AU626496B2

AU626496B2 - Acylation and sulfonation of silylketene acetals

Info

Publication number: AU626496B2
Application number: AU76139/91A
Authority: AU
Inventors: Gordon Mark Cohen; Timothy David Costello; Clyde Spencer Hutchins; Hans Jurgen Reich; Harry Joseph Spinelli
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1986-05-29
Filing date: 1991-04-29
Publication date: 1992-07-30
Anticipated expiration: 2007-05-21
Also published as: AU7512887A; AU7613991A; NO911451L; EP0272285A1; NO880368L; KR880701219A; DK42688D0; AU612581B2; WO1987007265A1; EP0272285A4; KR910002674B1; NO880368D0; JPH01500198A; NO911451D0; DK42688A

Description

'I

1ix i 'I II-- AUSTALA 6 9 Form PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification Lodged: Accepted: Lapsed: Published: SPriority: S Related Art: 0 *s Name of Applicant: o Address of Applicant: TO BE COMPLETED BY APPLICANT E.I. DU PONT DE NEMOURS AND COMPANY 1007 Market Street, Wilmington, Delaware 19898, United States of America Actual Inventors: Gordon Mark Cohen, Harry Joseph Spinelli, Clyde Spencer Hutchins, Timothy David Costello and Hans Jurgen Reich.

4; 1 Address for Service: CALLINAN LAWRIE, Patent Trade Mark Attorney, 278 High Street, Kew, Victoria 3101, Australia.

Complete Specification for the invention entitled: "ACYLATION AND SULFONATION OF SILYLKETENE ACETALS" The following statement is a full description of this invention, including the best method of performing it known to me:-

V,

TITLE

Acylation and Sulfonation of Silylketene Acetals BACKGROUND OF THE INVENTION Field of the Invention This invention relates to durable epoxy (meth)acrylic polymers with oxirane-containing terminal groups; to processes for preparing beta-ketoesters and beta-sulfonylesters from silylketene acetals; and to block and chain-extended polymers prepared therewith.

I o0.1 Background 0 Epoxy resins are widely used today in surface coatings, 0 adhesives, castings, laminates, and encarsulation of electronic 0 o parts. Most of these epoxy -esins are prepared by the reaction of 2,2-bis (4'-hydroxyphenyl) propane [bisphenol A] and epichlorohydrin. This generates a polymer with a backbone 0 composed of ether links between bisphenoi A structures and hydroxy propylene moieties. There is also one epoxy group (oxirane) at each end of the polymer backbone. These resins can be cured by reacting their epoxy groups with crosslinking agents, such as anhydrides, amines, and acids. When cured, the epoxides a 4 have good tensile strengths, excellent electrical insulating properties, and have outstanding adhesion to many surfaces, However, a major weakness of these conventional epoxy resins is their poor outdoor durability. The ether links in their backbone as well as the aromatic rings lead to poor UV and oxidative stability. Because of this limitation, these epoxy resins cannot be used in systems that require long term outdoor exposure.

Previously, two approaches have been taken to make durable epoxides. One involves the synthesis and use of low molecular weight cyclic or acyclic diepoxides and the other -2- (C

A

involves the synthesis and use of copolymers of glycidyl methacrylate (GMA). Both of these approaches, though they generate epoxides that are more durable than bisphenol A based resins, have significant deficiencies. The cyclic-type of epoxides are not polymers and have only a very low molecular weight segments binding the two epoxy groups. These materials tend not to have the superior physical properties of conventional epoxides. The systems based on random copolymers of GDLA do not o. have the controlled placement of the epoxy groups. That is, o o a °fQ@ these copolymers have the epoxy groups distributed randomly along *I a the entire backbone of the methacrylate chain. The placement of 0 o. the epoxy groups at the end of the polymer chain, as seen in o o bisphenol A epoxides, imparts important properties such as toughness. The random placement of the epoxy groups lowers final properties.

