JPH0243045A - Self-adhesive film for sunshine controlling plastic windowpane material and plastic windowpane material glued therewith - Google Patents

Abstract

PURPOSE:To obtain a self-adhesive film, in the usage of which blister is prevented from developing and, at the same time, which is excellent in adhesive force and weatherability by a method wherein acrylic ester-based monomer unit, polar acrylic monomer unit and macromonomer unit having polymerizable functional group in polymer chain and at terminal are added one another at the predetermined ratio. CONSTITUTION:The self-adhesive film concerned is produced by coating one side of plastic film having sunshine controlling function with adhesive composition consisting mainly of copolymer, which is composed of 50-80wt% of acrylic ester-based monomer unit of (A) unit, 1-30wt% of polar acrylic monomer unit of (B) unit and macromonomer unit having polymerizable functional group in polymer chain and at terminal of (C) unit, the weight ratio of (B) unit to (C) unit of which is 0.02-6, the weight average molecular weight of which is 150,000-2,000,000 and the glass transition temperature of which is -60-60 deg.C. As a result, the resultant film can be pasted to transparent plastic plate without developing poor external appearance and poor adhesion due to the generation of blister.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to an adhesive sheet for a plastic window material having a solar control function and a plastic window material. More specifically, the present invention relates to a pressure-sensitive adhesive sheet for a plastic window material made by applying a blister-resistant adhesive composition to the surface of a plastic film having a solar control function, and a plastic window material having a solar control function to which the above pressure-sensitive adhesive sheet is attached.

[Prior Art 1] The use of plastic materials such as acrylic resins and polycarbonate resins in place of glass is rapidly increasing as window materials for buildings, automobiles, etc. due to their light weight and impact resistance. Depending on the purpose of window materials, it is necessary to adjust sunlight, and there is a need for window materials that have a so-called sunlight adjustment function.

In general, there are the following methods for imparting solar control functions to window materials.

(1) Color the window material.

(2) A thin metal film is provided on the surface of the window material.

(3) Apply colored film.

(4) Apply metallizing film.

(5) Attach a colored film that has a substance inside or on the surface that blocks light of specific wavelengths such as ultraviolet and infrared wavelengths.

Among these methods, methods (1) and (2) require solar control treatment to be performed on each window material, resulting in extremely high costs and disadvantages.

In contrast, with methods (3) to (5), solar control window materials can be obtained by simply processing thin films into rolls and attaching the films to window materials that require solar control treatment. , which has the advantage of being easy to operate and inexpensive to produce.

However, while all of the above methods (1) to (5) can be applied to glass windows, methods (3) to (5) of attaching a film with a solar control function to plastic window materials are applied. There is a problem if you do. In other words, the most common method for attaching film to plastic window materials is to attach an adhesive film coated with a pressure-sensitive adhesive to the film. When an adhesive sheet used for a material is attached to a molded product made of styrene resin or polycarbonate resin, spots of air bubbles may occur between the sheet and the resin adherend, causing blisters such as blisters and floats. many.

The occurrence of such blisters can occur in cases such as window materials,
This makes the appearance extremely unsightly, and especially in transparent window materials, the adhesive surface looks transparent or cloudy, which inevitably impairs the appearance significantly.

This phenomenon is thought to occur because the plastic film used as the base film of the adhesive film acts as a barrier layer for trace gases generated between the adhesive layers, so there is no place for the gas to escape, and blisters occur as spots of gas bubbles. It will be done.

Therefore, it may be possible to eliminate the blister condition by interposing a ventilation layer made of paper or porous polyurethane between the film and the adhesive layer, but this method reduces the total thickness of the adhesive sheet. In addition to being thicker, the film loses transparency and cannot be used as a window material film.

Also, is it clear that rubber-based adhesives made of styrene-isoprene-styrene block copolymers or styrene-butadiene-styrene block copolymers have anti-blister properties in certain formulations? Since these are all rubber-based, they have the disadvantage that the weather resistance of the adhesive layer portion is poor, making them unsuitable as window materials.

[Problems to be Solved by the Invention] The present invention provides an adhesive film that is used when attaching a film having a sunlight adjustment function to a plastic window material.
The object of the present invention is to provide an adhesive film that prevents the occurrence of blisters and has excellent adhesive strength and weather resistance.

