TWI782170B - Photocurable coating formulation and joint sealant comprising the same - Google Patents

Abstract

The present disclosure relates to a photocurable coating formulation including: (a) a monomer containing at least one double bond; (b) a modified alkyd resin; (c) a photoinitiator; and (d) a filler. The present disclosure further relates to the use of the coating formulation as a joint sealant.

Description

Light-curing paint formulations and gap fillers containing them

The present invention relates to a photocurable paint formulation and its application, in particular to a photocurable paint formulation applied to caulking adhesives.

Coatings are used in a wide range of applications, ranging from daily necessities to high-tech electronic products, such as furniture, auto parts, cosmetics, and the casings of various 3C electronic products (such as digital cameras, notebook computers, and mobile phones, etc.). Spread over it to provide a protective or decorative finish.

Composite material casing (such as metal/non-metal composite material casing) is composed of two or more different materials, so it has the comprehensive properties of their constituent materials and can alleviate the disadvantages caused by using a single constituent material. However, since the composite material shell is spliced from different materials, seams or grooves will be formed at the joints between the materials, thereby affecting the appearance. Therefore, before coating and baking paint on the composite shell, it is necessary to fill the slits or grooves (including the steps of filling soil and scraping) to make the appearance of the shell smooth.

Polyurethane gap filler (hereinafter referred to as "PU type gap filler") is a commonly used gap filler material. The conventional PU-type caulking method mainly includes the following steps: spray primer on the surface of the composite shell to increase the adhesion of the caulk to the surface of the material, and carry out soil filling and caulking operations after baking and grinding To smooth out the spatial defects of the composite material shell, and then perform steps such as baking and grinding. However, if the space gap at the slits or grooves is too large, it is often necessary to repeat the above steps many times and apply caulking glue many times until the surface is flat before applying base coat and varnish ( top coat) to complete the coating and obtain the desired shell surface.

The above-mentioned painting process is cumbersome, time-consuming and energy-consuming. In particular, in the coating process of the conventional PU-type caulking adhesive, the solvent in the coating of the caulking adhesive needs to be removed. When the thickness of the coating is too thick, it is not easy to dry, and it is easy to cause only the surface layer to dry and the inside to be wet ( Surface dry but not dry inside), and then produce volcanic holes or cracks, etc. Therefore, in order to remove the solvent in the sealant coating, it must be allowed to stand at room temperature for a period of time (usually 2 hours or more) , and then baked at high temperature (usually 80-100°C) for a long time (usually 1 hour or more) to remove residual solvent and cure, the process is cumbersome and time-consuming. In addition, the thickness of the film formed by the above process is usually too high, resulting in a bulky appearance and increasing the weight of the product, and even affecting the assembly tolerance of each part of the product and increasing the production cost. , Thin 3C electronic products cannot meet their needs. What's more, because the PU-type gap filler is more flexible, after the high-temperature and high-humidity weather resistance test or aging test, it is easy to produce line mark defects at the joints of different materials of the composite material (see the box shown in Figure 1 position), which in turn negatively affects the appearance of the product case.

Furthermore, known UV-curable formulations are mostly used as protective or decorative coatings. For example, CN 101654571 A discloses a UV-curable colored paint formulation, which can obtain a coating with both aesthetics and high performance in one spraying application. The UV-curable colored paint formulation includes the following components: (a) An oligomer containing at least one unsaturated double bond; (b) a diluent monomer; (c) a photoinitiator; (d) a thermoplastic acrylic resin; and (e) a colorant. CN 102199377 A provides a photocurable treatment agent, which solves the forming defects of the substrate and removes surface dirt, and provides a coating with a beautiful appearance and good adhesion. The photocurable treatment agent comprises the following composition: (a) a monomer with at least one double bond or an oligomer with at least one double bond or a mixture thereof; (b) a photoinitiator; and (c) a thermoplastic resin. However, the UV-curable/light-curable coating formulations of the above-mentioned prior art are applied to the surface of the substrate of the same material, not the surface of the substrate of the composite material. The height difference problem does not provide any effective solution.

Therefore, how to provide a coating formulation that has good leveling properties and can simplify the coating process for composite materials and obtain a coating with good weather resistance, easy sanding, beautiful appearance and good adhesion has always been a researcher in the technical field. important subject of effort.

After extensive research, the inventors of this case found a light-curing paint formulation that can effectively adhere to the material substrate to be modified (especially those with a height difference) without additional steps such as primer coating and soil filling. Or slit materials, especially composite materials), to modify the space defects on the surface. In addition, after the coating formulation of the present invention is coated, it is cured by exposure to light radiation (such as ultraviolet rays), without long-term standing and baking steps, which not only saves time and energy, but also improves the production capacity per unit time and meets industry needs.

Therefore, the first object of the present invention is to provide a photocurable coating formulation comprising: (a) a monomer containing at least one double bond; (b) a modified alkyd resin; (c) a photoinitiator; and (d) filler particles.

A second object of the present invention is to provide a gap filler comprising the photocurable coating formulation as described herein.

A third object of the present invention is to provide a use of a photocurable coating formulation as described herein as a gap filler.

The photocurable coating formulation of the present invention has the technical effect of filling the space defects on the surface of the material. It is suitable for all kinds of materials that require surface pre-treatment or materials that have undergone preliminary pre-treatment, especially for the surface coating and treatment of 3C electronic products that use composite material casings and have high requirements for appearance and surface properties.

In particular, the photocurable coating formulations of the present invention can provide at least one of the following advantageous properties: ● The paint formulation of the present invention uses light curing, which can shorten the process time (especially, the standing and baking time required by the conventional PU type gap filler coating) and increase the throughput rate, so as to achieve the purpose of energy saving, and The production capacity per unit time is also higher than the known PU-type gap filler process; ● According to the inspection method of ASTM D3359-93, the adhesion of the cured coating is as high as 5B, which is greater than the adhesion of known PU-type gap fillers, so the process of coating the foundation layer and/or primer layer can be omitted , greatly simplify the modification process of the surface of the material; ● The cured coating has good weather resistance and can avoid surface defects such as line marks caused by long-term use.

