JPH1114337A - Adhesive member and thickness measuring method of superimposed adhesive layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive member and a thickness measuring method therefor by which a thickness of an objective adhesive layer can be easily, quickly and accurately known when a superimposed adhesive layer has an approximate chemical structure and the composition, even when there is only a difference in a cross-linking degree, and even when being in a forming process on a manufacturing line on a thickness of respective layers or its prescribed layer of the adhesive layer to form a superimposed adhesive layer. SOLUTION: A adhesive member has on a support base material 20 a superimposed adhesive layer 1 composed of a superimposed close contact layer of adhesive layers 11 and 12 not less than two layers, and at least a single layer of the adhesive layers 11 and 12 to form its superimposed adhesive layer 1, contains a small quantity of spectrochemical analysis detecting materials. In a thickness measuring method of the superimposed adhesive layer, one kind or two or more kinds of spectrochemical analysis detecting materials contained in the adhesive layers 11 and 12 to form the superimposed adhesive layer 1 in its adhesive member, are quantitatively determined by a spectrochemical analysis, and are converted into a thickness of the adhesive layers 11 and 12 containing its prescribed spectrochemical analysis detecting materials. Therefore, thickness of plural adhesive layers are also simultaneously measured in a noncontact condition, and a qualitatively stable adhesive member can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive member which enables the thickness of a predetermined pressure-sensitive adhesive layer for forming a superposed pressure-sensitive adhesive layer to be determined simply and quickly at an appropriate stage such as a manufacturing process, and an accurate pressure-sensitive adhesive layer. It relates to a thickness measurement method.

[0002]

BACKGROUND OF THE INVENTION Adhesive members comprising a support substrate, which may be a separator, provided with an adhesive layer, such as a packaging material, an electric insulating tape, a masking tape, a surface protective material, a temporary fixing material and a fixing material for parts, and the like. With the expansion and evolution of the field of use, the required performance has been advanced, and in order to meet the demand, a device in which a superposed pressure-sensitive adhesive layer composed of pressure-sensitive adhesive layers having different physical properties is provided on a supporting substrate has been proposed. By the way, in packaging materials used for sealing work of cardboard boxes, etc., it is difficult to peel off even by low pressure bonding, and it is necessary to be able to use it in a wide temperature range such as summer and winter Adhesive members have been proposed.

In general, in the above-mentioned superposed pressure-sensitive adhesive layers, the thickness of each superposed pressure-sensitive adhesive layer tends to affect the overall properties, and the thickness of each pressure-sensitive adhesive layer is often made thin in terms of controlling properties. . Therefore, control of the thickness of the adhesive layer is more important than ever before in stabilizing characteristics and quality. The thickness of each pressure-sensitive adhesive layer forming the superposed pressure-sensitive adhesive layer can be known by cross-sectional observation with an optical microscope or the like, but the work requires many hours and labor and is not easy and quick. There is a problem that is difficult to apply to the measurement of the thickness of a certain adhesive layer.

Further, it is difficult to measure the thickness of a specific layer of the adhesive layer forming the superposed adhesive layer with a physical measuring instrument such as a dial gauge, and it is difficult to measure the thickness of the spectroscopic optical device through infrared rays or ultraviolet rays. When the chemical structures and compositions of the pressure-sensitive adhesive layers are similar or when the difference between the superposed pressure-sensitive adhesive layers is merely the degree of crosslinking, it is difficult to discriminate the difference between the layers, and the reliability of the thickness measurement is poor.

[0005]

The present invention relates to a method for determining the thickness of each of the adhesive layers forming a superposed pressure-sensitive adhesive layer or a predetermined layer thereof, in the case where the superposed pressure-sensitive adhesive layers have similar chemical structures or compositions, or simply by the difference in the degree of crosslinking. In the case of, etc., and also in the case of being in the process of forming on the production line, the development of an adhesive member that can easily and quickly and accurately know the thickness of the target adhesive layer, and a method of measuring the thickness of the adhesive member. Make it an issue.

