JPH11228917A - Adhesive polyvinyl chloride tape or sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive polyvinyl chloride tape or sheet which does not suffer from stabilizer bleeding even when it contains a stabilizer in an amount sufficient for rolling and has excellent adhesiveness. SOLUTION: There is provided an adhesive polyvinyl chloride tape or sheet composed of a support comprising a polyvinyl chloride composition based on a polyvinyl chloride and an adhesive formed on either of the surfaces of the support, wherein the polyvinyl chloride composition contains 0.01-5 pts.wt., per 100 pts.wt. polyvinyl chloride, at least either of magnesium hydroxide and magnesium oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl chloride-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed on at least one surface of a substrate made of a polyvinyl chloride-based composition.

[0002]

2. Description of the Related Art Conventionally, polyvinyl chloride (hereinafter referred to as "PV
PVC) comprising a pressure-sensitive adhesive layer formed on one or both sides of a film substrate obtained by processing
A system-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet is widely used for applications such as electrical insulation, packaging, and protection because of its excellent workability. In order to form the above-mentioned PVC into a sheet, a rolling method using a calender is often used. In particular, as a support base material for an adhesive tape or an adhesive sheet, since there are many requirements for hardness, thickness, color, etc., and the amount of use per requirement is small, a calender film product suitable for small lot production is mainly used. It is used for In the above calender film forming method (hereinafter referred to as "rolling method"), workability is required in which a thin film is formed between high-temperature rolls and the film is simultaneously separated from the high-temperature roll. In addition, the PVC has a high processing temperature and a high P.
Since the decomposition initiation temperatures of VC are close to each other, there is known a method of preventing decomposition (or dehydrochlorination) by using various stabilizers in this PVC. As described above, the above-mentioned releasability and prevention of dehydrochlorination are dealt with by using a stabilizer. As a stabilizer capable of imparting both the properties of the above-described releasability and prevention of dehydrochlorination, metal fatty acid salts are used. It has been known. Further, the metal fatty acid salt may be added in a small amount, and a high peeling effect can be obtained at the time of processing, and it is excellent in workability in addition to the advantage of low production cost.

[0003] However, it is known that, with the exception of some compounds, the above-mentioned stabilizer bleeds out (bleeds) onto the surface of the PVC film as the amount of the stabilizer added increases. Particularly, among the stabilizers, the above-mentioned metal fatty acid salt has a remarkable tendency. The bleed phenomenon does not occur under a fixed condition, but occurs when factors such as environmental conditions and materials used overlap the conditions under which the bleed occurs. In the rolling method of PVC containing a stabilizer, there is no other method than confirming the peeling effect and suppressing the stabilizer to the smallest possible amount.

[0004] Since such a bleed of the stabilizer causes a decrease in the adhesive strength of the adhesive tape, it has been a conventional problem to prevent the decrease in the adhesive strength. A method of reducing the compounding amount of the agent has been adopted.

[0005]

Accordingly, the above stabilizer is designed to maintain sufficient stability during PVC rolling and to be added in such an amount that no bleeding occurs when molded as an adhesive tape. There must be. However, thermal degradation during film processing and the inability to peel off from the metal roll surface during rolling are very important problems in production, so that the stabilizer should be added to a certain excessive amount. As a result, bleeding of the stabilizer occurs. However, as described above, the bleeding of the stabilizer is influenced by the environment to which it is exposed (temperature conditions, humidity conditions, etc.), and under certain conditions. Is not expressed in Therefore, bleeding of the stabilizer suddenly appears and covers the PVC film.

Meanwhile, as one of the conditions for the occurrence of bleeding of the above stabilizer, it is considered that humidity is considered to have a large effect, and the climate of Japan is influenced. further,
In recent years, in the process of manufacturing adhesive tapes, emulsion-type primers and adhesives have been developed one after another in order to ensure the environment and safety, and in these application and drying processes, they will be exposed to high-temperature and humid conditions. More severe conditions are expected, and some measures against bleeding of the stabilizer are desired.

