CZ296584B6 - Copolymer containing piperidine derivative, process for its preparation and use - Google Patents

Abstract

In the present invention, there is disclosed a copolymer of the general formula I, wherein XXX represents a main chain of said copolymer, and the polymeric precursor thereof being selected from the group consisting of polymers carrying in their side chain at least one vinyl or allyl group, and carrying in its side chain at least one piperidine derivative, Y represents a distant hydrocarbon chain, preferably (CHi2)im, wherein m is at least 2, Z denotes an oxygen atom or the group NH, Re1 represents alkyl containing 1 to 4 carbon atoms, or each two adjacent Re1 form a cycle, Re2 represents a hydrogen atom or alkyl containing 1 to 4 carbon atoms, preferably methyl, and n is at least 3, preferably 3. A preferable embodiment is represented by a butadiene copolymer of the general formula II, in which Z, Re1, Re2 and n are as specified above, Bd represents a butadiene monomeric unit and x and y represent numbers of the corresponding monomeric units in the chain. The invention further relates to a piperidine sulfanyl derivative of the general formula III, in which the symbols Z, Re1 and Re2 are the same as in the general formula I. Disclosed is also a process for preparing such copolymer in which a piperidine derivative of the general formula IV, in which Z, Re1 a Re2 are the same as in the general formula I, is brought into reaction with a thiolactone of the general formula V, in which n = 3 to 5, in an inert solvent and under elevated temperature, and the obtained piperidine sulfanyl derivative of the general formula III is the reacted with polybutadiene, having at least 5 % of type 1,2 monomeric units, in an inert solvent and in the presence of a radical initiator at a temperature ranging from 40 to 90 degC. The above-described copolymers can be used for stabilization of polymers.

Description

A copolymer of formula I wherein XXX is the backbone of the copolymer whose polymer precursor is selected from the group of polymers carrying at least one vinyl or allyl group in the side chain and which carries at least one piperidine derivative in the side chain, Y represents a spacer hydrocarbon chain, preferably _{(CH2) m,} wherein m is at least 2, Z is oxygen or NH, ^R1 is C1-4 alkyl, or two adjacent R ¹ form a ring, R ² is hydrogen or C _m alkyl, preferably methyl, and n is at least 3, preferably 3. A preferred embodiment is a butadiene copolymer of formula II wherein Z, R ¹ , R ² and ⁿ have the same meaning as in formula I, Bd denotes the butadiene monomer unit and x and y denote the respective monomer units in the chain . The invention further relates to a sulfanyl piperidine derivative of the general formula III in which Z, R ¹ and R ² and ⁿ have the same meaning as in the formula I. In the preparation process, the piperidine derivative of the general formula IV wherein Z, R ¹ and R ² as defined in formula I, is reacted with a thiolactone of formula V, wherein n = 3 to 5, in an inert solvent at elevated temperature, and the resulting sulfanyl piperidine derivative of formula III is reacted with polybutadiene having a monomeric unit of type 1,2 at least 5%, in an inert solvent in the presence of a free radical initiator at a temperature of 40 to 90 ° C. The described copolymers can be used to stabilize polymers.

Φύ *

A copolymer containing a piperidine derivative, a process for producing and using

Technical field

The invention relates to copolymer stabilizers carrying sterically protected piperidine structures.

BACKGROUND OF THE INVENTION

Polymer stabilizers are substances that protect polymer materials from degrading external influences (heat, light, oxygen), which impair their utility properties. A disadvantage of conventional low molecular weight stabilizers with a molar mass of up to several hundred grams ^per liter is that, especially at higher temperatures or other extreme conditions, the polymer matrices volatilize or are eluted with liquid, thereby decreasing their concentration. Therefore, polymeric stabilizers are developed as an alternative which carry efficient structures bonded by chemical bonding to their chains. Such polymer stabilizers have a much lower diffusion rate in the polymer matrix and thus remain in the material. An important type of such stabilizers are those that carry a sterically protected piperidine structure, the so-called HALS, i.e. a hindered amine light stabilizer [e.g. WWY Lau and PJ Qing in: Desk Reference of Functional Polymers (R. Arshady, Ed.), Chap. 4.5, p. 621, Am. Chem. Soc., Washington, DC, 1997]

There are two main ways to produce polymeric HALS stabilizers:

1. A polymerizable group, mostly a vinyl double bond, is attached to the low molecular weight HALS molecule, and the resulting monomer is copolymerized with another monomer or homopolymerized (see, e.g., Kurumaya, Y. Nanbu and K. Yoshikawa: JP 2002211110, A. Steinmann, C.-EM Wilen, J. Naesman and H. Anders: DE 199 27 492) or undergoing another type of reaction (e.g. K. Stoli, J. Simonin and JR Webster: EP 982 356).

