JPS6112703A - Multifunctional acrylate composition and stabilization against early anaerobic polymerization - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides polymerizable compositions stabilized against premature polymerization, methods of stabilizing these compositions as described above, and polymerizable compositions stabilized against premature polymerization. This relates to the use of the composition.

Ethylenically unsaturated compounds, such as esters of acrylic acid and methacrylic acid, readily polymerize to form polymers useful for many purposes. It is well known that such polymerization usually proceeds by a free radical mechanism. This mechanism is typically initiated by means such as the use of chemical initiators or exposure of the unsaturated compound to ultraviolet or electron beams.

It is often desirable to initiate the polymerization under anaerobic conditions, ie, in the absence of air.

But under these conditions, the main inhibitor
Polymerization often occurs spontaneously because oxygen, which is a chemical, exists only in extremely low concentrations, if any at all.

When controlled anaerobic polymerization is desired, the monomer composition is exposed to air (i.e., under aerobic conditions).
It may be stabilized against premature polymerization by storage, sometimes also in the presence of a co-inhibitor such as p-methoxyphenol.

However, under certain circumstances it is important to at least temporarily inhibit polymerization when the monomer is in an anaerobic atmosphere. One example of such a situation is when a capacitor dielectric is formed by vacuum deposition of a monomer composition followed by radiation (ie, electron beam)-initiated polymerization.

Co-pending application No. 56, all similarly filed.
No. 2.779, No. 562.871, No. 562°872
No. 562,873, No. 562.1393 and No. 562.894 (all filed December 1, 1983).
9th) and No. 560A-55943. These applications describe various multifunctional acrylate monomer systems useful in making polymeric dielectrics for capacitors such as those described above, these polymers useful as dielectrics, and vacuum deposition and electron beam polymerization of dielectric production. Contains legal details. The disclosures of all of the applications cited above are incorporated herein by reference.

The method of manufacturing such capacitors requires that the monomer sticking be completed before polymerization occurs. Because such deposition occurs in an anaerobic system, and even the presence of a co-inhibitor under these conditions is not a sufficient inhibiting condition, the vacuum system used must be used to prevent premature polymerization. However, it is extremely important to create conditions that allow radiation-initiated polymerization to occur at the same time as desired.

It is therefore a principal object of the present invention to provide a method for stabilizing monomeric polyfunctional acrylate systems against premature anaerobic polymerization.

It is also an object to provide a multifunctional acrylate composition stabilized in this way.

Yet another object is to provide a method in which a monomeric multifunctional acrylate can be stabilized against anaerobic polymerization until it is deposited on an electrode surface and then polymerized to form a dielectric layer.

Some of the other objectives will be self-evident or will be apparent from the description below.

In its broadest aspect, the present invention relates to compositions stabilized against anaerobic polymerization and methods of so stabilizing. The composition of the present invention comprises at least one of the following polyfunctional acrylates.

However, in the formula, Bl is an aliphatic or alicyclic group containing at least 10 carbon atoms, R2 is hydrogen or a hydrocarbon group containing 1 to 5 carbon atoms, and n
is 2-6.

(B) at least one substantially stable free radical having the formula (2) of Appendix Table 1 in an amount that inhibits anaerobic polymerization in small amounts;

However, in the formula, each R3 is independently a tertiary lower alkyl group, CH or N.

Component A in the composition of the present invention is, as described above, at least one polyfunctional acrylate having the formula I (hereinafter, the formula in the appendix will be abbreviated as "Formula I in the appendix"). (It is often written as "Equation 1"). In this formula, the group R1 is an aliphatic or cycloaliphatic group containing at least 10 carbon atoms. This may be a hydrocarbon group or a substituted hydrocarbon group; in the latter case the types of permissible substituents will be clear to those skilled in the art. Substituents that generally have a small effect on the electrical properties of the molecule are mentioned, such as hydroxy, alkoxy, carbalkoxy and nitrile substituents. However, most often the group R1 is an unsubstituted hydrocarbon group.

There is no real upper limit to the number of carbon atoms contained in this group, and Hl is a polymeric residue containing up to 500 carbon atoms, preferably up to 300 carbon atoms! It is within the scope of this invention to use compounds of

The group R1 may contain aliphatic, cycloaliphatic or aromatic residues, or a mixture of these, but all residues present in this group are aliphatic. , alicyclic, or both.

Even if the group R1 is hydrogen as mentioned above, it has 1 to 5 carbon atoms.
It may also be an alkyl group containing two or more. Dan8 is most often hydrogen or methyl, especially hydrogen.

