Preparation method and application of yellowing-resistant low-shrinkage-rate UV (ultraviolet) photocuring crystal drop glue

Abstract

The invention discloses a preparation method and application of yellowing-resistant low-shrinkage UV (ultraviolet) photocuring crystal glue. According to the invention, the antioxidant, the photoinitiator, the conventional acrylate monomer, the monomer containing the special functional group, the auxiliary agent and the light-cured resin are introduced, and the formula design and the process conditions are optimized, so that the crystal dripping glue with high transparency, excellent yellowing resistance and low shrinkage rate is prepared. The preparation method comprises the following steps: mixing and stirring the raw materials in stages under the conditions of proper temperature and rotating speed, and degassing in a vacuum environment to prepare the uniform and transparent drop glue. Regular spherical beads are formed on the surface of a wedding dress through a spraying process, and after UV light curing, the prepared crystal spherical decorative beads are high in transparency, good in glossiness, free of cracks and free of fogging. Compared with the prior art, the invention overcomes the defects of easy yellowing, obvious volume shrinkage and complex process of crystal dripping glue, and is suitable for development and application of high-end decorative materials.

Description

Technical Field

[0001] The present invention relates to a preparation method and application of a yellowing-resistant and low-shrinkage UV light-cured crystal glue, which is particularly suitable for wedding dress decoration, handicraft manufacturing and other high-transparency decorative materials. Background Art

[0002] Crystal glue is widely used in crafts and decorative materials due to its high transparency and good gloss. Early crystal glue was mainly based on epoxy resin, but it required two-component mixing and a long curing time, which made it cumbersome to use. In recent years, single-component UV-curing crystal glue has gradually become mainstream because it does not require mixing and can be cured quickly after 1-2 minutes of irradiation. However, this type of crystal glue still faces two key problems in practical applications:

[0003] 1. Easy to yellow: Long-term exposure to ultraviolet light or sunlight, unreacted double bonds oxidize and photoaging reactions cause the material to produce oxygen-containing compounds such as aldehydes and ketones, or form conjugated structures, resulting in color changes, affecting transparency and aesthetics. In addition, the initiator may generate colored impurities or their decomposition products during the polymerization process, especially under ultraviolet light, and its residues are prone to further decomposition, significantly accelerating the yellowing phenomenon.

[0004] 2. Obvious volume shrinkage: During the photocuring process, the intermolecular van der Waals force quickly transforms into covalent bonding, causing the molecular distance to shorten from about 0.3-0.5nm to about 0.154nm. Macroscopically, it manifests as a large volume shrinkage, which can easily cause the material to crack and warp, seriously affecting the performance and aesthetics of the crystal glue.

[0005] In the prior art, the volume shrinkage problem of photocurable crystal glue is often solved by reducing the concentration of reactive groups (such as filler method) or prolonging the stress relaxation time (such as introducing dynamic cross-linking bonds and adding chain transfer agents). However, these methods often lead to a decrease in the light transmittance of the material or a decrease in the curing speed, making it difficult to take into account both the high transparency and rapid curing characteristics of the crystal glue. After in-depth research, the inventors found that by increasing the double bond conversion rate and selecting a suitable initiator, the photo-oxidative degradation of the material can be effectively inhibited, and the yellowing resistance of the crystal glue can be significantly improved. At the same time, by selecting monomers with specific structures, a ring-opening reaction occurs under the initiation of free radicals, and the length of the covalent bond formed offsets the distance of the van der Waals force before the reaction, thereby reducing the shortening of the molecular distance during the photopolymerization process, significantly reducing the volume shrinkage rate, and achieving a zero-shrinkage curing effect.

