JP2023502105A - Curable composition - Google Patents

Abstract

Use of an inorganic salt (a), the viscosity reducing effect of an acid-functional additive (b) in a composition comprising a polyester resin (c) and an inorganic thickener (d) different from the inorganic salt (a) use of an inorganic salt (a) comprising anions selected from halogen ions, nitrate ions, phosphate ions, sulfate ions and mixtures thereof for compensating for

Description

The present invention relates to the use of inorganic salts to compensate for the viscosity-lowering effect of acid-functional additives in compositions comprising polyester resins and inorganic thickeners. Furthermore, the present invention relates to methods of preparing said compositions and three-dimensional articles.

Thermosetting resins such as unsaturated polyester resins are commonly used in a wide variety of products such as foundry materials and fiber reinforced materials. Unsaturated polyester resins are usually condensation products of dicarboxylic acids or anhydrides and difunctional alcohols to provide the backbone unsaturation necessary for cross-linking. Curing of the resin occurs during the cross-linking process. This process results in an increase in viscosity, resulting in hardening (curing) of the resin. Also, an auxiliary component may be added to improve the workability of the resin. One commonly used auxiliary ingredient is an additive, such as a processing additive, which enhances the resin manufacturing process in various ways and is essential in the manufacture of thermoset resins. However, the thickening of curing systems such as polyester resins is affected by acids. Therefore, the use of these additives (which are generally acidic additives) can, under certain conditions, lead to retardation of the thickening time of the resin. The more acid groups added, the longer the time required for thickening. Therefore, there is a continuing need to compensate for the slow thickening time and adjust the curing process accordingly.

US Pat. No. 3,538,188 deals with thickeners for polyester resins. A mixture of inorganic lithium and magnesium salts is added to the unsaturated polyester resin to increase the viscosity of the resin. The mixture slows the viscosity increase for the first 24-48 hours and then causes a rapid high viscosity increase. However, it does not address the addition of additives nor their respective effects on the resin.

US2007/00041A1 deals with thickeners for polyester resins used in Cured-In-Place-Pipe open molding processes. Activators including magnesium oxide and calcium oxide are used to increase the viscosity of polyester resins. This document also does not relate to the use of additives in such resin systems and therefore does not aim to reduce their potential side effects.

It is therefore an object of the present invention to overcome the drawbacks of the prior art and to provide compounds that produce reduced thickening times for workability. Another object is to provide a compound that must be used only in small amounts, is inexpensive, easy to use, and increases the viscosity of the resin.

Surprisingly it has been found that the use according to the invention meets the above requirements.

The present invention provides a composition comprising a polyester resin (c) and an inorganic thickener (d) different from the inorganic salt (a), to compensate for the viscosity-reducing effect of the acid-functional additive (b), It relates to the use of inorganic salts (a) containing anions selected from halide ions, nitrate ions, phosphate ions, sulphate ions and mixtures thereof.

In a further embodiment, the present invention provides for increasing the viscosity of a composition comprising an acid-functional additive (b), a polyester resin (c), and an inorganic thickener (d) different from the inorganic salt (a). of inorganic salts (a) comprising anions selected from halogen ions, nitrate ions, phosphate ions, sulfate ions and mixtures thereof.

Preferably, the inorganic salt (a) is an alkali metal or alkaline earth metal salt. Alkali metals comprise group 1 of the periodic table, while group 2 represents the alkaline earth metals. Examples of such alkali metals or alkaline earth metals are lithium, sodium, potassium, rubidium, beryllium, magnesium, calcium and strontium. Inorganic salt (a) is preferably a salt selected from the group of lithium, sodium, potassium, magnesium and calcium. More preferably inorganic salt (a) is a salt selected from the group of sodium, potassium and calcium. Even more preferably, inorganic salt (a) comprises a salt of calcium.

Inorganic salt (a) comprises anions selected from halides, nitrates, phosphates, sulfates, and mixtures thereof.