The bisphenol A-based epoxides are well known and are o A30 o o 0 items of commerce the Epon resins from Shell and the 0* 0 ,o family of DER epoxides from Dow). The cyclic epoxides have also been commercially available Union Carbide's ERL-4221, a o o0 cycloaliphatic diepoxide).

o0 0 Methacrylate copolymers that use randomly distributed o 0 0 GMA have been used in the coatings industry Patents 3,817,946; 4,027,066; 3,730,930; 4,346,144). However, no patents or publications have been identified that report ABA triblock methacrylate polymers with GMA in the A segments.

Patents and publications concerning Group Transfer Polymerization CGTP) disclose the ability to make block structures using that process. However, none of these discloses the epoxy triblock structure, nor the advantages of that structure as a durable epoxy resin. For a detailed discussion 3 i i i -LI: IC__VCI- ri 1..

of GTP see Webster et al., "Group Transfer Polymerization A New and Versatile Kind of Addition Polymerization", J. Am. Chem. Soc.

105, 5706 (1983); and United States Patents 4,414,372; 4,417,034; 4,508,880; 4,524,196; 4,581,428; 4,588,795; 4,598,161; 4,605,716; 4,622,372; and 4,656,233; 4,711,942; 4,681,918; and 4,822,859. The disclosures of these patents are hereby incorporated by reference. More specifically, these patents disclose processes for polymerizing an acrylic or maleimide monomer to a "living" polymer in the presence of: l'Q an initiator having at least one initiating site and which is a tetracoordinate organo (Si, Sn or Ge) compound, 'o including such compound having at least one oxygen, nitrogen or sulfur atom attached to Si; and (ii) a co-catalyst which is a source of fluoride, bifluoride, cyanide or azide ions or a suitable Lewis acid, Lewis o base or selected oxyanion.

0 0 0 The aforesaid patents also disclose capping of "living" ,O0 silylketene acetal groups with agents containing capping functions such as -CHO, -NCO, -Br, -Cl and -TiCl 3 S -20 In GTP processes, the polymer produced is "living" in o" that the polymerization is characterised by the presence, in the growing and in the grown polymer, of a moiety containing the aforesaid metal at "living" ends and the activating substituent or diradical, or a tautomer thereof, at "nonliving" ends of the polymer.

Monomers which are useful in GTP are of the formula

CH

2 =C(Y)X wherein: X is -CN, -CH=CHC(O)X' or Y is -CH 3 -CN or -CO 2 R, provided, however, when X is -CH=CHC(O)X', Y is -H or -CH 3 SI I i i 1! X' is -OSi(R') 3 -OR or -NR'R"; each R 1 independently, is H or a hydrocarbyl radical which is an aliphatic, alicyclic, aromatic or mixed aliphatic-aromatic radical containing up to 20 carbon atoms, provided that at least one R 1 group is not H; R is a hydrocarbyl radical which is an a3iphatic, alicyclic, aromatic or mixed aliphatic-aromatic radical containing up to 20 carbon atoms, or a polymeric radical containing at least 20 carbon S1 Q atoms, any of said radicals optionally containing one or more ether oxygen atoms within aliphatic segments thereof, optionally containing one or more functional 0 substituents that are unreactive under polymerizing conditions, and optionally containing one or more reactive substituents of the formula -Z'(O)C-C(Y 1

)=CH

2 Swherein Y 1 is H or CH 3 and Z' is 0 or NR'; and S0 0 00 each of R' and R" is independently selected from C 1 -4 ou alkyl.

Initiators which are useful in GTP include the o02.0 silicon-containing initiators of United States Patents 4,414,372; 4,524,196; 4,417,034; 4,508,880; 4,581,428; 4,656,233; 4,711,942 and 6,681,918, supra. Initiators which are preferred for use herein are of the formula selected from (R 1 3 MZ, (R 1 2

M(Z

1 2 and O[M(R 2

X

1 2 wherein:

R

1 is as defined above; Z is an activating substituent selected from the group consisting of 5 7 A R'0

II

-CN,

0

R

C-C-

Cm-- 0

R

2 I I C C

(CH

2 Got* a9 V 4 0 9 0 0 R 2

-N=C=C-R

3

OC==C-R

2 X' R 3

C

2 (CH -SR, -OP 2

-OP(OR

1 2 -OP[OSiL(R) 3 1 2 arnd mixtures thereof wherein R, X' and Zrare as defined above;

Z

1 is the activating substituent

-OC=C-R;

X' R' m, is 2, 3 or 4; n is 3, 4 or M is Si, Sn or Ge, provided, however, when Z is 0 0 0 0 0 P 0 00 04.

