Storage-stable binary curable organopolysiloxane composition

Abstract

The dual cure organopolysiloxane composition contains (a) a first organopolysiloxane containing an average of two or more mercaptoalkyl groups per molecule and no alkenyl functionality; (b) a second organopolysiloxane containing an average of one or more alkenyl groups per molecule and an average of one or more hydrolyzable groups per molecule; (c) an optional third organopolysiloxane having at least two or more alkenyl groups per molecule and no alkoxy groups; (d) a bisacylphosphine oxide photoinitiator; (e) an optional carrier fluid; (f) a condensation catalyst; (f) a silane containing an average of two or more hydrolyzable groups per molecule; and (h) a radical scavenger.

Description

[Technical Field]

[0001] The present invention relates to an organopolysiloxane composition that can be cured by both ultraviolet (UV) light and moisture.

[0002] Introduction Organopolysiloxane systems that can undergo curing by two different mechanisms, i.e., binary curing, are becoming increasingly common. In particular, organopolysiloxane systems that undergo moisture curing in addition to ultraviolet (UV) curing are useful in many applications. The UV light curing mode of a composition rapidly initial-cures the composition, facilitating a continuous process or handling without damaging the coating in areas of the composition that may be exposed to UV light. The moisture curing mechanism cures the composition that is shielded from light exposure ("shaded areas") and also plays a role in curing the composition more completely over time. One type of UV / moisture binary curing system uses a thiol-ene chemistry for UV curing. Thiol-ene curing is preferred over the (meth)acrylate light curing mechanism because thiol-enes are not oxygen-sensitive like (meth)acrylate materials. Thiol-ene systems have a thiol-containing organopolysiloxane that, when exposed to UV light, reacts with carbon-carbon double bonds (alkenes) in other components of the reaction system to cause chemical crosslinking or curing. Binary curing systems utilizing thiol-ene chemistry typically involve thiol-containing organopolysiloxanes and unsaturated organopolysiloxane reaction products.

[0003] Thiol-ene-based UV and moisture-curing binary systems tend to suffer from relatively short shelf life compared to moisture-curing-only systems or thiol-ene UV-curing-only siloxane systems. Shelf life can be evaluated by determining whether the composition undergoes an increase in viscosity and / or a decrease in curing depth during UV curing and / or an increase in the time required to become a non-stick surface due to moisture curing after storage, compared to when the composition was newly prepared.

[0004] International Publication No. 2020 / 076620 attempts to address the shelf life problem of thiol-ene-based binary curing formulations by providing a thiol-ene binary curing organopolysiloxane system that requires an epoxy compound to stabilize the formulation.

[0005] It is desirable to identify a bicurable polyorganosiloxane system that undergoes moisture curing and thiol-ene UV curing, achieving storage stability without the need for epoxy compounds, and that can be aged for 21 days in a syringe in a vacuum-sealed aluminum bag in the dark at 55 degrees Celsius (°C) to eliminate moisture, thereafter. (1) The viscosity increase is less than twice the fresh viscosity when measured according to ASTM D-1084 using a Brookfield DVII+P viscometer equipped with a cone spindle CPA-52Z compliant with ASTM D-1084 at 23+ / -2℃, and (2) 2 joules per square centimeter (J / cm²) 2 When exposed to UVA and UVB irradiation, it shall achieve a curing depth of at least 70%, preferably 80% or more, and more preferably 90% or more compared to a newly prepared identical composition, and preferably also achieve a curing depth of at least 8 millimeters (mm) before and after aging, and (3) Characterized by undergoing a moisture-curing non-stick time of 24 hours or less. [Overview of the project]

[0006] The present invention provides a binary curable polyorganosiloxane system that undergoes moisture curing and thiol-ene UV curing, has storage stability without requiring epoxy compounds, and is characterized by its storage stability being achieved by aging for 21 days in the dark at 55 degrees Celsius (°C) under vacuum to remove moisture, thereafter: (1) The viscosity increase is less than twice the fresh viscosity when measured according to ASTM D-1084 using a Brookfield DVII+P viscometer equipped with a cone spindle CPA-52Z compliant with ASTM D-1084 at 23+ / -2℃, and (2) 2 joules per square centimeter (J / cm²) 2 When exposed to UVA and UVB irradiation, it achieves a curing depth of at least 70%, preferably 80% or more, and more preferably 90% or more compared to a newly prepared identical composition, and furthermore, it can achieve a curing depth of at least 8 millimeters before and after aging, and (3) To provide a binary curing polyorganosiloxane system characterized by undergoing a moisture-curing non-stick time of 24 hours or less.

