JPH07138542A - Double-coated self-adhesive tape for fixing building interior material - Google Patents

Abstract

PURPOSE:To obtain the title tape which exhibits high initial adhesive strength and holding power in adhesion to the back side of a building interior material and to the surface of a substrate material and thus provides sufficient temporary fixing effects even in winter. CONSTITUTION:The title tape comprises a substrate, a self-adhesive layer formed on one side of the substrate, and another self-adhesive layer formed on the other side of the substrate. The former self-adhesive layer is formed by cross- linking, with an aziridine compd., an acrylic copolymer which has a glass transition temp. of -20 deg.C or lower and a wt. average mol.wt. of 300,000-700,000 and is obtd. by the copolymn. of monomers contg. an aziridinyl-reactive monomer. The latter self-adhesive layer is formed by cross-linking a cross-linkable acrylic copolymer having a wt. average mol.wt. of 700,000-1,000,000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided pressure-sensitive adhesive tape suitable for temporarily fixing interior materials for construction.

[0002]

2. Description of the Related Art Construction of building interior materials for forming ceilings and walls of buildings is generally carried out by using a base material such as gypsum board, plywood, mortar, and steel frame, calcium silicate board, asbestos cement calcium silicate. It is performed by fixing a decorative plate such as a plate or a melamine plate.

As a method of fixing the interior material for construction to the base material, a method using nails or bolts was used to be the mainstream. However, the use of nails or bolts deteriorates the appearance of the surface of the interior material and causes dust and noise. Since it may occur, an adhesive fixing method using an adhesive has been adopted in recent years. However, the method using an adhesive requires temporary pressing until the initial strength is expressed, and in the case of a solvent type adhesive, there is a problem such as a risk of ignition by an organic solvent and an adverse effect on the human body. However, this is not always the preferred method.

Recently, in order to eliminate the need for temporary pressing until initial strength development, which is one of the drawbacks of the adhesive method,
A method has been proposed in which a double-sided pressure-sensitive adhesive tape and an adhesive are used in combination so that the double-sided pressure-sensitive adhesive tape exerts an initial adhesive force and the adhesive exerts a final adhesive force (JP-A-4-312671).

However, the back surface of an interior material for construction, such as a calcium silicate plate, has considerable unevenness and a large amount of dust,
Further, since it is often applied at a low temperature of around 0 ° C. in winter, there is a problem that the ordinary double-sided adhesive tape lacks the initial adhesive force and cannot obtain a sufficient temporary fixing effect. On the other hand, since the surface of the gypsum board that is often used as a base material is generally pasted with paper, the degree of unevenness and dust is lower than that of the back surface of the interior material. When applied, there is a problem that the interior material cannot withstand its own weight and flexure, causing interfacial peeling from the adhesive interface and cohesive failure of the pressure-sensitive adhesive layer, so that a sufficient temporary fixing effect cannot be obtained.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the present invention, the present invention provides excellent initial adhesive strength and holding power to the interior material back surface and base material surface of a building even in winter bonding work. An object of the present invention is to provide a double-sided adhesive tape for fixing a building interior material, which has a sufficient temporary fixing effect.

[0007]

The double-sided pressure-sensitive adhesive tape of the present invention has, on one side of a substrate, a glass transition temperature of -20 ° C or less and a weight average molecular weight of 300,000 to less than 700,000.
A pressure-sensitive adhesive layer obtained by cross-linking an acrylic copolymer obtained by copolymerizing a functional monomer capable of reacting with an aziridinyl group with an aziridine cross-linking agent is formed. Is in the range of 700,000 to 1,000,000, and a pressure-sensitive adhesive layer obtained by crosslinking an acrylic copolymer containing a crosslinkable functional group is formed, thereby achieving the above object. .