[0006] Based on the above understanding, the present invention provides a UV light-cured crystal glue with yellowing resistance and low shrinkage and a preparation method thereof. The crystal glue can not only effectively solve the problem of yellowing easily under sunlight or ultraviolet light, so that the material can maintain high transparency for a long time, but also significantly reduce the volume shrinkage during UV curing, ensuring the dimensional stability and decorative effect of the material. Summary of the invention

[0007] The present invention aims at the shortcomings of the existing UV light-curing crystal glue dripping technology, and proposes a preparation method and application of UV light-curing crystal glue dripping with yellowing resistance and low shrinkage. By introducing a photoinitiator that does not produce yellowing photodegradation products, the double bond conversion efficiency in the UV light curing process is optimized, and the yellowing risk caused by double bond oxidation is significantly reduced; combined with monomers containing special functional groups, a ring-opening reaction is achieved under the initiation of free radicals, and the volume shrinkage caused by the change in molecular spacing during the curing process is effectively alleviated. This design not only significantly improves the anti-yellowing performance of the crystal glue dripping, reduces the volume shrinkage, but also ensures the high transparency and excellent mechanical properties of the material. In addition, the cleverly designed spraying and curing process accurately controls the viscosity of the glue liquid, the spraying height and the light curing time interval, and realizes the stable molding of the glue dripping beads during the spraying process and the perfect spherical shape after curing. The crystal glue dripping is particularly suitable for wedding dress decoration, handicraft manufacturing and other high-performance decorative materials. It has a broad market prospect and shows excellent performance and environmentally friendly characteristics.

[0008] Based on the above purpose, the present invention adopts the following technical solution:

[0009] The first aspect of the present invention provides a crystal glue having excellent yellowing resistance and low shrinkage, and the preparation method thereof is as follows: first, an antioxidant, a photoinitiator, a conventional acrylate monomer, a monomer containing a special functional group and an auxiliary agent are mixed, and stirred at a temperature of 40-50°C and a speed of 1200-1500r / min for 0.5-2h until the mixture is evenly mixed; then, a photocurable resin is added, and stirring is continued at a speed of 1200-1500r / min for 0.5-2h until the mixture is evenly mixed; finally, the mixture is placed in a vacuum environment and stirred fully to obtain the crystal glue.

[0010] The antioxidant is one or more of a phosphite antioxidant and a phenolic antioxidant. The phosphite antioxidants may include: triphenyl phosphite, tris(nonylphenyl)phosphite, poly(dipropylene glycol)phenylphosphite, diisobutyl diphosphite pentaerythritol, trioctyl phosphite, tridecyl phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, tris(dodecanol), dioctadecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-tert-butylphenol)-4,4'-biphenyl diphosphite, distearyl pentaerythritol diphosphite and tris(hexadecanol), and the phenolic antioxidants may include: 2,6-di-tert-butyl-p-cresol, tris(3,3-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 2,6-di-tert-butyl-4- methylphenol, 2,6-di-tert-butyl-p-ethylphenol, bis(3,5-di-tert-butyl-4-hydroxyphenyl) sulfide, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], 2,2'-thiobis(4-methyl-6-tert-butylphenol), 4,4'-thiobis(6-tert-butyl-o-cresol), 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate methyl ester], 2,5-di-tert-butylhydroquinone, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate n-octadecyl, and N,N'-1,6-hexamethylene-bis-[3,5-di-tert-butyl-4-hydroxyphenylpropionamide].

[0011] The photoinitiator is selected from at least one of the following: 907, ITX, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, 2-dimethylamino-2-benzyl-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, methyl benzoylformate, 2-isopropylthioxanthone or 2,4-diethylthioxanthone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0012] The conventional acrylate monomer is selected from at least one or more of the following: one or more of a monofunctional acrylate monomer, a difunctional acrylate monomer, and a multifunctional acrylate; wherein the monofunctional acrylate monomer may be: 2-phenoxyethyl methacrylate, benzyl acrylate, isobornyl acrylate, isobornyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, caprolactone-grafted hydroxyethyl acrylate, carbitol (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-(meth)acryloyloxyethoxy-2-hydroxypropyl phthalate, lauric acid (meth)acrylate, methoxylated polyethylene glycol (meth)acrylate, stearic acid (meth)acrylate, isodecyl (meth)acrylate, ethoxylated hydroxy (meth)acrylate, Glycidyl methacrylate, isooctyl (meth)acrylate and stearic (meth)acrylate, etc. The difunctional acrylate monomer can be: 1,6-hexanediol di(meth)acrylate, tripropylene glycol diacrylate, neopentyl glycol di(meth)acrylate, dioxanediol diacrylate, dipropylene glycol diacrylate, polyethylene glycol diacrylate, 2-hydroxyethyl methacrylate phosphate, ethoxylated bisphenol A dimethacrylate, diethylene glycol (meth)acrylate, and the multifunctional acrylate monomer can be: trimethylolpropane tri(meth)acrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, pentaerythritol triacrylate, ethylene (propylene)oxylated trimethylolpropane tri(meth)acrylate, propoxylated glycerol triacrylate, propoxylated pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, etc.

