JPH0351396A - Functional paper - Google Patents

Abstract

PURPOSE:To obtain functional paper useful as filter, etc., exhibiting deodorant effect in a wide temperature range from low temperature to high temperature containing specific amount of specific calcium phosphate-based compound as a filler. CONSTITUTION:10-80wt.% calcium phosphate-based compound (preferably apatite, tricalcium phosphate or tetracalcium phosphate) comprising a ratio of Ca/P=0.8-2.0, preferably 1.5-1.67 is contained in the aimed functional paper. Besides, said calcium phosphate-based compound is preferably composed of secondary particles having 0.1-30mum averaged particle diameter and made by drying or burning at 500-1300 deg.C after mixing.

Description

[Detailed description of the invention] "Application field" The present invention relates to functional paper that can be used in various fields.

"Prior Art and its Problems" Paper-making fillers are used to improve paper opacity, smoothness, writability, ink receptivity, etc. in the production of ordinary white paper. Clay, talc, titanium white, calcium carbonate, etc. are known.

It is also known to produce so-called ceramic paper using papermaking techniques from bulbs, aggregates and fixatives. However, conventionally, it has not been possible to produce ceramic paper that is as flexible as paper.

Furthermore, as a paper with specific functions, JP-A-59-9
Japanese Patent No. 5931 proposes a paper containing fine-grain crystalline aluminum orthophosphate produced by a specific method and capable of adsorbing malodorous components. However, this paper only adsorbs malodorous components such as ammonia, but cannot adsorb other components.

``Object of the Invention'' The present invention aims to provide not only general paper for writing, printing, packaging, etc., but also functional paper having various adsorption functions.

"Structure of the Invention" The functional paper according to the present invention has a Ca/P ratio of 0.8 as a filler.
~10-80% by weight of ZO calcium phosphate compounds
It is characterized by containing.

The calcium phosphate compounds used in the present invention include C
a/P ratio=0.8-2.0, preferably 1.0-2.0
, more preferably 1.5 to 1.67 calcium phosphate compounds, such as various apatites such as hydroxyapatite and fluoroapatite, tricalcium phosphate,
Examples include tetracalcium phosphate, which can be used alone or as a mixture.

In the present invention, it is preferable to use the above calcium phosphate compound as a powder consisting of secondary particles having an average particle size of 0.1 to 30 μm. If the average particle size is smaller than 0.1 μm, the particles will fall together with water from the screen of the paper machine during paper making, and if it exceeds 30 μm, they will be too heavy and difficult to disperse uniformly. Such secondary particles have a particle size of 1
It is formed by agglomeration or sintering of 00 to 10,000 primary particles.

After the synthesis of the calcium phosphate compound used in the present invention,
Use dried as is or 500-130
It can be used after being fired at 0°C.

Furthermore, the particles of the calcium phosphate compound may be porous. Porous particles of a calcium phosphate compound can be produced by various methods using crystal particles of a calcium phosphate compound wet-synthesized by a known method as a raw material. For example, a slurry in which raw material particles are suspended is directly granulated into secondary particles by spray drying, or additives such as a viscosity modifier, heat-burning organic compound particles, or fibers are added to this slurry and then spray-dried. It is granulated into secondary particles by methods such as. These secondary particles are suspended in a slurry again and wet-molded, or formed into a block by dry-molding using pressure. At this time, an organic compound that is burnt out during firing to form pores may be added. Even without additives, the pore size can be controlled by adjusting other conditions such as firing temperature.

The obtained block body is fired in a temperature range of 500°C to 1300°C. If the temperature is less than 500°C, the organic compound will not be sufficiently burned away and the block will not be sufficiently sintered. Also, bake 1
If the temperature is higher than 300°C, the sintered body may become too dense or the calcium phosphate may decompose.

After the block body thus fired is crushed, it can be classified to obtain particles of a required particle size.