A halogen ion is a negatively charged halogen atom. Halogen anions are fluorine (F ^- ), chloride (Cl ^- ), bromide (Br ^- ), iodine (I ^- ), and astatine (At ^- ). Preferably chloride, bromide or iodine ions are used. More preferably, inorganic salt (a) contains a chloride anion. Nitrate ions are ions with the molecular formula NO ₃ ^- , phosphate ions are ions with the molecular formula (PO ₄ ) ^3- , and sulfate ions have the molecular formula SO ₂ ^-4 . The inorganic salt (a) preferably contains an anion selected from sulfate ions and halogen ions. More preferably, the inorganic salt (a) contains halogen ions. Preferably, inorganic salt (a) comprises calcium chloride. In another embodiment, inorganic salt (a) consists of calcium chloride.

The composition comprises an acid-functional additive (b). Acid-functional additives are additives that have acid functionality and exhibit acid functionality. Salts of acids do not represent acid-functional additives according to the present invention. Acid-functional additive (b) suitably comprises at least one of carboxylic acid functionality, acid phosphate ester groups, phosphate groups and combinations thereof. More preferably, the acid-functional additive (b) typically comprises polyethers, polyesters, polyurethanes, epoxy-amine-adducts, linear or branched C10-C100 alkyl chains, or combinations thereof. contains a first portion containing and a second portion containing an acid functional group. In a preferred embodiment of the invention, the second portion consists of acid functionality. In one preferred embodiment, the acid functionality is a phosphate ester group. Typically, the additives of such embodiments are suitable as wetting agents and dispersing agents. In another preferred embodiment, the acid functionality is a carboxylic acid group. Additives of such embodiments are typically suitable as processing agents and release agents.

Generally, the acid-functional additive (b) has an acid number in the range of 10-250 mg KOH/g. The acid-functional additive (b) preferably has an acid value in the range of 10-200 mg, more preferably in the range of 10-150 mg. The acid number may be calculated based on the raw materials used or determined by titration. Acid number is the amount of KOH (mg) required to neutralize 1 g of material. The acid number was determined according to DIN EN ISO 2114 by neutralization reaction with 0.1N KOH in ethanol.

The acid-functional additive (b) preferably has a number average molecular weight of 300 to 15000 g/mol. More preferably, the acid-functional additive (b) has a number average molecular weight of 300 to 10000 g/mol, more preferably 300 to 7000 g/mol. Most preferably, the acid-functional additive (b) has a number average molecular weight of 300-5000 g/mol. The number average molecular weight was determined according to DIN 55672 part 2 (2016) by gel permeation chromatography (eluent: lithium bromide solution in dimethylacetamide (content 5 g/l), standard: polymethyl methacrylate, column temperature: 50 °C). Number average molecular weight can also be determined by calculation. Additionally, number average molecular weights of small molecules up to 1000 g/mol can be determined by other methods such as mass spectroscopy or nuclear magnetic resonance spectroscopy.

Inorganic salt (a) is used to compensate for the viscosity-lowering effect of acid-functional additive (b) in compositions comprising polyester resin (c) and inorganic thickener (d). Acid-functional additives (b) can lead to an increase in the time required to thicken the polyester resin and significantly reduce the final level of viscosity achievable. To counteract this undesirable effect, inorganic salts (a) are added, which lead to accelerated thickening. Compensation of the viscosity reducing effect in the context of the present invention means that the undesirable effects of increasing thickening time and reducing thickening behavior are at least partially offset. The addition of the inorganic salt (a) ultimately reduces the thickening time even further compared to the polyester resin (c) without the acid functional additive (b) and the inorganic salt (a), partially can be shortened or accurately compensated. That is, it at least results in an increase in the viscosity of the polyester resin (c) by compensating for the viscosity-reducing effect.

Preferably, polyester resin (c) is an unsaturated polyester resin. Additionally, the composition preferably comprises an ethylenically unsaturated polymerizable monomer. Polyester resins can be any known in the art that crosslink during the curing process. Curing is a chemical process that results in strengthening or hardening of polymeric materials by cross-linking polymer chains. The curing process can be done by any method known in the art. Curing can be done at room temperature or at elevated temperature. Crosslinking can be accomplished by means of polyaddition, polycondensation, or polymerization reactions. Preferred curing processes are selected from radical or ionic polymerization reactions and polyaddition reactions.

