JP3524902B2 - Class A film bonding adhesive - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive for bonding a type A film.

[0002]

2. Description of the Related Art As is well known, in a membrane roof using a so-called A-type membrane in which a composite resin of PTFE resin (tetrafluoroethylene resin) and glass fiber is coated with a fluororesin such as FEP resin, A It is constructed by stretching the seed membrane. And, in the membrane roof, when the A-type film is weld-bonded to the joint part of the A-type film or the defective part of the A-type film on site, generally, the FEP resin film (100% FEP resin) having a thickness of about 125 to 190 μm is used. Thermal extruded products)
Is used as an adhesive.

The reason why the FEP resin film is used here is to ensure compatibility with the FEP resin used as the surface treatment material for the PTFE resin constituting the resin component of the A-type film material. Further, the thickness of the FEP resin film is determined so that the FEP resin film is melt flowed at the time of welding to ensure a sufficient amount to fill the irregularities on the surface of the A-type film as the adherend.

[0004]

However, when the FEP resin film is used for the adhesive, temporary fixing to the adherend A-type film is complicated, and it is difficult to align the end portions of the film material. However, there is a problem that a defective welding and joining is likely to occur. Further, when the welding and joining failure occurs, after re-heating the peripheral portion including the poorly-adhered portion and peeling off the film material which is the adherend, re-insertion of the FEP resin film and re-welding and joining are repeated, There was a risk that the quality would be extremely unstable.

Further, as a repairing method when partial peeling occurs due to deterioration over time, the above-mentioned reheating of the adherend → peeling of the adherend → reinsertion of the FEP resin film → welding and joining treatment is required. In addition to the complexity, there is a problem that the reliability of fusion bonding is low. The present invention has been made to solve such conventional problems, and its purpose is to be able to easily and uniformly introduce between the films to be bonded, to eliminate welding defects and to improve workability. An object of the present invention is to provide an adhesive for bonding a type A film, which can greatly contribute to the improvement of the above.

[0006]

The invention according to claim 1 is
It is characterized in that it is composed of a gel-like substance in which FEP resin powder is added and dispersed to FEP resin (ethylene tetrafluoride / propylene hexafluoride copolymer resin) disversion. The invention according to claim 2 is the adhesive for bonding a type A film according to claim 1, wherein the center diameter of the FEP resin powder is 35 μm. The invention according to claim 3 provides the adhesive for A-type film bonding according to claim 1, in which the FEP resin resins 60 to 7 are used.
0% by weight, surfactant 0.3 to 0.5% by weight, water 2
9.5 to 39.5% by weight and has a viscosity of 4000 to 5
It is characterized in that it is 000 mPa · s.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An FE that is capable of filling irregularities on the film surface as an adhesive when heat-sealing A-type films to each other
P resin is required. Conventionally, an FEP resin film having a film thickness of 125 to 190 μm was used as the adhesive, and 260 to 400 g / m ² of FEP resin was present at the joint. The adhesive for A-type membrane bonding according to the present invention can be applied in a severe construction posture / construction environment on the membrane roof.
A FEP resin of the same amount as the conventional FEP resin film 125 to 190 μm (gel adhesive 370 to 670 g / m ² ) can be easily and surely applied / injected into the joint portion, and a steep slope with a roof slope of 60 to 70 ° It is formulated to have material properties that do not lean.

The present inventor newly prepared a gel adhesive for welding (FEP concentration: 60 to 70% by weight) in which FEP resin powder was added and dispersed in FEP resin dispersion, and used this as a welding and bonding material. The present invention has been completed by confirming through various experimental examinations that it is reasonable in terms of quality and construction by welding and bonding using a heat welding jig.

The FEP resin disversion is 0.2
3% by weight of FEP resin with μm diameter at a concentration of around 50% by weight
It is dispersed and stabilized by using front and rear surface active agents, and is used as a glass coating agent or a PTFE surface treatment agent. There is no document or application case report that uses this FEP resin dispersion as an adhesive for A-type film.

In the process of pursuing the cause of poor welding of the A-type film using the FEP resin film, the present inventor found that the water and water droplets existing between the A-type films, which are the adherends, were not directly welded in practice. It was confirmed experimentally that it could not be the cause. here,
At the FEP resin concentration level of about 50% by weight, it was difficult to secure a sufficient amount of FEP resin to fill the irregularities on the surface of the seed A film. This means that even when the required amount of disversion corresponding to the concentration is applied or injected, the outflow to the outside of the adherend film before heating the heating plate or the rapid evaporation of water or melt during the welding It means that the outflow to the outside of the adherend due to the flow cannot be sufficient. Also, in the welding joining using a hot plate,
Charring caused by carbonization of the surfactant occurs on the welded surface,
It has been a cause of deterioration of the quality of bonding.

