High-solid-content water-soluble starch glue suitable for printing or packaging industry and preparation method of high-solid-content water-soluble starch glue

Abstract

The invention discloses high-solid-content water-soluble starch glue suitable for printing or packaging industry and a preparation method thereof, and belongs to the field of glue, the high-solid-content water-soluble starch glue is mainly prepared from the following components: 100 parts by weight of modified starch, 50-450 parts by weight of functional filler, 0.01-10 parts by weight of surfactant and 3-20 parts by weight of fiber, 10-30 parts by weight of a drying agent and 120-200 parts by weight of water, and the solid content of the high-solid-content water-soluble starch glue is greater than or equal to 70 wt%. No caustic soda or borax participates in the gelatinization link, the solid content is high and is not smaller than 70 wt%, the total thickness and the compressive strength can be increased after the adhesive is used for adhering an adhered object, and moisture absorption and deformation are avoided.

Description

Technical Field

[0001] This invention relates to the field of adhesives, and in particular to a high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry and its preparation method. Background Technology

[0002] In the printing and packaging industry, adhesives are a crucial medium for transforming flat surfaces into three-dimensional forms, and components into finished products. They are not only the "invisible skeleton" of bookbinding, ensuring books are sturdy and providing a smooth reading experience, but also a "highly efficient adhesive" for the automatic forming and sealing of various cardboard boxes and cartons, directly determining the speed of the packaging production line and the structural integrity of the final product. The strength, environmental friendliness, and stability of their bonding effect profoundly impact the product's appearance, consumer safety, and the brand's premium image. Therefore, though hidden behind the scenes, adhesives are an indispensable foundation and core material in the entire industry.

[0003] Water-soluble starch adhesives have become an ideal choice for industries that consume large amounts of adhesives, such as corrugated cardboard and grey board, due to their excellent environmental friendliness, low cost, and good adhesion to porous materials.

[0004] Traditional water-soluble starch gums have the following drawbacks: (1) The solid content is low and the water content is high. The solid content is less than 50 wt%, and the solid content is usually between 10 wt% and 30 wt%, which leads to slow drying and requires a longer drying time or more powerful drying equipment.

[0005] (2) When using water-soluble starch adhesive for bonding, the water in the adhesive penetrates into the paper fibers, altering their physical properties, such as causing them to absorb water, become loose and deformed, and reducing their strength.

[0006] (3) In the starch gelatinization stage of adhesive preparation, caustic soda (NaOH) destroys the starch granule structure at high temperature, promotes complete gelatinization of starch granules and lowers the gelatinization temperature, while providing an alkaline environment to stabilize the colloid; borax, as a crosslinking agent, forms a complex structure with the borate ions generated by borax hydrolysis and the hydroxyl groups on the starch molecular chain, thereby greatly improving the initial tack and cohesive strength of the adhesive. Therefore, in the preparation of traditional water-soluble starch adhesive, caustic soda (NaOH) and borax are usually involved in the gelatinization stage. Although the amount added is small, caustic soda is an alkali and will affect the properties of the bonded material (paper and other paper products), while borax increases the brittleness of the bonded area after bonding and makes it easy to absorb moisture.

[0007] The above background information is provided to facilitate understanding of the present invention and is not intended to be publicly known technology disclosed to the general public prior to the application of this invention. Summary of the Invention

[0008] In view of the above-mentioned defects, the present invention provides a solution that aims to improve at least one of the problems mentioned in the background art.

[0009] The technical solution is: a high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry, mainly composed of the following components: 100 parts by weight of modified starch Functional fillers 50 parts by weight to 450 parts by weight Surfactant 0.01 parts by weight to 10 parts by weight 3 to 20 parts by weight of fiber 10 to 30 parts by weight of desiccant and 120 to 200 parts by weight of water The weight is expressed in one of the following quantities: gram, kilogram, thousand kilogram, or ten thousand kilogram; The solid content of the high-solids-content water-soluble starch adhesive is ≥70wt%.

[0010] Furthermore, the raw materials for making the high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry also include: Additives: 1 to 10 parts by weight.

[0011] Further, the additives are Fe2(SO4)3 and MgSO4, wherein MgSO4... 4 0.5 weight ~5 Parts by weight, MgSO 4 0.5 weight ~5 Parts by weight.

[0012] Furthermore, the surfactant is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant.

[0013] Furthermore, the surfactant is sodium dodecylbenzenesulfonate or dioctadecyldimethylammonium chloride.

[0014] Furthermore, the desiccant is an alcohol.

[0015] Furthermore, the functional filler is one or more of calcium carbonate, bentonite, and kaolin.

[0016] Furthermore, the fiber is one or more of wood fiber, paper fiber, or chemically synthesized fiber.

