JPS6286079A - Adhesive tape and preparing same - Google Patents

Abstract

PURPOSE:To obtain an adhesive tape which is excellent in adhesive power and causes no adhesive squeezing-out even when it is rolled up, by providing an adhesive layer on the surface of a rough and manually tearable flexible tape support through the medium of a smooth and thin layer made of a water- dispersed, high-molecular material contg. fine bubbles. CONSTITUTION:A water-dispersed, high-molecular material contg. fine bubbles is applied on the surface of a flexible tape support which is rough macroscopically and manually tearable (e.g., paper or nonwoven fabric) to attain a substantially direct bonding of a thin layer contg. fine bubbles having a smooth surface and an inner break strength higher than that of an adhesive layer. Examples of the water-dispersed high molecular material contg. fine bubbles include a compsn. obtd. by mixing a rubber latex with a foaming agent (e.g., alkyl sulfosuccinate), a structural reinforcing agent (e.g., epoxy resin), a tackifier (e.g., terpene resin), etc. An adhesive layeris provided on the thin layer contg. fine bubbles to obtain an intended adhesive tape.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a novel adhesive tape and a method for manufacturing the tape.

<Prior art and its problems> Adhesive tapes usually have a structure in which an adhesive layer is provided on the surface of various tape supports, either directly or via an undercoat layer. When applied to an ordinary smooth adherend surface, the adhesive tape can be used without any problems in terms of adhesion, but when applied to an adherend surface with a rough surface such as corrugated paper, At present, it is not always possible to obtain sufficient adhesive strength.

In general, attempts have been made to increase the thickness of the adhesive layer as a way to increase adhesive strength, but when the adhesive tape is wound into a roll, the adhesive oozes out to the sides, and when the tape roll is wound. This has the disadvantage that not only does it cause scratches (the phenomenon of rubbing <F9r=g'4), which impairs the appearance of the tape, but it is also uneconomical.

In addition, as other methods, attempts have been made to improve the composition of the adhesive by using adhesion-imparting resins and softeners that exhibit high adhesive strength, but these materials It has disadvantages that it is expensive and that it is complicated to achieve a balance between adhesive force and cohesive force in terms of composition.

On the other hand, when a porous material such as paper, non-woven fabric, woven fabric, knitted fabric, foamed film or sheet is used as the tape support,
If adhesive liquid is applied directly to the tape support, the adhesive liquid will be impregnated into the tape support, so a large amount must be applied by anticipating the amount of impregnation in advance. There is a disadvantage that the texture of the porous material is lost by impregnation with the adhesive liquid, so the adhesive liquid is coated on a release paper or similar article and dried: After forming an IEL film, the porous material surface is coated with the adhesive liquid and dried. A method has also been proposed in which the adhesion between the porous material and the adhesive film is poor. This paper proposes a new adhesive tape that solves the drawbacks of the technology and a method for manufacturing the tape. between a flexible tape support and an adhesive layer for application to an adherend surface; A thin layer containing microbubbles having breaking strength is interposed therebetween.

Another aspect of the present invention is to apply microfoam-containing water-dispersed polymeric material or a blowing agent to the surface of a microscopically rough, substantially hand-cuttable, flexible tape support. A method for producing an adhesive tape, characterized in that a thin layer containing microbubbles with a substantially smooth surface is formed by applying and drying a polymeric material containing a microfoam, and an adhesive layer is provided on the surface of the layer. It provides:

According to the invention, a microfoam-containing thin layer is provided between the tape support and the adhesive layer, which is substantially directly bonded thereto and has a greater internal rupture strength than the adhesive layer. Therefore, strong adhesive force can be obtained with a thin glue thickness, and since the glue thickness can be made thin, there is no glue extrusion or slippage, and it is economical, and there is no need for a particularly special compounding composition. It's something that doesn't exist.

Furthermore, since the adhesive tape is manufactured by directly applying and drying a water-dispersed polymeric material with high viscosity and containing microbubbles or a polymeric material containing a foaming agent onto the tape support, the tape support has no pores. Even if it is a porous material, each of the polymer materials described above has excellent quality because it follows the rough surface of the porous material and forms a strong contact interface without being impregnated at all or hardly. Adhesive tape can be provided in large quantities.

The tape support used in carrying out the present invention may be made of a porous material such as paper, non-woven fabric, mounting surface, knitted fabric, foamed film or sheet, or a combination of the porous material and a plastic film, metal foil, etc. The effect is best achieved when the product is used in combination with a thin sheet material, but it is far superior to the thin sheet material alone or a composite thereof. However, these tape supports, which have finely rough surfaces, have various materials, floats, molding processes, etc. that are selected, and can be virtually cut without the need for cutting tools such as scissors or tape cutters. For handling purposes, it is necessary to be able to cut the material by hand.

