JPS6116977A - Adhesive composition - Google Patents

Abstract

PURPOSE:The titled composition that is a combination of 2-cyanoacrylate which contains specific amounts of cyanoacetate, alcohol and water and has a specific chemical structure, with an anion polymerization inhibitor, thus showing high adhesion strength, good instant adhering properties and high storage stability. CONSTITUTION:The objective composition is obtained by using a 2-cyanoacrylate of formula I (R is 2-4C alkylene; R' is 1-6C alkyl) or formula II such as 2-methoxyethyl-2-cyanoacrylate, which includes less than 5wt% of cyanoacetate, less than 5wt% of alcohol and 0.02-0.2wt% of water, and an anion polymerization inhibitor such as SO2, and, when needed, a radical polymerization inhibitor such as hydroquinone. EFFECT:It is free from bad odor and whitening.

Description

[Detailed description of the invention] This is related to adhesives that can be used in a variety of ways.

In general, 2-cyanoacrylate adhesives harden instantly at room temperature due to the small amount of moisture adsorbed on the surface of the adherend, so they are used in various industrial fields to bond metals, plastics, rubber, glass, etc. It is widely used in However, conventional adhesives using alkyl-2-cyanoacrylate have an odor and tend to cause a whitening phenomenon on the surface of the bonded object, which looks like white powder has been sprayed on the bonded area. .

The present invention provides an adhesive that does not have these drawbacks, that is, an adhesive composition that has adhesive properties such as excellent adhesive strength and instant adhesive properties, has excellent storage stability, and is free from odor and whitening phenomenon. It is something to do.

The present inventors focused on 2-alkoxy-2-cyanoacrylate having an ether group as a potential adhesive without the above-mentioned drawbacks, and investigated adhesives using it.

For this purpose, for example, typical 2-alkoxyethyl-2-
Cyanoacrylate was produced by the following alkyl-2-cyanoacrylate production method that has been widely adopted in the past, and an adhesive was produced using the same.

That is, 2-alkoxyethylcyanoacetate is charged in a range of 0.9 to 1.1 mole per mole of paraformaldehyde, and basic substances such as piperidine, amine ethanol, diethylamine are charged in a range of 0.001 to 1.1 mole to 1 mole of paraformaldehyde. 0.01 mole processing, reaction in an organic solvent such as toluene, xylene, benzene, trichlorethylene, etc. until a theoretical amount of water is produced, then the solvent in the reaction solution is distilled off under reduced pressure to form a highly viscous composition. get things,
An acidic substance such as phosphorus pentoxide or phosphoric acid was added thereto in an amount of 0.5 to 5% by weight based on the condensate, and the mixture was heated under a reduced pressure of 0.5 to 11011H for 150 to 250 hours. ℃
was depolymerized to produce 2-alkoxy-2-cyanoacrylate.

However, in the conventional method as described above, 2-
Because the repolymerization of alkoxyethyl-2-cyanoacrylate in the gas phase (polymerization in the condenser) is more remarkable than that of alkoxyethyl-2-cyanoacrylate, the yield is 10 to 2.
As a result of gas chromatography analysis, the purity was as low as 70-80%, and a large amount of impurities such as 2-alkoxyethylcyanoacetate and 2-alkoxyethanol were detected. No matter how much 2-alkoxyethyl-2-cyanoacrylate produced by this method is distilled and purified, the adhesive using 2-cyanoacrylate obtained therefrom does not exhibit excellent adhesive performance and storage stability. It was extremely low.

The reason why this phenomenon occurs is not clear, but it is probably due to 2
This is thought to be due to the difference in chemical structure between -alkoxyethyl-2-cyanoacrylate and alkyl-2-cyanoacrylate, and if a substance that promotes abnormal decomposition during depolymerization is present, the 2-alkoxyethyl group decomposes abnormally. Ethers or alcohols that promote polymerization are generated to promote gas phase polymerization, and 2-alkoxyethyl-2-
In addition to the synergistic effect with the autocatalytic action due to the ether bond of cyanoacrylate itself, it is thought that it exhibits a behavior different from that of alkyl-2-cyanoacrylate.

In addition, the abnormal decomposition at this time is thought to also generate cyanoacetate, and once cyanoacetate is contained in a large amount in 2-alkoxyethyl-2-cyanoacrylate due to the depolymerization reaction, the boiling points are very close to each other. This is also because it is difficult to purify it by distillation.

