JPH05148460A - Tacky tape having excellent weather resistance - Google Patents

Abstract

PURPOSE:To obtain the subject tacky sheet having extremely improved deterioration by ultraviolet rays, having excellently weather resistance and unwinding properties by mixing and dispersing inorganic pigment having fixed particle diameter into a substrate or a tacky agent of tacky sheet. CONSTITUTION:Inorganic filler having 0.001-0.1mum particle diameter, preferably zinc oxide or titanium oxide is mixed and dispersed into a substrate or a tacky agent of a tacky sheet composed of polyethylene resin to give the objective sheet whose cost can be reduced. A transparent ultraviolet light screening layer comprising a resin and inorganic filler having <0.1mum particle diameter is preferably laid between the tacky agent and the substrate.

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 sheet, tape or film (hereinafter referred to as a pressure sensitive adhesive sheet) having excellent weather resistance.

[0002]

2. Description of the Related Art Adhesive sheets are used for construction, for the purpose of surface protection.
It is used in various fields such as housing equipment, home appliances / OA, and automobiles. Particularly when used outdoors for a long period of time such as in construction, it is necessary to use an adhesive sheet that has been subjected to ultraviolet ray resistance measures in order to prevent deterioration due to sunlight, and various countermeasure methods shown below have been proposed so far. (1) Addition of an ultraviolet absorber to the adhesive. (2) Addition of an ultraviolet absorber to the support (JP-A-58-2)
No. 20139, JP-A-61-111341,
JP-A-2-251590). (3) Formation of an ultraviolet absorbing layer on the surface of a support (JP-A-58)
No. 29664, No. 62-263045, No. 2-24140, and No. 57-187.
248, and JP-A-2-170828).

[0003]

However, with respect to (1) to (3) shown in the prior art, in order to develop sufficient ultraviolet absorption by adding an ultraviolet absorber,
Since it is necessary to use a relatively large amount, there arises a problem of bleeding out on the pressure-sensitive adhesive or the back surface of the support. In addition, addition of a large amount cannot be expected because of a problem such as a decrease in adhesion between the pressure-sensitive adhesive and the support and coloring, which cannot be added in a large amount, and a sufficient effect of ultraviolet absorption cannot be expected. Further, since the ultraviolet absorber is an organic compound, it is deteriorated, volatilized and decomposed by ultraviolet rays or heat, and it is difficult to maintain stable characteristics for a long period of time. In order to solve the above-mentioned problems, the present inventors have previously proposed to form an ultraviolet blocking layer composed of an inorganic pigment on the surface of a support.

By changing the ultraviolet absorber to an inorganic pigment, bleed-out, alteration, volatilization, decomposition and the like can be suppressed, and a support excellent in stain resistance and ultraviolet resistance can be obtained. However, if this product is stored in a rolled state, the adhesive strength between the ultraviolet blocking layer applied to the surface of the support and the pressure-sensitive adhesive will increase abnormally, and the rewindability of the pressure-sensitive adhesive sheet will decrease, making it difficult to peel off. was there. In particular, it is remarkable when the polarities of the resin and the adhesive in the ultraviolet blocking layer are close to each other.

[0005]

The present inventors have completed the present invention as a result of earnestly conducting experiments and researches in order to solve the problems such as bleed-out and difficulty in rewinding found in the prior art. Came to do. That is, the present invention is to mix or disperse an inorganic pigment having a specific particle size in the support or the pressure-sensitive adhesive of the pressure-sensitive adhesive sheet, or to use a transparent ultraviolet ray composed of a resin and an inorganic pigment between the pressure-sensitive adhesive and the support. The present invention relates to a pressure-sensitive adhesive sheet having a blocking layer.

