JP3346636B2 - Dustproof mat - Google Patents

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 places where a dust-free environment is desired, such as hospitals, electronic component manufacturing factories, semiconductor manufacturing factories, and the like.

[0002]

2. Description of the Related Art In places where a dust-free environment is desired, such as hospitals, electronic component manufacturing factories, semiconductor manufacturing factories, etc., a weak adhesive layer is generally provided to remove dust and dirt attached to shoes of those who enter and exit. Uses a dust-proof mat. Various types of dust-proof mats are known, but two or more of them are typically adhesive sheets having a weak adhesive layer based on acrylic rubber on one side of a support. Are laminated so that the support and the weak adhesive layer are in contact with each other between adjacent sheets.

[0003] The dust-proof mat having the laminated structure, when the adhesive force of the uppermost adhesive sheet (weakly adhesive layer) is no longer adhered to dust and dust, peels off the adhesive sheet, In this method, the lower adhesive sheet (weak adhesive layer) is newly exposed, and each adhesive force of the laminated adhesive sheets is sequentially used.

[0004]

However, the conventional dustproof mat of this type tends to generate static electricity when the used adhesive sheet is peeled off, which impairs the peeling operation or makes it difficult for an operator. It gave pleasure and had a problem in practicality.

[0005] In view of the above circumstances, the present invention prevents the generation of static electricity when peeling a used adhesive sheet,
It is an object of the present invention to provide a practically usable dustproof mat capable of performing a peeling operation smoothly.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, when the weak adhesive layer of the adhesive sheet is formed of a specific base polymer. As a result, the inventors have found that the generation of static electricity during the peeling operation can be prevented, and have completed the present invention.

That is, according to the present invention, two or more adhesive sheets provided with a weak adhesive layer on one side of a support are laminated so that the support and the weak adhesive layer are in contact between adjacent sheets. In the dust-proof mat, the weak adhesive layer is composed of 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 by containing a copolymer polymer with a base polymer.

As described above, according to the present invention, a specific copolymer containing methoxyethyl acrylate and caprolactone acrylate as essential components is provided on the weak adhesive layer of the adhesive sheet constituting the dustproof mat. By using the base polymer as the base polymer, the high polarity based on the copolymer gives a weakly adhesive layer having a low electrical insulation, that is, a high electrical conductivity. It has been found that it greatly contributes to prevention of generation of static electricity at the time of peeling.

[0009]

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

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

As the support 2, a plastic film made of polyethylene film or the like and having a thickness of about 40 to 100 .mu.m is used. The thickness of the weak adhesive layer 3 provided on one surface of the support 2 is about 5 to 20 .mu.m. . The number of stacked adhesive sheets 1 is not limited to six as shown in the figure, and may be any number as long as it is two or more. The total thickness of the dustproof 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 made of methoxyethyl acryl
The support 2 is formed by applying a pressure-sensitive adhesive containing a copolymer containing, as an essential monomer component, lactone and caprolactone acrylate to one surface of the support 2 and drying. In the adhesive, in addition to the above copolymer as a base polymer, various additives such as a cross-linking agent, a tackifier, a surfactant, a coloring agent, a filler, and an antioxidant are included. be able to.

The adhesive properties of the weak adhesive layer 3 must be such that it can remove dust and dirt adhering to shoes well and exhibit a weak adhesive strength that does not hinder walking. The monomer composition of the copolymer and the type and amount of the cross-linking agent and other additives are appropriately determined so as to obtain a high adhesive strength. As a guide, the 180 degree peel adhesion at room temperature to a stainless steel plate is 30 ~
Preferably, the width is adjusted to be about 800 g / 20 mm width.

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

In the copolymer used as the base polymer of the pressure-sensitive adhesive, methoxyethyl acrylate is used as one of the essential components of the constituent monomer. The monomer has the following formula: The glass transition temperature of the homopolymer represented by
C. or less, and effectively functions as a monomer that imparts adhesive strength.

