ES2354931T3 - GRAYED SELF-ADJUSTABLE POLYESTER RESIN. - Google Patents

Abstract

A method for preparing a grafted auto-stainless polyester resin in which the resin is obtained in steps comprising: a) grafting at least one diacid or its anhydride into a first agent by a Diels-Alder and / or Ene reaction; and b) reacting the product of step a) with a second agent; wherein the first agent comprises at least a first functionality selected from a group consisting of a first series of conjugated double bonds or a first allyl hydrogen; wherein the diacid or its anhydride and the second agent are further reacted with a terminal protective fatty acid, wherein the terminal protective fatty acid is an unsaturated carboxylic acid (C10-C28); wherein the first agent comprises at least one additional functionality selected from the group consisting of a series of conjugated double bonds, allylic hydrogen, unconjugated double bond, OH group, COOH group and amino group; wherein the second agent is selected from the group consisting of alcohol with a numerical average hydroxyl functionality> 2.0, dialkanolamine or mixtures thereof; and where the grafted auto-stainless polyester resin has an oil / resin ratio> = q 80, a number average molecular weight Mn> = q 1000 g / mol and a PDI> = q 3.

Description

Grafted auto-stainless polyester resin.

The invention relates to a method for preparation of a grafted auto-stainless polyester resin, the grafted auto-stainless polyester resin obtained by said method, the use of grafted auto-stainless polyester resin in a high solids coating composition, and a coating composition comprising polyester resin grafted auto stainless.

Alkyd paints for applications Professional and DIY are subject to restrictions increasing technical and ecological. Due to environmental protection, reduction in emissions of organic compounds is required volatile and the use of alkyd resins with high content of Solids is a solution for this problem. The technical problem essential in the formulation of coatings with a high content of solids is the reduction of resin viscosity without effect important adverse about the coating properties such such as drying properties and hardness.

US 2,706,191 describes a production method of synthetic or polymeric synthetic bodies that contain both ester bonds and amino or amido bonds, soluble in isopropanol-xylol and susceptible to crosslinking and curing when heated in admixture with a curing agent aldehyde

GB 1221432 refers to polyester resins unsaturated soluble amides that are soluble in a variety of solvents, providing a process for manufacturing such resins

EP 1172395 refers to a process for production of polymerizable coating compositions or of molding comprising reacting a filodiene with unsaturated triglycerides in a vegetable oil and react this one with a polycondensed compound selected from polyols, epoxides and diamines.

DE 1495142 refers to alkyd resins in which an adduct of carboxylic acid or ester with bonds Double conjugates are reacted with a polyvalent alcohol.

US 2,146,671 refers to synthetic resins produced by reaction of polybasic acids or their esters partial with equivalent proportions of alcohols versatile

US 3,644,237 concerns the production of polyurethane foams formed by reaction between a polyisocyanate  and a glycol ester of a tribasic adduct.

WO 2005 // 012370 refers to components hydroxy functional binders containing a main chain linear or branched that has a polymethylene structure or polyester, said components having grafted structures of Cyclic imide in the main chain.

JP 2000169653 describes a resin that is a Diels-Alder reaction product of a resin, a unsaturated carboxylic acid or its anhydride and a divalent alcohol for printing inks.

JP 2007046000 describes a resin composition alkyd obtained by the esterification of polyvalent alcohol, a oil or monoester of fatty acid and a carboxylic acid unsaturated

RO86737 describes an adduct of an acid unsaturated dicarboxylic with an unsaturated vegetable oil.

It is an object of the invention to provide a method of preparing a grafted auto-stainless polyester resin for a high solids alkyd coating. In another aspect of the invention, the object is to provide an improved grafted auto-stainless polyester resin or an improved coating composition comprising a grafted auto-stainless polyester resin. The improvement may be, for example, that a coating comprising the grafted auto-stainless polyester resin exhibits one or more desired properties such as, for example, flexibility, outdoor durability, rapid drying, high solids content, low viscosity and / or stability of the
color.

In a method according to the invention, the grafted auto-stainless polyester resin is obtained by grafting a diacid or its anhydride in a first agent and subsequent reaction of the diacid or its anhydride with a second agent that can be alcohol, dialkanolamine or mixtures thereof. For more clarity, the singular form of diacid, anhydride, alcohol, or Dialkanolamine includes both the singular and the plural.

       \ vskip1.000000 \ baselineskip
    

Specifically, the invention relates to a method for preparing a self-polyester polyester resin grafted according to the attached claim 1 wherein the resin is obtained by steps comprising:

to)

graft at least one diacid or its anhydride into a first agent by a Diels-Alder and / or Eno reaction; Y

b)

react the product from step a) with a second agent;

quad

wherein the first agent comprises at least one first selected functionality of a group consisting of a first series of conjugated double bonds or a first hydrogen allylic;

quad

wherein the first agent comprises at least one additional functionality selected from the group consisting of a series of conjugated double bonds, allyl hydrogen, double bond unconjugated, OH group, COOH group and amino group;

quad

where the second agent is selected from the group consisting of alcohol with a medium hydroxyl functionality numerical> 2.0, dialkanolamine or mixtures thereof; Y

where the auto-polyester polyester resin grafted has an oil / resin ratio ("length of oil ") ≥ 80, a number average molecular weight Mn ≥ 1000 g / mol and a PDI ≥ 3.

       \ vskip1.000000 \ baselineskip
    

Preferably, the graft from step a) is performed by a Diels-Alder reaction.

In another embodiment a resin is provided grafted auto-stainless polyester that can be obtained by the method according to the invention.

Resin autoxidation in compositions coating, also known interchangeably as drying oxidizing or air drying, it takes place mainly by the crosslinking formation. With the term cross-linking by autoxidation is understood that crosslinking is the result of a oxidation that takes place in the presence of air and usually implies a free radical mechanism and is preferably catalyzed by metals, resulting in covalent crosslinks.

In this context, it should be understood that the term diacid or its anhydride incorporates the diacid alone or a mixture of diacids, the anhydride alone or a mixture of anhydrides, and any combination of diacid (s) and anhydride (s) of acid.

Due to the increased reactivity of the anhydrides, it is preferred that at least part of the "diacid or its anhydride "is an anhydride and it is more preferred to use Mainly or exclusively the anhydride.

The diacid or its anhydride should be selected from diacids or anhydrides that are susceptible to grafting in a First agent Particularly, it has been found to be advantageous that the diacid or its anhydride comprise at least one double bond. This allows the diacid or its anhydride to be grafted into the first agent by the reaction of Eno or Diels-Alder as describe later. The group of diacids and anhydrides advantageous therefore preferably comprises maleic acid, anhydride maleic, itaconic acid, fumaric acid or mixtures thereof. Less preferred, but still belonging to this group, are tetrahydrophthalic acid and tetrahydrophthalic anhydride. The more preferred from this group for use in the reaction Diels-Alder is maleic anhydride; but nevertheless, satisfactory results were also obtained with acid fumaric

It is highly preferred that the diacid or its anhydride comprises at least 80% of the molar amount of diacid or its anhydride selected from the group consisting of maleic acid, maleic anhydride, itaconic acid, fumaric acid or mixtures thereof. The remainder of the diacid or its anhydride is also selected wholly or partially preferably from this group, but may also comprise other diacids or anhydrides that can be grafted by the Eno or Diels-Alder reaction, and diacids or anhydrides that cannot be grafted by the Eno reaction or
Diels-Alder.

The most preferred diacid and anhydride Corresponding are maleic acid and maleic anhydride. This is mainly due to the high reactivity due to the combination of structural relationship between the double bond and the two groups carbonyl or the anhydride group combined with a configuration sterile favorable. Therefore, in a preferred embodiment, the diacid or its anhydride is substantially maleic acid or anhydride Maleic By substantially maleic acid or maleic anhydride, understand herein that maleic acid and anhydride maleic represent more than 95% of the molar amount of the diacid or grafted auto-stainless polyester resin anhydride, such as more than 98% of the molar amount of the diacid or anhydride. Acid maleic and maleic anhydride can be used individually without the other or as a mixture of acid and anhydride.