The thin layer containing microbubbles, which is applied directly to the surface of the tape support (particularly in the case of porous materials), consists mainly of rubber latex and L
A foaming agent, a structural reinforcing agent, and an adhesion-imparting resin as needed are mixed into this mixture, and the mixture is stirred by a machine.
Microbubbles-containing water-dispersed polymeric material adjusted to a viscosity of 3 to 500 poise, preferably lO to 300 poise (each at 25°C), with a thickness of 1 to 1000 poise, is placed on the entire tape support.
μm, preferably in the range of 5 to 100 μm, and after pre-drying usually at 70 to 90°C for 1 to 3 minutes,
By drying at 100 to 140° C. for 2 to 5 minutes, a product having approximately the same thickness as the coating thickness can be obtained.

The formulation includes natural rubber (NR), styrene/butage/
Com (S B R), Nido-1 Norbutadiene Rubber (N
BR), rubbers such as acrylic rubber, or synthetic resins such as polyvinyl chloride, polyvinylidene chloride, polyethylene, etc. (solid content is preferably 40 to 70M), solid content 1oo, per IH part, Add 3 foaming agents such as potassium oleate and alkyl sulfosuccinamate.
~83 tit parts, methoxymethylolmelamine, sulfur, 2 to 10 parts by weight of structural reinforcement agents that improve the matrix strength of thin layers such as epoxy resins, terpene resins,
It is preferable that the amount of a core-imparting resin such as a terpene phenol resin, rosin, a rosin derivative, or a petroleum resin is contained in an amount of 0 to 20 parts by weight, preferably 10 to 100 parts by weight. Thus, further thickeners, fillers, structural reinforcement aids, etc. can be added to the formulation. The use of the resin is preferred because it improves the water resistance of the thin layer and improves the adhesion between the thin layer and the adhesive layer.

The composition thus constituted is mixed and stirred for usually 1 to 10 minutes with a mechanical stirrer at 100 to 3000 rotations/min to form a mixture containing fine bubbles of 1 to 100 μm in the system.
It is said to be a water-dispersed polymer material with a temperature of 500 poise (at 25°C). If the viscosity of the material is less than 3 poise (at25'C), although it contains foaming, it is not preferable because it may be impregnated into the porous material;
If the temperature exceeds 25°C, it becomes difficult to coat, which is undesirable.The water-dispersed polymer material prepared in this way is coated on the tape support to a predetermined thickness, as described above. When dried, the microbubbles in the water-dispersed polymeric material do not undergo any substantial change in size and shape (with microbubbles of 1 to 1000 μm in the foamed state of 1 to 20 times, preferably 2 to 13 times). It is considered to be a thin layer.

Therefore, the formulation composition is adjusted to have a hardness with a compressive load of 10 to 1000 g, Δ" at 50t4 compression, and an internal fracture strength of the adhesive layer (generally about i
100 g/3 larger than oo~7009/ex)
Above, preferably in the range of 120 to 2,500 i)%+, it may cause wobbling, and if it exceeds 1,000 t/ex, the flexibility of the tape will be inhibited and the adhesive slipperiness of the tape on rough surfaces will be reduced. If the internal breaking strength is less than ioog, Δ, cohesive failure may occur within the layer when the tape is rewound or peeled from the adherend, which is not preferable.

The thin layer can be formed of a polymeric material containing a foaming agent, in addition to the microfoam-containing water-dispersed polymeric material whose main component is rubber tex as mentioned above. , dioctyl phthalate, process oil,
Paraffin, lubricating oil, coal tar, aliphatic oil, wax, low-weight tetramine, azodicarbonamide, valatoluenesulfonylhydrazine, 1 to 20 parts by weight of blowing agents such as sodium bicarbonate, sulfur, methylolmelamine, epoxy resin, quinone. It contains 0.5 to 10 parts by weight of a structural reinforcing agent such as dioxime or peroxide, and other fillers, pigments, lubricants, ultraviolet absorbers, etc. can be added as necessary.

The polymeric material is dissolved in an organic bath agent or dispersed in water and adjusted to a viscosity of 3 to 500 poise (at 25°C), or melted at a temperature below the decomposition temperature of the blowing agent,
It is coated or laminated onto a tape support such as a porous material or a film base material to a thickness of 1 to 1000 μm, preferably 5 to 100 μm, and usually at 60 to 200°C.
The foam is vulcanized by heating under compression using a roll or the like for 1 to 20 minutes to form a thin layer containing microbubbles with a smooth surface. Even for a thin layer made of this system, it is desirable for the expansion ratio, cell size, hardness, and internal fracture strength to be set within the above-mentioned ranges for the same reason.

As mentioned above, the fine bubble-containing thin layer can provide good adhesion even if it is applied directly to the surface of the tape support, but if necessary, the tape support surface may be subjected to oxidation treatment such as corona discharge treatment or treatment. An undercoat layer may be provided with a thickness within a range that does not inhibit the surface shape of the base coat.

The thin layer formed in this way is provided with an adhesive layer mainly made of rubber or synthetic resin, and is used as the adhesive tape of the present invention. The adhesive used may be a solution type, an emulsion type, a melt type, etc., and the layer thickness is 5.
~200 pm.

