Uv-curable dip coating ink on a tape backing

Abstract

The application discloses a kind of for tape bottom layer on ultraviolet light solidification dip coating ink, the ultraviolet light solidification dip coating ink is composed of the following weight parts of component: photocuring oligomer: 30-50 parts, functional active monomer: 20-50 parts, photo initiator: 3-6 parts pigment: 5-35 parts, dispersing agent: 1-3 parts, surface auxiliary agent: 1-2 parts;The synthesis steps of the photocuring oligomer are: after epoxy E51 is mixed with octandioic acid, under the condition of nitrogen protection, temperature is controlled 115 DEG C, reaction 3-4h, when acid value is less than 10mgKOH / g, reduce reaction temperature to 85-95 DEG C, add polymerization inhibitor, slowly drop catalyst and glutaric acid-3-ethyl-3-oxetane monomethyl ester, drop adding time is controlled at 30-40min, and reaction 7-8h, when acid value is less than 10mgKOH / g, control reaction temperature to 65-75 DEG C, add isocyanatoethyl acrylate and reaction 5-6h, obtain photocuring oligomer with oxetane and acrylate structure simultaneously.The application has the characteristics of low viscosity, good leveling performance, has very good adhesion on steel tape, and solidification speed is relatively fast.

Description

Technical Field

[0001] This invention belongs to the field of ultraviolet curable coating preparation technology, and specifically relates to an ultraviolet curable dip-coating ink for the bottom of a measuring tape. Background Technology

[0002] Measuring tapes are commonly used tools in daily life. As basic consumables in industries such as processing, manufacturing, building materials, and decoration, they have a huge and continuous consumer demand.

[0003] Currently, the bottom layer ink used in printing coated measuring tapes is water-based ink. Due to environmental pressures in recent years, it has been replaced by solvent-based varnishes. Although water-based inks are more environmentally friendly than solvent-based varnishes and solve the problem of large VOC emissions from solvent-based varnishes, they still require high-temperature baking at temperatures above 200°C and still need to undergo exhaust gas treatment. They are energy-intensive, have complicated exhaust gas treatment processes, and lack economic advantages.

[0004] Ultraviolet (UV) curing is the most widely used type of radiation curing technology. UV-curable inks can instantly react and form a film under UV light irradiation. They feature rapid curing, low energy consumption, no exhaust gas treatment, and excellent economic value, offering significant advantages over water-based inks. However, there are currently no reports or patented technologies regarding the application of UV-curable inks on the underside of steel measuring tapes. The main challenge lies in the large volume shrinkage of UV-curable inks and the relatively low surface tension and smoothness of steel. Therefore, achieving proper adhesion between UV-curable inks and steel measuring tapes is extremely difficult.

[0005] Patents CN114891393A and CN114958089A are both UV inks used on measuring tapes, but they are mainly used on top of existing water-based baking paint inks and do not directly contact the steel. They are a type of UV inkjet printing ink technology used for printing scale lines, and are fundamentally different from the underlying inks that directly contact the steel. Summary of the Invention

[0006] To address the technical problems of high energy consumption and low economic value in the coating process of measuring tapes in existing technologies, this invention provides a UV-curable dip-coating ink for the bottom layer of measuring tapes. This UV-curable ink, used as the bottom layer of a steel measuring tape, directly contacts the steel, solving the problem of poor adhesion of UV-curable inks to steel. It can be applied to the measuring tape by dip coating, ultimately achieving a coating effect with excellent performance in all aspects.

[0007] A UV-curable dip-coating ink for the underside of a measuring tape, characterized in that the UV-curable dip-coating ink is composed of the following components in parts by weight:

[0008] Photocurable oligomer: 30-50 parts

[0009] Functional active monomers: 20-50 parts

[0010] Photoinitiator: 3-6 parts

[0011] Pigment: 5-35 parts

[0012] Dispersant: 1-3 parts

[0013] Surface additives: 1-2 parts;

[0014] The synthesis steps of the photocurable oligomer are as follows: epoxy E51 is mixed with octanoic acid and reacted at 115°C under nitrogen protection for 3-4 hours. When the acid value is <10mgKOH / g, the reaction temperature is reduced to 85-95°C, a polymerization inhibitor is added, and a catalyst and glutaric acid-3-ethyl-3-oxabutane monomethyl ester are slowly added dropwise over a time of 30-40 minutes. The reaction is continued for 7-8 hours. When the acid value is <10mgKOH / g, the reaction temperature is controlled to 65-75°C, ethyl isocyanate acrylate is added, and the reaction is continued for 5-6 hours to obtain a photocurable oligomer with both oxabutane and acrylate structures.