The reason why 2-alkoxyethyl-2-cyanoacrylate cannot be used as a raw material for adhesives is that 2-alkoxyethylcyanoacetate and 2-alkoxyethanol are mixed in during manufacturing, and these affect its performance as an adhesive. Since it was thought that this impurity would have a negative effect on adhesive strength, instant adhesiveness, storage stability, etc., the present inventors investigated these impurities and found that 5% by weight of 2-alkoxyethyl cyanacetate and 2-alkoxyethanol.
It has been found that adhesives using 2-cyanoacrylate exposed to a temperature exceeding 1000 nm rapidly exhibit the above-mentioned performance and become virtually unusable as adhesives.

Furthermore, they discovered that trace impurities in the condensate affect depolymerization, resulting in poor quality products, and completed the present invention.

The present inventors also use alkyl or cycloalkyl-2 having an ether group, typified by 2-alkoxyethyl-2-cyanoacrylate. That is, in the production method, before entering the depolymerization step of the condensate, the viscosity of the condensate is maintained within a certain range and trace amounts of impurities that are by-products or mixed in the condensation reaction that promote abnormal decomposition are removed or reacted. It has been found that by depolymerizing after erasing, depolymerization easily proceeds and 2-cyanoacrylate with few impurities can be obtained.

The present invention has a cyanacetate content of 5% by weight or less, an alcohol content of 5% by weight or less, and a water content of -jiO,02
General formula CH,=C-C0O-R- with a weight coefficient of ~0.2
0-R' (where R is an alkylene group having 2 to 4 carbon atoms and R' is an alkyl group having 1 to 6 carbon atoms) or an adhesive composition comprising monocyanoacrylate and an anionic polymerization inhibitor. be.

Specific examples of the alkyl or cycloalkyl-2-cyanoacrylate having an ether group represented by the above formula in the present invention include 2-methoxyethyl-2-cyanoacrylate, 2-ethoxyethyl-2-cyanoacrylate, 2-propoxyethyl-2-cyanoacrylate, 2-butoxyethyl-2-cyanoacrylate),
2-hexyloxyethyl-2-cyanoacrylate,
6-Medoxybutyl 2-cyanoacrylate, 2-ethodiptyl-2-cyanoacrylate, 3-methoxypropyl-2-cyanoacrylate, 2-methoxypropyl-2-cyanoacrylate, 3-amyloxyethyl-
2-cyanoacrylate, tetrahydrofurfuryl-2
- cyanoacrylates, etc.

The 2-cyanoacrylate has a cyanoacetate content as an impurity of 5% by weight or less, preferably 2% by weight or less, more preferably 1% by weight or less, and an alcohol content of 5% by weight or less, preferably 2% by weight. The water content should be less than or equal to 1 weight percent, and the water content should be 0.02 to 0.2% by weight, preferably 0.06 to 0.15% by weight.
It needs to be very important. By using such 2-cyanoacrylates, adhesive compositions of high quality and excellent stability can be obtained for the first time, and such adhesives cannot be obtained with conventional adhesives, resulting in poor quality. It was just a stable thing.

It can be easily produced by the following method discovered by et al.

That is, the general formula % formula % (where R is an alkylene group having 2 to 4 carbon atoms, R'
is an alkyl group having 1 to 6 carbon atoms) The viscosity of the condensate of cyanoacetate and formaldehyde is 1 to 500.
The cyanoacetate content was reduced to 5% by carrying out a depolymerization reaction after washing with water or an acidic aqueous solution while maintaining the centiboide range, and by purifying the obtained product droplessly to 5%.
-N whose weight is less than 5% by weight, alcohol content not more than 5% by weight, and water content from 0.02 to 0.2% by weight General formula CH2=C-C0O-R-0-R' (However, R
is an alkylene group having 2 to 4 carbon atoms, and R' is an alkylene group having 1 to 4 carbon atoms.
6) or monocyanoacrylate are easily obtained.

Here, the general formula NC-CH2-C0O-R-0-R'(
However, R is an alkylene group having 2 to 4 carbon atoms, and l' is an alkyl group having 1 to 6 carbon atoms).The cyanoacetate specifically includes 2-methoxybutylcyanoacetate,
2-Ethoxyethylcyanoacetate, 2-propoxyethylcyanoacetate, 2-butoxyethylcyanoacetate, 3-methoxybutylcyanoacetate, 3-
Methoxypropylcyanoacetate, 2-methoxypropylcyanoacetate, 2-hexyloxyethylcyanoacetate, 4-ethoxybutylcyanoacetate,
These include 2-amyloxyethyl cyanacetate and tetrahydrofurfuryl cyanacetate.

