KR20070097294A - Dual cure reaction products of self-photoinitiating multifunctional acrylates with cycloaliphatic epoxy compounds - Google Patents

Abstract

Photopolymerizable liquid oligomeric compositions are disclosed. The oligomeric compositions are formed from cycloaliphatic epoxides and Michael addition polyacrylate resins, synthesized from multifunctional acrylates and beta-dicarbonyl Michael donors, specifically beta- keto esters, beta-diketones, beta-ketoamides or beta- ketoanilides or combinations thereof. The oligomeric compositions are provided along with uses thereof and methods of fabricating.

Description

Dual Curing Reaction Products of Self-Photoinitiating Multifunctional Acrylates with Cycloaliphatic Epoxy Compounds

The present invention relates generally to photopolymerizable resins. The present invention specifically relates to an oligomer composition comprising an alicyclic epoxide compound and a polyfunctional acrylate oligomer synthesized from a polyfunctional acrylate and β-ketoester, β-diketone, β-ketoamide or β-ketoanilide. It is about.

The information provided below is not provided as a prior art for the present invention, but merely to aid the reader in understanding.

Acrylate, methacrylate and other unsaturated monomers are widely used in coatings, adhesives, sealants and elastomers, and can be crosslinked by free radical curing, which is either crosslinked by ultraviolet light in the presence of photoinitiators or initiated by peroxides. Typically, such photoinitiators and / or peroxides are low molecular weight multifunctional compounds that can be volatilized or readily absorbed through the skin and can have detrimental effects on health. Functionalized oligomeric photoinitiators can overcome some of these drawbacks. In general, polymeric photoinitiators are nonvolatile compounds and are not readily absorbed through the skin. However, multistage synthesis may be required, low functionality may be detrimental to reactivity and final properties, and catalysts or initiators may still be needed to achieve crosslinking.

Michael addition of acetoacetate donor compounds to polyacrylate acceptor compounds has been described in the literature to produce crosslinked polymers. For example, Mozner and Rheinberger reported the Michael addition of acetoacetate to triacrylate and tetraacrylate (16 Macromolecular Rapid Communications 135 (1995)). The product formed was a crosslinked gel. One of these reactions is shown in FIG. 1, where Mozner has one mole of trimethylol propane triacrylate (TMPTA) having three functional groups polyethylene glycol (molecular weight 600) diacetoacetate (PEG600-DAA) having two functional groups 1 mole was added (since each acetoacetate "functional group" reacted twice, so the reaction equivalent weight per mole of diacetoacetate was 4). The resulting network is considered "gelled" or cured despite the presence of unreacted acrylic functional groups. Additional reactions may be promoted, but the network is effectively crosslinked and cannot be made liquid by heat or solvent

In the reaction, the molar ratio of TMPTA to PEG 600 DAA is 1: 1, the ratio of the number of acrylate functional groups to the number of acetoacetate functional groups is 3: 2, and the ratio of reaction equivalents is 3: 4. It may be characterized as described.

U.S. Pat.Nos. 5,945,489 and 6,025,410 to Moy et al. And assigned to the assignee of the present invention, Ashland Inc., disclose β-dicarbonyl donor compounds (e.g. acetoacetate). It is disclosed that certain organic soluble liquid non-crosslinking oligomers prepared by one-step Michael addition of polyacrylates can be further crosslinked by ultraviolet light without expensive photoinitiators. The oligomers disclosed above may be described as self-photoinitiating acrylate resins. In addition, when the polyacrylate acceptor compound and the β-dicarbonyl donor compound are combined in precise proportions in the presence of a basic catalyst, a liquid oligomer composition is produced. Crosslinked gels or solid products are obtained when ratios below the ranges disclosed in the above mentioned patent documents are used. In addition, the liquid oligomer compositions disclosed above may be readily applied to various substrates prior to ultraviolet light curing, for example by conventional coating techniques using rolls or sprays.

As used herein, the term “monomer” typically contains carbon, has a relatively low molecular weight, simple structure, and can be converted into a polymer, synthetic resin, or elastomer by combination with other similar and / or dissimilar molecules or compounds. Defined as a molecule or compound.

As used herein, the term "oligomer" is defined as a polymer molecule consisting of only a few similar and / or dissimilar monomer units.

As used herein, the term "resin" is defined as an oligomer that can be converted to a high molecular weight polymer by combination with other similar and / or dissimilar molecules or compounds.

As used herein, the term “thermal curing” is defined as a high molecular weight polymer product of a resin that is irreversibly solidified or cured upon heating. This property is associated with the crosslinking reaction of molecular components induced by heat, irradiation and / or chemical catalysis.

An application assigned to the assignee of the present invention and co-pending with this application (agent control number 20435/0141) discloses a dual curing thiylene system comprising a self-initiating acrylate resin crosslinked with a multifunctional thiol (above) The specific full text of the literature is incorporated herein by reference for any purpose).

The usefulness of an acrylate-based resin system is limited by its relatively poor adhesion to metal substrates. Adhesion to the metal can be enhanced by the use of cationic-cured aliphatic epoxy compounds.

Summary of the Invention

We have shown that addition of suitable cycloaliphatic epoxides to the polyacrylate resins disclosed above in the presence of a suitable cationic initiator results in a coating with much better surface hardening and improved adhesion, hardness and mar resistance. do.

