Compositions for improving softness of paper towel and / or towel products

Abstract

The invention relates to a composition for improving softness of a paper towel and / or towel product comprising: a lignocellulosic fiber; water; and a hydrophobic softening agent comprising a reaction product of: (1) at least one diamine and / or polyamine, (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic capping agent. The reaction product comprises at least about 25 moles % of hydrophobic substitution of the hydrophobic capping agent, based on the total moles of active amine sites of the reaction product. Further, the invention relates to a method of improving softness of a paper towel and / or towel product comprising combining a lignocellulosic fiber, water, and a hydrophobic softening agent; and producing a paper towel and / or towel product.

Description

Technical Field

[0001] In general, this disclosure relates to a composition for improving the softness of paper towels and / or towel products. More specifically, this disclosure relates to the use of a particular composition that is free of nonionic surfactants, contains a high percentage of hydrophobically substituted hydrophobic softeners, and has improved toxicity characteristics. Background Technology

[0002] Fabric softeners are commonly used to improve the softness and feel of bath towels, hand towels, and facial tissues. One of the most widely used tissue softeners is made using a condensation reaction process. First, one mole of diethylenetriamine (DETA) reacts with 1.5 to 2.0 moles of a fatty acid (e.g., oleic acid, based on 0.75 to 1.0 equivalents of the two primary amines present on DETA). The reaction products are a mixture of monoamides and diamides. Optionally, the process can be modified by additional heating and the application of a vacuum to induce cyclization of the intermediate material, thereby forming an imidazoline moiety. The remaining primary and secondary amines are then reacted with a quaternizing agent, diethyl sulfate (DES) or dimethyl sulfate (DMS), to form a cationic quaternary amine, thus completing the synthesis.

[0003] Two aspects of the chemical structure of softeners affect their performance. First, the cationic charge on the softener interacts strongly with the anionicly charged lignocellulosic fibers used to manufacture bath towels, hand towels, and facial tissues. This interaction helps retain the softener in the tissue during sheet formation at the wet end of the paper machine. Second, the reaction with DES tends to lower the final melting point of the softener, making it easier to emulsify in the tissue mill.

[0004] Despite the commercial success of such products over the years, the use of diethyl sulfate / dimethyl sulfate quaternizing agents has come under increasing regulatory scrutiny, particularly in California, where California Proposition 65 warnings are required. Furthermore, these products are classified as GHS Classification Category 1 in terms of their toxicity to aquatic organisms.

[0005] The mixture of monoamides and diamides formed by the reaction of oleic acid with DETA is theoretically an effective paper softener. Unfortunately, amides and imidazolines are waxy solids at room temperature, making them difficult to emulsify in a paper towel mill. Furthermore, even at high emulsification temperatures (e.g., 60-80°C), only emulsions with a low solids percentage (e.g., 2-3%) can be prepared. Even at low solids percentages, such emulsions are not stable for more than a day. For these reasons, such compositions are unsuitable for use.

[0006] Therefore, opportunities for improvement still exist. Furthermore, other desirable features and characteristics of this disclosure will become apparent from the following detailed description and appended claims, taken in conjunction with the accompanying drawings and background information. Summary of the Invention

[0007] This disclosure provides a composition for improving the softness of tissue paper and / or towel products. The composition comprises lignocellulose fibers; water; and a hydrophobic softener comprising a reaction product of: (1) at least one diamine and / or polyamine; (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic end-capping agent selected from fatty acids, fatty acid esters, fatty acyl chlorides, fatty alkyl halides, epoxides of hydrocarbons, carboxylic anhydrides of hydrocarbons, and combinations thereof, any one or more of which have 4 to about 40 carbon atoms. Based on the total molar number of active amine sites in the reaction product, the reaction product comprises at least about 25 mol% hydrophobic substitution of the hydrophobic end-capping agent.

[0008] This disclosure also provides a method for improving the softness of paper towels and / or towel products. The method includes the following steps: providing lignocellulosic fibers; providing water; providing a hydrophobic softener; combining the lignocellulosic fibers, water, and hydrophobic softener; and using the combination of lignocellulosic fibers, water, and hydrophobic softener to produce paper towels and / or towel products. Attached Figure Description

[0009] The present disclosure will now be described in conjunction with the accompanying drawings, wherein like reference numerals denote like elements, and

[0010] Figure 1A A bar graph representing the surface softness evaluation results of Example 1;

[0011] Figure 1B This is a bar graph representing the deflection evaluation results of Example 1.

[0012] Figure 1C This is a bar graph representing the tensile strength evaluation results of Example 1.

[0013] Figure 2 A table showing the composition and physical properties of Example D;

[0014] Figure 3 A table showing the composition and physical properties of Example E;

[0015] Figure 4 A table showing the composition and physical properties of Example F;

[0016] Figure 5 A table showing the composition and physical properties of Example G;

[0017] Figure 6 A table showing the composition and physical properties of Example H; and

[0018] Figure 7 This is a table showing the composition and physical properties of Example I. Detailed Implementation

[0019] The following specific embodiments are merely exemplary and are not intended to limit the current compositions or methods. Furthermore, they are not intended to be construed as being limited by any theories presented in the foregoing background or the following specific embodiments.

[0020] Embodiments of this disclosure generally relate to compositions for improving the softness of tissue paper and / or towel products, and methods for forming thereof. For the sake of brevity, conventional techniques related to papermaking may not be described in detail herein. Furthermore, the various tasks and process steps described herein can be combined into a more comprehensive procedure or process with additional steps or functions not described in detail herein. Specifically, the various steps in manufacturing towel and tissue paper products are well known; therefore, for the sake of brevity, this document will only briefly mention many conventional steps or omit them entirely without providing well-known process details.

[0021] In this disclosure, in various embodiments, the term "about" may describe values ​​of ±0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10%. Furthermore, in various non-limiting embodiments, it is contemplated that all values ​​described herein may alternatively be described as approximate or "about" that value. All isomers and chiral options (if applicable) of each compound described herein are expressly contemplated herein for use in various non-limiting embodiments.

[0022] This disclosure provides a composition for improving the softness of tissue paper and / or towel products. The composition comprises lignocellulose fibers; water; and a hydrophobic softener comprising a reaction product of: (1) at least one diamine and / or polyamine; (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic end-capping agent selected from fatty acids, fatty acid esters, fatty acyl chlorides, fatty alkyl halides, epoxides of hydrocarbons, carboxylic anhydrides of hydrocarbons, and combinations thereof, any one or more of which have 4 to about 40 carbon atoms. Based on the total molar number of active amine sites in the reaction product, the reaction product comprises at least about 25 mol% hydrophobic substitution of the hydrophobic end-capping agent. Furthermore, the composition does not require the inclusion of a nonionic surfactant to be stable and effective. Therefore, the composition may or may not contain a nonionic surfactant. Each component will be described in more detail below.

[0023] This disclosure also provides a method for improving the softness of paper towels and / or towel products. The method includes the following steps: providing lignocellulosic fibers; providing water; providing a hydrophobic softener; combining the lignocellulosic fibers, water, and hydrophobic softener; and using the combination of lignocellulosic fibers, water, and hydrophobic softener to produce paper towels and / or towel products. Each step will be described in more detail below.

[0024] Throughout this disclosure, the terms "consists essentially of" or "consisting essentially of" generally describe embodiments that contain no or less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1% by weight of one or more fibers, polymers, additives, surfactants, etc., and / or combinations thereof, not described herein or described herein as optional. Alternatively, various embodiments may contain none, i.e., contain zero weight percentage of one or more fibers, polymers, additives, surfactants, etc., and / or combinations thereof, not described herein or described herein as optional.

[0025] Composition

[0026] As described above, this disclosure provides a composition for improving the softness of tissue and / or towel products. Tissue and / or towel products are not particularly limited and can be further defined as toilet paper, face towels, bath towels, etc. The softness of tissue and / or towel products can be determined by any test known in the art.

[0027] For example, in various embodiments, the percentage reduction in tensile strength of tissue and / or towel products can be minimized. As is known in the art, the typical percentage reduction in tensile strength observed can vary considerably depending on the type of product manufactured. Ideally, the percentage reduction in tensile strength should be minimized as much as possible while still maintaining the product's softness. For example, softness is typically increased without compromising the product's structural strength (excluding surface lubrication, which is part of softness). In these types of evaluations, and as further shown in the embodiments, those skilled in the art determine the weakening of the paper sheet by assuming that a weaker sheet will become fluffier and thus softer after the wrinkling process. In many embodiments, the technology of this disclosure has been shown to perform comparably to or better than that of comparative / existing softeners while simultaneously improving regulatory and toxicity characteristics.

[0028] A similar concept applies to determining the relationship between softness and deflection using a tissue softness analyzer (TSA), where deflection typically correlates well with tensile strength loss. Technicians hypothesize that weaker sheets of paper exhibit greater deflection and lower breaking strength.

[0029] In addition, surface softness can be measured. This technique can improve the softness of, for example, any grade of paper towel. However, as those skilled in the art will understand, there is no fixed percentage improvement in softness that is consistent across all grades of paper towels and towels.

[0030] The percentage reduction in tensile strength can be determined using a universal tensile testing machine (such as the Insight5SL manufactured by MTS Systems Corporation). A typical determination is performed as follows: First, a 1-inch x 7-inch test specimen is prepared from the sample to be evaluated. The longitudinal force is gradually applied to the specimen using the tensile testing machine, and the peak strength before breakage is reported. Note the direction in which the specimen is cut. For wrinkled paper sheets, the transverse (CD) breaking strength, or the geometric mean of the transverse and longitudinal (MD) strengths, can be determined. Technicians are familiar with the sample's orientation and its effect on tensile strength. It should be noted that paper moisture affects tensile strength, so samples are typically equilibrated in a constant temperature / humidity chamber before evaluation. Furthermore, it is common practice to correct for strength fluctuations caused by variations in basis weight by normalizing the data relative to a specific basis weight.

