JP3353274B2 - Moisture- and water-resistant rust-proof paper that can be reused - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rust-proof paper, and more particularly to a moisture- and water-proof rust-proof paper which can be used as a raw material for recycled paper.

[0002]

2. Description of the Related Art In general, a rust preventive sheet obtained by applying or impregnating a sheet with a vaporizable rust preventive agent in which vaporized steam exerts a rust preventive effect on a metal is well known. It is widely used for transportation.

[0003] However, the rust-preventive sheet using kraft paper or the like as the sheet has a water permeable or moisture-absorbing property. Therefore, metals wrapped in the rust-preventive sheet are placed under high temperature and high humidity. When the rust prevention sheet enclosing the metal is wet with water, the metal has a disadvantage that the metal gets wet and extremely easily rusts.

On the other hand, a rust-preventive sheet obtained by applying or impregnating a rust-preventive agent to the paper surface of a laminated paper obtained by laminating a kraft paper with a polyolefin-based film such as polyethylene or polypropylene has a laminate film that is smaller than paper. Because it has the property of being extremely hard to penetrate water, even when the metal wrapped with the rust-proof sheet is placed under high temperature and high humidity, or when the rust-proof sheet wrapped with the metal is wet with water In addition, metal is hard to get wet and exhibits an excellent rust prevention effect.

However, the laminated rust-preventive sheet having such advantages has a problem that it cannot be used as a raw material for recycled paper because of the use of a film, and is preferable from the viewpoint of resource saving. It can not be said.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a moisture- and water-resistant rust-proof paper which can be used as a raw material for recycled paper.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method for preparing a paper comprising an acrylate resin as a main component and substantially a wax
The dry weight of the aqueous coating layer containing no component is 3 to 50 g / m.
Moisture- and water-resistant rust-proof paper that can be used and reused, characterized in that the paper is provided in ^two ranges, the moisture permeability of the paper is 200 g / m ² · 24 h or less, and a vaporizable rust preventive composition layer is provided on the back surface. It is.

[0008]

The resin used in the present invention is, for example, an acrylate (co) polymer, which may be used alone or in combination as an emulsion or colloidal dispersion . A acrylic acid esters that have good barrier properties.

[0009] In addition to the above resins, the coating liquid for forming the aqueous coating layer may optionally contain silica, calcium carbonate, aluminum hydroxide, zinc oxide, titanium oxide, kaolin, melamine resin particles, benzogamine resin particles, urea resin particles, pigment and phenol resin particles; metallic soaps, silicones, release agents fluorine compounds and the like; surfactants, antioxidants, ultraviolet absorbers, antistatic agents, antifoaming agents, thickeners Various auxiliary agents such as a dispersant and a colorant may be added. Such an auxiliary is usually added so as to be 50% by weight or less based on the solid content of the coating liquid.

[0010] The coating liquid is prepared as an aqueous system, and is usually prepared using a coating machine such as a bar coater, a roll coater, a gravure coater, an air knife coater, a blade coater or the like to obtain bleached kraft paper having a size or no size.
Dry weight on unbleached kraft paper, high-quality paper, etc. 3-50g
/ M ² .

[0011] Incidentally, if it is less than 3 g / m ^2, it is difficult to reach the desired level of moisture and water resistance, and if it exceeds 50 g / m ² , there is a problem in terms of economy. Coating amount is 3-50 dry weight
g / m ² range, among them a range of 3 to 50 g / m ² is particularly preferred.

[0012] As quality characteristics of resin coated paper,
Water repellency based on P 8137 is R₈~ R _TenAnd JIS Z 0208
2000g / m^Two.Less than 24h
Is preferable, and particularly, the water repellency is R_TenAnd the moisture permeability is 200g /
m^Two-The thing of 24h or less is preferable.

Examples of the rust preventive used in the present invention include dicyclohexylammonium nitrite, dicyclohexylammonium caprylate, dicyclohexylammonium carbonate, diisopropylammonium nitrite, monoethanolammonium benzoate, sodium benzoate, benzoic acid, caprylic acid, and the like. Capric acid, isopropyl benzoate, butyl benzoate, butyl cinnamate, ammonium carbamate, monoethylamine, diethylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, methylmorpholine, ethylmorpholine, hexamethylenetetramine, benzotriazole, tolyl Materials known in the art such as triazole, urea, thiourea, sodium nitrite, and the like.

