WO2018032388A1

WO2018032388A1 - Herbicide composition comprising clomazone and use thereof

Info

Publication number: WO2018032388A1
Application number: PCT/CN2016/095620
Authority: WO
Inventors: Yifan Wu; James Timothy BRISTOW
Original assignee: Jiangsu Rotam Chemical Co Ltd
Current assignee: Jiangsu Rotam Chemical Co Ltd
Priority date: 2016-08-17
Filing date: 2016-08-17
Publication date: 2018-02-22
Anticipated expiration: 2019-02-17
Also published as: EP3500103A4; CN109561695A; GB2567098B; GB2567098A; EP3500103A1; GB201901568D0

Abstract

A microcapsules polymer skin material comprising crosslinked polyepoxide – polyurea co-polymer and its preparation, as well as a composition comprising a water-immiscible material or high volatile material encapsulated within a microcapsule having a wall comprising the microcapsules polymer skin material, and the use of the composition in the control of unwanted plant growth are provided.

Description

HERBICIDE COMPOSITION COMPRISING CLOMAZONE AND USE THEREOF

BACKGROUND OF THE INVENTION

Field of Invention

This invention concerns an improved microcapsules polymer skin material consisting of crosslinked polyepoxide –polyurea co-polymer and its preparation.

Description of Related Art

Capsules of this character have a variety of uses, as for containing dyes, inks, chemical reagents, pharmaceuticals, flavoring materials, pesticides, herbicides and the like. Once encapsulated, the liquid or other form is preserved until it is released by some means or instrumentality that breaks, crushes, melts, dissolves, or otherwise removes the capsule skin or until release by diffusion is effected under suitable conditions. The process of the invention is particularly suitable for the production of water-immiscible material containing microcapsules of very small particle size, suspended in an aqueous solution.

Aqueous dispersions of water-immiscible material microcapsules are particularly useful in controlled release water-immiscible material formulations because they can be diluted with water or liquid fertilizer and sprayed using conventional equipment, thereby producing uniform field coverage of the water-immiscible material. Additives such as film forming agents can be added directly to the finished formulation to improve the adhesion of microcapsules to foliage. In some cases, reduced toxicity and extended activity of encapsulated water-immiscible material have been noted.

Various methods of encapsulation by interfacial condensation between direct-acting, complimentary reactions are known. Within these methods are reactions for producing various types of polymers as the capsule walls. Many of such reactions to produce the coating substance occur between an amine, which must be of at least bifunctional character and a second reactant intermediate, which for producing a polyurea is a bifunctional or polyfunctional isocyanate. The amines chiefly used or proposed in these methods are typified by ethylene diamine, having at least 2 primary amino groups. U.S. Pat. No. 3,577,515 is illustrative of encapsulation by interfacial condensation.

SUMMARY OF THE INVENTION

The present invention provides a new and improved encapsulation process which is rapid and effective and which avoids the necessity of separation of the encapsulated material from the continuous phase material. The present invention also eliminates the need for using a strong solvent in the organic phase resulting in a savings of energy, and packaging and equipment ware. In addition, direct combination of water-based herbicide and pesticide formulations are possible with other water-based pesticides.

The compositions of the present invention are particularly suitable for the formulation of water immiscible material and high volatile material, such as clomazone, abamectin, pendimethalin, lambda cyhalothrin, spinosad, emamectin benzoate, deltamethrin, cypermethrin, acetochlor, alachlor, metolachlor and their mixtures. Experiments indicate that conventional oil/water herbicide emulsifiers fail to produce sufficiently stable emulsions to attain microencapsulation of concentrated amounts of herbicide materials and avoid solidification of the oil/water mass when amine is added. Additionally, attempts to encapsulate concentrated amounts of active ingredient using traditional interfacial polymerization techniques, as for example that disclosed in U.S. Pat. No. 3,577,515, have resulted in unsatisfactory formulations because of the problem of herbicide crystal growth, as well as agglomeration or solidification of the finished suspensions. It is thought that herbicide crystal growth results from either incomplete encapsulation of the herbicidal material or the passage of small amounts of herbicide through the polymeric shell wall.

It is accordingly a particular object of this invention to provide a process whereby greater than 480 grams of water immiscible material, is encapsulated in a crosslinked polyepoxide –polyurea copolymer shell wall with the finished microcapsules being suspended in the original aqueous solution. The suspended microcapsules may be stored for extended periods of time and may be exposed for short-terms to elevated temperatures without the occurrence of agglomeration or solidification of the aqueous, capsule mass or herbicide crystal formation.

DETAILED DESCRIPTION OF THE INVENTION

This invention concerns an improved microcapsules polymer skin material consisting of crosslinked polyepoxide –polyurea co-polymer and its preparation. The preferred polyepoxide in this invention is diglycidyl ether of biphenyl-A (DGEBA) and its derivative. Amine terminated or isocyanate terminated diglycidyl ether of biphenyl-A (DGEBA) prepolymers can be prepared first. Amine terminated DGEBA will form polyepoxide -polyurea copolymer with polyfunctional isocyanate. While isocyanate terminated DGEBA will form polyepoxide -polyurea copolymer with polyfunctional amine.

In this invention, a water-immiscible (organic) phase, which consists of a water-immiscible material (the material to be encapsulated) and diglycidyl ether of biphenyl-A (DGEBA) prepolymers, is added to an aqueous phase, with agitation, to form a dispersion of small droplets of the water-immiscible phase within the aqueous phase. Thereafter, a polyfunctional amine, preferably 1,6-hexamethylene diamine or polyfunctional isocyanate, preferably, polymethylene polyphenyl isocyanates, PMPPI is added, with continued agitation, to the organic/aqueous dispersion. The polyfunctional amine or isocyanate reacts with diglycidyl ether of biphenyl-Aprepolymers to form a capsular polyepoxide –polyurea copolymer shell about the water-immiscible material.

