Two-component polyurethane-(meth)acrylic hybrid adhesive composition

Abstract

The present invention relates to two-part polyurethane-(meth)acrylic hybrid adhesive compositions, in particular two-part polyurethane-(meth)acrylic hybrid adhesive compositions that include a specific cure system but do not include the typical catalysts for polyurethane formation.

Description

[Technical field]

[0001] The present invention relates to a two-part polyurethane-(meth)acrylic hybrid adhesive composition, and in particular to a two-part polyurethane-(meth)acrylic hybrid adhesive composition that includes a specific cure system but does not include a typical catalyst for polyurethane formation. [Background technology]

[0002] (Meth)acrylic adhesives and polyurethane (PU) adhesives are known adhesives, (meth)acrylic adhesives have excellent performance such as cure speed and good adhesion to various substrates, but have disadvantages such as large volume shrinkage. PU adhesives have excellent chemical resistance and toughness, but have disadvantages such as slow cure speed. Polyurethane-(meth)acrylic hybrid adhesives combine the advantages of (meth)acrylic adhesives and PU adhesives.

[0003] US Patent No. 8,742,020 relates to polyurethane-(meth)acrylic hybrid adhesives that contain organoborane amine complexes as initiators for curing the (meth)acrylic component. Organoboranes are pyrophoric and therefore need to be complexed to avoid oxidative decomposition in air. On the other hand, to ensure an acceptable shelf life, an excess of amine is used to generate the borane:amine complex.

[0004] US Patent Publication No. 2019 / 0330432 relates to a polyurethane-(meth)acrylic hybrid adhesive containing uretdione dimer as a PU-forming component, which needs to be cured at a relatively high temperature of 120-200°C due to the unblocking reaction of polyurethane dimer. Such hybrid adhesives based on uretdione dimers are not suitable for applications requiring rapid curing at low temperatures. On the other hand, such hybrid adhesive compositions contain typical PU catalysts selected from dibutyltin dilaurate, zinc octanoate, bismuth neodecanoate, tertiary amines, preferably 1,4-diazabicyclo[2.2.2]octane, and in one part contain cumene hydroperoxide (CHP), polyols and dibutyltin dilaurate (DBTL), but the combination of such peroxides and DBTL in one part leads to storage instability (as demonstrated in the examples section of the present invention).

[0005] US 2014 / 0275345 also discloses polyurethane-(meth)acrylic hybrid adhesives containing uretdione dimers as components to produce PU, but these are also not suitable for rapid curing at low temperatures. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 8742020 [Patent Document 2] US Patent Application Publication No. 2019 / 0330432 [Patent Document 3] US Patent Application Publication No. 2014 / 0275345 Summary of the Invention [Problem to be solved by the invention]

[0007] When hybrid adhesives are used in electronic devices such as cell phones, high toughness is required to prevent adhesive failure due to dropping, while still maintaining good adhesive strength. [Means for solving the problem]

[0008] After extensive investigation, the inventors have surprisingly found that the above-mentioned desired effects, i.e., good adhesive strength and excellent toughness, can be achieved by using a specific curing system consisting of a curing accelerator, a peroxide and a copper (II)-based catalyst, without using a typical polyurethane catalyst.

[0009] During the course of this invention, the inventors have found that typical polyurethane catalysts, such as organotin(IV) or tertiary amine-based catalysts, perform poorly in polyurethane-(meth)acrylic hybrid systems, and that copper(II)-based catalysts may provide optimal performance. It is believed that the copper(II)-based catalyst acts both as a redox cure accelerator for the (meth)acrylic component and as a catalyst for polyurethane formation.

[0010] In view of the above findings, the present invention provides Part A): A1) polyol; A2) saccharin; saccharin derivatives in which the hydrogen atom in -NH- is replaced by a hydroxyl or alkoxy group; toluidines such as N,N-diethyl-p-toluidine (DE-pT) and N,N-dimethyl-o-toluidine (DM-oT); acetylphenylhydrazine (APH); formulas (1) and (2): [ka] [R in formula (1)] 1 , R 2 and R 3 And R in formula (2) 1 , R 2 and R 4 are each independently H or C 1~4alkyl; Z is a carbon-carbon single bond or a carbon-carbon double bond; and p is an integer from 1 to 5. and mixtures thereof; A3) peroxide; A4) optionally a (meth)acrylic component; Part B): B1) polyisocyanates, B2) Copper(II)-based catalysts; B3) optionally a (meth)acrylic component; wherein the (meth)acrylic component is present in only Part A, or in only Part B, or in both Parts A and B.

