Modified epoxy acrylate resin and preparation method thereof, and crystal glue

Abstract

The invention provides modified epoxy acrylate resin and a preparation method thereof, and crystal glue. The preparation method of the modified epoxy acrylate resin comprises the following steps: A) mixing anhydride, hydroxyl acrylate, acrylic acid, epoxy resin, epoxy chloropropane, a catalyst, a polymerization inhibitor, an antioxidant and a solvent, and heating for reaction to obtain anhydride modified epoxy acrylate; wherein the mass ratio of the epoxy resin to the epoxy chloropropane is 1: (0.8-1.2); and B) mixing the phthalic anhydride modified epoxy acrylate obtained in the step A), polyisocyanate or a polyisocyanate prepolymer and a catalyst for reaction, and then adding a solvent for dilution to obtain the modified epoxy acrylate resin. The main body structure of the epoxy acrylate resin is changed, so that functional groups such as ester groups, straight-chain or cyclic carbon chain structures and the like in a special proportion are introduced between a benzene ring and an acrylic acid double bond in a bisphenol A structure, the volume shrinkage of a cured coating is greatly reduced, and the yellowing resistance is obviously improved.

Description

Technical Field

[0001] The invention relates to the field of chemical industry, and in particular to a modified epoxy acrylate resin and a preparation method thereof, and crystal glue. Background Art

[0002] Photocuring technology is a photoprocessing process that uses ultraviolet light of a certain wavelength to polymerize liquid epoxy acrylate resin and UV monomer into a solid state at high speed. Due to the unique technology and application advantages of photocuring, it has been rapidly and widely used in the fields of wood flooring manufacturing, photocurable inks, paper varnish, plastic gussets, etc., and is hailed as a new environmentally friendly new technology. When photocuring resin is cured, the volume shrinkage rate is generally larger than that of other resins after curing. Therefore, the shrinkage problem after curing has become a difficult problem in the photocuring industry, especially in the fields of drip glue and nail polish that require fast curing and high thickness.

[0003] The current epoxy curing process on the market is a low-energy UV double-sided curing process, with a film thickness of about 2-4cm. As we all know, such a high-thickness UV resin will shrink more after curing, and the yellowing will also be more serious. Summary of the invention

[0004] In view of this, the present invention provides a modified epoxy acrylate resin and a preparation method thereof, as well as crystal glue. The modified epoxy acrylate resin of the present invention can effectively improve the yellowing resistance and shrinkage of the glue.

[0005] The present invention provides a method for preparing a modified epoxy acrylate resin, comprising the following steps:

[0006] A) mixing anhydride, hydroxy acrylate, acrylic acid, epoxy resin, epichlorohydrin, a catalyst, a polymerization inhibitor, an antioxidant and a solvent, and heating the mixture to react to obtain anhydride-modified epoxy acrylate;

[0007] Wherein, the mass ratio of the epoxy resin to epichlorohydrin is 1:(0.8-1.2);

[0008] B) mixing the phthalic anhydride modified epoxy acrylate obtained in step A), polyisocyanate or polyisocyanate prepolymer and a catalyst for reaction, and then adding a solvent for dilution to obtain a modified epoxy acrylate resin.

[0009] Preferably, in step A), the amount of each material used is as follows, in parts by mass:

[0010]

[0011]

[0012] Preferably, in step A):

[0013] The hydroxy acrylate is at least one of hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate;

[0014] The epoxy resin is 128 epoxy resin;

[0015] The catalyst is at least one of triphenylphosphine, triethylamine, triethylbenzylammonium chloride and methylammonium chloride;

[0016] The polymerization inhibitor is at least one of hydroquinone, tert-butyl hydroquinone, p-hydroxyanisole, 2-methoxyhydroquinone and cupric chloride;

[0017] The antioxidant is hypophosphorous acid and / or BHT (2,6-di-tert-butyl-4-methylphenol);

[0018] The solvent is at least one of TPGDA, DPGDA, TMPTA, HDDA, PETA, NPGDA and DPHA.

[0019] Preferably, in step A), the temperature of the heating reaction is 100-105°C.

