Jelly glue as well as preparation method and application thereof

Abstract

The invention provides jelly glue as well as a preparation method and application thereof. The jelly glue comprises a first pressure-sensitive adhesive layer, a middle layer and a second pressure-sensitive adhesive layer which are sequentially arranged, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer respectively and independently comprise the following components in parts by weight: 90-102 parts of low glass transition temperature acrylic resin and 0.1-0.5 part of a first photoinitiator; the middle layer is prepared from the following components in parts by weight: 90 to 102 parts of acrylic resin with high glass transition temperature, 0.1 to 0.5 part of second photoinitiator and 0.01 to 0.5 part of curing agent; the glass transition temperature of the acrylic resin with low glass transition temperature is-40 to 0 DEG C; the glass transition temperature of the acrylic resin with high glass transition temperature is 0-32 DEG C. The jelly glue disclosed by the invention has the advantages of excellent adhesive property, high shear strength, low odor, difficulty in displacement and low residual glue rate.

Description

Technical Field

[0001] This invention belongs to the field of adhesive materials technology, specifically relating to a jelly adhesive, its preparation method, and its application. Background Technology

[0002] The nail art and wearable decoration (such as temporary tattoos and skin-adhesive layers for electronic devices) have developed rapidly in recent years, leading to a growing demand for aesthetically pleasing, convenient, and safe adhesive materials. Jelly glue (also known as crystal stickers or removable glue), as a popular adhesive medium, has been widely used in these fields due to its transparency, high plasticity, and ease of application.

[0003] However, most mainstream traditional gel nail stickers or wearable products on the market currently suffer from the following significant problems: Residue: When removed, they easily leave sticky residue that is difficult to remove from the adhered surface (such as nails or skin) or decorations, affecting aesthetics and user experience, and may even damage nails or skin. Insufficient Adhesion: Insufficient initial tack (initial adhesion) or long-term adhesion causes nail stickers or wearables to easily shift, lift, or even fall off during daily activities, especially when exposed to water, oil, or friction. Low Overall Strength: The gel itself is not strong enough, making it prone to tearing, deformation, or breakage under stress (such as nail scratching or pulling of the wearable), affecting lifespan and decorative effect. Odor: Some products release irritating odors during production or use, affecting user comfort and health experience.

[0004] The root cause of these problems largely stems from the limitations of traditional jelly adhesive material formulations and structures. Single-component or simple-structured colloids often struggle to simultaneously achieve key performance indicators such as high viscosity, high strength, easy removal with no residue, and low odor. For example, increasing viscosity may result in difficult-to-remove residue; increasing strength may sacrifice flexibility and adhesion; and some performance-enhancing additives may introduce unpleasant odors.

[0005] Therefore, there is an urgent need in the field to provide a jelly adhesive that is strong and reliable, not easily displaced, has high strength, can be removed cleanly without residue, and has a low or no odor, in order to meet the high-performance requirements of fields such as nail art and wearables. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a jelly adhesive, its preparation method, and its applications. The jelly adhesive solves the problems of traditional nail gels, such as residue, poor adhesion, low strength, easy displacement, and strong odor.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a jelly adhesive comprising a first pressure-sensitive adhesive layer, an intermediate layer, and a second pressure-sensitive adhesive layer disposed sequentially; by weight, the first and second pressure-sensitive adhesive layers each independently comprise 90-102 parts of a low glass transition temperature acrylic resin and 0.1-0.5 parts of a first photoinitiator; by weight, the intermediate layer comprises 90-102 parts of a high glass transition temperature acrylic resin, 0.1-0.5 parts of a second photoinitiator, and 0.01-0.5 parts of a curing agent; the low glass transition temperature acrylic resin has a glass transition temperature (Tg) of -40 to 0°C; and the high glass transition temperature acrylic resin has a glass transition temperature of 0 to 32°C.

