WO2018027287A1

WO2018027287A1 - Pressure-sensitive edible sheet adhesive, method for preparing a pressure-sensitive sheet adhesive, and use

Info

Publication number: WO2018027287A1
Application number: PCT/BR2016/000156
Authority: WO
Inventors: Tanara SARTORI; Florencia Cecilia MENAGALLI
Original assignee: Universidade Estadual De Campinas - Unicamp
Priority date: 2016-08-12
Filing date: 2016-12-21
Publication date: 2018-02-15
Also published as: BR102016018507B1; BR102016018507A2

Abstract

The present invention describes a pressure-sensitive edible adhesive. The pressure-sensitive adhesive proposed is composed of an edible adhesive fraction applied onto a support material, which may likewise be edible, obtained from biopolymers. The pressure-sensitive edible adhesive is formulated from protein, plasticizer, ethanol and water and does not require additional steps for adhesion. It is an adhesive composed of edible, biodegradable materials and possesses a high level of biodegradabililty.

Description

EDIBLE PRESSURE SENSITIVE STICKER, METHOD FOR PREPARATION OF IAMINATE PRESSURE SENSITIVE ADHESIVE, AND USE Field of the Invention:

[1]. The present invention is in the field of Engineering, more precisely in the field of food engineering, and describes an edible laminate pressure sensitive adhesive, the method of obtaining said adhesive and the use thereof.

Background of the invention:

[2] The use of glues and adhesives is widespread in many areas, both in everyday activities and industrially.

[3] Adhesives may be classified according to their physical and chemical properties and their conditions of use. Among the various types of adhesives are hot melt adhesives, solvent based adhesives (white glue), emulsified adhesives, pressure sensitive adhesives, multi-component adhesives (require chemical reaction to adhere) and adhesives. single component (requires external energy to adhere to).

[4] Pressure sensitive adhesives, commonly known as PSA, Pressure Sensitive Adhesive, are self-adhesive materials that can instantly adhere to substrates to which they are applied from light pressure (with finger, for example). They are mostly composed. by an elastomer and a resin, which give adequate adhesion characteristics to PSAs. The main advantage of this type of adhesive is its ability to adhere to materials at room temperature without the need for activation with water, solvents, heat or radiation, thus differing from other existing adhesive forms. [5] PSAs should be adequately flexible in order to. adapt to rough surfaces; sufficient spreadability on the surfaces (substrates) to which they will be applied, thus providing adequate adhesion; and, they must have sufficient internal force to. Do not leave residues on the substrates when detaching. Thus, obtaining this type of adhesive becomes challenging due to its contradictory characteristics and the difficulty in establishing quantitative relationships between its composition and its rheological and adhesive properties.

[6] Adhesives made from edible materials are emerging as a new trend in the development of various food technologies. Due to the characteristics of edible compounds and the complexity presented by adhesives, few products and researches in this area are found.

[7] Document PI0709683-6 describes edible adhesive coatings for multi-component food products. These coatings are considered adhesive because they have the ability to join a core to particulate systems. Thus, in reality, it consists of a heated edible covering over a core. Then the covered nucleus is brought into contact with particles which adhere to it. The set needs to be cooled for permanent adhesion. The proposed invention differs from said document, mainly in that the proposed adhesive consists of an edible Pressure Sensitive Adhesive (PSA), which does not require additional steps for adhesion. In addition, the proposed invention does not comprise fat, thus dispensing hot application of the material. [8] The technology described in US3607370 relates to the development of a pressure sensitive adhesive tape composed of hydrolyzed gluten as an internal plasticizer, ethylene oxide, hydroxyethyl methacrylate and tert-butyl peroxide. Thus it differs from the proposed invention mainly because the adhesive described in the above document is a low biodegradable and inedible chemical adhesive as the components of the formula have high toxicity and carcinogenic properties. high biode.gradability, the fact that it is edible and the ease of obtaining. Moreover, the method of obtaining the proposed invention is much simpler as it does not use toxic materials and the time to obtain the final product is much shorter than that given in the indicated patent document.