[0007] Surprisingly, it was found that including a diacylphosphine oxide photoinitiator in a binary curing polyorganosiloxane system yields a storage-stable binary curing system that satisfies the aforementioned requirements.

[0008] In a first aspect, the present invention is a binary curable organopolysiloxane composition comprising: (a) a first organopolysiloxane containing an average of two or more mercaptoalkyl groups per molecule and no alkenyl functional groups; (b) a second organopolysiloxane containing an average of one or more alkenyl groups and an average of one or more hydrolyzable groups per molecule; (c) optionally a third organopolysiloxane having at least two or more alkenyl groups per molecule and no alkoxy groups; (d) a bisacylphosphine oxide photoinitiator; (e) optionally a carrier liquid; (f) a condensation catalyst; (f) a silane having an average of two or more hydrolyzable groups per molecule; and (h) a radical scavenger.

[0009] The composition of the present invention is useful as a binary curable organopolysiloxane system. [Modes for carrying out the invention]

[0010] If the date is not indicated together with the number of the test method, the test method refers to the most recent test method as of the priority date of this document. References to test methods include both a reference to the association of the test and the test method number. In this specification, the following abbreviations and identifiers of test methods apply. ASTM refers to ASTM International methods, END refers to European Norm, DIN refers to Deutsches Institut fur Normung, ISO refers to International Organization for Standards, and UL refers to Underwriters Laboratory.

[0011] Products identified by trade names refer to the compositions available under those trade names as of the priority date of this document.

[0012] "Plurality" means two or more. "And / or" means "and, or alternatively". All ranges include the endpoints unless otherwise indicated.

[0013] "Liquid" means free-flowing at 25 degrees Celsius (°C).

[0014] "Polar liquid" refers to a liquid that can dissolve polar substances. To avoid misunderstanding, toluene is not considered a polar liquid.

[0015] "Hydrolyzable group" refers to a group that can form silanol in water when bonded to a silicon atom. Examples of hydrolyzable groups include alkoxy, oximino, acetoxy, and amino groups.

[0016] "Organopolysiloxane" is a polysiloxane having at least one organic group bonded to the polysiloxane backbone.

[0017] "Polysiloxane" is a polymer containing a plurality of siloxane units that are bonded to each other to form a siloxane backbone. Unless otherwise specified, the siloxane unit is R’3Si0 1 / 2 "M" type siloxane unit having a chemical structure of, R’2SiO 2 / 2 "D" type siloxane unit having a chemical structure of, R’SiO 3 / 2 "T" type siloxane unit having a chemical structure of, and SiO 4 / 2 "Q" type siloxane unit having a chemical structure of (wherein, at each occurrence, R’ may be any group, but generally is selected from hydrogen, hydroxyl, alkoxyl, mercapto, amino, hydrocarbyl, and substituted hydrocarbyl groups). The oxygen atom having a subscript of "1 / 2" multiple in a specific siloxane unit indicates an oxygen atom shared with another silicon atom of the siloxane backbone, and the numerator of the fraction indicates the number of shared oxygen atoms bonded to the silicon atom of the specific siloxane unit).

[0018] The present invention is a two-component curable organopolysiloxane composition. "Two-component curing" means that the organopolysiloxane component of the composition can undergo a crosslinking reaction by either exposure to ultraviolet (UV) light or exposure to moisture. The crosslinking reaction induced by UV light is a "thiol-ene" reaction between the thiol functional group of a mercaptoalkyl group and an alkene functional group. The crosslinking reaction induced by moisture is a reaction between hydrolyzable groups in different molecules).

[0019] The two-component curable organopolysiloxane composition contains, on average, 2 or more mercaptoalkyl groups per molecule, and can contain 3 or more, 4 or more, and even 5 or more mercaptoalkyl groups, and at the same time, generally contains 20 or less, 15 or less, 10 or less, 8 or less, and even 6 or less mercaptoalkyl groups, and contains a first organopolysiloxane that does not contain an alkenyl functional group).