[0009] In this invention, the jelly adhesive adopts a three-layer composite system. The first pressure-sensitive adhesive layer is used to bond nail decorations or wearable device substrates; the middle layer provides structural rigidity support; and the second pressure-sensitive adhesive layer is used to bond human nails or skin surfaces. The first and second pressure-sensitive adhesive layers are low-Tg adhesive layers, which is beneficial for achieving high initial tack, curved surface fit, and high reliability. The middle layer is a high-Tg adhesive layer, forming a rigid skeleton and improving shear strength. The synergistic effect of the three layers enables the jelly adhesive to have excellent bonding performance, high shear strength, low odor, and is not easily displaced with a low residue rate.

[0010] In this invention, 90 to 102 parts of low glass transition temperature acrylic resin can be, for example, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, etc.

[0011] In this invention, 0.1 to 0.5 parts of the first photoinitiator can be, for example, 0.12 parts, 0.15 parts, 0.18 parts, 0.2 parts, 0.22 parts, 0.25 parts, 0.28 parts, 0.3 parts, 0.32 parts, 0.35 parts, 0.38 parts, 0.4 parts, 0.42 parts, 0.45 parts, 0.48 parts, etc.

[0012] In this invention, 90 to 102 parts of high glass transition temperature acrylic resin can be, for example, 91 parts, 92 parts, 93 parts, 94 parts, 95 parts, 96 parts, 97 parts, 98 parts, 99 parts, 100 parts, 101 parts, etc.

[0013] In this invention, 0.1 to 0.5 parts of the second photoinitiator can be, for example, 0.12 parts, 0.15 parts, 0.18 parts, 0.2 parts, 0.22 parts, 0.25 parts, 0.28 parts, 0.3 parts, 0.32 parts, 0.35 parts, 0.38 parts, 0.4 parts, 0.42 parts, 0.45 parts, 0.48 parts, etc.

[0014] In this invention, 0.01 to 0.5 parts of curing agent can be, for example, 0.02 parts, 0.04 parts, 0.06 parts, 0.08 parts, 0.1 parts, 0.12 parts, 0.15 parts, 0.18 parts, 0.2 parts, 0.22 parts, 0.25 parts, 0.28 parts, 0.3 parts, 0.32 parts, 0.35 parts, 0.38 parts, 0.4 parts, 0.42 parts, 0.45 parts, 0.48 parts, etc.

[0015] In this invention, the glass transition temperature of the low glass transition temperature acrylic resin is -40~0℃, for example, it can be -38℃, -36℃, -34℃, -32℃, -30℃, -28℃, -26℃, -25℃, -24℃, -22℃, -20℃, -18℃, -16℃, -15℃, -14℃, -12℃, -10℃, -8℃, -6℃, -4℃, -2℃, etc., preferably -30℃~-10℃, more preferably -20℃~-10℃.

[0016] In this invention, the glass transition temperature of the high glass transition temperature acrylic resin is 0~32℃, for example, it can be 2℃, 4℃, 6℃, 8℃, 10℃, 12℃, 14℃, 16℃, 18℃, 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, etc., and more preferably 10~30℃.

[0017] In this invention, the low glass transition temperature acrylic resin contains photocurable unsaturated double bonds, which can ensure sufficient fluidity of the adhesive layer before UV curing, better wetting of the nail, and sufficient strength after UV curing, thus improving the stability of the adhesive layer.

[0018] Preferably, the weight-average molecular weight of the low glass transition temperature acrylic resin is 300,000 to 800,000 Da, for example, it can be 320,000 Da, 350,000 Da, 380,000 Da, 400,000 Da, 420,000 Da, 450,000 Da, 480,000 Da, 500,000 Da, 520,000 Da, 550,000 Da, 580,000 Da, 600,000 Da, 620,000 Da, 650,000 Da, 680,000 Da, 700,000 Da, 720,000 Da, 750,000 Da, 780,000 Da, etc.; more preferably, it is 300,000 to 500,000 Da.

[0019] In this invention, if the weight-average molecular weight of the low glass transition temperature acrylic resin is too low, it will cause glue overflow during die cutting; if it is too high, it will reduce the initial adhesion of the adhesive layer and will not be conducive to bonding.

