JPH11323783A - Impregnated paper containing ductility and malleability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an impregnated paper exhibiting excellent ductility and malleability due to affinity for cellulose fiber by the softening and melting of a dialcohol cellulose in thermoforming by impregnating a paper with an aqueous solution of the dialcohol cellulose of a specific structure. SOLUTION: Cellulose powder is reacted with paraformaldehyde in dimethyl sulfoxide to synthesize methyl cellulose, which is oxidized in an aqueous solution of sodium periodate to give dialdehyde cellulose, which is reduced with sodium borohydride, etc., to give a dialcohol cellulose of the formula ((n) is >=5) having a cleft structure between a carbon atom at the 2-position and a carbon atom at the 3-position of a pyranose ring of the cellulose molecule. Paper is impregnated with the aqueous solution of the dialcohol cellulose to give an impregnated paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spreadable impregnated paper impregnated with a cellulose derivative having thermoplasticity.

[0002]

2. Description of the Related Art Polyolefins, aromatic polyesters, and the like, which are consumed in a large amount in daily life, are materials derived from petroleum, which is a finite resource, and have a problem of garbage increasing year by year. As countermeasures, we are trying to reduce the burden on the natural environment by material recycling, chemical recycling, and thermal recycling by separating and collecting garbage.However, the cost and deterioration of physical properties of recycled materials and carbon dioxide emissions There is a concern about global warming caused by this and environmental pollution caused by throwing away at resorts.

[0003] Under such circumstances, attention has been paid to a material system with a low environmental and resource load. Among them, cellulose is a natural polymer resource which is present in an almost inexhaustible amount on the natural renewable earth. In recent years, the processed paper has attracted special attention and can be widely used for recycling. In recent years, in the papermaking industry, recycling of waste paper (material recycling) has been actively performed, while other combustible garbage has been generated. It can be converted to energy by thermal recycling even when it is combined with, and has the characteristic of having biodegradability inferior to general-purpose synthetic resins.

[0004] For this reason, paper continues to occupy a major position among the raw materials used for packaging materials in Japan, Europe and the United States.
In recent years, attention has been paid particularly to environmental problems. Above all, paper tray containers (hereinafter, paper trays) have been remarkably growing in place of trays using synthetic resins such as expanded polystyrene.

[0005] A paper tray is manufactured by assembling a method in which a single piece of paperboard or a processed paperboard is punched by a plunger-type box making machine and four corners of a blank are pasted, and a hot tray is pressed and formed by a special tray forming machine. It can be broadly divided into press molding methods.

The press-formed paper is controlled at a molding temperature of 0 to 250 ° C., and is hot-pressed by a mold in a press time of 0 to 5 seconds to form a tray.

As the material of the molded paper tray, there are a single paperboard, a resin-impregnated one, and a synthetic resin such as polyethylene laminated by an extruder or the like.

[0008] These paper trays formed by press molding are:
It is widely and widely deployed in fresh food, bento, cooked frozen food, steamed food, etc. For this reason,
Paper has moderate stiffness for humans, is excellent in ultraviolet blocking properties, deadfolding properties, foldability, printability, lightweight and strong, can withstand relatively low or high temperatures, and is inexpensive. It has advantages such as natural decomposition function, easy incineration and high waste disposal.

However, paper is a natural polymer having no thermoplasticity, and large elongation, ie, extensibility, is not possible even when heated like a metal or a resin. Such a partial pressure method limits its use to shallow trays and paper plates. In recent years, ornable paper trays have attracted attention, but this tray is made of heat-resistant synthetic resin (PET, mainly PBT, acrylic resin, polycarbonate, polymethylpentene) on kraft (bleached sulfate pulp) paperboard. It is made of laminated paperboard that has been heated and melted with a ruder. But this is 2
The main feature is that it has a heat resistance of about 30 ° C., and it can be said that the moldability is such that it can be squeezed a little deeper than a paper tray widely used at present.

Now, in order to impart high extensibility to paper,
It is considered that a thermoplastic substance should be included in the paper. Examples of the thermoplastic substance include synthetic polymers such as polyvinyl alcohol and polyethylene glycol, thermoplastic elastomers such as butyl rubber-grafted polystyrene and liquid rubber, and latexes such as acrylonitrile-butadiene-based polymer and styrene-butadiene-based polymer. Can be considered.

