JPS62212482A - Thermal tack composition - Google Patents

Abstract

PURPOSE:To obtain a thermal tack composition which has improved persistence of tackiness and adhesiveness after thermal activation, by mixing a polymer and a solid plasticizer comprising a specified aromatic carboxylic acid ester having phenolic hydroxyl groups. CONSTITUTION:A thermal tack composition which essentially consists of a polymer (a) and a solid plasticizer (b) comprising a compound of the formula, and preferably contains a tackifier (c). In the formula phi is an aromatic hydrocarbon ring which may have substituents; R is alkyl, cycloalkyl, alkenyl or aralkyl (the aromatic ring may have substituents). Examples of the solid plasticizer include phenyl salicylate, methyl p-hydroxybenzoate, and methyl 2-hydroxy-3- naphthoate. The aforementioned solid plasticizers have each a specific melting point. When heated to a high temperature above its melting point, it melts to form a liquid and acts as an effective plasticizer for an adjacent polymer, giving tackiness to the thermal tack composition.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is non-tacky at room temperature, but becomes activated by heating to reveal glaze layer properties (tack), and even after being separated from the heat source, the glaze often remains sticky. The present invention relates to a thermal tack composition that can adhere to or adhere to various objects for a long period of time.

That is, by applying the above-mentioned composition onto a substrate (base sheet) such as paper or film, a heat-sensitive adhesive sheet such as a heat-sensitive label or a heat-sensitive seal can be obtained. The pressure-sensitive adhesive sheet is sticky at room temperature, so li#! While a protective sheet called a paper pattern is essential, a heat-sensitive adhesive sheet does not require one, and has therefore attracted attention in recent years as a resource-saving and economically advantageous adhesive sheet.

(Bl Conventional technology Typical examples of the types and quantitative ratios of various chemical materials used in thermal tack compositions can be found, for example, in the 12th edition of "Adhesive Handbook" published by Kobunshi Publishing Association (published in 1982). Basically, polyvinyl acetate, polybutyl methacrylate, vinyl chloride-vinylidene chloride copolymer, synthetic comb, vinyl acetate-2-ethylhexyl allylate copolymer, vinyl acetate-ethylene copolymer, vinylpyrrolidone- Polymers such as styrene copolymer, styrene-butadiene copolymer, vinylpyrrolidone-ethyl acrylate copolymer, heptal-acid dicyclohexyl, diphenyl phthalate, dihexyl phthalate, dihydroabethyl phthalate, dimethyl isophthalate, benzoic acid Sucrose, ethylene glycol dibenzoate, trimethylolethane tribenzoate, tribenzo': 4i
Solid plasticizers such as acid glycerides, pentaerythritol tetrabenzoate, sucrose helacetate, tricyclohexyl citrate, N-cyclohexyl-p-)luenesulfonamide, tehydroabiethylamine carbonate, methoxyethyl stearate-urea complex, etc. Togarashi, preferably further contains indene resin, ethyl cellulose, petroleum resin (hydrocarbon resin), terpene resin, rosin derivative (J!
It contains adhesion agents such as resin acid dimer, etc.).

According to these descriptions and other known documents, a thermal tack composition can be obtained on a trial basis, but the present inventor has found that it is difficult to produce one that can be put to practical use.

In the above chemical materials, the polymer is the source of adhesion and without it, cohesive force during adhesion cannot be obtained.The solid plasticizer does not impart properties to the polymer at room temperature, so the composition Although it is non-tacky at room temperature, upon heating, it first melts into a liquid state, wets or dissolves the polymer, softens it, and forms a barge glaze layer to develop tackiness. At this time, if a tackifier is also present, the tackiness will be more pronounced and the practical usefulness will be enhanced.

It is practically required that the composition activated by heating maintains its tackiness even after being removed from the heat source and returning to room temperature.

This is because if time is taken from heat activation to application of the adhesive sheet to the adherend, assembly work can be carried out continuously, which is very efficient.

