JPS6211786A - Production of pressure-sensitive adhesive tape or film - Google Patents

Abstract

PURPOSE:To obtain a solvent-free type pressure-sensitive adhesive tape, etc., containing a pressure-sensitive adhesive free from greasiness of film of coating, by blending a specific polyether with a pressure-sensitive adhesive resin under heating, adding a crosslinking agent to the blended and dissolved material, applying the material to a specific substrate under specific condition and crosslinking the material. CONSTITUTION:A polyether containing a hydrolyzable silicon group, comprising a main chain having a chemically bonded repeating unit shown by the formula -R-O-(R is bifunctional alkylene) and a pressure-sensitive adhesive resin (e.g., rosin resin, modified phenolic resin, etc.) are put in a dissolving tank. The pressure-sensitive adhesive resin is dissolved in the dissolving tank under heating and blended with the polyether. The blended dissolved material is blended with a crosslinking promotor (preferably organotin compound, etc.,), applied to a substrate in humid steam at 40-160 deg.C and crosslinked, to give the aimed tape or film.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing an adhesive tape or film coated with a substantially solvent-free adhesive.

[Conventional technology]

Adhesive to polyethers containing at least one hydrolyzable silicon group and whose main chain has chemically bonded repeating units essentially of the formula -R-0- (R is a divalent alkylene group) A solvent-free adhesive containing a resin or the like is described in, for example, Japanese Patent Application Laid-open No. 71377/1983. The manufacturing method involves adding a predetermined amount of adhesive resin, etc. to the polyether, melting it using a mixing machine such as a Banbury mixer, kneader, or roll, and finally adding a curing catalyst to uniformly dissolve the polyether. Mix. It is described that the liquid composition is then applied onto a support to a certain thickness using a roll coater and cured at room temperature to 150°C.

[Problem that the invention seeks to solve]

By the way, adhesive resin is usually in the form of flakes,
It was actually difficult to uniformly melt and knead this into liquid polyether using a kneader such as that described in the above-mentioned document. That is, when kneading is attempted using a two-roll or twin-roll type mixer, the resin is not completely crushed between the rolls or blades, and melting takes a long time, which is not preferable. Furthermore, after kneading, the melt-kneaded product has high fluidity and adheres to the rolls, walls, and blades of the Nigu and is difficult to remove, making it difficult to apply it to actual manufacturing sites.

Furthermore, melt-kneading at such high temperatures has the disadvantage that water acting as a crosslinking agent evaporates and escapes, resulting in insufficient crosslinking.

This invention was made in an attempt to solve these problems.

[Means for solving problems]

The method for producing an adhesive tape or film of the present invention contains at least one hydrolyzable silicon group, and the main chain is essentially represented by the formula -R-0- (R is a divalent alkylene group). A polyether having chemically bonded repeating units and an adhesive resin are placed in a melting pot, the adhesive resin is heated and melted in the melting pot, and mixed with the polyether, and the mixed melt is cross-linked. It is characterized by adding and mixing an accelerator and applying it to a substrate in a temperature range of 40°C to 160°C under humidified steam for crosslinking.

In this invention, the hydrolyzable silicon group in the polyether is a hydride group bonded to a silicon atom, a halogen group,
These include an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, an alkenyloxy group, an alkenyloxy group, a mercapto group, and the like.

Further, R in the main chain of the polyether is a divalent alkylene group, and preferably has 1 to 4 carbon atoms.

In this invention, the adhesive resin is compatible with polyether, and includes rosin resins such as rosin, rosin ester, and hydrogenated rosin, modified phenolic resins such as phenol resins, terpene-phenol resins, xylene resins, and petroleum resins. Examples include resin, terpene resin, chroman resin, etc. The amount added is 5 to 140 parts by weight per 100 parts by weight of polyether.

In this invention, in addition to the adhesive resin, additives used in ordinary solvent-free adhesive resin compositions, such as anti-aging agents, pigments, plasticizers, etc., can be added.

