GB1577448A - Resinous terpene maleimide and process for preparing same - Google Patents

Description

(54) RESINOUS TERPENE MALEIMIDE AND PROCESS FOR PREPARING SAME (71) We, ARIZONA CHEMICAL COMPANY, a Corporation organized and existing under the laws of the State of Delaware, United States of America and having its executive offices at Wayne, State of New Jersey, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to novel resinous terpene maleimides, and to a process for preparing the same. More particularly, it relates to terpene maleimides obtained from a mixture of terpene maleic anhydride adducts containing not less than 85% terpene maleic anhydride mono-adduct and not more than 15% terpene maleic anhydride di-adduct.

It is important to emphasize that the terpene maleic anhydride adducts are mixtures of the possible adducts thus resulting in a liquid or viscous glassy residue rather than the crystalline materials produced from pure conjugated terpenes and maleic anhydride. These adduct mixtures are later used to prepared imide derivatives which are resinous materials and have no tendency to crystallize because of their varied structures. Although terpene maleic adducts are known (e.g. U.S. Patent No. 2,208,321, lines 10-23), control of their composition is not.

It is known that polyimides can be variously prepared from dianhydrides and diamines.

However, as far as can be determined, resinuous imides of terpene-mono anhydride adducts and diamines yielding terpene-imide-imide-terpene configuration are not known. If the latter can be attained, such would amount to a substantial advance in the art.

It has been unexpectedly found that soluble, resinous terpene maleimides can be obtained by reacting terpene maleic anhydride adducts containing not less than 85% mono-adducts with a diamine. The resultant terpene maleimide having primarily a terpene-imide-imide-terpene configuration finds utility, particularly, as a tackifier for polar elastomers.

According to the invention in one aspect there is provided a resinous terpene maleimide of primarily terpene-imide-imide-terpene configuration having a molecular weight in the range from 500 to 600 and a softening point in the range from 70" to llO"C and formed by reaction between an adduct of a non-conjugated terpene and maleic acid anhydride which contains at least 85% mon-adduct and not more than 15% di-adduct, with a stoichiometric amount of an aliphatic or aromatic diamine at temperatures of from 140-240"C.

By the term resinous", as that term is employed herein, is meant that the subject maleimides when added to an elastomeric composition impart permanent tackiness thereto as can be appreciated from the illustrative examples which are included herein.

The present invention also provides a process for preparing a terpene maleimide resin which comprises: reacting at temperatures of from 140"C. to 200"C. substantially equimolar amounts of (a) a non-conjugated terpene of mixtures thereof an (b) maleic acid anhydride in the presence of from 0.05% to 0.15% iodine based on the weight of the terpene, recovering a mixture of not less than 85% mono-adduct and not more than 15% di-adduct of terpene maleic adducts, further reacting said adduct mixture with stoichiometric amounts of an aliphatic or aromatic diamine at temperatures of from 140"C to 240"C and recovering terpene maleimide having an average molecular weight of from 500 to 600 and a softening point of from 70"C. to llO"C.

The choice of the temperature and iodine range results in the economic production of the mono-adduct with a controllably small percentage of di-adduct. Control of the composition of the adduct allows production of the desired resinous imide derivative.

Additionally, the terpene-maleic anhydride adduct, in spite of preparation from widely different terpene feed stocks, shows essentially the same gel-phase chromatographic size distribution. The chosen iodine level and temperature apparently establish approximately the same equilibrium mixture of conjugated terpenes which in turn react with the maleic anhydride to form their adducts of uniform composition.

Exemplary of the non-conjugated terpenes which can be used are limonene, terpinolene, 1,4-para-methadiene, terpineol, 1,4-cineole, or 1,8-cineole, or mixtures of the same.

Exemplary of the diamines which can be employed are trimethylene diamine, ethylene diamine, phenylene diamine, toluene diamine, as well as diethylene triamine.

The invention is illustrated by the Examples which follow. Unless otherwise stated, the parts are by weight.

