JPH0786189B2 - Pressure sensitive adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a pressure-sensitive adhesive, more specifically an acrylic emulsion pressure-sensitive adhesive, which is applied to the outer surface of a glass, ceramic or plastic container. The present invention relates to a pressure-sensitive adhesive useful as a seal, label, etc. used for sealing various cases in the distribution industry.

(Prior Art) In recent years, acrylic pressure-sensitive adhesives have been widely used in place of conventional natural rubber-based and synthetic rubber-based pressure-sensitive adhesives because of their excellent adhesive properties and durability. Also, water-based pressure-sensitive adhesives have been researched and developed in consideration of resource saving, environmental hygiene, and product cost.

Natural rubber-based and synthetic rubber-based pressure-sensitive adhesives have poor durability at low temperature, lack of cohesive strength at high temperature, etc. Excellent shearing force.

For this reason, a pressure-sensitive adhesive is applied to a base material such as paper to resist the restoring force of the base material such as when used as a label, a seal or the like on a curved surface of a container or a bent portion, or for sealing various cases. Natural rubber-based and synthetic rubber-based pressure-sensitive adhesives are still predominant in applications requiring repulsion resistance.

Conventional acrylic pressure sensitive adhesives are not satisfactory when applied to applications where high shear forces are desired. Therefore, in order to further improve the shearing force of this type of pressure-sensitive adhesive, it has been attempted to add a cross-linking agent such as an aziridine compound, a melamine compound, an epoxy compound, a metal salt to an acrylic emulsion obtained by emulsion polymerization. Came. However, with such a means, only the cohesive force becomes large, and the adhesive force and the tackiness are reduced accordingly, so that the pressure sensitive adhesive having high adhesive force, high tackiness and high shearing force is eventually obtained. It was difficult to obtain an agent composition.

(Problems to be Solved by the Invention) The present invention provides a pressure-sensitive adhesive having both durability and high shearing force. Furthermore, the present invention provides a water-based pressure-sensitive adhesive having high adhesive strength and high tackiness.

[Structure of Invention]

(Means for Solving the Problems) In the present invention, (a) an alkyl acrylate in which an alkyl group has 4 to 12 carbon atoms 50 to 99.89% by weight (b) an α, β-unsaturated carboxylic acid 0.1 to 15 Wt% (c) dialkyldiallylammonium halide 0.01-
20% by weight (d) A pressure-sensitive adhesive characterized by being copolymerized with 0 to 49.89% by weight of a vinyl-based monomer other than the above.

The alkyl group used in the copolymer of the present invention has a carbon number of 4
Examples of the alkyl acrylate (a) of 12 to 12 include acrylates of linear or branched aliphatic alcohols such as butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate and 2-ethylhexyl acrylate. You can Particularly preferred is 2-ethylhexyl acrylate. In order to obtain basic physical properties as a pressure-sensitive adhesive, the amount of these alkyl acrylates used is preferably 50 to 99.9% by weight of the total copolymer.

Examples of the α, β-unsaturated carboxylic acid (b) of the present invention include acrylic acid, methacrylic acid, maleic anhydride, crotonic acid, itaconic acid and fumaric acid. α, β-
The unsaturated carboxylic acid (b) is 0.1 to 1 based on the copolymer.
By co-polymerizing 5% by weight with other necessary monomers, the adhesiveness and cohesive force of the pressure-sensitive adhesive can be balanced.

The dialkyldiallylammonium halide (c), which is one component of the copolymer of the pressure-sensitive adhesive of the present invention, is represented by the following general formula.

Is a lower alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, and X is a halogen atom such as chlorine and bromine.
These dialkyl diallyl ammonium halides can be obtained as an aqueous solution.

The dialkyldiallylammonium halide is preferably used in an amount of 0.01 to 20 parts by weight with respect to the copolymer, and when it is more than 20% by weight, aggregates are likely to occur during the production of the copolymer by the emulsion polymerization method, which is preferable. Without 0.01
If the amount is less than wt%, the cohesive force of the pressure-sensitive adhesive decreases and the effect of the present invention cannot be achieved. Also, the amount of dimethyl dialkhalide used varies depending on the application, and in applications where the adhesive strength is important, 0.1-5 wt% is preferable,
For applications called re-peeling, 2 to 15% by weight is preferable.

As the vinyl monomer (d) other than the above which can be used in the copolymer of the present invention, an alkyl acrylate having an alkyl group having 3 or less carbon atoms, for example, methyl acrylate,
Ethyl acrylate, propyl acrylate and the like, methacrylic acid ester having an alkyl group having 1 to 12 carbon atoms, for example, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and the like, vinyl acetate,
Examples include styrene, vinyltoluene, and acrylonitrile.

The copolymer of the present invention can be produced by general emulsion polymerization, but can also be produced by solution polymerization. In the case of production by emulsion polymerization, the monomers of the components (a) to (d) may be mixed as a mixture and emulsion-polymerized in an aqueous system in the presence of an emulsifier and a polymerization initiator.