[0031] Deflection can be determined using a tissue softness analyzer (such as the Emtec TSA device) specifically designed for measuring and quantifying the tactile properties of tissue products. The sample is placed inside the testing device, secured in a manner similar to mounting a drumhead to a drum. Sufficient tension is applied to the paper sheet to keep it flat and firmly hold the edges in place. The testing device then applies a fixed force in the Z direction, and the magnitude of the deflection exhibited by the sample (TSA-D) is typically measured in mm / N of applied pressure. A higher deflection value indicates a softer paper sheet.

[0032] Surface softness can be determined using a tissue softness analyzer (such as the Emtec TSA device) specifically designed for measuring and quantifying the tactile properties of tissue products. The sample is placed inside the testing device, secured in a manner similar to a drumhead mounted on a drum. Sufficient tension is applied to the paper sheet to keep it flat and firmly hold the edges in place. The testing device then lowers the test probe onto the paper surface. The probe is rotated, and acoustic vibrations are reported using a sensitive microphone array. The instrument then correlates the acoustic response at approximately 7,000 Hz with the surface softness and records this value as the TSA-S7 softness. The acoustic measurement at this frequency is considered to reflect the coefficient of friction on the paper surface; the lower the value, the softer the paper.

[0033] Another method for quantifying softness is using the Thwing-Albert Handle-O-Meter (HOM). Using industry-standard testing methods (such as TAPPI T498), this instrument reports the combined effect of the sample's flexibility and surface friction. This value is directly related to the perceived softness of the tested sample; the smaller the value, the softer the sample. A general overview of the test is as follows: A tissue sample is placed on a flat support with a single narrow slot. The sample is narrower than the slot and extends significantly beyond it on both sides. A penetrator beam then rotates on a cam, engaging the sample and forcing it through the slot. The force required to push the sample through the slot is reported. Generally, rougher and harder samples will produce greater resistance and are typically considered less soft.

[0034] Unbound by theory, it is believed that hydrophobic softeners act as debonders by interacting with lignocellulose fibers and disrupting the hydrogen bonds between them. This subsequently makes the fibers easier to break down, thereby increasing softness.

[0035] The composition may be, contain, consist essentially of, or consist of lignocellulose fibers, water, and a hydrophobic softener.

[0036] In one embodiment, the composition comprises lignocellulose fibers, water, and a hydrophobic softener.

[0037] In another embodiment, the composition consists essentially of lignocellulose fibers, water, and a hydrophobic softener.

[0038] In another embodiment, the composition comprises lignocellulose fibers, water, and a hydrophobic softener.

[0039] In one embodiment, the composition comprises lignocellulose fibers, water, a hydrophobic softener, and one or more of the following additives.

[0040] In another embodiment, the composition consists essentially of lignocellulose fibers, water, a hydrophobic softener, and one or more of the following additives.

[0041] In another embodiment, the composition comprises lignocellulose fibers, water, a hydrophobic softener, and one or more of the following additives.

[0042] In one embodiment, the composition comprises lignocellulose fibers, water, a hydrophobic softener, and a stabilizer kit described below.

[0043] In another embodiment, the composition consists essentially of lignocellulose fibers, water, a hydrophobic softener, and a set of stabilizers described below.

[0044] In another embodiment, the composition comprises lignocellulose fibers, water, a hydrophobic softener, and a set of stabilizers described below.

[0045] Furthermore, it is hereby explicitly considered that all combinations of the above components be used in the various non-limiting embodiments described herein.

[0046] Lignocellulose fiber

[0047] The lignocellulose fiber is not particularly limited and can be any fiber known in the art. For example, the fiber used in this disclosure can be derived from or contained in pulp. Alternatively, the fiber used in this disclosure can be derived from or contained in biomass. Alternatively, the fiber used in this disclosure can be derived from or contained in lignocellulose materials.

[0048] For example, in various embodiments, the biomass utilized may include annual plants and agricultural residues, woody perennial plants, forestry residues, and trees. In various embodiments, biomass may be described as wood or wood fragments. For example, wood may be any type of wood known in the art for pulping processes. For example, wood may include hardwood, softwood, or mixtures thereof. In one embodiment, wood may include predominantly coniferous wood (e.g., spruce, fir, pine, etc.) or predominantly deciduous wood (e.g., eucalyptus, poplar, maple, etc.). Generally, the terms “lignocellulosic material” and / or “biomass” differ from “pulp” as used herein because pulp is typically formed after at least partial digestion of lignocellulosic material / biomass.

[0049] In other embodiments, pulp is used. The pulp is not particularly limited and may include virgin pulp or TMP, NSSC, deinking pulp, or other pulps used for papermaking. Alternatively, the pulp may include OCC pulp or blends of OCC with virgin pulp, deinking pulp, MOW, NSSC, TMP, or other source pulps. Furthermore, the fiber may be cellulosic fiber or cellulose fiber.

[0050] The amount of fiber in the composition is not particularly limited and can vary depending on the measurement time, for example, when the composition is used in a wet fabric or placed on a dryer. In various embodiments, the fiber is present in an amount of about 0.5 to about 3, about 1 to about 2.5, or about 2 to about 2.5 by weight percentage, based on the total weight of the composition. The balance may include water, the softener of this disclosure, and various additives. In various non-limiting embodiments, all values ​​and ranges of values ​​(inclusive and fractional) between the above values ​​are expressly considered herein.

[0051] water

[0052] The amount of water present in the composition is not particularly limited and can vary depending on the measurement time, such as when the composition is used in a wet fabric or placed on a dryer. In various embodiments, water is present in an amount of about 0.1 to about 99, about 1 to about 99, about 5 to about 95, about 10 to about 90, about 15 to about 85, about 20 to about 80, about 25 to about 75, about 30 to about 70, about 35 to about 65, about 40 to about 60, about 45 to about 55, or about 50 to about 55% by weight, based on the total weight of the composition. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (including) the above values ​​are explicitly considered herein.

[0053] It is worth noting that the amount of water in the above composition can be considered independently of the amount of water used in papermaking (e.g., process water), or it can be regarded as the same amount. For example, the composition itself may contain a certain amount of water, which is then added to the process water during the papermaking process, thereby increasing the total amount of water relative to the other components in the composition.

[0054] hydrophobic softener

[0055] Hydrophobic softeners are described as “hydrophobic” because those skilled in the art would consider them to be at least partially immiscible with water. Hydrophobic softeners may be reaction products of, contain, substantially consist of, or consist of reaction products of: (1) at least one diamine and / or polyamine; (2) at least one chain extender having at least two carboxyl groups; and (3) at least one hydrophobic end-capping agent selected from fatty acids, fatty acid esters, fatty acyl chlorides, fatty alkyl halides, epoxides of hydrocarbons, carboxylic anhydrides of hydrocarbons, and combinations thereof, any one or more of which have 4 to about 40 carbon atoms. Each of (1), (2), and (3) is described in more detail below.

[0056] In one embodiment, the hydrophobic softener is the reaction product of (1), (2) and (3).

[0057] In one embodiment, the hydrophobic softener comprises the reaction products of (1), (2) and (3).

[0058] In one embodiment, the hydrophobic softener is essentially composed of the reaction products of (1), (2) and (3).

[0059] In one embodiment, the hydrophobic softener is composed of the reaction products of (1), (2) and (3).

[0060] In hydrophobic softeners, (1) and (2) are typically reacted to form a polyamide oligomer backbone (main chain) and can be reacted with (3) by condensation polymerization methods known in the art. Without being bound by theory, it is believed that the polyamide oligomer backbone forms hydrophilic segments that facilitate emulsification of the hydrophobic softener in water within the composition and may ultimately result in water used in papermaking processes. In various embodiments, the polyamide oligomer backbone comprises one or more cationicly charged secondary or tertiary amine groups that contribute to retention of the hydrophobic softener during sheet formation at the wet end of the paper machine. It is also believed that the hydrophobic softener can act as a surfactant to reduce the surface tension of the water used to form the cellulose paper sheet and soften the resulting product.

[0061] There are no particular limitations on the molar ratio of the reactants. In various embodiments, (1), (2), and (3) react in a molar ratio of about (1 to 3): about 1: about (0.9 to 4). For example, the molar ratio associated with (1) can be about 1 to about 3, about 1.1 to about 2.9, about 1.2 to about 2.8, about 1.3 to about 2.7, about 1.4 to about 2.6, about 1.5 to about 2.5, about 1.6 to about 2.4, about 1.7 to about 2.3, about 1.8 to about 2.2, about 1.9 to about 2.1, or about 2. Furthermore, the molar ratio associated with (2) is about 1, for example, about 0.9 to about 1.1. Furthermore, the molar ratio associated with (3) can be from about 0.9 to about 4, from about 1 to about 3.9, from about 1.1 to about 3.8, from about 1.2 to about 3.7, from about 1.3 to about 3.6, from about 1.4 to about 3.5, from about 1.5 to about 3.4, from about 1.6 to about 3.3, from about 1.7 to about 3.2, from about 1.8 to about 3.1, from about 1.9 to about 3, from about 2 to about 2.9, from about 2.1 to about 2.8, from about 2.2 to about 2.7, from about 2.3 to about 2.6, or from about 2.5 to about 2.5. In other embodiments, the molar ratio is from about (1.5 to 1.75): from about 1: from about (1.25 to 1.5). Typically, these ratios are balanced to improve the self-emulsifying properties of the product while maintaining its ability to impart softness. If the choice of raw materials significantly alters the hydrophilic-lipophilic balance (HLB), the exemplary ratios described above can be adjusted outside the reported range to maintain both qualities. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (including) the values ​​described above are explicitly considered here.

