Halogen-free gold stamping adhesive for skin feeling ink substrate and preparation method thereof
By using styrene-butadiene-styrene block copolymer, amorphous poly-α-olefin and silicone-modified acrylic resin in halogen-free hot stamping adhesive, the problem of poor adhesion of the adhesive on low surface energy substrates is solved, achieving a hot stamping effect with high adhesion and environmental friendliness, suitable for skin-feel ink substrates of high-end products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG BANGGU CHEM TECH
- Filing Date
- 2026-06-08
- Publication Date
- 2026-07-28
AI Technical Summary
Existing technologies struggle to achieve strong adhesion and meet environmental requirements for halogen-free hot stamping adhesives on low surface energy substrates (such as skin-feel ink substrates). Traditional adhesives have poor adhesion and contain environmentally unfriendly halogen components.
Using styrene-butadiene-styrene block copolymer, amorphous poly-α-olefin, silicone-modified acrylic resin, aldehyde-ketone resin, C9 petroleum resin, and fumed silica, a synergistic halogen-free hot stamping adhesive is formed through specific synthesis and dispersion processes. The low polarity and microphase separation structure of the styrene-butadiene-styrene block copolymer, combined with the flowability of amorphous poly-α-olefin and the wettability of the siloxane segments of silicone-modified acrylic resin, enhance adhesion and hot stamping effect.
It achieves excellent adhesion and hot stamping effect on low surface energy substrates, with good pattern integrity, meets environmental protection requirements, and satisfies the green production needs of high-end products.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of adhesive technology, specifically relating to a halogen-free hot stamping adhesive for skin-feel ink substrates and its preparation method. Background Technology
[0002] Skin-feel ink substrates are a special type of substrate that imparts a delicate, smooth feel to printed packaging, similar to skin, and are widely used in high-end cosmetics packaging, digital packaging, and other fields. To achieve this skin-feel effect, feel-enhancing agents (such as silicone elastomers) are typically added, resulting in a lower surface energy. This makes it difficult for traditional hot stamping adhesives to adhere, or results in extremely poor adhesion, easily leading to incomplete printing and blurry lines. Furthermore, some chlorinated polymer solutions may contain medium-chain chlorinated paraffins (MCCPs) in their chlorinated polypropylene formulations, which are environmentally persistent, bioaccumulative, and toxic; and may release certain chlorinated hydrocarbon pollutants during production. In fluorinated modification solutions, some perfluorinated compounds (such as C9-C14 perfluorocarboxylic acids) are also subject to regulatory restrictions. In addition, the generally high price of perfluoroalkyl acrylate monomers limits their large-scale application.
[0003] Therefore, there is an urgent need for a halogen-free hot stamping adhesive that can achieve a strong bond with low surface energy substrates (such as skin-feel substrates) while also meeting environmental protection requirements. Summary of the Invention
[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a halogen-free hot stamping adhesive for skin-feel ink substrates and its preparation method.
[0005] The first aspect of this invention is to provide a halogen-free hot stamping adhesive for skin-feel ink substrates, comprising, by weight, the following components: 30-50 parts of styrene-butadiene-styrene block copolymer, 10-30 parts of amorphous poly-α-olefin, 10-20 parts of silicone-modified acrylic resin, 20-30 parts of aldehyde-ketone resin, 20-30 parts of C9 petroleum resin, 1-3 parts of aluminum acetylacetonate, 10-15 parts of fumed silica, and 50-100 parts of solvent. The amorphous poly-α-olefin is prepared by the following steps: (1) Under the protection of an inert gas, a reaction medium is added, followed by the sequential addition of 1-butene and 1-hexene to carry out the reaction; (2) Triethylaluminum and supported Ziegler-Natta catalyst were added sequentially to the reaction system of step (1) and stirred. Propylene was then introduced, followed by the introduction of a chain transfer agent to carry out the reaction and obtain a polymer solution. (3) Add a terminator to the polymer solution, wash and dry to constant weight to obtain amorphous poly-α-olefin.
[0006] The supported Ziegler-Natta catalyst is TiCl4 / MgCl2.
[0007] In some embodiments, by weight, the reaction medium is 50-100 parts, 1-butene is 10-30 parts, 1-hexene is 5-10 parts, triethylaluminum is 1.5-2.5 parts, supported Ziegler-Natta catalyst is 0.5-1 parts, propylene is 50-70 parts, chain transfer agent is 0.05-0.15 parts, and terminator is 100-200 parts.