However, these have a different structure from the cellulose molecules which are the constituents of the paper, are unlikely to enter strong hydrogen bonds between the cellulose molecules forming the paper, and have low affinity. Due to this, at a high temperature during heat molding, the thermoplastic resin tends to soften and melt in the paper, and not only the breaking strength is reduced, but also the spreadability tends to be reduced. Latexes and the like are water-based emulsions, and thus have the advantage that latex easily enters with water between cellulose fibers. Latexes, thermoplastic elastomers, liquid rubbers, and the like have a T
Since the g is about -70 to 0 ° C. and the molding temperature has already been reached at room temperature, the impregnated paper is often very soft and has a strength unsuitable for containers.

From the above, suitable physical properties of spreadable paper are as follows, while maintaining the rigidity of paper at room temperature.
It is considered that a material having spreadability during molding is good. That is, it is considered that a material that has spreading in a heated atmosphere and has a high spreading rate is ideal.

A cellulose derivative having the above-mentioned properties is a cellulose derivative. Cellulose derivatives are
Since it has the same basic structure as paper, it has a very high affinity for paper and has the advantages of paper as it is. More specifically, as a resource, cellulose, which is a natural regenerated resource, is a raw material, is naturally degradable from an environmental point of view, and its disposal methods are diverse and harmless. However, many of the cellulose derivatives
Its unique basic structure, D-glucopyranose, has a structure in which β-1,4-glucosidic bonds are formed by dehydration and has low thermoplasticity. Therefore, camphor is added to cellulose nitrate by adding camphor as a plasticizer (external plasticization) or lengthening the ester chain of esterified cellulose (internal plasticization) to impart thermoplasticity. However, these have essentially no thermal melting property of the cellulose derivative itself, and have physical properties close to thermal softening properties. This is because the cellulose skeleton is composed of a rigid pyranose ring and a fragile ether bond, and is thermally decomposed before being thermally melted. Further, internally plasticized esterified cellulose is insoluble in water, and the solvent varies depending on the type of ester chain, but ketones such as acetone, organic acid esters such as methyl acetate and ethyl acetate, dichloromethane, and chloroform. It is only soluble in organic solvents derived from petroleum resources such as halogenated carbons such as acetonitrile and DMF. Therefore, when manufacturing impregnated paper with esterified cellulose derivatives, the production line must be explosion-proof and require solvent cost. And the consumption of petroleum resources is a concern.

Under these circumstances, in recent years, as an impregnating agent for imparting spreadability, which is a drawback of paper, which has been increasing in demand in terms of resource and environmental burdens in recent years, it has been proposed to use a conventional synthetic impregnating agent. Resins have excellent ductility at room temperature, but lose rigidity, which is a good point of paper, and have low affinity with paper, and thermoplasticity in a molding environment reduces the strength of paper. In addition to lowering, there was a tendency that spreadability, that is, elongation, also decreased. Therefore, it is conceivable to use a cellulose derivative which is considered to have the highest affinity for paper and has a low resource and environmental load, but many cellulose derivatives have a heat softening property but a heat melting property. Does not have sufficient spreadability. Furthermore, these esterified cellulose derivatives are only soluble in organic solvents derived from petroleum resources, and it is considered that maintenance of a production line and high solvent cost are problems.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a high affinity for paper, a high thermal melting property, and a low load on a water-soluble environment. It is an object of the present invention to provide an impregnated paper having high spreadability using a derivative as an impregnating agent.

[0016]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a dialcohol, which is a derivative having a rigid part of a cellulose skeleton, that is, a pyranose ring, which has flexibility. By using cellulose as an impregnating agent for paper, it is possible to impart unprecedented spreadability to paper by heat-melting in a molding environment of dialcohol cellulose, which has thermal melting properties and high affinity for paper. Was completed.

According to the first aspect of the present invention, there is provided a cellulose molecule impregnated with a dialcohol cellulose represented by the following general formula 1 having a structure cleaved between the carbon at the 2-position and the carbon at the 3-position of the pyranose ring. Impregnated paper having improved spreadability.