<Effects of the Invention> Since the adhesive tape of the present invention is constructed as described above, a strong adhesive force can be obtained with a thin adhesive layer, and even when it is wound into a roll, there is no side run-out or unwinding. It has the characteristic that it can be manufactured at low cost.

<Example> Implementation v1 of the present invention will be shown below.

Practical row 1 The formulations shown in Table 1 were pattern-stirred for 3 minutes with an oak mixer at 10 to 3000 rpm while injecting air.
Obtaining a microbubble-containing water content polymeric material having cells of 0 to 30 μm 1. On the other hand, polylaminated paper is prepared by laminating a 20 μm thick polyethylene film on one side of kraft paper with a basis weight of 73′i/rd.

Next, the polymer material 1 was applied to the non-laminated side of the polylaminated paper and pre-dried (1, n
Dry at ooC for 2-4 minutes to obtain a viscous thin layer containing microbubbles with cells of 15-40 μm on the non-laminated side of the polylaminated paper.

This thin layer surface has an internal breaking strength of 30097 cm (first
Table A, B and D) and 100 q/s (m 1 table OC
) was formed to a predetermined thickness to obtain an adhesive tape of the present invention.

Note that all the parts of the formulations shown in Table 1 are for hard cedar.

The internal fracture strength in Table 1 is as shown in Table 1.
At the same time, paper was adhered to the surface, a cut was made in the thin film, and it was peeled off at 180 degrees. This shows the evaluation results of an adhesive tape made by forming a thin layer using a water-dispersed polymer material.The comparative example is an adhesive tape made without a thin layer. Adhesive force, tack (ball j≦), and holding force were measured according to JIS Z-0237.

In addition, side extrusion and unwinding were determined by touch and visual observation after storing the adhesive tape (width 50mm) at 35°C x 80% R,H for 48 hours. are mixed uniformly with a stirrer to obtain a polymeric material containing a foaming agent.

Is this 50μ thick? Coat it on the polyester film surface of n using a doctor knife coat and heat it at 80-85℃ for 1~
Preheating is carried out for 2 minutes and foaming is carried out by heating at 130 DEG C. for 2 minutes for formulation E and 15 minutes at 200 DEG C. for formulation G to obtain a microfoam-containing thin layer with cells of 15-100 .mu.m.

A natural rubber-based pressure sensitive adhesive having an internal breaking strength of 30097ax was formed on the thin layer surface to a predetermined thickness to obtain an adhesive tape of the present invention.

Tables 3 and 4 show the evaluation results of adhesive nerves made using polymeric materials containing blowing agents of formulations E1F and G in Example 2.

Table 4

Claims (1)

[Scope of Claims] 1) Between a microscopically rough, substantially manually cuttable, flexible tape support and an adhesive layer for application to an adherend surface. Adhesive tape 2 characterized in that a thin layer containing microbubbles is interposed therein, the layer being substantially directly bonded to the tape support and the adhesive layer and having a higher internal breaking strength than the adhesive layer. 2.) Adhesive tape according to claim 1, wherein the tape support is a porous material such as paper, non-woven fabric, woven fabric, knitted fabric, foamed film or sheet. 3) The adhesive tape according to claim 1, wherein the thin layer containing microbubbles has an internal breaking strength of 100 g/cm or more. 4) The hardness of the microfoam-containing thin layer is 10 to 10 when compressed by 50%.
The adhesive tape according to claim 1 or 3, which has a compressive load of 00 g/cm^2. 5) The size of cells in the thin layer containing microbubbles is 1 to 1000μ
The adhesive tape according to claim 1 or each of claims 3 to 4, which is m. 6) The adhesive tape according to claim 1 or any one of claims 3 to 5, wherein the thin layer containing microbubbles has a thickness of 1 to 1000 μm. 7) A water-dispersed polymeric material containing microbubbles is coated on the surface of a flexible tape support that is microscopically rough and can be cut by hand, and dried so that the surface becomes substantially smooth. 1. A method for producing an adhesive tape, which comprises forming a smooth microfoam-containing thin layer by substantially directly bonding the layer, and providing an adhesive layer on the surface of the layer. 8) The method for producing an adhesive tape according to claim 7, wherein the microfoam-containing water-dispersed polymeric material contains at least a foaming agent and a structural reinforcing agent in rubber latex. 9) The method for producing an adhesive tape according to claim 7, wherein the microfoam-containing water-dispersed polymeric material contains rubber latex at least a foaming agent, a structural reinforcing agent, and an adhesion-imparting resin. 10) The viscosity of the water-dispersed polymer material containing microbubbles is 3 to 500.
A method for producing an adhesive tape according to any one of claims 7 to 9, which is poise (at 25°C). 11) A polymeric material containing a foaming agent is coated on the surface of a flexible tape support that is microscopically rough and can be cut by hand, and dried to make the surface substantially smooth. 1. A method for producing an adhesive tape, which comprises forming a thin layer containing fine bubbles by substantially directly bonding the layer, and providing an adhesive layer on the surface of the layer. 12) The method for producing an adhesive tape according to claim 11, wherein the polymeric material is a polyvinyl chloride resin.