[0020] Preferably, in step B), the amount of each material used is as follows, in parts by mass:

[0021]

[0022] Preferably, in step B):

[0023] The catalyst is at least one of dibutyltin dilaurate, tetrabutyl titanate, organic bismuth and tin isooctanoate;

[0024] The solvent is at least one of HEA, HEMA, TPGDA, DPGDA, TMPTA, HDDA, PETA, NPGDA and DPHA;

[0025] The polyisocyanate or polyisocyanate prepolymer is hexamethylene diisocyanate trimer, a polyisocyanate monomer, or a prepolymer of a polyisocyanate monomer and a polyester / polyether polyol;

[0026] in,

[0027] The polyisocyanate monomer is at least one of toluene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate;

[0028] The polyester / polyether polyol is at least one of polyethylene glycol and polycaprolactone diol.

[0029] Preferably, step B) specifically comprises: cooling the anhydride-modified epoxy acrylate obtained in step A) to 80-85° C., adding a catalyst, stirring evenly, and then dripping polyisocyanate or polyisocyanate prepolymer, and after the dripping is completed, heating to 88-90° C. for insulation reaction, and adding a solvent for dilution when NCO% ≤ 0.1% to obtain a modified epoxy acrylate resin.

[0030] The present invention also provides a modified epoxy acrylate resin prepared by the preparation method described in the above technical scheme.

[0031] The present invention also provides a crystal glue drop, wherein the resin includes the modified epoxy acrylate resin described in the above technical solution.

[0032] Preferably, the raw materials for its preparation include, by weight:

[0033]

[0034] The benzene ring structure in bisphenol A and -C=C in acrylate are very likely to cause yellowing during UV curing, especially when the distance between the two is close, it is easy to form a π-π conjugation effect, and the yellowing is most obvious. The preparation method of the modified epoxy acrylate resin provided by the present invention firstly mixes acid anhydride, hydroxy acrylate, acrylic acid, epoxy resin, epichlorohydrin, catalyst, inhibitor, antioxidant and solvent, and heats to react to obtain acid anhydride modified epoxy acrylate; then the obtained acid anhydride modified epoxy acrylate, polyisocyanate or polyisocyanate prepolymer and catalyst are mixed and reacted, and then a solvent is added to dilute to obtain the modified epoxy acrylate resin. In the first step of the reaction, anhydride reacts with hydroxy acrylate to obtain acid, and the obtained acid and acrylic acid are reacted with a certain mass ratio of 128 epoxy resin and epichlorohydrin (1:0.8~1:1.2) to obtain anhydride-modified epoxy acrylate; it changes the main structure of the epoxy acrylate resin, and introduces a special proportion of ester groups, straight chain or cyclic carbon chain structures and other functional groups between the benzene ring and the acrylic double bond in the bisphenol A structure; firstly, this greatly prevents the two from forming a π-π conjugated effect, and secondly, the special proportion of functional groups interacts with the benzene ring and the double bond, which can reduce the tempering effect of the benzene ring, ease the cross-linking speed of the double bond, reduce its curing shrinkage, and absorb less ultraviolet rays while curing evenly, so that the yellowing is significantly improved. In the second step of the reaction, a special proportion of epoxy structure on the molecular chain is combined with urethane, and the molecular chain presents a network structure. After being formulated into a coating with a suitable viscosity, the volume shrinkage of the cured coating can be greatly reduced compared to ordinary light-curing resins. While having toughness, yellowing is relatively low, and it has good surface dryness and hardness.

[0035] The modified epoxy acrylate resin provided by the present invention is used in crystal glue dripping and is cured by low-energy LED with a curing energy of 100mJ / cm2 Below, the hardness is 80-85D and has a certain strength, and can show a faster curing speed, a lower shrinkage rate (shrinkage rate is below 1.2%), excellent yellowing resistance (yellowing degree ΔYI reaches below 1.61) and thermal stability. DETAILED DESCRIPTION

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0037] In this article, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0038] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] Herein, when it comes to numerical ranges, unless otherwise specified, the numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0040] In this article, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 80-85℃ means that the units of the left endpoint "80" and the right endpoint "85" are both ℃.

[0041] The present invention provides a method for preparing a modified epoxy acrylate resin, comprising the following steps:

[0042] A) mixing anhydride, hydroxy acrylate, acrylic acid, epoxy resin, epichlorohydrin, a catalyst, a polymerization inhibitor, an antioxidant and a solvent, and heating the mixture to react to obtain anhydride-modified epoxy acrylate;

[0043] B) mixing the anhydride-modified epoxy acrylate obtained in step A), polyisocyanate or polyisocyanate prepolymer and a catalyst for reaction, and then adding a solvent for dilution to obtain a modified epoxy acrylate resin.