When using porous particles, the pore size varies depending on the intended use, but especially when the purpose is to separate microorganisms such as viruses, the pore size needs to be 0.01 μm or more. It is.

In addition, the porosity of the porous particles is preferably 10 to 75%; if it is less than 10%, a sufficient surface area cannot be obtained, and if it exceeds 75%, the porous particles cannot have enough strength to withstand use. I won't be able to do it.

When the functional paper of the present invention is used to separate cells, microorganisms, etc., the surface of the calcium phosphate particles used may be coated with polysaccharides such as biologically derived hyaluronic acid, chondroitin sulfate, chitin derivatives, fibronectin, osteonectin, etc. It is also possible to partially adsorb polysaccharides, proteins, and one or more of their derivatives to modulate the physicochemical or immunological properties of the particle surface and skillfully change the adsorption activity.

The functional paper of the present invention needs to contain 10 to 80% by weight of the above calcium phosphate compound. If it is less than 10% by weight, the intended function of the functional paper will not be fully exhibited, and if it exceeds 80% by weight, it will be difficult to make paper.

Calcium phosphate compounds are effective against various animal and plant cells such as viruses and bacteria, as well as biopolymer substances, malodorous components,
It has an adsorption effect on various substances such as tobacco tar. Therefore, the functional paper according to the present invention has an adsorption effect based on the properties of the calcium phosphate compound added as a filler.

Therefore, an appropriate amount of the calcium phosphate compound to be used can be appropriately selected within the above range depending on the intended use.

As the raw material pulp, it is preferable to use pulp slurry that has been beaten to a Canadian standard filtered water content of 200 to 700 cc.

Further, when the functional paper of the present invention is used as a deodorizing paper or a filter, it can be perforated using a needle punch or the like in order to improve permeability to gas or liquid. In the present invention, a calcium phosphate compound with a high adsorption effect is dispersed in the paper, so even if holes are made in the paper, the substance to be adsorbed will not pass through the holes unless the holes are too large.

Furthermore, conventionally used fillers such as clay, talc, titanium white, calcium carbonate, etc. can also be used together with the calcium phosphate compound.

As filler addition methods, an internal addition method and a coating method are known. Both methods can be used to produce the functional paper of the present invention, but in order to exhibit the adsorption effect of calcium phosphate compounds, it is necessary that the compounds are not completely coated. be. Furthermore, it is desirable that the particles used as a filler have a large surface area. As described above, porous particles having fine pores can be obtained by aggregating or sintering 100 to 10,000 primary particles. By controlling the pore size, the specific surface area can be increased to 1rr? It can be adjusted within the range of /g to 150rd/g. Furthermore, when a coating method is employed, it must be applied to the base paper in combination with an adhesive that forms a three-dimensional network structure.

In addition, in the case of an internal addition method, filler is added to valve slurry dispersed in a large amount of water. At this time, if necessary,
A fixing agent can be added to suppress filler run-off. As a fixing agent, modified polyethyleneimine,
Examples include modified polyacrylamide, sodium alginate, gum arabic, positive starch, aluminum sulfate, and potash bright bread. The amount of the fixing agent used can be appropriately selected depending on the type of the fixing agent and the amount of the calcium phosphate compound used.

In the present invention, it is also possible to use sizing agents, dyes, paper strength enhancers, etc. that are commonly used in papermaking processes.

The functional paper of the present invention can be produced by adding calcium phosphate compound powder and other additives to the valve slurry and thoroughly mixing them, and then using a conventional paper machine. During paper making, a surfactant can be added to the slurry in order to disperse the calcium phosphate compound well in water. The surfactant can be appropriately selected from anionic, cationic, or nonionic surfactants in consideration of other additives and the like.

The functional paper of the present invention preferably has a final basis weight of 20 g/rd or more.

The functional paper of the present invention has a high adsorption effect based on the properties of the calcium phosphate compound contained as a filler, and can be used mainly for the following purposes.

