Leather release paper production device and production method of leather release paper

Abstract

The present invention provides a leather release paper production device for producing leather release paper. The leather release paper production device includes a concave embossing roller, a first coating roller abutted against the concave embossing roller, a first material box for the first coating roller to pick up an ultra-low surface tension coating, a second coating roller abutted against the concave embossing roller, a second material box for the second coating roller to pick up an electron beam curable release paper coating, and a curing device facing the concave embossing roller to cure the ultra-low surface tension coating on the concave embossing roller. The first coating roller and the second coating roller are arranged at a radial interval, and the curing device is arranged radially between the first coating roller and the second coating roller. In the leather release paper production device of the present invention, an ultra-low surface tension coating is applied before applying the electron beam curable release paper coating and cured by the curing device, which can reduce the surface tension of the concave embossing roller and the surface tension of the leather release paper.

Description

Technical Field

[0001] The present invention relates to a leather release paper production device and a production method of leather release paper. Background Art

[0002] The development of leather release paper began in the 1960s, and its development has roughly gone through three stages of technological transformation: direct silicone coating, primer plus release layer coating, and thermoplastic resin coating. In the early days, most leather release papers used direct silicone coating of release agents as the release layer. After drying and curing, patterns were then pressed. The leather release paper produced by this technology had a small number of reuse times, generally about 5 times, and the patterns were not clear enough. Therefore, it was phased out in the 1970s. Primer plus release layer coating is the main production method for silicone-based leather release paper. The specific method is to first coat a primer on the base paper to improve the smoothness of the base paper and the ability to resist the penetration of silicone-based coatings. After the primer is cured, a release layer is then coated and cured. The curing methods include thermal curing, ultraviolet curing, electron beam (EB) curing, etc. Compared with the early leather release papers, the advantages of this type of leather release paper are that the paper surface is more uniform, the patterns are clearer, and the number of times of paper reuse is greatly increased, and it can be used for the production of both PVC leather and PU leather at the same time.

[0003] Using radiation-curable release materials as the release layer of leather release paper can overcome the disadvantages of thermosetting resin leather release paper, that is, phenomena such as curling, wrinkling, and pinholes of leather release paper caused by high-temperature treatment. The main mechanism of radiation curing is as follows: after the radiation-curable coating is irradiated by ultraviolet light or electron beam, the photoinitiator absorbs the radiation energy of ultraviolet light or electron beam and is activated. The outer-layer electrons of its molecules jump, and active centers are generated in a very short time. The active centers act on the unsaturated groups in the resin, causing the double bonds in the photo-curable resin and active diluent molecules to break, and continuous polymerization reactions occur, thereby crosslinking with each other to form a film.

[0004] The peeling force of electron beam-cured leather release paper is affected by its surface tension. The lower the surface tension of the release paper, the lower the peeling force and the higher the number of use times, reducing the production cost of leather.

[0005] Moreover, the surface tension of the release paper is also affected by the surface tension of the embossing material. When the surface tension of the embossing material is relatively low, the surface tension of the release paper is also relatively low. In the experiment, we found that the release paper pressed by the patterned polypropylene film has a lower surface tension than the release paper pressed by the patterned PET film. Because the surface tension (or polarity) of the PET film is relatively high, more polar groups of the uncured release coating are attracted, resulting in a higher surface tension of the release coating after curing.

[0006] However, plastic materials are not suitable for use as embossing rollers because they cannot withstand long-term electron beam irradiation, and the materials used for embossing rollers must be metal. The surface tension of metal is usually high, so the surface tension of the produced electron beam release paper is also high.

[0007] In view of this, it is necessary to improve the existing leather release paper production device to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to provide a leather release paper production device to solve the problems of high surface tension and low number of uses of the existing leather release paper.

[0009] To achieve the above purpose, the present invention provides a leather release paper production device for producing leather release paper. The leather release paper production device includes a concave embossing roller, a first coating roller that abuts against the concave embossing roller, a first material box for supplying the first coating roller to pick up an ultra-low surface tension coating, a second coating roller that abuts against the concave embossing roller, a second material box for supplying the second coating roller to pick up an electron beam curable release paper coating, and a curing device that faces the concave embossing roller to cure the coating on the concave embossing roller. The first coating roller and the second coating roller are arranged at a radial interval, and the curing device is arranged radially between the first coating roller and the second coating roller.

