WO2015079451A1

WO2015079451A1 - Alkylphenol ethoxylates and a process for preparing the same

Info

Publication number: WO2015079451A1
Application number: PCT/IN2014/000046
Authority: WO
Inventors: Rajshekhar GHOSH; Ashis Ranjan BANDYOPADHAYA; Raskshvir JSRA
Original assignee: Reliance Industries Limited
Priority date: 2013-11-29
Filing date: 2014-01-22
Publication date: 2015-06-04
Also published as: IN2013MU03755A; WO2015079451A8

Abstract

The present disclosure provides C₁₆ alkylphenol ethoxylates represented by formula (I): The present disclosure also provides a process for the preparation of C₁₆ alkylphenol ethoxylates from octene rich stream.

Description

ALKYLPHENOL ETHOXYLATES AND A PROCESS FOR PREPARING THE SAME

FIELD OF THE DISCLOSURE

The present disclosure relates to alkylphenol ethoxylates and a process for preparing the same.

BACKGROUND

Alkylphenol ethoxylates(APEs) are non-ionic surfactants obtained by ethoxylation of alkylphenols. They are used as emulsifiers for emulsion polymerization, as detergents and in pesticides.

Ethoxylates are typically produced by using a base catalyst such as sodium hydroxide and potassium hydroxide. US20080132728 discloses a continuous process for the production of alkylphenol ethoxylates from an alkylphenol in the presence of a double metal cyanide ("DMC") catalyst.

The two most commercially available APEs are nonylphenol ethoxylates (NPE) and octylphenol ethoxylates (OPE).

NPEs represent approximately 80% to 85% of the volume of APEs. NPEs, are used in a wide variety of applications including detergents, cleaners, degreasers, dry cleaning aids, petroleum dispersants, emulsifiers, defoaming agent, wetting agents and adhesives.

NPEs are hydrophilic ("water-attracting") at one end of the molecule and hydrophobic ("water-avoiding") at the opposite end. The hydrophilic "head" attracts water and the hydrophobic "tail" attracts poorly soluble substances, such as oils and greases. This ability to simultaneously attract water and hydrophobic substances makes NPEs useful in the surfactant applications.

Additionally, it is used as phosphate antioxidants for rubber and plastics and as lube oil additives. l Nonoxynol-9 (NPE) is also used as a spermicide in contraceptives. It is generally used as the active ingredient in several spermicidal creams, jellies, foams, gels, films, and suppositories.

Nonylphenol ethoxylates (NPEs) are released into the aquatic environment to a large extent. Though NPEs are less toxic than Nonylphenol (NP), they cause toxicity problems to aquatic organisms. Further, in the environment NPEs degrade to more environmentally persistent NP.

Considering the hazardous and potential ecological effects due to manufacturing, processing, distribution and use of NP and NPEs, researchers have focused on alternatives for NPEs.

The main alternatives for NPEs also include alcohol ethoxylates and glucose-based carbohydrate derivatives such as alkylpolyglucoside, glucamides, and glucamine oxides.

These surfactants may be substituted for NPEs for specific applications. However, the market acceptance of these alternatives depends on a number of factors including cost and performance in the intended use.

Accordingly, there is felt a need for novel Alkylphenol ethoxylates which are highly effective as a surfactant at low concentration while being less toxic compared to conventional ethoxylates such as nonylphenyl ethoxylate.

OBJECTS

Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as follows:

It is an object of the present disclosure to provide novel Alkylphenol ethoxylates.

It is another object of the present disclosure to provide novel Alkylphenol ethoxylates having enhanced surfactant activity. It is still another object of the present disclosure to provide novel Alkylphenol ethoxylates which exhibit low toxicity.

It is yet another object of the present disclosure to provide a simple process for the preparation of novel Alkylphenol ethoxylates.

It is a further object of the present disclosure to provide an economic process for the preparation of novel Alkylphenol ethoxylates from side stream or byproduct stream of petrochemical/polymer plant.

Other objects and advantages of the present disclosure will be more apparent from the following description which is not intended to limit the scope of the present disclosure.

SUMMARY The present disclosure provides a Cj₆ alkylphenol ethoxylate of formula I:

Formula I wherein, wherein R and R' are independently C₃ to C₁₂ straight or branched alkyl group; R" is H or Ci-C_9> the sum of carbon atoms of R, R' and R" being equal to 15; and n being a whole number between 1 and 100.

Typically, the HLB value of said ethoxylate ranges between 4 and 20.

Typically, the CMC value of said ethoxylate at 25°C ranges between 1 and 100 ppm.