[0044] [About Step A]:

[0045] A) Acid anhydride, hydroxy acrylate, acrylic acid, epoxy resin, epichlorohydrin, a catalyst, a polymerization inhibitor, an antioxidant and a solvent are mixed and heated for reaction to obtain anhydride-modified epoxy acrylate.

[0046] In the present invention, the acid anhydride is preferably at least one of phthalic anhydride, maleic anhydride and succinic anhydride.

[0047] In the present invention, the hydroxy acrylate is preferably at least one of hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate. The hydroxyethyl (meth)acrylate is hydroxyethyl acrylate and / or hydroxyethyl methacrylate. The hydroxypropyl (meth)acrylate is hydroxypropyl acrylate and / or hydroxypropyl methacrylate.

[0048] In the present invention, the acrylic acid is preferably acrylic acid.

[0049] In the present invention, the epoxy resin is preferably 128 epoxy resin, and more preferably GELR128 epoxy resin.

[0050] In the present invention, the catalyst is preferably at least one of triphenylphosphine, triethylamine, triethylbenzylammonium chloride and methylammonium chloride.

[0051] In the present invention, the polymerization inhibitor is preferably at least one of hydroquinone, tert-butyl hydroquinone, p-hydroxyanisole, 2-methoxyhydroquinone and cupric chloride.

[0052] In the present invention, the antioxidant is preferably hypophosphorous acid and / or BHT (2,6-di-tert-butyl-4-methylphenol).

[0053] In the present invention, the solvent is preferably an acrylate solvent, more preferably at least one of TPGDA (tripropylene glycol diacrylate), DPGDA (dipropylene glycol diacrylate), TMPTA (trimethylolpropane triacrylate), HDDA (1,6-hexanediol diacrylate), PETA (pentaerythritol triacrylate), NPGDA (neopentyl glycol diacrylate) and DPHA (dipentaerythritol hexaacrylate).

[0054] In the present invention, in step A), the amount of each material used is preferably as follows, in parts by mass:

[0055]

[0056]

[0057] in,

[0058] The amount of the acid anhydride used can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 30.5 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, and 40 parts.

[0059] The amount of the hydroxy acrylate can be specifically 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 20.5 parts, 21 parts, 22 parts, 23 parts, 24 parts, 24.5 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, and 30 parts.

[0060] The amount of acrylic acid used can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, and 20 parts.

[0061] The amount of the epoxy resin used can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, and 30 parts.

[0062] The amount of epichlorohydrin used can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts. In the present invention, the mass ratio of the epoxy resin to epichlorohydrin is preferably 1: (0.8-1.2), specifically 1: 0.8, 1: 0.9, 1: 1.0, 1: 1.1, 1: 1.2.

[0063] The amount of the catalyst used may specifically be 0.10 part, 0.15 part, 0.20 part, 0.25 part, 0.30 part, 0.35 part, 0.40 part, 0.45 part, 0.50 part, 0.55 part, 0.60 part, 0.65 part, 0.70 part, 0.75 part, 0.80 part, 0.85 part, 0.90 part, 0.95 part, or 1.0 part.

[0064] The dosage of the polymerization inhibitor may be 0.01 part, 0.02 part, 0.03 part, 0.04 part, 0.05 part, 0.06 part, 0.07 part, 0.08 part, 0.09 part, 0.10 part, 0.11 part, 0.12 part, 0.13 part, 0.14 part, 0.15 part, 0.16 part, 0.17 part, 0.18 part, 0.19 part, or 0.20 part.

[0065] The amount of the antioxidant used can be specifically 0.05 part, 0.10 part, 0.15 part, 0.20 part, 0.25 part, 0.30 part, 0.35 part, 0.40 part, 0.45 part, or 0.50 part.

[0066] The amount of the solvent used can specifically be 0.1 parts, 0.5 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts.

[0067] In one embodiment of the present invention, in step A), the materials are as follows:

[0068]

[0069] In another embodiment of the present invention, in step A), the materials are as follows:

[0070]

[0071] In another embodiment of the present invention, in step A), the materials are as follows:

[0072]

[0073]

[0074] In the present invention, anhydride, hydroxy acrylate, acrylic acid, epoxy resin, epichlorohydrin, catalyst, inhibitor, antioxidant and solvent are mixed and heated to react. The above operation can be carried out in a reactor; specifically, the above materials are put into a reactor and heated to the target temperature for insulation reaction. In the present invention, the temperature of the heating reaction is preferably 100-105°C, specifically 100°C, 101°C, 102°C, 103°C, 104°C, 105°C, and more preferably 100°C. The degree of the heating reaction is preferably until the acid value is ≤5mgKOH / g and the epoxy value is ≤2mgKOH / g.