The present invention provides a dual curing polymer resin composition. Coatings, adhesives, sealants and inks can be prepared using the resins of the invention that are cured by two different mechanisms. The first mechanism is the UV-initiated glass-radical polymerization of Michael addition resins with pendant acrylate functional groups. A second mechanism called cationic curing provides UV-initiated acid polymerization of epoxy resins catalyzed by photo-generated strong acids. In the cationic curing process, the cationic photoinitiator is decomposed by UV light to produce Lewis or Bronsted strong acid. The cationic photoinitiator is preferably a perfluorometallate onium salt.

The present invention includes bifunctional alicyclic epoxides and organic soluble, ungelled and uncrosslinked Michael addition resins wherein the Michael resin is a multifunctional acrylate Michael acceptor and a β-dicarbonyl Michael donor, specifically Provided are liquid oligomeric compositions formed from, but not limited to, β-ketoesters, β-diketones, β-ketoamides, cyanoacetates, or β-ketoanilides, or combinations thereof.

The present invention is stable upon storage for more than 1 month, has residual pendant unsaturated acrylate groups (as opposed to unsaturated groups in the oligomer "backbone" as obtained in the preparation of unsaturated polyester resins) and upon exposure to UV radiation. It provides a liquid oligomer composition that is photopolymerized very quickly.

The present invention optionally further comprises one or more additives selected from the group consisting of pigments, gloss modifiers, glidants, planarizers and other suitable additives for formulating coatings, paints, laminates, sealants, adhesives and inks. It provides a liquid oligomer composition. A general reference for initiating the additive is excellent in the literature [The Encyclopedia of Polymer Science and Engineering , 2 nd Edition, Wiley- Interscience Publications (1985)].

The present invention provides a multifunctional acrylate Michael acceptor and a β-dicarbonyl Michael donor, reacting the donor with a acceptor using a basic catalyst to form a Michael adduct, and adding an acidifying agent to any remaining residues. A method of preparing a liquid oligomer composition having residual pendant unsaturated acrylate groups, comprising neutralizing the basic species of, and mixing at least one cycloaliphatic epoxide.

The present invention provides in one aspect a liquid oligomer composition further comprising at least one modified epoxide. The modified epoxide is selected to improve the film properties of the cured coating, for example adhesion to metals, and / or to reduce the viscosity of the coating for application purposes. Michael polyacrylate resin / epoxide double cure systems can improve “green strength” or “blocking resistance” using mild UV pulses or very small amounts of amine or peroxide catalyst. Once the first step or initial level of curing has been achieved, the coating can be molded, printed, or laminated to prior to complete curing. Thus, the ability to double cure allows the substrate to be manufactured in a way that conventional systems, including conventional UV-cured coatings and the like, cannot mimic.

The present invention provides a liquid oligomer composition comprising a cycloaliphatic epoxide and an organic soluble, ungelled and uncrosslinked Michael addition polyacrylate reaction product, applying the oligomer composition to a surface, and applying the composition It provides a method of using a liquid oligomer composition comprising the step of curing in the presence of a cationic photoinitiator and actinic light.

The present invention provides in one aspect a thermoset formed from the oligomeric composition of the present invention.

The invention further comprises at least one additive selected from the group consisting of pigments, gloss modifiers, glidants, planarizers and other suitable additives for formulating coatings, paints, laminates, sealants, adhesives and inks. It provides a method of using a liquid oligomer composition.

One aspect of the present invention further provides oligomeric compositions that can be crosslinked to produce coatings (eg, paints, varnishes), inks, laminates, sealants, adhesives, elastomers, and composite matrices.

The present invention provides a polymerization product comprising an alicyclic epoxide and an organic soluble, ungelled and uncrosslinked Michael addition polyacrylate reaction product, further crosslinked in the presence of a cationic photoinitiator.

The invention is best understood when considered in conjunction with the accompanying drawings, in which: In accordance with conventional practice, various parts of the drawings are not drawn to scale. On the contrary, the dimensions of the various parts are arbitrarily enlarged or reduced for clarity. The present application includes the following drawings.

1 is a schematic of the synthesis of crosslinked Michael polyacrylate gels.

2 is a schematic diagram of the synthesis of UV-curable oligomers formed by Michael addition reaction of trimethylolpropane triacrylate (TMPTA) and ethyl acetoacetate (EAA).

The accompanying drawings, however, are merely illustrative of exemplary embodiments of the invention and should not be considered as limiting the scope of the invention, the invention may allow other embodiments that are equally effective.

Reference is made to the drawings to illustrate selected embodiments of the invention and preferred ways of carrying out the invention. It should be understood that the present invention is not limited only to the aspects shown in these figures.

One aspect of the invention provides a liquid oligomer composition comprising a cycloaliphatic epoxide, a cationic photoinitiator, and a mixture of organic soluble, ungelled, and uncrosslinked Michael addition polyacrylate reaction products in a controlled proportion. Michael addition polyacrylate oligomers are formed from multifunctional acrylate Michael acceptors and β-dicarbonyl Michael donors. β-dicarbonyl michael donors are suitably selected from β-ketoesters, β-diketones, β-ketoamides and β-ketoanilides. Multifunctional acrylate Michael acceptors are suitably selected from diacrylates, triacrylates and tetraacrylates. The range of β-dicarbonyl donors and multifunctional acrylate acceptors provides composition constructors with the opportunity to exercise a significant range of selectivity for the properties of the final product. The properties of the final crosslinked product can be varied in a controlled manner using different oligomers, different epoxides, and / or varying the ratio of Michael oligomer: epoxide.

