Double-sided composite ultrahigh-viscosity self-adhesive film, production process and equipment

Abstract

The invention discloses a double-sided composite ultrahigh-viscosity self-adhesive film, a production process and equipment, the self-adhesive film comprises a base material layer and an adhesive layer, and the base material layer comprises a surface layer, a middle layer and a bottom layer; the formula of the surface layer comprises 90% of LDPE (Low-Density Polyethylene) and 10% of Exfin; the Exfin is a three-well chemical'silicon-like polyolefin copolymerization master batch '; the formula of the middle layer comprises 70% of LLDPE, 20% of LDPE and 10% of rim charge; and the formula of the bottom layer comprises 95% of LDPE and 5% of SEBS. And the formula of the adhesive layer comprises the following components: 30 parts of SEBS, 40-60 parts of tackifying resin, 10-20 parts of white oil, 1 part of fumed silica and 0.5 part of antioxidant 1010. According to the production process, casting co-extrusion is combined with a coating system, multi-layer materials with great difference can be stably subjected to interlayer melting convergence to form the ultrahigh-viscosity protective film at a time, and the production efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of self-adhesive films, and in particular to a double-sided composite ultra-high-viscosity self-adhesive film, a production process and equipment. Background Art

[0002] Currently, traditional ultra-high viscosity tape protective films are almost all produced by the coating method. The acrylic adhesive is dissolved in proportion using a solvent and then applied to the surface of the substrate. The solvent is then volatilized through curing to form a cross-linked adhesive. In addition to its own polarity that can provide a higher peel force, the lower bulk viscosity enables it to quickly wet the surface during bonding, making it more likely to "cold flow" at room temperature, thereby achieving good adhesion, especially on extremely rough surfaces.

[0003] With the development of technology, multi-layer co-extrusion self-adhesive process formula has developed rapidly due to its "low cost, no degumming, environmental protection" and other factors, thus replacing most of the low, medium and high viscosity markets of the original glue coating. This type of process usually uses a non-polar "polyolefin elastomer + tackifying resin" as a self-adhesive layer. If you want to make ultra-high viscosity materials, you often need to add a lot of tackifying resins and other additives. After adding more tackifying resins, the melt index (hereinafter referred to as "MI") of the material will increase rapidly. Ultra-high viscosity materials often have ultra-high MI. When traditional multi-layer co-extrusion self-adhesive cast film equipment and blown film equipment are used, it is difficult for two materials with large MI differences (230 degrees 2.16kg test greater than 20) to stably merge between layers in a one-time molding method, and it is difficult to directly form a film.

[0004] Therefore, how to provide a double-sided composite ultra-high viscosity self-adhesive film, production process and equipment to solve the problems existing in the prior art is of great significance to its application. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a double-sided composite ultra-high viscosity self-adhesive film, a production process and an apparatus, wherein the self-adhesive film comprises a substrate layer and an adhesive layer, wherein the substrate layer comprises a surface layer, a middle layer and a bottom layer;

[0006] The formula of the surface layer is LDPE 90% + Exforma 10%;

[0007] The formula of the middle layer is LLDPE 70% + LDPE 20% + edge material 10%;

[0008] The formula of the bottom layer is LDPE 95% + SEBS 5%.

[0009] Preferably, the formula of the adhesive layer is: 30 components of SEBS, 40-60 components of tackifying resin, 10-20 components of white oil, 1 component of fumed silica, and 0.5 component of antioxidant 1010.

[0010] Exfolia is Mitsui Chemicals' "Silicone-Polyolefin Copolymer Masterbatch"

[0011] Preferably, the production process and equipment are characterized in that: the production equipment includes an extruder, a weighing mechanism, a substrate layer die, a dispenser, a bonding layer die, a pressure roller, a forming roller, a thickness gauge, a trimming mechanism, a corona mechanism, a silicon coating roller, a curing box, a visual inspection mechanism, and a winding roller;

[0012] The number of the extruders is four, the number of the distributors is two, wherein the discharge ends of three of the extruders are connected to the substrate layer die through one of the distributors, and the discharge end of the other extruder is directly connected to the adhesive layer die;

[0013] The outputs of the substrate layer die and the adhesive layer die are co-extruded into a primary film by a pressure roller and a molding roller. The primary film is trimmed by a trimming mechanism and then measured by a thickness gauge. The primary film is corona-treated by a corona mechanism and then coated with silicone oil by a silicon-coating roller and then cured by a curing box to form a formed film. The visual inspection mechanism captures defects on the formed film for quality control and then rewinds it through a rewinding roller.