(a) Deodorizing paper Shows a deodorizing effect in a wide temperature range from low to high temperatures, and is useful for refrigerators, toilets, garbage containers in the kitchen, sanitary products such as diapers, sanitary products, pads for pressure sores, and even shoe insoles. It is effective as deodorizing paper or deodorizing aromatic paper.

Furthermore, the functional paper according to the present invention adsorbs harmful gases such as carbon oxide and hydrocarbon gases, so when installed in the air vent of an air conditioner, it can eliminate bad odors at the time of startup, and it can also be used to absorb harmful gases such as carbon oxide and hydrocarbon gases. It can be installed at the exhaust port to eliminate fuel oil odor and exhaust gas odor. The deodorizing paper of the present invention can be used not only for household use as described above, but also for installation in places where malodorous components are generated, exhaust vents, etc. in various factories.

The functional paper of the present invention has an adsorption effect on biopolymer substances, bacteria, viruses, animal and plant cells, harmful gases, malodorous components, dust, mist, etc. in gases or liquids, so the functional paper of the present invention has Can be used as a filter in various products. For example, air purifiers, water purifiers, deodorizing devices, bacterial and virus sieves, cell separators,
It can be used as a filter for serum filters, protein removal filters, cigarette filters, masks, etc.

Since the functional paper of the present invention is in the form of a sheet, it can be easily replaced if its adsorption capacity decreases due to use. For example, when used in a mask, the filter of the present invention can be easily attached by sandwiching it between the gauze of a commercially available gauze mask, or by attaching a gauze pocket and placing it inside the gauze mask. It can also be easily replaced. When used in masks, the filter of the present invention can adsorb bacteria and viruses and prevent them from entering the human body, so it can be expected to have a significant effect during influenza epidemics.

(C) Adsorbent Since the adsorbent has biocompatibility and adsorbs biopolymer substances, it can be used as an electrophoresis opening paper, a protein concentration opening paper, and a chromatography base material, such as a paper chromatography opening paper.

(d) Biomaterials can be used in fracture tapes, artificial skin, artificial blood vessels, artificial tracheas, sustained drug release materials, etc.

(e) Food packaging paper) Materials for bioindustry It can be used as a cell culture substrate, an immobilized carrier for enzymes and microorganisms, a hydroponic culture substrate, a bioreactor, etc.

((To) It can be used as a base material for medical-related clinical test strips, bandages, transdermal absorption preparations, etc.

"Embodiments of the Invention" Next, the present invention will be described based on Examples, but the present invention is not limited thereto.

Example 1 Softwood bulb and hardwood bulb were mixed at a weight ratio of 7:3 and beaten to a Canadian standard freeness of 360 cc. This bulb was dispersed in water to prepare a bulb slurry with a concentration of 0.3% by weight, and synthesized by a wet method with a Ca/P ratio of 1.
67, 0.7% by weight of calcium phosphate (hydroxyapatite) having a specific surface area of 45 m/g and an average particle size of 2 μm was added, and paper was made in accordance with JIS-P8209.

The calcium phosphate content of the resulting paper product was 70% by weight, and the basis weight was 85g/rr? Met.

Example 2 Using the same bulb as in Example 1, a bulb slurry with a concentration of 0.5% by weight was prepared, and 0.5% by weight of the same calcium phosphate as in Example 1 was added, and paper was made in the same manner as in Example 1.

The resulting paper product had a calcium phosphate content of 50% by weight and a basis weight of 93 g/rrf.

Example 3 Using the same valve as in Example 1, a valve slurry having a concentration of 0.7% by weight was prepared, and 0.3% by weight of the same calcium phosphate as in Example 1 was added, and paper was made in the same manner as in Example 1.

The resulting paper product had a calcium phosphate content of 30% by weight and a basis weight of 101 g/rrr.

Example 4 Only the softwood bulb was beaten to a Canadian standard freeness of 650 CC. Paper was made in the same manner as in Example 2 using this valve.

