JPH09156062A - Packaging paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve printability and bag manufacturing processability by a method wherein the first paper base material with a basis wt., a wet tensile strength and a surface strength each in a specified range is used as the outer surface and it is laminated with a synthetic fiber sheet and the second paper base material for the inner surface to form a packaging paper. SOLUTION: A packaging paper has a structure prepd. by laminating the first paper base material, a synthetic fiber sheet and the second paper base material. In addition, the first paper base material is for the outer surface and as water resistance and printability are required, it has a basis wt. of 40-100g/m<2> , a wet tensile strength of at least 0.7kgf/15mm and a surface strength of at least 10A. On the other hand, as the second paper base material becomes the wrapped article side when it is made into a bag, it is provided for improving bag manufacturing processability to exhibit such functions as preventing curls from occurring, easiness of applying a paste and decreasing slippage when it is laminated. It is possible thereby to keep good water resistance and to exhibit excellent bag manufacturing processability and good printability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of packaging paper which can be suitably used for mailing envelopes, parcel packaging bags, courier packaging bags, etc. The present invention relates to a packaging paper having properties.

[0002]

2. Description of the Related Art In the past, when sending documents, articles, etc. by mail, parcel, courier, etc., water-proof packaging bags have been used to prevent damage from water leakage. Water-resistant wrapping paper forming this type of envelope / packaging bag is a so-called laminated paper in which a water-resistant polymer material is laminated on paper,
BACKGROUND ART Synthetic paper (nonwoven fabric) in which a fiber made of a water-resistant polymer material is formed into a sheet is used. However, when laminated paper is used, there are problems that curling occurs, bagging processing characteristics such as difficulty in gluing and bending are poor, and wet strength of paper is insufficient. When synthetic paper is used, when the desired printing of the address, company name, etc. is performed on the surface of the wrapping paper, special ink is required due to poor ink acceptance, and precise printing is difficult, etc. However, there is a problem of paper feeding in the printing process due to the problem of printability and the tendency of slipping when the sheets are stacked. Further, since the surface of the synthetic paper is slippery and the glue at the time of sealing is limited, there is a problem in the workability of bag making.

[0003]

In view of the above-mentioned circumstances, the present invention is an envelope or packaging bag suitable for use in mail, courier service, etc., which has excellent printability and bag-making processing characteristics without impairing good water resistance. The present invention provides a wrapping paper.

[0004]

According to the present invention, a first paper base material, a synthetic fiber sheet, and a second paper base material are sequentially laminated, and the first paper base material is for an outer surface. And, and
Basis weight 40 to 100 g / m ² , wet tensile strength 0.7 kg
A wrapping sheet having a f / 15 mm or more and a surface strength of 10 A or more. The first paper base material in the present invention is an outer surface when it is made into a bag in an envelope or the like or when it is packaged as a sheet-shaped wrapping paper, that is, it is an outer side with respect to the article to be encapsulated. The quality and printability are required. In order to satisfy such characteristics, the first
As a paper base material, the wet tensile strength is 0.7 kgf / 1
5 mm or more, preferably 1.0 kgf / 15 mm or more, and surface strength of 10 A or more, preferably 14 A
The basis weight is 40 to 100 g / m ² , preferably 50
Paper to 80 g / m ² is used. If the basis weight deviates from this range, the bag-making process properties will be impaired as described later, and the wet tensile strength will be 0.7 kgf / 15 m.
If it is less than m, good water resistance cannot be obtained and the surface strength is 10A.
If it is less than the above range, problems such as paper scraping and paper dust generation during printing occur, and good printing characteristics cannot be obtained. In addition,
In order to achieve more excellent water resistance, printability, writability, etc., the first paper base material preferably has a size degree of 10 seconds or more and a smoothness of 60 seconds or more. It is preferable that the opacity is 75% or more.

[0005] On the other hand, the second paper base material is an inner side when the bag is made in an envelope or the like, that is, the side of the article to be included, and is provided for improving the bag making process characteristics. Second
The paper base material has functions such as curling prevention, ease of gluing, and reduction of slippage when laminated. Such a paper substrate has a basis weight of 30 to 100 g / m ² , and particularly 3
Paper having a weight of 5 to 60 g / m ² is preferable in view of the above-mentioned bag-making processing characteristics, and particularly, paper having the same basis weight as the first paper base material or a difference between them is 25 g / m ² or less is suitable. . Furthermore, in order to obtain more excellent bag-making processing characteristics, the first paper base material has the same or similar properties as those of the pulp composition, the beating degree, the additives such as fillers and sizing agents, the compositions such as thickness and density, and the like. Paper is especially suitable.

