JPH0380424B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a vinylidene fluoride resin composite film that has excellent weather resistance, stain resistance, and solvent resistance, and has improved adhesiveness to plastics, rubber, and other base materials. More specifically, it is a vinylidene fluoride resin multilayer film composed of a vinylidene fluoride resin layer, a layer made of a mixture of a vinylidene fluoride resin and a methacrylic ester resin, and a methacrylic ester resin layer. It is related to. (Prior Art) In recent years, polyvinyl chloride-based, polymethacrylate-based, polyfluorine-based films, and the like have been used together with various paints as surface protection films for interior and exterior members. These protective films are used for wallpaper, elevators, vehicle interiors, roofing materials, wall materials, rain gutters, garage roofs, sunrooms, agricultural materials, etc.
It is used in a wide variety of applications, such as signboards, signs, labels, and window glass, due to its excellent weather resistance. By the way, protective films based on the three types of materials mentioned above are used for various purposes depending on their price, characteristics, etc.
In terms of price, the former is cheaper, while in terms of characteristics, the latter has better weather resistance. The target substrates for lamination of these protective films include plastic substrates such as polyvinyl chloride, polycarbonate, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer, FRP, etc., as well as rubber substrates such as EPDM, CSM, etc. ,
In addition to metals such as aluminum foil and steel plates, there is a wide range of materials such as plywood and glass. (Problem to be solved by the invention) However, among these three types of material films, polyfluorine-based films have far superior performance than the two in terms of weather resistance, stain resistance, and strength. On the other hand, it has the disadvantage of poor adhesion to the base material. Therefore, while polyvinyl chloride and polymethacrylic acid ester films use a thermal adhesive method depending on the application, all polyfluorine films use an adhesive method, and in this respect as well. At present, it is expensive and its excellent weather resistance and stain resistance cannot be fully utilized, and there is a strong demand for improvement in imparting this thermal adhesive property. The present invention improves the adhesion of a film made of vinylidene fluoride resin, and includes a vinylidene fluoride resin layer, a layer made of a mixture of vinylidene fluoride resin and methacrylic acid ester resin, and a layer made of a mixture of vinylidene fluoride resin and methacrylic acid ester resin. By using a multilayer film composed of a resin layer, we provide a vinylidene fluoride resin multilayer film that has excellent weather resistance, stain resistance, and solvent resistance, and also has good adhesion to the adhered substrate. be. (Means for solving the problem) The present invention has an A layer containing vinylidene fluoride resin as a component, 85 to 25 parts by weight of vinylidene fluoride resin, and 15 to 75 parts by weight of methacrylic acid ester resin. This is a vinylidene fluoride resin multilayer film characterized by being composed of a B layer and a C layer containing a methacrylic acid ester resin as a component. The vinylidene fluoride resin used in the present invention is
It refers to a homopolymer of vinylidene fluoride or a copolymer of vinylidene fluoride and a copolymerizable monomer. Examples of copolymerizable monomers include vinyl fluoride, tetrafluoroethylene, and trifluorochloroethylene. Next, the methacrylic acid ester resin refers to a copolymer of a homopolymer of methyl methacrylate and a monomer copolymerizable with methyl methacrylate.
Copolymerizable monomers include butyl methacrylate, ethyl methacrylate, and acrylic esters. Next, layer B (hereinafter referred to as B layer) is composed of a mixture of vinylidene fluoride resin and methacrylic acid ester resin.
The raw material used for the layer is a blend of the above-mentioned vinylidene fluoride resin and methacrylic acid ester resin at a certain ratio, or a blend thereof is melted into pellets using an extrusion molding machine or the like. You can use things. The mixing ratio of vinylidene fluoride resin and methacrylic acid ester resin used for this B layer is as follows:
85 to 25 parts by weight/15 to 75 parts by weight, which means that if the vinylidene fluoride resin exceeds 85 parts by weight, the C layer (hereinafter referred to as C layer) containing methacrylic acid ester resin as a component
On the other hand, if the amount of vinylidene fluoride resin is less than 25 parts by weight,
A layer (hereinafter referred to as A layer) containing vinylidene fluoride resin as a component
This is because the adhesion between the two layers becomes insufficient. Note that the film thicknesses of layer A, layer B, layer C, and the entire layer are not particularly specified, but when used as a protective film, layer A is 3 to 100μ, layer B is 2 to 50μ, and layer C is 5μ. ~200μ layer as a whole is 10~
Approximately 350μ is preferable. However, in applications requiring solvent resistance, this is not the case, and even a layer A of several mm thick can be used. On the other hand, it is also possible to use it for the purpose of improving the weather resistance of the base material by imparting light-shielding properties to at least one of the A, B, and C layers. This can be achieved by incorporating fillers and colorants containing talc, calcium carbonate, carbon black, red iron, and other inorganic pigments. In addition, as a method to further improve the weather resistance of the substrate in the form of a transparent film (particularly for the purpose of blocking ultraviolet rays), it is possible to add benzotriazole, benzophenone, salicylic acid derivatives, etc. to at least one of the A, B, and C layers. A method of kneading ultraviolet absorbers is adopted. At this time, it is even more effective to use a radical scavenger or an antioxidant in combination. Next, the manufacturing method will be described. The multilayer film according to the present invention is composed of three layers and is manufactured by melt extrusion. For melt extrusion molding, in addition to a general single-screw extruder, two