[0020] Preferably, the first polyorganosiloxane consists of M-type and D-type siloxane units. For example, one desirable first organopolysiloxane is a linear organopolysiloxane having the chemical structure (I): [Chemical Formula] (wherein, R 1 is, independently at each occurrence, a hydrocarbyl or substituted hydrocarbyl group having one or more carbon atoms, and may have two or more, three or more, four or more, five or more, six or more, seven or more, and even eight or more carbon atoms, and at the same time, generally has twenty or less, eighteen or less, sixteen or less, fourteen or less, twelve or less, ten or less, eight or less, six or less, four or less, and even two or less carbon atoms). Examples of suitable R 1 groups include methyl, ethyl, phenyl, and 3,3,3-trifluoropropyl groups. Preferably, R 1 is a methyl group.

[0021] R 2 is, independently at each occurrence, a mercaptoalkyl group. The "mercaptoalkyl group" refers to a -R-SH group (wherein R has a divalent hydrocarbon, preferably having one or more, preferably two or more hydrocarbons, and can have three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, ten or more, twelve or more, fourteen or more, sixteen or more, and even eighteen or more carbon atoms, and at the same time, generally has twenty or less, or even eighteen or less, sixteen or less, fourteen or less, twelve or less, ten or less, eight or less, six or less, four or less, and even two or less carbon atoms). The R group may be linear or branched. For example, R 2 can be selected from -CH2SH, -CH2CH2SH, -CH2(CH2)2SH, and -CH2(CH2)3SH.

[0022] R 3 is, independently at each occurrence, selected from the options of R 1 [[ID=​​​

[0023] The subscript m has an average value of 2 or more, and may be 3 or more, 4 or more, 5 or more, 10 or more, 20 or more, 30 or more, 40 or more, 50 or more, 60 or more, 70 or more, 80 or more, 90 or more, 100 or more, 200 or more, 300 or more, 400 or more, and even 500 or more, and at the same time is generally 1000 or less, 750 or less, 500 or less, 250 or less, 100 or less, 75 or less, 50 or less, 20 or less, 15 or less, 10 or less, 8 or less, and even 6 or less.

[0024] The subscript n has an average value of 0 or greater, 1 or greater, and may be 5 or greater, 10 or greater, 15 or greater, 20 or greater, 25 or greater, 30 or greater, 35 or greater, 40 or greater, 43 or greater, 45 or greater, and may also be 50 or greater, 100 or greater, 200 or greater, 300 or greater, 400 or greater, and may also be 500 or greater, and at the same time, it is generally 1000 or less, 750 or less, 500 or less, 250 or less, 100 or less, 90 or less, 80 or less, 70 or less, 60 or less, 50 or less, and may also be 45 or less.

[0025] One preferred first organopolysiloxane is R 1 is methyl, R 2 The molecule has the chemical structure of formula (I), where -CH2(CH2)2SH, the average value of m is 5, and the average value of n is 43.

[0026] Preferably, the first organopolysiloxane is present in a concentration sufficient to provide a molar ratio of 0.3 or more, 0.5 or more, 1.0 or more, 1.5 or more, 2.0 or more, 2.5 or more, 3.0 or more, 3.5 or more, 4.0 or more, and even 4.5 or more, while simultaneously being approximately 5.0 or less, 4.5 or less, 4.0 or less, 3.5 or less, 3.0 or less, 2.5 or less, 2.0 or less, 1.5 or less, and even 1.0 or less, for the mercaptoalkyl group to the alkenyl group. The molar ratio of mercaptoalkyl group to alkenyl group is determined from the components and formulation used to prepare the composition. If the formulation is unknown, infrared spectroscopy, Raman spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy are used to determine the molar ratio of mercaptoalkyl groups to alkenyl groups.

[0027] The composition of the present invention also includes a second organopolysiloxane. The second organopolysiloxane contains, on average, one or more alkenyl groups per molecule, and may contain two or more, three or more, four or more, five or more, and even six or more alkenyl groups, and generally contains 20 or fewer, 15 or fewer, 10 or fewer, and even 5 or fewer, 4 or fewer, 3 or fewer, or 2 or fewer alkenyl groups. The average number of alkenyl groups per molecule is determined from the material used as the second organopolysiloxane in the preparation of the composition. If the formulation is unknown, the average number of alkenyl groups per molecule is determined using NMR spectroscopy. Preferably, the alkenyl groups are terminal alkenyl groups, meaning that the carbon-carbon double bond (C=C) of the alkenyl group contains the terminal carbon of the alkenyl group. Preferably, the alkenyl groups are vinyl groups.

