JPS6045672B2 - hot melt adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to hot melt adhesive compositions.

Many hot melt adhesives made from thermoplastic resins such as polyethylene, ethylene-vinyl acetate copolymers, ionomers, and nylon have been known.

However, polyethylene, ethylene vinyl acetate copolymer,
When ionomers and the like are used for adhering metals, etc., sufficient adhesion strength cannot be obtained, making it difficult to put them into practical use.

Although nylon has a certain degree of adhesive strength to metals, it is still not sufficient, so nylon is mixed with epoxy resin, or so-called nylon film is coated with epoxy resin on both sides of the nylon film.
Epoxy-based hot melt adhesives have been proposed; however, such adhesives require a considerable amount of time to complete curing and are expensive, so they are not suitable for general use. It's not appropriate. In addition, attempts have been made to improve adhesive strength by mixing nylon with ethylene-vinyl acetate copolymer ionomers, etc., but in all cases, satisfactory results in improving adhesive strength have not been obtained. However, it is desired to further improve the strength. In view of the current situation, the present invention has been made for the purpose of providing a hot melt adhesive composition that has excellent adhesive strength to metals, etc., is easy to use, and is inexpensive. A hot melt adhesive composition characterized in that 1 to 20 parts by volume of polytetrafluoroethylene is mixed with 100 parts by weight.

In the present invention, the nylon polymer is generally referred to as nylon, and is conventionally known to be used as a hot melt adhesive.

For example, it refers to nylon 12, nylon 11) nylon 6, nylon 66, nylon 610, and copolymers thereof. Further, in the present invention, the polytetrafluoroethylene to be mixed with the nylon polymer is preferably used in the form of fine particles, and the preferred particle size is 100 microns or less.

In order to produce the adhesive composition of the present invention, the nylon polymer and the polytetrafluoroethylene may be added and mixed to form a suitable shape, for example, powder or pellets of these polymers. Preferred methods include mixing the mixture and applying it to an extruder to form it into a film, line, or pellet, or kneading it using a roll, kneader, panball mixer, etc. and forming it into a sheet or the like. Regarding the amount of the nylon polymer and polytetrafluoroethylene used, the latter is 1 part by weight for every 10 parts by weight of the former.
It is necessary to use it in a range of 200 parts by weight.

The reason for this is that if the amount of polytetrafluoroethylene used is less than 1 part by weight, the effect of increasing the peel strength of the resulting adhesive composition will not be achieved, and if it exceeds 200 parts by weight, the nylon polymer will This is presumed to be due to exceeding the limit of miscibility, but it is also because the peel strength tends to decrease.

The adhesive composition of the present invention can be used for the same purposes as general hot-melt adhesives, but in particular metal materials such as iron, aluminum, copper, and brass, glass, ceramics, etc.
It exhibits excellent properties and is used to bond inorganic materials such as slate and concrete, fibrous materials such as cotton, silk, wool, Tetoron and nylon fibers, and paper products.

Note that additives such as colorants and fillers may be added to the adhesive composition of the present invention as necessary. The hot melt adhesive composition of the present invention has the above-mentioned structure, and is capable of exhibiting excellent adhesive strength.

Examples of the present invention will be described below.

Example 1 Copolymerized nylon (melting point 11rC1 melt index 3
5) and finely divided polytetrafluoroethylene (melting point 32
3°C, maximum particle size 24 microns) in the proportions shown in Table 1, and extruded to a thickness of 100 microns. A film adhesive was made by extruding it into a film.

Next, this adhesive was placed between two zinc-copper plates with a thickness of 0.6 that had been degreased with acetone, and the steel plates were bonded together at a temperature of 120°C and a pressure of 2k9k for 2 minutes. 20
3 under the conditions of 60% relative humidity at °C. I left it for days. The T-peel strength of the thus bonded zinc-copper plates was measured.

The measurement conditions were a peeling rate of 50 TUfL/min and a sample width of 25 mm.
The temperature was 20°C and the humidity was 60%. The measurement results of T peel strength are shown in Table 1. Comparative Example 1 An adhesive was prepared in the same manner as in Example 1 using only copolymerized nylon (same as in Example 1), and the T-peel strength was measured.

The results were as shown in Table 1.

Comparative Example 2 An adhesive was prepared in the same manner as in Example 1 by blending copolymerized nylon (same as in Example 1) and heavy calcium carbonate (particle size: 6.3 microns) in the proportions shown in Table 1. Then, the T peel strength was measured.

The results were as shown in Table 1. Example 2 Nylon 12 (melting point: 179 C) and polytetrafluoro I
Ethylene (same as in Example 1) was blended in the proportions shown in Table 1, and an adhesive was prepared in the same manner as in Example 1.

Next, a sample was prepared in the same manner as in Example 1, except that bonding was performed at a temperature of 240°C, a pressure of 2kgId, and 12 minutes.
T-peel strength was measured. The results were as shown in Table 1. Comparative Example 3 The same procedure as in Example 2 was carried out except that nylon 12 (same as in Example 2) was used alone as an adhesive.

The results were as shown in Table 1. Comparative Example 4 An adhesive was prepared in the same manner as in Example 2 except that nylon 12 (same as in Example 2) and heavy calcium carbonate (same as in Comparative Example 2) were used in the proportions shown in Table 1 to form an adhesive.

The results were as shown in Table 1. Examples 3 to 6, Comparative Examples 5 and 6 In the same manner as in Example 1, adhesives having the compositions shown in Table 2 were prepared, and the T-peel strength was measured. The results were as shown in Table 2. The copolymerized nylon and polytetrafluoroethylene were the same as in Example 1, the nylon 12 was the same as in Example 2, and the calcium carbonate was the same as in Comparative Example 2.

Examples 7 to 9 In the same manner as in Example 1, adhesives having the compositions shown in Table 3 were prepared, and the T-peel strength was measured.

The results were as shown in Table 3. The same copolymerized nylon and polytetrafluoroethylene as in Example 1 were used, and the same as in Example 2 was used as nylon 12.

Claims (1)

Claims: 1. A hot melt adhesive composition comprising 1 to 20 parts by weight of polytetrafluoroethylene mixed with 100 parts by weight of a nylon polymer. 2. The composition according to item 1, wherein the polytetrafluoroethylene is in the form of fine particles.