[0011] In another aspect, the present invention provides a method of bonding substrates using the adhesive composition of the present invention.

[0012] In another aspect, the present invention provides articles bonded with the cured product of the adhesive composition of the present invention.

[0013] In yet another aspect, the present invention provides the use of a curing system in a two-part polyurethane-(meth)acrylic hybrid adhesive composition, the curing system comprising in one part a curing accelerator and a peroxide, and in another part a copper(II)-based catalyst.

[0014] Advantages of the present invention include at least: 1) good adhesive strength can be achieved without the use of typical PU catalysts; 2) excellent toughness of the adhesive can be achieved. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Those skilled in the art should appreciate that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the invention. Each aspect thus described may be combined with other aspects unless expressly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with one or more other features indicated as being preferred or advantageous.

[0016] Unless otherwise specified, as used herein, the terms "a," "an," and "the" include singular and plural referents.

[0017] As used herein, the terms "comprising" and "comprises" are synonymous with "including," "including," or "containing," and are inclusive or open-ended and do not exclude additional, unrecited components, elements or process steps.

[0018] As used herein, the term "consisting essentially of" means that the recited components make up the majority of the composition, e.g., at least 80%, at least 85%, or at least 90% by weight of the composition, and that other unrecited components do not affect the effectiveness of the composition.

[0019] As used herein, the term "consisting of" is closed-ended and excludes additional, unrecited materials, elements or process steps.

[0020] As used herein, the term "(meth)acrylic" refers to both "acrylic" and "methacrylic."

[0021] The terms "at least one" or "one or more" as used herein to define a component refer to the type of component and not to the absolute number of molecules. For example, "one or more monomers" refers to one type of monomer or a mixture of different monomers.

[0022] The term "polyol" is meant to include materials having an average of two or more hydroxyl groups per molecule.

[0023] As used herein in connection with numerical values, the terms "about," "around," and the like refer to the numerical value ±10%, preferably ±5%. All numerical values ​​herein should be construed as being modified by the term "about."

[0024] Unless otherwise specified, the recitation of numerical endpoints includes all values ​​and fractions subsumed within the respective ranges, as well as the recited endpoints.

[0025] All documents cited herein are incorporated by reference in their entirety.

[0026] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the meaning commonly understood by one of ordinary skill in the art to which this invention belongs.

[0027] The two-component polyurethane-(meth)acrylic hybrid adhesive composition will now be described in detail.

[0028] Part A A1) Polyol The first essential component of Part A includes one or more polyols.

[0029] The polyol becomes part of the final PU network through reaction with the polyisocyanate, and conventional polyols used in the production of PU adhesives, such as polyester polyols, polyether polyols, or low molecular weight polyols, can be used in the present invention without particular limitation.

[0030] Suitable polyester polyols include, for example, the reaction products of polyhydric alcohols, preferably dihydric alcohols (optionally in the presence of trihydric alcohols), with polybasic carboxylic acids, preferably dibasic carboxylic acids. Instead of using free carboxylic acids, the corresponding polycarboxylic acid anhydrides or the corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof can also be used to prepare the polyesters. The polycarboxylic acids can be aliphatic, cycloaliphatic, aromatic and / or heterocyclic, and can be unsaturated or substituted (e.g. with halogen atoms).

[0031] Suitable polyether polyols can be prepared by reacting suitable starting compounds containing reactive hydrogen atoms with alkylene oxides, such as, for example, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, epichlorohydrin, and mixtures thereof. Suitable starting compounds containing reactive hydrogen atoms include, for example, ethylene glycol, propylene glycol, butylene glycol, hexanediol, octanediol, neopentyl glycol, cyclohexanedimethanol, 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol, glycerin, trimethylolpropane, pentaerythritol, water, methanol, ethanol, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylolethane, mannitol, sorbitol, methyl glycoside, sucrose, phenol, resorcinol, hydroquinone, 1,1,1- or 1,1,2-tris-(hydroxyphenyl)-ethane, and the like.

