JPS5928356B2 - Water-dispersible hot melt adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-dispersible hot melt adhesive composition comprising a water-soluble polymer and an insoluble polymer, having a sharp cloud point, and being dispersible in water. It is something.

Conventionally, ethylene-
Vinyl acetate copolymer resin, polyamide resin.

A base resin made of saturated polyester resin, a tackifying resin made of rosin and its derivatives or petroleum resin,
Compositions consisting of waxes, plasticizers, fillers, and antioxidants are common. These hot melt adhesives are made of 100% solvent-free resin and have the characteristic of completing bonding in a very short time, and have shown remarkable development in recent years for applications such as automatic packaging, bookbinding, woodworking, plywood, and assembly. ing.

However, due to social problems such as pollution and resource conservation, there has recently been an increasing demand for hot melt adhesives that are water-soluble or water-dispersible.

The inventors made full use of various thermoplastic water-soluble polymer materials to achieve the performance of conventional hot melt adhesives.
Furthermore, we have discovered the possibility of producing a heat-stable water-dispersible hot-melt adhesive that can be used with existing hot-melt applicators.

Based on this knowledge, we have invented a hot melt adhesive that has good water dispersibility by imparting a sharp cloud point to the adhesive composition. This invention uses 1 to 80% by weight of polyoxyethylene having an average molecular weight of 1,000 to 1,000,000.
and polyoxyethylene nonionic surfactant 5 to 90
% by weight and 5 to 80% by weight of a tackifying resin.

Polyoxyethylene in this invention is a polymer obtained by polymerizing oxyethylene with an alkaline catalyst under heating, and is a liquid with an average molecular weight of 200 to 400, a semisolid of about 600, and a polymer of 1,000 to 20,000. Has a waxy body. In addition, especially polymerized with activated strontium carbonate or calcium carbonate catalyst,
There are also macromolecules of 0 to 1,000,000 or more. However, this invention has high water absorption or smoke generation when heated. Low-molecular substances with an average molecular weight of less than 1,000 are excluded for reasons such as odor-emitting properties, and polymers with an average molecular weight of 1,000,000 or more are also excluded because of their high melt viscosity.

The polyoxyethylene nonionic surfactant used in this invention is obtained by ring-opening polymerization of oxyethylene with various alcohols and phenols in the presence of a catalyst, and is polyoxyethylene lauryl ether. Polyoxyethylene cetyl ether. Polyoxyethylene stearyl ether. Polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether. Polyoxyethylene alkyl phenol ethers such as polyoxyethylene nonyl phenol ether, polyoxyethylene sorbitan monolaurate. Polyoxyethylene sorbitan monostearate. Polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monooleate and polyoxyethylene monolaurate. Polyoxyethylene monostearate. Polyoxyethylene distearate. Includes polyoxyethylene acyl esters such as polyoxyethylene monooleate. The tackifying resin used in this invention is composed of the following polymer.

(j) Derivatives of rosin, namely gum rosin. Wood rosin. Tall oil rosin. Hydrogenated rosin. Disproportionated leaf gin. Polymerized rosin. Rosin glycerin ester. Contains hydrogenated rosin pentaerythritol ester.

(11) α- and β-pinene type polyterpene resins obtained by cationic polymerization of α- and β-pinene.

011) A polyterpene phenol resin obtained mainly by copolymerizing α-pinene with phenol in the presence of BF3.

(JV) An aliphatic system obtained mainly by cationic polymerization of reactive components of naphtha cracked residue. Alicyclic hexagrams and aromatic hydrocarbon petroleum resins.

(v) α-methylstyrene-vinyltoluene copolymer styrene-acrylonitrile-indene terpolymer. Styrenic hydrocarbon resins such as oligostyrene.

Among these tackifying resins, rosin and its derivatives or styrene hydrocarbon resins in particular play a very important role in the water dispersibility of the hot melt adhesive, which is a feature of the present invention. .

That is, these tackifying resins impart a very sharp cloud point to a mixture system of polyoxyethylene and a polyoxyethylene nonionic surfactant.

More specifically, these adhesive compositions become microscopically incompatible at room temperature below the clouding point, and are a mixture of polyoxyethylene, a water-soluble material, and a polyoxyethylene nonionic surfactant. On the other hand, fine particles of the tackifying resin, which is a water-insoluble material, are uniformly dispersed. From this phenomenon, it can be easily inferred that even if a large amount of water-insoluble tackifying resin, which is an essential composition for hot melt adhesives, is used in the formulation, water dispersibility is not impaired. Furthermore, by setting the cloud point below the operating temperature, that is, the melt application temperature with an applicator, it was possible to prevent phase separation caused by incompatibility when the hot melt adhesive was heated for a long time.

In this way, by setting the cloud point above room temperature and below the usage temperature, we can produce hot melt adhesives that have good water dispersibility and heat stability that can be used with existing applicators. became possible. The above-mentioned rosin and its derivatives, or tackifier resins other than styrene hydrocarbon resins are used to finely adjust the cloud point, which is an important element for the present invention.

This invention will be explained in more detail below by listing embodiments of the invention.

In a 100 ml beaker, add polyoxyethylene nonylphenol ether. α-methylstyrene-vinyltoluene copolymer} and polyterpene phenol resin at 180%
After heating to °C and stirring until a homogeneous mixture is obtained,
Polyoxyethylene was gradually added at a heating temperature of 140° C. and stirred until a completely homogeneous mixture was obtained.

The hot melt adhesive thus obtained has the properties shown in Table 1 and is suitable for bonding adherends with low paper surface strength, such as the tail seal of toilet paper, for example.

In the hot melt adhesive prepared in the same manner as in Example 1 with this composition, liquid polyoxyethylene nonyl phenol ether (HLBlO.5) exhibits performance as a plasticizer, and is good in the temperature range from 0°C to 50°C. This is a water-dispersible pressure-sensitive hot melt adhesive having a high tack, the properties of which are listed in Table 1 together with the properties of Example 1.

The adhesive composition prepared in the same manner as in Example 1 with this composition is a water-dispersible hot melt adhesive having good adhesion to various porous or non-porous materials, and its properties are shown in Table 1. are shown along with the characteristics of Examples 1 and 2.

Claims (1)

[Scope of Claims] 1. A water-dispersible hot water dispersible product comprising 1 to 80% by weight of polyoxyethylene, 5 to 90% by weight of a polyoxyethylene nonionic surfactant, and 5 to 80% by weight of a tackifying resin. Melt adhesive composition. 2 The average molecular weight of polyoxyethylene is 1,000 to 1
,000,000. The water-dispersible hot melt adhesive composition according to claim 1, wherein 3. The polyoxyethylene nonionic surfactant is one or more selected from polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene sorbitan fatty acid ester, and polyoxyethylene acyl ester. A water-dispersible hot melt adhesive composition according to claim 1. 4. The tackifying resin is selected from abietic acid type rosin and its derivatives, polyterpene resin, polyterpene phenol resin, hydrocarbon petroleum resin obtained by polymerizing naphtha decomposition residue, and low molecular weight styrenic hydrocarbon resin.
The water-dispersible hot-melt adhesive composition according to claim 1, which is one or more types of adhesive compositions.