The first agent comprises at least a first selected functionality of a group consisting of a first series of conjugated double bonds or a first allyl hydrogen, since this allows the first agent to experience a graft favorable with the diacid or its anhydride. Particularly, it has found that it is advantageous that the diacid or its anhydride understand a double bond so that the graft can have place by the Diels-Alder reaction or Eno reaction. The Diels-Alder and Eno reactions are very advantageous in the present invention, since these reactions are cheap and easy to drive However, others are also possible known polymerization reactions to achieve grafting. The Diels-Alder and Eno reactions are fast and relatively simple to perform, and reactions are not contemplated substantial secondary. From a manufacturing point of view, the present methods and products therefore also represent a Great step forward. The reactions are exothermic, but it has found that this could be advantageously controlled by mixing a compound that is used for the preferred terminal protection of the OH groups in the reactor at an initial stage such that the terminal protection molecules can act as a thermal stabilizer

The Diels-Alder reaction is a Cycloaddition between a conjugated diene and a substituted alkene. In the present invention, the conjugated diene is preferably found in the first agent. Conjugated diene means

       \ vskip1.000000 \ baselineskip
    

one

       \ vskip1.000000 \ baselineskip
    

where Rα and Rβ are parts of the main chain of the compound comprising originally the double link series conjugates

       \ vskip1.000000 \ baselineskip
    

The reaction takes place going through a state of singular transition leading to grafted diacid or anhydride grafted as shown below:

2

where Rα and Rβ are parts of the main chain of the compound comprising originally the series of conjugated double bonds and where Rγ and Rδ are parts of the diacid or anhydride.

       \ vskip1.000000 \ baselineskip
    

The substituted alkene is typically located in the main chain of the diacid or its anhydride. However, the opposite situation where the conjugated diene is present in the diacid or its anhydride and the substituted alkene is in the First agent is also feasible in the present invention. Diene conjugate must be able to exist in the s-cis formation to sterically improve the Diels-Alder reaction. An example of a suitable diene is tung oil and oil dehydrated castor.

In accordance with the present invention, the Diels-Alder reaction should be conducted preferably at temperatures of about 140 ° C to 200 ° C, and more preferably at temperatures of about 150 ° C to 175 ° C, since this leads to an adequate reaction rate without substantial degradation of the product or substances reactants

It should be noted that the reaction Diels-Alder is reversible and therefore, in a preferred embodiment, the amount of the first agent used is substantially greater than the stoichiometric ratio, in order to force the reaction to the grafted molecule.

       \ vskip1.000000 \ baselineskip
    

The Eno reaction is a chemical reaction between a alkene with an allyl hydrogen and a compound containing multiple links In the present case, the allyl hydrogen is preferably found in the first agent and when the first agent is a fatty acid or a modified fatty acid, hydrogen allyl is preferably far from an acid group of the First agent By allyl hydrogen is meant an atom of hydrogen located in a carbon atom adjacent to a carbon that it carries a double bond, such as the H 'in

       \ vskip1.000000 \ baselineskip
    

3

       \ vskip1.000000 \ baselineskip
    

where R 1a and R 2a form part of the main chain (or an H) of the compound comprising the hydrogen allylic

       \ vskip1.000000 \ baselineskip
    

The multiple link is preferably a link double carbon-carbon located on the main chain of the diacid or its anhydride. Most preferably, the double bond is located near an electrophile group, such as one or more of the acid groups or the acid anhydride group.

An example of a first agent with a hydrogen Allyl is soybean oil or flaxseed oil.

       \ vskip1.000000 \ baselineskip
    

The Eno reaction takes place by formation of a activated intermediate ring and leads to an alkene substituted with a double link as shown below:

       \ vskip1.000000 \ baselineskip
    

4

       \ vskip1.000000 \ baselineskip
    

where R y and R x are a oil residue (fatty acid chain) and R 'and R' 'are part of the diacid or anhydride.

       \ vskip1.000000 \ baselineskip
    

In accordance with the present invention, the Eno reaction should preferably be conducted at approximately 140 ° C to 200 ° C, preferably about 170 ° C to 195 ° C, given that this leads to an adequate reaction rate without substantial degradation of the product or reactants. Therefore, if the graft reaction is based exclusively in the Eno reaction or a combination of the reaction Eno and the Diels-Alder reaction, then it is a two-step process is necessary for group formation ester and / or amide, since the first agent can begin to decompose or self-polymerize at least in the highest zone of the Eno reaction conduction temperature range favorite. Only ester groups or exclusively amide groups in a simple process, but it is also possible any combination of ester groups and amide groups trained in a single process.

       \ vskip1.000000 \ baselineskip
    

In the present invention, it has been found that grafting by Eno reaction or reaction Diels-Alder leads to very advantageous resins, for which were surprisingly low viscosities for a high molecular weight Additionally, it was observed with surprise that the use of the resin according to the invention in a coating leads to a reduction in initial drying time and drying faster coating depth. It could be theorized (without be limited by it) that this is caused because the reaction Eno and the Diels-Alder reaction lead to a very compact grafted auto-stainless polyester resin molecule, substantially spherical with very high molecular weight. Without However, the strongest influence on the properties of resins grafted self-oxidizing polyester obtained comes from a special combination of high oil / resin ratio and weight relatively high molecular, all referred to the first agent. This is because:

to)

 the High oil / resin ratio ensures:

i)

low VOC values even for high values of molecular weight; also

ii)

rapid diffusion of oxygen in the most layers deep film necessary for solidification in fast enough depth of paint layers thick

b)

 he relatively high molecular weight value ensures a limited oxygen concentration necessary to reach the transition from liquid to solid state (drying).

       \ vskip1.000000 \ baselineskip
    

The invention also allows the production of binders with a high oil / resin ratio that contain a high concentration of unsaturated double bonds (groups reagents).

The grafted auto-stainless polyester resin has oxidizing / drying properties in the air due to the fact that after the first reaction between the diacid or its anhydride and the first agent, there are still two free unsaturated bonds that can further participate in the self-oxidation process. As a result, not only the outer part, but also the core of the grafted (hyperbranched) auto-stainless polyester resin can be dried by auto-oxidation. This feature of the invention is different from the polyester (hyperbranched) resins known from the prior art, because the prior art polyester resins have an acid core that does not appear
dry up.

       \ newpage
    

An advantage of also having the core susceptible to autoxidation is that drying takes place quickly because oxygen can easily penetrate the resin layer In this way, rapid drying takes place in depth: a complete solidification of the resin layer self-adhesive polyester grafted in all its thickness, without formation of skin. Skin formation is a well known drawback of the coatings because it prevents deep drying of The resin layer

The oil / resin ratio is defined as the number of grams of oil used to produce 100 g of the grafted auto-stainless polyester resin.

For the purpose of the invention, the relationship oil / resin resin grafted auto-stainless polyester is preferably? 80. In a more preferred embodiment, the oil / resin ratio of grafted auto-stainless polyester resin it is between 80 and 98, and even more preferably between 85 and 96.

As a result of the high relationship oil / resin preferred for the auto-polyester polyester resin grafted, the viscosity of the auto-polyester polyester resin graft of the invention is quite low, which makes the polyester resin of the invention for compositions having a high solids content The viscosity of the polyester resin of the invention is significantly less than for polyesters Traditional of a similar molecular weight. For example, for 100% of solids content, the polyester resin of the invention has preferably a viscosity less than 500 Pa.s when measured at 23 ° C.

The average number molecular weight Mn of the resin grafted auto-stainless polyester is preferably ≥ 1000 g / mol In a more preferred embodiment, the Mn is comprised in the range of 1000 g / mol to 10,000 g / mol.

The polydispersity index (PDI) is defined as the relationship between the weight average molecular weight Mw and the number average molecular weight Mn (PDI = Mw / Mn). Preferably, the polydispersity index is ≥ 3, more preferably the Polydispersity index is ≥ 5, and even more preferably the polydispersity index is ≥ 10; however it is possible even reach a polydispersity index greater than 25.

Due to the specific combination of a high oil / resin ratio and weight average molecular weight Relatively high, the grafted auto-stainless polyester resin of the invention is a binder very suitable for formulation of coating compositions having a low viscosity coupled with rapid drying to achieve solidification fast thick film layers of architectural paintings low in VOC through autooxidation.

Quick air drying is favored also by the main air drying chain of the resin grafted auto-stainless polyester that is not present traditionally in other types of polyester drying resin hyper-branched type air manufactured traditionally.

The combination of a high ratio oil / resin and yet a relatively high Mn (or Mw) is a unique combination of polyester resin properties grafted stainless steel of the invention because generally the Molecular weight tends to decrease with increasing ratio oil / resin By using a traditional product chemistry alkyd, this combination of high oil / resin ratio and Mn still relatively high it is very difficult to reach.

