WO2019222955A1

WO2019222955A1 - Use of polyester thickeners and thixotropic compositions

Info

Publication number: WO2019222955A1
Application number: PCT/CN2018/088159
Authority: WO
Inventors: Jing Dai; Jianmin Xu; Zhitao XING; Xiaoling Wang; Lengfeng ZHENG; Liang Bao
Original assignee: Evonik Specialty Chemicals (Shanghai) Co., Ltd.
Priority date: 2018-05-24
Filing date: 2018-05-24
Publication date: 2019-11-28
Also published as: CN110527434A

Abstract

Use of a polyester represented by the general formula (I) to produce a thixotropic composition or a thixotropic product, or as a thixotropic thickener. A household care aqueous composition comprising the polyester or a thixotropic product comprising the household care aqueous composition is also provided. The thixotropic aqueous composition or product may be in the form of a gel and can be sprayable although not flowable. The polyester is biodegradable and environmentally friendly and can be widely used in applications including household care.

Description

Use of polyester thickeners and thixotropic compositions

Technical Field

The present invention relates to use of a polyester to produce a thixotropic composition such as a thixotropic gel, or as a thixotropic thickener, and thixotropic compositions prepared with the polyester.

Background art

Sprayable gel products have been developed for various applications such as household cleaning.

For example, US 6,838,426 B1 discloses a cleaning composition comprising ethyl butyrate, wherein an acrylic polymer is used as the gelling agent.

US 5,705,470 discloses a sprayable cleaning gel composition having the property of having a very high viscosity (over about 900 cP) and yet is easily sprayable, having an excellent spray distribution on a surface upon which it is sprayed, and further providing an anti-static quality to the surface. The composition comprises a water-soluble polymeric thickening agent such as polyacrylic acid powders.

These gelling agents are mostly acrylic polymers and are not biodegradable.

US 3,915,921 discloses that copolymers of a carboxylic acid monomer and one or more higher, that is 10-30 carbon atom, alkyl acrylate esters may serve as efficient thickeners of aqueous solutions, even in the presence of substantial amounts of inorganic salts. However, when such thickeners are formulated into a mono-component aqueous solution, the aqueous solution does not have a thixotropic effect.

C36 dimer fatty acid (DFA) is one of the biggest molecular weight acids. It has two active carboxyl and long-chain alkyl radical. Dimer fatty acid has been traditionally used to synthesize and formulate hot-melt adhesives, flexographic inks, functional coatings, and other engineering materials. The polyester synthesized using dimer fatty acid and polyethylene glycol shows some surface activities for the polyethylene glycol having some hydrophilic groups (-O-) , and this polyester could be used as a polymeric surfactant. It has been wildly applied such as emulsification, lime soap dispersion, solubility enhancement, and so on.

US 6,800,275 discloses a series of polyester which provide conditioning effects to the skin, re-hydrating it while at the same time minimizing trans epidermal water loss.

Feng, et. al., reported a dimer fatty acid polyethylene glycol polyester synthesized by using dimer fatty acid and polyethylene glycol (400) as materials (Guangzhu Feng, et. al, Journal of Polymer Research (2007) 14: 115-119) . It can be used as a non-ionic polymeric surfactant, but not as a thixotropic thickener.

It is desirable to find a new polyester that may be used as a gelling agent which has novel properties such as thixotropic, and thus may attribute new appealing functions in various products.

Summary of the invention

The present invention provides use of a polyester to produce a thixotropic composition.

As used herein, “thixotropic composition” refers to a composition that has a thixotropic property. Examples of the thixotropic composition include household care compositions such as a cleanser or polish, etc. The thixotropic composition can be essentially not flowable (like a gel) but can be sprayable. The thixotropic composition may typically be a sprayable gel. The polyester used in the present invention is also biodegradable. The polyester may be used as a thickener.

The present invention further provides use of a polyester to produce a thixotropic product. As used herein, “thixotropic product” refers to a product comprising a thixotropic composition.

The present invention also provides use of a polyester used in the present invention as a thickener, especially as a thixotropic thickener, for example a gelling agent in applications including household care. It has been surprisingly found that the novel polyester described below is very useful as a highly effective and thixotropic thickener, especially in household care applications. As used herein, “thixotropic thickener” refers to a thickener which enables a composition comprising it to possess a thixotropic effect, in addition to its thickening effect.

