JPS6050202B2 - Anaerobic curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved anaerobic curable composition, which provides an anaerobic curable composition having an improved fracture torque strength/escape torque strength ratio.

Anaerobic curing means that no change occurs while in contact with air (or oxygen), but polymerization occurs rapidly when applied to the threads of bolts and nuts and tightened, etc., when oxygen is excluded. This refers to the property of starting and curing in a short period of time.

Due to its unique polymerization initiation mechanism, anaerobic curable compositions are known for their use in preventing loosening of threaded parts, fixing of fitting parts, sealing of various joint parts, etc., and the demand for them has been increasing recently.

The anaerobic curable composition is required to have stability until it is used, that is, stability at room temperature in the atmosphere or in the presence of oxygen for a long period of one year or more.

Furthermore, during use, a high curing speed is required. Generally, in order to improve the stability of anaerobic curable compositions, a well-ventilated polyethylene container is used for storage, and the content is set to 112 degrees with a space at the top, so that the oxygen present in that space is Care has been taken to ensure continuous contact.

The most important application utilizing the properties of anaerobic curable compositions is the prevention of loosening of screw parts used in the assembly of mechanical parts, electrical parts, etc.

In screws and parts, loosening occurs due to relative movement between parts due to vibration, impact, etc., but in order to most effectively prevent this, use an anaerobic curing composition with high breaking torque strength. It is necessary. Here, the breaking torque refers to the torque required for the screw to start moving for the first time when a torque is applied to return it to a stuck threaded part, and the breakout torque refers to the torque required for the first
This refers to the average value of torque required for rotation. That is, the breaking torque is necessary to prevent the initial loosening of the threaded part, and the escape torque is the torque that influences the subsequent loosening and falling off of the threaded part. When fixing items that are not repeatedly assembled and disassembled, it is sufficient to prevent initial loosening, and a high release torque is sufficient, but it is sufficient to prevent the initial loosening, but it is sufficient to have a high escape torque. For this purpose, compositions with high breaking torque strength and low escape torque are suitable.

This is expressed as a breaking torque/escape torque ratio of 1 or more, preferably about 1 to 5. If an attempt is made to increase the breaking torque strength of an anaerobically curable composition, the escape torque strength also tends to increase, and as a result of using such a composition, disassembly of the threaded portion may become extremely difficult or impossible, or machine screws may Sometimes it broke.

Furthermore, because the escape torque strength was weakened, the breaking torque strength also decreased, and as a result, there were cases where threads became loose. As described above, it has been extremely difficult to balance the breaking torque strength and escape torque strength provided by the anaerobic curable composition. The present inventors conducted various studies to provide an anaerobic curable composition exhibiting high breaking torque strength and having a ratio of breaking torque strength/escape torque strength of 1 or more, and found that castor oil, polycaprolactone, and polyoxytetramethylene glycol They have discovered that the objective can be achieved by incorporating into the composition one or more components selected from the following.

A polyester plasticizer is added to the anaerobic curable composition. It is already known that the torque ratio can be improved by combining the torque ratio (for example, Japanese Unexamined Patent Publication No. 48-2623).

However, in this case, as is clear from the description, the main objective is to make the ratio of breaking torque/main torque 1 or more, and to improve the breaking torque strength. In that respect, it was still insufficient. In addition, the blending ratio of the polyester plasticizer in this known example is about 10 to about 30%, and there are examples where the blending ratio is 20%, but using a large amount of saturated polyester plasticizer The anaerobic curable composition has an adverse effect on secondary physical properties such as durability, solvent resistance, heat resistance, and impact resistance of the cured product. The polymerizable (meth)acrylate monomer that can be used in the present invention may be any radically polymerizable (meth)acrylate.

