JPH11140799A - Opaque laminate with smooth surface and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new type paper having properties required for a future coated paper, a base paper for a pressed paper, a paper for inkjet printing or the like and capable of being readily regenerated as a pulp after using, and further to provide a method for producing the paper with a simple process. SOLUTION: The opaque laminated paper with a smooth surface comprises an opaque supporter consisting essentially of a wood and non-wood pulp, and a surface layer formed at least on one surface thereof, and the surface is produced by combining a pulp paper obtained by using a trunk stem pulp of family phyllostachys (grass).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing paper having a smooth surface.

[0002]

2. Description of the Related Art Paper having a smooth surface is considered to be suitable for precision printing, and recently, it has been newly used as a precision embossed paper of a computer, a color copy paper by ink jet, and a base paper of a pressure-bonded paper, particularly a paper having a particularly smooth surface. Applications are expanding. Since the paper obtained by the normal manufacturing method has a rough surface,
It has been used as so-called coated paper or processed paper, which is a paper whose surface has been smoothed by adding steps such as coating the surface of ordinary paper or laminating a synthetic resin.
Therefore, it has been a drawback that extra costs are required for production as compared with ordinary paper, and it is not easy to collect and recycle waste paper as compared with ordinary waste paper.

[0003]

A new type of paper which has a smooth surface and has the performance required for future coated paper, pressure-bonded paper base paper, ink-jet paper, etc., and can be easily recycled as pulp after use. It is an object to provide a method for producing paper in a simple process.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, (1) the pulp of the stem stem of a plant of the family Gramineae is mainly made of, for example, pulp made from rice straw, bagasse (sacchar of sugar cane), and corn husk, and water is added thereto. In addition, the mixture is beaten sufficiently to obtain a complete stock without any or almost no sizing treatment. Water is added to the stock to disperse the stock, which is then made into a wet paper on a wire to form a surface layer.
(2) softwood and hardwood wood pulp or bagasse pulp;
A non-wood pulp such as abaca pulp or hemp pulp is beaten in a conventional manner, the size and the addition of filler are appropriately adjusted to prepare a complete paper stock, which is sieved on a wet paper of normal thickness, and this is used as a support layer.
(3) The wet paper of the surface layer and the support layer is overlapped, and the wet paper made of the two layers is pressed to squeeze water, and the wet paper is placed on a mirror-finished dryer such as chrome plating so that the surface layer is in close contact with the wet paper and heated. And dried, and a new type of paper with a smooth two-layer surface, and (3 ') a pulp paper with two layers, an upper layer and a lower layer during papermaking, and a single layer or a support layer between the two layers as a support layer. Provided is a multilayer pulp paper which is made into a single sheet and is then laminated into a single sheet to provide a multilayer laminate having both surfaces smooth and a method for producing the same. This opaque laminate with a smooth surface can withstand precision printing like coated paper, and because it is not coated, it is a new type of precision printing paper that can well withstand intaglio printing required for banknote or securities production. It is. Further, the opaque laminate having a smooth surface has excellent ink absorption in color ink jet printing, and provides a beautiful image with little trouble.
