JP3534139B2 - Coating device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for coating a support running on the front surface of a die with an extrusion type die.

[0002]

2. Description of the Related Art As a coating failure in a coating apparatus using an extrusion type die, foreign matter is caught on the upstream edge of a lip located downstream of a paint discharge slot and facing a support through a certain gap, This foreign substance may cause streaky coating unevenness on the coating surface of the support. Most of the foreign matter is transported to the support.

However, in Japanese Unexamined Patent Publication (Kokai) No. 4071/1992, an undercoat liquid is applied in advance to a support coming into an extrusion type die, and when the support enters the die, an excessive amount of the undercoat liquid is applied to the die. Scraping with the upstream edge of the most upstream lip of the above. In this conventional technique, when the upstream side edge of the most upstream lip of the die scrapes off the undercoat liquid, foreign matter adhering to the support is captured in advance to obtain a good coated surface without coating unevenness. It is a thing.

[0004]

However, the prior art has the following problems. Precoat equipment is required to apply the undercoat liquid to the support in advance.

The undercoating liquid applied to the support enters the die in an unstable flow state in which the physical properties are changed such that the volatile component evaporates as it is exposed to the atmosphere in the process of entering the extrusion die. For this reason, it is necessary to select fine operating conditions for scraping off the undercoating liquid so that the excessive amount of the undercoating liquid whose flow is unstable can be scraped off and the coating material can be satisfactorily applied over it.

The undercoating liquid applied to the support is exposed to the atmosphere during the process of entering the extrusion type die and evaporates volatile components, which may cause environmental pollution.

An object of the present invention is to provide a coating apparatus which is simple in terms of equipment and operation, has no fear of environmental pollution, and has excellent foreign matter removing ability.

[0008]

The present invention according to claim 1 is a coating apparatus for coating a support running on the front surface of a die with an extrusion type die, in which the direction of travel of the support in the die is changed. A liquid discharge slot, a liquid recovery slot, and a paint discharge slot are sequentially provided from the upstream side to the downstream side, the liquid discharged from the liquid discharge slot is collected by the liquid recovery slot, and the paint discharged from the paint discharge slot is used as a support. It is designed to be applied.

According to a second aspect of the present invention, in addition to the first aspect of the present invention, a gap formed between a support and a lip surface of a lip sandwiched between the liquid recovery slot and the paint discharge slot in the die. Of the gap between the lip surface of the lip sandwiched between the liquid discharge slot and the liquid recovery slot and the support, and the gap between the lip surface of the lip located downstream of the paint discharge slot and the support. Each is set to be smaller.

According to a third aspect of the present invention, in addition to the first or second aspect of the present invention, the liquid discharged from the liquid discharge slot has substantially the same composition as the paint discharged from the paint discharge slot, or It is designed to be a compatible liquid.

According to the present invention described in claim 1,
Has the effect of. The foreign matter that has been transported to the support body and has entered the extrusion die is collected together with the liquid discharged from the liquid discharge slot and collected in the liquid collection slot, and removed from the support body. Therefore, the support moving to the paint discharge slot side is prevented from entraining foreign matter on the paint discharge slot side, and foreign matter is caught on the upstream edge of the lip located on the downstream side of the paint discharge slot. It is possible to prevent the occurrence of streaky coating unevenness due to

Since the liquid discharge slot and the liquid recovery slot for collecting and removing the foreign matter are provided in the extrusion type die, and the precoat equipment separate from the extrusion type die is not used, the equipment can be simplified.

The liquid for collecting and removing foreign matter does not move in the closed line including the liquid discharge slot and the liquid recovery slot provided in the extrusion die and is not exposed to the atmosphere. Therefore, there is no change in physical properties such as evaporation of the volatile components of the liquid, and the liquid in a stable flow state is supplied to the support to collect and remove foreign matter, and it is not necessary to select detailed operating conditions and the operation is simple. Is.

The liquid for collecting and removing foreign matters moves in a closed line including a liquid discharge slot and a liquid recovery slot provided in an extrusion type die, and the volatile component of the liquid does not evaporate to the atmosphere, thus causing environmental pollution. There is no fear of

The present invention according to claim 2 has the following effects. The gap between the support and the lip surface of the lip sandwiched between the liquid discharge slot and the liquid recovery slot is A, and the gap between the lip surface of the lip sandwiched between the liquid recovery slot and the paint discharge slot and the support. B, where C is the gap formed between the lip surface of the lip located downstream of the paint discharge slot and the support, A> B and C> B.
Since A> B, the foreign matter larger than the gap B does not enter the lip side sandwiched between the liquid recovery slot and the paint discharge slot, and is reliably recovered and removed to the liquid recovery slot side. Since C> B, even if a foreign substance smaller than the gap B that has not been collected and removed on the liquid collection slot side moves to the paint discharge slot side together with the support, the foreign substance smaller than this gap B is a gap. Since it can pass through the gap C larger than B, it does not get caught on the upstream edge of the lip on the downstream side of the paint discharge slot, and does not cause streak-shaped coating unevenness on the coating surface of the support.