2. By a suitable polymer-analogous reaction, a low molecular weight stabilizer is attached to the preformed polymer by chemical bonding [see, e.g., I. Lukac, S. Chrnella, J.F. Pilichowski, and J. Lacoste: J. Macromol. Sci. Pure Appl. Chem. A35, 1337 (1998) or I. Hayashi and T. Kato: JP 9302026.].

A disadvantage of both of these methods so far has been their comparatively demanding synthesis.

SUMMARY OF THE INVENTION

The present invention provides a simple method of making a polymeric stabilizer by first introducing a sulfanyl group (-SH) into a molecule containing a sterically hindered piperidine structure (HALS) and attaching the resulting derivative by radical addition to the double C = C bonds on the side chains hanging from a backbone of a suitable polymeric or oligomeric precursor, e.g., to vinyl groups of the type of polybutadiene which, in addition to 1.4 units, i.

-CH ₂ -CH = CH-CH ₂ containing all 1,2 units:

-CFL-CH ² I ch = ch ₂

- 1 GB 296584 B6

The radical addition of mercaptan to the vinyl group of polybutadiene by means of a radical initiator has already been described for another system [see, e.g., W. S. E. Femando and G. Scott: Eur. Polym. J. 16,

971 (1980) or J. Podešva and J. Kovarova: J. Appl. Polym. Sci. 87, 885 (2003)].

The present invention provides a copolymer of the formula I,

(I) wherein XXX represents a backbone of the copolymer whose polymer precursor is selected from the group of polymers carrying at least one vinyl or allyl group in the side chain, the copolymer carrying at least one piperidine derivative in the side chain, Y being a spacer hydrocarbon chain, preferably ( CH ₂ ) m, wherein m is at least 2, Z is oxygen or NH, R ¹ is C 1-4 alkyl, or two adjacent R ¹ are each a ring, R ² is hydrogen or C 1-4 alkyl, preferably methyl, and ⁿ is at least 3 , preferably 3.

In particular, satisfactory results have been obtained by using a copolymer of the formula II,

(II) where Z, R ¹ , R ² and ⁿ have the same meaning as in formula I, Bd denotes the butadiene monomer unit and the x and y indexes represent the number of respective monomer units in the chain [x / (x + y ratio) indicates the molar content structure, preferably 5 to 15 mol. %], while the type of copolymer (statistical, alternating, block) is not specified. For the case where Z is oxygen, R ¹ is methyl, R ² is hydrogen and n - 3 is the copolymer of formula II referred to as IIa. For the case where Z is NH, ^R1 is methyl and ^R2 is hydrogen and n = 3, the copolymer of formula II known as IIb.

The present invention further provides a sulfanyl piperidine derivative of formula III:

(CHA-SH (HI) wherein Z, R ¹ , R ² and ⁿ have the same meaning as in Formula I. For the case where Z is oxygen, R ¹ is methyl, R ² is hydrogen and ⁿ = 3 is In the case where Z is NH, R ¹ is methyl, R ² is hydrogen and ⁿ = 3, the compound of formula III is referred to as IIIb.

The polymer of formula I is the product of the radical addition of a compound of formula III to the C = C double bonds in the side chains of a suitable polymeric substrate (precursor). Similarly, the butadiene copolymer of formula (II) is the product of the free-radical addition of a compound of formula (III) to the hanging vinylbutadiene vinyls. This addition requires a non-zero content of 1.2 units in polybutadiene (preferably in the range of 10 to 70 mol%) and it is preferred that the polybutadiene has a low molar mass, e.g. in the range of 1500 to 4000 g / mol. By appropriately selecting the reaction conditions (reaction time, component concentration) it is possible to control the degree of conversion of the free radical addition and thus the HALS content of the chain. With increasing conversion of this reaction, the molar mass of the product, its viscosity and polarity increase. For practical reasons (especially with regard to the method used for product isolation and purification), it is preferred that the content of monomer units carrying structure III does not exceed 20 mol. %.