[0006]

According to the present invention, a superposed pressure-sensitive adhesive layer comprising a superposed adhesion layer of two or more pressure-sensitive adhesive layers is provided on a supporting substrate.
An adhesive member, wherein at least one of the adhesive layers forming the superposed adhesive layer contains a small amount of a spectroscopic detection substance, and one or more of the adhesive layers contained in the adhesive layer forming the superposed adhesive layer in the adhesive member. A method for measuring the thickness of a superposed pressure-sensitive adhesive layer, comprising quantifying two or more kinds of spectroscopically detected substances by spectroscopic analysis and converting them into a thickness of a pressure-sensitive adhesive layer containing the predetermined spectroscopically detected substance. It is.

[0007]

According to the pressure-sensitive adhesive member of the present invention, one or more kinds of spectroscopic detection substances containing a small amount of one or more of the pressure-sensitive adhesive layers forming the superposed pressure-sensitive adhesive layer in different combinations are contained. Each type can be quantified via spectroscopic analysis, and since the quantified value is proportional to the thickness of the adhesive layer containing the specified spectroscopic detection substance and its content concentration, the purpose is to correct the quantification based on the content concentration Can be known.

Therefore, as described above, two or more or all of the pressure-sensitive adhesive layers forming the superposed pressure-sensitive adhesive layer are detected for each type of spectroscopic detection substance contained in different combinations, and the predetermined detection substance is contained. The thickness of each pressure-sensitive adhesive layer can be known at the same time, and when only one of the pressure-sensitive adhesive layers contains a spectroscopic detection substance, the thickness of the specific pressure-sensitive adhesive layer can be known. Moreover, based on the spectroscopic detection substance, even when the superposed adhesive layers are chemically or compositionally the same or similar in points other than the spectroscopic detection substance, or when they differ only in the degree of cross-linking, etc. In addition, even in the case of an adhesive layer that is being formed on a production line, the thickness of the target adhesive layer can be known easily, quickly, accurately, and in a non-contact manner, and the quality is stable. Thus, a pressure-sensitive adhesive member can be obtained. In addition, since the amount of the spectroscopic detection substance added is small, it does not substantially affect the adhesive properties.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The pressure-sensitive adhesive member of the present invention has a superposed pressure-sensitive adhesive layer comprising a superposed adhesion layer of two or more pressure-sensitive adhesive layers on a support substrate, and at least one of the pressure-sensitive adhesive layers forming the superposed pressure-sensitive adhesive layer. One layer contains a small amount of a spectroscopic detection substance so that the thickness of the adhesive layer containing the detection substance can be known by spectroscopic analysis. An example is shown in FIG. 1 is a superposed pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layers 11 and 12 are superimposed and adhered, 2 is a support base material, and 21 is a release coat layer provided as needed.

In the present invention, the superposed pressure-sensitive adhesive layer has two layers or three layers.
It is formed as a superimposed adhesion layer of an adhesive layer having at least two layers. An appropriate pressure-sensitive adhesive can be used for forming the pressure-sensitive adhesive layer, and the type thereof is not particularly limited. Incidentally, examples thereof include various adhesives such as rubber-based, acrylic-based, silicone-based and urethane-based, vinyl alkyl ether-based and polyvinyl alcohol-based, polyvinylpyrrolidone-based, polyacrylamide-based, and cellulose-based adhesives.

The superposed pressure-sensitive adhesive layer may be a layer in which the same pressure-sensitive adhesive layer is superposed for the purpose of controlling the thickness, etc., but is generally a combination of pressure-sensitive adhesive layers having different physical properties between the upper and lower layers for the purpose of improving performance and the like. It is assumed that they are superimposed. Therefore, when three or more adhesive layers are overlapped, the same adhesive layer may be overlapped via adhesive layers having different physical properties. There is no particular limitation on the above-mentioned different physical properties. Incidentally, examples include adhesive properties such as adhesive strength and cohesive strength, dynamic elastic modulus and stress relaxation time, degree of crosslinking and heat resistance, solvent resistance and water resistance, and decrease in adhesive strength due to the presence or absence of a foaming agent. And curability by radiation, heat and the like.