To make it possible for the functionality of the resin increase or make possible subsequent reactions of the first agent, the first agent should additionally comprise at least other functionality, such as one, two, three, four or more additional functionalities When the first agent is a molecule larger in size such as an oil molecule, the number of Additional functionalities may be greater, such as 6-12 or even more. Functionality is understood as in this context the presence of a functional group. Preferably, the first agent comprises at least one additional functionality selected from the group consisting of a series of conjugated double bonds, allyl hydrogen, double bond unconjugated, OH group, COOH group and amino group.

It should be noted that the functionality of the combined diacid or anhydride grafted molecule in the first agent has a combined functionality of at least three (two acid groups / double functionality of the anhydride group and the functionality of the "additional functionality" of the first agent). For this reason, the two acid groups or the anhydride group they can react with a second agent to form a chain main similar to a polyester while the functionality Additional first agent (from fatty acid) may form bonds (crossed) (crosslinks) with nearby molecules or with the same molecule. In this way a very compact structure is formed hyper-branched type.

The first agent will typically provide so much weight molecular as functionality to the resin by grafting. Could theorized (without being limited to it) that due to the structure three-dimensional grafted self-oxidizing polyester resins of according to the invention, this increase in molecular weight and functionality is achieved without substantial increase in the size of the resin molecule and change the substantially spherical shape of the molecule For this reason, the average molecular weight of the resin is increases without the increase in viscosity that would be expected typically for an increase in the molecular weight of the polymers. Additionally, it could be used (without being limited by it) that the spherical shape allows the observed reduction of drying initial as well as faster deep drying and that the increased functionality allows the formation of a reticulum three-dimensional final more robust after curing as well as large opportunities for adapting resin properties polyester of the invention.

Preferably, the first agent is selected from the group consisting of unsaturated fatty acids, fatty acids Modified and oils. The first agent can be derived from a Natural source or it can be a synthetic molecule. the use of a first agent derived from a natural source is advantageous with regarding high availability and low cost, but in some cases it can be disadvantageous in the case of a relatively variation high molecular structure of the first agent.

It has been found that it is particularly advantageous for the first agent to have more than one additional functionality. It could be theorized that this may be due to the even more compact spherical structure and that this will lead to increased self-cross-linking or branching. This can be achieved for example by the use of glycerides (synthetic or natural source), such as tung oil, as the first agent. Tung oil typically has a capacity to graft 4-6 diacid or anhydride molecules and therefore leads to a highly branched structure. Other oils or first synthetic agents may have the ability to graft more diacid or anhydride molecules, for example up to 10, 15, 20 or even more, in the case of first highly functional agents.
lized.

The first synthetic agents can be derived for example by reaction between smaller organic molecules with a well defined structure. A very preferred class of first synthetic agents are fatty acids comprising conjugated double bonds that have reacted with glycerol, pentaglucose or other sugars, such as penta-acid and / or rosin or penta-acid ester and / or fatty acid ester of tung oil The first synthetic agents are advantageous in that they have a relatively known structure with limited variation and thus allow a better defined final structure of the grafted auto-stainless polyester resin. Additionally, higher glycols (with OH functionality greater than 2) allow a greater degree of branching with greater freedom to adapt the properties of the final resin. The first synthetic agent can be synthesized before the preparation of the grafted auto-stainless polyester resin or in situ during the synthesis of the grafted auto-stainless polyester resin. Preferred examples of higher glycols are dipentaerythritol and sugars.

In relation to functionality, it is preferred that the first agent comprises at least four double bonds, preferably the first agent comprising at least two series of conjugated double bonds and most preferably comprising minus three series of conjugated double bonds. This makes possible that the first agent with more than one diacid or its anhydride is graft into another first agent in the same molecule or in molecules neighbors Said additional graft can take place during the resin preparation. Alternatively, such double bonds Additional may participate in cross-linking during curing of a coating composition comprising the polyester resin grafted stainless steel according to the invention.

Resins can be obtained particularly advantageous when the first agent comprises at least 80% by weight selected from the group consisting of unsaturated oils such such as soybean oil, taloil, tung oil, marigold oil, rosin, sunflower oil, dehydrated castor oil, oil of flaxseed, corresponding fatty acids (for example fatty acid of tung oil, taloyl fatty acid or soy fatty acid), corresponding esters (for example rosin esters, or fatty acid esters of tung oil) and mixtures of same. This group includes mixtures of group members, such as mixtures comprising different types of the same kind of compounds (for example soybean oil together with tung oil), mixtures comprising equal types of different kinds of compounds (for example tung oil together with fatty acid from tung oil), and mixtures comprising various types of different kinds of compounds (for example tung oil together with soybean oil fatty acid and rosin esters). Preferably, unsaturated oils and fatty acids and Derived esters are oils and derivatives several times unsaturated, that is oils, fatty acids or esters that have two, three or more double bonds First most preferred agents are taloil, oil of tung, marigold oil, rosin, sunflower oil, oil dehydrated castor, flaxseed oil, fatty acids corresponding (for example tung oil fatty acid or acid fatty soybean oil), and corresponding esters (for example rosin esters, or fatty acid esters of oil tung)

The first most preferred agent is fatty acid of soy and / or tung oil, preferably comprising a resin according to the invention a first agent with at least 80% in Tung oil weight. Preferably, the first agent is substantially tung oil. For substantially tung oil it is understood in this report that they are only present smaller amounts of other first agents, comprising the first agent more than 95% by weight of tung oil, with more Preference more than 98% by weight of tung oil.

Preferably, the first agent has at least an eleostearic rest. In this memory it is understood by rest eleostearic a remainder that is made up of three double bonds conjugates Examples of first agent containing residues of this Type include among others eleostearic acid, tung oil or Marigold oil These have in their structure one or more remains Eleostearics The advantage of the case where the first agent contains an eleostearic residue is that it has a drying efficiency in the air much better than an oil that does not contain a remainder Eleostearic In this case, even when some of the double links are reacted after grafting, a hydrogen is formed activated which ensures the air drying of the polyester resin grafted auto stainless.

       \ newpage
    

Tung oil is composed fundamentally by eleostearic acid which is a fatty acid of 18 carbons that has 3 conjugated double bonds (a remainder eleostearic). This structure is advantageous because after the Diels-Alder reaction of the eleostearic residue of, for example, tung oil with the diacid or anhydride, a activated hydrogen, as shown below:

5

where R_ {1} and R2_ are oil residues (fatty acid chain) and R 3 and R 4 are part of the diacid or anhydride.

Activated hydrogen can participate subsequently in the autoxidation process and therefore the oxidation curing rate (air drying) is increases

The two acid groups or the anhydride group of first grafted agent can react further with a second agent to form a main chain of polyester type, with which a compact type structure is formed hyperbranched

The second agent is selected from the group of alcohol, dialkanolamine or mixtures thereof.

If the second agent is a dialkanolamine or a mixture of dialkanolamine and alcohol, the resulting polyester is generally designated as a "polyesteramide". For better clarity, in this invention the term polyester also includes therefore polyesteramides.

The characteristics will be explained below. special case in which the second agent to react is a dialkanolamine and the resulting polyester resin of the invention is a grafted auto-stainless polyester resin.

The dialkanolamine comprises alkanol groups with At least two carbon atoms. The alkanol groups can be Same or different. In a preferred embodiment, the dialkanolamine is:

6

In whose formula:

7

in which R 1, R 2, R 3, R 4, R 5 and R 6 can, independently from others, be the same or different, H or C1-C4-alkyl.

By C1-C4-alkyl is understood herein memory any alkyl group having 1 to 4 carbon atoms, that is methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl and 1-methylpropyl.

It was found advantageous to use a relatively small dialkanolamine, wherein R 1, R 2, R 3, R 4, R 5 and R 6 can, independently from others, be the same or different, H, or CH 3, since this It allowed a compact polymer with high functionality. Be found dialcanolamine particularly preferably in the that R 3 and R 6 are CH 3 and / or R 1, R 2, R 4 and R 5 are H. It was found extremely favorable to use diisopropanolamine such as dialkanolamine. Therefore it is advantageous to use a large content of diisopropanolamine. For great Diisopropanolamine content means that dialkanolamine It comprises at least 80% by weight of diisopropanolamine. Preferably, the dialkanolamine comprises at least 90% of diisopropanolamine. A higher content, such as at least 90% of diisopropanolamine led as a rule to better results and, most preferably, the dialkanolamine is constituted by diisopropanolamine.