[0010] As a further improvement of the present invention, in the vertical direction, the first coating roller and the second coating roller abut against the lower side of the concave embossing roller.

[0011] As a further improvement of the present invention, the leather release paper production device further includes an electron beam dryer arranged on the upper side of the concave embossing roller.

[0012] As a further improvement of the present invention, the curing device is one or more of a thermal curing device, a UV light curing device, and an electron beam curing device.

[0013] As a further improvement of the present invention, the leather release paper production device further includes turning rollers arranged horizontally on both sides of the concave embossing roller.

[0014] As a further improvement of the present invention, the ultra-low surface tension coating contains a silicone material, and the silicone material is one or more of a high molecular silicone resin, a low molecular silicone oil, a vinyl silicone oil, a hydrogen-containing silicone oil, and an acrylate-modified silicone oil.

[0015] As a further improvement of the present invention, the ultra-low surface tension coating further contains a diluent, and the diluent is one or more of isobornyl acrylate, lauryl acrylate, isooctyl acrylate, toluene, and xylene.

[0016] As a further improvement of the present invention, the components and mass percentages of the electron beam curable release paper coating are as follows: polyurethane acrylate resin 40 - 80%; high functionality acrylate monomer 10 - 50%; release agent 5 - 10%.

[0017] The present invention also provides a method for producing leather release paper, and the method for producing leather release paper includes the following steps:

[0018] S1: Provide the leather release paper production device as described above;

[0019] S2: Prepare an ultra - low surface tension coating and place it in the first material box, prepare an electron beam curable release paper coating and place it in the second material box;

[0020] S3: Rotate the concave embossing roller, and the first coating roller coats the ultra - low surface tension coating in the first material box on the concave embossing roller;

[0021] S4: Start the curing device to cure the ultra - low surface tension coating coated on the concave embossing roller;

[0022] S5: The concave embossing roller coated with the cured ultra - low surface tension coating abuts against the second coating roller, and the second coating roller coats the electron beam curable release paper coating on the concave embossing roller;

[0023] S6: The concave embossing roller rotates further until it abuts against the leather release paper base paper, and the pattern on the concave embossing roller is directly copied onto the leather release paper.

[0024] As a further improvement of the present invention, the leather release paper production device further includes an electron beam dryer disposed above the concave embossing roller, and after step S6 of the method for producing leather release paper, it further includes: before the leather release paper and the concave embossing roller are separated, using the electron beam dryer to cure the electron beam curable release paper coating on the concave embossing roller.

[0025] The beneficial effects of the present invention are: The leather release paper production device and the method for producing leather release paper of the present invention coat an ultra - low surface tension coating and cure it through a curing device before coating the electron beam curable release paper coating, so as to reduce the surface tension of the concave embossing roller, and further reduce the surface tension of the produced leather release paper, increase the number of uses of the leather release paper and reduce costs. Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of the leather release production device of the present invention;

[0027] Figure 2 is a flowchart of the method for producing leather release paper of the present invention. Detailed implementation manners

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] As Figure 1 shown, the leather release paper production device 100 of the present invention is used to produce leather release paper 200.

[0032] The leather release paper production device 100 includes a concave embossing roller 1, a first coating roller 2 that abuts against the concave embossing roller 1, a first material box 3 for the first coating roller 2 to pick up an ultra-low surface tension coating, a second coating roller 4 that abuts against the concave embossing roller 1, a second material box 5 for the second coating roller 4 to pick up an electron beam curable release paper coating, a curing device 6 facing the concave embossing roller 1 to cure the coating on the concave embossing roller 1, turning rollers 7 arranged horizontally on both sides of the concave embossing roller 1, and an electron beam dryer 8 arranged above the concave embossing roller 1.

[0033] Vertically, the first coating roller 2 and the second coating roller 4 abut against the lower side of the concave embossing roller 1.

[0034] The first coating roller 2 and the second coating roller 4 are arranged at a radial interval, and the curing device 6 is arranged radially between the first coating roller 2 and the second coating roller 4.