[9] US5827553 refers to an edible adhesive coating which may contain seasonings and is applied to foods in. liquid state by spraying. A. Formulation is composed of hydrolyzed starch, alcohol, polymerized glycol and water. As technology concerns an adhesive cover, it is difficult to use to adhere materials to each other. In addition, the adhesive coating needs drying after application, which is a disadvantage as it requires an additional adhesion process which could make some instant applications unfeasible. The proposed invention, on the other hand, relates to a pressure sensitive adhesive with which materials can be adhered to each other, and no additional adhesion step is required,

[10] US2014105958 describes the general structural shape of an edible tape that could carry nutrients. Said document does not specify the process to employ nor the formulation of the components. The proposed invention differs since an edible pressure sensitive adhesive formulation has been developed and defined.

[11] Thus, the development of pressure sensitive adhesives is very complex and these are not yet food-grade due to the difficulty in finding food-grade materials with specific adhesion and cohesion properties, or to formulate materials with these characteristics. . In this context, an edible pressure sensitive adhesive has been developed.

Brief Description of the Invention:

[12] The present invention relates to a laminate pressure sensitive adhesive comprising a backing material and a biodegradable edible PSA comprising glute, glutenin or gliadin, plasticizer and water.

[13] In addition, the method of preparing the laminated edible PSA comprising the steps of mixing gluten or glutenin or gliadin is described. and a plasticizer in hydrous ethanol; heating under stirring the obtained mixture; applying the obtained heated adhesive solution on a support material; dry the obtained product; obtaining the edible laminate pressure sensitive adhesive. When the protein used is gluten, the method of preparing the laminated edible PSA comprises the steps of mixing gluten in. absolute ethanol; solubilizing a plasticizer, preferably glycerol, in water; mix the two fractions obtained in the previous steps; heating under stirring the obtained mixture; applying the adhesive solution obtained in the still heated on a support material; dry the obtained product to obtain the pressure sensitive edible laminate adhesive. Short description of the figure:

[14] In order to obtain a complete and complete view of the object of this invention, a figure is presented to which reference is made as follows.

[15] Figure 1 represents the edible pressure sensitive adhesive (1) applied to the also edible support material (2).

Detailed Description of the Invention:

[16J] The present invention discloses a laminate pressure sensitive adhesive comprising a biodegradable edible PSA and a carrier material.

[17] The biodegradable edible PSA comprises 1.0 to 55% gluten or glutenin or gliadin, preferably 25% gluten; 15 to 25% of a plasticizer, preferably 25%; and 25 to 75% water, preferably 50%.

[18] The plasticizer is selected from the group comprised of glycerol or sorbitol, preferably glycerol. The ratio of gluten or glutenin or gliadin to plasticizer if _. 1: 0.4 to 1: 1.4, preferably 1: 1.

[19] The adhesive comprises edible and biodegradable materials, therefore it is highly biodegradable and has no petroleum derivatives in its composition.

[20] The proposed PSA can be laminated onto a biopolymer based support material such as protein and polysaccharides, properly cross-linked, forming the laminated PSAs (Figure 1). The films may be of polysaccharides or proteins, which must be properly cross-linked and added with plasticizer. The concentration dc>. piasjt if ^'i' antipode vary, but preferably should be above 100% by weight . relation to the biopolymer. [21] Preferred carrier material comprises 23 to 43% w / w pectin, preferably 30% w / w. 35 to 57% w / w glycerol, preferably 45% w / w, 15 to 30% w / w, preferably 25% w / w, and is edible and biodegradable.

[22] The steps of the method of preparing the laminated edible PSA depend on the protein selected.

