Non-oil self-lubricating silicones and methods of producing the same

Abstract

Compositions disclosed herein comprise a silicone rubber base composition comprising a vinyl silicone, a crosslinker comprising a hybrid hydride silicone having an average silicon hydride (Si-H) content of at least 1 mmol / g, an inhibitor, a transition metal catalyst complex, from about 0.2 wt.% to about 2 wt.%, based on a total weight of the composition, of a fatty acid amide-based slip agent, and from about 0.2 wt.% to about 5 wt.%, based on the total weight of the composition, of a synergistic additive. Masterbatches for the preparation of the compositions, and post-cured silicone products formed from the compositions are also provided.

Description

NON-OIL SELF-LUBRICATING SILICONES AND METHODS OF PRODUCING THESAMECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and all benefit of U.S. Provisional Patent Application No. 63 / 672,193, filed on July 16, 2024, the entire disclosure of which is fully incorporated herein by reference.FIELD

[0002] The present disclosure relates to polymeric compositions and, more particularly, to polymeric compositions including self-lubricating silicone-based compositions.BACKGROUND

[0003] Silicone tubing is widely used in healthcare applications due to its biocompatibility, chemical resistance, optical transparency, and good mechanical performance over a wide range of temperatures. However, conventional silicone-based articles exhibit a tacky surface and static charge that can easily attract dust and other debris. For example, as a patient moves about a facility, silicone tubing (e.g., IV tubing) may drag on the floor and pick up dirt and dust. Manufacturers have previously attempted to reduce the tackiness of the silicone-based articles by applying a coating. However, such coatings typically only work for a short period of time before wearing away and losing performance.

[0004] Moreover, conventional silicone-based articles may also exhibit blocking (e.g., sticking to itself) as a result of the tackiness. Although lubricious coatings or oils have been used to address this issue, there remains the issue of the wear of the coating and loss of performance over time. In addition, conventional slip agents tend to migrate very quickly, particularly upon curing of the silicone-based composition.

[0005] Accordingly, there remains a need for alternative silicone-based compositions that exhibit reduced tack.SUMMARY

[0006] The following is a brief summary of subj ect matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims.

[0007] According to a first aspect of the present disclosure, a composition comprises a silicone rubber base composition comprising a vinyl silicone, a crosslinker comprising a hybrid hydride silicone having an average silicon hydride (Si-H) content of at least 1 mmol / g, an inhibitor, a transition metal catalyst complex, from about 0.2 wt.% to about 2 wt.%, based on a total weight of the composition, of a fatty acid amide-based slip agent, and from about 0.2 wt.% to about 5 wt.%, based on the total weight of the composition, of a synergistic additive. The fatty acid amide- based slip agent is selected from the group consisting of a primary unsaturated fatty acid amide, a primary saturated and branched fatty acid amide, a secondary saturated fatty acid amide, and combinations thereof. The synergistic additive is selected from the group consisting of an epoxycontaining silane, an epoxy-containing siloxane copolymer, a silicone polymer containing a polyethylene oxide segment, and combinations thereof.

[0008] In a second aspect, a composition comprises the composition of the first aspect, wherein the fatty acid amide-based slip agent comprises a primary unsaturated fatty acid amide.

[0009] In a third aspect, a composition comprises the composition of any preceding aspect, wherein the epoxy-containing silane in the synergistic additive is an epoxy-containing trialkoxysilane.

[0010] In a fourth aspect, a composition comprises the composition of any preceding aspect, wherein the fatty acid amide-based slip agent comprises erucamide.

[0011] In a fifth aspect, a composition comprises the composition of any preceding aspect, wherein the silicone rubber base composition further comprises a silicone resin selected from the group consisting of a methyl silicone, an -OH silicone, a phenyl silicone, a fluorosilicone, and combinations thereof.

[0012] In a sixth aspect, a composition comprises the composition of any preceding aspect, wherein the silicone rubber base further comprises a silica and a silicone plasticizer.

[0013] In a seventh aspect, a composition comprises the composition of the sixth aspect, wherein the silicone plasticizer comprises polydimethyl siloxane (PDMS).

[0014] In an eighth aspect, a composition comprises the composition of any preceding aspect, wherein the inhibitor comprises ethynyl cyclohexanol.

[0015] In a ninth aspect, a composition comprises the composition of any preceding aspect, further comprising one or more additives selected from the group consisting of colorants, carbonblacks, anti-static agents, anti-dust agents, mineral fillers, heat stabilizers, acid acceptors, adhesion promoters, tackifiers, mold releases, flame retardants, silicas, silicates, green strength additives, tensile modifiers, scavengers, antimicrobial additives, and combinations thereof.

[0016] In a tenth aspect, a composition comprises the composition of any preceding aspect, wherein a molar ratio between a total number of moles of epoxy groups and ethylene oxide unit (- CH2-CH2-O-) groups present in the synergistic additive and a total number of moles of amide groups present in the fatty acid amide-based slip agent is from about 1 : 1 to about 3: 1.

[0017] In an eleventh aspect, a post-cured silicone product is formed from the composition according to any preceding aspect.

[0018] In a twelfth aspect, a post-cured silicone product comprises the post-cured silicone product of the eleventh aspect, wherein the post-cured silicone product has an average dynamic coefficient of friction of less than 1 when measured on a dry, smooth stainless steel surface.

[0019] In a thirteenth aspect, a post-cured silicone product of the eleventh or twelfth aspect, wherein the post-cured silicone product has an average dynamic coefficient of friction of less than 0.6 when measured on a dry, smooth stainless steel surface.

[0020] In a fourteenth aspect, a post-cured silicone product comprises the post-cured silicone product of the eleventh or twelfth aspects, wherein the post-cured silicone product has a relative dynamic coefficient of friction of less than 50% as compared to a post-cured silicone product formed from a composition not including the fatty acid amide-based slip agent and the synergistic additive but is otherwise identical.

[0021] In a fifteenth aspect, a post-cured silicone product comprises the post-cured silicone product of any one of the eleventh through thirteenth aspects, wherein the post-cured silicone product has an instantaneous Shore A hardness of greater than 30 when measured in accordance with ASTM D2240.

[0022] In a sixteenth aspect, a post-cured silicone product comprises the post-cured silicone product of any one of the eleventh through fourteenth aspects, wherein the post-cured silicone product has a transmission of greater than 60% when measured in accordance with ASTM D1003.

[0023] In a seventeenth aspect, a post-cured silicone product comprises the post-cured silicone product of any one of the eleventh through fifteenth aspects, wherein the post-cured silicone product has a haze of less than 110% when measured in accordance with ASTM DI 003.

[0024] According to an eighteenth aspect, a masterbatch comprises a silicone carrier, a fatty acid amide-based slip agent, a synergistic additive, and, optionally, a filler. The fatty acid amide-based slip agent is selected from the group consisting of a primary unsaturated fatty acid amide, a primary saturated and branched fatty acid amide, and combinations thereof. The synergistic additive is selected from the group consisting of an epoxy-containing silane, an epoxycontaining siloxane copolymer, and a silicone polymer containing a polyethylene oxide segment.

[0025] In eighteenth nineteenth aspect, a masterbatch comprises the masterbatch of the seventeenth aspect, wherein the fatty acid amide-based slip agent comprises a primary unsaturated fatty acid amide.

[0026] In a twentieth aspect, a masterbatch comprises the masterbatch of the eighteenth aspect, wherein the fatty acid amide-based slip agent comprises erucamide.

[0027] In a twenty-first aspect, a masterbatch comprises the masterbatch of the seventeenth aspect, wherein the fatty acid amide-based slip agent comprises a primary saturated and branched fatty acid amide.

