JP2008285782A - Method for producing crepe paper and coating agent for producing crepe paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing crepe paper, excellent in productivity and capable of producing the high quality crepe paper stably, and a crepe assistant capable of being used in the method. <P>SOLUTION: In the method for producing the crepe paper by attaching a coating agent containing an adhesive component consisting of a polymer on the surface of a rotating cylindrical Yankee drier 10 to attach web 15 on the Yankee drier, and then forming the crepe by peeling off the web 15 by making a doctor blade 93 abut on the Yankee drier 10, a water soluble polyamide resin and phosphoric acid salt are contained in the coating agent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing crepe paper capable of performing stable creping and a coating agent for producing crepe paper used therein.

  Conventionally, toilet paper and tissue paper have been subjected to creping which is processed into a crepe-like shape in order to provide water absorption, oil absorption, touch and softness. This creping process is manufactured by a crepe paper manufacturing apparatus 100 as shown in FIG. The crepe paper manufacturing apparatus 100 includes a rotating cylindrical Yankee dryer 90 and a coating agent spray nozzle 91 for spraying a coating agent onto the surface of the Yankee dryer 90. The damp web 92 supplied from the paper making line 101 is adhered by the coating agent adhering to the surface of the Yankee dryer 90 and rotates while being dried by heat transfer from the Yankee dryer 90. Then, when the adhered web 92 is peeled off by the doctor blade 93 brought into contact with the Yankee dryer 90, creping (that is, wrinkles in the form of dust) is instantaneously performed. The creped paper web 92 is wound up to become a crepe paper 94.

Creping mechanically compresses the paper in the machine direction and increases the basis weight (mass per unit area) to dramatically change the physical properties in the machine direction. Crepe processing is generally performed by a coating agent (or adhesive for creping) that improves the adhesion between the surface of the paper and the Yankee dryer, and a flexible blade doctor blade that peels the paper from the surface of the Yankee dryer. Is also used in the final stage of the Yankee dryer. Crepeability depends on the balance between the adhesion of the paper to the Yankee dryer surface and the peelability by the doctor blade. Excessive strong adhesion prevents peeling, leading to paper breakage, and weak adhesion is sufficient for creping. Cannot be obtained. Accordingly, various methods have been proposed in consideration of the compatibility. For example, a crepe paper is produced by placing a doctor on a wet part press roll and forming a crepe with a sheet moisture of 60 to 75% by weight, with a free run distance of 5 to 60 cm and a wet elongation of 10 to 35%. The use of a creping aid comprising the reaction product of a dicarboxylic acid or an ester of an aliphatic dicarboxylic acid with a polyamide of methylbis (3-aminopropylamine) and epichlorohydrin ( For example, see Patent Document 2), a creping method by two-step deposition of a creping adhesive containing polyvinyl alcohol as a creping adhesive and a creping adhesive containing a water-soluble thermosetting cationic polyamide resin (for example, patent) In order to increase the productivity and quality of the crepe paper manufacturing equipment, see Yankee Dry On the surface of depositing a solid lubricant it has been proposed (Patent Document 4). The solid lubricant fills and smoothes the unevenness generated on the surface of the Yankee dryer. In addition, the solid lubricant reduces the frictional force between the doctor blade and the Yankee dryer and improves sliding. For this reason, the state of the crepe paper is constantly constant, and high-quality crepe paper with fine wrinkles can be supplied stably. In addition, there is a method of using cationic starch, polyvinyl alcohol and a water-soluble thermosetting cationic polyamide epihalohydrin resin as the creping adhesive (for example, see Patent Documents 5 and 6).
JP-A-5-239789 JP-A-6-49796 Japanese National Patent Publication No. 11-514049 JP 2001-64897 A Special table 2001-511224 gazette Special Table 2002-506937

  The crepe state of the crepe paper manufactured by the conventional crepe paper manufacturing apparatus as shown in FIG. 2 includes the adhesive force between the paper web 92 and the Yankee dryer 90 by the coating agent, the moisture content of the paper web 92, and the like. Affected by many factors. For example, when the web 92 is strongly adhered to the Yankee dryer 90, the crepe produced by the peeling by the doctor blade 93 becomes fine, or the peeling has failed and the web 92 sinks under the doctor blade 93. This will cause the paper to break and hinder operations. On the contrary, when the adhesive force between the web 92 and the Yankee dryer 90 is weak, a rough crepe is formed.

