JP3408320B2 - Antifouling agent for papermaking dryer process - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when applied to a papermaking dryer process, prevents paper dust and pitch from adhering with a very small amount of use, thereby improving paper quality and productivity. The present invention relates to an antifouling agent capable of improving the antifouling property. [0002] In recent years, in the production of paper, the use of recovered waste paper has increased for the purpose of reusing resources, and the amount of internal additives has increased in ordinary papermaking. Operation troubles due to dirt on the canvas and dryer have become noticeable. In particular, during core and liner papermaking, operation troubles due to adhesion of sticky pitches on which gums, hot melts, paper strength agents and the like have grown, and adhesion of dirt such as paper powder are increasing. That is, canvas dirt causes troubles such as lowering the air permeability, causing poor drying, making the moisture profile non-uniform, or transferring and attaching pitch to paper.
It has become unusable in about six months and has to be replaced. Dryer stains cause problems such as poor drying of the paper, uneven treatment of the paper surface, peeling of the paper (partial loss of the paper surface), and breakage (breakage) of the paper. These troubles cause deterioration in paper quality and productivity. As a countermeasure, the brush is washed with a brush or a high-pressure water washing machine on the canvas, and the dryer is treated with Teflon or a doctor to remove the dirt physically attached to the surface. Although a method has been tried, a sufficient effect has not been obtained. Japanese Patent Laid-Open No. 4-130190 discloses an oil-in-water type (O / W type) of an oily substance on the surface of a dryer.
A method has been proposed in which an emulsion is sprayed to form an oil film layer having lubricity, thereby preventing contamination and improving productivity. The use of an oil-in-water type (O / W type) in the above method is for the purpose of reducing flammability. [0005] However, in the above-mentioned conventional method, a certain effect can be recognized when the oily substance is contained in the emulsion at several percent or more, but the oily substance is contained in the emulsion. When the content is only about 0.5% or less, a sufficient oil film layer is not formed, so that the effect of preventing adhesion of dirt becomes extremely low. That is, in this method, it is necessary to use an extremely large amount of an oily substance, so that the cost is extremely low. Therefore, there has been a demand for the development of a drug that exhibits a high effect of preventing stains and the like with a small amount of use (low concentration). SUMMARY OF THE INVENTION In view of the above economy, the present invention keeps the surface of a dryer or a canvas always clean with a small amount of use, and prevents deterioration of paper quality and decrease in drying efficiency. For the purpose of improving productivity and significantly prolonging the durable use period of a canvas or a dryer, a silicone oil emulsion having a viscosity of 1000 cst (25 ° C.) or less (O / W type, silicone oil 30 to 65%) and a viscosity of at least 100,000 cst (25 ° C.) or a curable silicone oil emulsion (O / W type, silicone oil 20 to 40%) in a weight ratio of 9: 1 to 5: 5. Emulsion of the mixture (0 /
(W type) to which a fluorine-based surfactant is added in an amount of 0.01 to 5.0% by weight based on silicone oil. The antifouling agent for the papermaking dryer process of the present invention has a low concentration, especially 0.5% silicone oil.
It exerts its effects at the following concentrations and is diluted with water before use. That is, the antifouling agent as a stock solution usually has a total of 20 to 20 silicone oils in the mixture.
The proportion is adjusted to 50% by weight, an emulsifier of 0.5 to 5% by weight, a fluorine-based surfactant of 0.002 to 2.5% by weight, and the balance of water. [0008] Silicone oil is widely used as a release agent, but as a stain adhesion preventive for a papermaking dryer process, a low-viscosity silicone oil emulsion having a viscosity of 1000 cst (25 ° C) or less or a viscosity of 1 or less is used.
