, the organopolysiloxane resin provides sufficient mechanical properties, but when the content of (A-2) exceeds 50% of (A), the light transmittance is inferior.

  In one example embodiment, the amount of (A-2) present is in the range of about 50% to about 80% by weight of component (A), or more preferably about 50% by weight of component (A). To about 75% by weight, or particularly preferably in the range of about 50% to about 70% by weight of component (A).

  As described above, the curable silicone composition of the present invention further includes a crosslinking agent (B), which includes an organohydrogenoligosiloxane, an organohydrogenpolysiloxane, a polyorganohydrogensiloxane, or any two of these. Although a combination of two or more is mentioned, it is not particularly limited to these.

  In one example embodiment, (B) has the following parameters [silicon hydride (SiH) content, molecular structure and composition (eg, M, D, T, Q and ratios thereof, pendant functional groups, molecules Any two or more polyorganos differing in at least one of: configuration, branch of polymer side chain), viscosity, average molecular weight and molecular weight distribution, number of siloxane units, and arrangement of two or more different siloxane units] It is a combination of hydrogen siloxane.

  In another example embodiment, (B) is a SiH functional organosiloxane crosslinker having an average of at least two silicon-bonded hydrogen atoms per molecule, and (B) is a single polyorganohydrogen. It is selected from siloxanes or combinations of two or more polyorganohydrogensiloxanes that differ in at least one of the following [structure, viscosity, average molecular weight, number of siloxane units, and sequence].

In one example embodiment, (B) is an organopolysiloxane having an average of at least three silicon-bonded hydrogen atoms in each molecule, and the silicon-bonded group other than silicon-bonded hydrogen is a C _1-10 alkyl. The amount of silicon-bonded hydrogen in (B) is from about 0.4 mol to about 4.0 mol per mol of total alkenyl in component (A). In this embodiment, (B) comprises (B-1) silicon-bonded hydrogen of at least about 0.7% by weight, and SiO _4/2 units and HR ³ ₂ SiO _1/2 units [wherein RR ³ Is C _1-10 alkyl. About 5% by weight of component (B) in a ratio ranging from about 1.5 moles to about 3.8 moles of HR ³ ₂ SiO _1/2 units per mole of SiO _4/2 units To about 100% by weight (about 5% to about 95% by weight) of the organopolysiloxane, and (B-2) silicon-bonded hydrogen is at least about 0.1% by weight, and there are silicon-bonded groups other than silicon-bonded hydrogen. , C _1-10 alkyl, 0 to 50% by weight of the linear organopolysiloxane of the component (B).

  As described above, the curable silicone composition of the present invention further includes a catalytic amount of a hydrosilylation catalyst to obtain a highly transparent cured silicone material (C). In one example embodiment, (C) is added in an amount sufficient to promote curing of the composition. (C) is known in the art and may contain a commercially available hydrosilylation catalyst. Suitable hydrosilylation catalysts include platinum group metals including platinum, rhodium, ruthenium, palladium, osmium or iridium metals, or organometallic compounds thereof, and combinations of any two or more thereof, It is not specifically limited to these. In a further embodiment, (C) is a hydrosilylation catalyst including platinum black, platinum compounds [chloroplatinic acid, chloroplatinic acid hexahydrate, reaction product of chloroplatinic acid and a monohydric alcohol, Platinum bis (ethyl acetoacetate), platinum bis (acetylacetonate), platinum dichloride, etc.], and complexes of platinum compounds with olefins or low molecular weight organopolysiloxanes, or platinum microencapsulated in a matrix or core-shell structure Compounds.

  In one example embodiment, (C) is a hydrosilylation catalyst solution, including a complex of 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane with platinum; And a complex of platinum with a low molecular weight organopolysiloxane. These complexes may be microencapsulated in a resin matrix. In an alternative embodiment, the catalyst includes a complex of 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane with platinum.

  Examples of suitable hydrosilylation catalysts for component (C) include, for example, U.S. Pat. Nos. 3,159,601, 3,220,972, 3,296,291, and 3,419. No. 3,593, No. 3,516,946, No. 3,814,730, No. 3,989,668, No. 4,784,879, No. 5,036,117 and No. 5,175,325 and European Patent No. 0347895 (B). Microencapsulated hydrosilylation catalysts and methods for their preparation are illustrated in US Pat. Nos. 4,766,176 and 5,017,654. In another embodiment, the platinum catalyst is prepared as a solution having a concentration of about 100 ppm to about 100,000 ppm of vinyl functional organopolysiloxane so that the total concentration is about 0 when diluted in the final formulation. .1 ppm to about 100 ppm.