In some embodiments of the present invention, the photocurable coating formulation of the present invention can further provide at least one of the following advantageous properties: ● When coated on the surface of the material, it exhibits good leveling properties; ● When coated on the surface of the material, it exhibits good sag resistance, which can ensure that the pores or slits deliberately pierced on the material (that is, the pores or slits to be retained) are not filled by the formulation and Does not produce edge accumulation; ● The cured coating has a pencil hardness of H or higher; ● Colorant can be added to make it easier to judge the flatness of the cured coating; ● The cured coating can be re-coated with the photocurable coating formulation or other layers of the present invention; ● The cured coating has good shielding ability to the material.

In summary, by using the light-curable coating formulation of the present invention, not only can the construction process of the conventional gap filler be simplified, but also a coating with good appearance, adhesion and weather resistance and can inhibit the generation of line marks can be prepared , which can effectively solve the problems of the prior art.

Monomers containing at least one double bond

Composition (a) used in the present invention is a monomer containing at least one double bond, which can be cross-linked after being irradiated to form the main body of the coating. Its type is not particularly limited, and is preferably an acrylate monomer.

Acrylate monomers that can be used in the present invention, such as but not limited to: 2-phenoxyethyl acrylate (PHEA), ethoxyethoxyethyl acrylate (EOEOEA), isodecyl acrylate (ISODA) , Isobornyl Acrylate (IBOA), 2-Hydroxyethyl Acrylate (HEA), 2-Hydroxyethyl Methacrylate (HEMA), Dipropylene Glycol Diacrylate (DPGDA), Tripropylene Glycol Diacrylate (TPGDA), 1,6-hexanediol diacrylate (HDDA), diethylene glycol dimethacrylate (DEGDMA), polyethylene glycol (400) diacrylate (PEG (400) DA), polyethylene glycol diacrylate Alcohol (600) ester (PEG (600) DA), ethylene glycol dimethacrylate (EGDMA), ethoxylated (10) bisphenol diacrylate (BPA10EODA), ethoxylated dimethacrylate ( 10) Bisphenol ester (BPA10EODMA), tricyclodecane dimethanol diacrylate (TCDMDA), propoxylated (2) neopentyl glycol diacrylate (NPG2PODA), Nanocryl 0396 (DPGDA containing 50% nano-silicon oxide ), Nanocryl 0768 (HDDA containing 50% nano-silicon oxide), 2-hydroxyethyl methacrylate phosphate (HEMAP), trimethylolpropane triacrylate (TMPTA), triacrylic acid ethoxylate (3) Trimethylolpropane (TMP3EOTA), Ethoxylated (6) Trimethylolpropane Triacrylate (TMP6EOTA), Ethoxylated (9) Trimethylolpropane Triacrylate (TMP9EOTA), Ethoxylated Triacrylate (15 ) trimethylolpropane ester (TMP15EOTA), propoxylated (3) glycerol triacrylate (G3POTA), di-(trimethylolpropane) tetraacrylate (DI-TMPTA), pentaerythritol triacrylate (PET3A ), dipentaerythritol hexaacrylate (DPHA) or a mixture thereof.

Commercially available acrylate monomers that can be used in the present invention include: EM210, EM211, EM219, EM70, EM221, EM223, EM328, EM2308, EM231, EM235, EM2381, EM2382, EM2384, EM2386, EM2387, EM39, EM331, EM3380, EM241 , EM2411, EM242, EM2421 and EM265 (manufactured by Changxing Materials); EBECRYL-160, EBECRYL-853, EBECRYL-2047, EBECRYL-40 and EBECRYL-140 (manufactured by UCB Co., Ltd.); CD501, SR351, SR368 , SR415, SR444, SR454, SR454HP, SR492, SR499, SR9008, SR9035, CD9051, SR350, SR9009, SR9011, SR295, SR9020, SR9021, SR355, SR399, SR494, SR9041, Ricacryl3500 and Ricacryl3801 (manufactured by SARTOM) 50; and MIRAMER M600 (manufactured by Miwon Corporation).

The acrylate monomer that can be used in the present invention contains at least 1 double bond, preferably contains at least 2 double bonds, more preferably contains 3 to 15 double bonds, and its molecular weight is not particularly limited. In some embodiments, acrylate The molecular weight of the monomer is 400 to 5000, such as but not limited to: 400, 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, or 5000, preferably 500 to 3000. Modified Alkyd Resin

The composition (b) modified alkyd resin used in the present invention is to allow the coating formulation to effectively adhere to the material substrate to be modified, improve the adhesion between the coating formulation and the material surface of the composite material, and modify the surface of the material. The spatial defects on the surface can achieve the effect of modifying the appearance of materials with height differences or fine seams. Therefore, the process of coating the foundation layer and/or primer layer can be omitted, which greatly simplifies the modification process of the material surface, and after curing The coating has good weather resistance and can avoid surface defects such as line marks caused by long-term use.

The above-mentioned modified alkyd resin refers to the resin obtained by modifying the alkyd resin by selecting appropriate monomers or resins according to the required physical properties, such as but not limited to: acrylic acid (ester) modified alkyd resin, styrene modified alcohol Acid resins, epoxy-modified alkyd resins, silicone-modified alkyd resins, phenolic-modified alkyd resins, rosin-modified alkyd resins, or mixtures thereof. In order to increase the hardness and heat resistance of the cured coating film, it is better to use a monomer or resin with a high glass transition temperature (Tg) to modify the alkyd resin. The monomer or resin with a high glass transition temperature (Tg) such as But not limited to: acrylic acid, methacrylic acid, acrylonitrile, methyl methacrylate, isobornyl acrylate, isobornyl methacrylate, cyclohexyl methacrylate, styrene, epoxy or mixtures thereof. According to one embodiment of the present invention, examples of modified alkyd resins suitable for the present invention include methyl methacrylate modified alkyd resins, styrene modified alkyd resins, epoxy modified alkyd resins or mixture.