Although a screw extruder may also be used, the following methods are available for bonding multiple layers together: First, the T-die coextrusion molding method, in which multiple extruders are used to bond resin in a molten state to form multiple layers, is called a multi-manifold die, and the resin layers are brought into a sheet state and then contacted. There are two methods: adhesion, and a method called feed block die, in which multiple resins are bonded and then spread into a sheet. Multilayer films can also be formed using a method called inflation molding, which uses a round die. This is called the extrusion lamination method, in which one of the layers to be bonded together is formed into a film in advance, and the other layer is extruded while being heated or glued (generally adhesive is applied in advance). It is also possible to use a method of crimping and bonding the material (pre-applied). There is also a method of forming both layers into films in advance and then integrating them using heat or adhesive, but this is disadvantageous in terms of process and cost compared to the previous method, and in the case of thin films, bonding is difficult. It's also difficult. Next, in order to impart light-shielding properties to at least one layer of layer A, layer B, or layer C, it is necessary to add about 2 to 30% by weight of pigment, and the resin and pigment are mixed using an extruder or the like. Melting and kneading may also be used, but in general, the dispersion of the pigment is not sufficient, and using a high-speed rotation, high-shear kneader, such as Kobe Steel's FCM type kneader, will result in very good pigment dispersion and an excellent surface condition. It is possible to provide raw materials for light-shielding layers. (Example) From now on, we will use vinylidene fluoride resin as PVDF,
Methyl methacrylate resin is abbreviated as PMMA. The vinylidene fluoride resin is manufactured by Pennwalt Co., Ltd. under the trade name Kynar 740 (hereinafter abbreviated as K-740), while the methacrylate ester resin is manufactured by Mitsubishi Rayon Co., Ltd. under the trade name Acrypet MD (PMMA, hereinafter referred to as MD). (abbreviated) and manufactured by the same company under the trade name Hypet HBE (methyl methacrylate resin containing acrylic rubber, hereinafter abbreviated as HBE) were used. Also B
The PVDF/PMMA constant ratio mixture used for the layer is
After blending K-740 and MD or HBE at a fixed ratio, the mixture was melted in a 30 m/mφ counter-rotating twin screw extruder and re-pelletized. Example 1 PVDF/PMMA obtained from MD with K-740 as the raw material for the A layer and K-740 as the raw material for the B layer = 80/
20 products, while using HBE as the raw material for the C layer, 40
Three-layer coextrusion molding was carried out using three mmφ extruders, a feed block die, and a coat hanger type T-die with a width of 450 mm and a slit width of 0.3 mm. Note that the take-up roll closest to the T-die was water-cooled. The thickness of the obtained three-layer film was 24μ,
Calculating from the extrusion rate ratio of each extruder, the thickness of each layer was 10 μm for A layer, 6 μm for B layer, and 8 μm for C layer.
In addition, as a result of evaluating the characteristics of this three-layer film,
As shown in Table 1, it had excellent weather resistance, stain resistance, solvent resistance, and thermal adhesion. Example 2 The raw material for the A layer is K-740, and the raw material for the B layer is K-
A PVDF/PMMA=50/50 product obtained from 740 and MD was coextruded into a three-layer film in the same manner using the equipment of Example 1, using MD as the raw material for the C layer. The structure and characteristics of the obtained three-layer film were
Shown in the table. Example 3 The raw material for the A layer is K-740, and the raw material for the B layer is K-740.
The PVDF/PMMA=30/70 product obtained by MD was subjected to three-layer coextrusion molding in the same manner as in Example 1 using HBE as the raw material for the C layer. The structure and characteristics of the obtained three-layer film were
Shown in the table. Example 4 Raw material for A layer is K-740, raw material for B layer is K-740
and PVDF/rubber-filled PMMA obtained from HBE = 60/
40 products were similarly 3-layer coextruded using the equipment of Example 1, using a light-shielding MD prepared by melting and kneading 100 parts by weight of MD and 20 parts by weight of titanium oxide as raw materials for the C layer. I did this. The structure and characteristics of the obtained three-layer film were
Shown in the table. Comparative example 1 PVDF/PMMA obtained from K-740 and MD = 50/
Using 50 products, 65mmφ extruder, width 330mm, slit
A single layer film was formed using a 0.5 mm T-die. The properties of the obtained film are shown in Table 2. Comparative Example 2 PVDF/PMMA=70/ obtained from K-740 and MD
A single-layer film was formed using the same equipment as in Comparative Example 1 using 30 products. The properties of the film are shown in Table 2. Comparative Examples 3 to 4 Characteristics of commercially available methacrylic acid ester resin films and commercially available fluorine resin films were evaluated. The results are shown in Table 2.