Therefore, the pressure-sensitive adhesive layer in the superposed pressure-sensitive adhesive layer can be formed by using the same or different pressure-sensitive adhesives in an appropriate combination. The physical properties of the pressure-sensitive adhesive layer may be determined, for example, by the type of the base polymer, the type of the additive or the type or amount of the appropriate additive such as a resin or a tackifier, a plasticizer or a softener, a foaming agent or a filler. Can be controlled by an appropriate method such as an internal cross-linking method by copolymerization of a polyfunctional monomer, an external cross-linking method by compounding a cross-linking agent, a method by a cross-linking composition such as a radiation cross-linking method by a photopolymerization initiator, Any of the well-known physical property control methods can be adopted.

The pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive in the form of a solution of an organic solvent, a dispersion or emulsion of water, or a mixture of monomer components, etc. onto a supporting substrate, followed by heat drying or radiation irradiation. Alternatively, it can be formed by an appropriate method according to the related art, such as a method of transferring an adhesive layer formed on a separator onto a supporting substrate.
Therefore, the superposed pressure-sensitive adhesive layer can also be formed by an appropriate method such as a method of applying the pressure-sensitive adhesive or drying the pressure-sensitive adhesive layer by coating and drying, or a transfer and superposition method. From the viewpoint of the adhesion between the layers and the like, it is preferable to use a superposition method in a wet state by a recoating method or the like.

In the present invention, the superposed adhesive layer provided on the support substrate is such that at least one of the two or more adhesive layers forming the same contains a spectroscopic detection substance. Therefore, the pressure-sensitive adhesive layer containing the spectroscopic detection substance may be two or more or all of the pressure-sensitive adhesive layers forming the superposed pressure-sensitive adhesive layer. That is, the spectroscopic detection substance can be contained in one or more of the adhesive layers for the purpose of thickness measurement. When the detection substance is contained in two or more adhesive layers, each adhesive layer contains a different spectroscopic detection substance. Thereby, each layer of the adhesive layer can be distinguished based on the type of the spectroscopic detection substance.

As the spectroscopic detection substance, for example, fluorescent X
X-ray spectrometer (XRF), plasma emission spectrometer (ICP), energy dispersive spectrometer (SEM-E)
An appropriate substance that can be detected by spectroscopic analysis using an appropriate spectroscopic analyzer such as DX) can be used. Generally, compounds containing heavy elements of fluorine or more, especially sodium or more, which can be trace-analyzed by a fluorescent X-ray spectrometer or the like, particularly Al and Ca,
A metal such as Zn or Ti, a metal salt or a metal compound thereof can be preferably used as a spectroscopic detection substance.

Although the spectroscopic detection substance may be an inorganic compound, from the viewpoint of the compoundability to the adhesive layer and the prevention of the influence on the adhesive properties, for example, ethyl acetoacetate aluminum diisopropylate or zinc acetate is used. Those in the state of an organic metal compound such as a metal chelate compound and a metal salt of an organic acid can be preferably used.

The spectroscopic detection substance can be contained in the pressure-sensitive adhesive layer by being mixed with the above-mentioned coating solution for forming the pressure-sensitive adhesive layer. The amount may be small. Generally, from the viewpoint of the detection accuracy of the spectroscopic analyzer and the prevention of the influence on the adhesive properties, the content of the detection element in the adhesive layer is set at 2%.
The amount is from 5 to 5% by weight, preferably from 10 to 3% by weight, especially from 0.01 to 1% by weight.

The thickness of each adhesive layer forming the superposed adhesive layer is as follows:
It can be appropriately determined according to the purpose of use and the like, and is not particularly limited.
It can be thicker than 1 mm, but generally 50
It is 0 μm or less, especially 1 to 300 μm, especially 3 to 200 μm.

Depending on the purpose of use, the support substrate of the superposed pressure-sensitive adhesive layer may be, for example, a porous substrate made of paper, cloth or nonwoven fabric, a plastic film or sheet, a foam, a metal foil, or the like.
Appropriate thin leaf bodies such as laminates thereof may be used. Also, as for the materials, for example, kraft paper and Japanese paper, cotton and soup, rayon and vinylon, polyester and polyamide, OPP and polyvinyl chloride, polyurethane and acrylic resin, polyolefin such as cellophane and polyethylene, natural rubber and synthetic rubber, aluminum and stainless steel For example, an appropriate substance that is not confused with the spectroscopic detection substance blended in the adhesive layer can be used.