A useful effect cannot be obtained even when a high-viscosity or curable silicone oil emulsion having a viscosity of at least 10,000 cst (25 ° C.) is used alone. In addition, a useful effect cannot be obtained when a low-viscosity silicone oil and a high-viscosity or curable silicone oil are simultaneously emulsified. That is, a low viscosity product and a high viscosity product or a curable product of a silicone oil previously prepared as an emulsion (O / W type) are mixed and combined in a specific ratio as described in the present invention, and thus, the silicone oil is used for the paper making dryer process for the first time. The effect as an antifouling agent can be obtained. The effect of this combination is considered to be a synergistic effect between the anti-adhesive property of the low-viscosity product and the film forming ability of the high-viscosity product or the curable product due to the adhesive force and adhesion on the dryer or canvas surface. On the other hand, only low-viscosity products are easily adsorbed on paper due to their liquid properties, and hardly remain as a film on the dryer or canvas surface. Although a high-viscosity product alone has the ability to form a film, the film itself tends to adhere, rather than prevent the adherence of the stain, due to the adhesiveness and viscosity of the film itself. Further, the curable product alone has almost no adhesion preventing effect. Further, intermediate viscosity between the low viscosity product and the high viscosity product,
For example, a silicone oil emulsion having a viscosity of 5,000 to 50,000 cst (25 ° C.) alone is insufficient in both the antifouling effect and the film-forming ability. Further, when a low-viscosity silicone oil and a high-viscosity or curable silicone oil are simultaneously emulsified, the emulsion is simply an emulsion of an average-viscosity silicone oil mixture. No effect can be obtained. That is, as described above, the present invention is a mixture of a low-viscosity silicone oil emulsion and a high-viscosity or curable silicone oil emulsion which are separately emulsified (O / W type) in advance. Therefore, a plurality of types of emulsion fine particles exist in the mixture. When this mixture is sprayed onto the surface of a dryer or a canvas, a film is formed after the evaporation of water, but it is not a film in which a low-viscosity silicone oil and a high-viscosity or curable silicone oil are uniformly mixed, but a low-viscosity silicone oil. The oil and the high-viscosity or curable silicone oil are each layered to form a film. High viscosity or curable silicone oil easily adheres to the dryer or canvas surface, while low viscosity silicone oil is less likely to adhere to the surface. A small amount of low viscosity silicone oil is present in the silicone oil, and the opposite of the surface layer in the membrane. Therefore, a layer for preventing the adhesion of dirt is formed on the surface of the film, and a layer that adheres and adheres to the dryer or the canvas is also formed. Therefore, in practice, the low-viscosity silicone oil-based dirt adhesion preventing layer formed on the film surface transfers to the paper while preventing dirt such as paper dust and pitch from adhering to the paper. This layer contains a low-viscosity silicone oil having an anti-adhesion property to a high-viscosity or curable silicone oil, so that the effect of preventing the adhesion of dirt is maintained. [0011] As the silicone oil as described above,
Dimethyl polysiloxane oil, polyether modified silicone oil, carboxyl modified silicone oil,
Examples thereof include alcohol-modified silicone oils, epoxy-modified silicone oils, amino-modified silicone oils, methyl hydrogen polysiloxane-based oils, alkyl-aralkyl-polyether-modified silicone oils, and the like. Alternatively, it can be selected and used as a curable silicone oil. Generally, as the low-viscosity silicone oil and the high-viscosity silicone oil, a dimethylpolysiloxane-based oil is economically used. As the curable silicone oil, an amino-modified silicone oil, a carboxyl-modified silicone oil, or the like is used. The above silicone oil is used in an oil-in-water type (O /
