Silicone pressure sensitive adhesive composition and article comprising the same

Abstract

The present invention relates to a silicone pressure sensitive adhesive composition comprising a boron-containing additive comprising a boron-containing compound selected from a cycloboroxane-based compound and a borane-based compound containing a covalent boron-nitrogen bond. The present invention also relates to an article comprising the silicone pressure sensitive adhesive composition, such as a pressure sensitive adhesive tape.

Description

Technical Field

[0001] This invention relates to silicone pressure-sensitive adhesive (PSA) compositions, particularly silicone PSA compositions exhibiting improved adhesion to low-energy surfaces. The invention also relates to articles comprising silicone pressure-sensitive adhesive compositions. Background Technology

[0002] Pressure-sensitive adhesives (PSAs) are widely used in a variety of applications. Among the various types of PSAs, silicone PSAs have attracted increasing attention due to their resistance to extremely high and low temperatures, suitability for both high-energy and low-energy surfaces, and excellent insulating properties. Although silicone PSAs are suitable for low-energy surfaces such as silicone, fluoropolymers, and polyolefin materials, they offer low adhesion on such surfaces without any surface treatment; the adhesion is typically below 300 gf / in when peeled at a 180° angle, as determined by FINAT Test Method No. 1.

[0003] To increase the adhesion of silicone PSAs to such low-energy surfaces, additives such as trialkyl borate (most commonly tri-n-butyl borate) have been incorporated into silicone PSAs. While the addition of trialkyl borate can increase adhesion, the resulting adhesion is still insufficient if added at the dosage conventionally used for PSAs. Adhesion can increase with the amount of trialkyl borate. However, due to its incompatibility with PSAs under high loads, the use of large amounts of trialkyl borate is undesirable.

[0004] Therefore, there remains a need to develop a silicone pressure-sensitive adhesive composition containing alternative additives or additive systems that provide improved adhesion to low-energy surfaces (e.g., silicone, fluoropolymers, and polyolefin materials), particularly at relatively low additive loadings. Summary of the Invention

[0005] In one aspect, the present invention provides an organosilicon pressure-sensitive adhesive composition comprising at least one boron-containing additive, said at least one boron-containing additive comprising a boron-containing compound selected from compounds based on cycloboroxanes and borane-based compounds containing covalent boron-nitrogen bonds.

[0006] In another aspect, the present invention provides an organosilicon pressure-sensitive adhesive composition comprising at least one boron-containing additive, said at least one boron-containing additive comprising at least two members selected from: i) cycloboroxane-based compounds, borane-based compounds containing covalent boron-nitrogen bonds, or cyclic borate esters or salt compounds; ii) boric acid; and iii) acyclic borate ester compounds.

[0007] In another aspect, the present invention provides articles comprising an organosilicon pressure-sensitive adhesive composition according to the above aspects.

[0008] According to the present invention, the silicone pressure-sensitive adhesive composition containing the boron-containing additive provides improved adhesion to low-energy surfaces such as siloxanes, fluoropolymers and polyolefins under the same conditions, compared with the corresponding silicone pressure-sensitive adhesive composition containing conventional trialkyl borate additives. Attached Figure Description

[0009] Figure 1 This is a bar graph showing the peel adhesion force of an adhesive tape measured 20 minutes, 24 hours, and 72 hours after application to silicone rubber, wherein the tape is coated with a pressure-sensitive adhesive composition as described in Example 11, or aged at room temperature and at 40°C for 8 weeks.

[0010] Figure 2 This is a bar graph showing the peel adhesion of silicone pressure-sensitive adhesive compositions containing no additives or containing different amounts of tributyl borate and trimethoxycycloborone.

[0011] Figure 3 The graph shows the peel force of the silicone pressure-sensitive tapes prepared in the reference example and example 23 as a function of time at room temperature.

[0012] Figure 4 The graph shows the peel force of the silicone pressure-sensitive tapes prepared in the reference example and example 23 as a function of time at a temperature of 40°C. Detailed Implementation

[0013] In the description and claims herein, the following terms and expressions shall be understood as indicated.

[0014] The singular forms “a,” “an,” and “the” cover the plural, and references to a specific numerical value include at least that specific value, unless the context clearly specifies otherwise.

[0015] Any and all instances or exemplary language (such as "for example") provided herein are intended only to better illustrate the invention and do not impose a limitation on the scope of the invention, unless otherwise claimed.

[0016] Nothing in the specification should be construed as designating any unrequired element as necessary for the practice of the invention.

[0017] The terms “comprising,” “including,” “containing,” and their grammatical equivalents are inclusive or open-ended terms that do not exclude additional unmentioned elements or methodological steps, but will also be understood to include the more restrictive terms “consisting of” and “substantially consisting of”.

[0018] Except where specified in the working embodiments or elsewhere, all figures representing amounts of material, temperatures, durations, quantitative properties of materials, etc., set forth in the specification and claims shall be understood to be modified by the term “about” in all cases, whether or not the term “about” is used in the description.

[0019] It will be understood that any quantity range referred to herein includes all subranges within that range and any combination of the different endpoints of such ranges or subranges.

[0020] It will also be understood that any compound, material, or substance that is explicitly or implicitly disclosed in the specification and / or referred to in the claims as belonging to a group of compounds, materials, or substances that are related in structure, composition, and / or function includes individual representatives of that group and all combinations thereof.

[0021] As used herein, the term "alkyl" means any monovalent, saturated, straight-chain, or branched hydrocarbon group having up to about 30 carbon atoms, particularly 1 to about 20 carbon atoms, and more particularly 1 to about 10 carbon atoms, and optionally substituted with one or more halogen atoms such as fluorine, chlorine, bromine, and iodine atoms. Illustrative examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl such as n-hexyl, heptyl such as n-heptyl, octyl such as n-octyl, isooctyl, and 2-ethylhexyl, nonyl such as n-nonyl, and decyl such as n-decyl.

[0022] As used herein, the term "alkoxy" refers to a monovalent group -O-alkyl, where the alkyl group is as defined above.

[0023] As used herein, the term "hydroxyalkyl" refers to any alkyl group in which one or more hydrogen atoms have been replaced by the same number of hydroxyl groups (as defined above). Illustrative examples of hydroxyalkyl groups include any alkyl group in which one of the hydrogen atoms bonded to the terminal carbon atom has been replaced by a hydroxyl group (as defined above), such as -alkyl-OH.

[0024] As used herein, the term "alkoxyalkyl" refers to any alkyl group (as defined above) in which one or more hydrogen atoms have been replaced by the same number of alkoxy groups (as defined above). Illustrative examples of alkoxyalkyl groups include any alkyl group (as defined above) in which one of the hydrogen atoms bonded to the terminal carbon atom has been replaced by an alkoxy group, such as -alkyl-O-alkyl.

[0025] As used herein, the term "aryl" refers to any monovalent aromatic hydrocarbon group having about 6 to about 30 carbon atoms, particularly about 6 to about 20 carbon atoms, and more particularly about 6 to about 12 carbon atoms, including alkylaryl and arylalkyl groups. Illustrative examples of aryl groups include phenyl, naphthyl, benzyl, phenethyl, o-, m-, and p-tolyl, and xylyl.