Unsaturated polyester resins are resin systems that cure via radical chain reactions of carbon-carbon double bonds. They suitably comprise monomers such as unsaturated compounds to which one or more ethylenically unsaturated groups, preferably vinyl, substituted vinyl, allyl, (meth)acrylate and (meth)acrylamide groups are attached. Unsaturated polyester resins may be any known in the prior art; unsaturated polyester resins also include vinyl ester resins (preferably obtainable by reaction of epoxy resins with unsaturated monocarboxylic acids). Suitable examples are polyesters of dienes such as dicyclopentadiene (DCPD resins), as well as diols and dicarboxylic acids having a major amount of olefinic unsaturation, preferably from 10 to 75 olefinic groups per 100 ester groups. and polyester. Typical diols are ethylene glycol and propylene glycol. Typical unsaturated acids include maleic acid, fumaric acid, itaconic acid, and phthalic acid, which can also be incorporated into polyester resins starting from anhydrides, esters or halides of these acids. Curing of the unsaturated polyester resin is preferably carried out in the presence of a monomer. Preferably, the monomer is an ethylenically unsaturated polymerizable monomer.

Any ethylenically unsaturated monomers and oligomers conventionally used in unsaturated polyester resins can be used and are capable of cross-linking with the unsaturated polyester. Ethylenically unsaturated polymerizable monomers are preferably selected from styrene and substituted styrenes (such as α-methylstyrene), allyls, allylbenzenes, (meth)acrylates, (meth)acrylamides, and olefinic compounds.

Optionally, these systems further comprise crosslinkers such as di(meth)acrylates, di(meth)acrylamides, divinylbenzene, tri(meth)acrylates, tetra(meth)acrylates, and the like. Unsaturated polyester resin systems are preferably used in the presence of initiators (such as peroxides or azo initiators), optionally with accelerators such as tertiary amines or cobalt compounds (e.g. cobalt octoate or cobalt naphthenate). can be cured in the presence of The curing process can be initiated at ambient temperature or at elevated temperature, optionally by applying pressure to the system, such as in a mold.

Inorganic thickener (d) is different from inorganic salt (a). Suitably, the inorganic thickener (d) is selected from basic metal oxides, metal hydroxides, and combinations thereof. Basic metal oxides are generally oxides with a pH greater than 7. They are usually formed by reacting oxygen with metals, especially alkali metals and alkaline earth metals. Suitable examples of basic metal oxides are MgO, CaO, ZnO, BaO. Metal hydroxides are hydroxides of metals and are generally known to be strong bases with a pH greater than 7. Many metal hydroxides are composed of hydroxide ions and ions of specific metals that make them up. Suitable examples of metal hydroxides are Ca(OH) ₂ , Mg(OH) ₂ , Zn(OH) ₂ .

Inorganic thickeners (d) are preferably selected from alkali metals, alkaline earth metals and combinations thereof. Preferably, inorganic thickener (d) comprises magnesium oxide. In a further embodiment, inorganic thickener (d) comprises at least 50% by weight magnesium oxide, calculated on the weight of inorganic thickener (d). In yet another embodiment, the inorganic thickener (d) consists of magnesium oxide.

The invention further relates to compositions comprising:
an inorganic salt (a) comprising anions selected from halide ions, nitrate ions, phosphate ions, sulfate ions and mixtures thereof;
an acid-functional additive (b),
a polyester resin (c), and an inorganic thickener (d) different from the inorganic salt (a).

In a preferred embodiment, the composition comprises (weight percentages are calculated relative to the total weight of the composition):
0.0001 to 1.0000% by weight of an inorganic salt (a) comprising anions selected from halogen ions, nitrate ions, phosphate ions, sulfate ions and mixtures thereof;
0.0100 to 5.0000% by weight of an acid-functional additive (b);
10.0000 to 50.0000% by weight of polyester resin (c),
0.1000 to 1.0000% by weight of an inorganic thickener (d), different from the inorganic salt (a);
43.0000-89.8899% by weight of components different from (a)-(d).

Additionally, the composition may generally include solid particles selected from fillers, pigments, fibers, flame retardants (eg, Al(OH) ₃ ), and combinations thereof. Solid particles are different from inorganic thickeners (d) and inorganic salts (a).