  Optionally, the curable silicone composition may further comprise one or more additional components (D). Examples of the additional component or the combination of components (D) include a hydrosilylation reaction retarder, a release agent, a filler, an adhesion promoter, a heat stabilizer, a flame retardant, a reactive diluent, an antioxidant, or these Any combination of two or more of the above may be mentioned.

  In one embodiment, (D) includes a retarder for hydrosilylation. For example, (D) is a reaction retarder for adjusting the curing rate of the curable silicone composition. In one embodiment, (D) includes alkyne alcohol [2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynyl-1-cyclohexanol, Phenylbutynol, or a combination of any two or more thereof], eneyne compounds [for example, 3-methyl-3-pentacene-1-yne or 3,5-dimethyl-3-hexen-1-yne], And, for example, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclo Although tetrasiloxane or benzotriazole is mentioned, it is not specifically limited to these. The content ratio of the reaction retarder in the curable silicone composition is not particularly limited, and the content ratio may be appropriately selected as a function of the molding method and the curing conditions. In one embodiment, the amount of (D) present is from about 10 parts per million (ppm) to about 10,000 parts per million (ppm), more specifically, based on the total weight of the curable silicone composition. Specifically, it is about 100 ppm to about 5,000 ppm.

  In one embodiment, (D) is a reaction retardant for hydrosilylation and its abundance is from about 10 ppm to about 5,000 ppm, based on the total weight of the composition.

  In one embodiment, the curable silicone composition is cured to form a highly transparent cured silicone product. The curable silicone composition can be cured into a cured silicone product having desired properties, such as hardness, tensile strength, elongation, light transmittance, and / or any one of two or more of these Suitable combinations are mentioned. In a further embodiment, the curable silicone composition is cured to form a cured silicone product that includes a substrate that forms a single article with a cured silicone layer.

  In one embodiment, the cured silicone product has a hardness (Shore A) of about 5 to about 95, more specifically a Shore hardness (Shore A) of about 10 to about 95, more specifically a hardness. (Shore A) is from about 20 to about 90, and even more specifically, the hardness (Shore A) is from about 30 to about 90.

  In one embodiment, the cured silicone product has a tensile strength greater than about 3 megapascals (MPa), and more specifically, the tensile strength is greater than about 5 MPa.

  In one embodiment, the cured silicone product has a light transmission (without correction for surface reflection loss) greater than about 80% at a wavelength of 598 nm as a thickness of 2.54 cm, more specifically, the light transmission is about More than 85%, and even more specifically, the light transmission is higher than about 90% at a wavelength of 598 nm as a thickness of 2.54 cm.

  In another embodiment, the overall light transmission of the curable silicone product (according to ASTM test method E1348-11, without correction for surface reflection loss) is about 80% at a wavelength of 598 nm as a thickness of 3.2 cm. High, more specifically, greater than about 85% at a wavelength of 598 nm as a thickness of 3.2 cm, and more specifically, greater than about 90% at a wavelength of 598 nm as a thickness of 3.2 cm.

In another embodiment, the light attenuation coefficient of the curable silicone product is less than about 0.01 cm ⁻¹ at a wavelength of 598 nm as measured by the cut back method.

  In one embodiment, the composition has a hardness (Shore A) of about 60 to about 95, a tensile strength greater than about 3 MPa, and an overall light transmission (according to ASTM test method E1348-11, surface reflection loss Without correction) is higher than about 90% at 598 nm as a thickness of 3.2 cm.

  In one embodiment, an exemplary method of making the composition comprises (A-1) a vinyl-functional polyorganosiloxane and (A-2) an organopolysiloxane resin comprising (A) an organopolysiloxane, (B) a crosslink. Mixing the solution containing the agent and (C) the reaction catalyst. In another embodiment, mixing the solution comprises (D) adding a reaction retardant.

  In certain embodiments, the method further comprises heating the composition to form a cured product. The step of heating may further include, for example, an injection molding method, a transfer molding method, an integral molding method, an extrusion molding method, an over molding method, a compression molding method, and a casting molding method. A monolithic or extruded article that includes a lens, a light guide, a light transmissive adhesive layer, or other optical element.