[0028] In a twenty-second aspect, a masterbatch comprises the masterbatch of the twentieth aspect, wherein the fatty acid amide-based slip agent comprises isostearic amide.

[0029] In a twenty-third aspect, a masterbatch comprises the masterbatch of any of the seventeenth through twenty -first aspects, wherein the filler comprises a silica, a silicate, a hydrate, a carbonate, a carbon black, treated versions thereof, or combinations thereof.

[0030] In a twenty-fourth aspect, a masterbatch comprises the masterbatch of any of the seventeenth through twenty-second aspects, wherein a molar ratio between a total number of moles of epoxy groups and ethylene oxide unit (-CH2-CH2-O-) groups present in the synergistic additive and a total number of moles of amide groups present in the fatty acid amide-based slip agent is from about 1 : 1 to about 3: 1.

[0031] The above summary presents a simplified summary in order to provide a basic understanding of some aspects of the systems and / or methods discussed herein. This summary is not an extensive overview of the systems and / or methods discussed herein. It is not intended toidentify key / critical elements or to delineate the scope of such systems and / or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.DETAILED DESCRIPTION

[0032] Disclosed herein are self-lubricating silicone compositions including a silicone rubber base composition, a transition metal catalyst system, a fatty acid amide-based slip agent, and a synergistic additive. The silicone rubber base composition includes at least one vinyl silicone. The transition metal catalyst system generally includes a transition metal catalyst complex, a crosslinker, and an inhibitor. The fatty acid amide-based slip agent is an unsaturated fatty acid amide, a saturated and branched fatty acid amide, or a combination of an unsaturated fatty acid amide and a saturated and branched fatty acid amide. The synergistic additive is selected from the group consisting of an epoxy-containing silane, an epoxy-containing siloxane copolymer, and a silicone polymer containing a polyethylene oxide segment. The synergistic additive can serve as an anchor for the fatty acid amide-based slip agent, thereby enabling the composition to retain the fatty acid amide-based slip agent upon curing. Other advantages are possible and contemplated and may be realized based on the following disclosure.

[0033] The terminology as set forth herein is for description of the various aspects only and should not be construed as limiting the disclosure as a whole. All references to singular characteristics or limitations of the present disclosure shall include the corresponding plural characteristic or limitation, and vice versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made. Unless specified otherwise, “a,” “an,” “the,” and “at least one” are used interchangeably. Furthermore, as used in the description and the appended claims, the singular forms “a,” “an,” and “the” are inclusive of their plural forms, unless the context clearly indicates otherwise.

[0034] Unless otherwise expressly defined, all technical and scientific terms used herein have the same meaning as commonly understood by a person of ordinary skill in the art.

[0035] Unless otherwise expressly stated, it not intended that any method disclosed herein be construed as requiring that its steps be performed in a specific order, nor that any article set forth herein be construed as requiring specific orders or orientations to its individual components.

[0036] To the extent that the term “includes” or “including” is used in the description or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that termis interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use.

[0037] Any composition described in the present disclosure can comprise, consist of, or consist essentially of the essential elements of the disclosure as described herein, as well as any additional or optional element described herein, or which is otherwise useful in polymeric compositions.

[0038] All percentages, parts, and ratios as used herein are by weight of the total blend on an “dry” basis, i.e., without solvents, unless otherwise specified.

[0039] All ranges and parameters, including but not limited to percentages, parts, and ratios, disclosed herein are understood to encompass any and all sub-ranges assumed and subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all sub-ranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less (e.g., 1 to 6.1, or 2.3 to 9.4), and to each integer (1, 2, 3, 4, 5, 6, 7, 8, 9, and 10) contained within the range. Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiments includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0040] The term “wt.%,” as described herein, refers to the weight fraction of the individual component based on a total weight of the polymeric composition, unless otherwise noted.

[0041] Additionally, as used herein, the term “exemplary” is intended to mean serving as an illustration or example of something, and is not intended to indicate a preference.

[0042] As used herein, the term “thermoset” refers to a polymer that is irreversibly hardened through a curing process.

[0043] In various aspects provided herein, a composition is disclosed that includes a silicone rubber base composition, a transition metal catalyst system, a fatty acid amide-based slipagent, and a synergistic additive. The synergistic additive can serve as an anchor for the fatty acid amide-based slip agent, thereby enabling the composition to retain the fatty acid amide-based slip agent upon curing. The post-cured silicone composition product may exhibit an average static coefficient of friction of less than 1. Also disclosed is a masterbatch comprising the fatty acid amide-based slip agent, the synergistic additive, and optionally, a filler in a silicone carrier. The masterbatch may be used to prepare the silicone compositions described herein. Products made through curing of the composition may have reduced surface tack without the use of a coating or oil. Other advantages may be realized, depending on the particular aspects, which will now be described in greater detail.Silicone Rubber Base Composition

[0044] As set forth above, the self-lubricating silicone composition can comprise a silicone rubber base composition. The silicone rubber base composition can be a high-consistency silicone rubber, also known as solid silicone rubber, a liquid silicone rubber (LSR) base composition, or a paste silicone rubber base composition. In general, the silicone rubber base composition is cured at elevated temperatures with either organic peroxides through a free-radical based curing process or a transition metal catalyst through a hydrosilylation process. In various aspects, the silicone rubber base composition comprises at least one vinyl silicone. The silicone rubber base composition may, in aspects, also include at least one silicone plasticizer and silica.

[0045] The silicone may further comprise another silicone component in addition to the vinyl silicone that is selected from the group consisting of a methyl silicone, an -OH silicone, a phenyl silicone, a fluorosilicone, and combinations thereof. The silicone may be in the form of a silicone gum or silicone fluid. In aspects of the disclosure, the total amount of silicone (including the vinyl silicone and other, optional silicones, but excluding the silica and plasticizer components) is included in the silicone rubber base composition in an amount of from about 10 wt.% to about 90 wt.%, based on a total weight of the composition. For example, the silicone rubber base composition may include from about 10 wt.% to about 90 wt.%, from about 10 wt.% to about 80 wt.%, from about 10 wt.% to about 70 wt.%, from about 10 wt.% to about 60 wt.%, from about 10 wt.% to about 50 wt.%, from about 20 wt.% to about 90 wt.%, from about 20 wt.% to about 80 wt.%, from about 20 wt.% to about 70 wt.%, from about 20 wt.% to about 60 wt.%, from about 20 wt.% to about 50 wt.%, from about 30 wt.% to about 90 wt.%, from about 30 wt.% to about 80 wt.%, from about 30 wt.% to about 70 wt.%, from about 30 wt.% to about 60 wt.%, from about 30 wt.% to about 50 wt.%, from about 40 wt.% to about 90 wt.%, from about 40 wt.% to about 80 wt.%, from about 40 wt.% to about 70 wt.%, or from about 40 wt.% to about 60 wt.%, from about40 wt.% to about 50 wt.% silicone, based on a total weight of the composition, including any and all ranges and subranges therein.

