MXPA96006151A - Entrelazab compositions - Google Patents

Abstract

The present invention relates to: Interlaced compositions. In particular, the present invention relates to compositions that include a polymer having acid phosphorus and / or sulfur containing groups and an aliphatic polycarbodiimide crosslinker. Crosslinkable compositions include film forming compositions with paints, lacquers, varnishes, sealants, non-woven fabric binders, skin and adhesive coatings.

Description

Compositions E n tre 1 z abl e s The present invention relates to interlockable compositions. In particular, the present invention relates to compositions that include a polymer having acid groups containing phosphorus and / or sulfur and an aliphatic polycarbodiimide crosslinker. Crosslinkable compositions include film forming compositions such as paints, lacquers, varnishes, sealants, non-woven fabric binders, skin coatings and adhesives. It is well known that the addition of an interlayer to a film-forming coating formula can improve certain important properties of the formed coating, such as its hardness, solvent resistance and deterioration resistance. However, it is desirable to have an interlacing mechanism that is operated during or after film formation. If the interlacing mechanism has proceeded materially before the film formation has been substantially completed, the entire film formation process will be compromised and the resulting film will be very light and porous, with the result that the functions of Film protection will be severely damaged. In some applications heat can be used to assist in film formation and interlacing.

However, in many cases, the heat is not available so that the interlacing mechanism is operated under ambient conditions before the film formation is completed. The carbodiimides have the general structural formula of r- (N = C = N-r ') x, where r and r' are aromatic and / or aliphatic groups, which have been used as interlators. In this aspect, Patents US-A-4977219, EP-A-0277361 et al. reveal aliphatic polycarbodiimide crosslinkers, where both r and r 'are aliphatic groups. EP-A-0277361 discloses a mixed interlacer of aromatic and aliphatic polycarbodiimide, wherein each interlacing molecule contains some aromatic carbodiimides and some aliphatics. EP-A-0628582 discloses the use of aromatic polycarbodiimide crosslinkers, wherein r and r 'are aromatic groups. In all the aforementioned references, the use of polycarbodiimide crosslinkers is thought together with polymers containing carboxylate or carboxylic acid, and the crosslinking reaction takes place between the carbodiimide groups and the carboxylate or carboxylic acid groups in the polymer. US Pat. No. 5,352,400 discloses that polymers containing carbodiimide groups derived from isocyanates containing alpha-methylstyryl can be used to crosslink polymers with active hydrogen atoms which may be present in various groups, including phosphoric acid and partial esters thereof.

