JPS6017320B2 - Wax-containing petroleum fuel oils with addition of polymer mixtures effective to improve cold flow properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the use of oil-soluble aliphatic copolymers, such as ethylene-vinyl acetate copolymers and oil-soluble derivatives of aromatic copolymers, which have the properties of nucleating agents for wax crystallization. Regarding additive combinations.

A variety of polymers useful as medium-quality crabgrass pour point depressants made from ethylene have been described in the patent literature.

These pour point laxatives include copolymers of vinyl esters of lower fatty acids such as vinyl acetate and ethylene (US Pat. No. 304,847y), copolymers of ethylene and alkyl acrylates (Canadian Patent No. 67, Iso75), ), terpolymers of ethylene, vinylester, and alkyl fumarate (U.S. Pat. Nos. 3,304,261 and 33,413)
09), polymers of ethylene (British Patent No. 848777)
Belgian Patent No. 707371 and U.S. Patent No. 33373), chlorinated polyethylene (Belgium Patent No. 707371 and US Pat.
No. 13), etc. Homopolymers and copolymers of olefins, such as alkyl esters of unsaturated dicarboxylic acids (e.g., polymers of dialkyl fumarate and vinyl acetate) and copolymers of olefins and said esters,
Polymers having alkyl groups in the range of 6 to C,8 are known in the art primarily as lubricating oil pour point depressants and/or VI improvers. For example, U.S. Patent No. 23797
No. 28 teaches olefin polymers as lubricating oil pour point depressants, U.S. Pat. No. 2,460,035 teaches polyfumarates, U.S. Pat. And US Pat. No. 2,542,542 teaches copolymers of olefins such as octadecene and maleic anhydride esterified with alcohols such as lauryl alcohol in lubricating and heating oils. Also, U.S. Patent No. 3,726,653
The No. 2004-2016 No. 2003-2011 shall include natural fuels, such as residual oil and flash crabmide fuel (
These fuels teach synergistic flow reduction combinations of various of the above two polymers in relatively large amounts of waxes having a molecular weight of 2M or higher on average. ing.

Cold flow of medium-quality crabmeat fuel is described in U.S. Patent No. 3,275,427.
Molecular weight (molecular weight) such as ethylene-vinyl acetate according to the No.
Improved by an additive combination of a 1000-3000 ethylene copolymer and a lauryl acrylic acid ester polymer. GB 1374051 teaches that by appropriate selection of a combination of a nucleating agent or wax growth stimulator and a wax crystal growth inhibitor, the cold flow properties of hydrocarbon medium crab product oils can be very satisfactorily controlled. .

U.S. Pat. No. 3,449,259 discloses certain physical and chemical properties of those heavier than gasoline liquefied hydrocarbons, such as fuel oils and lubricating oils, preferably having an initial boiling point of about 260°C. It teaches that the properties are "significantly improved by the addition of small amounts of copolymers which impart stability and detergency to the liquid hydrocarbon."

The copolymer has a molecular weight in the range of about 500 to 150,000 and is formed from substantially equimolar parts of maleic anhydride and a Q-olefin such as ethylene, propylene, isobutylene or styrene. The carboxyl groups of the copolymer are esterified with an aliphatic alcohol to render the copolymer oleaginous, and substantially all of the remaining carboxyl groups are imidized. According to the invention, a large proportion i.e. more than 5% by weight of distillate petroleum fraction and 'a' of aliphatic copolymers 1-2 which act as nucleating agents for wax crystallization in said distillate; an aromatic copolymer consisting of an oil-soluble derivative of a copolymer of a 'b' vinyl aromatic monomer and an ethylenically unsaturated polar monomer, in parts by weight of about 500 to
about 0.001 to 0.5% by weight of a composition for improving flow and filtration properties, comprising 1 to 10 parts by weight of Mn having a number average molecular weight (Mn) of about 5,000 or about 500 to about 15,000; A fuel composition is provided comprising:

Moreover, it is preferable that the weight ratio of (a/{b} is within the range of 1/20 to 5/1.For the present invention, when Mn' is 500 to about 15,000, gas phase osmotic pressure method is used. (VP
O) and above 15,000 by P. osmometry. More particularly, the aromatic copolymers can be characterized as essentially alternating copolymers of styrene and acrylates, methacrylates or maleic anhydrides.