[0028] The second organopolysiloxane also contains, on average, one or more hydrolyzable groups per molecule, and may contain two or more, three or more, four or more, five or more, or even six or more hydrolyzable groups, and generally contains 20 or fewer, 15 or fewer, 10 or fewer, or even 5 or fewer, 4 or fewer, 3 or fewer, or 2 or fewer hydrolyzable groups. Determine the average number of hydrolyzable groups per molecule from the material used as the second organopolysiloxane in the preparation of the composition. If the formulation is unknown, determine the average number of hydrolyzable groups per molecule using NMR spectroscopy. The hydrolyzable groups are preferably alkoxy groups, preferably with the following chemical structure: -OR 3 (In the formula, R 3 The alkoxy group has one or more, two or more, three or more, four or more, five or more, six or more, seven or more, and even eight or more carbon atoms, and at the same time is an alkyl group that typically has 10 or fewer, eight or fewer, six or fewer, four or fewer, and even two or fewer carbon atoms. Preferably, the alkoxy group is selected from methoxy, ethoxy, and propoxy groups, and more preferably the alkoxy group is a methoxy group. Preferably, the hydrolyzable group is bonded to a silicon atom of the M-type and / or D-type siloxane unit in the second organopolysiloxane.

[0029] The second organopolysiloxane may contain any combination of M-type, D-type, T-type, and Q-type siloxane units. Preferably, the second organopolysiloxane has chemical structure (II): [ka] (In the formula, R a In each occurrence, the alkyl and aryl groups are independently selected. B is selected from alkenyl, alkoxy, and alkoxy-containing groups so that, in each instance, independently, one or more alkenyl groups and one or more alkoxy groups are obtained per molecule on average. x, on average, is a value greater than or equal to 0 and less than or equal to 10. The sum of y and y' is, on average, 20 or greater and 1000 or less. z, on average, has a value of 2 or greater and at the same time not exceeding 20.

[0030] One preferred second organopolysiloxane has the average chemical structure of chemical structure (III): [ka] (In the formula, the subscripts a and b independently represent values ​​of 10 or greater, 15 or greater, 20 or greater, 25 or greater, 30 or greater, 45 or greater, 60 or greater, 100 or greater, and even 500 or greater, and simultaneously represent values ​​of approximately 200 or less, 100 or less, 50 or less, 45 or less, 40 or less, 35 or less, and even 30 or less.)

[0031] The composition of the present invention may further contain a third organopolysiloxane. The third organopolysiloxane has two or more, three or more, four or more, five or more, and even six or more alkenyl groups per molecule, and generally contains 20 or fewer, 15 or fewer, 10 or fewer, and even 5 or fewer, 4 or fewer, 3 or fewer, or 2 or fewer alkenyl groups. The average number of alkenyl groups per molecule is determined from the material used as the third organopolysiloxane in the preparation of the composition. If the formulation is unknown, the average number of alkenyl groups per molecule is determined using NMR spectroscopy. Preferably, the alkenyl groups are terminal alkenyl groups. Preferably, the alkenyl groups are vinyl groups.

[0032] The third polyorganosiloxane preferably consists of M-type and D-type siloxane units. An example of a suitable third organopolysiloxane has the chemical structure (IV): [ka] (In the formula, "Vi" refers to the vinyl group, and the subscript d has a value of approximately 100 or more, 150 or more, 200 or more, 250 or more, 300 or more, 350 or more, 400 or more, 450 or more, 500 or more, 550 or more, 600 or more, 650 or more, 700 or more, and more often 750 or more, or 760 or more, and at the same time typically has a value of 1000 or less, 950 or less, 900 or less, 850 or less, and more often 800 or less, or 775 or less).

[0033] The third organopolysiloxane may be present in the composition at concentrations of 0% by weight (W%) or more, 10% by weight or more, 20% by weight or more, 30% by weight or more, 40% by weight or more, 50% by weight or more, 60% by weight or more, and even 70% by weight or more, and at the same time, it is typically present at concentrations of 80% by weight or less, 70% by weight or less, 60% by weight or less, 50% by weight or less, 40% by weight or less, 30% by weight or less, 20% by weight or less, and even 10% by weight or less, where W% is relative to the total weight of the second and third organopolysiloxanes.

