Hydrosilylation catalyst inhibitor

Abstract

To provide an effective and reversible inhibitor of a hydrosilylation catalyst for extending the pot life of a hydrosilylation reaction mixture.SOLUTION: There is provided a composition comprising the following components: (a) a hydrosilylation catalyst containing a metal-ligand complex and (b) an inhibitor of a catalyst represented by the formula (1) which is different from a ligand of a metal-ligand complex, X-CHR-CO-Y (I) (wherein, -X is -NO2, -S(=O)R or Rc2RaC-CO-; Y is 2-furyl, -NO2 or -CRbXRd3-x; Ra and Rb are independently selected from -O-R, -NO2, -F, -Cl, -Br or the like; R are each independently selected from -H, an optionally fluorinated alkyl having 1 to 8 carbon atoms, -F or the like; Rc and Rd are independently selected from -H, an optionally fluorinated alkyl having 1 to 8 carbon atoms, -F or the like; x is 0 or 1.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to the use of novel inhibitors for hydrosilylation catalysts, compositions comprising catalysts and inhibitors, and processes for carrying out hydrosilylation reactions using catalysts and inhibitors. [Background technology]

[0002] Organoplatinum catalysts, such as Karstedt's catalyst (e.g., divinyltetramethyldisiloxane and chloroplatinic acid adduct), are used to catalyze hydrosilylation reactions, for example, to obtain cross-linked polydimethylsiloxane (PDMS). Typically, the reaction composition is pre-mixed before applying the catalyst. The high activity of platinum catalysts reduces the pot life of the composition. A pot life of several hours at room temperature is long enough for applications where the composition is cast or screen-printed. However, other applications of the composition require a longer pot life, such as those in inkjet printing disclosed by Sturgess ("3D reactive inkjet printing of polydimethylsiloxane", J. Mater. Chem. C, 2017, 5, 9733-9743) and Mikkonenetal ("Inkjet Printable Polydimethylsiloxane for All-Inkjet-Printed Multilayered Soft Electrical Applications"; ACS Appl. Mater. Interfaces 2020, 12, 10, 11990-11997). To extend the pot life of compositions used in inkjet printing, they may be refrigerated immediately after being transferred to a print cartridge. Refrigerated ink may be usable for several days. Another approach to reducing the viscosity of inkjet-printable compositions and thereby extending their pot life is to add a solvent. A known solvent is octyl acetate (OA), which is miscible with PDMS and provides a suitable vapor pressure for printing. Adding OA dilutes the composition and extends the pot life of the formulation.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The content of the solvent as a viscosity regulator and a pot life extender should not be too much in an inkjet-printable formulation. Therefore, the pot life of an inkjet-printable formulation is limited to a maximum of several hours. This brings significant practical and technical limitations to the applications of inkjet printing. The pot life and the viscosity of the formulation also pose problems in applications where no solvent is used in the formulation, such as in a method for manufacturing an LED including a step of dispensing the formulation with a syringe.

[0004] Therefore, the underlying problem of the present invention was to provide an effective and reversible inhibitor of a hydrosilylation catalyst for extending the pot life of a hydrosilylation reaction mixture.

Means for Solving the Problems

[0005] The underlying problem of the present invention is solved by providing a composition containing an inhibitor of a hydrosilylation catalyst, where the inhibition is effective and based on a reversible interaction. This application covers the following points [1] to

