JPS5884874A - Hot-melt adhesive for polytetrafluoroethylene molded product - Google Patents

Abstract

PURPOSE:To obtain titled adhesive of high bonding potential, capable of avoiding fine crack, welding uneveness, etc., comprising a multicomponent copolymer of tetrafluoroethylene, hexafluoropropyrene and a perfluoro (alkylvinyl ether) in a specific ratio. CONSTITUTION:The objective adhesive comprising a multicomponent copolymer of (A) 91-98.5wt% of tetrafluoroethylene, (B) 1-6wt% of hexafluoroethylene, and (C) 0.5-3wt% of a perfluoro[alkyl (pref. propyl) vinyl ether]. For the application of the above adhesive, it is preferable to use a hot-air welding or hot- pressing system at 350-550 deg.C. EFFECT:Especially effective in hot-air welding.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot melt retractable agent for polytetrafluoroethylene molded articles.
) has excellent heat resistance, excellent chemical resistance, and electrical properties, and has unique properties such as high heat resistance, non-viscous properties, and low bank static properties. Because there is a chemistry machine, 1. PTFI is widely used in decorative cabinets, furniture, etc. However, due to its own low surface tension and cylindrical bath melting properties, it is difficult to bond with PTFI. 7g4 This is a national crisis, and the fact is that its use is limited to towns and cities.0 Therefore, an intermittent solution to this problem will only increase the differences in PTFE. Extremely lazy! I have iIE.

Reflecting these circumstances, the following materials that can be used for the main pillar and the contact layer of PTFI are (1) ethylene-tetrafluoroethylene copolymer (hereinafter sometimes referred to as r ETFF:, J), ( 2) Tetrafluoroethylene-
Hexafluoropropylene copolymer (hereinafter referred to as [FE
(sometimes referred to as PJ) and (3) tetrafluoroethylene-perfluoro(alkyl vinyl ether) co3
k coalescence (b waste, sometimes referred to as rPEAJ)
Copolymers of tetrafluoroethylene with low surface tension and low bath-viscosity such as fluorine-11 are known, but those in (1) above are known for their fluorination. Due to the relatively low proportion of vine #1 used as an adhesive, it does not have any adhesive strength, and the adhesive in (2) above is also inferior to (1). No, it doesn't have enough staying power. In fact, the above (3) is similar to the above (7) (1) (
Although it shows considerable adhesive strength compared to 2), for example, P
When the TFE molded body is exposed to heat, an undesirable dust phenomenon such as #tt] was observed on the surface of the PTFE molded body at the fFt joint end, and in addition, there were irregularities in bath welding and pinholes. Several problems arising from the one-separation nature of bath contact remain unsolved.

On the other hand, due to its excellent properties, PTFE is used as one of the materials that can be colored the most at high temperatures or in the presence of fake products.
If this is applied to equipment with PTFE lining, for example, even if the above-mentioned cracks, uneven bath welding, or pinholes occur in a small part of the shaking part, it will lead to serious accidents. There is a possibility that the present inventor 2 has solved the problems such as the lack of contact force of the PTFIi and the softening agent in the bonding of PTFIi, which has been carried out so far, and the unevenness and pinholes in the following 1L bath as described above. With the aim of solving Y0, we made a complicated proposal on seedling pretreatment agents and contact methods (% face appendix No. 56-49923), but as a result of extensive research and consideration, we have developed a specific phase formation method. Tetrafluoroethylene (hereinafter sometimes abbreviated as TFE), hexafluoropropylene (hereinafter sometimes abbreviated as RFP), and perfluoro(alkyl vinyl ether) (hereinafter referred to as 11?, abbreviated as PFVE) It has been found that the above-mentioned problems can be partially solved by employing a multicomponent coelectric combination with The present invention was completed based on this knowledge. That is, the hot melt adhesive for polytetrafluoroethylene molded articles of the present invention contains 91 to 98.5ii% TFE, HFPI to 6 carbonate @
% and PFVE '0. TFE as fluororesin
-HFP-PFVE multi-component copolymer itself is, for example,
5-45084 revolution, %lii? J 53-2938
As is known from Japanese Patent Application No. 9, etc., the hot melt adhesive according to the present invention has a co-enrichment composition within a specific range as described above among such copolymers, and such copolymers contain PTFE and PTFE. It has a high adhesive strength, there is no risk of welding unevenness, and it has excellent hot air weldability.