The first paper base material and the second paper base material in the present invention have the above-mentioned characteristics, and the composition thereof is not particularly limited, and for example, paper produced by a wet papermaking method. Is used as appropriate. Specifically, coniferous wood as a pulp material, wood pulp such as kraft pulp prepared solely or appropriately by blending hardwood, sulfite pulp, semi-chemical pulp, and bleached pulp are preferable to obtain clear printing . In addition, waste paper pulp and non-wood pulp such as bagasse, kenaf, cotton, hemp, esparto, bamboo and straw can also be used.

Further, the first and second paper bases are mixed with a pulp raw material such as a sizing agent, a wet paper strength agent, and a filler as additive chemicals, or a surface paper strength enhancement as a coating chemical after papermaking. The above-mentioned characteristics such as wet tensile strength can be obtained by appropriately applying the agent. The sizing agent contributes to the improvement of water resistance and writability. For example, rosin type (solution type, emuljoun type), alkyl ketene dimer, alkenyl succinic anhydride, wax type, styrene type resin, olefin type resin, styrene acrylic. Examples of the resin include resins and styrene-maleic acid resins. The wet paper strength agent is used to give the first paper base material a wet tensile strength of 0.7 kgf / 15 mm or more, and examples thereof include a melamine resin, a polyamide epichlorohydrin resin, and a urea resin. However, the present invention is not limited to these.
Further, the filler improves smoothness and opacity and contributes to printability, writability, and hiding property, and for example, kaolin, clay, talc, titanium dioxide, calcium carbonate and the like are used.

The surface paper strength enhancer is intended to improve the printability by improving the surface strength of the paper base material. For example, oxidized starch, esterified starch, polyacrylamide, acrylic resin, polyvinyl alcohol, SBR, NBR. A vinyl oxide resin or the like can be used by coating with a size press of a paper machine or an off-machine coater. In addition, as an additive agent for internal addition to pulp raw materials, starch, modified starch, carboxymethyl cellulose, polyacrylamide, styrene resin and other internal paper strength agents, colorants, sulfuric acid bands, polyacrylamide and other fixing agents, and coating In addition to the above-mentioned surface strength enhancer, water resistant agents such as dialdehyde starch, melamine resins, polyamide resins, antistatic agents, water repellents, antifriction agents, surface sizing agents and pigments are used as necessary as chemicals. can do.

In the present invention, in order to impart good water resistance and printability to the first paper base material, 0.01 to 1.0 parts by weight of a wet paper strength agent is added to 100 parts by weight of pulp. It is preferable to use the sizing agent in an amount of 0.2 to 1.0 part by weight and to apply the surface paper strength enhancer in an amount of 0.5 to 2.5 g / m ² . Also, the second paper base should be as primary as possible as described above.
It is preferable to have a composition similar to that of the paper base material from the viewpoint of bag-making processing characteristics, but since wet strength is not required, it is not necessary to add a wet paper strength agent. When the hiding property is required, the amount of the filler added to obtain the desired opacity is larger in the second paper base material, specifically, in pulp 100.
It is preferable that the first paper base material is 5 to 30 parts by weight and the second paper base material is 10 to 40 parts by weight with respect to parts by weight so that the opacity is 75% or more. This is because if the added amount is small, it becomes difficult to obtain good opacity, and conversely, if the added amount is too large, the strength of the paper may be impaired.

As the synthetic fiber sheet in the present invention,
Nonwoven fabrics or synthetic papers made of synthetic fibers such as polyolefins, polyamides, acrylics and polyesters are used. Such a sheet imparts strength to the packaging paper of the present invention, and is preferably made of synthetic fiber having excellent water resistance, and a sheet formed by heat-sealing fibers is particularly preferable. Among them, a polyolefin-based synthetic fiber having good water resistance and large fiber strength is preferable in the present invention,
In particular, a mesh-like non-woven fabric obtained by arranging split fibers of polyethylene or polypropylene so as to cross each other in the longitudinal direction and the transverse direction and fusing them is specifically preferable. Specifically, the product name is Nisseki Warif (manufactured by Nisseki Plasto). Is mentioned. The synthetic fiber sheet as described above preferably has a basis weight of 10 to 50 g / m ² , and particularly preferably 15 to 30 g / m ² . If the basis weight is less than 10 g / m ^2, it is difficult to obtain sufficient strength. On the contrary, if the basis weight exceeds 50 g / m ² , there is a possibility that bag-making processing characteristics, particularly bending property, may deteriorate.