[0014] Preferably, the extruders are respectively a first extruder A, a second extruder B, a third extruder C, and a fourth extruder D, wherein the first extruder A, the second extruder B, and the third extruder C are respectively used to extrude the surface layer, the middle layer, and the bottom layer of the self-adhesive film substrate layer, and the fourth extruder D is used to extrude the adhesive layer of the self-adhesive film.

[0015] Preferably, the production method comprises the following steps:

[0016] S1: Prepare the adhesive layer masterbatch in advance according to the adhesive layer formula;

[0017] S2: Put the sticky layer masterbatch into the fourth extruder D to prepare the sticky layer, and at the same time, according to the formula of the substrate layer, put it into the first extruder A, the second extruder B, and the third extruder C respectively according to the ratio of the surface layer, the middle layer, and the bottom layer;

[0018] S3: The substrate layer and the adhesive layer are extruded through a substrate layer die and an adhesive layer die respectively, and co-extruded into a primary film through a pressure roller and a forming roller;

[0019] S4: the initial film is trimmed by a trimming mechanism and then measured by a thickness gauge;

[0020] S5: When a better release effect is required, the initial film can be coronaed by a corona device, coated with silicone oil by a silicon coating roller, and then cured in a curing box to form a surface release self-adhesive film;

[0021] S6: The visual inspection mechanism captures defects on the formed film for quality control and then rewinds the film through a reel.

[0022] Preferably, in S1, a two-stage underwater granulation system is used, including a first granulator and a second granulator. The first granulator is preferably a co-rotating three-screw device with an aspect ratio greater than 68, and the granulation temperature is 120-160 degrees. The material is discharged from the discharge port of the first granulator and enters the double-cone feeder. The side-force feeding method is adopted, and the discharge port of the double-cone feeder is vertically entered into the feed port of the second single-screw granulator at 90 degrees. The second granulator preferably adopts a "high compression ratio" machine with a screw diameter greater than 100 mm and an aspect ratio greater than 48, and the screw temperature is 80-100 degrees. The first granulator adopts the first stage natural exhaust and the second stage vacuum pumping method to treat volatiles. The second extruder adopts natural exhaust method for molding. 0.5% of the fumed silica is mixed in the first granulator, and the remaining 0.5% is sprinkled on the molded particles as an anti-sticking release agent to prevent adhesion to obtain a sticky layer masterbatch.

[0023] Preferably, in S2, the masterbatch prepared in S1 is added into a fourth extruder D and extruded into a film at a temperature of about 100-120 degrees.

[0024] Preferably, the components of the substrate layer are respectively put into corresponding ABC molds for extrusion into films, and the processing temperature is 230 degrees.

[0025] Preferably, the distance between the substrate layer die head and the contact surface of the forming roller is 10-20 cm. By adjusting the screw speed and the roller traction speed, extrusion compounding is performed at a ratio of 20% for the adhesive layer and 80% for the substrate, and a film with a thickness of 80 um is formed after passing through a cooling roller.

[0026] Preferably, the width of the substrate layer die is 1600mm, the substrate layer die preferably has a die gap of 1.0-1.2mm, the sticking layer die gap is preferably 0.6-0.8mm, the fourth extruder 1D is preferably equipped with a melt pump to provide stable delivery pressure to the die to discharge the film, the screw diameters of the first extruder A, the second extruder B, and the third extruder C are: 50mm / 80mm / 50mm, the diameter of the fourth extruder is 50mm, the casting cooling roller is preferably a mirror roller with a surface roughness (Ra) of 0.02um, and the remaining rollers that contact the rubber layer during the traction process are treated with "plasma anti-sticking and anti-slip" and are rolled up.