[0026] As used herein, the term "divalent linker" refers to any divalent, saturated, straight-chain, or branched hydrocarbon group having at most about 30 carbon atoms, particularly 1 to about 20 carbon atoms, more particularly 2 to about 10 carbon atoms, and optionally containing one or more heteroatoms selected from oxygen, nitrogen, silicon, sulfur, fluorine, chlorine, bromine, and iodine. Illustrative examples of divalent linkers include alkylene, oxyalkylene, and thioalkylene.

[0027] As used herein, the term "cyclic" refers to a compound comprising any molecule having at least three atoms linked together to form a ring (excluding the benzene ring). The ring can be, for example, a ternary to a ten-membered ring, particularly a quaternary to an octary ring, and more particularly a quaternary, pentagonal, hexaternary, septagonal, or octagonal ring.

[0028] As used herein, the term "acyclic" refers to a compound that does not contain a cyclic structure (excluding the phenyl ring). For example, in some embodiments, the acyclic compounds described herein may have a benzyl or phenyl group.

[0029] The viscosities described herein were measured using a Brookfield viscometer at 25°C, unless otherwise stated.

[0030] In one aspect, the present invention provides a silicone pressure-sensitive adhesive composition comprising at least one boron-containing additive. The boron-containing additive comprises a boron-containing compound selected from compounds based on cycloboroxanes and borane-based compounds containing covalent boron-nitrogen bonds.

[0031] As used in this article, "compounds based on cycloboroxanes" refers to compounds having a six-membered ring formed by alternating connections of three boron atoms and three oxygen atoms.

[0032] As used in this article, "borane-based compounds containing covalent boron-nitrogen bonds" refers to compounds containing one boron alkyl group. Organoboron compounds in which a boron alkyl group is directly connected to at least one nitrogen atom via a covalent bond.

[0033] In one embodiment, the cycloboroxane-based compound may have the general formula (I):

[0034]

[0035] Where R1 R 2 and R 3 Each is independently a hydrogen atom; a hydroxyl group; or a monovalent group having up to about 30 carbon atoms, particularly up to about 20 carbon atoms, more particularly up to about 10 carbon atoms, selected from alkyl, alkoxy, hydroxyalkyl, alkoxyalkyl, or -R 8 -N(R 9 (R) 10 ), where R 8 It is a direct bond or a divalent linker, and R 9 and R 10 Each is independently a hydrogen atom, alkyl, hydroxyalkyl, or alkoxyalkyl;

[0036] Preferably, R 1 R 2 and R 3 Each is independently a monovalent group having up to about 20 carbon atoms, selected from alkoxy, alkoxyalkyl, or -R groups. 8 -N(R 9 (R) 10 ), where R 8 It is a direct bond, an alkylene group, or an alkylene group (where the oxygen atom is bonded to the N atom via an alkylene group), and R 9 and R 10 Each is independently a hydrogen atom, an alkyl group, or an alkoxyalkyl group; and more preferably a monovalent group selected from those having at most about 10 carbon atoms, particularly 1 to about 8 carbon atoms, more particularly 1 to about 6 carbon atoms, or -R 8 -N(R 9 (R) 10 ), where R 8 It is a direct bond or an alkylene oxide having about 2 to about 6 carbon atoms, and R 9 and R 10 Each is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyalkyl group having 2 to 8 carbon atoms.

[0037] In a preferred embodiment, the cycloboroxane-based compound may have the general formula (I-1):

[0038]

[0039] Where R 11 R 12 and R 13 Each is an independent monovalent group having up to about 20 carbon atoms, selected from alkyl or -R groups. 14 -N(R 15 (R) 16 ), where R 14It is an alkylene group, and R 15 and R 16 Each is independently a hydrogen atom, an alkyl group, or an alkoxyalkyl group; and preferably, R 11 R 12 and R 13 Each is independently an alkyl group having 1 to about 10 carbon atoms, preferably 1 to about 8 carbon atoms, and more preferably 1 to about 6 carbon atoms.

[0040] In another preferred embodiment, the cycloboroxane-based compound may have the general formula (I-2):

[0041]

[0042] Each R 17 Independently a hydrogen atom, or an alkyl or alkoxyalkyl group having up to 20 carbon atoms; preferably, each R 17 It is independently a hydrogen atom or an alkyl group having up to 10 carbon atoms, preferably 1 to about 8 carbon atoms, and more preferably 1 to about 6 carbon atoms.

[0043] The cycloboroxane-based compounds can be prepared by various methods known in the art. For example, the cycloboroxane-based compounds can be prepared by heating boric acid with substituents to form a cycloboroxane compound having the corresponding substituents on the B atom; or by reacting a triorganoborane with boron oxide to obtain the corresponding cycloboroxane compound. As a further illustrative example, cycloboroxane compounds having formula (I-1) can also be prepared by reacting boric acid with a trialkyl borate in a stoichiometric ratio.

[0044] In another embodiment, the borane-based compound containing a covalent boron-nitrogen bond may have the general formula (II):

[0045]

[0046] Where R 4 and R 5 Each is independently a monovalent group having up to about 30 carbon atoms, particularly up to about 20 carbon atoms, and more particularly up to about 10 carbon atoms, selected from alkyl, alkoxy, hydroxyalkyl, alkoxyalkyl, or -R 8 -N(R 9 (R) 10 ), where R 8 It is a direct bond or a divalent linker, and R 9 and R 10 Each is independently a hydrogen atom, alkyl, hydroxyalkyl, or alkoxyalkyl; preferably, R 4 and R 5Each is an independent monovalent group having up to about 20 carbon atoms, selected from alkoxy or -R groups. 8 -N(R 9 (R) 10 ), where R 8 It is a direct bond or an alkylene bond, and R 9 and R 10 Each is independently a hydrogen atom, an alkyl group, or an alkoxyalkyl group; more preferably, R 4 and R 5 Each is independently an alkoxy group having at most about 10 carbon atoms, particularly 1 to about 8 carbon atoms, more particularly 2 to about 6 carbon atoms, or -R 8 -N(R 9 (R) 10 ), where R 8 It is a direct key, and R 9 and R 10 Each is independently a hydrogen atom or an alkyl group having at most about 10 carbon atoms, particularly 1 to about 8 carbon atoms, and more particularly 1 to about 6 carbon atoms;

[0047] Optional, R 4 and R 5 Together they form a ring containing at most about 10 carbon atoms, preferably about 2 to about 6 carbon atoms, and more preferably about 2 to about 5 carbon atoms, of an alkylene group bonded to a B atom of formula (II) via an oxygen atom; and

[0048] R 6 and R 7 Each is independently an alkyl, hydroxyalkyl, or alkoxyalkyl group, each having at most about 30 carbon atoms, particularly at most about 20 carbon atoms, and more particularly at most about 10 carbon atoms, or hydrogen atoms; preferably, R 6 and R 7 Each is independently a hydrogen atom, or an alkyl group having at most about 10 carbon atoms, particularly 1 to about 8 carbon atoms, and more particularly 1 to about 6 carbon atoms.

[0049] In a preferred embodiment, the borane-based compound containing a covalent boron-nitrogen bond may have the general formula (II-1):

[0050]

[0051] Where R 21 R 22 R 23 R 24 R 25 and R 26Each is independently an alkyl, hydroxyalkyl, or alkoxyalkyl group, each having at most about 20 carbon atoms, or hydrogen atoms; preferably, R 21 R 22 R 23 R 24 R 25 and R 26 Each is independently an alkyl group having at most about 10 carbon atoms, or a hydrogen atom; more preferably an alkyl group having at most about 10 carbon atoms, more preferably 1 to about 8 carbon atoms, and even more preferably 1 to about 6 carbon atoms.