The support substrate may be subjected to a known surface treatment such as a coating treatment with a primer or the like, a corona discharge treatment or a plasma treatment for the purpose of improving the adhesion to the adhesive layer.
Further, on the back surface of the supporting base material, if necessary, a release coat layer made of an appropriate release agent such as a silicone-based or long-chain alkyl-based release agent may be provided to obtain a wound adhesive member that can be easily unwound. .

Further, an adhesive member in which the overlapping adhesive layer is supported by a separator made of a supporting substrate provided with the release coat layer and only the overlapping adhesive layer can be adhered to an adherend, or both surfaces of the supporting substrate A pressure-sensitive adhesive member having the same or different type of superimposed pressure-sensitive adhesive layer, or having a superposed pressure-sensitive adhesive layer on one surface of a support base material,
An adhesive member having a single-layer adhesive layer on the other surface can also be used. The adhesive member can be put to practical use in an appropriate form such as a narrow tape form or a wide sheet form. In the case of an adhesive member whose adhesive layer is exposed on the surface, it is preferable to protect the adhesive layer with a separator until the adhesive layer is put to practical use.

The thickness of the pressure-sensitive adhesive layer containing the spectroscopic detection substance forming the superposed pressure-sensitive adhesive layer in the pressure-sensitive adhesive member according to the present invention is measured, for example, from an appropriate side of the front and back of the pressure-sensitive adhesive member through a spectroscopic analyzer.
Spectroscopic analysis and quantification of one or more spectroscopic detection substances contained in one or more adhesive layers, and spectroscopic detection contained in the adhesive layer based on the quantitative value of each spectroscopic detection substance It can be performed by correcting the quantitative amount based on the substance concentration and converting it to the thickness of the adhesive layer containing a predetermined spectroscopic detection substance. The correction can be performed, for example, by previously measuring the quantitative value of the reference thickness of the adhesive layer containing a predetermined concentration of the spectroscopic detection substance,
The conversion of the quantitative value into the thickness of the adhesive layer can be performed by a method of preparing a calibration curve from the correction quantitative values and comparing the calibration curve with the calibration curve.

[0023]

【Example】

Reference Example 1 160 parts of ethyl acrylate (parts by weight, the same applies hereinafter), 40 parts of 2-ethylhexyl acrylate, and 10 parts of hydroxyethyl acrylate were placed at 60 ° C. in 200 parts of toluene containing 0.4 parts of benzoyl peroxide. 1 part of trimethylolpropane tolylene diisocyanate adduct per 100 parts of the acrylic polymer was added to a solution containing an acrylic polymer having a weight average molecular weight of 600,000 obtained by polymerization treatment for 10 hours. The adhesive was applied on the separator and dried at 100 ° C. for 5 minutes to form an adhesive layer having a thickness of 10 μm.

Reference Example 2 An adhesive layer was formed in the same manner as in Reference Example 1 except that an adhesive was used in which the addition amount of trimethylolpropane tolylene diisocyanate was 0.5 part.

Reference Example 3 An adhesive layer having a thickness of 7 μm was formed in the same manner as in Reference Example 2 except that an adhesive containing 1 part of ethyl acetoacetate aluminum diisopropylate was additionally used.

Reference Example 4 An adhesive layer was formed in the same manner as in Reference Example 2 except that an adhesive additionally containing 1 part of ethyl acetoacetate aluminum diisopropylate was used.

REFERENCE EXAMPLE 5 Reference example except that a pressure-sensitive adhesive having an addition amount of trimethylolpropane tolylene diisocyanate of 0.2 part was used and coated on an OPP (polypropylene) film having a thickness of 40 μm. An adhesive sheet was obtained by forming an adhesive layer according to 1.

Example 1 The pressure-sensitive adhesive layer obtained in Reference Example 3 was transferred onto the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained in Reference Example 5 via a heating laminator at 100 ° C. to form a superposed pressure-sensitive adhesive layer having a different degree of crosslinking. A pressure-sensitive adhesive member was obtained.