[0027] Preferably, in S5, an air floating roller is used inside the curing box to transport the film in a non-contact manner.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention adopts the form of forming the substrate and the adhesive layer separately into films and then compounding them by rollers at high temperature, which can realize the processing of different materials with a temperature difference of about 80-150 degrees. The substrate is processed at 220-240 degrees. Since the MI of the adhesive layer is too high, the fluidity can be adjusted at low temperature (100-150), so that the substrate and the adhesive layer can be combined at a relatively stable melt strength;

[0030] 2. The substrate of the present invention is divided into three layers, and the edge material can be added in the middle. The other two layers of relatively clean materials can wrap the crystal point protrusions caused by the recovery of the edge material in the molten state, making the film surface smoother;

[0031] 3. After the substrate is divided into three parts, the thickness of the surface layer is significantly reduced. After adding the release material inside, the overall film cost is less affected. The layer of substrate in contact with the adhesive layer can be added with materials that increase the interlayer adhesion, so that the film layers are more solid and will not delaminate;

[0032] 4. In the present invention, a silicon coating and curing system is provided. If there is still a problem with the release after the release agent is added to the internal limit, the release agent can be switched to a method without adding the release agent. The back layer is made of pure PE material and then corona silicon coating and curing is performed to form a release layer, so that the film can obtain a good unwinding effect before winding;

[0033] 5. In the present invention, the self-adhesive material adopts a double-stage form of three screws with a longer aspect ratio and single screw pelletizing, which gives each component additive sufficient melting time, avoiding the precipitation of white oil softeners in the later stage. Multi-stage natural exhaust can fully remove low-molecular volatile substances and prevent low-molecular substances from precipitating in the later stage. The use of silica isolation powder can effectively prevent the adhesion of the adhesive masterbatch during storage, and can also be used as a filler to improve the temperature resistance of the membrane adhesive layer;

[0034] 6. The self-adhesive layer extruder of the present invention is equipped with a melt pump, so that the self-adhesive material with lower bulk viscosity can be stably output to the mold during high-temperature processing, and sufficient back pressure is provided for the feed material, so that the adhesive layer after the film is plasticized uniformly, has good thickness uniformity, and has uniform viscosity;

[0035] 7. In the coating curing system of the present invention, when heat curing or ultraviolet curing is performed, the heat source or light source comes from above, and the adhesive layer is bound to contact the traction roller. Especially when high-temperature curing is performed, the film will become sticky. The air floating roller method used evenly punches (1mm) holes on the roller surface, and the film is floated by compressed air, avoiding the "roller sticking phenomenon" in this link.

[0036] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application so that it can be implemented in accordance with the contents of the specification, and to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following is a detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings as follows.

[0037] Based on the detailed description of the specific embodiments of the present application in combination with the accompanying drawings below, those skilled in the art will become more aware of the above and other objects, advantages and features of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale.

[0039] Figure 1 It is a structural schematic diagram of the production equipment in the present invention;

[0040] Figure 2 is a layered diagram of the self-adhesive film of the present invention;

[0041] Figure 3 This is a formula diagram of the adhesive layer in the present invention;

[0042] Figure 4 The formula diagram of the substrate layer in the present invention;

[0043] Figure 5 Graph showing the test results of the adhesion example in the present invention.

[0044] In the figure: 1. extruder; 2. weighing mechanism; 3. substrate layer die; 4. dispenser; 5. adhesive layer die; 6. pressure roller; 7. forming roller; 8. thickness gauge; 9. trimming mechanism; 10. corona mechanism; 11. silicon coating roller; 12. fixing box; 13. visual inspection mechanism; 14. winding roller. DETAILED DESCRIPTION

[0045] To make the purpose, technical scheme and advantages of the embodiment of the present application clearer, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, rather than all of the embodiments. In the following description, specific details such as specific configuration and components are provided only to help fully understand the embodiments of the present application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, for clarity and brevity, the description of known functions and structures is omitted in the embodiment.

[0046] In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0047] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" in this article describes another type of association object relationship, indicating that there can be two relationships. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0048] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusions.

[0049] See also Figure 1-4 The present invention provides a technical solution of a double-sided composite ultra-high viscosity self-adhesive film, a production process and an equipment:

[0050] A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment, the production equipment includes an extruder 1, a weighing mechanism 2, a substrate layer die 3, a dispenser 4, an adhesive layer die 5, a pressing roller 6, a forming roller 7, a thickness gauge 8, a trimming mechanism 9, a corona mechanism 10, a silicon coating roller 11, a curing box 12, a visual inspection mechanism 13, and a winding roller 14;

[0051] There are four extruders 1 and two distributors 4, wherein the discharge ends of three extruders 1 are connected to the substrate layer die 3 through one of the distributors 4, and the discharge end of another extruder 1 is directly connected to the adhesive layer die 5;

[0052] The output of the substrate layer die 3 and the adhesive layer die 5 is co-extruded into a primary film through a pressure roller 6 and a molding roller 7. The primary film is trimmed by a trimming mechanism 9 and then measured by a thickness gauge 8. The primary film is corona-treated by a corona mechanism 10 and then coated with silicone oil by a silicon coating roller 11 and then cured by a curing box 12 to form a formed film. The visual inspection mechanism 13 captures defects on the formed film and then rewinds it through a reel 14.

