NO742987L - - Google Patents

Description

HERD BAR COMPOSITION.

The present invention relates to an anaerobic, hardenable sealing composition, which has the property that it is in a liquid state, but that it instantly hardens under conditions that involve the exclusion of air at room temperature, and whereby a seal or adhesion of cracks is obtained between adjacent surfaces, and especially of very small cracks between adjacent metallic surfaces.

The expression "an anaerobic, hardenable sealing property", and which is used in the present description, is intended to include a property of the composition, which expresses that it retains a liquid state in air or oxygen, while obtaining an immediate

In polymer reaction and curing by exclusion of air or oxygen.

Anaerobic curable compositions have previously been proposed in U.S. Pat. Patents Nos. 2,628,178, 2,895,950, 3,041,322, 3,043,820, 3,046,262, 3,218,305, 3,300,547, 3,435,012, and 3,457,212, and Japanese Patent Nos. 39-11057, 43- 10855, 44-852, 44-7541, 44-16547, 44-16548, 45-33664, 45-33665, 46-3382 and 46^31680.

Of the above-mentioned patents, in particular, U.S. patent no. 3,218,305 and the Japanese patents no. 39-11057, 43-6545, 44-16547 and 44-16548 anaerobic, curable compositions, which are characterized by high speed during curing. These compositions, which are prepared by adding polyamino compound to poly- or mono-acrylate ester monomers which polymerize, and which contain a catalyst to produce anaerobic

curing properties by mixing poly- or mono-acrylate ester monomers with sulfimide and certain amines, or obtained by

adding metallic salt to the poly- or mono-acrylate ester monomers, all polymerize to thereby be cured to an extent that only temporarily seals after a curing time of more than 30 minutes at room temperature, after which a perfect seal is obtained approx. 5 hours later.. Even if the curing speed was somewhat accelerated, these compositions are all different from the composition where you get an immediate cure.

The purpose of the present invention is to provide a new composition which hardens under the exclusion of air.

The composition according to the present invention hardens only after 30 seconds at room temperature and in cracks between nearby.

surfaces, after which after approx. 5 minutes get a perfect attachment or seal. When the composition according to the present invention is used e.g. with partial contact between bolt and nut or on part of the contact between the inner surface of a cylinder and the outer surface of a cylinder by crimp fit or press fit, or applied to a contact part between adjacent smooth surfaces of e.g. metal, glass, ceramics, plastic etc, i.e. two surfaces that are in close proximity

IN

Jcontact with each other, then air will automatically be pushed out from part of the contact surface, whereby hardening is achieved only after 30 seconds at room temperature to such an extent that the attached or sealed part cannot be removed by normal external force, and after which obtains perfect curing after about 5 minutes to an extent which results in an object where adhesion and sealing are complete.

Other purposes and advantages of the present invention will i

the following be obvious.

The composition according to the present invention is an anaerobic curable sealing composition, which hardens instantly, and which consists of polymeric monomers with the following general formula

(IN):

where is selected from the group consisting of hydrogen, chlorine, methyl and ethyl; but when y is 0, R 1 is selected from the group consisting of hydrogen and methyl; •R2 is selected from the group consisting of hydrogen, and the group with the following general formula (II):

but when y means 0 is hydrogen;

R3 is selected from the group consisting of hydrogen, methyl, ethyl, -CH2OH,, and the radical with the following formula.

(III) : '

R. is selected from the group consisting of hydrogen, hydroxy and the radical with the above-mentioned general formula (III);

p and y mean either zero or one;

m means an integer from 1-8; but when y means

0 means m an integer from 2-8;

n means an integer from 1-20; but when y means 0, n is an integer from 1 - 10;

as well as 0.01 to 10% by weight of organic peroxide, and a mixture of 0.01

- 10% by weight of mercaptancarboxylic acid with the following general formula (IV):

where R^ is selected from the group consisting of hydrogen °9<C>n<H>2n'

R 2 is selected from the group consisting of hydrogen and<C>n<H>2n<?>. or its esters as well as 0.05 to 5% by weight organic amine.