Preferred diacrylates include ethylene glycol diacrylate, propylene glycol diacrylate, diethylene glycol diacrylate, dipropylene glycol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, tetraethylene, glycol Diacrylate, tetrapropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, ethoxylated bisphenol A diacrylate, bisphenol A diglycidyl ether diacrylate, resorcinol diglyci Dyl ether diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate Latex, cyclohexane dimethanol diacrylate, ethoxylated neophene Glycol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated cyclohexanedimethanol diacrylate, propoxylated cyclohexanedimethanol diacrylate, epoxy diacrylate, aryl urethane diacrylate, aliphatic urethane diacrylate Acrylates, polyester diacrylates, and mixtures thereof, but are not limited thereto.

Preferred triacrylates include trimethylol propane triacrylate, glycerol triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, tris (2-hydroxyethyl) isocyanurate tri Acrylate, ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate, pentaerythritol triacrylate, aryl urethane triacrylate, aliphatic urethane triacrylate, melamine triacrylate, epoxy novolac triacrylate, aliphatic Epoxy triacrylate, polyester triacrylate, mixtures thereof, and the like, but is not limited thereto.

Preferred tetraacrylates include di-trimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, ethoxylate Silylated dipentaerythritol tetraacrylate, propoxylated dipentaerythritol tetraacrylate, aryl urethane tetraacrylate, aliphatic urethane tetraacrylate, polyester tetraacrylate, melamine tetraacrylate, epoxy novolac tetraacrylate and Mixtures thereof, and the like, but are not limited thereto.

In a preferred embodiment, the β-dicarbonyl michael donor is β-diketone (eg 2,4-pentanedione). Suitably, the present invention provides β-ketoesters (eg ethyl acetoacetate), β-ketoanilides (eg acetoacetanilide) or β-ketoamides (eg acetoacetamide) or the desired resin quality. And mixtures of Michael donors according to the end use. In a preferred embodiment of the invention, β-dicarbonyl has a functionality (N) with N = 2. Β-dicarbonyl donors of higher functionality (eg N = 4, 6 ...) are suitable, but finer control of the reaction stoichiometry must be carried out to avoid unwanted system gelation.

Suitable β-dicarbonyl donor compounds having a functionality of 2 include ethyl acetoacetate, methyl acetoacetate, 2-ethylhexyl acetoacetate, lauryl acetoacetate, t-butyl acetoacetate, acetoacetanilide, N-alkyl acetoacetanilide , Acetoacetamide, 2-acetoacetosylethyl acrylate, 2-acetoacetosylethyl methacrylate, allyl acetoacetate, benzyl acetoacetate, 2,4-pentanedione, isobutyl acetoacetate and 2-methoxyethyl aceto Acetates and the like, but are not limited thereto.

Suitable β-dicarbonyl donor compounds having a functionality of 4 include 1,4-butanediol diacetoacetate, 1,6-hexanediol diacetoacetate, neopentyl glycol diacetoacetate, cyclohexane dimethanol diacetoacetate and ethoxylated Bisphenol A diacetoacetate and the like, but are not limited thereto.

Suitable β-dicarbonyl donor compounds having a functionality of 6 include, but are not limited to, trimethylol propane triacetoacetate, glycerin triacetoacetate and polycaprolactone triacetoacetate.

Preferred β-dicarbonyl donor compounds having a functionality of 8 include, but are not limited to, pentaerythritol tetraacetoacetate.

Michael addition reactions can be catalyzed by strong bases. Preferred bases are diazabicycloundecene (DBU) that are sufficiently strong and readily soluble in the monomer mixture. Other cyclic amidines such as diazabicyclononene (DBN) and guanidine are also suitable for catalyzing the polymerization. Group I alkoxide bases such as potassium tert-butoxide are typically suitable for promoting the desired reaction if they are sufficiently soluble in the reaction medium. Quaternary hydroxides and alkoxides, such as tetrabutyl ammonium hydroxide or benzyltrimethyl ammonium methoxide, include another class of preferred base catalysts for promoting Michael addition reactions. Finally, strong lipophilic alkoxide bases can be produced in situ from the reaction of a halide anion (eg, quaternary halide) with an epoxide moiety. Such in situ catalysts are assigned to Atsland Inc., the assignee of the present application and disclosed in application 10 / 255,541, which is co-pending with the present application. The entire contents of application number 10 / 255,541 are incorporated herein by reference in their entirety for all purposes.

Reactive pendant meta which can be crosslinked in subsequent curing reactions by Michael addition of methacrylate-functional β-dicarbonyl compounds such as 2-acetoacetoxyethyl methacrylate (AAEM) to the diacrylate monomers Liquid polyacrylates having acrylate groups are obtained. Because acrylate and acetoacetate are mutually reactive and methacrylate is essentially inert under the conditions of the desired Michael addition reaction, highly functionalized (one methacrylate per repeating unit) liquid non-crosslinkable oligomers at ambient temperature It can be obtained in one step solventless reaction.

The present invention has the advantage that no solvent is required. However, the high selectivity of the Michael reaction allows the use of monomers such as styrene and methyl methacrylate as inert solvents, providing a low-viscosity system that is easily incorporated into a variety of laminated resins. Suitable non-reactive solvents include styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, vinyl acetate, allyl acetate, allyl methacrylate, diallyl phthalate, C ₁ -C ₁₈ -methacrylate esters, dimetha Acrylates and trimethacrylates include, but are not limited to.