In some embodiments, alkyd resins can be polymerized from vegetable oils or vegetable oleic acids (such as fatty acids), polyacids and polyols, such as but not limited to soybean oil, castor oil, dehydrated castor oil, coconut oil, Palm oil, linseed oil, tung oil, safflower oil or mixtures thereof. The above-mentioned vegetable oil or vegetable oleic acid may be used one, two or more as required. According to one embodiment of the present invention, the vegetable oil or vegetable oleic acid used is soybean oil, dehydrated castor oil or a mixture thereof. Alkyd resins can be divided into short oily alkyd resins, medium oily alkyd resins and long oily alkyd resins according to the content of vegetable oil or vegetable oleic acid used. Short oil, medium oil or long oil alkyd resins can be used in the present invention. According to one embodiment of the present invention, the alkyd resin used is a long oil alkyd resin.

The types of the above polyacids and polyols are not particularly limited, and may be any polyacids and polyols commonly used in alkyd resins. Examples of polybasic acids include, but are not limited to: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, Diacid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid Aliphatic saturated dibasic acids such as maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, glutaconic acid and other aliphatic unsaturated dibasic acids or their anhydrides; hexahydrophthalic acid Alicyclic saturated dibasic acids such as dicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; Alicyclic unsaturated dibasic acids such as tetrahydrophthalic acid; Phthalic acid and phthalic anhydride , isophthalic acid, terephthalic acid and other aromatic dibasic acids or their anhydrides; 1,2,5-hexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid and other aliphatic saturated Tribasic acid; aromatic tribasic acid such as trimellitic acid, trimellitic anhydride, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, or an anhydride thereof. Preferred polybasic acids are malonic acid, adipic acid, sebacic acid, maleic acid, maleic anhydride, glutaconic acid, 1,4-cyclohexanedicarboxylic acid, phthalic acid, phthalic acid anhydride, isophthalic acid, or terephthalic acid. Examples of polyols include, but are not limited to: methylolpropane, pentaerythritol, dipentaerythritol, trimethylolethane, neopentyl glycol, ethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexyldimethanol, diethylene glycol, triethylene glycol, polyethylene glycol, polytetrahydrofuran, polycaprolactone diol, polycaprolactone triol, triol Methylol Monoallyl Ether, Trimethylol Diallyl Ether, Pentaerythritol Triallyl Ether, Pentaerythritol Diallyl Ether, Pentaerythritol Monoallyl Ether, 2-Ethyl-2-(Hydroxymethyl)-1, 3-propanediol, 2-methyl-1,3-propanediol, 2,2,4-trimethylpentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2' - bis(4-hydroxycyclohexyl)propane (hydrogenated bisphenol A), propylene glycol, dipropylene glycol, polypropylene glycol, glycerol and sorbitol, preferably ethylene glycol, pentaerythritol, trimethylolethane, trihydroxy Methylpropane, Glycerin, 1,6-Hexanediol, Diethylene Glycol, Polycaprolactone Glycol and Sorbitol. One, two or more polybasic acids or one, two or more polyhydric alcohols may be used as needed.

Commercially available modified alkyd resins that can be used in the present invention are, for example but not limited to: 6390F (Eternal Materials), ETERKYD 242-XM-80 (Eternal Materials), ETERKYD NP1023-R-50 (Eternal Materials).

In some embodiments, the range of the solid content of the modified alkyd resin is not particularly limited, and the viscosity of the modified alkyd resin can be adjusted to an appropriate range with the first solvent as needed. The above-mentioned first solvent can be any suitable solvent known to those skilled in the art of the present invention, such as an aromatic hydrocarbon solvent. The aforementioned aromatic hydrocarbon solvents are, for example but not limited to, benzene, toluene, xylene or mixtures thereof. According to some embodiments of the present invention, the solid content of the modified alkyd resin ranges from 40 wt % to 60 wt %, for example: 40 wt %, 45 wt %, 50 wt %, 55 wt % or 60 wt %. The viscosity range of modified alkyd resin is 500 to 3000cps, such as but not limited to: 500, 600, 800, 1000, 1200, 1400, 1500, 1600, 1800, 2000, 2200, 2400, 2500, 2600, 2800, or 3000cps . When the viscosity of the modified alkyd resin is too low (for example, lower than 500 cps), it is not conducive to the adhesion between the paint formulation and the surface of the material; when the viscosity of the modified alkyd resin is too high (for example, higher than 3000cps ), it is not conducive to the operability of the paint formulation.

The modified alkyd resin of the present invention has good compatibility with other resins, oligomers and/or monomers, and can be directly blended (blending) in paint formulations without mixing with other resins, oligomers and/or monomers. Or monomer reaction, so it can also be used as a buffer medium to release the stress caused by rapid curing during the photocuring process. In some embodiments, the suitable weight average molecular weight of the modified alkyd resin is, for example but not limited to: 400,000 to 650,000, preferably 500,000 to 600,000. Generally speaking, the modified alkyd resin with higher molecular weight can exhibit better stress relief effect, so the adhesion between the coating formulation and the material surface of the composite material is good, and it can prevent cracks in the coating film from forming lines. Therefore, when the molecular weight of the modified alkyd resin is too low (for example, less than 400,000), it is not conducive to the adhesion between the coating formulation and the surface of the material; when the molecular weight of the modified alkyd resin is too high (such as When it is higher than 650,000), it is not conducive to the operability of the coating formulation due to poor compatibility with the monomer and the flatness of the coating after curing is not good.