[15] . [1] A composition containing the following components. (a) A hydrosilylation catalyst containing a metal-ligand complex, and (b) An inhibitor of the catalyst, where the inhibitor is different from the ligand of the metal-ligand complex and is represented by the formula (I). X-CHR-CO-Y···(I) (In the formula, -X represents -NO2, -S(=O)R, or R c 2R a C-CO-; Y represents 2-furyl, -S(=O)R, -CN, -NO2, or -CR b X R d 3-x ; R a and R bis independently selected from the group consisting of -O-R, -O-CO-R, -CO-O-R, 2-furyl, -S(=O)R, -CN, -NO2, -F, -Cl, and -Br; each R is independently selected from the group consisting of -H, optionally fluorinated C1-C8-alkyl, -F, -Cl, and -Br; each R c and each R d is independently selected from the group consisting of -H, optionally fluorinated C1-C8-alkyl, -F, -Cl, and -Br; x is 0 or 1.) [2] The inhibitor (b) is the composition according to [1], represented by formula (II). R c 2R a C-CO-CHR-CO-Y···(II) (In the formula, the group is as defined in [1].) [3] The inhibitor (b) is the composition according to [1], represented by formula (III). R c 2R a C-CO-CHR-CO-CR b x R . d 3-x ···(III) (In the formula, the group is as defined in [1].) [3-1] In any one of the preferred embodiments from [1] to [3] above, the concentration of the inhibitor in the composition is higher than the concentration of the ligand of the metal-ligand complex. [3-2] In another preferred embodiment of any one of [1] to [3] above, the ligand of the metal-ligand complex is not a compound corresponding to each definition of the inhibitor (b). [3-3] In another preferred embodiment of any one of [1] to [3] above, the boiling point of the ligand of the metal-ligand complex is higher than the boiling point of the inhibitor (b). [3-4] A combination of the features of [3-1] and [3-2] is more preferred. [3-5] A combination of the features of [3-1] and [3-3] is more preferred. [3-6] A combination of the features of [3-2] and [3-3] is more preferred. [3-7] A combination of the features of [3-1], [3-2], and [3-3] is most preferred. [4] A composition according to any one of points [1] to [3-5], comprising the following ingredients. (a) A hydrosilylation catalyst comprising platinum(0) and an olefin ligand, and (b) An inhibitor represented by formula (I), (II), or (III) as defined by any one of [1] to [3-5]. An inhibitor of formula (III) is preferred. [5] -CR a R c 2 and -CR b x R d 3-x The composition according to any one of the preceding points, wherein at least one of is -CF3. [6] The composition described in any one of the preceding points, comprising the following components: (c) a silane (siloxane) having an olefin group, and (d) a silane (siloxane) containing hydrogen directly bonded to silicon. [7] The composition described in any one of the preceding points, comprising the following components: (c) vinyl-containing polysiloxane, and (d) polysiloxane containing hydrogen directly bonded to silicon. [8] The composition according to any one of the preceding points, wherein the hydrosilylation catalyst is a complex of platinum(0) and a divinyl-containing disiloxane. [9] Composition (b): The composition according to any one of the preceding points, wherein the weight ratio of ((c) + (d)) is from 3:100 to 20:100.

[10] The composition according to any one of the preceding points, wherein composition (e) contains a solvent that does not fall under any of the definitions of composition (a) to composition (d).

[11] Two packages of a hydrosilylated system, wherein the first package comprises a silane (siloxane) containing hydrogen directly bonded to silicon, and the second package comprises the composition according to any one of points [1] to [5] and a silane (siloxane) having an olefin group; or, the first package comprises the composition according to any one of points [1] to [5] and a silane (siloxane) containing hydrogen directly bonded to silicon, and the second package comprises a silane (siloxane) having an olefin group.

[12] The hydrosilylation process includes the following steps. (i) Provide a reaction system comprising the following compositions: (a) Hydrosilylation catalysts containing metal-ligand complexes, and (b) An inhibitor of the catalyst, wherein the inhibitor is different from the ligand of the metal-ligand complex and is represented by formula (I), (II), or (III). X-CHR-CO-Y···(I) (In the formula, -X is -NO2, -S(=O)R, or R) c 2R a C-CO- represents; Y is 2-frill, -S(=O)R, -CN, -NO2, or -CR b X R d 3-x Represents; R a and R b R is independently selected from the group consisting of -OR, -O-CO-R, -CO-OR, 2-furyl, -S(=O)R, -CN, -NO2, -F, -Cl, and -Br; each R is independently selected from the group consisting of -H, optionally fluorinated C1-C8-alkyl, -F, -Cl, and -Br; each R c and each R d x is independently selected from the group consisting of -H, optionally fluorinated C1-C8-alkyl, -F, -Cl, and -Br; x is 0 or 1. R c 2R a C-CO-CHR-CO-Y···(II) (In the formula, the group is defined with respect to formula (I).) R c 2R a C-CO-CHR-CO-CR b x R d 3-x ...(III) (In the formula, the group is defined with respect to formula (I).) (c) Silanes (siloxanes) containing an olefin group, and (d) Silanes (siloxanes) containing hydrogen directly bonded to silicon. (ii) A hydrosilylation reaction is carried out to crosslink composition (C) and composition (d). (iii) Remove the inhibitor at least partially from the reaction system. The hydrosilylation reaction in step (ii) may be initiated and / or accelerated by step (iii). [12-1] In the embodiment of

[12] , the inhibitor is not completely removed from the reaction system in step (iii).

