JPS5917732B2 - Metal-amine complex salt accelerator for curing polyester resins - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the curing of unsaturated polyester resins blended with vinyl monomers, and more particularly to the curing of unsaturated polyester resins blended with vinyl monomers while preserving desirable long shelf life during storage of premixed products at ambient room temperature. It relates to promoting or promoting cross-bonding between such polyesters and vinyl monomers.

Copolymerization of unsaturated polyester resins with vinyl monomers in the presence of free radical generating compounds such as organic peroxides is well known in the art.

Among the vinyl monomers that have been suggested or used are methyl methacrylate, vinyl chloride, vinyl acetate, vinyltoluene, and styrene, the last of which is highly desirable. Unsaturated polyesters combine one or more dihydric alcohols with unsaturated dibasic compounds such as cis-butenedionic acid (maleic acid) or its anhydride, or trans-butenedionic acid (fumaric acid) or mixtures thereof. It is obtained by reaction with a carboxylic acid, optionally in the presence of a saturated dicarboxylic acid such as phosphoric acid or isophthalic acid. Monomer is 30-70% by weight of the mixture with unsaturated polyester
May include. A wide variety of organic peroxide catalysts, referred to as "initiators", are known and have been widely used commercially for the polymerization of unsaturated polyesters and copolymerizations with vinyl monomers.

These functions via the decomposition of peroxide bonds form highly active free radicals that initiate polymerization reactions.
These peroxide initiators initially vary widely with respect to the temperature at which they undergo cleavage and with respect to their rate of decomposition, providing free radicals at any given temperature. Accelerators, also referred to as cocatalysts, are often used to increase the rate of free radical formation from peroxides in conjunction with formulations to be cured at low temperatures, particularly at or near room temperature. Among the more frequently suggested and more widely used promoters are dimethylaniline and cobalt naphthenate.

Cobalt naphthenate and other metal soaps are commonly proposed for use with ketone peroxides in cold cure formulations. Dimethylaniline is known to promote benzoyl peroxide at room to moderate temperatures; cobalt naphthenate does not. On the other hand, none of these cocatalysts has any effect on tert-butyl peroctoate at room temperature. The use of certain cocatalysts can reduce the gelation and curing times at elevated temperatures of polyester systems using tert-butyl peroctoate, and dimethylaniline is useful for this purpose. more effective than The widespread use of unsaturated polyester-styrene copolymer systems is in sheet molding compounds (SM
C) and bulk molding compound (BMC).
These systems decompose at higher temperatures than general purpose resins and
Furthermore, initiators are used which require storage stability for longer periods. Although the gel and cure times of such glass fiber reinforced plastics can be accelerated by the inclusion of effective cocatalysts, these accelerators generally have adverse effects on the required storage stability of uncured systems. give. Additionally, most BMC and SMC formulations also include thermoplastic resins, such as acrylic polymers, to reduce shrinkage upon curing. These acrylic polymers are incompatible with unsaturated polyesters and the phases often give rise to an unpleasant mottled surface of the cured product rapidly after mixing, especially when the cure is accelerated. Representative formulations for bulk molding and sheet molding mixtures are described below.

Among the preferred peroxide catalysts used are tert-butyl perbenzoate and/or tert-butyl peroctoate, and sometimes one or both of these and 11-1, such as benzoyl peroxide. There is a combination with an initiator.

Depending in part on the specificity of the catalyst or catalyst mixture used, these range from about 0.5 to 2, depending on the weight of resin in the formulation.
Consists of 0%. Thickeners generally represent about 2-3% by weight of the resin component. Lubricants such as zinc stearate (1-2%) are commonly included in BMC and SMC compositions. An earlier patent application filed by the applicant describes a novel polymerizable coordination complex salt of triethylenediamine (TEDA) or its congener with a cobalt salt,
It has been described as a promoter or cocatalyst for use in peroxide-initiated copolymerizations of vinyl monomer trees.