[0013] The monomer containing a special functional group is selected from at least one or more of the following: spiro orthoacid, spiro orthocarbonate, 2-vinylcyclopropane, bicyclic cyclopropyl acrylate and cyclic ketene acetal.

[0014] The auxiliary agent is selected from at least one or more of the following: leveling agent and defoaming agent. The leveling agent can be: 388, 320, 358N, 392, 399, BYK333, BYK306, etc., and the defoaming agent can be: 066N, A530, 6800, 141, 354.

[0015] The photocurable resin is selected from at least one or more of the following: one or more of polyurethane acrylate, polyester acrylate, and acrylated polyacrylate photocurable prepolymer.

[0016] Taking the total mass of the antioxidant, the photoinitiator, the conventional acrylate monomer, the acrylate monomer containing special functional groups, the auxiliary agent and the photocurable resin as 100%, the mass percentage content of the antioxidant is 0.05-0.3%, the mass percentage content of the photoinitiator is 2-10%, the mass percentage content of the conventional acrylate monomer is 5-50%, the mass percentage content of the acrylate monomer containing special functional groups is 5-30%, the mass percentage content of the auxiliary agent is 0.1-0.3%, and the mass percentage content of the photocurable resin is 5-60%.

[0017] In view of improving the antioxidant capacity and the stability of the product, the phosphite antioxidant is preferably one or more of triphenyl phosphite, tris(nonylphenyl)phosphite, poly(dipropylene glycol)phenyl phosphite, diphosphite pentaerythritol diisobutyl ester, etc., and the phenolic antioxidant is one or more of tetrakis(2,4-di-tert-butylphenol)-4,4'-biphenyl diphosphite, distearyl pentaerythritol diphosphite and tris(hexadecanol) ester, etc.

[0018] Considering the deep curing performance, surface drying effect and yellowing risk of photoinitiator decomposition products of crystal glue, the photoinitiator is preferably a combination of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide. 1-Hydroxycyclohexyl phenyl ketone has good deep curing performance and its decomposition products are not easy to cause yellowing, but its surface drying effect is slightly weaker; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide shows excellent surface drying effect, but its decomposition products may increase the risk of yellowing and lack deep curing ability. By using a reasonable proportion of combination, the curing performance and surface drying effect of UV glue can be improved while reducing the risk of yellowing and fogging caused by decomposition products, achieving an optimized balance of performance.

[0019] Taking into account the balance between heat release and curing speed, the control of internal stress during the curing process of the product, the consistency of surface and internal curing rates, and the need to reduce the impact of cracking on the appearance, as well as the potential impact of impurities in the monomer itself on yellowing, the preferred monofunctional acrylate active monomer is one or more of 2-phenoxyethyl methacrylate, benzyl acrylate, isobornyl acrylate, isobornyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and caprolactone-grafted hydroxyethyl acrylate.

