Preparation method of low-residue water transfer printing paper

Abstract

The invention provides a preparation method of low-residue water transfer printing paper, the low-residue water transfer printing paper comprises a bottom paper, a bottom glue layer and a surface glue layer structure which are stacked, and the preparation method of the low-residue water transfer printing paper comprises the following steps: preparing water-absorbent resin bottom glue; coating the surface of bottom paper with the water-absorbent resin primer glue, and drying the bottom paper coated with the water-absorbent resin primer glue with hot air, so that the water-absorbent resin primer glue forms a primer layer to obtain primer transition paper; preparing surface glue; coating the primer transition paper with the surface glue, and drying the primer transition paper coated with the surface glue with hot air so as to enable the surface glue to form a surface glue layer, thereby obtaining the low-residue water transfer printing paper. The water-absorbent resin primer glue has good adhesiveness and is not easy to dissolve in water, the primer layer of the water transfer paper is formed after baking, the water-absorbent resin primer glue which is not easy to dissolve in water is formed again by the primer layer and water, the time for dissolving the water-absorbent resin primer glue in water is prolonged, and the residual glue on the printing layer is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of water transfer printing, and in particular to a method for preparing low-residue water transfer paper. Background Art

[0002] Transfer paper is a specific product for the purpose of transferring printed images. Water transfer paper uses special paper as the base material. Through three sizing processes on the surface of the paper, kaolin coating, base glue coating and surface glue coating are formed on the surface of the special paper base paper. The base glue coating and the surface glue coating are both water-soluble glue layers, and the surface glue layer needs to have good sliding properties. After three sizing on the front side, it is necessary to apply sizing again on the back side of the base paper to achieve the purpose of paper shaping and stable structure. Traditional water transfer paper consists of a five-layer structure. When using water transfer paper, the pigment is printed on the surface of the water transfer paper surface glue coating through the printing equipment to form a pattern and dry it. After printing, the back of the water transfer printing paper contacts water, and the water penetrates the paper page to dissolve the surface coating to obtain a complete pattern printing layer, and then the printing layer is transferred and pasted on the target object to form a complete and exquisite pattern.

[0003] The kaolin coating on the surface of water transfer paper is a water-insoluble coating, while the base coating and the top coating are both water-soluble coatings. The purpose of pattern peeling and transfer is achieved by dissolving the coating. Since the base coating and the top coating on the surface of water transfer paper are both water-soluble coatings, during the process of peeling and transferring the pattern of the printing layer, the pattern separated from the printing layer will carry the dissolved glue. When the pattern of the printing layer with residual glue is printed on the target object, the pattern of the printing layer may form a slight foggy residual mark on the surface of the object or produce a slight spotty color difference mark after baking.

[0004] For example, the comparative document CN202011626316.3 discloses a water transfer paper and its production process for improving the transfer efficiency of sandblasting flower paper, including a kaolin coating, a primer coating and a surface coating sequentially arranged on the water transfer base paper, wherein the primer coating is made of the following components in parts by weight: 100 parts of water, 38-43 parts of potato modified starch; the surface coating is made of the following components in parts by weight: 100 parts of water, 20-30 parts of corn maltodextrin, and 1-3 parts of polyvinyl alcohol. This scheme maximizes the strong adhesion and film-forming properties of the primer coating through the appropriate ratio of potato modified starch and water; the surface coating ensures that the surface coating film has strong film-forming properties and film strength through the appropriate ratio of corn maltodextrin, polyvinyl alcohol and water, avoiding the destructive effect of the printing process of the sandblasting printing process on the surface coating of the water transfer paper. However, the base glue coating and the surface glue coating of this solution are both easily soluble in water, and the dissolved glue is easily retained in the process of peeling and transferring the pattern of the printing layer, resulting in residual traces of the pattern of the printing layer after baking. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing low-residue water transfer paper that is not easily dissolved and reduces glue residue in the printing layer.

[0006] The purpose of this disclosure is achieved through the following technical solutions:

[0007] A method for preparing low-residue water transfer paper, the low-residue water transfer paper comprising a stacked base paper, a base glue layer and a surface glue layer structure, the low-residue water transfer paper adopts the following steps:

[0008] preparing water-absorbing resin primer glue;

[0009] The preparation of the water-absorbing resin base glue includes the following mass components:

[0010] 200-300 parts of potato starch;

[0011] Water 696-799 parts;

[0012] 1-4 parts of polymer water-absorbing resin powder;

[0013] The water-absorbing resin base glue is applied to the surface of the base paper, and the base paper coated with the water-absorbing resin base glue is dried with hot air so that the water-absorbing resin base glue forms a base glue layer to obtain a base glue transition paper;

[0014] Prepare the surface glue;

[0015] The surface glue is coated on the base glue transition paper, and the base glue transition paper coated with the surface glue is dried by hot air so that the surface glue forms a surface glue layer, so as to obtain a water transfer paper with low residue.

[0016] In one embodiment, the polymer water-absorbing resin powder is polyacrylamide powder.

[0017] In one embodiment, the preparation of the water-absorbing resin primer glue comprises the following steps:

[0018] The reactor is charged with materials, water is added into the reactor, and potato starch is added into the reactor and stirred to form a starch mixed slurry;

[0019] The starch mixed slurry is heated and heated, and the reaction kettle heats and stirs the starch mixed slurry to form a preheated starch slurry;

[0020] Evenly sprinkle polyacrylamide powder into the reaction kettle and stir evenly to form resin starch slurry;

[0021] The resin starch slurry is heated and gelatinized, and the reaction kettle heats and stirs the resin starch slurry so that the resin starch slurry is gelatinized to form the water-absorbing resin base glue.