Thus, the copolymer of formula (II) is prepared by reacting a compound of formula (III) with polybutadiene having a non-zero content of 1.2 units (so-called hanging vinyl) in an inert solvent at elevated temperature and under the action of a radical initiator.

It has been found that compounds of formula III are formed by reaction of compounds of formula IV,

(IV) wherein Z, R ¹ and R ² have the same meaning as for Formula I, with the thiolactone of Formula V,

(V) wherein n has the same meaning as in formula I (eg, the compound of formula V for n = 3 is γ-thiobutyrolactone), the ring of which opens in the reaction. In the case that Z is NH, ^R1 is methyl, ^R2 is hydrogen and n = 3, this reaction occurs at the boiling point of xylene in good yield without a catalyst, whereas when Z is oxygen, R ¹ is methyl R ² is hydrogen and ⁿ = 3, the reaction in xylene is slower and requires the presence of a catalyst. Examples of suitable catalysts include, but are not limited to, tin (II) -2-ethylhexanoate or aluminum triisopropoxide.

The polybutadiene substrate used was, inter alia, liquid rubber, i.e. a low molar mass polybutadiene terminated at both ends of the chain with hydroxyl groups (the so-called OH-telechelic polybutadiene), in this case secondary. Polymers of this type serve in practice as α, ω-diols for the production of, for example, polyurethanes. Upon addition of the copolymers of the present invention to such a diol, the resulting polyurethane will exhibit autostabilizing properties.

It has been found that 2,2'-azobis (2-methylpropionitrile) or other free radical initiator, toluene as solvent and 60 ° C as reaction temperature, are preferred for the free radical addition of the compound of formula III to polybutadiene to form a copolymer of formula II. As is standard in radical reactions, the reaction mixture was deoxygenated prior to the reaction either by repeated freeze-thawing and melting under vacuum or by bubbling with inert gas.

The degree of conversion of the addition and thus the content of the stabilizing structures in the copolymers of the formula II can be controlled by varying the ratio of the polybutadiene to the compound of the formula III as well as by changing the reaction time.

DETAILED DESCRIPTION OF THE INVENTION

For the quality of the products of formula (II), their purification, i.e. the removal of unreacted low molecular weight components of the reaction, respectively, is essential. by-products. The purification method is given in the respective examples. The purity of the compounds II and III was checked by HPLC on an Econ s.r.o. with LCP 4000 pump and 2084 variable wavelength UV detector. CGC 150x3 mm columns with modified silica gel SGX Cl8 packings were used under isocratic conditions at a flow rate of 0.5 ml / min, a wavelength of 220 nm and a feed of 1-10 μΐ. The mobile phase for the compounds of formula (II) was mostly methanol with 3 vol% water, and the mixture contained 0.2 g of hexadecyltrimethylammonium bromide v11. The mobile phase for the compounds of formula III was methanol with 0-10 vol% water.

Example 1. Preparation of the compound of formula IIIa, ie (2,2,6,6-tetramethylpiperidin-4-yl) -4-sulfanylbutanoate