[0046] Silica may be included in the silicone rubber base composition in an amount of from about 2 wt.% to about 80 wt.%, based on a total weight of the composition. For example, the silicone rubber base composition may include from about 2 wt.% to about 80 wt.%, from about 2 wt.% to about 70 wt.%, from about 2 wt.% to about 60 wt.%, from about 2 wt.% to about 50 wt.%, from about 2 wt.% to about 40 wt.%, from about 2 wt.% to about 30 wt.%, from about 2 wt.% to about 20 wt.%, from about 5 wt.% to about 80 wt.%, from about 5 wt.% to about 70 wt.%, from about 5 wt.% to about 60 wt.%, from about 5 wt.% to about 50 wt.%, from about 5 wt.% to about 40 wt.%, from about 5 wt.% to about 30 wt.%, from about 5 wt.% to about 20 wt.%, from about 10 wt.% to about 80 wt.%, from about 10 wt.% to about 70 wt.%, from about 10 wt.% to about 60 wt.%, from about 10 wt.% to about 50 wt.%, from about 10 wt.% to about 40 wt.%, from about 10 wt.% to about 30 wt.%, from about 10 wt.% to about 20 wt.%, from about 15 wt.% to about 80 wt.%, from about 15 wt.% to about 70 wt.%, from about 15 wt.% to about 60 wt.%, from about 15 wt.% to about 50 wt.%, from about 15 wt.% to about 40 wt.%, from about 15 wt.% to about 30 wt.%, from about 15 wt.% to about 20 wt.%, from about 20 wt.% to about 80 wt.%, from about 20 wt.% to about 70 wt.%, from about 20 wt.% to about 60 wt.%, from about 20 wt.% to about 50 wt.%, from about 20 wt.% to about 40 wt.%, or from about 20 wt.% to about 30 wt.%, of the silica, based on a total weight of the composition, including any and all ranges and subranges therein. However, it should be understood that, in some aspects, the silicone rubber base composition may not include silica.

[0047] In any of the aspects described herein, the silicone plasticizer may comprise a mono- or poly-siloxane containing methyl, vinyl, hydroxyl, or phenyl groups, or a combination thereof. In aspects, the silicone plasticizer has a molecular weight of from about 0.1 g / mol to about 300,000 g / mol. For example, the silicone plasticizer may have a molecular weight of from about 0.1 g / mol to about 300,000 g / mol, from about 0.1 g / mol to about 250,000 g / mol, from about 0.1 g / mol to about 200,000 g / mol, from about 0.1 g / mol to about 150,000 g / mol, from about 0.1 g / mol to about 100,000 g / mol, from about 0.1 g / mol to about 50,000 g / mol, from about 1 g / mol to about 300,000 g / mol, from about 1 g / mol to about 250,000 g / mol, from about 1 g / mol to about 200,000 g / mol, from about 1 g / mol to about 150,000 g / mol, from about 1 g / mol to about 100,000 g / mol, from about 1 g / mol to about 50,000 g / mol, from about 10 g / mol to about 300,000 g / mol, from about 10 g / mol to about 250,000 g / mol, from about 10 g / mol to about 200,000 g / mol, from about 10 g / mol to about 150,000 g / mol, from about 10 g / mol to about 100,000 g / mol, from about 10g / mol to about 50,000 g / mol, from about 100 g / mol to about 300,000 g / mol, from about 100 g / mol to about 250,000 g / mol, from about 100 g / mol to about 200,000 g / mol, from about 100 g / mol to about 150,000 g / mol, from about 100 g / mol to about 100,000 g / mol, from about 100 g / mol to about 50,000 g / mol, from about 1,000 g / mol to about 300,000 g / mol, from about 1,000 g / mol to about 250,000 g / mol, from about 1,000 g / mol to about 200,000 g / mol, from about 1,000 g / mol to about 150,000 g / mol, from about 1,000 g / mol to about 100,000 g / mol, from about 1,000 g / mol to about 50,000 g / mol, from about 10,000 g / mol to about 300,000 g / mol, from about 10,000 g / mol to about 250,000 g / mol, from about 10,000 g / mol to about 200,000 g / mol, from about 10,000 g / mol to about 150,000 g / mol, from about 10,000 g / mol to about 100,000 g / mol, or from about 10,000 g / mol to about 50,000 g / mol, including any and all ranges and subranges therein.

[0048] In any of the aspects described herein, the silicone plasticizer may comprise polydimethylsiloxane (PDMS).

[0049] In aspects of the disclosure, the silicone plasticizer is included in the silicone rubber base composition in an amount of from about 0.1 wt.% to about 20 wt.%, based on a total weight of the composition. For example, the silicone plasticizer may be included in the silicone rubber base composition in an amount of from about 0.1 wt.% to about 20 wt.%, from about 0.1 wt.% to about 15 wt.%, from about 0.1 wt.% to about 10 wt.%, from about 0.1 wt.% to about 7.5 wt.%, from about 0.1 wt.% to about 5 wt.%, from about 0.1 wt.% to about 2 wt.%, from about 0.5 wt.% to about 20 wt.%, from about 0.5 wt.% to about 15 wt.%, from about 0.5 wt.% to about 10 wt.%, from about 0.5 wt.% to about 7.5 wt.%, from about 0.5 wt.% to about 5 wt.%, from about 0.5 wt.% to about 2 wt.%, from about 1 wt.% to about 20 wt.%, from about 1 wt.% to about 15 wt.%, from about 1 wt.% to about 10 wt.%, from about 1 wt.% to about 7.5 wt.%, from about 1 wt.% to about 5 wt.%, from about 1 wt.% to about 2 wt.%, from about 2 wt.% to about 20 wt.%, from about 2 wt.% to about 15 wt.%, from about 2 wt.% to about 10 wt.%, from about 2 wt.% to about 7.5 wt.%, from about 2 wt.% to about 5 wt.%, from about 5 wt.% to about 20 wt.%, from about 5 wt.% to about 15 wt.%, from about 5 wt.% to about 10 wt.%, or from about 5 wt.% to about 7.5 wt.%, based on a total weight of the composition, including any and all ranges and subranges therein. However, it should be understood that, in some aspects, the silicone rubber base composition may not include silicone plasticizer.Transition Metal Catalyst System

[0050] In aspects, the self-lubricating silicone composition may include a transition metal catalyst system effective to cure the silicone rubber base composition. The transition metal catalystsystem may comprise a nickel, platinum, rhodium, palladium, or other suitable transition metal. Transition metal catalyst systems are particularly well-suited for compositions intended for use in healthcare applications due to the fact that, unlike peroxide-catalyzed systems, transition metal catalysts systems do not produce harmful or undesirable by-products and the resulting product may exhibit less shrinkage. In general, the transition metal catalyst system includes a transition metal catalyst complex, a crosslinker, and an inhibitor.

[0051] The transition metal catalyst complex may be selected from the group of organo metal compounds, salts, or metals, having the ability to catalyze hydrosilylation. The metal may be selected from the group consisting of nickel, iridium, rhodium, ruthenium, osmium, palladium, and platinum compounds. In aspects, the transition metal catalyst complex can be a complex of any form of nickel, iridum, rhodium, or platinum. In aspects including a platinum catalyst, the catalyst complex can be any form of platinum (0), (II), or (IV) compounds. For example, the transition metal catalyst may be a Pt-alkenyl complex, such as alkenyl, cycloalkenyl, alkenylsiloxane, or the like. Particular transition metal catalyst complexes that may be used are those conventionally known and used in the art.