In one aspect, the polyester used in the present invention is a polyester thickener which is a water-soluble polymer and which has the general formula (I) :

wherein R ¹ represents H or CH ₃, and wherein R ¹ may be the same or different in structure repeat units of -CH ₂CH (R ¹) -O-, e.g., R ¹ may be all H, or comprise both H and CH ₃ and R ¹ comprises more than 50, 60, 70, 80, 90, 95, 98, or 99 molar %of H referring to all R ¹ in the polyester molecule;

R ² and R ³ may be the same or different, and each independently represents an hydrocarbylene group selected from the group consisting of saturated or non-saturated, branched, long-chain hydrocarbylene groups with a carbon atom number from 10 to 50, preferably from 18-40, more preferably from 30-40; wherein R ² may be the same or different in separate structure repeat units of -C (O) -R ²-C (O) -;

R ⁴ represents Rx, or -CH ₂CH (R ¹) -OH;

Rx each independently represents H or Ry, Ry each independently represents an end-capping group;

n is a number ranging from 80-1200, for example 100-1200, preferably 120-1200, more preferably from 120-800; even more preferably from 200-500; and

x is a number ranging from 1-10, preferably from 2-6, for example 1-5, 1-4, and 1-3.

Ry is such an end-capping group that the polyester containing Ry is water-soluble. Preferably, the polyester containing Ry is water-soluble and is not an ionic compound.

The term “water-soluble polymer” in this invention means a polymer that can be swellable and soluble in water and form a solution.

The term “water-soluble” or “soluble in water” in this invention means that the polyester of the invention has a solubility of >0.1 g/100ml water at 25 ℃ and 1 bar.

The polyester with Ry ( “protected form” ) is generally obtained by an end-capping reaction, for example an esterification reaction of the carboxylic acid end group (s) of the polyester wherein Rx = H ( “unprotected form” ) with an end-capping agent that is reactive with carboxyl groups, for example an alcohol compound represented by HORy.

As used herein, an alcohol compound refers to any organic compound in which the hydroxyl functional group (–OH) is bound to a saturated carbon atom.

The end-capping reaction with an end-capping agent is employed to decrease the amount of free hydrogen ions available from the polyester in the water solution of the polyester and preferably provide more inter-molecular entanglement of the polyester molecules. Reacting with an end-capping agent may increase the viscosity or thickening effect of the polyester compared with the polyester wherein Rx = H or broaden the application scope of the polyester thickener for example the polyester may be usable in basic systems. A person skilled in the art can choose a suitable end-capping agent based on the description here.

As shown in formula (I) , the polyester of formula (I) wherein Rx = H has a first end group being a carboxylic group (first end carboxylic group) and a second end group being a hydroxyl group or a carboxylic group (second end carboxylic group) . The first end carboxylic group, or the second end carboxylic group, or both end carboxylic groups may be protected by for example esterification reaction with an alcohol compound.

After esterification reaction at the carboxylic acid end group (s) with the alcohol compound, the carboxylic acid end group (s) of compound of formula (I) may be protected and less free hydrogen ions will be released when the polyester is dissolved in water. Thus, the obtained polyester with Ry after esterification reaction (i.e., the ester of an alcohol compound and formula (I) compound with Rx = H) may be more stable and have a better thickening performance than the un-esterified formula (I) compound with Rx = H.

The end-capping agent may be selected from alcohol compounds such as a monohydric alcohol, a polyhydroxy compound, and a polyether compound.

The monohydric alcohol may be a saturated or unsaturated, branched or unbranched monohydric alcohol, preferably with 1-24 carbon atoms, more preferably with 1-18, or 1-8 carbon atoms. Preferably, the monohydric alcohol is branched. Branched alcohols may provide more molecular entanglement. Examples of monohydric alcohols include methanol, ethanol and lauryl alcohol.

The polyether compound may be selected from polyoxyethylene ethers and polyoxypropylene polyoxyethylene ethers. Examples of polyether compounds include polyoxyethylene alkyl ethers, polyoxypropylene polyoxyethylene alkyl ethers and so on.

Specifically, the polyether compound may be selected from the following,

polyoxyethylene alkyl ethers,

polyoxyethylene alkyl ether is polyethylene glycol ether of alkyl alcohol. The polyoxyethylene alkyl ether can be the following general structure:

CH ₃- (CH ₂) a- (OCH ₂CH ₂) u-OH (P1)

wherein;

a has an average value from 9 to 21,

u has an average value from 2 to 200;

Polyoxyethylene alkenyl ether

The polyoxyethylene alkenyl ether can be the following general structure:

CH ₃- (CH ₂) bCH=CH (CH ₂) c- (OCH ₂CH ₂) v-OH (P2)

wherein;

b has an average value from 1 to 10,

c has an average value from 1 to 10,

v has an average value from 2 to 200; and

Polyoxypropylene polyoxyethylene alkyl or alkenyl or iso-alkyl or iso-alkenyl or dimethylpolysiloxane ether

The polyoxypropylene polyoxyethylene alkyl or alkenyl or iso-alkyl or iso-alkenyl or dimethylpolysiloxane ether can be the following general structure:

R ₈- (OCH (CH ₃) CH ₂) w- (OCH ₂CH ₂) z-OH (P3)

wherein;

R ₈ is alkyl alkenyl groups or isoalkyl alkenyl groups or dimethylpolysiloxane derivatives,

w has an average value from 2 to 100,

z has an average value from 2 to 100.