[0075] In the above reaction process, acid anhydride reacts with hydroxy acrylate to obtain acid, and the obtained acid and acrylic acid react with a certain mass ratio of 128 epoxy resin and epichlorohydrin (1:0.8 to 1:1.2) to obtain acid anhydride modified epoxy acrylate.

[0076] [About step B]:

[0077] B) mixing the anhydride-modified epoxy acrylate obtained in step A), polyisocyanate or polyisocyanate prepolymer and a catalyst for reaction, and then adding a solvent for dilution to obtain a modified epoxy acrylate resin.

[0078] In the present invention, the catalyst is preferably at least one of dibutyltin dilaurate, tetrabutyl titanate, organic bismuth and tin isooctanoate.

[0079] In the present invention, the solvent is preferably at least one of HEA (2-hydroxyethyl acrylate), HEMA (2-hydroxyethyl methacrylate), TPGDA (tripropylene glycol diacrylate), DPGDA (dipropylene glycol diacrylate), TMPTA (trimethylolpropane triacrylate), HDDA (1,6-hexanediol diacrylate), PETA (pentaerythritol triacrylate), NPGDA (neopentyl glycol diacrylate), and DPHA (dipentaerythritol hexaacrylate).

[0080] In the present invention, the polyisocyanate or polyisocyanate prepolymer is preferably hexamethylene diisocyanate trimer, a polyisocyanate monomer, or a prepolymer of a polyisocyanate monomer and a polyester / polyether polyol. Wherein, the polyisocyanate monomer is preferably at least one of toluene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate (IPDI). The polyester / polyether polyol is preferably at least one of polyethylene glycol and polycaprolactone diol.

[0081] The prepolymer of the polyisocyanate monomer and the polyester / polyether polyol is preferably prepared by the following method: the polyisocyanate monomer, the solvent and the catalyst are mixed, the polyester / polyether polyol is added dropwise at a temperature below 40°C, and after the addition is completed, the temperature is raised to 80-85°C for reaction for 2-6 hours to obtain the prepolymer. Specifically, the control of the reaction end point is as follows: when the NCO value of the reactant reaches the theoretical value, the temperature is lowered to below 30°C, the reaction is terminated, and the polyisocyanate prepolymer is obtained.

[0082] The mass ratio of the polyisocyanate monomer to the polyester / polyether polyol is preferably 1:(1.23-2.25), specifically 1:1.23, 1:1.25, 1:1.30, 1:1.40, 1:1.50, 1:1.60, 1:1.70, 1:1.80, 1:1.90, 1:2.00, 1:2.10, 1:2.20, 1:2.25. The solvent is preferably at least one of HDDA (1,6 hexanediol diacrylate), TPGDA (tripropylene glycol diacrylate), and DPGDA (dipropylene glycol diacrylate). The mass ratio of the solvent to the polyisocyanate monomer is preferably (0.8-1.2):1, specifically 0.8:1, 0.9:1, 1.0:1, 1.1:1, and 1.2:1. The catalyst is preferably at least one of dibutyltin dilaurate, tin isooctanoate, and bismuth isooctanoate. The mass ratio of the catalyst to the polyisocyanate monomer is preferably (0.005-0.01):1, specifically 0.005:1, 0.006:1, 0.007:1, 0.008:1, 0.009:1, 0.01:1.

[0083] In the present invention, in step B), the amount of each material used is preferably as follows, in parts by mass:

[0084]

[0085] in,

[0086] The amount of the anhydride-modified epoxy acrylate obtained in step A) can be specifically 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, 80 parts, 81 parts, 82 parts, 83 parts, 84 parts, 85 parts, 86 parts, 87 parts, 88 parts, 89 parts, and 90 parts.

[0087] The amount of the catalyst used may specifically be 0.01 part, 0.02 part, 0.03 part, 0.04 part, 0.05 part, 0.06 part, 0.07 part, 0.08 part, 0.09 part, 0.10 part, 0.11 part, 0.12 part, 0.13 part, 0.14 part, 0.15 part, 0.16 part, 0.17 part, 0.18 part, 0.19 part, or 0.20 part.