[0062] In various embodiments, the amount of hydrophobic softener used is about 0.1 to about 40, about 0.1 to about 35, about 0.1 to about 30, about 0.1 to about 25, about 0.1 to about 20, about 0.1 to about 15, about 0.1 to about 10, about 0.1 to about 5, about 0.5 to about 10, about 1 to about 10, about 1 to about 9, about 1 to about 8, about 1 to about 7, about 1 to about 6, about 1 to about 5, about 1 to about 4, about 1 to about 3, about 1 to about 2, about 1.25 to about 5, about 1 to about 4.5, about 1 to about 3.5, about 1 to about 3, about 1 to about 2.5 pounds per tonne of fiber or paper. Alternatively, in various embodiments, the amount of hydrophobic softener used is from about 0.005% to about 2%, from about 0.025% to about 0.5%, from about 0.0625% to about 0.25%, or any of the above amounts divided by 2000 pounds and multiplied by 100 to obtain a weight percentage based on the total weight of the fiber or paper. In various embodiments, the hydrophobic softener is diluted, but this is not necessary. For example, the hydrophobic softener can be diluted to, for example, a solution of about 0.25% to about 10%, a solution of about 1% to about 10%, a solution of about 1% to about 5%, or a solution of about 1% to about 2%, etc., and then added. In various embodiments, the hydrophobic softener is diluted when sprayed on wet web or a dryer. In other embodiments, the hydrophobic softener is added in a more concentrated form to the pulp blender just before the wet end of the paper machine. In various embodiments, the hydrophobic softener is diluted to improve distribution and efficiency. In various additional embodiments, dilution is intended to form a diluent of about 0.1 to about 99.9, about 1 to about 99, about 5 to about 95, about 10 to about 90, about 15 to about 85, about 20 to about 80, about 25 to about 75, about 30 to about 70, about 35 to about 65, about 40 to about 60, about 45 to about 55, or about 50 to about 55%. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are explicitly considered herein.

[0063] (1) At least one diamine and / or polyamine

[0064] In other embodiments, (1) may be linear or branched and may contain or not contain cyclic or other functional groups, including additional amine groups, additional amide groups, additional carboxylic acid groups, carbon-carbon double bonds, alcohols, halides, aldehydes, ketones, esters, sulfones, sulfonic acids or other acid derivatives.

[0065] In various embodiments, the polyamide oligomer backbone is formed by a molar excess of primary amine groups. This excess of primary amine groups ensures that sufficient primary amine groups are available for reaction with (3). Typically, the molar ratio of the primary amine group on (1) to the carboxylic acid group on (2) is at least about 10:9, about 9:8, about 8:7, about 7:6, about 6:5, about 5:4, about 4:3, about 3:2, about 2:1, or about 1:1, or any range between the two. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are explicitly considered herein.

[0066] In various embodiments, (1) comprises two primary amine groups. In other embodiments, (1) comprises more than two primary amine groups, such as three or four, or even more. In other embodiments, (1) comprises at least one, such as two, three, four, or more secondary and / or tertiary amine groups. In various embodiments, (1) is selected from diethylenetriamine, triethylenetetramine, tetraethylenepentamine, methyldiaminopropylamine (MBAPA), hexamethylenediamine, and ethylenediamine. In one embodiment, (1) is selected from polyalkyleneamines, polyalkylimines, and combinations thereof. In another embodiment, (1) is selected from diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), dipropylenetriamine (DPTA), tripropylenetetramine (TPTA), tetrapropylenepentamine (TPPA), pentapropylenehexamine (PPHA), dihexamethylenetriamine (DHMTA), methyldiaminopropylamine (MBAPA), hexamethylenediamine, ethylenediamine, and combinations thereof. In another embodiment, (1) is selected from polyethylenepolyamines, polyalkylenepolyamines, and combinations thereof. In a further embodiment, (1) is diethylenetriamine (DETA).

[0067] In other embodiments, (1) can be any polyamine having three or more amine groups and can have a molecular weight up to about 4,000 but typically up to about 800. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (including) the above values ​​are explicitly considered herein.

[0068] Furthermore, (1) may include a small amount of polyamines such as diamines, such as ethylenediamine, less than about 50% by weight. The preparation of these materials is well known in the art and can be prepared by any known method. For example, alkylene dihalides and ammonia can be used to form (1). Commercially available polyalkylene polyamines that can be used can be mixtures of polyalkylene polyamine homologues. For example, polyethylene polyamines can be used. Polyalkylene polyamines having ethylene and propylene groups can also be used. Such mixed polyalkylene polyamines can be readily prepared, for example, by condensing ethylenediamine with one or more proportions of acrylonitrile to form N-cyanoethyl ethylenediamine, which can then be reduced, for example, by catalytic hydrogenation to form the mixed alkylene polyamine.

[0069] Furthermore, (1) can be one or more polyalkylene imines, wherein the alkyl portion of the molecule can have 2 to about 12 carbon atoms, such as polyethylene imine, polypropylene imine, polybutylene imine, etc., and its molecular weight can be about 800 to about 50,000 or higher. These polyalkylene imines can be prepared by any method known to those skilled in the art. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are explicitly considered herein.

[0070] (2) At least one chain extender

[0071] As introduced above, (2) is at least one chain extender having at least two carboxyl groups. In various embodiments, (2) is selected from oxalic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, C36 dimer acid, and combinations thereof. In other embodiments, (2) is selected from acetic acid, glutaric acid, succinic acid, and combinations thereof.

[0072] In various embodiments, (2) may contain 2 to about 40, about 2 to about 38, about 2 to about 36, about 4 to about 34, about 6 to about 32, about 8 to about 30, about 10 to about 28, about 12 to about 26, about 14 to about 24, about 16 to about 22, about 18 to about 20, about 12 to about 20, about 12 to about 18, about 12 to about 16, about 12 to about 14, about 14 to about 18, about 14 to about 16, or about 16 to about 18 carbon atoms. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (including) the above values ​​are explicitly considered herein.

[0073] In various embodiments, the term "chain extender" describes a reactant that reacts with (1) and / or (3) to increase the molecular weight of the reaction product primarily through its bifunctionality, resulting in greater spacing between molecular bonds rather than tight crosslinking that could lead to gelation. The reaction between (1) and (2) can occur at the primary amine groups at the ends of the polyamide oligomer backbone, or at any primary and / or tertiary amines along the polyamide oligomer backbone. In various embodiments, the reaction occurs primarily at the ends of the polyamide oligomer backbone, and the reaction along the polyamide oligomer backbone occurs only to a lesser extent. Some of these compounds may also lead to the formation of imidazolines, as described in more detail below.

[0074] In various embodiments, (2) the chain extender is primarily bifunctional when reacting with (1), but may contain a small amount of multifunctionality, which can react with (1) in a bifunctional manner. In other embodiments, the carbon chain length between the at least two carboxyl groups allows for the production of at least water-dispersible reaction products.

[0075] In various embodiments, (2) is selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and combinations thereof. In other embodiments, (2) is selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, dodecanoic acid, C36 dimer acid, dimethyl glutarate, its diester, and combinations thereof. In other embodiments, (2) is selected from acetic acid, dimethyl glutarate, and combinations thereof.

[0076] (3) At least one hydrophobic end-capping agent

[0077] Referring now to (3), the at least one hydrophobic end-capping agent is selected from fatty acids, fatty acid esters, fatty acyl chlorides, fatty alkyl halides, epoxides of hydrocarbons, carboxylic anhydrides of hydrocarbons, and combinations thereof, any one or more of which have 4 to about 40 carbon atoms.

[0078] In any one or more of the above, the number of carbon atoms can be from about 4 to about 40, from about 6 to about 38, from about 8 to about 36, from about 10 to about 34, from about 12 to about 32, from about 14 to about 30, from about 16 to about 28, from about 18 to about 26, from about 20 to about 24, from about 22 to about 24, from about 18 to about 20, from about 12 to about 20, from about 12 to about 18, from about 12 to about 16, from about 12 to about 14, from about 14 to about 18, from about 14 to about 16, or from about 16 to about 18 carbon atoms. In various non-limiting embodiments, all values ​​and ranges between (including) the above values ​​are explicitly considered to be used herein. It is also believed that hydrophobic endcaps have a softening and "de-adhesive" effect on the resulting tissue from cellulose fibers.

[0079] In one embodiment, the at least one hydrophobic end-capping agent is a fatty acid having about 12 to about 20 carbon atoms, such as about 14 to about 20 carbon atoms, about 14 to about 18 carbon atoms, about 14 to about 16 carbon atoms, about 12 to about 18 carbon atoms, about 12 to about 16 carbon atoms, about 12 to about 14 carbon atoms, about 16 to about 20 carbon atoms, or about 16 to about 18 carbon atoms. In another embodiment, the fatty acid is selected from caprylic acid, nonanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, linoleic acid, oleic acid, and combinations thereof. In yet another embodiment, the fatty acid is selected from stearic acid, oleic acid, and combinations thereof. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are explicitly considered herein.

[0080] Non-limiting examples of fatty acid esters include methyl and / or ethyl esters of caprylic acid, nonanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, linoleic acid, and oleic acid, and combinations thereof.