The present invention provides a resin having residual pendant unsaturated acrylate groups. Residual pendant unsaturation means that the polymerizable acrylic group is maintained by careful control of the reactant stoichiometry. That is, there are more acrylic groups than the reactive sites on the Michael donor. Due to the nature of the addition reaction, the pendant (as opposed to being present as part of the "backbone" in the bonded structure on both sides) causes the acrylic group to be far from the Michael addition site. Pendant acrylic groups are useful for free radical polymerization, further Michael addition crosslinking or for example "similar Michael addition" with amines. Quasi-Michael reactions of adding thiol-enes with mercaptans upon UV exposure are disclosed in a co-pending application (agent control number 20435/0141), the specific entire disclosure of which is for any purpose. Incorporated herein by reference. Pendant acrylate groups of Michael polyacrylate resins are also useful for crosslinking by free radical mechanisms in the presence of strong acid-generating cationic photoinitiators, since free radicals are formed by photolysis processes.

In the examples below, all parts are by weight unless otherwise indicated.

An example of synthesis of a Michael polyacrylate resin (also referred to as Michael oligomer, Michael adduct or Michael adduct product) is shown in FIG. 2. 59.2 g of trimethylolpropane triacrylate (TMPTA) and 0.4 g of diazabicycloundecene (DBU) were metered into a 500 ml 3-neck round bottom flask equipped with a mechanical stirrer and addition furnace. 13.0 g of ethyl acetoacetate (EAA) were metered into the addition furnace. TMPTA and DBU were mixed for 5 minutes before adding EAA. EAA was then added to the stirred TMPTA / DBU mixture over 15 minutes. After the solution was warmed to 54 ° C., the addition of EAA was complete. After the exothermic reaction settled in 100 minutes, a viscous yellow liquid was obtained and did not gel on standing.

The same general procedure can be used for various combinations of acrylate and β-dicarbonyl Michael donors, provided that the equivalent ratio of acrylate to Michael donor should be sufficient to obtain a liquid uncrosslinked product. Particularly in the case of exothermic or large scale reactions, it is necessary to gradually control the addition of the Michael donor and / or to cool the reaction in order to prevent premature crosslinking of the acrylate function initiated by heat.

The present invention provides, in one aspect, a dual curing mechanism. The cycloaliphatic epoxide compound is added to the Michael acrylate resin by a suitable cationic photoinitiator. Cationic photoinitiators are onium compounds that photodegrade when excited by ultraviolet (UV) light. Photo-dissociation of various onium species yields Lewis acids or Bronsted acids. (Koleske, J. V., Radiation Curing of Coatings, ASTM Manual 45, (2002)). As part of the photolysis process, free radicals are formed that can catalyze the polymerization of ethylenically unsaturated compounds present in the resin. Polymerization of the epoxide with ethylenically unsaturated compounds is catalyzed by strong acids dissociated upon photolysis of the onium photo-initiator.

Cationic photoinitiators of the present invention are onium salts that decompose upon UV-irradiation to form strong acids. More specifically, photoinitiators include aryl sulfonium metal salts, aryl iodonium metal salts and aryl phosphonium metal salts. These and other cationic photoinitiators are described in Chapter III on "Phtoinitiators for Cationic Polymerisation," by J. V. Crivello AND K. Dietliker, Wiley / SITA Series in Surface Coatings Technology, Vol. III, G. Bradley, Ed., John Wiley and Sons Ltd., Chichester, England, 1998, p. 329. It is understood that the cited onium salts are non-limiting examples of suitable and preferred cationic photoinitiators. Those skilled in the art are familiar with other suitable cationic photoinitiators or will be able to determine them with minimal experimentation.

Examples of aryl sulfonium cations are triarylsulfonium (eg triphenylsulfonium) cations. It is understood that triaryl sulfonium cations exist as complex mixtures of aryl sulfonium salts. The term "triaryl sulfonium" is used herein to mean an aryl sulfonium species and / or a complex mixture of any one of the above species.

An example of an aryl iodonium cation is a diaryliodonium (eg diphenyliodonium) cation. It is understood that diaryliodonium cations exist as complex mixtures of diaryliodonium salts. The term "diaryliodonium" is used herein to mean an aryl iodonium species and / or a complex mixture of any one of the above species.

Examples of aryl phosphonium cations are tetraarylphosphonium (eg, tetraphenylphosphonium) cations. It is understood that the tetraarylphosphonium cation is a complex mixture of tetraarylphosphonium salts. The term “tetraarylphosphonium” is used herein to mean an aryl phosphonium species and / or a complex mixture of any one of these species.

The non-onium cationic photoinitiator consists of an onium cation complexed with a pseudo-metallic anion (X ⁻ ), preferably a polyarylonium cation. Preferred pseudo-metallic anions are perfluorometallate anions. Suitable quasi-metal anions (X ^_ ) are known in the art. Suitable and preferred quasi- Examples of the metal anion is _{^{BF 4 -, PF 6 -,}} SbF 6 - and _{B (C 6 F 5) 4} - , but is not limited to this.

Cationic photoinitiators of the invention also include organometallic compounds such as iron arene salts, zirconocene salts or manganese decacarbonyl salts. Suitable organometallic compounds are disclosed in Koleske, JV, Radiation Curing of Coatings, ASTM Manual 45 (2002).

Michael addition reactions are catalyzed by strong bases such as diazabicycloundecene (DBU). After the Michael reaction, it is preferred to add an acidulant to react and neutralize the base. Suitable acidifying agents include, but are not limited to, phosphoric acid, carboxylic acids, acid half esters and inorganic acid esters (eg, hydroxyethyl methacrylate phosphate or hydroxyethyl acrylate phosphate). Do not. The acidifying agent is preferably added in an amount more than stoichiometric with respect to the base. However, although acidifying agents can be added in stoichiometric excess, this can cause problems of storage stability.