[0022] In one embodiment, the heating temperature is 55°C-60°C, and the heating time is 28min-30min.

[0023] In one embodiment, the heating gelatinization temperature is 60°C-80°C, and the heating gelatinization time is 5min-10min.

[0024] In one of the embodiments, after the slurry is heated and gelatinized, the step further includes allowing the water-absorbing resin base glue to stand.

[0025] In one of the embodiments, after the water-absorbing resin primer glue is allowed to stand, the viscosity of the water-absorbing resin primer glue is tested.

[0026] In one of the embodiments, when the water-absorbent resin base glue is coated on the surface of the base paper, the coating amount of the water-absorbent resin base glue is 10g / m3-15g / m3.

[0027] In one embodiment, the surface glue comprises the following mass components:

[0028] 100-150 parts corn starch;

[0029] 850-900 parts of water.

[0030] In one of the embodiments, the coating amount of the surface glue is 1g / m3-2g / m3.

[0031] Compared with the prior art, the present invention has at least the following advantages:

[0032] The method for preparing low-residue water transfer paper comprises the following steps: adding polymer water-absorbing resin powder to water-absorbing resin base glue, so that the prepared water-absorbing resin base glue has good adhesion performance and is not easily soluble in water; the base glue layer formed after the water-absorbing resin base glue is baked contains polymer water-absorbing resin; when the low-residue water transfer paper printed with a printing layer is immersed in water, the base glue layer contacts water to re-form water-absorbing resin base glue with good adhesion performance and not easily soluble in water; the water-absorbing resin base glue has good water absorption performance, so that water quickly contacts the surface glue layer, so that the surface glue layer quickly dissolves, thereby accelerating the separation speed of the printing layer and the low-residue water transfer paper; the water-absorbing resin base glue adheres well to the base paper, the water-absorbing resin base glue is not easily soluble in water, and the time for the water-absorbing resin base glue to dissolve in water is extended, thereby preventing the water-absorbing resin base glue from remaining on the printing layer, greatly reducing the water-soluble glue, and thereby reducing the traces and spotted color difference traces of the printing layer after baking. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A flow chart of a method for preparing low-residue water transfer paper according to an embodiment;

[0035] Figure 2 The present invention is a flow chart for preparing water-absorbing resin primer glue. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0037] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0040] The present invention relates to a method for reducing the triethylenediamine content of a foamed part. In one embodiment, a method for preparing low-residue water transfer paper, the low-residue water transfer paper comprising a stacked base paper, a base glue layer and a top glue layer structure, the low-residue water transfer paper adopts the following steps:

[0041] preparing water-absorbing resin primer glue;

[0042] The preparation of the water-absorbing resin base glue includes the following mass components:

[0043] 200-300 parts of potato starch;

[0044] Water 696-799 parts;

[0045] 1-4 parts of polymer water-absorbing resin powder;

[0046] The water-absorbing resin base glue is applied to the surface of the base paper, and the base paper coated with the water-absorbing resin base glue is dried with hot air so that the water-absorbing resin base glue forms a base glue layer to obtain a base glue transition paper;

[0047] Prepare the surface glue;

[0048] The surface glue is coated on the base glue transition paper, and the base glue transition paper coated with the surface glue is dried by hot air so that the surface glue forms a surface glue layer, so as to obtain a water transfer paper with low residue.

[0049] See also Figure 1 , which is a method for preparing low-residue water transfer paper according to an embodiment of the present invention, the low-residue water transfer paper comprises a laminated base paper, a base glue layer and a surface glue layer structure, and the preparation method of the low-residue water transfer paper comprises the following steps:

[0050] S101 prepares water-absorbing resin primer glue;

[0051] The preparation of water-absorbing resin base glue includes the following mass components:

[0052] 200-300 parts of potato starch;

[0053] Water 696-799 parts;

[0054] 1-4 parts of polymer water-absorbent resin powder.

[0055] In this embodiment, potato starch has the characteristics of low gelatinization temperature compared with other cereal starches, and the gelatinization process is fast, so that the process of producing water-absorbing resin base glue from potato starch is simple, energy consumption is low, production speed is fast, potato starch has high viscosity after gelatinization, and transparency after gelatinization is good, so that the produced water-absorbing resin base glue has good viscosity and transparency;