In one exemplary embodiment, the curable silicone composition comprises 100 parts by weight of (A) an alkenyl-containing organopolysiloxane, which (A) has an average of at least two alkenyl groups in each molecule. And (A-1) a dialkylpolysiloxane of about 20% to about 50% by weight of component (A) having a viscosity at 25 ° C. of about 300 mPa · s to about 2,000,000 mPa · s, and , _{SiO 4/2} ^units, _R 1 _{² R} ² _{SiO 1/2} units, and ^R ₁ 3 _{SiO 1/2} units ^{wherein, R} _{1 2} is _{C 1-10} alkyl, ^{R 2} is alkenyl. The vinyl content in the alkenyl group is in the range of about 1% to about 4.5% by weight and the weight average molecular weight is about 2,000 g / mole to about 22,000 g / mole. (A) from about 50% to about 80% by weight of (A-2) an organopolysiloxane in the form of an alkenyl-containing resin, and (B) the organopolysiloxane is at least on average in each molecule Silicon bonds in component (B) having two silicon-bonded hydrogen atoms, wherein the silicon-bonded group other than silicon-bonded hydrogen is C _1-10 alkyl and per mole of total alkenyl in component (A) The amount of hydrogen is from about 0.4 moles to about 4 moles, the component (B) is an organopolysiloxane having at least about 0.7 weight percent silicon-bonded hydrogen, and SiO _{4 / 2} Position and ^HR ₃ 2 _{SiO 1/2} units _wherein, ^{R 3} is _{C 1-10} alkyl. About 5 of component (B-1) in a ratio ranging from about 1.50 moles to about 3.80 moles of HR ³ ₂ SiO _1/2 units per mole of SiO _4/2 units % By weight to about 95% by weight of (B-1) organopolysiloxane, as well as silicon-bonded hydrogen is at least about 0.1% by weight and the silicon-bonded group other than silicon-bonded hydrogen is C _1-10 alkyl. (B-2) a linear organopolysiloxane comprising 0% by weight to about 50% by weight of component (B), and (C) a catalytic amount of hydrosilylation reaction catalyst, A highly cured silicone material (C) is obtained.

  The composition exhibits excellent optical and mechanical properties suitable for the production of light transmissive optical and electronic devices. The combination of light transmission and mechanical toughness is derived from the preferred mass average molecular weight of the resin form of the organopolysiloxane. When the mass average molecular weight of the organopolysiloxane in the resin form (A-2) exceeds 22,000 g / mol, the optical transparency of the obtained cured composition is such that the content of (A-2) is a constituent component ( When it exceeds 50% by mass of A), it decreases. Similarly, when the mass average molecular weight of the organopolysiloxane (A-2) in the resin form is less than 2000 g / mol, the mechanical toughness of the obtained cured composition is such that the content ratio of (A-2) is a constituent component ( When it exceeds 50% by mass of A), it decreases. Therefore, control of the weight average molecular weight of the organopolysiloxane in the resin form is essential in order to achieve the optical and mechanical properties required for optical and electronic equipment.

  An optical instrument by a method comprising using the composition as described herein, shaping the composition, and curing the composition to form a cured product, eg, for use in an optical instrument. Components can be manufactured. The composition is formed by injection molding, transfer molding, integral molding, extrusion molding, overmolding, compression molding, or casting molding, and molding, integral molding, dispensing, Sealed articles or extruded articles can be produced. The method of shaping the composition will depend on a variety of factors, including the size and / or shape of the optical instrument being manufactured and the selected composition.

  In one embodiment, the curable composition can be used for electronic or optical instrument applications. The electronic device or optical device may be, for example, a charge coupled device, a light emitting diode, a light guide, an optical camera, a photocoupler, or a waveguide. In another embodiment, the curable composition can be used in an optical instrument to help evenly illuminate the surface of the optical instrument from which light is extracted.

  In one embodiment, a highly transparent cured silicone product is formed by curing the composition. In another embodiment, the highly transparent cured silicone product is a molded article, a monolithic article, or an extruded article. In yet another embodiment, a highly transparent cured silicone product includes a substrate that forms a single article with a cured silicone layer.

