阅读说明：本技术 一种复合纸用粘结剂及其制备方法 (Adhesive for composite paper and preparation method thereof ) 是由 曹鸽 罗勇 曹越 于 2019-11-21 设计创作，主要内容包括：本发明公开了一种复合纸用粘结剂及其制备方法,属于粘结剂技术领域。本发明的复合纸用粘结剂,主要由如下重量份数的原料制成：玉米淀粉352-448份、碱40-48份、硼砂5.6-7.2份、滑石粉22-28份；所述碱为氢氧化钠或者氢氧化钾。本发明的复合纸用粘结剂的制备方法,包括如下步骤：先将玉米淀粉与水混合均匀,然后加入硼砂混合均匀,然后加入碱混合均匀,然后加入滑石粉混合均匀,即得。本发明的复合纸用粘结剂具有较高的粘度,结合力强,且粘结剂中固含量较高,具有良好的稳定性,适宜长期存储。(The invention discloses a binder for composite paper and a preparation method thereof, belonging to the technical field of binders. The binder for the composite paper is mainly prepared from the following raw materials in parts by weight: 352 portions of corn starch and 448 portions, 40 to 48 portions of alkali, 5.6 to 7.2 portions of borax and 22 to 28 portions of talcum powder; the alkali is sodium hydroxide or potassium hydroxide. The preparation method of the adhesive for the composite paper comprises the following steps: mixing corn starch and water uniformly, adding borax, mixing uniformly, adding alkali, mixing uniformly, adding talcum powder, and mixing uniformly. The adhesive for the composite paper has high viscosity, strong binding force, high solid content in the adhesive, good stability and suitability for long-term storage.)

1. An adhesive for composite paper, characterized in that: the material is mainly prepared from the following raw materials in parts by weight: 352-448 parts of corn starch, 40-48 parts of alkali, 5.6-7.2 parts of borax, 22-28 parts of talcum powder and 880 parts of water; the alkali is sodium hydroxide or potassium hydroxide.

2. The adhesive for composite paper according to claim 1, wherein: the material is mainly prepared from the following raw materials in parts by weight: 376 portions of corn starch and 448 portions, 40 to 45 portions of alkali, 6.4 to 7.2 portions of borax, 22.5 to 25.6 portions of talcum powder and 820 portions of water and 880 portions; the alkali is sodium hydroxide or potassium hydroxide.

3. The adhesive for composite paper according to claim 1, wherein: the raw material also comprises 3.7-8.8 parts by weight of an oxidizing agent, wherein the oxidizing agent is at least one of hydrogen peroxide, sodium peroxide, potassium peroxide and potassium persulfate.

4. The adhesive for composite paper according to claim 1, wherein: the raw materials also comprise 23-32 parts by weight of filler and 5-10 parts by weight of dispersant, wherein the filler is at least one of zinc stearate, calcium stearate and barium stearate; the dispersant is urea.

5. The adhesive for composite paper according to claim 1, wherein: the raw materials also comprise 12-18 parts by weight of a moisture-proof agent and 2-5 parts by weight of a crosslinking assistant, wherein the moisture-proof agent is at least one of silicic acid, polyethylene wax and phthalic anhydride; the crosslinking assistant is glyoxal and/or glutaraldehyde.

6. The adhesive for composite paper according to claim 5, wherein: the raw material also comprises 1.5-2.2 parts by weight of ethyl cyanoacrylate adhesive.

7. The method for preparing the binder for composite paper according to any one of claims 1 to 6, wherein: the method comprises the following steps: mixing corn starch and water uniformly, adding borax, mixing uniformly, adding alkali, mixing uniformly, adding talcum powder, and mixing uniformly.

8. The method for preparing the adhesive for composite paper according to claim 7, wherein: mixing corn starch and water uniformly, namely mixing the corn starch and the water and stirring at the rotating speed of 10-20r/min for 20-30 min; adding borax, and mixing uniformly, stirring at rotation speed of 30-50r/min for 5-10 min.

9. The method for preparing the adhesive for composite paper according to claim 7, wherein: after the talcum powder is added and mixed evenly, the moisture-proof agent is added and stirred for 5-10min at the rotating speed of 30-80 r/min.

10. The method for preparing the adhesive for composite paper according to claim 7, wherein: adding a dispersant solution while adding the talcum powder, wherein the dispersant solution is a urea solution, and the mass fraction of the urea solution is 26-43%.

Technical Field

The invention relates to the technical field of adhesives, in particular to an adhesive for composite paper and a preparation method thereof.

Background

Currently in the field of packaging, the use of composite paper is increasing more and more, wherein the demand for composite cardboard for producing cartons is also increasing day by day, only domestically, and the demand for cardboard for producing cartons is approaching 7000 million tons per year. Along with the expansion of the use demand of the paper boards, the quality requirements of people on the paper boards are higher and higher, such as the strength, toughness, moisture resistance and the like of the paper boards, and meanwhile, the more rigorous requirements are provided for the environmental protection performance of the paper boards so as to avoid the influence on the human health.