[0088] The amount of the polyisocyanate or polyisocyanate prepolymer can be specifically 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, or 22 parts.

[0089] The amount of the solvent used can be specifically 1 part, 2 parts, 3 parts, 4 parts, 4.95 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, and 15 parts.

[0090] In some embodiments of the present invention, in step B), the materials are as follows:

[0091]

[0092] In the present invention, step B) preferably specifically comprises: cooling the anhydride-modified epoxy acrylate obtained in step A) to 80-85° C., adding a catalyst, stirring evenly, and then dripping polyisocyanate or polyisocyanate prepolymer, and after the dripping is completed, heating to 88-90° C. for insulation reaction, and adding a solvent for dilution when NCO% is ≤0.1% to obtain a modified epoxy acrylate resin.

[0093] in,

[0094] The cooling temperature of 80-85°C can be specifically 80°C, 81°C, 82°C, 83°C, 84°C, and 85°C. After cooling to the above temperature, add a catalyst and stir evenly, then start to drip polyisocyanate or polyisocyanate prepolymer (polyisocyanate or polyisocyanate prepolymer is pre-installed in a dropping tank), and start timing from the start of dripping. It is preferred to control the time to complete the dripping to be 0.8-1.2h, specifically 0.8h, 0.9h, 1.0h, 1.1h, and 1.2h. During the above process, the system temperature is maintained at 80-85°C. After the dripping is completed, the temperature is raised, and the target temperature is 88-90°C, specifically 88°C, 89°C, 90°C, and more preferably 90°C. After heating to the above target temperature, the reaction is kept warm for about 3 hours. The reaction end point is when NCO% ≤ 0.1% in the system. After reaching the end point, solvent is added for dilution, and the temperature is lowered and the material is discharged to obtain a modified epoxy acrylate resin product. The modified epoxy acrylate resin product is a polyurethane modified epoxy acrylate resin.

[0095] The present invention also provides a modified epoxy acrylate resin prepared by the preparation method described in the above technical scheme.

[0096] The present invention also provides a crystal drop method, wherein the resin is the modified epoxy acrylate resin described in the above technical solution.

[0097] In the present invention, preferably, the raw materials for preparing the crystal glue include, by parts by mass:

[0098]

[0099] in,

[0100] The modified epoxy acrylate resin may be used in an amount of 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, or 80 parts.

[0101] The monomer is preferably at least one of HEMA (2-hydroxyethyl methacrylate), HDDA (1,6-hexanediol diacrylate), and HEA (hydroxyethyl acrylate), and more preferably HEMA. The amount of the monomer used can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, or 40 parts.

[0102] The initiator is preferably at least one of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), photoinitiator 1173 (2-hydroxy-2-methyl-1-phenyl-1-propanone), and 184 (1-hydroxycyclohexyl phenyl ketone), and more preferably TPO. The amount of the initiator used can be 0.5 parts, 1.0 parts, 1.5 parts, or 2.0 parts.

[0103] The polymerization inhibitor is preferably 510 (N-nitrosophenylhydroxylamine aluminum salt). The dosage of the polymerization inhibitor can be 0.1 part or 0.2 part.

[0104] The thiol is preferably at least one of PEMP (pentaerythritol tetrakis (3-mercaptopropionate)) and TMPMP (trimethylolpropane tris (3-mercaptopropionate)). The amount of the thiol can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, or 8 parts.