That is, the term "acrylate" as used herein includes both acrylates and α-substituted acrylates, including methacrylates and the like. However, usually acrylates (i.e. compounds where R3 is hydrogen)
is preferred. The value of n may be between 2 and 6, most often 2 or 3.

As is clear from the above, component A generally includes acrylic acid, methacrylic acid, etc., or their acid chlorides, anhydrides, and lower alkyl esters. It can be produced by carrying out an esterification reaction with a compound. Examples of compounds of this type are polyhydroxy compounds and polyepoxides. Particularly useful polyfunctional acrylates are as follows.

α with an average chain length of 12 to 20 carbon atoms.

about 1 carbon atom as exemplified by the ω-diol mixture.
Acrylate (acrylic acid ester) of an aliphatic polyhydroxy compound containing 0 to 20 aliphatic polyhydroxy compounds.

Polymeric acrylates with groups capable of reacting with acrylic acid or its derivatives. Examples include various hydroxy-terminated diene polymers such as polybutadiene, typically having number average molecular weights of about 1.000 to 1.000 s, o
It is within the range of o o.

Acrylates of aromatic dieboquines and polyepoxides as exemplified by 2,2-bis(4-hydroxyphenyl)furopane or the diepoxy7 derivative of bisphenol AJ.

Several commercially available polyfunctional acrylates are useful in making the dielectric in the capacitors of the present invention.

These include the following, many of which are identified by trademarks such as those shown.

Bisphenol A diacrylate.

Celanese (0elanese)
rlraa) 5700 J, Bispheno-A/A
Diacrylate of diepoxide derived from. .

"Sarto? - (Sartomar) 5R-349
j, diacrylate of ethoxylated bisphenol A;

Sartomer [Ohemlnlc 2000 J, diacrylate of α,ω-alka/diols containing on average 14-15 carbon atoms.

Arco (Area) “Poly (PO17) bclJ (
This is a hydroxy-terminated butadiene resin with a number average molecular weight of about 4000) diacrylate.

Although it is within the scope of the present invention to use a single polyfunctional compound as a component, these compounds 2f! It is often preferable to use copolymers made from blends of the above. Use of such a copolymer will result in a lower dissipation factor than when using the 11 polyfunctional acrylate alone. Also, the physical properties of this material are optimized.

For example, the viscosity of the monomer composition may be reduced to facilitate its handling and deposition.

It is also within the scope of the invention to use copolymers prepared from mixtures of at least one compound of 2 and at least one monoacrylate having 2. However, in formula m, R1 is as defined already, and R4
is typically a hydrocarbon group or substituted hydrocarbon group containing about 4 to 25 carbon atoms. Examples of monoacrylates in the second category include cyclohexyl methacrylate and various acrylated derivatives of fatty acids containing substituents such as carbomethoxy or nitrile. A typical example of a copolymer of a compound of formula I and 1 is a copolymer of about 10
-50% by weight, most often about 15-35%, with the remainder being the compound of formula I.

For these commercially available acrylates and the like, it is often preferred to remove residual acrylic acid and other ionic compounds and impurities that may be present in the material obtained from the manufacturer (or supplier). Such impurities can be easily removed by known methods such as using adsorption columns or ion exchange resins.

Tables 1 and H
For example: The columns in these tables are based on capacity.

Table ■ Component Example 1 2 5 "Polyba" diacrylate 100 50
---“Chemlink 2000J
---so 1o.

Table ] Triacrylate thylate “Saltomer 5R-349J -----5020
-----------[Cellrad 3700J 5
0 -- --20 50 40 50 50 A preferred subgroup of polyfunctional acrylates is an aliphatic group in which R2 is hydrogen or methyl, n is 2 to 4, and R1 has about 10 to 40 carbon atoms. .

It is a cycloaliphatic or mixed aliphatic-cycloaliphatic group, which optionally contains up to about 3 olefinic bonds, the olefinic bonds being nonconjugated.

This preferred subgroup of R1 groups may be aliphatic, cycloaliphatic, or aliphatic-cycloaliphatic, which may optionally contain up to about 3 nonconjugated olefinic bonds.

These R1 groups contain about 10 to 40 carbon atoms.

Suitable polyhydroquine compounds include linear compounds such as hexadecanediol and octadecanediol (the hydroxy group can be located anywhere on the mirror) and branched chain isomers thereof. "Branched" means that at least one carbon atom is branched. That is, structures such as formulas ■ and V are unbranched, while structures such as formulas ■ and ■ are branched.