[0053] The extruders 1 are respectively a first extruder 1A, a second extruder 1B, a third extruder 1C, and a fourth extruder 1D, wherein the first extruder 1A, the second extruder 1B, and the third extruder 1C are respectively used to extrude the surface layer, the middle layer, and the bottom layer of the self-adhesive film substrate layer, and the fourth extruder 1D is used to extrude the adhesive layer of the self-adhesive film.

[0054] The fourth extruder 1D is equipped with a melt pump, so that the self-adhesive material with lower bulk viscosity can be stably output to the mold during high-temperature processing, and sufficient back pressure is provided for the feeding, so that the adhesive layer after filming is plasticized evenly, with good thickness uniformity and uniform viscosity.

[0055] The formula of the surface layer is LDPE90% + Exfo l a10%;

[0056] The formula of the middle layer is LLDPE70%+LDPE20%+edge material10%;

[0057] The formula of the bottom layer is LDPE 95% + SEBS 5%.

[0058] The substrate is divided into three layers. Edge material can be added in the middle, and the other two layers of cleaner materials can wrap the crystal point protrusions caused by the recycling of edge material in a molten state, making the film surface smoother.

[0059] The formula of the adhesive layer is: 30 components of SEBS, 40-60 components of tackifying resin, 10-20 components of white oil, 1 component of fumed silica, and 0.5 components of antioxidant 1010.

[0060] The production method comprises the following steps:

[0061] S1: Prepare the adhesive layer masterbatch in advance according to the adhesive layer formula;

[0062] S2: Put the sticky layer masterbatch into the fourth extruder 1D to prepare the sticky layer, and at the same time, put it into the first extruder 1A, the second extruder 1B, and the third extruder 1C according to the ratio of the surface layer, the middle layer, and the bottom layer according to the base material layer formula;

[0063] S3: The substrate layer and the adhesive layer are extruded through the substrate layer die 3 and the adhesive layer die 5 respectively, and co-extruded through the pressure roller 6 and the forming roller 7 to form a preliminary film;

[0064] S4: the initial film is trimmed by the trimming mechanism 9 and then measured by the thickness gauge 8;

[0065] S5: the initial film is corona-exposed by the corona device 10, coated with silicone oil by the silicon coating roller 11, and then cured by the curing box 12 to form a formed film;

[0066] S6: The visual inspection mechanism 13 captures the defects of the formed film and then rewinds it through the reel 14.

[0067] In S1, a two-stage underwater granulation system is used, including a first granulator and a second granulator. The first granulator is preferably a co-rotating three-screw device with an aspect ratio greater than 68, and the granulation temperature is 120-160 degrees. The material is discharged from the discharge port of the first granulator and enters the double-cone feeder. The side-force feeding method is adopted, and the discharge port of the double-cone feeder is vertically entered into the feed port of the second single-screw granulator at 90 degrees. The second granulator preferably adopts a "high compression ratio" machine with a screw diameter greater than 100mm and an aspect ratio greater than 48. The screw temperature is 80-100 degrees. The first granulator adopts natural exhaust in the first stage and vacuum in the second stage to treat volatiles. The second stage adopts natural exhaust to form. 0.5% of the fumed silica is mixed in the first granulator, and the remaining 0.5% is sprinkled on the formed particles as an anti-sticking release agent to prevent adhesion to obtain a sticky layer masterbatch.

[0068] In S2, the masterbatch obtained in S1 is added to the fourth extruder 1D and extruded into a film at a temperature of about 100-120 degrees.

[0069] The components of the substrate layer are respectively put into the corresponding ABC molds for extrusion into films, with a processing temperature of 230 degrees.

[0070] The distance between the substrate layer die head 3 and the contact surface of the forming roller 7 is 10-20 cm. By adjusting the screw speed and the roller speed, extrusion and compounding are carried out according to the ratio of 20% of the adhesive layer and 80% of the substrate. After passing through the cooling roller, a film with a thickness of 80um is made.