Typically, the surface tension of said ethoxylate at 1% actives and 25°C ranges between 10 and 50 dynes/cm.

Typically, the cloud point of said ethoxylate at 1 wt % actives aqueous solution is >60

In accordance with another aspect of the present disclosure there is provided a process for the preparation of C i6 alkylphenol ethoxylate of formula I;

wherein, wherein R and R' are independently C₃ to C₁₂ straight or branched alkyl group; R" is H or Ci-C₉₎ the sum of carbon atoms of R, R' and R" being equal tol5; and n being a whole number between 1 and 100, said process comprising the following steps:

- subjecting a C₈ stream comprising at least two octenes selected from the group consisting of 1-octene, 2-octene, 3-octene and 4-octene to dimerization or oligomarization to obtain Ci₆-olefin;

- alkylating phenol with said Ci6-olefin to obtain C₎ alkylphenol of formula II;

formula II wherein R and R' are independently C₃ to C₁₂ straight or branched alkyl group; R" is H or CrC₉ and the sum of carbon atoms of R, R' and R" being equal tol 5, and

- ethoxylating said G₁₆ alkylphenol to obtain C]₆ alkylphenol ethoxylate of formula I.

Typically, the toxicity of the C 16 Alkylphenol of formula II is lesser by a factor of at least 20 as compared to nonylphenol.

Typically, C₁₆ alkylphenol of formula II is selected from the group consisting of

Typically, the dimerization or oligomarization is carried out in the presence of a zeolite catalyst having Si/Al ratio ranging between 12 and 80 in their H+ form.

Typically, the dimerization or oligomarization is carried out at a temperature ranging between 100 and 127 °C

Typically, the alkylation is carried out at a temperature ranging between 75 and 130 °C in the presence of a catalyst selected from the group consisting of macroreticular resins made of styrene divinylbenzene copolymers having HSO₃ functional group with a concentration of acid sites ranging between 4.5 and 5.5 eq/ g and which can tolerate operating temperature of > 125 °C in their dry form.

In one embodiment said C₈ stream is a by-product stream containing at least two octenes obtained from a plant selected from the group consisting of a petrochemical plant and a polymer plant.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

Figure 1 illustrates 13C NMR spectrum of alkylphenol; Figure 2 illustrates Distortionless Enhancement by Polarization Transfer (DEPT) spectra of alkylphenol; and

Figure 3 illustrates 13C NMR spectrum of grade 2 sample (Ci₆ alkylphenol ethoxylate) of the present disclosure.

DETAILED DESCRIPTION

The family of hexadecylphenol is less known and barely studied. Only one isomer, namely 4-hexadecylphenol (CAS NO. 2589-78-8) of this family has been studied. In 4-hexadecylphenol, hexadecyl unit is connected to the phenol by the first carbon of the alkyl chain. The other known and commercially available alkylphenols are octylphenol, nonylphenol and dodecylphenol ethoxylates.

The present disclosure provides alkylphenol ethoxylates which are highly effective as a surfactant at low concentration compared to conventional ethoxylates such as nonylphenyl ethoxylate. The corresponding alkylphenol is less toxic as compared to the conventional nonylphenol.

The present disclosure particularly provides hitherto unknown alkylphenol ethoxylates having a branched C;₆ alkyl unit.

C]₆ alkylphenol ethoxylate in accordance with the present disclosure is represented by formula I:

Formula I

_. wherein, wherein R and R' are independently C₃ to 0_]2 straight or branched alkyl group R" is H or C_rC_9; the sum of carbon atoms of R, R' and R" being equal tol5; and n being a whole number between 1 and 100.

In accordance with the present disclosure Ci₆ alkylphenol ethoxylate is synthesized from a mixture of Ci₆ olefins where the double bond is present in an internal position and not using a terminal or alpha olefin. In accordance with the present disclosure octene rich stream is used to synthesize a mixture of C₎₆ olefins with double bond at an internal position and not an alpha olefin.

In the first step, a mixture of octenes is converted into Ci₆ olefin having a double bond at an internal position. In the next step, phenol is alkylated with the obtained C|₆ olefin to get alkylphenol. Finally, alkylphenol is ethoxylated to get alkylphenol ethoxylates.

The generated alkylphenol ethoxylates are found to exhibit enhanced surfactant properties. The surfactant properties are measured and compared against nonylphenol ethoxylates.

It is found that in terms of surfactant property it shows critical micellar concentration (CMC) properties at l/3^rd of the concentration as compared to conventional ethoxylates such as nonylphenyl ethoxylate of similar HLB values.