39.15 g (0.383 mol) of γ-thiobutyrolactone, 12.05 g (0.077 mol) of a compound of formula IV wherein R ¹ is methyl, R ² is hydrogen and Z is oxygen, 0.4 g tin (II) The 2-ethylhexanoate catalyst and 29 mL of xylene were placed in an ampoule which was sealed after degassing and placed in an oil thermostat at 160 ° C for 94 h. Then, the vial was cooled and stored overnight at -18 ° C, then opened and the crystallized excess unreacted alcohol IV was filtered off. The filtrate was concentrated and the product distilled in a collar at 10 ^-5 Torr and a bath temperature of 110 ° C (bv 49-54 ° C). The product of formula IIIa, obtained in the form of a clear colorless syrup (yield 8.0 g, i.e. 51% of theory with respect to compound IV), crystallized after short storage at 8 ° C (mp 31-32 ° C). According to GC / MS and HPLC, it is chromatographically uniform. After prolonged standing of its solution in air, a gradual formation of the corresponding disulfide peak is observed on the HPLC record. Elemental analysis (calculated / found):% C 60.19 / 59.61,% H 9.71 / 9.42,% N 5.40 / 4.89,% S 12.36 / 12.38. 1 H NMR spectra (CDCl 3): 5.18, p, 1H (CH bound to O); 2.57, t, 2H (CH2 bound to C = O or SH); 2.42, t, 2H (CH2 bound to C = O or SH); 1.91, m, 4H (two CH 2 cycles); 1.56, broad band, 1H (NH in the cycle); 1.24, s, 6H (two CH 3); 1.16, s + d, 8H (two CH3 and CH2); 0.91, m (SH). Spectra ^I3 C NMR (CDC13): 172.49 (C = O); 68.76 (CH bound to O); 51.68, 2C (two quaternary C); 43.76, 2C (two CH ₂ per cycle); 34.62.2C (two CH ₃ ); 33.00 (CH ₂ bound to the C = O); 29.10 (CH ₂ bound to SH); 28.81, 2C (two CH ₃ ); 24.00 (CH ₂ , ie CH ₂ -CH ₂ -CH ₂ ). Mass spectra (70 eV): m / e (relative intensities) 259 (M ⁺ , 0.35), 244 (10.76), 142 (28.59), 124 (100), 58 (71.76).

Example 2. Preparation of the compound of formula IIIb, i.e. 4-sulfanyl-N- (2,2,6,6-tetramethylpiperidin-4-yl) butanamide g (0.098 mol) γ-thiobutyrolactone, 15.3 g (0.098 mol) of the compound of formula IV, wherein R ¹ is methyl, R ² is hydrogen and Z is NH, and 40 ml of xylene is charged to a flask and refluxed for 6 hours under argon. Then, xylene was distilled off, the residue is heated syrupy 6 h at 100 ° C at a pressure of 10 ^"5 Torr and then allowed to crystallize out under an inert atmosphere at 8 ° C. The yield of the product of formula IIIb is 23.3 g, i.e. 92% of theory. The crystals were recrystallized twice from the system ether / petroleum ether, mp 50 ° C, alternatively the product may be redistilled in the Kugelrohr apparatus at 10 ⁵ Torr and a bath temperature of 170 ° C (the TV 92 to 98 ° C). According to GC / MS and HPLC, they are chromatographically uniform, after prolonged standing of the solution in air, a gradual formation of the corresponding disulfide peak can be seen on the HPLC record. Elementary

Analysis (calculated / found):% C 60.42 / 59.81,% H 10.14 / 9.58,% N 10.84 / 10.86,% S 12.41 / 11.95 . 1 H NMR spectra (CDCl ₃ ): 5.46, d, 1H (NH bound to C = O); 4.22, m, 1H (CH bound to NH); 2.58, t, 2H _(CH2 bound to SH); 2.28, t, 2H (CH ₂ bound to the C = O); 1.98-1.84, m, 4H (two CH ₂ cycles); 1.34, broad band, 1H (NH in the cycle); 1.24, s, 6H (two _CH3); 1.11, s, 6H (two _CH3); 0.89, t, 3H (CH ₂ SH). ¹³ C NMR (CDCl ₃ ): 171.24 (C = O); 51.08, 2C (two quaternary C); 45.37, 2C (two CH ₂ per cycle); 42.60 (CH in cycle); 35.02, 2C (two CH ₃ ); 34.85 (CH ₂ bound to the C = O, i.e. CH ₂ -CO); 29.56 (CH ₂ , ie CH ₂ -CH ₂ -CH ₂ ); 28.59, 2C (two CH ₃ ); 24.16 (CH ₂ bound to the SH). Mass spectra (70 eV): m / e (relative intensities) 258 (M ⁺ , 0.74), 243 (20.31), 124 (100).