[0032] Suitable low molecular weight polyols include, for example, ethylene glycol, 1,2- and 1,3-propanediol, isomeric butanediols, neopentyl glycol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-n-butyl-2-ethyl-1,3-propanediol, glycerol monoalkanoates (such as glycerol monostearate), dimeric fatty alcohols, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,4-dimethylolcyclohexane, dodecanediol, alkoxylated bisphenol A, hydrogenated bisphenol A, 1,3-hexanediol, 1 ,3-octanediol, 1,3-decanediol, 3-methyl-1,5-pentanediol, 3,3-dimethyl-1,2-butanediol, 2-methyl-1,3-pentanediol, 2-methyl-2,4-pentanediol, 3-hydroxymethyl-4-heptanol, 2-hydroxymethyl-2,3-dimethyl-1-pentanol, glycerol, trimethylolethane, trimethylolpropane, trimer fatty alcohols, isomeric hexanetriols, sorbitol, pentaerythritol, ditrimethylolpropane, dipentaerythritol, diglycerol, and 4,8-bis(hydroxymethyl)-tricyclo[5.2.02-6]-decane (TCD alcohol).

[0033] The polyol can be included in Part A in an amount of 10 to 70% by weight, preferably 30 to 60% by weight, for example 15% by weight, 20% by weight, 25% by weight, 28% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, etc., based on the total weight of Part A.

[0034] A2) Curing accelerator The second essential component of Part A includes one or more cure accelerators, as defined below.

[0035] The hardening accelerators that can be used in the present invention are selected from: -saccharin, Saccharin derivatives in which the hydrogen atom in --NH- is replaced by a hydroxyl or alkoxy group; - toluidines, such as N,N-diethyl-p-toluidine and N,N-dimethyl-o-toluidine, -Acetylphenylhydrazine (APH), -Equations (1)~(2): [ka] [R in formula (1)] 1 , R 2 and R 3 And R in formula (2) 1 , R 2 and R 4 are each independently H or C 1~4 alkyl; Z is a carbon-carbon single bond or a carbon-carbon double bond; and p is an integer from 1 to 5. A compound represented by the formula: - and mixtures thereof.

[0036] Specifically, specific examples of such accelerators within the scope of formula (1) and formula (2) include the following: [ka]

[0037] The hardening accelerator is a component of certain hardening systems of the present invention and can include one or more of the above compounds. Preferably, saccharin and APH can be used in combination as hardening accelerators of the present invention.

[0038] The cure accelerator can be included in Part A in an amount of 0.2 to 5 wt.%, preferably 0.3 to 2 wt.%, for example 0.4 wt.%, 0.6 wt.%, 0.8 wt.%, 1.0 wt.%, 1.2 wt.%, 1.5 wt.%, 2.5 wt.%, 3.0 wt.%, 3.5 wt.%, 4.0 wt.%, 4.5 wt.%, etc., based on the total weight of Part A.

[0039] A3) Peroxide Peroxides are components of certain curing systems of the present invention and can act as oxidizing agents in a redox system to initiate the polymerization reaction of the (meth)acrylic component. One or more peroxides as defined below can be used in the present invention.

[0040] The peroxides that can be used for the purposes of the present invention are preferably organic peroxides represented by the general formula: ROO-R', where R and R' are independently an organic group. Examples of peroxides include sulfonyl peroxides such as acetylcyclohexanesulfonyl peroxide; percarbonates such as dicyclohexyl peroxydicarbonate; di-n-butyl peroxydicarbonate and diisopropyl peroxydicarbonate; peresters such as tert-butyl peroxypivalate, tert-butyl perneodecanoate and tert-butyl perbenzoate; diacyl peroxides such as bis-(3,3,5-trimethylhexanoyl)-peroxide; dilauroyl peroxide; didecanoyl peroxide, dipropionyl peroxide, etc. dialkyl peroxides such as dicumyl peroxide and di-tert-butyl peroxide; ketal peroxides such as 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane; alkyl hydroperoxides such as cumene hydroperoxide, paramethane hydroperoxide, and tert-butyl hydroperoxide; and ketone peroxides such as cyclohexanone peroxide and ethyl methyl ketone peroxide.

