JPH07178035A - Dustproof mat - Google Patents

Abstract

PURPOSE:To prevent the generation of static electricity in the removing operation of a spent adhesive sheet, so as to smooth the removing operation. CONSTITUTION:In this dustproof mat 4 made by laminating plural adhesive sheet (1A to 1F) which are adhesive sheets 1 each having a weak adhesive layer 3 on one side surface of holder 2, by fringing the holder 2 and the weak adhesive layer 3 into contact between neighboring sheets 1 and 1, the weak adhesive layers are formed with a composition containing a copolymer of 30 to 70wt.% of a methoxyethylacrylate, 30 to 70wt.% of caprolactoneacrylate, and 40 to 0wt.% of the other monomer which is copolymerizable with them as the base polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dustproof mat used in a place where a dust-free environment is desired, such as a hospital, an electronic component manufacturing factory, a semiconductor manufacturing factory.

[0002]

2. Description of the Related Art In a place where a dust-free environment is desired, such as a hospital, an electronic parts manufacturing factory, or a semiconductor manufacturing factory, a weak adhesive layer is generally used to remove dust and dirt adhering to the shoes of people who come and go. It uses the provided dustproof mat. Various kinds of dustproof mats are known, but as a typical one, two or more adhesive sheets having a weak adhesive layer based on acrylic rubber on one side of a support are provided. There is a laminate in which the support and the weak adhesive layer are in contact with each other between adjacent sheets.

The dustproof mat of this laminated structure peels off the adhesive sheet when the adhesive force of (the weak adhesive layer of) the uppermost adhesive sheet is not dust or dust. In this method, each (adhesive layer) of the lower adhesive sheet is newly exposed, and each adhesive force of the laminated adhesive sheets is sequentially used.

[0004]

However, the conventional dust-proof mat of this type is apt to generate static electricity when peeling off the used adhesive sheet, which impairs the peeling work and is not suitable for the operator. It gave a pleasant feeling, and there was a problem in terms of practicality.

In view of the above circumstances, the present invention prevents generation of static electricity when peeling off a used adhesive sheet,
It is an object of the present invention to provide a dustproof mat which is excellent in practicality and can be smoothly peeled off.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above-mentioned object, and as a result, when the weak adhesive layer of the adhesive sheet was made of a specific base polymer, As a result, they have found that static electricity can be prevented from being generated during the peeling operation, and have completed the present invention.

That is, according to the present invention, two or more adhesive sheets having a weak adhesive layer on one surface of a support are laminated so that the support and the weak adhesive layer are in contact with each other between adjacent sheets. In the dustproof mat, the above-mentioned weak adhesive layer comprises 30 to 70% by weight of methoxyethyl acrylate, 30 to 70% by weight of caprolactone acrylate, and 40 to 0% by weight of another monomer copolymerizable therewith. The present invention relates to a dustproof mat, characterized in that it contains a copolymerized polymer with as a base polymer.

As described above, in the present invention, a specific copolymerized polymer containing methoxyethyl acrylate and caprolactone acrylate as essential components is provided in the weak adhesive layer of the adhesive sheet constituting the dustproof mat. By using a base polymer as a base polymer, a weak adhesive layer having a low electric insulation, that is, a high electric conductivity is obtained due to the high polarity based on the copolymerization polymer, which is a sheet. It was found that it greatly contributes to the prevention of the generation of static electricity at the time of peeling.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The dustproof mat of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the structure of the dustproof mat of the present invention.

In FIG. 1, reference numeral 1 denotes an adhesive sheet having a weak adhesive layer 3 provided on one surface of a support 2, and 6 of the adhesive sheet is provided.
The dustproof mat 4 is formed by laminating the sheets (1A to 1F) so that the support 2 and the weak adhesive layer 3 are in contact with each other between adjacent sheets.