Representative examples include (4) to (G) shown below. Note that (meth)acrylate in this specification means acrylate and/or methacrylate. (4) Polyester poly(meth)acrylate;
It is a compound represented by the following general formula, and its details can be found in JP-A-49-12088? It is as explained as 1 [1] Polyester polyacrylate and/or polyester polymethacrylate from the lower left on page 2 of the publication to the upper left on page 4. However, the meanings of the symbols are as follows.

M: acrylic acid or methacrylic acid residue G; glycol residue Tr; triol residue Te; tetraol residue D1: 2-basic acid residue D2; 3-basic acid residue D4; 4-basic acid residue n; 1 or more Integer number (B) polyol poly(meth)acrylate; This is a compound represented by the following general formula, the details of which are disclosed in JP-A-49
It is as explained as 1 [■] Polyhydric alcohol polyacrylate and/or polyhydric alcohol polymethacrylate from the lower left of the upper row to the lower right of the upper row of page 4 of Kansai No. 1208.

However, the meanings of the symbols are as above.

(C) Epoxy poly(meth)acrylate; this has a structure in which at least two acryloyloxy groups and/or methacryloyloxy groups and a hydroxyl group are present in the molecule.

The details are as described in JP-A No. 49-12088 from the upper right corner of page 4 to the lower left corner of page 5 as 1 [■] Epoxy acrylate and/or epoxy methacrylate. (D) Polyurethane (meth)acrylate: A compound represented by the following general formula, details of which can be found in Japanese Patent Publication No. 45-124 (1)
It is as described from the lower right of page 1 to the lower right of page 3 of the publication. However, R″: hydrogen or methyl group R″″; divalent organic group x selected from the group consisting of lower alkylene, phenylene, and naphthylene groups having 1 to 8 carbon atoms; TR is selected from hydrogen and a group having a lower alkyl group having 1 to 7 carbon atoms.

B; a polyvalent organic group selected from the group having substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, aralkyl, alkanyl and heterocyclic groups n
; An integer of 2 to 6 () A reaction product of acrylic acid or methacrylic acid with a monoepoxide and an acid anhydride; This is represented by the following general formula, and its details are given in JP-A-50-9686. It is as explained as a reaction product of r(3) acrylic acid or methacrylic acid and a monoepoxide and an acid anhydride from the bottom right corner of page 4 to the top right corner of page 5.

However, M; acrylic acid or methacrylic acid residue G; glycol residue based on monoepoxide D; dibasic acid residue based on acid anhydride n; integer greater than or equal to 1? ) has a carboxyl group in the molecule and has a boiling point of 25 at normal pressure.
Mono(meth)acrylate of 0°C or higher; details of this can be found in JP-A No. 50-9686, from page 5, bottom left, to page 6, top right. It is as explained as a monoacrylate and/or monomethacrylate at 250°C or higher.

3) Poly(meth)acrylate of addition alcohol of phenol compound and oxide compound; This is a compound represented by the following general formula, and the details are described from the upper left corner to the lower left corner of page 2 of JP-A-49-12255 Ginko. It is as it is.

However, the aromatic group in the above formula is a benzene ring or other aromatic group with or without a substituent, R1 and R2 are hydrogen, alkyl, aryl group, or halogen atom, and R3 is hydrogen or methyl. group, R4 and R5 are hydrogen, alkyl, alkoxy groups or halogen atoms, n is 1 to 20
is an integer.

In the above, seven representative polymerizable (meth)acrylate monomers from (4) to (G) were explained,
Many of these products are manufactured not as single compounds but as mixtures of various compounds, and are generally used as such mixtures, and when displaying names and structural formulas, the type and preparation of synthetic raw materials are used. It is customary to display based on theoretically assumed compounds assumed from molar ratios and chemical reactions.

The polymerizable (meth)acrylate monomer used in the present invention also follows this general practice. The polymerizable (meth)acrylate monomers (4) to (G) can be used alone or in combination of two or more as components of the anaerobic curable composition, but the following compounds can also be used depending on the purpose. It can be blended with

(1) (Meth)acrylate represented by the general formula M-G-0H (MG has the same meaning as above) Compounds corresponding to this include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl ( Examples include meth)acrylate.