0 Problems to be Solved by the Invention Among various adherend materials, materials with low polarity such as special plastic materials are considered to be mainly adhesive and resistant to adhesion for a certain period of time after application. If the adhesiveness is lost, the adhesive sheet may be prematurely peeled off from the adherend, which seriously impairs its practical value.

The inventor of the present invention has found from a stationary mold test that this adhesive persistence (duration time) largely depends on the type of the refusible agent, and that even the best of the conventionally known refusible agents does not reach a fully satisfactory level. I learned that there isn't one.

The present invention therefore seeks to solve the problem of the prior art, in particular that the duration of the adhesive properties of heat-sensitive adhesive compositions after heat activation is not long enough.

(2) Means for Solving the Problems In solving the above problems, the present inventors have made great progress by developing a new material and using it as a plasticizer.

The solid plasticizer newly proposed by the present invention for use in the thermal tack composition is an ester of an aromatic carboxylic acid having a phenolic hydroxyl group, and is represented by the following general formula.

However, in the formula, φ is an aromatic hydrocarbon bulk ring which may have a substituent t% 几 is a group consisting of alkyl, cycloalkyl, alkenyl, aralkyl (the aromatic ring may have a substituent) υ Each represents a selected group.

No literature has been found stating that these compounds are useful in thermal tack compositions.

Specific examples of solid plasticizers useful in the present invention are as follows.

phenyl salicylate methyl meta-hydroxybenzoate ethyl meta-hydroxybenzoate phenyl para-hydroxybenzoate methyl para-hydroxybenzoate ethyl para-hydroxybenzoic acid n-propyl para-hydroxybenzoic acid in-gropyl para-hydroxybenzoic acid n
-butyl para-hydroxybenzoic acid iso-butyl para-hydroxybenzoic acid secondary butyl para-hydroxybenzoic acid n-hebutyl para-hydroxybenzoic acid stearyl para-hydroxybenzoic acid cyclohexyl para-hydroxybenzoate allyl para-hydroxybenzoic acid benzyl para -Hydroxybenzoic acid β-phenylethyl para-hydroxybenzoic acid 4-chlorobenzyl para-hydroxybenzoic acid 4-methylbenzyl 1-hydroxy-2-naphthoic acid phenyl 2-hydroxy-3-naphthoic acid methyl 2-hydroxy-3- Ethyl naphthoate 2-hydroxy-3-phenyl naphthoate Dimethyl 4-hydroxyphthalate Diethyl 4-hydroxyphthalate Di-n-propyl 4-hydroxyphthalate Diisogropyl 4-hydroxyphthalate 4-Dibenzyl hydroxyphthalate 4-Hydroxyphthalate Dicyclohexyl 2-hydroxyisophthalate dimethyl 2-hydroxyisophthalate diethyl 2-hydroxyinphthal modified diphenyl 4-hydroxyinphthalate dimethyl 4-hydroxyisophthalate diethyl 5-hydroxyisophthalate diethyl hydroxyterephthalate.

The solid plasticizers used in the present invention are actually colorless solids that are crystalline at room temperature, each having its own melting point, and when heated to a high temperature higher than that melting point, it melts and becomes liquid. It acts as an effective plasticizer for coalescence and imparts tack to the thermal tack composition.

These compounds can be synthesized by adding an alcohol to the corresponding hydroxy-substituted aromatic carboxylic acid and carrying out an esterification reaction in the presence of an acid catalyst.

Further, these solid plasticizers may be used alone in the thermal tack composition, or a plurality of them may be used in combination. Of course, good results can also be obtained when used in combination with known solid plasticizers.

(g) Examples In this embodiment, all "sections" refer to "rim sections."

Example 1 Eleven types of solid plasticizers used in the present invention were taken and first ground in the following manner to prepare an aqueous suspension solution.

Solid plasticizer 50 parts Polyvinyl alcohol 3 parts Nonionic surfactant 3 parts Water was added to make the plasticizer concentration 25%, and the solid plasticizer was wet-pulverized using a ball mill to form fine particles.