When the composition, which should consist of polymeric monomers of the general formula (I), such as diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate and trimethylolpropane dimethacrylate, etc., all of which contain 60 ppm. hydroquinone as well as polymerization initiator, such as cumene hydroperoxide, is applied to part of the contact surface between bolt and nut, then anaerobic hardening occurs little by little, usually after 10 hours. Even if organic amine, which is well known as a polymerization promoter, is added, the polymerization rate can be reduced by only 10-20%.

According to the invention, it has been found that the anaerobic curing rate on part of the contact surface between bolt and nut can be accelerated to such an extent that immediate curing occurs by adding mercaptancarboxylic acid of the general formula (IV) or its esters and organic amine to the composition, which consists of polymer monomers with the general formula (I) and polymerization initiator. The mechanism is not yet known. Mercaptan carboxylic acid is used as a redox polymerization catalyst, whereby mercaptan carboxylic acid has similar properties as organic peroxide.

However, when mercaptan carboxylic acid with the general formula

(IV) is used as polymerization initiator for a polymer monomer with the general formula (I), then the effect is very weak and lacks practical significance compared to the case where organic peroxide is used. Organic peroxide is superior to polymer monomers of the general formula (I) in terms of effect as far as the polymerization initiator is concerned. Here is

it is also an interesting fact that small amounts of mercaptan carboxylic acid of the general formula (IV) or its esters, which are added to the polymer monomer of the general formula (I), and which contain a suitable amount of organic peroxide, serve as the strong polymerization - the promoter which causes an anaerobic curing speed acceleration to such an extent that you get instant curing. On the other hand, however, the storage stability of said polymer monomer is markedly impaired, and then to such an extent that said polymer monomer does not find practical use. By taking these advantages and disadvantages into account, a product has been obtained which is storage-stable for several months by using organic amine.

As a method to further increase the storage stability, it is proposed to mix mercaptancarboxylic acid and its esters with the composition of polymer monomers with the general formula

(I), which contains organic peroxide, as well as organic amine, just for use. With such a binary system, it is possible to increase the storage stability from one to two years. Needless to say, this binary system cannot be incorporated

in the concept of the so-called two-fluid system, which consists of the main agent and the binder, and which make up adhesives, such as epoxy resin.

In Apart from such binary system, however, it is more common

in certain cases to achieve sufficient storage stability by adding 0.001 to 0.1% by weight of a polymerization inhibitor for vinyl compounds, such as benzoquinone, paramethoxyphenol,

etc, to the anaerobic curable sealing composition according to the present invention.

The anaerobic curable sealant composition can be achieved

by mixing, the aforementioned components at room temperature, but in cases where there is a time difference in the addition of each of the components, it is desirable to add the polymer monomer of the general formula (I), which contains an appropriate amount of organic peroxide, first organic amine, then mercaptancarboxylic acid of the general formula (IV) or its esters, and then mix and finally prepare a mixture in which each component is evenly distributed. As a closed container for layer-

ring of said manufactured composition is suitable plastic, such as polyethylene, and furthermore it is necessary to have space

for remaining air in the container. Furthermore, during storage, if desired, it is possible to color said container or make it opaque in order to thereby protect it from the sun, and furthermore it is desirable to keep the container in a cool place.

Polymer monomers, which are used according to the present invention,

are substances of the above general formula, and include monoacrylate or monomethacrylate of ethylene glycol, 1,2-propylene glycol and 1,4-butylene glycol, such as 2-hydroxyethyl methacrylate, monoacrylate or monomethacrylate of poly-1,2-propylene glycol with a degree of polymerization of 2 - 4, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate

acrylate, tetraethylene glycol dimethacrylate, 1,2-propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, polyethylene glycol dimethacrylate, di(pentamethylene glycol) dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol di(chloroacrylate), diglycerol diacrylate, glycerol trimethacrylate, trimethylol trimethacrylate, trimethylol propane trimethacrylate, and the like, and their mixtures.