However, compositions incorporating carboxylic acid-containing polymers, on which the present invention is an improvement, are preferred for intertwining with polycarbodivides. Although aliphatic polycarbodiimide crosslinkers are commercially used with carboxylate-containing polymers, they suffer from certain drawbacks. In particular, with the aliphatic polycarbodiimide crosslinkers, interlacing with carboxylate groups is very rapid with the result that the interlacing mechanism is substantially completed before the film formation is finished. Therefore, despite the fact that a rapid interlacing step will usually lead to an increase in interlacing density and possibly improvements in solvent resistance, this decreases the film formation process. For example, there is a significant decline in property of resistance to deterioration. Therefore, rapid entanglement leads to the formation of regularly poor and brittle coatings because they are not well bonded. While aromatic polycarbodiimide crosslinkers react more slowly with carboxylate groups compared to aliphatic polycarbodiimides, and which consequently provide coatings with improved deterioration resistance, the resulting films tend to discolour in the presence of ultraviolet light, which is undesirable in many applications. The present invention seeks to overcome the problems associated with prior art coatings. In particular, the present invention aims to provide relatively non-toxic interlacing coating compositions which achieve non-yellowish, well-developed films. According to a first aspect of the present invention there is provided a crosslinkable composition that includes a polymer that binds at least two acid groups containing phosphorus or sulfur and an aliphatic polycarbodiimide. According to a second aspect of the present invention, a method is provided for interleaving a polymer composition by forming a polymer link at least two acid groups containing phosphorus or sulfur, an aliphatic polycarbodiimide mixing and curing the coating. An advantage of the present invention is that aliphatic polycarbodiimides do not discolour in the presence of ultraviolet light, as aromatic polycarbodiimides do. Another advantage is that the entanglement process is much slower than that of the prior art systems that incorporate polymers containing carboxylate and / or carboxylic acid and an aliphatic polycarbodiimide. It is believed that the entanglement process can be approximately one hundred times slower. The interlacing process is slow enough that occurs substantially during or after film formation with the result that improved extreme way a number of important requirements for a good coating, such as mar resistance. However, the entanglement is fast enough to be useful in an environmentally curated film in a typical industrial or architectural use. Therefore, the present invention lies in the discovery and recognition that a polymer comprising at least two acid groups containing phosphorus and / or sulfur reacts much slower with interleavers aliphatic polycarbodiimide compared to similar carboxylic acid groups containing polymer, and still reacts fast enough to be useful in commercial applications. The aliphatic polycarbodiimides of the present invention can be any compound containing two or more aliphatic carbodiimide groups. An aliphatic carbodiimide is defined herein as the group X-N = C = N-Y, wherein each of the groups X and Y are added to the N atom through an aliphatic C atom. Examples of aliphatic polycarbodiimides include the commercial product Ucarlnk® XL-29SE and prior commercial products Ucarlnk® XL-20, Ucarlnk® XL-25SE and Ucarlnk® XL-27HS (all from Union Carbide), commercial products EX-5558 (from Stahl Holland bv), as well as the compounds described in US-5081173, US-5047588, US-5136006, US-5373080 , EP-0241805, US-4487964, EP-0274402, EP-0277361 and US-5258481. The aliphatic polycarbodiimides may contain functional groups other than the aliphatic carbodiimides, provided that such additional functional groups do not interfere with the ability of the polycarbodiimide to crosslink polymers containing acid groups containing phosphorus and / or sulfur. In particular, the polycarbodiimide may contain a minority of aromatic carbodiimide groups. Preferred polycarbodiimides contain only aliphatic carbodiimide groups. The polymer according to the present invention can be any polymer capable of forming a film under drying / curing conditions to which it is subjected and which contains two or more acid groups containing sulfur and / or phosphorus. The polymers can be made from water or solvent. Examples of suitable polymers are polyacrylates, polyurethanes, polyureas, polyesters, polyethers and polyepoxides, as well as mixtures and hybrids such as graft or block copolymers of the listed polymers. The acid groups in the polymer can be totally or partially neutralized. A polymer addition formed by the aqueous emulsion polymerization of ethylenically unsaturated onomers is preferred. The polymer composition can be selected and the polymer prepared by conventional techniques known to those skilled in the art. Addition polymers are preferred. The polymer may contain one or more of the following copolymerized, ethylenically unsaturated monomers: linear or branched chain alkyl (meth) acrylates C? -C22 / bornyl (meth) acrylate, isobornyl (meth) acrylate and the like; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate; (meth) acrylamide or substituted (meth) acrylamides; styrene or substituted styrenes; butadiene; vinyl acetate or other vinyl esters; (meth) butylaminoethyl acrylate, (meth) acrylate di (methyl) aminoethyl; a monomer containing α, β-unsaturated carbonyl functional groups, such as furmarate, maleate, cinnamate and crotonate and (meth) acrylonitrile. Additionally, a low level of a multi-ethylenically unsaturated monomer, such as, for example, 0-10% by weight, based on the weight of the polymer of allyl (meth) acrylate, diallyl phthalate, di ( meth) 1,4-butylene glycol acrylate, 1,6-hexanediol-di (meth) acrylate and trimethylolpropane tri (methyl) acrylate. Preferably, the polymer contains one or more of the following copolymerized monomers: 2- (meth) -arylamido-2-methyl-1-propanesulfonic acid, 3-sulfopropyl (meth) acrylate, 2-sulfoethyl (meth) acrylate and (meth) 2-phosphoethyl acrylate. The polymer carries at least two acid groups containing phosphorus and / or sulfur. Preferably, the polymer has an acid number of from 5 to 100, preferably from 10 to 85, more preferably from 10 to 45 and still more preferably from to 30. More preferably, the linking polymer is formed predominantly from (meth) acrylic monomers or from styrene and (meth) acrylic monomers. Although the presence of carboxylic acids or carboxylates in the polymer leads to some pre-entanglement of the film, small amounts of carboxylic acids can be used, as they can be introduced into the polymer either advantageously as impurities or by hydrolysis during or after the reaction of polymerization or low levels of copolymerized carboxylic acid binding monomers, such as (meth) acrylic acid; ethylenically unsaturated dicarboxylic acid, or half of an ester thereof or anhydride thereof such as, for example, itaconic acid, fumaric acid, maleic acid, monomethyl itaconate, monomethyl fumarate, monobutyl fumarate and maleic anhydride. As such, polymers containing both carboxylic acids and acids containing phosphorus and / or sulfur are within the scope of the present invention. The amount of carboxylic acid groups that can be incorporated into a given polymer, without compromising properties that depend on good film formation, such as resistance to deterioration, will depend on the details of the polymer. For example, polymers with low molecular weight, such as a weight average molecular weight of 5,000, will be able to tolerate higher carboxylic acid contents, up to about 2% copolymerized carboxylic acid monomer, by weight based on the weight of the polymer, than polymers with a higher molecular weight, such as a weight-average molecular weight of 5,000,000, which may contain up to about 0.1% copolymerized carboxylic acid monomer, by weight based on the weight of the polymer. Other factors that will influence the degree to which a given amount of pre-entanglement will decrease film formation and, therefore, the properties that require good film formation, are the Tg of the polymer, the level of the phosphorus-containing acid or sulfur, the level of coalescing solvent included in the composition and the gel fraction and molecular structure of the polymer. It is preferred that the polymer does not contain carboxylic acid groups. The proportion of aliphatic polycarbodiimide groups to the polymer acid groups can be from 0.05 to 2.0, preferably from 0.25 to 1.0, on a base of equivalents.