[0018]

Embedded image General formula 1 (where n is 5 or more)

<Function> The spreadable impregnated paper of the present invention is composed of a material system having a small load, both in terms of resources and environment, and has improved and improved the defects of the physical properties of the paper. That is, it is made by impregnating paper with dialcohol cellulose, which has high affinity for paper and has only one of the many cellulose derivatives having thermal fusibility and thermal fluidity, thereby imparting spreadability. Specifically, at room temperature, the impregnated paper has the original rigidity of paper which can be considered to be appropriate for humans, and has a reduced spreadability during heat molding. Also, as the impregnating solvent, it is possible to use water, and the solvent cost is low,
It has the advantage that it is easy to manufacture impregnated paper and saves petroleum resources.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The dialcohol cellulose according to the present invention has a heat melting property and a thermofluidity which can be said to be the only one among a large number of cellulose derivatives. It has moderate rigidity for human beings, which is the texture of paper, and in a molding environment, heat-melting and heat-fluidity are exhibited between cellulose fibers, and it has spreadability due to strong affinity with cellulose fibers. We were able to provide paper. In addition, dialcohol cellulose is
Since it is soluble in water, the process of producing impregnated paper can be put on the same production line as existing latex-impregnated paper, resulting in low solvent costs and low environmental impact.

The evaluation of spreadability and workability can be confirmed in an actual molding process using a press molding machine, but a simple method is a general equipment for measuring mechanical properties such as a synthetic polymer film. By measuring the elongation percentage of the impregnated paper under the molding temperature environment, it can be measured as a measure of spreadability.

The dialcohol cellulose in which the pyranose ring of the cellulose molecule is cleaved according to the present invention can be synthesized by a known method. Specifically, a method of producing dialcohol cellulose by using a reducing agent through dialdehyde cellulose by cleavage between the 2-position and 3-position carbons of the glucopyranose ring of the cellulose molecule by periodate has long been used. However, in this method, since the cellulose is insoluble in water, only a non-uniform oxidation (dialdehyde conversion) occurs, and the oxidation reaction requires a weekly time, and the degree of polymerization of the cellulose molecule is low. Reduction and side reactions occur. Therefore, a method of synthesizing dialcohol cellulose by means of a periodate oxidation reaction via methylol cellulose, which has been studied in recent years, is considered appropriate.

In the method of synthesizing dialdehyde cellulose with periodic acid via methylol cellulose and converting it to dialcohol cellulose with a reducing agent, methylol cellulose is dissolved in water in the reaction stage with periodic acid. Therefore, it reacts uniformly,
It is known that dialdehyde cellulose is synthesized in about a time. Specifically, a cellulose powder is reacted with paraformaldehyde in dimethyl sulfoxide to synthesize methylol cellulose. Next, it is oxidized in an aqueous solution of sodium periodate to obtain dialdehyde cellulose. Then, it can be further used to obtain the dialcohol cellulose according to the present invention by using a reducing agent such as sodium borohydride in water.

As described above, in the synthesized dialcohol cellulose, not only the starting material is cellulose, which is a natural regenerated resource, but also all of the reactants are suitable for saving petroleum resources. . Paraformaldehyde is a chemical product made from formaldehyde produced from methanol.Methanol is produced from synthesis gas generated in the chemical recycling process of general-purpose resins. It can be said that this material does not impose any load on the material.

The cellulose which is the raw material of the dialcohol cellulose according to the present invention may be cellulose of a higher plant, that is, LBKP (hardwood pulp) or NBKP (softwood pulp), or cotton linter derived from cotton.

Further, since the dialcohol cellulose according to the present invention is non-crystalline, the glass transition temperature and the melting temperature are close to each other in thermophysical properties.
And a phase transition is possible reversibly. Therefore, the paper impregnated with the dialcohol cellulose of the present invention has moderate rigidity at room temperature for human beings, which is an inherent advantage of paper, and the dialcohol cellulose softens and melts during thermoforming and has an affinity for cellulose fibers. Has spreadability.

Therefore, in a paper tray impregnated with synthetic resin used in a conventional shallow drawn paper container, softening of synthetic resin,
With melting, the tensile strength of the impregnated paper and the elongation tend to decrease due to the low affinity between the synthetic resin and the paper, but the paper impregnated with the dialcohol cellulose of the present invention has a low tensile strength. Although elongation decreases, elongation does not change due to the high affinity between dialcohol cellulose and paper. Also, the paper impregnated with the dialcohol cellulose of the present invention is a so-called "obable paper tray" laminated with a synthetic resin.
It can be said that it is made of a material system having more extensibility and less burden on the environment.