[23] The method of preparation of edible laminated PSA applicable to gluten, glutenin or gliadiana comprises the following steps:

a.) mix 2% to 20% w / w, preferably. 7% w / w, gluten or glutenin or gliadin and 0.9% at 26% w / w, preferably 7% w / w, of a plasticizer in 52% to 97.2% w / w, preferably 86% . w / w hydrous ethanol at a concentration of 50 to 70% w / w;

b) heating with stirring the mixture obtained in (a) at a preferential temperature of 70 ° C;

c) applying the adhesive solution obtained in step (b) still heated on a support material, being through the sub step cl or c.2:

cl.) preferably atomizing the adhesive solution obtained in (b) onto a support material in a batch, continuous and semi-continuous regime;

c.2) preferably laminar with the adhesive solution obtained in (b) on a support material in. a continuous and semi-continuous batch regime;

d) drying the product obtained in (c) to preferably 40 ° C and 40% RH, yielding the pressure sensitive edible laminate adhesive.

1.24] The method comprises, between steps (a) and (b), a step of adjusting ph to 5.0 with 0.1 acetic acid solution M when the protein used is glutenin.

[25] The method may further comprise a printing step no. support material between steps (b) and {c}.

[26] When the selected protein is gluten, another method may be used. This other method of preparing the edible pressure sensitive laminate adhesive comprises the following steps:

a) mix. 4% to 44% w / w, preferably 14% w / w gluten in 56% to 96% w / w, preferably 86% w / w, of absolute ethanol;

b) solubilizing 2% to 52% w / w, preferably 14% w / w, of a plasticizer, preferably glycerol, in 48% to 98% w / w, preferably 86% w / w, of water;

c) mixing the two fractions obtained in steps (a) and (b) in the ratio of 1: 0.8 to 1: 1.2, preferably 1: 1;

d) heating under stirring the mixture obtained in step (c) to a preferred temperature of 70 ° C;

e) applying the adhesive solution obtained in step (d) further heated on one. support material being through step e.l or e.2;

e.l) preferably atomizing the adhesive solution obtained in (d) onto a support material in a batch, continuous and semi-continuous regime;

e.2) preferably laminar with the adhesive solution obtained in step (d) on a support material in a batch, continuous and semi-continuous regime;

f) drying the product obtained at (e) to preferably 40 ° C and 40% RH, yielding the pressure sensitive edible laminate adhesive.

[27] The method may further comprise a step of printing on the backing material between steps (d) and (e).

[28] The proposed laminated PSA may be added with antioxidants, preferably water soluble antioxidants such as ascorbic acid, in order to increase its shelf life. The antioxidant concentration may be from 0.1 to 5%, but preferably 1%.

[29] The proposed laminated PSA requires no additional process to adhere to the most diverse substrates and can be ingested with food, being useful in the application of decorative adhesive figures, bar code application and expiration date directly on the food. food applications.

Embodiment Examples:

[30] The examples shown here are intended only to exemplify the ways of carrying out the invention without, however, limiting it. Accordingly, various modifications, adaptations, variations, substitutions, combinations and equivalents may be practiced without departing from the scope of the invention as set forth in the claims.

Example 1: Gluten

[31] Laminated pressure-sensitive edible adhesive comprising a biodegradable gluten-based edible PSA composed of 25% gluten, 25% glycerol as plasticizer, and 50% water based mass and a Pectin based support composed of 30% pectin, 45% glycerol and 25% water based on mass.

[32] The obtained laminated adhesive was submitted to texture analyzer adhesiveness tests, obtaining adhesion strength, adhesion work and cohesiveness data. This test consists of a probe that moves until it contacts the surface. of the adhesive, with a certain force for a short time and then returns at a certain speed, generating force results as a function of distance. Thus, the laminated adhesive obtained has the following properties, as shown in Table 1: Adhesive strength of 5 N and adhesion work of 0.3 N / mm. The distance to. The separation between the probe and the adhesive is. relative to cohesiveness, and the greater the distance, the lower the cohesiveness. An adhesive PSA must have high cohesiveness. The separation distance was 0.1 mm, ie, good cohesiveness.

Example 2: Glutenin

[33] Laminated pressure sensitive edible adhesive comprising a biodegradable glutenin-based edible P.SA composed of 20% glutenin, 20% glycerol as a plasticizer, and 60% water on a mass basis, and a 30% pectin based support. in. pectin, 45% glycerol and 25% water, on a mass basis.