As the support 2, a plastic film having a thickness of about 40 to 100 μm made of polyethylene film or the like is used, and the thickness of the weak adhesive layer 3 provided on one surface of the support 2 is about 5 to 20 μm. . The number of stacked adhesive sheets 1 is not limited to the illustrated six, and may be two or more. The total thickness of the dust-proof mat 4 after lamination is usually 30
It is desirable that the thickness is about 0 to 600 μm.

The weak adhesive layer 3 is methoxyethyl acrylate.
It is formed by applying a pressure-sensitive adhesive containing a copolymerized polymer containing a copolymer and a caprolactone acrylate as an essential monomer component to one surface of the support 2 and drying it. In the pressure-sensitive adhesive, in addition to the above copolymerized polymer as a base polymer, various additives such as a crosslinking agent, a tackifier, a surfactant, a colorant, a filler, and an antioxidant are added. be able to.

The adhesive property of the weak adhesive layer 3 must be such that it can remove dust and dirt adhering to shoes well and that it exhibits a weak adhesive force that does not hinder walking. The monomer structure of the copolymerization polymer and the type and amount of the crosslinking agent and other additives are appropriately determined so as to obtain sufficient adhesive strength. As a guide, the 180 degree peel adhesive strength at room temperature for stainless steel plates is 30-
It is recommended that the width be adjusted to about 800 g / 20 mm.

Further, since it is necessary to sequentially peel off the used adhesive sheet 1, the adhesive force between the support 2 and the weak adhesive layer 3 between the adjacent sheets (for example, sheet 1A in FIG. 1). It is desirable that the adhesive force between the support 2 and the weak adhesive layer 3 of the sheet 1B), that is, the self-back adhesive force, be set to an appropriate value. In general, it is preferable that the 180 ° peeling adhesive strength at room temperature to the back surface of the self is about 20 to 500 g / 50 mm width.

In the copolymerized polymer used as the base polymer of the adhesive, methoxyethyl acrylate is used as one of the essential components of the constituent monomer. This monomer has the following formula: The glass transition temperature of the homopolymer represented by
The temperature is below ℃, and it effectively functions as a monomer that gives adhesive strength.

As another essential component of the constituent monomer, caprolactone acrylate is used.
This monomer has the following formula: Where m is 1 to 10 in the general formula.
And the average value of m is in the range of 1 to 5. This type of monomer is a polymerizable carbon-
It is said that the distance between the carbon double bond and the carboxyl group is large, and that when this is subjected to addition polymerization, the carboxyl group bonded as a side chain to the polymerization main chain exists at a position distant from the main chain. The polymer has a low glass transition temperature in order to have a unique molecular structure.

Further, as a monomer other than these, a monomer copolymerizable with the above-mentioned both monomers can be used if necessary for adjusting the adhesive force, cohesive force and the like.
Specifically, (meth) acrylic acid, a monomer containing a carboxyl group such as maleic acid, and the number of carbon atoms of the alkyl group are 1 to
12 (meth) acrylic acid alkyl ester, (meth)
A hydroxyl group-containing monomer such as 2-hydroxyethyl acrylate, vinyl acetate, vinyl propionate, styrene or a derivative thereof (for example, sodium styrenesulfonate), (meth) acrylonitrile and the like can be mentioned.

The proportion of these monomers used is all monomers.
30-70% by weight of methoxyethyl acrylate
(Preferably 40 to 60% by weight), caprolactone acrylate is 30 to 70% by weight (preferably 35 to 55% by weight), and another monomer copolymerizable with these is 40 to 0%.
The content should be in the range of 50% by weight (preferably 25 to 5% by weight), and if it is out of these ranges, it should be satisfied in terms of performance such as weak adhesive force, self-backside adhesive force, electric conductivity and hydrophilicity. No results are obtained.

The copolymerized polymer can be obtained by copolymerizing the above-mentioned monomer by an appropriate radical polymerization method such as a bulk polymerization method, a solution polymerization method, an emulsion polymerization method or a suspension polymerization method. . As the polymerization initiator,
Azobisisobutyronitrile, azo compounds such as azobisvaleronitrile, benzoyl peroxide, peroxides such as lauroyl peroxide, ammonium persulfate, persulfates such as potassium persulfate, sodium bisulfite and sodium ascorbate, A redox catalyst with a metal salt is used.