  In another embodiment, the composition can be applied to the optical component by any production method, including optical components such as lenses, reflectors, sheets, films, bars, and tubing. It is not specifically limited to. The composition can be used for electronic devices, displays, soft lithography, and medical and healthcare devices. In one embodiment, the composition can be used as a light diffuser or to obtain a diffusing effect.

  The examples are intended to illustrate specific embodiments to those skilled in the art and should not be construed as limiting the scope of the present disclosure as set forth in the claims.

  Samples were prepared by the following method for mechanical and optical evaluation. The method used for each example is shown in Table 1.

Mechanical evaluation sample preparation Y
Vinyl terminated polydimethylsiloxane, vinyl functional silicone resin, Pt catalyst, hydrogen functional crosslinker, and hydrosilylation retarder are added to a conventional vessel and on a planetary mixer (Hauschild SpeedMixer DAZ 150FVZ) 3,540. Mix for 25 seconds at revolutions per minute (rpm). The light transmissive liquid was poured into an aluminum mold and then cured at 130 ° C. for 3 hours or more to form a solid sample, which promoted the crosslinking reaction by heating. During this reaction, Pt serves as a catalyst for silicon-carbon bond formation between the hydrogen functional crosslinker molecule, the vinyl functional polydimethylsiloxane, and the vinyl functional resin. The sample thickness was 2.50 mm. Mechanical properties were measured on a texture analyzer (TA. HDPlus Texture Analyzer (Texture Technologies Corp (NY, USA)) at 23 ± 1 ° C. with a dumbbell test piece (D1708 1/2 size by die). The hardness was measured on a Shore A durometer according to ASTM D2240.

Mechanical evaluation sample preparation X
Vinyl terminated polydimethylsiloxane, vinyl functional silicone resin, Pt catalyst, hydrogen functional crosslinker, and hydrosilylation retarder are added to a conventional vessel and on a planetary mixer (Hauschild SpeedMixer DAZ 150FVZ) at 3,540 rpm. Mix for 20 seconds. The light transmissive liquid was poured into an aluminum mold (1.5 mm thickness) and then pressurized at 125 ° C. for 30 minutes to form a solid sample. A solid sample was removed from the mold and post cured at 150 ° C. for 1 hour to test the mechanical properties. Measurements of mechanical properties were performed on an Instron Mechanical Tester according to ASTM D412-06A at a speed of 2 inches / minute. Hardness was measured according to ASTM D2240 on a Shore A durometer.

Mechanical evaluation sample preparation Z
Vinyl terminated polydimethylsiloxane, vinyl functional silicone resin, Pt catalyst, hydrogen functional crosslinker, and hydrosilylation retarder are added to a conventional vessel and on a planetary mixer (Hauschild SpeedMixer DAZ 150FVZ) at 3,540 rpm. Mix by asymmetric centrifugal mixing for 20 seconds. The material is then subjected to injection molding where a large amount of material is placed in a mold hole heated to 150 ° C. at a pressure of 750 pounds per square inch (psi) with a 15 second waiting time and 30 seconds. The ASTM Die C test piece is manufactured with a curing time of After removal from the mold cavity, the sample is subjected to an additional curing step at 150 ° C. for 1 hour. Mechanical property measurements were performed on an Instron Mechanical Tester according to ASTM D416-2A at a speed of 20 inches / minute. Hardness was measured according to ASTM D2240 on a Shore A durometer.

Optical evaluation sample preparation A
Vinyl terminated polydimethylsiloxane, vinyl functional silicone resin, Pt catalyst, hydrogen functional crosslinker, and hydrosilylation retarder are added to a conventional vessel and on a planetary mixer (Hauschild SpeedMixer DAZ 150FVZ) at 3,540 rpm. Mix for 20 seconds. The liquid sample was poured into a polystyrene mold and cured at 85 ° C. for 3 hours and then post-cured at 130 ° C. for 3 hours. The sample thickness was set to 2.54 cm. The optical properties of the samples were collected on a Perkin Elmer Lambda 950 spectrophotometer. The spectrophotometer was operated at a slow scan rate with a slit width of 1 nm over a wavelength range of 200 nm to 800 nm. The recorded light transmittance is without correction of surface reflection due to the difference in refractive index between air and the silicone article (so-called Fresnel reflection).