More specifically, the idea of the present invention will be described.
In the double-sided pressure-sensitive adhesive tape, as the pressure-sensitive adhesive applied to the back surface of the interior material, the initial adhesive strength is important, the glass transition temperature is −20 ° C. or lower, and the weight average molecular weight is in the range of 300,000 to less than 700,000. , A pressure-sensitive adhesive obtained by cross-linking an acrylic copolymer in which a functional monomer capable of reacting with an aziridinyl group is cross-linked with an aziridine-based cross-linking agent (hereinafter referred to as "initial adhesion-oriented pressure-sensitive adhesive"), As the pressure-sensitive adhesive applied to the surface of the base material, the cohesive force is emphasized, and an acrylic copolymer containing a crosslinkable functional group having a weight average molecular weight of 700,000 to 1,000,000 is crosslinked. By using the obtained pressure-sensitive adhesive (hereinafter referred to as "cohesive force-focused pressure-sensitive adhesive"), the balance between the initial adhesive force and the cohesive force, that is, the holding force is kept good and the above-mentioned object is achieved.

The type of base material used in the double-sided pressure-sensitive adhesive tape of the present invention is not particularly limited, and non-woven fabrics, plastic films, foams and the like are preferably used. Among them, foams are particularly preferable. It is more preferable because it has excellent followability to irregularities on the back surface of the interior material and the surface of the base material, impact absorption and the like.

Examples of the foams include polyethylene resin foam, polyurethane resin foam, vinyl chloride resin foam, acrylic resin foam, polyamide resin foam, ethylene-vinyl acetate copolymer resin foam, and chloroprene rubber. Examples of the foam include a foam, a butyl rubber foam, a styrene-butadiene copolymer rubber foam, and a natural rubber foam. Considering the conformability to the irregularities on the back surface of the interior material and the surface of the base material, the cushioning effect, etc., the thickness is 0. Polyethylene resin foam, polyurethane resin foam, acrylic resin foam and the like having a thickness of about 4 to 2 mm are preferably used.

The acrylic copolymer, which is a main component of the pressure-sensitive adhesive for initial adhesion and the pressure-sensitive adhesive for cohesive force used in the double-sided pressure-sensitive adhesive tape of the present invention, is butyl acrylate, 2-
It is obtained by copolymerizing an acrylic acid alkyl ester such as ethylhexyl acrylate as a main component with a functional monomer such as acrylic acid or hydroxyethyl methacrylate by a conventional solution polymerization method or emulsion polymerization method. The content of the functional monomer is 0.
It is preferably about 5 to 10% by weight.

In the double-sided pressure-sensitive adhesive tape of the present invention, the glass transition temperature of the acrylic copolymer, which is the main component of the pressure-sensitive adhesive for initial adhesion used on the side applied to the back surface of the interior material, may be -20 ° C or lower. is necessary. When the glass transition temperature of the acrylic copolymer is higher than −20 ° C., the fluidity of the obtained adhesive in the low temperature range is hindered, so that the adhesion of the adhesive to the back surface of the interior material is prevented especially when the adhesive is applied in winter. It deteriorates and sufficient initial adhesion cannot be obtained.

The glass transition temperature referred to here is Tg indicated by the peak value of tan δ in the viscoelastic spectrum of the acrylic copolymer.

In the present invention, the weight average molecular weight of the acrylic copolymer, which is a main component of the pressure-sensitive adhesive for initial adhesion, must be in the range of 300,000 to less than 700,000.

If the weight average molecular weight of the above acrylic copolymer is less than 300,000, the resulting adhesive will have a weak cohesive force, and a sufficient holding force cannot be obtained. On the other hand, when the weight average molecular weight of the acrylic copolymer exceeds 700,000, even if the glass transition temperature of the acrylic copolymer is -20 ° C or lower, the fluidity of the obtained adhesive in the low temperature range is low. Since it is hindered, a sufficient initial adhesive force cannot be obtained especially in the case of bonding in winter.

In the present invention, the acrylic copolymer, which is a main component of the pressure-sensitive adhesive for initial adhesion, needs to be crosslinked with an aziridine crosslinking agent. Generally, an isocyanate-based crosslinking agent is often used when preparing an acrylic pressure-sensitive adhesive, but when the molecular weight of the acrylic-based copolymer is small, it is difficult to obtain sufficient cohesive force, which is disadvantageous in developing holding power. Therefore, it is necessary to use an aziridine-based crosslinking agent for the crosslinking of the acrylic copolymer, which has a weight average molecular weight of 300,000 to less than 700,000, which is relatively low.