[0081] Non-limiting examples of fatty acyl chlorides include acyl chlorides of octanoic acid, nonanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, linoleic acid, oleic acid, and combinations thereof.

[0082] Non-limiting examples of aliphatic alkyl halides include monochloro, monobromine, or monoiodide-substituted alkyl chains of octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, dodecane, and docosane, and combinations thereof. Furthermore, substitution can occur at any carbon in the chain, and the chain may contain one or more degrees of unsaturation. Other non-limiting examples may include aromatic alkyl halides, such as benzyl chloride, benzyl bromide, etc.

[0083] Non-limiting examples of hydrocarbon epoxides include 1,2-epoxides of octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, dodecane, and combinations thereof. Additional non-limiting examples include glycidyl ethers of monohydric alcohols based on octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, dodecane, and combinations thereof. Furthermore, substitution can occur at any carbon in the chain, and the chain can also contain one or more degrees of unsaturation. Other non-limiting examples may include glycidyl ethers of aromatic alkyl alcohols such as benzyl alcohol.

[0084] Non-limiting examples of carboxylic anhydrides of hydrocarbons include dimer anhydrides of octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, linoleic acid, and oleic acid, and combinations thereof. Furthermore, the anhydride need not be symmetrically substituted, but those skilled in the art will recognize that asymmetric anhydrides of long-chain and short-chain acids will produce mixtures of substituted products.

[0085] In various embodiments, (3) reacts with (1) and (2) to form a hydrophobic end cap on the polyamide oligomer backbone. The end caps may be the same or different. In various embodiments, the hydrophobic end cap is capable of reacting with primary amine groups on the polyamide oligomer backbone and may be derived from fatty acids, fatty acyl chlorides, epoxides of long-chain hydrocarbons, long-chain alkyl halides or aldehydes, carboxylic anhydrides of long-chain hydrocarbons, or esters of fatty acids. Other examples of hydrophobic end caps capable of reacting with amine groups on the polyamide oligomer backbone are described in U.S. Patent Application 2019 / 0031802, which is expressly incorporated herein by reference in various non-limiting embodiments. In various embodiments, the hydrophobic end cap is derived from fatty acids, such as those used to manufacture alkyl ketene dimers (AKDs) as understood by those skilled in the art. Non-limiting examples of fatty acids used to manufacture AKDs are described in U.S. Patent 4,240,935, which is expressly incorporated herein by reference in various non-limiting embodiments. Non-limiting additional examples of fatty acids used in the manufacture of AKD include: caprylic acid, nonanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, linoleic acid, or oleic acid. In various embodiments, the most typical fatty acids may include: lauric acid, myristic acid, palmitic acid, stearic acid, and / or oleic acid.

[0086] In various embodiments, the hydrocarbon chain of the hydrophobic end cap comprises about 4 to about 40, about 6 to about 38, about 8 to about 36, about 10 to about 34, about 12 to about 32, about 14 to about 30, about 16 to about 28, about 18 to about 26, about 20 to about 24, about 22 to about 24, about 18 to about 20, about 12 to about 20, about 12 to about 22, about 12 to about 18, about 12 to about 16, about 12 to about 14, about 14 to about 18, about 14 to about 16, or about 16 to about 18 carbon atoms. In various non-limiting embodiments, all values ​​and ranges between (including) the above values ​​are explicitly considered herein.

[0087] Typically, based on the total number of moles of active amine sites in the reaction products, the reaction products of (1), (2), and (3) comprise at least about 25 mol% hydrophobic substitution of the hydrophobic capping agent. Those skilled in the art will understand active amine sites as reactive primary and secondary amines that remain after the polyamide-forming condensation reaction between (1) and (2). This is an assumption and does not describe the order of reactions occurring in the process, but rather provides a way of describing the level of hydrophobic substitution. In other embodiments, based on the total number of moles of active amine sites in the reaction products, this amount is about 25 to about 95, about 30 to about 80, about 32 to about 70, about 35 to about 60, about 37 to about 50, or about 38 to about 45 mol% of the hydrophobic capping agent. In various other embodiments, based on the total number of moles of active amine sites in the reaction products, this amount is at least about 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 or more mol% of the hydrophobic capping agent. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the values ​​described above are explicitly considered here.

[0088] In various embodiments, the molar ratio of the hydrophobic end cap to the primary amine groups on the polyamide oligomer backbone is at least about 0.5:1, about 0.75:1, about 0.9:1, about 0.95:1, about 1:1, about 1.1:1, about 1.25:1, about 1.5:1, about 1.75:1, about 1.9:1, or about 2:1 or any range thereof. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are expressly considered herein.

[0089] In various embodiments, based on the weight percentage of the hydrophobically modified polyamide in the formulation to be transported, the percentage of active ingredient of the hydrophobic softener is about 10% to about 100%, about 20% to about 90%, about 30% to about 80%, about 40% to about 70%, or about 50% to about 60%. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are explicitly considered herein.

[0090] imidazoline cyclization adducts

[0091] As described above, in various embodiments, the hydrophobic softener and / or reaction product may be, contain, consist essentially of, or consist of the above-described hydrophobic end-capped polyamide oligomer backbone, wherein one or more imidazoline cyclization adducts are incorporated into the structure. Alternatively, the hydrophobic softener and / or reaction product may be free of imidazoline cyclization adducts, or may contain less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1 weight percentages of imidazoline cyclization adducts based on the total weight of the hydrophobic softener and / or based on the total weight of the composition. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (including) the above values ​​are explicitly considered herein. Those skilled in the art will understand the structure of such imidazoline cyclization adducts.

[0092] In one embodiment, the hydrophobic softener and / or reaction product comprises a hydrophobically capped polyamide oligomer backbone and an imidazoline cyclized adduct.

[0093] In one embodiment, the hydrophobic softener and / or reaction product consists essentially of a hydrophobically capped polyamide oligomer backbone and an imidazoline cyclized adduct.

[0094] In one embodiment, the hydrophobic softener and / or reaction product consists of a hydrophobically capped polyamide oligomer backbone and a variety of imidazoline cyclized adducts.

[0095] In one embodiment, the hydrophobic softener and / or reaction product comprises a hydrophobically capped polyamide oligomer backbone and a variety of imidazoline cyclized adducts.

[0096] In one embodiment, the hydrophobic softener and / or reaction product is essentially composed of a hydrophobically capped polyamide oligomer backbone and a variety of imidazoline cyclized adducts.

[0097] In one embodiment, the hydrophobic softener and / or reaction product consists of a hydrophobically capped polyamide oligomer backbone and an imidazoline cyclized adduct.

[0098] Based on the total number of available sites on the hydrophobic softener and / or reaction product presumably capable of forming imidazoline, the hydrophobic softener and / or reaction product may include any amount of imidazoline cyclization adduct, such as about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95% molar of imidazoline cyclization adduct. In other embodiments, the amount of imidazoline cyclization adduct is about 5 to about 95, about 10 to about 90, about 15 to about 85, about 20 to about 80, about 25 to about 75, about 30 to about 70, about 35 to about 65, about 40 to about 60, about 45 to about 55, or about 45 to about 50% by weight, based on the total weight of the hydrophobic softener and / or reaction product. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are explicitly considered herein.

[0099] Alternatively, the hydrophobic softener and / or reaction product may be free of imidazoline cyclization adducts, or, based on the total number of available sites on the hydrophobic softener and / or reaction product presumably capable of forming imidazolines, may contain less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1% molar of imidazoline cyclization adducts. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are expressly considered herein.

[0100] Nonionic surfactants

[0101] In this disclosure, the compositions may or may not contain nonionic surfactants. In various embodiments, the term "free of" describes an embodiment in which the composition contains less than 5, 4, 3, 2, 1, 0.5, or 0.1% by weight of nonionic surfactant based on the total weight of the composition. Alternatively, the composition may be completely free of nonionic surfactants (i.e., containing about zero weight percentage of nonionic surfactant).

[0102] In various embodiments, the nonionic surfactant is selected from monofatty acid esters and ethers of polyethylene glycol and combinations thereof. However, the nonionic surfactant is not limited to this type and may include any nonionic surfactant known in the art.

[0103] In various embodiments, nonionic surfactants may be included as supplementary additives. For example, the presence of nonionic surfactants can act as adhesive plasticizers / modifiers in desiccant release formulations. However, this disclosure does not rely on the addition of nonionic surfactants to achieve softening properties comparable to or better than conventional fabric softeners containing DES and / or DMS, nor does it rely on nonionic surfactants to achieve product stability.

[0104] additive

[0105] It is also considered that the composition may or may not contain one or more additives. For example, additives may be those routinely added to raw materials in paper or paperboard production, such as processing aids (e.g., retention aids, filter aids, contaminant control additives, flocculants, defoamers, etc.) or other functional additives (e.g., wet strength or dry strength additives, temporary wet strength additives, dyes, fluorescent whitening agents, sizing additives, etc.).

[0106] Stabilizer Kit

[0107] The composition may or may not include a stabilizer kit. Stabilizer kits are typically used to keep the softener in a form easily usable by the customer. Typically, the product remains either a single-phase liquid or a stable (non-settling, non-gelling) emulsion. The viscosity should be low enough to facilitate pumping and easy dilution into process water.

[0108] In various implementation schemes, the stabilizer kit is, contains, is substantially composed of, or consists of acetic acid, propylene glycol, and water.

[0109] In one implementation, the stabilizer kit comprises acetic acid, propylene glycol, and water.

[0110] In another embodiment, the stabilizer kit consists essentially of acetic acid, propylene glycol, and water.

