JP2001300962A - Method of manufacturing calender roll and laminated sheet - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce surface irregularities and therefore surface roughness,
Provided are a calender roll capable of producing a laminated sheet having excellent smoothness, particularly a pressure-sensitive adhesive sheet, and a method for producing a laminated sheet. The final roll (3) includes a sliding member (41) for smoothing the surface of a plastic material sheet made of a plastic material, a rotating member (41) rotating in the same direction as the final roll, and a smooth surface. The calender roll C is provided with a transfer roll 15 that is provided by transferring and laminating the plasticized material sheet after being formed to a base sheet to form a laminated sheet 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated sheet excellent in surface smoothness, particularly a calender roll suitable for producing a pressure-sensitive adhesive sheet, and a method for producing a laminated sheet using the calender roll.

[0002]

2. Description of the Related Art The structure of a conventional calender roll and a method for producing a laminated sheet of a plastic material sheet and a base sheet using the calender roll are shown in FIG. Indicated. Side roll 1
The plastic material, which is a coating liquid supplied between the top roll 2 and the top roll 2, forms the first bank 11, is rolled by the side roll 1 and the top roll 2, and is taken to the top roll 2 side. Further, the roll is rolled between the top roll 2 and the center roll 3, and at this time, the second bank 12 is formed between these rolls. Further, the plastic material sheet rolled by the top roll 2 and the center roll 3 and adhered to the center roll 3 forms a third bank 13 between the center roll 3 and the bottom roll 4.

On the other hand, a base sheet 31 is
The center roll 3 and the bottom roll 4
Pass between At this time, a plastic material is applied and laminated on the base sheet 31 in the nip portion between the third bank and the center roll 3 and the bottom roll 4, and the laminated sheet 33 is formed.
Is formed. The laminated sheet 33 is taken up by the roll 22 and peeled off from the roll, and then wound up around the roll 23 such that the non-laminated surface of the plastic material sheet is in contact with the back surface of the base material sheet 31.

[0004]

In the above-mentioned known technique, the base sheet 31 is formed by the center roll 3 and the bottom roll.
After the laminated sheet is formed by passing through the nip between the laminated sheet 33 and the center roll 3, the laminated sheet 33 is separated from the center roll 3 by the take-off roll 22. The plastic material layer is strongly adhered and laminated to the base sheet 31, but also adheres to the center roll 3. Therefore, the plastic material surface is peeled off between the center roll 3 and the laminated sheet 33, and as a result, the plastic material surface of the laminated sheet 33 becomes rough,
Irregularities increase. After being wound up by the roll 23, the surface roughness gradually approaches the surface roughness of the base material sheet surface, but does not become completely the same as the sheet surface roughness, and irregularities remain.

[0005] Such irregularities on the surface of the adhesive material cause the following problems. 1) Poor appearance of the product itself. 2) When a transparent base sheet is used, the transparency of the product decreases. 3) Poor adhesion due to a decrease in the adhesion area during use.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laminated sheet having a small surface irregularity and therefore a small surface roughness and having excellent smoothness, particularly a calender roll suitable for producing a pressure-sensitive adhesive sheet, and a laminating method using the calender roll An object of the present invention is to provide a sheet manufacturing method.

[0007]

According to the present invention, a calender roll comprises at least two rolls, and a slide member for smoothing the surface of a plastic material sheet made of a plastic material is provided on the final roll. And a transfer roll for transferring and laminating the plastic material sheet whose surface has been smoothed onto a base material sheet.

With this configuration, the plastic material sheet which has been adjusted to a predetermined thickness and whose surface has been smoothed by the sliding member, the smoothed surface forms the surface of the laminated plastic material sheet layer. In this way, the sheet is transferred to the base sheet to produce a laminated sheet, and thus the obtained laminated sheet has excellent plastic material sheet surface smoothness.

The final roll is the last roll in the flow through which the material to be processed by the calender passes. For example, in a reverse L3 calender roll composed of a side roll, a top roll, and a bottom roll, the bottom roll is This is the final roll.

[0010] In the above calender roll, it is preferable that the sliding member is configured to be heatable. The heating temperature of the sliding member is appropriately set depending on the type of the sliding member and the type of the plastic material used, but is preferably about 50 to 250 ° C. By heating, the surface smoothness of the plastic material can be enhanced, and the transfer of the plastic material sheet to the base sheet can be performed smoothly. If the heating temperature is too low, no effect is observed even if the heating is performed, and if the heating temperature is too high, there arises a problem that the contacting plastic material is decomposed.

In the above calender roll, it is preferable that the sliding member is a roll knife or a coating knife because the surface of the plastic material sheet can be effectively smoothed.

The sliding member for smoothing the surface of the plastic material sheet is made of a material such as metal, resin, or ceramics.
It is preferably made of metal. In order to enable heating, a heater is provided inside, or a passage for circulating a heat medium is formed.