Prior to curing, the reactants are mixed at any point in time to form a stable homogeneous mixture, provided that there are no basic species (e.g., amines, alkoxides, phenoxides, etc.) capable of catalyzing crosslinking. . Storage stability, in which quality is defined as the absence of premature gelling (ie curing) and minimal increase in resin viscosity, can be achieved if the system is properly "acidified" and the mixture is kept from exposure to actinic light. There is no "benchmark" established in this regard. The criteria for acceptance are defined by the end user.

Epoxides suitable for the purposes of the present invention can be selected by those skilled in the art from a wide range of commercially available epoxides. The choice of epoxide is determined by the properties desired for the final cured product to retain. For crosslinking, the epoxide must be at least bifunctional. Preferred bi-functional epoxides are bis- (3,4-epoxycyclohexyl) adipates. More preferred 2-functional epoxides are 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylates. Compounds having two or more epoxide functional groups are also suitable for the purposes of the present invention.

Epoxides suitable for the present invention have a Brookfield viscosity at 25 ° C. of less than about 1,000 cP. Suitable epoxides impart strong adhesion to the metal upon curing. One skilled in the art can readily determine appropriate values of adhesion by ASTM D3359 methods known in the art, among other tests. Suitable epoxides are single phase liquids that are transparent under standard temperature and pressure. In addition, suitable epoxides are stable as defined by their minimal tendency to separate or react with the mixed Michael oligomers.

By including a "modified epoxide" the properties of the final composition can be suitably modified. Epoxides suitable as modifiers include limonene monooxide, diglycidyl ether of bisphenol A and epoxy phenol novolacs. Diglycidyl ethers of bisphenol A and epoxy phenol novolacs are not considered alicyclic epoxides. However, they are suitable for the purpose of the present invention.

Ultraviolet light photopolymerization has been demonstrated by applying a portion of the composition of the present invention to a surface. The composition was spread on the surface to a thickness of about 3 mils or less. The resin was applied to an aluminum or stainless steel substrate by a "draw down" technique. The specimens were cured with Fusion Systems, Corp. UV curing units using a 600-watt H-bulb and a belt speed of 40 ft / min.

Coating performance is measured by several different assays that are familiar to those skilled in the art. Hardness and chemical resistance were evaluated on aluminum panels, adhesion was evaluated on steel panels, and damage resistance measurements were performed on aluminum panels painted white.

Hardness. Film hardness is the resistance of a coating to withstand cutting, shearing or penetration by hard objects. The method of measuring the hardness of the coating is to scratch the film with a pencil core of known hardness. The results are recorded as the hardest shims that cannot scratch or the film is cut through to the substrate. Although this test method is very subjective, it provides a fast and relatively reliable method for measuring film hardness. Softness <6B-5B-4B-3B-2B-B-HB-F-H-2H-3H-4H-5H-6H>, as measured by the pencil method. The method follows the procedure of ASTM D3363.

Solvent content. Solvent resistance is the resistance of the coating to solvent attack or film deformation. Rubbing the coating with a cloth moistened with a suitable solvent is one assay to assess the time at which a certain level of solvent resistance is achieved. All scraping tests were performed using methyl ethyl ketone (MEK) and employed a double scratching technique, which was a complete scraping of the coated surface back and forth. To standardize the test strength, a cheesecloth was fixed to the rounded end of the 16-ounce round head hammer. The double scratch technique used the weight of the hammer by the operator grasping the bottom of the hammer handle. The test was performed until the film was cut by a double scraping operation or until noticeable film irregularities became apparent. This method is a variation of the procedure of ASTM D4752.

Polish. It measured using the gloss meter. This method follows the procedure of ASTM D523.

Damage resistant. Measurements were made using an Atlas Crockmeter® and 0000 steel wool. The test method used was modified from ASTM D6279, using a panel colored white as a substrate, and measuring 60 ° gloss before and after abrasion. Damage resistance is reported as% gloss retention, defined as (gloss of worn coating / gloss of unworn coating) X 100.

Adhesion was tested using iron phosphated steel Q-panel® as the test coating substrate. (Q-Panel (registered trademark) is a trademark of Q-Panel Lab, Inc., Cleveland, Ohio.) Adhesion test is conducted by Guardco in accordance with the modification method of Test Tape Method B of ASTM D3359. The method was performed by a crosshatch method on a rigid substrate using a Bladeco Blade PA-2054 (11 pieces, 1.5 mm cutter) The test tape used was Permacel # 99. It is recorded as a number from 0B to 5B, with 0B indicating overall failure and 5B showing good adhesion.

Example  One

Novel Michael addition polyacrylate resins based on Michael donor ethyl acetoacetate, 2,4-pentanedione and allyl acetoacetate were synthesized according to the methods described in US Pat. Nos. 5,945,489 and 6,025,410. Michael polyacrylate resins were mixed with various alicyclic epoxides at different levels. Thereafter, the resin / epoxide composition was applied to the phosphated steel substrate and cured at a UV irradiation amount of 1500 mJ / cm ² . All tests were performed for 24 hours after UV irradiation on the cured resin coating to ensure that the so-called "rock curing" of the subsequent epoxy component was completed. The results are reported collectively in Tables I, II and III:

In Table I, Michael addition polyacrylate resin A is reacted with ethyl acetoacetate at a molar ratio of 2.2: 1 to total acceptor: donor and is neutralized by Ebecryl 168 (hydroxyethyl methacrylate phosphate). 75/25 mole blend of diacrylate (HDDA) and trimethylolpropane triacrylate (TMPTA). Epoxy compounds are CYRACURE® UVR-6105 and CYRACURE® UVR-6128 (Union Carbide Corp, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, respectively) And bis- (3,4-epoxycyclohexylmethyl) adipate). The photoinitiator used was CD-1010 (Sartomer), a mixture of 50% triarylsulfonium hexafluoroantimonate salt in propylene carbonate. The leveling agent used was Fluorad® FC 4430 (3M Corp.).