[13] A crosslinking product obtained by the method described in

[12] . [13-1] In one embodiment of the present invention, the crosslinking product of

[13] comprises the inhibitor which is not completely removed in step (iii) of the process of

[12] or [12-1]. In other words, [13-1] relates to a composition comprising the crosslinking product and the inhibitor. [13-2] A preferred embodiment of [13-1] is that the concentration of the crosslinking product, i.e., the inhibitor in the composition, is from 0.0000001 wt% to 5 wt%, preferably from 0.000001 wt% to 1 wt%, more preferably from 0.0001 wt% to 1 wt%, and most preferably from 0.0001 wt% to 0.1 wt%.

[14] Use of compounds of the following formulas (I), (II), or (III) as inhibitors of hydrosilylation reactions using catalysts containing metal-ligand complexes. Here, the compound differs from the ligand of the metal-ligand complex: X-CHR-CO-Y···(I) (In the formula, -X is -NO2, -S(=O)R, or R) c 2R a C-CO- represents; Y is 2-frill, -S(=O)R, -CN, -NO2, or -CR b X R d 3-x Represents; R a and R b R is independently selected from the group consisting of -OR, -O-CO-R, -CO-OR, 2-furyl, -S(=O)R, -CN, -NO2, -F, -Cl, and -Br; each R is independently selected from the group consisting of -H, optionally fluorinated C1-C8-alkyl, -F, -Cl, and -Br; each R c and each R d x is independently selected from the group consisting of -H, optionally fluorinated C1-C8-alkyl, -F, -Cl, and -Br; x is 0 or 1. R c 2R a C-CO-CHR-CO-Y···(II) (In the formula, the group is as defined for formula (I).) R c 2R a C-CO-CHR-CO-CR b x R d 3-x ...(III) (In the formula, the group is as defined for formula (I).)

[15] The hydrosilylation reaction is carried out in a composition that is inkjet printed or administered by syringe, as described in

[14] . [Effects of the Invention]

[0006] The inhibitor is effective and has no acute toxicity. The addition of small amounts of the inhibitor extends the shelf life of one-component polymer systems, including the composition or catalyst, and extends the pot life of two-component polymer systems, including the catalyst, after the components have been mixed.

[0007] The inhibitor can be used, for example, in inkjet-printable compositions and can be easily adapted to other printing technologies such as aerosol jetting and screen printing. Therefore, a range of novel and innovative manufacturing possibilities are available in the fields of 2D and 3D printing. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows the viscosity of a PDMS resin (Sylgard184; PDMS base:curing agent = 10:1 wt / wt) over a period of 120 minutes at 40°C, compared to the same resin containing 15 wt% 1,1,1-trifluoroacetylacetone (TFAA) (Example 5). [Modes for carrying out the invention]

[0009] Where used herein, the singular forms “a,” “an,” and “the” may also include the plural form unless the context clearly indicates otherwise. For example, structural elements and components are generally described in the singular form, such as “an” inhibitor or “containing a” component. Such singular formulations mean that they contain two or more of the components or structural elements described, unless otherwise indicated. The term “and / or” includes all combinations of one or more of the enumerated items relating to the subject. The verbs “contain,” “comprise,” and “have” are inclusive and thus indicate the presence of the described function, step, element, or component or combination thereof, but do not exclude the presence or addition of one or more other functions, steps, elements, components or groups thereof or combinations thereof. The steps and processes of the methods described herein should not be construed as necessarily requiring their performance in a specific order described or illustrated unless specifically indicated as the order of performance. As used herein, the term “silane (siloxane)” is intended to be equivalent to the term “(poly)silane or (poly)siloxane or both,” where “poly” means two or more degrees of polymerization.

[0010] The inhibitors used in this invention suppress the activity of the catalyst used in the hydrosilylation reaction. The hydrosilylation reaction crosslinks a silicon compound containing an olefin group with a silicon compound containing hydrogen. The groups to be crosslinked may be contained in the same molecule (one-component system) or in separate molecules (two-component system), such as polymethylhydrosiloxane and polymethylvinylsiloxane. The reaction can be induced thermally or by exposure to UV light. The crosslinked, i.e., cured reaction product is referred to herein as a "silicone elastomer." The degree of crosslinking is not limited and may be as high as the silicone being a cured polymer rather than an elastomer polymer.

[0011] The organoplatinum catalyst that may be used in the present invention is a karsted catalyst (hereinafter simply referred to as the "catalyst") disclosed in U.S. Patent No. 3,814,730. The catalyst contains platinum in a zero-oxidation state that does not contain coordination chlorides. The catalyst contains a complex of platinum(0) and an olefin group in the absence of an inhibitor. Preferably, the olefin ligand of the catalyst is an olefin group of a silane and / or siloxane used as a reactant in the hydrosilylation reaction. More preferably, the olefin ligand is an olefin group of a polyorganosiloxane containing at least two olefin groups directly bonded to a silicon atom per molecule. A specific example is polymethyldivinylsiloxane, preferably a divinyl-containing disiloxane. This catalyst facilitates a low-temperature hydrosilylation reaction and forms a silicone elastomer by an addition-crosslinking reaction between the Si-vinyl group and the Si-H group.

