Hot-melt pressure-sensitive adhesive with high removable performance and preparation method of hot-melt pressure-sensitive adhesive

Abstract

The invention relates to the technical field of hot-melt pressure-sensitive adhesives, and discloses a hot-melt pressure-sensitive adhesive with high removable performance and a preparation method thereof, the hot-melt pressure-sensitive adhesive comprises the following raw materials: naphthenic oil, phenyl siloxane rubber, a hydrogenated styrene block copolymer and tackifying resin; the phenyl silicone rubber is a surface energy improver, and the tackifying resin is hydrogenated petroleum resin. By adding the phenyl siloxane rubber, the surface energy of the hot-melt pressure-sensitive adhesive can be reduced, so that the adhesive force between an existing adhesive layer and the surface of an adhered object is reduced, and the removable performance of the hot-melt pressure-sensitive adhesive on the surface of the adhered object is improved. According to the preparation method of the hot-melt pressure-sensitive adhesive, provided by the invention, the manufacturing cost of the hot-melt pressure-sensitive adhesive with high removable performance can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of hot melt pressure sensitive adhesives, and in particular to a hot melt pressure sensitive adhesive with high removability and a preparation method thereof. Background Art

[0002] Labels are necessary identifiers for products in the prior art.

[0003] After the labels made of hot-melt pressure-sensitive adhesive in the prior art are removed, glue stains that are difficult to clean are often left on the surface of the adhered object, which not only affects the appearance of the product, but may also cause the subsequent added labels to be poorly adhered, thereby affecting the sales of the product. Summary of the invention

[0004] In view of the above problems, the first object of the present invention is to provide a hot melt pressure sensitive adhesive with high removability to solve the problem of residual adhesive stains when removing the hot melt pressure sensitive adhesive in the prior art.

[0005] The second object of the present invention is to provide a method for preparing a hot melt pressure sensitive adhesive to reduce the manufacturing cost of the hot melt pressure sensitive adhesive with high removability.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A hot melt pressure-sensitive adhesive with high removability, the raw materials of the hot melt pressure-sensitive adhesive comprising:

[0008] Naphthenic oil, phenyl silicone rubber, hydrogenated styrene block copolymer and tackifying resin;

[0009] The phenyl silicone rubber is a surface energy improver, and the tackifying resin is a hydrogenated petroleum resin.

[0010] Specifically, calculated by mass percentage, the raw materials of the hot melt pressure sensitive adhesive include:

[0011] Naphthenic oil 12-18%, phenyl silicone rubber 12-18%, hydrogenated styrene block copolymer 28-35%, tackifying resin 35-55% and antioxidant 0.2-0.8%.

[0012] Preferably, the pour point of the naphthenic oil is -25 to -10°C; the flash point is 200-240°C; the density at 20°C is 850-950 kg / m 3 ; The viscosity constant is 0.820-0.850; the refractive index at 20°C is 1.45-1.52; the aniline point is 90-110°C; the CN in the carbon type analysis is greater than 40%;

[0013] The phenyl silicone rubber has a phenyl content of 2.0-30.0 mol% and a vinyl content of 0.10-0.35 wt%.

[0014] Preferably, the hydrogenated styrene block copolymer SEBS has a styrene content of 25-35%, a diblock content of <1wt%, a toluene solution viscosity of 440cps, a Shore hardness of 65-80A / 10 seconds, a tensile strength of 15-35MPa, and an elongation at break of 250-800%.

[0015] Preferably, the SEPS has a styrene content of 20-40%; a diblock content of 100%; and a toluene solution viscosity of ≥50,000 cps.

[0016] Preferably, the softening point of the tackifying resin of the hydrogenated petroleum resin is 90-120°C; the number average molecular weight is 200-600 g / mol;

[0017] The antioxidant is selected from at least one of the antioxidant 1010 and the antioxidant 168 .

[0018] Furthermore, the present invention provides a method for preparing a hot melt pressure-sensitive adhesive, which is used to prepare the hot melt pressure-sensitive adhesive with high removability, comprising the following steps:

[0019] S1) weighing naphthenic oil, phenyl silicone rubber, hydrogenated styrene block copolymer, tackifying resin and antioxidant respectively according to the formula ratio, then adding the antioxidant and naphthenic oil into a container, and continuously stirring until the materials are evenly mixed to obtain a mixed solution;

[0020] S2) adding phenyl silicone rubber and hydrogenated styrene block copolymer to the mixed solution in sequence, and continuously stirring until the materials are completely dissolved, to obtain a rubber solution;

[0021] S3) adding tackifying resin to the stirred rubber solution in portions, and continuing stirring until the tackifying resin is completely dissolved, thereby obtaining the hot melt pressure-sensitive adhesive with high removability.