Organic peroxides, which are used according to the present invention, include diacyl peroxides, ketone peroxides, hydroperoxides, and the preferred polymerization initiators are hydroperoxides, and especially cumene hydroperoxides and tertiary butyl hydroperoxides. The added amount of said hydroperoxides which are suitable according to the present invention is in the range from 0.01 to 10% by weight, calculated on the weight of the polymer monomer with the above formula, and then preferably in the range of 0.2

to 5% by weight. The added amount that exceeds 10% by weight is undesirable according to the present invention, as the storage stability of said compositions is hindered, and the added amount of less than 0.01% by weight is undesirable according to the present invention as the conductivity is reduced.

Mercaptan carboxylic acid or its esters, and which are used according to the present invention include thioglycols, |3-mercaptopropionic acid, oc-mercaptopropionic acid, thioglycol-methyl, thioglycol-ethyl, etc.

The added amount of said mercaptan carboxylic acid or its esters, which are suitable according to the present invention, is in the range of 0.01 to 10% by weight, calculated on the weight of said polymer monomer, and preferably in the range of 0.2 to 5, 0% by weight. The added amount that exceeds 10.0% by weight is undesirable according to the present invention as the storage stability is reduced. Despite the fact that there is no clear cause, it is assumed

that this reduction takes place due to decomposition and activation of the polymerization catalyst.

Organic amines, which serve as an important part in the stabilization of mercaptancarboxylic acid or its esters, which are used according to the present invention, include triethylamine, diethylamine, ethylhexylamine, 1,2,3,4-tetrahydroquinoline, dimethylaniline, pyrrolidine, butyrolactam, methylbenzylmethylamine, etc. The suitable amount of addition is from 0.05 to 5% by weight, calculated on the weight of said polymer monomer, and the ratio is 1/10 - 4/10, calculated on mercaptancarboxylic acid or its esters.

The characteristics of the aforementioned composition, which are shown in the examples below, were determined as follows: j (1) Hardening rate, fixation initiation time, i.e. the time at which a bolt became largely immovable in the forward and backward direction or until right and left; fixation time,

i.e. the time at which the fixed part became immovable without the use of tools; and the perfect setting time, i.e., the time at which the return torque cannot increase when left to itself, was determined by using a grease-removed iron bolt measuring 3/8" diameter and a nut of 7, 5 mm thickness, as well as coat: the threads of said iron bolt and nut with the composition to be measured, and then tighten, said iron bolt with iron nut at the torque zero, and let the test object stand at 25°C.

(2) The return torque was determined by measuring the torque during return rotation and then loosening after leaving the sample according to the above (1) as it is at 25°C

for 24 hours.

(3) Storage stability, i.e. the time until the sample loses

fluidity, whereby the sample is kept at 80°C + 1°C in a polyethylene container. was determined, and this sample was considered as a criterion for gelation time and stability, as it was not possible to determine the storage stability due to the long time that this trial would require. If the gelation time at 80°C is over 10 hours, the object can be stored for more than 3 months at room temperature around 20°C.

The following examples of different embodiments shall further illustrate the invention.

In EXAMPLE 1

The anaerobic curable compositions are prepared by adding 3% by weight of cumene hydroperoxide and 0.6% by weight of 2-ethylhexylamine and an additional 3% by weight of thioglycolic acid to 100 parts by weight of each of the polymer monomers shown in Table 1, containing 60 ppm hydroquinone. One produces respectively

6 test objects by coating the obtained compositions on the threads of each of the degreased iron bolts, which have a diameter of 19 mm, and after which the iron bolt is tightened with an iron nut with a thickness of 7.5 mm and at a torque of zero. The whole is then allowed to stand at 25°C, and the curing rate was determined using the above-mentioned method. The return torque and storage stability were determined using the above-mentioned method, and average values were calculated. The results are shown in Table 1.

{ As is clearly evident from these data, the composition containing a mixture of thioglycolic acid and 2-ethylhexylamine as a polymerization promoter begins to set under betin- . the geyser consisting of air exclusion and at normal temperature after approx. 30 seconds to 2 minutes, after which the fixation after approx. one minute had taken place to such an extent that a fixed part could not be removed without the use of a tool. Moreover, the adhesion ability of said composition after 24 hours is far better than that obtained with a composition of the usual type, and the shelf-life stability is excellent.