[0052] The amount of transition metal catalyst complex included in the self-lubricating silicone composition is not particularly limited, so long as there is a sufficient amount to accelerate the hydrosilylation at the desired temperature and within the desired temperature in the presence of the other ingredients of the composition. The amount of transition metal catalyst complex included will also depend on the particular catalyst complex and the amount of inhibiting compounds. In general, the transition metal catalyst complex may be included in the selflubricating silicone composition in an amount of from 0.001 wt.% to about 7 wt.%, based on a total weight of the composition. For example, the composition may include the transition metal catalyst complex in an amount of from about 0.001 wt.% to about 7 wt.%, from about 0.001 wt.% to about 5 wt.%, from about 0.001 wt.% to about 2 wt.%, from about 0.001 wt.% to about 1 wt.%, from about 0.001 wt.% to about 0.5 wt.%, from about 0.01 wt.% to about 7 wt.%, from about 0.01 wt.% to about 5 wt.%, from about 0.01 wt.% to about 2 wt.%, from about 0.01 wt.% to about 1 wt.%, from about 0.01 wt.% to about 0.5 wt.%, from about 0.1 wt.% to about 7 wt.%, from about 0.1 wt.% to about 5 wt.%, from about 0.1 wt.% to about 2 wt.%, from about 0.1 wt.% to about 1 wt.%, from about 0.1 wt.% to about 0.5 wt.%, from about 1 wt.% to about 7 wt.%, from about 1 wt.% to about 5 wt.%, or from about 1 wt.% to about 2 wt.%, based on the total weight of the composition, including any and all ranges and subranges therein.

[0053] In general, platinum catalyst complexes suitable for use in any of the aspects herein include a neat platinum catalyst in an inert liquid carrier. In aspects, the platinum catalyst complex includes metal platinum in an amount of from about 0.1 wt.% to about 10 wt.%, based on a total weight of the platinum catalyst complex. For example, the platinum catalyst complex may include metal platinum in an amount of from about 0.1 wt.% to about 10 wt.%, from about 0.1 wt.% to about 8 wt.%, from about 0.1 wt.% to about 6 wt.%, from about 0.1 wt.% to about 4 wt.%, from about 0.1 wt.% to about 2 wt.%, from about 0.5 wt.% to about 10 wt.%, from about 0.5 wt.% to about 8 wt.%, from about 0.5 wt.% to about 6 wt.%, from about 0.5 wt.% to about 4 wt.%, from about 0.5 wt.% to about 2 wt.%, from about 1 wt.% to about 10 wt.%, from about 1 wt.% to about 8 wt.%, from about 1 wt.% to about 6 wt.%, from about 1 wt.% to about 4 wt.%, from about 1 wt.% to about 2 wt.%, from about 1.5 wt.% to about 10 wt.%, from about 1.5 wt.% to about 8 wt.%, from about 1.5 wt.% to about 6 wt.%, from about 1.5 wt.% to about 4 wt.%, or from about 1.5 wt.% to about 2 wt.%, based on a total weight of the platinum catalyst complex, including any and all ranges and subranges therein.

[0054] The crosslinker included in the platinum catalyst system of may be selected from the group consisting of a hybrid hydride silicone, a pendant-only hydride silicone, and combinations thereof. As used herein, a “hybrid hydride silicone” refers to a hydride silicone with Si-H groups present at both a terminal location and at least one pendant location on the silicone chain. As used herein, a “pendant-only hydride silicone” refers to a hydride silicone with Si-H groups present only at one or more pendant locations on the silicone chain. The crosslinker may comprise, for example, methylhydrogen siloxane-dimethyl siloxane copolymer with methyl terminal groups (a pendant-only hydride silicone) or a hydride-terminated methylhydrogen siloxane-dimethyl siloxane copolymer (a hybrid hydride silicone). A variety of suitable crosslinkers are available and known to those skilled in the art, including, for example, ANDISIL® XL-1342 (a hybrid hydride silicone available from AB Specialty Silicones) and DOWSIL™ 6- 3570 (a pendant-only hydride silicone available from The Dow Chemical Company).

[0055] In aspects, the crosslinker has an average Si-H content of at least 1 mmol / g. For example, the crosslinker may have an average Si-H content of from 1 mmol / g to 15 mmol / g, from 1 mmol / g to 12 mmol / g, from 1 mmol / g to 10 mmol / g, from 2 mmol / g to 15 mmol / g, from 2 mmol / g to 12 mmol / g, from 2 mmol / g to 10 mmol / g, from 3 mmol / g to 15 mmol / g, from 3 mmol / g to 12 mmol / g, or from 3 mmol / g to 10 mmol / g. In certain aspects, the crosslinker has an average Si-H content of from 3 mmol / g to 10 mmol / g, which may provide an Si-H content effective to provide improved efficiency in the curing process. In some aspects, the crosslinker is a hybridhydride silicone that contributes greater than about 50 mol% of the total amount of Si-H groups in the composition.

[0056] In aspects of the disclosure, the crosslinker is included in the self-lubricating silicone composition in an amount of from about 0.1 wt.% to about 8 wt.%, based on a total weight of the composition. For example, the self-lubricating silicone composition may include from about 0.1 wt.% to about 8 wt.%, from about 0.1 wt.% to about 6 wt.%, from about 0.1 wt.% to about 4 wt.%, from about 0.1 wt.% to about 2 wt.%, from about 0.5 wt.% to about 8 wt.%, from about 0.5 wt.% to about 6 wt.%, from about 0.5 wt.% to about 4 wt.%, from about 0.5 wt.% to about 2 wt.%, from about 1 wt.% to about 8 wt.%, from about 1 wt.% to about 6 wt.%, from about 1 wt.% to about 4 wt.%, from about 1 wt.% to about 2 wt.%, from about 1.5 wt.% to about 8 wt.%, from about 1.5 wt.% to about 6 wt.%, from about 1.5 wt.% to about 4 wt.%, or from about 1.5 wt.% to about 2 wt.% of the crosslinker, based on a total weight of the composition, including any and all ranges and subranges therein. It is also contemplated that the crosslinker may be included in the composition in an amount greater than 8 wt.% in some aspects in order to provide a sufficient silicone hydride (Si-H) content to the composition.

[0057] In aspects, the crosslinker may be included in an amount to provide an Si-H group content of from about 0.1 wt.% to about 10 wt.%, based on a total weight of the self-lubricating silicone composition. For example, the crosslinker may be included in the composition in an amount to provide an Si-H group content of from about 0.1 wt.% to about 10 wt.%, from about 0.1 wt.% to about 8 wt.%, from about 0.1 wt.% to about 6 wt.%, from about 0.1 wt.% to about 4 wt.%, from about 0.1 wt.% to about 2 wt.%, from about 0.5 wt.% to about 10 wt.%, from about 0.5 wt.% to about 8 wt.%, from about 0.5 wt.% to about 6 wt.%, from about 0.5 wt.% to about 4 wt.%, from about 0.5 wt.% to about 2 wt.%, from about 1 wt.% to about 10 wt.%, from about 1 wt.% to about 8 wt.%, from about 1 wt.% to about 6 wt.%, from about 1 wt.% to about 4 wt.%, from about 1 wt.% to about 2 wt.%, from about 1.5 wt.% to about 10 wt.%, from about 1.5 wt.% to about 8 wt.%, from about 1.5 wt.% to about 6 wt.%, from about 1.5 wt.% to about 4 wt.%, or from about 1.5 wt.% to about 2 wt.%, based on a total weight of the composition, including any and all ranges and subranges therein.

[0058] In any of the aspects disclosed herein, the inhibitor may comprise ethynyl cyclohexanol, dimethyl fumarate, dimethyl maleate, or an acetylenic alcohol.