In a very preferred embodiment, for the resin of grafted auto-stainless polyester polyamide the OH value should be preferably ≤ 10 KOH / g, more preferably ≤ 5 KOH / g. Most preferably, the OH value is close to 0, such as? 3 mg KOH / g resin. This is intended to improve the reaction of curing of the final resin, since the decrease in OH value reduce the amount of secondary amine, secondary amine that can complex with the cobalt present in the accelerator (salt desiccator) of the coating composition.

An additional aspect of the reaction concerns a grafted auto-stainless polyester resin component which contains at least one diacid or its anhydride grafted into a First agent A carboxyalkylamide group of the resin component Poliesteramide is represented by the following formula 1:

8

In whose formula

9

wherein R 1, R 2, R 3, R 4, R 5 and R 6 may, independently of each other, be the same or different, H or C1-C4-alkyl, and R 7 and R 8 they can, independently of each other, be the same or different, H, a moiety derived from an unsaturated carboxylic acid (C10-C28) (also referred to as a terminal protected fatty acid) or an ester. Acid carboxylic acid is preferably an unsaturated fatty acid with 10 to 28 carbon atoms Examples of suitable carboxylic acids include dehydrated castor oil fatty acid, acid linoleic and / or acid linolenic

Examples of useful fatty acids from oils Natural are taloyl fatty acid, oil fatty acid sunflower, corn oil fatty acid, oil fatty acid cotton, peanut oil fatty acid, oil fatty acid Flaxseed, soybean oil fatty acid, fatty acid oil rapeseed, rice bran oil fatty acid, Safflower oil and / or sesame oil fatty acid. They can mixtures of unsaturated fatty acids are also used. Preferably, the carboxylic acid is fatty acid of soy or taloil fatty acid.

B, the diacid or its main anhydride chain they should be able to get involved in the Eno reaction or Diels-Alder. The most preferred diacid B is anhydride maleic:

10

Preferably, the polyesteramide resin grafted auto-stainless that can be obtained by the method of invention comprises at least one diacid or its anhydride grafted into a first agent, where the carboxyalkylamide group is represented by formula 1 shown previously, in which R1, R2, R3, R4, R5 and R6 can, independently of each other, be the same or different, H or C1-C4-alkyl; R 7 and R 8 they can, independently of each other, be the same or different, H, a moiety derived from an unsaturated carboxylic acid (C_ {10} -C_ {28}), or a C1-C20-saturated or unsaturated alkyl attached to ester; where in said B the diacid or its main chain of anhydride is maleic anhydride; where the first agent understands at least one first functionality selected from a group consisting of a first series of conjugated double bonds or a first allyl hydrogen; and where the first agent comprises the less additional functionality selected from the group consisting of a series of conjugated double bonds, hydrogen allyl, unconjugated double bond, OH group, COOH group and group Not me.

Alcohol can be in principle any hydroxyfunctional compound (i.e. it contains group (s) OH) or mixture of hydroxy functional compounds with functionality numerical mean of hydroxyl> 2.0. By hydroxyl functionality numerical mean is understood herein to keep in mind that even when the individual alcohol molecule has a discrete number of hydroxy groups, mixtures of alcohols will typically have a medium hydroxy functionality not discrete. For example, a molecule can have a hydroxy functionality of 1 and another molecule can have a hydroxy functionality of 3. This It will lead to a numerical average hydroxy speed of 2.

In a preferred embodiment, the alcohol has a numerical average hydroxyl functionality ≥ 2.5, even more preferably ≥ 2.8 and most preferably ≥ 3.

In a preferred embodiment, the alcohol has a numerical average functionality of hydroxyl? 15, preferably? 10, more preferably? 8, even more preferably? 6, still more preferably? 4.5 and very preferably? 3.5, since this will allow at least part of the alcohol participates in crosslinking with a molecule of neighboring polymer or with the same polymer molecule.

Alcohol can comprise aliphatic parts and / or aromatic parts depending on the required properties of the resin In a preferred embodiment, it was found surprisingly that when alcohol comprises at least one aliphatic ring, then the resulting resin tends to exhibit a increased hardness

Alcohol can comprise other groups functional, such as for example one or more acidic groups, groups amine, urea groups, ester groups, unsaturations, etc. But nevertheless, it is preferred that alcohol has only a limited number of others functional groups. Particularly, it has been found to be advantageous to have the average numerical functionality of amine less than approximately 0.2, since this significantly reduced the yellowing

The term alcohol here designates both individual alcohols (pure) as mixtures of alcohols, unless otherwise indicated. The individual alcohols have preferably a functionality of at least 2 to ensure that Alcohol does not act as a terminal protection group. The alcohol it can be a mixture of several alcohols with the same or different functionality (hydroxy groups and / or other functional groups).

In a preferred embodiment, at least 50% in Alcohol weight has a hydroxy functionality? 3, more preferably ≥ 4. More preferably, at least 50% by weight of alcohol has three functional groups, and even more preferably at least 50% by weight of the alcohol has four groups functional. Particularly, it has been found to be advantageous use an alcohol, in which at least 80% by weight of the alcohol it has a hydroxy functionality ≥ 3, more preferably ≥ 4. More preferably, at least 80% by weight of the alcohol it has three functional groups, even more preferably at least 80% In alcohol weight it has 4 functional groups. In one embodiment particularly preferred, the functionality of alcohol has mode substantially only hydroxy functionality, such as at least 90% by weight of the alcohol has hydroxy functionality, or the alcohol has exclusively (i.e. 100% by weight) hydroxy functionality.

Preferably, at least 50% by weight of the alcohol is selected from the group consisting of glycerol, trimethylolpropane, pentaerythritol, di-pentaerythritol, tri-pentaerythritol, isosorbide, bisphenol A hydrogenated, ethylene glycol, propylene glycol, polyethylene glycol, diethylene glycol, neopentyl glycol, sugars such as for example cellulose, sucrose, fructose and the like, polyglycerols that have from 2 to 10 OH groups and mixtures thereof. In a very realization preferred, the alcohol consists substantially of one or more alcohols selected from the group consisting of glycerol, trimethylolpropane, pentaerythritol, isosorbide, bisphenol A hydrogenated, ethylene glycol, propylene glycol, polyethylene glycol, diethylene glycol, and neopentyl glycol. In this context, it should be understood that "substantially constituted of" means that virtually all of the alcohol, such as more than 90% by weight, more than 95% by weight or more than 98% by weight of alcohol is selected from the group consisting of glycerol, trimethylolpropane, pentaerythritol, isosorbide, hydrogenated bisphenol A, ethylene glycol, propylene glycol, polyethylene glycol, diethylene glycol and neopentyl glycol

The ratio of diacid equivalents or their anhydride, A, to graft functionality, x, multiplied by the ratio of equivalents, M, of the first agent (A: (x-M)) is preferably between 0.25: 1.00 and 1.50: 1.00, where

A = the molar amount of the diacid or its anhydride,

M = the molar amount of the first agent, and

x = the graft functionality of the first agent.

By graft functionality, x (of the first agent) the number of suitable sites is understood herein for grafting per molecule of the first agent, such as the number of allylic hydrogens and the number of double bond series conjugates The grafting functionality of the first agent is a integer for the individual molecule, such as 1, 2, 3, 4, 5, 6 or even more, but since the first agent can be constituted by a mixture or can be derived from a natural source with some structure variation, the graft functionality of the first agent is not typically an integer, but rather a positive rational number. Preferably, the functionality of grafting of the first agent is at least 1, and preferably 1.5 to 5. For the smaller amount of the first agent, a number of diacid or anhydride molecules that have double bonds, what which makes it possible again for the diacid or its anhydride to participate in subsequent reactions such as crosslinking or reaction with terminal protected fatty acids or other chemical species or additives The highest amount of first agent corresponds to the situation in which substantially all diacids and anhydrides corresponding are grafted to the first agent. This allows a well defined intermediate compound and therefore a product well defined finish, and is particularly used for mixing  external resins (see below). The most preferred relationship of the diacid or its anhydride to the first agent (A: (x-M)) is close to 0.50: 1.00, as between 0.40: 1.00 and 1.00: 1.00. This leads to a well defined product that It is very suitable for further mixing with other polyesters and Other types of resin.

