JPS5844101B2 - Heat-sensitive double-sided adhesive film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-sensitive double-sided adhesive film comprising a heat-sensitive adhesive layer formed on a release material.

Conventionally, combinations of this type of heat-sensitive adhesive and release material have been considered.

The low peel strength of release paper near room temperature is important for improving the workability of adhesive work, and when one side is thermocompression bonded to an object to be bonded, it is coated to protect the other side. It is undesirable for the release material to peel off.

However, in systems with low peel strength around room temperature, the release paper will peel off when heated, and in systems where release paper does not peel off under heating, the peel strength around room temperature will be high. Therefore, there has been a desire for a combination of a heat-sensitive adhesive and a release material that satisfies the required properties both near room temperature and under heating.

The present invention was invented in view of these circumstances, and the weight ratio of styrene/butadiene is 25/75 to 45.
155, a copolymer of polystyrene and polybutadiene with an average molecular weight of 50.000 to 300,000.
Teleblock copolymer with a softening point of 110-150℃
A heat-sensitive adhesive layer mainly composed of a mixed composition with a terpene phenol resin and having a mixing ratio of the terpene block copolymer/terpene phenol resin of 35/65 to 65/35 is peeled off from a polyolefin. This is probably related to a heat-sensitive double-sided adhesive film characterized by being formed on a material.With this structure, the peel strength of the release material is low near room temperature, but the release material does not fall off under heating. , It becomes possible to perform processing such as alumite processing and punching after lamination.

Next, the usage pattern of the heat-sensitive double-sided adhesive film according to the present invention will be explained.

The heat-sensitive double-sided adhesive film according to the present invention is effectively used in a series of processing steps for aluminum decorative boards described below.

The processing procedure for aluminum decorative plates consists of polishing → printing → punching → bending and drawing → alumite processing, and the decorative aluminum plates processed in this way are bonded to a base material such as plastic.

For this adhesion, the heat-sensitive double-sided adhesive film according to the present invention is used, and this adhesive film is laminated to the aluminum plate during the processing steps of the aluminum decorative board, for example, between the printing step and the punching step, and After undergoing the alumite processing through the bending and drawing process, the release paper of the adhesive film is peeled off and the aluminum decorative plate is adhered to a base material such as plastic.

In this case, the above-mentioned alumite processing generally consists of degreasing with NaOH, anodizing, coloring, and sealing at 100°C or higher, but during this heating process, the release paper separates from the adhesive film. It peels off, and the treatment liquid adheres to the adhesive film surface, reducing the adhesive strength.

However, with the adhesive film of the present invention, such a situation does not occur, and it has been found that the peeling force (peel strength) of the release paper at around room temperature is as low as about 10 to 1000 g15α.

In the present invention, it has been found that the following combinations of heat-sensitive adhesive and release material are excellent.

That is, as an adhesive, (a) the weight ratio of styrene/butadiene is 25/75;
~45155, and a teleblock copolymer of polystyrene and polybutadiene having an average molecular weight of 50,000 to 300,000.

and (b) a turpentine phenol resin with a softening point of 110-150°C.

The main component is a mixed composition of
It is preferable to use one having a ratio of ˜65/35.

In this case, the average molecular weight of the teleblock copolymer is 5
If it is less than 300,000, the cold resistance and heat resistance tend to decrease, and if it exceeds 300,000, the adhesive strength tends to decrease.

Further, if the mixing ratio of the teleblock copolymer/terpene phenol is less than 35/65, the cold resistance and heat resistance will tend to decrease, and if it is higher than 65/35, the adhesive strength will tend to decrease as well.

In addition, if the softening point of the above-mentioned terpene phenol is less than 110℃, the adhesive strength to the release material will be high, making it difficult to peel off the release material (poor workability), and if it exceeds 150℃, it will be difficult to peel off the release material (poor workability). The adhesive strength of the adhesive decreases, making it easier for the release material to peel off.

Further, as the release material, a polyolefin film such as polyethylene or polypropylene may be used, but a polypropylene film is preferable.

More preferably, a biaxially stretched polyolefin film is used.

In addition, when the above-mentioned release material is used in a series of processing of the above-mentioned aluminum decorative board, etc., it is preferable that the thickness is within the range of 20 μm to 100 μm.

In this case, if the thickness is less than 20 μm, the release material does not have sufficient stiffness, making it difficult to peel off the release material and resulting in poor workability.

Moreover, if the thickness exceeds 100 μm, workability such as bending and punching will deteriorate.

Teleblock copolymers of polystyrene and polybutadiene that can be used in the present invention include radial type and linear type.

Radial types include Trubulen 406 (average molecular weight approximately 210,000, butadiene/styrene = 60/40) and Trubulen 411 (average molecular weight approximately 280,000, butadiene/styrene - 70/30) manufactured by Phillips Oil Co., Ltd.
), Trubulen 414 (average molecular weight approximately 150,000, butadiene/styrene-60/40).

In addition, as a linear type, Kaliflex TR1101 manufactured by Shell Chemical Co., Ltd. (average molecular weight approximately 100,000,
butadiene/styrene 70/30) and Cariflex TR1102 (average molecular weight approximately 70,000, butadiene/styrene 0/30).

The molecular structure of the radial type teleblock copolymer is
The polybutadiene ends of the block copolymer of polystyrene and polybutadiene are bonded to each other with a binder,
An average of three or more polybutadiene segments having a polystyrene segment on the opposite side are bonded to each binder.

The molecular structure of the linear type teleblock copolymer is such that polystyrene segments and polybutadiene segments are alternately bonded in a linear manner.

In addition, as the terpene phenol resin that can be used in the present invention, YS Polyster T manufactured by Yasushi Oil Industries Co., Ltd.
115 (average molecular weight about 720, softening point about 115°C), y
s Polyster T130 (average molecular weight approximately 760, softening point approximately 130°C), YS Polyster 8145 (average molecular weight approximately 1
050, softening point 1458C).

It is believed that this terpene phenol resin acts to impart tackiness to the adhesive.

The above-mentioned terpene phenol resin is a copolymer resin having a chirhen/phenol molar ratio within the range of 1.0 to 3.0.

Here, terpenes are, for example, monoterpenes having 10 carbon atoms, such as α-pinene, β-pinene, camphene, myrcene, dipentene, β-phelandrene, Δ3-carene,
It includes sapinene, ocimene, α-terpinene, etc., including hydrogenated versions thereof, and shows particularly good performance when α-pinene is used.

Note that it is desirable that an anti-aging agent is further added to the adhesive composition according to the present invention in order to impart durability.

This anti-aging agent is 0% per 100 parts by weight of the adhesive composition.
．． It can be added in the range of 1 to 2 parts by weight, and 2,5-di-
t-Butylhydroquinone (product name: ANTAGE DBH, manufactured by Kawaguchi Chemical Co., Ltd., product name: ANTAGE D, manufactured by Monsanto Chemical Co., Ltd.), 2,5-di-t-butylhydroquinone (product name: ANTAGE D, manufactured by Kawaguchi Chemical Co., Ltd.)
AH, manufactured by Monsanto Chemical Company, product name: Santoba-A)
, 2,2'-methylene-bis(4-methyl-6-1-butylphenol) (Kawaguchi Chemical Co., Ltd., product name: ANTAGE W-400, Peyer AG, product name: Antioxidant BKF), 4,4 '-thiobis(6-
1-butyl-m-cresol) (product name: Antige Crystal, manufactured by Kawaguchi Chemical Co., Ltd.; product name: Santonox R, manufactured by Sensanto Chemical Co., Ltd.), 2,2'-methylene-bis(4-ethyl-6-t) -butylphenol) (
Manufactured by Kawaguchi Chemical Industry Co., Ltd. Product name: ANTAGE W-500
．． Peyer AG product name: Antioxidant 4
25) can be used.

Further, by mixing short fibers into the adhesive composition of the present invention, the adhesive layer can be easily cut during punching or cutting.

In addition, Japanese paper or nonwoven fabric is impregnated with the adhesive according to the present invention,
It can also be used as an adhesive layer.

Next, the present invention will be explained in more detail with reference to examples, but the following examples are for illustrative purposes only and are not intended to limit the present invention, and further modifications are made based on the technical idea of the present invention. It will be understood that this is possible.

Example 1 An adhesive solution having the following composition was prepared.

This adhesive solution was coated on a biaxially oriented polypropylene film with a thickness of 50μ, and dried to a thickness of 30 to 70μ.
For example, a heat-sensitive adhesive film with a heat-sensitive adhesive layer of about 40 microns was fabricated.

The adhesive film thus obtained was laminated on a 500 μm thick aluminum plate at a temperature of 120° C. and cut into a 50 mm width.

Then, the strength when the polypropylene film is peeled off at a tensile speed of 300 peaks per minute is defined as the OPP peel strength, and the peeled surface of the polypropylene film is applied to the high impact styrene surface used as the molding resin.
The adhesive strength was determined by A13/S, which was determined by measuring the peel strength in the 90° direction at a speed of 20 per minute after adhering under the adhesive condition of 3 kg/crlt for io seconds.

In this example, at the initial stage when the adhesive film was laminated to the aluminum plate, the OPP peel strength was 20 g 15 cm.

kl/S, adhesive strength 10kg15cIrL,
Also, after alumite treatment, OPP peel strength is 40 g156rfLA1/S
t Adhesive strength: 9 kg 75 cm, the adhesive strength under heating was high, and the peel strength of the film was also good.

Example 2 An adhesive solution having the following composition was prepared.

This adhesive solution is then coated on the polypropylene film side of a composite film made by laminating a 20μ thick polypropylene film and a 25μ thick polyester film, and dried to form a heat-sensitive adhesive layer approximately 60μ thick. A heat-sensitive adhesive film was produced.

Next, the peel strength and adhesive strength were measured in the same manner as described in Example 1. At the initial stage of lamination on the aluminum plate, the OPP peel strength was 50g15crrLAll/S.
1 Adhesion strength is 9kg15crfL, and after alumite treatment, OPP peel strength is 100g15crrLAAll/S
, the adhesive strength was 8 kg75 cm, and similar good results as in Example 1 were obtained.

Example 3 An adhesive solution having the following composition was prepared.

Japanese paper with a thickness of 50μ was impregnated with this adhesive solution, which was then laminated onto an OPP film with a thickness of 50μ and dried to produce a heat-sensitive adhesive film having a heat-sensitive adhesive layer with a thickness of about 150μ.

Then, when the peel strength and adhesive strength were measured in the same manner as described in Example 1, the OPP peel strength was 30g15crfLA 11/
S, adhesive strength was 12kg15crn, and after alumite processing, OPP peel strength was 50g15crnAl/St adhesive strength was 11kg15cm, and the results were still good.

Examples 4-23 In these examples, Antige W-
An adhesive solution containing 1 part by weight of 400 and 180 parts by weight of toluene and the teleblock copolymer and terpene phenol resin (numbers are in parts by weight) listed in the table below was prepared.

The results are also listed in the table below, together with the peel strength and adhesive strength. OPP peel strength is the peel strength of the polypropylene film at room temperature, and OPP peel strength ■ is the peel strength of the polypropylene film at room temperature after boiling for 1 hour. , the adhesive strength I is the adhesive strength of the adhesive layer at 20℃ after bonding the aluminum plate laminated with the adhesive layer to the acrylic resin surface at 100℃, and the adhesive strength ■ is the adhesive strength of the aluminum plate laminated with the adhesive layer. 1 on the acrylic resin surface
Each figure represents the adhesive strength of the adhesive layer at 80°C after adhesion at 00°C.

From the results stated in the above table, especially Examples 5-7゜12-1
It can be seen that in Examples 7, 22, and 23, the peel strength at room temperature is low and the workability is improved, and it is also found that the adhesive strength at room temperature and under heating is maintained at a high level throughout each example.

Claims (1)

[Claims] 1 Styrene/butadiene weight ratio is 25/75 to 45
155, a copolymer of polystyrene and polybutadiene with an average molecular weight of 50,000 to 300,000
Teleblock copolymer with a softening point of 110-150℃
A heat-sensitive adhesive layer mainly composed of a mixed composition with terpene phenol resin and having a mixing ratio of terpene block copolymer/alpene phenol resin of 35/65 to 65/35 is peeled off from polyolefin. A heat-sensitive double-sided adhesive film formed on a material.