The wrapping paper of the present invention has a constitution in which the above-mentioned first paper base material, synthetic fiber sheet and second paper base material are laminated to form a basis weight of 80 to 200 g /
It is preferable that the sheets are laminated so that the weight becomes m ^2, and particularly when used as an envelope for mailing, the bag needs to be lightweight so as not to cause a problem that the bag is heavy and shipping cost is increased in order to increase strength. In order to obtain sufficient strength, it is preferable that the basis weight is 100 to 140 g / m ² together with the above structure. If the basis weight is less than 80 g / m ² , the strength required for the packaging bag may be impaired,
If the grammage exceeds 200 g / m ² , there is a possibility that a bag-making process becomes difficult to perform. Therefore, in the present invention, the basis weight of the waterproof packaging paper as a laminate is 20
It is necessary to use 0 g / m ² or less and use the first paper base material and the second paper base material whose basis weights are as close as possible to each other in order to prevent transportability in a bag making machine and troubles during processing. Therefore, it is desirable that the basis weight of such a paper substrate is 100 g / m ² or less.

The method for producing the packaging paper of the present invention as described above is not particularly limited, and for example, lamination using an adhesive, lamination by heat fusion and the like are used. When a material having a relatively low melting point is used as the synthetic fiber sheet, it can be easily manufactured by stacking the first paper base material, the synthetic fiber sheet, and the second paper base material and thermocompression bonding. Therefore, the heat fusion method is preferable. In addition, the measuring method of each characteristic value in this invention is as follows. (A) Basis weight JISP8124 (b) Wet tensile strength JISP8135 (c) Surface strength JISP8129 (d) Size degree JISP8122 (e) Smoothness JISP8119 (f) Opacity JISP8138 Further, the packaging paper of the present invention is for bag making. Besides, it can also be used for the purpose of wrapping articles in a sheet form.

[0013]

Next, the present invention will be described with reference to examples. Example 1 A pulp raw material comprising 30% by weight of NBKP and 70% by weight of LBKP was prepared with a beating machine to a beating degree of 50 ° SR, and a raw material obtained by adding an internal chemical to pulp in the following composition was prepared by a Fourdrinier paper machine. After papermaking, apply a 4 wt% solution of oxidized starch (SK-20, manufactured by Nippon Constarch Co., Ltd.).
After drying (coating amount: 1.2 g / m ² ), a first paper base material was prepared. The smoothness was adjusted with a machine calendar. (Internal additive) Rosin sizing agent (Arakawa Chemical Co., Ltd., Size Pine E) 0.8% by weight Sulfate band (Nippon Light Metal Co., Ltd.) 3.0% by weight Melamine resin (Sumitomo Chemical Co., Ltd., Sumireze Resin 607SY) 0 0.03% by weight Clay 10% by weight

Further, as the second paper base material, the melamine resin is not used as the internal additive in the first paper base material, and the amount of clay is 30% by weight. Similarly, a second paper base material was produced. Next, the above-mentioned first paper base material, polyethylene non-woven fabric (manufactured by Nisseki Plast Co.,
The Nisseki Warif SS, the basis weight of 18 g / m ² ) and the second paper base material were sequentially laminated and heat-pressed at a temperature of 180 ° C. to obtain a packaging paper of the present invention.

Example 2 The present invention was carried out in the same manner as in Example 1 except that the blending amount of the melamine resin as an internal additive was changed to 0.05% by weight in the first paper base material of Example 1. I got the wrapping paper. Example 3 In the first paper substrate and the second paper substrate of Example 1,
The same procedure as in Example 1 was repeated except that the rosin sizing agent as an internal additive was replaced by an emulsion sizing agent (SPN-771 manufactured by Arakawa Chemical Co., Ltd.) and the amount was 0.7% by weight. I got the wrapping paper.