Suitable fillers are, for example, the customary pulverulent or granular fillers, hydraulic silicates, chalk, kaolin, dolomite, barite, cement, talc, diatomaceous earth, wood flour, wood chips, clay, talc, Silica powder, glass powder, glass beads, microcellulose, silica sand, river sand, marble waste, crushed stone, or any combination thereof may be included.

Fiber reinforced composites contain fibers embedded in a polymer matrix. The polymer matrix acts as a binder between the fibers. Fibers generally improve the mechanical properties of the composite compared to the matrix polymer alone. Fibers may be inorganic or organic. Suitable fibers are glass fibres, carbon fibres, basalt and polymer fibres, line cellulose and fibers of polyethylene, polycarboxylic acid esters or polyamide resins. They can be in the form of staple fibers with a length of up to 5 cm, or in the form of ground fibers, but preferably long fibers as individual rovings, webs of parallel rovings, fiber mats, fiber webs, fiber fabrics or fiber knits. is in the form of They can generally be used up to 60% by weight, based on the total weight of the composition. Carbon fibers include amorphous carbon fibers and graphite fibers. Carbon fibers made from various starting materials, for example carbon fibers made from polyacrylonitrile, pitch or rayon, are likewise suitable. The carbon fibers may have undergone a chemical or mechanical surface pretreatment, for example with known sizing agents during fiber manufacture. Carbon fibers that have not undergone a specific pretreatment can be used as well. Depending on the intended end use, the carbon fibers may be present as filament fibers, staple fibers or chopped fibers. In some embodiments, the carbon fibers are present as woven or non-woven fabrics. In other embodiments, the carbon fibers are present as rovings.

All known types of pigments can be used in the composition according to the invention. Inorganic or organic pigments and mixtures thereof can preferably be used. Typically, organic pigments are colored pigments. It refers to colored materials made of organic compounds that have the properties of pigments. In some embodiments, inorganic and organic pigments may be used, preferably up to 30% by weight, based on the total weight of the composition.

Additionally, the present invention encompasses a method of providing a three-dimensional article comprising the steps of:
providing a composition of the invention;
shaping the composition into a desired three-dimensional shape; and curing the composition.

Examples of three-dimensional shaped parts are boats, tanks (e.g. for oil, water, chemicals), pipes and tubes (e.g. for drinking and drainage), wall cladding and exterior walls, caravans, bathroom and washroom interiors (e.g. sinks, bathtubs, shower trays), seats (e.g. for buses, trains, stadiums), parts for vehicles such as automobiles, trucks, tractors (e.g. radiator cowls, trunk lids, air deflectors, spoilers, fittings, roofs ), doors, window and casing frames, profiles, battery housings, blades, parts for wind power plants such as housings.

Suitably, the step of shaping the composition into the desired three-dimensional shape is carried out by introducing the composition into a mold.

Typical procedures are sheet molding compounding (SMC), bulk molding compounding (BMC), injection molding (RIM - resin infusion molding, RTM - resin transfer molding), compression molding, VARI (vacuum applied resin infusion), filament winding, Including pultrusion, and autoclave curing.

Additional components may be present in the composition, particularly such components typically used in the production of thermosets. Examples of such ingredients include UV stabilizers, mold release agents, and defoamers.

More preferably, the method comprises the step of impregnating the fibers with the composition according to the invention.

The present invention further relates to a method of controlling the viscosity of a composition comprising the steps of:
providing an inorganic salt (a) comprising anions selected from halide ions, nitrate ions, phosphate ions, sulfate ions, and mixtures thereof;
providing an acid-functional additive (b);
providing a polyester resin (c);
providing an inorganic thickener (d) different from the inorganic salt (a);
Mixing ingredients.

Mixing is the act of combining components and subjecting the combined components to shear forces. The step of mixing the ingredients can be carried out according to current processes known to those skilled in the art. This may include mixing by manual or motorized means, among others. Suitably the mixing step is carried out in an extruder.