[0020] Considering the need to adjust the viscosity of crystal glue and the requirement to improve the overall reaction rate, bifunctional acrylate monomers are preferred, which can effectively reduce the viscosity of the system and promote the reaction rate. At the same time, considering that acrylate monomers need to take into account the balance of curing speed, shrinkage, double bond crosslinking density and comprehensive performance of products, bifunctional acrylate monomers are preferably 1,6-hexanediol di(meth)acrylate, tripropylene glycol diacrylate, neopentyl glycol di(meth)acrylate, dioxane diol diacrylate, dipropylene glycol diacrylate, polyethylene glycol diacrylate. The acrylate monomer not only accelerates the curing reaction speed by increasing the double bond crosslinking density, but also significantly improves the anti-scratch performance of the product. At the same time, the flexible chain segments between its bifunctional groups can effectively relieve shrinkage stress, thereby controlling the shrinkage rate and ensuring the dimensional stability of the product. In addition, compared with multifunctional monomers, bifunctional acrylate monomers have a higher double bond conversion rate, which can reduce double bond residues and reduce the risk of yellowing caused by unreacted components.

[0021] Considering the comprehensive requirements of reducing the shrinkage of the photocurable material, improving the reaction activity, and maintaining excellent mechanical properties, the monomer containing a special functional group is preferably one or more of vinyl cyclopropane and bicyclopropyl acrylate monomers.

[0022] Taking into account the need to prevent Bénard cells from appearing on the surface of the crystal glue during the curing process, to improve the surface smoothness and flatness, and to avoid bubbles generated during the process, the leveling agent additive is preferably one or more of BYK 333 and BYK306, and the defoaming agent is preferably 066N or A530.

[0023] Taking into account the requirements for low shrinkage, low yellowing and low heat release in the production process of crystal glue, as well as the need to balance heat release and shrinkage during the curing process, while ensuring a high C=C double bond conversion rate, reducing the risk of yellowing caused by unreacted components, avoiding excessive heat release and shrinkage due to excessively high double bond functionality, and slow curing speed due to too low double bond functionality; at the same time, it is also necessary to control the molecular weight range to reduce the viscosity of the glue and make it easy to operate and use. The light-curing resin is preferably an acrylated polyacrylate with a molecular weight between 3000-6000 and a double bond functionality between 1-3.

[0024] In a second aspect, the present invention provides the application of crystal glue on wedding dresses. The prepared crystal glue has the characteristics of good yellowing resistance and low shrinkage rate, and is easy to be applied in various fields.

[0025] (1) Spraying crystal glue to form spherical beads:

[0026] Prepare the spraying equipment, select a nozzle with a nozzle size of 0.5-1mm, and spray the crystal glue evenly on the surface of the wedding dress. During the spraying process, keep the nozzle 5-10cm away from the surface of the wedding dress, and operate in a dot-spraying manner, spraying one by one to form spherical drop-shaped glue beads, ensuring that each bead is independent and evenly distributed on the surface of the wedding dress.

[0027] (2) UV curing to form crystal beads:

[0028] After spraying, wait for 5-10 seconds, and then place the wedding dress under a 1000-2000W UV-LED light source for curing to ensure that the glue beads remain in their original spherical state. The wavelength of the light source is 365-405nm, and it is kept 10-20cm away from the surface of the wedding dress to ensure that each glue bead is evenly exposed to light. The curing time is adjusted according to the size of the glue beads: small beads (diameter 0.5-1mm): illumination time is 10-30s; large beads (diameter 1-2mm): illumination time is 30-60s.

[0029] The inventors have found through in-depth research that in the process of preparing crystal glue, process parameters such as spray height, glue viscosity, and the time difference between spraying and light curing have an important influence on the effect of glue forming spherical beads. When the viscosity of the glue is high, the spray height generally needs to be high, so that the balance between gravity and surface tension in the dripping process can be fully utilized, so that the glue naturally forms a regular spherical structure during the spraying process. When the viscosity of the glue is low, the spray height can be appropriately reduced to avoid excessive diffusion of the glue and affect the shape. In addition, the time difference between spraying and light curing is also crucial. For low-viscosity glue, light curing is required to be performed quickly after spraying to avoid the phenomenon of the glue flowing or penetrating the wedding dress fabric before it is cured, thereby ensuring the integrity and stability of the glue beads. However, if the light curing time is too early, the sphere may not be fully formed; if the light curing time is too late, the glue may penetrate into the fabric, affecting the final decorative effect. Therefore, reasonable control of the spray height, glue viscosity, and curing time after spraying is the key to achieving good shape and performance of crystal glue beads.