[0020] Preferably, the low glass transition temperature acrylic resin is prepared by solution polymerization.

[0021] In this invention, the product is prepared by solution polymerization, which results in a lower odor compared to bulk polymerization.

[0022] Preferably, by weight, the polymerizable monomers of the low glass transition temperature acrylic resin include 65-90 parts (e.g., 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 78, 80, 82, 84, 86, 88, etc.) of a first soft monomer, 5-30 parts (e.g., 6, 8, 10, 12, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, etc.) of a first hard monomer, and 1-8 parts (e.g., 1.2... The first functional monomer is expressed in parts of 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5, 7.8, etc., and the first crosslinking monomer is expressed in parts of 0.1 to 1.5 (e.g., 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, etc.).

[0023] In this invention, the first soft monomer includes, but is not limited to, n-butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, lauryl acrylate, isooctyl acrylate, etc.; the first hard monomer includes, but is not limited to, methyl methacrylate, isobornyl acrylate, methyl acrylate, etc.

[0024] In this invention, the first functional monomer contains a functional group and a carbon-carbon double bond; the functional group includes at least one of carboxyl, hydroxyl, amide, and epoxy groups.

[0025] In this invention, the first functional monomer includes, but is not limited to, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, acrylic acid, methacrylic acid, itaconic acid, acrylamide, N-hydroxymethylacrylamide, methacrylamide, glycidyl methacrylate, etc.

[0026] The first crosslinking monomer includes ethyl isocyanate (meth)acrylate.

[0027] In this invention, the first photoinitiator includes trimethylbenzoyl-diphenylphosphine oxide (photoinitiator TPO).

[0028] Preferably, the thickness of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is independently 50~200μm, for example, it can be 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, 135μm, 140μm, 145μm, 150μm, 155μm, 160μm, 165μm, 170μm, 175μm, 180μm, 185μm, 190μm, 195μm, etc., more preferably 75~150μm.

[0029] In this invention, if the first and second pressure-sensitive adhesive layers are too thin, the filling effect of the adhesive layers on the nail will decrease and the adhesion will be weak; if they are too thick, the overall strength of the jelly adhesive will decrease and the nail art will slip during use.

[0030] Preferably, the weight-average molecular weight of the high glass transition temperature acrylic resin is >800,000 Da, for example, it can be 820,000 Da, 850,000 Da, 880,000 Da, 900,000 Da, 920,000 Da, 950,000 Da, 980,000 Da, 1,000,000 Da, 1,050,000 Da, 1,100,000 Da, 1,150,000 Da, 1,200,000 Da, 1,250,000 Da, 1,300,000 Da, 1,350,000 Da, 1,400,000 Da, 1,450,000 Da, 1,500,000 Da, 1,550,000 Da, 1,600,000 Da, 1,650,000 Da, 1,700,000 Da, etc.

[0031] In this invention, the high glass transition temperature acrylic resin has a low weight-average molecular weight, resulting in insufficient cohesion in the adhesive layer and an inability to provide support.

[0032] Preferably, by weight, the polymerizable monomers of the high glass transition temperature acrylic resin include 30-40 parts (e.g., 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, etc.) of a second soft monomer, and 50-70 parts (e.g., 52, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, etc.). The second hard monomer consists of 68 parts and 1 to 8 parts (e.g., 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5, 7.8, etc.) of the second functional monomer.

[0033] In this invention, the second soft monomer includes, but is not limited to, n-butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, lauryl acrylate, isooctyl acrylate, etc.; the second hard monomer includes, but is not limited to, methyl methacrylate, isobornyl acrylate, methyl acrylate, etc.

[0034] In this invention, the second functional monomer contains a functional group and a carbon-carbon double bond; the functional group includes at least one of carboxyl, hydroxyl, amide, and epoxy groups; the second functional monomer includes, but is not limited to, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, acrylic acid, methacrylic acid, itaconic acid, acrylamide, N-hydroxymethylacrylamide, methacrylamide, glycidyl methacrylate, etc.