Further, the opaque laminate having a smooth surface has a smooth surface and is positioned as a base paper for pressure-bonded paper, so that precise and beautiful printing can be performed. Since no coating treatment and no lamination treatment with plastics or the like have been performed, the pulp can be easily regenerated even once used paper.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram illustrating the configuration of an opaque laminate having a smooth surface according to the present invention. In FIG. 1, 1 indicates a surface layer, and 2 indicates a support layer. In FIG. 2, 1 indicates an upper layer, 2 indicates a lower layer, and 3 indicates a support layer. The surface layer or the upper and lower layers are made of pulp paper mainly composed of pulp of stems of grasses. On the other hand, the support layer is a pulp paper mainly composed of wood or non-wood plant pulp.
To obtain the pulp paper constituting the surface layer or the upper and lower layers,
Using the stem of a grass plant as a raw material, it is pulped and paper-milled. When rice straw, straw, or the like is used as the pulp raw material, it is desirable to separate and remove the straw leaves from the viewpoint of improving the strength of the obtained pulp and improving the drainage of the pulp. The residual rate of the leaves after removal is 30% or less, preferably 10% or less. Cutting the straw to 20 cm or less, preferably 3 to 10 cm before the wind selection is easy in operation, and is effective in removing the leaf portion from the stem portion to 10% or less. The sugarcane canine can be obtained by crushing the stems (canes) of sugarcane, squeezing and separating sap, and separating and removing pis (internodal parenchymal tissue) from bagasse (pulp cake). It can also be obtained by dividing the stem of sugar cane vertically and separating and removing the pis containing juice. In this case, a small amount of pis may be mixed in the obtained kein lining, but removing the pis improves the drainage of the obtained pulp and helps to improve the strength of the pulp paper by beating. . The mixing amount of the pis is 10% by weight or less, preferably 3% by weight or less, based on the absolute dry weight. In the present invention, kineinide mixed with 0.5 to 5% by weight of pis and sweet sorghum and corn stem bark (lined) obtained by the same treatment can be advantageously used as a pulp raw material. As the pulping method of the straw and the lined, various conventionally known chemical pulping methods using an alkaline cooking liquor such as a soda method, a kraft method, and a PA method (hydrogen peroxide-alkali method) can be used. However, use of the PA method is particularly preferred. Hydrogen peroxide and alkali (NaOH, NaH
CO ₃ , Na ₂ CO ₃ , KOH, K ₂ HCO ₃ , K ₂ CO ₃ )
This is a method using an alkaline aqueous solution containing This PA
According to the method, it is possible to obtain a pulp having a good bleaching property, a large pentosan content, a good beating property and an excellent strength. Pulp made from stems such as straw and canned stalks has large inner holes, and after beating at the time of papermaking, becomes flat when passing through a wire part, a press part and a dry part, and adheres to the pulp mutually. A pulp paper having a smooth surface and a high density and strength can be provided. Further, the surface can be highly smoothed by calendering.