[0012] The inhibitors used in accordance with the present invention, or included in the compositions or two-package hydrosilylation systems of the present invention, are inhibitors of formula (I), (II), or (III), and may hereafter be simply referred to as “inhibitors.” The inhibitors interact reversibly with the catalyst.

[0013] The compositions of the present invention comprise (a) a hydrosilylation catalyst comprising a metal-ligand complex, and (b) a catalyst inhibitor of formula I), (II), or (III). The metal-ligand complex of component (a) comprises a metal and at least one ligand. Thus, the compositions of the present invention comprise at least three components, namely a metal, a ligand, and an inhibitor. The ligand of the metal-ligand complex of the catalyst is different from that of the inhibitor of component (b). Preferably, the ligand is not a compound of formula I), (II), or (III). Ligands and inhibitors have different catalytic capabilities when combined with metals. This means that a composition of metals and ligands capable of forming the metal-ligand complex of component (a) has higher activity as a hydrosilylation catalyst than a composition of metal and inhibitor alone. Thus, the catalytic activity of a composition comprising a metal, ligand, and inhibitor can be increased by removing the inhibitor and / or adding the ligand, and can be decreased by removing the ligand and / or adding the inhibitor. In this way, ligands and inhibitors can be clearly identified and distinguished in the composition. Another difference between ligands and inhibitors is that ligands have a higher boiling point. This difference allows inhibitors to be selectively removed by increasing the temperature, and thus the hydrosilylation reaction can be easily accelerated.

[0014] As explained below, the structural characteristics of the inhibitor are the substituent R a and optionally substituent R b From R d This is the negative inductive effect of R. Preferably, a is a halogen atom selected from fluoro, chloro, and bromo. More preferably, R a , and R C At least one of them is a halogen atom. Most preferably, R a and R C R represents two or three halogen atoms together. C , R b , and R dOther groups represented by represent hydrogen. Particularly preferred compounds are HF2C-CO-CH2-CO-CH3, F3C-CO-CH2-CO-CH3, HF2C-CO-CH2-CO-CF3, F3C-CO-CH2-CO-CF3, Cl3C-CO-CH2-CO-CH3, and Cl3C-CO-CH2-CO-CCl3.

[0015] The inhibitors are compounds of formula (I), (II), or (III), i.e., 1,3-diketones (acetylacetone derivatives) or compounds similar to 1,3-diketones. 1,3-diketones, which can tautomerize to enols conjugated to other carbonyls, usually exist primarily in enol form, especially where the product can be further stabilized by a six-membered ring containing hydrogen bonds. For example, the enol percentages of acetylacetone, 1,1,1-trifluoroacetylacetone (TFAA), and hexafluoroacetylacetone are 85, 97, and 100%, respectively. 1,3-diketones and metals can form metal acetylacetonate coordination complexes. Hexafluoroacetylacetonates and trifluoroacetylacetonates often form complexes structurally related to ordinary acetylacetonates, but are more Lewis acidic and volatile. Therefore, they are not only more effective as inhibitors but can also be more easily removed by evaporation. Example 3 shows that acetylacetone is not effective as an inhibitor.

[0016] While we do not wish to be bound by theory, the inventors hypothesize that inhibitors affect the activity of catalysts used in a type of "allosteric" control. It is thought that inhibitors may complexe the active metal of the catalyst. Due to the negative inductive effect of substituents such as trifluoro groups, inhibitors become more Lewis acidic. Since the complex is not very strong, a chemical equilibrium can be maintained between the complex and the free ligand. Example 4 demonstrates that the inhibition of the catalyst is completely reversible. When the inhibitor is removed from the composition, for example by evaporation, the catalyst returns to its original active state and crosslinking proceeds normally.

[0017] Amines and other compounds capable of complexing the active metal center of the catalyst can inhibit crosslinking in a similar manner to the inhibitors used in the present invention. However, inhibition by amines has been found to be irreversible or only partially reversible. This is thought to be because a stable complex is formed between the amine (base) and the metal center (which has acidic properties). Example 4 shows that inhibition of the catalyst by primary and secondary amines is irreversible, even at temperatures above the boiling points of these amines. In the case of tertiary amines, very limited reversibility is observed, preventing crosslinking and resulting in a very soft, incompletely cured silicone elastomer. Furthermore, in the case of tertiary amines, the required curing time is too long for useful practical applications. Moreover, most primary, secondary, and tertiary amines are acutely toxic and produce toxic vapors.

