Hot-melt pressure-sensitive adhesive for magic tape and preparation method of hot-melt pressure-sensitive adhesive

Abstract

The invention discloses a magic tape hot-melt pressure-sensitive adhesive and a preparation method thereof, relates to the technical field of hot-melt pressure-sensitive adhesives, and aims to solve the problems of hot-melt pressure-sensitive adhesives, the magic tape hot-melt pressure-sensitive adhesive comprises the following components: 30-50 parts of a thermoplastic elastomer, 20-40 parts of tackifying resin, 10-20 parts of a softener, 0.5-2 parts of an antioxidant, and 5-15 parts of a filler. By reasonably selecting the thermoplastic elastomer, the tackifying resin and other components and the proportion thereof and adopting the mode of combining circulating spraying stirring and blade stirring, the hot-melt pressure-sensitive adhesive has excellent bonding strength, the circulating spraying stirring and the blade stirring are combined, the mixing uniformity is remarkably improved, the reaction process is accelerated, and the production cost is reduced. Meanwhile, the equipment loss is reduced, the paddles do not need to always keep high-speed operation, the abrasion of the paddles caused by long-time high-speed stirring is reduced, the scouring to the inner wall of the reaction kettle is correspondingly reduced, the equipment maintenance cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hot melt pressure - sensitive adhesives, and specifically relates to a hook - and - loop hot melt pressure - sensitive adhesive and a preparation method thereof. Background Art

[0002] Hook - and - loop fasteners, as a kind of connecting material widely used in the fields of clothing, footwear, luggage, electronic products, etc., the quality of their performance largely depends on the adhesives used. Due to the advantages of no need for solvents, environmental protection, high production efficiency, rapid bonding, etc., hot melt pressure - sensitive adhesives have become one of the ideal choices for hook - and - loop fastener adhesives;

[0003] In the actual preparation process of the existing hook - and - loop hot melt pressure - sensitive adhesives, due to processing defects, the mixing degree of the hot melt pressure - sensitive adhesives is often poor, so that the bonding strength of the hot melt pressure - sensitive adhesives is insufficient during actual use. Furthermore, when used for a long time or under a large external force, the hook - and - loop fasteners are likely to fall off, affecting the normal use of the products. Summary of the Invention

[0004] To solve the above - mentioned technical problems, a hook - and - loop hot melt pressure - sensitive adhesive and a preparation method thereof are provided, which solve the problems in the background art.

[0005] To achieve the above - mentioned purpose, the technical scheme adopted by the present invention is as follows: A hook - and - loop hot melt pressure - sensitive adhesive, comprising the following components:

[0006] 30 - 50 parts of thermoplastic elastomer, 20 - 40 parts of tackifying resin, 10 - 20 parts of softening agent, 0.5 - 2 parts of antioxidant, and 5 - 15 parts of filler.

[0007] Preferably, the thermoplastic elastomer is one or two of styrene - butadiene - styrene block copolymer (SBS) and styrene - isoprene - styrene block copolymer (SIS). The thermoplastic elastomer provides good flexibility and initial tack for the adhesive, enabling it to quickly adhere to the surface of the hook - and - loop fastener;

[0008] The tackifying resin is one or more of terpene resin, rosin resin, and petroleum resin. The tackifying resin can significantly improve the bonding strength of the adhesive and enhance the adhesion to the hook - and - loop fastener and the adherend;

[0009] The softening agent is one or more of naphthenic oil and paraffin oil. The softening agent can improve the processing performance of the adhesive, reduce its melt viscosity, and at the same time improve the flexibility of the adhesive, making the hook - and - loop fastener not easily damaged during bending;

[0010] The antioxidant is one or more of hindered phenol antioxidant 1010 and phosphite antioxidant 168. The antioxidant can prevent the adhesive from undergoing oxidative degradation during preparation and use, and improve its weather resistance and storage stability;

[0011] The filler is one or more of calcium carbonate and talcum powder. The addition of the filler can adjust the hardness and viscosity of the adhesive, and at the same time reduce the cost.