Optical evaluation sample preparation B
Vinyl terminated polydimethylsiloxane, vinyl functional silicone resin, Pt catalyst, hydrogen functional crosslinker, and hydrosilylation retarder are added to a conventional vessel and asymmetrical centrifugal mixing (Hauschild SpeedMixer DAZ 150FVZ) at 3,400 rpm for 60 seconds. Mix by. The material is then poured into polystyrene molds and cured at 65 ° C. for 14 hours. After removal from the polystyrene mold hole, the sample is subjected to an additional curing step at 150 ° C. for 1 hour. Next, the optical properties of the molded plate samples were collected with a Varian Cary 5000 spectrophotometer equipped with an integrating sphere. The spectrophotometer was operated at a moderate scan speed with a slit width of 1 nm over a wavelength range of 200 nm to 800 nm. The overall transmittance was determined by ASTM test method E1348-11.

Optical evaluation sample preparation C
Vinyl terminated polydimethylsiloxane, vinyl functional silicone resin, Pt catalyst, hydrogen functional crosslinker, and hydrosilylation retarder are added to a conventional vessel and asymmetrical centrifugal mixing (Hauschild SpeedMixer DAZ 150FVZ) at 3,400 rpm for 60 seconds. Mix by. The material is then subjected to injection molding, where a large amount of material is injected at a pressure of 750 psi into a mold hole heated to 150 ° C. with a waiting time of 15 seconds and a curing time of 30 seconds, A 0.28 cm thick plate is produced. After removal from the mold cavity, the sample is subjected to an additional curing step at 150 ° C. for 1 hour. The optical properties of the molded plate samples were collected with a Varian Cary 5000 spectrophotometer equipped with an integrating sphere. The spectrophotometer was operated at a moderate scan speed with a slit width of 1 nm over a wavelength range of 200 nm to 800 nm. The overall light transmittance and haze were determined by ASTM test method E1348-11.

Optical evaluation sample preparation D
Vinyl terminated polydimethylsiloxane, vinyl functional silicone resin, Pt catalyst, hydrogen functional crosslinker, and hydrosilylation retarder are added to a conventional vessel and asymmetrical centrifugal mixing (Hauschild SpeedMixer DAZ 150FVZ) at 3,400 rpm for 60 seconds. Mix by. The material was then poured into molds with holes (1.0 cm, 2.5 cm, 5.0 cm, and 10.0 cm long) and allowed to cure at 60 ° C. for 14 hours. The sample is removed from the mold cavity and subjected to an additional curing step at 150 ° C. for 1 hour. The optical properties of the molded plate samples were then collected with a Perkin Elmer Lambda 950 spectrophotometer. The spectrophotometer was operated at a slow scan rate with a slit width of 1 nm over a wavelength range of 200 nm to 800 nm. The recorded light transmittance is without correction of surface reflection due to the difference in refractive index between air and the silicone article (so-called Fresnel reflection).

  FIG. 1 shows the light transmittance measured for a 0.28 cm thick sample as a function of wavelength using Optical Evaluation Sample Preparation C. FIG. 2 shows the optical haze measured for a 0.28 cm thick sample using optical evaluation sample preparation C as a function of wavelength. FIG. 3 shows the light transmittance measured as a function of wavelength using the optical evaluation sample preparation D for a 1.0 cm thick sample. FIG. 4 shows the light transmittance measured for a 3.2 cm thick sample using optical evaluation sample preparation B as a function of wavelength. Each of FIGS. 1-4 shows that transmittance and haze issues are reduced or eliminated with the exemplary compositions of the present disclosure.

Mass average molecular weight evaluation The molecular weight of the alkenyl functional resin was determined by triple detection gel permeation chromatography. The chromatographic apparatus consisted of a Waters 515 pump, a Waters 717 autosampler, and a Waters 2410 differential refractometer. Separation was performed with two (300 mm × 7.5 mm) Polymer Laboratories PLgel 5 μm Mixed-C columns (molecular weight separation range 200-2,000,000, preceded by PLgel 5 μm guard column (50 mm × 7.5 mm)). Analysis was performed using HPLC grade toluene flowing at 1.0 mL / min as the eluent, and the column and detector were both controlled at 45 ° C. The sample was solvated for approximately 3 hours at room temperature with appropriate shaking, filtered through a 0.45 μm PTFE syringe filter, prepared as a 5 mg / mL toluene solution, and then analyzed. A 75 μL injection volume was used and data was collected for 25 minutes. Data collection and analysis were performed using ThermoLabsystems Atlas chromatography software and Polymer Laboratories Circus GPC software. The average molecular weight was determined against a calibration curve (third order) generated using standard polystyrene spanning the molecular weight range of 580-2300,000.