[0015] Preferably, the weight ratio of glutaric acid-3-ethyl-3-oxabutane monomethyl ester, epoxy resin E51, octanoic acid, isocyanate acrylate, polymerization inhibitor and catalyst is 45-48:74-76:17-19:20-40:1-3:1-5.

[0016] Preferably, the synthesis steps of glutaric acid-3-ethyl-3-oxabutane monomethyl ester are as follows: 3-ethyl-3-hydroxymethyl-oxabutane and glutaric anhydride are mixed and reacted at a temperature of 70-75°C for 5 hours under the conditions of a catalyst and a polymerization inhibitor. The product obtained after washing, filtration and drying is glutaric acid-3-ethyl-3-oxabutane monomethyl ester.

[0017] Preferably, the mass ratio of 3-ethyl-3-hydroxymethyl-oxecyclobutane, glutaric anhydride, catalyst and polymerization inhibitor is 23-25:22-23:0.5-1.5:0.2-2.

[0018] Preferably, the epoxy value of the epoxy resin is 0.5-0.54.

[0019] Preferably, the polymerization inhibitor is one or a mixture of two or more of p-hydroxyanisole, 2-tert-butylhydroquinone, and tert-butylcatechol; and the catalyst is one or a mixture of two or more of tetrabutylammonium bromide, dibutyltin dilaurate, organobismuth, triethylamine, and triphenylphosphine.

[0020] Preferably, the photocurable oligomer has a dual initiation mechanism, possessing both oxobutane and acrylate photosensitive structures. Both free radical and cationic mechanisms can initiate its curing, resulting in a functionality of 2-5 functionals and a number-average molecular weight of 1600-2300 g / mol.

[0021] Preferably, the functional active monomer is one or a mixture of two or more of the following: 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, bis((3,4-epoxycyclohexyl)methyl)adipate, dipentene dioxide, dicyclopentadiene diepoxide, tetrahydroepoxide, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, 3,3'-(oxydimethylene)bis(3-ethyl)oxetane, ethoxytrimethylolpropane triacrylate, 4-tert-butylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, cyclotrimethylolpropane methyl acetal acrylate, and 2-phenoxyethyl acrylate.

[0022] Preferably, the photoinitiator is one or a mixture of two or more of the following: 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate, bis(4-dodecylbenzene)iodohexafluoroantimonate, 4,4'-xylyliodonium hexafluorophosphate, and 2,4-diethylthioxanthrone.

[0023] Preferably, the pigment is one or a mixture of two or more of benzidine yellow, titanium dioxide, Hansa yellow, phthalocyanine green, and phthalocyanine blue.

[0024] Preferably, the dispersant is one or a mixture of two or more of Tego685, Lubrizol 24000, BYK168, and BYK104.

[0025] Preferably, the surface additive is one or a mixture of two or more of BYK333, Tego432, Tego500, Tego920, Tego900, BYK3500, and BYK358N.

[0026] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0027] The UV-curable dip-coating ink prepared by this invention can be creatively applied to measuring tapes, meeting the construction process requirements for dip coating of steel measuring tapes. With a dry film thickness of 7-10 μm, it exhibits good adhesion, coverage, and flexibility on steel. It also provides excellent performance in other aspects required by measuring tapes. Compared with traditional solvent-based and water-based inks, it features lower energy consumption, faster production speed, and higher economic value. Detailed Implementation

[0028] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the present invention.

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0030] The formulations used in this invention are all commercially available conventional products, as long as they are qualified industrial products and not limited to those from manufacturers.