[0052] In another preferred embodiment, the borane-based compound containing a covalent boron-nitrogen bond may have the general formula (II-2):

[0053]

[0054] Where R 27 and R 28 Each is an independent monovalent group having up to 20 carbon atoms, selected from alkyl or -R groups. 31 -N(R 32 (R) 33 ), where R 31 It is an alkylene group, and R 32 and R 33 Each is independently a hydrogen atom, an alkyl group, or an alkoxyalkyl group; preferably, R 27 and R 28 Each is independently an alkyl group having at most 10 carbon atoms, preferably 1 to about 8 carbon atoms, and more preferably 1 to about 6 carbon atoms;

[0055] Optional, R 27 and R 28 Together they form a ring bonded to an alkylene group containing 1 to 6 carbon atoms, preferably about 2 to 6 carbon atoms, and more preferably about 2 to 5 carbon atoms, of the O atom of formula (II-2); preferably, R 27 and R 28 Together they form a ring containing -CH2CH2-, -CH2CH2CH2-, -CH2CH(CH3)-, -CH(CH3)CH(CH3)-, -CH2CH(CH3)CH2-, or -CH2C(CH3)2CH2- bonded to the O atom of formula (II-2); and

[0056] Where R 29 and R 30Each is independently an alkyl, hydroxyalkyl, or alkoxyalkyl group, each having at most 20 carbon atoms or hydrogen atoms; preferably an alkyl group having at most about 10 carbon atoms or hydrogen atoms; more preferably an alkyl group having at most about 10 carbon atoms, more preferably 1 to about 8 carbon atoms, and even more preferably 1 to about 6 carbon atoms.

[0057] The borane-based compounds containing covalent boron-nitrogen bonds can be prepared by various methods known in the art. For example, the covalent boron-nitrogen bonds in borane-based compounds can be introduced by reacting a haloborane with a corresponding secondary amine compound to replace the halogen atom bonded to the boron atom with the corresponding amino group. Furthermore, the boron-oxygen bonds in borane-based compounds having covalent boron-nitrogen bonds can be introduced, for example, by subjecting a tris(dialkylamino)borane compound to an alcohol-amine exchange reaction with an aliphatic alcohol compound. As an illustrative example, borane-based compounds having formula (II-2) can be prepared by reacting tris(dimethylamino)borane with a monohydric alcohol in a stoichiometric ratio to form an acyclic compound, or with an alkylene glycol in a stoichiometric ratio to form a cyclic compound. See Gerrard, W. et al., “Chemistry of Certain Novel Organic Boron Compounds”, Chemistry & Industry, 292-3 (1958), which is incorporated herein by reference in its entirety.

[0058] Based on the total weight of the silicone pressure-sensitive adhesive composition, at least one boron-containing additive selected from compounds based on cycloboroxanes and compounds based on boranes may be present in an amount of about 0.01 to about 10% by weight, preferably about 0.05 to about 9% by weight, and more preferably 0.1 to about 8% by weight.

[0059] Compared to conventional trialkyl borate additives under the same conditions, compounds based on cycloboroxanes as defined in Formula (I) above or compounds based on boranes containing covalent boron-nitrogen bonds as defined in Formula (II) above increase the peel adhesion of the silicone pressure-sensitive adhesive compositions of the present invention to silicone rubber by at least about 45%, in some embodiments by about 65% or more, and in further embodiments by about 80% or more, or even 100% or more.

[0060] In other embodiments, the at least one boron-containing additive comprises at least two members selected from the following (hereinafter referred to as the first member and the second member):

[0061] i) Compounds based on cycloboroxanes, borane-based compounds containing covalent boron-nitrogen bonds, or cyclic borate esters or salts;

[0062] ii) Boric acid; and

[0063] iii) Acyclic borate esters.

[0064] As used herein, the term "cyclic borate ester or salt" refers to a cyclic ester or salt of boric acid (H3BO3), alkylboronic acid, or arylboronic acid. As used herein, the terms "alkylboronic acid" and "arylboronic acid" refer to alkyl- and aryl-substituted boric acid compounds in which one of the three hydroxyl groups bonded to a boron atom is respectively substituted by an alkyl group having 1 to about 6 carbon atoms or an aryl group having about 6 to about 12 carbon atoms. Cyclic borate esters or salts may contain one, two, or three rings in a molecule.

[0065] In one embodiment, the cyclic borate ester or salt compound may have the general formula (III):

[0066]

[0067] Where R 34 and R 35 Each is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms; optionally, R 34 and R 35 Together they form a formula containing -OL 3 A ring of divalent groups of -CH2-, wherein -L 3 - The group is bonded to the B atom of formula (III) via an oxygen atom;

[0068] L 1 L 2 and L 3 Each is independently represented by the formula - [C(O)] m C n H 2n - a divalent group, where m is 0 or 1, and n is an integer from 0 to 4, provided that R 34 and R 35 When they form a ring together, for L 1 L 2 and L 3 At least one of the defined m is 0.

[0069] In one embodiment, the cyclic borate ester or salt compound is selected from compounds having formula (III), wherein R 34 and R 35 Each is independently an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms; L 1 and L 2 Each is independently represented by the formula - [C(O)] m C n H 2n- a divalent group, wherein m is 0 or 1, and n is an integer from 0 to 3, provided that m + n is at least 1. Preferably, L 1 and L 2 Each of them is independently a divalent group -CH2-, -CH2CH2-, -CH(CH3)-, -C(CH3)2-, -C(O)-, or -C(O)CH2-.

[0070] In another embodiment, the cyclic borate ester or salt compound may have the general formula (III-1):

[0071]

[0072] Where L 1 and L 2 Each is independently represented by the formula - [C(O)] m C n H 2n - a divalent group, wherein m is 0 or 1, and n is an integer from 0 to 3, provided that m+n is at least 1; preferably, L 1 and L 2 Each of them is independently a divalent group -CH2-, -CH2CH2-, -CH(CH3)-, -C(CH3)2-, -C(O)-, or -C(O)CH2-;

[0073] L 3 It can be -CH2-, -CH2CH2-, -CH(CH3)-, or -C(CH3)2-.

[0074] The cyclic borate esters or salts can be prepared, for example, by reacting boric acid, alkylboronic acid (such as methylboronic acid or ethylboronic acid), or arylboronic acid (such as phenylboronic acid) with an amine compound containing 1-3 hydroxyl groups, one or two carboxyl groups, or combinations thereof. Illustrative examples of such amine compounds include, but are not limited to, tri(hydroxyalkyl)amines, such as triethanolamine, tri-n-propanolamine, or triisopropanolamine; hydroxyalkyliminodicarboxylic acids, such as (2-hydroxyethyl)iminodiacetic acid; and alkyliminodicarboxylic acids, such as N-methyliminodiacetic acid or N-ethyliminodiacetic acid.

[0075] As used herein, the term "acyclic borate ester" refers to an acyclic compound derived from boric acid, typically including trialkyl borate esters well known in the art. The alkyl groups in a trialkyl borate ester may each independently have 1 to about 20 carbon atoms, particularly 1 to about 10 carbon atoms, and more particularly 1 to about 6 carbon atoms. As used herein, the term "trialkyl borate ester" includes both a single trialkyl borate ester and a mixture of trialkyl borate esters with different alkyl groups. Illustrative examples of acyclic borate ester compounds include, but are not limited to, trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, triisobutyl borate, trioctyl borate, trilauryl borate, tristearyl borate, or combinations thereof; preferably, trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, triisobutyl borate, or combinations thereof.