The present invention according to claim 3 has the following effects. When the liquid discharged from the liquid discharge slot is a paint having substantially the same composition as the paint discharged from the paint discharge slot or a liquid such as a solvent having compatibility, the paint discharged from the paint discharge slot is the liquid discharge slot. It is applied to the base surface of the support, which is well wetted with the above-mentioned liquid discharged from the above and is well fitted. Therefore, the paste is well applied to the base surface of the support, and high-speed thin film coating is possible.

[0017]

1 is a schematic diagram showing an example of a coating apparatus, and FIG. 2 is a schematic diagram showing an extrusion type die.

The coating device 10 is an extrusion type coating device, which coats the coating on a continuously running support. Here, the support is plastic,
It is a flexible sheet or web of paper, cloth or metal.
The coating material is a magnetic dispersion liquid, a photosensitive liquid, a heat-sensitive dispersion liquid or an adhesive liquid, which is used to produce a magnetic recording medium, a photographic film, a thermal paper or an adhesive tape, respectively.

The coating device 10 uses an extrusion type die 20 and coats the coating material on the support 1 running in front of the die 20. The support 1 may be mounted between guide rollers (not shown) and run on the front surface of the die 20, and the back surface may not be supported, or may be supported by a backup roller.

The extrusion die 20 includes a liquid discharge slot 21, a liquid recovery slot 22, and a paint discharge slot 23 in order from the upstream side to the downstream side in the support running direction.
have.

Liquid discharge slot 21 and liquid recovery slot 22
Is a liquid circulation line 24 (including a tank 25 and a pump 26)
A pump 26 is connected to the inlet side of the liquid discharge slot 21, and a tank 25 is connected to the outlet side of the liquid recovery slot 22. As a result, the liquid supplied from the liquid discharge slot 21 to the support 1 can be recovered by the liquid recovery slot 22. The liquid discharged from the liquid discharge slot 21 is a paint having substantially the same composition as the paint discharged from the paint discharge slot 23, or a liquid such as a solvent having compatibility.

The paint discharge slot 23 is the paint supply line 2
Connected to 7. As a result, the paint discharged from the paint discharge slot 23 is applied to the support 1.

On the front surface of the extrusion type die 20, there are a first lip 31 located upstream of the liquid discharge slot 21, a second lip 32 sandwiched between the liquid discharge slot 21 and the liquid recovery slot 22, and a liquid recovery slot 22. A third lip 33 sandwiched between the paint discharge slots 23 and a fourth lip 34 located downstream of the paint discharge slot 23 are provided. The gap formed between the lip surface 32A of the second lip 32 and the support 1 is A, the gap formed between the lip surface 33A of the third lip 33 and the support 1 is B, and the fourth.
When the gap between the lip surface 34A of the lip 34 and the support 1 is C, A> B and C> B. That is, the gap B is set to be smaller than each of the gap A and the gap C.

The coating operation of the coating apparatus 10 will be described below. (1) Of the foreign matter 2 conveyed to the support 1, the foreign matter 2A larger than the gap K formed between the lip surface 31A of the first lip 31 and the support 1 is caused by the upstream edge of the first lip 31. It is scraped off and does not enter the first lip 31 side.

(2) Of the foreign matter 2 conveyed to the support 1, the foreign matter 2B smaller than the gap K is the first lip 3
After passing through 1, it enters the second lip 32 side. Then, the foreign matter 2B is supplied to the support 1 from the liquid discharge slot 21 before or after being captured by the upstream edge of the third lip 33 forming the gap B with respect to the support 1. It is recovered together with the liquid recovered in the recovery slot 22 and removed from the support 1. The foreign matter 2B is removed by a filter in the liquid circulation line 24.

(3) Of the liquid discharged from the liquid discharge slot 21 and supplied to the support 1, the support is not recovered by the liquid recovery slot 22 (not scraped off by the upstream edge of the third lip 33). The liquid that came with 1 is the third lip 3
The lower ground surface of the support body 1 that moves to the fourth lip 34 side via 3 is formed. Then, the paint discharged from the paint discharge slot 23 is applied onto this base surface of the support 1.

(4) In the above (2), the third lip 3
The foreign matter 2C smaller than the gap B of 3 is the liquid recovery slot 2
There is a possibility that it may enter the fourth lip 34 side through the third lip 33 without being collected on the second lip side. However, this foreign substance 2
The C passes through a larger gap C (larger than the gap B) formed between the fourth lip 34 and the support 1, and is not caught by the upstream edge of the fourth lip 34.