[0111] In a further embodiment, the stabilizer kit consists of acetic acid, propylene glycol, and water.

[0112] As a substitute for or supplement to acetic acid, stabilizer kits may contain lactic acid, glycolic acid, hydrochloric acid, sulfuric acid, phosphoric acid, fatty acids (such as oleic acid), other low molecular weight organic acids, or combinations thereof.

[0113] As a substitute for or supplement to propylene glycol, a stabilizer kit may contain glycerol, dipropylene glycol, alcohols, or combinations thereof.

[0114] In various embodiments, acetic acid, propylene glycol, and water (or any one or more of the above alternatives) are present in the stabilizer kit in a weight ratio, which may be described in one or more sections. For example, in various embodiments, the weight ratio of water to propylene glycol (or any one or more of the above alternatives) may be from about 2:1 to about 1:2, such as about 1:1. In other embodiments, the amount of acetic acid may be selected based on pH, such as from about 4 to about 7, from about 4.5 to about 6.5, from about 5 to about 6, from about 5 to about 5.5, or from about 5.5 to about 6. In other embodiments, the weight ratio of acetic acid, propylene glycol, and water (or any one or more of the above alternatives) is (from about 1 to about 1.5):(from about 1):(from about 0.5 to about 1.5). In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (including) the above values ​​are explicitly considered herein.

[0115] Methods to improve the softness of paper towels and / or towel products

[0116] As described above, this disclosure also provides a method for improving the softness of paper towels and / or towel products. The method includes the following steps: providing lignocellulosic fibers; providing water; providing a hydrophobic softener; combining the lignocellulosic fibers, water, and hydrophobic softener; and using the combination of lignocellulosic fibers, water, and hydrophobic softener to produce paper towels and / or towel products.

[0117] The provisioning step is not particularly limited and can be any step known in the art, such as providing each other independently, providing together as a combination of one or more components, etc. Similarly, the combination step is not particularly limited and can be further defined as providing one or more components individually or sequentially or simultaneously, in an intermittent or continuous manner, in combination with any one or more other components.

[0118] In one embodiment, the combination step is further defined as combining water and a hydrophobic softener with lignocellulose fibers dispersed in the process water.

[0119] In another embodiment, the combination step is further defined as applying water and a hydrophobic softener to the lignocellulosic fibers by spraying, direct contact, or foaming, or by using an application mat.

[0120] In another embodiment, the lignocellulose fibers are in the form of wet-laid fiber material.

[0121] In a further embodiment, the lignocellulose fibers are arranged, optionally together with an adhesive, on a dryer such as a Yankee dryer. In this case, the product can be used as a release agent while also transferring it onto the paper sheet, where it provides a surface softening effect.

[0122] The steps for producing tissue paper and / or towel products using a combination of lignocellulosic fibers, water, and a hydrophobic softener are not particularly limited and may include any one or more steps involved in papermaking as known in the art. A charged (typically cationic) hydrophobic softener may be supplied to the formulation prior to paper web formation, applied directly to a partially dehydrated paper web, or applied in combination of both methods. Furthermore, the hydrophobic softener may be applied as part or all of the Yankee coating kit during the creping process. Alternatively, the hydrophobic softener may be applied to a fully dried creped sheet on the paper machine or during the conversion process. This disclosure contemplates any one, several, or all of these application points or combinations thereof.

[0123] It has been found that adding hydrophobic softeners to the formulation prior to web formation is particularly effective in the production of soft tissue products and constitutes a typical embodiment of this disclosure. These hydrophobic softeners can be introduced directly into process water containing cellulose fibers, or typically, they can be diluted to a low consistency to improve distribution before application. The hydrophobic softeners can be introduced into mixers and pumps very early in the process, added directly to the machine tank or headbox, or added to previous stages.

[0124] The treatment of partially dehydrated paper webs with a hydrophobic softener can be accomplished in various ways. For example, the treatment steps can be spraying, application using a direct-contact applicator, foam application, or application matting. Typically, the hydrophobic softener is supplied to the air side of the paper web to avoid chemical contamination from the papermaking process. In various embodiments, it has been found in practice that hydrophobic softeners applied to the paper web from either side penetrate the entire web and treat it uniformly.

[0125] Adding a hydrophobic softener to the coating kit of a Yankee dryer can improve both softness and wrinkling quality. In this embodiment, the hydrophobic softener is expected to function both as a release agent and to transfer at least a portion of the material onto the paper sheet, thereby providing surface lubrication and softness. Here, the hydrophobic softener is typically diluted into a homogeneous, low-solids aqueous dispersion, typically with a solids content of about 0.1% to about 2%. It is usually applied to the dryer before contact with the paper sheet. The hydrophobic softener is typically applied by spray as part of the overall coating kit solution, which may contain binders, other release agents, rheology modifiers, crosslinking agents, plasticizers, dyes, passivators, adhesion promoters, etc. The hydrophobic softener may also be applied alone or in partial blends with the aforementioned coating components.

[0126] Hydrophobic softeners can also be used in post-drying or conversion operations. Typically, hydrophobic softeners are used in the form of a dilute solution, which is equilibrated to allow for uniform application without oversaturating the paper sheet. The hydrophobic softener may optionally be used as part or all of a spot wash application, which may include wash components known to those skilled in the art. The paper sheet may optionally undergo another drying process prior to future operations or use.

[0127] In various embodiments, the web is typically dehydrated via a monolithic compaction process. The web is then typically adhered to a Yankee dryer. An adhesive is then typically added directly to the metal of the Yankee dryer, advantageously sprayed directly onto the surface of the Yankee dryer rollers. Any suitable adhesive recognized in the art can be used on the Yankee dryer. Adhesives such as glyoxylated polyacrylamide and polyaminoamide have proven to provide high adhesion and are particularly suitable for manufacturing single-layer products. Typical release agents can be used according to this disclosure.

[0128] In various implementations, the web from the Yankee dryer is then creased and optionally calendered. A relatively high longitudinal stretch of the product may be necessary. The longitudinal stretch of the final product can be at least about 15%, typically at least about 18%. Generally, the longitudinal stretch of the base sheet is controlled by maintaining a fixed crease percentage, and the transverse stretch of the finished product is influenced by embossing. The relative speed between the Yankee dryer and the roll can be controlled such that at least about 18%, more typically at least 20%, and most typically at least 25% roll crease is maintained. Creasing is typically performed at a crease angle of about 65 to about 85 degrees, typically about 70 to about 80 degrees, and more typically about 75 degrees. The crease angle is defined as the angle formed between the edge surface of the creasing blade and the tangent of the Yankee dryer at the point where the creasing blade contacts the dryer, assuming the blade is rigid.

[0129] In various embodiments, the method includes the step of diluting the composition and / or the hydrophobic softener with water, for example, forming an emulsion in water prior to use in papermaking. The concentration of the hydrophobic softener in the emulsion is not particularly limited and can be, for example, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1% by weight of the total emulsion weight. In various non-limiting embodiments, all values ​​and ranges (integers and fractions) between (and including) the values ​​described above are explicitly considered herein.

[0130] In other embodiments, the weight of the hydrophobic softener is about 0.25 to about 20, about 0.5 to about 10, about 1 to about 5, about 2 to about 3.5, or about 2.5 to about 3 pounds per tonne of dry paper. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the above values ​​are explicitly considered herein.

[0131] Additional implementation schemes

[0132] In various additional embodiments, the reaction product can have the following general structure:

[0133] Fatty acid(x)-(DETA-(dimethyl adipic acid and / or dimethyl glutarate))n-DETA-fatty acid(x)

[0134] In the foregoing, n is 1 to approximately 20, approximately 2 to approximately 19, approximately 3 to approximately 18, approximately 4 to approximately 17, approximately 5 to approximately 16, approximately 6 to approximately 15, approximately 7 to approximately 14, approximately 8 to approximately 13, approximately 9 to approximately 12, approximately 10 to approximately 11, approximately 1 to approximately 10, approximately 1 to approximately 5, approximately 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, approximately 1 to approximately 2, etc. Furthermore, in the foregoing, x is approximately 0.3 to approximately 1, approximately 0.4 to approximately 0.9, approximately 0.5 to approximately 0.8, approximately 0.6 to approximately 0.7, approximately 0.5 to approximately 1, approximately 0.6 to approximately 0.9, approximately 0.7 to approximately 0.8, approximately 0.9 to approximately 1, etc. In various non-limiting embodiments, all values ​​and ranges of values ​​(integers and fractions) between (and including) the values ​​described above are explicitly considered herein.

[0135] In other embodiments, the hydrophobic softener is described as a functional component added to and retained by lignocellulosic fibers during the papermaking process. This disclosure can also be used to produce fluff pulp to provide debinding and improved water absorption of the fibers.

[0136] In other embodiments, the hydrophobic softener comprises three components: a diamine and a dicarboxylic acid, which constitute the polyamide oligomer backbone of the softener, and hydrophobic "end caps". The hydrophobic polyamide can be made by polycondensation of the three components using a method widely used to manufacture polyamides for paper wet strength (Crisp et al., U.S. Patent 9,719,212, which is expressly incorporated herein by reference in various non-limiting embodiments). However, they can be manufactured by any method known to those skilled in the art.