Preferably, the molar ratio of the second diacid agent or its anhydride is ≥ 0.5, more preferably ≥ 1.0 and most preferably ≥ 2.0. Smaller quantities of diacid or its anhydride correspond to the situation in which the second agent (i.e. alcohol, alkanolamine or mixtures of the same) is allowed to react with other species such as acids fatty The largest amount of diacid or its anhydride corresponds to the situation with excess acid groups. This provides typically a resin with very low average molecular weight, and by adjustment of the relationship between the diacid or its anhydride and the second agent at this end of the interval, you get a very control fine of the final average molecular weight. The reaction between the second agent and a fatty acid or other reagent with affinity to react with the alcohol and / or dialkanolamine groups specific to the second agent can be conducted simultaneously with or after the reaction between the diacid or its anhydride and the second agent. Be prefers to conduct the reaction between fatty acid and the second agent simultaneously to the reaction between the diacid or its anhydride and the second agent since this allows better control of the process, particularly with respect to temperature control or during the exothermic graft reaction.

A first method according to the invention is preferably leads with the graft reaction between the diacid or its anhydride and the first agent that is separated at least partially in time and / or reaction space between the second agent and diacid (grafted) or its anhydride.

In a second method according to the invention, the two graft steps and the formation of ester groups and / or amide can be conducted simultaneously in the sense that the all or at least some of: a) the first agent, b) the diacid or its anhydride and c) the second agent are mixed directly before that a substantial reaction takes place.

In the first of the above described methods of according to the invention, the diacid or its anhydride is made react first with the first agent in a relationship (A: (x-M)) between 0.25: 1.00 and 1.50: 1.00 a a temperature between 140 ° C and 200 ° C to form a grafted diacid or its anhydride. After that, (in a second step) the second agent is added in such quantity that the ratio molar of the second agent to diacid or its anhydride is ≥ 0.6, preferably ≥ 1, and more preferably ≥ 2. This second step is conducted at a temperature between 120 ° C and 260 ° C in the case of alcohol; however, when the preparation of a grafted auto-stainless polyester resin (when the second agent is dialkanolamine) then the second step can be conducted at a temperature below 120 ° C and 180 ° C A self-grafted polyester resin grafted by polycondensation with water that is removed by distillation azeotropic or vacuum. It has been found that when used alcohol in the reaction, in most cases the second step can be advantageously conducted at a relatively high temperature  between approximately 200 ° C and 260 ° C, which leads to an adequate reaction time.

Preferably, the diacid or its anhydride is reacts first with the first agent in a relationship (A: (x-M)) between 0.25: 1.00 and 1.50: 1.00 a a temperature between 140 ° C and 200 ° C to form a diacid grafted or its anhydride, after which, in a second step, it add the second agent in such quantity that the molar ratio of the second agent to the diacid or its anhydride is ≥ 0.5, at a temperature between 120 ° C and 260 ° C, so that a Polyester condensed auto-stainless polyester resin.

In the second of the above described methods of according to the invention, the diacid or its anhydride (A), the second agent and the first agent (M) are reacted simultaneously to a temperature between 120 ° C and 180 ° C. Water is removed by azeotropic distillation or vacuum, and the molar ratio of second agent to the diacid or its anhydride is ≥ 0.5, preferably ≥ 1 and more preferably ≥ 2, and wherein the ratio of the diacid or its anhydride to the first agent (A: (x-M)) is between 0.25: 1.00 and 1.50: 1.00.

Preferably, the diacid or its anhydride, the second agent and the first agent are reacted simultaneously at a temperature between 120 ° C and 180 ° C, where the molar ratio of the second agent to the diacid or its anhydride is ≥ 0.5, and where the ratio (A: (x-M)) is between 0.25: 1.00 and 1.50: 1.00.

Alternatively, the diacid or its anhydride, the second agent and the first agent are reacted simultaneously at least partly at a temperature between 90 ° C and 120 ° C in the presence of a catalyst, where the molar ratio from the second agent to the diacid or its anhydride is ≥ 0.5 and in where the relationship (A: (x-M)) is between 0.25: 1.00 and 1.50: 1.00.

The polyester resin production method grafted stainless steel according to the invention comprises additionally the step of adding a protective fatty acid terminal. Preferably the terminal protection fatty acid is add before the start of the ester reaction, and more preferably the terminal protection fatty acid is added before the start of the graft reaction.

The terminal protection reaction may have place after the reaction between the diacid or its anhydride and the second agent or at least partially simultaneous with the reaction between the diacid or its anhydride and the second agent. Is very preferred to have the terminal protection reagent already in mind during the graft reaction and also during the reaction between the diacid or its anhydride and the second agent, since the reagent terminal protection will then act as a stabilizer of the temperature during exothermic grafting and reactions of formation of ester and / or amide groups.

In one embodiment, the polyester resin grafted auto-stainless or one or more of its constituents are made react with a terminal protective fatty acid or other agent of scanning of OH groups to obtain a low OH value or increase the average molecular weight

Especially in the case of resins of grafted autooxidable polyesteramide was found that the terminal protection by fatty acids of hydroxyl groups is a very suitable way of reducing the number of hydroxyl groups free, since the reduction in hydroxyl number is accompanied by an increase in molecular weight without substantial increase in system viscosity In addition, the reduction of the hydroxyl number terminal protection with fatty acid is a very advantageous way of decrease in the initial drying time of a composition of coating comprising the auto-stainless polyester resin grafted according to the invention.

With respect to the OH value, the polyester resin grafted stainless steel that has alcohol as a second agent is much more flexible than hyperbranched polyesteramides than they have dialkanolamine as a second agent, in the sense that the polyester resin according to the present invention which is Alcohol-based does not require very low OH values that are required by hyperbranched polyesteramides based on dialkanolamine necessary to prevent amine formation secondary leading to delay of the curing process by oxidation. It should therefore be noted that for the part of the grafted autooxidable polyester resins in accordance with the invention, part that does not comprise at all or substantially Amine groups, a low number of groups is not required hydroxy available to prevent yellowing.

The diacid or its anhydride and the second agent are they react further with a protective fatty acid terminal, where the terminal protective fatty acid is an acid unsaturated carboxylic (C10-C28) aliphatic, is that is, a carboxylic acid having 10 to 28 carbon atoms. Be prefer that the terminal protection fatty acid have one or more additional functional groups, such as links doubles or other acid groups. This makes possible the introduction of more functional groups in the auto-polyester polyester resin grafted The terminal protection fatty acid is an acid C10-C28 unsaturated carboxylic aliphatic, optionally with two, three or more double bonds.

Examples of terminal protection fatty acids Suitable include unsaturated carboxylic acids such as acid Dehydrated castor oil, linoleic acid and / or acid fatty linolenic Examples of useful fatty acids from natural oils they are taloyl fatty acid, sunflower oil fatty acid, acid fatty corn oil, cotton oil fatty acid, acid peanut oil fatty, flaxseed oil fatty acid, fatty acid from soybean oil, rapeseed oil fatty acid, acid fatty rice bran oil, fatty acid oil Safflower and / or sesame oil fatty acid. Can be used also mixtures of unsaturated fatty acids, as well as agents of swept.

The hydroxy groups of the second agent can be terminally protected by a fatty acid or an agent of scanning to facilitate resin curing as set forth previously. A sweeping agent is understood herein as a compound that will block or eliminate the OH group.

Examples of sweeping agents are fatty acids or polymers with acid functionality or molecules such as polyesters, carboxylic acids or organic oil residues; such anhydrides as acetic anhydride, phthalic anhydride, anhydride hexahydrophthalic, succinic anhydride, maleic anhydride or anhydride trimellitic; isocyanates such as cyclohexyl isocyanate, toluene diisocyanate, isophorone diisocyanate, hexane diisocyanate; small organic acids such as acetic acid and / or benzoic acid.

In another embodiment, the extension of protection terminal of the hydroxy group of the second agent can also be substantially less than 100% of the hydroxy groups. In that case, the hydroxy groups of the second agent can be treated with an agent additional scan to adjust the average functionality of the resin or to increase the overall average molecular weight. By agent OH scanning is understood herein as a compound that will block or delete the OH group. The term sweeping agent of Additional OH refers to a fatty acid can be considered as a sweeping agent of OH by way of terminal protection reaction.