[0030] Compared with the prior art, the present invention has one of the following advantages:

[0031] 1) By rationally introducing photoinitiators that do not produce yellowing photodegradation products, the double bond conversion efficiency during UV curing is optimized, effectively reducing the risk of yellowing caused by double bond oxidation, thereby significantly improving the yellowing resistance of the material;

[0032] 2) By using monomers containing special functional groups, a ring-opening reaction is achieved under the initiation of free radicals, which effectively reduces the volume shrinkage rate during the polymerization reaction and improves the dimensional stability of the product after curing;

[0033] 3) By adjusting the process parameters such as glue viscosity, spray height and light curing time difference, it is ensured that the glue forms regular spherical crystal beads during the spraying process to avoid sagging and penetration problems, thereby achieving higher decorativeness and aesthetics.

[0034] 4) The preparation method of the present invention comprises mixing and stirring the raw materials in stages under suitable temperature and rotation speed conditions, and degassing under a vacuum environment to obtain a uniform and transparent drop glue. The drop glue of the present invention forms regular spherical beads on the surface of the wedding dress through a spraying process. After UV light curing, the obtained crystal spherical decorative beads have high transparency, good gloss, no cracks, and no fog. Compared with the prior art, the present invention overcomes the shortcomings of crystal drop glue that is easy to yellow, has obvious volume shrinkage, and has a complicated process, and is suitable for the development and application of high-end decorative materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a photo of the effect of the crystal glue prepared in Example 1 being applied to wedding dress decoration;

[0036] Figure 2 This is a photo of the effect of the crystal glue prepared in Comparative Example 3 being applied to wedding dress decoration;

[0037] Figure 3 This is a photo of the effect of the crystal glue prepared in Comparative Example 4 being applied to wedding dress decoration; DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the present invention, unless otherwise specified, all raw materials can be purchased from the market or are commonly used in the industry. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art.

[0040] Embodiment 1:

[0041] Antioxidant triphenyl phosphite (0.2g), photoinitiator (1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, mass ratio of 1:1) (5g), conventional acrylate monomer (1,6-hexanediol di(meth)acrylate and hydroxyethyl acrylate, mass ratio of 1:2) (20g), bicyclic cyclopropyl acrylate containing special functional groups (10g) and additives (BYK333 and A530, mass ratio of 1:1) (0.2g), acrylated polyacrylate photocurable resin (EB 230, Allnex, molecular weight of 3000-6000, double bond functionality of 1-3) 64.6g. First, antioxidant, photoinitiator, conventional acrylate monomer, monomer containing special functional group and auxiliary agent are mixed, stirred at 45℃ and 1350r / min for 1h until the mixture is evenly mixed; then, light curing resin is added, and stirring is continued at 1350r / min for 1h until the mixture is evenly mixed, and finally, the mixture is placed in a vacuum environment and stirred fully to obtain crystal glue. The properties of the crystal glue obtained by the above method are shown in Table 1.

[0042] The performance data of the crystal epoxy product prepared by the above preparation method using the crystal epoxy prepared in Example 1 as a raw material are shown in Table 2.

[0043] The effect of the crystal glue prepared in Example 1 applied to wedding dress decoration is shown in the following photo: Figure 1 shown.

[0044] Performance characteristics: The crystal spherical decorative beads have regular surface formation, are colorless, highly transparent, high gloss, no cracks, and no fog, and have excellent decorative effects.

[0045] Comparative Example 1:

[0046] Antioxidant triphenyl phosphite (0.2g), photoinitiator (1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, mass ratio 1:1) (5g), conventional acrylate monomer (1,6-hexanediol di(meth)acrylate and hydroxyethyl acrylate, mass ratio 1:2) (20g) and auxiliary agent (BYK333 and A530, mass ratio 1:1) (0.2g), acrylated polyacrylate photocurable resin (EB 230, Allnex) 64.6g. The properties of the crystal glue prepared by the above method are shown in Table 1.