[0022] Preferably, in steps S1) to S3), the stirring and mixing temperature of the materials is 140-150°C.

[0023] Preferably, in step S1), the stirring time after adding the material is 5-20 minutes;

[0024] In step S2) and step S3), the stirring time after adding the materials is 20-90 minutes.

[0025] Preferably, the viscosity of the prepared hot melt pressure sensitive adhesive with high removability is 5500-6000 cps.

[0026] The beneficial effect of the above technical solution of the present invention is: the hot-melt pressure-sensitive adhesive with high removability reduces the surface energy of the hot-melt pressure-sensitive adhesive by adding phenyl silicone rubber, thereby reducing the adhesion between the existing adhesive layer and the surface of the adherend, and improving the removability of the hot-melt pressure-sensitive adhesive on the surface of the adherend.

[0027] Furthermore, the preparation method of the hot melt pressure-sensitive adhesive proposed in the present invention has the advantages of simple process, simple production equipment and low manufacturing cost. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0029] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0030] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0031] A hot melt pressure-sensitive adhesive with high removability, the raw materials of the hot melt pressure-sensitive adhesive comprising:

[0032] Naphthenic oil, phenyl silicone rubber, hydrogenated styrene block copolymer and tackifying resin;

[0033] The phenyl silicone rubber is a surface energy improver, and the tackifying resin is a hydrogenated petroleum resin.

[0034] The present invention proposes a hot-melt pressure-sensitive adhesive with high removability. Phenyl silicone rubber is introduced into the hot-melt pressure-sensitive adhesive formula, which can effectively reduce the surface energy of the hot-melt pressure-sensitive adhesive, thereby better reducing the adhesion between the adhesive layer and the surface of the adherend, and improving the removability of the hot-melt pressure-sensitive adhesive on the surface of the adherend.

[0035] Specifically, calculated by mass percentage, the raw materials of the hot melt pressure sensitive adhesive include:

[0036] Naphthenic oil 12-18%, phenyl silicone rubber 12-18%, hydrogenated styrene block copolymer 28-35%, tackifying resin 35-55% and antioxidant 0.2-0.8%.

[0037] When the content of naphthenic oil is 12-18%, it can have a good softening and plasticizing effect, and will not make the hot melt pressure sensitive adhesive too soft and lose strength and cohesion. If the amount of naphthenic oil is too little, the flexibility of the hot melt pressure sensitive adhesive will be reduced, the processing performance will be poor, and the wettability to the surface of the adherend will also be weakened. If the amount of naphthenic oil is too much, it may cause the cohesive strength of the hot melt pressure sensitive adhesive to be reduced, and the hot melt pressure sensitive adhesive will become too soft, which may easily cause the label to sag or shift in actual application, and "drawing" phenomenon is also likely to occur during the peeling process.

[0038] If the amount of phenyl silicone rubber used is too much, the adhesion between the adhesive layer and the surface of the adherend will be too low, and in some application scenarios that require a certain degree of stickiness to ensure the stability of the adhesive, it is easy to accidentally fall off. In addition, due to the relatively high price of phenyl silicone rubber, excessive use will increase production costs. If the amount of phenyl silicone rubber used is too little, the removability of the hot melt pressure-sensitive adhesive is not good, and the adhesion between the adhesive layer and the adherend may be too high, and residual glue is likely to appear when removing the glue.

[0039] If the amount of hydrogenated styrene block copolymer is too much, too much elastic component will be produced, making the molecular chain of the adhesive relatively loose, the elasticity of the adhesive too large, and there will be a strong rebound force after pasting, so that the adhesive layer cannot fit the surface of the adherend well, and the effective contact area between the adhesive and the adherend is reduced, thus affecting the firmness of the pasting. If the amount of hydrogenated styrene block copolymer is too little, the elasticity and strength of the hot melt pressure sensitive adhesive are insufficient, and the adhesive layer is easy to break when vibrated or pulled, and the long-term pasting stability cannot be guaranteed. The weather resistance may also be affected, and the hot melt pressure sensitive adhesive is more likely to age or crack.

[0040] If the amount of tackifying resin is too much, on the one hand, during the processing, the glue will become too viscous, and higher temperature and pressure will be required for extrusion, which will increase energy consumption and easily clog the equipment. It is difficult to apply evenly during use, and uneven thickness is likely to occur. On the other hand, the flexibility and elasticity of the glue will be weakened, the glue layer will become brittle and hard, and the glue layer will easily crack when the adherend is deformed, affecting the durability of the adhesive. The initial viscosity is too high, making it inconvenient to adjust the position during adhesive bonding. If the amount of tackifying resin is too little, the problem of insufficient viscosity will occur, and it will easily fall off when sticking to heavy or smooth objects, and the stability of adhesive bonding will be affected during long-term use.