[0059] In aspects, the inhibitor is included in the self-lubricating silicone composition in an amount of from about 0.001 wt.% to about 3 wt.%. For example, the inhibitor may be includedin the self-lubricating silicone composition in an amount of from about 0.001 wt.% to about 3 wt.%, from about 0.001 wt.% to about 2 wt.%, from about 0.001 wt.% to about 1 wt.%, from about 0.001 wt.% to about 0.5 wt.%, from about 0.01 wt.% to about 3 wt.%, from about 0.01 wt.% to about 2 wt.%, from about 0.01 wt.% to about 1 wt.%, from about 0.01 wt.% to about 0.5 wt.%, from about 0.1 wt.% to about 3 wt.%, from about 0.1 wt.% to about 2 wt.%, from about 0.1 wt.% to about 1 wt.%, from about 0.1 wt.% to about 0.5 wt.%, from about 1 wt.% to about 3 wt.%, or from about 1 wt.% to about 2 wt.%, based on the total weight of the composition, including any and all ranges and subranges therein.Fatty Acid Amide-Based Slip Agent

[0060] As described above, the composition further includes at least one fatty acid amide- based slip agent. In general, a fatty acid amide has the following structure:where R is a C3-C27 alkyl moiety. R can be saturated, mono-unsaturated, or poly-unsaturated, and may be linear or branched. The fatty acid amide may be, for example, a primary unsaturated fatty acid amide, a primary saturated and branched fatty acid amide, a secondary saturated fatty acid amide, or a combination thereof. The composition may include a single fatty acid amide-based slip agent, or a blend of at least two different fatty acid amide-based slip agents. In aspects, the fatty acid amide comprises a primary unsaturated fatty acid amide with a C=C double bond in the R group. The C=C double bond may be a cis bond or a trans bond. The primary unsaturated fatty acid may be selected from erucamide, oleamide, elaidamide, linoleamide, and combinations thereof. Suitable fatty acid amide-based slip agents may also comprise a saturated and branched fatty amide such as isostearic amide, or a secondary fatty amide such as ethylene bis steramide.

[0061] In aspects of the disclosure, the fatty acid amide-based slip agent is included in the self-lubricating silicone composition in an amount of from about 0.1 wt.% to about 2.0 wt.%, based on a total weight of the composition. For example, the fatty acid amide-based slip agent may be present in the composition in an amount of from about 0.1 wt.% to about 2.0 wt.%, from about 0.3 wt.% to about 2.0 wt.%, from about 0.5 wt.% to about 2.0 wt.%, from about 0.7 wt.% to about 2.0 wt.%, from about 1.0 wt.% to about 2.0 wt.%, from about 1.3 wt.% to about 2.0 wt.%, from about1.5 wt.% to about 2.0 wt.%, from about 0.1 wt.% to about 1.7 wt.%, from about 0.3 wt.% to about1.7 wt.%, from about 0.5 wt.% to about 1.7 wt.%, from about 0.7 wt.% to about 1.7 wt.%, from about 1.0 wt.% to about 1.7 wt.%, from about 1.3 wt.% to about 1.7 wt.%, from about 0.1 wt.% to about 1.5 wt.%, from about 0.3 wt.% to about 1.5 wt.%, from about 0.5 wt.% to about 1.5 wt.%, from about 0.7 wt.% to about 1.5 wt.%, from about 1.0 wt.% to about 1.5 wt.%, from about 1.3 wt.% to about 1.5 wt.%, from about 0.1 wt.% to about 1.3 wt.%, from about 0.3 wt.% to about 1.3 wt.%, from about 0.5 wt.% to about 1.3 wt.%, from about 0.7 wt.% to about 1.3 wt.%, from about 1.0 wt.% to about 1.3 wt.%, from about 0.1 wt.% to about 1.0 wt.%, from about 0.3 wt.% to about 1.0 wt.%, from about 0.5 wt.% to about 1.0 wt.%, or from about 0.7 wt.% to about 1.0 wt.%, based on a total weight of the composition, including any and all ranges and subranges therein.Synergistic Additive

[0062] In any of the aspects described herein, the self-lubricating silicone composition may include a synergistic additive. Without being bound by theory, it is believed that there is a molecular interaction between the synergistic additive and the fatty acid amide through a hydrogenbonding mechanism or a chemical reaction. The hydrogen-bonding mechanism may occur between the hydrogen-acceptor group (e.g., an epoxy group) of the synergistic additive and a hydrogen of the -NH2 end group of the fatty acid amide. The hydrosilylation reaction may also occur between the C=C double bond of an unsaturated fatty acid amide and the Si-H group of the hydride silicone crosslinker in the presence of a transition metal catalyst at a slower reaction rate than that of the hydrosilylation between the vinyl groups of the vinyl silicone component and the crosslinker. Such interactions may still anchor the fatty acid amide-based slip agent to the surface of the silicone rubber composition if the interactive species are both available at the surface, thereby enabling the composition to retain the slip agent following curing or a post-curing step of the silicone rubber. The synergistic additive may comprise an epoxy-containing silane, an epoxy-containing siloxane copolymer, a silicone polymer containing a polyethylene oxide segment, or combinations thereof. Example synergistic additives include, by way of example and not limitation, polyether modified siloxane, polyether-modified polydimethylsiloxane, glycidoxypropyltrimethoxysilane, and combinations thereof. Commercially available synergistic additives include those marketed under the tradenames XIAMETER™, including XIAMETER™ OFS-6040 and XIAMETER™ OFS- 6106 (available from The Dow Chemical Company), Z-6040 and Z-6106 (available from The Dow Chemical Company), and BYK®, including BYK®-333 and BYK®-345 (available from BYK), for example.

[0063] The synergistic additive may be included in the self-lubricating silicone composition in an amount of from about 0.2 wt.% to about 5.0 wt.%, based on a total weight of thecomposition. For example, the synergistic additive may be included in the composition in an amount of from about 0.2 wt.% to about 5.0 wt.%, from about 0.3 wt.% to about 5.0 wt.%, from about 0.5 wt.% to about 5.0 wt.%, from about 0.8 wt.% to about 5.0 wt.%, from about 1.0 wt.% to about 5.0 wt.%, from about 1.5 wt.% to about 5.0 wt.%, from about 2.0 wt.% to about 5.0 wt.%, from about 2.5 wt.% to about 5.0 wt.%, from about 3.0 wt.% to about 5.0 wt.%, from about 3.5 wt.% to about 5.0 wt.%, from about 0.2 wt.% to about 4.5 wt.%, from about 0.3 wt.% to about 4.5 wt.%, from about 0.5 wt.% to about 4.5 wt.%, from about 0.8 wt.% to about 4.5 wt.%, from about 1.0 wt.% to about 4.5 wt.%, from about 1.5 wt.% to about 4.5 wt.%, from about 2.0 wt.% to about4.5 wt.%, from about 2.5 wt.% to about 4.5 wt.%, from about 3.0 wt.% to about 4.5 wt.%, from about 3.5 wt.% to about 4.5 wt.%, from about 0.2 wt.% to about 4.0 wt.%, from about 0.3 wt.% to about 4.0 wt.%, from about 0.5 wt.% to about 4.0 wt.%, from about 0.8 wt.% to about 4.0 wt.%, from about 1.0 wt.% to about 4.0 wt.%, from about 1.5 wt.% to about 4.0 wt.%, from about 2.0 wt.% to about 4.0 wt.%, from about 2.5 wt.% to about 4.0 wt.%, from about 3.0 wt.% to about 4.0 wt.%, from about 3.5 wt.% to about 4.0 wt.%, from about 0.2 wt.% to about 3.5 wt.%, from about 0.3 wt.% to about 3.5 wt.%, from about 0.5 wt.% to about 3.5 wt.%, from about 0.8 wt.% to about3.5 wt.%, from about 1.0 wt.% to about 3.5 wt.%, from about 1.5 wt.% to about 3.5 wt.%, from about 2.0 wt.% to about 3.5 wt.%, from about 2.5 wt.% to about 3.5 wt.%, from about 3.0 wt.% to about 3.5 wt.%, from about 0.2 wt.% to about 3.0 wt.%, from about 0.3 wt.% to about 3.0 wt.%, from about 0.5 wt.% to about 3.0 wt.%, from about 0.8 wt.% to about 3.0 wt.%, from about 1.0 wt.% to about 3.0 wt.%, from about 1.5 wt.% to about 3.0 wt.%, from about 2.0 wt.% to about 3.0 wt.%, from about 2.5 wt.% to about 3.0 wt.%, from about 0.2 wt.% to about 2.5 wt.%, from about 0.3 wt.% to about 2.5 wt.%, from about 0.5 wt.% to about 2.5 wt.%, from about 0.8 wt.% to about2.5 wt.%, from about 1.0 wt.% to about 2.5 wt.%, from about 1.5 wt.% to about 2.5 wt.%, or from about 2.0 wt.% to about 2.5 wt.%, based on a total weight of the composition, including any and all ranges and subranges therein.