According to some embodiments of the present invention, based on 100 parts by weight of the composition (a), the amount of the modified alkyd resin of the composition (b) is 50 to 150 parts by weight, for example: 50, 55, 60, 65, 70, 75 , 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, or 150 parts by weight, more preferably 75 to 125 parts by weight. When the amount of the modified alkyd resin is too low (for example, less than 50 parts by weight), it is not conducive to the adhesion between the coating formulation and the surface of the material; when the amount of the modified alkyd resin is too high (for example, When it is higher than 150 parts by weight), the coating formulation is not easy to cure. Photoinitiator

The composition (c) photoinitiator used in the present invention is one that generates free radicals after being irradiated with light, and initiates a polymerization reaction through the transmission of free radicals. The type of photoinitiator is not particularly limited, for example but not limited to: benzophenone-amine conjugated system; benzoin ethers; benzoyl and its ketals; or acetophenone derivatives. In addition, two or more photoinitiators may be used as needed.

The content of the photoinitiator of the composition (c) in the formulation is not particularly limited, and can be adjusted according to the type and amount of the monomer of the composition (a) contained in the formulation as needed. According to some embodiments of the present invention, based on 100 parts by weight of the monomer of composition (a), the content of the photoinitiator of composition (c) is 0.5 to 30 parts by weight, for example: 0.5, 1, 2, 4, 5, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, or 30 parts by weight, preferably 5 to 25 parts by weight.

Examples of commercially available photoinitiators that may be used in the formulations of the invention include: CHIVACURE 115, CHIVACURE ITX (isopropylthioxanthone), CHIVACURE EPD (ethyl p-(dimethylamino)benzoate), CHIVACURE OMB (methyl o-benzoylbenzoate), CHIVACURE EMK (N,N,N',N'-tetraethyl-4,4'-diaminobenzophenone), CHIVACURE BDK (2, 2'-Dimethyl-1,2-diphenylethan-1-one), CHIVACURE BMS (4-benzoyl-4'-methyldiphenylsulfide), CHIVACURE 184 (1-hydroxy cyclohexyl phenyl ketone), CHIVACURE 173 (2-hydroxy-2-methyl-1-phenyl-propan-1-one), CHIVACURE TPO (2,4,6-trimethylbenzoyldiphenyl Phosphine oxide) and CHIVACURE 200 (methyl phenylglycolate) (manufactured by Double Bond Chemicals (DBC) Co., Ltd.); AgiSyn™-1812 (1-hydroxycyclohexyl phenyl ketone), AgiSyn™-1810 (2-hydroxy -2-methyl-1-phenyl-propan-1-one), AgiSyn™-1801 and AgiSyn™-003 (manufactured by Xinlimei Technology Co., Ltd.); IRGACURE 369 (2-benzyl-2-N,N -Dimethylamino-1-(4-morpholinophenyl-1-butanone) and IRGACURE 2959 (4-(2-hydroxyethoxy)-phenyl-(2-hydroxy-2-methyl Propyl) ketone) (manufactured by BASF Corporation). Filler particles

The known PU type caulking glue is more flexible, so its coating tends to produce line marks at the joints of different materials after long-term use. The inventors of the present case found that the addition of filler particles in composition (d) can not only improve the hardness, sandability and finger scratch resistance of the obtained coating, but also improve or even eliminate the occurrence of line marks on the coating surface. The type of filler particles used in the present invention is not particularly limited, and low-cost and high-quality filler particles can be used, such as but not limited to: calcium carbonate, barium sulfate, aluminum hydroxide, quartz powder, talc powder, or silicon particles. In addition, two or more filler particles may be used as needed.

According to the present invention, there is no special limitation on the amount of the filler particles in component (d), and it can be adjusted according to the desired hardness, grinding speed, and finger scratch resistance. According to some embodiments of the present invention, based on 100 parts by weight of monomers of composition (a), the content of filler particles of composition (d) is 10 to 60 parts by weight, for example: 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, 32, 34, 35, 36, 37, 38, 39, 40, 42, 44, 45, 46, 48, 50, 52, 54, 55, 56, 58, or 60 parts by weight, preferably 35 to 60 parts by weight.

According to the present invention, the average particle size of the filler particles in component (d) is not particularly limited, and can be adjusted according to the required coating film thickness. According to some embodiments of the present invention, the suitable average particle size of the filler particles is 25 μm or less, and the average particle size is measured by a fineness meter (model: ZEHNTNER ZGR2020).

In some embodiments, the viscosity of the coating formulation of the present invention is, for example, a viscosity of 1 to 50 seconds as measured by NK-II Iwata cup at 25°C.

second solvent

The paint formulation of the present invention may optionally add one or more second solvents as component (e), so as to adjust the viscosity of the paint formulation within a suitable operating range. The second solvent may be added when the components are prepared, or may be added before the final coating. The content of the second solvent is not limited, and can be adjusted according to actual conditions and needs. The second solvent suitable for the present invention is not particularly limited, and can be any organic solvent commonly used in this field, such as but not limited to: Alkanes, aromatic hydrocarbons, ketones, esters, alcohols, ether alcohols, or their mixtures.

Suitable alkane solvents, such as but not limited to: n-hexane, n-heptane, isoheptane, or their mixtures. Suitable aromatic hydrocarbon solvents, such as but not limited to: benzene, toluene, xylene, or their mixtures. Suitable ketone solvents, such as but not limited to: methyl ethyl ketone (MEK), acetone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, or the like the mixture. Suitable ester solvents, such as but not limited to: isobutyl acetate (IBAC), ethyl acetate (EAC), butyl acetate (BAC), ethyl formate, methyl acetate, ethoxyethyl acetate, ethyl acetate Oxypropyl, ethyl isobutyrate, monomethyl ether propylene glycol acetate, amyl acetate, or a mixture thereof. Suitable alcohol solvents, such as but not limited to: ethanol, isopropanol, n-butanol, isoamyl alcohol, or a mixture thereof. Suitable ether alcohol solvents, such as but not limited to: ethylene glycol monobutyl ether (BCS), ethylene glycol monoethyl ether acetate (CAC), ethylene glycol monoethyl ether (ECS), propylene glycol monomethyl ether, propylene glycol mono Methyl ether acetate (PMA), propylene glycol monomethyl ether propionate (PMP), or a mixture thereof.