Therefore, according to this embodiment, there are the following actions. Extrusion type die 20 transported to the support 1
The foreign matter that has entered the inside is collected together with the liquid discharged from the liquid discharging slot 21 and collected in the liquid collecting slot 22, and is removed from the support 1. Therefore, the support 1 moving to the side of the paint discharge slot 23 becomes
3 is prevented from being entrained with foreign matter, and the fourth lip 34 located on the downstream side of the paint discharge slot 23 is prevented.
It is possible to prevent the occurrence of streaky coating unevenness due to the foreign matter being caught on the upstream edge of the.

The liquid discharge slot 21 and the liquid recovery slot 22 for collecting and removing foreign matter are the extrusion die 20.
Since the precoat equipment provided inside and separate from the extrusion die 20 is not used, the equipment can be simplified.

The liquid for collecting and removing foreign matter may move in a closed line (liquid circulation line 24) including the liquid discharge slot 21 and the liquid recovery slot 22 provided in the extrusion die 20, and be exposed to the atmosphere. Absent.
Therefore, the liquid in a stable flow state that does not change the physical properties such as evaporation of the volatile components of the liquid is supplied to the support 1 to collect and remove the foreign matter, and it is not necessary to select detailed operating conditions and the operation is also possible. It's simple.

The liquid for collecting and removing foreign matter moves in the closed line including the liquid discharge slot 21 and the liquid recovery slot 22 provided in the extrusion die 20, and the volatile component of the liquid is not evaporated into the atmosphere. There is no fear of environmental pollution.

Liquid discharge slot 21 and liquid recovery slot 2
A is a gap formed between the lip surface 32A of the second lip 32 sandwiched between the second lip 32 and the support 1, and the lip surface 33A of the third lip 33 sandwiched between the liquid recovery slot 22 and the paint discharge slot 23 is the support 1. Is B, and C is the gap formed between the lip surface 34A of the fourth lip 34 located on the downstream side of the paint discharge slot 23 and the support 1, A> B, C> B is there. Since A> B, the foreign matter 2B larger than the gap B will not enter the liquid recovery slot 2
The liquid is surely recovered and removed to the liquid recovery slot 22 side without entering the third lip 33 side sandwiched between the second and the paint discharge slot 23. Since C> B, even if the foreign matter 2C smaller than the gap B that has not been collected and removed on the liquid collection slot 22 side moves to the paint discharge slot 23 side together with the support body 1, the gap 2B Since the small foreign matter 2C can pass through the gap C larger than the gap B, the fourth foreign matter on the downstream side of the paint discharge slot 23
It is not caught on the upstream edge of the lip 34, and no streaky coating unevenness is generated on the coating surface of the support 1.

When the liquid discharged from the liquid discharge slot 21 is a paint having substantially the same composition as the paint discharged from the paint discharge slot 23 or a liquid such as a solvent having compatibility, it is discharged from the paint discharge slot 23. Further, the coating material is applied to the base surface of the support 1 which is well wetted by the liquid discharged from the liquid discharge slot 21 as described above. Therefore, the paste is well applied to the base surface of the support 1 and high-speed thin film coating is possible.

The present invention is also applicable to a multi-layer coating device in which two or more paint discharging slots are sequentially provided on the downstream side of a liquid discharging slot and a liquid collecting slot, and two or more layers of coating material are overcoated on a support. it can.

[0035]

As described above, according to the present invention, it is possible to obtain a coating apparatus which is simple in terms of equipment and operation, has no fear of environmental pollution, and has excellent foreign matter removing ability.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a coating device.

FIG. 2 is a schematic diagram showing an extrusion die.

[Explanation of symbols]

1 support 2 foreign material 10 Coating device 20 Extrusion type die 21 liquid discharge slot 22 Liquid recovery slot 23 Paint discharge slot 31-34 Lip 31A-34A Lip surface A, B, C, K Gap

Claims (3)

(57) [Claims] 1. A coating device for coating a support body traveling on the front surface of a die using an extrusion type die, wherein a liquid discharge slot is provided in order from the upstream side to the downstream side in the support traveling direction of the die. An application device characterized in that a liquid recovery slot and a paint discharge slot are provided, the liquid discharged from the liquid discharge slot is collected by the liquid recovery slot, and the paint discharged from the paint discharge slot is applied to a support. 2. The gap formed between the support and the lip surface of the lip sandwiched between the liquid recovery slot and the paint discharge slot in the die, and the lip surface of the lip sandwiched between the liquid discharge slot and the liquid recovery slot are supports. 2. The coating apparatus according to claim 1, wherein the gap formed between the coating device and the lip and the lip surface of the lip located on the downstream side of the paint discharge slot are smaller than the gap formed between the substrate and the support. 3. The coating apparatus according to claim 1, wherein the liquid discharged from the liquid discharge slot is a liquid having substantially the same composition or compatibility with the paint discharged from the paint discharge slot.