The water-immiscible material referred to herein, is the material to be encapsulated, such as clomazone, abamectin, pendimethalin, lambda, spinosad, emamectin benzoate, deltamethrin, cypermethrin, acetochlor, alachlor, metolachlor and their mixtures and organic solvents, e.g., xylene and monochlorobenzene are specifically contemplated herein.

The material to be encapsulated utilizing the process of the present invention need not consist of only one type, but may be a combination of two or more various types of water-immiscible materials. For example, water-immiscible material can be a combination of different active herbicides； or herbicides and insecticides. Also contemplated is a water-immiscible material to be encapsulated which comprises an active ingredient, such as a herbicide, and an inactive ingredient, such as a solvent or adjuvant.

Amine terminated diglycidyl ethers of bisphenol A having formula (I) can be prepared by reaction of polyfunctional amines with the epoxy terminated derivatives of glycidyl ethers of bisphenol A as follows:

wherein N-R-N is polyamine, such as 1, 6-hexamethylene diamine； R'represents a glycidyl ether having the formula: (II)

wherein n'represents 0 or a positive number having a value of 0 to 25.

In accordance with the present invention, products that are useful in the preparation of epoxy resins are provided, such products constituting epoxy terminated derivatives of polyfunctional amine and diglycidyl ethers of bisphenol A, as hereinafter defined. The present invention is also directed to amine derivatives of the epoxy terminated derivatives of diglycidyl ethers of bisphenol A prepared by reacting polyfunctional amines, as hereinafter specified, with the epoxy terminated derivatives in the manner hereinafter described.

An advantage of both the epoxy terminated and the amine terminated derivatives of diglycidyl ethers of bisphenol is that the products are liquid at ambient temperatures and can be used as epoxy curing agents in preparing epoxy resins wherein added flexibility is an important property.

It has been discovered in accordance with the present invention that the solvent that should be used is either acetone or methyl ethyl ketone (MEK) .

If the symbol "E" represents a diglycidyl ether of bisphenol A, the symbol "A" and "A+" represents the polyfunctional amine, then the reactions and reaction products of the present invention can be visualized below:

As can be more easily seen from the foregoing, the process and products of the present invention provide an improvement in the act of preparing epoxy resins wherein a significant portion of the bisphenol A component is "prereacted" prior to the final epoxy resin formation step to liquid intermediates that are easy to prepare, easy to store and easy to use.

Key factors that are involved include the discovery that it is necessary to use either acetone or methyl ether ketone as a solvent in the process of the present invention and the discovery of the need to use a polyfunctional amine in the second step of the process.

Preparation of the amine derivatives of diglycidyl ethers of bisphenol A

In accordance with another embodiment of the present invention, an epoxy terminated derivative of bisphenol A as prepared in the manner just described, is further reacted with a polyfunctional amine such as 1, 6-hexamethylene diamine.

This can be accomplished by further adding to the reaction mixture described above about 4 moles or more, such as 4 to 10 moles of the polyfunctional amine per mole of said polyfunctional amine used in the preparation of the epoxy terminated diglycidyl ether. In this situation, the epoxy terminated diglycidyl derivative is, in effect, an intermediate reaction product and when mixed with the polyfunctional amine provides a second reaction mixture.

The second reaction mixture is heated at a temperature of about 100 ℃ to about 150 ℃. for about 0.5 to about 5 hours and thereafter a tetrafunctional amine derivative is recovered.

Preparation of the epoxy terminated derivatives of polyfunctional amine and diglycidyl ethers of bisphenol A

In accordance with the present invention, epoxy terminated diglycidyl ethers of bisphenol A is prepared by the following sequence:

A diglycidyl ether of bisphenol A having formula IX given above is dissolved in either acetone or methyl ethyl ketone. Acetone is the preferred solvent and gives the best results.

The thus prepared solution is added to a reaction vessel and a polyfunctional amine, such as 1, 6-hexamethylene diamine is added, the amount of polyfunctional amine added being such that there is provided about 4 to 5 moles of the diglycidyl ether per mole of polyfunctional amine. The preferred ratio is about 4.5 moles of the diglycidyl ether per mole of polyfunctional amine.

The thus formed reaction mixture is heated with agitation at a temperature within the range of about 80℃ to about 160℃. for about 1 to about 4 hours sufficient to permit the diglycidyl ether to quantitatively react with the polyfunctional amine and to substantially completely volatilize the ketone solvent initially charged to the reaction vessel. Thereafter, if desired, the epoxy terminated derivative can be recovered from the reaction mixture and will have a formula as given in formula I above.

In this invention, polyfunctional isocyanate is added into amine terminated DGEBA, which form polyepoxide -polyurea copolymer.

Isocyanate terminated diglycidyl ethers of bisphenol A which are prepared by reaction polyfunctional isocyanate with the epoxy terminated derivatives of glycidyl ethers of bisphenol A as follows；

This invention relates to a process for the preparation of crosslinked polymers by reacting epoxide compounds, containing at least two epoxide groups in the molecule, and polyisocyanates in the presence of catalysts, such as a complex compound of BF₃ with a compound of the group comprising ethers, phosphonium compounds and H₂O, if desired together with a compound of a metal of the group comprising Sn, Zn and Fe, which compound is soluble in the reaction mixture.

BF₃ complexes suitable as catalysts for the process according to the invention are, in particular, BF₃ etherates of cyclic ethers, such as tetrahydrofuran and tetrahydropyrane. Suitable complex compounds of BF₃ with phosphonium compounds are, for example, those based on triethyl phosphate and trimethyl phosphonate. Boron trifluoride dihydrate (BF₃.2H₂O) is also an effective curing agent for the reactants used according to the invention.

The compounds of the metals Sn, Zn and Fe, which can be admixed to the reaction mixture if desired, act as accelerators for the curing catalysts. The following compounds are suitable examples: dibutyl-tin dilaurate, Zn naphthenate, Zn octoate, Fe naphthenate and Fe octoate.