The alcohol compound (HORy) preferably is hydrophilic.

The alcohol compound (HORy) is preferably selected from the group consisting of a polyhydroxy compound, a branched long chain alcohol, which can be alkoxylated, or a mixture thereof.

The term polyhydroxy compound as used herein, refers to organic compounds containing two or more hydroxy groups (prior to condensation) linked to adjacent or non-adjacent carbon atoms. The polyhydroxy compound includes but not be limited to, dihydric alcohols, polyhydric alcohols, monosaccharides, disaccharides and oligosaccharides. Examples of the polyhydroxyl compounds include glycerol, 1, 4-butanediol, glucose, sorbitol etc.

A branched long chain alcohol contains at least 4, preferably at least 6 carbon atoms. The branched long chain alcohol may have 8, 10, 12 or more carbon atoms, for example 8-30, 8-28, 8-26, 8-24, 8-22, 8-20, 8-18, etc. The branched long chain alcohol also includes those hydrophilic branched long chain alcohols with ethylene oxide and/or propene oxide modifications, for example with 20 ethylene oxide repeats. Examples of the branched long chain alcohol include isomeric alcohol ethoxylates, such as isoceteth-20 (

Alkanol IC 20) and decyltetradeceth-20 ether.

In some examples, the polyester is a mixture with an average x of 2-5.

For the structure repeat units of -CH ₂CH (R ¹) -O-, R ¹ preferably may be all H, or comprise both H and CH ₃ in the polyester molecule. In some examples, R ¹ are all H; in some examples, R ¹ comprises both H and CH ₃, and R ¹ comprises more than 50, 60, 70, 80, 90, 95, 98, or 99 molar %of H referring to all R ¹.

In some embodiments, the polyesters used are dimer fatty acid polyesters, i.e., polyesters produced with dimer fatty acid, e.g. C36 dimer fatty acid as raw material. The dimer acid determines the structures R ² and R ³, of course.

The present invention further provides use of a polyester to produce a thixotropic composition or a thixotropic product, or as a thixotropic thickener, wherein the polyester is prepared according to a method comprising the step of esterification reaction of a bifunctional hydroxyl compound and a bifunctional carboxylic acid,

wherein the bifunctional hydroxyl compound may be represented by the general formula (II) ,

wherein R ⁵ represents H or CH ₃; wherein R ⁵ may be the same or different in structure repeat units of -CH ₂CH (R ⁵) -O-, e.g., R ⁵ may be all H, or comprise both H and CH ₃ and R ⁵ comprises more than 50, 60, 70, 80, 90, 95, 98, or 99 molar %of H referring to all R ⁵ in the polyester molecule; and

m is a number ranging from 100-1200, preferably 120-1200, more preferably from 120-800; even more preferably from 200-500;

wherein the bifunctional carboxylic acid may be represented by the general formula (III) :

wherein R ⁶ represents an hydrocarbylene group selected from the group consisting of saturated or non-saturated, straight or branched, hydrocarbylene groups with a carbon atom number from 10 to 50, preferably from 18-40, more preferably from 30-40.

The polyesters used in the present invention can be prepared with a method for preparation of a polyester, particularly the polyester according to formula (I) , comprising the step of esterification reaction of a bifunctional hydroxyl compound and a bifunctional carboxylic acid.

The method for preparation of a polyester typically includes the following steps:

(1) Mix a bifunctional hydroxyl compound and a bifunctional carboxylic acid to obtain a raw material mixture, the molar ratio of the bifunctional carboxylic acid and the bifunctional hydroxyl compound is more than 1, preferably more than 1.5, e.g. between 1.5 to 2.5;

(2) Add an esterification catalyst to the above raw material mixture; the amount of the catalyst based on the total weight of the raw material mixture is preferably from 0.1wt. -%to 5 wt. -%, for example 0.1-1wt. -%; and

(3) Keep the temperature of the reaction at 100-200℃, for example, 120-200℃, 140-200℃, preferably 140-180℃, preferably under removal of the formed water; and optionally

(4) Add an end-capping agent, for example an alcohol compound, stir and keep the reaction temperature at 100-200℃, for example, 120-200℃, 140-200℃, preferably 140-180℃, for 2-10 hours, preferably 3-8h.

Step (4) is a step to prepare the polyester with Ry ( “protected form” ) . If the target product is a polyester with Rx = H ( “unprotected form” ) , the method does not comprise step (4) ( “end-capping reaction step” ) .