In the latter case, the anhydride group resulting from maleic anhydride is derivatized with either an aliphatic alcohol and/or an amine, as will be discussed in more detail below. The above compositions have been found to prevent oil gelation and effectively stimulate wax crystal size in cast hydrocarbon oils having endpoints above 370 qo. For ease of handling, concentrates of 1 to 6% by weight of the above additive combination in 40 to 9% by weight of key oils, such as kerosene, can be produced.

The nucleating agent for wax crystallization is soluble in the crab oil at temperatures above the saturation temperature of the "wax-like" components of the crab oil, but upon cooling of the crab oil, the distillate oil is dissolved. As the temperature approaches the saturation point of the core "wax-like" components, the crab oil is heated to a point slightly above the core saturation temperature, e.g.
The aliphatic conjugate material gradually separates as it cools from a point above 00F (preferably about 50F above) to a lower temperature. The term "saturation temperature" is defined as the lowest temperature at which crystallization of the solute, ie, petroleum wax, cannot begin even if crystallization induction methods are used. Thus, the wax nucleating agent increases the temperature at which the onset of wax crystallization from the crab oil (e.g., fuel oil) occurs during cooling, and increases the temperature above the saturation temperature of the wax in the oil. is soluble in the oil at , but begins to separate from the oil as the oil temperature approaches the saturation temperature.

Preferred polymeric wax nucleating agents are each segmented by a hydrocarbon, halogen or oxyhydrocarbon side chain and contain 1 mole of ethylenically unsaturated ester monomer (mixture of unsaturated esters). Approximately 3 per proportion
-4 is a copolymer with a polymethylene primary mirror containing a 4 to 20 molar proportion of ethylene (usually prepared by free radical polymerization, which may result in some branching). The optimal polymer is ethylene and 0.3
It is a copolymer with ~12 mol % of pinyl acetate. These copolymers generally have about 500 to 5000 polymers.
is a molecular weight (Mn) within the range of about 1,500 to about 30,000
has. The unsaturated ester monomer copolymerizable with ethylene has the general formula [this] and R. is hydrogen or C, ~C. 7 preferably a C, to C8 such as a C, to C4 straight or branched alkyl group], preferably a vinyl ester of a C2 to C5 monocarboxylic acid.

Examples of such esters include vinyl acetate, vinyl isobutyrate, vinyl laurate, vinyl myristate, vinyl palmitate, and the like. These preferred copolymers are readily prepared by conventional polymerization techniques using free radical initiators, such as those described in US Pat. No. 3,048,47.

Other monomers that can be copolymerized with ethylene include C3-
C. Mention may be made of 6Q-monoolefins, which may be branched or straight chain, such as propylene, isobutene, n-octene-1, isooctene-1, n-decene-1, dodecene-1, etc.

Still other monomers include vinyl chloride (although essentially the same results can be obtained by chlorinating polyethylene to a chlorine content of, for example, about 10-35% by weight), acrylonitrile, acrylamide, and the like. Copolymerization is usually accomplished using a Ziegler-Natta catalyst or the like prior to free radical initiation. Preferred English polymers are:
It can be manufactured as follows.

