JPS5893774A - Preparation of pressure-sensitive adhesive film or sheet - Google Patents

Abstract

PURPOSE:To prepare the titled urethane-base pressure-sensitive adhesive material showing no change in adhesive properties with time, by coating a mixt. of polyol and polyisocyanate on a base film or sheet and treating it with water after completion of interaction of the two compds. CONSTITUTION:A mixt. of polyol containing two or more hydroxyl groups and pref. having an average molecular weight of 500-10,000 (e.g. polyoxypropylene glycol) and polyisocyanate (compd. having two or more isocyanate groups, e.g. 2,4-toluene diisocyanate, 2,6-toluene disocyanate or mixt. thereof) pref. in the isocyanate group/hyroxyl group eq. ratio of 0.7-1.50, is coated on a base film or sheet, followed by treatment with water after completion of interaction of the polyol and the polyisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a highly pressure-sensitive adhesive tape or sheet using a urethane-based pressure-sensitive adhesive.

The adhesive used for pressure-sensitive tapes or sheets is 9-adhesive, which is made by Uranami Polymer Co., Ltd. and Emulsion Juukin Co., Ltd., but the former uses a large amount of organic solvent, so it is problematic in terms of safety, health, and pollution. This method is problematic in that large-scale equipment is required for drying and recovering the solvent, and a large amount of energy is required for the evaporation of moisture in the hands of an unskilled person.

As a ninth solution to the above-mentioned drawbacks, Frethane pressure-sensitive adhesives have recently been studied. Frethane pressure-sensitive adhesives are made by cross-linking polyol and polyinsyanate, and do not contain solvents such as organic solvents or water, so they are suitable as adhesives for pressure-sensitive adhesive tapes and mesh sheets that have the above-mentioned drawbacks. However, it had the disadvantage that the adhesive properties changed over time. In particular, the change over time was severe in Kutai due to the addition of phenolic tackifier.

The present invention addresses the above-mentioned drawbacks, and the adhesive properties do not change over time.
Pressure-sensitive adhesive tapes or sheets using Frethane-based pressure-sensitive adhesives, especially when phenol is added to Frethane-based pressure-sensitive adhesives.
The object of the present invention is to provide a method for producing a pressure-sensitive adhesive tape or sheet using an adhesive to which an S/IK tackifier is added, the gist of which is to apply a mixture of polyol and polyisocyanate to a substrate. The present invention also provides a method for producing a pressure-sensitive adhesive tape or sheet, characterized in that the polyol and polyincyanate are subjected to water treatment after Kw5 termination.

The polyol used in the present invention is a compound having two or more hydroxyl groups and #i? The average molecular weight is SOO~toooo, preferably 1000~5oo
Wave-like products or liquid products that can be heated at ~100°C, such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene-polyoxypropylene glycol, polyoxytrimethylene glycol, and polyoxypropylene glycol. Polyether diols such as oxytetramethylene glycol, polyoxybutylene glycol and mixtures thereof; polyether triols such as polyoxypropylene triol and polyoxyethylene-polyoxypropylene triol.

Trinotyrolpropane, chrycerin, pentaerythritol, etc. are co-condensed into the molecules of the polyether diols to produce polyether polyols such as round ones or mixtures thereof, polypropylene glycol, dipolypropylene glycol, L4-butanediol, L6-hexyl, etc. Low molecular weight glycols such as Nanediol and 7-talic acid.

Sales of polyester polyols such as condensates with difunctional organic acids such as adipic acid, maricyclic polymers of ε-cablocktone, butadiene homopolymers having hydroxyl groups at the end of the molecule,
There are rumors of liquid rubbers such as butadiene-styrene copolymer and butadiene-1-crylonitrile copolymer.

Polyincyanate #i used in the present invention is a compound having two or more incyanate groups, for example 2
．． 4-) Toluene diisocyanate and 2.6-toluene diisocyanate or mixtures thereof-11. s-natylene diisocyanate, xylylene diisocyanate,
4,4'-diphenylmethane diisocyanate, inline diisocyanate, hexamethylene diisocyanate
-), aliphatic, aromatic or alicyclic diincyanate such as 4,4'-dicyclohexylmethane diincyanate and mixtures thereof, 4°4',4'-)liphenylmethane triisocyanate, 1 mol of trimethylolpropane and tri- or tetraisocyanates which are addition compounds from 3 mol of toluene diisocyanate or from 1 liter of pentaerythritol and 4 mol of toluene diisocyanate.

In the present invention, the above polyol and polyisocyanate are mixed, and the resulting mixture is applied to a substrate.

The ratio of the polyol to the polyisocyanate is preferably from a1 to 150, more preferably from L85 to L25, based on the equivalent ratio of (isocyanate group/hydroxyl group).

The base material may be any material commonly used as a base material for adhesive tapes or sheets, such as plastic films such as polyethylene, polypropylene, polyvinyl chloride, and polyester, stretched glass films, paper, and cloth. etc. can be mentioned.

