JPS62161877A - Adhesive sheet - Google Patents

Abstract

PURPOSE:To obtain an adhesive sheet enhanced in resistance to bond strength loss under humid conditions to glass, by application on a substrate film of an adhesive prepared by incorporating a polyacrylic ester adhesive with a specific metal compound. CONSTITUTION:The objective adhesive sheet can be obtained by application on pref. a polyester film or polyvinyl chloride film as the substrate, of an adhesive prepared by incorporating (A) a polyacrylic ester-based adhesive with (B) pref. <=0.001wt%, based on the component A, of a metal compound of formula (Me is metal, pref. Ti, Zr or Cr; OR is alkoxy or acylate).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure-sensitive adhesive sheet for increasing moisture-resistant adhesive strength, particularly to glass.

In general, adhesive sheets attached to glass surfaces have sufficient adhesive strength in normal environmental humidity spaces, but adhesive sheets attached to window glass in high humidity environments, such as bathrooms and greenhouses, After a while after being pasted, the bonding force between the glass surface and the adhesive is weakened by the influence of moisture in the air that enters from the sheet surface, resulting in the sheet becoming significantly more likely to peel off. Ta.

The inventor believes that this phenomenon does not occur on smooth plastic or metal plates, but only occurs when adhesive is attached to a glass plate. It is presumed that moisture that has penetrated through the film intervenes between the bonds between the glass component and the glass component, weakening the bonding force.

Based on this assumption, the present inventors applied an aqueous solution containing a surfactant to the window glass using a conventional method, and applied uniform pressure to the sheet surface so as not to leave air and water droplets between the adhesive sheet 1- and the glass interface. (Igor), remove from the edge of the sheet, and before drying, add the following chemical structural formula (I)% formula (I) to the surfactant aqueous solution (where Me-OR is an alkoxy group or When a metal compound containing (representing an acylate group) is added and mixed, the adhesive strength is significantly improved compared to when the compound is not added, especially when the adhesive sheet is held in a humid environment. It was found that the strength increased without causing any decrease.

I believe that this phenomenon occurs when the metal compound Me-OR has an alkoxy group, which reacts with water to form Me-OR.
+ H20-+M e -(OH)10ROM, and the above M e -(OH) further reacts with Si-OH on the glass surface to form Me-(OH)10S i-OH-)M
It is believed that the result is e-〇-5i+H20, and the glass surface becomes hydrophobic. In addition, the metal-based compound, Me-O
When OR of R is acylate, it is thought that in the process of polymer reaction caused by addition reaction with water, further reaction proceeds with Si-OH on the glass surface, and in either case, these reactions cause adhesive It is thought that a metal compound is interposed between the agent or the film and the glass surface to form a strong bond, which prevents the bond between water and the glass due to moisture absorption.

It has been confirmed that this result similarly occurs when a pressure-sensitive adhesive sheet made by adding and mixing the metal compound into an adhesive, rather than adding and mixing it with a surfactant, is applied in a conventional manner. Ta.

The amount of the metal compound corresponding to the formula (I) described here should be at least o, ooos weight% solution concentration when used mixed in a surfactant solution, and should not exceed this concentration. No effect was observed.

Similarly, when a metal compound corresponding to formula (I) is mixed into an adhesive and used, the weight relative to the adhesive is 0.0
0.01% or more is required, and the preferable usage amount is 0.01% or more.

Next, examples of the present invention will be shown.

Add and mix 0.05% zirconium laurate to a polyacrylic acid ester adhesive and apply it uniformly to a thickness of about 0.1 + a on a 50μ thick polyester film,
It was dried at a temperature of 100° C. for 5 minutes to prepare a pressure-sensitive adhesive sheet for adhering to glass.

Next, 25 mm wide x 150 cut pieces of the glass adhesive sheet were attached to a 3 m thick glass plate to obtain test sample A. After hanging the sample indoors for 2 days,
After being immersed in water for 24 hours, taken out and dehydrated, the adhesive strength was immediately measured using a Schopper peel tester. The following table shows the results of comparison with Sample B, which was treated in the same manner with an adhesive that does not use a zirconium compound, as a control.

Table 1 0.01% of isoprobyl triisostearoyl titanate 1-C,H2C-Ti○ ■ -[○CC1tH3sL was mixed with polyacrylic acid ester adhesive, Example 1
The adhesive strength was measured in the same manner as above and compared with the control sample.

Table 2 Mix 0.05% methacryloxydimethoxychromium with polyacrylic acid ester adhesive and apply it uniformly to a thickness of about 0.1nrn on a 50μ thick polyester film.
Dry for 5 minutes at a temperature of 00°C to form an adhesive sheet for attaching glass 1.
- was prepared.

Next, a cut piece having a width of 25 nrn and a length of 150 m was adhered to a glass plate having a thickness of 3 mm to obtain a test sample A. The sample was left indoors for 2 days, then immersed in water for 24 hours, taken out, dehydrated, and immediately tested with a Schopper peel tester to determine the adhesion strength of 31! I decided. The following table shows the results of comparison with Sample B, which was treated in the same manner with an adhesive that does not use a zirconium compound, as a control.

Table 3 As is clear from the test results of Examples 1 and 2.3, when an adhesive sheet is attached to a glass plate, at least 0.001% by weight of the following formula M e - 0R (However,
By mixing metallized metals having (Me in the formula, total bending, and OR representing an alkoxy group or an acylate group), the moisture resistance strength can be at least several times higher than when these metal compounds are not added. was completed.

Claims (1)

[Claims] 1) A polyacrylic acid ester pressure-sensitive adhesive having the following chemical structural formula (I) Me-OR...(I) (wherein, Me is a metal, and OR is an alkoxy group or an acylate group. A pressure-sensitive adhesive sheet characterized by adding and mixing a metal compound having the following properties to enhance the moisture-resistant adhesive strength of the pressure-sensitive adhesive to glass. 2) The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive sheet is a sheet based on a polyester film or a polyvinyl chloride film. 3) The adhesive sheet according to claim 1, wherein the metal (Me) in formula (I) is titanium (Ti). 4) Metal (Me) in formula (I) is zirconium (Zr
) The pressure-sensitive adhesive sheet according to claim 1. 5) The adhesive sheet according to claim 1, wherein the metal (Me) in formula (I) is chromium (Cr). 6) The pressure-sensitive adhesive sheet according to claim 1, wherein the metal compound of formula (I) is mixed in an amount corresponding to at least 0.001% by weight based on the pressure-sensitive adhesive.