That is, a solvent and a simple substance other than ethylene (5 to 5% by weight of the total amount) are charged into a stainless steel pressure-resistant container equipped with a fly extractor. The temperature of the pressure vessel is then adjusted to the desired reaction temperature, e.g. 70-250o, and ethylene to the desired pressure, e.g. 700-2500 sig, usually 900-700o.
Put pressure on the political sig. During the reaction period, an initiator (usually dissolved in a solvent so that it can be pumped) and additional amounts of monomer charges other than ethylene, such as vinylester, can be added to the vessel continuously or at least periodically. can. Also, during this reaction time, as ethylene is consumed in the polymerization reaction, additional ethylene is supplied through a pressure control regulator to maintain the desired reaction pressure fairly constant throughout. After completion of the reaction (a total reaction time of 1/4 to 1 field hour is usually sufficient), the liquid phase is drained from the reactor and the solvent and other volatile components in the reaction mixture are stripped and co-condensed. Leaves the polymer as a residue. For ease of handling and subsequent oil mixing, the polymer is dissolved in light mineral oil to form a concentrate containing typically 10-6% by weight of copolymer. Usually, based on 100 parts by weight of the copolymer to be produced, approximately 50 to 120 parts by weight are used.
100 to 60 parts by weight of solvent, usually a hydrocarbon solvent such as benzene, hexane, cyclohexane, t-butyl alcohol, etc., and about 1 to 2 parts by weight of initiator are used.

The initiator is a group of compounds that undergo decomposition at elevated temperatures to produce radicals, such as peroxide or azo type initiators, including acyl peroxides of C2-C, 8-branched or straight-chain carboxylic acids; selected from other common initiators. Specific examples of such initiators include dibenzoyl peroxide, di-tertiary butyl peroxide, t-butylberbenzoate, t-butylberoctoate, t-
-phthyl hydroperoxide, Q.Q'-azodiisobutyronitrile, dilauroyl peroxide and the like. Dilauroyl peroxide is preferred when the polymer is made at low temperatures, e.g. 70-135 oO, while di-tert-butyl peroxide is preferred at higher polymerization temperatures. The second component of these flow improvers for distillate oils contains a monopynyl aromatic monomer such as styrene and usually 8 to 52 carbons, preferably 10 to 32 carbons and generally carbon, hydrogen. and at least one ethylenically unsaturated monomer consisting of one or more elements selected from the group consisting of oxygen, nitrogen, halogen and sulfur.

Monopynyl aromatic monomers useful in this invention are preferably C8-C2, including Q-methylstyrene and the preferred types of styrene.

It is a monopynyl aromatic compound. In a preferred sense, these polar monomers have the general formula [in the above formula, R2 and R4
are independently selected from the group consisting of hydrogen, halogen and C, to C,2 alkyl groups such as methyl, and R3 is carboxy (-COOH), cyano (-CN), hydroxymethyl (1C-H), Ruboalkoxy (one COOR)
, alkoxymethyl (1CH2-○-R6), methylhydrocarpylketone (1CQ-CO-R6) and half of a cyclic dicarboxylic anhydride (as in maleic anhydride), R5 is selected from the group consisting of hydrogen, carboxy (1COOH), sia/(1CN) and carbalkoxy (1COOR6), and R
6 can be represented by C, -C24 selected from the group consisting of straight and branched alkyl, arylalkyl and cycloalkyl groups.

The oil-soluble derivative of the copolymer of a monovinyl aromatic monomer and a polar monomer is obtained by yielding the polar monomer and subsequently copolymerizing or deriving the copolymer. I can do it.

In the case of acidic polar monomers such as acrylic acid or methacrylic acid, it is customary to first derivatize them, for example into esters, amides or esteramides, and then copolymerize them with vinyl aromatic monomers. On the other hand, when maleic anhydride is used as a copolymer, it is preferred to copolymerize it with a monovinyl aromatic monomer and then introduce the copolymer thus already formed into the copolymer. . Derivatives include alcohols containing from 1 to 6 hard carbon atoms, thus forming esters, amines containing from 1 to 6 carbon atoms and from 1 to 12 nitrogen atoms, thus forming amides, or any This can be achieved using said alcohols and amines in proportions thus forming esteramide derivatives. A particularly useful group are monovinyl aromatic monomers having about 8 to 2 carbon atoms in the molecule, such as styrene and dicarboxylic acid materials (either anhydrides such as maleic anhydride or dicarboxylic monomers such as fumaric or maleic acid). It is an oil-soluble derivative of a copolymer with either an acid or

Typically, styrene-maleic anhydride copolymers are formed by copolymerization of substantially equimolar amounts of unibases. The resulting copolymer, like an acrylate copolymer, has a
It should have an Mn in the range of ~150,000.
Yet another advantageous group of oil-soluble ghost story conductors is C8-C2.