[0012] A preparation method of a magic tape hot melt pressure-sensitive adhesive comprises the following steps:

[0013] S1. Raw material preparation: Weigh the thermoplastic elastomer, tackifying resin, softening agent, antioxidant and filler according to the above weight parts;

[0014] S2. Melting of the thermoplastic elastomer: Add the thermoplastic elastomer into a special reaction kettle equipped with a combination of paddle stirring and circulating spraying. First, turn on the paddle stirring, and set the speed to 100 r / min. At the same time, start the circulating pump to make the material start to circulate at a flow rate of 5-8 L / min, and stir and melt at 120-150 °C until the thermoplastic elastomer is completely melted into a uniform fluid. The paddle stirring provides the main shear force to accelerate the melting of the thermoplastic elastomer, and the circulating spraying helps the heat to be more evenly distributed, avoiding local overheating, ensuring that the temperature in the whole reaction kettle is uniform, and creating good conditions for the subsequent component mixing;

[0015] S3. Adding the softening agent: After the thermoplastic elastomer is completely melted, slowly add the softening agent, adjust the paddle stirring speed to 80-100 r / min, and increase the circulating pump flow rate to 10-15 L / min, and continue stirring for 15-30 minutes to make the softening agent and the thermoplastic elastomer fully mixed and uniform. At this stage, the paddle stirring makes the material form a circular motion in the kettle, and the circulating spraying sprays the material from the top to form a vertical convection, greatly increasing the mixing path of the material and effectively improving the mixing efficiency;

[0016] S4. Adding the antioxidant: Add the antioxidant into the special reaction kettle, maintain the paddle stirring speed at 80-100 r / min, keep the circulating pump flow rate at 10-15 L / min, and stir for 10-20 minutes to ensure that the antioxidant is evenly dispersed in the system;

[0017] S5. Add tackifying resin: Gradually add the tackifying resin, heat up to 160 - 180 °C, adjust the stirring speed of the paddle to 100 - 120 r / min, keep the flow rate of the circulation pump stable at 10 - 15 L / min, so that the tackifying resin is completely dissolved and reacts fully with other components. The reaction time is 30 - 60 minutes. The combination of circulating spray stirring and paddle stirring can accelerate the reaction. The fresh material supplement and uniform heat distribution brought by the circulating spray, and the good mass transfer conditions provided by the paddle stirring work together, enabling the tackifying resin to dissolve faster and react with other components to form a more stable chemical bond structure that is beneficial to bonding.

[0018] S6. Add filler: Slowly add the filler into the reaction kettle, reduce the stirring speed of the paddle to 70 - 90 r / min, the circulation pump continues to work at a stable flow rate, and continue stirring for 20 - 30 minutes to evenly disperse the filler in the adhesive. The circulating spray continuously drives the material circulation, so that the calcium carbonate particles collide and mix with other components continuously during the flow process. The fine adjustment of the paddle ensures the stability of the overall flow of the material in the kettle, avoiding the occurrence of local dead zones, and finally achieving the full mixing of each component at the micro and macro levels.

[0019] S7. Discharge: Transport the prepared hot melt pressure - sensitive adhesive to the storage tank or packaging container through the pipeline, and the finished product can be obtained after cooling.

[0020] Preferably, the special reaction kettle provided according to S mainly consists of a reaction kettle body with an open top, a stirring device, and a pumping device.

[0021] The stirring device includes a stirring rod vertically rotating on the inner wall of the bottom end of the reaction kettle body and several stirring paddles surrounding the rod body of the stirring rod.

[0022] The pumping device includes a suction pipe standing between the stirring paddle and the inner wall of the reaction kettle body. The open end of the reaction kettle body is rotatably connected with a transmission disc. A suction part matching with the suction pipe is arranged on the transmission disc, and a transmission connection part is arranged between the transmission disc and the driving motor.

[0023] Preferably, the suction part includes a pump installed on the outer periphery of the top surface of the transmission disc. A discharge pipe fixedly communicated with the output end of the pump penetrates through the center of the transmission disc. The suction end of the pump is fixedly communicated with a suction pipe, and the end of the suction pipe penetrates into the reaction kettle body and is fixedly communicated with the suction pipe.