[0041] The peroxide can be included in Part A in an amount of 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the total weight of Part A, for example, 0.3% by weight, 0.7% by weight, 1.0% by weight, 1.2% by weight, 1.4% by weight, 1.6% by weight, 1.8% by weight, 2.0% by weight, 2.2% by weight, 2.4% by weight, 2.6% by weight, 2.8% by weight, 3.0% by weight, 3.5% by weight, 4.0% by weight, 4.5% by weight, etc.

[0042] A4) (Meth)acrylic component Optional components of Part A, when present, can include one or more (meth)acrylic compounds.

[0043] The (meth)acrylic component may include (meth)acrylic acid and / or (meth)acrylate that have been conventionally used in the production of adhesives, and is not particularly limited. For example, the (meth)acrylic component may include a monofunctional (meth)acrylic monomer and / or a polyfunctional (meth)acrylic monomer.

[0044] By monofunctional (meth)acrylic monomer it is intended to mean a monomer having one (meth)acryloyl group, and by polyfunctional (meth)acrylic monomer it is intended to mean a monomer having multiple (meth)acryloyl groups, for example having 2 to 6 (meth)acryloyl groups.

[0045] In the present invention, the types of monofunctional (meth)acrylic monomers and polyfunctional (meth)acrylic monomers are not particularly limited, and those that have been conventionally used can be used in the adhesive composition.

[0046] Examples of monofunctional (meth)acrylic monomers include (meth)acrylic acid, n-butyl (meth)acrylate, 2-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, pentyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-methylbutyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, isoamyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, 4-methyl-2-pentyl aryl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, allyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and hydroxyalkylene glycol (meth)acrylates (having 2 to 4 carbon atoms), such as 2-hydroxyethylene glycol (meth)acrylate and 2-hydroxypropylene glycol (meth)acrylate, may be mentioned, but are not limited to these.

[0047] Examples of polyfunctional (meth)acrylic monomers include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, bisphenol A-ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, Triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, di(acryloxyethyl)isocyanurate, allylated cyclohexyl di(meth)acrylate ) acrylate, dimethylol dicyclopentane di(meth)acrylate, neopentyl glycol modified trimethylolpropane di(meth)acrylate, adamantine di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate and other bifunctional (meth)acrylic monomers; trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane trifunctional monomers such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, tetramethylolpropane tetra(meth)acrylate, pentafunctional monomers such as dipentaerythritol penta(meth)acrylate, and hexafunctional monomers such as dipentaerythritol hexa(meth)acrylate, but are not limited to these.

[0048] The (meth)acrylic component is an essential component of the adhesive composition, but may be present only in Part A, only in Part B, or in both Part A and Part B. The total amount of the (meth)acrylic component may be 20 to 65% by weight, preferably 30 to 55% by weight, for example 25% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 60% by weight, based on the total weight of the adhesive composition. The (meth)acrylic compound may be used alone or in admixture in each part.

[0049] When present in Part A, the (meth)acrylic component can be included in an amount of 5 to 65% by weight, for example, 6% by weight, 8% by weight, 10% by weight, 12% by weight, 15% by weight, 18% by weight, 20% by weight, 25% by weight, 28% by weight, 30% by weight, 35% by weight, 38% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, etc., based on the total weight of Part A.

[0050] Part B B1) Polyisocyanate The polyisocyanate in part B) can react with the polyol in part A) to produce a PU network. In the present invention, any polyisocyanate conventionally used in PU adhesives can be used without any particular limitation. In the present invention, one or more polyisocyanates can be included.

[0051] The term "polyisocyanate" means that the molecule contains two or more isocyanate groups.

[0052] For example, examples of suitable polyisocyanates herein include alkylene diisocyanates, cycloalkylene diisocyanates, aromatic diisocyanates, and aliphatic-aromatic diisocyanates.Specific examples of suitable isocyanate-containing compounds include ethylene diisocyanate, ethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, cyclopentylene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, cyclohexylene-1,2-diisocyanate, 4,4'-diphenyl diisocyanate, cyclohexylene-1,4-diisocyanate, cyclohexylene-1,2-di ... Methane diisocyanate, 2,2-diphenylpropane-4,4'-diisocyanate, xylylene diisocyanate, 1,4-naphthylene diisocyanate, 1,5-naphthylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, diphenyl-4,4'-diisocyanate, azobenzene-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, 2,4-tolylene diisocyanate cyanate, dichlorohexamethylene diisocyanate, furfurylidene diisocyanate, 1-chlorobenzene-2,4-diisocyanate, 4,4',4"-triisocyanatotriphenylmethane, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, 4,4'-dimethyldiphenylmethane-2,2',5,5-tetraisocyanate, isophorone diisocyanate, methylene bisphenyl diisocyanate (MDI), hydrogenated MDI, poly MDI, polyesters containing diisocyanates, polycarbonates containing diisocyanates, polyethylene glycols containing diisocyanates, polypropylene glycols containing diisocyanates, polytetramethylene glycol ethers containing diisocyanates, polycaprolactones containing diisocyanates, polyethers containing diisocyanates, and the like, but are not limited to these.