[0017] Furthermore, in the preparation process of the high solids content water-soluble starch adhesive suitable for the printing or packaging industry, after the modified starch is added, the ammeter reading of the stirring motor is observed. In the initial stage of adding the modified starch, the current of the stirring motor rises, then falls, until the current stabilizes and no longer falls, at which point subsequent materials are added.

[0018] The present invention also provides a method for preparing a high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry.

[0019] The technical solution is: a method for preparing the above-mentioned high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry, comprising the following steps: S1, add water and additives to the mixing reactor and stir until homogeneous; S2, add the modified starch to the mixing reactor, stir, and observe the ammeter reading of the stirring motor. In the initial stage of adding the modified starch, the current of the stirring motor rises, then falls, until the current stabilizes and no longer decreases. S3. Add the remaining materials to the mixing reactor and stir until homogeneous.

[0020] In this invention, solid content refers to the weight percentage of solid substances that actually play a bonding role in the adhesive after removing water and volatile substances from the adhesive.

[0021] Principle of this invention: In this invention, by observing the ammeter reading of the stirring motor after the modified starch is added, the ammeter reading shows that the current rises in the initial stage after the modified starch is added, and then the current decreases until it stabilizes and no longer decreases. Even without adding caustic soda (NaOH) and borax to participate in gelatinization, the modified starch of this invention can be well gelatinized.

[0022] In this invention, the addition of appropriate amounts of fiber and calcium carbonate allows the fibers in the bonding area to form a skeleton during bonding. Calcium carbonate and modified starch fill this skeleton and solidify, reducing shrinkage during drying and increasing bonding strength and paper thickness (while reducing production costs). Calcium carbonate increases the solids content in the adhesive, accelerates curing during bonding, and increases thickness and strength after bonding. The fibers increase the thickness of the bonding area and reduce the brittleness of the adhesive in the bonding area.

[0023] In this invention, the repulsive effect of electric charge is utilized to make the glue easily adhere to the paper.

[0024] In this invention, the addition of alcohols plays a role in drying and accelerating curing during the bonding and curing process.

[0025] In this invention, Fe2(SO4)3 is added during the preparation of the adhesive. Fe2(SO4)3 is an additive that makes the adhesive easier to penetrate into corrugated paper and other types of paper. On the one hand, it makes the high-solids content adhesive easier to bond, and on the other hand, it enhances the bonding strength, thus playing a penetrating bonding role.

[0026] In this invention, MgSO4 is used as an additive in the preparation of the adhesive, which improves the solubility of the modified starch in water, fully dissolves the modified starch in water, and increases its fluidity.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: The water-soluble starch adhesive of the present invention does not involve caustic soda and borax in the gelatinization process, has a high solid content, which can be no less than 70 wt%, and can increase the total thickness after being used to bond the adhered objects. Detailed Implementation

[0028] As used in this article: "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0029] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0030] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0033] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0034] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (K is any number representing a multiplier). It is important to understand that, unlike the number of parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0035] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0036] A high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry, mainly composed of the following components: 100 parts by weight of modified starch Functional fillers 50 parts by weight to 450 parts by weight Surfactant 0.01 parts by weight to 10 parts by weight 3 to 20 parts by weight of fiber 10 to 30 parts by weight of desiccant and 120 to 200 parts by weight of water The weight is expressed in one of the following quantities: gram, kilogram, thousand kilogram, or ten thousand kilogram; The solid content of the high-solids-content water-soluble starch adhesive is ≥70wt%.

[0037] In a specific embodiment of the present invention, preferably, the raw materials for making the high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry further include: Additives: 1 to 10 parts by weight.

[0038] In a specific embodiment of the present invention, preferably, the auxiliary agent is Fe2(SO4)3 and MgSO4, wherein MgSO4 4 0.5 weight ~5 Parts by weight, MgSO 4 0.5 weight ~5 Parts by weight.

[0039] In a specific embodiment of the present invention, preferably, the surfactant is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant.

[0040] In a specific embodiment of the present invention, preferably, the surfactant is sodium dodecylbenzenesulfonate or dioctadecyldimethylammonium chloride.

[0041] In a specific embodiment of the present invention, preferably, the desiccant is an alcohol.

[0042] In a specific embodiment of the present invention, preferably, the functional filler is one or more of calcium carbonate, bentonite, and kaolin.

[0043] In a specific embodiment of the present invention, preferably, the fiber is one or more of wood fiber, paper fiber or chemically synthesized fiber.

[0044] A method for preparing a high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry includes the following steps: S1, add water and additives to the mixing reactor and stir until homogeneous; S2, add the modified starch to the mixing reactor, stir, and observe the ammeter reading of the stirring motor. In the initial stage of adding the modified starch, the current of the stirring motor rises, then falls, until the current stabilizes and no longer decreases. S3. Add the remaining materials to the mixing reactor and stir until homogeneous.