This copolymer has a glass transition temperature of usually 0 ° C or lower, preferably about -10 ° C to -70 ° C, which contributes to the development of adhesive strength and is contained in the molecule. It exhibits good electrical conductivity due to polar groups such as carboxyl groups, and also has excellent hydrophilicity, and also has the function of imparting water-soluble, water-dispersible or water-swellable properties to the adhesive. There is.

Dustproof mat 4 made of such constituent materials
In a place such as a hospital, an electronic parts manufacturing factory, or a semiconductor manufacturing factory, the adhesive surface is on the floor surface directly or through an underlay sheet, that is, the adhesive layer of the uppermost layer in FIG. Placed and fixed so that the weak adhesive layer 3 of 1A is exposed on the surface. This effectively adheres and removes dust and dirt attached to the soles of pedestrians.

When the adhesiveness of the adhesive sheet 1A is lost due to the adhesion and removal, the used adhesive sheet is peeled off to expose the adhesive sheet 1B of the lower layer. For example, the same dustproof performance as described above can be exhibited, and this peeling operation can be repeated up to the lowest adhesive sheet 1F. Here, in such a peeling operation, there is no fear of generating static electricity as in the conventional case, the peeling operation of each sheet can be performed smoothly, and the operator is not uncomfortable.

[0023]

As described above, according to the present invention, static electricity is not generated during the peeling operation of the adhesive sheet, the peeling operation is smooth, and there is no fear of causing discomfort to the operator. Therefore, it is possible to provide a dust-proof mat having a high practical value in a place where a dust-free environment is desired, such as a hospital, an electronic component manufacturing factory, or a semiconductor manufacturing factory.

Further, in this dustproof mat, the above-mentioned copolymer forming the weak adhesive layer of the adhesive sheet has good hydrophilicity and has a property of being soluble, dispersible or swellable in water. Therefore, the used adhesive sheet can be easily cleaned and recovered, and even if a part of the weak adhesive layer may be transferred to the sole, Therefore, it has advantages such as easy cleaning and removal.

[0025]

EXAMPLES Next, examples of the present invention will be described to explain more specifically. In the following, "parts" means "parts by weight".

Example 1 In a 1-liter three-necked flask, 55 parts of methoxyethyl acrylate and caprolactone acrylate [trade name "Aronix M-5300" manufactured by Toagosei Co., Ltd .; m = 1 to 5 (average value = about 1.8)] 40
Parts, acrylic acid 5 parts, potassium hydroxide 8.8 parts, water 96
Parts, 144 parts of methanol and 0.175 parts of azobisisobutyronitrile were added and mixed, and the polymerization reaction was carried out at 60 ° C. for 5 hours while replacing the inside of the flask with nitrogen.

In a solution of the copolymerized polymer thus obtained, 100 parts of the copolymerized polymer was added to a cross-linking agent [trade name "EX-830" manufactured by Nagase Chemical Co .; Diglycidyl ether of polyethylene glycol] 0.
3 parts and a surfactant [trade name "T- manufactured by Sanyo Kasei Co., Ltd.
20C "; polyoxyethylene sorbitan fatty acid ester] was mixed and uniformly mixed to obtain a pressure-sensitive adhesive composition.

Next, this pressure-sensitive adhesive composition was prepared to have a thickness of 60.
An adhesive sheet was formed by coating one surface of a polyethylene film having a thickness of 10 μm so that the thickness of the weak adhesive layer after drying would be 10 μm and drying. After that, 6 this adhesive sheet
One sheet was prepared and laminated as shown in FIG. 1 to prepare a dustproof mat.