The preferred number of polyhydroquine compounds falling into the subgroup of
The species are branched and contain at least 18 in a single chain.
carbon atoms (that is, at least 18 carbon atoms are bonded consecutively without branching). Particularly preferred polyfunctional acrylates derived from these are those having formulas (1) and (2).

However, in these formulas, r and e are each 7 and 8, and the sum of r and day is 15. These are obtained, for example, by esterifying the hydroformylation product of oleic acid with acrylic acid as disclosed in US Pat. No. 4,244,818. Another suitable compound is 1,12-octadecanediol diacrylate, which is produced by hydrogenolysis of heptanolic acid followed by esterification.

R1 contains about 20 to 40 carbon atoms and optionally about 3
at least 1a with up to 1 non-conjugated olefinic bonds
Compounds which are aliphatic or cycloaliphatic groups of I, alone and in mixtures, usually mixtures, are also included in the first preferred class of polyhydroxy compounds. At least about 404, preferably at least about 50%, of the total number of nl groups are cycloaliphatic. Thus, the polyhydroxy compound may be entirely cycloaliphatic or a mixture of acyclic and cycloaliphatic compounds meeting the proportion limitations set forth above.

It is often convenient to prepare such polyhydroxy compounds by reduction of at least one corresponding polycarboxylic acid or ester thereof, which may be saturated or contain olefinic linkages. A typical example of a suitable polycarboxylic acid is linoleic acid dimer (hereinafter “
dimer acids) are mixtures consisting essentially of acyclic, monocyclic and bicyclic dicarboxylic acids, typically containing up to two olefinic bonds within the molecule.

A particularly suitable dimer acid is manufactured by Emery Industries (E
It is sold under the trademark Im-pOl 10j'OJ by Merry Engineering & Co., Ltd. Kirk-Os-r-(Ki
rk-Othmer), Encyclopedia of Chemical Technology (Encycl)
opedia of Ochemical Techno
According to J.D. Lo-gy), 3rd Edition, Volume 7, Pages 768-770, the structures of typical species encompassed by methyl esters of dimer acids are Formulas X, XI, and X■. Therefore, free dimer acid clearly includes free dicarboxylic acid with the corresponding structure.

Esters of formulas X, XI and XIl, the corresponding free acids and similar polycarboxylic acids and their esters are reduced in known manner, for example by the action of hydrogen in the presence of a hydrogenation catalyst or by lithium aluminum hydride. diols useful in the production of multifunctional acrylates. By reducing these and similar acids or esters, the reduction product contains diolefinic linkages that are saturated. For example, reduction with lithium aluminum hydride usually does not affect olefinic bonds, but some hydrogenation methods, such as in the presence of a palladium catalyst, reduce these to saturated bonds.

Thus, reduction of esters of formulas X, XI, and XIl produces diols of formulas X1ll, X■, and XV, respectively. In these formulas, the dashed line and the hydrogen atom in parentheses indicate that the corresponding carbon-carbon bond is either a single bond or a double bond, depending on the reduction method. Compounds containing only single bonds are often found to be somewhat preferred over similar double bond-containing compounds. A suitable diol mixture of this type is Henkle Corporation (
It is commercially available under the trade name "Dimerol J" by Henkel Corporation.

Other suitable polyhydroxy compounds belonging to this preferred class can be prepared by reduction of various acrylic acid-unsaturated fatty acid condensation products. These polyhydroxy compounds may be exemplified by formula XVI. Here, m may be, for example, 3 to 5, and p may be 7 to ? , and the sum of m and p is 12. A typical example of a commercially available dicarboxylic acid that can be used to reduce the formula
Co) 1550 Diacj4) J, which has the formula X■, and an addition product of linoleic acid and acrylic acid.

These are also described in Kirk-Othmer, supra, p. 779.

A second group of preferred polyhydroxy compounds consists of 1,2-alkanediols in which R1 has the formula X■. However, in formula X2, R3 is an alkyl group containing about 8 to 28 carbon atoms. Examples of suitable radicals R60 are 1-octyl, 2-methylheptyl, 1-nonyl, 2,3-dimethylhephthyl, 1-decyl, 2-dodecyl, 1-tetradecyl, 1-octadecyl. 1-Akonr and 1
-There is tocosyl. The formula R'' is preferable as just 6.
01 (, R6 is a group having about 7 to 2 carbon atoms
It has 7 and 2, most often about 9 to 17 alkyl groups, especially straight chain alkyl groups.