Examples of the emulsifier to be emulsified in W) include nonionic polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol ethers, polyoxyethylene fatty acid esters, and the like. Oxyethylene alkyl phosphate ester salts, alkyl sulfosuccinic acids and the like are exemplified. In addition, amphoteric and cationic types can be appropriately used in combination for the purpose of the type of silicone oil and emulsion stability. As described above, the antifouling agent of the present invention comprises a mixture of the low-viscosity silicone oil emulsion and the high-viscosity or curable silicone oil emulsion in a weight ratio of 9: 1 to 5: 5. If the ratio is out of the above range, the performance is close to that of a single silicone oil, and a useful effect cannot be obtained. As described above, this combination can provide a more effective antifouling agent than the conventional oil-in-water (O / W) emulsion of an oily substance. Further, a fluorine-based surfactant is added to improve the performance. By adding this fluorine-based surfactant, the wettability to the dryer or the canvas surface is improved, a sufficient silicone oil film is formed, and the effect of preventing contamination is improved. The above-mentioned fluorine-containing surfactant is added in an amount of 0.01 to 5.0% by weight based on the silicone oil. Preferably it is 0.05 to 3.0% by weight. When the amount of the fluorine-based surfactant added to the silicone oil is 0.01% by weight or less, only the same effect of preventing contamination as in the case of no addition is obtained. Even when the amount is 5.0% by weight or more, remarkable performance is obtained. No improvement is seen, but it is rather disadvantageous from the economic point of view. still,
It is desirable that the amount of the fluorine-based surfactant is appropriately set within the above range depending on the concentration of the silicone oil used. Usually, when the concentration of the silicone oil is low, the amount of addition is large, and when the concentration is high, the addition amount may be small. As such a fluorine-based surfactant,
Although not particularly limited, nonionic perfluoroalkylethylene oxide adducts, anionic perfluoroalkylsulfonic acid, perfluoroalkylcarboxylates (K, Na, Li, NH ₃ etc. as salts), perfluoroalkyl Illustrative are amphoteric systems of alkyl betaines or cationic systems of perfluoroalkyl quaternary ammonium salts. In the present invention, anionic and nonionic are particularly effective. In order to improve only the wettability, a general hydrocarbon surfactant is also effective, but the effect of preventing the adhesion of the silicone oil of the present invention at an extremely low concentration was hardly observed. . For example, when the amount of the above-mentioned hydrocarbon-based surfactant is increased to be substantially the same as that of the silicone oil, the wettability is improved to some extent, but the original effect of preventing the film from being stained is lost. The method of attaching the diluted antifouling agent of the present invention composed of each component described above to a dryer or a canvas surface is not particularly limited, and any specific means may be used. Is also good. For example, in the dryer shown in FIG.
In general, an appropriate addition device is installed at the position indicated by, and the diluted antifouling agent is sprayed onto the canvas from the addition device. In FIG. 1, reference numeral 1 denotes a feed roller arranged in zigzag, and 2 denotes a short-diameter support roller, which is supported on an endless canvas 3 stretched between the feed roller 1 and the support roller 2. The paper 4 having a width of 4 to 5 m is dried in the folded state. As an addition device installed at the position indicated by A, there is, for example, an addition device having a configuration shown in FIG. In this addition device, a predetermined proportion of the stock drug solution (anti-fouling agent) 6 contained in the medicine tank 5 and a predetermined proportion of the water 8 contained in the fresh water tank 7 are mixed by the pumps 9 and 10, respectively. Then, the mixture is diluted in the mixing chamber 11, and uniformly mixed and emulsified. This is sent at regular intervals to the header 12 provided with nozzles,
This is a configuration in which the air is mixed with compressed air 13 that is separately supplied, and sprayed onto a canvas from a nozzle using the air pressure. However, when the antifouling agent is sprayed by the above-mentioned addition device, the antifouling agent is atomized by the compressed air, and only about 50% of the silicone oil adheres to the canvas, leaving about 50% of the remaining amount. %, Which floats in the air and adheres to parts other than the canvas, has a disadvantage that the addition loss is very large. On the other hand, if the addition device shown in FIG. 3 is used, the above-described addition loss can be reduced. In this addition device, a rotating shaft 14 rotatable by a motor (not shown) or the like is provided above the canvas 3.