Example 4 In the example 1, the internal addition chemicals of the first paper base material were changed to the pulp as follows, and the internal addition chemicals of the second paper base material was also changed to the polyamide resin in the following formulation. A packaging paper of the present invention was obtained in exactly the same manner as in Example 1 except that it was not used and the compounding amount of calcium carbonate was 30% by weight. (Internal additive) Alkyl ketene dimer (SPK-287, Arakawa Chemical Co., Ltd.) 0.2% by weight Cationic starch (Kate 302, Oji National Co., Ltd.) 1.0% by weight Polyamide resin (Polymer, Showa Polymer Co., Ltd.) Fix 301) 0.2 wt% calcium carbonate 10 wt%

Comparative Example 1 A polystyrene non-woven fabric (Tyvek 1056D, manufactured by DuPont), which has been conventionally used for a packaging bag, was used as a packaging paper for comparison. Comparative Example 2 A wrapping paper for comparison was obtained by laminating polyethylene on one side of a base paper having a basis weight of 118 g / m ² . Comparative Example 3 Wrapping paper for comparison in the same manner as in Example 1 except that the blending amount of the melamine resin as an internal chemical was changed to 0.01% by weight in the first paper base material of Example 1. Got

Comparative Example 4 Example 1 was repeated except that the oxidized starch was not applied after paper making in the preparation of the first and second paper base materials of Example 1.
A wrapping paper for comparison was obtained in exactly the same manner as. Comparative Example 5 In Example 1, the basis weight of the first paper base material is 110 g / m ^2.
A wrapping paper for comparison was obtained in exactly the same manner as in Example 1 except that. The characteristic values of the wrapping papers of Examples 1 to 4 and Comparative Examples 1 to 5 obtained as described above are as shown in Table 1, and the water resistance, bag-making process characteristics, and
The results of evaluation of printability and writability are shown in Tables 1 and 2.

[0019]

[Table 1]

[Table 2]

As is clear from the evaluation results of Tables 1 and 2, the packaging paper of the present invention exhibits good water resistance and
It was confirmed that it has excellent bag-making properties and printability, and that it has good writability. On the other hand, Comparative Example 1, which is a conventional wrapping paper, has good water resistance, but has problems with bag-making processing characteristics, printability, and writability, and Comparative Example 2 has water resistance, bag-making processing characteristics, The printability was slightly inferior. Further, Comparative Example 3 is water resistant, Comparative Example 4
Has problems in water resistance and printability, and Comparative Example 5 has problems in bag-making process characteristics and printability.

The evaluation methods of the respective properties in Table 1 are as follows, and the results are evaluated by visual evaluation as ◯ for practically good, Δ for slightly inferior, and x for practically problematic. did. (1) Water resistance: Water is applied to a finger and the surface of the paper is rubbed, and the degree of fibers on the surface is observed. (2) Bag-making processing characteristics: A paper-making machine (a Ueno Seisakusho Co., Ltd. square 2 type flatbed) is used to observe the paper transportability (curl, slip, etc.), bending property, and gluing property. (3) Printing characteristics: Paper transportability (curl, slip, etc.), ink receptivity, ink drying property, printing plate stains (paper powder) by a printing machine (sheet-fed offset 1-color printing machine manufactured by Komori Printing Co., Ltd.) (Due to occurrence, etc.) (4) Writability: Water-based ink (Super Park, Super Q
Observing ink bleeding and bleeding when writing on the paper surface (first paper substrate side) with a variant drawing pipe pen using red ink).

[0022]

Since the wrapping paper of the present invention has the structure as described above, it maintains good water resistance and
It has a remarkable effect that it is excellent in bag-making processing characteristics, and also has good printability and writability.
It is suitable as a packaging bag used for parcels, courier service, etc.

Claims (4)

[Claims] 1. A first paper base material, a synthetic fiber sheet and a second paper base material are sequentially laminated, the first paper base material is for an outer surface, and the basis weight is 40 to 40. 100 g / m ² ,
A packaging paper having a wet tensile strength of 0.7 kgf / 15 mm or more and a surface strength of 10 A or more. 2. The wrapping paper according to claim 1, wherein the synthetic fiber sheet is a mesh-like non-woven fabric obtained by arranging polyolefin fibers so as to cross each other in a longitudinal direction and a transverse direction and fusing them. . 3. The basis weight of the second paper base material is 30 to 100.
The packaging paper according to claim 1 or 2, wherein the packaging paper is g / m ² . 4. The packaging paper according to claim 1, wherein the basis weight is 80 to 200 g / m ² .