In the process of making a prototype of FEP resin high concentration, about 65% by weight was obtained by adding FEP resin powder for paints having a center diameter of about 35 μm and water to FEP resin dispersion and stirring and mixing. It was confirmed that the gel adhesive for welding with a high concentration and a dispersant as low as about 0.4% by weight eliminates the above-mentioned problems. This gel adhesive for welding is applied to the A-type film, which is the adherend, in an amount of 200 to
When 400 g / m ^{2 is} applied and the welding and joining is carried out using a heat welding jig, it has the same welding and joining strength as the case of using the FEP resin film, and the joining end face also has good joining. Was verified through experimental examination and test construction.

Further, it has been found that a gel welding adhesive for welding can be used to effectively repair even a partial defective welding due to the adhesion of the FEP resin film. Improve productivity and ensure quality even when welding welding is performed by pressing the A-type film material and the filling film material that have introduced the tension that the center part is deformed by pressing the hot plate on the spot. Expected to contribute to many.

The content of the components of the adhesive for A-type film bonding according to the present invention is as shown in Table 1 below.

[Table 1] In addition, the viscosity and the total solid content (corresponding to the mass ratio of the FEP resin in the gel adhesive) of the A-type film bonding adhesive having the material characteristics are shown below.

The viscosity is 4000 to 5000 (mPa ·
s). The measurement test method conforms to JIS K 7117 (Viscosity test method S method for liquid resin using a rotational viscometer). Total solid content (nonvolatile content NV: Nonvolatile Conten
t) is 60.0 to 70.0 (% by weight).

The measurement test method is in accordance with JIS K 6833 (General Test Method for Adhesives 6.4 Nonvolatile Content). The viscosity of a general FEP resin dispersion is 10 to 20.
It was mPa · s, it was smooth, and it flowed out in the experiment simulating the roof slope, and could not be joined.

Further, in order to apply a predetermined amount of resin to the bonding surface with a low concentration dispersion, it is possible to apply it repeatedly, but if the applied surface is wet, it is not possible to repeat the application, and wait until the water content has splashed. And it became fine powder and scattered, and again it was not possible to repeat coating. The adhesive for A-type film bonding according to the present invention has a high resin content and a low surfactant content as compared with a general FEP resin dispersion.

The composition of the components is determined for the following reasons. The viscosity does not flow out during work on a steep slope with a roof slope of 60 to 70 °, and the viscosity is applicable as described below. The concentration of the surfactant should be such that the surfactant does not become thermally brown due to thermal denaturation when melt flow is integrated by heat and does not impair aesthetics and design.

In the coating operation, the total solid content should ensure a sufficient amount of resin to fill the irregularities of the A-type film. The adhesive for A-type film bonding according to the present invention is a fluororesin equivalent to the A-type film (base material) to be bonded. Therefore, when it is cooled after heating, the fluororesin of the A-type film is entangled by mutual entanglement of molecules. It does not break at the joint even if a peeling test is performed, and the glass fiber to base material coating (PT
The FE resin) has a destructive property of peeling.

This is because the A-type film itself is a composite material, and the adhesion strength between the glass fiber and the coating (PTFE resin) is inferior in strength to the heat-welded welded joint portion. By the way, when the peeling test was performed by hot-melt bonding with the A-type film used for the roof, the peel strength (in the initial state without deterioration) was 2 kgf even if the adhesion strength between the glass fiber and the coating fluororesin was weak.
/ Cm.

Next, an application example using the adhesive for A-type film bonding according to the present invention will be described with reference to the drawings. (Application Example 1) FIG. 1 shows a method of joining a roof member using a membrane roof 100 and a type A membrane. In this application example 1,
According to a conventional method, the A-type membrane 1 has a predetermined tension (for example, 300 k
gf / cm) and stretched over to form the tension-introducing membrane panel 2. At this time, the end portions of each tension-introducing membrane panel 2 are fastened and fixed by fastening the ends with bolts or nuts.

For example, a padding film material (flap film material) 4 for shunting rain is fixed to the joining portion 3 by welding by one-sided pressing on site. Also, the thin film material 4
Similarly, another space-filled film material 5 is fixed on the upper part of the same by welding bonding by one-sided pressing at the site. Furthermore, another padding film material 7 is similarly fixed to the panel joint portion 6 by welding by one-sided pressing at the site.

The thin film materials 4, 5, and 7 are all made of A type film. Here, the thin film material 4,
At the time of fusion bonding of 5 and 7, the adhesive 8 for A-type film bonding shown in Table 1 is applied to the bonding portion 3 at 200 to 400 g / m ² .
At this time, the A-type film bonding adhesive 8 has a viscosity of 4000-5.
Since it is 000 mPa · s, even if the tension-introducing membrane panel 2 has an inclination of 60 to 70 °, it does not flow out and remains on the applied joint portion 3.

Then, for example, as shown in FIG. 2, the heat-fixing jig 9 at 380 ° C. is pressed for 90 seconds from above the thin film materials 4, 5, and 7. Here, the heating dressing jig 9 has a weight of about 9
The size of the hot platen was 4 cm width × 30 cm length.
As a result, the A-type film bonding adhesive 8 applied to the bonding portion 3 spreads evenly on the bonding surface 3 by the pressure of the heat application jig 9, and the A-type film bonding adhesive 8 unnecessary for welding. Protrudes from the joint surface 3.

