Method for preparing rapid-dry corn starch adhesive

Abstract

The invention discloses a manufacturing method for dry core starch adhesives, the method uses new catalyst Fe2+, reduces the use quantity of oxidant to 5%A, reduces the reaction time to 30 minutes, and produces a kind of cheap and high adhesives starch adhesives. The method adds in modified bentonite or natrium group bentonite whose weight is 30% of dried starch as the fillers before adding in NaOH, it enhances the drying speed greatly. The adhesives can be dried quickly, it doesn't counter tide, high rigidity. The cost is reduced greatly, the dry speed is enhabced greatly.

Description

technical field [0001] The invention belongs to the modification technology of natural polymers, and relates to a water-based adhesive or an adhesive used for bonding paper products such as cartons and cartons, in particular to a preparation method of a corn starch adhesive. Background technique [0002] The existing corn starch adhesives are basically made from oxidized starch as raw material through NaOH solution gelatinization. Most of its production process is as figure 1 As shown, that is to add water to cornstarch to make starch milk, stir and add oxidant (about 10%), react at a certain temperature for a long time (6h~8h), then filter, dry, add NaOH solution to gelatinize, and make into Starch binder, the solid content is generally 20% to 25%. [0003] In the preparation process of oxidized starch, the preparation process of pure oxidized starch has been used for a long time, and no new process has been specially developed for the production of oxidized starch for st...

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Problems solved by technology

[0003] In the preparation process of oxidized starch, the preparation process of pure oxidized starch has been used for a long time, and no new process has been specially developed for the production of oxidized starch for starch adhesives, which has led to two problems: the first is the production of oxidized starch For starch, the amount of oxidant is large, the reaction time is very long (manpower and power consumption are large); the viscosity is not very large after gelatinization, in order to ensure the bonding strength, the solid content of the adhesive has to be increased; these factors lead to the final production of Starch adhesives are expensive and difficult to be accepted by the market

The second problem is that the existing starch adhesives have a slow drying speed, which is not suitable for the small-scale production and fast-release products of carton manufacturers in my country.

[0004] At present, the most commonly used sodium silicate adhesive in my country's carton industry has the advantages of fast drying speed and low cost of use (compared to the existing starch adhesive products), but it is easy to get damp, and its stiffness is not as good as starch adhesive. Because of the high alkalinity of this kind of adhesive, it is easy to cause pollution to the contents of the package. It belongs to the product that is phased out by the national policy. The developed countries in foreign countries have basically eliminated the sodium hydroxide as early as 20 or 30 years ago. Adhesives, the Chinese government has already stipulated that the packaging cartons for export commodities must not use sodium silicate adhesives

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