If, according to the invention, only 2 reactants, i.e., an epoxide compound containing at least two epoxide groups in the molecule and a polyisocyanate, are reacted, the ratio is so chosen that there are 0.1 to 2.0 and preferably 0.3 to 1.2 isocyanate groups per epoxide group and BF₃ of the curing catalyst presents in a concentration of 0.2％to 0.5％by weight, based on the amount of both reactants. If the reaction mixture additionally also contains a polyhydroxy compound (ternary system) , the ratios in respect of the epoxide compound and the polyisocyanate are the same as in the case of the binary systems according to the invention. The polyhydroxy compound is present in the system in a concentration such that there are 0.1 to 2.0 and preferably 0.2 to 1.0 OH groups per epoxide group. As in the case of the binary systems, BF₃ of the curing catalyst is contained in a concentration of 0.2％to 0.5％by weight, but in this case the percentages are based on the amount of all three reactants.

In the process according to the invention, the concentration of the Sn, Zn or Fe compound which is soluble in the reaction mixture is 0.0001％to 0.5％and preferably 0.0002％to 0.3％by weight in both binary and the ternary systems, the percentages being based on the amount of the 2 or the 3 reactants respectively.

In the case of ternary systems, the procedure can be for all 3 reactants to be present in the reaction mixture when the reaction is initiated. In principle, however, it is also possible to proceed stepwise； i.e., prepolymers of two reactants are first prepared and the reaction is then brought to completion after adding the third component.

It has been found that polyisocyanate prepolymers obtained from the reaction of di-or polyisocyanates with polyepoxides having no or low levels of hydroxy functionality at temperatures below about 100℃. In the absence of any catalyst contain both isocyanate and epoxide groups and these liquid prepolymers have long shelf stability. To illustrate, when a mixture of 80％-90％polyisocyanate (liquid methylene bis-phenyl isocyanate having an isocyanate equivalent weight of 144) and 10％-20％of a liquid diglycidyl ether of bisphenol-A (epoxy equivalent weight of 180-190) is heated at about 60℃ for about 3 hours, a liquid prepolymer is formed which has a shelf stability at room temperature of more than 2 months. This prepolymer, upon reaction with a polyol which contains a tertiary amine and cationic complex catalyst, results in the formation of a thermoset polymer which contains urethane, isocyanurate and oxazolidone linkages. Isocyanurate and oxazolidone groups in the polymer are believed to impart high heat deformation and thermal stability properties and the urethane linkages are believed to provide the toughness and flexibility to the polymer. In order to improve the impact strength of the thermoset polymer it is advantageous to add to the polymerization mixture soft segments such as a synthetic rubber.

The equivalent ratio of isocyanate to epoxy groups in the polyisocyanate-epoxy prepolymer compositions may be in the range of from 1: 0.001 to 1: 1 and preferably from 1: 0.05 to 1: 0.5. The reaction of polyisocyanate and polyepoxide to form a prepolymer can be carried out at temperatures in the range of from about room temperature to about 100℃. The equivalent ratio of isocyanate to combined epoxy and hydroxyl groups may be in the range of from 0.8: 1 to 3: 1. The suitable catalysts for the thermoset polymer formation include cationic catalysts, tetraalkyl ammonium salts, tertiary amines, titanium alkoxides, alkali and alkaline earth metal salts, boron trihalide-tertiary amine adducts, organotin compounds, and others known to those skilled in the art.

The prepolymers and the thermoset polymers of this invention can contain fillers, pigments, and the like which are well known to those skilled in the art.

The polymerization temperature used in the preparation of the thermoset polymers of this invention can range from about room temperature to about 200℃.

In this invention, polyfunctional amine is added into isocyanate terminated DGEBA, which form polyepoxide -polyurea copolymer.

The following epoxide compounds are particularly suitable for the process according to the invention: epoxidised diolefins, dienes or cyclic dienes, such as butadiene dioxide, 1, 2, 5, 6-diepoxyhexane and 1, 2, 4, 5-diepoxycyclohexane； epoxidised diolefinically unsaturated carboxylic acid esters, such as methyl 9, 10, 12, 13-diepoxystearate； the dimethyl ester of 6, 7, 10, 11-diepoxyhexadecane-1, 16-dicarboxylic acid； and epoxidised compounds containing two cyclohexenyl radicals, such as diethylene glycol bis- (3, 4-epoxycyclohexanecarboxylate) and 3, 4-epoxycyclohexylmethyl 3, 4-epoxycyclohexanecarboxylate.

Further compounds which can be used are polyglycidyl esters such as are accessible by reacting a dicarboxylic acid with epichlorohydrin or dichlorohydrin in the presence of alkali. Such polyesters can be derived from aliphatic dicarboxylic acids, such as oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid, and especially from aromatic dicarboxylic acids, such as phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, 2, 6-naphthylene-dicarboxylic acid, diphenyl-o, o'-dicarboxylic acid, ethylene glycol bis- (p-carboxyphenyl) ether and others.

Further compounds which can be used are polyglycidyl ethers such as are accessible by etherification of a dihydric or polyhydric alcohol or diphenol or polyphenol with epichlorohydrin or dichlorohydrin in the presence of alkali. These compounds can be derived from glycols, such as ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butylene glycol, pentane-1, 5-diol, hexane-1, 6-diol, hexane-2, 4, 6-triol and glycerol, and especially from diphenols or polyphenols, phenol novolacs or cresol novolacs, resorcinol, pyrocatechol, hydroquinone, 1, 4-dihydroxynaphthalene, phenol/formaldehyde condensation products, bis- (4-hydroxyphenyl) -methane (bisphenol F) , bis (4-hydroxyphenyl) -methylphenylmethane, bis- (4-hydroxyphenyl) tolylmethane, 4, 4'-dihydroxydiphenyl, bis- (4-hydroxyphenyl) sulphone and especially 2, 2-bis- (4-hydroxyphenyl) -propane (bisphenol A) .

