JPS6312798A - Blended paper sheet and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mixed sheet mainly composed of crushed or cut plastic film and water-dispersible fibers, and a method for producing the same.

(Conventional technology) The ability to develop materials that are lightweight and have excellent heat insulation and sound absorption properties is in demand in the fields of construction materials, packaging materials, molding materials, etc., for the purpose of resource conservation, etc., and this has already been achieved. A wide variety of materials have been developed depending on the purpose and use.

Composite materials of plastic and natural bubbles or wood powder include the following.

■ A sheet made by extruding a mixture of plastic lumps or particles and wood fibers or powder at a temperature higher than the melting point of the plastic.

■ A sheet made by mixing synthetic pulp (hereinafter referred to as SWP) made from polyethylene/polypropylene or polystyrene with natural pulp.

■ A notebook made from a mixture of synthetic fibers such as vinylon and polyester and natural pulp.

(Problems to be Solved by the Invention) Sheets made by kneading and extruding plastic lumps or particles mentioned above and wood fibers and powders have difficulty uniformly dispersing the fibers and powders, resulting in uneven strength of the sheets. It has the disadvantage of being easy. Moreover, the density is 1. It is extremely difficult to obtain a sheet below Ov/-. or.

Since the sheets of (1) and (2) above use synthetic pulp and synthetic fibers, the product cost is inevitably high.

The present invention aims to provide a new mixed paper sheet in contrast to the conventional composite materials as described above.

(Means for Solving the Problems) The present inventors have developed a plastic film into thin (flake) material that can be easily mixed and dispersed uniformly with water-dispersible m-fibers and can be made into paper with low density. It was discovered that a material cut into shapes is suitable, and the present invention was completed.

That is, the mixed sheet according to the present invention has a thickness of 5 to 250 μm.
7-layer plastic with a surface area of 50 to 5000 i/P obtained by crushing or cutting a plastic film 1
10 to 200 parts by weight of water-dispersible fibers are added to 0.00 parts by weight, and the density is 0.05 to 0.9? /α is characterized by wet paper making.

Plastic films used in the present invention include polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, and polyester.

Polyamide, polycarbonate, polyvinyl acetate.

Examples include thermoplastic resin films such as polyethylene, polypropylene, and cellophane. Of course, thermosetting resin films may also be used.

Furthermore, waste plastic film sheets used as heat insulating materials for agriculture or gardening such as greenhouses, and laminated films from collected paper containers can be effectively reused.

In particular, a large amount of laminate film for paper containers is produced as a by-product in the process of separating and collecting pulp for reuse from collected paper containers, but according to the present invention, it is a by-product in large quantities.

Materials that used to be incinerated at great expense can now be reused in the same way as pulp.

Further, in the present invention, natural pulp produced from plant fibers such as wood, hemp, and mitsumata is used as the water-dispersible fiber.

Of course, it may be used paper. Furthermore, as long as it has good water dispersibility and does not cause problems in paper making, it may be used for the intended purpose (depending on the purpose, synthetic fibers such as vinylon, polyester, metal fibers, glass fibers, ceramic fibers, inorganic fibers such as rock wool, or synthetic pulp may be mixed into the paper). In particular, when mixed with inorganic fibers such as glass fibers and ceramic fibers, a very bulky sheet with good heat insulation and sound absorption properties and high strength, especially bending strength, can be obtained.Furthermore, a uniform sheet can be obtained. Polymer electrolytes such as polyacrylamide, CMC, gelatin,
It is possible to add starch, etc., and SBR can be used to solve papermaking problems.

Latexes such as NBR and acrylic, sizing agents, flocculants, etc. can also be added. Physical properties such as flexibility and flame retardance can be imparted by adding fillers such as talc, clay, aluminum hydroxide, and lucium carbonate.

Next, the manufacturing process of the mixed paper sheet of the present invention will be described.

First, the film is cut into pieces into flakes using a grinder such as a cutter mill. The size of the flake is surface area 50
~5000ca/f. If it is less than 50 tni/f, it lacks striped water dispersibility and tends to cause piping problems.

After that, predetermined water-dispersible fibers are mixed and the mixture is mixed and beaten in order to adjust freeness to obtain a good water-dispersed slurry. Furthermore, when a slurry in which plastic films are dispersed in water is refined using a paper refiner, the films become more intertwined with each other and with fibers, resulting in a sheet with high strength.

This slurry is made into paper using a paper machine and dried.

What you need to be careful about is the temperature during drying, and if the temperature is higher than the melting point of the film, you should not use a dryer.

Since there is a risk of contaminating paper machines such as canvases, drying is preferably performed at a temperature about 5 to 10°C lower than the melting point. By doing this, the paper machine is not contaminated, and the softened film acts as a binder, resulting in a high-strength sheet.

The sheet thus obtained has a density of 0.05 to 0.9?
/ 6n'' soft and lightweight sheet with excellent water resistance, dimensional stability, sound absorption, heat insulation, and cooking properties, so it can be used as is as a soundproofing material or cushioning material.