[0024] Preferably, the transmission connection includes a supply rotating seat vertically fixed on the barrel wall of the reaction kettle body, a supply rotating rod vertically rotating in the inner wall of the supply rotating seat, and a transmission gear tightly sleeved on one end of the supply rotating rod. Several tooth blocks meshing with the transmission gear are fixedly surrounded on the outer periphery of the transmission disc.

[0025] Preferably, a transmission belt is connected between the other end of the supply rotating rod and the output shaft of the drive motor for transmission.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] (1) By reasonably selecting components such as thermoplastic elastomers and tackifying resins and their ratios, and adopting a combination of circulating spray stirring and paddle stirring, the hot melt pressure-sensitive adhesive of the present invention has excellent bonding strength.

[0028] (2) The combination of circulating spray stirring and paddle stirring significantly improves the mixing uniformity, accelerates the reaction process, and reduces equipment wear. The paddle does not need to always run at a high speed, reducing the wear of the paddle caused by long-term high-speed stirring. At the same time, the scouring of the inner wall of the reaction kettle is also correspondingly reduced, reducing the equipment maintenance cost and improving the production efficiency. Description of the Drawings

[0029] Figure 1 It is a schematic diagram of the overall structure of the special reaction kettle of the present invention;

[0030] Figure 2 It is a schematic diagram of the internal structure of the special reaction kettle of the present invention.

[0031] The reference numerals in the figure are:

[0032] 1. Reaction kettle body; 2. Feeding bin; 3. Stirring rod; 4. Stirring paddle; 5. Drive motor; 6. Discharge pipe; 7. Suction pipe; 8. Transmission disc; 9. Pump; 10. Suction pipe; 11. Drain pipe; 12. Supply rotating rod; 13. Supply rotating seat; 14. Transmission gear; 15. Tooth block; 16. Transmission belt. Detailed Embodiments

[0033] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations.

[0034] Example 1

[0035] Raw material preparation: Weigh 30 parts of SBS, 20 parts of terpene resin, 10 parts of naphthenic oil, 0.5 part of antioxidant 1010, and 5 parts of calcium carbonate;

[0036] Preparation process:

[0037] Add SBS into a special reaction kettle equipped with a combination of paddle stirring and circulating spray, start the paddle stirring, set the speed to 100 r / min, and at the same time start the circulating pump to make the material start to circulate at a flow rate of 5 L / min, and stir and melt at 120 °C;

[0038] After the SBS is completely melted, slowly add naphthenic oil, adjust the paddle stirring speed to 80 r / min, increase the circulating pump flow rate to 10 L / min, and continue stirring for 15 minutes;

[0039] Add antioxidant 1010, maintain the paddle stirring speed at 80 r / min, keep the circulating pump flow rate at 10 L / min, and stir for 10 minutes;

[0040] Gradually add terpene resin, heat up to 160 °C, adjust the paddle stirring speed to 100 r / min, keep the circulating pump flow rate stable at 10 L / min, and stir for 30 minutes;

[0041] Slowly add calcium carbonate, reduce the paddle stirring speed to 70 r / min, keep the circulating pump working at a stable flow rate, and stir for 20 minutes;

[0042] Discharge the prepared hot melt pressure-sensitive adhesive into the storage tank.

[0043] Example 2

[0044] Raw material preparation: Weigh 40 parts of SIS, 30 parts of rosin resin, 15 parts of paraffin oil, 1 part of antioxidant 168, and 10 parts of talcum powder.

[0045] Preparation process:

[0046] Add SIS to a special reaction kettle, start the paddle stirring, set the speed to 100 r / min, at the same time start the circulating pump, and make the material start to circulate at a flow rate of 6 L / min, and stir and melt at 135 °C.