-O 2 CH) or 2 )n M is Sn or Ge; and each of R 2 and R 3 is independently selected from H- and hydrocarbyl, defined as for R above; at least one of any R, R 2 and R 3 in the initiator optionally containing one or more initiating substituents of the formula -Z 2 -M (R 1 3 wherein M and R 1 are as def ined above;

Z

2 is an activating diradical selected fromt the group consisting of 0."0 0 0 0 0 -Z-C=C (R 2

(R

3 0- 0 O R 2 2 11 II __1 -C (R 2

=CX,

0- C C-

CH

2 C

'-CH)

-7

V

A V 0 C- 2 and mixtures

CN

(CH2 Ik H2 thereof, wherein R R Z' mn and n are as defined above provided however when Z 2 is 0 0

-,CH-

2 )/n ~1O M is Sn or Ge, 1' o 0 23 0(b) R 2 and R 3 taken together are 0 0

CC

0 0 R 0 -C CX' or -0C=C(R) and/or Z 2 is 0 0 0 X' and either R 2 or R 3 taken together are 2500 -8- C iL4 r :e -1if Z is

R

2

O

1

II

C--CX' or -OC=C(R) (R 3 and/or

R

3

X'

0

Z

2 is -C(R 2 R. A. Olofson and J. Cuomo, Tetrahedron Lett., 21, 819 Ig"' (1980) disclose fluoride ion catalyzed 0-acylation of silyl enol 00 a ethers with compounds of the type RXC(0)F where X is O, NR' or a single bond, R is a cyclic or acyclic aliphatic radical and R' O 9o 00 o" enol ethers is not reported.

United States Patent 4,482,729 discloses reactions of non-polymeric fluorine-containing silylketene acetals such as

CF

3 CH=C(OSi (CH 3 3

OCH

3 including reaction with a propionyl chloride, to form the alpha-trifluoromethyl-beta-ketoester oo CHCH 2 C CH(CF) CO 2

CH

3 Electron-withdrawing substituents such as -COOR attached to the double bond of silylketene acetals are known to promote reaction with acyl chlorides and anhydrides; a0 4 0 0: -CF 3 is strongly electron-withdrawing. Japanese Patent Application 53/034-719 discloses the preparation of alpha-hydroxysuccinic acid esters by reaction of non-polymeric silylketene acetals with alpha-ketocarboxylic esters in the presence of a Lewis acid catalyst.

E. Colvin "Silicon in Organic Synthesis" page 234, Butterworths, Boston (1981); and M.W. Rathke and D.F. Sullivan, Tetrahedron Lett., 1297 (1973) show that even with amine promoters, acylation of silylketene acetals (SKA) does not occur with acyl chlorides when the SKA contains two a-substituents.

9 -ili

L_

,4i Polymerizing methacrylate chain ends have two such substituents.

These references further disclose that a stoichiometric amount of amine is required even when less than two a-substituents are present.

Acylation of non-polymeric silyl enol ethers is well known. For example, R. Noyori, et al., Tet., 37, 3899 (1981) disclose the acylation of silyl enol ethers in the presence of trimethylsilyl triflate as the (Lewis acid) catalyst. R.E.

o Tirpak et al., J. Org. Chem., 47, 5099 (1982) disclose acylation o 1 0 G of silyl enol ethers with acyl chlorides in the presence of Lewis acid promoters. E.P. Kramarova et al., J. Gen. Chem. USSR, 43, o 1843 (1973); ibid., 45, 469 (1975) disclose C-acylation, usually, of silyl enol ethers by reaction with acyl chlorides or anhydrides; the former require catalytic amounts of mercuric chloride; the latter contain activating alpha-halogen atoms.

a °o G.S. Burlachenko et al., J. Gen. Chem., USSR, 43, 1708 e o (1973) disclose the reaction of alkyl silylketene acetals with acetyl chloride or triethylsilylacetyl chloride. The reaction produces alkylsilyl derivatives of acetoacetic enol esters, e.g.