The inorganic pigments used in the present invention include white pigments (titanium oxide, zinc oxide, lithopone, lead white), extender pigments (chalk, barium sulfate, alumina white, silica white,
(White clay), black pigments (carbon black, lamp black, iron black, diamond black), red pigments (red iron oxide, vermilion, cadmium red, cadmium mercury red, chrome vermillion, red lead, rekki red 4R, lake red C,
Wochan Red, Quinacridone Red, Rose Red, Madara Lake, Bon Maroon, Brilliant Carmine, Western Vermilion), Yellow Pigment (Yellow Lead, Dicyclochrome, Cadmium Yellow, Ocher, Titanium Yellow, Hansa Yellow, Benzicine Yellow), Green Pigment (Chrome green, chromium oxide, viridian, phthalocyanine green, green gold, acid green gold),
Blue pigment (dark blue, ultramarine, phthalocyanine blue, Victoria blue lek, peacock blue rake), purple pigment (manganese bio red, cobalt violet red),
Examples include metal powder pigments (aluminum powder, bronze powder) and the like.
Among these, zinc oxide, titanium oxide and the like, which have high ultraviolet ray reflection (absorption) properties, are preferably used, and the particle size is preferably 0.001 to 0.1 μm in order to ensure transparency.

The support used in the present invention includes polyesters such as polyethylene terephthalate and polybutylene terephthalate, aliphatic or aromatic polyamides, polyolefins such as polyethylene and polypropylene, polystyrene, polycarbonate, polyvinyl chloride and polyvinylidene chloride. Synthetic resin film, semi-synthetic resin film such as cellulose acetate, synthetic resin film comrades, synthetic resin film and semi-synthetic resin film,
Further, a laminated film of a synthetic resin film and / or a semi-synthetic resin film and paper, etc. may be mentioned.
Further, a light stabilizer (ultraviolet absorber, quencher, etc.), an antioxidant, etc. may be added to the support to an extent that the transparency is not hindered, and the weather resistance is further improved. The pressure-sensitive adhesive used in the present invention is not particularly limited, but an acrylic acid ester-based polymer or a polyisobutylene-based one is particularly preferable in view of its use.

The amount of the support material or pressure-sensitive adhesive to be mixed with the inorganic pigment is 50 to 95 parts by weight, preferably 75 to 90 parts by weight, and 50 to 5 parts by weight of the inorganic pigment.
It is preferably from 25 to 10 parts by weight, and when the amount of the inorganic pigment is less than 5 parts by weight, sufficient UV blocking property cannot be expected,
If the amount is more than parts by weight, dispersibility in the support material and adhesion between the pressure-sensitive adhesive and the support will deteriorate. In order to enhance the dispersibility of the inorganic pigment, it is preferable to perform the surface treatment of the inorganic pigment with a higher fatty acid salt having 6 or more carbon atoms such as stearic acid, lauric acid and oleic acid, a silane coupling agent and a titanium coupling agent. The support material and the inorganic pigment may be kneaded and formed into a sheet by a masterbatch or an ordinary method. An acrylic adhesive is preferably used as the pressure-sensitive adhesive applied to this sheet, and its thickness is usually 10 μm or less.

In the present invention, an ultraviolet blocking layer may be provided between the support and the pressure sensitive adhesive. The UV blocking layer comprises a mixture of 10 to 90 parts by weight of a resin and 90 to 10 parts by weight of an inorganic pigment having a particle size of less than 0.1 μm. When the amount of the inorganic pigment is more than 90 parts by weight, the ultraviolet blocking layer moldability and the adhesion to the support and the pressure-sensitive adhesive are lowered, and when it is less than 10 parts by weight, the ultraviolet ray reflection (absorption) ability is lowered. As a resin,
Acrylic resins, alkyd resins, amino resins, nitrocellulose, polyester resins, phenol resins, ketone resins and the like can be mentioned, and acrylic resins having excellent weather resistance themselves are preferably used.