[0105] The benzene ring structure in bisphenol A and -C=C in acrylate are very likely to cause yellowing during UV curing, especially when the distance between the two is close, it is easy to form a π-π conjugation effect, and the yellowing is most obvious. The preparation method of the modified epoxy acrylate resin provided by the present invention firstly mixes acid anhydride, hydroxy acrylate, acrylic acid, epoxy resin, epichlorohydrin, catalyst, inhibitor, antioxidant and solvent, and heats to react to obtain acid anhydride modified epoxy acrylate; then the obtained acid anhydride modified epoxy acrylate, polyisocyanate or polyisocyanate prepolymer and catalyst are mixed and reacted, and then a solvent is added to dilute to obtain the modified epoxy acrylate resin. In the first step of the reaction, anhydride reacts with hydroxy acrylate to obtain acid, and the obtained acid and acrylic acid are reacted with a certain mass ratio of 128 epoxy resin and epichlorohydrin (1:0.8~1:1.2) to obtain anhydride-modified epoxy acrylate; it changes the main structure of the epoxy acrylate resin, and introduces a special proportion of ester groups, straight chain or cyclic carbon chain structures and other functional groups between the benzene ring and the acrylic double bond in the bisphenol A structure; firstly, this greatly prevents the two from forming a π-π conjugated effect, and secondly, the special proportion of functional groups interacts with the benzene ring and the double bond, which can reduce the tempering effect of the benzene ring, ease the cross-linking speed of the double bond, reduce its curing shrinkage, and absorb less ultraviolet rays while curing evenly, so that the yellowing is significantly improved. In the second step of the reaction, a special proportion of epoxy structure on the molecular chain is combined with urethane, and the molecular chain presents a network structure. After being formulated into a coating with a suitable viscosity, the volume shrinkage of the cured coating can be greatly reduced compared to ordinary light-curing resins. While having toughness, yellowing is relatively low, and it has good surface dryness and hardness.

[0106] The modified epoxy acrylate resin provided by the present invention is used in crystal glue dripping and is cured by low-energy LED with a curing energy of 100mJ / cm 2 Below, the hardness is 80-85D and has a certain strength, and can show a faster curing speed, a lower shrinkage rate (shrinkage rate is below 1.2%), excellent yellowing resistance (yellowing degree ΔYI reaches below 1.61) and thermal stability.

[0107] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0108] Example 1

[0109] 1. Preparation of modified epoxy acrylate resin (mass ratio of 128 epoxy to epichlorohydrin 1:0.8)

[0110] A) putting phthalic anhydride, hydroxyethyl acrylate, acrylic acid, GELR128 epoxy resin, epichlorohydrin, catalyst triphenyl phosphine, inhibitor p-hydroxyanisole, antioxidant hypophosphorous acid and solvent into a reaction kettle, heating to 100° C. and keeping the temperature for reaction until the acid value is ≤5 mgKOH / g and the epoxy value is ≤2 mgKOH / g, to obtain phthalic anhydride modified epoxy acrylate;

[0111] The amount of each material is as follows:

[0112]

[0113] B) cooling the anhydride modified epoxy acrylate obtained in step A) to 80° C., adding a catalyst dibutyltin dilaurate, stirring for about 10 minutes to make it evenly mixed, and then dropping IPDI into the system through a dropping tank, timing when the dropping starts, controlling the dropping to be completed within 1 hour, and maintaining the temperature at 80-85° C. during the process. After the dropping is completed, the temperature is raised to 90° C. and kept for reaction for about 3 hours. When NCO% is measured to be ≤0.1%, HDDA is added to dilute, and the temperature is lowered to discharge the material to obtain a modified epoxy acrylate resin;

[0114] The amount of each material is as follows:

[0115]

[0116] 2. Preparation of crystal glue:

[0117] raw material:

[0118]

[0119] preparation:

[0120] The initiator TPO is dissolved in the monomer HEMA, and resin, thiol, and inhibitor are added to obtain crystal glue.

[0121] Example 2

[0122] 1. Preparation of modified epoxy acrylate resin (mass ratio of 128 epoxy to epichlorohydrin 1:1)

[0123] A) putting phthalic anhydride, hydroxyethyl acrylate, acrylic acid, GELR128 epoxy resin, epichlorohydrin, catalyst triphenyl phosphine, inhibitor p-hydroxyanisole, antioxidant hypophosphorous acid and solvent into a reaction kettle, heating to 100° C. and keeping the temperature for reaction until the acid value is ≤5 mgKOH / g and the epoxy value is ≤2 mgKOH / g, to obtain phthalic anhydride modified epoxy acrylate;

[0124] The amount of each material is as follows:

[0125]

[0126]

[0127] B) cooling the anhydride modified epoxy acrylate obtained in step A) to 80° C., adding a catalyst dibutyltin dilaurate, stirring for about 10 minutes to make it evenly mixed, and then dropping IPDI into the system through a dropping tank, timing when the dropping starts, controlling the dropping to be completed within 1 hour, and maintaining the temperature at 80-85° C. during the process. After the dropping is completed, the temperature is raised to 90° C. and kept for reaction for about 3 hours. When NCO% is measured to be ≤0.1%, HDDA is added to dilute, and the temperature is lowered to discharge the material to obtain a modified epoxy acrylate resin;

[0128] The amount of each material is as follows:

[0129]

[0130] 2. Preparation of crystal glue:

[0131] raw material:

[0132]

[0133] preparation:

[0134] The initiator TPO is dissolved in the monomer HEMA, and resin, thiol, and inhibitor are added to obtain crystal glue.