The type of the above-mentioned aziridine crosslinking agent is not particularly limited, but N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β- Aziridinyl propionate, N, N'-hexamethylene-1,6
It is preferably a bifunctional or higher functional aziridine compound such as -bis (1-aziridinecarboxamide). The addition amount of the aziridine-based cross-linking agent is not particularly limited, but is preferably about 0.05 to 2 parts by weight based on 100 parts by weight of the acrylic copolymer in terms of solid content, and particularly preferably 0.
About 1 to 0.5 parts by weight is more preferable.

In the double-sided pressure-sensitive adhesive tape of the present invention, the weight average molecular weight of the acrylic copolymer, which is the main component of the cohesive force-oriented pressure-sensitive adhesive used on the side applied to the surface of the base material, is 7
It should be in the range of 0,000 to 1,000,000.

If the weight average molecular weight of the acrylic copolymer is less than 700,000, the desired adhesive strength cannot be obtained because the pressure-sensitive adhesive obtained has a low cohesive force. On the other hand, when the weight average molecular weight of the acrylic copolymer exceeds 1,000,000, the fluidity of the obtained pressure-sensitive adhesive is hindered, so that the initial adhesiveness at the time of adhesive bonding particularly in winter deteriorates.

In the present invention, the acrylic copolymer, which is the main component of the cohesive strength-oriented adhesive, must be crosslinked with a crosslinking agent. Since the acrylic copolymer has a weight average molecular weight of 700,000 to 1,000,000, which is a relatively high range, the crosslinking agent is not limited to an aziridine-based crosslinking agent, but an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, or a metal. A system crosslinking agent etc. are also used suitably.

As the aziridine-based crosslinking agent, the bifunctional or higher functional aziridine-based compound as described above is preferably used, and as the isocyanate-based crosslinking agent, tolylene diisocyanate or its hydride, or trimethylol propane of tolylene diisocyanate is used. A polyisocyanate compound having two or more isocyanate groups in the molecule, such as an adduct thereof with triphenylmethane triisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate, is preferably used.

The amount of the cross-linking agent added is not particularly limited, but is preferably about 0.05 to 2 parts by weight based on 100 parts by weight of the acrylic copolymer in terms of solid content, of which 0.1 is particularly preferable. It is more preferably about 0.5 part by weight.

The initial adhesion-oriented pressure-sensitive adhesive and the cohesive force-oriented pressure-sensitive adhesive used in the double-sided pressure-sensitive adhesive tape of the present invention contain a tackifying resin such as a rosin-based resin or a petroleum-based resin in order to increase the tackiness. It may be.

The tackifying resin is not particularly limited, but it is preferable to use a tackifying resin having a relatively low softening point around 40 ° C., and the blending amount of the tackifying resin is solid content. It is desirable that the amount is about 30 parts by weight or less based on 100 parts by weight of the acrylic copolymer. When the softening point of the tackifying resin is higher than about 40 ° C., the glass transition temperature of the obtained pressure-sensitive adhesive increases, so that the initial adhesive strength in the low temperature range decreases. If the solid content of the tackifying resin is more than about 30 parts by weight based on 100 parts by weight of the acrylic copolymer, the cohesive force of the resulting pressure-sensitive adhesive will be weakened and the holding power will be lowered.

In the double-sided pressure-sensitive adhesive tape of the present invention, the method of coating the pressure-sensitive adhesive with an emphasis on initial adhesion and the pressure-sensitive adhesive with a focus on cohesive force on the substrate is as follows. Alternatively, the release-treated surface of the release paper may be attached to the release-treated surface, or the release-treated surface of the release paper may be coated with each pressure-sensitive adhesive and dried, and then the release-treated surface may be attached to the corresponding base material side. However, the latter method is generally preferable because it has better coating workability.

The coating thickness of the adhesive on the substrate is not particularly limited, but the thickness after drying is 40 to 1 on one side.
About 50 μm is preferable. When the coating thickness of the adhesive is less than about 40 μm after drying, the initial adhesive strength becomes weak when the back surface of the interior material or the surface of the base material has large irregularities or a large amount of dust adheres. . If the coating thickness of the pressure-sensitive adhesive exceeds about 150 μm in terms of the film thickness after drying, the excessive coating is performed and stress concentrates on the pressure-sensitive adhesive layer, which rather lowers the holding power.