Preferably, the production method of the polyester fibers according to the invention comprises additionally the step of adding an OH sweeping agent additional to react with the OH groups of the polyester or the first agent such that the OH groups are blocked or eliminate. Preferably, the OH scanning agent is a acid.

       \ vskip1.000000 \ baselineskip
    

Fatty acid or other sweeping agents may be added at various moments of the synthesis of the polyester resin grafted stainless steel according to the invention. It's possible:

to)

use fatty acid as a temperature buffer for the exothermic grafting and / or for the reaction of the ester and / or for the reaction of the amide by having it present in the reaction mixture when the graft reaction begins and / or when the ester reaction;

b)

add fatty acid after polyester resin formation grafted auto-stainless; or

C)

react the fatty acid with the second agent before mixing and reaction of the second agent with the diacid or its anhydride.

       \ vskip1.000000 \ baselineskip
    

Of these possibilities, option a) is the most preferred, since this allows improved process control during exothermic reactions without solvent addition or diluents, which have to be removed later in the process.

Another aspect of the invention concerns a grafted auto-stainless polyester resin that can be obtained by the method according to the invention. A resin of this type is extremely advantageous for various applications, such as lubricants, adhesives or coatings with high contents of solid.

Other aspects of the invention concern the use of the grafted auto-stainless polyester resin of the invention in a coating, particularly the use in a composition of oxidation drying coating with high content of solid. This use is particularly advantageous, since the resin grafted auto-stainless polyester according to the invention allows a relatively high molecular weight and ratio high oil / resin while maintaining a viscosity surprisingly low. This leads again to a decrease in the initial drying time as well as a drying time in reduced depth

A coating composition comprises typically several resins, additives, solvents, etc. The Properties are the result of the combination of the components. By the replacement of even a small fraction of a resin traditional, such as a polyester resin component or a alkyd resin component, with an equivalent amount of the polyester resin according to the invention, could be seen influenced the overall properties of the composition of coating. This is due to the special characteristics of the grafted auto-stainless polyester resin according to the invention determined by the Diels-Alder adduct. For the Traditional polyester resins, alcohol and acid recover normally in deesterification; instead, for the resin polyester according to the invention, in deesterification alcohol can only be recovered in the initial form, in so much that the acids will remain attached to the fatty acid forming a Diels-Alder adduct. This is a feature. special grafted auto-polyester polyester resin according with the invention

Since traditional resins have properties relatively close to environmental requirements expected in relation to solvent content, an addition of a portion as small as 5% by weight of the resin or component of resin according to the invention may in some cases be enough for the traditional coating composition to adjustment to the requirements of the content legislation under solvent by decreasing the viscosity of the composition of coating for the same molecular weight or even a weight higher average molecular. The minimum amount of polyester resin grafted stainless steel according to the invention which can be used in a traditional coating composition will be even less than 5% by weight, since it depends on the formulation and required final properties of the coating composition. For this reason, even relatively low resin contents grafted auto-stainless polyester according to the invention are very advantageous technically and commercially.

Preferably, the coating composition comprises at least 5% by weight of the polyester resin according to the invention. Also very advantageous compositions of coating with higher polyester resin contents grafted auto-stainless, such as more than 10% by weight of the resin, more than 20% by weight of the resin, more than 50% by weight of the resin or even more than 75% by weight of the resin, or substantially only grafted auto-stainless polyester resin in accordance with the invention.

Preferably, the coating composition comprising a self-etched polyester resin grafted onto the which resin can be obtained by a method according to the invention, wherein step a) comprises grafting of at least 5% in weight of a diacid or its anhydride in a first agent, and where the first agent comprises unsaturated oils selected from the group consisting of soybean oil, tung oil, oil Marigold, taloil, rosin, sunflower oil, castor oil dehydrated, flaxseed oil, corresponding fatty acids, and corresponding esters, and mixtures thereof.

For maximum quantities of polyester resin grafted auto-stainless, solvent content can be reduced much more than what is required by current (European) legislation and in some cases coating compositions may be formulated solvent-free solvent-based in accordance with this invention, which lead to a substantial environmental advantage of the invention.

In a preferred embodiment, the composition of coating comprising grafted auto-stainless polyester resin It has an initial drying time as measured by the adhesion of branch cotton less than 5.5 hours and a VOC <100 g / l for an application viscosity of polyester resin grafted stainless steel less than 5.0 Pa.s, measured at a rate of shear of 5,000 s -1 at 23 ° C.

The situation with the addition of a quantity relatively low resin according to the invention in a coating composition corresponds to what could be designated as external mixing of resins, in the sense that grafted self-oxidizing polyester resins used in coating compositions having a low content of grafted auto-stainless polyester resin would typically have a very high degree of grafting and may also have a very high degree terminal protection of fatty acids.

Another type of mixing can be designated as internal mixing This type represents the situation in which a substantial amount of the diacid or its anhydride are not grafted in the first agent and / or a substantial fraction of the groups Hydroxy of the second agent are not protected by a fatty acid. The non-grafted diacid or anhydride can be for example of a type that cannot participate in the graft reaction or the Resin formulation may be deficient in the first agent. This makes possible a very fine adjustment means to control the properties of grafted auto-stainless polyester resin, such such as viscosity, average molecular weight, initial drying time and deep drying time of a coating composition which comprises the resin according to the invention.

When internal mixing is applied, it is preferred that the grafted auto-stainless polyester resin comprises at least 5% by weight of the diacid or its anhydride grafted into a first agent. This first agent should comprise a first series of links double conjugates or a first allyl hydrogen and at least one additional functionality selected from the group consisting of a series of conjugated double bonds, allyl hydrogen, bonds unconjugated doubles, OH group, COOH group and amino group. In addition, the first agent is preferably selected from the group constituted by fatty acids, fatty acids and modified oils, such as soy fatty acid, taloyl fatty acid, tung oil and / or rosin.

       \ vskip1.000000 \ baselineskip
    

Illustrative examples of reactions and structures preferred

He passed to)

Reaction between a diacid or its anhydride with a first agent

A very preferred embodiment is the case in which The diacid is maleic anhydride:

       \ vskip1.000000 \ baselineskip
    

eleven

       \ vskip1.000000 \ baselineskip
    

and the first agent is oil from tung that contains a lot of fatty acid Eleostearic:

       \ vskip1.000000 \ baselineskip
    

12

       \ vskip1.000000 \ baselineskip
    

where R represents the rest (other branches) of the first agent (in this case oil from tung)

       \ newpage
    

The maleic anhydride is grafted in step a) of the method of the invention to tung oil by reaction Diels-Alder leading to the anhydride adduct grafted maleic:

       \ vskip1.000000 \ baselineskip
    

13

       \ vskip1.000000 \ baselineskip
    

The adduct resulting from the reaction in step a) described above will react further (in step b)) with the Second agent

       \ vskip1.000000 \ baselineskip
    

       \ vskip1.000000 \ baselineskip
    

       \ vskip1.000000 \ baselineskip
    

(Scheme turns to page next)

       \ newpage
    

He passed b)

Reaction between the Diels-Alder adduct from step a) and the second agent i) Reaction with alcohol as a second agent

In a preferred embodiment, the alcohol is glycerol (CH 2 OHCHOHCH 2 OH), and the reaction between glycerol and maleic anhydride grafted with tung oil as prepared above is therefore:

       \ vskip1.000000 \ baselineskip
    

14

       \ vskip1.000000 \ baselineskip
    

The reactions with the second acid part of grafted maleic anhydride or reaction with the other groups Alcohol hydroxy are not shown for simplicity reasons. Similarly, R, which represents the other branches of fatty acid (first agent) is not shown for simplicity. These other branches can be grafted analogously with maleic anhydride or react otherwise with the same molecule or neighboring molecules, for example as indicated below. The resulting molecule it can be protected terminal afterwards for example with fatty acid or reacted with functional polymers acid or molecules such as polyesters, carboxylic acids or moieties Organic oil If the first agent also includes groups acids, such as in the case where the first agent is a carboxylic acid, then each of these acid groups can react with other molecules or internally with, by example, OH groups of the same molecule.

       \ newpage
    

The final structure of the polyester resin grafted auto-stainless can be represented for example by the following structure, where in this example the alcohol is glycerol:

       \ vskip1.000000 \ baselineskip
    

fifteen

       \ vskip1.000000 \ baselineskip
    

Note: The two possible positions of the remains linoleic are random as a result of selectivity randomization of the Diels-Alder addition towards the three conjugated double bonds of the eleostearic remains.