[0008] In some embodiments, the reaction medium is selected from hexane or heptane; the terminator is a 50% aqueous ethanol solution; and the chain transfer agent is hydrogen gas with a purity >99.999%.
[0009] In some embodiments, in step (1), the reaction temperature is 60-70℃; in step (2), the stirring time is 5-10 min, the reaction pressure is 0.5-0.8 MPa, the reaction temperature is 60-70℃, and the reaction time is 2-3 h; in step (3), the drying is carried out in a vacuum drying oven at 60-70℃.
[0010] In some embodiments, the solvent is selected from at least one of toluene and ethyl acetate.
[0011] A second aspect of this invention is to provide a method for preparing a halogen-free hot stamping adhesive for a skin-feel ink substrate, comprising the following steps: S1: Add the solvent to the stirred tank, and then add the styrene-butadiene-styrene block copolymer, amorphous poly-α-olefin, and organosilicon-modified acrylic resin in sequence and stir to disperse. S2: Add aldehyde-ketone resin, C9 petroleum resin and aluminum acetylacetonate to the dispersion system of S1, and stir to disperse; S3: Add fumed silica to the dispersion system of S1, stir and disperse, and filter to obtain halogen-free hot stamping adhesive for skin-feel ink substrate.
[0012] In some embodiments, in S1, the stirring speed is 800-1200 rpm, the dispersion temperature is 55-65℃, and the stirring time is 50-70 min.
[0013] In some embodiments, in S2, the stirring speed is 800-1200 rpm and the stirring time is 25-35 min; in S3, the stirring speed is 800-1200 rpm and the stirring time is 50-70 min.
[0014] In some embodiments, if solvent evaporation occurs during the stirring and dispersion process, ethyl acetate is added to replenish the original solvent volume.
[0015] In some implementations, the filter mesh size is 140-160 mesh.
[0016] Compared with the prior art, the present invention has the following technical effects: 1. In this synthetic reaction, propylene was chosen as the main monomer to provide the polymer backbone structure. 1-Butene and 1-hexene were used as comonomers to effectively disrupt chain regularity, significantly reduce crystallinity, and achieve a low softening point and a highly fluid amorphous form. Regarding the catalyst, the supported Ziegler-Natta catalyst exhibits extremely high activity. By precisely controlling the insertion method of the comonomers, it can effectively disrupt the regularity of the molecular chain and efficiently produce atactic polymers. Triethylaluminum was chosen as the cocatalyst to efficiently alkylate TiCl4 on the main catalyst into active Ti-C bonds, forming active centers.
[0017] 2. In this adhesive formulation, styrene-butadiene-styrene block copolymer (SBS) is selected as the main resin. Its low polarity establishes good wetting between the adhesive and the substrate. Furthermore, the thermodynamic incompatibility of its styrene-butadiene-styrene block structure creates a microphase separation structure. The styrene segments act as hard segments, forming physical cross-linking points, while the butadiene segments provide flowability, constituting a strong and tough elastomer structure. This allows it to resist external stress through minor deformation, resulting in high cohesive strength. Simultaneously, amorphous poly-α-olefin is added, further improving material flowability and strengthening interfacial bonding. As an adhesion promoter, it replaces traditional chlorinated polypropylene, addressing environmental requirements from material synthesis to resin application. The added silicone-modified acrylic resin has a weakly polar siloxane segment, which aids in the spreading and wetting of the adhesive on skin-feel substrates, working synergistically with the amorphous poly-α-olefin. Furthermore, the addition of the siloxane segment effectively improves the compatibility of the acrylate segment with styrene-butadiene-styrene block copolymer (SBS) and amorphous poly-α-olefins; while the acrylate segment provides good adhesion to the aluminum plating layer (i.e., the bonding strength between the adhesive layer and the aluminum plating layer). The addition of C9 petroleum resin further lowers the softening point of the material and enhances its fluidity. The addition of aldehyde-ketone resin brings highly polar groups, whose strong hydrogen bonding forces strongly promote the adhesion of the substrate. The addition of fumed silica increases the viscosity of the system and improves the stability of the colloidal solution; in addition, during hot stamping, fumed silica can effectively construct venting channels, improve the venting performance of the adhesive, and thus ensure the flatness and integrity of the hot stamping pattern. Finally, this invention also creatively incorporates aluminum acetylacetonate, whose polar surface can form reversible physical hydrogen bonds / dipole clusters with carbonyl groups, benzene rings, and other groups in the system through intermolecular forces. During hot stamping, these physical clusters temporarily dissociate, causing the melt viscosity of the system to decrease, thereby significantly improving the flow and spreadability of the adhesive layer and ensuring the integrity of the pattern. After cooling, the hydrogen bond / dipole clusters re-aggregate rapidly. This process increases the surface energy of the adhesive layer, effectively enhancing the wetting and physical anchoring of low surface energy substrates such as skin-feel inks.