Normally, the stabilizer bleeding on the surface of the PVC film stays at the interface between the film surface and the pressure-sensitive adhesive layer. In such a situation, when the pressure-sensitive adhesive tape is rewound, the bleeding stabilizer migrates to the surface of the pressure-sensitive adhesive layer and covers the surface of the pressure-sensitive adhesive layer, thereby impairing the adhesive force that should be originally obtained.

The present invention has been made in view of such circumstances, and even when a stabilizer is added in an amount sufficient for rolling, the stabilizer does not bleed and a PVC-based pressure-sensitive adhesive tape having excellent tackiness is used. The purpose is to provide an adhesive sheet.

[0009]

In order to achieve the above object, a PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet of the present invention comprises:
A PVC-based pressure-sensitive adhesive tape or sheet in which a pressure-sensitive adhesive layer is formed on at least one surface of a substrate composed of a PVC-based composition containing PVC as a main component, wherein the PVC-based composition has the following (A) The composition is such that the components are contained in a proportion of 0.01 to 5 parts by weight with respect to 100 parts by weight of PVC. (A) At least one of magnesium hydroxide and magnesium oxide.

That is, the present inventors have proposed a PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet which does not bleed even if a sufficient amount of the stabilizer is added for rolling or the like and does not cause a reduction in adhesive strength. Intensive research was conducted to obtain a PVC-based base material as a support base material. As a result, when a specific proportion of at least one of magnesium hydroxide and magnesium oxide (component (A)) is blended together with PVC and a stabilizer in a PVC composition as a material for forming the PVC base material, The present inventors have found that bleeding of the stabilizer can be effectively prevented without lowering the properties and strength, and arrived at the present invention.

When a fatty acid metal salt is blended in the PVC composition, the effect of preventing the deterioration is obtained by supplementing the dehydrochlorination of PVC, and the effect of lubricity during processing is obtained.

Further, among the above-mentioned fatty acid metal salts, when at least one selected from the group consisting of zinc stearate, calcium stearate and barium stearate is used, more excellent deterioration preventing effect and lubricating effect can be obtained. Can be

[0013]

Next, embodiments of the present invention will be described in detail.

The PVC-based pressure-sensitive adhesive tape or sheet of the present invention takes a form in which a PVC-based substrate and a pressure-sensitive adhesive layer are formed on at least one surface of the PVC-based substrate.

[0015] The PVC base material is a special PVC base material.
System composition can be obtained as a forming material, and the above P
The pressure-sensitive adhesive layer formed on at least one side of the VC base material can be obtained using various pressure-sensitive adhesives as a forming material.

The above-mentioned special PVC-based composition can be obtained by using a specific component (component A) for preventing bleeding of the stabilizer, together with PVC and a stabilizer as main components. In addition, the said main component means the substantial component which determines the basic property of this PVC-type composition as well as the usage-amount.

Although there is no particular limitation on the PVC,
The polymerization degree of the suspension polymerization is preferably set in the range of 800 to 1500, and from the viewpoint of good processability, the polymerization degree in the range of 1000 to 1300 is particularly preferable.

The stabilizer is not particularly limited, and various compounds generally used as stabilizers for PVC are used, and various combinations are selected according to applications and requirements. Usually, they are classified according to the characteristics required at the time of processing. They are roughly classified into a compound that imparts heat resistance that complements the dehydrochlorination of PVC, and a peeling property from a metal surface of a calender during film formation (hereinafter referred to as “slipperiness”). And a compound that imparts

Examples of the former compound imparting heat resistance include lead compounds such as dibasic lead phthalate, tribasic lead sulfate, and dibasic lead phosphite. Furthermore, examples of the lead-free compound include a hydrotalcite-based compound, an organotin-based compound, a phosphite-based compound, a polyol-based perchlorate, and a zeolite.