Preferably, the aliphatic polycarbodiimide is water-soluble or water-dispersible when used with polymers made from water, but not water-soluble and non-dispersible on their own in water when used with polymers made from solvent. For example, preferred polycarbodiimides for coatings made from water would be Ucarlnk® XL-29SE and Ucarlnk® EX-5558, while a preferred polycarbodiimide for coatings made from solvent would be Ucarlnk® XL-20. The crosslinkable composition may be free of organic solvent or may contain a coalescing solvent. The crosslinkable composition may contain typical coating additives, such as binders, fillers, defoamers, other crosslinkers, catalysts, surfactants, stabilizers, anti-flocculants, aqueous or non-aqueous polymer-non-reactive solutions or dispersions (herein referred to as "non-polymer"). "reactive" as to the polymer substantially free of carbodiimide or acid functionality), mordants, coalescents, colorants, waxes, antioxidants, pigments and solvents suitable as water-irascible solvents. The crosslinkable composition can be formed by mixing a polymer carrying at least two acid groups containing sulfur or phosphorus and an aliphatic polycarbodiimide, using conventional mechanical stirring mixing techniques, such as stirring by means of a motor-driven stirring blade. The interlacing composition can be used, for example, as a coating for wood, a maintenance coating, a coating or "primer" for metal, a coating for plastic, paint for traffic, coating on substrates previously painted or exposed to the environment, coating or saturant for woven or non-woven fabrics, leather coatings, coil coatings, architectural coatings, mastic, caulking, caulking, table coating, paper coating, plastics coating, ink, varnish, floor covering and adhesive. The crosslinkable composition of this invention can be applied by methods well known in the art, such as by assisted spraying, airless spraying, plural component spraying, brushing, roller coating, roller coating, curtain cover and the like. After the crosslinkable composition is applied to the substrate the composition cures, that is, it is believed that the reaction occurs between the carbodiimide functionality and the acid functionality containing sulfur or phosphorus. Curing to achieve useful properties can take place at a convenient rate at ambient temperatures, such as from 0 ° C to 35 ° C. However, it is sometimes desired to accelerate the rate of property development by heating the interlayer composition applied at a temperature of 25 ° C to 200 ° C. A curing temperature of 25 ° C to 60 ° C is preferred. The "acid number" here is the mg. of the KOH required to neutralize 1 g. of solid polymer. The "hydroxyl number" here is the mg. of the KOH giving a molar equivalent to the amount of -OH groups in 1 g. of solid polymer. The "amine number" here is the mg. of the KOH giving a molar equivalent to the amount of -NH2 groups in 1 g. of solid polymer.