The above manufacturing method will be explained in more detail below. The condensate of cyanacetate and formaldehyde represented by the above general formula is obtained by a condensation reaction in the presence of a base catalyst. Catalysts include amines such as piperidine, NaOH
A basic compound such as , KOH, or alkali metal alkoxide is reacted with cyanacetate in an amount of 0.01 to 10 mol.

The molar ratio of cyanoacetate and formaldehyde is 1
:0.7 to 1.3, particularly a molar ratio of 1:10 is suitable. A solvent is usually used in the condensation reaction, and inert solvents such as benzene, toluene, alcohol, chloroform, trichloroethylene, tetrahydrofuran, and water are used.

In this case, it is also possible to use two-component solvents such as water and toluene. The amount of solvent used is preferably 50 to 3001111 per mole of cyanacetate. The condensation reaction temperature ranges from 60 to 150°C, especially from 50 to 100°C.
A reflux temperature of °C is suitable. Reaction time is several hours to 2
4 hours is appropriate. The condensation reaction product of cyanoacetate and formaldehyde contains a condensation catalyst, unreacted raw materials, acid, alcohol, reaction by-products, low condensate, etc. in small to trace amounts, and is a highly viscous or brittle solid.

In order to obtain the desired high-purity 2-cyanoacrylate, it is necessary to wash this condensate with an aqueous acid solution or water, and although the reason for this is unknown, the viscosity of the condensate at the time of washing is 1 to 500 centivoise. Preferably 20-250
An important condition is to keep the viscosity within the centivoid range; if the condensate is washed outside this viscosity range, the next depolymerization will be difficult, and even if depolymerization is possible, it will not result in good quality 2-
Cyanoacrylates are not available.

The viscosity of the condensate is 1 to 500 centivoise, preferably 2
As a method of keeping the condensate at 0 to 250 centivoise,
By raising the temperature to about 00°C, or during the condensation reaction, solvents such as aromatic hydrocarbons such as benzene and toluene, ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ethyl acetate, and butyl acetate can be removed. A method of using solvents such as esters such as esters, chlorinated hydrocarbons such as trichlorethylene and dichloroethane, ethers such as methyl ether, and furan compounds such as tetrahydrofuran, or diluting the condensate with these solvents. will be adopted.

The temperature during washing is carried out in the range of 0 to 100°C. Acids used for cleaning include sulfuric acid, hydrochloric acid, phosphoric acid, halatoluenesulfonic acid, benzenesulfonic acid, formic acid, acetic acid, etc., which dissolve in water and exhibit acidity, and the concentration used is 0.01 to 5%. A range of is preferred.

The condensate washed under these conditions is depolymerized by a conventional method. That is, in the presence of an N polymerization catalyst such as P2O, phosphoric acid, condensed phosphoric acid, etc., the crude monomer is depolymerized by heating to a temperature in the range of 100 to 250°C, preferably 140 to 200°C under vacuum, to obtain a crude monomer in a good yield. obtain.

High quality alkyl or cycloalkyl, =3-cyanoacrylates containing ether groups can be obtained by redistilling this crude monomer.

The anionic polymerization inhibitor in the present invention is, for example, SO□,
It is an anionic polymerization inhibitor of known 2-cyanoacrylates such as SO3, SOCl, , HF, BF, , para-toluenesulfonic acid, methanesulfonic acid, phosphoric acid, trichloroacetic acid, and sultone, and at least one of them is 1000 ppm, preferably 1 to i o o p
pm to form an adhesive composition.

In addition, in some cases, at least one kind of radical polymerization preventive agent such as hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, etc.
It is preferable to use 0 ppm, particularly preferably 50 to 500 ppm, in combination to form an adhesive.

The 2-cyanoacrylate represented by the above general formula in the present invention has a slightly increased viscosity (5 to 40 centivoise), but in order to further increase the viscosity, prepolymers of polymethyl methacrylate, polyacetate-cellulose, and diallyl phthalate are used. etc. to 2-cyanoacrylate.
It can also be added in a range of 5 to 10% to increase the viscosity.

The adhesive composition of the present invention has a fast adhesion speed and high adhesive strength, and has a wide range of uses as an industrial or general instant adhesive. That is, it has great advantages over conventional alkyl-2-cyanoacrylates because it causes less whitening during adhesion and is completely free of irritation.