[341 The laminated adhesive obtained was subjected to texture analyzer adhesion tests, obtaining adhesion strength, adhesion work and cohesiveness data. This test consists of a probe that is moved until it contacts the surface of the adhesive with a certain force for a short time and then returns at a certain speed, generating force results as a function of distance. Thus, the laminated adhesive obtained ^: has the following properties, as shown in Table 1: Adhesive strength of 12 N and adhesion work of 1.8 N / mm. The distance to. The separation between probe and adhesive is relative to cohesiveness, and the greater the distance, the lower the cohesiveness. An adhesive PSA must have high cohesiveness. The separation distance was 0.4 mm, ie Good cohesiveness.

Example 3: Gliadin

[35] Laminated pressure sensitive edible adhesive comprising a biodegradable gliadin edible PSA composed of. 22.5% gliadin, 22.5% glycerol as a plasticizer, and 55% water on a mass basis and a pectin-based support material consisting of 30% pectin, 45% glycerol and 25% of water on a mass basis.

[36] The laminated adhesive obtained was submitted to texture analyzer adhesiveness tests, obtaining adhesion strength, adhesion work and cohesiveness data. This test consists of: a probe that is moved until it contacts the surface of the adhesive with a certain force for a short period of time and then returns at a certain speed, generating force results as a function of distance. Thus, the laminated adhesive obtained has the following properties, as shown in Table 1: Adhesive strength 9 N and adhesion work 1.7 M / mm. The distance to separation between probe and adhesive is relative to cohesiveness, and the longer the distance, the lower the cohesiveness. An adhesive PSA must have high cohesiveness. The separation distance was 1.2 mm, ie, good cohesiveness.

Table 1 - Bond strength, bond work and separation distance of laminated PSAs comprising a gluten, glutenin or gliadin based adhesive, and a pectin based support material Example 4: Method

[37] The edible PSA preparation method comprising the following steps:

(a) mix 7% w / w gliadin and 7% w / w glycerol in 86% w / w ethanol, hydrated at a concentration of 70% w / w;

b) heating with stirring the mixture obtained in (a) at a temperature of 70 ° C;

c) apply the adhesive solution obtained on. step (b) further heated on a support material by atomizing the adhesive solution obtained in (b) on a support material, - d) drying the obtained product ^: (c) at 40 ° C and 40% RH to give the pressure sensitive edible laminate adhesive.

Example 5: Method

[38] Method of preparing the edible pressure sensitive laminate adhesive comprising the following steps:

a) mixing 14% w / w gluten in 86% w / w absolute ethanol; B). solubilize 14% w / w glycerol in 86% w / w water;

c) mix the two fractions obtained in steps (a) and (b) in a 1: 1 ratio;

d) heating under stirring the mixture obtained in step (c) to a temperature of 70 ° C;

e) applying the adhesive solution obtained in step (d) still heated on a support material by laminating with the adhesive solution obtained in step (d) on a support material;

f). drying the product obtained in (e) at 40 ° C e. 40% RH to obtain the pressure sensitive edible laminate adhesive.

Claims

Pressure sensitive laminate adhesive comprising a backing material and a biodegradable edible PSA comprising gluten or glutenin or gliadin, a plasticizer selected from glycerol or sorbitol and water.

Pressure sensitive laminate adhesive according to Claim 1, characterized in that the carrier material is preferably selected from films based on cross-linked biopolymers.

3. A pressure sensitive laminate adhesive which is edible and biodegradable, comprising a backing material comprising 23 to 43% w / w pectin, 35 to 57% w / w glycerol, and 15 to 30% w / w Water; and a biodegradable edible PSA comprising 10 to 55% w / w gluten or glutenin or gliadin, 15 to 25% w / w of a plasticizer selected from the group comprised of glycerol or sorbitol and 25 to 75% w / w water.