[0071] The width of the substrate layer die 3 is 1600mm, the substrate layer die 3 is preferably a 1.0-1.2mm mold, the gap of the bonding layer die 5 is preferably 0.6-0.8mm, the screw diameters of the first extruder 1A, the second extruder 1B, and the third extruder 1C are: 50mm / 80mm / 50mm, 1D has a diameter of 50mm, the casting cooling roller is preferably a mirror roller with a surface roughness (Ra) of 0.02um, and the roller on the side contacting the rubber layer is treated with "plasma anti-sticking and anti-slip" and is rolled up.

[0072] In S5, an air floating roller is used inside the curing box 12 for non-contact conveying of the film. During thermal curing or ultraviolet curing, the heat source or light source comes from above, and the adhesive layer is bound to contact the traction roller. Especially during high-temperature curing, the film will become sticky. The air floating roller method used evenly punches (1mm) holes on the roller surface, and the film is floated by compressed air, avoiding the "roller sticking phenomenon" in this link.

[0073] Adhesive Example 1: 30 components of SEBS, 40 components of tackifying resin, 10 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0074] Adhesive Example 2: 30 components of SEBS, 50 components of tackifying resin, 10 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0075] Adhesive Example 3: 30 components of SEBS, 60 components of tackifying resin, 10 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0076] Adhesive Example 4: 30 components of SEBS, 40 components of tackifying resin, 15 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0077] Adhesive Example 5: 30 components of SEBS, 50 components of tackifying resin, 15 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0078] Adhesive Example 6: 30 components of SEBS, 60 components of tackifying resin, 15 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0079] Adhesive Example 7: 30 components of SEBS, 40 components of tackifying resin, 20 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0080] Adhesive Example 8: 30 components of SEBS, 50 components of tackifying resin, 20 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0081] Adhesive Example 9: 30 components of SEBS, 60 components of tackifying resin, 20 components of white oil, 1 component of fumed silica, 0.5 components of antioxidant 1010;

[0082] Different adhesive layer masterbatches were prepared according to adhesive examples 1-9, and self-adhesive films were prepared by using the adhesive layer masterbatches according to the production method, and the formed films were tested.

[0083] Test results:

[0084] 1. Expanding force

[0085] The surface protection film was respectively wound on a PP tube core with an inner diameter of 3 inches to make a film roll with a width of 50 mm. According to JI SZ0237, the surface protection film was unwound from the film roll at an unwinding speed of 20 m / min, and the high-speed unwinding force was measured. The test value is the unfolding force;

[0086] Internal standard: The evaluation of the unfolding force within 3N / 50mm is A, the evaluation of more than 3N / mm but not more than 7N / 50mm is B, and the evaluation of more than 7N / 50mm is C;

[0087] 2. Initial adhesion

[0088] The surface protective film was laminated 72 hours after it was made. The ultra-mirror steel plate was used as the test plate. The surface roughness Ra was less than 0.02um. It was cut into 15cmX5cm test plates. The lamination conditions were at room temperature of 23 degrees and relative humidity of 50%. A 2kg rubber roller was used to laminate at a speed of 300mm / min. After being placed in this state for 30 minutes, the 180-degree peel strength of 25mm width was tested at a speed of 300mm / min according to JIS Z0237. The peel strength at this time is taken as the initial adhesion;

[0089] 3. Adhesion after high temperature

[0090] The surface protective film was bonded 72 hours after it was made. The ultra-mirror steel plate was used as the test plate. The surface roughness Ra was less than 0.02um. It was cut into 15cmX5cm test plates. The bonding conditions were at room temperature of 23 degrees and relative humidity of 50%. A 2kg rubber roller was used to bond at a speed of 300mm / min. After being placed in this state for 30 minutes, the bonded product was placed at a temperature of 50 degrees for 30 minutes for baking. After baking, it was taken out and left to stand for 30 minutes. Then, the 180-degree peel strength of 25mm width was tested at a speed of 300mm / min according to JIS Z0237. The peel strength at this time is used as the adhesion after high temperature.

[0091] 4. Layered testing (internal testing method);

[0092] The tape was attached to the smooth steel plate and the 180-degree peel strength of 25 mm width was tested at a speed of 300 mm / min according to JIS Z0237 to observe whether there was debonding / delamination on the surface.

[0093] 5. Pollution

[0094] After peeling off the sample film from the adhered object, spotlight the adhered surface in a dark room and observe the surface contamination status with the naked eye. The status is determined as follows: no contamination A, slight contamination B, contamination C

[0095] 6. Film curling degree test

[0096] After bonding, the product was cut into the size of A4 paper with a blade. At room temperature and after high temperature, the bonded product was placed on the glass table. After standing for 30 minutes, the distance from the edge to the table was measured. The judgment results were: A for warping less than 1cm, B for warping greater than 1cm but less than 3cm, and C for warping greater than 3cm.