[0027]

The double-sided pressure-sensitive adhesive tape for fixing building interior materials obtained according to the present invention has a glass transition temperature of -20 ° C or less and a weight average molecular weight of 300,000 to less than 700,000 on the side of the base material applied to the back surface of the interior material. In the range of, a pressure-sensitive adhesive layer of the initial adhesion importance type obtained by crosslinking an acrylic copolymer copolymerized with a functional monomer capable of reacting with an aziridinyl group with an aziridine crosslinking agent is formed, and , A cohesive force-oriented adhesive obtained by crosslinking an acrylic copolymer containing a crosslinkable functional group having a weight average molecular weight of 700,000 to 1,000,000 on the surface of the base material applied to the surface of the base material Since the adhesive layer is formed, the adhesive layer has fluidity even in winter, and has excellent initial adhesiveness to the back surface of the interior material and the surface of the base material, and also improves the cohesive strength of the adhesive by crosslinking. Because it has It is those having good adhesion properties balanced.

[0028]

EXAMPLES In order to explain the present invention in more detail, examples will be given below. In the examples, "part" is "part by weight".
Means

(Example 1)

( 1) Preparation of double-sided pressure-sensitive adhesive tape Both sides of a polyethylene resin foam "Softlon # 1001" (manufactured by Sekisui Chemical Co., Ltd.) having a foaming ratio of 10 times and a thickness of 1.0 mm are treated at a treatment rate of 40 dyn / cm or more. A corona-treated substrate was prepared.

Next, in order to obtain a pressure-sensitive adhesive that emphasizes initial adhesion,
As shown in Table 1, solution copolymerization was carried out using 97 parts of 2-ethylhexyl acrylate and 3 parts of acrylic acid as a solvent and ethyl acetate as a solvent to obtain an acrylic copolymer solution having a solid content of 40%. The glass transition temperature of the obtained acrylic copolymer measured by a viscoelastic spectrometer was −26 ° C., and the weight average molecular weight thereof measured by GPC was 500,000. Solid content of the obtained acrylic copolymer 100
Parts, N, N'-hexamethylene-
A 2% isopropyl alcohol solution of 1,6-bis (1-aziridinecarboxamide) (trade name "HDU", manufactured by Mutual Pharmaceutical Co., Ltd.) was added so that the solid content would be 0.2 parts,
An adhesive A with a focus on initial adhesion was prepared containing an aziridine crosslinking agent.

Further, in order to obtain a cohesive strength-oriented adhesive,
97 parts of 2-ethylhexyl acrylate, acrylic acid 3
Solution copolymerization was carried out using ethyl acetate as a solvent with a monomer composition of 1 part to obtain an acrylic copolymer solution having a solid content of 40%. The glass transition temperature of the obtained acrylic copolymer measured by a viscoelastic spectrometer was -24 ° C, and the weight average molecular weight measured by GPC was 900,000. A 2% isopropyl alcohol solution of HDU as a cross-linking agent was added to 100 parts of the solid content of the obtained acrylic copolymer so that the solid content was 0.2 parts, and the cohesive force containing the aziridine cross-linking agent was added. An important adhesive C was prepared.

Next, the above-mentioned pressure-sensitive adhesive A with a focus on initial adhesion was applied and dried on the release-treated surface of the release paper so that the film thickness after drying would be 100 μm, and then bonded to one surface of the substrate. Further, the cohesive force-oriented adhesive C is applied and dried on the release-treated surface of the release paper so that the film thickness after drying becomes 70 μm, and then bonded to the other surface of the base material to give an inner diameter of 3 inches. 20 mm long, with a pressure-sensitive adhesive layer of initial adhesion formed on one side of the substrate and a cohesive force-oriented adhesive layer formed on the other surface of the substrate 1
A 0 m double-sided adhesive tape was obtained.

( 2) Evaluation Using the obtained double-sided adhesive tape, the calcium silicate board and the gypsum board were bonded as an initial test and the initial adhesion at 0 ° C. to the calcium silicate board (interior material) and the gypsum board (base material). Table 2 shows the results of evaluation by the following method for the occurrence of floating due to peeling.