In some embodiments, the amount of the second solvent is such that the solid content of the formulation is 30 to 70 wt%, such as but not limited to: 30, 35, 40, 45, 50, 55, 60, 65, or 70 wt% .

In some embodiments, the formulation is optionally adjusted with a second solvent to obtain a desired viscosity, for example, a viscosity of 1 to 50 seconds as measured by an NK-II Iwata cup at 25°C, such as but not limited to: 1, A viscosity of 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 seconds to allow the formulation to have a viscosity that allows it to be at least pumpable, and even at least sprayable.

In some embodiments, when the second solvent exists, based on 100 parts by weight of the monomer of composition (a), the content of the second solvent is 50 to 300 parts by weight, for example: 50, 60, 80, 100, 120, 140, 150, 160, 180, 200, 220, 240, 250, 260, 280 or 300 parts by weight, preferably 150 to 250 parts by weight. clay

The paint formulation of the present invention may optionally add clay as component (f), so as to improve the sagging phenomenon that occurs when the viscosity of the paint formulation is too low. The amount of clay suitable for use in the present invention can be adjusted as desired, for example, according to the drape properties of the desired formulation after coating (eg, no edge build-up, no plugging). According to some embodiments of the present invention, when clay exists, based on 100 parts by weight of the monomer of composition (a), the content of clay is 0.1 to 10 parts by weight, for example: 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 parts by weight, preferably 2.5 to 7.5 parts by weight. If the amount of the clay is too low (<0.1 parts by weight), the desired sag resistance cannot be obtained; when the amount of the clay is too high (>10 parts by weight), the leveling property of the formulation is not good.

The term "sagging" used in this article refers to the degree of adhesion of the formulation on the vertical surface of the coating. High sagging means that the formulation is easy to accumulate on the vertical surface after coating and cause edge formation. Low Vertical flow means that the formulation can evenly adhere to the vertical surface after coating without edge accumulation. Generally speaking, if there are small holes or gaps on the surface of the material to be coated (usually the holes or gaps that are intentionally cut through and want to be preserved), after coating the formulation with high drape, due to the edge accumulation effect, The small gouges or gaps will be filled; on the contrary, since the low-sagging formulations are not easy to form edge after being coated on the vertical surface, the small gouges are not easy to be filled by the low-sagging formulations.

The type of clay suitable for the present invention is not particularly limited, such as but not limited to being selected from the group consisting of: montmorillonite, kaolinite, saponite, hectorite ), Attapulgite, illite, mica, and chlorite. In addition, two or more clays may be used as needed.

In some forms, the average particle size of the clay can be adjusted according to the required coating thickness. Generally speaking, thicker coatings can use clay with a larger average particle size, and thinner coatings can use Clay with a small average particle size. According to some embodiments of the present invention, the suitable average particle size of the filler particles is 5 μm or less, such as but not limited to 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5 μm, The average particle size of clay is measured by fineness meter (model: ZEHNTNER ZGR2020).

In some aspects, the paint formulation of the present invention further includes a second solvent and clay. Although the use of the second solvent can reduce the viscosity of the paint formulation to facilitate coating, the reduction in viscosity is likely to cause the paint formulation to be at the edge of the material. However, the inventors unexpectedly found that, in these aspects, the drooping phenomenon can still be improved by additionally adding clay. In some embodiments, in these aspects, when the clay is present in an amount of 0.02 to 2% by weight based on the total weight of the paint formulation, the paint formulation has excellent sag resistance and inhibits edge build-up, It can ensure that the pores or crevices that are intentionally pierced and reserved on the material will not be filled by the paint formulation. When the amount of the clay is too low (for example, less than 0.02% by weight), sagging phenomenon is likely to occur, and when the amount of the clay is too high (for example, more than 2% by weight), the leveling property of the paint formulation is not good . additive

The formulations of the present invention may optionally include additives known to those skilled in the art, such as but not limited to: leveling agents, wetting agents, colorants, stabilizers, thickeners, adhesion promoters, antioxidants, hindered Amine light stabilizers, rheology modifiers, dispersants, antistatic agents or other performance or property modifiers. The types of the above-mentioned additives are known to those with ordinary knowledge in the technical field of the present invention, and their dosages can be easily determined according to different needs by those with ordinary knowledge in the technical field of the present invention. According to some embodiments of the present invention, based on 100 parts by weight of the monomer of composition (a), the content of the additive is 0 to 10 parts by weight, for example: 0, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5 , 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 parts by weight.

In some embodiments, the photocurable coating formulation of the present invention may be added with a leveling agent and/or a wetting agent as needed to further improve the leveling and wettability of the formulation on the material and improve the wetting effect And reduce the surface tension, which helps the adhesion between the paint formulation and the material, thereby simplifying the subsequent polishing process of the cured coating. Suitable wetting agents or leveling agents such as but not limited to: Efka, the Netherlands EFKA3777, EFKA3886, EFKA3883 and EFKA3600 of the company; BYK366, BYK300, BYK333, BYK307, BYK340, BYK341, BYK344, BYK3500, BYK3510, BYK3530 of BYK Chemical Company (BYK) and BYK35GOGO of Tego (Germany); 4000, TEGO Wet270, TEGO 410 and TEGO 450; CARBOWET13-40 SURFACTANT of Air Products; and Modaflow resin, Modaflow 2100, Modaflow 9200, Modaflow AQ-3000, Modaflow AQ-3025, Multiflow resin, XL 480, XL 490, VXL 6230, VXL 6236, XW 390, XW 395, VXW 6508, VXW 4971, VXW 6214 and VXW 6502.

The term "colorant" as used herein means any substance that imparts color and/or other opacity and/or other visual effects to the formulation.

In some embodiments, the photocurable coating formulation of the present invention may optionally add a colorant to help the naked eye judge the flatness of the coating after grinding. Colorants may be added to the formulation in any suitable form, such as discrete particles, dispersions, solutions and/or flakes. A single colorant or a mixture of two or more colorants may be used in the coatings of the present invention.

