A fixing film with heat shrinking effect and its preparation method

Abstract

This invention relates to a fixing film with heat-shrinkable properties and its preparation method. The fixing film has a multi-layer structure, comprising, from the inside out: a substrate, a base coating layer, a silicone layer, a top coating layer, and a heat-shrinkable layer. The heat-shrinkable layer comprises the following components in parts by weight: 30-50 parts PFA resin, 40-50 parts polyethylene, 10-30 parts polyurethane, 5-10 parts polytetrafluoroethylene, 5-8 parts modified silica particles, and 1-5 parts additives. The modified silica particles are hydroxylated silica, partially grafted with perfluorinated acid and partially grafted with unsaturated carboxylic acids, and then copolymerized with acrylate. The release liner sleeve with heat-shrinkable properties prepared by this invention not only has good mechanical properties but also shrinks uniformly after heating, avoiding the formation of defects such as bubbles and wrinkles, resulting in a smoother surface. It also improves production efficiency and overcomes the shortcomings of existing technologies.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a fixing film with heat shrinkage effect and its preparation method. Background Technology

[0002] The fixing film, also known as the fixing roller, is a key component in office equipment such as copiers or printers for fixing toner images that have been copied or printed.

[0003] During the copying or printing process, the image formed by toner is transferred to the paper surface, and the paper is then fed into the fixing assembly. The upper roller of the fixing assembly uses the high temperature released by its built-in heating lamp to transfer heat energy to the toner image on the paper; simultaneously, the lower roller applies pressure to the upper roller, causing the toner image to melt rapidly under the combined action of high temperature and pressure, and adhere tightly to the paper fibers. Then, with the coordinated rotation of the upper and lower rollers, the paper is conveyed to the copier's output tray, completing the fixing process.

[0004] Fixing films typically consist of a substrate, a silicone layer, a coating layer, and a sleeve. The sleeve is usually made of fluoropolymer resin, i.e., a fluoropolymer sleeve. Compared to polyvinyl chloride and polyethylene, this type of material has a higher operating temperature, better mechanical strength, and better non-stick properties, and its density is better, preventing water vapor penetration and corrosive gas corrosion. However, current technology requires an adhesive to be added between the coating layer and the sleeve layer to achieve a tighter bond. Adding an adhesive not only complicates the manufacturing process and makes the subsequent drying process more cumbersome, but it also easily introduces air bubbles, leading to a loose, wrinkled, and uneven surface on the fixing film. This severely affects the results of subsequent printing processes and presents significant defects that no longer meet current consumer demands.

[0005] In conclusion, there is an urgent need to develop a new technical solution to address the problems existing in the current technology. Summary of the Invention

[0006] Based on this, the present invention provides a fixing film with heat shrinkage effect and its preparation method. The fixing film uses PFA resin, polyethylene, polyurethane and other materials as matrix resins, and modifies silica with perfluorinated acid, unsaturated carboxylic acid and acrylic acid to obtain a release layer sleeve with heat shrinkage effect. It not only has good mechanical properties, but also can shrink uniformly after heating, avoiding the formation of defects such as bubbles and wrinkles, and has a smoother surface. It also improves production efficiency and overcomes the shortcomings of the prior art.

[0007] One object of the present invention is to provide a fixing film with heat shrinking effect, the fixing film having a multilayer structure, comprising, from the inside out: a substrate, a base coating layer, a silicone layer, a surface coating layer and a heat shrinking layer;

[0008] The heat-shrinkable layer comprises the following components in parts by weight:

[0009]

[0010]

[0011] The modified silica particles are hydroxylated silica, partially grafted with perfluorinated acid and partially grafted with unsaturated carboxylic acids, and then copolymerized with acrylate.

[0012] Furthermore, the perfluoroacid is selected from one or more of perfluorotridecanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, or mixtures thereof.

[0013] Furthermore, the unsaturated carboxylic acid is selected from one or more of acrylic acid and methacrylic acid.

[0014] Furthermore, the acrylate is selected from one or more of butyl acrylate, octyl acrylate, and dodecyl acrylate.