[0137] In various embodiments, the compositions exhibit reduced aquatic toxicity compared to conventional DES and DMS-based fabric softeners. Conventional fabric softeners containing permanent quaternized amines and imidazoline functional groups are considered to be acutely and chronically highly toxic to aquatic organisms with long-term effects. Compared to conventional DES-based fabric softeners, the various embodiments of this disclosure exhibit significantly lower toxicity to aquatic organisms on an equivalent active ingredient basis, showing at least about one-quarter to about one-tenth of the aquatic toxicity to a variety of aquatic species, including but not limited to broadhead fish and large fleas. Surprisingly, the various embodiments tested exhibited improved aquatic toxicity compared to conventional quaternized fabric softeners. This is particularly interesting because these molecules still exhibit sufficient cationic charge to allow them to be fully retained on natural anionic cellulose fibers, and the presence of cationic functional groups is generally observed to negatively impact aquatic toxicity. In various embodiments, this charge is not permanent and decreases with increasing pH. The various molecules of this disclosure may carry less charge than quaternary ammonium imidazolines at similar pH values, so the reduction in toxicity may stem from this change in charge density. Furthermore, surprisingly, the non-quaternary ammonium imidazoline materials have a higher pKa, meaning that they remain charged until the pH exceeds approximately 10 to approximately 11, and can still exhibit a reduction in aquatic toxicity to approximately 1 / 1.5 to approximately 1 / 3 of the original.

[0138] Example

[0139] Various hydrophobic softeners and compositions have been developed and evaluated to improve the softness of paper towels and / or towels. These will be described separately below.

[0140] Example 1

[0141] In the first embodiment, the jacketed glass reaction vessel is equipped with a top-mounted mixer, a water-cooled condenser, and a heated glass head. The heating jacket is set to 60°C to remove residual solvent and utilize the exothermic reaction. Dimethyl glutarate is then added to the reactor. DETA is then added after approximately 1 minute, followed by oleic acid after approximately 1 minute. The temperature of the heating jacket is then increased so that the reactor contents reach approximately 175°C, which may take approximately 1 hour. Nitrogen gas is then used to purge the reactor at a rate of approximately 0.1 L / min. While the reaction is still heating, the reactor head is heated to approximately 115°C and brought to the desired temperature, after which the reaction reaches the target temperature. Once the target temperature is reached, the components are mixed at this temperature for approximately 3 hours, and the condensate is collected. The reaction mixture is then cooled to approximately 90-100°C. Acetic acid is then added after approximately 1 minute, exothermically bringing the temperature to approximately 100-110°C. The reaction mixture is again cooled to approximately 100°C. Propylene glycol is then added and mixed for approximately five minutes or longer. Water is then added after approximately 1 minute. The reactor is then cooled and emptied. In this first experiment, the following amounts of the above components were used:

[0142] scale: 100g Components MW Eq scaling Dimethyl glutarate 160.17 1.000 14.34g DETA 103.17 1.667 15.40g Oleic acid 282.46 1.267 32.04g Removed methanol 32.04 -2.000 -5.74g Removed water 18.02 -1.267 -2.04g Acetic acid 60.052 5.000 17.03g Propylene glycol percentage 26.83％ 14.49g water percentage 26.83％ 14.49g total 100.00g

[0143] The experiment produced copolymers with the following final percentages.

[0144]

[0145] Evaluation of the composition of Example 1

[0146] After molding, the composition of Example 1 was evaluated to determine the reduction in tensile strength, deflection, and surface softness. These evaluation results were compared with those of the comparative compositions. More specifically, Example 1 was compared with the commercially available softener product ProSoft TQ250, a typical DETA and oleic acid-based tissue softener that relies on the use of diethyl sulfate to impart a permanent quaternary charge.

[0147] The results of these comparisons are shown in Figure 1A , 1B And 1C.

[0148] It is worth noting that, Figure 1A and 1B The data provided comes from pre-formed dry paper towels treated with localized spraying, and an example is given to illustrate the conversion process. Figure 1C The data provided is derived from the production of handmade paper, and an example illustrates wet-end addition. This example demonstrates that even if the product does not have "permanent" cationic properties, it remains on the fibers.

[0149] Example 2

[0150] In the second experiment, the same procedure as described above was performed using the following components. In this experiment, adipic acid was added in powder form, and the acid-base interaction between DETA and adipic acid produced a greater exothermic reaction.

[0151] scale: 100g Components MW Eq scaling adipic acid 146.14 1 13.26g DETA 103.17 1.667 15.61g Oleic acid 282.46 1.267 32.48g Removed water 18.02 -3.3333 -5.45g Acetic acid 60.052 4.00 14.10g Propylene glycol percentage 26.83％ 15.00g water percentage 26.83％ 15.00g total 100.00g

[0152] The experiment produced copolymers with the following final percentages.

[0153]

[0154] These embodiments demonstrate superior and unexpected benefits related to the manufacturing process and transportation of these products, with efficiencies significantly exceeding expectations. Furthermore, Example 1 also demonstrates superior and unexpected retention of the hydrophobic softener in wet-end applications, due to its blending with fibers and water prior to the production of handmade sheets on a dynamic sheet forming machine.

[0155] Additional embodiments were also prepared as described below.

[0156] Preparation of DETA:Adipic acid:Stearic acid hydrophobic polyamide of Example A-2:1:1.9

[0157] To a 1-liter, four-necked flask equipped with a feeding funnel, a Dean-Stark water separator / condenser, a top stirrer, and a thermocouple thermometer, add 18.1 g of adipic acid (0.124 mol) and 66.4 g of stearic acid (0.233 mol). Using a large pipette, add 25.5 g of DETA (0.247 mol) to the stirred mixture. Then heat the resulting slurry to 175°C using a heating mantle. At this point, the reaction mixture is clear and amber in color. Continue heating at 175°C for three hours. After heating for one hour, start a slow nitrogen flow to purge water from the reaction flask. 8.1 g of water was collected in the Dean-Stark water separator.

[0158] The thermocouple setpoint was then lowered to 120°C, and the reaction mixture was allowed to cool. When the reaction temperature dropped below 140°C, acidified dilution water (consisting of 12.4 g concentrated H₂SO₄ (0.95 equivalents) and 738 g water) was added. The dilution water was added slowly to avoid excessive boiling and bumping of the reaction mixture. Once the mixture cooled below 100°C and the boiling subsided, the addition of dilution water was maintained at a rate above 85°C (this process takes approximately one hour). After the dilution water addition was complete, the emulsion was stirred at 90°C for another hour.

[0159] Emulsification of DETA:Adipic Acid:Stearic Acid Hydrophobic Polyamide in Example B-2:1:1.9

[0160] A sample of 50g of the 2:1:1.9 DETA:adipic acid:stearic acid hydrophobic polyamide softener described in Example A was heated in an oven at 80°C for one hour. An aliquot of 98g of distilled water was placed in a blending vessel and heated to 80°C in a water bath. The hot vessel was then removed from the water bath, and 2g of the 2:1:1.9 DETA:adipic acid:stearic acid polyamide was added. The hot mixture was immediately blended at "high" for 60 seconds. The blended emulsion was allowed to cool to room temperature. The particle size (241nm) and zeta potential (+55mV) of the emulsion (record number X-00174-87) were determined using a Wyatt Mobius apparatus at the University of Delaware ISE Laboratory (Newark, Delaware).

[0161] Example C - Adding a hydrophobic polyamide softener emulsion to the surface of creased paper towels

[0162] The surface of commercially available toilet paper rolls was treated with a 2:1:1.9 DETA:adipic acid:oleic acid hydrophobic polyamide emulsion prepared according to the methods described in Examples A and B. The emulsion was applied using a Little Giant Speedy Label Maker offset printing press (Sohn Manufacturing Inc., Elkhart Lake, Wisconsin). Evaluation was performed using single-layer crepe paper (Kimberly-Clark-) obtained from Office Depot. (Continuous rolls of paper).

[0163] The amount of hydrophobic polyamide softener added to the paper towels is controlled by adjusting the solids percentage (% solids) of the emulsion. The solids percentage of the emulsion is selected based on the wet “pick-up” percentage of the paper towels on the offset printing press and the desired softener addition level. All emulsions are pH-adjusted to 5.5 before testing. Wet pick-up is calculated using the difference between the dry weight of the paper towels before printing and the wet weight of the paper towels after printing. For example, a 2.5% solids emulsion would require a softener addition level of 0.25% (pounds per ton, ppt) at a 10% wet pick-up. The softener-treated paper towels are dried at 90°C for 30 minutes and then equilibrated overnight at 50% relative humidity and 72°C before testing.

[0164] Example D - Softness test of paper towels treated with hydrophobic polyamide-DETA: adipic acid: oleic acid

[0165] Three hydrophobic polyamides were prepared using the method described in Example A and emulsified using the method described in Example B. Figure 2 The polyamide softeners tested, as listed in the table, were prepared in DETA: adipic acid: oleic acid ratios of 2:1:1.9, 5:3:3.8, and 3:2:1.9.

[0166] The softening properties of the hydrophobic polyamide emulsion were evaluated using the surface addition method described in Example C. Three independent studies were conducted to test the softener at addition levels of 2 lb / ton dry weight of treated tissue (ppt), 3 ppt, and 4 ppt. ProSoft TQ218 (a commercially available tissue softener from Solenis Inc., Wilmington, Delaware) was evaluated as a control within the same addition level range. Hercobond1194 (a commercially available temporary wet strength resin from Solenis Inc., Wilmington, Delaware) was added to the tissue along with each softener in all tests at a fixed addition level of 4 ppt. Hercobond1194-treated tissue samples without added softener were tested as controls. The softness of the treated tissues was quantified using an Emtec Tissue Softness Analyzer (TSA, Leipzig, Germany). The TSA-S7 (lower values ​​indicate softer paper towels) and TSA-D [mm / N] (higher values ​​indicate softer paper towels) test results are used to quantify the softness of treated paper towels. Figure 2 The table lists a series of softeners, the amount added, and the corresponding softening results.

