JPH01174542A - Sheet-or tape-like product - Google Patents

Abstract

PURPOSE:To provide a thin, bubble-contg. sheet-like product with the both surfaces carrying smooth and dense layers, useful as e.g. a substrate for adhesive tapes or sheets, consisting of a fine-bubble-contg. composition produced by mechanical agitation of a composition consisting mainly of a rubbery material emulsion. CONSTITUTION:A composition consisting mainly of a rubbery material emulsion is mechanically agitated followed by forming into a fine bubble-contg. composition as a sheet, thus obtaining the objective sheet- or tape-like product with the both surfaces carrying smooth and dense layers. Furthermore, this product has a group of bubbles of which those with a size of 10-50mum account for >=35% (pref. >=75%), and the 25% compression strength of 0.1-10kg/cm<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thin air-containing foam sheet or tape-like material having smooth and dense layers on the front and back surfaces.

More specifically, the purpose of the present invention is to provide a support for Wc-4 tape or sheet, and a sheet or tape-like article useful as a surgical material.

Conventional technology and its problems> Conventionally, foamed sheets made mainly of rubber and/or synthetic resins are formed by foaming and crosslinking using a pyrolyzable foaming agent, so most of the cells have a diameter of approximately It is as large as 100 to 500μ, and has a thickness of 40011% or more.

Double-sided adhesive tape, which is made by providing a pressure-sensitive adhesive layer on both sides of a foam sheet having such a thickness, has good cushioning properties and impact resistance, and is used for stator automobiles on plate-shaped objects such as mirrors. Used for securing moldings, etc.

However, if a double-sided adhesive tape made of a foam sheet having such a thickness is used for fixing as described above, a gap corresponding to the thickness of the foam sheet will be formed between the adherend and the material. In addition, there is a problem that not only is the appearance unfavorable due to the presence of dust, but also that the fixing function is degraded due to the deformability caused by the size of the bubble diameter.

On the other hand, a method has also been proposed in which a foam sheet with a thickness of 100 to 20 (1 μm) is made by slicing a foam sheet with a size of around 4 L)0 μm, but since the sliced surface becomes the sliced surface of the cell wall, the rough surface Question 1 (Problem! Means for Solving> The present invention provides a novel sheet or tape-like product that solves the problems of the prior art, and its gist is that a compound containing a rubber-like substance emulsion as a main component A microfoam-containing composition obtained by mechanically stirring the material is molded to have a smooth and dense 1fdk on the long surface, and
The inside has a bubble diameter of 10 to 50μ, which accounts for at least 35% of the air rtin, and the 25% compression strength is 0.1 to 1.
uK9/cIL”.

As is clear from the explanation given, the sheet or tape-like material of the present invention has a smooth and dense surface on the front and back surfaces.
When it has t-, the cell group tV with a cell diameter of 10 to 50μ inside accounts for at least 35%, preferably riso or more, more preferably 70% or more, and the 25% compressive strength is 0.1 to 1 oklI. /e4. Preferably 0.
A single-sided or double-sided adhesive tape is obtained by forming a known adhesive layer on the surface of the sheet or tape-like material by a conventional method.

It has excellent anchoring properties between the sheet or tape-like material and the adhesive 1-, and exhibits good retention properties. It is possible to provide an adhesive sheet or tape using a thin and strong foam sheet or tape as a support.

<Structure of the Invention> The compound mainly composed of a rubber-like substance emulsion used in the present invention contains rubbers and/or synthetic resins as the main components, a crosslinking agent, and a foaming agent as essential components. It may also contain compounding agents such as thickeners, pH adjusters, and gelling agents.

The individual materials constituting these compounds are generally commercially available, and the rubbers and/or synthetic resins include natural rubber, polyurethane rubber, silicone rubber, fluororubber, and chloroprene rubber. , nitrile rubber, acrylic rubber.

Styrene-butadiene rubber, styrene-isoprene-styrene copolymer, ethylene-propylene copolymer, monoolefinically unsaturated monomer and one or more other olefinically unsaturated monomers that can be copolymerized therewith. Copolymer of (
Examples include polymers or copolymers mainly composed of meth)acrylic acid esters, and these materials are made into emulsions with solid content t' adjusted to 30 to 70% by weight, preferably r145 to 65% by weight, according to a conventional method. Ru.

Examples of the cross-over agent include sulfur, melamine resins, epoxy resins, polyisocyanates, etc., and TIS is added in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the solid content of the emulsion.

Examples of foaming agents include surfactants such as anionic surfactants such as ammonium stearate, sodium lauryl sulfate, and potassium oleate, nonionic surfactants such as polyoxyethylene derivatives, and amphoteric surfactants such as lauryl betaine. These amounts are based on 100 parts by weight of the solid content of the emulsion.

It is blended in an amount of 0.1 to 15%i parts.