[0097] The test results are:

[0098] The test data of room temperature peeling force (N / 25mm) of adhesion examples 1-9 are 11.5N / 25mm; 13N / 25mm; 13.5N / 25mm; 12.7N / 25mm; 13.7N / 25mm; 14.2N / 25mm; 13.7N / 25mm; 14.1N / 25mm; 14.8N / 25mm;

[0099] High temperature peeling force (N / 25mm) The test data of adhesive examples 1-9 are 14N / 25mm; 14.2N / 25mm; 14.7N / 25mm; 13.8N / 25mm; 14.1N / 25mm; 14.6N / 25mm; 14.2N / 25mm; 14.3N / 25mm; 15.2N / 25mm;

[0100] Adhesive examples 1-9 can be torn completely;

[0101] The contamination of sticky examples 1-9 is all A;

[0102] The curl test results of adhesive examples 2, 3, 4, and 5 were grade A, and the curl test results of adhesive examples 1, 6, 7, 8, and 9 were grade B;

[0103] The unwinding force test results of adhesive samples 1, 2, 4, and 6 are grade A, and the unwinding force test results of adhesive samples 3, 5, 7, 8, and 9 are grade B.

[0104] After taking the cost into consideration, the internal addition of 10% is already the cost limit of the film. According to customer usage habits, Class B unwinding is also acceptable. If better unwinding effect or higher viscosity products are required, the surface EXfo la additive can be removed, and then the surface can be coated with silicone oil and then cured to achieve release. The silicone-coated and cured parts configured in the equipment can meet production needs.

[0105] According to the data obtained from the test, there is no residue or curling in Adhesive Example 2 and Adhesive Example 4, and the cleanliness of the formula is more preferred. Compared with Adhesive Example 2, Adhesive Example 4 has a smaller viscosity increase after high temperature, a smaller viscosity change after bonding the product, and is safer to use. Based on the above conditions, Adhesive Example 4 is preferred.

[0106] The above description is only the preferred embodiment of the present invention, which does not limit the protection scope of the present invention. For those skilled in the art, the present invention can be modified and varied in various ways. Within the spirit and principle of the present invention, any change, modification, replacement, integration and parameter change of these embodiments by conventional substitution or capable of achieving the same function without departing from the principle and spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment, characterized in that: The self-adhesive film comprises a substrate layer and an adhesive layer, wherein the substrate layer comprises a surface layer, a middle layer and a bottom layer; The formula of the surface layer is LDPE 90% + Exfola 10%; The formula of the middle layer is LLDPE 70% + LDPE 20% + edge material 10%; The formula of the bottom layer is LDPE95%+SEBS5%; The formula of the adhesive layer is: 30 components of SEBS, 40-60 components of tackifying resin, 10-20 components of white oil, 1 component of fumed silica, and 0.5 components of antioxidant 1010.

2. A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment as claimed in claim 1, characterized in that: The production equipment comprises an extruder (1), a weighing mechanism (2), a substrate layer die (3), a distributor (4), a bonding layer die (5), a pressing roller (6), a forming roller (7), a thickness gauge (8), a trimming mechanism (9), a corona mechanism (10), a silicon coating roller (11), a curing box (12), a visual inspection mechanism (13), and a winding roller (14); The number of the extruders (1) is four, and the number of the distributor (4) is one, wherein the discharge ends of three of the extruders (1) are connected to the substrate layer die (3) through one of the distributors (4), and the discharge end of another extruder (1) is directly connected to the adhesive layer die (5); The outputs of the substrate layer die (3) and the adhesive layer die (5) are co-extruded into a primary film through a pressing roller (6) and a molding roller (7); the primary film is trimmed by a trimming mechanism (9) and then measured by a thickness gauge (8); the primary film is coronaed by a corona mechanism (10) and then coated with silicone oil by a silicon coating roller (11) and then cured by a curing box (12) to form a formed film; the visual inspection mechanism (13) captures defects on the formed film and then rewinds it through a rewinding roller (14).