The vaporizable rust inhibitor composition used for coating is as follows:
It is prepared by dispersing, dissolving, or mixing one or more of the above rust preventives in water, and further adding a binder, a penetrant such as alcohol, and the like, if necessary.

The application of the vaporizable rust inhibitor composition is usually performed on the back side of the resin-coated surface using a coating machine such as a bar coater, a roll coater, a gravure coater, or an air knife coater. The coating liquid is usually applied so that the dry weight is ² to 50 g / m ² . By the way, when it is below 2 g / m ² , the rust prevention effect is weak, and when it is above 50 g / m ² , the production cost becomes extremely high.

[0016]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto. Unless otherwise specified, parts and% in the examples are parts by weight and% by weight, respectively.

Example 1 One side of 80 g / m ² neutral no-size unbleached kraft paper
Aqueous coating liquid of 40% acrylic ester emulsion (trade name: Sibinol X-590-376E-5, manufactured by Siden Chemical Co.) was coated with a bar coater at a coating amount of 15 g / m.
² was coated so that the dry weight, water repellency and dried under 115 ° C. moisture permeability with R ₁₀ to obtain a resin coated paper 200g / m ² · 24h.

Subsequently, sodium nitrite 20 was added to 60 parts by weight of water.
Parts by weight and 20 parts by weight of monoethanolammonium benzoate were dissolved and coated with a rust-preventive coating liquid on a back surface of the resin-coated paper using a bar coater so that the coating amount was 15 g / m ² dry weight). And dried at 115 ° C. to produce rust-proof paper. The obtained rust-proofing paper showed good rust-preventing ability against iron under high temperature and high humidity, and was defibrated to be used as a raw material for recycled paper.

COMPARATIVE EXAMPLE 1 Instead of 40% acrylic ester emulsion aqueous coating liquid. A rust-proof paper was obtained in the same manner as in Example 1 except that a 40% ethylene vinyl acetate emulsion aqueous coating solution was used. The resulting rust-proof paper was slightly inferior to the rust-proof paper of Example 1, but exhibited an effective rust-preventive ability, and was defibrated to be used as a raw material for recycled paper.

[0020]

Comparative Example 2 Rust prevention was carried out in the same manner as in Example 1 except that a resin-coated paper obtained by coating an aqueous coating solution of an acrylic ester emulsion so as to have a coating amount of 2 g / m ² ( dry weight) was used. I got the paper. The obtained rust-proofing paper could be defibrated and used as a raw material for recycled paper, but had a very poor rust-proofing ability against iron under high temperature and high humidity.

Comparative Example 3 Rust-proof paper was prepared in the same manner as in Example 1 except that a polyethylene-laminated sheet was used on one side of 80 g / m ² neutral no-size unbleached kraft paper instead of resin-coated paper. Obtained. The resulting rust-proof paper showed good rust-proofing properties against iron under high temperature and high humidity, but could not be disaggregated and could not be used as a raw material for recycled paper.

[0023]

The rust-proofing paper of the present invention has good rust-preventing ability against iron under high temperature and high humidity, and can be used as a raw material for recycled paper after defibration.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shunsuke Shioi 4-3-1 Jokoji, Amagasaki-shi, Hyogo Kanzaki Paper Co., Ltd. Kanzaki Mill (56) References JP-A-63-5943 (JP, A) 59-160227 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) D21H 11/00-27/42

Claims (1)

(57) [Claims] 1. An aqueous coating layer containing an acrylate resin as a main component and containing substantially no wax component in a dry weight range of 3 to 50 g / m ² is provided on the surface of paper to reduce the moisture permeability of the paper. A moisture- and water-resistant rust-proof paper that can be recycled and reused, characterized in that it is 200 g / m ² · 24 h or less and a vaporizable rust-preventive composition layer is provided on the back surface.