Impregnated cellulosic fiber substrate material

Abstract

The present invention relates to a cellulosic fiber-based sheet comprising a layer comprising untreated pulp and an impregnated cationized vegetable wax. The invention also relates to: an insulating material comprising a foam and a cellulosic fiber-based sheet, the layer comprising untreated pulp of which has a grammage of at least 50 g / m2; a food packaging material comprising a cellulosic fiber-based sheet having a layer comprising untreated pulp having a gram weight of 30 to 90 g / m2; and a corrugated packaging material comprising an inner liner and an outer liner, the inner liner and the outer liner comprising a cellulosic fiber base sheet material.

Description

Technical Field

[0001] This disclosure relates to a cellulose fiber-based sheet comprising a layer of untreated pulp and an impregnated plant wax, suitable for use as a building material and packaging material. Background Technology

[0002] Building and packaging materials typically need to be hydrophobic and have a water vapor barrier. Conventionally, these materials can be laminated with or comprise aluminum foil layers or polymer layers (e.g., PE). Another conventional solution is impregnation with siloxane materials. These solutions are neither environmentally friendly nor sustainable.

[0003] Therefore, there is a need to develop and provide an environmentally friendly and sustainable material that can impart hydrophobic and water vapor barrier properties to building materials, packaging materials and related materials, and that can be produced on an industrial scale.

[0004] The inventors unexpectedly discovered that bulky sheets containing cellulose fibers can be treated with cationic plant waxes to modify the sheets and create a hydrophobic surface. The inventors did not anticipate that the cationic plant waxes could adhere to and seal the fluffy fibrous surface of the sheet, thus allowing the observation of the so-called lotus leaf effect.

[0005] Based on the inventor's research, one object of this disclosure is a cellulose fiber-based sheet comprising: - Contains a layer of untreated pulp, and - Impregnated cationic plant wax.

[0006] Since cellulose fiber-based sheets are suitable for use in building materials, another objective is to provide an insulating material comprising: -Foam, and - The aforementioned cellulose fiber-based sheet, comprising a layer of untreated pulp, has a content of at least 50 g / m² as measured by ISO 536:2019. 2 The weight in grams.

[0007] When used in combination with foams intended for sound insulation, the cellulose fiber-based sheet of this invention provides a sustainable, environmentally friendly water barrier layer for the foam. The basis weight of the untreated pulp therein is 100 g / m³. 2 In more advanced cases, the inventors have observed that the cellulose fiber sheets of the present invention contribute to the sound insulation of insulating materials containing foam.

[0008] Since cellulose fiber-based sheets are suitable for packaging materials, another objective is to develop food packaging materials comprising the aforementioned cellulose fiber-based sheets, wherein the layer of untreated pulp has a content of 30 to 90 g / m³ as measured by ISO 536:2019.2 The weight in grams.

[0009] Another objective is a corrugated packaging material comprising an inner liner and an outer liner, the inner and outer liner comprising the aforementioned cellulose fiber-based sheet.

[0010] When used in packaging materials, the cellulose fiber-based sheet of the present invention provides a sustainable, environmentally friendly water barrier layer and replaces conventional aluminum or polymer foil or silicone-based impregnation. Detailed Implementation

[0011] This disclosure provides a cellulose fiber-based sheet material comprising: - A layer containing untreated pulp, and - Impregnated cationic plant wax.

[0012] The layer containing untreated pulp is a layer containing pulp that has been chemically treated to remove lignin. In other words, this layer contains chemically treated pulp. The pulp in this layer has not undergone any further treatment prior to the application of the cationic plant wax coating.

[0013] The layer containing untreated pulp can have a strength of 30 to 200 g / m³ as measured by ISO 536:2019. 2 Preferred concentration: 50 to 150 g / m 2 The basis weight. In some implementations, the basis weight can be 30 to 90 g / m³. 2 In some implementations, the basis weight can be 90 to 200 g / m³. 2 Preferred concentration: 100 to 130 g / m 2 .

[0014] The layer containing untreated pulp may have a concentration of 5 to 30 g / m³ as determined by COBB 60 and measured according to ISO 535:2014-06. 2 Preferred concentration: 10 to 20 g / m 2 More preferably 14 to 18 g / m 2 Water absorption rate.