Particularly suitable epoxy compounds are epoxy resins, for example, of the average formula:

in which Z is a small number and is an integer or fraction, for example between 0 and 25.

The diglycidyl ethers of bisphenol A

The diglycidyl ethers of bisphenol A to be used in accordance with the present invention are diglycidyl ethers having the formula:

wherein n'represents 0 or a positive number having a value of 0 to about 25.

Diglycidyl ether of biphenyl-A (DGEBA) prepolymers are prepared by reaction of epichlorohydrin with 2, 2-bis (p-hydroxyphenyl) propane (bisphenol-A) in the presence of an alkali metal hydroxide, characterized by:

(a) gradually feeding an aqueous solution of alkali metal hydroxide into a mixture of epichlorohydrin and bisphenol-A in a molar ratio of at least 10: 1, until the ratio between the moles of alkali metal hydroxide fed in and the number of phenolic hydroxyl groups in said mixture is from 1: 1 to 1.05: 1, while maintaining the reaction medium at boiling point, distilling off water in the form of an azeotropic mixture with epichlorohydrin and recycling the distilled epichlorohydrin into the reaction medium, the addition of alkali metal hydroxide and the distillation conditions being so adjusted as to maintain in the reaction medium a content of liquid water of from 0.1 wt. ％to 0.7 wt. ％and a pH value between 7 and 9； and

(b) recovering the epoxy resin from the reaction products.

Preferably, the epichlorohydrin/bisphenol-A molar ratio should not exceed 15: 1. Values of the said ratio which are less than 10: 1 do not give epoxy resins with the desired characteristics, especially as regards the values of the viscosity and the hydrolyzable chlorine content. On the other hand no appreciable improvements are obtained by using epichlorohydrin/bisphenol-Amolar ratios greater than 15: 1.

The best results are obtained by maintaining said ratio at a value of from 12: 1 to 13: 1.

The aqueous solution of alkali metal hydroxide is fed in until the ratio between the moles of alkali metal hydroxide and the number of phenolic hydroxyl groups is from 1: 1 to 1.05: 1, so as not to enhance those secondary reactions which give rise to the formation of undesirable by-products. It should be noted that it was usual in the art to employ a large excess of alkali metal hydroxide with respect to the stoichiometric value (typically an excess of 10-20％) , with the object of reducing the hydrolyzable chlorine content in the epoxy resin, with consequent diminutions in yield and formation of undesirable by-products.

Preferably, a concentrated aqueous solution of alkali metal hydroxide is used, for example a solution containing from 40 wt. ％to 50 wt. ％of the said hydroxide. The hydroxide is preferably sodium or potassium hydroxide.

The fundamental feature of the process of this invention consists in keeping an amount of water of from 0.1％to 0.7％by weight and a pH value between 7 and 9 in the reaction medium, during the addition of alkali metal hydroxide.

It has in fact been found that the use of water contents beyond the indicated range leads to the production of epoxy resins with excessively high values of molecular weight and viscosity. These resins typically have a viscosity at 25 ℃. greater than 8, 000 cps.

On the other hand, use of a pH value greater than 9 brings about undesirable effects similar to those encountered in those known methods in which excess alkali metal hydroxide is used.

The best results are obtained by maintaining in the reaction medium a water content of 0.4％to 0.6％by weight and a pH value between 7 and 8. The water is continuously removed from the reaction medium in the form of an azeotropic mixture with epichlorohydrin； the vapors thus produced are condensed with separation into two layers, the aqueous layer being discharged and the epichlorohydrin layer being recycled into the reaction medium.

The feed rate of the aqueous solution and the rate of evaporation of the water (reaction water and that introduced with the alkali metal hydroxide) are adjusted so as to maintain the water content and pH of the reaction mass within the ranges of values defined above. The addition of the aqueous alkali metal hydroxide is generally effected in a period of from 3 to 6 hours.

In practice it has been found that these conditions are more easily achieved when the reaction mass is boiled at a pressure of from 150 mm Hg to 350 mm Hg, and at a temperature of from 70℃ to 90℃. It has also been found that the best results, as regards all the characteristics of the liquid epoxy resin, are obtained by avoiding, as far as possible, contact of the reaction mass with the alkali metal chloride obtained as a by-product of the reaction.

To this end the reaction mass may be circulated continuously through a self-cleaning filter or a centrifuge, placed outside the reaction zone. This operation is facilitated by the fact that, in view of the working conditions, the alkali metal chloride precipitates in crystalline form and can therefore be removed without too much difficulty.

Upon completion of the alkali metal hydroxide addition, it is generally convenient to keep the mass boiling for a period of time of from 10 to 20 minutes, thus removing the residual water.

Finally the liquid epoxy resin is recovered from the reaction products by conventional methods. Thus, for example, water can be added to the reaction products to wash out the alkali metal chloride. The aqueous phase is then separated from the organic phase consisting of a solution of the liquid epoxy resin in epichlorohydrin. Obviously this operation may not be necessary when the alkali metal chloride is removed in the course of the reaction.

The unreacted epichlorohydrin is then distilled off, and it is generally convenient to filter off the distillation residue so as to remove any inorganic compound present.

The reaction yields based on the converted epichlorohydrin are in each case 95％or more, whereas in known methods in which an excess of sodium hydroxide of 10％-20％over the stoichiometric value is used, these yields are of the order of 85％-90％.