[0076] Acyclic borate esters and boric acids can be collectively referred to as acyclic borate compounds in this article.

[0077] In one embodiment, the boron-containing additive comprises one or more compounds from i) above as a first member and ii) above as a second member; or comprises one or more compounds from i) above as a first member and one or more compounds from iii) above as a second member; or comprises ii) above as a first member and one or more compounds from iii) above as a second member. Illustrative examples of boron-containing additives according to this embodiment include, but are not limited to: a compound based on cycloboroxane of formula (I) as a first member and a trialkyl borate ester as a second member; a compound based on cycloboroxane of formula (I) as a first member and boric acid as a second member; a borane-based compound containing covalent boron-nitrogen bonds of formula (II) as a first member and a trialkyl borate ester as a second member; a borane-based compound containing covalent boron-nitrogen bonds of formula (II) as a first member and boric acid as a second member; boric acid as a first member and a trialkyl borate ester as a second member; a cyclic borate ester or salt as a first member and a trialkyl borate ester as a second member; and a compound based on cycloboroxane of formula (I) and a borane-based compound containing covalent boron-nitrogen bonds of formula (II) as a first member and a trialkyl borate ester as a second member. The boron-containing additive according to this embodiment provides improved adhesion to low-energy surfaces such as silicone, fluoropolymers and polyolefin materials to the silicone pressure-sensitive adhesive composition.

[0078] In one embodiment, the boron-containing additive comprises a compound of formula (I) based on cycloboroxane, a cyclic borate ester or salt compound, boric acid, or a combination thereof as a first member; and an acyclic borate ester compound selected from trialkyl borates as a second member. Illustrative examples of the boron-containing additive according to this embodiment include, but are not limited to: a combination of a compound of formula (I-1) based on cycloboroxane as a first member and a trialkyl borate as a second member; a combination of boric acid as a first member and a trialkyl borate as a second member; and a combination of a cyclic borate ester or salt compound of formula (III) as a first member and a trialkyl borate as a second member. The two members in the boron-containing additive according to this embodiment achieve a synergistic effect in improving the adhesion of silicone pressure-sensitive adhesive compositions to low-energy surfaces such as silicone, fluoropolymers, and polyolefin materials.

[0079] In another embodiment, the boron-containing additive comprises boric acid, a cyclic borate ester or salt compound having formula (III-1), or a combination thereof, as a first member; and an acyclic borate ester compound, particularly a trialkyl borate ester, as a second member. These two members achieve a significant synergistic effect in improving the adhesion of silicone pressure-sensitive adhesive compositions to low-energy surfaces such as silicone, fluoropolymers, and polyolefin materials.

[0080] In another embodiment, the boron-containing additive comprises a cycloboroxane-based compound having formula (I-1) as a first member and a trialkyl borate ester as a second member. These two members achieve a significant synergistic effect in improving the adhesion of the silicone pressure-sensitive adhesive composition to low-energy surfaces such as silicone, fluoropolymers, and polyolefin materials. Furthermore, the silicone pressure-sensitive adhesive composition comprising the boron-containing additive according to this embodiment exhibits a clear appearance and long-term stability.

[0081] The weight ratio of the first member to the second member can vary over a wide range. Typically, the weight ratio (first member: second member) can range from about 1:100 to about 1:1, preferably from about 1:70 to about 1:1. The weight ratio (first member: second member) can be, for example, from about 1:60 to about 1:2, for example, from about 1:50 to about 1:3, or in another embodiment, from about 1:40 to about 1:4.

[0082] In other embodiments, the boron-containing additive may comprise all three members of i), ii), and iii) above. Preferably, the acyclic borate compound iii), particularly trialkyl borate, is present in an amount of about 50% to about 99% by weight, particularly about 60% to about 98% by weight, relative to the total amount of the boron-containing additive.

[0083] In addition to the at least one boron-containing additive, the silicone pressure-sensitive adhesive composition further comprises a silicone pressure-sensitive adhesive (silicone PSA). The silicone PSA can be any known in the art. The silicone PSA typically comprises a polyorganosiloxane compound and a silicone resin; and optionally, may further comprise a curing catalyst, solvent, filler, and other optional components. The pressure-sensitive adhesive composition can be cured by free radical reaction or hydrosilylation reaction.

[0084] As used herein, the term "polyorganosiloxane compound" refers to a polyorganosiloxane with a viscosity of at least about 300,000 cp, particularly about 500,000 cp to about 150,000,000 cp, more particularly about 1,000,000 cp to about 100,000,000 cp, and even more particularly about 2,000,000 cp to about 80,000,000 cp. Polyorganosiloxane compounds may have a number average molecular weight of at least 100,000, particularly about 120,000 to about 1,000,000, and particularly about 150,000 to about 800,000. Polyorganosiloxane compounds may contain one or more functional groups selected from hydroxyl, alkenyl (such as vinyl), alkoxy, alkoxyalkenyl, and hydrogen groups.

[0085] Suitable polyorganosiloxane compounds may have the following general formula:

[0086] R2R F SiO(R2SiO) x (RR F SiO) y SiR F R2(IV)

[0087] Each R is independently a monovalent hydrocarbon group having up to about 12 carbon atoms, such as an alkyl group having 1 to about 6 carbon atoms, such as methyl, ethyl and propyl; or an aryl group having about 6 to about 12 carbon atoms, such as phenyl;

[0088] Each R F Independently hydroxyl, hydrogen, alkenyl such as vinyl, alkoxy or alkoxyalkenyl having 1 to about 10 carbon atoms;

[0089] x and y are independently 0 or at most 10,000 positive numbers, particularly 1 to about 8,000, and even more particularly 10 to about 5,000, provided that x + y is at least 1,000.

[0090] Illustrative examples of polyorganosiloxane compounds include, but are not limited to, hydroxyl-terminated polydimethylsiloxanes and polydimethylsiloxane-polydiphenylsiloxane copolymers, as well as vinyl-functionalized polyorganosiloxanes.

[0091] As used herein, the term "silicone resin" refers to a product containing at least one (RSiO) 3 / 2 ) or (SiO 4 / 2 Any organo-based polysiloxane with a silanoloxy unit. In one embodiment, the silicone resin comprises at least one of the formulas M=R3SiO 1 / 2 The M-element and at least one element selected from the following: Equation T = RSiO 3 / 2 The T unit and the formula Q = SiO 4 / 2 The Q unit, and optionally at least one of the equations D = R 2 SiO 2 / 2 The D unit, wherein each R is independently a monovalent hydrocarbon group of 1 to 6 carbon atoms, such as an alkyl group of 1 to 4 carbon atoms, such as methyl or phenyl.

[0092] There is no limit to the molecular weight of silicone resins and they can vary over a wide range. For example, the number average molecular weight of silicone resins can be about 300 or higher, particularly about 500 to about 50,000, and more particularly about 1,000 to about 30,000.