[0035] In this invention, the first soft monomer and the second soft monomer may be the same or different; the first hard monomer and the second hard monomer may be the same or different; the first functional monomer and the second functional monomer may be the same or different.

[0036] The curing agent includes at least one of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, glycerol propoxylate triacrylate, di-trimethylolpropane tetraacrylate, and pentaerythritol tetraacrylate.

[0037] In this invention, the second photoinitiator includes 1-hydroxycyclohexylphenyl ketone.

[0038] Preferably, the thickness of the intermediate layer is 100~300mm, for example, it can be 120 mm, 140 mm, 160 mm, 180 mm, 200 mm, 220 mm, 240 mm, 260 mm, 280 mm, etc., and more preferably 200~300mm.

[0039] In this invention, if the thickness of the intermediate layer is too thin, it will result in insufficient support; if it is too thick, it will increase the overall brittleness of the jelly adhesive, making it prone to cracking and breakage. Secondly, this invention provides a method for preparing the jelly tape according to the first aspect, the method comprising the following steps:

[0040] The first pressure-sensitive adhesive layer, the intermediate layer, and the second pressure-sensitive adhesive layer are stacked sequentially to obtain the jelly tape.

[0041] In this invention, the preparation methods of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer each independently include the following steps: mixing a low glass transition temperature acrylic resin with a photoinitiator to obtain a pressure-sensitive adhesive; coating the pressure-sensitive adhesive onto at least one surface of a substrate and drying it to obtain the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer.

[0042] In this invention, the preparation method of the low glass transition temperature acrylic resin includes: reacting a first soft monomer, a first hard monomer, and a first functional monomer with a solvent and an initiator at a formulation amount of 10-40% (e.g., 12%, 15%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, etc.) at 60-80°C (e.g., 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C, etc.) for 3-5 hours (e.g., 3.5 hours, 4 hours, 4.5 hours, etc.); then adding the remaining initiator and reacting at 68-88°C (e.g., 70°C, 72°C, 74°C, 76°C, 78°C, 80°C, 82°C, 84°C, 86°C, etc.) for 3-7 hours (e.g., 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, etc.). The reaction is carried out for 3-7 hours (e.g., 3.5 h, 6.5 h, etc.). Then the temperature is lowered to 40-60℃ (e.g., 42℃, 44℃, 46℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃, etc.), and the first crosslinking monomer is added. The reaction is continued for 3-7 hours (e.g., 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, etc.). The product is then discharged to obtain the low glass transition temperature acrylic resin. The solvent includes, but is not limited to, ethyl acetate. The initiator includes free radical initiators, including but not limited to azobisisobutyronitrile.

[0043] In this invention, the initiator amount of 10-40% refers to 10-40% of the total mass of the initiator.

[0044] In this invention, the preparation method of the intermediate layer includes the following steps: mixing a high glass transition temperature acrylic resin prepolymer with a curing agent and a photoinitiator to obtain an adhesive; coating the adhesive onto one surface of a substrate and curing it to obtain the intermediate layer.

[0045] In this invention, the preparation method of the high glass transition temperature acrylic resin prepolymer includes: mixing a second soft monomer, a second hard monomer, a second functional monomer and a photoinitiator, and irradiating with ultraviolet light in the presence of a protective atmosphere to obtain a prepolymer in which some monomers have polymerized, thereby obtaining the high glass transition temperature acrylic resin prepolymer.

[0046] In this invention, the curing is carried out under a protective atmosphere by UV curing lamp irradiation.

[0047] In this invention, the curing rate of the curing control intermediate layer is approximately 40%.

[0048] In this invention, the protective atmosphere involved includes, but is not limited to, nitrogen.

[0049] Thirdly, the present invention provides an application of the jelly tape according to the first aspect in nail art and wearable materials.

