JPS60104600A - Production of packing paper - 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 The present invention relates to a method for producing packaging paper suitable for envelopes and other shaft packaging.

As a packaging paper suitable for light packaging, it has a high degree of opacity, strong paper strength, little dimensional change due to humidity, resistance to dirt, and no paper dust or surface fuzz when used. However, it has been difficult to supply paper that satisfies all of the above requirements and has a uniform texture at a low price.

The object of the present invention is to provide a method for manufacturing packaging paper that satisfies all of the above requirements and, if necessary, can also maintain antistatic function for a long period of time. Paper is made by mixing composite fibers made of two different materials, such as plastics, and synthetic bulbs made of heat-fusible materials, such as thermoplastics, and then pressurized with heated rolls to form a film on the outer surface. The gist of this is that

Examples will be explained below with reference to the drawings. Figures 1 and 2 are cross-sectional views showing examples of composite fibers used in the present invention.
In the figure, 1 is a fiber-forming organic polymer with a relatively high melting point, such as polypropylene, and 2 is a polymer having a lower melting point than 1, such as polyethylene or ethylene-vinyl acetate copolymer, which is bathed in a hot roll as described below.

It is a meltable organic polymer. Fig. 1 shows an example in which the surface of a filament of organic polymer 1 is coated with organic polymer 2, and Fig. 2 shows an example in which the filaments of organic polymer 1.2 are aligned and integrated. is selected from polyethylene, polypropylene, polyvinyl alcohol, polyvinyl chloride, polyvinylizonate(2) chloride, polyacrylonitrile, and polyurethane fiber-forming organic polymers, and at least organic polymer 2 with a low melting point is selected from the following. Use a material that can temporarily melt when subjected to pressure and heat with a roll. The fiber length of the composite fiber is preferably about 5 to 301 ff.

A heat-fusible material such as polyethylene, polypropylene, polyvinyl alcohol,
Fiber length 10111 made of thermoplastic synthetic polymer such as polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, etc.
1 or less and 20 to 90% of synthetic pulp is mixed in water, a coloring agent is added if necessary, and paper is made. The produced base paper is in a state in which composite fibers 3 and synthetic pulp 4 are loosely entangled, as shown in FIG. This base paper 5 is shown in Figures 4 and 5.
Heat processing is performed using a four-wheel as shown in FIG. Figure 4 C. Heat roll 10 is made by combining a heat roll 5 with a cold roll (room temperature) 6 that has cushioning properties such as a rubber roll or a cotton roll.
Temperature range from 0 to 180'Q, nip pressure #-1: 5 to 7
The base paper 7 is completely passed through these two pairs of rolls and heat-processed within the range of 0 kg/cIII. Figure 5 shows the heat roll 5. The base paper 7 is passed through the temperature range of 100 to 1 FIO DEG C. and the nip pressure range of 1 to 70 kg/l:x for thermal processing. In FIG. 6, the base paper is passed through a thermal furnace 8 maintained at a temperature of 100 to 170° C. and a cushioned cold roll (room temperature) 6 for heat processing. After this thermal processing, as shown in FIG. 7, a wrapping paper is obtained in which the amphoteric surface 9.9 becomes a film and the inner surface 0 has a slightly coarse structure as shown in FIG. Figure 8 shows the state of the fibers on the film-formed amphoteric surfaces 9, 9. In this case, the temperature of the hot roll, the nip pressure of the rolls, the speed of passing the base paper through the O-ru, and the temperature of the heat furnace are The three-layer structure shown in Fig. 1 is obtained by appropriately adjusting the fibers 3 to synthetic valve numbers depending on the materials used. The relative relationship between these machining conditions is shown in Figure 9. In Figure 9, the horizontal axis is the machining speed, and the vertical axis is the hot roll temperature and nip pressure a.

The strongest wrapping paper can be obtained with a low roll temperature and a low heat roll temperature. In order to obtain the three-layer structure shown in the figure, it is necessary to process at a hot roll temperature and processing speed above point P.

In the case of FIGS. 4 and 5, it is necessary to match the temperatures of the two heat rolls 5.5 in order to prevent the processed paper from curling.

In principle, the packaging paper shown in Figure 1 can be obtained even if a single fiber made of only a low-melting point material is used instead of the composite fiber 3, but in practical terms, extreme care must be taken with the processing conditions. It is difficult to obtain an accurate three-layer structure even if the cost is paid, and this is not practical.

Made of high-density polyethylene as synthetic pulp with a thickness of approximately 1 to 3
The composition of three types of filaments using short fibers with a length of 0 mm and a length of 3 H or less, and a composite fiber of 2 denier in thickness and 1 OMH in length, consisting of an inner fiber polypropylene and an outer fiber polyethylene, and the resulting composition. The physical properties of the obtained packaging paper are shown in Table 1. Composite fiber A in Table 0 shows that the inner fiber 1 is polypropylene and the outer fiber 2 is polypropylene in FIG.
Composite fiber B is made of high-density polyethylene, Composite fiber B has the same combination as Composite fiber A, and its cross section is such that the inner fiber 1 is not in the center of the outer fiber 2, but is unevenly distributed. In FIG. 1, the inner fibers 1 are made of polypropylene and the outer fibers 2 are made of low melting point polyethylene. The composition is shown in weight ratio.