[0167] Consistent with commercial experience, adding ProSoft TQ218 to tissues treated with temporary wet strength agents improved the softness of TSA-S7 and TSA-D [mm / N]. All three hydrophobic polyamide softeners improved softness across the entire range of tested addition levels, achieving softness comparable to that obtained using ProSoft TQ218.

[0168] Example E - Hydrophobic materials prepared with a wide range of DETA: adipic acid: oleic acid ratios (oleic acid ratio fixed at 1.9) Polyamide undergoes softness testing

[0169] Six hydrophobic polyamides were prepared using the method described in Example A and emulsified using the method described in Example B. Figure 3 The polyamide softeners tested, as listed in the table, were prepared in DETA: adipic acid: oleic acid ratios of 3:2:1.9, 5:4:1.9, 7:6:1.9, 9:8:1.9, and 11:10:1.9.

[0170] Particle size and zeta potential tests showed that the hydrophobic polyamide emulsions produced had particle sizes between 60 and 100 nanometers (nm) and zeta potentials between +30 and +35 millivolts (mV) (tested using the Wyatt Mobius apparatus at the ISE laboratory at the University of Delaware (Newark, Delaware) in deionized water). Some hydrophobic polyamide emulsions remained well dispersed after one month of aging at room temperature. One particular hydrophobic polyamide exhibited optimal stratification stability. Another hydrophobic polyamide was water-soluble; particle size and zeta potential were not tested. The solution remained stable after one month of aging.

[0171] The softening properties of the hydrophobic polyamide emulsion were then evaluated using the surface addition method described in Example C. ProSoft TQ218 (a commercially available tissue softener from Solenis Inc., Wilmington, Delaware) was evaluated as a control. The softener addition level was fixed at 2 ppt. Hercobond 1194 (fixed at 4 ppt, a commercially available temporary wet strength resin softener from Solenis Inc., Wilmington, Delaware) was added to the tissue along with each softener in all tests. Hercobond 1194-treated tissue samples without added softener were tested as controls.

[0172] The softness of treated paper towels was quantitatively determined using an Emtec Tissue Softness Analyzer (TSA, Leipzig, Germany). The TSA-S7 (lower values ​​indicate softer paper towels) and TSA-D [mm / N] (higher values ​​indicate softer paper towels) results were used to quantify the softness of the treated paper towels. Figure 3 The table lists the Emtec TSA test results for hydrophobic polyamide-treated paper towels.

[0173] Consistent with commercial experience, adding ProSoft TQ218 to tissues treated with Hercobond 1194 temporary wet strength agent improved the softness of TSA-S7 and TSA-D [mm / N]. The improvement in softness obtained with hydrophobically modified polyamides increased as the "n" value of the polyamide decreased. Hydrophobically modified polyamides prepared at DETA:adipic acid:oleic acid ratios of 3:2:1.9 and 5:4:1.9 resulted in TSA-S7 and TSA-D [mm / N] softness improvements close to those obtained using the ProSoft TQ218 control. Hydrophobically modified polyamides prepared at a DETA:adipic acid:oleic acid ratio of 11:10:1.9 showed little or no improvement in TSA softness. Hydrophobic polyamides prepared at moderate ratios (DETA: adipic acid: oleic acid 7:6:1.9 and 9:8:1.9, n = 6 and 8) improved the [mm / N] softness of TSA-S7 and TSA-D. However, the improvement in softness was less than that obtained using the ProSoft TQ218 control.

[0174] Example F - Hydrophobic materials prepared with a wide range of DETA: adipic acid: oleic acid ratios (oleic acid ratio fixed at 1.5) Polyamide undergoes softness testing

[0175] Four hydrophobic polyamides were prepared using the method described in Example A and emulsified using the method described in Example B. Figure 4 As listed in the table, the tested polyamide softeners were prepared with DETA: adipic acid: oleic acid ratios of 2:1:1.5, 3:2:1.5, 5:4:1.5, and 9:8:1.5. All four hydrophobic polyamide emulsions prepared at n = 1, 2, 4, and 8 maintained good dispersion after one month of aging at room temperature. However, the polyamide emulsion prepared with 1.5 parts oleic acid generally separated more rapidly than the corresponding emulsion prepared with 1.9 parts oleic acid (compared to Example E).

[0176] The softening properties of the hydrophobic polyamide emulsion were then evaluated using the surface addition method described in Example C. ProSoft TQ218 (a commercially available tissue softener from Solenis Inc., Wilmington, Delaware) was evaluated as a control. The softener addition level was fixed at 2 ppt. Hercobond 1194 (fixed at 4 ppt, a commercially available temporary wet strength resin softener from Solenis Inc., Wilmington, Delaware) was added to the tissue along with each softener in all tests. Hercobond 1194-treated tissue samples without added softener were tested as controls.

[0177] The softness of treated paper towels was quantitatively determined using an Emtec Tissue Softness Analyzer (TSA, Leipzig, Germany). The TSA-S7 (lower values ​​indicate softer paper towels) and TSA-D [mm / N] (higher values ​​indicate softer paper towels) results were used to quantify the softness of the treated paper towels. Figure 4 The table lists the Emtec TSA test results for paper towels treated with hydrophobic polyamide.

[0178] Consistent with commercial experience, adding ProSoft TQ218 to tissues treated with Hercobond 1194 temporary wet strength agent improved the softness of TSA-S7 and TSA-D [mm / N]. The improvement in softness obtained with hydrophobically modified polyamides increased as the "n" value of the polyamide decreased. Hydrophobically modified polyamides prepared at DETA:adipic acid:oleic acid ratios of 2:1:1.5 and 3:2:1.5 resulted in TSA-S7 and TSA-D [mm / N] softness improvements close to those obtained using the ProSoft TQ218 control. Hydrophobically modified polyamides prepared at DETA:adipic acid:oleic acid ratios of 5:4:1.5 and 9:8:1.5 showed little or no improvement in TSA softness.

[0179] Example G - Preparation of succinic acid with a wide range of DETA:succinic acid:oleic acid ratios (oleic acid ratio fixed at 1.5). The hydrophobic polyamide was tested for flexibility.

[0180] Four hydrophobic polyamides were prepared using the method described in Example A and emulsified using the method described in Example B. Figure 5 The polyamide softeners tested, as listed in the table, were prepared in DETA:succinic acid:oleic acid ratios of 2:1:1.5, 4:3:1.5, 6:5:1.5, and 11:10:1.5.

[0181] The softening properties of the hydrophobic polyamide emulsion were then evaluated using the surface addition method described in Example C. ProSoft TQ218 (a commercially available tissue softener from Solenis Inc., Wilmington, Delaware) was used as a control. The softener addition level was fixed at 5 ppt. Water-treated tissue samples were tested as “blank samples.” The softness of the treated tissues was quantified using a Thwing Albert Handle-o-Meter Softness Tester (HoM, West Berlin, New Jersey) (a lower HoM value indicates a softer tissue).

[0182] Figure 5The table lists the HoM softness test results for the treated tissues. Consistent with commercial experience, the addition of ProSoft TQ218 improved the softness of the tissues (compared to the water-treated blank). The improvement in softness obtained with hydrophobically modified polyamides increased again as the "n" value of the polyamide decreased. Hydrophobically modified polyamides prepared at a DETA:succinic acid:oleic acid ratio of 2:1:1.5 resulted in a HoM softness improvement close to that obtained using the ProSoft TQ218 control. Hydrophobically modified polyamides prepared at a DETA:succinic acid:oleic acid ratio of 4:3:1.5 resulted in a smaller but still significant improvement in HoM softness. Hydrophobically modified polyamides prepared at DETA:succinic acid:oleic acid ratios of 6:5:1.5 and 11:10:1.5 resulted in the smallest improvements in HoM softness.

[0183] Example H - prepared with a wide range of DETA: adipic acid: stearic acid ratios (stearic acid ratio fixed at 1.9). Softness test of hydrophobic polyamide

[0184] Five hydrophobic polyamides were prepared using the method described in Example A and emulsified using the method described in Example B. Figure 6 As listed in the table, the tested polyamide softeners were prepared with DETA: adipic acid: stearic acid ratios of 2:1:1.9, 3:2:1.9, 5:4:1.9, 7:6:1.9, and 9:8:1.9. All five hydrophobic polyamide emulsions prepared at n=1, 2, 4, 6, and 8 maintained good dispersion after aging at room temperature for one month.

[0185] However, polyamide emulsions made with stearic acid separate into layers more quickly than their counterparts made with oleic acid.

[0186] The softening properties of the hydrophobic polyamide emulsion were then evaluated using the surface addition method described in Example C. ProSoft TQ218 (a commercially available tissue softener from Solenis Inc., Wilmington, Delaware) was evaluated as a control. The softener addition level was fixed at 2 ppt. Hercobond 1194 (fixed at 4 ppt, a commercially available temporary wet strength resin softener from Solenis Inc., Wilmington, Delaware) was added to the tissue along with each softener in all tests. Hercobond 1194-treated tissue samples without added softener were tested as controls. The pH was fixed at 5.5 in all tests.

[0187] The softness of treated paper towels was quantitatively determined using an Emtec Tissue Softness Analyzer (TSA, Leipzig, Germany). The TSA-S7 (lower values ​​indicate softer paper towels) and TSA-D [mm / N] (higher values ​​indicate softer paper towels) results were used to quantify the softness of the treated paper towels. Figure 6 The table lists the Emtec TSA test results for paper towels treated with hydrophobic polyamide.