The latter compound which imparts lubricity includes hydrocarbon lubricants, fatty acid lubricants, higher alcohol lubricants, aliphatic amide lubricants, fatty acid metal salt (metal soap) lubricants, and ester lubricants. And the like. Above all, the fatty acid metal salt-based lubricant has much bleed on the film surface due to high lubricity, but is particularly preferable because it has both the effect of preventing deterioration and the high lubricity effect.

Examples of the above fatty acid metal salt-based lubricant include metal salts such as barium, calcium and zinc such as fatty acid salts such as stearic acid and maleic acid. Among them, zinc stearate, calcium stearate, and barium stearate are preferably used from the viewpoints of dehydrochlorination deterioration during processing, transparency, toxicity, and sulfide discoloration. These may be used alone or in combination of two or more.

And, the above-mentioned special PVC-based composition includes:
Specific components (component (A)) such as magnesium hydroxide and magnesium oxide are used together with PVC and a stabilizer as main components. These are used alone or in combination. By using the component A, bleeding of the stabilizer can be effectively prevented. The bleed prevention effect of the stabilizer by using the above-mentioned component A is not clear, but by adding the above-mentioned component A to change the ionicity in the PVC base material, for example, P
This is considered to be the result of affecting the bleeding phenomenon of the fatty acid ions present in the VC base material onto the base material surface.

[0023] In addition to the PVC, the stabilizer and the component A as a specific component, other additives such as a plasticizer, a filler, a pigment and an elastomer can be appropriately added to the PVC composition. . The types and amounts of the other additives are not particularly limited, and may be appropriately set according to the application.

The above-mentioned plasticizer is not particularly limited, and phthalate esters, adipic acid polyesters, adipic esters, trimellitic esters, pyromellitic esters, epoxidized soybean oils, epoxy resins generally used as PVC plasticizers Linseed oil, chlorinated paraffin and the like. These may be used alone or in combination of two or more.

As the filler, a conventionally known mineral-based filler is used.

As the pigment, conventionally known carbon-based, titanium-based, cyan-based, and azo-based pigments are used.

The above elastomer is used for imparting processability, impact resistance and the like. Specifically, chlorinated polyethylene, ethylene-vinyl acetate copolymer (EV
A), butadiene-styrene-methyl methacrylate terpolymer (MBS), acrylonitrile-butadiene-styrene copolymer (ABS) and the like are used.

The content ratio of each component in the special PVC composition is as follows. At least one of the above magnesium hydroxide and magnesium oxide (A
It is necessary to set the content ratio of the component) in the range of 0.01 to 5 parts with respect to 100 parts by weight of the above PVC (hereinafter abbreviated as “part”). Particularly preferably, it is in the range of 0.05 to 0.5 part. That is, the content ratio of the component A is 0.01
If the amount is less than 5 parts, the effect of preventing bleeding cannot be obtained. If the amount exceeds 5 parts, a dehydration reaction occurs during processing, resulting in a loss of workability due to foaming, a decrease in color tone due to a large amount of blending, and a reduction in strength.

The content ratio of the above stabilizer is the same as that of the above PV
The content is preferably set in the range of 1 to 10 parts, and particularly preferably in the range of 1 to 5 parts, with respect to 100 parts of C. The content of the plasticizer is 10 parts per 100 parts of the PVC.
It is preferably set in the range of from 100 to 100 parts, and particularly preferably in the range of from 30 to 60 parts.

On the other hand, the pressure-sensitive adhesive is not particularly limited, and a conventionally known pressure-sensitive pressure-sensitive adhesive such as rubber or acrylic can be used. Examples of the pressure-sensitive adhesive include those appropriately containing a natural rubber, a temperphenol-based tackifier, and a phenol-based antioxidant. An emulsion-type adhesive is used. Examples of the emulsion-type adhesive include natural rubber latex and styrene-
Examples include a rubber-based pressure-sensitive adhesive appropriately containing a butadiene rubber (SBR) latex, a water-dispersed tackifying resin, and an acrylic pressure-sensitive adhesive obtained by emulsion polymerization.

The PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet of the present invention can be produced, for example, as follows. That is, first, the PVC, the stabilizer, the component A which is a specific component, and other additives are mixed to form a PVC.
A system composition is prepared. On the other hand, a natural rubber, SBR, petroleum-based, terpene-based tackifying resin, phenol-based antioxidant, etc. are mixed to prepare a pressure-sensitive adhesive. Next, the PVC composition is kneaded on a roll to obtain a PV of a predetermined thickness.
After preparing the C-based substrate, the pressure-sensitive adhesive is applied to one or both surfaces of the PVC-based substrate, and a pressure-sensitive adhesive layer is formed through a predetermined process. Then, this is wound up in a tape shape, or processed into a sheet shape by a conventionally known calendering process or the like, so that a desired PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet can be produced. The shape of the PVC base material is not particularly limited, and examples thereof include a film shape and a sheet shape.

In the thus obtained PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet, a layer using an undercoating agent between the pressure-sensitive adhesive layer and the PVC film layer, or a layer opposite to the surface on which the pressure-sensitive adhesive layer is formed, A layer using a back surface treatment agent may be provided as another layer as necessary.

As the undercoating agent, those obtained by graft polymerization of acrylic acid to natural rubber or the like are used.

Examples of the back surface treating agent include a long-chain alkyl type and a silicon type.

In the thus obtained PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet of the present invention, the thickness of the PVC-based substrate is usually set in the range of 0.05 to 1 mm, preferably 0.08 to 0. The range is 4 mm. The thickness of the pressure-sensitive adhesive layer formed on at least one side of the PVC-based substrate is usually set in a range of 0.01 to 0.5 mm, and preferably in a range of 0.02 to 0.2 mm.

The PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet of the present invention is, for example, a pressure-sensitive adhesive tape for electrical insulation, a pressure-sensitive adhesive tape for packaging, a pressure-sensitive adhesive tape for medical use, a pressure-sensitive adhesive tape for printing, a pressure-sensitive adhesive sheet for printing, a pressure-sensitive adhesive sheet for marking, a pressure-sensitive adhesive for masking. tape,
It can be used for applications such as anticorrosive adhesive tapes.

Next, examples will be described together with comparative examples.

[0038]

Examples 1 to 12 and Comparative Examples 1 to 6
Each component shown in Table 3 was blended at the ratio shown in the same table, and PVC was added.
A system composition was prepared. Next, the PVC composition was kneaded on a roll to produce a sheet substrate having a thickness of 0.2 mm.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

The sheet substrates of the example product and the comparative example product thus obtained were subjected to 35 ° C. × 80% humidity, 60 ° C. ×
After pouring into tap water at a humidity of 95% and a temperature of 70 ° C. for 3 days, the state of the stabilizing agent on the sheet surface was visually observed. When no bleed was seen on the sheet surface, it was evaluated as 、, when bleed was seen thinly on the sheet surface, as △, and when bleed was clearly observed by wiping, as ×, and the results were evaluated in the following table. 4 to Table 5 together.

Further, using each of the above-mentioned sheet substrates, a PVC tape (No. 21, manufactured by Nitto Denko Corporation) was applied to the above-mentioned sheet substrate.
(Thickness: 0.2 mm × width: 19 mm × length: 20 m) was adhered under normal temperature conditions, put in a state of 35 ° C. × 80% humidity for 5 days, returned to normal temperature, and measured for peel strength. The peeling measurement method was based on the adhesive force measurement method of JIS Z0237. The results are shown in Tables 4 and 5 below.