Derivative of diglycidyl ethers of bisphenol A

Functionalization of the hydroxyl groups of the bisphenol-Aepichlorohydrin derived polymer significantly alters its properties and produces a markedly different material A variety of reactants may be used to modify the bisphenol-A epichlorohydrin derived polymer and form a linear polymer of the following structure having ester, amide, ether, or silyl ether groups in place of the free hydroxyl groups:

where J is --C (O) R¹, --C (O) NHR², --C (O) NR² R³, --CHR⁴ OR⁵, or --SiR¹ R² R³, and R¹, R², R³, R⁴, and R⁵ are substituted or unsubstituted alkyl, aryl or cycloalkyl groups such as: --CH₃ --CH₂ Cl, --CH₂ OCH₃, --CH₂ CH₃, --CH (CH₃₎ ₂, --C₄ H₉ --n, --C₅ H₁₁ --n, --C₈ H₁₇ --n, --CH (C₂ H₅₎ ₂, --C₆ H₁₁ --c, --CH₂ CH₂ C₆ H₅, --CH₂ CH (C₆ H₅₎ ₂, --CH₂ OCH₂ C₆ H₅, --CH₂ CH₂ C₆ H₃ (3, 4--OCH₃₎ , --CH₂ CO₂ C₂ H₅, --C₆ H₅, --C₆ H₄ (p--C₅ H₁₁₎ , --C₆ H 4 (p--OC₅ H₁₁₎ , and --C₆ H₄ (p--C₁₀ H₂₁₎ . R⁴ and R⁵ may also optionally join together to form a heterocycle. When J is --SiR¹ R² R³, R¹, R², and R³ are preferably chosen from methyl and phenyl groups.

For the purposes of this invention, a polymer derived from bisphenol-A and epichlorohydrin is considered to be "substantially free of free hydroxyl groups" when at least 50％of the polymer units derived from epichlorohydrin do not contain free hydroxyl groups. Preferably, at least 75％of such units, and more preferably at least 95％of such units, will have their free hydroxyl groups blocked.

Examples of particular polymers of the invention according to the above formula include E-1 through E-19, which are obtained by blocking the free hydroxyl groups of

PKHH Phenoxy Resin:

The polymers of the invention give improved stability as compared to the non-functionalized polymer containing free hydroxyl groups, and compared to bisphenol-A polycarbonate.

Polyisocyantes which can be employed according to the invention are of both aromatic and aliphatic types. Suitable polyfunctional isocyanates have two or more isocyanate groups. Examples of compounds providing reactive isocyanate groups include para-phenylene diisocyanate, meta-phenylene diisocyanate, naphthalene-1, 5-diisocyanate, tetrachloro-m-phenylene diisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4, 4-diphenyl diisocyanate, the dichloro diphenyl methane diisocyanates, bibenzyl diisocyanate, bitolylene diisocyanate, the diphenyl ether diisocyanates, the dimethyldiphenyl diisocyanates, the polymethylene polyphenyl isocyanates, triphenylmethane-4, 4', 4"-triisocyanate, isopropylbenzene α-diisocyanate and the like.

Suitable amines for use have two or amine groups. Examples of suitable amines for use in the present invention are diamine and higher polyamine reactants, including ethylene diamine, phenylene diamine, toluene diamine, hexamethylene diamine, diethylene triamine, triethylenetetramine, piperazine, 1, 3, 5-benzenetriamine trihydrochloride, 2, 4, 6-triaminotoluene trihydrochloride, tetraethylene pentamine, pentaethylene hexamine, polyethylene imine, 1, 3, 6-triaminonaphthlene, 3, 4, 5-triamino-1, 2, 4-triazole, melamine, and 1, 4, 5, 8-tetraminoanthraquinone.

The microcapsules may have any suitable particle size. The average particle size of the microcapsules generally ranges from about 1 to about 130 microns, preferably from 1 to 100 microns, more preferably from 1 to 50 microns, with a preferred average particle size of about 1 to 50 microns. Such relatively fine particles are advantageous to prevent plugging of orifices in the spraying equipment used for field application of the pesticide compositions.

The multi-phase reaction mixture may contain other components, as required, for example to provide microcapsules of the required size and/or to facilitate other aspects of the process. For example, the aqueous phase may comprise one or more surfactants. Suitable surface active agents are known in the art and include the sodium salt of alkylnaphthalene sulfonic acid, the potassium salt of alkylnaphthalene sulfonic acid, salts of polystyrenesulfonic acid, in particular, the alkali metal, alkaline earth metal and ammonium salts thereof, and salts of condensates of naphthalenesulfonic acids, and mixtures thereof. The dispersant system for the microencapsulation process may also optionally contain one or more non-ionic surfactant, non-ionic protective colloid, or a cationic component. Lignosulfonates are a particularly preferred surfactant for use in the process, in particular sodium lignosulfonate.

The compositions of the present invention may include one or more emulsifiers, the emulsifiers can be cationic, anionic or nonionic, but are more preferably anionic or nonionic. Examples of particularly suitable anionic surfactants for this purpose are sulfonates such as calcium dodecyl benzenesulfonate. Examples of particularly suitable nonionic surfactants are polyoxyethylated (POE) sorbitan esters such as POE (20) sorbitan trioleate and polyoxyethylated (POE) sorbitol esters such as POE (40) sorbitol hexaoleate. Suitable emulsifiers are known in the art and are commercially available. For example, polyvinyl alcohol (

203) , POE (20) sorbitan trioleate is commercially available under the tradename TWEEN 85 marketed by Uniqema. POE (40) sorbitol hexaoleate is commercially available under the tradenames ATLAS G1086 and CIRRASOL G1086 marketed by Uniqema.

The combination of a POE sorbitan ester with a POE sorbitol ester allows the HLB (hydrophilic-lipophilic balance) value of the surfactant to be optimized, so as to obtain the highest quality emulsion (smallest suspended droplets) when the composition is added to water. High quality emulsions typically lead to optimal herbicidal performance. Therefore of particular note for preferred herbicidal performance is a composition of the present invention comprising one or more nonionic surfactants selected from polyoxyethylated (POE) sorbitan esters such as POE (20) sorbitan trioleate and polyoxyethylated (POE) sorbitol esters such as POE (40) sorbitol hexaoleate and mixtures thereof.