Example 1 A small amount of terpene maleic anhydride adduct (previously prepared) was dissolved in a small amount of xylene and added to the reactor. This mix is used to provide heat transfer for starting the continuous addition o the other ingredients. This mix is heated to 200"C. effecting reflux and is followed by addition of iodine (1.1 parts to the kettle). Over a two-hour period 906 parts of limonene and 588 parts of maleic anhydride and xylene are added continuously. The xylene is added at a metered rate such that the kettle temperature remains at 2000C. and some reflux is maintained at all times. The reaction between the terpene and the maleic anhydride is exothermic and the heat of the reaction is dissipated at the condenser. The condensate goes through a separator and then is returned to the top of the condenser. Some water may be removed during this reaction if the maleic anhydride contains some maleic acid or if there are any cineoles in the terpene fraction these are dehydrated to dipentene in the presence of the iodine catalyst. The xylene reflux serves to dissipate the heat of the reaction and also flushes any maleic anhydride vapors or sublimates back to the reactor. After the ingredients are added, the kettle is held for an additional two hours at 200"C.

Heat is withdrawn and the mix cooled to 1000C.

There is recovered a yield of 1360 parts (91% yield) of a maleic anhydride terpene adduct mixture as a pale yellow liquid. Analysis of this adduct by gel permeation chromatography showed 95% mono-adduct and about 5% of di-adduct.

The imide product having a terpene-imide-imide-terpene type configuration, is next prepared by reacting 588 parts of the adduct mixture with 77 parts of ethylene diamine in 200 parts (by volume) of xylene. The ethylene diamine is slowly added to the adduct at 140"C. an any product water is removed as an azeotrope. When the addition of the diamine is complete, the kettle temperature is slowly raised to 240"C. to facilitate removal of water and solvent. After reaching 240"C. kettle temperature, the product is vacuum steam stripped at 50 mm pressure for 3 hours to remove any volatile oils. The stripped resin is then cooled and drummed or alternatively flaked and bagged.

The product which is a resinous terpene maleimide possesses the following properties: Softening Point ("C.) 88 Acid Number 1 Number Average Molecular Weight 533 Cloud Point* C. 159 *Cloud point is determined by admixing 2.5 parts of resultant resin with 10 parts of a 1:1 mixture of "Elvax" 150 (33% vinyl acetate - ethylene copolymer) and Ceratak (microcrystalline wax m.p. 165"F.), melting to a clear melt, and allowing the melt to cool slowly until it clouds - "elvax" is a Registered Trade Mark.

Example 2 Example 1 was repeated except 147 parts of m-phenylene diamine were used in place of ethylene diamine, and 5 parts of p-toluene sulfonic acid were added when the temperature reached 200"C.

S.P. - 129"C.

Acid No. - 3 Cloud Point* - > 300 C.

*determined as in Example 1 Example 3 Example 1 was repeated except 91 parts 2,4-diamino-toluene were used with 33 parts ethylene diamine in place of 77 parts of ethylenediamine.

S.P. - 114"C.

Acid No. - 1 Cloud Point* - 258"C.

*determined as in Example 1 Example 4 The process of Example 1 is repeated in every detail except that the terpene fraction therein is substituted by 930 parts of a terpene fraction comprising about 40% terpinolene, 25% dipentene, 30% 1,4-cineole and the balance being terpene hydrocarbons and terpene alcohols.

Example 5 The process of Example 1 is repeated in every detail except that 97% limonene is substituted for the terpene fraction mixture therein. There is obtained a limonene maleic anhydride adduct in a yield of about 92% having more than 95% mono-adduct in said mixture and being a light yellow liquid.

Example 6 The terpene imides as prepared by the procedure of Examples 1 and 2 are compounded with additives into three hot melt formulations utilizing "Elvax" 250 (28% vinyl acetate 72% ethylene copolymer); "Elvax" 150 (33% vinyl acetate - 67% ethylene copolymer); "Elvax" 40 (40% vinyl acetate - 60% ethylene copolymer); "Shell" wax 300 (paraffin wax mp = 159"F - "Shell" is a Registered Trade Mark) The formulations are tubularized below: TABLE I Formulations Compositions A B X Parts by Parts by Parts by Wt. Wt. Wt.