  For this reason, in order to stably manufacture the crepe paper having wrinkles with the optimal roughness, it is necessary to keep the adhesive strength of the web 92 to the Yankee dryer 90 constantly. However, since the adhesive strength between the paper web 92 and the Yankee dryer 90 changes not only according to the composition of the coating agent, but also depending on the moisture content of the paper web 92 and the state of dirt and corrosion on the surface of the Yankee dryer 90, the paper web 92. It has been difficult to keep the adhesive strength of the Yankee dryer 90 constant, and there has been a problem that the quality is not stable and the defect rate is high. If the rotational speed of the Yankee dryer 90 is slowed, the defective rate is reduced, but the productivity is lowered.

  The present invention has been made in view of the above-described conventional circumstances, and provides a method for producing crepe paper that is excellent in productivity and can stably produce high-quality crepe paper, and a coating agent that can be used therefor. This is a problem to be solved.

  As a result of diligent research to solve the above-described conventional problems, the inventors of the present invention have a constant crepe state if a coating agent containing an adhesive component made of a polymer further contains phosphate. Was found, and it was found that high-quality crepe paper could be stably produced, and the present invention was made.

  That is, in the method for producing a crepe paper of the present invention, after a paper base is attached to the Yankee dryer by attaching a coating agent containing an adhesive component made of a polymer to the surface of a rotating cylindrical Yankee dryer, In the crepe paper manufacturing method of forming a crepe by bringing a doctor blade into contact with the Yankee dryer and peeling off the paper web, the coating agent contains a water-soluble polyamide resin and a phosphate. And

  The role of phosphate in the present invention is not necessarily clear, but is considered as follows. That is, (1) The dispersion state of the adhesive component composed of the polymer contained in the coating agent is stabilized by the pH buffering action of the phosphate. In particular, when the adhesive component has an amino group, generation of unstable free amine is suppressed, which is effective. (2) An iron phosphate film is formed by the action of phosphate on the surface of a Yankee dryer made of iron such as cast iron, and the corrosion protection effect of the iron phosphate film results in the formation of corrosives on the surface of the Yankee dryer. It is suppressed and it becomes difficult for foreign matter to adhere. (3) The calcium ions in the water are chelated by the phosphate, and adhesion of scale to the Yankee dryer is prevented.

  Moreover, according to the test results of the inventors, the crepe state of the crepe paper can be easily adjusted by adjusting the ratio of the adhesive component and the phosphate contained in the coating agent. The content ratio of the phosphate is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the adhesive component. When the phosphate content is within this range, high-quality crepe paper can be stably produced.

  As described above, in the method for producing crepe paper of the present invention, an aqueous solution containing a water-soluble polyamide resin and a phosphate can be used as a coating agent for producing crepe paper.

  Examples of the water-soluble polyamide resin include a polyamide-epihalohydrin resin, a glyoxalated polyacrylamide resin, and the like, and a polyamide-epihalohydrin resin is particularly preferable. The polyamide-epihalohydrin resin is a partially crosslinked water-soluble polyamide-epihalohydrin obtained by reacting a polyamide polycondensate, which is a condensate of a dicarboxylic acid and a polyalkylene polyamine, with an epihalohydrin (epichlorohydrin, epibromohydrin, etc.). Resin. The composition ratio of the dicarboxylic acid and the polyalkylene polyamine in the polyamide polycondensate is 0.7 to 1.5 equivalents, preferably 0.8, based on 1 equivalent of the primary amino group (terminal amino group) of the polyalkylene polyamine. -1.3 equivalents. Dicarboxylic acids include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid and sebacic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; these aliphatic dicarboxylic acids and aromatic dicarboxylic acids Dicarboxylic acid ester diethyl malonate, dimethyl adipate, dimethyl terephthalate; dicarboxylic anhydride succinic anhydride, glutaric anhydride, phthalic anhydride; dicarboxylic acid halide adipic acid chloride, etc. Can be mentioned. Two or more different dicarboxylic acids may be mixed and used. Of these, aliphatic dicarboxylic acids having 3 to 10 carbon atoms are preferred, and adipic acid is preferred. Examples of the polyalkylene polyamine include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, 3-azahexane-1,6-diamine, 4,7-diazadecane-1,10-diamine, and the like. Two or more different polyalkylene polyamines may be mixed and used as the polyalkylene polyamine. Of the polyalkylene polyamines, diethylenetriamine and triethylenetetramine are preferred.