With mono/vinyl aromatic monomers such as styrene, in the formula R represents hydrogen or methyl, R' represents an alkyl group of 8 to 24 carbon atoms, and N' represents an alkyl group of 1 to 6 carbon atoms. is an acrylate copolymer with an acrylic or methacrylic acid derivative. The alkyl group of R' is preferably linear in nature and has 12 to 18
methyl and ethyl branches can be tolerated. Examples of the acrylic or methacrylic monomer from which the copolymer is derived include alkyl acrylate, alkyl methacrylate, alkylamino acrylate, and alkylamino methacrylate, such as lauryl acrylate, lauryl methacrylate, N.N-dimethylaminoethyl methacrylate, and the like. Can be mentioned. Alcohols suitable for use in preparing esters of copolymers of monovinyl aromatic monomers, such as styrene, and dicarboxylic acid materials, such as maleic anhydride, generally include:
It is an aliphatic alcohol having about 1 to 6 hard carbons per molecule.

Saturated aliphatic alcohols containing 6 to 22 carbon atoms per molecule are preferred. Examples of alcohols suitable for use in preparing esters include straight chain alcohols such as ethyl, propyl, butyl, hexyl, octyl, lauryl, octadecyl, eicosyl, docosyl, tricosyl, tetracosyl, bentacosyl, hexacosyl, and the like. Alcohol is an example. Polyols containing from about 2 to about IN hydroxy groups such as glycerol, alkylene glycols such as dipropylene glycol, trimethylolnathane, bentaerythritol, and the like may also be used. In making long chain esters, commercially available mixtures of alcohols consisting essentially of saturated alcohols of the desired chain length can be used.

One such mixture is available under the trade name "Beheny".
1) Alcohol" and is a mixture of C,6 to C24 alcohols derived from natural sources.

Amine compounds useful in the amination/imidization of copolymers according to the present invention include about 1 to 6 solids in the molecule, e.g.
Mention may be made of mono- and polyamines of ˜2 total carbon atoms and about 1 to 12 nitrogen atoms, such as 2 to 6 nitrogen atoms, and the amines may be hydrocarbyl amines or other groups such as hydride.

It may be a hydrocarbyl amine containing an oxy group, an alkoxy group, an amide group, an imidazoline group, or the like. Preferred amines are aliphatic primary and secondary amines, including polyamines. It is possible to replace up to 25 mol% of the amines with primary or secondary aromatic amines. Preferred amines include those of the following formula. In the above formula, R and R' are C, ~C25 straight chain or branched alkyl group, C,
~C,2 alkoxy C2-C6 alkylene group, C2-C
, 2-hydroxy or aminoalkylene group and C, ~C,
independently selected from the group consisting of 2 alkylamino C2-C6 alkylene groups, R' may be hydrogen;
S is a number from 2 to 6, preferably from 2 to 4, and t is 0
~1 Castle order is preferably a number from 2 to 6.

Non-limiting examples of suitable amine compounds include mono- and ditallowamines, 1,2-diaminoethane, 1,3-diaminoprobane, 1,4-diaminobutane, 1,6-diaminohexane, diethylenetriamine, triethylenetetramine. , tetraethylenebentamine, 1,2-propylene diamine, di(1,2-propylene)triamine, di(1,3-propylene)triamine, N,N-dimethyl-1,3-diami/propane, N.
N-di(2-aminoethyl)ethylenediamine, N・N
-di(2-hydroxyethyl)-1,3-propylene diamine, 3-dodecyloxypropylamine, N-dodecyl-1,3-propanediamine, trishydroxymethylmethylamine, diisopropanolamine and jetanolamine.