Thus, the padding member 4 placed on the joining portion 3 is joined to the joining portion 3 without any gap, and is integrated with the coating fluororesin of the joining portion 3. Of course, another padded film material 5 placed on the padded film material 4,
The other padding film material 7 placed on the panel joint portion 6 is also joined in the same manner. Therefore, according to the present embodiment, it is not necessary to manage the film insertion position when using the conventional FEP resin film, and stable quality can be obtained.

(Application Example 2) FIG. 3 shows a method for joining a roof member using a membrane roof 200 and a type A membrane. This application example 2
Is the same as in the above embodiment, by applying or injecting the adhesive for A-type film bonding to the unbonded portion, peeling, curling, or other defective portion 11 that has occurred in a portion of the space-filling film material 10 that has already been bonded. An example in which partial bonding is performed by pressing a heating bonding jig at 380 ° C. for 90 seconds from the top of the thinned film material 10 is shown.

According to this application example 2, even for a partially generated defective welding of a small area, an appropriate amount of the adhesive for bonding the A-type membrane can be injected into the gap portion with a syringe or the like, and the welding can be performed similarly. It is possible to perform stable welding without cutting the FEP resin film into small pieces and applying heat to a sound portion up to a size where the FEP resin film can be inserted and peeling the FEP resin film into a small size, unlike the conventional case.

(Application Example 3) FIG. 4 shows a method for joining a roof member using a membrane roof 300 and a type A membrane. Application example 3
Applies or injects the A-type membrane bonding adhesive to the difficult-to-join portion 13 of the membrane tension introducing panel 12 or the step portion 14 of the membrane tension introducing panel 12, and fills the thin film material 10 in the same manner as in the above embodiment. An example in which a heating jig at 380 ° C. is pressed from above for 90 seconds to perform partial joining is shown.

Also in the third application example, the same operational effect as the second application example shown in FIG. 3 can be obtained. (Application Example 4) FIG. 5 shows a method for joining roof members using a membrane roof 400 and a type A membrane. In the application example 4, the tearing, tearing, and puncturing of the membrane tension introducing panel 15 and the rubbing and abrasion of the stuffing film material 17 such as puncture, and the like, such as abrasion, are used for bonding the A-type film. Apply the agent and then A
After the repair members 19 and 20 made of a seed film are superposed on each other, a heating jig at 380 ° C. is pressed for 90 seconds from above the repair members 19 and 20 in the same manner as in the above-described embodiment to perform partial bonding. An example is shown below.

The repair members 19 and 20 have shapes corresponding to the corresponding defective portions 16 and 18. Also in the application example 4, the same operational effect as that of the application example 1 shown in FIG. 1 can be achieved.

[0030]

EFFECTS OF THE INVENTION Since the adhesive for A-type film bonding according to the present invention is made of a gel-like substance, it can be easily and uniformly introduced between the films to be bonded, and there is no welding defect. There is an advantage that it can be done and it can greatly contribute to the improvement of workability.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an application example 1 of the present invention.

FIG. 2 is an explanatory view showing a situation in which the welding and joining in FIG. 1 is performed.

FIG. 3 is an explanatory diagram showing a second application example of the present invention.

FIG. 4 is an explanatory diagram showing an application example 3 of the present invention.

FIG. 5 is an explanatory diagram showing an application example 4 of the present invention.

[Explanation of symbols]

1 Type A membrane 2,12,15 Tension introduction membrane panel 3 joints 4,5,7,10 Padding film material (flap film material) 6 panel joint section 8 A-type membrane bonding adhesive 9 Heat fixing jig 11 Defective part 13 Difficult to join 14 Step 16 Defects such as tears, tears, and holes 17 Padding film material 18 Defects such as rubbing and abrasion 19,20 Repair parts

Front Page Continuation (72) Inventor Soichi Kitani 8-21-1, Ginza, Chuo-ku, Tokyo Stock company Takenaka Corporation Tokyo Main Store (72) Inventor Yoshio Tanno 8-21-1, Ginza, Chuo-ku, Tokyo Shares Takenaka Corporation Tokyo Main Store (72) Inventor Yuichi Kozuka 8-21-1, Ginza, Chuo-ku, Tokyo Stock Company Takenaka Corporation Tokyo Main Store (72) Inventor Eiji Nishimura 3 Kokubuncho, Aoba-ku, Sendai City, Miyagi Prefecture No. 4-33 In the Tohoku branch of Takenaka Corporation (56) References JP-A-61-192758 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09J 127/18-127 / 20

Claims (3)

(57) [Claims] 1. An adhesive for bonding a type A film, which comprises a gel-like substance in which FEP resin powder is added and dispersed in FEP resin (tetrafluoroethylene / propylene hexafluoride copolymer resin). 2. The adhesive for A-type film bonding according to claim 1, wherein the FEP resin powder has a center diameter of 35 μm. 3. The adhesive for bonding a type A film according to claim 1, wherein 60 to 70% by weight of FEP resin resin, 0.3 to 0.5% by weight of surfactant, and 29.5 to 39.% of water. 5% by weight
And a viscosity of 4000 to 5000 mPa · s.