[0053] The polyisocyanate can be included in Part B in an amount of 20 to 75% by weight, preferably 30 to 55% by weight, such as 25% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 60% by weight, 65% by weight, 70% by weight, etc., based on the total weight of Part B.

[0054] B2) Copper(II)-based catalysts Copper(II)-based catalysts are components of certain cure systems of the present invention and can act as reducing agents in redox systems to initiate the polymerization reaction of the (meth)acrylic component and can also catalyze the PU formation reaction. One or more copper(II)-based catalysts can be included in Part B.

[0055] Examples of copper(II)-based catalysts include copper(II) complexes such as copper trifluoroacetylacetonate, copper hexafluoroacetylacetonate, copper acetylacetonate, copper naphthenate, copper octoate, copper tetrafluoroborate, copper salicylate, copper sulfate, copper chloride, copper bromide, copper fluoride, copper methacrylate, and copper triflate.

[0056] The copper(II)-based catalyst may be included in an amount of 1 to 5000 ppm, preferably 20 to 200 ppm, for example, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 120 ppm, 140 ppm, 160 ppm, 180 ppm, 220 ppm, 250 ppm, 300 ppm, 350 ppm, 400 ppm, 450 ppm, 500 ppm, 550 ppm, 600 ppm, 650 ppm, 700 ppm, based on the total weight of Part B.

[0057] B3) (Meth)acrylic component If present, the (meth)acrylic components suitable for Part B can be independently selected from those described above for Part A, and can be the same or different from those used in Part A.

[0058] When present in Part B, the (meth)acrylic component can be included in an amount of 5 to 65% by weight, for example, 6% by weight, 8% by weight, 10% by weight, 12% by weight, 15% by weight, 18% by weight, 20% by weight, 25% by weight, 28% by weight, 30% by weight, 35% by weight, 38% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, etc., based on the total weight of Part B.

[0059] All of the above specified amounts of each component are based on the assumption that Part A and Part B are mixed in a 1:1 weight ratio. If Part A and Part B are not used in a 1:1 weight ratio, the above specified amounts can be adjusted accordingly to provide a similar final mixing ratio of the components, and the adjusted amounts are also intended to fall within the scope of the present invention.

[0060] Other Ingredients In addition to the components described above, the adhesive compositions of the present invention can optionally contain other conventional additives in Part A and / or Part B, provided that the additives in Part A are non-reactive with the components of Part A and the additives in Part B are non-reactive with the components of Part B.

[0061] Specifically, Part A is free of amine-reactive and hydroxyl-reactive components, and Part B is free of isocyanate-reactive and copper(II)-reactive components.

[0062] For example, Part A and / or Part B can include rheology modifiers such as talc, clay, carbon black and mica, fumed, precipitated and optionally silanated silica; defoamers such as alcohols, hydrocarbons, paraffin-based mineral oils, glycol derivatives, acetates and polysiloxanes; stabilizers such as UV stabilizers, free radical cure stabilizers (e.g., naphthaquinones and anthraquinones); dyes; wetting agents; dispersants and leveling agents; antioxidants such as hindered phenolic antioxidants, phosphite antioxidants and thioether antioxidants.

[0063] Method for joining substrates The present invention provides a method of bonding substrates using the adhesive composition of the present invention, which includes mixing Part A and Part B, applying the mixture of Part A and Part B to at least one substrate, then laminating the substrates together, and then curing the mixture, for example by exposing the laminated substrates to an elevated temperature of 30-100° C. for a predetermined time, such as 1-150 minutes, followed by exposure to room temperature for a predetermined time, such as at least 10 hours.

