JPS5855997B2 - Paste hot melt adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel pasty water-insolubilized true melt adhesive.

Generally, hot melt adhesives are used in film and powder forms, but each type has its own problems in handling.

That is, in the case of a film type, the film must be cut according to the shape of the object, which is quite complicated when used for sewing clothes.

In addition, in the case of a powder type, the particle size of the powder must be changed depending on the type of adherend, and there are also disadvantages such as deterioration of the working environment due to scattering and movement of the powder, irregularity of the adhesive area, and difficulty in adjusting the amount of adhesive applied. There is.

Therefore, the present researchers realized that all of the above-mentioned drawbacks could be solved by pasty hot melt adhesives, and as a result of various studies on paste hot melt adhesives, they found that they could be divided into fine pieces such as powder or granules. hot melt adhesive (a)
, a water-soluble polymer compound (b), an insolubilizing agent (e) for the water-soluble polymer compound (b), and a liquid medium md that dissolves the water-soluble polymer compound but does not dissolve the hot melt adhesive)
The water-soluble polymer compound (b) is present in an amount of 1/10 or less by weight of the hot melt adhesive (a), and the liquid medium (d) is present in an amount of 1/10 or less by weight of the hot melt adhesive (a).
The amount is sufficient to wet the entire surface of the powder, and the hot melt adhesive part a), the water-soluble polymer compound (b),
It is characterized in that the homogeneous mixed phase of the insolubilizing agent (c) and the liquid medium (d) of the water-soluble polymer compound b) and the liquid phase not containing the hot melt adhesive (a) are present in an amount that does not cause phase separation. The inventors have discovered that a paste-like hot melt adhesive does not have the above-mentioned drawbacks and has an adhesive strength that is completely comparable to that of a hot melt adhesive obtained from powder alone, and has thus arrived at the present invention.

Examples of the hot melt adhesive (a) in the present invention include nylon copolymer, ethylene-vinyl acetate copolymer, etc., and examples of the water-soluble polymer compound (b) include polyvinyl alcohol, sodium polyacrylate, Examples include methyl cellulose and hydroxypropyl methyl cellulose, and although not particularly limited, those that decompose and discolor near the melting point of each hot melt adhesive resin are not preferred.

The finely divided hot melt adhesive (a) is not particularly limited, but it is preferable to use one with an average particle size of 0.1 to 250 microns.

The water-soluble polymer compound acts as a dispersant for the hot melt adhesive (a) when obtaining the pasty hot melt adhesive of the present invention.

In order to eliminate the possibility of the water-soluble polymer compound (b) leaching out when the adhesive surface comes into contact with water, contaminating the adherend or having an adverse effect on the adhesive strength, it is necessary to When the melt adhesive is heated to evaporate the liquid medium d), it must become insoluble in water.

The insolubilizing agent (c) of the water-soluble polymer compound (b) functions to cause such a water insolubilization phenomenon, and typical examples of the insolubilizing agent (e) include glycolic acid, lactic acid, etc. Monobasic acids; dibasic acids such as oxalic acid, tartaric acid, maleic acid, intaconic acid, malonic acid, succinic acid, geltaric acid, azelaic acid, sebacic acid; Examples include organic acids and inorganic acids such as polybasic acids such as acids, among which it is particularly preferable to use dibasic acids such as oxalic acid and tartaric acid, or the above polybasic acids.

As the liquid medium d) that dissolves the water-soluble polymer compound but does not dissolve the hot melt adhesive, water is the most convenient to handle, and drying can be accelerated by using a mixture of water as the main component and an organic solvent. Alternatively, it is also possible to slightly swell the hot melt adhesive to improve its adhesion to the adherend.

The amount of liquid medium (d) is adjusted depending on the desired viscosity of the paste.

The pasty hot melt adhesive of the present invention having the above-mentioned structure is not limited to the adherend, but can be applied to cloth, metal,
Applicable to a wide range of adherends such as resin.

The pasty true melt adhesive obtained according to the present invention is of a paste type that is easy to handle and is insoluble in water, which form an important feature of the present invention.

The present invention will be explained in detail below with reference to Examples.

Example 1 Nylon copolymer hot melt adhesive (Diamide
2302, manufactured by Daicel) 100 g, sodium polyacrylate (Aronbis M1 manufactured by Nippon Pure Chemical Industries) 0.2f, and oxalic acid 0.05'? were mixed and dispersed in water 1201 to prepare a paste hot melt adhesive.

When this was applied to various types of fabrics, the amount of application and the shape to be applied were freely controlled, and the handling was very easy.

It was also found that the adhesive strength was no different from the conventional powder method and film method.

On the other hand, it has become clear that the adhesive strength of fabrics bonded with this pasty true melt adhesive does not deteriorate at all even after washing, dry cleaning, and laundry, but rather improves.

Table 1 shows the results. Example 2 Approximately 50μ of ethylene-vinyl acetate copolymer hot melt adhesive (ELPAX) powder 100P, sodium polyacrylate 0.21, and oxalic acid 0.05'? were mixed and dispersed in 130P of water to prepare a paste hot melt adhesive.

This pasty hot melt adhesive is very easy to handle, and the adhesive strength between cotton is approximately 1650 y'.
/15 mm (adhesion conditions: 150°C for 3 seconds), and the adhesive strength did not decrease at all even when it was made into a paste.

Example 3 Approximately 100 micron nylon copolymer hot melt adhesive (Diamide X-1874, manufactured by Daicel) powder 100
A paste-like hot melt adhesive was prepared by mixing P, methyl cellulose, 1 g of hydroxypropyl methyl cellulose (Metrose, manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.04 P of tartaric acid, and dispersing these powders in water.

This paste-like hot melt adhesive was applied between aluminum plates with a thickness of 0.5 mm, and the adhesive was applied at 180°C at 10 kg/cm.
Bonding was performed under bonding conditions of 4.60 seconds.

The adhesive strength was 8.0 kg and 725 mm, which was no different from the adhesive strength obtained by the film method.

Claims (1)

[Scope of Claims] 1. A true melt adhesive (a) finely divided into powder, granules, etc., a water-soluble polymer compound (b), and an insolubilizer for the water-soluble polymer compound (b) (c) and a liquid medium (d) that dissolves the water-soluble polymer compound but does not dissolve the hot melt adhesive, and the water-soluble polymer compound (b) is in an amount of 1710% or less by weight of the hot melt adhesive Ra). the liquid medium (d) is in an amount sufficient to wet the entire surface of the powder of the hot melt adhesive part 1ja), and the liquid medium (d) is in an amount sufficient to wet the entire surface of the powder of the hot melt adhesive part 1ja), and characterized in that the homogeneous mixed phase of the insolubilizing agent (c) and the liquid medium (d) of the hot melt adhesive (b) and the liquid phase not containing the hot melt adhesive (a) are present in an amount that does not cause phase separation. Paste-like hot melt [=adhesive.