In order to ensure that the influence of the paper board on human bodies is minimized, starch binders are adopted in the production of a plurality of paper boards. For example, the chinese patent application publication No. CN107384248A discloses a starch-based paperboard adhesive, which comprises starch, a solvent for dissolving starch and preparing starch slurry, an alkali solution and borax, wherein the alkali solution can adjust the pH of the starch slurry to 8-9. The starch adopted by the paperboard adhesive comprises amylose and amylopectin, the penetration force of the amylose and the gripping force of the amylopectin can be utilized to improve the adhesion effect, and the paperboard adhesive has the characteristics of environmental protection while the adhesion performance is ensured. However, the viscosity of the cardboard adhesive is still low, and the bonding requirement of high-end cardboard is difficult to meet.

Disclosure of Invention

In view of the disadvantages of the prior art, a first object of the present invention is to provide an adhesive for composite paper, which has a higher viscosity.

The second purpose of the invention is to provide a preparation method of the adhesive for the composite paper, which does not need heating and has simple process.

In order to achieve the first object, the invention provides the following technical scheme:

the binder for the composite paper is mainly prepared from the following raw materials in parts by weight: 352-448 parts of corn starch, 40-48 parts of alkali, 5.6-7.2 parts of borax, 22-28 parts of talcum powder and 880 parts of water; the alkali is sodium hydroxide or potassium hydroxide.

By adopting the technical scheme, in the raw materials of the binder for the composite paper, the corn starch has strong hygroscopicity, and the mixing time of the corn starch and water can be shortened in the process of preparing the binder. The alkali is sodium hydroxide or potassium hydroxide, can be used for gelatinizing the corn starch, has good permeability after the corn starch is gelatinized, and can improve the adhesive force of the adhesive. Sodium hydroxide or potassium hydroxide is used as a pasting agent, so that the pasting temperature can be reduced, heating is avoided, the preparation process is simplified, and energy is saved. Borax can be used as a cross-linking agent to generate a substance with a complex cross-linking structure in water, so that the cohesive force of the corn starch is improved. The addition of the talcum powder can increase the viscosity of the adhesive, reduce the fluidity of the adhesive and improve the processability of the adhesive.

The invention is further configured to: the material is mainly prepared from the following raw materials in parts by weight: 376 portions of corn starch and 448 portions, 40 to 45 portions of alkali, 6.4 to 7.2 portions of borax, 22.5 to 25.6 portions of talcum powder and 820 portions of water and 880 portions; the alkali is sodium hydroxide or potassium hydroxide.

By adopting the technical scheme, the proportion of the raw materials is further optimized, and the binder has higher solid content and higher viscosity.

The invention is further configured to: the raw material also comprises 3.7-8.8 parts by weight of an oxidizing agent, wherein the oxidizing agent is at least one of hydrogen peroxide, sodium peroxide, potassium peroxide and potassium persulfate.

By adopting the technical scheme, the corn starch can be oxidized by adding the oxidant, so that the groups on the corn starch are converted into carboxyl or aldehyde groups to obtain the modified starch, the gelatinization temperature of the corn starch is further reduced, and the stability of the prepared binder is improved. Moreover, the aldehyde group after oxidation can also improve the corrosion resistance of the binder. The amount of the oxidant added in the invention is small, so that only part of groups on the corn starch are oxidized, and the high permeability of the corn starch is ensured.

The invention is further configured to: the raw materials also comprise 23-32 parts by weight of filler and 5-10 parts by weight of dispersant, wherein the filler is at least one of zinc stearate, calcium stearate and barium stearate; the dispersant is urea.

By adopting the technical scheme, zinc stearate, calcium stearate and barium stearate are added as fillers, so that the viscosity of the binder can be further improved, and the quick-drying performance of the binder can be improved. In addition, the fillers also ensure that the prepared adhesive is not easy to delaminate or settle after long-term storage, and improve the stability of the adhesive. The urea is used as the dispersing agent, so that the dispersing uniformity of the raw materials in the mixing process can be improved, and the viscosity of the binder can be further improved by combining amino groups on the urea with groups on the corn starch.

The invention is further configured to: the raw materials also comprise 12-18 parts by weight of a moisture-proof agent and 2-5 parts by weight of a crosslinking assistant, wherein the moisture-proof agent is at least one of silicic acid, polyethylene wax and phthalic anhydride; the crosslinking assistant is glyoxal and/or glutaraldehyde.

By adopting the technical scheme, the silicic acid, the polyethylene wax and the phthalic anhydride are used as the moisture-proof agent, so that the moisture in the environment is prevented from invading into the binder and being combined with the corn starch in the use process of the binder, and the binding force of the binder is reduced. Glyoxal and glutaraldehyde are used as crosslinking aids, can be used as crosslinking agents to improve the bonding strength of the binder, can react with borax to generate polymers, and are combined with corn starch to form macromolecular complex crosslinking substances, so that the bonding strength of the binder is further improved, and the products have good high temperature resistance and improve the thermal stability of the binder.