[0093] In one embodiment, the silicone resin is an MQ resin comprising at least one Q unit and at least one M unit. The ratio of M units to Q units may be, for example, from about 0.5:1 to about 1.5:1, particularly from about 0.6:1 to about 1.2:1, more particularly from about 0.7:1 to about 1.1:1, and even more particularly from about 0.85:1 to about 1.0:1. The MQ resin may further comprise D units, T units, or both, in an amount, for example, 20 mol% or less of the total number of units in the silicone resin, particularly 10 mol% or less, and even more particularly 5 mol% or less.

[0094] Typically, MQ resins can be functionalized with hydroxyl groups. The total hydroxyl content in MQ resins is typically about 1-10% by weight, particularly about 2-8% by weight, and more particularly about 2-5% by weight. MQ resins can also optionally be functionalized with one or more functional groups selected from alkenyl groups such as vinyl, alkoxy, alkoxyalkenyl, and hydrogen groups.

[0095] In another embodiment, the silicone resin is an MT resin comprising at least one T unit and at least one M unit, preferably an MDT resin comprising at least one D unit in addition to the T and M units. The MT and MDT resins may also contain Q units. The amount of T and D units (if present) may be, for example, 60 mol% or more of the total number of units in the silicone resin, particularly 70 mol% or more, and more particularly 80 mol% or more.

[0096] In MT or MDT resins, the molar ratio (R / Si) of the hydrocarbon group "R" to Si atoms is typically from about 1.0:1 to about 1.8:1, particularly from about 1.1:1 to about 1.7:1, and more particularly from about 1.2:1 to about 1.6:1. In illustrative examples, the hydrocarbon group "R" includes methyl and phenyl (Ph), wherein the ratio of phenyl to hydrocarbon group (Ph / R) is, for example, from about 0.1:1 to about 0.8:1, preferably from about 0.2:1 to about 0.7:1, and more preferably from about 0.2:1 to about 0.6:1.

[0097] MT resin or MDT resin may optionally be functionalized with one or more functional groups selected from hydroxyl, alkenyl such as vinyl, alkoxy, alkoxyalkenyl and hydrogen groups.

[0098] Based on 100 parts by weight of the polyorganosiloxane adhesive, the amount of silicone resin present in the silicone resin pressure-sensitive adhesive composition may be from about 50 parts by weight to about 150 parts by weight, particularly from about 70 parts by weight to about 130 parts by weight, and more particularly from about 80 parts by weight to about 120 parts by weight.

[0099] Many suitable silicone pressure-sensitive adhesives comprising both polyorganosiloxane compounds and silicone resins are commercially available. Illustrative examples of these silicone pressure-sensitive adhesives include, but are not limited to, SilGrip from Momentive Performance Materials. TM Series, such as SilGrip TM PSA 5080, PSA 510, PSA 518, PSA 529, PSA590LD, PSA595, PSA610, PSA6573A, PSA6574, PSA810, PSA820 and PSA915.

[0100] The silicone pressure-sensitive adhesive compositions described herein preferably include a curing catalyst to improve their properties, such as cohesive strength, although in some embodiments a catalyst may not be used. There are no particular limitations on the curing catalysts used herein, and they are generally selected based on the curing mechanism of the silicone pressure-sensitive adhesive. For example, if the silicone pressure-sensitive adhesive is cured via a free radical reaction, the curing catalyst may include, for example, peroxides such as inorganic and organic peroxides. Illustrative examples of peroxides include, but are not limited to, aryl peroxides, such as benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and combinations thereof. If the silicone pressure-sensitive adhesive is cured via a hydrosilylation reaction, the curing catalyst may include, for example, noble metal catalysts, such as those using ruthenium, rhodium, palladium, osmium, iridium, and platinum, and complexes of these metals. Illustrative examples of hydrosilylation catalysts include, but are not limited to: Ashby catalysts; Lamoreax catalysts; Karstedt catalysts; Modic catalysts; and Jeram catalysts and combinations thereof.

[0101] Based on 100 parts by weight of the polyorganosiloxane compound, the amount of curing catalyst present may be up to about 10 parts by weight, preferably about 0.1 to about 8 parts by weight, and more preferably about 0.5 to about 5 parts by weight.

[0102] Suitable solvents may be included to adjust the viscosity of the silicone pressure-sensitive adhesive composition, although solvent-free silicone pressure-sensitive adhesives are also suitable herein. Illustrative examples of solvents include, but are not limited to, aromatic solvents such as toluene and xylene, aliphatic solvents such as hexane, octane, and isoparaffins, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and isobutyl acetate, and ethers such as diisopropyl ether and 1,4-dioxane, or combinations thereof. The amount of solvent generally depends on the viscosity of the adhesive and the apparatus (means) used to apply the silicone pressure-sensitive adhesive composition. As an illustrative example, a solvent included in an amount of about 40 wt% to 70 wt% will provide the solution with a viscosity suitable for coating. The solvent may be removed at a relatively low temperature during a drying step prior to curing the silicone PSA composition.

[0103] Illustrative examples of fillers may include, but are not limited to, quartz powder, zinc oxide, aluminum hydroxide, titanium dioxide, light calcium carbonate, or combinations thereof, to increase cohesive strength and reduce cost. The amount of filler can vary over a wide range depending on the organosilicon PSA, the nature of the filler, and the intended use. For example, based on 100 parts by weight of polyorganosiloxane compound, the filler may be present in an amount from 0 to about 150 parts by weight, and preferably from about 1 to about 100 parts by weight.

[0104] Other optional components may include, for example, condensation accelerators for promoting the condensation reaction of silanol groups, such as dibutyltin diacetate; non-reactive polyorganosiloxanes, such as polydimethylsiloxane and silsesquioxane resins; antioxidants, such as phenolic, quinone, amine, phosphorus, phosphite, sulfur, and thioether antioxidants; light stabilizers, such as triazole and benzophenone light stabilizers; flame retardants, such as phosphate, halogen, phosphorus, and antimony flame retardants; and dyes and pigments.

[0105] Some optional additives are commercially available. Illustrative examples of commercial additives include, but are not limited to, anchoring promoters for improving the adhesion of silicone PSAs to substrates, such as AnchorSil. TM 2000, SilForce TM SL6020 or especially SilForce for polyester substrates TM SS4300C or SilQuest TM A-186 silane; and silicone resin additives for controlling tacking, such as SilGrip. TM SR500 resin and SR545 resin, both of which are available from Momentive Performance Materials.

[0106] The silicone pressure-sensitive adhesive compositions described herein can have improved peel adhesion to low-energy surfaces such as silicone, fluoropolymers, and polyolefins. In one embodiment, the low-energy surface herein can be silicone rubber. The adhesion to silicone rubber, measured by peel at a 180-degree angle according to FINAT test method No. 1, can be at least about 660 gf / inch, preferably about 700 gf / inch to about 1500 gf / inch, more preferably about 800 gf / inch to about 1400 gf / inch, and even more preferably about 1000 gf / inch to about 1300 gf / inch.

[0107] The silicone pressure-sensitive adhesive composition according to the invention can be prepared by a method comprising mixing the at least one boron-containing additive with a polyorganosiloxane compound and a silicone resin, and optionally any of the optional components described above and herein, such as a curing catalyst, solvent, filler, and other additives. Mixing can be carried out at room temperature or at elevated temperatures not exceeding about 50°C (e.g., about 30°C to about 45°C) for a time (e.g., seconds to hours) to effectively obtain a homogeneous mixture. When two or more boron-containing additives are used, they can be added together or separately. The components to be mixed can be added in any order. For example, in one embodiment, the boron-containing additive can be added together with or separately from the curing catalyst to a dispersion of the polyorganosiloxane compound and silicone resin, with or without a solvent; and can be mixed with the polyorganosiloxane compound, and then the silicone resin and curing catalyst can be added thereto simultaneously or sequentially, with or without a solvent. In a specific embodiment, the method for preparing the adhesive composition includes dispersing a polyorganosiloxane adhesive and an organosilicon resin in a solvent, preferably an organic solvent, such as toluene, xylene, heptane, or a combination thereof; and adding a boron-containing additive and a curing catalyst, optionally together with fillers or other additives, to the dispersion.