[0018] The boiling point of the inhibitor may be below 120°C. For example, the boiling points of TFAA and hexafluoroacetylacetone are 105-107°C and 70-71°C, respectively. In comparison, the boiling points of acetylacetone and OA are 140°C and 211°C, respectively. For example, reactions catalyzed by organoplatinum catalysts can be accelerated by removing the inhibitor by evaporation at high temperature and / or reduced pressure.

[0019] The organic platinum catalyst is preferably used in an amount of at least 0.1 ppm, more preferably 1 to 50 ppm, of platinum metal per 100 parts of the olefin group-containing compound. The hydrogen-containing crosslinking agent is preferably used in an amount of 1 to 50 parts, more preferably 1 to 25 parts, of the olefin group-containing compound per 100 parts.

[0020] The amount of inhibitor compound added to the composition will vary depending on the specific application of the composition. Preferably, the concentration of the inhibitor in the composition is higher than the concentration of the ligand in the metal-ligand complex, or higher than the concentration of the metal in the metal-ligand complex. More preferably, the concentration of the inhibitor may be 5 times or more, 10 times or more, or 100 times or more higher than the concentration of the metal in the metal-ligand complex. The higher the level of inhibitor present, the longer the storage stability of the composition will be for a one-component system, and for a two-component system, the composition will have a longer pot life. For most applications, the concentration of the inhibitor may be 0.01 to 200 parts by weight, preferably 0.01 to 10 parts by weight, per 100 parts of the base olefinic compound.

[0021] The composition of the present invention may comprise a one-component polymer system comprising a catalyst and an inhibitor, or the composition may comprise a catalyst, an inhibitor, and one component of a two-component polymer system, such as a vinyl component of a PDMS system. In either case, the inhibitor extends the shelf life of the composition. After mixing the components of a two-component polymer system, such as a PDMS system, the inhibitor extends the pot life of the system.

[0022] In the two-package hydrosilylation system of the present invention, the reactive components of the two-component polymer system are placed in separate containers. This means that the olefin group-containing polymer, such as a vinyl-containing polymer, is placed in a separate container from the hydride crosslinking agent. The inhibitor can be placed in a container together with the olefin group-containing compound, or together with the hydride crosslinking agent. The catalyst is preferably compounded or mixed with the olefin group-containing polymer. In most cases, it is preferable to mix the inhibitor with the catalyst in the olefin group-containing compound.

[0023] The composition may also be a single package system, where all components are mixed together, and the composition is utilized simply by heating at a high temperature to produce a cured silicone elastomer by evaporating the inhibitor. In the case of a single package system, the amount of inhibitor may exceed 15 parts per 100 parts of the olefin group-containing compound to extend the shelf life of the composition.

[0024] Olefin group-containing compounds, such as vinyl-containing polysiloxanes, are preferably low viscosity and act as both diluents and reinforcing agents for the final curing of the elastomer. The olefin group-containing compound may be a polymer or a mixture of olefin group-containing polymers, more specifically, a mixture of an olefin group-containing polymer and other olefin group-containing polymers having olefin units, such as vinyl units at both terminal and internal positions of polymer chains, such as polysiloxane chains. The hydrogen-containing crosslinking agent may be any that is commonly used in hydrosilylation reactions for forming silicone elastomers, and may preferably be a hydrogen-containing polysiloxane with a viscosity of 1 to 10,000 mPa·s at 25°C. Furthermore, various other additives may be added to the composition, such as fillers and pigments, thermal aging additives, and other types of additional components commonly associated with the manufacture of such compositions.

[0025] Vinyl-containing polysiloxanes preferably contain 0.01 to 1 mole percent of vinyl. Preferably, the polymer is linear, and preferably the vinyl is located at the terminal positions of the linear polymer chain. However, the vinyl group may be present at any part of the polymer chain. The polymer may be a single polymer species or a blend of vinyl-containing polymer materials. In addition to the vinyl radical, other substituents may be any monovalent hydrocarbon radical or halogenated monovalent hydrocarbon radical, preferably not exceeding 10 carbon atoms. Most preferably, substituents bonded to silicon are selected from lower alkyl radicals, vinyl radicals, and phenyl radicals with 1 to 8 carbon atoms. The most preferred polymer species within the range of vinyl-containing polymers is a strictly linear polymer having vinyl radical terminal units.

