CN114350217B - Barrier coating, preparation method thereof and recyclable paper - Google Patents

Abstract

The invention discloses a barrier coating, a preparation method thereof and recyclable paper. The barrier coating comprises the following composition: acrylic emulsion, deionized water, polyethylene glycol furan dicarboxylate, hydrogenated polydecene, a dispersing agent, a wetting agent and a defoaming agent. The intrinsic viscosity of the polyethylene furan dicarboxylate is controlled between 0.2 and 0.4 dL/g. Can realize excellent barrier property and excellent anti-blocking property of a single coating, and has recyclability. The problems that the existing material cannot be recycled and the construction is complex are solved.

Description

Barrier coating, preparation method thereof and recyclable paper

Technical Field

The invention relates to a packaging technology, in particular to a barrier coating, and specifically relates to a barrier coating for recyclable paper.

Background

With the increasing severity of plastic pollution, countries around the world continue to develop a series of plastic regulation. The national institute of development and reform, and the ministry of ecological environment, jointly published opinions on further enhancement of plastic pollution control. As shown by the year 2020, china has the first time to forbid and limit the production, sale and use of partial disposable plastic products in partial regions and partial fields. The european union banned the use of 10 types of disposable plastic articles such as disposable tableware, glasses, plates and plastic swabs. This ban was fully implemented in 2021. It is intended to ensure that all plastic packages are reusable or recyclable by 2030. Patent No. CN 11065656543A discloses an environment-friendly laminating paper for containing cold drinks, which adopts polyolefin resin dispersoid, PLA and PBS as barrier coatings, but although the polyolefin resin dispersoid, PLA and PBS can be degraded, the coated paper can not be pulped any more, and the paper recovery is influenced.

CN201880082913.9 discloses a barrier film, a laminated packaging material comprising the film and a packaging container made thereof which achieve good gas and water vapour barrier properties using polyethylene furandicarboxylate as a barrier coating instead of aluminium foil, but the use of polyethylene furandicarboxylate alone as a barrier coating would lead to difficult repulping of the paper, also affecting paper recycling.

In the ninth book of discussions of the cosmetic science of China (mentioned in the introduction) (P169-183), it is mentioned that hydrogenated polydecene is used as an emollient for improving skin feel in the document "novel multifunctional liquid polymer for high performance skin care system".

CN201780079885.0, CN201880038343.3 and CN201980014270.9 disclose that two layers of coatings are prepared by using styrene-acrylic acid emulsion, which are water-resistant, oil-resistant and adhesion-resistant, but the double layers of coatings are complex in process and energy consumption is increased in the coating process; in addition, the acrylic emulsion is singly used as a barrier coating, the barrier property of the coating is poor, and the water resistance and the oil resistance cannot meet the actual application requirements. The market still needs a product which is coated in a single way, can be recycled and has excellent barrier property.

Disclosure of Invention

The invention discloses a barrier coating, a preparation method thereof and recyclable paper. Can realize excellent barrier property and excellent anti-blocking property of a single coating, and has recyclability. The problems that the existing material cannot be recycled and the construction is complex are solved.

A barrier coating comprising the following composition: based on barrier coating weight

The acrylic emulsion is in food contact grade, the lowest film-forming temperature is less than 20 ℃, the molecular weight is 50000-500000, the solid content is 30-60%, and the acid value is 5-40mgKOH/g. Suitable examples include, but are not limited to, those selected from Wanhua chemistry

Disemann' s

And so on.

The intrinsic viscosity of the polyethylene glycol furan dicarboxylate is controlled between 0.2 and 0.4 dL/g. Suitable products include, but are not limited to, PEF30 and Dagter 90 of the Nippon Material of Chinese academy of sciences. If the intrinsic viscosity of polyethylene furandicarboxylate is less than 0.2, the barrier property is affected, and if the intrinsic viscosity is more than 0.4, the recycling property is affected.

The hydrogenated polydecene has the CAS number of 68037-01-4 and the boiling point of over 316 ℃. Selected from existing products of Yongkuo technology and Koita chemical industry.

The dispersant of the present invention is a polyacrylic acid ammonium salt or sodium salt dispersant, and suitable examples include, but are not limited to, wolkel Germany

HLD-69, BYK-190 of Pico chemical.

The antifoam agent of the present invention is a polyether siloxane based antifoam agent, suitable examples include, but are not limited to, AIRASE-5355, foamaster WO 2360 by Pasteur, and the like.

The wetting agent of the present invention is a polyether siloxane, suitable examples include, but are not limited to BYK-346, BYK-348 from Pico chemical.