Is formed in such a manner that a molded product 15 in which metal, plastic, or the like is wound in a coil shape is spirally wound around the peripheral surface. The antifouling agent diluted to a predetermined concentration is introduced into the liquid reservoir 16 via a supply path (not shown), and is applied to the rotating shaft 14 by its own weight through a plurality of drop holes 17 provided on the bottom surface of the liquid reservoir 16. Fall towards. The amount of drop can be adjusted by the diameter of the drop hole 17. Then, the dropped dirt adhesion preventing agent is applied to the rotating coiled product 15.
At the same time, the particles are scattered as fine droplets due to the centrifugal force and adhere to the surface of the canvas 3 uniformly. The use of the addition device having the above-described structure can reduce the addition loss of the antifouling agent to about 10%, and also reduces power consumption because compressed air is not used. The present invention will be described below with reference to examples. Example 1 SM7060 (manufactured by Toray Dow Corning Silicone Co., Ltd.) 55.0% by weight [Emulsion of dimethyl silicone oil 350 cst, active ingredient 62%] SM8701 (manufactured by Toray Dow Corning Silicone Co., Ltd.) 0% by weight [Emulsion of 1,000,000 cst dimethyl silicone oil, active ingredient 30%] Florad FC-98 (manufactured by Sumitomo 3M Limited) 0.2% by weight [potassium perfluoroalkyl sulfonate, anionic, fluorine] Water 24.8% by weight The antifouling agent of the above mixed emulsified (O / W type) composition was diluted 200 times with water (active ingredient ≒ 0.2% by weight), and the surface of the Yankee dryer in the liner paper manufacturing process ( Dryer width = 3m) with 12 spray nozzles and 0.8 liters per minute Was sprayed. Conventionally, the above-mentioned dryer has 12 spray nozzles obtained by diluting an oil-in-water (O / W) emulsion (active ingredient = 40%) containing spindle oil as a main component 100 times (oil substance = 0.4%). The spray was sprayed at a rate of 0.8 liters per minute, but the surface of the dryer was contaminated with pitch and paper dust, and rust was partially observed. In addition, the produced liner paper had intermittent adhesion and non-uniformity of pitch on the surface, and sometimes the paper was cut. Furthermore, cleaning was performed weekly, but both productivity and quality were poor. In contrast, the antifouling agent of Example 1 (200-fold dilution)
After about 2 to 3 hours after spraying, the gloss of the silicone film layer begins to appear on the dryer surface, and there is no dirt such as pitch, paper dust, rust, etc., and a uniform and high quality liner paper can be obtained. Became. In addition, we used continuously for one month afterwards, but there was no dirt on the dryer surface,
It is now possible to obtain liner paper with improved quality. Furthermore, there were no operational troubles such as running out of paper. Further, the improvement of the drying efficiency makes it possible to increase the paper making speed from 850 m / min to 920 m / min by about 8%,
Production efficiency improved. Example 2 TSM640 (manufactured by Toshiba Silicone Co., Ltd.) 30.0% by weight [Emulsion of dimethyl silicone oil 350 cst, active ingredient 30%] SM8702 (manufactured by Toray Dow Corning Silicone Co., Ltd.) 15.0% by weight % [Amino-modified silicone oil curable emulsion (formation of gum-like film), active ingredient 38%]-0.1% by weight of Megafac F-144D (manufactured by Dainippon Ink and Chemicals, Inc.) [Perfluoroalkylethylene oxide adduct , Nonionic, fluorine-based] ・ Water 54.9% by weight The antifouling agent of the above mixed emulsified (O / W type) composition was diluted 100-fold with water (active ingredient ≒ 0.15% by weight), and Multi-cylinder dryer canvas in the core manufacturing process (width = 4m)
Was spray-sprayed at a rate of 0.8 liter per minute. Conventionally, the above-mentioned canvas has not been subjected to any treatment, so that the drying efficiency and the paper quality deteriorate due to dirt such as paper dust and pitch, and the canvas is replaced in about three months. On the other hand, the antifouling agent (1