[0064] The adhesive composition can be applied to a substrate using any suitable application method, and the adhesive composition can be applied as a continuous or discontinuous coating, in single or multiple layers, and combinations thereof.

[0065] Joined articles The present invention provides articles bonded with the cured product of the adhesive composition of the present invention.

[0066] The adhesive compositions of the present invention are useful for a variety of electronic devices, including, for example, wearable electronic devices (e.g., watches and eyeglasses), portable electronic devices (e.g., phones (e.g., cell phones and mobile smart phones), cameras, tablets, e-readers, monitors (e.g., monitors used in hospitals, medical personnel, athletes, and individuals), watches, calculators, mice, touchpads, and joysticks), computers (e.g., desktop computers and laptop computers), computer monitors, televisions, media players, home appliances (e.g., refrigerators, washers, dryers, ovens, and microwaves), light bulbs (e.g., incandescent, light emitting diode, and fluorescent), and articles that include visible transparent or transparent parts, glass housing structures, transparent protective covers for displays or other optical components. EXAMPLES

[0067] The present invention will be illustrated by the following examples. The following examples are intended to help those skilled in the art to better understand and practice the present invention. The scope of the present invention is not limited by the examples, but is defined by the appended claims. Unless otherwise specified, all parts and percentages are by weight.

[0068] Preparation of Adhesive Composition The adhesive composition was prepared according to the ingredients and their amounts shown in Table 1. The ingredients for each part were placed in a mixing container with a lid and mixed in a Speedmixer DAC 150.1 FVZ-K at 2500 rpm for 10 minutes. The formulation was then loaded into a 50 mL 1:1 mix ratio 2-part cartridge, filled to the height of the piston. The cartridge was centrifuged at 1500 rpm for 2 minutes to remove any air bubbles. The piston was then installed into the cartridge.

[0069] Table 1 Materials: -PolyBD R20LM is a liquid hydroxyl-terminated butadiene polymer available from Cray Valley. - Sovermol 805 is a polyester / polyether polyol available from BASF. - Multranol 4012 is a polypropylene oxide based triol available from Covestro LLC. -DABCO: 1,4-diazabicyclo[2.2.2]octane. -Loctite HHD6010 Part B is a polyisocyanate component available from Henkel. - Eternathane 400U15 is a polyisocyanate component available from UBE. -Kraton D1155ES is a linear block copolymer based on styrene and butadiene. -Hypro VTB 2000x168 is a methacrylate terminated butadiene reactive liquid polymer manufactured by CVC Thermoset Specialties. -The wax is paraffin wax. -Premix 1 contains 5% benzoquinone in polyethylene glycol dimethacrylate. - Premix 2 contains 5% tetrasodium ethylenediaminetetraacetate in a mixture of ethylene glycol and water (50 / 50 w / w).

[0070] [Table 1-1]

[0071] [Table 1-2]

[0072] In these two-part compositions, Comparative Example 1 contains 0.2 wt. % dibutyltin dilaurate as a typical PU catalyst in part A; Comparative Example 2 contains 0.2 wt. % DABCO as a typical PU catalyst in Part A; Comparative Example 3 contains 0.2 wt. % dibutyltin dilaurate as a typical PU catalyst in Part B; Examples 1 to 5 do not contain a typical PU catalyst.

[0073] Performance of the adhesives of Comparative Examples 1 to 5 and Examples 1 to 5 stability The compositions were prepared as described above, and were stored at room temperature for 7 days, after which the hardening of each part of the composition was observed. The results are shown in Table 2.

[0074] [Table 2]

[0075] Table 3 shows that the inclusion of a polyurethane catalyst in Part A, which contains APH, saccharin, and peroxide, does not provide shelf life stability. These results demonstrate the limitations of the prior art (e.g., U.S. Patent Application Publication No. 2019 / 0330432) in the use of polyurethane catalysts in combination with peroxides.

[0076] Adhesive strength Adhesion testing was performed according to ASTM D3163-01. Testing was performed on stainless steel grade SUS304, 50% glass filled polyamide lap shear specimens, and DuPont Crastin SK05 in polybutylene terephthalate (PBT) material. The adhesive was dispensed from a 50 mL cartridge through a static mixer nozzle. Bonding was performed with a 0.5 inch overlap and initially cured at 45°C for 20 minutes, then at room temperature (RT) for 24 hours or at room temperature for 7 days. The results are shown in Tables 3-5.