[0041] If the amount of antioxidant is too little, it will not be able to effectively prevent the hot melt pressure sensitive adhesive from oxidative aging during processing and use, and it is easy to appear yellowing, hardening and decreased viscosity aging phenomenon, shortening the service life of the hot melt pressure sensitive adhesive. If the amount of antioxidant is too much, it may affect the color and smell of the hot melt pressure sensitive adhesive, and increase production costs.

[0042] Preferably, the pour point of the naphthenic oil is -25 to -10°C; the flash point is 200-240°C; the density at 20°C is 850-950 kg / m 3 ; The viscosity constant is 0.820-0.850; the refractive index at 20°C is 1.45-1.52; the aniline point is 90-110°C; the CN in the carbon type analysis is greater than 40%;

[0043] The phenyl silicone rubber has a phenyl content of 2.0-30.0 mol% and a vinyl content of 0.10-0.35 wt%.

[0044] Introducing phenyl silicone rubber into the hot melt pressure-sensitive adhesive formula can effectively reduce the surface energy of the hot melt pressure-sensitive adhesive. At the same time, it can also improve thermal stability, reduce the glass transition temperature, and broaden the operating temperature range of the hot melt pressure-sensitive adhesive.

[0045] By adding phenyl silicone rubber, the glass transition temperature (Tg) of the hot melt pressure-sensitive adhesive can be effectively lowered, so that the hot melt pressure-sensitive adhesive can still maintain a certain flexibility and elasticity at lower temperatures without becoming brittle and hard. This ensures that the hot melt pressure-sensitive adhesive can adapt to the slight deformation of the adherend in a low temperature environment, maintain a good bonding effect, avoid problems such as bonding failure and material falling off caused by low temperature, and expand the scope of use and environmental adaptability of the hot melt pressure-sensitive adhesive.

[0046] The reason why the glass transition temperature of the hot-melt pressure-sensitive adhesive decreases after adding phenyl silicone rubber: After adding phenyl silicone rubber, the phenyl and other groups in its molecular structure will destroy the regularity of the original polymer molecular chain of the hot-melt pressure-sensitive adhesive, making the crystallization process difficult, reducing the degree of crystallinity, and being more conducive to the movement of the molecular chain. The macroscopic manifestation is that Tg drops to below -20°C.

[0047] The molecular chain of phenyl silicone rubber contains silicon oxygen bonds (Si-O) with high bond energy, which makes the entire molecular structure relatively stable at high temperatures and not prone to breakage or deformation. When it is added to hot melt pressure sensitive adhesive, it can significantly improve the high temperature resistance of the hot melt pressure sensitive adhesive, ensuring that the hot melt pressure sensitive adhesive can still maintain a certain shape and viscosity at high temperatures, thereby ensuring its bonding performance under high temperature conditions.

[0048] Preferably, the hydrogenated styrene block copolymer SEBS has a styrene content of 25-35%, a diblock content of <1wt%, a toluene solution viscosity of 440cps, a Shore hardness of 65-80A / 10 seconds, a tensile strength of 15-35MPa, and an elongation at break of 250-800%.

[0049] Preferably, the SEPS has a styrene content of 20-40%; a diblock content of 100%; and a toluene solution viscosity of ≥50,000 cps.

[0050] Preferably, the softening point of the tackifying resin of the hydrogenated petroleum resin is 90-120°C; the number average molecular weight is 200-600 g / mol;

[0051] The antioxidant is selected from at least one of the antioxidant 1010 and the antioxidant 168 .

[0052] Furthermore, the present invention provides a method for preparing a hot melt pressure-sensitive adhesive, which is used to prepare the hot melt pressure-sensitive adhesive with high removability, comprising the following steps:

[0053] S1) weighing naphthenic oil, phenyl silicone rubber, hydrogenated styrene block copolymer, tackifying resin and antioxidant respectively according to the formula ratio, then adding the antioxidant and naphthenic oil into a container, and continuously stirring until the materials are evenly mixed to obtain a mixed solution;

[0054] S2) adding phenyl silicone rubber and hydrogenated styrene block copolymer to the mixed solution in sequence, and continuously stirring until the materials are completely dissolved, to obtain a rubber solution;

[0055] S3) adding tackifying resin to the stirred rubber solution in portions, and continuing stirring until the tackifying resin is completely dissolved, thereby obtaining the hot melt pressure-sensitive adhesive with high removability.