[0013] The present invention is also a method for producing a laminated sheet in which a plastic material sheet is laminated on a base sheet using a calender roll, wherein the calender roll is composed of at least three rolls, A sliding member for smoothing the surface of a plastic material sheet made of a material, and a transfer roll rotating in the same direction as the final roll, wherein the plastic material sheet after the surface is smoothed is The transfer sheet is transferred to the base sheet by a transfer roll to form a laminated sheet.

According to such a production method, a laminated sheet having high smoothness on the surface of the plastic material sheet can be obtained.

The plastic material in the present invention is a material having tackiness in a laminating step using a calendar, and it does not matter whether or not the plastic material has tackiness even after being laminated and cooled. It is preferable that the laminated sheet is a pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive used for the pressure-sensitive pressure-sensitive adhesive sheet can be used without any limitation as long as it is a pressure-sensitive adhesive which can be calendered, and is particularly preferably a rubber-based pressure-sensitive adhesive. The rubber-based pressure-sensitive adhesive is most effectively calendered, but has a strong tackiness, so that according to the conventional technique, the surface of the pressure-sensitive adhesive surface tends to become rough when peeled off from the calender roll. Therefore, according to the present invention, a pressure-sensitive adhesive sheet having excellent smoothness of the adhesive surface can be obtained.

[0017]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a preferred embodiment of the calender roll of the present invention. In this example, the inverse L3
One example of the present calendar roll is shown. The feature of this device is that in a reverse L-three calendar roll C composed of a side roll 1, a top roll 2, and a center roll 3, a center knife 3 has a roll knife 41 on the front position side in the rotation direction, and the rotation rear position. A transfer roll 15 is provided on the side. The transfer roll 15 rotates in the same direction as the center roll 3. Therefore, the opposing surfaces of the center roll 3 and the transfer roll 15 move in opposite directions.

A method for manufacturing a laminated sheet using the apparatus shown in FIG. 1 will be described. The plastic material charged between the side roll 1 and the top roll 2 is supplied to the first bank 11
Is rolled and taken to the top roll 2 side. The sheeted plastic material is further rolled between the top roll 2 and the center roll 3 to form the second bank 12 at this time. Top roll 2 and center roll 3
And the plastic material adhered to the center roll 3 side is taken in a sheet shape on the center roll 3, but the surface of the sheet is separated from the side roll 2 and is in a rough state. The surface of the plastic material sheet on the center roll 3 is smoothed by a roll knife 41.

On the other hand, the base material sheet 31 is unwound from a raw material (not shown) and is fed out from the feeding roll 21, and moves in a direction opposite to the surface moving direction of the center roll 3 by the rotation of the transfer roll 15. The plastic material sheet having the smoothed surface is transferred so as to be scraped off and the laminated sheet 33 is transferred.
To form The laminated sheet 33, which is a product, is taken up by the product take-up roll 23.

FIG. 3 is an enlarged view of an example of a situation in which the plastic material sheet is transferred from the surface of the center roll 3 to the base sheet 31 by the transfer roll 15. Roll knife 4
The plastic material sheet M, the surface of which has been smoothed by
The paper is transferred so as to be scraped off from the surface of the center roll 3 by the base material sheet 31 which moves by the rotation of. At this time, the surface of the plastic material sheet layer in the laminated sheet 33 is smoothed by the roll knife 41 on the uneven surface generated by forcible peeling from the center roll surface, and the surface smoothed by the roll knife 41 is the product Because it is a surface, smoothness is maintained.

The moving speed of the base sheet 31 and the surface speed of the center roll 3 are adjusted to substantially the same speed. If the moving speed of the base material sheet 31 is too slow, the plastic material stays in the transfer portion, and if it is too fast, the plastic material sheet layer is stretched and a predetermined thickness cannot be obtained.

FIG. 2 shows an example of a calender roll C provided with a coating knife (doctor blade) 42 instead of the roll knife 41 which is a sliding member in FIG.

In this example, an example using a reverse L-three calender roll is shown. However, the present invention can be applied to known calenders such as a reverse L-three calender roll, a Z-shaped three to four calender roll, and a six calender roll. it can. In the present invention, since the sliding member does not have a large effect of adjusting the thickness, it is preferable to use a calender roll having at least three rolls in consideration of the degree of freedom of the thickness adjustment.

The transfer roll 15 may be formed of the same metal material as the calender roll, and may be formed of an elastic material such as rubber, since it is only necessary to perform transfer without a function such as thickness adjustment. Is also good. Further, the clearance between the transfer roll 15 and the center roll 3 depends on the type of the base material used,
The thickness is appropriately set in consideration of the thickness, the type of the plastic material, and the like.
If the clearance is too narrow, the base sheet 31 slides strongly against the center roll 3 and its movement is hindered. If the clearance is too wide, the transfer of the plastic material sheet cannot be performed properly, or in some cases, the plastic material partially passes. Problem can occur.

As the raw rubber used for the rubber-based pressure-sensitive adhesive, any rubber used as the pressure-sensitive adhesive can be used without any limitation. Specifically, natural rubber, polyisoprene, polybutadiene,
Synthetic rubbers such as styrene-butadiene rubber, butyl rubber, and ethylene-propylene rubber are exemplified, but use of natural rubber is preferred because strong adhesion is obtained.