[0108] On the other hand, the present invention provides articles comprising, for example, pressure-sensitive tapes, the silicone pressure-sensitive adhesive compositions described herein. Pressure-sensitive tapes can be prepared by applying the silicone pressure-sensitive adhesive composition to a substrate, such as a rigid substrate or a flexible substrate, such as a polymer substrate. Illustrative examples of polymer substrates include, but are not limited to, polyester substrates, such as polyethylene terephthalate or polybutylene terephthalate substrates. The substrate can be used as is. Alternatively, the substrate can be pretreated, for example by corona treatment; or coated with a primer, such as SilForce from Momentive Performance Materials. TM SS4191A and SilForce TM SS6800.

[0109] Because the silicone pressure-sensitive adhesive composition described herein has improved adhesion to low-energy surfaces such as silicone, fluoropolymers, and polyolefins, pressure-sensitive tapes containing this composition can be widely used in adhesive materials with low-energy surfaces, particularly for the adhesion of silicone materials. Therefore, the present invention further relates to articles comprising the silicone pressure-sensitive adhesive composition described herein on low-energy surfaces such as silicone, fluoropolymers, and polyolefins, particularly on silicone rubber.

[0110] Example

[0111] The invention will be explained in more detail with reference to the embodiments, but these examples should not be construed as limiting the scope of the invention. In the following description, "parts" and "%" mean "parts by weight" and "% by weight" unless otherwise stated. Furthermore, all viscosities are measured using a Brinell rotational viscometer at 25°C and reported in centipoises (cp) unless otherwise stated.

[0112] Preparation Example 1 - Synthesis of Dimethyldibutoxyborane Amine

[0113]

[0114] In a fume hood, tris(dimethylamino)borane (1.00 g, 0.007 mol, Sigma-Aldrich) and n-BuOH (1.04 g, 0.014 mol) were added to a 25 mL flask at room temperature. After shaking, gas was produced and escaped from the flask. The reaction continued for approximately one day until no more gas was released. A clear liquid was obtained and set aside for use.

[0115] Preparation Example 2 - Synthesis of dimethyldioxaneborylamine

[0116]

[0117] In a fume hood, tris(dimethylamino)borane (1.00 g, 0.007 mol, Sigma-Aldrich) and ethylene glycol (0.43 g, 0.007 mol) were added to a 25 mL flask at room temperature. After shaking, a gas was produced and escaped from the flask. The reaction continued for about one day until no more gas was released. A white solid was obtained and set aside.

[0118] Preparation Example 3 - Synthesis of Tetraacetyl Diborate

[0119]

[0120] Acetic anhydride (24.4 g, 0.24 mol, Sinopharm) and boric acid (4.8 g, 0.08 mol, Sinopharm) were added to a 100 mL three-necked flask equipped with a mechanical stirrer and thermocouple. The temperature was slowly increased to 59 °C using a hot water bath. After removing the hot water bath, the temperature continued to spontaneously rise from 59 °C to 60.5 °C over approximately 10 minutes. The temperature was then immediately reduced to 55 °C using a cold water bath. The reaction was stabilized at 59–60 °C and refluxed for 1 hour to complete the reaction.

[0121] The result was cooled to 5°C, filtered under vacuum, and washed with a 1:1 mixture of heptane and ethyl acetate. After drying in an oven at 40°C, the product was obtained in a yield of approximately 5 g.

[0122] The boron-containing compounds used in the following examples are listed in Table 1 below.

[0123] Table 1: Boron-containing compounds

[0124]

[0125]

[0126]

[0127] General procedure for preparing silicone pressure-sensitive adhesive compositions

[0128] The amounts of boron-containing additive, 1.5 parts by weight of benzoyl peroxide, and 1.2 parts by weight of SR545 silicone resin additive (from Momentive Performance Materials) shown in the following examples were uniformly dispersed in 100 parts by weight (dry weight) of SilGrip. TM PSA610 (from Momentive Performance Materials) silicone pressure-sensitive adhesive was dissolved in toluene to obtain a silicone pressure-sensitive adhesive composition.

[0129] General procedure for preparing silicone pressure-sensitive tape

[0130] A silicone pressure-sensitive adhesive composition with a solids content of 40% was applied to a substrate pre-coated with SilForce. TM A silicone pressure-sensitive adhesive tape was obtained by drying a 25 μm PET film of SS4191A primer (from Momentive Performance Materials) at 85°C for 2 minutes and then curing it at 170°C for 2 minutes. The thickness of the dried and cured adhesive composition on the tape was 25 μm.

[0131] Test method for peel adhesion (180 degrees) of silicone rubber

[0132] Peel adhesion (180 degrees) was measured at 50% relative humidity and 25°C according to FINAT Test Method No. 1. A 25 mm (1 inch) wide silicone pressure-sensitive tape was attached to vulcanized silicone rubber LSR2640 (from MomentivePerformance Materials) and rolled back and forth once with a 2 kg roller at a speed of 300 mm / min. After 20 minutes and 72 hours, the tape was peeled off from the silicone rubber at a 180° angle and a speed of 300 mm / min to measure peel adhesion.

[0133] Examples 1 to 10

[0134] The additives shown in Table 2 below were used in amounts of 6 parts by weight to prepare a silicone pressure-sensitive adhesive composition, and the adhesive composition was coated onto a PET film using the general procedure described above to prepare a silicone pressure-sensitive tape. The peel adhesion of the tape was tested at 180 degrees Celsius after 20 minutes and 72 hours, respectively.

[0135] Table 2 Peel adhesion of boron-containing compounds alone

[0136]

[0137] *: Boron-containing compounds and SR545 silicone resin were not used in the reference examples.

[0138] As can be seen from Table 2, under the same conditions, compounds 2 to 6 alone provide silicone pressure-sensitive adhesive compositions with significantly improved peel adhesion to silicone rubber compared to compound 1.

[0139] Examples 11 to 19

[0140] The additives shown in Table 3 below were combined with 6 parts by weight of Compound 1 at a rate of 0.17 parts by weight to prepare a silicone pressure-sensitive adhesive composition. The adhesive composition was then coated onto a PET film using the general procedure described above to prepare a silicone pressure-sensitive tape. The peel adhesion of the tape was then tested at 180 degrees Celsius after 20 minutes and 72 hours, respectively.

[0141] Table 3 Peel adhesion of boron-containing compound combinations

[0142]

[0143] As can be seen from Tables 2 and 3, the combinations of compounds 2, 7, 8, and 9 with compound 1 achieved synergistic effects, as the peel adhesion of the silicone pressure-sensitive adhesive compositions provided by any of these combinations to silicone rubber was higher than the corresponding adhesion obtained when they were used alone. The combination of compounds 2, 8, and 9 with compound 1 achieved a further improved peel adhesion to silicone rubber, unexpectedly exceeding 1000 gf / in. In terms of appearance, the silicone pressure-sensitive adhesive compositions using compound 2 are clear when used in combination with compound 1. Compounds 7, 8, and 9 are less clear when used in combination with compound 1 compared to compound 2, which may be due to their polar nature.