The following description will be made based on reference examples and examples. Parts and parts are based on weight.

Reference Example 1 60 parts of paraformaldehyde and 20 parts of toluene were placed in a four-eye flask equipped with a stirrer, thermometer, water separator, and dropping funnel.
0 parts and 0.2 parts of piperidine were added, and 2-ethoxyethylcyanoacetate 314 was heated to 80 to 90°C with stirring.
part was dripped.

After the dropwise addition, the mixture was allowed to react under reflux while expelling the water produced until a theoretical amount of water was produced, and then cooled to room temperature. To the resulting condensate having a viscosity of 200 cp, 300 parts of a 1% aqueous solution of para-toluenesulfonic acid was added, and the mixture was shaken at 70°C, and when left to stand, it would separate into two layers, so the oil layer was separated.

After distilling off the toluene in the oil layer under reduced pressure, 6 parts each of phosphorus pentoxide and hydroquinone were added to the condensate in the pot.
Depolymerization occurred when heated to 150 to 200"C under a reduced pressure of 5 mHg, yielding 266 parts of a crude monomer (yield: 83 cm). The purity of this product was 96.8%, containing all 2-ethoxyethyl 2- The total amount of cyanacetate: 0.50%, 2-ethoxyethanol: 1.20%, water: 0.15%, and other impurities was 13%.

Next, 0.5 g each of phosphorus pentoxide and hydroquinone were added to the crude monomer and redistilled, resulting in 0.48% of 2-ethoxyethylcyanoacetate and 0.50% of 2-ethoxyethanol. , boiling point 10 containing 0.05% water
0~b Proverb 1■, purity 98. 220 parts of 2-ethoxyethyl-2-cyanoacrylate of El was obtained.

When the condensation liquid was thawed after expelling the toluene, a large amount of polymer adhered to the cooling section and it seemed to be clogging, so we replaced the condenser and continued the reaction.
Similarly, polymerization occurred in the cooling section and the process had to be stopped midway.

65 parts of crude monomer (yield: 11 cm) were obtained in the receiver, the purity of which was 72 cm, and most of the impurities were 2-ethoxyethylcyanoacetate, water and 2-ethoxyethanol, and then re-distilled. However, most of the 2-ethoxyethylcyanoacetate remained, and the purity was only 78%.

17　　　　　　　　　　　　-.

60 parts of aldehyde, 500 parts of benzene, 0.
2 parts were charged, 286 parts of 2-methoxyethylcyanoacetate was added dropwise at 80 to 90°C, and the mixture was reacted under reflux to obtain a condensation liquid. The resulting viscosity at 20°C is 200 cp.
After washing the condensation liquid twice with 200 parts of water, benzene in the oil layer was distilled off under reduced pressure.

Next, 3 parts each of phosphorus pentoxide and hydroquinone were added to the condensate, and the depolymerization reaction was carried out by heating at 150 to 200°C under reduced pressure to obtain 250 parts of crude monomer (yield 85%), and the purity of this product was determined. was 95.5chi.

Adding 0.5% each of phosphorus pentoxide and hydroquinone to the crude mass and redistilling yields 1% 2-methoxyethylcyanoacetate, 0.22% 2-methoxyethanol, and 0.0 water.
200 parts of 2-methoxyethyl-2-cyanoacrylate with a boiling point of 82-86'C/3i+ml' and a purity of 98.6% containing 3% were obtained.

60 parts of aldehyde, 200 parts of toluene, 0.
2 parts were charged, 642 parts of 2-propoxyethyl cyanacetate was added dropwise at 80 to 90°C, and the mixture was reacted under reflux.

A condensate solution with a viscosity of 10 cp to which 400 parts of toluene had been added was washed with 200 parts of a 0.5% sulfuric acid aqueous solution at 20°C, and then 6 parts each of toluene in the oil layer was added under reduced pressure to 150 to 220 parts each under reduced pressure. When heated to ℃ to carry out the depolymerization reaction,
261 parts of crude monomer (yield 75%) was obtained, and the purity of this product was 92.8%.

When 0.5% each of phosphorus pentoxide and hydroquinone were added to the crude single cap and redistilled, 0.56% of 2-propoxyethyl cyanacetate and 0.5596% of 2-propoxyethanol were obtained.
Boiling point 120-126°C/ls including 0.025% moisture
d-th, 2-propoxyethyl-2- with a purity of 98.21%
220 parts of cyanoacrylate were obtained.