In some embodiments, the method includes the following steps:

(1) Mix a bifunctional hydroxyl compound and a bifunctional carboxylic acid while heating to 60-100℃, preferably 70-90℃, to obtain a raw material mixture, the molar ratio of the bifunctional carboxylic acid and the bifunctional hydroxyl compound is more than 1, preferably between 1.5 to 2.5;

(2) Add an esterification catalyst after the above raw material mixture is melted; the amount of the catalyst based on the total weight of the raw material mixture is from 0.1wt. -%to 5 wt. -%, for example 0.1-1wt. -%; and

(3) Keep the temperature of reaction at 100-200℃, for example, 120-200℃, 140-200℃, preferably 140-180℃, and remove the formed water; the temperature is kept for 2-10 hours, preferably 3-8h.

The end groups of the polyester used in the present invention may be determined by molar ratio of the bifunctional hydroxyl compound and the bifunctional carboxylic acid.

The catalyst may be those conventional in the art. Examples of the catalyst can be selected from the group consisting of benzene sulfonic acid, sulfuric acid, stannous salts, tin salts and the like.

The bifunctional hydroxyl compound preferably is a polyoxyalkylene with a long chain, and may be represented by general formula (II) ,

m is a number ranging from 100-1200, preferably 120-1200, more preferably from 120-800; even more preferably from 200-500.

The bifunctional hydroxyl preferably has a molecular weight from 10000 to 20000.

If m in formula (II) is too small, for example, 8, e.g., when PEG-8 (also known as Polyethylene Glycol 400) is used as raw material, the polyester produced will not possess the desired thixotropic property and is not included in the present invention.

The bifunctional carboxylic acid may be represented by general formula (III) :

The bifunctional carboxylic acid is preferably a C36 dimer acid and/or a hydrogenated C36 dimer acid.

Examples of the structure of R ⁶ or R ² or R ³ include but not limited to the following,

An exemplary illustration of present invention’s reaction is as follows, wherein the bifunctional hydroxyl is PEG-240, and the bifunctional carboxylic acid is C36 dimer acid, i.e., (octadecadienoic acid) dipolymer.

According to the present invention, there is further provided an aqueous composition, particularly a household care aqueous composition comprising the polyester used in the present invention. The polyester used in the present invention can be represented by the general formula (I) or can be prepared by a method comprising the step of esterification reaction of the bifunctional hydroxyl compound and the bifunctional carboxylic acid as stated above. The aqueous composition can be easily prepared by dissolving the polyester of present invention into water, an aqueous solution or the like.

The term “aqueous composition” as used in the context of the instant invention refers to a composition containing water, preferably in an amount of from 50 wt. -%to 99wt. -%, preferably of from 55 wt. -%to 98 wt. -%, and the most preferred of from 60 wt. -%to 97 wt. -%, wherein the weight percent refer to the total weight of the composition.

The composition may comprise a suitable amount of the polyester used in the present invention that enables the composition to possess a desirable thixotropic performance and become, e.g. a sprayable gel. Such amount may be determined by a person skilled in the art by conventional means. The thixotropic composition has a shear thinning property and can be sprayable although not flowable. Examples of the aqueous composition include sprayable cleaning gel for household care applications.

The aqueous composition comprising the polyester used in the present invention preferably comprises the polyester in an amount of from 0.1 wt. -%to 50 wt. -%, preferably of from 0.3 wt. -%to 30 wt. -%, and the most preferred of from 0.5 wt. -%to 20 wt. -%, wherein the weight percent refer to the total weight of the composition.

For good thixotropic performance it has been found that the weight ratio of comprised polyester according to the invention to water is preferably bigger than 1 : 1000, preferably it is in the range of from 1 : 1000 to 1 : 10, even more preferably of from 1 : 200 to 1 : 20, and the most preferred of from 1 : 150 to 1 : 30.

The aqueous composition comprising the polyester used in the present invention preferably additionally contain at least one anti-oxidizing agent. Preferred anti-oxidizing agents contained in the aqueous composition of the present invention are selected from the group of butylated hydroxytoluene (BHT) , butylated hydroxyanisole (BHA) Tocopherol, Silymarin, lycopene, idebenone, nicotinamide, coenzyme Q10, resveratrol, propyl gallate, and vitamin C.

Surprisingly it was found that the presence of anti-oxidizing agents yield in more long term stable compositions.

According to the present invention, there is further provided a thixotropic product, for example a household care thixotropic product, comprising the aqueous composition, particularly the household care aqueous composition comprising the polyester used in the present invention, and a container, for example a bottle containing the composition. The polyester used in the present invention can be represented by the general formula (I) or can be prepared according to a method comprising the step of esterification reaction of the bifunctional hydroxyl compound and the bifunctional carboxylic acid as stated above. Examples of a household care thixotropic product include a malodor absorber, a polish (for furniture, leather or the like) , a disinfectant gel, a detergent and a multi-purpose cleaner (for cleaning glass, table top, floor, sofa, car seat, furniture, etc) . The aqueous composition of the thixotropic product can be sprayable although not flowable. The aqueous composition of the thixotropic product may be in the form of a gel, preferably a transparent or translucent gel.