[0034] The compositions of the present invention further comprise a bisacylphosphine oxide photoinitiator. Surprisingly and unexpectedly, the present invention has found that using a bisacylphosphine oxide as a photoinitiator provides storage stability superior to that of similar compositions without a bisacylphosphine oxide photoinitiator. Examples of suitable bisacylphosphine oxide photoinitiators include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-(2,4,4-trimethylpentyl)phenylphosphine oxide.

[0035] Bisacylphosphine oxide may be the sole photoinitiator in the composition, or additional photoinitiators may be present. Examples of additional photoinitiators include any one or more combinations selected from hydroxyacetophenone, aminoacetophenone, phosphine oxide, benzophenone, substituted benzophenone, and thioxanthone. Particularly preferred additional photoinitiators include 2-hydroxy-2-methyl-1-phenyl-1-propanone, ethyl(2,4,6-trimethylbenzoyl)phenylphosphineate; 2,2-dimethoxy-1,2-diphenylethane-1-one; 2,2-diethoxyacetophenone; and 1-hydroxycyclohexylphenyl ketone. Particularly preferred additional photoinitiators are liquid photoinitiators, which can be used as carrier liquids in the composition. Examples of suitable liquid photoinitiators include 2-hydroxy-2-methylpropiophenone, ethyl(2,4,6-trimethylbenzoyl)phenylphosphine, and 2,2-diethoxyacetophenone.

[0036] The bisacylphosphine oxide photoinitiator, in combination with any additional photoinitiator, is preferably present at a concentration of 0.01% by weight (Wt%) or more, 0.1% by weight or more, 0.5% by weight or more, 1.0% by weight or more, 2.0% by weight or more, 3.0% by weight or more, and even 4.0% by weight or more, based on the weight of the composition, and at the same time, it may be approximately 5.0% by weight or less, 4.0% by weight or less, 3.0% by weight or less, 2.0% by weight or less, and even 1.0% by weight or less. Preferably, the bisacylphosphine oxide is 5% or more by weight, 10% or more by weight, 20% or more by weight, 40% or more by weight, 50% or more by weight, 60% or more by weight, 70% or more by weight, 80% or more by weight, and even 90% or more by weight, based on the total weight of the photoinitiator in the composition, and at the same time, it may be 100% or less by weight, 90% or less by weight, 80% or less by weight, 70% or less by weight, 60% or less by weight, 50% or less by weight, 40% or less by weight, 30% or less by weight, and even 20% or less by weight.

[0037] The composition optionally includes a carrier fluid. The carrier liquid is desirable because it can help compatibilize the bisacylphosphine oxide with the organopolysiloxane component of the composition, thereby enabling the formation of a homogeneous composition. Generally, the bisacylphosphine oxide photoinitiator is mixed with the carrier liquid before mixing with the organopolysiloxane component when preparing the compositions of the present invention. The carrier liquid may be a liquid photoinitiator or may contain a liquid photoinitiator. Examples of liquid photoinitiators that can serve as carrier liquids include 2-hydroxy-2-methylpropiophenone, ethyl(2,4,6-trimethylbenzoyl)phenylphosphine, and 2,2-diethoxyacetophenone. Similarly, the carrier fluid may contain, or consist of, one or more non-photoinitiator liquids, such as silanes including methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, and phenylmethyldimethoxysilane. The liquid carrier may contain or consist of one or more nonpolar organic liquids, such as toluene.

[0038] The carrier liquid is present in the composition at a concentration of 0% by weight or more, based on the weight of the composition, and is present at concentrations of 0.005% by weight or more, 0.01% by weight or more, 0.05% by weight or more, 0.10% by weight or more, 0.25% by weight or more, 0.50% by weight or more, 0.75% by weight or more, 1.0% by weight or more, 1.5% by weight or more, 2.0% by weight or more, 2.5% by weight or more, 3.0% by weight or more, 3.5% by weight or more, and 4.0% by weight or more. It may be present at concentrations of 4.5% by weight or more, and at the same time typically at concentrations of 5.0% by weight or less, 4.5% by weight or less, 4.0% by weight or less, 3.5% by weight or less, 3.0% by weight or less, 2.5% by weight or less, 2.0% by weight or less, 1.5% by weight or less, 1.0% by weight or less, 0.50% by weight or less, 0.25% by weight or less, 1.0% by weight or less, 0.05% by weight or less, or even 0.01% by weight.