Colorants suitable for use in the present invention include: pigments, dyes or tints such as, but not limited to, those used in the paint industry and/or listed on the Dry Color Manufacturers Association, DCMA) listed colorants. The above-mentioned colorants can be organic or inorganic and can be incorporated into the paint by grinding or simple mixing.

According to an embodiment of the present invention, the colorant used in the present invention is a pigment. The above-mentioned pigments may be organic pigments or inorganic pigments, and examples thereof include: oxazole dioxazine crude pigments, azo, monoazo, disazo, naphthol AS, salt type (lake), benzimidazolone, Condensate, metal complex, isoindolinone, isoindoline and polycyclic phthalocyanine, quinacridone, perylene, perinone, diketopyrrolopyrrole, thioindigo, anthraquinone , indanthrene, anthracene, flavanthrene, pyranthrone, anthraquinone, dioxazine, triaryl carbonium, quinolphthalone pigment, diketopyrrolopyrrole ("DPPBO red") ), titanium dioxide, carbon black, carbon fiber, graphite, other conductive pigments and/or fillers, or mixtures thereof. Coating method

The photocurable coating formulation of the present invention can be applied to the surface of the material by any means known to those skilled in the art to which the present invention pertains. For example, administered via a method comprising the steps of: (1) Select the above-mentioned monomer containing at least one double bond, modified alkyd resin, photoinitiator, filler particles, and optional additives, clay, and/or second solvent, stir and mix and Adjust to an appropriate viscosity to form a one-component formulation; (2) Apply the resulting photocurable coating formulation on the surface of the material in an appropriate manner to form a coating; (3) Drying, if necessary, to remove the solvent (including the second solvent and optionally the first solvent used to modify the alkyd resin); and (4) Irradiate with energy rays to cure the coating.

Materials suitable for coating the photocurable coating formulation of the present invention are not particularly limited, for example, ceramic tiles, wood, leather, stone, glass, metal, alloy, paper, plastic, fiber, cotton fabric, etc., preferably glass , metal, plastic or composite material substrates, especially materials used in 3C electronic products, home appliances and cosmetics. The aforementioned metal substrates are, for example but not limited to: stainless steel, zinc alloy, aluminum, aluminum alloy, magnesium alloy, chrome, or combinations thereof. The above-mentioned plastic substrates are for example but not limited to: acrylonitrile-butadiene-styrene copolymer (ABS), polycarbonate (PC), polypropylene (PP), polymethyl methacrylate (PMMA), polystyrene ( PS), PC/ABS, polyphenylene sulfide (PPS), polyamide (PA) or a combination thereof. It is preferably a composite material substrate made of two or more different materials, such as but not limited to: a composite material plate composed of carbon fiber and 50% PC and 50% glass fiber material; carbon fiber and 55% Composite material board made of glass fiber PA; composite material board made of aluminum board and PPS containing 40% glass fiber; or composite material board made of plastic and aluminum-magnesium alloy.

Coating methods used in the above step (2), such as but not limited to: bar coating, slot die coating, gravure coating, inclined plate coating Slide coating, curtain coating, or spray coating, preferably spray coating (spray coating).

The drying method for removing the solvent in the above step (3) is not particularly limited, and any known appropriate method can be used, such as but not limited to: irradiating infrared rays or hot air to bake the coating. In some embodiments, the baking temperature can be from 50 to 120°C, such as but not limited to: 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, Or 120°C; the baking time can be 1 to 20 minutes, such as but not limited to: 1, 2, 4, 5, 6, 8, 10, 12, 14, 15, 16, 18, or 20 minutes.

The curing used in the above step (4) is carried out by irradiating energy rays to generate photopolymerization. The energy rays refer to light sources with a certain range of wavelengths, such as ultraviolet light, infrared light, visible light or high-energy rays (electron beams), etc. Ultraviolet light (wavelength 200 to 400 nm) is preferred. The irradiation energy density can be from 800 to 2000 mJ/cm ² , such as but not limited to: 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550 , 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950 or 2000 mJ/cm ² , preferably 900 to 1600 mJ/cm ² . By using the aforementioned photopolymerization reaction for curing, the process time can be shortened to less than 30 seconds.

In some embodiments, before the formulation of the present invention is applied to the surface of the material, a sieve can be used to remove particles remaining in the formulation. In some embodiments, the suitable mesh size of the mesh is 300 to 600 mesh, such as 300 mesh, 400 mesh, 500 mesh or 600 mesh, preferably 500 mesh.

The present invention further provides a caulk comprising the photocurable coating formulation as described herein.

It is known that the PU type caulking adhesive system is baked and cured at high temperature, but if it is directly baked at high temperature, it will easily cause volcanic holes that are not dry on the surface, so it must be left at room temperature for a period of time to let the solvent evaporate first, and then carry out High temperature baking and curing, so the process takes a long time. The caulking adhesive of the present invention is light-cured, and can be directly baked to remove the solvent, which can shorten the process time, increase the yield, and achieve the purpose of energy saving.

In addition, the known application method of PU-type gap filler includes spraying a primer on the surface of the material to improve the adhesion between the coating of the gap filler and the surface of the material. The adhesion between the gap filler of the present invention and the surface of the material is good, and it can be directly coated on the surface of the material. Therefore, in some preferred forms of the present invention, the surface of the material to be coated does not need to undergo any process. Pre-treatment, such as surface treatment agent, coating primer layer, coating foundation layer, and/or sanding those layers, etc. The use of the light-curable coating formulation of the present invention can greatly simplify the known process of using PU-type gap fillers to modify the spatial defects on the surface of materials. In addition, according to some specific implementation aspects of the present invention, when the gap filler of the present invention is coated on the surface of the material, it exhibits good sag resistance, which can ensure that the pores or crevices deliberately drilled on the material will not be damaged. The formulation fills without edge buildup.