[0015] The layer containing untreated pulp has an air permeability of 100 to 500 l / m² as determined by EN ISO 9237:1995. 2 s, preferably 110 to 400 l / m 2 s, or 120 to 300 l / m 2 s, or 130 to 230 l / m 2 The porosity of s.

[0016] When measured under a pressure of 10 kPa according to ISO 534:2012, the layer containing untreated pulp may have a thickness of 0.1 to 0.8 mm, preferably 0.2 to 0.6 mm.

[0017] The layer may contain one or more pulps selected from wood, fiber crops, rag paper, or waste paper.

[0018] Impregnation of a layer refers to the application of a solution or suspension containing cationic plant wax. The wax penetrates the sheet and is present on the surface of the fibers, so that it is not only present on the surface of the sheet. Depending on the production process and its parameters, the layer containing untreated pulp can be completely impregnated with plant wax, or only partially impregnated from one or both sides with the wax.

[0019] According to ISO 536:2019, the cationic vegetable wax contained in the impregnation of the layer containing untreated pulp can be 5 to 20 g / m³. 2 Preferred concentration: 7 to 15 g / m 2 More preferably 8 to 12 g / m 2 .

[0020] The impregnated cationic plant wax may include waxes having a melting point of 50 to 90 degrees Celsius, preferably 60 to 80 degrees Celsius. These temperature ranges ensure that the plant wax has sufficient fluidity and viscosity to be applied to the cellulose fibers of the layer containing the untreated pulp during the production process and when applied to the layer containing the untreated pulp. At these temperatures, the wax impregnates the layer containing the untreated cellulose fibers, covers the cellulose fibers, and is also dried. The impregnated cationic plant wax may include cationic soybean wax, pea wax, rice bran wax, sugar bran wax, palm wax, or mixtures thereof, wherein the wax has been cationicized by procedures known in the field of fatty acid derivatization and modification. Preferably, cationic soybean wax sold by Euikas under the name EuikaCoat SW144 can be used.

[0021] Impregnated cationic plant waxes may include cationic solutions or emulsions of cationic soybean wax, pea wax, or rice wax or mixtures thereof, wherein cationicization is achieved by a standard cationic emulsifier.

[0022] The use of cationic plant wax enables the adhesion of the plant wax to the cellulose fibers in a layer containing untreated pulp. Due to the wax, the layer containing untreated pulp becomes hydrophobic, such that when water droplets are applied to the surface of the cellulose fiber-based sheet of this disclosure, a lotus leaf effect is still observed after 12 hours (overnight). Therefore, this disclosure provides a cellulose fiber-based sheet that is a sustainable and environmentally friendly water barrier layer.

[0023] The cellulose fiber-based sheet disclosed herein is applicable to various technical fields, such as sound insulation. If the cellulose fiber-based sheet comprises an untreated pulp layer with high basis weight and high porosity (measured by air permeability), the sheet disclosed herein can provide a degree of sound insulation and moisture resistance when applied to walls, roofs, ceilings, or floors. It can also be used in door panels or other components of vehicle chassis.

[0024] In this example, the insulating material comprises: -Foam, and - The aforementioned cellulose fiber-based sheet, comprising a layer of untreated pulp, has a content of at least 50 g / m² as measured by ISO 536:2019. 2 The weight in grams.

[0025] The weight can be 90 to 200 g / m³ 2 Preferred concentration: 100 to 130 g / m 2 .

[0026] According to EN ISO 9237:1995, the porosity (measured by air permeability) of insulating materials can be from 120 to 500 l / m. 2 ·s.

[0027] Foam can be a standard type of foam commonly used in building materials for sound insulation, particularly for footsteps. When the sheets of this disclosure are applied to foam, improved sound insulation performance of the composite product has been observed. Therefore, the sheets of this disclosure provide hydrophobicity and sound insulation at high basis weights, while also being sustainable and environmentally friendly.

[0028] The cellulose fiber-based sheets disclosed herein can also be used as packaging materials. Due to the water vapor barrier effect provided by the wax coating on the sheets, they are suitable for packaging moisture-sensitive devices or foods.

[0029] In the example, the food packaging material comprises the aforementioned cellulose fibers, including a layer of untreated pulp with a strength of 30 to 90 g / m³ as measured by ISO 536:2019. 2 The weight in grams.