[0144] Example 20

[0145] The silicone pressure-sensitive adhesive composition prepared in Example 11 was aged for 8 weeks at room temperature and 40°C, respectively. The changes in viscosity and appearance of the adhesive composition over time are shown in Table 4 below.

[0146] The silicone pressure-sensitive adhesive composition, aged for 8 weeks, was coated onto a PET film using the general procedure described above to prepare a silicone pressure-sensitive tape. The peel adhesion of the tape to silicone rubber was then tested at 180 degrees Celsius after 20 minutes, 24 hours, and 72 hours. The peel adhesion results of the aged adhesive composition are compared with those of the unaged, freshly prepared adhesive composition. Figure 1 In. Figure 1 In the bar chart, which is divided into groups of three, the left bar represents fresh, unaged samples, the middle bar represents samples aged at room temperature, and the right bar represents samples aged at 40°C.

[0147] Table 4 Viscosity and Appearance Results of Adhesive Compositions

[0148] Viscosity (cps) 1.33 1.33 1.34 1.34 1.34 1.35 Appearance clarify clarify clarify clarify clarify clarify 40℃ aging initial 1 week 3 weeks 4 weeks 6 weeks 8 weeks Viscosity (cps) 1.34 1.34 1.35 1.36 1.36 1.37 Appearance clarify clarify clarify clarify clarify clarify

[0149] As can be seen from Table 4, the viscosity and appearance of the composition remain essentially unchanged over time at room temperature and at an elevated temperature of 40°C.

[0150] In addition, from Figure 1 It can be seen that the peel adhesion to silicone rubber obtained from freshly prepared unaged samples and samples aged at different temperatures (room temperature and 40°C) is basically the same.

[0151] All the above results indicate that the silicone pressure-sensitive adhesive composition of the present invention has excellent room temperature and high temperature storage stability.

[0152] Examples 21 to 26

[0153] Compound 2 and Compound 1 were used in combination in varying amounts as shown in Table 5 to prepare a silicone pressure-sensitive adhesive composition. The adhesive composition was coated onto a PET film using the general procedure described above to prepare a silicone pressure-sensitive tape. The peel adhesion of the tape at 180 degrees Celsius was then tested after 20 minutes and 72 hours, respectively. The results are shown in Table 5 and... Figure 2 middle.

[0154] Table 5. Peel adhesion of boron-containing compounds with varying ratios

[0155]

[0156] Surprisingly, the improvement in peel adhesion to silicone rubber provided by compound 2 was found to be disproportionate to its amount, as shown in Table 5, and also as Figure 2 As shown in the diagram, the maximum improvement in peel adhesion provided by compound 2 can be achieved at a very low weight ratio of approximately 1:35 (compound 2: compound 1). This technical effect facilitates further reductions in the additive load required to achieve the peel adhesion desired for low-energy surfaces.

[0157] Example 27

[0158] The silicone pressure-sensitive tapes prepared according to Reference Example and Example 23 were respectively attached to the fluorinated release film FL132 (from Housewell) to form a laminate. Next, the laminate was aged at room temperature and 40°C respectively, and then the peel force (180 degrees) against the release liner FL132 was tested weekly at room temperature according to FINAT test method No. 3 (low-speed peel force) using the following procedure.

[0159] The entire test area of ​​the laminate was secured with double-sided tape, and then rolled back and forth once with a 2kg roller at a speed of 300mm / min. Next, the laminate was peeled off at a 180° angle and a speed of 300mm / min to measure the peel force required to separate the release film from the pressure-sensitive adhesive tape.

[0160] The measured peel force results are as follows Figure 3 (room temperature) and Figure 4 As shown in (at a temperature of 40°C). The results show that the silicone pressure-sensitive adhesive composition of the present invention has a more suitable peel force than conventional release films, and the peel force remains substantially stable over time at both room temperature and elevated temperatures of 40°C.

[0161] While this disclosure has been described with reference to preferred embodiments, those skilled in the art will understand that various changes can be made and elements thereof can be substituted with equivalents without departing from the scope of this disclosure. Furthermore, numerous modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from its essential scope. Therefore, it is intended that this disclosure be limited to the specific embodiments disclosed as the best mode contemplated for carrying out this disclosure, but rather that this disclosure will include all embodiments falling within the scope of the appended claims.

Claims

1. An organosilicon pressure-sensitive adhesive composition comprising: At least one boron-containing additive comprising a boron-containing compound selected from compounds based on cycloboroxanes and borane-based compounds containing covalent boron-nitrogen bonds. The compounds based on cycloboroxanes described above have the general formula (I): Equation (I) Where R 1 R 2 and R 3 Each is independently a hydrogen atom; a hydroxyl group; or a monovalent group having up to 30 carbon atoms, selected from alkyl, alkoxy, hydroxyalkyl, alkoxyalkyl, or -R 8 -N(R 9 (R) 10 ), where R 8 It is a direct bond or a divalent linker, and R 9 and R 10 Each is independently a hydrogen atom, alkyl, hydroxyalkyl, or alkoxyalkyl; The borane-based compounds containing covalent boron-nitrogen bonds described above have the general formula (II): Equation (II) Where R 4 and R 5 Each is an independent monovalent group having up to 30 carbon atoms, selected from alkyl, alkoxy, hydroxyalkyl, alkoxyalkyl, and -R groups. 8 -N(R 9 (R) 10 ), where R 8 It is a covalent or divalent linker, and R 9 and R 10 Each is independently a hydrogen atom, alkyl, hydroxyalkyl, or alkoxyalkyl; and Where R 6 and R 7 Each is an alkyl, hydroxyalkyl, or alkoxyalkyl group that is independently composed of hydrogen atoms or has at most 30 carbon atoms.

2. The silicone pressure-sensitive adhesive composition according to claim 1, wherein R 4 and R 5 Together they form an alkylene ring containing up to 10 carbon atoms bonded to the B atom of formula (II) via oxygen atoms.

3. The silicone pressure-sensitive adhesive composition according to claim 1, wherein R 1 R 2 and R 3 Each is an independent monovalent group having up to 20 carbon atoms, selected from alkoxy, alkoxyalkyl, or -R groups. 8 -N(R 9 (R) 10 ), where R 8 It is a direct bond, alkylene, or oxyalkylene, and R 9 and R 10 Each is independently a hydrogen atom, an alkyl group, or an alkoxyalkyl group.

4. The organosilicon pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the cycloboroxane-based compound has general formula (I-1) or general formula (I-2): Equation (I-1) Where R 11 R 12 and R 13 Each is an independent monovalent group having up to 20 carbon atoms, selected from alkyl or -R groups. 14 -N(R 15 (R) 16 ) of which R 14 It is an alkylene group, and R 15 and R 16 Each is independently a hydrogen atom, an alkyl group, or an alkoxyalkyl group; Equation (I-2) Each R 17 It is independently a hydrogen atom or an alkyl or alkoxyalkyl group having up to 20 carbon atoms.

5. The silicone pressure-sensitive adhesive composition according to claim 4, wherein R 11 R 12 and R 13 Each is an alkyl group having 1 to 10 carbon atoms.