According to some embodiments of the present invention, if the slits or grooves on the surface of the material have too much space drop, an additional soil filling layer may be applied as needed, and the light-curing layer of the present invention may be coated again on the filling soil layer. Form the coating formulation until a desired appearance is obtained. According to some preferred aspects of the present invention, since the formulation of the present invention has a sufficiently high adhesion, the soil filling layer can directly contact with the formulation of the present invention, and there is no need to apply a primer between them to increase the adhesion. Adhesion. Compared with the prior art, the use of the photocurable coating formulation of the present invention can greatly simplify the process.

The thickness of the coated film is not particularly limited, and can be adjusted according to the degree of finishing of the material or the thickness of the grinding to be removed by grinding. In some embodiments, the film thickness of the cured formulation is 10 to 200 μm, for example But not limited to: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, or 200 μm, preferably 30 to 100 μm. example

The following examples are used to further illustrate the present invention, but are not intended to limit the scope of the present invention. Modifications and changes that can be easily achieved by any person familiar with this technology are included in the disclosure content of this case specification and the scope of the appended patent application.

According to the ingredients and proportions listed in Table 1, prepare a single-component photocurable formulation: Table 1 sample Monomer* (g) Modified Alkyd Resin (g) Photoinitiator Talc powder (g) GARMITE-1958 clay (g) TEGO Wet270 Additive (g) Colorant Second solvent (g) NK-II Iwata Cup Viscosity@25°C (sec) 1 20 6390F (Eternal Material; M _w about 550,000) 20 CHIVACURE TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) 1.67g and CHIVACURE 184 (1-hydroxycyclohexyl phenyl ketone) (Double Bond Chemical) 3.33g 10 1 0.5 Titanium dioxide 0.9 g and carbon black 0.1 g Ethyl acetate (EAC) 18g, butyl acetate (BAC) 9g, toluene 9g, and isopropanol (IPA) 9g 35 2 17 twenty three 10 1 0.5 - 40 3 26 16 8 1 0.5 - 30 4 20 ETERKYD 242-XM-80 (Eternal Material; M _w about 350,000) 20 10 1 0.5 - 30 5 20 Methyl methacrylate modified alkyd resin ( _Mw about 655,000) 20 10 1 0.5 - 35 6 50 - - - - - - Ethyl acetate (EAC) 18g, butyl acetate (BAC) 9g, toluene 9g, and isopropanol (IPA) 9g 8 7 25 A6390F (Eternal Material; M _w about 550,000) 25 - - - - 12 8 20 20 10 - - - 35 9 20 20 10 1 - - 35 10 20 20 10 1 0.5 - 35 11 25 50 - - - - 80 12 20 20 1 1 0.5 Titanium dioxide 0.9 g and carbon black 0.1 g twenty two 13 20 20 14 1 0.5 96 14 20 20 6 0.01 0.5 45 15 20 20 6 3 0.5 56 *Monomer: EM221 (1,6-Hexanediol Diacrylate (HDDA)): EM235 (Pentaerythritol Triacrylate (PET3A)): EM39 (2-Hydroxyethyl Methacrylate Phosphate (HEMAP)) ( Changxing material) = 2:1:1 (weight ratio)

Grind the surface of aluminum-magnesium alloy and polyphenylene sulfide (PPS) containing 40% glass fiber with No. 1000 sandpaper, filter the formulations according to samples 1 to 13 in Table 1 with a 500 mesh screen in sequence, and spray them with an air spray gun The formulations were spray-coated on the substrates to form a coating with a thickness of about 50 μm, and the substrates were baked in an infrared oven at 60°C for 10 minutes to remove the solvent, and then heated in a 1000 mJ/cm ² The coating was exposed to a pressure mercury lamp for 60 seconds to produce a cured coating.

The coatings prepared from the formulations of samples 1 to 13 were tested for the following properties: Curability : After irradiating a 1000 mJ/ ^cm2 medium-pressure mercury lamp for 60 seconds, the curing degree of the coatings of each sample: adhesion reached 5B (After being glued tightly with 3M-300 tape, the surface film layer will not peel off at 90°) and the pencil hardness ≧ H (using a pencil for Mitsubishi standard hardness test, testing the hardness of the coating under a load of 1 kg) is considered good. Adhesion between the coating and the substrate : According to the test method of ASTM D3359-93, scrape the coating surface of the cured composite substrate with a 100-grid scraper, stick the tape, tear it off at 90°, and calculate the peeling grid Number, among which 5B adhesion indicates the best adhesion, and 0B adhesion indicates the worst adhesion. ● Leveling property : observe the surface morphology of the coating with naked eyes. Leveling Judgment Standard grade 1 2 3 4 5 Morphology of the coating after curing Wrinkles (Severe) Bumps Wrinkles (many) Wrinkles (less) wrinkles (slight) Wrinkles (none) like a mirror ● Sag resistance: observe the coating morphology at the edge with naked eyes. Judgment standard of sag resistance grade 1 2 3 4 5 Coating phenomenon during coating (before curing) Sagging (serious) Severe edge accumulation Vertical flow (multiple) vertical flow (less) droop (slight) vertical flow (none) flat surface ● Hardness: Test the hardness of the coating with a Mitsubishi standard hardness test pencil under a load of 1 kg. ● Scratch resistance: Scratch the coating with fingernails, no scratches indicate good finger-scratch resistance; scratches indicate poor finger-scratch resistance. ● Grindability: the number of times it can be flattened after grinding with No. 1000 sandpaper (the whole substrate is sanded back and forth once), grade 5 means that a flat surface can be obtained after only one round of sanding (easy to sand), and grade 1 means that it needs five rounds of sanding or more times to obtain a flat surface (difficult to sand). Criteria for judging abrasiveness grade 1 2 3 4 5 Polishing times ≧5 4 3 2 1 Visual visibility of polished flatness: "Easy" means that under the reflection of light, the surface of the polished material can be recognized with the naked eye; "difficult" means that under the reflection of light, the surface of the polished material cannot be recognized with the naked eye Is it flat. ● Recoatability: The adhesion after recoating meets 5B adhesion, which is considered as good recoatability. ● Weather resistance test: the test conditions are (1) high humidity resistance, temperature 45°C, humidity 95%, standing for 48 hours; (2) high temperature resistance, temperature 60°C, humidity 30%, standing for 48 hours; And (3) high and low temperature cycle, temperature -20°C to 60°C, humidity 30%, stand still for 50 hours. After the weather resistance test, if there is no visible line mark on the coating surface per 100cm ² area, it is "passed" (see Figure 2); if more than one line mark visible to the naked eye appears, it is "failed". ● Storage stability: Stored at 60°C for 30 days, if no gelling or precipitation occurs, it means good storage stability. Table 2 sample curability Adhesion Leveling Anti-sagging hardness Finger scratch resistance Grinding Polishing flatness judged by naked eyes recoatability Weather resistance test Stability of the formulation before curing 1 good 5B 5 5 2H good 5 easy good pass good 2 good 5B 5 5 2H good 5 easy good pass good 3 good 5B 5 5 2H good 5 easy good pass good 4 good 2B 5 5 2H good 5 easy good Did not pass good 5 good 5B 2 3 2H good 5 easy bad pass Difference 6 good 0B - - - - - - - - good 7 good 5B 3 2 HB bad 0 difficult good Did not pass good 8 good 5B 4 3 2H good 5 difficult good pass good 9 good 5B 4 5 2H good 5 difficult good pass good 10 good 5B 5 5 2H good 5 difficult good pass good 11 Difference 0B - - - - - - - - good 12 good 5B 5 5 h good 3 easy good Did not pass good 13 good 3B 5 5 3H good 5 easy good Did not pass good 14 good 5B 5 1 2H good 5 easy good pass good 15 good 5B 1 5 2H good 5 easy good pass good