60 parts of aldehyde, 200 parts of toluene, 0.2 parts of piperidine
370 parts of 2-butoxyethyl cyanoacetate was added dropwise at 80 to 90°C, and the mixture was reacted under reflux to obtain a condensation liquid.

The thus obtained condensate having a viscosity of 200 cp at 20° C. was washed twice with 200 parts of pure water, and then the toluene in the oil layer was distilled off.

Next, 3 parts each of phosphorus pentoxide and no-hydroquinone were added to the condensate and heated to 170 to 220°C under reduced pressure to carry out a depolymerization reaction, yielding 603 parts of crude monomer (yield 80 cm). The purity of this product was 95.5%.

Adding 0.5% each of phosphorus pentoxide and hydroquinone to the crude monomer and redistilling yields a boiling point of 135 containing 1.02% 2-butoxyethylcyanoacetate, 0.45% 2-butoxyethanol, 0.05% water. ~140℃15yumH
215 parts of 2-butoxyethyl-2-cyanoacrylate with a purity of 98% was obtained.

Examples 1 to 4 and Comparative Examples 1 to 2 2- obtained by the method of Reference Examples 1 to 4 and Comparative Reference Example 1
80.50 ppm for cyanoacrylate.

A forced storage stability test including the adhesion ability of the adhesive obtained by adding 1100 pp of hydroquinone was conducted. The results are shown in Table-1.

For the forced storage stability test, a method was adopted in which each adhesive was placed in a polyethylene container with an internal volume of 2-2, placed in a constant temperature bath at a temperature of 60° C., and the deterioration of the adhesive over time was examined.

However, 50 days of forced deterioration corresponds to about one year if left in a dark place at room temperature.

From the results in Table 1, it is clear that impurities have a very large effect on the storage stability, including the adhesive performance, of adhesive compositions containing 2-alkoxyethyl-2-cyanoacrylate as the main component. be.

Furthermore, the adhesives of Examples 1 to 4 had no odor at all, and no odor or irritating odor was observed even after 50 days of a forced deterioration test (in a constant temperature bath at 60°C).

In addition, in order to investigate the whitening phenomenon, a drop of the adhesives of Examples 1 to 4 and a commercially available adhesive mainly composed of ethyl-2-cyanoacrylate for comparison was placed approximately in the center of a previously cleaned Petri dish, and the lid was placed on the dish. When left at room temperature for a day and night, the latter adhesive turned the entire Petri dish white, whereas the adhesives of Examples 1 to 4 only turned slightly white at the dripping area. there were.

Example 5 50 ppm of para-toluenesulfonic acid and 200 ppm of hyhydroquinone monomethyl ether were added as stabilizers to 2-ethoxyethyl-2-cyanoacrylate obtained by the same method as in Reference Example 1 to produce an adhesive.

In order to investigate the storage stability of this product, a forced deterioration test was conducted by placing it in a constant temperature bath at 60°C, and it was found to have good stability even after 50 days.

Example 6 To the 2-ethoxyethyl-2-cyanoacrylate obtained in Reference Example 1, 1,100 ppm of SO and 100 ppm of hydroquinone were added as stabilizers, and 6 units of methyl methacrylate polymer was added as a thickener to give about 1
Thickened to 0.00 cp. The tensile shear strength of this material is 16
0 to 9/al, which was the same as before thickening. Regarding storage stability, 5O2100pprrL, Hyde O
Ki/7 Add a polymer of methyl methacrylate to ethyl-2-cyanoacrylate containing 10 Dppm to 100
It had the same or better stability than that thickened to cp.

Reference example 5 60 parts of paraformaldehyde, 200 parts of toluene, 3 parts of water
00 parts of monolauryl polyethylene glycol (Bi ethylene oxide), and 2 parts of NaOH were added, and while stirring at reflux temperature, 314 parts of 2-ethoxyethylcyanoacetate (2-ethoxyethylcyanoacetate) was added dropwise. After dropping, the mixture was reacted at the same temperature for 5 hours. The aqueous phase of the reaction solution was separated at 60°C, 300 parts of water was added to the oil phase to give a viscosity of 30 cp at 60°C, and the oil phase was separated by stirring and washing. Perform distillation to obtain 2-ethoxyethylcyanoacetate)0.4
5%, 2-ethoxyethanol 0.68%, water 0.0
205 parts of 2-ethoxyethyl-2-cyanoacrylate containing 5% was obtained.