The invention is further configured to: the raw material also comprises 1.5-2.2 parts by weight of ethyl cyanoacrylate adhesive.

By adopting the technical scheme, the added ethyl cyanoacrylate adhesive is dispersed in the solvent and can be fully combined with all raw materials, a firm cross-linked structure is formed after curing, and the adhesive strength of the adhesive for the composite paper can be greatly improved only by a small amount of ethyl cyanoacrylate adhesive.

In order to achieve the second object, the invention provides the following technical scheme:

the preparation method of the adhesive for the composite paper comprises the following steps: mixing corn starch and water uniformly, adding borax, mixing uniformly, adding alkali, mixing uniformly, adding talcum powder, and mixing uniformly.

By adopting the technical scheme, the corn starch is mixed with water firstly, so that the corn starch is expanded, the crosslinking and the gelatinization are convenient to carry out in the later period, the expanded corn starch is more easily combined with the borax, the chain of the starch is lengthened and becomes complex, and the viscosity of the binder is improved. After alkali is added for gelatinization, the groups on the starch are fully exposed, and after the talcum powder is added, the talcum powder particles can be fully combined with the groups on the starch, so that the viscosity of the binder is further improved.

The invention is further configured to: mixing corn starch and water uniformly, namely mixing the corn starch and the water and stirring at the rotating speed of 10-20r/min for 20-30 min; adding borax, and mixing uniformly, stirring at rotation speed of 30-50r/min for 5-10 min.

By adopting the technical scheme, the lower stirring speed is adopted when the corn starch is mixed with water, the stirring time is shorter, the full expansion of the corn starch is facilitated, and the crosslinking and gelatinization effects are improved. After the borax is added, stirring is carried out at a high speed for a short time, so that the borax is favorably and fully dispersed and uniformly distributed in the corn starch, and the phenomenon that the viscosity distribution is not uniform due to the excessive local unknown distribution of the borax is avoided.

The invention is further configured to: after the talcum powder is added and mixed evenly, the moisture-proof agent is added and stirred for 5-10min at the rotating speed of 30-80 r/min.

By adopting the technical scheme, after the moisture-proof agent is added, the moisture-proof agent is rapidly stirred at a higher stirring speed, and can be uniformly dispersed in the binder only in a short time, so that the cross-linked polymer structure of the binder is prevented from being damaged due to long-time stirring.

The invention is further configured to: adding a dispersant solution while adding the talcum powder, wherein the dispersant solution is a urea solution, and the mass fraction of the urea solution is 26-43%.

By adopting the technical scheme, the main component of the talcum powder is magnesium silicate, so that the talcum powder is not easy to disperse uniformly in a water phase, the dispersing agent is added when the talcum powder is added, the talcum powder is favorably and fully dispersed in the binder, and the urea serving as the dispersing agent can be well combined with the corn starch, so that the bonding strength of the binder is further improved.

In conclusion, the invention has the following beneficial effects:

first, the adhesive for composite paper has high viscosity, strong binding force, high solid content in the adhesive, good stability and suitability for long-term storage.

Secondly, the adhesive for the composite paper has good environmental adaptability, is suitable for being used in a high-temperature environment, and has good corrosion resistance.

Thirdly, the preparation method of the adhesive for the composite paper does not need heating, has simple process and energy conservation, and the prepared adhesive has uniform texture, convenient storage and high stability.

Detailed Description

The present invention will be described in further detail with reference to examples.

In the following examples, the corn starch is edible corn starch (830 kg/bag) from grain Biochemical energy marketing Co., Ltd in Jilin. The granularity of the borax used in the invention is 80-120 meshes. The particle size of the talcum powder is 325-800 meshes.

In the preparation method of the adhesive for composite paper, the preparation environment is normal temperature and normal pressure, and the preparation method is only required when the temperature is normal room temperature (about 25 ℃). Preferably, the adhesive for composite paper of the present invention is an adhesive for composite corrugated cardboard. The stirring speed of the corn starch and the water is 10-20r/min, and the stirring time is 20-30 min. The stirring speed after the borax is added is 30-50r/min, and the stirring time is 5-10 min. The stirring speed after the sodium hydroxide is added is 50-80r/min, and the stirring time is 5-10 min. When the sodium hydroxide is added, a sodium hydroxide solution is added, namely the sodium hydroxide is prepared into a sodium hydroxide solution before the sodium hydroxide is added, and the mass fraction of the sodium hydroxide solution is 10-40%. Adding an oxidant before adding the borax, and stirring for 5-10min at a stirring speed of 80-120r/min after adding the oxidant.

The stirring speed after the mixture is added is 20-30r/min, and the stirring time is 10-20 min. The stirring speed after the moisture-proof agent is added is 30-80r/min, and the stirring time is 5-10 min.

Adding alkali and mixing uniformly to obtain a premixed glue solution, adding talcum powder and a dispersing agent at the same time, mixing uniformly the talcum powder and a urea solution to obtain a mixture, and then adding the mixture into the premixed glue solution. The mass fraction of the urea solution is 26-43%.