[0031] In this invention, the following terms have specific meanings:

[0032]

[0033] Example 1: Preparation of 3-ethyl-3-oxabutane monomethyl glutarate

[0034] 3-Ethyl-3-oxabutane monomethyl glutarate was synthesized according to the formulations in Table 1 below.

[0035]

[0036] TR-TCM101 and glutaric anhydride were added to the reactor in a 1:1 molar ratio according to the above formula. Then, TBAB catalyst and MEHQ polymerization inhibitor were added. The temperature was controlled at 70-75℃ and the reaction was carried out for 5 hours. The infrared spectrum of the product was tested to confirm the disappearance of the characteristic peak of the anhydride. The product was washed twice with deionized water and the aqueous phase was separated. It was dried with anhydrous sodium sulfate and then filtered to obtain the product. The product mass obtained according to the above raw material ratio was 45.3g. The product mass was less than 46g, which was mainly due to the loss during the experiment. The mass was increased by 5 times and the product was tested again. The viscosity was 160mPa.s (25℃) and the molecular weight was about 230g / mol according to GPC analysis.

[0037] Example 2: Preparation of photocurable oligomers

[0038] The photocurable oligomers were synthesized according to the formulations in Table 2 below.

[0039]

[0040] Epoxy E51 and succinic acid were reacted at 115℃ for 3-4 hours under nitrogen protection. When the acid value was <10 mg KOH / g, the reaction temperature was lowered to 85-95℃, and the polymerization inhibitor MEHQ was added. TBAB and CH-1 or CH-2 were slowly added dropwise over 30-40 minutes, and the reaction continued for 7-8 hours. When the acid value was <10 mg KOH / g, the reaction temperature was controlled at 65-75℃, and Karenz AOI and organic bismuth were added, reacting for 5-6 hours. The reaction ended when NCO <1%, yielding the products. GPC analysis showed that the number average molecular weight of PD-1 was 1490 g / mol, PD-2 was 1509 g / mol, PD-3 was 1600 g / mol, and PD-4 was 1712 g / mol. Infrared spectroscopy was used to characterize the products, with the corresponding 810 cm⁻¹ values... -1 The varying absorption peaks indicate that the double bond content on PD-1, PD-2, PD-3, and PD-4 differs, while the characteristic COC absorption peak of oxetane is 980 cm⁻¹. -1 The results are basically consistent, indicating that the products contain both oxetane and double bond structures. The oxetane structures of different products are consistent, while the double bond content varies slightly.

[0041] Example 3: Preparation of Color Paste

[0042] The color paste is prepared according to the formula in Table 3 below.

[0043]

[0044] The above materials are added to the reactor in proportion, the temperature is controlled at 40-50℃, the dispersion speed is 500-800rpm, and then the mixture is ground with a sand mill to make its fineness <10um and viscosity 400-600mPa.s.

[0045] Example 4: Preparation of UV-curable dip-coated ink for the underside of a measuring tape

[0046] The UV-curable dip coating ink is prepared according to the formula in Table 4 below.

[0047]

[0048]

[0049] Example 5: Test Methods and Results

[0050] The measuring tape was dipped in ink and then cured under ultraviolet light. The UVA curing energy was 800 mJ / cm. 2 The tested film thickness was 7-10 μm.

[0051]

[0052] The data above shows that the self-synthesized photocurable oligomers achieve an excellent balance between adhesion and curing ability. Ultimately, by adjusting the self-synthesized photocurable oligomers, a photocurable ink that meets the coating requirements of measuring tapes was developed, exhibiting excellent adhesion and flexibility. The successfully developed photocurable dip-coating ink for the bottom layer of measuring tapes can replace traditional solvent-based or water-based inks currently on the market, thereby reducing energy consumption and improving production efficiency for measuring tape manufacturers.