A resin and an inorganic pigment are essential for the ultraviolet blocking layer, and a crosslinking agent, a catalyst and the like may be added. If the thickness of the ultraviolet blocking layer is 1 μm or more, it can be freely adjusted within the range where the transparency is not lost. The above-mentioned formulation is usually applied by coating on a support in the form of being dissolved and diluted in a solvent and drying. In order to obtain stronger adhesion between the support and the ultraviolet blocking layer, a support having a wettability improved by surface treatment by a general method is preferably used.

[0011]

The technical point of the pressure-sensitive adhesive sheet of the present invention is to provide a layer containing an inorganic pigment having a specific particle size. Unlike organic UV absorbers, inorganic pigments are not contaminated by bleed-out, are less likely to undergo alteration, volatilization, or decomposition compared to organic UV absorbers, and are extremely stable against UV and heat for a long period of time. It can maintain stable characteristics. Also, if an ultraviolet blocking layer is provided inside the adhesive sheet,
Good rewindability with no increase in adhesive strength. as a result,
A pressure-sensitive adhesive sheet that can be used for outdoor applications requiring weather resistance can be obtained.

[0012]

EXAMPLES Hereinafter, the present invention will be described with reference to Examples.
The scope of the invention is in no way limited by these examples. However, all parts are parts by weight.

Example 1 80 parts of polyethylene resin (manufactured by Showa Denko KK, Shorex Linear) as a support material, ultrafine zinc oxide (manufactured by Sumitomo Cement KK, ZnO-100, particle size 0.005)
0.015 μm) A 60-μm-thick polyethylene sheet consisting of 20 parts is coated with a 6 wt% toluene solution of acrylic rubber (Toa Paint Co., Ltd., XE-2644) on one surface of the corona-treated surface to a thickness of 3 μm after drying. To obtain an adhesive sheet. The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1. Example 2 The same as Example 1 except that the ultrafine zinc oxide was changed to ultrafine titanium oxide (produced by Sakai Chemical Industry Co., Ltd., particle size 0.005 to 0.015 μm, rutile type). The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1. Example 3 The same as Example 1 except that the ultrafine zinc oxide was changed to ultrafine titanium oxide (produced by Sakai Chemical Industry Co., Ltd., particle size 0.005 to 0.015 μm, anatase type). The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1. Example 4 Ultrafine zinc oxide was added to ultrafine iron oxide (Titanium Industry Co., Ltd.)
Manufacture, particle size is 0.005 to 0.015 μm), and the same as Example 1. The characteristics of this adhesive sheet are shown in Table 1.
Shown in.

Example 5 Acrylic rubber (manufactured by Nippon Carbide Co., Q-1851)
(EA / 2-EHA / HEMA)) 80 parts, ultrafine particles Z
6% by weight consisting of 20 parts of nO (ZnO-100, manufactured by Sumitomo Cement Co., Ltd., particle size 0.005 to 0.015 μm)
60 μm thick light stabilizer-added polyethylene film (light stabilizer: hindered amine-based quencher (Tinubin 622LD manufactured by Ciba-Geigy Co., Ltd.)),
Phenolic antioxidant (Irganox 1070 manufactured by Ciba-Geigy Co., Ltd. (5 parts of light stabilizer added to 100 parts of polyethylene)) was applied on one side of the corona-treated surface so that the thickness after drying was 3 μm. , As an adhesive sheet. The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1.

Example 6 Acrylic rubber (manufactured by Nippon Carbide Co., Q-1851)
(EA / 2-EHA / HEMA)) 70 parts, ultrafine particles Z
Composition consisting of 30 parts of nO (Sumitomo Cement Co., Ltd., ZnO-100, particle size 0.005 to 0.015 μm), and 1 part of trifunctional aliphatic isocyanate (Sumitomo Bayer Urethane Co., Ltd., Sumidule N) A UV stabilizer of 10 wt% toluene solution was added to a 60 μm thick polyethylene film with a light stabilizer (light stabilizer: hindered amine quencher (Tinubin 622LD manufactured by Ciba-Gaigi Co., Ltd.)), phenolic antioxidant (Ciba-gaigi ( Co., Ltd., Irganox 1070 (5 parts of light stabilizer added to 100 parts of polyethylene)) has a thickness of 4 after drying on the corona-treated surface on one side.
to a thickness of μm to form an ultraviolet blocking layer, on which acrylic rubber (XE-26 manufactured by Toa Paint Co., Ltd.) is formed.
44 (BA / AN / HEA)) 6% by weight toluene solution adhesive was applied so that the thickness after drying would be 3 μm,
It was an adhesive sheet. The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1.