[0077] [Table 3]

[0078] [Table 4]

[0079] [Table 5]

[0080] From Tables 3-5, it can be seen that, despite not containing a typical polyurethane catalyst, Examples 1-5 achieved equal or greater adhesive strengths both 24 hours and 7 days after the initial slow heat cure compared to the comparative examples containing a typical PU catalyst.

[0081] Toughness Performance Impact resistance tests were performed according to ISO 11343 "Adhesives - Determination of the dynamic resistance to fracture of high-strength adhesive bonds under impact conditions - Wedge impact method". The test substrates were symmetrically grit-blasted DC-04 wedge specimens. The adhesive application was performed with an induced adhesive gap of 125 μm, as in the previous test. The bonded specimens were cured at 45° C. for 20 min, followed by 24 h at room temperature. Impact resistance can reflect the toughness of the cured composition. The test results are shown in Table 6.

[0082] [Table 6]

[0083] Table 6 shows that omitting a typical polyurethane catalyst from the hybrid composition while using only the cure system of the present invention surprisingly resulted in a significant improvement in impact resistance.

[0084] While several preferred embodiments have been described, many modifications and variations are possible in light of the above teachings, and it is to be understood that the invention can be practiced otherwise than as specifically described without departing from the scope of the appended claims.

Claims

1. Part A): A1) polyol; A2) saccharin; saccharin derivatives in which the hydrogen atom in -NH- is replaced by a hydroxyl group or an alkoxy group; toluidines such as N,N-diethyl-p-toluidine and N,N-dimethyl-o-toluidine; acetylphenylhydrazine; 【Chemistry 1】 [R in formula (1)] １ , R ２ and R ３ And R in formula (2) １ , R ２ and R ４ are each independently H or C １～４ alkyl; Z is a carbon-carbon single bond or a carbon-carbon double bond; and p is an integer from 1 to 5. and mixtures thereof; A3) peroxides; A4) optionally a (meth)acrylic component; Part B): B1) polyisocyanates, B2) copper(II)-based catalysts; B3) optionally a (meth)acrylic component; wherein the (meth)acrylic component is present in only Part A, or only Part B, or in both Parts A and B.

2. 10. The composition of claim 1, wherein the (meth)acrylic components in Part A and Part B independently comprise monofunctional (meth)acrylic monomers and / or multifunctional (meth)acrylic monomers.

3. Monofunctional (meth)acrylic monomers include (meth)acrylic acid, n-butyl (meth)acrylate, 2-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, pentyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-methylbutyl (meth)acrylate, n-nonyl (meth)acrylate, 3. The composition of claim 2, wherein the acrylate is selected from isononyl (meth)acrylate, isoamyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, 4-methyl-2-pentyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, allyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, and mixtures thereof.

4. The polyfunctional (meth)acrylic monomers include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, bisphenol A-ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol Licor di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, di(acryloxyethyl)isocyanurate, allylated cyclohexyl di(meth)acrylate, Bifunctional (meth)acrylic monomers such as dimethylol dicyclopentane di(meth)acrylate, neopentyl glycol modified trimethylolpropane di(meth)acrylate, adamantine di(meth)acrylate, and tricyclodecane dimethanol di(meth)acrylate; trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, and propylene oxide modified trimethylolpropane tri(meth)acrylate.

3. The composition of claim 2, wherein the monomer is selected from trifunctional monomers such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, tris(acryloxyethyl)isocyanurate, etc.; tetrafunctional monomers such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, etc.; pentafunctional monomers such as dipentaerythritol penta(meth)acrylate, etc.; hexafunctional monomers such as dipentaerythritol hexa(meth)acrylate, etc., and mixtures thereof.

5. The composition according to any one of claims 1 to 4, wherein the polyol is selected from polyether polyols, polyester polyols and low molecular weight polyols.