[0056] The preparation method of the hot melt pressure sensitive adhesive of the present invention has the advantages of simple process, simple production equipment and low manufacturing cost.

[0057] Preferably, in steps S1) to S3), the stirring and mixing temperature of the materials is 140-150°C.

[0058] 140-150℃ can discharge the gas generated during the material mixing process to the outside, avoiding bubble defects inside the hot melt pressure sensitive adhesive, thereby preventing the hot melt pressure sensitive adhesive from generating defects and pores during use.

[0059] Preferably, in step S1), the stirring time after adding the material is 5-20 minutes;

[0060] In step S2) and step S3), the stirring time after adding the materials is 20-90 minutes.

[0061] Mix the materials evenly and dissolve completely by continuous stirring.

[0062] The preferred cyclohexane oil is Sinopec KN4010; the preferred phenyl silicone rubber is 120# phenyl silicone produced by Guangzhou Laiso Chemical Technology Co., Ltd.; the preferred hydrogenated styrene block copolymer is TSRC 6152SEBS and Baling Petrochemical YH-4010SEPS; the preferred tackifying resin is Jinhai 6100 hydrogenated petroleum resin.

[0063] Preferably, the viscosity of the prepared hot melt pressure sensitive adhesive with high removability is 5500-6000 cps.

[0064] The viscosity of the prepared hot melt pressure sensitive adhesive is controlled to be 5500-6000 cps, which can ensure the use effect of the hot melt pressure sensitive adhesive.

[0065] Examples 1-3 and Comparative Examples 1-3

[0066] 1. According to the raw material ratio in Table 1, the hot melt pressure-sensitive adhesives of Examples 1-3 and Comparative Examples 1-3 were prepared in the following steps:

[0067] S1) weighing naphthenic oil, phenyl silicone rubber, hydrogenated styrene block copolymer, tackifying resin and antioxidant respectively according to the formula ratio, then adding the antioxidant and naphthenic oil into a container, and continuously stirring until the materials are evenly mixed to obtain a mixed solution;

[0068] S2) adding phenyl silicone rubber and hydrogenated styrene block copolymer to the mixed solution in sequence, and continuously stirring until the materials are completely dissolved, to obtain a rubber solution;

[0069] S3) adding tackifying resin to the stirred rubber solution in portions, and continuing stirring until the tackifying resin is completely dissolved, thereby obtaining the hot melt pressure-sensitive adhesive with high removability;

[0070] In steps S1) to S3), the stirring and mixing temperature of the materials is 140-150°C;

[0071] In step S1), the stirring time after adding the material is 5-20 minutes;

[0072] In step S2) and step S3), the stirring time after adding the materials is 20-90 minutes;

[0073] In the above preparation process, the cyclohexane oil used is Sinopec KN4010; the phenyl silicone rubber uses 120# phenyl silicone produced by Guangzhou Laiso Chemical Technology Co., Ltd.; the hydrogenated styrene block copolymer uses TSRC 6152SEBS and / or Baling Petrochemical YH-4010SEPS; the tackifying resin uses Jinhai 6100 hydrogenated petroleum resin; and the antioxidant uses antioxidant 1010.

[0074] 2. Performance Testing

[0075] 2.1 The glass transition temperatures of Examples 1-3 and Comparative Examples 1-3 were tested using the DSC test method in accordance with GB / T 19466.3-2004; the peel strengths of Examples 1-3 and Comparative Examples 1-3 were tested in accordance with GB / T 2792-2014, and the initial adhesion properties of Examples 1-3 and Comparative Examples 1-3 were tested using the inclined rolling ball method in accordance with GB / T4852-2002. The test results are shown in Table 1.

[0076] 2.2 The hot-melt pressure-sensitive adhesives of Examples 1-3 and Comparative Examples 1-3 were melted at the same temperature and coated on PET film, coated paper or BOPP film with the same amount of adhesive, and then cut into sheet samples of 10×10 cm in size and pasted on PE board, steel plate, glass, corrugated cardboard or A4 paper. After being placed at room temperature for 1 week, the adhesive film was torn off, and the corresponding adhesive residue was checked and recorded. The test results are shown in Table 1.

[0077] 2.3 The hot-melt pressure-sensitive adhesives of Examples 1-3 and Comparative Examples 1-3 were melted at the same temperature and coated on PET films with the same amount of adhesive, and then cut into sheet samples of 10×10 cm, respectively, and pasted on PE plates, steel plates or glass. After being placed at 10°C and 70°C for 1 week, the adhesive films were torn off, and the corresponding adhesive residues were checked and recorded. The test results are shown in Table 1.