  A water-soluble polyamide-epihalohydrin resin can be obtained by a partial crosslinking reaction between the polyamide polycondensate and the epihalohydrin. Since the properties of the polyamide-epichlorohydrin resin can be easily controlled by the epihalohydrin cross-linking agent, a crepe paper having the intended quality can be produced. Epihalohydrin includes epichlorohydrin and epibromohydrin, preferably epichlorohydrin. The amount of epichlorohydrin used is usually 0.7 to 1.5 equivalents, preferably 0.8 to 1.1, with respect to 1 equivalent of the secondary amino group (intramolecular amino group) in the polyamide polycondensate. 3 equivalents. When epichlorohydrin is less than 0.7 equivalent, the adhesive strength of the polyamide polycondensate may be lowered. Moreover, when it exceeds 1.5 equivalent, the water-soluble fall of polyamide-epichlorohydrin resin and content of a low molecular organic halogen compound may increase.

  A preferable property of the polyamide-epichlorohydrin resin is that the viscosity at 20 ° C. in a 25 wt% aqueous solution is in the range of 50 to 300 mPa · s, more preferably 70 to 250 mPa · s. When the viscosity is less than 50 mPa · s, the adhesion of the web to the surface of the Yankee dryer is low. On the other hand, if it exceeds 300 mPa · s, the workability and foamability when using the resin are increased.

  The gloxalated polyacrylamide resin can be obtained by reacting polyacrylamide with glyoxal to obtain a partially crosslinked product of polyacrylamide, or reacting polyacrylamide with glycidyldimethylammonium chloride to obtain a partially crosslinked product of polyacrylamide. The molecular weight of polyacrylamide is 1,000 to 3,000,000. If the molecular weight of the polyacrylamide is less than 1,000, the adhesive force of the present invention may not be sufficiently exerted. If the molecular weight of the polyacrylamide exceeds 3,000,000, the viscosity is high and the handleability is lowered, and the cohesiveness is further increased. Also become stronger. The ratio of both when polyacrylamide is reacted with glyoxal or glycidyldimethylammonium chloride may be appropriately determined in consideration of the target degree of water solubility, but usually 0.7 to 1. 5. Examples of the gloxalated polyacrylamide resin include a commercially available “Hercobond (trade name)”.

  In addition to the water-soluble polyamide resin, polyvinyl alcohol, polyvinyl acetate, cationized carboxymethylcellulose resin, cationized starch, and polyethyleneimine, which are conventionally used polymer-based adhesive components, as long as the effects of the present invention are not hindered Resin, urea formaldehyde resin, and melamine formaldehyde resin can be used in combination.

  As the phosphate contained in the coating agent, monoammonium phosphate and diammonium phosphate are preferably used alone or in combination. An aqueous solution of monoammonium phosphate becomes acidic to weakly acidic, and an aqueous solution of diammonium phosphate becomes weakly alkaline. This is because by using these alone or in combination, a pH range in which the amino group present in the water-soluble polyamide resin stably exists as an ammonium salt can be obtained.

  The adjustment method of a coating agent is not specifically limited, What is necessary is just to carry out according to the general water-soluble resin and the method of melt | dissolving a phosphate in water. Specifically, the water-soluble polyamide resin is dissolved in water while stirring at room temperature to obtain an aqueous solution, and mono-ammonium phosphate and diammonium phosphate are added singly or in combination, and the pH is 3 to 7, Preferably, the pH is set to 3.5 to 6.5 to obtain a uniform solution. The concentration of the water-soluble polyamide resin may be appropriately determined in consideration of the paper quality of the stock to be applied, the situation of the Yankee dryer, and the required creping performance, and is usually 10 to 50% by weight. In addition, the amount of the phosphate may be appropriately determined in consideration of the type of water-soluble polyamide resin to be used, the paper quality of the paper to be applied and the situation of the Yankee dryer, and the required creping performance. It mix | blends in 0.1-50 weight part with respect to 100 weight part of polyamide resins, Preferably it is 1-20 weight part. If the phosphate is less than 0.1 part by weight, the peeling effect of the present invention may not be exhibited. On the other hand, when the amount of phosphate exceeds 50 parts by weight, there is no economic merit because an effect sufficient to meet the increase in the amount of phosphate added cannot be obtained. Although the density | concentration of the phosphate in a coating agent is not specifically limited, Usually, 1-30 weight% is mix | blended.

The coating agent is usually used by spraying on the surface of the Yankee dryer. The amount of spraying may be appropriately determined in consideration of the conditions of the paper material to be applied and the state of the Yankee dryer, the type of water-soluble polyamide resin to be used, the required creping performance and the combined use of a release agent, The water-soluble polyamide resin as an active ingredient of the coating agent is 0.01 mg to 20 mg per 1 m ² area of the Yankee dryer surface.
Spraying of the coating agent on the surface of the Yankee dryer is performed using a normal chemical injection pump and a spray nozzle.