Claims

1. A UV-curable dip-coating ink for the underside of a measuring tape, characterized in that, The UV-curable dip-coating ink is composed of the following components in parts by weight: Photocurable oligomer: 30-50 parts Functional active monomers: 20-50 parts Photoinitiator: 3-6 parts Pigment: 5-35 parts Dispersant: 1-3 parts Surface additives: 1-2 parts; The synthesis steps of the photocurable oligomer are as follows: epoxy resin E51 is mixed with octanoic acid and reacted at 115°C under nitrogen protection for 3-4 hours. When the acid value is <10mgKOH / g, the reaction temperature is reduced to 85-95°C, a polymerization inhibitor is added, and a catalyst and glutaric acid-3-ethyl-3-oxabutane monomethyl ester are slowly added dropwise over a time of 30-40 minutes. The reaction is continued for 7-8 hours. When the acid value is <10mgKOH / g, the reaction temperature is controlled to 65-75°C, ethyl isocyanate is added, and the reaction is continued for 5-6 hours to obtain a photocurable oligomer with both oxabutane and acrylate structures.

2. The UV-curable dip-coated ink on the bottom layer of the measuring tape according to claim 1, characterized in that, The weight ratio of glutaric acid-3-ethyl-3-oxabutane monomethyl ester, epoxy resin E51, octanoic acid, isocyanate acrylate, polymerization inhibitor and catalyst is 45-48:74-76:17-19:20-40:1-3:1-5.

3. The UV-curable dip-coating ink on the underside of a measuring tape according to claim 1 or 2, characterized in that, The synthesis steps of the glutaric acid-3-ethyl-3-oxabutane monomethyl ester are as follows: 3-ethyl-3-hydroxymethyl-oxabutane and glutaric anhydride are mixed and reacted at 70-75℃ for 5 hours under the conditions of catalyst and polymerization inhibitor. The product obtained after washing, filtration and drying is the glutaric acid-3-ethyl-3-oxabutane monomethyl ester.

4. The UV-curable dip-coated ink on the bottom layer of the measuring tape according to claim 3, characterized in that, The mass ratio of 3-ethyl-3-hydroxymethyl-oxecyclobutane, glutaric anhydride, catalyst, and polymerization inhibitor is 23-25:22-23:0.5-1.5:0.2-2.

5. The UV-curable dip-coated ink on the bottom layer of the measuring tape according to claim 4, characterized in that, The epoxy value of the epoxy resin E51 is 0.5-0.

54.

6. The UV-curable dip-coated ink on the bottom layer of the measuring tape according to claim 5, characterized in that, The polymerization inhibitor is one or a mixture of two or more of p-hydroxyanisole, 2-tert-butylhydroquinone, and tert-butylcatechol; the catalyst is one or a mixture of two or more of tetrabutylammonium bromide, dibutyltin dilaurate, organobismuth, triethylamine, and triphenylphosphine.

7. The UV-curable dip-coated ink on the bottom layer of the measuring tape according to claim 1, characterized in that, The functional active monomer is one or a mixture of two or more of the following: 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, bis((3,4-epoxycyclohexyl)methyl)adipate, dipentene dioxide, dicyclopentadiene diepoxide, tetrahydroepoxydiepoxide, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, 3,3'-(oxydimethylene)bis(3-ethyl)oxetane, ethoxytrimethylolpropane triacrylate, 4-tert-butylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, cyclotrimethylolpropane methyl acetal acrylate, and 2-phenoxyethyl acrylate.

8. The UV-curable dip-coated ink on the bottom layer of the measuring tape according to claim 1, characterized in that, The photoinitiator is one or a mixture of two or more of the following: 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate, bis(4-dodecylbenzene)iodohexafluoroantimonate, 4,4'-xylyliodonium hexafluorophosphate, and 2,4-diethylthioxanthrone.

9. The UV-curable dip-coating ink on the bottom layer of a measuring tape according to claim 1, characterized in that, The pigment is one or a mixture of two or more of benzidine yellow, titanium dioxide, Hansa yellow, phthalocyanine green, and phthalocyanine blue; The dispersant is one or a mixture of two or more of Tego685, Lubrizol 24000, BYK168, and BYK104; The surface additive is one or a mixture of two or more of BYK333, Tego432, Tego500, Tego920, Tego900, BYK3500, and BYK358N.

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