Example 2 Polymerization raw materials were prepared by using 55 parts of methoxyethyl acrylate and 40 parts of caprolactone acrylate (the same as in Example 1).
Part, sodium styrenesulfonate 5 parts, potassium hydroxide 8.8 parts, water 96 parts, methanol 144 parts, azobisisobutyronitrile 0.175 parts except that the polymerization reaction was performed in the same manner as in Example 1. I went.

To the solution of the copolymerized polymer thus obtained, the same cross-linking agent and surfactant as in Example 1 were blended in the same amounts as in Example 1 to prepare a pressure-sensitive adhesive composition, which was used. An adhesive sheet was formed in the same manner as in Example 1. Further, six pieces of this adhesive sheet were prepared and laminated as shown in FIG. 1 to prepare a dustproof mat.

Comparative Example 1 A weight ratio of n-butyl acrylate and acrylic acid of 95: 5.
To a solution of the copolymerized polymer of 1), 100 parts of the copolymerized polymer, 5 parts of an isocyanate type cross-linking agent and 0.3 part of a phosphoric acid ester type surfactant were mixed to prepare an adhesive composition,
Using this, an adhesive sheet was formed in the same manner as in Example 1. Further, six pieces of this adhesive sheet were prepared and laminated as shown in FIG. 1 to prepare a dustproof mat.

For each of the dustproof mats of Examples 1 and 2 and Comparative Example 1 described above, the adhesive strength of the self-backing adhesive sheet, the adhesive strength to the stainless steel plate, and the amount of static electricity during the peeling operation were determined according to the following methods. Was measured and its performance was evaluated. The results of these tests are as shown in Table 1 below.

<Measurement of self-adhesive strength> 50 dustproof mats
After cutting to a width of mm, the uppermost pressure-sensitive adhesive sheet was peeled off, and the force at this time was measured at a pulling speed of 300 mm / min and a peeling angle of 180 ° with a shocker type tensile tester.

<Measurement of adhesive strength to stainless steel plate>
The adhesive sheet before making the dustproof mat was cut into a size of 20 mm in width and 150 mm in length to prepare a test piece. In addition, 27 kinds of SUS 2 specified in JIS G 4305
7CP steel plate is cut into a thickness of 2 mm, a width of 50 mm and a length of 125 mm, and the surface thereof is specified in JIS R 6253 2.
A No. 80 water resistant abrasive paper that was well polished was used as an adherend.

The above test piece was attached to the above surface of this adherend with one reciprocation of a 2 kg rubber roller, left for about 30 minutes, and then pulled at a pulling rate of 300 mm / min and a peeling angle of 180 degrees. The adhesive strength was measured with a shocker type tensile tester. Both the bonding and the measurement were performed in an atmosphere of a temperature of 23 ° C. and a relative humidity of 65%.

<Measurement of static electricity amount> 20 cm dust-proof mat
After cutting it to a size of 30 cm, the uppermost adhesive sheet
The test piece was peeled off, and the static electricity amount at this time was measured by a static electricity amount measuring device [trade name “KS471” manufactured by Kasuga Electric Co., Ltd.].

[0037]

[Table 1]

As is clear from the results shown in Table 1, in the dustproof mat of the present invention, the adhesive sheet to be laminated has an adhesive force suitable for the purpose of use, and at the time of peeling operation, static electricity is not generated. It can be seen that it does not occur at all and has excellent performance as a dustproof mat used in hospitals and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing one structural example of a dustproof mat of the present invention.

[Explanation of symbols]

 1 (1A to 1F) Adhesive sheet 2 Support 3 Weak adhesive layer 4 Dust-proof mat

Claims (1)

[Claims] 1. A dustproof mat formed by laminating two or more adhesive sheets having a weak adhesive layer on one surface of a support so that the support and the weak adhesive layer are in contact with each other between adjacent sheets. The above-mentioned weak adhesive layer is methoxyethyl acrylate 30-70.
Wt% and caprolactone acrylate 30-70 wt%
And a copolymerized polymer of 40 to 0% by weight of another monomer copolymerizable therewith.