The resulting paper product had a calcium phosphate content of 50% by weight and a basis weight of 103 g/rrf.

Example 5 The same valve slurry as in Example 4 was prepared, and 0.5 weight of calcium phosphate (tricalcium phosphate) synthesized by a wet method with a Ca/P ratio of 1.5 and a specific surface area of 105 I/g and an average particle size of 1 μm was added. % was added, and paper was made in the same manner as in Example 1.

The resulting paper product had a calcium phosphate content of 50% by weight and a basis weight of 105 g/rd.

Example 6 The same valve slurry as in Example 4 was prepared, and calcium phosphate (hydroxyapatite) was synthesized by a wet method and then calcined at 800°C with a Ca/P ratio of 1.67, a specific surface area of 10rd/g, and an average particle size of 8 μm. was added in an amount of 0.5% by weight, and paper was made in the same manner as in Example 1.

The resulting paper product had a calcium phosphate content of 50% by weight and a basis weight of 98 g/rd.

Example 7 Using the same bulb as in Example 4, a bulb slurry with a concentration of 0.3% by weight was prepared, and 0.3% by weight of the same calcium phosphate as in Example 1 was added, and paper was made in the same manner as in Example 1.

The resulting paper product had a calcium phosphate content of 50% by weight and a basis weight of 48 g/rd.

Test Example 1 This example shows a test using the functional paper produced in Examples 1 to 7 as a virus adsorbent.

In this test example, influenza virus PR8 was used suspended in physiological saline. Moreover, the titer was measured by the following method.

How to measure titer: When the influenza virus attaches to red blood cells, these red blood cells agglutinate with each other. Using this reaction, the virus suspension was serially diluted 2 times, 4 times, 8 times, 16 times, etc. with physiological saline (0.9% sodium chloride aqueous solution), and the same amount The titer of the stock solution (liquid before dilution) is evaluated by mixing it with a 0.4% chicken red blood cell suspension to cause an agglutination reaction.

Operation: Cut the functional paper prepared in Examples 1 to 7 into a circle with a diameter of 5 cn+, attach it to a funnel, and suspend the influenza virus PR8 at 3 mI each. The titer of the virus suspension that flowed out from the funnel was measured using the method described above. The results are shown in Table 1.

(See the margin below) The titer in Table 1 is proportional to the virus concentration in each effluent, and as is clear from the above results, compared to the virus concentration before passing through the paper, the functional paper of the present invention The virus concentration in the liquid that passed through the tube was reduced to 1/16 at the highest and to 1/2 at the lowest.

Test Example 2 This example shows a test in which the product paper produced in Example 1 was used as deodorizing paper.

The product paper produced in Example 1 was cut to a size of 25an x 25an, and numerous holes were punched with a needle to obtain deodorized paper. 1st
As shown in the figure, this deodorizing paper 1 was adhered to a square box 2 on three sides, and stacked in four layers on top and bottom. The non-adhesive portions 3 of the upper and lower deodorizing papers 1 to the box 2 were alternately located at both ends of the box 2 to form a zigzag air flow path. This was attached as a filter to the outlet of an air conditioner that produces a bad odor, and six people compared the odor before and after attaching the filter, and evaluated it according to the following criteria. The results are shown in Table 2.

Note that in FIG. 1, arrows indicate air flows.

Odor judgment criteria A: It smells bad (it has almost stopped smelling).

B: Odor was reduced.

C: No change.

D: The smell became stronger.

Table 2 Example 8 The same pulp as in Example 4 was dispersed in water to prepare a valve slurry with a concentration of 0.5% by weight, with an average particle size of 6.2 μm, a porosity of 63%, and a Ca/P ratio of 1.5. Average pore diameter of 0.1μm
0.5% by weight of porous tricalcium phosphate was added thereto, and paper was made by hand-making using an experimental paper machine. The resulting product paper has a tricalcium phosphate content of 50% by weight and a basis weight of 99g.
/rrr.