In this structure, R 1, R 2, R 3, R 4, R 5 and R 6 are parts of tung oil; R 7, R 8 and R 9 are fatty acids with ester, chain bonds polyester and / or hydrogen. If the terminal protection groups are fatty acids with ester bonds, oil molecules or other entity, that can also act as a first agent, one or more of these groups may be grafted to other sites of the same molecule or from neighboring molecules. R 10 represents a glycerol moiety with ester links.

If the terminal protection groups are acidic fatty with ester bonds, oil molecules or other entity, which can also act as a first agent, one or more of these groups may be grafted to other sites of the same molecule or of neighboring molecules.

       \ newpage
    

ii) Reaction with dialkanolamine as the second agent

In a very preferred embodiment, the dialkanolamine is diisopropanolamine, and the reaction between diisopropanolamine and maleic anhydride grafted with oil Tung prepared as shown in step a) is by consequent:

       \ vskip1.000000 \ baselineskip
    

16

       \ vskip1.000000 \ baselineskip
    

The reaction with the second acidic part of the grafted maleic anhydride is not shown for reasons of simplicity. Similarly, R, which represents the rest (other branches) of the fatty acid is not shown because of simplicity. These other branches can also be grafted with maleic anhydride or otherwise react with the same molecule or neighboring molecules for example as indicated below. The resulting molecule can be terminally protected thereafter for example by fatty acid or reacted with acid functional polymers or molecules such as polyesters, carboxylic acids or organic oil residues. If the first agent also comprises acid groups, such as in the case where the first agent is a carboxylic acid, then each of these acid groups can react with other molecules or internally, for example with OH groups thereof.
molecule.

       \ newpage
    

The final resin structure of grafted auto-stainless polyesteramide can be represented by example by the following structure:

       \ vskip1.000000 \ baselineskip
    

17

       \ vskip1.000000 \ baselineskip
    

Note: The two possible positions of the remains linoleic are random as a result of selectivity randomization of the Diels-Alder addition towards the three conjugated double bonds of the eleostearic remains.

In this structure presented above, R_ {1}, R 2, R 3, R 4, R 5 and R 6 are parts of oil of tung; R 7, R 8 and R 9 are fatty acids with bonds ester, polyester chain and / or OH groups. X can be analogously terminal protected parts of diisopropanolamine as has been previously described, or may comprise connections with others molecules such as diacids and oil molecules, molecules of fatty acid or polymers. If the terminal protection groups are fatty acids with ester bonds, oil molecules or other entity, which can also act as a first agent, one or more of these groups can be grafted to other sites in it molecule or neighboring molecules.

The invention will be illustrated with reference to the following non-limiting examples.

       \ vskip1.000000 \ baselineskip
    

Example one

Resin preparation (Resin I)

177 g of tung oil and 722 g of fatty acid of taloil were loaded into the reactor and heated to 120 ° C. TO 120 ° C, 50 g of maleic anhydride was dosed in the reactor. Be detected a slight exotherm to approximately 145 ° C. The temperature rose to 160 ° C under reflux conditions. After 1 hour at 160 ° C, 102 g of glycerol and 40 g of were loaded into the reactor xylene. The reactor temperature was raised to 245 ° C and a  distillation under azeotropic conditions until the acid value It was <16 mg KOH / g resin. At 220 ° C, the xylene was released in vacuum conditions After the xylene had come off, the resin was diluted to 90% solids with Exxsol D40 (fluid hydrocarbon from ExxsonMobil Chemical).

After that the resin was discharged. The weight molecular average number Mn was 1802 g / mol and molecular weight weight average Mw was 10,664 g / mol, as established by the Gel Permeation Chromatography (GPC) technique as determines in an instrument Alliance Waters 2695 GPC with three consecutive PL-gel columns, type Mixed-B, l / d = 300 / 7.5 mm (Polymer Laboratories) using stabilized tetrahydrofuran (THF) (stable BHT) as eluent at 1 ml / min, at 40 ° C and using an index detector of Alliance Waters 2410 refraction. A series of standards were used of polystyrene to calibrate the GPC equipment.

       \ vskip1.000000 \ baselineskip
    

Example 2

Resin preparation (Resin II)

169 g of tung oil and 691 g of Taloyl fatty acid in the reactor and heated to 120 ° C. TO 120 ° C, 48 g of maleic anhydride were dosed in the reactor. Be detected a slight exotherm to approximately 145 ° C. The temperature rose to 160 ° C under reflux conditions. After 1 hour at 160 ° C 141 g of diisopropanolamine were charged to the reactor and 40 g of xylene, and distillation was performed under conditions azeotropic until the acid value was <16 mg KOH / g of resin, and the xylene was removed under vacuum conditions. After that all xylene had come off, the resin was diluted until 90% solids with Exxsol D40.

After that the resin was discharged. The pesos Molecular media were established by the chromatography technique by Gel Permeation; the Mn was 2037 g / mol and the Mw was 26,068 g / mol

       \ vskip1.000000 \ baselineskip
    

Example 3 (resin comparative)

Resin preparation (Comparative Resin III)

29 g of acid were charged to the reactor isophthalic, 151 g of pentaerythritol, 1065 g of fatty acid taloil, 30 g of maleic anhydride and 50 g of xylene, and heated to 230 ° C under azeotropic conditions until the acid value was <16 mg KOH / g resin. At 200 ° C, the xylene was released in vacuum conditions After all the Xylene, the resin was diluted to 90% solids with Exxsol D40.

After that the resin was discharged. The pesos Molecular media were established by the chromatography technique by Gel Permeation; the Mn was 1800 g / mol and the Mw was 4556 g / mol

The resin still contained an amount important unreacted maleic anhydride, which was visible by needle-shaped crystals This clearly demonstrates that the increase in molecular weight by use of maleic anhydride no It took place completely as planned. This is expressed also for the relatively low Mw.

       \ vskip1.000000 \ baselineskip
    

Example 4

Preparation of the coating composition 1

Coating composition 1 was obtained mixing with a normal laboratory stirrer 25 g of resin as that obtained in Example 1 with 1.44 g of Nuodex Ca 5 (Elementis), 0.21 g of Nuodex Co 10 (Elementis), 1.1 g of Nuodex Zr 12 (Elementis) and 0.25 g of Exkin 2 (Elementis). Nuodex Co 10, Nuodex Zr 12 and Nuodex Ca 5 are desiccant salts. Exkin 2 is an agent anti-skin

       \ vskip1.000000 \ baselineskip
    

Example 5

Preparation of the coating composition 2

The coating composition 2 was obtained mixing with a normal laboratory stirrer 25 g of resin as that obtained in Example 2 with 1.44 g of Nuodex Ca 5 (Elementis), 0.21 g of Nuodex Co 10 (Elementis), 1.1 g of Nuodex Zr 12 (Elementis) and 0.25 g of Exkin 2 (Elementis).

       \ vskip1.000000 \ baselineskip
    

Example 6 (coating comparative)

Preparation of the comparative coating composition 3

The coating composition was obtained comparative 3 mixing with a normal laboratory shaker 80 g resin as obtained in Example 1 with 1.44 g of Nuodex K5 (Elementis), 0.21 g of Nuodex Co 10 (Elementis), 1.1 g of Nuodex Zr 12 (Elementis) and 0.25 g of Exkin 2 (Elementis).

       \ vskip1.000000 \ baselineskip
    

Application tests

From a practical point of view, it makes sense discriminate between three stages of drying. The first stage of drying it ends when autoxidation results in solidification from the surface of the film. The exact moment of the Surface solidification is quantified by the Test Adhesion of Cotton on Branch.

The adhesion test of branch cotton measures the surface drying rate of a coating film. He adhesion test of branch cotton was performed on a film coating applied with a 100 µm slit applicator on a glass plate. After applying the composition of lining, a sample of cotton on branch was dropped (a loose ball of approximately 0.2 g and with a diameter of approximately 3 cm) from a height of 5 cm on the film of painting. After 10 seconds, the glass panel turned 180º and it was observed if the branch cotton falls without leaving cotton fibers on the surface. When the branch cotton did not stick to the surface, time was noted.