The straw or canned pulp obtained as described above can be converted into bleached pulp (bleached pulp) if necessary. Pulp bleached to high whiteness no longer has hydrophobic lignin remaining, which makes the beating operation easier. The standard of beating in this case is C.I. S.
F. 100-500ml, preferably 150-350m
l. As the pulp (wet pulp) of the grasses to be subjected to the beating treatment, the main component thereof is preferably 70%.
% Or more, more preferably 810% or more, should be adjusted to be in a range of 100 mesh-on with a 20-mesh pass, preferably 80 mesh-on with a 40-mesh pass in a sieving test. In general, after separating and removing leaves or pis in advance, pulp in a preferred sieving section can be obtained only by PA cooking, but pulp in a more preferable sharp section can be obtained, but pulp having a more preferable sharp section is preferable. It can be obtained by further sieving. Pulp consisting of such sharp sections enables the strength of pulp paper to be increased without drastically reducing drainage even if the beating process is advanced, and gives clear printing, especially paper that can withstand intaglio printing. The base paper of the present invention enables the production of an opaque laminate having a smooth surface having a high degree of functionality, which enables various images to be launched by a computer using an excellent ink jet.

According to the study of the present inventor, it has been confirmed that application of this pulp for paper stock gives pulp paper which has water absorbency and does not cause ink bleeding.
In this case, the surface size and the inner surface size can be transferred to the sizing by a conventionally known method. The surface size is determined by applying a sizing agent such as glue, starch, carboxymethylcellulose (CMC), polyvinyl alcohol, alkyl ketene dimer, etc. to the surface of the paper-dried laminate, followed by drying. On the other hand, the inner surface sizing is performed by adding a sizing agent such as an alkyl ketene dimer, a rosin, an alkylstyrene polymer, or a wax to the stock. In the case of surface sizing, the amount of the sizing agent used is 0.5 to the pulp.
% Or less, preferably 0 to 0.2%. In the case of the inner surface size, the amount of the sizing agent used is 1.0% by weight or less, preferably 0 to 0.5% by weight, based on the pulp. A complete stock is prepared by adding stock components to the beaten pulp. In this case, the straw pulp and the lined pulp can be mixed with each other, but it is preferable that the pulp be obtained by the PA method. The proportion of the pulp of the gramineous plant in the total pulp is 60% by weight or more, preferably 80 to 100% by weight, based on the absolute dry weight. The complete stock can include a filler, if necessary, in addition to the pulp. Examples of the filler include China clay, titanium white, precipitated calcium carbonate, and talc. The complete stock containing the lined pulp is formed into a surface layer or a lower layer wet paper in a wire part of a paper machine, and is similarly dewatered and pressed together with a wet paper of a support formed in a press part. It is made into a sheet of laminated paper and dried in a dry part to form an opaque laminate having a smooth surface. The formation of wet paper of pulp paper will be described in more detail below. Various types of conventionally known wet paper formation for pulp paper, for example, fourdrinier, short netting, round netting, Yankee paper and twin wire paper machine, etc. A circular net portion, a twin wire portion, or the like is used. The raw material concentration of the complete stock supplied to the wire part is 0.05 to 0.6% by weight, preferably 0.1 to 0.2% by weight. When the upper or lower pulp paper is obtained as described above, the thickness of the pulp paper is 5 to 20 g / m ² , preferably 10 to 20 g.
/ M ² to give a basis weight. The thickness of the pulp paper can be adjusted by the raw material concentration, liquid volume, and / or speed of the complete stock supplied to the paper machine. The pulp paper forming the upper layer or the lower layer obtained as described above is prepared with a support and laminated and adhered thereto to form an opaque laminate having a smooth surface. The pulp paper used as the support is coniferous if the desired laminate is paper.
It is mainly made of hardwood pulp or short fiber pulp made from a plant of the Gramineae family, and is blended with long fiber pulp if desired. If the desired laminate is handmade Japanese paper or machine-made Japanese paper, the raw material pulp is mainly non-wood long fiber pulp, and if desired, short fiber non-wood pulp, wood pulp, synthetic fiber, and synthetic fiber are suitable. Mix what is cut to length.

As non-wood long fiber pulp, pulp of bast such as mulberry, mitsumata, ganpi, mulberry, jute, kenaf, etc., and pulp of leaf fiber such as abaca, banana, sisal etc. Seed pulp includes cotton pulp. One or more of these pulp are selected and mixed and beaten, or when each pulp is extremely difficult to beat, the pulp is beaten simply and then mixed. Beating with CSF at 250 to 650 ml, preferably about 450 to 600 ml, is more suitable for obtaining a final product having a low-density Japanese paper texture, in which the fibers remain without cutting.