Other useful amine compounds include cycloaliphatic diamines such as 1,4-di(aminomethyl)cyclohexane, and imidazolines and the general formula [wherein G is hydrogen and 1-
omega-aminoalkylene groups of 3 carbon atoms, and p is an integer from 1 to 4]. .

Commercially available mixtures of amine compounds can be advantageously used. For example, one method for making alkylene amines is to react an alkylene dihalide (such as ethylene dichloride or propylene dichloride) with ammonia (which results in a complex mixture with alkylene groups) to produce diethylene amines. This includes forming compounds such as triamines, triethylenetetramine, tetraethylenebentamine and piperazine isomers. A low cost poly(ethyleneamine) compound having a composition approximately of tetraethylenebentamine is available under the trade name "Polyamine 400 (PA-400)" (sold by Jefferson Chemical Company, New York City, NY, USA). Below are available in the market. The same material can be made by polymerization of aziridiso, 2-methylaziridine and azetidine. Still other amines such as polyethers or sulfides separated by heteroatom chains can be used.

Also, a compound having 2 to 3 hydroxy groups such as trishydroxymethylaminomethane, diisopropanolamine, 2-amino-2-methyl-1,3-propanediol, 2-amino/-2-ethyl-1,3-propanediol, etc. Also included are primary and secondary amines.

Process for producing monovinyl aromatic copolymers and their esterification with alcohols and amines and/or
Amidation and/or imidization is described in U.S. Patent No. 261, Group 4.
If necessary, reference is made to the teachings of that patent, which are adequately described in the prior art of No. 5.

Polymerization of monovinyl aromatic monomers and ethylenically unsaturated esterified (including partial esterified) monomers can be carried out using free radical initiation as previously described herein for the preparation of nucleating agents for wax crystallization. This can be done by polymerization techniques. The hydrocarbon oil treated with the additive of the present invention is a wax-containing oil with a boiling point in the range of 120 to 500°C.

The present invention provides high end point fuels that are unresponsive to conventional flow improvers, i.e., end boiling points (AS
TM-1160) is particularly useful for cold flow treatment of fuels such as those with TM-1160).

Example The following materials were used:

Polymer 1 Polymer 1 is a combination of ethylene and vinyl acetate having a Mn of about 4100, a vinyl acetate content of 9% by weight and a specific viscosity of 0.37, prepared as described in British Patent No. 1374051. It is a copolymer of

This copolymer is also used in U.S. Patent No. 3 as copolymer K.
No. 961,916 (corresponding to the above-mentioned British patent).

Polymer A Polymer A is a styrene-maleic anhydride copolymer esterified with an aliphatic alcohol and amidated with an alkyl amine dissolved in mineral oil and from Monsanto: Chemical Company, USA. “HiTec6
It is sold as 72''.

This means that 3% by weight of the copolymer has about 14,800 Mn, and 78.3% by weight carbon, 10.9% by weight hydrogen and 0.9% by weight. * Believed to consist of % nitrogen by weight. Moreover, the linear primary alcohol of the copolymer has 10
It appears to have ~1 milk solids of carbon. Polymer B Polymer B
is a copolymer of styrene and lauryl methacrylate dissolved in natural oil.
The product name “Santopou” was introduced by the company.
r) Sold as “C”.

fuel The properties of the tested crabmeat fuel oils are summarized in Table 1 below.

TABLE 1 Distillate Fuel Various blends of Polymer 1 and Polymers A and B in fuel were prepared by simply dissolving the polymer in the fuel oil.

This was done while warming and heating the oil and polymer to about 90°C, for example if the polymer itself was added. In other cases, the polymer was simply added to the fuel in the form of an oil concentrate, usually about 5% by weight of the polymer dissolved in the silt. The blends were then tested for their cold flow properties in the tests described below.

Cold Furnace Blockage Point Test (CFPPT) The cold flow characteristics of the blend are tested by the Cold Furnace Blockage Point Test (CFPPT).
PPT).

