JPH10212682A - Drier canvas for making paper and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject canvas capable of retaining an antistaining effect for preventing adhesion of gummy pitches or other stains to paper in a paper-making process over a long period by coating a drier canvas with the mixture of the first resin having water and oil-repelling properties with the second resin having hydroxyl groups. SOLUTION: This drier canvas is obtained by coating a drier canvas with the mixture of (A) a water and oil-repelling resin (e.g. a resin produced by mixing a perfluoroalkylethyl acrylate with a vinyl alcohol, dipropylene glycol methyl ether and water) with a hydroxyl group-having resin (e.g. a resin produced by mixing a perfluoroalkylethyl acrylate with polyethylene glycol, isopropyl alcohol and water). Even when a stain is adhered to the canvas, the stain can easily be washed out with water, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a papermaking dryer canvas for use in a dryer part of a papermaking machine, in particular, with improved antifouling properties, and a method for producing the same.

[0002]

2. Description of the Related Art In a dryer part of a paper machine in a paper making process, a gum-like pitch of an adhesive oil contained in a raw material of paper powder, or a size liquid or a coating liquid as a paste for papermaking becomes dirty and becomes a dryer. Accumulate on the surface of the canvas.
Therefore, it is preferable to apply some antifouling treatment to the dryer canvas.

Various methods have conventionally been proposed for improving the antifouling property. One of the methods is to apply a resin to the surface of a canvas to cope with the problem. This method is to prevent stains from adhering to the surface of the canvas by applying a resin. A canvas of a fabric, and a needle canvas (a fabric or the like is used as a base fabric, and a fiber web layer is laminated on both sides or one side of the base fabric) ) Can be applied to both.

This method (resin processing method) is further roughly classified into the following two methods.

[0005] (1) The first method is called water repelling or oil repelling, in which the surface of the canvas is coated with water repellent or oil repellent to wet the surface of the canvas with water or oil. And water-based or oil-based dirt to repel the dirt. As a specific example, for example, JP-A-57-171790 discloses a method of coating a surface of a papermaking cloth with a mixture of at least two kinds of resins among three kinds of resins such as a fluororesin, a silicone resin and an epoxy resin. It has been disclosed.

(2) The second method is called hydrophilic processing. By applying a hydrophilic resin to the surface of a canvas, the surface of the canvas is easily wetted with water or oil, and the aqueous or oil-based surface is used. Even if dirt adheres, the dirt is easily removed. As a specific example, for example, Japanese Patent Publication No. 57-5
No. 8474 discloses a method of providing a cured antifouling coating of a sulfonated or sulfated formalin-based resin on the surface of a papermaking net.

[0007]

However, in recent years, as a large amount of waste paper has been used as a raw material for papermaking, sticky substances such as natural rubber and synthetic rubber contained in the waste paper adhere to the dryer canvas. That phenomenon is a problem. Therefore, anti-fouling measures tend to be more stringent than before.

[0008] Under such circumstances, the repellent or oil repellent processing of (1) and the hydrophilizing processing of (2) had respective effects. However, depending on the application, these methods are not sufficient. Has become difficult. For this reason, various studies have been made to improve the resin used in the methods (1) and (2) to have a more antifouling property. However, in reality, a resin which can sufficiently cope with the problem cannot be found.

On the other hand, in the above-mentioned resin processing method, it is not necessary to use a special yarn material or a canvas structure for the canvas, and after weaving the dryer canvas or laminating the fiber web layer, the needling is performed. There is an advantage that antifouling treatment can be performed after the treatment. In other words, it is extremely difficult to change the yarn material and structure of each yarn for each product type according to each use, and it is practically impossible to perform the process. There is no such defect, and there is an advantage that antifouling measures can be easily taken.

Therefore, an object of the present invention is to improve the antifouling property of a dryer canvas without impairing the advantages of such a resin processing method.