[0078] Table 1 Raw material ratios and test results of Examples 1-3 and Comparative Examples 1-3

[0079]

[0080] In summary, the hot melt pressure-sensitive adhesive with high removability reduces the surface energy of the hot melt pressure-sensitive adhesive by adding phenyl silicone rubber to reduce the adhesion between the existing adhesive layer and the surface of the adherend, and improves the removability of the hot melt pressure-sensitive adhesive on the surface of the adherend.

[0081] In addition, the added phenyl silicone rubber can effectively reduce the glass transition temperature of the hot melt pressure sensitive adhesive to below -20°C, so that the hot melt pressure sensitive adhesive can maintain good removability at low temperature (10°C), room temperature (24°C) and high temperature (70°C).

[0082] Furthermore, the preparation method of the hot melt pressure-sensitive adhesive proposed in the present invention has the advantages of simple process, simple production equipment and low manufacturing cost.

[0083] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A hot melt pressure sensitive adhesive with high removability, characterized in that: The raw materials of the hot melt pressure sensitive adhesive include: Naphthenic oil, phenyl silicone rubber, hydrogenated styrene block copolymer and tackifying resin; The phenyl silicone rubber is a surface energy improver, and the tackifying resin is a hydrogenated petroleum resin.

2. The hot-melt pressure-sensitive adhesive with high removability according to claim 1, characterized in that: Calculated by mass percentage, the raw materials of the hot melt pressure sensitive adhesive include: Naphthenic oil 12-18%, phenyl silicone rubber 12-18%, hydrogenated styrene block copolymer 28-35%, tackifying resin 35-55% and antioxidant 0.2-0.8%.

3. The hot melt pressure sensitive adhesive with high removability according to claim 1, characterized in that: The pour point of the naphthenic oil is -25 to -10°C; the flash point is 200-240°C; the density at 20°C is 850-950 kg / m 3 ; The viscosity constant is 0.820-0.850; the refractive index at 20°C is 1.45-1.52; the aniline point is 90-110°C; the CN in the carbon type analysis is greater than 40%; The phenyl silicone rubber has a phenyl content of 2.0-30.0 mol% and a vinyl content of 0.10-0.35 wt%.

4. The hot-melt pressure-sensitive adhesive with high removability according to claim 1, characterized in that: The hydrogenated styrene block copolymer SEBS has a styrene content of 25-35%, a diblock content of <1wt%, a toluene solution viscosity of 440cps, a Shore hardness of 65-80A / 10 seconds, a tensile strength of 15-35MPa, and a breaking elongation of 250-800%.

5. The hot melt pressure sensitive adhesive with high removability according to claim 1, characterized in that: The SEPS has a styrene content of 20-40% and a diblock content of 100%; and a toluene solution viscosity of ≥50000 cps.

6. The hot melt pressure sensitive adhesive with high removability according to claim 1, characterized in that: The softening point of the tackifying resin of the hydrogenated petroleum resin is 90-120° C.; the number average molecular weight is 200-600 g / mol; The antioxidant is selected from at least one of the antioxidant 1010 and the antioxidant 168 .

7. A method for preparing a hot melt pressure sensitive adhesive, characterized in that: The method for preparing the hot melt pressure-sensitive adhesive with high removability according to any one of claims 1 to 6 comprises the following steps: S1) weighing naphthenic oil, phenyl silicone rubber, hydrogenated styrene block copolymer, tackifying resin and antioxidant respectively according to the formula ratio, then adding the antioxidant and naphthenic oil into a container, and continuously stirring until the materials are evenly mixed to obtain a mixed solution; S2) adding phenyl silicone rubber and hydrogenated styrene block copolymer to the mixed solution in sequence, and continuously stirring until the materials are completely dissolved, to obtain a rubber solution; S3) adding tackifying resin to the stirred rubber solution in portions, and continuing stirring until the tackifying resin is completely dissolved, thereby obtaining the hot melt pressure-sensitive adhesive with high removability.

8. The method for preparing the hot melt pressure sensitive adhesive according to claim 7, characterized in that: In steps S1) to S3), the stirring and mixing temperature of the materials is 140-150°C.

9. The method for preparing the hot melt pressure sensitive adhesive according to claim 7, characterized in that: In step S1), the stirring time after adding the material is 5-20 minutes; In step S2) and step S3), the stirring time after adding the materials is 20-90 minutes.

10. The method for preparing the hot melt pressure sensitive adhesive according to claim 7, characterized in that: The viscosity of the prepared hot-melt pressure-sensitive adhesive with high removability is 5500-6000 cps.

Images