EXAMPLE 1. Preparation of Interlacing Compositions The following series of polymer samples were prepared, Table 1.1. Polymer compositions REF OLIMMER ACID FUNCTIONALITY P. acrylic / styrene polymer; No. acid = 9.0 A PS P.2 Acrylic / styrene polymer; No. acid = 13.0 MAA P.3 Acrylic polymer; Acid No. = 17.9 PEM P.4 Acrylic polymer; No. Acid = 17.9 AA P.5 Acrylic polymer; No. acid = 16.4 AMPS P.6 Acrylic polymer / styrene; Acid No. = 32.5 MAA where: AMPS = 2-acrylamido-2-methyl-1-propanesulfonic acid PEM = 2-phosphoethyl methacrylate MAA = methacrylic acid AA = acrylic acid The following series of interlacing compositions were prepared as follows: The order of mixing was from left to right (the quantities are given in grams of solid or active ingredients). The following abbreviations are used: MMP = pyrrolidone n-methyl EB = ethylene glycol, butyl ether DB = diethylene glycol, butyl ether PE = emulsified polyethylene wax Table 1.2. Composition Interlazable Cl and Comparative Compositions CA-CE Ref Pol NMP EB DB By 301 Wax PE Ucarlnk XL-29SE CA 100R.1 0 20 10 1 3 Cl 100R.1 0 20 10 1 3 10.2 CB 100R.2 7.5 CC 100R.2 7.5 9.5 CD 100R.6 7.5 1 3 CE 100R.6 7.5 1 3 23.8 Table 1.3. Interlocking Composition C2 and Comparative Compositions CF-CH Ref Resin EB DB Byk 301 wax PE Ucarlnk XL-29 SE EX5558 CF 100R.1 20 10 1 3 C2 100R.1 20 10 1 3 5.1 CG 100R.1 20 10 1 3 5.1 CH 100R.1 20 10 1 3 10.2 Table 1.4. C3 Interlaced Composition and CI-CL Comparative Compositions Ref. Resin EB DB Byk 301 wax PE Ucarlnk XL-29SE QRXP-1422PMN Cl 100R.3 10 10 1 C3 100R.3 10 10 1 11 CJ 100R.4 10 10 1 CK 100R.4 10 10 1 11 CL 10OR.4 10 10 1 8.2 Table 1.5. Composition C4 Interlazable and Comparative Compositions CM-CP Ref. Resin EB DB Byk 301 PE wax Uselnk XL-29SE QRXP-1 22PMN CM 100R.5 10 10 1 C4 100R.5 10 10 1 12 CN 100R.4 10 10 1 CO 100R.4 10 10 1 CP 100R.4 10 10 1 The QRXP-1422PMN is an aromatic polycarbodiimide made by Rohm and Haas Company.

EXAMPLE 2. Preparation of interlacing compositions films for testing and testing procedures.