The mixture may also comprise an antifoam agent. Again, suitable antifoam agentsare known in the art. One preferred antifoam agent is a polydimethyl siloxane antifoam agent (Dow

1500) .

The mixture may also comprise one or more anti-freezing agent. Again, suitable anti-freezing agents are known in the art. One preferred agent is propylene glycol.

Other components, that may be included in the multi-phase reaction mixture, include one or more stabilizers. Suitable stabilizers are known in the art and include calcium chloride and sodium nitrate.

It may also be preferred to include in the reaction mixture a neutralizing agent, in particular to control the pH and prevent the formation of acidic conditions which may arise as a result of the condensation reactions. Suitable neutralizing agents are known in the art and include hydrochloric acid.

The microcapsules once prepared may be formulated in any suitable manner. Suitable formulations and formulating techniques for such microcapsules are known in the art. A suspension or slurry of the microcapsules in a suitable diluent, most preferably water, is one preferred embodiment for shipping, storing, and ultimately dispensing the composition to the area to be treated. Conventional spraying apparatus is used for application of these formulations.

The formulation may be applied directly to the target area. Alternatively, the composition may be further diluted, prior art application. For example, a convenient water dispersion, suspension or slurry for shipping and storage will consist of from about 10％to 30％by weight of microcapsules, more preferably about 25％, of the pesticide-containing microcapsules, which will be diluted with water to about 1％by weight for spraying.

It has been found that the formulations of the present invention exhibit a high level of stability when being shipped and stored.

The compositions of the present invention may be used to control unwanted plant growth at a locus.

Accordingly, in a further aspect, the present invention provides a method of controlling plant growth at a locus, the method comprising applying to the locus a composition as described hereinbefore.

The present invention further provides the use of the compositions described hereinbefore in the control of plant growth.

The compositions may be applied to the area where control of plant growth is desired, prior to or after emergence of the target plants, for example by spraying onto the surface of the soil or onto the foliage of the plants. The user may, if desired, blend the formulation into the upper layer of soil by cultivation.

As noted above, the compositions of the present invention are particularly suitable for the formulation of water immiscible material and high volatile material, such as clomazone, abamectin, pendimethalin, lambda cyhalothrin, spinosad, emamectin benzoate, deltamethrin, cypermethrin, acetochlor, alachlor, metolachlor and their mixture. The active ingredient to be encapsulated can be dissolved in aromatic solvent. One preferred aromatic solvent is SOLVESSO (EXXON MOBIL) .

In order that the concept of the present invention may be more completely understood, the following examples are set forth in which all parts are parts by weight unless otherwise indicated. These examples are set forth primarily for the purpose of illustration and any specific enumeration of detail contained therein should not be interpreted as a limitation in the present case.

EXAMPLES

EXAMPLE 1-13

General Procedure (Synthesis of DEGBA)

An apparatus comprising a reaction vessel (flask) , mechanical agitator, electric heater, distillation column, a condenser, a separator for the epichlorohydrin-water distillate fitted with a siphon for recycling the epichlorohydrin, and a system for regulating the pressure in the reaction vessel was used. 3.000 parts by weight of epichlorohydrin and 585 parts by weight of bisphenol-A (12.6: 1 molar ratio) were fed into the flask. The pressure in the apparatus was regulated to the desired value and the mass was gradually heated to boiling point. Then 420 parts by weight of a 49％by weight aqueous solution of sodium hydroxide were introduced gradually over a period of about 5 hours. Upon completion of this addition, the ratio of the number of moles of sodium hydroxide added to the number of phenolic hydroxyl groups is 1.00: 1.

During the addition of sodium hydroxide, the water was removed from the boiling mass in the form of an azeotropic mixture with epichlorohydrin. The resultant vapors were condensed, the denser epichlorohydrin layer was recycled and the aqueous layer was discharged.

In each case, the conditions were so regulated as to maintain the water content of the reacting mass at the desired value.

After the addition of the sodium hydroxide the mass was kept boiling for a further 15 minutes. Then about 500 parts by weight of water were added, the mass was agitated for 20 minutes and the aqueous phase removed by decantation, operating at about 50 ℃.

The organic phase was distilled, working first at atmospheric pressure and then at sub-atmospheric pressure (about 10 mm Hg) in order to remove the unreacted epichlorohydrin completely.

The distillation residue was finally filtered to remove any residual inorganic salts, using diatomaceous earth as a filter aid.

The liquid epoxy resin thus obtained was tested to determine its properties, and the results were recorded in the Table.

More particularly in the Table were recorded:

· under (A) the operating pressure in mm Hg；

· under (B) the temperature of the reacting mass；

· under (C) the average pH of the reacting mass；

· under (D) the average percentage by weight of water present in liquid form in the reacting mass, the determination being carried out by the Karl Fischer method；

· under (E) the rate of distillation expressed in ml of distillate per hour.

The values given in the Table under (A) , (B) , (C) , (D) and (E) were taken during the addition of the aqueous sodium hydroxide.

In the Table were recorded:

· under (F) the viscosity of the epoxy resin at 25 ℃ expressed in cps；

· under (G) the epoxy equivalent of the resin, as previously defined；

· under (H) the corresponding value of "n" with reference to formula (I) ；

· under (I) the hydrolyzable chlorine content expressed as a percentage by weight of the resin；

Example I is for comparison in that the water content in the reacting mass is less than the minimum value.

Examples 9 to 13 are also for comparison in that the said water content is greater than the maximum limit. Examples 2 to 8 were carried out according to the process of the invention.

Table 1.

EXAMPLE 14 (COMPARISON)

Example 1 was repeated, using a 5％excess molar amount of sodium hydroxide with respect to the number of phenolic hydroxyl groups in the bisphenol-A feed.

A liquid epoxy resin was obtained with a hydrolysable chlorine content of 0.3％by weight, whilst the other characteristics of the resin remain practically unchanged.