[0135] Example 3

[0136] 1. Preparation of modified epoxy acrylate resin (mass ratio of 128 epoxy to epichlorohydrin 1:1.2)

[0137] A) putting phthalic anhydride, hydroxyethyl acrylate, acrylic acid, GELR128 epoxy resin, epichlorohydrin, catalyst triphenyl phosphine, inhibitor p-hydroxyanisole, antioxidant hypophosphorous acid and solvent into a reaction kettle, heating to 100° C. and keeping the temperature for reaction until the acid value is ≤5 mgKOH / g and the epoxy value is ≤2 mgKOH / g, to obtain phthalic anhydride modified epoxy acrylate;

[0138] The amount of each material is as follows:

[0139]

[0140]

[0141] B) cooling the anhydride modified epoxy acrylate obtained in step A) to 80° C., adding a catalyst dibutyltin dilaurate, stirring for about 10 minutes to make it evenly mixed, and then dropping IPDI into the system through a dropping tank, timing when the dropping starts, controlling the dropping to be completed within 1 hour, and maintaining the temperature at 80-85° C. during the process. After the dropping is completed, the temperature is raised to 90° C. and kept for reaction for about 3 hours. When NCO% is measured to be ≤0.1%, HDDA is added to dilute, and the temperature is lowered to discharge the material to obtain a modified epoxy acrylate resin;

[0142] The amount of each material is as follows:

[0143]

[0144] 2. Preparation of crystal glue:

[0145] raw material:

[0146]

[0147] preparation:

[0148] The initiator TPO is dissolved in the monomer HEMA, and resin, thiol, and inhibitor are added to obtain crystal glue.

[0149] Comparative Example 1

[0150] 1. Preparation of modified epoxy acrylate resin (mass ratio of 128 epoxy to epichlorohydrin 1:1.3)

[0151] The process was carried out in accordance with Example 3, except that the amount of epichlorohydrin in step A) was increased to 26 parts, so that the mass ratio of 128 epoxy to epichlorohydrin was 1:1.3.

[0152] 2. Preparation of crystal glue: same as Example 3.

[0153] Comparative Example 2

[0154] 1. Preparation of modified epoxy acrylate resin (mass ratio of 128 epoxy to epichlorohydrin 1:0.7)

[0155] The method was carried out in accordance with Example 1, except that the amount of epichlorohydrin in step A) was reduced to 14 parts, so that the mass ratio of 128 epoxy to epichlorohydrin was 1:0.7.

[0156] 2. Preparation of crystal glue: same as Example 1.

[0157] Comparative Example 3

[0158] The commercially available modified epoxy resin, model EM6316, is from Changxing Materials Industry Co., Ltd.

[0159] Product Testing :

[0160] Pour the crystal glue into a specific mold, irradiate it with a low-energy LED lamp with a power of 6W for 1 minute each, then demould to obtain a cured block (thickness 4cm). Observe and test the curing speed, whether there is shrinkage, whether the surface is dry, whether it is resistant to nail scratches, and test the surface hardness and yellowing resistance. Among them, the yellowing resistance test is as follows: the above-mentioned cured block is irradiated with a nail polish lamp (45W) for 15 minutes, and then the yellowing effect of the cured block before and after irradiation by the nail polish lamp is compared. The test results are shown in Table 1.

[0161] (1) Surface viscosity: Touch the surface of the cured block with your hands and fingers to judge the surface viscosity by the degree of stickiness.

[0162] (2) Hardness: Shore hardness.

[0163] (3) Yellowing resistance: The yellowing change ΔYI of the cured block before and after irradiation with a nail polish lamp is tested.

[0164] (4) Shrinkage: The volume change of the material before and after curing is tested. The ratio of volume change to initial volume is the shrinkage rate (%).

[0165] (5) Scratch resistance: Use a pencil hardness tester to test its scratch resistance level (pencil hardness means that this hardness cannot scratch the surface of the glue).

[0166] (6) Thermal stability: The cured block was baked at 80°C for 168 h, and the viscosity and appearance changes of the sample were tested.