These novel metal amine complexes are effective in reducing the gelation and curing times of these resins while retaining sufficient stability to store the resin compositions at ambient temperatures for the desired period of time. The activity of the cobalt triethylene diamine complex salts of our earlier application can be moderated as desired by the inclusion of such complex salts of manganese.

The moderating activity of such cocatalysts is particularly important for bulk molding compounds (
This is desirable in the handling of sheet molding compounds (BMC) and sheet molding compounds (SMC). Rapid curing of the polyester in a die mold compatible with high temperatures is desirable, commensurate with adequate pour time, but if such pour time is too short, the compound may gel prematurely before the mold is compacted. shows. This is displayed as flow symbols and/or incomplete molding. In some cases, too fast gelation may cause BM to be wisely removed.
C or SMC evenly distributed over many molds, or
or by keeping the female part of the mold cooler than the male part. However, when the mold is large and deep, these compensation benefits are not reliable in overcoming the problem of premature gel formation. Utilizing the triethylenediamine compound according to the present invention and a mild cocatalyst comprising a metal coordination complex with cobalt and manganese, the problem of premature gelation is eliminated with only a small sacrifice in curing time and even more. Desirable long shelf life benefits are retained or improved.

The invention will now be described in more detail.

Coordination complex salts with cobalt and manganese can be prepared by dissolving the triethylenediamine compound in glycol or other suitable solvent, such as styrene.

The cobalt and manganese salts can similarly be dissolved by dissolving them together or separately in a common solvent and then mixing the solutions. Dissolution of these salts as well as of the triethylenediamine compound occurs at or above room temperature (
(up to 100°C, or higher if desired). The salt solution or solutions are mixed with the triethylenediamine compound solution under stirring, optionally with moderate stirring, until a smooth homogeneous liquid mixture is obtained. Stable complex salts are formed upon cooling to room temperature. Stable metal complexes of triethylenediamine with cobalt and manganese salts are formed over a wide range of molar ratios of metal to heterocyclic base, but contain at least 1 mole of triethylenediamine compound per mole of metal. It has been discovered that this provides optimal shelf life for accelerated polyester resin systems.

The metal amine complex should contain at least 5' moles of each cobalt and manganese component per mole of triethylenediamine compound. That is, the atomic ratio of CO/Mn in the complex salt is preferably within the range of 3:1 to 1:3.
Preferred complex salts are those in which the molar amount of cobalt salt is equal to the amount of manganese salt, or are prepared from an excess of cobalt and manganese divalent chloride or acetate. It is best if at least one, preferably two of the salts are used in hydrate form. Acetate salts are preferred over chlorides in many formulations because the former more readily form stable solution complexes. The preparation of stable coordination complex salts with cobalt and manganese from triethylenediamine is illustrated in Example 1 below using each % mole of metal salt per mole of triethylenediamine.

Example 1 Glycerol and dipropylene glycol were mixed and stirred at room temperature until the cobalt and manganese salts were dissolved.

The triethylene diamine solution was then added and stirring continued to obtain a smooth homogeneous mixture. Diaza Bicyclo (D
Triethylenediamine (TEDA), also known as (2.2.2)octane, is manufactured by AirPrOducts.
and Chemicals, Inc.

(Trademark DABCO) The manufacturing method is US Patent No. 2937
It is described in No. 176. The preparation of several congeners of triethylenediamine, including the 2-methyl and 2.4 dimethyl compounds, is described in U.S. Pat. No. 3,167,518.

TED in advance for use in polyester resin formulations
There is no need to prepare a metal complex salt of the A compound.

The solutions or solutions of metal salts and TEDA compounds can be mixed separately in the desired proportions during resin formulation, with the metal complex being at least partially formed in situ during formulation and standing of the resin mixture. . The TEDA monometal complex salt or the mixture of components in such a complex salt ranges from about 0.2% to about 0.9%.
When such cocatalysts are used, even amounts of less than 1% by resin weight are effective in promoting curing and crosslinking of unsaturated polyester resin mixtures.