[0015] Furthermore, the additive is selected from one or more of the following: catalyst, initiator, crosslinking agent, coupling agent, lubricant, antioxidant, film-forming aid, and dispersant.

[0016] Furthermore, the substrate is preferably a polyimide substrate, the base coating and the top coating are preferably fluorine-containing coatings, and the silicone layer is preferably a thermally conductive silicone rubber elastomer.

[0017] Another object of the present invention is to provide a method for preparing the above-mentioned fixing film with heat shrinkage effect, wherein the method for preparing the fixing film with heat shrinkage effect includes the following steps:

[0018] S1. Blend perfluorinated acid and unsaturated acid, add solvent, and stir to form a blend;

[0019] S2. Hydroxylated silica is immersed in the blend and ultrasonically heated to react and form an intermediate product.

[0020] S3. The intermediate product is subjected to free radical polymerization with acrylate to form modified silica particles;

[0021] S4. The modified silica particles are mixed with other components and extruded to obtain a heat-shrinkable sleeve.

[0022] S5. Insert the core containing the substrate, primer, silicone layer and top coating into the heat shrinkable sleeve to obtain the product.

[0023] Furthermore, the molar ratio of the perfluoroacid to the unsaturated carboxylic acid is 1:(1-3).

[0024] Furthermore, the temperature of the ultrasonic heating is 60-90℃.

[0025] Furthermore, the mass ratio of the intermediate product to the acrylate is (0.1-5):1.

[0026] Furthermore, the free radical polymerization temperature is 50-100℃.

[0027] The beneficial effects of this invention are as follows:

[0028] This invention uses PFA resin, polyethylene, polyurethane, and polytetrafluoroethylene as matrix materials, compounded with modified silica to obtain a heat-shrinkable layer. Specifically, the modified silica is first reacted with hydroxylated silica, perfluoroheptanoic acid, and acrylic acid to introduce perfluoroalkyl chains and unsaturated double bonds onto the silica surface. Then, it undergoes free radical polymerization with alkyl acrylates to further introduce polymer structures. The resulting modified silica improves compatibility with fluorinated resins, polyethylene, polyurethane, and other materials, allowing for more uniform distribution within the system and more stable bonding with the resin to form a uniform network structure, thus enhancing mechanical properties. Furthermore, it further improves stability and uniformity during shrinkage, which is beneficial for increasing the density, thermal conductivity, and gloss of the sleeve. In summary, this invention eliminates the need for adhesives on the outer surface of the coating, simplifying the preparation process, improving production efficiency, effectively avoiding bubbles and wrinkles, improving various properties of the fixing film, and solving problems existing in the prior art. Detailed Implementation

[0029] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0030] The PFA resin used in this embodiment of the invention is DuPont 451HP.

[0031] The polyethylene used in this embodiment of the invention is HD5301AA.

[0032] The polyurethane in this embodiment of the invention is a thermoplastic polyurethane containing polymerizable unsaturated groups, M n =5000-12000.

[0033] The preparation method of hydroxylated silica in this embodiment of the invention includes the following steps: immersing silica in a mixture of concentrated sulfuric acid and hydrogen peroxide (mass concentration 30%) with a volume ratio of 70:30, heating at 70°C for 1 hour, and then washing and drying to obtain hydroxylated silica.

[0034] In the embodiments of this invention, "parts" refers to parts by mass.

[0035] Example 1

[0036] A fixing film with heat shrinking effect, the fixing film having a multi-layer structure, comprising, from the inside out: a substrate, a base coating layer, a silicone layer, a surface coating layer and a heat shrinking layer;

[0037] The heat-shrinkable layer comprises the following components in parts by weight:

[0038]

[0039] The method for preparing the fixing film with heat shrinkage effect includes the following steps:

[0040] S1. Using dichloromethane as a solvent, perfluoroheptanoic acid and acrylic acid in a molar ratio of 1:1 are blended and stirred to form a blend.

[0041] S2. The hydroxylated silica was soaked in the blend (the mass ratio of hydroxylated silica to perfluoroheptanoic acid was 2:1), ultrasonically reacted at 70°C for 10 h, and then filtered, washed and dried to obtain the intermediate product.