Industrial Applications The compositions of the present disclosure may be useful in the production of optical and electronic equipment, such as light guides and LED packaging. Products prepared by curing these compositions can provide one or more advantages, including improved light transmission, improved reliability, and longer LED packaging lifespan. The advantages are not particularly limited to these. Depending on the composition and method of forming the cured product, it can be of a geometric shape, including cylindrical, rectangular, single convex lens, patterned lens, textured surface, dome shape, and cap shape, The geometric shape is not particularly limited to these. In optical instrument applications, the composition can be pre-produced by molding (injection molding or transfer molding) or an integral molding process. Alternatively, the molding process of optical assembly is called “overmolding” or “insert molding” on a rigid or flexible substrate and can be performed using the compositions described herein. The composition can be molded into a cured product with relatively high tensile strength. The composition can be formulated to produce a cured product of relatively high or relatively low hardness, depending on the desired end use of the cured product. The surface of the cured product is not sticky and has elastoplastic properties. The combination of properties can make the composition suitable for overmolding and other applications. Using the light guide described above, light can be transmitted from the light source to the observation surface by internal reflection. Examples of such applications include lamps for lighting purposes such as lamps and light emitters, backlight members for displays, vehicle lights, and message board applications.

  The foregoing descriptions of embodiments and examples are presented for purposes of illustration and description. It is not intended to be exhaustive or limited to the described form. Many modifications are possible in light of the above teaching. Some of those modifications have been considered and others can be understood by those skilled in the art. Embodiments have been selected and described for illustration of various embodiments. Of course, the scope is not limited to the examples or embodiments described herein, and can be employed by those skilled in the art in any number of applications and equivalent equipment. Rather, it is intended that the scope be determined by the claims appended hereto. Further, the features of various embodiments for implementation can be combined to obtain further embodiments. The phrase “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or embodiments.

  Reference throughout this specification to “one embodiment” or “an embodiment” refers to a particular feature, structure, or characteristic described in connection with a particular embodiment, at least a subject matter of the claims It can mean that it can be included in one embodiment. Accordingly, the phrase “in one embodiment” or “an embodiment” in various places throughout this specification is not necessarily intended to refer to the same embodiment or any one particular embodiment described. Not exclusively. Furthermore, the particular features, structures, or characteristics described can be combined in various ways in one or more embodiments. Of course, in general, these and other items can vary depending on the particular use situation. Therefore, the specific situation of the description or use of these terms can provide useful guidance on the reasoning to be made about that situation.

Claims (15)