1 (2) General formula CH2. ---C? (meth)acrylate represented by 9-[F]R2, where R1: hydrogen or methyl group R2: hydrogen or an alkyl group having 1 to 8 carbon atoms, (3) nitrogen-containing (meth)acrylate such as diacetone (meth)acrylamide, Examples include dimethylaminoethyl (meth)acrylate and dimethylaminopropyl (meth)acrylate.

(4) Alkoxypolyalkylene glycol (meth)acrylate general formula M-G-0R (the meanings of M..G are the same as above).

R is an alkyl group having 1 to 3 carbon atoms), and typical examples thereof include methoxydiethylene glycol (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, and the like.
The compounds (1) to (4) above can be blended in any ratio to the polymerizable (meth)acrylate monomers (4) to (G), but the preferred blending ratio is 1 to 7.
It is in the range of 0 Wt%. These polymerizable (meth)acrylate monomers generally contain a polymerization inhibitor added during production or storage, but usually 30%
If it is about 0 ppm or less, it can be used as is to prepare an anaerobic curable composition.

Next, the organic hydroperoxide that can polymerize the above monomer in the absence of oxygen will be explained. The general formula is R-
It is represented by 00H. However, R: a hydrocarbon group having up to about 18 carbon atoms, preferably an alkyl group, allyl group, or aralkyl group having 4 to 12 carbon atoms.

In general, R may contain any substituent or constitute a cyclic group, and may be other than a hydrocarbon, but
Anything that does not have an adverse effect on the purpose of the present invention can be used.

Typical examples include t-butyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, 2●5-dimethylhexane-2.
Examples include organic hydroperoxides such as 5-dihydroperoxide.

It is possible to blend not only one type of organic hydroperoxide but also a combination of two or more types.

The amount can be used in a range of about 20% or less, but preferably in a range of 0.1 to 5 wt%. Excessive use of hydroperoxide adversely affects the stability, adhesion strength, durability, etc. of the anaerobic curable composition. It is also possible to add dialkyl peroxide, ketone peroxide, diacyl peroxide, peroxy esters, etc. to the hydroperoxide within a range that does not impair the features of the present invention. Next, the blended components that make it possible to improve the breaking torque strength and achieve a breaking torque strength/breakdown torque strength ratio of 1 or more will be explained in order.

(1) Castor oil is a non-drying fatty oil whose main component is ricinoleic acid ester of glycerin.

*HO-+. CH2CH2CH
2CH2-0+NCH2CH2CH2C In the present invention, those having an average molecular weight of about 800 to about 2000 are preferred. For example, PTG-1001 manufactured by Nippon Polyurethane Industry Co., Ltd.
20013001400150 Maki is mentioned. The above-mentioned ingredients (1) to (Iiii) are polymerizable (meth)
It can be used within a range that is soluble in acrylate monomers and organic hydroperoxides, but preferably 40%
% or less (weight % based on the total composition), and even a proportion of 10% or less can sufficiently improve the breaking torque strength.

Unnecessary excessive blending may lead to poor solubility or adversely affect the stability, durability, etc. of the anaerobic composition. Ingredients (1) to (111) can be used regardless of the polymerizable (meth)acrylate monomer, but
Depending on the type, the breaking torque can be improved, and the breaking torque strength/
There are slight differences in the balance of escape torque strength, solubility, etc. For example, in the case of castor oil, the polyester poly(
Preferred ingredients include meth)acrylate and epoxy poly(meth)acrylate shown in (C).

A curing accelerator is usually used in anaerobic curable compositions, but
All conventionally known accelerators can be used.