Initial adhesion to calcium silicate plate :
The resulting double-sided adhesive tape with a width of 20 mm is 150 mm long
And cut the surface of the double-sided pressure-sensitive adhesive tape on which the initial adhesion-oriented pressure-sensitive adhesive layer is formed in a width of 20 m in an atmosphere of 0 ° C.
m, length 150 mm, thickness 5 mm calcium silicate-based interior material "Asver" (made by Sekisui Chemical Co., Ltd.) Adhesion length 1
00 mm, peel off the release paper on the other side of the double-sided adhesive tape, a 23 μm thick PET film for backing, and one-way pressure bonding with a roller weighing 500 g, 300 mm using a Tensilon tester immediately.
90 degree angle peeling adhesive strength (g / 20m
m) was measured.

Initial Adhesion to Gypsum Board : The obtained double-sided adhesive tape having a width of 20 mm was cut into a length of 150 mm, and the cohesive force-oriented adhesive layer of the double-sided adhesive tape was formed in an atmosphere of 0 ° C. Adhesive to a plasterboard with a width of 20 mm, a length of 150 mm and a thickness of 10 mm. Length 10
Adhesion with 0 mm, the same operation as in the case of calcium silicate plate is performed below, and 90 degree angle peel adhesion strength (g / 20 m
m) was measured.

Practical test : Calcium silicate-based interior material Asvel having a width of 3 inches and a length of 6 inches (thickness: 5 mm) has a width of 20 mm and a length of 800 mm at both ends in the longitudinal direction and the central portion of the back surface. The surface of the cut double-sided pressure-sensitive adhesive tape on which the pressure-sensitive adhesive layer for initial adhesion was formed was attached and pressure-bonded. Next, at the widthwise both ends of the back surface of the asver, one width 2
The surface of the double-sided pressure-sensitive adhesive tape, which was cut to a length of 0 mm and a length of 1700 mm, on which the pressure-sensitive adhesive layer for initial adhesion was formed was attached and pressure-bonded. Furthermore, a chloroprene solvent-based adhesive "Bond G-77" (solid content 43%, viscosity at 30 ° C, 110,000 cps, manufactured by Konishi Co., Ltd.) is bead-shaped on the part of the back surface of the asbestos where the double-sided adhesive tape is not attached. 200g
3 pieces of width x length 6 installed on the ceiling in advance as a base material by peeling off the release paper from the surface of the double-sided pressure-sensitive adhesive tape on which the cohesive force-oriented pressure-sensitive adhesive layer is formed. It was stuck and pressure-bonded to the surface of a plaster board (thickness: 10 mm). After standing at room temperature for 24 hours, the presence or absence of floating due to peeling between the gypsum board and the asbestos was observed.

(Examples 2 to 4, Comparative Examples 1 to 4)

In the same manner as in Example 1, the compositions shown in Table 1 were used to prepare an initial adhesion-oriented pressure sensitive adhesive B and a cohesive force-focused pressure sensitive adhesive D. Then, seven kinds of double-sided pressure-sensitive adhesive tapes were obtained in the same manner as in Example 1 with the combinations of pressure-sensitive adhesives shown in Table 2. As for the film thickness of the adhesive after drying, the surface on the side applied to the back surface of the interior material of the double-sided adhesive tape is
The surface to be applied to the surface of the base material was 100 μm and the surface was 70 μm.

Table 7 shows the results of evaluation of the obtained seven types of double-sided pressure-sensitive adhesive tapes in the same manner as in Example 1.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

As described above, the double-sided pressure-sensitive adhesive tape according to the present invention exhibits an excellent initial adhesive force to the interior material for construction and the base material even in a low temperature range and has sufficient holding power. It is preferably used for temporary fixing of building interior materials.

Claims (1)

[Claims] 1. A glass transition temperature of −20 on one surface of a substrate.
Adhesion obtained by crosslinking an acrylic copolymer having a weight average molecular weight in the range of 300,000 to less than 700,000 below ℃ and copolymerized with a functional monomer capable of reacting with an aziridinyl group with an aziridine crosslinking agent. A pressure-sensitive adhesive layer obtained by cross-linking an acrylic copolymer having a cross-linkable functional group having a weight average molecular weight of 700,000 to 1,000,000 on the other surface of the base material on which an agent layer is formed. A double-sided adhesive tape for fixing building interior materials, characterized in that