Next, the method for producing the impregnated paper of the present invention will be described. Since dialcohol cellulose is hardly soluble in an organic solvent and is easily soluble in water, the impregnating liquid is prepared by dissolving dialcohol cellulose in water. To use. In the case of impregnating all layers of the base paper as the impregnation method, it is considered that any of the wet web method and the dry web method, which are the existing techniques of impregnating aqueous latexes, are most suitable. The former is continuous with the paper making process, and the dialyzed cellulose is impregnated in a wet state without drying the impregnated base paper. Thick base paper can be impregnated relatively well, and is economical with one drying step. The dry web method is
It is impregnated with a base paper that has been wound off after drying with an off-machine, and a thin base paper is used. After the impregnation, the amount of adhesion is controlled with a squeezing roll, and dried with a cylinder drier or a hot air drier. When impregnating on one side, impregnation is performed using any of the usual roll coating, doctor blade coating, knife edge coating, curtain coating, gravure coating, bar coating, reverse coating, kiss coating, etc. Can be coated. The application speed and drying conditions are not particularly limited, but it is preferable to perform the application within a range that does not adversely affect the paper and the impregnating liquid of the support.

The paper used in the present invention includes Japanese paper, imitation paper, non-woven fabric, high quality paper, art paper, coated paper, pure white roll paper, birchment paper, kraft paper, or jute liner, kraft liner, coated paper for cardboard applications. A liner and the like can be mentioned, but in order to maximize the affinity between the cellulose alcohol and the dialcohol cellulose as the impregnating agent, those without a sizing agent are suitable. In addition, since internal additives such as fillers are not related to the object of the present invention, those without additives are considered to be appropriate.

[0030]

Next, the present invention will be described more specifically based on the embodiments of the present invention.

<Preparation of Raw Material of LBKP Cellulose> The method of preparing the starting raw material cellulose powder is such that a wet sheet of LBKP (hardwood kraft pulp) is disintegrated with a pulp disintegrator in accordance with JIS-P8209 and beaten in accordance with JIS-P8121. To obtain a slurry of 0.3% LBKP cellulose having a Canadian standard freeness of 411 csf.
This was filtered, and the filtered wet cellulose was dried by heating in an oven at 120 ° C. Then, the mixture was uniformly pulverized with a mixer or a homogenizer to prepare a cellulose powder as a raw material.

<Synthesis of dialcohol cellulose>
10 g of the prepared micronized cellulose and 18.5 g of paraformaldehyde in dimethyl sulfoxide (250 ml)
After stirring at 120 ° C. for 3 hours, the resulting solution was poured into a large excess of methanol to obtain a precipitate of methylol cellulose. This is repeatedly washed with methanol,
About 60 g of the squeezed methanol was dissolved in 500 ml of an aqueous solution of sodium metaperiodate (17.15 g), and an oxidation reaction was carried out at 20 ° C. for about 10 hours in a dark place. Excess sodium metaperiodate was decomposed. This solution was poured into methanol to obtain a precipitate of dialdehyde cellulose. Then, this dialdehyde cellulose is added to water (400 ml).
While stirring at about 5 ° C., 160 g of an aqueous sodium borohydride solution (NaBH4 / Water = 8 g / 2
00 ml) was added dropwise in about 1 hour, and a reduction reaction was carried out for about 2 hours. Then, dilute acetic acid was added to decompose excess sodium borohydride. The reaction mixture was poured into cold methanol to obtain a dialcohol cellulose precipitate. This was filtered, washed repeatedly with methanol, and dried in an oven at 60 ° C. for about 1 hour. The yield was about 4.8 g (yield = about 48%).

Next, examples of the impregnated paper using the dialcohol cellulose of the present invention will be described. The base paper of the impregnated paper is used to measure the exact effect of the impregnating agent on the cellulose fibers.
"Filter paper", which is a pure pulp paper of no size and containing no internal additives, was used.

<Example 1> A filter paper (ADVANTEC Toyo Co., Ltd.) was dissolved in an aqueous solution in which the dialcohol cellulose according to the present invention synthesized in the preceding section was dissolved in 300 ml of water at a solid content ratio (N.V.) = 10 wt%. No. 2) 10c
m × 5 cm, and immerse it in an oven at 110 ° C. for 5 minutes.
After drying for minutes, an impregnated paper was prepared.

<Comparative Example-1> The filter paper (No. 2 manufactured by ADVANTEC Toyo K.K.) used in Example-1 in which the impregnating liquid according to the present invention was not immersed was used as Comparative Example-1.

<Comparative Example-2> (Impregnated paper of latex) As an impregnating liquid, an acrylate latex (Nippon Zeon) was used.
Nipol LX854E, trade name; V.
= 45 wt% aqueous solution) Filter paper (ADVANTEC Toyo K.K., No. 2) 10 cm x 5 in 300 ml of emulsion
cm was immersed and dried in an oven at 110 ° C. for 5 minutes to produce an impregnated paper.