[0026] An example of a two-component silicone elastomer system is Polytek PlatSil® 71-Silliglass (Sturgess et al.), which contains a silicone hydride and a portion of vinyl-containing silicone in PDMS A, and a portion of vinyl-containing silicone and a catalyst in PDMS B. The inhibitor used in this invention can be added to any corresponding component of PDMS A or PDMS B disclosed by Sturgess et al.

[0027] Another example of a two-component silicone elastomer system is SYLGARD® 184, which comprises a polymer base and a curing agent that crosslinks with the polymer matrix. The resulting composite material is polydimethylsiloxane (PDMS) with a tensile strength (UTS) of approximately 5.2 MPa and a Shore hardness of approximately 44 at room temperature. Tensile strength, hardness, and Young's modulus (E) increase with increasing curing temperature. Pot life is 1.5 hours at 25°C and is defined as the time required for the viscosity to double after mixing the base and curing agent. The initial viscosity of the mixture is 3500 Pa·s. Curing time varies with temperature: 48 hours at 25°C, 35 minutes at 100°C, 20 minutes at 125°C, and 10 minutes at 150°C. As shown in Example 5, the increase in viscosity can be suppressed over a long period of time. Thus, the pot life of the composition can be extended.

[0028] It is not possible to completely remove the inhibitor from the hydrosilylation reaction system by raising the temperature above the boiling point of the inhibitor. As a result, the reaction product of the hydrosilylation reaction will inevitably contain a detectable amount of the inhibitor, which can be quantitatively detected by methods such as GC-MS. Therefore, the reaction product prepared using the inhibitor of the present invention is different from the reaction product not prepared using such an inhibitor. In other words, the crosslinked product according to the present invention is different from the product of the prior art.

[0029] GC-MS is a highly sensitive method that can easily detect concentrations in the ppb (parts per billion) range, i.e., concentrations of 0.0000001 wt% or less.

[0030] The inhibitor is present in the reaction system in a diluted form. Interaction with diluents, such as solvents, prevents the complete removal of the inhibitor even when the temperature is raised to the inhibitor's boiling point. The inventors have demonstrated in experiments that a solution containing 5 wt% TFAA with a boiling point of 107°C still contains a considerable amount of TFAA even after heating at 120°C for a longer period (e.g., 1 hour).

[0031] Hydrosilylation systems contain polymerization raw materials, catalysts, and inhibitors. Inhibitors physically interact with other components of the reaction system. In particular, it can be inferred that inhibitors can form complexes with the catalyst's metal. Therefore, it is impossible to completely remove inhibitors by heating, and under normal reaction conditions, residual inhibitors are always present in the reaction product. This residual amount can be detected by methods such as GC-MS. If necessary, low-molecular-weight inhibitors can be extracted from the polymer polymerization product before performing GC-MS. Silicone elastomer systems such as PDMS can be used as stamping resins for soft lithography in various applications such as microfluidics, microelectromechanical systems (MEMS), and other flexible electronic devices. They also form hydrophobic PDMS films that can be used as moisture films in solar cells. Furthermore, due to its low cost, ease of manufacture, flexibility, and optical transparency, PDMS is an ideal material for prototype manufacturing in diverse research and development fields.

[0032] A possible use of PDMS is inkjet printing. The use of PDMS systems in inkjet printing, materials and methods, and applications of inkjet-printed PDMS systems are disclosed in detail by Mikkonen et al. and Sturgess et al.

[0033] For use in inkjet printing, a solvent must be added to reduce viscosity. The solvent, on the other hand, must have a low boiling point so that it can be removed after printing. In this invention, the solvent (component (e)) has a molecular weight of less than 250 g / mol and a boiling point of less than 250°C. The solvent does not fall under any of the definitions of components (a) through (d). In particular, the solvent does not contain a catalytic metal, is not a compound of formula (I), (II), or (III), and is not a silane or siloxane. Examples of suitable solvents are organic solvents such as octyl acetate (OA), n-butyl acetate, or isobutyl acetate, or acetylacetone.

[0034] Mikkonen et al. disclosed the use of OA as a solvent. Because the two components of Sylgard184 were mixed before printing, the cartridge temperature had to be kept as low as possible, which hindered the crosslinking of the PDMS component. The 1:2 PDMS-OA solution was too viscous, requiring the cartridge to be heated to over 35°C. However, heating promotes crosslinking. Both 1:3 and 1:4 PDMS-OA solutions allowed printing without heating the cartridge above 30°C. A 1:3 PDMS-OA solution was used to maximize the PDMS content of the ink.