As each molecule of the surfactant of the present disclosure has low concentration of phenol unit as compared to the nonylphenol analogue, it is expected to show lower toxicity as compared to the nonylphenol counterparts.

The C i6 alkylphenol ethoxylates of the present disclosure are characterized by the following properties:

- HLB value : ranging between 4 and 20; - CMC value: ranging between 10 and 25 ppm at 25°C;

- surface tension: ranging between 30 and 35 dynes/cm at 1% actives, 25°C ; and

- cloud point: >60 °C , 1 wt. % actives aqueous solution;

In accordance with the present disclosure the toxicity of the C 16 Alkylphenol is lesser by a factor of at least 20 as compared to nonylphenol.

In accordance with the present disclosure novel alkylphenol ethoxylates are synthesized from an octene rich by-product stream obtained from a petrochemical plant or a polymer plant. The stream used is devoid of octylphenol and nonylphenol.

In one exemplary embodiment the process for the preparation of C₁₆ alkylphenol ethoxylate of formula I;

Formula I wherein, wherein R and R' are independently C₃ to C₁₂ straight or branched alkyl group; R" is H or Q-C^ the sum of carbon atoms of R, R' and R" being equal to 15; and n being a whole number between 1 and 100, involves the following steps:

A C₈ stream comprising at least two octenes selected from the group consisting of 1 - octene, 2-octene, 3-octene and 4-octene is subjected to dimerization or oligomarization to obtain C^-olefin.

The dimerization or oligomarization is carried out in the presence of a zeolite catalyst having Si/Al ratio ranging between 12 and 80 in their H+ form, and at a temperature ranging between 100 ⁰ C and 127°C.

Examples of such zeolites include but are not limited to CBV712, CBV720, CBV760 and CBV780.

In the next step, phenol is alkylated with the obtained Ci -olefin to obtain C₁₆ alkylphenol of formula II.

formula II wherein R and R' are independently C₃ to C_\2 straight or branched alkyl group; R" is H or C1-C9 and the sum of carbon atoms of R, R' and R" being equal tol5.

The alkylation is carried out at a temperature ranging between 75 and 130 °C in the presence of a catalyst selected from the group consisting of macroreticular resins made of styrene divinylbenzene copolymers having HSO₃ functional group with a concentration of acid sites ranging between 4.5 and 5.5 eq/Kg and which can tolerate operating temperature of > 125 °C in their dry form. Examples of catalyst include but are not limited to Amberlyst catalysts in the dry form such as Amberlyst 15dry, Amberlyst 35dry and Amberlyst 36dry.

The alkylphenol is characterized by various techniques including but not limited to 13C NMR and DEPT. (Figure 1 and figure 2)

The 13C NMR indicated that the alkylphenol consists of approximately 11% ortho alkylphenol and 89% para alkylphenol. The para alkylphenol in this case can be between 99% - 75% and the remaining being ortho alkyl phenol. The alkyl section of the alkylphenol consists of C, CH and CH₂ units and thus leads to the structures represented below.

In accordance with the present disclosure C₁₆ alkylphenol of formula II includes but is not limited to

Finally, C_{! 6} alkylphenol ethoxylates of formula I are obtained by ethoxylating the Cj₆ alkylphenols using ethylene oxide.

The present disclosure is further ^* illustrated herein below with the help of the following examples. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

Three grades of the Ci₆ alkylphenol ethoxylate were prepared. The Grade 2 and 3 were water soluble.

a) Grade 1 : contains 6.5 moles of EO.

b) Grade 2: contains 13.5 moles of EO (RIL AP 13.5 EO)

c) Grade 3: contains 18.8 moles of EO (RIL AP 18.8 EO)

Example 1:

Dimerisation of octenes:

In a 2L round bottom flask, 1000 g of octene feed and 100 g of the zeolite (CBV 720/CBV 760) were taken and heated at 120 °C for 6 hours. Stirring was stopped and the supernatant liquid was taken, weighed and diluted in n-hexane for GC analysis. After the reaction, the material was filtered and the filtrate was distilled on a rotary evaporator to remove unreacted octenes. The residue obtained was the dimer.

Alkylation of phenol with the C16 olefins:

In a 5 L Buchi metal reactor fitted with a heating jacket and hot oil circulation, 1500 g of dimer, 1650 g of phenol and 225g of the Amberlyst™ 35 dry catalyst were taken and heated at 100°C for 6 hours with stirring at 400 RPM. Stirring was stopped and the entire material was drained out from the bottom. The raw product was filtered and the filtrate was collected and distilled under vacuum in a rotary evaporator to remove phenol. This was subsequently distilled on a mantle where the material was maintained within 180 °C with a vacuum of 4 mbar to remove unreacted dimer. The final alkylphenol product was obtained in the form of a residue, which was decolorized by overnight stirring with activated charcoal and filtering.