EXAMPLE 2

The anaerobic curable compositions were prepared by adding 0.5% by weight of 2-ethylhexylamine and 3% by weight of thioglycolic acid and an additional 3% by weight of each of the polymerization initiators (organic peroxide) shown in Table 2,

to 100 parts by weight of trimethylolpropane trimethacrylate containing 60 ppm hydroquinone. By using each of the compositions obtained, curing speed, return torque and durability stability were determined in more or less the same way as in example 1. The results appear in table 2.

As can be seen from these data, most organic peroxides are effective as polymerization initiators. However, since the characteristic features of said anaerobes, . curable compositions according to the present invention are instantaneous curing, then the most preferred polymerization initiator is believed to be hydroperoxides according to table 2. . EXAMPLE 3

The anaerobic curable compositions are prepared by adding cumene hydroperoxides (polymerization initiator) in various amounts, as shown in Table 3, and; 0.6% by weight 2-ethylhexylamine and 3% by weight thioglycolic acid to 100 parts by weight trimethylpropane trimethacrylate containing 60 ppm . hydroquinone. For each of the compositions obtained, curing speed, return torque and durability stability were determined in more or less the same way as in example 1. The results are shown in table 3.

As can be seen from these data, when no polymer initiator is added, satisfactory curing is not obtained, and durability s-stability is markedly unstable, while when a smaller amount of polymer initiator is added, e.g. in the quantity ratio of 0.01% by weight and 10% by weight, one obtains preferred curing speed, adhesion force and durability-stability. As can also be seen from these data, when the amount of addition exceeds 10% by weight, the shelf-life stability will become unstable,

and furthermore the curing speed will be affected.

EXAMPLE 4

The following compositions were produced:

(a) The composition prepared by adding 3% by weight of tertiary butyl hydroperoxide to 100 parts by weight;• (b) The composition prepared by adding 0.6

% by weight 2-ethylhexylamine to said composition (a);

(c) The composition prepared by the addition of 3

% by weight thioglycol to said composition (a); and

(d) The composition which is prepared by adding 3% by weight of thioglycolic acid to said composition (b).

By using these compositions, the curing speed, return torque and durability stability were determined in more or less the same way as in example 1. The results appear in table 4.

As can be seen from these data, the composition (a) has

in

even if this is produced by adding only polymerisation

1I — ion catalyst good durability stability, the curing rate is markedly low, and the adhesion force is insufficient, and the composition is thus not practically applicable. With the composition (b), which is prepared by adding 2-ethylhexylamine to said (a), one has an ok curing speed, and the adhesion force is also somewhat ok. However, the composition is still insufficient. Furthermore, with the composition (c), which is prepared by adding thioglycolic acid to said composition (a), in contrast to the composition (b), the curing speed is markedly fast, the adhesion property is excellent, but the shelf-life stability is lacking. Thus, the composition is not practically applicable.

"" On the other hand, the composition (d), which is prepared by adding 2-ethylhexylamine and thioglycolic acid, has good shelf-life stability and, moreover, excellent adhesion power, and curing takes place instantaneously. When the composition according to the present invention is used e.g. on a part of the contact surface between bolt and nut, and when air is excluded at normal

•temperature, then fixation begins after 30 seconds, and fixation continues until the adhered part cannot be removed using tools. EXAMPLE 5 The compositions are prepared by adding each 3% by weight different mercaptan carboxylic acids or its esters, which are shown in Table 5, to each of the mixtures, which were prepared by adding 3% by weight of cumene hydroperoxide and 0.6% by weight of 1,2,3,4-tetrahydroquinoline to 100 parts by weight of trimethylolpropane trimethacrylate, containing 60 ppm of hydroquinone. When using the compositions obtained, the curing speed, return torque and durability stability were determined in largely the same way as in example 1. The results appear in table 5.