[0039] The composition includes a condensation catalyst. The condensation catalyst is typically a titanate, tin, or zirconium-based catalyst. Examples of suitable condensation catalysts include any combination of one or more condensation catalysts selected from the group consisting of: tetraisopropyl orthotitanate, titanium(IV)n-butoxide, titanium(IV)t-butoxide, titanium(IV), titanium di(isopropoxy)bis(ethylacetacetate), tetrakis(trimethylsiloxy)titanium; titanium di(isopropoxy)bis(methylacetacetate), zirconium(IV) isopropoxide, zirconium(IV)n-butoxide, zirconium(IV)t-butoxide, zirconium di(isopropoxy)bis(ethylacetacetate), zirconium di(isopropoxy)bis(methylacetacetate), zirconium di(isopropoxy)bis(acetylacetonate), dimethyltin dineodecanoate, dibutyltin dilaurate, dibutyltin dioctoate, and stannous octoate.

[0040] Typically, the concentration of the condensation catalyst is 0.01% by weight or more, 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1.0% by weight or more, 1.5% by weight or more, 2.0% by weight or more, and even 3.0% by weight or more, relative to the weight of the composition, and at the same time, generally 5.0% by weight or less, 4.0% by weight or less, 3.0% by weight or less, 2.0% by weight or less, or even 1.0% by weight or less.

[0041] The composition comprises a silane having an average of two or more hydrolyzable groups per molecule. The silane functions as a crosslinking agent. It can also function as a carrier liquid and / or reactive diluent. Preferably, the hydrolyzable group is an alkoxy group, and more preferably, the hydrolyzable group is an alkoxy group selected from the group consisting of methoxy, ethoxy, propoxy, and butoxy. The silane may be a dialkoxysilane, a trialkoxysilane, or a combination of a dialkoxysilane and a trialkoxysilane. Most preferably, the silane is a trialkoxysilane.

[0042] The silane preferably has the following structure: [ka] (In the formula, the subscript f is 1, 2, or 3 (preferably 1 or 2, most preferably 1), R 3 (Each occurrence is independently selected from the group consisting of methyl, ethyl, propyl, and butyl groups). Examples of suitable silane compounds include any one or more combinations selected from methyltrimethoxysilane, ethyltriethoxysilane, and dimethyldimethoxysilane.

[0043] The compositions of the present invention may contain 0.05% or more, 0.5% or more, 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, and even 10% or more by weight of an alkoxysilane compound, and at the same time typically contain 20% or less by weight, 19% or less by weight, 18% or less by weight, 17% or less by weight, 16% or less by weight, 15% or less by weight, 14% or less by weight, 13% or less by weight, 12% or less by weight, 11% or less by weight, or 10% or less by weight of an alkoxysilane compound.

[0044] The composition further comprises radical scavengers (inhibitors) to help inhibit radical reactions during storage and increase the storage stability of the composition. Examples of preferred radical scavengers include butylated hydroxytoluene (BHT), 4-methoxyphenol, and any one or more combinations of tert-butylhydroquinone, 6-tert-butyl-2,4-xylenol, 2-tert-butyl-1,4-benzoquinone, 4-tert-butylpyrocatechol, 2,6-di-tert-butylphenol, and N-nitroso-N-phenylhydroxyamine aluminum salts. Radical scavengers are typically present at concentrations of 0.001% by weight or more, 0.005% by weight or more, 0.01% by weight or more, 0.05% by weight or more, 0.10% by weight or more, 0.50% by weight or more, 1.0% by weight or more, and even 1.5% by weight or more, based on the weight of the composition, and at the same time, they are typically present at concentrations of 2.0% by weight or less, 1.5% by weight or less, 1.0% by weight or less, and even 0.5% by weight or less.