[Means for Solving the Problems] The present inventors have conducted extensive research to develop an adhesive sheet with excellent blister resistance that is used when attaching a film with a sunlight adjustment function to a plastic window material. , focused on the fact that blisters are caused by trace gases generated from inside the plastic window material resin, and created an adhesive composition containing acrylic acid ester monomer units, polar acrylic monomer units, polymer chains, and polymerizable terminals. By using a copolymer whose main component is a macromonomer unit having a functional group in a predetermined ratio and having a specific molecular weight and glass transition temperature, it can be introduced as a side chain into the copolymer. It was discovered that the polymer chains in the macromonomer units prevented the occurrence of blisters, and good adhesion and adhesive retention were obtained, achieving the above objectives.Based on this knowledge, the present invention was completed. I ended up doing it.

That is, the present invention comprises (A) 50 to 85% by weight of acrylic acid ester monomer units, (B) 30% by weight of a polar acrylic monomer at a single position, and (C) a macro having a polymer chain and a polymerizable functional group at the end. It consists of 5 to 40% by weight of monomer units, the weight ratio of the (B) unit to the (C) unit is 0.02 to 6, and the weight average molecular weight is 150,000 to 2.
A plastic window material adhesive film made by applying an adhesive composition mainly composed of a copolymer with a glass transition temperature of 160 to 60°C to one side of a plastic film having a solar control function, and the above-mentioned adhesive film. The present invention provides a plastic window material that has a solar control function attached to it.

The present invention will be explained in detail below.

Examples of base films for plastic films with sunlight adjustment functions include polyester, polyvinyl chloride,
A sheet or film made of synthetic resin such as polypropylene, polyethylene, or polyurethane, or a cellulose sheet or film can be used. Depending on the use, these base sheets may be provided with printing of appropriate characters or designs or a scratch-resistant surface protection layer on the surface on which the adhesive composition is not applied.

Methods for imparting sunlight adjustment functions to the above base film include methods of coloring the base film with organic or inorganic dyes, metallizing the film (metallizing), Although there are methods of incorporating a substance that blocks light rays inside or on the surface, a metallized film is the best for efficiently controlling sunlight. As the metal to be metallized, aluminum, chromium, gold, etc., or oxides such as tin, silicone, titanium, indium, zirconium, etc. can be used, but aluminum is preferable because of its ease, low cost, and solar control effect. Vapor deposition is particularly preferred. For the metallization, ordinary metallizing methods for plastic films such as vacuum evaporation, cathode sputtering, and ion blasting can be used.

The thickness of the film with solar control function is usually 5pm-1
00pm, especially 25. A range of um to 75 μm is suitable.

The copolymer which is the main component of the adhesive composition applied to the film having a solar control function is composed of the above-mentioned (A) acrylic acid ester monomer unit, (B) polar acrylic thread unit, and (C) macro It consists of monomer units.

Examples of the (A) unit, that is, an acrylic acid ester monomer unit, include an acrylic acid alkyl ester unit and a methacrylic acid alkyl ester unit in which the alkyl group has 1 to 14 carbon atoms. The seven polymers constituting such an acrylic acid ester monomer unit include acrylic acid or methacrylic acid and carbon atoms of 1 to 14 carbon atoms.
Alcohols such as methanol, ethanol, n-propanol, imbutanol, n-butanol, imbutanol, n-pentanol, 2-pentanol, 3-
Pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-methyl-1-pentanol,
2-Methyl-1-/<butanol, 3-methyl-1-pentanol, 2ethyl-1-butanol, 3,5.5-
Trimethyl-1-hexanol, 3-heptatool, 2
Mention may be made of esters obtained from ethylhexanol, n-decanol, n-dodecanol, and the like. Among these acrylic acid ester sevenmers, n-butyl acrylate and 2-ethylhexyl acrylate are preferably used. Moreover, each of these seven types may be used alone, or two or more types may be used in combination.

The monomer constituting the (B) unit of the co-Ti combination, that is, the polar acrylic thread unit, includes polar groups such as carboxyl group, hydroxyl group, amine group, amide group, epoxy group, anano group, isocyanate group, etc. Examples include acrylic tertiary groups having one or two or more groups of at least one type selected from among them. Examples of such polar acrylic salts include (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, 2-aminoethyl (meth)acrylate, (meth)acrylamide, and glycidyl (meth)acrylate. , (meth)acrylonitrile, 2-isocyanoethyl (meth)acrylate, itaconic acid, maleic acid, etc., having polar groups,
Among the copolymers, those in which the polar group is present as a side chain can be mentioned. These polar acrylic monomers may be used alone or in combination of two or more.