[0047] After the SIS is completely melted, slowly add paraffin oil, adjust the paddle stirring speed to 90 r / min, increase the circulating pump flow rate to 12 L / min, and continue stirring for 20 minutes;

[0048] Add antioxidant 168, maintain the paddle stirring speed at 90 r / min, keep the circulating pump flow rate at 12 L / min, and stir for 15 minutes;

[0049] Gradually add rosin resin, heat up to 170 °C, adjust the paddle stirring speed to 110 r / min, keep the circulating pump flow rate stable at 12 L / min, and stir for 45 minutes;

[0050] Slowly add talcum powder, reduce the paddle stirring speed to 80 r / min, keep the circulating pump working at a stable flow rate, and stir for 25 minutes;

[0051] Discharge the prepared hot melt pressure-sensitive adhesive into the packaging container.

[0052] Example 3

[0053] Raw material preparation: Weigh 50 parts of the mixture of SBS and SIS (mass ratio 1:1), 40 parts of petroleum resin, 20 parts of naphthenic oil, 2 parts of the mixture of antioxidant 1010 and 168 (mass ratio 1:1), and 15 parts of calcium carbonate.

[0054] Preparation process:

[0055] Add the mixture of SBS and SIS into a special reaction kettle, start the paddle stirring, set the speed to 100 r / min, and at the same time start the circulation pump to make the material start to circulate at a flow rate of 8 L / min, and stir and melt at 150 °C;

[0056] After complete melting, slowly add naphthenic oil, adjust the paddle stirring speed to 100 r / min, increase the circulation pump flow rate to 15 L / min, and continue stirring for 30 minutes;

[0057] Add the antioxidant mixture, maintain the paddle stirring speed at 100 r / min, keep the circulation pump flow rate at 15 L / min, and stir for 20 minutes;

[0058] Gradually add petroleum resin, raise the temperature to 180 °C, adjust the paddle stirring speed to 120 r / min, keep the circulation pump flow rate stable at 15 L / min, and stir for 60 minutes;

[0059] Slowly add calcium carbonate, reduce the paddle stirring speed to 90 r / min, the circulation pump continues to work at a stable flow rate, and stir for 30 minutes;

[0060] Discharge the prepared hot melt pressure-sensitive adhesive.

[0061] Comparative example 1

[0062] Use a commercially available ordinary hook and loop hot melt pressure-sensitive adhesive as the comparative example.

[0063]

[0064] It can be seen that the hook and loop hot melt pressure-sensitive adhesive prepared in the embodiment of the present invention is significantly superior to the commercially available hot melt pressure-sensitive adhesive in the comparative example in terms of bonding strength, fully demonstrating the superiority of the present invention.

[0065] In addition, as shown in Figure 1 and Figure 2 It is worth noting that the above special reaction kettle mainly consists of a reaction kettle body 1 with an open top, a stirring device, and a pump feeding device. A feeding bin 2 is fixedly connected to the barrel wall of the reaction kettle body 1, and a discharge pipe 6 is fixedly connected to one side of the bottom end of the reaction kettle body 1. An electromagnetic valve is arranged on the discharge pipe 6;

[0066] Among them, the reactor body 1 is a common CY-12 electric heating reactor on the existing market. Generally, heating wires are arranged on its inner wall to continuously supply heat to the inner cavity of the reactor body 1 during the operation of the equipment for stirring materials, so that the raw materials are melted. Therefore, as a heating reaction device commonly used conventionally, the specific inner wall heating structure and circuit principle of this case will not be elaborated too much;

[0067] Among them, the stirring device includes a stirring rod 3 vertically rotating on the inner wall of the bottom end of the reactor body 1, several stirring blades 4 surrounding the rod body of the stirring rod 3, and a driving motor 5 installed at the bottom end of the reactor body 1 through a bracket. The output shaft of the driving motor 5 rotates through the reactor body 1 and is fixedly connected to the bottom end of the stirring rod 3;

[0068] When the driving motor 5 is started, the output shaft of the driving motor 5 drives the stirring rod 3 and the stirring blades 4 as a whole, so that the stirring blades 4 continuously stir the materials in the inner cavity of the reactor body 1.