<Comparative Example-3> (Impregnated paper of latex) As an impregnating liquid, a styrene-butadiene-based latex (trade name: Nipol 2570X5, manufactured by Zeon Corporation)
N. V. Filter paper (ADVANTEC Toyo Co., Ltd., No. 2) 1 in 300 ml of emulsion
0 cm × 5 cm was immersed and dried in an oven at 110 ° C. for 5 minutes to produce an impregnated paper.

<Comparative Example-4> (Impregnated paper of water-soluble polymer) As an impregnating liquid, polyethylene glycol 200 (manufactured by Kanto Chemical Co., Ltd., average molecular weight specification: 200) was added to 300 ml of water in a solid content ratio (N.V. ) = 10 wt% dissolved in an aqueous solution, filter paper (ADVANTEC Toyo Co., Ltd., No. 2) 1
It was immersed in 0 cm × 5 cm and dried in an oven at 110 ° C. for 5 minutes to produce impregnated paper.

<Comparative Example-5> (impregnated paper of water-soluble polymer) As an impregnating liquid, polyethylene glycol 20000 (manufactured by Kanto Chemical Co., Ltd., average molecular weight specification: 20,000) was used in water 30.
A filter paper (manufactured by ADVANTEC Toyo Co., Ltd., N.V.) was dissolved in an aqueous solution having a solid content ratio (N.V.) = 10 wt% dissolved in 0 ml.
o. 2) 10 cm × 5 cm was immersed and dried in an oven at 110 ° C. for 5 minutes to produce impregnated paper.

<Comparative Example-6> (Impregnated paper of thermoplastic elastomer) As an impregnating liquid, a polyurethane-based thermoplastic elastomer (trade name; Pandex-T-, manufactured by Dainippon Ink Co., Ltd.)
5202) to 300 ml of toluene in a solid content ratio (N.V.).
= 10 wt% dissolved in a filter paper (ADVAN
No. 2) manufactured by TEC Toyo Co., Ltd. No. 2) 10 cm × 5 cm was immersed and dried in an oven at 110 ° C. for 5 minutes to prepare an impregnated paper.

<Comparative Example-7> (Impregnated Paper of Thermoplastic Elastomer) As an impregnating liquid, a polybutadiene-styrene-based thermoplastic elastomer (trade name; manufactured by Asahi Kasei Corporation; trade name: Tuftec H-)
1042) in 300 ml of toluene and a solid content ratio (N.V.).
= 5 wt% dissolved in a filter paper (ADVANT)
No. 2) 10 cm × 5 cm was immersed in EC Toyo Co., Ltd., and dried in an oven at 110 ° C. for 5 minutes to prepare impregnated paper.

<Comparative Example-8> (Impregnated Paper of Thermoplastic Elastomer) As an impregnating liquid, a polystyrene-isoprene-based thermoplastic elastomer (manufactured by Nippon Zeon Co., Ltd., trade name: Quintac-3433) was mixed with 300 ml of toluene in 300 ml of toluene. Ratio (N.
V. ) = 5 wt%, and filter paper (ADV)
No. 2) manufactured by ANTEC Toyo Co., Ltd. 10 cm × 5 cm was immersed and dried in an oven at 110 ° C. for 5 minutes to prepare an impregnated paper.

Comparative Example-9 (Liquid Rubber Impregnated Paper) As an impregnated paper, a polybutadiene-based hydrogenated liquid rubber (manufactured by Nippon Soda Co., Ltd., trade name; GI-1000) was mixed with 300 ml of ethyl acetate in a solid content ratio. (N.V.) = 10 wt%, and a filter paper (ADVANTEC Toyo (
No. 2) 10cm x 5cm is immersed,
It was dried in an oven at 10 ° C. for 5 minutes to produce an impregnated paper.

Comparative Example 10 (Impregnated Paper of Liquid Rubber) As an impregnated paper, a polybutadiene-based liquid rubber (Nippon Soda (
Co., Ltd., trade name: CI-1000)
A filter paper (manufactured by ADVANTEC Toyo Co., Ltd .;
2) 10 cm × 5 cm was immersed and dried in an oven at 110 ° C. for 5 minutes to produce impregnated paper.