Spray spraying (100-fold dilution) onto a new canvas shows that almost no dirt such as paper dust and pitch is seen on the canvas after 3 months, and it is similar to the new one, and the drying efficiency is almost the same as at the start. Was maintained. <Example 3> TSM641 (manufactured by Toshiba Silicone Co., Ltd.) 60.00% by weight [Emulsion of dimethyl silicone oil 1000 cst, active ingredient 30%] SM8701 39.95% by weight Megafac F-144D 05% by weight The antifouling agent of the above mixed emulsified (O / W type) composition was diluted 200 times with water (active ingredient ≒ 0.15% by weight), and a canvas of a multi-cylinder dryer in the core manufacturing process ( (Width = 6m)
Were sprayed at 20 liters of spray nozzles at a rate of 1.0 liter per minute. Conventionally, the above-mentioned canvas has not been subjected to any treatment, so that the drying efficiency is poor due to adhesion of paper powder, pitch, etc., and the canvas has been replaced in about four months. On the other hand, when the antifouling agent of Example 3 (200-fold dilution) was sprayed onto a new canvas, very little dirt was seen on the canvas even after 4 months, and the drying efficiency was low at the start. It was maintained at about the same level. Example 4 TSM630 (manufactured by Toshiba Silicone Co., Ltd.) 30.0% by weight [Emulsion of dimethyl silicone oil 200 cst, active ingredient 37%] SH8710 (manufactured by Toray Dow Corning Silicone Co., Ltd.) 30.0% by weight % [Emulsion of dimethyl silicone oil 100,000 cst, active ingredient 38%] Neugen EA-140 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2.0% by weight [polyoxyethylene nonylphenol ether] Megafac F-150 (large 0.8% by weight [Perfluoroalkyltrimethylammonium chloride] ・ Water 37.2% by weight The antifouling agent of the above mixed emulsified (O / W type) composition was increased by 200 times with water. Diluted (active ingredient ≒ 0.1% by weight) Dropping hole 12 using an addition device of FIG 3 in drier canvas (width = 4m), the rotation speed 1000rpm of the rotary shaft, was added under the condition of min 1.0 liters. Conventionally, the above-mentioned canvas has not been subjected to any treatment, so that the drying efficiency and the paper quality deteriorate due to dirt such as paper dust and pitch, and the canvas is replaced in about three months.
On the other hand, when the antifouling agent of Example 4 (diluted 200-fold) was added to a new canvas using the adding device of FIG. 3, the soil such as paper dust and pitch was removed after 3 months. And the drying efficiency was almost the same as at the start. Further, the use of the addition device of FIG. 3 reduced the power consumption to about 70% of the conventional one. <Comparative Example 1> The following composition was used except that the fluorosurfactant (Fluorard FC-98) was removed from the composition of Example 1 described above. 57.0% by weight of SM7060 20.0% by weight of SM8701 25.0% by weight of water 25.0% by weight of the above mixed emulsified composition (O / W type) was diluted 200-fold in the same manner as in Example 1 (active ingredient ≒ 0. 2% by weight) and sprayed on the same dryer under the same conditions. Soil such as pitch and paper dust was not so noticeable for about one week, but about 2 weeks.
After a week, the adhesion of the pitch to the dryer and the paper dust became noticeable, and the peeling of the liner paper surface sometimes occurred. Further, when the spraying was continued, the soil became worse and paper breakage occurred. In the end, they had to be cleaned in about three weeks. Comparative Example 2 A low-viscosity silicone oil emulsion (TSM640) was prepared from the composition of Example 2 above.
The following compositions except for were used. -SM8702 40.0% by weight-Megafac F-144D 0.1% by weight-Water 59.9% by weight The emulsified composition was diluted 100 times as in Example 2 (active ingredient 0.15%). % By weight) and sprayed onto a new canvas. For about one week, almost no stain such as paper dust was visible, but after about three weeks, spots of paper dust and partial adhesion of pitch began to appear on the canvas surface.