CH

3 COC1 2CH 2 =C (OCH) OSi (C 2

H

5 3 CH 3 C (OSi [C 2

H

5 3) =CHCOCH 3 0 A. Wissner, J. Org. Chem., 44(25), 4617 (1979) discloses a similar reaction to that of Burlachenko et al., and further shows that acid-catalyzed hydrolysis of the enol ester provides a beta-ketoester. The reactions of Burlachenko et al. and Wissner require that the silylketene acetal contain an olefinic hydrogen atom, which is released during the reaction as HC1.

G. Rousseau et al., Tetrahedron Lett., 26(35), 4191 (1985) disclose the C-acylation of non-polymeric silylketen acetals with acryloyl and mono-substituted actloyl chlorides to form beta-ketoesters. The reaction is catalyzed by Lewis acias such as zinc bromide. Mainly, beta-ketoesters are produced without Lewis acid catalysis when alpha-beta 'nsaturated acyl chlorides are used, the reaction involving addition to carbon-carbon double bonds, not to carbonyl.

The invention which will be described in greater detail hereinbelow also is concerned with ABA triblock polymers that have glycidyl methacrylate (GMA) as the A segments and standard (meth)acrylate monomers as the B segment. These methacrylate triblock polymers have now been synthesized with epoxy groups 0 located only at the ends of the polymer chain. Because their backbone is a (meth)acrylate (meaning acrylate and/or a a 00#' methacrylate) structure, these epoxy resins should be significantly more durable than conventional bisphenol A based epoxides. These new polymers should have better final properties than the cyclic epoxides because the backbone is nolymeric in nature. They should be better than conventional GMA polymers that have a random distribution of epoxy groups because all of the epoxy groups are now located at the end of the chains, similar to bisphenol A epoxides.

^o0 SUMMARY OF THE INVENTION The invention resides in a process for the preparation of an ABA block copolymer having a center segment between two end segments, each end segment being an oxirane-containing acrylic or methacrylic moiety, said center segment being an acrylic or methacrylic moiety not containing oxirane groups, by reacting the ingredients by Group Transfer Polymerization (GTP) techniques.

The invention also is concerned with the preparation of -11 LL.L. ABA triblock polymers that have glycidyl (meth)acrylate (GMA or GA) as the A segments and standard (meth)acrylate monomers as the B segment. These methacrylate triblock polymers have now been synthesized with epoxy groups located only at the ends of the polymer chain. Because their backbone is a (meth)acrylate structure, these epoxy resins should be significantly more durable than conventional bisphenol A based epoxides. These new polymers should have better final properties than the cyclic epoxides because the backbone is polymeric in nature. They og 10 should be better than conventional GMA polymers that have a random distribution of epoxy groups because all of the epoxy groups are now located at the end of the chains, similar to 00 0 bisphenol A epoxides.

DETAILED DESCRIPTION OF THE INVENTION There are at least four major approaches to making ABA 0\ polymers according to the invention. They are- start with 0 64 a monofunctional initiator and polymerize in three steps, GMA 4o; first, which makes the first A segment, followed by methyl methacrylate (MMA) which adds onto the A segment and makes an AB ."42.0 polymer, and finally GMA again which completes the ABA structure; 4 4 start with a difunctional initiator and polymerize the monomers in two steps, MMA first, which creates the middle B segment, followed by GMA which will add onto both ends simultaneously because of the difunctional initiator, making the ABA polymer; start with monofunctional initiator, polymerize in two steps, GMA first, making the A segment, followed by MMA, making an AB polymer, and finally coupling the polymer to unite the two AB polymers at the B end and create an ABA polymer; (4) start with an epoxy containing initiator, the A segment, polymerize the MMA, making an AB polymer, and finally, couple the i-12 i t then coupling agent is added to react two center segments together to form said ABA block copolymer.

2 i polymer which unites the two AB polymers at the B end and creates an ABA polymer.