As shown in the results in Table 2, substrates treated with photocurable formulations of the present invention (such as samples 1, 2, 3, and 10) can impart coatings and substrates without other pretreatment methods The required adhesion, and the resulting coating has a smooth appearance, no defects, good weather resistance, and no traces, which can meet the needs of the industry.

In addition, comparing the results of samples 1, 2 and 3 with sample 10, it can be seen that the formulation of the present invention may additionally contain a colorant, and the added colorant will not affect the photocurability of the formulation, and the addition of the colorant can When grinding the coating, it is convenient to directly judge the flatness of the coating with the naked eye.

Comparing the results of sample 9 and sample 10, it can be seen that the addition of leveling agent can further improve the leveling property of the formulation.

From the results of samples 6 and 7, it can be seen that when no modified alkyd resin is added (sample 6), the adhesion between the coating and the coated surface is not good; when no filler particles (talcum powder) are added (sample 6 and 7), the coating has poor sandability and the hardness and finger scratch resistance do not meet the standards.

From the results of samples 8 and 9, adding clay (sample 9) can further improve the anti-sagging effect.

From the results of Sample 4, it can be seen that the formulation cannot impart satisfactory adhesion between the coating and the substrate if the modified alkyd resin with too low molecular weight is used.

From the results of sample 5, it can be seen that if the modified alkyd resin with too high molecular weight is used, the compatibility of the components of the formulation is not good, resulting in uneven coating after curing.

From the results of sample 11, it can be seen that with too high a content of resin, the viscosity of the formulation is too high and cannot be effectively cured.

From the results of samples 12 and 13, it can be seen that if the amount of filler is too low, the sandability and hardness of the coating will be poor; if the amount of filler is too high, the viscosity of the formulation will be too high and the coating adhesion will be poor.

From the results of samples 14 and 15, it can be seen that if the amount of clay is too low, the desired sagging resistance cannot be obtained, and if the amount of clay is too high, the leveling property of the formulation will be poor.

Figure 1: After the weather resistance test of the PU-type gap filler coating of the prior art, line mark defects can be observed at the joints of different materials in the composite material. Figure 2: After the weather resistance test of the coating of the photocurable coating formulation of the present invention, there is no trace defect at the joint of different materials in the composite material.

Claims (10)

A gap filler comprising a photocurable coating formulation comprising: (a) a monomer containing at least one double bond; (b) a modified alkyd resin comprising acrylic acid (ester) Modified alkyd resins, styrene-modified alkyd resins, epoxy-modified alkyd resins, silicone-modified alkyd resins, phenolic-modified alkyd resins or mixtures thereof; (c) photoinitiators; (d ) filler particles; and (f) clay, wherein based on 100 parts by weight of the total weight of component (a), the content of the modified alkyd resin is 50 to 150 parts by weight, and the content of the photoinitiator is 0.5 to 100 parts by weight. 30 parts by weight, the content of the filler particles is 10 to 60 parts by weight, the content of the clay is 0.1 to 10 parts by weight, wherein the weight average molecular weight of the modified alkyd resin is 400,000 to 650,000. The gap filler according to claim 1, wherein the monomer containing at least one double bond is an acrylate monomer. The gap filler according to claim 1, wherein the weight average molecular weight of the modified alkyd resin is 500,000 to 600,000. Such as the gap filler of claim 1, wherein the total weight of component (a) is 100 parts by weight, the modified The content of the permanent alkyd resin is 75 to 125 parts by weight. The gap filler according to claim 1, wherein the content of the photoinitiator is 5 to 25 parts by weight based on 100 parts by weight of component (a). The gap filler according to claim 1, wherein the content of the filler particles is 35 to 60 parts by weight based on 100 parts by weight of component (a). Such as the joint filler of claim 1, wherein the clay is selected from the group consisting of the following: montmorillonite, kaolinite, saponite, hectorite, ertier Attapulgite, illite, mica, chlorite and combinations thereof. The gap filler as claimed in claim 1, which additionally contains additives. The gap filler according to claim 7, wherein the filler particles are selected from the group consisting of calcium carbonate, barium sulfate, aluminum hydroxide, quartz powder, talcum powder, silicon particles and combinations thereof. The gap filler according to claim 9, wherein the content of the clay is 0.1 to 7.5 parts by weight based on 100 parts by weight of component (a).

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