Example 3. Preparation of copolymers of formula IIa by addition of (2,2,6,6-tetramethylpiperidin-4-yl) -4-sulfanylbutanoate to liquid rubber

Production was carried out simultaneously in four reactors 1-4. Polybutadiene substrate used was liquid rubber produced by Kaučuk Kralupy as under the trade name Krasol LBH, which had hydroxyl groups at both ends of the chain, in this case secondary, having a number average molar mass Mn = 2370 g / mol, ratio by weight to number molar average molar mass M _{v /} / M _n = 1.13, content 1.2 units was 62%. The weight of Krasol LBH (5.0 g, i.e. 0.092 mol C = C double bonds) and 2,2'-azobis (2-methylpropionitrile) (0.8 g, i.e. 0.0048 mol) were always the same. 2,2,6,6-tetramethylpiperidin-4-yl) -4-sulfanyl butanoate different (see Table I). The mixtures were made up to 100 ml with toluene. The resulting solutions were deoxygenated and heated in an oil thermostat at 60 ° C for various times after which the vial in question was removed from the thermostat and cooled. Thereafter, toluene was evaporated from all the solutions to dryness. The evaporators were dissolved in t-butyl methyl ether so that the total volume of the solution was always 10 ml. These solutions were then placed in 100 ml glass centrifuge containers, each with 60 ml of methanol with 5 vol% water added under stirring, and the resulting spontaneously non-sedimenting suspension / emulsion of milky appearance was centrifuged for 30 min at 4000 rpm (2650 g). ) using a Jouan PK 110 laboratory centrifuge with a Q G26 / 1 rotor so that all four vessels float in ethylene glycol as an immersion liquid. The resulting clear supernatants were separated, the clear viscous sediments were dissolved in 5 ml of Z-butyl methyl ether each time, precipitated with 60 ml of methanol each with 5 vol% water and this cycle was repeated 5 times to remove low molecular weight impurities. Finally, the sediment free from residues of volatiles by heating to 100 ° C at a pressure of 10 ⁵ Torr, for 8 hours. Paradoxical decrease in yield with increasing backfill desired mercaptan is due to the fact that in the same direction of increasing the content of the piperidine structure, and therefore, the polarity of adduct, thus, it still becomes more difficult to precipitate with the mixture used (methanol with 5% by volume of water) and the cleaning losses increase. Table 1 further shows that all methods used to determine the content of butadiene units bearing the piperidine structure give approximately the same values within the experimental error.

-5GB 296584 B6

Table I. Production conditions of the copolymers of the formula Ha at constant weight of Krasol LBH resp. 2,2'-azobis (2-methylpropionitrile) (5.0 and 0.8 g, respectively)

Yield (G) Content of butadiene units carrying HALS (mol%) determined by: Reactor number compound IIIa Reaction time (h) EA,% C EA,% N EA,% S H HNMR G mol 1 0.92 0.0035 10 5.71 3.52 3.90 3.73 4.06 2 1.98 0.0076 24 4.61 6.33 7.00 6.64 7.48 3 3.11 0.0120 33.5 3.57 9.04 10.84 10.22 10.62 4 4.15 0.0160 48 2.35 10.98 11.22 10.87 12.06

EA ~ elementary analysis

Example 4. Preparation of Copolymers of Formula IIb by Adding 4-Sulfanyl-N- (2,2,6,6-tetramethylpiperidin-4-yl) butanamide to Liquid Rubber

Production was carried out simultaneously in four reactors 1 to 4. The same type of Krasol LBH was used as in Example 3. Charge of Krasol LBH (5.0 g, i.e. 0.092 mol C = C double bonds) and 2,2'-azobis (2-methylpropionitrile). (0.8 g, i.e. 0.0048 mol) was always the same, the 4-sulfanyl-N- (2,2,6,6-tetramethylpiperidin-4-yl) butanamide charge was different (see Table II). The next reaction and product isolation procedure was the same as in Example 3.

Table II. Production conditions of copolymers of the formula IIb at constant weight of Krasol LBH resp. 2,2'-azobis (2-methylpropionitrile) (5.0 and 0.8 g, respectively)

Reactor number Weight of compound 111b Reaction time - (h) Yield (G) Content of butadiene units carrying HALS (mol%) determined by: EA,% C EA,% N EA,% S * HNMR G mol 1 0.96 0.0037 7 5.60 3.28 3.95 3.87 4.75 2 2.00 0.0077 23 4.45 6.76 7.22 6.54 7.35 3 3.03 0.0117 31 3.60 9.64 10.72 10.61 12.65 4 4.07 0.0157 48 2.07 11.16 12.47 10.61 10.60

EA = elementary analysis

It can be seen from Tables I and II that by appropriate selection of the feed composition in the reactions of Examples 3 and 4 it is possible to control the content of those butadiene units of the product which carry the piperidine substituent (HALS).