Ethoxylation of the C16 alkylphenol:

In a 10L metal reactor fitted with a mechanical stirrer and a vacuum line, 1800g of - C16-alkylphenol and a solution of 7g (0.39 wt. % with respect to alkylphenol) of KOH in 7g of distilled water were added. The obtained reaction mixture was heated under stirring to 130°C. At this stage the reactor was evacuated to a vacuum level of 10mm of Hg for one hour to remove all the water present. Vacuum was then released with the introduction of nitrogen gas and ethylene oxide was introduced into the reactor from a bomb, which was placed on a balance to determine EO consumption from the reduction in weight. The reaction mixture was heated to 140 - 155°C with continued stirring and the pressure inside the reactor varied from 2.5 to 3 kg. One kg of the product, which was pale brown in color, was withdrawn from the reactor when 1330g of EO was consumed. This corresponds to a product with alkyl phenol to EO mole ratio of 1 : 5.35. Ethoxylation was further continued and the next one kg sample was withdrawn, when another 1005g of EO was consumed, resulting in a pale brown product with the alkylphenol to EO ratio of 1 : 12.47. Ethoxylation was further continued till another 485g of EO was consumed, giving rise to a pale brown solid product with 17.55 moles of EO attached to one mole of the alkyl phenol.

Comparison of properties of grade 2 and grade 3 against commercially available nonylphenol ethoxylate is provided herein below.

aCritical Micelle Concentration, ppm at 25°C; Surface tension: dynes/cm at 1% actives, 25°C; ^c Cloud point: °C, 1 wt% actives aqueous solution; ^d Ross-Miles foam height: mm at 0.1 wt% actives, 25°C, initial/ 5 minute; ^e Cylinder shake foam height: mm at 0.1 wt% actives, 25°C, initial/ 5 minute. The alkylphenol ethoxylates were analysed by a variety of techniques that include 13C NMR, quantitative 13C NMR and GPC. The HLB values and the structural entities were confirmed by these techniques. A representative quantitative 13C NMR spectrum of grade 2 sample is shown in figure 3.

It is known that APEOs are widely used in cleaning products and as industrial process aids. The spectrum of applications range from dispersing agents in paper and pulp production to emulsifying agents in latex paints and pesticides formulations, flotation agents, industrial cleaners (metal surfaces, textile processing, and food industry), cold cleaners for cars, and household cleaners. The majority of APEOs are used in aqueous solutions; therefore, they are discharged into municipal and industrial waste waters which enter sewage treatment plants. During the different steps of sewage treatment a complex biodegradation process of APEOs takes place, leading to the formation of several biorefractory metabolites. The degradation products 4-alkylphenol diethoxylate (AP2EO), 4-alkylphenol monoethoxylate (AP1EO), [(4- alkylphenoxy)ethoxy] acetic acid (AP2EC), (4-alkylphenoxy)acetic acid (API EC), and 4-alkylphenols formed by shortening of the hydrophilic ethoxy chain are persistent, strongly lipophilic, and more toxic than the parent compounds. Acute toxicity data of NP to aquatic organisms range from 0.18 to 5.0 mg L^"1 dependent on species and experimental conditions. In comparison, toxicities of NP9/10EO to fish are 5.0-1 1.0 mg L^"1. The release of these highly toxic compounds via secondary effluents or sewage sludge could be harmful to the aquatic or terrestrial environment. (Thiele et al, Chem. Rev. 1997, 97, 3247-3272)

In view of this, the toxicity of the alkylphenol of the present disclosure was measured and compared against commercially available nonylphenol. The protocol used was as per OECD 203 guidelines for "Acute fish Toxicity - Fixed Dose procedure". As per Guidelines OECD 203, the total length of the fish recommended was 2.0 ± 1.0 cm. All the fish obtained were allowed to acclimatize to the experimental laboratory conditions for a period of 12 days before they were used for the testing. The light cycle was of 12 to 16 hours. Temperature for the appropriate species in the tank water was as per the guidelines and the oxygen concentration was at least 80 % of air saturation value.