[0188] Consistent with commercial experience, adding ProSoft TQ218 to tissues treated with Hercobond 1194 temporary wet strength agent improved the softness of TSA-S7 and TSA-D [mm / N]. The improvement in softness obtained with hydrophobically modified polyamides increased as the "n" value of the polyamide decreased. Hydrophobically modified polyamides prepared with DETA:adipic acid:stearic acid ratios of 2:1:1.9, 3:2:1.9, and 5:4:1.9 resulted in TSA-S7 and TSA-D [mm / N] softness improvements close to those obtained using the ProSoft TQ218 control. Hydrophobically modified polyamides prepared with DETA:adipic acid:stearic acid ratios of 7:6:1.9 and 9:8:1.9 showed little or no improvement in TSA softness.

[0189] Example I - Softness test of hydrophobic polyamide containing C36 dimer acid - using hydrophobic polyamide as a dispersion emulsifier / emulsifier

[0190] Two hydrophobic polyamides were prepared using the method described in Example A: a 1.8:11:4:6 stearic acid:DETA:C36 dimer:adipic acid oligomer; and a 1.8:11:10 stearic acid:DETA:adipic acid oligomer. The hydrophobic polyamide containing C36 dimer (Pripol 1006, Croda Inc.) was too hydrophobic to self-emulsify in water. The 1.8:11:10 stearic acid:DETA:adipic acid oligomer was readily dispersed in water.

[0191] A stable 5% solids emulsion of these two polyamides was prepared by mixing 80 g of a hydrophobic polyamide containing C36 dimer acid (5% solids) with 20 g of a 1.8:11:10 stearic acid:DETA:adipic acid mixture (5% solids) in a steam-jacketed starch pan set at 90°C for 30 minutes. Subsequent studies showed that this 1.8:11:10 stearic acid:DETA:adipic acid oligomer can also be used to disperse microcrystalline waxes in water (10% hydrophobic polyamide, 90% G-Wax, melting point 60°C, Solenis Inc.).

[0192] The softness properties of the blended polyamide emulsion were evaluated using the surface addition method described in Example C (addition level fixed at 4 ppt) (compared to the softness of the untreated blank sample). ProSoft TQ218 was evaluated as a control (addition level fixed at 4 ppt).

[0193] HoM, TSA-S7, and TSA-D [mm / N] were used as measures of softener performance. The results of the softening tests are listed in Table 6. The HoM and TSA-D [mm / N] softening properties of the blended polyamide emulsion were close to those of the ProSoft TQ218 control. TSA-S7 also showed a slight improvement compared to the untreated blank sample.

[0194] Data indicate that both adipic acid and dimethyl glutarate are viable options. The products of these reactions are termed "hydrophobically modified polyamides." The number of repeating units is customized to provide maximum performance while maintaining excellent self-emulsifying properties. We found that a narrow operating window can provide performance comparable to existing technologies, and is also a stable and commercially viable product.

[0195] To meet the requirements of Proposition 65 and improve aquatic toxicology, the DES / DMS alkylating agent was removed from the process. This resulted in poor emulsification properties and reduced softening effect in the product. To address these issues, a finely tunable hydrophilic polyamide component was integrated into the middle of the DETA / oleic acid softening molecules. For this purpose, a diacid was added during the condensation step of the synthesis of these molecules.

[0196] More specifically, various embodiments of this disclosure exhibit toxicity of at least about 1 / 4 to about 1 / 10 of the comparative embodiments. As mentioned above, surprisingly, despite the high charge density of the softener, these inventive compositions exhibit low toxicity, see, for example, the data for measuring Mutek charge density at pH 8 listed below:

[0197]

[0198] The reported values ​​have been corrected for comparison with equivalent active ingredients.

[0199] LC50 represents the concentration of the test substance that is estimated to cause 50% of the test organisms to die.

[0200] For large fleas

[0201] Test method: Organization for Economic Cooperation and Development (OECD). 2004. Guideline #202, "Daphnia sp., Acute Immobilization Test," OECD Guidelines for Testing of Chemicals. 48-hour LC50 by Spearman- The calculation method for (CETIS) is determined.

[0202] The test follows the general conditions of the referenced test method. Prepare a 20 mg / L (w / v) test solution by weighing an appropriate amount of the test sample and gradually mixing it thoroughly with the control / diluent until homogeneous. Mix an appropriate amount of the 20 mg / L test solution with the control / diluent to achieve the remaining desired test concentration. Thoroughly mix the test solution before starting the test. Summarize the data from repeated tests to calculate and report the results.

[0203] For the bighead carp

[0204] Test method: Organization for Economic Cooperation and Development (OECD). June 2019. Guideline #203, "Fish, Acute Toxicity Test". OECD Guidelines for Testing of Chemicals. The 96-hour LC50 was determined by the binomial (CETIS) calculation method.

[0205] The test follows the general conditions of the referenced test method. Prepare a 200 mg / L (w / v) test solution by weighing an appropriate amount of the test sample and mixing it thoroughly with the control / diluent until homogeneous. Mix an appropriate amount of the 200 mg / L test solution with the control / diluent to achieve the remaining desired test concentration. Mix the test solution thoroughly before starting the test.

[0206] The above data indicate that these compositions exhibit the same or better softening properties compared to conventional DES and DMS-based softeners. Furthermore, the data show that the softeners can be applied using various conventional methods, where they repeatedly demonstrate the same or better performance. In addition, the hydrophobic softeners exhibit significantly improved aquatic toxicity. This is particularly surprising because these molecules contain sufficient cationic charge to allow them to be well retained in wet-end applications (Examples / ). Figure 1C Furthermore, it is generally believed that the presence of cationic functional groups may have a negative impact on aquatic toxicity.

[0207] While at least one exemplary embodiment has been presented in the foregoing detailed descriptions, it should be understood that numerous variations exist. It should also be understood that the one or more exemplary embodiments described are merely exemplary and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing detailed descriptions will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiments. It should be understood that various changes can be made to the function and arrangement of the elements described in the exemplary embodiments without departing from the scope defined in the appended claims.

Claims

1. A composition for improving the softness of paper towels and / or towel products, said composition comprising: A. Lignocellulose fiber; B. Water; and C. Hydrophobic softeners, which contain the reaction products of the following substances: (1) At least one diamine and / or polyamine; (2) At least one chain extender having at least two carboxyl groups; and (3) At least one hydrophobic end-capping agent selected from fatty acids, fatty acid esters, fatty acyl chlorides, fatty alkyl halides, epoxides of hydrocarbons, carboxylic anhydrides of hydrocarbons, and combinations thereof, any one or more of which have 4 to about 40 carbon atoms, and Based on the total number of moles of active amine sites in the reaction product, the reaction product includes at least about 25 mol% hydrophobic substitution of the hydrophobic end-capping agent.

2. The composition according to claim 1, wherein the at least one diamine and / or polyamine is selected from polyalkyleneamines, polyalkylimides, and combinations thereof.

3. The composition according to claim 1, wherein the at least one diamine and / or polyamine is selected from diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), dipropylenetriamine (DPTA), tripropylenetetramine (TPTA), tetrapropylenepentamine (TPPA), pentapropylenehexamine (PPHA), dihexamethylenetriamine (DHMTA), methyldiaminopropylamine (MBAPA), hexamethylenediamine, ethylenediamine, and combinations thereof.

4. The composition according to claim 1, wherein the at least one diamine and / or polyamine is selected from polyethylene polyamines, polyalkylene polyamines, and combinations thereof.

5. The composition according to claim 1, wherein the at least one chain extender is selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, dodecanoic acid, C36 dimer acid, dimethyl glutarate, diesters of these acids, and combinations thereof.

6. The composition according to claim 1, wherein the at least one hydrophobic end-capping agent is a fatty acid having about 12 to about 20 carbon atoms.

7. The composition according to claim 6, wherein the fatty acid is selected from caprylic acid, nonanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, linoleic acid, oleic acid, and combinations thereof.

8. The composition according to any one of claims 1 to 7, wherein (1), (2) and (3) react in a molar ratio of about (1 to 3): about 1: about (0.9 to 4).

9. The composition according to any one of claims 1 to 7, wherein the hydrophobic softener further comprises the imidazoline cyclized adducts of (1), (2) and (3).

10. The composition according to any one of claims 1 to 7, wherein it is free of nonionic surfactants.

11. A method for improving the softness of paper towels and / or towel products, the method comprising the following steps: A. Provides lignocellulose fiber; B. Provide water; C. Provide hydrophobic softener; D. Combining lignocellulose fibers, water, and a hydrophobic softener; and F. Using a combination of lignocellulose fibers, water, and hydrophobic softeners to produce paper towels and / or towel products; The hydrophobic softener comprises the reaction products of the following substances: (1) At least one diamine and / or polyamine; (2) At least one chain extender having at least two carboxyl groups; and (3) At least one hydrophobic end-capping agent selected from fatty acids, fatty acid esters, fatty acyl chlorides, fatty alkyl halides, epoxides of hydrocarbons, carboxylic anhydrides of hydrocarbons, and combinations thereof, any one or more of which have 4 to about 40 carbon atoms, and Based on the total number of moles of active amine sites in the reaction product, the reaction product includes at least about 25 mol% hydrophobic substitution of the hydrophobic end-capping agent.

12. The method according to claim 11, wherein the lignocellulose fiber is in the form of a wet-laid fiber.

13. The method of claim 12, wherein the lignocellulose fibers are arranged on a dryer.

14. The method of claim 11, wherein the hydrophobic softener further comprises an imidazoline cyclized adduct.

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