EXAMPLES 15-21

Examples 2 to 8 were repeated using a 5％excess molar amount of sodium hydroxide with respect to the number of phenolic hydroxyl groups in the bisphenol-A feed.

Liquid epoxy resins were obtained with a hydrolysable chlorine content of from 0.02％to 0.09％by weight, whilst the other characteristics remain practically unchanged.

EXAMPLES 22-26 (COMPARISON)

Examples 9 to 13 were repeated using a 5％excess molar amount of sodium hydroxide with respect to the number of phenolic hydroxyl groups in the bisphenol-A feed.

Liquid epoxy resins are obtained with a hydrolysable chlorine content of 0.1％-0.4％by weight whilst the other characteristics remain practically unchanged.

In Examples 14 and 22-26 the Hazen color of the liquid epoxy resin is of the order of 200； in Examples 15-21 the Hazen color is of the order of 80-120.

EXAMPLE 27

The apparatus described in the previous Examples was used, the flask being filled with 3,000 parts by weight of epichlorohydrin and 585 parts by weight of bisphenol-A (12.6: 1 molar ratio) .

The pressure in the apparatus is regulated to 160 mm Hg and the mixture was heated to boiling point.

439 parts by weight of a 49％by weight aqueous solution of sodium hydroxide were gradually introduced over 5 hours, the ratio between the moles of sodium hydroxide fed in and the number of hydroxyl groups being then of 1.048: 1. During this addition the water was removed in the form of an azeotrope with epichlorohydrin and the distilled epichlorohydrin is recycled.

Moreover, the sodium chloride was formed as a by-product of the reaction, was removed by circulating the reaction mass continuously through a centrifuge placed outside the reactor.

After the addition of the sodium hydroxide solution, the unreacted epichlorohydrin was distilled off and the distillation residue was filtered in the manner already described.

Thus a liquid epoxy resin is obtained having the following characteristics:

· epoxy equivalent: 172

· viscosity at 25℃. (cps) : 7, 000

· hydrolysable chlorine (％by weight) : 0.003

· "pot-life" at 25℃. (minutes) : 100

· Hazen color: 60

· volatile substances (％by weight) : 0.

The reaction yield is equal to 95.3％of the theoretical. The epoxy resin is represented by Formula (I) with "n" equal to 0.014.

EXAMPLE 28

Example 27 was repeated, 420 parts by weight of an aqueous 49％by weight solution of sodium hydroxide being fed in.

The obtained epoxy resin had a hydrolyzable chlorine content of 0.06％by weight whilst the other characteristics are practically unchanged.

EXAMPLE 29

General Procedure (Synthesis of Amine terminated DEGBA)

20g epoxide from Example 6 and diethylenetriamine was mixed well and poured into a mole and cured at 60℃ for 2 hours to give a flexible and tough material.

It is noted that:

(1) In order to avoid gel product, the proper ratio of amine to epoxy resin is required. The first step requires at least a 1: 4 molar ratio of amine to epoxide.

(2) The second step, reaction of polyfunctional epoxy resin with diethylenetriamine, a large excess of diethylenetriamine was needed.

(3) Acetone or a low boiling ketone is essential for preparing these products.

EXAMPLE 30

General Procedure (Synthesis of Isocyanate terminated DEGBA)

80 g epoxide from Example 6 was mixed well with 20 parts by weight (g) of polymethylene polyphenylisocyanate (PMPPI) , to which 0.25 part by weight (g) of BF₃ had been added beforehand in the form of a 25％tetrahydrofurfuryl alcohol complex. A liquid resin forms which had a pot-life of more than 1 hour at room temperature and which can be poured easily. After curing for 15 hours at about 150℃., a casting results which has a flexural strength of 92 N mm^-2, an impact strength of 0.76 N mm^-2, a modulus of elasticity of 3, 000 N mm^-2 and a T_G max (modulus of shear) of 90 ℃.

EXAMPLE 31, Preparation of microencapsulated from Example 29

A. A water-immiscible organic phase, prepared just prior to use having the following composition:

· 200 g technical Clomazone

· 13.9 g amine terminated DEGBA prepolymers

· 15.1g polymethylene polyphenylisocyanate (PMPPI, Suprasec-5005 )

B. An aqueous solution having the following composition:

· 4g Emulsogen EL360

· 16 g POE (20) sorbitan trioleate

· 16g Lignosulfonic acid, sodium salt (Reax 88B)

· 16g Sulfonated aromatic polymer, sodium salt (MORWET D-425 POWDER)

· 3 g Antifoam (Dow

1500)

· 141.3 g Water

Step 1

13.9g amine terminated DEGBA prepolymers was dispersed in 14.7g SOLVESSO (EXXON MOBIL) . The mixture was mixed well at high speed in a high-shear mixer. 200g Clomazone, 15.1g polymethylene polyphenylisocyanate (PMPPI, Suprasec-5005) were finally added.

Step 2

16 g POE (20) sorbitan trioleate, 16g Lignosulfonic acid, sodium salt (Reax 88B) , 16 g sulfonated aromatic polymer, sodium salt (MORWET D-425 POWDER) and 3 g antifoam (Dow

1500) was added in 141.3g water to be aqueous phase

Step 3

Water-immiscible organic phase was added dropwise into aqueous phase. After mixing by high-shear mixer, oil in water dispersion was formed.

Step 4

The oil in water dispersion was transferred into an Erlenmeyer flask. The dispersion was heated and maintained at about 50 ℃ for 4 hours. Adjuvant, such as stabilizers (1.69 g calcium chloride, 0.70 g sodium nitrate) , thickening agent (2％xanthan gum, 0.67g) , antifreeze agent (1.60 g propylene glycol) was added when the temperature was cooled down to about 30 ℃. pH adjustor (hydrochloric acid 36％-38％) was added to keep pH at 6-9.