In another aspect of the invention, a multifunctional acrylate of formula I is used in admixture with at least one ester of formula XIX. where R7 is an aliphatic hydrocarbon group containing about 1 to 20 carbon atoms and free of acetylenic and polymerizable ethylenic unsaturation, n Ire 2 to 4, and m is less than n. 1 to 5. Also, at least about 50% of the carboxinate residues in the mixture have the formula Xx. This embodiment is particularly valuable when a capacitor with a low dissipation factor over a very wide temperature range is desired, in which case polyfunctional acrylates typically selected from the preferred subgroups mentioned above are used.

Evidently, the ester of formula
It is a mixed ester containing both carboxylate residues derived from carboxylic acids containing 19 acetylenic and non-polymerizable ethylenic unsaturations). The radical R7 is an alkyl group, in particular containing 1 to 7 carbon atoms, most often 2 to 4 carbon atoms. Examples of this type of carboxylic acid are acetic acid, propionic acid.

Butyric acid, 2-ethylhexanoic acid, lauric acid, Valmite/
acids, stearic acid and oleic acid.

K, which manufactures the capacitor of said co-pending application,
The deposition of ester mixtures is generally similar in that the carboxylate residues contribute to the volatility of the ester mixture, since the method often involves the deposition of monomers followed by polymerization to form the electrolyte member. conditions will be optimal. Therefore, it is most preferred that the R70 size and molecular weight be similar to that of the corresponding residue moiety in the acrylate group. In particular, R7 is an ethyl group, i.e. R7
Most preferably, 000H is propionic acid.

At least about 50, usually about 65 to 99, of the total number of carboxylate residues in the ester mixture of this aspect of the invention
%, preferably about 70-90% have formula XX.

That is, most of the carboxinate residues can be polymerized.

Component B in the composition of the present invention has at least one formula
is a substantially stable free radical of the species. In (2), each R1 is independently a tertiary lower alkyl group. Here, "low grade"
The term means that up to 7 carbon atoms may be present. Examples of tertiary lower alkyl groups include t-butyl and 3-ethyl-3-pentyl. The group X is C
Either H or N is acceptable.

Formula ■ in the attached table shows that an unpaired electron exists on one oxygen atom, but the molecular structure of this radical is actually a hybrid, and the unpaired electron is delocalized throughout the molecule. It is known to those skilled in the art that it has been commercialized. Therefore, it should be understood that formula (2) is simply an abbreviation commonly used to represent the molecular structure of component B.

Preferred free radicals of formula (2) for use as component B are each R
1 is t-butyl and X is OR. This compound is commercially available under the name "GalvinoXyL, 1". Corresponding compounds in which X is N are also known,
inoxyl ) J.

Component A is the main component in the composition of the present invention.

Component B is present in a small amount and in an amount that inhibits anaerobic polymerization, generally about 75-1500 ppm and about 100-100 ppm.
00 pl)m most often. Additionally, the composition may contain small amounts of other ingredients, such as those exemplified by the co-inhibitors mentioned above.

Another aspect of the present invention is a method for inhibiting early anaerobic polymerization of a composition containing component A as defined above, which method comprises adding component B to said composition in a small amount that inhibits anaerobic polymerization. It consists of adding.

This method is directed to a method for manufacturing a capacitor that includes the steps of depositing a monomer composition containing component A on an electrode under vacuum conditions and then subjecting the monomer composition to radiation-initiated polymerization to form a dielectric layer. Especially valuable as an improvement.

Next, the present invention will be explained by examples. In this example, a monomer system consisting of epoxidized trimethylol-propane triacrylate containing 100 ppm of p-methoxyphenol was rapidly heated under nitrogen from 25°C to 176°C and then maintained at 176°C. The time to reach the peak of polymerization exotherm detected by differential thermal analysis was measured.

The exothermic peak for the composition containing no other inhibitors was 4.2 minutes. "For the composition containing 1000 ppm of Galpinoxyl J, the exothermic peak occurred at 32 minutes.

In a series of tests similar to those described above, except that heating to 150°C was carried out at 10°C/min, no exothermic peak was observed in the composition containing 1 galbinoquine even after 32 minutes. 1.2- and 1,4-naphthoquinones 2.
In the case of known inhibitors such as 2.6.6-titramethylbiveridinoquine free radical, an exothermic peak was observed at a much shorter time.

Similar results are obtained with compositions containing 1100 pp each of sil-methoxyphenol and ``galpinoxyl'' or azagalpinoxyl, both of which are predominant from the difunctional acrylate of formula (1).

Attached formula I R1 (00-0-CH,)nRI
R3 formula nl R'0O-0-CH2 H! Formula IV HO(CH2), 0H OR, 0H OEs (!H.