(I) having an average of at least two alkenyl groups in each molecule, having a degree of polymerization in the range of about 25 to about 10,000 and present in the range of about 20% to about 50% by weight of the organopolysiloxane. And (ii) SiO _4/2 units, R ¹ ₂ R ² SiO _1/2 units, and R ¹ ₃ SiO _1/2 units [wherein R ¹ is C _1-10 Alkyl and R ² is alkenyl. Wherein the resin contains the alkenyl in the range of about 1.0% to about 4.5% by weight, and the hydroxyl content on the silicon is about 0.2% to about 2.0% by weight. Organopolysiloxane in the form of a resin having a weight average molecular weight in the range of about 2,000 g / mol to about 22,000 g / mol,
An organopolysiloxane containing,
A crosslinking agent;
A catalytic amount of a hydrosilylation catalyst;
A curable silicone composition comprising:   An additional selected from the group consisting of retarders, mold release agents, fillers, adhesion promoters, heat stabilizers, flame retardants, reactive diluents, antioxidants, and combinations of any two or more thereof The composition of claim 1 further comprising an ingredient.   The composition of claim 2, wherein the additional component comprises a reaction retardant for hydrosilylation, and the additional component is at a concentration of about 10 ppm to about 5,000 ppm based on the total weight of the composition. object.   The hardness (Shore A) is about 60 to about 95, the tensile strength is stronger than about 3 MPa, and the overall light transmittance (measured by ASTM test method E1348-11) is a wavelength of 598 nm as a thickness of 3.2 cm. 2. The composition of claim 1, wherein the composition is greater than about 90%. The hardness (Shore A) is from about 60 to about 95, the tensile strength is greater than about 3 MPa, and the light attenuation coefficient is less than about 0.01 cm ⁻¹ measured at a wavelength of 598 nm. Composition.   A cured silicone product having high transparency, formed by curing the composition according to any one of claims 1 to 3.   The cured silicone product with high transparency according to claim 6, wherein the cured product is a molded article, an integrally molded article, or an extruded article.   8. A highly transparent cured silicone product according to claim 7, comprising a substrate that forms a single article with a cured silicone layer.   Use of the cured product according to claim 6 in optical equipment applications. A method for producing a curable silicone composition, the method comprising:
Mixing the solution, wherein the solution has (i) an average of at least two alkenyl groups in each molecule, the degree of polymerization ranges from about 25 to about 10,000, and the component (A) An alkenyl-functional dialkylpolysiloxane ranging from about 20% by weight to about 50% by weight of component (A), and (ii) SiO _4/2 units, R ¹ ₂ R ² SiO _1/2 units, and R ¹ ₃ SiO _1/2 unit wherein R ¹ is C _1-10 alkyl and R ² is alkenyl. ], Wherein the alkenyl group content is in the range of about 1.0% to about 4.5% by weight, and the hydroxyl content on the silicon is about 0.2% by weight. An alkenyl functional organopolysiloxane resin having a weight average molecular weight of about 2,000 g / mole to about 22,000 g / mole,
An organopolysiloxane containing,
A crosslinking agent;
A catalytic amount of a hydrosilylation catalyst,
A method of producing the curable silicone composition by mixing the solution.   11. The method of claim 10, further comprising adding a reaction retardant to the solution.   12. The composition of claim 11, wherein the reaction retardant retards hydrosilylation and is at a concentration of about 10 ppm to about 5,000 ppm based on the total weight of the composition.   The method of claim 10, further comprising heating the curable silicone composition to form a cured silicone product.   The heating step cures the solution by one of an injection molding method, a transfer molding method, an integral molding method, an extrusion molding method, an over molding method, a compression molding method, and a casting molding method, thereby forming a molded article. 14. The method of claim 13, further comprising: manufacturing a monolithic article or an extruded article. About 20% to about 50% by weight of the organopolysiloxane having an average of at least two alkenyl groups in each molecule and a viscosity at 25 ° C. of about 300 mPa · s to about 2,000,000 mPa · s. dialkyl polysiloxanes, and SiO _4/2 ^units, _R 1 _{² R} ² _{SiO 1/2} units, and ^R ₁ 3 _{SiO 1/2} units ^{wherein, R} _{1 2} is _{C 1-10} alkyl, ^{R 2} Is alkenyl. An alkenyl-containing resin-form organopolysiloxane having an alkenyl group content of about 1% to about 4.5% by weight and a hydroxyl content on silicon of about 0.2% by weight About 50% to about 80% by weight of the organopolysiloxane in the form of an alkenyl-containing resin in the range of about 2.0% by weight;
Containing 100 parts by weight of an alkenyl-containing organopolysiloxane,
A cross-linking agent having an average of at least three silicon-bonded hydrogen atoms in each molecule, wherein the silicon-bonded group other than the silicon-bonded hydrogen is C _1-10 alkyl, and 1 mol of the organopolysiloxane An amount that provides about 0.8 moles to about 2.0 moles of silicon-bonded hydrogen per total alkenyl;
The crosslinking agent itself is an organopolysiloxane,
Silicon-bonded hydrogen is about 0.7% by weight and SiO _4/2 units and HR ³ ₂ SiO _1/2 units [wherein RR ³ is C _1-10 alkyl. About 5% by weight of component (B) in a ratio ranging from about 1.50 moles to about 3.80 moles of HR ³ ₂ SiO _1/2 units per mole of SiO _4/2 units Of about 100% by weight organopolysiloxane, and silicon-bonded hydrogen of at least about 0.3% by weight and wherein the silicon-bonded groups other than the silicon-bonded hydrogen are C _1-10 alkyl 0% to about 50% by weight linear organopolysiloxane,
A crosslinking agent which is an organopolysiloxane containing
A catalytic amount of a hydrosilylation reaction catalyst;
A curable silicone composition comprising:

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