[0018] 3. The halogen-free hot stamping adhesive provided by this invention exhibits excellent adhesion to low surface energy substrates (such as skin-feel ink substrates) through the synergistic effect of styrene-butadiene-styrene block copolymer (SBS), amorphous poly-α-olefin, and silicone-modified acrylic resin. It also provides excellent hot stamping results with a moderate stamping temperature and good pattern integrity on skin-feel ink substrates. The addition of amorphous poly-α-olefin (softening point 80℃) and silicone-modified acrylic resin results in high flatness and gloss, clear lines, and no gold fly. Furthermore, this invention uses self-synthesized amorphous poly-α-olefin instead of traditional chlorinated polypropylene, complying with domestic and international environmental regulations, meeting the green production requirements of high-end products, and solving the industry pain points of poor adhesion of halogen-free adhesives and the environmental unfriendliness of adding halogen adhesives. Detailed Implementation
[0019] The present invention will now be described in further detail with reference to specific embodiments.
[0020] Example 1 A halogen-free hot stamping adhesive for skin-feel ink substrates comprises, by weight, the following components: 40 parts of styrene-butadiene-styrene block copolymer, 20 parts of amorphous poly-α-olefin, 10 parts of silicone-modified acrylic resin, 20 parts of aldehyde-ketone resin, 20 parts of C9 petroleum resin, 2 parts of aluminum acetylacetonate, 10 parts of fumed silica, and 60 parts of toluene. The amorphous poly-α-olefin is prepared by the following steps: (1) Under the protection of an inert gas, 80 parts by weight of hexane were added, followed by 20 parts by weight of 1-butene and 10 parts by weight of 1-hexene, and the reaction was carried out at 65°C. (2) Add 2.5 parts by weight of triethylaluminum and 1 part by weight of supported Ziegler-Natta catalyst to the reaction system of step (1) and stir for 8 min. Then introduce 60 parts by weight of propylene and then introduce 0.1 parts by weight of hydrogen with a purity >99.999%. React at 0.7 MPa and 65 °C for 2.5 h to obtain a polymer solution. (3) Add 180 parts by weight of 50% ethanol aqueous solution to the polymer solution, wash and dry in a vacuum drying oven at 65°C until constant weight to obtain amorphous poly-α-olefin.
[0021] The halogen-free hot stamping adhesive for skin-feel ink substrates described above is prepared by the following steps: S1: Add toluene to a stirred tank, and then add styrene-butadiene-styrene block copolymer (source: Sinopec YH-791), amorphous poly-α-olefin, and organosilicon-modified acrylic resin (source: IGM Resins Omnivad280) in sequence. Stir at 1000 rpm and 60°C for 60 min to disperse evenly. S2: Add aldehyde-ketone resin (source: JT-N100 from Puyang Jiteng Chemical Co., Ltd.), C9 petroleum resin and aluminum acetylacetonate (source: HX-Al(acac)3 from Shandong Hongxing) to the dispersion system of S1, and stir at 1000 rpm for 30 minutes to disperse evenly. S3: Add fumed silica (source: Wacker's H2O) to the dispersion system of S1, stir at 1000 rpm for 65 min to disperse evenly. If solvent evaporation occurs during the stirring and dispersion process, add ethyl acetate to replenish the original solvent volume. Filter through a 150 mesh screen to obtain halogen-free hot stamping adhesive for skin-feel ink substrates.
[0022] Example 2 A halogen-free hot stamping adhesive for skin-feel ink substrates comprises, by weight, the following components: 50 parts of styrene-butadiene-styrene block copolymer, 30 parts of amorphous poly-α-olefin, 20 parts of silicone-modified acrylic resin, 30 parts of aldehyde-ketone resin, 30 parts of C9 petroleum resin, 3 parts of aluminum acetylacetonate, 15 parts of fumed silica, and 100 parts of ethyl acetate. The amorphous poly-α-olefin is prepared by the following steps: (1) Under the protection of an inert gas, add 100 parts by weight of heptane, followed by 30 parts by weight of 1-butene and 10 parts by weight of 1-hexene, and react at 70°C. (2) Add 2.5 parts by weight of triethylaluminum and 1 part by weight of supported Ziegler-Natta catalyst to the reaction system of step (1) and stir for 10 min. Then introduce 70 parts by weight of propylene and then introduce 0.15 parts by weight of hydrogen with a purity >99.999%. React at 0.8 MPa and 70 °C for 2 h to obtain a polymer solution. (3) Add 200 parts by weight of 50% ethanol aqueous solution to the polymer solution, wash and dry in a vacuum drying oven at 70°C until constant weight to obtain amorphous poly-α-olefin.