The (C) unit of the copolymer, that is, the macromonomer unit, has a polymer chain and a polymerizable functional group at the end, and the polymer chain includes, for example, a styrene unit, a methyl methacrylate unit, or A copolymer chain consisting of these units and 50 mol% or less of acrylonitrile units, vinyl acetate units, etc. can be mentioned. This polymer chain has a molecular weight of 1000
~30,000 and the glass transition temperature is 30'O
The above are preferred.

Further, the polymerizable functional group is not particularly limited as long as it is a functional group that can be copolymerized with the above-mentioned acrylic acid ester monomer or polar acrylic monomer. Examples of such polymerizable functional groups include methacryloyl groups, allyl groups, and vinylbenzyl groups.

By copolymerizing such a macromonomer having a polymer chain and a polymerizable functional group at the end with the above-mentioned acrylic acid ester monomer and polar acrylic monomer, the polymer chain in the macromonomer can be formed as a branch component. A graft copolymer having the following properties can be easily obtained. The copolymer develops its blister-resistant effect because the polymer chains of its branch components absorb trace gases generated by the resin adherend.

There are no particular restrictions on the method for producing the macromonomer, and various known methods may be used, such as (1) first producing a lipping polymer anion constituting the polymer chain portion of the macromonomer, and adding methacryl chloride or the like to this. (2) Polymerize a radically polymerizable functional group such as methyl methacrylate in the presence of mercaptoacetic acid as a chain transfer agent to obtain an oligomer having a terminal carboxyl group, and then macromonomerize with glycidyl methacrylate. (3) A method in which an oligomer having a terminal hydroxyl group is obtained using mercaptoethanol as a chain transfer agent, and then macromonomerized with hydroquine ethyl methacrylate; (4) A mercaptan chain transfer agent containing a polymerizable functional group. (5) Using vinyl phenylketene methyltrimethylsilyl acecool as a polymerization initiator and a fluorine compound as a co-catalyst, a vinyl thread polymer having a carbonyl group or a cyano group is produced. Any method such as ionic polymerization can be used.

Regarding the content ratio of each unit of the copolymer in the present invention, (A) acrylic acid ester monomer unit or 50
~85% by weight, (B) polar acrylic yarn upper unit is 1
~30% by weight and (C) macromonomer units are 5-40
It is necessary that the weight ratio of the (B) units to the (C) units be within the range of 0.02 to 6. If the content of each unit deviates from the above-mentioned range, the copolymer will have poor blister resistance or adhesive performance, and the object of the present invention will not be fully achieved.

Further, in the present invention, the weight average molecular weight of the copolymer must be in the range of 150,000 to 2,000,000, preferably 250,000 to 1,500,000, and more preferably 300,000 to 1,000,000. If the weight average molecular weight is less than 150,000, the adhesive's holding power may be low, while if it exceeds 2,000,000, the workability of coating etc. tends to deteriorate.

Furthermore, the glass transition temperature of the copolymer is 60 to 60°C,
Preferably, the temperature needs to be in the range of -30 to 20°C. If the glass transition temperature is less than 160°C, the adhesive force will not be sufficient, and if it exceeds 60°C, the ball tack will tend to decrease.

The method for producing the copolymer in the present invention includes, for example, (
1) Simultaneously copolymerizing an acrylic acid ester monomer, a polar acrylic monomer, and a macromonomer having a polymer chain and a polymerizable functional group at the end in the presence of a radical polymerization initiator such as azobisisobutyronitrile. Method, (2) First, an acrylic acid ester monomer,
For example, copolymerizing with a polar acrylic seventh polymer having a reactive group such as a carboxyl group or a hydroxyl group to produce a copolymer having a reactive group in the side chain, and then bonding with the reactive group. For example, a method in which a macro segment consisting of a polymer chain having a terminal reactive group such as an isocyanate group, a hydroxyl group, or a carboxyl group is reacted with a monomer having a graft initiation reactive group, such as a polymerizable organic peroxide and an acrylic ester. After copolymerizing the system monomer and the polar acrylic seventh monomer, styrene,
A method of graft copolymerizing monomers such as methyl methacrylate and acrylonitrile can be used.