【table】

【table】

[Table] The characteristics measurements shown in Tables 1 and 2 were carried out as follows. (1) Film thickness: Measured using a Pico stock thickness gauge with 1/1000mm scale. Furthermore, A and B of the three layers
And the thickness of each layer of C layer was calculated from the extrusion amount ratio of each extruder. (2) Weather resistance (a) Accelerated weather resistance test JISA-1415 (b) Yellowness measurement JISK-7103 Yellowing index = Yellowness after exposure / Initial yellowness (3) Stain resistance (A layer side) 1 Test method 1 Mark approximately ^1cm2 on each film with a magic marker 2 After drying, rub off with gauze 30 times 3 Evaluate the remaining ink with the naked eye 2 Evaluation criteria 1: Completely removed 2: Removed but leaves a thin trace of rubbing 3: 〃 〃 Remains darkly 4: Partially removed, but remains in some areas (marks remain even where it has fallen) 5: Hardly removed (4) Solvent resistance (Immerse only the A layer side) 1 Test method: Each at room temperature After being immersed in a solvent for 2 days, it was visually evaluated. 2 Evaluation criteria ○: No change ○△: Slight film shrinkage △: Film shrinkage △ to ×: Film shrinkage/swelling ×: Film dissolution (5) Thermal adhesiveness (B layer side) 1 Test method Base material: For table cloth Soft PVC sheet 200μ Adhesive roll and conditions Mirror surface/Silicone rubber 100φ×350mm Speed 1m/
Minutes 2 Evaluation method Strength measurement by peeling a 25 mm wide laminated sheet at 180° at a speed of 20 mm/min (effect of the invention) From the vinylidene fluoride resin layer of the present invention, a mixture of vinylidene fluoride resin and methacrylate ester resin The vinylidene fluoride resin multilayer film, which is composed of a methacrylic acid ester resin, has not only high strength and elongation, but also excellent long-term weather resistance, which is a characteristic of vinylidene fluoride resin. It also has excellent stain resistance and solvent resistance, allowing it to be easily removed even if water-based or oil-based ink or dust adheres to it. On the other hand, since the adhesive layer is composed of methacrylic acid ester resin, it has excellent adhesion properties not only using adhesives but also using heat. In addition, it can be applied to coating roofing materials, wall materials, etc.

Claims (1)

[Claims] 1. A layer containing vinylidene fluoride resin as a component;
B containing 85 to 25 parts by weight of vinylidene fluoride resin and 15 to 75 parts by weight of methacrylic acid ester resin.
A vinylidene fluoride resin multilayer film comprising a C layer and a C layer containing a methacrylic acid ester resin as a component.