EXAMPLE 32, Preparation of microencapsulated from Example 30

· 200 g technical Clomazone

· 15 g isocyanate terminated DEGBA prepolymers

B. An aqueous solution having the following composition:

· 3.8g Emulsogen EL360

· 16 g POE (20) sorbitan trioleate

· 16g Lignosulfonic acid, sodium salt (Reax 88B)

· 16g Sulfonated aromatic polymer, sodium salt (MORWET D-425 POWDER)

· 3 g Antifoam (Dow

1500)

· 168 g Water

Step 1

15g isocyanate terminated DEGBA prepolymers was dispersed in 14.7g SOLVESSO (EXXON MOBIL) . The mixture was mixed well at high speed in a high-shear mixer. 200g Clomazone was finally added.

Step 2

16g POE (20) sorbitan trioleate, 16g Lignosulfonic acid, sodium salt (Reax 88B) , 16g sulfonated aromatic polymer, sodium salt (MORWET D-425 POWDER) and 3g antifoam (Dow

1500) was added in 141.3g water to be aqueous phase.

Step 3

Step 4

The oil in water dispersion was transferred into an Erlenmeyer flask. 20g 1, 6-hexamethylene diamine aqueous solution (20g diethylenetriamine in 17.3g water) was added dropwise with stirring. The dispersion was heated and maintained at about 50℃ for 4 hours. Adjuvant, such as stabilizers (1.69g calcium chloride, 0.70g sodium nitrate) , thickening agent (2％xanthan gum, 0.67g) , antifreeze agent (1.60g propylene glycol) was added when the temperature was cooled down to about 30 ℃. pH adjustor (hydrochloric acid 36％-38％) was added to keep pH at 6-9.

EXAMPLE 33-38

Example 31 and 32 were repeated for the mixture of Clomazone and any one of acetochlor, alachlor and metolachlor.

EXAMPLE 39-53

Examples 31 and 32 were repeated for the following active ingredients:

Abamectin, pendimethalin, lambda cyhalothrin, spinosad, emamectin benzoate, deltamethrin and cypermethrin.

Claims

A microcapsules polymer skin material comprising crosslinked polyepoxide–polyurea co-polymer.
The microcapsules polymer skin material according to claim 1, wherein the polyepoxide has an average formula:

in which Z is a small number and is an integer or fraction, for example between 0 and 25.
The microcapsules polymer skin material according to claim 1, wherein the polyepoxide is selected from the group consisting of diglycidyl ether of biphenyl-A (DGEBA) and its derivative.
The microcapsules polymer skin material according to any preceding claim, wherein the crosslinked polyepoxide – polyurea co-polymer is prepared by forming amine terminated or isocyanate terminated diglycidyl ether of biphenyl-A (DGEBA) prepolymers； then reacting amine terminated DGEBA with polyfunctional isocyanate to form polyepoxide - polyurea copolymer； or reacting isocyanate terminated DGEBA with polyfunctional amine to form polyepoxide – polyurea.
The microcapsules polymer skin material according to claim 4, wherein the amine terminated diglycidyl ethers of Bisphenol A is prepared by reaction of polyfunctional amines with the epoxy terminated derivatives of glycidyl ethers of Bisphenol A.
The microcapsules polymer skin material according to claim 4, wherein the isocyanate terminated diglycidyl ether of biphenyl-A is prepared by reaction of polyfunctional isocyanate with the epoxy terminated derivatives of glycidyl ethers of Bisphenol A.
The microcapsules polymer skin material according to claim 4, wherein the polyfunctional isocyanate is selected from the group consisting of para-phenylene diisocyanate, meta-phenylene diisocyanate, naphthalene-1, 5-diisocyanate, tetrachloro-m-phenylene diisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4, 4-diphenyl diisocyanate, the dichloro diphenyl methane diisocyanates, bibenzyl diisocyanate, bitolylene diisocyanate, the diphenyl ether diisocyanates, the dimethyldiphenyl diisocyanates, the polymethylene polyphenyl isocyanates, triphenylmethane-4, 4', 4"-triisocyanate, isopropylbenzene α-diisocyanate and the like.
The microcapsules polymer skin material according to claim 4, wherein the polyfunctional amine is selected from the group consisting of ethylene diamine, phenylene diamine, toluene diamine, hexamethylene diamine, diethylene triamine, triethylenetetramine, piperazine, 1, 3, 5-benzenetriamine trihydrochloride, 2, 4, 6-triaminotoluene trihydrochloride, tetraethylene pentamine, pentaethylene hexamine, polyethylene imine, 1, 3, 6-triaminonaphthlene, 3, 4, 5-triamino-1, 2, 4-triazole, melamine, and 1, 4, 5, 8-tetraminoanthraquinone
The microcapsules polymer skin material according to any of claims 4-8, wherein the reaction is occurred in the presence of a solvent selected from acetone or methyl ether ketone, preferably acetone.
A composition comprising a water-immiscible material or high volatile material encapsulated within a microcapsule having a wall comprising the microcapsules polymer skin material according to any of claims 1-9.
The composition according to claim 10, wherein the water-immiscible material or high volatile material is selected from clomazone, abamectin, pendimethalin, lambda, spinosad, emamectin, benzoate, deltamethrin, cypermethrin, acetochlor, alachlor, metolachlor and combination thereof.
The composition according to claim 10, the water-immiscible material or high volatile material is clomazone.
The composition according to any of claims 10-12, wherein the microcapsules have an average size of from 1 to 50 microns.
The composition according to any of claims 10-13, wherein the composition comprises one or more surfactants, and/or one or more emulsifiers, and/or an antifoam agent, and/or one or more anti-freezing agent, and/or one or more stabilizers, and/or a neutralizing agent.
A method of controlling plant growth at a locus, comprising applying to the locus a composition according to any of claims 10-14.
A use of the composition according to any of claims 10-14 in the control of unwanted plant growth.