Comparative Example 1 Acrylic rubber (XA-264 manufactured by Toa Paint Co., Ltd.)
The 6% by weight toluene solution pressure-sensitive adhesive of 4) was applied to one side of the corona-treated surface of a 60 μm thick light stabilizer-added polyethylene film so that the thickness after drying was 3 μm to give a pressure-sensitive adhesive sheet. The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1. Comparative Example 2 Acrylic rubber (manufactured by Nippon Carbide Co., Ltd., Q-1851)
(EA / 2-EHA / HEMA)) 70 parts, benzotriazole type ultraviolet absorber (Ciba-Geigy Co., Ltd., Tinuvin 326) 30 parts, trifunctional aliphatic isocyanate (Sumitomo Bayer Urethane Co., Ltd., Sumidule N) A 1 part composition of 10% by weight of a toluene solution of an ultraviolet blocking agent was applied to one side of a 60 μm thick double-sided corona-treated light stabilizer-added polyethylene film so that the thickness after drying would be 4 μm. An acrylic rubber (Toa Paint Co., Ltd.) is formed on the opposite side of the polyethylene film to form a blocking layer.
Manufactured by XE-2644 (BA / AN / HEA) (6% by weight toluene solution) was applied to give an adhesive sheet having a thickness of 3 μm after drying. The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1.

Comparative Example 3 Same as Comparative Example 2 except that 95 parts of acrylic rubber (Q-1851) and 5 parts of benzotriazole type ultraviolet absorber (Tinuvin 326) were used. The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1. Comparative Example 4 Acrylic rubber (XA-264 manufactured by Toa Paint Co., Ltd.)
4) A 6 wt% toluene solution adhesive consisting of 100 parts and 5 parts of a benzotriazole type ultraviolet absorber (Tinubin 326, manufactured by Ciba-Geigy Co., Ltd.) was applied in the same manner as in Example 6 to obtain an adhesive sheet. The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1. Comparative Example 5 Butyl acrylate (85 parts), acrylonitrile (10
Part) and 2-hydroxylethyl acrylate (5 parts)
By emulsion polymerization (initiator: hydrogen peroxide, emulsifier: nonionic surfactant, reaction temperature-time: 75 ° C.-3 hours), washed with water and dried to obtain Tg of about −42 ° C. and Mw of about 1.3 million. Obtained acrylic rubber. Then, the obtained acrylic rubber was dissolved in toluene to prepare a 6 wt% solution. Further rubber solids 1
Melan 22 as a methylol compound for 00 parts
(Hitachi Chemical Co., Ltd., butyl etherified methylol melamine) 3 parts and 0.3 parts of paratoluene sulfonic acid as a catalyst were mixed to prepare an adhesive solution. This pressure sensitive adhesive was applied in the same manner as in Example 5 to obtain a pressure sensitive adhesive sheet. The characteristics of this pressure-sensitive adhesive sheet are shown in Table 1.