Next, 5.0 parts of styrene-acrylic acid ester copolymer (
Solid content) Vinyl acetate-ethylene copolymer 5.0 parts (solid content) Rosin ester 2.5 parts (solid content) Add water to the above solid plasticizer fine particle suspension 16 parts (solid content) to determine the total solid concentration. 5 (l) of aqueous coating liquid.

When these coating solutions were applied to one side of art paper having a basis weight of 80 at a dry coating weight of 20 f/paper and dried at room temperature, a non-tacky coated paper was obtained.

These coated papers were activated by heating for 30 seconds in a constant temperature chamber at -150°C, and the degree of tack immediately thereafter was measured according to the inclined ball tack measurement method (temperature 2
0℃, inclination angle 30 degrees).

The results are shown in Table 1.

A composition containing a hydroxy-substituted aromatic carboxylic acid ester compound exhibits remarkable tackiness when heated.

(Margin below) Example 2 Varahi used in the present invention as a solid plasticizer.

Isobutyl droxybenzoate (m, p, 76°C) and known dicyclohexyl phthalate (m, p, for comparison).

65° C.) and pulverized in the same manner as in Example 1 to obtain fine particles of aqueous suspension suspension.

Next, water was added to 100 parts (solid content) of ethylene-vinyl acetate copolymer emulsion, 150 parts (solid content) of solid plasticizer suspension, and 50 parts (solid content) of polymerized rosin-polyhydric alcohol ester emulsion. In addition, an aqueous coating solution with a total solid content concentration of 5 Oqb was prepared.

Each coating liquid has a basis weight of 80 f/W? It was applied to one side of art paper and dried at 40°C. The amount of application after drying is 2 for both.
It is a blasphemy.

These pieces of paper were activated by heating at 120° C. for 20 seconds and left at room temperature.

When the adhesive surface was observed after one week, crystallization had clearly progressed in the comparison sample, and it did not feel sticky even when touched with fingers. , two sides.

In the sample according to the present invention, no crystallization was observed and the sample was strongly sticky.

In addition, we attached the sample immediately after activation under the above conditions to the copper of a voriglopyrene bottle, left it at room temperature for one week, and then tried peeling it off with our fingernails. -, but the comparative sample could be peeled off from the bottle.

That is, in the example according to the present invention, a clear improvement in adhesiveness was observed.

(G) Effects of the Invention As mentioned above, the thermal tack composition of the present invention using a hydroxyl-substituted aromatic carboxylic acid ester compound as a solid transport agent develops remarkable tackiness upon heating and adheres well. It exhibited the effect of being able to successfully adhere sheets, etc. to the body.

Proceedings No. 1n (spontaneous) July 25, 1985 1, Indication of the case 1988 Patent Application No. 56157 2, Title of the invention Thermal tack composition 3, Person making the amendment Relationship with the case Patent applicant Address Mitsubishi Paper Mills Co., Ltd. Patent Department 4 (600) 2111 4, 3-4-2 Marunouchi, Chiyoda-ku, Tokyo, Japan Column Paper 2, Claims Basically consisting of (a) a polymer and (b) a solid plasticizer,
Preferably (c) a thermal tack composition comprising a tackifying agent, wherein the solid plasticizer is a compound represented by the following general formula; In the formula, Φ represents an aromatic hydrocarbon ring which may have a substituent, and R represents alkyl, cycloalkyl, alkenyl,
each represents a group selected from the group consisting of aralkyl (the aromatic ring thereof may have a substituent) and phenyl).

Attachment

Claims (1)

[Claims] Basically consisting of (a) a polymer and (b) a solid plasticizer,
Preferably (c) a thermal tack composition comprising a tackifying agent, wherein the solid plasticizer is a compound represented by the following general formula, General formula: ▲ Mathematical formula, Chemical formula , tables, etc. ▼ {However, in the formula ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ represents an aromatic hydrocarbon ring that may have a substituent, R represents an alkyl,
Each represents a group selected from the group consisting of cycloalkyl, alkenyl, and aralkyl (the aromatic ring thereof may have a substituent).