The second drying stage is terminated when the coating film has solidified throughout its film height The drying stage must be completed in order to get anti-lock properties. This solidification "in depth "of the coating film is quantified by the Indentation test.

The degree of deep cure was measured in function of drying time on a coating film applied to a glass plate with a 200 slit applicator \ mum. The glass plate was arranged on the bottom plate of a Physica MCR 301 rheometer. Subsequently, a rod-shaped indenter with a diameter of 3.5 mm over the paint film with a force of 20N. While the part bottom of the paint film was not sufficiently cured to resist the applied weight, it was squeezed between the Indenter and glass plate. The distance between the tip of the indenter and the glass plate that remains after pressing for 5 minutes it was used as a measure of deep drying. The greater this distance, the better the drying in depth. The test was performed at 23 ° C.

The test results, both of the drying of the Branch cotton as indentation, are presented below in Table 1

Viscosity values were measured with a Physica MCR301 rheometer using a cone measurement system and plate characterized by a cone diameter of 25 mm and an angle of 1st cone. Flow curves were measured at a temperature of 23 ° C depending on the shear rate, starting at a rate of 5,000 s -1. Within a time interval of 90 s subsequently, the shear rate was gradually reduced up to 1 s -1, followed immediately by a gradual increase in the shear rate up to 5,000 s -1. It is considered that the viscosity measured within the range of shear rates of 20-40 s -1 is responsible for the resistance of the drip paint from the brush. It is considered that the viscosity measured at a shear rate of 5,000 s -1 is responsible for the "brush resistance" experienced during paint application (= application viscosity). Be considers the viscosity measured at a shear rate of 1 s ^ 1 is responsible for "buckling resistance" experienced after the application of the paint.

Viscosity results are presented at continued in Table 1.

From the examples described above and the test results for coating 1 (Example 4), coating 2 (Example 5) and for comparative coating 3 (Example 6) presented in Table 1 can be deduced that it is difficult to prepare a resin by the traditional route as described in Comparative Example 3 with a molecular weight Mw as high as for polyester resins according to the invention prepared as described in Examples 1 and 2. Therefore, this route traditional leads to lower molecular weights that give as result in a longer drying time and less deep drying after 20 hours of drying.

The low viscosity obtained for the composition Comparative coating 3 can be explained by the low weight molecular weight average and the low number average molecular weight that characterize the comparative coating composition 3. In comparison, the coating compositions 1 and 2 prepared from according to the method of the invention, which although had a weight low molecular number average had a medium molecular weight weight much higher than the coating composition 3, and they still had low viscosities.

TABLE 1

18

Claims (20)

1. A method for preparing a resin grafted auto-stainless polyester in which the resin is obtained by steps that include:

to)

graft at least one diacid or its anhydride into a first agent by a Diels-Alder and / or Jan reaction; Y

b)

react the product from step a) with a second agent;

where the first agent comprises at least a first functionality selected from a group consisting of a first series of conjugated double bonds or a first allyl hydrogen;

where the diacid or its anhydride and the second agent are reacted further with a fatty acid of terminal protection, where the terminal protection fatty acid it is an unsaturated carboxylic acid (C10-C28); wherein the first agent comprises at least one additional functionality selected from the group consisting of a series of conjugated double bonds, allyl hydrogen, double bond unconjugated, OH group, COOH group and amino group; where the second agent is selected from group consisting of alcohol with a medium hydroxyl functionality numerical> 2.0, dialkanolamine or mixtures thereof; Y where the auto-polyester polyester resin grafted has an oil / resin ratio ≥ 80, a weight molecular average number Mn? 1000 g / mol and a PDI? 3.

         \ vskip1.000000 \ baselineskip
      

2. A method according to claim 1, wherein the diacid or its anhydride comprises at least 80% of the molar amount of diacid or its anhydride selected from the group consisting of maleic acid, maleic anhydride, itaconic acid, fumaric acid or mixtures thereof. 3. A method according to any one of claims 1 or 2, wherein the first agent is selected of the group consisting of unsaturated fatty acids, fatty acids and modified oils and mixtures thereof. 4. A method according to any one of claims 1 to 3 wherein the first agent comprises the minus an eleostearic remainder. 5. A method according to any one of claims 1 to 3, wherein the first agent comprises the minus two series of conjugated double bonds. 6. A method according to any one of claims 1 to 5, wherein the first agent comprises the minus 80% by weight of unsaturated oils selected from the group consisting of soybean oil, tung oil, oil Marigold, taloil, rosin, sunflower oil, castor oil dehydrated, flaxseed oil, corresponding fatty acids, corresponding esters, and mixtures thereof. 7. A method according to any one of claims 1 to 6, wherein the second agent is alcohol with a numerical average hydroxyl functionality> 2.0. 8. A method according to any one of claims 1 to 7, wherein the second agent in the case of an alcohol comprises at least 50% by weight of an alcohol with a hydroxy functionality ≥ 3.

         \ vskip1.000000 \ baselineskip
      

9. A method according to any one of claims 1 to 6 wherein the second agent in the case of a dialkanolamine is

         \ vskip1.000000 \ baselineskip
      

twenty

         \ newpage
      

in where

         \ vskip1.000000 \ baselineskip
      

twenty-one

         \ vskip1.000000 \ baselineskip
      

in whose formula R 1, R 2, R 3, R 4, R 5 and R 6 may, independently of each other,  be the same or different, H or C1-C4-alkyl.

         \ vskip1.000000 \ baselineskip
      

10. A method according to claim 9, wherein the dialkanolamine comprises at least 80% by weight of diisopropanolamine.

         \ vskip1.000000 \ baselineskip
      

11. A method according to any one of claims 1 to 10, wherein the relationship (A: (x-M)) is between 0.25: 1.00 and 1.50: 1.00, where A = the molar amount of the diacid or its anhydride, M = the molar amount of the first agent, and x = the graft functionality of the first agent.

         \ vskip1.000000 \ baselineskip
      

12. A method according to any one of claims 1 to 11, wherein the molar ratio of the second diacid agent or its anhydride is ≥ 0.5. 13. A method according to any one of claims 1 to 12, wherein the diacid or its anhydride is reacts first with the first agent in a relationship (A: (x-M)) between 0.25: 1.00 and 1.50: 1.00 a a temperature between 140 ° C and 200 ° C to form a grafted diacid or its anhydride, after which, in a second step, it is added the second agent in an amount such that the molar ratio of second agent to the diacid or its anhydride is ≥ 0.5 to a temperature between 120ºC and 260ºC, obtaining a polyester resin stainless steel grafted by polycondensation. 14. A method according to any one of claims 1 to 12, wherein the diacid or its anhydride, the second agent and the first agent are reacted simultaneously at a temperature between 120 ° C and 180 ° C, where the molar ratio of the second agent to the diacid or its anhydride is ≥ 0.5 and where the ratio (A: (x-M)) is between 0.25: 1.00 and 1.50: 1.00. 15. A method according to claim 14, wherein the diacid or its anhydride, the second agent and the first agent are reacted simultaneously at least in part at a temperature between 90 ° C and 120 ° C in the presence of a catalyst, wherein the molar ratio of the second agent to diacid or its anhydride is ≥ 0.5 and where the ratio (A: (x-M)) is between 0.25: 1.00 and 1.50: 1.00. 16. A grafted auto-stainless polyester resin which can be obtained by a method according to any one of claims 1 to 15. 17. Use of the resin according to the claim 16 in a coating composition with high solids content. 18. A coating composition that It comprises at least 5% by weight of the resin according to the claim 16. 19. A coating composition that it comprises a grafted auto-stainless polyester resin where the resin can be obtained by a method according to any one of claims 1 to 15, wherein step a) comprises graft at least 5% by weight of a diacid or its anhydride on a first agent, and wherein the first agent comprises oils unsaturated selected from the group consisting of soybean oil, tung oil, marigold oil, taloil, rosin, oil sunflower, dehydrated castor oil, flaxseed oil, acids corresponding fats, corresponding esters, and mixtures of the same. 20. A coating composition that it comprises a grafted auto-stainless polyester resin where the resin can be obtained by a method according to any one of claims 1 to 15, said composition having coating an initial drying time, as measured by a test of adhesion of branch cotton, less than 5.5 hours and a VOC of <100 g / l for a resin application viscosity grafted auto-stainless polyester less than 5.0 Pa.s measured at one shear rate of 5,000 s -1 at 23 ° C.