The films of the prepared interlacing compositions were emptied into both aluminum panels, cherry plywood and metal panels painted black (Leneta Co., Product Code T12-10). The films were calculated in a wet film thickness of 7 to 10 ml. The films were dried with air at room temperature for 3 or 4 days before the test. The samples were then tested according to the following established test procedures.

PROOF OF RESISTANCE TO DETERIORATION. This test measured the resistance to deterioration of a coating surface by measuring the point of damage provided to a coating by driving the nail of the finger. In this test, the panels are covered with samples and then cured. Cured samples after testing for resistance to deterioration by means of two methods. In the first method ("surface deterioration") it was struck vigorously several times with the back of the finger nail. In the second method ("nailing deterioration"), the finger nail was clamped in the coating. Next, each coating was rated for each method on a scale of 0 to 10, where 10 = no mark. The results were reported as two values (x / y) corresponding to valuations for each respective method. An improvement of 1 is an important advantage.

TEST OF RESISTANCE TO WEAR BY CEM. This test measured the point of damage provided to a coating on a panel that is exposed to ethyl methyl ketone (CEM). A sample of cheesecloth was saturated with CEM. Then, using a Crockmeter (Atlas Electric Devices Inc.), the coating on the panel was scraped with the cheesecloth. The recorded value was the number of scrapes until the moment when the panel rupture was observed. The data was reported as double scrapings (a round trip game). The higher the number of scrapes, the better the coating film.

PROOF OF COMPOSITE SPOT. This test measured the spot spot on a coating film on a panel, after exposure to several solutions. The spots on the composite spots were water, 50% EtOH, Formula 409® and 9% aqueous acetic acid. The staining agents were in contact with the film for 16 hours and covered with a watch glass to prevent evaporation. Each spot was provided separately and the results averaged. Data were presented as initial classification / classification after 24 hours of recovery. The data was recorded on a scale of 0 to 10, where 10 is the best.

PROOF OF DROPS OF ACETONE. The test is similar to the Composite Stain Test, except that the staining solution was acetone and the film was exposed for 15 minutes. Data were presented as initial classification / classification after 24 hours of recovery. The data was recorded on a scale of 0 to 10, where 10 is the best.

PROOF QUV. The white section of a Leneta panel was covered and cured. The yellow point reading was made with a "Pacific Scientific ColorGuard System 5" using the Hunter L * a * b * scale. b * is a measure of yellowing where a larger positive value of b * indicates a more yellow film. After taking the initial values b *, the panels were placed in a Q-U-V machine of Q-Panel Company that is adjusted with QUV-A bulbs, and exposed for 24 hours, the change in b * was measured. Examples 3 to 6 show that the interlaxable compositions, according to the present invention, have deployment properties (C1-C4), such as deterioration resistance and solvent resistance, and this is better than the interlaxable coatings and the compositions of prior art coatings containing polymers with carboxylic acids entangled with aliphatic polycarbodiimides, and as good as prior art coating compositions containing acid-carrying carboxylic polymers, entangled with aromatic polycarbomides. Also, it is shown that the coating compositions, according to the present invention, have less tendency to become yellow with exposure to UV light, as compared to the coating compositions containing aromatic polycarbodiimides.

EXAMPLE 3. Evaluation of Interlocking Composition Cl. Substrate: Aluminum (deterioration, wear by CEM) and plywood (acetone drops and stains).