[0035] As shown in Figure 1, the inhibitor used in the present invention not only suppresses the increase in viscosity over time, but also initially reduces viscosity. Therefore, the inhibitor can at least partially replace component (e) in its function as a solvent used to adjust the viscosity of a composition for use in inkjet printing. [Examples]

[0036] In the following examples, the component ratios are by weight, and % are by weight. The PDMS used in the examples was a premixture of two components of SYLGARD® 184 (PDMS base:curing agent = 10:1). 1,1,1-trifluoroacetylacetone (TFAA) was used as an inhibitor. (Example 1)

[0037] As disclosed by Mikkonen et al., PDMS was diluted with OA in a 1:2 ratio. Furthermore, TFAA was added at different concentrations.

[0038] PDMS + OA (1:2) + TFAA (1.5% to 90% relative to PDMS)

[0039] The container was sealed and stored at 80°C for 48 hours. As a result, curing occurred normally at concentrations up to 6% (compared to PDMS), but curing was normally suppressed at increased concentrations of 15% (compared to PDMS) or higher. (Example 2)

[0040] As described in Example 1, PDMS was diluted with OA (1:2). Intermediate concentrations (6%, 9%, and 12%, relative to PDMS, respectively) were included, and it was shown that the minimum concentration that inhibited curing was between 9% and 12%. (Example 3)

[0041] As described in Example 1, PDMS was diluted with OA (1:2), and acetylacetone was added at different concentrations.

[0042] PDMS + OA (1:2) + acetylacetone (3% to 30% relative to PDMS)

[0043] Acetylacetone was found to be ineffective at all concentrations used. (Example 4)

[0044] In preliminary experiments, propylamine, pyrrolidine, and triethylamine were tested at 15% concentrations as examples of primary, secondary, and tertiary amines, respectively, and all successfully inhibited crosslinking.

[0045] Next, the reversibility of successful inhibition was tested. The open containers were placed in a 60°C oven for 24 hours to evaporate the additives. Reversibility was observed with all TFAA mixtures; that is, crosslinking occurred during the evaporation of TFAA. Higher concentrations of TFAA resulted in a softer surface, indicating that the elastomer had not fully hardened. Conversely, no reversibility was observed with propylamine, pyrrolidine, and triethylamine. Crosslinking was inhibited, and the material remained liquid.

[0046] Next, higher temperatures and vacuum were used to accelerate the evaporation of the additives and demonstrate the potential reversibility of the inhibition. 72 hours at 80°C and 100 mbar showed that the inhibition was completely reversible even at high TFAA concentrations. In the case of propylamine and pyrrolidine, the experiment showed a completely irreversible reaction, and the material remained liquid. In the case of triethylamine, very limited reversibility was observed, preventing crosslinking and resulting in a very "sticky" elastomer that was not fully cured. (Example 5)

[0047] In long-term rheological measurements, undiluted PDMS was compared with undiluted PDMS containing TFAA (15%) to show the progression of crosslinking over time. Figure 1 shows the viscosity of PDMS and the same resin containing 15% TFAA at 40°C for 120 minutes.

Claims

1. A composition comprising the following components: (a) a hydrosilylation catalyst comprising a metal-ligand complex; and (b) an inhibitor for said catalyst, said inhibitor being different from the ligand of said metal-ligand complex and having the formula (I): X-CHR-CO-Y...(I) (Wherein, -X is -NO ２ , -S(=O)R, or R ｃ ２ R ａ represents C-CO-; Y represents 2-furyl, -S(=O)R, -CN, -NO ２ , or -CR ｂ Ｘ R ｄ ３－ｘ Represents; R ａ and R ｂ is -O-R, -O-CO-R, -CO-O-R, 2-furyl, -S(=O)R, -CN, -NO ２ , -F, -Cl, and -Br; each R is independently selected from the group consisting of -H, optionally fluorinated C １ -C ８ -alkyl, -F, -Cl, and -Br; ｃ and each R ｄ is -H, optionally fluorinated C １ -C ８ -alkyl, -F, -Cl, and -Br; and x is 0 or 1.

2. The composition of claim 1 , wherein the inhibitor (b) is represented by formula (II): R ｃ ２ R ａ C-CO-CHR-CO-Y・・・(II) wherein the groups are as defined in claim 1.

3. The composition of claim 1 , wherein the inhibitor (b) is represented by formula (III): R ｃ ２ R ａ C-A-CHR---CR ｂ ｘ R ｄ ３－ｘ ・・・(III) wherein the groups are as defined in claim 1.