Michael addition polyacrylate resin B of Table II reacted with 2,4-pentanedione at a molar ratio of 2.2: 1 and neutralized by ebecryl 168, HDDA and Laromer PE 55 F (BASF, 94.4 / 5.6 mole blend of polyester acrylate with a molecular weight of about 1000).

Michael addition polyacrylate resin C of Table III was dipropylene glycol diacrylate, reacted with ethyl acetoacetate in a molar ratio of 2.2: 1 and neutralized by ebecryl 168.

The results in Tables I, II and III demonstrate that the performance benefits of UV irradiated cured coatings of Michael addition polyacrylate resins and UV irradiated cured coatings of epoxy compounds can be obtained by a combination of the two. .

Example  2

Michael addition polyacrylate resins based on HDDA and TMPTA (75:25 ratio) and ethyl acetoacetate were synthesized according to the methods described in US Pat. Nos. 5,945,489 and 6,025,410. This resin was mixed with Uvacure 1562 (an acrylate-alicyclic epoxide blend having both acrylate and epoxy functionalities). Thereafter, the mixture was applied to a phosphated steel substrate and cured at a UV irradiation amount of 1500 mJ / cm ² . Adhesiveness, solvent resistance, pencil hardness, gloss and damage resistance are as described in the beginning of the examples. As described in Example 1, all tests were performed for 24 hours after UV irradiation.

The use of double cured or “hybrid cured” coating systems is similar to the use of standard coatings, ie, substrate protection and / or decorative applications. However, using dual curability, the final film properties can be developed to a wider range than conventional coating techniques. As characterized by film hardness and solvent resistance, for example, complete curing is achieved with UV radiation of 500 mJ / cm 2 (or less), compared to 30 minutes of high temperature baking time for alkylated or melamine based coatings. The same weak intensity can be achieved in seconds. In stark contrast to conventional UV-based coatings, the Michael polyacrylate resin / epoxide double cure system utilizes a mild UV pulse or a very small amount of amine or peroxide catalyst to "hold strength" or "blocking resistance". Can improve. Once the first step or initial level of curing has been achieved, the coating can be molded, printed, or laminated to prior to complete curing. Once fully cured, many coatings become more difficult to bend or mold and / or they do not adhere well during molding operations. Thus, the ability to double cure allows the substrate to be manufactured in a way that conventional systems, including conventional UV-cured coatings and the like, cannot mimic.

Monoacrylates can be used for the appropriate resin properties required. For example, addition of up to 25 mole percent monofunctional acrylates (eg isobornyl acrylate, IBOA) allows the coating to be "tough" without increasing brittleness through more crosslinking. Other monofunctional monomers, ethoxyethoxy ethyl acrylate (EOEOEA) or dodecyl acrylate, can be used to mitigate film adhesion to substrates having heterogeneous surface energy, or pigments, nanoparticles, waxes, or silicone coating formulations. It can be added to increase the incorporation into. Suitable monoacrylates include simple C ₁ -C ₁₈ acrylate esters, isobornyl acrylate (IBOA), tetrahydrofurfuryl acrylate (THFFA), 2- (2-ethoxyethoxy) ethyl acrylate (EOEOEA ), Phenoxyethyl acrylate (PEA), hydroxyalkyl acrylate, monoalkyl polyalkylene glycol acrylate, siloxane, silane or silicone acrylate, perfluoroalkyl acrylate, caprolactone acrylate and mixtures thereof And the like, but not limited thereto.

Inclusion of References

All publications, patent documents, patent applications, and ASTM test methods mentioned herein specifically and individually refer to each publication, patent document, patent application, and ASTM test method for reference and for any and all purposes. Included as indicated for inclusion by reference, ASTM test methods are specifically and individually described as incorporated by reference. In case of conflict, the present specification will control. In particular, the full text of pending applications (number not yet assigned, Agent Control Numbers 20435/141, 20435/144, 20435/146, 20435/147 and 20435/148) co-pending with this application is hereby incorporated by reference for any purpose. Is introduced.

Claims (53)