It is unlikely that higher amounts would have the opposite effect. Typical compositions for bulk or sheet molding include the following. These materials are compounded in a commercial secondary to produce sufficient homogeneity.

The blended charge (premix) is then aged for several days, cut into convenient size Z sizes, shaped and heated to 250-325'F (approximately 121-325'F) for a short time, usually 1-3 minutes. 163℃
) was cured. TEDA with or without manganese added
/cobalt complex salts in various combinations and in different amounts] on the basic resin mixture (net), i.e. with respect to the filler,
Tests were conducted without thickeners, lubricants and glass reinforcement.

Gelation time, curing rate, and maximum heat generation of the composition are shown in the exotherm curve (Preliminary print for the 24th Annual Technical Conference, 1969, Linehosdrop**Lastics/Compositions Division,
It was determined by the standard PROT test method using the SPI method for defining plastics industry associations. The table below was conducted to determine the effect on cure rate of cobalt and manganese salts used individually compared to combined use.

The base resin formulation included the following: The reported shelf life was determined by filling and storing 100 y of each composition in a capped bottle at ambient room temperature immediately after formulation.

The bottle was inverted at least once a day until gelation occurred, as evidence of failure of the composition to flow. The number of days to gelation was recorded as shelf life. Paraflex P-
19C is a mixture of about 60 parts of Paraflex P34O and about 40 parts of Paraflex P-681.

P-340 is a glycol (7.3 moles of propylene vs. 0
．． A styrene solution of a highly reactive polyester resin containing a small amount of free butenedioic acid made from 7 moles of ethylene) and cis and trans butenedioic acid. P-681 resin is a styrene solution of polymethyl methacrylate. Test 1 results are reported in Table 1 below.

Manganese salts used alone, as distinguished from the cobalt salts above by the above tests, do not appear to promote curing of these resin formulations.

The promoting effect of the cobalt salt is weakened when the two are used together. In the tests recorded in the table below, the resin mixture used was 60 parts of a styrene solution of Paraflex P-34 mixed with polymethyl methacrylate (Paraflex P-701).
) along with 40 parts of styrene solution.

These tests were conducted to determine the cure rate at 300'F of metal complexes formed from TEDA with cobalt and manganese salts. From the data reported in the table, it is observed that gelation time increases with increasing Mn concentration.

Tests similar to those reported in the table above were conducted on other commercial resin mixtures containing styrenic monomers containing acrylic modified polyesters. The results of these tests are reported in the table below. The advantageous results of using both cobalt and manganese in the triethylenediamine complex are best appreciated by reference to the accompanying drawings which show graphs of the exothermic reactions below, plotting temperature rise against time in minutes.

FIG. 1 shows a family of curves comparing a resin composition promoted by a cobalt TEDA complex to a control composition containing no cocatalyst. FIG. 2 shows a series of curves comparing a cobalt-manganese-TEDA complex promoted resin composition to a control composition containing no cocatalyst. The test formulation had the following composition: Curves 2 and 4 in Figure 1 and curve 6 in Figure 2
and 7, it is clear that the steep climb of the CO-TEDA-promoted system is in contrast to the CO-Mn-TEDA-promoted system, with the temperature increase being much more gradual in the latter case. , accelerated curing occurs with one kick-off of the initiator (
KiCk-0ff) closely follows the progress of unaccelerated curing until t1 occurs.

The CO-Mn-TEDA cocatalyst thus provides a desirable delay period that avoids premature gelation problems. The use of moderate metal complex salts of TEDA that coordinate both cobalt and manganese within the complex is particularly advantageous in aiding or accelerating the curing of unsaturated polyester resin systems of the type used in SMC and BMC formulations. The use of such co-catalysts is not limited to this, nor is it limited to resin systems that also include thermoplastics such as acrylic polymers that reduce shrinkage upon curing.