[0056] Furthermore, the polymer water-absorbent resin powder includes at least one of polyacrylamide, sodium polyacrylate and sodium alginate, and the polymer water-absorbent resin powder is water-absorbent, and the polymer water-absorbent resin powder can increase the adhesion performance of the water-absorbent resin base glue. When the content of the polymer water-absorbent resin powder added to the water-absorbent resin base glue is greater than 4‰, the interaction between the polymer water-absorbent resin powder, starch and water molecules is relatively strong, and the water-absorbent resin base glue forms a gel-like water-absorbent resin base glue with good toughness. The water-absorbent resin base glue behaves as a viscoelastic solid, and the gel-like water-absorbent resin base glue cannot be coated. The proportion of the polymer water-absorbent resin powder in the total amount of the water-absorbent resin base glue needs to be reduced, so that the formed water-absorbent resin base glue has good fluidity, thereby facilitating the coating of the water-absorbent resin base glue on the surface of the base paper. When the content of the polymer water-absorbent resin powder added to the water-absorbent resin base glue is less than 4‰, the polymer water-absorbent resin powder is added to the starch slurry and mixed, so that the polymer water-absorbent resin powder, starch and water molecules are mixed, and the three-dimensional network structure of the water-absorbent resin and the hydrophilic groups, water and starch molecules interact with each other, so that the polymer water-absorbent resin powder, starch and water molecules are more tightly bound, and with the continuous infiltration of water molecules, the three-dimensional network structure of the water-absorbent resin begins to swell and bind water molecules to prevent water molecules from overflowing, and the water-absorbent resin increases the adhesion between gelatinized starch particles, thereby increasing the stability of gelatinized starch, making the water-absorbent resin base glue not easily soluble in water, forming a sol-like base glue with stronger adhesion, so that the water-absorbent resin base glue has fluidity and can be coated on the base paper. It is understandable that when the content of the polymer water-absorbing resin powder added to the water-absorbing resin base glue is less than 1‰, the interaction between the polymer water-absorbing resin powder, starch and water molecules is relatively low, the distance between the polymer water-absorbing resin powder and starch and water molecules is relatively far, and the adhesion of the formed glue is not strong enough, so that the water-absorbing resin base glue dissolves in water faster. Therefore, the content of the polymer water-absorbing resin powder added to the water-absorbing resin base glue is 1‰-4‰, so that the prepared water-absorbing resin base glue forms a sol with fluidity, and the water-absorbing resin base glue has strong adhesion and is not easy to dissolve in water.

[0057] S103: Apply the water-absorbent resin primer glue to the surface of the base paper, and perform hot air drying on the base glue transition paper coated with the water-absorbent resin primer glue, so that the water-absorbent resin primer glue forms a primer layer, so as to obtain the base glue transition paper. In this embodiment, the primer layer contains a polymer water-absorbent resin and gelatinized starch particles, so that the primer layer has good adhesion and water absorption. When the base glue transition paper is placed in water, after the water passes through the base paper, the polymer water-absorbent resin and the gelatinized starch particles can quickly absorb water and swell, thereby re-forming a water-absorbent resin primer glue with strong adhesion and difficulty in dissolving.

[0058] S105: preparing the surface glue. In this embodiment, the surface glue is produced by gelatinizing corn starch and water. After gelatinization, corn starch has good solubility, low viscosity and good transparency, so that the surface glue has good solubility and low viscosity, thereby accelerating the separation speed of the base glue layer and the printing layer.

[0059] S107: Apply the surface glue to the bottom glue transition paper, and perform hot air drying on the bottom glue transition paper coated with the surface glue, so that the surface glue forms a surface glue layer, so as to obtain the low-residue water transfer paper. In this embodiment, the surface glue has good solubility, so that when the low-residue water transfer paper is placed in water, the surface glue layer can be quickly dissolved; the surface glue has low viscosity, so that the amount of surface glue that can be applied to the bottom glue layer is small, and the surface glue layer formed by the surface glue is thin, which increases the dissolution rate of the surface glue layer, so that the separation speed of the printing layer and the bottom glue layer on the low-residue water transfer paper is faster, and the residual amount of the surface glue layer is less, so as to prevent the residual surface glue from being transferred to the ceramic surface by the printing layer.

[0060] In this embodiment, when the print layer on the low-residue water transfer paper is undergoing water transfer, when the low-residue water transfer paper is placed in water, water is absorbed through the bottom of the base paper and penetrates into the base glue layer. After the base glue layer absorbs water, a base glue transition layer that is not easily soluble in water is formed. After passing through the base glue transition layer, the water contacts the surface glue layer, causing the surface glue layer to dissolve quickly. The print layer on the surface glue layer is quickly separated from the surface glue layer, and then the print layer is transferred to the ceramic surface and baked at high temperature, so that a beautiful print layer is attached to the ceramic surface.

[0061] The method for preparing low-residue water transfer paper comprises the following steps: adding polymer water-absorbing resin powder to water-absorbing resin base glue, so that the prepared water-absorbing resin base glue has good adhesion performance and is not easily soluble in water; the base glue layer formed after the water-absorbing resin base glue is baked contains polymer water-absorbing resin; when the low-residue water transfer paper printed with a printing layer is immersed in water, the base glue layer contacts water to re-form water-absorbing resin base glue with good adhesion performance and not easily soluble in water; the water-absorbing resin base glue has good water absorption performance, so that water quickly contacts the surface glue layer, so that the surface glue layer quickly dissolves, thereby accelerating the separation speed of the printing layer and the low-residue water transfer paper; the water-absorbing resin base glue adheres well to the base paper, the water-absorbing resin base glue is not easily soluble in water, the time for the water-absorbing resin base glue to dissolve in water is extended, the glue soluble in water is greatly reduced, and the traces and spotted color difference traces of the printing layer after baking are reduced.

[0062] In one embodiment, the water-absorbent resin base glue is applied to the surface of the base paper, and the base paper coated with the water-absorbent resin base glue is hot-air dried, and the temperature of the hot-air drying is 120° C.-160° C. In this embodiment, the base paper has different specifications. When the water-absorbent resin base glue is applied to a base paper with a smaller area and the coating is thinner, the obtained base glue transition paper requires a relatively low hot-air drying temperature, so that the base glue transition paper is dried quickly; when the water-absorbent resin base glue is applied to a base paper with a larger area and the coating is thicker, the obtained base glue transition paper requires a higher hot-air drying temperature, so that the base glue transition paper dries faster.