[0035] In this embodiment, the concave embossing roller 1 abuts against the first coating roller 2 first to coat the ultra-low surface tension coating on the concave embossing roller 1, and then the curing device 6 cures the ultra-low surface tension coating on the concave embossing roller 1, and then passes through the second coating roller 4 to coat the electron beam curable release paper coating.

[0036] The curing device 6 is one or more of a thermal curing device, a UV light curing device, and an electron beam curing device. The curing device 6 needs to be selected according to the type of the ultra-low surface tension coating to expect a better curing effect.

[0037] The ultra-low surface tension coating contains a silicone material and a diluent, and the silicone material is one or more of a high molecular silicone resin, a low molecular silicone oil, a vinyl silicone oil, a hydrogen-containing silicone oil, and an acrylate-modified silicone oil.

[0038] The ultra-low surface tension coating can effectively reduce the surface tension of the concave embossing roller 1, and further reduce the surface tension of the leather release paper 200, so that the peeling force is reduced, the number of uses is increased, and the production cost of the leather release paper 200 is reduced. The ultra-low surface tension coating does not require an excellent curing speed, but after being coated on the concave embossing roller 1, the surface tension of the concave embossing roller 1 should reach below 26 dynes.

[0039] The diluent is one or more of isobornyl acrylate, lauryl acrylate, isooctyl acrylate, toluene, and xylene.

[0040] The viscosity of the ultra-low surface tension coating should be between 100 and 20,000 cps. If only the silicone material is selected, the viscosity may be too high, resulting in a coating thickness that may exceed 1 micron, increasing the curing difficulty. Therefore, an appropriate amount of diluent can be added to dilute the viscosity to below 500 cps, but it must be dried before coating the electron beam curable release paper coating to ensure that there will be no solvent that cannot be electron beam cured affecting the subsequent electron beam curable release paper coating.

[0041] The components and mass percentages of the electron beam curable release paper coating are as follows: polyurethane acrylate resin 40-80%; high-functional acrylate monomer 10-50%; release agent 5-10%.

[0042] As Figure 2 shown, the production method of the leather release paper includes the following steps:

[0043] S1: Provide the leather release paper production device 100 as described above;

[0044] S2: Prepare an ultra-low surface tension coating and place it in the first material box 3, prepare an electron beam curable release paper coating and place it in the second material box 5;

[0045] S3: Rotate the concave embossing roller 1, and the first coating roller 2 coats the ultra-low surface tension coating in the first material box 3 on the concave embossing roller 1;

[0046] S4: Start the curing device 6 to cure the ultra-low surface tension coating coated on the concave embossing roller 1;

[0047] S5: The concave embossing roller 1 coated with the cured ultra-low surface tension coating abuts against the second coating roller 4, and the second coating roller 4 coats the electron beam curable release paper coating on the concave embossing roller 1;

[0048] S6: The concave embossing roller 1 rotates further until it abuts against the leather release paper base paper. Before the leather release paper 200 is separated from the concave embossing roller 1, use the electron beam dryer 8 to cure the electron beam curable release paper coating on the concave embossing roller 1, and the pattern on the concave embossing roller 1 is directly copied onto the leather release paper 200.

[0049] In the present invention, an ultra-low surface tension coating less than one micron is coated on the concave embossing roller 1. The main function is to reduce the surface tension of the concave embossing roller 1. Part of the ultra-low surface tension coating will remain on the concave embossing roller 1, and the other part will be absorbed into the electron beam curable release paper coating, and no separate release layer will be formed.

[0050] Furthermore, the present invention provides the following three embodiments:

[0051] Embodiment 1:

[0052] S1: Provide the leather release paper production device 100 as described above;

[0053] S2: Put 5 kg of 107 silicone rubber and 95 kg of xylene into a reaction vessel, stir at room temperature (2000 ppm) for 30 minutes until uniform, and then pour it into the first material box 3, prepare an electron beam curable release paper coating and place it in the second material box 5;

[0054] S3: Rotate the concave embossing roller 1, and the first coating roller 2 coats the ultra-low surface tension coating in the first material box 3 on the concave embossing roller 1;

[0055] S4: Start the thermal curing device to blow hot air at 200 °C to cure the ultra-low surface tension coating coated on the concave embossing roller 1;