In some embodiments, the composition or product may comprise 0.1-15wt. -%, for example 0.5-15wt. -%, 0.5-12wt. -%, 1-10wt. -%, 1-8wt. -%of the polyester used in the present invention.

The composition or product may easily prepared by comprising the step of dissolving the polyester used in the present invention and other ingredients in water.

The present invention provides a new application of these series of polyester. The polyester used in the present invention is a water soluble polymer which has ester bonds and may optionally have one or two carboxylic acid groups in the structure. It can be easily dissolved into water, and in water, it associates with water molecules to form a clear water gel. Therefore, the polyester used in the present invention shows a highly thickening effect in water, and can be used in application such as household care applications as a gelling agent.

Therefore, the present invention further provides a use of the polyester used in the present invention as a thickener, especially as a thixotropic thickener, particularly a gelling agent; for example in a household care composition, wherein the composition has a thixotropic property. The present invention also provides use of the polyester the present invention to produce a thixotropic product, particularly a household care thixotropic product.

Without wishing to be bound by theory, it was found that the special structure of the polyester of present invention of formula (I) is very important to the special properties. The polyester contains the two types of structural (repeat) units: one is the water-soluble polyoxyalkylene group with a long-chain, and the other one is the oil-soluble bifunctional carboxylic acid group. In addition, one end group should be a carboxylic group and the other end group should be a hydroxyl or carboxylic group (before reaction with an end-capping agent) . The bifunctional hydroxyl compound must be a polyoxyalkylene derivative, and the carbon chain must be long enough. This polyoxyalkylene repeat unit provides not only entanglement due to the long chain, but also give a water-soluble group. The bifunctional carboxylic repeat unit can provide hydrogen bonds based on its carboxylic acid residue in the molecule, and also plays the role of oil-solubility of the molecules. In addition to these functions, due to their bifunctional nature, these two repeat units provide crosslinks in the polyester molecule. The entanglement of the molecular and the hydrogen bond results in formation of a high-elastic gel by physical crosslinking and hydrogen bonding.

The polyester of present invention can be easily dissolved in the water, and the solution is preferably clear or transparent, so the balance between the oil-soluble and water-soluble groups, which the polyester of present invention possesses, is very important. If there are too many water-soluble groups, the polyester becomes merely a water-soluble polyester, and may not be able to form gel at lower content. If there are too many oil-soluble groups, the transparency and the water-soluble properties of the product would be lost.

The aqueous compositions comprising the polyester of present invention have a series of special properties. The aqueous composition can be a highly elastic water gel. The aqueous composition may has a thixotropic property and has a high yield stress. Moreover, the aqueous composition comprising the polyester of present invention can be a gel that is sprayable (i.e., sprayable gel) due to its thixotropic property, although the gel is not flowable.

The polyester of present invention is a novel and economic thixotropic thickener. It is also biodegradable, skin friendly and environmentally friendly. The raw materials of the polyester can be widely available from various sources, and is nontoxic. Furthermore, unlike conventional thickeners, the thickening effect of the polyester of present invention is not substantially affected by salts, thus can be more stable. The polyester of present invention can be widely used in applications including household care such as detergent, and so on.

Other advantages of the present invention would be apparent for a person skilled in the art upon reading the specification.

Brief Description of Drawings

Figure 1 shows the infra-red (IR) spectrum of the polyester prepared in Example 1.

Figure 2 shows a high-elastic gel comprising the polyester prepared in Example 1 of the present invention, and it can be easily sprayed like a sprayable liquid.

Figure 3 shows the viscosity of the polyester aqueous solution when the content of the polyester produced in Example 3 increase from 1wt. -%to 3wt. -%.

Figure 4 shows the viscosity of the polyester solution when the amount of NaCl increased from 0 to 5 wt. -%.

Detailed description of the invention

The invention is now described in detail by the following examples. The scope of the invention should not be limited to the embodiments of the examples.

In the following examples, the conditions for the Gel Permeation Chromatography (GPC) tests were as follows:

Column: TSKgel SuperMultipore HZ-M x 4

Flow rate: 0.35 mL/min

Detector: RI (refractive index)

Concentration: 5 mg/mL

Solvent: THF (tetrahydrofuran)

Calibration Standard: Polystyrene

EXAMPLE 1

In a five-neck flask equipped with an agitator, 280g PEG-240 and 28g C36 dimer acid (molar ratio of PEG and dimer acid was 1: 2) were added and heated with stirring under nitrogen atmosphere. Then 1wt. -%benzene sulfonic acid based upon the total weight of the raw materials was added as the catalyst after the above ingredients had been melted. Then the temperature of esterification reaction was raised to 160℃, and the generated water was distilled under low pressure below 20mbar. The reaction was held for 5 h, then cooled down to obtain the product. Finally, around 290g product was obtained. The product was analyzed by GPC. According to GPC analysis, the product was a polyester obtained from PEG and C36 dimer acid, and the average number x of the repeat unit in formula (I) was 2. The main end groups of the product were -COOH.