[0050] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0052] The jelly adhesive provided by this invention adopts a three-layer composite system, and the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer adopt low Tg adhesive layer, while the middle layer adopts high Tg adhesive layer. This makes the jelly adhesive have excellent bonding performance, high shear strength and low odor, and it is not easy to shift and has a low residual rate. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the structure of the jelly gel provided in Embodiment 1 of the present invention.

[0054] Wherein, 1-first pressure-sensitive adhesive layer; 2-intermediate layer; 3-second pressure-sensitive adhesive layer. Detailed Implementation

[0055] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0056] All materials used in this invention can be purchased commercially or prepared using conventional methods. Unless otherwise specified, the materials used in this invention are shown in Table 1.

[0057] Table 1

[0058]

[0059] Example 1

[0060] This embodiment provides a jelly gel, the structural schematic diagram of which is shown below. Figure 1 As shown, it includes a first pressure-sensitive adhesive layer 1, an intermediate layer 2, and a second pressure-sensitive adhesive layer 3 stacked in sequence.

[0061] By weight, both the first and second pressure-sensitive adhesive layers comprise 101.4 parts of low glass transition temperature acrylic resin and 0.15 parts of photoinitiator TPO. The low glass transition temperature acrylic resin has a Tg of -21°C and a Mw of 360,000. By weight, the low glass transition temperature acrylic resin comprises 65 parts of BA, 30 parts of MMA, 5 parts of HEA, and 1 part of AOI. The thickness of both the first and second pressure-sensitive adhesive layers is 100 μm.

[0062] By weight, the intermediate layer comprises 100.15 parts of high glass transition temperature acrylic resin, 0.05 parts of HDDA, and 0.15 parts of photoinitiator 184; the high glass transition temperature acrylic resin has a Tg of 30°C and a Mw of 1.6 million; by weight, the high glass transition temperature acrylic resin comprises 30 parts of BA, 65 parts of MMA, and 5 parts of HEA as polymer monomers; the thickness of the intermediate layer is 200 μm.

[0063] This embodiment provides a method for preparing jelly gel, specifically including the following steps:

[0064] 1. Preparation of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer

[0065] Mix 65 parts BA, 30 parts MMA, 5 parts HEA, 100 parts ethyl acetate, and 0.1 parts AIBN, and heat at 70°C for 4 hours. Then add 0.3 parts AIBN and heat at 78°C for 5 hours. Then cool down to 50°C, add 1 part AOI, heat for 5 hours, discharge, and add 0.15 parts photoinitiator TPO to obtain the prepared pressure-sensitive adhesive. Then coat it on the two surfaces of a 50 μm thick release film and dry to obtain a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer with a thickness of 100 μm.

[0066] 2. Preparation of the intermediate layer

[0067] 65 parts MMA, 30 parts BA, 5 parts HEA, and 0.15 parts photoinitiator 184 were mixed and irradiated with ultraviolet light for 15 minutes under a nitrogen atmosphere to obtain a prepolymer with partial monomer polymerization. 0.05 parts HDDA and 0.15 parts 184 were added to the prepolymer. The prepared adhesive was then coated onto a release film with a thickness of 200 μm and partially cured under a UV curing lamp in a nitrogen atmosphere, with the curing rate controlled at 40%, to obtain an intermediate layer.

[0068] 3. Preparation of gelatin:

[0069] According to the structure of the first pressure-sensitive adhesive, the intermediate layer, and the second pressure-sensitive adhesive layer (as shown in the figure) Figure 1 As shown, the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the adhesive surface of the intermediate layer are laminated together to obtain the jelly adhesive.

[0070] Examples 2-5 provide a jelly gel, which differs from Example 1 in the thickness of the first pressure-sensitive adhesive layer, the intermediate layer and the second pressure-sensitive adhesive layer, the composition of the polymer monomers (by weight), and Tg and Mw, as shown in Table 2. Other components, dosages and preparation methods are the same as in Example 1.