In addition, 2 thickeners include carboxylated ethyl acrylate, methylcellulose, sodium alginate, etc.
Gelling agents include polyethylene glycol, polymethyl vinyl ether, and sodium fluorosilicide, and PAAA agents include ammonia.

Caustic soda and the like are mentioned respectively.2 The total amount of these is 0.1 to 3 parts per 1001 parts of solid content of the emulsion.
It can be blended within the range of 0.

The microfoam-containing composition is at least 40% in the system.

Preferably 55% or more, more preferably 75% or more is 1
It is necessary that the bubble diameter be controlled to be within the range of 0 to 50μ, and the bubble diameter distribution is controlled by mixing the above-mentioned mixture with a mechanical stirrer such as an oak mixer or a high mixer at 500 to 3000r, P0m. .

It is obtained by mechanical stirring at a rotational speed of (at 20° C.) to a viscosity of 150 to 1000 poise (at 20° C.).

The microfoam-containing composition having the above distribution minimizes defoaming and has a suitable affinity with the composition, but by intentionally peeling it off, it can be peeled off without destroying the dense layer on one surface. It is applied to the liner in a thin layer of approximately 30 to 250 μm, and is preheated at a temperature of 100°C or less.
Then, heat at a temperature sufficient to harden the structure (100 to 200°C for 10
By performing the main heating for 0 to 500 seconds), a smooth dense layer is formed on the front and back surfaces, and the bubble diameter of 10 to 50 μm is at least 35%, preferably 50% or more, more preferably 70% or more: It has a 25% compressive strength of 0.1 to 10K97cd, preferably O,S to 6 kg/cm, due to the crosslinking operation. It is molded into a sheet or tape-like material containing microbubbles.

In the above, lθ~50μ in the sheet or tape-like material
When the proportion of bubbles having a diameter of 100 μm is less than 35% (therefore, the proportion of bubbles having a diameter of 50μ or more is 65% or more), it has excellent elasticity as a sheet or tape-like product, but Because the deformability increases due to the size of the bubbles...
This is undesirable because it reduces the retention properties, and the 25% compressive strength is 0.1 k! ? If it is less than /64, the recovery property after pressure Ia will be insufficient, and if it exceeds 10 kg/cm, the elastic performance will be poor and the conformability to the surface of the adherend will be reduced, which is not preferable.

In order to produce an adhesive sheet or tape using the sheet or tape-like material, it is peeled off from the #1 type liner and formed on one or both sides of the adhesive by a conventional method, but it is preferable to apply a liner. It is preferable to form an adhesive layer on the exposed surface of the sheet or tape-like material that is temporarily attached to the material. When forming an adhesive layer on both sides, if the 1 m of adhesive previously formed on the exposed surface is pressure-sensitive adhesive, release paper or something similar is temporarily attached to the surface of the layer, and then a single-sided adhesive sheet or The tape is preferably peeled off the liner and an adhesive layer is formed on the peeled surface.

The adhesive is a type that has pressure-sensitive adhesive properties at room temperature.

It can be used depending on the purpose, such as a type that exhibits adhesive properties by adding heat, water, a solvent, etc., and is non- or weakly adhesive at room temperature, a moisture-curing type, an anaerobic type, etc.
The thickness is also arbitrary, about 5 to 300 μm.

<Effects> The sheet or tape-like product of the present invention is formed of a smooth dense layer on the front and back surfaces, and the inside is formed with extremely fine air bubbles of 10 to 5 ops, and moreover, 4 of 2
Since it is a thin film with a compressive strength of 5%, it is convenient for use as a raw material for surgical materials, such as adhesive plasters, by taking advantage of its flexibility and strength.Furthermore, adhesive I- is provided on both sides of the film, so that it can be used as a raw material for surgical materials such as adhesive plasters. When used for fixing, it has the characteristic that excellent retention characteristics can be obtained because the air bubbles are fine and have little deformability.

<Example> Examples of the present invention are shown below. The middle part of the sentence means the position part.

Example 1 An acrylic copolymer emulsion with a solid content of 59% by weight was prepared by copolymerizing a blend of 28 parts of butyl acrylate, 63 parts of ethyl acrylate, and 9 parts of acrylonitrile using a conventional method. did.

15 parts of melamine resin, 71 parts of ammonium stearate, 2 parts of carboxylated ethyl acrylate, and 1 part of 25% ammonia water were mixed with 100 parts of the solid content of the emulsion, and the mixture was mixed in an oak mixer (1000 r, p, m).
At 20'C), the foaming ratio per press is approximately 2.5 times,
A microfoam-containing composition in which about 90% of the cells have a bubble diameter of 10 to 50 μm (viscosity of about 200 poise at 2°C)! Obtained.

Using a die coater, the composition was extrusion coated to a thickness of about 50 μm on the surface of a biaxially stretched polyester film treated to have low affinity, and pre-dried at 80° C. for 30 seconds.
After main drying at 50° C. for 180 seconds, a sheet-like material with a thickness of 50 μm was obtained.