[0069] However, the stirring device is a conventional single-blade stirring. It mainly relies on the rotation of the blade to push the materials to flow in the area near the blade. The mixing range is limited, and it is easy to have stirring dead angles, resulting in insufficient mixing of some materials and insufficient stirring. The various raw material components of these hot melt pressure-sensitive adhesives cannot be evenly dispersed, making it difficult to form a stable structure, thereby reducing the bonding strength of the hot melt pressure-sensitive adhesive;

[0070] For this reason, referring to Figure 2 As shown, it is worth noting that the pumping device includes a suction pipe 7 erected between the stirring blade 4 and the inner wall of the reactor body 1. The open end of the reactor body 1 is rotatably connected with a transmission disc 8. A suction part matching with the suction pipe 7 is arranged on the transmission disc 8, and a transmission connection part is arranged between the transmission disc 8 and the driving motor 5;

[0071] The suction part includes a pump 9 installed on the outer periphery of the top surface of the transmission disc 8. A discharge pipe 11 fixedly communicated with the output end of the pump 9 penetrates through the center of the transmission disc 8. The suction end of the pump 9 is fixedly communicated with a suction pipe 10. The end of the suction pipe 10 penetrates into the reactor body 1 and is fixedly communicated with the suction pipe 7;

[0072] Through the setting of the pumping device, during the process of starting the driving motor 5 and acting on the stirring blade 4 to continuously stir the materials, the suction pipe 7 in the pumping device rotates synchronously in the area between the stirring blade 4 and the inner wall of the reactor body 1 to stir the materials in the outer area of the stirring blade 4, thereby reducing the stirring dead angle to a certain extent, sharing part of the stirring work to a certain extent, shortening the stirring time of the materials, reducing the wear of the stirring blade 4 caused by long-term high-speed stirring, and reducing the equipment maintenance cost;

[0073] The pump 9 is turned on, and the suction end of the pump 9 continuously sucks the pre-heated material outside the stirring blade 4 through the suction pipe 10 and the suction pipe 7, and the sucked material is sprayed and pumped downward from the central area through the discharge pipe 11, thereby improving the uniformity of heating of the material inside and outside the stirring range of the stirring blade 4, ensuring that the material reacts at a suitable and uniform temperature, which is conducive to the formation of a stable and bonding chemical bond structure;

[0074] In addition, the material sprayed down from the top at high speed can produce strong impact and convection with the original material in the kettle, promoting a closer blending of the components on a microscopic scale. For example, the tiny particles of the tackifying resin can be more evenly dispersed in the continuous phase of the thermoplastic elastomer, which helps to improve the final bonding strength of the hot melt adhesive.

[0075] Further, refer to Figure 2 As shown, it is worth noting that the transmission connection includes a supply rotation seat 13 vertically fixed on the cylinder wall of the reactor body 1, a supply rotation rod 12 vertically rotating in the inner wall of the supply rotation seat 13, and a transmission gear 14 tightly sleeved on one end of the supply rotation rod 12, and a plurality of gear blocks 15 meshing with the transmission gear 14 are fixed around the outer periphery of the transmission disc 8;

[0076] A transmission belt 16 is connected between the other end of the rotating rod 12 and the output shaft of the driving motor 5;

[0077] When the driving motor 5 is started, the output shaft of the driving motor 5 can be driven by the driving belt 16 to rotate the supply rod 12 and the transmission gear 14, so that the transmission gear 14 is meshed with the gear block 15, thereby rotating the transmission disk 8, the pump machine 9 and the suction tube 7 as a whole.

[0078] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A Velcro hot melt pressure sensitive adhesive, characterized in that: The components include: 30-50 parts of thermoplastic elastomer, 20-40 parts of tackifying resin, 10-20 parts of softener, 0.5-2 parts of antioxidant, and 5-15 parts of filler.

2. The Velcro hot melt pressure sensitive adhesive according to claim 1, characterized in that: The thermoplastic elastomer is one or two of styrene-butadiene-styrene block copolymer (SBS) and styrene-isoprene-styrene block copolymer (SIS); The tackifying resin is one or more of terpene resin, rosin resin and petroleum resin; The softener is one or more of naphthenic oil and paraffin oil; The antioxidant is one or more of a hindered phenol antioxidant 1010 and a phosphite antioxidant 168; The filler is one or more of calcium carbonate and talc.