[0063] In one embodiment, the polymer water-absorbing resin powder is polyacrylamide powder. Sodium polyacrylate powder is acidic, and the prepared water-absorbing resin base glue is acidic, which will cause irritation when the water transfer paper comes into contact with the human body. Therefore, when the water transfer paper has requirements for the pH value of the formed base glue layer, it is necessary to use a pH-neutral material for preparation; sodium alginate has a poor thickening effect on the base glue, and more polymer absorbent resin powder needs to be added. Therefore, polyacrylamide powder is used to prepare a water-absorbent resin base glue. The polyacrylamide powder has a fast dissolution rate. Polyacrylamide can form a stable blend with gelatinized starch in water, so that the starch particles can absorb water and gelatinize better. There are a large number of polar groups in the molecular chain of polyimide. The presence of these groups makes the molecules have a strong interaction force. The interaction force between the molecules is enhanced to improve the thickening effect and adhesion performance of the starch, so that the water-absorbent resin base glue that is not easily soluble in water formed by the blend of polyacrylamide and gelatinized starch has better adhesion performance. After the polyacrylamide and gelatinized starch blend is dried, a base glue layer is formed. The base glue layer absorbs water to re-form a water-absorbent resin base glue with good co-adhesion performance of polyacrylamide and gelatinized starch. The water-absorbent resin base glue has good water permeability and is not easily soluble in water.

[0064] See also Figure 2 In one embodiment, the preparation of the water-absorbing resin primer glue comprises the following steps:

[0065] S1011: Feed the reactor, add water into the reactor, and then add potato starch into the reactor for stirring to form a starch mixed slurry. In this embodiment, the potato starch is mixed with cold water, and the water mainly enters the starch granules through the pores of the starch granules. The water is simply adsorbed on the surface of the starch granules. The starch and water are mixed by stirring in the reactor to form a starch mixed slurry in a suspended state.

[0066] S1013 heats the starch mixed slurry, and the reactor heats and stirs the starch mixed slurry to form a preheated starch slurry. Heating increases the temperature of the water in the potato starch mixed slurry, making it easier for the potato starch particles to be more evenly dispersed in the water. The potato starch at this stage has not yet begun to gelatinize, and the starch mixed slurry is a suspension of potato starch particles and water, which is conducive to the dissolution of polyacrylamide powder.

[0067] S1015: evenly sprinkle the polyacrylamide powder into the reactor and stir evenly to form a resin starch slurry. In this embodiment, when the polyacrylamide powder is easily in contact with a small amount of cold water, the polyacrylamide powder concentration is too high and gel is easily generated, thereby causing the resin starch slurry to agglomerate. The polyacrylamide powder is slowly and evenly sprinkled into the preheated starch slurry. Since the preheated starch slurry is heated, the dissolution rate of polyacrylamide in water is faster, which reduces the agglomeration of the polyacrylamide powder, so that the polyacrylamide and the starch are evenly mixed to form a resin starch slurry.

[0068] S1017 heats and gelatinizes the resin starch slurry, and the reactor heats and stirs the resin starch slurry so that the resin starch slurry is gelatinized to form the water-absorbing resin base glue. In this embodiment, potato starch is gelatinized, and a large amount of water molecules penetrate into the starch granules, destroying the original arrangement of the starch, breaking the hydrogen bonds between the starch molecules, and the starch molecules are dispersed in the water to form a colloidal solution, and the starch molecules swell. As the gelatinization time increases, the viscosity of the water-absorbing resin base glue increases continuously to form a sol, and the three-dimensional mesh structure of polyacrylamide interacts with the hydrophilic group, water and starch molecules, so that the adhesion of the base glue forming the sol is enhanced, thereby making the base glue not easily soluble in water.

[0069] In one embodiment, the temperature of the heating is 55°C-60°C, and the time of the heating is 28min-30min. In this embodiment, the viscosity of the resin starch slurry formed by mixing potato starch, water and polyacrylamide powder is relatively low, so low-speed stirring is adopted so that the stirring speed of the reactor is 20r / min-30r / min to prevent the resin starch slurry in the reactor from splashing. The solubility of polyacrylamide powder in water increases with the increase of temperature. By heating the starch mixed slurry, it is beneficial for the polyacrylamide powder to dissolve in the starch mixed slurry, so that the polyacrylamide powder and the starch slurry are mixed evenly; the gelatinization temperature of potato starch is 60°C-80°C, and the heating temperature is 55°C-60°C, so that the properties of the potato starch in the starch mixed slurry are not changed, so that the viscosity of the starch mixed slurry is low, which is conducive to dissolving the polyacrylamide powder.

[0070] Furthermore, after the resin starch slurry is heated and gelatinized, the resin starch slurry forms the water-absorbent resin primer glue, and the water-absorbent resin primer glue is relatively insoluble in water. When the water-absorbent resin primer glue is too thick or too thin, when water is added to adjust the viscosity of the water-absorbent resin primer glue, it is easy to cause uneven mixing of the water-absorbent resin primer glue in the reactor, resulting in defective primer glue. Therefore, it is necessary to strictly control the water-absorbent resin primer glue and control the viscosity of the starch mixed slurry so that the viscosity of the primer glue formed by the starch mixed slurry remains stable.