[0023] The halogen-free hot stamping adhesive for skin-feel ink substrates described above is prepared by the following steps: S1: Add ethyl acetate to a stirred tank, and then add styrene-butadiene-styrene block copolymer (source: PetroChina's T161B), amorphous poly-α-olefin, and organosilicon-modified acrylic resin (source: Sinochem's WE-D1200) in sequence. Stir at 1200 rpm and 55°C for 70 min to disperse evenly. S2: Add aldehyde and ketone resin (source: Ketonic 800 from DIMACOLOR), C9 petroleum resin and aluminum acetylacetonate (source: LT-Al(acac)3 from Jiangsu Litian) to the dispersion system of S1, and stir at 1200 rpm for 25 min to disperse evenly. S3: Add fumed silica to the dispersion system of S1 (Source: Evonik Aerosil) ® R972), stir at 1200 rpm for 50 minutes to disperse evenly. If solvent evaporation occurs during the stirring and dispersion process, add ethyl acetate to replenish the original solvent volume. Filter through a 160-mesh filter to obtain halogen-free hot stamping adhesive for skin-feel ink substrates.
[0024] Example 3 A halogen-free hot stamping adhesive for skin-feel ink substrates comprises, by weight, the following components: 30 parts of styrene-butadiene-styrene block copolymer, 10 parts of amorphous poly-α-olefin, 10 parts of silicone-modified acrylic resin, 20 parts of aldehyde-ketone resin, 20 parts of C9 petroleum resin, 1 part of aluminum acetylacetonate, 10 parts of fumed silica, and 50 parts of solvent. The amorphous poly-α-olefin is prepared by the following steps: (1) Under the protection of an inert gas, add 50 parts by weight of hexane, followed by 10 parts by weight of 1-butene and 5 parts by weight of 1-hexene and react at 60°C. (2) Add 1.5 parts by weight of triethylaluminum and 0.5 parts by weight of supported Ziegler-Natta catalyst to the reaction system of step (1) and stir for 5 min. Then introduce 50 parts by weight of propylene and then introduce 0.05 parts by weight of hydrogen with a purity >99.999%. React at 0.5 MPa and 60 °C for 3 h to obtain a polymer solution. (3) Add 100 parts by weight of 50% ethanol aqueous solution to the polymer solution, wash and dry in a vacuum drying oven at 60°C until constant weight to obtain amorphous poly-α-olefin.
[0025] The halogen-free hot stamping adhesive for skin-feel ink substrates described above is prepared by the following steps: S1: Add 20 parts by weight of toluene and 30 parts by weight of ethyl acetate to a stirred tank, and then add styrene-butadiene-styrene block copolymer, amorphous poly-α-olefin and organosilicon modified acrylic resin in sequence. Stir at 800 rpm and 55°C for 70 min to disperse evenly. S2: Add aldehyde-ketone resin, C9 petroleum resin and aluminum acetylacetonate to the dispersion system of S1, and stir at 800 rpm for 35 min to disperse evenly. S3: Add fumed silica to the dispersion system of S1, stir at 800 rpm for 70 minutes to disperse evenly. If solvent evaporation occurs during the stirring and dispersion process, add ethyl acetate to replenish the original solvent volume. Filter through a 140-mesh filter to obtain halogen-free hot stamping adhesive for skin-feel ink substrates.
[0026] Comparative Example 1 It is basically the same as Example 1, except that: no amorphous poly-α-olefin is added.
[0027] Comparative Example 2 It is basically the same as Example 1, except that no aldehyde or ketone resin is added.
[0028] Comparative Example 3 It is basically the same as Example 1, except that aluminum acetylacetonate is not added.
[0029] Comparative Example 4 A commercially available chlorine-containing general-purpose hot stamping adhesive, whose main components are vinyl chloride-vinyl acetate copolymer and chlorinated polypropylene.
[0030] Comparative Example 5 A commercially available halogen-free universal hot stamping adhesive has thermoplastic acrylic resin as its main component.
[0031] The performance of the hot stamping adhesives of Examples 1-3 and Comparative Examples 1-5 was tested, and the test results are shown in Table 1.