Terpene Imide of Ex. 1 40 -- 40 Terpene Imide of Ex. 2 -- 40 - "Elvax" 250 40 -- - "Elvax" 150 -- 40 - "Elvax" 40 -- -- 40 "Shell" wax 300 20 20 20 The formulas (A, B, and C above) are employed at a coating of one (1) of a plurality of substrates (i.e., substrates 1 below) which are then sealed to a second substrate 2 at 2250F. for a 0.3 sec. under ten pounds per square inch (10 psi) pressure. The peel strength is next determined by "Instron" (Registered Trade Mark) testing in ounces per inch according to pressure sensitive tape Council method (PSTC - 1). The results are tabularized below: TABLE II Substrates Peel Strength (oz/in) imparted by Formulation (Table I) 1 2 A B C Kraft Paper Kraft Paper 7 25 16 Kraft Paper Aluminum 12 32 Kraft Paper Polyethyleneterephalate 4 17 26 Kraft Paper Regenerated Cellulose 31 16 10 Kraft Paper Polypropylene 3 24 Polyethyleneterephalate Aluminum 11 42 52 Regenerated Cellulose Aluminum 12 63 44 Preferably, the low-molecular weight terpene imide resins in accordance with the present invention will possess the following overall properties: Softening Point, "C 70-110 Color (Gardener, 50/50 Toluene) 1-4 Acid Number 1-10 Molecular Weight 500-600 Appearance Clear, light-amber resin Cloud Point* "C. 140-200 Specific Gravity, 25"/25"C. 1.152 Toluene Insolubles, % 0.018 *Cloud Point as determined in Example 1 above.

The terpene imide resins are soluble in aromatic hydrocarbons, chlorinated hydrocarbons, esters, ketones, ethers, and alcohols, but insoluble in aliphatic hydrocarbons. Due to their molecular weight and compatibility as shown by their cloud point, the resins of the present invention find utility as tackifiers in polar formulations.

Claims (11)

WHAT WE CLAIM IS:

1. A process for preparing a terpene maleimide resin which comprises: reacting at temperatures of from 140 C. to 200"C substantially equimolar amounts of (a) a non-conjugated terpene or mixtures thereof and (b) maleic acid anhydride in the presence of from 0.05% to 0.15% iodine based on the weight of the terpene, recovering a mixture of not less than 85% mono-adduct and not more than 15% di-adduct of terpene maleic adducts, further reacting said adduct mixture with stoichiometric amounts of an aliphatic or aromatic diamine at temperatures of from 140"C to 240"C and recovering terpene maleimide having an average molecular weight of from 500 to 600 and a softening point of from 70"C to 110 C.

2. A process according to Claim 1, wherein the terpene is terpinolene.

3. A process according to Claim 1, wherein the terpene mixture comprises terpinolene and cineole.

4. A process according to Claim 1, wherein the terpene is limonene.

5. A process according to any preceding claim, wherein the iodine added is 0.12%, based on the weight of the terpene reactant.

6. A process according to any preceding claim wherein the diamine is ethylene diamine.

7. A process according to any one of claims 1-5, wherein the diamine is trimethylene diamine.

8. A resinous terpene maleimide of primarily terpene-imide-imide terpene configuration having an average molecular weight in the range from 500 to 600 and a softening point in the range from 70C to 110 C and formed by reaction between an adduct of a non-conjugated terpene and maleic acid anhydride which contains at least 85% monoadduct and not more than 15% di-adduct, with a stoichiometric amount of an aliphatic or aromatic diamine at temperatures of from 140-240"C.

9. A terpene maleimide accordng to Claim 8 and substantially as described in any one of Examples 1-5 herein.

10. A process for preparing a terpene maleimide resin, according to Claim 1 and substantially as described in any one of Examples 1-5 herein.

11. A terpene maleimide resin prepared by a process according to any one of Claims 1-7 or 10.