[0064] In any of the aspects disclosed herein, the synergistic additive and the fatty acid amide-based slip agent are included in the composition such that a molar ratio between a total number of moles of epoxy groups and ethylene oxide unit (-CH2-CH2-O-) groups present in the synergistic additive and a total number of moles of amide groups present in the fatty acid amide- based slip agent is from about 1 : 1 to about 3: 1.Properties and Articles

[0065] In any of the aspects described herein, in addition to the components described hereinabove, one or more additives can be incorporated into the self-lubricating siliconecomposition. Additives can include, by way of example and not limitation, colorants and dyes, carbon blacks, anti-static agents, anti-dust agents, mineral fillers, heat stabilizers, acid acceptors, adhesion promoters, tackifiers, mold releases, flame retardant / resistance additives, silicas and silicates, green strength additives, tensile modifiers, scavengers, and any other additive known and used in the art.

[0066] As described hereinabove, in various aspects, a masterbatch can be formed by melting the fatty acid amide-based slip agent, which is subsequently mixed with the synergistic additive, a silicone carrier, and, optionally, a filler. The masterbatch can include the fatty acid amide-based slip agent in an amount of from about 0.5 wt.% to about 75 wt.%, the synergistic additive in an amount of from about 1 wt.% to about 80 wt.%, and the silicone carrier in an amount of from about 0.5 wt.% to about 80 wt.%, based on a total weight of the masterbatch.

[0067] For example, the fatty acid amide-based slip agent may be included in the masterbatch in an amount of from about 0.5 wt.% to about 75 wt.%, from about 0.5 wt.% to about 70 wt.%, from about 0.5 wt.% to about 60 wt.%, from about 0.5 wt.% to about 50 wt.%, from about 0.5 wt.% to about 40 wt.%, from about 0.5 wt.% to about 30 wt.%, from about 0.5 wt.% to about 20 wt.%, from about 5 wt.% to about 75 wt.%, from about 5 wt.% to about 70 wt.%, from about 5 wt.% to about 60 wt.%, from about 5 wt.% to about 50 wt.%, from about 5 wt.% to about 40 wt.%, from about 5 wt.% to about 30 wt.%, from about 5 wt.% to about 20 wt.%, from about 10 wt.% to about 75 wt.%, from about 10 wt.% to about 70 wt.%, from about 10 wt.% to about 60 wt.%, from about 10 wt.% to about 50 wt.%, from about 10 wt.% to about 40 wt.%, from about 10 wt.% to about 30 wt.%, from about 10 wt.% to about 20 wt.%, from about 15 wt.% to about 75 wt.%, from about 15 wt.% to about 70 wt.%, from about 15 wt.% to about 60 wt.%, from about 15 wt.% to about 50 wt.%, from about 15 wt.% to about 40 wt.%, from about 15 wt.% to about 30 wt.%, or from about 15 wt.% to about 20 wt.%, based on a total weight of the masterbatch, including any and all ranges and subranges therein.

[0068] The synergistic additive may be included in the masterbatch in an amount of from about 1 wt.% to about 80 wt.%, from about 1 wt.% to about 70 wt.%, from about 1 wt.% to about 60 wt.%, from about 1 wt.% to about 50 wt.%, from about 1 wt.% to about 40 wt.%, from about 1 wt.% to about 30 wt.%, from about 1 wt.% to about 20 wt.%, from about 5 wt.% to about 80 wt.%, from about 5 wt.% to about 70 wt.%, from about 5 wt.% to about 60 wt.%, from about 5 wt.% to about 50 wt.%, from about 5 wt.% to about 40 wt.%, from about 5 wt.% to about 30 wt.%, from about 5 wt.% to about 20 wt.%, from about 10 wt.% to about 80 wt.%, from about 10 wt.% to about 70 wt.%, from about 10 wt.% to about 60 wt.%, from about 10 wt.% to about 50 wt.%, fromabout 10 wt.% to about 40 wt.%, from about 10 wt.% to about 30 wt.%, from about 10 wt.% to about 20 wt.%, from about 15 wt.% to about 80 wt.%, from about 15 wt.% to about 70 wt.%, from about 15 wt.% to about 60 wt.%, from about 15 wt.% to about 50 wt.%, from about 15 wt.% to about 40 wt.%, from about 15 wt.% to about 30 wt.%, or from about 15 wt.% to about 20 wt.%, based on a total weight of the masterbatch, including any and all ranges and subranges therein.

[0069] The silicone carrier may be included in the masterbatch in an amount of from about 0.5 wt.% to about 80 wt.%, from about 0.5 wt.% to about 70 wt.%, from about 0.5 wt.% to about 60 wt.%, from about 0.5 wt.% to about 50 wt.%, from about 0.5 wt.% to about 40 wt.%, from about 0.5 wt.% to about 30 wt.%, from about 0.5 wt.% to about 20 wt.%, from about 5 wt.% to about 80 wt.%, from about 5 wt.% to about 70 wt.%, from about 5 wt.% to about 60 wt.%, from about 5 wt.% to about 50 wt.%, from about 5 wt.% to about 40 wt.%, from about 5 wt.% to about 30 wt.%, from about 5 wt.% to about 20 wt.%, from about 10 wt.% to about 80 wt.%, from about 10 wt.% to about 70 wt.%, from about 10 wt.% to about 60 wt.%, from about 10 wt.% to about 50 wt.%, from about 10 wt.% to about 40 wt.%, from about 10 wt.% to about 30 wt.%, from about 10 wt.% to about 20 wt.%, from about 15 wt.% to about 80 wt.%, from about 15 wt.% to about 70 wt.%, from about 15 wt.% to about 60 wt.%, from about 15 wt.% to about 50 wt.%, from about 15 wt.% to about 40 wt.%, from about 15 wt.% to about 30 wt.%, or from about 15 wt.% to about 20 wt.%, based on a total weight of the masterbatch, including any and all ranges and subranges therein.