Generally, the metal complex salt cocatalyst of the present invention is a peroxide or other free radical consisting of (1) a dihydric alcohol, an α/β ethylenically unsaturated dicarboxylic acid, and (2) an ethylenically unsaturated reactive monomer. Can be used in starting resin systems. Embodiment 1 A mixture according to claim 1, wherein the cobalt and manganese salts are present in a molar ratio ranging from 1:3 to 3:1.

Embodiment 2 A mixture according to claim 1, wherein the cocatalyst is a preformed metal complex consisting of at least 1 mole of triethylenediamine and 1.5 moles of each of cobalt and manganese salts.

Embodiment 3 A mixture according to embodiment 1, wherein the cobalt and manganese salts include both metals in divalent form.

Embodiment 4 A mixture according to embodiment 2, wherein the cobalt and manganese salts are in the form of their hydrated acetate salts.

Embodiment 5 A mixture according to embodiment 1, wherein said cobalt and manganese salts are in hydrated form.

Embodiment 6. A mixture according to claim 1, wherein the co-catalyst is obtained by mixing a solution of triethylenediamine with a solution containing salts of cobalt and manganese.

Embodiment 7 The mixture further comprises a thermoplastic resin, and the ethylenically unsaturated reactive monomer is a reactive vinyl monomer,
The cocatalyst is a metal coordination complex salt formed from triethylenediamine and an organic solution of divalent metal salts of cobalt and manganese, and the molar ratio of triethylenediamine to metal in the complex salt is at least 1:1 in bulk or sheet. A mixture according to claim 1 for molding.

Embodiment 8 A mixture according to embodiment 6, wherein the organic peroxide comprises tert-butyl perbenzoate.

Embodiment 9 The polyester is a polyester of a dihydric alcohol and at least one butenedionic acid, the unsaturated monomer is styrene, and the cocatalyst for the peroxide comprises cobalt and manganese salts together with a triethylenediamine compound. 3. Formed by dissolving in an organic solvent, said triethylenediamine being present in an amount at least equimolar to said metal salt, and said composition further comprising polymethyl methacrylate. The curable polyester composition described in .

Embodiment 10 The composition of claim 3, wherein the organic solvent comprises dipropylene glycol.

Embodiment 11 The composition according to claim 3, wherein the organic solvent comprises dipropylene glycol and glycerol.

Embodiment 12 The promoter comprises 1 to 3 parts of cobalt salt and manganese salt to 3 to 3 parts.
4. A composition according to claim 3 comprising in one part.

Embodiment 13 A mixture according to claim 1, wherein the triethylenediamine compound in coordinated free form is present in at least an equimolar amount with respect to the cobalt and manganese salts.

[Brief explanation of drawings]

The attached drawing is a graph showing the relationship between the temperature (T) at which the exothermic reaction occurs and the elapsed time (minutes) for the purpose of showing the effect of accelerating the curing of polyester resin by the metal-amine complex salt. Figure 2 shows a family of curves comparing a resin composition promoted by a cobalt-manganese-TEDA complex to a control composition without a cocatalyst; Figure 3 shows a family of curves comparing compositions.

Claims (1)

[Scope of Claims] 1 (a) an unsaturated polyester of a dihydric alcohol and an α-β ethylenically unsaturated dicarboxylic acid, (b) an ethylenically unsaturated reactive monomer, and (c) a free radical-initiated organic A curable polyester mixture comprising a peroxide and (d) a cocatalyst comprising a triethylenediamine compound present at least in part as a metal coordination complex with cobalt and manganese salts. 2. The polyester is an ester of at least one dihydric alcohol and butyl dionic acid, the unsaturated monomer is styrene, and the cocatalyst is a metal coordination complex salt of triethylenediamine and salts of cobalt and manganese. , the complex salt has an amount of the triethylenediamine in at least an equimolar proportion to the metal salt, and the composition further includes a thermoplastic acrylic resin, a thickening agent, and a glass reinforcement fiber. Claim 1
The curable polyester composition described in Section 1.