  Hereinafter, examples embodying the present invention will be described in detail in comparison with comparative examples.

<Preparation of coating agent>
Example 1
In Example 1, epichlorohydrin crosslinked polyamide resin (diethylenetriamine: adipic acid: epichlorohydrin = 1: 1: 1 (molar ratio), viscosity of 25% by weight aqueous solution is 120 mPa · s) 10% by weight aqueous solution 100 100 parts by weight of a 0.5% by weight aqueous solution of monoammonium phosphate with respect to parts by weight was added and mixed to form a coating agent stock solution. Further, this coating agent stock solution was diluted 1000 times to obtain a coating agent. Epichlorohydrin cross-linked polyamide resin is a water-soluble polyamide resin.

(Example 2)
In Example 2, epichlorohydrin crosslinked polyamide resin (diethylenetriamine: adipic acid: epichlorohydrin = 1: 1: 1 (molar ratio), viscosity of 25% by weight aqueous solution is 120 mPa · s) 10% by weight aqueous solution 100 50 parts by weight of a 0.5% by weight aqueous solution of monoammonium phosphate was added to and mixed with parts by weight to prepare a coating solution stock solution. Other conditions are the same as those in the first embodiment, and a description thereof will be omitted.

(Example 3)
In Example 3, epichlorohydrin cross-linked polyamide resin (diethylenetriamine: adipic acid: epichlorohydrin = 1: 1: 1 (molar ratio), viscosity of 25 wt% aqueous solution is 120 mPa · s) 10 wt% aqueous solution 100 10 parts by weight of an aqueous solution of 0.5% by weight of ammonium monophosphate was added to and mixed with parts by weight to obtain a coating solution stock solution. Other conditions are the same as those in the first embodiment, and a description thereof will be omitted.

(Comparative Example 1)
In Comparative Example 1, an epichlorohydrin-crosslinked polyamide-based resin (diethylenetriamine: adipic acid: epichlorohydrin = 1: 1: 1 (molar ratio), the viscosity of a 25 wt% aqueous solution was 120 mPa · s) was added to a 10 wt% aqueous solution. What was diluted 1000 times without adding monoammonium phosphate was used as a coating agent.

  Using the crepe paper production coating agents of Examples 1 to 3 and Comparative Example 1 prepared as described above, crepe paper was produced using the crepe paper production apparatus 1 shown in FIG. The crepe paper manufacturing apparatus 1 is configured to spray a rotating cylindrical cast iron Yankee dryer 10 (width 6 m), a coating agent spray nozzle 11 for spraying a coating agent on the surface of the Yankee dryer 10, and a release agent. The release agent spray nozzle 12 is provided. On the upstream side of the coating agent spray nozzle 11 and the release agent spray nozzle 12 in the rotational direction of the Yankee dryer 10, a doctor blade 14 for peeling the paper web 13 is fixed so as to contact the surface of the Yankee dryer 10. Yes.

  In the crepe paper manufacturing apparatus 1 configured as described above, the coating agent is sprayed from the coating agent spray nozzle 11 and adheres to the Yankee dryer 10. The release agent spray nozzle 12 sprays the release agent and adheres to the Yankee dryer 10. After the coating agent and the release agent are attached to the Yankee dryer 10 in this way, a damp web 13 is supplied from the paper making line 15 and wound around the surface of the Yankee dryer 10. The web 13 is attached to the Yankee dryer 10 by the coating agent, and rotates while being dried by heat transfer from the Yankee dryer 10. The adhering web 13 is instantaneously creped when it is peeled off by the doctor blade 14 in contact with the Yankee dryer 10. In this way, the web 13 is creped to become a crepe paper 17 and wound around the drum 16.

<Toilet paper manufacturing test>
A toilet paper production test was performed using the crepe paper production apparatus 1 under the following production conditions.
・ Toilet paper basis weight: 19.6 g / m ² , paper width: 6 m, paper making speed: 1,000 m / min ・ Yankee dryer entrance wet paper moisture: 50%
・ Coating agent: Epichlorohydrin cross-linked polyamide polyamine (trade name: Polyfix 301A Showa High Polymer) 10 weight concentration and mono-ammonium phosphate mixed aqueous solution ・ Coating agent spray amount: 2 mg / yankee dryer unit surface area (as effective solid content) (M ² )
-Release agent (10% by weight emulsified dispersion of paraffinic mineral oil): Spray amount: 0.5 mg / Yankee dryer unit surface area (m ² )