[0056] S5: The concave embossing roller 1 coated with the cured ultra-low surface tension coating abuts against the second coating roller 4, and the second coating roller 4 coats the electron beam curable release paper coating on the concave embossing roller 1;

[0057] S6: The concave embossing roller 1 further rotates until it abuts against the leather release paper base paper. Before the leather release paper 200 is separated from the concave embossing roller 1, use the electron beam dryer 8 to cure the electron beam curable release paper coating on the concave embossing roller 1, and directly copy the pattern on the concave embossing roller 1 onto the leather release paper 200, and then wind it up. The curing voltage is 500 kev, the curing dose is 30 kGy, and the linear velocity is 20 m / min.

[0058] Example 2:

[0059] S1: Provide the leather release paper production device 100 as described above;

[0060] S2: Put 80 kg of vinyl silicone oil with 500 cps and vi = 10%, 15 kg of IBOA (isobornyl acrylate), and 5 kg of photoinitiator 1173 into the reaction vessel, stir at room temperature (2000 ppm) for 30 min until uniform, and put it in the first material box 3 to prepare the electron beam curable release paper coating, and put it in the second material box 5;

[0061] S3: Rotate the concave embossing roller 1, and the first coating roller 2 coats the ultra-low surface tension coating in the first material box 3 on the concave embossing roller 1;

[0062] S4: Start the UV light curing device to cure the ultra-low surface tension coating coated on the concave embossing roller 1, and the curing energy is 1000 mj / cm 2 ;

[0063] S5: The concave embossing roller 1 coated with the cured ultra-low surface tension coating abuts against the second coating roller 4, and the second coating roller 4 coats the electron beam curable release paper coating on the concave embossing roller 1;

[0064] S6: The concave embossing roller 1 further rotates until it abuts against the leather release paper base paper. Before the leather release paper 200 is separated from the concave embossing roller 1, use the electron beam dryer 8 to cure the electron beam curable release paper coating on the concave embossing roller 1, and directly copy the pattern on the concave embossing roller 1 onto the leather release paper 200, and then wind it up. The curing voltage is 500 kev, the curing dose is 30 kGy, and the linear velocity is 20 m / min.

[0065] Example 3:

[0066] S1: providing the leather release paper production device 100 as described above;

[0067] S2: 80 kg of 500 cps, vi=10% vinyl silicone oil and 20 kg of 200 cps acrylate-modified silicone oil are put into a reaction container, stirred at room temperature (2000 ppm) for 30 min until uniform, and then put into the first material box 3 to prepare electron beam-cured release paper coating, which is then put into the second material box 5;

[0068] S3: rotating the concave embossing roller 1, so that the first coating roller 2 coats the ultra-low surface tension coating in the first material box 3 onto the concave embossing roller 1;

[0069] S4: starting the electron beam curing device, curing the ultra-low surface tension coating coated on the concave embossing roller 1 in a nitrogen atmosphere (oxygen concentration is less than 200 ppm), the irradiation energy is 90 KeV, and the irradiation dose is 80 kGy;

[0070] S5: the concave embossing roller 1 coated with the cured ultra-low surface tension coating is abutted against the second coating roller 4, and the second coating roller 4 coats the electron beam cured release paper coating on the concave embossing roller 1;

[0071] S6: The concave embossing roller 1 is further rotated until it is in contact with the leather release paper base paper. Before the leather release paper 200 and the concave embossing roller 1 are separated, the electron beam curing release paper coating on the concave embossing roller 1 is cured by using an electron beam dryer 8, and the pattern on the concave embossing roller 1 is directly copied to the leather release paper 200, and then rolled up. The curing voltage is 500kev, the curing dose is 30kGy, and the line speed is 20m / min.

[0072] Comparison example:

[0073] 50kg of Allnex resin EB9260, 20kg of EB230, 22kg of ethoxylated trimethylol triacrylate (EO3-TMPTA), 4kg of release agent Allnex EB350, and 4kg of Digo 2700 were put into a reaction container, stirred at room temperature (2000ppm) for 30min until uniform electron beam cured release paper coating was obtained, and the coating roller transferred the electron beam cured release paper coating to the embossing roller. Since the leather release paper base paper was close to the embossing roller, the pattern on the embossing roller was directly copied to the leather release paper 200. When the leather release paper 200 passed through the electron beam drying area, the electron beam cured release paper coating was quickly cured, with a curing voltage of 500kev, a curing dose of 30kGy, and a line speed of 20m / min, and then rolled up.