[0071] When the polyacrylamide powder accounts for less than 4‰ of the total amount of the primer glue, before adding the polyacrylamide powder into the reactor to heat and gelatinize the resin starch slurry, the viscosity of the resin starch slurry is controlled, and the viscosity control of the resin starch slurry includes the following steps:

[0072] The resin starch slurry was stirred for 5 min and a sample was taken from the reactor;

[0073] For sampling and testing of resin starch slurry, the viscometer uses 1# rotor at 60r / min to test the samples;

[0074] When the viscosity value of the sample is lower than 10 mPa·s, 0.1‰ of polyacrylamide powder and 0.9‰ of water are added, the resin starch slurry is stirred for 5 minutes, and the resin starch slurry is repeatedly sampled for viscosity testing. When the total amount of the added polyacrylamide powder is equal to 4‰, the addition of polyacrylamide powder is stopped;

[0075] When the sampled viscosity value is higher than 15 mPa·s, 1% of water is added, the resin starch slurry is stirred for 5 minutes, and the sampled resin starch slurry is repeatedly sampled to perform viscosity testing.

[0076] In the present embodiment, the resin starch slurry is composed of unmodified starch, polyacrylamide and water. The viscosity of the resin starch slurry is mainly affected by the viscosity of the glue formed by polyacrylamide dissolved in water. The change in the viscosity of the resin starch slurry can reflect the change in the viscosity of polyacrylamide in water. By controlling the polyacrylamide content before the gelatinization of potato starch, the problem of too little polyacrylamide content resulting in too low viscosity of the prepared water-absorbent resin base glue is reduced, and the problem of too high polyacrylamide content resulting in too high viscosity of the prepared water-absorbent resin base glue resulting in a gel state and resulting in scrap is reduced.

[0077] In one embodiment, the heating gelatinization temperature is 60°C-80°C, and the heating temperature rise time is 5min-10min. In this embodiment, potato starch is gelatinized at a temperature of 60°C-80°C, so that the resin starch slurry forms a viscous base glue. When the heating temperature is lower than 60°C, the gelatinization temperature of potato starch is not reached, so that the potato starch is not gelatinized. When the heating temperature exceeds 80°C, the structure of the gelatinized potato starch is easily destroyed, so the gelatinization temperature needs to be controlled below 80°C. Further, the stirring speed is 20r / min-40r / min. After the potato starch is gelatinized, a viscous base glue is formed. When the reactor stirs the water-absorbent resin base glue, when the stirring speed of the reactor is greater than 40r / min, the stirring paddle of the reactor continuously shears the water-absorbent resin base glue. When the water-absorbent resin base glue is subjected to a shearing speed that is too fast, the gelatinized potato starch molecules are shredded, resulting in a decrease in the viscosity and adhesion of the base glue. When the stirring speed of the reactor is less than 20r / min, the reactor is locally heated through the middle, and the mixing speed of the potato starch is too slow. A portion of the potato starch near the middle of the reactor has completed gelatinization, while another portion of the potato starch far from the middle of the reactor has not yet completed gelatinization, resulting in different viscosities of the potato starch in different parts of the formed water-absorbent resin base glue, making the base glue uneven.

[0078] In one embodiment, after the slurry is heated and gelatinized, the water-absorbing resin base glue is allowed to stand, the heating device is turned off, and the water-absorbing resin base glue is allowed to stand. In this embodiment, the standing time is 10-15 minutes, the water-absorbing resin base glue is heated in the reactor, and when the reactor stops heating, the residual heat of the reactor allows the starch particles in the base glue to react completely, and the water-absorbing resin base glue has a certain thixotropy. By stopping stirring and cooling naturally, the state of the water-absorbing resin base glue is more stable.

[0079] In one embodiment, after the base glue is allowed to stand, the viscosity of the water-absorbing resin base glue is also tested. In this embodiment, the viscosity of the water-absorbing resin base glue is 98mPa·s-398mPa·s, and the water-absorbing resin base glue is tested at 25°C using a viscometer 1# rotor at 60r / min. When the viscosity of the water-absorbing resin base glue is too high, the water-absorbing resin base glue is easily excessively adhered to the coating equipment during coating, and the surface of the coated base paper is prone to unevenness; when the viscosity of the water-absorbing resin base glue is too low, the interaction between polyacrylamide, starch and water molecules is insufficient, so that the water-absorbing resin base glue formed by polyacrylamide, starch and water dissolves in water too quickly, resulting in the water-absorbing resin base glue remaining in the printing layer, which in turn leads to the problem of residual traces in the printing layer after baking.

[0080] Further, when the viscosity of the primer glue is lower than 98 mPa·s, a water-absorbing resin primer glue with a higher viscosity is mixed into the water-absorbing resin primer glue with a low viscosity to increase the viscosity of the water-absorbing resin primer glue. Mixing the water-absorbing resin primer glue with a low viscosity includes the following steps:

[0081] First, mix the water-absorbing resin base glue into the thick water-absorbing resin base glue of 150mPa·s-200mPa·s, and stir to mix;

[0082] Testing the mixed water-absorbing resin primer glue;

[0083] If the viscosity of the mixed water-absorbent resin base glue is lower than 98mPa·s after mixing, repeat the mixing of the water-absorbent resin base glue with lower viscosity; if the viscosity of the mixed base glue is higher than 98mPa·s, use the water-absorbent resin base glue for coating base paper with a thinner coating layer and a smaller coating amount.

[0084] When the viscosity of the water-absorbent resin primer glue is greater than 398 mPa·s, if the water-absorbent resin primer glue is in a viscous melt state or a semi-gel state, and the water-absorbent resin primer glue can still be coated, the water-absorbent resin primer glue is coated on the base paper with a thicker coating layer and a larger coating amount through a coating machine. If the water-absorbent resin primer glue is in a gel state and cannot be coated, the water-absorbent resin primer glue is dried and the solid waste is recycled.