A method of making a barrier coating of the present invention comprises the steps of:

(1) Adding polyethylene glycol furandicarboxylate, hydrogenated polydecene and a dispersing agent into a dispersion tank, heating to 60-90 ℃, adding water for dispersing for 10-15min, and cooling to room temperature;

(2) And adding the acrylic emulsion into the blend under the condition of stirring, and sequentially adding a wetting agent and a defoaming agent to obtain the product.

The construction mode of the barrier coating is scraper coating or roller coating. Baking at 80-140 deg.C for 20-40s, and rolling and packaging the paper after baking. The coating weight of the dry film is 6-20g/m ² . Coating a substrate: 150-350g/m ² White cardboard.

The barrier coating can be used for a barrier coating system of paper cup paper and hamburger paper.

The molecular weight in the invention is number average molecular weight.

Compared with the prior art, the invention has the following advantages:

the invention creatively adopts the acrylic emulsion with the lowest film-forming temperature less than 20 ℃ to match the polyethylene glycol furan dicarboxylate with the intrinsic viscosity controlled between 0.2 dL/g and 0.4 dL/g. The acrylic emulsion has excellent film forming property and strength, and the polyethylene glycol furandicarboxylate can improve the barrier property of the formed film due to the strong polar structure of the polyethylene glycol furandicarboxylate. Meanwhile, in the paper repulping process, the film forming mechanism of the acrylic emulsion is mutual entanglement of molecular chain segments, the coating can be disintegrated under the action of strong external force, the recovery cannot be influenced, and the polyethylene glycol furandicarboxylate with smaller molecular weight can also be disintegrated along with the paper breakage due to weaker strength.

The invention creatively adopts hydrogenated polydecene, and the component can be used as a system solvent in the emulsification process of the polyethylene glycol furandicarboxylate to dissolve the polyethylene glycol furandicarboxylate and reduce the dispersion viscosity. On the other hand, the coating can be used as a plasticizer in the film forming process of the coating to promote the fusion of the acrylic latex particles and the polyethylene glycol furan dicarboxylate to form a coating with better barrier property. The residual olefin component migrates upward after the coating dries, improving the anti-blocking and slip properties of the coating.

By compounding the acrylic emulsion, the polyethylene glycol furandicarboxylate and the hydrogenated- (1-decene tetramer and 1-decene trimer), the excellent barrier property and excellent anti-blocking property of a single coating can be realized, and the coating has recyclability. The problems that the existing material cannot be recycled and the construction is complex are solved.

Drawings

FIG. 1 is a pulp slurry obtained by beating the paper of example 1.

Detailed Description

The method according to the invention will be further illustrated by the following examples, but the invention is not limited to the examples listed, but also encompasses any other known modification within the scope of the claims.

Example 1

(1) 10 parts of PEF-30 parts of hydrogenated polydecene and 2 parts of BYK-190 are added into a dispersion tank, heated to 70 ℃, dispersed by adding 12.5 parts of water, and cooled to room temperature.

(2) 70 parts of

Adding the mixture into the mixture under stirring, and sequentially adding 0.3 part of BYK-346 and 0.2 part of AIRASE-5355 to obtain the finished product.

Substrate: 250g/m ² White cardboard, coating mode: blade coating and drying conditions: 100 ℃ for 30s. Coating weight: 12g/m ² 。

Example 2

(1) 5 parts of Dagat-90,5 parts of hydrogenated polydecene, 1 part

HLD-69 was added to the dispersion tank, heated to 90 deg.C, dispersed by the addition of 8.7 parts of water, and cooled to room temperature.

(2) 80 parts of

The mixture is added into the mixture under the stirring condition, 0.2 part of BYK-348 and 0.1 part of Foamaster WO 2360 are sequentially added, and then the material can be discharged.

Substrate: 250g/m ² White cardboard, coating mode: blade coating and drying conditions: 80 ℃ for 40s. Coating weight of the base coat: 6g/m ² 。

Example 3

(1) Adding 8 parts of Dagote-90, 2 parts of hydrogenated polydecene and 1 part of BYK-190 into a dispersion tank, heating to 60 ℃, adding 13.5 parts of water for dispersion, and cooling to room temperature.

(2) 75 parts of

Adding the mixture into the mixture under stirring, and sequentially adding 0.3 part of BYK-348 and 0.2 part of AIRASE-5355 to obtain the final product.

Substrate: 250g/m ² White cardboard, coating mode: blade coating and drying conditions: 120 ℃ for 30s. Coating weight of the base coat: 20g/m ² 。

Comparative example 1

(1) Adding 2 parts of hydrogenated polydecene and 1 part of BYK-190 into a dispersion tank, heating to 60 ℃, adding 21.5 parts of water for dispersion, and cooling to room temperature.

(2) 75 parts of

Adding the mixture into the mixture under stirring, and sequentially adding 0.3 part of BYK-348 and 0.2 part of AIRASE-5355 to obtain the finished product.