[0016] Caprolactone acrylate is used as another essential component of the constituent monomer.
This monomer has the following formula: Wherein the number m in the general formula is from 1 to 10
And the average value of m is in the range of 1 to 5. This type of monomer is a polymerizable carbon
The distance between the carbon double bond and the carboxyl group is large, and when this is subjected to addition polymerization, the carboxyl group bonded as a side chain to the polymerization main chain exists at a position away from the main chain. It is intended to provide a polymer having a low glass transition temperature in order to obtain a high molecular structure.

Further, as the constituent monomer other than these, a monomer copolymerizable with the above-mentioned both monomers can be used if necessary for adjusting the adhesive strength, cohesive strength and the like.
Specifically, carboxyl group-containing monomers such as (meth) acrylic acid and maleic acid, and alkyl groups having 1 to 1 carbon atoms
12 alkyl (meth) acrylates, (meth)
Examples include a hydroxyl group-containing monomer such as 2-hydroxyethyl acrylate, vinyl acetate, vinyl propionate, styrene or a derivative thereof (for example, sodium styrene sulfonate), and (meth) acrylonitrile.

[0018] The proportion of these monomers used is
Medium, 30 to 70% by weight of methoxyethyl acrylate
(Preferably 40 to 60% by weight), 30 to 70% by weight (preferably 35 to 55% by weight) of caprolactone acrylate, and 40 to 0% of another monomer copolymerizable therewith.
% By weight (preferably 25 to 5% by weight), and when the content is outside these ranges, satisfactory performances such as weak adhesion, self-back surface adhesion, electric conductivity, and hydrophilicity are satisfied. No result.

The copolymer 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, and a suspension polymerization method. . As the polymerization initiator,
Azobisisobutyronitrile, azo compounds such as azobisvaleronitrile, peroxides such as benzoyl peroxide, lauroyl peroxide, ammonium persulfate, persulfates such as potassium persulfate, and sodium hydrogen sulfite, sodium ascorbate, A redox catalyst with a metal salt or the like is used.

The 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 shows good electrical conductivity due to polar groups such as carboxyl groups, and also has excellent hydrophilicity, and also has the function of imparting properties such as water solubility, water dispersibility or water swelling to the adhesive. I have.

Dustproof mat 4 made of such a constituent material
In a place such as a hospital, an electronic parts manufacturing factory, a semiconductor manufacturing factory, or the like, the adhesive surface is on the floor surface directly or via an underlay sheet or the like, that is, the uppermost adhesive sheet in FIG. It is mounted and fixed such that the weak adhesive layer 3 of -1A is exposed on the surface. As a result, dust and dirt adhering to the pedestrian's shoe sole are effectively adhered and removed.

When the adhesive sheet 1A loses the adhesive property due to the adhesion and removal, the adhesive sheet 1A is peeled off as a used adhesive sheet, and the lower adhesive sheet 1B is exposed. In this case, the same dust-proof performance as described above can be exhibited, and this peeling operation can be repeatedly performed up to the lowermost adhesive sheet 1F. Here, in such a peeling operation, there is no fear of generating static electricity as in the related art, the peeling operation of each sheet can be performed smoothly, and the operator does not feel uncomfortable.

[0023]

As described above, according to the present invention, no static electricity is generated at the time of the peeling operation of the adhesive sheet, the peeling operation is smooth, and there is no fear of giving a worker uncomfortable feeling. Therefore, a dust-proof mat having high practical value can be provided in places where a dust-free environment is desired, such as hospitals, electronic component manufacturing factories, and semiconductor manufacturing factories.

In addition, this dustproof mat has such a property that the copolymer constituting the weakly adhesive layer of the adhesive sheet has good hydrophilicity and can be dissolved, dispersed or swelled in water. Therefore, it is possible to easily clean and collect used adhesive sheets, and even if a part of the weak adhesive layer may be transferred to the shoe sole, Therefore, it has an advantage that it can be easily washed and removed.

[0025]

Next, an embodiment of the present invention will be described in more detail. Hereinafter, “parts” means “parts by weight”.

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

A solution of the copolymer thus obtained was added to 100 parts of the copolymer with a crosslinking agent [trade name "EX-830" manufactured by Nagase Chemical Co., Ltd .; Diglycidyl ether of polyethylene glycol]
3 parts and a surfactant [trade name “T-
20C "; polyoxyethylene sorbitan fatty acid ester] and 0.1 part thereof, and uniformly mixed to obtain a pressure-sensitive adhesive composition.