In methods (2) and (3) above, the copolymerization reaction of an acrylic acid ester monomer, a polar acrylic 7th monomer, and a macromonomer is not utilized, but the resulting copolymer does not have its final structure. is the same as that produced by method (1), and falls within the concept of a copolymer according to the present invention.

According to the research conducted by the present inventors, styrene units, methyl methacrylate units, etc. can be copolymerized by simply copolymerizing 7-mers such as styrene and methyl methacrylate with acrylic acid ester monomers and polar acrylic 7-mers. The blister resistance that is the objective of the present invention cannot be achieved by simply blending ordinary polystyrene, polymethacrylate, or other resins with a copolymer of an acrylic acid ester monomer and a polar acrylic monomer. No effect will be obtained.

From these facts, in the copolymer according to the present invention,
The side chain polymer chains constitute microdomains in the copolymer, and the microphase separation structure is effective in absorbing and diffusing trace gases generated from resin adherends that cause blisters. Seem.

The adhesive film of the present invention is prepared by applying an adhesive composition containing the copolymer obtained as described above as a main component to the surface of a base film according to a conventional coating method. be able to. In addition, in order to further improve the durability of the adhesive film, we use UV absorbers,
Anti-aging agents such as antioxidants can also be added.

The present invention also includes a plastic window material having a solar control function, in which the above film having a solar control function is attached to a plastic window material using a blister-resistant adhesive. The plastic window material used in the present invention is a transparent plastic material, and among these, acrylic resin plates such as polycarbonate resin plates and polymethyl methacrylate resin plates are particularly suitable for use as window materials. It is a molded product made of styrene resin with good transparency. When an adhesive film is attached to a polycarbonate resin board for windows or a polymethyl methacrylate resin board for the purpose of controlling sunlight, the occurrence of blisters is particularly noticeable.

Therefore, the adhesive film of the present invention is particularly effective when applied to such resin molded products for window materials.

To apply a film with solar control function to these plastic window materials, you can apply the film while spraying water onto the window, or use a laminator, just as you would apply it to a regular glass window. .

In the case of a metal vapor deposited film or a film with a colored surface, the vapor deposited layer or the colored layer is usually coated with an adhesive and then laminated onto the plastic window material, but the vapor deposited layer or the colored layer may be exposed to the surface and then laminated.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these examples.

In addition, each physical property was calculated|required according to the method shown below.

(1) Viscosity Using a BM type viscometer manufactured by Tokyo Keiki, in an atmosphere of 23°C, No.
, 40-tar 6Orpm. Values are expressed in centipoise.

(2) CCP800 manufactured by Tosoh Corporation using molecular weight THF as the fluid phase
0 Measured using a GPC device, and the weight average molecular weight (molecules) is shown using polystyrene as a standard material.

(3) Adhesive strength JIS Z-02371: 1 after 24 hours of pasting
The peel adhesive strength was measured at 80° C. and expressed in grams per 25 mm width.

(4) Holding force Measured according to JIS Z-0237 at 40° C. under a load of 1 kg, and expressed in seconds until falling.

(5) Glass transition temperature Reovipron DDV-II manufactured by Orientic Co., Ltd.
-Measurement was made using the new method using EP at 3.5 Hz.

(6) Total light transmittance and haze Haze meter manufactured by Suga Test Instruments Co., Ltd. Measured by HGM-2K.

In addition, each abbreviation in the table means the following.

2EHA 2-Ethylhexyl niacrylate BA Butyl niacrylate AA Niacrylic acid HEMA: 2-Hydroxyethyl methacrylate ΔN-6
= Methacryloyl-terminated poly(styrene-acrylonitrile copolymer) (Nialon macromonomer AN-6 manufactured by Toagosei Co., Ltd.) C-4500: Methacryloyl-terminated polystyrene (manufactured by Sartomer Corporation: Chemlink C-4500) Adhesive Production Example A Reflux condenser, Equipped with nitrogen inlet pipe, thermometer, and stirring blade 5
00mQ 4 people In a flask, 80g of 2-ethylhexyl acrylate, 3g of acrylic acid, methacryloyl-terminated styrene-acrylonitrile copolymer (product name: AN-6)
[Manufactured by Toagosei Co., Ltd.]) 179, a, a'-azobisisobutyronitrile 0.539 and 230 g of ethyl acetate were added, stirred for 30 minutes under a nitrogen stream, then heated to 60°C and left as is. The reaction was allowed to proceed for 24 hours.