Monomers which can be used to prepare the center section include, for example, alkyl methacrylates and acrylates that can be used to prepare acrylic polymers. Included are methyl methacrylate, ethylmethacrylate, butyl methacrylate (BMA), hexyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, lauryl methacrylate, stearyl methacrylate, cyclohexyl c methacrylate, isodecyl methacrylate, propyl methacrylate, phenyl S00 methacrylate, isobornyl methacrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, °o06' hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, lauryl acrylate, stearyl acrylate, cyclohexyl acrylate, isodecyl acrylate, phenyl acrylate, isobornyl acrylate, blocked (meth)acrylic acid monomers which can be unblocked after 910* S S" polymerization, including trimethyl silyl methacrylate and 1-butoxyethyl methacrylate, and the like. Both the end and center sections can include other functionality, such as for crosslinking, so long as it does not interfere with 20 polymerization.

Example 1 describes supra, how one might make GMA//BMA//GMA using monofunctional initiator, two monomer feeds, and a coupling agent. Example 2 describes supra, how one might make GMA//BMA//GMA using an epoxy initiator, a monomer feed, and a coupling agent. The coupling agent is preferably diphenyl terephthalate, but it could be other suitable materials.

Following are definitions of terms used in the Summary of the Invention, supra. By "acyl" is meant the moiety which remains after removal of a hydroxy group from an organic carboxylic acid. By "sulfonyl" is meant the moiety which remains 13 after removal of a hydroxy group from an organic sulfonic acid.

By "hydrocarbyl radical" is meant a radical consisting essentially of hydrogen and up to about 20 carbon atoms. By "substituted hydrocarbyl radical" is meant hydrocarbyl which contains one or more functional substituents that are inert under reaction conditions and/or one or more ether oxygen atoms within aliphatic segments thereof.

By "polymeric radical" is meant a polymeric radical o" o. containing more than 20 carbon atoms; the radical may contain the "L0 intra-chain heteroatoms 0, N or S and/or substituents that are 0 inert under reaction conditions.

o 0 By "aryl" is meant an aromatic radical having at least o o a six carbon atoms. By "substituted aryl" is meant aryl which contains one or more aliphatic substituents or other substituents 15 that are inert under reaction conditions.

00 a a By "a selected anion or oxyanion" is meant a fluoride, difluorotrimethylsilicate, bifluoride, cyanide or azide anion, or an oxyanion defined as in U.S. Patent 4,588,795, or the radical X from the acyl compound or Y from the sulfonyl compound.

The selected anion or oxyanion catalysts also include the Group o Transfer Polymerization catalysts described in the aforesaid GTP patents, especially in U.S. Patents 4,508,880 and 4,588,795.

By "silicon activating group" is meant a leaving group which is capable of displacing silicon from the silylketene acetal under reaction conditions. Suitable silicon activating groups, which include the groups -F,-OAr or -OC(0)R 6 also function as catalysts in the invention process, thus reducing the amount of added catalyst required to sustain the reaction. In the formula R 6 is hydrocarbyl or substituted hydrocarbyl.

The following preferred embodiments are within the scope -14 j i i 9' 01 9e 00 0O Oo 90 o 9 9 of the invention as described inthe Summary of the Invention, supra.

In the following examples of the invention process, and in comparative experiments, parts and percentages are by weight and temperatures are in degrees Celsius unless otherwise specified.

Example 1 (GMA//MMA//GMA 4//40//4) Mono-Initiator, 2-Feed, Coupling Agent A 250 ml round bottom flask, equipped with a mechanical "t stirrer, thermometer, and nitrogen inlet, is charged with dimethoxyethane glyme (18.6 1-trimethylsiloxy-l-i-butoxy-2 S methylpropene (2.1 g, 0.0097 mole), and glycidyl methacrylate (5.6 g, 0.0394 mole). The flask is cooled to 10 0

C.