This test was carried out by the “Jokawa Institute of
Ute of Petrole (Vol.52)
, No. 510, June 1966, pp. 173-185). Briefly, 40' samples of the oil to be tested are cooled in a bath maintained at about -134°C. Periodically (starting from 2° C. above the cloud point and every 1° C. drop in temperature), the cooled oil is tested for its ability to flow through a fine screen over a period of time. This cold property is tested in an apparatus in which an inverted funnel is attached to the lower end of the pipette so that this inverted funnel is positioned below the surface of the oil to be tested. Across the mouth of the funnel, approximately 0.45in2
A 350 mesh screen with an area of is stretched. Each periodic test is initiated by applying a vacuum to the upper end of the pipette, thereby drawing oil into the pipette through the screen to the 20' oil mark.
The test is repeated for each 1° C. drop in temperature until no oil fills the pipette into the 6-bait litter. The results of the test are reported as the temperature in °C at which the oil no longer fills the pipette in the specified time. British Furnace Test (FT) In this test, a 200% sample of oil is cooled at a rate of 10 F'hr from 5.6 qo above its true cloud point to 2.8 qo below its true cloud point, and at this temperature The oil is passed through a filter element equipped with a screen under a vacuum of 12n water columns.

English furnace quality is reported by the finest screen in which at least 90% of the sample passes under suction of 12n of water in a time not exceeding 29 sand. ``The true cloud point, which is used as a reference point at T, is 20
This is the temperature at which wax crystal formation is first observed when cooling at a rate of 0F/hr. The prepared blends and test results are summarized in Table 2 below.

Table 2 Effectiveness of Polymers in Fuels The synergistic results obtained by the teachings of the present invention are evident from Table 2 above, e.g. in oil A the blend of Example 2 gives a CFPPT of -120; The blend of Example 4 gave 110 qo of CFPPT, whereas the blend of Examples 2 and 4
A good 50/5 blend of -1 o (Example 6) gives a significantly lower CFPPT of -1 o (similarly, Examples 2, 3 and 5
synergism is evident in the results, whereby the CFPPT is reduced to 113 qo), and in oil B, the blend of Example 7 gives a CFPPT of -3°C and the blend of Example 9 gives a CFPPT of -9°C. whereas the 50/5 blend of Example 7 and Example 9 gives -16o
(See Example 11).

Claims (1)

[Scope of Claims] 1. Ethylene having a boiling point within the range of 120 to 500°C and a final boiling point higher than about 370°C, and further comprising: (a) ethylene which acts as a nucleating agent for wax crystallization in the distillate; and C_1
-C_8 A copolymer of a saturated aliphatic monocarboxylic acid with a vinyl ester, having an average molecular weight (Mn) of about 500 to 50,000 and a molecular weight of 3 to 3 per mole fraction of the vinyl ester.
an aliphatic copolymer having a 40 molar proportion of ethylene;
b) C_8 to C_2_0 monovinyl aromatic monomer;
more essentially an ester of an ethylenically unsaturated acid selected from the group consisting of maleic anhydride, acrylic acid and methacrylic acid with a saturated, essentially true chain alcohol having from 6 to 22 carbon atoms. , and about 500~
and an aromatic oil-soluble copolymer having a number average molecular weight (Mn) within the range of about 50,000, and the weight ratio (a)/(b) of 1
0.001 to 0.5% by weight, based on the weight of the total composition, of a synergistic flow improving combination ranging from 1/20 to 5/1. Distillate petroleum fuel oil. 2. The fuel oil according to claim 1, wherein the vinyl ester is vinyl acetate. 3. The fuel oil according to claim 1 or 2, wherein the aromatic monomer is styrene and the ester is maleic anhydride ester. 4. The fuel oil according to claim 1 or 2, wherein the aromatic monomer is styrene and the ester is methacrylate. 5. The fuel oil according to claim 4, wherein the methacrylate is lauryl methacrylate.