Composition C CAA C Cll CB CC CD CE Wear by EMC 3 3 1 10000 6 10 Acetone drop test 0/0 5/8 Test composite spot 4 4..88 // 66..88 6.3 / 8.9 Deterioration test 5 5 // 55 7 7..55 // 77..55 3/3 3 / 3 5/4 5/4 EXAMPLE 4 Evaluation of the interlocking composition C2 Substrate: Aluminum Composition CF C2 CG CH wear CEM 3 20 40 100 Test drops acetone 0/0 6/7 6/7 6/7 Test stains comp. 0.5 / 6, .0 2.0 / 7, .5 3.3 / 8, .3 6.0 / 8.1 Deterioration test 5/5 / 7.5 / 7. 5 3/3 3/3 EXAMPLE 5 Evaluation of the interlaxable composition C3 Substrate: Aluminum Composition Cl C3 CJ CK CL Test drops acetone 0/0 6/7 0/0 3/3 6/7 Deterioration test 5/5 5/5 5/5 3/3 5/5 EXAMPLE 6. Evaluation of the interlaxable composition C4 Substrate: Leneta panels (QUV) and aluminum (deterioration! Composition CM C4 CN co CP b * initial QUV -0.2 0.1 0.1 0.1 0.2 b * final QUV -0.7 0.8 0.0 0.8 7.8 Impairment test 6/6 6/8 5/6 4/4 6/7 EXAMPLE 7. Evaluation of the crosslinkable composition C5 compared to comparative compositions containing various functional groups having active hydrogen atoms. The aliphatic polycarbodiimide of U.S. Patent 5,353,400, Example 12 ("400") was prepared and used in this Example. The polymers used are given in Table 7.1.

Table 7.1. Functions of Polymer Polymer Type of Functionality and Quantity P.7 carboxylic acid, acid number = 20 P.8 primary amine, amine number = 39 P.9 alcohol, hydroxyl number = 121 P.10 phosphonic acid, acid number = 12 The compositions were prepared using the amounts in grams provided in Table 7.2.

Table 7.2. Compositions Composition EB BuAc CDI'400 CQ 25P.7 2 0 0 CR 25P.7 2 0 2.38 CS 25P.8 2 0 0 CT 25P.8 2 0 3.08 CU 5P.9 0 4 0 CV 5P.9 0 4 2.76 CW 25P.10 2 0 0 C5 25P.10 2 0 1.62 The compositions were lowered to a wet film thickness of 0.25 mm. in maple plywood and dried for 24 hours at room temperature. The results of the test are presented in Table 7.3.

Table 7.3. Results of the Composition Test Composition Test Acetone Drop Remarks CQ 0/0 dissolved CR 1/3 broken CS 0/0 dissolved CT 0/0 dissolved CU 0/0 dissolved CV 0/0 dissolved CW 0/0 dissolved C5 4/8 slight loss of diamonds Composition C5 crosslinkable of this invention exhibits a surprising, unexpected, entanglement capacity, which was measured by drop resistance of acetone when compared to the development of the comparative CQ-C compositions.

Claims (6)

Claims

1. An interlaxable composition comprising a polymer carrying at least two acid groups containing sulfur or phosphorus and an aliphatic polycarbodiimide. The composition according to claim 1, wherein said polymer is an aqueous dispersion of addition polymer, not soluble in water, formed by emulsion polymerization. 3. The composition according to claim 2, wherein said polymer comprises at least one copolymerized monomer that is selected from monomers consisting of 2- (meth) acrylamido-2-methyl-1-propanesulfonic acid, (meth) acrylate. 3-sulfopropyl, (meth) acrylate 2-sulfoethyl and (meth) acrylate 2-phosphoethyl, and wherein said polymer has an acid number of 5 to 100. 4. A method for entangling a polymer composition, comprising forming a polymer carrying at least two acid groups containing sulfur or phosphorus, mixing an aliphatic polycarbodiimide and curing said polymer composition. The method according to claim 4, wherein said polymer is an aqueous dispersion of addition polymer, not soluble in water, formed by emulsion polymerization. 6. The method according to claim 5, wherein said polymer comprises at least one copolymerized monomer that is selected from monomers consisting of 2- (meth) acrylamido-2-methyl-1-propanesulfonic acid, (meth) acrylate 3 -sulfopropyl, (meth) acrylate 2-sulfoethyl and (meth) acrylate 2-phosphoethyl, and wherein said polymer has an acid number of 5 to 100.