3. A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment as claimed in claim 2, characterized in that: The extruders (1) are respectively a first extruder (1A), a second extruder (1B), a third extruder (1C), and a fourth extruder (1D), wherein the first extruder (1A), the second extruder (1B), and the third extruder (1C) are respectively used to extrude the surface layer, the middle layer, and the bottom layer of the self-adhesive film substrate layer, and the fourth extruder (1D) is used to extrude the adhesive layer of the self-adhesive film.

4. A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment as claimed in claim 3, characterized in that: The production method comprises the following steps: S1: Prepare the adhesive layer masterbatch in advance according to the adhesive layer formula; S2: putting the tack layer masterbatch into the fourth extruder (1D) to prepare the tack layer, and at the same time, according to the formula of the substrate layer, the surface layer, the middle layer, and the bottom layer are respectively put into the first extruder (1A), the second extruder (1B), and the third extruder (1C); S3: The substrate layer and the adhesive layer are extruded through a substrate layer die (3) and an adhesive layer die (5) respectively, and co-extruded through a pressure roller (6) and a molding roller (7) to form a preliminary film; S4: the initial film is trimmed by a trimming mechanism (9) and then measured for thickness by a thickness gauge (8); S5: When a better release effect is required, the initial film can be coronaed by a corona device (10), coated with silicone oil by a silicon coating roller (11), and then cured by a curing box (12) to form a surface release self-adhesive film; S6: The visual inspection mechanism (13) captures defects on the formed film and then reels it through the reel (14), thereby facilitating the control of product quality.

5. A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment as claimed in claim 4, characterized in that: In the S1, a two-stage underwater granulation system is used, including a first granulator and a second granulator. The first granulator is preferably a co-rotating three-screw device with an aspect ratio greater than 68, and the granulation temperature is 120-160 degrees. The material is discharged from the discharge port of the first granulator and enters the double-cone feeder. The side force feeding method is adopted, and the discharge port of the double-cone feeder is vertically entered into the feed port of the second single-screw granulator at 90 degrees. The second granulator is preferably a "high compression ratio" machine with a screw diameter greater than 100mm and an aspect ratio greater than 48, and the screw temperature is 80-100 degrees. The first granulator adopts the first stage natural exhaust and the second stage vacuuming method to treat volatiles. The second extruder adopts natural exhaust method to form. 0.5% of the fumed silica is mixed in the first granulator, and the remaining 0.5% is sprinkled on the formed particles as an anti-sticking release agent to prevent adhesion, thereby obtaining a sticky layer masterbatch.

6. A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment as claimed in claim 5, characterized in that: In S2, the masterbatch obtained from S1 is added to the fourth extruder (1D) and extruded into a film at a temperature of about 100-120 degrees.

7. A double-sided composite ultra-high-viscosity self-adhesive film, production process and equipment as claimed in claim 6, characterized in that: The components of the substrate layer are respectively put into the corresponding ABC molds for extrusion into films. The density range of the substrate LDPE and LLDPE is preferably 0.920-0.930 g / cm3, MI is 1-6 g / 10min, and the processing temperature is 230-245 degrees.

8. A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment as claimed in claim 7, characterized in that: The distance between the contact surface of the substrate layer die head (3) and the forming roller (7) is 10-20 cm. By adjusting the screw speed and the roller pulling speed, extrusion compounding is carried out at a ratio of 20% for the adhesive layer and 80% for the substrate, and a film with a thickness of 80 μm is produced after passing through the forming roller.

9. A double-sided composite ultra-high viscosity self-adhesive film, production process and equipment as claimed in claim 8, characterized in that: The width of the substrate layer die (3) is 1600mm, and the substrate layer die (3) is preferably a "hanger-type" die with a die gap of 1.0-1.2mm. The gap of the adhesive layer die (5) is preferably a "hanger-type" die with a gap of 0.6-0.8mm. The fourth extruder (1D) is preferably equipped with a melt pump to provide stable delivery pressure to the die for film discharge. The screw diameters of the first extruder (1A), the second extruder (1B), and the third extruder (1C) are: 50mm / 80mm / 50mm, and the diameter of (1D) is 50mm. The casting cooling roller is preferably a mirror roller with a surface roughness (Ra) of 0.02um. The other rollers that contact the adhesive layer during the traction process are treated with "plasma anti-sticking and anti-slip" and are rolled up.

10. A double-sided composite ultra-high-viscosity self-adhesive film, production process and equipment as claimed in claim 9, characterized in that: In the curing box (12) in S5, air floating rollers are used inside to transport the film in a non-contact manner.

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