[0030] The sheet disclosed herein replaces conventional aluminum foil, polymer sheets, or cellulose fiber-based sheets that have been laminated with polymer sheets to achieve a water barrier effect.

[0031] The sheet disclosed herein can also be used as part of a corrugated building material, wherein the sheet can be included as an inner or outer lining.

[0032] The cellulose fiber-based sheet disclosed herein can be produced by various methods known in the papermaking and processing industries.

[0033] As described above, it has a high basis weight (e.g., 90 to 200 g / m³). 2 Preferred concentration: 100 to 130 g / m 2 ) and high porosity (e.g., 120 to 500 l / m) 2 Cellulose fiber-based sheets (s) can be produced on a slanted wire paper machine, thereby forming a layer containing untreated pulp, which is then fed into a sizing machine to apply a plant wax coating and impregnate with plant wax as described above. The degree of impregnation of the cellulose fiber-based sheets with plant wax can be adjusted by the settings of the sizing machine. Thus, the sheets are impregnated from both sides.

[0034] As described above, cellulose fiber-based sheets with lower basis weights, i.e., thinner sheets, can be produced using a standard wet web forming process. The paper can then be impregnated or coated from one or both sides using a coater.

Claims

1. A cellulose fiber-based sheet comprising... - Contains a layer of untreated pulp, and - Impregnated cationic plant wax.

2. The cellulose fiber-based sheet of claim 1, wherein the layer comprising untreated pulp has a content of 30 to 200 g / m² as measured by ISO 536:2019. 2 Preferred concentration: 50 to 150 g / m 2 The weight in grams.

3. The cellulose fiber-based sheet as claimed in claim 1 or 2, wherein the layer comprising untreated pulp has an air permeability of 100 to 500 l / m² as determined by air permeability measurement according to EN ISO 9237:1995. 2 s, preferably 110 to 400 l / m 2 s, or 120 to 300 l / m 2 s, or 130 to 230 l / m 2 The porosity of s.

4. The cellulose fiber-based sheet according to any one of claims 1 to 3, wherein the layer comprising untreated pulp has a strength of 5 to 30 g / m² as determined by COBB 60 and measured according to ISO 535:2014-06. 2 Preferred concentration: 10 to 20 g / m 2 Water absorption rate.

5. The cellulose fiber-based sheet according to any one of claims 1 to 4, wherein the layer comprising untreated pulp has a thickness of 0.1 to 0.8 mm, preferably 0.2 to 0.6 mm, under 10 kPa conditions as measured according to ISO 534:2012.

6. The cellulose fiber-based sheet according to any one of claims 1 to 5, wherein the layer comprising untreated pulp comprises one or more pulps selected from wood, fiber crops, rag paper, or waste paper.

7. The cellulose fiber-based sheet according to any one of claims 1 to 6, wherein the cationic vegetable wax contained therein, as measured according to ISO 536:2019, is 5 to 20 g / m². 2 Preferred concentration: 7 to 15 g / m 2 .

8. The cellulose fiber-based sheet according to any one of claims 1 to 7, wherein the impregnated cationic plant wax comprises a wax having a melting point of 50 to 90 degrees Celsius, preferably 60 to 80 degrees Celsius.

9. The cellulose fiber-based sheet according to any one of claims 1 to 8, wherein the impregnated cationic plant wax comprises cationic soybean wax, pea wax or rice wax, or a mixture thereof.

10. The cellulose fiber-based sheet according to any one of claims 1 to 9, wherein the impregnated cationic plant wax comprises a cationic solution or emulsion of cationic soybean wax, pea wax or rice wax or a mixture thereof.

11. An insulating material comprising: -Foam, and - A cellulose fiber-based sheet as claimed in any one of claims 1 to 10, wherein the layer comprising untreated pulp has a content of at least 50 g / m² as measured by ISO 536:2019. 2 The weight in grams.

12. A food packaging material comprising a cellulose fiber-based sheet as claimed in any one of claims 1 to 10, wherein the layer comprising untreated pulp has a content of 30 to 90 g / m² as measured by ISO 536:2019. 2 The weight in grams.

13. A corrugated packaging material comprising an inner liner and an outer liner, said inner liner and outer liner comprising a cellulose fiber-based sheet according to any one of claims 1 to 10.