[0032] Table 1
[0033] As can be seen from Table 1, the halogen-free hot stamping adhesives prepared in Examples 1-3 have excellent adhesion, hot stamping effect, gloss and meet the halogen-free environmental protection requirements. However, the adhesion of the adhesives in Comparative Examples 1 and 2 is worse due to the lack of amorphous poly-α-olefin and aldehyde-ketone resin. The adhesion and gloss of Comparative Example 3 are reduced due to the lack of aluminum acetylacetonate. Comparative Examples 4 and 5 are commercially available products, and their hot stamping performance on skin-feel paper substrates is not as good as that of Examples 1-3.
[0034] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.
Claims
1. A halogen-free hot stamping adhesive for skin-feel ink substrates, characterized in that, By weight, it includes the following components: 30-50 parts of styrene-butadiene-styrene block copolymer, 10-30 parts of amorphous poly-α-olefin, 10-20 parts of silicone-modified acrylic resin, 20-30 parts of aldehyde-ketone resin, 20-30 parts of C9 petroleum resin, 1-3 parts of aluminum acetylacetonate, 10-15 parts of fumed silica, and 50-100 parts of solvent. The amorphous poly-α-olefin is prepared by the following steps: (1) Under the protection of an inert gas, a reaction medium is added, followed by the sequential addition of 1-butene and 1-hexene to carry out the reaction; (2) Triethylaluminum and supported Ziegler-Natta catalyst were added sequentially to the reaction system of step (1) and stirred. Propylene was then introduced, followed by the introduction of a chain transfer agent to carry out the reaction and obtain a polymer solution. (3) Add a terminator to the polymer solution, wash and dry to constant weight to obtain the amorphous poly-α-olefin.
2. The halogen-free hot stamping adhesive for skin-feel ink substrates according to claim 1, characterized in that, By weight, the reaction medium is 50-100 parts, the 1-butene is 10-30 parts, the 1-hexene is 5-10 parts, the triethylaluminum is 1.5-2.5 parts, the supported Ziegler-Natta catalyst is 0.5-1 parts, the propylene is 50-70 parts, the chain transfer agent is 0.05-0.15 parts, and the terminator is 100-200 parts.
3. The halogen-free hot stamping adhesive for skin-feel ink substrates according to claim 2, characterized in that, The reaction medium is selected from either hexane or heptane; the terminator is a 50% aqueous solution of ethanol; and the chain transfer agent is hydrogen gas with a purity >99.999%.
4. The halogen-free hot stamping adhesive for skin-feel ink substrates according to claim 1, characterized in that, In step (1), the reaction temperature is 60-70℃; in step (2), the stirring time is 5-10 min, the reaction pressure is 0.5-0.8 MPa, the reaction temperature is 60-70℃, and the reaction time is 2-3 h; in step (3), the drying is carried out in a vacuum drying oven at 60-70℃.
5. The halogen-free hot stamping adhesive for skin-feel ink substrates according to claim 1, characterized in that, The solvent is selected from at least one of toluene and ethyl acetate.
6. A method for preparing a halogen-free hot stamping adhesive for a skin-feel ink substrate as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Add the solvent to the stirred tank, and then add the styrene-butadiene-styrene block copolymer, amorphous poly-α-olefin, and organosilicon-modified acrylic resin in sequence and stir to disperse. S2: Add aldehyde-ketone resin, C9 petroleum resin and aluminum acetylacetonate to the dispersion system of S1, and stir to disperse; S3: Add fumed silica to the dispersion system of S1, stir and disperse, and filter to obtain the halogen-free hot stamping adhesive for skin-feel ink substrate.
7. The method for preparing halogen-free hot stamping adhesive for skin-feel ink substrates according to claim 6, characterized in that, In step S1, the stirring speed is 800-1200 rpm, the dispersion temperature is 55-65℃, and the stirring time is 50-70 min.
8. The method for preparing halogen-free hot stamping adhesive for skin-feel ink substrates according to claim 6, characterized in that, In step S2, the stirring speed is 800-1200 rpm and the stirring time is 25-35 min; in step S3, the stirring speed is 800-1200 rpm and the stirring time is 50-70 min.
9. The method for preparing halogen-free hot stamping adhesive for skin-feel ink substrates according to claim 6, characterized in that, If solvent evaporates during the stirring and dispersion process, add ethyl acetate to replenish the original solvent volume.
10. The method for preparing halogen-free hot stamping adhesive for skin-feel ink substrates according to claim 6, characterized in that, The filter screen has a mesh size of 140-160.