Substrate: 250g/m ² White cardboard, coating mode: blade coating and drying conditions: 120 ℃ for 30s. Coating weight of the base coat: 20g/m ² 。

Comparative example 2

(1) Adding 8 parts of Dagote-90, 2 parts of hydrogenated polydecene and 1 part of BYK-190 into a dispersion tank, heating to 60 ℃, adding 13.5 parts of water for dispersion, and cooling to room temperature.

(2) 75 parts of

Adding the mixture into the mixture under stirring, and sequentially adding 0.3 part of BYK-348 and 0.2 part of AIRASE-5355 to obtain the finished product.

Substrate: 250g/m ² White cardboard, coating mode: blade coating and drying conditions: 120 ℃ for 30s. Coating weight of base coat: 20g/m ² 。

Comparative example 3

(1) Adding 8 parts of Dagaote-90, 1 part of BYK-190 into a dispersion tank, heating to 60 ℃, adding 15.5 parts of water for dispersion, and cooling to room temperature.

(2) 75 parts of

Adding the mixture into the mixture under stirring, and sequentially adding 0.3 part of BYK-348 and 0.2 part of AIRASE-5355 to obtain the final product.

Substrate: 250g/m ² White cardPaper, coating method: blade coating and drying conditions: 120 ℃ for 30s. Coating weight of the base coat: 20g/m ² 。

Comparative example 4

Heating to 200 deg.C for melting with Tahita-99 with desired chemical molecular weight and limiting intrinsic viscosity to 0.55-0.65dL/g, and coating on white cardboard

Substrate: 250g/m ² White cardboard, coating mode: blade coating and drying conditions: and (5) naturally cooling. Coating weight of the base coat: 15g/m ² 。

Beating test (reference method PTS-RH 021/97)

The following method is adopted:

(1) Taking 50g of paper coated with the coating by dry weight, and cutting the paper into 2 x 2cm sheets;

(2) Adding 575g of water into an SKZ1025 laboratory grinder, and defibering at 40 ℃ and 3000r/min for 20min;

(3) Passing the pulp through a mechanical pulp and fragment content analyzer P40175 and a sieve with the diameter of 0.7mm, filtering for 5 minutes, and completely drying and weighing the obtained pulp;

(4) If the mass of the obtained substance is >25g, the disintegration is considered to have passed. If the mass obtained is <25g, beating is not passed.

The properties are shown in Table 1.

TABLE 1 evaluation results of the Barrier coating Properties

It can be seen from the above examples and comparative examples that by compounding the acrylic emulsion, polyethylene furandicarboxylate and hydrogenated polydecene, excellent barrier properties and excellent anti-blocking properties of a single coating can be achieved without affecting the recyclability of the paper.

Claims (12)

1. A barrier coating comprising the following composition: based on barrier coating weight

The lowest film-forming temperature of the acrylic emulsion is less than 20 ℃, the molecular weight is 50000-500000, the solid content is 30% -60%, and the acid value is 5-40mgKOH/g; the intrinsic viscosity of the polyethylene furan dicarboxylate is controlled between 0.2 and 0.4 dL/g.

2. The barrier coating of claim 1, wherein the acrylic emulsion is selected from Wanhua chemical

0501 and/or Disemann

A-2092。

3. The barrier coating of claim 1, wherein the polyethylene furandicarboxylate is selected from PEF30 and/or a upto 90 of the institute Nibo Material of Zhongkojic.

4. The barrier coating of claim 1, wherein the dispersant is a polyacrylic acid ammonium or sodium salt based dispersant.

5. The barrier coating of claim 1, wherein the dispersant is Wolkel Germany

SILCO HLD-69 or BYK-190 of Pico chemistry.

6. The barrier coating of claim 1, wherein the defoamer is a polyether siloxane type defoamer.

7. The barrier coating of claim 1, wherein the anti-foaming agent is AIRASE-5355 or Foamaster WO 2360 by Pasteur.

8. The barrier coating of claim 1, wherein the wetting agent is a polyether siloxane.

9. The barrier coating of claim 1, wherein the wetting agent is BYK-346 or BYK-348 of BYK chemistry.

10. The barrier coating of claim 1, comprising the following composition: based on barrier coating weight

11. A method of making a barrier coating as claimed in any one of claims 1 to 10, comprising the steps of:

(1) Adding polyethylene glycol furandicarboxylate, hydrogenated polydecene and a dispersing agent into a dispersion tank, heating to 60-90 ℃, adding water for dispersing for 10-15min, and cooling to room temperature;

(2) And adding the acrylic emulsion into the blend under the condition of stirring, and sequentially adding a wetting agent and a defoaming agent to obtain the product.

12. A recyclable paper comprising the barrier coating of any one of claims 1 to 10.

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