The front and back surfaces of the obtained sheet-like material have smooth dense layers,
When observed with a cross-section 11ft TiA microscope, approximately 83% was 1
It was formed by a group of bubbles of 0 to 50 microns, and the rest were 50 microns or more, but the maximum did not exceed 150 microns.

Moreover, their number was small. The 25% compressive strength is approximately 4.
It was 5-4.7 kIP/cd.

In order to evaluate the characteristics of the cough sheet, on the exposed surface of the sheet with the polyester film still attached,
An acrylic pressure-sensitive adhesive made of acrylic acid-butyl acrylate copolymer and polyisocyanate is applied to a thickness of 60 μm, and a double-sided release paper based on kraft paper is pasted on this coated surface. First, the polyester film was peeled off and wound into a roll, and a pressure-sensitive adhesive was similarly applied to the surface of the sheet from which the polyester film had been peeled off, to produce a double-sided adhesive tape.

The adhesive strength of this tape to stainless steel plate is 1581/20mm
The shear holding force showed a value of 1 hour or more at a load of 5009 and 100 OJ.

Example 2 A double-sided adhesive tape was prepared in the same manner as in Example 1.

However, the thickness of the sheet-like material was t-200 μm. Its characteristics are that the adhesion force to stainless steel plate is 1870J//20+n
In both cases, the shear retention strength was less than 1 hour.

Example 3 Solid content 1 of the acrylic conformal emulsion of Example 1
00 parts by weight, 20 parts of melamine resin.

1 part of ammonium stearate, 1 part of carboxylated ethyl acrylate, and 1 part of 25% aqueous ammonia were mixed together and stirred in an oak mixer (1000r, P, mat at 20°C) at a foaming ratio of about 2 times, resulting in about 87% of the mixture. ILI~50μ
A microfoamed air-containing composition (viscosity: about 160 pores at 2 G°C) having a bubble diameter of 100 mL was obtained.

This composition was subjected to the same procedure as in Example 1 to obtain a sheet-like product having a thickness of 150 μm.

The long surface of the sheet material is smooth and dense 711WL, approximately 81%
was composed of a bubble diameter of 10 to 50μ grooves.

The 25% compressive strength was approximately 5.7-5.8 kC9/c4.

The adhesive strength of the double-sided adhesive tape prepared using the sheet-like material to the stainless steel plate was 1950.9/205 m, and the shear retention strength of both tapes was reached in 1 hour or more.

Comparative Example 1 Polyurethane foam sheet (thickness: 200μ) with sliced surfaces on both sides and an average cell diameter of 100 to 200μ
The acrylic pressure-sensitive adhesive of Example 1 was coated on both sides of 1.
A double-sided adhesive tape was made.

The adhesive strength of this tape to stainless steel plate is 1O80y/2G
'ls,! The four-break holding force was over 1 hour at a load of 500.9, but was 0.4 hours at a load of 1000p.

Comparative Example 2 A double-sided adhesive tape was prepared by applying the acrylic pressure-sensitive adhesive of Example 1 to both sides of a rayon nonwoven fabric with a thickness of 40 μm.

The adhesive strength of this tape to stainless steel plate is 13009/20
Regarding this, the shear holding force was more than 1 hour at a load of 500y, but it failed in 0.4 hours at a load of ioooog.

Characteristic evaluation methods for Examples and Comparative Examples are as follows.

Prepare two stainless steel plates with a width of 20B and a yellowness of 100m.
A test piece is prepared by pasting a sample of silk X20 and pasting the end of the other stainless steel plate onto -iM so that the stainless steel plates are not directly aligned with each other. 25℃×6
The adhesive force is measured by pulling the stainless steel plate in the opposite direction at a speed of 3 U Oxx/min in an atmosphere of 5% R,H.

Prepare a Bakelite plate with a shear holding width of 20 mm and a length of 100 inches, and an aluminum plate.A sample with a length of 20 mm and a length of 1 OB is pasted on the end of the Bakelite plate, and the edge of the aluminum plate is attached to the sample surface. A test specimen is prepared by pasting the two pieces in a straight line so that they do not overlap.The Bakelite plate is fixed, a load of 1 liter is applied to the aluminum plate, and the time taken for the load to fall is measured.

25% compressive strength: compress the sample (2511×25#!l) at a rate of 5 steps/min until it reaches 374, and characterize the stress at that time.

Claims (1)

[Claims] 1) Molded from a microfoam-containing composition obtained by mechanically stirring a compound containing a rubber-like substance emulsion as a main component, it has smooth dense layers on the front and back surfaces, and has a 10 to 50 micron layer inside.
having a group of bubbles in which the bubble diameter of m accounts for at least 35%;
A sheet or tape-like article having a 25% compressive strength of 0.1 to 10 kg/cm.