Example 7 10 ppm of p-toluenesulfonic acid and 200 ppm of hydroquinone were added to the 2-cyanoacrylate obtained in Reference Example 5.
The combined product showed performance and storage stability equivalent to that of Example 1.

Reference Example 6 Tetrahydrofurfuryl cyanacetate (60ml of paraformaldehyde) synthesized by esterifying cyanacetic acid and tetrahydrofurfuryl alcohol while heating 200 parts of toluene and 0.2 parts of piperidine to 80 to 90°C.
338 parts of bP130°C/1mall were added dropwise and reacted.

After the dropwise addition, the reaction was carried out for about 4 hours while distilling off the water produced as a by-product under reflux to obtain a viscous condensate. 200 parts of toluene was added to this condensation liquid to give a viscosity of 40 cp at 20°C, and the mixture was washed with 100 parts of water.

After separating the oil phase and distilling toluene under reduced pressure, 0.3 parts of P and 3 parts of hydroquinone were added to the condensate to form C17.
When depolymerized at 0 to 200°C, 224 parts of crude monomer were obtained. This is re-dropped and bp10B~111℃/
1.5 iod(I) of tetrahydrofurfuryl-2-cyanoacrylate was obtained.

CHN Elemental analysis calculation value 5966chi 6,12chi 7.73
Chi measurement value 59.62% 6.08'! 6 7.8
This 2-cyanoacrylate contained 0.5% tetrahydrofurfuryl cyanoacetate, 0.2% tetrahydrofurfuryl alcohol, and 0.09% water.

Example 8 5o220I to the 2-cyanoacrylate obtained in Reference Example 6
)Pl'll, /'The adhesive containing 200 ppm of hydroquinone is a completely odorless transparent liquid with a viscosity of 1 oocp (20
℃).

Also, the setting time for NBR rubber is 10 seconds, the setting time for steel is 60 seconds, and the tensile shear adhesive strength is 180kl? f/c
rIt (steel) and tensile adhesive strength of 630 kgf (steel), which is the same performance as conventional ethyl-2-cyanoacrylate adhesive.

Similarly, when adhering ABS resin, the ABS resin itself broke when measuring the tensile adhesive strength at a set time of 60 seconds.

Note that no whitening phenomenon was observed with this adhesive.

Reference Example 7 While heating 46 parts of rose formaldehyde, 300 parts of toluene and 0.2 parts of piperidine at 80 to 90°C
Add 258 parts of medoxybutyl cyanoacetate dropwise,
The reaction was allowed to proceed for a period of time, and the water produced was distilled off. To this, 3 toluene
Add 150 parts of water to the condensate solution to make the viscosity 30 cp at 20°C, stir well and wash to separate the aqueous phase, cover the oil phase with toluene, and add P2O53 to the remaining condensate.
part and 15 parts of hydroquinone O, 150-200 parts
Depolymerization was carried out at °C to obtain 140 parts of crude monomer.

This was again dripped to obtain 125 parts of 3-methoxybutyl-2-cyanoacrylate.・bp129~1'52°
It was C/2 to HgΦ and contained 0.14% 3-methoxybutylcyanoacetate, 0.10% 6-medoxybutanol, and 0.08% water, and the purity was 99.5%.

Example 9 80215p to the 2-cyanoacrylate obtained in Reference Example 7
pm and 11,000 pp of hydroquinone were added to prepare an adhesive.

According to Examples 1 to 4, the performance of this adhesive was as follows: the rubber set time was 3 seconds, and the tensile shear bond strength was 145 k.
gf/cd (steel), forced deterioration test 50 days, rubber set time is 3 seconds, tensile shear adhesive strength is 14 D kgf
/crll (steel).

Further, even after 50 days of the forced deterioration test, no odor or irritating odor was observed. Furthermore, the whitening phenomenon was also comparable to that of the adhesives of Examples 1 to 4.

Example 10 and Comparative Examples 3 to 7

Claims (1)

[Claims] 1. A general formula with a cyanoacetate content of 5% by weight or less, an alcohol content of 5% by weight or less, and a water content of 0.02 to 0.2% by weight ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, R is an alkylene group with 2 to 4 carbon atoms, and R' is an alkyl group with 1 to 6 carbon atoms) or 2-cyanoacrylate and anion shown by ▲There are mathematical formulas, chemical formulas, tables, etc. An adhesive composition comprising a polymerization inhibitor.