[0011]

According to the present invention, the above (1)
It is considered that a resin having both functions of (1) and (2), that is, a resin having both functions of water repellency, oil repellency, and hydrophilicity can solve the problem. And the second resin were mixed, and various confirmation tests were performed.

The first resin is a water-repellent and oil-repellent resin, and is composed of a perfluoroalkylethyl acrylate (water repellent,
Oil effect) Alkyl acrylate (water effect, flexibility) Vinyl alcohol (processability) Dipropylene glycol methyl ether (solvent) A mixture of water.

[0013] The second resin is a water-repellent or oil-repellent resin and a tree having a hydrophilic group.
Oil effect) Polyethylene glycol (hydrophilic) Isopropyl alcohol (solvent) Water is mixed.

Various confirmation tests were carried out using a mixture of the first resin and the second resin (each 5% in weight ratio) and water (90% in weight ratio). The result was obtained.

This is because while using the dryer canvas,
Since the canvas is in contact with the air, the repellent water and oil base contained in the first resin are arranged on the surface of the canvas, so that the water and oil contained in the wet paper are repelled to prevent these dirt from adhering to the canvas. Even when the canvas is soiled, when the canvas is washed with water or the like, the turbid water and turbid oil groups are hidden inside the canvas, and the hydrophilic group of the second resin is coated on the canvas surface. It is considered that dirt is easily removed at the time of washing because the surface is covered with the surface.

The second resin has not only hydrophilic properties but also water repellency and oil repellency, so that the repellency and oil repellency of the first resin can be further improved. is there. Therefore, it is of course effective if the second resin has only a hydrophilic group.

As a result of the experiment, the mixing ratio of the first resin, the second resin, and water was 1-5: 1 to 5: 90-9.
8 (% by weight), more preferably 2.5
-5: 2.5-5: 90-95 (% by weight). In this case, it was also found that it is most desirable to make the mixing ratio (% by weight) of the first resin and the second resin the same.

Based on the above points, the present invention has the following configuration.

A mixture of a first resin having water repellency and oil repellency and a second resin having a hydrophilic group was applied to a canvas (claim 1). Here, "having repellent and oleaginous properties" means having repellent and oleaginous groups (the same applies to the following).

A mixture of a first resin having water repellency and oil repellency and a second resin having a water repellent and oil repellency and a hydrophilic group added thereto is applied (claim 2).

As the first resin, a resin obtained by mixing or copolymerizing a perfluoroalkylethyl acrylate-based copolymer and a copolymer of another acrylate double bond-containing monomer (eg, alkyl acrylate) is used. (Claim 3). In addition, "methacrylic acid" is also included in "acrylic ester" here.

As the second resin, a resin obtained by mixing or copolymerizing a perfluoroalkylethyl acrylate copolymer and an acrylate copolymer containing a polyalkylene glycol moiety (eg, polyethylene glycol) is used. 4). The “acrylate” here includes methacrylate.

A mixture of the first and second resins described in any of (1) to (3) and water is applied from one or both of the paper contact surface side and the back surface side of the canvas, thereby obtaining both The resin impregnation amount was large on the application surface side, and was gradually reduced toward the opposite side (claim 5).

In the above-mentioned papermaking dryer canvas, a mixture of the first and second resins described in the above and water is applied from one or both of the paper contact surface side and the back surface side of the canvas. (Claim 6).

At this time, the mixing ratio of the first resin, the second resin, and water is 1-5: 1-5: 90-98 (% by weight).

The papermaking dryer canvas of the present invention includes not only a textile dryer canvas but also a fabric dryer canvas.
It shall include a needle canvas having a woven fabric as a base cloth and needling a web on one or both sides of the base cloth.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a sectional view in which the present invention is applied to a needle canvas (1). The base fabric (11) of the needle canvas (1) is composed of a warp (21) and a surface weft (3
1) Using a polyester monofilament having a diameter of 0.4 mm as the back weft (33) and using four twisted acrylic spun yarns as the middle weft (32), a warp density of 84.5 /2.54 cm and a weft density of 15.5 × 3 / 2.54 cm.