The heating temperature and crosstalk time in the melting pot are sufficient to melt the adhesive resin, but usually 80 to 16
0°C for several tens of minutes to several hours. In addition, in order to suppress oxidative decomposition of polyether and the like, the melting pot may be treated under a nitrogen atmosphere.

Organotin compounds etc. are preferably used as crosslinking accelerators,
After the adhesive resin is dissolved and mixed in polyether, this is added and mixed and applied to the base material. For this coating, a conventional coating method is appropriately adopted.

During the above coating, the temperature of the coated material is preferably 40 to 160[deg.] C. using high-temperature humidified steam such as water vapor. This is because the high temperature humidified steam supplies moisture as a crosslinking agent and maintains the temperature of the coated material during coating and crosslinking.

[Example 1] 100 parts by weight of polyether (MS Polymer #30Q, Sa!Fuchi Chemical Industry Co., Ltd.), adhesive resin (YS Polyster T)
100 parts by weight of -115 terpene-phenolic viscous f +1 fat, Yasushi Oil Co., Ltd.), 0 and 5 parts by weight of an ultraviolet inhibitor, and 3.5 parts by weight of an anti-aging agent were placed in a melting pot, and heated at 150°C in a nitrogen stream. The mixture was heated and mixed for an hour. This mixture remained homogeneous without separation of the resin even when cooled to room temperature.

Next, 3i parts of a crosslinking accelerator (organotin compound; 1010 manufactured by Kanekabuchi Chemical Co., Ltd.) was mixed into this mixture, and then
This molten mixture was applied to a base material (50μ polyester film) to a thickness of 110-120μ using an applicator, and this was placed in a humidified oven at 90°C (25% RH for 3 minutes and 65% RH for 1.5 minutes) to form an adhesive layer. was crosslinked by heating and humidifying. In all of the obtained adhesive films, the adhesive layer was crosslinked and no stickiness was observed in the coating film, and the adhesive layer was 25% RH.
In the case of a minute, the tank (1/32l) is 13.13, sp
Adhesive strength (g/15 dragon width) is 1400, 65% RH
In the case of 1 and 5 minutes, it was 15.16.1700, respectively.

[Example 2] Example 1 except that the anti-aging agent in the formulation was 2.5 parts by weight.
2 parts by weight of the same crosslinking accelerator as in Example 1 was added to a molten mixture of polyether and adhesive resin obtained in the same manner as in Example 1, and the mixture was extruded from a T-die mold using a Honmelt Mini Coater to form a polyester film (50μ). Apply to a thickness of 130μ,
This was heated and humidified in a humidified oven at 90° C. and 65% RH for 1.5 minutes and 3 minutes, respectively. In all of the obtained adhesive films, the adhesive layer was crosslinked and no stickiness was observed in the coating film, and the tack (1/32") was 11 at 1.5 minutes.
The sp adhesive strength (g/15 dragon width) was 1000, and in the case of 3 minutes, it was 15.1200, respectively.

[Operation and effects of the invention]

In this invention, the adhesive resin is completely melted in a melting pot and mixed with liquid polyether to form a homogeneous mixture.

In addition, by adding and mixing a crosslinking accelerator to this mixture and applying it to the substrate under humidified steam at a temperature range of 40°C to 160°C, the water as a crosslinking agent that is dissipated in the melting pot can be replenished. As a result, a good pressure-sensitive adhesive layer without stickiness of the coating film can be easily formed.

Claims (1)

[Claims] 1. A polyether containing at least one hydrolyzable silicon group and having chemically bonded repeating units whose main chain is essentially represented by the formula -R-O- (R is a divalent alkylene group). The adhesive resin is placed in a melting pot, the adhesive resin is heated and melted in the melting pot, and mixed with the polyether. A crosslinking accelerator is added and mixed to the mixed melt, and the mixture is heated at 40° C. or higher under humidified steam. A method for producing an adhesive tape or film, which comprises applying the adhesive to a base material and crosslinking it in a temperature range of 160°C.