[0042] S3. Using water as a solvent, the intermediate product, butyl acrylate, sodium dodecyl sulfate and potassium persulfate in a mass ratio of 8:2:0.5:0.1 were mixed and reacted at 85°C for 5 hours under a nitrogen atmosphere. After filtration, washing and drying, modified silica particles were obtained.

[0043] S4. According to the above mass proportions, the modified silica particles and other components are mixed and stirred evenly and added to an extruder. The mixture is extruded at 200-300℃ and then blown up (blow-up ratio is 2) to obtain a heat-shrinkable sleeve.

[0044] S5. Insert the core containing the substrate, primer, silicone layer and top coating into the heat shrinkable sleeve, and heat at 300-310℃ for 4 minutes to obtain the product.

[0045] Example 2

[0046] A fixing film with heat shrinking effect, the fixing film having a multi-layer structure, comprising, from the inside out: a substrate, a base coating layer, a silicone layer, a surface coating layer and a heat shrinking layer;

[0047] The heat-shrinkable layer comprises the following components in parts by weight:

[0048]

[0049] The method for preparing the fixing film with heat shrinkage effect includes the following steps:

[0050] S1. Using dichloromethane as a solvent, perfluoroheptanoic acid and acrylic acid in a molar ratio of 1:1 are blended and stirred to form a blend.

[0051] S2. The hydroxylated silica was soaked in the blend (the mass ratio of hydroxylated silica to perfluoroheptanoic acid was 2:1), ultrasonically reacted at 70°C for 10 h, and then filtered, washed and dried to obtain the intermediate product.

[0052] S3. Using water as a solvent, the intermediate product, butyl acrylate, sodium dodecyl sulfate and potassium persulfate in a mass ratio of 8:2:0.5:0.1 were mixed and reacted at 85°C for 5 hours under a nitrogen atmosphere. After filtration, washing and drying, modified silica particles were obtained.

[0053] S4. According to the above mass proportions, the modified silica particles and other components are mixed and stirred evenly and added to an extruder. The mixture is extruded at 200-300℃ and then blown up (blow-up ratio is 2) to obtain a heat-shrinkable sleeve.

[0054] S5. Insert the core containing the substrate, primer, silicone layer and top coating into the heat shrinkable sleeve, and heat at 300-310℃ for 4 minutes to obtain the product.

[0055] Example 3

[0056] A fixing film with heat shrinking effect, the fixing film having a multi-layer structure, comprising, from the inside out: a substrate, a base coating layer, a silicone layer, a surface coating layer and a heat shrinking layer;

[0057] The heat-shrinkable layer comprises the following components in parts by weight:

[0058]

[0059] The method for preparing the fixing film with heat shrinkage effect includes the following steps:

[0060] S1. Using dichloromethane as a solvent, perfluoroheptanoic acid and acrylic acid in a molar ratio of 1:1 are blended and stirred to form a blend.

[0061] S2. The hydroxylated silica was soaked in the blend (the mass ratio of hydroxylated silica to perfluoroheptanoic acid was 2:1), ultrasonically reacted at 70°C for 10 h, and then filtered, washed and dried to obtain the intermediate product.

[0062] S3. Using water as a solvent, the intermediate product, butyl acrylate, sodium dodecyl sulfate and potassium persulfate in a mass ratio of 8:2:0.5:0.1 were mixed and reacted at 85°C for 5 hours under a nitrogen atmosphere. After filtration, washing and drying, modified silica particles were obtained.

[0063] S4. According to the above mass proportions, the modified silica particles and other components are mixed and stirred evenly and added to an extruder. The mixture is extruded at 200-300℃ and then blown up (blow-up ratio is 2) to obtain a heat-shrinkable sleeve.

[0064] S5. Insert the core containing the substrate, primer, silicone layer and top coating into the heat shrinkable sleeve, and heat at 300-310℃ for 4 minutes to obtain the product.