Relative molecular mass distribution of dimeric fatty acid PEG polyester was as follows,

	M _w	M _w/M _n
Example 1	22628	1.659

The product was analyzed with IR. As shown in Figure 1, a new peak (1732cm ^-1) appeared in the IR spectrum of the polyester prepared in example 1. This new peak is the characteristic absorption band of ester bond. This indicates that the reaction was successful.

EXAMPLE 2

280g PEG-240 and 23g C36 dimer acid (molar ratio of PEG and dimer acid was 2: 3) were stirred under 80℃ under nitrogen atmosphere, then 1wt. -%benzene sulfonic acid was added as the catalyst. The temperature of the reaction was kept on 140℃ and the pressure of the reaction was lowered to 20 mbar. After 6 hours, the temperature was cooled down and around 290g product was obtained. The product was analyzed by GPC _. According to GPC analysis, the average number x of the repeat unit in formula (I) was 3. The main end groups of the product were -COOH.

	M _w	M _w/M _n
Example 2	29558	1.546

A detailed analysis of the relative molecular mass distribution was as follows,

EXAMPLE 3

280g PEG-480 was put into a flask and heated with 30g C36 dimer acid at 80℃ under nitrogen atmosphere. And this time molar ratio of PEG and dimer acid was 1: 4, 1wt. -%benzene sulfonic acid was added after the mixture melted. Then the mixture was kept reacting under stirring for 5 hours at 160℃, and the generated water was distilled below 20mbar. Around 300g final product was obtained after cooling. The product was analyzed by GPC _. According to GPC analysis, the average number x of the repeat unit in formula (I) was 1, and the main end groups of the product were -COOH.

	M _w	M _w/M _n
Example 3	17717	1.587

EXAMPLE 4

280g PEG-480 and 12g C36 dimer acid (molar ratio of PEG and dimer acid was 2: 3) were charged into a flask, and heated until the mixture was melted. Then the 1wt. -%benzene sulfonic acid was charged into the reactor and the pressure of the reaction was lowered to 20 mbar. After that, the reactor was heated to 140℃, and the reaction was maintained at this temperature and below 20mbar for 6 hours. At last, the mixture was cooled down and the around 280g product was obtained. The product was analyzed by GPC _. As the GPC analysis result showed, the average number x of the repeat unit in formula (I) was 1-2. The main end groups of the product were -COOH.

	M _w	M _w/M _n
Example 4	33234	1.522

A detailed analysis of the relative molecular mass distribution was as follows,

EXAMPLE 5

280g PEG-240 and 37g C36 dimer acid (molar ratio of PEG and dimer acid was 2: 5) were charged into a flask, and heated until the mixture was melted. Then the 1wt. -%benzene sulfonic acid and 0.5wt. -%tocopherol was charged into the reactor and the pressure of the reaction was lowered to 20 mbar. After that, the reactor was heated to 160℃, and the reaction was maintained at this temperature and below 20mbar for 3 hours. Then 7g glycerol was added as an end-capping agent and the reaction was continued at 140℃ with low pressure (20mbar) for 3 hours. At last, the mixture was cooled down and the around 280g product was obtained. The product was analyzed by GPC _. As the GPC analysis result showed, the average number x of the repeat unit in formula (I) was 1-2. The main end groups of the product were -COOH before reaction with the end-capping agent.

	M _w	M _w/M _n
Example 5	16883	3.278

A detailed analysis of the relative molecular mass distribution was as follows,

EXAMPLE 6

280g PEG-240 and 37g C36 dimer acid (molar ratio of PEG and dimer acid was 2: 5) were charged into a flask, and heated until the mixture was melted. Then the 1wt. -%benzene sulfonic acid and 0.1wt. -%tocopherol was charged into the reactor and the pressure of the reaction was lowered to 20 mbar. After that, the reactor was heated to 160℃, and the reaction was maintained at this temperature and below 20mbar for 3 hours. Then 62g

Alkanol IC 20 (Isocteth-20) was added as an end-capping agent and the reaction was continued at 160℃ with low pressure (20mbar) for 3.5 hours. At last, the mixture was cooled down and the around 320g product was obtained. As the GPC analysis result showed, the average number x of the repeat unit in formula (I) was 1-2. The main end groups of the product were -COOH before reaction with the end-capping agent.

	M _w	M _w/M _n
Example 6	18584	4.151

A detailed analysis of the relative molecular mass distribution was as follows,

Application Examples

EXAMPLE 7

The test of thixotropic effect of polyester was performed according to the method below.