[0045] The composition may contain additional components such as fillers. Suitable examples of fillers include silica such as fumed silica and quartz. The filler may be present at concentrations of 0% by weight or more, 1% by weight or more, 5% by weight or more, 10% by weight or more, 15% by weight or more, and even 20% by weight or more, and at the same time, typically at concentrations of 30% by weight or less, 20% by weight or less, 10% by weight or less, or even 5% by weight or less, where the weight percentage is relative to the weight of the composition. [Examples]

[0046] Table 1 lists the components to be used in the following examples. [Table 1] IRGANOX is a trademark of BASF SE Company. OMNIRAD is a trademark of IGM Group BV. XIAMETER is a trademark of Dow Corning Corporation. TYZOR is a trademark of EIDuPont De Nemours and Company.

[0047] procedure Aging. To age the sample, package the sample in a 30 ml (mL) EFD syringe barrel, centrifuge the sample in the syringe, then degas it by pressing the plunger to expel the air, and then seal the syringe in a vacuum-sealed aluminum bag to eliminate moisture and light. Place the bag containing the sample in a preheated 55°C oven for 21 days.

[0048] Measurement of UV curing depth. The sample is packed into a 2.54 mm diameter × 20 mm deep cavity of a polytetrafluoroethylene block. The UV curing depth of the sample is then determined by exposing the sample to UVA and UVB light at doses of 300 milliwatts per square centimeter and 2 joules per square centimeter using a mercury lamp and a Colight UV apparatus. The sample material is removed from the polytetrafluoroethylene block, the uncured sample is wiped off, and the thickness of the solid cured sample is measured using a ruler to determine the depth to which the sample has cured.

[0049] Moisture curing time required to become "non-tacky". A 1.27 mm (50 mil) thick sample film is pulled out onto an FR4 board. The film is moisture-cured by placing it in a dark room at 22°C and 35-42% relative humidity until the surface becomes non-tacky. The surface is evaluated as "non-tacky" by wiping it with a finger covered with a nitrile glove. If the sample does not transfer to the nitrile glove after wiping the surface, the sample is considered "non-tacky".

[0050] Viscosity measurement. The viscosity of the sample composition is determined using a Brookfield cone-plate viscometer (model HBDVII+P) with a cone spindle CPA-52Z compliant with ASTM D-1084 at 23 ± 2°C. The viscosity of organopolysiloxanes is determined using a Brookfield DV1 viscometer according to ASTM D-1084 at 23 ± 2°C.

[0051] Sample preparation Prepare the sample using the components identified in Table 2. Combine the first, second, and third organopolysiloxanes and the filler in a 100 mL dental cup. Mix using a Dental Laboratory Mixer at 1000 RPM for 20 seconds, then at 2000 RPM for 45 seconds to form the initial mixture. Separately, pre-mix the silane with the radical scavenger and add it to the initial mixture, mixing at 2000 RPM for 30 seconds. If used, add the photoinitiator pre-mixed with the carrier liquid and the condensation catalyst, and mix at 2000 RPM for 30 seconds. Package the sample in a 30 mL EFD syringe barrel, centrifuge the sample in the syringe, and then degas it by pressing the plunger to expel the air. For characterizing "fresh" samples, use the sample at this point in preparation. To characterize "aged" samples, vacuum package the syringe in an aluminum bag and age it as described in the "aging" procedure above.

[0052] Table 2 shows the formulation and characterization results of the samples. The amount of each component in the formulation is reported in grams. Comparative examples (Comp Ex) and examples (Ex) are described.

[0053] result The results in Table 2 reveal that the composition achieves the following three objectives only when a bisacylphosphine oxide photoinitiator is present: (1) The viscosity increase is less than twice the fresh viscosity when measured according to ASTM D-1084 using a Brookfield DVII+P viscometer with a cone spindle CPA-52Z at -23+ / -2℃, and (2) 2 joules per square centimeter (J / cm²) 2 When exposed to UVA and UVB irradiation, it achieves a curing depth of at least 70%, preferably 80% or more, and more preferably 90% or more compared to a newly prepared identical composition, and furthermore, it achieves a curing depth of at least 8 millimeters before and after aging, and (3) Allow a moisture-curing non-stick time of 24 hours or less to occur.