The coating agent is continuously sprayed onto the surface of the Yankee dryer 10 by using the coating agent spray nozzle 11 using a chemical injection pump (not shown), and the surface state of the Yankee dryer 10 after 24 hours, the generation state of paper dust, and the state of the crepe are checked. Visual evaluation was performed as follows.
(Evaluation of surface condition of Yankee dryer)
-○: There is gloss on the metal surface and there is no dirt.
-X: The metal surface is not glossy and the metal surface is contaminated.
(Evaluation of paper dust generation)
-○: There is little paper dust.
*: There is much paper dust.
(Evaluation of crepe condition)
-○: Sufficient creping has been obtained.
*: The crepe is defective.
Continuous spraying of the coating agent was continued and the blade replacement time was measured. The longer the blade replacement time, the better. Further, the rotational speed of the Yankee dryer 10 was gradually increased, and the maximum paper making speed at which normal crepe paper could be produced was also measured. The results are shown in Table 1.

<Result>
As a result of the above crepe paper production test, in Examples 1 to 3 using the coating agent added with monoammonium phosphate as shown in Table 1, in Comparative Example 1 using the coating agent without adding monoammonium phosphate. In comparison, the surface condition of the Yankee dryer was good, there was little occurrence of deposits and paper dust, and the time until the doctor blade had to be replaced became longer. In addition, as for the maximum papermaking speed, Comparative Example 1 is the slowest, and as the amount of monoammonium phosphate added increases, the time until the doctor blade is replaced becomes longer, and by adding monoammonium phosphate to the coating agent, The life of the doctor blade has also been extended.

-Curing test of coating agent-
In order to examine the curing performance of the coating agent, the following test was conducted. That is, epichlorohydrin cross-linked polyamide resin (diethylenetriamine: adipic acid: epichlorohydrin = 1: 1: 1 (molar ratio), viscosity of 25% by weight aqueous solution is 120 mPa · s) and 10% by weight of 100% by weight aqueous solution. On the other hand, a predetermined part by weight of a 15% by weight aqueous solution of monoammonium phosphate is added and mixed to form a coating agent stock solution, and this coating agent stock solution is further diluted 1000 times to obtain a coating agent. Then, 1 ml of this coating agent was applied on a stainless steel plate heated to 110 ° C. so as to be about 10 cm ^2, and a pencil hardness test was conducted after 10 minutes of curing. Further, the coating agent was scooped with a glass rod in the middle of heating, and the time until the yarn was not drawn was determined as the curing time.

  As a result, as shown in Table 2, it was found that the addition amount of monoammonium phosphate was increased, the curing time was increased, and the hardness was decreased. From this result, it can be seen that by increasing or decreasing the amount of monoammonium phosphate added to the coating agent, the curing time and hardness of the coating agent can be adjusted, and thus the crepe state of the crepe paper can be easily controlled. It was.

  The present invention is not limited to the description of the embodiments of the invention. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.

  The present invention can be suitably used for producing crepe paper such as toilet paper and tissue paper.

It is a schematic diagram of the crepe paper manufacturing apparatus used in the Example and the comparative example. It is a schematic diagram of a crepe paper manufacturing apparatus.

Claims (8)

A coating agent containing an adhesive component made of a polymer is attached to the surface of a rotating cylindrical Yankee dryer, and then a web is attached to the Yankee dryer, and then a doctor blade is brought into contact with the Yankee dryer to In a crepe paper manufacturing method for forming a crepe by peeling a paper web,
A method for producing a crepe paper, wherein the coating agent contains a water-soluble polyamide resin and a phosphate.   The method for producing a crepe paper according to claim 1, wherein a content ratio of the phosphate is 1 to 20 parts by weight with respect to 100 parts by weight of the adhesive component.   The method for producing a crepe paper according to claim 1 or 2, wherein the water-soluble polyamide resin is a polyamide-epihalohydrin resin.   The method for producing crepe paper according to claim 3, wherein the coating agent contains monoammonium phosphate and / or diammonium phosphate as a phosphate.   A coating agent for producing crepe paper, comprising water-soluble polyamide resin and phosphate as active ingredients.   6. The coating agent for producing crepe paper according to claim 5, wherein the water-soluble polyamide resin is a polyamide-epihalohydrin resin.   The coating agent for producing crepe paper according to claim 6, wherein the content ratio of the phosphate is 1 to 20 parts by weight with respect to 100 parts by weight of the polyamide-epihalohydrin resin.   The coating agent for producing crepe paper according to any one of claims 5 to 7, wherein the phosphate is monoammonium phosphate and / or diammonium phosphate.

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