(Example) Example 1 Pure water 65 parts Sodium diphosphate 0.6 part Dodecylbenzene sulfonate 1 part Polyoxyethylene octylphenol ether 1 part Weigh and heat to 80 ° C under stirring at 150 RPM Then, 2-Ethylhexyl acrylate 79 parts Vinyl acetate 15 parts Acrylic acid 5 parts Dimethyldiallylammonium chloride 1 part A mixture of 5% potassium persulfate aqueous solution 6 parts was added dropwise uniformly over 3 hours into the reaction system kept at 80 ° C. , Polymerized. After dropping all the monomers, the reaction was continued at 80 ° C. for 2 hours to complete the polymerization.

This composition was applied to crystal coated paper (Nippon Kakoh Paper Co., Ltd.)
Applied at 100 ℃ for 2 minutes (coating amount dry 30-40g / m
² ) Heat dried to obtain a sample piece.

Next, the above sample was pasted on a stainless steel plate, roll-pressed according to JIS method, 180 degree peel strength, ball tack and shear force were measured by a Shopper type peel tester, stuck to various containers with curved surfaces and marketed The cardboard case was sealed.

The results are shown in Table 1.

Example 2 70 parts of pure water 0.6 parts of sodium acetate Polyoxyethylene sorbitan monolaurate 1 part Polyoxyethylene nonylphenol ether 1 part Weigh and heat to 80 ° C. under stirring at 15 RPM. Then, a mixture of 2-ethylhexyl acrylate 58 parts butyl acrylate 27 parts vinyl acetate 10 parts acrylic acid 3 parts dibutyldiallylammonium chloride 2 parts and 10% ammonium persulfate aqueous solution 6 parts in a reaction system kept at 80 ° C. for 3 hours. It is dripped evenly over and polymerized. After all the monomers were dropped, the reaction was continued at 80 ° C. for 2 hours to complete the polymerization. This composition was used in Example 1.
A sample piece was prepared and tested in the same manner as above. The results are shown in Table 1.

Comparative Example 1 A composition was obtained in the same manner as in Example 1, except that dimethyldiallylammonium chloride was not added in Example 1, and a sample piece was prepared and evaluated. The measurement results are shown in Table 1.

Example 3 Pure water 68 parts Sodium diphosphate 0.6 parts Dodecylbenzene sulphonate 1 part Polyoxyethylene octylphenol ether 1 part Weigh and heat to 80 ° C. under stirring at 150 RPM then acrylic acid 2- A mixture of 80 parts of ethylhexyl, 5 parts of vinyl acetate, 5 parts of acrylic acid, and 10 parts of dimethyldiallylammonium chloride and 6 parts of a 5% potassium persulfate aqueous solution were uniformly added dropwise to the reaction system kept at 80 ° C. for 3 hours for polymerization. After all the monomers had been added dropwise, the reaction was continued at 80 ° C. for 2 hours to complete the polymerization.

This composition was applied to a high-quality paper (45 kg) and dried by heating at 100 ° C. for 2 minutes (coating amount dry 20 g / m ² ) to obtain a sample piece.

Next, the above-mentioned sample piece was stuck to a stainless steel plate, roll-bonded according to JIS method, 180 degree peeling height was measured by a Shopper type peeling tester, and contamination on various adherends was examined.
The results are shown in the table below.

Example 4 Pure water 70 parts Sodium acetate 0.6 parts Polyoxyethylene sorbitan monolaurate 1 part Polyoxyethylene nonylphenol ether 1 part Weigh and heat to 80 ° C. under stirring at 150 RPM. Then, a mixture of 2-ethylhexyl acrylate 65 parts butyl acrylate 17 parts vinyl acetate 10 parts acrylic acid 2 parts dibutyl diallyl emmonium chloride 5 parts and 10% ammonium persulfate aqueous solution 6 parts in a reaction system kept at 80 ° C. Polymerization is carried out by dropping evenly over 3 hours. After all the monomers were dropped, the reaction was continued at 80 ° C. for 2 hours to complete the polymerization.

The composition was operated in the same manner as in Example 3 to prepare a sample piece, and the adhesive strength and the stain resistance to various adherends were similarly examined.

Comparative Example 2 A sample piece was prepared and compared in the same manner as in Example 4, except that dibutyldiallylammonium chloride was not added in Example 4. The measurement results are shown in Table 2.

EFFECTS OF THE INVENTION The pressure-sensitive adhesive composition of the present invention has high adhesive strength, high tackiness, and high shearing force, and therefore metal, glass, pottery, PVC,
It can be applied by selecting the kind of adherend such as polyethylene. In particular, even if it is attached to a curved surface of the container, a bent part, a label for sealing the case, a part such as a seal where the restoring force of the base material works, the label and the seal partly peel off with time. There is no such thing.

In addition, the pressure-sensitive adhesive composition of the present invention can be designed in a wide range from removable pressure-sensitive adhesives to applications in which adhesive strength is important, depending on the amount of the dialkyldiallylammonium halide compounded.

Claims (1)

[Claims] 1. (a) Alkyl acid alkyl ester having an alkyl group having 4 to 12 carbon atoms 50 to 99.89% by weight (b) α, β-unsaturated carboxylic acid 0.1 to 15% by weight (c) Dialkyldiallylammonium Halide 0.01〜
20% by weight (d) A pressure-sensitive adhesive characterized by being copolymerized with 0 to 49.89% by weight of a vinyl-based monomer other than the above.