1. Dissolve a polymer in water within a beaker to prepare an aqueous polyester mixture containing a certain amount of polyester based on the total weight of the aqueous polyester mixture;

2. Fill in this aqueous polyester mixture into a sprayer; and

3. Test the spray capability of the aqueous polyester mixture.

The polyester polymer prepared in Example 1 was dissolved in water to prepare an aqueous polyester mixture containing 2.5wt. -%of polyester based on the total weight of the aqueous polyester mixture. The test of thixotropic effect showed that the aqueous polyester mixture was a highly elastic gel with a thixotropic effect.

As shown in Figure 2, this gel can be sprayed just like a liquid or a solution with a low viscosity, although it could not flow even the bottle was reversed.

The polyester polymers prepared in Examples 2-6 were also tested according to the method above and each of the polyester polymers showed good thixotropic effect and the gel of each of the polyester polymers can be sprayed just like a solution with a low viscosity.

EXAMPLE 8

Solutions comprising 1.0, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, and 5.0wt. -%, respectively of solid polyester polymers of Example 3 in water were prepared and investigated for their viscosity. The experiments were conducted at 20℃, and the viscosity measure used BROOKFIELD instrument with 93#rotor.

In the concentration range of 1.0-5.0 wt. -%of polyester, the composition behaved as a clear and highly elastic gel, it provided viscosity ranging from hundreds to hundreds of thousands. As shown in Figure 3, when the content of the polyester produced in Example 3 increase from 1wt. -%to 3wt. -%, the viscosity of the polyester aqueous solution increase from 0mpa. s ^-1 to around 50000mpa. s ^-1. When the polyester content was above 3wt. -%, the viscosity was too large to measure.

EXAMPLE 9

Solutions comprising 0, 3, and 5wt. -%, respectively of NaCl, 2 wt. -%of solid polyester polymers of Example 3 in water were prepared and investigated for their viscosity. As shown in Figure 4, the polyester is not sensitive to salt.

EXAMPLE 10

A malodor absorber was prepared according to the formulation below.

Table 1 Malodor absorber

Note: *Zinc ricinoleate based malodor absorber with biocidal agent, commercially available from Evonik Industries AG.

Preparation: blend dye and TEGO

B 80 in water; add the solid thickener and soak for ～12 hours, and finally stir till homogeneous.

The appearance was a clear gel. The malodor absorber can be used as a 2 in 1 deodorant &disinfectant, with good portability. It was sprayable due to its shear thinning property.

EXAMPLE 11

A furniture polish was prepared according to the formulation below.

Table 2 Furniture polish

Note: *Organic modified siloxane o/w emulsion with avocado oil, commercially available from Evonik Industries AG.

Preparation: blend all ingredients while stirring.

The appearance was a white gel. The furniture polish had excellent gloss and color enhancement, dust and water repellent. In addition, it was ready to use and was sprayable due to its shear thinning property.

EXAMPLE 12

A disinfectant gel was prepared according to the formulation below.

Table 3 Disinfectant gel

Note: *N-alkyl aminopropyl glycine

Preparation: blend

WK30 in water; add the solid thickener and soak for ～12 hours, and finally stir till homogeneous.

The appearance was a clear gel. The disinfectant gel was ready to use and was sprayable due to its shear thinning property.

As used herein, terms such as "comprise (s) " and the like as used herein are open terms meaning 'including at least' unless otherwise specifically noted.

All references, tests, standards, documents, publications, etc. mentioned herein are incorporated herein by reference. Where a numerical limit or range is stated, the endpoints are included. Also, all values and subranges within a numerical limit or range are specifically included as if explicitly written out.

The above description is presented to enable a person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, this invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. In this regard, certain embodiments within the invention may not show every benefit of the invention, considered broadly.

Claims

Use of a polyester to produce a thixotropic composition or a thixotropic product, or as a thixotropic thickener, wherein the polyester is a water-soluble polymer and is represented by the general formula (I) :

wherein R ¹ represents H or CH ₃, and wherein R ¹ may be the same or different in structure repeat units of -CH ₂CH (R ¹) -O-, e.g., R ¹ may be all H, or comprise both H and CH ₃ and R ¹ comprises more than 50, 60, 70, 80, 90, 95, 98, or 99 molar %of H referring to all R ¹ in the polyester molecule;

R ² and R ³ may be the same or different, and each independently represents an hydrocarbylene group selected from the group consisting of saturated or non-saturated, branched, long-chain hydrocarbylene groups with a carbon atom number from 10 to 50, preferably from 18-40, more preferably from 30-40; wherein R ² may be the same or different in separate structure repeat units of -C (O) -R ²-C (O) -;

R ⁴ represents Rx, or -CH ₂CH (R ¹) -OH;