<Test Example-1> (Evaluation Test for Breaking Strength and Elongation of Impregnated Paper) JIS P8 for measuring tensile strength and elongation of impregnated paper
With reference to 113 “Testing method for tensile strength of paper and paperboard”, evaluation was carried out using a Tensilon universal testing machine of the RTC series manufactured by Orientec Co., Ltd. in accordance with JIS B7721 “Tensile testing machine”. Further, in order to estimate the tensile strength and the elongation at the time of actual heat molding, an environmental temperature of 100 to 200 ° C. was set in a high and low temperature constant temperature bath for Tensilon manufactured by MEC Corporation. The elongation was defined as the elongation at break (%).
Next, the tensile measurement conditions will be described.

Measurement conditions; load cell: 100 kgf Test speed (crosshead speed): 10 mm / min Environmental temperature: room temperature (about 20 ° C.), 4 points of 100 ° C., 150 ° C., 200 ° C. Number of tests: 3 times Initial load point (0.5fs%) Initial sample length: 100.0mm Sample width: 15mm

Next, the measurement results are shown in Table 1.

[0048]

[Table 1]

From the results shown in Table 1, it can be seen that the impregnated paper of the dialcohol cellulose according to the present invention has a lower impregnation amount of 17% both at room temperature and at a molding temperature than the base paper of Comparative Example 1. It was found that elongation and tensile strength were greatly improved. In addition, it was found that the impregnated paper of the dialcohol cellulose according to the present invention showed little change in elongation even under heating, due to the high affinity between the dialcohol cellulose as the impregnating agent and the cellulose fibers. Compared to Comparative Examples 2 and 3, which are latex-impregnated papers, latex-impregnated papers show a very high elongation at room temperature, but at molding temperatures, the elongation decreases as the tensile strength decreases. ,
The low affinity with the cellulose fiber was considered. Also,
The Tg of these latexes is in the range of -70 to -20 ° C, and their impregnated paper has tackiness, and it is considered that continuous winding is impossible if production is taken into consideration. Compared to Comparative Examples 4 and 5, which are water-soluble polymer-impregnated papers, the water-soluble polymer-impregnated papers have lower elongation and tensile strength both at room temperature and at molding temperatures, and are related to the present invention. The superiority of those impregnated with dialcohol cellulose was observed. Compared with Comparative Examples 6, 7, and 8, which are impregnated papers of a thermoplastic elastomer, it was confirmed that the elongation at a molding temperature and the tensile strength of the dialcohol cellulose impregnated paper according to the present invention were superior. Was done.
When compared with Comparative Examples 9 and 10, which are liquid rubber-impregnated papers,
It was found that the liquid rubber-impregnated paper had lower elongation and tensile strength at room temperature or at the molding temperature than the dialcohol cellulose-impregnated paper according to the present invention. From the above results, the dialcohol cellulose impregnated paper according to the present invention, at room temperature, while having the rigidity of the original paper or more, the affinity between the impregnating agent dialcohol cellulose and cellulose fibers From the height, it was found that there was no decrease in spreadability even at the molding temperature, that the original good point of the paper was not impaired, and that the drawability could be improved. Further, it is considered that if the impregnation amount of the dialcohol cellulose is further increased, the elongation percentage is also improved.

[0050]

The spreadable impregnated paper of the present invention, that is, the paper impregnated with dialcohol cellulose, is composed of a drug system that does not burden the environment, that is, pyranose, which is a rigid site of cellulose molecules. It has a structure in which the ring is cleaved between the 2- and 3-position carbons and has a heat-melting property at around 100 ° C. Due to its structure, it has a very high affinity for cellulose fibers and can be molded at about 150 ° C. It has good spreadability even in the temperature range. Furthermore, since dialcohol cellulose is soluble in water, the impregnating solvent can be water, and there is no need to make the production line explosion-proof, so that the solvent cost is low and it is environmentally friendly. In addition, water-dispersible latex-impregnated paper is soft at room temperature, is not suitable for paper containers, and has a tackiness and cannot be produced by winding. At room temperature, the paper maintains the rigidity that is appropriate for human beings or higher. Therefore, the paper impregnated with the dialcohol cellulose of the present invention does not impair the original goodness of the paper, has less environmental impact than conventional synthetic resin-impregnated or laminated shallow draw paper trays, and is discarded. It has excellent processability and is suitable as an extended paper that can be squeezed deeply.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junichi Kanaga 1-5-1, Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Inventor Hiroshi Kawasaki 1-15-1 Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd.

Claims (1)

[Claims] 1. A stretchable structure impregnated with dialcohol cellulose, represented by the following general formula 1, having a structure cleaved between carbons 2- and 3- of the pyranose ring of a cellulose molecule. Impregnated paper. Embedded image General formula 1 (where n is 5 or more)