Next, this pressure-sensitive adhesive composition was coated with a thickness of 60
An adhesive sheet was formed on one side of a μm polyethylene film so that the thickness of the weakly adhesive layer after drying was 10 μm, followed by drying to form an adhesive sheet. After that, this adhesive sheet is 6
These were prepared and laminated as shown in FIG. 1 to produce a dustproof mat.

Example 2 A polymerization raw material was 55 parts of methoxyethyl acrylate and 40 parts of caprolactone acrylate (the same as in Example 1).
Parts, sodium styrenesulfonate 5 parts, potassium hydroxide 8.8 parts, water 96 parts, methanol 144 parts, and azobisisobutyronitrile 0.175 parts. Went.

[0030] The same cross-linking agent and surfactant as in Example 1 were blended in the same amount as in Example 1 with the solution of the copolymer thus obtained to prepare a pressure-sensitive adhesive composition. An adhesive sheet was formed in the same manner as in Example 1. Six adhesive sheets were prepared and laminated as shown in FIG. 1 to produce a dustproof mat.

Comparative Example 1 Weight ratio of n-butyl acrylate to acrylic acid: 95: 5
A solution of the copolymerized polymer was mixed with 100 parts of the copolymerized polymer, 5 parts of an isocyanate-based crosslinking agent and 0.3 part of a phosphate ester-based surfactant to form a pressure-sensitive adhesive composition,
Using this, an adhesive sheet was formed in the same manner as in Example 1. Six adhesive sheets were prepared and laminated as shown in FIG. 1 to produce a dustproof mat.

With respect to each of the dustproof mats of Examples 1 and 2 and Comparative Example 1, the adhesive strength of the self-back surface of the adhesive sheet, the adhesive strength to a stainless steel plate, and the amount of static electricity at the time of peeling operation were determined by the following methods. And measured its performance. The results of these tests were as shown in Table 1 below.

<Measurement of Self-Back Adhesive Force>
After cutting to a width of mm, the adhesive sheet of the uppermost layer was peeled off, and the force at this time was measured with a Schooper-type tensile tester at a tensile speed of 300 mm / min and a peel angle of 180 °.

<Measurement of Adhesive Strength to Stainless Steel Plate>
The adhesive sheet before producing the dustproof mat was cut into a size of 20 mm in width and 150 mm in length to form a test piece. In addition, 27 kinds of SUS 2 specified in JIS G 4305
A 7CP steel plate is cut into a thickness of 2 mm, a width of 50 mm, and a length of 125 mm, and its surface is specified in JIS R6253.
A well-polished # 80 water-resistant abrasive paper was used as the adherend.

The above test piece was adhered to the above surface of the adherend by one reciprocation of a 2 kg rubber roller, and left for about 30 minutes. Then, at a tensile speed of 300 mm / min and a peel angle of 180 °, Adhesive strength was measured with a Schopper-type tensile tester. Both the bonding and the measurement were performed in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%.

<Measurement of the amount of static electricity>
After cutting into a size of 30cm, the topmost adhesive sheet
Then, the amount of static electricity at this time was measured with 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, the dustproof mat of the present invention has an adhesive force suitable for the intended use of the laminated adhesive sheet, and generates static electricity during the peeling operation. It does not occur at all, indicating that it has excellent performance as a dustproof mat used in hospitals and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a configuration of a dustproof mat of the present invention.

[Explanation of symbols]

 Reference Signs List 1 (1A to 1F) adhesive sheet 2 support 3 weak adhesive layer 4 dustproof mat

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-234630 (JP, A) JP-A-60-234634 (JP, A) JP-A-4-211438 (JP, A) 44053 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47L 23/22 C09J ⁷ /00-7/04 C09J 7/02

Claims (1)

(57) [Claims] 1. A dustproof mat made by laminating two or more adhesive sheets having a weak adhesive layer on one side of a support so that the support and the weak adhesive layer are in contact between adjacent sheets. The methoxyethyl acrylate 30 to 70,
% By weight and 30-70% by weight of caprolactone acrylate
A dustproof mat comprising: a copolymer of 40% to 0% by weight of another monomer copolymerizable therewith.