After about one and a half months, paper dust and pitch stains on the canvas were noticeable, and pitch stains also intermittently adhered to the paper surface. Further, the drying efficiency is reduced, and the paper making speed is 850 m /
It had to be reduced by about 6% from min to 800 m / min. After four and a half months, the canvas was replaced. Comparative Example 3 A curable silicone oil emulsion (SM8702) was prepared from the composition of Example 2 above.
The following compositions except for were used. -TSM640 50.0% by weight-Megafac F-144D 0.1% by weight-Water 49.9% by weight The emulsified composition (O / W type) was prepared in the same manner as in Example 2 above.
However, it is diluted 100 times (active ingredient 0.15% by weight)
A new canvas was sprayed. The result was slightly worse than that of Comparative Example 2, and the canvas was eventually replaced in about 4 months. <Comparative Example 4> 50.0% by weight of TSM642 (manufactured by Toshiba Silicone Co., Ltd., 30% active ingredient) [emulsion of 10000 cst dimethyl silicone oil] 0.1% by weight of Florad FC-98 0.1% water 49. 9% by weight The emulsified composition (O / W type) was prepared in the same manner as in Example 3 above.
However, it is diluted 100 times (active ingredient 0.15% by weight)
A new canvas was sprayed. The result was that the canvas was less contaminated than when no treatment was performed, but the drying efficiency was also reduced, and the replacement period of the canvas was increased by only about one month. Comparative Example 5 No. 1 spindle oil 2 (Nippon Oil Co., Ltd.) 50.0% by weight Neugen ES129 (Daiichi Kogyo Seiyaku Co., Ltd.) 5.0% by weight [Polyethylene glycol oleate, Nonionic type] Water 45.0% by weight The emulsified composition (O / W type) was prepared in the same manner as in Example 3 above.
It was diluted 200 times with water (active ingredient ≒ 0.3% by weight) and sprayed onto a new canvas. The result was the same as when no treatment was performed, and almost no effect was observed.
The canvas was replaced in about four months. Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and may be implemented in any way unless the configuration described in the claims is changed. Can be. As described above, when the antifouling agent of the present invention is applied to the papermaking drier process, it prevents paper dust and pitch from adhering and keeps the canvas and the drier clean for a long time. Thus, high quality paper can be stably obtained without causing poor drying or the like. Even when the silicone oil is diluted to a low concentration such that the emulsion contains only about 0.5% or less of the silicone oil, an effect of preventing adhesion of dirt to a surface of a canvas, a drier or the like is imparted. be able to. That is,
It exhibits a high effect of preventing adhesion of dirt with a very small amount of use as compared with the related art, and is excellent in economic efficiency. Further, as described above, by keeping the canvas and dryer etc. clean for a long period of time, frequent replacement of the canvas is not required, and the drying efficiency is improved, so that the speed of paper making is increased and the productivity is increased. It can be improved, and together with the above-mentioned effects, the economic effect becomes extremely high as compared with the related art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view schematically showing an example of a paper making dryer process. FIG. 2 is a view conceptually showing a configuration of an example of a device for adding a stain adhesion preventing agent. FIG. 3 is a front view conceptually showing another example of a device for adding a stain adhesion preventing agent.

Claims (1)

(57) [Claim 1] A silicone oil emulsion (O / W type, silicone oil 30-65%) having a viscosity of 1000 cst (25 ° C.) or less and a viscosity of 100,000 cst (25 ° C.)
Or an emulsion (O / W type) in which the weight ratio with a curable silicone oil emulsion (O / W type, silicone oil 20 to 40%) is 9: 1 to 5: 5.
(W type), wherein a fluorine-based surfactant is added in an amount of 0.01 to 5.0% by weight based on silicone oil.