[0071] Table 2

[0072]

[0073] Example 6

[0074] This embodiment provides a jelly adhesive, which differs from Example 1 only in that the monomer types in the first pressure-sensitive adhesive layer, the intermediate layer, and the second pressure-sensitive adhesive layer are different. Specifically, BA is replaced with an equal mass of isooctyl acrylate 2-EHA, MMA is replaced with an equal mass of isobornyl acrylate IBOA, and HEA is replaced with an equal mass of 4-hydroxybutyl acrylate 4-HBA. Other components, dosages, and preparation methods are the same as in Example 1. The low glass transition temperature acrylic resins in the first and second pressure-sensitive adhesive layers have a Tg of -35°C and a Mw of 400,000 Da. The high glass transition temperature acrylic resins in the intermediate layer have a Tg of 20°C and a Mw of 1,560,000 Da.

[0075] Example 7

[0076] This embodiment provides a jelly adhesive, which differs from Embodiment 1 only in that the low glass transition temperature acrylic resin in the first and second pressure-sensitive adhesive layers has a Tg of -21°C and a Mw of 850,000 Da. The preparation method of the low glass transition temperature acrylic resin includes: mixing 65 parts BA, 30 parts MMA, 5 parts HEA, 80 parts ethyl acetate, and 0.05 parts AIBN, keeping the mixture at 65°C for 4 hours, then adding 0.3 parts AIBN, and keeping the mixture at 78°C for 5 hours; subsequently cooling to 50°C, adding 1 part AOI, keeping the mixture at 5 hours, and then discharging the material; other components, dosages, and preparation methods are the same as in Embodiment 1.

[0077] Example 8

[0078] This embodiment provides a jelly adhesive, which differs from Example 1 only in that the low glass transition temperature acrylic resin in the first and second pressure-sensitive adhesive layers has a Tg of -21°C and a Mw of 250,000 Da. The preparation method of the low glass transition temperature acrylic resin includes: mixing 65 parts BA, 30 parts MMA, 5 parts HEA, 150 parts ethyl acetate, and 0.15 parts AIBN, keeping the mixture at 70°C for 4 hours, then adding 0.3 parts AIBN, and keeping the mixture at 78°C for 5 hours; subsequently cooling to 50°C, adding 1 part AOI, keeping the mixture at 5 hours, and then discharging the material; other components, dosages, and preparation methods are the same as in Example 1.

[0079] Example 9

[0080] This embodiment provides a jelly gel, which differs from Example 1 only in that the high glass transition temperature acrylic resin in the intermediate layer has a Tg of 30°C and a Mw of 600,000 Da. The preparation method of the high glass transition temperature acrylic resin includes: mixing 65 parts MMA, 30 parts BA, 5 parts HEA, 0.15 parts photoinitiator 184, and 0.1 parts chain transfer agent n-dodecyl mercaptan (nDDm) under a nitrogen atmosphere and subjecting them to ultraviolet light irradiation for 15 minutes to obtain a prepolymer with partial monomer polymerization. Other components, dosages, and preparation methods are the same as in Example 1.

[0081] Example 10

[0082] This embodiment provides a jelly adhesive, which differs from Example 1 only in that the thickness of the intermediate layer is 50 μm, and the thickness of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are both 175 μm; the other components, dosages, and preparation methods are the same as in Example 1.

[0083] Comparative Example 1

[0084] This comparative example provides a jelly adhesive with a single-layer structure. The specific preparation method includes the following steps: 30 parts MMA, 65 parts BA, 5 parts HEA, and 0.15 parts photoinitiator 184 are mixed under a nitrogen atmosphere and subjected to ultraviolet light radiation to obtain a prepolymer of partially polymerized monomers; 0.05 parts HDDA and 0.15 parts 184 are added to the prepolymer; the prepared adhesive is then coated onto a release film with a thickness of 400 μm and partially cured under a UV curing lamp in a nitrogen atmosphere, controlling the curing rate at 40%, to obtain the jelly adhesive; the Tg of the acrylic resin is -21℃.