The obtained polymer solution was transparent, had a viscosity of 3,000 cps at a concentration of 35% by weight, and a weight average molecular weight of 680,000.

Table 1 shows the charging composition of Nanatsuma and the physical properties of the polymer.

Adhesive Production Examples B, C, and D Adhesives were produced in the same manner as in Example 1, except that the composition of the seven pots was changed as shown in Table 1.

Table 1 shows the raw material composition of the nanatsuma and the physical properties of the polymer.

Adhesive Production Comparative Examples was manufactured.

Table 1 shows the monomer charge composition and the physical properties of the polymer.

(Left below) Example 1 A polymer solution of adhesive A was applied to a 25 μm thick aluminum deposited polyester film with a total light transmittance of 42% and a haze of 4.7% to a thickness of 20 μm to form an aluminum deposited polyester adhesive. The film was prepared and attached to a polycarbonate plate to obtain a window material. The adhesive strength after 24 hours of application was 420 g and 725 mm, indicating strong adhesion. Moreover, the holding force was 70.000, and there was no deviation.

Next, the obtained window material was left to stand at 80 degrees for 24 hours and weather conditioner for 9,100 hours to conduct an accelerated deterioration test. The results are shown in Table 2.

Examples 2 to 4 and Comparative Example 1 Example 1 except that the adhesive was replaced with B, C, D, X, and Y
A polycarbonate plate window material was prepared in the same manner as in Example 1, and the same accelerated deterioration test as in Example 1 was conducted. The results are shown in Table 2.

Example 5 Total light transmittance 33%, colored bronze with dye,
A window material was obtained by applying adhesive A of the adhesive production example to a thickness of 20 μm on a polyester film having a haze of 3.3% and having a thickness of 25 μm.The resulting adhesive film was attached to a methyl methacrylate resin board to obtain a window material. . The obtained window material was subjected to the same accelerated deterioration test as in Example 1, and the results shown in Table 3 were obtained.

Comparative Example 2 A methyl methacrylate resin plate was prepared in the same manner as in Example 5 except that the adhesive was replaced with X, and the same accelerated deterioration test as in Example 5 was conducted. The results are shown in Table 3.

(Left below) As is clear from the results in Tables 2 and 3, Examples 1-
The window material of Example 5 showed no abnormality in appearance even after the accelerated deterioration test.
Transparency also remained unchanged from the initial state. In comparison, in Comparative Examples 1 and 2, in which adhesives not included in the present invention were used, blisters were generated on the surface of the adhesive layer, resulting in significantly poor transparency, making it impossible to see through the opposite side of the window material. Ta.

[Effect of the invention] By using a specific copolymer in the adhesive layer, the adhesive film having a solar control function of the present invention can be attached to a transparent plastic plate without causing poor appearance or poor adhesion due to blistering. This makes it possible to efficiently and economically produce plastic window materials that strongly adhere to films and have excellent transparency, sunlight control functions, and weather resistance.

Claims (1)

[Claims] 1. On the surface of a plastic film having a sunlight adjustment function, (A) 50 to 85 acrylic acid ester monomer units.
(B) 30% by weight of a single position of a polar acrylic monomer; (C) 5% to 40% by weight of a macromonomer unit having a polymer chain and a polymerizable functional group at the end;
An adhesive whose main component is a copolymer with a weight ratio of units (B) to units C) of 0.02 to 6, a weight average molecular weight of 150,000 to 2 million, and a glass transition temperature of -60 to 60°C. An adhesive film for plastic window materials made by applying a composition. 2. The adhesive film according to claim 1, wherein the plastic film having a sunlight adjustment function is a colored film or a metallized film. 3. A plastic film having a solar control function was placed on a transparent plastic plate, containing (A) 50 to 85% by weight of acrylic acid ester monomer units, (B) 30% by weight of a single position of polar acrylic monomer, and (C) polymer chains and It consists of 5 to 40% by weight of macromonomer units having a polymerizable functional group at the terminal, the weight ratio of the (B) units to the (C) units is 0.02 to 6, and the weight average molecular weight is 150,000 to 2.
1,000,000, a solar control plastic window material to which a composition mainly composed of a copolymer with a glass transition temperature of -60 to 60°C is attached as an adhesive. 4. The plastic window material according to claim 3, wherein the transparent plastic plate is a polycarbonate resin plate, an acrylic resin plate, or a polystyrene resin plate.