Representative examples include organic sulfimides such as 0-benzsulfimide, N-N-dimethylaniline, N-
N◆N-dialkylarylani(Ii) polycaprolactone such as N-dimethyl-p-toluidine is relatively easily obtained by a ring-opening addition reaction of ε-caprolactone using a polyol as an initiator. The polymer has a narrow molecular weight distribution, low acid value, low water content, and low hue.

Typical examples include polycaprolactone diol and polycaprolactone triol, and in the present invention, those having an average molecular weight of about 300 to 10(1) are suitable. For example, polycaprolactone T-3001T-3 manufactured by Chisso Corporation
10, etc. (Ii) Polyoxytetramethylene glycol Polyoxytetramethylene glycol is a ring-opened polymer of tetrahydrofuran and is represented by the following general formula.

Examples include 0H phosphorus, heterocyclic secondary amines such as 1,2,3,4-tetrahydroquinoline, 1◆1-dialkylhydrazine and/or salts thereof, and the like.

A suitable blending ratio of these accelerators is 0.1 to 5 wt%. The following substances can also be added to the anaerobic curable composition to further increase its value.

(a) Stabilizer for maintaining long-term storage stability.

Examples include chelating agents such as ethylenediaminetetraacetic acid tetrasodium salt, oxalic acid, and quinones such as 1,4-naphthoquinone. (b) Dyes and pigments when coloring is required.

(c) Soluble polymer for thickening. Next, in order to illustrate the present invention more specifically, Examples and Comparative Examples will be given and explained below.

Note that the present invention is not limited only to this example. Example 1 and Comparative Example 1 Polyester polymethacrylate or diethylene glycol dimethacrylate is blended with polycaprolactone or polyoxytetramethylene glycol, and if necessary, heated to 40 to 60°C to dissolve it,
Next, a catalyst was blended and dissolved with stirring to obtain an anaerobic curable composition having the composition shown in Table 1. In addition, the main ingredient is in parts by weight.
Further, the catalyst (including the curing accelerator) is expressed in weight percent relative to the main ingredient. The same applies to each example below. This anaerobic curable composition was previously degreased with trichlorethylene.
F? Apply a few drops to the threads of 3/8" iron bolts and nuts, assemble the bolts and nuts with an initial tightening torque of 0, and after leaving them at room temperature for two hours, use a torque wrench to measure the breaking torque strength and escape torque strength (1/ The average value of torque strength at 4, 2/4, 3/4, and 4/4 rotations was measured.

The results were as shown in Table 1. Example 2 and Comparative Example 2 Anaerobic curable compositions were prepared in the same manner as in Example 1, and the torque strength was measured.

In addition, both compositions contain 1.0% of cumene hydroperoxide and 0.0% of 0-benzsulfimide as catalysts.
3% and 0.5% N-N-dimethylaniline were added.
The composition and torque strength of the composition were as shown in Table 2. Example 3 In the same manner as in Example 1, an anaerobic curable composition was prepared as shown in Table 3, and the torque strength was measured.

This composition has a higher viscosity than the compositions of the above examples. *1
Same as Example 1 *2 NK-Ester M-4G manufactured by Shin-Nakamura Chemical Industry Co., Ltd. *
3 Nippon Pure Chemical Industries, Ltd. Aron S-1005 Example 4 No. 3 in Example 3 Regarding the anaerobic curable composition No. 12, the breaking torque strength and escape torque strength were measured in the same manner as in Example 1 using bolts and nuts (MIOJIS class 2 screws) made of various materials.

The results are shown in Table 4. When a polymerization inhibitor, an ultraviolet absorber, a dye, etc. were added to the anaerobic curable compositions of the above examples, all of them had long-term storage stability.
A composition with high commercial value could be obtained.

Claims (1)

[Scope of Claims] 1. Polymerizable (meth)acrylate monomers, organic hydroperoxides, and the following (1) to (3) soluble therein:
) An anaerobic curable composition comprising at least one component selected from: (1) Castor oil. (2) Polycaprolactone. (3) Polyoxytetramethylene glycol.