[0085] Comparative Example 2

[0086] This comparative example provides a jelly adhesive with a single-layer structure. The specific preparation method includes the following steps: 65 parts MMA, 30 parts BA, 5 parts HEA, and 0.15 parts photoinitiator 184 are mixed under a nitrogen atmosphere and subjected to ultraviolet light radiation to obtain a prepolymer of partially polymerized monomers; 0.05 parts HDDA and 0.15 parts 184 are added to the prepolymer; the prepared adhesive is then coated onto a release film with a thickness of 400 μm and partially cured under a UV curing lamp in a nitrogen atmosphere, controlling the curing rate at 40%, to obtain the jelly adhesive; the Tg of the acrylic resin is 30℃.

[0087] Comparative Example 3

[0088] This comparative example provides a jelly adhesive, which differs from Example 1 in that the low glass transition temperature acrylic resin in the first and second pressure-sensitive adhesive layers has a Tg of -45°C and a Mw of 400,000 Da. The preparation method of the low glass transition temperature acrylic resin is as follows: 85 parts of BA, 10 parts of MMA, 5 parts of HEA, 100 parts of ethyl acetate, and 0.1 parts of AIBN are mixed and kept at 70°C for 4 hours. Then, 0.3 parts of AIBN are added and kept at 78°C for 5 hours. Subsequently, the temperature is lowered to 50°C, 1 part of AOI is added, and the mixture is kept at 78°C for 5 hours before being discharged. Other components, dosages, and preparation methods are the same as in Example 1.

[0089] Comparative Example 4

[0090] This comparative example provides a jelly gel, which differs from Example 1 in that the high glass transition temperature acrylic resin in the intermediate layer has a glass transition temperature of 40°C and a Mw of 1.5 million Da; the preparation method of the high glass transition temperature acrylic resin is as follows: 75 parts MMA, 20 parts BA, 5 parts HEA, and 0.15 parts photoinitiator 184 are subjected to ultraviolet light irradiation for 15 minutes under a nitrogen atmosphere to obtain a prepolymer of partially monomerized polymers; other components, dosages, and preparation methods are the same as in Example 1.

[0091] Performance testing

[0092] (1) Peel force: 180° peel. The jelly adhesive was applied to the test plate and rolled back and forth three times with a 2kg standard roller. After irradiation with a nail lamp (3W power) for 1 minute and standing for 20 minutes, it was peeled at a 180-degree angle and a constant speed (300mm / min). The average peel force was recorded (unit: gf / 25mm). Reference standard: ASTM D3330.

[0093] (2) Holding force: Apply the jelly adhesive to a standard test plate, irradiate it with a nail lamp (3W) for 1 minute, suspend a 1kg weight, and record the amount of slippage (mm) of the tape after 24 hours. Reference standard: ASTM D3654.

[0094] (3) Shear strength: Two standard aluminum specimens were bonded together with a certain overlap using gel adhesive and left to stand for 20 minutes.

[0095] On a universal testing machine, apply a tensile test at a constant speed (e.g., 25 mm / min) until the bond fails. Record the maximum breaking force and calculate the strength per unit area (MPa). Reference standard: ASTM D1002

[0096] (4) Odor: Place the sample in a specified container (glass bottle) and heat at 70°C for 2 hours. Trained odor assessors (in groups of 5) evaluate the released odor at room temperature.

[0097] Rating criteria: Six-level strength method

[0098] Grade 1: Odorless.

[0099] Level 2: Has a slight odor, but the species cannot be identified.

[0100] Level 3: There is a noticeable but unpleasant odor.

[0101] Level 4: Has a noticeable and unpleasant odor.

[0102] Level 5: Has a strong, unpleasant odor.

[0103] Level 6: An unbearably strong odor.

[0104] Reference standard: VDA 270.

[0105] (5) Wearing rate test: 20 gel samples were selected for each example and comparative example. The gel was attached to the standard test plate and irradiated with a nail lamp (3W) for 1 minute. The peeling situation was observed after 7 days. If there was no peeling, the wearing rate was 100%. If 10 pieces were peeled off, the rate was 50%, and so on.

[0106] The specific test results are shown in Table 3.