[0054] These results apply to various titanate catalysts. This also applies when using a nonpolar carrier liquid (toluene) or a liquid photoinitiator (photoinitiator 1) as the carrier liquid. The data further demonstrate that the photoinitiator should be a bisacylphosphine oxide, and that similar monoacylphosphine oxide photoinitiators (photoinitiator 2) do not achieve the same results. See, for example, Comparative Examples B and E. [Table 2] The present invention may provide the following embodiments. [1] A binary curing organopolysiloxane composition, a. A first organopolysiloxane containing an average of two or more mercaptoalkyl groups per molecule and not containing alkenyl functional groups, b. A second organopolysiloxane containing, on average, one or more alkenyl groups and, on average, one or more hydrolyzable groups per molecule, c. Optionally, a third organopolysiloxane having at least two alkenyl groups per molecule and not containing alkoxy groups, d. Bisacylphosphine oxide photoinitiator, e. Optionally, a carrier liquid and f. Condensation catalyst and, g. Silanes having an average of 2 or more hydrolyzable groups per molecule, h. A radical scavenger in a concentration ranging from 0.001 to 2 weight percent relative to the weight of the composition, A composition containing the following: [2] The composition according to [1] above, further comprising a liquid photoinitiator. [3] The composition according to [1] or 2 above, wherein the first organopolysiloxane has the following average chemical structure:

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[10] The composition according to any one of the above [1] to [9], wherein the second organopolysiloxane has the following structure:

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Claims

1. A binary curing organopolysiloxane composition, a. A first organopolysiloxane containing an average of two or more mercaptoalkyl groups per molecule and not containing alkenyl functional groups, b. A second organopolysiloxane containing, on average, one or more alkenyl groups and, on average, one or more hydrolyzable groups per molecule, c. Optionally, a third organopolysiloxane having at least two alkenyl groups per molecule and not containing alkoxy groups, d. Bisacylphosphine oxide photoinitiator, e. Optionally, a carrier liquid and f. Condensation catalyst and, g. A silane having an average of two or more hydrolyzable groups per molecule, h. A radical scavenger in a concentration ranging from 0.001 to 2 weight percent relative to the weight of the composition, Includes, The first organopolysiloxane has the following average chemical structure: 【Chemistry 1】 (In the formula, R1 is a hydrocarbyl or substituted hydrocarbyl group having 1 to 20 carbon atoms, independently in each instance. R2 is independently a mercaptoalkyl group in each instance. R3 is selected independently each time it appears, from the options of R1 and R2. The subscript m has an average value in the range of 2 to 1000. (The subscript n has an average value in the range of 0 to 1000.) The second organopolysiloxane has the following structure: 【Chemistry 2】 (In the formula, Ra is independently selected from alkyl and aryl groups in each appearance. B is selected from alkenyl, alkoxy, and alkoxy-containing groups such that, in each instance, independently, one or more alkenyl groups and one or more alkoxy groups are obtained per molecule on average. x, on average, is a value greater than or equal to 0 and less than or equal to 10. The sum of y and y' is, on average, 20 or greater and 1000 or less. (On average, z has a value of 2 or greater and 20 or less.) The concentration of the first organopolysiloxane is sufficient to provide a molar ratio of mercaptoalkyl groups from the first organopolysiloxane to alkenyl groups from the second organopolysiloxane and, if present, the third organopolysiloxane, that is 0.3 or more and 5.0 or less. The third organopolysiloxane is in an amount of 0% or more and 80% or less by weight relative to the total weight of the second and third organopolysiloxanes. The bisacylphosphine oxide photoinitiator, in combination with any additional photoinitiator, is present in an amount of 0.01% by weight or more and 5.0% by weight or less of the weight of the composition. The bisacylphosphine oxide is present in an amount of 5% or more and 100% or less by weight based on the total weight of the photoinitiator in the composition. The concentration of the condensation catalyst is 0.01% by weight or more and 5.0% by weight or less relative to the weight of the composition. The composition contains, based on the weight of the composition, 0.05% by weight or more and 20% by weight or less of an alkoxysilane compound.

2. The composition according to claim 1, further comprising a liquid photoinitiator.

3. The composition according to claim 1 or 2, wherein the first organopolysiloxane does not contain an alkoxy functional group.

4. The composition according to any one of claims 1 to 3, wherein the concentration of the titanate condensation catalyst is 0.01% by weight or more and 5% by weight or less relative to the weight of the composition.

5. The composition according to any one of claims 1 to 4, wherein the bisacylphosphine oxide photoinitiator is bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

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