[0047] The performance data of the crystal epoxy product prepared by the above preparation method using the crystal epoxy prepared in Example 1 as a raw material are shown in Table 2.

[0048] Performance characteristics: Without adding special functional group monomers, dense cracks are formed on the surface of the cured crystal glue, resulting in a significant decrease in the transparency and glossiness of the cured crystal glue.

[0049] Comparative Example 2:

[0050] Antioxidant triphenyl phosphite (0.2g), photoinitiator (1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, mass ratio 1:1) (5g), conventional acrylate monomer (dipentaerythritol hexaacrylate and hydroxyethyl acrylate, mass ratio 1:2) (20g), bicyclic cyclopropyl acrylate containing special functional groups (10g) and auxiliary agent (BYK333 and A530, mass ratio 1:1) (0.2g), acrylated polyacrylate photocurable resin (EB 230, Allnex) 64.6g. The properties of the crystal glue prepared by the above method are shown in Table 1.

[0051] The performance data of the crystal epoxy product prepared by the above preparation method using the crystal epoxy prepared in Example 1 as a raw material are shown in Table 2.

[0052] Performance characteristics: The multifunctional monomer dipentaerythritol hexaacrylate is selected. Dense cracks are formed on the surface of the cured crystal glue, which leads to a significant decrease in the transparency and glossiness of the cured crystal glue. At the same time, the cured crystal glue appears yellow.

[0053] Comparative Example 3:

[0054] Antioxidant triphenyl phosphite (0.2g), photoinitiator (1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, mass ratio 1:1) (5g), conventional acrylate monomer (1,6-hexanediol di(meth)acrylate and hydroxyethyl acrylate, mass ratio 1:2) (20g), bicyclic cyclopropyl acrylate containing special functional groups (10g), acrylated polyacrylate photocurable resin (EB 230, Allnex) 64.6g. The properties of the crystal glue prepared by the above method are shown in Table 1.

[0055] The performance data of the crystal epoxy product prepared by the above preparation method using the crystal epoxy prepared in Example 1 as a raw material are shown in Table 2.

[0056] The effect of the crystal glue prepared in comparative example 3 applied to wedding dress decoration is shown in the following figure: Figure 2 shown.

[0057] Performance characteristics: No additives are added. A large number of bubbles are formed inside the solidified crystal glue, and irregular pits are formed on the surface, which significantly reduces the transparency and glossiness of the solidified crystal glue.

[0058] Comparative Example 4:

[0059] Antioxidant triphenyl phosphite (0.2g), photoinitiator (907 and ITX, mass ratio 1:1) (5g), conventional acrylate monomer (1,6-hexanediol di(meth)acrylate and hydroxyethyl acrylate, mass ratio 1:2) (20g), bicyclic cyclopropyl acrylate containing special functional groups (10g) and auxiliary agent (BYK333 and A530, mass ratio 1:1) (0.2g), acrylated polyacrylate photocurable resin (EB 230, Allnex) 64.6g. The properties of the crystal glue prepared by the above method are shown in Table 1.

[0060] The performance data of the crystal epoxy product prepared by the above preparation method using the crystal epoxy prepared in Example 1 as a raw material are shown in Table 2.

[0061] The effect of the crystal glue prepared in comparative example 4 applied to wedding dress decoration is shown in the following figure: Figure 3 shown.

[0062] Performance characteristics: When other types of initiators are selected, the cured crystal glue shows a significant yellow color.

[0063] Embodiment 2:

[0064] The antioxidant tetrakis (2,4-di-tert-butylphenol)-4,4'-biphenyl diphosphite (0.3g), the photoinitiator (1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, mass ratio 1:2) (4g), the conventional acrylate monomer (tripropylene glycol diacrylate and hydroxypropyl acrylate, mass ratio 1:2) (21g), the bicyclic cyclopropyl acrylate containing special functional groups (10g), the auxiliary agent (BYK333 and A530, mass ratio 2:1) (0.2g), and the acrylic acid ester polyacrylate photocurable resin (EB 230, Allnex) 64.5g. The properties of the crystal glue prepared by the above method are shown in Table 1.