[0107] Table 3

[0108]

[0109] As shown in Table 3, the jelly adhesive provided by the present invention adopts a three-layer composite system, and the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer adopt low Tg adhesive layers, while the middle layer adopts a high Tg adhesive layer. This allows the jelly adhesive to achieve high bonding reliability, high tear strength, low residual adhesive rate, and low odor. The peel force of the jelly adhesive is ≥2500gf / 25mm, the holding force is ≤2.1mm, the shear strength is ≥0.8MPa, and it has low odor and high wearing rate.

[0110] As can be seen from Comparative Examples 1 and 2, compared with a single-layer structure, the jelly adhesive provided by the present invention can take into account high bonding reliability, high tear strength, low residual adhesive rate and low odor.

[0111] As can be seen from Comparative Examples 3 and 4, the glass transition temperatures of the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the intermediate layer are not within a specific range, and at least one of the following properties of the jelly adhesive—peel force, holding force, shear strength, odor, and wearing rate—deteriorates.

[0112] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A jelly gel, characterized in that, The jelly adhesive includes a first pressure-sensitive adhesive layer, an intermediate layer, and a second pressure-sensitive adhesive layer arranged sequentially. By weight, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer each independently comprise 90-102 parts of low glass transition temperature acrylic resin and 0.1-0.5 parts of first photoinitiator; By weight, the intermediate layer comprises 90-102 parts of high glass transition temperature acrylic resin, 0.1-0.5 parts of second photoinitiator, and 0.01-0.5 parts of curing agent; The glass transition temperature of the low glass transition temperature acrylic resin is -40~0℃; The glass transition temperature of the high glass transition temperature acrylic resin is 0~32℃.

2. The jelly gel according to claim 1, characterized in that, The low glass transition temperature acrylic resin has a weight-average molecular weight of 300,000 to 800,000 Da.

3. The jelly gel according to claim 1, characterized in that, The low glass transition temperature acrylic resin was prepared by solution polymerization.

4. The jelly gel according to claim 1, characterized in that, By weight, the polymerizable monomers of the low glass transition temperature acrylic resin include 65-90 parts of a first soft monomer, 5-30 parts of a first hard monomer, 1-8 parts of a first functional monomer, and 0.1-1.5 parts of a first crosslinking monomer; The first crosslinking monomer includes ethyl isocyanate (meth)acrylate.

5. The jelly gel according to claim 1, characterized in that, The thickness of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are each independently 50~200μm.

6. The jelly gel according to claim 1, characterized in that, The high glass transition temperature acrylic resin has a weight-average molecular weight > 800,000 Da.

7. The jelly gel according to claim 1, characterized in that, By weight, the polymerizable monomers of the high glass transition temperature acrylic resin include 30-40 parts of a second soft monomer, 50-70 parts of a second hard monomer and 1-8 parts of a second functional monomer. The curing agent includes at least one of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, glycerol propoxylate triacrylate, di-trimethylolpropane tetraacrylate, and pentaerythritol tetraacrylate.

8. The jelly gel according to claim 1, characterized in that, The thickness of the intermediate layer is 100~300mm.

9. A method for preparing jelly gel according to any one of claims 1 to 8, characterized in that, The preparation method includes the following steps: The first pressure-sensitive adhesive layer, the intermediate layer, and the second pressure-sensitive adhesive layer are stacked sequentially to obtain the jelly adhesive; The preparation methods of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer each independently include the following steps: mixing a low glass transition temperature acrylic resin with a photoinitiator to obtain a pressure-sensitive adhesive; coating the pressure-sensitive adhesive onto at least one surface of a substrate and drying it to obtain the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer; The preparation method of the intermediate layer includes the following steps: mixing a high glass transition temperature acrylic resin prepolymer with a curing agent and a photoinitiator to obtain an adhesive; coating the adhesive onto one surface of a substrate and curing it to obtain the intermediate layer.

10. The application of the jelly gel according to any one of claims 1 to 8 in nail art and wearable materials.

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