Test Example 3 A test was conducted using the product paper produced in Example 8 as a filter. The product paper was cut into a circle with a diameter of 45 mm, and after mounting it on a filter holder, the apparatus shown in FIG. 2 was constructed. FIG. 2 shows a system diagram of a deodorizing device incorporating the above-described filter, and the illustrated device includes a Tetravac 4, a filter holder 5 equipped with a filter 5a, and a pump 6.
, a flowmeter 7, and a tetravac 8 are successively connected through tubes.

Ammonia gas is sucked from a tetra bag 4 containing ammonia gas as an original odor while controlling the flow rate with a pump 6 and a flow meter 7 connected to the rear stage of the filter holder 5.
After passing through the filter 5a, the gas was collected in a tetravac 8 downstream of the flow meter 7. At this time, filter 5
The amount of gas passed through a was set to 1047. Further, the concentration of the gas before and after passing through the filter was determined by measuring the concentration of the gas in each Tetravac containing the original odor and the inhaled gas using the detection tube method. The results are shown in Table 3.

Table 3 The removal rate in Table 3 represents the percentage of ammonia gas out of the original odor that was adsorbed by the filter. As is clear from Table 3, 91% or more of the gas was adsorbed, and the functional paper of the present invention has an extremely excellent odor removal effect when used as a filter.

"Effects of the Invention" The functional paper according to the present invention has flexibility similar to ordinary paper, so it is easy to handle. In addition, the functional paper of the present invention not only has scales for writing and printing, but also has a high adsorption effect based on the properties of the calcium phosphate compound added as a filler. In addition to containing malodorous components such as
Based on the biocompatibility of calcium phosphate compounds, it has a high adsorption effect on various animal and plant cells, viruses, cell tissue fragments, biopolymer substances, etc.

In addition, by increasing the content of calcium phosphate compounds,
It can also be made of nonflammable functional paper.

The functional paper of the present invention has a wide range of uses, such as deodorizing paper, filters, adsorbents, biomaterials, food broadcasting papers, bioindustry materials, medical tools, etc., based on its various adsorption effects.

When the functional paper according to the present invention is used as a deodorizing paper, it exhibits a deodorizing effect in a wide temperature range from low to high temperatures, and can be used in a wide range of applications.

Furthermore, the functional paper of the present invention is aesthetically pleasing because the main component, calcium phosphate, is white.
Alternatively, it can be made of colored paper, patterned paper, or other material with high product value.

Furthermore, when using the functional paper of the present invention as a filter,
It is inexpensive, has a simple structure, is easy to manufacture and handle, and can capture not only the oral side of solid substances but also gaseous substances, bacteria, viruses, animal and plant cells, etc. at the same time. Furthermore, since the functional paper of the present invention is in the form of a sheet, it is easy to attach and detach, and it can be easily replaced whenever the adsorption capacity decreases due to use.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a filter using the functional paper produced in Example 4, and FIG. 2 is a system diagram of a deodorizing device incorporating the functional paper produced in Example 8 as a filter. Explanation of symbols 1... Deodorizing paper, 2... Box, 4 and 8... Tetravac, 5... Filter holder 5a... Filter/flow meter

Claims (4)

[Claims] (1) A functional paper characterized by containing 10 to 80% by weight of a calcium phosphate compound having a Ca/P ratio of 0.8 to 2.0 as a filler. (2) Calcium phosphate compound has an average particle size of 0.1 to 3
The functional paper according to claim 1, which is a secondary particle of 0 μm. (3) The functional paper according to claim 1 or 2, wherein the calcium phosphate compound is apatite, tricalcium phosphate, tetracalcium phosphate, or a mixture thereof. (4) The functional paper according to claim 1, wherein the calcium phosphate compound is synthesized and then dried or calcined at 500 to 1300°C.