[0045] In the following embodiments and comparative examples of the present invention, all materials were purchased from the market.

[0046] Example 1 A high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry, mainly composed of the following components: 100 kg of modified starch 200 kg of calcium carbonate Sodium dodecylbenzenesulfonate (LAS) 0.05 kg 3 kg of wood fiber Fe2(SO4)3 1.5 kg MgSO4 1.5 kg and 10 kg of methanol 120 kg of water Example 2 A high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry, mainly composed of the following components: 100 kg of modified starch 250 kg of calcium carbonate Sodium dodecylbenzenesulfonate (LAS) 0.1 kg 10 kg of wood fiber Fe2(SO4)3 3 kg MgSO4 3 kg and 20 kg of methanol 120 kg of water Example 3 A high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry, mainly composed of the following components: 100 kg of modified starch Calcium carbonate 420 kg Sodium dodecylbenzenesulfonate (LAS) 0.1 kg 20kg of wood fiber Fe2(SO4)3 1.5 kg MgSO4 1.5 kg and 10 kg of methanol 150 kg of water Comparative Example 1 The water-soluble starch adhesive used in this comparative example is a commercially available water-soluble starch adhesive (WG03) specifically designed for the printing or packaging industry.

[0047] The present invention also provides a method for preparing the high solids content water-soluble starch adhesive of Examples 1-3, comprising the following steps: S1. Add water, Fe2(SO4)3, and MgSO4 to the mixing reactor and stir until homogeneous.

[0048] S2. Add the modified starch to the mixing reactor and stir. Observe the ammeter reading of the stirring motor. In the initial stage of adding the modified starch, the current rises and then falls until the current stabilizes and no longer decreases.

[0049] S3. Add the remaining materials to the mixing reactor and stir until homogeneous.

[0050] The high-solids-content water-soluble starch adhesives of Examples 1-3 and Comparative Example 1 were used in the production line of three-layer packaging boxes. The boxes were pre-printed Class B, with a size of 1.08 x 0.525 = 0.567 m. The paper standard was 170 g white kraft paper + 130 g high-strength corrugated paper (B-flute) + 120 g kraft paper. After production, the basis weight, compressive strength, whether the thickness increased, and whether the deformation and moisture absorption of the paper were tested. The results are shown in Table 1 below.

[0051] Table 1 The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0052] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry, characterized in that, It is mainly made of the following ingredients: 100 parts by weight of modified starch Functional fillers 50 parts by weight to 450 parts by weight Surfactant 0.01 parts by weight to 10 parts by weight 3 to 20 parts by weight of fiber 10 to 30 parts by weight of desiccant and 120 to 200 parts by weight of water The weight is expressed in one of the following quantities: gram, kilogram, thousand kilogram, or ten thousand kilogram; The solid content of the high-solids-content water-soluble starch adhesive is ≥70wt%.

2. The high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry according to claim 1, characterized in that, The raw materials for making high-solids-content water-soluble starch adhesives suitable for the printing or packaging industry also include: Additives: 1 to 10 parts by weight.

3. The high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry according to claim 2, characterized in that, The additives are Fe2(SO4)3 and MgSO4, wherein MgSO4... 4 0.5 weight ~5 Parts by weight, MgSO 4 0.5 weight ~5 Parts by weight.

4. The high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry according to claim 2, characterized in that, The surfactant is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant.

5. The high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry according to claim 1, characterized in that, The surfactant is sodium dodecylbenzenesulfonate or dioctadecyl dimethylammonium chloride.

6. The high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry according to claim 1, characterized in that, The desiccant is an alcohol.

7. The high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry according to claim 1, characterized in that, The functional filler is one or more of calcium carbonate, bentonite, and kaolin.

8. The high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry according to claim 1, characterized in that, The fiber is one or more of wood fiber, paper fiber, or chemically synthesized fiber.

9. The high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry according to any one of claims 1-8, characterized in that, In the preparation process of the high solids content water-soluble starch adhesive suitable for the printing or packaging industry, after the modified starch is added, the ammeter reading of the stirring motor is observed. In the initial stage of adding the modified starch, the current of the stirring motor rises, then falls, until the current stabilizes and no longer falls, at which point subsequent materials are added.

10. A method for preparing a high-solids-content water-soluble starch adhesive suitable for the printing or packaging industry as described in any one of claims 1-8, characterized in that, Includes the following steps: S1, add water and additives to the mixing reactor and stir until homogeneous; S2, add the modified starch to the mixing reactor, stir, and observe the ammeter reading of the stirring motor. In the initial stage of adding the modified starch, the current of the stirring motor rises, then falls, until the current stabilizes and no longer decreases. S3. Add the remaining materials to the mixing reactor and stir until homogeneous.

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