Appendix (Continued 1) Formula ■ 0H3(CHrir-OR('CH,)sC!H2O0-
CH-CH.

0H surprise 0O-CH-CH2 Expression ■ 0H,0O-CH-CH2.

l ll 0Hs(CH,)r-0-(CH2)s-CH2QC!
-0R-CH2CH! 00. -CH-CH2 Formula X ol[(, (CB,)7an(CH2)8aooca3
噌OHs(CH2') γc-an(CH2)γ0OOC
H3 formula X1 Appendix (Continued 2) Formula Xn Formula Appendix (Continued 4) Formula XD ( l -00-0=CH2

Claims (21)

[Claims] (1) (A) Most of the formulas are ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1 is an aliphatic or alicyclic group containing at least 10 carbon atoms, and R^ 2 is hydrogen or a hydrocarbon group containing 1 to 5 carbon atoms, and n is 2 to 6
There is a formula ▲ mathematical formula, chemical formula, table, etc. ▼ (in the formula, each R^3 is independently a tertiary lower alkyl group, and X is CH or N. (2) The composition according to claim 1, wherein each R^3 is t-butyl. (3) The composition according to claim 2, wherein R^2 is hydrogen or methyl, and n is 2 or 3. (4) The composition according to claim 3, wherein X is CH. (5) The composition of claim 4, wherein component B is present in an amount of about 75 to 1500 ppm. (6) R^1 is an aliphatic, cycloaliphatic, or mixed aliphatic-cycloaliphatic group having from about 10 to 40 carbon atoms and optionally containing up to about 3 olefinic linkages; Claim 5, characterized in that the bond is non-conjugated.
The composition described in Section. (7) A patent characterized in that component A has the formula ▲A mathematical formula, a chemical formula, a table, etc.▼ (In the formula, r and s are each 7 or 8, and the sum of r and s is 15) A composition according to claim 6. (8) Formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R^1 is an aliphatic or alicyclic group containing at least 10 carbon atoms, and R^2 is hydrogen or a carbon atom It is a hydrocarbon group containing ~5 pieces, and n is 2-6
at least one polyfunctional acrylate having
There is a formula ▲ mathematical formula, chemical formula, table, etc. ▼ for the amount that inhibits anaerobic polymerization in a composition containing seeds in a small amount ▼ (wherein each R^3 is independently a tertiary lower alkyl group, is CH or N). (9) The method according to claim 8, wherein each R^3 is t-butyl. (10) The method according to claim 9, wherein R^2 is hydrogen or methyl, and n is 2 or 3. (11) The method according to claim 10, wherein X is CH. (12) The method of claim 11, wherein the amount of free radicals is about 75-1500 ppm. (13) R^1 is an aliphatic, cycloaliphatic, or mixed aliphatic-cycloaliphatic group having from about 10 to 40 carbon atoms and optionally containing up to about 3 olefinic bonds; 13. A method according to claim 12, characterized in that the bond is non-conjugated. (14) The polyfunctional acrylate is characterized by having the formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (in the formula, r and e are each 7 or 8, and the sum of r and s is 15). 14. The method according to claim 13. (15) Formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 is an aliphatic or alicyclic group containing at least 10 carbon atoms, and R^2 is a hydrogen or carbon atom A monomer composition comprising at least one polyfunctional acrylate containing 5 hydrocarbon groups, where n is 2 to 6) is deposited on an electrode under vacuum conditions, and then the monomer composition is subjected to radiation initiation. In the manufacturing method of capacitors, which includes the step of forming a dielectric layer through polymerization, there are formulas, mathematical formulas, chemical formulas, tables, etc. that inhibit anaerobic polymerization in small amounts (in the formula, each R^3 is by incorporating into the monomer composition at least one substantially stable radical having a tertiary lower alkyl group, X is CH or N. A method characterized in that anaerobic polymerization is inhibited. (16) The method according to claim 15, wherein each R^3 is t-butyl. (17) The method according to claim 16, wherein R^2 is hydrogen or methyl, and n is 2 or 3. (18) The method according to claim 17, wherein X is CH. (19) The method of claim 18, wherein the amount of free radicals is about 75-1500 ppm. (20) R^1 is an aliphatic, cycloaliphatic, or mixed aliphatic-cycloaliphatic group having about 10 to 40 carbon atoms and optionally containing up to about 3 olefinic bonds; 20. A method according to claim 19, characterized in that the bond is non-conjugated. (21) The polyfunctional acrylate is characterized by having the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (where r and s are each 7 or 8, and the sum of r and s is 15). 21. The method according to claim 20.