JPS6281468A - Alpha-cyanoacrylate adhesive composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent adhesive, tensile shear strength, peel strength, heat resistance, water resistance, moisture resistance, etc., by mixing an alpha-cyanoacrylate, pyrogallol, and a urethane rubber. CONSTITUTION:100pts.wt. alpha-cyanoacrylate of formula I [wherein R is a (halo) alkyl of 16C or less, an alkenyl, an aralkyl, cyclohexyl or phenyl] is mixed with 0.001-0.5wt% pyrogallol of formula II and 1-50wt% urethane rubber and, if necessary, a stabilizer, a polymerization inhibitor, a thickening agent, etc., are added to this mixture, giving an alpha-cyanoacrylate adhesive composition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention provides improved high adhesive strength, especially tensile shear strength, peel strength and impact peel strength, consisting of α-cyanoacrylate, pyrogallol and urethane rubber; The present invention relates to an α-cyanoacrylate adhesive composition having excellent heat resistance, water resistance, and moisture resistance.

(Prior Art) Conventionally, α-cyanoacrylate is represented by the general formula 〇N CTl 2= (';-G OOR (in the formula, R represents alkyllkyl, cyclohexyl, phenyl, etc. having 16 or less carbon atoms). It is easy to undergo anionic polymerization, and it can be polymerized for several seconds to several minutes at room temperature without using a catalyst by various anionic active substances such as moisture attached to the solid surface, atmospheric humidity, and other alkaline substances. It has the property of polymerizing and curing in a short period of time.

Therefore, it is widely used for both industrial and consumer purposes as an instant adhesive for bonding rubber, plastics, metals, glass, ceramics, wood, etc.

(Problems to be Solved by the Invention) However, this α-cyanoacrylate adhesive has poor peel strength, impact peel strength, and heat resistance, water resistance, and moisture resistance of the adhesive layer after adhesion, and therefore Easier depending on stress and usage environment. However, there are drawbacks such as deterioration of adhesive strength and exposure of peeling phenomenon, and these drawbacks have limited the objects to which they can be used, especially in industrial applications.

On the other hand, as a method for improving the adhesive strength of α-cyanoacrylate-1-based adhesives, for example, JP-A-57-78469 discloses that pyrogallol is added to α-cyanoacrylate by 1%.
Added ~5000ppm to improve adhesive strength and impact resistance.
However, as will become clear from Test 1 below, there are problems with its adhesive strength, especially its heat resistance, water resistance, and moisture resistance, which limits its use in actual use. Therefore, this improvement was desired.

(Means for Solving the Problems) The present inventors have conducted extensive research to improve the adhesive strength, etc. of conventional α-cyanoacrylate adhesives as described in 1. The addition of urethane rubber provides excellent adhesive strength, especially tensile shear strength and impact peel strength, as well as heat resistance, water resistance, and V411 resistance.
The present invention was achieved by discovering that an α-cyanoacrylate adhesive composition exhibiting excellent properties such as properties can be obtained.

That is, the present invention provides α-cyanoacrylate 1 no 1 ~,
Improved α consisting of pyrogallol and uretango 11
-Cyanoacrylate-1 adhesive composition.

The α-cyanoacrylate-1. which can be used in the present invention is represented by the above general formula, and the stabilizer is a known stabilizer, that is, S02. SOL, para-toluenesulfonic acid, methanesulfonic acid, sultone, boron trifluoride ether, etc. can be used.

As the polymerization inhibitor, hydroquinone, berezoquinone, catechol, alkylphenol, etc. can be used.

In addition, polymers and oligomers known as thickeners, such as polymethyl methacrylate, polyvinyl acetate,
The addition of polystyrene, polyα-cyanoacrylate, polyethylene glycol, polymethyl vinyl ether, etc., and the addition of inorganic thickeners such as finely powdered silica are also 11r functions. Further, depending on the case, it is also possible to add solvents, plasticizers, accelerators, colorants, etc. to α-cyanoacrylate-1 without deteriorating the physical properties of the composition or impairing storage stability.

Pyrogallol that can be used in the present invention has the chemical formula:
- Based on 100% (weight) of cyanoacrylate, its content is 0.001-0.5% (weight), preferably 0
．． 01-0.2% (weight).

Urethane rubber that can be similarly used is generally a polymer called thermoplastic urethane rubber, urethane elastomer, urethane prepolymer, or unvulcanized urethane rubber, as long as it exhibits rubber elasticity and is soluble in α-cyanoacrylate monomer. good. The amount added may be 1 to 50% (weight), preferably 5 to 20% (weight), based on 100% (weight) of the above-mentioned α-cyanoacrylate.