3. A method for preparing a Velcro hot melt pressure sensitive adhesive, characterized in that: The steps include: S1. Raw material preparation: weigh thermoplastic elastomer, tackifying resin, softener, antioxidant and filler according to the above weight parts; S2. Melting of thermoplastic elastomer: Add the thermoplastic elastomer into a special reactor equipped with paddle stirring and circulating spraying. Start the paddle stirring in advance and set the speed to 100r / min. Start the circulating pump at the same time to circulate the material at a flow rate of 5-8L / min. Stir and melt at 120-150℃ until the thermoplastic elastomer is completely melted into a uniform fluid. S3. Adding softener: After the thermoplastic elastomer is completely melted, slowly add the softener, adjust the stirring speed of the paddle to 80-100r / min, increase the flow rate of the circulating pump to 10-15L / min, and continue stirring for 15-30 minutes to fully mix the softener and the thermoplastic elastomer; S4. Add antioxidant: Add antioxidant into the special reactor, maintain the stirring speed of blade at 80-100r / min, maintain the flow rate of circulating pump at 10-15L / min, and stir for 10-20 minutes to ensure that the antioxidant is evenly dispersed in the system; S5. Adding tackifying resin: gradually add tackifying resin, raise the temperature to 160-180°C, adjust the stirring speed of the paddle to 100-120r / min, stabilize the flow rate of the circulating pump at 10-15L / min, so that the tackifying resin is completely dissolved and fully reacts with other components, and the reaction time is 30-60 minutes; S6. Add filler: slowly add the filler into the reactor, reduce the stirring speed of the paddle to 70-90r / min, keep the circulating pump working at a stable flow rate, and continue stirring for 20-30 minutes to evenly disperse the filler in the adhesive; S7, discharging: the prepared hot melt pressure sensitive adhesive is transported to a storage tank or a packaging container through a pipeline, and the finished product is obtained after cooling.

4. The method for preparing a Velcro hot melt pressure sensitive adhesive according to claim 3, characterized in that: The special reactor provided by S2 mainly comprises a reactor body (1) with an open top, a stirring device and a pumping device; The stirring device comprises a stirring rod (3) vertically rotating on the inner wall of the bottom end of the reactor body (1) and a plurality of stirring blades (4) surrounding the rod body of the stirring rod (3); The pumping device comprises a suction pipe (7) erected between the stirring blade (4) and the inner wall of the reactor body (1); the open end of the reactor body (1) is rotatably connected to a transmission disk (8); a suction portion cooperating with the suction pipe (7) is provided on the transmission disk (8); and a transmission connection portion is provided between the transmission disk (8) and the drive motor (5).

5. The method for preparing a Velcro hot melt pressure sensitive adhesive according to claim 4, characterized in that: The suction part comprises a pump (9) mounted on the outer periphery of the top surface of the transmission disc (8); a discharge pipe (11) is passed through the center of the transmission disc (8) and is fixedly connected to the output end of the pump (9); the suction end of the pump (9) is fixedly connected to a suction pipe (10); the end of the suction pipe (10) penetrates into the reactor body (1) and is fixedly connected to the suction pipe (7).

6. The method for preparing a Velcro hot melt pressure sensitive adhesive according to claim 5, characterized in that: The transmission connection comprises a rotating seat (13) vertically fixed on the cylinder wall of the reactor body (1), a rotating rod (12) vertically rotating in the inner wall of the rotating seat (13), and a transmission gear (14) tightly sleeved on one end of the rotating rod (12), and a plurality of tooth blocks (15) meshing with the transmission gear (14) are fixed around the outer periphery of the transmission disc (8).

7. The method for preparing a Velcro hot melt pressure sensitive adhesive according to claim 6, characterized in that: A transmission belt (16) is connected between the other end of the rotation supply rod (12) and the output shaft of the driving motor (5).

Images