Table 2 shows the physical properties of packaging paper obtained by varying the blending ratio with the synthetic pulp described above.

Table 2 The processing conditions for the base paper in Tables 1 and 2 above are changed depending on the melting point of the outer fiber 2 of the composite fiber, and the processing conditions are 10°C below the melting point.
Set the heat roll under high temperature conditions and apply a nip pressure of 10 kg.
/c11, machining speed 20 m/mtn.

And so.

An example of the manufacturing method will be described.

When the antistatic agent is a liquid or a solid that can be bathed in water, it is diluted by dissolving it in water and applied to the paper by a method such as spraying or size pressing in a heart. In this case, it is appropriate to use an anionic or cationic antistatic agent because it has an affinity for fibers. The t+ antistatic agent may be dissolved and diluted in water to coat the paper after p-ru processing.

When the antistatic agent is a solid, it may be powdered and added to the slurry at the time of blending the paper stock.

Although the antistatic agent is easily fixed to the synthetic pulp, it is better to add an anionic or cationic surfactant to the slurry in advance to further improve its compatibility with the synthetic pulp.

The antistatic effect varies greatly depending on the type of antistatic agent, so here we will introduce two types of water-soluble powder type antistatic agents with different effects. was selected, and its half-life was measured using an honest meter after it had been left for one week and six months after antistatic treatment. As shown in Table 3, measurement result 1 shows that the antistatic effect did not deteriorate at all even after 6 months.

Table 3 Here, the conditions of the honest meter are discharge distance 15, applied voltage 10KV, measurement distance 15ff, rotation speed 15δOt)
'p, m.

From the above, it can be seen that the antistatic effect can be maintained for a long period of time, and the effect can be maintained better when the antistatic effect is infiltrated between the paper layers than when coated on the processed paper.

Since the present invention has the above configuration, the surfaces of the composite fibers and synthetic pulp are appropriately melted by the action of the hot roll or the hot furnace and the cold roll, and both sides are densified into a film shape, and the inner layer is the same as that during paper making. Coarseness (9) It has a three-layer structure, and the surface is a film, so there is no risk of paper dust or fluff, and it has a good texture, and the texture can be changed to a certain extent depending on heat processing conditions, etc. The texture is uniform, and since it uses polyolefin, a synthetic plastic fiber with low water absorption, it has good dimensional stability at room temperature without being affected by humidity.Cedar, paper strength It is strong and does not easily attract dirt, is resistant to decay caused by mold, etc., and can withstand long-term use.As it contains short fiber synthetic pulp, it does not require the addition of any white pigments, making it pure white and has good shielding properties. It can be colored and printed freely and has good printability, and antistatic treatment can be performed easily and reliably. In particular, if the outer surface is made into a film after infiltrating with an antistatic agent, the static in the paper layer can be removed. There is no risk of the anti-static agent scattering or separating into the outside world, and the anti-static performance can be maintained for a long period of time, so it can be used with confidence for storing items that do not like the adhesion of dust due to static electricity, such as magnetic disks for computer use. It has the potential to be effective.

[Brief explanation of the drawing]

(10) The figures show examples of the present invention, and FIGS. 1 and 2 are enlarged sectional views showing examples of composite fibers 3 used in the invention, FIG. 3 is an enlarged explanatory view of base paper 1, and FIG. Figures 6 to 6 are explanatory diagrams showing an example of the thermal processing process of base paper, Figure 1 is an enlarged sectional view showing the structure of the packaging paper obtained by the present invention, and Figure 8 is a diagram showing the structure of the packaging paper obtained by the present invention. FIG. 9 is an enlarged explanatory view of the outer surface portion 9, FIG. 9 is a graph showing thermal processing conditions, and FIG. 10 is an enlarged sectional view showing another example of the composite fiber 3 used in the present invention. In the figure, 5 is a hot roll, 6 is a cold roll, and 8 is a hot furnace. Agent Ide Yū (1yu) Former recruitment 21st criminal 31 nights 41ffl ￥S Zukan Otsu Zusan 7th ward Arithmetic g I'fA 1st pu 1'f? IO)! I

Claims (1)

[Claims] 1. A composite fiber made by combining two types of substances with different melting points and a synthetic pulp made of a heat-fusible substance are mixed and made into paper, and then pressurized (using heated rolls) to form a film on the outer surface. A method for producing packaging paper characterized by: 2. A method for producing packaging paper according to claim 1, which comprises adding an antistatic agent.