[0044]

[Table 4]

[0045]

[Table 5]

From the results shown in Tables 4 and 5, the sheet material of the example product did not show any bleed under any of the conditions, or was subjected to the harsh condition of being introduced into 70 ° C. tap water. Bleed was confirmed to be thin on the sheet surface. Further, the adhesive strength was excellent. In contrast, Comparative Examples 1 and 2 containing neither magnesium hydroxide nor magnesium oxide had 35
Clear bleed was confirmed in each of the samples fed into tap water at 80 ° C. × 80% and 70 ° C. Also, the adhesive strength was lower than that of the example. In Comparative Examples 3 and 5 in which the content of magnesium hydroxide and magnesium oxide was less than 0.01 part, bleeding of the stabilizer on the sheet substrate surface was confirmed,
The effect of the addition could not be obtained. In Comparative Examples 4 and 6 in which the contents of magnesium hydroxide and magnesium oxide exceeded 5 parts, the effect of preventing bleeding on the sheet substrate surface was obtained, but the discoloration of the sheet substrate was remarkable, and The value of the product was reduced, and a product with no practical use was obtained.

Of the sheet base materials thus obtained, at least one of natural rubber latex, SBR latex and water-dispersed tackifying resin is used as an adhesive on one side of the sheet base material of the example product. A pressure-sensitive adhesive sheet was produced by forming a pressure-sensitive adhesive layer having a thickness of 0.03 mm by applying a rubber-based emulsion-type pressure-sensitive adhesive in which the two were blended. The obtained pressure-sensitive adhesive sheet was placed under the above-mentioned conditions (35 ° C. × 80% humidity, 60 ° C. × 95% humidity, 70 ° C. tap water) for 3 days, and observed.
The bleeding phenomenon of the stabilizer from the PVC base material was not exhibited and was excellent.

[0048]

As described above, the PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet of the present invention can be used for forming a PVC-based base material.
Since the C component contains the aforementioned component A at a specific ratio, PVC can be used without lowering workability and strength.
Bleeding of the stabilizer in the base material is prevented, and as a result, the addition of the stabilizer has the effect of preventing slippage and deterioration, and also prevents the adhesive strength from being reduced due to the bleed. Therefore, the PVC-based pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet of the present invention is an electric insulating pressure-sensitive adhesive tape, a packaging pressure-sensitive adhesive tape, a protective pressure-sensitive adhesive tape, a medical pressure-sensitive adhesive tape, a printing label base paper, a labeling pressure-sensitive adhesive sheet, a masking pressure-sensitive adhesive tape, It can be suitably used for applications such as anticorrosive pressure-sensitive adhesive tapes.

When a fatty acid metal salt is blended into the PVC composition, the effect of preventing the deterioration by supplementing the dehydrochlorination of PVC and the effect of lubrication during processing are obtained.

Further, when at least one selected from the group consisting of zinc stearate, calcium stearate and barium stearate is used among the above-mentioned fatty acid metal salts, the more excellent deterioration preventing effect and lubricating effect can be obtained. Can be

Further, an emulsion-type adhesive is used as a material for forming an adhesive layer of a PVC-based adhesive tape or an adhesive sheet, and even when subjected to severe conditions such as exposure to a high-temperature and high-humidity state in these coating and drying steps, it is stable. An agent having excellent adhesive strength can be obtained without bleeding of the agent.

Claims (4)

[Claims] 1. A polyvinyl chloride-based pressure-sensitive adhesive tape or sheet comprising a pressure-sensitive adhesive layer formed on at least one surface of a substrate comprising a polyvinyl chloride-based composition containing polyvinyl chloride as a main component. A polyvinyl chloride-based pressure-sensitive adhesive tape or pressure-sensitive adhesive characterized in that the following component (A) is contained in a polyvinyl chloride-based composition at a ratio of 0.01 to 5 parts by weight based on 100 parts by weight of polyvinyl chloride. Sheet. (A) At least one of magnesium hydroxide and magnesium oxide. 2. The polyvinyl chloride-based pressure-sensitive adhesive tape or sheet according to claim 1, wherein a fatty acid metal salt is blended in the polyvinyl chloride-based composition. 3. The pressure-sensitive adhesive tape or sheet according to claim 2, wherein the fatty acid metal salt is at least one selected from the group consisting of zinc stearate, calcium stearate and barium stearate. 4. The pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer is formed using an emulsion-type pressure-sensitive adhesive.