Alicyclic epoxides, and Michael addition polyacrylate reaction product that is organic soluble, ungelled and not crosslinked Liquid oligomer composition comprising a. The liquid oligomer composition of claim 1, wherein the Michael addition polyacrylate product is formed from a multifunctional acrylate Michael acceptor and a β-dicarbonyl Michael donor. The liquid oligomer composition of claim 1, wherein the β-dicarbonyl michael donor is selected from the group consisting of β-ketoesters, β-diketones, β-ketoamides, β-ketoanilides, and mixtures thereof. The liquid oligomer composition of claim 1, wherein said multifunctional acrylate michael acceptor is selected from the group consisting of diacrylates, triacrylates and tetraacrylates. The liquid oligomer composition of claim 1, wherein the β-dicarbonyl michael donor is β-diketone or β-ketoester. The liquid oligomer composition according to claim 3, wherein the equivalent functionality (N) of the β-dicarbonyl is 2, 4, 6, or 8. The molar ratio of acrylic functional group of said diacrylate Michael acceptor to said β-dicarbonyl donor is When the β-dicarbonyl functionality is 2, ≥ 1: 1, When the β-dicarbonyl functionality is 4, ≧ 4.5: 1, When the β-dicarbonyl functionality is 6, ≧ 4.5: 1, When the β-dicarbonyl functionality is 8, ≧ 3.5: 1 Liquid oligomer composition. The molar ratio of acrylic functional group of said triacrylate Michael acceptor to said β-dicarbonyl donor is When the β-dicarbonyl functionality is 2, ≧ 2.25: 1, When the β-dicarbonyl functionality is 4, ≥ 6.4: 1, When the β-dicarbonyl functionality is 6, ≥ 7.8: 1 When the β-dicarbonyl functionality is 8, ≥ 7.4: 1 Liquid oligomer composition. The molar ratio of acrylic functional group of the tetraacrylate Michael acceptor to the β-dicarbonyl donor is When the acetoacetate functionality is 2, ≥ 6.6: 1, When the β-dicarbonyl functionality is 4, ≥ 12.3: 1, When the β-dicarbonyl functionality is 6, ≧ 13.2: 1 When the β-dicarbonyl functionality is 8, ≥ 12.7: 1, Liquid oligomer composition. The liquid oligomer composition of claim 1, wherein the cycloaliphatic epoxide has a Brookfield viscosity at 25 ° C. of less than 1,000 cP. The liquid according to claim 10, wherein the alicyclic epoxide is selected from the group consisting of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate and bis- (3,4-epoxycyclohexyl) adipate. Oligomer composition. The liquid oligomer composition of claim 1, further comprising a modified epoxide. 13. The liquid oligomer composition of claim 12, wherein the modified epoxide is selected from the group consisting of limonene monooxide, diglycidyl ether of bisphenol A, and epoxy phenol novolac. The liquid oligomer composition according to claim 11, wherein the preferred alicyclic epoxide is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate. The liquid oligomer composition of claim 1, wherein the Michael addition reaction is carried out in the presence of a strong base. The alkoxy produced in situ by reaction of cyclic amidine, guanidine, group I alkoxide, quaternary hydroxide, quaternary alkoxide, and halide anion with an epoxy moiety. Liquid oligomer composition selected from the group consisting of de bases. The liquid oligomer composition of claim 14, wherein said base is selected from the group consisting of diazabicycloundecene (DBU), diazabicyclononene (DBN), and 1,1,3,3-tetramethyl guanidine. 15. The liquid oligomer composition of claim 14, wherein said alkoxide is produced in situ by reaction of a quaternary halide with an epoxide moiety. The method of claim 4, wherein the diacrylate is ethylene glycol diacrylate, propylene glycol diacrylate, diethylene glycol diacrylate, dipropylene glycol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate. Acrylate, tetraethylene glycol diacrylate, tetrapropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, ethoxylated bisphenol A diacrylate, bisphenol A diglycidyl ether diacrylate, les Sorcinol diglycidyl ether diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate Neopentyl glycol diacrylate, cyclohexane dimethanol diacrylate, ethoxyl Neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated cyclohexanedimethanol diacrylate, propoxylated cyclohexanedimethanol diacrylate, acrylated epoxy diacrylate, aryl urethane diacrylate, Liquid oligomer composition selected from the group consisting of aliphatic urethane diacrylate, polyester diacrylate and mixtures thereof. The method of claim 4, wherein the triacrylate is trimethylol propane triacrylate, glycerol triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, tris (2-hydroxyethyl) Isocyanurate triacrylate, ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate, pentaerythritol triacrylate, aryl urethane triacrylate, aliphatic urethane triacrylate, melamine triacrylate, aliphatic epoxy tri Liquid oligomer composition selected from the group consisting of acrylates, epoxy novolac triacrylates, polyester triacrylates and mixtures thereof. The method of claim 4, wherein the tetraacrylate is di-trimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, dipentaerythritol Tetraacrylate, ethoxylated dipentaerythritol tetraacrylate, propoxylated dipentaerythritol tetraacrylate, aryl urethane tetraacrylate, aliphatic urethane tetraacrylate, polyester tetraacrylate, melamine tetraacrylate, epoxy furnace Liquid oligomer composition selected from the group consisting of volac tetraacrylate and mixtures thereof. 