Rx each independently represents H or Ry, Ry each independently represents an end-capping group;

n is a number ranging from 80-1200, for example 100-1200, preferably 120-1200, more preferably from 120-800; even more preferably from 200-500; and

x is a number ranging from 1-10, preferably from 2-6, for example 1-5, 1-4, and 1-3.
The use of claim 1, wherein Ry is such an end-capping group that the polyester with Ry is water-soluble, preferably, polyester containing Ry is water-soluble and is not an ionic compound.
The use of claim 1, wherein HORy is selected from the group consisting of a monohydric alcohol, a polyhydroxy compound, and a polyether compound, for example a polyhydroxy compound, a branched long chain alcohol, an alkoxylated branched long chain alcohol, or a mixture thereof.
The use of claim 1, wherein the polyester is a dimer fatty acid polyester.
Use of a polyester to produce a thixotropic composition or a thixotropic product, or as a thixotropic thickener, wherein the polyester is prepared according to a method comprising the step of esterification reaction of a bifunctional hydroxyl compound and a bifunctional carboxylic acid,

wherein the bifunctional hydroxyl compound may be represented by general formula (II) ,

wherein R ⁵ represents H or CH ₃; wherein R ⁵ may be the same or different in structure repeat units of -CH ₂CH (R ⁵) -O-, e.g., R ⁵ may be all H, or comprise both H and CH ₃ and R ⁵ comprises more than 50, 60, 70, 80, 90, 95, 98, or 99 molar %of H referring to all R ⁵ in the polyester molecule; and

m is a number ranging from 100-1200, preferably 120-1200, more preferably from 120-800; even more preferably from 200-500;

wherein the bifunctional carboxylic acid may be represented by general formula (III) :

wherein R ⁶ represents an hydrocarbylene group selected from the group consisting of saturated or non-saturated, straight or branched, hydrocarbylene groups with a carbon atom number from 10 to 50, preferably from 18-40, more preferably from 30-40.
A household care aqueous composition comprising a polyester, or a thixotropic product comprising the household care aqueous composition, wherein the polyester is a water-soluble polymer and is represented by the general formula (I) :

wherein R ¹ represents H or CH ₃, and wherein R ¹ may be the same or different in structure repeat units of -CH ₂CH (R ¹) -O-, e.g., R ¹ may be all H, or comprise both H and CH ₃ and R ¹ comprises more than 50, 60, 70, 80, 90, 95, 98, or 99 molar %of H referring to all R ¹ in the polyester molecule;

R ² and R ³ may be the same or different, and each independently represents an hydrocarbylene group selected from the group consisting of saturated or non-saturated, branched, long-chain hydrocarbylene groups with a carbon atom number from 10 to 50, preferably from 18-40, more preferably from 30-40; wherein R ² may be the same or different in separate structure repeat units of -C (O) -R ²-C (O) -;

R ⁴ represents Rx, or -CH ₂CH (R ¹) -OH;

Rx each independently represents H or Ry, Ry each independently represents a carboxyl protecting group;

n is a number ranging from 80-1200, for example 100-1200, preferably 120-1200, more preferably from 120-800; even more preferably from 200-500; and

x is a number ranging from 1-10, preferably from 2-6, for example 1-5, 1-4, and 1-3.
The composition or product of claim 6, wherein Ry is such a carboxyl protecting group that the polyester with Ry is amphipathic and water-soluble.
The composition or product of claim 6, wherein HORy is selected from the group consisting of a polyhydroxy compound, a branched long chain alcohol, an alkoxylated branched long chain alcohol, or a mixture thereof.
The composition or product of claim 6, wherein the polyester is a dimer fatty acid polyester.
A household care aqueous composition comprising a polyester, or a thixotropic product comprising the household care aqueous composition, wherein the polyester is prepared according to a method comprising the step of esterification reaction of a bifunctional hydroxyl compound and a bifunctional carboxylic acid,

wherein the bifunctional hydroxyl compound may be represented by general formula (II) ,

wherein R ⁵ represents H or CH ₃; wherein R ⁵ may be the same or different in structure repeat units of -CH ₂CH (R ⁵) -O-, e.g., R ⁵ may be all H, or comprise both H and CH ₃ and R ⁵ comprises more than 50, 60, 70, 80, 90, 95, 98, or 99 molar %of H referring to all R ⁵ in the polyester molecule; and

m is a number ranging from 100-1200, preferably 120-1200, more preferably from 120-800; even more preferably from 200-500;

wherein the bifunctional carboxylic acid may be represented by general formula (III) :

wherein R ⁶ represents an hydrocarbylene group selected from the group consisting of saturated or non-saturated, straight or branched, hydrocarbylene groups with a carbon atom number from 10 to 50, preferably from 18-40, more preferably from 30-40.