4. 2. A composition according to any one of the preceding claims, comprising the following components: (a) a hydrosilylation catalyst comprising platinum(0) and an olefinic ligand; and (b) an inhibitor of formula (I), (II), or (III) as defined in the preceding claims;

5. -CR ａ R ｃ ２ and -CR ｂ ｘ R ｄ ３－ｘ At least one of is -CF ３ That is, The composition of claim 1.

6. 2. The composition of claim 1 comprising the following components: (c) silanes (siloxanes) containing olefinic groups, and (d) silanes (siloxanes) containing hydrogen bonded directly to silicon.

7. 2. The composition of claim 1 comprising the following components: (c) vinyl-containing polysiloxanes, and (d) polysiloxanes containing hydrogen bonded directly to silicon.

8. the hydrosilylation catalyst is a complex of platinum(0) and a divinyl-containing disiloxane; The composition of claim 1.

9. the weight ratio of composition (b):((c)+(d)) is from 3:100 to 20:100; The composition of claim 1.

10. Composition (e) contains a solvent not falling within any of the definitions of compositions (a) to (d). The composition of claim 1.

11. The first package contains a silane (siloxane) containing hydrogen bonded directly to silicon, and the second package contains the composition of any one of claims 1 to 5 and a silane (siloxane) having an olefinic group; or the first package contains the composition of any one of claims 1 to 5 and a silane (siloxane) containing hydrogen bonded directly to silicon, and the second package contains a silane (siloxane) having an olefinic group. Two packages of hydrosilylation systems.

12. A hydrosilylation process comprising the steps of: (i) providing a reaction system comprising the following composition: (a) a hydrosilylation catalyst comprising a metal-ligand complex; and (b) an inhibitor for said catalyst, said inhibitor being different from the ligand of said metal-ligand complex and having formula (I), (II) or (III); X-CHR-CO-Y...(I) (Wherein, -X is -NO ２ , -S(=O)R, or R ｃ ２ R ａ represents C-CO-; Y represents 2-furyl, -S(=O)R, -CN, -NO ２ , or -CR ｂ Ｘ R ｄ ３－ｘ Represents; R ａ and R ｂ is -O-R, -O-CO-R, -CO-O-R, 2-furyl, -S(=O)R, -CN, -NO ２ , -F, -Cl, and -Br; each R is independently selected from the group consisting of -H, optionally fluorinated C １ -C ８ -alkyl, -F, -Cl, and -Br; ｃ and each R ｄ is -H, optionally fluorinated C １ -C ８ -alkyl, -F, -Cl, and -Br; and x is 0 or 1. R ｃ ２ R ａ C-CO-CHR-CO-Y・・・(II) wherein said groups are as defined for formula (I). R ｃ ２ R ａ C-A-CHR---CR ｂ ｘ R ｄ ３－ｘ ・・・(III) wherein said groups are as defined for formula (I). (c) silanes (siloxanes) containing olefinic groups, and (d) silanes (siloxanes) containing hydrogen directly bonded to silicon (ii) carrying out a hydrosilylation reaction to crosslink composition (C) and composition (d); (iii) at least partially removing the inhibitor from the reaction system.

13. A crosslinked product obtainable by the method of claim 12.

14. 1. Use of a compound of formula (I), (II) or (III) below as an inhibitor of a hydrosilylation reaction using a catalyst comprising a metal-ligand complex, The compound of formula (I), (II) or (III) is different from the ligand of the metal-ligand complex. X-CHR-CO-Y...(I) (Wherein, -X is -NO ２ , -S(=O)R, or R ｃ ２ R ａ represents C-CO-; Y represents 2-furyl, -S(=O)R, -CN, -NO ２ , or -CR ｂ Ｘ R ｄ ３－ｘ Represents; R ａ and R ｂ is -O-R, -O-CO-R, -CO-O-R, 2-furyl, -S(=O)R, -CN, -NO ２ , -F, -Cl, and -Br; each R is independently selected from the group consisting of -H, optionally fluorinated C １ -C ８ -alkyl, -F, -Cl, and -Br; ｃ and each R ｄ is -H, optionally fluorinated C １ -C ８ -alkyl, -F, -Cl, and -Br; and x is 0 or 1. R ｃ ２ R ａ C-CO-CHR-CO-Y・・・(II) wherein the groups are as defined for formula (I). R ｃ ２ R ａ C-A-CHR---CR ｂ ｘ R ｄ ３－ｘ ・・・(III) wherein the groups are as defined for formula (I).

15. The hydrosilylation reaction is carried out in an inkjet printed composition or in a syringe administered composition.

15. The use according to claim 14.

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