[0070] In some aspects, the masterbatch may also include a filler. The filler may comprise, silicas, silicates, hydrates, talc, limestone, sand, carbonates, carbon black, treated versions of any of the foregoing, or combinations thereof. The filler, when used, may be included in the masterbatch in an amount of from about 0.1 wt.% to about 66 wt.%, based on a total weight of the masterbatch. For example, the filler may be included in the masterbatch in an amount of from about 0.1 wt.% to about 66 wt.%, from about 0.1 wt.% to about 60 wt.%, from about 0.1 wt.% to about 50 wt.%, from about 0.1 wt.% to about 40 wt.%, from about 0.1 wt.% to about 30 wt.%, from about 0.1 wt.% to about 20 wt.%, from about 0.5 wt.% to about 66 wt.%, from about 0.5 wt.% to about 60 wt.%, from about 0.5 wt.% to about 50 wt.%, from about 0.5 wt.% to about 40 wt.%, from about 0.5 wt.% to about 30 wt.%, from about 0.5 wt.% to about 20 wt.%, from about 1 wt.% to about 66 wt.%, from about 1 wt.% to about 60 wt.%, from about 1 wt.% to about 50 wt.%, from about 1 wt.% to about 40 wt.%, from about 1 wt.% to about 30 wt.%, from about 1 wt.% to about 20 wt.%, from about 5 wt.% to about 66 wt.%, from about 5 wt.% to about 60 wt.%, from about 5 wt.% to about 50 wt.%, from about 5 wt.% to about 40 wt.%, from about 5 wt.% to about 30 wt.%, from about 5 wt.% to about 20 wt.%, from about 10 wt.% to about 66 wt.%, from about 10 wt.%to about 60 wt.%, from about 10 wt.% to about 50 wt.%, from about 10 wt.% to about 40 wt.%, from about 10 wt.% to about 30 wt.%, from about 10 wt.% to about 20 wt.%, from about 15 wt.% to about 66 wt.%, from about 15 wt.% to about 60 wt.%, from about 15 wt.% to about 50 wt.%, from about 15 wt.% to about 40 wt.%, from about 15 wt.% to about 30 wt.%, or from about 15 wt.% to about 20 wt.%, based on a total weight of the masterbatch, including any and all ranges and subranges therein.

[0071] Alternatively, the fatty acid amide-based slip agent and synergistic additive can be added to the silicone rubber base composition and the platinum catalyst system without creation of a separate masterbatch. The fatty acid amide-based slip agent, synergistic additive, silicone rubber base composition, and the platinum catalyst system can be mixed or blended in any suitable way to form the composition.

[0072] An article may be formed from the composition using any suitable method of molding or forming the composition, including, for example, injection molding, compression molding, dispenser molding, extrusion, and transfer molding. In aspects, the formed composition may be press cured and, optionally, subjected to a post-cure treatment to form a cured silicone product. The post-cure treatment can be carried out at an elevated temperature. For example, the post-curing treatment can be performed at about 150 °C for about 30 minutes, or at about 205 °C for about 2 hours to about 4 hours, or at about 35 °C for about 8 hours. Other time and temperature combinations for the post-cure treatment are contemplated and possible.

[0073] In any of the aspects described herein, the article may be a pharmaceutical package (e.g., a syringe), a stopper, a valve (e.g., a slit valve), tubing (e.g., catheter tubing or IV tubing), a seal or gasket, a cable jacket, a septum, or the like. The article may be incorporated into consumer devices, medical devices, electric devices, or the like. The article may also be incorporated into parts used in assembly processes for transportation applications and the like.

[0074] In various aspects, the post-cured silicone product may have an average dynamic coefficient of friction of less than 1 when measured using a dry, smooth steel substrate. For example, the post-cured silicone product may have an average dynamic coefficient of friction of from about 0.2 to about 0.9, from about 0.3 to about 0.7, or from about 0.4 to about 0.6, including any and all ranges and subranges therein.

[0075] The post-cured silicone product formed from the self-lubricating silicone compositions described herein may have a relative dynamic coefficient of friction of less thanabout 70% as compared to a post-cured silicone product formed from a composition not including the fatty acid amide-based slip agent and the synergistic additive but that is otherwise identical. The relative dynamic coefficient of friction can be calculated by dividing the average dynamic coefficient of friction of the post-cured silicone product formed from the composition described herein by the average dynamic coefficient of friction of the post-cured silicone product formed from the composition not including the fatty acid amide-based slip agent and the synergistic additive (e.g., the control) and multiplying by 100. In aspects, the relative dynamic coefficient of friction may be less than about 70%, less than about 65%, less than about 60%, less than about 55%, less than about 55%, less than about 50%, less than about 45%, less than about 40%, less than about 35%, or less than about 30%. In aspects, the relative dynamic coefficient of friction may be from about 20% to about 50%, from about 20% to about 40%, or from about 20% to about 30%, including any ranges and subranges therein.

[0076] In any of the aspects described herein, the post-cured silicone product may have an instantaneous Shore A hardness of greater than 30 when measured in accordance with ASTM D2240. For example, the post-cured silicone product may have an instantaneous Shore A hardness of from 30 to about 80, from about 40 to about 78, from about 50 to about 76, or from about 70 to about 75, including any ranges and subranges therein. Following an up to 10 second delay, the post-cured silicone product may have a Shore A hardness of greater than 30 when measured in accordance with ASTM D2240. For example, the post-cured silicone product may have a Shore A hardness after an up to 10 second delay of from about 30 to about 75, from about 55 to about 75 or from about 58 to about 72, including any ranges and subranges therein.

[0077] The post-cured silicone product may exhibit a stress at 50% strain of greater than about 165 psi at 20 in / min when measured in accordance with ASTM D412 (die C). For example, the post-cured silicone product may exhibit a stress at 50% strain from about 165 psi to about 320 psi, from about 168 psi to about 250 psi, or from about 170 psi to about 200 psi, including any ranges and subranges therein. In aspects, the post-cured silicone product may exhibit a stress at 50% strain from about 171 psi to about 190 psi.

[0078] In any of the aspects disclosed herein, the post-cured silicone product may exhibit a tensile elongation at break of greater than 400%, when measured in accordance with ASTM D412 (die C) at 20 in / min. For example, the post-cured silicone product may exhibit a tensile elongation at break of greater than 350%, when measured in accordance with ASTM D412 (die C) at 20 in / min. In aspects, the post-cured silicone product may exhibit a tensile elongation at break of greater than about 675%, greater than about 700%, or even greater than about 725%.

[0079] The post-cured silicone product may also exhibit a tensile strength at break of greater than 1000 psi when measured in accordance with ASTM D412 (die C) at 20 in / min. For example, the post-cured silicone product may exhibit a tensile strength at break of from about 1050 psi to about 1250 psi, from about 1075 psi to about 1200 psi, from about 1080 psi to about 1175 psi, or from about 1100 psi to about 1170 psi, including any ranges and subranges therein.

[0080] It is contemplated that, in any of the aspects disclosed herein, the stress at 50% strain, tensile elongation at break, and / or the tensile strength at break of the post-cured silicone product may have values outside of the ranges disclosed above. However, it should be understood that these values are comparable to that of a post-cured silicone product that does not include the fatty acid amide-based slip agent and synergistic additive but is otherwise identical.

[0081] In any of the aspects disclosed herein, the post-cured silicone product may exhibit a transmission of greater than 60% when measured in accordance with ASTM D1003. For example, the post-cured silicone product may exhibit a transmission of from about 60% to about 90%, from about 68% to about 85%, or from about 70% to about 73%, including any ranges and subranges therein.

[0082] The post-cured silicone product may also exhibit a haze of less than 110% when measured in accordance with ASTM D1003. For example, the post-cured silicone product may exhibit a haze of from about 50% to about 110%, from about 55% to about 105%, or from about 60% to about 103%, including any ranges and subranges therein.

[0083] In general, the cured silicone product exhibits a silky feel both prior to and following a post cure treatment as well as a decreased dust pick up as compared to a cured silicone product made from a composition that does not include the fatty acid amide-based slip agent and synergistic additive but is otherwise identical.

[0084] The general inventive concepts have been described above both generally and with regard to various specific aspects. Although the general inventive concepts have been set forth in what are believed to be exemplary illustrative aspects, a wide variety of alternatives will be apparent to those of skill in the art from reading this disclosure. The general inventive concepts are not otherwise limited, except for those instances when presented in specific claims.EXAMPLES

[0085] The following examples are included for the purposes of illustration, and do not limit the scope of the general inventive concepts described herein.