[0065] Comparative Example 1

[0066] A fixing film with heat shrinking effect. The difference between this comparative example and Example 1 is that the modified silica particles are replaced with a mixture of hydroxylated silica and perfluoroheptanoic acid in a mass ratio of 2:1. Other materials and preparation methods are the same as in Example 1.

[0067] Comparative Example 2

[0068] A fixing film with heat shrinking effect. The difference between this comparative example and Example 1 is that in step S1, perfluoroheptanoic acid is completely replaced with acrylic acid, while other materials and preparation methods are the same as in Example 1.

[0069] Test case

[0070] The performance of the fixing films with heat shrinkage effect prepared in Examples 1-3 and Comparative Examples 1-2 was tested.

[0071] Test method:

[0072] Mechanical properties: Tested in accordance with GB / T 13022.

[0073] Surface smoothness: Observe whether there are bubbles and wrinkles on the surface of the fixing film samples prepared in the examples and comparative examples; then conduct printing tests to check whether the printed samples are uniform and clear.

[0074] The test results are shown in Table 1.

[0075] Table 1 Performance Test Results

[0076]

[0077] Table 1 shows that the fixing films with heat-shrinkable effects prepared in Examples 1-3 of this invention have good mechanical properties, while avoiding defects such as bubbles and wrinkles, and exhibit excellent fixing performance. In contrast, Comparative Examples 1-2, by replacing modified silica with a physical mixture of unmodified silica and perfluorinated acid or acrylic acid-modified silica, reduced the compatibility between components, making it difficult to form an ideal synergistic effect. This resulted in decreased uniformity and stability of the cross-linked structure, leading to a decline in the material's mechanical properties, uneven heat-shrinkage, and defects such as bubbles in the fixing film, significantly reducing the clarity of the printed samples. In summary, this invention overcomes the problems existing in the prior art and has good application prospects.

[0078] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0079] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A fixing film with heat-shrinking effect, characterized in that, The fixing film has a multi-layer structure, which includes, from the inside out: a substrate, a base coating layer, a silicone layer, a top coating layer, and a heat-shrinkable layer; The heat-shrinkable layer comprises the following components in parts by weight: The modified silica particles are hydroxylated silica, partially grafted with perfluorinated acid and partially grafted with unsaturated carboxylic acids, and then copolymerized with acrylate.

2. The fixing film with heat-shrinking effect according to claim 1, characterized in that, The perfluoroacid is selected from one or more of perfluorotridecanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, or mixtures thereof.

3. The fixing film with heat-shrinking effect according to claim 1, characterized in that, The unsaturated carboxylic acid is selected from one or more of acrylic acid and methacrylic acid.

4. The fixing film with heat-shrinking effect according to claim 1, characterized in that, The acrylate is selected from one or more of butyl acrylate, octyl acrylate, and dodecyl acrylate.

5. The method for preparing the fixing film with heat-shrinking effect according to any one of claims 1-4, characterized in that, The method for preparing the fixing film with heat shrinkage effect includes the following steps: S1. Blend perfluorinated acid and unsaturated acid, add solvent, and stir to form a blend; S2. Hydroxylated silica is immersed in the blend and ultrasonically heated to react and form an intermediate product. S3. The intermediate product is subjected to free radical polymerization with acrylate to form modified silica particles; S4. The modified silica particles are mixed with other components and extruded to obtain a heat-shrinkable sleeve. S5. Insert the core containing the substrate, primer, silicone layer and top coating into the heat shrinkable sleeve to obtain the product.

6. The method for preparing a fixing film with heat-shrinking effect according to claim 5, characterized in that, The molar ratio of the perfluorinated acid to the unsaturated carboxylic acid is 1:(1-3).

7. The method for preparing a fixing film with heat-shrinking effect according to claim 5, characterized in that, The ultrasonic heating temperature is 60-90℃.

8. The method for preparing a fixing film with heat-shrinking effect according to claim 5, characterized in that, The mass ratio of the intermediate product to the acrylate is (0.1-5):

1.

9. The method for preparing a fixing film with heat-shrinking effect according to claim 5, characterized in that, The free radical polymerization temperature is 50-100℃.

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