Provided that both components of the mixture are compatible at the concentration used, the polymer of formula (I) may be admixed with any polymer which is thus protected from environmental degradation, in particular UV radiation. If the polymer has the general formula I at the ends of the chain hydroxyl groups, then can be let through these groups reacted with suitable dioxiranovými compounds to form autostabilizujících epoxy resins, or, provided that R ² is methyl and Z is oxygen, can be have these groups reacted with suitable diisocyanates to form autostabilizing polyurethanes.

Industrial applicability

The compounds of the invention can be used in the chemical industry as stabilizers in the production of polymers.

PATENT CLAIMS

Claims (9)

A copolymer of the formula I (I) wherein XXX represents a backbone of the copolymers whose polymer precursor is selected from the group of polymers carrying at least one vinyl or allyl group in the side chain and which carries at least one piperidine derivative in the side chain, Y represents a spacer a hydrocarbon chain, preferably (CH ₂ ) _m , wherein m is at least 2, Z is an oxygen atom or an NH group, R ¹ is C 1-4 alkyl, or two adjacent R ¹ are each a ring, R ² is hydrogen or C 1-4 alkyl, preferably methyl, and n is at least 3, preferably 3. The copolymer of claim 1, wherein XXX is a backbone of copolymers wherein the polymeric precursor is polybutadiene containing at least 5% monomer units of type 1,2, Z, R ¹ , R ² and ⁿ are as defined in claim 1, and Y is (CH ₂ ) ₂ , wherein the butadiene copolymer may be selected from the group consisting of statistical, alternating, block and branched. Third sulfanyl piperidine derivative of formula ΠΙ (Ul) wherein Z, R ^1, R ^{2 and} n are as defined in claim 1. A process for the preparation of a copolymer according to claim 2, characterized in that the piperidine derivative of the formula IV (IV) wherein Z, R ¹ and R ² have the same meaning as in claim 1, is reacted with a thiolactone of the formula In (V) wherein n = 3 to 5, in an inert solvent at elevated temperature, and the resulting sulfanyl derivative of piperidine of formula III is reacted with polybutadiene having a content of monomer units of type 1.2 of at least 5% in an inert solvent in the presence radical initiator at a temperature of 40 to 90 ° C. 5. A process for producing a copolymer according to claim 4, characterized in that as a sulfanyl piperidine derivative used is a compound of formula III wherein R ¹ is methyl, R ² is hydrogen and n = 3, such as polybutadiene using OH-telechelic polybutadiene molar weight 1500 to 4000 g / mol and containing 1.2 structures 10 to 70 mol. %, the free radical initiator used is 2,2'-azobis (2-methylpropionitrile) at 50 to 70 ° C and toluene is used as the inert solvent. A process for producing a sulfanyl piperidine derivative for the preparation of a copolymer according to claim 4, wherein Z is oxygen, R ¹ is methyl, R ² is hydrogen and ⁿ = 3, characterized in that the piperidine derivative of the general formula IV wherein Z is oxygen R ¹ is methyl and R ² is hydrogen, is reacted with a thiolactone of formula V wherein n = 3, in an inert solvent at elevated temperature and catalysis. Process for the preparation of the sulfanyl piperidine derivative according to claim 6, characterized in that tin (II) -2-ethylhexanoate is used as the catalyst and xylene is used as the inert solvent, and the reaction is carried out at a temperature of 140 to 170 ° C for at least 72 hours. h. A process for preparing a sulfanyl piperidine derivative for preparing a copolymer according to claim 4, wherein the piperidine derivative of formula IV wherein Z is NH, R ¹ is methyl and R ² is hydrogen is reacted with a thiolactone of formula V, where n = 3, in an inert solvent at elevated temperature. A process for the preparation of the sulfanyl piperidine derivative according to claim 8, characterized in that xylene is used as the inert solvent at boiling point for at least 4 h.