General preparation of formulations:
The polyester resin, polystyrene solution, and additives are mixed together before all remaining ingredients such as fillers, pigments, peroxides, etc. are added. The entire formulation is then homogenized by manual mixing. The mixture is then stirred using a dissolver, TYPE Pendraulik 5HWM-FDe80N 12-2, fitted with a dissolver disc 40±10 mm under the following conditions: dispersing for 60 seconds±10 seconds at a speed of 930 rpm±50 rpm, Then disperse for another 120 seconds ± 10 seconds at a speed of 1865 rpm ± 125 rpm (peripheral speed 3.9 ± 0.3 m/s). The finished homogenized compound is transferred to an aluminum cup, closed and stored in a water bath at a temperature of 30°C ± 5°C for 30 minutes ± 5 minutes.

Viscosity is measured using a Brookfield DV II+-measuring instrument using a spindle (type of spindle for measurements listed in the corresponding results) at a rotational speed of 5 upm to 30 rpm. All amounts are in parts per hundred resin [phr].

Experiment I

Table 3 shows the time dependent viscosity profile of SMC Formulation 1 with additional additives. Addition of calcium chloride to the formulation improves the time dependent viscosity profile (formulations 2 and 3). Therefore, adding calcium chloride to SMC formulations not only increases the thickening time, but also increases the overall final viscosity of the formulation.

Experiment II

Table 5 shows the time dependent viscosity profile of Formulation 4 with insufficient viscosity increase. Adding 0.3 phr of calcium chloride (Formulation 5) to the formulation accelerates the thickening time and increases the final viscosity.

Experiment III-I/Experiment III-II

Tables 8 and 9 compare the effect of different inorganic salts added at different concentrations (formulations 7-12). As a standard control, a formulation without inorganic salts is shown (formulation 6). All additional inorganic salts used in Examples 7-12 ensured to overcome thickening inhibition and resulted in increased thickening time and increased final viscosity.

Claims (15)

Use of an inorganic salt (a) to reduce the viscosity of an acid-functional additive (b) in a composition comprising a polyester resin (c) and an inorganic thickener (d) different from said inorganic salt (a) Use of inorganic salts (a) containing anions selected from halogen ions, nitrate ions, phosphate ions, sulphate ions and mixtures thereof for compensating effects. Use according to claim 1, wherein the inorganic salt (a) is an alkali metal or alkaline earth metal salt. 3. Use according to claim 1 or 2, wherein said inorganic salt (a) is a salt selected from the group of lithium, sodium, potassium, magnesium and calcium. Use according to any one of claims 1 to 3, wherein said inorganic salt (a) comprises calcium chloride. 5. Any one of claims 1-4, wherein the acid-functional additive (b) comprises at least one of carboxylic acid functionality, acid phosphate ester groups, phosphate groups, and combinations thereof. Use as indicated. Use according to any one of the preceding claims, wherein said acid-functional additive (b) has an acid number in the range of 10-250 mg KOH/g. Use according to any one of claims 1 to 6, wherein the acid-functional additive (b) has a number average molecular weight of 300 to 15,000 g/mol. Use according to any one of the preceding claims, wherein the polyester resin (c) is an unsaturated polyester resin. Use according to any one of the preceding claims, wherein the composition comprises ethylenically unsaturated polymerizable monomers. Use according to any one of the preceding claims, wherein said inorganic thickener (d) is selected from alkali metals, alkaline earth metals and combinations thereof. Use according to any one of the preceding claims, wherein said inorganic thickener (d) is selected from basic metal oxides, metal hydroxides and combinations thereof. Use according to any one of the preceding claims, wherein said inorganic thickener (d) comprises magnesium oxide. A composition containing:
an inorganic salt (a) comprising anions selected from halide ions, nitrate ions, phosphate ions, sulfate ions and mixtures thereof;
an acid-functional additive (b),
A polyester resin (c), and an inorganic thickener (d) different from the inorganic salt (a). 14. A composition according to Claim 13 (wt% calculated relative to the total weight of said composition), comprising:
0.0001 to 1.0000% by weight of inorganic salt (a),
0.0100 to 5.0000% by weight of an acid-functional additive (b);
10.0000 to 50.0000% by weight of polyester resin (c),
0.1000 to 1.0000% by weight of an inorganic thickener (d) different from the inorganic salt (a);
43.0000-89.8899% by weight of components other than (a)-(d). A method of preparing a three-dimensional article comprising the steps of:
providing a composition according to claim 13 or 14;
shaping the composition into a desired three-dimensional shape; and curing the composition.