A mixed web layer (10) formed by mixing a polyester fiber web and a nylon fiber web at a weight ratio of 70:30 on the paper contact side (PS side) of the base fabric (11) is 125 g / m2. Laminate with a weight of ²
Needle punching was performed together with 1) to obtain a needle canvas (1) having an integrated structure. The specifications of the obtained needle canvas 1 are as shown in FIG.

Further, the web layer 10 has a paper contact side (PS
Side), the resin content obtained by mixing the first resin, the second resin, and water described below is penetrated into the back side (BS side) while maintaining the speed of the kissing roll at 30 m / min. After drying, a drying treatment was performed.

The first resin has water repellency and oil repellency, for example, purple fluoroalkyl ethyl acrylate (water repellency, oil repellency) Alkyl acrylate (water repellency, flexibility) Vinyl alcohol (processability) A mixture of a solvent (dipropylene glycol monomethyl ether) and water (trade name: Asahigard AG-930,
Asahi Glass Co., Ltd.) is used.

The second resin is a resin having a water-repellent and oil-repellent property provided with a hydrophilic group. For example, a perfluoroalkylethyl acrylate (water repellent, oil-repellent effect) polyethylene glycol (hydrophilic) solvent A mixture of (isopropyl alcohol) and water (trade name: GS-1, manufactured by Asahi Glass Co., Ltd.) is used.

The above-mentioned resin-containing material is composed of the first and second resins.
Is produced by mixing the resin of formula (1) with water. At this time, the mixing ratio of the first and second resin agents was 5% by weight,
Water is 90% by weight.

[Embodiment 2] FIG. 3 is a cross-sectional view in which the present invention is applied to a fabric dryer canvas (40). In the dryer canvas (40), the warp (51) has a short side of 0.
A polyester monofilament having a flat section of 58 mm and a long side of 0.88 mm and having a flat cross section, and woven using a 0.8 mm diameter polyester monofilament for the front weft (61) and the back weft (62). is there.
The specifications of the obtained dryer canvas (40) are as shown in FIG.

From the paper contact side (PS side) of the dryer canvas (40), a resin content having the same composition and the same compounding ratio as in Example 1 was placed on the back side while maintaining the speed of a caching roll at 30 m / min. After applying the resin to the (BS side) until the resin permeated, a drying treatment was performed.

[Comparative Example 1] The paper contact side (PS side) of the web layer (10) of the needle canvas (11) having the same specifications as in Example 1.
From a water-absorbing resin containing a hydrophilic group (trade name: SR-620)
0, manufactured by Takamatsu Yushi Co., Ltd.) and a mixture of 10% by weight of water and 90% by weight of water from the paper contact side (PS side) while maintaining the speed of the caching roll at 20 m / min. After being applied until it penetrated to the back side (BS side), a drying treatment was performed.

Comparative Example 2 The paper contact side (PS side) of the web layer (10) of the needle canvas (11) having the same specifications as in Example 1
Fluoro resin (trade name: Dicgard, F-53, manufactured by Dainippon Ink and Chemicals, Inc.) was mixed with 5% by weight and 95% by weight of water. / min while holding at
Side) to the back side (BS side)
A drying process was performed.

Comparative Example 3 A needle canvas having the same specifications as in Example 1 was manufactured. Needle canvas obtained (11)
Was not coated with a resin.

Comparative Example 4 A dryer canvas (70) having the same specifications as in Example 2 was woven. The resin was not applied to the obtained dryer canvas (70).

The following tests A to C were performed to confirm the antifouling effect of the embodiment exemplified in Examples 1 and 2.

(A) Test of antifouling effect on oil-based stains by contaminated liquid (B) Test of antifouling effect on water-based stains by red aqueous ink liquid (C) Water and oil repellency test by water and oil droplets The above test methods and their results will be described respectively. (A) Test of antifouling effect against oily dirt by contaminated liquid 1) Test method 10 g of oily contaminated liquid and 400 cc of water are put into 1 L of a plastic container, well stirred, and put in a thermostat at 60 ° C. Also, 2 g of detergent and 600 cc of water are similarly put in another plastic container.