6. The silicone pressure-sensitive adhesive composition according to claim 4, wherein each R 17 It is independently a hydrogen atom or an alkyl group having up to 10 carbon atoms.

7. The silicone pressure-sensitive adhesive composition according to claim 1, wherein the borane-based compound containing covalent boron-nitrogen bonds has the general formula (II-1): Equation (II-1) Where R 21 R 22 R 23 R 24 R 25 and R 26 Each is an alkyl, hydroxyalkyl, or alkoxyalkyl group that is independently composed of hydrogen atoms or has at most 20 carbon atoms.

8. The silicone pressure-sensitive adhesive composition according to claim 7, wherein R 21 R 22 R 23 R 24 R 25 and R 26 Alkyl groups, each having at most 10 carbon atoms.

9. The silicone pressure-sensitive adhesive composition according to claim 1, wherein the borane-based compound containing a covalent boron-nitrogen bond has the general formula (II-2): Equation (II-2) Where R 27 and R 28 Each is an independent monovalent group having up to 20 carbon atoms, selected from alkyl or -R groups. 31 -N(R 32 (R) 33 ), where R 31 It is an alkylene group, and R 32 and R 33 Each is independently a hydrogen atom, alkyl group, or alkoxyalkyl group; and Where R 29 and R 30 Each is an alkyl, hydroxyalkyl, or alkoxyalkyl group that is independently composed of hydrogen atoms or has at most 20 carbon atoms.

10. The silicone pressure-sensitive adhesive composition according to claim 9, wherein R 27 and R 28 Each is an alkyl group having at most 10 carbon atoms.

11. The silicone pressure-sensitive adhesive composition according to claim 9, wherein R 27 and R 28 Together they form an alkylene ring containing 1-6 carbon atoms bonded to the O atom of formula (II-2).

12. The silicone pressure-sensitive adhesive composition according to claim 9, wherein R 29 and R 30 Alkyl groups, each having at most 10 carbon atoms.

13. The silicone pressure-sensitive adhesive composition according to claim 9, wherein R 27 and R 28 Together they form a ring containing -CH2CH2-, -CH2CH2CH2-, -CH2CH(CH3)-, -CH(CH3)CH(CH3)-, -CH2CH(CH3)CH2- or -CH2C(CH3)2CH2- that is bonded to the O atom of formula (II-2).

14. The silicone pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the at least one boron-containing additive further comprises an acyclic borate compound selected from boric acid, acyclic borate compounds, and combinations thereof.

15. The silicone pressure-sensitive adhesive composition according to claim 14, wherein the acyclic borate compound is selected from trialkyl borate.

16. The silicone pressure-sensitive adhesive composition according to claim 15, wherein the acyclic borate compound is selected from trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, triisobutyl borate, tripentyl borate, trioctyl borate, trilauryl borate, tristearyl borate, and combinations thereof.

17. The silicone pressure-sensitive adhesive composition according to claim 14, wherein the weight ratio of the boron-containing compound to the acyclic borate compound is 1:100 to 1:

1.

18. The silicone pressure-sensitive adhesive composition according to claim 17, wherein the weight ratio of the boron-containing compound to the acyclic borate compound is 1:70 to 1:

1.

19. The silicone pressure-sensitive adhesive composition according to claim 14, wherein the boron-containing compound is selected from the cycloboroxane-based compound, the acyclic boric acid compound is selected from acyclic borate ester compounds, and the weight ratio of the cycloboroxane-based compound to the acyclic borate ester compound is 1:100 to 1:

1.

20. The silicone pressure-sensitive adhesive composition according to claim 19, wherein the weight ratio of the cycloboroxane-based compound to the acycloboronic ester compound is from 1:40 to 1:

4.

21. The silicone pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the total amount of the at least one boron-containing additive is 1 to 10 by weight based on the total weight of the silicone pressure-sensitive adhesive composition.

22. An organosilicon pressure-sensitive adhesive composition comprising: At least one boron-containing additive comprising at least two members selected from: i) cyclic borate esters or cyclic borate compounds or boron-containing compounds as defined in any one of claims 1 to 21; ii) Boric acid; and iii) Acyclic borate esters.

23. The silicone pressure-sensitive adhesive composition according to claim 22, wherein the at least one boron-containing additive comprises a combination of an acyclic borate ester compound (iii) and at least one of the following: the boron-containing compound, the cyclic borate ester or salt compound, or boric acid.

24. The silicone pressure-sensitive adhesive composition according to claim 23, wherein the acyclic borate compound (iii) is a trialkyl borate ester.

25. The silicone pressure-sensitive adhesive composition according to claim 23, wherein the acyclic borate ester compound is present in an amount of 50% to 99% by weight relative to the total amount of the at least one boron-containing additive.

26. The silicone pressure-sensitive adhesive composition according to any one of claims 22 to 25, wherein the at least one boron-containing additive comprises a combination of an acyclic borate ester compound and a compound having general formula (I) as defined in claim 1 or 3.

27. The silicone pressure-sensitive adhesive composition of claim 26, wherein the at least one boron-containing additive comprises a combination of an acyclic borate ester compound and a compound having the general formula (I-1) as defined in claim 4.

28. The silicone pressure-sensitive adhesive composition according to claim 26, wherein the weight ratio of the cycloboroxane-based compound to the acycloboronic ester compound is from 1:100 to 1:

1.

29. The silicone pressure-sensitive adhesive composition according to claim 28, wherein the weight ratio of the cycloboroxane-based compound to the acycloboronic ester compound is from 1:40 to 1:

4.

30. The silicone pressure-sensitive adhesive composition according to any one of claims 22 to 25, wherein the at least one boron-containing additive comprises a combination of the acyclic borate ester compound and a cyclic borate ester or salt compound having general formula (III): (III) Where R 34 and R 35 Each is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms; L 1 L 2 and L 3 Each is independently represented by the formula - [C(O)] m C n H 2n - a divalent group, where m is 0 or 1, and n is an integer from 0 to 4, provided that R 34 and R 35 When they form a ring together, for L 1 L 2 and L 3 At least one of the defined m is 0.

31. The silicone pressure-sensitive adhesive composition according to claim 30, wherein R 34 and R 35 Together they form a formula containing -OL 3 A ring of divalent groups of -CH2-, wherein -L 3 - The group is bonded to the B atom of formula (III) via an oxygen atom.

32. The silicone pressure-sensitive adhesive composition according to any one of claims 1 to 3, further comprising: Polyorganosiloxane compounds; and Organosilicon resin, comprising at least one of the formula M=R3SiO 1 / 2 The M-element and at least one element selected from the following: Equation T=RSiO 3 / 2 The T-unit and the formula Q=SiO 4 / 2 The Q unit, wherein each R is an independent monovalent hydrocarbon group with 1 to 6 carbon atoms.

33. The silicone pressure-sensitive adhesive composition according to claim 32, wherein the silicone resin further comprises at least one component of the formula D=R2SiO 2 / 2 The D unit, where each R is an independent monovalent hydrocarbon group with 1 to 6 carbon atoms.

34. The silicone pressure-sensitive adhesive composition according to claim 32, further comprising: a curing catalyst.

35. The silicone pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the composition is cured by a free radical reaction or a hydrosilaneization reaction.

36. An article comprising the silicone pressure-sensitive adhesive composition according to any one of claims 1 to 35.

37. The article of claim 36, wherein the article is a pressure-sensitive adhesive tape.

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