(Function) The adhesive composition according to the present invention obtained as described above is an improved α-cyanoacrylate adhesive composition due to the mutual synergistic effect of the α-cyanoacrylate, pyrogallol, and urethane rubber. It is of high practical value as it exhibits excellent adhesive strength, especially tensile shear strength, peel strength, and impact peel strength, as well as heat resistance, water resistance, and moisture resistance, and excellent storage stability. be.

(Example) Examples will be explained below.

(Example 1) 100% (by weight) Cyanon S (a product of the applicant's company, a trade name of α-cyanoacrylate adhesive containing ethyl α-cyanoacrylate as a main component) was mixed with Iron Rubber (a product of the NOK company in Japan). , trade name of urethane unvulcanized rubber) 2
0% (weight μ) is added and dissolved by heating at a temperature of 60 to 70°C to make a homogeneous solution, and 0°001 to 0.5% (weight) of pyrogallol is added to this solution and dissolved, This was used as a test sample. As comparative examples, a conventional product containing only cyanon S and a conventional product containing cyanon S with iron rubber added thereto were adopted.

The characteristics test results for each test sample are shown in Table 1.

(Left below) [Notes] ■Viscosity: Measured using a Brook field rotational viscometer ■Cerato time: Compliant with JIS K6861, adherend is steel ■T-type peel strength:. Compliant with TTS K6854, adherend is like steel ■Impact peel strength: Compliant with JIS K6855, adherend is like steel ■Tensile shear strength: Compliant with JIS K6861, adherend is like steel ■Heat resistance = 1. Measured after being heated for 5 hours and left to cool at room temperature ■Water resistance: Measured after being immersed in water at 40℃ for 7 days ■Moisture resistance: Measured after being treated at 40℃ x 90% RH for 7 days As shown in the display: The properties of the product according to the present invention, such as peel strength, impact peel strength, heat resistance, water resistance, and moisture resistance, are significantly improved compared to conventional products. ) or more is undesirable because it leads to discoloration of the product and a decrease in set time and heat resistance.

If the amount is less than 0.001% (by weight), the effect will be small and meaningless.

(Example 2) Cyanone 8100% (weight) and pyrogallol 0.1
% (weight) of iron rubber in a mixed solution at 60-70℃
The composition was prepared by heating and dissolving at a temperature of 100 to prepare a homogeneous solution, which was used as a test sample.

In addition, as comparative examples, a conventional product containing cyanone S alone and a product containing cyanone S with pyrogallol added thereto were adopted.

(The following is a blank space) As shown in Table 2, due to the addition of iron rubber, the product according to the present invention has improved peel strength, impact peel strength, heat resistance, water resistance, moisture resistance, etc. by 11 points compared to conventional products. Although an improvement can be seen, adding more than 30% (overlapping) of iron rubber to the composition is not preferable because the viscosity of the composition becomes too high and the coating operation becomes difficult; weight), the effect will be weak and meaningless.

(Example 3) Cyanone 8100% (weight) and pyrogallol 0.1%
(weight) to the mixed solution, ■, U P HE N P11
'IO,P]1], 2. P], 320 (West German BASF
15% (weight) of urethane rubber product name) in each product.
A composition was prepared as a uniform solution by heating and dissolving at a temperature of 60 to 70° C., and used as a test sample. In addition, as a comparative example, the above-mentioned Cyanon S Ill exclusive product was adopted as a conventional product.

(The following is a blank space) Table 3 As shown in Table 3, the product according to the present invention is L U P
By adding each number product of TI E N, remarkable improvements in peel strength, impact peel strength, heat resistance, water resistance, etc., similar to those of the iron rubber, were observed.

(Effect of the invention) As is clear from the above explanation and examples, the present invention has α
- Since it is an α-cyanoacrylate adhesive composition consisting of cyanoacrylate, pyrogallol, and urethane rubber, it ensures high adhesive strength due to the synergistic effect of the α-cyanoacrylate, pyrogallol, and urethane rubber, Deterioration of adhesive strength under various environmental conditions, which is a problem with conventional products, especially tensile shear strength, peel strength,
In addition to eliminating deterioration in impact peel strength and the like, it is also possible to significantly improve properties such as heat resistance, water resistance, and moisture resistance.

Therefore, the poor workability and restrictions on the working range of the conventional α-cyanoacrylate adhesives are significantly improved, and the adhesive exhibits remarkable effects such as contributing to the expansion of its uses.

Claims (1)

[Claims] 1. An α-cyanoacrylate adhesive composition comprising α-cyanoacrylate, pyrogallol, and urethane rubber. 2. Claim 1 consisting of pyrogallol 0.001-0.5% (weight) and urethane rubber 1-30% (weight) based on 100% (weight) α-cyanoacrylate
The α-cyanoacrylate adhesive composition described in Section 1.