[0085] Further, if the viscosity of the glue is between 98mPa·s-398mPa·s, after testing the viscosity of the water-absorbing resin primer glue, the water solubility test of the water-absorbing resin primer glue is also included. The water solubility test of the water-absorbing resin primer glue includes the following steps:

[0086] Applying the water-absorbing resin primer glue on the surface of the test paper;

[0087] Drying the test paper to form a primer layer on the surface of the test paper;

[0088] Soaking the test paper, and observing the time it takes for the base glue layer of the test paper to dissolve in water;

[0089] If the time it takes for the base glue layer of the test paper to dissolve in water is greater than 1 minute, the water-absorbing resin base glue is qualified;

[0090] If the time it takes for the base glue layer of the test paper to dissolve in water is less than 1 minute, the water-absorbent resin base glue is the water-absorbent resin base glue to be treated. After mixing the water-absorbent resin base glue with a higher polyacrylamide content into the water-absorbent resin base glue to be treated, the water solubility of the mixed water-absorbent resin base glue is tested.

[0091] It is understandable that there are differences in the batch performance of raw materials. During storage, polyacrylamide or potato starch may be affected by moisture and other factors, which leads to differences in the quality components of the water-absorbing resin primer glue. The water solubility of the produced water-absorbing resin primer glue must be verified to ensure the quality of the water-absorbing resin primer glue. By testing the water solubility of the water-absorbing resin primer glue, the output of defective water-absorbing resin primer glue is reduced, and the production process of the water-absorbing resin primer glue can be further adjusted according to the test results, thereby optimizing the performance of the water-absorbing resin primer glue.

[0092] In one embodiment, when the water-absorbent resin base glue is coated on the surface of the base paper, the coating amount of the water-absorbent resin base glue is 10g / m 3 -15g / m 3 In this embodiment, the water-absorbent resin base glue is first poured into the glue tank of the coating device, and then the base paper is coated by the coating device. Compared with the formula of the traditional glue containing potato starch and water, the water-absorbent resin base glue is added with polyacrylamide, and the adhesion between the potato starch particles and the polyacrylamide is increased, so that the viscosity of the water-absorbent resin base glue is increased, thereby increasing the connection strength between the water-absorbent resin base glue and the base paper, avoiding the water-absorbent resin base glue from remaining on the printing layer after dissolution, thereby reducing the residual traces of the printing layer.

[0093] Furthermore, when the content of potato starch accounts for more than 20% of the content of the water-absorbing resin base glue, the adhesion between the potato starch particles and the polyacrylamide increases, so that the viscosity of the water-absorbing resin base glue increases. When preparing a water-absorbing resin base glue with a viscosity similar to that of the original production process, the content of potato starch can be reduced, thereby reducing production costs. Therefore, before preparing the water-absorbing resin base glue, the preparation process also includes adjusting the mass components of the water-absorbing resin base glue:

[0094] Mix potato starch with water to prepare a standard solution of primer glue;

[0095] The test of reducing the content of potato starch in the water-absorbing resin base glue is to reduce the potato starch content of the water-absorbing resin base glue by 1%, increase the water content of the water-absorbing resin base glue by 1%, and add 1‰-4‰ polyacrylamide to prepare the water-absorbing resin base glue test solution.

[0096] The viscosity of the base glue standard solution is tested, and the viscosity of the water-absorbing resin base glue test solution is tested.

[0097] If the difference between the viscosity value of the primer marking liquid and the viscosity value of the water-absorbing resin primer glue test liquid is less than 50 mPa·s, stop adjusting the proportion of potato starch in the water-absorbing resin primer glue content.

[0098] If the difference between the viscosity values ​​of the primer standard solution and the water-absorbent resin primer test solution is greater than 50 mPa·s, repeat the test of reducing the potato starch content of the water-absorbent resin primer; when the potato starch content is equal to 20%, stop adjusting the proportion of potato starch in the water-absorbent resin primer.

[0099] In this embodiment, by adjusting the mass components of the water-absorbent resin base glue, the viscosity of the base glue with polyacrylamide added to potato starch is adjusted to be similar to that of the base glue without polyacrylamide added, so that the coating effect of the water-absorbent resin base glue is maintained on the base paper, and the content of potato starch is reduced. Polyacrylamide can also increase the insolubility of the base glue, avoid the dissolution of the water-absorbent resin base glue, and reduce the amount of water-absorbent resin base glue remaining on the printing layer. The water-absorbent resin base glue can reduce the original content of potato starch by 15%-20%, thereby reducing production costs.

[0100] In one embodiment, the surface glue comprises the following mass components:

[0101] 100-150 parts corn starch;

[0102] 850-900 parts of water.

[0103] In this embodiment, the water content of the surface glue is high, and the viscosity of the corn starch after gelatinization is low, so that the viscosity of the surface glue prepared by gelatinization of corn starch is low, and the viscosity of the surface glue is 10mPa·s-15mPa·s. The low viscosity of the surface glue makes the surface glue coating simple and the surface glue layer formed by coating is thinner.

[0104] In one embodiment, the coating amount of the water-soluble surface glue is 1g / m 3 -2g / m 3 In this embodiment, the ratio of the coating amount of the water-soluble surface glue to the coating amount of the water-absorbing resin base glue is 1:5, and the coating amount of the surface glue is small, so that the thickness of the surface glue layer formed by the surface glue is thinner; when the low-residue water transfer paper with a printing layer is placed in water, water enters the base glue layer through the base paper, and the base glue layer absorbs water to form an insoluble layer that is difficult to dissolve, and the thin surface glue layer in contact with the base glue layer quickly dissolves, so that the printing layer and the insoluble layer are quickly separated, thereby reducing the residual glue in the printing layer and avoiding traces of residual glue in the printing layer.