In C16 Alkyl Phenol at 100 mg/1, the mortality observed was less than 50 percent, within 24 hours, at 50 mg/1 dose there was one mortality within 48 hours. No mortality was observed amongst the animals administered by the dose lOmg/1 to 0.1 mg/1 even after 96 hours. Under similar test conditions in the Nonylphenol sample, at dosage level of 100 mg/1 to 5 mg /l in the sample 1 mortality observed was hundred percent within the first 24 hours. The mortality rate of Nonyl Phenol was statistically significant when compared to C16 Alkyl Phenol. The oral LC₅₀ of the product C16 Alkyl Phenol in fish is found to be more than 100 mg/1. This indicates that the C16 alkylphenol is significantly less toxic as compared to nonylphenol by a factor of 20 or higher.

TECHNICAL ADVANCE

- The present disclosure provides novel Ci₆ alkylphenol ethoxylates having enhanced surfactant properties and their corresponding Alkylphenol was found to have significantly lower toxicity.

- Ci6 alkylphenol ethoxylates of the present disclosure can be synthesized from a mixture of octenes rather than pure alpha-olefin.

- The process of the present disclosure forms C_]6 olefins with the double bond at an internal position and not an alpha olefin.

- C₁₆ alkylphenol ethoxylates of the present disclosure can be synthesized from a side or by-product octene rich stream of polymer or petrochemical plant.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. The use of the expression "a", "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters,^, dimensions and quantities fall within the scope of the disclosure and the claims unless there is a statement in the specification to the contrary.

While certain embodiments of the disclosure have been described, these embodiments have been presented by way of examples only, and are not intended to limit the scope of the disclosure. Variations or modifications in the composition of this disclosure, within the scope of the disclosure, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this disclosure.

Claims

CLAIMS:

1. A C] 6 alkylphenol ethoxylate of formula I:

Formula I wherein, wherein R and R' are independently C₃ to C₎₂ straight or branched alkyl group; R" is H or C]-C_9; the sum of carbon atoms of R, R' and R" being equal to 15 ; and n being a whole number between 1 and 100.

2. The C]₆ alkylphenol ethoxylate of formula I as claimed in claim 1, characterized in that its HLB value ranges between 4 and 20.

3. The Ci6 alkylphenol ethoxylate of formula I as claimed in claim 1, characterized in that its CMC value at 25°C ranges between 1 and 100 ppm.

4. The C i6 alkylphenol ethoxylate of formula I as claimed in claim 1, characterized in that its surface tension at 1% actives and 25°C ranges between 10 and 50 dynes/cm. The Gi6 alkylphenol ethoxylate of formula I as claimed in claim 1, characterized in that its cloud point at 1 wt. % actives aqueous solution is >60 °C.

A process for the preparation of C₁₆ alkylphenol ethoxylate of formula I;

Formula I wherein, wherein R and R' are independently C₃ to C₁₂ straight or branched alkyl group; R" is H or Ci-C_9; the sum of carbon atoms of R, R' and R" being equal tol5; and n being a whole number between 1 and 100, said process comprising the following steps: a. subjecting a Gg stream comprising at least two octenes selected from the group consisting of 1-octene, 2-octene, 3-octene and 4-octene to dimerization or oligomarization to obtain C ^-olefin; b. alkylating phenol with said C₁₆-olefin to obtain C₁₆ alkylphenol of formula

II;

formula II wherein R and R' are independently C₃ to C_J2 straight or branched alkyl group; R" is H or C_rC₉ and the sum of carbon atoms of R, R' and R" being equal to 15, and c. ethoxylating said C_]6 alkylphenol to obtain Ci₆ alkylphenol ethoxylate of formula I.

7. The process as claimed in claim 6, wherein the toxicity of C₁₆ alkylphenol of formula II is lesser by a factor of at least 20 as compared to nonylphenol.

8. The process as claimed in claim 6, wherein C₁₆ alkylphenol of formula II is selected from the group consisting of

22

23

9. The process as claimed in claim 6, wherein the dimerization or oligomarization is carried out in the presence of a zeolite catalyst having Si/Al ratio ranging between 12 and 80 in their H+ form.

10. The process as claimed in claim 6, wherein the dimerization or oligomarization is carried out at a temperature ranging between 100 and 127 °C

1 1. The process as claimed in claim 6, wherein the alkylation is carried out at a temperature ranging between 75 and 130 °C in the presence of a catalyst selected from the group consisting of macroreticular resins made of styrene divinylbenzene copolymers having HSO₃ functional group with a concentration of acid sites ranging between 4.5 and 5.5 eq Kg and which can tolerate operating temperature of > 125 °C in their dry form.

12. The process as claimed in claim 6, wherein said C₈ stream is a by-product stream containing at least two octenes obtained from a plant selected from the group consisting of a petrochemical plant and a polymer plant.