[0018]

[Table 1]

Test contents 1) Bleed-out property The pressure-sensitive adhesive sheet was allowed to stand for 2 months under each condition of room temperature of 65 ° C., 40 ° C. and 90% RH, and it was observed whether the ultraviolet ray blocking agent or the light stabilizer was bled out. ○: No bleed-out ×: With bleed-out 2) Weather resistance Adhesive sheet is roll-pressed onto an Al plate and sunshine weather meter (Suga Test Instruments Co., Ltd., WEL-SUN-
HC type), the atmosphere: 43 ° C., 60% RH (black panel temperature: 63 ° C.), rainfall: 12 min / h, treatment time: 800 h, and the adhesive is transferred to an Al plate during peeling. I observed what I was wearing. ○: No transfer is observed. Δ: Transferring is recognized within the range of 20% or less of the surface area of the Al plate. X to Δ ... Transferring is recognized in the range of 20 to 50% of the surface area of the Al plate. X: Transferring is recognized in the range of 50% or more of the Al plate surface area. 3) Rewinding property After production, 4 at 15 to 30 ° C. and 55 ± 20% RH.
25 mm of two layers of adhesive sheet rolls that have been used for 8 hours or more
Cut to 100 mm square and tensile tester (Fudo Kogyo Co., Ltd.)
The rewinding force was measured by using a rheometer NRM-3002D-H type manufactured by K.K. Rewinding ability 〇 ・ ・ ・ ・ ・ Rewinding force ≦ 100gf / 25mm Good △ ・ ・ ・ Rewinding force> 100gf / 25mm〜 ≦ 200gf / 25mm ↑ × 〜 △ ・ ・ ・ Rewinding force ＞ 200gf / 25mm ~ ≦ 300gf / 25mm ↓ × Rewinding force> 300gf / 25mm Poor 4) Peelability Adhesive film is roll-pressed onto polyester coated steel plate with surface roughness of 3μm and put between two iron plates 30 kgf / cm ²
After the pressure was applied for 3 months at 65 ° C., the peel resistance of the adhesive film was measured using a tensile tester. 〇 ・ ・ ・ Peeling resistance is 400gf / 25mm or less △ ・ ・ ・ ・ ・ 〃 400 to 550gf / 25mm × 〜 △ ・ ・ ・ 〃 550 to 700gf / 25mm × ・ ・ ・ ・ ・ 〃 700gf / 25mm or more It is indicated by the symbol above.

[0020]

As is clear from the results shown in Table 1, the pressure-sensitive adhesive sheet according to the present invention can be prepared by adding an inorganic pigment which does not bleed out to the support or the pressure-sensitive adhesive, or between the support and the pressure-sensitive adhesive. By providing an ultraviolet blocking layer on the sheet, deterioration due to ultraviolet rays can be significantly suppressed, and the adhesive sheet can be provided with remarkable weather resistance, and can be used not only indoors but also outdoors for a long period of time. Furthermore, since the rewinding property does not decrease due to the increase in adhesive strength, the ultraviolet blocking layer provided inside the support can be used as a part of the adhesive,
The original thickness of the adhesive can be reduced, and the cost can be reduced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutaka Yamaguchi 1500 Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Research Center

Claims (5)

[Claims] 1. A pressure-sensitive adhesive sheet comprising a support or a pressure-sensitive adhesive of a pressure-sensitive adhesive sheet, wherein an inorganic pigment having a particle size of 0.001 to 0.1 μm is mixed and dispersed. 2. A pressure-sensitive adhesive sheet, comprising a transparent UV-blocking layer comprising a resin and an inorganic pigment having a particle size of less than 0.1 μm between the pressure-sensitive adhesive and the support. 3. The pressure-sensitive adhesive sheet according to claim 1, wherein the amounts of the support material or pressure-sensitive adhesive and the inorganic pigment are 50 to 95 parts by weight of the support material or pressure-sensitive adhesive and 50 to 5 parts by weight of the inorganic pigment. 4. The ultraviolet blocking layer comprises 10 to 90 parts by weight of a resin,
A composition comprising 90 to 10 parts by weight of an inorganic pigment.
The adhesive sheet described in. 5. The pressure-sensitive adhesive sheet according to claim 1, wherein the inorganic pigment is zinc oxide or titanium oxide.