Among non-wood pulp of short fibers such as lined pulp and rice straw pulp, and pulp of conifer and hardwood, lined pulp and hardwood pulp having a large pentosan content are C.I. S. F. After viscous beating to about 100 to 250 ml, the long fiber pulp was slightly beaten to
By mixing 30%, the viscous beaten single fiber pulp acts as an adhesive between the long fibers and has a low density, especially the large tear strength and bending strength peculiar to Japanese paper.
It is easy to obtain an opaque laminate having a smooth surface such as Japanese paper having various strengths such as tension. The pulp beaten for the Japanese paper-like support is internally sized as necessary to prevent the ink from penetrating inside and further to the back side. It is carried out by adding an alkyl ketendier, a rosin, an alkylstyrene polymer, a wax or the like as a sizing agent to the stock. Its usage is 0.1-3.0% by weight,
Preferably it is 0.3 to 1.0% by weight. A filler may be appropriately mixed into the support to increase the opacity and whiteness of the paper. Fillers include China clay, titanium white, talc and the like. When performing neutral size, it is also possible to use precipitated calcium carbonate. The complete stock obtained by the above operation is formed into a wet paper of a support layer by a wire part of a paper machine, sent to a press part together with the wet paper of the pulp paper described above, dewatered and pressed, and subjected to one sheet of paper. As described in part, the formation of a wet-paper web on the support is described in more detail below. Will be described. For the formation of a wet paper on the support, various conventionally known materials, for example, a fourdrinier paper machine, a short net paper machine, a circular net paper machine, a Yankee paper machine, a twin wire part, and the like are used. The water content of all the stock components of the complete stock supplied to the wire part is 0.1 to 1.0% by weight, preferably 0.2 to 0.5%. When the above-mentioned Japanese paper-like support is obtained, its thickness is obtained by subtracting the thickness of the surface pulp paper from the desired thickness of the product, Japanese paper-like ink jet paper, from an extremely thin to a considerably thick one. Will be obtained. Thickness adjustment during papermaking depends on the concentration, liquid volume,
Although it can be adjusted by the papermaking speed, particularly when a thick support is made, it can be adjusted to two layers, three layers or more, or can be adjusted by the papermaking speed. Raw material concentration of 12 to 25% by weight in wire part, preferably 15 to 22%
The wet paper web that has been dehydrated is sent to the wire part. Both the surface pulp paper and the Japanese paper-like support are sent to the press part,
As described above, dewatering is performed to a raw material concentration of 40 to 60% by weight, preferably 47 to 53% by weight, pressed, made into one sheet of paper, and sent to a dry part. The dry part in the manufacturing process of the opaque laminate having a smooth surface according to the present invention finishes the surface of the dryer to a mirror surface, adheres the mirror surface to wet paper to dry the paper, and finishes the surface of the paper to a smooth surface if desired. Further, if the surface is applied to a super calender, a smooth surface is formed so as to have gloss. When a lined pulp paper is formed on one side of the support layer and used for ink jetting, a minimum of one Yankee dryer is sufficient. When the lower layer and the upper layer are made smooth and both sides are used for punching, it is sufficient to use a double Yankee. Further, in the case of mass production with one unit, it is possible to process and use any mirror surface of a multi-cylinder dryer.

[0010]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The percentages described below are percentages by weight.

Example 1 An opaque laminate having two layers and having a smooth surface for single-sided recording and stamping was formed from 100% non-wood pallets. The upper layer is 100 kg of rice straw bleached PAP, 5 kg of cane indica (sugar cane thick skin) bleached PAP, corn skin bleached PAP
5 kg was placed in a beater, and water was added to make the raw material concentration 3.5%. S. F. Strong viscous beating was performed until it reached 180 m. After beating, no sizing agent or filler was added at all, diluted with water until the original concentration was 0.15%.
7% wet paper (dry matter basis weight 12 g / m ² , density 0.93
g / cm ³ ). The support layer was prepared by using a beater for 400 kg of PAP of canined, 100 kg of bleached PAP of rice straw, and 100 kg of PAP of cotton linter. S. F. After beaten to 510 ml, water was added to 50 kg of China clay and 1.5 kg of neutral sizing agent alkyl ketene dimer to make complete stock after the beating. The complete stock is diluted by adding water to a raw moisture concentration of 0.32%, and wet paper having a raw material concentration of 18% with a short net (45 g / m ^{2 in} terms of dry matter basis weight, density 0.71 g / cm ³ ). Was formed. The lower layer prepares complete stock under exactly the same conditions as the upper layer,
Wet paper was made with a circular net. The support layer and the upper and lower wet paper are
By passing the press part between the three layers without using any adhesive or the like, water was squeezed until the water content reached 51% to form one wet paper web. The wet paper was dried by heating so that the upper and lower surfaces of the wet paper and the polished surface of the dryer were in close contact with each other, to obtain a laminated paper having a smooth surface. This paper was further subjected to a surface smoothing treatment using a super calender. The obtained paper had a Beck smoothness of 1,520 seconds, a whiteness of 87.1% and a breaking length of 5.
2 km, width 2.8 km, specific burst strength 3.7, specific tear 112. Using a 360 x 360 dpi color copy machine capable of embossing the paper, a picture was copied on the front side and a photograph was copied on the back side, and a clear image was obtained. In addition, a clear image was obtained by color launch of a digital camera. By applying color printing and applying an adhesive, a clear pressure-bonded postcard was obtained.