Further, any coating method may be used, for example, a knife coater, a roll coater, etc. may be used to coat the base material to an appropriate thickness.

In the above-mentioned 114-product, the hydroxyl group and isocyanate group of the polyol and polyinsyanate react to form a phletane compound, but a reaction catalyst may be added to promote the reaction.

Examples of the above-mentioned anti-ToIIlkls include dibutyl chloride, octene, lead octenoate, triethylenediamine, and triethylamine.

In addition, the above mixture Ksyale resin, tilbenzenol resin, and phenol are copolymerized to produce nine coumaron-indene resin, rosin, rosin ester type tackifier, filler material, UV quenching agent, antioxidant, softener, etc. May be added.

In the present invention, the mixed metal is applied to the base material and reacted,
After the reaction is completed, it is treated with water to produce a pressure-sensitive adhesive tape or sheet.

Although the above reaction proceeds even at low temperatures, it is accelerated at high temperatures. Therefore, in order to terminate the reaction, it is preferable to perform simultaneous heating at 100 to 140° C. for 2 to 10 minutes. And the reaction ends 1
Although 0 is treated with water in 1, it may be immersed in water 1 & NFi water, it may be brought into contact with Kimoto 9ILK, or the atmosphere may be maintained at a high temperature. Note that high humidity preferably means a relative temperature of 95% or higher. Further, the water treatment time may be determined as appropriate, but it is preferable that the water treatment be carried out for 2 to 20 minutes.

The manufacturing method of the present invention is as described above, and since the main treatment is carried out after the reaction between the polyolefin and the polyisocyanate, the easily liberated incyanate groups and low molecular weight incyanate in the adhesive are Since it reacts and forms a strong urethane bond, free incyanate groups are not generated over time, and the adhesive properties deteriorate over time. When a tackifier having a phenol group is added to the inocyanate base, the tackifier reacts with the phenol group of the incyanate group, and this incyanate group is easily liberated, causing assimilation over time. The group and water react to form a strong urethane bond, and the incyanate group is not released over time.A pressure-sensitive adhesive tape or sheet that does not change over time is produced.

Next, the present invention will be illustrated by examples. In addition, below simply rl
lJ means "parts by weight".

The method for measuring physical properties is as follows.

+11SP Adhesive Car Stainless Steel & Kft) 10
Paste the sample of ■, press it with a 2kII rubber roll 5 times and leave it for 15 minutes.
Remove the excess and measure the peel strength.

(Gel fraction The pressure-sensitive adhesive was immersed in Tetokuhydro 7 Run at 40°C for 48 hours and expressed as the percentage of insoluble matter.

Example 1 Comparative Example 1.2 Polyoxylepropylene glycol with average molecular weight xooo (manufactured by Mitsui Nisso Rethan Co., Ltd., Di・1-'!Goo) 10
0 parts and tolylene diisocyanate (manufactured by Kurade Pharmaceutical Industry Co., Ltd.,
17.4 parts of tuffnate 80) were mixed to obtain a prepolymer (A) having isocyanate at both ends. Average molecular weight 2
100 parts of 000 Polio Ima Shitetotsumethylene glycol (PPG-500, manufactured by Nippon Furetane Co., Ltd.), f-rubenphenol resin (softening point: approximately 130°C, manufactured by Yasushi Oil Co., Ltd., 'll)
5d19:1. ter 1130) Sell.

Dibutyltin thick rate Q1, ultraviolet Jllil yield period (
Manufactured by Ciba Geigy, TINtlVIN3!7)
g) 3 parts of a were mixed to obtain a mixed solution (wave B).

A fluid obtained by mixing 4 parts of 9 tons of A wave, 150 parts of B wave, and 2 parts of diphenylmethane diincyanate (average functional group: about 14, manufactured by Peyer Cretan Co., Ltd., Sumidur 44V20) (isocyanate group/ Hydroxyl group (equivalent ratio LO) was coated on a 2hfi thick polyester film to a thickness of SO with a roll coater, heated at 120°C for 6 minutes to complete the reaction, and then the tape was formed.

The obtained tape was measured by infrared absorption spectrum, and there was almost no absorption of incyanate groups at all.

Next, it was immersed in warm water at 80° C. for 10 minutes to obtain a pressure-sensitive adhesive tape. The rolled tape was stored at a constant temperature of 60° C. with a relative humidity of 60%, and the KSP adhesive strength and dull fraction were measured after production, 5 days, and 20 days, and the results are shown in Table 1. (Comparative Example 1) The above tape was heated at 80'C for 12 hours and measured in the same manner, and the results are shown in Table 111. (Comparison #v2) IB1 Table Patent Applicant Sekisui Chemical Co., Ltd. Representative s IB Motori

Claims (1)

[Claims] 7) A method for producing a pressure-sensitive adhesive tape, which comprises applying a mixture of a polyol and a polyisocyanate to a base material, and treating the mixture with water after the reaction between the polyol and the polyisocyanate is completed.