[0074] The leather release paper 200 obtained in Example 1, Example 2, Example 3 and the control example was tested for data and compared. The results are as follows:

[0075]

[0076] It can be seen that the number of uses of the leather release paper 200 obtained in Example 1, Example 2 and Example 3 with the process of coating the ultra-low surface tension coating increased is significantly higher than that of the leather release paper 200 obtained in the control group.

[0077] The leather release paper production device 100 and the production method of the leather release paper of the present invention coat an ultra-low surface tension coating before coating the electron beam curable release paper coating and cure it through the curing device 6, so as to reduce the surface tension of the concave embossing roller 1, and further reduce the surface tension of the produced leather release paper 200, increase the number of uses of the leather release paper 200 and reduce the cost.

[0078] The technical features of the above-mentioned embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0079] The above-mentioned embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A leather release paper production device for producing leather release paper, characterized in that: The leather release paper production device includes a concave embossing roller, a first coating roller that abuts against the concave embossing roller, a first material box for supplying the first coating roller to pick up an ultra-low surface tension coating, a second coating roller that abuts against the concave embossing roller, a second material box for supplying the second coating roller to pick up an electron beam curable release paper coating, and a curing device that faces the concave embossing roller to cure the coating on the concave embossing roller. The first coating roller and the second coating roller are arranged at a radial interval. The curing device is arranged radially between the first coating roller and the second coating roller. The ultra-low surface tension coating contains a silicone material and a diluent. The silicone material is one or more of a high molecular silicone resin, a low molecular silicone oil, a vinyl silicone oil, a hydrogen-containing silicone oil, and an acrylate-modified silicone oil. The diluent is one or more of isobornyl acrylate, lauryl acrylate, isooctyl acrylate, toluene, and xylene.

2. The leather release paper production device according to claim 1, characterized in that: In the vertical direction, the first coating roller and the second coating roller abut against the lower side of the concave embossing roller.

3. The leather release paper production device according to claim 1, characterized in that: The leather release paper production device further includes an electron beam dryer arranged on the upper side of the concave embossing roller.

4. The leather release paper production device according to claim 1, characterized in that: The curing device is one or more of a thermal curing device, a UV light curing device, and an electron beam curing device.

5. The leather release paper production device according to claim 1, characterized in that: The leather release paper production device further includes turning rollers arranged horizontally on both sides of the concave embossing roller.

6. The leather release paper production device according to claim 1, characterized in that: The components and mass percentages of the electron beam curable release paper coating are as follows: polyurethane acrylate resin 40 - 80%; high functionality acrylate monomer 10 - 50%; release agent 5 - 10%.

7. A production method of a leather release paper, characterized in that: The production method of leather release paper includes the following steps: S1: Provide the leather release paper production device according to any one of claims 1 - 6; S2: Prepare an ultra-low surface tension coating and place it in the first material box, prepare an electron beam curable release paper coating and place it in the second material box; S3: Rotate the concave embossing roller, and the first coating roller coats the ultra-low surface tension coating in the first material box on the concave embossing roller; S4: Start the curing device to cure the ultra-low surface tension coating coated on the concave embossing roller; S5: The concave embossing roller coated with the cured ultra-low surface tension coating abuts against the second coating roller, and the second coating roller coats the electron beam curable release paper coating on the concave embossing roller; S6: The concave embossing roller rotates further until it abuts against the leather release paper base paper, and directly copies the pattern on the concave embossing roller onto the leather release paper base paper.

8. The production method of the leather release paper according to claim 7, characterized in that: The leather release paper production device further includes an electron beam dryer arranged on the upper side of the concave embossing roller. After step S6 of the production method of leather release paper, it further includes: Before the leather release paper and the concave embossing roller are separated, use the electron beam dryer to cure the electron beam curable release paper coating on the concave embossing roller.

Images