T i' E -I (EP -PFVE) according to the present invention
In the combination, the content of RFP is set to 61 from the sound axis, the content of PFVE is set to 3% from the lid, and the content of TFI is set to 61 from the sound axis.
The copolymer with a content of 91fii1% ta<t,
When performing thermal Kg shaking, there are undesirable antigens such as the appearance of the material being too thin, the weldability being rapid (difficult to perform the welding operation), and the inability to obtain sufficient crimp strength. Remove the content of HFP from l Shodenjima and PF'
A composite with a VE content lower than 0.51% and a TFI content lower than 98.5% is PTF.
There appears to be an undesirable situation in which she and E are separated from each other in their bathing suits.

The present invention hot melt & softening (with an addition rate of 6%)
In the TFIE-HFJP-PFVE copolymer), the alkyl of PFVE is particularly an alkyl group such as methyl, ethyl, propyl, or butyl, and among them, a propyl group is preferred.

The shape of this adhesive is not particularly limited, and it may be of any shape as long as it is used as a normal hot melt adhesive. Therefore, specifically, it can be used as an adhesive in the form of a stick, IJ/n, film, sheet, or tree depending on the situation. ! PTF'h with 1 enemy: Molded body clothing [11! After the cloth is produced, a step may be taken in which it is dried. The tangent curve is not particularly limited, for example, hot air f
Suitable methods include the G& method and the heat-pressing method. The adhesion temperature is preferably in the range of 350 to 500° OQ).

The objects to which the adhesive of the present invention can be applied include PTFW molded objects, PTFE molded objects, and substrates that can withstand temperatures such as NTJ (e.g., glass cloth, asbestos). A heat-resistant organic fiber fabric made of fibers such as polyimide and aromatic polyamide;
The contact layer with iron, metal materials such as Chirminiram) is cited6.
As described above, the hot melt adhesive having the composition of the present invention can be used as an image layer between a P'l'FE molded body and a PTF'E molded body, or as an image layer between a PTFE molded body and other heat-resistant The hot melt of the present invention is used for adhesion with a base material, and is particularly useful as a bath bonding method used in hot air bathing between a PTFI molded body and a PTF'E molded body. By using an adhesive, welding is strong and strong, there are no pinholes or irregularities in the bath process, and there is no risk of micro-cracks. The fact that #&) has become possible with PTFI makes it easier to line large containers with PTFI, and to easily construct and manufacture relatively small and complexly shaped physical and chemical equipment. Okawakami is extremely advantageous in that it has made it possible to create products with excellent quality.

Next, examples will be shown.

Laughter Example 1: Width: 100 mm, Kishi: 2 PTFE values were used, and these standards [IIJFviJ Zhi were hot-air bathed. In addition, here, TFE-HEP-perfluoro(propyl vinyl ether) resonant composite (resonance composite composition is 9% in charge capacity) is used as a bath decoration.
5/3.5/1.5 fc) using a direct 3m+ round bar, - blind spot 12000) single side butt hot air bath welding by blowing air at a temperature of 460°C at a flow rate of t12t/min. The contact speed was 70/min.

As a result, the tensile strength of PTFE resin was measured to be 125~/d, and no occurrence of 1utiua cracking was observed in PTF'1.

Example 2 Between the surface of a square PTFE plate with a width of 100 mm, a length of 100 mm, and a thickness of 2 m + 11 mm and a glass cloth of the same size, a thickness of approximately 0.5 mm (7) TFE-HF was placed.
A film of P-A-fluoro(furobyl vinyl ether) co-coallocated (co-polymerization ratio: 11, 95/4/1) was placed at a pressure of 511y/i, a pressure holding time of 1 minute, and a temperature of 3.
Heat pressure 5 at 80℃! As a result, the degree of stripping at the junction of the obtained polar RjI value is 3
．． It was 7 K4/cm.

Claims (1)

[Claims] 1, Tetrafluoroethylene 91-98.51 Bji axis, hexafluoropropylene 1-6 kii V@ and perfluoro(alkyl vinyl ether) 0.5-3
A hot-melt adhesive system for polytetrafluoroethylene molded articles, which is based on a multicomponent copolymer having a composition of 11%.