Known rubber additives are added to these raw rubbers to form rubber-based pressure-sensitive adhesives. Additives are appropriately selected according to the application, but inorganic materials such as silica, alumina, titanium oxide, magnesium oxide and calcium carbonate, coloring agents such as pigments, antioxidants, antioxidants, tackifiers, and the like. Is exemplified.

As the base sheet, known base sheets can be used without limitation, and specific examples thereof include papers such as kraft paper, and thermoplastic resins such as PET films, OPP films, polyamide films, and polyaramid films. Examples include films and nonwoven fabrics.

[0028]

Next, an embodiment of the present invention will be described in more detail. However, the present invention is not limited only to the following examples.

Example 1 A natural rubber was masticated with a mixing roll to obtain a masticated rubber having a Mooney viscosity of ML _{1 + 4} (100 ° C.) 60. 1500 g of the rubber was charged into a 5-liter pressure kneader heated to 120 ° C., and 750 g of calcium carbonate powder and 30 g of an antioxidant were simultaneously charged and kneaded for 5 minutes. Further, 1350 g of a tackifier was added and kneaded for 20 minutes. Then, it was taken out from the kneader to prepare a pressure-sensitive adhesive composition.

The kneaded material was put into a reverse L-four calender, and a pass line as shown in FIG.
min and coated and laminated. The base sheet 31 has a thickness of 50
A μm OPP sheet was used.

At the time of production, an iron knife coated with hard chromium was used as the roll knife 41 and heated to 150 ° C. using a heat medium to produce a pressure-sensitive adhesive sheet as a laminated sheet.

Comparative Example 1 A sheet was coated at a line speed of 5 m / min in the same manner as in Example 1 except that the pass line shown in FIG. 1 without a roll knife was used.

With respect to the samples of Example 1 and Comparative Example 1 immediately after winding, the surface roughness of the coating film was measured. For the measurement, a surface profile measuring device P-11 (manufactured by Tencor)
, Average roughness Ra (μm), and average height RMS
(Μm) was measured. These results were as shown in Table 1.

[0034]

[Table 1]

As described above, the final roll of the calender roll is provided with a sliding member such as a roll knife for smoothing the surface, and this is transferred to a base material sheet, thereby obtaining the surface roughness of the plastic material layer. Can be reduced, and the appearance and product characteristics of the laminated sheet can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a manufacturing process of a laminated sheet using an inverted L-three calender provided with a roll knife and a transfer roll on a center roll.

FIG. 2 is a diagram illustrating a manufacturing process of a laminated sheet using an inverted L-three calender provided with a coating knife and a transfer roll on a center roll.

FIG. 3 is an enlarged view illustrating a state of transfer of a plastic material sheet in the manufacturing process shown in FIG. 1;

FIG. 4 is a view showing a manufacturing process of a conventional laminated sheet.

[Explanation of symbols]

 C 3 reverse L-calender rolls 31 Base sheet 33 Laminated sheet 41 Sliding member (roll knife)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 101: 12 B29K 101: 12 B29L 9:00 B29L 9:00 (72) Inventor Yasunobu Ina Ibaraki-shi, Osaka 1-1-2 Shimohozumi, within Nitto Denko Corporation (72) Inventor Shuzo Fujiwara 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Inside Nitto Denko Corporation (72) Inventor Kunihiko Kaita, Ibaraki-shi, Osaka 1-1-2 Hozumi F-term (reference) in Nitto Denko Corporation 4F100 AK07A AK42A AK46A AK47A AN00G AN01B AR00B AT00A BA02 CA16 CB05 CB05B DG10A DG15A JB16B JK15 JL13 JL13B4F204 AA01 AG03 FF07 AA01 AC03 FN30 FQ40

Claims (6)

[Claims] 1. It comprises at least two rolls,
On the final roll, a sliding member for smoothing the surface of a plastic material sheet made of a plastic material, and rotating in the same direction as the final roll, transferring the plastic material sheet after the surface is smoothed to a base sheet A calendar roll provided with a transfer roll to be laminated. 2. The calender roll according to claim 1, wherein the sliding member can be heated to 50 ° C. or higher. 3. The calender roll according to claim 1, wherein the sliding member is a roll knife or a coating knife. 4. A method for producing a laminated sheet in which a plastic material sheet is laminated on a base material sheet using a calender roll, wherein the calender roll comprises at least three rolls, and a final roll comprises a plastic material. A sliding member for smoothing the surface of the plastic material sheet, and a transfer roll rotating in the same direction as the final roll are provided, and the plastic material sheet after the surface is smoothed by the transfer roll. A method for producing a laminated sheet, wherein the method is transferred to the base sheet to form a laminated sheet. 5. The method according to claim 4, wherein the plastic material is an adhesive, and the laminated sheet is a pressure-sensitive adhesive sheet. 6. The method according to claim 5, wherein the pressure-sensitive adhesive is a rubber-based pressure-sensitive adhesive.