Example 1 was placed in a plastic container containing a contaminated liquid.
3 cm × prepared according to the specifications of Example 2 and Comparative Examples 1 to 4.
A 3 cm sample is placed and the plastic container is stirred for 30 minutes in a thermostat at 60 ° C.

Each sample was taken out, and each sample was replaced with a plastic container containing a detergent.
Stir for 0 minutes.

Each sample is taken out, air-dried without washing with water, and the degree of contamination is compared.

2) Test results a) The degree of adhesion of dirt was visually compared. As for Example 1, Comparative Examples 1 to 3 (needle needle canvas), Comparative Example 2> Comparative Example 3> Comparative Example 1> Example 1 was found, and it was found that Example 1 had the least amount of dirt attached. On the other hand, in Example 2 and Comparative Example 4 (both made of a fabric canvas), Comparative Example 4> Example 2, and it was found that Example 2 had less adhesion of dirt than Comparative Example 4.

B) In this case, each sample is immersed in a contaminated liquid containing water. It can be seen that Examples 1 and 2 also have a hydrophilic property because they have little adhesion of oily components.

C) FIGS. 5A and 5B show the state of adhesion of dirt on the samples of Examples 1 and 2 and Comparative Examples 3 and 4. FIG. 5A is a photograph showing each sample of Comparative Example 3 and Example 1, and FIG. 5B is a photograph showing each sample of Comparative Example 4 and Example 2. FIG. 5 (A)
As is clear from (B), the samples of the examples have less adhesion of dirt than the comparative examples.

(B) Test of antifouling effect against water-based stains by red aqueous ink liquid 1) Test method Example 1, Example 2, Comparative Example 1 in a beaker containing red ink water (ink 1: water 200) 1 to 4 samples
Let soak for 0 minutes.

Each sample is taken out and washed with water.

Each sample is air-dried and the degree of coloring is compared.

2) Test Results The degree of coloration of the red aqueous ink liquid was visually compared, and as a result, Examples 1 and Comparative Examples 1 to 3 were Comparative Example 1> Comparative Example 3> Comparative Example 2> Example 1. In Example 1, it was found that the adhesion of dirt was the least. On the other hand, in Example 2 and Comparative Example 4, Comparative Example 4> Example 2, and it was found that Example 2 had less adhesion of dirt.

(C) Water repellency and oil repellency test using water drops and oil drops 1) Test method Water drops and oil drops are dropped on the samples prepared from Example 1, Example 2, and Comparative Examples 1-4.

It is observed whether each sample repels water drops and oil drops.

2) Test results The test results are shown in FIG. As is clear from the figure, each sample of Example 1 and Example 2 repels water droplets and oil droplets. Therefore, they exhibit water repellency and oil repellency in air.

From the above experiments (A) to (C), Example 1
And it was confirmed that each sample of Example 2 exhibited an excellent effect of preventing adhesion of dirt. Further, from the test results of (A), it was found that even if dirt adhered, the dirt could be easily washed away by washing the canvas with water or the like. This is presumably because the repellent and oil groups are hidden inside the canvas, and the hydrophilic group of the second resin covers the surface of the canvas.

Furthermore, the excellent water repellency and oil repellency of Examples 1 and 2 are not impaired even when repeatedly carried out in a high steam atmosphere for a long time, and high durability can be exhibited.

The structure of the dryer canvas of the present invention, the material and size of the yarn used, and the like are not limited to the above-described first and second embodiments, and various selections can be made according to the application as long as the same effects are obtained. Is applicable.

The first resin composition described in Example 1, perfluoroalkylethyl acrylate, has a general formula:

[0059]

Embedded image (Where n is an integer of 1 to 8).

The alkyl acrylate has the general formula:

[0061]

Embedded image (Where n is an integer of 1 to 10).