Example 2 An opaque laminate having three layers and having smooth upper and lower layers was produced. That is, the upper layer and the lower layer have 1 bagasse AP.
The pulp was beaten in the same manner as in Example 1 to adjust the complete stock, and the upper and lower wet paper webs were respectively extracted with two circular nets. The supporting layer is made by beating non-wood pulp as in Example 1, adjusting wet paper web with a fourdrinier paper machine, dehydrating with a press part without using any adhesive, etc. The paper was dried with a two-cylinder Yankee dryer whose upper and lower surfaces were mirror-finished, and 350 kg of paper having smooth surfaces was prepared. The resulting paper had a small difference between the front and back sides, with the front and back sides having Bekk smoothness of 1,030 seconds and 975, respectively. The whiteness was 86.2% and the density was 0.76 g / cm ³ .
Breaking length 5.5km, specific burst strength 3.8, specific tear strength 10
Nine. This paper can be used as it is as inkjet paper for advanced color copying, it can be used as a new security paper by letterpress, intaglio and offset printing, it can be used as a substitute for coated paper, and it can be used as base paper for pressure-bonded paper I knew that.

Example 3 A single-sided, smooth, opaque laminate of Japanese paper style was produced by making two layers. In other words, the upper layer is K-lined bleached PAP80k
g, rice straw bleached PAP 20%, mixed and beaten with a beater, CSF. 170 ml of complete stock was prepared. This was made into a wet paper with a dry basis weight of 15 g / m ² through a circular net. The supporting layer is 270 kg of abaca bleached PAP, rice straw bleached PAP
27 kg of bleached PAP of Kineind and 27 kg of bleached PAP of Koton are beaten with a beater to a CSF of about 45 each.
The mixture was beaten to 0 ml, and a wet web having a dry basis weight of 60 g / m ² was produced with a long net. These are dehydrated in a press part without using any adhesive, etc., and the two or more layers are pressed and combined into one wet paper, and the upper layer is dried in close contact with a mirror-finished Yankee dryer, followed by super calendering To produce an opaque laminate having a smooth surface and a smooth surface on the one side.
The surface smoothness was Beck 65 seconds, the whiteness was 84.5%, the breaking length was 8.6 km, the specific burst was 5.1, and the specific tear was 196. A color photograph was launched with a digital camera and a bubble ink jet, and a very good photograph image was obtained.

[0014]

According to the present invention, the opaque laminate of non-wood pulp paper containing paper or Japanese paper having a smooth surface can be manufactured by a very simple apparatus and process without coating or processing. Because the resulting product has a smooth surface, it can be used as a base paper for pressure-bonded paper, as a precision security printing paper, as a substitute for coated paper or as a coated paper base paper, and as an inkjet paper for color copiers, color fax machines, electronic cameras and electronic equipment. Can be used for output.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional configuration diagram of an opaque laminate of the present invention.

[Explanation of symbols]

 1 surface layer 2 support layer

Claims (7)

[Claims] 1. An opaque support mainly composed of wood or non-wood pulp, and a surface layer formed on at least one surface of the opaque support. Opaque laminated paper having a smooth surface and a method for producing the same. 2. A pulp paper having a surface layer having a basis weight of 5 to 30.
The opaque laminated paper having a smooth surface according to claim 1, which has a g / m ² . 3. The smooth opaque laminated paper according to claim 1, wherein the surface of said pulp paper is treated by a calender. 4. The opaque laminated paper having a smooth surface as claimed in claim 1, wherein said pulp paper is a pulp paper mainly composed of pulp obtained by pulping grassy plants with alkaline hydrogen peroxide. 5. The opaque laminated paper according to claim 1, wherein said support layer is a paper mainly made of hemp pulp. 6. The opaque laminated paper having a smooth surface according to claim 1, wherein the pulp paper forming the surface layer has a Beck smoothness of 100 seconds or more. 7. A Japanese paper-like opaque laminated paper comprising a support layer mainly composed of wood or non-wood pulp and a surface layer made of pulp paper of grasses formed on at least one surface thereof. In the method, a wet pulp paper mainly composed of pulp of a grass plant is laminated on at least one surface of the support layer, compressed to remove moisture contained therein, and then dried on a drying drum. The method for producing an opaque laminated paper having a smooth surface according to any one of claims 1 to 6, characterized in that: