JPH03132346A - Double-layer type hot melt film - Google Patents

Abstract

PURPOSE:To contribute to the automation of a side screen bonding process by combining low crystalline and high crystalline thermoplastic saturated polyester resin layers to laminate both layers to a film base material layer composed of a resin selected from polyvinyl chloride and polyurethane. CONSTITUTION:Low crystalline and high crystalline thermoplastic saturated polyester resin layers are combined to be laminated to a film base material layer composed of a resin selected from polyvinyl chloride and polyurethane to constitute a double-layer type hot melt film. The film base material layer may be appropriately selected but, since the function thereof resides in the impartment of film physical properties, it is proper to provide strength of 50 kg/cm<2> or more, elongation of 200/% or more and a softening point of 150 deg.C or higher to the film base material layer in usual. The thermoplastic saturated polyester resin is a random copolycondenste of at least one of aromatic dicarboxylic acid and aliphatic dicarboxylic acid and at least one of glycols and low crystalline and high crystalline ones are used in distinction from each other.

Description

[Detailed Description of the Invention] The present invention relates to a multilayer hot melt film, more specifically,
It consists of laminating low-crystalline and high-crystalline thermoplastic saturated polyester resin layers on a specific film base layer.
This invention relates to a multilayer hot melt film that has both adhesive properties and film properties.

Prior Art and Problems to be Solved by the Invention Conventionally, hot melt adhesives in the form of films made of various materials such as polyester, or combinations of nonwoven or woven fabrics and thermoplastic resins, thermosetting resins, or adhesives have been used. Adhesive films or tapes are used everywhere,
well known. However, these film or tape adhesives are intended only for adhesive function, and physical properties such as strength and elongation of the film (or tape) are not taken into consideration.

On the other hand, heat-sealable films such as polyethylene and polypropylene are known, but their range of use is limited due to their lack of heat resistance, and they cannot be expected to have good adhesion to various coatings or to metals, glass, etc. This has not yet been widely used as a hot melt film.

Incidentally, there are a number of holes in the steel plate on the instrument panel side of the door bag portion of an automobile due to the necessity for interior parts such as speakers, or for the necessity of work when repairing interior parts. However, if this hole remains as it is, there is a risk that rainwater that travels through the window glass and enters the door bag when the vehicle is running will seep into the interior through the hole. For this reason,
The holes are entirely covered with a film made of polyvinyl chloride, polyethylene, etc. using a butyl adhesive.

This film is what is called an inside screen.

Furthermore, automobile manufacturing lines are becoming increasingly automated and unmanned through the introduction of robots and the like. However, in the process of attaching the inside screen, first a butyl-based adhesive is applied and then the adhesion is performed, but these steps are still usually done manually.

The present inventors developed a function-intensive hot melt film that combines the adhesive properties of a butyl-based adhesive and the physical properties of polyvinyl chloride, etc., since the attachment of the above-mentioned inside screen contributes to automation and unmanned processes. After conducting extensive research with the aim of providing this product, we found that if a combination of low-crystalline and high-crystalline thermoplastic saturated polyester resin layers were laminated on a specific film base layer, the film base layer could improve the film's physical properties. The low-crystalline thermoplastic saturated polyester resin can provide adhesion, and the high-crystalline thermoplastic saturated polyester resin can provide increased strength and surface tack prevention, resulting in the desired multilayer pot melt film. This discovery led to the completion of the present invention.

Structure and Effects of the Invention Namely, the present invention is characterized in that a layer of a thermoplastic saturated polyester resin of low crystallinity and high crystallinity is laminated in combination on a film base layer selected from polyvinyl chloride and diurethane. The present invention provides a multilayer hot melt film characterized by comprising:

The film base layer in the present invention may be appropriately selected from polyvinyl chloride and polyurethane films, but since its function is to impart physical properties to the film, it usually has a strength of 50 to 9/cm" or less. It is appropriate that the material has physical properties of elongation of 200% or more and softening point of 150°C or more (preferably 200°C or more).The thickness of the core layer is
Usually, it is sufficient if it is set to 0.05 to 1 Omm.

The thermoplastic saturated polyester resin in the present invention refers to aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, trimellitic acid, paraoxybenzoic acid, etc.) and fatty acid dicarboxylic acids (succinic acid, etc.). , adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosa, nnic acid, ε-caprolactone, etc.) and glycols (ethylene glycol, propanediol, propylene glycol, !, 4-butanediol, 1. 5-bentanediol, l,6-hexanediol, diethylene glycol, neopentyl glycol, polyethylene glycol, polytetramethylene glycol, l,4-cyclohexane dimetatool, trimethylolpropane, pentaerythrol, etc.) It refers to random cocondensation polymers with low crystallinity and high crystallinity. Here, the low-crystalline thermoplastic saturated polyester resin contributes to imparting desired adhesion, so it usually has a molecular i of 5,000 to 30,000 (preferably 8,000 to 25,000) and a hardness (Noyoa A) of 70 or less (preferably 20 to 25,000). 50), a glass transition point of 10°C or less, and a softening point of 80 to 200°C (preferably 100 to 1
It is suitable that the material has a physical property value of 50'C). on the other hand,
Highly crystalline thermoplastic saturated polyester resin usually has a molecular weight of 1.
0000-50000 (preferably 15000-300
00), hardness (Soyoa D) of 20 or more (preferably 20-
70), softening point 100-200°C (preferably 120-200°C)
160° C.).

The multilayer hot melt film according to the present invention has a layer of a low crystalline thermoplastic saturated polyester resin (hereinafter referred to as a low crystalline polyester layer) and a layer of a highly crystalline thermoplastic saturated polyester resin on the film base layer. By laminating a combination of layers (hereinafter referred to as high-crystalline polyester layers), for example, one low-crystalline polyester layer and one high-crystalline polyester layer are sequentially laminated, or one low-crystalline polyester layer and one low-crystalline polyester layer are further laminated thereon. It is constructed by sequentially laminating a crystalline polyester layer and a highly crystalline polyester layer. Lamination may be performed according to a normal method. The thickness of each low-crystalline polyester layer to be laminated is usually 0.01=1.0 mm, and the thickness of each high-crystalline polyester layer is usually 0.01 mm.
It is sufficient if it is set to −1.0 mm.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 (1) Film base layer polyurethane emulsion (manufactured by IC1, NEOLETSU
R-9618, 2.0% acrylic thickener (manufactured by Rohm & Haas, Experimental Rheology Modifier-EXP-300) for solid content 40% (weight %, same hereinafter) was added to make the emulsion thickness (20°C) 1000 cps.

This viscosity-adjusted polyurethane emulsion was uniformly applied to a thickness of 0.25 mm on release paper, and force-dried at 100°C for 2 minutes to form a polyurethane film layer with a thickness of 0.1 mm (strength: 137 kg/cx", elongation: 550%). , softening point 210°C).

(2) Multi-layer hot melt film On the polyurethane film layer of (1) above, a low-crystalline polyester resin (manufactured by Unitika, Elythyl UE-3
400, molecular weight 25000, Shore A hardness 70, glass transition point -20°C, softening point 105°C) was uniformly applied to a thickness of 0.2 mm using a roll coater, and then heated at 100°C.
A low-crystalline polyester layer with a thickness of 0.1 mm is formed by passing it through a drying oven.

Next, on this low-crystalline polyester layer, a high-crystalline polyester resin (manufactured by Unitika, Erythyl UE-35
00, molecular weight 30000, hardness D 60, softening point 1
A 50% toluene/MEK (]:I) mixed solvent solution at 45°C) was uniformly coated with a thickness of 0.2 mm using a roll coater, and passed through the drying oven again to form a highly crystalline polyester layer with a thickness of 0.2 mm. A multilayer hot melt film consisting of three layers is obtained.

(3) Performance test Adhesion (normal state, 20°C water resistance, 80°C water resistance, cold resistance), heat resistance, and watertightness are evaluated in the following manner.

A multilayer film with an adhesive width of 25mm x length of 50mm was applied to a painted steel plate (
After heat-compression bonding at 150°C for 20 seconds (melamine/alkyd paint), ■Normal condition: Peel off by hand at 20°C.■20°C water resistance = Hand peel off after immersing in 20°C water for 24 hours.■80°C water resistance = After being immersed in water at 80°C for 24 hours, the film was hand-kneaded in an atmosphere at a temperature of 5°C. In all cases, film breakage occurred in cases ① to ①, and the adhesion was good.

Heat Resistance As shown in Figure 1 of the attached drawings, a coated steel plate cut out in a U-shape ++ = G-layered separate film is heat-pressed at 50°C for 20 seconds, then heated to 80°C, 100°C or 120°C. 'C for 24 hours horizontally, and visually observed whether or not the non-crimped part A of the multilayer film 2 retained its shape (whether the non-pressed part A softened and melted in a heated atmosphere). Retention was approved.

Mizumine As shown in Fig. 2, a box-shaped steel plate container (50x50
The container 11 was sealed by thermocompression bonding for 20 seconds at 20° C., and water was placed in the container 11 and allowed to stand in an atmosphere of 20° C. or 80° C. During this time, the presence or absence of water leakage was examined, and no water leakage was found.

Example 2 (1) Film base layer polyvinyl chloride (manufactured by Kanebuchi Kagaku Kogyo Co., Ltd., PCI-12Z)
Plasticizer (ethylhexyl trimellitate) 6 to 100g
09 and kerosene 109 were added and mixed, and then the polyvinyl chloride sol obtained by defoaming was placed on the female pattern paper. Apply uniformly to a thickness of 1mm, bake dry at 200℃ for 2 minutes, and apply to a thickness of 0.0mm.
8am PVC film layer (strength 180 kg
/ax”, elongation 240%, softening point 230°C).

(2) Multilayer hot melt film On the polyvinyl chloride film layer of (1) above, Example i
In the same manner as above, a low crystalline polyester layer with a thickness of Q and Imm and a highly crystalline polyester layer with a thickness of 0 and 1 mm are sequentially formed to obtain a multilayer hot melt film consisting of three layers.

(3) Performance Test Similar to Example 1, adhesiveness (■ to ■), heat resistance, and watertightness were evaluated, and good results were obtained in all cases.

Comparative Example The same low-crystalline polyester resin as in Example 1 (Erythyl UE-3400) was placed on Rouyon nonwoven fabric (manufactured by Okura Paper Valve Co., Ltd., New Soflon A-170, 179/C scraps).
) was applied uniformly to a thickness of 0.2 mm using a roll coater, and passed through a drying oven at 100°C to create a nonwoven fabric film impregnated with polyester resin.

Similar to Example 1, this nonwoven fabric film was tested for adhesive properties (■ ~
(2), heat resistance and watertightness were evaluated, and good results were obtained for both.

As shown in FIG. 3, when the film 22 of Example 1.2 and Comparative Example 1 was used to adhere to an uneven painted surface, the film of Example 1.2 showed good adhesion. However, the film of Comparative Example 1 suffered from tearing.

[Brief explanation of the drawing]

FIGS. 1, 2 and 3 respectively show Example 1.2.
FIG. 3 is a perspective view for explaining test conditions for heat resistance, watertightness, and uneven coating surface adhesion of the target film obtained in Comparative Example 1.

Claims (1)

[Claims] 1. A layer of a low crystalline thermoplastic saturated polyester resin and a layer of a highly crystalline thermoplastic saturated polyester resin are sequentially laminated on a film base layer selected from polyvinyl chloride and polyurethane. A multilayer hot melt film characterized by: 2. The physical properties of the low-crystalline thermoplastic saturated polyester resin are a molecular weight of 5,000 to 30,000, a hardness (Shore A) of 70 or less, a glass transition point of 10°C or less, and a softening point of 80 to 200°C.
The physical properties of the other highly crystalline thermoplastic saturated polyester resin are molecular weight 10,000 to 50,000 and hardness (Shore D).
20 or higher and a softening point of 100 to 200°C. 3. The film base layer has a strength of 50 kg/cm^2 or more, an elongation of 200% or more, a softening point of 150°C or more (preferably 200°C or more), and a thickness of 0.05 to 1.0 mm;
The thickness of the low crystalline thermoplastic saturated polyester resin layer is 0.
2. The multilayer hot melt film according to claim 1, wherein the thickness of the highly crystalline thermoplastic saturated polyester resin layer is 0.001 to 1.0 mm.