[0167] Table 1: Test results

[0168]

[0169] It can be seen from the test results in Table 1 that the curing energy of the glue samples prepared by the resins obtained in Examples 1-3 of the present invention is 100mJ / cm 2The following is not sticky, the hardness is about 80-85D, it has a certain toughness, and there is no obvious shrinkage at high thickness (shrinkage rate is below 1.2%). The most important thing is that there is no obvious yellowing (yellowing variable ΔYI is below 1.61), excellent scratch resistance, normal appearance after heat treatment and viscosity change does not exceed 50%. Comparative Examples 1-3 have sticky hands, especially the surface of the commercially available modified epoxy resin in Comparative Example 3 is obviously sticky. Because the curing speed of Comparative Example 1 is too fast, it shows more obvious shrinkage and more obvious yellowing. Because the curing speed of Comparative Example 2 is relatively slow, the surface is slightly sticky, not resistant to scratching by nails, and there is obvious yellowing. The surface of the commercially available modified epoxy resin in Comparative Example 3 is obviously sticky, shrinks more seriously, has poor yellowing resistance, and is not resistant to scratching by nails.

[0170] In summary, the structures obtained by reacting 128 epoxy and epichlorohydrin with anhydride in a special ratio in Examples 1-3 have excellent non-stickiness, fast curing speed, excellent toughness and excellent yellowing resistance, and also have good thermal stability.

[0171] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for preparing a modified epoxy acrylate resin, characterized in that: The following steps are involved: A) mixing anhydride, hydroxy acrylate, acrylic acid, epoxy resin, epichlorohydrin, a catalyst, a polymerization inhibitor, an antioxidant and a solvent, and heating the mixture to react to obtain anhydride-modified epoxy acrylate; Wherein, the mass ratio of the epoxy resin to epichlorohydrin is 1:(0.8-1.2); B) mixing the phthalic anhydride modified epoxy acrylate obtained in step A), polyisocyanate or polyisocyanate prepolymer and a catalyst for reaction, and then adding a solvent for dilution to obtain a modified epoxy acrylate resin.

2. The preparation method according to claim 1, characterized in that: In step A), the amount of each material used is as follows by weight:

3. The preparation method according to claim 1, characterized in that: In step A): The hydroxy acrylate is at least one of hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate; The epoxy resin is 128 epoxy resin; The catalyst is at least one of triphenylphosphine, triethylamine, triethylbenzylammonium chloride and methylammonium chloride; The polymerization inhibitor is at least one of hydroquinone, tert-butyl hydroquinone, p-hydroxyanisole, 2-methoxyhydroquinone and cupric chloride; The antioxidant is hypophosphorous acid and / or BHT (2,6-di-tert-butyl-4-methylphenol); The solvent is at least one of TPGDA, DPGDA, TMPTA, HDDA, PETA, NPGDA and DPHA.

4. The preparation method according to claim 1, characterized in that: In step A), the temperature of the heating reaction is 100-105°C.

5. The preparation method according to claim 1, characterized in that: In step B), the amount of each material used is as follows by weight:

6. The preparation method according to claim 1, characterized in that: In step B): The catalyst is at least one of dibutyltin dilaurate, tetrabutyl titanate, organic bismuth and tin isooctanoate; The solvent is at least one of HEA, HEMA, TPGDA, DPGDA, TMPTA, HDDA, PETA, NPGDA and DPHA; The polyisocyanate or polyisocyanate prepolymer is hexamethylene diisocyanate trimer, a polyisocyanate monomer, or a prepolymer of a polyisocyanate monomer and a polyester / polyether polyol; in, The polyisocyanate monomer is at least one of toluene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate; The polyester / polyether polyol is at least one of polyethylene glycol and polycaprolactone diol.

7. The preparation method according to claim 1, characterized in that: Step B) specifically comprises: cooling the anhydride-modified epoxy acrylate obtained in step A) to 80-85° C., adding a catalyst, stirring evenly, and then dropping polyisocyanate or polyisocyanate prepolymer, and after the dropwise addition, heating to 88-90° C. for heat preservation and reaction, and adding a solvent for dilution when NCO% is ≤0.1% to obtain a modified epoxy acrylate resin.

8. A modified epoxy acrylate resin obtained by the preparation method according to any one of claims 1 to 7.

9. A crystal glue, characterized in that: The resin comprises the modified epoxy acrylate resin as claimed in claim 8.

10. The crystal glue according to claim 9, characterized in that: The raw materials for its preparation include, by weight:

Images