7. The β-dicarbonyl donor compound of claim 6, wherein the β-dicarbonyl donor compound having a functional value of 2 is ethyl acetoacetate, methyl acetoacetate, 2-ethylhexyl acetoacetate, lauryl acetoacetate, t-butyl acetoacetate, acetoacetanilide, N The group consisting of -alkyl acetoacetanilide, acetoacetamide, 2-acetoacetosylethyl methacrylate, allyl acetoacetate, benzyl acetoacetate, 2,4-pentanedione, isobutyl acetoacetate and 2-methoxyethyl acetoacetate Liquid oligomer composition selected from. 7. The β-dicarbonyl donor compound of claim 6, wherein the β-dicarbonyl donor compound having a functionality of 4 is 1,4-butanediol diacetoacetate, 1,6-hexanediol diacetoacetate, neopentyl glycol diacetoacetate, cyclohexane dimethanol dia A liquid oligomer composition selected from the group consisting of cetoacetate and alkoxylated bisphenol A diacetoacetate. The liquid according to claim 6, wherein the β-dicarbonyl donor compound having a functional value of 6 is selected from the group consisting of trimethylol propane triacetoacetate, glycerin triacetoacetate and polycaprolactone triacetoacetate, and alkoxylated derivatives thereof. Oligomer composition. The liquid oligomer composition according to claim 6, wherein the β-dicarbonyl donor compound having a functional value of 8 is pentaerythritol tetraacetoacetate and an alkoxylated derivative thereof. The liquid oligomer composition of claim 2, wherein the Michael addition reaction occurs in the presence of at least one non-reactive solvent. The method of claim 24, wherein the non-reactive solvent is styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, vinyl acetate, allyl acetate, allyl methacrylate, diallyl phthalate, C ₁ -C ₁₈ -methacryl Liquid oligomer composition selected from the group consisting of late esters, dimethacrylate and trimethacrylate. The liquid oligomer composition of claim 1, which is stable upon storage for more than one month and has pendant unsaturated acrylate groups. The liquid oligomer composition of claim 2, further comprising an acidifying agent. 30. The liquid oligomer composition of claim 29, wherein said acidifying agent is selected from the group consisting of phosphoric acid, carboxylic acid, acid half ester, and inorganic acid ester. 32. The method of claim 30 wherein the preferred acidifying agent is 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate And phosphate esters of 4-hydroxybutyl methacrylate. The liquid oligomer composition of claim 2, further comprising monoacrylate. 33. The method of claim 32, wherein the monoacrylate is a simple C ₁ -C ₁₈ acrylate ester, isobornyl acrylate (IBOA), tetrahydrofurfuryl acrylate (THFFA), 2- (2-ethoxyethoxy) Ethyl acrylate (EOEOEA), phenoxyethyl acrylate (PEA), hydroxyalkyl acrylate, monoalkyl polyalkylene glycol acrylate, siloxane, silane or silicone acrylate, perfluoroalkyl acrylate, caprolactone acrylic Liquid oligomer composition selected from the group consisting of a rate and mixtures thereof. 33. The liquid oligomer composition of claim 32, wherein said monoacrylate is present from about 0 to about 50 mole percent. 33. The liquid oligomer composition of claim 32, wherein said monoacrylate is present from about 0 to about 25 mole percent. 33. The liquid oligomer composition of claim 32, wherein said monoacrylate is present from about 0 to about 12.5 mole percent. 3. The liquid oligomer composition of claim 2, further comprising a free-radical source. 38. The liquid oligomer composition of claim 37, wherein said free-radical generator comprises a peroxide. 38. The liquid oligomer composition of claim 37, wherein the peroxide is selected from the group consisting of benzoyl peroxide, methyl ethyl ketone peroxide (MEKP), tert-butyl perbenzoate (TBPB), cumyl peroxide and t-butyl peroxide. . <Claim 39> The liquid oligomer composition of claim 2, further comprising a cationic photoinitiator. 40. The liquid oligomer composition of claim 39, wherein the cationic photoinitiator is selected from the group consisting of perfluorometallate onium salts, iron arene salts, zirconocene salts and manganese decacarbonyl salts. 40. The method of claim 39 wherein the metal acrylate with the BF ₄ perfluoroalkyl ^{_{-, PF 6 -, SbF 6}} - and _{B (C 6 F 5) 4} - anions selected from the group consisting of liquid oligomeric composition. 40. The liquid oligomer composition of claim 39, wherein the onium is a cation selected from the group consisting of aryl sulfonium cations, aryl iodonium cations, and aryl phosphonium cations. The liquid oligomer composition of claim 2, further comprising at least one additive. 44. The liquid oligomer composition of claim 43, wherein said additive is selected from the group consisting of pigments, gloss modifiers, glidants, planarizers and other suitable additives for formulating coatings, paints, laminates, sealants, adhesives and inks. A cured polymerization product from an alicyclic epoxide, a cationic photoinitiator, and a liquid oligomer composition comprising an organic soluble, non-gelled, uncrosslinked Michael addition polyacrylate reaction product. The cured polymerization product from the liquid oligomer composition of claim 43 further comprising a free-radical source. 45. The polymerization product of claim 44, wherein said free-radical source is actinic light. 46. The polymerization product of claim 45, wherein said free-radical generator is a peroxide. 46. The method of claim 45, further comprising at least one additive selected from the group consisting of pigments, gloss modifiers, glidants, planarizers and other suitable additives for formulating coatings, paints, laminates, sealants, adhesives and inks. Polymerization product comprising. Reacting the multifunctional acrylate Michael acceptor and the β-dicarbonyl Michael donor in the presence of a strong base to form a Michael adduct, Adding an acidifying agent to the adduct in an amount greater than or equal to stoichiometry for the base, Mixing the cycloaliphatic epoxide, and Mixing the cationic photoinitiator Method for producing a liquid oligomer composition having a pendant unsaturated acrylate group, comprising. Providing a liquid oligomeric composition comprising an alicyclic epoxide, a cationic photoinitiator, and an organic soluble, ungelled, uncrosslinked Michael addition polyacrylate reaction product, Applying the oligomeric composition to a surface, and Curing the composition A method of using a liquid oligomer composition comprising a. 50. The at least one additive of claim 49 wherein said composition is selected from the group consisting of pigments, gloss modifiers, glidants, planarizers and other suitable additives for formulating coatings, paints, laminates, sealants, adhesives and inks. It further comprises, Method of using the liquid oligomer composition. A substrate coated with the polymerization product of claim 45.

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