Tetrabutylanmronium m-chlorobenzoate TBACB (200 il of a 1.0 M solution in acetonitrile) is injected into the flask. Feed 0* I consists of glyme (3.0 g) and tetrabutylammonium 9a6 m-chlorobenzoate (200 pl of a 1.0 M solution). It is started minutes after the first injection of TBACB. It is added over 56 minutes. Feed II is methyl methacrylate (20.0 g, 0.20 mole).

It is started simultaneously with the start of the feed I. Feed II is added over 35 minutes. Twenty minutes after feed II is completed, diphenyl terephthalate (1.54 g, 0.0048 mole) is added and the reaction is allowed to remain at room temperature overnight. This couples living polymer chains together. Then methanol (4.0 g) is added. This should be an ABA block polymer (GMA//MMA//GMA with 4 epoxy groups on each end of the polymer chains.

Example 2 (GMA//MMA//GMA 17/40//1) j

I

Ii it l:i 4 i 1 L i Epoxy Initiator, 1-Feed, Coupling Agent A 250 ml round bottom flask, equipped with a mechanical stirrer, thermometer, and nitrogen inlet, is charged with tetrahydrofuran (18.6 and l-trimethylsiloxy-l-glycidoxy-2 -methylpropene (2.16 g, 0.010 mole). The flask is cooled to C. Tetrabutylammonium m-chlorobenzoate (100 il of a 1.0 M solution in acetonitrile) is injected into the flask. Feed I consists of tetrahydrofuran (4.0 g) and tetrabutylammonium m-chlorobenzoate (100 pl of a 1.0 M solution in acetonitrile).

S

0 It is started 10 minutes after the first injection of TBACB.

Feed II is methyl methacrylate (20.0 g, 0.20 mole). It is started simultaneously with Feed I and is added over 30 minutes. Twenty 0 minutes after Feed II is completed, diphenyl terephthalate (1.08 g, 0.005 mole) is added and the reaction is allowed to remain at room temperature overnight. This couples the living polymer o S chains together.

This should be an ABA block polymer (GMA//MMA//GMA with one epoxy group on each end of every polymer chain.

1"S210 This application is a divisional application of S Australian Patent Application Number 75128/87 and the disclosure thereof is incorporated herein by way of reference.

-1

I-

.16

Claims

1. A process for the preparation of an ABA block copolymer having a center segment between two end segments, each end segment being an oxirane-containing acrylic or methacrylic moiety, said center segment being an acrylic or methacrylic moiety not containing oxirane groups, by reacting the ingredients by Group Transfer Polymerization techniques, the process further characterized in that monofunctional initiator is used with appropriate monomers to polymerize together and in sequence: a first end segment, then a center segment, then coupling agent is added to react two center segments together to form said ABA block copolymer.

2. The process of Claim 1, wherein the monomer units of the end segments are glycidyl methacrylate, and the monomer units of the center segment are selected from acrylic and methacrylic I- monomers.

3. The process of Claim 2, wherein the monomer units of the center segment are methyl methacrylate.

4. The process of Claim 1, wherein the coupling agent is diphenyl terephthalate.

5. A process for the preparation of an ABA block copolymer having a center segment between two end segments, each end-segment being an oxirane-containing acrylic or methacrylic moiety, said center segment being an acrylic or methacrylic moiety not containing oxirane groups,

17- A i by reacting the ingredients by Group Transfer Polymerization techniques, the process further characterized in that oxirane-containing initiator is reacted with appropriate monomers to polymerize with the center segment, then coupling agent is added to react two center segments together to form said ABA block copolymer. 6. The process of Claim 5, wherein the monomer unito of the j end segments are glycidyl methacrylate, and the monomer units of the center segment are selected from acrylic and methacrylic monomers. 7. The process of Claim 6, wherein the monomer units of the center segment are methyl methacrylate. S 8. The process of Claim 5, wherein the coupling agent is diphenyl terephthalate. 9. A process for the preparation of an ABA block copolymer segment between two segments, substantially as herein described 4 4 with reference to Examples 1 and 2. 10. A product of the process of any one of claims 1 to 9. 4 a t 0 DATED this 29th day of April 1991. E.I. DU PONT DE NEMOURS AND COMPANY By Their Patent Attorneys: CALLINAN LAWRIE U18 18 o i;