Furthermore, if this sheet is hot-pressed under conditions higher than the melting point of the film, the density can be increased, so various types of sheets can be obtained by selecting various heating and pressing conditions. In particular, when a rigid hard board is desired, a thermosetting resin such as a phenol resin or a melamine resin may be added in the slurry preparation step.

(Example) The present invention will be explained below using examples.

In the description, parts indicate parts by weight.

[Examples 1 to 4] A 30 μm thick polyethylene film was pulverized with a cutter mill to have a surface area of 2000 i/V to obtain a flaky film. To 100 parts of this flaky film, 20 parts of softwood unbleached sulfuric acid pulp (NUKP) with a Canadian standard freeness of 450- is added, and 2 parts of a sulfuric acid pad are added to make paper with a pH of about 4.5 and a concentration of 2%. A feed slurry was prepared.

This paper stock slurry is made into paper using a multi-j5 paper machine (Making roll) and dried at a dryer temperature of 90 to 95°C to give a basis weight of 1100 f/d and a density of 0.25? /et
A lightweight sheet with a thickness of 4.4 m was obtained. This sheet was bulky and thus suitable as a packing material.

Further, by heat pressing this lightweight sheet under one condition, sheets having different physical properties as shown in Examples 2 to 4 in Table 1 were obtained. These sheets could be used as interior materials for automobiles.

(Margin below) Table 1 Note 1: Quality evaluation is based on the following method.

Basis weight - JIS P8124 Thickness, density - JIS P8118 Stiffness - JIS P8125 Tensile strength - JIS P8113 Water absorption rate - JIS K6911 [Examples 5 to 8] Soft weirized vinyl film with a thickness of IOQμr
It was ground in a mill to a surface area of about 30 Q crd/f to obtain a flaky film. To 100 parts of this flaky film, 120 parts of kraft waste paper pulp with a Canadian standard freeness of 320-, 20 parts of G talc, and 2 parts of sulfuric acid were added to give a pH of about 4.5 and a concentration of 2.
．． A stock slurry of 5 cm was obtained.

This paper stock slurry is mixed in multiple layers (making roll).
The paper is made using a paper machine, dried at 80 to 90 degrees Celsius in a dryer, and then passed through a VCl heated roll at 50 to 160 degrees Celsius to produce a paper with a basis weight of 150 (1/y#, density 0.52?/α3, thickness 2 A lightweight sheet of .9 m was obtained.

This sheet has excellent water resistance and abrasion resistance, so it was suitable for the inner sole of shoes.

By hot pressing this lightweight sheet under various conditions, sheets with physical properties shown in Table 2 were obtained.

(Margin below) Table 2 [Example 9] A 20 μm thick polyethylene film laminated on a milk paper container was peeled off and cut into 18
The powder was crushed to a surface area of 00 i/f to obtain a flaky film. However, this flaky film contains about 10 centimeters of pulp. To 100 parts of the flaky film containing this pulp, 100 parts of used newspaper pulp was added, and 2 parts of sulfuric acid was further added to adjust the pH to approximately 4.5, resulting in a paper stock slurry with a concentration of 2.5 yen. I got it.

This paper stock slurry is made into paper using a Fourdrinier multi-tube paper machine.

Drying was performed using a dryer at a temperature of 90 to 100°C. The physical properties of the obtained sheet were as follows: basis weight: 50 (1/-1 thickness: 2.5 cm, density: 0
．． 20 f/cyt”, tensile strength 2.1/1.8
(Kf/J), and was suitable as a Kutsushi J/wood.

[Example 10] A polyethylene film with a thickness of 30 μm was pulverized with a cutter mill to a surface area of about 1000 m/V, and further processed with a double disc refiner to obtain a Canadian standard water rating of 550 m (surface area 5 OOOCFI/r). A flaky film was obtained. This flaky film 1
00 parts, 50 parts of softwood sulfate pulp (NBKF) with a Canadian standard freeness of 450- is added, and an additional 1c fiber diameter is 9.
After adding 5 parts of glass fiber having a fiber length of 3 μm and a fiber length of 3 strands with stirring, 2 parts of sulfuric acid was added to prepare a stock slurry having a pH of about 4.5 and a concentration of 2 strands.

This paper stock slurry is mixed in multiple layers (making roll).
The paper is made using a paper machine and dried at a dryer temperature of 90 to 95°C to a basis weight of 1000 f/i, a density of 0.30 f/m, and a thickness of 3.
I got a lightweight sheet of 3 gourds. This sheet is bulky and
Immediately after being softened in a hot atmosphere of 200°C, various drawing forms can be performed, making it suitable as a molding material.

[Example 11] A polypropylene film with a thickness of 30 μm was pulverized with a cutter mill to have a surface area of 1200 cm and 117 f.
A flaky film was obtained. To 100 parts of this flaky film, 20 parts of softwood sulfuric acid pulp (NBr(P)) with a Canadian standard freeness of 450- is added, and 150 parts of glass fibers with a fiber diameter of 18 μm and a fiber length of 61.m are further stirred. After adding 2 parts of sulfuric acid, the pH was adjusted to about 4.
5. A paper stock slurry with a density of 2 ml was prepared.