[0086] The materials provided in Table 1 below were used in the examples described herein. A conventional platinum cure silicone compound was employed as a base for each of the compositions, which included a vinyl silicone base, a vinyl-containing silicone gum, an inhibitor masterbatch, and a platinum catalyst masterbatch.Table 1.

[0087] Several compositions were prepared, including eight control (C1-C8) and four example compositions according to the aspects described herein (S1-S4). The compositions are provided in Tables 2 and 3 below, in which the values are reported as wt.%. In Tables 2, feel results describe whether the sample exhibited an acceptable, silky feel following the initial press cure or the post-cure treatment described in the table.Table 2.Table 3.

[0088] Each of Samples S1-S4 exhibited acceptable feel following the initial press cure as well as following at least some of the post-cure treatments, while Control Samples C1-C5 did not. This suggests that the Samples are able to withstand post cure treatments without losing the efficacy of the slip agent.

[0089] Hardness was measured in accordance with ASTM D2240. Average transmission and average haze were measured in accordance with ASTM DI 003. Hardness, transmission, and haze were measured following a post-cure treatment at 300 °F for 4 hours. Static coefficient of friction and dynamic coefficient of friction were measured according to an internal method using a dry, smooth steel substrate. The results are reported in Tables 4 and 5 below.Table 4.Table 5.

[0090] As shown in Tables 4 and 5, each of Samples S1-S4 had an average dynamic coefficient of friction of less than or equal to about 0.9 following post-cure treatments of 4 hours at 300 °F and 2 hours at 350 °F, while Comparative Samples C2, C4, C6, and C7 each had an average dynamic coefficient of friction of greater than or equal to 0.93 following a post-cure treatment of 2 hours at 350 °F. Comparative Samples C7 and C8 each had an average dynamiccoefficient of friction of greater than or equal to 1.0 following a post-cure treatment of 4 hours at300 °F.

[0091] Comparative Sample C3, which included 0.9 wt.% erucamide but no synergistic additive, exhibited an excellent improvement in the dynamic coefficient of friction, but, as reported above, did not exhibit acceptable feel following the post-cure treatments. Although Comparative Sample C5 exhibited similar improvements in the dynamic coefficient of friction, it also did not exhibit the acceptable feel following post-cure treatments. Accordingly, improvements over Comparative Samples C3 and C5 were desired. Comparative Samples C2, C4, and C6-C8 each exhibited increased dynamic coefficients of friction following post-cure treatments as compared to each of Comparative Samples C3 and C5 and were, therefore, not considered to be successful.

[0092] Every document cited herein is incorporated herein by reference in its entirety unless otherwise specified. The citation of any document is not to be construed as an admission that it is prior art with respect to any invention disclosed or claimed herein. To the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

[0093] It will be apparent that modifications and variations are possible without departing from the scope of the disclosure defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.

Claims

CLAIMSWhat is claimed is:

1. A composition comprising: a silicone rubber base composition comprising a vinyl silicone; a crosslinker comprising a hybrid hydride silicone having an average silicon hydride (Sill) content of at least 1 mmol / g; an inhibitor; a transition metal catalyst complex; from about 0.2 wt.% to about 2 wt.%, based on a total weight of the composition, of a fatty acid amide-based slip agent selected from the group consisting of a primary unsaturated fatty acid amide, a primary saturated and branched fatty acid amide, a secondary saturated fatty acid amide, and combinations thereof; and from about 0.2 wt.% to about 5 wt.%, based on the total weight of the composition, of a synergistic additive selected from the group consisting of an epoxy-containing silane; an epoxycontaining siloxane copolymer; a silicone polymer containing a polyethylene oxide segment; and combinations thereof.

2. The composition according to claim 1, wherein the fatty acid amide-based slip agent comprises a primary unsaturated fatty acid amide.

3. The composition according to any preceding claim, wherein the epoxy-containing silane in the synergistic additive is an epoxy-containing trialkoxysilane.

4. The composition according to any preceding claim, wherein the fatty acid amide-based slip agent comprises erucamide.

5. The composition according to any preceding claim, wherein the silicone rubber base composition further comprises a silicone resin selected from the group consisting of a methyl silicone, an -OH silicone, a phenyl silicone, a fluorosilicone, and combinations thereof.

6. The composition according to any preceding claim, wherein the silicone rubber base further comprises a silica and a silicone plasticizer.

7. The composition according to claim 6, wherein the silicone plasticizer comprises polydimethyl siloxane (PDMS).

8. The composition according to any preceding claim, wherein the inhibitor comprises ethynyl cyclohexanol.

9. The composition according to any preceding claim, further comprising one or more additives selected from the group consisting of colorants, carbon blacks, anti-static agents, antidust agents, mineral fillers, heat stabilizers, acid acceptors, adhesion promoters, tackifiers, mold releases, flame retardants, silicas, silicates, green strength additives, tensile modifiers, scavengers, antimicrobial additives, and combinations thereof.

10. The composition according to any preceding claim, wherein a molar ratio between a total number of moles of epoxy groups and ethylene oxide unit (-CH2-CH2-O-) groups present in the synergistic additive and a total number of moles of amide groups present in the fatty acid amide- based slip agent is from about 1 : 1 to about 3: 1.

11. A post-cured silicone product formed from the composition according to any preceding claim.

12. The post-cured silicone product according to claim 11, wherein the post-cured silicone product has an average dynamic coefficient of friction of less than 1 when measured on a dry, smooth stainless steel surface.

13. The post-cured silicone product according to claims 11 and 12, wherein the post-cured silicone product has an average dynamic coefficient of friction of less than 0.6 when measured on a dry, smooth stainless steel surface.

14. The post-cured silicone product according to any one of claims 11-13, wherein the postcured silicone product has a relative dynamic coefficient of friction of less than 50% as compared to a post-cured silicone product formed from a composition not including the fatty acid amide- based slip agent and the synergistic additive but is otherwise identical.

15. The post-cured silicone product according to any one of claims 11-14, wherein the postcured silicone product has an instantaneous Shore A hardness of greater than 30 when measured in accordance with ASTM D2240.

16. The post-cured silicone product according to any one of claims 11-15, wherein the postcured silicone product has a transmission of greater than 60% when measured in accordance with ASTM DI 003.

17. The post-cured silicone product according to any one of claims 11-16, wherein the postcured silicone product has a haze of less than 110% when measured in accordance with ASTM D1003.

18. A masterbatch comprising: a silicone carrier; a fatty acid amide-based slip agent selected from the group consisting of a primary unsaturated fatty acid amide, a primary saturated and branched fatty acid amide, and combinations thereof; a synergistic additive selected from the group consisting of an epoxy-containing silane; an epoxy-containing siloxane copolymer; and a silicone polymer containing a polyethylene oxide segment; and optionally, a filler.

19. The masterbatch according to claim 18, wherein the fatty acid amide-based slip agent comprises a primary unsaturated fatty acid amide.

20. The masterbatch according to claim 19, wherein the fatty acid amide-based slip agent comprises erucamide.

21. The masterbatch according to claim 18, wherein the fatty acid amide-based slip agent comprises a primary saturated and branched fatty acid amide.

22. The masterbatch according to claim 21, wherein the fatty acid amide-based slip agent comprises isostearic amide.

23. The masterbatch according to any one of claims 18-22, wherein the filler comprises a silica, a silicate, a hydrate, a carbonate, a carbon black, treated versions thereof, or combinations thereof.

24. The masterbatch according to any one of claims 18-23, wherein a molar ratio between a total number of moles of epoxy groups and ethylene oxide unit (-CH2-CH2-O-) groups present in the synergistic additive and a total number of moles of amide groups present in the fatty acid amide-based slip agent is from about 1 : 1 to about 3: 1.

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