[0105] Compared with the prior art, the present invention has at least the following advantages:

[0106] The method for preparing low-residue water transfer paper comprises the following steps: adding polymer water-absorbing resin powder to water-absorbing resin base glue, so that the prepared water-absorbing resin base glue has good adhesion performance and is not easily soluble in water; the base glue layer formed after the water-absorbing resin base glue is baked contains polymer water-absorbing resin; when the low-residue water transfer paper printed with a printing layer is immersed in water, the base glue layer contacts water to re-form water-absorbing resin base glue with good adhesion performance and not easily soluble in water; the water-absorbing resin base glue has good water absorption performance, so that water quickly contacts the surface glue layer, so that the surface glue layer quickly dissolves, thereby accelerating the separation speed of the printing layer and the low-residue water transfer paper; the water-absorbing resin base glue adheres well to the base paper, the water-absorbing resin base glue is not easily soluble in water, the time for the water-absorbing resin base glue to dissolve in water is extended, the glue soluble in water is greatly reduced, and the traces and spotted color difference traces of the printing layer after baking are reduced.

[0107] Some specific examples are given below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0108] Comparative Example 1

[0109] The base glue of comparative example 1 is prepared from 800 kg of water and 200 kg of potato starch. The base glue of comparative example 1 is coated on the surface of the base paper and dried with hot air to form the base glue transition paper of comparative example 1. The top glue is prepared from 850 kg of water and 150 kg of corn starch. The top glue is coated on the base glue transition paper, and the base glue transition paper is dried with hot air to form the water transfer paper of comparative example 1. The printing layer is printed on the water transfer paper of comparative example 1.

[0110] Example 1

[0111] The water-absorbing resin base glue of Example 1 is prepared from 798 kg of water, 200 kg of potato starch, and 2 kg of sodium polyacrylate. The water-absorbing resin base glue of Example 1 is applied to the surface of the base paper and dried with hot air to form the base glue transition paper of Example 1. The top glue is prepared from 850 kg of water and 150 kg of corn starch. The top glue is applied to the base glue transition paper, and the base glue transition paper is dried with hot air to form the water transfer paper of Example 1, and the print layer is printed on the water transfer paper of Example 1.

[0112] Example 2

[0113] The water-absorbing resin base glue of Example 2 is prepared from 799.5 kg of water, 200 kg of potato starch, and 0.5 kg of polyacrylamide. The water-absorbing resin base glue of Example 2 is applied to the surface of the base paper and hot-air dried to form the base glue transition paper of Example 2. The top glue is prepared from 850 kg of water and 150 kg of corn starch. The top glue is applied to the base glue transition paper, and the base glue transition paper is hot-air dried to form the low-residue water transfer paper of Example 2, and the print layer is printed on the low-residue water transfer paper of Example 2.

[0114] Example 3

[0115] The water-absorbing resin base glue of Example 3 is prepared from 799 kg of water, 200 kg of potato starch, and 1 kg of polyacrylamide. The water-absorbing resin base glue of Example 3 is applied to the surface of the base paper and hot-air dried to form the base glue transition paper of Example 3. The top glue is prepared from 850 kg of water and 150 kg of corn starch. The top glue is applied to the base glue transition paper, and the print layer is printed on the base glue transition paper. The base glue transition paper is hot-air dried to form the low-residue water transfer paper of Example 3, and the print layer is printed on the low-residue water transfer paper of Example 3.

[0116] Example 4

[0117] The water-absorbing resin base glue of Example 4 is prepared from 798 kg of water, 200 kg of potato starch, and 2 kg of polyacrylamide. The water-absorbing resin base glue of Example 4 is applied to the surface of the base paper and hot-air dried to form the base glue transition paper of Example 4. The top glue is prepared from 850 kg of water and 150 kg of corn starch. The top glue is applied to the base glue transition paper, and the base glue transition paper is hot-air dried to form the low-residue water transfer paper of Example 4, and the print layer is printed on the low-residue water transfer paper of Example 4.

[0118] Example 5

[0119] The water-absorbing resin base glue of Example 5 is prepared from 797 kg of water, 200 kg of potato starch, and 3 kg of polyacrylamide. The water-absorbing resin base glue of Example 5 is coated on the surface of the base paper and dried with hot air to form the base glue transition paper of Example 5. The top glue is prepared from 850 kg of water and 150 kg of corn starch. The top glue is coated on the base glue transition paper, and the base glue transition paper is dried with hot air to form the low-residue water transfer paper of Example 5, and the print layer is printed on the low-residue water transfer paper of Example 5.

[0120] Example 6

[0121] The water-absorbing resin base glue of Example 6 is prepared from 796 kg of water, 200 kg of potato starch, and 4 kg of polyacrylamide. The water-absorbing resin base glue of Example 6 is applied to the surface of the base paper and dried with hot air to form the base glue transition paper of Example 6. The top glue is prepared from 850 kg of water and 150 kg of corn starch. The top glue is applied to the base glue transition paper, and the base glue transition paper is dried with hot air to form the low-residue water transfer paper of Example 6, and the print layer is printed on the low-residue water transfer paper of Example 6.