In this embodiment, vinyl alcohol is described as vinyl alcohol, but is not limited thereto.
As shown below as a general formula, any vinyl having a functional group (X) is applicable.

[0063]

Embedded image If the above X is a hydroxyl group (-OH), it is the vinyl alcohol described in this embodiment.

Dipropylene glycol monomethyl ether as a solvent is represented by the following molecular formula.

[0065]

Embedded image

On the other hand, perfluoroalkylethyl acrylate, which is a composition of the second resin, has a general formula:

[0067]

Embedded image (Where n is an integer of 1 to 8).

Further, polyethylene glycol has the general formula:

[0069]

Embedded image (N is an integer of 1 to 10).

[0070] Isopropyl alcohol as a solvent is represented by the following molecular formula.

[0071]

Embedded image

In the embodiment, the method of applying the resin is described by applying the resin until the resin permeates from the paper contact surface side (PS side) to the back surface side (BS side), but is not limited to this method. Needless to say, it may be appropriately selected depending on the use of the dryer canvas. For example, it is possible to apply the resin from the back side (BS side) instead of the back side (PS side) or from both the back side and the back side. It is also possible to increase the number on the application surface side and decrease the number gradually toward the opposite side.

[0073]

The papermaking dryer canvas of the present invention comprises:
During use (in contact with air), it shows water repellency and oil repellency, so it can maintain an excellent antifouling effect without sticking of gummy pitch or other dirt of the sticky oil contained in the paper making process for a long period of time. . Further, even if the dirt adheres, the dirt can be easily removed by washing the canvas with water or the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a papermaking dryer canvas (needle canvas) according to the present invention.

FIG. 2 is a diagram showing specifications of the needle canvas.

FIG. 3 is a cross-sectional view of a papermaking dryer canvas (fabric) according to the present invention.

FIG. 4 is a diagram showing specifications of the textile dryer canvas.

FIG. 5 is a diagram showing the state of adhesion of dirt on each sample of Examples 1 and 2 and Comparative Examples 3 and 4.

FIG. 6 is a diagram showing the results of a repellent water and repulsive oil test using water droplets and oil droplets.

[Explanation of symbols]

 1 Dryer canvas for papermaking (needle canvas) 10 Web layer 11 Base cloth 21 Warp 31 Table weft 32 Medium weft 33 Back weft 40 Dryer canvas for papermaking (made of fabric) 51 Warp 61 Front weft 62 Back weft

Claims (7)

[Claims] 1. A first resin having water repellency and oil repellency,
A papermaking dryer canvas coated with a mixture of a second resin having a hydrophilic group. 2. A first resin having water repellency and oil repellency,
The second one in which a hydrophilic group is added to a resin having repellency and oil repellency
Papermaking dryer canvas coated with a mixture of the above resins. 3. The method of claim 1, wherein the first resin is a mixture or copolymer of a perfluoroalkylethyl acrylate copolymer and a copolymer of another monomer containing an acrylate double bond. Item 4. The papermaking dryer canvas according to item 1 or 2. 4. The resin according to claim 1, wherein the second resin is a mixture or copolymer of a perfluoroalkylethyl acrylate copolymer and an acrylate copolymer containing a polyalkylene glycol moiety. Papermaking dryer canvas according to the above. 5. A method in which a mixture of the first and second resins according to any one of claims 1 to 4 and water is applied from one or both of a paper contact surface side and a back surface side of a canvas. A papermaking dryer canvas in which the impregnation amounts of both resins are increased on the application surface side and gradually decreased toward the opposite side. 6. A mixture of the first and second resins according to any one of claims 1 to 4 and water, which is applied from one or both of a paper contact surface side and a back surface side of the canvas. A method for producing a papermaking dryer canvas, comprising: 7. The method for producing a papermaking dryer canvas according to claim 6, wherein the mixing ratio of the first resin, the second resin, and water is 1-5: 1-5: 90-98 (% by weight). .