6. The peroxides include sulfonyl peroxides such as acetylcyclohexanesulfonyl peroxide; percarbonates such as dicyclohexyl peroxydicarbonate; di-n-butyl peroxydicarbonate and diisopropyl peroxydicarbonate; peresters such as tert-butyl peroxypivalate, tert-butyl perneodecanoate, and tert-butyl perbenzoate; diacyl peroxides such as bis-(3,3,5-trimethylhexanoyl)-peroxide; dilauroyl peroxide; didecanoyl peroxide, dipropionyl peroxide; bis-(2, 6. The composition according to any one of claims 1 to 5, wherein the peroxide is selected from the group consisting of 4-dichlorobenzoyl) peroxide and dibenzoyl peroxide; dialkyl peroxides such as dicumyl peroxide and di-tert-butyl peroxide; ketal peroxides such as 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane; alkyl hydroperoxides such as cumene hydroperoxide, paramethane hydroperoxide and tert-butyl hydroperoxide; and ketone peroxides such as cyclohexanone peroxide and ethyl methyl ketone peroxide.

7. The composition according to any one of claims 1 to 6, wherein the polyisocyanate is selected from alkylene diisocyanates, cycloalkylene diisocyanates, aromatic diisocyanates, aliphatic-aromatic diisocyanates, polyesters containing diisocyanates, polycarbonates containing diisocyanates, polyethylene glycols containing diisocyanates, polypropylene glycols containing diisocyanates, polytetramethylene glycol ethers containing diisocyanates, polycaprolactones containing diisocyanates, and polyethers containing diisocyanates.

8. 8. The composition according to any one of claims 1 to 7, wherein the copper (II) based catalyst is selected from copper trifluoroacetylacetonate, copper hexafluoroacetylacetonate, copper acetylacetonate, copper naphthenate, copper octoate, copper tetrafluoroborate, copper salicylate, copper sulfate, copper chloride, copper bromide, copper fluoride, copper methacrylate and copper triflate.

9. The composition according to any one of claims 1 to 8, wherein the total amount of the (meth)acrylic component in the adhesive composition is in the range of 20 to 65 wt%, preferably 30 to 55 wt%, based on the total weight of the adhesive composition.

10. The composition according to any of the preceding claims, wherein the polyol is contained in Part A in an amount of 10 to 70% by weight, preferably 30 to 60% by weight, based on the total weight of Part A.

11. The composition according to any of the preceding claims, wherein the cure accelerator is contained in Part A in an amount of 0.2 to 5 wt%, preferably 0.3 to 2 wt%, based on the total weight of Part A.

12. The composition according to any of the preceding claims, wherein the peroxide is contained in Part A in an amount of 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the total weight of Part A.

13. The composition according to any of the preceding claims, wherein the polyisocyanate is contained in Part B in an amount of 20 to 75% by weight, preferably 30 to 55% by weight, based on the total weight of Part B.

14. The composition according to any of the preceding claims, wherein the copper (II) based catalyst is contained in part B in an amount of 1 to 5000 ppm, preferably 20 to 200 ppm, based on the total weight of part B.

15. An article comprising a cured product of the adhesive composition of any one of claims 1 to 14.

16. 13. A method of joining two substrates comprising mixing Part A and Part B of the adhesive composition of claim 1, applying the mixture of Part A and Part B to at least one of the substrates, laminating the substrates together, and then curing the mixture.

17. Use of a curing system in a two-part polyurethane-(meth)acrylic hybrid adhesive composition, comprising: The cure system comprises a cure accelerator and a peroxide in one part and a copper(II)-based catalyst in another part; the part containing the accelerator and peroxide is free of hydroxyl-reactive components and amine-reactive components; the part containing the copper(II)-based catalyst does not contain an isocyanate-reactive component; The hardening accelerator may be saccharin; saccharin derivatives in which the hydrogen atom in -NH- is replaced by a hydroxyl group or an alkoxy group; toluidines such as N,N-diethyl-p-toluidine and N,N-dimethyl-o-toluidine; acetylphenylhydrazine; 【Chemistry 2】 [R in formula (1)] １ , R ２ and R ３ And R in formula (2) １ , R ２ and R ４ are each independently H or C １～４ alkyl; Z is a carbon-carbon single bond or a carbon-carbon double bond; and p is an integer from 1 to 5. and mixtures thereof; The copper (II) based catalyst is selected from copper trifluoroacetylacetonate, copper hexafluoroacetylacetonate, copper acetylacetonate, copper naphthenate, copper octoate, copper tetrafluoroborate, copper salicylate, copper sulfate, copper chloride, copper bromide, copper fluoride, copper methacrylate, copper triflate and mixtures thereof.

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