This paper stock slurry is mixed in multiple layers (making roll).
The paper is made using a paper machine and dried at a dryer temperature of 100 to 105°C to a basis weight of 600 t/r? , density 0.10? /α3
A very light sheet with a thickness of 6.0 m was obtained.

This sheet is bulky and rigid, and has a thermal conductivity of 0.028.
It has a small h kcal/ml of 1:: and is suitable as a heat insulating material for building materials. It was also suitable as a molding material for automobiles.

[Example 12] A polyester film having a thickness of 40 μm was ground in a turbo mill to a surface area of about 800 ccm 2 /g to obtain a flaky film. For 100 parts of this flaky film, Canada 15'4Q freeness 350
-10 parts of NBKF, fiber diameter 13 pm.

20 parts of glass fiber with a fiber length of 61 al was added, and further 2 parts of sulfate was added to adjust the pH to about 4.5. A stock slurry with a J degree of 2.5 degrees was obtained.

This paper stock slurry is placed in multiple layers (making roll).
The paper is made using a paper machine, dried at 80 to 90°C with a dryer, and then passed through hot rolls at 130 to 140°C to give a basis weight of 1000 t/-" and a density of 0.78?/cm.
A lightweight sheet with a thickness of 1.3 mm was obtained.

This sheet has excellent dimensional stability, water resistance, heat resistance, abrasion resistance, and high strength, so it was suitable as a molding base material for automatic interiors.

[Example 13] A 25 μm thick polyethylene film laminated on a milk paper container was peeled off and cut into approximately 1
The powder was crushed to a surface texture of 500 c1/i/'f to obtain a flaky film. However, this flaky film contains about 10 times 11 inches of pulp. Flake-like film 10 with this pulp mixed in
To 0 parts, add 50 parts of NUKP, further add 50 parts of G Kurji, and then add 2 parts of sulfuric acid to adjust the pH to about 4.
．． 5 to obtain a stock slurry with a density of 2.5.

This paper stock slurry is placed in multiple layers (making roll).
The paper is made using a paper machine and dried at a dryer temperature of 90 to 95°C to produce a paper with a basis weight of 8009/rr? , density 0125fl 7cm3
A lightweight sheet with a thickness of 3.2 mm was obtained. This sheet was bulky and flexible, making it suitable for use as cushioning material for packaging.

Sheets with different physical properties were obtained. These sheets could be used as shoe insole sheets and bag base materials.
Table 3 The quality evaluation is based on the following method.

Tsuboit - JIS P8124 Thickness, Density - J
IS P8118 Stiffness - JIS P8125 (Effects of the Invention) Since the mixed sheet of the present invention is made of a plastic film cut into fine flakes, a bulky snack sheet can be obtained, and it can be Since the mixture and dispersion with water-dispersible fibers is uniform, the strength of the sheet is even.

Furthermore, this sheet itself can be used as a cushioning material, soundproofing material, etc., but if it is heated and pressurized under various conditions, it can be used as a substitute for various conventional boards such as automobile interior materials and shoe insole materials. .

On the other hand, the plastic film used as the material can be made from film sheet waste from plastic greenhouses, laminated film from collected paper containers, etc., so the present invention is effective in terms of effective use of resources. big.

Claims (7)

[Claims] (1) Surface area of 50 to 5000 cm^2 obtained by crushing or cutting a plastic film with a thickness of 5 to 250 μm
10 to 200 parts by weight of water-dispersible fibers are added to 100 parts by weight of plastic flakes with a density of 0.05
A mixed sheet made by wet papermaking to ~0.9g/cm^3. (2) The mixed sheet according to claim 1, wherein the plastic film is a laminating polyethylene film peeled from a paper container. (3) The mixed sheet according to claim 1, wherein the water-dispersible fiber is at least one kind of inorganic fiber selected from glass fiber, rock wool, ceramic fiber, and metal fiber. (4) The mixed paper sheet according to claim 1, wherein the water-dispersible fiber is natural pulp. (5) The mixed sheet according to claim 1, wherein the water-dispersible fibers are a mixture of inorganic fibers and natural pulp. (6) A plastic film with a thickness of 5 to 250 μm is made into a water-dispersed slurry with a concentration of 10% or less, crushed or cut into flakes with a surface area of 50 to 5,000 cm^2/g using a paper refiner, and then the flaked plastic is A method for producing a mixed paper sheet, which comprises adding 10 to 200 parts by weight of water-dispersible fiber to 100 parts by weight. (7) Surface area of 50 to 5000 cm^2 obtained by crushing or cutting a plastic film with a thickness of 5 to 250 μm
A mixed paper sheet obtained by adding 10 to 200 parts by weight of water-dispersible fibers to 100 parts by weight of flaky plastic of 100 parts by weight and carrying out wet paper making, followed by heating and pressing.