[0122] Example 7

[0123] The water-absorbing resin base glue of Example 7 is prepared from 795.9 kg of water, 200 kg of potato starch and 4.1 kg of polyacrylamide. The water-absorbing resin base glue of Example 7 is coated on the surface of the base paper.

[0124] Table 1: Components of the primer glue of Comparative Example 1 and Examples 1-7

[0125]

[0126] Table 2: Test results of primer glue and water transfer paper of Comparative Example 1 and Examples 1-7

[0127]

[0128] The difference between Example 1 and Example 2-7 is that the water-absorbent resin powder of the water-absorbent resin base glue of Example 1 is sodium polyacrylate, and the water-absorbent resin powder of the water-absorbent resin base glue of Example 2-7 is polyacrylamide; the separation time is the separation time of the printing layer and the water transfer paper, and the difference between Example 2-7 is that the content of polyacrylamide in the water-absorbent resin base glue is different.

[0129] Compare the test results in Table 1 and Table 2:

[0130] It can be seen from the test results of Comparative Example 1 and Examples 1-7 that the viscosity of the base glue without adding water-absorbing resin is low, and the base glue layer and the surface glue layer of the water transfer paper made by the base glue without adding water-absorbing resin will dissolve quickly, and the dissolved sol is likely to remain in the printing layer;

[0131] From the test results of Example 2 and Example 4, it can be seen that the water-absorbing resin base glue with sodium polyacrylate added and the water-absorbing resin base glue with polyacrylamide added are not easily soluble in water, and they do not dissolve quickly after the printing layer is separated from the base paper, and the printing layer on the low-residue water transfer paper is not easy to have residual glue. However, the pH of the base glue with sodium polyacrylate added is relatively low, and the low-residue water transfer paper is not suitable for direct contact with the human body.

[0132] It can be seen from the test results of Example 2 to Example 7 that when the content of sodium polyacrylate in the water-absorbing resin base glue is 0.5‰, the base glue layer of the water transfer paper is hydrolyzed in water within 1 min, and the prepared water-absorbing resin base glue is more easily dissolved in water. When the content of the water-absorbing resin base glue of polyacrylamide is greater than 4‰, the water-absorbing resin base glue easily forms a colloid in a gel state and cannot be coated. When the content of sodium polyacrylate in the water-absorbing resin base glue is 1‰-4‰, the water-absorbing resin base glue can be coated on the surface of the base paper, and no dissolution occurs after the printing layer is separated from the base paper. The residual glue in the printing layer on the low-residue water transfer paper obtained is less or even no residue.

[0133] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the disclosed patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent shall be subject to the attached claims.

Claims

1. A method for preparing low-residue water transfer paper, the low-residue water transfer paper comprising a laminated base paper, a base glue layer and a top glue layer structure, characterized in that: The low-residue water transfer paper adopts a preparation method comprising the following steps: preparing water-absorbing resin primer glue; The preparation of the water-absorbing resin base glue includes the following mass components: 200-300 parts of potato starch; Water 696-799 parts; 1-4 parts of polymer water-absorbing resin powder; The water-absorbing resin base glue is applied to the surface of the base paper, and the base paper coated with the water-absorbing resin base glue is dried with hot air so that the water-absorbing resin base glue forms a base glue layer to obtain a base glue transition paper; Prepare the surface glue; The surface glue is coated on the base glue transition paper, and the base glue transition paper coated with the surface glue is dried by hot air so that the surface glue forms a surface glue layer, so as to obtain a water transfer paper with low residue.

2. The method for preparing low-residue water transfer paper according to claim 1, characterized in that: The polymer water-absorbing resin powder is polyacrylamide powder.

3. The method for preparing low-residue water transfer paper according to claim 2, characterized in that: The preparation of the water-absorbing resin primer glue comprises the following steps: Feeding the reactor, adding water into the reactor, and then adding potato starch into the reactor and stirring to form a starch mixed slurry; The starch mixed slurry is heated and heated, and the reaction kettle heats and stirs the starch mixed slurry to form a preheated starch slurry; Evenly sprinkle polyacrylamide powder into the reaction kettle and stir evenly to form resin starch slurry; The resin starch slurry is heated and gelatinized, and the reaction kettle heats and stirs the resin starch slurry so that the resin starch slurry is gelatinized to form the water-absorbing resin base glue.

4. The method for preparing low-residue water transfer paper according to claim 3, characterized in that: The heating temperature is 55°C-60°C, and the heating time is 28min-30min.

5. The method for preparing low-residue water transfer paper according to claim 3, characterized in that: The heating gelatinization temperature is 60° C.-80° C., and the heating gelatinization time is 5 min-10 min.

6. The method for preparing low-residue water transfer paper according to claim 3, characterized in that: After the slurry is heated and gelatinized, the method further includes allowing the water-absorbing resin primer glue to stand.

7. The method for preparing low-residue water transfer paper according to claim 6, characterized in that: After the water-absorbing resin base glue is allowed to stand, the viscosity of the water-absorbing resin base glue is tested.

8. The method for preparing low-residue water transfer paper according to claim 1, characterized in that: When the water-absorbent resin base glue is coated on the surface of the base paper, the coating amount of the water-absorbent resin base glue is 10g / m 3 -15g / m 3 .

9. The method for preparing low-residue water transfer paper according to claim 1, characterized in that: The surface glue comprises the following mass components: 100-150 parts corn starch; 850-900 parts of water.

10. The method for preparing low-residue water transfer paper according to claim 9, characterized in that: The coating amount of the surface glue is 1g / m 3 -2g / m 3 .

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