Example 2 An adhesive member having an overlapping adhesive layer having a different degree of crosslinking was obtained in the same manner as in Example 1 except that the adhesive layer obtained in Reference Example 4 was transferred instead of the adhesive layer of Reference Example 3. .

Example 3 An adhesive member having a superposed adhesive layer having a different degree of crosslinking was obtained in the same manner as in Example 1 except that the adhesive layer obtained in Reference Example 1 was transferred onto the adhesive layer of Reference Example 3. .

Example 4 An adhesive member having a superposed adhesive layer having a different degree of crosslinking was obtained in the same manner as in Example 2 except that the adhesive layer obtained in Reference Example 1 was transferred onto the adhesive layer of Reference Example 4. .

Comparative Example 1 An adhesive member having a superposed adhesive layer having a different degree of crosslinking was obtained in the same manner as in Example 2 except that the adhesive layer obtained in Reference Example 2 was transferred instead of the adhesive layer of Reference Example 4. .

Comparative Example 2 An adhesive member having a superposed adhesive layer having a different degree of crosslinking was obtained in the same manner as in Comparative Example 1 except that the adhesive layer obtained in Reference Example 1 was transferred onto the adhesive layer of Reference Example 2. .

Evaluation Test The thickness of the second adhesive layer (ethylacetoacetate aluminum diisopropylate-containing layer or a layer equivalent thereto) from the polypropylene film side of the superposed adhesive layers of the adhesive members obtained in Examples and Comparative Examples was measured. Investigation was performed by the following method.

X-Ray Fluorescence Thickness The pressure-sensitive adhesive member was formed into a circular shape having a diameter of 3 cm with the polypropylene film side facing inward.
The content was quantified, and the thickness of the adhesive layer was converted from the quantified value using a calibration curve prepared in advance.

Microscopic Thickness The pressure-sensitive adhesive member was cut by a freezing microtome method, and the cross section was observed through an optical microscope to determine the desired thickness of the pressure-sensitive adhesive layer.

Dial Gauge Thickness The desired adhesive layer thickness was examined using a dial gauge.

Convenience In the above, the simplicity of the thickness measurement operation was evaluated as "O" when the pressure-sensitive adhesive member could be subjected to a thickness measurement test without any pretreatment, and "X" when there was no pretreatment.

Quickness In the above, the speed of the thickness measurement operation was evaluated as ○ when the time required for obtaining the result including sampling of the adhesive member was within 1 minute, and × when more than 1 minute.

The results are shown in the following table.

From the table, it can be seen that the pressure-sensitive adhesive member according to the present invention can accurately, simply and quickly measure the thickness of a specific pressure-sensitive adhesive layer in the superposed pressure-sensitive adhesive layer.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment.

[Explanation of symbols]

 1: superimposed adhesive layer 11, 12: adhesive layer 2: support base material 21: release coat layer

Claims (5)

[Claims] 1. A superposed pressure-sensitive adhesive layer comprising a superposed adhesion layer of two or more pressure-sensitive adhesive layers on a supporting substrate, wherein at least one of the pressure-sensitive adhesive layers forming the superposed pressure-sensitive adhesive layer has a small amount of spectroscopic detection. An adhesive member containing a substance. 2. The adhesive layer according to claim 1, wherein the adhesive layer forming the superposed adhesive layer has different physical properties between the upper and lower layers, and the spectroscopic detection substance is a compound containing a heavy element of fluorine or more. Adhesive members that are possible. 3. The adhesive member according to claim 1, wherein the spectroscopic detection substance is an organometallic compound. 4. The pressure-sensitive adhesive member according to claim 1, wherein two or more or all of the pressure-sensitive adhesive layers forming the superposed pressure-sensitive adhesive layer contain different spectral analysis detection substances. 5. A spectroscopic analysis of one or two or more kinds of spectroscopic detection substances contained in the adhesive layer forming the superposed adhesive layer in the adhesive member according to claim 1, and the predetermined spectroscopy thereof. A method for measuring the thickness of a superposed pressure-sensitive adhesive layer, wherein the thickness is converted into the thickness of the pressure-sensitive adhesive layer containing an analytical detection substance.