[as these data show, when various mercaptan carboxylic acids or their esters are used according to the present invention, in the presence of amine, good shelf life stability is obtained, and the initiation time for fixation is 15 seconds at the fastest and approx. 2 minutes at the slowest.

EXAMPLE 6

The compositions are individually prepared by mixing

each of the compounds prepared by adding 0.6% by weight of each of the various organic amines shown in Table 4 to 3% thioglycolic acid with a compound prepared by adding 3% by weight cumene hydroperoxide to 100 parts by weight of trimethylolpropane methacrylate. By applying

of the compositions obtained, curing speed, • return torque and durability stability were determined in more or less the same way as in example 1. The results are shown in table 6.

As can be seen from the data, when different organic amines and thioglycolic acid were used simultaneously, there was a markedly rapid cure rate for each of the compositions, and each individual composition showed excellent adhesion strength and shelf life stability.

EXAMPLE 7

The compositions were prepared by adding 3 parts by weight of cumene hydroperoxide and 0.6 parts by weight of 2-ethylhexylamine to 100 parts by weight of trimethylolpropane trimethacrylate containing 60 ppm hydroquinone, and then adding thioglycolic acid in the parts by weight shown in Table 7. By using the obtained compositions determined one cure rate, return torque and durability stability in basically the same way as in example 1. The results appear in table 7.

As these data show, when the amount of thioglycolic acid added is small, the curing rate is reduced, and when thioglycolic acid is not added, signs of curing are obtained after 9-10 hours, after which the curing progresses markedly slowly. On the other hand, when the addition quantity of thioglycolic acid is large, a markedly fast curing speed is obtained, but the durability stability is lost to such an extent that the composition has not found practical use. The suitable addition amount of thioglycolic acid, whereby the adhesion ability and durability stability are excellent, and whereby rapid curing is obtained, is from 0.01 to 10.0% by weight, and preferably from 0.1 to 0.5% by weight -%.

EXAMPLE 8

The compositions are prepared by adding 3% by weight of cumene hydroperoxide to 100 parts by weight of trimethylolpropane trimethacrylate, containing 60 ppm. hydroquinone, and then addition of the compositions which were prepared by the respective additions of 2-ethylhexylamine in the parts by weight shown in Table 8, to 3% by weight of thioglycolic acid.

By using the compositions obtained, the curing speed, return twisting moment and durability stability are determined largely in the same way as in example 1. The results are shown in table 8.

! As can be seen from these data, when the 2-ethylhexylamine is not added, shelf-life stability is lost, and when the addition amounts are large, excellent shelf-life stability is obtained, however, when the addition amount is more than 5% by weight, this has a detrimental effect on shelf-life the stability.

The suitable addition amount of 2-ethylhexylamine is from 0.01

to 5.0% by weight, taking into account the balance between stability and curing speed, whereby one prefers addition amounts in the range of 1/10 to 4/10 against 3% by weight of thioglycolic acid.

Claims (1)

An anaerobic, curable sealing composition that cures instantly, characterized in that it consists of polymer monomers with the following general formula (I): wherein R 1 is selected from the group consisting of hydrogen, chlorine, methyl and ethyl; but when y means 0, R^ is selected from the group consisting of hydrogen and methyl; R^ is selected from the group consisting of hydrogen and the group with the following general formula (II): but when y means 0, R 2 means hydrogen; R 3 is selected from the group consisting of hydrogen, is selected from the group consisting of hydrogen, hydroxy and the radical according to the general above formula (III); p and y mean either 0 or 1; n means an integer from 1 - 8; but when y means 0, m means an integer from 2 - 85 n means an integer from 1-20; but when y means 0 means n an integer from 1 - 10, and 0.01 to 10% by weight organic peroxide, and mixture of 0.01 to 10% by weight mercaptan carboxylic acids with the following general formula (IV): where R 1 is selected from the group consisting of hydrogen and CH, : * n 2n' R 2 is selected from the group consisting of hydrogen and <C> n <H> 2n, or its esters as well as 0.05 to 5% by weight of organic amine.