Edible and biodegradable pressure sensitive laminate adhesive comprising a backing material preferably comprising 30% w / w pectin, preferably 45% w / w glycerol and preferably 25%. w / w water; and a biodegradable edible PSA preferably comprising 25% w / w gluten, preferably 25% w / w glycerol and preferably 50% w / w water.

Adhesive according to Claim 3 or 4, characterized in that it comprises antioxidants, preferably water soluble, in a concentration of 0.1 to 5%, preferably 1%.

Adhesive according to Claim 5, characterized in that the ratio of gluten or glutenin or gliadin to plasticizer is 1: 0, 4 to 1: 1.4, preferably 1: 1.

Method of preparing the edible pressure sensitive laminate adhesive comprising the following steps:

a) mixing gluten or glutenin or gliadin and a plasticizer in hydrous ethanol;

b) heating with stirring the mixture obtained in (a);

c) applying the adhesive solution obtained in step (b) still heated on a support material being through step cl or c> 2:

c) preferably atomizing the adhesive solution obtained in (b) onto a support material in a batch, continuous and semi-continuous regime;

c.2) preferably laminar with the adhesive solution obtained in (b) on a support material in a batch, continuous and semi-continuous regime;

d) drying the product obtained in (c) to obtain the pressure sensitive edible laminate adhesive.

8. Method according to a. claim 7, characterized in that in step (a), the protein selected from gluten, glutenin and gliadin is between 2% to 20% m / m, preferably 7% m / m.

Method according to claim 7, characterized in that in step (a) the hydrous ethanol is between 52% to 97.2% w / w, preferably.86% w / w.

Method according to claim 7, characterized in that in step (a) hydrous ethanol has a concentration of 50 to 70% w / w,

Method according to claim 7, characterized in that in step (a) the plasticizer is preferably glycerol between 0.8% to 28% w / w, preferably 7% w / w.

Method according to claim 7, characterized in that it comprises, between steps (a) and (b), a step of adjusting ph to 5.0 with 0.1 M acetic acid solution when the protein used for glutenin ..

Method according to claim 7, characterized in that in step (b) the temperature is preferably 70 ° C.

Method according to Claim 7, characterized in that step (d) is preferably at 40 ^° C and 40 ° RH.

Method according to claim 7, characterized in that a printing step on the carrier material can be comprised between steps (b) and (c).

16. Method of preparing the edible pressure sensitive laminated adhesive comprising the following steps:

a) mix, gluten in absolute ethanol;

B). solubilize a plasticizer in water;

c) mixing the two fractions obtained in steps (a) and (b); d) heating under stirring the mixture obtained in step (c); e) applying the adhesive solution obtained in step (d) still heated on a support material being through sub step el or e.2: el) preferably atomizing the adhesive solution obtained in (d) onto a support material in a batch, continuous and semi-continuous regime;

e.2) preferably laminar with a. adhesive solution obtained in step (d) on a support material in a batch, continuous and semi-continuous regime;

f) drying the product obtained in (e) to obtain the pressure sensitive edible laminate adhesive.

Method according to claim 16, characterized in that it may comprise a step of printing on the carrier material between steps (d) and (e).

Method according to claim 16, characterized in that in step (a) the gluten is between 4% to 44% w / w, preferably 14% w / w.

19 .. Method _. according to claim 16, characterized in that in step (&) the absolute ethanol is between 56% to 96% w / w, preferably 86% w / w.

Method according to claim 16, characterized in that in step (b). the plasticizer is preferably glycerol between 2% to 52% w / w, preferably 14% w / w and the water be between 48% a. 98¾ m / m, preferably 86% m / m.

21. A method according to claim 16, characterized in that in step (c) the fractions of steps _(a.) And (b) are mixed in. ratio, from 0.8 to 1: 1.2, preferably 1: 1.

Method according to claim 16, characterized in that in step (c) the ratio of water to ethanol is 1: 1.

A method according to claim 1, characterized in that in step (d) the temperature is preferably 70 ° C.

Method according to claim 16, characterized in that step (f) is preferably at 40 ° C and 40% UB.

Use of the adhesive as described in claims 2 to 3. characterized in that it is preferably applied to food.