[0065] The performance data of the crystal epoxy product prepared by the above preparation method using the crystal epoxy prepared in Example 2 as a raw material are shown in Table 2.

[0066] Performance characteristics: The crystal spherical decorative beads have regular surface formation, are colorless, highly transparent, highly glossy, crack-free, and non-fogging, and have excellent decorative effects.

[0067] Table 1

[0068]

[0069] Table 2

[0070]

[0071] It should be emphasized that although the above description only shows the preferred embodiments of the present invention, it is not intended to limit the scope of the present invention. Even though the present invention has been described in detail through specific embodiments, it is still possible for those skilled in the art to modify or replace the technical solutions described within the spirit and principle of the present invention. Therefore, the actual protection scope of the present invention should be defined according to the attached claims.

Claims

1. A method for preparing a yellowing-resistant and low-shrinkage UV-curable crystal glue, characterized in that: The following steps are involved: First, an antioxidant, a photoinitiator, an acrylate monomer, a monomer containing a special functional group and an additive are mixed until the mixture is uniformly mixed; Then, add the light-curing resin and continue mixing until the mixture is well mixed; Finally, the mixture is placed in a vacuum environment and fully stirred to obtain a UV light-cured crystal glue having yellowing resistance and low shrinkage.

2. The preparation method according to claim 1, characterized in that: The antioxidant is one or more of triphenyl phosphite, tri(nonylphenyl)phosphite, poly(dipropylene glycol)phenyl phosphite, diisobutyl pentaerythritol diphosphite, tetrakis(2,4-di-tert-butylphenol)-4,4'-biphenyl diphosphite, distearyl pentaerythritol diphosphite, and tri(hexadecanol) ester.

3. The preparation method according to claim 1, characterized in that: The photoinitiator is a combination of 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

4. The preparation method according to claim 1, characterized in that: The acrylate monomer is one or more of a monofunctional acrylate reactive monomer and a bifunctional acrylate monomer.

5. The preparation method according to claim 4, characterized in that: The monofunctional acrylate active monomer is one or more of 2-phenoxyethyl methacrylate, benzyl acrylate, isobornyl acrylate, isobornyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and caprolactone-grafted hydroxyethyl acrylate; The bifunctional acrylate monomer is one or more of 1,6-hexanediol di(meth)acrylate, tripropylene glycol diacrylate, neopentyl glycol di(meth)acrylate, dioxanediol diacrylate, dipropylene glycol diacrylate, and polyethylene glycol diacrylate.

6. The preparation method according to claim 1, characterized in that: The monomer containing special functional groups is one or two of vinyl cyclopropane and bicyclic cyclopropyl acrylate monomers.

7. The preparation method according to claim 1, characterized in that: The auxiliary agent is one or both of a leveling agent and a defoaming agent; The leveling agent is one or both of leveling agent BYK 333 and leveling agent BYK306; The defoaming agent is one or both of defoaming agent 066N and defoaming agent A530.

8. The preparation method according to claim 1, characterized in that: The photocurable resin is an acrylated polyacrylate with a molecular weight of 3000-6000 and a double bond functionality of 1-3.

9. The preparation method according to claim 1, characterized in that: The conditions for mixing the antioxidant, photoinitiator, acrylate monomer, monomer containing special functional groups and additives are: stirring at a temperature of 40-50°C and a speed of 1200-1500r / min for 0.5-2h; The mixing conditions are as follows: stirring at a speed of 1200-1500 r / min for 0.5-2 h.

10. Use of the yellowing-resistant, low-shrinkage UV-curable crystal glue prepared by the preparation method according to any one of claims 1 to 9 in the surface decoration of wedding dresses.

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